Patent GB-632786-A (GB)
Title: Process for producing water-insoluble layers on substrata, and the manufacture of preparations suitable therefore
Inventor: LOLKEMA JAN
IPC: C08G12/40
Filed: 1946-05-09
Abstract: To produce a water-insoluble layer on a substratum, e.g. in finishing or sizing textile materials, a solution containing starch or a derivative, together with an aminotriazine and an aldehyde or a precondensate thereof, which may be etherified and/or esterified, and sufficient non-volatile or slightly volatile acid and/or substance which yields acid when heated, to make the pH of the solution at least 5 is applied to the substratum at 40-50 DEG  C.  The solution remains suitable for use for at least two hours at 40-50 DEG  C. and develops during drying the acid reaction necessary for the final condensation.  The term starch or a derivative includes dextrin and ethers and/or esters of starch which still contain free hydroxyl groups.  Suitable starch pastes may be prepared as described in Specification 632,791, [Group IV (c)].  Decomposed cold-swelling starches obtained as described in Specification 601,374, [Group IV (b)], and 632,789 are particularly suitable.  Suitable aminotriozines are melamine and those mentioned in Specification 477,841.  The preferred aldehyde is formaldehyde, paraformaldehyde, trihydroxymethylene or hexamethylenetetramine.  Suitable acids or latent acids mentioned are salts of sulphuric acid esters from alkenes or alcohols, e.g. sodium hexyl sulphate, ammonium salts of acids, e.g. ammonium oxalate, malonic acid, phosphoric acid, tartaric acid or absorbent substances, e.g. bleaching earths, diatomaceous earth or synthetic resins which have been treated with acid and washed to be neutral at normal temperature but acid at raised temperature.  The solution may be buffered, e.g. with a mixture of primary and secondary alkali phosphates.  The compositions may contain inert bonding agents, e.g. china clay or talcum, softening agents, e.g. fat emulsions or finishing oils, water-repellent substances such as paraffin wax or emulsions containing aluminium salts.  The solutions may also be used as adhesives, or binding agents, or as varnishes.  In example 1 soluble starch is gelatinized with boiling water, and hexamethylolmelamine and malonic acid are added.  Bleached cotton yarn is treated at 50 DEG  C. and dried on heated drums; (2) potato starch and hexamethylolmelamine are gelatinized by water and phosphoric acid added.  Bleached cotton is finished with the solution at 50 DEG  C; (3) soluble starch, hexamethylolmelamine and sodium hexyl sulphate are gelatinized with water.  The pH is 7. Bleached cotton is treated at 50 DEG  C. followed by drying and heat treatment at 110 DEG  C.  The other examples are similar.  In example 6 china clay and talcum are added to the composition. Specifications 466,015, 480,316, 527,704 and 622,208 also are referred to.ALSO:To produce a water-insoluble layer on a substratum, e.g. in finishing or sizing textile materials, a solution containing starch or a derivative, together with an aminotriazine and an aldehyde or a precondensate thereof which may be etherified and/or esterified, and sufficient non-volatile or slightly volatile acid and/or substance which yields acid when heated to make the pH of the solution at least 5 is applied to the substratum at 40-50 DEG  C. The solution remains suitable for use for at least two hours at 40-50 DEG  C. and develops during drying the acid reaction necessary for the final condensation.  The term starch or a derivative includes dextrins and ethers and/or esters of starch which still contain free hydroxyl groups.  Suitable starch pastes may be prepared as described in Specification 632,791.  Decomposed cold swelling starches obtained as described in Specification 601,374, [Group IV (b)], or 632,789, are particularly suitable.  Suitable aminotriazines are melamine and those mentioned in Specification 477,841.  The preferred aldehyde is formaldehyde, paraformaldehyde, trihydroxymethylene or hexamethylenetetramine. Suitable acids or latent acids mentioned are salts of sulphuric acid esters from alkenes or alcohols, e.g. sodium hexyl sulphate, ammonium salts of acids, e.g. ammonium oxalate, malonic acid, phosphoric acid, tartaric acid or absorbent substances, e.g. bleaching earths, diatomaceous earth or synthetic resins which have been treated with acid and washed to be neutral at normal temperature but acid at raised temperature.  The solution may be buffered, e.g. with a mixture of primary and secondary alkali phosphates.  The composition may contain inert loading agents, e.g. china clay or talcum, softening agents, e.g. fat emulsions or finishing oils, water repellant substances such as paraffin wax or emulsions containing aluminium salts.  The solutions may also be used as adhesives, or binding agents or as varnishes.  In examples: (1) soluble starch is gelatinised with boiling water, and hexamethylolmelamine and malonic acid are added. Bleached cotton yarn is treated at 50 DEG  C. and dried on heated drums; (2) potato starch and hexamethylolmelamine are gelatinised by water and phosphoric acid added.  Bleached cotton is finished with the solution at 50 DEG  C.; (3) soluble starch, hexamethylolmelamine and sodium hexyl sulphate are gelatinised with water.  The pH is 7. Bleached cotton is treated at 50 DEG  C., followed by drying and heat treatment at 110 DEG  C.  The other examples are similar.  In example (6) china clay and talcum are added to the composition. Specifications 466,015, 480,316, 527,704 and 622,208 also are referred to.