Plasticized composition comprising polyvinylbutyral resin having controlled stereochemistry
View Patent ↗Provided herein is a polyvinylbutyral (PVB) resin having a meso/racemic stereoisomer ratio of from about 2.5 to about 5.0. Further provided herein is a plasticized PVB composition comprising the PVB resin. Manipulation of the PVB stereoisomer ratio can provide an additional method of controlling the physical properties of the PVB composition, in addition to or in lieu of changing additives or otherwise manipulating the PVB composition.
1. A plasticized polyvinylbutyral composition comprising (a) a polyvinylbutyral resin having a hydroxyl number of from about 15 to about 34 and comprising cyclic acetals in a mixture of meso and racemic stereoisomers, wherein the ratio of meso to racemic stereoisomers (M/R) is in the range of from about 3.1 to about 3.5; (b) a surfactant; and (c) a plasticizer in an amount of from about 30 to about 50 parts per hundred (pph) based on the dry weight of the polyvinylbutyral resin;
wherein a sheet consisting of the plasticized polyvinylbutyral composition has a tensile creep is from 1.17 to 3.0.
2. The plasticized polyvinylbutyral composition of claim 1 wherein the surfactant is selected from the group consisting of sodium dioctylsulfosuccinate, sodium methyl cocoyl taurate, sodium lauryl sulfate, and a combination of two or more of sodium dioctylsulfosuccinate, sodium methyl cocoyl taurate and sodium lauryl sulfate.
3. The plasticized polyvinylbutyral composition of claim 2 wherein the polyvinylbutyral resin has a hydroxyl number of from about 17 to about 19.
4. The plasticized polyvinylbutyral composition of claim 3 wherein the tensile creep is less than or equal to 2.5.
5. The plasticized polyvinylbutyral composition of claim 4 wherein the tensile creep is less than or equal to 1.5.
6. The plasticized polyvinylbutyral composition of claim 2 wherein the surfactant comprises sodium lauryl sulfate.
7. The plasticized polyvinylbutyral composition of claim 2 wherein the surfactant comprises sodium dioctylsulfosuccinate.
8. The plasticized polyvinylbutyral composition of claim 2 wherein the surfactant consists essentially of sodium methyl cocoyl taurate.
9. The plasticized polyvinylbutyral composition of claim 2 wherein the amount of the surfactant is at least 0.1 wt %, based on the dry weight of a polyvinyl alcohol from which the polyvinylbutyral resin is derived.
10. The plasticized polyvinylbutyral composition of claim 9 wherein the amount of the surfactant is about 0.10 to about 0.70 wt %.
11. The plasticized polyvinylbutyral composition of claim 9 wherein the amount of the surfactant is about 0.20 to about 0.50 wt %.
12. The plasticized polyvinylbutyral composition of claim 2 wherein the polyvinylbutyral resin is derived from a polyvinyl alcohol having a degree of polymerization of about 618 or about 1005.
13. The plasticized polyvinylbutyral composition of claim 1 further comprising one or more additives selected from the group consisting of antioxidants, light stabilizers, adhesion control agents, and surface tension controlling agents.
14. The plasticized polyvinylbutyral composition of claim 1 comprising about 32 to about 45 pph of the plasticizer.
15. The plasticized polyvinylbutyral composition of claim 1 wherein the plasticizer is selected from the group consisting of diesters obtained from the chemical reaction of aliphatic diols with carboxylic acids, esters obtained from the chemical reaction polyvalent carboxylic acids and aliphatic alcohols, and combinations of two or more of these esters and diesters.
16. The plasticized polyvinylbutyral composition of claim 15 wherein the plasticizer comprises one or more diesters of polyether diols or diesters of polyether polyols.
17. The plasticized polyvinylbutyral composition of claim 15 wherein the plasticizer comprises one or more of diesters obtained by the reaction of triethylene glycol or tetraethylene glycol with aliphatic carboxylic acids having from 6 to 10 carbon atoms; and diesters obtained from the reaction of sebacic acid with aliphatic alcohols having from 1 to 18 carbon atoms.
18. The plasticized polyvinylbutyral composition of claim 17 wherein the plasticizer comprises one or more of triethyleneglycol di-(2-ethyl hexanoate) (3GO), dibutyl sebacate (DBS) and tetraethylene glycol di(2-heptanoate) (4G7).