JPH01138270A - Production of surface-treated organic pigment - Google Patents

Abstract

PURPOSE:To obtain easily the title pigment which has a uniformly treated surface, in which the polymer and the organic pigment are firmly bonded together and which is good in dispersibility in various substances, by mixing an organic pigment with a specified polymer component under agitation under specified conditions. CONSTITUTION:The title pigment is easily produced by mixing an organic pigment (e.g., azoic or phthalocyanine pigment) with a poly(oxazoline) and/or a modified poly(oxazoline) (e.g., 2-ethyl-2-oxaxoline or its modification) under agitation at 0-400 deg.C. This process provides a surface-treated organic pigment which has a uniformly treated surface as compared with a conventional surface- treated organic pigment and in which the polymer used in the treatment is firmly bonded to the organic pigment. Because the polymer used has a high affinity for various substances, the obtained pigment is excellent in dispersibility in organic solvents, water, plastics, fibers, etc., and excels in color forming property, hiding power, etc. Therefore, it can be suitably used as a colorant for inks, toners, paints, fibers, plastics, rubbers, paper, etc.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for producing surface-treated organic pigments.

Specifically, the present invention relates to a manufacturing method for easily obtaining a surface-treated organic pigment useful as a coloring agent for ink, toner, paint, fiber, plastic, rubber, paper, etc., which has been surface-treated with a specific polymer component.

(Prior art and problems to be solved by the invention) Organic pigments are generally fine powders that are insoluble or poorly soluble in water and solvents, such as inks, toners, paints, fibers, plastics, etc.
It is widely used as a coloring agent for rubber, paper, etc.

Organic pigments are powdery or granular, so they are rarely used alone; they are usually dispersed uniformly in solid base materials such as rubber or plastic, or liquids such as water or solvents. For the first time, it exhibits properties such as color development and hiding power.

However, compared to the cohesive force between particles, organic pigments
For example, it has a weak affinity with organic polymers, water, organic solvents, etc., so it has been extremely difficult to mix or disperse them uniformly under normal mixing or dispersion conditions.

In order to solve this problem, the surface of organic pigments is coated with various surfactants and resins, and treated with various coupling agents to increase their affinity with solid or liquid base materials. Many methods have been investigated for uniformly mixing or dispersing organic pigments into these substrates.

However, the compatibility of the organic pigments obtained by coating and treating the surface with these methods with solid or liquid substrates was not improved as much as expected, and it was difficult to disperse them depending on the mixing or dispersion conditions. The current situation is that satisfactory results are not necessarily obtained.

(Means and effects for solving the problem) In view of the current situation, the present inventors have conducted intensive studies on a method for easily and stably producing organic pigments with excellent dispersibility in various substances. As a result, they discovered that an organic pigment that completely satisfies the above objectives can be obtained by an extremely simple method of stirring and mixing an ordinary organic pigment and a specific polymer component under specific conditions, and completed the present invention. I ended up doing it.

That is, the present invention combines an organic pigment and poly(oxazoline) (al
and/or poly(oxazoline) modified product (b) (hereinafter,
Collectively called polymer prisoners. ) and is stirred and mixed under a temperature condition of 0 to 400°C.

Examples of the organic pigment in the present invention include organic pigments that are widely used today, such as azo-based, condensed azo-based, phthalocyanine-based, ψ
Jianxi dye system, oxazine system,
Such pigments include quinacridone-based pigments and kitanophthalone-based pigments.

Poly(oxazoline) (a) of the polymers used for surface treatment of organic pigments in the present invention is represented by the following formula % (wherein R', R", R", R', R' It is a homopolymer or copolymer of a substituted 2-oxazoline represented by (-resol independently represents hydrogen, halogen, alkyl, aralkyl, phenyl, or substituted phenyl), and is easily available. -2-oxazoline (in the formula R"-R"-R-R'=H) (D is a homopolymer or copolymer.

A specific example of poly(oxazoline) (a) is poly(2
-oxazoline), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(
Homopolymers such as poly(2-isopropyl-2-oxazoline), poly(2-cyclohexyl-2-oxazoline) or poly(2-phenyl-2-oxazoline), 2-ethyl-2-oxazoline and 2-phenyl-2- Copolymer with oxazoline, 2-ethyl-2-oxazoline and 2-
Copolymer with cyclohexyl-2-oxazoline, 2-
Examples include a copolymer of ethyl-2-oxazoline and ethyleneimine, a copolymer of 2-ethyl-2-oxazoline and propylene oxide, and a copolymer of 2-phenyl-2-oxazoline and tetrahydrofuran. Among these, 2-ethyl-2-oxazoline, 2-phenyl-2-oxazoline and 2-cyclohexyl-2-
Poly(oxazoline) obtained using one or more 2-oxazoline monomers selected from oxazolines as a main component is preferred.

In addition, as the poly(oxazoline) modified product (b) of the polymer particles in the present invention, the above-mentioned poly(oxazoline)
Examples include partial hydrolysates of (a), and graft reaction products of these partial hydrolysates with alkylene oxides such as ethylene oxide and propylene oxide and/or alkylene imines such as ethylene imine and propylene imine.

As mentioned above, when obtaining the polymer prisoner in the present invention,
Alkylene imines such as ethyleneimine and propylene imine, alkylene oxides such as ethylene oxide and propylene oxide, etc. may be used as the copolymerization component of 2-oxazoline without departing from the purpose of the present invention. It is preferable to use these alkylene imines and alkylene oxides in an amount of 50 molar or less based on the total monomers.

A polymer having a molecular weight in the range of 1,000 to 1,000,000 is preferably used, but it is preferable that the organic pigment can be efficiently crushed when the organic pigment is treated, and that the organic pigment has good dispersibility in various substances after surface treatment. In order to further increase
In particular, it is preferable to use a high molecular weight.

The method for producing a surface-treated organic pigment of the present invention comprises combining an organic pigment and one or more of the polymer particles at a concentration of 0 to 400%.
This is achieved by mixing and stirring at a temperature of 20-350'C. Temperatures above 400'C are not preferred because the quality of the polymer particles changes.

Obtaining an organic pigment whose surface has been treated with a polyoxazoline component is not necessarily achieved only by the production method of the present invention, but can also be achieved by other methods such as, for example, a method of polymerizing a 2-oxazoline monomer in the presence of an organic pigment. However, other methods do not provide sufficient dispersibility into various materials. That is, in the method of polymerizing 2-oxazoline monomer in the presence of an organic pigment, it is difficult to disintegrate the organic pigment in a secondary agglomerated state, and the organic pigment in the form of coarse particles remains mixed in the resulting product. .

On the other hand, the surface-treated organic pigment obtained by the production method of the present invention is crushed into a state close to higher-order particles during production, so the resulting product has a small and uniform particle size. Furthermore, the molecular weight of the polymer particles used to treat organic pigments has an important effect on dispersibility in various materials, and it is usually preferable to control the molecular weight to a high level. It is extremely difficult to control the molecular weight to a desired value.

As a specific embodiment of the production method of the present invention, for example, an organic pigment of m 1 fm or more and one or more polymer particles are mixed with stirring under a temperature condition of 0 to 400°C, preferably 20 to 350°C, and the surface (2) one or more organic pigments and one or more polymer particles in a suitable dispersion medium (e.g., polymeric substance, organic solution) at a temperature of 0 to 400°C, preferably 20 to 350°C; Examples include a method of surface treatment by stirring and mixing under certain conditions.

When treating an organic pigment with polymer (5), the ratio of the polymer matrix and the organic pigment used is not particularly limited. In order to obtain surface-treated organic pigments with improved dispersibility in various substances and effectiveness as a modifier for resins, the ratio of organic pigment/polymer is 100/1 to 100/1. It is preferably 1000, and more preferably in the range of 10015 to 500. In addition, antioxidants, heat stabilizers, surfactants, lubricants, polymeric substances other than the polymer particles, etc. may be added as additives as necessary during or after the reaction between the organic pigment and the polymer particles. good.

(Effects of the Invention) The surface-treated organic pigment obtained by the production method of the present invention has a more uniform surface treatment state than organic pigments whose surface has been treated by the conventional method. It is made up of a strong bond between the polymer matrix used in the process and the organic pigment. In addition, the polymer particles used in the treatment have a high affinity with various substances, and the surface-treated organic pigments of the present invention have excellent dispersibility in organic solvents, water, plastics, fibers, etc. , excellent color development, hiding power, etc.

Therefore, the surface-treated organic pigment obtained according to the present invention can be suitably used as a coloring agent for, for example, ink, toner, paint, fiber, plastic, rubber, paper, and the like.

The present invention provides a method for easily and stably producing a surface-treated organic pigment having the above characteristics.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples. Note that "parts" in the examples are by weight unless otherwise specified.

Example 1 40 parts of poly(2-ethyl-2-oxazoline) having a weight average molecular weight of 200,000 and 40 parts of phthalocyanine blue were heated at 160°C for 10 minutes using a Laboplastomill (manufactured by Toyo Seiki ■).
After reaction by kneading for 15 minutes at 0 rpm, the mixture was cooled and pulverized to obtain the surface-treated organic pigment (1) of the present invention.

This surface-treated organic pigment (1) was added at 15% per 100 parts of polystyrene resin (manufactured by Asahi Kasei ■, Styron 666).
A molded article was produced by injection molding. This molded product was light and dark in color.

Example 2 The surface was prepared in the same manner as in Example 1, except that poly(2-cyclohexyl-2-oxazoline) having a weight average molecular weight of 80,000 was used instead of poly(2-ethyl-2-oxazoline). The treated organic pigment (2) was obtained, and a molded article was produced in the same manner as in Example 1. This molded product was light and dark in color.

Example 3 In Example 1, 2-ethyl-2-oxazoline 2 was added to 40 parts of poly(2-ethyl-2-oxazoline).
Oxazoline copolymer obtained from 0 parts and 20 parts of 2-phenyl-2-oxazoline (weight average molecular weight 50,000) 4
A surface-treated organic pigment (3) was obtained by repeating the same operation as in Example 1, except that 0 part was used, and a molded article was produced in the same manner as in Example 1. This molded product was light and dark in color.

Example 4 20 parts of poly(2-ethyl-2-oxazoline) having a weight average molecular weight of 200,000 was dissolved in 80 parts of deionized water, and 1 part of concentrated hydrochloric acid was dissolved.
．． After adding 8 sides and reacting at a temperature of 100°C for 7 hours, the generated propionic acid was distilled off, and then diluted with water to obtain poly(
A 20% aqueous solution of 2-ethyl-2-oxazoline (2-ethyl-2-oxazoline) partial hydrolyzate hydrochloride was obtained.

A 20% aqueous solution of the above-mentioned poly(2-ethyl-2-oxazoline) partial hydrolyzate hydrochloride was treated with anion exchange resin Amberlite InA-410 (manufactured by Organo ■), dried, and pulverized. (2-oxazoline) partial hydrolyzate was obtained.

The same procedure as in Reference Example 1 was repeated except that the poly(2-ethyl-2-oxazoline) partial hydrolyzate was used as the glue for the poly(2-ethyl-2-oxazoline) in Example 1. The treated organic pigment (4) was obtained, and a molded article was produced in the same manner as in Example 1. This molded product was light and dark in color.

Comparative Example 1 In Example 1, surface-treated organic pigment (1) 15
A molded article was produced in the same manner as in Example 1 except that 5 parts of phthalocyanine blue was used as it was instead of 5 parts.

This molded product was dull and pale in color.

Example 5 Example 1 except that an azo organic pigment, Lake Red C, is used instead of phthalocyanine blue.
The dispersibility and stability in an organic/toluene-1/1 mixed solvent, which was surface-treated in the same manner as above, are as shown in Figure 1.

Example 6 Example 2 except that an azo organic pigment, Lake Red C, was used for the phthalocyanine blue color.
A surface-treated organic pigment (6) was obtained in the same manner as above.

The dispersibility and stability of this surface-treated organic pigment (6) in water and MEK/toluene-1/1 mixed solvent are as shown in Table 1.

Example 7 Example 3 except that an azo organic pigment, Lake Red C, was used for the phthalocyanine blue color.
A surface-treated organic pigment (7) was obtained in the same manner as above.

This surface-treated organic pigment (dispersibility and stability in water and MEK/toluene = 1/1 mixed solvent is shown in Table 1.
This is as shown.

Example 8 Example 4 except that an azo organic pigment, Lake Red C, is used instead of phthalocyanine blue.
A surface-treated organic pigment (8) was obtained in the same manner as above.

The dispersibility and stability of this surface-treated organic pigment (8) in water and MEK/toluene=1/1 mixed solvent are as shown in Table 1.

Comparative Example 2 Lake Red C used in Example 5 was used as it was without surface treatment, and its water and MEK/toluene-1/
1 The dispersibility and stability in mixed solvents were investigated. The results are shown in Table 1.

-1/1 mixed solvent (Note 2) Dispersibility: Disperse various inorganic pigments in 200 parts of water or organic solvent in an amount such that the titanium oxide rich component is 10 parts, and pass through a No. 3 glass filter. The amount of components remaining in a part of the glass filter was investigated.

O... None x... Large amount (Note 3) Dispersion stability = (According to the procedure in Note 2) p No,
The stability of the dispersion over time after passing through the glass filter No. 3 was investigated.

○...Sediment remains even after more than half a year has passed is not seen at all.

×・・・Sediment will occur within half a year. Ru.

Claims (1)

[Claims] 1. A surface characterized by stirring and mixing an organic pigment and poly(oxazoline) (a) and/or modified poly(oxazoline) (b) under a temperature condition of 0 to 400°C. Method for producing treated organic pigments. 2. The method for producing a surface-treated organic pigment according to claim 1, wherein the poly(oxazoline) (a) and/or the poly(oxazoli) modified product (b) has a molecular weight in the range of 1,000 to 1,000,000. . 3. Poly(oxazoline) (a) is 2-ethyl-2-oxazoline, 2-phenyl-2-oxazoline and 2-
2. A method for producing a surface-treated organic pigment according to claim 1, which is obtained by using as a main component one or more 2-oxazoline monomers selected from cyclohexyl-2-oxazoline. 4. Poly(oxazoline) modified product (b) is 2-ethyl-
Modification of poly(oxazoline) (a) obtained using as a main component one or more 2-oxazoline monomers selected from 2-oxazoline, 2-phenyl-2-oxazoline and 2-cyclohexyl-2-oxazoline A method for producing a surface-treated organic pigment according to claim 1, which is a product.