| 摘要 |
The combustion-resistance of neoprene foam rubber is improved by impregnating it with an aqueous mixture of (1) a water-soluble ureaformaldehyde resin prepared by the reaction of between 1 and 2,5 moles of formaldehyde per mole of urea, (2) 10-40 parts of a dihydroxybenzene per 100 parts of resin, (3) excess formaldehyde not exceeding 15 parts per 100 parts of resin, (4) 10-35 parts of a spumific, the total solids incorporated in 100 parts of foam being from 4-50 parts, and subsequently maintaining the foam at resinifying temperatures. All three dihydroxybenzenes are mentioned. Suitable spumifics are diammonium phosphate, monoammonium phosphate, phosphoric acid, ammonium sulphate and ammonium chloride and mixtures thereof. An accelerator for the further condensation of urea-formaldehyde resins, e.g. 2-methyl-2-aminopropanol hydrochloride or a hydroxyalkylamine hydrochloride may be included. In Example 14, foams of mixtures of (1) neoprene and natural rubber (90/10) and (2) neoprene and styrenebutadiene rubber (95/5) are flameproofed. Specification 772,704 is referred to.ALSO:The combustion-resistance of neoprene foam rubber is improved by impregnating it with an aqueous mixture of (1) a water soluble ureaformaldehyde resin prepared by the reaction of between 1 and 2.5 moles of formaldehyde per mole of urea (2) 10-40 parts of a dihydroxybenzene per 100 parts of resin (3) excess formaldehyde not exceeding 15 parts per 100 parts of resin (4) 10-35 parts of a spurnific, the total solids incorporated in 100 parts of foam being from 4-50 parts, and subsequently maintaining the foam at resinifying temperatures. All three dihydroxybenzenes are mentioned. Suitable spurnifics are diammonium phosphate, monoammonium phosphate, phosporic acid, ammonium sulphate and ammonium chloride and mixtures thereof. The neoprene foam may contain minor amounts of natural rubber or other synthetic rubbers.
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