Claims
- 1. As a composition of matter, a citric ester having the formula: ##STR3## wherein R.sub.1 and R.sub.2 are selected from: ##STR4## thereof; wherein R.sub.3 is ##STR5## wherein R.sub.4 and R.sub.5 are H, or an alkyl, cycloalkyl, or alkyl ester group containing 1 to about 32 carbon atoms, wherein said alkyl ester group is derived from epoxidized esters of unsaturated acids or glycidyl esters of monocarboxylic acids, wherein the total number of carbon atoms in R.sub.4 and R.sub.5 is 0 to about 32; wherein R.sub.6 is an alkyl group containing 1 to about 18 carbon atoms, or a cyclo alkyl group containing 5 to about 10 carbon atoms; wherein R.sub.7 is an alkyl, cycloalkyl, or alkyl ester group containing 4 to about 32 carbon atoms, wherein said alkyl ester group is derived from epoxidized esters of unsaturated acids or glycidyl esters of monocarboxylic acids, and wherein x has a value of 3 to 6;
- wherein R.sub.1, R.sub.2 and R.sub.3 are so selected that the total number of 0H groups in R.sub.1, R.sub.2 and R.sub.3 is about 1.5 to 3 and the total number of carbon atoms in R.sub.1, R.sub.2 and R.sub.3 is 8 to about 40; and wherein the acid value of the ester is less than about 35.
- 2. The composition of claim 1 wherein R.sub.1, R.sub.2 and R.sub.3 are derived from glycols which contain from 2 to 12 carbon atoms and at least one primary hydroxyl group, a vicinal epoxide compound which contains only one epoxide group per molecule, or a primary or secondary alcohol which contains from 1 to 18 carbon atoms.
- 3. The composition of claim 2 wherein the vicinal epoxide compound is an alpha olefin which contains from 2 to about 18 carbon atoms.
- 4. The composition of claim 2 wherein the vicinal epoxide compound is an epoxidized ester of an unsaturated acid wherein the acid contains about 18 to about 22 carbon atoms and the ester group is an alkyl group containing about 1 to about 8 carbon atoms.
- 5. The composition of claim 2 wherein the vicinal epcxide compound is a glycidyl ester of Versatic Acid.
- 6. The composition of claim 2 wherein the vicinal epoxide compound is a monoepoxide of a copolymer of isobutylene and butene having an average molecular weight of about 300 to about 400.
- 7. The composition of claim 1 wherein the R substituents of the citric ester are the following organic radicals in the following equivalent amounts:
- butyl--about 0.5 to about 1.5
- cyclohexyl--0 to about 1
- hydroxypropyl--about 0 to about 1.5
- hydroxyethyl--0 to about 0.5
- hydroxy C.sub.8 -C.sub.14 alkyl-about 0.1 to about 1 wherein the total number of equivalents is 3.
- 8. The composition of claim 1 wherein the ester contains about 1.5 equivalents of butyl, about 1 equivalent of hydroxypropyl, and about 0.5 equivalent of hydroxyalkyl containing 10 carbon atoms.
- 9. The composition of claim 1 wherein the ester contains about 0.5 equivalent of butyl, about 1 equivalent of cyclohexyl, about 0.75 equivalent of hydroxypropyl, and about 0.75 equivalent of hydroxyalkyl containing 8 carbon atoms.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. application Ser. No. 248,732, filed Sept. 26, 1988, now abandoned.
The field of art to which this invention pertains is citric esters.
Citric esters are well known compositions which have been used as plasticizers, lubricants and anti-settling additives for paints.
U.S. Pat. No. 2,122,716 describes long chain esters of citric acid, e.g., tridodecyl citrate, which have been used as plasticizers for resinous compositions.
U.S. Pat. Nos. 3,239,555 and 3,241,992 disclose bis-citric acid esters made by esterifying the acid groups with C.sub.1 to C.sub.18 alcohols and coupling the esters with dibasic acids. Such esters are useful as plasticizers for plastics.
In U.S. Pat. No. 3,251,792, the acid groups of citric acid are esterified with alkyl, aryl, cycloalkyl and haloaryl alcohols and the hydroxyl group is esterified with a carbonyl compound. Such compounds are used as stabilizers for polypropylene.
Lubricants for tinplate are disclosed in U.S. Pat. No. 4,287,741. Such lubricants are citric esters wherein at least one acid group is esterified with a one to 10 carbon alcohol and the hydroxyl group can be esterified with a 1 to 10 carbon acid.
Polyesters made by reacting glycols and allyl alcohol with citric acid are described in U.S Pat. No. 2,936,297.
In German Patent No. 1,228,736, distearyl citrate is disclosed as being useful to prevent settling of pigments in paints.
Internal processing lubricants for thermoplastics made from copolyesters of aliphatic diols, citric acid and long-chain monohydric alcohols are disclosed in British Patent No.
This invention is directed to citric acid esters. In one aspect, this invention pertains to citric acid esters which contain at least one primary or secondary hydroxyl group. In another aspect, this invention relates to citric acid esters which are reactive diluents. In still another aspect, this invention pertains to citric esters which are pigment dispersants.
The citric ester composition of this invention has the formula: ##STR1## wherein R.sub.1 and R.sub.2 are selected from ##STR2## wherein R.sub.4 and R.sub.5 are H, or an alkyl, cycloalkyl, or an alkyl ester group containing 1 to about 32 carbon atoms alkyl ester group is derived from epoxidized esters of unsaturated acids or glycidyl esters of monocarboxylic acids, wherein the total number of carbon atoms in R.sub.4 and R.sub.5 are 0 to about 32;wherein R.sub.6 is an alkyl group containing 1 to about 18 carbon atoms, or a cycloalkyl group containing 5 to about 10 carbon atoms; wherein R7 is an alkyl, cycloalkyl or alkyl ester group containing 4 to about 32 carbon atoms wherein said alkyl ester group is derived from epoxidized esters of unsaturated acids or glycidyl esters of monocarboxylic acids; and wherein x has a value of 3 to 6. Each of these R groups is so selected that the total number of OH groups in R.sub.1, R.sub.2 and R.sub.3 is 1.5 to 3, and the total number of carbon atoms varies from 8 to 40. The acid value of the esters is less than about 35.
The citric ester compositions of this invention are useful as reactive diluents for high solids thermosetting coating composition and as pigment dispersants for use in thermosetting coatings.
Foreign Referenced Citations (2)
| Number |
Date |
Country |
| 894612 |
Jan 1983 |
BEX |
| 026932 |
Dec 1967 |
JPX |
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
248732 |
Sep 1988 |
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Patent Grant
5089658
