JP2012218400A - Release material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release material excellent in releasability and abrasion resistance.SOLUTION: The release material includes a copolymer (A) represented by general formulae (I) and (II) and a copolymer (B) before imidization of the copolymer (A) is held on fibers so as to be heated under pressure and imidized simultaneously with pressurization or after pressurization.

Description

  The present invention relates to a release material having excellent release properties and wear resistance.

  The mold release material is used in various forms in various fields where smooth peeling is required. For example, in the manufacture of a solar cell module, a sheet-like release material is used. If it demonstrates concretely, manufacture of a solar cell module will arrange | position the several photovoltaic cell 2 in parallel first, as shown to Fig.1 (a). Subsequently, the protective glass 4 and the back sheet 5 are laminated on both surfaces of each solar battery cell 2 through the sheet-like sealing agents 3 and 3 made of ethylene vinyl acetate resin or the like to obtain the laminate 1.

  As shown in FIG. 1B, when the laminate 1 is sandwiched between a pair of hot plates 50, 50 provided in the laminating apparatus and hot pressed in the direction of arrow A, the sealant 3 is melted. As a result, as shown in FIG.1 (c), the solar cell module 10 by which each photovoltaic cell 2 is sealed with the sealing agent 3 is obtained.

  Here, when the laminated body 1 is hot-pressed, the melted sealing agent 3 may flow out of the laminated body 1 and adhere to the surface of the hot plate 50. In order to prevent the sealing agent 3 from being fused to the surface of the hot plate 50, a release sheet 51 obtained by processing the release material into a sheet shape is disposed on the surface of the hot plate 50.

  The release sheet 51 is usually made by impregnating and holding a glass fiber with a fluororesin (see, for example, Patent Document 1). The sealing agent 3 fused to the release sheet 51 is generally removed by a brush such as a roll brush provided in the laminating apparatus.

  However, the release sheet 51 having the above-described composition has not been sufficient in release properties and wear resistance. For this reason, the conventional release sheet 51 is liable to generate abrasion scratches when the fused sealant 3 is removed with a brush, and therefore has a short life, and generated shavings are mixed into the solar cell module 10. There was a problem that it was easy.

JP-A-9-172192

  The subject of this invention is providing the mold release material which is excellent in mold release property and abrasion resistance.

［式（Ｉ），（II）中、Ｒ₁およびＲ₄は、それぞれ同一または異なる基であって、芳香族環または脂肪族環を含む２価の有機基を示す。Ｒ₂は、重量平均分子量３００〜１０，０００の２価の有機基を示す。Ｒ₃は、芳香族環、脂肪族環または脂肪族鎖を含む２価の有機基を示す。Ｒ₅は、シロキサン結合を有する２価の基を示す。Ｒ₆は、４個以上の炭素を含む４価の有機基を示す。ｎは１〜１００の整数を示す。］
（２）前記繊維が、ガラス繊維である前記（１）記載の離型材。
（３）前記一般式（Ｉ）で表される構造単位と、前記一般式（II）で表される構造単位との共重合比が、重量比で、９９：１〜１：９９である前記（１）または（２）記載の離型材。 As a result of intensive studies to solve the above-described problems, the present inventors have found a solution means having the following configuration and have completed the present invention.
(1) A release material composed of an imide-modified elastomer held in a fiber, wherein the imide-modified elastomer is represented by a structural unit represented by the following general formula (I) and the following general formula (II): It consists of a copolymer (A) with a structural unit, and the copolymer (B) before imidization of this copolymer (A) is held by the fiber and pressurized while heating to a temperature exceeding 100 ° C. At the same time as or after the pressurization, the release agent is obtained by imidizing the copolymer (B).

[In Formulas (I) and (II), R ₁ and R ₄ are the same or different groups, and each represents a divalent organic group containing an aromatic ring or an aliphatic ring. R ₂ represents a divalent organic group having a weight average molecular weight of 300 to 10,000. R ₃ represents a divalent organic group containing an aromatic ring, an aliphatic ring or an aliphatic chain. R ₅ represents a divalent group having a siloxane bond. R ₆ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. ]
(2) The mold release material according to (1), wherein the fiber is glass fiber.
(3) The copolymerization ratio of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is 99: 1 to 1:99 by weight ratio. The release material according to (1) or (2).

［式中、ｘは５または６の整数を示す。ｙは１〜７６の整数を示す。］
（７）前記ポリエステルポリオールが、下記式（２）で表されるポリエステルジオールである前記（５）または（６）記載の離型材。

［式中、ｚは１〜３７の整数を示す。］
（８）前記第２ジアミン化合物が、下記一般式（３）で表される化合物である前記（５）〜（７）のいずれかに記載の離型材。

［式中、Ｒ¹およびＲ²は、それぞれ同一または異なる基であって、アルキレン基を示す。Ｒ³〜Ｒ⁶は、それぞれ同一または異なる基であって、水素、アルキル基、フェニル基を示す。ｍは８〜１６０の整数を示す。］ (4) The copolymer (B) is a polyurethane-urea compound in which a urethane prepolymer having an isocyanate group at both molecular ends obtained from a first diisocyanate and a polyol is chain-extended by a urea bond with a first diamine compound. And the second diisocyanate obtained by reacting a mixture of a polysiloxane-urea compound chain-extended with a second diamine compound having a siloxane bond by a urea bond and a tetracarboxylic dianhydride ( The release material according to any one of 1) to (3).
(5) The mold release material according to (4), wherein the polyol is at least one selected from polycarbonate polyol, polyester polyol, and polyether polyol.
(6) The mold release material according to (5), wherein the polycarbonate polyol is a polycarbonate diol represented by the following formula (1).

[Wherein x represents an integer of 5 or 6. y represents an integer of 1 to 76. ]
(7) The mold release material according to (5) or (6), wherein the polyester polyol is a polyester diol represented by the following formula (2).

[In formula, z shows the integer of 1-37. ]
(8) The mold release material according to any one of (5) to (7), wherein the second diamine compound is a compound represented by the following general formula (3).

[Wherein, R ¹ and R ² are the same or different groups and each represents an alkylene group. R ^{3 to} R ⁶ are the same or different groups, and each represents hydrogen, an alkyl group, or a phenyl group. m represents an integer of 8 to 160. ]

(9) The mold release material according to any one of (1) to (8), wherein a pressure in the pressurization is 0.2 MPa or more.
(10) The mold release material according to any one of (1) to (9), wherein the arithmetic average roughness (Ra) is 10 μm or less.
(11) A release sheet for manufacturing a solar cell module, comprising the release material according to any one of (1) to (10).
(12) A belt comprising the release material according to any one of (1) to (10).

  In addition, the said "imide modified elastomer" in this invention means the elastomer which has an imide component, and is a concept also including resin by the ratio (imide fraction) of the said imide component.

  According to the present invention, the fiber retains the imide-modified elastomer made of the copolymer (A) having a specific composition having releasability and excellent wear resistance. Since the copolymer (B) before imidation of the copolymer (A) is held and pressurized, the surface of the release material becomes smooth, and as a result, the release of the copolymer (A) Can be improved, and therefore excellent mold release properties can be exhibited.

(A)-(c) is a schematic explanatory drawing which shows the general manufacturing method of a solar cell module.

  Hereinafter, an embodiment according to the release material of the present invention will be described. The release material of this embodiment is made of an imide-modified elastomer held on a fiber. Examples of the fibers include inorganic fibers such as glass fibers and alumina fibers; organic fibers such as aramid fibers and wholly aromatic polyester fibers. Glass fibers are particularly preferable. When the imide-modified elastomer is held on such a fiber, the tensile strength of the release material can be improved. Among these exemplified fibers, those having heat resistance are preferable. Physical properties such as fiber mass, thickness, and woven density are not particularly limited.

  The imide-modified elastomer to be held on the fiber is composed of a copolymer (A) of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II). This copolymer (A) has releasability and is excellent in wear resistance.

In the above general formulas (I) and (II), R ₁ and R ₄ are the same or different groups, each representing a divalent organic group containing an aromatic ring or an aliphatic ring. . Examples of the organic group include residues other than the isocyanate group (—NCO) in the first diisocyanate (a) capable of forming a urethane prepolymer (c) together with the polyol (b) according to the reaction process formula (A) described later. And residues other than the isocyanato group (—NCO) in the second diisocyanate (f) that can be chain-extended by a urea bond according to the reaction process formula (C).

R ₂ represents a divalent organic group having a weight average molecular weight of 300 to 10,000, preferably 300 to 5,000. Examples of the organic group include residues excluding two hydroxyl groups (—OH) in the polyol (b) that can form the urethane prepolymer (c) together with the first diisocyanate (a) according to the reaction process formula (A). Is mentioned.

R ₃ represents a divalent organic group containing an aromatic ring, an aliphatic ring or an aliphatic chain. Examples of the organic group include an aromatic diamine compound having 6 to 27 carbon atoms and an aliphatic diamine compound having 6 to 24 carbon atoms that can extend the urethane prepolymer (c) by a urea bond in accordance with the reaction process formula (B), and residues like excluding an amino group (-NH ₂₎ and the like in at least one of the first diamine compound (d) selected from alicyclic diamine compounds having 6 to 24 carbon atoms. The above-mentioned aliphatic chain includes one having 1 carbon.

R ₅ represents a divalent group having a siloxane bond. As the group, for example, the amino group (—NH ₂ ) is excluded from the second diamine compound (g) having a siloxane bond capable of extending the second diisocyanate (f) by a urea bond according to the reaction process formula (C). Examples include residues.

R ₆ represents a tetravalent organic group containing 4 or more carbon atoms. Examples of the organic group include an aromatic tetracarboxylic dianhydride having 6 to 18 carbon atoms and an alicyclic tetracarboxylic acid having 4 to 6 carbon atoms capable of introducing an imide unit into a urea bond portion according to the reaction process formula (D). Examples include residues of at least one tetracarboxylic dianhydride (i) selected from acid dianhydrides.

  N represents an integer of 1 to 100, preferably 2 to 50.

  The copolymer (A) comprises a polyurethane-urea compound obtained by extending a urethane prepolymer having an isocyanate group at both molecular ends obtained from a first diisocyanate and a polyol by a urea bond with a first diamine compound; After mixing the diisocyanate with a polysiloxane-urea compound chain-extended by a urea bond with a second diamine compound having a siloxane bond, each urea bond portion of the polyurethane-urea compound and the polysiloxane-urea compound is mixed. An imide unit is introduced with tetracarboxylic dianhydride. A copolymer (A) can be manufactured through reaction process formula (A)-(D) as shown, for example below.

［式中、Ｒ₁，Ｒ₂，ｎは、前記と同じである。］ [Reaction process formula (A)]

[Wherein R ₁ , R ₂ and n are the same as described above. ]

(Synthesis of urethane prepolymer (c))
As shown in the reaction process formula (A), first, a urethane prepolymer (c) having an isocyanate group at both molecular ends is obtained from the first diisocyanate (a) and the polyol (b). Since the urethane prepolymer (c) has a urethane structural unit, it is excellent in wear resistance and tensile strength.

  Examples of the first diisocyanate (a) include 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), and polymeric. MDI (Cr.MDI), dianisidine diisocyanate (DADL), diphenyl ether diisocyanate (PEDI), pitirylene diisocyanate (TODI), naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HMDI), isophorone Diisocyanate (IPDI), lysine diisocyanate methyl ester (LDI), metaxylylene diisocyanate (MXDI), 2,2,4-trimethylhexamethylene diisocyanate (TMDI), 2,4,4-trimethylhexa Methylene Isocyanate (TMDI), dimer acid diisocyanate (DDI), isopropylidenebis (4-cyclohexyl isocyanate) (IPCI), cyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexane diisocyanate (hydrogenated TDI) , TDI dimer (TT), and the like. These may be used alone or in combination of two or more, and those distilled under reduced pressure are preferably used.

  Examples of the polyol (b) include polyether polyols such as polypropylene glycol (PPG), polyoxytetramethylene glycol (PTMG), and polymer polyols; polycarbonate polyols; polyesters such as adipate polyols (condensed polyester polyols) and polycaprolactone polyols Polybutadiene polyol; acrylic polyol and the like may be mentioned, and these may be used alone or in combination of two or more.

  Of the exemplified polyol (b), at least one selected from polycarbonate polyol, polyester polyol and polyether polyol is preferred. As a result, at least one of a polycarbonate structural unit, a polyester structural unit and a polyether structural unit excellent in wear resistance is introduced into the main chain of the structural unit represented by the general formula (I), so that the copolymer The wear resistance of (A) can be improved.

  The polycarbonate polyol is preferably a polycarbonate diol represented by the formula (1) (hereinafter referred to as “polycarbonate diol (1)”). When the polycarbonate diol (1) is used as the polyol (b), high releasability, heat resistance and wear resistance can be obtained. The polycarbonate diol (1) is a diol component obtained by copolymerizing two components by a carbonate bond, and is a so-called copolymerized polycarbonate diol. Since the polycarbonate diol (1) is liquid at room temperature (23 ° C.), it is excellent in handleability. In the formula (1), x represents an integer of 5 or 6. Said y shows the integer of 1-76, Preferably 6-15.

  Examples of polycarbonate polyols other than polycarbonate diol (1) include polycarbonate polyols obtained by condensation polymerization of polyols (polyhydric alcohols) and phosgene, chloroformate esters, dialkyl carbonates, diallyl carbonates, alkylene carbonates, and the like. Examples of the polyol include 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 1,5-pentanediol, and the dialkyl carbonate. Examples thereof include dimethyl carbonate and diethyl carbonate. Specific examples of the polycarbonate polyol include polycarbonate diols such as polytetramethylene carbonate diol and polyhexamethylene carbonate diol.

  On the other hand, the polyester polyol is preferably a polyester diol represented by the formula (2) (hereinafter referred to as “polyester diol (2)”). When the polyester diol (2) is used as the polyol (b), high releasability, heat resistance and wear resistance can be obtained. The polyester diol (2) is a side chain-containing polyester diol having an ester group and a methyl group as a side chain in the diol component molecule. The polyester diol (2) is excellent in handleability because it is liquid at room temperature (23 ° C.). In the formula (2), z represents an integer of 1 to 37, preferably 3 to 7.

  Examples of polyester polyols other than polyester diol (2) include polyester polyols obtained by condensation polymerization of polycarboxylic acids and polyols, and specific examples include polyethylene adipate, polydiethylene adipate, polypropylene adipate, Polytetramethylene adipate, polyhexamethylene adipate, polyneopentylene adipate, polyol composed of 3-methyl-1,5-pentanediol and adipic acid, polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone, polycaprolactone The polyol obtained by ring-opening diol, (beta) -methyl-delta-valerolactone with ethylene glycol, etc. are mentioned, These may be used 1 type or in mixture of 2 or more types.

  Still other polyester polyols include, for example, terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (mixture), p-hydroxybenzoic acid, trimellitic anhydride, at least one acid selected from ε-caprolactone, β-methyl-δ-valerolactone, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neo Examples thereof include a copolymer with at least one kind of glycol selected from pentyl glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

  The polyol (b) is preferably used after being dried under reduced pressure under conditions of 70 to 90 ° C., 1 to 5 mmHg, and 10 to 30 hours. The weight average molecular weight of the polyol (b) is 100 to 10,000, preferably 300 to 5,000. The weight average molecular weight is a value obtained by measuring the polyol (b) by gel permeation chromatography (GPC) and converting the obtained measurement value to polystyrene.

  The reaction is performed by mixing the first diisocyanate (a) and the polyol (b) at a predetermined ratio, and then at room temperature (23 ° C.) to 90 ° C. for 1 hour in an inert gas atmosphere such as argon gas or nitrogen gas. The reaction may be performed for about 5 hours. The mixing ratio (mole) of the first diisocyanate (a) to the polyol (b) should be in the range of the first diisocyanate (a): polyol (b) = 1.01: 1 to 2: 1. Is preferred.

  The weight average molecular weight of the urethane prepolymer (c) obtained is 300 to 50,000, preferably 500 to 45,000. The weight average molecular weight is a value obtained by measuring the urethane prepolymer (c) by GPC and converting the obtained measurement value into polystyrene.

［式中、Ｒ₁〜Ｒ₃，ｎは、前記と同じである。］ [Reaction process formula (B)]

[Wherein, R _{1 to} R ₃ and n are the same as described above. ]

(Synthesis of polyurethane-urea compound (e))
Using the urethane prepolymer (c) obtained above, the polyurethane-urea compound (e) which is an imide precursor according to the reaction process formula (B) (hereinafter sometimes referred to as “compound (e)”). Is synthesized. That is, the urethane prepolymer (c) is chain-extended with the first diamine compound (d) by a urea bond to obtain the compound (e).

  Examples of the first diamine compound (d) include 1,4-diaminobenzene (alias: p-phenylenediamine, abbreviation: PPD), 1,3-diaminobenzene (alias: m-phenylenediamine, abbreviation: MPD), 2 , 4-diaminotoluene (alias: 2,4-toluenediamine, abbreviation: 2,4-TDA), 4,4′-diaminodiphenylmethane (alias: 4,4′-methylenedianiline, abbreviation: MDA), 4, 4'-diaminodiphenyl ether (alias: 4,4'-oxydianiline, abbreviation: ODA, DPE), 3,4'-diaminodiphenyl ether (alias: 3,4'-oxydianiline, abbreviation: 3,4'-) DPE), 3,3′-dimethyl-4,4′-diaminobiphenyl (also known as o-tolidine, abbreviation: TB), 2,2′-dimethyl-4,4′-dia Nobiphenyl (alias: m-tolidine, abbreviation: m-TB), 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl (abbreviation: TFMB), 3,7-diamino-dimethyldibenzothiophene -5,5-dioxide (alias: o-tolidine sulfone, abbreviation: TSN), 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-bis (4-aminophenyl) sulfide (alias : 4,4'-thiodianiline, abbreviation: ASD), 4,4'-diaminodiphenylsulfone (also known as 4,4'-sulfonyldianiline, abbreviation: ASN), 4,4'-diaminobenzanilide (abbreviation: DABA) ), 1, n-bis (4-aminophenoxy) alkane (n = 3,4,5, abbreviation: DAnMG), 1,3-bis (4-aminophen) Noxy) -2,2-dimethylpropane (abbreviation: DANPG), 1,2-bis [2- (4-aminophenoxy) ethoxy] ethane (abbreviation: DA3EG), 9,9-bis (4-aminophenyl) fluorene (Abbreviation: FDA), 5 (6) -amino-1- (4-aminomethyl) -1,3,3-trimethylindane, 1,4-bis (4-aminophenoxy) benzene (abbreviation: TPE-Q) 1,3-bis (4-aminophenoxy) benzene (alias: resorcinoxydianiline, abbreviation: TPE-R), 1,3-bis (3-aminophenoxy) benzene (abbreviation: APB), 4,4 ′ -Bis (4-aminophenoxy) biphenyl (abbreviation: BAPB), 4,4'-bis (3-aminophenoxy) biphenyl, 2,2-bis (4-aminophenoxyphenyl) propyl Lopan (abbreviation: BAPP), bis [4- (4-aminophenoxy) phenyl] sulfone (abbreviation: BAPS), bis [4- (3-aminophenoxy) phenyl] sulfone (abbreviation: BAPS-M), 2,2 -Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (abbreviation: HFBAPP), 3,3′-dicarboxy-4,4′-diaminodiphenylmethane (abbreviation: MBAA), 4,6-dihydroxy-1 , 3-phenylenediamine (also known as 4,6-diaminoresorcin), 3,3′-dihydroxy-4,4′-diaminobiphenyl (also known as 3,3′-dihydroxybenzidine, abbreviated as HAB), 3,3 ′ , 4,4′-tetraaminobiphenyl (also known as: 3,3′-diaminobenzidine, abbreviation: TAB) and other aromatics having 6 to 27 carbon atoms Amine compounds; 1,6-hexamethylenediamine (HMDA), 1,8-octamethylenediamine (OMDA), 1,9-nonamethylenediamine, 1,12-dodecamethylenediamine (DMDA), 1-amino-3- C6-C24 aliphatic or cycloaliphatic diamine compounds such as aminomethyl-3,5,5-trimethylcyclohexane (also known as isophoronediamine), 4,4'-dicyclohexylmethanediamine, cyclohexanediamine; Examples thereof include silicone diamine compounds such as bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, and these may be used alone or in combination of two or more.

In the reaction, urethane prepolymer (c) and first diamine compound (d) are mixed in an equimolar amount, preferably an NCO / NH ₂ ratio of about 1.0, and then inert such as argon gas or nitrogen gas. What is necessary is just to perform a solution polymerization reaction or a block polymerization reaction in a gas atmosphere at room temperature to 100 ° C. for about 2 hours to 30 hours.

  Examples of the solvent that can be used for the solution polymerization reaction include N, N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), N-hexyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidone, and the like. In particular, N, N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), N-hexyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidone are preferable. These solvents may be used singly or in combination of two or more, and it is preferable to use a solvent that has been dehydrated according to a conventional method.

［式中、Ｒ₄，Ｒ₅は、前記と同じである。］ [Reaction process formula (C)]

[Wherein, R ₄ and R ₅ are the same as defined above. ]

  On the other hand, as shown in the reaction process formula (C), the second diisocyanate (f) is chain-extended with a second diamine compound (g) having a siloxane bond by a urea bond, and is a polysiloxane-imide precursor. A urea compound (h) (hereinafter sometimes referred to as “compound (h)”) is obtained. Since the compound (h) has a siloxane structural unit, it has excellent releasability. The compound (h) is also excellent in water repellency.

  Examples of the second diisocyanate (f) include the same diisocyanates as exemplified for the first diisocyanate (a). The second diisocyanate (f) may be the same diisocyanate as the first diisocyanate (a) or a different diisocyanate.

Although it does not specifically limit as long as it has a siloxane bond as a 2nd diamine compound (g), The compound etc. which are represented with the said General formula (3) are suitable. In the general formula (3), R ¹ and R ² are the same or different groups, and each represents an alkylene group. Examples of the alkylene group include methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, s-butylene group, t-butylene group, pentylene group, isopentylene group, neopentylene group, hexylene. C1-C6 alkylene groups, such as group, are mentioned.

R ^{3 to} R ⁶ are the same or different groups, and each represents hydrogen, an alkyl group, or a phenyl group. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, and hexyl group. And a linear or branched alkyl group having 1 to 10 carbon atoms. m represents an integer of 8 to 160, preferably 10 to 100.

  The second diamine compound (g) is preferably used after drying under reduced pressure under conditions of 50 to 70 ° C., 1 to 5 mmHg, and 1 to 3 hours. The weight average molecular weight of the second diamine compound (g) is 500 to 15,000, preferably 500 to 5,000. The weight average molecular weight is a value obtained by measuring the second diamine compound (g) by GPC and converting the obtained measurement value into polystyrene.

In the reaction, the second diisocyanate (f) and the second diamine compound (g) are mixed in an equimolar amount, preferably an NCO / NH ₂ ratio of about 1.0, and then argon gas, nitrogen gas, etc. What is necessary is just to make a solution polymerization reaction or a block polymerization reaction in room temperature-100 degreeC by inert gas atmosphere in about 2 hours-30 hours. Examples of the solvent that can be used for the solution polymerization reaction include cyclohexanone and the like in addition to the same solvent exemplified in the reaction process formula (B).

［式中、Ｒ₁〜Ｒ₆，ｎは、前記と同じである。］ [Reaction process formula (D)]

[Wherein, R _{1 to} R ₆ and n are the same as described above. ]

(Synthesis of copolymer (A))
Finally, using the compounds (e) and (h) obtained above, a copolymer (A) is synthesized according to the reaction process formula (D). That is, after mixing the compounds (e) and (h), two imide units continuous with tetracarboxylic dianhydride (i) are introduced into each urea bond part of the compounds (e) and (h), Thereby, the copolymer (A) of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is obtained.

［式中、Ｒ₁〜Ｒ₆，ｎは、前記と同じである。］ The obtained copolymer (A) is a copolymer represented by the following general formula (III) in which the respective structural units represented by the general formulas (I) and (II) are randomly copolymerized.

[Wherein, R _{1 to} R ₆ and n are the same as described above. ]

  Examples of the tetracarboxylic dianhydride (i) include pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), biphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride (BPDA). ), Benzophenone-3,4,3 ′, 4′-tetracarboxylic dianhydride (BTDA), diphenylsulfone-3,4,3 ′, 4′-tetracarboxylic dianhydride (DSDA), 4,4 6 carbon atoms such as '-(2,2-hexafluoroisopropylidene) diphthalic dianhydride (6FDA), m (p) -terphenyl-3,4,3', 4'-tetracarboxylic dianhydride To 18 aromatic tetracarboxylic dianhydrides; cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1-carboxymethyl-2,3,5-cyclopentanetricarboxylic acid-2, : 3,5 dianhydride alicyclic tetracarboxylic dianhydride of 4-6 carbon atoms such as, and the like. These may be used alone or in combination.

  In the reaction, compounds (e) and (h) and tetracarboxylic dianhydride (i) are added to a solvent at a predetermined ratio, and the reaction temperature is set to 100 to 100 under an inert gas atmosphere such as argon gas or nitrogen gas. The reaction time may be 300 ° C, preferably 135 to 200 ° C, more preferably 140 to 160 ° C, and the reaction time may be about 1 hour to 10 hours. As a result, a solution containing the copolymer (B) obtained by copolymerizing the compound (e) and the compound (h) (hereinafter referred to as “copolymer (B) solution”) is obtained. A copolymer (B) is a copolymer before imidating a copolymer (A). That is, the copolymer (B) is a precursor of an imide-modified elastomer and is a polyamic acid represented by the following formula (j).

［式中、Ｒ₁〜Ｒ₆，ｎは、前記と同じである。］

[Wherein, R _{1 to} R ₆ and n are the same as described above. ]

  The mixing ratio of the compound (e) and the compound (h) is preferably a weight ratio in terms of solid content and is in the range of compound (e): compound (h) = 99: 1 to 1:99, 99: A range of 1 to 20:80 is more preferable. Thereby, the copolymerization ratio of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is 99: 1 to 1:99 by weight, preferably 99: 1 to 20:80.

  In particular, when the proportion of the compound (e) is increased, the proportion of the urethane structural unit is increased, so that the wear resistance and tensile strength of the copolymer (A) after imidation tend to be improved. When increasing the ratio of the compound (e), the mixing ratio of the compound (e) and the compound (h) is a weight ratio in terms of solid content, and the compound (e): the compound (h) = 99: 1 to 60: A range of 40 is preferable, and a range of 99: 1 to 80:20 is more preferable. Thereby, the copolymerization ratio of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is 99: 1 to 60:40, preferably by weight. 99: 1 to 80:20.

  The mixing of the compounds (e) and (h) with the tetracarboxylic dianhydride (i) is the same as that used in the synthesis of the first diamine compound (d) and the compound (h) used in the synthesis of the compound (e). When the total number of moles of the 2-diamine compound (g) is A and the number of moles of the tetracarboxylic dianhydride (i) is B, the ratio is in the range of A: B = 1: 2 to 1: 2.02. Are preferably mixed together. Thereby, an imide unit can be reliably introduced into the urea bond portion.

  Examples of the solvent that can be used include the same solvents exemplified in the solution polymerization reaction of the reaction process formulas (B) and (C). In the reaction process formulas (B) and (C), when the compounds (e) and (h) are obtained by a solution polymerization reaction, the reaction may be performed in the solvent.

  Next, the copolymer (B) obtained above is imidized (dehydration condensation reaction) to obtain a copolymer (A). The imidization may be performed under the condition that the copolymer (B) is not thermally decomposed. Specifically, the reaction temperature may be 150 to 250 ° C. and the reaction time may be about 90 to 150 minutes. Prior to imidization, the solvent may be volatilized by heat-treating the copolymer (B) under conditions of about 70 to 200 ° C. and about 20 minutes to 3 hours.

  Here, the mold release material of the present embodiment holds the copolymer (B) on the above-mentioned fiber and pressurizes it while heating it to a temperature exceeding 100 ° C., and at the same time as the pressurization or after the pressurization. It is formed by imidizing the polymer (B). That is, the copolymer (B) before imidation has lower rigidity than the copolymer (A) after imidization. The copolymer (B) is held on the fiber to a temperature exceeding 100 ° C, preferably exceeding 100 ° C and not more than 230 ° C, more preferably 110 to 230 ° C, still more preferably 120 to 220 ° C, still more preferably 130 to When the pressure is applied while heating to 210 ° C., the copolymer (B) becomes moderately flexible, the irregularities of the fibers are covered with the copolymer (B), and the surface of the release material becomes smooth. Specifically, arithmetic mean roughness (Ra) measured using a laser microscope “VK-8710” manufactured by KEYENCE in accordance with JIS B 0601 1994 (surface roughness—definition and display) is usually It becomes 10 micrometers or less, Preferably it becomes 4-10 micrometers. As a result, the releasability of the copolymer (A) is improved, and excellent releasability can be obtained.

  As a method for holding the copolymer (B) on the fiber, a dipping method in which the fiber is dipped in the copolymer (B) solution and pulled up is preferable for efficient holding. Moreover, it may replace with a dip method and may be made to imidize, after coating a copolymer (B) solution with a roll to roll on a fiber. Further, the copolymer (B) solution may be applied to the fiber or sprayed and then imidized.

  Heating can be performed using a heating means such as a heater. The pressurization can be performed using various press devices such as a belt press device and a roll press device in addition to a press device provided with a pair of hot plates. When a belt press device, a roll press device, or the like is employed, pressure can be continuously applied. The pressure in the pressurization is preferably 0.2 MPa or more, more preferably 0.2 to 10 MPa, and further preferably 0.4 to 10 MPa.

  On the other hand, the weight average molecular weight of the copolymer (A) obtained by imidizing the copolymer (B) is preferably 10,000 to 1,000,000, and 15,000 to 150,000. More preferably, it is 20,000-100,000. If the weight average molecular weight of the copolymer (A) is too small, the heat resistance and the wear resistance may be lowered, and if too large, the moldability may be lowered. The weight average molecular weight is a value derived from a value obtained by measuring the copolymer (B) by GPC and converting the obtained measurement value into polystyrene. The reason why the copolymer (B), not the copolymer (A) is measured by GPC is that the copolymer (A) is insoluble in the GPC measurement solvent.

  The elastic modulus of the imide-modified elastomer comprising the copolymer (A) can be arbitrarily adjusted by adjusting the imide fraction, that is, the ratio of the imide component in the imide-modified elastomer. The imide fraction may be arbitrarily selected according to the elastic modulus and the like, and is not particularly limited, but is usually 5 to 45% by weight, preferably 5 to 40% by weight.

  The imide fraction is determined based on the first diisocyanate (a), polyol (b), first diamine compound (d), second diisocyanate (f), second diamine compound (g), compound (e), ( h) is a value calculated from the charged amounts of tetracarboxylic dianhydride (i), and is a value calculated from the following formula (α).

The elastic modulus of the imide-modified elastomer adjusted by the imide fraction is preferably about 1.0 × 10 ^{6 to} 1.0 × 10 ⁹ Pa. As will be described later, the elastic modulus is a value of the storage elastic modulus E ′ at 50 ° C. obtained by measurement using a dynamic viscoelasticity measuring device.

  The mold release material of the present embodiment can be used for, for example, a heat sealing application, a non-adhesive application, a heat treatment application, a plastic processing application, a high-frequency drying application, etc., in addition to a solar cell module manufacturing application. If a specific example is given, the release sheet for solar cell module manufacture which consists of a mold release material of this embodiment, the belt which consists of a mold release material of this embodiment, etc. are mentioned.

  Examples of the belt described above include a food transport belt, a substrate transport belt, a transport belt used in an adhesive use process, a polymer synthesis process, and the like, a driving belt, a suction (perforated) belt, and the like. In particular, since the wear resistance is required in an application in which a belt surface cleaning process using a brush or the like is incorporated, the belt made of the release material of the present embodiment can be particularly preferably used.

  The belt described above may be an endless endless belt having a joint portion in which both ends of the cut belt are abutted by heat press and welded as described in the embodiments described later, or a seamless belt without a joint portion. It may be.

Pressurization while heating to a temperature exceeding 100 ° C. before imidization of the copolymer (B) held in the fiber when producing an endless endless belt having a joint portion is performed before forming the joint portion. It may be present at the same time as or after formation of the joint portion. Further, when producing an endless endless belt having a joint portion, a sheet made of the copolymer (B) is separately prepared, and this sheet is placed on one side or both sides of the belt located at the abutting portion at both ends of the belt. It is preferable to heat laminate in this state.
On the other hand, a seamless belt without a joint portion is excellent in durability, and can be produced by, for example, a centrifugal molding method.

  Moreover, since the release material of this embodiment has rubber elasticity, it can also be used for a diaphragm, packing, a gasket, etc., for example. Applications of the release material of the present embodiment are not limited to these exemplified applications, and can be suitably used in fields where release properties and wear resistance are required.

  As mentioned above, although preferred embodiment concerning this invention was described, it cannot be overemphasized that this invention can be made arbitrary, unless it deviates from the summary of this invention, and is not limited to embodiment mentioned above. For example, although the fiber concerning one Embodiment mentioned above is used as a holding material which hold | maintains an imide modified elastomer, it can be used also as a filler (filler). Moreover, you may use combining the filler which consists of the said fiber, and another filler. Furthermore, it may replace with the filler consisting of the said fiber, and may use only another filler. Examples of other fillers include reinforcing fillers such as short fibers and long fibers, carbon black, carbon nanotubes, and silica; inorganic fillers; nanosize fillers, and various other known fillers can be used. . Furthermore, it can be compounded with those taking the form of non-woven fabric or woven fabric.

  As a method for adding a filler to the imide-modified elastomer, various known methods can be employed. For example, fillers may be kneaded into the imide-modified elastomer using a roll, intermix, banbury, etc., or the filler may be filled into the imide-modified elastomer with an extruder such as a twin screw extruder. Good. When the filler is soluble in the solvent, it may be kneaded into the imide-modified elastomer in a state where the filler is dissolved in the solvent. Alternatively, the filler may be filled with a liquid at an intermediate stage before obtaining the imide-modified elastomer or a chemical used for the synthesis of the imide-modified elastomer and then the synthesis may be completed. Other configurations are the same as those of the release material according to the above-described embodiment.

  Moreover, in one Embodiment mentioned above, although the copolymer (B) which is a precursor of an imide modified elastomer is hold | maintained to a fiber, it replaces with this copolymer (B), and has a release property, In addition, a polymer precursor having excellent wear resistance is used, and this precursor is held in a fiber and heated and pressurized, and at the same time as or after the heating and pressing, the precursor is reacted. You may do it.

  EXAMPLES Hereinafter, although a synthesis example and an Example are given and this invention is demonstrated in detail, this invention is not limited only to the following synthesis examples and Examples.

  The copolymer (B) was synthesized based on the reaction process formulas (A) to (D) described above. The materials used in the synthesis examples are as follows.

-1st, 2nd diisocyanate (a), (f): The brand name "Cosmonate PH" by Mitsui Chemicals, Inc. which is 4,4'- diphenylmethane diisocyanate was used.
Polyol (b): “Duranol T5652” manufactured by Asahi Kasei Chemicals Corporation, which is polycarbonate diol (1), was used. This polycarbonate diol (1) has a weight average molecular weight of 2,000. In the formula (1), x represents 5 or 6, and y represents an integer of 14 to 15.
First diamine compound (d): Trade name “MDA-220” manufactured by Mitsui Chemicals, Inc., which is 4,4′-diaminodiphenylmethane, was used.
Second diamine compound (g): Trade name “X-22-161B” manufactured by Shin-Etsu Chemical Co., Ltd., which is a compound represented by the general formula (3), was used. In this compound, R ¹ and R ^{2 in the} general formula (3) each represent a propylene group. R ^{3 to} R ⁶ all represent a methyl group. m shows the integer of 30-40.
Tetracarboxylic dianhydride (i): pyromellitic anhydride manufactured by Mitsubishi Gas Chemical Co., Ltd. was used.

<Synthesis example>
(Synthesis of urethane prepolymer (c))
First, the first diisocyanate (a) was distilled under reduced pressure, and the polyol (b) was dried under reduced pressure under conditions of 80 ° C., 2-3 mmHg, 24 hours. Next, 35 g of the first diisocyanate (a) and 140 g of the polyol (b) were respectively added to a 500 ml four-necked separable flask equipped with a stirrer and a gas introduction tube, and the mixture was heated at 80 ° C. under a nitrogen gas atmosphere. The mixture was stirred for a time to obtain a urethane prepolymer (c) having isocyanato groups at both molecular ends. As a result of measuring this urethane prepolymer (c) by GPC, the weight average molecular weight was 11,000 in terms of polystyrene conversion.

(Synthesis of polyurethane-urea compound (e))
First, the first diamine compound (d) was weighed so that the total solid concentration of the first diamine compound (d) and the urethane prepolymer (c) was 15% by weight. Dissolved in addition to N-methyl-2-pyrrolidone (NMP). Then, the total amount of this solution was added to the urethane prepolymer (c) obtained above to obtain a mixed solution. In this mixed solution, the ratio of the remaining isocyanate (residual isocyanate group) and the amine was equimolar. This mixed solution was stirred at room temperature (23 ° C.) for 24 hours under a nitrogen gas atmosphere to obtain a polyurethane-urea compound (e) solution having a solid concentration of 15% by weight.

(Synthesis of polysiloxane-urea compound (h))
First, 205.77 g of the second diamine compound (g) was added to a 500 ml four-necked separable flask equipped with a stirrer and a gas introduction tube, and dried under reduced pressure at 60 ° C., 2-3 mmHg for 2 hours. Next, the second diamine compound (g) was dissolved with 150 g of cyclohexanone so that the solid content concentration was 60% by weight.

  To this solution was added 17.43 g of the second diisocyanate (f), and the mixture was stirred at 60 ° C. for 4 hours in a nitrogen gas atmosphere. Thus, a solution of the polysiloxane-urea compound (h) was obtained. The polysiloxane-urea compound (h) solution was adjusted to a solid content concentration of 15% by weight in addition to 1125 g of cyclohexanone.

(Synthesis of copolymer (B))
First, the polysiloxane-urea compound (h) solution was added to the polyurethane-urea compound (e) solution obtained above and stirred. The mixing ratio of the compound (e) and the compound (h) was a weight ratio in terms of solid content, and the compound (e): the compound (h) was 90:10.

  Then, after raising the temperature from room temperature (23 ° C.) to 150 ° C. in a nitrogen gas atmosphere, tetracarboxylic dianhydride (i) was added at a predetermined ratio. A predetermined amount of NMP was further added to this solution so that the solid concentration was 15% by weight, and the mixture was stirred at 150 ° C. for 7 hours to obtain a copolymer (B) solution.

(Physical properties of copolymer (A))
As physical properties of the copolymer (A) obtained from the copolymer (B) solution, an imide fraction, an elastic modulus and a weight average molecular weight were measured. Specifically, first, the obtained copolymer (B) solution was poured into a mold of a centrifugal molding machine, and the copolymer (B) was molded into a sheet by centrifugal molding at 120 ° C. and 300 rpm for 2 hours. . Subsequently, the copolymer (B) formed into a sheet shape is imidized by heat treatment (dehydration condensation reaction) at 200 ° C. for 2 hours in a vacuum desiccator together with the mold, and n in the general formula (I) is 1 A sheet-like copolymer (A) having a thickness of ˜100 and a thickness of 0.1 mm was obtained. About this copolymer (A), the imide fraction, the elasticity modulus, and the weight average molecular weight were measured.

The measurement results are as follows.
-Imide fraction: 28% by weight
Elastic modulus: 2 × 10 ⁸ Pa
-Weight average molecular weight: 44,000

In addition, the imide fraction was calculated from the formula (α) described above. The elastic modulus is 50 ° C. in a temperature rising process of 10 Hz, 5 ° C./min, −100 to 400 ° C. using a dynamic viscoelasticity measuring device “DMS 6100” manufactured by Seiko Instruments Inc. The storage elastic modulus E ′ of was measured. The weight average molecular weight was derived from a value obtained by measuring the copolymer (B) by GPC and converting the obtained measurement value into polystyrene. Further, the copolymer (A), results of measuring the IR spectrum at ATR method, 1780 cm ^-1, absorption derived from the imide ring to 1720 cm ^-1 and 1380 cm ^-1 was observed.

[Example I]
<Production of release material>
First, the obtained copolymer (B) solution was coated on the fiber with a roll-to-roll, and heat-treated at 80 ° C. for 30 minutes, whereby the copolymer (B) was held on the fiber. The fibers used are as follows.
Fiber: Glass fiber “H201 M 104F” manufactured by Unitika Ltd. was used. This glass fiber has a mass of 210 g / m ² , a thickness of 0.18 mm, a plain weave, and a weave density (length × width) of 42 × 32/25 mm.

  Next, the copolymer (B) held on the glass fiber is pressurized, and after the pressing, the copolymer (B) is imidized by heating treatment (dehydration condensation reaction) at 200 ° C. for 2 hours to form glass. Sheet-shaped release materials having a thickness of 0.4 mm made of the copolymer (A) held on the fibers were obtained (Sample Nos. I-1 to 6 in Table 1).

  The pressurization was performed by sandwiching the copolymer (B) held on the glass fiber between a pair of hot plates provided in the press device. In this pressing apparatus, an elastic layer made of a woven fabric and rubber laminate and a release layer made of polytetrafluoroethylene are laminated in this order on the surfaces of the opposing hot plates. Moreover, the heater is incorporated in the hot plate so that the surface temperature can be controlled.

The pressurizing conditions are as follows.
-Pressure: As shown in Table 1.
・ Temperature: 190 ℃
・ Time: 10 minutes

<Evaluation>
Each of the obtained release materials (Sample Nos. I-1 to 6 in Table 1) and Chuko Kasei Kogyo, which is a sheet-like release material having a thickness of 0.24 mm made of polytetrafluoroethylene held on glass fibers 180 degree peeling strength was evaluated about "FGF-500-10" (sample No. I-7 in Table 1) manufactured by the company. The evaluation method is shown below, and the results are shown in Table 1.

(180 ° peel strength)
First, the release material was pressed and fused to a sheet of ethylene vinyl acetate resin having a width of 100 mm and a thickness of 0.15 mm while applying a temperature of 150 ° C. Subsequently, the release material was peeled 180 ° from the sheet at a rate of 300 mm / min using a load cell under an ambient temperature of 23 ° C., and the 180 ° peel strength was measured in accordance with JIS Z0237.

  As is apparent from Table 1, the copolymer (B) is held on the glass fiber and pressurized while heating to a temperature exceeding 100 ° C., and sample No. is obtained by imidizing the copolymer (B) after pressurization. . I-2 to 6 are sample Nos. Obtained by imidizing the copolymer (B) without applying pressure. Sample No. 1 consisting of I-1 and polytetrafluoroethylene held on glass fiber. Since the value of 180 ° peel strength is smaller than that of I-7, it can be seen that the mold release property is excellent.

Example II
Sample No. shown in Table 2 Using the release materials according to II-1 to 12, the 180 ° peel strength was evaluated in the same manner as in Example I described above, and the arithmetic average roughness (Ra) and the Taber abrasion amount were evaluated.

Specifically, a sheet-like sheet having a thickness of 0.4 mm made of the copolymer (A) held on the glass fiber is performed in the same manner as in Example I described above except that the pressurizing condition is as follows. A release material was obtained (Sample Nos. II-1 to 9 in Table 2).
・ Pressure: 8.4 MPa
-Temperature: As shown in Table 2.
・ Time: 10 minutes

Further, the copolymer (A) held on the glass fiber in the same manner as in Example I described above except that the pressure condition was as follows and the copolymer (B) was imidized simultaneously with the pressure. A sheet-like release material having a thickness of 0.4 mm was obtained (Sample No. II-10 in Table 2).
・ Pressure: 8.4 MPa
-Temperature: As shown in Table 2.
・ Time: 2 hours

  The copolymer (B) held on the glass fiber in the same manner as in Example I described above was subjected to heat treatment at 200 ° C. for 2 hours to imidize, and then the sample No. described above was used. A sheet-like release material having a thickness of 0.4 mm made of the copolymer (A) held on the glass fiber was obtained in the same manner as in II-1 to II-9 (sample No. 2 in Table 2). II-11).

  Sample No. shown in Table 2 As the release material according to II-12, the above-mentioned sample No. The same mold release material as I-7, that is, “FGF-500-10” manufactured by Chuko Kasei Kogyo Co., Ltd., which is a sheet-like mold release material having a thickness of 0.24 mm made of polytetrafluoroethylene held on glass fiber, was used. .

(Arithmetic mean roughness (Ra))
Measurement was performed using a laser microscope “VK-8710” manufactured by KEYENCE in accordance with JIS B 0601 1994 (surface roughness—definition and display).

(Taber wear)
In accordance with JIS K 7204 1999 (Plastics-Wear test method using wear wheels), the release material when the wear wheel H-18 of the Taber wear tester "5150 ABRASER" manufactured by Yasuda Seiki Seisakusho Co., Ltd. is rotated 1000 times. The amount of wear was measured.

  As is clear from Table 2, the copolymer (B) is held on the glass fiber and pressurized while heating to a temperature exceeding 100 ° C., and sample No. is obtained by imidizing the copolymer (B) after pressurization. . II-5 to 9 and sample No. obtained by imidizing the copolymer (B) simultaneously with pressurization. II-10 is Sample No. obtained by imidizing the copolymer (B) without applying pressure. II-1, sample No. whose temperature in pressurization is 100 degrees C or less II-2-4, Sample No. obtained by pressurizing after imidizing the copolymer (B). Sample No. II consisting of II-11 and polytetrafluoroethylene held on glass fiber. Since the 180 ° peel strength value is smaller than that of II-12, it can be seen that the mold release property is excellent. Sample No. II-5 to 10 are sample Nos. Made of polytetrafluoroethylene held on glass fibers. Since the value of the Taber abrasion amount is smaller than that of II-12, it can be seen that the abrasion resistance is also excellent.

Example III
<Production of belt>
First, in the same manner as in Example I described above, a 0.4 mm-thick sheet (a) made of the copolymer (B) held on glass fibers was obtained. Separately, the copolymer (B) solution obtained in the above synthesis example was formed into a film by casting to obtain a sheet (b) having a thickness of 0.1 mm made of the copolymer (B). The sheet (b) is used for bonding of meshing portions (joint portions) at both ends of the belt, which will be described later, and the copolymer (B) is not held by glass fibers.

  Of the obtained sheets (a) and (b), a belt was cut out from the sheet (a) into a belt shape having a width of 20 mm and a length of 1,000 mm, and both ends of the cut-out belt were punched into a saw blade shape. Specifically, both ends of the belt were punched into a saw blade shape such that the distance between the tops of the adjacent peaks was 10 mm and the distance from the top to the bottom was 70 mm.

  Next, after punching the both ends of the sawtooth belt, the above-described sheet (b) formed into a shape having a width of 20 mm and a length of 70 mm is laminated on one side of the belt positioned at the engagement portion, The entire belt was pressurized.

  The pressurization was performed using the same press apparatus as in Example I described above. Specifically, after pressurizing by sandwiching a part of the belt between the pair of hot plates included in the press device described above, the belt is shifted, and a part of the unpressurized belt is sandwiched between the pair of hot plates. The operation of applying pressure was repeated, and the entire belt was pressurized.

The pressurizing conditions are as follows.
・ Pressure: 0.4 MPa
・ Temperature: 170 ℃
・ Time: 10 minutes

  And after pressurization, each copolymer (B) which comprises a belt and a sheet | seat (b) was heat-processed at 200 degreeC over 2 hours, and imidized, and the endless flat belt which has a joint part was obtained. (Sample No. III-1 in Table 3).

  On the other hand, the sample No. in Example II described above. II-11 release material, that is, a sheet-like release material having a thickness of 0.4 mm, which is made of the copolymer (A) held on the glass fiber and pressurized after imidizing the copolymer (B). The belt was cut out into a belt shape having a width of 20 mm and a length of 1,000 mm, and both ends of the cut-out belt were connected to the above-described sample No. It was punched into a saw blade in the same manner as III-1.

  Next, after the punched saw blade-shaped belts are engaged with each other, the above-mentioned sample No. A sheet (b) having a width of 20 mm and a length of 70 mm obtained in the same manner as in III-1 was laminated on one side of the belt located at the meshing portion, and the belt was pressurized.

  For the pressurization, the sample No. described above was used except that only the belt positioned at the meshing portion was pressurized. It carried out like III-1. And after pressurization, the copolymer (B) which comprises a sheet | seat (b) was heat-processed at 200 degreeC over 2 hours, and imidized, and the endless flat belt which has a joint part was obtained (in Table 3). Sample No. III-2).

<Evaluation>
A tensile test was performed on the obtained flat belt. The evaluation method is shown below, and the results are shown in Table 3.

(Tensile test)
A belt main body test piece was cut out in a strip shape having a width of 20 mm and a length of 100 mm from a belt main body portion located in a region without a joint portion of the flat belt. Moreover, the joint part test piece was cut out in the strip shape of width 20mm and length 100mm from the area | region containing a joint part among flat belts.

  About each cut-out test piece, the tensile strength was measured on condition of 200 mm / min of tensile speed based on JISK6251. The obtained measured value was applied to the formula: (tensile strength of joint part test piece / tensile strength of belt body part test piece) × 100, and joint efficiency (%) was calculated.

  As apparent from Table 3, the sample No. III-1 is sample no. It can be seen that the tensile strength of the joint is higher than that of III-2 and the joint efficiency is also excellent. Also, an endless belt excellent in releasability and wear resistance could be provided.

DESCRIPTION OF SYMBOLS 1 Laminate 2 Solar cell 3 Sealant 4 Protective glass 5 Back sheet 10 Solar cell module 50 Hot plate 51 Release sheet

Claims (12)

A release material made of an imide-modified elastomer held in a fiber,
The imide-modified elastomer comprises a copolymer (A) of a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (II):
The copolymer (B) before imidation of the copolymer (A) is pressed while being heated to a temperature exceeding 100 ° C. while being held by the fiber, and at the same time as or after pressurization. A mold release material obtained by imidizing the copolymer (B).

[In Formulas (I) and (II), R ₁ and R ₄ are the same or different groups, and each represents a divalent organic group containing an aromatic ring or an aliphatic ring. R ₂ represents a divalent organic group having a weight average molecular weight of 300 to 10,000. R ₃ represents a divalent organic group containing an aromatic ring, an aliphatic ring or an aliphatic chain. R ₅ represents a divalent group having a siloxane bond. R ₆ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. ]   The mold release material according to claim 1, wherein the fibers are glass fibers.   The copolymerization ratio of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is 99: 1 to 1:99 in terms of weight ratio. 2. A release material according to 2. The copolymer (B) is
A polyurethane-urea compound obtained by chain-extending a urethane prepolymer having an isocyanate group at both molecular ends obtained from the first diisocyanate and polyol with a first diamine compound by a urea bond;
A polysiloxane-urea compound obtained by chain-extending a second diisocyanate with a second diamine compound having a siloxane bond by a urea bond;
The mold release material according to any one of claims 1 to 3, which is obtained by reacting a mixture with tetracarboxylic dianhydride.   The mold release material according to claim 4, wherein the polyol is at least one selected from polycarbonate polyol, polyester polyol, and polyether polyol. The mold release material according to claim 5, wherein the polycarbonate polyol is a polycarbonate diol represented by the following formula (1).

[Wherein x represents an integer of 5 or 6. y represents an integer of 1 to 76. ] The mold release material according to claim 5 or 6, wherein the polyester polyol is a polyester diol represented by the following formula (2).

[In formula, z shows the integer of 1-37. ] The mold release material according to any one of claims 5 to 7, wherein the second diamine compound is a compound represented by the following general formula (3).

[Wherein, R ¹ and R ² are the same or different groups and each represents an alkylene group. R ^{3 to} R ⁶ are the same or different groups, and each represents hydrogen, an alkyl group, or a phenyl group. m represents an integer of 8 to 160. ]   The release material according to any one of claims 1 to 8, wherein a pressure in the pressurization is 0.2 MPa or more.   Arithmetic mean roughness (Ra) is 10 micrometers or less, The mold release material in any one of Claims 1-9.   A release sheet for producing a solar cell module, comprising the release material according to any one of claims 1 to 10.   The belt which consists of a mold release material in any one of Claims 1-10.

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