CA2016587A1 - Expandable styrene polymers - Google Patents
Expandable styrene polymersInfo
- Publication number
- CA2016587A1 CA2016587A1 CA002016587A CA2016587A CA2016587A1 CA 2016587 A1 CA2016587 A1 CA 2016587A1 CA 002016587 A CA002016587 A CA 002016587A CA 2016587 A CA2016587 A CA 2016587A CA 2016587 A1 CA2016587 A1 CA 2016587A1
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- Canada
- Prior art keywords
- weight
- styrene
- component
- expandable
- styrene polymer
- Prior art date
- Legal status (The legal status 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 status listed.)
- Abandoned
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Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F291/00—Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
-
- 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
- C08J9/16—Making expandable particles
- C08J9/20—Making expandable particles by suspension polymerisation in the presence of the blowing agent
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F291/00—Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
- C08F291/02—Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00 on to elastomers
-
- 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
- C08J9/16—Making expandable particles
- C08J9/18—Making expandable particles by impregnating polymer particles with the blowing agent
-
- 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
- C08J2351/00—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
- C08J2351/04—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers grafted on to rubbers
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Polyurethanes Or Polyureas (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
- 12 - O.Z. 0050/40807 Abstract of the Disclosure: Expandable styrene polymers of a) from 50 to 98% by weight of polystyrene and b) from 2 to 50% by weight of a styrene-soluble elastomer, which may contain from l to 15% by weight, based on the sum of a) and b), of a low boiling blowing agent and, if required, conventional additives, are expanded to give foams which have a density of from 0.01 to 0.1 g/cm3 and greater resilience. They can be prepared by suspension polymerization of a solution of the elastomer in styrene, a blowing agent being added.
Description
201fi~
O.Z. 0050/40807 Ex~andable styrene polymers The present invention relates to novel expandable styrene polymer~ which are suitable for the preparation of resilient foams.
Foams ba~ed on styrene polymers have become very important industrially as heat insulation and packaging material~. They are produced industrially on a large scale by first preparing expandable styrene polymers by suspension polymerization of styrene in the presence of a blowing agent, expanding the said polymers by heating to give foam particles and then welding the latter in molds to form moldings.
Polystyrene foams are rigid foams. It i~ an object of the present invention to increase the resil-ience of the polystyrene foams and to provide a raw material for the preparation of resilient polystyrene foams.
We have found, surprisingly, that these ob~ects are achieved by admixing styrene-soluble elastomer~.
The present invention thus relates to expandable styrene polymers containing a) from 50 to 98% by weight of polystyrene and/or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50~ by weight of a styrene-soluble elastomer, c) from 1 to 15% by weight, based on the sum of a) and b) of a low bsiling blowing agent and, if re~uired, d) conventional additives in effective amounts.
The present invention furthermore relates to foams having a density of from 0.01 to 0.1 g/cm3 and con-taining a) from 50 to 98% by weight of polystyrene or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50% by weight of a styrene-soluble ela~to-mer and, if required, 2~
- 2 - O.Z. 0050/40807 c) conventional additive~ in effective amounts.
The novel products contain, a~ main components a), from 50 to 98, preferably from 50 to 90, in par-ticular from 70 to 85, % by weight of polystyrene and/or a styrene copolymer containing not less than 50, prefer-ably not les~ than 80, ~ by weight of polymerized sty-rene. Example~ of suitable comonomers are ~-methyl-styrene, styrene~ halogenated in the nucleus, styrenes alkylated in the nucleus, acrylonitrile, esters of acrylic or methacrylic acid with alcohols of 1 to 8 carbon atom~, N-vinylcarbazole, maleic acid and maleic anhydride. Advantageously, the poly~tyrene contains a small amount of a crosslinking agent as polymerized units, ie. a compound having more than one, preferably two, double bonds, such as divinylbenzene, butadiene or butanediol diacrylate. The crosslinking agent i8 used in general in amounts of from 0.005 to 0.05 mol %, based on styrene.
To achieve particularly high expandability, it is advantageous for the styrene polymer to have a mean molecular weight M~ (weight average) of from 100,000 to 200,000, in particular from 130,000 to 180,000, measured by the GPC method. The foam has improved processing properties when the high molecular weight slope of the molecular weight distribution curve measured by the GPC
method is 80 steep that the difference between the mean value~ (Mz+~-Mz) i5 less than lS0,000. The GPC method is described in G. Glockler, Polymercharakterisierung, Chromatographische Methoden Volume 17, H~thig-Verlag, Heidelberg 1982. The stated mean values are described in H.G. Elias, Makromolekule, H~thig-Verlag, Heidelberg 1971, page3 52-64.
Styrene polymers which have the abovementioned mean molecular weight~ can be obtained if regulator~ are present during the polymerization. Advantageously from 0.01 to l.S, preferably from 0.01 to 0.5, % by weight of a bromine-free organic compound having a chain transfer 201~ 7 - 3 - O.Z. 0050/40807 constant K of from 0.1 to S0 are used a~ the regulator.
~dvantageously, the regulator is added during the poly-merization only when a conversion of from 20 to 90~ has ,been reached, in order to achieve a steep high molecular weight slope of the molecular weight distribution curve.
Advantageous high expandability can also be achieved if component a) contains from 0.1 to 10~ advan-tageously from 0.5 to 10, % by weight of ~ styrene poly-mer having a mean molecular weight (weight average) of from S00 to S,000.
Further details of molecular weight regulation in the preparation of expandable styrene polymer~ are given in EP-B 106 129.
Styrene polymers which contain from 0.1 to 2, preferably from O.lS to 1.5, ~ by weight of polymerized acrylonitrile lead to foams which are ~ub~tantially free of shrinkage. A mixture of from 9S to 99.5% by weight of poly~tyrene and from O.S to 5% by weight of a styrene-soluble styrene/acrylonitrile copolymer al~o has these properties if the total content of acrylonitrile in the mixture is from 0.1 to 2, preferably from O.lS to 2, % by weight.
Styrene polymers which contain from 3 to 20, preferably from S to 15, ~ by weight of polymerized 2S acrylonitrile lead to foam~ having high resistance to oil. A mixture of from S0 to 8S% by weight of poly-~tyrene and lS to 50% by weight of a styrene-soluble s~yrene/acrylonitrile copolymer also has this advan-tageous property if the total content of acrylonitrile in the mixture is from 3 to 20, preferably from 5 to 15, % by weight. Such mixtures are prepared in a simple manner by di~solving the intended amount of the styrene/
acrylonitrLle copolymer in ~tyrene prior to the polymerization.
Styrene polymers which contain from 2 to 15, in particular from 3 to 12, % by weight of maleic acid or maleic anhydride as the comonomer lead to foams which 2~)165~7 - 4 - O.Z. 0050/40807 have high heat distortion re~istance. ~n advantageously used starting material is a mixture of poly~tyrene and a commercial styrene/maleic anhydride copolymer containing from 15 to 49% by weight of maleic anhydride, which mix-ture can readily be prepared by dissolution of the copolymer in styrene and sub~equent polymerization.
~he products contain, as further component b), a styrene-soluble elastomer in an amount of from 2 to 50, preferably from S to 40, in particular from 10 to 30, %
by weight. The elastomer is generally essentially non-crosslinked, ie. the degree of crosslinking may be 90 low that the solubility in styrene is not adversely affected as a re~ult. Ela~tomers whose gel content doe3 not exceed 10% by weight are ~till considered as essentially noncrosslinked and àre suitable as an additive. The ela~tomer generally has a glass transition temperature of less than 0C, preferably le s than -10C, in particular less than -20C. For example, styrene-soluble ethylene/
propylene rubbers, which may contain small amounts of a diene as polymerized units, and polyisobutylene, styrene-soluble vinyl ether rubbers, acrylate rubbers, in par-ticular those ba~ed on C2-C8-alkyl acrylates, styrene-soluble silicone rubbers and styrene-soluble polyurethane rubbers are suitable.
The expandable ~tyrene polymers contain from 1 to 15, preferably from 2 to 10, in particular from 3 to 8, % by weight of a low boiling blowing agent as component c)~ homogeneously distributed. The blowing agents should not dissolve the polystyrene but should be soluble in poly~tyrene. The boiling point should be below the ~oftening point of the polystyrene. Examples of suitable blowing agents are propane, butane, pentane, hexane, cyclopentane, cyclohexane, octane, dichlorodifluoro-methane, trifluorochloromethane and l,l,l-difluorochloro-ethane. Pentane i~ preferably used.
The expandable styrene polymers may furthermore contain effective amounts of conventional additives, ~uch ;~0~5~
- S - O.Z. 0050/40807 as dyes, fillers, stabilizer3, flameproofing agents, ~ynergistic agents, nucleatlng agents, lubricating agents, antistatic agents, substances which have an anti-adhesive effect during expansion and agents for reducing 5the demolding time in final expan~ion.
Other suitable additives are poly-(2,6-dimethyl)-1,4-phenylene ether and poly-1,4-phenylene sulfide. In amounts of from 1 to 20~ by weight, based on component a)/ these additives increase the heat distortion re~is-10tance of the foam.
The expandable styrene polymers are generally present in the form of particle~, ie. in bead form, granular form or in the form of fragments, and advan-tageously have a mean diameter of from 0.1 to 6 mm, in 15particular from 0.4 to 3 mm.
The preparation can be carried out, for example, by mixing the components in the melt in an extruder, the extrudate being cooled so rapidly that no expansion takes place, and then being comminuted.
20The preparation is advantageously carried out by suspension polymerization in a conventional manner. For this purpoqe, the elastomer and any additives are dis-solved in styrene, and this solution i9 polymerized in aqueous su~pension. A regulator or a small amount, for 25example from 0.005 to 0.05 mol ~, based on styrene, of a cro~slinking agent is advantageously added during the polymerization. The blowing agent may be initially taken in the polymerization or may be added in the course of the polymerization. It may also be added to the batch 30after polymerization i~ complete.
The re~ulting bead-like expandable ~tyrene poly-mers are then i~olated from the aqueous phase, washed and dried.
For the production of foam~, the expandable 35styrene polymers are expanded in a known manner by heat-ing above their softening point, for example with hot air or preferably with steam. After cooling and, if neces-20~ 7 - 6 - O.Z. 0050/40807 sary, intermediate storage, the resulting foam particle~
can be further expanded by heating again. They can then be welded in a known manner, in molds which close without a gas-tight seal, to give moldings.
5The foams obtained have a den~ity of about 0.01-0.1 g/cm3. Because of their resilience, they are used in particular for shock-absorbing packaging, as core mater-ial for automobile bumpers, for interior trim in auto-mobiles, as upholstery material and as heat and sound 10insulation material.
In the Examples which follow, parts are by weight.
In a pressure-resistant stirred kettle, a mixture 15of 200 parts of water, 0.1 part of sodium pyrophosphate, 100 parts of a ~olution of 9 parts of polyi~obutylene having an intrinsic viscosity of 28 [cm3/g] and a glass transition temperature of -64C (Oppanol B10 from BASF
AG) in 91 parts of styrene, 7.5 parts of pentane, 0.15 20part of tert-butyl peroxide, 0.45 part of benzoyl perox-ide and 4 parts of a 10% strength aqueous solution of polyvinylpyrrolidone was heated to 90C while stirring, kept at this temperature for 5 hours and then heated at 100C for 2 hours and at 120C for a further 2 hours.
25After cooling, the resulting bead polymer having a mean particle diameter of about 1 mm was isolated from the aqueous phase, washed and dried.
The resulting expandable styrene polymer was sub~ected to preexpansion in a commercial stirred 30Rauscher-type preexpander, using a stream of steam, to a bulk den~ity of about 30 g/l. After storage for 24 hours, the foam particles were welded in a ~auscher-type block mold by treatment with steam and under a pressure of 1.8 bar to give a block having a den~ity of about 30 35g/l.
The re3ilience was tested by measuring the ten-~ile strength (DIN 53,430) and the modulus of elasticity ~O~L65~37 _ 7 _ O.z. 0050/40807 (DIN 53,426) using samples of the foam block. The results are summarized in Table 1.
The procedure described in Example l wa~ fol-lowed, except that a solution of 11 parts of polyiso-butylene in 89 parts of styrene was used.
The procedure described in Example 1 was fol-lowed, except that a solution of 21.5 parts of polyiso-0 butylene in 78.5 parts of styrene was used.EXAMPLES 4 AND 5 The procedure described in Example 1 was fol-lowed, except that a solution of 11 (or 21.5) parts of polyisobutylene having an intrinsic viscosity of 38.5 (Oppanol B12 from BASF AG) in 89 (or 78.5) parts of styrene was used.
EXANPLES 6 ~0 8 The procedure described in Examples 1 to 3 was followed, except that 0.01 part of divinylbenzene was present during the polymerization.
EXAMPLE 9 (CONPARISON) The procedure described in Example 1 was fol-lowed, except that 100 parts of styrene were polymerized in the absence of an elastomer.
X016~37 - 8 - 0.2. 0050/40807 E'xam-Polyi obutylene Tensile Modulus of E~le% by wt. Intrinsic strength elasticity viscosity DIN 53,430 DIN 53,426 S r cm3/al ~kp/cm21 r ka/cm2 ]
1 9 28 4.6 210 2 11 28 5.5 224 3 21.5 28 6.4 241 4 11 38.5 6.3 239 21.5 38.5 6.9 249 6 9 28 S.2 220 7 11 28 5.7 228 8 21.S 28 6.7 250 9 - - 3.6 lSl 15 (Comparison) .
O.Z. 0050/40807 Ex~andable styrene polymers The present invention relates to novel expandable styrene polymer~ which are suitable for the preparation of resilient foams.
Foams ba~ed on styrene polymers have become very important industrially as heat insulation and packaging material~. They are produced industrially on a large scale by first preparing expandable styrene polymers by suspension polymerization of styrene in the presence of a blowing agent, expanding the said polymers by heating to give foam particles and then welding the latter in molds to form moldings.
Polystyrene foams are rigid foams. It i~ an object of the present invention to increase the resil-ience of the polystyrene foams and to provide a raw material for the preparation of resilient polystyrene foams.
We have found, surprisingly, that these ob~ects are achieved by admixing styrene-soluble elastomer~.
The present invention thus relates to expandable styrene polymers containing a) from 50 to 98% by weight of polystyrene and/or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50~ by weight of a styrene-soluble elastomer, c) from 1 to 15% by weight, based on the sum of a) and b) of a low bsiling blowing agent and, if re~uired, d) conventional additives in effective amounts.
The present invention furthermore relates to foams having a density of from 0.01 to 0.1 g/cm3 and con-taining a) from 50 to 98% by weight of polystyrene or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50% by weight of a styrene-soluble ela~to-mer and, if required, 2~
- 2 - O.Z. 0050/40807 c) conventional additive~ in effective amounts.
The novel products contain, a~ main components a), from 50 to 98, preferably from 50 to 90, in par-ticular from 70 to 85, % by weight of polystyrene and/or a styrene copolymer containing not less than 50, prefer-ably not les~ than 80, ~ by weight of polymerized sty-rene. Example~ of suitable comonomers are ~-methyl-styrene, styrene~ halogenated in the nucleus, styrenes alkylated in the nucleus, acrylonitrile, esters of acrylic or methacrylic acid with alcohols of 1 to 8 carbon atom~, N-vinylcarbazole, maleic acid and maleic anhydride. Advantageously, the poly~tyrene contains a small amount of a crosslinking agent as polymerized units, ie. a compound having more than one, preferably two, double bonds, such as divinylbenzene, butadiene or butanediol diacrylate. The crosslinking agent i8 used in general in amounts of from 0.005 to 0.05 mol %, based on styrene.
To achieve particularly high expandability, it is advantageous for the styrene polymer to have a mean molecular weight M~ (weight average) of from 100,000 to 200,000, in particular from 130,000 to 180,000, measured by the GPC method. The foam has improved processing properties when the high molecular weight slope of the molecular weight distribution curve measured by the GPC
method is 80 steep that the difference between the mean value~ (Mz+~-Mz) i5 less than lS0,000. The GPC method is described in G. Glockler, Polymercharakterisierung, Chromatographische Methoden Volume 17, H~thig-Verlag, Heidelberg 1982. The stated mean values are described in H.G. Elias, Makromolekule, H~thig-Verlag, Heidelberg 1971, page3 52-64.
Styrene polymers which have the abovementioned mean molecular weight~ can be obtained if regulator~ are present during the polymerization. Advantageously from 0.01 to l.S, preferably from 0.01 to 0.5, % by weight of a bromine-free organic compound having a chain transfer 201~ 7 - 3 - O.Z. 0050/40807 constant K of from 0.1 to S0 are used a~ the regulator.
~dvantageously, the regulator is added during the poly-merization only when a conversion of from 20 to 90~ has ,been reached, in order to achieve a steep high molecular weight slope of the molecular weight distribution curve.
Advantageous high expandability can also be achieved if component a) contains from 0.1 to 10~ advan-tageously from 0.5 to 10, % by weight of ~ styrene poly-mer having a mean molecular weight (weight average) of from S00 to S,000.
Further details of molecular weight regulation in the preparation of expandable styrene polymer~ are given in EP-B 106 129.
Styrene polymers which contain from 0.1 to 2, preferably from O.lS to 1.5, ~ by weight of polymerized acrylonitrile lead to foams which are ~ub~tantially free of shrinkage. A mixture of from 9S to 99.5% by weight of poly~tyrene and from O.S to 5% by weight of a styrene-soluble styrene/acrylonitrile copolymer al~o has these properties if the total content of acrylonitrile in the mixture is from 0.1 to 2, preferably from O.lS to 2, % by weight.
Styrene polymers which contain from 3 to 20, preferably from S to 15, ~ by weight of polymerized 2S acrylonitrile lead to foam~ having high resistance to oil. A mixture of from S0 to 8S% by weight of poly-~tyrene and lS to 50% by weight of a styrene-soluble s~yrene/acrylonitrile copolymer also has this advan-tageous property if the total content of acrylonitrile in the mixture is from 3 to 20, preferably from 5 to 15, % by weight. Such mixtures are prepared in a simple manner by di~solving the intended amount of the styrene/
acrylonitrLle copolymer in ~tyrene prior to the polymerization.
Styrene polymers which contain from 2 to 15, in particular from 3 to 12, % by weight of maleic acid or maleic anhydride as the comonomer lead to foams which 2~)165~7 - 4 - O.Z. 0050/40807 have high heat distortion re~istance. ~n advantageously used starting material is a mixture of poly~tyrene and a commercial styrene/maleic anhydride copolymer containing from 15 to 49% by weight of maleic anhydride, which mix-ture can readily be prepared by dissolution of the copolymer in styrene and sub~equent polymerization.
~he products contain, as further component b), a styrene-soluble elastomer in an amount of from 2 to 50, preferably from S to 40, in particular from 10 to 30, %
by weight. The elastomer is generally essentially non-crosslinked, ie. the degree of crosslinking may be 90 low that the solubility in styrene is not adversely affected as a re~ult. Ela~tomers whose gel content doe3 not exceed 10% by weight are ~till considered as essentially noncrosslinked and àre suitable as an additive. The ela~tomer generally has a glass transition temperature of less than 0C, preferably le s than -10C, in particular less than -20C. For example, styrene-soluble ethylene/
propylene rubbers, which may contain small amounts of a diene as polymerized units, and polyisobutylene, styrene-soluble vinyl ether rubbers, acrylate rubbers, in par-ticular those ba~ed on C2-C8-alkyl acrylates, styrene-soluble silicone rubbers and styrene-soluble polyurethane rubbers are suitable.
The expandable ~tyrene polymers contain from 1 to 15, preferably from 2 to 10, in particular from 3 to 8, % by weight of a low boiling blowing agent as component c)~ homogeneously distributed. The blowing agents should not dissolve the polystyrene but should be soluble in poly~tyrene. The boiling point should be below the ~oftening point of the polystyrene. Examples of suitable blowing agents are propane, butane, pentane, hexane, cyclopentane, cyclohexane, octane, dichlorodifluoro-methane, trifluorochloromethane and l,l,l-difluorochloro-ethane. Pentane i~ preferably used.
The expandable styrene polymers may furthermore contain effective amounts of conventional additives, ~uch ;~0~5~
- S - O.Z. 0050/40807 as dyes, fillers, stabilizer3, flameproofing agents, ~ynergistic agents, nucleatlng agents, lubricating agents, antistatic agents, substances which have an anti-adhesive effect during expansion and agents for reducing 5the demolding time in final expan~ion.
Other suitable additives are poly-(2,6-dimethyl)-1,4-phenylene ether and poly-1,4-phenylene sulfide. In amounts of from 1 to 20~ by weight, based on component a)/ these additives increase the heat distortion re~is-10tance of the foam.
The expandable styrene polymers are generally present in the form of particle~, ie. in bead form, granular form or in the form of fragments, and advan-tageously have a mean diameter of from 0.1 to 6 mm, in 15particular from 0.4 to 3 mm.
The preparation can be carried out, for example, by mixing the components in the melt in an extruder, the extrudate being cooled so rapidly that no expansion takes place, and then being comminuted.
20The preparation is advantageously carried out by suspension polymerization in a conventional manner. For this purpoqe, the elastomer and any additives are dis-solved in styrene, and this solution i9 polymerized in aqueous su~pension. A regulator or a small amount, for 25example from 0.005 to 0.05 mol ~, based on styrene, of a cro~slinking agent is advantageously added during the polymerization. The blowing agent may be initially taken in the polymerization or may be added in the course of the polymerization. It may also be added to the batch 30after polymerization i~ complete.
The re~ulting bead-like expandable ~tyrene poly-mers are then i~olated from the aqueous phase, washed and dried.
For the production of foam~, the expandable 35styrene polymers are expanded in a known manner by heat-ing above their softening point, for example with hot air or preferably with steam. After cooling and, if neces-20~ 7 - 6 - O.Z. 0050/40807 sary, intermediate storage, the resulting foam particle~
can be further expanded by heating again. They can then be welded in a known manner, in molds which close without a gas-tight seal, to give moldings.
5The foams obtained have a den~ity of about 0.01-0.1 g/cm3. Because of their resilience, they are used in particular for shock-absorbing packaging, as core mater-ial for automobile bumpers, for interior trim in auto-mobiles, as upholstery material and as heat and sound 10insulation material.
In the Examples which follow, parts are by weight.
In a pressure-resistant stirred kettle, a mixture 15of 200 parts of water, 0.1 part of sodium pyrophosphate, 100 parts of a ~olution of 9 parts of polyi~obutylene having an intrinsic viscosity of 28 [cm3/g] and a glass transition temperature of -64C (Oppanol B10 from BASF
AG) in 91 parts of styrene, 7.5 parts of pentane, 0.15 20part of tert-butyl peroxide, 0.45 part of benzoyl perox-ide and 4 parts of a 10% strength aqueous solution of polyvinylpyrrolidone was heated to 90C while stirring, kept at this temperature for 5 hours and then heated at 100C for 2 hours and at 120C for a further 2 hours.
25After cooling, the resulting bead polymer having a mean particle diameter of about 1 mm was isolated from the aqueous phase, washed and dried.
The resulting expandable styrene polymer was sub~ected to preexpansion in a commercial stirred 30Rauscher-type preexpander, using a stream of steam, to a bulk den~ity of about 30 g/l. After storage for 24 hours, the foam particles were welded in a ~auscher-type block mold by treatment with steam and under a pressure of 1.8 bar to give a block having a den~ity of about 30 35g/l.
The re3ilience was tested by measuring the ten-~ile strength (DIN 53,430) and the modulus of elasticity ~O~L65~37 _ 7 _ O.z. 0050/40807 (DIN 53,426) using samples of the foam block. The results are summarized in Table 1.
The procedure described in Example l wa~ fol-lowed, except that a solution of 11 parts of polyiso-butylene in 89 parts of styrene was used.
The procedure described in Example 1 was fol-lowed, except that a solution of 21.5 parts of polyiso-0 butylene in 78.5 parts of styrene was used.EXAMPLES 4 AND 5 The procedure described in Example 1 was fol-lowed, except that a solution of 11 (or 21.5) parts of polyisobutylene having an intrinsic viscosity of 38.5 (Oppanol B12 from BASF AG) in 89 (or 78.5) parts of styrene was used.
EXANPLES 6 ~0 8 The procedure described in Examples 1 to 3 was followed, except that 0.01 part of divinylbenzene was present during the polymerization.
EXAMPLE 9 (CONPARISON) The procedure described in Example 1 was fol-lowed, except that 100 parts of styrene were polymerized in the absence of an elastomer.
X016~37 - 8 - 0.2. 0050/40807 E'xam-Polyi obutylene Tensile Modulus of E~le% by wt. Intrinsic strength elasticity viscosity DIN 53,430 DIN 53,426 S r cm3/al ~kp/cm21 r ka/cm2 ]
1 9 28 4.6 210 2 11 28 5.5 224 3 21.5 28 6.4 241 4 11 38.5 6.3 239 21.5 38.5 6.9 249 6 9 28 S.2 220 7 11 28 5.7 228 8 21.S 28 6.7 250 9 - - 3.6 lSl 15 (Comparison) .
Claims (14)
1. An expandable styrene polymer containing a) from 50 to 98% by weight of polystyrene and/or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50% by weight of a styrene-soluble elastomer, c) from 1 to 15% by weight, based on the sum of a) and b) of a low boiling blowing agent and, if required, d) conventional additives in effective amounts.
2. An expandable styrene polymer as claimed in claim 1, wherein component a) has been prepared in the presence of from 0.005 to 0.05 mol % of a crosslinking agent.
3. An expandable styrene polymer as claimed in claim 1, wherein component a) has a mean molecular weight Mw (weight average) of from 100,000 to 200,000, measured by the GPC method.
4. An expandable styrene polymer as claimed in claim 3, wherein the high molecular weight slope of the molecu-lar weight distribution curve of component a), measured by the GPC method, is so steep that the difference bet-ween the mean values (Mz+1-Mz) is less than 150,000.
5. An expandable styrene polymer as claimed in claim 1, wherein component a) contains from 0.1 to 10% by weight of styrene polymers having a mean molecular weight (weight average) of from 500 to 5,000.
6. An expandable styrene polymer as claimed in claim 1, wherein component a) has been prepared in the presence of from 0.01 to 1.5% by weight of a bromine-free organic compound having a chain transfer constant K of from 0.1 to 50.
7. An expandable styrene polymer as claimed in claim 1, wherein component b) is essentially noncrosslinked and has a glass transition temperature of less than 0°C.
8. An expandable styrene polymer as claimed in claim 1, wherein component b) is an ethylene/propylene rubber, polyisobutylene rubber, polyvinyl ether rubber, acrylate - 10 - O.Z. 0050/40807 rubber, silicone rubber or polyurethane elastomer.
9. An expandable styrene polymer as claimed in claim 1, wherein component a) is a styrene/acrylonitrile copolymer containing from 0.1 to 2% by weight of acrylo-nitrile or is a mixture of from 95 to 99.5% by weight of polystyrene and from 0.5 to 5% by weight of a styrene-soluble styrene/acrylonitrile copolymer having a total content of from 0.1 to 2% by weight of acrylonitrile in the mixture.
10. An expandable styrene polymer as claimed in claim 1, wherein component a) is a styrene/acrylonitrile copolymer containing from 3 to 20% by weight of acrylo-nitrile or is a mixture of from 50 to 85% by weight of polystyrene and from 15 to 50% by weight of a styrene-soluble styrene/acrylonitrile copolymer having a total content of from 3 to 20% by weight of acrylonitrile in the mixture.
11. An expandable styrene polymer as claimed in claim 1, wherein component a) is a mixture of polystyrene and a styrene/maleic acid or maleic anhydride copolymer having a total content of from 2 to 15% by weight of maleic acid or maleic anhydride.
12. A process for the preparation of an expandable styrene polymer as claimed in claim 1, wherein the elas-tomer is dissolved in styrene and polymerized in aqueous suspension, and the blowing agent is added during or after the polymerization.
13. A foam having a density of from 0.01 to 0.1 g/cm3 and containing a) from 50 to 98% by weight of polystyrene and/or of a styrene copolymer containing not less than 50% by weight of polymerized styrene, b) from 2 to 50% by weight of a styrene-soluble elastomer and c) conventional additives in effective amounts.
14. A process for the production of foam moldings, wherein an expandable styrene polymer as claimed in claim -11- O.Z. 0050/40807 1, in the form of particles, is expanded by heating above the softening point, and the resulting foam par-ticles are welded to one another by heating in molds which close without a gas-tight seal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3915602A DE3915602A1 (en) | 1989-05-12 | 1989-05-12 | EXPANDABLE STYRENE POLYMERS |
| DEP3915602.8 | 1989-05-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2016587A1 true CA2016587A1 (en) | 1990-11-12 |
Family
ID=6380557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002016587A Abandoned CA2016587A1 (en) | 1989-05-12 | 1990-05-11 | Expandable styrene polymers |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0397001B1 (en) |
| JP (1) | JPH02311542A (en) |
| KR (1) | KR900018178A (en) |
| AT (1) | ATE93533T1 (en) |
| CA (1) | CA2016587A1 (en) |
| DE (2) | DE3915602A1 (en) |
| ES (1) | ES2058663T3 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5145878A (en) * | 1991-02-14 | 1992-09-08 | Klaus Hahn | Drying of finely divided, expandable styrene polymers |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5239007A (en) * | 1991-10-22 | 1993-08-24 | Arco Chemical Technology, L.P. | Oil-absorbent compositions |
| DE4231512A1 (en) * | 1992-09-21 | 1994-03-24 | Basf Ag | Expandable thermoplastic polymers containing organic boron-silicon compounds and process for their production |
| KR100236851B1 (en) * | 1993-04-27 | 2000-01-15 | 야마모토 카즈모토 | Expanded foamed bead of a rubber-modified styrene polymer |
| DE4416862A1 (en) * | 1994-05-13 | 1996-02-22 | Basf Ag | Expandable styrene polymers |
| DE4416863A1 (en) * | 1994-05-13 | 1995-11-16 | Basf Ag | Expandable styrene polymers |
| DE4416861A1 (en) * | 1994-05-13 | 1995-11-16 | Basf Ag | Expandable styrene polymers |
| DE4416852A1 (en) * | 1994-05-13 | 1995-11-16 | Basf Ag | Expandable styrene polymers |
| JP2002138184A (en) | 2000-11-02 | 2002-05-14 | Tokai Rubber Ind Ltd | High damping elastomer composition |
| EP2630186A1 (en) * | 2010-10-18 | 2013-08-28 | Total Research & Technology Feluy | Expandable vinyl aromatic polymers |
| IT201800008073A1 (en) * | 2018-08-13 | 2020-02-13 | Versalis Spa | EXPANDABLE VINYLAROMATIC POLYMER COMPOSITION WITH IMPROVED MECHANICAL AND INSULATING PROPERTIES |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2965593A (en) * | 1954-08-17 | 1960-12-20 | Thomas J Dietz | Process of polymerizing mixtures of polyorganosiloxanes and vinyl monomers and product obtained |
| US3461188A (en) * | 1965-08-23 | 1969-08-12 | Monsanto Co | Polyblends prepared by polymerizing vinyl monomers in the presence of cross-linked rubber |
| ES366286A1 (en) * | 1968-08-07 | 1971-02-16 | Koppers Co Inc | Improvements in or relating to expandable polymers |
| DE2237491B2 (en) * | 1972-07-31 | 1976-05-06 | Chemische Werke Hüls AG, 4370 Mari | THERMOPLASTIC MOLDING COMPOUNDS ON THE BASIS OF STYRENE POLYMERIZED |
| US3923923A (en) * | 1974-03-11 | 1975-12-02 | Dow Corning | Toughened polystyrene |
| DE3901329A1 (en) * | 1989-01-18 | 1990-07-19 | Basf Ag | EXPANDABLE STYRENE POLYMERISATES WITH HIGH OIL RESISTANCE AND METHOD FOR THE PRODUCTION THEREOF |
-
1989
- 1989-05-12 DE DE3915602A patent/DE3915602A1/en active Granted
-
1990
- 1990-04-25 JP JP2107717A patent/JPH02311542A/en active Pending
- 1990-04-30 ES ES90108204T patent/ES2058663T3/en not_active Expired - Lifetime
- 1990-04-30 DE DE90108204T patent/DE59002427D1/en not_active Expired - Lifetime
- 1990-04-30 AT AT90108204T patent/ATE93533T1/en not_active IP Right Cessation
- 1990-04-30 EP EP90108204A patent/EP0397001B1/en not_active Expired - Lifetime
- 1990-05-11 CA CA002016587A patent/CA2016587A1/en not_active Abandoned
- 1990-05-12 KR KR1019900006867A patent/KR900018178A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5145878A (en) * | 1991-02-14 | 1992-09-08 | Klaus Hahn | Drying of finely divided, expandable styrene polymers |
Also Published As
| Publication number | Publication date |
|---|---|
| ES2058663T3 (en) | 1994-11-01 |
| KR900018178A (en) | 1990-12-20 |
| DE3915602C2 (en) | 1991-10-10 |
| DE3915602A1 (en) | 1990-11-15 |
| DE59002427D1 (en) | 1993-09-30 |
| EP0397001A1 (en) | 1990-11-14 |
| JPH02311542A (en) | 1990-12-27 |
| ATE93533T1 (en) | 1993-09-15 |
| EP0397001B1 (en) | 1993-08-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |