CS220946B1 - Dying the plastic materials - Google Patents

Description

The present invention relates to a process for dyeing plastics with organic or inorganic pigments and to fill with fillers using oil-soluble dispersants of the succinimide, phosphonate and polymethacrylate type which they provide. a high degree of dispersion of the pigment and fillers and their complete uniform dispersion in the plastic.

Pigments are organic or inorganic powders practically insoluble in the dyed plastic material. Due to the high thermal stresses during processing, there is a possibility that some organic pigments will at least partially dissolve. Pigments consist of particles whose size increases in order: primary particles (single crystals), aggregates and agglomerates. The color efficiency of pigments increases with the particle malosphere. The pigment dispersion is essentially a crushing, removal of 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. Reducing the melt viscosity of the plastic further promotes 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 gra220946 nano. 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 plastic in mixing units of various types (drum, fluid mixer) and subsequently processed in extruders or spray machines. The plastic may also be colored by adding commercially available or on-site pigment preparations to the processing of the machine without premixing.

The most important inorganic pigments used are TiCK pigments (especially rutile) and zinc sulphide pigments with different ZnS content up to 100% (less effective than TiO 2 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 Fe, Cr and Cu oxides, cadmium pigments of CdS or Cd-sulphide composition (selenide, chromate mixed phase pigments of the composition Pb (Cr, S) CU and Pb (Cu, Mo, S) O4 Pigments can also be counted as a filler if its refractive index in a certain environment is more than 1.7. 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. Due to the high technical demands such as high thermal and migration stability, wettability and dispersibility, the choice of a large number of organic pigments is considerably narrowed and the suitable pigment must be sought and tested. To facilitate this selection, according to the above-mentioned indicators, generally suitable organic pigments for the plastic sector are summarized in special assortments, in particular of large pigment manufacturers.

The dispersants of the present invention promote the wettability and dispersibility of the organic pigments and allow a very rapid process for preparing 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 working properties. temperatures in the range of 200 to 300 ° C. They are particularly suitable for high- and low-pressure polyethylene, polypropylene, polystyrene and styrene mixed polymerizates, polyvinyl chloride and its copolymers, as well as phenolic and polyester resins, urea and melamine resins, polymethacrylates, polyamides and others.

The dispersants of this invention are viscous solutions of known oil-soluble additives used in lubricating oils (see, e.g., V. Stepin, V. Vesely: Lubricants and Specialty Oils, SAV 1980), succinimide, preferably bissuccinimide, alkenyl phosphonate, thiophosphonate, especially calcium and barium. intermediate and alkenylthiophosphate and polymethacrylate additives containing nitrogen bound in the molecule.

The dispersants of the present invention ensure, on the one hand, the perfect color effect of the pigment such as color saturation, color tone and its stability, gloss, hiding power and, on the other hand, improve the economics of production by significantly reducing pigment consumption by up to one third or more compared to known dispersant-free staining methods. .

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 pulverization of pigments that only special pigment preparations which are characterized by a high degree of dispersion of the pigments contained can satisfy them.

An advantage of the dispersants of the present invention is also that, due to their dispersing effect, no visible grains of pigment are present or adhered to the walls of the machinery and containers due to their dispersing effect and allow sharp, very rapid transition to products of 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.

The dispersants of the present invention can be used to prepare color blends that are immediately processed at the point of manufacture of colored plastics, as well as long-term stable pigment preparations (concentrates), which may be conventional commercial products in the form of granules, powders, pastes, viscous liquids. These concentrated preparations may contain up to 99.0% by weight, preferably about 35 to 90% by weight, of the pigment in dispersed form, and comprise, in addition to the pigment, a dispersant and may further comprise a plastics material. , to be colored, plasticizers, other auxiliaries or mixtures thereof which are compatible or miscible with 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 wetting agents and fillers and in the form of a liquid mixture or paste, are added by hatching or continuously (by pump), depending on the type of processing machine, in specified proportions to the plastic, through a tube extending to the bottom of the granulate, powder dispenser or a melt of a plastic placed on a processing machine such as a shot, 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 dispersion rate of these dispersants, various concentrated dispersant mixtures, pigments and fillers, and possibly other on-site auxiliaries can be used in the manufacture of colored and filled plastics, eliminating the pre-preparation of colored granules, powders, pastes. 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 also improve the sliding, antistatic and anti-blocking 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 invention is their suitability for use in addition to dyeing plastics as well as in the preparation of filled or dyed filled plastics, fillers such as powder chalk, special 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 known organic and inorganic pigments and for filling colored, natural filler plastics, using the dispersants of the present invention and known processes for producing spirits of concentrated color mixtures, concentrated pigment preparations, filled color or natural plastics and color products from plastics in the form of granules, powders, films, moldings, castings and the like. characterized in that the addition of dispersants to the plastics material is at least 0.01% by weight, preferably in the range of 0.3 to 3.0% by weight, based on the plastic material, the content of the dispersant in color mixtures and pigment preparations is at most 99.0% by weight, preferably in the range of 35.0 to 90.0% by weight, based on the color composition or pigment preparation, and when filling colored and natural plastics, the dispersant addition is at most 99.0% by weight, it is preferably in the range of 35.0 to 90.0% by weight, based on the dispersant / filler mixture.

The following non-limiting examples illustrate the following examples.

Example 1

In a conventional mixer, 0.5 kg of Plexol 956 polymethacrylate additive, 1.0 kg of white oil, is mixed at room temperature and

1.5 kg T1O2 (Bayer Titan RFKDj) until a homogeneous liquid mixture is formed.

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

A length to diameter screw of 20: 1, was fed to the blow head to obtain a 0.2 mm thick blotch foil with a completely uniformly dispersed pigment without any visible grains.

For dosing the liquid dispersion, a peristaltic pump equipped with speed control to a continuously 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 1.5 g of a white oil, 0.5 kg of the bissuccinimide additive S5A and 0.5 kg of carbon black, n.o. FLAMMRUSS.

The prepared homogeneous color mixture was treated with granular high pressure polyethylene at a weight ratio of 1:45 on a 0.3 mm thick film on the apparatus and under the conditions of Example 1. The produced film had a saturated black color, with completely uniformly dispersed pigment, without any visible grains .

Example 3

A homogeneous liquid mixture consisting of 0.9 kg of white oil, 0.45 kg of homemade PMD thiophosphonate and 0.4 kg of Chromphtal Blau pigment was prepared according to the procedure and conditions as in Example 1.

The prepared color mixture was treated with granular polypropylene at a weight ratio of 1:60 on a 0.2 mm thick film on the apparatus and under the conditions of Example 1. The produced film had a clear blue color, with completely uniformly dispersed pigment, without visible pigment grains.

Example 4

The prepared homogeneous color mixture as in Example 2, containing the bissuccinimide additive S5A, was treated with a granular colorless polyamide in a weight ratio of 1:50 on a 0.3 mm thick film. The foil produced had a black color, with evenly distributed pigment, without visible grains of pigment.

Example 5

The prepared color mixture as in Example 3, containing the PMD thiophosphonate additive, was treated with polyvinyl chloride at a ratio of 1: 55 by weight to a 0.2 mm thick film under the usual manufacturing conditions. The foil produced had a clear blue color, with a completely uniformly distributed pigment, without visible grains of pigment.

Example 6

50 kg of methyl methacrylate prepolymer are added to the vessel equipped with the stirrer, the stirrer is started and 1 kg of the prepared color mixture as in Example 1 containing the Plexol 956 polymethacrylate additive is added with stirring. After stirring for 10 minutes followed by addition of the color mixture, stop, and allow the mixture to stand for 30 minutes to remove air bubbles. The mixture thus prepared is filled into glass molds in which, according to the usual manufacturing process, it is allowed to polymerize to solid sheets of 4 mm depth.

In a dispersant-free manufacturing process, the preparation of the color mixture takes about 24 hours or more and the pigment is not as completely dispersed as in the dispersant process.

Example 7

The prepared paraffin mixture as in Example 1 was treated with polystyrene at a ratio of 1:60 to a film of 0.3 mm thickness. The product had a white color, with evenly distributed pigment, without visible grains of pigment.

Claims (1)

Dyeing of plastics such as low-pressure and high-pressure polyethylene, polypropylene, polystyrene and its copolymers, polyvinyl chloride, polyamide, polymethacrylate and other organic or inorganic pigments and filling with known fillers, using known processes for preparing color mixtures, pigment preparations, filled plastic and natural materials in the form of granules, powders, foils, moldings, castings, fibers, characterized in that at least one of the oil-soluble dispersants is used, such as succinimide additives, preferably bissuccinimide additives, polymethacrylate additives containing nitrogen bound in the molecule, medium base, wherein the addition of dispersants, calculated as 50% oil solutions, is at least 0.01% by weight, preferably in the range 0.2 to 2.5% by weight, of the colored plastics, for the final plastic, in the color blend and pigment preparations is at most 99.0% by weight, preferably 30.0 to 90.0% by weight, calculated on the color blend or pigment preparation and in the filled color and natural plastic % of the substances is at most 99.0% by weight, preferably 30.0 to 90.0% by weight, based on the dispersant / filler mixture.