Aldehyde-modified cellulosic fibers for paper products having high initial wet strength
AssigneeThe Procter & Gamble Company
InventorsDavid Jay Smith, Jimmie Ed Ruth, Jr.
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Abstract
Modified cellulosic fibers are formed by (1) esterifying cellulosic fibers with a 1,2-disubstituted alkene that has at least one carboxylic acid group reactive with cellulosic hydroxyl groups and (2) oxidizing the esterified fibers to form aldehyde groups. The modified fibers are useful in paper products, which tend to have temporary wet strength. Strength additives may be included in the paper product to impart a higher level of temporary wet strength or permanent wet strength.
Claims25
Aldehyde-modified cellulosic fibers prepared by oxidizing the reaction product of (i) cellulosic fibers having hydroxyl groups and (ii) a 1,2-disubstituted alkene having a carboxylic functional group capable of reacting with said hydroxyl groups, wherein in said reaction product at least a portion of said hydroxyl groups are reacted with said carboxylic group of said alkene to form covalent linkages, said reaction product being oxidized to form aldehyde groups.
aldehyde-modified cellulosic fibers, the fibers comprising the oxidation product of esterified cellulosic fibers, said esterified cellulosic fibers comprising cellulosic fibers having hydroxyl groups and a 1,2-disubstituted alkene having a carboxyllc acid group, a portion of said hydroxyl groups being reacted with said carboxylic acid group of said alkene to form ester linkages, said esterified cellulosic fibers being oxidized to form aldehyde groups.
Aldehyde-modified cellulosic fibers, the fibers comprising the oxidation product of esterified cellulosic fibers, said esterified cellulosic fibers comprising cellulosic fibers having hydroxyl groups and a 1,2-disubstituted cyclic alkene having two carboxylic functional groups positioned 1,2 or 1,3 relative to one another, said carboxylic functional groups being selected from the group consisting of carboxylic acid groups and acid amide groups, provided that at least one of said carboxylic functional groups is a carboxylic acid group, the alkene group and said carboxylic functional groups of said alkene being unconjugated, about 0.25 to 1.5 mole %, calculated on a cellulose anhydroglucose molar basis, of said hydroxyl groups being reacted with said carboxylic acid group of said alkene to form ester linkages, said esterified cellulosic fibers being oxidized to form aldehyde groups.
A method of making aldehyde-modified cellulosic fibers, the method comprising the steps of:
- (a) providing (i) cellulosic fibers having hydroxyl groups and (ii) a fluid mixture of a liquid medium and a 1,2-disubstituted alkene having a carboxylic functional group capable of reacting with cellulosic hydroxyl groups;
- (b) contacting the cellulosic fibers with said fluid mixture to form treated fibers;
- (c) reacting a portion of said hydroxyl groups of said cellulosic fibers with said carboxylic functional group of said alkene to form covalent linkages to form intermediate cellulosic fibers;
- and
- (d) reacting said intermediate cellulosic fibers with an oxidizing agent to form aldehyde groups.
Dependencies are inferred from the claim text.