US-12624503-B2 - Composition for improving softness of tissue and/or towel products

US12624503B2US 12624503 B2US12624503 B2US 12624503B2US-12624503-B2

Abstract

A composition for improving softness of tissue and/or towel products includes lignocellulosic fibers; water; and a hydrophobic softener that includes the reaction product of: (1) at least one di- and/or poly-amine, (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capper. The reaction product comprises a hydrophobic substitution of at least about 25 mole percent of the hydrophobic end-capper based on a total number of moles of active amine sites of the reaction product. In addition, a method of improving softness of tissue and/or towel products includes combining the lignocellulosic fibers, the water, and the hydrophobic softener; and creating the tissue and/or towel products.

Inventors

Michael A. Evans
Clement L. Brungardt
Patrick R. Kovacs
David A. Gerstenhaber

Assignees

SOLENIS TECHNOLOGIES, L.P.

Dates

Publication Date: 20260512
Application Date: 20230131

Claims (20)

1 . A composition for improving softness of tissue and/or towel products, said composition comprising: A. lignocellulosic fibers; B. water; and C. a hydrophobic softener comprising the reaction product of reactants consisting of: (1) at least one di- and/or poly-amine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capper chosen from a fatty acid, an ester of a fatty acid, a fatty acid chloride, a fatty alkyl halide, an epoxide of a hydrocarbon, a carboxylic acid anhydride of a hydrocarbon, and combinations thereof, any one or more of which has from 4 to about 40 carbon atoms, and wherein the reaction product comprises a hydrophobic substitution of at least about 25 mole percent of the hydrophobic end-capper based on a total number of moles of active amine sites of the reaction product.
2 . The composition of claim 1 wherein the at one least di- and/or poly-amine is chosen from polyalkyleneamines, polyalkyleneimines, and combinations thereof.
3 . The composition of claim 1 wherein the at least one di- and/or poly-amine is chosen from diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), dipropylenetriamine (DPTA), tripropylenetetramine (TPTA), tetrapropylenepentamine (TPPA), pentapropylenehexamine (PPHA), and dihexmethylenetriamine (DHMTA), methylbisaminopropylamine (MBAPA), hexamethylenediamine, and ethylenediamine and combinations thereof.
4 . The composition of claim 1 wherein the at least one di- and/or poly-amine is chosen from polyethylenepolyamines, polyalkylenepolyamines, and combinations thereof.
5 . The composition of claim 1 wherein the at least one di- and/or poly-amine is diethylenetriamine (DETA).
6 . The composition of claim 1 wherein the at least one chain extender is chosen from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecanedioic acid, C36 dimer acids, dimethyl glutarate, diesters thereof, and combinations thereof.
7 . The composition of claim 1 wherein the at least one chain extender is chosen from adipic acid, dimethyl glutarate, and combinations thereof.
8 . The composition of claim 1 wherein the at least one hydrophobic end-capper is the fatty acid having about 12 to about 20 carbon atoms.
9 . The composition of claim 8 wherein the fatty acid is chosen from caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, oleic acid, and combinations thereof.
10 . The composition of claim 8 wherein the fatty acid is chosen from stearic acid, oleic acid, and combinations thereof.
11 . The composition of claim 1 wherein (1), (2), and (3) are reacted in a molar ratio of about (1 to 3):about 1:about (0.9 to 4).
12 . The composition of claim 1 wherein the hydrophobic softener further comprises an imidazoline cyclization adduct of (1), (2), and (3).
13 . The composition of claim 1 that is free of a non-ionic surfactant.
14 . A method of improving softness of tissue and/or towel products, said method comprising the steps of: A. providing lignocellulosic fibers; B. providing water; C. providing a hydrophobic softener; D. combining the lignocellulosic fibers, the water, and the hydrophobic softener; and E. creating the tissue and/or towel products using the combination of the lignocellulosic fibers, the water, and the hydrophobic softener; wherein the hydrophobic softener comprises the reaction product of reactants consisting of: (1) at least one di- and/or poly-amine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capper chosen from a fatty acid, an ester of a fatty acid, a fatty acid chloride, a fatty alkyl halide, an epoxide of a hydrocarbon, a carboxylic acid anhydride of a hydrocarbon, and combinations thereof, any one or more of which has from 4 to about 40 carbon atoms, and wherein the reaction product comprises a hydrophobic substitution of at least about 25 mole percent of the hydrophobic end-capper based on a total number of moles of active amine sites of the reaction product.
15 . The method of claim 14 wherein the step of combining is further defined as combining the water and the hydrophobic softener with the lignocellulosic fibers that are dispersed in process water.
16 . The method of claim 14 wherein the step of combining is further defined as spraying the water and the hydrophobic softener onto the lignocellulosic fibers.
17 . The method of claim 16 wherein the lignocellulosic fibers are in the form of a wet-web of fibers.
18 . The method of claim 16 wherein the lignocellulosic fibers are disposed on a drier.
19 . The method of claim 14 wherein the hydrophobic softener further comprises an imidazoline cyclization adduct.
20 . A method of improving softness of tissue and/or towel products, said method comprising the steps of: A. providing lignocellulosic fibers; B. providing water; C. providing a hydrophobic softener; D. combining the lignocellulosic fibers, the water, and the hydrophobic softener; and E. creating the tissue and/or towel products using the combination of the lignocellulosic fibers, the water, and the hydrophobic softener; wherein the hydrophobic softener comprises the reaction product of reactants consisting of: (1) at least one di- and/or poly-amine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capper chosen from a fatty acid, an ester of a fatty acid, a fatty acid chloride, a fatty alkyl halide, an epoxide of a hydrocarbon, a carboxylic acid anhydride of a hydrocarbon, and combinations thereof, any one or more of which has from 4 to about 40 carbon atoms, wherein the reaction product comprises a hydrophobic substitution of at least about 25 mole percent of the hydrophobic end-capper based on a total number of moles of active amine sites of the reaction product, and wherein the hydrophobic softener further comprises an imidazoline cyclization adduct that is present in an amount of about 5 to about 95 mol % based on a total number of moles of the reaction product.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/267,311, filed Jan. 31, 2022, which is expressly incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure generally relates to a composition for improving the softness of tissue and/or towel products. More specifically, this disclosure relates to use of a particular composition that is free of a non-ionic surfactant, includes a hydrophobic softener that has a high percentage of hydrophobic substitution, and that has improved toxicity profiles. BACKGROUND Softeners are often used to improve the softness and hand-feel of bath, towel, and facial tissue. One of the most widely used tissue softeners is made using a condensation reaction process. First, one mole of diethylenetriamine (DETA) is reacted with 1.5 to 2.0 moles of a fatty acid (e.g. oleic acid, 0.75 to 1.0 equivalents based on the two primary amines present on DETA). The reaction product is a mixture of mono-amides and bis-amides. The process may optionally be adjusted with additional heat and the application of vacuum to drive the intermediate material to cyclize, forming imidazoline moieties. The remaining primary and secondary amines are then reacted with diethyl sulfate (DES) or dimethyl sulfate (DMS) quaternizing agents to form cationic quaternary amines, completing the synthesis. Two aspects of the softener's chemical structure affect its performance. First, a cationic charge on the softener interacts strongly with anionically charged lignocellulosic fibers used to make bath, towel, and facial tissue. This interaction helps retain the softener in the tissue during sheet formation in a wet-end of a paper machine. Second, the reaction with DES tends to lowers the melting point of the final softener, making it easier to emulsify in the tissue mill. Although such products have been commercially successful for many years, the use of diethyl/dimethylsulfate quaternizing agents has come under increased regulatory scrutiny, particularly in California wherein a California Proposition 65 warning is required. Moreover, such products are categorized in GHS Classification Category 1 with regard to aquatic toxicity. Mixtures of mono- and bis-amides formed by the reaction of oleic acid and DETA have been theorized to be effective tissue softeners. Unfortunately, the amides and imidazolines are waxy solids at room temperature which makes them difficult to emulsify in tissue mills. Moreover, only low percent solids emulsions (e.g. 2-3%) can be made even at high emulsification temperatures (e.g. 60-80° C.). Even at low percent solids, such emulsions are stable for less than one day. For these reasons, such compositions are not suitable for use. Accordingly, there remains an opportunity for improvement. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description of the disclosure and the appended claims, taken in conjunction with the accompanying drawings and this background. BRIEF SUMMARY This disclosure provides a composition for improving softness of tissue and/or towel products. The composition includes lignocellulosic fibers; water; and a hydrophobic softener that includes the reaction product of: (1) at least one di- and/or poly-amine, (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capper chosen from a fatty acid, an ester of a fatty acid, a fatty acid chloride, a fatty alkyl halide, an epoxide of a hydrocarbon, a carboxylic acid anhydride of a hydrocarbon, and combinations thereof, any one or more of which has from 4 to about 40 carbon atoms. The reaction product comprises a hydrophobic substitution of at least about 25 mole percent of the hydrophobic end-capper based on a total number of moles of active amine sites of the reaction product. This disclosure also provides a method of improving softness of tissue and/or towel products. The method includes the steps of providing the lignocellulosic fibers; providing the water; providing the hydrophobic softener; combining the lignocellulosic fibers, the water, and the hydrophobic softener; and creating the tissue and/or towel products using the combination of the lignocellulosic fibers, the water, and the hydrophobic softener. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and FIG. 1A is a bar graph showing the results of the surface softness evaluations of Example 1; FIG. 1B is a bar graph showing the results of the deflection evaluations of Example 1; FIG. 1C is a bar graph showing the results of the tensile strength evaluations of Example 1; FIG. 2 is a Table setting forth the compositions and physical properties of Example D; FIG. 3 is a Table setting forth the compositions and physical p