The gel range of acid-acting delayed-action gelling agents, such as sodium silicofluoride, in latex spread foam compounds which are to be gelled by subjecting them to a preliminary heat treatment prior to drying is substantially broadened by including a water-soluble ammonium or amine sulfamate in the compound. At least 0.5 parts by weight of the sulfamate should be used per 100 parts by weight of dry solids in the starting uncompounded latex. It can be added to the latex at any time before or during the compounding step and it is preferably added with 0.5-1 part of a soap per part of sulfamate and also with sufficient ammonium hydroxide or other ammonia donor compound to maintain the pH of the compounded latex composition at 9.5 or higher.
A manufacturing method for a laminated sheet comprises: coating a backing coating material on a base fabric (A) which is made of a material having a thermal deformation temperature of at least 150.degree. C., the backing coating material comprising (a) a resin aqueous emulsion and (b) 150-170 parts by weight of expandable styrene resin particles per 100 parts by weight of solids of the resin aqueous emulsion (a); stacking a base fabric (B) which is made of a material having a thermal deformation temperature of at least 150.degree. C. on the layer of backing coating material to form a laminate; compressing the laminate from at least one side so as to impregnate base fabric (B) with a portion of the coating material; and expanding the expandable styrene resin particles and drying the resin aqueous emulsion by heating to a temperature which is higher than the softening point of the resin of the expandable styrene resin particles and which is lower than the thermal deformation temperature of base fabrics (A) and (B), thereby expanding the expandable styrene resin particles and forming a foam layer between base fabrics (A) and (B).
The invention relates to a cellular cellulosic wiping material consisting of a cellular cellulosic substrate covered on at least one side with an expanded latex foam obtained from an aqueous latex composition having a viscosity of between 2500 and 3500 mPa.s, measured at 20.degree. C. under 65% humidity, and giving a foam density of between 250 and 400 g/l.
Foam rubber articles may be prepared by shaping foamed latex into the desired configuration and gelling it. The gelled latex may then be cut to the required thickness to provide articles such as cosmetic puffs. The shaping process may use a disposable mold such as a circular polymeric casting or the mold may be permanent, such as glass, passing through a gelling chamber. The process reduces waste for products which has previously been cut from slab foam.
Aqueous polymer dispersions whose polymer is built up of a) at least 50% by weight of butadiene, isoprene or a mixture thereof, b) at least 10% by weight of an ester of (meth)acrylic acid and a C.sub.1 -C.sub.8 -alkanol and c) from 0 to 10% by weight of other comonomers, where the total amount of monomers a) and b) makes up at least 90% by weight of the total amount of monomers, are useful for producing flame-resistant latex foam rubber which contains only hydrates of inorganic salts as flame retardants.
