Vinyl leather

Can be used on various soft surfaces such as vinyl, leather, rubber and plastics. This formulation imparts excellent gloss to a vinyl surface and resists multiple detergent washings. 

Azodicarbonamide is mainly used as a blowing agent for making vinyl foams, in particular, calendered vinyl leather. This works as a blowing agent by releasing nitrogen and produces a foam. 

Polyvinyl chloride (PVC) is often produced by suspension or emulsion polymerisation. It is used extensively in producing PVC pipes for construction. Impact modifiers are often added to strengthen the material. PVC is also used in plastisols for dipped coatings, in shower curtains, and in vinyl leather. Nonvolatile plasticisers are necessary in such applications where the material must remain flexible. Because PVC is a very hydrophobic polymer with good barrier properties, it makes an effective obstacle to oxygen and water vapour in packaging films. 

Lower plastisol gel and fusion temperatures. This translates to faster production in applications such as resilient flooring, molding, dip coating and vinyl leather cloth. 

Resilient flooring Vinyl leather cloth Plastisol ink Automotive sealants. 

A.2 Vinyl Leather Cloth Vinyl leather is very similar to flooring construc-... 

Poly(vinyl chloride) (PVC) has re placed leather in many of its appli cations PVC tubes and pipes are often used in place of copper... 

Sintering has been used to produce a porous polytetrafluoroethylene (16). Cellulose sponges are the most familiar cellular polymers produced by the leaching process (123). Sodium sulfate crystals are dispersed in the viscose symp and subsequently leached out. Polyethylene (124) or poly(vinyl chloride) can also be produced in cellular form by the leaching process. The artificial leather-tike materials used for shoe uppers are rendered porous by extraction of salts (125) or by designing the polymers in such a way that they precipitate as a gel with many holes (126). 

In the second quarter of the twentieth century, with the development of poly(vinyl chloride), nylon, polyurethane, and other polymers, many new and improved leather-like materials, so-called coated fabrics (qv), were placed on the market. Shortages of leather after World War 11 led to the expansion of these leather-like materials ("man-made" leathers) to replace leather in shoes, clothing, bags, upholstery, and other items. DurabiUty and waterproof quahties superior to leather made coated fabrics advantageous, in spite of imperfection in breathabihty and flexibiUty. Demands for shoes, clothing, and other items are stiU increasing due to growing world population and urbanization. 

Leather-like materials now important in the market are of three main classes (/) vinyl-coated fabrics, (2) urethane-coated (synthetic) fabrics, and (J) man-made leathers. To appreciate their leather-replacement capabiUties it is necessary to know the stmcture of natural leather. 

Vinyl-Coated Fabrics. Leather substitutes are designed to imitate the appearance of leather with its grain surface. This requirement has been accomphshed by coating substances that are capable of forming a uniform film, and was first met by plasticized poly(vinyl chloride) (PVC). A leather-like material termed vinyl-coated fabric was developed in the 1930s in the United States and Germany. Shortages of leather after World War 11 spurred the expansion of this material. 

Product is nylon in man-made leathers cotton in urethane- and vinyl-coated fabrics. 

Weight, Thickness, and Density. The thickness differs according to appHcation. Vinyl-coated fabrics are very heavy and dense. Urethane-coated fabrics and man-made leather are very light and two-thirds to one-half leather in density. 

Water-Vapor Permeability. Water-vapor permeabiUty depends on the polymer used for the coating layer and its stmcture. Vinyl-coated fabrics have Httie water-vapor permeabiUty due to the coating layer. Although polyurethane polymer is water-vapor permeable, urethane-coated fabrics also have low permeabiUty values due to their soHd layer stmcture. On the other hand, man-made leathers have good permeabiUty values as high as that of leather due to their porous layer stmcture. The permeabiUty of grain-type is lower than that of suede-type, influenced by finishing method. 

Other Properties. With respect to dry-cleanabiUty, vinyl-coated fabrics are worse than the others due to dissolution of plasticizer in the cleaning solvent. Only man-made leathers with poromeric nonwoven can be skived, spHt, and cut in the same manner as leather. 

Poly(vinyl acetate) homopolymers adhere well to porous or ceUulosic surfaces, eg, wood, paper, cloth, leather (qv), and ceramics (qv). Homopolymer films tend to creep less than copolymer or terpolymer films. They are especially suitable in adhesives for high speed packaging operations. 

Other. Vinyl acetate resins are useful as antishrinking agents for glass fiber-reinforced polyester mol ding resins (165). Poly(vinyl acetate)s are also used as binders for numerous materials, eg, fibers, leather (qv), asbestos, sawdust, sand, clay, etc, to form compositions that can be shaped with heat and pressure. Joint cements, taping compounds, caulks, and fillers are other uses. 

A number of higher poly(vinyl ether)s, in particular the ethyl and butyl polymers, have found use as adhesives. When antioxidants are incorporated, pressure-sensitive adhesive tapes from poly(vinyl ethyl ether) are said to have twice the shelf life of similar tapes from natural rubber. Copolymers of vinyl isobutyl ether with methyl acrylate and ethyl acrylate (Acronal series) and with vinyl chloride have been commercially marketed. The first two products have been used as adhesives and impregnating agents for textile, paper and leather whilst the latter (Vinoflex MP 400) has found use in surface coatings. 

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