JP2001288418A - Curable self-adhesive material, curable self-adhesive tape/sheet manufactured using the same and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable self-adhesive material exhibiting self-adhesive properties high enough to keep mutual positional relationship between adherends under temporary adhesion, curable by heating after temporary adhesion to exhibit high adhesive power, and moreover excellent in preservation stability and heat resistance, and to provide curable self-adhesive tape/sheet manufactured using the same and its manufacturing method. SOLUTION: The curable self-adhesive material comprises a photocurable self-adhesive mainly composed of an alkyl (meth)acrylate monomer, a polar group-containing monomer, an acrylic polymeric material bearing a photoreactive functional group and a photopolymerization initiator, and, admixed therewith, an epoxy resin and a cationic polymerization catalyst. This self-adhesive material is applied on a tape/sheet and subjected to polymerization by photoirradiation to give a curable self-adhesive tape/sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable pressure-sensitive adhesive material having a property of being cured after adhering to an adhesive object, a curable pressure-sensitive adhesive tape / sheet produced using the same, and a method for producing the same.

[0002]

2. Description of the Related Art With the high integration, high performance, high functionality, and miniaturization of computers and communication devices, printed wiring boards and ceramic module substrates used in these electronic devices are also becoming highly integrated. It is downsized.

In recent years, in industries such as the electric and electronic fields, products have been remarkably reduced in size, weight, and integration, and accordingly, adhesives and pressure-sensitive adhesives used for joining parts have high heat resistance. Demands for high adhesion, high reliability, etc. are increasing. In particular, from the viewpoint of improving workability and work environment, a tape- or sheet-like pressure-sensitive adhesive ("pressure-sensitive adhesive" is referred to as "adhesion") is used instead of the liquid adhesive. More and more various parts are joined.

[0004] In particular, in fixing electronic components, the adhesive has a high tackiness enough to maintain the mutual positional relationship of the bonded objects during the temporary bonding, and is hardened by heating after the temporary bonding, so that a high bonding force is obtained. There is a demand for the development of a curable pressure-sensitive adhesive tape / sheet having a property to have. In addition, with the miniaturization of parts and equipment, the demand for thinning is strict, and in order to improve the adhesion to the adherend, a flexible curable pressure-sensitive adhesive tape / sheet that does not use a support is developed. Is desired.

Conventionally, as a curable pressure-sensitive adhesive material, a material obtained by adding a reactive oligomer or a reactive monomer to a non-reactive or reactive pressure-sensitive adhesive polymer material, or a material obtained by adding an epoxy resin to an acrylic resin is known. Have been.

A curable pressure-sensitive adhesive material obtained by adding a reactive oligomer or a reactive monomer to a non-reactive or reactive pressure-sensitive adhesive polymer material is disclosed in JP-B-61-18591.
Japanese Patent Publication No. 1-46513 and Japanese Patent Publication No. 2-5791 describe such a photocurable adhesive material in which an epoxy resin is added to an acrylic resin.
2076, JP-A-7-2978, JP-A-9
It is described in -316398.

[0007]

However, the curable pressure-sensitive adhesive materials described in JP-B-61-18591, JP-B1-46513 and JP-B-2-5791 have a sufficient adhesive strength after curing. As a result of adding a large amount of a reactive oligomer or a reactive monomer to obtain a resin, the adhesive properties before curing, particularly, the holding power is reduced, and the relative position of the objects between the temporary bonding of a plurality of objects and the heat curing is reduced. There has been a possibility that a positional shift or separation between objects may occur.

On the other hand, if the addition amount of the reactive oligomer or the reactive monomer is reduced in order to improve the adhesive properties before curing, in particular, the holding power, the curability deteriorates and sufficient adhesive strength cannot be obtained. . As described above, no curable pressure-sensitive adhesive material having sufficiently high adhesiveness before curing and adhesiveness after curing has been developed.

In order to achieve both good adhesive properties before curing and good adhesive properties after curing, it has been studied to bond a plurality of unsaturated groups to side chains of the adhesive polymer material. However, there are some problems in the characteristics such as the synthetic surface and the storage stability (the liquid life after the preparation of the drug), and improvement thereof has been desired.

The photocurable pressure-sensitive adhesive materials described in JP-A-2-272076, JP-A-7-2978, and JP-A-9-316398 can be cured by the curable pressure-sensitive adhesive materials disclosed therein. The compatibility between good tackiness before and good adhesion after curing was not completely realized.

In general, when an adhesive film (tape or sheet) is produced, it is necessary to apply an adhesive liquid to one or both surfaces of the substrate, and in particular, from a thin film to a thick film (5 to 500 μm thick). It has been desired to develop a simple method for mass-producing the pressure-sensitive adhesive film up to). Also, there is a demand for the development of technology for mass-producing pressure-sensitive adhesive films having excellent storage stability, and in order to be able to adhere to adherends having various shapes, a flexible, so-called base material. The development of a non-adhesive tape / sheet was desired.

As described above, the conventional materials have good adhesiveness before curing and good adhesiveness after curing, have excellent storage stability, and are flexible.
It was difficult to obtain a sheet easily and stably.

An object of the present invention is to solve the problems of the above-mentioned conventional materials and techniques, to provide sufficiently excellent tackiness before curing and adhesion after curing, and also to provide storage stability and heat resistance. Another object of the present invention is to provide a curable pressure-sensitive adhesive material which is excellent in the above, a curable pressure-sensitive adhesive tape / sheet produced using the same, and a method for producing the same.

[0014]

DISCLOSURE OF THE INVENTION The curable pressure-sensitive adhesive material of the present invention comprises a (meth) acrylic acid alkyl ester monomer, a polar group-containing monomer, an acrylic high molecular weight material having a photoactive functional group, and photopolymerization. In a curable pressure-sensitive adhesive material comprising a photocurable pressure-sensitive adhesive component having an initiator as a main component and a thermosetting resin component, the weight-average molecular weight of the acrylic high-molecular material having a photoactive functional group is 200,000 to 3,000,000, The content of the photoactive functional group is 0.001 to 0.5 meq / g, and the thermosetting resin component is an epoxy resin and a cationic polymerization catalyst.

Further, the curable pressure-sensitive adhesive tape / sheet of the present invention has a constitution in which a pressure-sensitive adhesive layer made of the curable pressure-sensitive adhesive material obtained by photo-curing the photocurable pressure-sensitive adhesive component is provided on a substrate.

In the method for producing a curable pressure-sensitive adhesive tape / sheet according to the present invention, the curable pressure-sensitive adhesive material is coated on a sheet substrate to a thickness of 5 to 500 μm to form a curable pressure-sensitive adhesive layer. The photocurable pressure-sensitive adhesive component contained in the curable pressure-sensitive adhesive material layer is light-cured by light irradiation, and is produced.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In order to solve the above-mentioned problems, the present inventors have studied various materials and processes for producing a curable pressure-sensitive adhesive tape / sheet. Body, a polar group-containing monomer, a curable pressure-sensitive adhesive material composed of a photocurable pressure-sensitive adhesive component and a thermosetting resin component mainly containing an acrylic high-molecular weight material having a photoactive functional group and a photopolymerization initiator, The weight average molecular weight of the acrylic high molecular weight substance having a photoactive functional group is from 200,000 to 3
100,000, the content of the photoactive functional group is 0.001 to 0.
It was confirmed that the above object was achieved by using 5 meq / g and using a thermosetting resin component as an epoxy resin and a cationic polymerization catalyst.

Further, a pressure-sensitive adhesive layer comprising the curable pressure-sensitive adhesive material containing the light-curable pressure-sensitive adhesive component and the thermosetting resin component and light-curing the light-curable pressure-sensitive adhesive component is provided on a substrate. It was confirmed that the provided curable pressure-sensitive adhesive tape / sheet had excellent adhesive strength and high-temperature holding power, and exhibited excellent adhesive strength after thermosetting.

That is, by using the curable pressure-sensitive adhesive tape / sheet made of the curable pressure-sensitive adhesive material of the present invention, a bonding excellent in basic adhesive properties such as adhesive strength and holding power, and excellent in adhesive strength after heat treatment. Is obtained. In addition, adhesive tape
Since the sheet thickness can be reduced, and since there is no base material, the adhesiveness to the adherend is excellent, and bonding suitable for small electric / electronic parts and the like can be obtained.

The method for producing the curable pressure-sensitive adhesive material and the curable pressure-sensitive adhesive tape / sheet used in the present invention will be described below.

The acrylic high molecular weight material having a photoactive functional group is used to improve the heat resistance of the pressure-sensitive adhesive tape / sheet, particularly the properties such as high-temperature holding power, and to improve the workability such as coatability. Used to improve
The acrylic high molecular weight material having a photoactive functional group used in the present invention has a weight average molecular weight of 200,000 to 300.
Acrylic high molecular weight materials having a photoactive functional group content of 0.001 to 0.5 meq / g are preferred.

As a method for introducing the photoactive functional group into the acrylic high molecular weight compound, an isocyanate compound having a (meth) acryloyloxy group in the side chain of the acrylic high molecular weight compound (for example, 2 -Methacryloyloxyethyl isocyanate). In this way, an acrylic high molecular weight substance having a photoactive functional group such as a (meth) acryloyloxy group can be obtained. However, the introduction method is not particularly limited.

When the weight average molecular weight of the above-mentioned acrylic high molecular weight compound having a photoactive functional group is less than 200,000,
In order to obtain a high-viscosity adhesive composition of several thousands to several tens of thousands cP in consideration of coatability and the like, it is necessary to increase the amount of the acrylic high molecular weight material having a photoactive functional group. As a result, the adhesive tape has both excellent adhesive properties (specifically, adhesive strength of 3.5N / 10mm or more to a stainless steel substrate) and heat resistance (specifically, holding power at 150 ° C or more). No, not preferred. Further, when the weight average molecular weight is 30
When it is larger than 10,000, the pressure-sensitive adhesive tape is not particularly problematic in characteristics, but it is difficult to mass-produce an acrylic high molecular weight substance, which is not preferable.

When the content of the photoactive functional group of the acrylic high molecular weight product having a photoactive functional group is less than 0.001 meq / g, the high-temperature holding power of the pressure-sensitive adhesive tape deteriorates. When the content of the photoactive functional group is more than 0.5 meq / g, the adhesive strength of the pressure-sensitive adhesive tape becomes low, which is not preferable in any case. The amount of the acrylic polymer having a photoactive functional group in the pressure-sensitive adhesive composition is adjusted according to the desired pressure-sensitive adhesive properties and the viscosity at the time of coating. 5-
Used at 50% by weight.

The main component of the acrylic high molecular weight compound having a photoactive functional group is usually a copolymer of a (meth) acrylic acid alkyl ester monomer and a polar group-containing monomer, for example, an acrylic polymer. Copolymers of 2-ethylhexyl acrylate and 2-hydroxyethyl methacrylate, terpolymers of isooctyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate, and the like are used, but are not particularly limited thereto. Not something.

The alkyl (meth) acrylate monomer used in the present invention includes, for example, ethyl group, propyl group, butyl group, pentyl group, hexyl group, 2-ethylhexyl group, octyl group, Usually, esters of (meth) acrylic acid having an alkyl group having 20 or less carbon atoms, such as an isooctyl group, a nonyl group, an isononyl group, and a decyl group, are exemplified. The above-mentioned alkyl (meth) acrylate is used alone or in combination of two or more. In the present invention,
Part of the alkyl (meth) acrylate may be replaced with a copolymerizable monomer such as vinyl acetate.

The polar group-containing monomer used in the present invention includes acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, acrylonitrile, methacrylic acid. Ronitrile, N-vinyl-2
-Polymerizable unsaturated monomers having a polar group such as a carboxyl group, a hydroxyl group or an amino group in the molecule, such as pyrrolidone.

The compounding amount is 1 to 3 with respect to 99 to 70 parts by weight of the alkyl (meth) acrylate.
It is preferably 0 parts by weight. When the content of the polar group-containing monomer is less than 1 part by weight, the adhesive strength of the pressure-sensitive adhesive tape is reduced, and when the content is more than 30 parts by weight, the adhesive property of the pressure-sensitive adhesive tape at low temperatures is reduced, Either case is not preferred. The polar group-containing monomers described above are used alone or in combination of two or more.

As the above-mentioned photopolymerization initiator, a usual photopolymerization initiator used for radical photopolymerization such as a vinyl group or a (meth) acryloyloxy group is used. For example,
2,2-dimethoxy-1,2-diphenylethane-1-
Benzyldimethyl ketal compounds such as ON (Irgacure 651 from Ciba Specialty Chemicals), 1-hydroxycyclohexyl phenyl ketone (Irgacure 18 from Ciba Specialty Chemicals)
4), α-hydroxyketone compounds such as 2-hydroxy-2-methyl-1-phenylpropan-1-one (Darocur 1173 of Ciba Specialty Chemicals), 2-benzyl-2-dimethylamino-1- (4
Α-aminoketone compounds such as -morpholinophenyl) butanone-1 (Irgacure 369 from Ciba Specialty Chemicals) and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals) Irgacure 81
9) and the like, and bis (2,6-dimethoxybenzoyl) -2,4,
Bisacylphosphine oxides such as 4-trimethylpentylphosphine oxide and Darocure 117
1: 3 mixture of Irgacure 1700 with Ciba Specialty Chemicals, bisacylphosphine oxide such as bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and Irgacure 184 1: 1 mixture with Irgacure 185 (Ciba Specialty Chemicals)
0), benzoin ethyl ether compounds such as benzoin ethyl ether and benzoin isopropyl ether. In particular, a photopolymerization initiator such as a bisacylphosphine oxide-based compound that generates two or more active species (radicals) from one molecule of the photopolymerization initiator by light irradiation is desirable.

These photopolymerization initiators are preferably used in a proportion of 0.001 to 5 parts by weight based on 100 parts by weight of the photocurable pressure-sensitive adhesive. When the amount is less than 0.001 part by weight, it is difficult to complete the polymerization sufficiently, and when the amount is more than 5 parts by weight, the molecular weight of the obtained pressure-sensitive adhesive polymer becomes small, In particular, the holding power of the pressure-sensitive adhesive tape at high temperatures is reduced, which is not preferable in terms of pressure-sensitive adhesive properties.

As the thermosetting resin component used in the present invention, a commonly used epoxy resin is preferable, and a resin obtained by epoxidizing hydroxyl groups at both ends of bisphenol A (having a glycidyl group) is preferable. For example,
Epikote 815 and Epikote 8 made by Shell Chemical
28, epicoat 834, epicoat 1001, epicoat 1004, and the like. Further, as other epoxy resins, alicyclic epoxy resins, for example, Celloxide 2021 and Celloxide 20 manufactured by Daicel Chemical Industries, Ltd.
81, an alicyclic epoxy resin having two epoxy groups in one molecule such as celloxide 2083, and one epoxy group in one molecule such as M-100, A-200, and M-101 manufactured by Daicel Chemical Industries, Ltd. An alicyclic epoxy resin or the like may be used, or an epoxidized polybutadiene resin may be used. These are used alone or in a mixture of two or more.

These epoxy resins are preferably used in a proportion of 5 to 70 parts by weight based on 100 parts by weight of the photocurable adhesive component. If the amount is less than 5 parts by weight, the adhesive strength after heat curing is not sufficient,
When the amount is more than 70 parts by weight, it is difficult to impart a sufficient initial adhesive strength, and in any case, it is not practically preferable.

As the curing agent for the epoxy resin used in the present invention, a cationic polymerization catalyst which generates a Lewis acid upon heating is preferable. For example, San Aid SI-60L and San Aid SI-80L manufactured by Sanshin Chemical Industry Co., Ltd. Sun-Aid SI-100L, and CI-26 manufactured by Nippon Soda
24 and the like are used, but not particularly limited thereto. The addition amount is desirably 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

Further, about 0.001 to 5 parts by weight of a photopolymerizable compound such as a polyfunctional acrylic (methacrylic) monomer may be added to 100 parts by weight of the photocurable adhesive component of the present invention. As such a photopolymerizable compound,
Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate , Polypropylene glycol di (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate and the like.

The curable pressure-sensitive adhesive material for producing the curable pressure-sensitive adhesive tape / sheet of the present invention includes a tackifier such as a rosin-based resin, a terpene-based resin, or a petroleum resin, which is usually used for an acrylic resin. It may be added.

The curable pressure-sensitive adhesive material of the present invention may further contain commonly used additives such as a thickener, a thixotropic agent, and a filler. Examples of the thickener include acrylic rubber, epichlorohydrin rubber, and the like, and examples of the thixotropic agent include ultrafine silica (such as Aerosil 300 manufactured by Aerosil Japan). Examples of the filler include inorganic particles such as calcium carbonate, titanium dioxide, and silicon dioxide; organic particles such as nylon beads, acrylic beads, and silicone beads; inorganic hollow particles such as glass balloons and alumina balloons; acrylic balloons; and vinylidene chloride balloons. Organic hollow particles, polyester,
Organic or inorganic short fibers such as nylon, rayon, and glass are exemplified. These are added in order to improve mechanical properties such as stress relaxation of the pressure-sensitive adhesive tape / sheet, and are used within a range that does not impair photocurability and the like.

The above-mentioned curable pressure-sensitive adhesive material is in a liquid state, and is coated on a sheet substrate such as a polyester film which has been subjected to a release treatment by a roll coater or a die coater, and then cured by light irradiation to cure. The adhesive tape / sheet is obtained. When this photocurable pressure-sensitive adhesive material is polymerized, the polymerization reaction is inhibited by oxygen in the air or oxygen dissolved in the pressure-sensitive adhesive material. Light irradiation is performed in an atmosphere replaced with an active gas. A tin salt compound having a deoxidizing effect, such as stannous octoate or triisodecyl phosphite, or a phosphorus-based compound may be added to suppress the inhibition of curing by oxygen.

Hereinafter, the method for producing the curable pressure-sensitive adhesive tape / sheet of the present invention will be specifically described. However, the curable pressure-sensitive adhesive tape / sheet of the present invention is not limited to one manufactured by this method.

First, the above-mentioned alkyl (meth) acrylate monomer, the above-mentioned polar group-containing monomer, the above-mentioned acrylic polymer having a photoactive functional group, and the above-mentioned photopolymerization initiator are mixed in predetermined amounts. After mixing, the epoxy resin and the cationic polymerization catalyst are added in predetermined amounts, and sufficiently stirred and mixed to obtain a uniform curable pressure-sensitive adhesive material. At this time, the viscosity at 25 ° C. of the curable pressure-sensitive adhesive material is 1,000 to 50,000.
It is preferably 00 cP in terms of coating. The viscosity is adjusted according to the thickness required for the tape sheet.

If necessary, the above-mentioned curable pressure-sensitive adhesive material may be added with the above-mentioned polyfunctional (meth) acrylic monomer, thixotropic agent, filler and the like.
On a sheet substrate such as a polyester film subjected to a release treatment of the curable pressure-sensitive adhesive material thus produced, usually,
Coating is performed to a predetermined thickness of 5 to 500 μm. Next, under a nitrogen atmosphere, or under a condition in which a transparent polyester-coated film is stacked and air is blocked, the ultraviolet intensity at 365 nm is about 0.1 to 10 m using a black light or the like.
The curable pressure-sensitive adhesive layer is irradiated with ultraviolet rays of W / cm ² for 20 seconds to 5 minutes to photo-cur, separate the sheet substrate, and obtain a curable pressure-sensitive adhesive tape / sheet.

The curable pressure-sensitive adhesive tape / sheet of the present invention is obtained in this manner. When the tape / sheet is bonded to an adherend such as an electric / electronic part, it exhibits excellent adhesive properties when heated. .

[0042]

EXAMPLES The curable pressure-sensitive adhesive material of the present invention, the curable pressure-sensitive adhesive tape / sheet produced using the same, and the method for producing the same will now be described specifically with reference to Examples. However, the curable pressure-sensitive adhesive material of the present invention, the curable pressure-sensitive adhesive tape / sheet produced using the same, and the method for producing the same are not limited thereto. In the description of Examples and Comparative Examples, "parts" indicates parts by weight.

Example 1 2-ethylhexyl acrylate having a weight average molecular weight of 700,000 and a photoactive functional group content of 0.01 meq / g in 63 parts of 2-ethylhexyl acrylate and 7 parts of acrylic acid 30 parts of an acrylic high-molecular-weight polymer having as a main component, 0.05 parts of 1,6-hexanediol diacrylate, 0.3 parts of a photopolymerization initiator Irgacure 819 (Ciba Specialty Chemicals), an epoxy resin epicoat 834 ( Yuka Shell Epoxy Co., Ltd.) 20
Parts, and 0.6 parts of a cationic polymerization catalyst San-Aid SI-60L (Sanshin Chemical Industry Co., Ltd.) were added and mixed well.
A uniform curable pressure-sensitive adhesive material having a viscosity at 3,000C of 3,000 cP was obtained.

The curable pressure-sensitive adhesive material was subjected to a release treatment.
A 50 μm thick polyester film coated on a 0 μm thick polyester film by a comma coater, and subjected to a release treatment from above, is superimposed on the polyester film so that air bubbles do not enter.
Ultraviolet light having an intensity of 3 mW / cm ² at 365 nm was irradiated for 2 minutes using a black light to obtain a curable pressure-sensitive adhesive tape sheet having a thickness of 50 μm.

The adhesive force of the curable pressure-sensitive adhesive tape / sheet to the stainless steel plate was 4.6 N / 10 mm,
In the holding force test (load: 1 kg) at ℃ / 24 hours or 180 ° C / 1 hour, no displacement or drop was observed.
It showed excellent adhesiveness and heat resistance. The ball tack of the curable pressure-sensitive adhesive tape / sheet was 3 or less when the measurement angle was 30 °, and was 4 when the measurement angle was 20 °.

Next, using this curable pressure-sensitive adhesive tape / sheet, it was bonded to two stainless steel plates.
After measuring the shear adhesive force after heating for 1 minute, it was confirmed that the shear adhesive force before heating was 0.3 MPa but became 2 MPa after heating. From this, it was confirmed that the material of the present invention had a sufficiently high adhesive force during the temporary bonding and had a property of having a high adhesive force by heating after the temporary bonding. No significant change in properties was observed even after the curable pressure-sensitive adhesive tape / sheet was kept at 25 ° C./65% RH for 3 months.

Example 2 Isooctyl acrylate 63
Parts, 7 parts of acrylic acid, 30 parts of an acrylic high-molecular material mainly composed of 2-ethylhexyl acrylate having a weight average molecular weight of 800,000 and a photoactive functional group content of 0.02 meq / g, Irgacure 0.3 part of 1850 (Ciba Specialty Chemicals), 30 parts of Epoxy Resin Epicoat 828 (Yukaka Epoxy) and San Aid SI-80L of cationic polymerization catalyst (Sanshin Chemical Industry)
0.8 part was added and mixed well to obtain a uniform curable pressure-sensitive adhesive material having a viscosity of 4,000 cP at 25 ° C.

This curable pressure-sensitive adhesive material was subjected to a release treatment 5
A 50 μm thick polyester film coated on a 0 μm thick polyester film by a comma coater, and subjected to a release treatment from above, is superimposed on the polyester film so that air bubbles do not enter.
Irradiate with UV light of 365 mW / cm ² UV intensity at 365 nm for 3 minutes using a black light, 200 μm
A thick curable adhesive tape sheet was obtained.

The adhesive strength of the curable pressure-sensitive adhesive tape / sheet to the stainless steel plate was 6.0 N / 10 mm,
In the holding force test (load: 1 kg) at ℃ / 24 hours or 180 ° C / 1 hour, no displacement or drop was observed.
It showed excellent adhesiveness and heat resistance. The ball tack of the curable pressure-sensitive adhesive tape / sheet was 3 or less when the measurement angle was 30 °, and was 4 when the measurement angle was 20 °.

Next, using this curable pressure-sensitive adhesive tape / sheet, it was bonded to two stainless steel plates.
When the shear adhesive strength after heating for 5 minutes was measured, it was confirmed that the shear adhesive strength before heating was 0.4 MPa but became 5 MPa after heating. From this, it was confirmed that the material of the present invention had a sufficiently high adhesive force during the temporary bonding and had a property of having a high adhesive force by heating after the temporary bonding. Even when the curable pressure-sensitive adhesive tape / sheet was kept at 25 ° C./65% RH for 3 months, no change in the properties of the adhesive strength and the shear adhesive strength was observed.

Examples 3 to 9 In the same manner as in Examples 1 and 2, curable pressure-sensitive adhesive tapes / sheets were produced under the compositions and production conditions shown in Table 1. In Table 1, all photopolymerization initiators used were Irgacure 819 and 0.3 parts. The light irradiation conditions are as follows: UV intensity 3 mW / c
It was decided to irradiate ultraviolet rays of m ² for 3 minutes.

Table 2 shows the measurement results of the initial adhesive strength and the shear adhesive strength after heat treatment (heat treatment at 120 ° C. for 30 minutes) of these curable pressure-sensitive adhesive tapes / sheets. And excellent adhesiveness after heating. In addition, coatability when producing a curable adhesive tape / sheet,
The mass productivity such as film forming property and curability was also good. Also,
Even when the curable pressure-sensitive adhesive tape / sheet was kept at 25 ° C./65% RH for 3 months, no significant change in properties was observed.

[0053]

[Table 1]

[0054]

[Table 2] [Comparative Example 1] Acrylic high-molecular-weight polymer 30 having a weight average molecular weight of 700,000 and 2-ethylhexyl acrylate containing no photoactive functional group as a main component in 63 parts of 2-ethylhexyl acrylate and 7 parts of acrylic acid Part, 1,6-hexanediol diacrylate 0.05 part, and Irgacure 819 (Ciba Specialty Chemicals) 0.
3 parts were added and mixed well to obtain a uniform pressure-sensitive adhesive having a viscosity of 2,000 cP at 25 ° C.

This adhesive was applied on a 50 μm-thick polyester film which had been subjected to a release treatment.
Irradiation with ultraviolet light having an ultraviolet intensity of 3 mW / cm ² at 365 nm was performed for 2 minutes to obtain an adhesive tape sheet having a thickness of 50 μm.

The adhesive strength of the adhesive tape / sheet to the stainless steel plate is 5.0 N / 10 mm, and the ball tack is 3
Hereinafter, a holding force test at 40 ° C./24 hours (load: 1 kg)
Or 180 ° C / 1 hour holding force test (load: 1k
In g), no slippage or drop was observed, showing excellent adhesiveness and heat resistance. The ball tack of this adhesive tape / sheet is 3 or less when the measurement angle is 30 °, and the angle is 20 °.
Was 4.

Next, using this adhesive tape / sheet,
When the sheared adhesive strength after heating at 120 ° C. for 10 minutes was measured and the sheared adhesive strength before heating was 0.4 MPa, the sheared adhesive strength was 0.4 MPa even after heating.
5 MPa, and could not be said to show particularly excellent shear adhesion.

[0058]

As described above, the curable pressure-sensitive adhesive material of the present invention comprises an alkyl (meth) acrylate monomer, a polar group-containing monomer, and an acrylic high molecular weight material having a photoactive functional group. And a curable pressure-sensitive adhesive material comprising a photocurable pressure-sensitive adhesive component containing a photopolymerization initiator as a main component and a thermosetting resin component, wherein the weight average molecular weight of the acrylic high-molecular material having a photoactive functional group is 20. Since the content of the photoactive functional group is 0.001 to 0.5 meq / g and the thermosetting resin component is an epoxy resin and a cationic polymerization catalyst, a sufficiently high initial value. It has the property of having tackiness and having high adhesiveness by heat treatment, and also has excellent storage stability.

The curable pressure-sensitive adhesive tape / sheet of the present invention has a constitution in which a pressure-sensitive adhesive layer made of the curable pressure-sensitive adhesive material obtained by light-curing the photocurable pressure-sensitive adhesive component is provided on a substrate.
It has a sufficiently high initial tackiness, a property of having high adhesiveness by heat treatment, and also has excellent storage stability.

Further, the method for producing a curable pressure-sensitive adhesive tape / sheet of the present invention comprises the steps of: applying the curable pressure-sensitive adhesive material to a sheet substrate to a thickness of 5 to 500 μm to form a curable pressure-sensitive adhesive material layer; Since the photocurable pressure-sensitive adhesive component contained in the curable pressure-sensitive adhesive material layer is light-cured by light irradiation, the curable pressure-sensitive adhesive tape / sheet can be manufactured with good mass productivity.

Continued on the front page (72) Inventor Takahiro Sakai 3819 Nototo, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Inside Sliontec Co., Ltd. (72) Inventor Kazuo Nori 3819 Nototo, Tama-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Fionta (reference) 4J004 AA01 AA02 AA10 AA13 AA17 AB01 AB05 AB07 CA06 CC02 FA05 4J040 EC061 EC062 EC211 EC212 EC261 EC262 FA141 FA142 FA231 FA232 GA05 GA07 GA13 GA15 GA17 HB13 HB19 HC26 HD27 JA09 JB02 JB08 JB09 KA13 KA14 KA16 LA08 LA05 LA06

Claims (3)

[Claims] 1. A photocurable pressure-sensitive adhesive component comprising a (meth) acrylic acid alkyl ester monomer, a polar group-containing monomer, an acrylic high molecular weight material having a photoactive functional group, and a photopolymerization initiator as main components. A curable pressure-sensitive adhesive material comprising a thermosetting resin component, wherein the weight average molecular weight of the acrylic high molecular weight material having a photoactive functional group is 200,000 to 3,000,000, and the content of the photoactive functional group is 0.001-0.5 meq /
g, and wherein the thermosetting resin component comprises an epoxy resin and a cationic polymerization catalyst. 2. A curable pressure-sensitive adhesive tape / sheet provided with a pressure-sensitive adhesive layer comprising the curable pressure-sensitive adhesive material according to claim 1, wherein the photocurable pressure-sensitive adhesive component is light-cured on a substrate. 3. The curable pressure-sensitive adhesive material according to claim 1 is coated on a substrate to a thickness of 5 to 500 μm to form a curable pressure-sensitive adhesive material layer. A method for producing a curable pressure-sensitive adhesive tape / sheet, comprising photocuring a photocurable pressure-sensitive adhesive component.