CS219845B1 - Mixed pigments for coloring plastics - Google Patents

Abstract

Mixed pigments for coloring plastics such as polyvinyl chloride, polystyrene, polyethylene, polypropylene, etc. The pigments contain by weight 5 to 85% pigment, 10 to 70% calcium carbonate and 5 to 65% monocarboxylic aliphatic

Description

l $ aáte. relates to mixed pigments intended for dyeing particulate matter and comprising pigment, calcium carbonate and a monocarboxylic aliphatic acid,

Plastics, e.g.; polyvinyl chloride, polystyrene, polyethylene, polypropylene, polyester, palyaRrylonitrile and the like are colored with either powdered pigments or pigment preparations containing in addition to pigment auxiliary paints to improve handling during application and to facilitate dispersion of pigment particles in the environment. These systems are subject to strict requirements: the use of pigment preparations, resp. of pigment mixtures, there must be no deterioration of basic coloristic properties such as strength, shade, migration; resistance to weathering and to organic solvents, the dispersibility, which is associated with the energy requirements for incorporation into the dyed medium, must not deteriorate and, finally, the mechanical properties of the polymeric material must not deteriorate. A significant drawback is that excipients limit the possibility of use; pigment preparations or mixtures only for certain applications. Most excipients decompose at low temperatures and thus cannot be used to dye polymers, eg polyolefins, in the mass.

Research has now found that the mixed pigments of the invention, comprising from 5 to 85% by weight pigment, from 10 to 70% calcium carbonate and from 5 to 65% monocarboxylic aliphatic acid having a carbon number of 10 to 26, meet the above requirements.

The mixed pigments contain from 5 to 85% by weight of organic pigment or mixtures of organic pigments, for example, azo condensation pigments (C.

I. Pigment Yellow 93, or 95, or 97, CI Pigment Red 144, or 166, or 220, or 221, CI Pigment Brown 23 et al., Anthraquinone (eg, CI Pigment Red 177), flavamthron (CI Pigment Yellow 24 ), indanthrone (CI Pigment Blue 60), dioxazine pigments (eg CI Pigment Violet 37), phthalocyanine (CI Pigment Blue 15, or 15: 1, or 15: 3, CI Pigment Green 7], tetrachloroisoindoline (CI Pigment Yellow 109) or 110), etc. Inorganic pigments such as titanium white (CI Pigment White 6), carbon black (CI Pigment Black 7), and others, alone or in combination with organic pigments.

The mixed pigments according to the invention contain 10 to 70% by weight of calcium carbonate, preferably precipitated. On the one hand, calcium carbonate dilutes color-rich pigments and, when dispersed in thermoplastics, prevents the formation of firmly bound agglomerates together with other auxiliaries.

The mixed pigments according to the invention comprise 5 to 65% by weight of a monocarboxylic aliphatic acid having a carbon number of 10 to 26, such as undecanoic, lauric, tridecanoic, myristic, pentadecanoic, palmitic, heptadecanoic, stearic, nonadecanoic, arachic, behenic. The use of these acids leads to a significant improvement in dispersibility.

The process for preparing the mixed pigments must be chosen on a case-by-case basis according to the available starting materials. For example, the individual components may be milled together in suitable mills, the components in powder form can only be intimately mixed in a suitable homogenizer, etc. Grinding or homogenization can be carried out both dry and wet.

A wide variety of plastics such as polyvinyl chloride, polystyrene, polyethylene, polypropylene, etc. can be provided with the mixed pigments according to the invention. The color strength, shade and other coloristic properties are satisfactory. Since mixed pigments contain? the coloring problem is simplified, i.e. it is easier to dispense small amounts of pigment into large batches of the meter. The mixed pigments can advantageously be used for dyeing polyolefins in the mass, whereby the pigment disperses better in the polymer compared to the pure pigment powder.

The preparation of the pigments according to the invention and their evaluation are illustrated in the following examples. Percentages · are always by weight.

Example 1

Using TURBULA (type T 2Aj), 16 g of powdered C.I. Pigment Yellow 95, 40 g of precipitated calcium carbonate and 24 grams of stearic acid were homogenized in a 0.5 L container for 3 hours.

The mixed pigment was scored against the original yellow (compared to dyeing with the same pigment content).

219843

Table I

Oil paint

Power 105/100

Shade 1K

Migration

Table I shows that the mixed pigment did not deteriorate the basic coloristic properties.

Evaluation of dispersibility in polyethylene.

Test procedure: 50 g of low-pressure polyethylene granules wetted with 0.1 g of a polyethylene glycol molecular weight preparation of 600 and 0.1 g of pigment (or a mixture containing 0.1 g of pigment) are placed in a 50 ml container. The vessel is allowed to roll on horizontal rollers for 15 minutes. at 6Ů / min. The mixture is then added to a 220 ° C eUruder. Here, the melt is homogenized and a 45 mm wide and 0.5 mm thick tape is extruded from the melt. The amount and size of the non-dispersible particles are evaluated in the tape.

The mixed pigment prepared by the above process does not show any detectable particles in the PE tape, whereas the tape dyed with the original powder pigment contains non-dispersed particles up to 200 µm in size. Thus, the mixed pigment is significantly better dispersed in polyethylene.

Example 2

Following the procedure of Example 1, it was prepared

Polyvinyl chloride Polyethylene subjectively objectively

100/100 101/100 98.6 / 100

1Z 1K - - mixed pigment based on azocondensation red pigment C.I Pigment Red 144 and palmitic acid. The basic colorist assessment was satisfactory. The polyethylene ribbon dyed with the mixed pigment sometimes contained 100 µm particles, the ribbon dyed with the pigment alone often contained 500 μαη particles, again demonstrating the better dispersibility of the mixed pigment.

Example 3

A blend pigment containing 30% phthalicyanine C.I. Pigment Blue 15: 1, 45% calcium carbonate and 25% wt. stearic acid. Colorist evaluation was satisfactory, polyethylene tape did not contain particles detectable by eye, occasionally 50 μιη particles were detected microscopically.

Example 4

Similar results, as in the previous examples, were obtained with mixtures containing C.I. Pigment Red 177, C.I. Pigment Blue 15: 1, C.I. Pigment White 6 and lauric, myristic and behenic acids.

Claims (4)

Subject Mixed pigments for coloring plastics, characterized in that they contain 5 to 85% by weight of pigment, 10 to 70% of calcium carbonate and 5 to 65% of monocarboxylic aliphatic acid having a carbon number of 10 to 26. 2. Mixed pigment according to claim 1, characterized in that it contains an organic pigment or a mixture of organic pigments as pigment. vynalezu 3. Mixed pigment according to claim 1, characterized in that it contains an inorganic pigment or a mixture of inorganic pigments as pigment. 4. Mixed pigment according to claim 1, characterized in that it contains a mixture of organic and inorganic pigments as pigment.