JP2016108455A - Polyester resin composition, and aqueous polyester solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester composition which has excellent adhesiveness to a polyester resin substrate and a hard coat layer formed of, for example, an active energy ray-curable resin composition and which meets a need for achieving a higher refractive index, and to provide an aqueous polyester solution.SOLUTION: The polyester resin composition is provided which contains: a polyester resin [I] composed of a polyol component (A), a polyvalent carboxylic acid component (B), and an acrylic resin (C) having an ester forming functional group; and a crosslinking agent [II], the polyester resin composition containing as the polyvalent carboxylic acid component, a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures. The aqueous polyester solution is obtained by dissolving or dispersing the polyester resin composition in an aqueous solvent.SELECTED DRAWING: None

Description

  The present invention relates to a polyester-based resin composition and a polyester-based aqueous liquid. More specifically, the present invention relates to a polyester-based resin composition excellent in adhesiveness between a polyester-based resin substrate and a hard coat layer, and corresponding to a higher refractive index. And a polyester-based aqueous liquid.

  Conventionally, polyester films have been used in various industrial fields such as packaging materials, magnetic cards, and printing materials. As the polyester film, for example, a thermoplastic polyester such as polyethylene terephthalate (PET) or a copolymer thereof mixed with other resins as necessary is melt-extruded and molded, and then biaxially stretched. Heat-fixed ones are used. Such a polyester film is excellent in various physical properties such as mechanical strength, heat resistance, chemical resistance, etc., but its surface is highly crystallized, for example, adhesion to paint, adhesive, ink, etc. There is a problem of poor sex.

Therefore, conventionally, by providing a film formed by applying a polyester resin aqueous liquid (solution or dispersion) on the surface of a polyester film as a primer layer, adhesion to a paint or the like is achieved. Improvements are being made.
For example, a hard coat film in which a hard coat layer is laminated on a polyester film is excellent in hardness and scratch resistance and is used for optical applications, etc. The primer layer is also provided between the polyester film and the hard coat layer in this hard coat film. Is provided. In the film having such a configuration, there is a problem in that the iris-like reflection due to the difference between the refractive index of the primer layer and the refractive index of the polyester film and the hard coat layer occurs, which impairs visibility.

  As a means for solving the above problem, for example, a method of forming a polyester resin film having a refractive index increased by copolymerizing a polyol component having a fluorene structure as a primer layer has been proposed (for example, Patent Document 1). And 2).

  However, the primer layer formed from the polyester skeleton disclosed in Patent Documents 1 and 2 does not have sufficient adhesion to the hard coat layer. In addition, these high refractive index polyester resins have a high glass transition temperature and a hard coating. Therefore, there was a tendency that the adhesion with the hard coat layer was further insufficient.

  As a means to improve the adhesion to the hard coat layer, it contains a polyester resin produced by an esterification reaction of a reactive raw material composed of a compound having an ester-forming functional group, and the reactive raw material contains an acrylic polymer Polyester resin compositions that have been proposed have also been proposed. Adhesion of a hard coat layer formed from an ultraviolet curable resin by interposing a primer layer formed from such a polyester resin composition between a hard coat layer formed from an ultraviolet curable resin and a substrate. Can be improved (see, for example, Patent Document 3).

  The polyester resin composition disclosed in Patent Document 3 is intended to improve the adhesion between the polyester film and the hard coat layer, but since the primer layer does not have a high refractive index, it has a high refractive index. When the amount of copolymerization of the high refractive index monomer is increased for imparting, the adhesion with the hard coat layer may be lowered with the increase of the glass transition temperature. Furthermore, although the polyester resin described in Patent Document 3 performs polymerization under reduced pressure, due to poor compatibility between the acrylic resin and the polyester resin, the polyester resin foams violently at the time of reduced pressure, and the liquid level rapidly rises. There is also a problem that is difficult.

  In recent years, hard coating agents and diluting solvents used therefor have been diversified, and the resin composition described in Patent Document 3 has insufficient adhesiveness depending on the type of hard coating agent and diluting solvent.

JP 2012-7154 A JP 2009-242461 A JP2011-219545A

  Therefore, the present invention has excellent adhesiveness between the polyester-based resin base material and a hard coat layer formed from, for example, an active energy ray-curable resin composition, and supports a higher refractive index under such a background. It is an object of the present invention to provide a polyester resin composition and a polyester aqueous solution.

  However, as a result of intensive studies in view of such circumstances, the present inventors have found that a polyester system comprising a polyol component (A), a polyvalent carboxylic acid component (B), and an acrylic resin (C) having an ester-forming functional group. In the polyester resin composition containing the resin [I] and the crosslinking agent [II], two or more carboxylic acid anhydride structures are used as the polyvalent carboxylic acid component (B) constituting the polyester resin [I]. By containing the carboxylic acid anhydride (b1), a polyester resin composition excellent in adhesiveness between the polyester resin substrate and a hard coat layer formed from, for example, an active energy ray-curable composition is obtained. As a result, the present invention has been completed.

  That is, the gist of the present invention is that the polyester resin [I] and the crosslinking agent [II] comprising the polyol component (A), the polyvalent carboxylic acid component (B), and the acrylic resin (C) having an ester-forming functional group. A polyester resin composition comprising a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures as a polyvalent carboxylic acid component (B). It is about.

  Furthermore, in this invention, the polyester-type aqueous liquid in which the said polyester-type resin composition is melt | dissolved or disperse | distributed to an aqueous solvent is also provided.

The polyester-based resin composition of the present invention has an excellent effect in adhesion between a polyester-based resin substrate and a hard coat layer formed from, for example, an active energy ray-curable resin composition. It is very useful as a primer layer for providing a hard coat layer on a polyester resin substrate. Furthermore, since the polyester resin composition of the present invention has an excellent adhesiveness with a polyester resin substrate and a hard coat layer and also achieves a high refractive index, the polyester resin composition of the present invention is an optical device that requires visibility. This is also highly expected in applications.
Further, the polyester-based aqueous liquid of the present invention is excellent in adhesiveness with a polyester-based resin substrate and a hard coat layer, and is very useful as a material for forming a film such as a primer layer having a high refractive index. .

The present invention is described in detail below, but these show examples of desirable embodiments.
In the present specification, (meth) acryl means acryl or methacryl, and (meth) acrylic resin is a polymerized polymerization component containing at least one of acrylate monomer and methacrylate monomer. It is resin obtained.

<Polyester resin composition>
The polyester resin composition of the present invention comprises a polyester resin [I] and a crosslinking agent [II].

(Polyester resin [I])
The polyester resin [I] is obtained by copolymerizing a polyol component (A), a polyvalent carboxylic acid component (B), and an acrylic resin (C) having an ester-forming functional group.
First, the polyol component (A) will be described.

[Polyol component (A)]
The polyol component (A) used in the present invention is one kind selected from the group consisting of a chain aliphatic hydrocarbon compound, a cyclic aliphatic compound or an aromatic hydrocarbon compound having two or more hydroxyl groups in one molecule. 2 or more, usually at least a dihydric alcohol.
Among the polyol components (A), it is preferable to contain a chain aliphatic hydrocarbon compound having two or more hydroxyl groups in one molecule from the viewpoint of adhesion to the hard coat, and in particular, the number average molecular weight is 1,000. It is preferable to contain the above polyalkylene glycol (a1).

  Such polyalkylene glycol (a1) has a number average molecular weight of 1,000 or more, and thus has good adhesion to a polyester resin substrate and a hard coat layer. The reason why the adhesiveness is good is not clear, but the presence of a polyalkylene glycol having a large molecular weight to some extent provides (i) moderate flexibility and flexibility. (Ii) acrylic resin (C ) Forming a phase separation structure with the part, and the acrylic resin (C) part is partially oriented at the hard coat layer interface. (Iii) The polyalkylene glycol acts as a linker and the acrylic resin (C) part is It is presumed that it is oriented at the hard coat layer interface.

  The range of the number average molecular weight is preferably 1,000 to 20,000, particularly preferably 1,200 to 18,000, more preferably 1,500 to 15,000, particularly preferably 1. 800 to 12,000. When the number average molecular weight is too small, the adhesiveness tends to decrease. In addition, when the number average molecular weight is too large, the compatibility with the polyester resin [I] is lowered, and it tends to be difficult to copolymerize or obtain a uniform polymer.

In addition, a number average molecular weight is computed by the following formula from the hydroxyl value (mgKOH / g) calculated | required by the acetic anhydride pyridine method based on JISK0070.
[formula]
2 x 1000 x 56.1 ÷ hydroxyl value (mgKOH / g)

Specific examples of such polyalkylene glycol (a1) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Among these, polyethylene glycol is preferable in terms of imparting hydrophilicity to the polyester resin [I] and facilitating the formation of an aqueous dispersion.
In the present invention, one or more polyalkylene glycols can be used. For example, polyalkylene glycols having different alkylene groups or polyalkylene glycols having different number average molecular weights can be used in combination.

  The content of the polyalkylene glycol (a1) in the polyol component (A) is preferably 0.01 to 10 mol%, particularly 0.05 to 9 mol%, based on the entire polyol component (A). More preferably, it is 0.1 to 8 mol%, and particularly preferably 0.15 to 5 mol%. If the content is too small, the adhesiveness tends to decrease, and if it is too large, the refractive index, blocking resistance, water resistance, and adhesiveness tend to decrease.

  Further, in the present invention, a fluorene compound (a2) represented by the following general formula (1) is contained as the polyol component (A) because a film having a high refractive index and a good appearance can be formed. It is preferable.

In Formula (1), R ₁ is an alkylene group having 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group. R ₂ , R ₃ , R ₄ and R ₅ are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group or an aralkyl group, and these may be the same or different from each other.
Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a neopentyl group, and an isopentyl group. Examples of the aryl group include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, and an o-xylyl group. Examples of the aralkyl group include aralkyl groups having 7 to 20 carbon atoms, and examples thereof include a benzyl group and a phenethyl group.

In the fluorene compound (a2) represented by the general formula (1), R ₁ is preferably a methylene group or an ethylene group. R ₂ , R ₃ , R ₄ and R ₅ are preferably a hydrogen atom, a methyl group or an ethyl group, and particularly preferably a hydrogen atom. And as this fluorene type compound (a2), bisphenoxyethanol fluorene and bis (4- (2-hydroxyethoxy) phenyl) fluorene are preferably used from viewpoints of availability. 1 type (s) or 2 or more types can be used for a fluorene type compound (a2).

  The content of the fluorene compound (a2) in the polyol component (A) is preferably from 5 to 99.99 mol%, particularly from 20 to 95 mol%, more preferably from the entire polyol component (A). It is preferably 30 to 90 mol%, particularly 45 to 85 mol%. If the content is too small, sufficient refractive index, blocking resistance, and water resistance tend to be difficult to obtain.If the content is too large, water dispersion becomes difficult and adhesiveness decreases, There is a tendency that cracks occur and haze occurs when a polyester-based aqueous liquid is applied to a polyester-based resin substrate such as a polyester film, dried, or when the polyester film with a resin coating is stretched.

  In the present invention, as the polyol component (A), in addition to the polyalkylene glycol (a1) and the fluorene compound (a2), other dihydric alcohols may further be contained.

As said other dihydric alcohol, for example,
Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3- Propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butadiol, 1,4-butanediol Aliphatic diols such as 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanediol;
1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantanediol, 2,2,4,4-tetramethyl-1,3 -Alicyclic diols such as cyclobutanediol;
4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol S, bisphenol A, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, Aromatic diols such as p-xylene diol and their ethylene oxide and propylene oxide adducts can be mentioned.
One kind selected from these other dihydric alcohols may be used, or two or more kinds may be used in combination.

  Among these, linear aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, etc. However, it is preferably used because it does not cause an unnecessary increase in the glass transition temperature. In particular, diethylene glycol and triethylene glycol are preferred in that they impart moderate flexibility and hydrophilicity, suppress a decrease in refractive index, and have a high boiling point and are unlikely to cause out-of-system distillation during the esterification reaction.

  The content of the other dihydric alcohol in the polyol component (A) is preferably from 0.1 to 95 mol%, particularly from 5 to 80 mol%, more preferably from the whole polyol component (A). It is preferable that it is 10-70 mol%, especially 15-55 mol%. If the content is too small, the polymerization becomes difficult, the flexibility is lost, the adhesiveness and water dispersibility are lowered, or the polyester-based aqueous liquid is applied to a polyester-based resin substrate such as a polyester film. When drying or stretching of the polyester film with a resin coating, cracks tend to occur and haze tends to occur. When too much, the refractive index, blocking resistance, and water resistance tend to decrease.

  In addition to the above polyol, the polyol component (A) used in the present invention is a trihydric or higher polyhydric alcohol, such as pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylol. A small amount of ethane, 1,3,6-hexanetriol, adamantanetriol, or the like can be used.

[Polyvalent carboxylic acid component (B)]
The polyvalent carboxylic acid component (B) used in the present invention contains a divalent or higher polyvalent carboxylic acid, and usually contains at least a divalent carboxylic acid. These polyvalent carboxylic acids may have a structure such as an ester, chloride, or acid anhydride.

The present invention has many functions in that it has a function as a chain extender, a function as a hydrophilicity-imparting agent, and a function of forming a reaction point with a crosslinking agent [II] described later in the polyester resin [I]. As the monovalent carboxylic acid component (B), a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures is contained.
The carboxylic acid anhydride (b1) may be any one having at least two carboxylic acid anhydride structures, and examples thereof include carboxylic acid dianhydrides and the like, which are less likely to cause gelation during resin production. Tetracarboxylic dianhydride is preferred from the standpoint of water dispersibility during water treatment.

  Specific examples of these carboxylic acid anhydrides (b1) include, for example, 1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic anhydride), 1,2,3,4-butanetetracarboxylic acid. Dianhydride, 1,2,3,4-pentanetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 4,4-oxydiphthalic dianhydride, 5- (2,5dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-cyclohexene-1,2-dicarboxylic acid Anhydride, cyclopentanetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, ethylene Recall bis trimellitate dianhydride, 2,2 ', 3,3'-diphenyltetracarboxylic dianhydride, 2,2', 3,3'-diphenylsulfone tetracarboxylic anhydride, thiophene-2,3 4,5-tetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, and the like. Among them, 5- (2,5-dioxotetrahydrofuryl)-is preferable because it is mild in reactivity and hardly causes gelation. 3-Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-cyclohexene-1,2-dicarboxylic acid anhydride and the like are preferably used. One kind selected from these can be used alone, or two or more kinds can be used in combination.

The content of the carboxylic acid anhydride (b1) in the polyvalent carboxylic acid component (B) is preferably 5 to 50 mol%, particularly 10 to 40%, based on the entire polyvalent carboxylic acid component (B). It is preferable that it is mol%, further 12-35 mol%, especially 15-30 mol%. If the content is too small, it tends to be difficult to disperse the produced polyester resin [I] in an aqueous solvent, and if it is too much, the polyester resin [I] is being produced. There is a tendency to gel.
The polyvalent carboxylic acid component (B) can be used alone or in combination of two or more.

As the polyvalent carboxylic acid component (B), in addition to the carboxylic acid anhydride (b1), another polyvalent carboxylic acid component (B), for example, a divalent carboxylic acid may be contained.
Examples of the divalent carboxylic acid include
Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, benzylmalonic acid, diphenic acid, 4,4'-oxydibenzoic acid;
Malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, thiodipropionic acid , Aliphatic dicarboxylic acids such as diglycolic acid;
Alicyclics such as 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, adamantanedicarboxylic acid, etc. Dicarboxylic acids;
Etc.

  Further, naphthalenedicarboxylic acid may be contained, and examples of naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid. One kind selected from these naphthalenedicarboxylic acids may be used, or two or more kinds may be used in combination. In view of availability, 2,6-naphthalenedicarboxylic acid and dimethyl 2,6-naphthalenedicarboxylic acid are preferable.

  Further, for the purpose of improving water dispersibility, a small amount of a polyvalent carboxylic acid having a sulfonate group may be contained. For example, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, sulfone Examples include terephthalic acid, 4-sulfonaphthalene-2,6-dicarboxylic acid, and alkali metal salts thereof. One kind selected from these polycarboxylic acids having a sulfonate group may be used, or two or more kinds may be used in combination. From the viewpoint of availability, 5-sulfoisophthalic acid, dimethyl 5-sulfoisophthalate and alkali metal salts thereof are preferable.

  One kind selected from these polyvalent carboxylic acids may be used, or two or more kinds may be used in combination.

  Among these, aromatic dicarboxylic acids are preferable in terms of adhesiveness, hydrolysis resistance, and refractive index, and terephthalic acid, isophthalic acid, and esters thereof are particularly preferable in terms of adhesiveness.

  The content of the divalent carboxylic acid in the polyvalent carboxylic acid component (B) is preferably 50 to 95 mol%, particularly 60 to 90 mol%, based on the entire polyvalent carboxylic acid component (B). Further, it is preferably 65 to 88 mol%, particularly preferably 70 to 85 mol%. When the content is too small, the water resistance tends to decrease or gelation occurs during the production process, and when the content is too large, water dispersion tends to be difficult.

  In addition to the above-mentioned various divalent carboxylic acids, the polyvalent carboxylic acid component (B) used in the present invention contains a trivalent or higher polyvalent carboxylic acid for the purpose of increasing branch points in the polyester resin [I]. A small amount can be used. For example, trimellitic acid, pyromellitic acid, adamantanetricarboxylic acid, trimesic acid and the like can also be used.

[Acrylic resin having ester-forming functional group (C)]
The acrylic resin (C) used in the present invention is an acrylic resin having a functional group capable of forming an ester bond, and preferably has a functional group in the side chain of the acrylic resin in terms of adhesiveness. The content of the functional group in the acrylic resin (C) is preferably a value represented by the following formula of 2 or more, particularly 2 to 60, more preferably 2.1 to 25, and particularly 2. It is preferable that it is 2-20. In addition, when there is too much functional group content, there exists a tendency to gelatinize.

[formula]
Functional group moles per gram of acrylic resin x weight average molecular weight

Examples of such functional groups include a carboxyl group, a hydroxyl group, a glycidyl group, and an alkoxysilyl group. Among them, a carboxyl group, a hydroxyl group, and a glycidyl group are preferable from the viewpoint of adhesiveness, and in particular, gelation is not easily caused. A carboxyl group is preferred.
That is, as the acrylic resin (C) having an ester-forming functional group, for example, a carboxyl group-containing acrylic resin (c1), a hydroxyl group-containing acrylic resin (c2), a glycidyl group-containing acrylic resin (c3), or an alkoxy It is mentioned that it is a silyl group-containing acrylic resin (c4). Among them, in terms of adhesion, a carboxyl group-containing acrylic resin (c1), a hydroxyl group-containing acrylic resin (c2), a glycidyl group-containing acrylic resin (c3) In particular, the carboxyl group-containing acrylic resin (c1) is preferable in that gelation is not easily caused.

  In the present invention, the content of the acrylic resin (C) is preferably 3 to 30% by weight, more preferably 4 to 25% by weight, particularly 5 based on the whole polyester resin [I]. It is preferably ˜20% by weight. If the content is too small, the adhesiveness tends to decrease, and if it is too large, gelation or the refractive index tends to decrease.

In the present invention, the composition of the acrylic resin (C) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate It is preferable that the (meth) acrylic monomer having an alkyl chain having 1 to 8 carbon atoms, such as a main component of the polymerization component, and further a monomer having the above ester-forming functional group as the polymerization component, particularly It is desirable to use a (meth) acrylic monomer having a C 1-6 alkyl chain as the main component of the polymerization component and a monomer having the above ester-forming functional group as the polymerization component. In addition, when carbon number of the alkyl chain in a (meth) acryl monomer is too large, there exists a tendency for water dispersibility and solvent resistance to fall.
From the viewpoint of adhesiveness, it is preferable that styrene is less as a copolymerization component, and the copolymerization amount of styrene is preferably 50 mol% or less, particularly 20 mol% or less, based on the entire acrylic resin (C). Further, it is preferably 5 mol% or less, particularly preferably 0 mol%.

In the present invention, the weight average molecular weight of the acrylic resin (C) is preferably 500 to 30,000, particularly 1,000 to 20,000, and more preferably 1,500 to 15,000. If the weight average molecular weight is too small, the terminal double bond concentration of the acrylic resin (C) is high, and it tends to gel, and the adhesiveness tends to decrease. If the weight average molecular weight is too large, it is difficult to disperse in water. Or the compatibility with the polyester-based resin [I] tends to decrease, making it difficult to copolymerize or obtaining a uniform resin.
In addition, a weight average molecular weight can be calculated | required by GPC analysis and polystyrene conversion.

The glass transition temperature of the acrylic resin (C) is preferably -85 ° C to 100 ° C, particularly preferably -70 ° C to 80 ° C, and more preferably -60 ° C to 70 ° C. If the glass transition temperature is too low, water dispersibility and solvent resistance tend to decrease. If it is too large, the adhesiveness decreases, or the polyester-based aqueous liquid is applied to a polyester-based resin substrate such as a polyester film. There is a tendency that cracks occur and haze occurs during drying or stretching of the polyester film with a resin coating.
The glass transition temperature can be determined by a differential scanning calorimeter.

[Production Method of Polyester Resin [I]]
The polyester resin [I] used in the present invention is composed of the polyol component (A), the polyvalent carboxylic acid component (B), and an acrylic resin (C) having an ester-forming functional group. For the production method of the resin, for example,
(I) a carboxyl group-containing prepolymer composed of an acrylic resin (C) having a polyol component (A), a polyvalent carboxylic acid component (B), and an ester-forming functional group, and a carboxyl having two or more carboxylic anhydride structures. A method of chain extension with an acid anhydride (b1),
(Ii) A polyester polyol comprising a polyol component (A) and a polyvalent carboxylic acid component (B) is chain-extended with a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures, and then ester-forming properties. There is a method of reacting an acrylic resin (C) having a functional group.

The method (i) will be described.
First, a predetermined amount of the polyol component (A), the polyvalent carboxylic acid component (B) excluding the carboxylic acid anhydride (b1), and the acrylic resin (C) having an ester-forming functional group are mixed without a solvent. At this time, the ratio (molar ratio) between the polyol component (A) and the polyvalent carboxylic acid component (B) excluding the carboxylic acid anhydride (b1) is the polyol component relative to 1 mol of the polyvalent carboxylic acid component (B). (A) is preferably 1.1 to 2 mol. However, it is not limited to this range, and can be adjusted as appropriate depending on the reaction.

  This mixture is charged into an appropriate reactor and heated to 170 to 250 ° C., thereby allowing the esterification reaction or transesterification reaction to proceed while distilling off water or methanol as a by-product. A polymer is produced. In addition, you may mix | blend acrylic resin (C) after the chain extension by the below-mentioned carboxylic anhydride (b1).

  Further, a hydroxyl group-containing prepolymer comprising a polyol component (A), a polyvalent carboxylic acid component (B) excluding the carboxylic acid anhydride (b1), and an acrylic resin (C) having an ester-forming functional group is converted into a carboxylic acid anhydride. Polyester resin [I] can be obtained by extending the chain with a carboxylic acid anhydride (b1) having two or more physical structures.

  A hydroxyl group-containing prepolymer obtained from the above-mentioned polyol component (A), polyvalent carboxylic acid component (B), and acrylic resin (C) having an ester-forming functional group is a carboxyl having two or more carboxylic anhydride structures. When chain-extending with the acid anhydride (b1), the reaction can be allowed to proceed even at room temperature, but can usually be started at 230 ° C. or lower, preferably 150 to 210 ° C., particularly preferably 165 to 200 ° C. Therefore, a solvent is not necessarily required for the above reaction, but if the viscosity of the reaction product at such a temperature is too high, an appropriate solvent can be used as appropriate to facilitate stirring.

  Examples of the solvent include ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, benzene, toluene, xylene, mesitylene, Aromatic solvents such as pseudocumene, alcohol solvents such as methanol, ethanol and isopropyl alcohol, amide solvents such as dimethylformamide and dimethylacetamide, glycol ether solvents such as butyl cellosolve and butyl carbitol, and acetate solvents thereof Can be mentioned.

  The above reaction is usually preferably allowed to proceed for 0.2 to 4 hours at a temperature of 150 to 210 ° C. under normal pressure. Particularly preferably, the reaction is allowed to proceed for 0.5 to 3 hours at a temperature of 165 to 200 ° C. under normal pressure.

The method (ii) will be described.
When obtaining the polyester polyol which consists of a polyol component (A) and a polyhydric carboxylic acid component (B), it can carry out by a well-known method.
Furthermore, after adding a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures to the obtained polyester polyol and chain extending under the same conditions as described above, an acrylic resin (C) is blended, Further, the reaction can be allowed to proceed for 0.2 to 3 hours at 165 to 200 ° C.

In the above methods (i) and (ii), during the reaction, an esterification catalyst, a transesterification catalyst, other polymerization catalysts, and the like can be appropriately blended. For example, tetrabutoxy titanium can be used. Various additives such as other stabilizers may be used.
Thus, bulk polyester resin [I] is obtained by the above-described method.

The weight average molecular weight of the polyester resin [I] thus obtained is preferably 2,000 to 60,000, particularly preferably 3,500 to 50,000, more preferably 5,000 to 40,000. is there. If the weight average molecular weight of the polyester resin [I] is too large, it tends to be difficult to prepare an aqueous liquid, particularly an aqueous dispersion, and the compatibility with other components also tends to be reduced. In addition, if the weight average molecular weight is too small, when a coating such as a primer layer is formed on a polyester-based resin substrate such as a polyester film using an aqueous liquid of such a resin, the toughness and heat-and-moisture resistance of the coating tend to decrease. There is.
In the present invention, the weight average molecular weight can be determined by, for example, GPC analysis and polystyrene conversion.

The glass transition temperature (Tg) of the polyester-based resin [I] used in the present invention is preferably 40 to 140 ° C, particularly preferably 50 to 120 ° C, and further preferably 60 to 105 ° C. If the glass transition temperature is too high, the adhesiveness will decrease, or cracks will occur during the application of polyester-based aqueous liquids on polyester-based resin substrates such as polyester films, drying, and stretching of polyester films with resin coating. There is a tendency for haze to occur. Moreover, when the glass transition temperature is too low, the heat resistance, blocking resistance, and refractive index tend to decrease.
The glass transition temperature (Tg) of the polyester resin [I] can be measured using, for example, a differential scanning calorimeter.

The acid value of the polyester-based resin [I] used in the present invention is preferably 15 to 150 mgKOH / g, particularly preferably 20 to 100 mgKOH / g, and further preferably 30 to 80 mgKOH / g. If the acid value is too high, the water resistance and the stability over time of the water dispersion tend to decrease, and if it is too low, it tends to be difficult to disperse in water.
The acid value of the polyester resin [I] can be determined by neutralization titration based on, for example, JIS K0070.

The refractive index of the polyester resin [I] used in the present invention is preferably 1.56 or more, particularly preferably 1.57 to 1.64, and further preferably 1.58 to 1.63. Especially preferably, it is 1.58 to 1.62. If the refractive index is too high, the glass transition temperature becomes too high, and cracks occur when the polyester-based aqueous liquid is applied onto a polyester-based resin substrate such as a polyester film, dried, or when the polyester film with the resin coating is stretched. Haze tends to occur, and if it is too low, iris reflection occurs when the hard coat layer is laminated, which tends to hinder visibility.
In addition, the refractive index said here is a refractive index with respect to D line (589 nm) in 25 degreeC.
The refractive index of the polyester resin [I] can be measured using, for example, an Abbe refractometer.

(Crosslinking agent [II])
The crosslinking agent [II] in the present invention may be a compound containing a functional group reactive with the functional group contained in the polyester resin [I]. For example, a functional group reactive with a carboxyl group may be used. The containing compound is used.

  Examples of the crosslinking agent [II] include compounds having an epoxy group, an oxazoline group, a carbodiimide group, an amino group, or an isocyanate group, a metal compound, an aziridine compound, and a melamine compound. Among them, a compound having an epoxy group, an oxazoline group or a carbodiimide group or a melamine compound is preferable, and a compound having an epoxy group or an oxazoline group is more preferable.

  Examples of the compound having an epoxy group include bisphenol A / epichlorohydrin type epoxy resin, sorbitol polyglycidyl ether (for example, “Denacol EX-611”, “Denacol EX-612”, “Denacol EX-” manufactured by Nagase ChemteX Corporation). 614 "," Denacol EX-614B "," Denacol EX-622 ", etc.), polyglycerol polyglycidyl ether (for example," Denacol EX-512 "," Denacol EX-521 "manufactured by Nagase ChemteX Corporation), penta Erythritol polyglycidyl ether (eg, “Denacol EX-411” manufactured by Nagase ChemteX), diglycerol polyglycidyl ether (eg, “Denacol EX-421” manufactured by Nagase ChemteX), glycerol Glycidyl ether (for example, “Denacol EX-313”, “Denacol EX-314” manufactured by Nagase ChemteX), etc.), trimethylolpropane polyglycidyl ether (for example, “Denacol EX-321” manufactured by Nagase ChemteX) Resorcinol diglycidyl ether (for example, “Denacol EX-201” manufactured by Nagase ChemteX), neopentyl glycol diglycidyl ether (for example, “Denacol EX-211” manufactured by Nagase ChemteX), 1,6 -Hexanediol diglycidyl ether (for example, “Denacol EX-212” manufactured by Nagase ChemteX Corporation), hydrogenated bisphenol A diglycidyl ether (for example, “Denacol EX-252” manufactured by Nagase ChemteX Corporation) , D Renglycol diglycidyl ether (for example, “Denacol EX-810”, “Denacol EX-811”, etc. manufactured by Nagase ChemteX), etc.), diethylene glycol diglycidyl ether (eg, “Denacol EX-850”, manufactured by Nagase ChemteX, "Denacol EX-851" etc.), polyethylene glycol diglycidyl ether (for example, "Denacol EX-821", "Denacol EX-830", "Denacol EX-832", "Denacol EX-841" manufactured by Nagase ChemteX Corporation) , “Denacol EX-861”, etc.), propylene glycol diglycidyl ether (eg, “Denacol EX-911” etc., manufactured by Nagase ChemteX), polypropylene glycol diglycidyl ether (eg, manufactured by Nagase ChemteX) "Denacol EX-941", "Denacol EX-920", "Denacol EX-931", etc. are mentioned. Among these, an aqueous type is preferable.

  Examples of the compound having an oxazoline group include addition-polymerizable 2-oxazolines (for example, 2-isopropenyl-2-oxazoline) having a substituent having an unsaturated carbon-carbon bond at the 2-position carbon position and other unsaturated groups. Examples include commercially available products such as “Epocross WS-500”, “Epocross WS-700”, “Epocross K-2010E”, “Epocross K-2020E” manufactured by Nippon Shokubai Co., Ltd. "Epocross K-2030E" etc. are mentioned.

  The compound having a carbodiimide group may be any compound containing at least two carbodiimide groups. For example, “Carbodilite V-02”, “Carbodilite V-02-L2”, and “Carbodilite V-04” manufactured by Nisshinbo Co., Ltd. ”,“ Carbodilite V-06 ”,“ Carbodilite E-01 ”,“ Carbodilite E-02 ”,“ Carbodilite E-04 ”and the like.

  Examples of the compound having an amino group include hexamethylenediamine and triethanolamine.

  Examples of the compound having an isocyanate group include toluylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, metaxylylene diisocyanate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated toluene. Isocyanate compounds such as diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate and their blocked isocyanate compounds, “Aquanate 100”, “Aquanate 110”, “Aquanate 200”, “Aquanate 210” ( And self-emulsifying water-dispersed polyisocyanate compounds such as those manufactured by Nippon Polyurethane Co., Ltd. Among these, a water dispersion type and a blocked isocyanate compound are preferable.

  Examples of metal compounds include metal alkoxides such as tetraethyl titanate, tetraethyl zirconate, and aluminum isopropionate, and aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, and the like. Examples include polyvalent metal acetylacetone and acetoacetate, metal chelate compounds of ethylenediaminetetraacetic acid coordination compounds, acetic acid-ammonium complex salts, ammonium-carbonate complex salts, and the like. Of these, the aqueous type is preferred.

  Any aziridine compound may be used as long as it contains at least two aziridine groups. Examples thereof include “Chemite PZ-33” and “Chemite DZ-22E” (manufactured by Nippon Shokubai Co., Ltd.).

  Examples of the melamine compounds include hexamethoxymethylol melamine, “Nicarak MW-30M”, “Nicarac MW-30”, “Nicarac MW-22”, “Nicarac MS-11”, “Nicarac” manufactured by Sanwa Chemical Co., Ltd. MS-011, “Nicarax MX-730”, “Nicarax MX-750”, “Nicarax MX-706”, “Nicarax MX-035” and other methylated melamine resins, “Nicarax MX-45”, “Nicarac MX- Mixed etherified melamine resin such as "410".

  As the crosslinking agent [II], one selected from these may be used, or two or more may be used in combination.

The content of the crosslinking agent [II] can be appropriately selected depending on the amount of the functional group contained in the polyester resin [I], the molecular weight of the polyester resin [I], and the purpose of use. I] The amount is preferably 1 to 40 parts by weight, particularly 3 to 30 parts by weight, and more preferably 5 to 25 parts by weight with respect to 100 parts by weight.
If the content is too large or too small, the adhesiveness tends to decrease.

The polyester resin composition of the present invention contains a polyester resin [I] and a crosslinking agent [II], and can take various forms such as liquid, granule, and powder.
In the polyester resin composition of the present invention, as necessary, antioxidants such as hindered phenols, heat stabilizers, glass fibers, inorganic / organic fillers, colorants, flame retardants, softeners, dispersants. , Wetting agents, emulsifiers, gelling agents, antifoaming agents, other thermoplastic resins, and the like can be contained to such an extent that the effects of the present invention are not impaired.
The polyester-based resin composition of the present invention can be used as molded articles such as films, sheets, cups, adhesives, paints, coating agents, and the like.

《Polyester aqueous liquid》
The polyester-based aqueous liquid of the present invention is obtained by dissolving or dispersing the polyester-based resin composition obtained as described above in an aqueous solvent. Hereinafter, dissolution or dispersion in an aqueous solvent is referred to as “water dissolution or dispersion”.
Usually, in order to dissolve or disperse in water to obtain a polyester-based aqueous liquid, the polyester-based resin [I] is neutralized with a neutralizing agent, dissolved or dispersed in an aqueous solvent, and blended with a crosslinking agent [II]. A method of using an aqueous system liquid is preferred. In addition, a method in which a resin composition containing a polyester resin [I] and a crosslinking agent [II] is dissolved or dispersed in water to obtain a polyester aqueous liquid, or a crosslinking agent [II] is dispersed in water. There is also a method of blending the polyester resin [I] with an aqueous liquid.

  The neutralizing agent is not particularly limited as long as it can neutralize the carboxyl group of the polyester resin [I]. For example, a metal hydroxide such as lithium hydroxide, potassium hydroxide, sodium hydroxide, etc. Ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, iminobispropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, diethanolamine, triethanolamine, N, N-diethylethanolamine, N, N-dimethylethanol And organic amines such as amine, aminoethanolamine, morpholine, N-methylmorpholine and N-ethylmorpholine; and ammonia. One kind selected from these neutralizing agents may be used, or two or more kinds may be used in combination.

  Among these neutralizing agents, it is easy to volatilize when a film is obtained by drying, and the boiling point is preferably 150 ° C. or less from the viewpoint of water resistance of the obtained film. In particular, ammonia, diethylamine, and triethylamine are preferable from the viewpoint of high versatility, low boiling point, and easy volatilization during drying. Triethylamine and ammonia are particularly preferable in terms of particularly excellent dispersion stability of the polyester resin [I]. preferable.

  Examples of the aqueous solvent include water or water mixed with an appropriate hydrophilic organic solvent. Examples of the hydrophilic organic solvent include ketones such as acetone; alcohols such as methanol, ethanol, and isopropyl alcohol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and ethylene glycol monotertiary butyl ether. The thing which can be mixed with water is mentioned. In particular, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monotertiary butyl ether, and isopropyl alcohol are preferably used. When using a hydrophilic organic solvent, the ratio with respect to the whole polyester-type aqueous liquid is set suitably. For example, although it can be set as a range of 0 to 20% by weight, the ratio of the hydrophilic organic solvent to the entire aqueous liquid is not limited to the above range. One kind selected from these aqueous solvents may be used, or two or more kinds may be used in combination.

  Moreover, surfactants, such as an anionic surfactant and a nonionic surfactant, can be mix | blended with this polyester-type aqueous liquid as needed. By blending the surfactant, the wettability to the polyester resin substrate can be improved when the polyester aqueous solution is applied to a polyester resin substrate such as a polyester film. As the surfactant, an appropriate one can be used, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, Examples thereof include alkylsulfosuccinate and dodecylbenzenesulfonate. One kind selected from these surfactants may be used, or two or more kinds may be used in combination.

  Moreover, you may mix | blend an antistatic agent, a filler, a ultraviolet absorber, a lubricant, a coloring agent, etc. with this polyester system aqueous liquid further as needed.

  The solid content concentration of the polyester-based aqueous liquid is appropriately adjusted so as to ensure good dispersibility of the polyester-based resin [I] and form a good film by coating film formation. 30% by weight is preferable, and 5 to 20% by weight is particularly preferable.

Next, a coated polyester film in which a coating functioning as a primer layer is formed on the surface of the polyester film using the polyester-based aqueous liquid of the present invention will be described.
A polyester-based aqueous liquid can be applied to a polyester film and heated to dry to form a film, thereby obtaining a coated polyester film. This coated polyester film may be further stretched.

  As the polyester film, a conventionally known appropriate material can be used, for example, polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and a copolymer obtained by copolymerizing these with other copolymerization components. A film can be mentioned. The polyester film may be either an unstretched film or a stretched film, but a stretched film is preferably used, and a biaxially stretched film is particularly desirable.

As this polyester film, one produced by a conventionally known appropriate technique can be used. For example, an unstretched polyester film can be obtained by melting a raw material polyester, extruding it into a sheet, and cooling it with a cooling drum.
Moreover, after extending | stretching this unstretched polyester film to a uniaxial direction or a biaxial direction, it heat-sets, and also can give a uniaxially stretched film or a biaxially stretched film by performing a heat relaxation process as needed.

  Appropriate techniques can be employed for coating and forming the polyester-based aqueous liquid on the polyester film. At this time, for example, after applying a polyester-based aqueous liquid on one or both sides of an unstretched film or a uniaxially stretched film by an appropriate method such as kiss coating, reverse coating, gravure coating, die coating, etc., and heating and drying to form a film The film can be stretched to form a biaxially stretched film. In addition, a polyester-based aqueous liquid can be applied to the secondary stretched film by an appropriate method, followed by heat drying to form a film. The coating amount of the polyester aqueous liquid at this time is appropriately set. For example, the thickness of the dry coating film is preferably 0.01 to 5 μm, particularly 0.01 to 2 μm, more preferably 0.01 to 1 μm, Is preferably in the range of 0.05 to 0.15 μm.

  The coated polyester film thus obtained is excellent in adhesion between a polyester resin substrate and a hard coat layer formed from, for example, an active energy ray-curable resin composition, and has a high refractive index primer layer, etc. It is very useful as a material for forming the coating film. Accordingly, the coated polyester film has good visibility even when used for optical applications.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “%” and “parts” mean weight basis.

[Production Example 1]
<Production of polyester resin [I-1]>
Dimethyl terephthalate 570 parts (0.294 mol), dimethyl isophthalate 558 parts (0.287 mol), dimethyl sodium 5-sulfoisophthalate 17 parts (0.006), bis (4- (2-hydroxyethoxy) phenyl ) 2574 parts (0.587 mol) of fluorene, 221 parts (0.208 mol) of diethylene glycol, 94 parts (0.005 mol) of polyethylene glycol having a number average molecular weight of 2,000, an acrylic resin “UC-3510 having a carboxyl group” ”(Manufactured by Toagosei Co., Ltd., acid value 80 mg KOH / g, weight average molecular weight 2,000, glass transition temperature −56 ° C.) 458 parts, tetrabutoxy titanium 0.7 parts as catalyst, zinc acetate dihydrate 0.5 And 4.6 parts of tertiary butyl catechol as a polymerization inhibitor in a transesterification reactor. Viewed under a nitrogen atmosphere, the temperature was raised over a period of 2 hours 180 ° C. to 250 ° C., distill the methanol to carry out an ester exchange reaction at 250 ° C. until the end.
Subsequently, after cooling to 180 ° C., 465 parts (0.176 mol) of 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride as a carboxylic anhydride. ) And the reaction was allowed to proceed at 180 ° C. for 1.5 hours under normal pressure to advance the chain extension to obtain a polyester resin [I-1]. The composition of this polyester resin is shown in Table 1.
In Table 1, the numerical value of each compound in the column of the polyol component (A) and the polyvalent carboxylic acid component (B) represents the molar fraction of the compound with respect to the component (A) or the component (B), and ester forming properties. The numerical value of the compound in the column of functional group containing acrylic resin (C) shows content (weight%) of acrylic resin (C) with respect to the whole polyester resin.

[Production Examples 2 to 5]
<Production of polyester resins [I-2] to [I-5]>
As shown in Table 1, polyester resins [I-2] to [I-5] were produced in the same manner as in Production Example 1 except that the copolymerization component and the ratio thereof were changed.

[Production Example 6]
<Production of polyester resin [I-6]>
863 parts of dimethyl 2,6-naphthalenedicarboxylate (0.353 mol), 615 parts of sodium dimethyl 5-sulfoisophthalate (0.208 mol), 2066 parts of bis (4- (2-hydroxyethoxy) phenyl) fluorene (0 .471 mol), 383 parts (0.617 mol) of ethylene glycol, 673 parts (0.034) of polyethylene glycol having a number average molecular weight of 2,000, an acrylic resin “UC-3510” having a carboxyl group (Toagosei Co., Ltd.) Manufactured, acid value 80 mg KOH / g, weight average molecular weight 2,000) 432 parts, tetrabutoxy titanium 0.7 parts, zinc acetate dihydrate 0.5 parts as a catalyst, tertiary butyl catechol 4.3 as a polymerization inhibitor Charge the transesterification reactor to 180 ° C to 240 ° C for 2 hours under a nitrogen atmosphere. Heated Te, distill the methanol to carry out an ester exchange reaction at 240 ° C. until the end.
Next, the pressure inside the system was gradually reduced at 240 ° C., and an attempt was made to proceed with the polycondensation reaction. . Therefore, no further evaluation was performed.

The abbreviations shown in Table 1 represent the following compounds.
BPEF: bis (4- (2-hydroxyethoxy) phenyl) fluorene DEG: diethylene glycol PEG-0.6K: polyethylene glycol having a number average molecular weight of 600 PEG-2K: polyethylene glycol having a number average molecular weight of 2,000 PEG-3.4K: Polyethylene glycol having a number average molecular weight of 3,400

DMT: dimethyl terephthalate DMI: dimethyl isophthalate SIPM: sodium dimethyl 5-sulfoisophthalate SuAn: succinic anhydride B-4400: 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1 , 2-Dicarboxylic anhydride

UC-3000: Acrylic resin “UC-3000” having a carboxyl group (manufactured by Toagosei Co., Ltd., acid value 86 mgKOH / g, weight average molecular weight 10,000, glass transition temperature 66 ° C., functional group content 15.3)
UC-3510: Acrylic resin having a carboxyl group “UC-3510” (manufactured by Toagosei Co., Ltd., acid value 80 mg KOH / g, weight average molecular weight 2,000, glass transition temperature −56 ° C., functional group content 2.9) )

The functional group content was calculated according to the following formula.
[formula]
Functional group moles per gram of acrylic resin x weight average molecular weight

  The physical properties of the polyester resins [I-1] to [I-5] thus obtained were measured according to the following methods, and the results are shown in Table 2.

[Glass transition temperature (Tg)]
Measurement was performed using a differential scanning calorimeter DSC Q20 manufactured by TA Instruments.

[Acid value]
0.5 g of a polyester-based resin was dissolved in a 7/3 (toluene / methanol) mixed solvent of toluene and methanol, and obtained by neutralization titration based on JIS K0070.

(Weight average molecular weight)
GPC measurement was performed using HLC-8320 manufactured by Tosoh Corporation, and it was determined from polystyrene conversion.

[Refractive index]
The refractive index with respect to the D line (589 nm) at 25 ° C. was measured using an Abbe refracting system DR-M4 manufactured by Atago.

[Examples 1-5 and Comparative Examples 1-5]
<Preparation of polyester aqueous liquid>
For polyester resins [I-1] to [I-5] obtained in Production Examples 1 to 5, 70 parts of polyester resin, 823 parts of water, 100 parts of isopropyl alcohol, and 7 parts of 25% aqueous ammonia are used as a reactor. The resulting mixture was heated to 90 ° C. and dissolved while stirring to prepare an aqueous polyester resin liquid (aqueous dispersion) having a solid content concentration of 7% (wt%).

Thus, the polyester-type resin aqueous liquid obtained was mix | blended with the ratio shown in Table 3, and the polyester-type aqueous liquid of Examples 1-5 and Comparative Examples 1-5 was obtained.
In Table 3, the numerical values in the column of parts by weight of the polyester resin and the crosslinking agent represent values converted into the solid content of the polyester resin and the effective component amount of the crosslinking agent.

The crosslinking agents II-1 and II-2 shown in Table 3 are as follows.
II-1: Epoxy crosslinking agent “Denacol EX-810” (manufactured by Nagase ChemteX Corporation)
II-2: Oxazoline-based crosslinking agent “Epocross WS-700” (manufactured by Nippon Shokubai Co., Ltd.)

  The polyester-based aqueous liquid thus obtained was used to evaluate the adhesion with the hard coat layer according to the following method. The results are shown in Table 3.

〔Adhesiveness〕
The polyester-based aqueous liquids obtained in the examples and comparative examples were placed on a PET film (Toray Industries, Lumirror T60, thickness 100 μm) with a bar coater No. The primer layer having a thickness of 1 μm was formed by coating at 6 and drying at 150 ° C. for 3 minutes.
Next, an ultraviolet curable resin composition comprising the following blending components was placed on the primer layer with a bar coater no. 10 and dried at 60 ° C. for 3 minutes. Subsequently, the ultraviolet curable resin composition was cured by irradiating with ultraviolet light at 450 mJ / cm ² using a metal halide lamp having an irradiation intensity of 80 W / cm set at a height of 13 cm from the coated surface, and the thickness was 3.5 μm. A hard coat layer was formed.
<Ultraviolet curable resin composition>
Mixture containing urethane acrylate compound for hard coat: 220 parts Isopropyl alcohol: 725 parts Methyl isobutyl ketone: 55 parts Photopolymerization initiator “Irgacure-184” (manufactured by Ciba Specialty Chemicals): 8.8 parts

(Urethane acrylate compound-containing mixture for hard coat)
In a four-necked flask equipped with a thermometer, stirrer, water-cooled condenser, nitrogen gas inlet, isophorone diisocyanate 15 g (0.07 mol), a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value 116 mg KOH / g) 85 g, 2,6-di-tert-butylcresol 0.06 g as a polymerization inhibitor, 0.02 g of dibutyltin dilaurate as a reaction catalyst, reacted at 60 ° C., and when the residual isocyanate group became 0.3% or less Then, the reaction was terminated to obtain a mixture of 51.1 g of urethane acrylate compound (weight average molecular weight 1,200), 16.3 g of pentaerythritol triacrylate, and 32.6 g of pentaerythritol tetraacrylate.

After putting 100 pieces of 1 mm ² crosscuts on the hard coat layer formed in this way, and attaching Nichiban's cello tape (registered trademark) on it, and rubbing the tape with a plastic eraser to ensure sufficient adhesion The adhesiveness was evaluated based on the number of the hard coat layers that were rapidly peeled off in the 90 ° direction. ◎ and ○ were considered good adhesion.

A: 98/100 or more (remaining number / measured number)
○: 85/100 or more, less than 98/100 Δ: 60/100 or more, less than 85/100 x: less than 60/100

  From the above results, the polyester resin [I] and the crosslinking agent [II] containing the acrylic resin (C) having an ester-forming functional group and the carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures. It can be seen that the polyester-based aqueous liquids of Examples 1 to 5 have good adhesion between the polyester-based resin substrate and the hard coat layer while having a high refractive index and a high glass transition temperature.

  On the other hand, Comparative Examples 1, 2, and 3 not containing the crosslinking agent [II], Comparative Example 4 not containing the acrylic resin (C) having an ester-forming functional group, and acrylic having an ester-forming functional group In Comparative Example 5 which does not contain both the resin (C) and the crosslinking agent [II], the adhesion between the polyester resin substrate and the hard coat layer was insufficient. In addition, a polyester resin not containing a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures is prone to foaming immediately after the start of pressure reduction during polycondensation, and the liquid level rapidly rises. could not.

  The polyester resin composition of the present invention can be suitably used as a primer for a polyester film on which a hard coat layer or the like is laminated. In particular, the polyester resin composition of the present invention can secure the adhesion between the polyester resin substrate and the hard coat layer while maintaining a high refractive index, and therefore can suppress iris-like reflection. It can be suitably used for applications requiring design properties.

Claims (11)

Polyester resin [I] comprising a polyol component (A), a polyvalent carboxylic acid component (B) and an acrylic resin (C) having an ester-forming functional group, and a polyester resin comprising a crosslinking agent [II] A composition,
A polyester resin composition comprising a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures as the polyvalent carboxylic acid component (B).   Polyester resin [I] is a hydroxyl group-containing prepolymer comprising a polyol component (A), a polyvalent carboxylic acid component (B) and an acrylic resin (C) having an ester-forming functional group, and a carboxylic anhydride structure. The polyester-based resin composition according to claim 1, wherein the polyester-based resin composition is formed by chain extension with two or more carboxylic acid anhydrides (b1).   The polyester polyol [I] is a polyester polyol composed of a polyol component (A) and a polyvalent carboxylic acid component (B), and the chain is extended with a carboxylic acid anhydride (b1) having two or more carboxylic acid anhydride structures. 2. The polyester resin composition according to claim 1, which is obtained by reacting an acrylic resin (C) having an ester-forming functional group.   The polyester-based resin composition according to any one of claims 1 to 3, comprising a polyalkylene glycol (a1) having a number average molecular weight of 1,000 or more as the polyol component (A).   5. The polyester resin composition according to claim 4, comprising 0.01 to 10 mol% of a polyalkylene glycol (a1) having a number average molecular weight of 1,000 or more based on the whole polyol component (A). The polyester resin composition according to any one of claims 1 to 5, comprising a fluorene compound (a2) represented by the following general formula (1) as the polyol component (A).

In [Equation (1), _{R 1} is an alkylene _{group, R 2, R 3, R} 4 and _{R 5} are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group or an aralkyl group having 1 to 5 carbon atoms These may be the same as or different from each other. ]   The acrylic resin (C) having an ester-forming functional group is a carboxyl group-containing acrylic resin (c1), a hydroxyl group-containing acrylic resin (c2), a glycidyl group-containing acrylic resin (c3), or an alkoxysilyl group-containing acrylic system. It is resin (c4), The polyester-type resin composition in any one of Claims 1-6 characterized by the above-mentioned.   The polyester resin composition according to any one of claims 1 to 7, wherein the polyester resin [I] has a refractive index of 1.56 or more.   The polyester resin composition according to any one of claims 1 to 8, wherein the crosslinking agent [II] contains a functional group having reactivity with a carboxyl group.   The polyester resin composition according to any one of claims 1 to 9, wherein the crosslinking agent [II] is a melamine compound or a compound having an epoxy group, an oxazoline group or a carbodiimide group.   A polyester-based aqueous liquid, wherein the polyester-based resin composition according to claim 1 is dissolved or dispersed in an aqueous solvent.