JP5398456B2 - Polyester resin composition, adhesive comprising the polyester resin composition, and laminate using the adhesive - Google Patents

Description

  The present invention relates to a polyester resin composition excellent in heat resistance and transparency. Further, the present invention relates to an adhesive that is useful as an adhesive for electrical appliances, automobile-related optical materials, and wiring agents, and has excellent adhesion to metals and glass, and a laminate using the adhesive.

  Polyester resins represented by polyethylene terephthalate and polybutylene terephthalate have excellent mechanical strength, thermal stability, hydrophobicity, and chemical resistance, and are widely used in various fields as fibers, films, molding materials, etc. .

  Moreover, by making the dicarboxylic acids and glycols that are constituent components specific, it is possible to obtain copolymer polyester resins having various characteristics, and they can be widely used in adhesives, coating agents, ink binders, paints, etc. It is used. Such a copolyester resin generally exhibits excellent adhesion to plastics such as polyester resin, polycarbonate resin, and polyvinyl chloride resin, or metal foil such as aluminum and copper.

  Utilizing these characteristics, the adhesive using the copolyester resin is widely used, for example, as an adhesive for flexible flat cables and optical panels widely used as wiring materials for household appliances or automobiles. ing.

  In recent years, optical materials such as flat panels and touch panels have been made thinner and smaller, so the influence of various heat sources such as backlights on liquid crystal screens and heat radiation from CPUs (central processing units) is large. It has become to. That is, the demand regarding the heat resistance with respect to the adhesive agent used for a flat panel etc. is increasing. Polyester adhesives have better heat resistance than acrylic adhesives, but are still insufficient for obtaining heat resistance against heat dissipation from the heat source.

  In order to solve such problems, an adhesive composed of an amorphous solvent-soluble polyester resin obtained by mixing a resin having a high glass transition temperature and a resin having a low glass transition temperature for the purpose of achieving both adhesion and heat resistance. An agent has been studied (for example, Patent Document 1). However, in this case, the heat resistance is insufficient.

  In addition, an adhesive using a crystalline solvent-soluble resin has been studied (for example, Patent Document 2). However, in this case, although the heat resistance is improved, there is a problem that the transparency is lowered due to whitening accompanying crystallization, so that it is not suitable for an optical member.

  In contrast, an adhesive using a polyester resin having both transparency and crystallinity has been studied (Patent Document 3). However, in this case, the solubility in general-purpose solvents such as toluene is poor and the handleability is poor, and the adhesiveness is extremely poor.

JP 2008-19375 A Japanese Patent No. 3212046 JP-A-5-132548

  The object of the present invention is to provide a solvent-soluble adhesive suitable for optical materials that require transparency and heat resistance, and has compatibility when a crystalline polyester resin and an amorphous polyester resin are mixed. An object of the present invention is to provide a polyester resin composition that is very high, can dramatically improve heat resistance while maintaining transparency, and is excellent in adhesiveness. Another object of the present invention is to provide an adhesive comprising the polyester resin composition, suitably used for a flexible flat cable because of its heat resistance and high adhesiveness, and a laminate using the adhesive.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the gist of the present invention is as follows.
(1) A polyester resin composition comprising a crystalline polyester resin (A) and an amorphous polyester resin (B) and satisfying the following (i) to (v) simultaneously.
(I) The glass transition temperature of the crystalline polyester resin (A) is less than 30 ° C, and the glass transition temperature of the amorphous polyester resin (B) is less than 40 ° C.
(Ii) The mixing ratio of the crystalline polyester resin (A) and the amorphous polyester resin (B) is (A) / (B) = 20/80 to 98/2 in terms of mass ratio.
(Iii) Each of the crystalline polyester resin (A) and the amorphous polyester resin (B) contains 2 to 50 mol% of polyalkylene glycol.
(Iv) The crystalline polyester resin (A) contains 50 to 70 mol% of terephthalic acid and 30 mol% of adipic acid as acid components.
(V) 1,4-butanediol as a glycol component in the crystalline polyester resin (A) is 25 to 49 mol% and 1,4-cyclohexane dimethanol is contained 25 to 49 mol%.
(2) The polyester resin composition according to (1), wherein the heat of fusion Q measured using a differential scanning calorimeter in accordance with JIS K 7121 is 0.2 to 10 J / g.
(3) The polyester resin according to (1) or (2), wherein the polyalkylene glycols contained in the crystalline polyester resin (A) and the amorphous polyester resin (B) are different polyalkylene glycols. Composition.
(4) Solid state of crystalline polyester resin (A) and amorphous polyester resin (B) when crystalline polyester resin (A) and amorphous polyester resin (B) are dissolved in a mixed solution of toluene and methyl ethyl ketone The polyester resin composition according to any one of (1) to (3), wherein the total concentration is 5 to 50% by mass.
(5) The crystalline polyester resin (A) and the amorphous polyester resin (B) so that the total solid concentration of the crystalline polyester resin (A) and the amorphous polyester resin (B) is 50% by mass. The polyester resin composition according to any one of (1) to (4), wherein the total light transmittance of a solution obtained by dissolving a lysate in a mixed solution of toluene and methyl ethyl ketone is 90% or more.
(6) An adhesive comprising a polyester resin composition and an organic solvent, the adhesive comprising the polyester resin composition (1) to (5) and an organic solvent.
(7) A laminate comprising a resin layer and a substrate using the adhesive of (6).
(8) The laminate according to (7), wherein two or more resin layers are laminated.
(9) The laminate according to (7) or (8), which is used for a flexible flat cable.

  According to the present invention, a resin composition excellent in transparency and heat resistance can be obtained. Furthermore, the adhesive obtained from the resin composition is excellent in adhesiveness, and can be suitably used as an adhesive for optical members that require transparency and heat resistance. Moreover, the laminated body using this adhesive agent can be used suitably for a flexible flat cable from the heat resistance and the high adhesiveness.

Hereinafter, the present invention will be described in detail.
The polyester resin composition of the present invention (hereinafter sometimes simply referred to as “resin composition”) includes a crystalline polyester resin (A) (hereinafter sometimes simply referred to as “resin A”), an amorphous property, and Polyester resin (B) (hereinafter sometimes simply referred to as “resin B”).

First, the resin A will be described.
The resin (A) used in the present invention is required to have a glass transition temperature of less than 30 ° C, preferably less than 20 ° C, and more preferably less than 10 ° C. When the glass transition temperature exceeds 30 ° C., an adhesive is obtained using the resin A and the resin B, which is not preferable because adhesive strength to a base material described later is lowered. As a minimum of glass transition temperature, -50 ° C is preferred and -30 ° C is still more preferred. When the glass transition temperature is less than −50 ° C., when the adhesive is obtained using the resin A and the resin B, the adhesiveness is too strong and the handling property may be lowered.

  Resin A is a polyester resin having crystallinity. In the present invention, the crystallinity means a crystal melting point at the time of re-heating crystallization and a heat of fusion Q of 0.1 J when measured according to JIS K 7121 using a DSC (differential scanning calorimeter). / G or more. More preferably, the heat of fusion Q is 0.5 J / g or more.

  As an acid component of resin A, it is necessary to contain both terephthalic acid and adipic acid. By including any of terephthalic acid and adipic acid, the crystallinity of the resin A is expressed, and the heat resistance of the polyester resin composition of the present invention can be improved.

From the viewpoint of heat resistance, the content of terephthalic acid in the resin A needs to be 50 to 70 mol % .
The content of adipic acid in the resin A needs to be blended at 30 mol% from the viewpoint of promoting crystallization.

  As a glycol component of resin A, it is necessary to contain both 1,4-butanediol and 1,4-cyclohexanedimethanol. By including both 1,4-butanediol and 1,4-cyclohexanedimethanol, the crystallinity and solubility of the resin A can be improved.

From the viewpoint of promoting crystallinity, the content of 1,4-butanediol in the resin A needs to be blended at 25 to 49 mol%.
From the viewpoint of improving solubility, the content of 1,4-cyclohexanedimethanol in the resin A needs to be 25 to 49 mol%.

  Resin A may contain components other than terephthalic acid, adipic acid, 1,4-butanediol, and 1,4-cyclohexanedimethanol (hereinafter may be referred to as “other components”). Other components include naphthalenecarboxylic acid, isophthalic acid, 5-sodium-sulfoisophthalic acid, sebacic acid, azelaic acid, succinic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, undecanedioic acid, dodecanedioic acid, Acid components such as tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosandioic acid, docosanedioic acid, hexahydroterephthalic acid; 1,6-hexane Diol, ethylene glycol, 1,3-propanediol, polytetramethylene glycol, polyethylene glycol, dimer diol, hydrogenated dimer diol, 1,5-pentanediol, 1,7-heptanediol, ethylene oxide adduct of bisphenol A, bisphenol S Glycol components such as ethylene oxide adducts; tetrahydrophthalic acid, lactic acid, oxirane, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, Hydroxycarboxylic such as 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, 4- (β-hydroxy) ethoxybenzoic acid Acids; aliphatic lactones such as β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone. These other components can be used alone or in combination of two or more.

  The number average molecular weight of the resin A is preferably 5000 to 30000, more preferably 8000 to 28000, and particularly preferably 10000 to 26000, from the viewpoints of adhesiveness and handling properties when used as an adhesive.

  The organic solvent in which the resin A is dissolved includes a non-halogen solvent or a non-ether solvent. The organic solvent is not particularly limited, and specifically, aromatic solvents such as toluene, xylene, solvent naphtha and solvesso; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; methyl alcohol, ethyl alcohol and isopropyl Alcohol solvents such as alcohol and isobutyl alcohol; ester solvents such as ethyl acetate and normal butyl acetate; acetate solvents such as cellosolve acetate and methoxyacetate; or a mixture obtained by mixing two or more of the above solvents Can be mentioned. Of these, from the viewpoint of improving the drying efficiency, a mixed solution obtained by mixing toluene and methyl ethyl ketone is preferable. The mixing ratio of toluene and methyl ethyl ketone is preferably 10/90 to 90/10 in mass ratio.

  Resin A needs to contain polyalkylene glycol. Although the containing form is not specifically limited, It is preferable to contain by block copolymerization. By block copolymerization of polyalkylene glycol with resin A, compatibility with resin B can be increased, and transparency of the resulting resin composition can be achieved by mixing both in a transparent and uniform manner. .

  Examples of the polyalkylene glycol contained in the resin A include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, ethylene oxide adduct of bisphenol A, and propylene oxide addition polymer of bisphenol A. Is mentioned.

  From the viewpoint of compatibility when the resin A and the resin B are mixed, the number average molecular weight of the polyalkylene glycol contained in the resin A is preferably 60 to 10,000, more preferably 100 to 5000, and particularly preferably 150 to less than 2500. preferable.

  The content of the polyalkylene glycol contained in the resin A needs to be 2 to 50 mol%, and preferably 4 to 40 mol%. When the content ratio of the polyalkylene glycol is less than 2 mol%, the compatibility with the resin B is lowered, and when the adhesive is obtained using the resin A as described later, In this case, the total light transmittance is lowered, and transparency is lost. Moreover, when content exceeds 50 mol%, heat resistance and adhesiveness will fall.

  The resin A may be copolymerized with a monocarboxylic acid or a monoalcohol for the purpose of adjusting the molecular weight. Examples of monocarboxylic acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, and the like. It is done. Examples of the monoalcohol include octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, 2-phenoxyethanol and the like.

Next, the resin B will be described.
Resin B is an amorphous polyester resin. The resin B needs to have a glass transition temperature of less than 40 ° C., preferably −10 to 39 ° C., more preferably −8 to 37 ° C. When the glass transition temperature exceeds 40 ° C., the compatibility with the resin A is lowered, which is not preferable.

The components constituting the resin B will be described.
Examples of the acid component of the resin B include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, succinic acid, adipic acid, glutaric acid, azelaic acid, sebacic acid, dodecanedioic acid and the like. However, crystallinity tends to increase when terephthalic acid and adipic acid are used in combination. Therefore, adipic acid and terephthalic acid may be blended alone or in combination with an acid component other than adipic acid and terephthalic acid, but adipic acid and terephthalic acid must not be used in combination.

  As the glycol component of resin B, ethylene glycol, 1,4-cyclohexanedimethanol, 1,4-butanediol, 1,3-propanediol, 1,5-pentanediol, ethylene oxide adduct of bisphenol A, bisphenol A Examples include propylene oxide adducts, ethylene oxide adducts of bisphenol S, tricyclodecane dimethanol, spiroglycol and the like. However, when 1,4-cyclohexanedimethanol and 1,4-butanediol are used in combination, the crystallinity tends to increase. Therefore, 1,4-cyclohexanedimethanol and 1,4-butanediol may be blended alone or in combination with glycol components other than 1,4-cyclohexanedimethanol and 1,4-butanediol. Do not use in combination. Tetrahydrophthalic acid, lactic acid, oxirane, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyvaleric acid, 3 -Hydroxy carboxylic acids such as hydroxy valeric acid, 4-hydroxy valeric acid, 5-hydroxy valeric acid, 6-hydroxy caproic acid, 10-hydroxy stearic acid, 4- (β-hydroxy) ethoxybenzoic acid; β-propiolactone And aliphatic lactones such as β-butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone.

  The polymerization average molecular weight of the resin B is preferably 5000 to 30000, more preferably 8000 to 28000, further preferably 11000 to 26000, and most preferably 14,000 to 24,000. When the polymerization average molecular weight is less than 5,000, the heat resistance may be lowered. When the polymerization average molecular weight is more than 30,000, the polymerization time becomes longer and the productivity is lowered.

Examples of the organic solvent for dissolving the resin B include those exemplified as the organic solvent for dissolving the resin A.
The resin B needs to contain polyalkylene glycol. Although the containing form is not specifically limited, It is preferable to contain by block copolymerization. By containing polyalkylene glycol in the resin B, the compatibility with the resin A can be increased, and the transparency of the resulting resin composition can be achieved by mixing both uniformly and transparently. Moreover, since the polyalkylene glycol is contained in the resin B, the glass transition temperature of the resin B can be controlled to less than 40 ° C.

  Examples of the polyalkylene glycol contained in the resin B include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, ethylene oxide adduct of bisphenol A, and propylene oxide addition polymer of bisphenol A. Is mentioned.

  From the viewpoint of compatibility when the resin A and the resin B are mixed, the number average molecular weight of the polyalkylene glycol contained in the resin B is preferably 60 to 10,000, more preferably 100 to 5000, and particularly preferably 150 to less than 2500. preferable.

  The content of polyalkylene glycol in the resin B needs to be 2 to 50 mol%, and preferably 4 to 40 mol%. When the content ratio of the polyalkylene glycol is less than 2 mol%, the compatibility with the resin A is lowered, and when the adhesive is obtained using the resin A and the resin B as described later, the adhesive is used. When it is made into a laminated body, the total light transmittance is lowered and transparency is lost. Moreover, when content exceeds 50 mol%, heat resistance and adhesiveness will fall.

  The polyalkylene glycol used in the resin A and the polyalkylene glycol used in the resin B may be the same polyalkylene glycol, but from the viewpoint of improving heat resistance and compatibility, different polyalkylene glycols may be used. Preferably there is.

  In the present invention, from the viewpoint of increasing the compatibility with the resin A, the resin B may be copolymerized with an aliphatic glycol having a side chain. Examples of the aliphatic glycol having a side chain include 2-methyl-1,3-propanediol, 2,2′-diethyl-1,3-propanediol, 2-ethyl-2-methyl-1,3-propanediol, Examples include 2-butyl-2-ethyl-propanediol, 3-methyl-1,5-pentadiol, neopentyl glycol and the like. Among these, neopentyl glycol is preferable from the viewpoint of being economically available at a low cost and preventing a decrease in heat resistance. The aliphatic glycols having the above side chains can be used alone or in combination of two or more. Among aliphatic glycols having a side chain, 1,2-propylene glycol has a side chain having a rigid structure. Therefore, when blended with resin B, the glass transition temperature of resin B is 40 ° C. or higher. . In such a case, there is a problem that the transparency is lowered when an adhesive or a laminate described later is obtained, which is not preferable.

  The resin B may be copolymerized with a monocarboxylic acid or a monoalcohol for the purpose of adjusting the molecular weight. Specific examples of the monocarboxylic acid and monoalcohol include those exemplified as the monocarboxylic acid and monoalcohol copolymerizable with the resin A.

Next, the manufacturing method of resin A and resin B is demonstrated.
In the present invention, resin A and resin B are obtained by injecting the necessary monomer raw materials into the reaction vessel, performing an esterification reaction at a temperature of 180 ° C. or more for 4 hours or more, and then performing polycondensation. Can do. The polycondensation reaction may be a known method. For example, the resin A and the resin B can be obtained by proceeding the condensation reaction at a temperature of 220 to 280 ° C. until reaching a desired molecular weight under a reduced pressure of 130 Pa or less.

A polymerization catalyst may be used in the esterification reaction and polycondensation reaction. The polymerization catalyst is not particularly limited, but includes titanium compounds such as tetrabutyl titanate; metal acetates such as zinc acetate and magnesium acetate; organotin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octylate. . The amount of the polymerization catalyst, the acid component per mol is preferably 0.1 × ^{10 -4} ~20 × ¹⁰ -4 mol.

  To the resin A and the resin B, after the polycondensation reaction is completed, the terminal hydroxyl group in the resin A and the resin B structure is modified to a carboxyl group by adding and reacting a polybasic acid component or its anhydride, An appropriate acid value can be imparted by introducing a carboxyl group into the molecular chains of Resin A and Resin B by transesterification.

  The polyester resin composition of the present invention is obtained by mixing the resin A and the resin B as described above. Since the resin A is crystalline and has a property that the resin hardly softens to the crystalline melting point, it plays a role of imparting high heat resistance to the resin composition. Moreover, since resin B is amorphous, it also plays a role in imparting transparency to the resin composition. Therefore, by mixing the resin A and the resin B, heat resistance can be imparted while maintaining high transparency. Furthermore, since the resin composition of the present invention uses the resin A and the resin B in which polyalkylene glycol is copolymerized, the compatibility between the resin A and the resin B is excellent, so that the transparency is remarkably excellent. is there.

  The mixing ratio of the resin A and the resin B is a mass ratio, and it is necessary that (A) / (B) = 20/80 to 98/2, and preferably 30/70 to 80/20, It is more preferably 35/65 to 75/25, further preferably 40/60 to 70/30, particularly preferably 45/55 to 65/35, and 50/50 to 60/40. Most preferred. When the mixing ratio is less than 20/80, heat resistance is insufficient. On the other hand, when it exceeds 98/2, transparency when used as an adhesive is insufficient.

  The resin composition of the present invention preferably has a heat of fusion Q measured according to JIS K 7121 using a differential scanning calorimeter (DSC) of 0.2 to 10 J / g, 0.3 to More preferably, it is 5 J / g, and most preferably 0.3 to 4 J / g. If the heat of fusion is less than 0.2 J / g, the heat resistance may decrease, and if it exceeds 10 J / g, the solubility in organic solvents may decrease, which is not preferable.

  Since the resin composition of the present invention has crystallinity, it also has heat resistance. The melting point Tm of the resin composition is preferably 85 to 150 ° C, more preferably 90 to 140 ° C, and most preferably 95 to 130 ° C. If the melting point Tm is less than 85 ° C, the heat resistance may be inferior, and if the melting point Tm exceeds 150 ° C, the solubility in an organic solvent may be lowered.

  It is preferable that the resin A and the resin B are dissolved in an organic solvent. The total solid content concentration of resin A and resin B at that time is preferably 5 to 50% by mass, more preferably 10 to 50% by mass, and still more preferably 15 to 50% by mass, It is particularly preferably 20 to 50% by mass, and most preferably 25 to 45% by mass. When the total solid content concentration of the resin A and the resin B is less than 5% by mass, when an adhesive is prepared using a resin composition as described later, a sufficient coating amount is applied to the substrate. I can't. Further, when the total solid content concentration of the resin A and the resin B exceeds 50% by mass, the viscosity becomes too high. Therefore, when the adhesive obtained using the resin composition is applied to the substrate, the thickness is increased. It becomes difficult to apply with high accuracy.

  The transparency of the solution when resin A and resin B are dissolved in an organic solvent is measured when the total solid content concentration of resin A and resin B is 50% by mass and dissolved in an organic solvent. The total light transmittance of the solution is preferably 90% or more, and more preferably 95% or more. If it is less than 90%, the solubility of the resin composition in the organic solvent is insufficient, and the compatibility between the resin A and the resin B becomes insufficient. Therefore, when used as an adhesive, transparency, heat resistance, Adhesiveness may not be expressed.

  In the resin composition, if necessary, a heat stabilizer such as phosphoric acid and phosphate ester; an antioxidant such as a hindered phenol compound, a hindered amine compound, and a thioether compound, as long as the effects of the present invention are not impaired. A lubricant such as talc and silica; a pigment such as titanium oxide; a filler; an antistatic agent; and a conventionally known additive such as a foaming agent.

Next, the adhesive obtained from the resin composition of the present invention will be described.
The adhesive of the present invention can be obtained by mixing the resin A and the resin B to obtain a resin composition and dissolving the resin composition in an organic solvent. In the present invention, since the compatibility between the resin A and the resin B after being dissolved in an organic solvent is excellent, the mixed solution is prevented from being phase-separated or clouded, and the adhesive is applied to the substrate. Even after this, a transparent and uniform coating film can be formed.

  Examples of the method for dissolving the resin composition in the organic solvent include a method in which the resin composition is added to the organic solvent, and then heated to room temperature to about 50 ° C. and stirred. It is also possible to mix the resin A and the resin B after separately dissolving them in an organic solvent.

A solution in which the resin composition is dissolved in an organic solvent (hereinafter sometimes simply referred to as “solution”) can be filtered through a filter and stored in a container as necessary.
A flame retardant can be added to the above solution as necessary. Examples of the flame retardant include, but are not limited to, halides such as decabromodiphenyl ether, bis (pentabromophenyl) ethane, tetrabromobisphenol, hexabromocyclododecane, and hexabromobenzene; triphenyl phosphate, tricresyl phosphate, Phosphorus compounds such as 1, -phenylenebis (diphenyl phosphate), ammonium polyphosphate, polyphosphate amide, and guanidine phosphate; halogen-containing phosphate esters such as tris (chloroethyl) phosphate and tris (dichloropropyl) phosphate; red phosphorus; triazine and melamine Nitrogen flame retardants such as isocyanurate and ethylene dimelamine; inorganic flame retardants such as tin dioxide, antimony pentoxide, antimony trioxide, aluminum hydroxide, magnesium hydroxide; Dah and the like. Among the above flame retardants, it is preferable to select a non-halogen flame retardant, a non-phosphorus flame retardant, and a deuterium metal flame retardant from the viewpoint of reducing the environmental load.

  In the above-mentioned solution, as necessary, epoxy resins; acid anhydrides; isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate; block of isocyanates Isocyanates; Uretodiones; Curing agents such as β-hydroxyalkylamides; Curing catalysts such as triethylenediamine and triethylamine; Pigments such as titanium dioxide, calcium carbonate and zinc oxide; Talc; Polyethylene wax, paraffin wax, tackifier, etc. be able to.

  The adhesive of the present invention obtained as described above can be applied to an appropriate substrate by the following method. First, the above-mentioned solution is applied to a substrate by a known coating method, and then subjected to a drying process to form a resin layer to obtain a laminate.

  The resin layer in the present invention has heat resistance. As an index indicating heat resistance, for example, in a resin layer having a thickness of 30 μm, measurement is performed with a thermomechanical analyzer (“TMA-120” manufactured by SII Nanotechnology Co., Ltd.) (load: 2 gf, temperature increase rate: 5 ° C./min). The softening point is preferably 90 ° C. or higher, more preferably 93 ° C. or higher.

  Examples of the coater used for coating include a bar coater, a comma coater, a die coater, a roll coater, a reverse roll coater, a gravure coater, a gravure reverse coater, and a flow coater. In the coating method using these coaters, the thickness of the resin layer can be arbitrarily controlled. In addition, a resin layer may be laminated | stacked on two or more layers by attaching | subjecting to the coating process of multiple times, when thick coating cannot be performed at once.

The thickness of the resin layer is preferably 0.1 to 30 μm from the viewpoints of adhesiveness and transparency.
The substrate can be arbitrarily selected from, for example, a film made of polyester such as polyethylene terephthalate and polycyclohexanedimethyl terephthalate, polycarbonate, acrylic, and an inorganic glass plate. Among these, an inorganic glass plate is particularly preferable from the viewpoint of transparency.

Although the thickness of a base material is not specifically limited, It is preferable that it is 10-100 micrometers.
In the present invention, if necessary, an appropriate primer layer may be provided between the base material and the resin layer.

In the laminate of the present invention, the resin layer applied to the base material has thermoplasticity, so that it can be heat sealed to another adherend.
The laminate of the present invention is remarkably excellent in transparency. The transparency varies depending on the thickness of the base material and resin layer used. For example, a resin layer is provided on a 38 μm thick polyethylene terephthalate film having a haze value of 5% so that the thickness after drying is 10 μm. In the laminate, the transparency is preferably such that the total light transmittance measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., HazeMeter NDH2000) is 70% or more, more preferably 75% or more. preferable. In particular, the total light transmittance is preferably 80% or more in the use of an adhesive for applications where importance is attached to the transparency of the resin layer.

  The resin composition of the present invention comprises a crystalline polyester resin (A) composed of terephthalic acid, adipic acid, butanediol and 1,4-cyclohexanedimethanol and having a glass transition temperature of less than 30 ° C., and a glass transition temperature of 40. Since the amorphous polyester resin (B) having a temperature of less than 0 ° C. is mixed in a specific ratio, the heat resistance and the adhesiveness are excellent, and the transparency is remarkably excellent. Therefore, the adhesive obtained by using the resin composition can be used for adhesion of electric / electronic parts and automobile parts, and is particularly suitable for adhesion of optical materials. Various adhesives using light bulbs and LEDs are used. It can be suitably used for adhesion and sealing of components such as lighting, indicator lamps and displays. Furthermore, since the laminated body using this adhesive agent is excellent in transparency and heat resistance, it is suitably used for a flexible flat cable.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
The evaluation method used in the present invention is shown below.

(1) Copolymerization composition of polyester resin Using a high resolution nuclear magnetic resonance apparatus (“JNM-LA400” manufactured by JEOL Ltd.), ¹ H-NMR analysis is performed to determine the composition from the peak intensity of each copolymer component. Asked. The analysis conditions are shown below.
Frequency: 400MHz
Solvent: Deuterated trifluoroacetic acid Temperature: 25 ° C
(2) Number average molecular weight (Mn) of polyester resin
It was determined by a liquid feeding unit (manufactured by Shimadzu Corporation, “LC-10ADvp type”) and an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, “SPD-6AV type”, detection wavelength: 254 nm, solvent: tetrahydrofuran, polystyrene conversion). .

(3) Glass transition temperature (Tg), melting point (Tm), heat of fusion (Q) of polyester resin
It measured based on JIS-K7121 using the input compensation type | mold differential scanning calorimetry apparatus (the Perkin-Elmer company make, "diamond DSC"). First, the glass transition temperature and the melting point were measured from the DSC curve. Next, after raising the temperature to 30 ° C higher than the melting point, quenching rapidly to -50 ° C, and calculating the heat of fusion from the chart when scanning from -50 ° C to 200 ° C at a rate of temperature increase of 10 ° C / min. did.

(4) Solubility of polyester resin Polyester resin was dissolved in a solution in which toluene and methyl ethyl ketone were mixed at a ratio of toluene / methyl ethyl ketone = 8/2 (mass ratio) so that the solid content concentration was 30% by mass. Then, it left still for 2 hours in a transparent glass bottle, the uniformity was confirmed visually, and the following references | standards evaluated.
○: The layers are not separated and are uniform.
X: The layers are separated.

(5) Solubility of the polyester resin composition After mixing the polyester resin A and the polyester resin B in a predetermined blend with a solution in which toluene and methyl ethyl ketone are mixed at a ratio of toluene / methyl ethyl ketone = 8/2 (mass ratio), It was dissolved so that the solid content concentration was 30% by mass. Then, it left still for 2 hours in a transparent glass bottle, the uniformity was confirmed visually, and the following references | standards evaluated.
○: The layers are not separated and are uniform.
X: The layers are separated.

(6) Transparency of adhesive In a solution in which toluene and methyl ethyl ketone are mixed at a ratio of toluene / methyl ethyl ketone = 8/2 (mass ratio), the polyester resin composition is dissolved so that the solid content concentration becomes 30% by mass. An adhesive was prepared. An appropriate amount (for example, 50 g) of the obtained adhesive is put into a quartz glass cell, and the total light transmittance is measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., trade name “HazeMeter NDH2000”). The transparency was evaluated.
A: Total light transmittance is 90% or more.
A: The total light transmittance is 85% or more and less than 90%.
X: The total light transmittance is less than 85%.

(7) Adhesiveness of adhesive An adhesive was obtained in the same manner as in (5) above. The obtained adhesive was applied to a stainless steel plate having a thickness of 0.3 mm using a bar coater and dried at 120 ° C. for 2 minutes to form a resin layer having a thickness of 20 μm to produce a laminate sheet. On this laminating sheet, a 38 μm-thick polyethylene terephthalate film (manufactured by Unitika Ltd., “Emblet S-38”) is overlaid with a non-corona-treated surface and pressed at 180 ° C. for 1 minute at a pressure of 100 kPa. Thus, a laminate sheet was obtained. The obtained laminate sheet was cut to a width of 25 mm, and a peel test was performed at 23 ° C. using a peel tester (manufactured by Intesco, “Model 2001”) to measure peel strength. Evaluation was made according to the following criteria.
○: Peel strength is 15 N / 25 mm or more.
X: Peel strength is less than 15 N / 25 mm.

(8) Melting point (Tm) of resin layer, heat of fusion (Q)
In the same manner as in (3), the melting point (Tm) and heat of fusion (Q) of the resin layer were measured.
(9) Softening point of resin layer (Ts)
An adhesive was obtained in the same manner as in (5) above. A 50 μm-thick polypropylene film (“PA20” manufactured by Sun Tox Co., Ltd.) was coated with the obtained adhesive using a bar coater so that the thickness was 30 μm, dried at 120 ° C. for 2 minutes, A laminated body was produced by forming a resin layer having a thickness of 10 μm. Thereafter, the resin layer is peeled off from the polypropylene film, and this resin layer is subjected to a load of 2 gf and a temperature rising rate with a penetration probe using a thermomechanical analyzer (“TMA-120” manufactured by SII Nano Technology). The softening point Ts was measured at 5 ° C./min. The heat resistance was evaluated according to the following criteria.
○: Softening point Ts is 90 ° C. or higher.
X: Softening point Ts is less than 90 ° C.
(10) Transparency of laminate An adhesive was obtained in the same manner as (5) above. A 38 μm-thick polyethylene terephthalate film (“Embret S-38” manufactured by Unitika Ltd.) (haze value: 5%) was coated with a bar coater so that the thickness was 30 μm, and 120 The laminate was dried at 2 ° C. for 2 minutes to form a resin layer having a thickness of 10 μm after drying. The total light transmittance was measured using a haze meter (“HazeMeter NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.), and the transparency was evaluated according to the following criteria.
A: Total light transmittance is 85% or more.
○: Total light transmittance is 70% or more.
X: Total light transmittance is less than 70%.
In the present invention, those having a value of ◯ or more are assumed to be practically usable.
(11) Solid content concentration (mass%) of polyester resin and adhesive
An appropriate amount (for example, 5 g) of a polyester resin dissolved in an organic solvent obtained in the same manner as in the above (4) or an adhesive obtained in the same manner as in the above (5) is weighed, and the residue (solid content) ) Until the mass becomes constant (ie, the amount that the residue does not decrease any further). The solid content concentration was calculated according to the following formula.
Solid content concentration (mass%) = mass after heating / mass before heating × 100

The raw materials used in the present invention are shown below.
(1) Acid component of resin A, terephthalic acid (manufactured by Mitsubishi Chemical Corporation, “high-purity terephthalic acid PTA”) (hereinafter sometimes referred to as TPA)
Isophthalic acid (manufactured by AGIC, “high purity isophthalic acid PIA”) (hereinafter sometimes referred to as IPA)
Adipic acid (manufactured by Asahi Kasei Corporation) (hereinafter sometimes referred to as ADA)
-Sebacic acid (manufactured by Ogura Gosei Co., Ltd.) (hereinafter sometimes referred to as SEA)
(2) Alcohol component of resin A 1,4-butanediol (manufactured by Tosoh Corporation) (hereinafter sometimes referred to as 1,4-BD)
1,4-cyclohexanedimethanol (Eastman Chemical Co., Ltd.) (hereinafter sometimes referred to as 1,4-CHDM)
・ Triethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter sometimes referred to as TEG)
Polyethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) (molecular weight: 2000) (hereinafter sometimes referred to as PEG)
1,6-hexanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter sometimes referred to as HD)
・ Ethylene glycol (manufactured by Mitsubishi Chemical Corporation) (hereinafter sometimes referred to as EG)
(3) Acid component of resin B, terephthalic acid (Mitsubishi Chemical Corporation, "high-purity terephthalic acid PTA") (hereinafter sometimes referred to as TPA)
Isophthalic acid (manufactured by AGIC, “high purity isophthalic acid PIA”) (hereinafter sometimes referred to as IPA)
-Sebacic acid (manufactured by Ogura Gosei Co., Ltd.) (hereinafter sometimes referred to as SEA)
(4) Alcohol component of resin B, ethylene glycol (manufactured by Mitsubishi Chemical Corporation) (hereinafter sometimes referred to as EG)
・ Neopentyl glycol (manufactured by Eastman Chemical Co.) (hereinafter sometimes referred to as NPG)
-Ethylene oxide adduct of bisphenol A (manufactured by Meisei Chemical Co., Ltd., “AE-2”) (hereinafter sometimes referred to as BA)
Tricyclodecane dimethanol (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter sometimes referred to as TCD)
Polypropylene glycol (manufactured by Kishida Chemical Co., Ltd.) (molecular weight: 1500) (hereinafter sometimes referred to as PPG)
Polytetramethylene glycol (BASF, “poly THF”) (molecular weight: 1000) (hereinafter sometimes referred to as PTMG)

樹脂Ａの調製例（Ａ−２）〜（Ａ−１７）
表１〜表２に示すように、酸成分、アルコール成分の種類および混合割合、その他の共重合成分を変更した以外は、（Ａ−１）と同様にして樹脂Ａを調製した。評価結果を表１および表２に示す。

樹脂Ｂの調製例（Ｂ−１）
ＴＰＡ５０モル％、ＩＰＡ５０モル％、ＥＧ３０モル％、ＮＰＧ５０モル％、ＰＰＧ２０モル％となるように、攪拌翼の付いた反応缶に投入し、１００ｒｐｍの回転数で攪拌しながら、０．２５ＭＰａの制圧下で２５０℃で５時間エステル化を行った。その後、重縮合缶へ移送して重合触媒としてテトラブチルチタネートを投入し、６０分かけて１．３ｈＰａになるまで徐々に減圧していき、分子量が１６０００となるまで２６０℃で重縮合反応を行い、ポリエステル樹脂（Ｂ−１）を得た。得られた樹脂（Ｂ−１）のＴｇは３０℃であった。評価結果を表３に示す。

樹脂Ｂの調製例（Ｂ−２）〜（Ｂ−１１）
表３に示すように、酸成分、アルコール成分の種類および混合割合、その他の共重合性分を表３に示したように変更した以外は、（Ｂ−１）と同様にして樹脂Ｂを調製した。評価結果を表３に示す。 Preparation Example of Resin A (A-1)
TPA is 70 mol%, ADA30 mol%, 1,4-BD35 mol%, 1,4-CHDM35 mol%, TEG30 mol% is put into a reaction vessel equipped with a stirring blade and stirred at a rotation speed of 100 rpm. However, esterification was performed at 250 ° C. for 5 hours under a pressure of 0.25 MPa. Then, it is transferred to a polycondensation can and tetrabutyl titanate is added as a polymerization catalyst. The pressure is gradually reduced to 1.3 hPa over 60 minutes, and a polycondensation reaction is performed at 260 ° C. until the molecular weight reaches 20000. A polyester resin (A-1) was obtained. The obtained resin (A-1) had a Tg of −5 ° C., a Tm of 138 ° C., and a Q of 7.2 J / g. The evaluation results are shown in Table 1.

Preparation Examples of Resin A (A-2) to (A-17)
As shown in Tables 1 and 2, Resin A was prepared in the same manner as (A-1) except that the types and mixing ratios of the acid component and the alcohol component and other copolymerization components were changed. The evaluation results are shown in Tables 1 and 2.

Preparation Example of Resin B (B-1)
TPA 50 mol%, IPA 50 mol%, EG 30 mol%, NPG 50 mol%, PPG 20 mol%, put into a reaction vessel equipped with a stirring blade, and under a controlled pressure of 0.25 MPa while stirring at a rotation speed of 100 rpm The esterification was carried out at 250 ° C. for 5 hours. Then, it is transferred to a polycondensation can and tetrabutyl titanate is added as a polymerization catalyst. The pressure is gradually reduced to 1.3 hPa over 60 minutes, and a polycondensation reaction is performed at 260 ° C. until the molecular weight reaches 16000. A polyester resin (B-1) was obtained. Tg of the obtained resin (B-1) was 30 ° C. The evaluation results are shown in Table 3.

Preparation examples of resin B (B-2) to (B-11)
As shown in Table 3, resin B was prepared in the same manner as (B-1) except that the types and mixing ratios of the acid component, alcohol component, and other copolymerizable components were changed as shown in Table 3. did. The evaluation results are shown in Table 3.

また、接着剤を厚み３８μｍのポリエチレンテレフタレートフィルムにバーコーターを用いて塗工した。その後、１２０℃で２分間熱処理し、乾燥後の厚みが１０μｍとなるように樹脂層を形成し、積層体を得た。該積層体の全光線透過率を測定したところ、透過率は７５％であった。評価結果を表４に示す。 Example 1
The polyester resin (A-1) and the polyester resin (B-1) were respectively added to a glass bottle at a mixing ratio shown in Table 4, and the resin solid content obtained by adding (A-1) and (B-1) together. A mixed solvent of toluene / methyl ethyl ketone = 8/2 (mass ratio) was added so that the concentration was 30% by mass. Next, when the glass bottle was sealed and dissolved with a paint shaker, the solution was not separated into layers, and a uniformly dissolved adhesive was obtained. The total light transmittance of the solution was measured and found to be 95%. Moreover, Tm of this adhesive was 90 ° C., Q was 3.2 J / g, and Ts was 94 ° C.

The adhesive was applied to a polyethylene terephthalate film having a thickness of 38 μm using a bar coater. Then, it heat-processed for 2 minutes at 120 degreeC, the resin layer was formed so that the thickness after drying might be set to 10 micrometers, and the laminated body was obtained. When the total light transmittance of the laminate was measured, the transmittance was 75%. The evaluation results are shown in Table 4.

Examples 2-20
Adhesives and laminates were prepared and evaluated in the same manner as in Example 1 except that the types and mixing ratios of Resin A and Resin B were as shown in Tables 4 to 5. The results are shown in Tables 4-5.

比較例１〜１３
樹脂Ａと樹脂Ｂの種類と混合割合を、表６〜表７に示すようにした以外は、実施例１と同様にして、接着剤、および積層体を作製し、評価に付した。その結果を表６〜表７に示す。

実施例１〜２１においては、透明性、耐熱性に優れたポリエステル樹脂組成物を得ることができた。また、該ポリエステル樹脂組成物から得られた接着剤は、耐熱性、接着性に優れたものであった。さらに、該接着剤を用いた積層体も、透明性に優れたものであった。 Example 21
The types and mixing ratios of Resin A and Resin B are the same as in Example 1, and the adhesive and laminate are prepared so that the total solid content concentration of Resin A and Resin B is 50% by mass. It was attached. The results are shown in Table 5.

Comparative Examples 1-13
Adhesives and laminates were produced and evaluated in the same manner as in Example 1 except that the types and mixing ratios of Resin A and Resin B were as shown in Tables 6 to 7. The results are shown in Tables 6-7.

In Examples 1-21, the polyester resin composition excellent in transparency and heat resistance was able to be obtained. The adhesive obtained from the polyester resin composition was excellent in heat resistance and adhesiveness. Furthermore, the laminated body using this adhesive was also excellent in transparency.

  In particular, blending using different polyalkylene glycols in resin A and resin B as in Example 1 and Example 6 is compared to blending using the same polyalkylene glycol in resin A and resin B as in Example 20. The compatibility was improved, and the transparency of the adhesive and the transparency of the laminate could be improved.

In Comparative Example 1, since the resin (A-8) did not show the crystallinity because the melting point Tm and the heat of fusion Q were not detected, the softening point Ts of the adhesive was lowered and the heat resistance was lowered.
In Comparative Example 2, since the blending amount of the resin (A-1) was small, the crystallinity was insufficient, the softening point Ts of the adhesive was lowered, and the heat resistance was lowered.

  In Comparative Example 3, since the resin (A-9) contained no polyalkylene glycol, the compatibility of the resin composition comprising (A-9) and (B-1) was poor, and the solution was turbid. did. Therefore, the adhesiveness and heat resistance as an adhesive agent could not be measured.

  In Comparative Example 4, since 1,4-cyclohexanedimethanol was not contained in the resin (A-10), it was not dissolved in the organic solvent at a solid content concentration of 30% by mass. Accordingly, the solution of the resin composition is also turbid, and the adhesiveness and heat resistance as an adhesive cannot be measured.

  In Comparative Example 5, since the polyalkylene glycol content relative to the resin (B-8) was too small, the glass transition temperature Tg was high, and the phase of the resin composition consisting of (A-1) and (B-8) The solubility was poor and the resin composition solution separated into two layers. Therefore, the adhesiveness and heat resistance as an adhesive agent could not be measured.

  In Comparative Example 6, since the resin (B-9) does not contain polyalkylene glycol, the compatibility of the resin composition comprising (A-5) and (B-6) is poor, and the solution is turbid. did. Therefore, the adhesiveness and heat resistance as an adhesive agent could not be measured.

  In Comparative Example 7, since the resin (A-11) does not contain polyalkylene glycol, the glass transition temperature Tg increases, and the adhesiveness of the adhesive composed of (A-11) and (B-1) decreases. did.

  In Comparative Example 8, the resin (A-12) did not contain terephthalic acid and adipic acid, the melting point Tm and the heat of fusion Q were not detected, and the crystallinity was not exhibited. Therefore, the softening point Ts of the adhesive composed of (A-12) and (B-1) was lowered, and the heat resistance was lowered.

In Comparative Example 9, the softening point of the adhesive composed of the resins (A-13) and (B-1) was lowered, and the heat resistance was lowered.
In Comparative Example 10, the resin (A-15) did not contain terephthalic acid, the melting point Tm and the heat of fusion Q were not detected, and the crystallinity was not exhibited. Therefore, the softening point Ts of the adhesive composed of (A-15) and (B-1) was lowered, and the heat resistance was lowered.

  In Comparative Example 11, the resin (A-16) did not contain adipic acid, the melting point Tm and the heat of fusion Q were not detected, and the crystallinity was not exhibited. Therefore, the softening point Ts of the adhesive composed of (A-16) and (B-1) was lowered, and the heat resistance was lowered.

In Comparative Example 12, since the polyalkylene glycol blended in the resin (A-17) was excessive, the glass transition temperature Tg was greatly decreased, and the adhesiveness and heat resistance were decreased.
In Comparative Example 13, since the polyalkylene glycol blended in the resin (B-11) was excessive, the glass transition temperature Tg was greatly decreased, and the adhesiveness and heat resistance were decreased.

Claims (9)

A polyester resin composition comprising a crystalline polyester resin (A) and an amorphous polyester resin (B), which simultaneously satisfies the following (i) to (v):
(I) The glass transition temperature of the crystalline polyester resin (A) is less than 30 ° C, and the glass transition temperature of the amorphous polyester resin (B) is less than 40 ° C.
(Ii) The mixing ratio of the crystalline polyester resin (A) and the amorphous polyester resin (B) is (A) / (B) = 20/80 to 98/2 in terms of mass ratio.
(Iii) Each of the crystalline polyester resin (A) and the amorphous polyester resin (B) contains 2 to 50 mol% of polyalkylene glycol.
(Iv) The crystalline polyester resin (A) contains 50 to 70 mol% of terephthalic acid and 30 mol% of adipic acid as acid components.
(V) 1,4-butanediol as a glycol component in the crystalline polyester resin (A) is 25 to 49 mol% and 1,4-cyclohexane dimethanol is contained 25 to 49 mol%.   The polyester resin composition according to claim 1, wherein the heat of fusion Q measured using a differential scanning calorimeter in accordance with JIS K 7121 is 0.2 to 10 J / g.   The polyester resin composition according to claim 1 or 2, wherein the polyalkylene glycols contained in the crystalline polyester resin (A) and the amorphous polyester resin (B) are different polyalkylene glycols.   The solid content concentration of the crystalline polyester resin (A) and the amorphous polyester resin (B) when the crystalline polyester resin (A) and the amorphous polyester resin (B) are dissolved in a mixed solution of toluene and methyl ethyl ketone. Total is 5-50 mass%, The polyester resin composition in any one of Claims 1-3 characterized by the above-mentioned.   The crystalline polyester resin (A) and the amorphous polyester resin (B) are mixed with toluene so that the total solid content concentration of the crystalline polyester resin (A) and the amorphous polyester resin (B) is 50% by mass. 5. The polyester resin composition according to claim 1, wherein the total light transmittance of a solution dissolved in a mixed solution of methyl ethyl ketone is 90% or more.   An adhesive comprising a polyester resin composition and an organic solvent, the adhesive comprising the polyester resin composition according to any one of claims 1 to 5 and an organic solvent.   The laminated body which consists of a resin layer and base material using the adhesive agent of Claim 6.   The laminate according to claim 7, wherein the resin layer is laminated in two or more layers.   The laminate according to claim 7 or 8, which is used for a flexible flat cable.