DE19617068A1 - Molded parts made from thermoplastic molding compounds - Google Patents

Abstract

Mouldings made of thermoplastic moulding masses contain (A) 30 to 99 wt %, relative to the total weight of the moulding mass, of a thermoplastic polymer, comprising, relative to (A): (a1) 50 to 100 wt % of a styrene compound of general formula (I), in which R<1> and R<2> stand for hydrogen or C1-C8 alkyl, or a (C1-C8-alkyl)ester of acrylic or methacrylic acid, or mixtures of the styrene compound and of the (C1-C8-alkyl)ester of acrylic or methacrylic acid; (a2) 0 to 40 wt % acryl nitrile or methacryl nitrile or their mixtures; and (a3) 0 to 40 wt % of one or several other monoethylenically unsaturated monomers different from (a2); (b) 1 to 70 wt %, with respect to the total weight of the moulding mass, of a graft polymer comprising, relative to (B): (b1) 30 to 90 wt % of a rubber-elastic grafted core made of a polymer with a glass transition temperature below 0 DEG C and obtained by copolymerising (b11) 50 to 99.99 wt %, with respect to (b1), of a (C1-C10-alkyl)ester of acrylic acid; (b12) 0.01 to 10 wt % of a polyfunctional, cross-linking monomer; and (b13) 0 to 40 wt % of one or several others monoethylenically unsaturated monomers different from (b11); and (b2) 10 to 70 wt % of a grafted sheath which contains, relative to (b2): (b21) 50 to 100 wt % of a styrene compound of general formula (I), in which R<1> and R<2> stand for hydrogen or C1-C8-alkyl; or a (C1-C8-alkyl)ester of acrylic acid or methacrylic acid; or mixtures of the styrene compound and of the (C1-C8-alkyl)ester of acrylic or methacrylic acid; (b22) 0 to 40 wt % acryl nitrile or methacryl nitrile or their mixtures; and (b23) 0 to 40 wt % of one or several other monoethylenically unsaturated monomers.

Description

Molded parts made from thermoplastic molding compositions, which contain

• A) 30 to 99% by weight, based on the total weight of the molding composition, of a thermoplastic polymer, based on A)
  • a1) 50 to 100 wt .-%, a styrene compound of the general formula in which R¹ and R² are hydrogen or C₁-C₈-alkyl, or
    one (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
    or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid
  • a2) 0 to 40% by weight of acrylonitrile or methacrylonitrile or mixtures thereof, and
  • a3) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers other than a2),
• B) 1 to 70% by weight, based on the total weight of the molding composition, of a graft polymer based on B),
  • b1) 30 to 90% by weight of a rubber-elastic graft core made of a polymer with a glass transition temperature below 0 ° C., obtainable by copolymerization of, based on b1),
    • b11) 50 to 99.99% by weight of a (C₁-C₁₀-alkyl) ester of acrylic acid,
    • b12) 0.01 to 10 wt .-% of a polyfunctional, crosslinking monomer, and
    • b13) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers different from b11), and
  • b2) 10 to 70% by weight of a graft shell, based on b2),
    • b21) 50 to 100 wt .-% of a styrene compound of the general formula in which R¹ and R² are hydrogen or C₁-C₈-alkyl, or
      one (C₁-C₈-alkyl) ester of acrylic acid or meth acrylic acid,
      or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid
    • b22) 0 to 40% by weight of acrylonitrile or methacrylonitrile or mixtures thereof, and
    • b23) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers.

The term "molded parts" in the sense of this invention also includes Semi-finished products (such as pipes, profiles, plates) and foils.

The invention further relates to moldings containing spe zial components A) and B), or additives, and the Use of the molded parts as visual and weather protection parts in construction sector.  

Under "construction sector" here is meant building construction, civil engineering, construction of transportation landscaping and horticulture are understood.

Molded parts made of plastics have a variety of uses, because out of plastics in technically sophisticated processes like that Injection molding process or extrusion and subsequent thermo shape complex geometries or large-area molded parts let real.

When using plastics outdoors, especially in Construction sector, must have sufficient resistance to weather influences, especially UV radiation, frost temperatures, temperature temperature change, water, and chemicals (e.g. cleaning medium). With conjugated polymers Serve, for example polybutadiene rubber, impact-resistant modifi Decorative molding compounds are therefore tough in spite of their good cold impact less suitable for outdoor applications, since the in the Rubber molecules remaining C = C double bonds from UV radiation attack, resulting in weathering of the surface, visible as graying or yellowing and aging due to a deterioration in the mechanical properties, results.

Therefore, in the construction sector, especially for visibility and weather protective parts such as shutters, blinds, panels, canopies, rain gutters, etc., weather-resistant plastics, especially Polyvi nyl chloride (PVC) used. Profiles (e.g. for roller shutters, Panels), pipes and plates usually by extrusion provides, possibly by deformation under the influence of heat (so-called Thermo molding), and with parts made by injection molding are produced, e.g. B. profile end caps, brackets, etc., kom pletted.

PVC points towards other materials such as wood or Aluminum advantages, especially easy care, good Thermal insulation, and rot resistance.

However, it can occur due to weathering and exposure to chemicals lien, e.g. B. cleaning agents, to lighten the PVC. These color changes, also known as "chalking", are based on degradation processes in PVC and are especially in dark staining exercises of PVC disturbing. The chalking also causes an opening roughen the surface and thus loss of gloss. Especially at bright colors interfere with these signs of aging.  

For molded parts that are exposed to higher temperatures, for example Hot water pipes, the low heat resistance proves itself of PVC as a disadvantage.

The production of the above-mentioned, completing injection molded parts (End caps, brackets) made of PVC is difficult because in the PVC Melt an accelerated degradation of the PVC takes place. The as Degraded hydrogen chloride can cause excessive corrosion sion on the processing machines and tools.

Especially for privacy and weather protection components that move who the need (windows, blinds, shutters), is a small Ge important goal. The high compared to other polymers The density of PVC is therefore a disadvantage.

The invention was therefore based on molded parts as a task that Do not have the disadvantages described, in particular with high impact strength, good weather resistance, permanent persistent coloration (high color fastness), high Surface gloss, good heat resistance, and low Ge have importance and can be easily processed by injection molding are.

Accordingly, the molded parts defined at the outset were found. Furthermore, such molded parts were found which determined thermoplastic polymers A) and certain graft polymers B) included. Eventually the use of the Molded parts found as visual and weather protection parts in the construction sector.

Component A) of the molding compositions from which the inventive Molded parts are preferred, with a proportion of 30 to 99 is preferred 35 to 95 and particularly preferably 45 to 80% by weight, based on the sum of components A) and B) contained in the masses.

Component A) is obtained by polymerizing one Monomer mixture based on A),

• a1) 50 to 100, preferably 60 to 95 and particularly preferably 60 to 90% by weight of a styrene compound of the general formula I. in which R¹ and R² are hydrogen or C₁-C₈-alkyl or
  one (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid
  or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
• a2) 0 to 40, preferably 5 to 38 wt .-% acrylonitrile or meth acrylonitrile or mixtures thereof, and
• a3) 0 to 40, preferably 0 to 30% by weight of one or more ren other monoethylenically unsaturated, different from a2) those monomers.

Component A) preferably has a glass transition temperature T _g of 50 ° C. or above. A) is therefore a hard polymer.

As a styrene compound of the general formula (I) (component a1)) preferably styrene, α-methylstyrene and also C₁-C₈-alkyl nuclear alkylated styrenes such as p-methylstyrene or tert.- Butylstyrene, a. Styrene is particularly preferred.

Instead of the styrene compounds or in a mixture with them C₁ to C₈ alkyl esters of acrylic acid and / or methacrylic acid in Consideration, especially those that differ from methanol, ethanol, n- and iso-propanol, sec.-, tert.- and iso-butanol, pentanol, Hexanol, heptanol, octanol, 2-ethylhexanol and n-butanol Ten. Methyl methacrylate is particularly preferred.

Component A) can furthermore be produced at the expense of monomers a1) and a2) one or more further, monoethylenically unsaturated Monomers a3) contain the mechanical and thermal Properties of A) vary within a certain range. As Examples of such comonomers are:

N-substituted maleimides such as N-methyl, N-phenyl and N-cyclo hexyl maleimide;
Acrylic acid, methacrylic acid, further dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and their anhydrides such as maleic anhydride;
Nitrogen-functional monomers such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate, vinylimidazole, vinylpyrrolidone, vinyl caprolactam, vinylcarbazole, vinylaniline, acrylamide and methacrylamide;
aromatic and araliphatic esters of acrylic acid and methacrylic acid, such as phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 2-phenoxyethyl acrylate and 2-phenoxyethyl methacrylate; unsaturated ethers such as vinyl methyl ether,
as well as mixtures of these monomers.

Preferred components A) are, for example:

A / 1: polymethyl methacrylate (PMMA) - in this case A) can be obtained by polymerizing 100% by weight of methyl methacrylate (component a1)),
A / 2: Polymers obtainable by polymerization of 70 to 99, preferably 90 to 99% by weight of methyl methacrylate and 1 to 30, preferably 1 to 10% by weight of styrene, styrene in whole or in part by (C₂- to C₈- Alkyl) esters of acrylic acid or methacrylic acid can be replaced,
A / 3: polymers obtainable by copolymerization of 40 to 90, preferably 50 to 80% by weight of styrene and / or a-methylstyrene a1), with 10 to 60, preferably 20 to 40% by weight of acrylonitrile a2), and optionally 0 to 30, preferably 0 to 20% by weight of further monoethylenically unsaturated monomers a3) different from a2).

If component A) preferably contains styrene and acrylonitrile, see above the well-known commercially available SAN copolymers are created. she usually have a viscosity number VZ (determined from DIN 53 726 at 25 ° C, 0.5 wt .-% in dimethylformamide) from 40 to 160 ml / g, corresponding to an average molecular weight of about 40,000 up to 250000 (weight average).

Component A) can be prepared in a manner known per se, e.g. B. by Substance, solution, suspension, precipitation or emulsion poly receive merisation. Details of these procedures are e.g. B. in Plastic handbook, ed. Vieweg and Daumiller, Carl -Hanser-Verlag Munich, Vol. 1 (1973), pp. 37 to 42 and Vol. 5 (1969), pp. 118 to 130, as well as in Ullmann's encyclopedia of technical chemistry, 4th edition, Verlag Chemie Weinheim, Vol. 19, pp. 107 to 158 "Poly merisation technology ".

Component B) of the molding compositions from which the inventive Molded parts are preferred, with a proportion of 1 to 70 is preferred 5 to 65 and particularly preferably 20 to 55% by weight, based on  the sum of components A) and B) contained in the masses. At this component is a particulate graft copolymer consisting of a rubber-elastic graft core b1) from a polymer with a glass transition temperature below 0 ° C ("Soft component") and a graft grafted onto it shell b2) ("hard component") is constructed.

The graft core b1) is preferred in a proportion of 30 to 90 35 to 80 and particularly preferably 50 to 80 wt .-%, based on component B).

The graft core b1) is obtained by polymerizing a mono mixed mixtures from, based on b1)

• b11) 50 to 99.99, preferably 80 to 99.7 and particularly preferred 85 to 99% by weight of a (C₁-C₁₀-alkyl) ester of acrylic acid,
• b12) 0.01 to 10, preferably 0.3 to 10 and particularly preferably 1 to 4% by weight of a polyfunctional crosslinking mono meren, and
• b13) 0 to 40, preferably 0 to 20% by weight and particularly preferably 0 up to 10% by weight of one or more further mono ethylenically unsaturated monomers other than b11).

Particularly suitable as alkyl acid esters b11) are those which from ethanol, from 2-ethylhexanol and especially from n-butanol deduce. 2-ethylhexyl acrylate and especially n-butyl acrylate are preferred. Mixtures of different acrylics can also be used acid alkyl esters b11) are used, which are in their alkyl differentiate rest.

Crosslinking monomers b12) are bifunctional or polyfunctional comono mere with at least 2 olefinic, non-conjugated double bin formations, for example butadiene and isoprene, divinyl esters of Dicarboxylic acids such as succinic acid and adipic acid, diallyl and divinyl ethers of bifunctional alcohols such as ethylene glycol and butane-1,4-diol, diester of acrylic acid and methacrylic acid with the bifunctional alcohols mentioned, 1,4-divinyl benzene and triallyl cyanurate. Acrylics are particularly preferred acid esters of tricyclodecenyl alcohol of the formula below

known as dihydrodicyclopentadienyl acrylate, as well as the allyl esters of acrylic acid and methacrylic acid.

The other monoethylenically unsaturated monomers b13) which may be present in the graft core b1) at the expense of the monomers b11) and b12) are, for example:
vinyl aromatic monomers such as styrene, styrene derivatives of the general formula

in which R¹ and R² are hydrogen or C₁ to C₈ alkyl;
Acrylonitrile, methacrylonitrile;
C₁ to C₄ alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, ethylhexyl acrylate and the corresponding esters of methacrylic acid; furthermore also the glycidyl esters, glycidyl acrylate and methacrylate;
furthermore the monomers mentioned for component a3);
as well as mixtures of these monomers.

Preferred monomers b13) are styrene, acrylonitrile, methyl meth acrylate, glycidyl acrylate and methacrylate, acrylamide and meth acrylamide.

The determination of the glass transition temperature of the graft core b1) takes place according to the DSC method as described in the publication H. Illers, Makromol. Chemie 127 (1969), pp. 1 ff is.

The graft bowl b2) is in a proportion of 10 to 70 before add 20 to 65 and particularly preferably 20 to 50 wt .-%, based on component B), and is obtained by Polyme risation of a monomer mixture based on b2),

• b21) 50 to 100, preferably 60 to 95 and particularly preferably 60 to 90% by weight of a styrene compound of the general formula in which R¹ and R² are hydrogen or C₁-C₈-alkyl,
  or
  one (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
  or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
• b22) 0 to 40, preferably 0 to 30% by weight of acrylonitrile or meth acrylonitrile or mixtures thereof, and
• b23) 0 to 40, preferably 0 to 20% by weight of one or more ren other monoethylenically unsaturated monomers.

Regarding the monomers b21) and b23), please refer to the explanations refer to components a1) and b13). Accordingly, the Graft shell b2) at the expense of monomers b21) further monomers b22) and / or b23). The graft shell b2) is preferred built up from polymers as preferred execution Form A / 1, A / 2 and A / 3 of component A) were called.

The graft polymers B) are obtained in a manner known per se Lich, preferably by emulsion polymerization at 30 to 80 ° C. Suitable emulsifiers for this purpose are, for example, alkali metal salts of alkyl or alkylarylsulfonic acids, alkyl sulfates, fat alcohol sulfonates, salts of higher fatty acids with 10 to 30 carbons atoms of matter, sulfosuccinates, ether sulfonates or resin soaps. Before the alkali metal salts of alkyl sulfonates are preferably used or fatty acids with 10 to 18 carbon atoms.

So much is preferably used to prepare the dispersion Water that the finished dispersion has a solids content of Has 20 to 50 wt .-%.

Radicals are preferably used as polymerization initiators formers, for example peroxides such as peroxosulfates and Azo compounds such as azo diisobutyronitrile. It can but also redox systems, especially those based on Hydroperoxides such as cumene hydroperoxide can be used. Further you can molecular weight regulator such. B. ethylhexylthioglycolate,  t-Dodecyl mercaptan, terpinols and dimeric α-methylstyrene with use.

To maintain a constant pH value before is preferably 6 to 9, buffer substances such as Use Na₂HPO₄ / NaH₂PO₄ or sodium hydrogen carbonate.

Emulsifiers, initiators, regulators and buffer substances are used in the usual amounts used, so that more details on this spare.

The graft core can particularly preferably also be poly merization of the monomers b1) in the presence of a finely divided Manufacture rubber latex (so-called "seed latex driving style" of the poly merization), as is the case, for example, in DE-A 28 26 925 is written.

In principle, it is also possible to change the graft base after a processes other than that of emulsion polymerization ask, e.g. B. by bulk, suspension or solution poly merization, and the polymers obtained subsequently emulsify. Microsuspension polymerization is also suitable preferably oil-soluble initiators such as lauroyl peroxide and t-butyl perpivalate can be used. The procedures for this are known.

The reaction conditions are preferably adjusted in themselves known manner so that the polymer particles a diameter as uniform as possible d₅₀ (narrow particles size distribution) in the range from 60 to 1000, especially from 80 up to 650 nm.

Instead of a uniform graft polymer B) one can Production of the molded parts according to the invention also various use these polymers B), especially those with clear different particle size. Such acrylic ester polymer Mixtures with a bimodal size distribution offer process technology niche advantages in further processing. Suitable particles diameters range from 60 to 200 nm on the one hand and 300 to 1000 nm on the other hand, see, for example, EP-A 6 503.

The graft cover b2) can be in one or more, for. B. two or three, process steps are produced. You can the monomers b21), b23) individually or as a mixture with one another Polymerization reactor are added. The monomer ratio in the mixture can be constant over time or a gradient. Combinations of these procedures are also possible. The  Gross composition remains from the mentioned configurations unaffected by the procedure.

Graft polymers with several are also suitable "soft" and "hard" levels, e.g. B. structure b1) -b2) -b1) -b2) or b2) -b1) -b2), especially in the case of larger particles.

Larger graft particles B) can preferably also be combined in one produce two-stage process, such as in the DE-A 24 27 960, example 3 on columns 9 to 10, is described. Initially, emulsion polymeri sation produced a small-sized graft polymer, after which the polymer obtained by adding an agglomeration is agglomerated by means of particles of larger diameter.

Some preferred graft polymers B) are listed below leads, the particle diameter is the weight average d₅₀.

B / 1:
60% by weight of a graft core b1)

• b11) 98% by weight of n-butyl acrylate
• b12) 2% by weight dihydrodicyclopentadienyl acrylate
  40% by weight of a graft shell b2)
• b21) 75% by weight of styrene
• b22) 25% by weight of acrylonitrile
  Particle diameter about 200 nm

B / 2:
60% by weight of a graft core b1) as in B / 1
40% by weight of a graft shell b2) as in B / 1
Particle diameter about 400 nm

B / 3:
60% by weight of a graft core b1) as in B / 1
15% by weight of a first graft shell b2) made of styrene
25% by weight of a second graft shell b2) as in B / 1
Particle diameter about 500 nm

So far in the grafting not grafted polymers from the mono meren b2) arise, these quantities are usually below 10% by weight of b2) are assigned to the mass of component B).

Component B) is rubber-elastic and serves the impact tough modification of the hard matrix polymer A). Exists at for example the matrix A) made of a polymer based on styrene / Acrylonitrile, so-called SAN polymer (preferred component A / 3) and that Graft polymer B) from an alkyl acrylate graft core b1) and a graft cover b2) based on styrene / acrylonitrile, so you get  which is known to the person skilled in the art as ASA (acrylonitrile / styrene / acrylic ester) molding compounds.

In addition to components A) and B), the thermoplastic Molding compositions from which the molded parts according to the invention are produced are common additives such as lubricants and mold release agents, Waxes, pigments, dyes, flame retardants, antioxidants, Stabilizers against exposure to light, fibrous and powdery Fillers and reinforcing agents and antistatic agents in the for them Contain the usual amounts. As a rule, the proportion is of the total additives 0.1 to 20 wt .-%, preferably 0.5 to 15% by weight, based on the sum of components A) and B).

The dyes and / or used to color the molded parts Pigments are known to the person skilled in the art. Examples of common ones Pigments or dyes are titanium dioxide, chalk, carbon black, pigment yellow 164 (C.I. 77899), pigment brown 29 (C.I. 77500), pigment brown 24 (C.I. 77310).

To stabilize the molded parts against exposure to light So-called UV stabilizers are used, for example substi acted resorcinols, salicylates, benzotriazoles, benzophenones and HALS (Hindered Amine Light Stabilizer) and the like. they are e.g. B. under the trade names Topanol®, Irganox® and Tinuvin® im Trade.

The proportion of dyes and / or pigments is usually 0.01 to 15, preferably 0.1 to 10 wt .-%, and the proportion of Sta bilisators against exposure to light 0.1 to 5, especially 0.2 to 1% by weight, based in each case on the mixture of A) and B).

The molding compositions can be produced according to a mixture known per se procedures take place, for example by incorporating the graft polymer B) in the thermoplastic polymer A) at tem temperatures above the melting point of A), especially at Temperatures from 150 to 350 ° C, in an extruder, Banbury-Mi shearers, kneaders, roller mills or calenders. The components can but can also be mixed "cold" without melting and the powder mixture or consisting of granules is only at the Processing melted and homogenized.

The molding compounds are added using the generally customary processes processed the moldings of the invention. Be exemplary extrusion (for pipes, profiles, fibers, foils and sheets) injection molding (for all types of molded parts, in particular also  those with complicated geometries), as well as calendering and called rolling (for plates and foil).

The molding compositions described are particularly suitable Manufactured molded parts for use outdoors, especially in Construction sector, and there especially as visual and weather protection parts.

Examples of such molded parts are roller shutters, blinds, panels, Canopies, gutters, sun protection slats, and similar construction parts.

The moldings according to the invention have good weathering properties good impact resistance, long-term resistance Coloring, high surface gloss and good heat resistance on. They are light in weight and can be easily placed in Process injection molding, and have good recycling properties on.

Examples

The average particle size d is given to the weight average particle size as determined by means of a analytical ultracentrifuge according to the method of W. Scholtan and H. Lange, Kolloid-Z. and Z.-Polymer 250 (1972) Pages 782 to 796. The ultracentrifuge measurement provides the integral mass distribution of the particle diameter a sample. From this it can be seen what percentage by weight the particles have a diameter equal to or smaller than one size.

The d₁₀ value indicates that particle diameter at which 10% by weight of all particles a smaller and 90% by weight one have a larger diameter. Conversely, for the d₉₀ value that 90% by weight of all particles a smaller and 10% by weight one have a larger diameter than the diameter that the d₉₀ value corresponds. The weight average particle diameter d₅₀ or volume average particle diameter D₅₀ gives those Particle diameter at which 50 wt .-% or vol .-% of all part Chen a larger and 50 wt .-% or Vol .-% a smaller Have particle diameter. d₁₀-, d₅₀- and d₉₀-value character the width Q of the particle size distribution, where Q = (d₉₀-d₁₀) / d₅₀. The smaller Q is, the narrower the distribution.

The following components were produced (all percentages are % By weight).  

Production of a component A) Copolymer of styrene and acrylonitrile

A copolymer of 65% by weight styrene and 35% by weight Acrylonitrile (for component A-1) or from 70 wt .-% a-methyl styrene and 30 wt .-% acrylonitrile (for component A-2) after Method of continuous solution polymerization produced, as in the plastics manual, ed. R. Vieweg and G. Daumiller, Vol. V "Polystyrene", Carl Hanser Verlag Munich 1969, page 122 to 124. The viscosity number VZ (determined from DIN 53 726 at 25 ° C, 0.5 wt .-% in dimethylformamide) was 80 ml / g for component A-1 and 58 ml / g for component A-2.

Preparation of a component B-1

Particulate graft polymer of small diameter made of ver wetted poly-n-butyl acrylate (core) / styrene-acrylonitrile copolymer (Bowl).

16 g of butyl acrylate and 0.4 g tricyclodecenyl acrylate in 150 g water with the addition of 1 g the sodium salt of a C₁₂-C₁₈ paraffin sulfonic acid, 0.3 g of potassium persulfate, 0.3 g sodium hydrogen carbonate and 0.15 g sodium pyro phosphate heated to 60 ° C with stirring. 10 minutes after The polymerization reaction started within 3 hours a mixture of 82 g butyl acrylate and 1.6 g tricyclo decenyl acrylate added. After the monomer addition was complete you react for an hour. The latex obtained had a solids content of 40% and an average particle size d₅₀ determined from 76 nm. The particle size distribution was narrow (Quotient Q = 0.29).

150 g of the polybutyl acrylate latex obtained were mixed with 40 g of a Mixture of styrene and acrylonitrile (weight ratio 75:25) and 60 g of water mixed and stirring with the addition of white teren 0.03 g of potassium persulfate and 0.05 g of laroyl peroxide for 4 hours heated to 65 ° C. After completion of the graft copolymerization was the polymerization product using calcium chloride solution 95 ° C precipitated from the dispersion, washed with water and was in the air flow dried. The degree of grafting of the graft mixed poly merisats was 35%.

Preparation of a component B-2

Particulate graft polymer of large diameter made of ver wetted poly-n-butyl acrylate (core) / styrene-acrylonitrile copolymer (Bowl).  

To a mixture of 5 g of the seed latex described under B-1, 100 g of water and 0.2 g of potassium persulfate were removed in the course of 3 hours at 60 ° C a mixture of 98 g of n-butyl acrylate and 2 g Dihydrodicyclopentadienyl acrylate and a solution separately of 1 g of Na-C₁₂-C₁₈ paraffin sulfonate in 50 g of water. The Polymerization was then continued for 2 hours. Of the average particle diameter d₅₀ of the resulting latex was 288 nm with narrow distribution of particle size (Q = 0.1), the Solids content of the latex was 40%.

150 g of this latex were mixed with 40 g of a mixture of styrene and Acrylonitrile (weight ratio 75:25) and 110 g water mixed and with stirring after the addition of a further 0.03 g of potassium persulfate and 0.05 g lauroyl peroxide heated to 65 ° C for 4 hours. That at the Graft copolymerization polymerization product obtained then using a calcium chloride solution at 95 ° C from the Disper precipitated, separated, washed with water and warm Airflow dried. The degree of grafting of the graft copolymer was found to be 27%.

Preparation of a component B-3

Particulate graft polymer of large diameter made of ver wetted poly-n-butyl acylate (core) / polystyrene (shell) / styrene Acrylonitrile copolymer (shell).

To a mixture of 3 g of the seed latex described under B-1, 100 g of water and 0.2 g of potassium persulfate were removed in the course of 4 hours at 60 ° C a mixture of 98 g of n-butyl acrylate and 2 g Dihydrodicyclopentadienyl acrylate and a solution separately of 1 g of Na-C₁₂-C₁₈ paraffin sulfonate in 50 g of water. The Polymerization was then continued for 2 hours. Of the average particle diameter d₅₀ of the resulting latex was 430 nm with a narrow distribution of particle size (Q = 0.1), the Solids content was 40%.

150 g of this latex were mixed with 60 g of water, 0.03 g of potassium persulfate and 0.05 g of lauroyl peroxide are mixed, after which the latex particles in the course of 3 hours at 65 ° C. first 15 g of styrene and then a mixture of 18.75 g of styrene over the course of a further 4 hours and 6.25 g of acrylonitrile were grafted on. Then was the polymer with a calcium chloride solution at 95 ° C. falls, separated, washed with water and in a warm air stream dried. The degree of grafting of the polymer was 35% and Particles had an average diameter d₅₀ of 510 nm.  

Components B) are therefore conventional ches ASA polymer with different particle sizes.

The polymer A *) used in the comparative examples was a Polyvinyl chloride PVC, which is highly impact-resistant with polyacrylic ester is infected (Vinidur® SZ 6465, BASF)

Additives

The numbers correspond to the abbreviations used in the tables.

The following were used in the ASA molding compounds:
1: Diisodecyl phthalate
2: 2- (2H-benzotriazol-2-yl) -4-methylphenol (Tinuvin® P, from Ci ba-Geigy)
3: bis (2,2,6,6-tetramethyl-4-piperidyl) sebazate (Tinuvin® 770, from Ciba-Geigy)
4: Pigment White 6 (Kronos 2220, Kronos)
5: Pigment Red 101 (Bayferrox® 140M, Bayer)
6: Pigment Black 7 (carbon black Printex® 75, from Degussa)
7: Pigment Brown 24 (Sicotan® yellow K 2111, from BASF)

The following were used in the PVC molding compounds:
8: Acrylic acid ester-methacrylic acid ester copolymer (Vinuran® 3833, from BASF)
9: Pb stabilizer with acrylic flow aid and external and internal flow aids (Bäropan® R 2930 FPI, Bärlocher)
10: Organophosphite compound (Bärostab® CWM 201, Bärlocher)
11: Ca / Zn stabilizer (Bäropan® MC 8222 FP, Bärlocher)
12: Glycerol monofatty acid ester (C₁₄-C₁₈) (Bärolub® LCD, Bärlocher)
13: hydrocarbon wax (Bärolub® LKO, Bärlocher)
14: chalk (Hydrocarb® 95T, Omya)
15: Pigment brown 29 (CI 77500) (Sicopal® brown K 2795, from BASF)
16: carbon black (Printex® 75, Degussa)
17: Pigment yellow 164 (CI 77899) (Sicotan® brown K 2711, from BASF)
18: Titanium dioxide (Kronos 2220, Kronos).

Production of the blends and the moldings

Components A) and B) were in a conventional extruder, Type ZSK 30, Werner and Pfleiderer, intimately mixed at 280 ° C, extruded and granulated. The polymer obtained was then eats in a mixing extruder, type ZSK30 from Werner and Pfleiderer, intimately mixed with the additives at 280 ° C, ex trudged and granulated. The data given in Table 1 were obtained Compositions. Press plates of 5 × were made from the granules 4 cm.

The mixtures of the comparative examples consisting of PVC were manufactured in which the components specified in Tab. 2 in have been intimately mixed in a high-speed mixer. The maxi Male mixing temperature was 220 ° C. The mixtures were then Continue processing at 180 ° C on a roller mill to form rolled skins processed, from which plates of 5 × 4 cm were pressed at 180 ° C.

Table 1

Composition [parts by weight of the ASA molding compositions

Table 2

Composition [parts by weight] of the PVC molding compounds

Examination of the moldings

The press plates were made by one of the following methods weathered.

Method A: Weathering in a Weather-o-Meter device type CI35A from Atlas, according to standard SAE 1960: 40 min day, 20 min day with rain, 60 min day, 60 min night; Black panel temperature approx. 70 ° C; Soon run.

Method B: Weathering in the Xenotest device type 1200 CPS Heraeus, according to DIN 53387: 102 min dry, 18 min moist; Blackboard temperature 65 ° C; Synchronism.

To assess the color stability during weathering, the Boards visually assessed before weathering, 500 h using method A or B weathered and visually assessed again. In Table 3 means + no or little color change, o means moderate, - means strong and - - very strong color change, each related to the condition before weathering.  

In order to assess the surface gloss after weathering, the panels before and after 500 h of weathering a gloss subjected to measurement. A Byk-Gardner device was used a measuring angle of 60 ° C. Tab. 3 shows the gloss after weathering in%, based on the gloss of the panel before weathering (= 100%) specified.

The stability against graying and chalking was as follows average: the plates were, according to visual assessment, 200 h weathered according to method A or B, and then 2 min in one 85 ° C hot aqueous detergent solution ("Rinse and universal clean gmittel "from Fa. Chemie-Vertrieb, Hanover) of concentration 0.2 vol .-% immersed. After rinsing with distilled water and Drying in a stream of air was again visually assessed Splits. In Table 3 + means no or little graying / chalking, - means severe graying / chalking, in each case related to the Condition before weathering and contact with soap solution.

The heat resistance was called the Vicat softening temperature (150 306) determined with measurement method B.

Tab. 3 summarizes the test results.

The table shows that the moldings according to the invention from ASA a much better color stability when weathered like this like a more permanent surface gloss than PVC molded parts point.

Especially when comparing identical colors,
white: attempts 1 and 3 vs. Trial 3V,
brown: experiment 2 vs. Trial 2V,
dark brown: experiments 4 and 5 vs. Experiment IV,
gray: experiment 6 vs. Trial 4V
shows the better weather resistance of the molded parts according to the invention made of ASA.

Resistance to weathering (stability to ver gray / chalking) of the ASA molded parts, especially for dark colors, is higher than that of molded parts made of PVC, as the behavior towards detergent solution shows.

Finally, molded parts made of ASA according to the invention are better warm dimensionally stable and lighter than PVC.

Claims (8)

1. Molded parts, made of thermoplastic molding compositions, which contain che

• A) 30 to 99% by weight, based on the total weight of the molding composition, of a thermoplastic polymer, based on A)
  • a1) 50 to 100 wt .-%, a styrene compound of the general formula in which R¹ and R² are hydrogen or C₁-C₈-alkyl, or
    one (C₁-C₈-alkyl) ester of acrylic acid or meth acrylic acid,
    or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
  • a2) 0 to 40% by weight of acrylonitrile or methacrylonitrile or mixtures thereof, and
  • a3) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers different from a2),
• B) 1 to 70% by weight, based on the total weight of the molding composition, of a graft polymer, based on B),
  • b1) 30 to 90% by weight of a rubber-elastic graft core made of a polymer with a glass transition temperature below 0 ° C., obtainable by copolymerization of, based on b1),
    • b11) 50 to 99.99% by weight of a (C₁-C₁₀-alkyl) ester of acrylic acid,
    • b12) 0.01 to 10 wt .-% of a polyfunctional, crosslinking monomer, and
    • b13) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers different from b11), and
  • b2) 10 to 70% by weight of a graft shell, based on b2),
    • b21) 50 to 100% by weight of a styrene compound of the general formula in which R¹ and R² are hydrogen or C₁-C₈-alkyl, or
      one (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
      or mixtures of the styrene compound and the (C₁-C₈-alkyl) ester of acrylic acid or methacrylic acid,
    • b22) 0 to 40% by weight of acrylonitrile or methacrylonitrile or their mixtures or their mixtures, and
    • b23) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers.

2. Molded parts produced from thermoplastic molding compositions according to claim 1, in which the thermoplastic polymer A) from, based on A),

• a1) 50 to 80% by weight of styrene or a-methylstyrene or mixtures thereof,
• a2) 20 to 40% by weight of acrylonitrile, and
• a3) 0 to 20% by weight of one or more further monoethylenically unsaturated monomers

consists. 3. moldings made from thermoplastic molding compositions according to claims 1 or 2, in which the graft polymer B) from, based on B),

• b1) 30 to 90% by weight of a rubber-elastic graft core made of a polymer with a glass transition temperature below -20 ° C., obtainable by copolymerization of, based on b1),
  • b11) 80 to 99.9% by weight of n-butyl acrylate or ethylhexyl acrylate or mixtures thereof,
  • b12) 0.1 to 4% by weight of dihydrodicyclopentadienyl acrylate,
  • b13) 0 to 10% by weight of one or more further monoethylenically unsaturated monomers different from b31), and
• b2) 10 to 70% by weight of a graft shell, based on b2),
  • b21) 50 to 80% by weight, styrene or a-methylstyrene or mixtures thereof,
  • b22) 20 to 40% by weight of acrylonitrile,
  • b23) 0 to 20% by weight of one or more further ethylenically unsaturated monomers,
    or
  • b24) 80 to 100% by weight, methyl methacrylate,
  • b25) 0 to 20% by weight of one or more further monoethylenically unsaturated monomers.

4. Molded parts made from thermoplastic molding compounds Claims 1 to 3, in which the molding compositions are customary contain substitutes.   5. Molded parts made from thermoplastic molding compounds Claim 4, in which pigments or dyes or their Mixtures are included as additives. 6. Molded parts made from thermoplastic molding materials Claim 4, in which stabilizers against exposure to light as Additives are included. 7. Use of molded parts according to claims 1 to 6 as Visual and weather protection parts in the construction sector.