JP2017214454A - Resin composition for adhesive, adhesive and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for an adhesive which is excellent in adhesiveness to a polyester film and metal, can be suitably used for application of a flexible flat cable used for internal wiring of electronic equipment, and is excellent in heat resistance and solution stability to a general-purpose solvent, and an adhesive using the composition.SOLUTION: The resin composition for an adhesive is provided which contains two kinds of crystalline polyester resins having different number average molecular weights, and in which a ratio [(A)/(B)] of a crystalline polyester resin (A) to a crystalline polyester resin (B) is 1.1-1.5, the crystalline polyester resin (A) contains 35-55 mol% of 1,4-cyclohexanedimethanol as a glycol component and has a melting point of 110-150°C, and the crystalline polyester resin (B) contains 40-70 mol% of 1,4-cyclohexanedimethanol as a glycol component, has a melting point of 130-180°C, and further contains a curing agent.SELECTED DRAWING: None

Description

The present invention has excellent adhesion to polyester films and metals, and can be suitably used for flexible flat cable applications used for internal wiring of electronic equipment, etc., heat resistance and solution stability against general-purpose solvents It is related with the resin composition for adhesives excellent in.

Up to now, a flexible flat cable (hereinafter sometimes abbreviated as FFC) in which a plurality of conductors having a flat cross section are covered with an electrically insulating synthetic resin film from both sides in an internal wiring or the like of an electronic device. Widely used, the wiring work is made more efficient.

A polyester film has been conventionally used as the electrically insulating synthetic resin film constituting such FFC, and as an adhesive for bonding the electrically insulating synthetic resin film and the conductor, an insulating material is used. Polyester resins are used from the viewpoints of durability and durability, and adhesion to an electrically insulating synthetic resin film as a base material.

However, the polyester resin that has been used as an adhesive layer has a low heat-resistant temperature, so it is easily deformed when placed in a high-temperature atmosphere or when high and low temperatures are repeated. Peeling occurs between the resin film or the conductor, or the polyester resin is thermally deformed at the end of the flat cable, resulting in poor contact with the connector.

As a method for solving this problem, it is conceivable to make the polyester resin difficult to be thermally deformed by using a crystalline resin. For example, it is considered effective to use a polyester resin having crystallinity described in Patent Document 1 as such a resin. However, although the polyester resin described in Patent Document 1 has good heat resistance, it is inferior in solution stability such as becoming cloudy or increasing in solution viscosity after being dissolved in a general-purpose solvent.

Moreover, as a method for improving the heat resistance of the crystalline polyester resin, there is a method of copolymerizing 55 to 80 mol% of 1,4-cyclohexanedimethanol as a glycol component as described in Patent Document 2. However, such a polyester resin is hardly soluble in an organic solvent, and the solid content concentration must be lowered to about 15% by mass, and the solubility is not sufficient.

JP-A-6-240204 JP 2014-74172 A

The present invention solves the above-described problems, has excellent adhesion to polyester films and metals, and can be suitably used for flexible flat cable applications such as internal wiring of electronic equipment, and is heat resistant. It is an object of the present invention to provide a resin composition for an adhesive excellent in solution stability against a general-purpose solvent and an adhesive using the composition.

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 the following (1) to (3).
(1) A resin composition for an adhesive containing two types of crystalline polyester resins having different number average molecular weights, wherein the ratio of the number average molecular weights of the crystalline polyester resin (A) and the crystalline polyester resin (B) [ (A) / (B)] is 1.1 to 1.5, and the crystalline polyester resin (A) contains 35 to 55 mol% of 1,4-cyclohexanedimethanol as a glycol component and has a melting point of 110. -150 ° C, the crystalline polyester resin (B) contains 40-70 mol% of 1,4-cyclohexanedimethanol as a glycol component and has a melting point of 130 ° C-180 ° C. Resin composition.
(2) An adhesive comprising the resin composition for an adhesive according to (1) in an organic solvent.
(3) A laminate comprising an adhesive layer containing the resin composition for an adhesive according to (1) and an insulating film having a laminated structure.

The resin composition for adhesives of the present invention uses two types of crystalline polyester resins having different number average molecular weights, and the two types of crystalline polyester resins have a specific composition, and thus have excellent heat resistance. It is excellent in solubility in a solvent and solution stability, and further excellent in adhesion to a polyester film and a metal.
For this reason, the FFC using the resin composition for adhesives of the present invention as an adhesive layer is less likely to cause problems such as peeling and poor contact even when used in a high temperature atmosphere.

Hereinafter, the present invention will be described in detail.
The resin composition for adhesives of the present invention contains two types of crystalline polyester resins having different number average molecular weights.
The resin having the larger number average molecular weight is referred to as crystalline polyester resin (A), and the resin having the smaller number average molecular weight is referred to as crystalline polyester resin (B). And it is important that ratio [(A) / (B)] of number average molecular weight of both resin is 1.1-1.5. When the ratio of the number average molecular weight is smaller than 1.1, the solution stability when dissolved in a solvent is lowered. On the other hand, when the ratio of the number average molecular weight exceeds 1.5, the heat resistance and the adhesive strength are lowered.

The number average molecular weight of the crystalline polyester resin (A) is preferably 18000 to 23000. When the number average molecular weight of the crystalline polyester resin (A) is smaller than 18000, the heat resistance and adhesive strength are lowered, and when it exceeds 23,000, the solution stability when dissolved in a solvent is lowered, which is not preferable.

The number average molecular weight of the crystalline polyester resin (B) is preferably 14,000 to 19000. When the number average molecular weight of the crystalline polyester resin (B) is smaller than 14,000, the heat resistance and the adhesive strength are lowered, and when it exceeds 19000, the solution stability when dissolved in the solvent is lowered, which is not preferable.

The crystalline polyester resin (A) contains 35 to 55 mol% of 1,4-cyclohexanedimethanol as the glycol component, when the total amount of all glycol components is 100 mol%, and particularly 35 to 45 mol%. It is preferable to contain. When the content of 1,4-cyclohexanedimethanol is less than 35 mol%, the crystallinity of the resin is lowered and the heat resistance is lowered. On the other hand, when the content of 1,4-cyclohexanedimethanol exceeds 55 mol%, the solubility in a solvent and the solution stability are lowered, which is not preferable.

Next, the crystalline polyester resin (B) contains 40 to 70 mol% of 1,4-cyclohexanedimethanol, when the total amount of all glycol components is 100 mol%, more than 45 mol%, It is preferable to contain 70 mol% or less. When the content of 1,4-cyclohexanedimethanol is less than 40 mol%, the crystallinity of the resin is lowered and the heat resistance is lowered. On the other hand, when the content of 1,4-cyclohexanedimethanol exceeds 70 mol%, the solubility in a solvent and the solution stability are lowered, which is not preferable.

The crystalline polyester resin (B) preferably has a higher content of 1,4-cyclohexanedimethanol than the crystalline polyester resin (A). The crystalline polyester resin (A) and the crystalline polyester resin (B ) Content of 1,4-cyclohexanedimethanol [(B) / (A)] is preferably 1.1 to 2.0.
When the content ratio [(B) / (A)] is smaller than 1.1, the heat resistance of the obtained resin composition for an adhesive tends to be lowered. On the other hand, when the content ratio [(B) / (A)] exceeds 2.0, solubility in a solvent, solution stability, and adhesive strength are lowered, which is not preferable.

Examples of glycol components other than 1,4-cyclohexanedimethanol in the crystalline polyester resins (A) and (B) include ethylene glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3- Aliphatic glycols exemplified by propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, polyethylene glycol, polytrimethylene glycol, and the like, Hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, bisphenol A, 2,5-naphthalenediol, and glycols obtained by adding ethylene oxide to these glycols. Aromatic glycols can be used. Examples of the polyhydric alcohol other than glycol include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, hexanetriol and the like.

Examples of the acid component in the crystalline polyester resins (A) and (B) include terephthalic acid, isophthalic acid, 5- (alkali metal) sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, Aromatic dicarboxylic acids or their ester-forming derivatives exemplified by succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1, A saturated aliphatic dicarboxylic acid exemplified by 4-cyclohexanedicarboxylic acid or the like, or an ester-forming derivative thereof; an unsaturated aliphatic dicarboxylic acid exemplified by fumaric acid, maleic acid, itaconic acid, or the like; or an ester-forming derivative thereof. Can be mentioned. Examples of polyvalent carboxylic acids other than dicarboxylic acids include butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3 ′, 4′-biphenyltetracarboxylic acid, and ester-forming derivatives thereof. Can be mentioned.

In the present invention, the crystalline polyester resin is a polyester resin in which a melting point peak is observed by differential scanning calorimetry (20 ° C./min).

The melting point of the crystalline polyester resin (A) is 110 ° C to 150 ° C. When the melting point of the resin is less than 110 ° C., the solubility is good, but the heat resistance is lowered. On the other hand, when the melting point of the resin exceeds 150 ° C., the heat resistance is improved, but the solubility in a solvent and the solution stability are greatly reduced.

The melting point of the crystalline polyester resin (B) is 130 ° C to 170 ° C. When the melting point of the resin is less than 130 ° C., the solubility is good, but the heat resistance is lowered. On the other hand, when the melting point of the resin exceeds 170 ° C., the heat resistance is improved, but the solubility in a solvent and the solution stability are greatly reduced.

The glass transition temperature of the crystalline polyester resin (A) and the crystalline polyester resin (B) of the present invention is preferably −20 ° C. to 30 ° C., and particularly preferably −10 ° C. to 20 ° C. . When the glass transition temperature is less than −20 ° C., the elastic modulus at a high temperature is lowered, and the adhesive force may be insufficient. On the other hand, when the glass transition temperature exceeds 30 ° C., the elastic modulus near room temperature becomes high, the resin itself becomes too hard, and the adhesiveness may not be exhibited with respect to the adherend.

  The mass ratio (A / B) of the crystalline polyester resin (A) and the crystalline polyester resin (B) in the resin composition for an adhesive of the present invention is preferably 90/10 to 40/60, and in particular, 85. / 15 to 60/40 is preferable. Outside this range, it is difficult to achieve the effects of the present invention.

In the resin composition for an adhesive of the present invention, it is preferable to blend an amorphous polyester resin in addition to the two types of crystalline polyester resins (A) and (B). Since the crystalline polyester resin has crystallinity, volume shrinkage may occur during the crystallization process when forming the adhesive layer, and the adhesive force may be reduced. By blending an amorphous polyester resin, volume shrinkage due to such a crystalline polyester resin can be relaxed, and a decrease in adhesive strength can be prevented.

The amorphous polyester resin in the present invention preferably has a glass transition temperature of 10 ° C to 100 ° C, and more preferably 40 ° C to 90 ° C. If the glass transition temperature is less than 10 ° C., the blocking resistance of the resulting adhesive resin composition tends to be reduced. On the other hand, if the glass transition temperature exceeds 100 ° C., the effect of preventing the decrease in adhesive strength as described above is exhibited. It becomes difficult.

It is preferable that content of an amorphous polyester resin is 10-40 mass parts with respect to 100 mass parts of polyester resins (A). When the content of the amorphous polyester resin is less than 10 parts by mass, the volume shrinkage due to the crystalline polyester resin is alleviated and the effect of preventing the decrease in adhesive force is poor. On the other hand, when content of an amorphous polyester resin exceeds 40 mass parts, it exists in the tendency for the heat resistance of the resin composition for adhesive agents obtained to fall.

Furthermore, the resin composition for an adhesive of the present invention preferably contains a curing agent in order to improve adhesiveness by crosslinking and chain extending the crystalline polyester resins (A) and (B). .

It is preferable that content of a hardening | curing agent is 0.5-5 mass% in the resin composition for adhesive agents. When the content of the curing agent is less than 0.5% by mass, the crystalline polyester resins (A) and (B) as described above cannot be cross-linked and chain-extended, thereby improving the adhesiveness. It will be scarce. On the other hand, when content of a hardening | curing agent exceeds 5 mass%, it exists in the tendency for the solution stability of the resin composition for adhesive agents obtained to fall.

Here, it is preferable to use an isocyanate compound as the curing agent. Examples of the isocyanate compound include 2,4- or 2,6-tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2, Of an isocyanate compound selected from 4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, etc. Adducts comprising the above isocyanate compounds selected from a single substance or at least one kind, DOO body, can be used isocyanurate.

For example, in the crystalline polyester resin of the present invention dissolved in an organic solvent, the hydroxyl terminal in the resin reacts with the isocyanate group in the curing agent to increase the molecular weight, thereby improving the adhesive force and heat resistance.

The crystalline polyester resins (A) and (B) of the present invention can be produced by a conventionally known polyester production method. For example, using an acid component and a glycol component as described above as raw materials and performing an esterification or transesterification reaction at a temperature of 220 to 280 ° C. by a conventional method, a polycondensation catalyst is added, and the pressure is reduced to 5 hPa or less. It can be obtained by performing a polycondensation reaction at a temperature of 230 to 280 ° C, preferably 240 to 260 ° C. Furthermore, depending on the purpose and application, it can also be obtained by a method in which an acid component or a glycol component is added to a polymer obtained by a polycondensation reaction and a depolymerization reaction is performed at a temperature of 220 to 280 ° C.

The resin composition for an adhesive of the present invention is a heat stabilizer such as phosphoric acid, an antioxidant such as a hindered phenol compound, talc, silica, etc., as necessary and within a range not impairing the effects of the present invention. In the present invention, conventionally known additives such as a crystal nucleating agent, a lubricant, a pigment such as titanium oxide, a filler, an antistatic agent, and a foaming agent may be contained.

Next, the adhesive of the present invention will be described. The adhesive of the present invention contains the resin composition for an adhesive of the present invention in an organic solvent. The organic solvent is not particularly limited as long as it dissolves the crystalline polyester resin of the present invention. Specifically, aromatic solvents such as benzene, toluene, xylene, methylene chloride, chloroform, Chlorine solvents such as carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, dichlorobenzene, ester solvents such as ethyl acetate, isophorone, γ-butyrolactone, acetone, methyl ethyl ketone Ketone solvents such as methyl isobutyl ketone and cyclohexanone, ether solvents such as diethyl ether, ethyl cellosolve, butyl cellosolve, tetrahydrofuran and 1,4-dioxane, methanol, ethanol, n-propanol, isopropanol, n-butanol, etc. Alcohol-based dissolution N-butane, isobutane, n-pentane, n-hexane, n-heptane, n-octane, nonane and other aliphatic hydrocarbon solvents, cyclopentane, cyclohexane and other alicyclic hydrocarbon solvents, etc. And may be used alone or in combination.

The content (concentration) of the resin composition for an adhesive of the present invention in the adhesive of the present invention is preferably 10 to 40% by mass, and more preferably 20 to 30% by mass. When the density | concentration of the resin composition for adhesive agents is higher than 40 mass%, the solution stability of an adhesive agent will worsen. On the other hand, when the concentration is less than 10% by mass, it is necessary to increase the coating amount and the number of coatings of the adhesive when increasing the thickness of the adhesive layer, resulting in poor working efficiency and low productivity.

Further, when the crystalline polyester resin is dissolved in the above-described solvent, in order to impart flame retardancy, brominated flame retardants, metal hydroxides, metal oxides such as antimony trioxide, phosphates, borates, Metal sulfides, ammonium salts, organic nitrogen flame retardants, silicon flame retardants, phosphorus flame retardants and the like may be blended.

The adhesive of the present invention is excellent in adhesion to polyester films, sheets and metal foils. The adhesive of the present invention is applied between these adherends, and the resin composition for adhesive of the present invention. An adhesive layer made of is formed. And it can be set as a laminated body by a conventionally well-known method, such as heat sealing, roll adhesion, and thermocompression bonding.

Next, the laminated body of this invention is demonstrated. The laminate of the present invention is formed by laminating an adhesive layer containing the resin composition for an adhesive of the present invention and an insulating film. As other layers constituting the laminate, a plastic film or a metal foil is used, and as the plastic, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyarylate, Polyamide, polyolefin, polyethersulfone, polysulfone, polystyrene, methacryl, etc. can be mentioned, and examples of metals include copper, iron, aluminum, tinplate, etc. Examples thereof include plating products such as tin and zinc, and chemical conversion treatment products such as zinc phosphate and chromate.

The method for forming the adhesive layer containing the resin composition for an adhesive of the present invention may be performed by any method, but there is a method in which the adhesive of the present invention described above is applied onto an insulating film and then the solvent is removed. Is preferred.

Hereinafter, the present invention will be described specifically by way of examples. The measurement and evaluation methods for each characteristic value in the examples were performed as follows.
(1) Composition of crystalline polyester resin 1H-NMR was measured with an LA-400 NMR apparatus manufactured by JEOL Ltd., and was determined from the peak integrated intensity ratio of protons of each copolymer component in the obtained chart.
(2) The number average molecular weight was determined in terms of polystyrene by GPC analysis using a number average molecular weight feeding unit (Waters 2695, manufactured by Waters) and a PDA detector (Waters 2996, manufactured by Waters). Moreover, chloroform / hexafluoroisopropanol = 95/5 was used as a solvent.

(3) Measurement of glass transition point (Tg) and melting point (Tm) Using a differential scanning calorimeter (Diamond DSC) manufactured by PerkinElmer, the glass transition point (Tg) was measured at a heating rate of 20 ° C./min.
(4) Softening point of resin Using TMA-60 manufactured by Shimadzu Corporation, measurement was performed at an indenter of 0.5 mm in diameter, a weight of 50 g, and a heating rate of 5 ° C./min.

(5) Heat resistance (softening point of adhesive layer)
The obtained adhesive was coated on a copper foil (thickness 30 μm) so that the adhesive layer was 30 μm, then dried at 100 ° C. for 5 minutes, and further treated at 50 ° C. for 24 hours to obtain an adhesive sheet It was created. Using the TMA-60 manufactured by Shimadzu Corporation, the obtained adhesive sheet was measured for the softening point of the adhesive layer with an indenter of 0.5 mm in diameter, a weight of 50 g, and a heating rate of 5 ° C./min.

(6) Solution stability The solution viscosity of the obtained adhesive was measured using a B-type rotational viscometer, and the stability was evaluated by the change over time. After adjustment, the viscosity of the solution of the adhesive when allowed to stand for 1 hour was set to 1 immediately after dissolution. Thereafter, the adhesive was stored hermetically at 23 ° C. for 7 days, and the solution viscosity 2 of the adhesive was similarly measured using a B-type rotational viscometer. The ratio of viscosity 2 to viscosity 1 immediately after dissolution was evaluated in three stages according to the following criteria.
○: Viscosity 2 is 1.0 times or more and less than 1.3 times viscosity 1
Δ: Viscosity 2 is 1.3 times or more and less than 1.5 times viscosity 1 ×: Viscosity 2 is 1.5 times or more and less than 2.0 times viscosity 1

(7) Peel adhesion A (to metal)
After applying an adhesive on a copper foil (thickness 30 μm) so that the adhesive layer was 30 μm, it was dried at 100 ° C. for 5 minutes and further treated at 50 ° C. for 24 hours to produce an adhesive sheet. . A copper foil similar to this was bonded using a laminator (SA-1010) manufactured by Tester Sangyo Co., Ltd. under the conditions of a temperature of 170 ° C., a linear pressure of 40 N / cm, and a speed of 0.75 m / min. The bonded material was cut to a width of 25 mm, and tested using an autograph AG-2 manufactured by Shimadzu Corporation under a 23 ° C. atmosphere at a tensile speed of 50 mm / min, and the T-type peel adhesion was measured. .

(8) Peel adhesion B (for polyester)
An adhesive was applied on a polyethylene terephthalate film (thickness 35 μm) so that the adhesive layer was 30 μm, and then dried at 100 ° C. for 5 minutes to prepare an adhesive sheet. The same polyethylene terephthalate film was bonded to this under the conditions of a temperature of 170 ° C., a linear pressure of 40 N / cm, and a speed of 0.75 m / min using a laminator (SA-1010) manufactured by Tester Sangyo Co., Ltd. The bonded material was cut to a width of 25 mm, and tested using an autograph AG-II manufactured by Shimadzu Corporation under a 23 ° C. atmosphere at a tensile speed of 50 mm / min, and the T-type peel adhesion was measured. .

[Production of Crystalline Polyester Resin (A-1)]
In the esterification reactor, 84.0 parts by mass of polybutylene terephthalate, 57.4 parts by mass of terephthalic acid, 26.58 parts by mass of adipic acid, and 60.3 parts by mass of 1,4-cyclohexanedimethanol as a glycol component Then, triethylene glycol was charged in an amount of 57.3 parts by mass, and the esterification reaction was performed at a pressure of 0.5 MPa and a temperature of 250 ° C. for 4 hours.
After the obtained esterified product was transferred to a polycondensation reaction tank, 0.07 parts by mass of tetrabutyl titanate was added as a polycondensation catalyst. Next, the pressure in the reaction system is gradually reduced to 0.4 hPa in 60 minutes, and a polycondensation reaction is performed at 260 ° C. for 3 hours to obtain a crystalline polyester resin (A-1) having a number average molecular weight of 19000 and a melting point of 148.3 ° C. )

[Production of Crystalline Polyester Resins (A-2) to (A-4)]
A polyester resin was obtained in the same manner as in Example 1 except that the amount of components charged into the esterification reactor was changed so as to obtain a polyester resin having the composition shown in Table 1.

[Production of Crystalline Polyester Resins (B-1) to (B-7)]
A polyester resin was obtained in the same manner as in Example 1 except that the amount of components charged into the esterification reactor was changed so as to obtain a polyester resin having the composition shown in Table 1.

[Production of crystalline polyester resin (X-1)]
A polyester resin was obtained in the same manner as in Example 1 except that the amount of components charged into the esterification reactor was changed so as to obtain a polyester resin having the composition shown in Table 1.

Table 1 shows the compositions and characteristic values of the crystalline polyester resins (A-1) to (A-4), (B-1) to (B-7), and (X-1).

Example 1
13 parts by mass of the crystalline polyester resin (A-1), 3 parts by mass of the crystalline polyester resin (B-1), and an amorphous polyester resin manufactured by Unitika Ltd. [Elitel (UE-3600), Tg = 75 ° C. )] 4 parts by weight, dichloromethane 48 parts by weight, toluene 9.6 parts by weight, methyl ethyl ketone 2.4 parts by weight into a 100 mL mayonnaise bottle containing 2 mm diameter glass beads and sealed with a metal cap And completely dissolved in a rocking mill for 1 hour.
Next, to 80 parts by mass of the above solution, 10 parts by mass of bis (pentabromophenyl) ethane (SAYTEX 8010 manufactured by Albemarle) as a flame retardant, 7.2 parts by mass of antimony trioxide, 2 parts by mass of titanium oxide, silica [ Aerosil R972 manufactured by Nippon Aerosil Co., Ltd. was charged in an amount of 0.8 part by mass and dispersed with a rocking mill for 1 hour.
Furthermore, as a curing agent, 2,4-tolylene diisocyanate (manufactured by Kanto Chemical Co., Inc.) was added to the above solution in an amount of 0.16 parts by mass, and after stirring and mixing for 30 minutes with a rocking mill, an adhesive was obtained.

Examples 2-5, Comparative Examples 1-4
An adhesive was obtained in the same manner as in Example 1 except that the crystalline polyester resin (B) shown in Table 2 was used.

Example 6 and Comparative Example 5
An adhesive was obtained in the same manner as in Example 1 except that the crystalline polyester resins (A) and (B) shown in Table 2 were used.

Comparative Example 6
An adhesive was obtained in the same manner as in Example 1 except that 16 parts by mass of the crystalline polyester resin (A-1) was used without using the crystalline polyester resin (B).

Comparative Example 7
An adhesive was obtained in the same manner as in Example 1 except that 16 parts by mass of the crystalline polyester resin (B-1) was used without using the crystalline polyester resin (A).

Table 2 shows the compositions, characteristic values, and evaluation results of the adhesive compositions and adhesives obtained in Examples 1 to 6 and Comparative Examples 1 to 7.

As is apparent from Table 2, the adhesives containing the adhesive resin compositions obtained in Examples 1 to 6 have good solution stability, excellent heat resistance, and adhesion to polyester and metal. It was excellent.

On the other hand, since the resin composition for an adhesive of Comparative Example 1 uses two types of crystalline polyester resins (A), the obtained adhesive has a low softening point of the adhesive layer and is inferior in heat resistance. It was also inferior in peeling adhesive strength B. Since the resin composition for an adhesive of Comparative Example 2 was blended with a crystalline polyester resin (X-1) having a high content of 1,4-cyclohexanedimethanol, the obtained adhesive was inferior in solution stability. In addition, it becomes difficult to form an adhesive layer, and it is impossible to measure the softening point of the adhesive layer and to evaluate the adhesiveness. The resin composition for an adhesive of Comparative Example 3 was blended with a crystalline polyester resin (B) having a large number average molecular weight, and the ratio of the number average molecular weight of the crystalline polyester resin was too small. The solution stability was inferior.

The resin composition for an adhesive of Comparative Example 4 was blended with a crystalline polyester resin (B) having a small number average molecular weight, and the ratio of the number average molecular weight of the crystalline polyester resin was too large. It was inferior in heat resistance. The resin composition for an adhesive of Comparative Example 5 was blended with a crystalline polyester resin (A) having a large number average molecular weight and poor solubility, and the ratio of the number average molecular weight of the crystalline polyester resin was too large. It became inferior in property, and an adhesive could not be obtained.
Since the resin composition for an adhesive of Comparative Example 6 used only the crystalline polyester resin (A), the obtained adhesive had a low softening point of the adhesive layer and was inferior in heat resistance. It was. Since the resin composition for adhesives of Comparative Example 7 used only the crystalline polyester resin (B), the obtained adhesive was inferior in adhesive strength.

Claims (6)

A resin composition for an adhesive containing two types of crystalline polyester resins having different number average molecular weights, wherein the ratio of the number average molecular weights of the crystalline polyester resin (A) and the crystalline polyester resin (B) [(A) / (B)] is 1.1 to 1.5, the crystalline polyester resin (A) contains 35 to 55 mol% of 1,4-cyclohexanedimethanol as a glycol component, and has a melting point of 110 to 150 ° C. The crystalline polyester resin (B) contains 40 to 70 mol% of 1,4-cyclohexanedimethanol as a glycol component and has a melting point of 130 ° C to 180 ° C. object. The resin composition for adhesives according to claim 1, wherein the crystalline polyester resin (A) has a number average molecular weight of 18,000 to 23,000, and the crystalline polyester resin (B) has a number average molecular weight of 14,000 to 19000. The ratio of the content of 1,4-cyclohexanedimethanol in the glycol component of the crystalline polyester resin (A) and the crystalline polyester resin (B) [(B) / (A)] is 1.1 to 2.0. The resin composition for adhesives according to claim 1 or 2. Furthermore, the resin composition for adhesive agents in any one of Claims 1-3 containing a hardening | curing agent. An adhesive comprising the resin composition for an adhesive according to any one of claims 1 to 4 in an organic solvent. The laminated body characterized by the adhesive layer and insulating film containing the resin composition for adhesives in any one of Claims 1-4 having a laminated structure.