DE19846252A1 - Housings of small transformers containing electrical devices - Google Patents

Abstract

The invention relates to the utilization of a shaped thermoplastic material different from ABS for the production of housings and the semi-finished products thereof for electrical devices containing small transformers, containing, in relation to the sum of the portions of components A, B and C and optionally D, a total of 100 % by weight of a: 1-48 % by weight of a single or multiphase particulate emulsion polymer with a glass transition temperature below O DEG C in at least one phase and a mean particle size of 50-1000 nm, preferably 50-800 nm as component A; b: 1-48 % by weight of at least one amorphous or semi-crystalline polymer as component B; c: 51-98 % by weight of a polycarbonate as component C and d: 0-47 % by weight of usual additives and/or fibrous or particulate filling materials or the mixtures thereof as component D.

Description

The invention relates to housings of small transformers containing electronics tro devices. In particular, the invention relates to such housings at the same time good dimensional stability, great stability, good chemical resistance and good Resistance to yellowing.

For the manufacture of housings for small transformers, such as for Nieder Power supplies of small electrical devices have so far been made of different materials used. Fire resistant polyamide, for example, has the contained black colored fire retardants only an extremely limited Color selection on. The housings also tend to shrink and warp. In moist environment there is a high tendency to water absorption, leading to Leads to dimensional changes. In addition, the housings are susceptible to yellowing.

Polypropylene housings tend to shrink and warp. Beyond that the heat resistance is low.

ABS (acrylonitrile / butadiene / styrene) polymers show through the crosslinking of Butadiene units have a tendency to embrittlement and yellowing. ABS is also not always sufficiently resistant to cleaning agents and disinfectants.

The use of ASA (acrylate / styrene / acrynitrile) molding compounds with a low  Polycarbonate content leads to housings with insufficient scratch resistance and not always satisfactory swelling behavior. The color depth is too not always sufficient. Such housings are in DE-A-196 30 120 described.

The object of the present invention is therefore to housing Kleintrans Provide electrical devices containing formers that are stable and chemi are resistant to kali and do not yellow. They should also be scratch-resistant and one have good dimensional stability. The UV and heat aging resistance is said to be high be so that the surface gloss is retained. Other requirements are good recyclability and poor fire behavior as well as good Dimensional accuracy with thermal stress during manufacture and application.

According to the invention, these objects are achieved by using a thermoplastic molding composition different from ABS, comprising, based on the sum of the amounts of components A, B, C and, if appropriate, D, which gives a total of 100% by weight,

• 1. a: 1-48 wt .-% of at least one single or multi-phase particulate emulsion polymer with a glass over transition temperature below 0 ° C in at least one phase and an average particle size of 50-1000 nm as component A,
• 2. b: 1-48% by weight of at least one amorphous or partially crystalline Polymer as component B,
• 3. c: 51-98% by weight of polycarbonates as component C, and
• 4. d: 0-47% by weight of conventional additives and / or fibrous or particulate  Fillers or their mixtures as component D

for the manufacture of housings and their semi-finished products by Kleintrans electrical appliances containing formers.

The described housings of small transformers containing electrical devices are scratch-resistant, stable and resistant to chemicals. They also show a very good one Resistance to yellowing and depth of color.

The components of the for the manufacture of the housing according to the invention by Electrical devices containing small transformers used according to the invention Thermoplastic molding compositions are known per se. For example, in DE-A-12 60 135, DE-C-19 11 882, DE-A-28 26 925, DE-A-31 49 358, DE-A-32 27 555 and DE-A-40 11 162 components and usable according to the invention Molding compounds described.

According to one embodiment, the components of the invention which are used to produce the housings of small electrical transformers containing small transformers which contain ABS, contain components A and B and C and, if appropriate, D, as defined below. They contain, based on the sum of the amounts of components A, B, C and optionally D, which gives a total of 100% by weight,

• 1. a: 1-48% by weight, preferably 3-35% by weight, in particular 5-30% by weight, of a particulate emulsion polymer with a glass transition temperature below 0 ° C and an average particle size of 50-1000 nm, preferably 50-800 nm, as component A,
• 2. b: 1-48% by weight, preferably 5-40% by weight, in particular 5-35% by weight,  at least one amorphous or partially crystalline polymer as a component B,
• 3. c: 51-98% by weight, preferably 55-90% by weight, in particular 60-85% by weight Polycarbonates as component C, and
• 4. d: 0-47% by weight, preferably 0-37% by weight, in particular 0-30% by weight Additives, and / or fibrous or particulate fillers or mixtures thereof as component D.

The invention is explained in more detail below.

First, the housing for the manufacture of the invention by Molding compounds containing electrical equipment used described and the components from which they are built.

COMPONENT A

Component A is at least one single or multi-phase particulate Emulsion polymer with a glass transition temperature below 0 ° C in at least one phase and an average particle size of 50-1000 nm.

Component A is preferably a multiphase polymer out

• 1. a1: 1-99% by weight, preferably 15-80% by weight, in particular 40-65% by weight, a particulate first phase A1 with a glass over transition temperature below 0 ° C,  
• 2. a2: 1-99% by weight, preferably 20-85% by weight, in particular 35-60% by weight, of a second phase A2 from the monomers, based on A2,
  • 1. a21: 40-100 wt .-%, preferably 65-85 wt .-%, units of a vinyl aromatic monomer, preferably styrene, a substituted styrene or a (meth) acrylic acid ester or mixtures thereof, in particular styrene and / or α-methylstyrene as component A21 and
  • 2. a22: up to 60% by weight, preferably 15-35% by weight, of units of an ethylenically unsaturated monomer, preferably acrylonitrile or methacrylonitrile, in particular acrylonitrile as component A22.
• 3. a3: 0 to 50% by weight of a third phase with a glass transition temperature of more than 0 ° C as component A3, the total amount of Components A1, A2 and A3 are 100% by weight.

The phases can be graft copolymerized with one another get connected. Here, for example, the first phase A1 Form the graft base and the second phase A2 a graft pad. It can several phases are provided, corresponding to a graft copolymer with one Graft base and several graft pads. However, the graft pad must be used not necessarily in the form of a sheath around the graft core. There are different geometries possible, for example part of the first phase A1 can be covered with the second phase A2, it can interpenetrate Form networks etc. The first phase A1 particularly preferably has one Glass transition temperature below -10 ° C, especially below -15 ° C. The third phase preferably has a glass transition temperature greater than 60 ° C. This third phase can be, for example, 1-50% by weight, in particular 5-40% by weight,  based on component A, are present.

In the following, "graft base" can also be understood instead of "first phase" be, according to "graft" instead of "second phase".

The third phase can preferably consist of more than 50% by weight of styrene, in particular from more than 80 wt .-% styrene, based on the total number of monomers third phase.

According to one embodiment of the invention, component A1 consists of the Monomers

• 1. a11: 80-99.99% by weight, preferably 95-99.9% by weight, of a C _1-8 alkyl ester of acrylic acid, preferably n-butyl acrylate and / or ethylhexyl acrylate as component A11,
• 2. a12: 0.01-20% by weight, preferably 0.1-5.0% by weight, of at least one polyfunctional crosslinking monomers as component A12.

According to one embodiment of the invention, the average particle size is Component A 50-1000 nm, preferably 50-800 nm.

According to a further embodiment according to the invention, the particle is Size distribution of component A bimodal, where 1-99, preferably 20-95, in particular 45-90% by weight an average particle size of 50-200 nm and 1-99, preferably 5-80, in particular 10-55% by weight of an average particle size have from 200-1000 nm, based on the total weight of component A.

The sizes determined from the integral mass distribution are given as the average particle size or particle size distribution. The average particle sizes according to the invention are in all cases the weight average of the particle sizes, as determined by means of an analytical ultracentrifuge according to the method of W. Scholtan and H. Lange, Kolloid-Z. and Z.-Polymer 250 (1972), pages 782-796. The ultracentrifuge measurement provides the integral mass distribution of the particle diameter of a sample. From this it can be seen what percentage by weight Ge of the particles have a diameter equal to or smaller than a certain size. The mean particle diameter, which is also referred to as the d ₅₀ value of the integral mass distribution, is defined here as the particle diameter at which 50% by weight of the particles have a smaller diameter than the diameter which corresponds to the d ₅₀ value. Likewise, 50% by weight of the particles then have a larger diameter than the d ₅₀ value. Value (median particle diameter) is selected from the integral mass distribution are d ₁₀ - - To characterize the particle size distribution width of the rubber in addition to the d ₅₀ and d ₉₀ values are used. The d ₁₀ or d ₉₀ value of the integral mass distribution is defined in accordance with the d ₅₀ value with the difference that they are based on 10 or 90% by weight of the particles. The quotient

represents a measure of the distribution width of the particle size.

The glass transition temperature of the emulsion polymer A as well as the other Components used according to the invention are by means of DSC (differential Scanning Calorimetry) according to ASTM 3418 (mid point temperature).  

Relevant customary rubbers can be used as emulsion polymer A. find, as in one embodiment of the invention, epichlorohydrin chew tschuke, ethylene vinyl acetate rubbers, polyethylene chlorosulfone rubbers, Silicone rubbers, polyether rubbers, hydrogenated diene rubbers, Polyalkenamer rubbers, acrylate rubbers, ethylene-propylene rubbers, Ethylene propylene diene rubbers, butyl rubbers and fluororubbers. Acrylate rubber, ethylene propylene (EP) rubber, ethylene Propylene-diene (EPDM) rubber, especially acrylate rubber, used.

Pure butadiene rubbers, such as those used in ABS, cannot be used as exclusive component A can be used. Preferably, the Molding compounds free from butadiene rubbers.

According to one embodiment, the diene basic component is in the emulsion polymer A kept so low that as little unreacted as possible Double bonds remain in the polymer. According to one embodiment no basic diene building blocks in emulsion polymer A.

The acrylate rubbers are preferably alkyl acrylate rubbers composed of one or more C _1-8 alkyl acrylates, preferably C _4-8 alkyl acrylates, preferably at least partially butyl, hexyl, octyl or 2-ethylhexyl acrylate, in particular n- Butyl and 2-ethylhexyl acrylate is used. These alkyl acrylate rubbers can contain up to 30% by weight of copolymerizable monomers, such as vinyl acetate, (meth) acrylonitrile, styrene, substituted styrene, methyl methacrylate or vinyl ether, in copolymerized form.

According to one embodiment of the invention, the acrylate rubbers contain further 0.01-20% by weight, preferably 0.1-5% by weight, of crosslinking acting, polyfunctional monomers (crosslinking monomers). Examples  for this are monomers which 2 or more were capable of copolymerization Contain double bonds, which are preferably not conjugated in the 1,3 positions are.

Suitable crosslinking monomers are, for example, ethylene glycol di (meth) acrylate, Butanediol, hexanediol di (meth) acrylate, divinylbenzene, diallyl maleate, diallyl fumarate, Diallyl phthalate, diethyl phthalate, triallyl cyanurate, triallyl isocyanurate, Tricyclodecenyl acrylate, dihydrodicyclopentadienyl acrylate, triallyl phosphate, Allyl acrylate, allyl methacrylate or dicyclopentadienyl acrylate (DCPA) (cf. DE-C-12 60 135).

Suitable silicone rubbers can e.g. B. crosslinked silicone rubbers from units of the general formulas R ₂ SiO, RSiO _3/2 , R ₃ SiO _1/2 and SiO _2/4 , where the radical R represents a monovalent radical. The amount of the individual siloxane units is such that 0 to 10 mol units of the formula RSiO _3/2 , 0 to 1.5 mol units R ₃ SiO _1/2 and 0 to 3 per 100 units of the formula R ₂ SiO Mol units of SiO _2/4 are present. R can be either a monovalent saturated hydrocarbon radical having 1 to 18 carbon atoms, the phenyl radical or the alkoxy radical or a group which is easily attackable by free radicals, such as the vinyl or mercaptopropyl radical. It is preferred that at least 80% of all R groups are methyl groups; combinations of methyl and ethyl or phenyl radicals are particularly preferred.

Preferred silicone rubbers contain built-in units by radical means tangible groups, especially vinyl, allyl, halogen, mercapto groups, preferably in amounts of 2-10 mol%, based on all radicals R. You can for example, are produced as described in EP-A-0 260 558.

In some cases it may be appropriate to use an emulsion polymer A.  to use uncrosslinked polymer. As monomers to make them Polymers can serve all of the monomers mentioned above. Preferred un Crosslinked emulsion polymers A are e.g. B. homo- and copolymers of Acrylic acid esters, especially n-butyl and ethylhexyl acrylate, and Homopolymers and copolymers of ethylene, propylene, butylene, isobutylene, as well Poly (organosiloxanes), all with the proviso that they are linear or branched allowed to.

Core / shell - emulsion polymer A

The emulsion polymer A can also be a multi-stage polymer (so-called "core / shell structure", "core-shell morphology"). For example, a rubber-elastic core (T _g <0 ° C) can be encased by a "hard" shell (polymers with T _g <0 ° C) or vice versa.

In a particularly preferred embodiment of the invention, the Component A is a graft copolymer. The graft copolymers A of the inventions Molding compositions according to the invention have an average particle size dso of 50-1000 nm, preferably from 50-800 nm.

The graft copolymer A is generally one or more stages, i. H. on off polymer composed of a core and one or more shells. The Polymer consists of a basic level (graft core) A1 and a number of it grafted stages A2 (graft layer), the so-called graft stages or Graft sleeves.

By simple grafting or multiple gradual grafting one or multiple graft shells are applied to the rubber particles, each Graft shell can have a different composition. In addition to the  grafting monomers can be polyfunctional crosslinking or reactive Monomers containing groups are also grafted on (see, for example, EP-A-0 230 282, DE-A-36 01 419, EP-A-0 269 861).

In a preferred embodiment, component A consists of a multi-stage graft copolymer, the graft stages being generally made from resin-forming monomers and having a glass transition temperature T _g above 30 ° C., preferably above 50 ° C. The outer graft shell serves, among other things, to achieve (partial) compatibility of the rubber particles A with the thermoplastic B.

Graft copolymers A are produced, for example, by grafting at least one of the monomers A2 listed below to at least one of the graft bases or graft core materials listed above A1. All graft bases A1 of the molding compositions according to the invention are Suitable polymers described above under the emulsion polymers A. are.

According to one embodiment of the invention, the graft base A1 is 15-99.9% by weight Acrylate rubber, 0.1-5% by weight crosslinker and 0-49.9% by weight composed of one of the specified further monomers or rubbers.

Suitable monomers for forming the graft A2 can be selected, for example, from the monomers listed below and their mixtures:
Vinylaromatic monomers, such as styrene and its substituted derivatives, such as α-methylstyrene, p-methylstyrene, 3,4-dimethylstyrene, p-tert-butylstyrene, and p-methyl-α-methylstyrene or C ₁ -C ₈ alkyl (meth ) acrylates such as methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate; styrene, α-methylstyrene, methyl methacrylate, in particular styrene and / or α-methylstyrene, and ethylenically unsaturated monomers, such as acrylic and methacrylic compounds, such as acrylonitrile, methacrylonitrile, acrylic and methacrylic acid, methyl acrylate, ethyl acrylate, n- and isopropyl acrylate, n - and isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n- and isopropyl, n- and isobutyl, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, maleic anhydride and its derivatives, such as maleic acid esters, maleic acid diesters and maleimides, z. B. alkyl and aryl maleimides, such as methyl, cyclohexyl or phenyl maleimide. Methacrylates, acrylonitrile and methacrylonitrile, in particular acrylonitrile, are preferred.

Furthermore, as (co) monomers styrene, vinyl, acrylic or methacrylic compounds (e.g. styrene, optionally substituted with C _1-12 alkyl radicals, halogen atoms, halogen methylene radicals; vinyl naphthalene, vinyl carbazole; vinyl ethers with C _{1- 12} - ether residues; vinylimidazole, 3- (4-) vinylpyridine, dimethylaminoethyl (meth) acrylate, p-dimethylaminostyrene, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, butyl acrylate, ethylhexyl acrylate and methyl methacrylate as well as fumaric acid, maleic acid, itaconic acid or their anhydride Nitriles or esters with 1 to 22 carbon atoms, preferably alcohols containing 1 to 10 carbon atoms) can be used.

According to one embodiment of the invention, component A comprises 50 to 100% by weight, preferably 50-90% by weight of the first phase described above (Graft base) A1 and 0 to 50 wt .-%, preferably 10-50 wt .-% of the Second phase described above (graft) A2, based on the Total weight of component A. The third phase includes styrene Copolymers into consideration.  

According to one embodiment of the invention, A1 serves as the graft base crosslinked acrylic acid ester polymers with a glass transition temperature below 0 ° C. The crosslinked acrylic ester polymers should preferably be one Glass transition temperature below -20 ° C, especially below -30 ° C, have.

In a preferred embodiment, the graft A2 consists of one or several graft shells, the outermost graft shell of which has a glass transition temperature of more than 30 ° C, one of the monomers of the graft A2 formed polymer have a glass transition temperature of more than 80 ° C. would.

Regarding the measurement of the glass transition temperature and the middle part size and the Q values apply to the graft copolymers A that for the Emulsion polymers A Said.

The graft copolymers A can also by grafting pre-formed ones Polymers are prepared on suitable graft homopolymers. Examples for this are the reaction products of maleic anhydride or acid groups containing copolymers with base-containing rubbers.

Suitable preparation processes for graft copolymers A are the emulsion, Solution, bulk or suspension polymerization. The are preferred Graft copolymers A prepared by radical emulsion polymerization, especially in the presence of latices of component A1 at temperatures of 20 ° C-90 ° C using water-soluble or oil-soluble initiators such as Peroxodisulfate or benzoyl peroxide, or with the help of redox initiators. Redox initiators are also suitable for polymerization below 20 ° C.

Suitable emulsion polymerization processes are described in DE-A-2826 925,  31 49 358 and in DE-C-12 60 135.

The graft casings are preferably built up in the emulsion polymerization process drive as described in DE-A-32 27 555, 31 49 357, 31 49 358, 34 14 118. The defined setting of the particle sizes according to the invention of 50-1000 nm is preferably carried out according to the methods described in DE-C-12 60 135 and DE-A-28 26 925, or Applied Polymer Science, Volume 9 (1965), page 2929. The use of polymers with different particle sizes is known for example from DE-A-28 26 925 and US 5,196,480.

According to the process described in DE-C-12 60 135, the Graft base A1 made by the one or more according to one embodiment the invention used acrylic acid esters and the multifunctional, the Crosslinking monomers, possibly together with the others Comonomers, in aqueous emulsion in a manner known per se at temperatures between 20 and 100 ° C, preferably between 50 and 80 ° C, polymerized become. The usual emulsifiers, such as alkali metal salts of alkyl or Alkylarylsulfonic acids, alkyl sulfates, fatty alcohol sulfonates, salts of higher fatty acids with 10 to 30 carbon atoms or resin soaps can be used. Preferably use the sodium salts of alkyl sulfonates or fatty acids with 10 to 18 Carbon atoms. According to one embodiment, the emulsifiers in Amounts of 0.5-5 wt .-%, in particular of 1-2 wt .-%, based on the the production of the graft base A1 used monomers. in the generally at a weight ratio of water to monomers of 2: 1 worked up to 0.7: 1. The polymerization initiators in particular serve as Common persulfates, such as potassium persulfate. However, it can redox systems are also used. The initiators are generally in amounts of 0.1-1 wt .-%, based on those in the manufacture of Graft base A1 monomers used. As another  Polymerization auxiliaries can be the usual buffer substances through which pH Values of preferably 6-9 can be set, such as sodium bicarbonate and Sodium pyrophosphate, and 0-3 wt .-% of a molecular weight regulator, such as Mercaptans, terpinols or dimeric α-methylstyrene in the polymerization be used.

In a next step, the graft polymer A is then prepared in Presence of the latex of the crosslinked acrylic ester polymer thus obtained according to one embodiment of the invention, a monomer mixture of styrene and acrylonitrile polymerized, the weight ratio of styrene to Acrylonitrile in the monomer mixture according to one embodiment of the Invention in the range of 100: 0 to 40:60, preferably in the range of 65:35 to 85: 15. It is advantageous to this graft copolymerization of styrene and acrylonitrile on the crosslinked graft Polyacrylic acid ester polymer again in aqueous emulsion under the usual perform the conditions described above. The graft copolymerization can expediently take place in the same system as the emulsion polymerization for the preparation of the graft base A1, wherein, if necessary, further emulsifier and initiator can be added. That according to an embodiment of the Invention grafted monomer mixture of styrene and acrylonitrile can the reaction mixture at once, batchwise in several stages or preferentially be added continuously during the polymerization. The Graft copolymerization of the mixture of styrene and acrylonitrile in the presence of the crosslinking acrylic ester polymer is carried out in such a way that a degree of grafting of 1-99% by weight, preferably 20-85% by weight, in particular 35-60% by weight on the total weight of component A, resulting in graft copolymer A. There the graft yield in the graft copolymerization is not 100%, one must somewhat larger amount of the monomer mixture of styrene and acrylonitrile in the Graft copolymerization can be used as the desired degree of grafting  corresponds. The control of the graft yield in the graft copolymerization and thus the degree of grafting of the finished graft copolymer A is known to the person skilled in the art common and can for example u. a. through the metering speed of the mono or by adding a regulator (Chauvel, Daniel, ACS Polymer Preprints 15 (1974), page 329 ff.). The emulsion graft copolymerization results in generally a few% by weight, based on the graft copolymer, of free, ungrafted styrene / acrylonitrile copolymer. The share of Graft copolymer A in that obtained in the graft copolymerization The polymerization product is determined using the method given above.

In the preparation of the graft copolymers A by the emulsion process in addition to the existing process engineering advantages, also reproducible Particle size changes possible, for example by at least partially Agglomeration of the particles into larger particles. This means that in the Graft copolymers A also include polymers with different particle sizes can be present.

In a special embodiment have bimodal Particle size distributions of component A have proven to be particularly advantageous. These can be created by mixing separately produced particles of different sizes, which are also different in their Composition and in their shell structure (core / shell, Core / shell / shell etc.), or one creates a bimodal Particle size distribution by partial agglomeration before, during or after the graft.

In particular, component A from the graft base and graft shell (s) can be used for the can be optimally adapted to the respective purpose, in particular with regard to the particle size.  

The graft copolymers A generally contain 1-99% by weight, preferably 15-80 and particularly preferably 40-65% by weight of first phase (graft base) A1 and 1-99 wt .-%, preferably 20-85, particularly preferably 35-60 wt .-% of the second Phase (graft) A2, based in each case on the entire graft copolymer.

COMPONENT B

Component B is an amorphous or partially crystalline polymer.

Component B is preferably a copolymer of

• 1. b1: 40-100 wt .-%, preferably 60-85 wt .-%, units of a vinyl aromatic cal monomers, preferably styrene, a substituted styrene or a (meth) acrylic acid ester or mixtures thereof, especially styrene and / or α-methylstyrene as component B1,
• 2. b2: up to 60% by weight, preferably 15-40% by weight, units of an ethylenic unsaturated monomer, preferably acrylonitrile or methacrylonitrile, especially acrylonitrile as component B2,
• 3. b3: up to 60% by weight of a further ethylenically unsaturated copolymerizable Monomers.

According to a preferred embodiment of the invention, the visco is tity number of component B 50-120, preferably 55-100.

The amorphous or partially crystalline polymers of component B for Manufacture of the housing of small transformers according to the invention  Tending electrical equipment molding compound used according to the invention, are from minde least a polymer of partially crystalline polyamides, partially aromatic Co polyamides, polyolefins, ionomers, polyesters, polyether ketones, polyoxyalkyls NEN, polyarylene sulfides and preferably polymers of vinyl aromatic Monomers and / or ethylenically unsaturated monomers selected. It can polymer mixtures can also be used.

As component B for the manufacture of the housing according to the invention by Electrical devices containing small transformers used according to the invention Molding compositions are also partially crystalline, preferably linear polyamides such as polyamide-6, Polyamide-6,6, polyamide-4,6, polyamide-6,12 and partially crystalline copolyamides Suitable based on these components. Furthermore, partially crystalline polyamides are used, the acid component wholly or partly of adipic acid and / or terephthalic acid and / or isophthalic acid and / or suberic acid and / or Sebacic acid and / or acelaic acid and / or dodecanedicarboxylic acid and / or one Cyclohexanedicarboxylic acid, and its diamine component entirely or partly in particular from m- and / or p-xylylenediamine and / or hexams ethylene diamine and / or 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine and / or isophoronediamine, and their compositions in principle are known in the prior art (cf. Encyclopedia of Polymers, Vol. 11, p. 315 ff.).

Examples of as component B for the preparation of the invention Housing of Kleitransformatoren containing electrical devices according to the invention The molding materials used are also partially crystalline Polyolefins, preferably homo- and copolymers of olefins such as ethylene, Propylene, butene-1, pentene-1, hexene-1, heptene-1, 3-methylbutene-1, 4-methylbutene-1, 4-methylpentene-1 and octene-1. Suitable polyolefins are polyethylene, Polypropylene, polybutene-1 or poly-4-methylpentene-1. Generally differs  polyethylene (PE), high-density PE (HDPE), low-density PE (LDPE) and linear low density PE (LLDPE).

In another embodiment of the invention, component B is an ionomer. These are generally polyolefins as described above, especially polyethylene, which contain monomers co-condensed with acid groups, e.g. B. acrylic acid, methacrylic acid and optionally other copolymerizable monomers. The acid groups are generally converted with the aid of metal ions such as Na ⁺ , Ca ²⁺ , Mg ²⁺ and Al ³⁺ into ionic, optionally ionically crosslinked polyolefins, which, however, can still be processed thermoplastically (see, for example, US Pat. No. 3,264,272; 3,404,134; 3,355,319; 4,321,337). However, it is not absolutely necessary to convert the polyolefins containing acid groups by means of metal ions. Also polyolefins containing free acid groups, which then generally have a rubber-like character and in some cases also contain further copolymerizable monomers, e.g. B. (meth) acrylates are suitable as component B according to the invention.

In addition, component B can also be polyester, preferably aromatic aliphatic polyester can be used. Examples are polyalkylene terephthalates, e.g. B. based on ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,4-bis-hydroxymethyl-cyclohexane, and polyalkylene naphthalates.

Aromatic polyether ketones can also be used as component B. be how they z. B. are described in the publications GB 1 078 234, US 4,010,147, EP-A-0 135 938, EP-A-0 292 211, EP-A-0 275 035, EP-A-0 270 998, EP-A-0 165 406, and in the publication by C. K. Sham et. al., Polymer 29/6, 1016-1020 (1988).

Component B can also be used for the preparation of the invention  Housing of small transformers containing electrical devices according to the invention molding compounds used polyoxyalkylenes, for. B. polyoxymethylene, and Oxymethylene polymers are used.

Other suitable components B are the polyarylene sulfides, in particular that Polyphenylene sulfide.

An amorphous copolymer of styrene and / or is preferably used as component B. α-methylstyrene used with acrylonitrile. The acrylonitrile content in these Copolymers of component B are 0-60% by weight, preferably 15-40% by weight, based on the total weight of component B. To the component B also includes those in the graft copolymerization to produce the component A free, non-grafted styrene / acrylonitrile copolymers formed. Depending on in the graft copolymerization for the preparation of the graft copolymer A selected conditions, it may be possible in the graft copolymerization a sufficient proportion of component B has already been formed. in the in general, however, it will be necessary for the graft copolymerization products obtained with additional, separately manufactured component B to mix.

This additional, separately manufactured component B can preferably a styrene / acrylonitrile copolymer, an α-methylstyrene / acrylic nitrile copolymer or an α-methylstyrene / styrene / acrylonitrile terpolymer act. These copolymers can be used individually or as a mixture for the Component B can be used, so that it is in the additional, separately Component B produced of the molding compositions used according to the invention for example, a mixture of a styrene / acrylonitrile copolymer and can act an α-methylstyrene / acrylonitrile copolymer. In the case where component B of the molding compositions used according to the invention from a  Mixture of a styrene / acrylonitrile copolymer and an α- Methylstyrene / acrylonitrile copolymer is preferably the Acrylonitrile content of the two copolymers by no more than 10% by weight, preferably not more than 5% by weight, based on the total weight of the Copolymer, differ from each other. Component B of the invention The molding compounds used can, however, also consist only of a single styrene / acrylic nitrile copolymer exist when in the graft copolymerizations Production of component A as well as in the production of the additional, separately Component B produced from the same monomer mixture of styrene and Acrylonitrile is assumed.

The additional, separately manufactured component B can according to the conventional Procedure can be obtained. So according to one embodiment of the invention the copolymerization of the styrene and / or α-methylstyrene with the acrylonitrile in Mass, solution, suspension or aqueous emulsion are carried out. The Component B preferably has a viscosity number of 40 to 120, preferably 50 up to 120, in particular 55 to 100. The viscosity number is determined here according to DIN 53 726, 0.5 g of material are dissolved in 100 ml of dimethylformamide.

Mixing components A and B can be done in any way all known methods. If components A and B for example, have been prepared by emulsion polymerization, it is possible to mix the polymer dispersions obtained, then the Precipitate polymers together and work up the polymer mixture. However, components A and B are preferably mixed by extruding, kneading or rolling the components together, the Components, if necessary, previously obtained from the polymerization Solution or aqueous dispersion have been isolated. The in aqueous dispersion Products obtained from the graft copolymerization (component A) can also only  be partially drained and as a moist crumb with component B are mixed, the complete during the mixing The graft copolymers are dried.

COMPONENT C

Suitable polycarbonates C are known per se. They preferably have a molecular weight (weight average M _w , determined by means of gel permeation chromatography in tetrahydrofuran against polystyrene standards) in the range from 10,000 to 60,000 g / mol. You are e.g. B. according to the method of DE-B-13 00 266 by interfacial polycondensation or according to the method of DE-A-1495 730 by reaction of diphenyl carbonate with bisphenols. Preferred bisphenol is 2,2-di (4-hydroxyphenyl) propane, generally - as also hereinafter - referred to as bisphenol A.

Instead of bisphenol A, other aromatic dihydroxy compounds can also be used used, in particular 2,2-di (4-hydroxyphenyl) pentane, 2,6- Dihydroxynaphthalene, 4,4'-dihydroxydiphenyl sulfane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfite, 4,4'-dihydroxydiphenylmethane, 1,1-di- (4- hydroxyphenyl) ethane, 4,4-dihydroxydiphenyl or dihydroxydiphenylcycloalkanes, preferably dihydroxydiphenylcyclohexanes or dihydroxylcyclopentanes, in particular 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and Mi of the aforementioned dihydroxy compounds.

Particularly preferred polycarbonates are those based on bisphenol A. or bisphenol A together with up to 80 mol% of the above aromatic dihydroxy compounds.

Copolycarbonates according to US Pat. No. 3,737,409 can also be used; of Copolycarbonates based on bisphenol A are of particular interest  and di- (3,5-dimethyl-dihydroxyphenyl) sulfone, which is characterized by a high Characterize heat resistance. It is also possible to use mixtures use different polycarbonates.

According to the invention, the average molecular weights (weight average M _w , determined by means of gel permeation chromatography in tetrahydrofuran against polystyrene standards) of the polycarbonates C are in the range from 10,000 to 64,000 g / mol. They are preferably in the range from 15,000 to 63,000, in particular in the range from 15,000 to 60,000 g / mol. This means that the polycarbonates C have relative solution viscosities in the range from 1.1 to 1.3, measured in 0.5% strength by weight solution in dichloromethane at 25 ° C., preferably from 1.15 to 1.33. The relative solution viscosities of the polycarbonates used preferably differ by no more than 0.05, in particular no more than 0.04.

The polycarbonates C can be used both as regrind and in granular form be used. They are present as component C in amounts of 51-98% by weight, preferably from 55-90% by weight, in particular 60-85% by weight, in each case based on the entire molding compound.

The addition of polycarbonates results in one embodiment of the invention among other things to higher thermal stability and improved crack resistance of the for producing the housing of small transformers according to the invention containing electrical equipment used in the invention.

COMPONENT D

As component D contain the housing for the manufacture of the invention of small transformers containing electrical devices used according to the invention preferred thermoplastic molding compositions 0-50% by weight, preferably 0-37% by weight,  in particular 0-30% by weight of fibrous or particulate fillers and other additives or their mixtures, each based on the total Molding compound. These are preferably commercially available Products.

Reinforcing agents such as carbon fibers and glass fibers are commonly used in Amounts of 5-50 wt .-% used, based on the total molding compound.

The glass fibers used can be made of E, A or C glass and are preferred wise equipped with a size and an adhesion promoter. Your diameter is generally between 6 and 20 microns. It can be both continuous fibers (rovings) as well as cut glass fibers (staple) are used.

Furthermore, fillers or reinforcing materials such as glass balls, mineral fibers, Whiskers, aluminum oxide fibers, mica, quartz flour and wollastonite added become.

In addition, metal flakes (e.g. aluminum flakes from Transmet Corp.), Metal powder, metal fibers, metal-coated fillers, e.g. B. nickel coated Glass fibers and other additives that shield electromagnetic waves, those used to manufacture the housing according to the invention Molding compounds are added. Aluminum flakes (K 102 from Transmet) for EMI purposes (electro-magnetic interference). Furthermore, the masses with additional carbon fibers, soot, in particular Conductivity carbon black or nickel-coated carbon fibers can be mixed.

The to manufacture the housing of small transformers according to the invention containing electrical equipment used in the invention also contain other additives D, for polycarbonates, SAN polymers  and graft copolymers or mixtures thereof are typical and customary. Examples of such additives are: dyes, pigments, dyes agents, antistatic agents, antioxidants, stabilizers to improve the Thermostability, to increase light stability, to increase the Resistance to hydrolysis and chemical resistance, buffer substances, Flame retardant drip inhibitors, transesterification inhibitors, agents against the Heat decomposition and especially the lubricants / waxes and waxes that are used for the production of moldings or moldings are appropriate. The These additional additives can be metered in at any stage of the Manufacturing process take place, but preferably at an early stage, to the stabilization effects (or other special effects) of the Exploit additive. Are heat stabilizers or oxidation retardants Usually metal halides (chlorides, bromides, iodides), which are made of metals derived from Group I of the Periodic Table of the Elements (such as Li, Na, K, Cu). Other suitable stabilizers are the usual hindered phenols, but also Vitamin E or analogue compounds. Also HALS stabilizers (Hindered Amine Light Stabilizers), Benzophenone, Resorcine, Salicylate, Benzotriazoles and other compounds are suitable (for example Irganox®, Tinuvin®, such as Tinuvin® 770 (HALS absorber, bis (2,2,6,6-tetramethyl-4- piperidyl) sebazate) or Tinuvin®P (UV absorber - (2H-benzotriazol-2-yl) -4-me thylphenol), Topanol®). These are usually used in amounts of up to 2% by weight. (based on the total mixture) used.

Suitable lubricants and mold release agents are stearic acids, stearyl alcohol, Stearic acid esters or generally higher fatty acids, their derivatives and ent speaking fatty acid mixtures with 12-30 carbon atoms. The amounts of this Additions are in the range of 0.05-1% by weight.

Silicone oils, oligomeric isobutylene or similar substances also come as  Additives in question, the usual amounts are 0.05-5 wt .-%. Pigments, Dyes, color brighteners, such as ultramarine blue, phthalocyanines, titanium dioxide, Cadmium sulfides, derivatives of perylene tetracarboxylic acid can also be used.

Commercial halogen-free or halogen-containing flame retardants can also be used in customary amounts, for example up to 50% by weight. examples for Halogen-free flame retardants are described in EP-A-0 149 813. Otherwise be referred to DE-A-34 36 815, in particular poly (tetrabromobisphenol-A- (glycidyl) ether) with a molecular weight of 40,000 is preferred.

Processing aids and stabilizers such as UV stabilizers, lubricants and antistatic agents are usually used in amounts of 0.01-5% by weight, based on the total molding compound.

The manufacture of the housing for the manufacture of the invention Electrical devices containing small transformers used according to the invention Thermoplastic molding compositions can by known methods Mix the components. It can be beneficial to individual Premix components. Also mixing the components in solution and It is possible to remove the solvents.

Suitable organic solvents are, for example, chlorobenzene, mixtures of Chlorobenzene and methylene chloride or mixtures of chlorobenzene or aromati hydrocarbons, e.g. B. toluene.

Evaporation of the solvent mixtures can, for example, in evaporation extru be done.

Mixing the z. B. dry components can by all known metho  the done. However, the mixing is preferably done by common Extruding, kneading or rolling the components, preferably at temperatures of 180-400 ° C, where necessary the components previously from the at Solution obtained or isolated from the aqueous dispersion are.

The components can be metered in together or separately / one after the other become.

The housing of small transformers containing the invention Electrical devices can be according to an embodiment of the invention according to the knew methods of thermoplastic processing from the invention used thermoplastic molding compositions are produced. In particular, can production by thermoforming, extrusion, injection molding, calendering, Hollow body blowing, pressing, press sintering, deep drawing or sintering, preferably by injection molding. Especially when calendering and deep drawing are used as Intermediate plates and foils produced or used.

The molding compositions used according to the invention are used to produce Housings and their semi-finished products for electrical transformers containing small transformers used.

Such electrical devices can for example be devices in which in addition to small trans other electrical assemblies or mechanical assemblies are accommodated. Examples are computers and consumer electronics from the Audio or video area. The housing can also be used for power supplies, for example or chargers for accumulators can be used. The housings can too only the transformer and other small electronic components such as diodes or pick up rectifier. Such separate transformers are often used for  Low voltage power supply. You come, for example, with the lighting (Halogen spotlights). Power supplies that are separate from electrical devices are used and from a plug-in transformer exist, which is plugged directly into a standard socket, and one Connection cable for the electrical device. The housing according to the invention can are used especially where they are exposed to heat and light. Due to the heat development in transformers, these are usually one exposed to permanent stress.

The housing can have any shape, provided that it accommodates Small transformers allowed. The housings usually instruct in particular Power supplies or chargers for accumulators only small gaps between the wall and the small transformer, so that they in close are in thermal contact with the small transformer.

The housing consisting of the molding compositions according to the invention have a very good chemical resistance and dimensional stability. They are also scratch-resistant, which is a great advantage especially when cleaning.

In addition, the housings of small transformers according to the invention are included tendency electrical devices resistant to yellowing and very stable. You instruct balanced ratio of toughness and bending stiffness.

Due to the high content of polycarbonates in the molding compounds, the housing of electrical transformers containing small transformers is very heat-resistant and resistant to persistent heat. By adding the polycarbonate as Component C is the heat resistance and impact resistance of Housings of small transformers containing electrical devices further improved. These housings of small transformers contain electrical devices  also good dimensional stability and excellent resistance Stability against heat aging and a high resistance to yellowing thermal stress and exposure to UV radiation.

The housings of small transformers containing electrical devices show for this excellent surface textures, even without additional surfaces treatment can be obtained. By appropriate modification of the rubber Morphology can change the appearance of the finished surfaces of the housing Electrical devices containing small transformers are modified, for example to achieve glossy or matt surface designs. The Housings of small transformers containing electrical devices show Exposure to weather and UV radiation a very low graying or yellowing effect, so that the surface properties are retained. Further advantageous properties of the housings of small transformers electrical appliances containing the high weather stability, good thermal Resistance, high resistance to yellowing under UV radiation and thermal Load, good stress crack resistance, especially when exposed to Chemicals, and good anti-electrostatic behavior. They also have one high color stability, for example due to the excellent resistance against yellowing and embrittlement. The housing of the invention Small transformers containing electrical devices from the ver Thermoplastic molding materials used show both at low temperatures no significant loss of toughness, even after prolonged exposure to heat or impact strength, which is retained even when exposed to UV rays. The tensile strength is also retained. Furthermore show the invention Molding compounds and housings of small transformers containing electrical devices from this high resistance to scratching, a high resistance to Swelling as well as low permeability to liquids and gases, such as also good fire resistance.  

It is possible to manufacture the housing according to the invention from Klein electrical devices containing transformers according to the present invention Recycle already used thermoplastic molding compounds. Due to the high color stability, weather resistance and aging resistance are the Molding compositions used according to the invention are very suitable for Reuse. The proportion of reused (recycled) Molding compound must be high. When using, for example, 30% by weight already ver turned molding composition, which is used in the ground form according to the invention The relevant material properties changed when molding compounds were added such as flowability, Vicat softening temperature and impact resistance of the Molding compounds and the housing according to the invention produced therefrom by Small transformers containing electrical devices are not significant. Similar results Results were obtained from the weather resistance test. The Impact resistance was also when using recycled thermo plastic molding compounds constant over a long time, see Lindenschmidt, Ruppmich, Hoven-Nievelstein, International Body Engineering Conference, 21-23 September 1993, Detroit, Michigan, USA, Interior and Exterior Systems, pages 61 to 64. The resistance to yellowing was also retained.

The invention is illustrated by the following examples.  

EXAMPLES example 1 Production of small-part graft copolymer (A)

• 1. 16 parts of butyl acrylate and 0.4 part of tricyclodecenyl acrylate were added to 150 parts of water with the addition of part of the sodium salt of a C ₁₂ to C ₁₈ paraffin sulfonic acid, 0.3 part of potassium persulfate, 0.3 part of sodium hydrogen carbonate and 0.15 part of sodium pyrophosphate heated to 60 ° C with stirring. 10 minutes after the polymerisation reaction had started, a mixture of 82 parts of butyl acrylate and 1.6 parts of tricyclodecenyl acrylate was added over the course of 3 hours. After the monomer addition had ended, the mixture was left to react for an hour. The latex of the crosslinked butyl acrylate polymer obtained had a solids content of 40% by weight. The mean particle size (weight average) was found to be 76 nm. The particle size distribution was narrow (quotient Q = 0.29).
• 2. 150 parts of the polybutyl acrylate latex obtained according to (a1) were mixed with 40 Dividing a mixture of styrene and acrylonitrile (weight ratio 75:25) and 60 parts of water mixed and with stirring after adding a further 0.03 part of potassium persulfate and 0.05 part of lauroyl peroxide 4 Heated to 65 ° C for hours. After finishing the graft mixed polymerization was the polymerization product by means of Calcium chloride solution precipitated from the dispersion at 95 ° C, with water washed and dried in a warm air stream. The degree of grafting of the Graft copolymer was 35%.

Example 2 Production of large-scale graft copolymer (A)

• 1. On the one hand, after adding 50 parts of water and 0.1 part of potassium persulfate in the course of 3 hours, a mixture of 49 parts of butyl acrylate and 1 Part of tricyclodecenyl acrylate and, on the other hand, a solution of 0.5 part of the sodium salt of a C ₁₂ to C ₁₈ paraffin sulfonic acid in 25 parts of water at 60 ° C. After the end of the feed, polymerization was continued for 2 hours. The latex of the crosslinked butyl acrylate polymer obtained had a solids content of 40%. The average particle size (weight average of the latex) was found to be 288 nm. The particle size distribution was narrow (Q = 0.1).
• 2. 150 parts of this latex were mixed with 40 parts of a mixture of styrene and Acrylonitrile (ratio 75:25) and 110 parts water mixed and under Stir after adding a further 0.03 parts of potassium persulfate and 0.05 Parts of lauroyl peroxide heated to 65 ° C for 4 hours. That at the Graft copolymerization polymerization product obtained was then using a calcium chloride solution at 95 ° C from the dispersion precipitated, separated, washed with water and in a warm air stream dried. The degree of grafting of the graft polymer was 27% determined.

Example 3 Production of large-scale graft copolymer (A)

• 1. 16 parts of butyl acrylate and 0.4 part of tricyclodecenyl acrylate were added to 150 parts of water with the addition of 0.5 part of the sodium salt of a C ₁₂ to C ₁₈ paraffin sulfonic acid, 0.3 part of potassium persulfate, 0.3 part of sodium hydrogen carbonate and 0.15 Parts of sodium pyrophosphate heated to 60 ° C with stirring. A mixture of 82 parts of butyl acrylate and 1.6 parts of tricyclodecenyl acrylate was added within 3 hours 10 minutes after the start of the polymerization reaction. After the monomer addition had ended, the mixture was left to react for an hour. The latex of the crosslinked butyl acrylate polymer obtained had a solids content of 40% by weight. The average particle size (weight average) was found to be 216 nm. The particle size distribution was narrow (Q = 0.29).
• 2. 150 parts of the polybutyl acrylate latex obtained according to (a1) were mixed with 20 Parts of styrene and 60 parts of water mixed and stirring Add another 0.03 part of potassium persulfate and 0.05 part Lauroyl peroxide heated to 65 ° C for 3 hours. After finishing the first The graft copolymer had the stage of the graft copolymerization a degree of grafting of 17%. This graft copolymer dispersion was without further additives with 20 parts of a mixture of styrene and acrylonitrile (ratio 75:25) polymerized for a further 3 hours. To The product was terminated by means of graft copolymerization Calcium chloride solution precipitated from the dispersion at 95 ° C, with water washed and dried in a warm air stream. The degree of grafting of the Graft copolymer was 35%, the average particle size Latex particles were found to be 238 nm.

Example 4 Production of large-scale graft copolymer (A)

• 1. On the one hand, after adding 50 parts of water and 0.1 part of potassium persulfate, a mixture of 49 parts of butyl acrylate and 1 part of tricyclodecenyl acrylate and on the other hand, a solution of 0.5 part of the sodium salt of a C ₁₂ to C ₁₈ paraffin sulfonic acid in 25 parts of water was run in at 60 ° C. After the end of the feed, polymerization was continued for 2 hours. The latex of the crosslinked butyl acrylate polymer obtained had a solids content of 40%. The mean particle size (weight average) of the latex was found to be 410 nm. The particle size distribution was narrow (Q = 0.1).
• 2. 150 parts of the polybutyl acrylate latex obtained according to (a1) were mixed with 20 Parts of styrene and 60 parts of water mixed and stirring Add another 0.03 part of potassium persulfate and 0.05 part Lauroyl peroxide heated to 65 ° C for 3 hours. The one at this Graft copolymerization dispersion was then at 20 Share a mixture of styrene and acrylonitrile in a ratio of 75:25 polymerized for a further 4 hours. The reaction product was then using a calcium chloride solution at 95 ° C from the dispersion precipitated, separated, washed with water and in a warm air stream dried. The degree of grafting of the graft copolymer was 35% determined, the average particle size of the latex particles was 490 nm.

Example 5 Production of large-scale graft copolymer (A)

• 1. 98 parts of butyl acrylate and 2 parts of tricyclodecenyl acrylate were polymerized in 154 parts of water with the addition of 2 parts of dioctylsulfosuccinate sodium (70% strength) as emulsifier and 0.5 parts of potassium persulfate with stirring for 3 hours at 65 ° C. An approximately 40% dispersion was obtained. The average particle size of the latex was approximately 100 nm.
  A mixture of 49 parts of butyl acrylate, 1 part of tricyclodecenyl acrylate and 0.38 part of the emulsifier was added to a template of 2.5 parts of this latex, 400 parts of water and 0.5 part of potassium persulfate at 65 ° C. within 1 hour. In the course of a further hour, a mixture of 49 parts of butyl acrylate, 1 part of tricyclodecenyl acrylate and 0.76 part of emulsifier was added. After adding 1 part of potassium persulfate in 40 parts of water, a mixture of 196 parts of butyl acrylate, 4 parts of tricyclodecenyl acrylate and 1.52 parts of the emulsifier was finally added dropwise within 2 hours. The polymer mixture was then polymerized at 65 ° C. for a further 2 hours. An approximately 40% dispersion with an average particle diameter of approximately 500 nm was obtained.
  If only 100 parts were added instead of a total of 300 parts of monomers, a latex with an average particle diameter of about 300 nm was obtained.
• 2. 465 parts of styrene and 200 parts of acrylonitrile were in the presence of 2500 Divide the polymer latex according to (a1) with the average particle size 0.1 or 0.3 or 0.5 µm, 2 parts of potassium sulfate, 1.33 parts of lauryl peroxide and 1005 parts of water polymerized with stirring at 60 ° C. You got a 40% dispersion from which the solid product by adding a  0.5% calcium chloride solution precipitated, washed with water and was dried.

Example 6 Production of copolymer (B)

A mixture of monomers of styrene and acrylonitrile was used under usual Conditions polymerized in solution. The styrene / acrylonitrile copoly obtained merisat had an acrylonitrile content of 35% by weight, based on the Co polymer, and a viscosity number of 80 ml / g.

Example 7 Production of copolymer (B)

A mixture of monomers of styrene and acrylonitrile was used under usual Conditions polymerized in solution. The styrene / acrylonitrile copoly obtained merisat had an acrylonitrile content of 35% by weight, based on the Copolymer, and a viscosity number of 60 ml / g.

Example 8 Production of copolymer (B)

A mixture of monomers of styrene and acrylonitrile was used under usual Conditions polymerized in solution. The styrene / acrylonitrile copoly obtained merisat had an acrylonitrile content of 27% by weight, based on the Co  polymer, and a viscosity number of 80 ml / g.

Comparative Example 1 ABS polymer

A polybutadiene rubber was used as the comparative polymer was grafted with a styrene-acrylonitrile copolymer as component (A), which in a styrene-acrylonitrile copolymer matrix was present as component (B). The salary of graft rubber was 30% by weight, based on the total weight of the finished product Polymer.

Example 9 Component C

A conventional polycarbonate (PC) was used as component C, the one Viscosity number of 61.5 ml / g, determined in the solvent methylene chloride. According to the information in Table 1 below, the specified Amounts of the corresponding polymers (A), (B) and (C) or Comparative masses in a screw extruder at a temperature of 250 ° C-280 ° C mixed. Moldings were formed from the molding compositions formed in this way manufactured.  

The composition of the molding compositions is shown in the table below:

Table I

Investigation results a: scratch resistance

The scratch resistance is measured using a CSEM Automatic Scratch Tester model AMI (Manufacturer: Center Suisse d'Electronique et de Microtechnique S. A.) determined. The Scratch tester has a diamond tip with a 120 ° tip angle and 0.2 mm Radius. With this diamond tip, injection molded specimens are made from the Material to be tested introduced scratches of 5 mm in length. The pressure force of the Unless otherwise stated, diamonds are 2.6 N. After one hour Waiting time, the resulting scratches are scanned in the transverse direction and as Height / depth profile shown. The scratch depth can then be read from this.

b: Stress crack resistance

The resistance to stress cracking is determined with the bending strip method according to ISO 4599 certainly. The test specimens used are injection molded. she have the dimensions 80 × 15 × 2 mm. Unless otherwise stated, a Bending radius of the test specimens worked by 50 mm. The test specimens were used clamped in a template, bent and with the test medium for 24 h wetted. Then the impact work at break is determined with a pendulum. Isopropanol was used as the test medium in b1. In b2 it became a common one Household cleaner (Ajax Ultra Classic® from Colgate Palmolive Germany surfactant household cleaner) used.

c: swelling

To measure swelling, injection molded shoulder bars (tension bars according to ISO 3167 with a thickness of 4 mm) for 96 h in the medium to be tested  stored. Then they are superficially dried, and the Weight change and, if necessary, the change in the tensile modulus of elasticity (determined according to ISO 527) are determined in comparison to the initial value. In Table II, c1 is the change in weight in methanol, in c2 in super gasoline and in c3 shows the change in the tensile modulus of elasticity in super gasoline.

permeability

To test the permeability, foils are pressed from the material to be tested (thickness approx. 120 to 250 µm), the permeability of which to the specified gases or liquids is determined at 23 ° C. The values are given in (cm ³ 100 µm) / (m ² d bar) for gases or in (g 100 µm) / (m ² d) for water (Table III).

Molding compositions which can be used advantageously should meet the following conditions: Scratch depth of less than 6 µm, change in impact work compared to Baseline less than 10%, swelling in methanol less than 1% or swelling and change in modulus of elasticity of less than 6% in premium gasoline.

The results are shown in Tables II and III below.

In addition, the molding compound III and the comparative molding compound VII Swelling investigated at different exposure times. The results are in Table IV below:

Table IV

Swelling (change in weight) in methanol and premium petrol

Furthermore, the was for the molding compound III and the comparative molding compound VII Fogging behavior according to VW-PV 3015, method B (100 ° C, 16 h) examined. It no significant quantities could be analyzed.

The molding compositions with a polycarbonate content of more than 50% by weight showed an excellent combination of properties. This beneficial The spectrum of properties makes them particularly suitable for use in housings Electrical devices containing small transformers thereof are suitable.

Claims (10)

1. Use of a thermoplastic molding composition other than ABS, comprising, based on the sum of the amounts of components A, B, C and optionally D, which gives a total of 100% by weight,

• 1. a: 1-48% by weight of at least one single-phase or multi-phase particulate emulsion polymer with a glass transition temperature below 0 ° C. in at least one phase and an average particle size of 50-1000 nm, as component A,
• 2. b: 1-48% by weight of at least one amorphous or partially crystalline polymer as component B,
• 3. c: 51-98% by weight of polycarbonates as component C, and
• 4. d: 0-47% by weight of conventional additives and / or fibrous or particulate fillers or mixtures thereof as component D.

for the production of housings and their semi-finished products from small transformers containing electrical devices. 2. Use according to claim 1, characterized in that component A is a multi-phase polymer from

• 1. a1: 1-99% by weight of a particulate first phase A1 with a glass transition temperature below 0 ° C.,
• 2. a2: 1-99% by weight of a second phase A2 from the monomers, based on A2,
• 3. a21: 40-100 wt .-% units of a vinyl aromatic monomer as component A21 and
• 4. a22: up to 60% by weight of units of an ethylenically unsaturated monomer as component A22,
• 5. a3: 0 to 50 wt .-% of a third phase with a glass transition temperature of more than 0 ° C as component A3, the total amount of components A1, A2 and A3 giving 100 wt .-%.

3. Use according to claim 2, characterized in that the molding compound as a particulate first phase A1 an acrylate, EP, EPDM or Contains silicone rubber. 4. Use according to claim 3, characterized in that component A1 consists of the monomers

• 1. a11: 80-99.99% by weight of a C _1-8 alkyl ester of acrylic acid as component A11,
• 2. a12: 0.01-20% by weight of at least one polyfunctional crosslinking monomer as component A12.

5. Use according to one of claims 1 to 4, characterized in that the particle size distribution of component A is bimodal, 1-99% by weight  an average particle size of 50-200 nm and 1-99 wt .-% a have average particle size of 200-1000 nm, based on the total weight of component A. 6. Use according to one of claims 1 to 5, characterized in that the housings essentially only contain a small transformer. 7. Use according to one of claims 1 to 6, characterized in that the electrical devices are power packs or chargers for accumulators. 8. Housings of small transformers containing electrical devices from one thermoplastic molding composition as defined in one of claims 1 to 5 is. 9. Housing according to claim 8, characterized in that the Electrical devices are power supplies or battery chargers. 10. Use according to one of claims 1 to 5 for the production of Semi-finished products, profiles, tubes, foils and plates used to manufacture the Housing are processed.