JP2000119538A - Production of aqueous dispersion of composite resin having carbodiimide group and utilization of aqueous dispersion obtained by the same production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an aqueous dispersion of a cross-linking agent having carbodiimide group without using a special apparatus and to obtain a water- based printing ink which is a water-based printing ink excellent in preservation stability and capable of forming a printed layer excellent in boiling resistance by using the aqueous dispersion of the cross-linking agent having the carbodiimide group. SOLUTION: When polymerizing a mixture of a compound having carbodiimide group with a radically polymerizable unsaturated monomer in an aqueous medium, an aqueous resin having a functional group reactive with the carbodiimide group and functioning as a protective colloid is used to thereby react the carbodiimide group in the compound having the carbodiimide group with the functional group reactive with the carbodiimide group in the aqueous resin at the time of radical polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aqueous dispersion of an aqueous resin having a carbodiimide group, a method for producing an aqueous dispersion of a composite resin having a carbodiimide group, and various resins obtained by the respective production methods. The present invention relates to an aqueous printing ink comprising an aqueous dispersion of

[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 uses a special apparatus to prepare an aqueous dispersion of a crosslinking agent having excellent storage stability against water and a binder resin having -COOH or the like, despite having a carbodiimide group. A water-based printing ink having excellent storage stability, using an aqueous dispersion of a crosslinking agent having a carbodiimide group, having excellent adhesion to various substrates, It is an object of the present invention to provide a water-based printing ink capable of forming a printing layer excellent in water resistance.

[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. By using an aqueous resin having a functional group capable of reacting with a carbodiimide group when polymerizing a mixture with an unsaturated monomer in an aqueous medium, and functioning as a protective colloid, a carbodiimide is obtained during radical polymerization. A carbodiimide group in a compound having a group, and a functional group capable of reacting with the carbodiimide group in the aqueous resin, were reacted, and the aqueous dispersion was found to be extremely excellent in storage stability, thereby completing the present invention. . That is, the first invention relates to a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond and a radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group. The aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group
Is dispersed in an aqueous medium in the presence of (a), a part of the carbodiimide group in the compound (a1) having the carbodiimide group is polymerized while polymerizing the radically polymerizable unsaturated monomer (b1) and the aqueous resin (c1). Production of an aqueous dispersion containing an aqueous resin having a carbodiimide group and a polymer of the radically polymerizable unsaturated monomer (b1), characterized by reacting a functional group capable of reacting with the carbodiimide group in the above). Is the way.

The second invention relates to a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond.
And a radical polymerizable unsaturated monomer (b2) having a functional group capable of reacting with a carbodiimide group, and converting the mixture into an aqueous resin (c) having a functional group capable of reacting with a carbodiimide group.
In the presence of 1), a part of the carbodiimide group in the compound (a1) polymerized in an aqueous medium and having the carbodiimide group and the radical polymerizable unsaturated monomer (b2)
A method for producing an aqueous dispersion of a composite resin having a carbodiimide group, characterized by reacting a carbodiimide group with a functional group capable of reacting with a carbodiimide group in the aqueous resin (c1).

A third invention provides 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 converted into an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group.
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 aqueous resin (c1) in the presence of Which is a method for producing an aqueous dispersion of a composite resin having a carbodiimide group.

A fourth invention is a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond,
A mixture of a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with a carbodiimide group is prepared in an aqueous medium in the presence of an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group. A functional group capable of polymerizing and reacting with a part of the carbodiimide group in the compound having a carbodiimide group (a2) and the carbodiimide group in the radically polymerizable unsaturated monomer (b2) and the aqueous resin (c1) And a method for producing an aqueous dispersion of a composite resin having a carbodiimide group.

According to a fifth aspect of the present invention, the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group includes the aqueous resin having a carbodiimide group according to the first aspect, wherein the aqueous resin (c1) is a urethane resin. This is a method for producing an aqueous dispersion.

According to a sixth aspect, the carbodiimide group according to any one of the second to fourth aspects is characterized in that the aqueous resin (1c) having a functional group capable of reacting with the carbodiimide group is a urethane resin. This is a method for producing an aqueous dispersion of a composite resin having the same.

A seventh aspect of the present invention is the aqueous resin having a carbodiimide group according to the first or fifth aspect, wherein the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group has -COOH. And the like.

An eighth invention is directed to any one of the second to fourth and sixth inventions, wherein the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group has -COOH. This is a method for producing an aqueous dispersion of a composite resin having a carbodiimide group.

A ninth invention is an aqueous dispersion such as a polymer having a carbodiimide group obtained by the production method according to the first or fifth invention.

A tenth invention is an aqueous dispersion of a carbodiimide group-containing composite resin obtained by the production method according to any one of the second to fourth and sixth inventions.

An eleventh invention is directed to an aqueous printing ink comprising the aqueous dispersion according to the ninth or tenth invention and an aqueous resin (c2) having a functional group capable of reacting with a carbodiimide group. is there.

The twelfth invention is directed to the eleventh invention, wherein the functional group capable of reacting with the carbodiimide group in the aqueous resin (c2) having a functional group capable of reacting with the carbodiimide group is -COOH. Water-based printing ink.

[Detailed Description of the Invention] The first invention will be described. As described above, the first invention first comprises a compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond, and a radically polymerizable compound having no functional group capable of reacting with the carbodiimide group. A compound (a1) having a carbodiimide group is mixed with a saturated monomer (b1),
It is dissolved in the radical polymerizable unsaturated monomer (b1) as much as possible. Next, a mixture of the compound (a1) having a carbodiimide group and the radically polymerizable unsaturated monomer (b1) is emulsified in an aqueous medium using an aqueous resin having a functional group capable of reacting with a carbodiimide group as a protective colloid. Dispersing and polymerizing the radically polymerizable unsaturated monomer (b1). 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). Then, the radical polymerizable unsaturated monomer (b1) is polymerized while dispersing the mixture in an aqueous medium using an aqueous resin having a functional group capable of reacting with a carbodiimide group as a protective colloid. This makes it possible to obtain an aqueous dispersion with less aggregates. Further, using an aqueous resin having a functional group capable of reacting with a carbodiimide group as a protective colloid, after dispersing the mixture in an aqueous medium,
The radical polymerizable unsaturated monomer (b1) can also be polymerized.

The compound (a1) having a carbodiimide group used in the first invention has no radical 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 radical polymerizable unsaturated monomer (b1) is polymerized in the presence of the compound (a1) having a carbodiimide group, it has a functional group capable of reacting with a carbodiimide group in an aqueous resin used as a protective colloid, and a carbodiimide group. When the resin having a carbodiimide group generated by the reaction with a part of the carbodiimide group in the compound (a1) and the polymer of the radically polymerizable unsaturated monomer (b1) are in a state of being in a mixed state. Conceivable. And the resin having a carbodiimide group is a radical polymerizable unsaturated monomer (b
It is considered that the storage stability as a whole in an aqueous system could be improved, despite the presence of a carbodiimide group, because it was mixed with the polymer of 1).

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 in 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 carbodiimidation 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, and ( 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.

Aqueous resin (c) used as protective colloid
As 1), it is necessary to have a functional group capable of reacting with a carbodiimide group. Examples of the functional group capable of reacting with the carbodiimide group include a carboxyl group, a hydroxyl group, an amino group, and the like.These functional groups can react with the carbodiimide group, and do not dissolve the resin in the aqueous medium by neutralization. It is the part that has the function of dispersing. Therefore, it is preferable to react some of these functional groups with some of the carbodiimide groups in the compound (a1) having a carbodiimide group. Examples of the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group include a urethane resin, an acrylic resin, a polyester resin, and an epoxy resin having the above-described functional group. A urethane resin is preferable, and a carboxyl group is included. Urethane resins are preferred.
Since urethane resin is suitably used as a binder for aqueous printing inks as described later, use of a urethane resin as a protective colloid improves the compatibility between the obtained resin having a carbodiimide group and the binder for aqueous printing ink. This is preferable because the storage stability as an ink is improved. The aqueous resin (c1) as a protective colloid is based on 100 parts by weight of a mixture of the compound (a1) having a carbodiimide group and the radical polymerizable unsaturated monomer (b1).
The solid content is preferably 0.3 to 10 parts by weight.

When obtaining an aqueous dispersion such as a resin having a carbodiimide group, a general surfactant may be used in combination for the purpose of improving the stability during polymerization and the stability over time after polymerization. It is. As the surfactant, any of known nonionic, anionic, and cationic surfactants can be used, and nonionic and anionic surfactants are particularly preferable. These surfactants are used alone or in a mixture. The amount used is from 0.1% by weight to 1% by weight based on the unsaturated monomer.
It is preferably in the range of 0% by weight.

In the first invention, a known radical polymerization initiator can be used to polymerize the radically polymerizable unsaturated monomer (b1). Examples of the polymerization initiator include a water-soluble initiator and an oil-soluble initiator. Initiators can be used together. When using an oil-soluble initiator, it is preferable to dissolve it in the radical polymerizable unsaturated monomer (b1) in advance. On the other hand, when a water-soluble initiator is used, before forming an emulsion of the compound (a1) having a carbodiimide group and the radical polymerizable unsaturated monomer (b1) in the presence of the aqueous resin (c1). 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 at the time of polymerization is preferably 40 to 100 ° C, and when a redox initiator is used, 80 ° C or less is sufficient. Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile, benzoyl peroxide, isobutyryl peroxide, octanoyl peroxide, cumylperoxyoctate, and t-butylperoxy-2. -Ethylhexanoate, t-butylperoxyacetate, lauryl peroxide, di-t-butylperoxide, di-2
-Organic peroxides such as ethylhexylperoxyzine carbonate; and inorganic peroxide compounds such as potassium persulfate, ammonium persulfate and hydrogen peroxide. Organic or inorganic peroxide compounds can also be used as redox initiators in combination with reducing agents.
As the reducing agent used, L-ascorbic acid, L-
Sorbic acid, sodium metabisulfite, ferric sulfate, ferric chloride, Rongalite, and the like.

In the polymerization of the radical polymerizable unsaturated monomer (b1) in the first invention, the aqueous resin (c1)
And water, and the compound (a1) having a carbodiimide group and the radically polymerizable unsaturated monomer (b) are added thereto.
It is preferable to drop the mixture with 1). In the polymerization, a known chain transfer agent for the purpose of adjusting the molecular weight,
For example, octyl mercaptan, lauryl mercaptan,
It is also possible to use 2-mercaptoethanol, tercharddecyl mercaptan, thioglycolic acid and the like.

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 has a compound (a1) having a carbodiimide group and no radically polymerizable unsaturated double bond and a functional group capable of reacting with the carbodiimide group in the presence of the aqueous resin (c1). When the mixture with the radically polymerizable unsaturated monomer (b2) is polymerized in an aqueous medium, a part of the carbodiimide group in the compound having a carbodiimide group (a1) and the radically polymerizable unsaturated monomer ( b2) Medium and aqueous resin (c
The carbodiimide group in 1) is reacted with a functional group capable of reacting. The composite resin in the aqueous dispersion obtained by such a method is a radical polymerizable unsaturated monomer (b2). Is a composite resin having a carbodiimide group in which a polymer derived from the above, an aqueous resin (c1), and a compound (a1) having a carbodiimide group are complexly bonded.

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).

Compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond used in the second invention, aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group, polymerization initiator Examples of the method include those similar to those in the first invention, and the method of emulsifying the mixture, 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 an aqueous resin (c
In the presence of 1), a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond is reacted with a radically polymerizable unsaturated monomer (b2) having no functional group capable of reacting with the carbodiimide group. 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 aqueous resin (c1) when the mixture is polymerized in an aqueous medium. The composite resin in the aqueous dispersion obtained by such a method comprises a compound (a2) having a carbodiimide group and a radical polymerizable unsaturated monomer (b
1) A composite resin having a carbodiimide group in which a copolymer derived from the above, an aqueous resin (c1), and a compound (a2) having a carbodiimide group are intricately bonded.

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).

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 includes 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 aqueous resin (c1), the polymerization initiator, etc., are the first and the second. The same method as in the first invention can be exemplified, and the method for emulsifying the mixture, the polymerization method, and the like are the same as those in 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 provides an aqueous resin (c
In the presence of 1), a mixture of a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond and a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with the carbodiimide group Is reacted with a part of the carbodiimide group in the compound having a carbodiimide group (a2) and the carbodiimide group in the radically polymerizable unsaturated monomer (b2) and in the aqueous resin when is copolymerized in an aqueous medium. The composite resin in the aqueous dispersion obtained by such a method comprises a compound (a2) having a carbodiimide group and a radical polymerizable unsaturated monomer (b2). ) Is a composite resin having a carbodiimide group in which an aqueous resin (c1) and a compound (a2) having a carbodiimide group are complexly bonded.

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 aqueous resin (c1), the polymerization initiator, and the like can be the same as those in the second or third invention, respectively. The emulsification method of the mixture, the polymerization method, and the like are also the same as those in the first invention. is there.

The first to fourth inventions are summarized as follows.

[Table 1]

Next, the fifth to eighth inventions will be described. The fifth and sixth inventions relate to the case where a urethane resin is used as the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group having a protective colloid function in the first to fourth inventions. An eighth invention is directed to the first to sixth aspects.
In the above invention, the aqueous resin having —COOH is used as the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group having a protective colloid function.
The ninth to tenth inventions are aqueous dispersions of a resin having a carbodiimide group obtained by the above-mentioned first to sixth production methods, or a composite having a carbodiimide group.

Next, the eleventh to twelfth inventions will be described. An eleventh invention is an aqueous resin (c2) having a functional group capable of reacting with the aqueous dispersion according to any one of the ninth and tenth inventions and a carbodiimide group as a binder for ink.
And a water-based printing ink. Although the aqueous printing ink is aqueous, a functional group capable of reacting with the carbodiimide group in the aqueous resin (c2) in the printing layer is a crosslinking agent, that is, a carbodiimide group in the aqueous dispersion. By reacting with and cross-linking with the carbodiimide group in the composite resin, a printed material having excellent water resistance, boiling resistance, and retort resistance can be provided.

An aqueous resin (c2) in an aqueous printing ink,
The mixing ratio with the aqueous dispersion of any one of the ninth and tenth inventions is not particularly limited, but the carbodiimide in the crosslinking agent is equivalent to one equivalent of the functional group (number) capable of reacting with the carbodiimide group in the aqueous resin. It is preferable to mix the groups (number) so as to be in the range of 0.1 to 5 equivalents. Aqueous resin (c2)
Examples of the functional group capable of reacting with the carbodiimide group therein include an active hydrogen group such as a carboxyl group, a hydroxyl group and an amino group, and a carboxyl group is preferred. Examples of the aqueous resin (c2) used in the first to twelfth inventions include urethane resins, polyester resins, and polymers of ethylenically unsaturated monomers each having the above functional group, and among them, urethane resins are preferable. Particularly, a urethane resin having a carboxyl group is preferable from the viewpoint of physical properties.

Examples of the pigments used in the aqueous printing inks of the first to twelfth 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 according to the eleventh to twelfth 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).

[0047]

EXAMPLES In the following Production Examples and Examples, "parts" means parts by weight unless otherwise specified.

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 reaction was carried out for 10 hours to obtain tetramethylxylylenecarbodiimide (C) having a radically polymerizable unsaturated group at a 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 63 parts of isophorone diisocyanate, 180 parts of polytetramethylene glycol having a number average molecular weight of about 2,000 and a hydroxyl value of 56 (mg KOH /), about 2000 parts of a number average molecular weight of 56 (mg) Add 29.4 parts of polyethylene glycol of KOH /), 28.5 parts of dimethylolbutanoic acid, 0.1 part of dibutyltin dilaurate, and 600 parts of methyl ethyl ketone (MEK), raise the temperature to 80 ° C, and react for 4 hours to obtain a solution of a urethane resin having -COOH. I got The urethane resin solution was cooled to 30 ° C., and 15 parts of ammonia water and 660 of distilled water were used.
After the addition of MEK, MEK was removed to obtain an aqueous dispersion of urethane resin having a solid content of about 33%.

Production Example 5 (Synthesis of aqueous dispersion of urethane resin having no carboxyl group) 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 81 parts of isophorone diisocyanate, a number average molecular weight of about 2,000, 30 parts of polypropylene glycol having a hydroxyl value of 56 (mg KOH /), a number average molecular weight of about 1,000, and a hydroxyl value of 111 (mg KOH / ), 189.3 parts of polyethylene glycol, 0.1 part of dibutyltin dilaurate and 600 parts of methyl ethyl ketone (MEK) were added, and the mixture was heated to 80 ° C and reacted for 4 hours to obtain a solution of a urethane resin having no -COOH. The urethane resin solution was cooled to 30 ° C., and 15 parts of ammonia water and 66 parts of distilled water were used.
After adding 0 parts, MEK was removed to obtain an aqueous dispersion of a urethane resin having a solid content of about 33%.

Production Example 6 (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) 700 parts was 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 ammonia water, 800 parts of distilled water was added, and then IPA was removed to obtain an aqueous acrylic resin dispersion having a solid content of about 30%. .

Example 1 A mixture of 60 parts of tetramethylxylylenecarbodiimide obtained in Production Example 1, 20 parts of methyl methacrylate (MMA), 40 parts of butyl acrylate (BA), and 3 parts of azobisisobutyronitrile was added to a dropping funnel. Prepare. A four-necked 100 equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer and a thermometer.
100 parts of water and 400 parts of the aqueous urethane resin obtained in Production Example 4 were charged into a 0 ml flask, stirring was started, and the temperature was raised to 80 ° C. in a nitrogen stream. The mixture was added dropwise over 2 hours while maintaining the internal temperature at 80 ° C. After the addition, 8
The reaction was performed at 0 ° C. for 2 hours to obtain an aqueous dispersion (A) of a resin having a carbodiimide group and a copolymer of MMA and BA.

Examples 2 to 5, Comparative Examples 1 and 2 An aqueous dispersion of a resin having a carbodiimide group and a copolymer of MMA, BA, etc. B) to (D), (R-1),
An aqueous dispersion (E) of (R-2) and a composite resin having a carbodiimide group was 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 were free of aggregates and stable in storage. 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.

[0057]

[Table 2]

Example 6 (Production of Water-based Printing Ink) 100 parts of the aqueous urethane resin aqueous dispersion obtained in Production Example 4, 40 parts of a phthalocyanine-based blue pigment (Lionol Blue KLH manufactured by Toyo Ink Mfg. Co., Ltd.), defoaming A mixture of 0.2 part of the agent, 60 parts of water, and 10 parts of isopropyl alcohol is ground with a paint conditioner and the ink base is 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.
After adjusting the time to 16 seconds (manufactured by Rigosha), the resin having a carbodiimide group obtained in Example 1, MMA and BA
10 parts of an aqueous dispersion of a mixture with a copolymer of
An aqueous printing ink was obtained.

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, using a gravure calibrator, a biaxially stretched polypropylene film (hereinafter referred to as OPP), a polyethylene terephthalate film (hereinafter referred to as PET), and a nylon film (referred to below). 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 printing surface of the printed matter printed on the NY film, a 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.

[0063]

[Table 3]

[0064]

As is clear from the Examples and Comparative Examples, the aqueous dispersion of the present invention such as a resin having a carbodiimide group or the aqueous dispersion of a composite resin having a carbodiimide group is free from agglomerates and has good storage stability. Excellent. Furthermore, the aqueous printing ink containing the aqueous dispersion of the present invention has excellent boil resistance.

Claims (12)

[Claims] 1. A compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond and a radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group. The mixture is dispersed in an aqueous medium in the presence of an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group to polymerize the radically polymerizable unsaturated monomer (b1) and to convert the carbodiimide group. 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 aqueous resin (c1). A method for producing an aqueous dispersion containing a polymer of a saturated monomer (b1). 2. A compound (a1) having a carbodiimide group and having no radically polymerizable unsaturated double bond, and a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with the carbodiimide group. The mixture is polymerized in an aqueous medium in the presence of an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group, and a part of the carbodiimide group in the compound (a1) having a carbodiimide group and the radical polymerization A method for producing an aqueous dispersion of a composite resin having a carbodiimide group, comprising reacting a functional group capable of reacting with a carbodiimide group in the unsaturated monomer (b2) and the aqueous resin (c1). 3. A mixture of a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond and a radically polymerizable unsaturated monomer (b1) having no functional group capable of reacting with the carbodiimide group. In the presence of an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group,
A carbodiimide which is polymerized in an aqueous medium and reacts 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 aqueous resin (c1). A method for producing an aqueous dispersion of a composite resin having a group. 4. A mixture of a compound (a2) having a carbodiimide group and a radically polymerizable unsaturated double bond, and a radically polymerizable unsaturated monomer (b2) having a functional group capable of reacting with a carbodiimide group, Polymerization in an aqueous medium in the presence of an aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group, and a part of the carbodiimide group in the compound (a2) having a carbodiimide group and the radical polymerizable unsaturated compound A method for producing an aqueous dispersion of a carbodiimide group-containing composite resin, comprising reacting a functional group capable of reacting with a carbodiimide group in the monomer (b2) and the aqueous resin (c1). 5. The production of an aqueous dispersion containing an aqueous resin having a carbodiimide group according to claim 1, wherein the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group is a urethane resin. Method. 6. The aqueous dispersion of a composite resin having a carbodiimide group according to claim 2, wherein the aqueous resin (1c) having a functional group capable of reacting with a carbodiimide group is a urethane resin. Manufacturing method. 7. The aqueous dispersion containing an aqueous resin having a carbodiimide group according to claim 1 or 5, wherein the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group has -COOH. Manufacturing method. 8. The composite resin having a carbodiimide group according to claim 2, wherein the aqueous resin (c1) having a functional group capable of reacting with a carbodiimide group has —COOH. A method for producing an aqueous dispersion. 9. An aqueous dispersion of a polymer having a carbodiimide group obtained by the production method according to claim 1 or 5. 10. An aqueous dispersion of a carbodiimide group-containing composite resin obtained by the production method according to claim 2. Description: 11. An aqueous printing ink comprising the aqueous dispersion according to claim 9 and an aqueous resin (c2) having a functional group capable of reacting with a carbodiimide group. 12. The aqueous printing ink according to claim 11, wherein the functional group capable of reacting with the carbodiimide group in the aqueous resin (c2) having a functional group capable of reacting with the carbodiimide group is —COOH.