Several Theoretical Issues of PVC heat stabilizers

1 Overview
PVC heat stabilizers are of practical value resin can become

indispensable plastic additives, for decades, the study of the thermal

decomposition mechanism and PVC heat stabilizers of the action, have a

great development, but heat stabilizers some theoretical issues, such

as the commonly used metal soap heat stabilizers, why zinc, cadmium,

aluminum soap in PVC in class early color small, and barium, calcium,

strontium initial coloring on larger? Same as Sn, Sb initial heat

stabilizer why organic carboxylate thermal stabilizer coloring big? And

its corresponding thiol salts early color WSD PVC plasticizer  on the small? And so on very

rare reports, the authors try to use the theory of atomic structure

theoretical analysis on some issues, engaged in the production and

application of heat stabilizers colleagues or some benefit.
2, organotin more excellent heat stability of the same alkyl mercaptan

more excellent than the initial thermal stability than the tin

carboxylate organotin carboxylate. The reason is due to the structure

of the tin atoms linked sulfur and oxygen caused by different. Oxygen

and sulfur cycle in the same element as the sixth element, the

difference lies in their different electronic structure. Here I want to

emphasize is: since heat stabilizers stable reaction types, only the

elimination of PVC unstable reactive  WSD stearic acid chlorine atoms and anti-oxidation

reaction is fundamentally prevent the degradation of PVC on the cross

Union, others, such as the absorption of hydrogen chloride, carbon ions

and undermine the positive reaction of the double bond are more serious

in PVC has exploded later (already de-HCL, after the formation of a

number of double bonds) remedy, which can eliminate unstable heat

stabilizers have a chlorine atom good initial hue (no or less to form a

double bond).
PVC heat stabilizers eliminate unstable premise that two chlorine

atoms, one of the stabilizer and the metal ions have a strong

complexation unstable chlorine atom; the other is an organic anion of a

strong carbon (C? ?) initial significant complexing capacity, only two

were strong complexing ability of PVC was small. (Nearly colorless,

both strong and mercaptan, the tin mercaptide heat stabilizer for PVC,

PVC excellent in hue, hue holding time is longer).
3, the initial metal soap coloration  WSD Chlorinated paraffin and long-term thermal stability of

organotin
3.1 is the beginning of soap coloring
    I found an interesting phenomenon at work, the nature of Mg and Ca

soap soap is very similar (initial coloring serious, but a better long

-term thermal stability), and Al and Zn soap soap is very similar

(excellent initial hue and serious "zinc burn" phenomenon); Mg, Ca, Sr,

Ba are the second main group of the periodic elements are similar in

nature, well understood, but it is the third main element Al, and Zn,

Cd is the second sub-group elements, their chemical properties very

similar to what it? Of course, there are diagonal periodicity principle

can explain this phenomenon, but the similarities and differences

between the chemical properties of the elements, the fundamental reason

is the similarities and differences between their atomic structure, its

external representation is characteristic of the original rare earth

heat stabilizer is a unique " Coupling resistance. " Because of this

feature to make it appear to have in the processing of the lubricant

additives and processing characteristics, promote resin plasticizing;

show excellent impact resistance agent effectiveness in increasing the

PVC toughness, improve the mechanical properties of products in the

finished product; with When oxygen-fillers such as CaCO3 and other

effects, the performance of "Capacity" effect, without affecting the

mechanical properties of the conditions that can increase the amount of

CaCO3.

Environmental plasticizer widely used physical and chemical methods

 I produced the environmental plasticizers plasticity agent for the cold type environmental plasticizers, it has a high plasticizing effect, good compatibility with the product, no oil leakage, no overflow, non-volatile, and high brightness products, the product can replace the original plastic additives dibutyl, dioctyl, the price is much lower than similar products. It is widely used in PVC plastics, rubber, sealing  WSD aluminium stearate strips, car tires, footwear, cables, plastic sheeting, granulation, waterproofing membrane, polyurethane waterproof coating, leather, plate, sheet, PVC hoses, shoe soles materials, rubber boots, etc., is an environmentally friendly green rubber industry plasticizer.
  Plasticized rubber material that can be applied in some of the rubber, the rubber can make the interaction between the molecules is reduced, thereby reducing the glass transition temperature of the rubber, rubber-Sik plasticity, fluidity, easy rolling, extrusion molding, etc. operations, while also Some vulcanized rubber to improve mechanical properties such as hardness and reduced modulus, high elasticity and gives lower heat, cold, etc. improve.
The rubber can be plasticized by physical and chemical methods. Including chemical plasticizing the plasticized masticated masticated rubber processing technology are, at the time of plasticized synthetic rubber in the rubber through chemical reaction the introduction of the flexible molecular chain structure of the molecule can be increased to achieve the purpose of the plasticized . Not because of the chemical plasticized material from the plasticizing effect of volatile or precipitates lose its role plasticizing effect for a long time and therefore more attention. Physical plasticizing additional material refers to a method to achieve the purpose of plasticizing the purpose of said plasticized usually WSD Chrolinated polyethylene  refers to the physical plasticized physical plasticizing substances known to soften the external environmental plasticizers.
Rubber softening environmental plasticizers usually divided according to their polarity and use softeners and environmentally friendly plasticizer. Derived from natural substances, called for a non-polar rubber softener; mainly used polar synthetic rubber or plastic  WSD stearic acid material called environmentally friendly plasticizer. Currently the industry collectively environmental plasticizers.
Environmental plasticizer used in the production process should meet the following conditions: plasticizing effect, with less absorption speed, good compatibility with rubber, small volatility, do not migrate, cold is good, water, oil and solvent resistance, heat resistance, light resistance, electrical insulation, flame resistance and good resistance to bacteria, colorless, non-toxic, cheap and so on.

Quotes optimistic about the domestic PVC stabilizer

Heat stabilizers for PVC processing mainly , it can reduce the degradation of PVC due to heat discoloration and light effects occur , effectively extending the life of the article . The PVC has high strength , corrosion resistance, fire retardant, insulation, transparency advantages, use very extensive. PVC products in the country has been a dominant species . In recent years, the amount of domestic production and processing of PVC resin significant growth for several years , with an average growth rate above 20 %. Soft PVC export-oriented products has been a greater impact , but not a big part of the proportion accounted for a large amount of consumption of PVC plastic pipe head , plastic profiles and wire and cable products is still very optimistic about the prospects for the . Particularly in order to cope with the adverse effects of the global financial crisis brought to China , the Chinese government plans to invest from the beginning of the end of last four trillion yuan , deploy and implement 10 measures to expand domestic demand . In the 10 measures to boost domestic demand , the major water conservancy projects will be extensive use of PVC pipe and film material ; in affordable housing projects , the construction of low-cost housing in shantytowns , nomadic population of plastic doors and windows are indispensable less ; in urban power grids , rail roads and airports and other major infrastructure construction, PVC wire and cable are basic materials, each laying a kilometer high-speed rail , you need a variety of cables up to 5 km; car industry, electronic information industry and light industry revitalization , will be more directly increase demand for various PVC products and spare parts . Huge investment in these projects , and many pre-project funds are already in place, is under construction. These favorable for heat stabilizer industry is real. Piece of cake in the heat stabilizer industry assigned to a small cup of soup as long as it has been very tempting.

Our industry is facing a major problem of calcium stearate

 The main problem facing the industry of calcium stearate is irrational allocation of resources. Domestic producers can be divided into three kinds of production types: one has its own raw material resources, and second, there is a downstream product support, three are two in appearance (no upstream raw materials, no downstream product). Currently the first three types of calcium stearate companies have not considered how profitable, but only in the defenses of the losses do everything possible to maintain survival.
 Followed by the consumption ratio is irrational. Consumption of calcium stearate From a global perspective, unsaturated  Chrolinated polyethylene polyester resins are generally 45% to 50%. In China, the proportion of consumption of calcium stearate in the field in 2003 was as high as 72%. This shows that the scope of application of calcium stearate small and simple. Thus, calcium stearate domestic industry's market risk is relatively increased.
The role of calcium stearate and calcium stearate characteristic is often used as a heat stabilizer and a variety of plastics processing PVC lubricants, mold release agents. In rigid products, and the base of lead salts, lead soap can increase the rate of gelation. Also used in food packaging, medical equipment and other requirements of non-toxic soft film and equipment. Calcium stearate can be made of polyethylene, polypropylene, halogen absorbers to eliminate the adverse effects of residual catalyst on the color and stability. As plasticizers in rubber processing, enabling  stearic acid natural rubber and synthetic rubber to soften the whole, and almost no effect on curing. Also used as polyolefin fibers and molded plastic lubricants, grease thickening agent, textile waterproofing agent, paint flatting agent, plasticizer manufacturing plastic labels and so on.
 Zinc stearate Uses: mainly used styrene resin, phenolic resin, amino resin, lubricant and release agent. While also having a rubber vulcanizing agent, softening function. Can be used as  non-toxic PVC heat stabilizers, coloring and suppress initial lubrication, and no curing pollution, but limited thermal stability, the formation of zinc chloride with  PVC flame retardant catalytic degradation of PVC, is generally not used alone, more than with calcium soap, barium soap stabilizers used in conjunction with, mainly for soft products.