EP0080986A2
Expired / Lapsed
EP
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A process for papermaking
Assignee: Nouryon Pulp and Performance Chemicals AB
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Filing: 1982-11-18
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Granted: —
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Expires: 2002-11-18
Abstract
Abstract In making paper from an aqueous papermaking stock, a binder comprising colloidal silicic acid and guar gum is added to the stock for improving the paper or the retention of the stock components so that the polution problems and the amount of valuable substances in the white water are reduced. The guar gum in amphoteric or preferably cationic and may form part of the binder complex in a mixture with cationic starch. The weight ratio of guar gum to Si0 2 or of guar gum plus cationic starch to SiO 2 is between 0.1:1 and 25:1.
Inventors
- 👤 Hans Magnus Larsson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 06:21
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/68; D21H17/20; D21H17/21; D21H17/24; D21H17/31; D21H17/32; D21H23/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
61 words
A papermaking process in which an aqueous paper- making pulp containing cellulosic pulp is formed and dried, characterised by incorporating into the stock prior to the formation of the sheet a binder comprising colloidal silicic acid and cationic or amphoteric guar gum, the weight ratio of guar gum to SiO 2 being between 0.1:1 and 25:1, preferably between 0.25:1 and 12.5:1.
Claim 2
Dependent Claim
61 words
A papermaking process in which an aqueous paper- making pulp containing cellulosic pulp is formed and dried, characterised by incorporating into the stock prior to the formation of the sheet a binder comprising colloidal silicic acid and cationic or amphoteric guar gum, the weight ratio of guar gum to SiO 2 being between 0.1:1 and 25:1, preferably between 0.25:1 and 12.5:1.
Claim 3
Dependent Claim
79 words
The process of claim 1, characterised in that the binder also comprises cationic starch having a degree of substitution of at least 0.01 and at most 0.1, preferably from about 0.01 to about 0.05 - and most preferably from about 0.02 to about 0.04, the cationic starch, the guar ' gum and the colloidal silicic acid being admixed in a weight ratio (cationic starch + guar rubber):(SiO 2 ) of between 0.1:1 and 25:1, preferably between 0.25:1 and 12.5:1.
Claim 4
Dependent Claim
48 words
The process of claim 1 or 2, characterised in that the colloidal silicic acid is provided as a colloidal silicic acid sol having silicic acid particles with a surface area of from about 50 to about 1000 m 2 /g, preferably from about 300 to about 700 m/g.
Claim 5
Dependent Claim
24 words
The process of claim 1, 2 or 3, characterised in that the pH of the stock is maintained between about 4 and about 9.
Claim 6
Dependent Claim
31 words
The process of any one of claims 1 to 4, characterised in that the solids in the binder amount to 0.1-15% by weight, preferably 1.0-15% of the weight of the pulp.
Claim 7
Dependent Claim
26 words
The process of any one of claims 1 to 5, characterised in that the aqueous paper-making stock contains a cellulosic pulp and a mineral filler material.
Claim 8
Dependent Claim
32 words
The process of claim 6, characterised in that the amount of cellulosic pulp in the stock is adjusted to give a finished paper containing at least 50% by weight of cellulosic fibres.
Claim 9
Dependent Claim
38 words
The process of claim 6 or 7, characterised in that the solids in the binder amount to from about 0.5 to 25%, preferably from about 2.5 to 15% by weight, based upon the weight of the mineral filler.
Claim 10
Dependent Claim
56 words
The process of claim 6, 7 or 8, characterised in that the colloidal silicic acid is added to and mixed with the mineral filler prior to incorporating the mineral filler into the stock, and that the guar gum and the cationic starch, if present, are mixed with the mixture of pulp, filler and colloidal silicic acid.
Claim 11
Dependent Claim
72 words
The process of any one of claims 1 to 8, characterised by intermixing in the stock a portion of the colloidal silicic acid, thereafter intermixing the guar gum and the cationic starch, if present, in the stock containing in the initial portion of collodial silicic acid, and, after an agglomerate has formed, adding and intermixing the remainder of the collodial silicic acid in the stock prior to the formation of the sheet.
Claim 12
Dependent Claim
53 words
The process of claim 10, characterised in that between about 20 and about 90%, preferably between about 30 and about 80% of the colloidal silicic acid is added to the stock to form an agglomerate, and that the remaining portion of the collodial silicic acid is added after the formation of the agglomerate.
Claim 13
Dependent Claim
102 words
An improved paper product containing cellulosic fibres, preferably in a content of at least 50% by weight of the paper product and characterised by enhanced strength characteristics, wherein the bond between the cellulosic fibres is enhanced by a binder comprising a complex of a colloidal silicic acid and guar gum and possibly also a cationic starch having a degree of substitution of at least 0.01, preferably from about 0.01 to about 0.05 and most preferably from about 0.02 to about 0.04, and wherein the ratio (guar gum + cationic starch):(SiO 2 ) is between 0.1:1 and 25:1, preferably between 0.25:1 and 12.5:1.
Claim 14
Dependent Claim
102 words
An improved paper product containing cellulosic fibres, preferably in a content of at least 50% by weight of the paper product and characterised by enhanced strength characteristics, wherein the bond between the cellulosic fibres is enhanced by a binder comprising a complex of a colloidal silicic acid and guar gum and possibly also a cationic starch having a degree of substitution of at least 0.01, preferably from about 0.01 to about 0.05 and most preferably from about 0.02 to about 0.04, and wherein the ratio (guar gum + cationic starch):(SiO 2 ) is between 0.1:1 and 25:1, preferably between 0.25:1 and 12.5:1.
References Cited (Backward Citations)
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