Prepn. of cationic polyamido-amine resins - used to increase dry strength of paper without increasing the wet strength

• Main Authors: PFOHL,SIGBERG,.DR, HAHN,ERWIN,.DR, STREIT,WERNER,.DR
• Format: Patent
• Language: English; German
• Published: 10.04.1980
• Edition: 3
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; IMPREGNATING OR COATING OF PAPER; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G

The resins are prepd. by (a) alkylating at >=15%, (esp. 20-50%) of the sec. N atoms of the polyamido-amine, and (b) reacting the alkylated product with ethylenically unsatd. 3-5C mono- or dicarboxylic acids or their derivs., vinyl sulphonate, acrolein and/or methacrolein at 30-140 degrees C., (pref. 40-120 degrees C). Pref. this reaction is effected with (meth)acrolein. Used to increase the dry strength of paper, without increasing the wet strength. Effective amts. are 0.2-3% calc. on the solid material, added to the fibre suspensions before paper mfr.