CS245096B1 - A method of surface treatment of pigments for coloring polyolefins in the mass - Google Patents

Abstract

The solution relates to a method of surface treatment of pigments for dyeing polyolefins in bulk. The surface treatment of pigments according to the solution consists in homogenizing the pigment after grinding in an aqueous medium with an organic dispersant based on glyceride or amides of carboxylic acids with a carbon number of Cs to C20 or liquid polyolefins, or a mixture thereof, without or in the presence of powdered polyolefin. With the addition of monovalent metal chloride, the pigment is separated, for example by filtration, and after washing is dried at a temperature of 60°C, preferably under vacuum.

Description

pigments for coloring polyolefins in the mass.

The surface treatment of the pigments according to the invention consists in homogenizing the pigment after aqueous grinding with an organic dispersant based on glyceride or carboxylic acid amides having a carbon number of C8 to C20 or liquid polyolefins, or a mixture thereof, in the presence or absence of polyolefin powder. With the addition of monovalent metal chloride, the pigment is separated, for example, by filtration, and after washing it is dried at 60 [deg.] C., preferably under vacuum.

248096

The present invention relates to a method for coating pigments for coloring polyolefins in a mass.

The color strength of the pigments used for dyeing polymers and articles thereof depends mainly on the quality of the pigments, in particular to make them more dispersible in polyolefins. A high degree of dispersion of the pigments in the polyolefins and hence an increase in the coloring capacity of the pigments can be achieved by the use of suitable modifiers which, in addition to increasing the degree of dispersity, generally improve the processing properties of the pigment concentrate and the dyed polymer (AO Nos. Despite the use of dispersants, it is not possible to obtain an optimum degree of pigment dispersion by commercially available polymer dispersions. This can only be achieved by a special grinding process in a medium of low viscosity liquids. Such procedures are described in the patent literature, for example, German Pat. no. 126,136, US Pat. no.

755 244. The principle of these processes consists in grinding pigments in an aqueous medium with or without the presence of a polyolefin and soluble with the addition of a special dispersant; in water, depending on the pH as the organic phase, which after grinding together with the pigment is precipitated by the action of a lower temperature and a change in the pH of the environment (NSR Pat. 126 136, US Pat.

According to the invention, the surface treatment of polyolefin coloring pigments in a mass according to the invention consists in homogenizing the pigment after grinding in an aqueous medium with an organic dispersant based on glyceride or C5 -C20 carboxylic acid amide or liquid polyolefins or mixtures thereof without or in the presence of polyolefin powder. at 20 to 100 ° C. After the monovalent cation chloride is added to the dispersion, the treated pigment is separated and dried.

Ionogenic or non-ionic substances, for example polyoxyalkylene glycols, resp. their water-soluble derivatives in a concentration of up to 30% by weight; The pigment concentration when grinding in an aqueous medium is up to 40% w / w. The organic dispersant based on glycerides or carboxylic acid amides or low molecular weight polyolefin has a melting point of 20 to 80 ° C and is added in an amount of up to 150 wt. of pigment, preferably 30 to 50% of pigment.

The surface-treated pigment is further used for the preparation of concentrated color dispersions or for direct dyeing of polyolefins in the mass.

Advantages of the process for preparing the pre-dispersed pigments include the formation of pigment granules below 1 mm in diameter with a significant reduction in dustiness and a high degree of pre-dispersibility of the pigment with consequent increase in its coloring strength - in particular difficult dispersible pigments.

The examples below illustrate the subject matter of the invention.

Example 1

100 parts by weight Pigment yellow 95 in the form of a filter cake containing 20 parts pure pigment and 80 parts water is diluted in a planetary mixer with an additional 100 parts water containing 20 wt. polyoxyethylene glycol 600 and 6,000 in a 1: 1 ratio. After homogenization, the dispersion is transferred and ground in a continuously operating bead mill at 2000 rpm and 70 ° C by 5-fold passage. The dispersion is then transferred to a high speed homogenizer and 20 parts of stearic acid monoglyceride are added. The mixture is homogenized for 10 minutes and then 100 parts cold water containing 10 parts NaCl are added under stirring. In such dispersions, fine granules of surface-treated and aggregated pigment are formed in the dispersions. These are separated from the water by filtration under vacuum, washed with water and dried at 60 ^DEG C. to constant weight, preferably under vacuum.

Example 2 parts by weight of pigment red 147 is mixed with 180 parts of water containing 20 wt. polyoxyethylene glycol 600 ester and oleic acid. After homogenization, the dispersion was ground in a continuous mill for 4 hours. After this time, the dispersion is transferred to a high speed homogenizer and heated to 70 ° C. 10 parts of stearic acid glyceride and 10 parts of polypropylene oil having an average molecular weight of 1000 are added to the dispersions. The dispersion is homogenized at 2,000 rpm at 70 ^° C and then cooled by adding another 200 parts of cold water containing 10 parts of NaCl. The resulting dispersion was filtered off, washed with water and dried to constant weight at 60 ° C.

Example 3

30 parts of oleic acid monoglyceride are added to 50 parts of polyethylene powder and homogenized on a rapid mixer at 70 ° C. 700 parts of water and 100 parts of yellow 145 ground pigment filter cake containing 50% water are added to the mixture. The mixture was re-homogenized on a rapid mixer at 70 ° C for 10 minutes. Then 20 parts of KCl are added under stirring and cooling. The mixture was filtered and dried at 70 ° C under vacuum.

Example 4

Κ 50 parts of degraded polypropylene powder with a flow index of 150 g / 10 min. 30 parts of a 7: 1 stearic acid monoglyceride / polypropylene oil mixture are added and homogenized at 70 ° C. 50 parts of pure ground red 147 pigment are added as a 40% aqueous paste and 500 parts of 70 ° C warm water. The mixture was homogenized on a rapid mixer for 6 minutes. An additional 200 parts of a 5% aqueous NaCl solution was added with stirring. The pre-dispersed pigment is filtered, washed and dried at 70 ° C.

Example 5

The alko process of Example 1, except that after grinding the pigment in a pearl mill, 20 parts of stearic diamide and ethylenediamine are dispersed. After homogenization in a high speed mixer for 10 minutes at 70 ^° C and subsequent addition of cold water, the packed pigment is separated on a centrifuge. The centrifuged pigment is dried under constant agitation with hot air at 50 ^° C.

example

The procedure as in Example 1 except that after grinding the black 7 pigment in a bead mill, 40 parts of stearic acid glyceride and 20 parts of technical paraffin are added to the dispersion. After homogenization in a high speed mixer for 15 minutes at 70 ° C and cooling of the dispersion by addition of cold water containing 10 parts of NFUC1, a fine, well filterable precipitate of pigment was obtained, which after filtration was washed with water and dried at 50 ^{° C.} C under vacuum.

Example 7

Pigment red 147 is treated according to the alko process of Example 4, except that 50 parts of 70 ° C water are added to a mixture of polypropylene powder, stearic acid monoglyceride, polypropylene oil and pigment paste. The mixture was homogenized on a rapid mixer for 12 minutes and dried.

Increasing the dyeing strength (RFS) of concentrates prepared from treated pigments over concentrates produced by conventional methods, determined by measuring the remission of fibers made from said concentrates.

RFS concentrates of treated pigment versus conventional

Number of concentrate from the same pigment examples

131%

102%

125%

135%

128%

108%

105%

SUBJECT

Claims (1)

Process for the surface treatment of pigments for coloring polyolefins in a mass, characterized in that, after grinding in an aqueous medium, the pigment is homogenized with a carboxylic acid glyceride or amide having a carbon number of Ca to C20 or cavalous polyolefin or mixtures thereof, in the presence or absence of polyolefin powder. 20 DEG-100 DEG C. and after the monovalent cation chloride is added to the dispersion, the treated pigment is separated and dried.