High styrene resins

294 Aliphatic Polyolefins other than Polyethylene, and Diene Rubbers II.7.4.1 High-styrene resins  

Butadiene and styrene may be polymerised in any proportion. The Tfs of the copolymers vary in an almost linear manner with the proportion of styrene present. Whereas SBR has a styrene content of about 23.5% and is rubbery, copolymers containing about 50% styrene are leatherlike whilst with 70% styrene the materials are more like rigid thermoplastics but with low softening points. Both of these copolymers are known in the rubber industry as high-styrene resins and are usually used blended with a hydrocarbon rubber such as NR or SBR. Such blends have found use in shoe soles, car wash brushes and other mouldings but in recent times have suffered increasing competition from conventional thermoplastics and to a less extent the thermoplastic rubbers. 

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Hard products may also be made by vulcanising rubber (natural or synthetic) using only about two parts of sulphur per 100 parts of rubber. In these cases either the so-called high-styrene resins or phenolie rubber compounding resins are ineorporated into the formulation. These compounds are processed using the methods of rubber technology but, like those of ebonite, the produets are more akin to plastics than to rubbers. Examples of the usage of these materials are to be found in battery boxes, shoe heels and ear washer brushes. 

Isocyanates can be added to solvent-borne CR adhesive solutions as a two-part adhesive system. This two-part adhesive system is less effective with rubber substrates containing high styrene resin and for butadiene-styrene block (thermoplastic rubber) copolymers. To improve the specific adhesion to those materials, addition of a poly-alpha-methylstyrene resin to solvent-borne CR adhesives is quite effective [76]. An alternative technique is to graft a methacrylate monomer into the polychloroprene [2]. 

One of the most important solution blend polymers is high-styrene resin, which is manufactured by several companies worldwide. This is a latex blend of high-styrene rubber and normal styrene butadiene rubber. The different high-styrene master batches are available in the world as ... 

A chemical compound consisting of groups of atoms which are repeated almost indefinitely until very high molecular weights are achieved. High Styrene Resins... 

Compounding ingredients which bring about reinforcement of rubbers. The most widely used are carbon black, silica and silicates, zinc oxide, treated whitings, high styrene resins and phenolic resins. 

Blends of natural rubber or styrene-butadiene rubber with high styrene resins used as soling material in footwear manufacture. Such resin rubbers should not be confused with... 

Microcellular Rubber A product usually used for shoe soling application produced by the incorporation of a blowing agent into the high styrene resin soling compound. 

Organic zinc-rich primers are based on epoxy/polyamides, high-molecular-weight linear epoxies, moisture-cured urethanes, high-styrene resins, chlorinated rubbers and epoxy esters. In this type of primer zinc is covered with a monomolecular layer of the binder which facilitates the adhesion of the film to the substrate. 

Various kinds like coumarone resins, petroleum resins, high styrene resins and phenolic resins are used to give excellent flow characteristics during moulding, calendering and extruding. 

These may be used for low hardness compounds in areas where impact abrasion is predominant. EPDM is at times referred as crackless rubber5 since it has high tear resistance. For producing high hardness compounds blends with natural rubber, styrene-butadiene rubber (SBR) and high styrene resins are recommended. 

H-260. [Housmex] SBRniastabatchwidi high styrene resin for blending with SBR and odier polymers. 

HSB 1900, 1903, 1904. [Mach-1 Compounding] High styrene resin/SBR fluxed blend used in shoe soles and household goods. 

Reinforcing Resins. The main types of reinforcing resins used in rubber compounds are high-styrene resins and phenolic resins. The high-st5rene resins are copolymers of styrene and butadiene wherein 50 to 85 percent of the polymer is derived from styrene. They are used to stiffen NR and SBR rubber compounds, for example, in shoe soles. Phenolic resins are used for reinforcing NBR compounds. The phenolic resin is... 

Curing Stiffening agent High styrene resin—rubber Masterbatches Phenolic resins trares-polyoctenamer Increased hardness... 

Styrene-butadiene copolymers containing about 85% styrene are also available and are commonly known as high-styrene resins . These products can be vulcanized to give hard products but their chief use is in the reinforcement of natural and styrene-butadiene rubbers. A typical use of these compositions is in the production of shoe soles with good abrasion and flex resistance. 

By far the bulk of SBRs have a styrene content of about 23 5% this being generally believed to give the best balance of properties. This balance is of course affected by the vinyl content and to some extent the phenyl group on the styrene and the vinyl group of the 1,2-polybutadiene unit are interchangeable. High styrene resins contain-... 

The advent of solution polymers has enabled some control to be exerted on the distribution of the two monomers in the polymer chain. In those polymers that show a degree of blockiness about two-thirds of the bound styrene is present in the form of blocks of more than five styrene monomer units. The polymers are somewhat easier to process but harder and less elastic. The effect is somewhat reminiscent of that obtained by adding a high styrene resin to a normal grade of SBR. 

Cyclized natural rubber has been of some use in providing stiffness to diene rubber vulcanizates without materially increasing the density. For this purpose it is in some competition with the high styrene resins. Furthermore there are today a number of elastomers available, alternative to the diene polymers blended with cyclized rubber or high styrene resins, such as certain block copolymers and polyurethanes which possess this property without the need to add such stiffening fillers. 

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