TWI681026B - Adhesive composition and adhesive film using the same - Google Patents

Abstract

The subject of the present invention is to provide an adhesive composition, which may be easily reattached, and will not float or peel off after being adhered to the adherend, and even if it is placed in a high-temperature environment, Without changing the adhesion, it has excellent peelability, so it can also reduce the contamination of the adherend caused by residue.

The means of the present invention is an adhesive composition comprising an acrylic resin, a crosslinking agent for crosslinking the acrylic resin, a photocurable resin, and a photocuring agent for curing the photocurable resin.

Description

Adhesive composition and adhesive film using the same

The present invention relates to an adhesive composition. More specifically, it may be easily reapplied without floating or peeling. Even if it is peeled off after being placed in a high-temperature environment, there will be no adhesive composition and adhesive. Use its adhesive film.

Electronic substrates or wiring boards used in various electronic instruments are manufactured through various steps such as mounting electronic parts on the substrate, lead frame fabrication, solder processing, and heat treatment. In these steps, protect the installed electronic parts, or when the lead frame is processed or soldered, if there is no paint or solder attached to the place other than the desired place, apply a protective film that may be peeled off on the surface of the substrate, and then peel off after the operation Protective film. In this way, the protective film is composed of a layer provided with an adhesive layer on one surface of the film base material, and the adhesive film is attached to the adherend by the adhesive layer such as the electronic substrate of the adherend.

In this way, the protective film does not cause floating or peeling in each step of manufacturing the electronic substrate or the wiring substrate, and the adhesion of the substrate and the protective film is important, but when the adhesive force is too large, the electronic substrate also has ultra-thin ones. If the electronic substrate with low holding property is bonded with a protective film with strong adhesive force, there is a problem of damaging the electronic substrate itself when peeling off. In addition, after the protective film is attached to the electronic substrate or circuit board of the adherend through heat treatment and other steps, the adhesion strength of the adhesive and the adherend will be increased. When the protective film is peeled from the substrate, a part of the adhesive remains on the substrate. Contamination of the substrate may cause so-called residue.

The adhesive used for the protective film generally uses a cross-linking agent containing an acrylic resin as a main agent and an acrylic resin that can be cross-linked. By adjusting the type of acrylic resin, the type of crosslinking agent and the amount added, various properties such as adhesive force, cohesiveness, and residual properties can be suppressed. However, there is still no floating or peeling, and the peelability is good, and even if the adhesive is placed in a high-temperature environment such as heat treatment, an adhesive composition that does not improve adhesion is not realized, and an adhesive composition having such characteristics is required.

On the other hand, Japanese Unexamined Patent Publication No. 2005-307134 discloses that when an electronic component is mounted on a substrate, it is used as an adhesive tape for heat-resistant pre-fixing, and an ultraviolet curable resin composition containing three types of urethane acrylate oligomers As an adhesive, teach that even if this adhesive is used in a solder reflow furnace (200 to 300 tens of degrees Celsius), it will not change the adhesion at room temperature.

In addition, Japanese Patent Laid-Open No. 2002-348543 or Japanese Patent Laid-Open No. 2009-35717 discloses that a specific acrylic resin is used as a main agent, and a pressure-sensitive adhesive using an ultraviolet curing resin is used as a cross-linking agent. Reduce adhesion and increase cohesion.

[Previous Technical Literature]

[Patent Literature 1] JP 2005-307134

[Patent Document 2] JP 2002-348543

[Patent Document 3] JP 2009-35717

The inventors have recently gained insights by adding a photo-curable resin and hardening the photo-curable resin to an acrylic adhesive (that is, an adhesive containing an acrylic resin and a cross-linking agent that cross-links the acrylic resin). The photo-initiator hardens the photo-curable resin, and the initial adhesion is low, so even if there is no self-supporting film-like adherend, it may be easily reattached, and there is no floating or peeling after being adhered to the adherend. Furthermore, even if it is placed in a high-temperature environment, it has excellent peelability without changing the adhesive force, and thus can reduce the contamination of the adherend caused by the residue or the like. The present invention is based on this insight.

Therefore, the object of the present invention is to provide a low initial adhesive force, so that even if there is no self-supporting film-like adherend, it can be easily reattached, and there is no floating or peeling after being adhered to the adherend. Placed in a high-temperature environment without changing the adhesive force, it has excellent peelability, so it can also reduce the adhesive composition that is contaminated by the adhesive body caused by the residue and the adhesive film used.

The adhesive composition of the present invention contains a cross-linking agent for cross-linking the acrylic resin and the acrylic resin, and a photo-hardening agent for curing the photo-curable resin and the photo-curable resin. .

In addition, in the embodiment of the present invention, it is preferable that the acrylic resin system has (meth)acrylate as a main component, and the glass transition temperature is 30° C. or lower.

Moreover, in the embodiment of the present invention, the mass average molecular weight of the acrylic resin is preferably 5 to 1 million.

In addition, in the embodiment of the present invention, the crosslinking agent-based thermosetting epoxy-based compound or thermosetting isocyanate-based compound is preferred.

Furthermore, in an embodiment of the present invention, the photocurable resin is selected from the group consisting of urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, polyethylene acrylate, polysiloxane acrylate and At least one type of polyol acrylate is preferred.

In addition, in the embodiment of the present invention, it is preferable that the photocurable resin is contained in the range of 5 to 60% by mass for the acrylic resin.

In addition, in the embodiment of the present invention, it is preferable that the crosslinking agent system contains the acrylic resin in the range of 0.5 to 20% by mass.

An adhesive film according to another embodiment of the present invention is an adhesive film formed by a substrate and an adhesive layer provided on one side of the substrate, the adhesive layer is composed of an adhesive containing any of the foregoing embodiments Made of things, The acrylic resin in the adhesive composition is cross-linked, and the curing of the photocurable resin is characteristic.

In addition, in the embodiment of the present invention, it is preferable to provide a release sheet on the surface on the other side from the substrate side of the adhesive layer.

Another method for manufacturing an adhesive film according to another aspect of the present invention is a method for manufacturing an adhesive film including a substrate and an adhesive layer provided on one surface of the substrate, including the following steps as features, on one surface of the substrate Applying the adhesive composition of any one of items 1 to 7 of the patent application range, cross-linking the acrylic resin by heating the adhesive composition, and irradiating the adhesive composition with light to harden the light The resin hardens to form an adhesive layer.

In addition, in the embodiment of the present invention, after applying the adhesive composition and before performing the heating and/or light irradiation, the adhesive composition is dried, and then, on the surface of the dried adhesive composition It is better to provide a release sheet to form a laminate.

According to the present invention, by adding an acrylic adhesive (that is, an adhesive containing an acrylic resin and a cross-linking agent that cross-links the acrylic resin) to the photo-curable resin and the photo-initiator that hardens the photo-curable resin, The hardened photo-curable resin has low initial adhesion, so even if it does not have a self-supporting film-like adherend, it may be easily reattached, and it will not float or peel off after being adhered to the adherend. high temperature In the environment, it has excellent peelability without changing the adhesive force, so it can also reduce the contamination of the adherend caused by the residue. In addition, the adhesive composition of the present invention is a silicon-free, which does not contain a polysiloxane-based adhesive, and can be used as an adhesive film (masking sheet) for various electronic devices.

[Forms for carrying out the invention] <Adhesive composition>

The adhesive composition of the present invention contains, as essential components, an acrylic resin, a crosslinking agent that crosslinks the acrylic resin, a photocurable resin, and a photocuring agent that hardens the photocurable resin. Hereinafter, each component constituting the adhesive composition will be described.

<Acrylic resin>

As the acrylic resin constituting the adhesive composition of the present invention, an acrylic resin containing (meth)acrylate as a main component can be suitably used. In addition, (meth)acrylic acid in this specification means acrylic acid and/or methacrylic acid. As the (meth)acrylate, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isoamyl ester, hexyl ester, Heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, isononyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, Tetradecyl esters, hexadecyl esters, octadecyl esters, eicosyl esters, etc., having a carbon number of 1 to 30, especially a straight chain of carbon number 1 to 18 (Meth)acrylic acid alkyl esters such as alkyl esters or branched chain esters and cycloalkyl (meth)acrylic acid esters such as cyclopentyl esters and cyclohexyl esters. These acrylates may contain one kind or two or more kinds.

In the present invention, modification of cohesive strength, heat resistance, etc. is aimed for, and other monomers or oligomers may be included as copolymerization components as necessary. In addition to the above (meth)acrylate, copolymerization may be used as described later Monomer or oligomer. Examples of functional group-containing (meth)acrylates that may be copolymerized with the aforementioned (meth)acrylates include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth) ) Acrylate, itaconic acid ester, maleic acid, fumaric acid, crotonic acid and other carboxyl group-containing monomers, maleic anhydride, itaconic acid anhydride and other acid group-containing monomers, 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10- Hydroxydecyl (meth)acrylate, 12-hydroxydodecyl (meth)acrylate, (4-hydroxymethylcyclohexyl) (meth)acrylate, N-hydroxymethyl (meth) Hydroxy-containing monomers such as acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, styrene sulfonic acid, allyl Sulfonic acid, 2-(meth)acrylamide-2-methylpropylsulfonic acid, (meth)acrylamidepropylsulfonic acid, sulfopropyl (meth)acrylate, (methyl) Sulfonic acid group-containing monomers such as acryloyloxynaphthyl sulfonic acid, phosphoric acid group-containing monomers such as 2-hydroxyethylacryl acetyl phosphate, glycidyl (meth)acrylate, allyl glycidyl ether, etc. Contains epoxy group monomers, vinyl acetate and other vinyl esters, styrene and other aromatic Group vinyl compounds and vinyl ethers such as ethyl vinyl ether.

In addition, as the copolymerization component, cyano group-containing monomers such as acrylonitrile, amide group-containing monomers such as acrylamide, and amine group-containing groups such as N,N-dimethylaminoethyl (meth)acrylate can also be used Monomers, isocyanate group-containing monomers and other monomers containing nitrogen atoms.

Although the acrylic resin (copolymer) used in the present invention can be obtained by polymerizing the above-mentioned monomers by ordinary solution polymerization, bulk polymerization, emulsification polymerization, or suspension polymerization, etc., it is obtained as a solution It is preferable to obtain solution polymerization to produce the acrylic resin. By obtaining the above-mentioned acrylic resin as a solution, it can be directly used for the production of the adhesive composition of the present invention.

Examples of the solvent used in the solution polymerization include organic solvents such as ethyl acetate, toluene, n-hexane, acetone, and methyl ethyl ketone. In addition, examples of the polymerization initiator used for polymerization include peroxides such as benzoyl peroxide and lauryl peroxide, azo compounds such as azobisisobutyronitrile and azobisvaleronitrile, and high molecular azo compounds. Nitrogen polymerization initiators, etc., can be used alone or in combination. In addition, for the molecular weight of the acrylic resin in the above polymerization, a conventionally known chain transfer agent can be used.

The mass average molecular weight of the acrylic copolymer described above is preferably in the range of 50,000 to 1 million, and more preferably in the range of 100,000 to 800,000. When the mass average molecular weight is less than 100,000, the adhesiveness of the adhesive composition may deteriorate, and when the mass average molecular weight exceeds 1 million, the coatability of the adhesive composition may deteriorate. In addition, GPC (gel permeation chromatography) can be used to determine the mass average score using styrene standard samples Subweight.

In the present invention, the acrylic resin preferably has a glass transition temperature of 30°C or lower. By using an acrylic resin with a glass transition temperature of 30°C or less as the main agent of the adhesive, the compatibility of the acrylic resin and other components can be improved while maintaining the cohesive force of the adhesive. The glass transition temperature of better acrylic resin is -15~20℃. The glass transition temperature of the acrylic resin can be suitably adjusted by changing the types of monomer units used or the ratio of monomer units combined, and the like. Even if the acrylic resin is polymerized alone (homopolymer), although the glass transition temperature falls within the above range, the method in which the glass transition temperature of the homopolymer does not fall within the above range is not limited by the use of monomer units . In the present invention, the glass transition temperature of the polymer which is copolymerized by combining various monomer units is only limited to the above range. For example, the glass transition temperature of a polymer (homopolymer) that polymerizes n-butyl (meth)acrylate alone is -54°C, and the glass transition temperature of a polymer (homopolymer) that polymerizes methyl acrylate alone Department of 6 ℃. In addition, the glass transition temperature of polyacrylonitrile is 101°C. Therefore, by appropriately combining the monomer units, an acrylic resin having a glass transition temperature of 30°C or lower can be made. In addition, the glass transition temperature of the polymer in the present invention means a value measured by a method (DMA method) based on the peak value of the loss tangent (tan δ). Furthermore, the loss tangent is determined by the value of the loss elastic modulus/storage elastic modulus. The elastic modulus is measured using a dynamic viscoelasticity measuring device when stress is applied to the polymer at a constant frequency.

<crosslinking agent>

The adhesive composition of the present invention contains a cross-linking agent for cross-linking the acrylic resin. By adding a cross-linking agent, adhesion can be improved while maintaining adhesion strength. As the crosslinking agent, if it is a thermosetting crosslinking agent, conventionally known ones can be used, and examples thereof include polyfunctional epoxy-based compounds and isocyanate-based compounds.

Examples of polyfunctional epoxy-based compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, and trimethylolpropane poly Glycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Polybutadiene diglycidyl ether, etc.

In addition, examples of the isocyanate-based compound include polyisocyanate compounds, trimers of polyisocyanate compounds, isocyanate-carbamate prepolymers obtained by reacting polyisocyanate compounds and polyol compounds at the ends, and the aminomethacrylates. Trimers of ester prepolymers, etc. Examples of the polyisocyanate compound include 2,4-tolyl diisocyanate, 2,5-tolyl diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, and diphenyl Methane-4,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclic Hexyl methane-2,4'-diisocyanate, amine acid isocyanate, etc. These crosslinking agent systems can be used alone or in combination of two or more.

The acrylic resin preferably contains a crosslinking agent in the range of 0.1 to 20% by mass. By setting the addition amount of the cross-linking agent to the above range, the cohesiveness can be improved while suppressing the initial adhesive force of the adhesive, and as a result, it can be easily reapplied and does not occur after being adhered to the adherend Floating or peeling adhesive. Preferably, the amount of crosslinking agent added is 0.5 to 10% by mass.

<Photocurable resin>

In addition to the acrylic resin and the cross-linking agent, the adhesive composition of the present invention also includes a photo-curable resin. The photo-curable resin here means a precursor or a composition that is irradiated with active light, and the active light-curable resin is cured by irradiating active light to cure the active light-curable resin. Also, active light means radiation that acts chemically on the active light-curing resin to promote polymerization, specifically as visible light, ultraviolet light, X-rays, electron rays, α rays, β rays, γ rays Etc.

In addition to the acrylic resin and the cross-linking agent, in the present invention, by also containing a photo-curable resin and a photo-initiator, it may be easy to reattach, and there is no floating or peeling after bonding to the adherend, and Even if it is placed in a high-temperature environment, it does not change the adhesion and has excellent peelability, so it can also reduce the contamination of the adherend caused by residue. Although the reason is not clear, consider the following. That is to say, it is conceivable that the conventional acrylic adhesives are thermally cross-linked with acrylic resins. When the adhesives are placed in a high-temperature environment, cross-linking reactions will occur, resulting in problems such as residue, but with the present invention The photo-curable resin is included, and the photo-curable resin in the adhesive composition is cured by heat to become a photo-curable resin while the adhesive is moderately hardened. Even if the cross-linking reaction of the acrylic resin proceeds, there is no residue. Adhesive with excellent peelability such as paste.

As the photocurable resin that can be used in the present invention, a radical polymerizable compound that can be polymerized by irradiation with ionizing radiation can be used, and it can be used without particular limitation. For example, acrylic groups, vinyl groups, allyl groups, Propylene-based monomers, oligomers, prepolymers, etc. having radical polymerizable unsaturated groups. As such a compound, it is preferable to use urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, polyethylene acrylate, polysiloxane acrylate, and polyol acrylate. Examples of such acrylate-based photocurable compounds include 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, and nonyl Phenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydrofurfuryloxy caprolactone, acrylate of 1,3-dioxanol ε-caprolactone adduct, Monofunctional acrylates such as 1,3-dioxolane acrylate, or the substitution of these acrylates with methyl acrylate, itaconic acid ester, crotonic acid ester, maleate methacrylic acid, itaconic acid, Crotonic acid, maleic acid ester, such as ethylene glycol diacrylate, triethylene glycol diacrylate, pentaerythritol diacrylate, hydroquinone diacrylate, resorcinol diacrylate, hexanediol diacrylate Acrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, hydroxytrimethylacetic acid neopentyl glycol diacrylate, neopentyl glycol adipate diacrylate, hydroxytrimethyl acetate new Diacrylate of ε-caprolactone adduct of pentanediol, 2-(2-hydroxy-1,1-dimethylethyl)-5-hydroxymethyl-5-ethyl-1,3- Ε-caprolactone adduct of dioxane diacrylate, tricyclodecane dihydroxymethacrylate, tricyclodecane dihydroxymethacrylate, diglycidyl ether of 1,6-hexanediol Difunctional acrylates and other bifunctional acrylates, or the substitution of these acrylates with methyl acrylate, itaconic acid ester, crotonic acid ester, maleate methacrylic acid, itaconic acid ester, crotonic acid, maleic acid Acid esters, such as trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, Dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol triacrylate, n-propionic acid‧dipentaerythritol triacrylate, n-propionic acid‧di Multifunctional acrylate acids such as pentaerythritol tetraacrylate, hydroxyneopentyl acetaldehyde modified dimethylolpropane triacrylate, or substitution of these acrylates with methyl acrylate, itaconic acid ester, crotonic acid ester, horse Methacrylic acid, itaconic acid, crotonic acid, maleate, phosphazene monomer, triethylene glycol, isocyanuric acid EO modified diacrylate, isocyanuric acid EO modified triacrylic acid Ester, dimethylol tricyclodecane diacrylate, trimethylolpropane acrylic acid benzoate, alkylene glycol type acrylic acid modified, urethane modified acrylic acid ester, etc. Among these, 2-functional monomers or oligomers can be suitably used.

Also, in the present invention, from the viewpoint of compatibility with acrylic resins, for example, bisphenol A‧epichlorohydrin‧(meth)acrylic acid, epoxidized bisphenol A diacrylate, phenol novolac can be suitably used clear Lacquer‧Epichlorohydrin‧(Meth)acrylic acid introduced into epoxy resin of (meth)acrylic acid epoxy acrylate or such as ethylene glycol‧adipic acid‧tolyl diisocyanate‧2-hydroxyethyl acrylic acid Ester, polyethylene glycol‧tolyl diisocyanate‧2-hydroxyethyl acrylate, hydroxyethyl phthalate methyl acrylate‧xylene diisocyanate, 1,2-polybutadiene glycol‧toluene Diisocyanate, 2-hydroxyethyl acrylate, trimethylolpropane, propylene glycol, tolyl diisocyanate, 2-hydroxyethyl acrylate, and amino acid of (meth)acrylic acid introduced into the urethane resin Acrylate.

In the present invention, the acrylic resin preferably contains a photocurable resin in the range of 5 to 60% by mass. By including the photo-curable resin in the above-mentioned range, it is possible to balance the adhesion strength at a higher level when placed in the initial adhesion strength, cohesive strength, and high-temperature environment. The content of the preferred photocurable resin is 5-40% by mass.

The adhesive composition of the present invention contains the photo-curable resin hardening photo-initiator. As a photo-initiator, if the active radical polymerization initiation function is exerted by light irradiation, there are no particular restrictions on the use, and it can be used. When urethane acrylate is used as the photocurable resin, 2-2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, acetophenone, benzoin, benzene Azoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzene diphenyl sulfide, tetramethyl thiuram, azobisisobutyronitrile, diphenylmethyl, diethyl acetyl, β -Chloroanthraquinone, 1-hydroxy-cyclohexyl-phenyl-one, 2-hydroxy-2-methyl-1-phenyl-propyl-1-one, 2-methyl-1[4-(methyl Thio)phenyl]-2-morpholinyl-1-one, 2-benzyl-2-dimethylamino-1- (4-Morpholinephenyl)-butanone-1, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyl- Known photoinitiators such as phenyl-phosphine oxide. These can be used alone or in combination of two or more. Among these, when the adhesive composition is irradiated with light, even if it is irradiated with light through a substrate or a release sheet as described later, the photocurable resin can be surely cured, and it is preferable to use a heat-resistant double (2,4,6-trimethylbenzyl)-phenylphosphine oxide or 2,4,6-trimethylbenzyl-phenyl-phosphine oxide and other bis-acetylphosphine initiators.

Furthermore, with the adhesive composition of the present invention, if necessary, improvement and modification such as processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, flame resistance For moldability, electrical properties, strength, other properties, etc., colorants such as slip agents, plasticizers, fillers, fillers, antistatic agents, anti-adhesive agents, crosslinking agents, light stabilizers, dyes, pigments, etc. can also be added , Other agents, etc. Furthermore, if necessary, a coupling agent such as a silane-based, titanium-based, or aluminum-based coupling agent may be included.

With the adhesive composition of the present invention, the above components are mixed, kneaded and dispersed as necessary, and can be prepared. The mixing and dispersion methods are not particularly limited, and general kneading and dispersing machines can be applied, such as double-roller mill, triple-roller mill, gravel mill, drum mill, Szegvari ultrafine attritor, high-speed impeller disperser, high-speed Stone mill, high-speed impact mill, disperser, high-speed mixer, belt mixer, compound motion kneader, strong mixer, drum, blender, distributor, homogenizer and ultrasonic disperser, etc. In addition, in order to adjust the viscosity of the adhesive coating solution, a dilution solvent may be added to mix the components.

<adhesive film>

The adhesive film of the present invention uses the above-mentioned adhesive composition as an adhesive layer, which can be a sandwich between its two sides with a release sheet, or it can be provided with a substrate and one side of the aforementioned substrate with an adhesive layer By. In addition, when an adhesive layer is provided on one surface of the substrate, a release sheet may be provided on the other surface of the adhesive layer. For the adhesive layer, one that hardens the photo-curable resin in the adhesive composition described above is used.

As the base material, various forms such as a film, a sheet, or a tape can be used depending on the application. The base material can be appropriately selected depending on the use, and is not particularly limited. From the viewpoint of water resistance or heat resistance, for example, low density polyethylene, direct-lock low density polyethylene, high density polyethylene, ethylene-propylene glycol copolymer, polypropylene, polybutene, polybutadiene, Polymethyl pentene, ethylene-vinyl acetate copolymer and other polyolefin resins, polyethylene terephthalate, polyethylene naphthalate and other polyester resins, nylon 6,6 or nylon 1,12 Acrylic acid such as polyamide resin, polyimide, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer Other than copolymerization, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polyurethane, ionomer resin, etc. By film-forming these resins into sheets or films that have been extruded and processed into a predetermined shape, various forms of film, sheet, or tape can be produced.

The thickness of the substrate is not particularly limited, as the basis of electronic circuits In the case where an adhesive film is used for a protective sheet such as a board, it may be set to a required thickness depending on its application, and a thickness of 5 to 500 μm may be used, for example.

In order to improve the adhesion between the substrate and the adhesive layer, corona treatment or primer treatment may also be applied to the surface of the adhesive composition coated with the substrate.

The adhesive film of the present invention is obtained by coating the above adhesive composition on one side of the substrate, heating and even irradiating the adhesive composition with light to harden it, and by forming an adhesive layer. The coating method of the adhesive composition of the substrate is not particularly limited, and can be applied to, for example, roll coating, reverse roll coating, transfer roll coating, gravure printing coating, and gravure reverse coating Cloth, corner wheel coating, bar coating, knife coating, bar coating, wire bar coating, pattern coating, lip coating, dip coating, etc.

After coating the adhesive composition on one side of the substrate in the present invention, the acrylic resin in the adhesive composition is crosslinked by heating, and the photocurable resin is cured by light irradiation to form an adhesive layer. The heating temperature of the acrylic resin during crosslinking (hardening) is about 50 to 150°C, preferably 90 to 120°C. The heating time is 1~240 minutes, preferably a few minutes~60 minutes. In addition, light irradiation can be performed by irradiation of ionizing radiation. For example, using a conventionally known device and irradiation of ultraviolet rays, monomers of the photocurable resin can be polymerized.

As described above, the adhesive film of the present invention can be manufactured, and in consideration of its operability, a release sheet may be provided on the surface opposite to the base material side of the adhesive layer. When setting the release sheet, apply the adhesive composition to one surface of the substrate and dry it. On the surface of the adhesive composition (opposite the side with the substrate) (Surface) After the release sheet is provided, the adhesive composition may be heated or even irradiated with light to form an adhesive layer.

As the release sheet, conventionally known ones such as release film, separation paper, separation film, release paper, release film, and release paper can be suitably used. Moreover, one or both sides of a base material for release paper such as Dowling paper, coated paper, impregnated paper, plastic film, etc. may be used to form a release layer. The material for the release layer is not particularly limited if it has a release property, and examples thereof include polysiloxane resins, organic resin-modified polysiloxane resins, fluorine resins, amino alkyd resins, melamine resins, acrylic resins, Polyester resin, etc. Any of emulsification type, solvent type or solventless type can be used for these resins.

The release sheet is formed by applying the coating liquid of the dispersed and/or dissolved release layer component to one side of the base film for release paper, and heating and drying and/or hardening. As a coating method of the coating liquid, any known coating method can be applied, such as roll coating, gravure coating, spray coating, and the like. In addition, the release layer may be formed on at least one side, the entire surface, or a part of the base film as needed.

Before the adhesive film with the release sheet is attached to the adherend, the release sheet is peeled off from the adhesive film, and the peeling surface of the adhered film is adhered to the adherend, and the adhesive film can be applied to the surface of the adherend . Therefore, the adhesive film of the present invention can be used as a shielding sheet for electronic circuit boards, etc. Even if the circuit board is ultra-thin, it may be easily re-attached, and there is no floating or Peeling, even when placed in a high-temperature environment, has excellent peelability without changing the adhesive force, and thus can reduce the contamination of circuit boards and the like through residues and the like.

[Examples]

The present invention will be described in more detail by examples, but the present invention is not limited by the contents of the examples.

Example 1 <Preparation of adhesive composition>

As a monomer unit, an acrylic copolymer resin (mass averaged) containing methyl acrylate, 2-ethylhexyl acrylate, acrylic acid, and 2-hydroxyethyl acrylate in a ratio of 50:40:0.5:9.5 on a mass basis is used. (Molecular weight: 200,000, glass transition temperature: 6℃). Dissolve 100 parts by mass of an ethyl acetate solution (solid content) of this acrylic copolymer resin in a mixed solvent of toluene and methyl ethyl ketone (trade name: KT-11, mass ratio 1:1, manufactured by DIC Graphics Corporation) 35% by mass), with 2.4 parts by mass of isocyanate (trade name: CORONATE L, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, and 7 parts by mass of 10-functional urethane as a photocurable resin Acrylic ester (trade name: U-10PPA, SHIN-NAKAMURA CHEMICAL CO. LTD), and 0.21 parts by mass of light initiator (trade name: Irgcure819, BASF Japan Ltd.), the solid content becomes 25% After the disperser was stirred at a rotation number of 500 rpm for 30 minutes, the adhesive composition was obtained by leaving until the bubbles disappeared at normal temperature.

<Production of Adhesive Film>

Using an applicator, apply the obtained adhesive composition over the entire surface to a 38 μm-thick polyester film (trade name: SP-PET-01, Mitsui Chemicals) that is easily peelable and treated with a polysiloxane-based release agent. Tohcello. Inc.), the easily peelable surface was dried in a drying oven at 100°C for 2 minutes, and then the photocurable resin was cured by irradiating ultraviolet light with a wavelength of 365 nm at 300 mJ/cm ² to form a thickness of 10 μm Adhesive layer. By laminating a polyimide film base material (trade name: Kapton 100H, manufactured by DU PONT-TORAY CO., LTD.) with a thickness of 25 μm on the surface on which the adhesive layer is formed, the adhesive film 1 is obtained.

Example 2

As the photocurable resin, 7 parts by mass of a bifunctional urethane acrylate (trade name: Beam Set 502H, manufactured by Arakawa Chemical Industries, Ltd.) was added, and an adhesive film 2 was obtained in the same manner as in Example 1.

Example 3

Instead of the acrylic copolymer resin used in Example 1, an acrylic copolymer resin (trade name: Teisanresin SG-700AS, manufactured by Nagase ChemteX Corporation) other than acrylonitrile copolymerized with (meth)acrylate was used. In the same manner as in Example 1, an adhesive film 3 was obtained.

Example 4

An adhesive film 4 was obtained in the same manner as in Example 1 except that U-200PA (manufactured by SHIN-NAKAMURA CHEMICAL CO., LTD.), which changed the photocurable resin used in Example 1 to polyester-based curable resin, was used.

Example 5

An adhesive film 5 was obtained in the same manner as in Example 1 except that the photo-curable resin used in Example 1 was changed to A-BPE-10 (manufactured by SHIN-NAKAMURA CHEMICAL CO., LTD.) of epoxy-based curable resin.

Comparative example 1 <Preparation of adhesive composition>

As the adhesive composition, a compound prepared in the same manner as in Example 1 was used except that a photocurable resin and a photohardener were not blended.

<Production of Adhesive Film>

Using an applicator, apply the obtained adhesive composition over the entire surface to a polyester film with a thickness of 38 μm that can be easily peeled off via a polysiloxane-based release agent (trade name: SP-PET-01, Mitsui Chemicals Tohcello. Inc.'s easily peelable surface was dried in a drying oven at 100°C for 2 minutes to form an adhesive layer with a thickness of 10 μm. A polyimide film base material (trade name: Kapton 100H, manufactured by DU PONT-TORAY CO., LTD.) with a thickness of 25 μm was laminated on the surface on which the adhesive layer was formed to obtain an adhesive film 4.

<evaluation of adhesion>

The obtained adhesive film was cut to a size of 25 mm × 150 mm, and the polyester film applied with an easy peeling treatment was peeled from the adhesive film to expose the adhesive layer and exposed to copper foil (trade name: RCF-T58, FUKUDA METAL FOIL & POWDER Co ., LTD.) After bonding the adhesive layer of the adhesive film, using a 2kg roller for pressure bonding, it is left at room temperature and pressure (about 23°C, about 60%RH) for 20 minutes, and then stretched by using The testing machine (Model: RTF-1150H, manufactured by A&D Company, Limited) measures the peeling of the adhesive film from the copper foil in accordance with the measurement conditions of JIS Z 0237 (tensile speed: 300 mm/min, peeling distance: 150 mm, peeling angle: 180 degrees) Interfacial adhesion (initial adhesion). In addition, after bonding the adhesive film and the copper foil and using a 2 kg roller for pressure bonding, the film was left at 230°C for 60 minutes, and then the adhesion after heating for 60 minutes under normal temperature and pressure was measured in the same manner as above (heating) Adhesion after treatment). The measurement results are shown in Table 1 below.

Use a tensile tester to visually observe whether there is adhesive remaining on the surface of the copper foil after the peel test. When no adhesive residue was observed, it was evaluated as ○, and when adhesive residue was observed, it was evaluated as ×. The evaluation results are shown in Table 1 below.

Claims (9)

An adhesive composition characterized by comprising an acrylic resin, a cross-linking agent that cross-links the acrylic resin, a photo-curable resin, and a photo-curing agent that hardens the photo-curable resin, wherein the acrylic The resin system contains (meth)acrylate (except (meth)acrylate with maleimide group) as the main component, and the glass transition temperature is -15~20℃, relative to the aforementioned acrylic resin Contains the aforementioned photocurable resin in the range of 5 to 60% by mass. For example, in the adhesive composition according to item 1 of the patent application range, the mass average molecular weight of the acrylic resin is 5 to 1 million. An adhesive composition as claimed in item 1 or 2 of the patent application, wherein the crosslinking agent is a thermosetting epoxy compound or a thermosetting isocyanate compound. The adhesive composition as claimed in item 1 or 2 of the patent application, wherein the photo-curable resin is selected from urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, polyethylene acrylate , At least one of the group consisting of polysiloxane acrylate and polyol acrylate. An adhesive composition according to item 1 or 2 of the patent application scope, wherein the cross-linking agent is included in the range of 0.5 to 20% by mass relative to the acrylic resin. An adhesive film comprising a substrate and an adhesive layer provided on one surface of the aforementioned substrate, It is characterized in that the adhesive layer is composed of the adhesive composition as described in item 1 or 2 of the patent application, crosslinks the acrylic resin in the adhesive composition, and hardens the photo-curable resin. An adhesive film according to item 6 of the patent application scope, wherein a release sheet is formed on the side opposite to the base material side of the adhesive layer. A method for manufacturing an adhesive film, comprising a substrate and an adhesive layer provided on one side of the aforementioned substrate, characterized by comprising the following steps; coating on one side of the aforementioned substrate as claimed in patent application No. 1 Or the adhesive composition of item 2, heating the adhesive composition to crosslink the acrylic resin, and curing the photocurable resin by irradiating the adhesive composition with light to form an adhesive layer. The method as claimed in item 8 of the patent application scope includes the following steps: after applying the adhesive composition, before performing the heating and/or light irradiation, drying the adhesive composition, and then drying A release sheet is provided on the surface of the adhesive composition to form a laminate.