DE1149899B - Manufacture of flame-retardant molded parts from molding compounds containing halogen-containing polyesters - Google Patents

Description

Manufacture of flame-retardant molded parts from molding compounds containing halogen Polyester contain unfortunately molded parts made from polyester molding compounds are flammable, too if they contain significant amounts of a non-combustible material. These Property restricts their application, e.g. B. for construction purposes. It exists hence a technical need for masses, the molded parts with improved fire resistance result.

There are numerous additives to reduce flammability been incorporated into the masses, but with little success. So are z. B.

Masses with polyesters, the tetrachlorophthalic acid, the hexachloroendomethylenetetrahydrophthalic acid included, known and commercially available.

However, the molded parts to be produced from it must have more than 25010 Contain chlorine to immediately after removal from an oxidizing flame to go out.

One prior proposal relates to a method of making difficult Flammable, chlorine-containing molded parts made from molding compounds made from unsaturated polyester contain cyclic halogen-containing alcohols. As cyclic halogen-containing alcohols 2,2 '- [isopropylidene - bis - (2,6-dichloro - p - phenyleneoxy)] - dialcanols suggested.

The invention now relates to a method for producing flame-retardant molded parts by curing molding compounds containing halogen-containing unsaturated polyesters - produced with 2,2 '- [isopropylbis- (2,6-dihalogen-p-phenyleneoxy)] - dipropanol as dialcohol component -, Polymerizable monomeric compounds and peroxides contain as catalysts and optionally customary accelerators. The process is characterized in that molding compositions are cured which contain polyesters which have been treated with a dialcohol of the general structural formula wherein R denotes hydrogen atoms or low molecular weight alkyl groups and X represents hydrogen atoms or bromine atoms, the amount of the atom-containing polyester being such that the finished molded parts have a bromine content of at least 10 percent by weight.

Other polyhydric alcohols used in the manufacture. the unsaturated Polyesters are used in addition to the bromophenoxyalkanols mentioned above are preferably dialcohols. However, trihydric and polyhydric alcohols can also be used can be used in smaller quantities. The hardeners in the molding compounds are organic Peroxides, e.g. B.

Benzoyl peroxide, methyl ethyl ketone peroxide, tert.

Butyl hydroperoxide. If desired, conventional accelerators, such as cobalt naphthenate, diethylaniline, mercaptans, be present. a) Manufacturing of 4,4'-isopropylidenebis [ß- (2,6-dibromophenoxy) ethanol], on which no protection here What is claimed is a piston with a capacity of 1 liter, which is equipped with a mechanical stirrer, one Gas inlet tube and a reflux condenser was equipped, was charged with: 4,4'-isopropylidene-bis- (2,6-dibromophenol), 1 mole ................ 544 g dipropylene glycol (served as solvent) .. 300 g Benzyl-trimethyl-ammonium chloride 600ioige aqueous solution. . . . 44 ml 500% aqueous potassium hydroxide solution .... . . . 22 g. The charge was heated to 120 ° C and kept at this temperature while ethylene oxide was bubbled through. Than the weight the mixture had increased by 88 g (2 mol), the reaction was terminated. The mixture thus obtained was poured into 6 l of ice water, whereupon the reaction product failed. The solid product was taken up in 3.5 l of benzene and several times with 100% aqueous sodium hydroxide solution extracted. The benzene solution was with Caustic soda spheres were added and left to stand, so that the whole still preserved, not to remove reacted phenolic material, and it was then washed with water. Evaporation of the solution gave -249 g of 4,4'-isopropylidene-bis- [ß- (2,6-dibromophenoxy) ethanol]. After recrystallization from benzene, the product melted at 105 to 106 ° C.

Bromine content: found 50.60 / 0, calculated 50.6%. b) making a unsaturated polyester from 4,4'-isopropylidene-bis- [ß- (2,6-dibromophenoxy) ethanol], No protection is claimed here either. A piston with a capacity of 500 ml, the one with a mechanical stirrer, a thermometer and a gas inlet tube was equipped, was charged with: 4,4'-isopropylidene-bis- [ß- (2,6-dibromophenoxy) ethanol], 0.25 mol ........ 158 g propylene glycol, 0.8 mol ............ 60.9 g maleic anhydride, 1.0 mol ....... 98.1 g The mixture was heated to 175 to 185 ° C under nitrogen, until the desired acid number (about 42) was reached. Before the end of the reaction were 0.06 g of hydroquinone, which was dissolved in a little methanol. added as an inhibitor. The unsaturated polyester thus obtained was light yellow, glassy at room temperature solid and had an acid number of 42.

Example Production of the molding compositions to be hardened according to the invention. This unsaturated polyester (70 parts) is converted into styrene (30 parts) with heating solved.

This solution had a bromine content of 19%.

With 1.5 percent by weight of a benzoyl peroxide catalyst mixed, poured into 2.5 mm (0.1 inch) thick plates and held for 1.5 hours Cured at 70 ° C and then for 31/2 hours at 100 ° C, hard, tough, clear and essentially colorless moldings, which after removal from a oxidizing flame immediately extinguished (ASTM test D 635-56 T).

Moldings which, as stated above, are made from polyester molding compositions for comparison containing 19.6010 chlorine and from tetrachlorophthalic anhydride or which contained 19.4% chlorine and were obtained from 1,4,5,6,7,7-hexachlorobicyclo- (2,2, 1) -5-hepten-2,3-dicarboxylic acid were recovered, burned after taking them out from an oxidizing fallow.

Claims (1)

PATENT CLAIM: Process for the production of flame-retardant molded parts by curing molding compounds, the halogen-containing unsaturated polyester - produced with 2,2 '- [isopropyl-bis- (2,6-dihalogen-p-phenyleneoxy)] - dipropanol as dialcohol component -, polymerizable containing monomeric compounds and peroxides as catalysts and, if appropriate, customary accelerators, characterized in that molding compositions which contain polyesters are cured with a dialcohol of the general structural formula wherein R denotes hydrogen atoms or low molecular weight alkyl groups and X represents hydrogen atoms or bromine atoms, the amount of bromine-containing polyester being such that the finished molded parts have a bromine content of at least 10 percent by weight. Older patents considered: German Patent No. 1 093 555.