WO2004029151A1

WO2004029151A1 - Mixtures of propellant-free microgranulates

Info

Publication number: WO2004029151A1
Application number: PCT/EP2003/009947
Authority: WO
Inventors: Norbert Güntherberg; Bernhard Czauderna; Michael Sauer; Peter Barghoorn
Original assignee: Basf Aktiengesellschaft
Priority date: 2002-09-20
Filing date: 2003-09-08
Publication date: 2004-04-08
Also published as: AU2003258713A1; DE10243905A1; EP1543073A1

Abstract

The invention relates to a mixture comprising, A) at least one propellant-free microgranulate made from a moulding material with at least one homopolymer or copolymer of a vinylaromatic monomer or an (alkyl)acrylate and B) at least one thermoplastic, different from the moulding material used in component (A), in powder and/or granulate form.

Description

Mixtures of blowing agent-free microgranules

description

The present invention relates to a mixture which comprises A) at least one blowing agent-free microgranulate from a molding composition comprising at least one homopolymer or copolymer of a vinylaromatic monomer or a (alkyl) acrylate and B) an thermoplastic which differs from that in the component A) different molding compounds used, in powder or granular form, contains. Furthermore, the invention relates to blowing agent-free microgranules of a certain grain size. In addition, the invention relates to the use of blowing agent-free microgranules for the production of such mixtures and the use of the mixtures for the production of moldings, films or fibers and a process for their preparation.

Granules are plastic bodies that are created by dividing a plastic mass into plastic grains, e.g. by means of extrusion and subsequent strand or underwater pelletizing. Granules with small particle diameters are called microgranules.

EP-AI 733 677 discloses microgranules with a particle size in the range from 0.2 to 1.1 mm. These microgranules can be produced by mixing a styrene copolymer with a certain block copolymer and at least 7% by weight of a plasticizer in an extruder, pressing the molding compound through a nozzle of the appropriate size and then granulating it under water. Due to the high proportion of plasticizer, the microgranules have a very high level. low shore hardness. These powdery microgranules were specially developed to be used in the rotary melting process.

Microgranules were known from EP-A2 436 847, the size of which can be 2.54 mm or less. According to this document, they are produced by the strand pelletizing process. According to the disclosure, they can be produced from molding compositions from styrene copolymers which contain at least 1% by weight, for example at least 20% by weight, of polyphenylene ether. These microgranules are not used as such but are impregnated with a blowing agent and are then used to produce foamed moldings. Strand granulation has the disadvantage that the very thin strands required for the production of the microgranules break easily. This means that the strands are need to be threaded. Since this usually requires manual labor, this process is complex.

Micro-granules also emerge from document CA-Al 2,030,646, which are not used as such, but were specially developed for the production of foamed molded parts and are therefore first impregnated with a blowing agent after their production. They are also manufactured using strand pelletizing. Their particle size should be less than about 0.5 mm. According to the disclosure, the microgranules can be made of ABS or SAN and contain additives. The microgranules are preferably produced from a polymeric mixture which contains polyphenylene ether.

WO 00/73752 discloses a process for coloring thermoplastic polymers such as ABS or SAN. The dyes can be used in the form of microgranules. The microgranules can consist of a mixture of the dye and a polymer and are often referred to as master streams when the mixtures are highly concentrated. The microgranules are added to the polymers to be colored by adding the microgranules to a flow of polymer granules. The mixing conditions are chosen so that the microgranules soften and surround the polymer granules like a skin. This mixing process is commonly referred to as tumbling.

Mixtures of different thermoplastics are widespread because it is precisely by combining different thermoplastics that products with the desired property profile can be obtained. So-called dry mixtures of different thermoplastics, which are in the form of granules or powder, are often prepared so that they can be melted and processed into molded parts at a later date. When storing these dry mixtures or transporting them over longer distances, for example using compressed air or when repacking them, it often happens that the powders or granules of the various mixture components separate partially or completely. Ultimately, this means that only products of poor quality can be obtained from it. This can have considerable consequences for the safety of a molded part, for example, if it does not withstand impact stress equally well or shows chemical resistance. This is particularly true when it comes to molded parts, in particular large parts, that are used in household items, the automotive industry, in garden tools or toys. From DE-Al 34 05 651 powders were known which can be used for the production of mixtures with polyvinyl chloride. According to the disclosure, these powders are produced by spray drying aqueous dispersions of bimodally distributed emulsion polymers. The emulsion polymers are based on acrylic monomers. Their bulk density is typically between 350 and 550 g / 1. The powders have a small proportion of particles whose size is below 10 μm and have an average particle size between 20 to 500 μm. The production of powders from aqueous dispersions by means of spray drying is energy-intensive. In addition, for safety reasons (dust explosion), powders are sought today, the proportion of particles of which are smaller than 500 μ is as low as possible.

The object of the present invention was therefore to find dry mixtures of different thermoplastics which have a homogeneous distribution of the different thermoplastics until the dry mixture is processed. For example, the dry mixes should be transportable over longer distances, e.g. using compressed air without segregating. The dry mixes should also be repackable or storable over a longer period of time without there being any fluctuations in their composition. It was also a goal to find dry mixtures whose residual monomer and fine dust content was as low as possible. Another aim was to provide dry mixtures which can be used particularly advantageously in the production of molded parts by means of the roll mill process or calendering.

These tasks are fulfilled by the mixtures defined at the beginning.

Component A)

The mixtures according to the invention contain at least one blowing agent-free microgranulate as component A). They can also contain a mixture of two or more, for example three or more, such as three to ten microgranules, which differ from one another in that they are made from different molding compositions. It is also possible for component A) to consist of a mixture of two or more, for example three or four, microgranules, which are made of the same molding compound, but differ in that they have different grain sizes or a different distribution of the grain sizes. Of course, it is also possible for the two or more, for example three or more, such as three to ten microgranules to differ from one another both in that they are both from a different molding compound and also have different grain sizes and / or distribution widths of the grain size. A microgranulate or a mixture of two different microgranules, in particular one microgranulate, are preferably used as component A) in the mixtures according to the invention.

In general, the microgranules have grain sizes in the range from 0.5 to 2.5 mm. The grain sizes can also be slightly above or below. Have preferred microgranules

Grain sizes from 0.6 to 2.5 mm. According to a further embodiment of the invention, the distribution of the grain size of the microgranules is narrow. Microgranules which have a proportion of 50% by weight or more particles and whose grain sizes are in the range from 1 to 1.6 mm are preferred.

The grain sizes are determined using dry sieve analysis in accordance with DIN 53477. The amount of screenings is 300 g each. The sieve set used in the examples is used. Otherwise, the procedure is as specified in DIN 53477. Accordingly, the term grain size means the equivalent diameter of the same-volume sphere and corresponds to the nominal width of the test sieve opening.

Microgranules which have an essentially identical shape can be used as component A) or a mixture of two or more, for example three or four, microgranules which differ from one another in terms of their shape can be used. The microgranules can, for example, be round, ellipsoidal, cube-shaped or cylindrical. Mixtures in which the microgranules are of different molding compositions and / or different grain sizes and / or different distribution widths of the grain sizes and differ in their shape from one another can also be used. The microgranules from a molding compound are particularly preferred and are round to ellipsoidal.

The microgranules can have a wide variety of bulk densities. Microgranules with bulk densities of 550 to 700 g / 1 are preferred, preferably 600 to 700 g / 1. The bulk density is determined by filling a measuring cylinder with the microgranules up to one liter at room temperature and then weighing this amount of microgranules. According to the invention, the microgranules can be made from a molding composition which contains at least one homopolymer of a vinylaromatic monomer. Preferred vinyl aromatic monomers are styrene compounds of the general formula I

with: R ¹ , R ² : independently of one another H or

Ci-Ce-alkyl n: 0, 1, 2 or 3,

The styrene compound of the general formula (I) used is preferably styrene, .alpha.-methylstyrene and, moreover, styrenes which are core-alkylated with C 1 -C 6 -alkyl, such as p-methylstyrene or t-butylstyrene. Styrene is particularly preferred. Mixtures of the styrenes mentioned, in particular styrene and α-methylstyrene, can also be used. Styrene is particularly preferably used.

According to one of the preferred embodiments, the homopolymers can be impact-modified, of which the so-called HIPS is particularly preferred.

In addition, component A can also be a microgranulate which is produced from a molding composition which contains a homo- or copolymer of an acrylate and / or alkylarylate, for example a C 1 -C 4 -alkyl acrylate, in particular a polymethyl methacrylate. The polymethyl methacrylate can be both a homoal and a copolymer. The copolymer comes e.g. a copolymer based on the monomers methyl methacrylate and methyl acrylate.

According to the invention and particularly preferably, the microgranules can also be made from a molding composition which contains at least one copolymer of a vinylaromatic monomer. These include copolymers with one or two or more, for example three to ten, other monomers. Suitable copolymers are, for example, linear, branched, block copolymers or graft copolymers.

Mixtures of the copolymers mentioned, for example mixtures of linear and graft copolymers, are also suitable. In a preferred embodiment, the copolymer is composed, based on the copolymer

al) 50 to 99% by weight of a styrene compound of the general formula I

a2) 1 to 50 wt .-% acrylonitrile or methacrylonitrile or mixtures thereof, and

a3) 0 to 40% by weight of one or more further monoethylenically unsaturated monomers different from a2).

In a mixture with the styrene compound, ci- to Cs-alkyl esters of acrylic acid and / or methacrylic acid are suitable, especially those which differ from methanol, ethanol, n- and iso-propanol, s-, t- and iso-butanol, pentanol, Derive hexanol, heptanol, octanol, 2-ethylhexanol and n-butanol. Methyl methacrylate is particularly preferred.

Furthermore, the copolymer can contain one or more further monoethylenically unsaturated monomers a3) at the expense of the monomers al) and a2). Examples of such comonomers are:

N-substituted maleimides such as N-methyl, N-phenyl and N-cyclohexyl maleimide;

Acrylic acid, methacrylic acid, furthermore dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and their anhydrides such as maleic anhydride;

Nitrogen-functional monomers such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate, vinylidazole, vinylpyrrolidone, vinylcaprolactam, vinylcarbazole, vinylaniline, acrylamide and methacrylamide;

aromatic and araliphatic esters of acrylic acid and methacrylic acid such as phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 2-phenoxyethyl acrylate and 2-phenoxyethyl methacrylate;

unsaturated ethers such as vinyl methyl ether,

as well as mixtures of these monomers. Preferred copolymers are, for example, copolymers of styrene and / or α-methylstyrene and one or more of the other monomers mentioned under a1) to a3). Methyl methacrylate, N-phenyl maleimide, maleic anhydride and acrylonitrile are preferred, methyl methacrylate and acrylonitrile being particularly preferred.

Examples of preferred copolymers are:

A / l copolymer of styrene and acrylonitrile,

A / 2 copolymers from α-methylstyrene and acrylonitrile, A / 3 copolymers from styrene and methyl methacrylate.

The proportion of styrene or α-methylstyrene, or the proportion of the sum of styrene and α-methylstyrene, is particularly preferably at least 40% by weight, based on the copolymers. Copolymers of styrene and acrylonitrile (SAN) and α-methylstyrene and acrylonitrile are particularly preferred.

They generally have a viscosity number VZ (determined according to DIN 53 726 at 25 ° C, 0.5% by weight in dimethylformamide) of 40 to 160 ml / g, corresponding to an average molar mass of approximately 40,000 to 2,000,000 (weight average ).

According to a further preferred embodiment, the copolymers can contain up to 50% by weight, based on the overall composition, of graft copolymers based on a rubber-elastic polymer.

In principle, all rubber-elastic polymers with a glass transition temperature Tg of 0 ° C. or below (Tg determined by means of differential scanning calorimetry (DSC) according to DIN 53765) are suitable as such, in particular those which are used as rubber

a diene rubber based on dienes, e.g. Butadiene or isoprene,

an alkyl acrylate rubber based on alkyl esters of acrylic acid, such as n-butyl acrylate and 2-ethylhexyl acrylate,

an EPDM rubber based on ethylene, propylene and a diene,

a silicone rubber based on polyorganosiloxanes, or mixtures of these rubbers or rubber monomers.

Graft polymers of a basic stage and a graft stage are preferred.

Preferred graft polymers contain, based on the graft polymers,

αl) 30 to 95, preferably 40 to 90 and particularly preferably 40 to 85% by weight of a rubber-elastic basic stage, based on al)

all) 50 to 100, preferably 60 to 100 and particularly preferably 70 to 100% by weight of a (C 1 -C ₁₀ -alkyl) ester of acrylic acid,

αl2) 0 to 10, preferably 0 to 5 and particularly preferably 0 to 2% by weight of a polyfunctional, crosslinking monomer,

αl3) 0 to 40, preferably 0 to 30 and particularly preferably 0 to 20% by weight of one or more further monoethylenically unsaturated monomers,

or off

all *) 50 to 100, preferably 60 to 100 and particularly preferably 65 to 100% by weight of a diene with conjugated double bonds,

al2 *) 0 to 50, preferably 0 to 40 and particularly preferably 0 to 35% by weight of one or more monoethylenically unsaturated monomers,

or off

all **) 50 to 100, preferably 60 to 100 and particularly preferably 65 to 100% by weight of a mixture of ethylene, propylene and a diene,

αl2 **) 0 to 50, preferably 0 to 40 and particularly preferably 0 to 35% by weight of one or more further onoethylenically unsaturated monomers, and

α2) 5 to 70, preferably 10 to 60 and particularly preferably 15 to 60% by weight of a graft stage, based on α2), α21) 50 to 100, preferably 60 to 100 and particularly preferably 65 to 100% by weight of a styrene compound of the general formula I.

α22) 0 to 40, preferably 0 to 38 and particularly preferably 0 to 35% by weight of acrylonitrile or methacrylonitrile or mixtures thereof,

α23) 0 to 40, preferably 0 to 30 and particularly preferably 0 to 20% by weight of one or more further monoethylenically unsaturated monomers.

As (-CC-alkyl) esters of acrylic acid, component all), especially ethyl acrylate, 2-ethylhexyl acrylate and n-butyl acrylate are suitable. 2-ethylhexyl acrylate and n-butyl acrylate are preferred, n-butyl acrylate is very particularly preferred. Mixtures of various alkyl acrylates which differ in their alkyl radicals can also be used.

Crosslinking monomers αl2) are bifunctional or polyfunctional comonomers with at least two olefinic double bonds, for example butadiene and isoprene, divinyl esters of dicarboxylic acids such as succinic acid and adipic acid, diallyl and divinyl ethers of bifunctional alcohols such as ethylene glycol and de-butane-1,4-diol, diesters acrylic acid and methacrylic acid with the bifunctional alcohols mentioned, 1,4-divinylbenzene and triallyl cyanurate. Particularly preferred are the acrylic acid ester of tricyclodecenyl alcohol, known under the name dihydrodicyclopentadienyl acrylate, and the allyl esters of acrylic acid and methacrylic acid.

Crosslinking monomers αl2) may or may not be present in the molding compositions, depending on the type of molding compositions to be produced, in particular on the desired properties of the molding compositions.

If crosslinking monomers αl2) are contained in the molding materials, the amounts are 0.01 to 10, preferably 0.3 to 8 and particularly preferably 1 to 5% by weight, based on αl).

The other monoethylenically unsaturated monomers α1l3) which may be present in the graft core al) at the expense of the monomers all) and al2) are, for example:

vinylaromatic monomers such as styrene, styrene derivatives of the general formula I; Acrylonitrile, methacrylonitrile;

Ci to C alkyl esters of methacrylic acid, such as methyl methacrylate, and also the glycidyl esters, glycidyl acrylate and methacrylate;

N-substituted maleimides such as N-methyl, N-phenyl and N-cyclohexyl maleimide;

Nitrogen-functional monomers such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate, vinylimidazole, vinylpyrrolidone, vinylcaprolactam, vinylcarbazole, vinylaniline, acrylamide and methacrylic acid;

aromatic and araliphatic esters of acrylic acid and methacrylic acid, such as phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 2-phenoxyethyl acrylate and 2-phenoxyethyl methacrylate;

unsaturated ethers such as vinyl methyl ether,

as well as mixtures of these monomers.

Preferred monomers αl3) are styrene, acrylonitrile, methyl methacrylate, glycidyl acrylate and methacrylate, acrylamide and methacrylamide.

Instead of the basic stage monomers all) to al3), the basic stage αl) can also be composed of the monomers all *) and al2 *).

Suitable dienes with conjugated double bonds, all *) are butadiene, isoprene, norbornene and their halogen-substituted derivatives, such as chloroprene. Butadiene and isoprene, in particular butadiene, are preferred.

The monomers which have already been mentioned for the monomers αl3) can also be used as further monoethylenically unsaturated monomers αl2 *).

Preferred monomers αl2 *) are styrene, acrylonitrile, methyl methacrylate, glycidyl acrylate and methacrylate, acrylamide and methacrylamide. The graft core αl) can also be composed of a mixture of the monomers all) to al3) and all *) to al2 *).

Instead of the basic stage monomers all) to al3) or all *) and al2 *), the basic stage αl) can also be constructed from the monomers all **) and al2 **). Suitable diene in the monomer mixture all **), which is used in a mixture with ethylene and propylene, are in particular ethylidene norbornene and dicyclopentadiene.

The monomers mentioned for αl3) can also be used as further monoethylenically unsaturated monomers αl2 **).

The graft core can also be made from a mixture of the monomers all) to al3) and all **) to al2 **), or from a mixture of the monomers all *) to al2 *) and all **) to al2 **) , or from a

Mixture of the monomers all) to al3), all *) to al2 *) and all **) to al2 **).

With regard to the monomers α21) and α23), reference is made to the comments on components al) and a3) below. Accordingly, the graft shell α2) can contain further monomers α22) or α23) or mixtures thereof at the expense of the monomers α21). The graft shell α2) is preferably constructed from polymers as mentioned above as preferred embodiments A / I to A / 3.

Graft polymers with several "soft" and "hard" stages, e.g. of the structure αl) -α2) -αl) -α2) or α2) -αl) -α2).

The copolymers can be prepared in various ways, in particular in emulsion, in microemulsion, in mini-emulsion, in suspension, in microsuspension, in mini-suspension, as precipitation polymerization, in bulk or in solution, continuously or batchwise. The corresponding procedural measures are known to the person skilled in the art.

If the graft core contains the monomers all) to al3), then after mixing with a copolymer of styrene and acrylonitrile (SAN), so-called ASA form asεen (acrylonitrile-styrene-acrylic esters) are formed. If the graft core contains the monomers all *) to al2 *), after mixing with a copolymer of styrene and acrylonitrile (SAN), molding materials of the ABS type (acrylonitrile-butadiene-styrene) are formed. If the graft core contains the monomers all **) to al2 **), after mixing with a copolymer of styrene and acrylonitrile (SAN), molding compositions of the AES type (acrylonitrile EPDM styrene) are formed. In a preferred embodiment, it acts Accordingly, the microgranules are ASA graft polymers or ABS graft polymers or AES graft polymers, or types of ASA, ABS and AES graft polymers.

The form dimensions may contain additives in addition to the copolymers. Additives that are liquid or wax-like at room temperature are suitable as additives. In addition, additives which are finely divided, for example having a grain size of up to about 50 μm, preferably up to about 10 μm, are suitable. Such additives are e.g. Colorants, chalk or talc and are generally incorporated into the microgranules. It is preferred that the molding compositions contain no large-volume or fibrous fillers. In general, the additives are only used in small quantities. Their share in the total weight of the molding compound from which the microgranules are made is generally not more than 20% by weight, based on the molding compound. The molding compositions preferably contain from 0 to 20% by weight, preferably from 0 to 10% by weight, based on the molding composition, of additives.

Suitable additives are customary additives, such as lubricants or mold release agents, colorants, flame retardants, antioxidants, light stabilizers or antistatic agents, and also other additives or mixtures thereof.

Suitable lubricants and mold release agents are e.g. Fatty acids such as stearic acids, stearyl alcohol, fatty acid esters with 6-20 C atoms, e.g. Stearic acid esters, metal salts of fatty acids, e.g. Mg, Ca, Al, Zn stearate, fatty acid amides such as stearic acid amides, and silicone oils, montan waxes and those based on polyethylene and polypropylene, furthermore hydrocarbon oils, paraffins and carboxylic acid esters from long-chain carboxylic acids and ethanol, fatty alcohols, glycerol, Ethanediol, pentaerythritol or other alcohols. The proportion of lubricants and mold release agents, based on the molding composition, is generally not more than 5% by weight, preferably from 0.02 to 3% by weight.

Colorants are especially pigments and dyes. Pigments are, for example, titanium dioxide, phthalocyanines, ultramarine blue, iron oxides or carbon black, and the class of organic pigments. Dyes are to be understood as all dyes which are suitable for transparent, semi-transparent or non-transparent coloring of polymers. Dyes of this type are known to the person skilled in the art. The average particle size of the colorants is generally in the range from 0.01 to 20 μm, preferably 0.01 to 10 μm. The mean particle size specifies the sizes determined from the integral mass distribution. The mean particle sizes 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.-Polymers 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 deduced what percentage by weight of the particles have a diameter equal to or less than a certain size. The average particle diameter, which is also referred to as the dso 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 dso value. Likewise, 50% by weight of the particles then have a larger diameter than the dso value.

The molding compositions usually contain no more than 10% by weight, preferably no more than 8% by weight, of colorant. Particular preferred dimensions contain no colorants.

As flame retardants e.g. the halogen-containing or phosphorus-containing compounds known to the person skilled in the art, magnesium hydroxide and other customary compounds, or mixtures thereof, are used. Their proportion in the molding compositions is generally up to 65% by weight, e.g. from 20 to 40% by weight, based on the molding composition. According to a particularly preferred embodiment, the molding compositions contain no flame retardants.

Suitable antioxidants (heat stabilizers) are, for example, sterically hindered phenols, including reaction products of p-cresols and dicyclopentadiene, hydroquinones, various substituted representatives of this group and mixtures thereof. They are commercially available as Topanol Wingstay or Irganox. The molding compositions generally contain up to 1% by weight, based on the molding composition of these additives, in particular from 0.05 to 0.5% by weight.

Suitable stabilizers against the action of light are, for example, various substituted resorcinols, salicylates, benzotriazoles, cinnamic acid compounds, organic phosphites and phosphonites, benzophenones, HALS (hindered amine light stabilizers), as are commercially available, for example, as Tinuvin ^® or Uvinul ^® .

Esters and / or amides of b- (3,5-di-t-butyl-4-hydroxyphenyl-propionic acid and / or benzotriazoles) can also be used as stabilizers. Possible antioxidants are examples mentioned in EP-A 698637 and EP-A 669367. In particular, 2, 6-di-t-butyl-4-methylphenol, pentarythrityl-tetrakiε- [3— (3, 5-di-t-butyl-4-hydroxyphenyl) propionate and N, N can be used as phenolic antioxidants Use '-Di— (3, 5-di-t-butyl-4-hydroxyphenyl-propionyl) hexamethylene diamine. The proportion of stabilizers in the molding compositions is generally from 0.1 to 1% by weight, based on the molding compositions.

Suitable antistatic agents, the proportion of which in the molding compositions is generally up to 3% by weight, based on the molding compositions, are, for example, amine derivatives such as N, N-bis (hydroxyalkyl) alkylamines or alkylene amines, polyethylene glycol esters and glycerol mono- and dietearates, ethylene oxide-propylene oxide copolymers or block polymers and their mixtures.

The additives can be used individually or in a mixture. For example, Mixtures of heat stabilizers, light stabilizers, antistatic agents and lubricants are present in the microgranules in a proportion of 0.8 to 5.3% by weight. Among these, preference is given to mixtures in which the proportion of antistatic agents is 28 to 63% by weight.

The microgranules can be produced by methods known per se. For example, the molding compositions can be obtained by incorporating one or a mixture of different additives into one or a mixture of different copolymers. However, the additives can also be added, for example, during the preparation of the copolymers. Some of the additives can also be added during the production of the copolymers, and some of the additives can be incorporated later. The incorporation of the additives and / or the production of the mixture of different copolymers can be carried out, for example, above their softening temperature, for example at temperatures in the range from 180 to 320 ° C., in customary mixing devices such as extruders or kneaders. The plasticized molding compound can then be pressed through a nozzle or perforated plate. The nozzle or bores in the perforated plate have a diameter which corresponds to or is smaller than the later diameter of the microgranules. As a rule, the nozzle or the bores have a diameter which is smaller than the diameter of the pearly microgranules. For example, the ratio of nozzle or bore diameter to diameter of the microgranules can be from 0.5: 1 to 0.8: 1. For example, this can be in the range from 0.2 to 2.5 mm. The application can be granulated under water. The temperatures of the polymer melt can range from 220 to 320 ° C. It is also possible, if not preferred, one, several or to discharge a large number of strands, to cool them in water and then to cut them into microgranules.

The microgranules generally have very small residues of vaporizable monomers which originate from the production of the molding composition.

In addition, the microgranules generally contain only a low residual moisture. As a rule, the proportion of re-water is not more than 0.3% by weight, preferably not more than 0.2% by weight, in particular not more than 0.1% by weight, in each case based on the total weight. The residual water content is determined by means of a thermal balance (Satorius MA 30) on the basis of samples with a weight in the range of approx. 1 to 5 g by determining the initial weight of the samples, the samples at 160 ° C. for a period of 20 Dried minutes and the weight loss is determined.

As a rule, the microgranules have a Shore hardness A of more than 90 ° and a Shore hardness D of more than 60 °. The Shore hardness is determined in accordance with DIN 43505 with test device A or test device D.

Component B)

According to the invention, thermoplastic powder or thermoplastic granules or a mixture of powdered and granular thermoplastic is used as component B). In principle, powders or granules of any shape and size can be used.

For example, the thermoplastic powders can consist essentially of spherical, acicular or platelet-shaped particles. The powders can be of one molding compound and a mixture of two or more, e.g. represent three or four different shapes. The powders can also be of different molding compositions and have the same shape or additionally differ in their shape. According to a preferred embodiment, the powders can have the shape of spherical irregular particles and are of a shape.

The thermoplastic granules can be round, ellipsoidal, cube-shaped or cylindrical, for example. It is also possible to use mixtures in which the thermoplastic granules are of different shapes and differ in shape from one another. The thermoplastic granules are particularly preferred from a molding compound and are round to ellipsoid. The thermoplastic granules can be standard granules or microgranules.

The thermoplastic powders or thermoplastic granules that can be used as component B generally have grain sizes of 50 μm to 5 mm. However, their grain sizes can also be below or above. The thermoplastic powders preferred as component B generally have grain sizes from 50 to 300 μm, in particular from 80 to 250 μm, for example from 100 to 200 μm. Agglomerates of these particles, which have diameters in the millimeter range, for example up to 2 mm in size, are also possible. It is also possible for the powders to have a broader or narrower distribution of the particle sizes. Their bulk density is preferably in the range from 0.4 to 0.7 g / 1, preferably in the range from 0.45 to 0.68 g / 1, for example from 0.55 to 0.65 g / 1. The bulk density and the grain size are determined as described above.

According to the invention, component B) is a thermoplastic which is a molding composition which differs from that of which the microgranular component A) is made.

One of the preferred embodiments includes components B) which contain thermoplastic powders or thermoplastic granules which are based on molding compounds as mentioned under component A, provided the molding compounds on which the microgranules A and component B are based differ from one another. Polycarbonates, polyesters, such as polyethylene terephthalate or polybutylene terephthalate, polyamides, polyoxymethylene, polyolefins such as polypropylene or polyethylene are also suitable. Among them, polycarbonates, polyamides and polyesters are preferred.

The thermoplastic can particularly preferably be a molding composition which contains a polyvinyl chloride, (PVC) or a polyvinyl difluoride (PVDF).

As PVC, those with degrees of polymerization in the range from P _n 380 to 4700 are particularly suitable. Furthermore PVC with high or low syndiotacticity can be used. Emulsion, suspension or bulk PVC can be used as PVC, of which suspension PVC is preferred.

It is also possible for the thermoplastic to be a molding compound which is a mixture of two or more, for example three to ten, of the polymers mentioned. In addition, the thermoplastic can be a molding compound made from a copolymer of a vinyl aromatic table monomers, insofar as they differ from the one from which the microgranules A) are made. For example, component A) may be microgranules based on a graft copolymer, while component B) may be based on SAN in powder or granule form.

The thermoplastics can contain additives, the proportion of which can vary over a wide range. As a rule, the proportion of additives, based on the thermoplastic, is up to 150% by weight. It is preferably in the range from 1 to 80% by weight, in particular in the range from 2 to 50% by weight. Suitable additives are those mentioned above under component A). In addition, the thermoplastics can also comprise fillers and reinforcing materials as additives.

If PVC is used as the thermoplastic, the thermoplastics can also include additives that are typical of PVC. These include e.g. Stabilizers that counteract the degradation of PVC through dehydrohalogenation such as organotin, lead, cadmium or zinc compounds. Phenolic antioxidants or organotin mercaptides in conjunction with sterically hindered phenols or phosphites can, for example, also be used as stabilizers in order to suppress the autooxidation of PVC. Organotin sulfides or carboxylates can also be used. Examples of further additives are barium-containing compounds such as barium carboxylates, but in particular metal-free stabilizers such as β-aminocrotonic acid esters. Other stabilizers are known to the person skilled in the art. Additives that can be used in the thermoplastics that contain PVC include plasticizers from the group of phthalates, adipine, azelaic and sebacic acid esters, phosphates, alkyl sulfonic acid phenyl esters, acetyl tributyl citrate and tri -2-ethylhexyl trimelliate, tri-iso-octyl trimelliate, the epoxidized fatty acid esters and the polyesters. Such and further plasticizers are known to the person skilled in the art.

Examples of fibrous or pulverulent fillers are carbon or glass fibers in the form of glass fabrics, glass mats or glass silk roving, cut glass, glass balls and wollastonite, particularly preferably glass fibers. If glass fibers are used, they can be provided with a size and an adhesion promoter for better compatibility with the blend components. The glass fibers can be incorporated both in the form of short glass fibers and also in the form of continuous strands (rovings). The thermoplastics can be produced by mixing processes known per se, for example by melting in an extruder, Banbury mixer, kneader, roller mill or calender and subsequent comminution. If the thermoplastic is based on PVC, processing is preferably carried out using calenders or rollers.

In some cases, the additives can also be added during the course of the production of the thermoplastics. The additives can be used individually or as a mixture of two or more, for example three to ten, in the thermoplastics.

Thermoplastic powders either occur directly during the manufacture of the thermoplastics as such or can be broken down mechanically, e.g. be produced by grinding, for example cryomilling processes. The thermoplastic granules can be produced as described above under component A). Thus, the plasticized thermoplastic can be pressed under pressure through a nozzle or perforated plate adapted to the desired particle size of the thermoplastic granulate and then granulated under water or discharged as a strand, cooled and then comminuted.

Miεchungen

According to the invention, preference is given to mixtures in which the microgranules A have a bulk density which is not more than 30% greater or less than the bulk density of component B. Mixtures in which the microgranules A have a bulk density which is not more than 20% are particularly preferred, in particular not more than 15% greater or less than the bulk density of component B.

In the mixtures according to the invention, the proportions of components A) and B) can vary within wide limits. Preference is given to mixtures which, based on the mixture, from 2 to 30, particularly preferably from 3 to 25, in particular from 5 to 15% by weight of component A) and from 70 to 98% by weight, particularly preferably from 75 up to 97% by weight, in particular from 85 to 95% by weight of component B) and, if desired, additives.

Examples of suitable compositions of mixtures according to the invention are those which

from 15 to 25% by weight of a microgranulate based on one

ABS and from 75 to 85% by weight of a polycarbonate powder

contain

or such

from 15 to 30% by weight of a mixture of microgranules on the

Example of SAN and a polybutadiene rubber and a microgranulate based on α-methylstyrenearylnitrile copolymers and a polybutadiene rubber and

from 70 to 85% by weight of a polyamide powder based on polyamide 6.6

contain

or those who

from 5 to 20% by weight of microgranules based on one

ABS and

from 75 to 95% by weight of a PVC powder

contain

or those who

from 5 to 20% by weight of microgranules based on SAN, ABS or α-Me SAN,

from 40 to 92% by weight of a PVC powder

from 1 to 13% by weight of a colorant such as titanium dioxide, carbon black or iron oxide,

from 1 to 10% by weight of a stabilizer or stabilizer mixture

contain from 1 to 2% by weight of a lubricant and from 0 to 15% by weight of a filler such as chalk

The mixtures according to the invention are very stable against segregation. The mixtures according to the invention are also distinguished by the fact that their component A has a low proportion of fine dust, as a result of which they themselves have a reduced proportion of fine dust.

Particulate matter is understood to mean particles whose grain size is less than 500 μm. Preferred mixtures according to the invention have a fine dust fraction in component A which is below 5%, preferably below 1% and particularly preferably 0%. Eε is by means of

Dry sieve analysis determined in accordance with DIN 53447 as stated above.

The microgranules A furthermore make the thermoplastics B easier to process. In particular, the microgranules A cause an increase in the toughness, the elasticity and the heat resistance of the thermoplastics of component B. The mixtures according to the invention can be processed to give moldings, films or fibers. This can e.g. by generally known processes such as extrusion and subsequent injection molding, calendering or by rolling processes. For example, profiles or tubes can be produced directly from the mixture according to the invention by means of extrusion, it being possible to use them overall in the form which results from the mixing of components A) and B). With this production process it is therefore not absolutely necessary to melt the mixtures according to the invention first and to bring them into a granular form. This production process is particularly preferably used for mixtures according to the invention which contain a PVC as component B). The mixtures according to the invention, which comprise a PVC as component B), can also be processed particularly advantageously by calendering or in roller mills. Finished products such as foils, rolled skins or flat sheets can also be obtained directly. The mixtures according to the invention can be used, for example, in the production of floor coverings, decorative films, automobile interior linings or sealing sheets for construction or garden, such as sealing sheets which are used in roofs, basements but also dams or ponds.

Examples

Production of components AI to A4

The components AI to A4 mentioned by way of example were melted in a twin-screw extruder with a screw diameter of 26 mm and a length of 35 μm at speeds between 300 and 600 rpm and then pelletized. A gala underwater pelletizer with a perforated plate served as the pelletizer 20 x 0.8 mm. The throughputs and granulation conditions are given in the individual examples.

Component AI

A microgranulate consisting of 50% styrene-acrylonitrile copolymer (SAN) with a viscosity number (VZ) of 65 ml / g, measured on a 0.5% by weight solution in dimethylformamide at 23 ° C. and a content of 24% acrylonitrile (AN) and 50% of a graft rubber made of 60% polybutadiene and 40% SAN in a ratio of 70:30. The production was carried out by granulating by means of an extruder equipped with a perforated plate 20 x 0.8 mm at 450 rpm, extruder at 450 rpm and at throughputs of 14 kg / h. A pelletizing head with 5 knives was used at a speed of 5000 rpm. The cooling water temperature was 75-80 ° C.

Component A2

A mixture (blend) of 70% SAN with a styrene content of 76% and a VZ of 65 ml / g was measured on a 0.5% strength by weight solution in dimethylformamide at 23 ° C. and a graft copolymers (30%) made of 60% polybutadiene and 40% SAN in a ratio of 70:30. This was granulated by underwater pelletizing over a 20 x 0.8 mm perforated plate with a 5-part cutter head at 5000 rpm in a coolant temperature of 80-90 °. The throughput was 16-18 kg.

Component A3

A mixture (blend) of 56% by weight SAN with 33% by weight AN and a VZ of 60 ml / g measured on a 0.5% by weight solution in dimethylformamide at 23 ° C. and a graft rubber made from 60 % Polybutadiene and 40% SAN in the ratio 70:30 and 3% of an amide wax εeε was granulated at a coolant temperature of 75-85% with 14 kg / h. A pelletizing head with 5 knives was used, which worked at 5000 rpm.

Component A4

A copolymer of 70% α-methylstyrene and 30% AN and a VZ of 60 ml / g, measured on a 0.5 wt .-% solution in dimethylformamide at 23 ° C was at 24 kg / h at a cooling temperature of 75 ° C (5 Meεser / 5000 rpm) granulated under water. Comparative component AVI

The same polymer as Al was not microgranulated but processed under standard conditions to form standard granules with a grain size of approx. 3.5 mm.

Comparative component AV3

The same polymer as A3 was not microgranulated but processed under standard conditions to a standard granulate with a grain size of approx. 4 mm.

Comparative component AV4

The same polymer as A4 was not microgranulated, but ground with a cutting mill and an insert of about 2 mm.

Determination of the grain sizes and bulk densities of components AI to A4

The grain sizes were determined using dry sieve analysis in accordance with DIN 53477. The amount of screenings was 300 g each. The sieve set used was that given in the tables. Otherwise, the procedure was as specified in DIN 53477.

The bulk densities were measured by filling a measuring cylinder with the respective microgranules at room temperature up to one liter. The weight of this volume of microgranules was then determined.

Component AI

Result of the dry sieve analysis:

Particulate matter content: 0% residue (Rl) bulk density: 624 g / 1

Component A2

Result of the dry sieve analysis:

Particulate matter fraction 0% residue (Rl) bulk density: 640 g / 1

Component A3

Result of the dry sieve analysis:

Particulate matter: 0% residue (Rl) Bulk density: 626 g / 1 Component A4

Results of the dry sieve analysis:

Particulate matter content: 0% residue (Rl) Bulk density: not determined

Component AV4

Result of the dryer fabric analysis:

Particulate matter content> 2.5% residue (Rl) bulk density: 462 g / 1

Mixture Ml

100 parts by weight of PVC were mixed intensively in a mixer with 8 parts by weight of component AI and 4 parts by weight of titanium dioxide, 8 parts by weight of chalk and 4 parts by weight of stabilizers and then extruded into test profiles in a single-screw extruder , The mixture showed no signs of segregation. The test profiles were distinguished by a homogeneously pigmented surface.

Mixture M2 according to the invention

100 parts by weight of PVC were melted with 15 parts by weight of component A3 and 2 parts by weight of a stabilizer using a calender and mixed until the mixture was homogeneous. The mixture was then shaped into a film.

Comparison mix MV1

The attempt to prepare the mixture Ml was repeated, but the component AVI was used instead of component A1.

The test profiles have spots that were less pigmented than the rest of the surface.

Comparative mixture MV2

The attempt to prepare mixture M2 was repeated, but component AV3 was used instead of component A3.

The time until a homogeneous mixture was achieved was very much longer than for the preparation of the mixture according to the invention. The mixture melted unevenly. Inhomogeneous films were obtained.

Claims

Patentanεprüche

1. containing mixture,

A) at least one blowing agent-free microgranulate from a molding composition containing at least one homopolymer or copolymer of vinyl aromatic monomers or one (alkyl) acrylate and

B) at least one thermoplastic, which differs from the molding compound used in component A), in powder and / or granule form.

2. Mixture according to claim 1, wherein the microgranules from a molding compound containing a copolymer is a vinyl aromatic monomer.

3. Mixture according to claims 1 to 2, wherein the thermoplastic is from a molding composition containing at least one polyvinyl chloride, or a polyvinyl difluoride or mixtures thereof.

4. Mix according to claims 1 to 3, in which the microgranules have a bulk density which is not more than 30% greater or less than the bulk density of component B.

5. Mixture according to claims 1 to 4, wherein the microgranules have a proportion of less than 5% by weight, based on the microgranules, of particles whose grain size, determined by means of dry sieve analysis in accordance with DIN 53477, is not greater than 500 μm ,

6. propellant-free microgranules, a grain size, determined by means of dry sieve analysis according to DIN 53477 from 0.5 to 2.5 mm from a molding composition containing at least one (co) polymer of a vinylaromatic monomer.

7. Use of blowing agent-free microgranules from a molding composition containing at least one homo- or copolymer of a vinylaromatic monomer or an (alkyl) acrylate for the production of a mixture comprising at least one of these microgranules as component A) and at least one thermoplastic which differs from the used in component A), in powder or granular form as component B).

8. Use of the mixture according to claims 1 to 5 for the production of moldings, films or fibers.

9. molded articles, films or fibers, produced using the mixture according to claims 1 to 5.

10. A process for the production of moldings, foils or fibers according to claim 9, characterized in that in a first step a mixture according to claims 1 to 5 is produced, in a second step the mixture on one

Rolling mill or a calender processed and in a third step to form the shaped bodies, films or fibers.