2013年9月4日星期三

PVC heat stabilizers breed some introductory

PVC primary stabilizers are those have a stabilizing effect when used alone, the compound and the secondary stabilizer is an invalid who used alone with the primary stabilizer compounds Shique synergistic effect. Some primary stabilizer or between certain to choose between the   Acrylic impact modifier main and auxiliary stabilizers act synergistically after use. First, the base of the  lead salt base lead salts are used in PVC earliest and most widely used of a heat stabilizer, alkaline, and it could be heated with PVC, HCl produced REACTED stability. From toxicity, stain resistance and product transparency point of view, lead salt is not ideal. But its stabilizing effect is good, inexpensive, it is still used extensively for cheap PVC extrusion and calendered products. Because it has excellent electrical properties and low water absorption, the PVC is widely used as electrical insulation products, albums and foam stabilizers. 1.1, tribasic lead sulfate  oxidized PE WAX (also known as tribasic lead sulfate) white powder, specific gravity 7.10, sweet, toxic; hygroscopic, non-flammable and corrosive. Insoluble in water, but soluble in hot ammonium acetate, wet decomposition of the light will change color. Index 2.1, and used as electrical insulation products stabilizer. 1.2 Dibasic lead phosphate which is a fine needle-like crystalline powder; specific gravity 6.1, sweet and toxic; 200 ℃ or so into a gray-black, 450 ℃ or so turns yellow. This product is not soluble in water and organic solvents, soluble in hydrochloric acid. Refractive index 2.25, with an antioxidant effect, is an excellent weather resistance stabilizers. Second, the metal soaps metal soaps also a widely used class of PVC heat stabilizer. In carboxylic acid barium, cadmium carboxylate, zinc carboxylate, carboxylic acid, or a mixture of elemental calcium use. Its stabilizing effect is due to it in the beginning of PVC molecular chain decomposition of the place where esterification. Stabilizing effect and the strength of the metal ratio of metal soap, a carboxylic acid type, and the existence of such formulations phosphite, epoxidized oils, the antioxidant synergists. Including cadmium and zinc soap soap greatest stabilizing effect. 2.1 Lead stearate which is a fine powder, is insoluble in water, soluble in hot ethanol and ether. Heated and dissolved in an organic solvent, and then cooling a gum. Case of decomposition of stearic acid and the corresponding lead salts, easy to damp. Has good lubricity, low melting point and that it has the excellent dispersibility. 2.2,2 - ethyl acetate, lead is soluble solvents and plasticizers. Often dubbed 57-60% mineral oil or plasticizer was sold. Widely used in foam blowing agent azodicarbonamide activator. 2.3 Lead salicylate which is a white crystalline powder, specific gravity 2.36, refractive index 1.76. Both PVC heat stabilizers and light stabilizers. 2.4, tribasic lead stearate is a white powder, specific gravity 2.15,280-300 ℃ decomposition, the case of high temperature above 100 ℃ caking. Soluble in ether, poisonous, non-flammable and corrosive. Refractive index of 1.60. This product is good lubricity, good light stability, widely used in PVC formulations title. 2.5, dibasic lead phthalate white fine crystalline powder, specific gravity 4.5. Insoluble in common solvents. This product is weak, and its base portion and easy carbonation. Refractive index of 1.99. When a formula contains a plasticizer easily saponifiable stabilizing effect than tribasic lead sulfate. 2.6, three maleate salt of lead (tribasic lead maleate) yellowish fine powder, specific gravity 6.0, refractive index 2.08, toxic, non-flammable and corrosive, with good color stability, and eliminate unstable diene structure effect. 2.7, barium stearate fine white powder, barium content 19.5-20.6%, the proportion of 1.145, melting point 225 ℃ or more. Insoluble in water, but soluble in hot ethanol. Was heated and dissolved in an organic solvent, after cooling into jelly. Case of decomposition of stearic acid and the corresponding barium salt, easy to damp. Sulfur contamination must be avoided for the selection of the heat stabilizer is used when processed under high temperature lubricant. 2.8, Osmanthus barium
2.9, ricinoleic acid, which is a kind of barium yellow-white powder, mp l16-124 ℃, enabling products to obtain good transparency stabilizer. 2.10, a white fine powder cadmium stearate, cadmium content 16.5-17.5%, insoluble in water, soluble in hot ethanol, heated and dissolved in an organic solvent, a jelly after cooling, in case decomposed into stearic acid and the corresponding cadmium salt, easy to damp. Is required to have good transparency PVC heat and light stabilizers. 2.11, cadmium ricinoleate which is a white powder, mp 96-104 ℃, both heat and light stabilizers 2.12, calcium stearate fine white powder, insoluble in water, soluble in hot ethanol and ether. Case of decomposition of stearic acid and corresponding calcium salt, easy to damp. Is a non-toxic PVC stabilizers and lubricants. Generally not used alone, but often with soap zinc, magnesium soap or vice epoxy stabilizer used in conjunction. 2.13, castor calcium is a white powder, melting point 74-82 ℃, PVC with a non-toxic stabilizers. 2.14, zinc stearate fine white powder, insoluble in water, soluble in hot ethanol, turpentine, benzene and other organic solvents. Was heated and dissolved in an organic solvent, after cooling a gum. Case of decomposition of stearic acid and the corresponding zinc, easy to damp. Is a non-toxic PVC stabilizers and lubricants. 2.15, magnesium stearate white powder, specific gravity 1.07, melting point of pure 85 ℃, industrial mp l08-115 ℃. Slightly soluble in water, soluble in hot ethanol, the case of decomposition of stearic acid and magnesium. This is a non-toxic PVC stabilizers and lubricants, but also phenol and urea formaldehyde resin lubricant. Third, the composite stabilizer 3.1, liquids and liquid barium cadmium, barium cadmium zinc composite stabilizer such composite stabilizer is mainly used for the processing of soft PVC products, the basic components include: (a) barium salt - can be alkyl barium phenol 2 - ethylhexanoic acid, barium laurate, barium, barium benzoic acid and substituted benzoic acid, neodecanoic acid and barium. Barium salt complexes accounted 6-7% salt with cadmium ratio is about 2:1.32 (as metal, by weight, the same below). (2) cadmium salts - can be 2 - ethylhexanoic acid, cadmium laurate, cadmium, cadmium oleate, phenyl and substituted benzoic acid, cadmium, cadmium naphthenate, neodecanoate, and cadmium. Cadmium salt complexes about 3-4%. (3) zinc salt - may be 2 - ethylhexanoate, zinc laurate, zinc naphthenate, zinc neodecanoate, benzoic acid and substituted benzoic acid zinc. Accounts for the composite zinc 0.5-1%. (4) phosphite - may be triphenyl phosphite, diphenyl phosphite, an octyl diphenyl phosphite, a decyl phosphite, tris (nonylphenyl), etc. In the phosphite complexes about 15-20% (by weight), as a chelating agent. (5) Other - include minor amounts of 2,6 - tert-butyl-p-cresol, bisphenol A, nonylphenol and other phenolic antioxidants and ultraviolet absorbers, and a liquid paraffin, white oil, diesel oil, spindle oil mineral oil as solvent, and the need small amount of antifoaming agent such as a higher alcohol. Liquid barium cadmium zinc composite stabilizer because different composition, properties are also different. But is generally pale yellow to yellow clear liquid, specific gravity 0.95-1.02 at room temperature, the viscosity of less than 100 cps, freezing point at -15 ℃ or so. Liquid Ba Ba Cd, Zn and Cd, and similar liquids, has excellent heat and light stability; initial coloration is small, good  titanium dioxide anatase transparency and color stability. Their stabilizing effect than solid composite soaps, therefore, may reduce the amount of, usually 2-3 parts, the dust does not occur poisoning, and completely dissolved in the plasticizer in the general, good dispersion, small tendency to precipitate. Wherein the liquid barium cadmium zinc early color than the liquid barium cadmium smaller. 3.2 Liquid Ba-Zn complexes are generally pale yellow to yellow-brown oily liquid, specific gravity of 1.0-1.1 at room temperature, good heat resistance, pollution from sulfur, with an epoxy plasticizer and used to increase the stabilizing effect on the hair foam agents are activation. 3.3, non-toxic liquid calcium zinc complexes of liquid calcium zinc stabilizer main ingredients are calcium stearate, castor oil, calcium, zinc stearate, castor oil, zinc and epoxy soybean oil, ultraviolet absorber. Liquid calcium zinc stabilizer off
Agents are generally more soluble in organic solvents used fewer carbon fatty acid calcium salts and zinc salts. Because of different compositions, varied in nature, usually pale yellow to yellow clear oily liquid at room temperature under a specific gravity of 1.0 to 1.05. It is non-toxic PVC stabilizer, mainly for food packaging films, containers, and foam stabilizer for leather. Fourth, organotin stabilizers organotin stabilizers are various carboxylic acids derivatives of tin and tin mercaptide, the main products are dibutyl tin and dioctyl tin compounds, which Dioctyltin countries as being more toxic stabilizer be used. Organotin primarily to stabilize rigid PVC products, especially those that require a superior transparency and thermal stability of the product. Of course, soft products can be stably, but because of its price is more expensive, it is generally not used. 4.1, dibutyl tin dilaurate is a pale yellow clear liquid, dissolved in a plasticizer and all industrial solvents, the toxic materials. It is the oldest organotin species, has excellent lubricity, transparency and weather resistance, resistance to sulfur pollution, but the heat resistance is poor. As the main products, soft transparent stabilizers, rigid transparent products used as lubricants. 4.2, dibutyltin maleate which is a white amorphous powder, melting and volatile vary with the degree of polymerization, between about 100-140 ℃. This product is toxic, a tear. Primarily used for high softening point and high impact strength rigid transparent products. Because no lubrication so often and dibutyl tin and used, the amount of 0.5-2. 4.3, bis (monobutyl maleate), dibutyltin light yellow transparent liquid, non-toxic (to allow the amount of 3 parts or less). This product has good weather resistance, transparency, and thermal stability preventing coloration does not occur sulfur pollution, commonly used in transparent PVC rigid products, the amount of 2.0-4.0 parts. 4.4, bis (isobutyl thioglycolate), di-n-octyl tin which is a pale yellow liquid, insoluble in water, soluble in esters, ethers, alcohols, aliphatic and aromatic hydrocarbons, chlorinated hydrocarbons and the major types of plasticizer . It is the main tin mercaptide species, the most commonly used one non-toxic organotin stabilizers for rigid transparent PVC (2-3 copies) and soft transparent PVC (1 copy). The disadvantage is poor weather, the smell would sulfur pollution, no lubrication. In addition, because it contains an ester group, so there is a certain degree of plasticization.

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