# US 5,350,783 A · Compostable thermoplastic products

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- Number: US 5,350,783 A
- Document ID: US5350783A
- Status: Granted
- Kind: A
- Application number: 08/082,361
- Filed: 1993-06-28
- Granted: 1994-09-27
- Earliest claimed: 1991-11-21
- Assignees: Biolan Corporation
- Inventors: Murray H. Reich
- Web page: https://patentgrep.com/patent/US5350783A

## CPC

- C08J 11/16: by treatment with inorganic material (C08J11/14 takes precedence)
- A61L 15/62: {Compostable,} hydrosoluble or hydrodegradable materials
- C08K 3/04: Carbon
- C08K 3/22: of metals
- C08L 23/02: not modified by chemical after-treatment
- C08L 23/06: Polyethylene
- C08L 23/0869: with unsaturated acids, e.g. [meth]acrylic acid; with unsaturated esters, e.g. [meth]acrylic acid esters
- C08L 23/10: Homopolymers or copolymers of propene
- C08L 23/142: {at least partially crystalline copolymers of propene with other olefins}
- C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers
- C08L 23/18: Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
- C08L 51/06: grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
- C08L 77/00: Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain (of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08); Compositions of derivatives of such polymers
- C08L 91/00: Compositions of oils, fats or waxes; Compositions of derivatives thereof
- C08L 101/00: Compositions of unspecified macromolecular compounds
- C08J 2323/00: Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08K 5/0033: {Additives activating the degradation of the macromolecular compound}
- C08K 5/098: Metal salts of carboxylic acids
- C08L 2201/06: Biodegradable
- C08L 2205/035: containing four or more polymers in a blend
- C08L 2207/06: Properties of polyethylene
- Y02W 30/62: Plastics recycling; Rubber recycling
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT

## Abstract

Thermoplastic polymer product of a thermoplastic material including a thermoplastic polymer and polymeric composting promoting agent selected from the group consisting of nonmetallic metal complexing agents, nonoxidizing-metal metal complexing agents, and mixtures thereof, in a composting effective amount to convert in the presence of oxidizing metal compounds to an active oxidant to thermally degrade the thermoplastic polymer of the thermoplastic material under composting conditions to a low molecular weight material with enhanced biodegradability, the nonmetallic metal complexing agents and the nonoxidizing-metal metal complexing agents being neither photoactivators nor prooxidants.

## Claims

### Claim 1

Process for composing thermoplastic material including the steps of providing thermoplastic material including a thermoplastic polymer and polymeric composting promoting agent selected from the group consisting of metal complexing agents and metal complexes, and mixtures thereof, in a composting effective amount to convert in the presence of oxidizing metal selected from a group consisting of copper, iron, manganese and cobalt, to an active oxidant, contacting said thermoplastic material with a media containing oxidizing metal selected from a group consisting of garden waste, food waste, paper, wood chips, sewage sludge, mixed solid organic waste, sewage sludge and mixed solid organic waste, lime, manure, and liquid media solutions of oxidizing metals, to cause said oxidizing metal to convert said polymeric composting converting agent to said active oxidant in an amount sufficient to cause said active oxidant to thermally degrade said thermoplastic polymer to a low molecular weight material having enhanced biodegradability under composting conditions and concomitantly subjecting said thermoplastic material to composting conditions to at least partially biodegrade said low molecular material.

### Claim 2 (depends on 1)

Process according to claim 1 wherein said thermoplastic material is contacted with said media containing said oxidizing metal under composting conditions.

### Claim 3 (depends on 1)

Process according to claim 1 wherein said thermoplastic material is contacted with said media containing said oxidizing metal under non-composting conditions.

### Claim 4 (depends on 1)

Process according to claim 1 wherein either said metal complexing agent or said metal complexes or both are prooxidants.

### Claim 5 (depends on 1)

Process according to claim 1 wherein one of said metal complexing agents is a stabilizer and wherein said step of contacting said thermoplastic material with said media contacting said oxidizing metal is the further step of causing said oxidizing metal to substantially destabilize said stabilizer.

### Claim 6 (depends on 1)

Process according to claim 1 wherein said media is sewage sludge and mixed solid organic waste and wherein said contacting step is the step of contacting said thermoplastic material with said sewage sludge and said mixed solid organic waste for about 3 days to about 8 weeks at temperatures of about 15.degree. C. to about 80.degree. C., and where in said subjecting step is the step of subjecting said thermoplastic material to composting conditions selected from a group consisting of aerated windrows compost piles, and conveyor systems for about 1 to about 90 days and curing the mixture of sewage sludge and mixed solid organic waste and thermoplastic material from about 1 day to about 10 months in an open compost pile.

### Claim 7 (depends on 1)

Process according to claim 1 wherein said media in a sewage sludge and mixed solid organic waste and wherein said contacting step is the step of contacting said thermoplastic material with said sewage sludge and said mixed solid organic waste for about 5 days to 4 weeks at temperatures of 15.degree. C. to 80.degree. C., and wherein said subjecting step is the step of subjecting said thermoplastic material to composting conditions selected from a group consisting of aerated windrows, compost piles, and conveyor systems for about 5 to about 90 days and curing the mixture of sewage sludge and mixed solid organic waste and thermoplastic material from about 7 days to about 6 months in an open compost pile.

### Claim 8 (depends on 1)

Process according to claim 1 wherein said media is sewage sludge and mixed solid organic waste and wherein said contacting step is the step of contacting said thermoplastic material with said sewage sludge and said mixed solid organic waste for about 7 days to 3 weeks at temperatures of about 15.degree. C. to about 80.degree. C., and wherein said subjecting step is the step of subjecting said thermoplastic material to composting conditions selected from a group consisting of aerated windrows, compost piles, and conveyor systems for about 10 to about 60 days and curing the mixture of sewage sludge and mixed solid organic waste and thermoplastic material from about 7 days to about 6 months in an open compost pile.

### Claim 9 (depends on 1)

Process according to claim 1 wherein said media is garden waste and wherein said contacting step and said subjecting step are contacting said thermoplastic material with said garden waste for about 1 to about 8 weeks at temperatures of about 15.degree. C. to about 80.degree. C. under composting conditions selected from a group consisting of aerated windrows, compost piles, and conveyor systems, and wherein said process includes the further step of curing the mixture of garden waste and thermoplastic material for about 3 days to about 12 months in an open compost pile.

### Claim 10 (depends on 1)

Process according to claim 1 wherein said media is garden waste and wherein the mixture of garden waste and thermoplastic material is sprayed with a 0.1% to 5% basic solutions of manganese, copper, and iron at a rate of about 0.001% to about 3% of metal based on said waste and heated for about 1 week to about 24 months at temperatures of about 15.degree. C. to about 80.degree. C.

### Claim 11 (depends on 1)

Process according to claim 1 wherein said media is sewage sludge and mixed solid organic waste, wherein said process includes the further step of mixing said sewage sludge and said solid organic waste and said thermoplastic material with wood chips for about 5 to about 20 minutes to form a mixture thereof, and wherein said subjecting step is the step of placing said mixture over a bed of wood chips and aerating said mixture for about 1 day to about 4 weeks at temperatures of about 10.degree. C. to about 150.degree. C. and wherein said process includes the further step of curing said mixture for about 2 weeks to about 24 months in an open compost pile.

### Claim 12 (depends on 1)

Process according to claim 1 wherein said contacting step is the step of contacting said thermoplastic material with solutions of copper, manganese, cobalt and iron having a pH of 4 to 14 and having metal concentrations of 0.1 to 3% for a period of about two hours to about eight weeks and drying the thermoplastic polymer product for one minute to eight weeks at temperatures of 15.degree. C. to 150.degree. C., and wherein said subjecting step is the step of mixing the treated and dried thermoplastic material with sewage sludge, mixed solid organic waste and/or garden waste to form a mixture thereof and composting said mixture in a group consisting of aerated windrows, compost piles, and conveyor system for about five minutes to about eight weeks, and wherein said process includes the further step of curing said mixture in an open compost pile for about five days to about twelve months.

### Claim 13 (depends on 1)

Process according to claim 1 wherein the metal complexing agent contains a nonoxidizing metal and comprises materials containing --NH.sub.2, --CO--, --COO--, --SH, and --S--S-- groups, and wherein said materials are selected from the group consisting of beta-ketones, beta-ketoesters, phosphonic acids, aminocarboxylic acids, polyphosphates, hydroxycarboxylic acid, fatty acids, and polymeric type metal complexing agents including maleated polyolefins, copolymers of ethylene and acrylic acids, copolymers of ethylene and methacrylic acids, and terpolymers of ethylene, propylene, and acrylic acid.

### Claim 14 (depends on 1)

Process according to claim 1 wherein said liquid media solutions of oxidizing metals contains about 0.005 to about 5% of oxidizing metal.

### Claim 15 (depends on 14)

Process according to claim 14 wherein said liquid media solutions of oxidizing metals has a pH of 6 to 12.

### Claim 16 (depends on 1)

Process according to claim 1 wherein said sewage sludge has a solids content of about 2% to about 50%.

### Claim 17 (depends on 16)

Process according to claim 16 wherein said solids content of the sewage sludge is about 4% to about 30%.

### Claim 18 (depends on 1)

Process according to claim 1 wherein said media is a mixture of sewage sludge and mixed organic solids having a ratio of about 0.1 to about 1.8 of sewage sludge to mixed organic solids.

### Claim 19 (depends on 1)

Process according to claim 1 wherein said thermoplastic polymer product is exposed to said oxidizing metal contained in said media for a period of about 5 minutes to about 10 months at temperatures of about 0.degree. C. to about 150.degree. C., and mixed with a waste material for a period of about 1 minute to about 10 months at temperatures of about 0.degree. C. to about 150.degree. C.