# US 2024/0199795 A1 · Synthesis of environmentally degradable alkyl polyesters

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- Number: US 2024/0199795 A1
- Document ID: US20240199795A1
- Status: Published application
- Kind: A1
- Application number: 18/332,724
- Filed: 2023-06-10
- Published: 2024-06-20
- Earliest claimed: 2022-06-16
- Assignees: Akina, Inc.
- Applicants: Akina Inc.
- Inventors: Kinam Park; John Solomon Garner
- Web page: https://patentgrep.com/patent/US20240199795A1

## CPC

- C08G 63/137: Acids or hydroxy compounds containing cycloaliphatic rings
- C08G 63/60: derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
- C09D 167/00: Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09D177/12; based on polyester-imides C09D179/08); Coating compositions based on derivatives of such polymers
- C08G 2230/00: Compositions for preparing biodegradable polymers
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)

## Abstract

A solid polyester wherein the polyester is environmentally degradable in less than about 5 to about 7 months. The polyester is the direct dehydration polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, and one or more multi-carboxylic acid compounds without added catalysts or cyclic precursors; or the polyester is the direct dehydration polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, one or more multi-carboxylic acid compounds, and a cyclic ester without requiring added catalysts or cyclic precursors.

## Claims

### Claim 1

A composition comprising a solid polyester wherein the polyester is environmentally degradable in less than about 5 to about 7 months and;
wherein the polyester is the direct dehydration polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, and one or more multi-carboxylic acid compounds without added catalysts or cyclic precursors; or
the polyester is the direct dehydration polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, one or more multi-carboxylic acid compounds, and a cyclic ester without requiring added catalysts or cyclic precursors.

### Claim 2 (depends on 1)

The composition of claim 1 wherein the solid polyester is partially crosslinked to form a thermoplastic.

### Claim 3 (depends on 1)

The composition of claim 1 wherein the solid polyester is crosslinked to form a thermoset.

### Claim 4 (depends on 1)

The composition of claim 1 wherein the weight percent of the one or more multi-hydroxylic alcohols is about 5% to about 85%, the weight percent of the one or more multi-carboxylic acid compounds is about 5% to about 85%, and the weight percent of the one or more hydroxy acids is about 10% to about 90%, with the proviso that the total weight percent of the combined multi-hydroxylic alcohols, the multi-carboxylic acids compounds, and the hydroxy acids does not exceed 100%.

### Claim 5 (depends on 1)

The composition of claim 1 wherein catalysis for the esterification reaction is provided by the one or more hydroxy acids, the one or more multi-carboxylic acid compounds, or both the one or more hydroxy acids and the one or more multi-carboxylic acid compounds without additional metal or organic catalysts at a temperature from about 50° C. to about 300° C.

### Claim 6 (depends on 1)

The composition of claim 1 wherein the temperature is from about 100° C. to about 170° C.

### Claim 7 (depends on 1)

The composition of claim 1 wherein the polyester has a Shore hardness score of at least 80.

### Claim 8 (depends on 1)

The composition of claim 1 wherein the polyester degrades upon exposure to naturally occurring water at 30° C., losing at least about 80% of its mass in about two months.

### Claim 9 (depends on 1)

The composition of claim 1 wherein the one or more multi-hydroxylic alcohols is selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, glycerol, adonitol, cellulose, cellulose-ether derivatives, starch, poly(vinyl alcohol), dextran, alginic acid, hyaluronic acid, and chitosan.

### Claim 10 (depends on 1)

The composition of claim 1 wherein the one or more multi-carboxylic acid compounds is selected from the group consisting of citric acid, poly(acrylic acid), isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid, and trimesic acid.

### Claim 11 (depends on 1)

The composition of claim 1 wherein the one or more hydroxy acids is selected from the group consisting of lactic acid, glycolic acid, 3-hydroxypropionic acid, 3-hydroxybutanoic acid, and salicylic acid.

### Claim 12 (depends on 1)

The composition of claim 1 wherein the cyclic ester is selected from the group consisting of caprolactone, propiolactone, butyrolactone, valerolactone, acetolactone, lactide, and glycolide.

### Claim 13 (depends on 1)

The composition of claim 1 further comprising one or more additives selected from the group consisting of polyols, chain-extenders, surfactants, cyclic esters, alcohols, metal-catalysts, poly(ethylene glycols), and hydroxy acids to modify the mechanical properties of the polyester.

### Claim 14 (depends on 1)

The composition of claim 1 further comprising one or more filler substances added before polymerization to alter one or more properties of polyester polymer selected from the group consisting of opacity, color, mechanical strength, stiffness, and porosity.

### Claim 15 (depends on 14)

The composition of claim 14 wherein the one or more filler is selected from the group consisting of silica, sand, salt, polymer, fiberglass, cellulose, paper fiber, and aluminum.

### Claim 16 (depends on 1)

The composition of claim 1 wherein the solid polyester is mechanically rigid.

### Claim 17 (depends on 1)

The composition of claim 1 wherein the solid polyester is mechanically rubbery.

### Claim 18 (depends on 1)

The composition of claim 1 wherein the solid polyester comprises pentaerythritol, citric acid, and lactic acid at a weight ratio from about 1:1:1 to about 1:1:10.

### Claim 19 (depends on 18)

The composition of claim 18 wherein the weight ratio is from about 1:1:3 to about 1:1:7.

### Claim 20 (depends on 1)

The composition of claim 1 wherein the solid polyester comprises glycerol, citric acid, and lactic acid at a weight ratio of about 1:1:1 to about 1:1:10.

### Claim 21 (depends on 20)

The composition of claim 20 wherein the weight ratio is about 1:1:3 to about 1:1:7

### Claim 22 (depends on 1)

The composition of claim 1 wherein the solid thermoplastic polyester is ground into fine particles and added into molds to cure.

### Claim 23 (depends on 1)

The composition of claim 1 wherein the solid thermoplastic polyester is compressed in molds to cure.

### Claim 24 (depends on 1)

The composition of claim 1 wherein the solid polyester is used to make replacements of non-degradable single-use plastics, e.g., cutlery, plates, cups, straws, toothbrushes, combs, toys, packaging materials, and containers.

### Claim 25 (depends on 1)

The composition of claim 1 wherein the solid polyester is sterilized by radiation sterilization.

### Claim 26 (depends on 1)

The composition of claim 1 wherein the solid polyester is used to coat solid substrates to protect them from an environmentally caused damage selected from the group consisting of mechanical damage, chemical damage, and moisture absorption.

### Claim 27 (depends on 1)

The composition of claim 1 wherein the solid polyester which becomes rubbery after storing at room temperature for months is incubated at about 100° C. to 170° C. for from about 6 to about 100 hours to recover and extend the original mechanical properties.

### Claim 28 (depends on 1)

A process for preparing the polyester of claim 1 comprising the steps of:
a) preparing a mixture of one or more multi-hydroxylic alcohols, one or more multi-carboxylic acid compounds, one or more hydroxy acids, and optionally a cyclic ester;
b) optionally, dissolving water-soluble compounds in step a) in water before adding other components;
c) optionally, preparing a prepolymer by heating the mixture at about 30° C. to about 100° C. for from about 1 to about 168 hours in a covered container with mixing to yield a partially esterified prepolymer; and
d) heating the mixture or the prepolymer at a temperature of about 90° C. to about 300° C. for from about 1 to about 192 hours with open access to air or vacuum to yield the polyester.

### Claim 29 (depends on 28)

The process of claim 28 wherein the mixture includes about 5% to about 85% (weight percent) of the one or more multi-hydroxylic alcohols, about 5% to about 85% (weight percent) of the one or more multi-carboxylic acid compounds, and from about 10% to about 90% (weight percent) of the one or more hydroxy acids with the proviso that the combined weight percentage of the one or more multi-hydroxylic alcohols, the one or more multi-carboxylic acid compound, and the one or more hydroxy acids does not exceed 100%.

### Claim 30 (depends on 28)

The process of claim 28 wherein the one or more multi-hydroxylic alcohols is selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, glycerol, adonitol, cellulose, cellulose-ether derivatives, starch, poly(vinyl alcohol), dextran, alginic acid, hyaluronic acid, and chitosan.

### Claim 31 (depends on 28)

The process of claim 28 wherein the one or more multi-carboxylic acid compounds is selected from a group consisting of citric acid, poly(acrylic acid), isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid, and trimesic acid.

### Claim 32 (depends on 28)

The process of claim 28 wherein the one or more hydroxy acids is selected from the group consisting of lactic acid, glycolic acid, 3-hydroxypropionic acid, 3-hydroxybutanoic acid, and salicylic acid.

### Claim 33 (depends on 28)

The process of claim 28 wherein the cyclic ester is selected from the group consisting of caprolactone, propiolactone, butyrolactone, valerolactone, acetolactone, lactide, and glycolide.

### Claim 34 (depends on 28)

The process of claim 28 wherein the mixture is comprised of pentaerythritol, citric acid, and lactic acid at the weight ratio of about 1:1:1 to about 1:1:10.

### Claim 35 (depends on 34)

The process of claim 34 wherein the weight ratio is about 1:1:3 to about 1:1:7.

### Claim 36 (depends on 28)

The process of claim 28 wherein the mixture is comprised of glycerol, citric acid, and lactic acid at the weight ratio of about 1:1:1 to about 1:1:10.

### Claim 37 (depends on 36)

The process of claim 36 wherein the weight ratio is about 1:1:3 to about 1:1:7.

### Claim 38 (depends on 28)

The process of claim 28 wherein the prepolymer is generated by incubating at temperatures from about 30° C. to about 90° C. for about 1 to about 250 hours.

### Claim 39 (depends on 28)

The process of claim 28 wherein the mixture or the prepolymer is heated at from about 110° C. to about 200° C. for from about 1 to about 250 hours to yield the polyester.

### Claim 40 (depends on 28)

The process of claim 28 wherein the mixture or the prepolymer is heated at from about 130° C. to about 180° C. for from about 6 to about 220 hours to yield the polyester.

### Claim 41 (depends on 28)

The process of claim 28 wherein the mixture or the prepolymer is heated at from about 150° C. to about 170° C. for from about 9 to about 200 hours to yield the polyester.

### Claim 42 (depends on 28)

The process of claim 28 where the mixture or the prepolymer is heated in a mold.

### Claim 43 (depends on 28)

The process of claim 28 wherein the solid polyester is mechanically rigid.

### Claim 44 (depends on 28)

The process of claim 28 wherein the solid polyester is mechanically rubbery.

### Claim 45 (depends on 28)

The process of claim 28 wherein wires or other electrical components are embedded within the prepolymer before step c) to obtain a polyester containing the embedded electrical components.

### Claim 46 (depends on 28)

The process of claim 28 wherein the solid thermoplastic polyester is ground into fine particles and added into molds to cure.

### Claim 47 (depends on 28)

The process of claim 28 wherein the solid thermoplastic polyester is compressed in molds to cure.

### Claim 48 (depends on 28)

The process of claim 28 wherein the solid polyester is used to make replacements of non-degradable single-use plastics, e.g., cutlery, plates, cups, straws, toothbrushes, combs, toys, packaging materials, and containers.

### Claim 49 (depends on 28)

The process of claim 28 wherein the solid polyester is terminally sterilized by radiation sterilization.

### Claim 50 (depends on 28)

The process of claim 28 wherein the solid polyester is used to coat solid substrates to protect them from an environmentally caused damage selected from the group consisting of mechanical damage, chemical damage, and moisture absorption.