Papermaking additives and mechanical pulp with primary amino groups
AssigneePulp and Paper Research Institute of Canada
InventorsMiroslav Antal, Makhlouf Laleg, Ivan Ignac Pikulik
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Abstract
A graft polymer comprises a carbohydrate polymer having pendant 3-amino-2-hydroxy propyl groups grafted thereon and may be employed as a retention aid and strengthening additive in paper manufacture. When the carbohydrate polymer is a component of wood pulp the resulting chemically modified wood pulp may be employed in conjunction with unmodified wood pulp to incorporate therein the retention and strengthening characteristics.
Claims24
A retention aid and strength additive for use in pulp and paper manufacturing consisting essentially of a graft polymer of formula (I):
- wherein Carbo represents a carbohydrate polymer, in an aqueous vehicle.
A retention aid and strength additive for use in pulp and paper manufacturing comprising a graft polymer of formula (I),
- wherein Carbo represents lignocellulose, in an aqueous vehicle.
A chemically modified wood pulp represented by formula (X):
- and comprising pulp fibres having pendant 3-amino-2-hydroxy propyl groups, grafted on polysaccharides in the pulp fibres, wherein Pulp-O- represents a grafting site on the pulp fibres.
A wood pulp comprising pulp fibres and a graft polymer of formula (I);
- wherein Carbo represents a carbohydrate polymer, as a retention aid and strength additive, said graft polymer being the sole graft polymer.
In a method of manufacturing a paper sheet from a wood pulp in which a retention aid or strength additive is incorporated in the pulp, the improvement wherein the retention aid or strength additive consists essentially of a graft polymer of formula (I):
- wherein Carbo represents a carbohydrate polymer.
In a method of manufacturing a paper sheet from a wood pulp, the improvement comprising incorporating in said wood pulp a chemically modified wood pulp represented by formula (X):
- and comprising pulp fibres having pendant 3-amino-2-hydroxy propyl groups, grafted on polysaccharides in the pulp fibres, wherein Pulp-O- represents a grafting site on the pulp fibres.
A process for producing a carbohydrate polymer of formula (I):
- wherein Carbo represents a carbohydrate polymer as a sole graft polymer, comprising:
- i) reacting a carbohydrate polymer with a compound of formula (II):
- wherein Y is a leaving group to produce a graft polymer represented by (III):
- wherein Y is as defined above and Carbo represents the carbohydrate polymer, in an aqueous medium in the presence of an acid as catalyst, at a pH of 2.5-5.0, at a weight ratio of 20 to 200 g of said compound of formula II per kg of said carbohydrate polymer and
- ii) converting the 3-Y of the polymer (III) to 3-NH2 at an alkaline pH.
Dependencies are inferred from the claim text.