KR20220073814A - adhesive sheet - Google Patents

Abstract

To provide a pressure-sensitive adhesive sheet that has high adhesiveness, is excellent in responsiveness to deformation and recovery, and is suitable for use as a member of a flexible electronic device. A pressure-sensitive adhesive sheet comprising a support and a pressure-sensitive adhesive composition layer formed on the support, wherein the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition layer includes (A) an isobutylene-based polymer having a crosslinked structure, (B) a plasticizer, and (C) a liquid polyolefin and/or liquid rubber.

Description

adhesive sheet

The present invention relates to an adhesive sheet, and more particularly, to an adhesive sheet suitable for a sealing sheet in a flexible electronic device, an adhesive sheet, an optically transparent adhesive sheet (OCA), and the like.

Conventionally, glass substrates have been mainly used for electronic devices such as flat panel displays (liquid displays, organic EL displays, electronic papers, etc.) and solar cells, but glass substrates are heavy and brittle. there is a problem. For this reason, in recent years, development of the flexible electronic device (hereinafter also simply abbreviated as "flexible device") which replaced the glass substrate with the flexible substrate which can be flexible and can bend is progressing actively.

In a flexible device, it becomes a subject that a member is damaged or peeling arises by the stress which arises when bending. In addition, shape recovery against deformation caused by bending is also required. Therefore, also in adhesive sheet materials such as sealing sheet, adhesive sheet, and OCA used for flexible devices, in addition to adhesiveness, it is required to have high responsiveness to deformation due to bending and excellent deformation recovery properties (Patent Document) One).

Japanese Patent Application Laid-Open No. 2018-526469

On the other hand, since the isobutylene-based polymer is generally excellent in adhesiveness, it is known that the pressure-sensitive adhesive composition containing the isobutylene-based polymer is useful as a material for an adhesive sheet. However, it cannot be said that it is necessarily satisfactory enough for use in a flexible electronic device, and development of the adhesive sheet suitable for flexible devices has been requested|required which has both adhesiveness, responsiveness to a deformation|transformation, and recovery|recovery property.

The present invention has been made in view of the above circumstances, and the problem to be solved is a pressure-sensitive adhesive sheet suitable for use as a member of a flexible electronic device, having high adhesiveness, and excellent responsiveness and recovery to deformation. is to provide

As a result of intensive research conducted by the present inventors to solve the above problems, in the pressure-sensitive adhesive sheet including the support and the pressure-sensitive adhesive composition layer, the pressure-sensitive adhesive composition layer includes an isobutylene-based polymer having a crosslinked structure, a plasticizer, a liquid polyolefin and By the adhesive sheet comprised by the adhesive composition containing/or liquid rubber, it discovered that the said subject was solved, and came to complete this invention. That is, the present invention includes those having the following characteristics.

[1] A pressure-sensitive adhesive sheet comprising a support and a pressure-sensitive adhesive composition layer formed on the support, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition layer,

(A) an isobutylene-based polymer having a crosslinked structure;

(B) a plasticizer and

(C) A pressure-sensitive adhesive sheet comprising liquid polyolefin and/or liquid rubber.

[2] The pressure-sensitive adhesive sheet according to [1], wherein the plasticizer is a plasticizer that is liquid at 25°C and has a viscosity at 25°C of less than 10,000 mPa·s.

[3] The pressure-sensitive adhesive sheet according to [1] or [2], wherein the liquid polyolefin and/or liquid rubber is a liquid polyolefin and/or liquid rubber that is liquid at 25°C and has a viscosity of 10,000 mPa·s or more at 25°C.

[4] The pressure-sensitive adhesive sheet according to any one of [1] to [3], wherein the isobutylene-based polymer having a cross-linked structure includes a cross-linked bond formed by reacting an epoxy group, a carboxylic acid group, and/or a carboxylic acid anhydride group.

[5] The pressure-sensitive adhesive sheet according to any one of [1] to [4], wherein the isobutylene-based polymer is a copolymer of isobutylene and isoprene.

[6] Any one of [1] to [5], wherein the isobutylene-based polymer having a crosslinked structure is a reaction product of an isobutylene-based polymer having an epoxy group and an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group The adhesive sheet described in .

[7] The pressure-sensitive adhesive sheet according to any one of [1] to [6], wherein the pressure-sensitive adhesive composition contains 40 to 80 mass% of the isobutylene-based polymer having a crosslinked structure with respect to 100 mass% of the nonvolatile component of the pressure-sensitive adhesive composition. .

[8] The pressure-sensitive adhesive sheet according to any one of [1] to [7], wherein the pressure-sensitive adhesive composition contains 10 to 45 mass% of a plasticizer with respect to 100 mass% of the nonvolatile component of the pressure-sensitive adhesive composition.

[9] The adhesive sheet according to any one of [1] to [7], wherein the pressure-sensitive adhesive composition contains 10-45 mass% of liquid polyolefin and/or liquid rubber with respect to 100 mass% of nonvolatile components of the pressure-sensitive adhesive composition.

[10] The adhesive sheet according to any one of [1] to [9], which is for a flexible electronic device.

[11] The adhesive sheet according to [10], wherein the flexible electronic device is a flexible organic EL device or a flexible solar cell device.

[12] (A) an isobutylene-based polymer having a crosslinked structure;

(B) a plasticizer and

(C) A pressure-sensitive adhesive composition comprising liquid polyolefin and/or liquid rubber.

[13] (A') an isobutylene-based polymer having a functional group capable of forming a crosslinked structure;

(A'') an isobutylene-based polymer and/or a crosslinking agent having a functional group capable of forming a cross-linked structure by reacting with the functional group of the isobutylene-based polymer having a functional group capable of forming the cross-linked structure;

(B) a plasticizer and

(C) A pressure-sensitive adhesive composition comprising liquid polyolefin and/or liquid rubber.

[14] (A-1) an isobutylene-based polymer having an epoxy group;

(A-2) an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group;

(B) a plasticizer and

(C) A pressure-sensitive adhesive composition containing liquid polyolefin and/or liquid rubber.

[15] A method for producing a pressure-sensitive adhesive sheet, comprising the step of applying the pressure-sensitive adhesive composition according to [13] or [14], which is in the form of a varnish, onto a support, and heat-drying to form a layer of the pressure-sensitive adhesive composition having a crosslinked structure formed thereon.

[16] The pressure-sensitive adhesive composition according to [14], which is in the form of a varnish, is coated on a support and dried by heating, (A-1) an epoxy group of an isobutylene-based polymer having an epoxy group, (A-2) a carboxylic acid group and/or a carboxylic acid anhydride A method for producing a pressure-sensitive adhesive sheet, comprising the step of forming a pressure-sensitive adhesive composition layer having a crosslinked structure formed thereon by reaction with a carboxylic acid group and/or a carboxylic acid anhydride group of an isobutylene-based polymer having a group.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in adhesiveness, and it is excellent also in the responsiveness to a deformation|transformation and recovery|restorability, and it can provide the adhesive sheet suitable for flexible electronic devices.

Hereinafter, the present invention will be described based on preferred embodiments thereof.

The pressure-sensitive adhesive sheet of the present invention includes a support and a pressure-sensitive adhesive composition layer formed on the support. The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition layer,

(A) an isobutylene-based polymer having a crosslinked structure;

(B) a plasticizer and

(C) contains liquid polyolefin and/or liquid rubber.

<(A) isobutylene polymer having crosslinked structure>

The crosslinked structure in the isobutylene-based polymer having a crosslinked structure used in the present invention (hereinafter also referred to as component (A)) is not particularly limited, and for example, crosslinked consisting of an epoxy group, a carboxylic acid group and/or a carboxylic acid anhydride group. structure, a crosslinked structure composed of an epoxy group and an amino group, a crosslinked structure composed of a hydroxyl group and an isocyanate group, a crosslinked structure composed of an alkoxysilyl group, a crosslinked structure composed of an acryloyl group, and the like. Among these, the crosslinked structure which consists of an epoxy group, a carboxylic acid group, and/or a carboxylic acid anhydride group from a viewpoint of an adhesive improvement, an optical characteristic improvement, and a moisture permeability fall is preferable. That is, the isobutylene-based polymer having a crosslinked structure used in the present invention preferably includes a crosslinked bond formed by reacting an epoxy group, a carboxylic acid group and/or a carboxylic acid anhydride group.

The isobutylene-based polymer having a crosslinked structure that can be used in the present invention is not particularly limited as long as it has a crosslinked structure and has an isobutylene skeleton. Polyisobutylene which is a homopolymer of isobutylene may be sufficient as an isobutylene-type polymer, and copolymers, such as a random copolymer and a block copolymer, may be sufficient as it. As a copolymer, the copolymer of isobutylene-isoprene, the copolymer of isobutylene-n-butene, the copolymer of isobutylene-butadiene, etc. are mentioned. The isobutylene polymer is preferably polyisobutylene and isobutylene/isoprene copolymer, particularly preferably isobutylene/isoprene copolymer, from the viewpoints of adhesiveness and temperature stability of the elastic modulus. As for the isobutylene-type polymer which has a crosslinked structure in this invention, only 1 type may be used and may use 2 or more types together.

The number average molecular weight of the isobutylene-based polymer having a crosslinked structure is not particularly limited, but from the viewpoint of bringing about good coatability of the varnish of the pressure-sensitive adhesive composition and good compatibility with other components in the pressure-sensitive adhesive composition, 1,000,000 or less is preferable, and 750,000 or less More preferably, 500,000 or less, still more preferably 400,000 or less, still more preferably 300,000 or less, particularly preferably 200,000 or less, and most preferably 150,000 or less. On the other hand, the number average molecular weight is preferably 1,000 or more, and more than 3,000 or more, from the viewpoint of preventing bouncing during application of the varnish of the adhesive composition, expressing the moisture permeability resistance of the adhesive composition layer to be formed, and improving mechanical strength. Preferably, 5,000 or more are still more preferable, 10,000 or more are still more preferable, 30,000 or more are still more preferable, and 50,000 or more are particularly preferable. In addition, the number average molecular weight in this invention is measured by the gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight by the GPC method uses LC-9A/RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P/K-804L/K-804L manufactured by Showa Denko as a column. , can be measured at a column temperature of 40°C using toluene or the like as a mobile phase, and calculated using a standard polystyrene calibration curve.

There is no restriction|limiting in particular content of (A) component in the adhesive composition of this invention. However, when there are many components (A), adhesiveness tends to fall, and from a viewpoint of maintaining sufficient adhesiveness, 80 mass % or less is preferable with respect to 100 mass % of non-volatile components of an adhesive composition, and the said content is 75 mass % or less is more preferable, 70 mass % or less is still more preferable, 65 mass % or less is still more preferable, and 60 mass % or less is especially preferable. On the other hand, from the viewpoint of improving crosslinking density and improving strain recovery, the content is preferably 15% by mass or more, more preferably 20% by mass or more, with respect to 100% by mass of nonvolatile components in the pressure-sensitive adhesive composition, 25 mass % or more is still more preferable, 30 mass % or more is still more preferable, 35 mass % or more is still more preferable, and 40 mass % or more is especially preferable.

One embodiment of this invention WHEREIN: As for content of (A) component in the adhesive composition of this invention, 15-80 mass % is preferable with respect to 100 mass % of non-volatile components of an adhesive composition, and 25-70 mass % is more preferable, and 35-60 mass % is still more preferable. Another embodiment of this invention WHEREIN: Content of (A) component in the adhesive composition of this invention becomes like this with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 40-80 mass %.

The isobutylene-type polymer which has a crosslinked structure can be manufactured by the following method, for example.

(1) an isobutylene-based polymer having a functional group capable of forming a crosslinked structure (one type or two or more) is reacted with the functional group to an isobutylene-based polymer having a functional group capable of forming a crosslinked structure (one type or 2 or more types).

(2) An isobutylene-based polymer (one or two or more) having a functional group capable of forming a crosslinked structure is reacted with a crosslinking agent (one or two or more) to crosslink it.

Examples of the functional group capable of forming a crosslinked structure include an epoxy group, a carboxylic acid group, a carboxylic acid anhydride group, an amino group, a hydroxyl group, an isocyanate group, an alkoxysilyl group, and an acryloyl group. The functional group capable of forming a crosslinked structure by reacting with the functional group is, for example, a carboxylic acid group or a carboxylic acid anhydride group when the functional group capable of forming a crosslinked structure is an epoxy group, and an epoxy group in the case of a carboxylic acid group or a carboxylic acid anhydride group. . The crosslinking agent is not particularly limited as long as it reacts with a functional group capable of forming a crosslinked structure to form a crosslinked structure, and examples thereof include a polyfunctional epoxy compound and the like.

In method (1), as a combination of a functional group capable of forming a crosslinked structure and a functional group capable of reacting with the functional group to form a crosslinked structure, a combination of an epoxy group, a carboxylic acid group or a carboxylic acid anhydride group, a combination of an epoxy group and an amino group; A combination of a hydroxyl group and an isocyanate group, alkoxysilyl groups, acryloyl groups, methacryloyl groups, etc. are mentioned, but from the viewpoint of improving adhesion, improving optical properties, and lowering moisture permeability, an epoxy group, a carboxylic acid group, or a carboxylic acid anhydride group A combination of

In the method (1), the isobutylene-based polymer having a functional group capable of forming a crosslinked structure and the isobutylene-based polymer having a functional group capable of forming a crosslinked structure by reacting with the functional group may be the same. That is, isobutylene polymers having a functional group capable of forming a crosslinked structure and a functional group capable of forming a crosslinked structure by reacting with the functional group may be reacted.

In method (2), a carboxylic acid anhydride group is preferable as a functional group which can form a crosslinked structure from a viewpoint of the improvement of strain recovery property and an optical characteristic, and a polyfunctional epoxy compound is preferable as a crosslinking agent.

In a preferred embodiment of the present invention, the isobutylene-based polymer having a crosslinked structure is a reaction product of an isobutylene-based polymer having an epoxy group and an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group.

The amount ratio in the reaction of the isobutylene polymer having an epoxy group and the isobutylene polymer having a carboxylic acid group and/or a carboxylic acid anhydride group is not particularly limited as long as an appropriate crosslinked structure can be formed, but an epoxy group, a carboxylic acid group and/or a carboxylic acid group The molar ratio of the anhydride group (epoxy group: carboxylic acid group and/or carboxylic acid anhydride group) is preferably 100:10 to 100:200, more preferably 100:50 to 100:150, particularly preferably 100:90 to 100 :110.

<(A-1) Isobutylene-based polymer having an epoxy group>

The isobutylene-based polymer having an epoxy group used in the present invention (hereinafter also referred to as component (A-1)) is, for example, glycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether. , an unsaturated compound having an epoxy group, such as allyl glycidyl ether, and is obtained by graft-modifying an isobutylene-based polymer under radical reaction conditions. Moreover, you may make it radical copolymerize the unsaturated compound which has an epoxy group with an olefin etc.

0.05-10 mmol/g is preferable and, as for the density|concentration of the epoxy group in the isobutylene-type polymer which has an epoxy group, 0.1-5 mmol/g is more preferable. Epoxy group concentration is calculated|required from the epoxy equivalent obtained based on JISK7236-1995.

The number average molecular weight of the isobutylene-based polymer having an epoxy group is preferably 20,000 to 160,000, more preferably 30,000 to 140,000, particularly preferably 40,000 to 120,000 from the viewpoint of bending resistance and the like.

<(A-2) Isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group>

As the isobutylene polymer (hereinafter also referred to as (A-2) component) having a carboxylic acid group and/or a carboxylic acid anhydride group used in the present invention, for example, ER641, ER661 (manufactured by Seiko PMC), Unistol P801, P802 (made by Mitsui Chemicals), Surfren P1000 (made by Mitsubishi Chemical), etc. are mentioned. The isobutylene-based polymer having a carboxylic acid group is obtained, for example, by graft-modifying an isobutylene-based polymer under radical reaction conditions. Examples of the carboxylic acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, and a group derived from glutaric anhydride. The carboxylic acid anhydride group may have 1 type or 2 or more types. The isobutylene-based polymer having a carboxylic acid anhydride group is, for example, an unsaturated compound having a carboxylic acid anhydride group, and is obtained by graft-modifying the isobutylene-based polymer under radical reaction conditions. Moreover, you may make it radical copolymerize the unsaturated compound which has a carboxylic acid anhydride group with an isobutylene type polymer.

0.05-10 mmol/g is preferable and, as for the density|concentration of the carboxylic acid group and/or carboxylic acid anhydride group in the isobutylene-type polymer which has a carboxylic acid group and/or a carboxylic acid anhydride group, 0.1-5 mmol/g is more preferable. The concentration of the carboxylic acid group and/or the carboxylic acid anhydride group is obtained from the value of the acid value defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of the resin according to the description of JIS K 2501.

The number average molecular weight of the isobutylene polymer having a carboxylic acid group and/or a carboxylic acid anhydride group is preferably 1,000 to 150,000, more preferably 10,000 to 100,000, particularly preferably 30,000 to 80,000 from the viewpoint of bending resistance.

<(B) Plasticizer>

The pressure-sensitive adhesive composition of the present invention contains a plasticizer (hereinafter, also referred to as (B) component) for the purpose of further improving the responsiveness to deformation and adhesiveness. The plasticizer in the present invention is liquid at 25°C from the viewpoint of exhibiting a function as a plasticizer, and a plasticizer having a viscosity at 25°C of less than 10,000 mPa·s is used. The viscosity of the plasticizer is preferably 5,000 mPa·s or less, more preferably 2,000 mPa·s or less, still more preferably 1,000 mPa·s or less. Examples of the plasticizer include phthalic acid ester, adipic acid ester, phosphoric acid ester, trimellitic acid ester, sulfonic acid ester, petroleum oil, liquid polyolefin, liquid polybutadiene, polyol polyester, animal oil, Plasticizers, such as vegetable oil, are mentioned. You may use a plasticizer in combination of 2 or more type. In addition, the viscosity of the plasticizer in this invention can be measured with a vibration type viscometer or an E-type viscometer. In this case, the vibratory viscometer is suitably used for measuring the viscosity of a plasticizer in a relatively low-viscosity region (for example, 1,000 mPa·s or less). As a commercially available viscometer, the Vibration type viscometer (trade name: VISCOMATE MODEL VM-10A) by Seconic Co., Ltd., E-type viscometer (brand name: RE85H) by Toki Sangyo Co., Ltd. etc. are mentioned, for example.

Examples of the phthalic acid ester plasticizer include dioctyl phthalate (DOP) and dibutyl phthalate (DBP). As an adipic acid ester plasticizer, adipic acid dioctyl, adipic acid propylene glycol polyester, adipic acid butylene glycol polyester, etc. are mentioned, for example. Examples of the phosphate ester plasticizer include triclecil phosphate and trioctyl phosphate. As a trimellitic acid ester plasticizer, trimellitic acid trioctyl etc. are mentioned, for example. As a sulfonic acid ester plasticizer, alkylsulfonic acid ester etc. are mentioned, for example.

As petroleum oil, paraffin oil (liquid paraffin), naphthenic oil, aromatic oil etc. are mentioned, for example. Examples of the liquid polyolefin include liquid polybutene and ethylene-α-olefin cool oligomer. As polyol polyester, diethylene glycol dibenzoate, pentaerythritol ester, etc. are mentioned, for example.

As animal oil, squalane, squalene, etc. are mentioned, for example. Examples of the vegetable oil include olive oil, camellia oil, castor oil, tall oil, peanut oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, palm oil and the like.

Commercially available plasticizers include, for example, mesamoll (manufactured by LANXESS, Inc.), mesamoll2 (manufactured by LANXESS), BXA-N (manufactured by Daihachi Chemical Corporation), oxygen sizer DOA (manufactured by Shin-Nippon Rika Corporation), oxygen Sizer DINA (made by New Nippon Rica), oxygen sizer DIDA (made by Nippon Rica), etc. are mentioned.

Commercially available castor oil derivatives, such as hydrogenated castor oil A (trade name), CO-FA (trade name), DCO-FA (trade name), Rixizer S4 (trade name), and Rixizer C-101 (brand name) manufactured by Itosei Oil Co., Ltd. and Rixizer GR-310 (trade name); Brownon BR-410 (trade name), Brownon BR-410 (brand name), Brownon BR-430 (brand name), Brownon BR-450 (brand name), Brownon CW-10 (brand name) manufactured by Aoki Yushiko Co., Ltd. , Brownon RCW-20 (trade name), Brownon RCW-40 (trade name), Brownon RCW-50 (trade name) and Brownon RCW-60 (trade name), and Nichiyu Corporation Custer Wax A (trade name), New Sizer 510R (brand name), Sakura stearate (brand name), castor hydrogenated fatty acid (brand name), NAA-34 (brand name), NAA-160 (brand name), NAA-175 (brand name), etc. are mentioned.

As a plasticizer used for this invention, a phthalic acid ester type plasticizer is preferable, and dioctyl phthalate is especially preferable. Moreover, as a phthalic acid ester plasticizer, a thing with a low molecular weight from an adhesive viewpoint is preferable, and it is 200-3,000 in terms of a weight average molecular weight, Furthermore, it is preferable that it is the range of 300-1,000. In addition, "liquid phase" is the state of a plasticizer in room temperature (25 degreeC) here.

Although content in particular of (B) component in the adhesive composition of this invention is not restrict|limited, 50 mass % or less is preferable with respect to 100 mass % of non-volatile components of an adhesive composition from a viewpoint of mechanical properties, such as tensile strength, 40 mass % or less is more preferable, and 30 mass % or less is still more preferable. On the other hand, from the viewpoint of improving the tack, its content is preferably 2% by mass or more, more preferably 4% by mass or more, still more preferably 5% by mass or more, with respect to 100% by mass of the nonvolatile component of the pressure-sensitive adhesive composition, 10 mass % or more is especially preferable.

In one embodiment of this invention, content of (B) component in the adhesive composition of this invention is with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 5-30 mass %, More preferably, It is 10-25 mass %. Another embodiment of this invention WHEREIN: Content of (B) component in the adhesive composition of this invention becomes like this with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 10-45 mass %.

<(C) Liquid polyolefin and/or liquid rubber>

The pressure-sensitive adhesive composition of the present invention contains liquid polyolefin and/or liquid rubber (hereinafter, also referred to as component (C)) for the purpose of further enhancing adhesion. As the liquid polyolefin and/or liquid rubber used in the present invention, the component (A) or the component constituting the component (A) (for example, the component (A-1) (isobutylene-based polymer having an epoxy group), ( A-2) A material that does not react with a component (isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group), etc.) (i.e., does not have a functional group that reacts with an epoxy group, a carboxylic acid group, or a carboxylic acid anhydride group) is used. The component (C) is a liquid at 25°C and a viscosity obtained by dividing the dynamic viscosity measured by a dynamic viscoelasticity measuring device at 25°C by the density of 10 Pa·s (10,000 mPa·s) or more is used. (C) The viscosity of the component is preferably 20 Pa·s or more, more preferably 50 Pa·s or more, still more preferably 100 Pa·s or more, still more preferably 500 Pa·s or more, still more preferably 1,000 more than Pa·s. (C) As the component, for example, synthetic liquid oil, rubber of C5 petroleum raw material oil polymer, polybutene, polyisobutylene, polyisoprene, polypropene, polyterpene, polybutadiene or copolymers and hydrogenated derivatives thereof and the like. (C) As for a component, the thing of 2,000-150,000 of weight average molecular weights (Mw) is used preferably, and the thing of 10,000-50,000 is used more preferably. In addition, the weight average molecular weight in this invention is measured by gel permeation chromatography. (C) The kinematic viscosity of component is measured with a dynamic viscoelasticity measuring apparatus, and a commercially available dynamic viscoelasticity measuring apparatus includes, for example, a rheometer manufactured by TA Instruments (trade name: DISCOVERY HR-2).

Synthetic liquid oils are low-viscosity oligomers that are constantly liquid monoolefins, isoparaffins or paraffins. Commercially available liquid polybutene, polyisobutylene, polyisoprene, polybutadiene, polyisoprene available as LIR30 and LIR50 from Kuraray, hydrogenated polyisoprene available as LIR290, INDOPOL H-1500, H-1900, H- from Ineos 2100, H-6000, polybutenes available under the names H-18000, polybutenes available under the names Niseki polybutene HV-300, HV-1900, SV-7000 from JXTG Energi, OPPANOL B10, B12 from BASF, polyisobutylene available under the names B14 and B15; and polybutadiene available from Nippon Soda under the names of B-3000 and BI-3000.

The content of component (C) in the pressure-sensitive adhesive composition of the present invention is not particularly limited, but component (C) tends to decrease the strain recovery rate, and from the viewpoint of maintaining the strain recovery rate, relative to 100% by mass of the nonvolatile component of the pressure-sensitive adhesive composition , 40 mass % or less is preferable, 35 mass % or less is more preferable, and 25 mass % or less is still more preferable. On the other hand, from a viewpoint of maintaining adhesiveness, 5 mass % or more is preferable with respect to 100 mass % of non-volatile components of an adhesive composition, as for this content, 7 mass % or more is more preferable, 10 mass % or more is still more preferable.

In one embodiment of the present invention, the content of component (C) in the pressure-sensitive adhesive composition of the present invention is preferably 5 to 40 mass% with respect to 100 mass% of the non-volatile component of the pressure-sensitive adhesive composition, more preferably It is 10-25 mass %. Another embodiment of this invention WHEREIN: Content of (C)component in the adhesive composition of this invention becomes like this with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 10-45 mass %.

<(D) curing agent and/or curing accelerator>

The pressure-sensitive adhesive composition of the present invention may further contain a curing agent and/or a curing accelerator (hereinafter, also referred to as (D) component) from the viewpoint of improving the curing performance of the pressure-sensitive adhesive composition. (D) You may use a component in combination of 2 or more type. Even if component (D) is the same compound, it may function as a hardening|curing agent by a system, or may function as a hardening accelerator.

(D) Examples of the curing agent in the component include an ionic liquid, an imidazole compound, a tertiary amine compound, a dimethylurea compound, an amine adduct compound, an organic acid dihydrazide compound, an organic phosphine compound, and a dicyandi compound. and amide compounds, primary/secondary amine compounds, phenol compounds, and thiol compounds.

(D) As a hardening accelerator in component, an ionic liquid, an imidazole compound, a tertiary amine compound, a dimethylurea compound, an amine adduct compound, an organic phosphine compound, a quaternary ammonium salt etc. are mentioned, for example.

As an ionic liquid as a hardening|curing agent and/or hardening accelerator in this invention, the thing of Unexamined-Japanese-Patent No. 2016-186843 is mentioned, for example. Specific examples of the ionic liquid include 1-butyl-3-methylimidazolium lactate, tetrabutylphosphonium-2-pyrrolidone-5-carboxylate, tetrabutylphosphonium acetate, and tetrabutylphosphoniumdecano. Eate, tetrabutylphosphonium trifluoroacetate, tetrabutylphosphonium α-lipoate, tetrabutylphosphonium formate, tetrabutylphosphonium lactate, bis(tetrabutylphosphonium) tartrate, tetrabutylphosphonate hippurate Phonium salt, N-methylhypuronate tetrabutylphosphonium salt, benzoyl-DL-alanine tetrabutylphosphonium salt, N-acetylphenylalanine tetrabutylphosphonium salt, 2,6-di-tert-butylphenol tetrabutylphosphonium salt Inium salt, L-aspartic acid monotetrabutyl phosphonium salt, glycine tetrabutyl phosphonium salt, N-acetylglycine tetrabutyl phosphonium salt, 1-ethyl-3-methylimidazolium lactate, 1-ethyl-3-methyl Midazolium acetate, 1-ethyl-3-methylimidazolium formic acid salt, 1-ethyl-3-methylimidazolium hipfuric acid salt, 1-ethyl-3-methylimidazolium salt of N-methyl hipfuric acid; Bis tartrate (1-ethyl-3-methylimidazolium) salt, N-acetylglycine 1-ethyl-3-methylimidazolium salt, etc. are mentioned, Tetrabutylphosphoniumdecanoate, N-acetylglycinetetra Butyl phosphonium salt, 1-ethyl-3-methylimidazolium acetate, formic acid 1-ethyl-3-methylimidazolium salt, hipfuric acid 1-ethyl-3-methylimidazolium salt, N-methylhipfur Acid 1-ethyl-3-methylimidazolium salt is preferred.

Examples of the imidazole compound as the curing agent and/or curing accelerator in the present invention include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, and 2-ethyl-4-methyl. Imidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2 -Undecylimidazolium trimellitate, 2,4-diamino-6-(2'-undecylimidazolyl-(1'))-ethyl-s-triazine, 2-phenyl-4,5- Bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, 2-dodecylimidazole, 2-heptadecyl Imidazole, 1,2-dimethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1) ')-ethyl-s-triazine, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazineisocyanuric acid adduct, etc. are mentioned. Specific examples of the imidazole compound include Curesol 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW , 2MZ-A, and 2MA-OK (all manufactured by Shikoku Kasei Kogyo) and the like.

As the tertiary amine compound as the curing agent and/or curing accelerator in the present invention, for example, DBN (1,5-diazabicyclo[4.3.0]non-5-ene), DBU (1,8-dia Java bicyclo [5.4.0] undeca-7-ene), 2-ethylhexanoate of DBU, phenol salt of DBU, p-toluenesulfonate of DBU, U-CAT SA 102 (manufactured by San Apro: Octyl of DBU) acid), DBU-organic acid salts such as formate salts of DBU, 2,4,6-tris(dimethylaminomethyl)phenol (TAP), and the like.

Examples of the dimethylurea compound as the curing agent and/or curing accelerator in the present invention include DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea), U-CAT3512T (manufactured by San Apro Corporation). Aliphatic dimethylurea, such as aromatic dimethylurea, such as U-CAT3503N (made by San Apro Corporation), etc. are mentioned. Among them, aromatic dimethylurea is preferably used from the viewpoint of curability.

As an amine adduct compound as a hardening|curing agent and/or hardening accelerator in this invention, the epoxy adduct compound etc. which are obtained by stopping the addition reaction of tertiary amine to an epoxy resin midway are mentioned, for example. Specific examples of the amine adduct compound include Amicure PN-23, Amicure MY-24, Amicure PN-D, Amicure MY-D, Amicure PN-H, Amicure MY-H, Amicure PN-31, Amicure PN-40, Amicure PN-40J (all are made by Ajinomoto Fine Techno), etc. are mentioned.

As an organic acid dihydrazide type compound as a hardening|curing agent in this invention, Amicure VDH-J, Amicure UDH, Amicure LDH (all made by Ajinomoto Fine Techno) etc. are mentioned, for example.

As the organic phosphine compound as the curing agent and/or curing accelerator in the present invention, for example, triphenylphosphine, tetraphenylphosphoniumtetra-p-tolylborate, tetraphenylphosphoniumtetraphenylborate, tri-tert-butyl Phosphonium tetraphenyl borate, (4-methylphenyl) triphenyl phosphonium thiocyanate, tetraphenyl phosphonium thiocyanate, butyl triphenyl phosphonium thiocyanate, triphenyl phosphine triphenyl borane, etc. are mentioned. Specific examples of the organic phosphine compound include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, and TPP-S (manufactured by Hoko Chemical Co., Ltd.).

As a dicyandiamide compound as a hardening|curing agent in this invention, dicyandiamide is mentioned, for example. Specific examples of the dicyandiamide compound include dicyandiamide finely pulverized products DICY7 and DICY15 (both manufactured by Mitsubishi Chemical Corporation).

Examples of the primary and secondary amine compounds as the curing agent in the present invention include diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, which are aliphatic amines; 1,3-bisaminomethylcyclohexane, propylenediamine, diethylaminopropylamine, bis(4-aminocyclohexyl)methane, norbornenediamine, 1,2-diaminocyclohexane, etc., N- which is an alicyclic amine Aminoethylpiperazine, 1,4-bis(3-aminopropyl)piperazine, etc., aromatic amines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane , diaminodiphenylsulfone, diethyltoluenediamine, and the like. Specific examples of the primary and secondary amine compounds include Kayahard A-A (manufactured by Nippon Kayaku Co., Ltd.: 4,4'-diamino-3,3'-dimethyldiphenylmethane).

As a phenolic compound as a hardening|curing agent in this invention, For example, a triazine skeleton containing phenolic hardening|curing agent, a triazine skeleton containing phenol novolak hardening|curing agent, MEH-7700, MEH-7810, MEH-7851 (made by Meiwakasei Co., Ltd.) , NHN, CBN, GPH (manufactured by Nihon Kayaku Corporation), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (manufactured by Toto Kasei Corporation), and TD2090 (manufactured by DIC Corporation). Specific examples of the triazine skeleton-containing phenolic curing agent include LA3018 (manufactured by DIC Corporation). Specific examples of the triazine skeleton-containing phenol novolac curing agent include LA7052, LA7054, and LA1356 (manufactured by DIC Corporation).

Examples of the thiol-based compound as the curing agent in the present invention include trimethylolpropanetris(3-mercaptopropionate), trimethylolpropanetris(3-mercaptobutyrate), and trimethylolethanetris(3-mercapto). butyrate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]- Isocyanurate, tris(3-mercaptopropyl)isocyanurate, 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyethyl )-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril, and the like. have. As a commercial item, Yodo Chemical Corporation OTG, EGTG, TMTG, PETG, 3-MPA, TMTP, PETP, Sakai Chemical Corporation TEMP, PEMP, TEMPIC, DPMP, Showa Denko Corporation PE-1, BD -1, NR-1, TPMB, TEMB, TS-G manufactured by Shikoku Kasei Co., Ltd., etc. are mentioned.

As a quaternary ammonium salt as a hardening accelerator in this invention, For example, tetraalkyl (C1-C18 each alkyl group) ammonium salt [e.g., tetraethylammonium bromide, tetrabutylammonium bromide, tetraalkylammonium carboxylate (carboxylic acid of C1-C12), etc.], aromatic ring containing quaternary ammonium salt [For example, benzyl triphenylammonium carboxylate, etc.] etc. are mentioned.

The adhesive composition of this invention WHEREIN: When the hardening|curing agent and/or hardening accelerator as (D) component are contained, content of (D)component is 0.01 mass % or more with respect to 100 mass % of non-volatile components of an adhesive composition. It is preferable, 0.05 mass % or more is more preferable, 0.1 mass % or more is still more preferable, 0.2 mass % or more is especially preferable. Moreover, 10 mass % or less is preferable, as for content of (D)component, 8 mass % or less is more preferable, 5 mass % or less is still more preferable, 3 mass % or less is especially preferable.

In one embodiment of this invention, content of (D) component in the adhesive composition of this invention is with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 0.1-10 mass %, More preferably, 0.2 to 8% by mass.

<(E) Tackifier>

In the adhesive composition of this invention, for the objective etc. which improve adhesiveness more, you may contain the tackifier (it is also mentioned (E) component hereafter). Tackifiers are also called tackifiers, for example, terpene-based resins, rosin-based resins, alicyclic hydrocarbon resins, aliphatic hydrocarbon resins, aliphatic/aromatic copolymer hydrocarbon resins, aromatic hydrocarbon resins, coumarone-indene resins, etc. can be heard You may use a tackifier in combination of 2 or more type. As a more preferable tackifier, an aliphatic/aromatic copolymer type hydrocarbon resin, aromatic hydrocarbon resin, coumarone indene resin, etc. are mentioned.

(E) When using a component, content of (E) component in the adhesive composition of this invention is although there is no restriction|limiting in particular, From a viewpoint of not impairing the characteristic of the rubber of (A) component, 100 mass of non-volatile components of an adhesive composition With respect to %, 35 mass % or less is preferable, 30 mass % or less is more preferable, and 25 mass % or less is still more preferable. On the other hand, from the viewpoint of improving peel strength, the content thereof is preferably 2% by mass or more, more preferably 4% by mass or more, still more preferably 5% by mass or more, with respect to 100% by mass of the nonvolatile component of the pressure-sensitive adhesive composition. and 6 mass % or more is especially preferable.

In one embodiment of this invention, content of (E) component in the adhesive composition of this invention is with respect to 100 mass % of non-volatile components of an adhesive composition, Preferably it is 5-30 mass %, More preferably, It is 6-25 mass %.

As a commercially available tackifier, for example, Alcon P-90 (manufactured by Arakawa Chemical Industry Co., Ltd.), Alcon P-100 (manufactured by Arakawa Chemical Industry Co., Ltd.), Alcon P-115 (manufactured by Arakawa Chemical Industry Co., Ltd.); Finecrystal ME-G (manufactured by Arakawa Kagakuko Co., Ltd.), Finecrystal ME-H (manufactured by Arakawa Kagakuko Co., Ltd.), Finecrystal ME-G (manufactured by Arakawa Kagakuko Co., Ltd.), T-REZ RB093 (JXTG Energisa) Manufactured by), T-REZ RC115 (manufactured by JXTG Energie), Neopolymer L90 (manufactured by JXTG Energie), Neopolymer 120 (manufactured by JXTG Energizer), Neopolymer 140 (manufactured by JXTG Energizer), T-REZ HA-105 (manufactured by JXTG Energizer), Petrochol 120 (manufactured by Tosoh Corporation), Petrotag 90HS (manufactured by Tosoh Corporation), Petrotag 100V (manufactured by Tosoh Corporation), Novares C9 (manufactured by Novares Lutogas Corporation), Novares L (manufactured by Nitto Chemical Corporation), Nitresin L-5 (manufactured by Nitto Chemical Corporation), Nitresin V-120S (manufactured by Nitto Chemical Corporation), Nitresin G-90 (manufactured by Nitto Chemical Corporation), etc. are mentioned. .

<Other ingredients>

The adhesive composition of this invention may contain other additives different from the said component further. Examples of such additives include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, titanate. inorganic fillers such as magnesium, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate; Calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, barium oxide, calcined dolomite (a mixture containing calcium oxide and magnesium oxide), calcined hydrotalcite (double oxide with aluminum and magnesium, etc.), semi-calcined hydrotalcite, etc. hygroscopic metal oxides; organic fillers such as rubber particles, silicone powder, nylon powder, and fluorine powder; thickeners such as olbene and bentone; silicone-based, fluorine-based, polymer-based defoaming agents or leveling agents; Adhesive imparting agents, such as a triazole compound, a thiazole compound, a triazine compound, and a porphyrin compound, etc. are mentioned. The inorganic filler or the hygroscopic metal oxide may be surface treated with a surface treatment agent to improve its moisture resistance. Examples of the surface treatment agent include an aminosilane-based coupling agent, an epoxysilane-based coupling agent, a mercaptosilane-based coupling agent, a vinylsilane-based coupling agent, an imidazolesilane-based coupling agent, an organosilazane compound, and a titanate-based coupling agent. have. You may use these 1 type or in combination of 2 or more types.

This invention relates to the adhesive composition before (A) component forms a crosslinked structure. That is, the present invention provides (A') an isobutylene-based polymer (one or two or more) having a functional group capable of forming a crosslinked structure, and (A'') having a functional group capable of forming the crosslinked structure An isobutylene-based polymer (one or two or more) and/or a cross-linking agent (one or two or more) having a functional group capable of reacting with the functional group of the isobutylene-based polymer to form a crosslinked structure, (B) a plasticizer and (C) It relates to the adhesive composition containing liquid polyolefin and/or liquid rubber. (A) As a preferable aspect in the adhesive composition before a component forms a crosslinked structure,

(A-1) an isobutylene-based polymer having an epoxy group;

(A-2) an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group;

(B) a plasticizer and

(C) An adhesive composition containing liquid polyolefin and/or liquid rubber is mentioned.

The pressure-sensitive adhesive composition in the present invention may contain an organic solvent. In particular, when the pressure-sensitive adhesive composition before the component (A) forms a cross-linked structure is made into a varnish form for preparing an adhesive sheet having a pressure-sensitive adhesive composition layer formed on a support to be described later, from the viewpoint of coatability of the pressure-sensitive adhesive composition, organic A solvent can be blended. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (hereinafter also abbreviated as "MEK"), cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol. Acetate esters, such as acetate, carbitols, such as cellosolve and butylcarbitol, aromatic hydrocarbons, such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. are mentioned. These organic solvents may use only 1 type, and may use 2 or more types together. Although the quantity of organic solvent is not specifically limited, It is preferable to use the quantity from which the viscosity (25 degreeC) of an adhesive composition will be 300-2,000 mPa*s from a viewpoint of coatability. The adhesive composition of this invention can be manufactured by mixing each component using a kneading roller, a rotary mixer, etc.

The adhesive sheet in this invention can be manufactured through the process of apply|coating and heat-drying a varnish-like adhesive composition on a support body, and forming the adhesive composition layer in which the crosslinked structure was formed. As a preferable aspect of the manufacturing method of the adhesive sheet in this invention, it has the said (A') isobutylene-type polymer which has a functional group which can form a crosslinked structure, (A'') has a functional group which can form the said crosslinked structure An isobutylene-based polymer having a functional group capable of reacting with the functional group of the isobutylene-based polymer to form a crosslinked structure and/or a crosslinking agent, (B) a plasticizer, and (C) liquid polyolefin and/or liquid rubber. In the present invention, the varnish-like pressure-sensitive adhesive composition is applied on a support and dried by heating to form a pressure-sensitive adhesive composition layer having a crosslinked structure. As a more preferable aspect, the adhesive composition before (A) component which contains the said (A-1) component, (A-2) component, (B) component, and (C) component forms a crosslinked structure WHEREIN: A varnish Adhesive composition in which the crosslinked structure is formed by the reaction of the epoxy group of (A-1) component, and the carboxylic acid group and/or carboxylic acid anhydride group of (A-2) component by apply|coating and heat-drying the said adhesive composition of a merchant on a support body forming a layer.

As described above, by applying the varnish-like pressure-sensitive adhesive composition on the support and drying the obtained coating film by heating or hot air spraying, a pressure-sensitive adhesive sheet, which is a sheet in which the adhesive composition layer having a crosslinked structure is formed on the support, is obtained. The thickness of the pressure-sensitive adhesive composition layer in the pressure-sensitive adhesive sheet is preferably 5 µm to 200 µm, more preferably 15 µm to 180 µm, still more preferably 20 µm to 150 µm from the viewpoint of balance between light absorption performance and transmittance. to be.

Although it does not specifically limit as a support body used for an adhesive sheet, Polyolefins, such as polyethylene, polypropylene, and polyvinyl chloride, Polyester, such as polyethylene terephthalate (it may be abbreviated hereafter as "PET"), polyethylenenaphthalate, and poly and plastic films such as carbonate and polyimide. As a plastic film, PET is especially preferable. Moreover, metal foil, such as an aluminum foil, stainless steel foil, and copper foil, may be sufficient as a support body.

When providing a moisture-proof layer to a device, as a support body used for an adhesive sheet, the support body which has moisture-proof property (moisture-proof support body) can be used. Moreover, when providing the layer of a circularly-polarizing plate to a device, a circularly-polarizing plate can be used as a support body used for an adhesive sheet. In addition, when providing a device with the layer of a moisture-proof layer and a circularly-polarizing plate, as a support body used for an adhesive sheet, the support body containing both a moisture-proof support body and a circularly-polarizing plate can be used.

As a support body which has moisture-proof property, metal foils, such as a plastic film which has moisture-proof property, copper foil, aluminum foil, etc. are mentioned. Examples of the plastic film (barrier film) having moisture-proof properties include a plastic film in which an inorganic substance such as silicon oxide (silica), silicon nitride, SiCN, or amorphous silicon is deposited on the surface thereof. Here, as a plastic film on which an inorganic substance is deposited on the surface, for example, polyolefin (for example, polyethylene, polypropylene, polyvinyl chloride, etc.), polyester (for example, polyethylene terephthalate (hereinafter referred to as "PET") Plastic films, such as polyethylene naphthalate), polycarbonate, and polyimide, are suitable, and PET film is especially preferable. Examples of commercially available plastic films having moisture-proof properties include Techbarrier HX, AX, LX, L series (manufactured by Mitsubishi Chemical), and X-BARRIER ( Mitsubishi Chemical Corporation make) etc. are mentioned. In addition, as a support having moisture-proof property, a support having a multilayer structure of two or more layers, for example, one in which the plastic film and the metal foil are bonded through an adhesive may be used. This is inexpensive and is advantageous also in terms of handling properties. Moreover, the support body which does not have moisture-proof property (for example, a single-piece|unit of a plastic film in which the inorganic substance is not vapor-deposited on the said surface) can also be used for the support body of an adhesive sheet.

A circularly polarizing plate is generally comprised by a polarizing plate and a quarter wave plate. When a circularly polarizing plate is used as a support, a quarter wave plate is generally disposed on the pressure-sensitive adhesive composition layer side. In addition, when using a support including both a circularly polarizing plate and a moisture-proof support, preferably, the moisture-proof support is disposed on the pressure-sensitive adhesive composition layer side, and a quarter wave plate of the circularly-polarizing plate is disposed on the moisture-proof support side. The moisture-proof support and the circularly polarizing plate may be adhered using an adhesive or the like.

A support body may perform a mold release process other than a mat process and corona treatment. That is, a peelable support body may be sufficient as a support body. As a mold release process, the mold release process by mold release agents, such as a silicone resin mold release agent, an alkyd resin mold release agent, and a fluororesin mold release agent, is mentioned, for example. In the present invention, when the support has a release layer, the release layer is also regarded as a part of the support. Although the thickness of a support body is not specifically limited, From a viewpoint, such as handleability, Preferably it is 20-200 micrometers, More preferably, it is 20-125 micrometers.

The adhesive sheet WHEREIN: The adhesive composition layer may be protected by the protective film. By protecting with a protective film, adhesion of dust, etc. to the surface of an adhesive composition layer, or a flaw can be prevented. It is preferable to use the same plastic film as a support body for a protective film. Moreover, you may give a mold release process other than a mat process and corona treatment also for a protective film. Although the thickness in particular of a protective film is not restrict|limited, Usually 1-150 micrometers, Preferably it is 10-100 micrometers.

<Electronic device>

The flexible electronic device of this invention can be manufactured by laminating|stacking the adhesive sheet of this invention on the electronic element on a board|substrate, for example, when the adhesive sheet of this invention is a sheet|seat for sealing. Moreover, in the manufacturing process of a flexible electronic device, when laminating|stacking a some material, the adhesive sheet of this invention can be used as an interlayer adhesive agent. For example, if it is a flexible display, a touch panel sensor, a polarizing plate, a surface protection sheet, etc. can be laminated|stacked using the adhesive sheet of this invention as an interlayer adhesive agent.

Example

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited by the following examples, and may be implemented with appropriate changes within the range that can be suitable for the above and below gist. Of course, it is possible, and all of these are included in the technical scope of the present invention. In addition, "part" and "%" in the amount of a component and a copolymerization unit mean "part by mass" and "mass %", respectively, unless otherwise indicated.

Materials used in Examples and Comparative Examples are shown below.

(A-1) component

"ER850" glycidyl methacrylate modified butyl rubber (GMA modified butyl) (manufactured by Seiko PMC), epoxy group concentration 0.64 mmol/g, number average molecular weight 110,000

(A-2) component

"ER641" maleic anhydride modified butyl rubber (MA modified butyl) (manufactured by Seiko PMC), acid anhydride group concentration 0.46 mmol/g, number average molecular weight 57,000

(B) component

"DOP" phthalic acid plasticizer (dioctyl phthalate) (manufactured by J Plus), liquid at 25°C, viscosity at 25°C of 73 mPa·s

"DIDA" adipic acid plasticizer (diisodecyl adipate) (manufactured by J Plus) Liquid at 25°C, viscosity at 25°C 35 mPa·s

"LX-004" liquid polyα-olefin (ethylene-α-olefin cooling oligomer) (manufactured by Mitsui Chemicals) Liquid at 25°C, viscosity at 25°C 727 mPa·s

"LV-50" polybutene (manufactured by JX Energizer) Liquid at 25°C, viscosity at 25°C 223 mPa·s

(B) The viscosity of the component was measured with a vibration-type viscometer (trade name: VISCOMATE MODEL VM-10A) manufactured by Seconic.

(C) component

"Oppanol B10" polyisobutylene (manufactured by BASF), weight average molecular weight 40,000, liquid at 25°C, viscosity at 25°C 21,000 Pa·s

"LIR-290" hydrogenated polyisoprene (manufactured by Kuraray), weight average molecular weight 31,000, liquid at 25°C, viscosity at 25°C 1,400 Pa·s

(C) The viscosity of the component was calculated by dividing the kinematic viscosity at 25°C measured with a rheometer (trade name: DISCOVERY HR-2) manufactured by TA Instruments by the density of each (C) component.

(D) component

"SA102" DBU hardening accelerator (manufactured by San Afro)

other ingredients

"Butyl 065" butyl rubber (manufactured by JSR Corporation)

Each composition of an Example and a comparative example was prepared in the procedure shown below. Compounding was performed in the amount shown in Table 1. In addition, the quantity of components other than the organic solvent of Table 1 is the value converted into the nonvolatile component.

<Example 1>

125 parts of glycidyl methacrylate (GMA) modified butyl rubber (ER850, 20% ifsol solution) (25 parts in terms of non-volatile content) to maleic anhydride (MA) modified butyl rubber (ER641, 35% ifsol solution) 114 parts (40 parts in terms of non-volatile content), 30 parts of phthalic acid ester (DOP), 50 parts of polyisobutylene (Oppanol B10, 50% ifsol solution) (25 parts in terms of non-volatile content) and DBU-based curing accelerator (SA102, 20%) Toluene solution) 5 parts (1 part of non-volatile matter conversion) were mix|blended, the obtained mixture was disperse|distributed uniformly with a high-speed rotation mixer, and the varnish of the adhesive composition was obtained. The obtained varnish was uniformly applied with a die coater on the release-treated surface of a PET film (thickness 38 µm) treated with a silicone-based release agent, and heated at 130° C. for 30 minutes to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive composition layer having a thickness of 25 µm.

<Example 2>

A varnish and a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive composition were prepared in the same manner as in Example 1 except that adipic acid ester (DIDA) was used instead of phthalic acid ester (DOP).

<Example 3>

A varnish and a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive composition were prepared in the same manner as in Example 1 except that an ethylene-α olefin cooligomer (LX-004) was used instead of the phthalic acid ester (DOP).

<Example 4>

A varnish and a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive composition were prepared in the same manner as in Example 1 except that polybutene (LV-50) was used instead of phthalic acid ester (DOP).

<Example 5>

In the same manner as in Example 1, except that polyisoprene (LIR-290) was used instead of polyisobutylene (Oppanol B10), a varnish and a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive composition were prepared.

<Comparative Example 1>

Except not using polyisobutylene (Oppanol B10), it carried out similarly to Example 1, and produced the varnish and the adhesive sheet of the adhesive composition.

<Comparative Example 2>

Except not using phthalic acid ester (DOP), it carried out similarly to Example 1, and produced the varnish and the adhesive sheet of the adhesive composition.

<Comparative Example 3>

Except not using phthalic acid ester (DOP) and polyisobutylene (Oppanol B10), it carried out similarly to Example 1, and produced the varnish and the adhesive sheet of the adhesive composition.

<Comparative Example 4>

To 433 parts of butyl rubber (butyl 065, 15% ifsol solution) (65 parts in terms of non-volatile content), 30 parts of phthalic acid ester (DOP), 50 parts (non-volatile matter) of polyisobutylene (Oppanol B10, 50% ifsol solution) Conversion 25 parts) was mix|blended, and the obtained mixture was disperse|distributed uniformly with a high-speed rotation mixer, and the varnish of the adhesive composition was obtained. The obtained varnish was uniformly applied with a die coater on the release-treated surface of a PET film (thickness 38 µm) treated with a silicone-based release agent, and heated at 130° C. for 30 minutes to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive composition layer having a thickness of 25 µm.

Whether or not a crosslinked structure was formed in the pressure-sensitive adhesive sheets of Examples and Comparative Examples obtained as described above was confirmed as follows.

About 1 g of the adhesive sheet was extract|collected, and this was precisely weighed. Then, the precisely weighed adhesive sheet was immersed in toluene 40g for 7 days, after that, all the toluene-insoluble content of an adhesive composition was collect|recovered, this was dried at 130 degreeC for 2 hours, and the dry mass was calculated|required.

And the gel fraction of the adhesive component was calculated|required by the following formula.

Gel fraction of adhesive sheet = (dry mass of toluene-insoluble content/mass of adhesive sheet before immersion) x 100

If the gel fraction obtained by the above test was 10% or more, it was assumed that a cross-linked structure was formed, and it was confirmed that a cross-linked structure was formed in Comparative Examples except Examples and Comparative Example 4.

The adhesive composition layer of the adhesive sheet of the Example and comparative example obtained by making it above was evaluated as follows.

<Evaluation of responsiveness and recovery to deformation>

The following test evaluated the responsiveness and recoverability with respect to the deformation|transformation which arises when stress is applied to the adhesive composition layer.

A sample for evaluation with a diameter of 8 mm and a thickness of about 1.0 mm is placed on a DHR parallel plate rheometer, a shear stress of 95 kPa is applied for 5 seconds, the applied stress is released at that point, and the sample for evaluation is recovered with a fixture for 60 seconds By doing this, the strain responsiveness test and the strain recovery test were performed on the sample for evaluation.

The strain response was evaluated by the peak shear strain when the 95 kPa shear stress was applied for 5 seconds. In addition, a shear stress of 95 kPa was applied for 5 seconds, the applied stress was released at that time, and the strain recovery property was evaluated by the strain recovery rate after 60 seconds.

The strain recovery is ((S1 - S2)/S1) × 100 (where S1 is the shear strain recorded as a peak 5 seconds after the stress load, and S2 is the shear measured 60 seconds after the stress load is released) It was evaluated by the strain recovery rate obtained by the strain).

<Responsiveness to deformation>

Very good○: Strain is 200 [%] or more

Good △: strain is 100 [%] or more, less than 200 [%]

Defect ×: Less than 100 [%] strain

<Deformation recovery>

Very good○: The strain recovery rate is 50 [%] or more

Good △: the strain recovery rate is 30 [%] or more, less than 50 [%]

Defect ×: The strain recovery rate is less than 30 [%]

<Adhesiveness evaluation>

The adhesiveness of the adhesive composition layer was evaluated by the following test.

The pressure-sensitive adhesive sheet (thickness of the pressure-sensitive adhesive composition layer: 25 µm) produced in Examples and Comparative Examples was cut into a length of 70 mm × width of 20 mm, and the cut pressure-sensitive adhesive sheet was subjected to a batch type vacuum laminator (manufactured by Nichigo Morton, V- 160), an aluminum foil/PET composite film [PET Tsuki AL1N30] having a length of 150 mm and a width of 25 mm (aluminum foil 30 µm, PET 25 µm: Toyo Aluminum Hanbai Co., Ltd. product (name)) was laminated on the aluminum side. Lamination conditions were pressurization for 30 seconds with the pressure of 0.3 MPa after 30 second of temperature 80 degreeC and pressure reduction time. Thereafter, the PET film of the pressure-sensitive adhesive sheet is peeled off, and a glass plate (length 76 mm × width 26 mm × thickness 1.2 mm, microslide glass) is further laminated under the same conditions as above on the exposed pressure-sensitive adhesive composition layer to produce a laminate did About the obtained laminated body, the peeling strength with respect to the glass plate surface when peeled at 90 degree direction with respect to the longitudinal direction of an aluminum foil / PET composite film at 50 mm/min at a tensile rate was measured, and adhesiveness as the following reference|standard was evaluated.

Very good ○: Peel strength of 0.25 [kgf/cm] or more

Good △: peel strength of 0.15 [kgf/cm] or more and less than 0.25 [kgf/cm]

Poor ×: Peel strength less than 0.15 [kgf/cm]

The adhesive sheet of the present invention has high adhesiveness, and is excellent in responsiveness and recovery to deformation, and can be excellent as a sealing sheet for flexible electronic devices, an adhesive sheet, a transparent optical adhesive sheet (OCA), or the like.

This application is based on Japanese Patent Application No. 2019-180696 filed in Japan, the contents of which are all included in this specification.

Claims (16)

A pressure-sensitive adhesive sheet comprising a support and a pressure-sensitive adhesive composition layer formed on the support, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition layer,
(A) an isobutylene-based polymer having a crosslinked structure;
(B) a plasticizer and
(C) A pressure-sensitive adhesive sheet containing liquid polyolefin and/or liquid rubber. The adhesive sheet according to claim 1, wherein the plasticizer is a plasticizer that is liquid at 25°C and has a viscosity at 25°C of less than 10,000 mPa·s. The adhesive sheet according to claim 1 or 2, wherein the liquid polyolefin and/or liquid rubber is liquid at 25°C and has a viscosity at 25°C of 10,000 mPa·s or more. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the isobutylene-based polymer having a crosslinked structure includes a crosslink formed by reacting an epoxy group, a carboxylic acid group, and/or a carboxylic acid anhydride group. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the isobutylene-based polymer is a copolymer of isobutylene and isoprene. The isobutylene-based polymer having a crosslinked structure according to any one of claims 1 to 5, wherein the isobutylene-based polymer having an epoxy group is a reaction product of an isobutylene-based polymer having an epoxy group and an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group , adhesive sheet. The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive composition contains 40 to 80% by mass of the isobutylene-based polymer having a crosslinked structure with respect to 100% by mass of the nonvolatile component of the pressure-sensitive adhesive composition. The adhesive sheet in any one of Claims 1-7 in which an adhesive composition contains 10-45 mass % of plasticizers with respect to 100 mass % of non-volatile components of an adhesive composition. The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive composition contains a liquid polyolefin and/or a liquid rubber in an amount of 10 to 45 mass% with respect to 100 mass% of the nonvolatile component of the pressure-sensitive adhesive composition. The adhesive sheet according to any one of claims 1 to 9, which is for a flexible electronic device. The adhesive sheet according to claim 10, wherein the flexible electronic device is a flexible organic EL device or a flexible solar cell device. (A) an isobutylene-based polymer having a crosslinked structure;
(B) a plasticizer and
(C) A pressure-sensitive adhesive composition containing liquid polyolefin and/or liquid rubber. (A') an isobutylene-based polymer having a functional group capable of forming a crosslinked structure;
(A'') an isobutylene-based polymer and/or a crosslinking agent having a functional group capable of forming a crosslinked structure by reacting with the functional group of the isobutylene-based polymer having a functional group capable of forming the crosslinked structure;
(B) a plasticizer and
(C) A pressure-sensitive adhesive composition comprising liquid polyolefin and/or liquid rubber. (A-1) an isobutylene-based polymer having an epoxy group;
(A-2) an isobutylene-based polymer having a carboxylic acid group and/or a carboxylic acid anhydride group;
(B) a plasticizer and
(C) A pressure-sensitive adhesive composition comprising liquid polyolefin and/or liquid rubber. A method for producing a pressure-sensitive adhesive sheet, comprising the step of applying the pressure-sensitive adhesive composition according to claim 13 or 14 in the form of varnish on a support and drying it by heating to form a layer of the pressure-sensitive adhesive composition having a crosslinked structure. The varnish-like pressure-sensitive adhesive composition according to claim 14 is applied on a support and dried by heating, (A-1) an epoxy group of an isobutylene-based polymer having an epoxy group, and (A-2) an iso having a carboxylic acid group and/or a carboxylic acid anhydride group A method for producing a pressure-sensitive adhesive sheet, comprising the step of forming a pressure-sensitive adhesive composition layer having a crosslinked structure formed thereon by reaction with a carboxylic acid group and/or a carboxylic acid anhydride group of a butylene-based polymer.