阅读说明：本技术 聚酯树脂、聚酯树脂水分散体和聚酯树脂水分散体的制造方法 (Polyester resin, aqueous polyester resin dispersion, and method for producing aqueous polyester resin dispersion ) 是由 渡边奈穗子 山本佑 田中秀树 于 2018-11-27 设计创作，主要内容包括：提供不使用乳化剂和有机溶剂就能形成水系乳液的具有自乳化功能的聚酯树脂、含有其的水分散体、水性胶粘剂和水性墨及由其形成的层叠体,包装材料以及水分散体的制造方法。以下述通式(1)的化学结构所示,酸值250～2,500eq/10<Sup>6</Sup>g,数均分子量2,000～50,000的聚酯树脂。(X-O)<Sub>r</Sub>-W-(O-(CO-Z-CO-O-Y-O)<Sub>p</Sub>-X)<Sub>q</Sub>···(1)其中,W为(q+r)价的有机基团,(CO-Z-CO-O-Y-O)为以多元羧酸成分Z和多元醇成分Y为聚合成分的聚酯树脂骨架,X为具有2个以上羧基的多元酸的残基或氢(其中,(q+r)个X不全为氢)。X,Y和Z各自可相同或不同,在同一重复单元中也可以相同或不同。p的平均值为3以上,q的平均值为大于0、15以下,r的平均值为0以上,不足15,(q+r)为3以上、15以下。(Provided are a polyester resin having a self-emulsifying function which can form an aqueous emulsion without using an emulsifier and an organic solvent, an aqueous dispersion containing the same, an aqueous adhesive, an aqueous ink, a laminate formed from the aqueous adhesive and the aqueous ink, a packaging material, and a method for producing the aqueous dispersion. The acid value is 250 to 2,500eq/10, as shown by the chemical structure of the following general formula (1) 6 g, a polyester resin having a number average molecular weight of 2,000 to 50,000. (X-O) r ‑W‑(O‑(CO‑Z‑CO‑O‑Y‑O) p ‑X) q In the formula (1), W is an organic group having a valence of (q + r), (CO-Z-CO-O-Y-O) is a polyester resin skeleton having a polycarboxylic acid component Z and a polyol component Y as polymerization components, and X is a residue of a polybasic acid having 2 or more carboxyl groups or hydrogen (wherein (q + r) X's are not all hydrogen). X, Y and Z may be the same or different and may be the same or different in the same repeating unit. The average value of p is 3 or more, the average value of q is more than 0 and 15 or less, the average value of r is 0 or more and less than 15, and (q + r) is 3 or more and 15 or less.)

1. A polyester resin represented by the following general formula (1),

the acid value is 250 to 2,500eq/10⁶g，

A number average molecular weight of 2,000 to 50,000,

(X-O)_r-W-(O-(CO-Z-CO-O-Y-O)_p-X)_q···(1)

wherein W is an organic group having a valence of q + r, CO-Z-CO-O-Y-O is a polyester resin skeleton having a polycarboxylic acid component Z and a polyol component Y as polymerization components, and X is a residue of a polybasic acid having 2 or more carboxyl groups or hydrogen, wherein q + r X's are not all hydrogen; x, Y and Z may be the same or different and may be the same or different in the same repeating unit; the average value of p is 3 or more, the average value of q is more than 0 and 15 or less, the average value of r is 0 or more and less than 15, and q + r is 3 or more and 15 or less.

2. The polyester resin according to claim 1, wherein W in the general formula (1) is a residue of a polyol having q + r hydroxyl groups.

3. The polyester resin according to any one of claims 1 to 2, wherein W in the general formula (1) is at least 1 residue selected from the group consisting of a pentaerythritol residue, a sorbitol residue and an inositol residue.

4. The polyester resin according to any one of claims 1 to 3, wherein X in the general formula (1) is a residue of at least one kind selected from the group consisting of trimellitic anhydride, succinic anhydride and maleic anhydride.

5. An aqueous polyester resin dispersion comprising the polyester resin according to any one of claims 1 to 4, an alkali compound and water.

6. The aqueous polyester resin dispersion according to claim 5, wherein the aqueous polyester resin dispersion is emulsifier-free.

7. The aqueous polyester resin dispersion according to claim 5 or 6, wherein the aqueous polyester resin dispersion is free of organic solvents.

8. A method for producing a polyester resin aqueous dispersion, comprising the steps of: mixing the polyester resin according to any one of claims 1 to 4, an alkaline compound and water without adding an emulsifier and an organic solvent to obtain a polyester resin aqueous dispersion.

9. The aqueous polyester resin dispersion according to any one of claims 5 to 7, further comprising a curing agent.

10. The aqueous polyester resin dispersion according to claim 9, wherein the curing agent is 1 or 2 or more selected from the group consisting of a polyvalent epoxy compound, an oxazoline resin, a carbodiimide resin, an isocyanate compound, a melamine resin and a polyvalent metal salt.

11. An aqueous adhesive comprising the aqueous polyester resin dispersion of claim 9 or 10.

12. An aqueous coating material comprising the aqueous polyester resin dispersion of claim 9 or 10.

13. An aqueous ink comprising the aqueous polyester resin dispersion according to claim 9 or 10 and a colorant.

14. A laminate comprising an A layer and a B layer; the layer A is a layer containing the polyester resin according to any one of claims 1 to 4, and the layer B is a layer composed of a film, a sheet, a woven fabric, a nonwoven fabric or paper.

15. A packaging material comprising the laminate according to claim 14 as a constituent element.

Technical Field

The present invention relates to a polyester resin having a self-emulsifying function which can form a stable aqueous emulsion without using an emulsifier and an organic solvent, a polyester resin aqueous dispersion containing the same, and a method for producing the aqueous dispersion.

Background

Polyester resins are widely used as raw materials for resin compositions used for paints, coating agents, adhesives, and the like. The polyester resin is generally composed of a polycarboxylic acid and a polyhydric alcohol. The selection and combination of the polycarboxylic acid and the polyhydric alcohol, and the molecular weight can be freely controlled, and the obtained polyester resin can be used for various applications such as coating applications and adhesive applications.

In recent years, various treatment agents such as paints, inks, coating agents, adhesives, sealants, primers, fiber products, and paper products have been advancing from conventional organic solvent systems toward water systems, high solid-state products, and powder products from the viewpoint of environmental problems and suppression of discharge of volatile organic solvents. In particular, the aqueous dispersion is expected to be the most versatile in terms of satisfactory workability and improvement of working environment.

Examples of the use of a polyester resin dispersed in water as a binder component include patent documents 1 to 4. In patent document 1, an aqueous dispersion forcibly emulsified by an emulsifier is used. Patent documents 2 and 3 disclose that a copolyester having a segment containing a sulfonic acid metal salt group in the molecule has a self-emulsifying function of forming a stable aqueous emulsion without adding an emulsifier. Patent document 4 discloses a method for producing self-dispersible particles by reacting a lactic acid polymer with a polycarboxylic acid or an acid anhydride thereof and adding a base and water.

Disclosure of Invention

Problems to be solved by the invention

The present inventors have found that the above-mentioned background art has a problem when they studied. That is, in the invention disclosed in patent document 1, since an emulsifier is used in the preparation of the resin aqueous dispersion, when the emulsifier is used as a binder component, the emulsifier remains at the interface between the resin and the adherend, and the adhesiveness is lowered. In the invention disclosed in patent document 2, stable water dispersion can be obtained without using an emulsifier, and when used as a binder component, high adhesiveness is exhibited, but in order to impart excellent solubility or dispersibility to water, a large amount of the hydrophilic material needs to be used, and therefore the water resistance of the obtained coating film is very poor. In the invention disclosed in patent document 3, the solvent removal operation is performed in the production process of the aqueous dispersion, and there is room for improvement from the viewpoint of suppressing the discharge of the volatile organic solvent. Further, the invention disclosed in patent document 4 has a problem that introduction of a polylactic acid-based skeleton having high hydrolysis resistance does not allow use in applications requiring high hydrolysis resistance. There is also a problem that polylactic acid is thermally deteriorated at 180 ℃ or higher to lower the molecular weight, and thus it is difficult to develop the use for which heat resistance is required.

The present invention is based on the problems of the prior art. That is, an object to be solved by the present invention is to provide a polyester resin which has excellent heat resistance as compared with polylactic acid and has a self-emulsifying function of forming an aqueous emulsion without using an emulsifier or an organic solvent. Further, a water dispersion, an aqueous adhesive, an aqueous ink containing the polyester resin, a laminate, a packaging material, and a method for producing the water dispersion are provided.

Means for solving the problems

The present inventors have earnestly studied and, as a result, have found that the above-mentioned problems can be solved by the means shown below, and have reached the present invention. Namely, the present invention is constituted as follows.

<1>

An acid value of 250 to 2,500eq/10, represented by the chemical structure of the following general formula (1)⁶g. A polyester resin having a number average molecular weight of 2,000 to 50,000.

(X-O)_r-W-(O-(CO-Z-CO-O-Y-O)_p-X)_q···(1)

Wherein W is an (q + r) -valent organic group, (CO-Z-CO-O-Y-O) is a polyester resin skeleton having a polycarboxylic acid component Z and a polyol component Y as polymerization components, and X is a residue of a polybasic acid having 2 or more carboxyl groups or hydrogen (wherein, q + r X is not all hydrogen). X, Y and Z may be the same or different, respectively, and may be the same or different in the same repeating unit. The average value of p is 3 or more, the average value of q is more than 0 and 15 or less, the average value of r is 0 or more and less than 15, and (q + r) is 3 or more and 15 or less.

<2>

The polyester resin according to <1>, wherein W in the general formula (1) is a residue of a polyhydric alcohol having (q + r) hydroxyl groups.

<3>

The polyester resin according to any one of <1> to <2>, wherein W in the general formula (1) is at least 1 residue selected from the group consisting of a pentaerythritol residue, a sorbitol residue and an inositol residue.

<4>

The polyester resin according to any one of <1> to <3>, wherein X in the general formula (1) is any 1 or more residues selected from the group consisting of trimellitic anhydride, succinic anhydride, and maleic anhydride.

<5>

An aqueous polyester resin dispersion comprising the polyester resin according to any one of <1> to <4>, an alkaline compound and water.

<6>

The aqueous polyester resin dispersion according to <5>, which is characterized by being free of an emulsifier.

<7>

The aqueous polyester resin dispersion according to <5> or <6>, characterized by being free of organic solvents.

<8>

A method for producing a polyester resin aqueous dispersion, comprising the steps of: the polyester resin according to any one of <1> to <4>, an alkaline compound and water are mixed without adding an emulsifier and an organic solvent to obtain a polyester resin aqueous dispersion.

<9>

The aqueous polyester resin dispersion according to any one of <5> to <7>, which further contains a curing agent.

<10>

The polyester resin aqueous dispersion according to <9>, wherein the curing agent is 1 or 2 or more selected from the group consisting of a polyvalent epoxy compound, an oxazoline resin, a carbodiimide resin, an isocyanate compound, a melamine resin and a polyvalent metal salt.

<11>

An aqueous adhesive comprising an aqueous polyester resin dispersion of <9> or <10 >.

<12>

An aqueous coating material comprising an aqueous polyester resin dispersion of <9> or <10 >.

<13>

An aqueous ink comprising an aqueous polyester resin dispersion of <9> or <10> and a colorant.

<14>

A laminate, comprising: a layer (layer A) comprising the polyester resin according to any one of <1> to <4> and a layer (layer B) comprising a film, a sheet, a woven fabric, a nonwoven fabric or paper.

<15>

A packaging material comprising the laminate according to <14 >.

ADVANTAGEOUS EFFECTS OF INVENTION

The polyester resin of the present invention has a high concentration of carboxyl groups in the molecular chain, and thus exhibits excellent water dispersibility as follows: an aqueous dispersion can be easily formed by merely stirring with an aqueous solution of a basic compound without using an emulsifier and an organic solvent. Further, the aqueous polyester resin dispersion of the present invention can be prepared without using an emulsifier, and thus is excellent in adhesiveness. Further, by mixing a curing agent reactive with a carboxyl group in the polyester resin aqueous dispersion of the present invention, an adhesive layer and ink having excellent adhesiveness and water resistance can be easily obtained. Further, the polyester resin of the present invention is superior to polylactic acid in heat resistance.

Detailed Description

A polyester resin represented by the chemical structure of the following general formula (1),

the acid value is 250 to 2,500eq/10⁶g. The number average molecular weight is 2,000 to 50,000.

(X-O)_r-W-(O-(CO-Z-CO-O-Y-O)_p-X)_q···(1)

Wherein W is an (q + r) -valent organic group, (CO-Z-CO-O-Y-O) is a polyester resin skeleton having a polycarboxylic acid component Z and a polyol component Y as polymerization components, and X is a residue of a polybasic acid having 2 or more carboxyl groups or hydrogen (wherein, q + r X is not all hydrogen). X, Y and Z may be the same or different and may be the same or different in the same repeating unit. The average value of p is 3 or more, the average value of q is more than 0 and 15 or less, the average value of r is 0 or more and less than 15, and (q + r) is 3 or more and 15 or less. That is, the polyester resin of the present invention is a polyester resin whose terminal is modified with X.

The acid value of the polyester resin of the present invention was 250eq/10⁶g is more than 2500eq/10⁶g is less, preferably 300eq/10⁶g is more than 2300eq/10⁶g is below. The acid value of the polyester resin of the present invention is mainly derived from a large amount of carboxyl groups contained at the molecular chain terminals, and exhibits a property of forming an aqueous dispersion without separately adding an organic solvent and an emulsifier (hereinafter referred to as self-emulsifiability), and further exhibits an effect of forming emulsion particles having a small particle diameter. When the acid value of the polyester resin is not less than the lower limit, self-emulsifiability can be exhibited and curability of the cured coating film can be improved. On the other hand, if the amount is less than the upper limit, hydrolysis is less likely to occur even in the solid resin state, and the storage stability is good. Further, the cured coating film using the polyester resin of the present invention is also excellent in water resistance.

The number average molecular weight of the polyester resin of the present invention is 2,000 to 50,000, preferably 3,000 to 45,000, and more preferably 4,000 to 40,000. When the number average molecular weight is not less than the lower limit, the cohesive force of the polyester resin is not excessively small, and the adhesiveness and water resistance are good. On the other hand, when the number average molecular weight is not more than the upper limit, the cohesive force of the polyester resin is not excessively large, and the water dispersibility is good. Therefore, not only a method of dissolving in a solvent and transferring to an aqueous phase, but also a method of directly mixing only a basic compound and water to prepare an aqueous dispersion, an aqueous dispersion having a good water dispersibility without coarse particle size and particle precipitation can be obtained.

In the polyester resin of the present invention, (CO-Z-CO-O-Y-O) is obtained by polycondensation of a plurality of monomers comprising a polycarboxylic acid component Z having a valence of 2 or more and a polyol component Y having a valence of 2 or more (hereinafter also referred to as polyester resin (A)), and a polymerization method is not particularly limited, and a known method can be used.

In the polycondensation of the polyester resin (A), a polymerization catalyst may be used. Examples of the polymerization catalyst include titanium compounds (e.g., tetra-n-butyl titanate, tetra-isopropyl titanate, titanyl acetylacetonate), antimony compounds (e.g., tributoxyantimony, and diantimony trioxide), germanium compounds (e.g., tetra-n-butoxygermanium and germanium oxide), zinc compounds (e.g., zinc acetate), and aluminum compounds (e.g., aluminum acetate and aluminum acetoacetate). The polymerization catalyst may be used in 1 or 2 or more species. The titanium compound is preferable in view of polymerization reactivity.

The polycarboxylic acid component Z having a valence of 2 or more is preferably an aromatic polycarboxylic acid, an aliphatic polycarboxylic acid or an alicyclic polycarboxylic acid. Examples of the alicyclic polycarboxylic acid include alicyclic dicarboxylic acids such as 1, 4-cyclohexanedicarboxylic acid, 1, 3-cyclohexanedicarboxylic acid, 1, 2-cyclohexanedicarboxylic acid, and anhydrides thereof. Examples of the aliphatic polycarboxylic acid include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid. Examples of the aromatic polycarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, bibenzoic acid, and 5-hydroxyisophthalic acid. Further, examples thereof include aromatic dicarboxylic acids having a sulfonic acid group or a sulfonate group such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2, 7-dicarboxylic acid, 5- (4-sulfophenoxy) isophthalic acid, sulfoterephthalic acid and/or metal salts and ammonium salts thereof. Among them, 1 or 2 or more species can be selected for use. Aromatic dicarboxylic acids or aliphatic dicarboxylic acids are preferred, among which terephthalic acid, isophthalic acid, adipic acid or sebacic acid are preferred.

The polyhydric alcohol component Y having a valence of 2 or more is preferably an aliphatic diol, an alicyclic diol, an ether bond-containing diol or an aromatic diol. Examples of the aliphatic diol include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 2-methyl-1, 3-propanediol, neopentyl glycol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 2-ethyl-2-butylpropanediol, hydroxypivalyl hydroxypivalate, dimethylolheptane, 2, 4-trimethyl-1, 3-pentanediol and the like. Examples of the alicyclic diol include 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, tricyclodecanediol, tricyclodecanedimethanol, spiroglycol, hydrogenated bisphenol A, and ethylene oxide and propylene oxide adducts of hydrogenated bisphenol A. As examples of the ether bond-containing diol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, a neopentyl glycol ethylene oxide adduct or a neopentyl glycol propylene oxide adduct may also be used as necessary. Examples of the aromatic diol include diols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to 2 phenolic hydroxyl groups of bisphenols, such as p-xylene glycol, m-xylene glycol, o-xylene glycol, 1, 4-phenylene glycol, ethylene oxide adducts of 1, 4-phenylene glycol, bisphenol a, ethylene oxide adducts of bisphenol a, and propylene oxide adducts. Among them, 1 or 2 or more species can be selected for use. Aliphatic diols or diols containing an ether bond are preferred, among which ethylene glycol, 1, 4-butanediol or diethylene glycol is preferred. In the polyester resin (a), the total amount of the aliphatic diol and the ether bond-containing diol is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and may be 100 mol% based on 100 mol% of the total polyol component. If the total content of the aliphatic diol and the ether bond-containing diol is too small, the water dispersibility and the adhesiveness may be deteriorated.

Examples of the 3-or more-functional polycarboxylic acid constituting the polyester resin (a) in the present invention include trimellitic acid, pyromellitic acid, methylcyclohexene tricarboxylic acid, Oxydiphthalic Dianhydride (ODPA), 3',4,4' -benzophenonetetracarboxylic dianhydride (BTDA), 3',4,4' -diphenyltetracarboxylic dianhydride (BPDA), 3',4,4' -diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'- (hexafluoroisopropylene) diphthalic dianhydride (6FDA), and 2,2' -bis [ (dicarboxyphenoxy) phenyl ] propane dianhydride (BSAA). Examples of the 3-or more-functional polyol constituting the polyester resin (a) of the present invention include glycerin, pentaerythritol, trimethylolethane, trimethylolpentane, and trimethylolpropane. Among them, 1 or 2 or more species can be selected for use. In the polyester resin (a), the amount of the 3-functional or higher polycarboxylic acid is preferably 10 mol% or less, more preferably 8 mol% or less, further preferably 5 mol% or less, and may be 0 mol% based on 100 mol% of the total polycarboxylic acid components. When the amount is too large, the polyester resin (A) is gelled.

In the polyester resin of the present invention, W is an organic group having a valence of (q + r). (q + r) is 3 or more, preferably 4 or more. When (q + r) is not less than the above value, the number of carboxyl groups in the polyester resin is not too small, and water dispersion is easy. Further, (q + r) is 15 or less, preferably 10 or less, more preferably 8 or less. When (q + r) is less than the above value, the number of carboxyl groups in the polyester resin is not too large, and the storage stability is good.

When the polyester resin is a mixture of 2 or more species, q is an average value of the mixture. The average value of q needs to be greater than 0. Preferably 1 or more, more preferably 2 or more, further preferably 3 or more, and particularly preferably 4 or more. Further, the content is 15 or less, preferably 13 or less, more preferably 10 or less, further preferably 8 or less, and particularly preferably 6 or less. In order to set the average value of q within the above range, q of each polyester resin is preferably an integer of 1 or more, more preferably 2 or more, further preferably 3 or more, and particularly preferably 4 or more. Further, it is preferably 20 or less, more preferably 18 or less, and further preferably 15 or less.

The average value of q means the average value of the number of adducts (CO-Z-CO-O-Y-O) in W, for example, in the polyester resin, the number of adducts (CO-Z-CO-O-Y-O) is 50 mol% for 10 compounds, 30 mol% for 8 compounds, and 8.6 for 20 compounds, the average value of q is 8.6, the formula is calculated as follows, the average value of q is (10 × 50 mol% +8 × 30 mol% +6 × 20 mol%)/100 mol%/8.6.

When the polyester resin is a mixture of 2 or more species, r is an average value of the mixture. The average value of r is 0 or more, preferably 1 or more, more preferably 2 or more, and further preferably 3 or more. Further, the content is less than 15, preferably 13 or less, more preferably 10 or less, further preferably 8 or less, and particularly preferably 6 or less. In order to set the average value of r within the above range, r of each polyester resin is preferably 0 or more, more preferably 1 or more, and further preferably 2 or more. Further, it is preferably 20 or less, more preferably 18 or less, and further preferably 15 or less.

The average value of r is an average value of the number of adducts (X-O) in W, for example, in a polyester resin, the number of adducts (X-O) is 50 mol% for 10 compounds, 30 mol% for 8 compounds, and 8.6 for 20 mol% for 6 compounds, and the average value of q is 8.6, the formula is calculated as follows, and the average value of r is (10 × 50 mol% +8 × 30 mol% +6 × 20 mol%)/100 mol%/8.6.

W is not particularly limited, and examples thereof include polyols having 3 or more hydroxyl groups and derivatives thereof. Examples of the polyhydric alcohol having 3 hydroxyl groups include trimethylolpropane, glycerol, and 1,3, 5-cyclohexanetriol. Examples of the polyhydric alcohol having 4 or more hydroxyl groups include pentaerythritol, dipentaerythritol, diglycerin, polyglycerol, xylitol, sorbitol, glucose, fructose, mannose, and the like. These polyols may be used alone or in combination of 2 or more. Among them, trimethylolpropane, pentaerythritol and sorbitol have 2 or more hydroxyl groups of the 1 st order, and further have a large number of hydroxyl groups, and thus are preferable. When the hydroxyl group contained in W is large, a multi-branched skeleton is easily formed, and thus a large amount of carboxyl group is introduced by acid addition, whereby the acid value can be increased. Therefore, it is preferable to easily combine the resin strength and the water dispersibility.

When 2 or more polyols having different valence of organic group are used as W, the average value of the valence W of organic group is (q + r). for example, in 100 mol% W, 30 mol% of organic group having valence of 8, 50 mol% of organic group having valence of 5, and 5.5 mol% of organic group having valence of 3 are used as W, the formula is as follows.w (8-valent × 30 mol% + 5-valent × mol% + 3-valent × mol%)/100 mol%/5.5, that is, (q + r) in this case is 5.5.

When the polyester resin is a mixture of 2 or more species, p is an average value of the mixture. In the polyester resin of the present invention, the- (CO-Z-OC-O-Y-O)_pThe average value of p in (a) is 3 or more, preferably 4 or more, more preferably 5 or more. When the average value of p is not less than the above value, the number average molecular weight of the polyester resin can be prevented from being too small. Thereby maintaining the cohesion of the polyester resin and providing good adhesiveness and water resistance. In additionOn the other hand, the average value of p is preferably 50 or less, more preferably 40 or less, and still more preferably 30 or less. When the average value of p is not more than the above value, the number average molecular weight of the polyester resin can be prevented from becoming too large. This can suppress the cohesion of the polyester resin from becoming too large, and can ensure the concentration of X contained in the polyester resin. This also enables the acid value of the polyester resin to be within the above-specified range, and the water dispersibility to be good. In order to set the average value of p in the above range, p in each polyester resin is preferably an integer of 0 or more, more preferably 1 or more, further preferably 2 or more, and particularly preferably 3 or more. Further, it is preferably 60 or less, more preferably 50 or less, and further preferably 40 or less.

The average value of p is an average value of the repeating unit (CO-Z-CO-O-Y-O) in the polyester resin, for example, the average value of p in the case of 100 mol% of the polyester resin is 50 mol% for 10 compounds, 30 mol% for 8 compounds, and 20 mol% for 6 compounds is 8.6, and the average value of p is calculated as follows (10 × 50 mol% +8 × 30 mol% +6 × 20 mol%)/100 mol%/8.6.

The repeating units (CO-Z-CO-O-Y-O) may be continuous over 1 chain or may be dispersed over different chains. For example, when (q + r) is 4 and p is 15, the following formula (2) may have a structure in which q is 3 and r is 1, and 15 (CO-Z-CO-O-Y-O) are continuously present in 1 chain, or the following formula (3) may have a structure in which q is 4 and r is 0, and 2, 3, 4, and 6 (CO-Z-CO-O-Y-O) are unevenly added to 4 chains, respectively.

[ solution 1]

(X-O)₃-W-(O-(CO-Z-CO-O-Y-O)₁₅-X) formula (2)

[ solution 2]

In the polyester resin of the present invention, X is a residue of a polybasic acid having 2 or more carboxyl groups or hydrogen. Wherein (q + r) X's are not all hydrogen, and at least 1 is a residue of a polybasic acid having 2 or more carboxyl groups. Preferably, 25% or more of (q + r) X's are residues of a polybasic acid having 2 or more carboxyl groups, more preferably 50% or more are residues of a polybasic acid having 2 or more carboxyl groups, still more preferably 75% or more are residues of a polybasic acid having 2 or more carboxyl groups, particularly preferably 90% or more are residues of a polybasic acid having 2 or more carboxyl groups, and all X's may be residues of a polybasic acid having 2 or more carboxyl groups. X is preferably different from said Z.

Examples of the polybasic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid and anhydrides thereof, aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid and anhydrides thereof, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and terpene-maleic acid adducts and anhydrides thereof, alicyclic dicarboxylic acids such as 1, 4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydroisophthalic acid, and 1, 2-cyclohexene dicarboxylic acid, and anhydrides thereof, and carboxylic acids having a valence of 3 or more such as trimellitic acid and methylcyclohexene tricarboxylic acid and anhydrides thereof. Among them, trimellitic anhydride, succinic anhydride, and maleic anhydride are preferable, and trimellitic anhydride is particularly preferable because trimellitic anhydride can be easily reacted in addition reaction, and 2 carboxyl groups can be introduced per 1 molecule, so that a large amount of acid value can be introduced, and water dispersion is facilitated.

Further, as the polybasic acid, dianhydrides such as pyromellitic dianhydride (PMDA), Oxydiphthalic Dianhydride (ODPA), 3',4,4' -benzophenonetetracarboxylic dianhydride (BTDA), 3',4,4' -biphenyltetracarboxylic dianhydride (BPDA), ethylene glycol dianhydro Trimellitate (TMEG), 3',4,4' -diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'- (hexafluoroisopropylene) diphthalic dianhydride (6FDA), 2' -bis [ (dicarboxyphenoxy) phenyl ] propane dianhydride (BSAA), and glycerol trihydrate trimellitate may be used. In particular, the use of ethylene glycol dianhydro Trimellitate (TMEG) which can be subjected to addition reaction at a relatively low temperature, has a small cohesive force, and is excellent in water dispersibility is particularly preferable. The polybasic acids may be used alone or in combination of 2 or more.

The polyester resin of the present invention is not particularly limited, and for example, it can be produced by depolymerizing a polyester resin (a) obtained from a carboxylic acid component Z comprising a polyvalent carboxylic acid compound having a valence of 2 or more and a diol component Y comprising a polyvalent alcohol compound having a valence of 2 or more with a polyhydric alcohol W having 3 or more hydroxyl groups, and then reacting the terminal hydroxyl groups of the polyester resin (a) with a polybasic acid X to introduce a carboxyl group into the molecular terminal.

In order to prevent ring opening of the polybasic acid anhydride by reaction with water contained in the polymerization system, it is preferable that each raw material is subjected to vacuum drying or the like in advance to reduce the water content and then used. In order to avoid the influence of moisture during polymerization, it is preferable to carry out the polymerization in a vacuum or an inert gas atmosphere. Further, the polymerization rate can be increased by using a conventionally known acid addition catalyst. Amines such as triethylamine, benzyldimethylamine and the like; quaternary ammonium salts such as tetramethylammonium chloride and triethylbenzylammonium chloride; imidazoles such as 2-ethyl-4-imidazole; pyridines such as 4-dimethylaminopyridine; phosphines such as triphenylphosphine; phosphorus salts of tetraphenylphosphonium bromide and the like; sulfonium salts such as sodium p-toluenesulfonate; sulfonic acids such as p-toluenesulfonic acid; organic metal salts such as zinc octylate, etc., more preferably amines, pyridines and phosphines, and particularly, when 4-dimethylaminopyridine is used, the polymerization rate can be increased.

When the polyester resin of the present invention is polymerized, it is effective to add various antioxidants. When the polymerization temperature is high or the polymerization time is long, when a segment having low heat resistance such as polyether is copolymerized, oxidation deterioration may be easily caused, and in this case, the addition of an antioxidant is particularly effective. Examples of the antioxidant include known antioxidants such as phenol antioxidants, phosphorus antioxidants, amine antioxidants, sulfur antioxidants, nitro compound antioxidants, and inorganic compound antioxidants. The phenol antioxidant having high heat resistance is preferably added in an amount of 0.05 to 0.5 parts by mass based on 100 parts by mass of the polyester resin to be obtained.

The polyester resin of the present invention has good water dispersibility, and therefore can be easily dispersed in warm water in the presence of a basic compound. The liquid temperature during the production of the aqueous dispersion is preferably from 30 ℃ to 85 ℃, more preferably from 40 ℃ to 80 ℃, and still more preferably from 45 ℃ to 75 ℃. Dispersion can also be performed with low water temperatures, but is time consuming. When the water temperature is high, the dispersion is fast, but when the water temperature is too high, the hydrolysis rate of the polyester segment tends to be high, and the number average molecular weight of the polyester resin of the present invention tends to be low.

Examples of the basic compound used in the method for producing the polyester resin aqueous dispersion of the present invention include ammonia, organic amine compounds, inorganic basic compounds, and the like.

Specific examples of the organic amine compound include alkylamines such as triethylamine, isopropylamine, ethylamine, diethylamine and sec-butylamine, alkoxyamines such as 3-ethoxypropylamine, propylamine and 3-methoxypropylamine, alkanolamines such as N, N-diethylethanolamine, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, monoethanolamine, diethanolamine and triethanolamine, and morpholines such as morpholine, N-methylmorpholine and N-ethylmorpholine. Among these organic amine compounds, alkanolamines having high hydrophilicity, particularly triethanolamine, can improve water dispersibility.

Specific examples of the inorganic basic compound include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide, carbonates of alkali metals such as sodium hydrogencarbonate and sodium carbonate, bicarbonates and ammonium carbonate. The polyvalent metal basic compound is preferably used in a small amount because it may form a salt which is hardly soluble with the plurality of carboxyl groups and water contained in the polyester resin of the present invention and may deteriorate dispersibility.

The basic compound needs to be added in an amount capable of neutralizing at least a part of the carboxyl groups of the polyester resin of the present invention, and specifically, is desirably added in an amount of 0.5 to 1.0 equivalent relative to the acid value of the polyester resin of the present invention. In addition, the polyester resin of the present invention may be prepared by forming an aqueous dispersion with less than 1.0 equivalent of a basic compound to the acid value of the polyester resin, and then adding the basic compound again so that the final amount of the basic compound added is 0.5 to 1.0 equivalent to the acid value. In this case, the pH of the aqueous dispersion is preferably adjusted to 6.5 to 7 from the viewpoint of suppressing hydrolysis of the polyester segment. When the addition ratio of the basic compound is too low, water dispersibility tends to decrease, and when it is too high, the pH of the aqueous dispersion may increase, which may cause hydrolysis of the polyester resin.

Although it is not necessary to use an emulsifier or an organic solvent for producing the aqueous dispersion of the polyester resin of the present invention, it is not necessarily excluded. Further stabilization of the aqueous dispersion may be achieved by using various nonionic emulsifiers and anionic emulsifiers. Further, by dissolving the polyester resin of the present invention in an appropriate organic solvent in advance and then phase-transferring it, a more stable aqueous dispersion may be obtained.

The content of the emulsifier in the aqueous polyester resin dispersion is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, further preferably 1 part by mass or less, and may be 0 part by mass, based on 100 parts by mass of the polyester resin. The content of the organic solvent in the aqueous polyester resin dispersion is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, further preferably 10 parts by mass or less, and may be 0 part by mass, based on 100 parts by mass of the polyester resin.

The aqueous polyester resin dispersion of the present invention can be used as an adhesive. In this case, when a curing agent that reacts with a carboxyl group is added, an adhesive having a higher adhesive strength can be obtained. As the curing agent, various curing agents such as melamine-based, benzoguanamine-based, and other amine resins, polyvalent isocyanate compounds, polyvalent oxazoline compounds, polyvalent epoxy compounds, phenol resins, and carbodiimide compounds can be used. Particularly preferably, the polyvalent epoxy compound or polyvalent oxazoline compound has high reactivity with a carboxyl group, is curable at low temperature, and can also give a high adhesive strength. Among them, polyvalent epoxy compounds are preferable. In addition, polyvalent metal salts may also be used as curing agents.

When these curing agents are used, the content thereof is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, and still more preferably 5 to 30 parts by mass, based on 100 parts by mass of the polyester resin of the present invention. When the amount of the curing agent is less than 5 parts by mass, the curing property tends to be insufficient, and when it exceeds 50 parts by mass, the coating film tends to be excessively hard.

As the curing agent for the aqueous adhesive of the present invention, preferable polyvalent epoxy compounds include novolak epoxy resins, bisphenol epoxy resins, triphenol methane epoxy resins, amino group-containing epoxy resins, and copolymerization epoxy resins. Examples of the novolak type epoxy resin include a novolak type epoxy resin obtained by reacting a phenol such as phenol, cresol, or alkylphenol with formaldehyde in the presence of an acidic catalyst, and a novolak type epoxy resin obtained by reacting epichlorohydrin and/or methylepichlorohydrin. Examples of the bisphenol-type epoxy resin include resins obtained by reacting a bisphenol such as bisphenol a, bisphenol F, bisphenol S, and the like with epichlorohydrin and/or methylepichlorohydrin, and resins obtained by reacting a condensate of a diglycidyl ether of bisphenol a and the bisphenol with epichlorohydrin and/or methylepichlorohydrin. Examples of the triphenol methane type epoxy resin include resins obtained by reacting triphenol methane, trichenol methane, and the like with epichlorohydrin and/or methyl epichlorohydrin. Examples of the amino group-containing epoxy resin include glycidyl amine-based resins such as tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidyl bisaminomethylcyclohexanone, and N, N' -tetraglycidyl m-xylylenediamine. Examples of the copolymerizable epoxy resin include a copolymer of glycidyl methacrylate and styrene, a copolymer of glycidyl methacrylate, styrene and methyl methacrylate, and a copolymer of glycidyl methacrylate and cyclohexylmaleimide.

The polyester resin aqueous dispersion of the present invention has a self-emulsifying effect, and therefore, an epoxy compound insoluble in water can be used as a curing agent, but a water-soluble epoxy resin is preferable because it is easy to use, and examples of the water-soluble epoxy resin include a resin in which a part of the hydroxyl groups of a water-soluble compound such as polyethylene glycol, glycerin and a derivative thereof, sorbitol, and the like are glycidyl groups, specifically, polyglycol glycidyl ether, glycerin polyglycidyl ether, sorbitol-based polyglycidyl ether, and the like.

As the curing agent for the aqueous adhesive of the present invention, commercially available oxazoline compounds can be used as the polyvalent oxazoline compound, and EPOCROS (registered trademark) WS-500, WS-700, EPOCROS K-2010E, EPOCROS K-2020E, and the like, which are made by Japanese catalyst, can be used.

As the curing agent for the aqueous adhesive of the present invention, commercially available carbodiimide compounds can be used as suitable carbodiimide compounds, and Nissin-Splendite V-02, V-04, and the like can be used.

As the curing agent for the aqueous adhesive of the present invention, calcium salt, zinc salt, aluminum salt and the like can be used as suitable polyvalent metal salt, and calcium chloride and zinc ammonium carbonate are particularly preferable.

As the curing agent for the aqueous adhesive of the present invention, a condensate of alkylated phenols and/or cresols and formaldehyde can be exemplified as a suitable phenol resin. Specifically, there may be mentioned condensates of formaldehyde with alkylated phenols such as methyl, ethyl, propyl, isopropyl and butyl alkyl, p-tert-amylphenol, 4 '-sec-butylphenol, p-tert-butylphenol, o-cresol, m-cresol, p-cyclohexylphenol, 4' -isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol and xylenol.

Examples of suitable ammonia resins as the curing agent for the aqueous adhesive of the present invention include formaldehyde adducts such as urea, melamine and benzoguanamine, and alkyl ether compounds obtained by alkoxylating these compounds with an alcohol having 1 to 6 carbon atoms. Specifically, there may be mentioned methoxylated methylolurea, methoxylated methylol-N, N-ethyleneurea, methoxylated methyloldicyandiamide, methoxylated methylolmelamine, methoxymethylol-benzoguanamine, butoxymethylolmelamine, butoxymethylolbenzoguanamine and the like, but methoxylated methylolmelamine, butoxymethylolmelamine and methylolated benzoguanamine may be used alone or in combination.

As the curing agent for the aqueous adhesive of the present invention, any of low molecular weight compounds and high molecular weight compounds can be used as a suitable polyvalent isocyanate compound. Examples of the low-molecular-weight compound include aliphatic isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, and xylylene isocyanate, aromatic isocyanate compounds such as toluene diisocyanate and diphenylmethane diisocyanate, and alicyclic isocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene isocyanate, and isophorone diisocyanate. Further, 3-mers of these isocyanate compounds and the like are also included. The polymer compound may be a terminal isocyanate group-containing compound obtained by reacting a compound having a plurality of active hydrogens with an excess amount of the low-molecular polyisocyanate compound. Examples of the compound having a plurality of active hydrogens include polyhydric alcohols such as ethylene glycol, propylene glycol, trimethylolpropane, glycerol, and sorbitol, polyamines such as ethylenediamine, compounds having a hydroxyl group and an amino group such as monoethanolamine, diethanolamine, and triethanolamine, and active hydrogen-containing polymers such as polyester polyols, polyether polyols, and polyamides.

The isocyanate blocking agent may be phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol and other phenols, acetone oxime, methyl ethyl ketoxime, cyclohexanone oxime and other oximes, methanol, ethanol, propanol, butanol and other alcohols, chlorohydrin, 1, 3-dichloro-2-propanol and other halogenated alcohols, t-butanol, t-amyl alcohol and other 3 rd grade alcohols, -caprolactam, -valerolactam, γ -butyrolactam, β -propiolactam and other lactams, and further aromatic amines, imides, acetylacetone, acetoacetate, ethyl malonate and other active methylene compounds, thiols, imines, ureas, diaryl compound sodium hydrogensulfite and the like.

An aqueous ink can be obtained by mixing a colorant in the polyester resin aqueous dispersion of the present invention, and the water resistance of the ink can be improved by further mixing a curing agent reactive with a carboxyl group. As the colorant, known pigments and dyes may be mixed. The polyester resin of the present invention has a high acid value and high dispersibility of various pigments, and thus can be used for producing a high-density aqueous ink. As the curing agent, those exemplified in the adhesive application can be used. The content of the colorant is preferably 1 to 20 parts by mass, more preferably 2 to 10 parts by mass, per 100 parts by mass of the polyester resin.

The water resistance of the coating film can be improved by mixing various pigments and additives with the polyester resin aqueous dispersion of the present invention and further mixing a curing agent reactive with carboxyl groups. The pigment may be a known organic/inorganic coloring pigment, an extender pigment such as calcium carbonate or talc, an anticorrosive pigment such as red lead or lead monoxide, an aluminum powder, or various functional pigments such as zinc sulfide (fluorescent pigment). Further, additives generally used in paints, such as plasticizers, dispersants, anti-settling agents, emulsifiers, tackifiers, antifoaming agents, mildewcides, preservatives, antiskinning agents, anti-sagging agents, matting agents, antistatic agents, conductive agents, and flame retardants, may be mixed as the additives. The polyester resin of the present invention has a high acid value and high dispersibility of various pigments, and thus can be used for producing a high-concentration water-based paint. As the curing agent, those exemplified in the adhesive application can be used. The content of the pigment and the additive is preferably 1 to 20 parts by mass, more preferably 2 to 10 parts by mass, based on 100 parts by mass of the polyester resin.

The aqueous dispersion, aqueous adhesive, aqueous coating material and aqueous ink of the present invention can be adjusted to viscosity and viscosity suitable for workability by mixing various thickening agents. Based on the system stability by the addition of the thickener, nonionic substances such as methylcellulose and polyalkylene glycol derivatives, and anionic substances such as polyacrylate and alginate are preferable.

The aqueous dispersion, aqueous adhesive, aqueous coating material and aqueous ink of the present invention can further improve coatability by using various surface tension adjusting agents. Examples of the surface tension adjusting agent include acrylic, vinyl, silicone, and fluorine-based surface tension adjusting agents, and among these, acrylic and vinyl surface tension adjusting agents are preferable because adhesiveness is not easily impaired, although there is no particular limitation. Since the adhesive strength tends to be impaired when the amount of the surface tension adjusting agent added is excessive, it is preferably 1 part by mass or less, more preferably 0.5 part by mass or less, per 100 parts by mass of the polyester resin.

The aqueous dispersion obtained by the present invention may be added with known additives such as a surface smoothing agent, an antifoaming agent, an antioxidant, a dispersant, and a lubricant during the production of the aqueous dispersion or after the production.

The aqueous dispersion, aqueous adhesive, aqueous coating material and aqueous ink of the present invention can further improve the optical rotation resistance and oxidation resistance by adding various ultraviolet absorbers, antioxidants or light stabilizers. Weather resistance can also be improved by adding an ultraviolet absorber, an antioxidant, a light stabilizer emulsion and an aqueous solution to the polyester resin aqueous dispersion. As the ultraviolet absorber, any of various organic systems such as benzotriazole, benzophenone, and triazine, and inorganic systems such as zinc oxide can be used. Further, as the antioxidant, various antioxidants can be used for general polymers such as hindered phenols, phenothiazine, nickel compounds, and the like. Although various light stabilizers for polymers can be used, hindered amine-based light stabilizers are highly effective. The content of the ultraviolet absorber, antioxidant or light stabilizer is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, based on 100 parts by mass of the polyester resin.

The layer (layer a) containing the polyester resin of the present invention may be laminated with a layer (layer B) selected from the group consisting of a film, a sheet, a woven fabric, a nonwoven fabric, and paper to form a laminate. The laminate can be easily obtained by, for example, applying the aqueous adhesive and/or aqueous ink of the present invention on a layer (layer B) selected from the group consisting of a film, a sheet, a woven fabric, a nonwoven fabric, and paper, and drying the applied layer. The aqueous adhesive and the aqueous ink of the present invention exhibit strong adhesion to films, sheets, woven fabrics, nonwoven fabrics and papers made of various raw materials, but exhibit particularly high adhesion to polylactic acid, polyester, polyurethane, polyamide, cellulose, starch, vinyl chloride, vinylidene chloride, chlorinated polyolefin, and films and sheets made of chemically modified substances thereof. Further, the aqueous adhesive and aqueous ink containing the polyester resin of the present invention also exhibit high adhesive strength to various metal deposited films, and thus are useful as a laminate of the 3-layer structure of the a layer/metal deposited layer/B layer. The metal and the B layer used for the metal vapor-deposited layer are not particularly limited, but particularly, the adhesion force of the aluminum vapor-deposited layer and the polyester resin aqueous adhesive and the aqueous ink of the present invention is large. It is considered that the polyester resin aqueous adhesive and aqueous ink of the present invention exhibit high adhesive force to various metal deposition films as an effect that the polyester resin of the present invention has a prescribed acid value.

The laminate can be used as a component of a packaging material. The packaging material is not particularly limited, and food and medical use are exemplified.