CS223671B1 - Method of dying the plastic substances by pigments under utilization of dispersants - Google Patents

Description

The present invention relates to a process for dyeing plastic materials with organic or inorganic pigments and filling them with fillers using dispersants of the copolymers type alkoxypolypropox-polyetox-amers which make it possible to achieve an extremely high degree of dispersion of the pigment or filler and its even distribution throughout the plastic.

Pigments are organic or inorganic powders practically insoluble in the dyed plastic material. Due to the thermal thermal stresses during processing, it is possible that some organic pigments will at least partially dissolve. Pigments consist of particles whose size increases in order: primary cleaners (single crystals), aggregates and agglomerates. The color efficiency of pigments increases with particle size. The dispersion of the pigment is, in particular, crushing, removing agglomerates. The dispersant increases the wetting rate of the agglomerates, causes them to be crushed into aggregates and primary particles, and ensures the stability of the fine dispersion. The reduction of the melting rate of the plastic material further supports the dispersion process.

The plastics are mainly dyed in two processes, either in the mass of their production or in the mass of their powder or granulate. The third method, the surface coloring of finished plastic products, is rarer. Usually, the pigment or pigment preparation is dry mixed with the powder or granulate of the plastics material in agitators of various types (drum, fluid mixer and subsequently processed in extruders or spray machines. The plastics material can also be colored by adding commercially available pigment preparations or prepared on site, into the processing machine without pre-mixing.

The most important inorganic pigments are T1O2 - pigments (especially rutile) and zinc sulphide pigments with different ZnS content up to 100% (less effective than T1O2 pigments) for white coloring, iron and chromium oxide pigments (rye, red, brown, black and green types) ), extremely stable and practically suitable for all plastics suitable mixed phase pigments of different color tones, such as Ni-Sb-Ti, Cr-Sb-Ti pigments, mixed phase pigments of oxides of Fe, Cr and Cu, cadmium pigments of CdS or Cd-Snlide (selenide, chromate mixed phase pigments of the composition Pb (Cr, SJO4 and Pb (Cr, Mo, SJO4). A pigment can also be counted as a filler if its refractive index in a certain environment is greater than 1.7. Known filler types are powder chalks and various types of calcium carbonates, Ca-Mg-carbonates (dolomites), silicates, barium sulphates and others.

Organic pigments for plastics are characterized by high color intensity, brilliance and purity of color tone. For grit and increased technical demands such as. the high thermal and migratory stability, wettability and dispersibility, the choice of a large number of organic pigments narrows considerably and a suitable pigment must be sought and tested. In order to facilitate this selection, according to the aforementioned indicators, organic pigments are generally suitable for the plastic sector, summarized in special assortments, in particular large pigment manufacturers.

The dispersants of the present invention have a number of advantages as set forth below. They differ in composition and application from known dispersants. Narp. U.S. Pat. No. 2,523,096 to use a defined mixture of a non-ionic polyether-based emulsifier with a mineral oil boiling in the range of from 140:10 to 310 ° C in a weight ratio between 35:65 and 5:95, wherein the emulsifier is an alkoxylation product of a fatty alcohol, fatty acid or fatty acid amide. 7 to 30 C-atoms or an alkylphenol containing C4-C12 alkyl with C2-C4 alkylene oxide in a statistical average of 3 to 30 mol / mol. The object of DOS 2,801,315 is a pigment preparation composition comprising a pigment, a nonionic surfactant and a copolymer of 80,000 to 60,000 average molecular weight consisting of 90 to 50% alpha-methylstyrene and 10 to 50% acrylonitrile, the surfactant being an undefined ethylene oxide adduct; and / or propylene oxide on long chain or cycloaliphatic alcohols, fatty acid amines or alkylphenols.

The dispersants of the present invention promote the wettability and dispersibility of the organic pigments and allow a very rapid process to prepare a fine and stable dispersion.

The dispersants of the present invention are suitable for dyeing with pigments or pigment preparations as well as plastics having high operating temperatures in the range of 200-300 ° C. They are particularly suitable for high and low pressure polyethylene, polypropylene, polystyrene and styrene mixed polymerizates, polyvinyl chloride and its copolymers, phenolic and polyester resins, urea and melamine resins, polymethacrylates, polyamides and others.

The dispersants of the present invention are copolymers of alkoxy-polypropox-polyetox-amers (alkoxy-polyethylene oxide-polypropylene oxide copolymers; alkyl-polyethylene-polypropylene glycols) of the general formula:

R - (O - CH - CH 2), CH 3 - (O - CH 2 - CH 2) _{y -} OH, where it is

R - alkyl of higher fatty alcohol, preferably C4 to C12, x average number of propylene oxide molecules per mole of polypropox 4 to 40, preferably 4 to 24, y - average number of ethylene oxide molecules per mole of polyetox 2 to 20, preferably 4 to 12 .

These high-performance dispersants ensure perfect application of the coloring effect of the pigment such as color saturation, color tone and its stability, gloss, hiding power, and secondly improve the production economy by significantly reducing pigment consumption by up to one third or more compared to the known or using known dispersants which are less effective.

The properties of the dispersants according to the invention are particularly valuable, in particular for the film sector, which places such high demands on the fineness of pigment disintegration that only special pigment preparations which are characterized by a particularly high degree of dispersion of the pigments contained can satisfy them.

A further advantage of the dispersants according to the invention is the possibility of influencing the chemical structure of their hydrophilic properties, which allow easy and rapid cleaning of water machinery and containers coming into contact with color mixtures and pigment preparations. It is known that pure polyethylene glycols HjCzHHíOjmHH compete to a molecular weight of about 600 viscous liquids and above that waxy. They dissolve in water perfectly at room temperature. Polypropylene glycols HO (C 3 H 6 O) _n H are liquid. By mixing the polymerization of the two alkylene oxides to form combinations of the hydrophilic polyethylene oxide with the hydrophobic chains of the polypropylene oxide, as well as the polyalkoxilization of fatty alcohols, compounds with specific properties such as e.g. with a solubility in water or in organic liquids, with a capillary activity, viscosity, chemical stability, etc. ^first

An advantage of the dispersants of the present invention is also that, due to their high dispersing effect, no visible grains of pigment are present or adhered to the walls of the machinery and containers due to their high dispersing effect and allow sharp, very rapid transition to products from a new blend of another color. , with very little production of a transient color waste product, without the need to interrupt production and clean the production equipment.

Another advantage of the dispersants according to the invention is that they remain incorporated in the polymer of the plastic and only to a minor extent influence the extracted content from the polymeric products with the prescribed extracting agents.

The dispersants according to the invention can be used for the preparation of color blends at the place of manufacture of colored plastics as well as for the preparation of long-lasting pigment preparations (concentrates) which can be conventional market products in the form of grandiose, powders, pastes, viscous liquids in dispersed form. These preparations may contain 1 wt. and more, preferably about 10 to 70% by weight, of pigment in dispersed form, and comprise, in addition to the pigment, a dispersant and may further comprise a plastic to be colored, wetting agents, other auxiliaries or mixtures thereof which are compatible or miscible by the plastic.

The direct use of dispersants at the place of manufacture of colored plastic products such as granules, powders, foils, moldings, castings, etc., is done by mixing the pigment with the dispersant, optionally with the prescribed additives such as thermo-oxidizing stabilizers, glidants, anti-UV -stabilizers, with plasticizers and fillers and in the form of a liquid mixture or paste is added by hatching or continuously by pump), depending on the type of processing machine, in a specified proportion to the plastic, through a pipe extending to the bottom of the hopper for dispensing granulate, powder or melt a plastics material placed on a processing machine such as a strekolis, an extrusion screw and the like.

The use of the dispersants according to the invention makes it possible to achieve substantial energy savings. Due to the high dispersing effect and the high dispersing speed of these dispersants, mixtures of dispersants and pigments, and possibly other on-site auxiliaries, can be used in the manufacture of colored plastics, thereby avoiding the preparation of colored granules, powders, pastes, which brings energy savings. It also saves on storage and transport capacities and saves on the storage of raw materials and materials.

The dispersants of the invention improve the sliding, antistatic and antiblocking properties of films and other articles. They also reduce the power input required to drive processing machines.

A particular advantage of the dispersants of the present invention is their suitability for use in addition to coloring plastics as well as in the preparation of filled plastics dyed or natural fillers such as powder chalk, especially radiation absorbing fillers, flame retardants, foaming agents, and the like. The procedure is similar to that used for dyeing plastics with pigments, i.e.. j. the fillers are mixed with the dispersant and treated in the form of a liquid mixture or paste with a polymer of the plastic. The dispersants ensure a high degree of dispersion of the fillers, their even distribution and the easy and homogeneous mixing of these mixtures with the plastic.

Process for dyeing plastics with organic and inorganic pigments and for filling color and natural plastics with fillers using the dispersants of the present invention and known processes for making color blends, pigment preparations, filled dyed or natural plastics and color products in the form of granules, powders, films, moldings, castings and the like. characterized in that 0.02 to 99.0 wt. a dispersant, wherein the addition of the dispersant to the plastics is at least 0.02% by weight, preferably in the range of 0.2 to 2.0% by weight, based on the plastic, the content of the dispersant in color mixtures and pigment preparations is at most 99, 0% by weight, preferably in the range of 30.0 to 90.0% by weight. and when filling colored and natural plastic materials, the dispersant addition is at most 99.0% by weight, preferably in the range of 30.0 to 90.0% by weight. and a difference of up to 100 wt. represents a filler. The use of the dispersants of the present invention is illustrated by the following non-limiting examples.

Example 1

In a conventional mixer at room temperature, a mixture of 1.2 kg TiO 2 (Bayer Titan RFKD) and 0.8 kg 2-ethylhexyl-polypropox-polyethoxomer is mixed, with a mole of polypropox containing an average of 10 propylene oxide molecules and a mole of polyetox an average of 4 ethylene oxide molecules. , for 5 to 10 minutes until a homogeneous liquid dispersion mixture is formed.

The prepared mixture is dosed in a weight ratio to a 1:50 granulated high pressure polyethylene before the colorless polymer enters the screw, into the bottom of the hopper into which said polyethylene granulate is placed, on a continuous screw auger, where the extruded molten mixture temperature reaches 220 C.

A screw with a 20: 1 ratio in length to diameter supplied material to the exhaust head, from which a 0.3 mm thick white color film with completely uniformly distributed pigment was obtained, without any visible grains. The determined increased extract (compared to the plastic raw material alone) was 0.16% by weight.

For dispensing the liquid dispersion, a peristaltic pump provided with speed control to a co-operating screw or other continuously operating processing machine is preferably used. For dosing into periodically operating processing machines, such as e.g. injection molding machines, the pump drive is provided with a switch coupled to a valve controlling the melt output to the mold.

Example 2

A homogeneous liquid mixture consisting of 1 kg of Bayer Titan RFKD pigment and 1 kg of 2-ethylhexylpolypropox-polyethoxy-amer was prepared according to the procedure and conditions as in Example 1, whose mole of polypropox consisted on average of 8 molecules of polypropylene and mole of polyetox on average 4 molecules of ethylene oxide. .

The prepared homogeneous color mixture was treated with granular high pressure polyethylene at a weight ratio of 1: 60 on a 0.3 mm thick film on the apparatus and under the conditions as in Example 1. The produced film had sufficient saturation (less than Ex. 1) white color, completely uniformly distributed pigment, without any visible grain. Increased extract 0.22 wt. Example 3

A high pressure polyethylene film was prepared according to the conditions and apparatus as in Example 2, except that 2-ethylhexyl-polypropox-polyetox-amer was used as dispersant, whose mole of polypropox contained on average 8 molecules of propylene oxide and mole of polyetox on average 8 ethylene oxide molecules. The appearance of the film produced was similar to that of Example 2. The increased extract was 0.05% w / w.

Example 4

A high pressure polyethylene film was prepared according to the conditions and apparatus of Example 2 except that 2-ethylhexyl-polypropox-polyetox-amer was used as dispersant, whose mole of polypropox contained on average 16 molecules of propylene oxide and mole of polyetox on average 4. ethylene oxide molecules. The appearance of the film produced was essentially the same as that of Example 2. The increased extract was 0.08% by weight. Example 5

A high pressure polyethylene film was prepared using the procedure and conditions as in Example 1 except that 0.25 kg of Chromphtal Gelb 66 was used, 1 kg of 2-ethylhexyl-polypropox-polyetox-amine as in Example 2 and the ratio of the pigment-dispersant color mixture to the high-pressure polyethylene was 1:80. A clear yellow color film with a constant tone, with a completely homogeneously dispersed pigment, without visible grains, was obtained. Determined increased extract 0.19 wt.

Example 6

A film was prepared according to the conditions and apparatus of Example 5 except that Chromphtal Roth BR was used as the pigment. The produced film of a deep red color, with a constant tone, with a completely homogeneously dispersed pigment was free of visible grains of pigment. Increased extract 0.15% w / w.

Example 7

Using the procedure and conditions of the apparatus as in Example 5, a film was prepared as in Example 5, except that Chromphtal Grun 67 in an amount of 0.30 kg was used as a pigment and the ratio of color pigment / dispersant to high pressure polyethylene was 1. : 77. The film produced was a deep green color, with a constant tone, with a completely homogeneously dispersed pigment, without any visible grains of pigment. Increased extract 0.17%! weight.

example

Using the procedure, conditions and apparatus of Example 2, a film was prepared except 0.7 kg of pigment, 0.7 kg of dispersant and 100 kg of polypropylene were used and the extruded melt temperature was 230 ° C.

The prepared film was a deep white color with completely homogeneously dispersed pigment, without any visible grains. Determined increased extract 0.14 wt. Example 9

In a conventional mixer, a mixture of 1.2 kg of TiO ₂ (Byoer Titan RFKD) and 0.8 kg of hexyl-polypropox-polyethoxy-amide, whose mole of polypropox contains 4 propylene oxide moles and 20 moles of ethylene oxide moles, is stirred at room temperature for 5-10 minutes until a homogeneous liquid mixture is formed.

The prepared mixture is dosed in a weight ratio to a 1:50 granulated colorless polyamide before the polyamide enters the screw, into the bottom of the hopper, into which the polyamide granulate is placed, placed on a screw continuous processing machine, where the extruded molten mixture temperature reaches 250 ° C. .

A screw as in Example 1 was fed to the blow head, from which a 0.4 mm thick white color film with uniformly dispersed pigment was obtained, without visible grains.

Example 10

In a mixer such as Example 1, a mixture of 1.2 kg of TiO ₂ (Bayer Titan RFKD) and 0.8 kg of dodecyl-polypropox-polyetox-amer is mixed at room temperature with a mole of polypropox containing 40 molecules of propylene oxide and a mole of polyetox containing 4 molecules. of ethylene oxide, for 5-10 minutes until a homogeneous liquid dispersion mixture is formed.

100 kg of methyl methacrylate prepolymer are metered into a mixing vessel equipped with a stirrer, the stirrer is started and 2 kg of the prepared homogeneous liquid dispersion mixture mentioned above is added while stirring. After stirring for 5-10 minutes, the stirrer is stopped and the prepared mixture is allowed to stand for 20-30 minutes to remove air bubbles. The mixture is then filled into glass molds in which, according to the usual temperature regime, it is allowed to co-polymerize to a solid sheet thickness of 5 mml.

In a commonly used production process without using the above-mentioned dispersant, the preparation of a color paste (the mixture j lasts 24 hours or more and the pigment is not as homogeneously dispersed as in the dispersant process).

Example 11

A homogeneous mixture of 0.8 kg of butyl polypropox-polyethoxomer is prepared at room temperature in an agitator as in Example 1. The mole of polypropox contains an average of 10 propylene oxide molecules and a mole of polyetox an average of 4 polyethylene oxide molecules and 0.3 kilograms of Chromphtal Grun 67 pigment. .

The prepared color mixture is dosed in a weight ratio of 1:70 into polyvinyl chloride. From the resulting mixture by a conventional manufacturing process, a foil of 0.3 mm depth, a deep green color, with a constant tone and complete homogeneously dispersed pigment was prepared.

Claims (4)

SUBJECT clay Process for dyeing pigmentaml plastics using dispersants such as dyeing high-pressure and low-pressure polyethylene, polypropylene, polymethacrylate, polyamide, polyvinyl chloride and other plastics with organic or inorganic pigments and filling with known fillers using dispersants with high dispersing efficiency and known pigment preparation compositions, % filled with colored and natural plastics in the form of granules, powders, foils, moldings, castings and the like, characterized in that 0.02 to 99.0 wt. of a dispersant of the general formula R - (O - CH - CH 2) _X - (O - CH 2 - CH 2) _{y -} OH, CH 3 where is We claim: The R-alkyl of a higher fatty alcohol is C 4 to C ₂ x-4 to 40, preferably 4 to 24 y-2 to 20, preferably 4 to 12. 2. The process according to claim 1, wherein the addition of the dispersant to the final colored plastics is at least 0.02% by weight, preferably in the range of 0.2 to 2.0 why. % by weight, calculated on the plastic. 3. The method of claim 1 wherein the dispersant content of the color blends ap ^; For the coloring of plastics, the maximum quantity of gmental preparations used shall be 99,0 pens. % by weight, preferably in the range of 30.0 to 90.0% by weight, based on the composition or pigment preparation. 4. The method according to claim 1, characterized in that the addition of dispersant is at most 99.0% by weight, preferably in the range of 30.0 to 90.0% by weight, when filling colored and natural plastics. and the difference to 100%! weight. represents a filler.