摘要:
A low viscosity unsaturated polyester resin for making glass fiber reinforced products is described, which comprises an alkyd prepared by esterification of maleic anhydride and/or acid and/or fumaric acid, optionally together with phthalic anhydride and/or acid, with one or more glycols, essentially comprising dipropylene glycol, and further comprises 27-34% by weight (of the total resin) of an ethylenically unsaturated monomer copolymerizable with the alkyd, essentially chosen among styrene and vinyl toluene, the alkyd having a molecular weight/double bond factor between 200 and 360 and an amount of free functional groups between 80 and 100 mg of KOH per g of alkyd inclusive. The products obtainable from said resin by conventional processing techniques are also described. The low viscosity of the resin results in better workability and better behavior of the resin during molding while the mechanical properties of the finished products are very good.
摘要:
A low viscosity unsaturated polyester resin for making buttons is described, which comprises an alkyd prepared by esterification of maleic anhydride and/or acid and/or fumaric acid, optionally together with phthalic anhydride and/or acid and/or adipic, sebacic, azelaic or dodecanedioic acid, with one or more glycols, essentially comprising dipropylene glycol, and further comprises 20-30% by weight of the total resins of an ethylenically unsaturated monomer copolymerizable with the alkyd, essentially chosen among styrene and vinyl toluene, the alkyd having a molecular weight/double bond factor between 300 and 390 and an amount of free functional groups between 80 and 100 mg of KOH per g of alkyd inclusive. The buttons obtainable from said resin are also described. The disc blanks made from said resin have better workability and cause less wear of the tools than those of the prior art and the finished buttons have greater impact strength, and better lustre, greater color stability when exposed to sun light.
摘要:
A process for the preparation of an unsaturated polyester from a glycol and tetrahydrophthalic anhydride, maleic anhydride and/or fumaric acid, suitable for the production of an unsaturated polyester resin rapidly loosing its surface tackiness after cross-linking, and furnishing very flexible materials which are resistant to creasing, is described. The glycol employed has at least two ether bridges regularly alternated with --CH.sub.2 --CH.sub.2 -- groups. The reaction is carried out in such a way as to obtain an alkyd essentially exempt from free tetrahydrophthalic anhydride. The resins thus prepared are adapted to the production of putties free from surface tackiness and having good finishing properties for application by spraying and/or by putty knife.
摘要:
A low viscosity unsaturated polyester resin for making products, optionally reinforced with glass fibers is described, which comprises an alkyd prepared by esterification of maleic anhydride and/or acid and/or fumaric acid in association with isophtalic acid, with one or more glycols, essentially comprising dipropylene glycol, and further comprises 25-40% by weight of the total resin of an ethylenically unsaturated monomer copolymerizable with the alkyd essentially chosen among styrene and vinyl toluene, the alkyd having a molecular weight/double bond factor between 300 and 390 and an amount of free functional groups between 50 and 85 mg of KOH per g of alkyd inclusive. The products obtainable from said resin are also described. The resin behaves better in processing has lower heat development and shrinkage than the comparable prior art resins while the mechanical properties of the finished products are very good.
摘要:
A composition of matter suitable for solidifying radioactive wastes is formed of unsaturated polyester resins comprising a polyester (I) obtained polycondensing (a) maleic anhydride and/or maleic and/or fumaric acid, (b) isophthalic and/or terephthalic acid, (c) neopentylglycol, (d) optionally one or more conventional glycols, wherein the amount of (c) is at least 50% by moles with respect to (c)+(d); another polyester (II) obtained polycondensing (a) maleic anhydride and/or maleic and/or fumaric acid, (b) isopropylidene-bis-(phenylene-oxypropanol-2), (c) optionally one or more conventional glycols, wherein the amount of (b) is at least 50% by moles with respect to (b)+(c); an ethylenically unsaturated monomer (III) capable of copolymerizing with (I) and (II); inhibitors, initiators, accelerators, glass fibers and other conventional additives and fillers the weight ratio of component (I) to (II) being from 100:0 to 20:80.