Inorganic fillers modified with vinyl alcohol polymer and cationic melamine-formaldehyde resin

Claim 2

A modified filler prepared by contacting inert, particulate, mineral filler with aqueous solution of vinyl alcohol polymer and aqueous colloidal dispersion of cationic melamine-formaldehyde resin sequentially, in either order, or concurrently in one step by use of preformed aqueous vinyl alcohol polymer/cationic melamine-formaldehyde interaction product, the weight ratio of vinyl alcohol polymer to cationic melamine-formaldehyde resin being from about 0.3:1 to about 8:1, at a temperature of up to about 100°C for a period of from about 1 minute to about 1 hour, to obtain a filler having adsorbed thereon from about 0.01 to about 3%, based on dry filler weight, of each of vinyl alcohol polymer and cationic melamine-formaldehyde resin.

Claim 3

The modified filler of Claim 1 wherein the vinyl alcohol polymer is selected from the group consisting of polyvinyl alcohol and copolymers of vinyl alcohol with up to about 15 mole percent of other comonomer selected from the group consisting of a-olefins having 2 to 18 carbon atoms, vinyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms, unsaturated mono- or dicarboxylic acids of 3 to 5 carbon atoms, and esters of said unsaturated mono- or dicarboxylic acids wherein the alcohol moiety has 1 to 8 carbon atoms, N-substituted amides of unsaturated monocarboxylic acids, allyl alcohol, allyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms and vinyl halides. 1 or

Claim 4

The modified filler of Claim/2 wherein the filler is selected from the group consisting of silicates, oxides, carbonates and sulfates.

Claim 5

The modified filler of Claim/3 wherein the filler and vinyl alcohol polymer and cationic melamine-formaldehyde resin are contacted with agitation.

Claim 6

The modified filler of any one of Claims 1 to 4 wherein the filler is selected from the group consisting of clay and calcium carbonate. anyone of 1 to

Claim 7

The modified filler of any one Claims 1 to 5 wherein the vinyl alcohol polymer is selected from the group consisting of partially and completely hydrolyzed polyvinyl acetate wherein the extent of hydrolysis is from about 80 to about 100 mole %.

Claim 8

The modified filler of any one Claims 1 to 6 wherein the cationic melamine-formaldehyde resin is trimethylolmelamine which has been oligomerized and made cationic with from about 0.6 to about 1.0 mole hydrochloric acid per mole trimethylolmelamine.

Claim 9

The modified filler of any one of Claims 1 to 7 wherein the filler is contacted with vinyl alcohol polymer and the cationic melamine-formaldehyde resin at room temperature for a period of from about 5 to about 30 minutes. any one of 1 to

Claim 10

The modified filler of any one Claims 1 to 8 wherein the ratio of vinyl alcohol polymer to cationic melamine-formaldehyde resin is from about 0.5:1 to about 2:1.

Claim 11

The modified filler of any one of Claims 1 to 9 wherein from about 0.02 to about 2.5%, based on dry filler weight, of each of vinyl alcohol polymer and cationic melamine-formaldehyde resin is adsorbed on the filler.

Claim 12

In a process for the production of paper having improved strength and other improved properties which process comprises (a) forming an aqueous cellulosic fiber suspension, and (b) forming said aqueous cellulosic fiber suspension into a sheet, the improvement comprising the incorporation of from about 3 to over 30% by weight of the modified filler of any one of Claims 1 to 10 in the paper by adding said modified filler to the aqueous cellulosic fiber suspension or by applying an aqueous slurry or dispersion of said modified filler to the surface of the sheet formed from the aqueous cellulosic fiber suspension.

Claim 13

The process of Claim 11 wherein the amount of modified filler is from about 8 to about 20 % by weight and wherein the vinyl alcohol polymer is selected from the group consisting of polyvinyl alcohol and copolymers of vinyl alcohol with up to about 15 mole percent of other comonomer selected from the group consisting of a-olefins having 2 to 18 carbon atoms, vinyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms, unsaturated mono- or dicarboxylic acids of 3 to 5 carbon atoms, and esters of said unsaturated mono- or dicarboxylic acids wherein the alcohol moiety has 1 to 8 carbon atoms, N-substituted amides of unsaturated monocarboxylic acids, allyl alcohol, allyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms and vinyl halides. 11 or

Claim 14

The process of Claim/12 wherein the vinyl alcohol polymer is selected from the group consisting of partially and completely hydrolyzed polyvinyl acetate wherein the extent of hydrolysis is from about 80 to about 100 mole % and the filler is selected from the group consisting of clay and calcium carbonate. any one of 11 to

Claim 15

The process of/Claim113 wherein the cationic melamine-formaldehyde resin is trimethylolmelamine which has been oligomerized and made cationic with from about 0.6 to about 1.0 mole hydrochloric acid per mole trimeth lolmelamine.

Claim 16

The process of any one of Claims 11 to 14 wherein the weight ratio of vinyl alcohol polymer to cationic melamine-formaldehyde resin is from about 0.5:1 to about 2:1.

Claim 17

Paper of improved wet strength and dry strength composed of cellulose fiber and from about 3 to over 30% by weight of the modified filler of any one of Claims 1 to 10.

Claim 18

The paper of Claim 16 wherein the amount of modified filler is from about 8 to about 20% by weight and wherein the vinyl alcohol polymer is selected from the group consisting of polyvinyl alcohol and copolymers of vinyl alcohol with up to about 15 mole percent of other comonomer selected from the group consisting of a-olefins having 2 to 18 carbon atoms, vinyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms, unsaturated mono- or dicarboxylic acids of 3 to 5 carbon atoms, and esters of said unsaturated mono- or dicarboxylic acids wherein the alcohol moiety has 1 to 8 carbon atoms, N-substituted amides of unsaturated monocarboxylic acids, allyl alcohol, allyl esters of saturated carboxylic acids wherein the acid moiety has up to 18 carbon atoms and vinyl halides.

Claim 19

The paper of Claims 17 wherein the vinyl alcohol polymer is selected from the group consisting of partially and completely hydrolyzed polyvinyl acetate wherein the extent of hydrolysis is from about 80 to about 100 mole % and the filler is selected from the group consisting of clay and calcium carbonate. 16, 17 or

Claim 20

The paper of Claim/18 wherein the cationic melamine-formaldehyde resin is trimethylolmelamine which has been oligomerized and made cationic with from about 0.6 to about 1.0 mole hydrochloric acid per mole trimeth lolmelamine. any one of 16 to

Claim 21

The paper of/ClaimsA9 wherein the weight ratio of vinyl alcohol polymer to cationic melamine-formaldehyde resin is from about 0.5:1 to about 2:1.