초록 ▼

The object of the invention is to provide a stampable sheet of reinforced thermoplastic material, the sheet being composed of a plurality of layers of polyester material and a plurality of layers of reinforcing material integrally formed together, the central layer or layers of polyester material be

The object of the invention is to provide a stampable sheet of reinforced thermoplastic material, the sheet being composed of a plurality of layers of polyester material and a plurality of layers of reinforcing material integrally formed together, the central layer or layers of polyester material being of more slowly crystallizing material than the outer layers. The polyester layers are all substantially amorphous and are made of polyester polymers selected from poly(ethylene terephthalate), selected copolymers of poly(ethylene terephthalate), poly(1,4-cyclohexylenedimethylene terephthalate), selected copolymers of poly(1,4-cyclohexylenedimethylene terephthalate), blends of poly(ethylene terephthalate) and any of the aforementioned selected copolymers, and blends of poly(1,4-cyclohexylenedimethylene terephthalate) and any of the aforementioned selected copolymers, The central polyester layer or layers are polyester polymers selected from the aforementioned selected copolymers and blends. Another object of the invention is to provide a stamped sheet from the stampable sheet of reinforced thermoplastic material, the stamped sheet having a heat deflection temperature under 264 psi. load greater than Tm -50°C.

대표청구항 ▼

A stampable sheet of reinforced thermoplastic material, said sheet comprising a plurality of layers of polyester material and a plurality of layers of reinforcing material integrally formed together, the central layer or layers of polyester material being of more slowly crystallizing material than t

A stampable sheet of reinforced thermoplastic material, said sheet comprising a plurality of layers of polyester material and a plurality of layers of reinforcing material integrally formed together, the central layer or layers of polyester material being of more slowly crystallizing material than the outer layers; said polyester layers being substantially amorphous and made of polyester polymers selected from the group consisting of a. poly(ethylene terephthalate); b. copolymers of poly(ethylene terephthalate) having about 5 to about 50 mole percent of 1,4-cyclohexanedimethanol, neopentyl glycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, bisphenol A, isophthalic acid or 1,4-cyclohexanedicarboxylic acid; c. poly(1,4-cyclohexylenedimethylene terephthalate); d. copolymers of poly(1,4-cyclohexylenedimethylene terephthalate) having about 20 to about 50 mole percent of ethylene glycol, neopentyl glycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, bisphenol A, isophthalic acid, or 1,4-cyclohexanedicarboxylic acid; e. blends of poly(ethylene terephthalate) with greater than 35 weight percent of any of said copolymers in item (b) or item (d); and f. blends of poly(1,4-cyclohexylene dimethylene terephthalate) with greater than 35 weight percent of any of said copolymers in item (b) or item (d); said outer polyester layers having a minimum crystallization half-time upon heating of one minute or less, and said central polyester layer or layers being selected from the polymers identified in items b, d, e or f above and having a minimum crystallization half-time upon heating of greater than one minute, the minimum crystallization half-time being that as measured with respect to each individual layer of said polyester material.