JPS5934738B2 - granular pigment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a granular pigment for thermoplastic resins, particularly a granular pigment suitable for coloring ABS resins.

3. ABS resin will be described below as an example, but the invention is not limited thereto.

Conventionally, ABS resins have been generally colored by a color pellet method in which a mixture of resin and colorant is kneaded in advance using an extruder. As a cost reduction measure, there is a demand for a so-called self-coloring molding method in which a coloring agent and a resin are mixed during molding to perform coloring molding. In general, colorants have difficulty dispersing in ABS resins, and various methods have been proposed for coloring them. For example (1
) A dry color method in which a mixture of ABS resin and dry color is directly molded, (2) a liquid color method in which the pigment is dispersed in a liquid medium (a granular color method in which the three pigments are granulated into granules to make them easily disintegrating) (4) There is a masterbatch color method in which pigments are dispersed in ABS resin in advance at a high concentration.

However, (1) causes deterioration of the working environment due to color scattering and makes it difficult to change the color, (2) causes deterioration of physical properties as the liquid medium remains in the molded product, and (3) causes deterioration of physical properties during molding. (4) It is easy to cause poor biting of the resin to be colored, and it is difficult to break the granules, resulting in poor appearance such as color unevenness, layer peeling, and flash due to insufficient kneading. Since it is subjected to thermal history, it has disadvantages such as deterioration of its physical properties.

The present invention solves these drawbacks, and by forming a molten mixture of pigments with a higher fatty acid and a specific fatty acid amide into granules, it is inexpensive and easy to change the color, and the resin itself does not undergo heat history. The purpose is to provide an excellent pigment for molding resin that is completely free of color unevenness.

That is, the present invention uses 25 to 75% by weight of pigment and 75 to 75% by weight of dispersant.
25% by weight, and the dispersing agent consists of a metal salt of a higher fatty acid and methylene bis stearamide or ethylene bis stearamide, and the ratio by weight is 5 to 95:95 to 5. It is a particulate pigment.

The present invention will be further explained in detail below.

The granular pigment of the present invention is made of thermoplastic resins such as ABS resins, vinyl chloride resins, ethylene resins, propylene resins,
It can be used for styrene resins, polycarbonate resins, polyamide resins, diene resins, ester resins, etc., and is particularly advantageous for ABS resins.

Furthermore, specific examples of the above-mentioned ABS resin include acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-butadiene-styrene-d-methylstyrene copolymer resin, acrylonitrile-butadiene-styrene-
Examples include, but are not limited to, acrylic ester copolymer resins, acrylonitrile-butadiene-styrene-d-methylstyrene-acrylic ester copolymer resins, and the like.

In the present invention, pigment means both known dyes and pigments, such as carbon black, titanium oxide, zinc oxide, iron oxide, calcium carbonate, silica,
Pigments made of inorganic substances such as chromium oxide and talc Organic pigments and dyes such as phthalocyanine, anthraquinone, quinacridone, azo, quinophthalone, perinone, and perylene, and are generally used for thermoplastic resins. It's fine as long as it's available.

Next, the ratio of pigment to dispersant is 25 to 75 to 7 by weight.
5 to 25, and if the blending ratio of the dispersant is larger than this, the amount of the granular pigment composition added to the resin will increase, which is not economical.On the other hand, if it is smaller, it will be difficult to granulate the colorant. .

Further, the present invention is characterized by the type and blending ratio of the dispersant, and the dispersant consists of a higher fatty acid metal salt and a specific fatty acid amide.

Moreover, the weight ratio is 5 to 95 to 95 to 5.
The reason for this specification is that when a higher fatty acid metal salt is used alone or in a small proportion, the resin to be colored tends to be poorly penetrated during molding, resulting in poor appearance such as flashing and layer peeling due to insufficient kneading. Furthermore, if the fatty acid amide is used alone or in a small proportion, the biting is good, but color unevenness occurs, which is not preferable.

Specific examples of higher fatty acid metal salts include lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid,
Examples include calcium salts, barium salts, aluminum salts, zinc salts, and magnesium salts of oleic acid.
More than one species can be used.

Further, the fatty acid amide used in the present invention is selected from the group of methylene bis stearamide and ethylene bis stearamide, and one or more of these is used.

The present invention is characterized by the type and content of the pigment dispersant, and the essential components constituting the granular pigment are the pigment and the dispersant, but other additives may be added as necessary, such as ultraviolet absorbers and Antioxidants, flame retardants, antistatic agents, etc. can be added.

The product of the present invention can be manufactured by, for example, mixing and agitating a dye or pigment and a dispersant using a tumbler or a high-speed stirrer, and utilizing the heat generated to form a melt into granules, or by mixing the above-mentioned raw materials. Examples include, but are not limited to, a method in which the material is melted in the presence of an inert gas at a temperature of about 40°C below the melting point of the dispersant, cooled and pulverized, as long as it is mixed and granulated. good. EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Example 1 50 parts by weight of carbon black and 50 parts by weight of the dispersant shown in Table 1
Parts by weight are stirred and mixed for 2 minutes using a pencil mixer, taken out from the mixer, heated in an inert gas at a temperature approximately 40°C higher than the melting point of the dispersant, melted, cooled, and pulverized to obtain particles with a particle size of 0.1 to It was made into a 3 mm granular pigment.

1 part by weight of this granular pigment and 100 parts by weight of "Denka ABSGR-200" manufactured by Denki Kagaku Co., Ltd. were stirred for 900 r using a Mitsui Miike Seisakusho FM-20 type pencil mixer.
Mixed for 2 minutes at pm.

Next, a plate of 80 x 50 mm was molded using an injection molding machine manufactured by Nissei Co., Ltd. under the trade name "Nissei TS-50" (screw 1 L/T = 18, full flight type screw 1).
The plate appearance and layer peeling were examined.

The results are shown in Table 1. Example 2 A granular pigment was produced in the same manner as in Example 1 except that the dispersants and their proportions shown in Table 2 were changed.

Next, the same procedure as in Example 1 was carried out except that "Denka ABSQF" manufactured by Denki Kagaku Co., Ltd. was used. These results are the second
Shown in the table. Molded products made of granular pigments in which the amount of zinc stearate in the dispersant exceeds 95% by weight exhibit layer peeling,
Molded products made of granular pigments containing less than 5% by weight of granular pigments exhibit color unevenness and are inferior.Molded products made of granular pigments containing a dispersant with a blending ratio of zinc stearate/methylene bisstearamide of 5/95 to 95/5. The molded product had the same good appearance as the molded product made of pigment-free QF.

○...Good condition, no flashing.

△・・・・・・There is hairline-like silver in the flow direction of the resin.

×...The flash portion is noticeable. (3) Layer peelability (DIS value) Plate (3 mm thick) is 8 mm x 20 m from two directions: the flow direction of the resin and the direction perpendicular to the flow.
Six small pieces of m were cut out, and the die stud impact strength was measured.

The DiS value was determined from the following equation, with the average values of the die-stud impact strength in the resin flow direction and the right angle direction being XT and XY, respectively.

DiS value = Y/Also, the closer the TDiS value is to 1.0, the more directional the impact strength is and it can be judged that the resin is homogeneous without layer peeling.

(4) Peeling test A plate with a tab-shaped gate was used, and after the tab portion was bent, the plate was peeled off in the flow direction of the resin, and the peeled area was visually judged.

Claims (1)

[Claims] 1 A mixture of 25 to 75% by weight of a pigment and 75 to 25% by weight of a dispersant, in which the dispersant consists of a metal salt of a higher fatty acid and methylene bisstearamide or ethylene bisstearamide, and 3 The ratio is 5~ by weight
95: Particulate pigment having a ratio of 95 to 5.