HK1138609A - Molding compound for matt molded polyacrylate bodies - Google Patents

Description

Molding composition for matt polyacrylate moldings

Technical Field

The invention relates to a molding composition for matt moldings, to the corresponding moldings and to their use.

Background

Moulding compositions based on polymethyl methacrylate (PMMA) are used for a wide variety of applications. For this purpose, such compositions are usually extruded or injection-molded into moldings. These moldings exhibit the typical properties of PMMA, such as high scratch resistance, weathering resistance, heat resistance and excellent mechanical parameters, such as tensile modulus, and good stress cracking resistance.

The fields of application of extruded or coextruded PMMA mouldings are very diverse: for example, extruded or coextruded sheets are used not only in the exterior areas, especially for automotive accessories, construction elements, sports surfaces and lamp housings, but also in the interior areas, especially in the furniture industry, for lamp housings and interior equipment for automobiles.

In addition to extruded or coextruded PMMA mouldings with transparent, smooth surfaces, matt, preferably rough surfaces are often desired for these applications because of their more pleasant tactile and optical effects. Such surfaces are achieved primarily by using molding compositions in which organic or inorganic particles are incorporated.

However, the molding compositions modified in this way do not exhibit good mechanical properties, in particular satisfactory abrasion resistance, when an organic dulling agent is used. Furthermore, good weathering resistance of the corresponding moldings is often only ensured by the use of large amounts of light stabilizers.

A disadvantage in the processing of the customary inorganic matting agents, for example talc, is the complicated and expensive incorporation into PMMA molding compositions. For example, very high shear energies must be used during compounding to introduce such inorganic matting agents uniformly into the molding composition. If no homogeneous distribution of the scattering agent in the molding composition is ensured, this can be observed at the surface of the extruded or coextruded PMMA moldings produced therefrom (defects or irregularities, for example pimples). In addition, other material properties of such moldings are to be improved.

WO 02/068519 describes a composite material made of a matrix, for example PMMA, and ceramic beads dispersed therein, for example W-410A solid surface material of construction. The ceramic beads are provided with a functional coating that reacts with the resin of the substrate and covalently links the beads to the substrate. The surface material of WO 02/068519 is distinguished by a high flame resistance.

WO 03/054099 relates to an adhesive tape, the uppermost layer of which comprises a transparent resin and a matting agent, for example ceramic beads.

WO 97/21536 discloses an extrusion process which can be used to incorporate matting agents, such as ceramic beads, into thermoplastic polymers.

US 5,787,655 describes slip resistant membranes composed of thermoplastic polymers into which inorganic beads, such as ceramic beads, have been introduced.

US 5,562,981 relates to the construction of truck trailers. The side walls of the trailer comprise a fiber reinforced plastic into which ceramic beads are mixed to additionally reinforce the walls.

WO 2005/105377 discloses a composition consisting of a thermoplastic, which has a processing temperature of at least 280 ℃, super abrasive particles and fillers, such as ceramic beads. The composition is used for preparing abrasive tools.

Disclosure of Invention

Objects and solutions

Thus, it was an object of the present invention to find molding compositions which can be used to prepare moldings having a fine matt surface. The molding compositions should be able to be produced and processed in the simplest possible manner, in particular at low energy expenditure. Furthermore, the articles which can be produced from the molding compositions should have as good as possible optical and mechanical properties, as high a long-term stability and weathering resistance as possible, and as uniform as possible a velvet-like matt surface with as low a gloss as possible. Furthermore, the articles which can be produced from the molding compositions should also have as rough a surface as possible.

These objects, and also other objects which may be inferred or directly derived from the above discussion, are achieved by a molding composition having all the features of claim 1 of the present invention. The dependent claims dependent on the claims describe particularly suitable embodiments of the molding composition, and the further claims relate to particularly advantageous uses of the molding composition.

Moulding compositions which are outstandingly suitable for the production of mouldings having a fine matt surface are successfully obtained in a manner which cannot be readily foreseen by providing a composition comprising, in each case based on the total weight of the composition:

A) from 49.5% by weight to 99.5% by weight of a polymer matrix consisting of (meth) acrylate (co) polymers or of a mixture of (meth) acrylate (co) polymers,

B)0.5 wt% to 15.0 wt% ceramic beads,

wherein the molding composition has a volume melt index MVR, measured according to ISO 1133 at 230 ℃ and 3.8kg, of 0.1cm³/10min-5.0cm³And/10 min. The molding compositions described herein can be produced and processed in a comparably simple manner, in particular at low energy expenditure, and furthermore make it possible to achieve critical component geometries.

At the same time, articles which can be prepared from the molding compositions exhibit a combination of advantageous properties:

they have very good optical properties, in particular a relatively uniform velvet-like matt surface with very low gloss. This effect is further enhanced by the attractive surface roughness of the molded article.

They exhibit excellent mechanical properties, in particular very good abrasion resistance, impact and notched impact resistance, a high modulus of elasticity and high tensile strength, high scratch hardness and high Vicat softening temperature, and a low coefficient of thermal expansion.

The long-term stability and weathering resistance of the moldings described are likewise excellent.

Detailed Description

Polymer matrix A)

The polymer matrix A) consists of a (meth) acrylate (co) polymer or a mixture of (meth) acrylate (co) polymers.

(meth) acrylate (co) polymer

Within the scope of the first particularly preferred embodiment of the present invention, the (meth) acrylate (co) polymer of the matrix comprises a homopolymer or copolymer of at least 80.0% by weight of methyl methacrylate and optionally up to 20.0% by weight of other monomers copolymerizable with methyl methacrylate. The (meth) acrylate (co) polymers advantageously consist of 80.0 to 100.0% by weight, preferably 90.0 to 99.5% by weight, of free-radically polymerized methyl methacrylate units and optionally 0.0 to 20.0% by weight, preferably 0.5 to 10.0% by weight, of other comonomers capable of free-radical polymerization, such as (meth) acrylic acid-C1-C4-Alkyl esters, in particular methyl acrylate, ethyl acrylate or butyl acrylate. Average molecular weight M of the matrix_wPreference is given to 90000g/mol to 200000g/mol, in particular 95000g/mol to 180000 g/mol.

The polymer matrix is preferably composed of (meth) acrylate (co) polymers having a composition of 96.0 to 100.0% by weight, preferably 97.0 to 100.0% by weight, particularly preferably 98.0 to 100.0% by weight, of methyl methacrylate and 0.0 to 4.0% by weight, preferably 0.0 to 3.0% by weight, particularly 0.0 to 2.0% by weight, of methyl acrylate, ethyl acrylate and/or butyl acrylate.

The solution viscosity of the (meth) acrylate (co) polymer in chloroform at 25 ℃ (ISO 1628-part 6) is preferably 45.0ml/g to 80.0ml/g, preferably 50.0ml/g to 75.0 ml/g. This may correspond to a molecular weight M of 80000-200000(g/mol), preferably 100000-170000_w(weight average). Molecular weight M_wCan be determined, for example, by gel permeation chromatography or by light scattering methods (see, for example, Encyclopedia of Polymer Science and Engineering, second edition, Vol.10, p.1 and subsequent pages, J.Wiley, 1989, H.F. Mark et al).

The Vicat softening temperature VET (ISO 306-B50) is preferably at least 100 ℃, particularly preferably at least 104 ℃, more preferably from 104 ℃ to 114 ℃, in particular from 105 ℃ to 110 ℃.

The polymer has a volume melt index MVR (ISO 1133, 230 ℃/3.8kg) of advantageously 0.5cm³/10min-5.0cm³Per 10min, particularly preferably 1.0cm³/10min-2.9cm³/10min。

(meth) acrylate (co) polymers containing maleic anhydride

Within the scope of the second particularly preferred embodiment of the invention, the (meth) acrylate (co) polymer of the matrix comprises a copolymer composed of methyl methacrylate, styrene and maleic anhydride.

Solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6Min) is preferably greater than or equal to 65ml/g, preferably from 68ml/g to 75 ml/g. This may correspond to a molecular weight M of 130000g/mol_w(weight average) (M)_wDetermined using gel permeation chromatography relative to polymethyl methacrylate as a calibration standard). Molecular weight M_wCan be determined, for example, by gel permeation chromatography or by light scattering methods (see, for example, Encyclopedia of Polymer Science and Engineering, second edition, Vol.10, p.1 and subsequent pages, J.Wiley, 1989, H.F. Mark et al).

The Vicat softening temperature VET (ISO 306-B50) is advantageously at least 112 ℃, particularly preferably from 114 ℃ to 124 ℃, in particular from 118 ℃ to 122 ℃.

The polymer has a volume melt index MVR (ISO 1133, 230 ℃/3.8kg) of advantageously 0.5cm³/10min-5.0cm³Per 10min, particularly preferably 1.0cm³/10min-2.9cm³/10min。

Particularly suitable quantitative ratios are:

50 to 90% by weight, preferably 70 to 80% by weight, of methyl methacrylate, 10 to 20% by weight, preferably 12 to 18% by weight, of styrene, and 5 to 15% by weight, preferably 8 to 12% by weight, of maleic anhydride.

In addition, the use of polymer mixtures has also proved to be very particularly suitable. They preferably comprise

d) At least one low molecular weight (meth) acrylate (co) polymer, characterized in that the solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) is less than or equal to 55ml/g, preferably less than or equal to 50ml/g, in particular 45ml/g to 55ml/g (this may correspond to a molecular weight M of 95000 g/mol)_w(weight average) (M)_wDetermined using gel permeation chromatography relative to polymethylmethacrylate as a calibration standard)),

which is mixed with

e) Higher molecular weight (meth) acrylate (co) polymers characterized by a solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) greater than or equal to 65ml/g, preferably 68ml/g to 75ml/g and/or

f) A further (meth) acrylate (co) polymer different from d), characterized in that the solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) is from 50ml/g to 55ml/g, preferably from 52ml/g to 54ml/g (this may correspond to a molecular weight M of 80000-_w(weight average)),

wherein the components d), e) and/or f) can each be referred to by themselves as a single polymer or as a mixture of polymers, the sum of d), e) and/or f) preferably being 100.0% by weight, and wherein the polymer mixture of d), e) and/or f) can also contain conventional additives, auxiliaries and/or fillers.

The following ratios are particularly preferred:

component d): preferably from 25.0 to 75.0% by weight, preferably from 40.0 to 60.0% by weight, in particular from 45.0 to 55.0% by weight.

Component e) and/or f): 10.0 to 50.0 wt.%, preferably 12.0 to 40.0 wt.%.

Components d) and e) are each advantageously copolymers of methyl methacrylate, styrene and maleic anhydride.

Particularly suitable quantitative ratios are:

50 to 90% by weight, preferably 70 to 80% by weight, of methyl methacrylate,

10 to 20% by weight, preferably 12 to 18% by weight, of styrene and

5-15% by weight, preferably 8-12% by weight, of maleic anhydride.

Component f) is preferably a homopolymer or copolymer of at least 80% by weight of methyl methacrylate and optionally up to 20% by weight of other monomers copolymerizable with methyl methacrylate.

Component f) is advantageously composed of 80.0 to 100.0% by weight, preferably 90.0 to 99.5% by weight% of free-radically polymerized methyl methacrylate units and optionally from 0.0 to 20.0% by weight, preferably from 0.5 to 10% by weight, of other comonomers capable of free-radical polymerization, such as C1-C4-alkyl (meth) acrylates, in particular methyl acrylate, ethyl acrylate or butyl acrylate. Average molecular weight M of the matrix_wPreference is given to 90000g/mol to 200000g/mol, in particular 100000g/mol to 150000 g/mol.

Component f) is preferably a copolymer of from 95.0 to 99.5% by weight of methyl methacrylate and from 0.5 to 5.0% by weight, preferably from 1.0 to 4.0% by weight, of methyl acrylate.

The Vicat softening temperature VET (ISO 306-B50) of component f) is advantageously at least 107 ℃ and particularly preferably from 108 ℃ to 114 ℃. The volume melt index MVR (ISO 1133, 230 ℃/3.8kg) is preferably greater than or equal to 2.5cm³/10min。

The copolymers described above can be obtained by free-radical polymerization in a manner known per se. EP-A264590, for example, describes a process for the preparation of moulding compositions consisting of a monomer mixture of methyl methacrylate, a vinylaromatic compound, maleic anhydride and, optionally, a lower alkyl acrylate, in which process: carrying out the polymerization up to a conversion of 50% in the presence or absence of a non-polymerizable organic solvent, and continuing the polymerization reaction from a conversion of at least 50% up to a conversion of at least 80% in the presence of an organic solvent at a temperature in the range of from 75 ℃ to 150 ℃, followed by evaporation of the low molecular weight volatile constituents.

JP-A60-147417 describes a process for the preparation of highly heat-resistant polymethacrylate moulding compositions, in which a monomer mixture consisting of methyl methacrylate, maleic anhydride and at least one vinylaromatic compound is fed at a temperature of 100-180 ℃ into a polymerization reactor suitable for solution polymerization or bulk polymerization and polymerized. DE-OS 4440219 describes a further preparation process.

For example, component a) can be prepared as follows: a monomer mixture of 3000g of methyl methacrylate, 600g of styrene and 400g of maleic anhydride was admixed with 1.68g of dilauroyl peroxide and 0.4g of tert-butyl perisononanoate (as polymerization initiator), 6.7g of 2-mercaptoethanol (as molecular weight regulator) and 4g of 2- (2-hydroxy-5-methylphenyl) benzotriazole (as UV absorber) and 4g of palmitic acid (as mold release aid).

The resulting mixture was charged to a polymerization cell and devolatilized for 10 minutes. The mixture was then polymerized in a water bath at 60 ℃ for 6 hours and at a water bath temperature of 50 ℃ for 25 hours. After about 25 hours, the polymerization mixture reached 144 ℃, i.e. its maximum temperature. After removal of the polymerization cell, the polymer was further heat-conditioned in an air oven at 120 ℃ for 12 hours.

The resulting copolymer was transparent and had a yellowness index to DIN 6167(D65/10 ℃ C.) of 1.4 and a TD65 light transmission to DIN5033/5036 of 90.9% for a pressed sheet of 8mm thickness. The Vicat softening temperature VET of the copolymer according to ISO 306-B50 is 121 ℃ and the reduced viscosity nsp/c is 65ml/g, which corresponds to an average molecular weight M of approximately 130000 Dalton (based on polymethyl methacrylate standards)_w。

For example, component d) can be prepared as follows: a monomer mixture consisting of, for example, 6355g of methyl methacrylate, 1271g of styrene and 847g of maleic anhydride is admixed with 1.9g of tert-butyl perneodecanoate and 0.85g of tert-butyl per-3, 5, 5-trimethylhexanoate (as polymerization initiator) and 19.6g of 2-mercaptoethanol (as molecular weight regulator) and 4.3g of palmitic acid. The resulting mixture may be charged to a polymerization cell and devolatilized, for example, for 10 minutes. The polymerization can then be carried out in a water bath, for example at 60 ℃ for 6 hours, and then at a water bath temperature of 55 ℃ for 30 hours. After about 30 hours, the polymerization mixture reached about 126 ℃, i.e., its maximum temperature. After the polymerization cell has been removed from the water bath, the polymer is further heat-conditioned, corresponding to component a) in the polymerization cell, for example at 117 ℃ for about 7 hours in an air oven.

Matting agent B): ceramic bead

The molding compositions of the invention also comprise from 0.5 to 15.0% by weight of ceramic beads. Ceramics are articles that consist essentially of inorganic, fine-grained raw materials and are shaped with the addition of water at room temperature and then dried, which sinter at greater than 900 ℃ during subsequent firing to produce hard, durable articles. The term also includes metal oxide based materials. Such ceramics that can be used according to the invention also include fiber-reinforced ceramic materials, such as silicon carbide ceramics, which can be prepared, for example, from silicon-containing organic polymers (polycarbosilanes) as starting materials.

The ceramic beads advantageously have no covalent bonds to the polymer matrix and can in principle be separated from the polymer matrix by physical separation methods, for example extraction methods using suitable solvents, such as Tetrahydrofuran (THF).

The ceramic beads also preferably have a spherical shape, where it is naturally possible for low deviations from a perfect sphere to occur.

The diameter of the ceramic beads is advantageously between 1 and 200. mu.m. Median diameter of ceramic beads (median D)₅₀) Preferably 1.0 μm to 15.0. mu.m. D₉₅The value is preferably less than or equal to 35 μm, particularly preferably less than or equal to 13 μm. The maximum diameter of such beads is preferably less than or equal to 40 μm, particularly preferably less than or equal to 13 μm. The particle size of these beads is preferably determined via sieve analysis.

The density of the ceramic beads is advantageously 2.1g/cm³-2.5g/cm³。

The particular composition of the ceramic beads is of minor importance to the present invention. Preferred beads comprise, based in each case on their total weight,

55.0-62.0 wt% SiO₂Particularly, amorphous SiO is preferable₂，

21.0-35.0 wt.% Al₂O₃，

Up to 7.0 wt.% Fe₂O₃，

Up to 11.0 wt.% Na₂O, and

up to 6.0 wt.% K₂O。

The surface area of the ceramic beads measured by the BET nitrogen adsorption method is preferably 0.8m²/g-2.5m²/g。

Also proven particularly suitable for the purposes of the present invention are those ceramic beads which are hollow on the inside. The ceramic beads preferably have a compressive strength such that more than 90% of the beads cannot be destroyed by a pressure of 410 MPa.

Ceramic beads which are very particularly suitable within the scope of the invention are, in particular, those from the company 3MDeutschland GmbHIn particular the models W-210, W-410, G-200 and G-400.

Impact modifier C)

The inventive molding compositions preferably comprise impact modifiers, particularly preferably impact modifiers based on crosslinked poly (meth) acrylates. The impact modifier is preferably not covalently bonded to the polymer matrix A). Component C) preferably has a two-or three-shell structure.

Particularly preferred impact modifiers are polymer particles which have a two-layer, particularly preferably three-layer core-shell structure and are obtainable by emulsion polymerization (see, for example, EP-A0113924, EP-A0522351, EP-A0465049 and EP-A0683028). Typical particle sizes of these emulsion polymers are from 100nm to 500nm, preferably from 200nm to 450 nm.

A three-layer or three-phase structure having one core and two shells may particularly be in the form as follows. The innermost (hard) shell may, for example, consist essentially of methyl methacrylate, a small proportion of a comonomer, such as ethyl acrylate, and a proportion of a crosslinker, such as allyl methacrylate. The intermediate (soft) shell can, for example, consist of butyl acrylate and optionally styrene, and also a proportion of a crosslinker, for example allyl methacrylate, while the outermost (hard) shell corresponds substantially mostly to the matrix polymer, with the result that compatibility and good bonding with the matrix are brought about (antinidung). The proportion of polybutyl acrylate in the impact modifier is decisive for the impact resistance and is preferably from 20.0 to 40.0% by weight, particularly preferably from 25.0 to 40.0% by weight.

Other impact-modified polymethacrylate molding compositions which are particularly suitable for the purposes of the present invention are described, for example, in EP-A0113924, EP-A0522351, EP-A0465049, EP-A0683028 and U.S. Pat. No. 3, 3,793,402. Commercially available products which are very particularly suitable are, for example, those from Mitsubishi RayonIR 441。

The molding compositions advantageously comprise from 5.0 to 50.0% by weight, preferably from 10.0 to 20.0% by weight, particularly preferably from 10.0 to 15.0% by weight, of an impact modifier, which is an elastomeric phase composed of crosslinked polymer particles. The impact modifiers are obtained in a manner known per se via bead polymerization or via emulsion polymerization.

Within the scope of another particularly preferred embodiment of the present invention, the impact modifiers are crosslinked particles which are obtainable by bead polymerization and have an average particle size of from 50 μm to 500 μm, preferably from 80 μm to 120 μm. They generally consist of: at least 40.0% by weight, preferably from 50.0 to 70.0% by weight, of methyl methacrylate, from 20.0 to 40.0% by weight, preferably from 25.0 to 35.0% by weight, of butyl acrylate, and from 0.1 to 2.0% by weight, preferably from 0.5 to 1.0% by weight, of crosslinking monomers, for example polyfunctional (meth) acrylates, for example allyl methacrylate, and optionally further monomers, for example from 0.0 to 10.0% by weight, preferably from 0.5 to 8.0% by weight, of C (meth) acrylate₁-C₄Alkyl esters, e.g. ethyl or butyl acrylate, preferably methyl acrylate, or other monomers polymerizable by vinyl means, e.g.Such as styrene.

Conventional additives, auxiliaries and/or fillers

The moulding compositions according to the invention may also comprise conventional additives, auxiliaries and/or fillers, for example heat stabilizers, UV absorbers, antioxidants, in particular soluble or insoluble dyes or colorants.

UV stabilizers and radical scavengers

The UV stabilizers which are optionally present are, for example, derivatives of benzophenone, the substituents, such as hydroxyl and/or alkoxy, being mostly in the 2-and/or 4-position. Including 2-hydroxy-4-n-octoxy benzophenone, 2, 4-dihydroxy benzophenone, 2, 2 ' -dihydroxy-4-methoxy benzophenone, 2, 2 ', 4, 4 ' -tetrahydroxy benzophenone, 2, 2 ' -dihydroxy-4, 4 ' -dimethoxy benzophenone, 2-hydroxy-4-methoxy benzophenone. Substituted benzotriazoles are also very suitable as UV stabilizing additives, including in particular 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [ 2-hydroxy-3, 5-bis (. alpha.,. alpha. -dimethylbenzyl) phenyl ] benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-3-5-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3, 5-di-tert-amylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole, 2- (2-, 2- (2-hydroxy-3-sec-butyl-5-tert-butylphenyl) benzotriazole and 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole.

Other UV stabilizers which may be used are ethyl 2-cyano-3, 3-diphenylacrylate, 2-ethoxy-2 '-ethyl-oxalanilide, 2-ethoxy-5-tert-butyl-2' -ethyl-oxalanilide and substituted phenyl benzoates.

The UV stabilizer may be present as a low molecular weight compound in the polymethacrylate composition to be stabilized, as described above. However, the UV-absorbing groups may also be covalently bonded within the matrix polymer molecule after copolymerization with polymerizable UV-absorbing compounds, such as acrylic, methacrylic or allyl derivatives of benzophenone derivatives or benzotriazole derivatives.

The proportion of UV stabilizers, which may also be a mixture of chemically different UV stabilizers, is generally from 0.01 to 1.0% by weight, in particular from 0.01 to 0.5% by weight, in particular from 0.02 to 0.2% by weight, based on the sum of all components of the polymethacrylate resin according to the invention.

As examples of free radical scavengers/UV stabilizers, there may be mentioned sterically hindered amines known under the name HALS (HALS)Hindered Amine Light Stabilizer (hindered amine light stabilizer)). They can be used for inhibiting the ageing process in coatings and plastics, in particular in polyolefin plastics (Kunststoffe (plastics), 74(1984)10, pp. 620 & 623; Farbe + Lack, 96 years, 9/1990, pp. 689 & 693). The tetramethylpiperidine group present in the HALS compound serves for the stabilization of the HALS compound. Such compounds may be unsubstituted at the piperidine nitrogen or substituted thereon by an alkyl or acyl group. The sterically hindered amines do not absorb in the UV range. They trap the free radicals formed, which the UV absorbers are not able to exert.

Examples of stabilizing HALS compounds (which can also be used in mixtures) are:

bis (2, 2, 6, 6-tetramethyl-4-piperidyl) sebacate, 8-acetyl-3-dodecyl-7, 7, 9, 9-tetramethyl-1, 3, 8-triazaspiro (4, 5) decane-2, 5-dione, bis (2, 2, 6, 6-tetramethyl-4-piperidyl) succinate, poly- (N-. beta. -hydroxyethyl-2, 2, 6, 6-tetramethyl-4-hydroxypiperidine succinate) or bis- (N-methyl-2, 2, 6, 6-tetramethyl-4-piperidyl) sebacate.

The amount of free-radical scavengers/UV stabilizers used in the molding compositions according to the invention is from 0.01 to 1.5% by weight, in particular from 0.02 to 1.0% by weight, and especially from 0.02 to 0.5% by weight, based on the sum of all constituents.

A lubricant orRelease agent

Lubricants or mold release agents are particularly important for injection molding processes, which can reduce or completely prevent possible adhesion of the molding composition to the injection mold.

Thus, lubricants selected, for example, from the group consisting of those containing less than C may be included as adjuvants₂₀Preferably C₁₆-C₁₈Saturated fatty acids of carbon atoms, or containing less than C₂₀Preferably C₁₆-C₁₈Saturated aliphatic alcohols of carbon atoms. Preferably there is a small quantitative ratio: up to 0.25% by weight, for example from 0.05 to 0.2% by weight, based on the molding composition.

Suitable are, for example, stearic acid, palmitic acid, technical mixtures of stearic acid and palmitic acid. Also suitable are, for example, n-hexadecanol, n-octadecanol, and also technical mixtures of n-hexadecanol and n-octadecanol.

Stearyl alcohol is a particularly preferred lubricant or mold release agent.

Volume melt index MVR of the Molding composition

Within the scope of the invention, the molding composition has a volume melt index MVR of 0.1cm, measured at 230 ℃ and 3.8kg according to ISO 1133³/10min-5.0cm³And/10 min. The MVR measured here at 230 ℃ and 3.8kg according to ISO 1133 is preferably at least 0.2cm³A/10 min, particularly preferably at least 0.3cm³10min, advantageously at least 0.4cm³A/10 min, in particular at least 0.5cm³And/10 min. In addition, the MVR measured at 230 ℃ and 3.8kg according to ISO 1133 is preferably less than 3.5cm³A/10 min, particularly preferably less than 3.0cm³10min, advantageously less than 1.5cm³10min, very particularly preferably less than 1.4cm³A/10 min, in particular less than 1.1cm³A/10 min, most preferably less than 0.9cm³And/10 min. In the case of molding compositions comprising impact modifiers, the MVR, measured according to ISO 1133 at 230 ℃ and 3.8kg, is preferably 0.1cm³/10min-3.0cm³And/10 min. In the case of molding compositions without impact modifier, the MVR, measured according to ISO 1133 at 230 ℃ and 3.8kg, is preferably 0.5cm³/10min-5.0cm³/10min。

Preparation of the moulding compositions according to the invention

The molding compositions of the invention can be prepared via dry blending of the components, which can be present in the form of powders, granules or preferably pellets. They can also be prepared via melting and mixing in the molten state of the polymer matrix and optional impact modifier, or via melting of dry premixes of the individual components and addition of ceramic beads. This can be carried out, for example, in a single-or twin-screw extruder. The extrudate obtained can then be granulated. Conventional additives, auxiliaries and/or fillers may be incorporated directly or subsequently by the end user as desired.

Processing to obtain a moulded article

The molding compositions according to the invention are suitable as starting materials for the production of moldings having a velvety matt, preferably rough, surface. The shaping of the molding compositions can be carried out in a manner known per se, for example by processing via the viscoelastic state, i.e.by kneading, rolling, calendering, extrusion or injection molding, preference being given to extrusion and injection molding, in particular extrusion, in the present invention.

The injection molding of the molding compositions can be carried out in a manner known per se at temperatures of from 220 ℃ to 260 ℃ (bulk (Masse) temperature) and at mold temperatures of preferably from 60 ℃ to 90 ℃. When a mold having a mold cavity with a smooth or polished inner surface (cavity) is used, a matte molded article is obtained. When a mold having a cavity with a rough inner surface (cavity) is used, the resulting molded article is more deeply matt.

The extrusion is preferably carried out at a temperature of 220 ℃ to 260 ℃.

Molded article

The moldings obtainable in this way preferably exhibit the following properties:

roughness value R according to DIN 4768_zAdvantageously greater than or equal to 0.3. mu.m, preferably at least 0.7. mu.m, particularly preferably between 2.5 and 20.0. mu.m. The gloss (R60 ℃) to DIN 67530(01/1982) is preferably up to 45%, particularly preferably up to 38%. The light transmission to DIN 5036 is preferably from 40% to 93%, particularly preferably from 55% to 93%, in particular from 55% to 85%. The half-strength angle to DIN 5036 is preferably from 1 to 55 °, particularly preferably from 2 to 40 °, in particular from 8 to 37 °.

Within the scope of the first particularly preferred embodiment of the present invention, the Vicat softening temperature VET (ISO 306-B50) of the moldings is preferably at least 90 ℃, particularly preferably at least 95 ℃, very particularly preferably at least 100 ℃, advantageously from 90 ℃ to 170 ℃, in particular from 102 ℃ to 130 ℃. The moldings furthermore preferably have one or more, particularly preferably as many, of the following properties:

I. a breaking stress according to ISO 527(5mm/min) of at least 50MPa, in particular 65MPa to 90MPa,

modulus of elasticity according to ISO 527 of greater than 3200MPa,

III, greater than 20kJ/m²Impact resistance according to ISO 179/1eU, and

less than 8X 10^-5/° K, particularly preferably less than 7.1 × 10^-5Coefficient of linear expansion according to ISO 11359,/° K.

These moldings are usually obtained from molding compositions which do not comprise impact modifiers.

Within the scope of the second particularly preferred embodiment of the present invention, the Vicat softening temperature VET (ISO 306-B50) of the moldings is preferably at least 90 ℃, particularly preferably at least 95 ℃, advantageously from 90 ℃ to 170 ℃, in particular from 95 ℃ to 110 ℃. The moldings furthermore preferably have one or more, particularly preferably as many, of the following properties:

I. a yield stress according to ISO 527(50mm/min) of at least 30MPa, in particular 34MPa to 50MPa,

modulus of elasticity according to ISO 527 of greater than 1400MPa,

III, greater than 4kJ/m²Notched impact resistance according to ISO 179/1eU, and

less than 12X 10^-5Coefficient of linear expansion according to ISO 11359,/° K.

These moldings are usually obtained from molding compositions which comprise at least one impact modifier.

Use of

The moldings of the invention can be used in particular as components of domestic appliances, communication appliances, hobby appliances or sports appliances, as or as part of body components in automobile construction, ship construction or aircraft construction, as components of luminaires, signs or symbols, retail markets or cosmetic counters, containers, home or office furnishings, furniture applications, shower doors and office doors, and as components in the construction industry, in particular sheets, as walls, in particular as sound insulation, as window frames, bench seats, lamp shades, diffusers and for automotive glazing. Typical exterior parts of automobiles are, for example, spoilers, sun visors, roof modules or exterior mirror housings.

Detailed Description

Examples

The invention is further illustrated by the following examples, but the inventive concept is not thereby limited.

From Roehm GmbH7H、8N、zk6BR and8908F was used as the polymer matrix.

The products Zeeospheres W-210, W-410, G-200 and G-400 from the company 3M Deutschland GmbH were used as ceramic beads.

The components were blended by a single screw extruder. The compositions of the various examples are reported in table 1.

The volume flow index MVR (test standard ISO 1133: 1997) and the density of the molding compositions were determined.

Test pieces were prepared from the blended molding compositions by injection molding and strip extrusion. In the case of strip extrusion or in the case of injection molding, no metal wear was observed during processing. The corresponding test pieces were tested as follows:

injection molded article

Vicat (16h/80 ℃ C.): determination of the Vicat softening temperature (test Standard DIN ISO 306: month 8 1994)

KSZ (Charpy 179/1 eU): determination of Charpy notched impact resistance (test Standard: ISO 179: 1993)

SZ (Charpy 179/1 eU): determination of the Charpy impact resistance (test Standard: ISO 179: 1993)

Modulus of elasticity: determination of the modulus of elasticity (test Standard: ISO 527-2)

Tensile strength: determination of the stress at break (test Standard: ISO 527; 5mm/min), the stress at yield (test Standard: ISO 527; 50mm/min) and/or the tensile strain at yield (test Standard: ISO 527; 50mm/min)

Light transmittance (T): according to DIN 5036

Half intensity angle (IHW): measurement according to DIN 5036 using LMT goniometer measuring device GO-T-1500 from LMT

Coefficient of linear expansion: ISO 11359(0 ℃ C. to 50 ℃ C.)

Scratch hardness: according to Erichsen 413

Strip:

surface roughness: roughness parameters Ra, Rz and Rt according to DIN 4768. The Ra value is < 2 μm determined using a cut-off length (cut off) of 0.8mm, and if Ra.gtoreq.2 μm, a cut-off length of 2.5mm is used. FormTalyurf 50, manufactured by Rank Taylor Hobson GmbH, was used to make the roughness measurements.

Gloss: according to DIN 67530 (01/1982): "reflektomer alsHilfsmittel zur Glanzbeurteinung an ebenen Antrich-undKunststoff-"measure gloss.

The results of the tests on the blends and the corresponding moldings are given in Table 2. The improvements achieved by the present invention are evident:

by using ceramic beads as matting agents, it is possible to extrude from the corresponding molding compositions tapes with a lower gloss and a uniformly fine-matted surface, and an attractive surface roughness. Improved scattering effects are also observed, as well as a reduction in the coefficient of expansion and an improvement in the mechanical properties, such as impact resistance, notched impact resistance, modulus of elasticity and scratch resistance.

Table 1: composition of the Molding composition

¹：D₅₀：3μm，D₉₅：12μm；²：D₅₀：4μm，D₉₅：24μm，³：D₅₀：4μm，D₉₅：12μm，⁴：D₅₀：5μm，D₉₅：24μm

Table 1 (next): composition of the Molding composition

Claims (28)

1. A molding composition comprising, based in each case on the total weight of the molding composition:

A) from 49.5% by weight to 99.5% by weight of a polymer matrix consisting of (meth) acrylate (co) polymers or of a mixture of (meth) acrylate (co) polymers,

B)0.5 wt% to 15.0 wt% ceramic beads,

it is characterized in that

The volume of the moulding composition measured according to ISO 1133 at 230 ℃ and 3.8kgMelt index MVR of 0.1cm³/10min-5.0cm³/10min。

2. Moulding composition according to claim 1, characterized in that the ceramic beads are not covalently bonded to the polymer matrix.

3. Moulding composition according to claim 1 or 2, characterised in that the median diameter of the ceramic beads, as D₅₀The value measured was 1.0 μm to 15.0. mu.m.

4. Moulding composition according to at least one of the preceding claims, characterized in that the median diameter of the ceramic beads, as D₉₅The value measured was 3 μm to 35 μm.

5. Moulding composition according to at least one of the preceding claims, characterized in that the density of the ceramic beads is 2.1g/cm³-2.5g/cm³。

6. Moulding composition according to at least one of the preceding claims, characterized in that the ceramic beads comprise the following, in each case based on their total weight:

55.0-62.0 wt% SiO₂，

21.0-35.0 wt.% Al₂O₃，

Up to 7.0 wt.% Fe₂O₃，

Up to 11.0 wt.% Na₂O, and

up to 6.0 wt.% K₂O。

7. Moulding composition according to at least one of the preceding claims, characterized in that the ceramic beads have a surface area of 0 measured according to the BET nitrogen adsorption method.8m²/g-2.5m²/g。

8. Moulding composition according to at least one of the preceding claims, characterized in that the ceramic beads are hollow on the inside.

9. Moulding composition according to at least one of the preceding claims, characterized in that the moulding composition comprises, based on its total weight, from 0.1 to 50.0% by weight of at least one impact modifier C) which is not covalently bonded to the polymer matrix.

10. Moulding compositions according to claim 9, characterized in that the impact modifier C) contains poly (meth) acrylate units.

11. Moulding compositions according to claim 9 or 10, characterized in that the impact modifier C) has a two-or three-shell structure.

12. Moulding composition according to at least one of the preceding claims, characterized in that the polymer matrix A) comprises a (meth) acrylate (co) polymer consisting of 96.0 to 100.0% by weight of methyl methacrylate and 0.0 to 4.0% by weight of methyl acrylate, ethyl acrylate and/or butyl acrylate.

13. Moulding composition according to at least one of the preceding claims, characterized in that the polymer matrix A) comprises a copolymer of methyl methacrylate, styrene and maleic anhydride.

14. Moulding compositions according to claim 13, characterized in that the polymer matrix a) comprises copolymers consisting of:

50-90% by weight of methyl methacrylate,

10 to 20% by weight of styrene and

5-15% by weight of maleic anhydride.

15. Moulding composition according to at least one of the preceding claims, characterized in that the moulding composition comprises the following components:

d) a low molecular weight (meth) acrylate (co) polymer characterized by a solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) less than or equal to 55 ml/g;

e) higher molecular weight (meth) acrylate (co) polymers characterized by a solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) greater than or equal to 65ml/g and/or

f) A (meth) acrylate (co) polymer other than d), characterized in that the solution viscosity in chloroform at 25 ℃ (ISO 1628-part 6) is from 50ml/g to 55ml/g,

wherein components d), e) and/or f) can each be referred to by themselves as a single polymer or as a mixture of polymers.

16. Moulding composition according to one or more of the preceding claims, characterized in that the moulding composition has a volume melt index MVR of 0.1cm measured according to ISO 1133 at 230 ℃ and 3.8kg³/10min-3.0cm³/10min。

17. Moulding composition according to one or more of claims 1 to 15, characterised in that the moulding compositionHas a volume melt index MVR of 0.5cm measured according to ISO 1133 at 230 ℃ and 3.8kg³/10min-5.0cm³/10min。

18. Moulding composition according to one or more of the preceding claims, characterized in that a lubricant is contained as an auxiliary.

19. Moulding compositions according to claim 18, characterized in that stearyl alcohol is included as lubricant.

20. Moulding composition according to one or more of the preceding claims, characterized in that it is in the form of moulding composition pellets.

21. Process for producing moldings, characterized in that a molding composition according to one or more of the preceding claims is shaped.

22. The process according to claim 21, characterized in that the molding composition is extruded or injection molded.

23. A moulded article capable of being prepared according to the process of claim 21 or 22.

24. The molding according to claim 23, characterized in that it has a roughness value Rz according to DIN 4768 of at least 0.3 μm and a gloss value (R60 °) according to DIN 67530 of at most 45.

25. The molding according to claim 23, characterized in that its light transmission according to DIN 5036 is from 40% to 93% and its half-strength angle according to DIN 5036 is from 1 ° to 55 °.

26. The molding according to claim 23, 24 or 25, characterized in that it has one or more of the following properties:

a. a Vicat softening temperature according to ISO 306-B50 of at least 90 ℃,

b. a breaking stress according to ISO 527 at 5mm/min of at least 50MPa,

c. an elastic modulus according to ISO 527 of more than 3200MPa,

d. greater than 20kJ/m²Impact resistance according to ISO 179/1eU, and

e. less than 8 x 10^-5Coefficient of linear expansion according to ISO 11359,/° K.

27. The molding according to claim 23, 24 or 25, characterized in that it has one or more of the following properties:

a. a Vicat softening temperature according to ISO 306-B50 of at least 90 ℃,

b. a yield stress according to ISO 527 at 50mm/min of at least 30MPa,

c. an elastic modulus according to ISO 527 of more than 1400MPa,

d. greater than 4kJ/m²Notched impact resistance according to ISO 179/1eU, and

e. less than 12 x 10^-5Coefficient of linear expansion according to ISO 11359,/° K.

28. Use of the molded articles according to one or more of claims 23 to 27 as parts of domestic, telecommunications, hobby or sports equipment, as body parts or parts of body parts in automotive, marine or aircraft construction, as luminaries, signs or symbols, retail markets or cosmetic counters, containers, home or office furnishing items, furniture applications, shower and office doors, as parts in the building industry, as walls, as window frames, bench seats, lamp covers, diffusers and for glazing in automobiles.