Polyester laminate

TrialkylPhosphates. Triethyl phosphate [78-40-0] C H O P, is a colorless Hquid boiling at 209—218°C containing 17 wt % phosphoms. It may be manufactured from diethyl ether and phosphoms pentoxide via a metaphosphate intermediate (63,64). Triethyl phosphate has been used commercially as an additive for polyester laminates and in ceHulosics. In polyester resins, it functions as a viscosity depressant as weH as a flame retardant. The viscosity depressant effect of triethyl phosphate in polyester resins permits high loadings of alumina trihydrate, a fire-retardant smoke-suppressant filler (65,66). 

Thermoformed acryHc sheet is displacing gel coats in some bathtub appHcations spas have converted almost exclusively to formed acryHc sheet reinforced with glass-reinforced polyester laminations due to higher temperatures and higher stmctural requirements. 

Interesting developments were also taking place in the field of thermosetting resins. The melamine-formaldehyde materials appeared commercially in 1940 whilst soon afterwards in the United States the first contact resins were used. With these materials, the forerunners of today s polyester laminating resins, it was found possible to produce laminates without the need for application of external pressure. The first experiments in epoxide resins were also taking place during this period. 

As laminating resins in competition with polyester laminating resins. 

Laminating resins have been offered by Akzo (Diacryl 101), Dow (Derakane Vinyl Esters) and Showa (Spilac). Typical of these is Diacryl 101, which is manufactured by esterification of the addition product of ethylene oxide to bis-phenol A with methacrylic acid. They exhibit lower curing shrinkage than the polyester laminating resins during cure. The structure of Diacryl 101 is... 

In addition to the polymers, copolymers and alloys already discussed, styrene and its derivatives have been used for the polymerisation of a wide range of polymers and copolymers. Two of the more important applications of styrene, in SBR and in polyester laminating resins, are dealt with in Chapters 11 and 25 respectively. 

Other polyamides produced experimentally include polymers with active lateral groups (hydroxy, keto groups etc.), polymers with heteroatoms (sulphur and oxygen) in the polyamide-forming intermediates, polymers with tertiary amino groups in the main chain and polymers with unsaturation in the main chain. There does not, however, appear to have been any serious attempt to develop unsaturated polyamide analogues to the polyester laminating resins. 

At about the same time, an allyl resin known as CR39 was introdueed in the United States as a low-pressure laminating resin. This was followed in about 1946 with the introduction of unsaturated polyester laminating resins which are today of great importance in the manufaeture of glass-reinforced plasties. Alkyd moulding powders were introduced in 1948 and have since found specialised applications as electrical insulators. 

Figure 25.1. The nature of cured polyester laminating resins.

For some years there has been concern at the amount of styrene vapour in workshops preparing reinforced polyester laminates. More recently this has increased interest in polyester-polyurethane hybrids and in the further development of closed moulding and resin transfer moulding techniques as well as greater use of lower styrene levels. 

This monomer has been used as the basis of a laminating resin and as a reactive diluent in polyester laminating resins, but at the present time its principal value is in moulding compositions. It is possible to heat the monomer under carefully controlled conditions to give a soluble and stable partial polymer in the form of a white powder. The powder may then be blended with fillers, peroxide catalysts and other ingredients in the same manner as the polyester alkyds to form a moulding powder. Similar materials may be obtained from diallyl isophthalate. 

About half of epoxide resin production is used for surface coating applications, with the rest divided approximately equally between electronic applications (particularly for printed circuit boards and encapsulation), the building sector and miscellaneous uses. In tonnage terms consumption of epoxide-fibre laminates is only about one-tenth that of polyester laminates, but in terms of value it is much greater. 

Styrene Polyester laminates, styrene-butadiene acrylics Polarography [509]... 

Suzuki, Y., Maekawa, Z., Hamada, H., Yokoyama, A. and Sugihara, T. (1993). Influence of silane coupling agents on interlaminar fracture in glass fiber fabric reinforced unsaturated polyester laminates. J. Mater. Sci. 28, 1725-1723. 

Haysite Polyester laminates Synthane-T aylor/Haysite... 

Property Nylon Polypropylene Phenolic (Laminate) Polyester (Laminate)... 

Figure 8.6 Thermal diffusion through a 6-mm-thick glass/polyester laminate with and without cure reaction...

The Bjorksten organization was given a contract by the U.S. Air Force about 1949 (AFTR 6220) to explore the effect of glass fabric treatments on polyester laminate wet strength properties. A total of 2000 compounds were screened. The best of these, and still good by today s standards, was a nonaqueous solvent treatment (BJY) based on an equimolar adduct of vinyl trichlorosilane and /3-chloroallyl alcohol [3]. 

Polyester laminate strength data obtained by the Bjorksten group using their BJY treatment are shown in Fig. 1. Fiberglass treatments with DuPont s hydro-phobic chrome complex (Volan 114) and no treatment (112) are also shown for comparison. 

Figure 1. Wel-strength retention of fiberglass-polyester laminates with finishes of 1950 on the glass, from Bjorksten and Yaeger [3].

Figure 2. Polarity of non-reactive and reactive silanes related to their performance on fiberglass in polyester laminates after 2 h water-boil.

Decorative laminate is defined in ISO 472 but in common usage has come to mean sheet materials consisting of decorative surface papers impregnated with melamine resin and consolidated under heat and pressure with plies of core paper permeated with phenolic resin. In a wider sense the term can be applied to many associated products—including laminates in solid colour laminates with facings such as metal foils, textiles, or wood veneers polyester laminates direct faced boards and composite boards comprising thin laminates bonded to substrates of various kinds. 

The relationship between the hardness of a surface and its resistance to scratching is evident (and, by analogy, polyester laminates can be scratched more easily than melamine)—but scratch resistance is influenced also by surface finish and colour. In general, scuff and scratch marks are more obvious on plane finishes (whether glossy or matt) and on dark colours than on textured finishes and light colours. Figure 62 illustrates this relationship. 

Flame-retardant postforming laminates are slightly less pliable and for these the minimum radius recommended normally is 15 mm. On the other hand, polyester laminates are more flexible than melamine and very tight bends can be obtained in these without cracking or crazing of the surface. 

Processed meat products Polyethylene bag within a printed cartonboard box Polyethylene/printing inks/polyester laminate Printed polyethylene to which a printed sticky label was applied Polypropylene container to which a printed sticky label was applied with a polystryrene lid... 

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