Aqueous dispersions of nucleating agents
View Patent ↗A storage stable aqueous dispersion useful in preparing sizing compositions for glass fibers contains a normally solid nucleating agent, a nonionic surfactant, and a base. The nucleating agent is a mixture of an aliphatic monocarboxylic acid and an aliphatic dicarboxylic acid. Also disclosed are the process of making the dispersion, and the use of the sized glass fibers in glass fiber reinforced polyolefin composites having improved mechanical properties such as tensile strength, flexural strength, and notched and unnotched IZOD.
1. A storage stable aqueous dispersion comprising from about 15 to about 30 percent by weight of a normally solid nucleating agent, an effective amount of surfactant, up to about 10 percent by weight of base, and water.
2. The aqueous dispersion of claim 1 wherein the normally solid nucleating agent is a mixture of at least one aliphatic monocarboxylic acid having 8 to about 24 carbon atoms and at least one aliphatic dicarboxylic acid having 4 to about 21 carbon atoms in a weight ratio between about 1:4 and about 4:1.
3. The aqueous dispersion of claim 1 wherein the normally solid nucleating agent is a mixture of stearic acid and adipic acid.
4. The aqueous dispersion of claim 1 wherein the nucleating agent is a mixture of stearic acid and sebacic acid.
5. The aqueous dispersion of claim 1 wherein the nucleating agent is a mixture of behenic acid and dodecanedioic acid.
6. The aqueous dispersion of claim 1 wherein the surfactant represents from about 0.5 to about 15 percent by weight of the dispersion.
7. The aqueous dispersion of claim 1 wherein the surfactant is selected from the group consisting of ethoxylated alkyl phenols, ethoxylated alkyl alcohols, and ethoxylated fatty acids.
8. The aqueous dispersion of claim 7 wherein the ethoxylated alkyl phenols comprise ethoxylated nonylphenol having 2 to 12 ethylene oxide units.
9. The aqueous dispersion of claim 7 wherein the ethoxylated alkyl alcohols comprise ethoxylated lauryl alcohol having about 2 to about 12 ethylene oxide units.
10. The aqueous dispersion of claim 7 wherein the ethoxylated alkyl alcohol comprise ethoxylated decyl alcohol having about 2 to about 12 ethylene oxide units.
11. The aqueous dispersion of claim 7 wherein the ethoxylated alkyl alcohols comprise ethoxylated tridecyl alcohol having about 2 to about 12 ethylene oxide units.
12. The aqueous dispersion of claim 1 having pH in the range of about 5.0 to about 8.0.
13. A sizing composition comprising the aqueous dispersion of claim 1 .
14. A composition comprising glass fibers coated with the sizing composition of claim 13 .
15. A composite comprising polyolefin and the coated glass fibers of claim 14 .