KR20000063981A - heat-sensitive peel-off type adhesive and film therewith - Google Patents

Abstract

PURPOSE: A heat exfoliating adhesive and adhesion film are provided that has excellent adhesion and peelability, thereby can be used for fixing tentatively electronic elements. CONSTITUTION: The heat exfoliating adhesive comprises acrylic resin dissolved in organic solvent as an adhesion component, a curing agent and a microsphere foaming agent, wherein the solid content is 10 to 60 wt% based on the total weight of adhesive. The curing agent is contained in 0.4 to 4 pts.wt. and the microsphere foaming agent is contained in 20 to 60 pts.wt., based on the 100 pts.wt. of solid content of the acrylic resin adhesive components.

Description

Heat-sensitive peel-off type adhesive and film therewith}

The present invention relates to a pressure-sensitive adhesive film that supports and fixes a component during processing of an electronic component or a component for a semiconductor, and is easily peeled off by heating after processing.

When machining parts of electronic products, it is often necessary to temporarily fix them. Conventionally, waxes or adhesives have been used for this purpose, but it takes a lot of time and money to peel off and is easy to cause damage to the parts, as well as process problems that require cleaning to remove the wax or adhesive after peeling. There was this. For this reason, the present invention is to satisfy the process improvement, yield improvement, and no-cleaning for electronic components by using an adhesive sheet mainly coated with a polymer component on a support base surface made of a polymer film and processed to facilitate peeling. .

As a method of removing the adhesive force of the adhesive sheet in the process of processing electronic components, the adhesive is cured by chemical change by UV irradiation to lose the adhesive force, and the foam is added to the adhesive to be used by heating after use. There is a method of foaming to lose adhesive force.

In the latter case, the loss of adhesive force is due to the foam contained in the pressure-sensitive adhesive being foamed by heating and irregularities occurring on the surface of the pressure-sensitive adhesive. In other words, the adhesion area with the adherend is significantly reduced by heating, so that the contact area necessary for maintaining the adhesion is not secured, thereby losing the adhesive force.

The foam used at this time can be divided into inorganic foam and organic foam. The inorganic foams include carbonium carbonate, ammonium acetate, sodium borohydride, azide and the like. Organic foams also include trichloromonofluoromethane and azo compounds such as alkanofluorides such as dichloro monofluoromethane, azobisisobutylonitrile and azodicarbonamide, toluene sulfonylhydrazide, and 4,4 '. Hydrazide compounds such as -oxybis (benzenesulfonylhydrazide) and arylbis (sulfonylhydrazide), and nitroso compounds such as N-N'-dinitrosopentamethylenetetramine. However, they differ in foaming temperature and conditions, respectively, and have a disadvantage in that foaming agent is dissolved and reacted in an organic solvent when the pressure-sensitive adhesive film is manufactured, thereby losing foaming power. Therefore, in order to solve this problem, an attempt has been made to solve such a problem by manufacturing a microsphere (micro encapsulation).

On the other hand, the pressure-sensitive adhesives generally include rubber, acrylic, styrene-conjugated diene block copolymer-based adhesives, silicone-based adhesives, and the like, but rubber, styrene-conjugated diene block copolymer-based adhesives, silicone-based adhesives, and the like have a large amount of waxes and tackifiers and their adhesives. Since the addition of other additives is required, there is a problem in that foreign materials are transferred during the adhesion of the electronic component, and in particular, when used as a heat-peelable pressure-sensitive adhesive, there is a disadvantage in that heat resistance is not good.

Here, the pressure-sensitive adhesive which contains the foam in the pressure-sensitive adhesive and balances the initial adhesive strength and the decrease in the adhesive strength due to heating, uses a high-elastic polymer having 500,000 dyne / cm 2 or more in a temperature range from normal temperature to 150 ° C, and from normal temperature to 150 ° C. The change rate of the dynamic modulus of elasticity in the temperature range should be small, but the adhesive and the adhesive film suitable for this property have not been developed yet.

The present invention has been made in view of the technical situation as described above, the adhesive film used for fixing the components in the manufacture of electronic components or semiconductor chips initially has a strong adhesive force, but easy peeling by heating after processing the parts It is an object of the present invention to provide a heat-peelable pressure-sensitive adhesive film that has a characteristic that the adhesive force disappears and thus makes the work of temporarily fixing and peeling electronic components simpler.

The present invention comprises an acrylic resin dissolved in an organic solvent, a curing agent and a micro-spherical foam foamed by heating, in order to achieve the above object, the solid content is 10-60% by weight relative to the total weight of the pressure-sensitive adhesive Provided is a pressure-sensitive adhesive for heat-peelable pressure-sensitive adhesive film.

With respect to 100 parts by weight of the acrylic resin adhesive component solids, the curing agent is 0.4 to 4 parts by weight, the micro-spherical foam is characterized in that it comprises 20 to 60 parts by weight.

The acrylic resin constituting the adhesive component is 30 to 60% by weight of butyl acrylate, 5 to 20% by weight of 2-hexyl acrylate, 10 to 30% by weight of methyl methacrylate, and 2-hydroxyethyl based on the total weight of the monomers. Characterized by copolymerizing monomers consisting of 5 to 30% by weight of the mixture of methacrylate and 2-hydroxybutyl methacrylate, 3 to 5% by weight acrylic acid and 0.01 to 3% by weight peroxide.

The curing agent is characterized in that one or two materials selected from isocyanate crosslinking agent, methylol crosslinking agent.

The copolymer of acrylonitrile copolymerized with the styrene up to 40% by weight is further added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the adhesive component solids.

In addition, the present invention provides a heat-peelable pressure-sensitive adhesive film, characterized in that the pressure-sensitive adhesive of any one of claims 1 to 4 is applied to the base film.

The base film is characterized in that consisting of a thermoplastic resin or a thermosetting resin or a copolymer thereof.

The pressure-sensitive adhesive layer is characterized in that 5-100㎛.

Hereinafter, the configuration of the invention to be described in more detail.

The present invention uses an acrylic resin as an adhesive component. As described above, rubber-based, styrene-conjugated diene block copolymer adhesives, silicone-based adhesives, and the like, which are conventionally used in the past, require a large amount of wax, a tackifier, and other additives to be mixed, so that foreign matters when the electronic component is attached In particular, when used as a heat-peelable pressure-sensitive adhesive, there is a disadvantage in that the heat resistance is not good. On the other hand, an acrylic pressure-sensitive adhesive has good heat resistance and does not require a large amount of additives such as rubber and has a relatively easy component ratio and molecular weight. And there is an advantage that there is no foreign matter remaining by the crosslinking control.

As the acrylic resin that is an adhesive component in the present invention, low molecular weight compounds having an unsaturated carbon bond are used. Specific examples thereof include butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, stearyl methacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4 -Butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, acrylamide, glycidyl methacrylate, and oligoester acrylate are used, and hydroxyl group for reactivity Polymerizable compounds, such as acrylate or methacrylate, may be used. For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxy butyl acrylate, 2-hydroxybutyl methacrylate, polyethylene glycol acrylate and polyethylene glycol methacrylate, It can obtain by making a benzoyl peroxide react here.

The acrylic resin is used by dissolving in toluene or ethyl acetate alone or in a mixed solvent. At this time, the concentration of the preferred solid is approximately 10 to 60% by weight based on the total weight of the pressure-sensitive adhesive.

As the monomer for imparting adhesion in the acrylic resin, butyl acrylate and 2-hexyl acrylate are used, wherein butyl acrylate is preferably 30 to 60% by weight of the total acrylic resin, 2-hexyl acryl It is preferable that a rate is 5-20 weight%.

As a monomer for imparting adhesive strength, methyl methacrylate is used, and the content thereof is preferably 10 to 30% by weight of the total acrylic resin.

As a monomer having excellent curability and good reactivity in the functional monoma, 2-hydroxyethyl methacrylate and 2-hydroxybutyl methacrylate are used in combination, and a preferable content is 5 to 30% by weight of the total acrylic resin.

As another monomer, acrylic acid is preferably 3 to 5% by weight of the total acrylic resin. Acrylic acid is a mixture of two or more layers in order to promote excellent adhesion to the base film as an adhesion promoter.

As the reaction accelerator, for example, a peroxide such as benzoyl peroxide is used. The content of the peroxide is preferably 0.01 to 3% by weight of the total acrylic resin.

A curing agent is added to partially crosslink the above copolymers. Isocyanate type crosslinking agent, methylol type crosslinking agent, epoxy type crosslinking agent can be used 1 type or in mixture of 2 or more types, A preferable content is added in the range of 0.4-4 weight part with respect to 100 weight part of solid content of an adhesive line powder.

In addition, in the present invention, the foaming agent foamed by the elevated temperature uses a micro-spherical foaming agent foamed at 100 to 150 ℃, the content thereof is preferably added 20 to 60 parts by weight based on 100 parts by weight of the solid content of the adhesive component.

In order to increase the effect of foaming, a low molecular weight resin composition may be added. In the present invention, a copolymer in which styrene and acrylonitrile is copolymerized at a maximum of 40% by weight is used based on 100 parts by weight of the adhesive component solids. To 20 parts by weight is added.

The base material of the present invention is made of a resin film, in order to produce a base material, a thermoplastic resin or a thermosetting resin, for example, polyvinyl chloride, polystyrene terephthalate, ethyl vinyl acetate, ethyl vinyl alcohol, low density polyethylene, medium density polyethylene, high density Polyolefin resins such as polyethylene, polypropylene, polybutadiene and copolymers of ethylene-butene and ethylene-propylene-butadiene and polystyrene may be selected, but paper, nonwoven fabric, metal foil, and the like may also be used.

In the present invention, the pressure-sensitive adhesive mixture prepared as described above is applied to a supporting substrate having a thickness of 50-300 μm, and the thickness of the pressure-sensitive adhesive layer to be applied is formed at about 5-100 μm, but is not necessarily limited thereto.

Hereinafter, the effects of the present invention will be described with reference to Examples. However, this embodiment is merely exemplary and should not be construed as limiting the scope of the present invention to this embodiment.

The adhesion test of the present invention was measured at a peeling rate of 300 m / min in accordance with JIS Z 0237 using the Korea Shinhan Science TMD-20M model was measured after 5 minutes heating at 120 ℃.

Example 1

50% by weight of butyl acrylate, 10% by weight of 2-hexyl acrylate, 25% by weight of methyl methacrylate, 5% by weight of 2-hydroxyethyl methacrylate, 5% by weight of 2-hydroxybutyl methacrylate, acrylic acid 100 parts by weight of the dry solids of the acrylic copolymer consisting of 4.5% by weight of silver and 0.5% by weight of benzoyl peroxide,

3 parts by weight of isocyanate-based crosslinking agent as a curing agent in ethyl acetate solution, 40 parts by weight of thermally planar microspheres (micro-pair F-F50D: for 120 ° C heating foaming), a copolymer of 30% by weight of styrene and acrylonitrile 10 A pressure-sensitive adhesive was prepared by blending the parts by weight, and an EA was applied to the PET film at 102 wt% and a thickness of 60 μm and dried to prepare a heat-peelable pressure-sensitive adhesive film.

Physical properties of the adhesive film before and after heating are shown in Table 1.

Example 2

5% by weight of acrylic acid is the same as Example 1, except that it does not contain benzoyl peroxide, and the physical properties before and after heating for the adhesive film are shown in Table 1.

Comparative Example 1

Thermal flatness in an ethyl acetate solution containing 10 parts by weight of a terpene-based adhesive resin, 50 parts by weight of a high softening point resin, and 2% by weight of a vulcanizing agent based on 100 parts by weight of acrylic graft rubber (methyl methacrylate: 20% by weight). 40 parts by weight of the microspheres (micro-pair F-F50D: 120 ° C heating foaming) foaming agent was prepared to prepare a pressure-sensitive adhesive and a heat-peelable pressure-sensitive adhesive film was prepared in the same manner as in Example 1. 1 is shown.

Comparative Example 2

The same as in Example 1 except that the adhesive was prepared by mixing 20 parts by weight of the thermally planar microspheres (Micropair F-F50D: 120 ° C. for heating foaming), and the physical properties of the adhesive film before and after heating were shown in Table 1. Indicated.

Comparative Example 3

Except that styrene and acrylonitrile copolymer was not added, it is the same as in Example 1 and the physical properties before and after heating for the adhesive film are shown in Table 1.

Adhesive force before heating (gf / 25mm) Adhesive force after heating (gf / 25mm) Example 1 500 0 to 5 Example 2 310 13 Comparative Example 1 550 470 Comparative Example 2 505 120 Comparative Example 3 490 20

Since the pressure-sensitive adhesive film according to the present invention is easily peeled because the pressure-sensitive adhesive is easily foamed by simple heating, when the adhesive film is used for temporary fixing during the manufacture of electronic parts, the adhesion and peeling operations are simple, thereby improving work efficiency and improving productivity. Has the effect.

Claims (8)

A pressure-sensitive adhesive for heat-peelable pressure-sensitive adhesive film comprising an acrylic resin dissolved in an organic solvent, a curing agent, and a micro-spherical foam foamed by heating as an adhesive component, and the solid content is 10 to 60% by weight based on the total weight of the adhesive. . The pressure-sensitive adhesive for heat-peelable pressure-sensitive adhesive film according to claim 1, wherein the curing agent is contained in an amount of 0.4-4 parts by weight and the micro-spherical foam is 20-60 parts by weight based on 100 parts by weight of the acrylic resin adhesive component solids. According to claim 1, wherein the acrylic resin constituting the adhesive component 30 to 60% by weight of butyl acrylate, 5 to 20% by weight of 2-hexyl acrylate, 10 to 30% by weight of methyl methacrylate relative to the total weight of the monomers , Obtained by copolymerizing monomers composed of 5 to 30% by weight of a mixture of 2-hydroxyethyl methacrylate and 2-hydroxybutyl methacrylate, 3 to 5% by weight acrylic acid and 0.01 to 3% by weight peroxide. Adhesive for heat-peelable pressure-sensitive adhesive film. According to claim 1, wherein the curing agent is an adhesive for heat-peelable adhesive film, characterized in that the mixture of one or two selected from isocyanate crosslinking agent, methylol crosslinking agent. The heat-peelable pressure-sensitive adhesive film of claim 1, wherein a copolymer of styrene and acrylonitrile copolymerized up to 40% by weight is further added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the adhesive component solids. Adhesive for. The heat-peelable pressure-sensitive adhesive film, characterized in that the pressure-sensitive adhesive of any one of claims 1 to 4 is applied to the base film. The heat-peelable pressure-sensitive adhesive film of claim 6, wherein the base film is made of a thermoplastic resin, a thermosetting resin, or a copolymer thereof. The heat-peelable pressure-sensitive adhesive film of claim 6, wherein the pressure-sensitive adhesive layer has a thickness of 5-100 µm.