摘要:
Paper, board and cardboard are produced by draining paper stock containing interfering substances in the presence of fixing agents by a process in which the fixing agents used are reaction products which are obtainable by reacting amino- and/or ammonium-containing polymers selected from the group consisting of the polymers containing vinylamine units polyalkylene polyamines polyamidoamines ethyleneimine-grafted polyamidoamines which may be crosslinked, polydiallyldimethylammonium chlorides polymers containing dialkylaminoalkylacrylamide units or dialkylaminoalkylmethacrylamide units and polyallylamines and dicyandiamide and formaldehyde condensates with reactive sizes for paper in a weight ratio of polymer to reactive size of from 15,000:1 to 1:1, and the reaction products thus obtainable are used as fixing agents for water-soluble and for water-insoluble interfering substances in the production of paper, board and cardboard from paper stocks containing interfering substances.
摘要:
A process for fractionating water-soluble or water-dispersible amino-containing synthetic polymers having a broad molar mass distribution by ultrafiltration, wherein the polymer solution or dispersion to be fractionated is fed continuously into an ultrafiltration circulation with at least one ultrafiltration unit, and retentate having a narrower molar mass distribution and permeate are discharged continuously, in such a way that the ultrafiltration circulation is essentially in a steady state, the polymers obtainable by this process and their use.
摘要:
A paper size which comprises a stable aqueous dispersion of a reactive size, from 5 to 100% by weight, based on the reactive size, of a substantially linear nitrogen-comprising polymer having at least 3 mmol/g of basic nitrogen atoms, and from 1 to 50% by weight of cationic starch having a degree of substitution of at least 0.05 is described. The paper size has a good sizing effect and a stable viscosity.
摘要:
Aqueous dispersions of reactive sizes comprise cationic polymers comprising vinylamine units as a protective colloid, the protective colloid comprising less than 0.0001% by weight, based on the protective colloid, of diketenes.
摘要:
A paper size which comprises a stable aqueous dispersion of a reactive size, from 5 to 100% by weight, based on the reactive size, of a substantially linear nitrogen-comprising polymer having at least 3 mmol/g of basic nitrogen atoms, and from 1 to 50% by weight of cationic starch having a degree of substitution of at least 0.05 is described. The paper size has a good sizing effect and a stable viscosity.
摘要:
Aqueous dispersions of reactive sizes comprise cationic polymers comprising vinylamine units as a protective colloid, the protective colloid comprising less than 0.0001% by weight, based on the protective colloid, of diketenes.
摘要:
The invention relates to a process for producing polyester polyols with secondary hydroxyl end groups, including the step of the reaction of a polyester including carboxyl end groups with an epoxide of the general formula (1): wherein R1 stands for an alkyl residue or an aryl residue and the reaction is carried out in the presence of a catalyst that includes at least one nitrogen atom per molecule. The process is distinguished in that the polyester including carboxyl end groups exhibits an acid value from ≧25 mg KOH/g to ≦400 mg KOH/g and a hydroxyl value from ≦5 mg KOH/g and in that the polyester including carboxyl end groups is produced by ≧1.03 mol to ≦1.90 mol carboxyl groups or carboxyl-group equivalents of an acid component being employed per mol hydroxyl groups of an alcohol. The polyester polyols obtained, including secondary hydroxyl end groups, can be used for the purpose of producing polyurethane polymers.
摘要:
The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound and by reaction of a calcium compound with a silicon dioxide containing component under alkaline conditions, in both cases the reaction being carried out in the presence of a polycondensate containing at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing a polyether side chain and at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing at least one phosphoric acid ester group and/or its salt. The invention concerns a composition of calcium silicate hydrate and the polycondensate, its use as hardening accelerator and for the reduction of the permeability of hardened compositions.
摘要:
The invention relates to a process for the preparation of polyether polyols with equivalent molecular weights of from 8,000 to 20,000 g/mol from one or more H-functional starter compounds and one or more alkylene oxides in the presence of a double metal cyanide catalyst, characterized in that the alkylene oxides are metered into the reactor in the course of from 15 to 23 h.
摘要:
The present invention relates to is coupling process for the preparation of polyether polyols starting from highly functional starter compounds that are solid or highly viscous under reaction conditions and monofunctional starter compounds that are liquid under reaction conditions with Zerewitinoff-active hydrogen atoms.