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US4460729A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyester composition

Assignee: Albemarle Corp
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Filing: 1982-05-13
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Granted: 1984-07-17
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Expires: 2002-05-13
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Abstract

Abstract Improved injection moldability of polyethylene terephthalates is achieved by the addition of small amounts of (i) a poly-α-olefin and (ii) an adjuvant synergistically cooperative with the poly-α-olefin to achieve improved moldability and mold releasability even when the composition is injection molded at temperatures of at least as low as 93° C.

Inventors

  • 👤 Jeffrey T. Books

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 14:03
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 213 words
A thermoplastic composition which is injectionmoldable at a relatively low mold temperature, said composition comprising an intimate admixture of: (a) polyethylene terephthalate having an intrinsic viscosity in the range of 0.4 to 0.9 as measured at 25° C. in a solvent consisting of 60% by weight of phenol and 40% by weight of tetrachloroethane; (b) polyethylene having a viscosity within the range of from about 150 to about 700 centipoise as measured at 140° C. with a Brookfield viscometer, present in an amount within the range of from about 0.5 to about 12 parts per hundred parts of the polyethylene terephthalate; (c) an adjuvant synergistically cooperative with the polymer of (b) to improve the releasability, from the injection mold, of articles injection molded from said composition at mold temperatures of at least as low as 93° C., said adjuvant being a sodium or potassium salt of a substantially saturated aliphatic monocarboxylic acid containing from about 12 to about 36 carbon atoms in the molecule present in an amount within the range of from about 0.05 to about 5 parts per hundred parts of the polyethylene terephthalate; and (d) at least one reinforcing filler present in amount of from about 10 to about 160 parts per 100 parts by weight of the polyethylene terephthalate.
Claim 2
Dependent Claim 213 words
A thermoplastic composition which is injectionmoldable at a relatively low mold temperature, said composition comprising an intimate admixture of: (a) polyethylene terephthalate having an intrinsic viscosity in the range of 0.4 to 0.9 as measured at 25° C. in a solvent consisting of 60% by weight of phenol and 40% by weight of tetrachloroethane; (b) polyethylene having a viscosity within the range of from about 150 to about 700 centipoise as measured at 140° C. with a Brookfield viscometer, present in an amount within the range of from about 0.5 to about 12 parts per hundred parts of the polyethylene terephthalate; (c) an adjuvant synergistically cooperative with the polymer of (b) to improve the releasability, from the injection mold, of articles injection molded from said composition at mold temperatures of at least as low as 93° C., said adjuvant being a sodium or potassium salt of a substantially saturated aliphatic monocarboxylic acid containing from about 12 to about 36 carbon atoms in the molecule present in an amount within the range of from about 0.05 to about 5 parts per hundred parts of the polyethylene terephthalate; and (d) at least one reinforcing filler present in amount of from about 10 to about 160 parts per 100 parts by weight of the polyethylene terephthalate.
Claim 3
Dependent Claim 12 words
The composition of claim 1 wherein said salt is a sodium salt.
Claim 4
Dependent Claim 11 words
The composition of claim 1 wherein said salt is sodium stearate.
Claim 5
Dependent Claim 12 words
The composition of claim 1 wherein said reinforcing filler is glass fibers.
Claim 6
Dependent Claim 58 words
The composition of claim 1 wherein said polethylene is present in an amount within the range of from about 2 to about 8 parts per hundred parts by weight of said polyethylene terephthalate and said adjuvant is present in an amount of from about 0.1 to about 3 parts per hundred parts by weight of said polyethylene terephthalate.

References Cited (Backward Citations)

GB993770A Cited
GB1104089A Cited
GB1208585A Cited
US3575931A Cited
US3673139A Cited
US3769260A Cited
US4122061A Cited
US4290937A Cited
US4219628A Cited
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US4327007A Cited
US4327198A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-17 1988-01-16 1988-07-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-17 1992-01-16 1992-07-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-17 1996-01-16 1996-07-17 $7700.00 Window Closed / Lapsed

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