| 摘要 |
1368387 Pre-pasted wallcoverings A E STALEY MFG CO 20 Dec 1972 [5 May 1972] 58687/72 Heading B2E [Also in Division C3] A remoistenable, prepasted wall covering able to. withstand soaking in water for up to 20 minutes without loss of adhesive strength, being slippable on a substrate surface for up to 10 minutes after application and also being strippable from the said surface after application, the adhesive comprising in combination, 20-40% oxidised starch, 3-10% an ether of cellulose 20-40% predispersed coating clay, 5-10% polyvinyl alcohol, 5-15% monobasic sodium phosphate, 5-15% of a mixture of a sodium salt of sulphonated paraffin wax and paraffin wax, and from 0.3-5% of aqueous glyoxal containing 40% by weight active glyoxal, the percentages being based on total dry weight. Preferably the starch is oxidised yellow dent corn starch and the starch is to be oxidised to an extent which provides a carboxyl range of 0.4-0.8% by weight. Preferably a fungicide is present in the adhesive. Preferably the ether is the methyl ether, but other ethers such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and hydroxypropyl methyl cellulose may be used. Polyvinyl acetate in amount from 1-20% may be present to increase the adhesive properties of the wall covering. The adhesive may be applied by mixing the above materials, with the exception of the aqueous glyoxal, with 180-400 parts water and cooking for at least 15-30 minutes at a temperature of from 185-205‹F, adding the glyoxal, cooking for a further 15-30 minutes at 185-2/5‹F, cooling to 110-180‹F, applying the cooled mixture to the back surface of the wall covering at a temperature of 110-180‹F and drying the adhesive-coated wall covering at a temperature of from 110-300‹F. |
