Patent US4352892A successfully refreshed from Google Patents.
US4352892A
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US
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Method for the manufacture of lightweight foam materials from crystalline thermoplastic materials and the resultant products
Assignee: Carl Freudenberg KG
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Filing: 1980-03-10
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Granted: 1982-10-05
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Expires: 2000-03-10
Abstract
Abstract This application is directed to light-weight and hard foam materials. The foams of this invention are prepared by extruding thermoplastic crystalline plastics in the presence of highly volatile organic liquids as the foaming agents. In accordance with the present method crystalline polyolefins, in the presence of polybutadiene, ethylenevinylacetate copolymers, ethylene-propylenes and/or ethylene-propylene terpolymer rubbers, and optionally radical formers such as suitable peroxides, azidene, sulfonyl azidene or the like, and inhibitors for radical decomposition, such as triallylcyanurate or an acrylate selected from the group consisting of trimethylolpropane-trimethacrylate, allyl-methacrylate, tetrahydrofurfurylmethacrylate, triethyleneglycol-dimethacrylate, polyethyleneglycol-dimethacrylate or the like, are converted into foam-like molded bodies by means of a highly volatile organic liquid foaming agent. The foaming agent is employed in an amount of from about 5 to about 30% by weight, based on the weight of the polyolefins. The foaming agent and the polyolefins are mixed in an extruder at a temperature of from about 180° to about 280° C., and at a pressure which is greater than the vapor pressure of the foaming agent. The mixture is subsequently extruded.
Inventors
- 👤 Ernst Lohmar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:05
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J9/04; C08J9/12; C08J9/127; C08J9/14; C08J9/143; C08J9/147; C08J2203/00; C08J2203/14; C08J2203/142; C08J2323/00; C08J2323/02; C08J2409/00; C08J2423/00; C08J2423/02; C08J2423/16; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/18; Y10S521/00; Y10S521/91; Y10S521/915
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
186 words
A method of preparing a lightweight foam material which comprises: (a) forming a melt of a crystalline polyolefin in the presence of about 2 to 20 percent by weight of said crystalline polyolefin of a second polyolefin component in an extruder; wherein said second polyolefin component is selected from the group consisting of polybutadiene, an ethylene vinylacetate copolymer and an ethylene-propylene terpolymer; said melt including a radical former and a radical decomposition inhibitor wherein said radical decomposition inhibitor is selected from the group consisting of: trimethylolpropanetrimethacrylate, allyl-methacrylate, tetrahydrofurylmethacrylate, triethyleneglycol-dimethacrylate and polyethylene glycol-dimethylacrylate; and (b) injecting a volatile organic solvent foaming agent into said melt, said foaming agent comprising from about 5 to 30% by weight of said polyolefins and wherein said foaming agent and said melt are mixed at a temperature of about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of the foaming agent, followed by (c) extruding said melt and foaming agent from said extruder to provide a foam product having a specific bulk weight of from about 30 to about 200 kg/m 3 .
Claim 2
Independent Claim
186 words
A method of preparing a lightweight foam material which comprises: (a) forming a melt of a crystalline polyolefin in the presence of about 2 to 20 percent by weight of said crystalline polyolefin of a second polyolefin component in an extruder; wherein said second polyolefin component is selected from the group consisting of polybutadiene, an ethylene vinylacetate copolymer and an ethylene-propylene terpolymer; said melt including a radical former and a radical decomposition inhibitor wherein said radical decomposition inhibitor is selected from the group consisting of: trimethylolpropanetrimethacrylate, allyl-methacrylate, tetrahydrofurylmethacrylate, triethyleneglycol-dimethacrylate and polyethylene glycol-dimethylacrylate; and (b) injecting a volatile organic solvent foaming agent into said melt, said foaming agent comprising from about 5 to 30% by weight of said polyolefins and wherein said foaming agent and said melt are mixed at a temperature of about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of the foaming agent, followed by (c) extruding said melt and foaming agent from said extruder to provide a foam product having a specific bulk weight of from about 30 to about 200 kg/m 3 .
Claim 3
Dependent Claim
57 words
The method according to claim 1 wherein said crystalline polyolefin is polypropylene, and said mixture comprising said melt further includes a radical former which is selected from the group consisting of peroxide, azidene, or sulfonyl azidene radical formers, and wherein said second polyolefin component is polybutadiene, having a molecular weight of from about 1000 to 3000 g/mol.
Claim 4
Dependent Claim
21 words
The method according to claim 1 wherein said liquid polybutadienes have molecular weights of from about 500 to about 10,000 g/mol.
Claim 5
Dependent Claim
21 words
The method according to claim 3 wherein said liquid polybutadienes have molecular weights of from about 1,000 to about 3,000 g/mol.
Claim 6
Dependent Claim
18 words
The method according to claim 4 wherein said polybutadienes have a vinylpolybutadiene content of at least about 35%.
Claim 7
Dependent Claim
17 words
The method according to claim 5 wherein said vinylpolybutadiene content is from about 85 to about 95%.
Claim 8
Independent Claim
16 words
The method according to claims 1 or 4 wherein said polybutadienes have carboxyl or hydroxyl substituents.
Claim 9
Dependent Claim
28 words
The method according to claim 1 wherein said polypropylene and said polybutadienes are fed into said extruder between the charging opening of the extruder and about 15 D.
Claim 10
Dependent Claim
63 words
The method according to claim 1 wherein said crystalline polyolefins are foamed in the presence of polybutadienes by means of volatile fluorocarbon foaming agents, said foaming agents being present in an amount of from about 5 to about 20 weight % of said mixture; and wherein said crystalline polyolefins and said polybutadiene are fed into said extruder between 2 D and 15 D.
Claim 11
Dependent Claim
22 words
The light-weight foam prepared in accordance with the method of claims 3 or 4 or 5 or 6 or 1 or 2.
Claim 12
Dependent Claim
12 words
The light-weight foam prepared in accordance with the method of claim 7.
Claim 13
Dependent Claim
14 words
The light-weight foam prepared in accordance with the method of claims 8 or 9.
Claim 14
Dependent Claim
9 words
The light-weight foam prepared in accordance with claim 8.
Claim 15
Independent Claim
141 words
A method of preparing a light-weight foam material which comprises: (a) forming a melt in an extruder of a crystalline polypropylene in the presence of a radical former selected from the group consisting of the peroxide, azidene and sulfonyl azidene radical formers, said melt also including a radical decomposition inhibitor which is polybutadiene; and (b) injecting from about 5 to about 30% by weight of a volatile organic solvent foaming agent into said melt, wherein said foaming agent and said melt are mixed at a temperature of about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of said foaming agent; followed by (c) extruding said melt and foaming agent from said extruder to provide a foam product having a specific bulk weight of from about 30 to about 200 kg/m 3 .
Claim 16
Independent Claim
141 words
A method of preparing a light-weight foam material which comprises: (a) forming a melt in an extruder of a crystalline polypropylene in the presence of a radical former selected from the group consisting of the peroxide, azidene and sulfonyl azidene radical formers, said melt also including a radical decomposition inhibitor which is polybutadiene; and (b) injecting from about 5 to about 30% by weight of a volatile organic solvent foaming agent into said melt, wherein said foaming agent and said melt are mixed at a temperature of about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of said foaming agent; followed by (c) extruding said melt and foaming agent from said extruder to provide a foam product having a specific bulk weight of from about 30 to about 200 kg/m 3 .
Claim 17
Dependent Claim
24 words
The method according to claim 14 wherein said polybutadiene is a liquid polybutadiene having a molecular weight of from about 1,000 to about 3,000.
Claim 18
Dependent Claim
18 words
The method according to claim 14 or 15 wherein said polybutadiene has at least about a 35% 1,2-content.
Claim 19
Dependent Claim
18 words
The method according to claim 16 wherein said polybutadiene has a 1,2-content of about 80 to about 95%.
Claim 20
Dependent Claim
12 words
The method according to claim 14 wherein said polypropylene is isotactic polypropylene.
Claim 21
Dependent Claim
77 words
The method according to claim 18 wherein said isotactic polypropylene is foamed in the presence of radical formers and radical decomposition inhibitors, wherein said radical formers are employed in an amount corresponding to from about 0.1 to about 5.0 weight %, based on the weight of said isotactic polypropylenes; and said radical decomposition inhibitors are employed in an amount corresponding to from about 0.1 to about 10 weight %, based on the weight of said isotactic polypropylenes.
Claim 22
Dependent Claim
26 words
The method according to claim 14 wherein said radical formers comprise from about 0.1 to about 5.0 percent based on the weight of said polypropylene component.
Claim 23
Independent Claim
61 words
The method according to claims 14 or 15 or 16 or 17 wherein said polypropylene and polybutadiene are foamed by means of a volatile fluorocarbon foaming agent, said foaming agent comprising from about 5 to about 20% by weight of said polypropylene and polybutadiene, and said polybutadiene and polypropylene are fed into said extruder between about 2 D and 15 D.
Claim 24
Dependent Claim
28 words
The method according to claim 14 wherein said polypropylene and said polybutadiene are fed into said extruder between the charging opening of said extruder and about 15 D.
Claim 25
Dependent Claim
62 words
The method according to claim 14 wherein said melt of step (a) comprises about 4 to about 7 weight percent of a polybutadiene having a molecular weight of about 3,000; about 0.4 to about 0.8 weight percent of a radical former; and a pore regulator, said foam having a specific bulk gravity of from about 30 to about 200 kg/m 3 .
Claim 26
Dependent Claim
26 words
The method according to claim 14 wherein said polypropylene comprises a polypropylene having a molecular weight distribution of from about 200 kg/mole to about 800 kg/mole.
Claim 27
Dependent Claim
18 words
The method according to claim 14 wherein said polypropylene has an average molecular weight of about 400 kg/mole.
Claim 28
Dependent Claim
24 words
The method according to claim 14 wherein said foam has a specific bulk gravity of from about 30 to about 200 kg/m 3 .
Claim 29
Independent Claim
125 words
A method of preparing a light-weight foam material which comprises: (a) forming a melt in an extruder of a crystalline polypropylene and about 2 to 20 percent by weight of the polypropylene of a polybutadiene polymer; and (b) injecting a volatile organic solvent foaming agent into said melt, said foaming agent comprising from about 5 to about 30% by weight of said polypropylene and polybutadiene, and wherein said foaming agent and said melt are mixed at a temperature of from about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of the foaming agent; followed by (c) extruding said melt to provide a foam, and then (d) cross-linking said foam by subjecting it to electron beam irradiation.
Claim 30
Independent Claim
125 words
A method of preparing a light-weight foam material which comprises: (a) forming a melt in an extruder of a crystalline polypropylene and about 2 to 20 percent by weight of the polypropylene of a polybutadiene polymer; and (b) injecting a volatile organic solvent foaming agent into said melt, said foaming agent comprising from about 5 to about 30% by weight of said polypropylene and polybutadiene, and wherein said foaming agent and said melt are mixed at a temperature of from about 180° C. to about 280° C., and at a pressure which is greater than the vapor pressure of the foaming agent; followed by (c) extruding said melt to provide a foam, and then (d) cross-linking said foam by subjecting it to electron beam irradiation.
Claim 31
Dependent Claim
24 words
The method according to claim 27 wherein said foam is cross-linked by irradiation with electron rays of from about 0.5 to about 20 Mrad.
Claim 32
Dependent Claim
29 words
The method according to claim 27 wherein said foam is cross-linked by irradiation to the extent that it exhibits a gel content of from about 10 to about 100%.
Claim 33
Dependent Claim
14 words
The foam product prepared in accordance with the method of claims 14 or 27.
Claim 34
Dependent Claim
9 words
The light-weight foam prepared in accordance with claim 28.
Claim 35
Dependent Claim
9 words
The light-weight foam prepared in accordance with claim 29.
References Cited (Backward Citations)
US3240727A
Cited
US3137745A
Cited
US3250731A
Cited
US3452123A
Cited
US3341480A
Cited
US3407253A
Cited
GB1212291A
Cited
US3696059A
Cited
US3709806A
Cited
US3939237A
Cited
US3981830A
Cited
US3965054A
Cited
US4142956A
Cited
US4166890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |