JP2954654B2 - Dispersant for colorant for synthetic resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a colorant composition for a synthetic resin having excellent pigment dispersibility.

[Prior art] Generally, when coloring synthetic resins such as olefin resins, styrenic resins, and vinyl chloride resins, a method of using a pigment is used, and in most cases, in order to improve the dispersibility of the pigment. A colorant obtained by mixing a dispersant with a pigment is used. As a dispersant in the colorant, metal soaps represented by zinc stearate, waxes, higher fatty acids, amide compounds, and the like have been used so far. Which do not completely satisfy the problems derived from the aggregation of pigments (poor dispersion). In the case of coloring with an organic pigment characterized by sharpness of the color, the problem is particularly remarkable.

[Problems to be solved by the invention]

The present invention is to improve the dispersibility of pigment particles in a resin when coloring a synthetic resin, and to solve various problems such as variation in coloring degree (unclear color) and uneven color by improving the dispersibility. It is assumed that.

[Means for solving the problem]

The present invention has been made as a result of intensive studies on a dispersant for improving the dispersibility of a pigment in a synthetic resin such as an olefin resin, a styrene-based resin, and a vinyl chloride resin, and as a result, a C _{16 to} C ₂₀ saturated hydroxy fatty acid having a hydroxyl group at a side position. The present inventors have found that glycerin esters remarkably improve the dispersibility of the pigment and can produce a colored resin molded article with the above-mentioned disadvantages improved, thereby completing the present invention.

The dispersant of the present invention exhibits an excellent dispersing effect when used alone, and significantly improves the dispersing effect of the known dispersing agent when used in combination with a known dispersing agent (especially waxes represented by polyethylene wax). I do.

Has a hydroxyl group at the side position which is an active ingredient of the dispersant of the present invention.
The C ₁₆ -C ₂₀ saturated hydroxy fatty acid glycerol ester, hydroxy palmitic acid, hydroxy stearic acid, and the like from the configured glycerol ester hydroxy eicosane acid, are suitable in particular 12-hydroxystearic acid glyceryl ester.

These saturated hydroxy fatty acid glycerin esters having a hydroxyl group at the side position may be each of mono-, di- and triesters or a mixture thereof. However, particularly preferred are mixtures having a monoester content of 50% or more.

The amount of the dispersant of the present invention relative to the pigment is excellent when the dispersant alone is used as the dispersant, and the dispersant is used in an amount of 1 to 200 parts by weight based on 100 parts by weight of the pigment. Is shown. In addition, when used in combination with a known dispersant, for example, when used in combination with polyethylene wax, polyethylene wax is added to 100 parts by weight of the pigment.
Excellent effects are obtained by using 0 to 150 parts by weight and the present dispersant in the range of 1 to 50 parts by weight.

The colorant using the dispersant of the present invention can be obtained by adding a predetermined amount of the dispersant to the pigment and mixing the mixture, but it is preferable to obtain a mixture in which the dispersant is melted and mixed and the pigment is coated with the dispersant. .

The coloring agent created as described above, when coloring the synthetic resin,
It significantly improves the dispersibility of the pigment and gives the molded article a higher degree of coloring (clearness of color development) than when a conventional dispersant is used.

The dispersant of the present invention exhibits an excellent dispersing effect on a wide range of pigments ranging from inorganic pigments to organic pigments. Particularly for organic pigments, the result is remarkably exhibited. Examples of pigments having improved dispersibility include inorganic oxides such as titanium oxide, red iron oxide and ultramarine blue, and organic pigments include phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, quinacridone pigments, and banza yellow.

〔Example〕

 Next, the effects of the present invention will be specifically described with reference to examples.

Example 1 As organic pigments, phthalocyanine blue (Resino Blue; manufactured by Resino Color) was selected from organic pigments, and titanium oxide (anatase type, manufactured by Kishida Chemical) was selected from inorganic pigments. In addition, the mixture is heated and mixed with a Henschel mixer to obtain a colorant.
In a vinyl chloride resin compound containing additives such as a stabilizer, these coloring agents are added such that the pigment component is 0.2 parts by weight when using an organic pigment and 100 parts by weight, and when using an inorganic pigment, the pigment component is 100 parts by weight of the resin. 1 part by weight, mixed well, and kneaded with two rolls at 190 ° C. to obtain a resin molded product. The obtained molded product was further press-molded at 195 ° C. at 130 kg / cm ^{2 to} form a thin film, and then the particle size and the number of pigments dispersed in the thin film molded product were observed with a microscope to evaluate the dispersibility.

In the evaluation, the finer and more uniformly distributed the pigment particles, the better the dispersibility was shown, and the points were evaluated as 5,4,3,2,1 in descending order.

Example 2 For a polyethylene resin (LDPE), the same colorant used in Example 1 was used, and when an organic pigment was used for 100 parts by weight of an organic pigment, the pigment component was 0.2 parts by weight. Is added so that the pigment component becomes 1 part by weight, mixed well, and kneaded with two rolls at 165 ° C. to obtain a resin molded product. The obtained molded product is further 130 kg / c
After press molding at m ² and 170 ° C. to form a thin film, the particle size and the number of pigments dispersed in the thin film molded product were observed with a microscope in the same manner as in Example 1, and dispersed according to the same standard as in Example 1. The sex was evaluated. Table 2 shows the results.

Example 3 Each of the phthalocyanine blue and titanium oxide used in Examples 1 and 2 was added to a melt of a dispersant based on polyethylene wax shown in Table 3, and a well-mixed one was used as a colorant. These colorants were added to the same vinyl chloride resin compound as in Example 1 so that the pigment component was 0.2 parts by weight with respect to 100 parts by weight of the resin, and mixed well.
A thin film molded product was produced in the same manner as in Example 1. Also in the evaluation of dispersibility, the effect of the dispersant of the present invention in a system in combination with a known dispersant, polyethylene wax, was observed in accordance with the evaluation criteria shown in Example 1.

[Effects of the Invention] From Examples 1 and 2, the dispersing effect of metal soap and polyethylene wax, which are known dispersing agents, was evaluated as 3 to 4 and 2, whereas the dispersing agent of the present invention was used. position C ₁₆ -C ₂₀ saturated hydroxy fatty acid glycerol ester is 4-5 having a hydroxyl group, a particularly monoester purity of 90%
Low addition amount (50-60 reduction at high addition amount)
The dispersant of the present invention also shows an excellent effect with an evaluation point of 5, and it can be said that the dispersant of the present invention is a dispersant far exceeding the dispersing effect of the known dispersant.

From Example 3, the evaluation score was 5 by adding about 2% by weight of the dispersant of the present invention to polyethylene wax, which was a known dispersant and had a dispersing effect of 2;
Pigment dispersibility is significantly improved.

In particular, with respect to the dispersion of an organic pigment represented by phthalocyanine blue, in a system using a known dispersant, the dispersibility is inferior to the dispersibility of an inorganic pigment. The dispersant of the present invention exhibits its effectiveness, especially for organic pigments.

Continuation of the front page (56) References JP-A-54-43249 (JP, A) JP-A-3-137131 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08J 3 / 20-3/22

Claims (3)

(57) [Claims] 1. A dispersant for a colorant for a synthetic resin, comprising a glycerol ester of a C ₁₆ -C ₂₀ saturated hydroxy fatty acid having a hydroxyl group at a side position as an active ingredient. 2. The dispersant according to claim 1, wherein the glycerol ester of a C ₁₆ -C ₂₀ saturated hydroxy fatty acid having a hydroxyl group at the side position is glycerin ester of 12-hydroxystearic acid. 3. The monoester content in a glycerol ester of a C ₁₆ -C ₂₀ saturated hydroxy fatty acid having a hydroxyl group at a side position is as follows:
The dispersant according to claim 1, which is 50 to 100%.