JPS58198534A - Highly concentrated plastic colorant - Google Patents

Abstract

PURPOSE:To provide the titled colorant which can be diluted at least 10 times its own weight, by blending a coloring pigment with a resin compsn. contg. a specified modified polyolefin as a component. CONSTITUTION:A resin compsn. contg. at least 10% modified polyolefin having a melt index of 3 or above modified with an unsaturated carboxylic acid (derivative) such as itaconic acid or maleic anhydride (as other resin components, resins of the same kind as the modified polyolefin being preferred) is used. A coloring pigment at a high concn. is dry-blended with the above resin compsn. The blend is melt-kneaded by using a twin-screw extruder or a Banbury mixer and granulated to form a highly concentrated plastic colorant.

Description

DETAILED DESCRIPTION OF THE INVENTION In order to obtain a uniformly colored plastic molded article with excellent dispersion and smelting properties, the present invention uses (r) a high-IXI plastic coloring material. The present invention relates to obtaining a colored plastic molded article that is more economical as a result, since it has a source-saving and energy-saving effect.

Specifically, in order to obtain a plastic coloring material that can be diluted to 10 times its weight or more, 10% or more of the resin component in the coloring material is composed of an unsaturated carboxylic acid such as maleic anhydride or itaconic acid or a derivative thereof. The present invention relates to a high-density plastic coloring material composed of a resin component made of a modified polyolefin and in which the melt index (MI) of the modified polyolefin is in the range of 3 or more.

Traditionally, colored molded products such as polyethylene, polypropylene, and polystyrene made by injection molding or blow molding have been prepared by adding powdered dry color or coloring material to the resin used in advance, before starting molding. Blend appropriate amount of grain pellets and shape. Recently, there has been a tendency to use automatic measuring and mixing machines for labor saving and rationalization, and for this reason, the latter type of masterbatch is often used.

Normally, masterbatches contain high concentrations of colorants and are used diluted, but for colored pigments such as white threads and pale neutral colors,
Extender pigments such as titanium oxide, calcium carbonate, synthetic mica, and aluminum hydroxide are commonly used. These components are contained in larger amounts than other organic pigments, and the higher the concentration of the master bunch, the more pigment components there are, and as a result, the amount of extender pigments increases. In this case, extender pigments such as titanium oxide, calcium carbonate, and synthetic mica have a large cohesive force, and the higher the concentration, the worse the dispersibility becomes. In conventional white yarn and neutral color masterbatches, the pigment component in the resin is limited to about 20 parts at most, and the dilution ratio is the maximum dilution ratio. If it exceeds this range, the dispersibility of the masterbatch will be poor, and as a result, the appearance of the molded product, such as uneven coloring, weld marks, and flow marks, will be significantly reduced. As a countermeasure for this, methods are being taken to improve the dispersion and kneading properties by improving the design of the plasticizer of plasticizing equipment of plastic processing machines such as injection molding machines and blow molding machines. However, this method is not a basic solution if the pace masterbatch itself has poor dispersibility (・.

The high-concentration plastic colorant according to the present invention can be diluted to a higher degree even with such difficult-to-disperse white threads and intermediate color pigments, and even with a masterbatch with a maximum dilution ratio of 100 times, it is possible to achieve good dispersion and uniform coloring, resulting in good dispersion and uniform coloring. Since the amount of masterbatch used could be reduced within a certain range, the total cost could be reduced, resulting in more economical effects.

The present invention will be explained in detail below.

The high-concentration plastic coloring material according to the present invention prevents the agglomeration of extender pigments, which causes poor dispersion when extender pigments such as titanium oxide are contained in high concentrations in the resin component of the coloring material, and maintains a uniform dispersion state. In addition to metal soaps such as lead stearate and waxes such as low-molecular-weight polyethylene, which have traditionally been used as dispersants, maleic anhydride, unsaturated carboxylic acids such as itaconic acid, or their derivatives are used as dispersants. 10% or more of the graft-modified modified polyolefin is added to the resin component in the coloring material, and the melt index (MI) of the modified polyolefin is
) is a highly kneaded, high-concentration plastic coloring material composed of a resin component in a range of 5 or more. The concentration of the modified polyolefin in the resin component of the coloring material may be about 10% when the dilution ratio is about 20.
When doubled, it increases to nearly 100%. Other resin components other than the modified polyolefin are the same as the resin used for molding,
For example, polyethylene, polystyrene, polypropylene, etc. In addition, it is preferable that the resin used in molding and the modified polyolefin be relatively similar. If the molding resin is polyethylene, it is preferable to use modified polyethylene as the modified polyolefin, and if the molding resin is polypropylene, it is preferred to use modified polypropylene as the modified polyolefin. Better~·.

Further, in this case, a modified polyolefin σ) having a melt index (MI) of 5 or more and excellent fluidity is selected. Resins with a molecular weight of 6 or less have little effect on improving dispersion.

In other words, the better the fluidity, the better the pigment dispersion. The modified polyolefin is preferably added in the form of a powder. The manufacturing method of high concentration plastic coloring material is as follows:
The pigment and the modified polyolefin are mixed in advance by tri-blending, and then sufficiently melt-blended and granulated using a high-performance kneading machine such as a twin-screw extruder or a remixer.

The highly concentrated plastic coloring material thus obtained can be diluted to more than 10 times its weight, and can be diluted up to 1 QO times its weight. In this case, the amount of modified polyolefin used as a dispersion aid increases as the pigment concentration increases. The material cost of the masterbatch obtained in this way increases as the amount of modified polyolefin used increases, but conversely, the dilution ratio increases, resulting in a decrease in the total cost as a coloring material. Compared to the conventional masterbatch (Comparative Example 2), it has an energy-saving and resource-saving effect, so a more economical colored plastic molded product can be obtained.

<Example 1> 100 parts of a colored pigment, which is a mixture of an organic pigment and an extender pigment at a ratio of 1:1, and 5 parts of lead stearate were thoroughly stirred,
Further, 200 parts of powdered modified polyethylene (maleic anhydride graft modified polyethylene, M1=10) was added and mixed and stirred. These powder mixtures were melt-kneaded in a co-rotating twin-screw extruder to obtain granulated pellets (masterbatch). This masterbatch was processed into high-density polyethylene (manufactured by Showa Denko, 5hovex 6002 B, M
I = 0.3, density = 0.94) 100 parts and 1 part of master punch were blended (dilution ratio: 100 times) and supplied to a blow molding machine. The resulting molded product was a uniformly colored product with good dispersion.

<Example 2> 50 parts of a colored pigment prepared by mixing an organic pigment and an extender pigment at a ratio of 1:1, stearic acid, and 2.5 parts of lead were thoroughly mixed and stirred, and then powdered modified polyethylene (MI-10) was added. '%
Add 150 parts and mix and stir. High-density polyethylene (Sho I) manufactured by Denko, 5hovex was added to these powder mixtures.
6002 B, MI = 0.3) were blended and fed to a co-rotating twin-screw extruder to obtain a master patch. This master bag high-density polyethylene (manufactured by Showa Denko, Sb OV e x6002
B, MI=O4) ratio of 1 part masterbatch to 50 parts (
The mixture was blended at a dilution ratio of 50 times) and supplied to a blow molding machine. The molded product obtained was a colored product with good dispersion.

<Comparative Example 1> 50 parts of a coloring pigment, which is a mixture of an organic pigment and an extender pigment at a ratio of 1:1, and 25 parts of lead stearate were thoroughly mixed and stirred, and then high-density polyethylene (manufactured by Showa Denko, 5hovex) was thoroughly mixed and stirred.
200 parts of 6002 parts (1M engineering = O filter, density - 094) were mixed and stirred, and the mixture was used in a co-rotating twin-screw extruder to obtain a master bar. This master bunch was made of high-density polyethylene (manufactured by Showa Denko, 5hovex 60
02B) 50 parts of the masterbatch and 1 part of the masterbatch were blended (dilution ratio: 50 times) and supplied to a blow molding machine.

The resulting molded product had poor dispersion and had wood grain flow marks, making it impossible to obtain a uniformly colored product.

Comparative Example 2> 10 parts of a colored pigment, which is a mixture of an organic pigment and an extender pigment in a ratio of 1=1, and 05 parts of curved lead stearate were thoroughly mixed and stirred, and then high-density polyethylene (manufactured by Showo Nichidenko, 5hovex) was thoroughly mixed and stirred.
6002 B, MI = 0.3, density = 0.94)
Mix and stir 200 parts, and rotate these mixtures in the same direction 2
Masterbatch pellets 7)Y were obtained using a screw extruder. This masterbatch was applied to high-density polyethylene (manufactured by Showa Denko: Eb).
ovex6002B) 10 parts 1c master batch 1 part (dilution ratio 10 times) was blended and supplied to a blow molding machine. The resulting molded product could not have uniform dispersion.

patent applicant Toppan Printing Co., Ltd.

Claims (1)

[Claims] (10% or more of the resin component consists of a modified polyolefin modified with an unsaturated carboxylic acid such as maleic anhydride or itaconic acid or a derivative thereof, and the modified polyolefin has a melt index (
A highly concentrated plastic layer coloring material composed of wood components in the range of Ml) or above σ).