DE4208340A1 - Polyarylene ether] moulding materials with improved surface quality - contg polyarylene ether] and acrylate] graft rubber with bi:modal particle size distribution - Google Patents

Abstract

Thermoplastic moulding materials (I) are claimed, contg. (A) 70-98 wt.% polyarylene ether and (B) 2-30 wt.% acrylate graft rubber with bimodal particle size distribution. (A) has repeating units of formula -(Phe-SO2-Phe-O)- (III) and/or -(Phe-CMe2-Phe-O-Phe-SO2-Phe-O0- (IV) (with Phe = 1,4-phenylene). (B) is a graft copolymer rubber with a crosslinked base polymer derived from 1-10C alkyl (meth)acrylates and up to 25 wt.% styrene, alpha-methylstyrene, butadiene and/or (meth)acrylonitrile, and a grafted sheath obtd. from 1-4C methacrylates, styrene and/or (meth)acrylonitrile. USE/ADVANTAGE - Used for the prodn. of fibres, film and moulded prods. (claimed). Also claimed are moulded prods. obtd. from (I). Mouldings produced from (I) have high thermal dimensional stability, good weathering resistance and excellent notched impact strength, combined with good surface quality.

Description

The present invention relates to thermoplastic mold masses, containing as essential components

• A) 70-98 wt .-%, based on the total weight of the Components A) -B), polyarylene ether
• B) 2-30 wt .-%, based on the total weight of the components ten A) -B), an acrylate graft rubber with bimodal Particle size distribution.

The invention also relates to the use of such Molding compounds for the production of moldings and the so he retaining molded body.

Polyarylene ethers are characterized by excellent heat dimensional stability and good chemical resistance out; however, the impact resistance is good for some applications properties not sufficient.

DE-A 17 19 244 describes that the addition of Acrylic rubbers in small amounts to polyarylene ethers Improvement in impact strength. Used one as an impact modifier with styrene / acrylonitrile mixtures grafted butadiene rubbers, such as in US-A 35 55 119 and described in EP-A 3 75 961, the products indeed good impact strength, especially at low temperatures on, but leave the weather resistance and warmth dimensional stability left something to be desired.

This disadvantage can be overcome by using acrylate Overcoming graft rubber - as from DE-A 21 61 120 the better compared to diene rubbers Weather and oxidation resistance even in mixtures with polyaryl ethers to wear.  

The present invention was based, thermo plastic molding compounds based on polyarylene ethers To provide that in addition to good toughness properties also have a good surface finish have produced moldings.

This object is achieved by the thermoplastic molding compositions according to claim 1 solved. Before Drawn molding compositions of this type can be found in the subclaims to take.

The molding compositions according to the invention contain as component A) 70-98, preferably 75 to 95 and particularly preferred 80-95% by weight of a polyarylene ether.

Suitable polyarylene ethers are known per se and in the Li temperature, for example GB-A 11 52 035, US-A 41 75 175, US-A 40 08 203 and US-A 48 70 153.

In general, suitable polyarylene ethers have recurring ones units

- [O-E-O-E ′] -

where E is for the remainder of an aromatic dihydroxy compound HO-E-OH and E 'for the rest of an aromatic dihalogen connection Hal-E′-Hal stand.

Preferred dihydroxy compounds have the formula I.

where X -SO ₂ -, -O-, -S-, -C = O-, -N = N-, -C (Ra) = C (R ^b ) -, <S = O, a chemical bond or < CRR ′ is
Ra and R ^b independently of one another are hydrogen atoms or C ₁ -C ₆ -alkyl groups,
R and R ′ independently of one another represent hydrogen atoms, C ₁ -C ₆ -alkyl groups, C ₁ -C ₆ -alkoxy groups, C ₆ -C ₁₂ -aryl groups or chlorine- or fluorine-substituted derivatives of the above groups,
R ¹ and R ^{2 can} independently have the same meaning as R and R 'and
a and b is an integer from 0 to 4, preferably 0, 1 or 2, and
p is 0, 1 or 2, preferably 1.

Aromatic dihydroxy compounds are particularly preferred 2,2′-di- (4-hydroxyphenyl) propane, (bisphenol A), 3,3 ', 5,5'-tetramethyl-2,2-di- (4-hydroxyphenyl) propane (tetra methylbisphenol A), 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxydiphenyl, which can also be used in any mixture can be used.

Other suitable dihydroxy compounds are, for example described in DE-A 37 42 264, to which reference is made here be.

Preferred dihalogen compounds have the formula II

where R ³ to R ^{6 have} the same meaning as R ¹ and R ² , Q, Z and W can independently represent the groups mentioned for X, and q and r each have the value 0, 1 or 2, preferably 0 or 1 . Y ¹ and Y ² are each Cl or F.

A list of suitable dihalogen compounds is e.g. B. described in DE-A 37 42 264, to which reference is made here be.  

Dihalogen compounds are particularly preferred 4,4'-dichlorodiphenyl sulfone and 4,4'-dichlorobenzophenone.

From the above, it follows that particularly preferred polyarylene ether repeating units

and or

to have.

Corresponding products are under the names Vic trex® PES, Udel® or Ultrason® commercially available.

The polyarylene ethers can also have a block structure, as described in DE-A 37 42 264.

Suitable process conditions for the synthesis of polyarylene ethers in general are for example in the EP-A-1 13 112 and EP-A-1 35 130.

The conversion of the monomers into is particularly suitable aprotic polar solvents in the presence of water free alkali carbonate. A particularly preferred combination is N-methylpyrrolidone as solvent and potassium carbonate as a catalyst or the reaction in the melt.

The molecular weight of suitable polyarylene ethers is in all generally in the range of 1500-60,000 g / mol (weight average value).  

Polyarylene ether segments can also be used in copolymers Structural units of polyamides, polyesters, aromatic Polycarbonates or polyester carbonates, polysiloxanes, Polyimides or polyetherimides are present, the molecular weight weights of the block or graft arms in the copolymers are generally in the range of 1000-30000 g / mol, the blocks of different structure can be in the Copolymers can be arranged alternately or statistically. The weight fraction of the polyarylene ether segments in such Copolymers should be 3-97, preferably 10-90 and in particular which are 20-80% by weight. Methods for the synthesis of such Copolymers are available from A. Noshay et. al., block copolymers, Academic Press, 1977.

The molding compositions according to the invention contain as component B. 2-30, preferably 5-25 and in particular 5-20 wt .-%, bezo to the total weight of components A) -B) of an acrylic Lat graft rubber with bimodal particle size distribution. In general, suitable components B) have a network te graft base and at least one graft shell.

Such graft products are generally manufactured by emulsion polymerization; suitable procedures are e.g. B. in US-A 38 08 180, US-A 38 43 753 and for more scha lig rubbers described in US-A 35 62 235.

C ₁ -C ₁₀ -alkyl esters of (meth) acrylic acid are preferably used for the graft base, optionally together with up to 25% by weight of other comonomers such as styrene, acrylonitrile or butadiene. C ₂ -C ₈ -Alkyl acrylates, in particular ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate and methyl methacrylate are particularly preferred as preferred esters of methacrylic acid.

To link the graft base, polyfunctional ones are used Monomers with at least two olefinic, non-conjugated ten double bonds used. Diacrylates are preferred, Divinylbenzenes, allyl acrylates, diacrylamides and phosphoric acid retriallyl esters, generally in amounts of 0.1-4, preferably from 0.2 to 3 wt .-%, based on the total Ge importance of the monomers of the graft base.  

Examples of crosslinkers are divinylbenzene and diallyl maleate, diallyl fumarate, diallyl phthalate, triallyl cyanurate, Triallyl isocyanurate and ethylene glycol dimethacrylate as well Mixtures of the same called.

Preferred components B) have a glass transition temperature temperature below 10 ° C and a gel content of more than 60, preferably more than 70% by weight (determined according to H. Hoff mann et al., polymer analysis, Georg-Thieme Verlag, Stutt gart 1977).

C ₁ -C ₄ (meth) acrylates, styrene, α-methylstyrene and (meth) acrylonitrile are preferably used as monomers for the graft shell, mixtures of C ₁ -C ₄ methacrylates and styrene or C ₁ -C ₄ methacrylates alone are particularly preferred. In particular, methyl methacrylate / styrene mixtures with preferably at least 75% by weight of methyl methacrylate may be mentioned.

The weight ratio of the graft base to the graft shell is generally in the range of 25:75 to 75:25 preferably 30: 70 to 70: 30.

The average particle size (d ₅₀ ) of the acrylate graft rubber B) is generally in the range from 100 to 700, preferably from 150 to 500 nm.

In addition, component B) has a bimodal particle size distribution, as can be obtained by mixing acrylate graft rubbers with different particle sizes d ₅₀ or by suitable polymerization control (partial agglomeration). Appropriate methods are known to the person skilled in the art.

Bimodal particle size distribution here means that the (e.g. determined using analytical ultracentrifuge) diffe profitable mass distribution of the particle diameter two Ma xima (cf. W. Scholtan, H. Lange, Kolloid-Z. and Z. Polymers, 250 (1972, 782-796).

Both single-shell are suitable for the purposes of the invention as well as multi-layered (i.e. with more than one graft shell) Graft rubbers. In the case of multi-layer graft rubbers  the outer shell advantageously has a glass transition temperature temperature above 50 ° C.

The molding compositions according to the invention can be used as component C. 0-60, preferably 2-45 and in particular 5-40% by weight fibrous or particulate fillers or mixtures thereof contain.

As reinforcing fillers are, for example, As best, coal and preferably called glass fibers, the Glass fibers e.g. B. in the form of glass fabrics, mats, nonwovens and / or preferably glass silk rovings or cut Glass silk made of low-alkali E-glasses with a diameter of 5 to 20 µm, preferably 8 to 15 µm, for use long, which after their incorporation have a medium length of 0.05 to 1 mm, preferably 0.1 to 0.5 mm.

Also wollastonite, calcium carbonate, glass balls, quartz powder and Boron nitride or mixtures of these fillers can be used.

In addition to components A) to C) and possibly D), the Molding compositions according to the invention 0-40, preferably up to 30 wt .-%, based on the total weight of the molding compositions contain additives and processing aids. Flame retardants, UV stabilizers are just one example called sators or pigments, as the expert for the like molding compounds are known.

The thermoplastic molding compositions according to the invention can are produced by methods known per se by the starting components in conventional mixing devices such as screw extruders, preferably twin-screw extruders, Brabender mills or Banbury mills and kneaders mixes and then extruded. After extrusion, it will Extrudate cooled and chopped.

In order to obtain a molding compound that is as homogeneous as possible, one is intensive mixing advantageous. In general mean mixing times of 0.2 to 30 minutes for one Temperature from 280 to 350 ° C applied.  

The order of mixing the components can vary 2 components can be premixed if necessary However, all components can also be mixed together.

The molding compositions according to the invention are notable for high Heat resistance, good weather resistance as well Outstanding impact strength from molded articles made from the molding compositions according to the invention are produced good surfaces.

Because of their high heat resistance and good mecha African properties are suitable Molding compositions for the production of molded parts, in particular for electrical and electronic device components, as well as for the Vehicle interior.

Examples Component A ₁ )

Polyarylene ether of the basic structure according to formula IV, cha characterized by a viscosity number VZ of 64 ml / g, ge measure 1% by weight in pheny1 / 1,2-dichlorobenzene 1: 1 (weight Ratio).

Component A ₂ )

Polyaryl ethers of the basic structure corresponding to formula III, characterized by a VZ of 59 ml / g, measured 1-% in Phenol / 1,2-dichlorobenzene 1: 1.

Component B ₁ )

Graft polymer made from a cross-linked n-butyl acrylate rubber base and a graft shell made from methyl methacrylate with an average particle size (d ₅₀ ) of 450 nm and a rubber content of 60% by weight. As the crosslinking agent, the graft base contained 2% by weight, based on the total weight of the graft base, of ethylene glycol dimethacrylate.

Component B₂)

Structure as B ₁ ), particle size d ₅₀ 200 nm and rubber content (graft base) 50 wt .-%.

Component B ₃ )

Multi-stage graft polymer with a cross-linked polymethyl methacrylate (PMMA) core and an outer PMMA shell with an average particle size (d ₅₀ ) of 200 nm. The soft phase consisted of 78% by weight of n-butyl acrylate, 18% by weight of styrene and 4% by weight crosslinker (ethylene glycol dimethacrylate). The weight ratio of hard phase to soft phase was 35:65.

Component B ₄ )

Structure like B ₃ ) with ad ₅₀ of 500 nm.

Production of molding compounds

The components A) and B) according to Tables 1 and 2 were in a twin-screw extruder at a melt temperature of 300 mixed up to 340 ° C. The melt was through a water bath directed and granulated.

The dried granules became round at 310 to 330 ° C slices and standard small bars processed.

The Vicat softening temperature was according to DIN 53 460, with a force of 49.05 N and a temperature increase of 50 K per hour, determined on standard small bars.  

The notched impact strength a _k (DIN 53 453) was determined at 23 ° C.

The surface of the molded parts was qualified on circular discs assessed and divided into 3 classes: good (g), with tel (m) and bad (s).

The composition of the molding compounds and the results of the Measurements can be found in Tables 1 and 2.

Table 1

Table 2

As the examples show, the invention stands out modern molding compounds due to high heat resistance and excellent toughness from the surfaces of the judged The molded articles are of good quality.

Claims (5)

1. Thermoplastic molding compositions containing as essential components

• A) 70-98 wt .-%, based on the total weight of components A) -B), polyarylene ether
• B) 2-30% by weight, based on the total weight of components A) -B) of an acrylate graft rubber with a bimodal particle size distribution.

2. Thermoplastic molding compositions according to claim 1, containing as component A a polyarylene ether with repeating units of the formulas and or 3. Thermoplastic molding compositions according to at least one of claims 1 to 2, containing as component B) a graft rubber with a crosslinked graft base of C ₁ -C ₁₀ alkyl esters of (meth) acrylic acid and up to 25% by weight comonomers from the group styrene , α-methyl styrene, butadiene, (meth) acrylonitrile and a graft shell made of C ₁ -C ₄ methacrylates, styrene or (meth) acrylonitrile or the mixtures. 4. Use of the thermoplastic molding compositions according to Claims 1 to 3 for the production of fibers, films and moldings. 5. Moldings made of thermoplastic molding compositions according to the Claims 1 to 3.