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WO1994020586A1 - Auto-adhesif comprenant des microspheres adhesives et un liant contenant un acrylamide - Google Patents

Auto-adhesif comprenant des microspheres adhesives et un liant contenant un acrylamide Download PDF

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Publication number
WO1994020586A1
WO1994020586A1 PCT/US1994/001872 US9401872W WO9420586A1 WO 1994020586 A1 WO1994020586 A1 WO 1994020586A1 US 9401872 W US9401872 W US 9401872W WO 9420586 A1 WO9420586 A1 WO 9420586A1
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WO
WIPO (PCT)
Prior art keywords
microspheres
binder
acrylate
adhesive
acrylamide
Prior art date
Application number
PCT/US1994/001872
Other languages
English (en)
Inventor
Dale O. Bailey
Terrence E. Cooprider
Joaquin Delgado
Carol E. Macnamara
Ronald W. Most
Shirin Saadat
Original Assignee
Minnesota Mining And Manufacturing Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minnesota Mining And Manufacturing Company filed Critical Minnesota Mining And Manufacturing Company
Priority to AU62704/94A priority Critical patent/AU6270494A/en
Publication of WO1994020586A1 publication Critical patent/WO1994020586A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/08—Homopolymers or copolymers of acrylic acid esters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • C09J7/385—Acrylic polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/14—Polymer mixtures characterised by other features containing polymeric additives characterised by shape
    • C08L2205/18—Spheres
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
    • C08L2666/02—Organic macromolecular compounds, natural resins, waxes or and bituminous materials
    • C08L2666/04—Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
    • C08L33/04—Homopolymers or copolymers of esters
    • C08L33/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
    • C08L33/062—Copolymers with monomers not covered by C08L33/06
    • C08L33/064—Copolymers with monomers not covered by C08L33/06 containing anhydride, COOH or COOM groups, with M being metal or onium-cation
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/302—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C

Definitions

  • This invention relates to repositionable adhesives.
  • it relates to a composition containing a blend of microspheres and a binder.
  • Positionable adhesives are those which allow for the placement of an article containing such an adhesive onto a receptor in an exact position, because the article can be adjusted relative to the receptor after initial placement.
  • the adhesive can be designated repositionable or repeatedly reusable.
  • the term "repositionable” refers to the ability to be repeatedly adhered to and removed from a substrate without substantial loss of adhesion capability.
  • Such adhesives exhibit aggressive tack but low peel adhesion properties, thus allowing repeated reusability.
  • Commercial products such as the 3M Brand Post-ItTM Notes display such adhesive characteristics.
  • Microsphere-based adhesives are thought to perform well in such applications at least in part due to their "self- cleaning" nature wherein substrate contaminants tend to be pushed aside and trapped between the microspheres as the adhesive is applied. Upon removal, the adhesive still presents a relatively uncontaminated surface for reapplication to the substrate.
  • Such spheres having repositionable properties are disclosed in U.S. Patent No. 3,691,140 (Silver). These microspheres are prepared by aqueous suspension polymerization of alkyl acrylate monomers and ionic comonomers, e.g., sodium methacrylate, in the presence of an emulsifier, preferably an anionic emulsifier.
  • an emulsifier preferably an anionic emulsifier.
  • U.S. Patent No. 4,786,696, (Bohnel) describes a suspension polymerization process for preparing solid, inherently tacky (meth)acrylate microspheres which do not require the use of either an ionic comonomer or an ionic suspension stabilizer in order to prevent agglomeration.
  • the process requires agitation of the vessel charge prior to the initiation of the reaction sufficient to create a suspension of monomer droplets having an average monomer droplet size of between about 5 to about 70 micrometers.
  • a minor portion of a vinylic comonomer such as, e.g., acrylic acid, may be included to modify the "tacky nature" of the microspheres.
  • microspheres which can be composed of a (meth)acrylate ester and a vinyl monomer, e.g., acrylic acid.
  • the microspheres have a reactive functional group through which crosslinking is achieved.
  • tacky the spheres are said to be useful as "removable adhesives.”
  • the microspheres can contain other monomers to prevent partial transfer of the adhesive when a backing is pulled away from the substrate.
  • Useful monomers include vinyl acetate, styrene and acrylonitrile. These additional monomers may be present in amounts up to 50 percent of the (meth)acrylate ester monomer.
  • U.S. Patent No. 5,045,569 (Delgado) describes hollow, inherently tacky (meth)acrylate microspheres which can be prepared from alkyl acrylate or methacrylate monomer(s) in the presence of polar monomers such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid.
  • binders having an extremely low adhesion for the microspheres provide an excellent microsphere retaining surface.
  • a wide range of useful binders are disclosed including hard resins such as epoxy or nitrocellulose composition, soft resins such as a vinyl ether, urethanes, fluoroche icals, silicones and microcrystalline waxes.
  • soft resins include the acrylate/acid copolymers described in U.S. Reissue Patent No. 24,906 (Ulrich) .
  • microsphere adhesives may contain an adhesion promoting monomer, such as vinyl pyridine having a functionality which is unreacted during polymerization, and is, therefore, available for subsequent binding to the substrate, which may be primed.
  • the adhesion promoting monomer can be a carboxyl group which can be linked to an ionizing agent in the substrate and/or binder. It is disclosed that the binder may be blended with the microspheres.
  • the detachable adhesive sheet includes adhesives such as polyacrylic ester copolymers, polyisobutylene-series adhesives, styrene-ethylene-butylene-styrene block copolymers series adhesives.
  • the micro-balls and an adhesive are dispersed in solvent, mixed and coated, with the ratio of adhesive to micro-balls being 1:10 to about 10:1 so that all of the micro-balls are completely covered with adhesive.
  • U.S. Patent No. 4,656,218 also discloses a releasable sheet.
  • Kinoshita coats a releasable sheet with a microsphere adhesive prepared by suspension polymerization followed by emulsion polymerization wherein a latex binder is formed in situ from alpha-olefin carboxylic acids such as acrylic acid.
  • the latex is disclosed to consist of microparticles having an average diameter from about 1 to about 4 microns. Tackifiers are disclosed as preferred optional ingredients.
  • Another attempt to overcome this difficulty associated with microsphere transfer is described in U.S. Patent No. 4,822,670. (Ono et al.). Ono et al. teach the use of a removable adhesive sheet or tape comprised of adhesive fine particles attached on at least one side of a substrate through a primer resin layer.
  • the primer resin layer can comprise poly(vinylidene chloride) resins, poly(vinyl acetate) resins, polyamide resins, poly(vinyl chloride-acetate) type resins, phenol-modified epoxy resins and maleated natural rubbers.
  • the adhesive fine particles disclosed are copolymers comprising a (meth)acrylic ester which may include a functional group such as a carboxylic group.
  • U.S. Patent No. 4,994,322 discloses another way of reducing microsphere transfer.
  • Delgado et al. teaches the use of a pressure-sensitive adhesive comprising a binder copolymer and hollow, elastomeric microspheres.
  • the hollow microspheres include at least one alkyl acrylate or alkyl methacrylate ester which can be copolymerized with monomers such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid.
  • monomers such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid.
  • adhesive comprises a binder copolymer which includes a polymeric backbone containing repeating A and C monomers and from about 1% to about 20% B monomers.
  • A is a monomeric acrylic or methacrylic acid ester.
  • B is a polar monomer which can be a mono-olefinic, mono- and dicarboxylic acid or salt thereof.
  • B can also be an acrylaraide, acrylonitrile and methacrylonitrile.
  • C is a monomer having the general formula X-(Y) n -Z wherein X is a vinyl group copolymerizable with the A and B monomers, Y is a divalent linking group and Z is a monovalent polymeric moiety having a T g greater than 20°C and a molecular weight in the range of about 2,000 to about 30,000.
  • the binder copolymer has a shear storage modulus of at least 1 X 10 5 Pascals at 3 Hz and 22°C.
  • Miyasaka teaches the use of a removable adhesive composition wherein elastic microballs are crosslinked to an adhesive copolymer.
  • the microballs comprise an acrylate or methacrylate acid ester which can have at least one carboxyl group.
  • the adhesive copolymer includes an acrylate or methacrylate monomer copolymerized with at least one of the following groups: (1) a carboxyl group, (2) a hydroxyl group, (3) an amino group, i.e., acryl amide and (4) an epoxy group.
  • the two, i.e., the microballs and the adhesive copolymer are crosslinked by crosslinking agents such as polyepoxies, polyisocyanates and polyfunctional aziridines.
  • microsphere transfer can be reduced in an adhesive blend comprising microspheres and adhesive binder by utilizing carboxylated microspheres and a binder incorporating at least one acrylamide-based moiety. Unexpectedly, it has been found that there is no need to utilize a crosslinking agent with the adhesive blend.
  • the present invention comprises a blend of microspheres and an adhesive binder wherein the microspheres are not crosslinked by a crosslinking agent to the adhesive binder.
  • the microspheres which are inherently tacky and elastomeric have at least one moiety containing at least one carboxylic acid group.
  • the adhesive binder comprises a sufficient amount of at least one acrylamide-based moiety to substantially reduce microsphere transfer.
  • the composition is an aqueous blend of the microspheres and the adhesive binder.
  • the composition is an organic dispersion comprising an organic liquid, the microspheres and the binder.
  • the binder further comprises at least one acrylic acid ester and/or methacrylic acid ester copolymerized with an acrylamide.
  • droplet means the liquid stage of the microspheres prior to the completion of polymerization.
  • cavity means a space within the walls of a droplet or microsphere when still in the suspension or dispersion medium prior to drying, and thus containing whatever medium was used.
  • void means empty space completely within the walls of a polymerized microsphere.
  • the present invention involves an adhesive composition which has low microsphere transfer.
  • the composition comprises a blend of polymeric microspheres and an adhesive binder.
  • microspheres utilized in the present invention can be either hollow or solid. If the microspheres are hollow, they should comprise at least one alkyl acrylate or alkyl methacrylate ester and at least one moiety containing a carboxylic acid group.
  • Alkyl acrylate or methacrylate monomers useful in preparing the hollow microspheres for pressure-sensitive adhesives of this invention are those monofunctional unsaturated acrylate or methacrylate esters of non-tertiary alkyl alcohols, the alkyl groups of which have from 4 to 14 carbon atoms.
  • Such acrylates are oleophilic, water emulsifiable, have restricted water solubility and as homopolymers, generally have a glass transition temperature below about -20°C.
  • isooctyl acrylate 4-methyl-2-pentyl acrylate, 2-methylbutyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isodecyl methacrylate, isononyl acrylate, isodecyl acrylate and the like, singly or in mixtures.
  • Preferred acrylates include isooctyl acrylate, isononyl acrylate, isoamyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, sec- butyl acrylate and mixtures thereof.
  • Acrylate or methacrylate or other vinyl monomers which, as homopolymers, have glass transition temperatures higher than about -20°C, e.g., tert-butyl acrylate, isobornyl acrylate, butyl methacrylate, vinyl acetate, N-vinyl pyrolidone, acrylamide and the like may be utilized in conjunction with one or more of the acrylate or methacrylate monomers provided that the glass transition temperature of the resultant polymer is below about -20°C.
  • Monomers having carboxylic functionality include, but are not limited, to mono-, di-, and polycarboxylic acids, salts and mixtures thereof.
  • Preferred monomers include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid.
  • the hollow microspheres of this invention comprise at least 85 parts by weight of at least one alkyl acrylate or alkyl methacrylate ester and corresponding, up to about 15 parts by weight of one or more monomers having a carboxylic functionality.
  • the monomers having carboxylic functionality comprise up to 10 parts by weight of the hollow microsphere. More preferably, the monomers comprise from 2 to about 6 parts by weight microsphere.
  • microspheres of the present invention are prepared by aqueous suspension polymerization.
  • Suspension polymerization is a procedure whereby a monomer is dispersed in a medium usually aqueous in which it is insoluble and the polymerization allowed to proceed within the individual monomer droplets.
  • the kinetics and mechanism are essentially those for the corresponding bulk polymerization under the same conditions and initiator concentration.
  • Aqueous suspensions of the hollow microspheres may be prepared by a "two-step" emulsification process which first involves forming a water-in-oil emulsion of an aqueous solution of the carboxylic monomer in oil phase monomer, i.e., at least one acrylate or methacrylate ester, using an emulsifier having a low hydrophilic-lipophilic balance (HLB) value.
  • HLB hydrophilic-lipophilic balance
  • Suitable emulsifiers are those having an HLB value below about 7, preferably in the range of about 2 to about 7.
  • emulsifiers examples include sorbitan mono-oleate, sorbitan trileate and ethoxylated oleyl alcohol such as BrijTM 93 available from Atlas Chemical Industries, Inc.
  • oil phase monomer(s), emulsifier, a free radical initiator and optionally, a crosslinking monomer or monomers as defined below are combined, and an aqueous solution of all or a portion of the carboxylated monomer(s) is agitated and poured into the oil phase mixture to form a water-in-oil emulsion.
  • a thickening agent e.g., methyl cellulose
  • a thickening agent may also be added to the aqueous phase of the water-in-oil emulsion.
  • a water-in-oil-in-water emulsion is formed by dispersing the water-in-oil emulsion of the first step into an aqueous phase containing an emulsifier having an HLB value above about 6.
  • the aqueous phase may also contain a portion of the carboxylated monomer(s) which was not added in step one.
  • emulsifiers include ethoxylated sorbitan mono-oleate, ethoxylated lauryl alcohol and alkyl sulfates.
  • critical micelle concentration which is herein defined as the minimum concentration of emulsifier necessary for the formation of micelles, i.e., submicroscopic aggregations of emulsifier molecules.
  • Critical micelle concentration is slightly different for each emulsifier, usable concentrations ranging form about 1.0 X 10 "4 to about 3.0 moles/liter. Additional detail concerning the preparation of water-in-oil emulsions, i.e., multiple emulsions may be found in various literature references, e.g., Surfactant Systems: Their Chemistry. Pharmacy & Biology, (D. Attwood and A.T.
  • initiators are added.
  • Useful initiators are those which are normally suitable for free radical polymerization of acrylate monomers. Examples of such initiators include thermally-activated initiators such as azo compounds, hydroperoxides, peroxides and the like and photoinitiators such as benzophenone, benzoin ethyl ether and 2,2,-dimethoxy-2 phenyl acetophenone.
  • the initiator is generally used in amounts ranging from 0.01 percent up to about 10 percent by weight of the total polymerizable composition, preferably up to about 5 percent.
  • heat or radiation are applied to initiate polymerization of the monomers which is an exothermic reaction.
  • Aqueous suspensions of the hollow microspheres may also be prepared by a "one-step" emulsification process comprising aqueous polymerization of at least one alkyl acrylate or alkyl methacrylate ester monomer and one monomer having a carboxylic functionality in the presence of at least one emulsifier capable of producing a water-in-oil emulsion inside the droplets which is substantially stable during emulsification and polymerization.
  • emulsifiers having a high HLB value are desired, i.e., a value of at least about 25.
  • alkylarylether sulfates such as sodium alkylarylether sulfate, e.g., TritonTM W/30 commercially available from Rohm and Haas
  • alkylarylpolyether sulfates such as alkylarylpoly(ethylen oxide) sulfates
  • alky sulfates such as sodium lauryl sulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate and sodium hexadecyl sulfate.
  • Alkyl sulfates, alkyl ether sulfates and alkylarylether sulfates are preferred as they provide a maximum void volume per microsphere for a minimum amount of surfactant.
  • Polymeric stabilizers may also be present, but are not necessary.
  • the microsphere composition may also contain a crosslinking agent.
  • useful crosslinking agents include, but are not limited to: multifunctional (meth)acrylate(s) , e.g., butanediol diacrylate or hexanediol diacrylate or other multifunctional crosslinkers such as divinylbenzene and mixtures thereof.
  • crosslinker(s) is (are) added at a level of up to about 0.15 equivalent weight percent, preferably up to about 0.1 equivalent weight percent, of the total polymerizable composition.
  • the "equivalent weight percent" of a given compound is defined as the number of equivalents of that compound divided by the number of equivalents in the total composition wherein the equivalent is the number of grams divided by the equivalent weight.
  • the hollow microspheres are normally tacky, elastomeric, insoluble, but swellable, in organic solvents and small, typically having diameters of at least 1 micrometer to about 250 micrometers.
  • the voids typically range in size up to about 100 micrometers or larger.
  • the majority of the hollow microspheres prepared by the methods of this invention contain at least one void with a void diameter which is at least about 10% of the diameter of the microsphere, preferably at least about 20%, more preferably, at least about 30%.
  • an aqueous suspension of the hollow microspheres is obtained which is stable to agglomeration or coagulation under room temperature conditions.
  • the suspension may have non ⁇ volatile solids contents of from about 10 to about 50 percent by weight.
  • the suspension Upon prolonged standing, the suspension separates into two phases, one phase being aqueous and substantially free of polymer, the other phase being an aqueous suspension of microspheres having at least one cavity which, upon drying, becomes a void. Decantation of the microsphere-rich phase provides an aqueous suspension having a non-volatile solids content on the order of about 40-50 percent, which, if shaken with water, will redisperse.
  • the aqueous suspension may be coagulated with polar organic solvents such as methanol, with ionic emulsifiers having a charge opposite to that of the emulsifier used in the polymerization process, or with saturated salt solutions, or the like, followed by washing and drying.
  • polar organic solvents such as methanol
  • ionic emulsifiers having a charge opposite to that of the emulsifier used in the polymerization process
  • saturated salt solutions or the like
  • the partially dried microspheres with sufficient agitation will readily redisperse in common organic liquids such as ethyl acetate, tetrahydofuran, heptane, 2-butanone, benzene, cyclohexane and esters although it is not possible to resuspend them in water.
  • solid microspheres may be used.
  • solid microspheres they should comprise at least one alkyl acrylate or alkyl methacrylate ester and a monomer having at least one moiety containing a carboxylic acid functionality.
  • Alkyl acrylate or methacrylate monomers useful in preparing the solid microspheres for pressure-sensitive adhesives of this invention are those monofunctional unsaturated acrylate or methacrylate esters of non-tertiary alkyl alcohols, the alkyl groups of which have from 4 to 14 carbon atoms.
  • Such acrylates are oleophilic, water emulsifiable, have restricted water solubility and as homopolymers, generally have a glass transition temperature below about -20°C.
  • isooctyl acrylate 4-methyl-2-pentyl acrylate, 2-methylbutyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isodecyl methacrylate, isononyl acrylate, isodecyl acrylate and the like, singly or in mixtures.
  • Preferred acrylates include isooctyl acrylate, isononyl acrylate, isoamyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, sec- butyl acrylate and mixtures thereof.
  • Acrylate or methacrylate or other vinyl monomers which, as homopolymers, have glass transition temperatures higher than about -20°C, e.g., tert-butyl acrylate, isobornyl acrylate, butyl methacrylate, vinyl acetate, N-vinyl pyrolidone, acrylamide and the like may be utilized in conjunction with one or more of the acrylate or methacrylate monomers provided that the glass transition temperature of the resultant polymer is below about -20°C.
  • Monomers having carboxylic functionality include, but are not limited, mono-, di- and polycarboxylic acids, salts and mixtures thereof.
  • acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, and fumaric acid.
  • Solid microspheres can be prepared by an aqueous suspension polymerization technique utilizing emulsifiers in an amount greater than the critical micelle concentration.
  • Critical micelle concentration is defined as that minimum emulsifier concentration necessary for the formation of micelles. The critical micelle concentration is slightly different for each emulsifier. Useable concentrations typically range from about 1.0 X 10 ⁇ to about 3.0 moles per liter.
  • Anionic, nonionic or cationic emulsifiers can be used.
  • anionic emulsifiers include sodium dodecylbenzene sulfonate, sodium salts of alkyl aryl ether sulfonates and the like.
  • nonionic emulsifiers include ethoxylated oleyl alcohol and polyoxyethylene octylphenyl ether and a useful cationic surfactant is a mixture of alkyl dimethylbenzyl ammonium chlorides wherein the alkyl chain is from ten to eighteen carbons long. While only examples of anionic, nonionic and cationic emulsifiers are given herein, it is believed that amphoteric emulsifiers would likewise work.
  • Initiators effecting polymerization are those which are normally suitable for free-radical polymerization of acrylate monomers.
  • examples of such initiators include thermally-activated initiators such as azo compounds, hydroperoxides, peroxides and the like and photoinitiators such as benzophenone, benzoin ethyl ether and 2,2,-dimethoxy-2-phenyl acetophone.
  • Other suitable initiators include lauryl peroxide and bis(t-t-butyl cyclohexyl)peroxy dicarbonate.
  • the initiator concentration should be sufficient to bring about a complete monomer conversion in a desired time span and temperature range. Parameters which affect the concentration of initiator employed include the type of initiator and particular monomer and/or monomers involved.
  • effective concentrations range from about 0.10 to about 1 percent by weight of the total monomers and more preferably, from about 0.25 to about 0.70 percent by weight monomers and/or monomers.
  • Polymeric stabilizers may also be present, but are not necessary.
  • heat or radiation are applied to initiate the polymerization of the monomers which is an exothermic reaction.
  • the solid microsphere composition may also contain a crosslinking agent.
  • useful crosslinking agents include, but are not limited to: multifunctional (meth)acrylate(s) , e.g., butanediol diacrylate or hexanediol diacrylate or other multifunctional crosslinkers such as divinylbenzene and mixtures thereof.
  • crosslinker(s) is (are) added at a level of up to about 0.15 equivalent weight percent, preferably up to about 0.1 equivalent weight percent, of the total polymerizable composition.
  • the "equivalent weight percent" of a given compound is defined as the number of equivalents of that compound divided by the number of equivalents in the total composition, wherein the equivalent is the number of grams divided by the equivalent weight.
  • a stable aqueous suspension of solid microspheres at room temperature is obtained.
  • the suspension may have non-volatile solids contents of from about 10 to about 50 percent by weight.
  • the suspension Upon prolonged standing, the suspension separates into two phases, one being aqueous and in essence free of polymer and the other being an aqueous suspension of the polymeric sphere.
  • the aqueous suspension of microspheres may be utilized immediately following polymerization, because the suspension is stable to agglomeration or coagulation, under room temperature conditions. Decantation of the microsphere-rich phase provides an aqueous suspension having a non-volatile solids content, which if shaken, will readily redisperse.
  • the suspension may be coagulated with an organic liquid such as methanol, followed by washing and drying.
  • organic liquid such as methanol
  • These partially dried polymer spheres, with sufficient agitation, will readily suspend in a variety of common organic solvents such as ethyl acetate, tetrahydrofuran, heptane, 2- butanone, benzene cyclohexane and esters.
  • Suitable binders include polyacrylamides.
  • the acrylamides which can be used in the present invention are the reaction products of an acrylic or methacrylic acid with ammonia or primary or secondary amines.
  • suitable acrylamides include, but are not limited to, acrylamide, isooctyl acrylamide, 2- ethyl hexyl acrylamide, and N,N-dimethyl acrylamide.
  • the acrylamides can be copolymerized with one or more monomers having vinyl groups. Any vinyl monomer may be used so long as the product acts as a binder for the microspheres.
  • Suitable monomers include alkyl acrylates or ethacrylates.
  • Alkyl acrylate or methacrylate monomers useful in preparing the binder are those monofunctional unsaturated acrylate or methacrylate esters of non-tertiary alkyl alcohols, the alkyl groups of which have from 4 to 14 carbon atoms.
  • esters of acrylic acid or methacrylic acid with non-tertiary alkyl alcohols such as 1- butanol, 1-pentanol, 2-methyl-l-butanol, 1-methyl-l-butanol, 1-methyl-l-pentanol, 2-methyl-l-pentanol, 3- methyl-1-pentanol, 2-ethyl-l-butanol, 3,5 ,5-trimethyl- 1-hexanol, 3-heptanol, 2-octanol, 1-decanol, 1- dodecanol, isooctyl alcohol, isononyl alcohol, 2-ethyl ⁇ hexyl alcohol and the like.
  • Such monomeric acrylic or methacrylic esters are known in the art and many are commercially available.
  • the binder comprises up to about
  • the binder 15 parts acrylamide and from about 85 to about 100 parts by weight acrylic or methacrylic ester. More preferably, the binder comprises from about 4 to about 10 parts acrylamide and from about 91 to about 96 parts acrylic or methacrylic ester. It is also preferred for optimum results that the binder have an inherent viscosity ("I.V.") of at least 0.2 dl/g although lower I.V.'s can be used depending upon user preference. Most preferably, the binder should have an I.V. of least 0.6 dl./g.
  • I.V. inherent viscosity
  • the adhesive of this invention is made by combining the binder with the microspheres. If an organic dispersion of the adhesive is desired, a solution of binder is combined with an organic dispersion of microspheres. If an aqueous adhesive composition is desired, an aqueous suspension of microspheres is combined with an aqueous solution of binder.
  • the weight of the binder comprises from about 1 to about 40 parts by weight of the adhesive and the microspheres comprise from about 60 to about 99 parts by weight of adhesive of this invention.
  • Properties of the pressure-sensitive adhesives of the present invention can be altered by " the addition of a tackifying resin(s) and/or plasticizer(s) .
  • Preferred tackifiers for use herein include hydrogenated rosin esters commercially available from such companies as Hercules, Inc. under the tradenames ForalTM and PentalynTM. Individual tackifiers include those based on t-butyl styrene.
  • Useful plasticizers include dioctyl phthalate, 2-ethyl hexyl phosphate, tricresyl phosphate and the like.
  • colorants, fillers, stabilizers and various other polymeric additives can be utilized.
  • Suitable backing materials for the adhesive composition include, but are not limited to, paper, plastic films, cellulose acetate, ethyl cellulose, woven or nonwoven fabric formed of synthetic or natural materials, metal, metallized polymeric film, ceramic sheet material and the like.
  • the following examples are illustrative in nature and are not intended to limit the invention in any way.
  • Peel adhesion is the force required to remove a polyester film applied to the coated test material measured at a specific angle and rate of removal. In the examples, this force is expressed in grams per 1.25 inch width of coated sheet. The procedure followed is:
  • a strip, 1.25 inches wide, of polyester film is applied to the horizontal surface of a coated sample fixed on a test plate.
  • a 4.5 lb. hard rubber roller is used to apply the strip.
  • the free end of the polyester film is attached to the adhesion tester load cell so that the angle of removal will be 90 degrees.
  • the test plate is then clamped in the jaws of the tensile testing machine which is capable of moving the plate away from the load cell at a constant rate of 12 inches per minute.
  • a load cell reading in grams per 1.25 inches of coated strip is recorded as the polyester film is peeled from the coated samples. The samples are tested three times. The average of the three tests is reported below.
  • Microsphere transfer for the purposes of this test is defined as the amount of microsphere that transfers to an applied paper when the coated sample is removed from the paper. It is measured as the percent of the area covered with microspheres. The procedure followed is:
  • a three-quarter (3/4") wide strip of microsphere coated sample is adhered to a clean area of a clay coated paper commercially available as Kromcoat, for a few seconds using the mechanical rolling action provided by an TLMI release and adhesion tester and then is removed at a 90° degree angle at a constant rate.
  • the clay coated strip is then surveyed by an image processor through a video camera and the percent microsphere coverage of the viewed area is recorded. Ten fields are surveyed on the test sample and the average of these readings is recorded.
  • Example 1 which illustrates the use of a solvent base Isooctyl acrylate/acrylamide copolymer binder with hollow isooctyl acrylate/acrylic acid microspheres was prepared in the following manner:
  • a one liter 3-necked flask equipped with a thermometer, a reflux condenser, a mechanical stirrer, and a gas inlet tube was charged with 739 grams of deionized water, 239 grams of isooctyl acrylate, 6.12 grams of acrylic acid 0.8 grams of Lucidol 70 (a 70 percent active benzoyl peroxide, commercially available from Pennwalt Corporation) and 10 grams of 28.5 percent by weight active ammonium lauryl sulfate sold as Standapol A by the Henkel Corp.
  • the agitation was set at 600 revolutions per minute (rpm) , and the reaction mixture was purged with nitrogen.
  • the stirring and nitrogen purges were maintained throughout the reaction period.
  • the reaction mixture was allowed to stir at room temperature for 15 minutes and then was heated to 70' C to initiate the reaction. The reaction became exothermic after 30 minutes of heating. After the exotherm had subsided the batch was heated to 75 * C for 4 hours.
  • the reaction mixture was cooled to room temperature and filtered through a cheese cloth.
  • the resulting suspension was found to contain hollow microspheres with a mean diameter of 40 microns.
  • the microsphere were allowed to separate, coagulated with IPA and then re-dispersed in heptane to yield a 8% solids dispersion of copolymer microspheres in solvent.
  • the copolymer binder was prepared in a glass reaction bottle by combining 300 grams of ethyl acetate, 0.6 grams of VAZO-64, 16 grams of acrylamide, 0.08 grams of carbon tetrabromide and 184 grams of isooctyl acrylate. The bottle was then purged with Argon, sealed and tumbled in a water bath at 55°C for 24 hours.
  • the copolymer binder was then mixed with the copolymer microspheres at a 93/7 (microsphere/binder) weight ratio at 9% solids.
  • the dispersion was then coated on plain bond paper at 0.45 gm/sq.ft. dry weight.
  • the acrylate/acrylamide ratio of the binder, the weight percent of the binder in the dispersion and the test results are reported in Table 1.
  • Comparative Example 1 discloses the use of hollow isooctyl acrylate/acrylic acid copolymer microspheres alone with no binder present.
  • the adhesive of Comparative Example 1 was prepared in the following manner: The microspheres were made in accordance with the procedure outlined in Example 1. Once made, the microspheres were dispersed in heptane at 9% solids. Thereafter, the microspheres were coated onto plain bond paper at 0.45 gm/sq.ft. dry weight and tested. The test results are described in Table 1 below.
  • Examples 2-8 illustrate the use of an adhesive blend comprising a solvent-based acrylamide copolymer binder and an acrylic acid/isooctyl acrylate copolymer microsphere.
  • the blends of these examples were prepared in accordance with the procedures outlined in Example 1.
  • Binders with different amounts of acrylamide were prepared by changing the isooctyl acrylate/acrylamide ratio in the recipe. The acrylate/acrylamide ratio of the binder, the weight percent of the binder and the test results are reported in Table l.
  • test results indicate that the adhesive blend of the present invention effectively reduces microsphere even at low concentrations of binder.
  • Example 9 illustrates the use of an adhesive blend comprising a water-based acrylamide binder and solid isooctyl/acrylic acid microspheres.
  • the adhesive was prepared in the following manner: A one liter 3-necked flask equipped with a thermometer, a reflux condenser, a mechanical stirrer and a gas inlet tube was charged with 739 grams of deionized water, 239 grams of isooctyl acrylate, 14.7 grams of acrylic acid, 0.8 gram Lucidol 70 and 10 grams of sodium alkyl aryl polyether sulfonate commercially available as Triton X 200 from the Rohm and Haas Company of Philadelphia, Pennsylvania.
  • the mixture was then stirred by an agitator at a rate of 600 revolutions per minute and was purged with nitrogen. The stirring and the nitrogen purge was maintained throughout the reaction period.
  • the reaction mixture was allowed to stir at room temperature and was then heated to 70°C to initiate the reaction. After 30 minutes of heating, the reaction became exothermic.
  • the mixture was heated to 75°C for four hours. Thereafter, the reaction mixture was cooled to room temperature and filtered resulting in a suspension of solid microspheres. Then the microsphere suspension was allowed to separate into two phases, the microsphere phase and the decanted phase and was then dispersed in water with 0.8 % by dry weight of a xanthan gum sold under the tradename Kelzan by the Kelco Company. Thereafter, a 48 % by weight water-based dispersion of an acrylate terpolymer containing a N-alkyl substituted acrylamide sold as Hycar 26000X222 by the B.F. Goodrich Company of Akron, Ohio was added at a 4 % concentration by dry weight.
  • Comparative Example C2 illustrates the use of an adhesive comprising a microsphere adhesive containing no carboxylate groups. No binder was utilized. The microsphere adhesive of this comparative example was prepared in accordance with the procedure outlined in Example 9 except that no acrylic acid was utilized.
  • COMPARATIVE EXAMPLES C3-5 Comparative Examples C3-5 illustrate the use of an adhesive utilizing microspheres with carboxylate groups. No binder was utilized. The microsphere adhesives were prepared in accordance with the procedure outlined in Example 9 except that differing amounts of acrylic acid were utilized. The percentage of the components and the test results are reported in Table 2.
  • Examples 11-12 also illustrate the use of a water-based acrylamide binder and were prepared in accordance with the procedure outlined in Example 9. The percent Hycar, the peel adhesion and the percent microsphere transfer are reported in Table 2. The percentage of the components and the test results are reported in Table 2.
  • COMPARATIVE EXAMPLE C6 illustrates the use of an adhesive blend comprising a microsphere adhesive containing no carboxylate groups and Hycar 2600X222.
  • the adhesive blend of this Comparative Example was prepared in accordance with the procedure outlined in Example 9 except that no acrylic acid was utilized. The percentage of the components and the test results are reported in Table 2. Table 2
  • test results indicate that microspheres having carboxylated groups have generally less microsphere transfer than those which do not.
  • test results indicate that an acrylamide binder reduces microsphere transfer. Indeed, when the composition of the present invention is used, the peel adhesion increases.
  • Examples 13-16 illustrate the use of a solvent-based acrylamide binder at percent compositions different than those disclosed in Examples 1-12.
  • the adhesive blends of these Examples were prepared in accordance with the procedures outlined in Example 1.
  • the acrylate/acrylamide ratio of the binder, the weight percent of the binder in the dispersion and the test results are reported in Table 3.
  • Example 17 illustrates the use of an organic dispersion containing hollow microspheres utilizing a carboxylic acid moiety other than that previously described in the examples.
  • the hollow microspheres of this example were prepared in the following manner:
  • the binder was prepared in the following manner: In a glass bottle, 300 grams of ethyl acetate, 0.6 grams of VAZO-64, 16 grams of acrylamide, 0.08 grams of carbon tetrabromide and 184 grams of isooctyl acrylate were combined. The bottle was then purged with argon, sealed and tumbled in a water bath at 55° C for 24 hours. The intrinsic viscosity of the polymer formed was 1.02 dl/gram.
  • Examples 18 to 21 illustrate the use of different acids in microspheres.
  • the microspheres of Examples 18-21 were prepared in accordance with the procedures outlined in Example 17 except that different acids or different amounts of acid were utilized.
  • the alkyl acrylate, the amount of alkyl acrylate, the acid and the amount of acid utilized are reported in Table 4.
  • the acrylate/acid ratio of the microsphere, the acrylate/acrylamide ratio of the binder and the test results are reported in Table 5.
  • compositions of the present invention have reduced microsphere transfer while maintaining sufficient peel adhesion.
  • COMPARATIVE EXAMPLES C7-11 Comparative Examples C7-11 describe the illustrate the adhesive transfer of microspheres when no binder is utilized. The microspheres were prepared in accordance with the procedure outlined in Example 1. The percentage of the components, the acrylate/acid ratio and the adhesive transfer are reported in Table • 6. TABLE 6

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Adhesives Or Adhesive Processes (AREA)

Abstract

L'invention concerne une composition adhésive contenant un mélange de microsphères et un liant. Les microsphères possèdent au moins une fraction contenant un groupe d'acide carboxylique et le liant adhésif contient au moins une fraction à base d'acrylamide. Le liant est essentiellement exempt de fractions polymères pendantes possédant un Tg supérieur à 20 °C et un poids moléculaire situé dans une plage de 2 000 à 30 000 environ.
PCT/US1994/001872 1993-03-01 1994-02-22 Auto-adhesif comprenant des microspheres adhesives et un liant contenant un acrylamide WO1994020586A1 (fr)

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US08/024,636 1993-03-01

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997014510A1 (fr) * 1995-10-17 1997-04-24 Minnesota Mining And Manufacturing Company Adhesifs a microbilles, a base d'eau
US6296932B1 (en) 1998-12-14 2001-10-02 3M Innovative Properties Company Microsphere adhesive coated article for use with coated papers
EP1177897A1 (fr) 2000-08-01 2002-02-06 Agfa-Gevaert N.V. Appareil de dépot de gouttelettes avec plaque à buses pouvant se fixer de manière amovible
EP1218446A1 (fr) * 1999-05-07 2002-07-03 Avery Dennison Corporation Adhesifs et leur procede de fabrication
WO2002066571A2 (fr) 2001-01-08 2002-08-29 3M Innovative Properties Company Procedes et compositions pour impression par jet d'encre de motifs ou de films autocollants sur les substrats les plus divers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4968562A (en) * 1990-02-27 1990-11-06 Minnesota Mining And Manufacturing Company Hollow acid-free acrylate polymeric microspheres having multiple small voids
EP0419020A1 (fr) * 1989-09-18 1991-03-27 Minnesota Mining And Manufacturing Company Adhésif sensible à la pression contenant des microsphères creuses collantes et liant en copolymère contenant un monomère macromoléculaire
EP0454365A2 (fr) * 1990-04-20 1991-10-30 Minnesota Mining And Manufacturing Company Adhésif sensible à la pression contenant des microsphères collantes et liantes en copolymère contenant un macromonomère
WO1992011334A1 (fr) * 1990-12-18 1992-07-09 Minnesota Mining And Manufacturing Company Reseaux polymeres a interpenetration auto-adhesifs
WO1992013924A1 (fr) * 1991-02-06 1992-08-20 Minnesota Mining And Manufacturing Company Systeme d'adhesif positionnable a resistance elevee au cisaillements

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0419020A1 (fr) * 1989-09-18 1991-03-27 Minnesota Mining And Manufacturing Company Adhésif sensible à la pression contenant des microsphères creuses collantes et liant en copolymère contenant un monomère macromoléculaire
US4968562A (en) * 1990-02-27 1990-11-06 Minnesota Mining And Manufacturing Company Hollow acid-free acrylate polymeric microspheres having multiple small voids
EP0454365A2 (fr) * 1990-04-20 1991-10-30 Minnesota Mining And Manufacturing Company Adhésif sensible à la pression contenant des microsphères collantes et liantes en copolymère contenant un macromonomère
WO1992011334A1 (fr) * 1990-12-18 1992-07-09 Minnesota Mining And Manufacturing Company Reseaux polymeres a interpenetration auto-adhesifs
WO1992013924A1 (fr) * 1991-02-06 1992-08-20 Minnesota Mining And Manufacturing Company Systeme d'adhesif positionnable a resistance elevee au cisaillements

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997014510A1 (fr) * 1995-10-17 1997-04-24 Minnesota Mining And Manufacturing Company Adhesifs a microbilles, a base d'eau
US6296932B1 (en) 1998-12-14 2001-10-02 3M Innovative Properties Company Microsphere adhesive coated article for use with coated papers
US6905763B2 (en) 1998-12-14 2005-06-14 3M Innovative Properties Company Microsphere adhesive coated article for use with coated papers
EP1218446A1 (fr) * 1999-05-07 2002-07-03 Avery Dennison Corporation Adhesifs et leur procede de fabrication
EP1218446A4 (fr) * 1999-05-07 2002-11-27 Avery Dennison Corp Adhesifs et leur procede de fabrication
US6608134B1 (en) 1999-05-07 2003-08-19 Avery Dennison Corporation Adhesives and method for making same
EP1177897A1 (fr) 2000-08-01 2002-02-06 Agfa-Gevaert N.V. Appareil de dépot de gouttelettes avec plaque à buses pouvant se fixer de manière amovible
WO2002066571A2 (fr) 2001-01-08 2002-08-29 3M Innovative Properties Company Procedes et compositions pour impression par jet d'encre de motifs ou de films autocollants sur les substrats les plus divers
US6883908B2 (en) 2001-01-08 2005-04-26 3M Innovative Properties Company Methods and compositions for ink jet printing of pressure sensitive adhesive patterns or films on a wide range of substrates

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