JP2002363530A - Heat-sensitive adhesive composition for electronic materials, laminate, and method for producing the same - Google Patents

Abstract

(57) [Abstract] [Problem] Adhesion or adhesion can be easily performed only by heating,
Moreover, the heat-sensitive adhesive composition for electronic materials, the heat-sensitive adhesive laminate, and the like, which have excellent adhesion and transparency, and excellent blocking resistance even when stored for a long period of time, and have excellent electrical properties such as electrical insulation. To provide a manufacturing method. SOLUTION: Thermoplastic resin (A) and solid plasticizer (B)
The present invention provides a heat-sensitive adhesive composition for electronic materials characterized by having the following excellent electrical properties (a) to (e) in a delayed tack-type heat-sensitive adhesive composition containing: (B) Dielectric breakdown voltage is 11 (KV / 70 μm @ 25 ° C)
(B) The volume resistivity is 5 × 10 ¹⁷ (Ω · cm @ 25 ° C.)
(C) The surface resistivity is 3 × 10 ¹⁷ (Ω ＠ 25 ° C.) or more. (D) The dielectric constant (ε) is less than 4 (＠ 1 kHz). (E) The dielectric loss tangent (tan δ) is 0. .4 (＠ 1 kHz)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a delayed tack-type heat-sensitive adhesive composition, a heat-sensitive adhesive laminate, and a method for producing the same, which are mainly used in the field of electronic materials. The present invention relates to a heat-sensitive adhesive composition for electronic materials that exhibits tackiness by heating without heat, a heat-sensitive adhesive laminate for electronic materials used as an adhesive tape or sheet for electrical insulation, and a method for producing the same. .

[0002]

2. Description of the Related Art Conventionally, various types of adhesive tapes and the like relating to electronic materials have been used, but most of them use a silicone release agent or the like as a release layer for an adhesive layer. For example, with double-sided adhesive tape,
A release paper coated with a silicone release agent and provided with a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive on the release paper is widely used for bonding and sealing various electronic components. However, since a large amount of release paper peeled off from the double-sided pressure-sensitive adhesive tape or the like is generated as garbage, it takes time and effort to dispose of the paper, which is not preferable from the viewpoint of resource saving.

In addition, bonding of electronic parts and integrated circuits (IC)
For the production of the package, a hot melt adhesive composition, a thermocompression bonding film using the same, and the like are used. However, conventional hot-melt adhesives generally have a slow curing reaction and require a long post-cure, and also require moisture during the curing reaction to adhere to parts that are difficult to contact with outside air. Unsuitable or requires a solvent to form into a film, and residual solvent after bonding has an adverse effect. Radiation-crosslinking type is not suitable for bonding to parts that cannot be irradiated with radiation. Problem. Further, a rubber-based tape for fixing electronic components with leads used to transport the electronic components to a mounting plant for mounting electronic components with axial or radial leads, such as capacitor elements and transistor elements, on a substrate is used. A tape provided with an adhesive layer made of a pressure-sensitive adhesive is generally used. However, in the conventional tape for fixing electronic parts with leads, especially at high temperatures, the electronic parts are displaced or dropped, and a board insertion failure or the like occurs in the mounting process of the electronic parts.

In order to solve such a problem, various types have been proposed. For example, in Japanese Patent Application Laid-Open No. 2000-345116, an adhesive tape or an adhesive tape in the field of electronic materials is provided on the surface of a support. A lead or electronic component fixing tape or sheet for fixing a lead portion with an adhesive layer made of a thermoplastic elastomer or a hot melt resin, and in JP-A-2001-106994, an adhesive layer is provided on a support. An electronic component transport cover tape, wherein the adhesive layer contains an epoxidized styrene-based thermoplastic elastomer as a base polymer, particularly,
Both the surface resistivity of the support and the surface of the adhesive layer are 10 ¹³
A cover tape for transporting electronic components of Ω or less, or in Japanese Patent Application Laid-Open No. 2000-17242, the bonding of electronic components comprising a polyethylene-based copolymer having an epoxy group in a molecule as an epoxy component and a cationic polymerization catalyst. Hot melt adhesive compositions suitable for such applications have been proposed.

[0005] Despite these proposals, however, few of the above-mentioned drawbacks and problems in the field of electronic materials have been sufficiently satisfied. As a result, adhesion and adhesion can be easily performed only by heating, a release paper is not required, and a new electric insulating adhesive tape having excellent adhesiveness and transparency is strongly desired. .

On the other hand, as one of the pressure-sensitive adhesives, a so-called delayed-tack type pressure-sensitive adhesive is known and used as a delayed-tack label or the like. However, delayed tack-type adhesives have not yet been used in the field of electronic materials. The delayed tack-type adhesive is a non-adhesive at room temperature, but a layer of a heat-sensitive adhesive that develops adhesiveness by heating, for example, is formed on a label substrate, and a release paper is unnecessary, Moreover, it has an advantage that it can be easily attached to a container or the like only by heating.

[0007] The delayed tack type adhesive is usually prepared by dispersing particles of a solid plasticizer and, if necessary, particles of a tackifier in a binder resin layer having a glass transition temperature of about 0 to 30 ° C. This is to melt the solid plasticizer and thereby plasticize the binder resin to develop adhesiveness. As a solid plasticizer, for example, dicyclohexyl phthalate is well known (JP-A-61-947).
9, JP-A-7-278521, JP-A-7-278521
145352, JP-A-8-333565, etc.).

However, since delayed tack labels do not use release paper, if they are stacked and stored for a long period of time, for example, at a high temperature in the summer, plasticization of the binder resin by dicyclohexyl phthalate gradually occurs, and the labels are not separated from each other. Are adhered to each other, so-called blocking occurs. For this reason, there is a problem that a cooling device for preventing such blocking is required. Further, the conventional delayed tack label has a problem that the adhesive strength and the transparency are lost in a short period of time.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide adhesiveness and adhesion easily by simply heating, and to maintain the adhesiveness and the transparency and the blocking resistance even after long-term storage. An object of the present invention is to provide a heat-sensitive adhesive composition for electronic materials, a heat-sensitive adhesive laminate, and a method for producing the same, which are excellent and have excellent electrical insulation properties. That is, using a delayed tack type pressure-sensitive adhesive, a heat-sensitive pressure-sensitive adhesive composition for electronic materials having excellent adhesion and transparency, excellent blocking resistance even when stored for a long period of time, and excellent electric insulation is provided. Is to do.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, have found that a specific solid-state adhesive has been selected from among delayed-tack-type adhesives conventionally used for delayed-tack labels and the like. When a plasticizer compounded was selected and used as an adhesive tape for electrical insulation in the field of electronic materials, it has excellent electrical insulation properties, and also has excellent adhesion and transparency, and has excellent blocking resistance even after long-term storage. This has led to the completion of the present invention.

That is, according to the first aspect of the present invention,
An electronic material characterized by having the following excellent electrical properties (a) to (e) in a delayed tack-type heat-sensitive adhesive composition containing a thermoplastic resin (A) and a solid plasticizer (B). A heat-sensitive adhesive composition for use is provided. (B) Dielectric breakdown voltage is 11 (KV / 70 μm @ 25 ° C)
(B) Volume resistivity is 5 × 10 ¹⁷ (Ω · cm @ 25 ° C.)
(C) The surface resistivity is 3 × 10 ¹⁷ (Ω ＠ 25 ° C.) or more. (D) The dielectric constant (ε) is less than 4 (＠ 1 kHz). (E) The dielectric loss tangent (tan δ) is 0. According to the second aspect of the present invention, in the first aspect, the solid plasticizer (B) comprises a phosphate compound (a) and a phthalate compound. (B) at least one compound selected from the group consisting of a hindered phenol compound (c), a triazole compound (d), and a hydroquinone compound (e), and having a melting point of less than 150 ° C. A heat-sensitive adhesive composition for electronic materials is provided.

According to the third aspect of the present invention, the first or second aspect is provided.
Wherein the content of the solid plasticizer (B) is 30 to 1000 parts by weight based on 100 parts by weight of the thermoplastic resin (A). Is done. According to the fourth aspect of the present invention,
In any one of the first to third inventions, there is provided a heat-sensitive adhesive composition for electronic materials, further comprising a tackifier (C). Further, according to the fifth aspect of the present invention,
In any one of the first to fourth inventions, there is provided a heat-sensitive adhesive composition for electronic materials, wherein the thermoplastic resin (C) is an aqueous composition dispersed in water.

According to a sixth aspect of the present invention, there is provided a heat-sensitive adhesive for electronic materials, characterized by using the heat-sensitive adhesive composition for electronic materials according to any one of the first to fifth aspects. You. Further, according to the seventh invention of the present invention, there is provided a heat-sensitive adhesive laminate for electronic materials obtained by coating at least one surface of a substrate with the heat-sensitive adhesive for electronic materials of the sixth invention. Is done. Further, according to the eighth aspect of the present invention,
In the seventh invention, there is provided a heat-sensitive adhesive laminate for electronic materials, wherein the shape of the heat-sensitive adhesive laminate for electronic materials is a tape or a sheet.

On the other hand, according to a ninth aspect of the present invention, at least one surface of the substrate is coated with the heat-sensitive adhesive for electronic materials of the sixth aspect to form an adhesive layer. A method for producing a heat-sensitive adhesive laminate for electronic materials is provided.

As described above, the present invention relates to a delayed tack type heat-sensitive adhesive composition containing a thermoplastic resin (A) and a solid plasticizer (B), wherein (a) the dielectric breakdown voltage is 11 (KV / 70 μm @ 25 ° C.) or more; (b) volume resistivity of 5 × 10 ¹⁷ (Ω · cm @ 25 ° C.) or more;
The surface resistivity is 3 × 10 ¹⁷ (Ω ＠ 25 ° C.) or more;
A dielectric constant (ε) of less than 4 (＠ 1 kHz), and (e) a dielectric loss tangent (tan δ) of less than 0.4 (＠ 1 kHz);
The present invention relates to a heat-sensitive adhesive composition for electronic materials and a heat-sensitive adhesive laminate characterized by having excellent electrical properties, and the preferred embodiments thereof include the following. (1) In the first or second invention, the thermoplastic resin (A)
Is a heat-sensitive adhesive composition for electronic materials, wherein the heat-sensitive adhesive composition is an acrylic polymer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the heat-sensitive adhesive composition for electronic materials of the present invention will be described in detail for each item. 1. Thermoplastic resin (A) The thermoplastic resin (A) that can be used for the heat-sensitive adhesive composition for electronic materials of the present invention is not particularly limited as long as it can be plasticized to exhibit adhesiveness. However, for example, (meth) acrylic acid ester homopolymer or copolymer, styrene- (meth) acrylic acid ester copolymer, vinyl acetate- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid Ester copolymer, ethylene- (meth) acrylic acid copolymer, (meth)
Acrylate- (meth) acrylic acid copolymer, styrene-acrylonitrile- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid ester-
(Meth) acrylic acid copolymer, styrene-acrylonitrile- (meth) acrylic acid ester- (meth) acrylic acid copolymer, ethylene-vinyl acetate- (meth) acrylic acid ester copolymer, vinylpyrrolidone- (meth) An acrylic polymer containing (meth) acrylic acid or an ester thereof as a monomer, such as an acrylic ester copolymer or a styrene-butadiene- (meth) acrylic acid copolymer;
Vinyl acetate-based polymers containing vinyl acetate as a monomer, such as vinyl acetate resin and ethylene-vinyl acetate copolymer;
Synthetic rubber such as styrene-butadiene copolymer, isobutylene resin, isobutylene-isoprene copolymer, butadiene resin, styrene-isoprene copolymer, acrylonitrile-butadiene copolymer; natural rubber; and other ethylene-vinyl chloride copolymer , Vinyl chloride-vinylidene chloride copolymer, vinyl virolidone-styrene copolymer, chlorinated propylene resin, urethane resin, ethyl cellulose and the like. These thermoplastics are
They may be used alone or in combination of two or more.

Preferred thermoplastic resins include acrylic polymers (for example, acrylic copolymers containing (meth) acrylic acid ester as a monomer), vinyl acetate polymers,
Synthetic rubber, natural rubber and the like can be mentioned. Among acrylic polymers, particularly, acrylate-methacrylate copolymers (for example, C _2-10 alkyl acrylate-C _1-4 alkyl methacrylate copolymers), acrylate-methacrylic acid Ester- (meth) acrylic acid copolymer (for example, C _2-10 alkyl acrylate-C _1-4 alkyl methacrylate- (meth) acrylic acid copolymer), acrylate-styrene- (meth) Acrylic acid copolymer (for example, acrylic acid C _2-10 alkyl ester-
An acrylic acid ester such as styrene- (meth) acrylic acid copolymer) (for example, _C2-10 alkyl acrylate) and a methacrylic acid ester (for example, _C1-4 alkyl methacrylate) or styrene as a comonomer Acrylic copolymers are preferred.

Glass transition temperature (Tg) of thermoplastic resin
Can be appropriately selected in consideration of the type of the adherend and the like, as long as the adhesiveness and the blocking resistance in the case of a heat-sensitive adhesive tape or a heat-sensitive adhesive sheet are not impaired.
The temperature is about 70C, preferably about 0C to 30C. When the glass transition temperature is lower than −10 ° C., the blocking resistance tends to decrease. On the other hand, if the glass transition temperature is too high, the adhesiveness tends to decrease.

2. Solid Plasticizer (B) In the heat-sensitive adhesive composition for electronic materials of the present invention, a compound having a melting point of less than 150 ° C. can be used as the solid plasticizer (B). The solid plasticizer (B) has a melting point of 150
It is not particularly limited as long as it is lower than 0 ° C, but preferably a phosphate ester compound (a), a phthalate ester compound (b), a hindered phenol compound (c), a triazole compound (d), and a hydroquinone compound At least one compound selected from the group consisting of compounds (e) can be used. As the solid plasticizer (B), only one type may be used, or two or more types may be used in combination.

(1) Phosphate ester compound (a) In the present invention, as one of the solid plasticizers (B), the following general formula (1) or (2) having a melting point of less than 150 ° C.
Can be used. When trivalent phosphite compound is mixed with other compounds and heat-sensitive, it is not only melted but also converted to oxides and becomes an unsuitable substance. Not used in the invention.

[0021]

Embedded image

(Wherein, R ^{1 to} R ⁷ each represent a hydrocarbon group or a heterocyclic group, A represents a divalent hydrocarbon group or a heterocyclic group, and m represents 0 to 3 Indicates an integer, provided that
R ¹ , R ² and A (when m = 1 to 3), R ³ , R ⁴ and A
(When m = 1 to 3), R ¹ , R ³ and R ⁴ (when m = 0), R ⁵ , R ⁶ and R ⁷ each have at least two groups bonded to each other to contain a phosphorus atom It may form a ring. As a specific example of the phosphorus compound represented by the above chemical formula (1), for example, a compound represented by the following structural formula (3) (phenylpentaerythritol phosphate) (melting point: 1)
03 ° C) and 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester (melting point: 1
20 ° C.) (corresponding to a hindered phenolic compound), 1,4-cyclohexanedimethanol bis (diphenyl phosphate) (melting point: 97 ° C.), resorcinol bis [di (2,6-dimethylphenyl) phosphate] (melting point : 95 ° C), tri (4-methylphenyl) phosphate) (melting point: 78 ° C), triphenoxyphosphate (melting point: 65 ° C), tribenzyl phosphate (melting point: 65 ° C), and especially resorcinol bis [di (2,6-dimethylphenyl) phosphate]
(Melting point: 95 ° C.) is preferred.

Specific examples of the phosphorus compound represented by the above chemical formula (2) include, for example, trimethylphosphine oxide (melting point: 50 ° C.), triethylphosphine oxide (melting point: 50 ° C.), dipentylphosphinic acid (melting point: : 68.5 ° C).

[0024]

Embedded image

(2) Phthalate Ester Compound (b) In the present invention, a phthalate ester compound (b) having a melting point of less than 150 ° C. may be used as one of the solid plasticizers (B). it can. Phthalates are
Dicyclohexyl phthalate (melting point: 65 ° C.) or the like has been conventionally used as a solid plasticizer for delayed tack.

Specific examples of the phthalate compound other than dicyclohexyl phthalate include di-2-phenoxyethyl terephthalate (melting point: 1).
14 ° C.), bis (3,3,5-trimethylcyclohexyl) terephthalate (melting point: 133 ° C.), dimenthol phthalate (melting point: 134 ° C.), dibornyl phthalate (melting point: 136 ° C.), and dimethyl terephthalate (melting point: 141 ° C.).

(3) Hindered phenol compound (c) Next, in the present invention, a hindered phenol compound (c) having a melting point of less than 150 ° C. is also used as one of the solid plasticizers (B). be able to. Specific examples of hindered phenol compounds include, for example,
1,6-hexanediol-bis [3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate] (melting point: 106 ° C.), tetrakis [methylene-3-
(3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane (melting point: 110 ° C.), 3,
5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester (melting point: 120 ° C.),
4,4′-thiobis (2-methyl-6-t-butylphenol) (melting point: 127 ° C.), 4,4′-thiobis (3
-Methyl-6-t-butylphenol) (melting point: 128
° C), 2,2'-methylenebis (4-methyl-6-t-
Butylphenol) (melting point: 130 ° C.), 2,2′-methylenebis (4-ethyl-6-t-butylphenol)
(Melting point: 130 ° C), 2,4,6-tri-t-butylphenol (melting point: 131 ° C), and 4-hydroxy-
Methyl-2,6-di-t-butylphenol (melting point: 1
40 ° C.).

(4) Triazole Compound (d) In the present invention, a triazole compound (d) having a melting point of less than 150 ° C. can be used as one of the solid plasticizers (B). Specific examples of such a triazole compound (d) include, for example, 2- (2′-
Hydroxy-5′-t-octylphenyl) benzotriazole (melting point: 104 ° C.), 2- (2′-hydroxy-5′-methylphenyl) benzotriazole (melting point:
130 [deg.] C), 2- [2'-hydroxy-3 ', 5'-bis ([alpha], [alpha] -dimethylbenzyl) phenyl] benzotriazole (melting point: 139 [deg.] C), and 2- (2'-hydroxy-3'-). t-butyl-5'-methylphenyl) -5
-Chlorobenzotriazole (melting point: 140 ° C).

(5) Hydroquinone Compound (e) In the present invention, a hydroquinone compound (e) having a melting point of less than 150 ° C. can also be used as one of the solid plasticizers (B). Specific examples of such hydroquinone-based compounds include, for example, hydroquinone diacetate (melting point: 123 ° C.), trimethylhydroquinone diacetate (melting point: 109 ° C.), 3,4,5-
Trimethyl catechol diacetate (melting point: 120 ° C)
And the like.

In the present invention, when at least two kinds of solid plasticizers are used in combination, the ratio of the combined use is determined by the temperature at which the heat-sensitive adhesive composition for electronic materials used is at a practical temperature.
For example, the mixed solid plasticizer is appropriately selected so that the melting point of the mixed solid plasticizer is, for example, 70 to 120 ° C., preferably 80 to 110 ° C., so that heat activation can be performed at 120 ° C. or less and adhesiveness can be developed. You.

In the present invention, the solid plasticizer (B)
The total content (as solid content) is, for example, 30 to 1000 parts by weight, preferably 100 to 1000 parts by weight, more preferably 150 to 900 parts by weight, based on 100 parts by weight of the thermoplastic resin (A). In particular, it is about 200 to 800 parts by weight. If the total content of the solid plasticizer is less than 30 parts by weight, sufficient tackiness may not be exhibited during heating, and if the total content is more than 1000 parts by weight, cohesive strength is reduced and sufficient adhesive strength is not exhibited. Sometimes.

The present inventors have studied the mechanism of the development of delayed tack adhesiveness. As a result, the heat-sensitive adhesive composition for electronic materials of the present invention, as a solid plasticizer, preferably has a melting point of 1: 1.
Since it is less than 50 ° C. and is used by selecting from the above five types of solid plasticizers, it has a high electric insulation property, a high temperature at which adhesiveness is exhibited, and easily melts at a practical temperature. Not only is it plasticized, but the recrystallization of the solid plasticizer is delayed, and the adhesion lasts for a long time.

3. Tackifier (C) The heat-sensitive adhesive composition for electronic materials of the present invention comprises a thermoplastic resin (A) as a binder resin and a solid plasticizer (B).
And as a main component, and as the solid plasticizer (B),
It uses at least one compound selected from solid plasticizers having a melting point of less than 150 ° C., and further contains a tackifier (C) as required. As described above, a solid plasticizer and, if necessary, a tackifier are dispersed in a thermoplastic resin as a binder resin, and the solid plasticizer is melted by heating, thereby plasticizing the binder resin and forming an adhesive. Can be expressed.

Examples of the tackifier that can be used include terpene resins, aliphatic petroleum resins, aromatic petroleum resins, cumarone-indene resins, styrene resins, phenol resins, terpene-phenol resins, and rosin derivatives. (Rosin, polymerized rosin, hydrogenated rosin and their esters with glycerin, pentaerythritol, etc.
Resins such as resin acid dimer) and xylene resin. Two or more of these tackifiers may be used in combination.

The content of the tackifier (C) is not particularly limited, but can be appropriately selected according to the combination of the thermoplastic resin (A) and the solid plasticizer (B). It is about 10-600 parts by weight, preferably about 20-500 parts by weight, based on 100 parts by weight of the resin (A).

4. Other Additives The heat-sensitive adhesive composition for electronic materials of the present invention may further contain, in addition to the tackifier (C), conventional additives within a range that does not impair the properties, such as an antifoaming agent and an improvement in coating properties. Agents, thickeners, lubricants,
Stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), antistatic agents, antiblocking agents (inorganic particles, organic particles, etc.) may be added.

5. Heat-Sensitive Adhesive (Heat-Sensitive Adhesive Layer) The heat-sensitive adhesive composition for an electronic material of the present invention is obtained by forming (coating and laminating) a heat-sensitive adhesive layer on at least one surface of a substrate. And a heat-sensitive adhesive tape or a pressure-sensitive adhesive sheet which is a heat-sensitive adhesive laminate. That is, the heat-sensitive adhesive layer contains the thermoplastic resin (A), the solid plasticizer (B), and, if desired, the tackifier (C) and other additives. An object can be formed by coating (coating) on a substrate. For example, an aqueous composition in which a thermoplastic resin is dispersed in water is applied, or a heat-sensitive adhesive composition is dissolved in an organic solvent and applied, or a heat-sensitive adhesive composition is heated and melted. The heat-sensitive pressure-sensitive adhesive layer can be formed by performing the coating. Among these, a method of applying an aqueous composition in which a thermoplastic resin is dispersed in water is preferred.

The dispersant that can be used for dispersing the heat-sensitive adhesive composition is not particularly limited.
Any of conventionally known anionic (anionic) and nonionic (nonionic) dispersants can be used.
Examples of the anionic dispersant include a carboxylate, a sulfate, a sulfonate, and a phosphate, and among them, ammonium carboxylate is preferable. Examples of the nonionic dispersant include polyethylene glycol-type dispersants and polyhydric alcohol-type dispersants.

As the method for preparing the aqueous composition, various conventionally known methods can be employed. For example, as a preparation method, a method in which components constituting the heat-sensitive adhesive composition for electronic materials of the present invention are previously mixed and then dispersed in water, a solid plasticizer aqueous dispersion is dispersed in a thermoplastic resin emulsion or a tackifier emulsion. A method of mixing these emulsions after dispersing a liquid or a solid plasticizer to be used in combination, dispersing a solid plasticizer aqueous dispersion or a solid plasticizer to be used together in water, and then adding a thermoplastic resin emulsion and an adhesive to the dispersion. Examples of the method include a method of mixing an imparting agent emulsion. As a method of dispersing a solid plasticizer in an emulsion or water, a method of using an aqueous dispersion of a solid plasticizer, a method of dispersing a molten solid plasticizer, a method of dispersing a solid plasticizer into fine powder, and a method of fine powder Examples of the method include a method of dispersing a solid plasticizer prepared as described above.

The thermoplastic resin emulsion may be prepared by emulsion polymerization. Alternatively, a polymer may be prepared by a method other than emulsion polymerization and then emulsified by using additives as necessary. You may. For example,
An additive (eg, emulsifier, pH adjuster, acid, etc.) is added to an organic solution containing a polymer polymerized in the presence of a water-soluble organic solvent (eg, alcohol such as isopropyl alcohol), and then water is added. Then, by emulsifying, and then removing the organic solvent, a thermoplastic resin emulsion can be prepared.

The average particle size of the solid plasticizer in the aqueous composition is preferably about 0.5 to 20 μm, more preferably about 1 to 15 μm. Average particle size 0.5
If the particle size is smaller than μm, the blocking resistance may decrease, or the pulverization may require time to lower the productivity. When the average particle diameter exceeds 20 μm, the coated surface becomes rough, for example,
There is a risk that the quality of labels and sheets will be reduced.

As a method of applying (coating) the heat-sensitive adhesive composition, for example, a method using a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater, a comma coater, a gravure coater, a silk screen coater, or the like. Can be mentioned. The heat-sensitive adhesive layer can also be formed by printing using a gravure printing machine or the like. The thickness of the heat-sensitive adhesive layer is, for example, 4 to 20 μm, and preferably 5 to 15 μm.

6. Substrate The substrate in the present invention is not particularly limited, and may be an electrically insulating paper, a coated paper, a plastic sheet or film, glass, or the like for use in an electronic material, and is preferably a transparent plastic sheet. Or a film.
Examples of the polymer constituting the plastic sheet or film include polyolefins such as polyethylene and polypropylene, ethylene-vinyl acetate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, poly (meth) acrylate, and polystyrene. , Polyvinyl alcohol, ethylene-vinyl alcohol copolymer,
Cellulose derivatives such as cellulose acetate, polyesters (polyalkylene terephthalate such as polyethylene terephthalate, polybutylene terephthalate, polyalkylene naphthalate such as polyethylene naphthalate and polybutylene naphthalate), polycarbonates, polyamides (polyamide 6, polyamide 6/6, Polyamide 6
/ 10, polyamide 6/12, etc.), polyesteramide, polyether, polyimide, polyamideimide, polyetherester, and the like. Further, copolymers, blends, and crosslinked products thereof may be used. The substrate may be a single layer or multiple layers.

7. Heat-Sensitive Adhesive Laminate In the present invention, a heat-sensitive adhesive laminate in which a heat-sensitive adhesive layer is formed (coated, laminated) on at least one surface of a substrate is a heat-sensitive adhesive tape for electronic materials, Used as a heat-sensitive adhesive sheet. The heat-sensitive adhesive laminate for an electronic material of the present invention uses a solid plasticizer having a melting point of less than 150 ° C. as a solid plasticizer, so that the heat-sensitive adhesive composition has a practical temperature. , For example, 12
It can be thermally activated at 0 ° C. or lower, and can exhibit adhesiveness. After the adhesiveness is developed, the solid plasticizer does not recrystallize or delays recrystallization, and as a result, the adhesiveness develops the adhesiveness It has a lasting effect like time. Further, the heat-sensitive adhesive laminate for electronic materials of the present invention is excellent in electrical insulation, and the degree of the insulation breakdown is 11 (KV / 70 μm at 25 ° C.) which indicates the voltage at which the insulator is broken. Above, preferably 12 (KV / 70 μm @ 25 ° C.) or more, the volume resistivity indicating the electric resistance of the substance is 5 × 10 ¹⁷ (Ω · cm @ 25 ° C.)
Or more, preferably 6 × 10 ¹⁷ (Ω · cm @ 25 ° C.) or more, and the surface resistivity indicating the electric resistance of the unit surface of the insulator is 3 or more.
× 10 ¹⁷ (Ω ＠ 25 ° C.) or more, preferably 3.5 × 1
0 ¹⁷ (Ω ＠ 25 ° C.) or more, a dielectric constant (ε) showing a property related to dielectric polarization of the substance is less than 4 (＠ 1 kHz), preferably less than 3.5 (＠ 1 kHz), and a dielectric (insulator). The dielectric loss tangent (tan δ) indicating the degree of loss is 0.4
(＠ 1 kHz), preferably 0.3 (＠ 1 kHz)
It is as follows. Therefore, the heat-sensitive adhesive laminate for electronic materials of the present invention is a delayed tack type and has excellent electrical insulation properties. It can also be used for transportation, for electrical insulation inside small electronic devices, and for semiconductor manufacturing processes. Further, the heat-sensitive adhesive laminate is not limited to only the above-described heat-sensitive adhesive tape or heat-sensitive adhesive sheet, and even after being adhered to an adherend, it can maintain adhesiveness for a long period of time. It can be used for shapes and applications.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, the average particle size of the solid plasticizer was measured by a laser diffraction type particle size distribution analyzer (LA-500, manufactured by Horiba, Ltd.).
The median diameter is described.

[Preparation Example 1] (Preparation of aqueous dispersion of solid plasticizer 1) Bis (3,3,5-trimethylcyclohexyl) phthalate (melting point: 93 ° C) as a solid plasticizer (B) was placed in a container equipped with a disperser stirrer. ) 100 parts by weight, 3.5 parts by weight of a sulfonate-type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water were mixed and stirred, and then the liquid was sent to a bead mill, and the average particle diameter was adjusted. By pulverizing and dispersing to 2.2 μm (measured by HORIBA, LA-500 / the same applies hereinafter), bis (3,3,5-trimethylcyclohexyl) phthalate aqueous dispersion 1 (solid plasticizer aqueous dispersion) 1) was obtained. This aqueous dispersion 1 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 rotations).
Min) was 0.04% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 2] (Preparation of aqueous dispersion of solid plasticizer 2) Resorcinol bis [di (2,6-dimethylphenyl) phosphate] as a solid plasticizer (B) was placed in a container equipped with a disperser stirrer (melting point: (95 ° C.) 100 parts by weight, 4.5 parts by weight of a polyoxyethylene sulfate ester type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill. ,
By pulverizing and dispersing the particles until the average particle diameter became 2.2 μm, an aqueous dispersion 2 of resorcinol bis [di (2,6-dimethylphenyl) phosphate] (solid plasticizer aqueous dispersion 2) was obtained. The aqueous dispersion 2 had an aggregate generation rate of 0.4% (based on the aqueous dispersion) in a Marlon mechanical stability test (condition: 25 kg, 1000 rotations, 15 minutes). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 3] (Preparation of aqueous dispersion of solid plasticizer 3) In a vessel equipped with a disperser stirrer, dicyclohexyl phthalate (melting point: 65 ° C) 100 as a solid plasticizer (B) was added.
Parts by weight, 15 parts by weight of a sulfonate-type anionic surfactant as a dispersant, and 80 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill to have an average particle diameter of 2.2 μm. This was ground and dispersed to obtain an aqueous dispersion 3 of dicyclohexyl phthalate (aqueous dispersion 3 of a solid plasticizer). The aqueous dispersion 3 had an aggregate generation rate of 0.06% (based on the aqueous dispersion) in a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 minutes). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

The aqueous dispersions of solid plasticizers 1 to 3 prepared above
Table 1 shows the results of the evaluation of the composition of Marlon, the mechanical stability (incidence of aggregates), and the storage stability.

[0050]

[Table 1]

[Example 1] (Preparation of heat-sensitive adhesive composition 1) In the aqueous dispersion of solid plasticizer 1 prepared above, a styrene-acrylate copolymer (A) was used as the thermoplastic resin (A). An aqueous emulsion having a glass transition temperature Tg: 20 ° C), an aqueous dispersion of a polymerized rosin ester resin and water as a tackifier (C) are added, and the mixture is stirred until uniform.
A heat-sensitive adhesive composition 1 having a solid content of 50% by weight was obtained.
The mixing ratio at this time was 28 parts by weight of the thermoplastic resin (A) and 14 parts by weight of the tackifier (C) with respect to 100 parts by weight of the solid plasticizer (B).

(Preparation of Heat-Sensitive Adhesive Sheet 1) The heat-sensitive adhesive composition 1 prepared above was coated on a polyester film for electric use (thickness: 25 μm) equivalent to JEC 6147 standard of 120 ° C. (heat-resistant class E) by a bar. Using a coater, apply the coating so that the coating thickness after drying is 6 μm.
After drying for 0 second, heat-sensitive adhesive sheet 1 (finished thickness 3
1 μm).

Example 2 (Preparation of Thermosensitive Adhesive Composition 2) The solid plasticizer aqueous dispersions 1 and 2 prepared above were mixed with bis (3,3,5-trimethyl Cyclohexyl) phthalate: resorcinol bis [di (2,6-dimethylphenyl) phosphate] = 50: 50 in a solid plasticizer aqueous dispersion mixed as a thermoplastic resin (A) as a styrene-acrylate ester An aqueous emulsion of a copolymer (glass transition temperature Tg: 20 ° C),
As a tackifier (C), an aqueous dispersion of a polymerized rosin ester resin and water were added, and the mixture was stirred until it became uniform to obtain a heat-sensitive adhesive composition 1 having a solid content of 50% by weight. At this time, the blending ratio was 28 parts by weight of the thermoplastic resin (A) and 100 parts by weight of the solid plasticizer (B), and the tackifier (C)
It was 14 parts by weight.

(Preparation of heat-sensitive pressure-sensitive adhesive sheet 2) The heat-sensitive pressure-sensitive adhesive composition 2 prepared above was coated on a polyester film for electric use (thickness: 25 μm) equivalent to 120 ° C. (heat-resistant class E) of JEC 6147 standard by a bar. Using a coater, coating was performed so that the coating thickness after drying was 10 μm, and the coating was dried at 40 ° C. for 2 minutes and 30 seconds to obtain a heat-sensitive adhesive sheet 2 (finished thickness 35 μm).

[Example 3] (Preparation of heat-sensitive adhesive composition 3) In the aqueous dispersion of solid plasticizer 2 prepared above, a styrene-acrylate copolymer (A) was used as the thermoplastic resin (A). An aqueous emulsion having a glass transition temperature Tg: 20 ° C), an aqueous dispersion of a polymerized rosin ester resin and water as a tackifier (C) are added, and the mixture is stirred until uniform.
A heat-sensitive adhesive composition 3 having a solid content of 50% by weight was obtained.
The mixing ratio at this time was 28 parts by weight of the thermoplastic resin (A) and 14 parts by weight of the tackifier (C) with respect to 100 parts by weight of the solid plasticizer (B).

(Preparation of Heat-Sensitive Adhesive Sheet 3) The heat-sensitive adhesive composition 3 prepared above was coated on a polyester film for electric use (thickness 25 μm) corresponding to JEC 6147 standard of 120 ° C. (heat-resistant E class) by a bar. Using a coater, apply the coating so that the coating thickness after drying is 7 μm.
After drying for 0 second, heat-sensitive adhesive sheet 3 (finished thickness 3
2 μm).

[Comparative Example 1] (Preparation of heat-sensitive adhesive composition 4) The same operation as in Example 1 was carried out on the aqueous dispersion of solid plasticizer 3 prepared above to obtain a heat-sensitive adhesive composition. 4 and a heat-sensitive adhesive sheet 4 were obtained.

(1) Performance Evaluation Test (Electrical Insulation) The following items were measured for the heat-sensitive adhesive sheets 1 to 4 prepared above as evaluation indexes for the electrical insulation. Table 2 shows the results. Dielectric breakdown voltage Two specimens were superimposed on each other as a test specimen, and JIS
In accordance with C2110 “Testing method for dielectric strength of solid electrical insulating material”, a dielectric breakdown voltage (KV / 70 μm) was measured in the air (KV / 70 μm) using a disk electrode of φ25 mm (n = 4). The higher the dielectric breakdown voltage, the better the electrical insulation. Volume resistivity For each sample, the volume resistivity (Ω · cm) was measured (n = 2) according to JIS C2318 “Polyester film for electricity”. The electrode was an aluminum foil electrode. The higher the volume resistivity, the better the electrical insulation. Surface resistivity For each sample, the surface resistivity on the resin coating side was determined according to JIS K
The surface resistivity (Ω) was measured in accordance with 6911 “General Test Method for Thermosetting Plastics”. The electrode was an aluminum foil electrode. The higher the surface resistivity, the better the electrical insulation. Dielectric constant (ε) and dielectric tangent (tan δ) For each sample, the dielectric constant (ε) at a frequency of 1 kHz and the dielectric tangent (tan δ) were measured using a flat disk electrode in accordance with JIS C2318 “Polyester Film for Electricity”. Was measured. The lower the dielectric constant (ε) and the dielectric loss tangent (tan δ), the better the electrical insulation.

(2) Performance Evaluation Test (Adhesive Strength and Transparency) Separately from the heat-sensitive adhesive sheet produced above, a heat-sensitive adhesive composition prepared above was applied to a polyethylene terephthalate film whose surface was subjected to corona discharge treatment. 1 to 4 were coated using a bar coater so that the coating amount after drying was 10 g / m ^2, and dried at 40 ° C. for 3 minutes to form a heat-sensitive adhesive sheet for evaluation having a width of 25 mm and a length of 125 mm. Specimens were cut to size. The test piece was heated at 120 ° C. for 30 seconds to develop adhesiveness, and a glass plate [Iwaki Glass Co., Ltd.
(Micro S1ide G1ass, white-green polishing), and affixed by reciprocating once with a rubber roll under a load of 2 kg. This was left in an atmosphere of 23 ° C. and 50% RH, and one day, one month, and three months later, an adhesive strength test was performed. The adhesive strength test was performed using a tensile tester (manufactured by Orientec, Tensilon UCT-5T).
The adhesive force was measured at a pulling speed of 300 mm / min and a peel angle of 180 °. Further, the transparency was visually observed. Table 2 shows the results.

(3) Performance evaluation test (blocking resistance) Obtained by coating the base paper surface (back surface) of a piece of art paper with a bar coater so that the coating amount after drying is 10 g / m ^2. 4 heat-sensitive adhesive sheets for evaluation were overlapped so that the glossy surface (front surface) of the art paper and the surface (back surface) coated with the heat-sensitive adhesive composition were in contact with each other, and a load of 5000 gf / 9 cm ² was applied. After standing for 24 hours in an atmosphere of ° C., the evaluation of blocking resistance was performed according to the following criteria. Table 2 shows the results. 5: Peeled without resistance during peeling. 4: Peeling was performed with a slight sound when peeling. 3: Peeling was performed while making continuous sound during peeling. 2: Some paper fibers remained in the adhesive layer at the time of peeling. 1: The paper was torn by blocking.

[0061]

[Table 2]

From the results in Table 2, it is found that the heat-sensitive adhesive sheets of Examples 1 to 3 have a dielectric breakdown voltage as an index of electric insulation,
The volume resistivity, the surface resistivity, the dielectric constant (ε) and the dielectric loss tangent (tan δ) were all good. Example 1
It was found that the heat-sensitive adhesive sheets of Nos. To 3 have high adhesive strength and excellent blocking resistance. On the other hand, Comparative Example 1
The heat-sensitive pressure-sensitive adhesive sheet had a low adhesive strength and poor transparency and blocking resistance.

[0063]

The heat-sensitive adhesive composition for electronic materials of the present invention has excellent electric insulation and good blocking resistance by using at least one solid plasticizer having a melting point of less than 150 ° C. Furthermore, recrystallization of the solid plasticizer once melted can be prevented or delayed, and as a result, a heat-sensitive adhesive sheet or the like obtained using the heat-sensitive adhesive composition has excellent electrical insulation properties, and It can be dried by heating at a higher temperature, does not cause blocking even when stored for a long period of time, and can maintain high adhesive strength and transparency for a long period of time.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J004 AA04 AA05 AA06 AA07 AA09 AA10 AA14 AB03 CA02 CA03 CA04 CA05 CA06 CA07 CC02 CE01 DB01 FA05 FA08 4J040 CA011 CA081 CA091 DA041 DA061 DA071 DA181 DB061 DC031 DC031 H031 DF031B HC22 HD23 JA09 JA12 JB01 KA26 KA31 LA02 LA05 LA06 LA09 MA05 MA09 MA10 MA11 NA19 NA20 NA21

Claims (9)

[Claims] 1. A thermoplastic resin (A) and a solid plasticizer (B)
And (e) having the following excellent electrical properties (a) to (e). 6. A heat-sensitive adhesive composition for electronic materials, comprising: (B) Dielectric breakdown voltage is 11 (KV / 70 μm @ 25 ° C)
(B) Volume resistivity is 5 × 10 ¹⁷ (Ω · cm @ 25 ° C.)
(C) The surface resistivity is 3 × 10 ¹⁷ (Ω ＠ 25 ° C.) or more. (D) The dielectric constant (ε) is less than 4 (＠ 1 kHz). (E) The dielectric loss tangent (tan δ) is 0. .4 (＠ 1 kHz) 2. The solid plasticizer (B) comprises a phosphate compound (a), a phthalate compound (b), a hindered phenol compound (c), a triazole compound (d), and a hydroquinone compound. 2. A compound having at least one compound selected from the group consisting of compounds (e) and having a melting point of less than 150 ° C.
The heat-sensitive adhesive composition for electronic materials according to the above. 3. The electronic material according to claim 1, wherein the total content of the solid plasticizer (B) is 30 to 1000 parts by weight based on 100 parts by weight of the thermoplastic resin (A). Heat-sensitive adhesive composition for use. 4. The heat-sensitive adhesive composition for electronic materials according to claim 1, further comprising a tackifier (C). 5. The heat-sensitive adhesive composition for an electronic material according to claim 1, wherein the thermoplastic resin (A) is an aqueous composition dispersed in water. 6. A heat-sensitive adhesive for electronic materials, wherein the heat-sensitive adhesive composition for electronic materials according to claim 1 is used. 7. The method according to claim 6, wherein at least one surface of the substrate is provided.
A heat-sensitive adhesive laminate for electronic materials, which is coated with the heat-sensitive adhesive for electronic materials according to any one of the preceding claims. 8. The heat-sensitive adhesive laminate for an electronic material, wherein the laminate is a tape or a sheet.
The heat-sensitive adhesive laminate for an electronic material according to the above. 9. The method according to claim 6, wherein at least one surface of the substrate is provided.
A method for producing a heat-sensitive adhesive laminate for electronic materials, comprising forming a pressure-sensitive adhesive layer by coating the heat-sensitive adhesive for electronic materials as described in the above.