WO2007040339A1

WO2007040339A1 - Manufacturing process of pattern ornament through molding ultraviolet-curing resin

Info

Publication number: WO2007040339A1
Application number: PCT/KR2006/003985
Authority: WO
Inventors: Ki-Hong Park
Original assignee: Minuta Technology
Priority date: 2005-10-06
Filing date: 2006-10-02
Publication date: 2007-04-12
Also published as: CN101282837B; CN101282837A; KR100780413B1; KR20070038892A

Abstract

The present invention relates to a process for producing a patterned decorative material using moldings of ultraviolet (UV)-curable resins, which process allows production of various decorative materials having desired pattern forms for the decoration of windows of various electric and electronic instruments such as mobile phones and MP3 players and other accessories, by applying a UV-curable resin on a substrate formed of a plastic film, a polycarbonate sheet, an acrylic sheet, a metal sheet, a glass sheet or thelike; forming a UV-curable organic mold or an elastic mold of polydimethylsiloxane, having a pattern form formed thereon; pressingthe organic mold or elastic mold against the UV-curable resin on the substrate and irradiating UV rays to form a pattern form. The process according to the invention is advantageous in that the risk of scar and defect generation on the patterning mold is significantly low, the yield and economic efficiency are high, and large-area patterned decorative materials of high quality can be easily produced with excellent workability and productivity, compared with conventional methods of thermal pressing and adhesion using pattern form master rolls. The process according to the invention also allows production of decorative materials manifesting pattern images of higher brightness compared with conventional decorative materials.

Description

MANUFACTURING PROCESS OF PATTERN ORNAMENT THROUGH MOLDING ULTRAVIOLET-CURING RESIN

Technical Field

[1] The present invention relates to a process for producing a pattern ornament

(patterned decorative material) using moldings of ultraviolet-curable resin, and a decorative material produced by the process. Background Art

[2] Patterned decorative materials are widely used for decoration of various products, and particularly in recent years, the materials are extensively used in the decoration of display windows or exterior casings of mobile phones. Such decorative materials use pattern forms formed of synthetic resin films or metal foils, having a thickness of 50 to 300 D, and patterns are formed on these materials to manifest unique textures and pattern images. Specifically, when structures such as embossment, prism, hairspin, hairline, lens, semispherical lens, cylinder, triangular pyramid, tetragonal pyramid, hexagonal pyramid, line and space, hole and the like are formed in a repeating manner on thin films of the materials described above, pattern images inherent to the respective structures are manifested. Most of these pattern forms may be classified as high b Tightness reflective pattern forms, and in particular, prismatic pattern forms exhibit the features of an ultrahigh brightness reflective pattern form.

[3] Meanwhile, when the dimension of the structures is in the range of a few ten to a few hundred micrometers, not only the pattern images but also the unique textures inherent to the respective structures can be perceived visually. Furthermore, in the case where thestructures are regular microstructures having a dimension of a few micrometers or less, the microstructures project and reproduce colorful three-dimensional holographic images which are induced by light interference, refraction and/or reflection on the patterned surfaces, and the three-dimensional images thus reproduced are usually referred to as holographic images.

[4] A pattern form film used for patterned decorative materials is conventionally produced by continuously imprinting a pattern form on the surface of a synthetic resin film or a metal foil using a pattern form master roll having a pattern form formed thereon, under constant pressure conditions. The pattern form film thus produced is adhered and impressed on various base materials to produce patterned decorative materials.

[5] However, in such a conventional process of imprinting and attaching as described above, the heat generated inevitably during the process causes partial degradation in the pattern formfilm, and thus, black spot-shaped defects such as pinholes are likely to be generated at the contacting interface between the pattern form film and the base material. Accordingly, it is not only difficult to obtain high quality and high brightness pattern images, but it is also inapplicable to use the above-described process of imprinting and attaching, in the case of forming large area pattern forms, which are different from small area pattern forms such as characters, because of the quality degradation resulting from an increase in the density of such defectsassociated with the area increase. Furthermore, the difficulties in the attachment of pattern form films lead to another disadvantage that the type of base material that can be used is fairly limited.

[6] Meanwhile, among conventional techniques for producing a pattern formmaster roll used in the production of pattern form films, the following processes have been mainly used: a process of processing an embossed pattern formdirectly on the exterior surface of a metal roll using a laser ray and a process of forming a pattern form on a glass sheet or the like using a laser ray, fabricating a metal foil-type molding sheet, known as a shim, by electroplating the glass sheet with a metal such as nickel or the like, and adhering the shim, which has been peeled off from the pattern form on the glass sheet, on the exterior surface of a metal roll by completely winding the shim around the metal roll. However, the former process of forming an embossed pattern form on the exterior surface of a metal roll using a laser ray necessitates very high precision in the operation, thus requiring high production costs despite low operability and pro- ductivity,and thus, the process is scarcely used in recent years. The latter process of producing a master roll using a metal foil-type molding sheet exhibits higher productivity than the former process, and has been widely used heretofore. However,this process also has disadvantages such as high production costs and a high possibility of defect generation in the metal foil during the operation. Furthermore, if defects are generated in the metal foil molding sheet made of nickel or the like during the operation, perfect pattern images cannot be formed, and refabrication of the metal foil molding sheet leads to losses in the facility investment. Also, in the case of planning an extension of the width of the pattern form master roll for enhanced productivity of pattern formfilms, the size of the metal foil molding sheet produced by electroplating using nickel or the like, should also be increased along with the increasing width of the pattern form master roll however, it is difficult at thecurrent status of technology to increase the size of a metal foil without compromising economic efficiency. Disclosure of Invention Technical Problem

[7] In an attempt to address such problems of conventional technologies as described above, the inventors of thepresent invention devotedly conducted research and completed the present invention. Thus, it is an object of the invention to provide a process for producing a patterned decorative material, using a patterning mold which is formed of a synthetic resin and has been replicated from a master mold, instead of directly using the pattern form master mold as in conventional technologies. The invented process advantageously allows convenient transfer of pattern forms to various base materials at low costs, enables formation of pattern forms of high quality and high brightness without generating any scars or defects on the base materials, and facilitates size increment of patterned decorative materials.

Technical Solution [8] Thus, according to an aspect of the present invention, there is provided a process for producing a patterned decorative material, the process comprising the steps of: [9] (A-I) applying an ultraviolet (UV)-curable molding resin for patterning mold on a master mold having a pattern form formed thereon;

[10] (A-2) attaching a support onto the UV-curable molding resin for patterning mold;

[11] (A-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for patterning mold and to form a patterning mold; [12] (A-4) separating the patterning mold from the master mold

[13] (A-5) applying a UV-curable resin for pattern form on a substrate;

[14] (A-6) pressing the patterning mold againstthe UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form

[15] (A-7) separating the pattern form from the patterning mold;

[16] (A-8) forming a refractive/reflective layer on the pattern form and

[17] (A-9) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat. [18] According to an embodiment of the present invention, the processfurther comprises the step of: [19] (A- 10) color coating by printing on a part of the patterned surface of the patterning mold or on a part of the rear surface of the support,

[20] after the step (A-4) and before the step (A-6); and further comprises the step of:

[21] (A-I l) removing any uncured portion of the UV-curable resin for pattern form by dissolving the uncured portion in a solvent, [22] after the step (A-7) and before the step (A-8).

[23] According to another embodiment of the present invention, the process further comprises the step of: [24] (A-IO') shielding a part of the patterned surface of the patterning mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the patterning mold or the support,

[25] after the step (A-4) and before the step (A-6); and further comprises the step of:

[26] (A-I l) removing any uncured portion of the UV-curable resin for pattern form by dissolving the uncured portion in a solvent, [27] after the step (A-7) and before the step (A-8).

[28] According to another aspect of the present invention, there is provided a process for producing a patterned decorative material, the process comprising the steps of: [29] (B-I) applying a UV-curable molding resin for replica mastermold on a master mold having a pattern form formed thereon;

[30] (B-2) attaching a support to the UV-curable molding resin for replica master mold;

[31] (B-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for replica master mold and to form a replica master mold;

[32] (B-4) separating the replica master mold from the master mold;

[33] (B-5) applying a UV-curable molding resin for base on a separate support;

[34] (B-6) irradiating UV rays on the UV-curable molding resin for base to pseudo-cure the UV-curable molding resin for base; [35] (B-7) applying a UV-curable molding resin for patterning mold on the pseudo-cured base; [36] (B-8) pressing the replica master mold against the UV-curable molding resin for patterning mold and irradiating UV rays, to cure the UV-curable molding resin for patterning mold and to form a patterning mold;

[37] (B-9) separating the patterning mold from the replica master mold;

[38] (B- 10) applying a UV-curable resin for pattern form on a substrate;

[39] (B-I l) pressing the patterning mold against the UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form

[40] (B- 12) separating the pattern form from the patterning mold;

[41] (B- 13) forming a refractive/reflective layer on the pattern form and

[42] (B- 14) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat. [43] According to an embodiment of the present invention, the above-described process further comprises the step of: [44] (B- 15) color coating by printing on a part of the patterned surface of the replica master mold or on a part of the rear surface of the support,

[45] after the step (B-4) and before the step (B-8); and further comprises the step of:

[46] (B- 16) removing any uncured portion of the UV-curable molding resin for patterning mold by dissolving the uncured portion in a solvent, [47] after the step (B-9) and before the step (B-I l).

[48] According to another embodiment of the present invention, the process further comprises the step of: [49] (B-15¹) shielding a part of the patterned surface of the replica master mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the replica master mold or the support,

[50] after the step (B-4) and before the step (B-8); and further comprises the step of:

[51] (B- 16) removing any uncured portion of the UV-curable molding resin for patterning mold by dissolving the uncured portion in a solvent, [52] after the step (B-9) and before the step (B-I l).

[53] According to another aspect of the present invention, there is provided a process for producing a patterned decorative material, the process comprising the steps of: [54] (C-I) applying a UV-curable molding resin for replica master mold on a master mold having a pattern form formed thereon;

[55] (C-2) attaching a support to the UV-curable molding resin for replica master mold;

[56] (C-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for replica master mold and to form a replica master mold;

[57] (C-4) separating the replica master mold from the master mold;

[58] (C-5) applying a UV-curable molding resin for pre-mold on a substrate

[59] (C-6) pressing the replica master mold against the UV-curable molding resin for pre-mold and irradiating UV rays, to cure the UV-curable molding resin for pre-mold and to form a pre-mold

[60] (C-7) separating the pre-mold to the replica master mold;

[61] (C-8) placing the substrate having the pre-mold formed thereon into a mold frame, and adding polydimethylsiloxane and a curing agent to the mold frame [62] (C-9) thermally curing the polydimethylsiloxane and curing agent to form an elastic mold;

[63] (C-IO) separating the elastic mold from the pre-mold;

[64] (C-I l) applying a UV-curable resin for pattern form on a separate substrate;

[65] (C- 12) pressing the elastic mold againstthe UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form

[66] (C- 13) separating the pattern form from the elastic mold;

[67] (C- 14) forming a refractive/reflective layer on the pattern form and

[68] (C- 15) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat. [69] According to an embodiment of the present invention, the above-described process further comprises the steps of:

[70] (C- 19) applying a UV-curable molding resin for patterning mold on a support;

[71] (C-20) pressing the elastic mold against the UV-curable molding resin for patterning mold and irradiating UV rays, to cure the UV-curable molding resin for patterning mold and to form a patterning mold; and [72] (C-21) separating the pattering mold from the elastic mold,

[73] after the step (C-10) and before the step (C-I l), wherein the steps (C- 12) and

(C- 13) are replaced by the steps of: [74] (C- 12') pressing the patterning mold againstthe UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form and

[75] (C-13¹) separating the pattern form from the patterning mold.

[76] According to another embodiment of the present invention, the process further comprises the step of: [77] (C- 16) color coating by printing on a part of the patterned surface of thereplica master mold or on a part of the rear surface of the support,

[78] after the step (C-4) and before the step (C-6); and further comprises the step of:

[79] (C- 17) removing any uncured portion of the UV-curable molding resin for pre-mold by dissolving the uncured portion in a solvent, [80] after the step (C-7) and before the step (C-8).

[81] According to another embodiment of the present invention, the process further comprises the step of: [82] (C- 16') shielding a part of the patterned surface of thereplica master mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the replica master mold or the support,

[83] after the step (C-4) and before the step (C-6); and further comprises the step of

[84] (C- 17) removing any uncured portion of the UV-curable molding resin for pre-mold by dissolving the uncured portion in a solvent, [85] after the step (C-7) and before the step (C-8).

[86] According to another embodiment of the present invention, the process further comprises the step of:

[87] (C- 18) applying a UV-curable molding resin for primer on a substrate,

[88] after the step (C-4) and before the step (C-5), whereinthe step (C-5) is replaced by the step of: [89] (C-5¹) applying a UV-curable molding resin for pre-mold on the UV-curable molding resin for primer. [90] The substrate onto which the UV-curable molding resin for pre-mold and/or the

UV-curable molding resin for primer is applied may be a glass substrate. [91] The overcoat may have a refractive index which differs in value by 0.3 or less from that of the UV-curable resin for pattern form. [92] The color of the color coating printed in the step (A-10), (B-15) or (C-16) may be black. [93] The solvent used in the step (A-I l), (B- 16) or (C- 17) may be a ketone or an alcohol, while the dissolution time may be 15 seconds to 60 seconds. [94] The opaque metal used in the step (A-IO'), (B-15¹) or (C-16¹) may be selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), silver (Ag), gold

(Au) and copper (Cu). [95] The thickness of the opaque metal layer formed in the step (A-IO'), (B- 15') or

(C- 16') may be 0.1 to 2 D. [96] According to another embodiment of the invention, the process further comprises the step of: [97] (A- 12) shielding the portion of no pattern image manifestation in the pattern form with a shadow mask, [98] after the step (A-7) and before the step (A-8), after the step (B- 12) and before the step (B-13), or after the (C-13) and before the step (C-14); and further comprises the step of: [99] (A- 13) applying a first color coating material by printing on the part of the refractive/reflective layer in the pattern form, and curing the first color coating material, [100] after the step (A-8) and before the step (A-9), after the step (B-13) and before the step (B- 14), or after the step (C-14) and before the step (C-15). [101] According to another embodiment of the invention, the process further comprises the step of: [102] (A- 14) printing patterns using a second color coating material on the pattern form, and curing the second color coating material, [103] after the step (A-7) and before the step (A-8), after the step (B- 12) and before the step (B-13), and after the step (C-13) and before the step (C-14). [104] The second color coating material may have a refractive index which differs in value by 0.3 or less from that of the UV-curable resin for pattern form. [105] According to another embodiment of the invention, the process further comprises the steps of: [106] (A-15) applying a first color coating material by printing on a part of thepattern form, and curing the first color coating material and [107] (A- 16) removing any unprinted part of the refractive/reflective layer on the pattern form using an etching solution, [108] after the step (A-8) and before the step (A-9), after the step (B-13) and before the step (B- 14), or after the step (C- 14) and before thestep (C-15).

[109] The refractive/reflective layer may be formed of a material having a refractive index which is greater in value by 0.3 or more, preferably by 0.3 to 3.0, compared with that of the UV-curable resin for pattern form.

[110] The material having a refractive index which is greater in value by 0.3 or more compared with that of the UV-curable resin for pattern form, may be selected from the group consisting of titanium(IV) oxide (TiO ), zinc(II) oxide (ZnO), cerium(IV) oxide (CeO ), zirconium(IV) oxide (ZrO ), zinc(II) sulfide (ZnS), cadmium(II) sulfide (CdS), zinc(II) selenide (ZnSe), lanthanum sesquioxide (La O ), indium tin oxide (In O DSnO ), and diamond.

[I l l] The refractive/reflective layer may be formed of a material selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt) and rhodium (Rh).

[112] The thickness of the refractive/reflective layer may be 100 to 12,000 A.

[113] Meanwhile, according to another aspect of the present invention, there is provided a patterned decorative material produced by any of the processes described above.

[114] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[115] First, some of the terms used in the current specification will be defined.

[116] The term "actinic energy ray" as used herein refers to any particle beam or electromagnetic wave, having a sufficient amount of energy to cure a predetermined resin, and may be exemplified by UV rays, laser, microwave, electron beam, X-ray or the like.

[117] The term "UV-curable molding resin" refers to a resin which can be cured by UV rays, and which serves as the raw material of a patterning mold which forms a pattern form by contacting with the UV-curable resin for pattern form, which actually manifests a pattern image, as well as a replica master mold used for theformation of the pattern mold, a pre-mold and a base for forming base layers in a multilayer mold used for the formation of the patterning mold.

[118] The term "UV-curable resin for pattern form" refers to a resin which can be cured by UV rays, and which serves as the raw material of the pattern form, which actually manifests a pattern image.

[119] Finally, the term "refractive/reflective layer" as used herein refers to a layer which is formed on a pattern form and performs a function of helping the pattern form to manifest a pattern image more brightly and more clearly. This refractive/reflective layer is formed of a refractive material inducing refraction of light or a reflective material inducing reflection of light, and this refraction or reflection engenders manifestation of the pattern image with brightness and clarity. [120] Fig. 1 is a flow diagram of a process for producing a patterned decorative material using moldings of UV-curable resin according to the present invention.

[121] Referring to Fig. 1, a master mold 10 having a pattern form formed thereon is provided by conventionally known processes such as photolithography, etching and the like. Then, a UV-curable molding resin 20 for patterning mold is applied on the master mold 10, and a support 30 which can transmit UV rays, such as a polyethylene terephthalate film, a urethane film or the like, is attached on the UV-curable molding resin 20 for patterning mold [Process (a)].

[122] One feature of the present invention lies in that UV-curable resins are used as the material for molds for forming pattern forms, which directly manifest pattern images, including replica master mold, pre-mold, base and the like.

[123] A UV-curable resin means a resin which is cured by UV rays, and is one of actinic energy ray-curable resins. Conventionally, resins are predominantly cured by heating. However, thermal curing is likely to generate cracks under the actions of the volumetric contraction attributable to the thermal expansion caused by temperature difference between the maximum heating temperature and the ambient temperature during cooling, and also of the volumetric contraction attributable to the curing reaction itself, thus it being difficult to obtain precise dimensions for a product. Furthermore, the thermal residual stress generated during the thermal curing process shortens the life span of elements, and the curing process requires a largequantity of heat energy and a long processing time, thus setting limits to the size of molding products.

[124] In contrast, the actinic energy ray-curable resins including UV-curable resins are not affected by the aforementioned problems of the thermal curing process, such as crack generation, low precision, thermal residual stress and the like, while the curing process utilizing actinic energy rays consumes much less energy and time, and is not limited in the size of molding products. Thus, the actinic energy ray-curable resins are being employed in an increasing range of applications.

[125] The present invention employs, among such actinic energy ray-curable resins, UV- curable resins which are cured by UV rays, as the raw material for molds.

[126] A conventional UV-curable resin isprepared by providing a resin monomer such as epoxy acrylate, novolac acrylate, unsaturated polyester, vinyl ester or the like, adding an initiator such as 1 -hydroxy cyclohexyl phenyl ketone, hydroxyl phenyl ketone or the like, and irradiating UV rays.

[127] Meanwhile, a UV-curable molding resin of thepresent invention can use a material prepared by adding, in addition to a photoinitiator, an acrylate compound to a mixture of different urethane acrylate oligomers, so as to impart properties such as re- leasability, flexibility and the like to a conventional UV-curable resin. A specific example of the mixture of different urethane acrylate oligomers added acrylate compounds is a mixture of the following components:

[128] (a) 20% by weight of a urethane acrylate oligomer formed by a urethane reaction between 2 equivalents of hydroxyethyl acrylate and 1 equivalent of 1 ,6-diisocyanatohexane

[129] (b) 25% by weight of a urethane acrylate oligomer formed by a urethane reaction between 3 equivalents of hydroxypropyl acrylate and 1 equivalent of a trivalent tri- isocyanate having a isocyanurate structure of isophorone diisocyanate;

[130] (c) 20% by weight of a urethane acrylate oligomer formedby a urethane reaction between 3 equivalents of hydroxypropyl acrylate and 1 equivalent of a trivalent tri- isocyanate having a isocyanurate structure of trimethylhexamethylene diisocyanate;

[131] (d) 20% by weight of neopentylglycol diacrylate;

[132] (e) 10% by weight of hydroxypropyl acrylate; and

[133] (f) 5% by weight of 2-hydroxy-2-methyl- 1 -phenyl- 1-propanone (photoinitiator).

[134] The support 30 is pressed toward the master mold 10 at a pressure of 0.5 to 3 bar, and is irradiated with UV rays to cure the UV-curable molding resin 20 for patterning mold and to form a patterning mold 40 [Process (b)].

[135] The patterning mold 40 bonded with the support 30 is separated from the master mold 10 [Process (c)].

[136] In a separate process, a UV-curable resin for pattern form 21 is applied onto a substrate 35, and the patterning mold 40 is pressed against the UV-curable resin for pattern form 21 [Process (d)].

[137] Another feature of the present invention is that, in addition to the use of UV-curable resins for molds including replica master mold and the like as described above,UV-curable resins are also used as the material for pattern form, which is actually used to develop pattern images. The pattern form of the invention can be applied to a variety of substrates, includingpolyethylene terephthalate films, urethane films, other plastic films, polycarbonate (PC) sheets, acrylic sheets, metal sheets formed of stainless steel such as SUS, copper, aluminum and the like, glass sheets, and the like. In particular, it is preferable to use different UV-curable resins for pattern form respectively for hard type substrates and flexible type substrates, in accordance with the properties of thesubstrate. The fundamental concept of adding acrylate to urethane acrylate oligomers is equally applicable to the material of pattern form of theinvention, as is for the materials of molds of the invention.

[138] Specifically, in the case of forming a pattern form on a hard type substrate such as an acrylic sheet or an SUS sheet, which is a type of stainless steel sheet,it may be desirable to use a mixture of the following components:

[139] (g) 50% by weight of a urethane acrylate oligomer formed by adding 30 parts by weight of 2-hydroxypropyl acrylate to 100 parts by weight of a reaction mixture containing 1 equivalent of pentaerythritol triarylate and 0.9 equivalent of isophorone diisocyanate, diluting the reaction mixture, and allowing the reaction mixture to react;

[140] (h) 25% by weight of dipentaerythritol triacrylate;

[141] (i) 20% by weight of trimethanolpropane triacrylate; and

[142] (j) 5% by weight of 1 -hydroxy cyclohexyl phenyl ketone (photoinitiator).

[143] Also, in the case of forming a pattern form on a flexible type substrate such as a polyethylene terephthlate (PET) film, it may be desirable to use a mixture of the- following components:

[144] (k) 60% by weight of a urethane acrylate oligomer formed by reacting 1 equivalent of dihydroxy-functional polymethacrylate polyol with 2 equivalents of isophorone diisocyanate trimer, and further reacting the isocyanate reaction product thus obtained with 1.1 equivalent of hydroxypropyl acrylate;

[145] (1) 20% by weight of hexanediol diacrylate;

[146] (m) 15% by weight of trimethylolpropane nonaethoxylated triacrylate; and

[147] (j) 5% by weight of 1 -hydroxy cyclohexyl phenyl ketone (photoinitiator).

[148] The UV-curable resin for pattern form 21 contacted with the patterning mold 40 is irradiated with UV rays, and is cured to form a pattern form 50 [Process (e)].

[149] The pattern form 50 bonded to the substrate 35 is separated from the patterning mold 40 [Process (f)].

[150] A refractive material inducing refraction of light or a reflective materialinducing reflection of light is deposited on the pattern form 50 using an electron beam evaporator or the like, to form a refractive/reflective layer 60 [Process (g)]. This refractive/reflective layer 60 allows a pattern image to be manifested more clearly and brightly so that apattern image of high brightness or ultrahigh brightness intended by the present invention can be realized, and the refractive/reflective layer 60 also allows prevention of damages to the pattern form 50, which may result from further processes of overcoating or printing.

[151] In the case where the material forming this refractive/reflective layer 60 is a refractive material, the refractive index of the refractive material is preferably greater in value by 0.3 or more, and more preferably by 0.3 to 3.0, compared with that of the UV-curable resin for pattern form 21. The refractive material may be selected from the group consisting of titanium (IV) oxide (TiO ), zinc (II) oxide (ZnO), cerium (IV) oxide (CeO ), zirconium (IV) oxide (ZrO ), zinc (II) sulfide (ZnS), cadmium (II) sulfide (CdS), zinc (II) selenide (ZnSe), lanthanum sesquioxide (La O ), indium tin oxide ( ^VIn 2 O 3 DSnO l)' and diamond.

[152] On the other hand, in the case wherethe material forming the refractive/reflective layer 60 is a reflective material, the reflective material is preferably a metal used in mirror coating or the like, and may be selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt) and rhodium (Rh). [153] The thickness of the refractive/reflective layer 60 is preferably 100 to 12,000 A. If the thickness is less than 100 A, the pattern image has low brightness, and it becomes difficult to obtain clear images. If the thickness is larger than 12,000 A, the material costs and processing time are unnecessarily increased, and the material at the outermost part of the deposited layer may fall off because of the limited adhesive power of the material.

[154] The surface of the refractive/reflective layer 60 is coated with an overcoat 70 using an overcoating agent such as a UV-curable or thermally curable resin, an adhesive or thelike, to a thickness greater than the irregularities of the patterned form 50 [Process (h)]. This overcoating agent is preferably an organic or inorganic material having a refractive index which differs in value by 0.3 or less from that of the UV-curable resin for pattern form 21.

[155] The role of the overcoat 70, excluding an overcoat composed of adhesive, is to protect the pattern form 50 from external impacts or contamination by moisture or the like.

[156] Fig. 2 is a flow diagram of a process for producing a patterned decorative material, in which a pattern form is selectively formed only on a part of thesurface of a substrate, according to an embodiment of the invention.

[157] In the patterning mold 40 bonded with the support 30 as produced in the above- described Process (c) of Fig. 1, a part of the rear surface of the support 30 or a part of the patterned surface of the patterning mold 40 is color coated by printing, thusa mask 80 being formed [Process (d)]. The printing techniques that can be used for the present invention include silk printing, off-set printing and the like, which are well known in the art.

[158] Moreover, it is also possible to form a mask 80 by depositing an opaque metal instead of color coating, and preferred examples of such opaque metal include aluminum (Al), chromium (Cr), nickel (Ni), silver (Ag), gold (Au) or copper (Cu). The thickness of the opaque metal deposit layer is preferably 0.1 to 2 D. If the thickness is less than 0.1 D, the effect of masking UV rays may not be sufficient, and thus, there is a risk that even the UV-curable resin for pattern form in the regions where manifestation of pattern image is unnecessary, would be cured. If the thickness is greater than 2 D, the materialcosts and processing time are unnecessarily increased, and the material at the outermost part of the deposited layer may fall off because of the limited adhesive power of the material.

[159] In a separate process, the patterning mold 40 having the mask 80 formed thereon is pressed againstthe UV-curable resin for pattern mold 21 applied on the substrate 35 [Process (e)],and UV rays are irradiated to cure the UV-curable resin for pattern form 21 [Process (f)]. Then, the presence of the mask 80 prevents transmission of UV rays, and thus, an uncured portion of the UV-curable resin for pattern form 21 remains on the substrate 35 in between cured regions of the pattern form 50 [Process (g)].

[160] This uncured portion of the UV-curable resin for pattern form 21 is removed by dissolving in a solvent [Process (h)], and only the pattern form 50 is left on the substrate 35. In this process, the solvent used isa ketone or an alcohol, and according to the present invention, a mixed solvent containing 10 to 90% by weight of methyl ethyl ketone, and 10 to 90% by weight of methyl isobutyl ketone is preferred. The pattern form on substrate is immersed in the solvent for 15 to 60 seconds with shaking, to remove the uncured portion of the UV-curable resin for pattern form 21. If the dissolution time taken by theuncured resin in the solvent is less than 15 seconds, the uncured resin portion may not be sufficiently removed and may remain as residues. If the dissolution time exceeds 60 seconds, the processing time may be unnecessarily increased.

[161] On the pattern form 50 formed on the substrate 35 during the Process (h), deposition of the refractive/reflective layer 60 and application of the overcoat 70 are performed as described above with reference to Fig. 1, thus to selectively manifest a pattern images.

[162] Fig. 3 is a flow diagram of a process for producing a patterned decorative material, inwhich a pattern image is selectively manifested only in a part of the surface of a pattern form, according to another embodiment of the invention.

[163] In the case of manifesting a pattern image on a mobile phone window, a pattern form 50 is formed on a substrate 35 formed of an acrylic resin or the like [Process (f)], and then a part of thepatterned surface is shielded with a shadow mask 85 [Process (g)] . Subsequently, a refractive/reflective layer 60 is deposited on the patterned surface, and then the shadow mask 85 is removed, so that the refractive/reflective layer 60 is deposited only partially on the surface of the pattern form 50 [Process (h)].

[164] Thereafter, a first color coating material 90 is printed on the part where the refractive/reflective layer 60 has been deposited, and the first color coating material 90 is cured [Process (i)]. An overcoat 70 is then applied thereon, so that the pattern image can bemanifested only in a part of the mobile phone window [Process (J)]. Printing of thefirst color coating material can also be performed by silk printing, off-set printing or thelike, which are well known in the art.

[165] Fig. 4 is a flow diagram of a process for producing a patterned decorative material, in which patterns are imprinted on a part of the surface of a pattern form, according to another embodiment of the invention. [166] After forming a pattern form 50 on a substrate 35 [Process (f)], a second color coating material 95 is printed on the pattern form 50 to a thickness larger than the irregularities of thepattern form 50, and the second color coating material 95 is cured, thus to imprint patterns such as characters, logos or figures on the pattern form 50 [Process (g)]. This second color coating material 95 is preferably a material having a refractive index which differs in value by 0.3 or less from that of the UV-curable resin for pattern form 21. Printing of the second color coating materialcan also be performed by silk printing, off-set printing or the like, which are well known in the art.

[167] A part of the patterned surface on which patterns have been thus imprinted is then shielded with a shadow mask 85 as described above [Process (h)], and then deposition of a refractive/reflective layer 60 [Process (i)], printing and curing of a first color coating material 90 [Process (j)], and application of an overcoat 70 [Process (k)] are performed sequentially, thus to produce a patterned decorative material with imprinted patterns.

[168] Fig. 5 is a flow diagram of a process for producing a patterned decorativematerial, in which a pattern image is selectively manifested only in a part of the surface of a pattern form, according to another embodiment of the invention.

[169] After forming a pattern form 50 on a substrate 35 [Process (f)], a refractive/ reflective layer 60 is deposited over the entire area of the patterned surface [Process (g) ], and then a first color coating material 90 is printed only in a predetermined region where the pattern image is to be manifested, and the first color coating material 90 is cured [Process (h)].

[170] Next, the substrate 35 is immersed in an etching solution to remove the refractive/ reflective layer 60 in the region not printed with the first color coating material 90 [Process (i)], and then an overcoat 70 is applied thereon [Process (j)]. A representative example of the etching solution is an etching solution containing ferric chloride (FeCl

)•

[171] Through the process as described above, there can be produced a mobile phone window in which a pattern image is manifested only in the part where deposition of a refractive/reflective layer 60 and application of a first color coating 90 have been carried out, in a pattern form 50 formed on a substrate 35, with the remaining part which has been coated with an overcoat 70, being able to clearly transmit the visual information data shown in the window.

[172] Fig. 6 is a flow diagram of a process for producing a patterned decorative material, in which an elastic mold is used, according to another embodiment of the invention.

[173] A UV-curable molding resin 20 for replica master mold is applied on a master mold

10 on which a pattern form has been formed by conventional photolithography and etching processes, and then a support 30 formed of a polyethylene terephthalate film or the like is attached to the UV-curable molding resin 20 for replica master mold [Process (a)].

[174] The support 30 is pressed toward the master mold 10, and UV rays areirradiated thereon to cure the UV-curable molding resin 20 for replica master mold, and to form a replica master mold 15 [Process (b)].

[175] The replica master mold 15 bonded with the support 30 is separated from the master mold 10 [Process (c)].

[176] In a separate process, a UV-curable molding resin 20 for pre-mold is applied on a substrate 35, and the replica master mold 15 is pressed against the UV-curable molding resin 20 for pre-mold [Process (d)].In this case, to enhance adhesiveness between the UV-curable molding resin 20 for pre-mold and the substrate 35, a primer can be applied on the substrate 35 prior to applying the UV-curable molding resin 20 for pre- mold. Representative examples of this primer include acrylate oligomers containing phosphoric acid, carboxylic acid or alcohol functionality; UV-curable resins mainly containing reactive monomers and diluting solvents, and the like. The substrate in this case is preferably a glass substrate.

[177] The UV-curable molding resin 20 for pre-mold contacted with the replica master mold 15 is irradiated with UV rays to be cured, and thus a pre-mold 43 is formed [Process (e)].

[178] The pre-mold 43 bonded to the substrate 35 is separated from thereplica master mold 15 [Process (f)]. The pre-mold 43 is then placed in a mold frame 39 provided in advance, and an elastic material is poured on the pre-mold 43, air bubbles are eliminated, and then the elastic material is heated to yield an elastic mold 46 [Process (g)]. Here, an elastic material is a material having low surface energy, which can be easily separated from the pre-mold 43 and the patterning mold 40, as described later. A representative example of theelastic material is a mixture containing mainly poly- dimethylsiloxane (PDMS) and known additives such as a curing agent. The elastic material undergoes a thermal curing process to become an elastic mold 46 as described previously.

[179] The elastic mold 46 thus produced is separated from thepre-mold 43 [Process (h)].

In a separate process, a UV-curable molding resin 20 for patterning mold is applied on a support 30, and then the elastic mold 46 is pressed against the UV-curable molding resin 20 for patterning mold [Process (i)].

[180] The UV-curable molding resin 20 for patterning mold contacted with the elastic mold 46 is irradiated with UV raysto be cured, and thus a patterning mold 40 is formed [Process (J)].

[181] The patterning mold 40 bonded to the support 30 is separated from the elastic mold

46 [Processes (k, I)], and a UV-curable resin for pattern form 21 is applied on a separate substrate 35, after which the patterning mold 40 is pressed against the UV- curable resin for pattern form 21 [Process (m)].

[182] The UV-curable resin for pattern form 21 contacted with the patterning mold 40 is irradiated with UV raysto be cured, and thus a pattern form 50 is formed [Process (n)].

[183] The pattern form 50 bonded to the substrate 35 is separated from the patterning mold 40 [Process (o)].

[184] A refractive/reflective layer 60 is deposited on the pattern form 50 [Process (p)], and an overcoat is applied thereon [Process (q)]. In particular, in the case where the pattern form 50 of the invention is an insert-in-mold type pattern form for mobile phone casings, a thermally curable adhesive is used as the overcoating agent, which is to be bonded to mobile phone casing formed of polycarbonate or an acrylic material, by instant thermal pressing at 180 ⁰C to 230 ⁰C.

[185] Even in the case of producing patterned decorative materials using such elastic mold 46, processes such as partial curing using the aforementionedmask 80 shown in Fig. 2, partial deposition of the refractive/reflective layer 60 using the shadow mask 85 shown in Fig. 3a, imprinting of patterns using the second color coating material 95 shown in Fig. 3b, and/or partial removal of the refractive/reflective layer 60 using the etching solution shown in Fig. 3c, can be also used.

[186] Fig. 7 is a flow diagram of a process for producing a patterneddecorative material, in which a patterning mold is formed in a multilayer form, according to another embodiment of the invention.

[187] To examine the process of forming a patterning mold in a multilayer form, a UV- curable molding resin 20 for base is first applied on a support 30, and is irradiated with UV rays to be pseudo-cured, and thus a base 20' is formed [Process (a)]. Here, the term "pseudo-cured" should be distinguished from the term "cured", since in a pseudo- curing process, an actinic energy is irradiated at a dose approximatingto one-third of the usual dose required in normal curing, and the pseudo-cured surface is not completely cured,but cured to a state in which the resin does not dissolve in a solvent and remains tacky.

[188] A UV-curable molding resin 20 for patterning mold is applied again on the pseudo- cured base 20', and a replica master mold 15 or elastic mold 46, which is bonded to a separate support 30, is pressed against the UV-curable molding resin 20 for patterning mold [Process (b)].

[189] The UV-curable molding resin 20 for patterning mold contacted with the replica master mold 15 or elastic mold 46 is irradiated with UV rays to be cured, and thus a patterning mold 40 is formed [Process (c)].

[190] The patterning mold 40 bonded to the support 30 is separated from the replica master mold 15 or elastic mold 46, and thus a multilayer mold 40 of the invention is produced [Process (d)].

[191] This multilayer mold 40 has enhanced durability as a patterning mold, and can be used in forming a much larger number of pattern forms 50, compared with a single- layer mold, thus being advantageous in lowering the production costs and making the production process simple.

Advantageous Effects

[192] According to the present invention, a patterning mold formed of a synthetic resin can be produced as a replica of a master mold and used in the production of patterned decorative materials, instead of directly using conventional patterned master molds.

Thus, a pattern form can be transferred to various base materials conveniently at low costs, and also,no scars or defects are generated on the surfaces of the base materials.

Therefore, it is possible to use the patterning mold repeatedly for a long time, with additional advantages such as high economic efficiency, formation of pattern form of high quality and high brightness, and easy increment of the dimension of pattern form.

Brief Description of the Drawings [193] Fig. 1 is a flow diagram of aprocess for producing a patterned decorative material using moldings of UV-curable resin according to the present invention. [194] Fig. 2 is a flow diagram of a process for producing a patterned decorative material, in which a pattern form is selectively formed only on a part of thesurface of a substrate, according to an embodiment of the invention. [195] Fig. 3 is aflow diagram of a process for producing a patterned decorative material, in which a pattern image is selectively manifested only in a part of the surface of a pattern form, according to another embodiment of the invention. [196] Fig. 4 is a flow diagram of a process for producing a patterned decorative material, in which patterns are imprinted on a part of the surface of a pattern form, according to another embodiment of the invention. [197] Fig. 5 is a flow diagram of a process for producing a patterned decorative material, in which a pattern image is selectively manifested only in a part of thesurface of a pattern form, according to another embodiment of the invention. [198] Fig. 6 is a flow diagram of a process for producing a patterned decorative material, in which an elastic mold is used, according to another embodiment of theinvention. [199] Fig. 7 is a flow diagram of a process for producing a patterned decorative material, in which a patterning mold is formed in a multilayer form, according to another embodiment of the invention.

Mode for the Invention [200] The following Examples are given for illustrative purposes only, and the present invention is not limited by the Examples. [201]

[202] EXAMPLES

[203] EXAMPLE 1 : Production of SUS decorative material for mobile phones

[204] A master mold wasproduced by forming a pattern form on a silicon substrate, and a

UV-curable molding resin for patterning mold wasapplied on the master mold, the UV- curable molding resin for patterning mold being a mixture comprising (a) 20% by weight of a urethane acrylate oligomer prepared by a urethane reaction between 2 equivalents of hydroxy ethyl acrylate and 1 equivalent of 1,6-diisocyanatohexane; (b) 25% by weight of a urethane acrylate oligomer prepared by a urethane reaction between 3 equivalents of hydroxypropyl acrylate and 1 equivalent of a trivalent tri- isocyanate having a isocyanurate structure of isophorone diisocyanate; (c) 20% by weight of a urethane acrylate oligomer prepared by a urethane reaction between 3 equivalents of hydroxypropyl acrylate and 1 equivalent of a trivalent triisocyanate havinga isocyanurate structure of trimethylhexamethylene diisocyanate; (d) 20% by weight of neopentylglycol diacrylate; (e) 10% by weight of hydroxypropyl acrylate; and (f) 5% by weight of 2-hydroxy-2-methyl-l -phenyl- 1-propanone (photoinitiator). Then, a polyethylene terephthalate (PET) film having a thickness of 188 D was attached on the UV-curable molding resin for patterning mold.

[205] The UV-curable molding resin for patterning mold was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 30 seconds, to form a patterning mold.

[206] The cured patterning mold was separated from the master mold, and then a predetermined region on the patterned surface of the patterning mold, where the pattern image would not be manifested, was color coated in black, by a silk printing method.

[207] Apart from this, an SUS-based metal substrate was washed at the surface with hexane, and then a transparent UV-curable resin for pattern form was applied on the washed surface of the metal substrate, the transparent UV-curable resin for pattern form comprising (g) 50% by weight of a urethane acrylate oligomer formed by adding 30 parts by weight of 2-hydroxypropylacrylate to 100 parts by weight of a reaction mixture containing 1 equivalent of pentaerythritol triacrylate and 0.9 equivalent of isophorone diisocyanate, dilutingthe reaction mixture, and allowing the reaction mixture to react; (h) 25% by weight of dipentaerythritol triacrylate; (i) 20% by weight of trimethanolpropane triacrylate; and (j) 5% by weight of 1 -hydroxy cyclohexyl phenyl ketone (photoinitiator). Then, the patterning mold was pressed against the transparent UV-curable resin for pattern form.

[208] The transparent UV-curable resin for pattern form was cured by irradiating with a high pressure mercury lamp (wavelength 250 nm) having an intensity of 450 mW/cm under a pressure of 1 bar for 30 seconds, to form a pattern form. [209] After separating and removing the patterning mold, the SUS substrate with a pattern form formed thereon was immersed in a mixed solvent containing 50% by weight of methyl ethyl ketone and 50% by weight of methyl isobutyl ketone, and was shaken for 30 seconds, thus to remove the uncured portion of the transparent UV-curable resin for pattern form generated by the silk-printed black color coating on the surface of the patterning mold. The SUS substrate was dried under dry air or nitrogen.

[210] Nickel was deposited on the patterned surface of the SUS substrate, on which the pattern form was selectively formed, to a thickness of 1000 A, using an electron beam evaporator.

[211] A transparent UV-curable resin, which was a mixture containing 60% by weight of a urethane acrylate oligomer formed by adding 2-hydroxypropyl acrylate to a reaction mixture of pentaerythritol tetraacrylate and isophorone diisocyanate, diluting the reaction mixture, and allowing the reaction mixture to react; 35% by weight of dipen- taerythritol hexaacrylate; and 5% by weight of 1 -hydroxy cyclohexyl phenyl ketone, was applied by spraying on the nickel deposit layer as an overcoating agent. Then, the transparent UV-curable resin was cured by irradiating with a high pressure mercury lamp (wavelength 250 nm) having an intensity of 450 mW/cm for 30 seconds, and thus a patterned decorative material according to the present invention was produced.

[212] EXAMPLE 2a: Production of acrylic decorative material for mobile phone windows (T)

[213] A master mold was produced by forming a pattern form on a silicon substrate, and a

UV-curable molding resin for patterning mold having the same composition as that used in Example 1 was applied on the master mold. Then, a polyethylene terephthalate (PET) film having a thickness of 188 D was attached on the UV-curable molding resin for patterning mold.

[214] The UV-curable molding resin for patterning mold was cured by irradiating with a

[215] The cured patterning mold was separated from the master mold. Apart from this, a transparent UV-curable resin for pattern form having the same composition as that used in Example 1 was applied on an acrylic substrate for mobile phone windows. Then, the patterning mold was pressed against the transparent UV-curable resin for pattern form.

[216] The transparent UV-curable resin for pattern form was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 15 seconds, to form a pattern form.

[217] After separating and removing the patterning mold, a predetermined region in the patterned surface of the pattern form on the acrylic substrate for window, where the pattern image would not be manifested, was shielded with a shadow mask. Titanium dioxide (TiO ) was deposited on the patterned surface to a thickness of 500 A, using an electron beam evaporator. [218] Hac ink (Seint Co., Ltd.), which is a thermally curable color coating material, was silk-printed on the titanium dioxide deposit layer where the pattern image would be manifested, and was thermally cured at 60 ⁰C for 1 hour. [219] A thermally curable transparent overcoating agent, SF-7 (SSCP Co., Ltd.), was applied over the entire patterned surface of the acrylic substrate, and was thermally cured at 60 ⁰C for 1 hour. Thus, a patterned decorative material according to the present invention was produced. [220] EXAMPLE 2b: Production of acrylic decorative material for mobile phone windows (TD [221] A master mold was produced by forming a pattern form on a silicon substrate, and a

UV-curable molding resin for patterning mold having the same composition as that used in Example 1 was applied on the master mold. Then, a polyethylene terephthalate film having a thickness of 188 D was attached on the UV-curable molding resin for patterning mold. [222] The UV-curable molding resin for patterning mold was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 30 seconds, to form a patterning mold. [223] The cured patterning mold was separated from the master mold. Apart from this, a transparent UV-curable resin for pattern form having thesame composition as that used in Example 1 was applied on an acrylic substrate for mobile phone windows. Then, the patterning mold was pressed against the transparent UV-curable resin for pattern form. [224] The transparent UV-curable resin for pattern form was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 15 seconds, to form a pattern form. [225] After separating and removing the patterning mold, Hac ink (Seint Co., Ltd.), which is a thermally curable color coating material, was silk-printed to form patterns on a portion in the patterned surface of the pattern form, and was thermally cured by heating at 67 ⁰C for 30 minutes. [226] A predetermined region in the patterned surface of the pattern form on the acrylic substrate for window, where the pattern image would not be manifested, was shielded with a shadow mask, and then titanium dioxide was deposited on the patterned surface to a thickness of 500 A, using an electron beam evaporator. [227] Hac ink (Seint Co., Ltd.), which is a thermally curable color coating material, was silk-printed on the titanium dioxide deposit layer where the pattern image would be manifested, and was thermally cured at 60 ⁰C for 1 hour. [228] A thermally curable transparent overcoating agent, SF-7 (SSCP Co., Ltd.), was applied over the entire patterned surface of the acrylic substrate, and was thermally cured at 60 ⁰C for 1 hour. Thus, a patterned decorative material according to the present invention was produced.

[229] EXAMPLE 2c: Production of acrylic decorative material for mobile phone windows (III)

[230] A master mold was produced by forming a pattern form on a silicon substrate, and a

UV-curable molding resin for patterning mold having the same composition as that used in Example 1 was applied on the master mold. Then, a polyethylene terephthalate film having a thickness of 188 D was attached on the UV-curable molding resin for patterning mold.

[231] The UV-curable molding resin for patterning mold was cured by irradiating with a

[232] The cured patterning mold was separated from the master mold. Apart from this, a transparent UV-curable resin for pattern form having thesame composition as that used in Example 1 was applied on an acrylic substrate for mobile phone windows. Then, the patterning mold was pressed against the transparent UV-curable resin for pattern form.

[233] The transparent UV-curable resin for pattern form was cured by irradiating with a

[234] After separating and removing the patterning mold, titanium dioxide was deposited to a thickness of 500 A over the entire patterned surface on the acrylic substrate, using an electron beam evaporator.

[235] Hac ink (Seint Co., Ltd.), which is a thermally curable color coating material, was silk-printed on the titanium dioxide deposit layer, excluding the window region where the pattern image would not be manifested, and was thermally cured at 60 ⁰C for 1 hour.

[236] Then, the acrylic substrate having a pattern form formed thereon was immersed in an etching solution containing ferric chloride (FeCl ) to remove titanium dioxide that was deposited on the window region where the color coating material was not silk- printed.

[237] A thermally curable transparent overcoating agent, SF-7 (SSCP Co., Ltd.), was applied over the entire patterned surface of the acrylic substrate, and was thermally cured at 60 ⁰C for 1 hour. Thus, a patterned decorative material according to the present invention was produced.

[238] EXAMPLE 3: Production of insert-in-mold type mobile phone casing

[239] A master mold was produced by forming a pattern form on a silicon substrate, and a UV-curable molding resin for replica master mold having the same composition as that used in Example 1 was applied on the master mold. Then, a polyethylene terephthalate film having a thickness of 188 D was attached on the UV-curable molding resin for replica master mold.

[240] The UV-curable molding resin for replica master mold was cured by irradiating with a UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 30 seconds, to form a replica master mold.

[241] After separating the cured replica master mold from the master mold, a predetermined portion of the patterned surface of the replica master mold, wherein the pattern image would not be manifested, was color coated by silk printing.

[242] Apart from this, a primer for enhancing adhesiveness was formed by diluting a uniform mixture containing 40% by weight of a urethane acrylate oligomer obtained fr om a reaction between pentaerythritol triacrylate, isophorone diisocyanate and 2-hydroxypropyl acrylate; 15% by weight of dipentaerythritol hexaacrylate; 20% by weight of pentaerythritol triacrylate; 10% by weight of hydroxypropyl acrylate; 10% by weight of phosphate methacrylate; and 5% by weight of 1-hydroxycyclohexyl phenyl ketone, with a 20-fold volume of propylene glycol methyl ether acetate. This primer was applied on a glass substrate, and then a transparent UV-curable molding resin for pre-mold having the same composition as that used in Example 1 was applied thereon. The replica master mold previously formed was pressed against the transparent UV-curable molding resin for pre-mold.

[243] The UV-curable molding resin for pre-mold was cured by irradiating with a UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 30 seconds, to form a pre-mold.

[244] After separating and removing the pre-mold, the glass substrate having the pre- mold formed thereon was immersed in a mixed solvent containing 50% by weight of methyl ethyl ketone and 50% by weight of methyl isobutyl ketone, and was shaken for 30 seconds, to remove the uncured portion of the transparent UV-curable molding resin for pre-mold generated by the silk-printed color coatingon the surface of the pre- mold. The glass substrate was dried under dry air or nitrogen.

[245] The glass substrate having the pre-mold formed thereon was placed in a mold frame. Then, Sylgard ®

184 (Dow Chemical Company) was poured into the mold frame, removed of air bubbles, and thermally cured at 80 ⁰C for 1.5 hours, thus to form an elastic mold.

[246] After separating the elastic mold from the pre-mold, theelastic mold was pressed against the UV-curable molding resin for patterning mold having the same composition as that used in Example 1, which mold resin had been applied on the 188 D -thick polyethylene terephthalate film.

[247] The UV-curable molding resin for patterning mold was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 10 minutes, to form a patterning mold.

[248] The patterning mold was separated from the pre-mold. Apart from this, a transparent UV-curable resin for pattern form was applied on a polyethylene terephthalate film substrate for insert-in-mold type mobile phone casings, the transparent UV-curable resin for pattern form being a mixture comprising (k) 60% by weight of a urethane acrylate oligomer formed by reacting 1 equivalent of dihydroxy- functional polymethacrylate polyol with 2 equivalents of isophorone diisocyanate trimer, and further reacting the resulting isocyanate reaction product with 1.1 equivalents of hydroxypropyl acrylate; (1) 20% by weight of hexanediol diacrylate; (m) 15% by weight of trimethylolpropane nonaethoxylated triacrylate; and (j) 5% by weight of 1 -hydroxy cyclohexyl phenyl ketone (photoinitiator). Then, the patterning mold was pressed against the transparent UV-curable resin for pattern form.

[249] The transparent UV-curable resin for pattern form was cured by irradiating with a

UV fluorescent lamp (wavelength 352 nm) having an intensity of 8 mW/cm under a pressure of 1 bar for 30 seconds, to form a pattern form.

[250] Aluminum (Al) was deposited to a thickness of 1000 A on the patterned surface of the polyethylene terephthalate substrate with the pattern form formed thereon, using an electron beam evaporator.

[251] A thermally curable adhesive, EPK0151 (Dexter Hysol Aerospace, Inc.), was overcoated on the aluminum deposit layer, and then the overcoated polyethylene terephthalate substrate was adhered to a mobile phone casing formed of an acrylic material by instant thermal pressing at 200 ⁰C.

[252] Thus far, preferred examples of the present invention have been illustrated and described, but the present invention is not intended to be limited by these particular examples. Those having ordinary skill in the art to which the present invention is pertained will understand that various modifications of the present invention are possible without departing from the spirit and scope of the present invention, and that such modifications are within the scope of the claims of the present invention.

Claims

[1] A process for producing a patterned decorative material, the process comprising the steps of:

(A-I) applying an ultraviolet (UV)-curable molding resin for patterning mold on a master mold having a pattern form formed thereon;

(A-2) attaching a support onto the UV-curable molding resin for patterning mold;

(A-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for patterning mold and to form a patterning mold;

(A-4) separating the patterning mold from the master mold;

(A-5) applying a UV-curable resin for pattern form on a substrate;

(A-6) pressing the patterning mold against the UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form;

(A-7) separating the pattern form from the patterning mold;

(A- 8) forming a refractive/reflective layer on the pattern form; and

(A-9) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat. [2] The process according to claim 1, further comprising the step of:

(A- 10) color coating by printing on a part of the patterned surface of the patterning mold or on a part of the rear surface of the support, after the step (A-4) and before the step (A-6); and further comprising the step of:

(A-I l) removing any uncured portion of the UV-curable resin for pattern form by dissolving the uncured portion in a solvent, after the step (A-7) and before the step (A-8). [3] The process according to claim 1, further comprising the step of:

(A-IO') shielding a part of the patterned surface of the patterning mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the patterning mold or the support, after the step (A-4) and before the step (A-6); and further comprising the step of:

(A-I l) removing any uncured portion of the UV-curable resin for pattern form by dissolving the uncured portion in a solvent, after the step (A-7) and before the step (A-8). [4] A process for producing a patterned decorative material, the process comprising the steps of:

(B-I) applying a UV-curable molding resin for replica master mold on a master mold having a pattern form formed thereon; (B-2) attaching a support to the UV-curable molding resin for replica master mold;

(B-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for replica master mold and to form a replica master mold;

(B-4) separating the replica master mold from the master mold; (B-5) applying a UV-curable molding resin for base on a separate support; (B-6) irradiating UV rays on the UV-curable molding resin for base to pseudo- cure the UV-curable molding resin for base;

(B-7) applying a UV-curable molding resin for patterning mold on the pseudo- cured base;

(B-8) pressing the replica master mold against the UV-curable molding resin for patterning mold and irradiating UV rays, to cure the UV-curable molding resin for patterning mold and to form a patterning mold; (B-9) separating the patterning mold from the replica master mold; (B- 10) applying a UV-curable resin for pattern form on a substrate; (B-I l) pressing the patterning mold against the UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form;

(B- 12) separating the pattern form from the patterning mold; (B- 13) forming a refractive/reflective layer on the pattern form; and (B- 14) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat.

[5] The process according to claim 4, further comprising the step of:

(B- 15) color coating by printing on a part of the patterned surface of the replica master mold or on a part of the rear surface of the support, after the step (B-4) and before the step (B-8); and further comprising the step of:

(B- 16) removing any uncured portion of the UV-curable molding resin for patterning mold by dissolving the uncured portion in a solvent, after the step (B-9) and before the step (B-I l).

[6] The process according to claim 4, further comprising the step of:

(B- 15') shielding a part of the patterned surface of the replica master mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the replica master mold or the support, after the step (B-4) and before the step (B-8); and further comprising the step of:

(B- 16) removing any uncured portion of the UV-curable molding resin for patterning mold by dissolving the uncured portion in a solvent, after the step (B-9) and before the step (B-I l). [7] A process for producing a patterned decorative material, the process comprising the steps of:

(C-I) applying a UV-curable molding resin for replica master mold on a master mold having a pattern form formed thereon;

(C-2) attaching a support to the UV-curable molding resin for replica master mold;

(C-3) pressing the support toward the master mold and irradiating UV rays, to cure the UV-curable molding resin for replica master mold and to form a replica master mold;

(C-4) separating the replica master mold from the master mold; (C-5) applying a UV-curable molding resin for pre-mold on a substrate; (C-6) pressing the replica master mold against the UV-curable molding resin for pre-mold and irradiating UV rays, to cure the UV-curable molding resin for pre- mold and to form a pre-mold;

(C-7) separating the pre-mold to the replica master mold; (C-8) placing the substrate having the pre-mold formed thereon into a mold frame, and adding polydimethylsiloxane and a curing agent to the mold frame; (C-9) thermally curing the polydimethylsiloxane and curing agent to form an elastic mold;

(C-IO) separating the elastic mold from the pre-mold; (C-I l) applying a UV-curable resin for pattern form on a separate substrate; (C- 12) pressing the elastic mold against the UV-curable resin for pattern form and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form;

(C- 13) separating the pattern form from the elastic mold; (C- 14) forming a refractive/reflective layer on the pattern form; and (C- 15) applying an overcoat on the patterned surface of the pattern form, and curing the overcoat.

[8] The process according to claim 7, further comprising the step of:

(C- 16) color coating by printing on a part of the patterned surface of the replica master mold or on a part of the rear surface of the support, after the step (C-4) and before the step (C-6); and further comprising the step of: (C- 17) removing any uncured portion of the UV-curable molding resin for pre- mold by dissolving the uncured portion in a solvent, after the step (C-7) and before the step (C-8).

[9] The process according to claim 7, further comprising the step of:

(C- 16') shielding a part of the patterned surface of thereplica master mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the replica master mold or the support, after the step (C-4) and before the step (C-6); and further comprising the step of:

(C- 17) removing any uncured portion of the UV-curable molding resin for pre- mold by dissolving the uncured portion in a solvent, after the step (C-7) and before the step (C-8).

[10] The process according to claim 7, further comprising the step of:

(C- 18) applying a UV-curable molding resin for primer on a substrate after the step (C-4) and before the step (C-5), wherein the step (C-5) is replaced by the step of:

(C-5¹) applying a UV-curable molding resin for pre-mold on the UV-curable molding resin for primer.

[11] The process according to claim 7, further comprising the steps of:

(C- 19) applying a UV-curable molding resin for patterning mold on a support;

(C-20) pressing the elastic mold against the UV-curable molding resin for patterning mold, and irradiating UV raysto cure the UV-curable molding resin for patterning mold and to form a patterning mold; and

(C-21) separating the pattering mold from the elastic mold after the step (C-10) and before the step (C-I l), wherein the steps (C-12) and

(C- 13) are replaced by the steps of:

(C- 12') pressing the patterning mold against the UV-curable resin for pattern form, and irradiating UV rays, to cure the UV-curable resin for pattern form and to form a pattern form; and

(C- 13') separating the pattern form from the patterning mold.

[12] The process according to claim 11, further comprising the step of:

(C- 16) color coating by printing on a part of the patterned surface of the replica master mold or on a part of the rear surface of the support after the step (C-4) and before the step (C-6); and further comprising the step of: (C- 17) removing any uncured portion of the UV-curable molding resin for pre- mold by dissolving the uncured portion in a solvent after the step (C-7) and before the step (C-8).

[13] The process according to claim 11, further comprising the step of:

(C- 16') shielding a part of the patterned surface of thereplica master mold or a part of the rear surface of the support with a shadow mask, and depositing an opaque metal on the replica master mold or the support after the step (C-4) and before the step (C-6); and further comprising the step of: (C- 17) removing any uncured portion of the UV-curable molding resin for pre- mold by dissolving the uncured portion in a solvent after the step (C-7) and before the step (C-8). [14] The process according to claim 11, further comprising the step of:

(C- 18) applying a UV-curable molding resin for primer on a substrate, after the step (C-4) and before the step (C-5), wherein the step (C-5) is replaced by the step of:

(C-5¹) applying a UV-curable molding resin for pre-mold on the UV-curable molding resin for primer. [15] The process according to any one of claims 1, 4, 7 and 11, wherein the overcoat is formed of a material having a refractive index which differs in value by 0.3 or less from that of the UV-curable resin for pattern form. [16] The process according to any one of claim 2, 5, 8 and 12, wherein the color of the color coating in the step (A- 10), (B- 15), or (C- 16) is black. [17] The process according to any one of claims 2, 3, 5, 6, 8, 9, 12 and 13, wherein the solvent used in the step (A-I l), (B- 16) or (C- 17) is a ketone or an alcohol, and the dissolution time is 15 to 60 seconds. [18] The process according to any one of claims 3, 6, 9 and 13, wherein the opaque metal used in the step (A-IO'), (B- 15') or (C- 16') is selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), silver (Ag), gold (Au) and copper (Cu). [19] The process according to any one of claims 3, 6, 9 and 13, wherein the thickness of theopaque metal layer in the step (A-IO'), (B- 15') or (C- 16') is 0.1 to 2 D. [20] The process according to any one of claims 1, 4, 7 and 11, further comprising the step of:

(A- 12) shielding the portion of no pattern image manifestation in the pattern form with a shadow mask, after the step (A-7) and before the step (A-8), after the step (B- 12) and before the step (B-13), or after the (C-13) and before the step (C- 14); and further comprising the step of:

(A- 13) applying a first color coating material by printing on the part of the refractive/reflective layer in the pattern form, and curing the first color coating material, after the step (A-8) and before the step (A-9), after the step (B-13) and before the step (B-14), or after the step (C- 14) and before the step (C-15). [21] The process according to any one of claims 1, 4,7 and 11, further comprising the step of:

(A- 14) printing patterns using a second color coating material on the pattern form, and curing the second color coating material, after the step (A-7) and before the step (A-8), after the step (B- 12) and before the step (B-13), and after the step (C-13) and before the step (C- 14). [22] The process according to claim 21, wherein the second color coating material has a refractive index which differs in value by 0.3 or less from that of the UV- curable resin for pattern form.

[23] The process according to any one of claims 1, 4, 7 and 11, further comprising the steps of:

(A- 15) applying a first color coating material by printing on a part of the pattern form, and curing the first color coating material; and (A- 16) removing any unprinted part of the refractive/reflective layer on the pattern form using an etching solution, after the step (A- 8) and before the step (A-9), after the step (B- 13) and before the step (B-14), or after thestep (C- 14) and before the step (C-15).

[24] The process according to any one of claims 1 to 14, wherein the refractive/ reflective layer is formed of a material having a refractive index which is greater in value by 0.3 or more, compared with that of the UV-curable resin for pattern form.

[25] The process according to claim 24, wherein the material having a refractive index which is greater in value by 0.3 or more compared with that of the UV- curable resin for pattern form, isselected from the group consisting of titanium(IV) oxide (TiO ), zinc(II) oxide (ZnO), cerium(IV) oxide (CeO ), zirconium(IV) oxide (ZrO ), zinc(II) sulfide (ZnS), cadmium(II) sulfide (CdS), zinc(II) selenide (ZnSe), lanthanum sesquioxide (La O ), indium tin oxide (In O DSnO), and diamond.

[26] The process according to any one of claims 1 to 14, wherein the refractive/ reflective layer isformed of a material selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt) and rhodium (Rh).

[27] The process according to any one of claims 1 to 14, wherein the thickness of the refractive/reflective layer is 100 to 12,000 A.

[28] A patterned decorative material produced by the process according to any one of claims 1 to 14.