JP5340100B2 - 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 acid and glycol that are the constituent components specific, it is possible to obtain a copolyester resin having various characteristics, and the copolyester resin includes an adhesive, a coating agent, Widely used in ink binders and paints. 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 heat resistance and transparency, 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 40 ° C or higher.
(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) The crystalline polyester resin (A) contains 0.5 to 10 mol% of an aliphatic polyhydric alcohol having a side chain.
(Iv) 10-80 mol% of 1,2-propylene glycol is contained in the amorphous polyester resin (B).
(V) The crystalline polyester resin (A) contains 40 to 70 mol% of terephthalic acid and 10 to 50 mol% of adipic acid as acid components.
(Vi) The crystalline polyester resin (A) contains 20 to 70 mol% of 1,4-butanediol and 20 to 60 mol% of 1,4-cyclohexanedimethanol as glycol components.
(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) 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 (1) or (2), wherein the total concentration is 5 to 50% by mass.
(4) Crystalline polyester resin (A) and amorphous polyester resin (B) so that the total solid concentration of the crystalline polyester resin (A) and amorphous polyester resin (B) is 50% by mass. The polyester resin composition according to any one of (1) to (3), wherein the total light transmittance of a solution obtained by dissolving the lysate in a mixed solution of toluene and methyl ethyl ketone is 85% or more.
(5) An adhesive comprising a polyester resin composition and an organic solvent, the adhesive comprising the polyester resin composition according to any one of (1) to (4) and an organic solvent.
(6) A laminate comprising a resin layer and a substrate using the adhesive of (5).
(7) The laminate according to (6), wherein two or more resin layers are laminated.
(8) The laminate according to (6) or (7), 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. The lower limit of the glass transition temperature is preferably −50 ° C., more preferably −30 ° C. 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 when the DSC (differential scanning calorimeter) is used according to JIS K 7121, and the heat of fusion Q is 0.1 J / It shows that it is more than g. 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 40 mol% or more, preferably 50 mol% or more, and more preferably 60 mol% or more. Moreover, the content rate of the terephthalic acid in the resin A needs to be 70 mol% or less.
The content of adipic acid in resin A, from the viewpoint of crystallinity of the promotion, it is necessary to blend with 10 to 50 mol%, favorable preferable be formulated in 20 to 40 mole%.

  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.

The content of 1,4-butanediol in the resin A is, from the viewpoint of improving the solubility, it is necessary to blend 20-70 mol%, favorable preferable be formulated 30-60 mol%.
The content of 1,4-cyclohexanedimethanol in the resin A is, from the viewpoint of improving the solubility, it is necessary that 20 to 60 mol%, it is good preferable from 30 to 50 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 naphthalenedicarboxylic 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 Glycol component such as ethylene oxide adduct of S; tetrahydrophthalic acid, lactic acid, oxirane, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid Hydroxy 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 Carboxylic 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 Alcohol solvents such as 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. It is done. 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.

  The resin A needs to contain an aliphatic polyhydric alcohol having a side chain. Although the containing form is not specifically limited, It is preferable to contain by block copolymerization. By containing the aliphatic polyhydric alcohol having a side chain in the resin A, it is possible to impart transparency while maintaining the crystallinity and heat resistance of the resin A.

  Examples of the aliphatic polyhydric alcohol having a side chain contained in the resin A include 2-methyl-1,3-propanediol, 2,2′-diethyl-1,3-propanediol, and 2-ethyl-2-methyl. -1,3-propanediol, 2-butyl-2-ethyl-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol and the like. Among these, 2-methyl-1,3-propanediol is preferable from the viewpoint of achieving both crystallinity and transparency when used as an adhesive.

  From the viewpoint of compatibility when the resin A and the resin B are mixed, the number average molecular weight of the aliphatic polyhydric alcohol having a side chain contained in the resin A is preferably 60 to 10,000, more preferably 100 to 5000, Particularly preferred is 150 to less than 2500.

  The content of the aliphatic polyhydric alcohol having a side chain in the resin A needs to be 0.5 to 10 mol%, and preferably 0.8 to 8 mol%. When the content of the aliphatic polyhydric alcohol having a side chain is less than 0.5 mol%, there is a problem that transparency when used as an adhesive is insufficient. Moreover, when content exceeds 10 mol%, since the crystallinity which resin A has will fall, it will be inferior to heat resistance, and the adhesiveness when using resin A as an adhesive agent 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 40 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher. When the glass transition temperature is less than 40 ° C., the resin composition is obtained by mixing with the resin A, which is not preferable because the heat resistance is lowered. Further, the upper limit of the glass transition temperature of the resin B is usually about 85 ° C.

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 1,2-propylene glycol. Although the containing form is not specifically limited, It is preferable to contain by block copolymerization. By including 1,2-propylene 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. it can. Further, since 1,2-propylene glycol is contained in the resin B, the glass transition temperature of the resin B can be controlled to 40 ° C. or higher.

  The content of 1,2-propylene glycol in the resin B needs to be 10 to 80 mol%, preferably 20 to 70 mol%, and more preferably 30 to 60 mol%. When the content ratio of 1,2-propylene glycol is less than 10 mol%, there is no effect of increasing the glass transition temperature of the resin B, and the heat resistance is lowered. Moreover, when the content rate of 1, 2- propylene glycol exceeds 80 mol%, the adhesiveness of the adhesive agent obtained by mixing resin A and resin B will fall.

  In the present invention, from the viewpoint of increasing the compatibility with the resin A, the resin B may contain an aliphatic polyhydric alcohol having a side chain. Examples of the aliphatic polyvalent call having a side chain include 2-methyl-1,3-propanediol, 2,2′-diethyl-1,3-propanediol, and 2-ethyl-2-methyl-1,3-propane. Examples include diol, 2-butyl-2-ethyl-propanediol, 3-methyl-1,5-pentadiol, and neopentyl glycol. 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 polyhydric alcohol having the above side chain can be used alone or in combination of two or more.

  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 plays a role of imparting transparency to the resin composition. Further, since the resin B has a glass transition temperature of 40 ° C. or higher, there is an advantage that even when the resin B is mixed with the resin A, the heat resistance of the resin A is not impaired. Therefore, by mixing the resin A and the resin B, heat resistance can be imparted while maintaining transparency.

  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, the heat resistance is insufficient. On the other hand, when it exceeds 98/2, transparency and adhesiveness as an adhesive are 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 85% or more, and more preferably 90% or more. If it is less than 85%, 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. In the present invention, the transmittance of the resin composition is preferably 90% or more, and more preferably 95% or more.

  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; Curing agents such as uretdiones and 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 based on this 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. The coating method using these coaters can arbitrarily control the thickness of the resin layer. 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 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 (“HazeMeter NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.) is 70% or more, and 80% or more. Is more preferable, and 90% or more is more preferable. In the present invention, when the total light transmittance is 70% or more, it is determined that the laminate has transparency.

  The resin composition of the present invention comprises a crystalline polyester resin (A) composed of terephthalic acid, adipic acid, 1,4-butanediol and 1,4-cyclohexanedimethanol and having a glass transition temperature of less than 30 ° C., and glass Since the amorphous polyester resin (B) having a transition temperature of 40 ° C. or higher is mixed at a specific ratio, it has an advantage of being excellent in transparency and adhesiveness and remarkably excellent in heat resistance. 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 heat resistance and transparency, 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 and polyester resin composition
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”). It was evaluated with.
A: Total light transmittance is 95% or more.
A: The total light transmittance is 85% or more and less than 95%.
X: The total light transmittance is less than 85%.
In the present invention, those having a value of ◯ or more are assumed to be practically usable.

(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 (product name “Embret S-38”, manufactured by Unitika Ltd.) (haze value: 5%) is coated with a bar coater so that the thickness is 30 μm. Then, the laminate was dried at 120 ° C. for 2 minutes, and a resin layer having a thickness of 10 μm after drying was formed. 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) (hereinafter sometimes referred to as 1,4-CHDM)
・ Triethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter sometimes referred to as TEG)
2-methyl-1,3-propanediol (manufactured by Dalian Chemical Industries) (hereinafter sometimes referred to as MPD)
・ 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 IP)
-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)
1,2-propylene glycol (manufactured by Sankyo Chemical Co., Ltd.) (hereinafter sometimes referred to as PG)

Preparation Example of Resin A (A-1)
The above raw materials are put into a reaction vessel equipped with a stirring blade so that TPA is 70 mol%, ADA30 mol%, 1,4-BD34 mol%, 1,4-CHDM35 mol%, TEG30 mol%, MPD1 mol%. While stirring at a rotation speed of 100 rpm, esterification was performed at 250 ° C. for 5 hours under a pressure of 0.25 MPa. After that, it is transferred to a polycondensation can and charged with (tetrabutyl titanate) as a polymerization catalyst. The pressure is gradually reduced to 1.3 hPa over 60 minutes, and the polycondensation reaction at 260 ° C. until the molecular weight reaches 20000. To obtain a polyester resin (A-1). 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-15)
As shown in Table 1, resin A was prepared in the same manner as (A-1) except that the acid component, the type of alcohol component, the mixing ratio of the acid component and alcohol component, and the presence or absence of other copolymer components were changed. did. The evaluation results are shown in Table 1.

Preparation Example of Resin B (B-1)
The above raw materials were put into a reaction vessel equipped with a stirring blade so that TPA was 100 mol%, EG 30 mol%, and PG 80 mol%, and the mixture was stirred at 100 rpm and stirred at 250 ° C. under a pressure of 0.25 MPa. Time esterification was performed. 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 80 ° C. The evaluation results are shown in Table 2.

Preparation examples of resin B (B-2) to (B-8)
As shown in Table 2, resin B was prepared in the same manner as (B-1) except that the acid component, the type of alcohol component, the mixing ratio of the acid component and alcohol component, and the presence or absence of other copolymerization components were changed. did. The evaluation results are shown in Table 2.

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 3, 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 98%. Moreover, Tm of this adhesive was 106 ° C., Q was 3.1 J / g, and Ts was 111 ° 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 total light transmittance was 70%. The evaluation results are shown in Table 3.

Examples 2-18
An adhesive and a laminate were prepared in the same manner as in Example 1 except that the types of the resin A and the resin B and the mixing ratio of the resin A and the resin B were as shown in Tables 3 and 4. It was attached to evaluation. The results are shown in Tables 3 and 4.

Example 19
The types and mixing ratios of Resin A and Resin B were the same as in Example 1, and an adhesive and a laminate were prepared so that the total solid content concentration of Resin A and Resin was 50% by mass, and subjected to evaluation. . The results are shown in Table 4.

Comparative Examples 1-14
An adhesive and a laminate were prepared in the same manner as in Example 1 except that the types of the resin A and the resin B and the mixing ratio of the resin A and the resin B were as shown in Tables 5 and 6. It was attached to evaluation. The results are shown in Tables 5 and 6.

  In Examples 1-19, 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 Comparative Example 1, the resin (B-6) does not contain 1,2-propylene glycol, and the resin composition comprising the resin (A-7) and the resin (B-6) has low crystallinity ( The amount of heat of fusion Q was small), the softening point Ts of the obtained adhesive was lowered, and the heat resistance was lowered.

  In Comparative Example 2, since the amount of 2-methyl-1,3-propanediol, which is an aliphatic polyhydric alcohol having a side chain contained in the resin (A-8), was as large as 15 mol%, the melting point Tm and No heat of fusion Q was detected and no crystallinity was shown. Therefore, the softening point Ts of the adhesive obtained from the resin composition consisting of the resins (A-8) and (B-1) was lowered, and the heat resistance was lowered.

  In Comparative Example 3, since the aliphatic polyhydric alcohol having a side chain was not contained in the resin (A-9), the glass transition temperature Tg was increased, and the resin (A-9) and the resin (B-1) The adhesiveness of the adhesive obtained from the resulting resin composition was lowered.

  In Comparative Example 4, since the resin (B-6) did not contain 1,2-propylene glycol, the glass transition temperature Tg was lowered, and the resin composition consisting of the resin (A-1) and the resin (B-6) The softening point Ts of the adhesive obtained from the product was lowered, and the heat resistance was lowered.

  In Comparative Example 5, since the resin (B-7) did not contain 1,2-propylene glycol, the glass transition temperature Tg was lowered, and the resin composition consisting of the resin (A-1) and the resin (B-7) The compatibility of the product was poor, and the resin composition solution was separated into two layers and was not compatible. Therefore, the adhesiveness and heat resistance as an adhesive agent could not be measured.

  In Comparative Example 6, since the mixing ratio of the resin (A-5) was too small, the adhesive obtained from the resin composition composed of the resin (A-5) and the resin (B-5) had a melting point Tm and Since the heat of fusion Q was not detected and the crystallinity was not exhibited, the softening point Ts was also lowered and the heat resistance was lowered.

  In Comparative Example 7, the resin (A-10) contained no terephthalic acid residue and adipic acid residue, and the melting point Tm and the heat of fusion Q were not detected. The softening point Ts of the adhesive obtained from the resin composition comprising (A-10) and the resin (B-1) was lowered, and the heat resistance was lowered.

  In Comparative Example 8, since 1,4-butanediol was not contained in the resin (A-11), the melting point Tm and the heat of fusion Q were not detected and no crystallinity was shown. Therefore, the softening point Ts of the adhesive obtained from the resin composition consisting of the resin (A-11) and the resin (B-1) was lowered, and the heat resistance was lowered.

  In Comparative Example 9, the resin (A-12) does not contain 1,4-cyclohexanedimethanol, and the resin solid content concentration is 30% by mass in a mixed solvent of toluene and methyl ethyl ketone in a mass ratio of 8: 2. It did not dissolve. Therefore, the adhesiveness and heat resistance as an adhesive agent could not be measured.

  In Comparative Example 10, the resin (A-14) 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-14) and (B-1) was lowered, and the heat resistance was lowered.

  In Comparative Example 11, 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 12, since 1,2-propylene glycol blended in the resin (B-8) was excessive, the glass transition temperature Tg was too high, and an adhesive obtained by mixing the resin A and the resin B was used. Adhesion decreased.

In Comparative Example 13, since the mixing ratio of the resin (A-1) and the resin (B-1) was out of the range, the transparency of the adhesive was good, but the heat resistance was lowered.
In Comparative Example 14, since the mixing ratio of the resin (A-1) and the resin (B-1) was out of the range, the heat resistance was good, but the transparency and the adhesiveness were lowered.

Claims (8)

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 40 ° C or higher.
(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) The crystalline polyester resin (A) contains 0.5 to 10 mol% of an aliphatic polyhydric alcohol having a side chain.
(Iv) 10-80 mol% of 1,2-propylene glycol is contained in the amorphous polyester resin (B).
(V) The crystalline polyester resin (A) contains 40 to 70 mol% of terephthalic acid and 10 to 50 mol% of adipic acid as acid components.
(Vi) The crystalline polyester resin (A) contains 20 to 70 mol% of 1,4-butanediol and 20 to 60 mol% of 1,4-cyclohexanedimethanol as glycol components.   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 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 of Claim 1 or 2 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. The polyester resin composition according to any one of claims 1 to 3, wherein the total light transmittance of a solution dissolved in a mixed solution of methyl ethyl ketone is 85% or more.   It is an adhesive agent containing a polyester resin composition and an organic solvent, Comprising: The adhesive agent characterized by including the polyester resin composition and organic solvent in any one of Claims 1-4.   The laminated body which consists of a resin layer and the base material using the adhesive agent of Claim 5.   The laminate according to claim 6, wherein the resin layer is laminated in two or more layers.   The laminate according to claim 6 or 7, wherein the laminate is used for a flexible flat cable.