Compositions and methods for making polyesters and articles therefrom
View Patent ↗Polyester materials, methods for making polyesters materials, and uses of the polyester materials in binder materials and articles of manufacture are disclosed. In one embodiment, a process is provided for preparing a polyester solution, including mixing monomers of at least one organic acid containing at least three carboxylic groups and at least one multi-hydroxyl alcohol containing at least three hydroxyl groups to form a reaction mixture, heating the reaction mixture to a first temperature, polymerizing the monomers at the first temperature until reaching an acid value from about 200 to about 400 mg KOH/g, adjusting the temperature to a second temperature less than the first temperature, and forming the polyester solution. The polyester materials may be mixed with cross-linking materials to form binder materials. The binder material may then be used to form articles of manufacture.
1. A process for forming a binder material, comprising:
forming a polyester solution, comprising:
mixing monomers of at least one organic acid containing at least three carboxylic groups and at least one multi-hydroxyl alcohol containing at least three hydroxyl groups;
heating the reaction mixture to a first temperature;
polymerizing the monomers at the first temperature until reaching an acid value from about 200 to about 400 mg KOH/g; and
adjusting the temperature to a second temperature less than the first temperature;
adding a vinyl alcohol containing polymer to the reaction mixture; and
adding a cross-linking agent comprising an acrylic polymer, wherein the binder material is free of formaldehyde.
2. The process of claim 1 , wherein the cross-linking agent further comprises an aldehyde compound.
3. The process of claim 2 , wherein the aldehyde compound is a formaldehyde-free aldehyde component selected from the group consisting of glyoxal, glutaraldehyde compound, and combinations thereof.
4. The process of claim 1 , wherein the acrylic polymer is selected from the group consisting of polyacrylic acid, polyacrylic ether polymer, polyacrylic ester polymer, polyacrylic amide polymer, and combinations thereof.
5. The process of claim 1 , wherein vinyl alcohol containing polymer comprises polyvinyl alcohol, a derivative thereof or a co-polymer thereof.
6. The process of claim 3 , wherein polyester material is water-soluble.
7. The process of claim 1 , wherein the at least one organic acid having three carboxylic groups comprises citric acid and the at least one multi-hydroxyl alcohol having three hydroxyl groups is selected from the group consisting of glycerol, trimethylolpropane, trimethyolethane, and combinations thereof.
8. The process of claim 1 , wherein the ratio of at least one organic acid to at least one multi-hydroxyl alcohol is from 1:3 to 3:1.
9. The process of claim 1 , further comprising adding the binder material to a substrate and then curing the substrate.
10. The process of claim 9 , wherein the curing the substrate comprises a curing process from about 1 to about 6 minutes at a temperature from about 350° F. to about 450° F.
11. The process of claim 10 , wherein the wet web strength of the binder and substrate is from about 180 g to about 400 g, before the curing the substrate.
12. The process of claim 1 , wherein the acid value is from about 200 to about 300 mg KOH/g.
13. The process of claim 1 , wherein the acid value is from about 200 to about 250 mg KOH/g.