Polymer compositions providing low residue levels and methods of use thereof
AssigneeMetabolix, Inc.
InventorsDANIEL M. HOROWITZ, ELAINE M. BRENNAN
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Abstract
Polymer emulsion compositions presenting low levels of residue after thermolytic decomposition are provided. The compositions, based on polyhydroxyalkanoates or acrylics, are useful in a variety of applications, including the metallization of cathode ray tube phosphor screens, where use of the compositions provides enhanced luminosity and ease of manufacture. Other applications include use of the emulsion in additives used in powder molding techniques and in the manufacture of ceramic tiles.
Claims30
A composition comprising an aqueous emulsion of a polymer selected from the group consisting of (i) acrylics having units of formula:
- —Ch2—CR1Co2R2—,
- wherein R1 and R2 are any radical of formula Cn H2n+1
- and wherein n is an integer from 0 to 10;
- (ii) polyhydroxyalkanoates;
- and mixtures thereof,
- wherein the emulsion is prepared to render the emulsion substantially free of non-volatilizable substances.
A method for making a composition comprising an aqueous emulsion of a polymer substantially free of non-volatilizable substances, the method comprising:
- (a) preparing an aqueous emulsion of a polymer selected from the group consisting of (i) acrylics having units of formula:
- —CH2—CR1CO2R2—,
- wherein R1 and R2 are any radical of formula Cn H2n+1
- and wherein n is an integer from 0 to 10,
- (ii) polyhydroxyalkanoates, and mixtures thereof, wherein the emulsion contains non-volatilizable substances;
- and
- (b) removing substantially all of the non-volatilizable substances from the emulsion.
A method of metallizing a phosphor screen for use in cathode-ray tube phosphor screens, the method comprising:
- (a) depositing onto the phosphor screen a composition comprising an aqueous emulsion of a polymer selected from the group consisting of (i) acrylics having units of formula:
- —CH2—CR1CO2R2—,
- wherein R1 and R2 are any radical of formula Cn H2n+1
- and wherein n is an integer from 0 to 10;
- (ii) polyhydroxyalkanoates;
- and mixtures thereof,
- wherein the emulsion is substantially free of non-volatilizable substances,
- (b) drying the emulsion to form a solid substrate;
- (c) applying a metallic layer to the solid substrate;
- and
- (d) volatilizing the solid substrate by thermal means.
The method of step 21 wherein step (d) is conducted during sealing of a funnel assembly of a cathode-ray tube to the phosphor screen.
A method of forming a shaped product having reduced processing additive residue, the method comprising:
- (a) compounding a powdered material with a processing additive comprising an aqueous emulsion of a polymer selected from the group consisting of (i) acrylics having units of formula:
- —CH2—CR1CO2R2—,
- wherein R1 and R2 are any radical of formula Cn H2n+1
- and wherein n is an integer from 0 to 10;
- (ii) polyhydroxyalkanoates;
- and mixtures thereof
- wherein the emulsion is substantially free of non-volatilizable substances, to form an admixture;
- (b) molding the admixture to form the shaped product;
- and
- (c) thermally decomposing the additive.
A molded article formed by a method comprising molding a composition comprising a powdered material admixed with an aqueous emulsion of a polymer selected from the group consisting of (i) acrylics having units of formula:
- —CH2—CR1CO2R2—,
- wherein R1 and R2 are any radical of formula Cn H2n+1
- and wherein n is an integer from 0 to 10;
- (ii) polyhydroxyalkanoates;
- and mixtures thereof,
- wherein the emulsion is substantially free of non-volatilizable substances.
Dependencies are inferred from the claim text.