US5231121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Natural fiber containing molding compounds based on unsaturated polyester resins, and molded bodies obtained from the molding compounds
Assignee: Covestro Resins BV
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Filing: 1992-01-29
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Granted: 1993-07-27
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Expires: 2012-01-29
Abstract
Abstract Molding compositions based on unsaturated polyester (UP) resins and containing natural fibers are prepared from which molded parts can be produced by hot pressing. The molded parts have a residual styrene content <0.1 wt. %. The UP resins are comprised of a customary UP and a mixture of styrene and di(meth)acrylic acid ester(s).
Inventors
- 👤 Horst Kramer
- 👤 Johannes Stawowy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:00
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; C08J5/045; C08L; C08L67/00; C08L67/06; C08J2367/00; C08J2367/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A method of reducing the residual styrene content to less than 0.1 wt. % and the residual di(meth)acrylic acid ester content to less than 0.05 wt. % in a molded article prepared from a molding composition containing unsaturated polyester and styrene, comprising: preparing a formulation of unsaturated polyester, a mixture of from 1-85 wt. % styrene and 99-15 wt. % of di(meth) acrylic acid ester of a (cyclo)aliphatic diol, and optionally at least one additive selected from the group consisting of fillers and inhibitors; impregnating a natural fiber material with said formulation; hot pressing the combined materials which polymerizes the unsaturated components of the combined materials, thereby preparing a molded object of desired shape.
Claim 2
Independent Claim
114 words
A method of reducing the residual styrene content to less than 0.1 wt. % and the residual di(meth)acrylic acid ester content to less than 0.05 wt. % in a molded article prepared from a molding composition containing unsaturated polyester and styrene, comprising: preparing a formulation of unsaturated polyester, a mixture of from 1-85 wt. % styrene and 99-15 wt. % of di(meth) acrylic acid ester of a (cyclo)aliphatic diol, and optionally at least one additive selected from the group consisting of fillers and inhibitors; impregnating a natural fiber material with said formulation; hot pressing the combined materials which polymerizes the unsaturated components of the combined materials, thereby preparing a molded object of desired shape.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein said natural fibers are selected from the group consisting of jute, sisal and flax.
Claim 4
Dependent Claim
27 words
The method of claim 1, wherein the weight ratio of natural fiber to the weight of polyester, styrene and di(meth) acrylic acid ester is 1.5:1 to 1:1.5.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein said natural fibers comprise a jute mat.
Claim 6
Dependent Claim
34 words
The method of claim 1, wherein said mixture comprises 3 less than 30 wt. % styrene and 97 to greater than 70 wt. % of a di(meth) acrylic acid ester of a (cyclo)aliphatic diol.
Claim 7
Dependent Claim
12 words
The method of claim 1, wherein said diol contains 2-9 carbon atoms.
Claim 8
Dependent Claim
38 words
The method of claim 1, wherein said mixture comprises 3 to less than 30 wt. % styrene and 97 to greater than 70 wt. % of a dimethacrylic acid ester of an aliphatic diol having 2-9 carbon atoms.
Claim 9
Dependent Claim
18 words
The method of claim 1, where said diol is 1,4-di(hydroxymethyl)cyclohexane, diethylene glycol, tripropylene glycol, 1,4-butanediol and mixtures thereof.
Claim 10
Dependent Claim
11 words
The method of claim 1, wherein said ester is 1,4-butanediol dimethacrylate.
Claim 11
Dependent Claim
21 words
The method of claim 1, wherein said polyester comprises 40-70 wt. % of the weight of said polyester and said mixture.
Claim 12
Dependent Claim
21 words
The method of claim 1, wherein said polyester comprises 45-60 wt. % of the weight of said polyester and said mixture.
References Cited (Backward Citations)
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US4129543A
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US4290939A
Cited
US4895895A
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JPS63268722A
Cited
US5077326A
Cited
US5075393A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-26 | 1997-01-25 | 1997-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-26 | 2001-01-25 | 2001-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-26 | 2005-01-25 | 2005-07-27 | $7700.00 | Window Closed / Lapsed |