DE19805586A1 - Glass fiber reinforced styrene / diphenylethene copolymers - Google Patents

Abstract

The invention relates to thermoplastic moulding materials containing the following: A) 30 to 98 wt. % of a copolymer consisting of vinyl aromatic monomers and 1.1-diphenylethylene or derivatives thereof which are optionally substituted with alkyl groups with up to 22 C-atoms on the aromatic rings; B) 1 to 50 wt. % of fibrous or particulate fillers or mixtures thereof; C) 1 to 20 wt. % of a polymer or polymer mixtures modified with polar groups and D) 0 to 68 wt. % of other additives, the sum of A), B), and C) being 100 wt. %.

Description

The invention relates to thermoplastic molding compositions containing

• A) 30 to 98 wt .-% of a copolymer of vinyl aromatic Mo nomers and 1,1-diphenylethene or its aromatic If necessary, wrestle with alkyl groups with up to 22 carbon atoms substituted derivatives,
• B) 1 to 50 wt .-% fibrous or particulate fillers or their mixtures,
• C) 1 to 20 wt .-% of a modified with polar groups Polymers or polymer mixtures and
• D) 0 to 68% by weight of further additives,

the sum of A), B) and C) being 100% by weight.

Furthermore, the invention relates to the use of the thermopla tical molding compounds for the production of fibers, films and mold bodies as well as fibers, foils and molded bodies made of them.

Thermoplastic molding compounds based on styrene / 1,1-diphenyl Ethene copolymers are known for example from WO 95/34586. They have high glass transition temperatures and stiffness, however have insufficient toughness for some applications on. It has therefore been tried variously, the styrene / 1,1-Di to modify phenylethene copolymers with rubbers. Through the However, toughness modification reduces the high rigidity.

The object of the present invention was therefore thermoplastic Molding compounds with good heat resistance and rigidity to provide high toughness at the same time.

Accordingly, the thermoplastic described above Molding compounds found.

As component A), the molding compositions contain 30 to 98% by weight, be preferably 40 to 90% by weight and very particularly preferably 50 to 80% by weight of a copolymer of vinyl aromatic monomers and 1,1-Diphenylethen or its given on the aromatic rings  optionally substituted with alkyl groups with up to 22 carbon atoms Derivatives.

A random copolymer of styrene and 1,1-diphenylethylene is preferably used. The content of 1,1-diphenylethene in the copolymer is expediently from 15 to 63% by weight, preferably from 15 to 45% by weight, or the corresponding molar amount of a derivative derived from 1,1-diphenylethylene. The weight average molecular weight M _w of component A is 10,000 to 2,000,000 g / mol, preferably 20,000 to 1,000,000 and very particularly preferably 50,000 to 500,000 g / mol.

The copolymers that can be used as component A) are per se known. Their manufacture is described in detail in WO 95/34586 wrote.

The molding compositions 1 according to the invention contain component B) up to 50% by weight, preferably 5 to 45% by weight and particularly preferred 10 to 40 wt .-% fibrous or particulate fillers or de ren mixtures.

Preferred fibrous fillers and reinforcing agents are Carbon fibers, potassium titanate whiskers, aramid fibers and special prefers glass fibers. When using glass fibers these for better compatibility with a size and be equipped with an adhesion promoter. In general they have glass fibers used have a diameter in the range of 6 to 20 µm.

The incorporation of these glass fibers can take the form of both glass fibers and in the form of endless strands (rovings) The average length of the glass is in the finished injection molded part fibers preferably in the range of 0.08 to 0.5 mm.

Suitable particulate fillers are amorphous silica, Magnesium carbonate (chalk), powdered quartz, mica, talc, Feldspar and in particular calcium silicates such as wollastonite and Kaolin (especially calcined kaolin).

The fibrous or particulate fillers are preferred a reactive size, for example with a Aminosilane.

The molding compositions 1 according to the invention contain component C) to 20 wt .-%, preferably 1 to 10 wt .-% of a with polar group modified polymers or polymer mixtures.  

As polymers that are modified with polar groups preferably polyphenylene ether and styrene polymers used.

The polymers or polymer mixtures preferably contain as polar groups at least one carbonyl, carboxylic acid, acid anhydride, acid imide, carboxylic acid ester, carboxylate, amino, Hydroxyl, epoxy, oxazoline, isocyanate, urethane, urea, Lactam or halobenzyl group. Expediently as polar groups used those with the size of the compo nente C) react.

Such modified with polar groups polyphenylene ether as well Processes for their production are known per se and described for example in DE-A 41 29 499.

As component C) modified with polar groups, polyphenylene ethers which are composed of are preferably used

• c ₁ ) 70 to 99.95% by weight of a polyphenylene ether,
• c ₂ ) 0 to 25% by weight of a vinyl aromatic polymer,
• c ₃ ) 0.05 to 5% by weight of at least one compound which contains at least one double or triple bond and at least one functional group selected from the group of carboxylic acids, carboxylic esters, carboxylic anhydrides, carboxamides, epoxides, oxazolines or urethanes.

Examples of polyphenylene ether c ₁ ) are
Poly (2,6-dilauryl-1,4-phenylene) ether,
Poly (2,6-diphenyl-1,4-phenylene) ether,
Poly (2,6-dimethoxy-1,4-phenylene) ether,
Poly (2,6-diethoxi-1,4-phenylene) ether,
Poly (2-methoxy-6-ethoxy-1,4-phenylene) ether,
Poly (2-ethyl-6-stearyloxy-1,4-phenylene) ether,
Poly (2,6-dichloro-1,4-phenylene) ether,
Poly (2-methyl-6-phenyl-1,4-phenylene) ether,
Poly (2,6-dibenzyl-1,4-phenylene) ether,
Poly (2-ethoxy-1,4-phenylene) ether,
Poly (2-chloro-1,4-phenylene) ether,
Poly (2,5-dibromo-1,4-phenylene) ether.

Polyphenylene ethers in which the substituents are alkyl radicals having 1 to 4 carbon atoms, such as
Poly (2,6-dimethyl-1,4-phenylene) ether,
Poly (2,6-diethyl-1,4-phenylene) ether,
Poly (2-methyl-6-ethyl-1,4-phenylene) ether,
Poly (2-methyl-6-propyl-1,4-phenylene) ether,
Poly (2,6-dipropyl-1,4-phenylene) ether and
Poly (2-ethyl-6-propyl-1,4-phenylene) ether.

Examples of preferred vinylaromatic polymers c ₂ ) can be found in the monograph by Olabisi, pp. 224 to 230 and 245. Vinyl aromatic polymers made from styrene, chlorostyrene, α-methylstyrene and p-methylstyrene are only representative here; in subordinate proportions (preferably not more than 20, in particular not more than 8% by weight), comonomers such as (meth) acrylonitrile or (meth) acrylic acid esters can also be involved in the structure. Particularly preferred vinyl aromatic polymers are polystyrene and impact modified polystyrene. It is understood that mixtures of these polymers can also be used. The production is preferably carried out according to the method described in EP-A 302 485.

Suitable modifiers c ₃ ) are, for example, maleic acid, methyl maleic acid, itaconic acid, tetrahydrophthalic acid, their anhydrides and imides, fumaric acid, the mono- and diesters of these acids, for. B. from C ₁ - and C ₂ - to C ₈ alkanols, the mono- or diamides of these acids such as N-phenylmaleinimide, maleic hydrazide. N-vinylpyrrolidone and (meth) acryloylcaprolactam may also be mentioned, for example.

Another group of modifiers includes, for example the acid chloride of trimellitic anhydride, benzene-1,2-dicar bonic anhydride-4-carboxylic acid acetic anhydride, pyromellite acid dianhydride, chloroethanoylsuccinaldehyde, chloroformylsuccin aldehyde, citric acid and hydroxysuccinic acid.

Particularly preferred polyphenylene ether C) modified with polar groups in the molding compositions according to the invention are obtained by modification with maleic acid, maleic anhydride or fumaric acid. Such polyphenylene ethers preferably have a molecular weight (weight average M _w ) in the range from 10,000 to 80,000, preferably from 20,000 to 60,000.

This corresponds to a reduced specific viscosity η _red of 0.2 to 0.9 dl / g, preferably 0.35 to 0.8 and in particular 0.45 to 0.6, measured in a 1% by weight solution in chloroform at 25 ° C according to DIN 53 726.

The molding compositions 0 to 68% by weight contain further additives. These include at for example impact-modifying polymers, flame retardants,  Stabilizers, lubricants, antiblocking agents, release agents, anti statics and colorants.

The impact modifi used to improve toughness decorative polymers (also impact modifiers, elastomers or chewing Tschuke called) are in amounts of 0 to 30, preferably 3 to 20 and in particular 5 to 15 wt .-% used.

As rubbers which increase the toughness of the copolymers A), z. B. called the following:
Polyoctenylenes, graft rubbers with a cross-linked, elastomeric core, which is derived, for example, from butadiene, isoprene or alkyl acrylates and a graft shell made from polystyrene, further copolymers from ethylene and acrylates or methacrylates, and the so-called ethylene-propylene (EP) - and ethylene - Propylene diene (EPDM) rubbers, furthermore the EP or EPDM rubbers grafted with styrene.

Furthermore, block copolymers with up to six, preferably with up to four identical or different blocks, both linear as well as star-shaped (so-called radial block copolymers) can be connected, are used. Block are preferred copolymers containing at least one block of vinyl aromatic Monomers, which are preferably at the end of the polymer chain finds own.

Mixtures of block copolymers of different structures, e.g. B. Mixtures of two and three block copolymers or of whole or partially hydrogenated and unhydrogenated block copolymers can also be used.

Such impact modifying polymers are known per se and described in the literature. Just for example here US-A 4 085 163, US-A 4 041 103, US-A 3 149 182, US-A 3 231 635 and US-A 3,462,162.

Corresponding products are also commercially available, e.g. B. a Polyoctylene of the designation Vestenamer® (Hüls AG), metallocenka analytical polyethylenes like Affinity® (DOW) or Luflexen® (BASF) and a large number of suitable block copolymers with at least one egg vinyl aromatic and an elastomeric block. Exemplary be the Cariflex®-TR types (Shell), the Kraton®-G types (Shell), the Finaprene® types (Fina), the Europrene®-SOL-TR types (Enichem) and Styroflex® and Styrolux® (BASF).  

The molding compositions according to the invention can also provide flame protection medium in a concentration of 0 to 20 wt .-%, preferred from 1 to 15% by weight, in particular 3 to 10% by weight, based on the total weight of the molding compound.

Suitable flame retardants are e.g. B. polyhalodiphenyl, poly halodiphenyl ether, polyhalophthalic acid and their derivatives, Polyhalogenated oligo- and polycarbonates, the corresponding Bromine compounds are particularly effective.

Examples of these are polymers of 2,6,2 ', 6'-tetrabromobisphenol A, tetrabromophthalic acid, 2,6-dibromophenol and 2,4,6-tri bromphenols and their derivatives.

The preferred flame retardant is elemental phosphorus. In the As a rule, the elementary phosphorus with z. B. polyurethanes or Aminoplasts can be phlegmatized or coated. Also are Concentrates of red phosphorus e.g. B. in a polyamide, elasto suitable or polyolefin.

Combinations of elemental phosphorus are particularly preferred with 1,2,3,4,7,8,9,10,13,13,14,14-dodecachloro-1,4,4a, 5,6,6a, 7, 10,10a, 11,12,12a-dodecahydro-1,4: 7,10-dimethanodibenzo (a, e) -cy clooctan (Dechlorane®Plus, Occidental Chemical Corp.) and optionally a synergist z. B. antimony trioxide.

Phosphorus compounds such as organic phosphates, phosphonates, Phosphinates, phosphine oxides, phosphines or phosphites are just if preferred. Triphenylphosphine oxide and Called triphenyl phosphate. This can be used alone or mixed with Hexabromobenzene or a chlorinated biphenyl and, optionally, Antimony oxide can be used.

Typical of the preferred phosphorus compounds that can be used in accordance with the present invention are those of the following general formula

where Q represents the same or different hydrocarbon radicals residues such as alkyl, cycloalkyl, aryl, alkyl substituted aryl and aryl-substituted alkyl, halogen, hydrogen and  their combinations, provided that at least one of the for Q is an aryl radical.

Examples of such suitable phosphates are e.g. B. the following:
Phenyl bisdodecyl phosphate, phenyl bis neopentyl phosphate, phenyl ethylene hydrogen phosphate, phenyl bis (3-5,5'-trimethylhexyl phosphate), ethyl diphenyl phosphate, 2-ethyl hexyl di (p-tolyl) phosphate, bis (2-ethyl hexyl) phenyl phosphate, tri (non , Phenylmethyl hydrogen phosphate, di (dodecyl) p-tolyl phosphate, tri cresyl phosphate, triphenyl phosphate, dibutylphenyl phosphate and diphenyl hydrogen phosphate. The preferred phosphates are those where each Q is aryl. The most preferred phosphate is triphenyl phosphate. The combination of triphenyl phosphate with hexabromobenzene and antimony trioxide is also preferred.

Such compounds are also suitable as flame retardants, which contain phosphorus-nitrogen bonds, such as phosphoronitrile chloride, phosphoric acid ester amides, phosphoric acid ester amines, Phos phosphoric acid amides, phosphonic acid amides, phosphinic acid amides, Tris (Azi ridinyl) phosphine oxide or tetrakis (hydroxymethyl) phosphonium chloride. Most of these flame retardant additives are available in the stores.

Other halogen-containing flame retardants are tetrabromobenzene, Hexachlorobenzene and Hexabrombenzene as well as halogenated polystyrenes and polyphenylene ether.

The halogenated described in DE-A-19 46 924 Phthalimides can be used. Of these, in particular N, N'-ethylene bistetrabromophthalimide gained importance.

Other additives include stabilizers and Oxidation inhibitors, heat decomposition agents and cerium settlement by ultraviolet light, lubricants and mold release agents, Dyes, pigments and plasticizers.

Oxidation retarders and heat stabilizers, which the thermo plastic masses can be added according to the invention, are z. B. Group I metal halides of the periods systems, e.g. B. sodium, potassium, lithium halides, optionally in Connection with copper (I) halides, e.g. B. chlorides, bromides or iodides. Furthermore, zinc fluoride and zinc chloride can be used be applied. Also sterically hindered phenols are hydro quinones, substituted representatives of this group and mixtures of these compounds, preferably in concentrations up to 1% by weight, based on the weight of the mixture, can be used.  

Examples of UV stabilizers are various substituted ones Resorcins, salicylates, benzotriazoles and benzophenones, which in the generally used in amounts up to 2 wt .-%.

Materials to increase electromagnetic shielding Waves like metal flakes, powders, fibers, metal coated Fillers can also be used.

Lubricants and mold release agents, usually in quantities up to 1% by weight of the thermoplastic composition are added Stearic acid, stearyl alcohol, stearic acid alkyl esters and amides as well as esters of pentaerythritol with long-chain fatty acids.

Among the additives are also stabilizers, the Zer settlement of the red phosphorus in the presence of moisture and Prevent atmospheric oxygen. Compounds of the Cadmiums, zinc, aluminum, silver, iron, copper, antimony, Tin, magnesium, manganese, vanadium, boron, aluminum and Titans called. Particularly suitable connections are e.g. B. Oxides the metals mentioned, also carbonates or oxicarbonates, Hydroxides and salts of organic or inorganic acids such as Acetates or phosphates or hydrogen phosphates and sulfates.

The thermoplastic molding compositions according to the invention can known processes can be prepared by the Starting components A), B) and C) and optionally further Additives and processing aids D) in the usual mix devices such as screw extruders, preferably twin screw extruders mix and then mix the truder, Brabender mill or Banbury mill extruded. After the extrusion, the extrudate is cooled and crushed.

In order to obtain a molding compound that is as homogeneous as possible, one is inten active mixing advantageous. These are generally medium Mixing times from 0.2 to 30 minutes at temperatures from 230 to 280 ° C required. The mixing order of the components can can be varied, two or possibly three components can be used can be mixed, but all components can also be combined be mixed.

Masses according to the invention can also be obtained by pultrusion be prepared as described in EP-A-56 703 is. The glass fiber strand with the polymer mass is through soaks and then cooled and crushed. The glass fiber length in this case is identical to the length of the granules and is between 3 and 20 mm.  

The thermoplastic molding compositions according to the invention stand out due to its high heat resistance, high rigidity and Toughness. They are suitable for the production of fibers, foils or shaped bodies.

Examples

The following components were used:

Component A)

A styrene / 1,1-diphenylethene copolymer with 30% by weight 1,1-diphenylethene and a weight average molecular weight M _w of 210,000 g / mol was produced according to the examples in WO 95/34586:
A 10-liter metal kettle with a double jacket for cooling and heating and stirrer was inertized for several hours with a refluxing solution of DPE / sec-butyllithium in cyclohexane.

After the cleaning solution had been drained, 5139 ml of cyclohexane and 1173 ml (1200 g; 6.66 mol) of 1,1-diphenylethene were initially charged and titrated with sec-butyllithium until they turned red. Now 50 ml of a 0.32 M sec-butyllithium solution in cyclohexane were added and the reactor contents thermostatted to 70 ° C. 3086 ml (2800 g; 26.89 mol) of styrene were then added in 200 ml steps every 10 minutes. After a reaction time of 180 min, titration was carried out with ethanol until the product was colorless, the polymer was precipitated by dropping the polymer solution into ethanol, and the white powder which had been filtered off and washed several times with ethanol was dried in vacuo (1 mbar) at 200 ° C. for 2 h.
Yield: 3880 g (97%); Styrene content (FTIR): 69.6% (69.8% theor.); DPE content (FTIR): 30.4% (30.2% theor.); Tg (DSC): 142 ° C (width of the glass step: 8 ° C); Molar masses (GPC, polystyrene calibration, g / mol): M _n 115,000, M _w 210,000.

Component B) Component B1)

Continuous glass fibers with a diameter of 10 µm and an amino silane size (glass fiber CS 3540 from PPG).  

Component B2)

Wollastonite with an aminosilane size, bulk density of 0.58 g / ml (according to DIN 53468), grain size d _95% : 13 µm, d _50% : 3.5 µm (Tremin 283/600 AST from the company Quarzwerke).

Component C) Fumaric acid grafted poly (2,6-dimethyl-1,4-phenylene ether)

The following components were intimately mixed in a twin-screw extruder (ZSK 30 from Werner & Pfleiderer) at a melt temperature of 320 ° C. and an average residence time of 3 minutes:
98.5% by weight of poly (2,6-dimethyl-1,4-phenylene ether) with a reduced viscosity η _red of 0.65 (1% in chloroform at 25 ° C.),
1.45% by weight of fumaric acid,
0.05% by weight 3,4-dimethyl-3,4-diphenylhexane.

The degassed melt was extruded as a strand in a water bath dated. The granules obtained were then dried.

Component D)

Hydrogenated styrene-butadiene-styrene triblock copolymer with a styrene content of 32% by weight and a weight-average molecular weight M _w of 180,000 g / mol, as is available under the trade name Kraton® G 1651 from Shell.

Production of molding compounds

Components A), B), C) and D) were shown in Table 1 given proportions by weight in a twin-screw extruder (ZSK 30 from Werner & Pfleiderer) at a temperature of 280 ° C melted, homogenized and extruded as a strand in a water bath dated. The dried granules were then subjected to standard testing bodies splashed.

Measurement methods

The modulus of elasticity and the yield stress were tested on standard test specimens according to ISO 527 certainly.  

The notched impact strength (Charpy) was notched (ak) and notched (an) determined from the impact bending test according to ISO 179.

The molding compounds with glass fiber (Example 1) or wollastonite (Bei game 2) show compared to the pure styrene-1,1-diphenylethene-Co polymers (comparative experiment V1) a significantly higher rigidity and surprisingly a higher toughness, which can be the addition of a rubber (Examples 2 and 4) further increase leaves.

Table 1

Claims (5)

1. Thermoplastic molding compositions containing

• A) 30 to 98% by weight of a copolymer of vinylaromatic monomers and 1,1-diphenylethene or its derivatives optionally substituted on the aromatic rings with alkyl groups having up to 22 C atoms,
• B) 1 to 50% by weight of fibrous or particulate fillers or mixtures thereof,
• C) 1 to 20% by weight of a polymer or polymer mixture modified with polar groups and
• D) 0 to 68% by weight of further additives,

the sum of A), B) and C) being 100% by weight. 2. Thermoplastic molding compositions according to claim 1, characterized records that component C) is a modified polyp contains nylene ether. 3. Thermoplastic molding compositions according to claims 1 and 2, there characterized in that a copolymer of component A) Styrene and 1,1-diphenylethene is used. 4. Use of the thermoplastic molding compositions according to the claims Chen 1 to 3 for the production of films, fibers and molded articles pern. 5. Films, fibers and moldings, available from the thermopla tical molding compositions according to claims 1 to 3.