CA1279874C

CA1279874C - Stable emulsifier and substituted succinic anhydride compositions therewith

Info

Publication number: CA1279874C
Application number: CA000465721A
Authority: CA
Inventors: William A. Sweeney
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1983-10-28
Filing date: 1984-10-18
Publication date: 1991-02-05
Anticipated expiration: 2008-02-05
Also published as: FR2554013B1; FR2554013A1; GB2148910A; GB8426818D0; DE3439117A1; GB2148910B; JPS60122035A

Abstract

ABSTRACT OF THE DISCLOSURE
A stable polyethyleneoxy-containing emulsifier and an improved hydrocarbyl-substituted succinic anhydride/emul-sifier composition. There is also disclosed a method for imparting water repellency to surfaces containing groups reactive to anhydrides and a method for the sizing of paper using said composition.

Description

~L~798~

STABLE EMULSIFIER AND SUBSTITUTED
SUCCINIC ANHYDRIDE COMPOSITIONS THEREWITH
05 ACKGROUND OF THE INVE~TION

This invention relates to a stable polyethylene-; oxy-containing emulsifier and an improved hydrocarbyl-substituted succinic anhydride/emulsifier composition.
This invention also relates to an improved method for imparting water repellency to surfaces containing groups reactive to anhydrides. A further aspect of this inven-tion relates to an improved method for the sizing of paper and paperboard products.
It is well known in the art that hydrocarbyl-substituted succinic anhydrides are good for treating paper, fabric, or other surfaces to impart water repellency. As indicated in U.S. Patent Nos. 3,102,064, 3,821,069, 3,968,005, and 4,040,900 (RE 29,960)l these 2 compositions are particularly useful for sizing paper.
It is also known that these succinic anhydrides are best applied for such purposes in a highly dispersed form, such as an aqueous emulsion. See, for example, U.S.
Patent No. 4,040,900 (RE 29,960), which describes paper siæing emulsions made from mixtures comprising a substi-tuted cyclic dicarboxylic acid anhydride and polyoxy-alkylene alkyl or alkylaryl ether or the corresponding mono- or di-ester.
Long-chain diester emulsifiers, as well as mono-esters, alkyl phenol ethoxylates and alcohol ethoxylates, are disclosed in U.S. Patent No. 4,040,900 (RE 29,960) as useful emulsifiers for substituted succinic anhydrides.
A major drawback of these prior art emulsifiers is the fact that, once formed, the succinic anhydride-emulsifier mixtures are unstable and must be promptly used. There therefore exists a need in the art for sub-stituted succinic anhydride-emulslfier mixtures which demonstrate enhanced stability upon aging or storage.

:

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0l -2-SUMMAR~ OF THE_INVENTION
The present invention provides a novel emulsi-S fier of the formula:
R-W t Y-(COOH)mln wherein R is a hydrophobic alkyl, alkylaryl, aryl-alkyl or acyl group containing from 8 to 30 carbon atoms;
W is a water-soluble polyethyleneoxy-containing group 1~ having from 3 to ~0 ethylene oxide units which is indepen-dently connected to R and Y through o~ygen, sulfur or nitrogen linkages;
tY-(COOH)m]n is a capping group for the oxygen, sulfur or nitrogen linkages on W not connected to R, wherein Y contains from l to 9 carbon atoms, provided that no more than 7 carbon atoms are methylene carbons;
m is l or 2;
n is l/3, l/2, l, 2, or 3;
and the hydrophile-lipophile balance (HLB) is between about 9 and 18.
The present invention additionally provides a stable hydrocarbyl-substituted succinic anhydride/emulsi-fier composition comprising:
(A) 70 to 99.5% of a normally liquid hydrocarbyl-substituted succinic anhydride containing from 6 to 50carbon atoms in the substitu0nt; and (B) 0.5 to 30% of the emulsifier described above.
The present invention further provides a method of imparting water repellency to surfaces containing groups reactive to anhydrides which comprises impregnating said surfaces with an aqueous emulsion of the substituted succinic anhydride/emu~sifier composition of the invention.
The present invention is also concerned with a method of sizing paper which comprises intimately dis-persing within the wet paper pulp, prior to the ultimate conversion of said pulp into a dry web, an aqueous emul-sion of the substituted succinic anhydride/emulsifier composition of the invention~

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Among other factors, the present invention is based on my discovery that certain derivatives of poly-05 ethyleneoxy-containing (or "polyethylene glycol-based") emulsifiers, wherein the free hydro~yl groups are capped with small carbon-containing groups, are surprisingly effective emulsifiers upon aging in substituted succinic anhydride. These emulsifiers provide stable mixtures with substituted succinic anhydride and do not react with the anhydride under storage conditions.
Advantageously, the substituted succinic anhy-dride-emulsifier mixtures of the present invention are highly effective in treating various surfaces to impart water-repellency. These compositions are particularly useful as superior paper sizing agents.
DETAILED DESCRIPTION OF THE INVENTION
The hydrocarbyl-substituted succinic anhydride useful for preparing the anhydride/emulsifier composition of the present invention i5 a hydrophobic molecule, Usu-ally it will have one substituent in the 3-position, but it may have substituents in both the 3- and 4-positions.
In general, the substituent will be an alkyl, alkenyl or aralkyl group. Other elements may be present in a minor ~5 amount, such as a sulfur or ether linkage. The total number of carbon atoms in the substituent is between 6 and 50. A preferred substituent size is between 10 and 30.
More preferred is between 12 and 25. A preferred embodi-ment of the contemplated anhydrides is the alkenyl succi-nic anhydride made by allowing an olefin to react with maleic anhydride by the well-known "Ene" reaction. Also suitable i5 the "Diels-Alder" product derived from maleic anhydride and a conjugated diene. For the present pur-poses, I shall refer to the anhydrides contemplated as "ASA".
The emulsifier of the present invention pos-sesses three essential properties. First, it is soluble in ASA at ambient temperatures. Secondly, it is stable to storage when dissolved in ASA. Thirdly, it has surfactant ~ power to emulsify ASA in water. To satisfy these ~.2'79~37~

requirements, the present emulsifier contains no free -SH, -OH or -NH groups which could react with ~SA and it has a 05 hydrophile-lipophile balance (HLB) between about 9 and 18.
Generally, to achieve the desired HLB, the emul-sifiers will contain between about 3 and 80 average moles of ethylene oxide, depending on the size of the lipophilic and other hydrophilic groups present. More commonly, the suitable range of moles of ethylene oxide employed will be from about 5 to 400 The present emulsifier can be prepared from commercially available polyethylene glycol-derived emulsi fiers which contain free hydroxyl groups. These commer-cially available emulsifiers are themselves soluble in ASA
and are effective for emulsifying the anhydride in water.
However, they are not stable in ASA on storage due to the presence of the hydroxyl groups. Examples of this class of hydroxyl-containing compounds are described in U.S.
Patent No. 4,040,900 (RE 29,960) and include the poly-ethylene glycol derivatives of long-chain alcohols, alkyl-phenols and carboxylic acids, which are commonly used to emulsify oils in water. In general, these compounds will contain one free hydroxyl group and can be represented by the following formulae:

CxH2x+l C-(OCH2CH2)Z OH, CXH2 ~ __~OCH2CH2)z OH, CXH2 1 ~0CH2CH2)z- OH, wherein x is an integer from 8 to 24 and z is an integer from 5 to 200 Typical commercial examples of these hydroxyl-containing emulsifiers include Igepal C0-630 (GAF), Triton X-100 (Rohm and Haas), Te~gitol TMN-6 and *Trade Mark -~ - - ~

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Tergitol 15-S-9 (Union Carbide), and PEG 400 mono and dilaurate (Stepan).
05 In addition to the above monohydroxy-containing surfactants, suitable surfactants may contain various hydrophilic moieties familiar to the art. In addition to polyethyleneoxy groups, they may contain glyceryl, poly-glyceryl, anhydrosorbityl or pentaerythrityl groups, and the like. With these compounds more than one hydroxyl group is present which must be capped to form the surfac-tants of the present invention. Small amounts of pro-pyleneoxy groups may also be present. It is not desirable to employ surfactants which possess more than about four hydroxyl groups because of the excessive amount of capping required.
Also contemplated are surfactants in which sul-fur or nitrogen linkages are involved, between the hydro-philic group and either the hydrophobic or the capping group. For example, ethoxylated mercaptans or ethoxylated fatty acid amides can be used. Ethoxylated sulfonamides can also be used.
The hydrophobic moiety may be straight chain, branched or cyclic. It may be alkyl, alkylaryl or aryl-alkyl. It may also include an acyl attachment.
The above-described compounds are converted to the emulsifiers of the present invention by reacting the free hydroxyls with a small carbon-containing reagent which adds a free carboxyl at the same time as it caps, or covers up, the hydroxyls. Generally, the capping group will have only a minor effect on the hydrophile-lipophile balance (HLB) of ;he emulsifier because the free carboxyl group counteracts the effect of the cap on the HLB. One must select the surfactant and capping group to ensure that the capped emulsifier is within the desired HLs range. Enough capping reagent is used to cover up all the reactive -SH, -OH and -NH groups in the surfactant employed.
Suitable capping reagents either contain a free carboxyl group which does not react during the capping *Trade Mark !,"~

~;~79~

0l -6-reaction or contain a nascent carboxyl which is formed during the capping reaction, or both. An exa~ple of the 05 former type is chloroacetic acid which, after reaction, leaves a carboxymethyl capping group. An example of the latter type is succinic anhydride which, after reaction, leaves a carboxypropionyl capping group.
The carboxymethyl type of cap can be added by a 1~ process similar to that described in U.S. Patent No. ~,623,900. This is suitable for making emulsifiers of the present invention but suffers from the disadvantage of forming a sodium chloride byFroductc This capping reac-tion produces an ether linkage to the hydrophilic moiety of the emulsifier. Other stable linkages are also contem-plated. For example, an ester linkage could be formed byreaction of the monoacyl chloride oE a polycarboxylic acid.
Preferred capping reagents are those that form a carboxyl derivative linkage, such as ester, amide, and the like, to the hydrophilic moietyO
While the capping reagents are normally mono-~unctional, they can also be difunctional or even tri-functional, as long as the structural requirements are met proportionately for each functional group.
The cyclic anhydride capping reagents are parti-cularly preferred because they require no catalyst or coreactant and no byproducts are formed. Consequently, no additional processing steps are required. Examples of suitable cyclic anhydrides include maleic, succinic, glutaricr itaconic, citraconic, glutaconic, diglycolic, thiodiglycolic, and the like. Anhydrides from acetyl malic acid or diacetyl tartaric acid are suitable.
Bicyclic anhydrides, such as tetrahydrophthalic and hexa-hydrophthalic, are suitable. The adduct of maleicanhydride with cyclopentadiene is suitable. Dianhydrides such as pyromellitic dianhydride and benzophenone tetra-carboxylic dianhydride are suitable. In this case, both anhydride groups each react with a separate hydroxyl 1~2~987~

01 ~7~

group, so only half the molecule is considered one capping group.
~5 The cyclic anhydride may also contain a pendant carboxyl group before reaction, as in tricarballylic anhydride, aconitic anhydride or acetyl citric anhydride.
In this case, the derived emulsifier of the present inven-tion contains two pendant carboxyl groups for each capping reagent.
In the capping group on the emulsifier, desig-nated ~Y-(COOH)m]n in the formula above, Y will generally contain from 1 to 9 carbon atoms, provided that no more than 7 carbon atoms are methylene carbon atoms. By "methylens" I mean any carbon atom which has at least three bonds attached to hydrogen or to another carbon atom. Therefore, methyl and some methine groups are included in this definition. The capping group should have relatively few methylene carbon atoms, which are lipophilic, so that the hydrophile-lipophile balance (HLB) of the emulsifier is not signi~icantly altered. Carbon atoms taking part in carbon-carbon double bonds are also counted, but as equal to 2/3 of a methylene carbon. Pre-ferably, Y will contain from 1 to 4 carbon atoms. The capping groups derived from the cyclic anhydrides will contain from 4 to 10 carbon atoms per anhydride group, including the pendant carboxyl produced. The smallest cyclic anhydrides contemplated, such as maleic and succinic anhydride, contain 4 carbon atoms. Up to 6 addi-tional carbon atoms may be present, either in theanhydride ring or attached to it. With a dianhydride capping reagent, these numbers may be doubled. Inert groups, such as an ether or thio linkage, may also be present in the cyclic anhydride. For example, diglycolic and thiodiglycolic anhydride are suitable capping reagents. The smaller cyclic anhydrides containing four or five carbon atoms are preferred.
If the capping group contains a reactive func-tion such as the double bond in a maleyl monoester, reac-4~ tions known to the art may be performed with this function ~27~387~

.

as long as the product conforms to the composition of this invention. For example, isomerization of a maleyl mono-05 ester to a fumaryl monoester yields a suitable emulsifier.
: Examples of suitable capping groups on the emul-sifier of the invention include the following:

O O
.. ..
-CH2COOH, -CCH2CH2COOH, -C-CH _ CH--COOH, O O
O O C=O
" - I C=O
--C~ ~COO ~C=C~ , CH3 CH3 15 H~ ~ H H COOH
.
O O O
,. r~ .. ..
--Ct~ 5 ~) , -CCH 2CH 2CH 2COOH, -CCH 2 I HCH 2COOH, ~ COOH
COOH

O O
,. ..
-CCCH 2COOH,-CCH 2OCH 2COOH, O O O
~ ll ll -CCS25CH~COOH, and ~C\

Preferred capping groups include:
O O O O
,. " " ~
-CCH 2CH 2COH , -C~ C C ~ CO and ~ C=C
H~ ~ H H CO~H

~279~374 The hydrophobic/hydrophilic balance of the capped emuIsifiers is in the normal emulsifier-detergent 05 range. One way of defining this balance i5 by the use of the HLB scale (Hydrophile-Lipophile Balance). See P. Becker, Chapter 18, in "Nonionic Surfactants", M. J.
Schick, Editor, Marcel Dekker (1967). The hydrophile-lipophile balance is an indication of the size and strength of the hydrophilic (water-loving or polar) groups, and the lipophilic (oil-loving or non-polar) groups in a surfactant material expressed by a numerical value designated the HLB number. On that scale, for my oil-in-water capped emulsifiers, the HLB should be about 9 to 18, preferably 11 to 16.
The HLB may be estimated by comparison of various properties, such as water solubility, with emulsi-fiers of known HLB. Alternatively, the HLB may be cal-culated by several procedures known to the art. See, for example, J. T. Davies, Second Proceedings International Congress on Surface Activity, page 426 (1957). A simple approach with polyethyleneoxy-containing nonionic com-pounds is to divide the weight percent polyethyleneoxide by five. I have estimated the HLB this way for several emulsi~iers of the present invention by including the weight percent of the pendant carboxyl with the poly-ethyleneoxide~ Very good ASA emulsions in water are obtained when the estimated HLB is in the 11 to 16 range.
The emulsifier of the present invention is pre-pared by reacting the unstable hydroxyl-containing emulsi-fier described above with the capping reagent until thehydro;yl groups have reacted. Generally, from a few minutes to several hours are required for this reaction at temperatures from about 80C to 200C. With esterifica-tion catalysts, lower temperatures and shorter times maybe employed. Before making the ASA/emulsifier composition of the present invention, it is preferable to remove any byproducts which may have been formed, such as sodium chloride or hydrogen chloride. The capped emulsiÇier is ~10 79~37~

- then blended into the ASA, yielding the ASA/emulsifier composition of the invention.
Alternatively, when the capping reagent is sufficiently reactive, the hydroxyl-containing emulsifier may be ~irst dissolved in the ASA and then reacted with the capping reagent.
In addition to the ability to provide stable self-emulsifying mixtures with ASA, the emulsifiers of the present invention possess unusual surfactant properties.
The pendant carboxyl groups can ionize at high pH and can form complexes with metal ions.
The ASA/emulsifier compositions of the present invention comprise 7~ to 99.5 parts by weight, preferably 80 to 98 parts, of the substituted succinic anhydride and 0.5 to 30 parts by weight, preferably 2 to 20 parts, of the capped emulsifier. These ASA/emulsifier combinations are easy to make at a central location and can be stored and shipped to the location where the ASA emulsions will be made. The two components are miscible and the mixture is liquid at ambient temperatures.
This A~A/emulsifier composition readily emulsi-fies into water of various hardness and pH with simple mixing in the absence of high shear. Fine droplets areformed and the emulsion is stable until it is used for treating a surface which contains yroups reactive to the anhydride. The time between formation and use could range from a few seconds to several hours. Longer times are generally not preferred because the anhydride groups will gradually be hydrolyzed by the water present.
The water used can be relatively pure or can contain the usual impurities in domestic water. It can have a pH above or below 7, generally in the range of 3 to ll. Calcium and magnesium hardness ions may be present.
The amount of ASA suspended in the water can vary widely, from a few parts per million to 10% or more depending on the use and method of application. For wood or fabric treatment, concentrations around 1% may be used, whereas for internal paper si~ing, the concentration in 37~

the pump slurry is normally below about 100 parts per million. Thereby about O.l to l~ of ASA is finally absorbed on the paper.
05 Surfaces to be treated with the ASA/emulsifier compositions of the invention to gain w~ter repellency will contain integral groups which are reactive to the ASA
anhydride group. This normally will involve reaction with groups such as hydroxyl, amino or mercapto. A preferred type of material which may be treated with emulsions of the compositions of the invention contains carbohydrate molecules, such as cellulose or starch, at the surface of the material~ These materials contain many hydroxyl groups which can react with the AS~.
As stated above, the ASA/emulsifier compositions of the present invention may be used to impart water repellency to cellulosic materials. The water-repellent compositions described above are preferably applied to the material in aqueous emulsions. The emulsion may be ~ sprayed onto the material or the material may be dipped into the emulsion in order to distribute the derivative evenly throughout the material. The impregnated material is then withdrawn from the solution and air dried. After air drying, the material is then heated, preferab:Ly to a temperature in excess of 100C, to effect a curing of the impregnated agent within the material. It has been found that one may conveniently use a temperature of about 125C
for a period of 15 to 20 minutes. At lower temperatures, longer periods of time are required to effect the curing process. Lower temperatures and shorter times may be used if an acylation catalyst is present. To be commercially practical, the curing time sh,uld be as short as possible and generally less than one hour. At higher temperatures, the heat curing may be accomplished in shorter periods of time. The upper limit of temperature at which the heat curing process may be carried out is limited to the tem-peratures at which the cellulosic material begins to decompose. Using the composition of the present inven-tion, it is preferred to impregnate the material with from ~79~374~

about 0.5 to 3~ by weight of the material of the ASA/emul-sifier composition.
05 The ASA/emulsifier compositions of the present invention may additionally be used as paper sizing agents.
These novel sizing agents display all of the features and advantages of prior art sizing agents. Moreover, the novel sizing agents of this invention impart to paper sized therewith a particularly good resistance to acidic liquids such as acid inks, citric acid, lactic acid etc.
as compared to paper sized with the sizing agents of the prior art. In addition to the properties already men-tioned, these siæing agents may also be used in combina-tion with alum as well as with any of the pigments, fillers and other ingredients which may be added to paper.
The sizing agents of the present invention may also be used in conjunction with other sizing agents so as to obtain additive sizing effects. A still further advantage is that they do not detract from the strength of the paper and when used with certain adjuncts will, in fact, increase the strength of the finished sheets. Only mild drying or curing conditions are required to develop full sizing value.
The actual use of these sizing agents in the manufacture of paper is subject to a number of variations in technique, any of which may be further modified in light of the specific requirements of the practitioner.
It is important to emphasize, however, that with all of these procedures, it is most essential to achieve a uni-form disparsal of the sizing agent throughout the fiberslurry, in the form of minute droplets -hich can come in intimate contact with the fiber surface. Uniform dis-persal may be obtained by adding the sizing agent to the pulp or by adding a previously formed, fully dispersed emulsion. Chemical dispersing agents may also be added to the fiber slurry.
Another important factor in the effective utili-zation of the sizing agents of this invention involves their use in conjunction with a material which is either ~X7987~

~1 -13-cationic in nature or i5, on the other hand, capable of ionizing or dissociating in such a manner as to produce 05 one or more cations or other positively charged moieties.
These cationic agents, as they will be hereinafter referred to, have been found useful as a means for aiding in the retention of sizing agents herein as well as for bringing the latter into close proximity to the pulp fibers. Among the materials which may be employed as cationic agents in the sizing process, one may list alum, aluminum chloride, long chain fatty amines, sodium alumi-nate, substituted polyacrylamide, chromic sulfate, animal glue, cationic thermosetting resins and polyamide poly-mers. Of particular interest for use as cationic agents are various cationic starch derivative~ including primary, secondary, tertiary or quaternary amine starch derivatives and other cationic nitrogen substituted starch deriva-tives, as well as cationic sulfonium and phosphonium starch derivatives. Such derivatives may be prepared from all types of starches including corn, tapioca, potato, waxy maize, wheat and rice. Moreover, they may be in their original granule form or they may be converted to pregelatinized, cold water soluble products.
Any of the above noted cationic agents may be added to the stock, i.e., the pulp slurry, either prior to, along with, or after the addition of the sizing agent.
However, in order to achieve maximum distribution, it is preferable that the cationic agent be added either subse-quent to or in direct combination with the sizing agent.
The actual addition to the stock of either the cationicagent or the sizing agent may take place at any p,int in the paper making process prior to the ultimate conversion of the wet pulp into a dry web or sheet. Thusr for exam-ple, these sizing agents may be added to the pulp whilethe latter is in the headbox, beater, hydropulper or stock chest.
Further improvements in the water resistance of the paper prepared with these novel sizing agents may be obtained by curing the resulting webs, sheets, or molded ~L27~8~g~4 products. This curing process involves heating the paper at temperatures in the range of from 80 to 150C for 05 periods of from 1 to 60 minutes. However, it should again be noted that post curing is not essential to the success-ful operation of this invention.
The sizing agents of this invention may, of course, be successfully utilized for the sizing of paper prepared from all types of both cellulosic and combina-tions of cellulosic with non-cellulosic fibers. The cellulosic fibers which may be used include bleached and unbleached sulfate (kraft), bleached and unbleached sul-; fite, bleached and unbleached soda, neutral sulfite, semi-chemical chemig~ound-wood, ground wood, and any combina-tion of these fibers. These designations refer to wood pulp fibers which have been prepared by means of a variety of processes which are used in the pulp and paper indus-try. In addition, synthetic fibers of the viscose rayon or regenerated cellulose type can also be used.
All types of pigments and fillers may be addedto the paper which is to be sized with the novel sizing agents of this invention. Such materials include clay, ; talc, titanium dioxide, calcium carbonate, calcium sul- fate, and diatom~ceous earths. Other additives, including alum, as well as other sizing agents, can also be used with these sizing agents.
With respect to proportions, the sizing agents may be employed in amounts ranging from about 0.05 to about 3.0% of the dry weight of the pulp in the finished sheet or web. While amounts in excess of 3~ may be used, the benefits of increased sizing properties are usually not economically justified. Within the mentioned range the precise amount of size which is to be used will depend for the most ~art upon the type of pulp which is being utilized, the specific operating conditions, as well as the particular end use for which the paper is destined.
Thus, for example, paper which will require good water resistance or ink holdout will necessitate the use of a ~;~7~374 higher concentration of sizing agent than paper which does not.
05 The following examples are provided to illus-trate the invention in accordance with the principles of this invention but are not to be construed as limiting the invention in any way except as indicated by the appended claims.
EXAHPLES
Example 1 The alken~l succinic anhydride (ASA) employed in this example was a commercial type of liquid C15_20 ASA
prepared by the "Ene" reaction of maleic anhydride with C15_20 olefins. The olefins consisted of a 50/50 mixture of straight chain internal olefins and branched chain propylene oligomer, both of which covered the C15-C20 range, inclusive.
A 10% solution of Igepal C0-630, a commercial nonionic oil-in-water emulsifier, was made in the above ASA. This was a clear homogeneous solution at room tem-perature. One drop (0.026 g) of this mixture was shaken with 25 ml of water for 15 seconds in a stoppered graduate. A stable white emulsion was formed. This emul-sifier, which has an HLB of 13.0, is therefore an excellent emulsifier for ASA when freshly mixed.
The 10% emulsifier in ASA mixture was allowed to stand at room temperature~ After one week it would no longer form a stable emulsion. Similarly, when aging was accelerated by heating for 3 hours at 80C, the mixture would not form a stable emulsion.
Similar results were obtained with five other commercial emulsifiers, namely, Tergitol TMN-6, Tergitol 15-S-12, Trtion X-114, Triton X-100 and Igepal C0-620.
After heating for three hours at 80C, the 10% mixtures in ASA had lost their self-emulsifying power. The HLB of these emulsifiers ranyed from 11.7 to 14.5.
This example shows that commercial emulsifiers, which form excellent emulsions when freshly mixed with 4n ~Z~9874 ASA, do not from stable emulsions with ASA after aging the mixture.
05 Exampla 2 Igepal C0-630 was mixed in a 1/1 mole ratio with succinic anhydride and heated at 80C for four hours.
During that time the solid succinic anhydride all dissolved. An infrared analysis of the product indicated that a monoester had formed. An intense ester carbonyl absorption at 1735 cm 1 and carboxyl absorption at 3150 cm 1 were present. The hydroxyl absorption at 3480 cm 1 of the alkylphenol ethoxylate had disappeared.
The HLB of this capped emulsifier is estimated at 12.5.
Example 3 The capped emulsifier of Example 2 was mixed into the ASA of Example 1 at the 10~ level. A homogeneous solution at room temperature was obtained.
When this mixture was tested for emulsifying power by the procedure described in Example 1, it formed an excellent emulsion in water. However, in this case, the mixture was stable to storage. After accelerated aging, 3 hours at 80C, it still gave an excellent emul-sion-Therefore, the novel emulsifier of Example 2 exemplifies the present invention. It can be used to make ASA/emulsifier compositions which are stable to storage.
Example 4 Igepal C0-630 was capped with a series of different anhydride reagents as in Example 2 and the reac-tion produc a were tested as emulsifiers for ASA using the procedures described in Example 1. The results are listed in Table I.

- ~279~74 TAsLE I
Emulsifiers made from Igepal C0-630 _nd_Various Cyclic Anhydrides Cyclic Product ASA Emulsion Ratinq Anhydrlde HLB Fresh (a) Maleic 12.5 Good Good (b) PMDA3 12.3 Fair Fair (c) Diglycolic13.4 Good Good 1 Based on stability and turbidity measurements.
2 ASA/emulsifier mixture aged at 80C for 3 hours.

3 Pyromellitic dianhydride, half mole/mole was used.

These results show that various cyclic anhydrides can be used to make emulsifiers of the present invention. The fact that emulsifier performance was the same after aging shows that the Igepal C0-630 was success-fully capped in each case.
Example 5 Succinic anhydride was used to cap various poly-ethyleneoxy-containing surfactants as was done in Example 2 and the reaction products were tested as emulsifiers for ASA using the procedures described in Example 1. The results are listed in Table II. In Table II, the expres-sion "E0~ represents ethylene oxide units and the expres-sion "PEG" represents polyethylene glycol. The ASA/emulsifier mixtures were aged at 80C for 3 hours.

~Z79~374 TABLE II
Emulsifiers Made by Capping Various 05Surfactants with Succinic Anhydride Product ASA Emul Surfactant_ _LB Fresh Aged Alkyl Phenol Ethoxylates (a) C8~E7.5 11.8 Fair Fair (b) C8 EOg 5 12.8 Good Good (c) Cg-Eol2 5 13.9 Good Good (d) Cg-EO4 8.9 Ineffective Ineffective (e) C9-E8 11.8 Good Good ( f ) Cg~EOlo 5 13.0 Good Good (g) Cg-EOl2 13.5 Excellent Excellent (h) Cg~E100 18.8 Not soluble Not soluble at room at room temperature temperature Alcohol Ethoxylates (i) Tergitol TMN-611.2 Poor Poor (j) Tergitol 15-S-912.7 Good Good (k) Tergitol 15-S-1213.8 Good Good Fa ty Acid Ethoxylates (1) PEG 300 Laurate11.2 Poor Poor (m) PEG 400 Oleate11.2 Fair Fair Miscellaneous In) Ethoxylated sorbitan monostearate - EO20 14.6 Good Good (o) Stearyl Amine - EO15 13.3 Good Good (p) Pentaerythritol monolaurate 8.7 Very Poor Very Poor (q) Lauric Amide-EO510.2 Ineffective Ineffective The results shown in Table II demonstrate that a variety of polyethyleneoxy-containing surfactants may be capped to form emulsifiers of the present invention. In each case, the capped emulsifier is stable when aged in mixture with ASA, giving the same emulsion power before and after aging. The results also show that, to be an effective emulsifier, the HLB of the capped emulsifier should lie .

~ ~7~87~

between about 9 and 18. Below about 9, the capped emulsi-fier is ineffective. Above about 18, the emulsifier is not 05 soluble in ASA.

The emulsifier of Example 2 was mixed at the 10 level in several different types of ASA, namely:
(a) Straight chain C15_20 alkenyl ASA
~b) Isooctadecenyl ASA
(c) Isooctadecyl ASA
(d) A C20 ASA derived from a dimer of C10 straight chain alpha olefin (e) A branched chain ASA derived from tetrapropylene.
In each case, when tested by the procedures of Example 1, a stable emulsion was formed from both the freshly mixed and aged ASA/emulsifier mixtures.
Example 7 The capped emulsifier of Example 4(a) was 20 isomerized using the procedure of U.S. Patent No. 3,953,616, Example 3. This converted the capping group from a maleyl group to a fumaryl group. Several changes were observed in the infrared spectrum, including a slight shift in the car-bonyl to 1725 cm 1, the appearance of trans olefin at 975 25 cm~l, and the appearance of a band at 780 cm 1.
This product, when tested by the procedures of Example 1, produced a stable ASA emulsion, both before and after aging the ASA/emulsifier mixture.
Example 8 The emulsifier product of Example 2 was used in a paper sizing experiment. The sizing agent was the ASA
described in Example 6(a~. Eight percent of the emulsifier was dissolved in the ASA and the mixture was held for about one month. Normal TAPPI (Technical Association of the Pulp 35 and Paper Industry) laboratory handsheet procedures were followed using a 50/50 mixture of hardwood/softwood pulp, 0.4~ ASA, and 1~ cationic starch. A paddle stirrer was used to make the ASA/water emulsion. The handsheets were cured at 105C for one hour. The sizing results, measured on a 40 Hercules Size Tester, were equal to that obtained from the ~;2798~4 same ASA to which 7~ Igepal C0-630 had been added just before emulsif ication.

.~ .

lC

~ ' 15

Claims

1. An emulsifier of the formula:
R-W?Y-(COOH)m]n wherein R is a hydrophobic alkyl, alkylaryl, arylalkyl or acyl group containing from 8 to 30 carbon atoms;
W is a water-soluble polyethyleneoxy-containing group having from 3 to 80 ethylene oxide units which is indepen-dently connected to R and Y through oxygen, sulfur, or nitrogen linkages;
?Y-(COOH)m]n is a capping group for the oxygen, sulfur or nitrogen linkages on W not connected to R, wherein Y
contains from 1 to 9 carbon atoms, provided that no more than 7 carbon atoms are methylene carbons;
m is 1 or 2;
n is 1/3, 1/2, 1, 2, or 3;
and the hydrophile-lipophile balance is between about 9 and 18 on the HLB scale.

2. The emulsifier according to Claim 1, wherein W has from 5 to 40 ethylene oxide units.

3. The emulsifier according to Claim 1, wherein W is connected to R and Y through oxygen linkages.

4, The emulsifier according to Claim 1, wherein Y
contains from 1 to 4 carbon atoms.

5. The emulsifier according to Claim 1, wherein R-W-is derived from hydroxyl-containing compounds selected from the group consisting of:

and , wherein x is an integer from 8 to 24 and z is an integer from 5 to 20.

6. The emulsifier according to Claim 1, wherein [-Y-(COOH)m]n is selected from the group consisting of:

-CH2COOH,

7. The emulsifier according to Claim 6, wherein [-Y-(COOH)m]n is selected from the group consisting of:

8. The emulsifier according to Claim 1, wherein the hydrophile-lipophile balance is about 11 to 16 on the HLB
scale.

9. A stable hydrocarbyl-substituted succinic anhy-dride/emulsifier composition comprising:
(A) 70 to 99.5% of a normally liquid hydrocarbyl-substituted succinic anhydride containing from 6 to 50 carbon atoms in the substituent; and (B) 0.5 to 30% of an emulsifier of the formula:
R-W?Y-(COOH)m]n wherein R is a hydrophobic alkyl, alkylaryl, arylalkyl or acyl group containing from 8 to 30 carbon atoms;
W is a water-soluble polyethyleneoxy-containing group having from 3 to 80 ethylene oxide units which is indepen-dently connected to R and Y through oxygen, sulfur or nitro-gen linkages;
?Y-(COOH)m]n is a capping group for the oxygen, sulfur or nitrogen linkages on W not connected to R, wherein Y
contains from 1 to 9 carbon atoms, provided that no more than 7 carbon atoms are methylene carbons;
m is 1 or 2;
n is 1/3, 1/2, 1, 2, or 3;
and the hydrophile-lipophile balance is between about 9 and 18 on the HLB scale.

10. The composition according to Claim 9, wherein the hydrocarbyl substituent of component (A) is selected from the group consisting of alkyl, alkenyl and aralkyl.

11. The composition according to Claim 10, wherein the hydrocarbyl substituent of component (A) is alkenyl.

12. The composition according to Claim 9, wherein the hydrocarbyl substituent of component (A) contains from 10 to 30 carbon atoms.

13. The composition according to Claim 12, wherein the hydrocarbyl substituent of component (A) contains from 12 to 25 carbon atoms.

14. The composition according to Claim 9, wherein W
has from 5 to 40 ethylene oxide units.

15. The composition according to Claim 9, wherein W is connected to R and Y through oxygen linkages.

16. The composition according to Claim 9, wherein Y
contains from l to 4 carbon atoms.

17. The composition according to Claim 9, wherein R-W-is derived from hydroxyl-containing compounds selected from the group consisting of:

wherein x is an integer from 8 to 24 and z is an integer from 5 to 20.

18. The composition according to Claim 9, wherein [-Y-(COOH)m]n is selected from the group consisting of:

-CH2COOH,

19. The composition according to Claim 18, wherein [-Y-(COOH)m]n is selected from the group consisting of:

20. The composition according to Claim 9, wherein the emulsifier of component (B) has a hydrophile-lipophile balance of about 11 to 16 on the HLB scale.

21. The composition according to Claim 9, wherein the composition is in the form of an aqueous emulsion.

22. A method of imparting water repellency to surfaces containing groups reactive to anhydrides which comprises impregnating said surfaces with an aqueous emulsion of the composition of Claim 9.

23. The method of Claim 22, wherein said surfaces are cellulosic materials.

24. A method of sizing paper which comprises the step of intimately dispersing within the wet pulp, prior to the ultimate conversion of said pulp into a dry web, an aqueous emulsion of the composition of Claim 9.