JPH09201825A - Method of molding automobile member, and method of manufacturing automobile exterior component and automobile pillar - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To use a fiber reinforced thermoplastic resin for specularity, appearance,
Provided is a method for molding an automobile member having excellent strength and heat resistance. SOLUTION: The method for producing a thermoplastic resin automobile member is as follows: (a) Molds 10 and 20 provided with a cavity 40 for molding an automobile member, and (b) an inside of the mold. A nest 30 made of glass or ceramic having a thickness of 0.5 mm to 10 mm, and (c) a holding plate 32 that is placed inside the mold and holds down the end of the nest 30. Clearance (C) between 30 and holding plate 32 is 0.001 mm to 0.03 m
m and the restraining plate 32 for the nest 30
The cavity 40 is filled with the fiber-reinforced thermoplastic resin by using a mold assembly having a suppression margin (ΔS) of 0.1 mm or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding an automobile member made of a fiber reinforced thermoplastic resin, and an automobile exterior component and an automobile pillar manufacturing method.

[0002]

2. Description of the Related Art A mold for molding a molded product based on a thermoplastic resin (hereinafter simply referred to as a mold) is usually a thermoplastic resin melted in a cavity which is a hollow portion provided in the mold. It is made of a metal material such as carbon steel, stainless steel, aluminum alloy, or copper alloy, which is not deformed even by high pressure at the time of filling (hereinafter sometimes simply referred to as molten resin). Then, by filling the molten resin into the cavity provided in the mold, a surface having a desired shape and forming the mold cavity (hereinafter, referred to as a mold cavity surface for convenience) is transferred. To obtain a molded product.

Exterior parts for automobiles are required to have high resistance to breakage during collision, high resistance to deformation due to temperature change, and excellent appearance characteristics. Therefore, high elastic modulus, low linear expansion, high heat resistance, and high image clarity are also required for the materials constituting the exterior parts for automobiles. Examples of required values for automobile exterior parts include, for example, flexural modulus (AST
MD790) 4.0 GPa or more, linear expansion coefficient (AST
M D696) 3.0 × 10 ⁻⁵ / deg or less, load deflection temperature (ASTM D648 load 455 kPa) 140
And the image clarity (specularity) of 85% or more. Conventionally, metallic materials have been used as materials for manufacturing automobile exterior parts that satisfy these conditions. Usually, an automobile exterior component is manufactured by press-forming a metal material into a desired shape and then applying a coating. The automobile exterior parts made of a metal material satisfy various performances required, but have a drawback of being heavy in weight. In the following description, the bending elastic modulus, the linear expansion coefficient, and the load deflection temperature are measured by ASTM.
D790, ASTM D696 and ASTM D64
8 Compliant with a load of 455 kPa.

Further, since automobile exterior parts made of a metal material are usually manufactured by a press molding method, there is a problem that the degree of freedom in design is low. Therefore,
In order to reduce the fuel consumption of automobiles, reduce their weight, and diversify their designs, the production of exterior parts for automobiles from thermoplastic resins is being studied. Usually, after molding a thermoplastic resin to obtain an automobile member, a coating treatment is applied to the surface of the automobile member to produce an automobile exterior component.

Automotive pillars such as front pillars, center pillars, or rear pillars are exterior members that form a part of a side body, and are required to have excellent appearance characteristics. Therefore, generally, a pillar for automobile is formed by using a thermoplastic resin containing no filler as a raw material resin. In addition, automobile pillars are required to have high strength (particularly flexural modulus). Therefore, in general, a special shape is designed or the thickness of the automobile pillar is increased to cope with the problem. Furthermore, heat resistance is required for automobile pillars as well, and engineering plastics are usually used as raw material resins. Then, an automobile pillar is produced by molding a thermoplastic resin to obtain an automobile member for producing an automobile pillar, and then subjecting the surface of the automobile member to a hard coat treatment.

[0006]

As described above, in order to obtain various characteristics required for automobile members, it is preferable to use a thermoplastic resin containing an inorganic fiber. However, when an automobile member is molded using a thermoplastic resin containing inorganic fibers, the inorganic fibers are deposited on the surface of the automobile member, resulting in a poor appearance of the automobile member, or an image clarity (mirror surface). The problem of deterioration of the character) occurs. The phenomenon of precipitation of inorganic fibers on the surface of the automobile member can be recognized by the fact that the inorganic fibers are raised on the surface of the automobile member.

In order to solve the problem of the precipitation of inorganic fibers on the surface of a molded product, at present, the viscosity of the thermoplastic resin is reduced and the fluidity of the molten resin is improved. However, when the content of the inorganic fibers is increased, it is difficult to prevent the inorganic fibers from depositing on the surface of the molded article. Therefore, it is difficult to use a thermoplastic resin containing an inorganic fiber for an automobile member that requires excellent appearance characteristics, despite having excellent performance.

The cause of the precipitation of the inorganic fibers from the surface of the automobile member when the content of the inorganic fibers increases is related to the material of the mold. As described above, the mold is usually made of a metal material having good thermal conductivity. Therefore, the molten resin containing the inorganic fibers filled in the cavity immediately begins to be cooled when it contacts the cavity surface of the mold. As a result, a solidified layer is formed on the molten resin that is in contact with the cavity surface of the mold, and the inorganic fibers are deposited. In addition, there arises a problem that the transferability of the cavity surface of the mold to the vehicle member surface is insufficient.

In order to solve the problems described above, in general, a molten thermoplastic resin is injected into the cavity at high pressure to force the cavity surface of the mold to
A method of transferring it to the surface of a molded article or a method of delaying the development of a solidified layer in a molten thermoplastic resin by raising the mold temperature to high temperature has been adopted. However, the former method leads to an increase in the size of the molding apparatus, an increase in the size of the mold itself, and an increase in the thickness, and the high pressure filling of the molten resin causes stress to remain inside the molded product. There arises a problem that the quality of the product deteriorates. In the latter method, since the mold temperature is set close to the load deflection temperature of the resin used for molding, the cooling time of the resin in the cavity becomes long. As a result, there is a problem that the molding cycle becomes long and the productivity is lowered. Moreover, even if these molding methods are used, it is difficult to completely prevent the inorganic fibers from being deposited on the surface of the molded product. Moreover, for example, in a mold made of carbon steel,
Even if such a method is used, it cannot be said that the transferability of the cavity surface of the mold is improved or the occurrence of weld lines is sufficiently suppressed.

By using a non-reinforced thermoplastic resin containing no inorganic fiber, that is, by delaying the development of the solidified layer of the resin filled in the cavity, molding defects such as weld marks and flow marks are prevented. For the purpose of prevention, a technique of providing or attaching a low heat conductive material to the cavity surface of the mold is disclosed in, for example, JP-A-55-558.
39, JP 61-100425, JP 62-208919, JP 5-111937, JP 5-200789, JP-B 6-35.
It is proposed in Japanese Patent Laid-Open No. 134 and Japanese Patent Laid-Open No. 6-218769.

However, in the case where a mold having a low thermal conductivity is simply attached to the cavity surface of the mold by using, for example, an adhesive, the following problems occur and it is difficult to put it into practical use. (1) When the clearance between the mold and the insert having low thermal conductivity is small, if the temperature rise and decrease of the mold are repeated, the linear expansion coefficient of the material forming the mold and the material forming the insert is reduced. The nest is damaged due to the difference. (2) When the clearance between the mold and the insert having low thermal conductivity is large, when molding is performed for a long period of time, the molten resin penetrates between the mold and the insert, and burrs are generated in the molded product. Then, this burr causes a problem that the insert is damaged at the time of mold release.

Further, since fine crazes generated during cutting remain on the outer peripheral portion of the insert having low thermal conductivity,
The contact with the molten resin at high temperature and high pressure causes cracks in the outer peripheral portion of the insert, causing a problem of damage to the insert. Therefore, the durability of the mold as a whole becomes a problem, and mass production of molded products becomes difficult.

When it is attempted to delay the development of the solidified layer by using a heat-resistant plastic insert, such insert has a low rigidity and further has a poor surface hardness. There is a problem that the nest is scratched. Alternatively, there is a nest formed by forming a thin film of ceramic or the like on a metal surface by vapor deposition or the like, but there is a problem that the durability of the thin film is poor and the thin film is separated from the metal surface. Therefore, such a nest is used only for a test mold and a simple mold, and cannot endure long-term use. Further, when a molded product is molded from a thermoplastic resin containing inorganic fibers using a mold in which these nests are incorporated, since the fluidity of the molten resin is poor, a high stress is applied to the nests. as a result,
The shortening of the life of the nest is unavoidable. Furthermore, since the inorganic fibers come into contact with the nest, it is necessary to impart wear resistance to the surface of the nest. For the above reasons, it is extremely difficult to mold a molded product based on a thermoplastic resin containing inorganic fibers by using a mold incorporating these nests.

As another method for delaying the development of the solidified layer,
It is also known that the mold temperature is raised to a high temperature before filling the molten resin into the cavity by using high frequency, electricity, steam, etc., and the mold temperature is lowered to a low temperature by using water etc. in the cooling step. . However, this method requires a large amount of equipment, causes high cost, and has many problems such as a long molding cycle. At present, it has not been practically used.

Therefore, the object of the present invention is to faithfully transfer the state of the mold surface of the cavity to the surface of the member for automobiles even if the fiber reinforced thermoplastic resin is used, and the specularity, appearance, strength and heat resistance are obtained. It is possible to manufacture automobile parts with excellent properties, the maintenance of the inserts is easy, and the inserts made of low thermal conductive material such as ceramics and glass do not break during molding, and there is no burr on the automotive parts. An object of the present invention is to provide a method for molding a member for an automobile, in which the occurrence of the phenomenon does not occur. Further, it is an object of the present invention to provide a method for manufacturing an automobile exterior component or an automobile pillar based on such an automobile member.

[0016]

In order to achieve the above object, a method for producing an automobile member made of a thermoplastic resin of the present invention is (a) for forming an automobile member provided with a cavity. A mold, and (b) placed inside the mold,
0.5 mm to 1 in thickness, forming part of the cavity
0 mm glass or ceramic insert, and (c)
A presser plate disposed inside the mold and forming a part of the cavity, which holds down the end of the insert,
The clearance (C) between the insert and the restraining plate is 0.001 mm to 0.03 mm (0.001 mm ≦ C
.Ltoreq.0.03 mm), and the pressing margin (.DELTA.S) of the pressing plate against the insert is 0.1 mm or more (.DELTA.S.gtoreq.0.
1 mm) is used to fill the cavity with a fiber reinforced thermoplastic resin to mold a thermoplastic resin automobile member.

If the thickness of the insert is less than 0.5 mm, the heat insulation effect of the insert is reduced, and the molten resin introduced into the cavity is rapidly cooled. Inorganic fibers are deposited on the surface. Further, the probability of appearance defects such as weld marks and flow marks is increased. Further, the transferability of the cavity surface of the nest to the surface of the automobile member is deteriorated, and the specularity of the surface of the automobile member is deteriorated. Further, when fixing the insert to the mold, for example, a thermosetting adhesive may be used to adhere the insert to the mold, but the insert has a thickness of 0.5.
If the thickness is less than mm, uneven stress remains in the insert when the adhesive film thickness becomes uneven, causing a phenomenon that the surface of the automobile member is wavy, or the insert is damaged by the pressure of the filled molten resin. Sometimes. On the other hand, if the thickness of the insert exceeds 10 mm, the heat insulation effect of the insert becomes too great, and the automobile member may be deformed after taking out the automobile member from the mold unless the resin cooling time in the cavity is extended. There is. Therefore, problems such as extension of the molding cycle may occur. Incidentally, by using such a nest, it is possible to mold the automobile member at a constant mold temperature, and no special equipment is required.
The molding cycle is also the same as normal molding. The thickness of the insert is preferably 1 mm to 7 mm, more preferably 2 mm to 5 mm.

In the method for molding an automobile member according to the present invention, the clearance (C) between the insert and the restraining plate is
Is 0.001 mm or more and 0.03 mm or less (0.001 mm
mm ≦ C ≦ 0.03 mm), more preferably 0.003
mm to 0.03 mm (0.003 mm ≦ C ≦ 0.03
mm). Here, the clearance (C) is
It is the gap between the insert and the restraining plate, measured along the thickness direction of the insert (direction perpendicular to the cavity surface of the insert). The more specific minimum value of clearance (C) is
When attaching the restraint plate, minute cracks are generated in the outer periphery of the insert, or when the insert heats up due to thermal expansion of the insert, the insert and the suppressor plate come into contact with each other, and stress is applied to the fine cracks in the outer periphery of the insert. As a result of the addition, there is a problem that the insert is broken, and the insert may be damaged by the impact at the time of mold clamping. On the other hand, if the clearance (C) exceeds 0.03 mm, the molten resin may invade between the insert and the restraining plate, cracking may occur in the insert, and burrs may occur on the automobile member. .

When the pressing margin (ΔS) is less than 0.1 mm,
As a result of contacting the craze generated at the end of the nest with the molten resin at the time of making the nest, the craze grows into cracks,
The nest may be damaged. The upper limit of the suppression margin (ΔS) is not particularly specified, but it is preferably about 2 mm. Here, the pressing margin (ΔS) is the distance from the end surface (side surface) of the pressing plate to the end portion (side surface) of the pressing plate, measured along a direction parallel to the cavity surface of the nest.

The clearance (D) between the insert mounting portion provided in the mold and the insert may be as close as possible to 0, but in practice, it is preferably 0.005 mm or more. Here, the clearance (D) refers to a clearance between the insert mounting portion of the mold and the end surface (side surface) of the mold, measured along a direction parallel to the cavity surface of the insert. Depending on the linear expansion coefficient of the material forming the insert, if the clearance (D) is too small, damage to the insert due to the difference in linear expansion coefficient between the material forming the insert mounting portion of the mold and the material forming the insert. It may not be possible to prevent it. Therefore, the clearance (D) is
The value may be set so that such a problem does not occur. still,
If the clearance (D) is made too large, there is a risk that the nest will be damaged because the nest is displaced and the stability of the nest is insufficient. Therefore, the clearance (D) is preferably about 2 mm or less.

Usually, the mold is composed of a fixed mold part and a movable mold part. Depending on the shape of the automobile member to be molded, the required surface characteristics, etc., the nest may be arranged only in the movable mold part or in the fixed mold part. Alternatively, they may be arranged on both the movable mold part and the fixed mold part. The part of the mold on which the nest is mounted may be composed of a core mounted on the mold. In addition, it is preferable that the insert is disposed in the mold so as to face a surface portion of the automobile member for which excellent smoothness (specularity) is required.

Incidentally, to form a part of the cavity means to form a cavity surface which defines the outer shape of the automobile member. More specifically, the cavity includes, for example, a surface forming a cavity formed in the movable mold portion and the fixed mold portion, a surface forming a cavity formed in the nest, and a cavity formed in the holding plate. And the surface forming the. The surfaces forming these cavities are hereinafter referred to as cavity surfaces.

The fiber-reinforced thermoplastic resin preferably contains inorganic fibers. Inorganic fiber content is 15
% To 80% by weight, preferably 20 to 60% by weight
% By weight. Generally, the proportion of the inorganic fibers contained in the thermoplastic resin (in other words, the proportion of the inorganic fibers added to the thermoplastic resin) was measured in accordance with the required flexural modulus (for example, ASTM D790). Value is 4.0 GPa or more), linear expansion coefficient, load deflection temperature, etc., as long as it is within a range in which a member for automobiles can be molded, the upper limit of which is the fluidity of the molten resin in the cavity decreases. Therefore, the value may be set to a value at which molding becomes difficult, or it becomes impossible to mold an automobile member having excellent specularity. Specifically, the upper limit is 80% by weight. When the crystalline thermoplastic resin is used, the amount is 80% by weight, but when the amorphous thermoplastic resin is used, the fluidity is inferior to that of the crystalline thermoplastic resin. Is 50% by weight. Content rate is 15
If it is less than 10% by weight, the required flexural modulus cannot be obtained, and if it exceeds 80% by weight, the flowability of the molten resin is lowered, which makes molding difficult, or a member for automobiles having excellent specularity is obtained. There is a risk that molding will not be possible.

The average length of the inorganic fibers is 5 μm to 400
μm, preferably 5 μm to 200 μm, the average diameter is
0.01 μm to 15 μm, preferably 0.00.5 μm
To 15 μm, more preferably 0.1 to 10 μm
It is desirable that If the average length of the inorganic fibers is less than 5 μm and the average diameter is less than 0.01 μm, the flexural modulus required for automobile members cannot be obtained. On the other hand, when the average length of the inorganic fibers exceeds 400 μm or the average diameter exceeds 15 μm, there arises a problem that the surface of the automobile member does not become a mirror surface.

The average length of the inorganic fibers in the present invention means the weight average length. The length of the inorganic fiber is measured by immersing the thermoplastic resin pellet containing the inorganic fiber or the automobile member in a liquid that dissolves the resin component of the thermoplastic resin to dissolve the resin component, or in the case of glass fiber, 600 The residual inorganic fibers can be measured by observing the residual inorganic fibers with a microscope or the like by burning the resin component at a high temperature of ° C or higher. Usually, the length of the inorganic fiber is determined by taking a photograph of the inorganic fiber and measuring the length by a person or using a dedicated fiber length measuring device. It is preferable to use the weight average length because the number average length has a too large influence of the finely broken fibers. When measuring the weight average length, the fragments of inorganic fibers that are too small and crushed are removed. When the length of the inorganic fiber is less than twice the nominal diameter, the measurement becomes difficult. Therefore, for example, an inorganic fiber having a length of twice the nominal diameter or more is used as the measurement target.

The inorganic fibers having an average length and an average diameter within the above ranges are surface-treated with a silane coupling agent or the like, then compounded with a thermoplastic resin and pelletized to obtain a molding material. . By molding an automobile member using such a molding material and a mold assembly incorporating a nesting member and a restraining plate, an automobile member having high rigidity and excellent mirror surface property is obtained. You can

The inorganic fibers are glass fibers, carbon fibers,
It is preferably composed of at least one material selected from the group consisting of wollastonite, aluminum borate whisker fibers, potassium titanate whisker fibers, basic magnesium sulfate whisker fibers, calcium silicate whisker fibers and calcium sulfate whisker fibers. . The inorganic fiber contained in the thermoplastic resin is not limited to one kind, and two or more kinds of inorganic fibers may be contained in the thermoplastic resin.

The thermal conductivity of the nest is 2 × 10 ^-2 cal /
It is preferably cm / sec / deg or less. Nesting is wide, zirconia-based material, alumina-based material, K ₂
It can be made from a ceramic selected from the group consisting of O—TiO ₂ or a glass selected from the group consisting of soda glass, quartz glass, heat resistant glass and crystallized glass, and more specifically, ZrO ₂ , ZrO ₂ -Ca
_{O, ZrO 2 -Y 2 O 3} , ZrO 2 -MgO, K 2 O-Ti
_{O 2, Al 2 O 3,} Al 2 O 3 -TiC, Ti 3 N 2 and 3A
It can be made from a ceramic selected from the group consisting of 1 ₂ O ₃ -2SiO ₂ or a glass selected from the group consisting of soda glass, quartz glass, heat-resistant glass and crystallized glass, among which thermal conduction Rate is 2 × 10
^-2 cal / cm · sec · deg or less, ZrO ₂
It is preferably made of a ceramic consisting of -Y ₂ O ₃ or 3Al ₂ O ₃ -2SiO _2. 2 × 10 ^-2
When a nest is made using a material having a thermal conductivity exceeding cal / cm · sec · deg, the molten resin in the cavity is rapidly cooled by the nest, so it is made from ordinary carbon steel without a nest. In some cases, the appearance may be similar to that of an automobile member molded with the formed mold, and there is a possibility that the development of the solidified layer cannot be suppressed.

Alternatively, the nesting has a crystallinity of 10%.
As described above, it is preferable to manufacture from crystallized glass having a crystallinity of 60% or more, and more preferably 70 to 100%. When the crystallinity is 10% or more, the crystals are uniformly dispersed throughout the glass, and the thermal shock strength and the interfacial peeling property are remarkably improved, and the occurrence of damage to the nest during the molding of automobile parts is significantly reduced. be able to. If the crystallinity is less than 10%, there is a drawback that interface peeling easily occurs from the surface during molding.
The surface roughness R _max of the cavity surface of the insert is 0.03.
It is preferably μm or less and the thermal shock strength is 400 ° C. or more. Further, the linear expansion coefficient of the crystallized glass forming the nest is preferably 1 × 10 ⁻⁶ / deg or less.

The thermal shock strength is 1 when heated to a predetermined temperature.
The strength is defined as the temperature at which a glass of 00 mm × 100 mm × 3 mm is cracked when thrown into water at 25 ° C. Thermal shock strength is 4
00 ° C means 100mm × heated to 400 ° C
This means that when 100 mm × 3 mm glass is thrown into water at 25 ° C., the glass does not crack.
This thermal shock strength can be obtained only at a value of around 180 ° C. even in heat resistant glass. Therefore, when the resin melted at a higher temperature (eg, about 300 ° C.) comes into contact with the insert, the insert may be distorted and the insert may be damaged. Thermal shock strength is also related to the crystallinity of glass,
If the insert is made of crystallized glass having a crystallinity of 0% or more, it is possible to reliably prevent the insert from cracking during molding.

The term "crystallized glass" as used herein means that a small amount of a nucleating agent for TiO ₂ and ZrO ₂ is added to a raw glass to obtain a glass at 1600 ° C
After melting under the above high temperature, press, blow, roll,
Molded by a casting method or the like, and further heat-treated for crystallization to grow Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals in the glass, and the main crystal phase is β-eucryptite-based crystals and β-eucryptite-based crystals. -The thing which the spodumene system crystal | crystallization was produced can be illustrated. Alternatively, CaO-Al ₂ O ₃ -Si
After melting the O ₂ glass at 1400 to 1500 ° C, transfer it to water and crush it to make it into small particles, then accumulate and shape it into a plate on a refractory setter, then heat it to make it It is possible to exemplify that the rustonite crystal phase is generated. _{Furthermore, SiO 2 -B 2 O 3 -Al} 2 O 3 -MgO-
Examples of heat-treated K ₂ O-F type glass to generate mica crystals, and heat-treated MgO-Al ₂ O ₃ -SiO ₂ type glass containing a nucleating agent to generate cordierite crystals can do. In addition, it is preferable to use crystallized glass having β-eucryptite-based crystals or β-spodumene-based crystals excellent in strength and thermal characteristics as the nest in the present invention.

In these crystallized glasses, the ratio of crystal particles present in the glass substrate can be expressed by the index of crystallinity. Then, the crystallinity can be measured by measuring the ratio of the amorphous phase and the crystalline phase using an analytical instrument such as an X-ray diffractometer.

In the case where the nest is made of ceramic, at least one thin film layer made of the above-mentioned material forming the nest may be provided on the surface of the nest by a surface treatment technique such as ion plating. The holes can be filled, and the surface characteristics of the automobile member can be further improved.

When the insert is made of ceramic, the protruding material may be transferred to the surface of the automobile member because the material of the insert is porous. However, the crystallized glass has the advantages that the crystal particles are fine, the adhesive force between the particles is excellent, and that the surface of the automobile member is likely to be a mirror surface because it is not porous.

When the nest is made of amorphous glass such as soda glass, heat-resistant glass, and quartz glass, a thermoplastic resin (for example, polyamide 6 resin, polyamide 66 resin, etc.) having excellent affinity and adhesiveness with these materials is used. Polyamide MX
Polyamide resin such as D6 resin, PBT resin and PET
When molding is performed using (polyester resin such as resin), the nest and the resin are firmly adhered to each other, and when the mold of the automobile member is released from the mold, the nest causes interface peeling from the surface. There is. In such a case, the nest may be made of crystallized glass. Since crystallized glass has a high strength between crystal grains, interfacial peeling does not occur from its surface, and there is no problem that the insert is broken even if molding is performed for a long time.

When a mirror surface property is required for automobile parts,
The surface roughness R _max of the cavity surface of the nest is 0.03 μm
It is desirable to make the following. Surface roughness R _max is 0.03
If it exceeds μm, the specularity may be insufficient, and the characteristics required for automobile members, such as surface smoothness (image clarity), may not be satisfied. For that purpose, for example, diamond lapping is performed on the cavity surface of the produced nest until the surface roughness R _max becomes 0.03 μm or less, and further, if necessary, lapping with cerium oxide. . Lapping can be performed using a lapping machine or the like. Compared with the usual polishing of carbon steel or the like, for example, in the case of crystallized glass, a mirror surface can be obtained at a cost of about 1/2, so that the manufacturing cost of the mold assembly can be reduced. The surface roughness R _max is measured by JI
According to S B0601. When molding an automobile member having a matte or heller-lined surface, the cavity surface of the nest may be subjected to sandblasting or etching to form fine irregularities or lines on the cavity surface of the nest.

The nest has a linear expansion coefficient of 12 × 10.
It is preferably made of ceramic or glass of ^-6 / deg or less. Here, the linear expansion coefficient is an average value from 50 ° C to 300 ° C. As a result, it is possible to effectively prevent the deformation and damage of the insert due to the expansion and contraction of different materials such as the mold and insert. For example, in the case of molding automobile parts by mounting a mold on a mold made of carbon steel (in some cases, a core), heat of the molten resin and heat of water, oil, etc. of the mold temperature controller cause the mold and The nests expand together. Therefore, if the linear expansion coefficient exceeds the above value, unless the clearance (D) between the insert mounting portion provided in the mold and the insert is considerably increased, the insert is damaged due to the difference in linear expansion coefficient. There are cases. When the insert is made of crystallized glass, the coefficient of linear expansion can be set to 1 × 10 ⁻⁶ / deg or less.

In the molding method of the present invention, it is possible to easily process irregularities, curved surfaces, etc. of the material forming the nest by ordinary grinding, and it is possible to manufacture a nest of any shape other than a considerably complicated shape. . A nest can be produced by putting ceramic powder or molten glass in a molding die, press-molding it, and then heat-treating it. Further, the nesting can be made by naturally shaping the glass plate-like object on the jig in the furnace. The lapping process can be easily performed in the final step.

In the case of molding an automobile member having a curved surface, the insert portion of the mold is processed according to the curvature of the back surface of the insert (the surface opposite to the cavity surface of the insert and facing the mold). Also, the pressing plate may be ground according to the curvature of the cavity surface of the insert. If such processing is not performed, the insert may be deformed and damaged due to the pressure of the molten resin filled in the cavity.
Also in this case, ΔS ≧ 0.1 mm and 0.001 m
While maintaining the relationship of m ≦ C ≦ 0.03 mm, the insert is attached to the insert attachment portion of the mold, and the insert is suppressed and the plate is suppressed.

After processing into a predetermined shape by grinding or the like, when there is no risk that the insert will fall from the insert mounting portion provided inside the mold when the insert is attached, or without using an adhesive. When the nest can be mounted on the nest mounting portion, the nest can be directly mounted on the nest mounting portion provided inside the mold without using an adhesive. Alternatively, the insert may be adhered to the insert mounting portion using a thermosetting adhesive selected from epoxy, urethane, acrylic, silicone and the like. However, it is desirable to make the thickness of the adhesive as thin and uniform as possible in order to prevent the nest from being distorted due to the uneven thickness of the adhesive.

Further, when the insert made by heat bending of glass is attached to the mold, the end face of the insert is not necessarily parallel to the side wall of the insert attaching part of the mold, but the insert of the insert and the insert of the mold is attached. If the clearance (D) between the insert and the part is within a range of 2 mm or less, the insert may be attached to the mold while paying attention to the occurrence of damage to the end of the insert. It is also conceivable to grind the end surface of the insert made of glass after heat bending to make it parallel to the side wall of the insert mounting part of the mold, but because the insert has a sharply processed edge portion, There is a possibility that the insert will be damaged when it is attached to the mold. Therefore, it is desirable to cut the side wall of the insert mounting portion of the mold so as to be parallel to the end face of the insert.

As the thermoplastic resin suitable for use in the present invention, polyolefin resin such as polyethylene resin and polypropylene resin; polystyrene resin, AS resin, A
Styrene resin such as BS resin and AES resin; methacrylic resin; polycarbonate resin; polyoxymethylene (polyacetal) resin; polyamide 6, polyamide 6
6, polyamide-based resins such as polyamide MXD6; modified polyphenylene ether (PPE) resins; polyester-based resins such as polyethylene terephthalate (PET) resins and polybutylene ethylene terephthalate (PBT) resins;
Polyphenylene sulfide resin; a thermoplastic resin such as a liquid crystal polymer, or a polymer alloy resin composition composed of at least two kinds of these thermoplastic resins can be mentioned. Among them, a polyamide resin, a polycarbonate resin, a modified resin Polyphenylene ether resin, polyester resin, and polycarbonate resin /
It is preferable to use a thermoplastic resin selected from the group consisting of polyester resin polymer alloy resin compositions. Thermoplastic resins include stabilizers, UV absorbers,
Release agents, dyes and pigments, etc. may be added, and in some cases, inorganic fillers such as mica, kaolin and calcium carbonate, or organic fillers may be added.

There is no particular limitation on the automobile member formed by the automobile member forming method of the present invention.
Examples thereof include automobile parts for producing automobile exterior parts and automobile pillars.

The method for manufacturing an automobile exterior component of the present invention is as follows:
The invention is characterized in that a coating film is formed on at least a part of the surface of an automobile member molded by the automobile member molding method of the present invention described above. In this case, the coating film is preferably at least one coating film selected from the group consisting of an acrylic coating film, a urethane coating film and an epoxy coating film. That is, after removing dust or the like from the surface of the automobile member, the paint is applied to the surface of the automobile member by a method such as brush coating, spraying, electrostatic coating, or dipping, and then dried to obtain an automobile member. A coating can be formed on at least a portion of the surface of the member. In addition, it is preferable to use a coating material having a curing temperature equal to or lower than the deflection temperature of the raw material thermoplastic resin under load. Since the residual strain in the automobile member is small, cracks are unlikely to occur in the automobile member due to the coating solution. Examples of exterior parts for automobiles include front fenders, rear fenders, doors, bonnets, roofs or trunk fades. Table 1 below shows the physical property values required for automobile parts for producing automobile exterior parts, or the physical property values required for automobile exterior parts.

[0045]

[Table 1] Flexural modulus: 4.0 GPa or more Linear expansion coefficient: 4.0 × 10 ^-5 / deg or less Deflection temperature under load: 100 ° C or more Image clarity: 85% or more (for automobile parts)

In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing inorganic fibers satisfying the specifications shown in Table 2 below. Further, it is desirable that the physical property values of the thermoplastic resin containing the inorganic fiber are as shown in Table 3 below.

[0047]

[Table 2] Average length: 5 to 400 μm, more preferably 5
~ 200 μm Average diameter: 0.01 to 15 μm, preferably 0.05 to
13 μm, more preferably 0.1 to 10 μm Content: 15 to 80% by weight, preferably 20 to 60
weight%

[0048]

[Table 3] Flexural modulus: 4.0 GPa or more, more preferably 4.5 GPa or more Linear expansion coefficient: 4.0 x 10 ^-5 / deg or less, more preferably 3.5 x 10 ^-5 / deg or less Deflection temperature under load: 100 ° C or higher, preferably 110 ° C or higher

The method for producing an automobile pillar of the present invention further comprises the step of forming a hard coat layer on at least a part of the surface of the automobile member molded by the above-described automobile member molding method of the present invention. It is characterized by including.
In this case, the hard coat layer is at least one selected from the group consisting of an acrylic hard coat layer, a urethane hard coat layer and a silicone hard coat layer.
Preferably, it comprises a hard coat layer of the seed. That is, after removing dust and the like from the surface of the molded automobile member, a solution selected from acrylic, urethane or silicone hard coat solutions is applied to the surface of the automobile member by a dip method, a flow coating method, The hard coat layer can be formed on at least a part of the surface of the automobile member by applying by a method such as a spray method and then drying and curing. The thickness of the hard coat layer on the surface of the automobile member is 1 μm to 30 μm, preferably 3 μm to 15 μm. If it is less than 1 μm, the durability of the hard coat layer is insufficient, and if it exceeds 30 μm, cracks are likely to occur in the hard coat layer. When the adhesion between the hard coat layer and the automobile member is not sufficient, the adhesion can be improved by applying the primer coat to the automobile member and then applying the top coat. Since the residual strain in the automobile member is small, the occurrence of cracks in the automobile member due to the formation of the hard coat layer is unlikely to occur. Examples of automobile pillars include automobile pillars such as front pillars, center pillars, and rear pillars. Table 4 below shows the physical property values required for automobile members (sometimes referred to as pillar members) for producing automobile pillars or the automobile pillars.

[0050]

[Table 4] Flexural modulus: 4.0 GPa or more Linear expansion coefficient: 4.0 × 10 ^-5 / deg or less Deflection temperature under load: 100 ° C or more Image clarity: 80% or more (for automobile parts)

In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber satisfying the specifications shown in Table 5 below. The physical properties required for the thermoplastic resin containing inorganic fibers are shown in Table 6 below.

[0052]

[Table 5] Average length: 5 to 400 µm, more preferably 5
~ 200 μm Average diameter: 0.01 to 15 μm, preferably 0.05 to
13 μm, more preferably 0.1 to 10 μm Content: 15 to 80% by weight, preferably 20 to 60
weight%

[0053]

[Table 6] Flexural modulus: 4.0 GPa or more Linear expansion coefficient: 4.0 x 10 ^-5 / deg or less Load deflection temperature: 100 ° C or more

In the method of molding a member for automobiles of the present invention, the injection molding method, blow molding method and multicolor molding method which are generally used for molding a thermoplastic resin can be mentioned, but the most preferable method. Is an injection molding method.

In general, in order to prevent the warp of the automobile member due to the shrinkage of the resin after molding, it is necessary to consider the thermal conductivity and thickness of the fixed mold part, the movable mold part and the nest, It is desirable to eliminate as much as possible the temperature difference between the fixed mold part and the movable mold part when the automobile member is taken out.

In the method for molding an automobile member of the present invention, since the mold assembly provided with the insert and the restraining plate is used, it is possible to reduce the rapid cooling of the molten resin injected or introduced into the cavity. Therefore, it is possible to reliably and easily form an automobile member having excellent specularity even at a low mold temperature. Moreover, as a result of the solidification of the molten resin being delayed, the fluidity of the resin is improved, so that even if the fiber content in the fiber-reinforced thermoplastic resin is high, it is possible to mold the automobile member, and the surface of the automobile member can be formed. It is possible to prevent the fibers from precipitating. Further, since the fluidity of the molten resin is improved, the injection pressure of the molten resin can be set low and the stress remaining in the automobile member can be relaxed. As a result, the quality of automobile parts is improved. Also,
Since the injection pressure of the molten resin can be reduced, the mold can be made thinner, the molding apparatus can be downsized, and the manufacturing cost of the automobile member can be reduced. In addition, it is possible to achieve a reduction in the thickness of automobile parts, which has been considered impossible with a thermoplastic resin containing fibers.

Particularly, when using plastics such as engineering plastics and super engineering plastics which have excellent heat resistance and strength but have poor moldability, molding is usually carried out at a mold temperature of 100 ° C. or higher. A lot of appearance defects occur.
However, since the heat insulating effect is obtained by using the mold assembly according to the present invention, it is possible to obtain an automobile member having good appearance characteristics even when the mold temperature is 100 ° C. or lower. Even if the thermoplastic resin containing the inorganic fiber is used, the phenomenon that the inorganic fiber is not deposited on the surface of the automobile member does not occur, and the automobile member having excellent appearance characteristics such as specularity can be obtained. This is for cooling the injected molten resin
As a result of being able to delay solidification by nesting,
This is because the fluidity and transferability of the molten resin can be improved.

If the insert is made of a material having a low coefficient of thermal expansion, the insert is made independently of the mold,
Since it is arranged inside the mold, not only the heat insulation effect of the nest is great, but also the maintenance of the nest is easy. If the insert is made of crystallized glass, it is possible to make the insert having a low linear expansion coefficient, strong against thermal shock, and less likely to be damaged or cracked. By using such a nest, the heat insulation effect by the nest is large, quenching of the molten resin in the cavity can be suppressed, and it is possible to effectively prevent appearance defects such as weld marks and flow marks from occurring. . Moreover, by restraining the nesting by the restraining plate within the predetermined clearance (C) and the restraining margin (ΔS), the appearance of the end of the automobile member is not impaired, and the end of the automobile member is not burred. And the molten resin does not come into contact with the fine craze remaining on the outer peripheral portion of the insert, so that damage to the insert can be prevented.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on preferred embodiments. The image clarity of the automobile members molded in the Examples and Comparative Examples was measured under the conditions shown in Table 7 below using a surface image clarity measuring instrument (ICP-2DP manufactured by Suga Test Instruments Co., Ltd.). As the measurement site, a site having a large curvature was selected, and the automobile member was cut and measured. In addition, at the time of measurement, a 3 kg sample holder was used, and the measurement site was made as close to the plane as possible. 10 points were measured and the average value was calculated. Furthermore, regarding the physical properties of automobile members, the linear expansion coefficient is based on ASTM D696, and the load deflection temperature is ASTM D648 load 455k.
It was measured based on Pa.

[0060]

[Table 7] Measurement range: 20 mm diameter Incident and acceptance angles: 60 degrees Optical comb width: 0.5 mm

(Example 1) Examples 1 and 2 described below relate to a method for molding an automobile member and a method for manufacturing an automobile exterior component. A specific example of a mold assembly suitable for carrying out the method for molding an automobile member in Example 1 is shown in a schematic partial end view in FIG. Also,
A schematic end view of the mold assembly during assembly is shown in FIGS. 1B and 1C. The mold assembly is assembled in the order of FIG. 1 (B), FIG. 1 (C), and FIG. 1 (A).

In Example 1, a nest 30 was made using crystallized glass (crystallinity 70%) having the characteristic values shown in Table 8 below. The shape of the nest 30 is 4.00 m thick
m, the length is 471.00 mm and the width is 451.00 mm.

[0063]

[Table 8] Material: Crystallized glass composed of spodumene-based crystals (manufactured by Nippon Electric Glass Co., Ltd., trade name N-0) Crystallinity: 70% Density: 2.51 g / cm ³ Thermal conductivity: 0.4 × 10 ^-2 cal / cm · sec · d
eg linear expansion coefficient: -6.0 × 10 ^-6 / deg Thermal shock temperature: 800 ° C

In the mold assembly of Example 1, the size of the cavity 40 was 470.00 mm × 450.00 mm ×.
It was 3.00 mm and the shape was a rectangular parallelepiped. Fixed mold part 1
0 was produced from carbon steel S55C. The part of the fixed mold part 10 to which the insert 30 is attached is composed of a core 12 made of carbon steel S55C, and the insert 12 is provided on the core 12. Inner dimensions of the nesting part 11 are 471.20 mm x 4
The core 12 was cut to a depth of 51.20 mm and a depth of 4.02 mm.

Two-component curing type epoxy adhesive (not shown)
Was used to fix the insert 30 in the insert mounting portion 11 of the core 12 (see FIG. 1 (B)). Then nest 30
The cavity surface 31 of No. 30 is ground and finished using a diamond grindstone and a cerium oxide grindstone, and the surface roughness R _max of the cavity surface 31 of the insert 30 is 0.02.
μm. When the clearance (D) between the insert 30 and the insert mounting part 11 was measured using a gap gauge, the minimum clearance was 0.05 mm. Next, the core 12 was attached to the fixed mold part 10.

The restraining plate 32 was made of carbon steel S55C. The inner dimension of the restraining plate 32 is 470.00 m
It was set to m × 450.00 mm. The holding plate 32 was fixed to the fixed mold section 10 with screws (not shown) (see (C) of FIG. 1). Nesting 30 and retaining plate 32
The average clearance (C) between and is 0.019mm
Met. In addition, the retaining plate 32 for the nest 30
The suppression margin (ΔS) was 0.5 mm. The gate portion is not shown in FIG. 1 (C).

On the other hand, the movable mold part 20 was made of carbon steel S55C. Then, the movable mold part 20 and the fixed mold part 10 shown in FIG. 1 (C) were assembled to complete a mold assembly (see FIG. 1 (A)).

After the completed mold assembly was attached to the molding apparatus, the mold assembly was heated to 130 ° C. using a mold temperature controller and then rapidly cooled to 40 ° C. No damage such as cracking occurred in the produced nest 30.

A 550MM injection molding machine manufactured by Mitsubishi Heavy Industries, Ltd. was used as an injection molding machine, and the mold assembly was
Heated to ° C. And, 20% by weight of inorganic fibers composed of aluminum borate whisker fibers shown in Table 9 below.
Using a thermoplastic resin containing a polycarbonate resin contained therein, under the injection molding conditions shown in Table 9 below, a sufficient amount of molten resin to completely fill the inside of the cavity 40 is passed through the gate portion 13 into the cavity 40. Injected into. Then, 20 seconds after the completion of injection, the automobile member was taken out of the mold assembly.

[0070]

[Table 9] Aluminum borate whisker fibers Average length: 10 μm Average diameter: 0.1 μm Molding conditions Mold temperature: 80 ° C Resin temperature: 310 ° C Injection pressure: 500 kgf / cm ² -G

The surface of the automobile member (the surface that was in contact with the insert 13) had a mirror-like property up to the end of the mold, even though the mold temperature was low. As a result of measuring the smoothness of the surface of the member for automobiles using a surface image clarity measuring instrument, it had a very high specularity of 95% against 100% of the perfect specular surface. In addition, when the physical properties of the members for automobiles were measured,
Flexural modulus 6.0 GPa, linear expansion coefficient 2.5 × 10 ^-5 /
It was found that the temperature was deg. and the deflection temperature under load was 145.degree. Further, the molding is continuously performed for 10
After performing 000 cycles, no damage such as cracking occurred in the nest 30.

The surface of the molded automobile member was coated with a urethane-based paint by a spray method, and then the paint was cured in an oven at 140 ° C. for 2 hours. as a result,
The subject was clearly projected, and exterior parts for automobiles with excellent image clarity were obtained. Further, the molding cycle of the automobile member was about 40 seconds / piece, which was excellent in mass productivity.

(Comparative Example 1A) In Comparative Example 1A, a mold assembly was used in which the mold was made from Starbucks steel and the cavity surface of the mold was mirror-polished. The structure of the mold assembly of Comparative Example 1A is the same as that of the mold of Example 1 except that the mold and the pressing plate are not provided, as shown in the schematic partial end view of FIG. It has the same structure as the mold assembly. Then, using the same thermoplastic resin as in Example 1, molding was performed under the same molding conditions as in Example 1. As a result, the fluidity of the molten resin in the cavity was poor, and the cavity could not be completely filled with the molten resin. Therefore, the injection pressure 200 kgf / cm ² -G increased, molding was conducted as 700kgf / cm ² -G.
Inorganic fibers were deposited on the surface of the obtained automobile member, and the appearance was very poor. When the surface smoothness of the automobile member was measured by a surface image clarity measuring device, it was 7% with respect to 100% of perfect mirror surface, and the mirror surface property was remarkably lower than that of the automobile member of Example 1.

(Comparative Example 1B) In Comparative Example 1B, as shown in the schematic partial end view in FIG. 3B, a mold assembly having a structure without a restraining plate was used. Then, using the same thermoplastic resin as in Example 1, molding was performed under the same molding conditions as in Example 1. As a result, the external appearance of the end portion of the automobile member was inferior, and defective appearance such as burrs occurred. In addition, the nesting 30 in 15 cycles of molding
A crack occurred at the end of the.

Comparative Example 1C In Comparative Example 1C, Example 1
In the mold assembly used in (1), the clearance (C) between the pressing plate 32 and the insert 30 was 0.04 mm. Then, using the same thermoplastic resin as in Example 1, molding was performed under the same molding conditions as in Example 1. As a result, the molten resin intruded into the gap between the pressing plate 32 and the nest 30, and the automobile member could not be removed from the mold assembly during mold release.

Comparative Example 1D In Comparative Example 1D, Example 1
In the mold assembly used in Section 3, the pressing margin (ΔS) of the pressing plate 32 with respect to the insert 30 was set to 0.05 mm.
Then, using the same thermoplastic resin as in Example 1, molding was performed under the same molding conditions as in Example 1. as a result,
Cracks grew from the outer peripheral portion of the insert, and cracks occurred on the entire surface of the insert 30 in the fifth molding cycle.

(Example 2) In Example 2 as well, the same mold assembly as in Example 1 was used. As the thermoplastic resin, a polycarbonate resin containing 50% by weight of silane-coupling glass fiber as an inorganic fiber was used. The glass fiber had an average length of 70 μm and an average diameter of 10 μm. Molding conditions include resin temperature of 3
Same as Example 1 except that the temperature was raised to 30 ° C. Table 10 shows the results of measuring the surface smoothness and the physical properties of the automobile member before the same coating as in Example 1 by the surface image clarity measuring device. In addition, the surface of the molded automobile member,
After applying urethane-based paint by the spray method, 140
The coating was allowed to cure for 2 hours in a ° C oven. As a result, an automobile exterior component having a clear image of the subject and excellent image clarity was obtained.

(Comparative Example 2A to Comparative Example 2C) Comparative Example 2A to
In Comparative Example 2C, the same mold assembly as in Example 1 was used. As the thermoplastic resin, a polycarbonate resin containing silane coupling-treated glass fibers as inorganic fibers was used. Table 1 shows the specifications of the thermoplastic resin used.
0 is shown. Table 10 shows the measurement results of the surface smoothness and the physical properties of the automobile member obtained under the same molding conditions as in Example 2. In Table 10, the fiber length and the fiber diameter mean the average length and the average diameter of the fiber. The unit of linear expansion coefficient is 10 ⁻⁵ / deg.

[0079]

Table 10 Examples Comparative examples -2 -2A -2B -2C Fiber length (μm) 70 70 500 500 Fiber diameter (μm) 10 10 10 10 Fiber addition amount (wt%) 50 10 10 50 Flexural modulus ( GPa) 5.0 2.5 3.5 3.5 8.8 Coefficient of linear expansion 2.8 5.2 2.8 2.1 Deflection temperature under load (° C) 145 142 143 147 Image clarity (%) 87 93 93 76 52

As is clear from Comparative Examples 2B and 2C, when the average length of the inorganic fibers exceeds 400 μm, the image clarity is deteriorated. Further, as is clear from Comparative Example 2A, when the content of the inorganic fiber is less than 15% by weight, the linear expansion coefficient (3.0 × 10 ⁻⁵ / deg) required for the member for automobile is required.
The following) and the flexural modulus are not satisfied.

(Example 3) Examples 3 and 4 described below relate to a method for molding an automobile member and a method for producing an automobile pillar. A schematic partial end view of the mold assembly used in Example 3 is shown in FIGS. 2 (A), 2 (B) and 2 (C). In Example 3, the nest 130 was manufactured and mounted as shown in FIG. Nested from flat crystallized glass (crystallinity 70%) having a thickness of 4.5 mm, a length of 275.0 mm and a width of 85.0 mm.
0 was produced. The characteristics of this crystallized glass are shown in Example 1.
It is the same as the crystallized glass used in. And 80
The plate-shaped crystallized glass was placed on a ceramic mold having a radius of curvature of 500 mm in a high temperature furnace at 0 ° C. to naturally shape it, and then ground. After that, the cavity surface 131 of the insert 130 is polished and finished using a diamond grindstone and a cerium oxide grindstone, and the surface roughness R _max of the insert cavity 130 is 0.02 μm.
And The final size of the nest 130 is 4.0
The length was 0 mm, the length was 271.00 mm, and the width was 81.00 mm. The radius of curvature of the cavity surface 131 of the insert 130 is 500 mm.

The inner dimension of the insert fitting portion 111 provided on the fixed mold 110 is 271.20 mm × 81.20 m.
m. The insert mounting portion 111 has the same shape as the surface of the insert 130 opposite to the cavity surface 131. Next, the insert 130 was fixed in the insert mounting portion 111 with an epoxy adhesive (not shown) (see FIG. 2B). When the clearance (D) between the insert 130 and the insert mounting portion 111 was measured using a gap gauge, the minimum clearance was 0.05 mm.

Next, as shown in FIG. 2C, the holding plate 132 was manufactured. The restraining plate 132 was made of carbon steel S55C. The inner dimension of the holding plate 132 was 270.00 mm × 80.00 mm. Suppression plate 1 facing the cavity surface 131 of the nest 130
The radius of curvature of the surface of 32 was 500 mm. Next, the pressing plate 132 is screwed to the fixed mold part 110 (not shown).
Was fixed using. Nesting 130 and restraining plate 132
The average clearance (C) between and is 0.019mm
Met. The pressing margin (ΔS) of the pressing plate 132 with respect to the insert 130 was 0.5 mm.

Next, as shown in FIG. 2A, the movable mold part 120 and the fixed mold part 110 were assembled to complete the mold assembly. The dimensions of the automobile pillar are
The length is 270 mm, the width is 80 mm, the thickness is 2 mm, and the radius of curvature of the surface is 500 mm. The completed mold assembly was attached to the injection molding machine. Then, using the mold temperature controller, 130
Even after being heated to 40 ° C. and then rapidly cooled to 40 ° C., the insert 130 made of crystallized glass did not have a problem such as cracking.

A 150 MST injection molding machine manufactured by Mitsubishi Heavy Industries, Ltd. was used as an injection molding machine, and the mold assembly was 8
Heat to 0 ° C. Then, using a thermoplastic resin made of a polycarbonate resin containing 20% by weight of inorganic fibers made of aluminum borate whisker fibers shown in Table 11 below, the cavity 140 is completely filled under the injection molding conditions shown in Table 11 below. A sufficient amount of molten resin to be filled in was injected into the cavity 140 through the gate portion 113. Then, 20 seconds after the completion of injection, the automobile member (pillar member) was taken out from the mold assembly.

[0086]

[Table 11] Aluminum borate whisker fibers Average length: 10 μm Average diameter: 0.1 μm Molding conditions Mold temperature: 80 ° C Resin temperature: 310 ° C Injection pressure: 500 kgf / cm ² -G

The surface of the automobile member (the face that was in contact with the insert 130) had a mirror surface even to the end of the automobile member, even though the mold temperature was low. As a result of measuring the smoothness of the surface of the member for automobiles using a surface image clarity measuring instrument, it had a very high specularity of 95% against 100% of the perfect specular surface. Moreover, when the physical properties of the automobile member were measured, the flexural modulus was 6.0 GPa and the linear expansion coefficient was 2.
5 × 10 ⁻⁵ / deg, load deflection temperature 145 ° C.,
It was found to have the desired performance. Further, molding was continuously performed for 10,000 cycles, but no damage such as cracking occurred in the insert 130.

An acrylic hard coat solution was applied to the molded automobile member (pillar member) by a dipping method, and then the hard coat solution was completely cured by an ultraviolet irradiator to complete an automobile pillar. The completed automobile pillar has a very beautiful appearance, and has an appearance similar to that of an automobile pillar molded from a thermoplastic resin that does not contain inorganic fibers. There were no cracks in the.

(Comparative Example 3A) In Comparative Example 3A, a mold assembly was used in which the mold was made of Starbucks steel and the cavity surface of the mold was mirror-polished. The structure of the mold assembly of Comparative Example 3A has the same structure as the mold assembly of Example 3 except that the mold assembly and the restraining plate are not provided. Then, using the same thermoplastic resin as in Example 3, molding was performed under the same molding conditions as in Example 3. As a result, the fluidity of the molten resin in the cavity was poor, and the cavity could not be completely filled with the molten resin. Therefore, the injection pressure 200 kgf / cm ² -G increased, molding was conducted as 700kgf / cm ² -G. On the surface of the obtained automobile member (pillar member),
Inorganic fibers were deposited and the appearance was very poor. When the surface smoothness of the automobile member was measured with a surface image clarity measuring instrument, it was 7% with respect to 100% of perfect mirror surface, and the mirror surface property was remarkably lower than that of the automobile member of Example 3. As a result of performing a hard coat treatment on this automobile member in the same manner as in Example 3, the appearance of the surface of the obtained automobile member was inferior and cracks were generated from the end portions of the automobile member.

(Comparative Example 3B) In Comparative Example 3B, a mold assembly having a structure in which the insert 130 was held and the plate was not held was used. Then, using the same thermoplastic resin as in Example 3, molding was performed under the same molding conditions as in Example 3. As a result, the external appearance of the end portion of the automobile member was inferior, and defective appearance such as burrs occurred. Also, molding 15
The cycle generated cracks at the ends of the insert 130.

Comparative Example 3C In Comparative Example 3C, Example 3 is used.
In the mold assembly used in step 1, the clearance (C) between the pressing plate 132 and the insert 130 is 0.04 mm.
And Then, using the same thermoplastic resin as in Example 3, molding was performed under the same molding conditions as in Example 3. As a result, the molten resin intruded into the gap between the pressing plate 132 and the insert 130, and the automobile member could not be removed from the mold assembly during mold release.

Comparative Example 3D In Comparative Example 3D, Example 3 is used.
In the mold assembly used in step 1, the pressing margin (ΔS) of the pressing plate 132 with respect to the insert 130 was set to 0.05 mm. Then, using the same thermoplastic resin as in Example 3, molding was performed under the same molding conditions as in Example 3. As a result, cracks grew from the outer periphery of the insert, and cracks occurred on the entire surface of the insert in the fifth cycle of molding.

(Example 4) In Example 4, the same mold assembly as in Example 3 was used, and a thermoplastic resin prepared by adding 50% by weight of silane-coupling-treated glass fiber as an inorganic fiber to a polycarbonate resin. Molding was performed using a resin. The average length of the inorganic fibers is 70 μm and the average diameter is 1
It was 0 μm. Molding conditions include resin temperature of 330
Molding was carried out under the same conditions as in Example 3 except that the temperature was raised to ° C. An acrylic hard coat solution was applied to the molded automobile member (pillar member) by a dip method, and then the hard coat solution was completely cured by an ultraviolet irradiator to complete an automobile pillar. The completed automobile pillar has a very beautiful appearance, and has an appearance similar to that of an automobile pillar molded from a thermoplastic resin that does not contain inorganic fibers. There were no cracks in the. Table 12 shows the results of measuring the surface smoothness of the automobile member (pillar member) obtained in Example 4 with a surface image clarity measuring device and the physical property measurement results. In Table 12, the fiber length and the fiber diameter mean the average length and the average diameter of the fibers. The unit of linear expansion coefficient is 1
It is 0 ^-5 / deg.

(Comparative Example 4A to Comparative Example 4C) Comparative Example 4A to
In Comparative Example 4C, the same mold assembly as in Example 3 was used, and molding was performed using a thermoplastic resin obtained by adding glass fibers treated with silane coupling as inorganic fibers to polycarbonate resin. Table 12 shows the average lengths and diameters of the fibers. The molding conditions were the same as in Example 4.
Table 12 shows the results of measuring the smoothness of the surface of automobile members (pillar members) with a surface image clarity measuring device and the results of measuring physical properties. Despite performing the molding using the same mold assembly as in Example 4, in Comparative Example 4B and Comparative Example 4C,
The average length of the inorganic fibers was too long and the image clarity was insufficient. Further, in Comparative Example 4A, the content of the inorganic fibers was less than 15% by weight, and the linear expansion coefficient (3.0 × 10 ⁻⁵ / deg or less) and the bending elasticity required for the automobile member including the pillar member were used. Not satisfied with the rate.

[0095]

Table 12 Examples Comparative Examples -4 -4A -4B -4C Fiber length (μm) 70 70 500 500 Fiber diameter (μm) 10 10 10 10 Fiber addition amount (wt%) 50 10 10 50 Flexural modulus ( GPa) 5.0 2.5 3.5 3.5 8.8 Coefficient of linear expansion 2.8 5.2 2.8 2.1 Deflection temperature under load (° C) 145 142 143 147 Image clarity (%) 87 93 93 76 52

The present invention has been described above based on the preferred embodiments, but the present invention is not limited to these embodiments. The conditions described in the examples and the materials used are examples, and the structure of the mold assembly is also an example, and can be appropriately changed. The shapes and sizes of the nests and the restraining plates are also examples, and the design can be appropriately changed depending on the shape of the automobile member to be molded. Nesting
It may be disposed in the mold so as to face the surface portion of the automobile member that is required to have a mirror surface property, and may be provided in the movable mold part or the fixed mold part and the movable mold part as necessary. You may provide in both mold parts.

[0097]

EFFECTS OF THE INVENTION According to the method for molding an automobile member of the present invention, it is possible to obtain a high elastic modulus, a low linear expansion coefficient, and a high heat resistant heat by using a mold assembly having a nesting plate and a restraining plate. Moreover, it is possible to mold an automobile member having an extremely excellent mirror surface property.

Further, in the method for molding an automobile member of the present invention, long-term molding is carried out by suppressing the nesting within the range of the predetermined clearance (C) and the suppression margin (ΔS) by the suppression plate. Even if the insert is not damaged, a vehicle member having a mirror surface can be easily manufactured at low cost. Further, it does not impair the appearance of the end of the automobile member, it is possible to prevent the occurrence of burrs at the end of the automobile member, it is possible to reduce the defect rate and homogenize the automobile member, it is possible to achieve high quality, It is possible to reduce the manufacturing cost of automobile members.

Further, since the fluidity of the molten resin is improved, the injection pressure of the molten resin can be set low, so that the stress remaining in the automobile member can be relieved and the quality of the automobile member is improved. Furthermore, since the injection pressure of the molten resin can be reduced, it is possible to make the mold thinner and the molding apparatus smaller.
It is also possible to reduce the cost of automobile parts. It should be noted that by forming the nest from the crystallized glass, an automobile member having excellent specularity and transferability can be easily obtained. If the insert is made of crystallized glass, it is possible to make the insert having a low linear expansion coefficient, strong against thermal shock, and less likely to be damaged or cracked.

According to the method for manufacturing an automobile exterior component of the present invention, by coating the surface of an automobile member obtained by molding a fiber reinforced thermoplastic resin, high rigidity, low linear expansion coefficient and high heat resistance can be obtained. It is possible to obtain exterior parts for automobiles which are excellent in appearance and excellent in appearance. In addition, mass productivity and design freedom can be improved in the manufacture of automobile exterior parts that have excellent appearance and are lightweight.

Further, according to the method for producing an automobile pillar of the present invention, the surface of an automobile member obtained by molding a fiber reinforced thermoplastic resin is subjected to a hard coat treatment to obtain high rigidity and a low linear expansion coefficient. It is possible to obtain pillars for automobiles that have high heat resistance and excellent appearance. Moreover, it is possible to suppress the occurrence of cracks in the automobile member due to the hard coat solution.

[Brief description of drawings]

FIG. 1 is a schematic partial end view of a preferred embodiment of a mold assembly suitable for carrying out Example 1, and a schematic partial end view of the mold assembly during assembly.

FIG. 2 is a schematic partial end view of a preferred embodiment of a mold assembly suitable for carrying out Example 2, and a schematic partial end view of the mold assembly during assembly.

FIG. 3 is a schematic partial end view of a mold assembly according to a comparative example.

[Explanation of symbols]

 10,110 Fixed mold part 11.111 Nesting mounting part 12 Core 13,113 Gate part 20,120 Movable mold part 30,130 Nesting 31,131 Nesting cavity surface 32,132 Holding plate 40,140 Cavity

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // B29K 67:00 69:00 71:00 77:00 81:00 105: 12 B29L 31:30

Claims (15)

[Claims] 1. A method of manufacturing a member for a vehicle made of a thermoplastic resin, comprising: (a) a mold for molding a member for a vehicle, which is provided with a cavity; and (b) inside the mold. A glass or ceramic nest having a thickness of 0.5 mm to 10 mm, which is disposed in the mold and constitutes a part of the cavity; and It consists of a restraining plate that holds the end of the insert, and the clearance between the insert and the holding plate is 0.00.
Made of a thermoplastic resin by filling the cavity with a fiber reinforced thermoplastic resin using a mold assembly having a diameter of 1 mm to 0.03 mm or less and a pressing margin of the pressing plate with respect to the insert is 0.1 mm or more. 1. A method for molding an automobile member, which comprises forming the automobile member of 1. 2. The method for molding an automobile member according to claim 1, wherein the fiber-reinforced thermoplastic resin contains inorganic fibers. 3. The method for molding an automobile member according to claim 2, wherein the content of the inorganic fiber is 15% by weight to 80% by weight. 4. The average length of the inorganic fibers is 5 μm to 400 μm.
The average diameter is 0.01 μm to 15 μm, and the method for molding an automobile member according to claim 2 or 3, wherein 5. The inorganic fibers are glass fibers, carbon fibers,
Comprising at least one material selected from the group consisting of wollastonite, aluminum borate whisker fibers, potassium titanate whisker fibers, basic magnesium sulfate whisker fibers, calcium silicate whisker fibers and calcium sulfate whisker fibers. The method for molding an automobile member according to any one of claims 2 to 4, which is characterized in that. 6. The molding of an automobile member according to any one of claims 1 to 5, wherein the surface forming the cavity of the nest has a surface roughness R _max of 0.03 μm or less. Method. 7. The thermal conductivity of the nest is 2 × 10 ^-2 cal / c.
It is below m * sec * deg, The molding method of the member for vehicles of any one of Claim 1 thru | or 6 characterized by the above-mentioned. 8. Nesting is ZrO ₂ , ZrO ₂ —CaO, Z
_{rO 2 -Y 2 O 3, ZrO} 2 -MgO, K 2 O-TiO 2, A
_{l 2 O 3, Al 2 O} 3 -TiC, Ti 3 N 2, 3Al 2 O 3 -2
Ceramic selected from the group consisting of SiO _2, or soda glass, quartz glass, heat resistant glass, claims 1 to 7, characterized in that it is made of glass selected from the group consisting of crystallized glass One of
Item 6. A method for molding an automobile member according to the item. 9. Nesting is ZrO ₂ --Y ₂ O ₃ or 3Al ₂ O.
9. The method for molding an automobile member according to claim 8, wherein the method is produced from a ceramic made of ₃ −2 SiO ₂ or crystallized glass. 10. The thermoplastic resin is a polyamide resin, a polycarbonate resin, a modified polyphenylene ether resin, a polyester resin, or a polycarbonate resin /
The method for molding an automobile member according to any one of claims 1 to 9, wherein the thermoplastic resin is a thermoplastic resin selected from the group consisting of polymer alloy resin compositions of polyester resins. 11. A coating film is formed on at least a part of the surface of an automobile member molded by the automobile member molding method according to any one of claims 1 to 10. Manufacturing method of automobile exterior parts. 12. The automobile according to claim 11, wherein the coating film is at least one coating film selected from the group consisting of an acrylic coating film, a urethane coating film and an epoxy coating film. For manufacturing exterior parts for automobiles. 13. The automobile exterior component is a front fender, a rear fender, a door, a hood, a roof, or a trunk fade.
Alternatively, the method for manufacturing an automobile exterior component according to claim 12. 14. A step of forming a hard coat layer on at least a part of a surface of an automobile member molded by the method for molding an automobile member according to any one of claims 1 to 10. A method for manufacturing an automobile pillar, comprising: 15. The hard coat layer comprises at least one hard coat layer selected from the group consisting of an acrylic hard coat layer, a urethane hard coat layer and a silicone hard coat layer. The method for manufacturing the automobile pillar according to claim 14.