EP0923494A1

EP0923494A1 - Heat-insulated transport containers

Info

Publication number: EP0923494A1
Application number: EP97940025A
Authority: EP
Inventors: Herbert Naarmann; Graham Edmund Mc Kee; Alfred Pirker; Hans-Josef Sterzel; Franz Brandstetter; Bernd-Steffen Von Bernstorff; Bernhard Rosenau; Ulrich Endemann; Burkhard Straube
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1996-07-25
Filing date: 1997-07-24
Publication date: 1999-06-23
Also published as: WO1998004463A1; DE19630103A1; KR20000029504A

Abstract

The invention concerns thermoplastic moulding materials which are different from ABS and which, in relation to the sum of the quantities of components A and B and optionally C and/or D resulting in a total of 100 wt %, contain a) 1-99 wt %, preferably 15-60 wt %, in particular 25-50 wt % of a particulate emulsion polymer with a glass transition temperature of less than 0 °C and a mean particle size of 50-1000 nm, preferably 50-500 nm as component A, b) 1-99 wt %, preferably 40-85 wt %, in particular 50-75 wt % of at least one amorphous or semi-crystalline polymer as component B, c) 0.50 wt % polycarbonate as component C and d) 0-50 wt % of fibre or particulate filling materials or their mixtures as component D. Said materials are used for producing heat-insulated transport containers.

Description

Thermally insulated transport containers

The invention relates to heat-insulated transport containers. In particular, the invention relates to heat-insulated transport containers which are both dimensionally stable and heat-resistant and also have good weather stability.

Heat-insulated transport containers are used, for example, where ready-made tubs or cold dishes have to be transported to the consumer. Their areas of application are therefore in the social sector, as well as in the catering and food sector. Due to the increasing delivery of packaged, warm, ready-to-eat dishes from the preparer to the consumer, there is an increased demand for suitable thermally insulated transport containers which have a property profile suitable for this use.

Different materials are used for the production of heat-insulated transport containers, for example for the transport of food, especially warm prepared dishes.

For example, polypropylene is used, but it has a low glass temperature and shows significant softening even at temperatures around 50 ° C. This means that there is insufficient dimensional stability at insulating material temperatures, which can be around 80 ° C for food, for example. In addition, polypropylene has an unfavorable toughness / rigidity ratio. The mechanical strength suffers after prolonged exposure to heat and is then insufficient. Insulated transport containers Polypropylene have insufficient scratch resistance and insufficient dimensional accuracy of the parts.

HIPS (High Impact PolyStyrene) is used as another material. It shows a lack of mechanical strength when exposed to heat for a long time, since the strength drops after continued heat storage. In addition, the weather stability is insufficient.

The object of the present invention is to provide heat-insulated transport containers which are dimensionally stable and have good dimensional stability.

Another object of the invention is to provide heat insulated shipping containers which are light in weight but still stable.

Another object of the invention is to provide heat-insulated transport containers which can be heat-loaded without losing strength.

Another object of the invention is to provide heat-insulated transport containers which have high weather stability.

Another object of the present invention is to provide heat-insulated transport containers which have properties which are superior to the transport containers used hitherto.

According to the invention, these objects are achieved by using a thermoplastic molding composition other than ABS, containing, based on the Sum of the amounts of components A and B, and if appropriate C and / or D, which gives a total of 100% by weight,

a: 1-99% by weight of a particulate emulsion polymer with a glass transition temperature below 0 ° C. and an average particle size of 50-1000 nm as component A,

b: 1-99% by weight of at least one amorphous or partially crystalline polymer as component B,

c: 0-50% by weight of polycarbonates as component C, and

d: 0 - 50% by weight of fibrous or particulate fillers or mixtures thereof as component D.

for the production of heat-insulated transport containers.

The heat-insulated transport containers according to the invention are dimensionally stable, heat-resistant and very weather-resistant. They have a low weight with great stability. They also have good chemical resistance and high scratch resistance.

The thermoplastic molding compositions used according to the invention for producing the heat-insulated transport containers according to the invention are known per se. For example, 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 Molding compositions which can be used according to the invention are described.

The molding materials other than ABS used for the production of the heat-insulated transport containers according to the invention include according to one embodiment, hold the components A and B listed below and possibly C and / or D as defined below. They contain, based on the sum of the amounts of components A and B, and if appropriate C and / or D, which gives a total of 100% by weight,

a: 1-99% by weight, preferably 15-60% by weight, in particular

25-50% 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 50-500 nm, as component A.

b: 1-99% by weight, preferably 40-85% by weight, in particular

50-75% by weight of at least one amorphous or partially crystalline polymer as component B.

c: 0-50% by weight of polycarbonates as component C, and

d: 0 - 50% by weight of fibrous or particulate fillers or their mixtures as component D.

The invention is explained in more detail below.

The molding compositions used to produce the heat-insulated transport containers according to the invention and the components from which they are constructed are first described.

COMPONENT A Component A is a particulate emulsion polymer with a glass transition temperature below 0 ° C and an average particle size of 50-1000 nm.

Component A is preferably a graft copolymer

al: 1-99% by weight, preferably 55-80% by weight, in particular

55-65% by weight, of a particulate graft base AI with a glass transition temperature below 0 ° C,

a2: 1-99% by weight, preferably 20-45% by weight, in particular 35-

45% by weight of a graft A2 composed of the monomers, based on A2,

a21: 40-100% by weight, preferably 65-85% by weight, units of a vinylaromatic 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

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.

The graft pad A2 consists of at least one graft shell, the graft copolymer A overall having an average particle size of 50-1000 nm. According to one embodiment of the invention, component AI consists of the monomers

all: 80-99.99% by weight, preferably 95-99.9% by weight, of a C _j . Alkyl esters of acrylic acid, preferably n-butyl acrylate and / or ethylhexyl acrylate as component All,

al2: 0.01-20% by weight, preferably 0.1-5.0% by weight, of at least one polyfunctional crosslinking monomer, preferably diallyl phthalate and / or DCPA as component A12.

According to one embodiment of the invention, the average particle size of component A is 50-800 nm, preferably 50-600 nm.

According to a further embodiment of the invention, the particle size distribution of component A is bimodal, 60-90% by weight having an average particle size of 50-200 nm and 10-40% by weight having an average particle size of 50-400 nm 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 mean 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 25Q (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 of the particles have a diameter equal to or smaller than a certain size. The average particle diameter, which is also called d ₅₀ value of the integral mass distribution is defined 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. To characterize the breadth of the particle size distribution of the rubber particles in addition to the _d50 value (median particle diameter) which are selected from the integral mass distribution are d ₁₀ - d ^ and used values. The d ₁₀ or d ^ 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

^d 9Q ~ ^d ιo

= Q

* 50

represents a measure of the distribution width of the particle size. Emulsion polymers A which can be used according to the invention as component A preferably have Q values less than 0.5, in particular less than 0.35.

The glass transition temperature of the emulsion polymer A and also of the other components used according to the invention is determined by means of DSC (Differential Scanning Calorimetry) according to ASTM 3418 (mid point temperature).

Relevant common rubbers can be used as emulsion polymer A, such as epichlorohydrin rubbers, ethylene-vinyl acetate rubbers, polyethylene chlorosulfone rubbers, silicone rubbers, polyether rubbers, hydrogenated diene rubbers, polyalkylene rubber rubbers, polyalkylene rubber rubbers, polyalkylene rubber rubbers, according to one embodiment of the invention. Ethylene propylene diene rubbers, butyl rubbers and fluororubbers. Acrylate rubber, ethylene-propylene (EP) rubber, ethylene-propylene-diene (EPDM) rubber, in particular acrylate rubber, are preferably used.

Pure butadiene rubbers, such as those used in ABS, cannot be used as exclusive component A.

According to one embodiment, the diene basic building block content in the emulsion polymer A is kept so low that as few unreacted double bonds remain in the polymer. According to one embodiment, there are no basic diene building blocks in the emulsion polymer A.

The acrylate rubbers are preferably alkyl acrylate rubbers made from one or more C 1-6 alkyl acrylates, preferably C ₄ g 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 hard polymer-forming monomers, such as vinyl acetate, (Me_h) ac_yl nitrile, styrene, substituted styrene, methyl methacrylate or vinyl ether in copolymerized form.

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

Suitable crosslinking monomers are, for example, divinylbenzene, diallyl maleate, diallyl fumarate, diallyl phthalate, diethyl phthalate, triallyl cyanurate, triallyl isocyanurate, tricyclodecenyl acrylate, dihydrodicyclopentadienyl acrylate, triallyl phosphate, allyl acrylate, allyl methacrylate. Dicyclopentadienyl acrylate (DCPA) has proven to be a particularly favorable crosslinking monomer (cf. DE-C-12 60 135).

Suitable silicone rubbers can be, for example, crosslinked silicone rubbers composed of units of the general formulas R SiO, RSiO _{3 2} , R ₃ SiO _{1 2} and SiO _{2 4} , the radical R representing a monovalent radical. The amount of the individual siloxane units is such that for 100 units of the formula R ₂ SiO 0 to 10 mol units of the formula RSi ^, 0 to 1.5 mol units R ₃ SiO _{1 2} and 0 to 3 mol units 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 radical 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 of groups which can be attacked by free radicals, in particular vinyl, allyl, halogen, mercapto groups, preferably in amounts of 2-10 mol%, based on all radicals R. They can be prepared, for example, as in EP-A-0 260 558.

In some cases it may be appropriate to use an emulsion polymer A made from uncrosslinked polymer. All of the monomers mentioned above can be used as monomers for the production of these polymers. Preferred uncrosslinked emulsion polymers A are, for example, homopolymers and copolymers of acrylic acid esters, in particular n-butyl and ethylhexyl acrylate, and homopolymers and copolymers of ethylene, propylene, butyl lens, isobutylene, and poly (organosiloxanes), all with the proviso that they may be linear or branched.

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. <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, component A is a graft copolymer. The graft copolymers A of the molding compositions according to the invention have an average particle size d ₅₀ of 50-1000 nm, preferably 50-600 nm and particularly preferably 50-400 nm. These particle sizes can be achieved if A1 of this component A is used as the graft base Particle sizes of 50-350 nm, preferably 50-300 nm and particularly preferably 50-250 nm are used.

The graft copolymer A is generally one or more stages, i.e. a polymer composed of a core and one or more shells. The polymer consists of a basic stage (graft core) Al and one or - preferably - several stages * A2 grafted thereon, the so-called graft stages or graft shells.

One or more graft shells can be applied to the rubber particles by simple grafting or multiple step-wise grafting, each graft sheath having a different composition. In addition to the grafting monomers, polyfunctional crosslinking or reductive Monomers containing active groups are 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 multi-stage structure serves, inter alia, to achieve (partial) compatibility of the rubber particles A with the thermoplastic B.

Graft copolymers A are prepared, for example, by grafting at least one of the monomers A2 listed below onto at least one of the graft bases or graft core materials AI listed above. All of the polymers which are described above under emulsion polymers A are suitable as graft bases AI of the molding compositions according to the invention.

According to one embodiment of the invention, the graft base AI is composed of 15-99% by weight of acrylate rubber, 0.1-5% by weight of crosslinking agent and 0-49.9% by weight of one of the further monomers or rubbers indicated.

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-D_methyIstyrol, p-tert.-butylstyrene, o- and p-divinylbenzene and p-methyl-α-methylstyrene or C _r C ₈ -alkyl (meth) acrylics such as methyl methacrylate, ethyl methacrylate, methyl acrylate, Ethyl acrylate, n-butyl acrylate, s-butyl acrylate; styrene, α-methylstyrene, methyl methacrylate, in particular styrene and / or 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, are preferred, n- and isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n- and isopropyl methactylate, n- and isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, maleic acid, maleic anhydride and maleic anhydride and its derivative , for example .All yl- and Alylmaleinimide, such as methyl or phenylmaleinimide. Acrylonitrile and methacrylonitrile, in particular acrylonitrile, are preferred.

Vinyl naphthalene, vinyl carbazole;; ₁₂ -alkyl radicals, halogen atoms, halomethyl groups can continue as (co) monomers styrene, vinyl, acrylic or methacrylic compounds (eg, styrene, optionally substituted with C ₁ _j vinyl ether with C ^ - ether radicals;.. 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 anhydrides, amides, 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 50-90% by weight of the above-described graft base AI and 10-50% by weight of the above-described graft base A2, based on the total weight of component A.

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

In a preferred embodiment, the graft A2 consists of at least one graft shell and the outermost graft shell thereof has a glass transition temperature of more than 30 ° C, a polymer formed from the monomers of the graft A2 would have a glass transition temperature of more than 80 ° C.

With regard to the measurement of the glass transition temperature and the average particle size and the Q values, what has been said for the emulsion polymers A applies to the graft copolymers A.

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

Suitable preparation processes for graft copolymers A are emulsion, solution, bulk or suspension polymerization. The graft copolymers A are preferably prepared by radical emulsion polymerization, in particular in the presence of latices of component AI at temperatures from 20 ° C. to 90 ° C. using water-soluble or oil-soluble initiators such as peroxodisulfate or benzyl peroxide, or with the aid of redox mitiators. Redox mitiators are also suitable for polymerization below 20 ° C.

Suitable emulsion polymerization processes are described in DE-A-28 26 925, 31 49 358 and in DE-C-12 60 135. The graft casings are preferably constructed in the emulsion polymerization process, as described in DE-A-32 27 555, 31 49 357, 31 49 358, 34 14 118. The defined particle sizes of 50-1000 nm according to the invention are preferably carried out after the processes that are 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 AI is first prepared by adding the acrylic acid ester (s) used according to one embodiment of the invention and the multifunctional monomers which bring about crosslinking, if appropriate together with the other comonomers, in an aqueous emulsion in a conventional manner at temperatures between 20 and 100 ° C, preferably between 50 and 80 ° C, polymerized. The usual emulsifiers, such as alkali metal salts of alkyl or alkylarylsulphonic acids, alkyl sulphets, fatty alcohol sulphonates, salts of higher fatty acids with 10 to 30 carbon atoms or resin soaps can be used. The sodium salts of alkyl sulfonates or fatty acids with 10 to 18 carbon fat atoms are preferably used. According to one embodiment, the emulsifiers are used in amounts of 0.5-5% by weight, in particular 1-2% by weight, based on the monomers used in the preparation of the graft base AI. In general, the weight ratio of water to monomers is from 2: 1 to 0.7: 1. The usual persulfates, such as potassium persulfate, are used in particular as polymerization initiators. However, redox systems can also be used. The initiators are generally used in amounts of 0.1-1% by weight, based on the monomers used in the preparation of the graft base AI. _* The usual buffer substances can be used as further polymerization aids which pH values of preferably 6-9 are set, such as sodium bicarbonate and sodium pyrophosphate, and 0-3% by weight of a molecular weight regulator, such as mercaptans, terpinols or dimeric α-methylstyrene, are used in the polymerization.

The precise polymerization conditions, in particular the type, dosage and amount of the emulsifier, are determined in detail within the ranges given above in such a way that the latex of the crosslinked acrylic ester polymer obtained has a __5 ₀ value in the range of about 50-1000 nm, preferably 50-150 nm, particularly preferably in the range of 80-100 nm. The particle size distribution of the latex should preferably be narrow. The quotient

» ^{~ D} \ 10

= Q

* 50

should be <0.5, preferably <0.35.

To produce the graft polymer A, a monomer mixture of styrene and acrylonitrile is then polymerized in a next step in the presence of the latex of the crosslinked acrylic ester polymer thus obtained, the weight ratio of styrene to acrylonitrile in the monomer mixture according to one embodiment of the invention in the range from 100: 0 to 40:60, preferably in the range from 65: 35 to 85: 15. It is advantageous to carry out this graft copolymerization of styrene and acrylonitrile on the crosslinked polyacrylic acid copolymer used as the graft base again in aqueous emulsion under the customary 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 AI, wherein, if necessary, further emulsifier and initiator can be added. The monomer mixture of styrene and acrylonitrile to be grafted on according to one embodiment of the invention can be added to the reaction mixture all at once, batchwise in several stages or preferably 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 20-45% by weight, in particular 35-45% by weight, based on the Total weight of component A, resulting in graft copolymer A. Since the graft yield in the graft copolymerization is not 100%, a somewhat larger amount of the monomer mixture of styrene and acrylonitrile must be used in the graft copolymerization than corresponds to the desired degree of grafting. 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 and can be carried out, for example, by the metering rate of the monomers or by adding a regulator (Chauvel, Daniel, ACS Polymer Preprints 15 (1974), page 329 ff .). The emulsion graft copolymerization generally gives rise to about 5 to 15% by weight, based on the graft copolymer, of free, non-grafted styrene / acrylonitrile copolymer. The proportion of the graft copolymer A in the polymerization product obtained in the graft copolymerization is determined by the method given above.

In the preparation of the graft copolymers A by the emulsion process, in addition to the process-related advantages which are given, reproducible changes in particle size are also possible, for example by at least partially agglomerating the particles into larger particles. This means that polymers with different particle sizes can also be present in the graft copolymers A. Component A, in particular, consisting of the graft base and graft shell (s) can be optimally adapted for the particular application, in particular with regard to the particle size.

The graft copolymers A generally contain 1-99% by weight, preferably 55-80 and particularly preferably 55-65% by weight of graft base AI and 1-99% by weight, preferably 20-45, particularly preferably 35-45% by weight .-% of the graft A2, each based on the entire graft copolymer.

COMPONENT B

Component B is an amorphous or teU crystalline polymer. Component B is preferably a copolymer of

bl: 40-100% by weight, preferably 60-70% by weight, units of a vinylaromatic monomer, preferably styrene, a substituted styrene or a (meth) acrylic acid ester or mixtures thereof, in particular styrene and / or α-methylstyrene as component Bl,

b2: up to 60% by weight, preferably 30-40% by weight, of units of an ethylenically unsaturated monomer, preferably acrylonitrile or methacrylonitrile, in particular acrylonitrile as component B2.

According to a preferred embodiment of the invention, the viscosity number of component B is 50-90, preferably 60-80. The amorphous or partially crystalline polymers of component B of the molding composition used according to the invention for producing the heat-insulated transport containers according to the invention are preferably composed of at least one polymer made from partially crystalline polyamides, partially aromatic copolyamides, polyolefins, ionomers, polyesters, polyether ketones, polyoxyalkylenes, polyarylene sulfides and polymers vinyl aromatic monomers and / or ethylenically unsaturated monomers selected. Polymer mixtures can also be used.

Component B of the molding composition used according to the invention for producing the heat-insulated transport containers according to the invention are partially crystalline, preferably linear polyamides such as polyamide-6, polyamide-6,6, polyamide-4,6, polyamide-6,12 and partially crystalline copolyamide based on these components . Furthermore, partially crystalline polyamides can be used, the acid component of which consists 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 a cyclohexanedicarboxylic acid, and whose diamine component wholly or partly consists in particular of m- and / or p-xylylenediamine and / or hexamethylenediamine and / or 2,2,4- and / or 2,4,4-trimethylhexamethylenediamine and / or isophoronediamine, and their compositions are known in principle from the prior art (cf. Encyclopedia of Polymers, Vol. 11, p. 315 ff.).

Examples of polymers which are furthermore suitable as component B of the molding compositions used according to the invention for producing the heat-insulated transport containers according to the invention are 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, poly propylene, polybutene-1 or poly-4-methylpentene-1. In general, a distinction is made between 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, in particular polyethylene, which contain monomers co-condensed with acid groups, for example acrylic acid, methacrylic acid and optionally further copolymerizable monomers. The acid groups are generally converted into ionic, possibly ionically crosslinked polyolefins with the aid of metal ions such as Na ⁺ , Ca ²⁺ , Mg ² and Al ³⁺ , but these 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. Component B according to the invention is also suitable for polyolefins containing free acid groups, which then generally have a rubber-like character and in some cases also contain further copolymerizable monomers, for example (meth) acrylates.

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

Aromatic polyether ketones can also be used as component B, as described, for example, in GB 1 078 234, US Pat. No. 4,010,147, EP-A-0 135 938, EP-A-0 292 211, EP-A-0 275 035, EP-A-0 270 998, EP 165 406, and in the publication by CK Sham et. al., Polymer 2 £ / 6, 1016-1020 (1988). Furthermore, component ox of the molding compositions used according to the invention for the production of the heat-insulated transport containers according to the invention may be pol oxyalkylenes, for example polyoxymethylene, and oxymethylene polymers.

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

According to one embodiment of the invention, it is composed of 50-99% by weight of vinyl aromatic monomers and 1-50% by weight of at least one of the other specified monomers.

Component B is preferably an amorphous polymer, as described above as graft A2. According to one embodiment of the invention, a copolymer of styrene and / or α-methylstyrene with acrylonitrile is used as component B. The acrylonitrile content in these copolymers of component B is 0-60% by weight, preferably 30-40% by weight, based on the total weight of component B. Component B also includes those used in the graft copolymerization to prepare the component A free, non-grafted styrene / acrylonitrile copolymers formed. Depending on the conditions chosen for the production of the graft copolymer A in the graft copolymerization, it may be possible that a sufficient proportion of component B has already been formed in the graft copolymerization. In general, however, it will be necessary to mix the products obtained in the graft copolymerization with additional, separately prepared component B.

This additional, separately produced component B can preferably be a styrene / acrylonitrile copolymer, an α-methylstyrene / acrylonitrile copolymer or an α-methylstyrene / styrene / acrylonitrile terpoly- act merisat. These copolymers can be used individually or as a mixture for component B, so that the additional, separately prepared component B of the molding compositions used according to the invention is, for example, a mixture of a s yrol / acrylonitrile copolymer and an α-methylstyrene / Acrylonitrile copolymer can act. In the event that component B of the molding compositions used according to the invention consists of a mixture of a styrene / acrylonitrile copolymer and an α-methylstyrene / acrylonitrile copolymer, the acrylonitrile content of the two copolymers should preferably not be more than 10% by weight. %, preferably not more than 5% by weight, based on the total weight of the copolymer, differ from one another. Component B of the molding compositions used according to the invention can, however, also consist of only a single styrene / acrylonitrile copolymer if, in the graft copolymerizations for the production of component A and also in the production of the additional, separately produced component B, the same monomer mixture of styrene and acrylonitrile is assumed.

The additional, separately manufactured component B can be obtained by the conventional methods. Thus, according to one embodiment of the invention, the copolymerization of the styrene and / or α-methylstyrene with the acrylonitrile can be carried out in bulk, solution, suspension or aqueous emulsion. Component B preferably has a viscosity number of 40 to 100, preferably 50 to 90, in particular 60 to 80. The viscosity number is determined in accordance with DIN 53 726, 0.5 g of material being dissolved in 100 ml of dimethylformamide.

Components A and B and optionally C, D can be mixed in any desired manner by all known methods. If components A and B have been prepared, for example, by emulsion polymerization, it is possible to use the polymer dispersions obtained to mix with one another, then to precipitate the polymers together and to work up the polymer mixture. However, components A and B are preferably mixed by extruding, kneading or rolling the components together, the components having, if necessary, been isolated beforehand from the solution or aqueous dispersion obtained in the polymerization. The products of the graft copolymerization (component A) obtained in aqueous dispersion can also only be partially dewatered and mixed with component B as a moist crumb, the graft copolymers then being completely dried during the rushing.

In a preferred embodiment, the molding compositions used to produce the heat-insulated transport containers according to the invention contain, in addition to components A and B, additional components C and / or D and, if appropriate, further additives, as described below.

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. They can be obtained, for example, in accordance with the processes of DE-B-1 300 266 by interfacial polycondensation or in accordance with the process of DE-A-1 495 730 by reacting 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, in particular 2,2-di (4-hydroxyphenyl) pentane, 2,6-dihydroxynaphthalene, 4,4'-dihydroxydiphenylsulfane, 4,4'-dihydroxydiphenyl ether, 4 , 4'-dihydroxydiphenyl sulfite, 4,4'-dihydroxydiphenylmethane, l, l-di- (4-hydroxyphenyI) ethane, 4,4-dihydroxydiphenyl or dihydroxydiphenylcycloalkanes, preferably dihydroxydiphenylcyclohexanes or dihydroxylcyclopentanes, in particular l, l-B_s (4- hydroxyphenyl) -3,3,5-_rime_hylcyclohexan and mixtures 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 aromatic dihydroxy compounds mentioned above.

Copolycarbonates according to US Pat. No. 3,737,409 can also be used; Of particular interest are copolycarbonates based on bisphenol A and di- (3,5-dime yl-dihydroxyphenyI) sulfone, which are characterized by a high heat resistance. It is also possible to use mixtures of 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% 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. They are present as component C in amounts of 0-50% by weight, preferably 10-40% by weight, based in each case on the total molding composition.

According to one embodiment of the invention, the addition of polycarbonates leads, inter alia, to higher thermostability and improved crack resistance of the molding compositions used according to the invention for producing the heat-insulated transport containers according to the invention.

COMPONENT D

The preferred thermoplastic molding compositions used according to the invention for producing the heat-insulated transport containers according to the invention contain, as component D, 0 to 50% by weight, preferably 0 to 40% by weight, in particular 0 to 30% by weight of fibrous or particulate fillers or mixtures thereof based on the total molding compound. These are preferably commercially available products.

Reinforcing agents such as carbon fibers and glass fibers are usually used in amounts of 5-50% by weight, based on the total molding composition.

The glass fibers used can be made of E, A or C glass and are preferably equipped with a size and an adhesion promoter. Their diameter is generally between 6 and 20 μm. Both continuous fibers (rovings) and chopped glass fibers (staples) with a length of 1-10 μm, preferably 3-6 μm, can be used. Furthermore, fillers or reinforcing materials such as glass balls, mineral fibers, whiskers, aluminum oxide fibers, mica, quartz powder and wollastonite can be added.

In addition, metal flakes (e.g. aluminum flakes from Transmet Corp.), metal powder, metal fibers, metal-coated fillers, e.g. nickel-coated glass fibers and other additives that shield electromagnetic waves are mixed with the molding materials used according to the invention for the production of the heat-insulated transport containers according to the invention. Aluminum flakes (K 102 from Transmet) are particularly suitable for EMI purposes (electro-magnetic interference). Furthermore, the materials can be mixed with additional carbon fibers, carbon black, in particular conductivity carbon black, or nickel-coated carbon fibers.

The molding compositions used according to the invention for the production of the heat-insulated transport containers according to the invention may also contain other additives which are typical and customary for polycarbonates, SAN polymers and graft copolymers or mixtures thereof. Examples of such additives are: dyes, pigments, colorants, antistatics, antioxidants, stabilizers to improve thermostability, to increase light stability, to increase resistance to hydrolysis and chemicals, to prevent heat decomposition and in particular to lubricants. / Lubricants that are useful for the production of moldings or molded parts. These additional additives can be metered in at any stage of the production process, but preferably at an early point in time, in order to take advantage of the stabilizing effects (or other special effects) of the additive at an early stage. Heat stabilizers or oxidation retardants are usually metal halides (chlorides, bromides, iodides) which are derived from metals of group I of the periodic table of the elements (such as Li, Na, K, Cu). Suitable stabilizers are the usual hindered phenols, but also vitamin E or compounds with an analog structure. HALS stabilizers (hindered amine light stabilizers), benzophenones, resorcinols, salicylates, benzotriazoles and other compounds are also 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-methylphenol), topanol). These are usually used in amounts of up to 2% by weight (based on the total mixture).

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

Silicone oils, oligomeric isobutylene or similar substances are also suitable as additives, the usual amounts being 0.05-5% by weight. Pigments, dyes, color brighteners such as ultramarine blue, phthalocyanines, titanium dioxide, cadmium sulfides, derivatives of perylene tetracarboxylic acid can also be used.

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 composition.

The thermoplastic molding compositions used for the production of the heat-insulated transport containers according to the invention can be produced by methods known per se by mixing the components. It can be advantageous to premix individual components. Mixing the components in solution and removing the solvents is also possible. Suitable organic solvents are, for example, chlorobenzene, mixtures of chlorobenzene and methylene chloride or mixtures of chlorobenzene or aromatic hydrocarbons, for example toluene.

The solvent mixtures can be evaporated, for example, in evaporation extruders.

Mixing the e.g. dry components can be made by all known methods. However, the mixing is preferably carried out by extruding, kneading or rolling the components together, preferably at temperatures of 180-400 ° C., the components having, if necessary, been isolated beforehand from the solution obtained in the polymerization or from the aqueous dispersion.

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

According to one embodiment of the invention, the heat-insulated transport containers according to the invention can be produced from the thermoplastic molding compositions used according to the known methods of thermoplastic processing. In particular, the production can be carried out by thermoforming, extrusion, injection molding, calendering, blow molding, pressing, press sintering, deep drawing or sintering, preferably by extrusion blowing.

The heat-insulated transport containers according to the invention that can be produced from the thermoplastic molding compositions described are scratch-resistant, stable and resistant to chemicals and have very good dimensional stability. They also have a low density and therefore a low weight. According to one embodiment of the invention, the heat-insulated transport containers according to the invention are multi-walled, in particular double-walled. The outer wall surfaces consist of the molding compound according to the invention, preferably also the inner wall surfaces. The inner wall surfaces form a cavity for receiving the objects to be transported. The space between the outer wall surfaces and the inner wall surfaces has a heat-insulating effect. For this purpose, the intermediate space can be evacuated or filled with a gas, for example air or an inert gas, a liquid, or a heat-insulating solid or foam.

According to a preferred embodiment, the cavity is filled with a macroscopic filler, preferably made of foamed polymer. A sandwich construction is thus formed, in which a layer of the themoplastic molding composition according to the invention is applied to both sides of the foamed polymer. All surface coatings are preferably formed from the thermoplastic molding composition. The heat-insulated transport container according to the invention can have any suitable shape. The container can thus have the shape of a sphere, a cube, a cuboid, a cylinder or another suitable shape. The container is designed so that it can be opened on at least one side for the insertion and removal of the objects to be transported or isolated. The container is preferably cuboid in shape and one of the sides is designed as a door or cover which, when closed, enables the interior to be thermally insulated.

The temperature range to be maintained in the heat-insulated transport container depends on the object to be picked up. According to one embodiment of the invention, the temperature range is -50 to + 100 ° C, preferably -30 to + 80 ° C. These temperature ranges are found in particular when transporting food, especially in the case of ready-made food. hot or cold dishes. The heat-insulated transport containers according to the invention are also suitable for holding and tempering liquids or beverages, for example in the form of packaged beverages such as beverage cans or beverage bottles.

The heat-insulated transport containers can also be used for the transport of medication or body organs that are intended for implantation and must be transported from the organ donor to the corresponding implantation site.

Typical heat-insulated transport containers according to the invention have an internal capacity of 1 to 500 liters, preferably 10 to 50 liters.

The transport containers according to the invention are provided for the transport of the picked up objects between different locations. According to one embodiment of the invention, the transport containers are used at least partially outdoors (outside buildings). This is the case, for example, in the case of food transports, in which prepared food is transported from the preparer to the consumer, usually by road vehicle. The transport containers according to the invention are exposed to external weathering for more or less long periods. For this reason, they must have good weather stability, which is maintained even with continued heat stress.

Other suitable uses of the heat-insulated transport containers according to the invention are known to the person skilled in the art.

Transport containers used for the transportation of organs, medication or food, in particular, must be kept clean and often come into contact with chemicals or cleaning agents. Which he- Heat-insulated transport containers according to the invention have good resistance to chemicals, in particular in environments where they are additionally exposed to moisture (such as water vapor).

In particular, heat-insulated transport containers made of molding compositions which contain polycarbonates as component C are very heat-resistant and resistant to lasting heat. By adding the polycarbonate as component C, the heat resistance and impact resistance of the heat-insulated transport containers are further improved. These heat-insulated transport containers also have a balanced ratio of toughness and rigidity and good dimensional stability, as well as excellent resistance to heat aging and high resistance to yellowing under thermal stress and exposure to UV radiation.

This use of the heat-insulated transport containers represents a further embodiment of the invention.

Heat-insulated transport containers made of molding compounds containing components A and B have excellent surface properties that can be obtained without further surface treatment. The appearance of the finished surfaces of the heat-insulated transport containers can be modified by suitable modification of the rubber morphology, for example in order to achieve glossy or matt surface designs. The heat-insulated transport containers show a very low graying or yellowing effect when exposed to weather and UV radiation, so that the surface properties are retained. Further advantageous properties of the heat-insulated transport containers are the high weather stability, good thermal resistance, high yellowing resistance under UV radiation and thermal stress, good tension Crack resistance, especially when exposed to chemicals, and good anti-electrostatic behavior. In addition, they have high color stability, for example due to their excellent resistance to yellowing and embrittlement. The wall elements according to the invention made of the thermoplastic molding compositions used according to the invention do not show any significant loss of toughness or impact strength at low temperatures or after prolonged exposure to heat, which loss is retained even when exposed to UV rays. The tensile strength is also retained. They also show a balanced relationship between rigidity and toughness.

It is possible to recycle the thermoplastic molding compositions already used to produce the heat-insulated transport containers according to the invention. Because of the high color stability, weather resistance and aging resistance, the molding compositions used according to the invention are very suitable for reuse. The proportion of reused (recycled) molding compound can be high. When using, for example, 30% by weight of molding compound already used, which was mixed in the ground form with the molding compounds used according to the invention, the relevant material properties, such as flowability, Vicat softening temperature and impact strength of the molding compounds and the heat-insulated transport containers according to the invention produced therefrom changed not significant. Similar results were obtained when the weather resistance was examined. The impact strength was constant for a long time even when using recycled thermoplastic molding compositions, see Lindenschmidt, Rupp-mich, Hoven-Nievelstein, International Body Engineering Conference, September 21-23, 1993, Detroit, Michigan, USA, Interior and Exterior Systems, Pages 61 to 64. The yellowing resistance was also retained. The invention is illustrated by the following examples.

EXAMPLES

example 1

Production of small-part graft copolymer (A)

(al) 16 parts of butyl acrylate and 0.4 part of tricyclodecenyl acrylate were in 150 parts of water with the addition of part of the sodium salt of a C ^ - to C ₁₈ paraffinsulfonic acid, 0.3 part of potassium persulfate, 0.3 part of sodium hydrogen carbonate and 0.15 part 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 had been added, 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).

(a2) 150 parts of the polybutyl acrylate latex obtained according to (al) were mixed with 40 parts of a mixture of styrene and acrylonitrile (weight ratio 75:25) and 60 parts of water and with stirring after the addition of a further 0.03 part of potassium persulfate and 0.05 parts of lauroyl peroxide heated to 65 ° C for 4 hours. After the end of the graft copolymerization, the polymerization product was removed from the dispersion by means of calcium chloride solution at 95 ° C. precipitated, washed with water 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)

(al) 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 -paraf__r_sulfonic acid in 25 parts of water at 60 ° C. After the end of the feed, polymerization was continued for 2 hours. The obtained latex of the cross-linked

Butyl acrylate polymers 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).

(a2) 150 parts of this latex were mixed with 40 parts of a mixture of styrene and acrylonitrile (ratio 75:25) and 110 parts of water and with stirring after the addition of a further 0.03 part of potassium persulfate and 0.05 part of lauroyl peroxide to 65 for 4 hours ° C heated. The polymerization product obtained in the graft copolymerization was then precipitated from the dispersion using a calcium chloride solution at 95 ° C., separated off, washed with water and dried in a warm air stream. The degree of grafting of the graft copolymer was determined to be 27%. Example 3

Production of large-scale graft copolymer (A)

(al) 16 parts of butyl acrylate and 0.4 part of tricyclodecenyl acrylate were dissolved in 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 are heated to 60 ° C. with stirring. 10 minutes after the start of the polymerization reaction was carried out within

A mixture of 82 parts of butyl acrylate and 1.6 parts of tricyclodecenyl acrylate was added for 3 hours. After the monomer had been added, 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).

(a2) 150 parts of the polybutyl acrylate latex obtained according to (al) were mixed with 20 parts of styrene and 60 parts of water and mixed under

Stirring, after addition of a further 0.03 part of potassium persulfate and 0.05 part of lauroyl peroxide was heated for 3 hours at 65 C ^β. After the first stage of the graft copolymerization had ended, the graft copolymer had a degree of grafting of 17%. This graft copolymer dispersion was at 20

Part of a mixture of styrene and acrylonitrile (ratio 75:25) polymerized for a further 3 hours. After the graft copolymerization had ended, the product was precipitated from the dispersion using calcium chloride solution at 95 ° C., washed with water and dried in a warm air stream. The degree of grafting of the graft mix polymer was 35%, the average particle size of the latex particles was found to be 238 nm.

Example 4

Production of large-scale graft copolymer (A)

(al) On the one hand, a mixture of 49 parts of butyl acrylate and 1 part of tricyclodecenyl acrylate were added to a template from 2.5 parts of the latex produced in Example 3 (component A) after the addition of 50 parts of water and 0.1 part of potassium persulfate over the course of 3 hours and on the other hand, a solution of 0.5 part of the sodium salt of a C ₁₂ - to C ₁₈ -P__rafl_nsulfonic acid in 25 parts of water at 60 ° C. After the end of the feed, polymerization was continued for 2 hours. The obtained latex of the cross-linked

Butyl acrylate polymers 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).

(a2) 150 parts of the polybutyl acrylate latex obtained according to (a1) were mixed with 20 parts of styrene and 60 parts of water and heated with stirring after the addition of a further 0.03 part of potassium persulfate and 0.05 part of lauroyl peroxide to 65 ° C. for 3 hours. The dispersion obtained in this graft copolymerization was then polymerized with 20 parts of a mixture of styrene and acrylonitrile in a ratio of 75:25 for a further 4 hours. The reaction product was then precipitated from the dispersion using a calcium chloride solution at 95 ° C., separated off, washed with water and dried in a warm air stream. The degree of grafting of the graft mix The polymer was found to be 35%, the average particle size of the latex particles was 490 nm.

Example 5

Production of large-scale graft copolymer (A)

(al) 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 at 65 ° C. for 3 hours. 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 at 65 ° C. to an initial charge of 2.5 parts of this latex, 400 parts of water and 0.5 part of potassium persulfate 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 was added

Allocate emulsifier. 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 over the course of 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.

(a2) 465 parts of styrene and 200 parts of acrylonitrile were in the presence of 2500 parts of the polymer latex according to (al) with the mean 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. A 40% dispersion was obtained, from which the solid product was precipitated by adding a 0.5% calcium chloride solution, washed with water and dried.

Example 6

Production of copolymer ß)

A monomer mixture of styrene and acrylonitrile was polymerized in solution under customary conditions. The styrene / acrylonitrile copolymer obtained had an acrylonitrile content of 35% by weight, based on the copolymer, and a viscosity number of 80 ml / g.

Example 7

Production of copolymer (B)

A monomer mixture of styrene and acrylonitrile was polymerized in solution under customary conditions. The styrene / acrylonitrile copolymer obtained 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 monomer mixture of styrene and acrylonitrile was polymerized in solution under customary conditions. The styrene / acrylonitrile copolymer obtained had an acrylonitrile content of 27% by weight, based on the copolymer, and a viscosity number of 80 ml / g.

Comparative Example 1

ABS polymer

A polybutadiene rubber which was grafted with a styrene-acrylonitrile copolymer as component (A), which was present in a styrene-acrylonitrile copolymer matrix as component (B), was used as the comparative polymer. The graft rubber content was 23% by weight, based on the total weight of the finished polymer.

Comparative Example 2

HIPS pots

A HIPS polymer (high impact polystyrene: impact-resistant polystyrene), which consisted of polystyrene with a proportion of 6.5% by weight of polybutadiene rubber, was used as a further molding compound for comparison purposes. The damping maximum of the mechanical damping is -75 ° C. The MVI 200/5 is 4 ml 10 min. Comparative Example 3

PP polymer

As a further molding composition for comparison purposes, a block copolymer of PP and about 15 wt .-% of ethylene / propylene was - rubber used, the cm ^3/10 min having a melt viscosity MVI 230 / 2.16 =. 8 It has damping maxima at 0 ° C and -50 ° C.

It is used for injection molding processing.

Example 9

According to the information in Table 1 below, the stated amounts of the corresponding polymers (A) and (B) or the comparative masses are mixed in a screw extruder at a temperature of 200 ° C. to 230 ° C. Test specimens were produced from the molding compounds formed in this way using the method of DIN standard 16777. A molding composition according to the invention and the molding compositions of the 3 comparative examples were examined for their aging at 80 ° C. For this purpose, the puncture work (Nm according to ISO 6603-2 after 0,0,5,1 and 2 years was determined. A low puncture work means poor strength or rapid aging. In addition, the modulus of elasticity according to DIN 53 457 at 23 ° C and 50 ° C. Large values for the modulus of elasticity indicate good dimensional stability, and the HDT (heat distortion temperature) was also determined in accordance with DIN / ISO 75 with a load of 1.8 and 0, respectively , 45 MPa. The results are summarized in the table below:

Fornunasse KompoTle aging at 80 "C E-Modul HDT element from piercing in Nm according to DIN 53 457 for example according to ISO 6603-2 temperature

after years

0 0.5 1 2 23 ^β C 50 ^β C 1.8 "C 0.45 ° C MPa MPa

I A: l 25

A: 3 10 36 33 32 29 2300 2100 97 101

B: 6 10

B: 7 55

Compare I Compare 1 34 2 2 - 2700 2350 100 104

Comp. II Comp. 2 15 1.2 0.8 - 1850 1500 78 89

10 Comp. III Comp. 3 not checked 1250 700 52

"

The results of the table show that heat-insulated transport containers made from the molding composition according to the invention have a significantly higher penetration work after aging than the comparison compositions. They are therefore much more stable to aging and weather. The measurements of the modulus of elasticity and HDT show that they also have much better properties than the reference masses in terms of dimensional stability and heat resistance.

Claims

claims

1. Use of a thermoplastic molding composition different from ABS, containing, based on the sum of the amounts of components A and B, and optionally C and / or D, which gives a total of 100% by weight,

c: 0-50% by weight of polycarbonates as component C, and

d: 0 to 50% by weight of fibrous or particulate fillers or mixtures thereof as component D.

for the production of heat-insulated transport containers.

2. Use according to claim 1, characterized in that component A is a graft copolymer from

al: 1-99% by weight of a particulate graft base AI with a glass transition temperature below 0 ^β C,

a2: 1-99% by weight of a graft A2 from the monomers, based on A2, a21: 40-100 parts by weight of a vinyl aromatic monomer as component A21 and

a22: up to 60% by weight of units of an ethylenically unsaturated monomer as component A22

wherein the graft A2 consists of at least one graft shell and the graft copolymer A has an average particle size of 50-1000 nm.

3. Use according to claim 2, characterized in that the molding composition contains as a particulate graft base AI an acrylate, EP, EPDM or silicone rubber.

4. Use according to claim 3, characterized in that component AI consists of the monomers

all: 80-99.99% by weight of a C 1-6 alkyl ester of acrylic acid, as component All,

al2: 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, 60-90% by weight being an average particle size of 50-200 nm and 10-40% by weight being an average Have particle sizes of 50-400 nm, based on the total weight of component A.

6. Use according to one of claims 1 to 5, characterized in that the transport container serves to hold food, in particular ready-made warm or cold dishes.

7. Use according to one of claims 1 to 5, characterized in that the transport container serves to hold medicaments and / or body organs.

8. Use according to one of claims 1 to 7, characterized in that the transport containers at least partially in the outside area

(outside of buildings).

9. Heat-insulated transport container made of a thermoplastic molding material, as defined in one of claims 1 to 5.

10. Transport container according to claim 9, characterized in that it comprises outer wall surfaces and inner wall surfaces made of a thermoplastic molding composition as defined in one of claims 1 to 5, and a heat-insulating intermediate layer between the outer wall surfaces and inner wall surfaces, which is preferably a foamed

Includes polymer.