Plastic colorant is one of the most commonly used additives in modified plastics. It can not only color plastics, but also achieve beautiful colors. It can also improve weather resistance, improve mechanical properties and improve optical properties. Let's look for plastics to introduce common plastic colorants. 1. Colorants for PVC PVC is an important general-purpose thermoplastic material, which is widely used, including common low-grade and high-grade special performance requirements such as building materials, automobiles, doors and windows, etc. Due to its low processing temperature, various types of organic pigments can be selected. Coloring is carried out, but the coloring agent should be selected specifically depending on the processing conditions, the end use of the colored product, etc., of course, the occurrence of blooming when the coloring of the PVC is avoided. The blooming phenomenon when PVC is colored can be considered to be caused by the partial dissolution of the organic pigment as a coloring agent at the processing temperature and the recrystallization of the pigment at room temperature. This phenomenon also exists in other polyolefin plastics, especially Soft PVC material, because the added plasticizer increases the solubility of the colorant in it, making it more prone to blooming, and as the processing temperature increases, the blooming phenomenon becomes more serious; further, due to the pigment and PVC The compatibility between them is not ideal, especially when certain additives are contained, which may cause supersaturation of the pigment to cause surface precipitation. Therefore, for the coloring of PVC, different grades of organic pigments can be selected according to different requirements: 1 Universal colorant, good economical, but generally durable (yellow, orange and red) varieties are CI Pigment Yellow 61, CI Pigment Yellow 168, CI Pigment Orange 13, CI Pigment Orange 34, CI Pigment Red 48:1 , CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 57:1, CI Pigment Red 57:2. 2 Excellent coloring agents (yellow, orange and red) are: CI Pigment Yellow 139, CI Pigment Yellow 183, CI Pigment Yellow 191, CI Pigment Orange 43, Graphtol Fast Orange 5GL, CI Pigment Red 151, CI Pigment Red 214 , CI Pigment Red 242. 3 Colorants suitable for outdoor coloring products are: CI Pigment Yellow 24, CI Pigment Yellow 110, CI Pigment Brown 23, CI Pigment Brown 25, CI Pigment Red 122, CI Pigment Blue 15, CI Pigment Blue 60, CI Pigment Green 7, CI Pigment Violet 23. Second, Pa coloring agent The colorant used for Pa may be either an organic pigment or a dye dissolved in a polymer. Organic pigments for Pa coloring can be divided into two grades: 1 The general performance of organic pigments are: CI Pigment Yellow 148, CI Pigment Yellow 150, CI Pigment Yellow 187, CI Pigment Red 149, CI Pigment Red 177, CI Pigment Violet 23. 2 The organic pigments with excellent performance are: CI Pigment Yellow 192, CI Pigment Orange 68, CI Pigment Blue 15:3, CI Pigment Green 7. Among them, CI Pigment Yellow 192 is a bright red-yellow yellow heterocyclic pigment without metal. It has high heat stability (300 ° C) and excellent weather fastness at low concentration, and can be combined with titanium dioxide and zinc sulfide. Inorganic pigments are used in combination; CI Pigment Orange 68 is a bright red orange nickel complex pigment containing a benzimidazolone group, which has excellent light and heat resistance. Third, colorants for polyester materials Polyester materials (including PET and PBT) can be pigmented with pigments such as CI Pigment Yellow 138, CI Pigment Yellow 147, CI Pigment Red 214, CI Pigment Red 242, etc., or can be colored with solvent dyes that are soluble in polymers, such as Estofil. S (Clar), Polysynthren (H?), Filester (Ciba), etc. Fourth, aBS coloring agent The coloring of aBS is mostly a solvent dye which is soluble in a polymer, and has not only good transparency but also good light fastness, and if it is used together with an inorganic pigment, an opaque colored product can be obtained; Commonly used solvent-soluble solvent dyes include: CI Solvent Yellow 93, CI Solvent Orange 60, CI Solvent Red 111, CI Solvent Red 135, CI Solvent Blue 104, CI Solvent Green 3, and the like. 5. Colorants for PS, SaN, PC, etc. These thermoplastics have excellent transparency. In order to maintain the original transparency of the colored products, in addition to the coloring of some of the above pigments, solvent dyes and disperse dyes with high solubility are preferably used to dissolve them in the coloring process. A stable molecular solution is formed in the plastic, showing high color strength, such as Macrolex series dyes (By), varieties include Macrolex Yellow 6G, Yellow G, Yellow R, Orange GG, Red GS, Red 5B, Red 7B, Violet R, Violet 3R, Violet B, and Green 5B are used in an amount of 0.025% to 0.05%, and heat resistance can be 280 to 300 °C. Effect of colorants on antioxidants and light stabilizers of products Pigments or dyes that change the color of the plastic material while imparting a pleasing appearance to the plastic article can be referred to as plastic colorants. Due to the different types and chemical structures of chemical elements contained in the colorant molecules, not only the main properties of plastic colorants such as use, tinting strength, hiding power, coloring durability or firmness, weather resistance, chemical resistance, and toxicity are significant. The difference, but also the processing and formability of the colored plastic products, the thermal oxygen stability during processing, the light and oxygen stability during use have a certain impact. Especially for light-colored and oxygen-stabilized colored plastic products, if the plastic colorant is improperly combined with antioxidants and light stabilizers, it may cause premature fading or discoloration of the colored plastic products, and accelerate the light and oxygen aging rate of the colored plastic products. The appearance and physical and mechanical properties of the product are deteriorated, and the original function and use value are lost in advance. In fact, in the three stages of production, processing, storage and use of colored plastic products, such phenomena sometimes occur. 1. Effect of colorant on antioxidant efficiency Chrome yellow is an opaque inorganic colorant. It can be used in thermoplastics such as polyolefin, polystyrene, and acrylic resin. It has strong coloring power, good hiding power, and excellent water and solvent resistance. However, because chromate yellow is a lead-containing compound composed of lead chromate or basic lead chromate and lead sulfate, it is shared with sulfur-containing antioxidants DLTP, DSTP, 1035, 300, etc., and chemistry occurs under high temperature conditions of plastic processing. The reaction produces black lead sulfide, which affects the appearance of plastic products and greatly impairs the antioxidant aging resistance of antioxidants. Therefore, chromium-containing colorants cannot be used in combination with sulfur-containing antioxidants. Polypropylene molecular chain contains tertiary carbon atoms, which are easily decomposed by oxygen. In processing, storage and application, antioxidants must be used for anti-aging protection. In the case of colored polypropylene, certain colorants chemically react with low molecular hindered phenol antioxidants to weaken the action of the antioxidant. The effect of some colorants on the efficacy of low molecular weight phenolic antioxidants in polypropylene (see Table 1) can be divided into three categories: (1) Serious effects: channel black, monoazo red 3B, quinacridone magenta, phthalocyanine blue, iron oxide yellow brown; (2) Moderate impact: phthalocyanine green, furnace black, ultramarine blue, chrome oxide green; (3) Slightly affected: cadmium yellow, (vulcanized) mercury cadmium red, rutile titanium dioxide [1]. Table 1: Effect of colorant (0.5%) on thermo-oxidative stability of phenolic antioxidant polypropylene Carbon black is the black colorant used in many plastic materials and products, and can be used as a light stabilizer for plastic materials. In addition to the weakening effect of some phenolic antioxidants in polypropylene, carbon black can also interact with the antioxidant BHT in low-pressure polyethylene, making BHT almost completely ineffective, and at the same time, carbon black itself The light stabilizing effect is also greatly reduced. The outdoor exposure life of low pressure polyethylene sheets with 1% channel black and 0.1% BHT added is only about 40% of the outdoor exposed life of low pressure polyethylene sheets with a single 1% channel black. For plastic materials such as polyethylene and polypropylene, when carbon black is used as a coloring agent or a light stabilizer, an appropriate antioxidant must be selected. Otherwise, it not only reduces the effectiveness of the antioxidant, but also reduces the outdoor light stability of the colored plastic article. Titanium dioxide and pearl powder, when used in combination with the monophenolic antioxidant BHT in some resins, can turn white products yellow and cause product quality problems. 2. Effect of colorants on the performance of light stabilizers The effect of colorants on the efficacy of light stabilizers in pigmented plastics has two main effects. (1) The coloring agent contains heavy metal elements or impurities such as copper, manganese, nickel, etc., and has photoactivity and photosensitivity, catalyzing and accelerating the photoaging speed of the plastic material. Phthalocyanine blue containing free copper and impurities promotes photoaging of polypropylene; iron oxide red can reduce the performance of benzotriazole, benzophenone and organic nickel salt light stabilizer in polypropylene by more than 20%; Ethylene, which uses colorants such as titanium dioxide, ultramarine blue, chrome oxide green, cobalt green, and iron red, can exacerbate photoaging. (2) Some molecular structure colorants can act with light stabilizers, directly impairing the performance of light stabilizers. The acid colorant can disable the hindered amine light stabilizer; in polypropylene, azo red and azo yellow can interact with the hindered amine light stabilizer, such as azo condensation red BR, azo condensation yellow 3G can make hindered amine The efficacy of light stabilizers decreased by about 25% and about 50%, respectively. Table 2 shows the effect of different colorants on the photostability of high pressure polyethylene containing benzotriazole light stabilizers (UV-328). It can be seen that the orange chrome yellow significantly improves the light stability of the high pressure polyethylene, and the phthalocyanine green and the ultramarine blue slightly increase or have little effect, while the cadmium yellow reduces the light stability of the high pressure polyethylene. Table 2: Effect of different colorants on the photostability of benzotriazole-containing high pressure polyethylene films [Plastic additives] What are the 9 major plastic additives? Plastics need to add different kinds of plastic additives in the processing to meet different processing and application requirements. Xiaobian today briefly introduces the classification and characteristics of these additives~ What are the additives? A plastic additive is a chemical substance that is dispersed in a molecular structure of a plastic and does not seriously affect the molecular structure of the plastic, but can improve its properties or reduce the cost. The addition of additives can promote plastics to improve the processing, physical, chemical and other functions of the substrate and increase the physical and chemical properties of the substrate. Cm Lodestar,Electric Hoist 1 Ton,1 Ton Electric Chain Hoist,2 Ton Electric Chain Hoist Guangdong Gongyou Lift Slings Machinery CO.,LTD , https://www.gongyouslings.com
