JP2000119539A - Production of aqueous dispersion of polymer containing compound having carbodiimide group, production of aqueous dispersion of polymer having carbodiimide group and aqueous dispersion of polymer obtained by each production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an aqueous dispersion excellent in preservation stability and suitable for a water-based printing ink by polymerizing a radically polymerizable unsaturated monomer in an aqueous dispersion of a compound having carbodiimide group and the monomer. SOLUTION: A compound a1 having carbodiimide group without any radically polymerizable unsaturated double bond, e.g. tetramethylxylylene carbodiimide and a radically polymerizable unsaturated monomer b1 without having a functional group reactive with the carbodiimide, e.g. methyl (meth)acrylate are dispersed in water with a surfactant to provide dispersed particles having <=1.0 μm average particle diameter. The monomer b1 is then polymerized to produce an aqueous dispersion of a polymer containing the compound a1 having the carbodiimide group without any radically polymerizable undsaturated double bond and having <=0.8 μm average particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aqueous dispersion of a polymer containing a compound having a carbodiimide group,
The present invention relates to a method for producing an aqueous dispersion of a polymer having a carbodiimide group, and an aqueous printing ink comprising an aqueous dispersion of each polymer obtained by each production method.

[0002]

2. Description of the Related Art In recent years, solvent-based paints and inks, which have been widely used in various fields, have been converted to water-based paints in the ink, paint, adhesive, and other industries in order to control the release of organic solvents and take measures for environmental safety. This has been widely practiced, and for some applications, almost complete aqueous conversion has been achieved. Such inks and paints are required to have various qualities depending on the purpose of use, but the water-based type is inferior to the conventional solvent type in that it has poor water resistance and solvent resistance. There are disadvantages. These resistances are greatly affected by the resin type, the resin composition, and the resin form of the binder, and are also greatly improved by using a binder resin and a crosslinking agent therefor.

As a crosslinking agent for a water-based ink or a binder resin for a paint, a hydrazide compound, an aziridine compound, a blocked isocyanate compound, a compound having a carbodiimide group, and the like have already been proposed. Above all, compounds having a carbodiimide group, which can react with a compound having active hydrogen such as -COOH or -OH and form a crosslinked structure, have been widely applied because they can be crosslinked at a low temperature.

However, conventionally, when a compound having a carbodiimide group is used as a cross-linking agent for a binder resin for aqueous inks or coatings, there have been the following various disadvantages. For example, in order to use a compound having a carbodiimide group in an aqueous system, a compound having a carbodiimide group is emulsified by applying a high shearing force in the presence of a relatively high concentration of a surfactant to obtain an aqueous dispersion. But,
For this purpose, a compound having a carbodiimide group, a surfactant, and water are mixed under a high shearing force, and a special device for emulsifying and dispersing is required, which is not only versatile but also not preferable in terms of energy saving. In addition, urea is inevitably generated by the reaction of a compound having a carbodiimide group with water due to emulsification / dispersion under strong energy, which has a problem of shortening the storage stability of the compound itself.
Also, with a relatively high concentration of surfactant, even though the compound having a carbodiimide group is emulsified / dispersed, the thin layer of the surfactant only covers the compound having the carbodiimide group, The aqueous dispersion of the compound having a carbodiimide group had poor storage stability.

To solve such a problem, Japanese Unexamined Patent Publication No. Sho 63-2
Japanese Patent No. 64128 discloses a surface-active carbodiimide compound obtained by introducing a part that functions as a surfactant into a compound having a carbodiimide group itself.However, in order to use a compound having a carbodiimide group in an aqueous system, However, it is still difficult to avoid side reactions with water, and there is a problem in the storage stability of the aqueous dispersion of the compound having a carbodiimide group itself.

Further, there is another problem in addition to the storage stability of the aqueous dispersion of the compound having a carbodiimide group. That is, the binder resin for water-based inks and coatings is -CO to secure solubility or dispersibility in water.
It is common to have an active hydrogen group such as OH or -OH, but because of the high reactivity between the carbodiimide group in the cross-linking agent and the active hydrogen group in the binder resin, the cross-linking agent is used in inks and paints. The carbodiimide group contained therein reacts with the active hydrogen group in the binder resin to increase the viscosity, and the pot life as an ink, paint, adhesive or the like is shortened.

[0007]

SUMMARY OF THE INVENTION The present invention provides an aqueous dispersion of a crosslinking agent having a carbodiimide group and excellent storage stability against water and a binder resin having -COOH or the like without using a special apparatus. A water-based printing ink having excellent storage stability by using an aqueous dispersion of a crosslinking agent having the carbodiimide group, and having excellent adhesion to various substrates and excellent boil resistance. It is an object to provide an aqueous printing ink capable of forming a printing layer.

[0008]

Means for Solving the Problems In view of the above objects, the present inventors have conducted intensive studies on a method for producing an aqueous dispersion of a crosslinking agent having a carbodiimide group. The present inventors have found that a dispersion obtained by dispersing a radical polymerizable unsaturated monomer into droplets having a specific particle size and then polymerizing the same in water has extremely excellent storage stability, and thus completed the present invention. That is, the first invention is:
Compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond using surfactant (c)
And a mixture of a radical polymerizable unsaturated monomer (b1) having no functional group capable of reacting with a carbodiimide group is dispersed in water to obtain dispersed particles having an average particle size of 1.0 μm or less. A method for producing an aqueous dispersion of a polymer containing the compound (a1) having a carbodiimide group, wherein the radical polymerizable unsaturated monomer (b1) is polymerized.

In a second aspect of the present invention, a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond and a functional group capable of reacting with the carbodiimide group are prepared using a surfactant (c). The mixture with the radical polymerizable unsaturated monomer (b2) is dispersed in water.
After obtaining dispersed particles having a particle size of 0 μm or less, the radical polymerizable unsaturated monomer (b2) is polymerized, and a part of the carbodiimide group in the compound (a1) having a carbodiimide group is combined with the radical polymerizable unsaturated monomer. A method for producing an aqueous dispersion of a polymer having a carbodiimide group, which comprises reacting a carbodiimide group in a monomer (b2) with a functional group capable of reacting.

[0010] A third invention relates to a compound (a2) having a carbodiimide group and a radical polymerizable unsaturated double bond using a surfactant (c) and a radical having no functional group capable of reacting with the carbodiimide group. A mixture with the polymerizable unsaturated monomer (b1) was dispersed in water, and the average particle size was 1.
An aqueous solution of a polymer having a carbodiimide group, which is obtained by copolymerizing the compound having a carbodiimide group (a2) and the radically polymerizable unsaturated monomer (b1) after obtaining dispersed particles having a particle size of 0 μm or less. This is a method for producing a dispersion.

A fourth aspect of the present invention is a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond and a radically polymerizable compound having a functional group capable of reacting with a carbodiimide group using a surfactant (c). Unsaturated monomer (b
The mixture with 2) was dispersed in water, and the average particle size was 1.0 μm.
m is obtained, and then the compound (a2) having a carbodiimide group and the radically polymerizable unsaturated monomer (b2) are copolymerized and the carbodiimide in the compound (a2) having a carbodiimide group is obtained. A method for producing an aqueous dispersion of a polymer having a carbodiimide group, comprising reacting a part of the group with a functional group capable of reacting with a carbodiimide group in the radically polymerizable unsaturated monomer (b2). is there.

According to a fifth aspect of the present invention, the surfactant (c) has a radically polymerizable unsaturated double bond, and the aqueous solution of the polymer containing the compound having a carbodiimide group according to the first aspect of the present invention is characterized in that This is a method for producing a dispersion.

A sixth aspect of the present invention is the polymer having a carbodiimide group according to any one of the second to fourth aspects, wherein the surfactant (c) has a radically polymerizable unsaturated double bond. Is a method for producing an aqueous dispersion.

A seventh aspect of the present invention is an aqueous dispersion of a polymer containing a compound having a carbodiimide group obtained by the production method according to the first or fifth aspect.

An eighth invention is an aqueous dispersion of a polymer having a carbodiimide group obtained by the production method according to any one of the second to fourth and sixth inventions.

A ninth invention is the aqueous dispersion according to the seventh invention, wherein the average particle size of the polymer containing the compound having a carbodiimide group is 0.8 μm or less.

A tenth invention is the aqueous dispersion according to the eighth invention, wherein the average particle size of the polymer having a carbodiimide group is 0.8 μm or less.

An eleventh invention is directed to an aqueous printing ink comprising the aqueous dispersion according to any one of the seventh to tenth inventions.

A twelfth invention is the aqueous printing ink according to the eleventh invention, which comprises an aqueous resin having a functional group capable of reacting with a carbodiimide group.

The functional group capable of reacting with the carbodiimide group is
The aqueous printing ink according to the twelfth aspect, which is -COOH.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first invention will be described. In the first invention, as described above, a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond is first reacted with a carbodiimide group using a surfactant (c). The mixture with the obtained radical polymerizable unsaturated monomer having no functional group (b1) is converted into dispersion particles having an average particle size of 1.0 μm or less in advance, and then the radical polymerizable unsaturated monomer (b1) is polymerized. It is important to. That is, since a compound having a carbodiimide group is generally poorly soluble in water, when a radically polymerizable unsaturated monomer is simply polymerized in water in the presence of such a compound having a carbodiimide group, an aggregate is generated. Not only is it easy to perform and lacks storage stability, but even if printing is performed using an aqueous printing ink obtained using the obtained aqueous dispersion, a printed material satisfying the required quality cannot be obtained. Therefore, the compound (a1) having a carbodiimide group and the radical polymerizable unsaturated monomer (b1) are sufficiently mixed, and the compound (a1) having a carbodiimide group is preferably mixed with the radical polymerizable unsaturated monomer (b1). After dissolving in water, surfactant (c)
After dispersing the mixture in water (after forming a pre-emulsion) so that the mixture becomes dispersed particles having an average particle size of 1.0 μm or less, the radical polymerizable unsaturated monomer (b
By polymerizing 1), an aqueous dispersion with few aggregates can be obtained. Regarding the generation of aggregates during the polymerization, it is preferable that the dispersed particles of the mixture before polymerization are smaller, but the compound (a1) having a carbodiimide group
Is dissolved in the radical polymerizable unsaturated monomer (b1), the viscosity is higher than that of only the radical polymerizable unsaturated monomer (b1), so that it is more difficult to reduce the particle diameter. Often. In such cases, a homomixer, homogenizer, microfluidizer (manufactured by Mizuho Industry Co., Ltd.)
When a mixture of the compound (a1) having a carbodiimide group and the radically polymerizable unsaturated monomer (b1) is emulsified and dispersed under high shearing force using a method such as the above, a pre-emulsion having a smaller dispersed particle size is obtained. Good.

The compound (a1) having a carbodiimide group used in the first invention has no radically polymerizable unsaturated bond. On the other hand, the radical polymerizable unsaturated monomer (b1) does not have a functional group capable of reacting with a carbodiimide group. Therefore, even if the radically polymerizable unsaturated monomer (b1) in the pre-emulsion is polymerized in the first invention, the polymer obtained and the compound (a1) having a carbodiimide group are particularly chemically bonded. Not necessarily.
However, after mixing the radical polymerizable unsaturated monomer (b1) and the compound (a1) having a carbodiimide group,
Since the radically polymerizable unsaturated monomer (b1) is polymerized in the presence of the compound (a1) having a carbodiimide group, the compound (a1) having a carbodiimide group is integrally formed in the obtained polymer. It is considered to be included. And a compound (a1) having a carbodiimide group
However, it is considered that, since the carbodiimide group was present in the polymer, the storage stability as a whole could be improved in an aqueous system because the carbodiimide group was present.

The compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond used in the first invention is a compound having at least a carbodiimide group, ie, -N = C = N- in a molecule. A compound having one and not having a radically polymerizable unsaturated double bond, particularly preferably a compound having 1 to 4 carbodiimide groups in a molecule. As one method for obtaining the compound (a1) having such a carbodiimide group, in an organic solvent in the presence of a catalyst,
There is a method of removing carbon dioxide from an isocyanate compound at 100 to 200 ° C. At 100 ° C. or lower, the reaction requires a long time, and at 200 ° C. or higher, side reactions are likely to occur. Such a reaction is preferably performed under a nitrogen atmosphere.

Compound (a1) having a carbodiimide group
Monoisocyanate and polyisocyanate compounds are examples of the isocyanate compound which is a raw material of the above. For example, monoisocyanates include methyl isocyanate, ethyl isocyanate, propyl isocyanate,
Butyl isocyanate, octadecyl isocyanate,
Examples of polyisocyanates such as phenyl isocyanate include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethyl xylylene diisocyanate.

Examples of the catalyst used for the carbodiimidization reaction include phosphorene and phosphorene oxides. Specifically, there are 1-ethyl-3-methyl-3-phospholene oxide, 1-phenyl-3-methyl-3-phospholene oxide, 1-phenyl-3-methyl-2-phospholene oxide and the like.

It is necessary that the organic solvent used in the carbodiimidization reaction has a high boiling point and does not have active hydrogen which reacts with the isocyanate compound as a raw material and the compound (a1) having a carbodiimide group to be formed. It is. Examples include aromatic hydrocarbons such as toluene, xylene, and diethylbenzene; diethylene glycol diacetate, dipropylene glycol dibutyrate, hexylene glycol diacetate, glycol diacetate, methyl glycol acetate, ethyl glycol acetate, butyl glycol acetate, and ethyl. Glycol ethers such as diglycol acetate and butyl diglycol acetate; ketones such as ethyl butyl ketone, acetophenone, propiophenone, diisobutyl ketone and cyclohexanone; aliphatic esters such as aluminum acetate, propyl propionate and ethyl butyrate; is there. The formation of the carbodiimide group is 2260c
It can be confirmed by disappearance of the absorption peak of the isocyanate group of m- ¹ and generation of the absorption peak of the carbodiimide group.

Compound having carbodiimide group (a1)
In addition to the basic method described above, for example, US Pat.
JP-A-41,956, JP-B-47-33279, JP-A-5-178954, JP-A-7-330649, and the like. Org. Chem. , 2
8, 2069 (1963), Chem. , Review
81, 619 (1981). Recently, Japanese Patent Application Laid-Open No. 5-178954 has been proposed.
As described in JP-A-6-56950 and JP-A-6-56950, the reaction can be carried out without using any solvent.

Compound having carbodiimide group (a1)
Commercially available products include, for example, luplanate MM-103 and XTB-3003 (B) as monocarbodiimides using diphenylmethane diisocyanate (MDI) as a raw material.
ASF Co., Ltd.), Stabacol P (Sumitomo Bayer Urethane Co., Ltd.), and carbodilite V-03, V-05, etc. (Nisshinbo Co., Ltd.) as polycarbodiimides using tetramethylxylylene diisocyanate as a raw material. Can be The compound (a1) having a carbodiimide group has at least one isocyanate group derived from an isocyanate compound as a raw material in addition to -N = C = N-.

The radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group used in the first invention includes methyl (meth) acrylate, ethyl (meth) acrylate, Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, (Meth) such as nonyl methacrylate, lauryl (meth) acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, and ethoxybutyl (meth) acrylate
Acrylic acid alkyl ester; unsaturated monomer having an amide group such as acrylamide, N-butoxymethyl (meth) acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide; N, N-dimethylamino Ethyl methacrylate, N, N-diethylaminoethyl methacrylate,
(Meth) acrylic acid having a tertiary amino group such as N, N-dimethylaminopropyl methacrylate; nitrogen-containing unsaturated monomer such as N-vinylpyrrolidone, N-vinylimidazole, N-vinylcarbazole; cyclopentyl (meth) Alicyclic (meth) acrylates such as acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate; aromatic unsaturated monomers such as styrene, α-methylstyrene, and phenyl methacrylate; octafluoropentyl (meth) acrylate And fluorine-containing unsaturated monomers such as perfluorocyclohexyl (meth) acrylate; and monomers having one unsaturated group such as unsaturated monomers having blocked isocyanate groups. Further, bifunctional unsaturated monomers such as divinylbenzene and polyethylene glycol di (meth) acrylate can also be used.

As the surfactant (c) used in the first invention for obtaining the pre-emulsion, any of nonionic, anionic and cationic surfactants can be used. From the viewpoint of stability over time, nonionic and anionic activators are particularly preferred. Nonionic activators include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene alkyl ether such as polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether;
Polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene dodecyl phenyl ether; sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate such as polyoxyethylene alkyl ester and polyoxyethylene alkyl phenyl ester , Sorbitan distearate, sorbitan monooleate, sorbitan fatty acid esters such as sorbitan triolate,
Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate. There are polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate. Examples of the anionic property include an alkyl sulfate, an alkylbenzene sulfonate, a naphthalene sulfonate, and an alkyl sulfosuccinate.

In the first invention, in order to polymerize the radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group in the pre-emulsion, a known radical polymerization initiator may be used. As the polymerization initiator, both a water-soluble initiator and an oil-soluble initiator can be used. When an oil-soluble initiator is used, the radically polymerizable unsaturated monomer (b1) is used before forming the pre-emulsion.
It is preferable to dissolve it in On the other hand, when using a water-soluble initiator, before forming a pre-emulsion,
When forming, after formation, it can be appropriately added to the reaction system. These polymerization initiators are suitably used in the range of 0.05 to 5% based on the radical polymerizable unsaturated monomer (b1). The temperature during the polymerization is preferably 40 to 100 ° C,
When a redox initiator is used, 80 ° C. or less is sufficient. As the polymerization initiator, azobisisobutyronitrile, azo compounds such as azobisisobutylvaleronitrile, benzoyl peroxide, isobutyryl peroxide,
Octanoyl peroxide, cumyl peroxy octate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy acetate, lauryl peroxide, di-t-butyl peroxide, di-2-ethylhexyl peroxy There are inorganic peroxide compounds such as organic peroxides such as zinc carbonate, potassium persulfate, ammonium persulfate, and hydrogen peroxide. Organic or inorganic peroxide compounds can also be used as redox initiators in combination with reducing agents. Examples of the reducing agent to be used include L-ascorbic acid, L-sorbic acid, sodium metabisulfite, ferric sulfate, ferric chloride, Rongalit and the like.

In the first invention, when the radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group in the pre-emulsion is polymerized, the pre-emulsion may be completely charged into a reaction vessel. The whole pre-emulsion may be dropped into a reaction vessel with or without water, or a part of the pre-emulsion may be charged into the reaction vessel and the remaining pre-emulsion may be dropped therein. In the polymerization, a known chain transfer agent such as octyl mercaptan, lauryl mercaptan, 2-mercaptoethanol, terchardodecyl mercaptan, or thioglycolic acid may be used for the purpose of controlling the molecular weight.

Next, the second invention will be described. The compound (a1) having a carbodiimide group used in the first invention and the radically polymerizable unsaturated monomer (b)
1) does not particularly have a functional group capable of chemically bonding, whereas the radically polymerizable unsaturated monomer (b2) used in the second invention can react with a carbodiimide group. It has a functional group. That is, the second invention uses a surfactant (c) to prepare a compound (a) having a carbodiimide group and no radically polymerizable unsaturated double bond.
A mixture of 1) and a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with a carbodiimide group is converted into dispersed particles having an average particle size of 1.0 μm or less in advance, and then the radically polymerizable unsaturated When polymerizing the monomer (b2), a part of the carbodiimide group in the compound (a1) having a carbodiimide group and a functional group capable of reacting with the carbodiimide group in the radically polymerizable unsaturated monomer (b2) Wherein the polymer in the aqueous dispersion obtained by such a method has a carbodiimide group derived from the compound (a1) having a carbodiimide group.

The radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with a carbodiimide group used in the second invention includes (meth) acrylic acid, itaconic acid, crotonic acid and the like having a carboxyl group. A 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, or the like having a hydroxyl group. In the second invention, only the radical polymerizable unsaturated monomer (b2) can be used, or the radical polymerizable unsaturated monomer having no functional group capable of reacting with the carbodiimide group used in the first invention can be used. Although the saturated monomer (b1) can be used in combination, the compound (a) having a carbodiimide group after polymerization (a
In order to leave the carbodiimide group derived from 1) in the polymer, it is preferable to use the radical polymerizable unsaturated monomer (b1) in combination, rather than using only the radical polymerizable unsaturated monomer (b2). Rather, it is preferable to mainly use the radical polymerizable unsaturated monomer (b1).

When a monomer having a carboxyl group is used as the radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with the carbodiimide group, it is mixed with the compound (a1) having a carbodiimide group. You can neutralize the carboxyl group with a basic compound before,
Alternatively, the carboxyl group can be neutralized before polymerization after mixing, or the carboxyl group that has not reacted with the carbodiimide group after polymerization can be neutralized. By neutralizing the carboxyl group before polymerization, the reaction with the carbodiimide group of polymerization is moderately suppressed,
It is suitable for reacting a neutralized carboxyl group in the radical polymerizable unsaturated monomer (b2) with a part of the carbodiimide group in the compound (a1) having a carbodiimide group. Examples of the basic compound used include sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, and dimethylamine. , Diethylamine, triethylamine, N, N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol,
Examples include morpholine and the like, which are used alone or in combination. In neutralizing a compound having a carboxyl group, 0.6 to 1.2 equivalents are preferably used per equivalent of the carboxyl group.
Since the carboxyl group easily reacts with the carbodiimide group, the reaction can be reduced by neutralizing the carboxyl group in advance.

The compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond, the surfactant (c), the polymerization initiator and the like used in the second invention are as follows:
The same ones as in the first invention can be exemplified, and the method of preparing the pre-emulsion, the polymerization method, and the like are the same as those in the first invention.

Next, the third invention will be described. Third
Is a case where the compound (a2) having a carbodiimide group and the radically polymerizable unsaturated monomer (b1) are chemically bonded. That is, the third invention relates to a method for producing a compound (a2) having a carbodiimide group and a radical polymerizable unsaturated double bond using a surfactant (c) and a radical polymerization having no functional group capable of reacting with the carbodiimide group. A mixture with the unsaturated monomer (b2) is converted into dispersed particles having an average particle diameter of 1.0 μm or less in advance, and then the compound (a2) having a carbodiimide group and the radical polymerizable unsaturated monomer (b1) Wherein the copolymer in the aqueous dispersion obtained by such a method is a compound (a2) having a carbodiimide group.
Has a carbodiimide group derived from

A third invention is a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond,
A mixture of a radical polymerizable unsaturated monomer (b1) having no functional group capable of reacting with a carbodiimide group is dispersed in water to obtain dispersed particles having an average particle size of 1.0 μm or less. A method for producing an aqueous dispersion of a polymer having a carbodiimide group, comprising copolymerizing a compound (a2) having the formula (I) and the radical polymerizable unsaturated monomer (b1).

The compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond used in the third method is a compound (a1) having a carbodiimide group, that is, at least one isocyanate group in the molecule. And a compound having a carbodiimide group and a monomer having a hydroxyl group and a radically polymerizable unsaturated double bond. In this case, a monomer having a hydroxyl group and a radically polymerizable unsaturated double bond is used in an amount of 1 to 1 equivalent of the isocyanate group.
Preferably, the reaction is carried out without solvent in an amount of 1.2 equivalents (the number of hydroxyl groups).

As the monomer having a hydroxyl group and a radically polymerizable unsaturated double bond used for obtaining the compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond, 2-hydroxyethyl (meth) Examples include acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate.

The radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group used in the third invention, the surfactant (c), the polymerization initiator, and the like are the first and the second. Examples similar to those of the second invention can be exemplified, and the method of preparing the pre-emulsion, the polymerization method, and the like are the same as those of the first and second inventions.

Next, the fourth invention will be described. The fourth invention is a case where the compound (a2) having a carbodiimide group and the radically polymerizable unsaturated monomer (b2) are chemically bonded. That is, the fourth invention uses a surfactant (c) to prepare a compound (a2) having a carbodiimide group and a radical polymerizable unsaturated double bond, and a radical polymerizable compound having a functional group capable of reacting with the carbodiimide group. A mixture of the unsaturated monomer (b2) and the compound having a carbodiimide group (a2) and the radically polymerizable unsaturated monomer (b2) are prepared in advance as dispersed particles having an average particle size of 1.0 μm or less. During copolymerization, a part of the carbodiimide group in the compound having a carbodiimide group (a2) is reacted with a functional group capable of reacting with the carbodiimide group in the radically polymerizable unsaturated monomer (b2). The polymer in the aqueous dispersion obtained by such a method has a carbodiimide group derived from the compound (a2) having a carbodiimide group. And thus.

A compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond used in the fourth invention, a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with the carbodiimide group, The surfactant (c), the polymerization initiator, and the like can be the same as those in the second or third invention, respectively, and the method of preparing the pre-emulsion, the polymerization method, and the like are also the same as those in the first invention. It is.

The first to fourth inventions are summarized as follows.

[Table 1]

Next, the fifth and sixth inventions will be described. The fifth and sixth inventions relate to the case where the surfactant (c) having a radically polymerizable unsaturated double bond is used in each of the first to fourth inventions. When an aqueous dispersion of a polymer using a surfactant (c) having a radically polymerizable unsaturated double bond is used as a crosslinking agent for a binder for an aqueous printing ink, the water resistance of a printing layer can be improved. it can. As an example, an alkyl phenyl ether type (as a commercial product, HS-1 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
0, HS-20, RN-20, RN-30), sulfosuccinates (commercially available products: Latemul S-120P, S-180A manufactured by Kao Corporation, Elminol JS- manufactured by Sanyo Chemical Industries, Ltd.) 2 etc.). These surfactants
Use alone or as a mixture. The amount used is preferably in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the radical polymerizable component.

Next, the seventh to tenth aspects of the invention will be described. The seventh and eighth inventions are an aqueous dispersion of a polymer containing a compound having a carbodiimide group, or an aqueous dispersion of a polymer having a carbodiimide group, obtained by the above first to sixth production methods. Of the ten inventions,
A dispersoid of the aqueous dispersion, that is, a polymer containing a compound having a carbodiimide group, or an aqueous dispersion having a dispersed particle size (average particle size) of a polymer having a carbodiimide group of 0.8 μm or less. When the average particle size of the dispersoid is larger than 0.8 μm, the storage stability as an aqueous dispersion of a polymer containing a compound having a carbodiimide group, or an aqueous dispersion of a polymer having a carbodiimide group only deteriorates. Without, the storage stability of the aqueous printing ink using this aqueous dispersion as a cross-linking agent tends to be poor, as a result,
It is easy to impair the adhesion of the printing layer to the substrate and the boil resistance of the printing layer.

Next, the eleventh to thirteenth inventions will be described. An eleventh invention is an aqueous printing ink comprising the aqueous dispersion of any one of the seventh to tenth inventions. According to a twelfth aspect, a polymer containing a compound having a carbodiimide group or a polymer having a carbodiimide group is blended as a crosslinking agent with an aqueous resin (binder) having a functional group capable of reacting with a carbodiimide group. An aqueous printing ink, wherein each of the polymers is blended in the form of an aqueous dispersion. This water-based printing ink is water-resistant, despite being water-soluble, in a printing layer, a functional group capable of reacting with a carbodiimide group in an aqueous resin reacts with a carbodiimide group in a cross-linking agent, and is crosslinked to provide water resistance. ,
A printed material having excellent boil resistance and retort resistance can be provided.

In the twelfth invention, the mixing ratio of the aqueous resin in the aqueous printing ink and the crosslinking agent is not particularly limited, but is based on 1 equivalent of the functional group (number) capable of reacting with the carbodiimide group in the aqueous resin. It is preferable that the carbodiimide group (number) in the crosslinking agent is blended in a range of 0.1 to 5 equivalents. Examples of the functional group capable of reacting with the carbodiimide group in the aqueous resin include an active hydrogen group such as a carboxyl group, a hydroxyl group, and an amino group, and a carboxyl group is preferable. Examples of the aqueous resin used in the inventions 11 to 13 include a urethane resin, a polyester resin, and a polymer of an ethylenically unsaturated monomer each having the above functional group. Among them, a urethane resin is preferable, and a carboxyl group is particularly preferable. A urethane resin having a group is also preferable from the viewpoint of physical properties.

Examples of the pigment used in the aqueous printing inks of the first to thirteenth inventions include organic pigments such as azo, phthalocyanine and naphthol, and inorganic pigments such as titanium white, carbon black and calcium carbonate. The pigment can also be used in the form of a dry powder or a press cake containing undried moisture. The aqueous printing ink can be prepared by any formula, for example, can be obtained according to the following formula. That is, the dry powder or press cake of the pigment is ground and dispersed with a dispersion or solution of an aqueous resin, a dispersant for the pigment, and the like in a ball mill, a sand mill, or the like to obtain a pigment base. Next, if necessary, a dispersion or solution of an aqueous resin is further added, and an antifoaming agent, a thickener, a surfactant, an ultraviolet absorber, a light stabilizer and the like are appropriately added. The above-mentioned various additives can be added to the pigment base after the meat and dispersion as described above, and can also be added at the time of the meat and dispersion. Then, an aqueous dispersion according to any one of the seventh to tenth aspects of the present invention as a crosslinking agent component is added thereto, and further diluted with water, an alcohol solvent, or the like to a viscosity suitable for printing to obtain an aqueous printing ink. Alternatively, water, an alcohol solvent or the like is appropriately added to the pigment base, and after dilution to a viscosity suitable for printing, an aqueous dispersion according to any one of the seventh to tenth inventions, which is a crosslinking agent component, can be added. The method is general. As an alcohol solvent for dilution, methanol, ethanol, n-propanol, isopropanol and the like are used. The aqueous printing inks of the eleventh to thirteenth inventions are gravure or flexographic systems, and are made of polyethylene terephthalate (PE).
T), printed on a plastic film such as biaxially oriented polypropylene (OPP) or nylon (NY).

[0050]

EXAMPLES In the following Production Examples and Examples, "parts" means parts by weight unless otherwise specified. The particle size of the dispersoid in an emulsion (pre-emulsion) of a mixture of a compound having a carbodiimide group and a radical polymerizable unsaturated monomer, and a polymer containing a compound having a carbodiimide group obtained by polymerization The particle size of the dispersoid of the aqueous dispersion or the aqueous dispersion of the polymer having a carbodiimide group is determined by MICROTRA using a dynamic light scattering method using laser light.
C UPA (manufactured by Nikkiso Co., Ltd.).

Production Example 1 (Synthesis of Compound Having Carbodiimide Group) 4 equipped with a reflux cooling pipe, a gas introduction pipe, a stirrer, and a thermometer
The one-necked 2000 ml flask was replaced with dry nitrogen, 1400 parts of tetramethylxylylene diisocyanate and 28 parts of 3-methyl-1-phenyl-2-phospholene-1-oxide were added, and the temperature was raised to 180 ° C. and reacted for 20 hours. Thus, tetramethylxylylenecarbodiimide (A) having isocyanate groups at both ends was obtained.

Production Example 2 (Synthesis of Compound Having Carbodiimide Group) 4 equipped with a reflux cooling pipe, a gas introduction pipe, a stirrer, and a thermometer
A 2000 ml flask with a one-necked head was replaced with dry nitrogen, 1400 parts of isophorone diisocyanate, 30 parts of 3-methyl-1-phenyl-2-phospholene-1-oxide and 300 parts of butyl carbitol acetate were added, and the temperature was raised to 145 ° C. The reaction was carried out for 10 hours to obtain isophorone carbodiimide (B) having isocyanate groups at both terminals.

Production Example 3 (Synthesis of Compound Having Carbodiimide Group and Radical-Polymerizable Unsaturated Double Bond) 4 equipped with a reflux cooling pipe, a gas introduction pipe, a stirrer, and a thermometer
A 2000 ml flask with a neck was replaced with dry nitrogen, and 1000 parts of tetramethylxylylenecarbodiimide having an isocyanate group (V-05, manufactured by Nisshinbo Industries, Inc.), 130 parts of 2-hydroxyethyl acrylate, and 1 part of dibutyltin dilaurate were charged. The temperature was raised to 100 ° C., and the mixture was reacted for 10 hours to obtain tetramethylxylylenecarbodiimide (C) having an unsaturated group at the terminal.

Production Example 4 (Synthesis of Aqueous Dispersion of Urethane Resin) 4 equipped with a reflux cooling pipe, a gas introduction pipe, a stirrer, and a thermometer
A 2000 ml flask with a one-necked head was replaced with dry nitrogen, and 61.2 parts of diphenylmethane diisocyanate, 189 parts of poly (3-methyl-1,5-pentane adipate) diol having a number average molecular weight of about 2,000 and a hydroxyl value of 56 (mg KOH /) were prepared. Add 30.3 parts of polyethylene glycol having an average molecular weight of about 1,000 and a hydroxyl value of 111 (mg KOH /), 19.5 parts of dimethylolbutanoic acid, 0.1 part of dibutyltin dilaurate, and 600 parts of methyl ethyl ketone (MEK). Thus, a solution of a urethane resin having a number average molecular weight of 15,800 and having -COOH was obtained. The urethane resin solution was cooled to 30 ° C., and after adding 18 parts of ammonia water and 660 parts of distilled water, MEK was removed to obtain an aqueous dispersion of a urethane resin having a solid content of about 33%.

Production Example 5 (Synthesis of Aqueous Dispersion of Acrylic Resin) A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and isopropyl alcohol ( (IPA) 600 parts were charged and heated to 80 ° C. Next, a mixture of 130 parts of methyl methacrylate, 130 parts of butyl acrylate, 20 parts of 2-hydroxyethyl acrylate, 20 parts of acrylic acid, and 6 parts of azobisisobutyronitrile was dropped into the IPA over 2 hours. The reaction was carried out for an hour to obtain an acrylic resin solution having -COOH. The acrylic resin solution thus obtained was cooled to 30 ° C., neutralized with aqueous ammonia, and after adding 660 parts of distilled water, IPA was removed to obtain an aqueous acrylic resin dispersion having a solid content of about 30%. .

Example 1 140 parts of tetramethylxylylenecarbodiimide obtained in Production Example 1, 70 parts of methyl methacrylate (MMA), 80 parts of butyl acrylate (BA), 3 parts of azobisisobutyronitrile (AIBN), 3 parts of “Leveno -WZ "(anionic emulsifier manufactured by Kao Corporation) 10 parts and ion exchange water 600 parts to prepare a pre-emulsion having an average particle size of the dispersoid of 0.9 µm in advance, and add this to a dropping funnel. To prepare. 100 parts of water was charged into a four-necked 1000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer, and stirring was started, and the temperature was raised to 80 ° C. in a nitrogen stream. The pre-emulsion was added dropwise over 2 hours while maintaining the internal temperature at 80 ° C. After the completion of dropping, further at 80 ° C, 2
The reaction was carried out for an hour to obtain an aqueous dispersion (A) of a polymer containing a compound having a carbodiimide group. When the average particle size of the dispersoid of the dispersion was measured by a dynamic light scattering method, it was 0.7 μm.
Met.

Examples 2 to 5, Comparative Examples 1 and 2 Aqueous dispersions (B) to (D) of polymers containing a compound having a carbodiimide group in the same manner as in Example 1 except for the formulations shown in Table 2. , (R-1), (R-2) and an aqueous dispersion (E) of a polymer having a carbodiimide group were obtained.

The aqueous dispersion of the polymer containing the compound having a carbodiimide group and the aqueous dispersion of the polymer having a carbodiimide group obtained in Examples 1 to 5 and Comparative Examples 1 and 2, the presence or absence of aggregates, storage stability The sex was evaluated. The results are shown in Table 2. a) Presence or absence of aggregates 物 No aggregates. ○ Almost no aggregates. △ Aggregates are slightly formed. X: considerable agglomerates are formed. b) Water dispersibility Stability when stored in a thermostat at 40 ° C. for 7 days ◎ Very good water dispersibility. ○ Good water dispersibility. △ Water dispersibility is slightly poor. × Poor water dispersibility.

[0059]

[Table 2]

Example 6 (Production of Water-Based Printing Ink) 100 parts of an aqueous dispersion of an aqueous urethane resin obtained in Production Example 4, 40 parts of a phthalocyanine-based blue pigment (Lionol Blue KLH manufactured by Toyo Ink Mfg. Co., Ltd.) A mixture of 0.2 parts of foaming agent, 60 parts of water and 10 parts of isopropyl alcohol was ground with a paint conditioner, and ink base was prepared.
I got it. Next, the ink base was washed with a mixed solvent of water / isopropyl alcohol = 1/1 using a Zahn cup # 3.
Example 1 after adjusting to 16 seconds with (Rigosha)
10 parts of the aqueous dispersion of the polymer containing the compound having a carbodiimide group obtained in the above was added to obtain an aqueous printing ink.

Examples 7 to 10 and Comparative Examples 3 and 4 (Production of Water-Based Printing Inks) Water-based printing inks were obtained in the same manner as in Example 6, according to the formulations shown in Table 3.

Using the inks obtained in Examples 6 to 10 and Comparative Examples 3 and 4, a biaxially stretched polypropylene film (hereinafter referred to as OPP), a polyethylene terephthalate film (hereinafter referred to as PET), and a nylon film (hereinafter referred to as a gravure proofing machine). NY), and OPP, PET, and NY were evaluated for adhesion and NY was evaluated for boil resistance. Table 3 shows the results.

C) Adhesion The printed matter was subjected to a cellophane tape peeling test, and the adhesion was visually judged from the appearance of the printed film. ◎ Print film does not peel at all ○ 20% or less of print film peels △ 20% to 50% of print film peels × 50% or more of print film peels

D) Boil resistance After applying an isocyanate-based adhesive on the printed surface of the printed matter printed on the NY film, molten polyethylene is laminated on the adhesive layer by an extrusion laminating machine.
A laminated product was obtained. This laminated product was formed into a bag, a mixture of water / oil was put inside, and after sealing, the mixture was heated in hot water at 90 ° C. for 30 minutes, and the state of lamination was visually observed from the outside. ◎ There is no Lami floating at all. ○ Lami floating in pinhole shape. △ Delamination occurs in a streak shape. × Delamination occurs on the entire surface.

[0065]

[Table 3]

[0066]

As is clear from the examples and comparative examples, the aqueous dispersion of a polymer containing a compound having a carbodiimide group or the aqueous dispersion of a polymer having a carbodiimide group according to the present invention has no aggregates. Excellent storage stability. Further, the aqueous printing ink containing the aqueous dispersion of the present invention,
Excellent boil resistance.

 ────────────────────────────────────────────────── 54 Continued on the front page (54) [Title of the Invention] A method for producing an aqueous dispersion of a polymer containing a compound having a carbodiimide group, a method for producing an aqueous dispersion of a polymer having a carbodiimide group, and the respective methods Utilization of aqueous dispersion of polymer obtained by manufacturing method

Claims (13)

[Claims] 1. A compound (a1) having a carbodiimide group having no radically polymerizable unsaturated double bond and a radical polymerization having no functional group capable of reacting with a carbodiimide group, using a surfactant (c). Dispersing the mixture with the unsaturated monomer (b1) in water to obtain dispersed particles having an average particle diameter of 1.0 μm or less, and then polymerizing the radically polymerizable unsaturated monomer (b1). A method for producing an aqueous dispersion of a polymer containing the compound (a1) having a carbodiimide group. 2. Using a surfactant (c), a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond, and a radically polymerizable compound having a functional group capable of reacting with the carbodiimide group. The mixture with the unsaturated monomer (b2) is dispersed in water to obtain dispersed particles having an average particle size of 1.0 μm or less. Then, the radical polymerizable unsaturated monomer (b2) is polymerized and A carbodiimide group characterized by reacting a part of the carbodiimide group in the compound (a1) having a carbodiimide group with a functional group capable of reacting with the carbodiimide group in the radically polymerizable unsaturated monomer (b2). For producing an aqueous dispersion of a polymer having the same. 3. A compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond using a surfactant (c) and a radically polymerizable unsaturated compound having no functional group capable of reacting with the carbodiimide group. The mixture with the monomer (b1) is dispersed in water to obtain dispersed particles having an average particle diameter of 1.0 μm or less, and then the compound (a2) having a carbodiimide group and the radical polymerizable unsaturated monomer (B1) a method for producing an aqueous dispersion of a polymer having a carbodiimide group, which is copolymerized with (b1). 4. A compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond using a surfactant (c) and a radically polymerizable unsaturated monomer having a functional group capable of reacting with a carbodiimide group. The mixture with the monomer (b2) is dispersed in water to obtain dispersed particles having an average particle size of 1.0 μm or less, and then the compound (a2) having a carbodiimide group and the radical polymerizable unsaturated monomer ( b2) and reacting a part of the carbodiimide group in the compound (a2) having a carbodiimide group with a functional group capable of reacting with the carbodiimide group in the radically polymerizable unsaturated monomer (b2). A method for producing an aqueous dispersion of a polymer having a carbodiimide group, comprising the steps of: 5. The method for producing an aqueous dispersion of a polymer containing a compound having a carbodiimide group according to claim 1, wherein the surfactant (c) has a radically polymerizable unsaturated double bond. 6. The aqueous dispersion of a polymer having a carbodiimide group according to claim 2, wherein the surfactant (c) has a radically polymerizable unsaturated double bond. Method. 7. An aqueous dispersion of a polymer containing a compound having a carbodiimide group obtained by the production method according to claim 1. 8. An aqueous dispersion of a polymer having a carbodiimide group, obtained by the production method according to any one of claims 2 to 4. 9. The aqueous dispersion according to claim 7, wherein the average particle size of the polymer containing the compound having a carbodiimide group is 0.8 μm or less. 10. The aqueous dispersion according to claim 8, wherein the average particle size of the polymer having a carbodiimide group is 0.8 μm or less. 11. An aqueous printing ink comprising the aqueous dispersion according to claim 7. Description: 12. The aqueous printing ink according to claim 11, comprising an aqueous resin having a functional group capable of reacting with a carbodiimide group. 13. The aqueous printing ink according to claim 12, wherein the functional group capable of reacting with the carbodiimide group is —COOH.