Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/14—Glass
• • 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
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08L79/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
  • C08L79/085—Unsaturated polyimide precursors
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
  • C08L9/02—Copolymers with acrylonitrile

Definitions

• the invention is concerned with plastics molding materials, and particularly moulding materials based on thermoplastics.
• thermoplastics materials such as polystyrene and styrene-acrylonitrile copolymer (SAN) have excellent moulding properties but are brittle so that the impact resistance of articles moulded from them is not good.
• SAN styrene-acrylonitrile copolymer
• brittle thermoplastics polymers such as polystyrene and SAN can be rendered less brittle by incorporation therein of rubber. This so called “toughening” can increase the impact strength over untreated polymer by a factor of from 2 to 6. However, it has been found that when the impact strength is increased in this way there is an accompanying undesirable decrease in strengths and moduli, which may be up to 50% lower than those of the unmodified polymer.
• moulding compositions comprising thermoplastics materials, a reinforcing filler which is either glass fibres or mica, and a minor proportion of a polyimide prepolymer, which is capable of thermosetting.
• the polyimide prepolymers concerned are addition polymers and their preparation is described in UK Patent Nos. 1,190,718; 1,355,401; 1,355,402; 1,355,403; 1,355,405; 1,355,406 and 1,355,407.
• the effect of the polyimide prepolymers in these compositions is to increase strength and impact resistance of mouldings produced therefrom.
• US Patent No. 3,717,615 discloses polymer compositions based on a mixture of a mono-imide of specified general formula and a bis-imide of specified general formula. It also discloses that the mono-and bis-imides can be co-reacted with various thermoplastics during copolymerisation of the imides and that the resulting compositions may be compounded with fillers including glass fibres, and with synthetic rubbers.
• the polyimides prepared in this specification are, however, the basis of the compositions described, and the final product in each case is a thermoset material. Where thermosplastics materials are used, their proportion is less than that of the mixture of imides and they are co-reacted in the polymerisation of the imides.
• US Patent No. 3,678,075 discloses reacting an organic diamine with an aliphatically unsaturated dicarbonyl reagent in a solvent system to produce a polyimide by a condensation reaction.
• the polyimide is said to be able to be employed in combination with various thermoplastics polymers and can be compounded with fillers including glass fibre.
• the compositions disclosed are thermosetting, and the polyimide is not an addition polymer, nor is the inclusion of rubbery polymers in the compositions disclosed.
• thermoplastic moulding material comprising a styrene-acrylonitrile copolymer containing a ratio of styrene to acrylonitrile in the range 85:15 to 60:40 by weight, and having a melt flow index (MFI) of 2 to 25 g/10 mins at 230°C under a 5 Kg load, an elastomeric material having an elongation at break greater than the styrene-acrylonitrile copolymer, in an amount of 1 to 50% by weight of the moulding material, and a reinforcing filler comprising glass fibres or mica characterised in that the material also comprises a poly-imide pre-polymer being the reaction product of a polyamine and a bis-imide of an unsaturated carboxylic acid and being capable of reacting further to give a thermoset resin.
• MFI melt flow index
• the toughening agent is an elastomeric material having an elongation at break greater than the styrene/acrylonitrile copolymer. It is preferred that the elongation at break should be significantly greater than that of the styrene-acrylonitrile copolymer, for example at least 10 times as great.
• both sulphur vulcanisable rubbers and thermoplastic rubbers can be used, vulcanisable rubbers preferably being used in a substantially uncured or partially cured state.
• the toughening agent is included in an amount of from 1 to 50% by weight (based on the weight of the total composition) preferably from 1 to 30% and more preferably from 5 to 20%.
• the toughening agent preferably has a glass transition temperature below 20°C.
• Preferred sulphur vulcanisable elastomeric materials are rubbers such as nitrile rubbers, polyacrylate rubbers and polyurethanes.
• thermoplastic rubbers are block copolymers containing styrene e.g. block copolymers of styrene and butadiene, which have been found particularly useful in the compositions of this invention although other thermoplastic rubbers such as polybutylene have also been found effective.
• the elastomeric material used must be compatible with the styrene/acrylonitrile copolymer i.e. able to be compounded with the SAN in a satisfactory manner, and should be an elastomer which improves the impact resistance of the copolymer when so compounded, in the absence of other materials.
• the polyimide prepolymer is preferably incorporated in an amount of from 0.1 to 10% by weight (based on the weight of the total composition) more preferably 0.5% to 5.0% by weight.
• Polyimides which can be used are described, inter alia, in British Patent Specifications Nos. 1,190,718; 1,355,401; 1,355,402; 1,355,403; 1,355,405; 1,355,406 and 1,355,407, and are believed to be formed by an addition reaction between the polyamine and the unsaturated bis-imide, rather than by a condensation reaction, the latter being the case with other polyimides.
• the polyimide prepolymer is the reaction product of a primary diamine containing not more than 30 carbon atoms and an N,N' bis imide of general formula in which D represents a divalent radical containing a carbon-carbon double bond, and A is a divalent radical containing at least two carbon atoms.
• the primary diamine is an aromatic compound, e.g. containing at least one phenylene group.
• a preferred compound is the compound of formula
• radical D in the N,N' bis imide is derived from an a;/3 unsaturated dicarboxylic acid such as maleic acid.
• the radical A is preferably an aromatic radical containing at least one phenylene group such as
• the number average molecular weight of the prepolymer is preferably no more than 5000.
• the molar ratio of bis-imide to polyamine is preferably in the range 1.2 to 1 up to 50 to 1, more preferably in the range 1.2 to 1 up to 2.9 to 1.
• the amount of filler present preferably does not exceed 50% by weight of the total composition and preferably is not less than 15 per cent.
• the particularly preferred range is 20 to 40 per cent by weight of the total composition.
• composition may optionally also include one or more other additives such as antioxidants, flame retardants, blowing agents, antistatic agents and pigments.
• additives such as antioxidants, flame retardants, blowing agents, antistatic agents and pigments.
• the composition contains at least 30% by weight of styrene/acrylonitrile copolymer.
• the composition can be prepared by any suitable method such as by milling, extrusion, injection moulding all of which are known per se.
• the order in which the components of the composition are compounded together is not important.
• the polyimide prepolymer can be added to the base polymer and the resultant mixture combined with the toughening agent.
• the polyimide prepolymer can be added to the toughening agent and the resultant mixture combined with the base polymer.
• the polyimide prepolymer can be applied as a dressing to the filler prior to incorporation of the filler into the composition i.e. when glass fibre is used the polyimide prepolymer may be used in a dressing for the glass fibres.
• the materials were compounded on a twin-screw extruder at barrel temperatures of 200°C, 125°C, 125°C and 190°C (die) and the extruded composition was chopped into pellets.
• the resultant material was formed into test bars by injection moulding using conventional moulding conditions for reinforced styrene/acrylonitrile copolymer (220/250°C barrel temperatures).
• the test bars were tested for tensile strength, tensile modulus, flexural strength, flexural modulus and impact strength. The results are shown in the following Table 1.
• Example 2 The same procedure was followed as in Example 1 save that the amount of nitrile rubber was increased to 10% (Example 2) and 15% (Example 3). The products were tested and the results are set out in the Table 1.
• Example 2 A composition was made in the same manner as in Example 1 except that both "Kerimid 601" and the nitrile rubber "Krynac 802" were omitted. Test bars formed from the composition by injection moulding were tested for the same properties as in Example 1. The results are set out in Table 2.
• a composition was made in the same manner as in Example 1 except that the nitrile rubber "Krynac 802" was omitted.
• Example 2 A composition was made in the same way as in Example 1 but "Kerimid 601" was omitted. The results of tests made on test bars formed from the composition are shown in the Table 2.
• compositions of increasing glass fibre content were prepared each containing the styrene/acrylonitrile copolymer of Example 1.
• compositions of corresponding glass content were prepared in which 2 parts SAN by weight per 100 of composition were replaced by the polyimide prepolymer KERIMID 601; further compositions of corresponding glass content were prepared in which 15 parts of SAN per 100 of composition were replaced by the nitrile rubber KRYNAC 802; and further compositions of corresponding glass content were prepared in which 17 parts of SAN by weight per 100 of composition were replaced by 2 parts by weight of the polyimide prepolymer KERIMID 601 and 15 parts by weight of the nitrile rubber KRYNAC 802.
• a composition was prepared by compounding together the following ingredients in a twin-screw extruder in the same manner as described in Example 1.
• the ingredients were 60 parts by weight of styrene/acrylonitrile copolymer (Monsanto QE 1044 as in Example 1), 15 parts by weight of glass fibres, (ECR 1346 as in Example 1) 15 parts by weight of talc and 10 parts by weight of fire retardants.
• the fire retardants consisted of a 3:1 w/w mixture of decabromobiphenyl (Flammex B10 commercially available from Berk Ltd.) and Antimony Trioxide.
• Three comparable compositions were prepared by respectively replacing (i) 2 parts of the styrene/acrylonitrile copolymer (SAN) by 2 parts of the polyimide prepolymer KERIMID 601, (ii) 15 parts of the SAN by 15 parts of PERBUNAN N2810 (a nitrile rubber containing 28% by weight of acrylonitrile and commercially available from Wegriken Bayer AG) and (iii) 7 parts of SAN by 2 parts of the KERIMID 601 and 5 parts of the PERBUNAN N2810.
• SAN styrene/acrylonitrile copolymer
• PERBUNAN N2810 a nitrile rubber containing 28% by weight of acrylonitrile and commercially available from Wegriken Bayer AG
• 7 parts of SAN by 2 parts of the KERIMID 601 and 5 parts of the PERBUNAN N2810.
• compositions were prepared using SAN and glass fibre as used in Example 1. Each composition contained 30% by weight of glass fibre.
• compositions contained 5% by weight of a nitrile rubber (KRYNAC 802) one having uncured rubber incorporated into it and the other having cured rubber incorporated into it.
• the other two compositions also contained 5% of uncured and cured rubber respectively but additionally contained 2% by weight of the polyimide prepolymer KERIMID 601.
• SAN made up the whole of the balance of the composition.
• the compounding was carried out in a twin screw extruder under the same conditions as in Example 1, and test mouldings were injection moulded from each of the four compositions.
• the cured rubber was a compounded rubber in which the following formulation was compounded on a mill and press cured for 10 minutes at 150°C in sheets 1.5 mm thick. Under these conditions the rubber was substantially fully vulcanised i.e. 95% of available cross linking sites used up.
• the rubber formulation was:-
• Example 1 The following examples illustrate the use of the invention with various kinds of commercially available synthetic rubbers.
• the composition was compounded as in Example 1, using the same type of SAN, glass fibre and polyimide prepolymer as in Example 1, to the following formulation: Glass fibre 30 parts by weight, polyimide prepolymer 2 pbw, Rubber 5 pbw and SAN 63 pbw.
• Test mouldings were made as before by injection moulding, and the properties of the mouldings were measured.

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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)
• Materials For Medical Uses (AREA)

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• 1978
  • 1978-06-27 US US05/919,565 patent/US4212792A/en not_active Expired - Lifetime
  • 1978-06-29 DE DE7878300104T patent/DE2861259D1/de not_active Expired
  • 1978-06-29 EP EP78300104A patent/EP0000429B1/en not_active Expired
  • 1978-07-04 IT IT50159/78A patent/IT1106420B/it active
  • 1978-07-05 DK DK303378A patent/DK153560C/da not_active IP Right Cessation
  • 1978-07-05 JP JP8184178A patent/JPS5417962A/ja active Granted
  • 1978-07-05 NO NO782343A patent/NO158748C/no unknown

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