WO2015156254A1

WO2015156254A1 - Production method for thermally conductive pressure-sensitive adhesive laminated sheet, thermally conductive pressure-sensitive adhesive laminated sheet, and electronic device

Info

Publication number: WO2015156254A1
Application number: PCT/JP2015/060753
Authority: WO
Inventors: 明子北川; 拓朗熊本
Original assignee: 日本ゼオン株式会社
Priority date: 2014-04-07
Filing date: 2015-04-06
Publication date: 2015-10-15

Abstract

A production method for a thermally conductive pressure-sensitive adhesive laminated sheet (F) comprising a thermally conductive pressure-sensitive adhesive layer and a base material layer, said production method including: a polymer gel-containing dispersion liquid preparation step in which a crosslinked body-containing polymer composition (A) containing a thermally-conductive filler (C1) and a (meth) acrylate ester polymer (A0) is immersed in a solvent and agitated, and a polymer gel-containing dispersion liquid is prepared; a filtration step in which the polymer gel-containing dispersion liquid is filtered using a mesh having prescribed mesh openings and a filtrate is obtained; a coating step in which the filtrate is coated on at least one surface of the base material layer at a prescribed thickness; and a solvent removal step in which the solvent in the filtrate upon the base material layer is removed and the thermally conductive pressure-sensitive adhesive layer is obtained. The production method for the thermally conductive pressure-sensitive adhesive laminated sheet (F) is characterized by: the prescribed mesh openings being no more than 1.3 times the prescribed thickness; and the gel fraction of a post-filtration crosslinked body-containing polymer composition (H), obtained by drying the filtrate obtained by supplying the crosslinked body-containing polymer composition (A) to the polymer gel-containing dispersion liquid preparation step and the filtration step, being at least 75 mass%.

Description

Method for producing heat conductive pressure-sensitive adhesive laminate sheet, heat conductive pressure-sensitive adhesive laminate sheet, and electronic device

The present invention relates to a method for producing a heat conductive pressure-sensitive adhesive laminate sheet, a heat conductive pressure-sensitive adhesive laminate sheet obtained by the production method, and an electronic device including the heat conductive pressure-sensitive adhesive laminate sheet.

In recent years, electronic parts such as a plasma display panel (PDP), an integrated circuit (IC) chip and the like have increased in calorific value as their performance has increased. As a result, it is necessary to take countermeasures against functional failures due to temperature rise. In general, a method of dissipating heat by attaching a heat sink such as a metal heat sink, a heat radiating plate, or a heat radiating fin to a heat generator provided in an electronic component or the like is employed. In order to efficiently conduct heat conduction from the heating element to the radiator, a sheet-like member (thermally conductive sheet) having high thermal conductivity is sandwiched between the heating element and the radiator. .

The thermal conductive sheet as described above may be used by laminating a plurality of layers in order to provide a plurality of functions according to the application. For example, in Patent Document 1, a polyethylene terephthalate (PET) film or the like is provided on the surface opposite to the surface in contact with the adherend for the purpose of imparting strength capable of preventing the pressure-sensitive adhesive heat-dissipating sheet from tearing. It is disclosed that laminated reinforcing materials are used.
Hereinafter, a laminated sheet consisting of at least two layers provided with a base material layer on one surface and a heat conductive pressure-sensitive adhesive layer having heat conductivity and pressure sensitive adhesive on the other surface, or heat conduction as a front and back layer A laminated sheet comprising at least three layers including a pressure-sensitive adhesive layer and a base layer as an intermediate layer is referred to as a heat conductive pressure-sensitive adhesive laminated sheet. The heat conductive pressure-sensitive adhesive laminated sheet is used by attaching the surface on the heat conductive pressure-sensitive adhesive layer side to an adherend that is a heating element or a heat radiator.

When the heat conductive pressure-sensitive adhesive laminate sheet is attached to the adherend, air may be trapped and remain between the heat conductive pressure-sensitive adhesive laminate sheet and the adherend. Generation | occurrence | production of the remaining air (air pool) becomes a factor of adhesive force and a heat conductivity fall. Therefore, as a technique for eliminating such air entrapment, for example, Patent Document 2 discloses a base material, a decoration layer provided on one side of the base material, and a side provided on the other side of the base material. The pressure-sensitive adhesive sheet is provided with a plurality of through-holes penetrating from one surface to the other surface. A pressure-sensitive adhesive sheet having a pore density of 1 to 300 μm and a pore density of 30 to 50,000 per 100 cm ² is disclosed.

Patent Document 3 discloses an adhesive sheet that is used by being attached to a smooth adherend such as a window glass, and is formed on a sheet body made of a synthetic resin film and one surface of the sheet body. Provided with an adhesive layer to be attached to the adhesive body, and a slit formed so as to penetrate the sheet body and the adhesive layer, at least the whole of the slit does not overlap with a straight line connecting one end and the other end, An adhesive sheet is disclosed.

JP 2007-169416 A JP 2005-75953 A JP 2012-126855 A

According to the techniques disclosed in Patent Document 2 and Patent Document 3, the air between the sheet and the adherend is discharged through holes or slits that penetrate through the sheet in the thickness direction. Therefore, it is possible to suppress air from remaining between the sheet and the adherend.

However, when a through hole or a slit is provided in the sheet as in the prior art, the appearance of the sheet may be impaired. Further, since the heat generating body and the heat radiating body communicate with each other in the thickness direction through the air layer due to the through holes and slits, there is a possibility that the thermal conductivity is impaired. Furthermore, when the adhesive layer has self-adhesive properties, when the sheet is peeled off to reattach the adhesive sheet, part of the adhesive layer (sheet residue) may remain on the adherend, and the adhesive sheet must be reapplied. Sometimes became difficult.
In addition, in order to provide fine through holes and slits in the adhesive sheet, it is necessary to perform precision processing using a laser or cutter in addition to the sheet manufacturing process, which complicates the manufacturing process or upgrades the manufacturing equipment May be required.

Therefore, the present invention is a method for producing a heat conductive pressure-sensitive adhesive laminate sheet that can suppress air entrapment when attached to an adherend and is easy to reattach, and is manufactured with simple equipment. A heat-conductive pressure-sensitive adhesive laminate sheet, a heat-conductive pressure-sensitive adhesive laminate sheet obtained by the manufacturing method, and an electronic device including the heat-conductive pressure-sensitive adhesive laminate sheet Is an issue.

As a result of intensive studies in view of the above problems, the present inventors produced a heat conductive pressure-sensitive adhesive laminated sheet under predetermined conditions, and as a result, minute irregularities are formed on the surface of the heat conductive pressure-sensitive adhesive layer. As a result, it was found that air entrainment can be suppressed and re-sticking is facilitated.

That is, the 1st aspect of this invention is a manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet (F) provided with the heat conductive pressure-sensitive-adhesive layer and the base material layer, Comprising: A polymer gel-containing dispersion in which a crosslinked polymer-containing composition (A) containing C1) and a (meth) acrylic acid ester polymer (A0) is immersed in a solvent and stirred to prepare a polymer gel-containing dispersion. A liquid preparation step, a filtration step of filtering the polymer gel-containing dispersion with a mesh having a predetermined opening to obtain a filtrate, an application step of applying the filtrate to one surface of the base material layer to a predetermined thickness, A solvent removing step of removing a solvent in the filtrate on the material layer to obtain a heat conductive pressure-sensitive adhesive layer, and having a predetermined opening of 1.3 times or less of a predetermined thickness, Obtained by subjecting the molecular composition (A) to a polymer gel-containing dispersion preparation step and a filtration step The method for producing a heat conductive pressure-sensitive adhesive laminate sheet (F), wherein the gel fraction of the post-filtration crosslinked polymer composition (H) obtained by drying the liquid is 75% by mass or more. .

The 2nd aspect of this invention is a manufacturing method of the heat conductive pressure sensitive adhesive laminated sheet (F) provided with the heat conductive pressure sensitive adhesive layer and the base material layer, Comprising: Thermal conductive filler (C1) And a crosslinked polymer-containing polymer composition (A) containing the (meth) acrylic acid ester polymer (A0) is immersed in a solvent and stirred to prepare a polymer gel-containing dispersion. A process, a filtration step of filtering the polymer gel-containing dispersion with a mesh having a predetermined opening to obtain a filtrate, and a first application step of applying the filtrate to one surface of the base material layer to a predetermined thickness; A first solvent removing step of removing the solvent in the filtrate applied to one surface of the base material layer to obtain a heat conductive pressure-sensitive adhesive layer, and the filtrate on the other surface of the base material layer to a predetermined thickness The second coating process to be applied and the solvent in the filtrate applied to the other surface of the base material layer is removed to remove the thermal conductivity. A second solvent removing step for obtaining an adhesive layer, wherein the predetermined opening is 1.3 times or less of the predetermined thickness, and the crosslinked polymer-containing composition (A) is prepared as a polymer gel-containing dispersion The thermally conductive pressure-sensitive adhesive laminate is characterized in that the post-filtration crosslinked polymer composition (H) obtained by drying the filtrate obtained by the step and the filtration step has a gel fraction of 75% by mass or more. It is a manufacturing method of a sheet | seat (F).

In the present specification, the “thermal conductive filler” can be added to improve the thermal conductivity of the thermally conductive pressure-sensitive adhesive laminate sheet (F), and its thermal conductivity is 0.3 W / The filler which is m * K or more is meant. “(Meth) acryl” means “acryl and / or methacryl”.

In the first and second embodiments of the present invention, the crosslinked polymer composition (A) comprises a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), In the precursor composition containing the polyfunctional monomer (B1) and the thermally conductive filler (C1), at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1) and (meth) acrylic It is preferably obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from the acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1).

In the present specification, “polymerization reaction of (meth) acrylate monomer (α1)” means a polymerization reaction for obtaining a polymer containing a structural unit derived from (meth) acrylate monomer (α1). means. In addition, “(meth) acrylic acid ester polymer (A1) and / or (meth) acrylic acid ester monomer (α1) -derived polymer cross-linking reaction” means (meth) acrylic acid ester Cross-linking reaction between polymers (A1), cross-linking reaction between polymers containing structural units derived from (meth) acrylate monomer (α1), and (meth) acrylate polymer (A1) and ( Among crosslinking reactions with a polymer containing a structural unit derived from a (meth) acrylate monomer (α1), it means one or a plurality of crosslinking reactions.

In the first and second aspects of the present invention, the predetermined mesh opening is preferably 1000 μm or less.

A third aspect of the present invention is a heat conductive pressure-sensitive adhesive laminate sheet (F) obtained by the method for producing a heat conductive pressure-sensitive adhesive laminate sheet (F) according to the first or second aspect of the present invention. It is.

A fourth aspect of the present invention is an electronic device including the thermally conductive pressure-sensitive adhesive laminated sheet (F) according to the third aspect of the present invention.

According to the present invention, a method for producing a heat conductive pressure-sensitive adhesive laminated sheet that can suppress the biting of air when attached to an adherend and is easy to reattach, and is manufactured with simple equipment. The manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet which can be provided can be provided. Moreover, the electronic device provided with the heat conductive pressure sensitive adhesive laminated sheet obtained by this manufacturing method and this heat conductive pressure sensitive adhesive laminated sheet can be provided.

It is a flowchart explaining one Embodiment of the manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet which concerns on the 1st aspect of this invention. FIG. 3 is a diagram schematically showing the states of manufacturing steps S1 to S4 of a manufacturing method S10 of a heat conductive pressure-sensitive adhesive laminated sheet according to the first embodiment of the present invention. It is a flowchart explaining one Embodiment of the manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet which concerns on the 2nd aspect of this invention. FIG. 7 is a diagram schematically showing the states of manufacturing steps S11 to S16 of a manufacturing method S20 of a heat conductive pressure-sensitive adhesive laminated sheet according to a second embodiment of the present invention. It is the figure which showed schematically the usage example of the heat conductive pressure-sensitive-adhesive laminated sheet.

Hereinafter, embodiments of the present invention will be described. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below. Unless otherwise specified, the notation “A to B” for the numerical values A and B means “A to B”. In this notation, when a unit is attached to only the numerical value B, the unit is also applied to the numerical value A.

1. Manufacturing method (I) of heat conductive pressure-sensitive adhesive laminated sheet (F)
Hereinafter, the manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet (F) which concerns on the 1st aspect of this invention is demonstrated. FIG. 1 is a flowchart for explaining a production method S10 (hereinafter sometimes abbreviated as “this production method S10”) of a heat conductive pressure-sensitive adhesive laminated sheet (F) according to the first embodiment of the present invention. is there. As shown in FIG. 1, this manufacturing method S10 includes a polymer gel-containing dispersion preparation step S1, a filtration step S2, a coating step S3, and a solvent removal step S4. FIG. 2 is a diagram schematically showing the states of steps S1 to S4 of the manufacturing method S10. As shown in S4 at the bottom of FIG. 2, the heat conductive pressure-sensitive adhesive laminated sheet (F) 10 produced by this production method S10 is composed of a base material layer 8 and a heat conductive pressure-sensitive adhesive layer having irregularities on the surface. 9. Hereinafter, each step will be described.

1.1. Polymer gel-containing dispersion preparation step S1
In the polymer gel-containing dispersion preparation step S1, the crosslinked polymer composition (A) containing the thermally conductive filler (C1) and the (meth) acrylate polymer (A0) is immersed in a solvent and stirred. In this step, a polymer gel-containing dispersion is prepared.

<(Meth) acrylic acid ester polymer (A0)>
In the present invention, the (meth) acrylic acid ester polymer (A0) is a polymer having a (meth) acrylic acid ester monomer unit as a main component.
The “main component” means a component that is contained by 50% by weight or more.

The (meth) acrylic acid ester polymer (A0) includes a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), a polyfunctional monomer (B1), In the precursor composition containing the thermally conductive filler (C1), at least the polymerization reaction of the (meth) acrylate monomer (α1), the (meth) acrylate polymer (A1) and / or The polymer component of the crosslinked polymer composition (A) obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from the (meth) acrylate monomer (α1) is preferable.

<Thermal conductive filler (C1)>
In the present invention, the crosslinked polymer-containing composition (A) contains a heat conductive filler (C1). The thermally conductive filler (C1) used in the present invention can improve the thermal conductivity of the thermally conductive pressure-sensitive adhesive layer by adding it, and the inorganic compound has a thermal conductivity of 0.3 W / m · K or more. It is.

Specific examples of the thermally conductive filler (C1) include metal hydroxides such as aluminum hydroxide, gallium hydroxide, indium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide; aluminum oxide ( Alumina), metal oxides such as magnesium oxide and zinc oxide; metal carbonates such as calcium carbonate and aluminum carbonate; metal nitrides such as boron nitride and aluminum nitride; zinc borate hydrate; kaolin clay; calcium aluminate water Examples thereof include: Japanese; Dosonite; Silica; Expanded graphite powder, artificial graphite, carbon black, carbon fiber, and other carbon-containing conductive fillers. Of these, metal hydroxides and metal oxides are preferred, metal hydroxides are more preferred, aluminum hydroxide and aluminum oxide (alumina) are more preferred, and aluminum hydroxide is even more preferred. A heat conductive filler (C1) may be used individually by 1 type, and may use 2 or more types together.

The amount of the thermally conductive filler (C1) contained in the cross-linked polymer composition (A) is 150 parts by mass or more and 1500 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A0). Preferably, it is 200 to 1300 parts by mass, more preferably 350 to 1000 parts by mass. By making content of a heat conductive filler (C1) more than the said minimum, it becomes easy to exhibit the effect which improves the heat conductivity of a heat conductive pressure-sensitive-adhesive layer. On the other hand, the hardness of the crosslinked polymer composition (A) and the crosslinked crosslinked polymer composition (H) is prevented from increasing by setting the content of the heat conductive filler (C1) to the upper limit or less. It can prevent, and it can prevent that the air venting property of a heat conductive pressure-sensitive-adhesive laminated sheet (F) falls.

The average particle diameter of the heat conductive filler (C1) is preferably 0.5 μm or more and 15 μm or less, and more preferably 5 μm or more and 12 μm or less. The BET specific surface area of the heat conductive filler (C1) is preferably 0.3 m ² / g or more and 10 m ² / g or less, and more preferably 0.5 m ² / g or more and 2 m ² / g or less. preferable. Even if it increases content of a heat conductive filler (C1) by making the average particle diameter and BET specific surface area of a heat conductive filler (C1) into the said range, bridge | crosslinking containing polymer composition (A) and filtration The post-crosslinked polymer composition (H) can be made difficult to become brittle, and the workability is excellent.

In the present invention, “BET specific surface area” means that measured by the following method. First, a mixed gas of nitrogen and helium is introduced into a BET specific surface area measuring apparatus, and a sample cell containing a sample (an object to be measured for BET specific surface area) is immersed in liquid nitrogen to adsorb nitrogen gas to the sample surface. After reaching adsorption equilibrium, the sample cell is placed in a water bath and warmed to room temperature, and nitrogen adhering to the sample is desorbed. Since the mixing ratio of the gas before and after passing through the sample cell changes during the adsorption and desorption of nitrogen gas, this change is detected by a thermal conductivity detector (TCD) using a gas with a constant mixing ratio of nitrogen and helium as a control. Then, the adsorption amount and desorption amount of nitrogen gas are obtained. Before the measurement, a unit amount of nitrogen gas is introduced into the apparatus for calibration, and the surface area value corresponding to the value detected by TCD is obtained to obtain the surface area of the sample. Then, the BET specific surface area can be determined by dividing the determined surface area by the mass of the sample.

In obtaining the cross-linked polymer composition (A), in addition to the (meth) acrylic acid ester polymer (A0) and the heat conductive filler (C1), various known additions are added within a range that satisfies the required performance. An agent may be introduced.
Known additives include, for example, flame retardants such as phosphate esters; foaming agents (including foaming aids); glass fibers; external cross-linking agents; pigments; fillers such as titanium dioxide; nanomaterials such as fullerenes and carbon nanotubes. Particles; Polyphenol-based, hydroquinone-based, hindered amine-based antioxidants; and the like.

The crosslinked polymer-containing composition (A) comprises a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), a polyfunctional monomer (B1), a heat In the precursor composition containing the conductive filler (C1), at least the polymerization reaction of the (meth) acrylate monomer (α1), the (meth) acrylate polymer (A1) and / or (meta) And a crosslinking reaction of a polymer containing a structural unit derived from an acrylate monomer (α1). From the component containing the (meth) acrylic acid ester polymer (A1), the (meth) acrylic acid ester monomer (α1), and the polyfunctional monomer (B1) by the polymerization reaction and the crosslinking reaction. A (meth) acrylic acid ester polymer (A0) as a polymer component of the crosslinked polymer-containing composition (A) is preferably obtained. The crosslinked polymer-containing composition (A) includes a (meth) acrylic acid ester polymer (A0) as a polymer component and a thermally conductive filler (C1). The (meth) acrylic acid ester polymer (A0) and the thermally conductive filler (C1) may be bonded at least partially.

<Precursor composition>
The precursor composition comprises a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), a polyfunctional monomer (B1), and a thermally conductive filler (C1). ) And. Moreover, as described later, the precursor composition may contain a polymerization initiator (D1) and a phosphate ester (E1). In addition, when obtaining a crosslinked-containing polymer composition (A) using a precursor composition, the polymerization reaction and crosslinking reaction of a (meth) acrylic acid ester monomer ((alpha) 1) are performed at least. By performing the polymerization reaction and the crosslinking reaction, the polymer containing the structural unit derived from the (meth) acrylate monomer (α1) is mixed with the component of the (meth) acrylate polymer (A1) and / or one. Partially combine.
In the present invention, the (meth) acrylic acid ester polymer (A1), the (meth) acrylic acid ester monomer (α1), and the polyfunctional monomer (B1) are collectively referred to as “(meta ) Acrylic resin precursor (P1) ”.

In the present invention, the proportion of the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer (α1) used is (mass) acrylic resin precursor (P1) being 100% by mass, The meth) acrylate polymer (A1) is preferably 5% by mass or more and 70% by mass or less, and the (meth) acrylic acid ester monomer (α1) is preferably 29.9% by mass or more and 94.9% by mass or less. The (meth) acrylic acid ester polymer (A1) is 5% by mass or more and 60% by mass or less, and the (meth) acrylic acid ester monomer (α1) is 39.8% by mass or more and 94.8% by mass or less. Is more preferable, the (meth) acrylic acid ester polymer (A1) is 10% by mass to 50% by mass, and the (meth) acrylic acid ester monomer (α1) is 49.7% by mass to 89.7% by mass. so Rukoto is more preferable. By making the use ratio of the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer (α1) within the above range, the precursor composition can be easily molded.

((Meth) acrylic acid ester polymer (A1))
The (meth) acrylic acid ester polymer (A1) that can be used in the present invention is not particularly limited, but the (meth) acrylic acid ester monomer that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the unit (a1) and the monomer unit (a2) having an organic acid group.

The (meth) acrylate monomer (a1m) that gives the unit (a1) of the (meth) acrylate monomer is not particularly limited. For example, ethyl acrylate (the glass transition temperature of the homopolymer is -24 ° C), n-propyl acrylate (-37 ° C), n-butyl acrylate (-54 ° C), sec-butyl acrylate (-22 ° C), n-heptyl acrylate (-60) ° C), n-hexyl acrylate (-61 ° C), n-octyl acrylate (-65 ° C), 2-ethylhexyl acrylate (-50 ° C), n-octyl methacrylate (-25 ° C) A (meth) acrylic acid alkyl ester that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, such as n-decyl methacrylate (-49 ° C.); 2-methoxyethyl acrylate The glass transition temperature is −50 ° C.), 3-methoxypropyl acrylate (-75 ° C.), 3-methoxybutyl acrylate (-56 ° C.), ethoxymethyl acrylate (−50 ° C.), etc. And (meth) acrylic acid alkoxyalkyl esters that form a homopolymer of 20 ° C. or lower. Among them, (meth) acrylic acid alkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower, (meth) acrylic acid alkoxyalkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower (Meth) acrylic acid alkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower is more preferable, and 2-ethylhexyl acrylate is more preferable.

These (meth) acrylic acid ester monomers (a1m) may be used alone or in combination of two or more.

In the (meth) acrylic acid ester monomer (a1m), the monomer unit (a1) derived therefrom is preferably 80% by mass or more and 99.9% by mass in the (meth) acrylic acid ester polymer (A1). Hereinafter, it is used for polymerization in such an amount that it is more preferably 85 mass% or more and 99.5 mass% or less. When the amount of the (meth) acrylic acid ester monomer (a1m) is within the above range, the viscosity of the polymerization system at the time of polymerization can be easily maintained within an appropriate range.

Next, the monomer unit (a2) having an organic acid group will be described. The monomer (a2m) that gives the monomer unit (a2) having an organic acid group is not particularly limited, but representative examples thereof include organic acid groups such as a carboxyl group, an acid anhydride group, and a sulfonic acid group. The monomer which has can be mentioned. In addition to these, monomers containing sulfenic acid groups, sulfinic acid groups, phosphoric acid groups, and the like can also be used.

Specific examples of the monomer having a carboxyl group include, for example, α, β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and α, β such as itaconic acid, maleic acid, and fumaric acid. In addition to β-ethylenically unsaturated polyvalent carboxylic acid, α, β-ethylenically unsaturated polyvalent carboxylic acid partial esters such as monomethyl itaconate, monobutyl maleate and monopropyl fumarate can be exemplified. Moreover, what has group which can be induced | guided | derived to a carboxyl group by hydrolysis etc., such as maleic anhydride and itaconic anhydride, can be used similarly.

Specific examples of the monomer having a sulfonic acid group include allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid, α, β-unsaturated sulfonic acid such as acrylamide-2-methylpropane sulfonic acid, And salts thereof.

As the monomer (a2m), among the monomers having an organic acid group exemplified above, a monomer having a carboxyl group is more preferable, and an α, β-ethylenically unsaturated monocarboxylic acid is more preferable. (Meth) acrylic acid is particularly preferred. These monomers are industrially inexpensive and can be easily obtained, have good copolymerizability with other monomer components, and are preferable in terms of productivity. In addition, a monomer (a2m) may be used individually by 1 type, and may use 2 or more types together.

In the monomer (a2m) having an organic acid group, the monomer unit (a2) derived from the monomer unit (a2) is preferably 0.1% by mass or more and 20% by mass or less in the (meth) acrylic acid ester polymer (A1). More preferably, it is used for the polymerization in such an amount that it is 0.5 to 15% by mass. When the usage-amount of the monomer (a2m) which has an organic acid group exists in the said range, it will become easy to maintain the viscosity of the polymerization system at the time of superposition | polymerization in an appropriate range.

The monomer unit (a2) having an organic acid group is introduced into the (meth) acrylic acid ester polymer (A1) by polymerization of the monomer (a2m) having an organic acid group as described above. Although it is simple and preferable to perform, an organic acid group may be introduced by a known polymer reaction after the (meth) acrylic acid ester polymer (A1) is formed.

Further, the (meth) acrylic acid ester polymer (A1) may contain a monomer unit (a3) derived from a monomer (a3m) having a functional group other than an organic acid group. Examples of the functional group other than the organic acid group include a hydroxyl group, an amino group, an amide group, an epoxy group, and a mercapto group.

Examples of the monomer having a hydroxyl group include (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxyethyl and (meth) acrylic acid 3-hydroxypropyl.

Examples of the monomer having an amino group include N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and aminostyrene.

Examples of monomers having an amide group include α, β-ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, and N, N-dimethylacrylamide. Can be mentioned.

Examples of the monomer having an epoxy group include glycidyl (meth) acrylate and allyl glycidyl ether.

As the monomer (a3m) having a functional group other than the organic acid group, one type may be used alone, or two or more types may be used in combination.

In the monomer (a3m) having a functional group other than these organic acid groups, the monomer unit (a3) derived therefrom is 10% by mass or less in the (meth) acrylate polymer (A1). It is preferable to use it for polymerization in such an amount. By using the monomer (a3m) of 10% by mass or less, it becomes easy to keep the viscosity of the polymerization system during polymerization in an appropriate range.

The (meth) acrylic acid ester polymer (A1) has a (meth) acrylic acid ester monomer unit (a1) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, and an organic acid group. In addition to the monomer unit (a2) and the monomer unit (a3) having a functional group other than an organic acid group, a monomer derived from the monomer (a4m) copolymerizable with the above-described monomer. The monomer unit (a4) may be contained.

The monomer (a4m) is not particularly limited, and specific examples thereof include (meth) acrylate monomers other than the (meth) acrylate monomer (a1m), α, β-ethylenic monomers. Saturated polyvalent carboxylic acid complete ester, alkenyl aromatic monomer, vinyl cyanide monomer, carboxylic acid unsaturated alcohol ester, olefin monomer and the like can be mentioned.

Specific examples of the (meth) acrylate monomer other than the (meth) acrylate monomer (a1m) include methyl acrylate (homopolymer having a glass transition temperature of 10 ° C.), methyl methacrylate. (105 ° C.), ethyl methacrylate (63 ° C.), n-propyl methacrylate (25 ° C.), n-butyl methacrylate (20 ° C.), and the like.

Specific examples of the α, β-ethylenically unsaturated polyvalent carboxylic acid complete ester include dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, dimethyl itaconate and the like.

Specific examples of the alkenyl aromatic monomer include styrene, α-methylstyrene, methyl α-methylstyrene, vinyltoluene and the like.

Specific examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like.

Specific examples of the carboxylic acid unsaturated alcohol ester monomer include vinyl acetate.

Specific examples of the olefin monomer include ethylene, propylene, butene, pentene and the like.

As the monomer (a4m), one type may be used alone, or two or more types may be used in combination.

In the monomer (a4m), the amount of the monomer unit (a4) derived therefrom is preferably 10% by mass or less, more preferably 5% by mass or less in the (meth) acrylate polymer (A1). It is subjected to polymerization in such an amount.

The (meth) acrylic acid ester polymer (A1) has the above-mentioned (meth) acrylic acid ester monomer (a1m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, and an organic acid group. Monomer (a2m), a monomer containing a functional group other than an organic acid group (a3m) used as necessary, and a monomer copolymerizable with these monomers used as needed It can be particularly suitably obtained by copolymerizing the monomer (a4m).

The polymerization method for obtaining the (meth) acrylic acid ester polymer (A1) is not particularly limited, and may be any of solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, and the like, or any other method. . However, among these polymerization methods, solution polymerization is preferable, and among them, solution polymerization using a carboxylic acid ester such as ethyl acetate or ethyl lactate or an aromatic solvent such as benzene, toluene or xylene is more preferable. In the polymerization, the monomer may be added in portions to the polymerization reaction vessel, but it is preferable to add the whole amount at once. The method for initiating the polymerization is not particularly limited, but it is preferable to use a thermal polymerization initiator as the polymerization initiator. The thermal polymerization initiator is not particularly limited, and for example, a peroxide polymerization initiator or an azo compound polymerization initiator can be used.

Peroxide polymerization initiators include hydroperoxides such as t-butyl hydroperoxide, peroxides such as benzoyl peroxide and cyclohexanone peroxide, and persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate. Can be mentioned. These peroxides can also be used as a redox catalyst in appropriate combination with a reducing agent.

As azo compound polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) And so on.

Although the usage-amount of a polymerization initiator is not specifically limited, It is preferable that it is the range of 0.01 to 50 mass parts with respect to 100 mass parts of monomers.

Other polymerization conditions (polymerization temperature, pressure, stirring conditions, etc.) of these monomers are not particularly limited.

After completion of the polymerization reaction, the obtained polymer is separated from the polymerization medium if necessary. The separation method is not particularly limited. For example, in the case of solution polymerization, the (meth) acrylic acid ester polymer (A1) can be obtained by placing the polymerization solution under reduced pressure and distilling off the polymerization solvent.

The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1) is measured by gel permeation chromatography (GPC method) and may be in the range of 1,000 to 1,000,000 in terms of standard polystyrene. Preferably, it is in the range of 100,000 or more and 500,000 or less. The weight average molecular weight of the (meth) acrylic acid ester polymer (A1) can be controlled by appropriately adjusting the amount of the polymerization initiator used in the polymerization and the amount of the chain transfer agent.

((Meth) acrylic acid ester monomer (α1))
The (meth) acrylate monomer (α1) is not particularly limited as long as it contains the (meth) acrylate monomer, but forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the (meth) acrylic acid ester monomer (a5m).

As an example of a (meth) acrylate monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, it is used for the synthesis of a (meth) acrylate polymer (A1) (meth) ) The same (meth) acrylate monomer as the acrylate monomer (a1m) can be mentioned. A (meth) acrylic acid ester monomer (a5m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the (meth) acrylate monomer (a5m) in the (meth) acrylate monomer (α1) is preferably 50% by mass to 100% by mass, more preferably 75% by mass to 100% by mass. It is as follows. By making the ratio of the (meth) acrylic acid ester monomer (a5m) in the (meth) acrylic acid ester monomer (α1) within the above range, the heat conductive feeling excellent in heat conductive pressure-sensitive adhesiveness and flexibility. It becomes easy to obtain a pressure bonding layer.

The (meth) acrylic acid ester monomer (α1) is a (meth) acrylic acid ester monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is good also as a mixture of the monomer (a6m) which has a polymerizable organic acid group.

Examples of the monomer (a6m) include monomers having an organic acid group similar to those exemplified as the monomer (a2m) used for the synthesis of the (meth) acrylic acid ester polymer (A1). be able to. A monomer (a6m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) is preferably 30% by mass or less, and more preferably 10% by mass or less. By making the ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) within the above range, it is easy to obtain a heat conductive pressure-sensitive adhesive layer excellent in heat conductive pressure-sensitive adhesiveness and flexibility. Become.

The (meth) acrylic acid ester monomer (α1), in addition to the (meth) acrylic acid ester monomer (a5m) and the monomer (a6m) having an organic acid group that can be optionally copolymerized, It is good also as a mixture containing the monomer (a7m) copolymerizable with these.

Examples of the monomer (a7m) include the monomer (a3m) used for the synthesis of the (meth) acrylic acid ester polymer (A1) and the same amount as those exemplified as the monomer (a4m). The body can be mentioned. A monomer (a7m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the monomer (a7m) in the (meth) acrylic acid ester monomer (α1) is preferably 20% by mass or less, and more preferably 15% by mass or less.

(Polyfunctional monomer (B1))
In the present invention, the precursor composition contains the polyfunctional monomer (B1) as an essential component. Usually, at the time of polymerization such as radical thermal polymerization, a certain degree of crosslinking reaction proceeds without using a polyfunctional monomer. However, it is possible to reliably form a desired amount of cross-linked structure, to produce a polymer gel having a particle size smaller than the mesh opening, and to form a pressure-sensitive adhesive layer having minute irregularities, so that a polyfunctional monomer It is preferable that a body (B1) is included.

As the polyfunctional monomer (B1) that can be used in the present invention, a monomer that can be copolymerized with the monomer contained in the (meth) acrylic acid ester monomer (α1) is used. Further, the polyfunctional monomer (B1) has a plurality of polymerizable unsaturated bonds, and preferably has the unsaturated bond at the terminal. By using such a polyfunctional monomer (B1), intramolecular and / or intermolecular crosslinking is introduced into the copolymer, and the crosslinked polymer composition (A) and the crosslinked polymer after filtration are introduced. It becomes easy to make the gel fraction of a composition (H) into a desired range.

Examples of the polyfunctional monomer (B1) include 1,6-hexanediol di (meth) acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditri Multifunctional (meth) acrylates such as methylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 2,4-bis (to Other substituted triazines, such as chloromethyl) -6-p-methoxystyrene-5-triazine, etc. monoethylenically unsaturated aromatic ketones such as 4-acryloxy benzophenone can be used. Polyfunctional (meth) acrylates are preferred, and pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate are more preferred. A polyfunctional monomer (B1) may be used individually by 1 type, and may use 2 or more types together.

The amount of the polyfunctional monomer (B1) used is preferably 0.1% by mass or more and 20% by mass or less, with the (meth) acrylic resin precursor (P1) being 100% by mass, and 0.2% by mass. % To 10% by mass, more preferably 0.3% to 8% by mass. By making the amount of the polyfunctional monomer (B1) used within the above range, a polymer gel having a particle size smaller than the mesh opening is produced, and a heat conductive pressure-sensitive adhesive layer having minute irregularities is formed. It becomes easy to do. Moreover, it becomes easy to give an appropriate cohesion force to a heat conductive pressure-sensitive-adhesive layer.

<Thermal conductive filler (C1)>
Since the heat conductive filler (C1) has already been described above, description thereof is omitted here.

It is preferable that the usage-amount of a heat conductive filler (C1) is 150 to 1500 mass parts with respect to 100 mass parts of (meth) acrylic resin precursors (P1), and is 200 to 1300 mass parts. It is more preferable that it is 350 mass parts or more and 1000 mass parts or less. By making the usage-amount of a heat conductive filler (C1) more than the said minimum, it becomes easy to exhibit the effect which improves the heat conductivity of a heat conductive pressure-sensitive-adhesive layer. On the other hand, by making the usage-amount of a heat conductive filler (C1) below the said upper limit, it prevents that the hardness of bridge | crosslinking body polymer composition (A) and the crosslinked body polymer composition (H) after filtration raises. It can prevent, and it can prevent that the air venting property of a heat conductive pressure-sensitive-adhesive laminated sheet (F) falls.

(Polymerization initiator (D1))
When obtaining the crosslinked polymer-containing composition (A), the components contained in the (meth) acrylic resin precursor (P1) are polymerized as described above. In order to accelerate the polymerization reaction, it is preferable to use a polymerization initiator (D1). Examples of the polymerization initiator (D1) include a photopolymerization initiator, an azo thermal polymerization initiator, and an organic peroxide thermal polymerization initiator. However, it is preferable to use an organic peroxide thermal polymerization initiator from the viewpoint of imparting strong adhesive force to the obtained heat conductive pressure-sensitive adhesive layer.

As the photopolymerization initiator, various known photopolymerization initiators can be used. Of these, acylphosphine oxide compounds are preferred. Preferred examples of the acylphosphine oxide compound that is a photopolymerization initiator include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

As the azo-based thermal polymerization initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) ) And the like.

Examples of the organic peroxide thermal polymerization initiator include hydroperoxides such as t-butyl hydroperoxide, benzoyl peroxide, cyclohexanone peroxide, 1,6-bis (t-butylperoxycarbonyloxy) hexane, 1,1-bis ( and a peroxide such as t-butylperoxy) -3,3,5-trimethylcyclohexanone. However, those that do not release volatile substances that cause odor during thermal decomposition are preferred. Among organic peroxide thermal polymerization initiators, those having a 1-minute half-life temperature of 100 ° C. or more and 170 ° C. or less are preferable.

The amount of the polymerization initiator (D1) used is preferably 0.01 parts by mass or more and 10 parts by mass or less, and 0.1 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic resin precursor (P1). It is more preferably 5 parts by mass or less, and further preferably 0.3 parts by mass or more and 2 parts by mass or less.
By making the usage-amount of a polymerization initiator (D1) into the said range, it becomes easy to make the polymerization conversion rate of a (meth) acrylic acid ester monomer ((alpha) 1) into an appropriate range, and a crosslinked polymer composition (A) It is easy to prevent the monomer odor from remaining on the surface, and the workability in the subsequent steps is excellent.
The polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is preferably 95% by mass or more. If the polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is 95% by mass or more, it becomes easy to prevent the monomer odor from remaining in the crosslinked polymer-containing composition (A), and the subsequent steps Excellent workability.

<Phosphate ester (E1)>
The precursor composition may contain a phosphate ester (E1). By containing the phosphate ester (E1), it becomes easy to impart excellent flame retardancy to the heat conductive pressure-sensitive adhesive layer.

The phosphate ester (E1) used in the present invention preferably has a viscosity at 25 ° C. of 3000 mPa · s or more. By setting the viscosity of the phosphate ester (E1) in the above range, the precursor composition can be easily molded when the precursor composition is molded into a desired shape and then subjected to polymerization and crosslinking reaction. In the present invention, the “viscosity” of the phosphate ester (E1) means the viscosity measured by the method described below.

(Method for measuring viscosity of phosphate ester (E1))
The viscosity of the phosphoric ester (E1) is measured using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) according to the following procedure.
(1) Weigh 300 ml of phosphate ester in a normal temperature environment and place it in a 500 ml container.
(2) Stirring rotor No. Select one from 1, 2, 3, 4, 5, 6, and 7 and attach to the viscometer.
(3) The container containing the phosphate ester is placed on the viscometer, and the rotor is submerged in the condensed phosphate ester in the container. At this time, the dent which becomes a mark of a rotor sinks so that it may just come to the liquid interface of phosphate ester.
(4) The rotation speed is selected from 20, 10, 4, and 2.
(5) Turn on the stirring switch and read the value after 1 minute.
(6) The value obtained by multiplying the read numerical value by the coefficient A is the viscosity [mPa · s].
The coefficient A is the selected rotor No. as shown in Table 1 below. And the number of revolutions.

Moreover, it is preferable that the phosphate ester (E1) used in the present invention is always a liquid in a temperature range of 15 ° C. or more and 100 ° C. or less under atmospheric pressure. If the phosphate ester (E1) is a liquid when mixed, the workability is good and it is easy to obtain the crosslinked polymer-containing composition (A). When the crosslinked polymer composition (A) containing the phosphate ester (E1) is obtained, it is preferable to mix each substance constituting the precursor composition in an environment of 15 ° C. or higher and 100 ° C. or lower. By setting the temperature at the time of mixing in the above range, the temperature becomes equal to or higher than the glass transition temperature of the precursor composition, and it is easy to prevent volatilization or polymerization reaction of monomers and the like contained in the precursor composition. , Environmental performance and workability can be improved.

In the present invention, either a condensed phosphate ester or a non-condensed phosphate ester can be used as the phosphate ester (E1). As used herein, “condensed phosphate ester” means one having a plurality of phosphate ester moieties in one molecule, and “non-condensed phosphate ester” means one phosphate ester moiety in one molecule. It means something that exists only. Specific examples of the phosphate ester (E1) that satisfies the conditions described so far are listed below.

Specific examples of the condensed phosphate ester include aromatic condensed phosphate esters such as 1,3-phenylene bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), resorcinol bis (diphenyl phosphate); polyoxyalkylene bisdichloroalkyl And halogen-containing condensed phosphates such as phosphates; non-aromatic non-halogen-based condensed phosphates; Of these, aromatic condensed phosphates are preferred because of their relatively low specific gravity, no risk of releasing harmful substances (such as halogens), and availability, and 1,3-phenylenebis (diphenyl phosphate). ), Bisphenol A bis (diphenyl phosphate) is more preferred.

Specific examples of the non-condensed phosphate ester include aromatics such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-xylenyl phosphate, 2-ethylhexyl diphenyl phosphate And phosphoric acid esters; halogen-containing phosphoric acid esters such as tris (β-chloropropyl) phosphate, trisdichloropropylphosphate, tris (tribromoneopentyl) phosphate; Of these, aromatic phosphates are preferred because no harmful substances (such as halogen) are generated.

As the phosphate ester (E1), one type may be used alone, or two or more types may be used in combination.

When the phosphate ester (E1) is used for the heat conductive pressure-sensitive adhesive layer, the amount is preferably 120 parts by mass or less, with the total of the (meth) acrylic resin precursor (P1) being 100 parts by mass, It is more preferable that the amount is not more than part by mass. By making content of phosphate ester (E1) into the said range, it becomes easy to maintain the pressure sensitive adhesiveness of a heat conductive pressure sensitive adhesive layer.

(Other additives)
In the precursor composition, various known additives are added in addition to the substances described so far, within a range that can satisfy the performance such as thermal conductivity and pressure-sensitive adhesiveness required for the heat-conductive pressure-sensitive adhesive layer. be able to.
Known additives include foaming agents (including foaming aids); heat conductive fillers such as metal hydroxides and metal salt hydrates excluding the above-mentioned heat conductive filler (C1); glass fibers; Thermally conductive inorganic compounds excluding the above-mentioned thermally conductive filler (C1) such as PITCH-based carbon fibers; external cross-linking agents; pigments; fillers such as titanium dioxide; nanoparticles such as fullerenes and carbon nanotubes; polyphenols and hydroquinones And antioxidants such as hindered amines.

<Cross-linked polymer composition (A)>
The crosslinked polymer-containing composition (A) contains a heat conductive filler (C1) and a (meth) acrylic acid ester polymer (A0).
The crosslinked polymer-containing composition (A) is prepared by mixing the above-mentioned substances constituting the precursor composition to prepare the precursor composition, and then at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1). And a crosslinking reaction of a polymer containing a structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1). Here, it is preferable that the “crosslinked polymer composition (A)” includes a non-crosslinked component such as a linear polymer or a branched polymer that is not crosslinked and is dissolved in a solvent.

The gel fraction of the crosslinked polymer composition (A) is preferably 75% by mass or more, and more preferably 85% by mass or more. When the gel fraction is 75% by mass or more, a polymer gel having a particle size equal to or smaller than the mesh opening is prepared, and a post-filtration crosslinked polymer composition (H) having a desired gel fraction is prepared. This makes it easier to produce a heat conductive pressure-sensitive adhesive layer having minute irregularities. On the other hand, the gel fraction of the crosslinked polymer-containing composition (A) is preferably 99% by mass or less, and more preferably 95% by mass or less. When the gel fraction is 99% by mass or less, in the heat conductive pressure-sensitive adhesive layer, in the heat conductive pressure-sensitive adhesive sheet, the non-crosslinking component serves to connect the cross-linking components together. It is possible to effectively prevent the heat conductive pressure-sensitive adhesive layer from peeling off from the material layer, and it is possible to increase the pressure-sensitive adhesive property of the heat conductive pressure-sensitive adhesive laminate sheet (F).
The gel fraction in the present invention means, for example, that 0.2 g of a dry sample of the crosslinked polymer composition (A) is wrapped with a wire mesh having an opening of 234 μm, immersed in 100 ml of ethyl acetate for 23 hours, and filtered by taking it out. After that, the taken-out wire mesh is dried at 50 ° C. for 1 hour, and the dry mass of the insoluble matter remaining on the wire mesh having a mesh opening of 234 μm is measured.
Gel fraction (mass%) = ((dry mass of insoluble matter remaining in wire mesh with opening of 234 μm after immersion in ethyl acetate) / (dry mass of sample before immersion in ethyl acetate)) × 100

In the polymer gel-containing dispersion preparation step S1, heating is preferably performed when the polymerization and the crosslinking reaction are performed. For the heating, for example, hot air, an electric heater, infrared rays, or the like can be used. The heating temperature at this time is preferably a temperature at which the polymerization initiator is efficiently decomposed and the polymerization of the (meth) acrylate monomer (α1) proceeds. The temperature range varies depending on the type of polymerization initiator used, but is preferably 100 ° C. or higher and 200 ° C. or lower, and more preferably 120 ° C. or higher and 180 ° C. or lower.

From the viewpoint of uniformly heating the entire precursor composition in a short time and producing a homogeneous crosslinked polymer-containing composition (A), it is preferable to heat the precursor composition after forming it into a sheet. Here, the method for forming the precursor composition into a sheet is not particularly limited. As a suitable method, for example, the above precursor composition is sandwiched between arbitrary substrates to form a sheet, and the precursor composition thus sandwiched is further pressed between two rolls. The method of shape | molding into a sheet form by doing and the method of extruding the said precursor composition using an extruder, and controlling the thickness through a die | dye in that case, etc. are mentioned.
A sheet-like crosslinked polymer composition (A) can be obtained by forming the precursor composition into a sheet and then performing polymerization and a crosslinking reaction. It is preferable from the viewpoint of productivity that the crosslinked polymer composition (A) is in the form of a sheet because the amount of the crosslinked polymer composition (A) to be immersed in a predetermined amount of solvent can be easily adjusted.

The shape and size of the crosslinked polymer composition (A) when immersed in a solvent are not particularly limited as long as it does not prevent the crosslinked polymer composition (A) from being immersed and stirred in a solvent. Therefore, for example, the end portion of the product to be discarded in the manufacturing process of the heat conductive pressure sensitive adhesive sheet using the precursor composition as a raw material, or a torn used heat conductive pressure sensitive adhesive sheet as a material Can be used as Therefore, the manufacturing method of the heat conductive pressure-sensitive-adhesive laminate sheet of the present invention can be preferably employed from the viewpoint of economy and effective utilization of resources. On the other hand, as a part of the polymer gel-containing dispersion preparation step S1, in addition to using the sheet-like material of the crosslinked polymer composition (A) as described above, it was cut into a block shape or crushed Things may be immersed.

<Solvent>
In the polymer gel-containing dispersion preparation step S1, the cross-linked polymer composition (A) is immersed in a solvent and stirred. As the solvent used at this time, it is preferable to use a solvent capable of at least partially dissolving a linear polymer or branched polymer having a structural unit similar to that of the crosslinked polymer composition (A). Examples of such solvents include ester solvents such as ethyl acetate, methyl acetate, and butyl acetate; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as cyclohexane and n-hexane; acetone , Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran; and the like. Among them, it is more preferable to use ethyl acetate or toluene from the viewpoint of being inexpensive, excellent in handleability, and easily removing the solvent in the solvent removal step S4 described later.
A solvent may be used individually by 1 type and may use multiple types together.

The amount of the solvent in which the crosslinked polymer composition (A) is immersed may be an amount that can dissolve the non-crosslinked component of the crosslinked polymer composition (A). It can be set as appropriate depending on the gel fraction of A).

<Polymer gel-containing dispersion>
In the polymer gel-containing dispersion preparation step S1, the polymer-containing dispersion is prepared by immersing the cross-linked polymer composition (A) in a solvent and stirring. When the crosslinked polymer composition (A) is immersed in a solvent and stirred, non-crosslinked components such as linear polymers and branched polymers in the crosslinked polymer composition (A) absorb the solvent. After swelling, at least part of it is dissolved in the solvent. On the other hand, the cross-linking component in the crosslinked polymer-containing composition (A) exhibits finite swelling, absorbs the solvent, swells, and becomes a polymer gel without dissolving.
A schematic diagram is shown in S1 of FIG. That is, a polymer gel-containing dispersion 5 comprising a dispersion 3 containing a non-crosslinking component and a polymer gel 4 is prepared by immersing the crosslinked polymer-containing composition (A) 1 in a solvent 2 and stirring. . It should be noted that the non-crosslinking component does not necessarily exist, but is preferably present.

The method of stirring after immersing the crosslinked polymer composition (A) in a solvent gives a sufficient share to the crosslinked polymer composition (A) and the solvent, and has a particle size of a predetermined size. There is no particular limitation as long as a molecular gel can be produced. For example, in the case where 100 parts by mass of the block-like crosslinked polymer composition (A) is immersed in 300 parts by mass of ethyl acetate or toluene and then stirred, if the stirring is performed for 300 minutes at 1000 rpm, the crosslinked polymer composition The share of the product (A) and the solvent is sufficient, and a polymer gel having a predetermined particle size can be produced. The rotation speed and stirring time of stirring can be appropriately set depending on the mass, shape, or size (volume ratio with respect to the solvent) of the crosslinked polymer composition (A) immersed in the solvent.

From the viewpoint that the possibility of further crosslinking reaction of the crosslinked polymer composition (A) proceeding in the dispersion during the standing time in the polymer gel-containing dispersion preparation step S1 can be suppressed. It is preferable to add an antioxidant after dipping the composition (A) in a solvent. Examples of the antioxidant include polyphenol-based, hydroquinone-based and hindered amine-based antioxidants.
The usage-amount of antioxidant is 0.1 mass part or more and 10 mass parts or less with respect to 100 mass parts of (meth) acrylic resin precursors (P1) among the precursor compositions of a crosslinked-containing polymer composition (A). It is preferable that it is 0.3 mass part or more and 8 mass parts or less, and it is still more preferable that it is 0.5 mass part or more and 5 mass parts or less. By making the usage-amount of antioxidant into the said range, the polymer gel which has a particle diameter below the mesh opening of a mesh is produced, and it becomes easy to form the heat conductive pressure-sensitive-adhesive layer which has a micro unevenness | corrugation. Moreover, it becomes easy to give an appropriate cohesion force to a heat conductive pressure-sensitive-adhesive layer.
The timing of adding the antioxidant is not particularly limited as long as it is before the further crosslinking reaction of the crosslinked polymer composition (A) proceeds in the dispersion, and the crosslinked polymer composition (A) It may be added to the solvent before dipping in the solvent or simultaneously with dipping.

1.2. Filtration step S2
The filtration step S2 is a step of obtaining a filtrate by filtering the polymer gel-containing dispersion with a mesh having a predetermined opening. A schematic diagram is shown in S2 of FIG. That is, in the filtration step S2, the polymer gel-containing dispersion 5 is poured onto the fixed mesh 6 to obtain the filtrate 7. At this time, the polymer gel particles 4a having a particle diameter larger than the mesh opening of the mesh 6 remain on the mesh 6 as a residue, and the polymer gel 4b having a particle diameter equal to or smaller than the mesh 6 opening passes through the mesh. And contained in the filtrate 7.

The filtration method is not particularly limited as long as a filtrate that passes through a mesh having a predetermined particle diameter can be obtained. For example, natural filtration at normal temperature and normal pressure may be performed, and vacuum filtration or pressure filtration may be performed for the purpose of shortening the filtration time or improving the yield.

The mesh used in the filtration step S2 is not particularly limited as long as it can prevent fibers from expanding with respect to the solvent and changing the filtration accuracy. Examples of such mesh include metal mesh such as stainless steel mesh and galvanized mesh, and mesh made of resin such as nylon mesh, polyester mesh, polyethylene mesh, and Teflon (registered trademark) mesh. It is preferable to use a metal mesh from the viewpoint of safety, low cost, and availability.

The mesh opening needs to be 1.3 times or less the thickness of the filtrate to be applied on the base material layer described later. By making the mesh opening less than 1.3 times the thickness of the filtrate, it is possible to prevent the occurrence of pinholes when applying the filtrate, and the solvent is removed from the filtrate in the solvent removal step S4. When the heat conductive pressure-sensitive adhesive layer is formed, excessive irregularities can be prevented on the surface of the heat conductive pressure-sensitive adhesive layer. The resulting self-adhesiveness can be effectively imparted.
The mesh opening is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 600 μm or less. By setting the mesh opening to 1000 μm or less, the particle diameter of the polymer gel contained in the filtrate can be limited to the mesh opening or less, and even if the applied filtrate is thick, the solvent When the solvent is removed from the filtrate in the removing step S4 to form a heat conductive pressure-sensitive adhesive layer, it is possible to prevent the formation of excessive irregularities on the surface of the heat conductive pressure-sensitive adhesive layer. Self-adhesion caused by minute irregularities on the pressure-bonding layer surface can be more effectively imparted.
Further, the mesh opening is preferably 250 μm or more, more preferably 260 μm or more, and further preferably 280 μm or more. By setting the mesh opening to 250 μm or more, when the heat conductive pressure-sensitive adhesive layer is formed by removing the solvent from the filtrate in the solvent removal step S4, the surface of the heat conductive pressure-sensitive adhesive layer has an appropriate size. The air-removability and self-adhesiveness produced by the minute unevenness on the surface of the heat conductive pressure-sensitive adhesive layer can be effectively imparted.

The solid concentration of the filtrate obtained by the filtration step S2 is preferably 10 to 40% by mass, more preferably 15 to 35% by mass. When the solid content concentration of the filtrate is in the range of 10 to 40% by mass, the handleability of the filtrate is excellent, and it becomes easy to apply the filtrate to a predetermined thickness in the application step S3 described later. Removal of the solvent is facilitated in the solvent removal step S4.

The gel fraction of the crosslinked polymer-containing composition (H) after filtration is 75% by mass or more, and preferably 85% by mass or more. When the gel fraction is 75% by mass or more, a polymer gel having a particle size equal to or smaller than the mesh opening is produced, and a heat conductive pressure-sensitive adhesive layer having minute irregularities is easily produced. On the other hand, the gel fraction of the crosslinked polymer-containing composition (H) after filtration is preferably 99% by mass or less, and more preferably 95% by mass or less. When the gel fraction is 99% by mass or less, in the heat conductive pressure-sensitive adhesive layer, in the heat conductive pressure-sensitive adhesive sheet, the non-crosslinking component serves to connect the cross-linking components together. It is possible to effectively prevent the heat conductive pressure-sensitive adhesive layer from peeling off from the material layer, and it is possible to increase the pressure-sensitive adhesive property of the heat conductive pressure-sensitive adhesive laminate sheet (F).
The gel fraction of the post-filtration crosslinked polymer composition (H) in the present invention is, for example, a 0.2 g dry sample of the post-filtration crosslinked polymer composition (H) wrapped in a wire mesh with an opening of 234 μm, and acetic acid. It is immersed in 100 ml of ethyl for 24 hours and filtered, and then the wire mesh taken out is dried at 50 ° C. for 1 hour, and the dry mass of the insoluble matter remaining on the wire mesh having an opening of 234 μm is measured. This is the required value.
Gel fraction (mass%) = ((dry mass of insoluble matter remaining in wire mesh with opening of 234 μm after immersion in ethyl acetate) / (dry mass of sample before immersion in ethyl acetate)) × 100

1.3. Application process S3
The coating step S3 is a step of coating the filtrate on the base material layer to a predetermined thickness. The laminated body by which the filtrate 7 was apply | coated to the base material layer 8 to S3 of FIG. The method for applying the filtrate to the base material layer in the application step S3 is not particularly limited, and a known application method can be applied. For example, a coating method using a die coater, a bar coater, a gravure coater, a knife coater, a roll coater, a doctor blade or the like can be employed.

As described above, the mesh opening used in the filtration step S2 needs to be 1.3 times or less the thickness applied on the base material layer. Therefore, it is necessary that the thickness of the filtrate applied on the base material layer be (1.3 times) or more (that is, 0.77 or more) times the mesh opening. Further, while satisfying such conditions, the thickness of the filtrate to be applied is preferably 200 μm or more and 800 μm or less, more preferably 250 μm or more and 700 μm or less, and further preferably 300 μm or more and 600 μm or less. By setting the thickness of the filtrate to be applied within the above range, sufficient adhesion can be maintained between the heat-conductive pressure-sensitive adhesive layer and the adherend.

<Base material layer>
A base material layer is a layer which apply | coats the filtrate obtained by filtration process S2. Further, the base material layer becomes a base of the heat conductive pressure-sensitive adhesive layer after the solvent removal step S4, so that the sheet shape can be maintained even when the cohesive force of the heat conductive pressure-sensitive adhesive layer is somewhat insufficient. Moreover, a heat conductive pressure-sensitive-adhesive layer can be reinforced and tearing at the time of use of a heat conductive pressure-sensitive-adhesive laminated sheet (F) can be prevented.
The base material layer can be given a specific function depending on the application, and can be a functional layer such as a protective layer, a decorative layer, an insulating layer, a heat conductive layer, a heat diffusion layer, or the like. . Moreover, you may interpose another layer between the base material layer and a heat conductive pressure sensitive adhesive layer in the range which does not prevent the effect which this invention intends.

It is preferable that the base material layer has a strength capable of reinforcing the heat conductive pressure-sensitive adhesive layer so that the heat conductive pressure-sensitive adhesive layer is not broken when the heat conductive pressure-sensitive adhesive laminated sheet (F) is used. It is preferably larger than the pressure-sensitive adhesive layer. Moreover, since it is necessary to deform | transform following a heat conductive pressure sensitive adhesive layer, it is preferable to have flexibility.

The material constituting the base material layer satisfying the above conditions is paper; cloth; metal foil; polyimide; polyester such as polyethylene terephthalate and polyethylene naphthalate; fluororesin such as polytetrafluoroethylene; polyether ketone; Polysulfone; Polymethylpentene; Polyetherimide; Polysulfone; Polyphenylene sulfide; Polyamideimide; Polyesterimide; Polyamide; Among these, polyester and polyimide are preferable, polyethylene terephthalate and polyimide are more preferable, and polyethylene terephthalate is still more preferable from the viewpoint of availability at low cost. In addition, the base material layer may be composed of one kind of material or may be composed of a combination of plural kinds of materials.

The base material layer is usually made of a material that does not have pressure-sensitive adhesiveness. Therefore, when the object is placed in contact with the surface of the base material layer, the surface of the heat conductive pressure-sensitive adhesive laminate sheet (F) is prevented from sticking to the object when the object is removed from the surface of the base material layer. Therefore, even when the object is re-fixed, the heat conductive pressure-sensitive adhesive laminated sheet (F) can be reused as it is. From this viewpoint, it is preferable that the surface of the base material layer has slipperiness. However, when fixing an object to the base material layer side of the heat conductive pressure-sensitive adhesive laminated sheet (F), it is preferable to use a fixing member such as a screw. In addition, the base material layer may be comprised with the material which has pressure sensitive adhesiveness.
Moreover, when providing a specific function to a base material layer, the base material layer may be comprised, for example from the material which has electrical insulation, and a heat conductive material (TIM: Thermal Interface Material).

The thickness of the base material layer can be appropriately set according to the use of the heat conductive pressure-sensitive adhesive laminate sheet (F) and the function required for the base material layer, but the thermal resistance is lowered. From a viewpoint and the viewpoint which prevents a wrinkle at the time of use, the thinner one is preferable. On the other hand, it is preferable that the base material layer has a certain thickness from the viewpoint of providing the heat conductive pressure-sensitive adhesive laminate sheet (F) with a strength capable of preventing tearing during use. Therefore, the thickness of the base material layer is preferably 1 μm to 200 μm, more preferably 5 μm to 100 μm, still more preferably 10 μm to 70 μm, and particularly preferably 10 μm to 30 μm.

Further, the thermal conductivity in the thickness direction of the base material layer is not particularly limited as long as the thickness of the base material layer satisfies the above range, but it is easy to select a flexible material and no filler is blended. In order to easily maintain strength and reduce flexibility while reducing the thickness, it is preferable that the thermal conductivity in the thickness direction of the base material layer is less than 1.0 W / (m · K).

1.4. Solvent removal step S4
The solvent removal step S4 is a step of removing the solvent from the filtrate on the substrate to obtain a heat conductive pressure sensitive adhesive layer. The method for removing the solvent in the solvent removal step S4 is not particularly limited, and a known method can be applied. For example, a method of allowing a laminate having a base material layer and a filtrate coating film to stand in the air and evaporating the solvent spontaneously; A method of performing; a method of heating a laminate having a base material layer and a filtrate coating film into an oven; and the like. The heating temperature in the case of using the heating method is not particularly limited as long as the solvent can be vaporized and the function of the base material layer is not impaired. For example, when the solvent is ethyl acetate (boiling point 77.1 ° C.), the heating temperature may be about 100 ° C., and when the solvent is toluene (boiling point 110 ° C.), the heating temperature may be about 150 ° C. Preferably, it is not lower than the boiling point of the solvent and not higher than 200 ° C. The heating time can be appropriately set according to the amount of the filtrate to be applied on the substrate, and is preferably 10 minutes to 3 hours.

<Thermal conductive pressure-sensitive adhesive layer (single side)>
In solvent removal process S4, a heat conductive pressure-sensitive contact bonding layer is formed on a base material layer by removing a solvent from the filtrate on a base material layer. A schematic diagram of the heat conductive pressure-sensitive adhesive laminate sheet (F) 10 in which the heat conductive pressure-sensitive adhesive layer 9 is laminated on one side of the base material layer 8 is shown in S4 of FIG. As shown in S <b> 4 of FIG. 2, irregularities are formed on the surface of the heat conductive pressure-sensitive adhesive layer 9. The unevenness is minute and does not affect the appearance.
According to the heat conductive pressure-sensitive adhesive laminate sheet (F) 10 manufactured by the present manufacturing method S10, the surface of the heat conductive pressure-sensitive adhesive layer is formed with minute irregularities, whereby the heat conductive pressure-sensitive adhesive. Since the air that is bitten when the conductive laminated sheet (F) 10 is affixed can be extracted from the uneven portion to the outside, the biting of air can be effectively suppressed. In addition, the uneven portion functions like a suction cup and adheres to the adherend by applying pressure so that it is pressed from the base material layer side. And thermal conductivity are not reduced.

In the first aspect of the present invention, the thickness of the heat conductive pressure-sensitive adhesive layer is not particularly limited, but the thickness of the heat conductive pressure-sensitive adhesive sheet (F) is reduced by forming the heat conductive pressure-sensitive adhesive layer thin. The thermal resistance in the vertical direction can be lowered. On the other hand, the heat conductive pressure-sensitive adhesive layer (F) can be easily handled by providing the heat conductive pressure-sensitive adhesive layer with a certain thickness. From these viewpoints, the thickness of the heat conductive pressure-sensitive adhesive layer is preferably 50 μm or more and 800 μm or less, more preferably 80 μm or more and 600 μm or less, and further preferably 100 μm or more and 450 μm or less.

2. Manufacturing method of heat conductive pressure-sensitive adhesive laminated sheet (F) (II)
Next, the manufacturing method of the heat conductive pressure-sensitive-adhesive laminated sheet (F) which concerns on the 2nd aspect of this invention is demonstrated. FIG. 3 is a flowchart for explaining a production method S20 (hereinafter sometimes abbreviated as “the present production method S20”) of the heat conductive pressure-sensitive adhesive laminated sheet (F) according to the second aspect of the present invention. is there. As shown in FIG. 3, this production method S20 includes a polymer gel-containing dispersion preparation step S11, a filtration step S12, a first application step S13, a first solvent removal step S14, a second application step S15, Second solvent removal step S16. FIG. 4 is a diagram schematically showing the states of steps S11 to S16 of the manufacturing method S20. As shown in S16 in the lower right of FIG. 4, the heat conductive pressure-sensitive adhesive laminated sheet (F) 20 produced by this production method S20 includes a base material layer 8 as an intermediate layer and front and back layers having irregularities on the surface. As a heat conductive pressure-sensitive adhesive layer 9. Hereinafter, each step will be described.

2.1. Polymer gel-containing dispersion preparation step S11
The polymer gel-containing dispersion preparation step S11 can be the same step as the polymer gel-containing dispersion preparation step S1. In the description regarding the polymer gel-containing dispersion preparation step S1, “S1” is “S11”, “solvent removal step S4” is “first solvent removal step S14 and second solvent removal step S16”, “ “FIG. 2” is read as “FIG. 4”.

2.2. Filtration step S12
The filtration step S12 can be the same step as the filtration step S2. In the description regarding the filtration step S2, “S2” is “S12”, “application step S3” is “first application step S13 and second application step S15”, and “solvent removal step S4” is “first”. “Solvent removal step S14 and second solvent removal step S16” and “FIG. 2” are read as “FIG. 4”.

2.3. 1st application process S13
The first application step S13 is a step of applying the filtrate obtained in the filtration step S12 to a predetermined thickness on one surface of the base material layer. The first application step S13 can be the same step as the application step S3. In the description regarding the coating step S3, the “coating step S3” is “first coating step S13”, the “filtration step S2” is “filtration step S12”, and the “solvent removal step S4” is “first solvent removal”. “Step S14 and second solvent removal step S16” and “FIG. 2” are read as “FIG. 4”. Moreover, since the heat conductive pressure-sensitive-adhesive sheet (F) which concerns on the 2nd aspect of this invention has the heat conductive pressure-sensitive adhesive layer laminated | stacked on both surfaces of a base material layer, normally a heat generating body or a heat radiator. Is contacted via a thermally conductive pressure-sensitive adhesive layer instead of the base material layer. Therefore, in the description regarding the coating step S3, properties such as “slipperiness” that are preferably provided on the surface of the base material layer are not necessarily required.

2.4. First solvent removal step S14
The first solvent removing step S14 is a step of obtaining a heat conductive pressure-sensitive adhesive layer by removing the solvent from the filtrate applied to one surface of the base material layer in the first applying step S13. A laminated body in which the heat conductive pressure-sensitive adhesive layer 9 is laminated on one surface of the base material layer 8 is shown in S14 of FIG. The method for removing the solvent in the first solvent removal step S14 is not particularly limited, and the known methods exemplified in the solvent removal step S4 can be applied.

2.5. Second application step S15
The second application step S15 is a step of applying the filtrate obtained in the filtration step S12 to a predetermined thickness on the other surface of the base material layer (the surface opposite to the surface on which the filtrate is applied in the first application step S13). is there. A laminated body in which the heat conductive pressure-sensitive adhesive layer 9 is laminated on one surface of the base material layer 8 and the filtrate 7 is applied to the other surface is shown in S15 of FIG. The method of applying the filtrate to the base material layer in the second application step S15 and the thickness of the filtrate to be applied can be the same as those in the first application step S13.

2.6. Second solvent removal step S16
The second solvent removing step S16 is a step of obtaining a heat conductive pressure sensitive adhesive layer by removing the solvent from the filtrate applied to the other surface of the base material layer in the second applying step S15. A heat conductive pressure-sensitive adhesive layer 9 is laminated on the other surface of the base material layer 8 in S16 of FIG. 2, and the heat conductive pressure sensitive

adhesive layers

9 and 9 are laminated on both surfaces of the base material layer 8. The pressure-adhesive laminated sheet (F) 20 is shown. The method for removing the solvent in the second solvent removal step S16 can be the same as that in the first solvent removal step S14.

<Thermal conductive pressure-sensitive adhesive layer (both sides)>
In the first solvent removal step S14 and the second solvent removal step S16, the solvent is removed from the filtrate on the base material layer to form a heat conductive pressure sensitive adhesive layer on the base material layer. 4 shows that the heat conductive pressure-sensitive adhesive layer 9 is laminated on one side of the base material layer 8, and in S16 of FIG. 4, the heat conductive pressure-sensitive adhesive layer 9, A state where 9 is laminated is shown. As shown in S <b> 14 and S <b> 16 of FIG. 4, irregularities are formed on the surface of the heat conductive pressure-sensitive adhesive layer 9. The unevenness is minute and does not affect the appearance.
According to the heat conductive pressure-sensitive adhesive laminated sheet (F) 20 manufactured by the present manufacturing method S20, the heat conductive pressure-sensitive adhesive is formed by forming minute irregularities on the surface of the heat conductive pressure-sensitive adhesive layer. Since the air that is bitten at the time of attaching the conductive laminate sheet (F) 20 can be extracted from the uneven portion to the outside, the biting of air can be effectively suppressed. In addition, the uneven portion functions like a suction cup and adheres to the adherend by applying pressure so that it is pressed from the base material layer side. And thermal conductivity are not reduced.

In the second aspect of the present invention, the thickness of the heat conductive pressure-sensitive adhesive layer is not particularly limited, but the thickness of the heat conductive pressure-sensitive adhesive laminated sheet (F) is reduced by forming the heat conductive pressure-sensitive adhesive layer thin. The thermal resistance in the vertical direction can be lowered. On the other hand, the heat conductive pressure-sensitive adhesive layer (F) can be easily handled by providing the heat conductive pressure-sensitive adhesive layer with a certain thickness. From these viewpoints, the thickness of one layer of the heat conductive pressure-sensitive adhesive layer is preferably 50 μm or more and 800 μm or less, more preferably 80 μm or more and 600 μm or less, and more preferably 100 μm or more and 450 μm or less. Further preferred.

The polymer gel-containing dispersion preparation step S11, the filtration step S12, the first application step S13, the first solvent removal step S14, the second application step S15, and the second solvent removal step S16 are as described above. Although this manufacturing method S20 was demonstrated about the form included in order, this invention is not limited to the said embodiment. For example, after applying the filtrate to a predetermined thickness on the front and back of the base material layer, after removing the solvent from the filtrate on the front and back of the base material layer, that is, after performing the first application step S13 and the second application step S15, It is good also as a form which performs 1st solvent removal process S14 and 2nd solvent removal process S16 simultaneously.

3. Various characteristics According to the through holes and slits formed in the conventional sheet, since the through holes and slits penetrate in the thickness direction of the sheet, the heating element and the heat radiating body communicate with each other in the thickness direction through the air layer. Therefore, there is a possibility that the thermal conductivity is impaired. Moreover, when the base material layer is provided with a specific function, the function of the base material layer may not be exhibited in the through hole or the slit portion. On the other hand, in the heat conductive pressure-sensitive adhesive laminate sheet (F) according to the present invention, since the unevenness is formed only in the heat conductive pressure-sensitive adhesive layer, the heating element and the heat radiating body are in the thickness direction through the air layer. The thermal conductivity is unlikely to decrease. Moreover, there is no possibility that the function of a base material layer will be impaired. Furthermore, the production of the heat conductive pressure-sensitive adhesive laminated sheet (F) by this production method does not require precise processing using a laser or a cutter, and can be carried out with simple production equipment.

4). Use Example The heat conductive pressure-sensitive adhesive laminate sheet (F) of the present invention has high heat conductivity of the heat conductive pressure-sensitive adhesive layer, and the heat conductive pressure-sensitive adhesive layer has pressure-sensitive adhesiveness. By interposing between a heat generating body and a heat radiating body, it can be used for applications such as efficiently conducting heat from the heat generating body to the heat radiating body. Moreover, the heat conductive pressure-sensitive-adhesive laminated sheet (F) of this invention can be attached to the electronic component which is a heat generating body with which an electronic device is equipped, and can be used as a part of this electronic component. The usage example of the heat conductive pressure-sensitive-adhesive laminated sheet (F) of this invention is demonstrated referring FIG. FIG. 5 is a diagram for explaining a usage example of the heat conductive pressure-sensitive adhesive laminated sheet (F).

FIG. 5A is a perspective view schematically showing a part of an electronic device such as a personal computer. FIG. 5A shows a substrate 11, an electronic component 12 that is a heating element installed on the substrate 11, a heat sink 13 that is a radiator, and a thermally conductive pressure-sensitive adhesive disposed between the electronic component 12 and the heat sink 13. The laminated sheet (F) 14 is shown.
As shown in FIG. 5 (A), the thermal conductivity and pressure sensitive adhesive laminate sheet (F) 14 is sandwiched between the electronic component 12 and the heat sink 13 and fixed by an arbitrary fixing means such as a screw. Since the pressure-bonding laminated sheet (F) 14 (heat conductive pressure-sensitive adhesive layer) has high thermal conductivity, the heat generated by the electronic component 12 causes the heat-conductive pressure-sensitive adhesive sheet (F) 14 to flow. Through the heat sink 13 and efficiently dissipated from the heat sink 13.

FIG. 5B schematically shows a state in which the NPN transistor 22a and the PNP transistor 22b, which are heating elements, are attached to the heat sink 23, which is a radiator, through the heat conductive pressure-sensitive adhesive laminated sheets (F) 24, 24. It is a perspective view shown.
As shown in FIG. 5 (B), by attaching the NPN transistor 22a and the PNP transistor 22b to the single heat sink 23 via the heat conductive pressure-sensitive adhesive laminated sheets (F) 24, 24 by any fixing means, Since the heat conductive pressure-sensitive adhesive laminate sheet (F) 24 (heat conductive pressure-sensitive adhesive layer) has high heat conductivity, the heat generated by the NPN transistor 22a and the PNP transistor 22b is heat conductive pressure-sensitive adhesive. It is efficiently transmitted to the heat sink 23 through the laminated sheets (F) 24, 24 and is radiated from the heat sink 23. At this time, the NPN transistor 22a and the PNP transistor 22b are both attached to one heat sink 23 via the heat conductive pressure-sensitive adhesive laminate sheets (F) 24 and 24 having high heat conductivity, thereby allowing NPN It is possible to suppress a temperature difference between the transistor 22a and the PNP transistor 22b.

FIG. 5C is a cross-sectional view schematically showing a state in which the two

transistors

32 and 32 which are heating elements are fixed by an arbitrary fixing means via the heat conductive pressure-sensitive adhesive laminated sheet (F) 34. is there.
As shown in FIG. 5C, the two

heat generating elements

32, 32 are fixed via the heat conductive pressure-sensitive adhesive laminate sheet (F) 34, whereby the heat conductive pressure-sensitive adhesive laminate sheet (F ) 34 (thermally conductive pressure-sensitive adhesive layer) has high thermal conductivity, so if one of the two

heating elements

32, 32 becomes higher in temperature than the other, heat is rapidly transferred from one to the other. Therefore, it is possible to suppress a temperature difference between the two

heating elements

32 and 32.

In the above example, the heat sink is used as the heat radiating body, but the housing of the electronic component or the like can also be used as the heat radiating body. Hereinafter, other usage examples of the heat conductive pressure-sensitive adhesive laminated sheet (F) will be described.

The heat conductive pressure-sensitive adhesive laminated sheet (F) of the present invention can be used as a part of an electronic component provided in an electronic device. Specific examples of the electronic device and electronic component include electroluminescence (EL), a component around a heat generating part in a device having a light emitting diode (LED) light source, a component around a power device such as an automobile, a fuel cell, a solar cell, and a battery. , Devices and parts having heat generating parts such as mobile phones, personal digital assistants (PDAs), notebook computers, liquid crystal panels, surface conduction electron-emitting device displays (SED), plasma display panels (PDP), or integrated circuits (ICs) Can be mentioned.

In addition, as an example of a method for using the heat conductive pressure-sensitive adhesive laminate sheet (F) of the present invention for an electronic device, a method for using the LED light source as described below can be used. That is, it is directly attached to the LED light source; sandwiched between the LED light source and a heat dissipation material (heat sink, fan, Peltier element, heat pipe, graphite sheet, etc.); , Heat pipe, graphite sheet, etc.); used as a housing surrounding the LED light source; pasted on a housing surrounding the LED light source; filling a gap between the LED light source and the housing; Examples of LED light source applications include backlight devices for display devices having transmissive liquid crystal panels (TVs, mobile phones, PCs, notebook PCs, PDAs, etc.); vehicle lamps; industrial lighting; commercial lighting; Lighting; and the like.

Further, specific examples other than the LED light source include the following. That is, PDP panel; IC heating part; Cold cathode tube (CCFL); Organic EL light source; Inorganic EL light source; High luminance light emitting LED light source; High luminance light emitting organic EL light source; And so on.

Furthermore, as a method for using the heat conductive pressure-sensitive adhesive laminated sheet (F) of the present invention, it can be applied to the housing of the apparatus. For example, when used in a device provided in an automobile or the like, it is affixed inside a casing provided in the automobile; affixed outside the casing provided in the automobile; a heat generating part (inside the casing provided in the automobile) Connecting the car navigation / fuel cell / heat exchanger) and the housing; affixing to a heat sink connected to the heat generating part (car navigation / fuel cell / heat exchanger) in the housing of the automobile; Etc.

In addition to the automobile, the heat conductive pressure-sensitive adhesive laminate sheet (F) of the present invention can be used in the same manner. For example, personal computers; homes; TVs; mobile phones; vending machines; refrigerators; solar cells; surface-conduction electron-emitting device displays (SEDs); organic EL displays; inorganic EL displays; Organic EL display; laptop computer; PDA; fuel cell; semiconductor device; rice cooker; washing machine; laundry dryer; optical semiconductor device combining optical semiconductor elements and phosphors; Is mentioned.

Furthermore, the heat conductive pressure-sensitive adhesive laminated sheet (F) of the present invention is not limited to the above-described usage method, and can be used in other methods depending on the application. For example, used for heat uniformity of carpets and warm mats, etc .; used as LED light source / heat source sealant; used as solar cell sealant; used as solar cell backsheet Used between the backsheet of the solar cell and the roof; used inside the heat insulating layer inside the vending machine; used inside the housing of the organic EL lighting with a desiccant or a hygroscopic agent; organic EL lighting Use with desiccant and hygroscopic agent on the heat conductive layer inside the housing of the LED; Use with desiccant and hygroscopic agent on the heat conductive layer and heat dissipation layer inside the housing of the organic EL lighting Used for heat conduction layer inside the housing of organic EL lighting, epoxy heat dissipation layer, and on top of it with desiccant and moisture absorbent; cooling equipment, clothing, towels, sheets, etc. for cooling humans and animals Used on the opposite side of the body to the member Used as a pressure member of a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer; Pressing member of a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer Used as a heat transfer part for heat flow control on which the treatment object of the membrane control device is placed; Used for a heat transfer part for heat flow control on which the treatment object of the film control device is placed; and the outer layer of the radioactive substance storage container It is used between interiors; it is used in a box body provided with a solar panel that absorbs sunlight; it is used between a reflective sheet of a CCFL backlight and an aluminum chassis.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. The “parts” and “%” used here are based on mass unless otherwise specified.

[Evaluation Method (I)]
The performance of the heat conductive pressure-sensitive adhesive laminated sheets according to Examples 1 to 3 having a heat conductive pressure-sensitive adhesive layer on one side and the sheet obtained in Comparative Example 1 were evaluated by the methods shown below.

<Air venting>
As described later, after producing a heat conductive pressure-sensitive adhesive laminated sheet (hereinafter, simply referred to as “sheet”), it is cut into a square of 100 mm × 100 mm, and the surface on the heat conductive pressure-sensitive adhesive layer side is It put on the glass plate so that it might contact | connect, and the roller with a load of 0.5 gf was reciprocated once from the surface by the side of a base material layer, and it affixed on the glass plate. At this time, the evaluation was made based on whether or not there is an air pocket in which the area calculated by the following is 100 mm ² or more. The results are shown in Table 3, where “◯” indicates that there is no air pocket where the area calculated as follows is 100 mm ² or more, and “×” indicates that there is an air pocket. If this evaluation is “◯”, it can be said that there is little air to be caught and the adhesiveness and appearance quality are excellent.
The area of the air reservoir was calculated by drawing a rectangle with the smallest area that can surround the largest air reservoir and measuring the area of the rectangle.

<Reworkability>
After carrying out the air bleedability test, it was left for 3 hours. Thereafter, the sheet was peeled off from the glass plate, and the evaluation was made based on whether or not the sheet residue, which is a part of the heat conductive pressure-sensitive adhesive layer, remained on the glass plate. The results are shown in Table 3 where “◯” indicates that no sheet residue remains and “×” indicates that the sheet residue does not remain. If this evaluation is “◯”, it can be said that re-sticking is easy and the usability is excellent. In addition, subsequent evaluation was not performed when air bleedability and this evaluation were "x".

<Slipperiness>
After producing the sheet as described later, the sheet was cut into a square of 100 mm × 100 mm, and fixed so that the base material layer was on the upper side on an inclined surface having an inclination of 60 ° with respect to the horizontal plane. Thereafter, a 0.2 kg weight of lead was placed on the sheet, and evaluation was made based on whether or not the weight slipped. The results are shown in Table 3 with “◯” when the weight slips and “x” when the weight does not move. If this evaluation is “◯”, it can be said that the fine adjustment of the fixed position of the object arranged on the base material layer side is easy and the usability is excellent.

<Z-axis direction thermal conductivity>
By the thermal diffusivity (Td: m ² / s), specific heat capacity (Cp: J / kg · K), and density (ρ: kg / m ³ ) obtained by the following method, the following formula (1 ) To calculate the Z-axis direction thermal conductivity (Tc: W / m · K).
Tc = Td × Cp × ρ (1)
(Thermal diffusivity (Td))
After producing the sheet as described later, the sheet is cut into a square of 100 mm × 100 mm, and the sheet is sandwiched between the arms of the apparatus by a thermal diffusion measuring apparatus ai-phase mobile 1 (manufactured by SII Nanotechnology Co., Ltd.) The thermal diffusivity (Td: m ² / s) is measured.
(Specific heat capacity (Cp))
Nine sheets are cut and overlapped, rounded into a cylindrical shape, made into a cylindrical sample with an outer diameter of 20 mm, an inner diameter of 18 mm, and a height of 20 mm, and this is conditioned for 24 hours at 23 ° C. and 50% relative humidity Using a differential scanning calorimeter (DSC): “adiabatic specific heat measuring device SH series” (manufactured by ULVAC, Inc.), the sample is heated to a temperature at least 30 ° C. higher than that at the end of the glass transition. After maintaining for a minute, the DSC curve in the process of cooling to a temperature 20 ° C. lower than the lower limit temperature of the specific heat capacity measurement range at a cooling rate of 5 ° C. per minute is determined by measurement. The same measurement is performed for the reference material (sapphire) and the empty container, and the specific heat capacity (Cp: J / kg · K) is obtained by the following equation (2).
Cp = (h / H) × (m / M) × Cp ′ (2)
However, Cp ′: specific heat capacity of reference material (sapphire) (J / kg · K), m: weight of sample (kg), M: weight of reference material (sapphire) (kg), h: empty container and sample Difference in longitudinal direction (W) in DSC curve, H: Difference in longitudinal direction (W) in DSC curve between empty container and reference material (sapphire).
(Density (ρ))
Cut the sheet into a sample, use a Le Chatelier specific gravity bottle, weigh the sample (W: kg), read the amount of water in the meniscus before putting the sample solid into the specific gravity bottle (L1: m ³ ), and measure the specific gravity of the sample solid reading of the meniscus of water after a bottle ^{^{as:: (kg / m 3 ρ}} ) is measured (density = 1000 kg / ^{m 3} of water (L2 ^m 3), the determined, following the density by the formula (3) )
ρ = W / (L2-L1) (3)
The results are shown in Table 3. If the thermal conductivity in the Z-axis direction is 0.8 W / m · K or more, it can be said that the thermal resistance is low.

[Preparation of heat conductive pressure-sensitive adhesive laminate sheet]
Example 1
A reactor was charged with 100 parts of a monomer mixture composed of 94% 2-ethylhexyl acrylate and 6% acrylic acid, 0.03 parts 2,2′-azobisisobutyronitrile and 700 parts ethyl acetate. Then, after substitution with nitrogen, a polymerization reaction was carried out at 80 ° C. for 6 hours. The polymerization conversion rate was 97%. The obtained polymer was dried under reduced pressure to evaporate ethyl acetate to obtain a viscous solid (meth) acrylic acid ester polymer (A1-1). The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1-1) was 270,000, and the weight average molecular weight (Mw) / number average molecular weight (Mn) was 3.1. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined in terms of standard polystyrene by gel permeation chromatography using tetrahydrofuran as an eluent.

Next, 69 parts of 2-ethylhexyl acrylate (2EHA) and an organic peroxide thermal polymerization initiator (1,6-bis (t-butylperoxycarbonyloxy) hexane (1 minute half-life temperature is 150 ° C.). )) A polyfunctional monomer (light acrylate PE-3A, Kyoeisha), which is a mixture of 1 part and pentaerythritol triacrylate, pentaerythritol tetraacrylate and pentaerythritol diacrylate in a ratio of 60: 35: 5 1 part of Chemical Co., Ltd. and aluminum hydroxide (trade name “BF-083”, manufactured by Nippon Light Metal Co., Ltd.) as the thermally conductive filler (C1), average particle size: 8 μm, BET specific surface area: 0.8 m ² / G) 300 parts and alumina (made by Showa Denko KK, trade name “AL-47-H”, average particle size: 3 μm, B Electrons and 1.1 m 2 / g) 300 parts of phosphoric acid ester (manufactured by Ajinomoto Fine-Techno Co., Ltd., trade name "Reophos 65", the compound name "triaryl phosphate isopropyl halide") 85 parts of ^a: T specific surface area These were weighed with a balance and mixed with 30 parts of the (meth) acrylic acid ester polymer (A1-1). For the mixing, a thermostatic bath (manufactured by Toki Sangyo Co., Ltd., trade name “Viscomate 150III”) and a Hobart mixer (manufactured by Kodaira Manufacturing Co., Ltd., trade name “ACM-5LVT type”, capacity: 5 L) were used. The temperature control of the Hobart container was set to 50 ° C., the vacuum (−0.1 MPaG) was applied, the rotation speed scale was set to 3, and the mixture was stirred for 30 minutes to obtain a precursor composition Z1.

Next, the precursor composition Z1 was dropped on a release PET film having a thickness of 75 μm, and another release PET film having a thickness of 75 μm was further covered on the precursor composition Z1. Two laminates in which the precursor composition Z1 was sandwiched between release PET films were adjusted so that the thickness of the precursor composition Z1 (crosslinked polymer composition (A)) was 1 mm. The precursor composition Z1 was formed into a sheet by passing between rolls. Thereafter, the laminate was put into an oven, heated at 120 ° C. for 15 minutes, and then heated at 150 ° C. for 25 minutes. As a result, the (meth) acrylic acid ester monomer and the polyfunctional monomer are polymerized, and at the same time, the (meth) acrylic acid ester polymer (A1- A polymer containing a structural unit derived from 1) and a (meth) acrylic acid ester monomer was crosslinked to obtain a crosslinked polymer-containing composition (A) having a thickness of 1 mm sandwiched between release films. The polymerization conversion rate of all monomers was calculated from the amount of residual monomers in the crosslinked polymer composition (A) and found to be 99.9%.

Next, 300 parts by weight of toluene, 1 part by weight of an antioxidant (AO-60, manufactured by ADEKA Corporation) and 100 parts by weight of the crosslinked polymer composition (A) were placed in a reactor, The molecular composition (A) was immersed in toluene. Thereafter, using a Hobart mixer (Kodaira Seisakusho, trade name: ACM-5 LVT type), the mixture was stirred for 300 minutes at a rotation speed of 1000 rpm to prepare 401 parts by mass of a polymer gel-containing dispersion.

Next, a metal mesh having an opening of 299 μm is fixed on a reactor different from the reactor in which the polymer gel-containing dispersion is placed, and 401 parts by mass of the polymer gel-containing dispersion is placed on the metal mesh. By pouring and passing through a metal mesh, 386 parts by mass of a filtrate was produced (ie, 15 parts by mass was a component that could not pass through a 299 μm mesh). The solid content concentration of the filtrate was 22.0%.
A part of the filtrate obtained after filtering the crosslinked polymer composition (A) was vacuum-dried to obtain a crosslinked polymer composition (H) after filtration. With respect to the crosslinked polymer-containing composition (H) after filtration, the gel fraction was measured and found to be 89.5% by mass. Thereby, it is calculated that the gel fraction of the crosslinked polymer-containing composition (A) measured at an opening of 234 μm is 91.1% by mass.

Next, the filtrate was applied on a PET film having a thickness of 20 μm cut to 200 mm × 300 mm by using a bar coater so as to have a thickness of 400 μm.

Next, the laminate composed of the PET film and the filtrate coating film was put into an oven and heated at 150 ° C. for 30 minutes. By evaporating the solvent from the filtrate by this solvent removal step, a heat conductive pressure sensitive adhesive layer having a thickness of 200 μm is formed on the PET film, and the heat conductive pressure sensitive adhesive layer is formed on one side of the PET film as the base material layer. The heat conductive pressure-sensitive-adhesive laminated sheet (F) obtained by laminating was obtained.

(Examples 2 and 3 and Comparative Example 1)
The compounding of each substance used for the precursor composition was changed to the precursor composition Z2 or ZC1 in place of the precursor composition Z1 in Table 2 used in Example 1, and was the same as in Example 1. Sheets according to Example 2 and Comparative Example 1 were produced. Moreover, the sheet | seat which concerns on Example 3 was produced like Example 1 except having changed the base material layer from the polyimide film to the polyimide film.

As shown in Table 3, all of the sheets according to Examples 1 to 3 were excellent in air bleedability, reworkability, and slipperiness, and had an appropriate thermal conductivity in the thickness direction. On the other hand, the sheet | seat which concerns on the comparative example 1 in which the precursor composition did not contain the polyfunctional monomer was inferior to air bleeding property and rework property.

[Evaluation method (II)]
Next, the performances of the heat conductive pressure-sensitive adhesive laminated sheets according to Examples 4 to 6 having the heat conductive pressure-sensitive adhesive layers on both sides and the sheets obtained in Comparative Examples 2 and 3 were as follows. evaluated.

<Air venting>
As will be described later, a heat conductive pressure-sensitive adhesive laminated sheet (hereinafter sometimes simply referred to as “sheet”) having a heat conductive pressure-sensitive adhesive layer 1 and a heat conductive pressure-sensitive adhesive layer 2 as front and back layers is prepared. After that, it is cut into a square of 100 mm × 100 mm, placed on a glass plate so that the surface of the heat conductive pressure-sensitive adhesive layer 1 or the heat conductive pressure-sensitive adhesive layer 2 is in contact, and a roller with a load of 0.5 gf is reciprocated once from the top Affixed to a glass plate. At this time, the evaluation was made based on whether or not there is an air pocket in which the area calculated by the following is 100 mm ² or more. The results are shown in Table 4 where “◯” indicates the case where there is no air pocket where the area calculated as follows is 100 mm ² or more, and “X” indicates the presence. If this evaluation is “◯”, it can be said that there is little air to be caught and the adhesiveness and appearance quality are excellent. In addition, when this evaluation was "x", calculation of the Z-axis direction thermal conductivity mentioned later was not performed.
The area of the air reservoir was calculated by drawing a rectangle with the smallest area that can surround the largest air reservoir and measuring the area of the rectangle.

<Z-axis direction thermal conductivity>
The Z-axis direction thermal conductivity was calculated by the same method as <Z-axis direction thermal conductivity> included in the evaluation method (I). The results are shown in Table 4. If the thermal conductivity in the Z-axis direction is 0.8 W / m · K or more, it can be said that the thermal resistance is low.

[Preparation of heat conductive pressure-sensitive adhesive laminate sheet]
Example 3
A filtrate (solid content concentration 22.0%) was produced in the same manner as in Example 1. Next, the filtrate was applied on a PET film having a thickness of 20 μm cut to 200 mm × 300 mm by using a bar coater so as to have a thickness of 400 μm.

Next, a laminate composed of a PET film and a filtrate coating film was placed in an oven and heated at 150 ° C. for 30 minutes. By evaporating the solvent from the filtrate by this solvent removal step, a heat conductive pressure sensitive adhesive layer having a thickness of 200 μm is formed on one surface of the PET film, and consists of a base material layer and a heat conductive pressure sensitive adhesive layer 1. A laminate was obtained.

Next, the filtrate is applied to the other surface of the PET film (the surface opposite to the surface on which the heat conductive pressure-sensitive adhesive layer 1 is laminated) using a bar coater so as to have a thickness of 400 μm. Was applied.

Next, the laminate composed of the heat conductive pressure-sensitive adhesive layer 1, the PET film, and the filtrate coating film was put into an oven and heated at 150 ° C. for 30 minutes. By this solvent removal step, the solvent is vaporized from the filtrate to form a heat-conductive pressure-sensitive adhesive layer 2 having a thickness of 200 μm on the other surface of the PET film, and a base layer that is an intermediate layer and a heat that is a front and back layer A heat conductive pressure-sensitive adhesive laminate sheet (F) comprising conductive pressure-sensitive adhesive layers 1 and 2 was obtained.

(Examples 4 to 6 and Comparative Examples 2 and 3)
Instead of the precursor composition Z1 of Table 2 used in Example 3, the composition of each substance used for the precursor composition was changed to the precursor composition Z2 or ZC1, and the thickness or composition of the base material layer was represented. A sheet according to Examples 4 to 6 and Comparative Examples 2 and 3 was produced in the same manner as Example 3 except for the changes shown in FIG.

As shown in Table 4, all of the sheets according to Examples 4 to 6 were excellent in air venting properties and had appropriate thermal conductivity. On the other hand, in the sheets according to Comparative Examples 2 and 3 in which the precursor composition serving as at least one of the heat conductive pressure-sensitive adhesive layers 1 and 2 does not contain a polyfunctional monomer, the polyfunctional In the surface on the side of the heat conductive pressure-sensitive adhesive layer made of a precursor composition that did not contain a functional monomer, the air bleedability was inferior.

1 Crosslinked polymer composition (A)
2 Solvent 3

Dispersion

4, 4a, 4b Polymer gel 5 Polymer gel-containing dispersion 6 Mesh 7 Filtrate 8 Substrate layer 9 Thermally conductive pressure sensitive

adhesive layer

10, 20, 14, 24, 34 Thermally conductive pressure sensitive adhesive Laminated sheet (F)
11

substrate

12, 22a, 22b, 32 heating element 13, 23 radiator

Claims

A method for producing a heat conductive pressure-sensitive adhesive laminate sheet (F) comprising a heat conductive pressure-sensitive adhesive layer and a base material layer,
The crosslinked polymer-containing composition (A) containing the thermally conductive filler (C1) and the (meth) acrylic acid ester polymer (A0) is immersed in a solvent and stirred to prepare a polymer gel-containing dispersion. A polymer gel-containing dispersion preparation step;
A filtration step of filtering the polymer gel-containing dispersion with a mesh having a predetermined opening to obtain a filtrate;
An application step of applying the filtrate to a predetermined thickness on one side of the base material layer;
Removing the solvent in the filtrate on the base material layer to obtain a thermally conductive pressure-sensitive adhesive layer; and
Including
The predetermined opening is 1.3 times or less of the predetermined thickness;
Gel fraction of post-filtered crosslinked polymer composition (H) obtained by drying the filtrate obtained by subjecting the crosslinked polymer composition (A) to the polymer gel-containing dispersion preparation step and the filtration step. Is 75% by mass or more,
Manufacturing method of heat conductive pressure-sensitive-adhesive laminated sheet (F).
A method for producing a heat conductive pressure-sensitive adhesive laminate sheet (F) comprising a heat conductive pressure-sensitive adhesive layer and a base material layer,
The crosslinked polymer-containing composition (A) containing the thermally conductive filler (C1) and the (meth) acrylic acid ester polymer (A0) is immersed in a solvent and stirred to prepare a polymer gel-containing dispersion. A polymer gel-containing dispersion preparation step;
A filtration step of filtering the polymer gel-containing dispersion with a mesh having a predetermined opening to obtain a filtrate;
A first application step of applying the filtrate to a predetermined thickness on one surface of the base material layer;
A first solvent removing step of removing the solvent in the filtrate applied to the one surface of the base material layer to obtain a heat conductive pressure-sensitive adhesive layer;
A second application step of applying the filtrate to the other surface of the base layer to the predetermined thickness;
A second solvent removal step of removing the solvent in the filtrate applied to the other surface of the base material layer to obtain a heat conductive pressure-sensitive adhesive layer;
Including
The predetermined opening is 1.3 times or less of the predetermined thickness;
Gel fraction of post-filtered crosslinked polymer composition (H) obtained by drying the filtrate obtained by subjecting the crosslinked polymer composition (A) to the polymer gel-containing dispersion preparation step and the filtration step. Is 75% by mass or more,
Manufacturing method of heat conductive pressure-sensitive-adhesive laminated sheet (F).
The crosslinked polymer-containing composition (A) is a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), a polyfunctional monomer (B1), In the precursor composition containing the thermally conductive filler (C1), at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1), a (meth) acrylic acid ester polymer (A1) and / or ( The pressure-sensitive adhesive laminated sheet (F) according to claim 1 or 2, which is obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from a (meth) acrylate monomer (α1). ) Manufacturing method.
The method for producing a heat conductive pressure-sensitive adhesive laminated sheet (F) according to any one of claims 1 to 3, wherein the predetermined opening of the mesh is 1000 µm or less.
A heat conductive pressure-sensitive adhesive laminate sheet (F) obtained by the method for producing a heat conductive pressure-sensitive adhesive laminate sheet (F) according to any one of claims 1 to 4.
An electronic device comprising the thermally conductive pressure-sensitive adhesive laminated sheet (F) according to claim 5.