JPS60217271A - Cationic aqueous pigment dispersion - Google Patents

Abstract

PURPOSE:The titled dispersion for covering steel plates, etc., consisting of a water-soluble copolymer consisting of a fatty acid-modified (meth)acrylic monomer, aminoalkyl (meth)acrylate, etc. in a specific proportion, a pigment and an aqueous medium, and having improved easy dispersibility and dispersion stability. CONSTITUTION:A cationic aqueous pigment dispersion obtained by using a water-soluble copolymer prepared by copolymerizing (A) 3-98pts.wt. (meth)acrylic monomer modified with a fat or oil fatty acid of synthetic saturated fatty acid, e.g. neopentanoic acid, with (B) 1-97pts.wt. aminoalkyl (meth)acrylate or aminoalkyl (meth)acrylamide based monomer, (C) if necessary 0-96pts.wt. alpha,beta-ethylenically unsaturated nitrogen-containing monomer other than the component (B) and (D) 0-91pts.wt. alpha,beta-ethylenically unsaturated monomer other than the components (A), (B) and (C), and converting, the amino groups in the resultant copolymer into quaternary ammonium, a dispersing agent, pigment and aqueous medium together.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cationic aqueous pigment dispersion that uses a novel dispersant and has excellent dispersibility and dispersion stability.

Conventionally, in water-based paints such as emulsion paints and water-soluble resin paints containing pigments, the coloring effect on the painted surface decreases due to the difficulty of dispersing the pigments during manufacturing and the aggregation and sedimentation of the pigments during storage.
It is well known that undesirable phenomena such as flooding, floating, and loss of gloss occur. For this reason, generally, an aqueous pigment dispersion liquid in which pigments are dispersed with a dispersant is prepared in advance, and this dispersion is mixed and dispersed in a colored aqueous paint to prepare an aqueous paint.

In conventional aqueous pigment dispersions, low molecular weight compounds such as surfactants are mainly used as dispersants. The following negative effects are unavoidable, and in recent years oligomers or polymers with medium molecular weight have been used as dispersants to suppress the deterioration of coating performance.

However, due to technical reasons, when an oligomer or polymer is used as a dispersant, the amount used is large compared to a low-molecular-weight interfacial elongating agent, and the resulting aqueous pigment dispersion is not suitable for use in water-based paints. There are disadvantages such as being limited by the type of binder that can be used. This goes against the rationalization of paint production, and there is therefore a strong demand for the development of an aqueous pigment dispersion that can be commonly used in various water-based paints.

Therefore, the present inventors have found that pigments can be easily dispersed in small amounts and are compatible with various aqueous resins, especially cationic aqueous resins.
In addition, as a result of intensive research aimed at developing an ideal gas dispersant that is itself a polymer and does not cause any deterioration in the film performance of water-based paints, the present invention was completed.

Thus, according to the present invention, in an aqueous pigment dispersion consisting of a pigment, a dispersant and an aqueous medium, - the dispersant is (l) a (meth)acrylic monomer modified with an oil or fat fatty acid or a synthetic saturated fatty acid (hereinafter referred to as (hereinafter referred to as "fatty acid-modified (meth)acrylic monomer") 3 to 98 parts by weight (B) Aminoalkyl (meth)acrylate or aminoalkyl (meth)acrylamide monomer (hereinafter referred to as "fatty acid-modified (meth)acrylic monomer") Aminoalkyl (meth)acrylic monomer”
) 1 to 97 parts by weight (C) 0 to 96 parts by weight of α, β-ethylenic, unsaturated nitrogen-containing monomers other than the above (B) and ゛ □ ゛ (D)-h CA), CB)・, α other than (,C).

A water-insoluble copolymer obtained by copolymerizing 0 to 91 parts by weight of a β-ethylenically unsaturated monomer and converting the amino groups present in the resulting copolymer into quaternary ammonium. A cationic aqueous pigment dispersion is provided.

・The above polymer used as a dispersant for the cationic aqueous pigment dispersion of the present invention has a relatively lipophilic long side chain separated from a main chain containing a hydrophilic nitrogen-containing monomer. Because it has a bonded structure, it has extremely high pigment dispersion ability. ``Furthermore, since the polymer has an extremely excellent ability to adsorb conventional pigments to nitrogen-containing monomer units, it strongly adsorbs to pigment particles and provides a paint with excellent storage chamber 5 consistency.Also. Since the polymer is basic, it has excellent properties such as corrosion resistance.
A good colored coating film can be provided.

The dispersant used in the cationic aqueous pigment dispersion of the present invention will be explained in more detail below.

The fatty acid-modified (meth)acrylic monomer (A) used in the present invention is a (meth)acrylic monomer as described below, and an oil such as a drying oil fatty acid, a semi-drying oil fatty acid, a non-drying oil fatty acid, etc. It is a monomer produced by introducing a fatty acid or a synthetic saturated fatty acid by the method described below.

Typical fat and oil fatty acids that can be used in the present invention include, for example, safflower oil fatty acid, pomani oil fatty acid, soybean oil fatty acid, goya oil fatty acid, □poppy seed oil fatty acid, corn cocoon oil fatty acid, and tall oil fatty acid. Drying and semi-drying oil fatty acids such as , castor oil fatty acids, cottonseed oil fatty acids, walnut oil fatty acids, rubberseed oil fatty acids, tung oil fatty acids, olive oil fatty acids, dehydrated castor oil fatty acids, hygienic fatty acids; and coconut oil fatty acids, olive oil fatty acids, castor oil fatty acids Examples include non-drying oil fatty acids such as oil fatty acids, hydrogenated castor oil fatty acids, and palm oil fatty acids, and these fatty acids can be used alone or in a mixture of two or more types.

In addition, the synthetic saturated fatty acids used in the present invention can be obtained from natural fats and oils or fatty acids or petroleum raw materials using the ozone oxidation method, the Baraquin liquid phase air oxidation method, the Okin method, the Koch
It is a linear or branched saturated aliphatic carboxylic acid having 4 to 24 carbon atoms, preferably 5 to 18 carbon atoms, which is artificially introduced by a method such as the method, and is a typical synthetic saturated fatty acid. Examples include neopentanoic acid, 2-ethylbutyric acid,
heptanoic acid, 2-ethylhexanoic acid, isooctanoic acid,
Examples include nonanoic acid, isononanoic acid, decanoic acid, indecanoic acid, neodecanoic acid, indoridecanoic acid, impalmitic acid, isostearic acid, and the like.

The amount of the fatty acid used can vary widely depending on the drying properties and film performance desired for the aqueous pigment dispersion provided by the present invention, but is generally based on the weight of the resulting polymer. It is advantageous to use amounts falling within the range from 5 to 65% by weight, preferably from 10 to 60% by weight.

In addition, in the present invention, among the above-mentioned fatty acids, drying oil fatty acids and semi-drying oil fatty acids having an iodine value of about 100 or more are suitable because they can impart crosslinking drying properties to the resulting dispersant at room temperature.

The (meth)acrylic monomer into which such a fatty acid is introduced is an ester of acrylic acid or methacrylic acid containing a functional group capable of reacting with the carboxyl group of the fatty acid, such as an epoxy group or a hydroxyl group, in the ester residue portion. can be exemplified.

However, fatty acid-modified (meth)acrylic monomer (,4
One type of (meth)acrylic monomer into which the above-mentioned fatty acids are introduced is "acrylic acid ester or methacrylic acid ester having an epoxy group" (hereinafter referred to as "epoxy-containing ester"). (sometimes abbreviated as "(meth)acrylic acid ester"), and examples of this type of ester include those containing a glycityl group in the ester residue of acrylic acid or methacrylic acid, especially those containing glycityl groups, Acrylates and glycidyl methacrylates are preferred. Such polypoxy-containing (meth)
) Preparation of fatty acid-modified acrylic monomer (, 4) using acrylic acid ester is described in 1. According to common law, appropriate −〇
- in the presence or absence of an inert solvent, usually in the absence of a solvent,
This can be carried out by reacting the aforementioned fatty acid with an epoxy-containing (meth)acrylic ester. The reaction is generally carried out at a temperature of from about 60°C to about 220°C, preferably from about 120°C to about 220°C.
It can be carried out at a temperature of about 170°C, and the reaction time is generally about 0.5 to about 40 hours, preferably about 3 to about 1 hour.
It is 0 hours.

The epoxy-containing (meth)acrylic ester is usually
It is advantageous to use a proportion of 0.7 to 1.5 mol, preferably 0.8 to 1.2 mol, per mol of said fatty acid.

In addition, as an inert solvent that may be used as necessary,
Water-immiscible organic solvents that can be refluxed at temperatures below 220°C are preferred, such as aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as heptane, hexane, and octane. "Elementary... 10-" is mentioned.

Further, in accordance with the above reaction, a polymerization inhibitor such as noihydroquinone, methoxyphenol, tart-butylcatechol, benzoquinone, etc. is added to the reaction system as necessary, and epoxy-containing (meth)acrylic ester and/or It is advantageous to suppress the polymerization of the fatty acid-modified (meth)acrylic esters formed.

In the above reaction, esterification accompanied by cleavage of the oxirane ring occurred between the oxirane ring (epoxy group) of the epoxy-containing (meth)acrylic acid ester and the xyl group of the fatty acid, resulting in modification with the fatty acid (meth). An acrylic ester is obtained.

In addition, another type of fatty acid-modified (meth)acrylic monomer <A) is reacted with the above fatty acids to produce (A)
The meth)acrylic monomer includes "acrylic ester or methacrylic ester containing a hydroxyl group" [hereinafter, this may be abbreviated as "(meth)acrylic ester containing a hydroxyl group"], and this type The ester has one hydroxyl group in the ester residue of acrylic acid or methacrylic acid, and has 2 to 2 hydroxyl groups in the ester residue.
Those containing 4, preferably 2 to 8 carbon atoms are included, especially those of the following formula (I) or (IT)0 CH,=C-COO+CnH,, 10og (I)R3 CH,=C-C00 -fC fortune O←→C190-1,H(
In each of the above formulas, R1 represents a hydrogen atom or a methyl group,
n is an integer of 2 to 8, p and q are each integers of 0 to 8, provided that the sum of p and q is 1 to 8; is suitable. - Particularly suitable hydroxyl group-containing (meth)acrylic acid esters in the present invention include hydroxyalkyl acrylates and hydroxyalkyl methacrylates represented by the above formula (I), especially 2-hydroxyethyl acrylate, 2-
They are hydroxyethyl methacrylate, 2-hydroxyalkyl acrylate and 2-hydroxypropyl methacrylate.

The latter type of fatty acid-modified (meth)acrylic monomers (
A) can usually be prepared by reacting the fatty acid with the hydroxyl group-containing (meth)acrylic ester in an appropriate inert solvent in the presence of an esterification catalyst. The reaction is generally carried out at a temperature of about 100 to about 18.0°C.
It is preferably carried out under heating at a temperature of about 120 to about 160°C, and the reaction time is generally about 0.5 to about 9 hours, usually about 1 hour.
~about 6 hours.

13- The hydroxyl group-containing (meth)acrylic acid ester can usually be used at a ratio of 90.5 to 1.9 mol per mol of the fatty acid, preferably J) per mol of the fatty acid.
It is advantageous to use a proportion of 1.5 mol of O-'.

Examples of the esterification catalyst used in the above reaction include sulfuric acid, aluminum sulfate, potassium hydrogen sulfate, p-toluenesulfonic acid, hydrochloric acid, methyl sulfate, and phosphoric acid. About 0.001 to about 20% by weight, preferably about 0.05% by weight of the total amount of the fatty acid and the hydroxyl group-containing (meth)acrylic ester
~1.0% by weight.

In addition, as an inert solvent used as necessary, 1
Water-immiscible organic solvents that reflux at a temperature of 80° C. or lower are preferred, such as aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hep-14-tane, hexane and octane. I get kicked.

Furthermore, in the above reaction, a polymerization inhibitor, such as hydroquinone, methoxyphenol, tert-butylcatechol, benzoquinone, etc., is added to the reaction system as necessary, and a hydroxyl group-containing (meth)acrylic ester and/or a polymerization inhibitor is added to the reaction system. It is advantageous to suppress the polymerization of fatty acid-modified (meth)acrylic esters.

In the above reaction, esterification occurs between the hydroxyl group of the hydroxyl group-containing (meth)acrylic ester and the carboxyl group of the fatty acid, and a fatty acid-modified (meth)acrylic ester is obtained.

As yet another method for preparing the fatty acid-modified (meth)acrylic monomer (4), in addition to the method described above, glycidyl esters of the fat and oil fatty acids (for example, 1 Bremmer DFA manufactured by NOF Corporation) can be used. ) can be subjected to an esterification reaction with acrylic acid or methacrylic acid as described above.

The aminoalkyl (meth)acrylic monomer (B) used in the present invention includes those containing a substituted amino group in the ester moiety of (meth)acrylic acid ester and (meth)
Those containing a substituted amine group in the amide moiety of acrylic acid are included, and in particular, the following formula (e) or ■ i In each of the above formulas, R1 represents a lower alkyl group, and R8 and R4 each independently represent a hydrogen atom or a lower alkyl group. Representing an alkyl group, Ro and n have the meanings given above, those of the following are suitable. The term "lower" used herein means that the group to which this term refers has 6 or less carbon atoms, preferably 4 or less carbon atoms.

Therefore, as specific examples of such aminoalkyl (meth)acrylic monomers, examples of the above formula 4 include N,
N-dimethylaminoethyl (meth)acrylate, N,
N-dimethylaminobutyl (meth)acrylate, N-
t-Butylaminoethyl (meth)acrylate, N, N
-tumethylaminopropyl (meth)acrylate, N,
N-dimethylaminobutyl (meth)acrylate, N-
including butylaminoethyl (meth)acrylate-FXN-butylaminoethyl (meth)acrylate,
Further, in the example shown by the above formula 4, N.

N-dimethylaminoethyl (ivy) acrylamide 17
- Do, N, N-trimethylaminopropyl (meth)acrylic compound, etc., each of which may be used alone or in combination with two
Seven or more species may be used in combination. Among the above-mentioned aminoalkyl (meth)acrylic monomers, aminoalkyl (meth)acrylates of formula (e) are preferred, and N,N-di-lower alkylaminoalkyl (meth)acrylates are particularly suitable. It is.

Next, α other than the above CB used in the present invention,
β-Ethiethyl unsaturated nitrogen-containing monomer <C> is 1
The molecule contains a monomer containing one or more (usually up to 4) basic nitrogen atoms and one ethylenically unsaturated bond, and typically has a nitrogen-containing heterocycle. Examples include unsaturated monomers and nitrogen-containing derivatives of (meth)acrylic acid. These monomers will be explained in more detail below.

[1] As the unsaturated monomer having a nitrogen-containing heterocycle,
Included are monomers in which a mono- or polycyclic heterocycle containing 1 to 3, preferably 1 or 2 ring nitrogen atoms is bonded to a vinyl group, and particularly the monomers shown below can be mentioned.

(I) Vinylpyrrolidones: Examples include 1-vinyl-2-pyrrolidone, 1-vinyl-3
- such as pyrrolidone.

(n) Vinylpyridines: For example, 2-vinylpyridine, 4-vinylpyridine, 5
-Methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine, etc.

(2) Vinylimidazoles: For example, 1-vinylimidazole, 1-vinyl-2-methylimidazole, etc.

■ Vinyl carbazole = 2 For example, N-vinylcal 9sol.

M Vinylquinolines: For example, 2-vinylquinoline.

■ Vinylpipericins: For example, 3-vinylpiperinone, N-methyl-3-vinylpiperinone, etc.

M. Vinyl lactams: For example, vinyl caprolactam.

(2) Others: N-(meth)acryloylmorpholine represented by the formula (1 has the above meaning), N-(meth)acryloburpyrrolisone represented by the formula (having the formula), etc.

Among the above-mentioned vinyl monomers having a nitrogen-containing heterocycle, preferred are vinylpyrrolidones, vinylimidazole, and vinylcarbazole sb, and among them, those in which the ring nitrogen atom is tertiary are preferred. .

[2] Nitrogen-containing derivatives of (meth)acrylic acid include amides of (meth)acrylic acid, particularly in the following formula M1, where Rs represents a hydrogen atom or lower alkyl, and R6
represents a hydrogen atom, a lower alkyl group, a hydroxy lower alkyl group, or a lower alkoxy lower alkyl group; 1. R1
Suitable are (meth)acrylamides represented by 21-, in which 21- has the abovementioned meaning. ′
Thus, examples of (meth)acrylated amides of formula M include (methaneacrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-butyl(meth)acrylamide, N,N- Dimethyl(meth)acrylamide, N,N-diprotyl(meth)acrylamide, N.

Included are N-sopropyl (meth)acrylamide, N, fi tyrol (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, and the like.

Among these (meth)acrylamides, those in which the nitrogen atoms present are tertiary are optimal, and then
Those that have been graded are preferably used.

The above-mentioned α, β-ethyethyl unsaturated nitrogen-containing monomers can be used alone or in combination of two or more.

Furthermore, α other than CA), CB>, and <C) above.

There are no particular restrictions on the β-ethylenically unsaturated monomer CD), and it can be selected from a wide range depending on the desired performance of the dispersant of the present invention. Representative examples of such unsaturated monomers are as follows.

(a) Esters of acrylic or methacrylic acid, such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, methacrylate. ethyl acid, propyl methacrylate, isozotetravir methacrylate,
Cl-H alkyl esters of acrylic acid or methacrylic acid such as butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate, etc. ethyl, methoxyethyl methacrylate,
't-ta alkoxyalkyl esters of acrylic acid or methacrylic acid such as ethoxybutyl acrylate and ethoxybutyl methacrylate;
alkenyl ester-rich human xyethyl acrylate,
C1-, hydroxyalkyl esters of acrylic acid or methacrylic acid such as hydroxyethyl methacrylate, hydroxyglobyl acrylate, and hydroxypropyl methacrylate; C,8, alkenyloxy of acrylic acid or methacrylic acid such as allyloxyethyl acrylate and allyloxydimethacrylate Alkyl ester; 2
- CS-*Carpoxyalkyl ester of acrylic acid or methacrylic acid, such as carpoxy ≠ acrylate.

(b) Vinyl aromatic compounds: for example, styrene, α=
Methylstyrene, vinyltoluene, p-chlorostyrene. '゛(C) Polyolefin compounds: examples include putazoene, isoprene, and chloroprene.゛ -(Ka α,β-ethyethyl unsaturated carboxylic acid; for example, acrylic acid, acrylic acid, maleic acid, itaconic acid, etc.

(e) Others: acrylonitrile, methacrylaterile, methyl isopropenyl ketone, bitel acetate, Paeonoku monomer (Shell Chemical FF product), vinyl teropione i
To, biralgi barate, etc. , .

The unsaturated monomers may be selected as appropriate depending on the physical properties desired for the water droplet liquid, and may be used alone or in combination of two or more. You can use stones.

According to the present invention, the above fatty acid-modified (meth)acrylic monomer (A), aminoalkyl (meth)acrylic monomer (''), and lβ-ethylenically unsaturated nitrogen-containing monomer body(
C) and the unsaturated monomer (D) are copolymerized with each other. The copolymerization can be carried out according to a method known per se for producing octyl (meth)acrylate, for example, using a solution polymerization method, an emulsion polymerization method, a suspension lid method, etc.

□ The blending ratio of the above four components in copolymerization can be changed depending on the desired performance as a dispersant, but it is generally appropriate to mix them in the following ratios.

(i) Fatty acid modified (meth)ac IJ A/based monomer (
, ('): 3 to 8 parts, 5 to 90 parts by weight, more preferably 15 to 5 parts by weight, in terms of drying properties and film performance of the tFj-i coating film, more preferably 15 to 5 parts by weight, ゛ - ” 26- (2) Aminoalkyl (meth)acrylic monomer (73
): 1 to 97 parts by weight, preferably 3 to 90 parts by weight, more preferably 5 to 80 parts by weight from the viewpoint of pigment dispersion, (3) α, β-Ethiethyl unsaturated nitrogen-containing monomer (('
): 0 to 96 parts by weight, preferably 5 to 90 parts by weight in terms of water solubility and coating performance, more preferably 10 to 75 parts by weight, (4) Other than the above (, 4), CB), and (C) Unsaturated monomer (D): o to 91 parts by weight, preferably 2 to 83 parts by weight in terms of coating film performance, more preferably 5 to 75 parts by weight, The above copolymerization reaction is advantageously carried out in solution. It is preferable to carry out the reaction according to a polymerization method, in which the above four components are mixed in a suitable manually activated solvent in the presence of a polymerization catalyst at a reaction temperature of usually about 0 to about 180°C, preferably about 40 to about 170°C, and about 1 ~
This can be carried out by continuing the reaction for about 20 hours, preferably about 6 to about 10 hours.

As the solvent used, it is desirable to use a solvent that can dissolve the copolymer to be produced and is miscible with water. Particularly preferred are those that can be used as they are without being removed when obtaining a cationic aqueous pigment dispersion. Examples of such solvents include 2HO-CH.

CH, -0R1 (wherein, R, represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms), such as ethylene glycol, ptylacetate, ethyl cellosolve, etc. HOCH, -CH-0
R, r (However, R1 is the same CH as above.

[Has a meaning]'s tetrapyrene glycol/' series? f medium, such as propylene glycol monomethyl ether, etc.
Formula HO-CH, CH, -QC Horse C Horse-0R1 [However,
R1 has the same meaning as above], such as diethylene glycol 1. Methylcarpitol, butylcarpitol, etc.; Formula R, 0-CH, C
Ht-OR, C, but B and R.

each represents an alkyl group having 1 to 3 carbon atoms]
glyme-based solvents such as ethylene glycol dimethyl ether; formula R80-CH,CH.

ocuma-CumaOR9 [wherein R3 and R9 have the same meanings as above] soge2im-based solvents, such as zoethylene glycol somethyl ether; formula R1゜0-
CH, CH, 0CO-CH, (wherein R3° represents a hydrogen atom or CH, or C, H) cellosolve acetate solvents, such as ethylene glycol monoacetate, methyl cellosolve acetate, etc.
, OH [wherein R1 represents an alkyl group having 1 to 4 carbon atoms] insoluble in alcohol, such as ethanol, propatool, butanol; and diacetone alcohol, dioxane, tetrahydrofuran, acetone , dimethylformamide, 3-methoxy-3-methyl-butanol, etc. can be used.

However, since water-immiscible inert solvents can also be used, such water-immiscible solvents have a boiling point that allows them to be easily removed by distillation at normal or reduced pressure after the polymerization reaction is completed. Preferably, the temperature is 250°C or less. Such solvents include, for example, aromatic hydrocarbons represented by the formula [representing an alkyl group having 1 to 4 atoms] or [representing an alkyl group having 1 to 4 atoms], such as toluene, xylene, etc.; R11-CO0-R,, [where R1゜30- represents an alkyl group having 1 to 6 carbon atoms, and R111
represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cyclohexyl group], such as acetic acid, ethyl formate, butyl acetate,
Rty Rts C-OC such as cyclohexyl acetate
However, R8 and R18 each have 1 to 8 carbon atoms.
[representing an alkyl group] methyl ethyl ketone, cyclohexanone, etc.; formula Rsy'-Rta (however,
R1? and RH have the same meanings as above], ethyl ether, hexyl ether, and hexyl ether are represented by the formula R1゜OH (wherein, R8 represents an alkyl group having 5 to 11 carbon atoms). Examples include alcohols represented by, for example, hexanol.

These solvents contain 15 to 9 of the total weight of the four copolymer components.
It can be used in a range of 0% by weight.

In addition, examples of polymerization catalysts include azo compounds, oxide compounds, sulfides, sulfines,
Radical initiators that can be used in conventional radical polymerizations are used, such as sulfinic acids, soazo compounds, nitroso compounds, redox systems, and ionizing radiation.

In the present invention, a substantially satisfactory aqueous pigment dispersion can be obtained even if the molecular weight of the copolymer to be produced changes, but if the molecular weight is too low, there is a risk of deterioration of the physical properties of the water-based paint to be colored. be.

Moreover, if the molecular weight is too high, the viscosity will increase, and if the viscosity is lowered, the concentration of the copolymer will decrease and the dispersibility of the pigment will decrease. Therefore, the above copolymerization reaction generally results in a number average molecular weight of the resulting copolymer of about 500 to 150,000, preferably about i, o o o to about i o o, o o o.
It is advantageous to carry out this process until it is within the range of .

Additionally, the copolymers thus obtained generally have at least 0
．． It may have an amino group equivalent weight of 0.2 meq/2 copolymer, preferably 0.2 meq/V copolymer.

For example, when the copolymer used as a dispersant in the present invention is converted into quaternary ammonium, the following 1,2-
This can be carried out by reacting an epoxy compound in the presence of acid and/or water to convert secondary or tertiary amino groups in the copolymer into quaternary ammonium.

1, 2 that can be used for quaternary ammonium formation of cough copolymers
-Epoxy compounds include, for example, the following formula (g)R□, where R1 has the above meaning, and R8゜ is a hydrogen atom, an alkyl group, a cycloalkyl group, 33- -CH, -0-R□, - CHl-0-C-R, or 1 0 ・represents a substituted or unsubstituted phenyl group, where R□
is a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, or a substituted tui or unsubstituted phenyl group, and those represented by □ are suitable. Alkyl and cycloalkyl groups which may be represented by R6° and/or Rtt in the formula can generally have 1 to 18, preferably 1 to 8 carbon atoms, and alkenyl groups preferably have 2 to 6 carbon atoms. carbon atoms. Furthermore, examples of substituents on the phenyl group include lower alkyl groups and lower alkoxy groups.

Representative examples of such 1,2-engine, tv-47 compounds include □
Ethylene oxide P1 zorogylene oxide, R2-butylene oxide, l,2-pentylene oxide, 1,2-octylene oxide, styrene oxide, glycidol, glycitur (meth)acrylate, glycitur acetate, glycisol lawalate, CARD
URA E (glycidyl ester of persatic acid,
(manufactured by Shell Chemical Co., Ltd.), butylglycidyl ether, octylglycidyl ether, phenylglycidyl ether, phenylclidibyl ether, p-tert-butylphenylglycidyl ether, allylglycidyl ether, and the like.

The amount of these 1,2-epoxy compounds used varies depending on the type of amino group to be converted into quaternary ammonium, etc.
Generally, it is convenient to use 2 to 4 times the molar amount in the case of a secondary amino group, and 1 to 2 times the molar amount in the case of a tertiary amino group.

On the other hand, examples of acids used in the quaternization reaction include:
Examples include organic acids such as formic acid, acetic acid, lactic acid, (meth)acrylic acid, propionic acid, butyric acid, and hydroxyacetic acid; and inorganic acids such as boric acid, hydrochloric acid, phosphoric acid, and sulfuric acid. These acids are 4
It is convenient to use about 1 to about 2 moles per aryne group to be ammoniated.

Further, water is suitably used in a proportion of about 0.5 to about 20 moles per amino group to be converted into quaternary ammonium.

One suitable method for converting the amino group derived from the aminoalkyl (meth)acrylic monomer (B)K in the copolymer into a quaternary ammonium is to convert the copolymer into a mixture of the copolymer and the above acid. , 1.2-epoxy compound and water are added and reacted at a temperature of room temperature to about 120° C. for about 1 to about 7 hours. Note that the amino group to be converted into quaternary ammonium is 2
When the secondary amine group is a 1,2-
It may be converted into a tertiary amino group by reaction with an epoxy compound, and then the tertiary amino group may be converted into a quaternary ammonium group.

The quaternary ammonium-formed copolymer should contain a sufficient amount of quaternary ammonium groups to render the cough copolymer water-soluble; It varies depending on the type, amount, weight, etc., but in general, it is 0.01 to 6
A range of milliequivalents/f copolymer, preferably 0.1 to 5 milliequivalents/f copolymer, more preferably 0.1 to 3 milliequivalents/f copolymer, is suitable.

The dispersant made of the copolymer made water-soluble as described above is generally used in an amount of about 1 to about 500 parts by weight, preferably about 1 to about 300 parts by weight per 100 parts by weight of the pigment. I can do it. When the amount of the dispersion agent used exceeds the upper limit of the range, there is a tendency for the aqueous pigment dispersion to have an imbalance between the coloring power and the viscosity, while when it exceeds the lower limit, the dispersion stability of the pigment tends to become unbalanced. Town 3c7 constancy tends to decrease.

The aqueous medium that can be used in the cationic aqueous pigment dispersion of the present invention is essentially water, but if necessary, for example, the degree of hydrophilicity of the dispersant is low and sufficient pigment dispersion performance cannot be obtained. In such cases, a hydrophilic organic solvent can be used in combination. As the hydrophilic organic solvent, the same ones used in the production of the polymer can be used alone or in combination. Furthermore, the pigments used in the aqueous thionic pigment dispersion of the present invention can be inorganic and organic pigments commonly used in pigment dispersions of this type. ) Oxide type (zinc white, titanium dioxide, red iron oxide, aluminum oxide, cobalt blue, iron black, etc.) 1 (2) Hydroxide type (alumina white, yellow iron oxide, etc.)' g (31 sulfide) ""'t
J, 1 (!“11・2・”Go to 7′”・.

raw, cadmium red, etc.) i (41 ferrocyanization 3
8- Physical system (prussian blue, etc.) etc.) i (81 silicate type (hydrated silicate, clay, ultramarine, etc.) l (9) phosphate type (manganese violet, etc.) + QI carbon type (carden black, etc.) aυ metal powder type (aluminum powder, bronze) powder, zinc powder, etc.), and organic pigments include (1) nitroso pigments (naphthol green B, etc.); (2) nitro pigments (naphthol El-, 5, etc.) H (31 azo pigments) (Lysol Red, Lake Red C1 Fast Yellow, Naphthol Red, Red, etc.); (4) Dyeing Lake Pigment System (Alkali/Rue Lake, Rhodamine Lake, etc.) Tomi (5) 7 Talocyanine Pigment System (Phtatecyanine Blue, Fast Sky (6) condensed polycyclic pigments (perylene red, quinacridone red, dioxazine violet, isoindolinone yellow, etc.).

The content of the pigment in the cationic aqueous pigment dispersion of the present invention is generally from about 2 to about 90% by weight based on the weight of the dispersion, although there are no particular technical limitations.

The cationic aqueous pigment dispersion of the present invention can be prepared by mixing together the above-mentioned components in a suitable dispersion device, and the dispersion device that can be used includes those commonly used in the paint industry. Examples include ball mills, roll mills, homo mixers, sand grinders, shakers, and attritors.

If necessary, conventionally known surfactants and protective colloids may be added to the cationic aqueous pigment dispersion of the present invention to improve dispersion stability.

In the cationic aqueous pigment dispersion of the present invention thus obtained, the pigment is very uniformly and finely dispersed, and the pigment particles hardly aggregate or settle even when stored for a long time.

Therefore, the cationic aqueous pigment dispersion of the present invention has 7
Alkyd resins used in water-based paints and inks,
Acrylic resin, polyurethane resin, cretan resin,
It has good miscibility with conventionally known water-soluble resins such as maleated polybutatsuene resins, water-dispersible resins, emulsions, etc., and is not limited by these resins at all, and is widely used for coloring water-based paints made of any resin. can do. It is particularly effective for cationic water-dispersible resins and polymeric emulsions which themselves have poor pigment dispersibility.

Although it can be varied within a certain range, in general, the amount of the pigment dispersion liquid is about 2.
It can be blended in a range of 1060 parts by weight to about 1060 parts by weight.

Next, the present invention will be explained in more detail with reference to Examples. In the examples, parts and % indicate parts by weight and % by weight.

Example 1 300 parts of n-butylcetetrasolve was placed in a reaction vessel and heated to 120°C. Next, mix the mixture in the proportions shown below.
They were added dropwise to this solution separately over about 2 hours.

The reaction was carried out under nitrogen injection while stirring the solution.

Stearyl methacrylate 113 parts N- vinyl-
A mixture of 93 parts of 2-pyrrolidone and 42 parts of 2-pyrrolidone; A mixture of 19 parts of azobistumethylvaleronitrile and 50 parts of n-butylcellosolve One hour after the completion of dropping the above mixture, 2.5 parts of azobisisobutyronitrile was added. Add to the reaction solution and after another 2 hours,
Add 25 parts of azobisisobutyronitrile to the reaction solution,
Thereafter, the reaction was carried out while maintaining the temperature at 120°C for 2 hours. After the reaction, the unreacted monomer and n-butyl cellosolve were distilled under reduced pressure, and the heating residue was 70.3% and the Gardner viscosity was 40%.
n-Butyl cellosolve solution) A copolymer solution of B was obtained.

Further, 179 parts of the copolymer solution was placed in a reaction vessel, heated to about 50°C, and after adding 6.690 parts of an 88% lactic acid aqueous solution, the temperature was further raised to 90°C and heated for about 30 minutes. After that, it was cooled to 50°C, and 1,2-butylene oxide 4,
Add 7 parts and 3.5 parts of water, raise the temperature to 110°C and boil
The mixture was reacted for a period of time to form a quaternary ammonium. The quaternary ammonium group content of the obtained copolymer was about 0.25 milliequivalent/copolymer. After cooling the obtained water-solubilized copolymer to room temperature, water was added to give 40% dispersant (I).
I got it.

Next, this dispersant (IJ & 3 parts and titanium white pigment (
A mixture of 200 parts of titanium white R-5# manufactured by Sakai Chemical Co., Ltd.
d Dispersion was carried out for 0.5 hours using a Devi1 dispersing machine to obtain an aqueous pigment dispersion L4) of the present invention.

Similarly, pigments were dispersed in the proportions shown in Table 1 below to obtain aqueous pigment dispersions (B) and (C) of the present invention. Pigments other than titanium white were dispersed for 1 hour.

The properties of the obtained cationic aqueous pigment dispersion are summarized in Table 1 below.

Next, formulations consisting of a pigment dispersion liquid and an aqueous resin shown in Table 2 below were sufficiently mixed to obtain aqueous paints (1) to (4). The coating film performance of the obtained water-based paint is summarized in Table 2 below.

Example 2 (2-a) The following components: Safflower oil fatty acid 23.6 parts Glycidyl methacrylate (119 parts) Hydroquinone 10.4 parts Tetraethylammonium bromide 0.2 parts were placed in a reaction vessel. The reaction was carried out at 140-150℃ while stirring.
The addition reaction product was obtained at a temperature of .

The addition reaction between epoxy and carboxyl groups was monitored while measuring the amount of xyl groups remaining. The reaction took approximately 4 hours to complete.

(3501 parts of 2-J n-butyl cellosolve was placed in a reaction vessel, heated to 120°C, and then a mixture in the proportions shown below was added dropwise to this solution over about 2 hours. The reaction was carried out by nitrogen injection. I went downstairs.

Fatty acid modified monomer obtained in (2-α) above 11.3 parts N-vinylpyrrolidone 126 parts N,N-dimethylaminoethyl methacrylate 11 parts azobisdimethylvaleronitrile 17 parts Reaction temperature 1
Keep the reaction solution at 20°C. While stirring, the above mixture was added dropwise and polymerization was carried out in the same manner as in Example 1. The heating residue was 70.6% and the Gardner viscosity (40% n
-butyl cellosolve solution) A copolymer solution of J was obtained. Furthermore, 211 parts of this copolymer solution was placed in a reaction vessel, the temperature was raised to about 50°C, 3.5 parts of an 88% lactic acid aqueous solution was added, and the temperature was raised to 70°C at 7'C. Add 25 parts of oxide and 2 parts of water and further raise the temperature to 110℃ for 46 minutes.
- and reacted for about 3 hours to form quaternary ammonium. The quaternary ammonium group content of the obtained copolymer was approximately 0.
It was a 2 meq/f copolymer. Water was added to this water-solubilized copolymer to obtain a 40% dispersant (II).

Next, using the obtained dispersant (II), the pigment shown in Clothing-1 below was dispersed in the same manner as in Example 1 to obtain an aqueous pigment dispersion CD> of the present invention.

In addition, a water-based paint (5) was prepared by thoroughly mixing this pigment dispersion (D) and the water-based resin shown in Coating-2 below.

The properties of the pigment dispersion CD) and the coating film performance of the water-based paint (5) are shown in Coating-1 and Table-2 below, respectively.

Example 3 (1-α) The following components: Isononanoic acid 133 parts Glycidyl methacrylate 119 parts Hyde tetraquinone 0.3 parts Tetraethylammonium bromide 0.2 parts were placed in a reaction vessel. The reaction was carried out at 140-150℃ while stirring.
The addition reaction product was obtained at a temperature of .

The addition reaction between the epoxy group and the carboxyl group was monitored while measuring the amount of the remaining carboxyl group. The reaction took approximately 4 hours to complete.

(1-b) The following components: Synthetic fatty acid modified monomer 113 obtained in (1-11E) above
A mixture of 115 parts of N,N-dimethylacrylamide and 17 parts of azobistumethylvaleronitrile and 50 parts of n-butyl cellosolve was subjected to a polymerization reaction according to the method described in Example 1. Heating residue 70.3%, Gardner viscosity (40% n-
Butyl cellosolve solution) A copolymer solution of A was obtained.

Furthermore, 180 parts of this copolymer solution was put into a reaction container,
After raising the temperature to about 50°C and adding 6.6 parts of 88% lactic acid aqueous solution, the temperature was raised to 80°C, and 47 parts of 1,2-butylene oxide was added.
15 parts of water were added thereto, and the mixture was further reacted at 110° C. for about 2.5 hours to form a quaternary ammonium. The quaternary ammonium group content of the resulting copolymer was approximately 0.3 milliequivalents/copolymer. Water was added to this water-solubilized copolymer to obtain a 40% dispersant θ19.

Next, using the dispersant obtained in Example 1, the pigment shown in Example 1 was dispersed in the same manner as in Example 1 to obtain an aqueous pigment dispersion (A') of the present invention.

In addition, a water-based paint (6) was prepared by sufficiently mixing this pigment dispersion CE) and the water-based resin shown in Coating-2 below.

The properties of the pigment dispersion CB> and the coating film performance of the water-based paint (6) are shown in Coating-1 and Table-2 below, respectively.

49-Example 4 A mixture of fatty acid modified monomers obtained in (2-α) 102 parts N-vinylpyrrolidone 9 parts 2 parts acrylic acid 11 parts N,N-tumethylaminopropylmethacrylamide 44 parts and azobis A mixture of 17 parts of trimethylvaleronitrile and 50 parts of exo-butyl cellosolve was subjected to a polymerization reaction according to the method described in Example 1. Heating residue 71.0%, Gardner viscosity (40% n-
Butyl cellosolve solution) A copolymer solution of H was obtained.

Furthermore, 180 parts of this copolymer solution was put into a reaction container,
After raising the temperature to about 50°C and adding 7.7 parts of acetic acid, the temperature was raised to 80°C, and 9.4 parts of 1,2-butylene oxide and 7 parts of water were added.
．． 0 parts was added thereto, and the temperature was further raised to 110° C. for about 3.5 hours to form a quaternary ammonium. The quaternary ammonium group content of the obtained copolymer was about 0.5 milliequivalent/f copolymer. Water was added to this water-solubilized copolymer to obtain a 40% dispersion 4.

Next, the pigments shown in Table 1 below were dispersed using the obtained dispersant in the same manner as in Example 1 to obtain an aqueous pigment dispersion <F) of the present invention.

In addition, a water-based paint (7) was prepared by thoroughly mixing this pigment dispersion (F) and a water-based resin shown in Table 2 below.

The properties of the pigment dispersion (F) and the coating film performance of the water-based paint (7) are shown in Tables 1 and 2 below, respectively.

Example 5 N-vinylpyrrolidone 83 parts N,N-? A mixture of 44 parts of methylaminoethyl methacrylate and 30 parts of n-butyl methacrylate and 18 parts of azobisdimethylvaleronitrile and 50 parts of extra-butyl cellosolve was subjected to a polymerization reaction according to the method described in Example 1. Heating residue 70.4%, Gardner viscosity (40% n-
Butyl cellosolve solution) A copolymer solution of C was obtained.

Furthermore, 180 parts of this copolymer solution was put into a reaction container,
The temperature was raised to about 50°C, 13.2 parts of 88% lactic acid aqueous solution was added, and then the temperature was raised to about 90°C, and butyl glycidyl ether
7. and 7.0 parts of water were added, and the mixture was reacted at 120° C. for about 3 hours to form quaternary ammonium. The quaternary ammonium group content of the obtained copolymer was approximately 0.45 milliequivalent/
was a copolymer. Water was added to this water-solubilized copolymer to obtain 40% dispersant M.

Next, using the obtained dispersant M, a pigment shown in fi-IK below was dispersed in the same manner as in Example 1 to obtain an aqueous pigment dispersion (G) of the present invention.

'Also, water-based paint +8) was prepared by thoroughly mixing this pigment dispersion (G) and the water-based resin shown in Table 2 below.

The properties of the pigment dispersion (G) and the film performance of the water-based paint (8) are shown in Tables 1 and 2 below, respectively.

53- *1 Titanium white R-5N', tita carbon oxide made by Sakai Chemical Co., Ltd. (: L Tan Kasei carbon *2 Measured according to ASTM D1201-64 54-r: 0 Straight*3 Engineering I 1002, a polyamide resin, a cationic resin consisting of a blocked product of Cyphenylmethane Soisocyanate. Amine (milliequivalent/f resin) =, Resin viscosity (60
% n-butyl cellosolve solution > z, f Contains 30% by weight of L-butyl cellosolve. Neutralize with 0.3 equivalents of acetic acid and add water to create a dispersed emulsion with a solid content of 40%.

×4 Product name [Cementex-C] (manufactured by Obanaya Sangyo) Cationic styrene-butadiene latex solid content =
30% Paint film curing conditions: 180°C for 30 minutes (2
) at 20°C (relative humidity 75%) - Dry for 7 days 56 - [Coating film performance test] Water-based paints (1) to (8) were coated with a water-based dryer (trade name "Diknate 1" manufactured by Dainippon Ink Co., Ltd., cobalt metal content 3). %
) was added at a ratio of 1 part to 100 parts of resin solid content and coated on a mild steel plate. After drying at 20° C. and 75% relative humidity for 3 days, it was used for testing.

Adhesiveness of dimples: 100 diagonal diagonals of 1 width were made, a cellophane adhesive tape was placed on top of the dimples, and the adhesive tape was peeled off vigorously for testing.

Water resistance: The coated surface was immersed in tap water at 20° C. for 2 days and the condition of the coated surface was visually examined.

Claims (1)

[Scope of Claims] In an aqueous pigment dispersion containing a pigment, a dispersant, and an aqueous medium, the dispersant is (A) modified with an oil or fat fatty acid or a synthetic saturated fatty acid (
3 to 98 parts by weight of meth)acrylic monomer (B) Aminoalkyl (meth)acrylate or aminoalkyl (meth)acrylamide monomer 1 to 97
Part by weight (C) 0 to 96 parts by weight of α, β-ethyically unsaturated nitrogen-containing monomer other than the above CB>, and (D) α other than the above (A), CB>, and (C). A cationic aqueous pigment dispersion, characterized in that it is a water-soluble copolymer obtained by copolymerizing and converting the amine groups present in the resulting copolymer into quaternary ammonium.