Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions 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; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
  • C08L25/12—Copolymers of styrene with unsaturated nitriles
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L35/00—Compositions 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 a carboxyl radical, and containing at least one other carboxyl radical in the molecule, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
  • C08L35/06—Copolymers with vinyl aromatic monomers

Definitions

• the invention relates to a polymer composition containing a polymer A that contains vinyl-aromatic monomeric units and acrylonitrile monomeric units and a polymer B that contains vinyl-aromatic monomeric units, dicarboxylic acid anhydride monomeric units and/or imide monomeric units.
• Such a polymer composition is known from DE-A- 3.332.326.
• the known polymer composition has good processability and great stiffness. Although the polymer composition has a relatively high glass transition temperature, said glass transition temperature is still insufficiently high for a large number of applications.
• the aim of the invention is to provide a polymer composition that does not have the aforementioned drawback. This is achieved because polymer B in the polymer composition according to the invention contains at least 1 wt.% spiroduactone monomeric units.
• the resultant higher glass transition temperature makes it possible to use the polymer composition according to the invention in articles that are exposed to higher temperatures. It is for example possible to use the polymer composition according to the invention in automotive parts that are mounted on or in the immediate vicinity of the motor, whereas this is not really possible with the known polymer composition.
• a further advantage of the polymer composition according to the invention is the greatly improved thermal stability relative to that of the known polymer composition. Because of this, the polymer composition can be processed into articles of a more complex design at even higher temperatures, and hence at a lower viscosity. In addition. the polymer composition can be used in articles that are exposed to elevated temperatures for long periods too.
• Polymer A generally contains 2-50 wt.% acrylonitrile monomeric units and 50-98 wt.% vinyl-aromatic monomeric units. Suitable vinyl-aromatic monomers are styrene, alpha-methylstyrene, para-methylstyrene or a mixture thereof. Preferably, use is made of styrene.
• polymer A may contain small amounts of one or more other monomeric units such as for example methylmethacrylate monomeric units.
• polymer A has a weight average molecular weight of between 30,000 and 150,000 kg/kmol.
• Polymer B is known per se from O-90/06956.
• Polymer B can be prepared by preparing a polymer C that contains dicarboxylie-anhydride monomeric units and vinyl-aromatic monomeric units in a first step, using one of the known processes, and then converting polymer C into polymer B in a second step.
• Suitable vinyl-aromatic monomers are styrene, alpha-methylstyrene, para-methylstyrene and mixtures thereof. Preferably, use is made of styrene.
• Suitable dicarboxylic anhydrides are maleic anhydride, chloromaleic anhydride, citraconic anhydride, cyclohexylmaleic anhydride, benzylmaleic anhydride, phenylmaleic anhydride, aconitic anhydride, propylmaleic anhydride and mixtures hereof.
• the conversion of polymer B into polymer C may be effected via heating to a temperature of preferably 200- 300°C. During the heating a conversion takes place in the chain of the polymer, in which dicarboxylic anhydride-vinyl aromatic monomer-dicarboxylic anhydride (Formula I) reacts to form spiroduactone (Formula II) according to the equation:
• the polymer must be heated for a sufficient length of time to effect the desired conversion.
• this involves the risk that secondary thermal decomposition processes in the polymer may start to play an important part after some time, before the desired conversion is realized.
• the heating is preferably done in the presence of a basic catalyst. By using the catalyst the desired conversion can be realized quicker and at a lower temperature.
• Suitable catalysts are tertiary amines; preferably use is made of triethylamine (TEA) or 1,4- diazobicyclo[2,2,2]octane (DABCO) .
• TAA triethylamine
• DABCO 1,4- diazobicyclo[2,2,2]octane
• the reaction can be carried out by heating the polymer per se, in which case the reaction takes place while the polymer is in a melted condition. It is also possible to carry out the reaction while the polymer is in solution.
• Suitable solvents are dimethylformamide, tetrahydrofuran, acetone and methylethyl ketone or other ketones.
• polymer B preferably contains at least 2 wt.% spiroduactone monomeric units. In another preferred embodiment polymer B contains at least 4 wt.% spiroduactone monomeric units. In yet another preferred embodiment polymer B contains at least 6 wt.% spiroduactone monomeric units.
• polymer B has a weight average molecular weight of between 30,000 and 200,000 kg/kmol. If polymer B is prepared from polymer C, as described above, then this polymer B thus obtained after the conversion to the spiroduactone will still contain a certain amount of dicarboxylic-anhydride monomeric units, dependent on the distribution of the dicarboxylic-anhydride and vinyl- aromatic monomeric units across the chain of polymer C. It is also possible to only partly complete the conversion to the spiroduactone, which will result in an even greater amount of dicarboxylic-anhydride monomeric units in polymer B.
• Polymer B preferably contains 3-35 wt.% spiroduactone monomeric units and 5-45 wt.% dicarboxylic-anhydride monomeric units.
• the ratio of the amount of acrylonitrile monomeric units in polymer A and the amount of dicarboxylic-anhydride monomeric units in polymer B is between 0.3 and 2.2.
• the ratio of the amount of acrylonitrile monomeric units in polymer A and the amount of dicarboxylic-anhydride monomeric units in polymer B is between 0.7 and 1.6.
• a polymer composition according to the invention is obtained, in which polymer A and polymer B are completely molecularly miscible in any mixing ratio. This can be inferred from for example the fact that the polymer composition has a single, sharp glass transition temperature. If, besides polymer A and polymer B, the polymer composition contains no other additives such as fillers then the polymer composition is furthermore transparent.
• polymer B of the polymer composition according to the invention may contain imide monomeric units.
• imide in polymer B use may be made of N-phenylmaleimide, malimide, citraconimide, itaconimide, aconimide, N-methyl- maleimide or mixtures thereof. Very good results are obtained if polymer B contains as monomeric units: 17-22 % (wt) maleic acid anhydride
• composition shows optimal deflection temperature, mechanical properties and processability.
• a polymer composition according to the invention that has good impact resistance is obtained if the polymer composition contains a rubber as an impact modifier.
• a rubber with a glass transition temperature of below -10°C.
• suitable rubbers are polybutadiene, EPDM, hydroxylated EPDM, polybutylacrylate and silicone rubber.
• the rubber is grafted with a polymer that is miscible with the polymer composition. It is for example possible for the rubber to be grafted with polymer A or polymer B.
• the polymer composition according to the invention may contain the usual additives such as stabilisers, processing aids, fillers and fibres, for example glass fibres.
• a granulate may be produced consisting of the polymer composition according to the invention by mixing polymer A, polymer B, eventually a rubber and eventually the usual additives in a melt kneader and forcing the melt through a granulator.
• the granulate consisting of the polymer composition is very suitable for use in the production of for example automotive parts such as dashboards, valve caps, distributor caps, housings for electronic and electrical equipment, switches, connectors and the like.
• the invention is further elucidated with reference to the following examples without being limited thereto.
• the throughput was 6 kg/hour.
• the melting temperature was 250°C.
• TEA was continuously injected into the extruder and mixed with the melted polymer.
• samples 1-15 of polymer B were obtained, which contained varying amounts of spirodilactone monomeric units.
• the MA content of the samples and the initial polymers C was determined using a Perkin Elmer (R) IR apparatus, type 1760 FT-IR. This was then used to calculate the spirodilactone monomeric units content of the samples with the aid of the equation given above in the specification of the present application, on the assumption that no side reactions took place.
• R Perkin Elmer
• T g The glass transition temperature (T g ) was determined with the aid of a Perkin Elmer (R) DSC apparatus, type DSC 7. The samples weighed 10-15 mg. The heating rate was 10°C/minute.
• SAN 20/2 is a mixture of 50 wt.% SAN 20 (Table 2) and 50 wt.% sample 2 (Table 1).
• Tables 3, 4 and 5 show the influence of the spirodilactone monomeric units content of the polymer on the. glass transition temperature of mixtures of SAN 26 and polymer B samples 1, 2, 5, 7, 10, 11, 12, 14, and 15.
• Tables 3-5 show that the glass transition temperature of the mixtures to a great extent increases with the spirodilactone monomeric units content of polymer B.
• the miscibility of polymer A and polymer B was determined by measuring the glass transition temperatures of the mixtures by means of DSC. Polymers A and B are completely miscible if the mixture has one glass transition temperature. Polymers A and B are partly miscible if the mixture has two glass transition temperatures, which are higher or lower than the glass transition temperatures of the polymers A and B used. Table 6 shows the results obtained with a series of mixtures of different SAN copolymers and sample 2; Table 7 shows the results obtained with a series of mixtures of different SAN copolymers and sample 10.
• Polymers A and B are partly miscible in mixtures SAN 13.8/2, SAN 29/2, SAN 33/2 and SAN 13.8/10 and completely miscible in the other mixtures.
• the miscibility of polymer B with SAN appears to increase with the MA content of polymer B (sample 2, 17.6 wt.% MA; sample 10, 21.7 wt.% MA).
• Polymer B samples 1-15 were mixed with ABS, type Ronfalin (R) TZ 220 from DSM, as indicated in example I.
• the mixing ratio was in each case 60 wt.% ABS and 40 wt.% polymer B.
• the mixtures were processed into flat plates with a thickness of 3 mm and a length and width of 65 mm using an Arburg (R) Allround 220-90-350 injection-moulding machine.
• the melting temperature of the mixture in the injection-moulding machine was 310°C, the residence time of the mixture at this temperature was 5 minutes.
• the quality of the surface of the flat plates - the number of silver streaks per unit of surface area - was a measure of the thermal stability (TS) of the mixtures.
• SMA styrene-maleic anhydride copolymers
• T g of the samples was determined as indicated in example I. Table 9 shows the results.
• the MA monomeric units contents of the successive SMA copolymers of Table 9 are comparable with the MA contents of the polymer B samples of Tables 4 and 5.

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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)
• Compositions Of Macromolecular Compounds (AREA)

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• 1991
  • 1991-10-09 BE BE9100926A patent/BE1005452A4/nl not_active IP Right Cessation
• 1992
  • 1992-10-08 AU AU28710/92A patent/AU2871092A/en not_active Abandoned
  • 1992-10-08 WO PCT/NL1992/000179 patent/WO1993007212A1/en not_active Application Discontinuation
  • 1992-10-08 JP JP5506808A patent/JPH08502763A/ja active Pending
  • 1992-10-08 EP EP92922027A patent/EP0607322A1/en not_active Withdrawn
  • 1992-10-16 TW TW81108232A patent/TW226391B/zh active

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