Patent US4139575A successfully refreshed from Google Patents.
US4139575A
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US
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Polyoxymethylene molding composition containing melamine formaldehyde polycondensate
Assignee: Evonik Operations GmbH
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Filing: 1976-08-19
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Granted: 1979-02-13
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Expires: 1996-08-19
Abstract
Abstract In a molding composition comprising a polyoxymethylene, a melamine formaldehyde polycondensate and an antioxidation agent, the improvement wherein said melamine formaldehyde polycondensate is a finely divided, cross-linked, substantially water insoluble polycondensate comprising the precipitation product obtained by reacting formaldehyde and melamine in a molar ratio between 1.2 : 1 and 10.0 : 1; and wherein said polycondensate is in an amount of about 0.001 to about 30 percent by weight, related to the total weight of said composition.
Inventors
- 👤 Herbert Amann
- 👤 Gerhard Morlock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:59
CPC Classifications
C; C08; C08L; C08L59/00; C08L59/02; C08L61/00; C08L61/20; C08L61/26; C08L61/28
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
74 words
In a molding composition comprising a polyoxymethylene, a melamine formaldehyde polycondensate and an antioxidation agent, the improvement wherein said melamine formaldehyde polycondensate is a finely divided, cross-linked substantially water insoluble polycondensate comprising the precipitation product obtained by reacting formaldehyde and melamine in a molar ratio between 1.2:1 and 10.0:1; and wherein said polycondensate is in an amount of about 0.001 to about 30 percent by weight, related to the total weight of said composition.
Claim 2
Dependent Claim
74 words
In a molding composition comprising a polyoxymethylene, a melamine formaldehyde polycondensate and an antioxidation agent, the improvement wherein said melamine formaldehyde polycondensate is a finely divided, cross-linked substantially water insoluble polycondensate comprising the precipitation product obtained by reacting formaldehyde and melamine in a molar ratio between 1.2:1 and 10.0:1; and wherein said polycondensate is in an amount of about 0.001 to about 30 percent by weight, related to the total weight of said composition.
Claim 3
Dependent Claim
15 words
Composition according to claim 1 wherein said composition includes at least one polyoxymethylene molding additive.
Claim 4
Dependent Claim
139 words
Composition according to claim 1 wherein said polyoxymethylene has a crystalline melting point of about 140° C. to about 180° C., a density of about 1.38 to about 1.45 g/ml (DIN 53 479), and a viscosity of at least about 30 ml/g when measured at 135° C. with a solution of 0.5 g polyoxymethylene in 100 ml dimethylformamide containing 2% by weight diphenylamine; said polycondensate has a primary particle size less than about 1 μm, a specific surface up to about 250 m 2 /g, and which comprises the product obtained by reacting said formaldehyde and said melamine in an aqueous solution or dispersion to form a soluble precondensate, and then precipitating and cross-linking said soluble precondensate; and said antioxidant is in an amount of about 0.001 to about 2% by weight, related to the weight of said polyoxymethylene.
Claim 5
Dependent Claim
23 words
Composition according to claim 3 wherein at least a portion of said polycondensate has a primary particle size less than about 0.1 μm.
Claim 6
Dependent Claim
28 words
Composition according to claim 1 wherein said polycondensate is in an amount of about 0.1 to about 5% by weight, related to the total weight of said composition.
Claim 7
Dependent Claim
28 words
Composition according to claim 1 wherein said polycondensate is in an amount of about 0.08 to about 1.0% by weight, related to the total weight of said composition.
Claim 8
Dependent Claim
19 words
Composition according to claim 1 wherein the mole ratio of formaldehyde: melamine is between about 1.2:1 and about 2.0:1.
Claim 9
Dependent Claim
24 words
Composition according to claim 1 wherein cross-linking to said melamine formaldehyde polycondensate is carried out at a pH of about 5.0 to about 6.9.
Claim 10
Dependent Claim
24 words
Composition according to claim 1 wherein cross-linking of said melamine formaldehyde polycondensate is carried out at a pH of about 6.0 to about 6.9.
Claim 11
Dependent Claim
17 words
Composition according to claim 1 wherein said cross-linking is carried out in the presence of a buffer.
Claim 12
Dependent Claim
22 words
Composition according to claim 1 wherein said polyoxymethylene is a homopolymer of formaldehyde, a homopolymer of trioxane or a copolymer of trioxane.
Claim 13
Dependent Claim
44 words
Composition according to claim 2 wherein said molding additive is selected from the group consisting of heat stabilizing agents; UV absorbers and light protective agents; fillers; reinforcing agents; lubricants; auxiliary processing agents; nucleating agents; pigments; dyes; and fire-retardant agents, or mixtures of these substances.
Claim 14
Dependent Claim
16 words
Composition according to claim 1 in which said polyoxymethylene is a copolymer of trioxane and 1,3-dioxepane.
Claim 15
Dependent Claim
83 words
In a molding composition comprising a polyoxymethylene, a melamine formaldehyde polycondensate and an antioxidation agent, the improvement wherein said melamine formaldehyde polycondensate is a cross-linked, substantially water insoluble polycondensate having a particle size of less than about 10 μm, said polycondensate comprising a precipitation product obtained by reacting formaldehyde and melamine in a molar ratio between 1.2:1 and 10.0:1; and wherein said polycondensate is in an amount of about 0.001 to about 30% by weight related to the total weight of said composition.
Claim 16
Dependent Claim
83 words
In a molding composition comprising a polyoxymethylene, a melamine formaldehyde polycondensate and an antioxidation agent, the improvement wherein said melamine formaldehyde polycondensate is a cross-linked, substantially water insoluble polycondensate having a particle size of less than about 10 μm, said polycondensate comprising a precipitation product obtained by reacting formaldehyde and melamine in a molar ratio between 1.2:1 and 10.0:1; and wherein said polycondensate is in an amount of about 0.001 to about 30% by weight related to the total weight of said composition.
Claim 17
Dependent Claim
16 words
Composition according to claim 14 in which said particle size is less than about 5 μm.
Claim 18
Dependent Claim
16 words
Composition according to claim 15 in which said particle size is less than about 2 μm.
Claim 19
Dependent Claim
13 words
Composition according to claim 1 wherein said composition contains a mixture of polyoxymethylenes.
Claim 20
Dependent Claim
13 words
Composition according to claim 1 wherein said composition contains a mixture of antioxidants.
Claim 21
Dependent Claim
10 words
A molded article comprised of the composition of claim 1.
Claim 22
Dependent Claim
10 words
A molded article comprised of the composition of claim 14.
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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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |