Removal of organic deposits from recycled fibers used for producing paper

Abstract

Paper is made from paper stock containing pulp derived from recycled paper fibers by adding to the paper stock, an effective amount of an additive for reducing the deposition of contaminants, the additive one or more silicon containing material(s) selected from the group of: (i) an epoxy and/or glycidoxy functional silane, and/or hydrolysed or condensation reaction products thereof with water (ii) glycidoxy and/or epoxy functional siloxane and/or hydrolysed or condensation reaction products thereof with water (iii) a quaternary ammonium functional silicone polymer, and/or hydrolysed or condensed reaction products thereof with water and/or (iv) a quaternary ammonium functional silicone polymer cross-linked by an organic epoxide and/or hydrolysed or condensed reaction products thereof with water and/or (v) an amino functional silane and/or an amino functional silicone and/or hydrolysed or condensed reaction products thereof with water and/or (vi) an alkyl functional silane and/or hydrolysed or condensed reaction products thereof with water; The additive is preferably added in an amount of 0.01-10 percent by weight based on the dry weight of the paper stock.

1 . A method of reducing deposition of stickies during the preparation of recycled paper products and in said products, the method comprising the steps of
 (a) pulping a wastepaper stock in an aqueous medium and   (b) processing pulp produced in step (a) to form recycled paper   characterised in that during step (a) and/or step (b) an effective amount of one or more silicon containing material(s) selected from the group of:   (i) an epoxy and/or glycidoxy functional silane, and/or hydrolysed or condensation reaction products thereof with water   (iii) a quaternary ammonium functional silicone polymer, and/or hydrolysed or condensed reaction products thereof with water and/or   (iv) a quaternary ammonium functional silicone polymer cross-linked by an organic epoxide and/or hydrolysed or condensed reaction products thereof with water and/or   (v) an amino functional silane and/or hydrolysed or condensed reaction products thereof with water and/or   (vi) an alkyl functional silane and/or hydrolysed or condensed reaction products thereof with water;   is added and interacts with said stickies in the pulp thereby reducing deposition of said stickies on pulp processing equipment and in the resulting paper product.   
   
   
       2 . A method according to  claim 1  wherein the silicon containing material comprises epoxy or glycidoxy functional silane (i) selected from the group consisting of 3-glycidoxypropyldimethylethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, epoxycyclohexylethyltriethoxysilane, epoxycyclohexylethyltrimethoxysilane, and epoxyhexyltriethoxysilane. 
   
   
       3 . A method according to  claim 2  wherein the epoxy or glycidoxy functional silane (i) is 3-glycidoxypropyltrimethoxysilane. 
   
   
       4 - 5 . (canceled) 
   
   
       6 . A method according to  claim 1  wherein the silicon containing material comprises quaternary ammonium functional silicone polymer (iii) that is prepared by reacting:
 an organic quaternary ammonium compound having epoxide groups or halohydrin groups in its molecule, with   a siloxane having amino groups in its molecule, in the presence of a surfactant, dispersed in an aqueous polar phase.   
   
   
       7 . A method according to  claim 1  wherein the silicon containing material comprises quaternary ammonium functional silicone polymer cross-linked by an organic epoxide (iv), that is prepared by reacting:
 an organic quaternary ammonium compound having epoxide groups or halohydrin groups in its molecule, with   a siloxane having amino groups in its molecule, in the presence of a surfactant and   a crosslinking agent dispersed in an aqueous polar phase.   
   
   
       8 . A method according to  claim 1  wherein the amount of the silicon containing material used for reducing the deposition of stickies is 0.01-10 percent by weight based on the dry weight of the paper stock. 
   
   
       9 . A method according to  claim 8  characterised in that at least two silicon containing materials are utilised for reducing the deposition of stickies and the total amount of the silicon containing materials is in a range 0.01-10 percent by weight based on the dry weight of paper stock. 
   
   
       10 . A method according to  claim 1  wherein the silicon containing material is introduced during the pulping (step (a)). 
   
   
       11 . A method according to  claim 1  wherein the silicon containing material is introduced during the pulp processing (step (b)). 
   
   
       12 . A method according to  claim 11  wherein the silicon containing material is introduced during one or more of the following stages in the pulp processing (step (b)): cleaning, screening, flotation, dispersion, sedimentation, drying and/or dewatering and any other standard pulp processing stages. 
   
   
       13 . A method according to  claim 12  characterised in that the silicon containing material is added in stage (b) at an addition point where sufficient shear mixing is applied to enable interaction between the silicon containing material and stickies such that passivation occurs. 
   
   
       14 . A method according to  claim 1  characterised in that de-inking aids are used for removing the ink during a flotation stage. 
   
   
       15 . A method according to  claim 1  characterised in that water is either pure demineralized water, or process water extracted during de-inking. 
   
   
       16 . A method according to  claim 1  wherein the stickies comprise colloidal, and/or micro- and/or macro-stickies of any size between 0.1 to 1000 μm. 
   
   
       17 . A paper pulp composition derived from wastepaper stock comprising paper fibre and an effective amount, of: a silicon containing material selected from the group of:
 (i) an epoxy and/or glycidoxy functional silane, and/or hydrolysed or condensation reaction products thereof with water   (iii) a quaternary ammonium functional silicone polymer, and/or hydrolysed or condensed reaction products thereof with water and/or   (iv) a quaternary ammonium functional silicone polymer cross-linked by an organic epoxide and/or hydrolysed or condensed reaction products thereof with water and/or   (v) an amino functional silane and/or hydrolysed or condensed reaction products thereof with water and/or   (vi) an alkyl functional silane and/or hydrolysed or condensed reaction products thereof with water;   
   
   
       18 . A paper pulp composition according to  claim 17  wherein the silicon containing material comprises epoxy or glycidoxy functional silane selected from the group consisting of 3-glycidoxypropyldimethylethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, epoxycyclohexylethyltriethoxysilane, epoxycyclohexylethyltrimethoxysilane, and epoxyhexyltriethoxysilane. 
   
   
       19 . A paper pulp composition according to  claim 18  wherein the epoxy or glycidoxy functional silane is 3-glycidoxypropyltrimethoxysilane. 
   
   
       20 . (canceled) 
   
   
       21 . A paper pulp composition according to  claim 17  wherein the amount of the additive in the pulp is 0.01-10% percent by weight based on the dry weight of paper stock. 
   
   
       22 . Paper products made from the paper pulp composition in accordance with  claim 17 . 
   
   
       23 . A method of making paper and/or tissue from paper stock in accordance with  claim 1 . 
   
   
       24 . A paper and/or tissue product obtainable in accordance with the method in  claim 1 . 
   
   
       25 . (canceled)