JPH03182503A - Nonaqueous resin dispersion - Google Patents

Abstract

PURPOSE:To obtain a nonaqueous resin dispersion of improved dispersion stability by copolymerizing a vinyl monomer mixture in a specified nonaqueous solvent to disperse a chain polymer insoluble therein in that solvent. CONSTITUTION:A dispersion obtained by copolymerizing a vinyl monomer mixture containing a vinyl monomer, which constitutes a vinyl copolymer insoluble in a nonaqueous solvent containing a carboxylated, sulfonated or phosphorylated vinyl copolymer soluble therein, in the solvent. This dispersion is a nonaqueous resin dispersion wherein the chain polymer whose molecules are entangled with each other and which is insoluble as a whole in the solvent are dispersed in the solvent. The chain polymer is useful as a polymer used for a liquid developer for electrostatic latent images or a coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a non-aqueous resin dispersion useful for liquid developers for electrostatic latent images, paints, and the like.

[Conventional technology]

Various proposals have been made regarding nonaqueous resin dispersions used in liquid developers for electrostatic latent images, paints, etc., and methods for producing the same. For example, Special Public Interest Publication No. 60-17331
In the method for producing a non-aqueous resin dispersion described in the publication,
In a non-aqueous solvent, a monomer represented by the general formula (1) % formula % (wherein R represents H or CR2, and n represents an integer of 8 to 20) and a monomer having a glycidyl group or a carboxyl group. 1st step of copolymerizing with a specific monomer, if the copolymer obtained in the 1st step is used as a monomer having a glycidyl group in the 1st step, a monomer having a carboxyl group is used in the 1st step. When a monomer having a carboxyl group is used, the step of esterifying each monomer with a monomer having a glycidyl group and the resulting esterified copolymer are combined with the general formula (n) CHz=C-
Grafting a monomer selected from the group consisting of a compound represented by COOC, Ht, ++ (in the formula, m represents an integer from 1 to 4), vinyl acetate, styrene, vinyltoluene, vinylpyridine, and chlorostyrene. A method of manufacturing a non-aqueous resin dispersion by continuously performing the second step is known.

However, since this method increases the esterification rate, it is possible to efficiently produce a grafted non-aqueous resin dispersion, but a relatively large amount of grafted resin is produced as a by-product during the production of the graft polymer. Polymers soluble in non-aqueous solvents and polymers insoluble in non-aqueous solvents impair the dispersibility of pigments and dyes, resulting in the problem of sedimentation during long-term storage.

[Problem to be solved by the invention]

The problem to be solved by the present invention is to provide a non-aqueous resin dispersion that can maintain good dispersion stability even after long-term storage by improving dispersibility for pigments and dyes.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a non-aqueous solvent containing a vinyl copolymer having a carboxyl group, a sulfo group, or a phosphoric acid group that is soluble in a non-aqueous solvent. Insoluble in the non-aqueous solvent as a whole captured by the mutual entanglement of molecular chains obtained by copolymerizing a vinyl monomer mixture containing a vinyl monomer (hereinafter referred to as the third monomer component) constituting the vinyl copolymer. A non-aqueous resin dispersion is provided, characterized in that the chain polymer of the present invention is dispersed in the non-aqueous solvent.

The vinyl copolymer having a carboxyl group, a sulfo group, or a phosphoric acid group that is soluble in a non-aqueous solvent used in the present invention has the following formula: (a) General formula (A) 1 CHt = C-COOR" (wherein, R1 is hydrogen or a methyl group, and R1 represents an alkyl group having 6 to 24 carbon atoms.) and/or a vinyl monomer represented by the general formula (B) CH! -24 alkyl group) (hereinafter referred to as the first monomer component) 70 to 97% by weight, (bl represents a vinyl monomer having a carboxyl group, sulfo group or phosphoric acid group (hereinafter referred to as the second monomer component)) It is called a monomer component.

)3 to 30% by weight and (C1 if necessary, other copolymerizable vinyl monomers (
Hereinafter, it will be referred to as the fourth monomer precept. ) in the presence of a polymerization initiator in a non-aqueous solvent.
It can be produced by copolymerizing at 0 to 130°C.

The non-aqueous resin dispersion of the present invention constitutes a vinyl copolymer insoluble in the non-aqueous solvent in the non-aqueous solvent containing the vinyl copolymer having a carboxyl group, a sulfo group, or a phosphoric acid group. By copolymerizing a vinyl monomer mixture containing a vinyl monomer (hereinafter referred to as the third monomer component) in the presence of a polymerization initiator at 60 to 130°C, the entire body is captured by the entanglement of molecular chains. It can be produced by producing a chain polymer insoluble in the non-aqueous solvent and dispersing the chain polymer in the non-aqueous solvent.

The first monomer component used in the present invention is a monomer that constitutes a vinyl copolymer that dissolves in a non-aqueous solvent through polymerization, such as hexyl (meth)acrylate, 2-
Ethylhexyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cetyl (meth)acrylate, dodecyl (meth)acrylate, vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate etc.

If the content of the first monomer component is less than 70% by weight, the resulting vinyl copolymer will have poor solubility in non-aqueous solvents, so the chain-like polymer obtained by polymerizing the third monomer component will be This is not preferred because the dispersion stability of the coalescence tends to deteriorate.

In addition, when the content of the first monomer component is more than 97% by weight, the mutual stitching of the molecular chains of the second monomer component and the third monomer component, which constitute the structural part insoluble in the non-aqueous solvent, is reduced. This is not desirable as it tends to be

The second monomer component used in the present invention is copolymerized with the first monomer component and apparent crosslinking occurs due to the interaction between acid groups, so that when the vinyl monomer mixture containing the third monomer component is polymerized, In addition, polymerization occurs while being trapped in a pseudo three-dimensional crosslinked structure part that is insoluble in non-aqueous solvents and is composed of the second monomer, so three-dimensional threads between molecular chains can be formed. .

Examples of such second monomers include (meth)acrylic acid; itaconic acid, crotonic acid, maleic acid,
Examples include fumaric acid, tetrahydrophthalic anhydride, and polybasic acid monoalkyl esters thereof; acryloxyethyl phosphate; p-sulfostyrene/sulfoethyl acrylamide;

The third seventh component used in the present invention is a vinyl monomer that constitutes a vinyl copolymer that is insoluble in non-aqueous solvents by polymerization, and has the following formula: where R1 represents a hydrogen atom or a methyl group, and R2 represents an alkyl group having 1 to 5 carbon atoms;
) CHx = CH-OCOR” ・・・・・・(I
I) (In the formula, R2 represents an alkyl group having 1 to 5 carbon atoms.) Saturated fatty acid vinyl ester represented by the general formula ([) % formula % () (In the formula, R1 represents an alkyl group having 1 to 5 carbon atoms. dialkyl ester of an unsaturated dicarboxylic acid represented by (5); the second monomer component; dimethylaminoethyl (meth)acrylate, diethylamino (meth)acrylate, N-vinylimidazole, l-vinylpyrrole, N-
Nitrogen atoms in molecules such as β-acryloxyethylindole, 2-vinylquinoline, 4-vinylpyridine, N-vinyl-2-pyrrolidone, N-vinyloxazolidone, dimethylaminostyrene, (meth)acrylamide, (meth)acrylonitrile, etc. A vinyl monomer having a hydroxyl group such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybityl (meth)acrylate, 2-hydroxy-3-chloropropyl (meth)acrylate; 2
- Vinyl monomers having an ether group such as methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate; Vinyl monomers having a glycidyl group such as glycidyl (meth)acrylate, etc. I can do it.

In particular, a vinyl monomer represented by general formula (1) or -general formula (I[), a second monomer component, a nitrogen atom, a hydroxyl group,
A tertiary vinyl monomer fraction containing vinyl monomers having an ether group or a gyricidyl group is preferred.

As the fourth monomer component, the third monomer component; a dialkyl ester of an unsaturated dicarboxylic acid represented by the general formula (IV) R80COCH=CHCOOR3 (wherein, R3 represents an alkyl group having 6 to 18 carbon atoms); ; halogen atom-containing vinyl monomers such as 2-chloroethyl (meth)acrylate and 3-bromopropyl (meth)acrylate; vinyl monomers having a ketone group such as vinyl methyl ketone and vinyl isopropynyl ketone;
Examples include aromatic vinyl monomers such as styrene, vinyltoluene, and α-methylstyrene.

Examples of non-aqueous solvents include n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane, and n-dodecane. ”, “Isopar H”, “Isopar K”, “Isopar LJ”, “Isopar M”, etc.
It has a boiling point in the temperature range of 68-250℃ and has a resistance of 10”Ω
・Various hydrocarbon solvents having a volume resistivity of less than 3 and a dielectric constant of less than 3 and, if necessary, ordinary organic solvents can be used.

As the above-mentioned ordinary organic solvent, an organic solvent having a solubility parameter (hereinafter referred to as SP) of 9.0 or less, for example,
Cyclohexane, xylene, toluene, etc. can be used as necessary.

Examples of the polymerization initiator used in the copolymerization reaction include azobisisobityronitrile, benzoyl peroxide,
Di-tertiary butyl peroxide, tertiary
Examples include butyl peroxybenzoate, and the amount used is preferably in the range of 0.1 to 100% by weight of the monomer components.

The ratio of the non-aqueous solvent-soluble vinyl copolymer to the third monomer component is 20=80 to 90:10 by weight.
A range of is preferred. The usage ratio of the third monomer is 10
If it is less than % by weight, the amount of pigment or dye adsorbed onto the chain polymer will decrease, and as a result, when a liquid developer or paint is prepared using the non-aqueous resin dispersion of the present invention, the dispersion stability will be reduced. Also, if the proportion of the third monomer component used is more than 80% by weight, the solubility of the chain polymer in non-aqueous solvents will deteriorate, and as a result, the This is not preferred because it tends to result in poor dispersion stability when preparing a liquid developer or paint.

The chain polymer of the present invention produced in this manner is -3
It is insoluble in non-aqueous solvents in the temperature range of 0 to 50°C.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the spirit thereof. In the examples, "parts" and "%" represent "parts by weight" and "% by weight," respectively.

Examples 1 to 5 and Comparative Examples Production of Soluble Copolymers Copolymers soluble in non-aqueous solvents were produced using the formulations and synthesis methods listed in Table 1.

For comparison, a polymer was also produced without using the second monomer.

Production of light chain polymer A light chain that becomes insoluble in the non-aqueous solvent by polymerizing the third monomer component in a non-aqueous solvent containing a copolymer soluble in the non-aqueous solvent listed in Table 2. A polymer was produced.

For comparison, a milky white emulsion was obtained by polymerizing the third monomer in a non-aqueous solvent containing a polymer soluble in the non-aqueous solvent of Comparative Example. that time,
The formulation composition and synthesis method described in the same table were set.

As is clear from these results, each of the light chain polymers of Examples had good dispersion stability after standing for one month.

However, in the copolymer of the comparative example, since the molecular chains were not mixed together, the dispersion stability after standing for one month was poor, and the occurrence of sediment was observed.

〔Effect of the invention〕

The non-aqueous solvent-insoluble chain polymer of the present invention is mainly composed of vinyl monomers constituting the non-aqueous solvent-insoluble vinyl copolymer among specific vinyl copolymers soluble in non-aqueous solvents. By copolymerizing a vinyl monomer mixture, a non-aqueous resin in which a copolymer soluble in a non-aqueous solvent and a copolymer insoluble in a non-aqueous solvent are integrally bonded to each other, are captured by the entanglement of molecular chains. Since it forms a dispersion, it is stably dispersed in a non-aqueous solvent.

The light chain polymer of the present invention having such excellent dispersion stability is useful as a polymer used in various liquid developers or paints for electrostatic latent images.

Claims (1)

[Scope of Claims] 1. A vinyl copolymer insoluble in the non-aqueous solvent in the non-aqueous solvent containing a vinyl copolymer having a carboxyl group, a sulfo group, or a phosphoric acid group that is soluble in the non-aqueous solvent. The chain polymer, which is insoluble in the non-aqueous solvent as a whole and is captured by the entanglement of molecular chains obtained by copolymerizing a vinyl monomer mixture containing vinyl monomers constituting the polymer, is dispersed in the non-aqueous solvent. A non-aqueous resin dispersion characterized by comprising: 2. The content of the vinyl copolymer having a carboxyl group, sulfo group or phosphoric acid group soluble in a non-aqueous solvent is 3 to 30% by weight of the vinyl copolymer soluble in a non-aqueous solvent. Non-aqueous resin dispersion. 3. The vinyl monomer that makes up the vinyl copolymer that is insoluble in non-aqueous solvents has the general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (In the formula, R^1 represents a hydrogen atom or a methyl group, and R^
2 represents an alkyl group having 1 to 5 carbon atoms. ) The non-aqueous resin dispersion according to claim 1 or 2, which contains a vinyl monomer represented by: 4. The vinyl monomer constituting the vinyl copolymer insoluble in non-aqueous solvents has the general formula CH_2=CH-OCOR^2 (wherein, R^2 represents an alkyl group having 1 to 5 carbon atoms). Claim 1 or 2 containing the vinyl monomer represented by
Non-aqueous resin dispersion as described. 5. The non-aqueous resin dispersion according to claim 1 or 2, wherein the vinyl monomer constituting the vinyl copolymer insoluble in the non-aqueous solvent contains a vinyl monomer having a carboxyl group, a sulfo group, or a phosphoric acid group. 6. The non-aqueous resin dispersion according to claim 1 or 2, wherein the vinyl monomer constituting the vinyl copolymer insoluble in the non-aqueous solvent contains a vinyl monomer having a nitrogen atom, a hydroxyl group, or an ether group. 7. The non-aqueous resin dispersion according to claim 1 or 2, wherein the vinyl monomer constituting the vinyl copolymer insoluble in the non-aqueous solvent contains a vinyl monomer having an epoxy group.