Method for producing single-layer or multi-layer paper

    公开(公告)号:US11293143B2

    公开(公告)日:2022-04-05

    申请号:US16757525

    申请日:2018-10-10

    摘要: A method to produce dried single-layer or multi-layer paper is disclosed. The method comprises, for a single-layer paper, preparing and spraying a partially dehydrated first fibrous web with a spray solution or suspension to give a sprayed partially dehydrated first fibrous web, and dehydrating the sprayed partially dehydrated first fibrous web by applying heat to form a dried single-layer paper; or, for a multi-layer paper, preparing and spraying a partially dehydrated layer compound with a spray solution or suspension to form a sprayed layer compound, and dehydrating the sprayed layer compound by applying heat to form a dried multi-layer paper. The spray solution or suspension comprises water and at least one water-soluble polymer P, which is obtained by polymerizing: (i) a monomer of formula H2CCHNHC(0)R1, where R1 is H or C1-C6- alkyl; and (ii) one or more ethylenically unsaturated monomers different from monomer (i).

    METHOD FOR PRODUCING PAPER OR CARDBOARD

    公开(公告)号:US20220033555A1

    公开(公告)日:2022-02-03

    申请号:US17276242

    申请日:2019-09-13

    摘要: Methods for producing paper or cardboard are provided that comprise the steps (A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created, wherein the final polymer A is obtainable by radical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; and hydrolysing the starting polymer V in order to obtain the final polymer A, (B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.

    Polymer and its preparation and use

    公开(公告)号:US09869060B2

    公开(公告)日:2018-01-16

    申请号:US14646026

    申请日:2013-11-20

    申请人: KEMIRA OYJ

    摘要: The present invention relates to a water-soluble cationic acrylamide-based polymer having one or more acetoacetate groups. The invention also relates to a method for producing the water-soluble polymer which comprises polymerizing ethylenically unsaturated monomers in an aqueous phase, wherein the monomers comprise (a) (meth)acrylamide, (b) ethylenically unsaturated cationic monomer, (c) ethylenically unsaturated monomer having one or more acetoacetate groups, and (d) optionally other ethylenically unsaturated monomer. The invention further relates to the use of the water-soluble polymer as a strength agent in the production of paper and board. The invention further relates to a process for producing paper and board which comprises providing an aqueous cellulosic suspension, adding to the suspension water-soluble polymer having one or more ketone groups, and dewatering the obtained suspension. The invention further relates to paper and board comprising the water-soluble polymer of the invention, as well as paper and board produced by the process of the invention.