JP2011144260A - Adhesive and adhesive tape - Google Patents

Abstract

A light-colored, flexible, heat-resistant adhesive containing a polyimide resin composition and an adhesive tape using the same are provided.
A polyimide in which polyoxyalkylene diamine is 50 mol% or more of total diamine as a diamine component or an organic solvent solution of the polyimide, and maleimide in a ratio of 0.05 mol to 10 mol with respect to 1 mol of the polyimide. A pressure-sensitive adhesive obtained by irradiating a polyimide resin composition containing a compound with ultraviolet rays, and a pressure-sensitive adhesive tape using the pressure-sensitive adhesive.
[Selection figure] None

Description

  The present invention relates to a pressure-sensitive adhesive obtained by irradiating a polyimide resin composition whose cured product has adhesiveness with ultraviolet rays, and a pressure-sensitive adhesive tape formed on the thin-film substrate.

  Conventionally, fluorine-based adhesives and silicone-based adhesives are well known as heat-resistant adhesives of 200 ° C. or higher. Fluorine-based pressure-sensitive adhesives have the highest heat resistance but have the problem of being very expensive. Silicone pressure-sensitive adhesives are inexpensive and have excellent heat resistance, so they are used in a wide range of fields. However, when exposed to a high temperature of about 250 ° C for a long time, siloxane gas is generated, resulting in poor insulation. Has a causative problem. Conventionally used silicone pressure-sensitive adhesives include a peroxide curing type and an addition reaction curing type. Peroxide-curing silicone-based adhesives use organic peroxides such as benzoyl peroxide as the curing agent, and a high temperature of 150 ° C or higher is required to cure them. There is a problem that coating is difficult. There is a demand for a heat-resistant pressure-sensitive adhesive that is lower in cost than a fluorine-based pressure-sensitive adhesive and that does not deteriorate even at a high temperature of 250 ° C., but a satisfactory one has not been obtained.

  Conventionally, polyimide resins have been widely used as engineering plastics with excellent heat resistance. Above all, bismaleimide compounds and aromatic diamines are used as raw materials, and polyimide resins obtained by reacting them are thermosetting polyimide resins as electrical insulating materials. Widely used. It is known that a cured product of thermosetting polyimide resin using polyoxyalkylene bismaleimide, aromatic bismaleimide, and aromatic diamine, which are aliphatic bismaleimides, has not only heat resistance but also adhesiveness ( For example, see Patent Document 2). However, in order to obtain a cured product by reacting the above bismaleimide compound and aromatic diamine, a high temperature of 150 ° C. or more and a long time are required. It is difficult to apply to. Moreover, although there is also a report of a polyimide-based pressure-sensitive adhesive as a pressure-sensitive adhesive having a heat resistance of 250 ° C. or higher (see Patent Document 3), a temperature of 200 ° C. or higher, or a high temperature of 150 ° C. or higher and a long time are required for curing. Therefore, a large amount of energy is required during production, and coating on a substrate having a low heat-resistant temperature is difficult. This cured product is highly colored and cannot be applied to fields requiring light-colored transparency, which has been demanded in recent years.

Japanese Patent Publication No.54-37907 U.S. Pat. No. 4,116,937 WO2008 / 041723

  The present invention has been made in view of the above circumstances, and is a light-colored and flexible adhesive obtained by irradiating ultraviolet rays, and an adhesive that generates little decomposition gas even when heated to 250 ° C. It is an object of the present invention to provide a pressure-sensitive adhesive tape formed on a transparent thin film substrate.

  The inventors diligently studied to solve the above problems. As a result, the main chain is composed of a repeating unit having a polyoxyalkylene diamine structure, and a polyimide (A) obtained by blending a diamine component at a ratio of 1.01 mol to 2 mol with respect to 1 mol of a tetracarboxylic acid component. Or the hardening | curing obtained by irradiating the polyimide resin composition which contains the organic solvent solution of a polyimide (A), and a maleimide compound in the ratio of 0.05 mol or more and 10 mol or less with respect to 1 mol of polyimide (A). It has been found that the product is light in color, flexible, and has not only heat resistance such as less generation of decomposition gas even when heated to 250 ° C., but also has adhesiveness. Furthermore, it was formed on a thin film substrate having transparency, and the present invention was completed.

（式（１）中、Ｒ_１は４価の有機基である）

（式（２）中、Ｒ_１は４価の有機基であり、Ｙ_１〜Ｙ_４は各々独立して水素原子又は炭素数１〜８の炭化水素基である。）

（式（３）中、Ｘ_１、Ｘ_２は、各々Ｃ_１〜Ｃ_４のアルキレン基、ｋ、ｍは各々ＯＸ_１単位の繰り返し数、ｌはＯＸ_２単位の繰り返し数であり、ｋ＋ｍは数平均重合度を示し１〜９０の範囲内の数（ｍは０ではない）であり、ｌは数平均重合度を示し０〜８０の範囲内の数である。）

（式（４）中、Ｒ₂は、脂肪族基、脂環基又は芳香族基からなる炭素数１〜２２１の２価の有機基であり、その構造の一部にエーテル基、メチレン基、その他の置換基を含んでいてもよい。）
２． 式（１）および式（２）の各々におけるＲ_１が、シクロヘキサンから誘導される４価の基及びベンゼンから誘導される４価の基から選ばれる１種以上であることを特徴とする、第１項に記載の粘着剤。
３． 式（１）および式（２）の各々におけるＲ_１がシクロヘキサンから誘導される４価の基であることを特徴とする、第１項に記載の粘着剤。
４． 前記ポリオキシアルキレンジアミンが、式（５）で表されるプロピレンオキシドとエチレンオキシドに由来する骨格からなるポリオキシアルキレンジアミンを含むことを特徴とする、第１項〜第３項のいずれかに記載の粘着剤。

（式（５）中、ａ、ｃは各々プロピレンオキシド単位の繰り返し数を示し、ｂはエチレンオキシド単位の繰り返し数を示す。）
５． 前記ポリオキシアルキレンジアミンが、式（６）で表されるプロピレンオキシド骨格からなるポリオキシアルキレンジアミンを含むことを特徴とする、第１項〜第３項のいずれかに記載の粘着剤。

（式（６）中、ｄはプロピレンオキシド単位の繰り返し数を示す。）
６． 前記ポリオキシアルキレンジアミンが、式（７）で表されるプロピレンオキシドとブチレンオキシドに由来する骨格からなるポリオキシアルキレンジアミンを含むことを特徴とする、第１項〜第３項のいずれかに記載の粘着剤。

（式（７）中、ｅ、ｇは各々プロピレンオキシド単位の繰り返し数を示し、ｆはブチレンオキシド単位の繰り返し数を示す。）
７． 前記ポリイミド（Ａ）が、式（１）で表されるテトラカルボン酸二無水物ならびに式（２）で表されるテトラカルボン酸およびテトラカルボン酸の誘導体から選ばれた１種以上の化合物からなるテトラカルボン酸成分と、式（３）で表されるポリオキシアルキレンジアミンが総ジアミン中５０モル％以上である式（４）で表されるジアミン成分を、テトラカルボン酸成分１モルに対してジアミン成分を１．０１モル以上２モル以下の割合で配合し、１６０〜２５０℃の温度で０．５〜２４時間加熱反応させて得られるものである、第１項〜第６項のいずれかに記載の粘着剤。
８． 前記ポリイミド（Ａ）の有機溶剤溶液における総溶剤中の５０重量％以上が１，３−ジオキソランである、第７項に記載の粘着剤。
９． 前記ポリイミド樹脂組成物を、０〜１５０℃の環境に０．０１〜３時間存在させた後、紫外線積算光量１〜１００００ｍＪ／ｃｍ^２の条件で光照射して得られる第１項〜第８項のいずれかに記載の粘着剤。
１０． 第９項に記載の粘着剤を、耐熱性薄膜基材上に形成した粘着テープ。
１１． 前記耐熱性薄膜基材が、透明性を有する第１０項に記載の粘着テープ。
１２． 第１１項に記載の透明性を有する耐熱性薄膜基材の構造が、式（８）で表されるポリイミドである粘着テープ。

（式（８）中、Xは炭素数が２〜３９の２価の脂肪族基、炭素数が３〜３９の２価の脂環族基、炭素数が６〜３９の２価の芳香族基又はこれらの組み合わせからなる２価の基であり、Ｘの主鎖には、−Ｏ−、−ＳＯ_２−、−ＣＨ_２−、−Ｃ（ＣＨ_３）_２−、−ＯＳｉ（ＣＨ_３）_２−、−Ｃ_２Ｈ_４Ｏ−及び−Ｓ−からなる群から選ばれた少なくとも１種の結合基が介在していてもよく、Ｘはカルボキシル基、水酸基及びカルボニル基からなる群から選ばれた少なくとも１種の官能基を有していてもよい）
１３． 第９項に記載の粘着剤を、剥離フィルム上に形成した粘着フィルム。 That is, the present invention is as follows.
1. A tetracarboxylic acid component comprising one or more compounds selected from the tetracarboxylic dianhydride represented by the formula (1) and the tetracarboxylic acid represented by the formula (2) and a tetracarboxylic acid derivative; The diamine component represented by the formula (4) in which the polyoxyalkylene diamine represented by (3) is 50 mol% or more in the total diamine is 1.01 mol or more of the diamine component per 1 mol of the tetracarboxylic acid component The polyimide (A) or polyimide (A) organic solvent solution blended at a ratio of 2 mol or less and the maleimide compound are contained at a ratio of 0.05 mol or more and 10 mol or less with respect to 1 mol of the polyimide (A). A pressure-sensitive adhesive obtained by irradiating a polyimide resin composition with ultraviolet rays.

(In formula (1), R ₁ is a tetravalent organic group)

(In Formula (2), R ₁ is a tetravalent organic group, and Y _{1 to} Y ₄ are each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.)

(In Formula (3), X ₁ and X ₂ are each a C _{1 to} C ₄ alkylene group, k and m are each a repeating number of OX ₁ units, l is a repeating number of OX ₂ units, and k + m is a number. The average degree of polymerization is a number within the range of 1 to 90 (m is not 0), and l is the number average degree of polymerization and a number within the range of 0 to 80.)

(In the formula (4), R ₂ is an aliphatic group, a divalent organic group having a carbon number of 1 to 221 consisting of alicyclic group or an aromatic group, an ether group in a part of its structure, a methylene group, Other substituents may be included.)
2. R ₁ in each of the formulas (1) and (2) is one or more selected from a tetravalent group derived from cyclohexane and a tetravalent group derived from benzene, Item 1. The pressure-sensitive adhesive according to item 1.
3. The pressure-sensitive adhesive according to item 1, wherein R ₁ in each of formula (1) and formula (2) is a tetravalent group derived from cyclohexane.
4). The polyoxyalkylene diamine contains a polyoxyalkylene diamine having a skeleton derived from propylene oxide and ethylene oxide represented by the formula (5), according to any one of Items 1 to 3. Adhesive.

(In formula (5), a and c each represent the number of repeating propylene oxide units, and b represents the number of repeating ethylene oxide units.)
5. The pressure-sensitive adhesive according to any one of Items 1 to 3, wherein the polyoxyalkylene diamine includes a polyoxyalkylene diamine having a propylene oxide skeleton represented by Formula (6).

(In formula (6), d represents the number of repeating propylene oxide units.)
6). The polyoxyalkylene diamine contains a polyoxyalkylene diamine having a skeleton derived from propylene oxide and butylene oxide represented by the formula (7), according to any one of Items 1 to 3. Adhesive.

(In formula (7), e and g each represent the number of repeating propylene oxide units, and f represents the number of repeating butylene oxide units.)
7). The polyimide (A) is composed of one or more compounds selected from a tetracarboxylic dianhydride represented by the formula (1) and a tetracarboxylic acid represented by the formula (2) and a tetracarboxylic acid derivative. The tetracarboxylic acid component and the diamine component represented by the formula (4) in which the polyoxyalkylene diamine represented by the formula (3) is 50 mol% or more in the total diamine are converted into Any one of Items 1 to 6, which is obtained by blending the components at a ratio of 1.01 mol to 2 mol and heating and reacting at a temperature of 160 to 250 ° C. for 0.5 to 24 hours. The adhesive as described.
8). The pressure-sensitive adhesive according to item 7, wherein 50% by weight or more of the total solvent in the organic solvent solution of polyimide (A) is 1,3-dioxolane.
9. First to eighth items obtained by allowing the polyimide resin composition to exist in an environment of 0 to 150 ° C. for 0.01 to 3 hours and then irradiating with light under conditions of an ultraviolet light accumulated light amount of 1 to 10,000 mJ / cm ^2. The adhesive in any one of.
10. The adhesive tape which formed the adhesive of Claim 9 on the heat-resistant thin film base material.
11. Item 11. The pressure-sensitive adhesive tape according to item 10, wherein the heat-resistant thin film substrate has transparency.
12 A pressure-sensitive adhesive tape, wherein the structure of the heat-resistant thin film substrate having transparency according to Item 11 is polyimide represented by the formula (8).

(In the formula (8), X is a divalent aliphatic group having 2 to 39 carbon atoms, a divalent alicyclic group having 3 to 39 carbon atoms, and a divalent aromatic group having 6 to 39 carbon atoms. A divalent group consisting of a group or a combination thereof, and the main chain of X includes —O—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ). _At least one linking group selected from the group consisting of _2- , -C ₂ H ₄ O- and -S- may be interposed, and X is selected from the group consisting of a carboxyl group, a hydroxyl group and a carbonyl group. And may have at least one functional group)
13. The adhesive film which formed the adhesive of Claim 9 on the peeling film.

  The pressure-sensitive adhesive of the present invention comprises a repeating unit having a main chain having a polyoxyalkylenediamine structure, and is formed by blending a diamine component at a ratio of 1.01 mol to 2 mol with respect to 1 mol of a tetracarboxylic acid component. An organic solvent solution of polyimide (A) or polyimide (A) and a polyimide resin composition containing a maleimide compound in a proportion of 0.05 mol or more and 10 mol or less with respect to 1 mol of polyimide (A) are applied to a substrate. After drying, it is obtained by curing with light in the UV region. Curing with light in the UV region can be expected to ease the reaction conditions for obtaining a pressure-sensitive adhesive as compared with thermal curing at 200 ° C. or higher, and rationalize the work process by reducing energy consumption. In addition, since the adhesive is light in color and has heat resistance such as generation of decomposition gas even when heated to 250 ° C., it is expected to be applied to adhesives that require both light-colored transparency and heat resistance. Is done. Moreover, the adhesive tape which formed it on the heat resistant thin film base material which has transparency can be used as an adhesive tape which needs light color transparency and heat resistance.

Hereinafter, the present invention will be described in detail.
The pressure-sensitive adhesive of the present invention is preferably obtained by a method including the following steps I to IV.
Process I
An organic solvent solution of polyimide (A) or polyimide (A) is produced.
Process II
A polyimide resin composition is produced by mixing polyimide (A) or an organic solvent solution of polyimide (A) with a maleimide compound, and if necessary, an organic solvent or other additives.
Process III
The polyimide resin composition is cured to produce an adhesive.

  Step I will be described. Polyimide (A) is a solution polymerization method, a method of preparing a polyamic acid solution, forming a film and imidizing it, obtaining a salt or imide oligomer such as a half ester salt, and performing solid phase polymerization, and other conventionally known methods It can be manufactured by the method. You may use each method together. The reaction between the tetracarboxylic acid component and the diamine may be carried out in the presence of a conventionally known catalyst such as an acid, a tertiary amine or an anhydride.

Among these methods, since a polyimide (A) or polyimide (A) organic solvent solution is obtained directly, the following solution polymerization methods (1) to (5) are preferred.
(1) A mixture containing a diamine component, an organic solvent as necessary, and a catalyst as necessary is stirred at 10 to 600 rpm to form a homogeneous solution, which is maintained at a temperature of 30 to 90 ° C., and a tetracarboxylic acid component and necessary Depending on the catalyst is added.
(2) A mixture containing a tetracarboxylic acid component, an organic solvent, and, if necessary, a catalyst is stirred at 10 to 600 rpm to obtain a homogeneous solution, which is maintained at a temperature of 30 to 90 ° C., and a diamine component and, if necessary, organic. Add solvent and, if necessary, catalyst.
(3) After the method (1) or (2), the temperature is raised to 160 to 250 ° C, preferably 180 to 205 ° C over 0.1 to 6 hours. While collecting the components to be removed outside the reaction system, the temperature is kept substantially constant for 0.5 to 24 hours, preferably 2 to 12 hours.
(4) After (3), perform this operation as necessary. The temperature is adjusted to a temperature equal to or lower than the temperature kept constant in (3), aromatic diamine is added, and the temperature is adjusted to 160 to 250 ° C, preferably 180 to 205 ° C over 0.1 to 6 hours. While collecting the components to be removed outside the reaction system, the temperature is kept substantially constant for 0.5 to 24 hours, preferably 2 to 12 hours.
(5) Add an organic solvent as necessary, cool to a temperature convenient for handling, and stop stirring.

  Solution polymerization for producing the polyimide (A) includes trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methyl. The reaction may be performed in the presence of at least one catalyst selected from tertiary amine compounds such as pyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, and isoquinoline. When using, the usage-amount of a catalyst has preferable 0.1-100 mol% of the tetracarboxylic acid component, and its 1-10 mol% is more preferable.

  Of the tetracarboxylic dianhydrides of formula (1) used in the present invention, examples of the aliphatic tetracarboxylic dianhydrides include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1, 2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2 2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyltetracarboxylic dianhydride and the like.

  Among the tetracarboxylic dianhydrides of the formula (1) used in the present invention, examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyl. Tetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis ( 2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2 -Bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3 4-Dicarboxyphenyl) ete Dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic Acid dianhydride, 4,4 ′-(p-phenylenedioxy) diphthalic dianhydride, 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride, ethylenetetracarboxylic dianhydride, 3 -Carboxymethyl-1,2,4-cyclopentanetricarboxylic dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride And bis (3,4-dicarboxyphenyl) methane dianhydride.

  Among the tetracarboxylic acids of the formula (2) and their derivatives used in the present invention, examples of the aliphatic tetracarboxylic acids and their derivatives include 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2 , 3,4-Butanetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, bicyclo [2.2.2] oct-7-ene Examples include -2,3,5,6-tetracarboxylic acid, dicyclohexyltetracarboxylic acid, and the like, and esters thereof with alcohols having 1 to 8 carbon atoms.

  Among the tetracarboxylic acids of the formula (2) and their derivatives used in the present invention, examples of the aromatic tetracarboxylic acid and its derivatives include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetra Carboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) -1,1, 1,3,3,3-hexafluoropropane, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, bis (2,3-dicarboxyphenyl) ether 3,3 ′, 4,4′-benzophenone tetracarboxylic acid, 2,2 ′, 3,3′-benzophenone tetracarboxylic acid, 4,4 ′-(p-phenylenedioxy) diphthalic acid, 4,4′- (M-phenylenedioxy) diphthalic acid, ethylenetetracarboxylic acid, 3-carboxymethyl-1,2,4-cyclopentanetricarboxylic acid, 1,1-bis (2,3-dicarboxyphenyl) ethane, bis (2 , 3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane and the like and esters thereof with alcohols having 1 to 8 carbon atoms.

  Of these tetracarboxylic anhydrides, tetracarboxylic acids and derivatives of the tetracarboxylic acids, those having a structure derived from cyclohexane or those having a structure derived from benzene are preferred, and more preferably derived from cyclohexane. Those having a structure are preferable, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride or 1,2,4,5-cyclohexanetetracarboxylic acid is particularly preferable, and these are one kind alone or Two or more types can be mixed and used.

  In general, in the production of polyimide, tetracarboxylic dianhydride is usually used as tetracarboxylic acids, but in the present invention, in addition to tetracarboxylic dianhydride, the tetracarboxylic acid or tetracarboxylic acid and A practical polyimide can be produced using a derivative such as an ester with alcohol. Since tetracarboxylic acid can be used as it is, it is advantageous in terms of production equipment and cost.

R _{2 in} the diamine component of the formula (4) used in the present invention is a divalent organic group having 1 to 221 carbon atoms composed of an aliphatic group, an alicyclic group, or an aromatic group. The part may contain an ether group, a methylene group, and other substituents.

  In the diamine component of the formula (4) used in the present invention, it is preferable that 50 mol% or more of polyoxyalkylene diamine is contained because a thermosetting polyimide resin composition having adhesiveness in addition to flexibility is obtained. The tackiness in the present invention refers to the property of adhering only by applying a slight pressure at room temperature for a short time without using water, solvent, heat, etc. This refers to the force required to peel off the contacted body after it has been brought into contact with a slight pressure. The polyoxyalkylene diamine belongs to an aliphatic diamine which is a diamine in which an aliphatic group or an alicyclic group is directly bonded to an amino group.

  Examples of the polyoxyalkylene diamine include a polyoxypropylene diamine represented by the formula (9), a polyoxyethylene diamine represented by the formula (16), and a polyoxybutylene represented by the formula (17). Examples include diamines or diamines containing 2 or more selected from the group consisting of oxyethylene, oxypropylene and oxybutylene as repeating units, and polyoxyalkylenes having oxypropylene and oxyethylene represented by formula (8) as repeating units. A diamine, or a polyoxyalkylene diamine having a repeating unit of oxypropylene or oxybutylene represented by the formula (10) is preferable for obtaining a cured product having good tackiness.

（式（６）中、ｄはプロピレンオキシド単位の繰り返し数を示す。）

(In formula (6), d represents the number of repeating propylene oxide units.)

（式（９）中、ｎ_２はエチレンオキシド単位の繰り返し数を示す。）

(In the formula (9), n ₂ represents the number of repeating ethylene oxide units.)

（式（１０）中、ｎ_３はブチレンオキシド単位の繰り返し数を示す。）

(In the formula (10), n ₃ represents the number of repeating butylene oxide units.)

（式（５）中、ａ、ｃは各々プロピレンオキシド単位の繰り返し数を示し、ｂはエチレンオキシド単位の繰り返し数を示す。）

(In formula (5), a and c each represent the number of repeating propylene oxide units, and b represents the number of repeating ethylene oxide units.)

（式（７）中、ｅ、ｇは各々プロピレンオキシド単位の繰り返し数を示し、ｆはブチレンオキシド単位の繰り返し数を示す。）

(In formula (7), e and g each represent the number of repeating propylene oxide units, and f represents the number of repeating butylene oxide units.)

  The molecular weight of the polyoxypropylenediamine of formula (6) is preferably 230 to 4000 (oxypropylene repeating unit number d is 2.6 to 68.0), more preferably 600 to 2000 (oxypropylene repeating unit number). d is 8.7-33.0).

The molecular weight of the polyoxyethylene diamine of the formula (9) is preferably 300 to 4000 (the number of repeating units _{n 2} of oxyethylene is from 5.5 to 89.5), more preferably 600 to 2000 (number of repetitive units of oxyethylene n ₂ is 12.3 to 44.1).

Wherein the molecular weight of the polyoxybutylene diamine (10) is preferably 200 to 4000 (the number of repeating units _{n 3} oxybutylene is 1.6 to 54.3), more preferably 600 to 2000 (repeat units of oxybutylene the number _{n 3} is a is 7.1 to 26.6).

  In order to obtain a cured product having good tackiness, the polyoxyalkylene diamine preferably has the following molecular weight. The molecular weight of the polyoxyalkylenediamine of formula (5) is preferably 300 to 4000 (the number of repeating units of oxypropylene (a + c) is 1.0 to 9.4 (c is not 0), the number of repeating units of oxyethylene ( b) is 3.7 to 79.8), more preferably 600 to 2000 (the number of repeating units of oxypropylene (a + c) is 3.6 to 6.0 (c is not 0)), and the repetition of oxyethylene The number of units (b) is 9.0 to 38.7).

  The molecular weight of the polyoxyalkylenediamine of formula (7) is preferably 300 to 4000 (the number of repeating units of oxypropylene (e + g) is 1.0 to 58.0 (g is not 0), the number of repeating units of oxybutylene ( f) is 3.0 to 34.0), more preferably 1000 to 2000 (the number of repeating units of oxypropylene (e + g) is 6.0 to 24.0 (g is not 0), and repeating oxybutylene) The number of units (f) is 9.0 to 17.0).

  Among the diamine components represented by the formula (4) used in the present invention, as aliphatic diamines other than polyoxyalkylene diamine, for example, 4,4′-diaminodicyclohexylmethane, isophoronediamine, ethylenediamine, tetramethylenediamine, Norbornanediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, hexamethylenediamine, metaxylylenediamine, 4,4′-methylenebis (cyclohexylamine), bicyclohexyldiamine, Examples thereof include siloxane diamines. Among them, it is preferable to use a diamine having an alicyclic structure such as 4,4'-diaminodicyclohexylmethane, isophoronediamine, 1,3-diaminocyclohexane, etc., because it is easy to increase the molecular weight and has excellent heat resistance. These diamines can be used alone or in admixture of two or more.

  Among the diamine components represented by the formula (4) used in the present invention, as the aromatic diamine, for example, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, m-phenylenediamine, p-phenylenediamine, 2,4-toluenediamine, diaminobenzophenone, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, 1,4-bis (4 -Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, α, α ' -Bis (3-aminophenyl) -1,4-diisopropylbenzene, bis [4- (4-aminophenoxy) ) Phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene and 2,2-bis (4-aminophenoxyphenyl) ) Propane and the like. Among these, 4,4'-diaminodiphenyl ether is preferred, and these can be used alone or in combination of two or more.

  The polyimide (A) can be produced in the absence of a solvent, but may be produced in the presence of a solvent. Specifically, relatively high boiling point solvents such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, tetramethylene sulfone, methanol, Ethanol, isopropyl alcohol, 1-propyl alcohol, 1-butanol, 2-butanol, tertiary butanol, butanediol, ethylhexanol, benzyl alcohol and other alcohols, tetrahydrofuran, 1,3-dioxolane, dioxane, methyl cellosolve, cellosolve, Solvents having an ether bond such as butyl cellosolve, dioxane, methyl tertiary butyl ether, butyl carbitol, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, Ketones such as clopentanone and cyclohexanone, solvents having ester bonds such as ethyl acetate, methyl acetate, butyl acetate, normal propyl acetate, isopropyl acetate and methyl lactate, toluene, xylene, m-xylene, n-hexane, isohexane, cyclohexane Hydrocarbon solvents such as methylcyclohexane and normal heptane can be used, and one or more may be used at the same time.

  Step II will be described. The polyimide resin composition in the present invention can be obtained by mixing polyimide (A) or an organic solvent solution of polyimide (A) with a maleimide compound, and if necessary, an organic solvent or other additives. As the mixing method, any conventionally known method such as a method using a stirring blade or a dissolver, a method using centrifugal force, and the like can be used. Although the temperature at the time of mixing does not have a restriction | limiting in particular, Room temperature-about 80 degreeC is preferable when the melt | dissolution in a short time and handling property are considered. When the mixing temperature is higher than 80 ° C., curing may be accelerated, which may not be preferable. The atmosphere during mixing can be in the air, but is preferably dry air or under a nitrogen stream.

  Examples of the maleimide compound used in the present invention include the following.

（式（１３）中、ｈは１以上の整数である。）

(In formula (13), h is an integer of 1 or more.)

  The maleimide compound also includes a bismaleimide compound. Examples of the bismaleimide compound include N, N ′-(4,4′-diphenylmethane) bismaleimide, N, N ′-(4,4′-diphenyloxy) bismaleimide, N, N ′-(4,4 ′. -Diphenylsulfone) bismaleimide, N, N'-p-phenylenebismaleimide, N, N'-m-phenylenebismaleimide, 4-methyl-1,3-phenylenebismaleimide, N, N'-2,4- Tolylene bismaleimide, N, N′-2,6-tolylene bismaleimide, N, N′-ethylene bismaleimide, N, N′-hexamethylene bismaleimide, N, N ′-{4,4 ′-[ 2,2′-bis (4 ″, 4 ′ ″-phenoxyphenyl) isopropylidene]} bismaleimide, N, N ′-{4,4 ′-[2,2′-bis (4 ″, 4 '' '-Feno Xylphenyl) hexafluoroisopropylidene]} bismaleimide, N, N ′-[4,4′-bis (3,5-dimethylphenyl) methane] bismaleimide, N, N ′-[4,4′-bis (3 , 5-diethylphenyl) methane] bismaleimide, N, N ′-[4,4 ′-(3-methyl-5-ethylphenyl) methane] bismaleimide, N, N ′-[4,4′-bis ( 3,5-diisopropylphenyl) methane] bismaleimide, N, N ′-(4,4′-dicyclohexylmethane) bismaleimide, N, N′-p-xylylene bismaleimide, N, N′-m-xylylene Bismaleimide, N, N ′-(1,3-dimethylenecyclohexane) bismaleimide, N, N ′-(1,4-dimethylenecyclohexane) bismaleimide and the like.

  Further, as the maleimide compound, a bismaleimide compound in which both ends of the polyoxyalkylene diamine are sealed with maleic anhydride can also be used. For example, a bismaleimide compound in which both ends of polyoxyethylenediamine are sealed with maleic anhydride, a bismaleimide compound in which both ends of polyoxypropylenediamine are sealed with maleic anhydride, and both ends of polyoxybutylenediamine are anhydrous Examples include compounds sealed with maleic acid. Among these maleimide compounds, N, N ′-(4,4′-diphenylmethane) bismaleimide, N, N′-m-phenylenebismaleimide, 4-methyl-1,3-phenylenebismaleimide, (11) Maleimide compounds represented by formula (12) and formula (13). These conventionally known maleimide compounds can be used in combination of one or more.

  The following are mentioned as an organic solvent added to the polyimide resin composition in this invention as needed. Relatively high boiling point solvents such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, tetramethylene sulfone, methanol, ethanol, isopropyl alcohol 1-propyl alcohol, 1-butanol, 2-butanol, tertiary butanol, butanediol, ethylhexanol, benzyl alcohol and other alcohols, tetrahydrofuran, 1,3-dioxolane, dioxane, methyl cellosolve, cellosolve, butyl cellosolve, dioxane, Solvents with an ether bond such as methyl tertiary butyl ether and butyl carbitol, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopent Non-, cyclohexanone and other ketones, ethyl acetate, methyl acetate, butyl acetate, normal propyl acetate, isopropyl acetate, methyl lactate and other solvents having an ester bond, toluene, xylene, m-xylene, n-hexane, isohexane, cyclohexane Hydrocarbon solvents such as methylcyclohexane and normal heptane can be used, and one or more may be used at the same time.

  In the polyimide resin composition in the present invention, a polymerization initiator is not particularly required. However, a polymerization initiator may be added at all in the case of containing a reactive diluent or in the sense of promoting maleimide curing. The polymerization initiator in the present invention means a radical polymerization initiator, and requires a photopolymerization initiator having an action of generating radicals by irradiating active energy rays such as ultraviolet rays to start polymerization, or irradiation with active energy rays. The organic peroxide has a function of generating a radical with thermal energy and initiating polymerization over a wide temperature range from low temperature to medium temperature and high temperature.

  Conventionally known photopolymerization initiators as radical polymerization initiators can be used. Preferred photopolymerization initiators include, for example, benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin isopropyl ether, and benzoin. Alkyl ethers, acetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino- Acetophenones such as propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, N, N-dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone , 2- Anthraquinones such as minoanthraquinone, thioxanthones such as 2,4-dimethylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bis And benzophenones such as diethylaminobenzophenone and xanthones. One or more of these may be used in combination. These photopolymerization initiators may be used in combination with a photosensitizer. For example, conventionally known photosensitizers such as benzoic acid esters such as ethyl-4-dimethylaminobenzoate and 2- (dimethylamino) ethylbenzoate, or tertiary amines such as triethylamine and triethanolamine, One or more of these may be used in combination.

  On the other hand, as the above-mentioned organic peroxide as the radical polymerization initiator, conventionally known ones can be used, for example, ketone peroxides such as methyl ethyl ketone peroxide and acetoacetate peroxide, cumene hydroperoxide, etc. Hydroperoxides, peroxycarbonates such as bis- (4-t-butylcyclohexyl) peroxycarbonate, 1,1-di-t-butylperoxy 3,3,5 trimethylcyclohexanone, 1,1-di Peroxyketals such as t-butylperoxycyclohexanone, diacyl peroxides such as t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxybenzoate, t-butylperoxy-2 -Peroxye such as ethylhexanoate Mention may be made of the ether system. In addition, organic peroxides as curing agents for commercially available epoxy (meth) acrylate resins can be used. Such commercially available curing agents for epoxy (meth) acrylate resins include trade names “Percure K”, “Percure VL”, “Percure VS” manufactured by NOF Corporation, and trade names “ 328E "and" 328EM ". These can be used alone or in combination of two or more. These organic peroxides may be used in combination with a curing accelerator for the purpose of helping to cleave molecules and generate radicals. For example, conventionally known curings such as tertiary amine compounds such as N, N-dimethylaniline, N, N-diethylaniline, N, N-diethanolaniline, and cobalt salts of organic acids such as cobalt naphthenate and cobalt octenoate. These are accelerators, and these may be used in combination of one or more.

  The amount of the photopolymerization initiator used as the radical polymerization initiator is preferably 0.1 to 30 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyimide (A). Is preferably used. When the amount is less than 0.1 part by weight, polymerization is not promoted by irradiation with ultraviolet rays (light), and the formed film is uncured and causes deterioration of various properties, which is not preferable. When it exceeds 30 weight part, since the heat resistance of hardened | cured material falls, it is unpreferable.

  The amount of the organic peroxide used as the radical polymerization initiator is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyimide (A). It is preferable to use in the range. When the amount is less than 0.01 parts by weight, curing is extremely slow and not practical, which is not preferable. When it exceeds 110 weight part, since the heat resistance of hardened | cured material falls, it is unpreferable.

  If necessary, a reactive diluent may be added to the polyimide resin composition of the present invention within a range that does not impair the properties of the cured product of the polyimide resin composition of the present invention, that is, the pressure-sensitive adhesive. For example, (meth) acrylic acid ester is mentioned as a diluent which has photocurability, For example, hydroxyalkyl (meth) acrylates, such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, Mono- or di (meth) acrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, (meth) acrylamides such as N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N , N-dimethylaminoethyl (meth) acrylate and other aminoalkyl (meth) acrylates, hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydro Polyhydric alcohols such as ciethyl isocyanurate, or polyethylene (meth) acrylates of these ethylene oxide or propylene oxide adducts, phenoxyethyl (meth) acrylate, phenolic ethylene such as polyethoxydi (meth) acrylate of bisphenol A (Meth) acrylates of oxides or propylene oxide adducts, glycidyl ether (meth) acrylates such as glycerin diglycidyl ether, trimethylopropane propane triglycidyl ether, triglycidyl isocyanurate, caprolactone-modified tris (acryloxyethyl) isocyanate Ε-caprolactone-modified (meth) acrylates such as nurate, melamine (meth) acrylate, and the like can be mentioned. Can be used in combination. Examples of the radical polymerizable diluent include those generally used for vinyl ester resins. Specifically, the radical polymerizable diluent having a styrene monomer or a (meth) acryl group includes styrene and Examples of styrene derivatives include derivatives derived from alkyl groups, aromatic groups, ester groups, ether groups, vinyl groups at the α-, o-, m-, and p-positions of styrene, halogens, nitros, and the like. And those having derivatives of cyano and amide, which can be used in combination of one or more. Moreover, you may use combining the diluent which has photocurability, and a radically polymerizable diluent.

  The polyimide resin composition of the present invention may have gelation due to an increase in molecular weight due to reaction of a group containing an acrylic group in Step II when a reactive diluent and a polymerization initiator are included, or during storage. . Therefore, it is preferable to contain a polymerization inhibitor in the production process. As the polymerization inhibitor that can be used in the present invention, conventionally known substances can be used. For example, hydroquinone, methyl hydroquinone, monomethyl ether hydroquinone, monoethyl ether hydroquinone, tol hydroquinone, di-t-4-methylphenol Phenol polymerization inhibitors such as 2,6-di-t-butylhydroxytoluene, phenothiazine, t-butylcatechol, etc. can be mentioned, and phosphorus inhibitors such as triphenylphosphine can be used as polymerization inhibitors or stabilizers. Compounds can be mentioned, but are not limited to these. One or more types can be freely combined. These usage-amounts can be used in 1-10000 ppm with respect to a polyimide (A), Preferably it is 10-5000 ppm. If it is less than 1 ppm, the polymerization inhibition effect is small, gelation occurs during the reaction, and the target compound may not be obtained, or the storage stability of the reaction product may be significantly reduced. On the other hand, when it exceeds 10,000 ppm, the curing reaction in the process of obtaining a cured product of the polyimide resin composition is hindered, and the cured product contains a large amount of uncured product. May not satisfy performance.

  Any conventionally known additive can be added to the polyimide resin composition of the present invention within a range that does not impair the properties of the cured product of the polyimide resin composition of the present invention, that is, the pressure-sensitive adhesive. For example, when a surfactant such as fluorine or polysiloxane is added, a cured product having good surface smoothness can be easily obtained. Hereinafter, inorganic substances such as aluminum hydroxide and calcium carbonate as fillers, inorganic pigments and organic pigments as colorants, silica as thixotropy imparting agents, etc., for the purpose of improving heat resistance, hydroquinone, methylhydroquinone, methoxyhydroquinone, t- Quinone compounds such as butylhydroquinone and parabenzoquinone, thioether compounds such as trade names Adeka Stub AO-412S and Adeka Stub AO-503 (Adeka), trade name Sumilizer GA-80 (Sumitomo Chemical Co., Ltd.), and products Phenol compounds such as name IRGANOX 1010, trade name IRGANOX 1098 (Ciba Specialty Chemicals Co., Ltd.), trade name Adeka Stub AO-20 (Adeka Co., Ltd.), and amines such as trade name Adeka Stub LA-57 (Adeka Co., Ltd.) Compounds, sulfur compounds such as dilauryl 3,3′-thiodipropionate, phosphorus compounds such as trade name ADK STAB HP-10, trade name ADK STAB PEP-36 (Adeca), and phosphate esters as flame retardants UV absorbers, etc. One or more of these may be used simultaneously.

  The polyimide resin composition in the present invention may contain water as a solvent, a small amount of water as a certain additive, and a small amount of water as an impurity.

  Step III will be described. The pressure-sensitive adhesive of the present invention can be obtained by applying a polyimide resin composition on a smooth substrate to form a film and curing it. Alternatively, it may be applied directly on some object and cured. Examples of smooth substrates that can be used include plate-like substrates such as glass, stainless steel, aluminum and copper, and other commercially available materials including polyimides such as polyethylene, PET, trade names Kapton, Apical, Upilex and Neoprim. A thin film substrate including any conventionally known film can be used. Among these, when the heat-resistant thin film substrate including polyimide and the pressure-sensitive adhesive of the present invention are combined as a substrate, a heat-resistant pressure-sensitive adhesive tape can be obtained. Furthermore, when a polyimide film (trade name: Neoprim Mitsubishi Gas Chemical Co., Ltd.) represented by the formula (8) is selected as the base material, a light-colored transparent heat-resistant adhesive tape can be obtained.

（式（８）中、Xは炭素数が２〜３９の２価の脂肪族基、炭素数が３〜３９の２価の脂環族基、炭素数が６〜３９の２価の芳香族基又はこれらの組み合わせからなる２価の基であり、Ｘの主鎖には、−Ｏ−、−ＳＯ_２−、−ＣＨ_２−、−Ｃ（ＣＨ_３）_２−、−ＯＳｉ（ＣＨ_３）_２−、−Ｃ_２Ｈ_４Ｏ−及び−Ｓ−からなる群から選ばれた少なくとも１種の結合基が介在していてもよく、Ｘはカルボキシル基、水酸基及びカルボニル基からなる群から選ばれた少なくとも１種の官能基を有していてもよい）

(In the formula (8), X is a divalent aliphatic group having 2 to 39 carbon atoms, a divalent alicyclic group having 3 to 39 carbon atoms, and a divalent aromatic group having 6 to 39 carbon atoms. A divalent group consisting of a group or a combination thereof, and the main chain of X includes —O—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ). _At least one linking group selected from the group consisting of _2- , -C ₂ H ₄ O- and -S- may be interposed, and X is selected from the group consisting of a carboxyl group, a hydroxyl group and a carbonyl group. And may have at least one functional group)

  The coating method is not particularly limited, and conventionally known methods such as die coater, comma coater, curtain coater, gravure coater, roll coater, spray coater, spin coater, and ink jet can be used.

  When curing after coating, when an organic solvent is used in the polyimide resin composition, it is preferable to first heat the substrate together and distill off the organic solvent to some extent. The temperature is preferably 0 to 120 ° C. The temperature depends on the solvent used and the film thickness. The heating temperature is adjusted according to the volatility of the solvent. For example, if a photosensitive / thermosetting resin composition coating using a solvent having a boiling point of about 60 ° C. is suddenly heat-treated in a dryer at 120 ° C., irregularities may be formed on the surface. A stepwise temperature increase is also preferred when a thick film is to be formed. The total heating time is preferably 0.01 to 3 hours.

  As an irradiation light source for photocuring, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like can be used. A suitable condition for photocuring is irradiation with ultraviolet rays of 10 to 10,000 mJ. There is no restriction | limiting in a light irradiation apparatus, A conventionally well-known apparatus and equipment can be used.

  The polyimide resin composition cured on the substrate, that is, the pressure-sensitive adhesive, may be used as it is left on the substrate, or may be peeled off from the substrate and used as a film. In this case, it is preferable to use a substrate having releasability such as release paper as the substrate. The thickness of the cured product is preferably 0.01 to 2000 μm.

  In addition, you may perform thermosetting after performing photocuring for hardening acceleration. There is no limit to the order and number of times of combining light curing and heat curing. In this case, it is preferable to heat at 60 to 200 ° C. for about 0.01 to 2 hours. When the heating temperature is lower than 60 ° C., it is difficult to achieve the purpose of promoting curing. When the heating temperature is higher than 200 ° C., it tends to be cured in a short time, it becomes difficult to control the curing time, and the pressure-sensitive adhesive tends to be colored.

  The cured product of the polyimide resin composition in the present invention corresponds to a material generally called an adhesive. The adhesive force required as an adhesive is preferably about 0.001 to 250 N / 25 mm as 90-degree peeling adhesive force, and can be used repeatedly. Appropriate adhesive strength and the required number of repeated uses are completely different depending on the nature, application, and method of use of the adherend, and thus cannot be generally shown. Further, after the operation of peeling off the adherend from the adhesive, the state in which the adhesive remains on the adherend surface is referred to as “adhesive residue”, and the difficulty of adhesive residue is referred to as “adhesive residue”. The adhesive residue is generally required to be good.

  The pressure-sensitive adhesive of the present invention has characteristics such as light-color transparency and heat resistance. Therefore, it can be used for a wide range of industrial products such as pressure-sensitive adhesive tapes as applications that require light-colored transparency and / or heat-resistant adhesives that require flexibility and adhesiveness at high temperatures. .

  Examples are shown below, but the present invention is not limited to the following examples. The physical properties were measured by the following method.

<Solution viscosity>
The measurement was performed at 25 ° C. using a TV-20 type cone plate viscometer manufactured by TOKIMEC.

<Thermogravimetric analysis>
Using a thermogravimetric analyzer (DTG-50) manufactured by Shimadzu Corporation, the temperature was raised from room temperature under the condition of a heating rate of 10 ° C./min under a nitrogen stream, kept at 200 ° C. for 30 min, and after removing moisture, 200 ° C. The temperature was raised to 250 ° C. at 5 ° C./min. Then, it hold | maintained at 250 degreeC for 1 hour, and calculated | required weight loss% at the time of 250 degreeC holding | maintenance.

<90 degree peeling adhesive strength>
It calculated | required according to JISZ0237. Cut the adhesive tape on which the light-colored transparent heat-resistant adhesive is formed on the thin film substrate into a width of 10 mm and a length of 150 mm, and paste the light-colored transparent heat-resistant adhesive surface and the aluminum plate together, and press and reciprocate once with a 2 kg rubber roller. After standing for 30 minutes, the adhesive tape was pulled at an angle of 90 degrees at 23 ° C./50% RH under the condition of peeling speed: 300 mm / min, and the 90-degree peeling adhesive force between the adhesive tape and the aluminum plate (N / 10 mm) and measured in units (N / 25 mm). IMADA digital force gauge ZP-5N, IMADA slide type motorized stand MX-500N, and 90-degree peeling jig P90-200N were used as measuring instruments.

<Total light transmittance and YI value>
As an index for evaluating colorlessness and transparency according to the JIS K7105 Transparency Test Method, total light transmittance and YI value were measured using a color difference / turbidity measuring device COI-300A manufactured by Nippon Denshoku Industries Co., Ltd.

<Adhesive residue>
When the 90-degree peel adhesive strength was measured, the surface of the aluminum plate as the adherend was visually evaluated, and those having no adhesive residue were good, and those having adhesive residue were considered bad.

<Amino group concentration>
From the total amine value determined from JIS K 7237, the amino group concentration (meq / g) per 1 g of the measurement object was converted.

Synthesis example 1
<Synthesis of polyimide (A1)>
In a 500 mL five-neck glass round bottom flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 1,2,4,5-cyclohexanetetracarboxylic acid in a nitrogen stream Dianhydride (HPMDA, Mitsubishi Gas Chemical Co., Ltd.) 58.520 g (0.261 mol), ethylene oxide / propylene oxide copolymer bis (2-aminopropyl) ether (trade name: Jeffamine ED-900, Mitsui Chemicals) Fine Co., Ltd., molecular weight: 966.6 (calculated from amine value), a + c in formula (5) = 2.5 (theoretical value), b = 15.5 (theoretical value)) 315.418 g (0.326 mol) ), The temperature was raised to 200 ° C. while stirring at 200 rpm, an imidization reaction was performed for 3 hours, and the generated water was separated by Dean Stark. After 3 hours, it was confirmed that the distillation of water had stopped, and 9.30 g of water was recovered and cooled to room temperature. A liquid polyimide (A1) was obtained at 25 ° C.

Formulation Example 1
<Preparation of polyimide resin composition 1>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen introduction tube, dropping funnel with side tube, and cooling tube, 36.5 g of the polyimide (A1) obtained in Synthesis Example 1 and maleimide compound (product) Name: BMI-2300) 3.5 g, 1,3-dioxolane (Mitsubishi Gas Chemical Co., Ltd.) 160.0 g was weighed, stirred at room temperature (25 ° C.) for 10 minutes to completely dissolve, and a non-volatile concentration of 20. 0% by weight of polyimide resin composition 1 was obtained.

Example 1
<Manufacture of light-colored transparent heat-resistant pressure-sensitive adhesive 1 and light-colored transparent heat-resistant pressure-sensitive adhesive tape 1>
A glass plate having a size of 300 mm × 400 mm and a thickness of 5 mm is placed on a hot plate adjusted to 80 ° C., and further a size of 150 mm × 150 mm, a thickness as a transparent heat-resistant thin film substrate on the glass plate. 100 μm Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd.) was fixed with Kapton tape (Toray DuPont Co., Ltd.). About 1 g of polyimide resin composition 1 is placed on Neoprim L-3430 with a dropper. A 20 bar coater was applied uniformly on Neoprim L-3430. This was left for 10 minutes to evaporate the solvent. Thereafter, the solvent was further distilled off by moving into a hot air dryer at 150 ° C. and leaving it for 5 minutes. Subsequently, using a metal halide lamp (350 nm) as a light source, the light-colored transparent heat-resistant pressure-sensitive adhesive 1 having a thickness of 0.010 mm has a transparent heat resistance when exposed to light and cured under the conditions of an integrated ultraviolet light amount of 3000 mJ / cm ^2. A light-colored transparent heat-resistant adhesive tape 1 formed on the conductive thin film substrate was obtained.
The light-colored transparent heat-resistant pressure-sensitive adhesive tape 1 had a color tone of 90.5% and a YI value of 2.77, and had sufficient light-color transparency. When the 90-degree peeling adhesive strength (N / 25 mm) of the light-colored transparent adhesive tape 1 was determined, it was 1.03 (N / 25 mm), and the adhesive residue was good.

  The pressure-sensitive adhesive of the present invention can be cured at a low temperature and / or in a short time because the polyimide resin composition as a precursor can be cured by light in the UV region. The work process can be streamlined by shortening the time required to obtain energy and improving energy efficiency. The pressure-sensitive adhesive of the present invention has light-color transparency and heat resistance such that it does not decompose even when heated to 250 ° C. Therefore, it can be used for a wide range of industrial products such as pressure-sensitive adhesive tapes as applications that require light-colored transparency and / or heat-resistant adhesives that require flexibility and adhesiveness at high temperatures. .

Claims (13)

A tetracarboxylic acid component comprising one or more compounds selected from the tetracarboxylic dianhydride represented by the formula (1) and the tetracarboxylic acid represented by the formula (2) and a tetracarboxylic acid derivative; The diamine component represented by the formula (4) in which the polyoxyalkylene diamine represented by (3) is 50 mol% or more in the total diamine is 1.01 mol or more of the diamine component per 1 mol of the tetracarboxylic acid component. The polyimide (A) or polyimide (A) organic solvent solution blended at a ratio of 2 mol or less and the maleimide compound are contained at a ratio of 0.05 mol or more and 10 mol or less with respect to 1 mol of the polyimide (A). A pressure-sensitive adhesive obtained by irradiating a polyimide resin composition with ultraviolet rays.

(In formula (1), R ₁ is a tetravalent organic group)

(In Formula (2), R ₁ is a tetravalent organic group, and Y _{1 to} Y ₄ are each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.)

(In Formula (3), X ₁ and X ₂ are each a C _{1 to} C ₄ alkylene group, k and m are each a repeating number of OX ₁ units, l is a repeating number of OX ₂ units, and k + m is a number. The average degree of polymerization is a number within the range of 1 to 90 (m is not 0), and l is the number average degree of polymerization and a number within the range of 0 to 80.)

(In the formula (4), R ₂ is an aliphatic group, a divalent organic group having a carbon number of 1 to 221 consisting of alicyclic group or an aromatic group, an ether group in a part of its structure, a methylene group, Other substituents may be included.) R ₁ in each of formula (1) and formula (2) is at least one selected from a tetravalent group derived from cyclohexane and a tetravalent group derived from benzene, Item 2. The pressure-sensitive adhesive according to item 1. The pressure-sensitive adhesive according to claim 1, wherein R ₁ in each of the formulas (1) and (2) is a tetravalent group derived from cyclohexane. The pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the polyoxyalkylene diamine includes a polyoxyalkylene diamine having a skeleton derived from propylene oxide and ethylene oxide represented by the formula (5). .

(In formula (5), a and c each represent the number of repeating propylene oxide units, and b represents the number of repeating ethylene oxide units.) The pressure-sensitive adhesive according to claim 1, wherein the polyoxyalkylene diamine contains a polyoxyalkylene diamine having a propylene oxide skeleton represented by the formula (6).

(In formula (6), d represents the number of repeating propylene oxide units.) The pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the polyoxyalkylene diamine includes a polyoxyalkylene diamine having a skeleton derived from propylene oxide and butylene oxide represented by the formula (7). Agent.

(In formula (7), e and g each represent the number of repeating propylene oxide units, and f represents the number of repeating butylene oxide units.)   The polyimide (A) is composed of one or more compounds selected from a tetracarboxylic dianhydride represented by the formula (1) and a tetracarboxylic acid represented by the formula (2) and a tetracarboxylic acid derivative. The tetracarboxylic acid component and the diamine component represented by the formula (4) in which the polyoxyalkylene diamine represented by the formula (3) is 50 mol% or more in the total diamine are mixed with the diamine with respect to 1 mol of the tetracarboxylic acid component. The component according to any one of claims 1 to 6, which is obtained by blending the components at a ratio of 1.01 mol or more and 2 mol or less and heating and reacting at a temperature of 160 to 250 ° C for 0.5 to 24 hours. Adhesive.   The pressure-sensitive adhesive according to claim 7, wherein 50% by weight or more of the total solvent in the organic solvent solution of polyimide (A) is 1,3-dioxolane. Any of Claims 1-8 obtained by making the said polyimide resin composition exist for 0.01 to 3 hours in the environment of 0-150 degreeC, and then light-irradiating on the conditions of ultraviolet rays integrated light quantity 1-10000mJ / cm < ² >. The pressure-sensitive adhesive according to crab.   The adhesive tape which formed the adhesive of Claim 9 on the heat resistant thin film base material.   The pressure-sensitive adhesive tape according to claim 10, wherein the heat-resistant thin film substrate has transparency. The adhesive tape whose structure of the heat-resistant thin film base material which has transparency of Claim 11 is a polyimide represented by Formula (8).

(In the formula (8), X is a divalent aliphatic group having 2 to 39 carbon atoms, a divalent alicyclic group having 3 to 39 carbon atoms, and a divalent aromatic group having 6 to 39 carbon atoms. A divalent group consisting of a group or a combination thereof, and the main chain of X includes —O—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ). _At least one linking group selected from the group consisting of _2- , -C ₂ H ₄ O- and -S- may be interposed, and X is selected from the group consisting of a carboxyl group, a hydroxyl group and a carbonyl group. And may have at least one functional group)   The adhesive film which formed the adhesive of Claim 9 on the peeling film.