EP 0282761 B1 19920513 - PROCESS FOR PRODUCING PAPER AND BOARD HAVING A HIGH DRY STRENGTH
Title (en)
PROCESS FOR PRODUCING PAPER AND BOARD HAVING A HIGH DRY STRENGTH
Publication
Application
Priority
DE 3706525 A 19870228
Abstract (en)
[origin: US4818341A] Paper and paperboard of high dry strength are produced by adding a dry strength enhancer to the paper stock and dewatering the paper stock with sheet formation by using as the dry strength enhancer a mixture of a cationic polymer which contains as characteristic monomers copolymerized units of (a) diallyldimethylammonium chloride, (b) N-vinylamine or (c) a substituted or unsubstituted N-vinylimidazoline and has a K value of not less than 30, and natural potato starch which is converted into a water-soluble form by heating in an aqueous medium at above the gelatinization temperature of natural potato starch in the absence of any oxidizing agents or alkali.
IPC 1-7
IPC 8 full level
D21H 17/28 (2006.01); D21H 17/29 (2006.01); D21H 17/34 (2006.01); D21H 17/37 (2006.01); D21H 17/45 (2006.01); D21H 17/56 (2006.01); D21H 21/18 (2006.01)
CPC (source: EP KR US)
D21H 5/2664 (2013.01 - KR); D21H 17/28 (2013.01 - EP US); D21H 17/29 (2013.01 - KR); D21H 17/455 (2013.01 - EP US); D21H 17/45 (2013.01 - EP US); D21H 21/18 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE ES FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0282761 A1 19880921; EP 0282761 B1 19920513; AT E76135 T1 19920515; AU 1234388 A 19880901; AU 591380 B2 19891130; CA 1290508 C 19911015; DE 3706525 A1 19880908; DE 3870941 D1 19920617; DK 101788 A 19880829; DK 101788 D0 19880226; DK 168640 B1 19940509; ES 2030776 T3 19921116; FI 880836 A0 19880223; FI 880836 A 19880829; FI 89730 B 19930730; FI 89730 C 19931110; JP 2642384 B2 19970820; JP S63227895 A 19880922; KR 880010192 A 19881007; KR 960003188 B1 19960306; NO 171173 B 19921026; NO 171173 C 19930203; NO 880856 D0 19880226; NO 880856 L 19880829; NZ 223534 A 19891027; US 4818341 A 19890404
DOCDB simple family (application)
EP 88102520 A 19880220; AT 88102520 T 19880220; AU 1234388 A 19880226; CA 559242 A 19880218; DE 3706525 A 19870228; DE 3870941 T 19880220; DK 101788 A 19880226; ES 88102520 T 19880220; FI 880836 A 19880223; JP 4242188 A 19880226; KR 880002117 A 19880227; NO 880856 A 19880226; NZ 22353488 A 19880216; US 15550388 A 19880212