# US 2013/0158228 A1 · Ethylene terephthalate type polyester resin for forming containers and process for producing the same

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- Number: US 2013/0158228 A1
- Document ID: US20130158228A1
- Status: Published application
- Kind: A1
- Application number: 13/770,244
- Filed: 2013-02-19
- Published: 2013-06-20
- Earliest claimed: 2008-12-26
- Assignees: Toyo Seikan Kaisha, Ltd.
- Inventors: Kazuhiko NAKAMURA; Yoshihiro KITANO; Atsushi KIKUCHI
- Web page: https://patentgrep.com/patent/US20130158228A1

## CPC

- C08G 63/183: Terephthalic acids
- B29C 49/0872: {axial stretch ratio}
- C08G 63/88: Post-polymerisation treatment
- B29K 2067/00: Use of polyesters {or derivatives thereof}, as moulding material
- B29L 2031/716: {of the wide mouth type, i.e. the diameters of the bottle opening and its body are substantially identical}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

Ethylene terephthalate polyester resin for forming containers, having intrinsic viscosity of 0.65 to 0.85 dL/g, a content of a monohydroxyethyl terephthalate and a bishydroxyethyl terephthalate of less than 0.005% by weight, (a) a heat of fusion of not more than 50 J/g an end temperature of melting peak of not higher than 270° C. and a crystallinity of less than 0.48, or (b) an acetaldehyde concentration of 2 to 10 ppm, and satisfying at least either one of (i) a peak time of crystallization is not longer than 360 seconds and the crystallization energy is not less than 30 J/g in the isothermal crystallization at 210° C., or (ii) components having molecular weights of not larger than 10000 are contained in not less than 8%. The polyester resin effectively prevents problems metal mold fouling in forming containers or a decrease in productivity.

## Claims

### Claim 1

An ethylene terephthalate type polyester resin for forming heat-resistant containers, having an intrinsic viscosity in a range of 0.65 to 0.80 dL/g, a total content of a monohydroxyethyl terephthalate and a bishydroxyethyl terephthalate of less than 0.005% by weight, an acetaldehyde concentration of 2 to 10 ppm, and satisfying at least either one of:
(i) a peak time of crystallization is not longer than 360 seconds and the energy of crystallization (ΔH) is not less than 30 J/g in the isothermal crystallization at 210° C.; or
(ii) components having molecular weights of not larger than 10000 are contained in not less than 8%.

### Claim 2 (depends on 1)

The ethylene terephthalate type polyester resin for forming heat-resistant containers according to claim 1, wherein the total amount of a diethylene glycol and an isophthalic acid contained as copolymerizable components is not more than 1.5% by weight.

### Claim 3 (depends on 1)

A preform comprising the ethylene terephthalate type polyester resin of claim 1, and having an intrinsic viscosity in a range of 0.65 to 0.80 dL/g, a total content of the monohydroxyethyl terephthalate and the bishydroxyethyl terephthalate of less than 0.010% by weight, an acetaldehyde concentration of not more than 15 ppm, a peak time of crystallization of not longer than 60 seconds and the crystallization energy (ΔH) of not less than 20 J/g in the isothermal crystallization at 210° C.

### Claim 4 (depends on 3)

The preform according to claim 3, wherein the total amount of a diethylene glycol and an isophthalic acid contained as copolymerizable components is not more than 2.7% by weight.

### Claim 5

A process for producing an ethylene terephthalate type polyester resin by heat-treating an ethylene terephthalate type polyester resin, which is obtained by the melt state polymerization, at a temperature of 160 to 220° C. for not less than 1 hour but less than 5 hours.