JP3501234B2 - Copolymerized polyester resin-based aqueous dispersion and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aqueous dispersion of a copolyester resin and a method for producing the same. More specifically, it is an aqueous dispersion of a copolyester resin having a fine particle size excellent in redispersibility and excellent in storage stability, and used as a vehicle for paints, inks, coating agents, adhesives, etc. The present invention relates to the provision of a copolyester resin-based aqueous dispersion useful as a processing agent for fibers, films, paper products and the like.

[0002]

2. Description of the Related Art High molecular weight copolyester resins have been used and recognized for their usefulness in the above-mentioned fields of application, particularly in fields requiring excellent flexibility and adhesion to various substrates. However, most of them are actually used in the form of being dissolved in a solvent.

Many patents are already known for the water-based method by graft modification of a low molecular weight copolyester, and these techniques are described in US Pat. No. 3,634,351, Japanese Patent Publication No. 57-57065, and US Pat. No. 4,517,322. However, the polyesters targeted by them belong to the alkyd resin, and their molecular weight is very low, and the coating film obtained from the aqueous dispersion has the drawbacks of low processability and poor water resistance.

As an example of making a high molecular weight unsaturated copolyester into an aqueous system, JP-B-61-57874 and JP-A-59-22337.
No. 4, JP-A-62-225510 and JP-A-3-294322 can be cited, but a co-polyester which is limited to a reaction or use at a low solid content concentration in which a crosslinking reaction occurs as a side reaction to cause gelation Since the terminal group is modified to a double bond, the process is complicated, the reaction is difficult to control, the productivity is low, and the like, which is industrially disadvantageous.

[0005]

Therefore, the present inventors have found that
1) Does not contain externally added emulsifier, and is in water or an aqueous medium with a sufficiently reduced organic solvent content 2) Has a fine particle size with excellent redispersibility and forms a stable aqueous dispersion even at high solids concentration In addition, and 3) to provide a graft-modified resin in which gelation due to a crosslinking reaction is suppressed, satisfying at a very high level that the raw material polyester resin has high processability and substrate adhesion. It is intended.

[0006]

That is, the present invention relates to polymerization.
Of dicarboxylic acid containing unsaturated unsaturated group to the total acid
˜7 mol% Copolymerized polyester resin obtained by copolymerization is graft-polymerized with a radical-polymerizable monomer containing a hydrophilic group-containing radical-polymerizable monomer. The graft polymer is water or water-soluble Is a copolyester resin-based water dispersion dispersed in a mixed solvent with an organic solvent, wherein the graft polymer is a copolyester resin-based water system in which fine particles having an average particle size of 500 nm or less are dispersed. It is a dispersion.

The copolyester resin-based aqueous dispersion of the present invention comprises 1) a graft polymer having a self-emulsifying property, so that a high content in a water-based medium, a fine particle size, and Disperse stably. 2) The film formed by drying at room temperature or by natural drying exhibits redispersibility that can be redispersed in water or an aqueous dispersion-containing liquid.

Therefore, when used as a coating agent, paint, ink or the like, it is possible to form a coating film having excellent adhesion to a substrate and having water resistance, solvent resistance, workability and smoothness. Various properties such as enabling can be exhibited.

(Copolymerized Polyester Resin) The copolymerized polyester resin of the present invention is essentially water-insoluble which does not disperse or dissolve in water by itself, and preferably has a molecular weight of 5,000 to 50,000. A preferable polymerization composition contains 60 to 99.5 mol% of an aromatic dicarboxylic acid, 0 to 40 mol% of an aliphatic dicarboxylic acid and / or an alicyclic dicarboxylic acid, and a polymerizable unsaturated double bond, based on all acid components. The dicarboxylic acid used is 0.5 to 10 mol%.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and the like. Acids can also be used. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and the like, and as the alicyclic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1, Examples thereof include 3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and acid anhydrides thereof.

The aromatic dicarboxylic acid as the dicarboxylic acid component is more preferably 70 to 98 mol%, and the aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid is more preferably 0 to 30 mol%. 60 aromatic dicarboxylic acids
When it is less than mol%, the workability of the coating film and the blister resistance and blister resistance of the coating film after the retort treatment tend to decrease. Further, when the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid exceeds 40 mol%, the hardness, stain resistance and retort resistance tend to decrease, and the aliphatic ester bond is more resistant to hydrolysis than the aromatic ester bond. Due to its low degradability,
Problems such as a decrease in the degree of polymerization of polyester may occur during storage of the aqueous dispersion or its coating composition.

Examples of the dicarboxylic acid containing a polymerizable unsaturated double bond include α, β-unsaturated dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid,
Examples of citraconic acid and alicyclic dicarboxylic acid containing an unsaturated double bond include 2,5-norbornene dicarboxylic acid anhydride and tetrahydrophthalic anhydride. The most preferred of these are fumaric acid, maleic acid and 2,5-norbornene dicarboxylic acid (endo-bicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic acid).

The dicarboxylic acid containing a polymerizable unsaturated double bond is 2 to 7 mol% based on the total acid component. When the dicarboxylic acid containing a polymerizable unsaturated double bond is 2 mol% or less, it is difficult to efficiently graft the radical polymerizable monomer onto the polyester resin, and the dispersed particle size in the aqueous medium is large. And the dispersion stability tends to decrease.

If the dicarboxylic acid containing a polymerizable unsaturated double bond exceeds 7 mol%, the viscosity will increase too much in the latter stage of the grafting reaction and the uniform progress of the reaction will be hindered.

On the other hand, the glycol component comprises an aliphatic glycol having 2 to 10 carbon atoms and / or an alicyclic glycol having 6 to 12 carbon atoms and / or an ether bond-containing glycol. However, as the aliphatic glycol having 2 to 10 carbon atoms, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5 -Petanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5
-Pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol and the like can be mentioned, and as the alicyclic glycol having 6 to 12 carbon atoms,
4-cyclohexane dimethanol etc. can be mentioned.

As the ether bond-containing glycol, diethylene glycol, triethylene glycol, dipropylene glycol, and ethylene oxide or propylene oxide are added to the two phenolic hydroxyl groups of the bisphenols. Examples thereof include glycols obtained by adding one to a few moles of each, such as 2,2-bis (4-hydroxyethoxyphenyl) propane. Polyethylene glycol, polypropylene glycol and polytetramethylene glycol can also be used if necessary.

It is possible to copolymerize 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol in the copolymerized polyester resin used in the present invention.
As the polycarboxylic acid having a functionality or higher, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenone tetracarboxylic acid, trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anhydrotrimeric) Melitate) is used. On the other hand, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like are used as the trifunctional or higher functional polyol. The trifunctional or higher polycarboxylic acid and / or polyol is copolymerized in an amount of 0 to 5 mol%, preferably 0 to 3 mol%, with respect to the total acid component or the total glycol component, but is 5 mol. If it exceeds%, it becomes difficult to impart sufficient workability.

(Radical Polymerizable Monomer) The radical polymerizable monomer which is graft-polymerized with the copolyester resin has a hydrophilic group or a group which can be changed to a hydrophilic group later. They are radically polymerizable monomers and other radically polymerizable monomers. Examples of the hydrophilic group include a carboxyl group, a hydroxyl group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, an amide group, a quaternary ammonium salt, and the like, and as a group that can be changed to a hydrophilic group. Can include an acid anhydride group, a glycidyl group, a chloro group and the like. Among these hydrophilic groups, a carboxyl group is preferred because it is easy to control the water dispersibility by changing the acid value, and a radical polymerizable monomer having a carboxyl group or a group capable of generating a carboxyl group is preferred.

Examples of the carboxyl group-containing radically polymerizable monomer capable of changing the acid value by graft polymerization on the copolyester resin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, etc. Other examples include maleic anhydride, itaconic anhydride, and methacrylic anhydride that easily generate a carboxylic acid in contact with an aqueous alkaline medium, and one or more of them may be selected and used. You can The most desirable carboxyl group-containing radically polymerizable monomers are acrylic acid, methacrylic acid and maleic anhydride.

In the present invention, in addition to these carboxyl group-containing radically polymerizable monomers, it is usual to use a radically polymerizable monomer not containing a carboxyl group in combination. A wide range of radically polymerizable monomers can be mentioned as the radically polymerizable monomer containing no carboxyl group. That is, as acrylic acid and methacrylic acid esters, methyl acrylate, ethyl acrylate, isopropyl acrylate, -n-butyl acrylate, 2-ethylhexyl acrylate, acrylate-2
-Hydroxyethyl, hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, -n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate. ,
Further well known monomers such as hydroxylpropyl methacrylate are acrylonitrile, methacrylonitrile, acrylamide, N-methyl acrylamide, diacetone acrylamide, vinyl acetate, vinyl ethers, N-vinylpyrrolidone, styrene and α. -Methylstyrene, t-butylstyrene, vinyltoluene and the like can be exemplified, and one or more of these can be selected and used.

Further, the number of components of the radical-polymerizable monomer mixture is preferably 2 or more. The number of components is 1
In the case of only the carboxyl group-containing monomer, the grafting on the polyester chain does not occur smoothly, and it is difficult to obtain a good water dispersion. The second component, acrylic acid,
Grafting with high efficiency can be performed only by copolymerization with methacrylic acid esters.

The application of radical copolymerization theory provides a powerful guide for the selection of the above-mentioned monomers. For example, diethyl fumarate (monomer 1), Q, e value of each monomer (monomer 2) (for example, Polymer Handbook, 3rd. Ed. J
ohn Wiley and Sons, 1989) using the formula r ₂ = Q ₂ / Q ₁ exp [-
The copolymerization reactivity ratio of each monomer to diethyl fumarate (hereinafter referred to as r ₂ value) can be obtained from e ₂ (e ₂ -e ₁ )].

The inventors of the present invention have prepared a copolyester in which any one of fumaric acid, maleic acid and 2,5-norbornenedicarboxylic acid is copolymerized depending on the copolymerizable reactivity ratio of diethyl fumarate and various monomers. It was found that the reactivity of the radically polymerizable monomer, specifically the grafting efficiency, and the gelation tendency of the crosslinking reaction can be predicted. That is, among the monomers listed above, acrylic acid, methacrylic acid and their esters, nitriles, amides, etc. r ₂
When a monomer mixture consisting of monomers having a value of 1 to 12 is subjected to grafting by the dropwise addition method, gelation can be avoided, while the above-mentioned monomer mixture has an r ₂ value of 10 ^-1. ~ 10 ^-4
If a monomer having an r ₂ value of 1 or less, such as styrene, vinyl acetate, vinyl ether, or N-vinylpyrrolidone, which is an order value, is used in combination, crosslinking between polyester molecules during the grafting reaction is very likely to occur. I found a lot.

The present inventors have further studied various methods of utilizing monomers having an r ₂ value of 1 or less and made the following new discoveries. That is, a monomer having low homopolymerizability such as maleic anhydride, fumaric acid diester, and maleic acid diester and having a high electron accepting property is allowed to be present together with a polymerizable double bond-containing copolyester, and electron If highly reactive styrenes, vinyl esters, vinyl ethers, etc. are subjected to the reaction, the grafting reaction will be carried out very smoothly, and the subsequent basic compound and water will give a better aqueous dispersion without gelation. I found a thing.

In this case, the graft chain is an alternating copolymer chain of an electron-accepting monomer and an electron-donating monomer, and the graft chain is composed of the above-mentioned monomer having an r ₂ value in the range of 1 to 12. Is a random copolymer chain. There is no description of such a graft polymer in the prior art already mentioned.

The ratio of the hydrophilic group-containing monomer to the carboxyl group-free monomer is preferably 95/5 by weight.
~ 5/95, more preferably 90/10 ~ 10/90
However, it is necessary to determine in consideration of the acid value given to the graft reaction product.

The total acid value of the copolymerized polyester resin-based graft polymer of the present invention before being neutralized is 600-4000e.
q./10 ⁶ g is desirable, more preferably 700-300
A 0eq./10 ⁶ g, the most preferably 800-2500eq./10 ⁶ g. When the acid value is 600 eq./10 ⁶ g or less, it is difficult to obtain a dispersion having a small particle size when dispersed in water, and the dispersion stability tends to decrease. When the acid value is 4000 eq./10 ⁶ g or more, the water resistance of the coating film formed from the aqueous dispersion tends to be low.

(Grafting reaction) The copolymerized polyester resin-based graft polymer is efficiently obtained by graft-polymerizing a radically polymerizable monomer to the polymerizable unsaturated double bond in the copolymerized polyester resin. To be

The present invention is generally carried out by reacting a radical initiator and a radically polymerizable monomer mixture in a state where the copolyester resin is dissolved in an organic solvent. After the completion of the grafting reaction, the reaction product is a grafted polymer between the desired copolymerized polyester-radical polymerizable monomer mixture, a copolymerized polyester not grafted, and a radical not grafted to the copolymerized polyester. Although it may contain a polymer in some cases, the graft polymer in the present invention means a polymer containing these non-grafted products to the extent that water dispersibility is not deteriorated. When the ratio of the graft polymer in the graft reaction product is low and the ratio of the non-grafted polyester and the non-grafted radical polymer is high, it is not possible to obtain an aqueous dispersion having a fine particle size and good stability.

(Mode of Grafting Reaction) When carrying out the grafting reaction of the radically polymerizable monomer with respect to the copolymerized polyester resin, the radically polymerizable monomer is dissolved with respect to the copolymerized polyester resin dissolved in a solvent under heating. The monomer mixture and the radical initiator may be added at one time, or the mixture may be separately added dropwise over a certain period of time, and then the reaction may be continued by continuing heating under stirring for a certain period of time. . In addition, after adding a certain type of monomer at a time, another type of monomer and the initiator are separately added dropwise over a certain period of time, and then the reaction is continued by heating for a certain period of time with stirring. It is also made to proceed if necessary.

Prior to the reaction, the copolyester resin and the solvent are charged into the reactor and the temperature is raised with stirring to dissolve the resin. The weight ratio of copolyester resin to solvent is 7
It is preferably in the range of 0/30 to 30/70. In this case, the weight ratio is adjusted in consideration of the reactivity of the copolymerized polyester resin and the radical-polymerizable monomer and the solubility in a solvent so that the reaction can be carried out uniformly during the polymerization process.

The grafting reaction temperature is 50 ° C to 120 ° C.
It is desirable to carry out in the range of ° C.

The desirable weight ratio of the copolymerized polyester resin and the radical-polymerizable monomer which meet the purpose of the present invention is polyester / radical-polymerizable monomer = 40/60 to 95.
/ 5, more preferably 55/45 to 93 /
7, most preferably 60/40 to 90/10.

The weight ratio of the copolyester resin is 40
When the content is less than 10% by weight, the above-described excellent performance of the base polyester, that is, high processability, excellent water resistance, and excellent adhesion to various base materials cannot be sufficiently exhibited, and conversely the acrylic resin Undesired performance of low workability,
It will add gloss and water resistance. When the weight ratio of the polyester is 95% by weight or more, the amount of carboxyl groups in the radical-polymerizable monomer graft chain responsible for hydrophilization becomes insufficient, and a good water dispersion cannot be obtained.

(Radical Initiator etc.) Well-known organic peroxides and organic azo compounds can be used as the radical polymerization initiator used in the present invention. That is, benzoylperoxide, t-butylperoxypivalate as an organic peroxide and 2,2'- as an organic azo compound.
Examples thereof include azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile).

Regarding the selection of the radical initiator compound,
Radical generation rate of the compound at a reaction temperature,
That is, it is necessary to consider the half-life. Generally, it is desirable to select a radical initiator having a half-life value at that temperature in the range of 1 minute to 2 hours. The amount of the radical initiator used for carrying out the grafting reaction must be at least 0.2% by weight or more based on the radical polymerizable monomer,
Desirably, it is necessary to use 0.5% by weight or more. Addition of a chain transfer agent such as octyl mercaptan or mercaptoethanol is also used as necessary for controlling the graft chain length. In that case, it is desirable to add the radically polymerizable monomer in an amount of 0 to 5% by weight.

(Reaction Solvent) The grafting reaction solvent for carrying out the present invention is preferably composed of a water-soluble organic solvent having a boiling point of 50 to 250 ° C. Here, the water-soluble organic solvent refers to one having a solubility in water at 20 ° C. of at least 10 g / L or more, preferably 20 g / L or more. Those having a boiling point of higher than 250 ° C. are not suitable because the evaporation rate is too slow and they cannot be removed sufficiently by high temperature baking of the coating film. Further, when the boiling point is 50 ° C. or lower, when the grafting reaction is carried out using it as a solvent, an initiator that cleaves into radicals at a temperature of 50 ° C. or lower must be used, which increases the handling risk and is not preferable.

Esters are used as the first group of water-soluble organic solvents which dissolve the copolyester resin well and relatively well dissolve the polymer of the polymerizable monomer containing the carboxyl group-containing polymerizable monomer. , For example, ethyl acetate, ketones,
For example, methyl ethyl ketone, methyl isobutyl ketone,
Cyclohexanone, cyclic ethers such as tetrahydrofuran, dioxane, 1,3-dioxolane, glycol ethers such as ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol propyl ether, ethylene glycol ethyl ether, Ethylene glycol butyl ether, carbitols such as methyl carbitol, ethyl carbitol, butyl carbitol, glycols or lower esters of glycol ether such as ethylene glycol diacetate, ethylene glycol ethyl Examples include ether acetates, ketone alcohols such as diacetone alcohol, and N-substituted amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. You can do it.

On the other hand, as the second group of water-soluble organic solvents which dissolves the copolymerized polyester resin hardly, but relatively dissolves the polymer of the polymerizable monomer containing the carboxyl group-containing polymerizable monomer, Water, alcohols, carboxylic acids, amines and the like can be mentioned, but alcohols having 1 to 8 carbon atoms and polyhydric alcohols are particularly preferable for carrying out the present invention.

When the grafting reaction is carried out with a single solvent, only one kind of water-soluble organic solvent of the first group can be selected and used. When a mixed solvent is used, a plurality of types are selected only from the first group of water-soluble organic solvents, and at least one type is selected from the first group of water-soluble organic solvents and at least one type is added from the second group of water-soluble organic solvents. There is.

Either when the graft polymerization reaction solvent is a single solvent from the first group of water-soluble organic solvents or when it is a mixed solvent consisting of one kind of each of the first and second groups of water-soluble organic solvents. Also in the above, the graft polymerization reaction can be carried out. However, there are differences in the progress behavior of the grafting reaction, the appearance of the grafting reaction product and the aqueous dispersion derived from it, and the properties, etc., and it is a mixture of water-soluble organic solvents of the first and second groups. It is preferable to use a solvent.

That is, it belongs to the first group of water-soluble organic solvents,
The grafting reaction is transparent from beginning to end when tetrahydrofuran is used as the sole solvent, which has the strongest dissolving power for polyester resins, monomer mixtures containing carboxyl group-containing polymerizable monomers and polymers derived therefrom. Progress with a nice appearance. In some cases, the viscosity of the system gradually increases, and in the latter stage of the grafting reaction, the viscosity increases remarkably and the reaction cannot be continued. In such a case, the reaction product is transparent and rubber-like with the solvent taken up, indicating the formation of a gel that does not dissolve in a strong solvent. To avoid this, it is necessary to drastically reduce the resin concentration, which is not a rational method in manufacturing. On the other hand, methyl ethyl ketone was selected from the water-soluble organic solvent of the first group, and isopropyl alcohol was selected from the water-soluble organic solvent of the second group.
When the solubility of the copolyester is adjusted using a mixed solvent system obtained by mixing at a weight ratio of 5, the polyester resin is exactly the same as in the case of tetrahydrofuran, the same radical polymerizable monomer composition ratio, Even if the reaction is carried out with the same polyester / radical polymerizable monomer ratio and the same resin solid content, neither thickening nor gelation of the system is observed with the progress of the grafting reaction. Further, the subsequent aqueous system gives a good aqueous dispersion. From this, it can be understood that the use of the mixed solvent system is a rational process which can increase the resin solid content concentration during production and can reduce the amount of organic solvent used during production.

In the solvent of the first group, the copolyester resin molecular chain is in a state where the chain having a large spread extends, while in the mixed solvent of the first group / the second group, a state where the molecular chain is entangled in a thread form having a small spread. It was confirmed by the viscosity measurement of the copolyester resin in these solutions. It is effective to prevent gelation by adjusting the dissolution state of the copolyester resin to prevent intermolecular crosslinking. The compatibility of highly efficient grafting and suppression of gelation is achieved in the latter mixed solvent system.

The weight ratio of the mixed solvent of the first group / the second group is more preferably 95/5 to 10/90, further preferably 90.
/ 10 to 20/80, most preferably 85/15 to 30
The range is / 70. The optimum mixing ratio is determined according to the solubility of the resin used and the polyester resin.

(Water Dispersion) The grafting reaction product according to the present invention is preferably neutralized with a basic compound,
By neutralizing, it is possible to easily disperse in water into fine particles having an average particle size of 500 nm or less. As the basic compound, a compound that volatilizes during coating film formation or bake-curing with a curing agent is preferable, and ammonia, organic amines and the like are preferable. Examples of desirable compounds include triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, Diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethylamine Examples thereof include ethanolamine.
The basic compound has a pH value of 5.0- due to at least partial neutralization or complete neutralization depending on the carboxyl group content contained in the graft reaction product.
It is desirable to use it in the range of 9.0.

In carrying out the water dispersion, the solvent contained in the grafting reaction product is previously removed by an extruder under reduced pressure to form a melted or solid (pellet, powder, etc.) grafting reaction. It is also possible to prepare an aqueous dispersion by throwing the product into water containing a basic compound and stirring under heating, but most preferably, the water containing the basic compound is immediately added at the time when the grafting reaction is completed. A method (one-pot method) of charging the mixture and continuing heating and stirring to obtain an aqueous dispersion is preferable. Furthermore, the boiling point of the solvent
When the temperature is 100 ° C. or lower, a part or all of the solvent used for the grafting reaction can be easily removed by distillation.
The dispersion medium of the water dispersion is water or a mixture with a water-soluble organic medium, and examples of this organic solvent include the above-mentioned graft polymerization solvents, preferably methyl ethyl ketone and isopropanol. The aqueous dispersion produced according to the present invention has a solid content concentration of 20 to 60% by weight, and can be used by adding water and diluting it if necessary.

(Characteristics of Aqueous Dispersion) The aqueous dispersion produced by the present invention has a weight average molecular weight of 5000-500 as a raw material.
It is preferable to use a copolyester of 00.
When the weight average molecular weight is 5,000 or less, the physical properties of the resin such as the post-processability of the dry coating film tend to deteriorate. When the weight average molecular weight is further lower, the copolyester itself tends to be water-soluble and does not form a core-shell structure described later.
Further, a copolyester having a weight average molecular weight of 50,000 or more tends to be difficult to disperse in water.

In the aqueous dispersion produced according to the present invention,
The weight average molecular weight of the polymer of radically polymerizable monomer is 500-
It is preferably 50,000. It is generally difficult to control the weight average molecular weight of the polymer of the radical-polymerizable monomer to 500 or less, the grafting efficiency is lowered, and there is a tendency that the hydrophilic group is not sufficiently imparted to the copolyester. is there. Further, the graft polymerization product of the radical-polymerizable monomer forms a hydrated layer of dispersed particles, but in order to obtain a stable dispersion by providing a hydrated layer of a sufficient thickness, the radical-polymerizable monomer of the radical-polymerizable monomer is used. The weight average molecular weight of the graft polymer is preferably 500 or more. The upper limit of the weight average molecular weight of the graft polymer of the radical-polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization. The control of the molecular weight within this range can be carried out by appropriately combining an initiator amount, a monomer dropping time, a polymerization time, a reaction solvent, a monomer composition, or a chain transfer agent or a polymerization inhibitor if necessary.

The aqueous dispersion according to the present invention has an average particle diameter of 500 nm or less as measured by a laser light scattering method and has a semitransparent to milky white appearance. The aqueous dispersion obtained in the present invention can be obtained as an aqueous dispersion having various particle diameters by adjusting the polymerization method, but the particle diameter is preferably 10 nm-500 nm, and 400 nm or less is preferable in view of dispersion stability, More preferably, it is 300 nm or less. When it exceeds 500 nm, the surface gloss decreases during film formation.

When 13 C NMR of the aqueous dispersion of the present invention was measured, the full width at half maximum of the signal of the carbonyl group of the ester portion of the copolyester resin was as large as 300 Hz or more, and the carboxyl group neutralized by the basic compound was contained. The full width at half maximum of the signal of the carboxyl group of the polymer of the radical-polymerizable monomer containing the radical-polymerizable monomer is observed to be as small as 150 Hz or less. Generally, in NMR, the full width at half maximum of the signal observed from the resin dissolved in the measurement solvent is small,
The full width at half maximum of the signal observed from the resin that is insoluble in the measurement solvent is large.

From the above, in the aqueous dispersion of the present invention, the copolyester resin, which is not originally dispersed or dissolved in water, exists as the core portion in the aggregated state, and the surrounding area is the carboxyl compound neutralized by the basic compound soluble in water. It has a structure in which a polymer of a radical-polymerizable monomer containing a group-containing radical-polymerizable monomer is wrapped as a shell part, and a core-shell structure is expressed in a fine particle state. The core-shell structure refers to a two-layer particle structure in which a core portion made of a resin insoluble in the dispersion medium and in an agglomerated state is wrapped with a shell portion made of a resin in the dissolved state soluble in the dispersion medium. This structure is a structure in which resins having different solubilities in the dispersion medium are chemically bonded to each other but characteristically appears in the dispersion, and cannot be expressed simply by mixing resins having different solubilities in the dispersion medium. It is a structure. Further, a mixture of resins simply different in solubility in a dispersion medium cannot exist as an aqueous dispersion having a particle size of 500 nm or less.

In the present invention, various characteristics of the aqueous dispersion can be recognized by providing the dispersion particles with such a structure. One is the stability of the aqueous dispersion, which gives a stable aqueous dispersion when the high molecular weight copolyester is dispersed without using an emulsifier or an organic cosolvent which is often used in other aqueous dispersions. This is because the resin in the shell portion forms a sufficient hydration layer and protects the dispersed particles. In addition, this aqueous dispersion has excellent redispersibility because it has a sufficiently thick shell portion. Here, the redispersibility means a property that a film formed from an aqueous dispersion can be dispersed again in water or an undiluted solution of an aqueous dispersion after losing water and an organic solvent at room temperature. This is a very important property for water-based resins. When the water dispersion is used for ink, paint, coating material, etc., the one that lacks redispersibility does not re-disperse in the coating solution because the dried part that is partly formed during the coating process does not cause defects in the coating film. Doing so will cause clogging of the rollers and spray gun. When the water dispersion of the present invention is applied to a substrate and heated and dried, the dispersion particles lose the above structure to form a uniform coating film, which has excellent processability of the polyester in the core portion.
Develops adhesion and water resistance.

(Use of Aqueous Dispersion) The aqueous dispersion according to the present invention is used as a vehicle for paints, inks, coating materials, adhesives, etc., or as a processing agent for fibers, films and paper products. The aqueous dispersion of the present invention can be used as it is, but by incorporating a crosslinking agent (curing resin) and performing bake curing, a high degree of water resistance can be exhibited. Examples of the cross-linking agent include phenol formaldehyde resin, amino resin, polyfunctional epoxy compound, polyfunctional isocyanate compound and various blocked isocyanate compounds thereof, and polyfunctional aziridine compound.

Examples of the phenol resin include formaldehyde condensation products of alkylated phenols and cresols. Specifically, alkylated (methyl, ethyl, propyl, isopropyl, butyl) phenol, p-tert-amylphenol, 4,4'-sec-butylidenephenol, p-tert-butylphenol, o-, m-, p -Formaldehyde condensates such as cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl o-cresol, p-phenylphenol, xylenol Can be mentioned.

Examples of the amino resin include formaldehyde adducts such as urea, melamine and benzoguanamine,
Further, an alkyl ether compound containing an alcohol having 1 to 6 carbon atoms can be mentioned. Specifically, methoxylated methylol urea, methoxylated methylol
N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, but preferably methoxylated methylol melamine, butoxylated methylol melamine, and methoxy Methylol benzoguanamine, which can be used alone or in combination.

Bisphenol A as an epoxy compound
Diglycidyl ether and its oligomer, hydrogenated bisphenol A diglycidyl ether and its oligomer, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, tetrahydrophthalic acid Acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol di Glycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid tri Lycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, triglycidyl ether of glycerol alkylene oxide adduct And so on.

Further, as the isocyanate compound, there are aromatic and aliphatic diisocyanates and polyisocyanates having a valence of 3 or more, and either low molecular weight compounds or high molecular weight compounds may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimer of these isocyanate compounds, and excess of these isocyanate compounds. The amount of the low molecular weight active hydrogen compound such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine or various polyester polyols, polyether polyols, polyamides Conflicts with high molecular weight active hydrogen compounds It includes terminal isocyanate group-containing compounds obtained by.

The isocyanate compound may be a blocked isocyanate. Examples of the isocyanate blocking agent include phenol, thiophenol,
Methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol and other phenols, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime and other oximes, methanol, ethanol, propanol, butanol and other alcohols, ethylene chlorohydrin, 1, Halogen-substituted alcohols such as 3-dichloro-2-propanol,
Tertiary alcohols such as t-butanol and t-pentanol, lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-propyllactam, and aromatic amines and imides. , Active methylene compounds such as acetylacetone, acetoacetic acid ester, malonic acid ethyl ester, mercaptans,
Examples include imines, ureas, diaryl compounds, sodium bisulfite, and the like. The blocked isocyanate is obtained by subjecting the above isocyanate compound, an isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

The method of blending the cross-linking agent is as follows: (1) When the cross-linking agent is aqueous, it is directly dissolved or dispersed in an aqueous dispersion, and (2) When the cross-linking agent is oily, it is dispersed in water after the completion of the grafting reaction. A method is used in which a crosslinking agent is added before or after the addition to make the core portion coexist with the polyester, and can be arbitrarily selected depending on the type and properties of the crosslinking agent. A curing agent or an accelerator may be used in combination with these crosslinking agents.

The curing reaction generally depends on the aqueous dispersion 1 of the present invention.
It is carried out by mixing 5 to 40 parts (solid content) of the curing resin with 00 parts (solid content) and heating at a temperature range of 60 to 250 ° C. for about 1 to 60 minutes depending on the type of the curing agent. If necessary, a reaction catalyst and a promoter are also used in combination. The aqueous dispersion of the present invention may be blended with pigments, dyes, various additives and the like. The aqueous dispersion of the present invention can be used in combination with other aqueous resins and aqueous dispersions, and the processability thereof can be improved.

Furthermore, since the paints, inks, coating agents, adhesives and various processing agents based on the aqueous dispersion according to the present invention are excellent in redispersibility, they are dip coated, brush coated, roll coated. It has applicability to all printing methods, spray methods and various printing methods. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0062]

EXAMPLES The present invention will be described below with reference to examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight". Each measurement item followed the following method. (1) Dissolve 0.03 g of weight average molecular weight resin in 10 cc of tetrahydrofuran and
C-LALLS device Low angle light scattering photometer LS-8000 (manufactured by Tosoh Corporation, tetrahydrofuran solvent, reference: polystyrene) was used for measurement.

(2) Polyester Grafting Efficiency The product obtained by graft polymerization was subjected to 220 MHz ¹ H NMR.
(Varian, measurement solvent CDCl3 / DMSO-d6) was used to measure the grafting efficiency based on the intensity change of the double bond-derived signal of the double bond-containing component copolymerized with the polyester. Polyester grafting efficiency = (1- (relative intensity of signal derived from double bond of double bond-containing component of graft polymerization product / relative intensity of signal derived from double bond of double bond-containing component of raw material polyester) × 10
0 (%) The relative intensity was calculated by comparison with the signal intensity of the internal signal as the reference signal.

(3) Weight average molecular weight measurement of graft chain The product obtained by the graft polymerization was subjected to hydrolysis of the copolyester under reflux in a KOH / water-methanol solution. The decomposition product was extracted with THF under acidic conditions, and the radical-polymerizable polymer was purified by reprecipitation with hexane. This polymer is a GPC device (manufactured by Shimadzu Corporation,
The weight average molecular weight of the graft chain was calculated by measuring with a tetrahydrofuran solvent (converted to polystyrene).

(4) Aqueous dispersion particle size The aqueous dispersion was prepared using only ion-exchanged water to obtain a solid content concentration of 0.1.
Laser light scattering particle size distribution meter Coulter m
It was measured at 20 ° C. with odel N4 (manufactured by Coulter).

(5) Water Dispersion B Type Viscosity The viscosity of the water dispersion is a rotational viscometer (manufactured by Tokyo Keiki Co., EM
Type) and was measured at 25 ° C.

(6) Aqueous dispersion The redispersible aqueous dispersion was coated on a glass plate so that the film thickness after drying was 15 μm, and dried at room temperature for 1 hour. The coated plate obtained was dipped in distilled water to compare it with that before dipping.
The comparison was made by the following five-stage evaluation. Rank 1: No change in appearance of coating film before and after immersion 2: Whitening of coating film surface 3: Peeling of coating film, but no redispersion in distilled water 4: Peeling of coating film, slight peeling in distilled water Redispersion with insoluble matter 5: The coating film peels off and is completely redispersed in distilled water

(7) Measurement of full width at half maximum of ¹³ C NMR The aqueous dispersion was diluted with heavy water to a solution concentration of 20% by weight and DSS was added to prepare a sample. After setting the measurement conditions such that the full width at half maximum of the DSS signal is 5 Hz or less, 125 MHz 13 C pulse Fourier transform NMR (manufactured by Varian) at 25 ° C. was measured with the carbon of the carbonyl group of the copolyester and the graft polymerization. The full width at half maximum of the signal of the carbon of the carbonyl group of the polymer part of the radically polymerizable monomer was measured.

(8) Hardness of Hardened Coating Film (Pencil Hardness) The coated surface of the steel sheet is a high-grade pencil specified in JIS S-6006,
It was measured according to JIS K-5400. (9) Cured coating film gloss gloss meter (VG107 manufactured by Nippon Denshoku Kagaku Co., Ltd.)
The 60 degree reflectance was measured.

(10) Hardened coating film Flexibility The coated steel sheet was bent 180 degrees, and cracks generated in the bent portion were observed and judged with a 10 times magnifying glass. 4T refers to the case where cracks do not occur in the bent part even when four bent parts having the same plate thickness are sandwiched.

(11) Adhesion of cured coating film: According to ASTM D-3359. (12) Cured coating film The film was rubbed with a gauze impregnated with solvent resistant xylene, and the number of times until the undercoat appeared was recorded.

(13) 25 solid parts of melamine resin (Sumimar M30W, manufactured by Sumitomo Chemical Co., Ltd.) per 100 solid parts of the cured coating film water-resistant aqueous dispersion,
A mixture of 0.25 solid part of paratoluenesulfonic acid (catalyst), 100 parts of titanium oxide and 250 parts of glass beads was shaken and dispersed for 5 hours with a paint shaker. Then, it was applied on a zinc iron plate so that the film thickness after drying was 15 μm, and baked at 230 ° C. for 1 minute. The coated plate thus obtained was boiled in boiling water for 2 hours and evaluated by gloss retention (%). The gloss retention rate was calculated by the following formula. Gloss retention rate (%) = (Gloss after treatment / Initial gloss) x 1
00 (14) Smoothness: visually determined. (15) A sample having an acid value of 1 g (solid content) was added with 30 cc of chloroform or
Dissolved in DMF and KO using phenolphthalein as an indicator
It was titrated with H 2 to determine the equivalent weight of the carboxyl group per 10 ⁶ g of the sample.

Production Example of Copolymerized Polyester Resin In a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser, 466 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, 401 parts of neopentyl glycol, 443 parts of ethylene glycol. , And 0.52 parts of tetra-n-butyl titanate,
The transesterification reaction was performed from 160 ° C to 220 ° C over 4 hours. Then add 23 parts of fumaric acid to 200 ℃ to 220 ℃
The temperature was raised to 1 hour, and the esterification reaction was carried out.
Then raise the temperature to 255 ° C and gradually reduce the pressure in the reaction system.
After reacting for 1 hour and 30 minutes under a reduced pressure of 0.2 mmHg, 19 parts of trimellitic anhydride was added and stirred under nitrogen at 220 ° C. for 1 hour to obtain polyester (A-1). Obtained polyester (A-
1) was light yellow and transparent and had a weight average molecular weight of 12,000. NM
The composition measured by R 2 etc. was as follows.

Dicarboxylic acid component terephthalic acid 47 mol% Isophthalic acid 47 mol% Fumaric acid 4 mol% Trimellitic acid 2 mol% Diol component neopentyl glycol 50 mol% Ethylene glycol 50 mol% Various compounds shown in Table 1 by the same method. Copolymerized polyesters (A-2 to A-10) were produced. Table 1 shows the reduced viscosity of each polyester and the composition analysis results measured by NMR and the like. In the table, each component shows mol%.

[0075]

[Table 1]

Example 1 A reactor equipped with a stirrer, a thermometer, a reflux device and a metering device was charged with 75 parts of copolymerized polyester resin (A-1), 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol and heated at 65 ° C. , And the resin was dissolved by stirring. After the resin was completely dissolved, a mixture of 17.5 parts of methacrylic acid and 7.5 parts of ethyl acrylate and a solution of 1.2 parts of azobisdimethylvaleronitrile dissolved in 25 parts of methyl ethyl ketone were added dropwise to the polyester solution at 0.2 ml / min. The stirring was continued for another 2 hours. After sampling for analysis (5 g) from the reaction solution, 300 parts of water and 25 parts of triethylamine were added to the reaction solution and stirred for 1 hour. After that, the temperature of the dispersion is 100 ℃
And methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off by distillation. The resulting aqueous dispersion (B-1) is white and has an average particle size of 300 nm and 25 ° C.
The B-type viscosity at 50 cps was 50 cps.

To 5 g of this aqueous dispersion, 1.25 g of heavy water was added to adjust the solid content concentration to 20% by weight, and then DSS was added to obtain 125 MHz.
¹³ C NMR was measured. The FWHM of the carbon signal of the carbonyl group of the copolyester (160-175ppm) is ∞ (no signal is detected), and the FWHM of the carbon signal of the carbonyl group of methacrylic acid (181ppm-186ppm) is 110H.
It was z. This aqueous dispersion was left at 40 ° C for 60 days,
No change in appearance was observed, while there was no change in viscosity, indicating excellent storage stability. The obtained water dispersion was applied onto a glass plate so that the solid film thickness was 15 μm.
When this coating film was air-dried at room temperature for 1 hour and then immersed in distilled water, the coating film immediately dispersed in water and showed excellent redispersibility of ranks 4 to 5.

At the end of the grafting reaction, the sampled solution was dried under vacuum at 100 ° C. for 8 hours to measure the acid value of the solid content, the polyester grafting efficiency (NMR measurement), and the grafting by hydrolysis. The molecular weight of the side chain was measured. Acid value of solid content is 2300 eq./10 ⁶ g
Met. ^{In 1} H NMR measurement, a signal derived from fumaric acid (δ = 6.8-6.9 ppm, doublet) was not detected at all, and thus the polyester grafting efficiency was 100%.
When the copolymerized polyester portion of the solid content was hydrolyzed and the molecular weight of the radical-polymerizable polymer was measured by GPC, the weight average molecular weight was 10,000.

Examples 2 to 7 Various aqueous dispersions (B-2 to B-7) were produced in the same manner as in Example 1. The performance of each of the obtained aqueous dispersions is shown in Table 2.

Comparative Examples 1 to 3 Various aqueous dispersions (B-8 to B-10) were produced in the same manner as in Example 1. The performance of each of the obtained aqueous dispersions is shown in Table 2.

Examples 8 to 11 Various water dispersions (B-11 to B-14) were produced in the same manner as in Example 1 with the compounding ratios shown in Table 3. The performance of each of the obtained aqueous dispersions is shown in Table 4.

Comparative Examples 4 to 7 Various water dispersions (B-15 to B-18) were produced in the same manner as in Example 1 with the compounding ratios shown in Table 3. The performance of each of the obtained aqueous dispersions is shown in Table 4.

Example 12 75 parts of copolymerized polyester resin (A-1), 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol were placed in a reactor equipped with a stirrer, a thermometer, a reflux device and a metering dropping device, and heated at 65 ° C. , And the resin was dissolved by stirring. After the resin was completely dissolved, 12.0 parts of maleic anhydride was added to the polyester solution, and 13.0 parts of styrene and 1.5 parts of azobisdimethylvaleronitrile were added.
A solution of 12 parts of methyl ethyl ketone dissolved in 0.1 ml /
It was dripped into the polyester solution at min and stirring was continued for another 2 hours. After sampling for analysis (5 g) from the reaction solution, 5 parts of methanol was added to convert the anhydride to an acid and an ester, 300 parts of water and 15 parts of triethylamine were added to the reaction solution, and the mixture was stirred for 1 hour. Then, the temperature of the dispersion was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off. The resulting water dispersion (B-19) is white and has an average particle size.
The B type viscosity at 200 nm and 25 ° C. was 100 cps. When this aqueous dispersion was allowed to stand at 40 ° C. for 60 days, no change in appearance was observed and, on the other hand, there was no change in viscosity, indicating extremely excellent storage stability. The obtained water dispersion was applied onto a glass plate so that the solid film thickness was 15 μm. When this coating film was air dried at room temperature for 1 hour and then immersed in distilled water, the coating film immediately dispersed in water and showed excellent redispersibility of rank 4.

The result of 125 MHz ¹³ C NMR of this aqueous dispersion measured in the same manner as in Example 1 shows that the half value width of the signal (160-175 ppm) of the carbon of the carbonyl group of the copolyester is ∞ (no signal is detected). The full width at half maximum of the carbon signal of the carbonyl group of methacrylic acid (181ppm-186ppm) was 110Hz. At the end of the grafting reaction, the sampled solution was dried under vacuum at 100 ° C for 8 hours to measure the acid value of the solid content, the polyester grafting efficiency (measurement of NMR), and the side chain of the graft by hydrolysis. The molecular weight was measured. Acid value of solid content is 2300
It was eq./10 ⁶ g. ^{In the 1} H NMR measurement, a signal derived from fumaric acid (δ = 6.8-6.9 ppm, doublet) was not detected at all, and thus the polyester grafting efficiency was 100%. Hydrolyze the copolyester part of the solid content,
When the molecular weight of the radical-polymerizable polymer was measured by GPC, the weight average molecular weight was 10,000.

Examples 13 to 14 With respect to 100 solid parts of each of the aqueous dispersions (B-1) and (B-2), 25 solid parts of melamine resin (Sumimar M30W, manufactured by Sumitomo Chemical Co., Ltd.) and para. Toluenesulfonic acid (catalyst) 0.25 solid parts, titanium oxide 100 parts, glass beads 2
A mixture of 50 parts was shaken and dispersed with a paint shaker for 5 hours. Then, the film thickness after drying on the zinc iron plate is 15μ
The coating film was applied so as to have a thickness of m and baked at 230 ° C. for 1 minute to form a cured coating film. The performance of the obtained cured coating film is shown in Table 5.

Comparative Example 8 A coating material and a coating film were obtained in exactly the same manner as in Example 13 except that (B-9) was used instead of the aqueous dispersion (B-1). The performance of the obtained cured coating film is shown in Table 5.

Comparative Example 9 In a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser, 466 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, 401 parts of neopentyl glycol, 443 parts of ethylene glycol, and tetra- Charge 0.52 parts of n-butyl titanate, 16
The transesterification reaction was carried out from 0 ° C to 220 ° C over 4 hours. Then add 23 parts of fumaric acid to 200 ℃ to 220 ℃
The temperature was raised to 1 hour, and the esterification reaction was carried out.
Then raise the temperature to 255 ° C and gradually reduce the pressure in the reaction system.
After reacting for 15 minutes under a reduced pressure of 0.2 mmHg, 19 parts of trimellitic anhydride was added, and the mixture was stirred at 220 ° C. for 1 hour under nitrogen to obtain polyester (A-11). Obtained polyester (A-1
1) was light yellow and transparent and had a weight average molecular weight of 4000. N
The composition measured by MR etc. was as follows. Dicarboxylic acid component terephthalic acid 47 mol% Isophthalic acid 47 mol% Fumaric acid 4 mol% Trimellitic acid 2 mol% Diol component neopentyl glycol 50 mol% Ethylene glycol 50 mol%

This polyester (A-11) was grafted in the same manner as in Example 1 and then dispersed in water. The resulting water dispersion (B-21) was white and had an average particle size of 80 nm and B at 25 ° C.
The mold viscosity was 200 cps. Further, using this dispersion, a paint and a coating film were obtained in the same manner as in Example 13. The performance of the obtained cured coating film is shown in Table 5.

Comparative Example 10 In a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser, 466 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, 401 parts of neopentyl glycol, 443 parts of ethylene glycol, and tetra- Charge 0.52 parts of n-butyl titanate, 16
The transesterification reaction was carried out from 0 ° C to 220 ° C over 4 hours. Then, 67 parts of 5-sodium sulfoisophthalic acid was added and the temperature was raised from 200 ° C to 220 ° C over 1 hour to carry out an esterification reaction. Then, the temperature was raised to 255 ° C., the pressure of the reaction system was gradually reduced, and the reaction was conducted under a reduced pressure of 0.2 mmHg for 1 hour and 30 minutes to obtain polyester (A-12). The resulting polyester (A-12) is light yellow and transparent and has a weight average molecular weight of 25,000.
Met. The composition measured by NMR and the like was as follows.

34 parts of this polyester (A-12) and 10.8 parts of ethylene glycol-n-butyl ether were placed in a container and stirred at 150 to 170 ° C. for about 2 hours to obtain a uniform and viscous melt. , 55.2 parts of water was gradually added with vigorous stirring, and after about 1 hour, a uniform, pale bluish white aqueous dispersion (B-22)
Got The resulting aqueous dispersion on a glass plate, solid film thickness
When it was applied to have a thickness of 15 μm, dried at room temperature for 1 hour and then immersed in distilled water, the appearance of the coating film did not change at all and showed no redispersibility. Further, using this dispersion, a paint and a coating film were obtained in the same manner as in Example 13. The performance of the obtained cured coating film is shown in Table 6.

Comparative Example 11 In a stainless steel reactor equipped with a stirrer, a thermometer and a partial reflux condenser, 388 parts of adipic acid, 339 parts of isophthalic acid, 85 parts of maleic anhydride, 112 parts of benzoic acid, dimethylpropionic acid. 90 parts, neopentyl glycol 692
Parts, 77 parts of water, and 1.5 parts of dibutyltin oxide were charged, and the reaction was carried out at 149 ° C. for 1.5 hours and at 193 ° C. to 210 ° C. for 4 hours to carry out an esterification reaction to obtain a polyester (A-13). The resulting polyester (A-13) was light yellow and transparent and had a weight average molecular weight of 1,000.

When this polyester (A-13) was dispersed in water in the same manner as in Example 1, the resulting aqueous dispersion (B-23) was white and had an average particle size of 300 nm and a B-type viscosity at 25 ° C. of 100.
It was above ps (measurement was impossible because of high viscosity). To 5 g of this aqueous dispersion, 1.25 g of heavy water was added to adjust the solid content concentration to 20% by weight, and then DSS was added to obtain 125 MHz ¹³ CNM of this aqueous dispersion.
R was measured. The full width at half maximum of the carbon signal of the carbonyl group of the copolyester was 150 Hz, and the full width at half maximum of the signal of the carbon atom of the carbonyl group of methacrylic acid was 200 Hz. Further, using this dispersion, a paint and a coating film were obtained in the same manner as in Example 13. The performance of the obtained cured coating film is shown in Table 6.

Example 15 In a reactor equipped with a stirrer, a thermometer, a reflux device and a metering dropping device, 75 parts of polyester resin (A-1) and methyl ethyl ketone were added.
Add 56 parts and 19 parts of isopropyl alcohol and heat at 65 ℃,
The resin was dissolved by stirring. After the resin was completely dissolved, a mixture of 15 parts of chloromethylstyrene and 10 parts of ethyl acrylate, and a solution of 1.5 parts of azobisisobutyronitrile and 2.5 parts of mercaptoethanol in 25 parts of methyl ethyl ketone were added at 0.2 ml / min. Then, drop it into the polyester solution and add 2 more.
Stirring was continued for hours. After sampling for analysis (5 g) from the reaction solution, 19.2 parts of triethylamine was added to the reaction solution, 200 parts of water adjusted to pH 3 with acetic acid was added, and the mixture was stirred for 1 hour. Then, the temperature of the dispersion was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off. The resulting aqueous dispersion (B-24) was white and had an average particle size of 300 nm and a B-type viscosity at 25 ° C of 40 cps.

To 5 g of this aqueous dispersion, 1.25 g of heavy water was added to adjust the solid content concentration to 20% by weight, and then DSS was added, and 125 MHz was added.
¹³ C NMR was measured. The full width at half maximum of the signal (160-175 ppm) of the carbon of the carbonyl group of the copolyester was ∞ (no signal was detected). This water dispersion at 40 ℃
After being left for 60 days, no change in appearance was observed, and on the other hand, there was no change in viscosity, indicating excellent storage stability. The obtained water dispersion was applied onto a glass plate so that the solid film thickness was 15 μm. When this coating film is air dried at room temperature for 1 hour and then immersed in distilled water, the coating film immediately disperses in water and ranks 4-5.
Showed excellent redispersibility. At the end of the grafting reaction, the sampled solution was dried under vacuum at 100 ° C for 8 hours to measure the acid value of the solid content, the polyester grafting efficiency (measurement of NMR), and the side chain of the graft by hydrolysis. The molecular weight was measured. ^{In 1} H NMR measurement, the signal derived from fumaric acid (δ = 6.8-6.9 ppm,
Since no doublet) was detected at all, the polyester grafting efficiency was 100%. The weight-average molecular weight was 9,000 when the copolymerized polyester part of the solid content was hydrolyzed and the molecular weight of the radical-polymerizable polymer was measured by GPC. The hydrophilic group in the radical polymer chain in this dispersion was a quaternary ammonium salt.

[0095]

[Table 2]

[0096]

[Table 3]

[0097]

[Table 4]

[0098]

[Table 5]

[0099]

[Table 6]

[0100]

Industrial Applicability The polyester aqueous dispersion of the present invention has excellent redispersibility, and when the coating resin composition prepared therefrom is applied to metal or plastic, the coating film has excellent appearance and processability, and is water resistant. It has excellent properties. Therefore, it is useful for paints, inks, coating agents, adhesives, and various processing agents.

[Brief description of drawings]

FIG. 1 125 of a representative water dispersion of the invention (Example 1).
It is a figure which shows a MHz < ¹³ > C NMR spectrum.

FIG. 2 125 of a representative water dispersion of the invention (Example 2)
It is a figure which shows a MHz < ¹³ > C NMR spectrum.

FIG. 3 125 of a representative water dispersion of the invention (Example 5)
It is a figure which shows a MHz < ¹³ > C NMR spectrum.

FIG. 4 125 of a representative water dispersion of Comparative Example (Comparative Example 1)
It is a figure which shows a MHz < ¹³ > C NMR spectrum.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-55-149353 (JP, A) JP-A-59-223374 (JP, A) JP-B-61-57874 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) C08F 283/01 C08F 2/06 C08J 3/07

Claims (5)

(57) [Claims] 1. A total of dicarboxylic acid components containing a polymerizable unsaturated group.
A graft polymer obtained by graft-polymerizing a radical-polymerizable monomer containing a hydrophilic group-containing radical-polymerizable monomer into a copolymerized polyester resin obtained by copolymerizing 2 to 7 mol% with respect to an acid component is obtained. A copolyester resin-based water dispersion dispersed in water or a mixed solvent of water and a water-soluble organic solvent, wherein the graft polymer is dispersed in fine particles having an average particle size of 500 nm or less. Copolyester resin-based water dispersion. 2. The copolymerized polyester resin itself does not dissolve or disperse in water , and the hydrophilic group of the hydrophilic group-containing radical-polymerizable monomer is a carboxyl group. At least one of the carboxyl groups
The copolymerized polyester resin-based water dispersion according to claim 1, wherein a part thereof is neutralized with a basic compound. 3. A graft polymer of the particulate core portion copolymerized polyester, copolymerized polyester resin aqueous dispersion according to claim 1 or 2, the shell portion forms a core-shell structure of the graft polymer chains. 4. The graft polymer according to claim 1, wherein the graft chain of the graft polymer is composed of two or more kinds of radically polymerizable monomers having a copolymerization reactivity ratio to diethyl fumarate in the range of 1 to 12 . An aqueous dispersion of any one of the copolyester resins. 5. A dicarboxylic acid component containing a polymerizable unsaturated group
A copolymerizable polyester resin containing 2 to 7 mol% and a radical polymerizable monomer containing a carboxyl group-containing radical polymerizable monomer are copolymerized with a water-soluble organic solvent that is a good solvent for the copolymerized polyester resin. After reacting with a poor solvent of the polyester resin in a mixed solvent with a good solvent of the polymer chain of the radical-polymerizable monomer to obtain a graft polymer, the graft polymer is neutralized with a basic compound. A method for producing a copolyester resin-based dispersion, which is dispersed in water or a mixed solvent of water and a water-soluble organic solvent.