JP5437055B2 - Release material - Google Patents

Description

  The present invention relates to a release material having heat resistance and durability.

  Depending on the application of the release material, not only the release properties but also heat resistance and durability are required (for example, see Patent Documents 1 and 2). For example, the mold release material which requires the said physical property is used for manufacture of a solar cell module.

  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. 1 (b), the laminated body 1 is disposed between a pair of hot plates 50, 50 included in the laminating apparatus, and then the pair of hot plates 50, 50 are moved in the direction of arrow A, so that the laminated body 1 When the both surfaces are sandwiched while being heated by the pair of hot plates 50, 50, the sealant 3 is melted. As a result, as shown in FIG. 1C, a solar cell module 10 in which each solar cell 2 is sealed with the sealant 3 is obtained.

  Here, when the laminate 1 is heated, the melted sealing agent 3 may flow out of the laminate 1 and adhere to the hot plate 50. In order to prevent fusion between the hot plate 50 and the sealant 3, a release sheet 51 obtained by processing a release material into a sheet shape is disposed on the surface of the hot plate 50 facing the laminate 1. The release sheet 51 is usually made by impregnating and holding a glass fiber with a fluororesin (see, for example, Patent Document 3).

  However, although the release sheet 51 having the above composition has heat resistance, the release property is not sufficient, and therefore a brush or the like for peeling off the fused sealing agent 3 from the release sheet 51 is manufactured. It was necessary to provide in. Further, when the sealant 3 is peeled off with a brush or the like, the surface of the release sheet 51 is likely to be worn and there is a problem in durability. Therefore, development of a release material having physical properties such as heat resistance and durability as well as release properties has been desired.

Japanese Patent Laid-Open No. 5-117608 JP-A-7-11581 JP-A-9-172192

  The subject of this invention is providing the mold release material excellent in mold release property, heat resistance, and durability.

［式中、Ｒ₁は、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。Ｒ₄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。ｍは２〜１００の整数を示す。］
（２）前記イミド変性エラストマーは、ジイソシアナートとポリオールから得た分子両末端にイソシアナート基を有するウレタンプレポリマーをジアミン化合物でウレア結合により鎖延長し、テトラカルボン酸二無水物でウレア結合部にイミドユニットを導入したブロック共重合体である前記（１）記載の離型材。
（３）前記ポリオールが、ポリエステルポリオールおよびポリカーボネートポリオールから選ばれる少なくとも１種である前記（２）記載の離型材。
（４）前記ポリエステルポリオールが、下記式（ｉ）で表されるポリエステルジオールである前記（３）記載の離型材。

［式中、ｘは１〜３７の整数を示す。］
（５）前記ポリカーボネートポリオールが、下記式（ii）で表されるポリカーボネートジオールである前記（３）または（４）記載の離型材。

［式中、ｙは５または６の整数を示す。ｚは１〜７６の整数を示す。］ 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 mold release material comprising an imide-modified elastomer represented by the following general formula (I).

[Wherein, R ₁ 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 ₄ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. m shows the integer of 2-100. ]
(2) The imide-modified elastomer is obtained by extending a urethane prepolymer having an isocyanate group at both molecular ends obtained from diisocyanate and polyol with a diamine compound by a urea bond, and using a tetracarboxylic dianhydride as a urea bond part. The mold release material according to the above (1), which is a block copolymer in which an imide unit is introduced.
(3) The mold release material according to (2), wherein the polyol is at least one selected from polyester polyol and polycarbonate polyol.
(4) The mold release material according to (3), wherein the polyester polyol is a polyester diol represented by the following formula (i).

[Wherein, x represents an integer of 1 to 37. ]
(5) The mold release material according to (3) or (4), wherein the polycarbonate polyol is a polycarbonate diol represented by the following formula (ii).

[Wherein y represents an integer of 5 or 6. z shows the integer of 1-76. ]

［式中、Ｒ₁は、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。Ｒ₄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。ｍは２〜１００の整数を示す。］
（７）前記耐熱性繊維が、ガラス繊維である前記（６）記載の離型材。 (6) A mold release material comprising an imide-modified elastomer represented by the following general formula (I), which is held in a heat resistant fiber.

[Wherein, R ₁ 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 ₄ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. m shows the integer of 2-100. ]
(7) The mold release material according to (6), wherein the heat resistant fiber is glass fiber.

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.
The “release material” in the present invention is usually in the form of a sheet or film, but may be in other forms such as a belt or film as long as the effects of the present invention are not impaired.

  The mold release material of the present invention has an effect that high mold release property, heat resistance and durability can be obtained by using the imide-modified elastomer represented by the general formula (I). In addition, since the imide-modified elastomer can be produced relatively easily, the cost can be reduced.

(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 according to the present embodiment may be referred to as an imide-modified elastomer represented by the general formula (I) in which two imide units continuous in the main chain are introduced (hereinafter referred to as “imide-modified elastomer (I)”). There is.)

In the general formula (I), R ₁ represents a divalent organic group containing an aromatic ring or an aliphatic ring. Examples of the organic group include a polyol according to a reaction process formula (A) described later. Examples include residues other than the isocyanate group (—NCO) in the diisocyanate (a) that can form the urethane prepolymer (c) together with (b).

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 diisocyanate according to the reaction process formula (A). Examples of the polyol (b) that can form a urethane prepolymer (c) together with (a) include residues other than two hydroxyl groups (—OH).

R ₃ represents a divalent organic group containing an aromatic ring, an aliphatic ring, or an aliphatic chain. Examples of the organic group include urethane prepolymers (c) according to a reaction process formula (B) described later. ) At least one diamine selected from aromatic diamine compounds having 6 to 27 carbon atoms, aliphatic diamine compounds having 6 to 24 carbon atoms and alicyclic diamine compounds having 6 to 24 carbon atoms Examples of the compound (d) include a residue excluding an amino group (—NH ₂ ). The aliphatic chain includes one having 1 carbon.

R ₄ represents a tetravalent organic group containing 4 or more carbons, and examples of the organic group include carbon capable of introducing an imide unit into a urea bond portion according to a reaction process formula (C) described later, for example. A residue of at least one tetracarboxylic dianhydride (f) selected from an aromatic tetracarboxylic dianhydride having 6 to 18 carbon atoms and an alicyclic tetracarboxylic dianhydride having 4 to 6 carbon atoms; Can be mentioned.

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

  The imide-modified elastomer (I) is obtained by extending a urethane prepolymer having an isocyanate group at both molecular ends obtained from diisocyanate and polyol with a diamine compound by a urea bond and then adding tetracarboxylic dianhydride to a urea bond part. It is a block copolymer into which an imide unit is introduced. The imide-modified elastomer (I) can be produced, for example, through reaction process formulas (A) to (C) as shown 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 diisocyanate (a) and the polyol (b). The imide-modified elastomer (I) contains this urethane prepolymer (c) as an elastomer component.

  Examples of the 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), pitorylene diisocyanate (TODI), naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HMDI), isophorone Isocyanate (IPDI), lysine diisocyanate methyl ester (LDI), metaxylylene diisocyanate (MXDI), 2,2,4-trimethylhexamethylene diisocyanate (TMDI), 2,4,4-trimethylhexamethylene 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 polyol; polyester polyols such as adipate-based polyol (condensed polyester polyol) and polycaprolactone-based polyol; Polycarbonate polyols; polybutadiene polyols; acrylic polyols and the like may be mentioned, and these may be used alone or in combination of two or more.

  In particular, the polyol (b) is preferably at least one selected from polyester polyols and polycarbonate polyols. Thereby, since at least one of the polyester structural unit and the polycarbonate structural unit excellent in heat resistance and durability is introduced into the main chain, the heat resistance and durability of the imide-modified elastomer (I) can be improved.

  Examples of the polyester polyol include polyester polyols obtained by condensation polymerization of polycarboxylic acid and polyol, 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 diol, β-methyl-δ- Examples include polyols obtained by ring-opening valerolactone with ethylene glycol, and these may be used alone or in combination of two or more.

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

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

  Examples of the polycarbonate polyol include a polycarbonate polyol obtained by condensation polymerization of a polyol (polyhydric alcohol) and phosgene, chloroformate ester, dialkyl carbonate, diallyl carbonate, alkylene carbonate, and the like. Examples include 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 1,5-pentanediol, etc. Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate. Is mentioned. Specific examples of the polycarbonate polyol include polycarbonate diols such as polytetramethylene carbonate diol and polyhexamethylene carbonate diol.

  Moreover, as said polycarbonate polyol, the polycarbonate diol (henceforth "polycarbonate diol (ii)") represented by said Formula (ii) is mentioned. When the polycarbonate diol (ii) is used as the polyol (b), high releasability, heat resistance and durability can be obtained. The polycarbonate diol (ii) is a diol component obtained by copolymerizing two components through a carbonate bond, and is a so-called copolymerized polycarbonate diol. Since the polycarbonate diol (ii) is liquid at room temperature (23 ° C.), it is excellent in handleability. In the formula (ii), y represents an integer of 5 or 6. Z represents an integer of 1 to 76, preferably 6 to 15.

  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.

  In the reaction, the diisocyanate (a) and the polyol (b) exemplified above are mixed at a predetermined ratio, and then in an inert gas atmosphere such as argon gas at room temperature (23 ° C.) for about 1 to 5 hours. What is necessary is just to make it react. The mixing ratio (mole) of diisocyanate (a) and polyol (b) is preferably in the range of diisocyanate (a): polyol (b) = 1.01: 1 to 2: 1.

  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，ｍは、前記と同じである。］ [Reaction process formula (B)]

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

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

  Examples of the 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, abbreviated as 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, the urethane prepolymer (c) and the diamine compound (d) exemplified above are mixed in an equimolar amount, preferably an NCO / NH ₂ ratio of about 1.0, and then inert such as argon gas. A solution polymerization reaction or a bulk polymerization reaction may be performed in a gas atmosphere at room temperature to 100 ° C., preferably 50 to 100 ° C., for about 2 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、Ｒ₁〜Ｒ₄，ｎ，ｍは、前記と同じである。］ [Reaction process formula (C)]

[Wherein, R _{1 to} R ₄ , n, m are the same as described above. ]

(Synthesis of imide-modified elastomer (I))
Using the polyurethane-urea compound (e) obtained above, an imide-modified elastomer (I) is synthesized according to the reaction process formula (C). That is, an imide unit is introduced into the urea bond portion with tetracarboxylic dianhydride (f) to obtain an imide-modified elastomer (I) which is a block copolymer.

  Examples of the tetracarboxylic dianhydride (f) 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, Carbon number of 4 ′-(2,2-hexafluoroisopropylidene) diphthalic dianhydride (6FDA), m (p) -terphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, etc. 6-18 aromatic tetracarboxylic dianhydrides; cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1-carboxymethyl-2,3,5-cyclopentanetricarboxylic acid- , 6: 3,5 dianhydride alicyclic tetracarboxylic dianhydride of 4-6 carbon atoms such as, and the like. These may be used alone or in combination.

  The reaction is an imidization reaction between the polyurethane-urea compound (e) and the tetracarboxylic dianhydride (f). The imidation reaction may be performed in a solvent or without a solvent. When the imidization reaction is performed in a solvent, first, the polyurethane-urea compound (e) and the tetracarboxylic dianhydride (f) exemplified above are added to the solvent at a predetermined ratio, and an argon gas or the like is added. Under an inert gas atmosphere, a polyurethane amic acid represented by the following formula (g) is reacted at 100 to 300 ° C., preferably 135 to 200 ° C., more preferably 150 to 170 ° C. for about 1 to 10 hours. Hereinafter, a solution containing “PUA”) is obtained.

［式中、Ｒ₁〜Ｒ₄，ｎ，ｍは、前記と同じである。］

[Wherein, R _{1 to} R ₄ , n, m are the same as described above. ]

  The mixture of the polyurethane-urea compound (e) and the tetracarboxylic dianhydride (f) is obtained by mixing the diamine compound (d) and the tetracarboxylic dianhydride (f) used in the synthesis of the polyurethane-urea compound (e). It is preferable that the mixing ratio (mol) of diamine compound (d): tetracarboxylic dianhydride (f) is mixed at a ratio in the range of 1: 2 to 1: 2.02. 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 as those exemplified as the solvent that can be used in the solution polymerization reaction of the reaction process formula (B). In the reaction process formula (B), when the polyurethane-urea compound (e) is obtained by a solution polymerization reaction, an imidization reaction may be performed in the solvent.

  Next, the PUA solution obtained above is heat-treated at 100 to 200 ° C. for 60 to 120 minutes, and further subjected to heat treatment (dehydration condensation reaction) to obtain an imide-modified elastomer (I). The heat treatment is a condition in which PUA is not thermally decomposed, and is preferably performed at 150 to 250 ° C. for 90 to 150 minutes.

  On the other hand, when the imidization reaction is carried out in the absence of a solvent, since it can be carried out in an extruder equipped with a heating means having an exhaust system in addition to a normal stirred tank reactor, the resulting imide-modified elastomer ( I) can be extruded and formed into a film or sheet as it is.

  The weight average molecular weight of the imide-modified elastomer (I) is 10,000 to 1,000,000, preferably 15,000 to 150,000, more preferably 20,000 to 100,000. If the molecular weight is too small, heat resistance and durability may be lowered, and if it is too large, moldability may be lowered. The weight average molecular weight is a value derived from a value obtained by measuring the PUA solution by GPC and converting the obtained measurement value into polystyrene. The reason why the PUA solution, not the imide-modified elastomer (I), is measured by GPC is that the imide-modified elastomer (I) is insoluble in the GPC measurement solvent.

  The elastic modulus of the imide-modified elastomer (I) can be arbitrarily adjusted by adjusting the imide fraction, that is, the ratio of the imide component in the imide-modified elastomer (I). 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 a value calculated from the charged amounts of raw materials, that is, diisocyanate (a), polyol (b), diamine compound (d) and tetracarboxylic dianhydride (f). It is a value calculated from α).

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

  The usage form of the release material comprising the imide-modified elastomer (I) is not particularly limited, and for example, it can be used in the form of a film or sheet. Further, if the PUA solution is centrifugally molded, it can be used in the form of a seamless belt. The PUA solution can be applied directly to the molded body, or it can be sprayed and then used in the form of a film after heat treatment.

  The mold release material according to the present embodiment can be used for manufacturing solar cell modules, for example, for heat sealing applications, non-adhesive applications, heat treatment applications, plastic processing applications, high-frequency drying applications, and the like. In addition, the release material according to the present embodiment is not limited to the applications exemplified above, and can be suitably used in fields where not only release properties but also heat resistance and durability are required.

  Next, another embodiment according to the release material of the present invention will be described. The release material according to the present embodiment is obtained by holding the imide-modified elastomer (I) on a heat resistant fiber. Thereby, the tensile strength of a mold release material can be improved.

  The heat resistant fiber means a fiber having heat resistance. Examples of the heat resistant fiber include inorganic fibers such as glass fiber and alumina fiber; organic fibers such as aramid fiber and wholly aromatic polyester fiber, and the like, and glass fiber is particularly preferable. The shape of the heat-resistant fiber, such as mass, thickness, and woven density, is not particularly limited, and those having a desired shape can be employed depending on the application.

  As a method for holding the imide-modified elastomer (I) on the heat-resistant fiber, a dipping method in which the heat-resistant fiber is immersed in the PUA solution and pulled up and then heat-treated is preferable. In place of the dip method, the PUA solution may be applied to the heat-resistant fiber or may be subjected to heat treatment after spraying. Other configurations are the same as those of the release material according to the above-described embodiment.

  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.

  Four types of release materials composed of an imide-modified elastomer represented by the general formula (I) were synthesized based on the reaction process formulas (A) to (C). The materials used in each synthesis example are as follows.

Diisocyanate (a): 4,4′-diphenylmethane diisocyanate manufactured by Nippon Polyurethane Industry Co., Ltd.
Polyol (b): polyester diol (i) or polycarbonate diol (ii).
Polyester diol (i): trade name “P1050” manufactured by Kuraray Co., Ltd .; weight average molecular weight 1,000; in formula (i), x represents an integer of 3-4.
Polycarbonate diol (ii): “Duranol T5652” manufactured by Asahi Kasei Chemicals Corporation; weight average molecular weight 2,000; in the formula (ii), y is 5 or 6, and z is an integer of 14-15.
-Diamine compound (d): 4,4'-diaminodiphenylmethane.
Tetracarboxylic dianhydride (f): pyromellitic anhydride.
Heat-resistant fiber: Glass fiber “H201 M 104F” manufactured by Unitika Ltd .; mass 210 g / m ² , thickness 0.18 mm, plain weave, weave density (length × width) 42 × 32/25 mm.

<Synthesis Example 1: Release Material A>
(Synthesis of urethane prepolymer (c1))
First, diisocyanate (a) was distilled under reduced pressure, and polyol (b) was dried under reduced pressure under conditions of 80 ° C., 2-3 mmHg, 24 hours. Polyester diol (i) was used as the polyol (b).

  Next, 30.4 g of diisocyanate (a) and 69.6 g of polyol (b) were added to a 500 ml four-necked separable flask equipped with a stirrer and a gas introduction tube, respectively, at 80 ° C. under an argon atmosphere. The mixture was stirred for 2 hours to obtain a urethane prepolymer (c1) having an isocyanate group at both molecular ends. As a result of measuring this urethane prepolymer (c1) by GPC, the weight average molecular weight was 8,000 in terms of polystyrene.

(Synthesis of polyurethane-urea compound (e1))
10 g of the urethane prepolymer (c1) obtained above was dissolved in 60 ml of dehydrated N-methyl-2-pyrrolidone (NMP) and 1.034 g of the diamine compound (d) was dissolved in 20 ml of dehydrated NMP. Were added to a 500 ml four-necked separable flask equipped with a stirrer and a gas introduction tube, respectively, and stirred at room temperature (23 ° C.) for 24 hours under an argon atmosphere to obtain a polyurethane-urea compound (e1) solution. Obtained.

(Synthesis of imide-modified elastomer (1))
2.276 g of tetracarboxylic dianhydride (f) was added to the polyurethane-urea compound (e1) solution obtained above, and the mixture was stirred at 150 ° C. for 2 hours under an argon gas atmosphere to obtain a PUA solution. . Next, the PUA solution was poured into a centrifugal molding machine and subjected to centrifugal molding at 150 ° C. for 300 rpm for 1 hour to obtain a PUA sheet. This PUA sheet is heated at 200 ° C. for 2 hours in a vacuum desiccator (dehydration condensation reaction), and consists of an imide-modified elastomer (1) in which n is 1 to 100 and m is 2 to 100 in the general formula (I). A sheet-shaped release material A having a thickness of 0.1 mm was obtained.

The imide-modified elastomer (1) had an imide fraction of 35% by weight, an elastic modulus of 3.0 × 10 ⁸ Pa, and a weight average molecular weight of 40,000. The imide fraction was calculated from the formula (α). The elastic modulus was 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 ′ was measured. The weight average molecular weight was derived from a value obtained by measuring the PUA solution by GPC and converting the obtained measurement value into polystyrene.

As for the imide-modified elastomer (1), a result 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 were observed.

<Synthesis Example 2: Release material B>
A urethane prepolymer having a weight average molecular weight of 10,000 in the same manner as in Synthesis Example 1 except that 79.98 g of polycarbonate diol (ii) and 20.02 g of diisocyanate (a) were used as polyol (b). (C2) was obtained.

  Next, a polyurethane-urea compound (e2) solution was obtained in the same manner as in Synthesis Example 1 except that the urethane prepolymer (c2) obtained above was used, and PUA was obtained using this polyurethane-urea compound (e2). A sheet is obtained, and the PUA sheet is heat-treated to form a 0.1 mm thick sheet-shaped release composed of an imide-modified elastomer (2) in which n is 1 to 100 and m is 2 to 100 in the general formula (I). Mold material B was obtained.

The imide-modified elastomer (2) had an imide fraction of 28% by weight, an elastic modulus of 1 × 10 ⁸ Pa, and a weight average molecular weight of 44,000. As for the imide-modified elastomer (2), a result 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 were observed.

<Synthesis Example 3: Release Material C>
First, a PUA solution was obtained in the same manner as in Synthesis Example 1. Next, 10 g of heat-resistant fiber (glass fiber) was immersed in the PUA solution, pulled up, and then heat treated in the same manner as in Synthesis Example 1. As a result, a sheet-like release material C having a thickness of 0.4 mm made of the imide-modified elastomer (1) held on the glass fiber was obtained.

<Synthesis Example 4: Release Material D>
First, a PUA solution was obtained in the same manner as in Synthesis Example 2. Next, 10 g of heat-resistant fiber (glass fiber) was immersed in the PUA solution, pulled up, and then heat treated in the same manner as in Synthesis Example 1. As a result, a sheet-like release material D having a thickness of 0.4 mm made of the imide-modified elastomer (2) held on the glass fiber was obtained.

[Examples 1 and 2]
The release materials A and B obtained in Synthesis Examples 1 and 2 were evaluated for 180 ° peel strength, Taber abrasion amount, tensile strength, and rate of decrease in thermal aging elongation. Each evaluation method is shown below, and the results are shown in Table 1.

(180 ° peel strength)
First, release materials A and B were pressed and fused to a sheet of 0.15 mm thick made of ethylene vinyl acetate resin while applying a temperature of 180 ° C. Next, the release materials A and B were peeled 180 ° from the sheet at a rate of 300 mm / min using a load cell at an ambient temperature of 23 ° C., and 180 ° peel strength (based on JIS Z0237) was measured. Evaluation criteria were set as follows.
○: ≦ 5 × 10 ⁻³ N / mm
×:> 5 × 10 ⁻³ N / mm

(Taber wear)
The amount of wear of the release materials A and B was measured when the wear wheel H-18 of a Taber abrasion tester “5150 ABRASER” manufactured by Yasuda Seiki Seisakusho was rotated 1000 times. Evaluation criteria were set as follows.
○: ≦ 20mg
×:> 20 mg

(Tensile strength)
The release materials A and B were punched with a No. 3 dumbbell, and the tensile strength was measured in accordance with JIS K6251 under the conditions of 20 mm between marked lines and 500 mm / min. Evaluation criteria were set as follows.
○: ≧ 40 MPa
×: <40 MPa

(Heat aging elongation decrease rate)
The release materials A and B were punched with a No. 3 dumbbell, and after heat aging in a gear oven at 150 ° C. for 72 hours, the tensile strength was measured according to JIS K6257 under the same conditions as described above. Then, the tensile strength before and after heat aging was applied to the formula: [(tensile strength after heat aging / tensile strength before heat aging) −1] × 100 to calculate the elongation reduction rate (%). Evaluation criteria were set as follows.
○: ≤ 30%
×:> 30%

[Comparative Example 1]
A polyamic acid solution (trade name “U varnish A” manufactured by Ube Industries, Ltd.) was poured into a centrifugal molding machine, formed into a sheet by centrifugation at 1,000 ° C. for 1 hour at 150 ° C., and then placed in a vacuum desiccator. Heat treatment (dehydration condensation reaction) at 2 ° C. for 2 hours was performed to obtain a sheet-like release material a having a thickness of 0.1 mm made of polyimide resin. With respect to the obtained release material a, 180 ° peel strength, Taber abrasion amount, tensile strength, and rate of decrease in thermal aging elongation were evaluated in the same manner as in Examples 1 and 2. The results are shown in Table 1.

[Comparative Example 2]
A release material b was obtained by forming an ester-based polyurethane (trade name “C85A” manufactured by BASF Corporation) into a sheet having a thickness of 1 mm. With respect to the obtained release material b, the 180 ° peel strength, the Taber abrasion amount, the tensile strength, and the rate of decrease in thermal aging elongation were evaluated in the same manner as in Examples 1 and 2. The results are shown in Table 1.

[Comparative Example 3]
As a sheet-like release material c having a thickness of 0.05 mm made of polytetrafluoroethylene [Teflon (registered trademark)], “Skived Tape” manufactured by Chuko Kasei Kogyo Co., Ltd. was used. With respect to this release material c, 180 ° peel strength, Taber abrasion amount, tensile strength, and rate of decrease in thermal aging elongation were evaluated in the same manner as in Examples 1 and 2. The results are shown in Table 1.

  As is clear from Table 1, Examples 1 and 2 made of the imide-modified elastomer represented by the general formula (I) have excellent releasability because the 180 ° peel strength is small. Recognize. Moreover, since the amount of Taber abrasion is small and the rate of decrease in thermal aging elongation is small, it can be seen that the durability and heat resistance are also excellent. Furthermore, it turns out that it is excellent also in tensile strength.

  On the other hand, Comparative Example 1 made of polyimide resin showed excellent results with a 180 ° peel strength (releasability), although it was excellent in Taber abrasion (durability) and thermal aging elongation reduction rate (heat resistance). . Although the comparative example 2 which consists of polyurethane was excellent in durability, the result inferior to mold release property and heat resistance was shown. In particular, the heat resistance could not be evaluated because the sample was deformed during the evaluation. Although the comparative example 3 which consists of polytetrafluoroethylene was excellent in heat resistance, the result inferior to mold release property and durability was shown.

[Examples 3 and 4]
With respect to the release materials C and D obtained in Synthesis Examples 3 and 4, 180 ° peel strength, Taber abrasion amount and tensile strength were evaluated in the same manner as in Examples 1 and 2. The results are shown in Table 2.

[Comparative Example 4]
“FGF-500-10” manufactured by Chuko Kasei Kogyo Co., Ltd. was used as a sheet-like release material d having a thickness of 0.24 mm made of polytetrafluoroethylene held on glass fibers. With respect to this release material d, 180 ° peel strength, Taber abrasion amount and tensile strength were evaluated in the same manner as in Examples 1 and 2. The results are shown in Table 2.

  As can be seen from Table 2, Examples 3 and 4 made of the imide-modified elastomer represented by the general formula (I) held on the glass fiber are excellent in releasability. Moreover, it turns out that it is excellent also in durability. Furthermore, it turns out that the tensile strength is improving rather than Example 1,2. On the other hand, the comparative example 4 which consists of polytetrafluoroethylene hold | maintained at the glass fiber showed the result inferior to mold release property and durability.

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 (7)

A release material comprising an imide-modified elastomer represented by the following general formula (I).

[Wherein, R ₁ 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 ₄ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. m shows the integer of 2-100. ]   The imide-modified elastomer is obtained by extending a urethane prepolymer having an isocyanate group at both molecular ends obtained from diisocyanate and polyol with a diamine compound by a urea bond, and an imide unit at a urea bond with tetracarboxylic dianhydride. The release material according to claim 1, which is a block copolymer into which is introduced.   The mold release material according to claim 2, wherein the polyol is at least one selected from polyester polyol and polycarbonate polyol. The mold release material according to claim 3, wherein the polyester polyol is a polyester diol represented by the following formula (i).

[Wherein, x represents an integer of 1 to 37. ] The mold release material according to claim 3 or 4, wherein the polycarbonate polyol is a polycarbonate diol represented by the following formula (ii).

[Wherein y represents an integer of 5 or 6. z shows the integer of 1-76. ] A mold release material comprising an imide-modified elastomer represented by the following general formula (I), which is held in a heat-resistant fiber.

[Wherein, R ₁ 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 ₄ represents a tetravalent organic group containing 4 or more carbon atoms. n shows the integer of 1-100. m shows the integer of 2-100. ]   The mold release material according to claim 6, wherein the heat-resistant fiber is a glass fiber.

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