Polyester resin composition, adhesive and laminate

Abstract

A polyester resin composition comprising 100 parts by mass of a polyester resin (A) and 0.05 to 10 parts by mass of a nitrogen-containing heterocyclic compound (B), wherein the polyester resin (A) has a glass transition temperature of -20 to 30°C, and the nitrogen-containing heterocyclic compound (B) is one or more compounds selected from the group consisting of benzotriazole compounds, mercaptobenzothiazole compounds, and triazine thiol compounds.

Description

[Technical field]

[0001] The present invention relates to a polyester resin composition which has excellent adhesion to polyester films and metals and can be suitably used as an adhesive for flexible flat cables. [Background technology]

[0002] To date, flexible flat cables (hereinafter sometimes referred to as FFCs), which consist of a flat conductor sandwiched between electrically insulating synthetic resin films, have been widely used for the internal wiring of electronic devices, etc., in order to make wiring work more efficient.

[0003] Polyester film has traditionally been used as the electrically insulating synthetic resin film that makes up FFCs, and polyester-based resins have been used as adhesives to bond this electrically insulating synthetic resin film to conductors because of their insulation properties, durability, and adhesion to the electrically insulating synthetic resin film that serves as the base material.

[0004] In addition, FFCs, which are thin, light, and less prone to incorrect wiring, are being increasingly used in the automotive field for a variety of wiring and components because they enable the modularization of parts and expansion of interior space. They are increasingly being used for fixed wiring, such as inside cockpits and roofs, as well as for movable wiring, such as in steering wheels and rearview monitors.

[0005] Furthermore, with the increasing demand for lighter weight and higher performance, FFCs are expected to be used in engine rooms, which are subject to harsher operating environments. Parts used in engine rooms must be heat-resistant, and must also be saltwater-resistant to withstand water that may get into the engine room and salt that may get in when driving near the coast. Adhesives for FFCs must also be saltwater-resistant, so that their adhesive strength does not decrease even when exposed to water or salt.

[0006] For the conductors that make up FFCs, copper wires with a surface-plated layer made of metals such as tin, nickel, and gold are widely used to improve corrosion resistance, but to reduce manufacturing costs, there is a demand for the use of non-plated copper wires that do not have a plating layer. However, non-plated copper wires have poor corrosion resistance and are prone to surface oxidation due to the effects of water and salt, and as surface oxidation progresses, the adhesive strength with adhesives can be significantly reduced. Therefore, there has been a demand for adhesives for FFCs that have excellent adhesion to non-plated copper wires and resistance to saltwater.

[0007] However, no adhesive made of a polyester resin composition having such excellent heat resistance and salt water resistance has yet been proposed.

[0008] The adhesive compositions containing a polyester resin and a curing agent disclosed in WO 2011 / 129278 and JP 2008-150443 A are intended to improve adhesive strength, but do not take saltwater resistance into consideration. As a result, the adhesive strength is significantly reduced after salt water spray treatment, and the saltwater resistance is insufficient. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made to solve the above problems, and it is an object of the present invention to provide a polyester resin composition which has excellent adhesion to polyester films and non-plated copper in particular, can be suitably used as an adhesive for FFCs used in the internal wiring of electronic devices, has high adhesive strength in high-temperature environments, has excellent heat resistance, shows little decrease in adhesive strength after salt spray treatment, and has excellent saltwater resistance. [Means for solving the problem]

[0010] The present inventors have conducted intensive research to solve the above problems, and as a result, have arrived at the present invention. 6 ) is the gist of this paper. (1) 100 parts by mass of a polyester resin (A), 0.05 to 10 parts by mass of a nitrogen-containing heterocyclic compound (B), and 0.1 to 5 parts by mass of a silane coupling agent (C). 1 to 5 parts by mass of an isocyanate compound (D); Contains The polyester resin (A) has a glass transition temperature of -20 to 30°C. the nitrogen-containing heterocyclic compound (B) is one or more compounds selected from the group consisting of benzotriazole compounds, mercaptobenzothiazole compounds, and triazinethiol compounds; The silane coupling agent (C) has an amino group as a terminal group. death, The isocyanate compound (D) is an isocyanurate of hexamethylene diisocyanate. A polyester resin composition comprising: (2) The polyester resin composition according to (1), wherein the benzotriazole compound is a compound represented by the following general formula (1): [ka] [In formula (1), R 1 represents a hydrogen atom, a substituted alkyl group, or an alkali metal; R 2 represents a hydrogen atom, a methyl group, or a carboxy group. ] (3 ) The polyester resin (A) contains 60 to 90 mol % of terephthalic acid and 10 to 40 mol % of an aliphatic dicarboxylic acid having 4 to 15 carbon atoms as acid components, and contains 25 to 55 mol % of 1,4-cyclohexanedimethanol as a glycol component (1). Or (2) The polyester resin composition described above. ( 4 ) The polyester resin (A) has a melting point of 110 to 150°C. 3 2. The polyester resin composition according to claim 1 , ( 5 ) Above (1)~( 4 2. An adhesive comprising the polyester resin composition according to claim 1 . ( 6 ) Above (1)~( 42. A laminate comprising a layer containing the polyester resin composition according to claim 1. Effect of the Invention

[0011] The polyester resin composition of the present invention contains a specific amount of a nitrogen-containing heterocyclic compound in a specific polyester resin, and therefore has excellent adhesion, particularly to polyester films and non-plated copper, and after bonding, has high adhesion strength in a high-temperature atmosphere, excellent heat resistance, and shows little decrease in adhesion strength even when subjected to a salt spray treatment, and has excellent adhesion resistance to salt water. Therefore, products such as FFCs that use the polyester resin composition of the present invention as an adhesive layer have excellent heat resistance and salt water resistance, and are less likely to suffer from problems such as peeling and poor contact even when used in harsh environments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below. The polyester resin composition of the present invention contains a polyester resin (A) and a nitrogen-containing heterocyclic compound (B).

[0013] First, the polyester resin (A) in the present invention will be described. The polyester resin (A) must have a glass transition temperature of -20 to 30°C, and preferably -10 to 20°C. If the polyester resin (A) has a glass transition temperature below -20°C, the elastic modulus at room temperature decreases, and the polyester resin composition lacks adhesive strength to metal. On the other hand, if the polyester resin (A) has a glass transition temperature above 30°C, the elastic modulus at around room temperature increases, and the resin itself becomes too hard, so that the polyester resin composition does not exhibit adhesiveness to the adherend.

[0014] The melting point of the polyester resin (A) is not particularly limited as long as it is within a range that does not impair the effects of the present invention, but is preferably 110 to 150° C., and more preferably 115 to 145° C. If the melting point of the polyester resin (A) is less than 110° C., the polyester resin composition may have a reduced adhesive strength in a high-temperature atmosphere. On the other hand, if the melting point of the polyester resin (A) is more than 150° C., the polyester resin composition may have a reduced fluidity during lamination, resulting in a reduced adhesive strength.

[0015] In order to set the glass transition temperature and melting point of the polyester resin (A) within the above ranges, it is preferable that the polyester resin (A) has the following composition. First, when the total amount of the glycol components of the polyester resin (A) is taken as 100 mol%, the glycol components preferably contain 25 to 55 mol% of 1,4-cyclohexanedimethanol, and more preferably 35 to 45 mol% of 1,4-cyclohexanedimethanol. If the content of 1,4-cyclohexanedimethanol is less than 25 mol%, the polyester resin (A) may have a lower melting point. On the other hand, if the content of 1,4-cyclohexanedimethanol is more than 55 mol%, the polyester resin (A) may have a higher melting point.

[0016] In addition, the acid component of the polyester resin (A) preferably contains 60 to 90 mol % of terephthalic acid, more preferably 65 to 85 mol %, when the total amount of the acid components is 100 mol %. If the content of terephthalic acid exceeds 90 mol %, the solubility of the polyester resin (A) may decrease. On the other hand, if the content of terephthalic acid is less than 60 mol %, the crystallinity of the polyester resin (A) may decrease, resulting in a decrease in the melting point. The acid component of the polyester resin (A) preferably contains 10 to 40 mol %, and more preferably 15 to 35 mol %, of an aliphatic dicarboxylic acid having 4 to 15 carbon atoms. If the content of the aliphatic dicarboxylic acid having 4 to 15 carbon atoms exceeds 40 mol %, the polyester resin (A) may have a low glass transition temperature. On the other hand, if the content of the aliphatic dicarboxylic acid having 4 to 15 carbon atoms is less than 10 mol %, the polyester resin (A) may have a high glass transition temperature.

[0017] In view of the above, in the present invention, it is preferable that the polyester resin (A) constituting the polyester resin composition contains 60 to 90 mol % of terephthalic acid and 10 to 40 mol % of an aliphatic dicarboxylic acid having 4 to 15 carbon atoms as acid components, and contains 25 to 55 mol % of 1,4-cyclohexanedimethanol as a glycol component.

[0018] Examples of glycol components other than 1,4-cyclohexanedimethanol in the polyester resin (A) include aliphatic glycols such as ethylene glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, and 1,6-hexanediol, polyalkylene glycols such as polyethylene glycol, triethylene glycol, and polytetramethylene glycol, and aromatic glycols such as hydroquinone, 4,4'-dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy)benzene, bisphenol A, 2,5-naphthalenediol, and glycols obtained by adding ethylene oxide to these glycols. Among these, ethylene glycol, 1,4-butanediol, triethylene glycol, and polytetramethylene glycol are preferred. Examples of polyhydric alcohols other than glycol include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, and hexanetriol.

[0019] In the polyester resin (A), examples of the aliphatic dicarboxylic acid having 4 to 15 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, etc., and among these, adipic acid and sebacic acid are preferred. The aliphatic dicarboxylic acid having 4 to 15 carbon atoms may be used alone or in combination of two or more of these.

[0020] Examples of acid components other than terephthalic acid and aliphatic dicarboxylic acids having 4 to 15 carbon atoms in the polyester resin (A) include aromatic dicarboxylic acids such as isophthalic acid, 5-(alkali metal)sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyldicarboxylic acid, or ester-forming derivatives thereof, and unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, and itaconic acid, or ester-forming derivatives thereof. Examples of polyvalent carboxylic acids other than dicarboxylic acids include butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3',4'-biphenyltetracarboxylic acid, and ester-forming derivatives thereof.

[0021] In the present invention, the polyester resin (A) may contain an antioxidant to the extent that the characteristics of the polyester resin (A) are not impaired. For example, examples of hindered phenol-based antioxidants include 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,1,3-tri(4-hydroxy-2-methyl-5-t-butylphenyl)butane, 1,1-bis(3-t-butyl-6-methyl-4-hydroxyphenyl)butane, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid, pentaerythrityltetrakis(3,5-di-t-butyl-4 -hydroxyphenyl)propionate, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-benzenepropanoic acid, 3,9-bis[1,1-dimethyl-2-[(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)benzene, and the like. Phosphorus antioxidants include 3,9-bis(p-nonylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tri(mononylphenyl)phosphite, triphenoxyphosphine, isodecylphosphite, isodecylphenylphosphite, diphenyl 2-ethylhexylphosphite, dinonylphenylbis(nonyl tris(2,4-di-t-butylphenyl) phosphate, pentaerythritol bis(2,4-di-t-butylphenyl phosphite), 2,2'-methylene bis(4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, and the like.Examples of thioether antioxidants include 4,4'-thiobis[2-t-butyl-5-methylphenol]bis[3-(dodecylthio)propionate], thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene]bis[3-(tetradecylthio)-propionate], pentaerythritol tetrakis(3-n-dodecylthiopropionate), and bis(tridecyl)thiodipropionate. The antioxidants may be used alone or in combination of two or more.

[0022] The polyester resin (A) in the present invention can be synthesized by a conventionally known polyester synthesis method. For example, the above-mentioned acid component and glycol component are used as raw materials, and an esterification or transesterification reaction is carried out at a temperature of 220 to 280°C by a conventional method, followed by adding a polycondensation catalyst and carrying out a polycondensation reaction at a temperature of 230 to 280°C, preferably 240 to 260°C, under a reduced pressure of 5 hPa or less. Depending on the purpose or use, the polyester resin can also be obtained by adding an acid component or a glycol component to the polymer obtained by the polycondensation reaction and carrying out a depolymerization reaction at a temperature of 220 to 280°C. In addition, the flame retardant and filler described later can also be added during the polycondensation reaction.

[0023] Next, the nitrogen-containing heterocyclic compound (B) will be described. The nitrogen-containing heterocyclic compound (B) constituting the polyester resin composition of the present invention is required to be a benzotriazole compound, a mercaptobenzothiazole compound, or a triazinethiol compound, since the adhesion to non-plated copper is not reduced even after salt spray treatment and the compound has the effect of improving salt water resistance. These compounds can be used alone or in combination of two or more kinds.

[0024] The benzotriazole compound is not particularly limited as long as it has a benzotriazole skeleton, but is preferably a compound represented by the following general formula (1). [ka] [In formula (1), R1 represents a hydrogen atom, a substituted alkyl group, or an alkali metal; R 2 represents a hydrogen atom, a methyl group, or a carboxy group. Specific examples of the benzotriazole compound represented by the general formula (1) include 1,2,3-benzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole, carboxybenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol, 5-methylbenzotriazole, 1,2,3-benzotriazole sodium salt, etc. Among them, 1,2,3-benzotriazole or carboxybenzotriazole is preferred from the viewpoint of easy availability. Benzotriazole compounds other than the compound represented by the general formula (1) include 1-hydroxybenzotriazole and the like. Commercially available benzotriazole compounds include BT-120, BT-LX, CBT-1, TT-LX, TT-LYK, 5M-BTA, and JCL-400 manufactured by Johoku Chemical Co., Ltd., and BT, BT-R, and BT-F manufactured by Kawaguchi Chemical Industry Co., Ltd.

[0025] The mercaptobenzothiazole compound is not particularly limited as long as it has a mercaptobenzothiazole skeleton, and examples thereof include 2-mercaptobenzothiazole, (2-benzothiazylthio)acetic acid, 3-(2-benzothiazylthio)propionic acid, etc. Among these, 2-mercaptobenzothiazole is preferred because of its easy availability. Commercially available mercaptobenzothiazole compounds include Sunmeler M, Sunmeler MG, Sunbit ABT, and Sunbit PBT manufactured by Sanshin Chemical Industry Co., Ltd., and ACCEL M manufactured by Kawaguchi Chemical Industry Co., Ltd.

[0026] The triazinethiol compound is not particularly limited as long as it has a triazinethiol skeleton, and examples thereof include 2,4,6-trimercapto-s-triazine, 2-dibutylamino-4,6-dimercapto-s-triazine, 2,4,6-trimercapto-s-triazine monosodium salt, etc. Among them, 2-di-n-butylamino-4,6-dimercapto-s-triazine is preferred because of its easy availability. Commercially available triazine thiol compounds include Jisnet F (TTCA), Jisnet DB, and Santhiol N-1 manufactured by Sankyo Kasei Co., Ltd., and ACTOR TSH and ACTOR BSH manufactured by Kawaguchi Chemical Industry Co., Ltd.

[0027] Among the nitrogen-containing heterocyclic compounds (B), it is preferable to use benzotriazole compounds from the viewpoint of salt water resistance. In other words, when a benzotriazole compound is used, the polyester resin composition has excellent adhesion to polyester films and non-plated copper, and even if a salt water spray treatment is performed after adhesion, the decrease in adhesion strength is small, and the adhesion shows excellent salt water resistance.

[0028] The content of the nitrogen-containing heterocyclic compound (B) is required to be 0.05 to 10 parts by mass, preferably 0.1 to 7 parts by mass, and more preferably 0.1 to 4 parts by mass, based on 100 parts by mass of the polyester resin (A). If the content of the nitrogen-containing heterocyclic compound (B) is more than 10 parts by mass based on 100 parts by mass of the polyester resin (A), the adhesive strength and heat resistance of the resin composition are reduced. If the content of the nitrogen-containing heterocyclic compound (B) is less than 0.05 parts by mass based on 100 parts by mass of the polyester resin (A), the salt water resistance of the resin composition is reduced, and the adhesiveness to the non-plated copper surface after salt water spray treatment is reduced.

[0029] The method for producing the polyester resin composition of the present invention is not particularly limited as long as the effects of the present invention are not impaired. For example, the polyester resin composition may be produced by adding the nitrogen-containing heterocyclic compound (B) together with the synthesis raw materials when synthesizing the polyester resin (A). Also, the polyester resin composition may be produced by adding both the polyester resin (A) and the nitrogen-containing heterocyclic compound (B) to an organic solvent when using the polyester resin composition as an adhesive.

[0030] Next, the silane coupling agent (C) will be described. The polyester resin composition of the present invention preferably contains a silane coupling agent (C). By containing the silane coupling agent (C), the polyester resin composition has improved adhesion to metal surfaces, and the adhesion to metals is improved, and the decrease in adhesion after salt spray treatment is small, resulting in excellent saltwater resistance. The content of the silane coupling agent (C) is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 3.5 parts by mass, relative to 100 parts by mass of the polyester resin (A). If the content of the silane coupling agent (C) is less than 0.1 parts by mass, the polyester resin composition may not have sufficient effect of improving adhesion to metals, and the adhesive strength after salt spray treatment may also be significantly reduced. On the other hand, if the content of the silane coupling agent (C) is more than 5 parts by mass, the polyester resin composition may not have sufficient effect of improving adhesion to metals, and the adhesive strength after salt spray treatment may also be significantly reduced. In addition, the stability of the solution of the polyester resin composition described later may be reduced.

[0031] The silane coupling agent (C) is preferably a hydrolyzable silane compound represented by the general formula: YR-Si-X3. Examples of Y include vinyl groups, epoxy groups, methacryl groups, isocyanate groups, hydroxy groups, amino groups, and mercapto groups. R is a linear or branched alkylene group. Examples of X include alkoxy groups such as methoxy groups or ethoxy groups, chloro groups, acetoxy groups, oxime groups, and isopropenoxy groups. Multiple Xs may be the same or different from each other. In terms of being able to impart excellent saltwater resistance to the polyester resin composition, Y is preferably an epoxy group, an isocyanate group, or an amino group, and among them, an amino group, which has a high effect of improving saltwater resistance, is more preferable.

[0032] Specific examples of the silane coupling agent (C) include vinyltriethoxysilane, vinyltrimethoxysilane, γ-(methacryloyloxypropyl)trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, and N-β(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane. Commercially available silane coupling agents (C) include, for example, "KBE-903" (3-aminopropyltriethoxysilane), "KBM-403" (3-glycidoxypropyltrimethoxysilane), and "KBE-9007" (3-isocyanatepropyltriethoxysilane), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0033] Next, the isocyanate compound (D) will be described. The polyester resin composition of the present invention preferably contains an isocyanate compound (D), and the content thereof is preferably 1 to 5 parts by mass, and more preferably 1.5 to 3.5 parts by mass, per 100 parts by mass of the polyester resin (A). If the content of the isocyanate compound (D) is less than 1 part by mass, the polyester resin composition will not be sufficiently cured, and the polyester resin composition may have poor adhesion to polyester films and metals and may have poor heat resistance. On the other hand, if the content of the isocyanate compound (D) is more than 5 parts by mass, the polyester resin composition may gel and have poor flowability, which may result in poor workability during adhesion and poor adhesion.

[0034] In the present invention, the isocyanate compound (D) has two or more isocyanate groups in the molecule, and among these, from the viewpoint of heat resistance, those having three or more isocyanate groups are preferred. Specific examples of the isocyanate compound (D) include a single isocyanate compound selected from 2,4- or 2,6-tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isopropylidenedicyclohexyl-4,4'-diisocyanate, etc., or an adduct, isocyanurate, or biuret of the above isocyanate compound selected from one or more of them. Among them, an isocyanurate having two or more isocyanate groups in the molecule, or a polyisocyanate having an aromatic ring is preferred.

[0035] A commercially available product of the isocyanate compound (D), which is an isocyanurate having two or more isocyanate groups in the molecule, is preferably "TPA-100" (an isocyanurate of hexamethylene diisocyanate) manufactured by Asahi Kasei Corporation, and a commercially available product of the isocyanate compound (C), which is a polyisocyanate having an aromatic ring, is preferably Desmodur RFE (tris(phenylisocyanate)thiophosphate) manufactured by Covestro.

[0036] The polyester resin composition of the present invention may contain a flame retardant as long as the effect of the present invention is not impaired. The flame retardant is capable of imparting flame retardancy to the polyester resin composition, and is preferably a halogen-based flame retardant, a nitrogen-based flame retardant, or a phosphorus-based flame retardant, and more preferably a halogen-based flame retardant.

[0037] Halogen-based flame retardants include hexabromocyclododecane, bis(dibromopropyl)tetrabromo-bisphenol A, bis(dibromopropyl)tetrabromo-bisphenol S, tris(dibromopropyl)isocyanurate, tris(tribromoneopentyl)phosphate, decabromodiphenylene oxide, brominated epoxy resins, bis(pentabromophenyl)ethane, tris(tribromophenoxy)triazine, ethylenebis(tetrabromophthalic)imide, and ethylenebispentabromophthalamide. Examples of suitable bromine compounds include bromine-based compounds such as brominated polyphenylene, polybromophenylindane, brominated polystyrene, TBBA polycarbonate, brominated polyphenylene oxide, and polypentabromobenzyl acrylate, and chlorine-based compounds such as tetrakis(2-chloroethyl)[2,2-bis(chloromethyl)-1,3-propanediyl]bisoxybisphosphonate, tris(1-methyl-2-chloroethyl)phosphate, and 2,2-bis(bromomethyl)-3-chloropropyl phosphate=bis[2-chloro-1-(chloroethyl)ethyl]phosphate.

[0038] Examples of the nitrogen-based flame retardant include aliphatic amine compounds, aromatic amine compounds, nitrogen-containing heterocyclic compounds such as triazine, melamine, benzoguanamine, methylguanamine, and cyanuric acid, cyanide compounds, aliphatic amides, aromatic amides, urea, and thiourea.

[0039] Examples of phosphorus-based flame retardants include polyphosphate-based, phosphinate-based, phosphoric acid ester-based, condensed phosphoric acid ester-based, and phosphazene-based flame retardants.

[0040] Furthermore, the polyester resin composition of the present invention may contain various additives such as a flame retardant aid for improving the flame retardant properties of the flame retardant, an antioxidant, a heat stabilizer, a pigment, and a filler, as long as the effects of the present invention are not impaired. Examples of the flame retardant aid include antimony trioxide, zinc stannate, and zinc borate. Examples of the antioxidant include the above-mentioned antioxidants, and hindered phenol compounds and phosphorus-based antioxidants are preferred. Examples of the heat stabilizer include phosphoric acid. Examples of the pigment include titanium oxide and carbon black. Examples of the filler include swelling clay minerals, silica, alumina, and glass beads. The additives may be used alone or in combination of two or more kinds.

[0041] The polyester resin composition of the present invention can be used as an adhesive. When used as an adhesive, the polyester resin composition of the present invention is preferably used after being dissolved in an organic solvent. The organic solvent is not particularly limited as long as it dissolves the polyester resin composition of the present invention, and examples thereof include aromatic solvents such as benzene, toluene, and xylene; chlorine-based solvents such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, and dichlorobenzene; ester-based solvents such as ethyl acetate, isophorone, and γ-butyrolactone; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as diethyl ether, ethyl cellosolve, butyl cellosolve, tetrahydrofuran, and 1,4-dioxane; alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol; aliphatic hydrocarbon-based solvents such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, n-octane, and nonane; and alicyclic hydrocarbon-based solvents such as cyclopentane and cyclohexane. Among these, methylene chloride, toluene, and methyl ethyl ketone are preferred. The organic solvents may be used alone or in combination.

[0042] In an adhesive in which a polyester resin composition is dissolved in an organic solvent, the content (solid content concentration) of the polyester resin composition is preferably 10 to 40 mass %, and more preferably 20 to 30 mass %. If the solid content concentration of the polyester resin composition is higher than 40 mass %, the adhesive may have reduced solution stability, while an adhesive with a solid content concentration of less than 10 mass % may require an increased coating amount or number of coatings to increase the thickness of the adhesive layer, resulting in poor work efficiency and reduced productivity.

[0043] Next, the laminate of the present invention will be described. The laminate of the present invention includes a layer (hereinafter, sometimes referred to as an adhesive layer) containing the polyester resin composition of the present invention. Among them, a laminate having a film layer / adhesive layer / metal layer laminated in this order is preferable, and a laminate having a film layer / adhesive layer / metal layer / adhesive layer / film layer laminated in this order is more preferable. The resin constituting the film layer is preferably a polyester such as polyethylene terephthalate (PET), polybutylene terephthalate, or polyethylene naphthalate, or may be a resin such as polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyarylate, polyamide, polyolefin, polyethersulfone, polysulfone, polystyrene, or methacrylic. The metal layer is preferably a layer in which a plurality of metal wires serving as conductors are arranged. Examples of metals constituting the conductors include copper, iron, aluminum, etc., and the conductors may be those plated with tin, zinc, etc., such as tinplate, or chemically treated products such as zinc phosphate and chromate.

[0044] A suitable method for producing the laminate of the present invention is to apply an adhesive containing the polyester resin composition of the present invention between a film layer and a metal layer, and then remove the solvent by a conventionally known method such as heat sealing, roll bonding, or hot pressing to bond the layers together. EXAMPLES

[0045] The present invention will now be described in detail with reference to examples. The measurement and evaluation methods for each characteristic value in the examples are as follows. (1) Composition of polyester resin Using a JEOL ECZ400R NMR instrument, 1 H-NMR was measured, and the ratio was determined from the integrated intensity ratio of the proton peaks of each copolymer component in the obtained chart.

[0046] (2) Inherent viscosity of polyester resin (ηinh) Using an Ubbelohde viscometer, the relative viscosity (ηrel) was measured at a concentration of 0.5 g / dl and a temperature of 25°C using a 50 / 50 (mass ratio) mixed solution of phenol and 1,1,2,2-tetrachloroethane as the solvent. The viscosity was calculated using the following formula and expressed in dl / g units. Inherent viscosity (ηinh) = ln(ηrel) / c ηrel: relative viscosity, c: concentration (g / dl)

[0047] (3) Acid value of polyester resin According to JIS K-0070, 0.5 g of the sample was dissolved in 25 ml of dioxane and titrated with 0.1 N-KOH using cresol red as an indicator. The titrated value was used to convert the amount of KOH consumed in neutralization into mg per 1 g of polyester resin to obtain the acid value.

[0048] (4) Hydroxyl value of polyester resin In accordance with JIS K-0070, 3 g of the sample was dissolved in 50 ml of pyridine under heating under reflux, and titrated with 0.5 N potassium hydroxide methanol solution using acetic anhydride as an acetylation solution and cresol red-thymol blue as an indicator. Using the titration value, the number of mg of KOH required to neutralize the acetic acid bonded to the hydroxyl group was converted to the number per gram of polyester resin, and the hydroxyl value was calculated.

[0049] (5) Glass transition temperature (Tg), melting point (Tm) The measurement was performed using a PerkinElmer differential scanning calorimeter (Diamond DSC) at a temperature rise rate of 20° C. / min.

[0050] (6) Solution stability The solution viscosity of the obtained adhesive was measured, and the solution stability of the polyester resin composition was evaluated based on the change over time. That is, the solution viscosity of the adhesive when left to stand for 1 hour after preparation (viscosity 1) and the solution viscosity when stored sealed at 23°C for 24 hours (viscosity 2) were measured using a B-type rotational viscometer, the ratio of viscosity 2 to viscosity 1 was calculated, and the solution stability was evaluated on a two-level scale according to the following criteria. ○: Viscosity 2 is 1.0 times or more and less than 1.3 times viscosity 1 ×: Viscosity 2 is 1.3 times or more than viscosity 1

[0051] (7) Adhesion to non-plated copper (at 23°C) The obtained adhesive was applied (coating thickness 100 μm) onto a PET film (thickness 30 μm), dried at 150°C for 3 minutes, and further treated at 50°C for 72 hours to produce Laminate 1 in which a 30 μm-thick adhesive layer made of a polyester resin composition was laminated onto the PET film. Five unplated copper wires (thickness 0.035 mm, width 0.3 mm, length 150 mm) were immersed in n-hexane for 10 minutes, then dried, and then immersed in 10% sulfuric acid for 15 minutes. They were then washed with distilled water and dried to produce surface-treated copper wires with the oxide coating removed. Five surface-treated copper wires were bonded to the adhesive layer surface of the obtained laminate 1 at intervals of 1 to 2 mm using a laminator (SA-1010 manufactured by Tester Sangyo Co., Ltd.) under conditions of a temperature of 180°C, a linear pressure of 40 N / cm, and a speed of 1.0 m / min, thereby obtaining laminate 2 laminated in the order of PET film / adhesive layer / surface-treated copper wire. The obtained laminate 2 was tested at a tensile speed of 300 mm / min in an atmosphere of 23°C using an Autograph AG-2 manufactured by Shimadzu Corporation to measure the 180° peel adhesion strength (peel adhesion strength 1), and the adhesion of the polyester resin composition to non-plated copper was evaluated according to the following criteria. S: 0.30N / 0.3mm≦Peel adhesion strength 1 A:0.25N / 0.3mm≦Peel adhesive force 1<0.30N / 0.3mm B:0.20N / 0.3mm≦Peel adhesive force 1<0.25N / 0.3mm C: Peeling adhesive force 1<0.20N / 0.3mm

[0052] (8) Adhesion to non-plated copper after salt spray treatment Laminate 2 produced in the same manner as in (7) above was subjected to a salt spray treatment for 72 hours in accordance with the method specified in JIS Z2371 and dried for 24 hours to obtain Laminate 3. The 180° peel adhesion strength (peel adhesion strength 2) of Laminate 3 was measured in the same manner as in (7), and the adhesion strength to non-plated copper after the salt spray treatment was evaluated according to the following criteria. S: 0.30N / 0.3mm≦Peel adhesion strength 2 A:0.25N / 0.3mm≦Peel adhesive force2<0.30N / 0.3mm B:0.20N / 0.3mm≦Peel adhesive force2<0.25N / 0.3mm C: Peeling adhesive force 2<0.20N / 0.3mm

[0053] (9) Peel adhesion retention rate after salt spray treatment The peel adhesion retention rate after the salt spray treatment was calculated using the following formula and evaluated according to the following criteria. Peel adhesion retention rate (%) = [(peel adhesion 2) / (peel adhesion 1)] x 100 S: 95% or less Retention rate of peel adhesion after salt spray treatment A: 75%≦Retention rate of peel adhesion after salt spray treatment<95% B: 60%≦Retention rate of peel adhesion after salt spray treatment<75% C: Peel adhesion retention after salt spray treatment <60%

[0054] (10) Adhesion to non-plated copper (at high temperatures (85°C)) For the laminate 2 produced in the same manner as in (7) above, a test was performed using an Autograph AG-2 manufactured by Shimadzu Corporation in an atmosphere of 85°C at a tensile speed of 300 mm / min to measure the 180° peel adhesion strength (peel adhesion strength 4). The adhesion of the polyester resin composition to non-plated copper was evaluated according to the following criteria. S:0.20N / 0.3mm≦Peel adhesive strength 4 A:0.15N / 0.3mm≦Peel adhesive force4<0.20N / 0.3mm B:0.10N / 0.3mm≦Peel adhesive force4<0.15N / 0.3mm C: Peel adhesion force 4<0.10N / 0.3mm

[0055] (11) Adhesion to polyester film A PET film (thickness 30 μm) was bonded to the adhesive layer surface of the laminate 1 prepared in the same manner as in (7) above using a laminator (SA-1010 manufactured by Tester Sangyo Co., Ltd.) under conditions of a temperature of 180°C, a linear pressure of 40 N / cm, and a speed of 1.0 m / min, thereby obtaining a laminate 4 laminated in the order of PET film / adhesive layer / PET film. A 25 mm wide test piece was prepared from the obtained laminate 4, and a test was performed at a tensile speed of 50 mm / min in an atmosphere of 23°C using an Autograph AG-2 manufactured by Shimadzu Corporation to measure the T-type peel adhesion (peel adhesion 3). The test piece that caused material failure in the peel test was rated as passing (S).

[0056] The following materials were used as raw materials for the polyester resin composition. [Polyester resin (A-1)] In an esterification reactor, 20.6 parts by mass of polybutylene terephthalate, 16.4 parts by mass of terephthalic acid, 7.0 parts by mass of adipic acid, 16.2 parts by mass of 1,4-cyclohexane dimethanol, 17.6 parts by mass of triethylene glycol, and 0.12 parts by mass of Irganox 1010 (manufactured by BASF) were charged, and the esterification reaction was carried out at a temperature of 215 ° C. for 4 hours. After the obtained esterification product was transferred to a polycondensation reaction tank, 0.03 parts by mass of tetrabutyl titanate was added as a polycondensation catalyst. Next, the pressure in the reaction system was gradually reduced to 0.4 hPa over 90 minutes, and a polyester resin (A-1) having a glass transition temperature of 10 ° C. and a melting point of 140 ° C. was used, which was obtained by carrying out a polycondensation reaction at 245 ° C. for 7 hours.

[0057] [Polyester resins (A-2) to (A-12)] A polyester resin obtained in the same manner as for polyester resin (A-1) was used, except that the amounts of components charged into the esterification reactor were changed so as to obtain a polyester resin having the composition shown in Table 1.

[0058] Table 1 shows the compositions and characteristic values ​​of the polyester resins (A-1) to (A-12).

[0059] [Table 1]

[0060] [Nitrogen-containing heterocyclic compound] B-1: 1,2,3-benzotriazole (BT-120, manufactured by Johoku Chemical Co., Ltd.) B-2: Carboxybenzotriazole (CBT-1, manufactured by Johoku Chemical Co., Ltd.) B-3: 5-Methylbenzotriazole (5M-BTA, manufactured by Johoku Chemical Co., Ltd.) B-4: 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole (BT-LX, manufactured by Johoku Chemical Co., Ltd.) B-5: 1,2,3-benzotriazole sodium salt aqueous solution (JCL-400, manufactured by Johoku Chemical Co., Ltd.) B-6: 1-Hydroxybenzotriazole (Tokyo Chemical Industry Co., Ltd.) B-7: 2-Mercaptobenzothiazole (Sunmeler M, manufactured by Sanshin Chemical Industry Co., Ltd.) B-8: 2-di-n-butylamino-4,6-dimercapto-s-triazine (ACTOR BSH, Kawaguchi Chemical Industry Co., Ltd.)

[0061] [Silane coupling agent] C-1: 3-aminopropyltriethoxysilane (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) C-2: 3-glycidoxypropyltrimethoxysilane (KBM-403, Shin-Etsu Chemical Co., Ltd.) C-3: 3-isocyanatepropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd. KBE-9007)

[0062] [Isocyanate Compound] D-1: Hexamethylene diisocyanate Isocyanurate Body (Asahi Kasei TPA-100) D-2: 4,4-diphenylmethane diisocyanate (Kanto Chemical) D-3: 2,4- / 2,6-toluene diisocyanate [80 / 20 mixture] (Tosoh Corporation, Coronate T-80) D-4: Tris(phenylisocyanate)thiophosphate (Desmodur RFE, manufactured by Covestro)

[0063] Flame retardant: Bis(pentabromophenyl)ethane (SAYTEX8010 manufactured by Albemarle) Flame retardant assistant: Antimony trioxide (manufactured by Yamanaka Sangyo Co., Ltd.) Pigment: Titanium oxide (manufactured by Fuji Titanium Industry Co., Ltd.) Filler: Silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.)

[0064] Example 1 20 parts by mass of polyester resin (A-1), 48 parts by mass of dichloromethane, 9.6 parts by mass of toluene, and 2.4 parts by mass of methyl ethyl ketone were placed in a 100 mL glass bottle containing glass beads having a diameter of 2 mm, sealed with a metal cap, and then completely dissolved at 23°C for 1 hour in a Seiwa Giken high-speed ball mill (Rocking Mill RM-50). Next, 80 parts by mass of the above solution were charged with 10 parts by mass of bis(pentabromophenyl)ethane as a flame retardant, 7.2 parts by mass of antimony trioxide as a flame retardant assistant, 2 parts by mass of titanium oxide as a pigment, and 0.8 parts by mass of silica as a filler, and dispersed in the same ball mill at 23°C for 1 hour. Furthermore, 0.2 parts by mass of a nitrogen-containing heterocyclic compound (B-1), 0.2 parts by mass of a silane coupling agent (C-1), and 0.62 parts by mass of an isocyanate compound (D-1) were added to the above solution, and the mixture was stirred and mixed in the same ball mill at 23°C for 30 minutes to obtain an adhesive that is a solution of a polyester resin composition containing a polyester resin and a nitrogen-containing heterocyclic compound.

[0065] Examples 2 to 44, Comparative Examples 1 to 5 An adhesive, which was a solution of a polyester resin composition, was prepared in the same manner as in Example 1, except that the types of polyester resin, nitrogen-containing heterocyclic compound, silane coupling agent, and isocyanate compound, and the parts by mass of each component in the polyester resin composition were changed to those shown in Tables 2 and 3.

[0066] The compositions and evaluation results of the polyester resin compositions of Examples 1 to 44 and Comparative Examples 1 to 5 are shown in Tables 2 and 3.

[0067] [Table 2]

[0068] [Table 3]

[0069] As is clear from Tables 2 and 3, the adhesives using the polyester resin compositions obtained in Examples 1 to 44 had excellent adhesion to non-plated copper, high adhesion retention after salt spray treatment, and excellent salt water resistance.

[0070] On the other hand, the polyester resin compositions of Comparative Examples 1 and 2 had poor adhesion retention after salt spray treatment because the content of the nitrogen-containing heterocyclic compound was less than 0.05 parts by mass per 100 parts by mass of the polyester resin. The polyester resin composition of Comparative Example 3 had poor adhesion to non-plated copper because the content of the nitrogen-containing heterocyclic compound was more than 10 parts by mass per 100 parts by mass of the polyester resin. The polyester resin composition of Comparative Example 4 had a resin glass transition temperature of less than -20°C, so the elastic modulus at room temperature was low and the adhesive strength to non-plated copper was poor.The polyester resin composition of Comparative Example 5 had a resin glass transition temperature of more than 30°C, so the elastic modulus at room temperature was high and the adhesive strength to non-plated copper was poor.

Claims

1. The composition contains 100 parts by mass of a polyester resin (A), 0.05 to 10 parts by mass of a nitrogen-containing heterocyclic compound (B), 0.1 to 5 parts by mass of a silane coupling agent (C), and 1 to 5 parts by mass of an isocyanate compound (D), The polyester resin (A) has a glass transition temperature of −20 to 30° C., the nitrogen-containing heterocyclic compound (B) is one or more compounds selected from the group consisting of benzotriazole compounds, mercaptobenzothiazole compounds, and triazinethiol compounds; The silane coupling agent (C) has an amino group as a terminal group, A polyester resin composition, wherein the isocyanate compound (D) is an isocyanurate of hexamethylene diisocyanate.

2. 2. The polyester resin composition according to claim 1, wherein the benzotriazole compound is a compound represented by the following general formula (1): 【Chemistry 1】 [In formula (1), R １ represents a hydrogen atom, a substituted alkyl group or an alkali metal; R ２ represents a hydrogen atom, a methyl group, or a carboxy group.

3. The polyester resin composition according to claim 1 or 2, characterized in that the polyester resin (A) contains, as acid components, 60 to 90 mol % of terephthalic acid and 10 to 40 mol % of an aliphatic dicarboxylic acid having 4 to 15 carbon atoms, and contains, as a glycol component, 25 to 55 mol % of 1,4-cyclohexanedimethanol.

4. 4. The polyester resin composition according to claim 1, wherein the polyester resin (A) has a melting point of 110 to 150°C.

5. An adhesive comprising the polyester resin composition according to any one of claims 1 to 4.

6. A laminate comprising a layer containing the polyester resin composition according to any one of claims 1 to 4.

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