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Paper treatment compositions containing fluorochemical carboxylic acid and epoxidic cationic resin

Paper treatment compositions containing fluorochemical carboxylic acid and epoxidic cationic resin

Abstract

Cellulosic products are sized with treatment compositions prepared from (a) fluoroaliphatic radical-containing carboxylic acid or a salt or hydrolyzable precursor thereof, (b) water-soluble epoxidic cationic resin made by reacting epihalohydrin with ammonia or aminopolymer, and (c) an optional hydrophobic hydrocarbon sizing agent.

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TECHNICAL FIELD

This invention relates to sizing treatment compositions which impart oil and water repellency to cellulosic materials (e.g., paper). In addition, this invention relates to cellulosic materials, and shaped articles made therefrom, which have been treated with such compositions. Also, this invention relates to a method for treating cellulosic materials with such compositions to impart oil and water repellency thereto.

BACKGROUND ART

Various fluorochemical wet pick-up and internal sizing agents for paper treatments are described, for example, in Rengel and Young, "Internal Sizing of Paper and Paperboard," TAPPI monograph series number 33, pps. 170-189 (1971), Colbert, "Fluorochemicals-Fluid Repellency for Non-Woven Substrates," TAPPI, The Journal of the Technical Association of the Pulp and Paper Industry, 59, 9, (September, 1976), Banks, Ed., Organofluorine Chemicals and their Industrial Applications, pps. 231-234 (1979), Schwartz, "Oil Resistance Utilizing Fluorochemicals," TAPPI conference preprint, 1980 Sizing Short Course, Atlanta, Ga., Putnam et al., "Papermaking Additives," Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed., Vol. 16, pps. 812-813, (1981), and U.S. Pat. Nos. 2,809,990, 3,382,097, 3,409,647, 3,901,864, 4,239,915, and 4,302,366.

DISCLOSURE OF INVENTION

The present invention provides, in one aspect, sizing treatment compositions which impart oil and water repellency, at low usage levels, to cellulosic materials (such as paper), said compositions comprising:

(a) fluoroaliphatic radical-containing carboxylic acid or a salt or hydrolyzable precursor thereof, and

(b) water-soluble epoxidic cationic resin comprising a reaction product of epihalohydrin with ammonia or aminopolymer.

The present invention also provides sizing treatment compositions comprising the above components (a) and (b), together with (c) hydrophobic hydrocarbon sizing agent.

In addition, the present invention provides cellulosic materials treated with the above-described sizing treatment compositions, and shaped articles made from such treated cellulosic materials.

Also, the present invention provides a method for treating cellulosic materials to impart oil and water repellency thereto, comprising the step of applying to said cellulosic materials the above-described sizing treatment compositions.

Through the use of the above-described sizing treatment compositions, cellulosic materials can be rendered oil and water repellent at lower sizing treatment composition levels than have been required with previously-utilized sizing treatment compositions.

DETAILED DESCRIPTION

In the practice of the present invention, said carboxylic acid, and the salts and hydrolyzable precursors thereof (viz., component (a) above) contain one or more fluoroaliphatic radicals R.sub.f. Each R.sub.f radical can be the same as or different from other R.sub.f radicals in component (a). R.sub.f is a monovalent, fluorinated, aliphatic, preferably saturated, organic radical having at least three fully fluorinated carbon atoms. Preferably, R.sub.f contains not more than 20 carbon atoms, because such a large radical results in inefficient use of the fluorine content. The skeletal chain of R.sub.f can be straight, branched, or if sufficiently large, cyclic, and can include catenary divalent oxygen atoms or trivalent nitrogen atoms bonded only to carbon atoms. Preferably, R.sub.f is fully fluorinated, but carbon-bonded hydrogen or chlorine atoms can be present as substituents on the skeletal chain of R.sub.f, provided that not more than one atom of either hydrogen or chlorine is present for every two carbon atoms in the skeletal chain of R.sub.f, and further provided that R.sub.f contains at least a terminal perfluoromethyl group. Preferably, R.sub.f has a average of about 6 to 12 carbon atoms.

The fluoroaliphatic radical-containing carboxylic acids or salts contain one or more carboxyl-containing radicals of the formula --COOM where M is hydrogen, an alkali metal, or an ammonium or organoammonium ion. Each COOM radical can be the same as or different from other COOM radicals in component (a). Preferably, M is an ammonium ion.

The hydrolyzable precursors of the fluoroaliphatic radical-containing carboxylic acids include acid halides, acid anhydrides, acid esters, and other precursors which will generate fluoroaliphatic acids or salts upon contact with water. The acid halides contain one or more radicals of the formula --COX where X is a halogen atom (e.g., fluorine or chlorine). The acid anhydrides have the formula (R.sub.f QCO).sub.2 O where R.sub.f is as defined above and Q is as defined below for formula I. The acid esters contain one or more radicals of the formula --COOR.sup.1 where R.sup.1 is a lower (e.g., C.sub.1-4) alkyl radical.

For purposes of brevity, the fluoroaliphatic radical-containing carboxylic acids and the salts and hydrolyzable precursors thereof will sometimes be referred to hereafter collectively as "fluorocarboxylic acids." Preferred fluorocarboxylic acids for use in this invention have the formula:

(R.sub.f).sub.p Q(COOM).sub.q I

wherein:

R.sub.f and M are as defined above;

Q is a carbon-carbon bond or a polyvalent, preferably divalent linking group, for example, a group selected from --O--, --S--, --N<, --CO--, --NR.sup.2 --, --CONR.sup.2 --, --CON<, --SO.sub.2 NR.sup.2 --, --SO.sub.2 N<, --SO.sub.2 --, --C.sub.n H.sub.2n --, --CH.dbd.CH--, --OC.sub.2 H.sub.4 --, --C.sub.6 H.sub.4 --, --C.sub.6 H.sub.3 <, >C.sub.6 H.sub.2 <, --C.sub.6 H.sub.3 Cl--, --C.sub.6 Cl.sub.4 --, heteroaromatic radicals, cycloaliphatic radicals, and the like or combinations thereof, where R.sup.2 is hydrogen or a C.sub.1-4 alkyl radical, and n is 1 to 20;

p is 1 to 3; and

q is 1 to 4;

or is a hydrolyzable precursor of an acid or salt of said Formula I. Representative compounds of formula I include: ##STR1##

Representative hydrolyzable precursors of compounds of Formula I include:

C.sub.6 F.sub.15 COF,

C.sub.8 F.sub.17 COOCH.sub.3,

and

(C.sub.8 F.sub.17 CH.sub.2 CO).sub.2 O.

A preferred subclass of fluorocarboxylic acids for use in this invention has the formula:

R.sub.f SO.sub.2 N(R.sup.3)R.sup.4 COOM II

wherein:

R.sub.f and M are as defined above;

R.sup.3 is hydrogen or a C.sub.1-4 alkyl radical; and

R.sup.4 is a C.sub.1-6 alkylene radical;

or is a hydrolyzable precursor of an acid or salt of said Formula II. In fluorocarboxylic acids of formula II, M is preferably an ammonium ion, R.sup.3 is preferably methyl or ethyl, and R.sup.4 is preferably methylene.

The above-described fluorocarboxylic acids can be prepared by known methods including electrochemical fluorination and telomerization to yield intermediates which are converted to the desired fluorocarboxylic acids by known reactions, e.g., hydrolysis, condensation reactions, or addition reactions. Suitable preparative methods for such fluorocarboxylic acids and intermediates are described, for example, in Guenthner, Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed., Vol. 10, p. 897 (1980) and U.S. Pat. Nos. 2,809,990, 3,382,097, 3,409,647, 3,901,864, 4,020,087, 4,097,642, 4,239,915, and 4,302,366.

The water-soluble epoxidic cationic resins used in this invention (viz., component (b) above) are reaction products of epihalohydrin (e.g., epichlorohydrin) with ammonia or aminopolymers. Preferably, the epoxidic cationic resins are reaction products of epichlorohydrin with aminopolymers. Suitable aminopolymers include (a) addition polymers of N-alkyldiallylamines, (b) condensation polymers of polyalkylene polyamines (e.g., bis(N,N'-3-aminopropyl) piperazine) with cyanamide or dicyandiamide, and (c) condensation polymers of polyalkylene polyamines, cyanamide, or dicyandiamide with dicarboxylic acids (e.g., adipic acid) or esters of dicarboxylic acids. Preferably, the epoxidic cationic resin is the reaction product of epichlorohydrin with a condensation polymer of diethylenetriamine and dicyandiamide.

Said reaction products of epihalohydrin with ammonia or aminopolymers have cationic quaternary nitrogen sites and pendant epoxide groups. If desired, the epoxide groups of the reaction product can be converted to chlorohydrin groups by combining the reaction product with hydrochloric acid. The resulting chlorohydrin-functional reaction product has particularly good storage characteristics. The active epoxide-functional reaction product can be regenerated by the addition of a base (e.g., aqueous sodium hydroxide),or by adding the chlorohydrin-functional reaction product to an alkaline papermaking slurry. For purposes of brevity, said chlorohydrin-functional reaction products will be included hereafter within the definition of said reaction products of epihalohydrin with ammonia or aminopolymers.

Suitable water-soluble epoxidic cationic resins, and preparative methods therefor, are described, for example, in Bates, "Polyamide-Epichlorohydrin Wet-Strength Resin", TAPPI, The Journal of the Technical Association of the Pulp and Paper Industry, 52, 6, (June 1969), in U.S. Pat. Nos. 3,655,506, 3,947,383, 4,240,935, 4,243,481, 4,279,794, and 4,299,654, and in U.K. Patent Specification No. 1,533,434.

Use of the optional hydrophobic hydrocarbon sizing agents (viz., component (c) above) permits a reduction in the amount of components (a) and (b) employed and a reduction in the total cost of the sizing treatment composition. Preferred hydrophobic hydrocarbon sizing agents are cellulose-reactive materials and include (a) alkyl ketene dimers, (b) octadecyl isocyanates, (c) alkenyl succinic anhydrides, and (d) rosin acid anhydrides. Alkyl ketene dimers are most preferred for use in the sizing treatment compositions of this invention. Especially preferred alkyl ketone dimers have the formula: ##STR2## wherein R.sup.5 is a hydrocarbon radical, such as an alkyl radical of at least 8 carbon atoms, a cycloalkyl radical of at least 6 carbon atoms, an aryl radical, an aralkyl radical, or an alkaryl radical. Each R.sup.5 can be the same or different.

Suitable hydrophobic sizing agents are described in Putnam, op. cit., p. 811, Davison, "The Sizing of Paper," TAPPI, The Journal of the Technical Association of the Pulp and Paper Industry, 58, 3, p. 54, (March, 1975), Davis, et al., "A New Sizing Agent for Paper--Alkylketene Dimers," TAPPI, The Journal of the Technical Association of the Pulp and Paper Industry, 39, 1, pp. 21.ltoreq.23 (January, 1956), Dumas, "An Overview of Cellulose Reactive Sizes," TAPPI conference preprint, Sizing Short Course, Chicago, Ill. (1981), U.S. Pat. Nos. 4,240,935, 4,243,481, and 4,279,794, and U.K. Patent Specification No. 1,533,434.

The sizing treatment compositions of this invention can be used in combination with compatible papermaking adjuvants such as natural and synthetic wax emulsions, starch, dextrin, alum, retaining agents, buffering agents, fireproofing agents, fungicidal agents, antistatic agents, dyes, optical bleaching agents, sequestering agents, mineral salts, swelling agents, and fillers such as clay, talc, and titanium dioxide. The sizing treatment compositions of this invention can be used in acidic or alkaline papermaking, with the latter being preferred. Fluorochemical sulfinates are preferably excluded from the sizing treatment compositions of this invention.

The sizing treatment compositions of this invention are applied to paper, paperboard, and other cellulosic materials in the form of solutions, emulsions, or dispersions in a suitable carrier (e.g., aqueous media or a mixture of water and organic solvents) in accordance with known methods. The compositions of the invention can be applied by spraying, padding, immersion, foaming, or by "wet end" (internal) addition. Wet end addition is preferred. For wet end addition, the pulp slurry will generally contain about 1.5.times.10.sup.-4 to 7.5.times.10.sup.-3 percent by weight of each component of the sizing treatment composition, with these amounts being adjusted to provide the desired application level of each component on the cellulosic material to be treated.

Components (a), (b), and optional component (c) can be applied sequentially or as a mixture to cellulosic materials. For wet end addition, component (b) and optional component (c) are preferaably added to the furnish first followed by mixing of the furnish and addition of component (a).

Components (a), (b), and optional component (c) are applied to cellulosic materials in amounts sufficient to provide the desired level of oil and water repellency. In general, these amounts are about 0.03 to 0.3 percent solids on fiber (SOF) of component (a), 0.1 to 1.5 percent SOF of component (b), and 0 to 1.5 percent SOF of optional component (c). Preferred amounts are about 0.08 to 0.14 percent SOF of component (a), about 0.4 to 0.8 percent SOF of component (b), and about 0.05 to 0.1 percent SOF of optional component (c).

Cellulosic materials which have been treated with the sizing treatment compositions of this invention can be formed, using conventional techniques, into paperboard, or into shaped articles such as bags, trays, plates, and the like. The sizing treatment compositions of this invention have particular utility in the manufacture of molded or die-stamped paper plates. ...............