Oxidized polymeric carbohydrates and products made thereof

• US 20040010137A1
• Filed: 05/14/2003
• Published: 01/15/2004
• Est. Priority Date: 11/08/1999
• Status: Active Grant

• Current Assignee: SCA Hygiene Products GmbH (Essity AB)
• Original Assignee: SCA Hygiene Products GmbH (Essity AB)
• Inventors: Bragd, Petter, Jaschinski, Thomas, Besemer, Arie Cornelis, Gunnars, Susanna
• Granted Patent: US 6,987,181 B2
• Time in Patent Office: Days
• US Class Current: 536/56
• CPC Class Codes: C08B 15/02 Oxycellulose; Hydrocellulose; Cellulosehydrate, e.g. microcrystalline cellulose
• CPC Class Codes: C08B 31/18 Oxidised starch
• CPC Class Codes: C08B 37/00 Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof cellulose D21; microbiological processes C12P
• CPC Class Codes: D21C 9/005 organic compounds
• CPC Class Codes: D21H 11/20 Chemically or biochemically modified fibres
• CPC Class Codes: D21H 17/28 Starch
• CPC Class Codes: D21H 21/20 Wet strength agents

Abstract

The present invention relates to a polysaccharide having functional groups, wherein said groups are aldehyde groups formed at positions C2 and/or C3 as well as at position C6 of the anhydroglucose units of the polysaccharide chain. Preferably the polysaccharide is a cellulosic fibrous material whose primary and secondary hydroxyl groups of the cellulose are oxidized into aldehyde groups at least in part by means of TEMPO oxidation and periodate oxidation.

The invention also concerns a paper or nonwoven comprising the above polysaccharide. According to the invention a relative wet strength of more than 10% can be achieved.

Claims

1. A cellulosic fibrous material comprising a polysaccharide-based with functional groups, wherein said groups are aldehyde groups formed at positions C2 and/or C3 as well as at position C6 of anhydroglucose units of the polysaccharide chain.

2. The cellulosic fibrous material according to claim 1, comprising aldehyde groups formed at positions C2, C3 and C6 of the anhydroglucose units of the polysaccharide chain.

3. The cellulosic fibrous material according to claim 1, wherein two secondary OH groups and the primary OH group of an anhydroglucose unit of a polysaccharide chain comprise a plurality of consecutive anhydro sugar units not oxidized into aldehyde groups, but a partial oxidation has taken place.

4. The cellulosic fibrous material according to claim 1, wherein said polysaccharide-based composition comprises secondary hydroxyl groups and are oxidized into aldehyde groups at least in part by means of TEMPO oxidation and periodate oxidation.

5. The cellulosic fibrous material according to claim 1, wherein said polysaccharide based composition comprises starch whose primary and secondary hydroxyl groups of the polysaccharide chain are oxidized into aldehyde groups at least in part by means of TEMPO oxidation and periodate oxidation.

6. The cellulosic fibrous material according to claim 1, wherein said cellulosic fibrous material is in the form of tissue paper.

7. The cellulosic fibrous material according to claim 1, wherein said cellulosic fibrous material is in the form of pulp.

8. The cellulosic fibrous material according to claim 1, wherein the total number of aldehyde groups is 1.5 times greater than the total number of carboxyl groups.

9. The cellulosic fibrous material according to claim 1, wherein the total number of aldehyde groups is more than 50 μ

mol alegehyde/g.

10. The cellulosic fibrous material according to claim 1, wherein the total number of aldehyde groups is more than 75 μ

mol alegehyde/g.

11. The cellulosic fibrous material according to claim 1, wherein the total number of aldehyde groups is more than 100 μ

mol alegehyde/g.

12. A method for making a cellulosic fibrous material, comprising:

oxidizing said cellulosic fibrous material in order to generate aldehyde functions at position C6 of a cellulosic chain within the material,

filtering off and washing the oxidized cellulosic fibrous material, and

oxidizing said celluosic fibrous material in order to generate aldehyde functions at position C2 and/or C3 of a cellulosic chain within the material, and

wherein said cellulosic fibrous material comprises a polysaccharide-based composition with functional groups, wherein said groups are aldehyde groups formed at positions C2 and/or C3 as well as at position C6 of an anhydroglucose units of the polysaccharide material.

13. The method according to claim 12, wherein in the step of oxidizing the cellulosic fibrous material in order to generate aldehyde functions at position C6 of a cellulosic chain within the material, the oxidation occurs by means of 4-hydroxy-TEMPO or 4-Acetamido-TEMPO in an amount of 0.5 to 10.0 wt % based on the dry weight of the fibrous material, in the presence of NaOCl in an amount of 0.1 to 5 wt %, based on the dry weight of the fibrous material.

14. The method according to claim 12, wherein the oxidizing step is conducted at a ph of 2 to 10 and at a temperature of 5 to 60°

C.

15. The method according to claim 12, wherein in the step of oxidizing the cellulosic fibrous material in order to generate aldehyde functions at positions C2 and/or C3 of a cellulosic chain within the material, the oxidation occurs by means of sodium periodate in an amount of 1 to 25 wt %, based on a dry weight of the fibrous material.

16. The method according to claim 15, wherein the oxidizing step is conducted at a pH of 2 to 6 and a temperature of 10 to 60°

C.

17. The method according to claim 12, wherein in the step of oxidizing the cellulosic fibrous material in order to generate aldehyde functions at position C6 of a cellulosic chain within the material, the oxidation occurs by means of 4-hydroxy-TEMPO or 4-Acetamido-TEMPO.

18. The method according to claim 12, wherein in the step of oxidizing the cellulosic fibrous material in order to generate aldehyde functions at positions C2 and/or C3 of a cellulosic chain within the material, the oxidation occurs by means of sodium periodate

19. A method for making a cellulosic fibrous material, comprising:

oxidizing said cellulosic fibrous material in order to generate aldehyde functions at position C6 of a cellulosic chain within the material, the oxidation occurs by means of 4-hydroxy-TEMPO or 4-Acetamido-TEMPO in an amount of 0.5 to 10.0 wt % based on the dry weight of the fibrous material, in the presence of NaOCl in an amount of 0.1 to 5 wt %, based on the dry weight of the fibrous material.

filtering off and washing the oxidized cellulosic fibrous material, and

oxidizing said celluosic fibrous material in order to generate aldehyde functions at position C2 and/or C3 of a cellulosic chain within the material, the oxidation occurs by means of sodium periodate in an amount of 1 to 25 wt %, based on a dry weight of the fibrous material, and

wherein said cellulosic fibrous material comprises a polysaccharide-based composition with functional groups, wherein said groups are aldehyde groups formed at positions C2 and/or C3 as well as at position C6 of an anhydroglucose units of the polysaccharide material.

20. A method for making a cellulosic fibrous material, comprising:

oxidizing said cellulosic fibrous material in order to generate aldehyde functions at position C (6) of a cellulosic chain within the material,

filtering off and washing the oxidized cellulosic fibrous material, and

oxidizing said celluosic fibrous material in order to generate aldehyde functions at position C(2) and C(3) of a cellulosic chain within the material, and

wherein said cellulosic fibrous material comprises a polysaccharide-based composition with functional groups, wherein said groups are aldehyde groups formed at positions C2, C3 and C6 position of an anhydroglucose unit of the polysaccharide material.