JP2002173588A - Polyester resin composition and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin composition having high heat resistance, moisture resistance, etc., and suitable as an adhesive or coating agent, and to provide a laminate by the use of the above resin composition. SOLUTION: This polyester resin composition is obtained by incorporating a compound reactive with the terminal carboxy group in a copolyester resin composed of at least one dicarboxylic acid component and at least one glycol component, having a glass transition temperature of -30 to 40 deg.C and a terminal carboxy group content of <=50 geq/106 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyester resin composition. More specifically, the present invention relates to a polyester resin composition suitable for an adhesive or a coating agent and having excellent storage stability, heat resistance, moisture resistance, and the like, and a laminate using the same.

[0002]

2. Description of the Related Art Polyester resins represented by polyethylene terephthalate and polybutylene terephthalate are:
Utilizing its excellent mechanical strength, thermal stability, hydrophobicity and chemical resistance, it is widely used in various fields as fibers, films, molding materials and the like.

[0003] Copolymerized polyesters having various characteristics can be obtained by introducing other components into the dicarboxylic acid and glycol components, which are constituents thereof, and can be used as adhesives, coating agents, ink binders, and paints. Widely used for etc. Such copolyester resins are generally polyester, polycarbonate,
It is known to have excellent adhesiveness to plastics such as polyvinyl chloride resin or metal foil such as aluminum and copper.

Utilizing these characteristics, copolymerized polyester adhesives are also used in applications such as electronic equipment, automobiles, and building materials. Polyester adhesives having a low glass transition point are preferably used for such applications, but since the glass transition point is low, water resistance and moisture resistance are low, and problems such as a decrease in viscosity over time are likely to occur. Had a problem with its reliability.

On the other hand, as a method for improving the hydrolysis resistance of a polyester, a method in which the amount of carboxyl end groups of the polyester is reduced in advance is known, and a method of adding an epoxy compound (Japanese Patent Publication No. 44-27911, JP-A-54-6051), a method of adding a carbodiimide compound (JP-B-1-15604, JP-A-3-104919, JP-A-4-289221).
And the like have been proposed. However, the method disclosed herein is for polyester fibers,
It is not applicable for adhesives and coatings.

[0006]

SUMMARY OF THE INVENTION The present invention solves various problems of polyesters for adhesives and coatings, is excellent in heat resistance and moisture resistance, and is applicable to metal plates and plastic films or sheets. An object of the present invention is to provide a polyester resin composition having good adhesiveness, and a laminate using the same.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted various studies to solve the above problems, and as a result, have found that a specific compound is added to a copolymerized polyester having a glass transition point and a carboxyl terminal group content within a specific range. As a result, they have found that the above problem can be solved, and have reached the present invention. That is, the present invention (1) comprises one or more dicarboxylic acid components and one or more glycol components, and has a glass transition point of -30.
-40 ° C., the amount of carboxyl end groups is 50 geq / 10 ⁶
A polyester resin composition, characterized in that a compound capable of reacting with a carboxyl end group is contained in a copolymer polyester resin having a weight of not more than g in an amount satisfying the following formula. 0.5 ≦ [X] / [COOH] ≦ 5 (where [X] is the total content of the compound capable of reacting with the carboxyl terminal group in the copolymerized polyester resin (geq / 1
0 ⁶ g), representing the [COOH] is a carboxyl end group amount of copolymerized polyester resin (geq / 10 ⁶ g). (2) (A) a layer of a plastic film or a plastic sheet, (B) a layer of an adhesive made of the polyester resin composition of (1), and (C) a layer of a metal plate. Laminate. (3) The laminate according to (2), wherein the polyester resin composition in the layer (B) has a carboxyl end group content of 25 geq / 10 ⁶ g or less.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyester resin composition of the present invention comprises a copolymerizable polyester resin comprising one or more dicarboxylic acid components and one or more glycol components, and a compound capable of reacting with a carboxyl terminal group.

As the dicarboxylic acid component, terephthalic acid, isophthalic acid, adipic acid and sebacic acid are mainly used from the viewpoint of adhesive properties and cost. Further, if necessary, phthalic acid and its anhydride, aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, azelaic acid, dodecane diacid, eicosane diacid And aliphatic dicarboxylic acids such as dimer acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid, and unsaturated dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid. May be. These dicarboxylic acid components may use derivatives such as dialkyl esters and acid chlorides.
They can be used alone or in combination.

As the glycol component, ethylene glycol and neopentyl glycol are mainly used from the viewpoint of adhesive properties and cost. Also, if necessary,
2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-butyl Aliphatic glycols such as -2-ethyl-1,3-propanediol, diethylene glycol and triethylene glycol;
Alicyclic diols such as 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanediethanol, and ethylene oxide or propylene oxide adducts such as bisphenol S and bisphenol A And polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and spiro glycol. These glycol components can be used alone or in combination.

Furthermore, the following components may be copolymerized as long as the object of the present invention is not impaired. Such components include trimellitic acid, trimesic acid, pyromellitic acid and polycarboxylic acids such as acid anhydrides thereof,
aliphatic lactones such as γ-butyrolactone, ε-caprolactone, δ-valerolactone, 4-oxybenzoic acid,
Oxycarboxylic acids such as-(hydroxyethoxy) benzoic acid and 5-hydroxyisophthalic acid; polyhydric alcohols such as trimethylolpropane, pentaerythritol and glycerin; (10-oxa-9-oxide-9,10-dihydro-9- Phosphaphenanthren-9-yl) methylsuccinic acid, methylphosphorane, phenylphosphorane,
Flame-retardant monomers such as alkyl bis (hydroxyalkyl) phosphine oxide, alkyl bis (carboxylalkyl) phosphine oxide, and ethylene oxide adduct of 2,6,2 ', 6'-tetrabromobisphenol A.

The copolymerized polyester resin used in the polyester resin composition of the present invention has a glass transition point of -30.
４０40 ° C., preferably −2
0-25 ° C. If the glass transition point is lower than -30 ° C, it is not preferable because the handling of the resin is difficult, and the performance as an adhesive, particularly the adhesive strength in a high temperature region (50 to 120 ° C) is lowered. On the other hand, when it exceeds 40 ° C., it is difficult to obtain a high molecular weight copolyester resin, and sufficient adhesive strength cannot be obtained.

The copolymerized polyester resin used in the polyester resin composition of the present invention must have a carboxyl terminal group content of 50 geq / 10 ⁶ g or less.
Preferably it is 30 geq / 10 ⁶ g or less. When the amount of carboxyl end groups exceeds 50 geq / 10 ⁶ g, the molecular weight is significantly reduced due to hydrolysis over time, and even if the following compounds are contained, the effect of improving water resistance and moisture resistance is not sufficient, and As an agent, the adhesive strength tends to decrease, which is not preferable.

Since the carboxyl terminal group promotes hydrolysis of the polyester resin, it is important to block and reduce it. For that purpose, it is necessary that the compound capable of reacting with the carboxyl terminal group in the polyester resin contains an amount satisfying the following formula. 0.5 ≦ [X] / [COOH] ≦ 5 In the formula, [X] is the total content of the compound capable of reacting with the carboxyl terminal group in the copolymerized polyester resin (geq / 10
⁶ g) and [COOH] represent the amount of carboxyl terminal groups (geq / 10 ⁶ g) of the copolymerized polyester resin.

If the ratio of the total content of compounds capable of reacting with carboxyl groups to the amount of carboxyl terminal groups of the polyester resin is less than 0.5, the carboxyl terminal groups are not sufficiently blocked, so that the water resistance of the polyester resin is reduced. sex,
Cannot improve moisture resistance. On the other hand, if it exceeds 5, not only is it difficult to dissolve the compound capable of reacting with the carboxyl terminal group when dissolving the polyester resin composition in the solvent, but also it causes problems such as bleeding when the adhesive layer is formed. There is.

The compound capable of reacting with the carboxyl terminal group is preferably a carbodiimide compound, an oxazoline compound, an epoxy compound, an alkali metal salt, or an alkaline earth metal salt from the viewpoint of adhesive properties and cost. Can be used alone or in combination. Hereinafter, specific examples of the compound capable of reacting with the carboxyl terminal group are shown, but are not particularly limited as long as the object of the present invention can be achieved.

As the carbodiimide compound, N, N '
-(Di-o-tolyl) -carbodiimide, N, N'-
(2,6,2 ′, 6′-tetraisopropyldiphenyl) carbodiimide, N, N′-dicyclopentylcarbodiimide and the like.

Examples of the oxazoline compound include bisoxazoline and phenylbisoxazoline.

Epoxy compounds include butyl glycidyl ether, phenyl glycidyl ether, polyethylene glycol glycidyl ether, bisphenol A
Type, bisphenol F type diglycidyl ether, aliphatic diglycidyl ether and the like.

As the alkali metal compound, lithium glycolate, lithium acetate, sodium glycolate,
Examples include sodium formate, sodium acetate, sodium hypophosphite, potassium glycolate, potassium acetate, potassium hypophosphite and the like. Examples of the alkaline earth metal compound include magnesium acetate, magnesium oxide, magnesium stearate, calcium acetate, magnesium stearate and the like.

Further, if necessary, an isocyanate compound, a hydroxy compound, an amino compound and the like can be contained.

Further, the copolymerized polyester resin used in the present invention preferably has an intrinsic viscosity of 0.2 or more. When the intrinsic viscosity is less than 0.2, the adhesive strength is undesirably low.

The method for producing the copolymerized polyester resin used in the present invention is not particularly limited, and it can be produced by a conventionally known method for producing a polyester resin. For example, the dicarboxylic acid component and the glycol component (including their ester-forming derivatives) as described above are used as raw materials, and 150 to 280 by a conventional method.
After performing esterification or transesterification at a temperature of 200 ° C., a polycondensation catalyst is added, and the pressure is reduced to 200 under a reduced pressure of 5 hPa or less.
It can be prepared by conducting a polycondensation reaction at a temperature of from 300 to 300C, preferably from 230 to 280C. Further, depending on the purpose and application, an acid component and / or a glycol component may be added to the polymer obtained by the polycondensation reaction to form a polymer.
It can also be prepared by a method of performing a depolymerization reaction at a temperature of 0 to 280 ° C.

As a catalyst used in producing the above-mentioned copolymerized polyester resin, a conventionally known metal compound can be used. Specific examples include organic acid salts such as zinc, antimony, germanium, tin, titanium, aluminum, and cobalt, oxides, alkoxides, and alkyl compounds.

When the copolyester is polycondensed, a stabilizer such as triphenyl phosphate, triethyl phosphate, phosphoric acid or the like, or an oxidizing agent such as a hindered phenol compound, a sulfur compound, a phosphite compound or a hindered amine compound is used. An inhibitor, a matting agent such as titanium dioxide, and the like may be added as long as the characteristics of the present invention are not impaired.

Further, the compound capable of reacting with the carboxyl terminal group may be added at any stage from immediately after the completion of the polycondensation reaction of the copolymerized polyester resin until the formation of the laminate.

Next, the laminate of the present invention and a method for producing the same will be described. That is, the laminate of the present invention is composed of a layer (A) of a plastic film or a plastic sheet, a layer (B) of an adhesive made of the polyester resin composition described above, and a layer (C) of a metal plate. It is characterized by the following.

A plastic film is defined by JIS Z-
0108 or less as described in “P.
mm, and the surface thereof may be subjected to a corona treatment or an easy adhesion treatment such as providing an easy adhesion resin layer. The material used for the plastic film or the plastic sheet is preferably polyethylene terephthalate (hereinafter referred to as PET), but is not limited thereto. Chlorine-based resins such as polyvinyl chloride and polyvinylidene chloride, polycarbonate resins, polyarylate resins Polyester resins such as polybutylene terephthalate and polyethylene naphthalate, polyether sulfone resins, polysulfone resins, polystyrene resins, (meth) acrylic resins, and the like can be used. The shape of the adherend is not limited to a film, a sheet, or a plate, but may be a fiber, a cylinder, or any other shape.

The polyester resin composition contained in the adhesive layer (B) has a carboxyl terminal group content of 25 geq.
/ 10 ⁶ g or less. More preferably, it is 15 geq / 10 ⁶ g or less. 25 geq / 10 ⁶
When the amount exceeds g, the effect of inhibiting hydrolysis is not sufficient, and the adhesive strength of the laminate is likely to be reduced by wet heat treatment.
When the carboxyl terminal group content is 25 geq / 10 ⁶ g or less, the copolymerized polyester resin is less susceptible to hydrolysis and the decrease in molecular weight is suppressed, so that the moisture resistance and water resistance of the adhesive layer are improved.

In the present invention, the polyester resin composition contained in the adhesive layer (B) has a carboxyl terminal group content of 2
In order to reduce the amount to 5 geq / 10 ⁶ g or less, the polyester resin composition of the present invention is subjected to heat treatment at any stage after the polycondensation reaction of the copolymerized polyester, so that a compound capable of reacting with a carboxyl group is converted to the copolymerized polyester. This can be substantially achieved by reacting with the carboxyl end groups of the resin. The heat treatment is preferably performed in a temperature range of 60 ° C to 300 ° C for 5 seconds to 1 day. Heat treatment temperature is 6
If the heat treatment is performed at less than 0 ° C or for less than 5 seconds, the reaction of the carboxyl end group is insufficient, and when the heat treatment temperature exceeds 300 ° C, thermal decomposition of the copolyester resin occurs and the carboxyl end group increases. Resulting in. When the heat treatment time exceeds one day, the reaction of the carboxyl terminal group is completed, which is not only ineffective, but also undesirably reduces the productivity.

The metal plate used in the laminate of the present invention is not particularly limited, but is preferably a plate made of copper, iron, aluminum, tinplate or the like, and may be various metal alloy plates used for general purposes. Further, a plated product such as tin or zinc, or a chemical conversion product such as zinc phosphate or chromate may be used.

In the laminate of the present invention, the adhesive layer (B) comprising the copolymerized polyester resin composition may be formed by any method. Dissolve, apply on plastic film or plastic sheet layer (A),
Then, a method of removing the solvent is preferable. Alternatively, an adhesive layer (B) can be formed by applying a solution in which the copolymerized polyester resin composition is dissolved to the metal plate layer (C) and removing the solvent.

The organic solvent used for forming the adhesive layer (B) is not particularly limited as long as it can dissolve the copolymerized polyester resin composition of the present invention. Aromatic solvents such as toluene and xylene, methylene chloride, chloroform, carbon tetrachloride,
Chlorine solvents such as 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene and dichlorobenzene, ester solvents such as ethyl acetate, isophorone and γ-butyrolactone, acetone, methyl ethyl ketone and methyl isobutyl ketone , Ketone solvents such as cyclohexone, diethyl ether, ethyl cellosolve, butyl cellosolve, tetrahydrofuran, ether solvents such as 1,4-dioxane, methanol, ethanol,
alcohol solvents such as n-propanol, isopropanol, n-butanol, n-butane, isobutane, n
-Aliphatic hydrocarbon solvents such as pentane, n-hexane, n-heptane, n-octane and nonane, and alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane. These can be used alone or in combination of two or more.

Next, a plastic film or plastic sheet layer (A), an adhesive layer (B) and a metal plate layer (C) are arranged so as to form a layer. A laminate is formed by a known method.

At this time, the preheating temperature of the adherend (usually a metal plate) when the adherends are bonded to each other via the adhesive layer (B) is preferably in the range of 100 to 220 ° C. , 1
More preferably, the temperature is in the range of 50 ° C to 200 ° C. If the preheating temperature is lower than 100 ° C., no matter how much the pressure is increased, a material having a large adhesive strength cannot be obtained. on the other hand,
If the preheating temperature exceeds 220 ° C., the P
It is not preferable because the layer of the ET film or the PET sheet is deformed or wrinkles are generated. The pressure at the time of bonding is preferably 20 kPa or more, and 50 to 30 kPa.
More preferably, it is 0 kPa. Pressure during bonding is 2
If the pressure is less than 0 kPa, a material having high adhesive strength cannot be obtained even if the preheating temperature is increased and the pressing time is lengthened. Furthermore, it is preferable that the pressure bonding time at the time of bonding is 0.2 to 5 seconds. If the pressing time is less than 0.2 seconds, a material having a large adhesive strength cannot be obtained even if the preheating temperature is increased. On the other hand, if the pressing time exceeds 5 seconds, there is no problem in the adhesive strength of the obtained laminate, but it is not preferable because the productivity is poor.

In the polyester resin composition of the present invention, if necessary, a heat stabilizer such as phosphoric acid, an antioxidant such as a hindered phenol compound, a crystal nucleating agent such as talc or silica, a lubricant, a titanium oxide, etc. Pigments, fillers, antistatic agents,
A conventionally known additive such as a foaming agent may be contained. Further, in order to impart flame retardancy, bromine-based flame retardants, metal hydroxides, metal oxides such as antimony trioxide, phosphates, borates, metal sulfides, ammonium salts, organic nitrogen-based flame retardants, silicon A flame retardant or a phosphorus flame retardant may be blended. Furthermore, the copolymerized polyester resin of the present invention can be used alone as a resin for an adhesive, but can also be used in combination with a curing agent such as an isocyanate resin, a phenol resin, a melamine resin, and an epoxy resin.

[0037]

The polyester resin composition of the present invention has adhesiveness,
And it is excellent in heat resistance and moisture resistance. This is because a copolyester resin having a low glass transition point is used, so that the adhesiveness to the substrate is high. Furthermore, since the carboxyl terminal group is blocked, a decrease in moisture resistance and water resistance caused by a low glass transition point can be suppressed.

[0038]

The present invention will now be described by way of examples. The properties of the copolymerized polyester resin and the laminate were measured by the following methods.

(1) Intrinsic Viscosity ([η]) This is a value determined from the solution viscosity measured at 20 ° C. using an equal mass mixture of a phenol and ethane tetrachloride as a solvent for a polyester resin.

(2) Glass transition point (Tg) of copolymerized polyester resin Differential scanning calorimeter SSC5200 manufactured by Seiko Denshi Kogyo KK
Using a mold, the measurement was performed at a heating rate of 10 ° C./min.

(3) Amount of carboxyl terminal group ([COOH]) of polyester resin and polyester resin composition 0.5 g of polyester resin was added to dioxane / distilled water = 10
/ 1 (mass ratio) in 50 ml of a mixed solvent, heated under reflux, and titrated with a 0.1 × 10 ³ mol / m ³ potassium hydroxide methanol solution.

(4) Intrinsic Viscosity Retention The polyester resin composition was placed in a thermo-hygrostat at 60 ° C. and 95% RH for 96 hours, and the intrinsic viscosity before and after the treatment was measured. Next, based on this result, the retention rate of the intrinsic viscosity before and after the wet heat treatment was determined by the following equation. [Η] Retention (%) = ([η] after wet heat treatment / [η] before wet heat treatment) × 100 The retention of the intrinsic viscosity was 80% or more.

(5) Adhesive Strength of Laminate Using Tensilon RTC-1210 manufactured by Orientec, under the atmosphere of 20, 60 ° C., and the laminate at 60 ° C., 9
After placing in a 5% RH constant temperature and humidity chamber and treating for 96 hours, 2
The adhesive strength of the laminate having a sample width of 10 mm was measured in an atmosphere of 0 ° C. at a tensile speed of 50 mm / min. Adhesion strength of 10 N / cm or more was regarded as acceptable.

The production of the copolymerized polyester resin was conducted according to the following method.

Resin 1 In an esterification reactor, 35 terephthalic acid was added as an acid component.
Mol%, isophthalic acid 35 mol%, sebacic acid 30
Mol%, and the amount of 1,4-butanediol as a glycol component was 100 mol%, and the pressure was 0.5 MPa.
G. The esterification reaction was performed at a temperature of 250 ° C. for 4 hours. After transferring the obtained esterified product to the polycondensation reaction tank, 4 × 10 ⁻⁴ mol of tetrabutyl titanate was added as a polycondensation catalyst to 1 mol of the acid component constituting the polyester. Then, the reaction system was finally set to 0.4 hP for 60 minutes.
The pressure was gradually reduced until a was reached, and the polycondensation reaction was carried out at 240 ° C. for 4 hours.
Copolyester resin 1 having a carboxyl terminal group content of 28 geq / 10 ⁶ g was obtained.

Resin 2 An amount of 50 mol% of terephthalic acid, 20 mol% of isophthalic acid, 30 mol% of sebacic acid as an acid component, and 55 mol% of ethylene glycol and 45 mol% of neopentyl glycol as a glycol component. Except for the preparation,
Copolyester resin 2 was produced in the same manner as resin 1.

Resin 3 50 mol% of terephthalic acid and 50 mol% of isophthalic acid as acid components, 45.5 mol% of ethylene glycol, 50 mol% of neopentyl glycol, and 4.5 mol of polytetramethylene glycol as glycol components. Copolymerized polyester resin 3 was produced in the same manner as in resin 1, except that it was charged in an amount of mol%.

Resin 4 As the acid component, 25 mol% of terephthalic acid, 15 mol% of isophthalic acid, 38 mol% of sebacic acid, (10-oxa-9-oxide-9,10-dihydro-9-phosphaphenanthrene- 9-yl) Copolymerized polyester resin 4 was produced in the same manner as in Resin 1 except that 22 mol% of methyl succinic acid, 55 mol% of ethylene glycol and 45 mol% of neopentyl glycol as glycol components were charged. did.

Resin 5 After completion of the polycondensation reaction of Resin 4, N, N'-
(2,6,2 ′, 6′-tetraisopropyldiphenyl) carbodiimide was added to the polycondensation reaction tank in an amount of 90 geq / 10 ⁶ g with respect to the copolymerized polyester resin, and reacted at a pressure of 0.1 MPaG for 1 hour. A polyester resin composition 5 having an intrinsic viscosity of 0.94, a glass transition point of 5 ° C., and a carboxyl end group content of 10 geq / 10 ⁶ g was obtained.

Resin 6 50 mol% of terephthalic acid and 50 mol% of isophthalic acid as acid components, 50 mol% of ethylene glycol and 50 mol% of neopentyl glycol as glycol components
Copolymerized polyester resin 6 was produced in the same manner as in Resin 1 except that it was charged in the amount shown below.

Resin 7 A copolymerized polyester resin 7 was produced in the same manner as in Resin 1 except that terephthalic acid was used in an amount of 30 mol%, isophthalic acid was used in an amount of 30 mol%, and sebacic acid was used in an amount of 40 mol%. did.

Resin 8 Copolyester resin 8 was produced in the same manner as Resin 1 except that the polycondensation reaction temperature was 280 ° C. Table 1 shows the physical property values of the obtained copolyester resin.

Examples 1 to 7, Comparative Examples 1 to 5 Copolymerized polyester resins 1 to 4 and 6 to 8 and a compound capable of reacting with a carboxyl terminal group shown in Table 1 were mixed with a mixed solvent of toluene and methyl ethyl ketone ( (Volume ratio 1/1) to give a concentration of 30% by mass to obtain a solution of the polyester resin composition. The solution was applied on a 25 μm PET film, placed in a drier, dried at 80 ° C. for 2 minutes, and then dried at 150 ° C. for 3 minutes to remove the solvent.
An m-thick adhesive layer was formed. Next, the PET film on which the adhesive layer was formed was placed so that the metal plate shown in Table 1 preheated to 180 ° C. was in contact with the adhesive layer, and the pressure was set to 0.
The laminate was composed of a PET film / an adhesive layer composed of a polyester resin composition / a metal plate by being pressure-bonded with a sealer at 1 MPa and a pressure-bonding time of 1 second. Table 1 shows the characteristics of the obtained laminate.

Example 8 Copolyester resin 5 was dissolved in a mixed solvent of toluene and methyl ethyl ketone (volume ratio 1/1) to a concentration of 30% by mass to prepare a solution of a polyester resin composition. In the same manner as in Example 1, a laminate was obtained.

[0055]

[Table 1]

Comparative Example 1 does not contain a compound capable of reacting with a carboxyl terminal group, so that the adhesive strength by wet heat treatment and the retention rate of the intrinsic viscosity of the polyester resin as the adhesive layer are low, and the wet heat resistance is low. It could not be improved enough. In Comparative Example 2, since the content of the compound capable of reacting with the carboxyl terminal group was large, when the adhesive layer was provided on the polyester film, bleeding occurred on the adhesive layer, and the adhesive strength of the laminate was further reduced. Got lower. Resin 6
In Comparative Example 3, a high molecular weight polyester resin was not obtained because of a high glass transition point, and as shown in Comparative Example 3, sufficient adhesive strength was not obtained when a laminate was formed. Since the resin 7 has a low glass transition point, as shown in Comparative Example 4, the adhesive strength at 60 ° C. when formed into a laminate was low and did not have heat resistance. Resin 8 has a large amount of carboxyl terminal groups of the copolymerized polyester, and therefore, as shown in Comparative Example 5, the adhesive strength by wet heat treatment and the retention rate of the intrinsic viscosity of the polyester resin as the adhesive layer are low, and the wet heat resistance is low. Could not be improved sufficiently.

[0057]

According to the present invention, a polyester resin composition having good adhesion to a metal plate and a plastic film or a plastic sheet can be obtained. Accordingly, the polyester resin composition of the present invention can be used for adhesives in the fields of electricity, electronics, machinery, food, construction, and automobile, specifically, electric wire coatings, electric components such as flat cables, PCM paints, It can be particularly suitably used as an adhesive resin for packaging materials such as building materials, foods and pharmaceuticals.

Continued on the front page F term (reference) 4F100 AB01C AH03 AH08 AK01A AK41B AK41J AL01B AL05B BA03 BA07 BA10A BA10C EC03 EH46 GB07 GB32 GB41 JA05B JD04 JJ03 JL11 YY00B 4J002 CD012 CD052 CF031 CF051 CF080 EG EG EG EG EGCH CH021

Claims (3)

[Claims] 1. A composition comprising one or more dicarboxylic acid components and one or more glycol components, and having a glass transition point of -3.
0-40 ° C, the amount of carboxyl end groups is 50 geq / 10
A polyester resin composition, characterized in that the amount of a compound capable of reacting with a carboxyl end group is contained in an amount of ⁶ g or less of a copolymerized polyester resin satisfying the following formula. 0.5 ≦ [X] / [COOH] ≦ 5 (wherein [X] is the total content of the compound capable of reacting with the carboxyl terminal group in the copolymerized polyester resin (geq / 1
0 ⁶ g), representing the [COOH] is a carboxyl end group amount of copolymerized polyester resin (geq / 10 ⁶ g). ) 2. A plastic film or plastic sheet layer, (B) an adhesive layer made of the polyester resin composition according to claim 1, and (C) a metal plate layer. A laminate characterized by the above. 3. The laminate according to claim 2, wherein the amount of carboxyl terminal groups of the polyester resin composition contained in the layer (B) is 25 geq / 10 ⁶ g or less.