WO1990002151A1 - Improved expandable and expanded alkenyl aromatic polymer particles and methods of making the same - Google Patents

Improved expandable and expanded alkenyl aromatic polymer particles and methods of making the same Download PDF

Info

Publication number
WO1990002151A1
WO1990002151A1 PCT/US1989/002576 US8902576W WO9002151A1 WO 1990002151 A1 WO1990002151 A1 WO 1990002151A1 US 8902576 W US8902576 W US 8902576W WO 9002151 A1 WO9002151 A1 WO 9002151A1
Authority
WO
WIPO (PCT)
Prior art keywords
alkenyl aromatic
aromatic polymer
expanded
percent
expandable
Prior art date
Application number
PCT/US1989/002576
Other languages
French (fr)
Inventor
Martin H. Tusim
Original Assignee
The Dow Chemical Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Dow Chemical Company filed Critical The Dow Chemical Company
Priority to BR898907615A priority Critical patent/BR8907615A/en
Publication of WO1990002151A1 publication Critical patent/WO1990002151A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/0014—Use of organic additives
    • C08J9/0023—Use of organic additives containing oxygen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2325/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Derivatives of such polymers

Definitions

  • This, invention relates to improved expandable and expanded alkenyl aromatic polymer particles and methods for preparing these expandable and expanded particles.
  • Alkenyl aromatic polymer particles or beads which are expandable or expanded, are known to be highly desirable for a number of uses.
  • One highly desirable use is protection in packaging articles for shipping.
  • Another use for the expandable alkenyl aromatic polymer particles is as molding material.
  • expanded alkenyl aromatic polymer particles are highly desirable, they suffer from a substantial and significant problem of the high cost of shipping in the expanded state due to their very low bulk density. It is therefore generally desirable to ship a product having a maximum bulk density, as an expandable alkenyl aromatic polymer particle, and to subsequently expand the particle at or near the point of use into the desired form such as expanded alkenyl aromatic polymer packaging particles or expanded and molded alkenyl aromatic polymer foamed objects.
  • blowing agent used to prepare the expandable and expanded alkenyl aromatic polymer particles, especially if the blowing agent is a blowing agent which 5 is believed to cause damage to the earth's atmospheric laye .
  • the present invention provides expandable particles comprising an alkenyl aromatic polymer, a 0 volatile fluid blowing agent and a density modifier in an amount from 0.005 percent to 0.5 percent by weight of the total mixture.
  • the present invention provides also expanded particles comprising an alkenyl aromatic polymer and a density modifier in an amount from 0.005 5 percent to 0.5 percent by weight of the total mixture.
  • alkenyl aromatic polymer being a polymer or copolymer having in chemically combined form at least 50 percent by weight styrene.
  • the expandable particles of the present invention are thermoplastic resinous materials containing a density modifier and a blowing agent.
  • the expanded particles of the present invention are the
  • thermoplastic resinous materials containing a density modifier.
  • the present invention provides expandable and expanded alkenyl aromatic polymer particles with the e - term alkenyl aromatic polymer including polymers or copolymers having in chemically combined form at least 50 percent by weight of at least one alkenyl aromatic compound having the general formula
  • Ar represents an aromatic hydrocarbon radical or an aromatic halohydrocarbon radical of the benzene _,,- series and R is hydrogen or the methyl radical.
  • alkenyl aromatic resins examples include the solid homopolymers of styrene, ⁇ -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ar-ethylstyrene, ar-vinylxylene, ar-chlorostyrene, or ar-bromostyrene; and the solid copolymers of two or more of such alkenyl aromatic compounds with minor amounts of other readily polymerizable olefinic compounds such as divinylbenzene, methylmethacrylate or acrylonitrile.
  • the alkenyl aromatic polymer is polystyrene having an weight-average molecular weight (M w ) of 100,000 to 300,000.
  • the volatile fluid foaming agents can be gases such as carbon dioxide, a saturated aliphatic hydrocarbon such as butane, isobutane, pentane, isopentane, neopentane, hexane, heptane or mixtures of one or more aliphatic hydrocarbons having a molecular weight of at least 65 and a boiling point not higher than 95° centigrade (C) at 760 millimeters absolute pressure.
  • Other suitable fluid foaming agents are those halogenated hydrocarbons generally known in the art.
  • the volatile fluid foaming agent usually is employed in amounts corresponding to from 5 to 15 percent of the weight of the total formulation. After expansion the volatile fluid blowing agent may .or may not be retained in the expanded alkenyl aromatic polymer particle.
  • alkenyl aromatic polymer/blowing agent mixture other additives which are known in the art such as fire retardants, stabilizers, fillers, anti-static agents and colorants. Also those materials known as "cell-size control additives" may be incorporated into the alkenyl aromatic polymer/blowing agent mixture for use in the production of uniform extruded foam prior to extrusion from a die.
  • expandable alkenyl aromatic polymer particles produced may be in any form, particularly preferred are those forms suitable for packaging or dunnage purposes and those forms which after expansion are suitable for molding purposes.
  • the present invention requires the inclusion of a density modifier in a heat-plastified alkenyl aromatic polymer/blowing agent mixture in an amount of from 0.005 weight percent to 0.5 weight percent by total mixture weight.
  • the preferred ranges are from 0.01 to 0.3 weight percent by total mixture weight.
  • the "density modifier” is defined as a compound providing thermal stability for the alkenyl aromatic polymer at extrusion and expansion conditions and which is also a liquid plasticizer at expansion conditions.
  • density modifiers include, but are not limited to, octadecyl 3»5-di-tert-butyl-4-hydroxyhydrocinnamate and ethylene bis(oxyethylene) bis(3-tert-butyl-4-hydroxy-5- methylhydrocinnamate) .
  • CFC-11 is trichlorofluoromethane.
  • Blowing Agent 8.8 percent (80 percent/20 percent CFC-11 /Pentane - weight percents based on weight of blowing agent mixture)
  • the Example formulation differs only in the octadecyl 3»5-di-tert-butyl-4-hydroxyhydrocinnamate being present in an amount of about 0.2 percent and the reduced amount of about 8.8 percent blowing agent, instead of 10.1 percent to 10.3 percent blowing agent as is in the Comparative Example.
  • After producing these expandable polystyrene particles these samples are then expanded in an atmospheric steam chamber for controlled periods of time at a temperature generally ranging from about 85°C to about 105°C, preferably about 100°C.
  • the expansion scheme will consist of a 3 minute exposure followed by a 24 hour aging time at room conditions, then a second 3 minute exposure followed by a second 24 hour aging time, and then a third 1-1/2 minute exposure and a third 24 hour aging time. After this third aging period the bulk densities of the expanded polystyrene particles are measured. This expansion scheme is followed to produce expanded polystyrene particles.
  • the Comparative Example expanded polystyrene particle bulk densities range from 0.28 to 0.33 pounds per cubic foot (4.5-5.3 kg/m ⁇ ).
  • the Example expanded polystyrene particles of the present invention have a bulk density of about 0.26 pounds per cubic foot (4.2 g/ ⁇ -3).
  • blowing agent The ability to maintain an equivalent density with a decreased amount of blowing agent is found to be a result solely from the inclusion of the octadecyl 3»5- di-tert-butyl-4-hydroxyhydrooinnamate in an amount of about 0.2 percent, as stated in the Example into the expandable polystyrene particle formulation. Generally a blowing agent decrease will produce an expanded polystyrene particle of higher density than when less blowing agent is included, not a lower density.

Abstract

The present invention relates to expandable and expanded alkenyl aromatic polymer particles having the ability to use a decreased amount of blowing agent to produce an expanded alkenyl aromatic polymer particle of an equivalent bulk density or the same amount of blowing agent to produce an expanded alkenyl aromatic polymer particle having a decreased bulk density by including a density modifier in the expandable alkenyl aromatic polymer particle in an amount of about 0.005 to 0.5 weight percent by weight of the total mixture. Also included as part of the invention are methods of making the expandable and expanded alkenyl aromatic polymer particles wherein the expandable and expanded alkenyl aromatic polymer particles have a density modifier included in an amount of about 0.005 percent to about 0.5 weight percent by weight of the total mixture.

Description

IMPROVED EXPANDABLE AND EXPANDED ALKENYL AROMATIC POLYMER PARTICLES AND METHODS OF MAKING THE SAME
This, invention relates to improved expandable and expanded alkenyl aromatic polymer particles and methods for preparing these expandable and expanded particles.
Alkenyl aromatic polymer particles or beads, which are expandable or expanded, are known to be highly desirable for a number of uses. One highly desirable use is protection in packaging articles for shipping. Another use for the expandable alkenyl aromatic polymer particles is as molding material.
Although such expanded alkenyl aromatic polymer particles are highly desirable, they suffer from a substantial and significant problem of the high cost of shipping in the expanded state due to their very low bulk density. It is therefore generally desirable to ship a product having a maximum bulk density, as an expandable alkenyl aromatic polymer particle, and to subsequently expand the particle at or near the point of use into the desired form such as expanded alkenyl aromatic polymer packaging particles or expanded and molded alkenyl aromatic polymer foamed objects.
It is also advantageous when such expandable alkenyl aromatic polymer particles are expanded into plastic foam to achieve as low a bulk density as possible. It is also desirable when expanding the expandable alkenyl aromatic polymer particle to obtain the lowest bulk density in as short a time as possible, 0
It is even 'more desirable to decrease the amount of blowing agent used to prepare the expandable and expanded alkenyl aromatic polymer particles, especially if the blowing agent is a blowing agent which 5 is believed to cause damage to the earth's atmospheric laye .
The present invention provides expandable particles comprising an alkenyl aromatic polymer, a 0 volatile fluid blowing agent and a density modifier in an amount from 0.005 percent to 0.5 percent by weight of the total mixture. The present invention provides also expanded particles comprising an alkenyl aromatic polymer and a density modifier in an amount from 0.005 5 percent to 0.5 percent by weight of the total mixture.
Also contemplated are' methods for making the expanded and expandable particles by preparing a heat-plastified mixture- of an alkenyl aromatic polymer, 0 a volatile fluid blowing agent", and a density modifier in an amount from 0.005 percent to 0.5 percent by weight of the total mixture and extruding the mixture to form expandable and expanded alkenyl aromatic polymer ,.- particles. Still further contemplated as part of the present invention are methods for reducing the density in expanded alkenyl aromatic polymer particles while using a constant amount of a volatile fluid blowing agent and for reducing the amount of a volatile fluid blowing agent needed to produce expanded alkenyl aromatic polymer particles while maintaining a constant density. Both methods are accomplished by incorporating a density modifier into the expanded alkenyl aromatic
10 polymer particles prior to expansion, with the alkenyl aromatic polymer being a polymer or copolymer having in chemically combined form at least 50 percent by weight styrene.
15 The expandable particles of the present invention are thermoplastic resinous materials containing a density modifier and a blowing agent. The expanded particles of the present invention are the
20 thermoplastic resinous materials containing a density modifier.
The present invention provides expandable and expanded alkenyl aromatic polymer particles with the e- term alkenyl aromatic polymer including polymers or copolymers having in chemically combined form at least 50 percent by weight of at least one alkenyl aromatic compound having the general formula
R
30 1
Ar-C=CH-
wherein Ar represents an aromatic hydrocarbon radical or an aromatic halohydrocarbon radical of the benzene _,,- series and R is hydrogen or the methyl radical.
Examples of such alkenyl aromatic resins are the solid homopolymers of styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ar-ethylstyrene, ar-vinylxylene, ar-chlorostyrene, or ar-bromostyrene; and the solid copolymers of two or more of such alkenyl aromatic compounds with minor amounts of other readily polymerizable olefinic compounds such as divinylbenzene, methylmethacrylate or acrylonitrile.
Preferably, the alkenyl aromatic polymer is polystyrene having an weight-average molecular weight (Mw) of 100,000 to 300,000.
The volatile fluid foaming agents can be gases such as carbon dioxide, a saturated aliphatic hydrocarbon such as butane, isobutane, pentane, isopentane, neopentane, hexane, heptane or mixtures of one or more aliphatic hydrocarbons having a molecular weight of at least 65 and a boiling point not higher than 95° centigrade (C) at 760 millimeters absolute pressure. Other suitable fluid foaming agents are those halogenated hydrocarbons generally known in the art. The volatile fluid foaming agent usually is employed in amounts corresponding to from 5 to 15 percent of the weight of the total formulation. After expansion the volatile fluid blowing agent may .or may not be retained in the expanded alkenyl aromatic polymer particle.
It is well known to extrude foamable alkenyl aromatic polymer particles by cooling the viscous melt of the alkenyl aromatic polymer and the blowing agent below the blowing temperature under pressure and subsequently passing a strand into atmospheric pressure and rapidly cooling the strand into a solid or non-heat plastified state. It is also possible to extrude and expand these alkenyl aromatic polymer particles directly upon exiting a die.
It is also possible to include in the alkenyl aromatic polymer/blowing agent mixture other additives which are known in the art such as fire retardants, stabilizers, fillers, anti-static agents and colorants. Also those materials known as "cell-size control additives" may be incorporated into the alkenyl aromatic polymer/blowing agent mixture for use in the production of uniform extruded foam prior to extrusion from a die.
While the expandable alkenyl aromatic polymer particles produced may be in any form, particularly preferred are those forms suitable for packaging or dunnage purposes and those forms which after expansion are suitable for molding purposes.
The present invention requires the inclusion of a density modifier in a heat-plastified alkenyl aromatic polymer/blowing agent mixture in an amount of from 0.005 weight percent to 0.5 weight percent by total mixture weight. The preferred ranges are from 0.01 to 0.3 weight percent by total mixture weight.
The "density modifier" is defined as a compound providing thermal stability for the alkenyl aromatic polymer at extrusion and expansion conditions and which is also a liquid plasticizer at expansion conditions. Such density modifiers include, but are not limited to, octadecyl 3»5-di-tert-butyl-4-hydroxyhydrocinnamate and ethylene bis(oxyethylene) bis(3-tert-butyl-4-hydroxy-5- methylhydrocinnamate) .
The following example and comparative example illustrate the present invention. The percentages are weight percent based on total mixture weight. CFC-11 is trichlorofluoromethane.
Comparative Example
Polystyrene Balance
(Mw about 200,000)
Blowing Agent 10.1-10.3 percent
(80 percent/20 percent CFC-11/Pentane - weight percents based on weight of blowing agent mixture)
Example
Polystyrene Balance
(Mw about 200,000)
Blowing Agent 8.8 percent (80 percent/20 percent CFC-11 /Pentane - weight percents based on weight of blowing agent mixture)
Density Modifier 0.2 percent (octadecyl
3,5-di-tert-butyl-4 -hydroxyhydrocinnamate)
The Example formulation differs only in the octadecyl 3»5-di-tert-butyl-4-hydroxyhydrocinnamate being present in an amount of about 0.2 percent and the reduced amount of about 8.8 percent blowing agent, instead of 10.1 percent to 10.3 percent blowing agent as is in the Comparative Example. After producing these expandable polystyrene particles these samples are then expanded in an atmospheric steam chamber for controlled periods of time at a temperature generally ranging from about 85°C to about 105°C, preferably about 100°C.
Typically the expansion scheme will consist of a 3 minute exposure followed by a 24 hour aging time at room conditions, then a second 3 minute exposure followed by a second 24 hour aging time, and then a third 1-1/2 minute exposure and a third 24 hour aging time. After this third aging period the bulk densities of the expanded polystyrene particles are measured. This expansion scheme is followed to produce expanded polystyrene particles. The Comparative Example expanded polystyrene particle bulk densities range from 0.28 to 0.33 pounds per cubic foot (4.5-5.3 kg/m^). The Example expanded polystyrene particles of the present invention have a bulk density of about 0.26 pounds per cubic foot (4.2 g/π-3).
The ability to maintain an equivalent density with a decreased amount of blowing agent is found to be a result solely from the inclusion of the octadecyl 3»5- di-tert-butyl-4-hydroxyhydrooinnamate in an amount of about 0.2 percent, as stated in the Example into the expandable polystyrene particle formulation. Generally a blowing agent decrease will produce an expanded polystyrene particle of higher density than when less blowing agent is included, not a lower density.

Claims

WHAT IS CLAIMED IS:
1. An expandable particle comprising:
a) an alkenyl aromatic polymer;
b) a volatile fluid blowing agent; and
c) a density modifier in an amount from 0.005 percent to 0.5 percent by weight of the total mixture.
2. Expandable particle of Claim 1 wherein the density modifier is present in an amount from 0.01 percent to 0.
3 percent by weight of the total mixture. 5 3. Expandable particle of Claim 1 or 2, wherein the density modifier is ethylene bis(oxyethylene) bis(3-tert-butyl-4-hydroxy-5- methylhydrocinnamate) or octadecyl 3»5-di-tert-butyl-4- Q hydroxyhydrocinnamate.
4. Expandable particle of any one of Claims 1 to 3» wherein the alkenyl aromatic polymer is polystyrene. 5
5. An expanded particle produced by the expansion of any one of Claims 1 to 4.
6. A method for making the expandable c particle of any one of Claims 1 to 4 comprising:
a) preparing a heat-plastified mixture of:
1) an alkenyl aromatic polymer;
10
2) a volatile fluid blowing agent; and
3) a density modifier; and
..j- b) extruding the mixture to form expandable alkenyl aromatic polymer particles.
7. A method for making the expanded particle of Claim 5 comprising:
20 a) preparing a heat-plastified mixture of:
1) an alkenyl aromatic polymer;
2i- 2) a volatile fluid blowing agent; and
3) a density modifier; and
b) extruding the mixture to form expanded
30 alkenyl aromatic polymer particles.
8. A method for reducing the density in expanded alkenyl aromatic polymer particles while using a constant amount of a volatile fluid blowing agent,
35 comprising: incorporating a density modifier into the expanded alkenyl aromatic polymer particles prior to expansion, with the alkenyl aromatic polymer being a polymer or copolymer having in chemically combined form at least 50 percent by weight styrene.
9. A method for reducing the amount of a volatile fluid blowing agent needed to produce expanded alkenyl aromatic polymer particles while maintaining a constant density comprising:
incorporating a density modifier into the expanded alkenyl aromatic polymer particles prior to expansion, with the thermoplastic resinous material being a polymer or copolymer having in chemically combined form at least 50 percent by weight styrene.
PCT/US1989/002576 1988-08-22 1989-06-13 Improved expandable and expanded alkenyl aromatic polymer particles and methods of making the same WO1990002151A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
BR898907615A BR8907615A (en) 1988-08-22 1989-06-13 EXPANSIBLE AND EXPANDED PERFECTED ALKENILLA AROMATIC POLYMER PARTICLES AND MANUFACTURING PROCESSES OF THE SAME

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US243,986 1981-03-16
US24398688A 1988-08-22 1988-08-22

Publications (1)

Publication Number Publication Date
WO1990002151A1 true WO1990002151A1 (en) 1990-03-08

Family

ID=22920932

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1989/002576 WO1990002151A1 (en) 1988-08-22 1989-06-13 Improved expandable and expanded alkenyl aromatic polymer particles and methods of making the same

Country Status (3)

Country Link
EP (1) EP0430998A4 (en)
JP (1) JPH04500225A (en)
WO (1) WO1990002151A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1352022A1 (en) * 2000-12-04 2003-10-15 Nova Chemicals Inc. Foamed cellular particles of an expandable polymer composition

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3505253A (en) * 1967-09-14 1970-04-07 Arnold B Finestone Expandable alkenyl aromatic polymers containing incorporated expandable alkenyl aromatic polymers and polysiloxane
US4448901A (en) * 1982-05-13 1984-05-15 Kanegafuchi Kagaku Kogyo Kabushiki Kaisha Expanded particles of polyolefin resin and process for producing same
US4464484A (en) * 1982-12-20 1984-08-07 Japan Styrene Paper Corporation Process for producing prefoamed polymer particles

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB886811A (en) * 1957-11-29 1962-01-10 Dow Chemical Co Method of making a latent-foaming polymeric composition
AU8224682A (en) * 1981-04-30 1982-11-04 Mobil Oil Corp. Hindered phenol as stabilizer for styrene

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3505253A (en) * 1967-09-14 1970-04-07 Arnold B Finestone Expandable alkenyl aromatic polymers containing incorporated expandable alkenyl aromatic polymers and polysiloxane
US4448901A (en) * 1982-05-13 1984-05-15 Kanegafuchi Kagaku Kogyo Kabushiki Kaisha Expanded particles of polyolefin resin and process for producing same
US4464484A (en) * 1982-12-20 1984-08-07 Japan Styrene Paper Corporation Process for producing prefoamed polymer particles

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0430998A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1352022A1 (en) * 2000-12-04 2003-10-15 Nova Chemicals Inc. Foamed cellular particles of an expandable polymer composition
EP1352022A4 (en) * 2000-12-04 2004-03-24 Nova Chem Inc Foamed cellular particles of an expandable polymer composition

Also Published As

Publication number Publication date
EP0430998A4 (en) 1991-10-16
EP0430998A1 (en) 1991-06-12
JPH04500225A (en) 1992-01-16

Similar Documents

Publication Publication Date Title
US5348984A (en) Expandable composition and process for extruded thermoplastic foams
US4559367A (en) Combination blowing agent and filler for thermoplastic foams
US5006566A (en) Preparation of foams having a high compressive strength
US5801208A (en) Blowing agent, expandable composition, and process for extruded thermoplastic foams
US3420786A (en) Self-extinguishing styrene polymer composition containing a bromine compound and 2,3 - dimethyl - 2,3 - diphenyl butane
US6030696A (en) Extruded polyolefin foam in thicker grades and plank and process therefor
US3457204A (en) Self-extinguishing thermoplastic compositions
US5422378A (en) Foamable styrenic polymer gel and resulting foam
US3188295A (en) Method of foaming a thermoplastic organic polymer containing a nucleating agent and an organic bromide
US3441524A (en) Self-extinguishing thermoplastic compositions
AU564115B2 (en) Method for the preparation of styrene polymer foam and foam prepared thereby
JPH0739502B2 (en) Expandable polyvinyl (vinylidene) aromatic particles and method for producing the same
US4839396A (en) Expandable and expanded alkenyl aromatic polymer particles and methods of making the same
US3975327A (en) Particulate, expandable self-extinguishing styrene polymers showing good processability
EP0238504B1 (en) Method for steam expanding a polymeric composition
US6342540B1 (en) Method for producing water expandable styrene polymers
US4912140A (en) Expandable and expanded alkenyl aromatic polymer particles
US3472799A (en) Self-extinguishing thermoplastic compositions
US4866098A (en) Expandable and expanded alkenyl aromatic polymer particles and methods of making the same
WO1990002151A1 (en) Improved expandable and expanded alkenyl aromatic polymer particles and methods of making the same
US4169193A (en) Process for preparing expandible poly-styrene particles useful for obtaining molded bodies having a cellular structure
JPH07278365A (en) Low-density polyolefin foam, foamable polyolefin compositionand their production
US5071606A (en) Plasticizers for expandable styrene-acrylonitrile resin
US20040209967A1 (en) Flame retarded styrenic polymer foams
US4158086A (en) Flameproof thermoplastic molding material

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1989909362

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1989909362

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1989909362

Country of ref document: EP