DE10254276A1 - Process for producing a plastic plate with a layered structure - Google Patents

Abstract

The present invention relates to a process for producing a plastic sheet having a laminar structure in which an acrylic resin is polymerized in the chamber process between two outer plastic sheets, wherein the thickness ratio of the two outer plastic sheets in the range of greater than or equal to 2: 3 to less than or equal to 3: 2 and produces by the polymerization, an acrylic glass intermediate layer having a thickness of at least 2 mm.

Description

The present invention relates a process for producing plastic sheets with a layered structure, in particular of two- or multi-colored plastic plates with layered Construction.

Two or more colored plastic plates with layered Construction are already known and are sometimes called bi-color or multicolor plates. They are special at the moment in the field of illuminated advertising, the furniture industry, for example for delusions, and for the shop and exhibition construction used.

The production of these Bicolor- or Up to now, multicolor plates are usually made by surface bonding or by rolling, but this approach with several Disadvantages.

The surface bonding of different colored Plastic plates leads to a visible at least from the front side adhesive seam, which often has a yellow tinge and in this way the overall visual impression the plastic plate with a layered structure is sensitive.

Furthermore, the adhesive layer between the two plastic plates a comparatively high residual monomer content on, the thermal stress, as for example in the further processing of the plastic plate with a layered structure Occurs (eg laser cutting) to a blistering at the adhesive edge to lead can. For this reason, the glued seam usually needs after the Bonding tempered by annealing are often the high residual monomer content, a white discoloration of the adhesive surface conditionally.

Another disadvantage of Fächenverklebung is to be seen in that mistakes in the production of the adhesive as well as in the implementation the bonding extremely on the quality the resulting plastic plate with a layered structure impact. So can Error in the production of the adhesive, such as in the Setting the ratio of hardener (Catalyst) to adhesive, deviation error, error in calculation the needed Amount of adhesive as well as uneven application the adhesive quickly cause insufficient surface bonding and in this way the material properties of the resulting plastic plate with layered Construction worsen significantly. An uneven bonding is beyond from the viewer as visually disturbing felt.

In the area bonding persists the danger that by water absorption of the adhesive a "sword" or "bowl effect" occurs, which a crowning (warping) the plastic plate with layered structure after one or results in both directions.

Another disadvantage of surface bonding, in the context of the present invention particularly in the foreground stands, is the fact that this procedure for the production of large-format plastic bicolor or multicolor plates only conditionally suitable because they are common to blistering in the adhesive surface and in this way too a deterioration of the mechanical and optical properties the plastic bicolor or multicolor plates leads and thus a high reject rate.

As an alternative to Flächenverklebung is also the rolling of plastic plates to the desired bicolour or multicolor plastic plate from the German patent applications DE 44 39 419 and DE 44 39 420 known. However, this method is also not suitable for the production of large-sized plastic sheets with a layered structure greater than DIN A2, because in this case too fast cooling would take place on the surface, so that the desired fusion of the plastic plates is not achieved. Furthermore, thin rolled boards, in particular those with a single board thickness of less than 6 mm, tend to be troubled and, for this reason, unusable for various applications. In asymmetric composites also a delay (bowl effect) can be observed by unequal dissipation of the heat. The production of thick plates requires long periods of heating and thus high energy costs. Furthermore, older plates must be dried before the process in order to avoid a crowning (warping) due to the amount of water absorbed.

In addition to the methods described above (surface bonding and rolling) is from the Japanese patent application JP 01-138211 A2 discloses a process for the production of an acrylic sheet in which a colored polymerizable composition of methyl methacrylate, Sumipex B-LG (I), Sumiplast blue S (dye), Sumiplast green G, Sumiplast red HL BB (dye), BaSO ₄ ( Table frame tableware) and AIBN polymerized in the chamber process between two polymethyl methacrylate plates, wherein the one plate has a thickness of 2 mm and the other has a thickness of 3 mm. A disadvantage of this approach, however, is that a warped in the direction of the thinner plate acrylic glass plate is obtained. This curvature is due to the findings of the present invention due to the use of PMMA plates with significantly different mechanical stability.

In addition, in the case of this Reference to proposed method for producing bicolor plates problematic that one is colored by the addition of pigments composition polymerized between two colorless acrylic sheets, there on this way, irregularities in the thickness of the intermediate layer as well as inhomogeneities (cloud formation) by different strong staining be clearly visible immediately. It is therefore with a relative high amount of rejects.

In view of the above and described prior art, it was therefore an object of the present invention, a method for joining plastic sheets to provide the production of, preferably multi-colored, not warped Plastic sheets with layered Construction allowed. These should preferably have such a planarity that the bulge the plastic plates with a layered structure, measured analogously the standard EN ISO 12017, at most 3 mm relative to a length of 1 m.

Another task of the present The invention was also to be seen therein, a method for joining from plastic plates to provide, which is the manufacture a perfect plastic plate with a layered structure according to optical criteria allows. In particular, the obtainable by the process according to the invention should Plastic plate with layered Structure as possible have no visible from the front side adhesive seam and a yellowing the connecting layer as well as the formation of bubbles between the Plastic plates should also be avoided if possible.

In addition, the inventive method should in particular for the production of bicolor or multicolor plates be suitable and thereby preferably a uniform dyeing of respective outer plastic plates enable.

Another task of the present The invention was a method for joining plastic sheets which also includes the production of large formats, in particular of Formats larger than DIN A2 allowed in a simple way.

The present invention was further The object is based on a process for the production of plastic plates with layered Structure with different surface structures, such as smooth, matt and / or textured, accessible close. It should as possible Different surface structures can be realized on both sides his.

The present invention was still The object is based on a process for the production of plastic plates with layered Construction accessible to make, where the two outer plastic plates either of the same material or of different polymers consist. It should as possible also with mineral fillers and / or with other functional additives (eg flame retardants) equipped panels can be used, either for one or for both outsides the invention produced Plastic sheets with layered Construction.

It was also the task of the present Invention to provide a method for joining plastic sheets which in a simple way, on a large scale, inexpensively and preferably environmentally friendly feasible is.

Furthermore, an object of the present invention Invention therein, a method for joining plastic sheets ready to provide, which is the production of plastic plates with layered Construction with improved mechanical properties allowed. The Further processing of the plastic plates produced by this process with layered Construction should be as possible simple and uncomplicated, such as the editing of normal mono plates, his. In particular, the above in connection with the surface bonding mentioned problems in laser cutting can be avoided.

These tasks are solved as well other tasks that were not specifically mentioned in detail, the However, from the introductory discussion of the prior art readily accessible or as a matter of course Derive by a process for producing a plastic plate with layered Structure with all features of claim 1. Advantageous embodiment the method according to the invention are the subject of the independent claim Claims.

By doing a procedure for Producing a plastic plate with a layered structure, in which one polymerizes an acrylic resin in the chamber process between two outer plastic plates, the process being characterized in that the thickness ratio of the two outer plastic plates in the range of greater or equal to 2: 3 to less than or equal to 3: 2 and by polymerization an acrylic glass intermediate layer produced with a thickness of at least 2 mm, it succeeds in surprising Way, a method for producing a plastic plate with a layered structure specify the manufacture of a non-warped plastic plate with layered Construction in a simple way allowed. In this case, the plastic plate with layered Build up usually such a planity on that the bulge of the Plastic sheets with layered Construction, measured in accordance with the standard EN ISO 12017, at the most 3 mm in relation to one length of 1 m.

• – Die durch das erfindungsgemäße Verfahren erhältlichen Kunststoff-Platten mit schichtförmigem Aufbau sind nach optischen Gesichtpunkten perfekt. Sie weisen insbesondere keine den optischen Gesamteindruck störende Klebenaht auf. Eine Gelbverfärbung der verbindenden Zwischenschicht sowie eine Blasenbildung in der Zwischenschicht ist ebenfalls nicht zu beobachten.
• – Das erfindungsgemäße Verfahren eignet sich insbesondere zur Herstellung von Bicolor- und Multicolor-Platten.
• – Es können unterschiedliche Oberflächenstrukturen, wie beispielsweise glatt, matt und/oder strukturiert, sowohl einseitig als auch beidseitig realisiert werden.
• – Das erfindungsgemäße Verfahren erlaubt auch die Herstellung von Großformaten größer DIN A2 auf einfache Art und Weise. Dabei wird insbesondere das Problem der Blasenbildung vermieden.
• – Durch das erfindungsgemäße Verfahren werden die Materialeigenschaften der resultierenden Kunststoff-Platte mit schichtförmigem Aufbau nicht nachteilig beeinflusst. Im Gegenteil die mechanischen Eigenschaften der durch das erfindungsgemäße Verfahren erhältlichen Kunststoff-Platten mit schichtförmigem Aufbau entsprechen den von Monoplatten vergleichbarer Zusammensetzung und Dicke, d. h. ihre Weiterverarbeitung kann wie bei normalen Monoplatten erfolgen. Insbesondere sind keine Nachteile beim Laserschneiden usw. zu beobachten.
• – Das erfindungsgemäße Verfahren kann auf besonders einfache Art und Weise großtechnisch, kostengünstig und umweltverträglich durchgeführt werden. Insbesondere wird durch das geschlossene Kammersystem eine Emissionsbelastung während der Produktion vermieden.

In addition, numerous further advantages can be achieved by the procedure according to the invention. These include:

• - The obtainable by the process according to the invention plastic plates with a layered structure are perfect for optical aspects. In particular, they have no adhesive seam disturbing the overall visual impression. A yellow discoloration of the connecting intermediate layer as well as a blistering in the intermediate layer is also not observed.
• - The inventive method is particularly suitable for the production of Bicolor- and Multico lor-plates.
• - Different surface structures, such as smooth, matt and / or textured, can be realized both on one side and on both sides.
• - The inventive method also allows the production of large formats greater than DIN A2 in a simple manner. In particular, the problem of blistering is avoided.
• - By the method according to the invention, the material properties of the resulting plastic sheet having a layered structure are not adversely affected. On the contrary, the mechanical properties of the plastic sheets with a layered structure obtainable by the process according to the invention correspond to those of monoplates of comparable composition and thickness, ie their further processing can be carried out as in the case of normal monoplates. In particular, no disadvantages in laser cutting, etc. are observed.
• - The inventive method can be carried out in a particularly simple manner on an industrial scale, cost and environmentally friendly. In particular, an emission load during production is avoided by the closed chamber system.

For the purposes of the present invention suitable plastic substrates are known per se. Such substrates include in particular Polycarbonates, polystyrenes, polyesters, for example polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyether, cycloolefinic Polymers (COC), ABS, nylon, PVC and / or poly (meth) acrylates.

Polycarbonates are in the art known. Polycarbonates can formally as carbonated polyester and aliphatic or aromatic dihydroxy compounds. she are easily accessible by reacting diglycols or bisphenols with phosgene or Carbonic acid diesters in polycondensation or transesterification reactions.

Polycarbonates are preferred here, which are derived from bisphenols. These bisphenols include in particular 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxyphenyl) butane (Bisphenol B), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol C), 2,2'-methylene diphenol (Bisphenol F), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane (tetrabromobisphenol A) and 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane (tetramethyl bisphenol A).

Usually Such aromatic polycarbonates are prepared by interfacial polycondensation or Transesterification, details in Encycl. Polym. Sci. Engng. 11, 648-718 are shown.

Polycarbonate molding compounds are, for example available under the tradename Makrolon from Bayer or ®Lexan from General Electric.

Cycloolefinic polymers are polymers, using cyclic olefins, in particular polycyclic ones Olefins available are.

Cyclic olefins include, for example monocyclic olefins, such as cyclopentene, cyclopentadiene, cyclohexene, Cycloheps, cyclooctene and alkyl derivatives of these monocyclic Olefins having 1 to 3 carbon atoms, such as methyl, ethyl or propyl, such as methylcyclohexene or dimethylcyclohexene, as well as Acrylate and / or methacrylate derivatives of these monocyclic compounds. About that also can Cycloalkanes with olefinic side chains as cyclic olefins used, such as cyclopentyl methacrylate.

Preference is given to bridged, polycyclic Olefin. These polycyclic olefin compounds may be the Have double bond both in the ring, it is here around bridged polycyclic cycloalkenes, as well as in side chains. This acts these are vinyl derivatives, allyloxycarboxy derivatives and (meth) acryloxy derivatives of polycyclic cycloalkane compounds. These compounds can be the have further alkyl, aryl or aralkyl substituents.

Illustrative polycyclic compounds include, but are not limited to, bicyclo [2.2.1] hept-2-ene (norbornene), bicyclo [2.2.1] hept-2,5-diene (2,5-norbornadiene), ethyl -Bicyclo [2.2.1] hept-2-ene (ethylnorbornene), ethylidenebicyclo [2.2.1] hept-2-ene (ethylidene-2-norbornene), phenylbicyclo [2.2.1] hept-2-ene, bicyclo [4.3 .0] nona-3,8-diene, tricyclo [4.3.0.1 ² ' ⁵ ] -3-decene, tricyclo [4.3.0.1 ² ' ⁵ ] -3,8-decene- (3,8-dihydrodicyclopentadiene), tricyclo [4.4.0.1 ^2,5 ] -3-undecene, tetracyclo [4.4.0.1 ² ' ⁵ , 1 ^7,10 ] -3-dodecene, ethylidene-tetracyclo [4.4.0.1 ² ' ⁵ , 1 ^7,10 ] -3 dodecene, Methyloxycarbonyltetracyclo [4.4.0.1 ^2,5, 1 ^7,10] -3-dodecene, ethylidene-9-ethyltetracyclo [4.4.0.1 ^{2 '5,} 1 ^7,10] -3-dodecene, pentacyclo [4.7.0.1 ² ' ⁵ , O, O ^{3 , 13} , 1 ⁹ ' ¹² ] -3-pentadecene, pentacyclo [6.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] -4-pentadecene, hexacyclo [6.6.1.1 ^{3 , 6} .1 ^10,13 .0 ^2,7 .09 ^9,14 ] -4-heptadecene, dimethylhexacyclo [6.6.1.1 ^{3 , 6} .1 ^10,13 .0 ^2,7 .09 ^9,14 ] -4 -heptadecen, bis (allyloxycarboxy) tricyclo [4 .3.0.1 ² ' ⁵ ] decane, bis (methacryloxy) tricyclo [4.3.0.1 ^2,5 ] decane, bis (acryloxy) tricyclo [4.3.0.1 ^{2 , 5} ] decane.

The cycloolefinic polymers are using at least one of the previously described cycloolefinic Compounds, in particular polycyclic hydrocarbon compounds produced. About that can out in the preparation of the cycloolefinic polymers further olefins used with the aforementioned cycloolefinic Monomers can be copolymerized. These include u.a. Ethylene, propylene, isoprene, butadiene, methylpentene, styrene and vinyltoluene.

Most of the aforementioned olefins, especially the cycloolefins and polycycloolefins, can be commercial to be obtained. About that In addition, many cyclic and polycyclic olefins are by Diels-Alder addition reactions available.

The preparation of the cycloolefinic polymers can be carried out in a known manner, as described, inter alia, in Japanese Patent Nos. 11818/1972, 43412/1983, 1442/1986 and 19761/1987 and Japanese Patent Laid-Open Nos. 75700/1975, 129434/1980, 127728 / 1983, 168708/1985, 271308/1986, 221118/1988 and 180976/1990 and in the European patent applications EP-A-0 6 610 851 . EP-A-0 6 485 893 . EP-A-0 6 407 870 and EP-A-0 6 688 801 is shown.

The cycloolefinic polymers may be, for example using aluminum compounds, vanadium compounds, Tungsten compounds or boron compounds as a catalyst in one solvent be polymerized.

Molding compounds which are cycloolefinic Include polymers for example under the trade name ®Topas of Ticona and ®Zeonex of Nippon Zeon.

The polyesters used are generally thermoplastic polyalkylene terephthalates, such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), with average molecular weights M _w , between 5 x 10 ³ and 2 x 10 ⁵ g / mol (for polyesters see, for example, Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Vol. 18, pp. 549-574, J. Wiley, New York, 1982).

As polyamides are in general amorphous polyamides of the nylon type used, such as. B. copolyamides or polyamides having branched alkylene groups in the polymer chain (For polyamides, see, for example, Kirk-Othmer, loc.cit., Vol. 18, pages 328 to 371).

Furthermore, the plastics from the Group of amorphous aromatic polyethers, the polyketones and polysulfones lock in, selected his. Exemplary for aromatic polyethers may be mentioned: polyphenylene oxides, polyethersulfones, Polyether ketones or polyetherimides (to aromatic polyethers see. for example, Kirk-Othmer, loc. cit., Vol. 18, pages 594 to 615).

Another plastic substrate includes Poly (meth) acrylates. Such plates are known in the art already known and refer to plastic plates, which consists essentially of consist of one or more poly (meth) acrylates. These polymers are generally by radical polymerization of mixtures obtained containing (meth) acrylates. The term (meth) acrylates includes methacrylates and acrylates as well as mixtures of both.

The poly (meth) acrylates are preferably from polymers of methyl methacrylate, up to 50 wt .-% of other, copolymerizable with methyl methacrylate monomers could be. Preferably the proportion of methyl methacrylate 80 to 100 wt .-%. As comonomers are primarily alkyl acrylates having 1 to 6 carbon atoms in the alkyl ester, alkyl and / or methacrylonitrile, styrene and / or substituted styrenes and maleic anhydride into consideration.

For example, thermoplastically or thermoelastically deformable poly (meth) acrylates of the above composition having specific viscosities to DIN 51562 in chloroform at 25 ° C. in the range between 20 and 1000 ml / g, corresponding to approximate average molecular weights M _W between 3 × 10 ⁴ and may be used about 5 × 10 ⁶ g / mol.

In the same way but also be used as a poly (meth) acrylate cast material, which produced in the chamber process or as so-called strip material can be. (See H. F. Mark et al., Encyclopedia of Polymer Science & Engineering. 2nd. Ed. Vol. 1, 276-278, J. Wiley 1985).

The used poly (meth) acrylate plastic plates can optionally modified appropriately, for. B. crosslinked, with known stabilizers or other Additives z. B. flameproof or antistatic. Furthermore, can she at the later outsides the layered be built scratch-resistant plates (see Ullmann's Encyclopedia of Industrial Chemistry 5th Ed., Vol A20, 459-507, VCH 1992).

Molding compounds, the poly (meth) acrylates are commercially available under the trade name PLEXIGLAS® from Degussa AG available.

According to a further embodiment, impact-modified poly (meth) acrylates which have an impact strength according to ISO 179/1 of at least 10 kJ / m ² , preferably of at least 15 kJ / m ² , can be used as plastic substrates.

Preferred plastic substrates for the outer plastic plates are polycarbonates, cycloolefinic polymers and poly (meth) acrylates, wherein poly (meth) acrylates are particularly preferred.

According to a preferred embodiment Can be at least one of the outer plastic plates a mineral filler or contain a functional additive.

Suitable fillers are the inorganic materials used in casting resins, such as, for example, aluminum oxides, alkali and / or alkaline earth oxides, silicon dioxide and / or titanium dioxide in various modifications, clays, silicates, oxides, carbon, metals or metal alloys, synthetic materials such as ceramics, glass powder , Porcelain, slag or finely divided silica, quartz, kaolin, talc, mica, feldspar, apatite, barytes, gypsum, chalk, limestone, dolomite or mixtures of the above and below mentioned components. Preference is given to using inorganic materials which, on heating, remove flame-retardant, generally gaseous substances, such as, for example, water, carbon dioxide or sulfur trioxide. These include, for example, inorganic compounds with water of hydration, alkaline earth hydroxides, aluminum hydroxides, metal hydroxides, carbonates, bicarbonates, phosphates, sulfides, hyposulfides, hypophosphates, boric acid derivatives and the like. It is particularly preferable to use aluminum hydroxide and alumina hydrate.

It is useful in the inorganic fillers an average grain size of the filler particles of 100 μm (Diameter), preferably not exceeded by 75 microns.

The filler can also be a mixture of at least 2 components whose average average grain sizes are so obtained are that a size ratio between the mean average grain sizes of the large filler particles and those the small filler particles between 10: 1 and 2: 1, preferably between 6: 1 and 4: 1. filler with a particle size <0.1 microns not more than 10% of the volume of all filler particles. The particle size is according to the usual procedures determined, wherein for particle size determination the largest dimensions the particles are used (see, for example, B. Scarlett, Filtration & separation, Page 215, 1965). The quantity ratio between big ones and small filler particles is generally between 4: 1 and 1: 4, preferably between 2: 1 and 1: 2, more preferably 1: 1.

Preferably, the inorganic filler is such that the cured casting resin has an elastic shear modulus of at least 5 GNm ^-2 , preferably of at least 10 GNm ^-2 , wherein the intended use of the casting resins is to be kept in mind when adjusting the mechanical properties.

The filler content of the filled plastic plates is usually at least 40 wt .-%. In general, a share of 80% by weight not exceeded, as a guideline a filling content from 50 to 80 wt .-% is given. The production of fillers in the appropriate particle sizes take place by the known methods, for example by breaking and grinding.

The outer plastic plates may contain one or more functional additives. Their proportion, depending on the property to be achieved, may be from 10 ^-3 to 20% by weight, based on the weight of the outer plastic plate.

As functional additives are common plastic additives, such as light stabilizers, thermal stabilizers Decomposition, lubricants, antistatic agents, antioxidants, mold release agents, flame retardants, Lubricants, flow improvers, organic phosphorus compounds, such as phosphites, phosphininanes, phospholanes or phosphonates, pigments, Weathering agents and plasticizers in question.

In an advantageous embodiment exist the two outer plastic plates from the same polymer, one of which is unmodified Polymer and the other of the polymer containing at least one filler and / or functional excipient. In a preferred embodiment Both plates have the identical composition, in one particularly preferred embodiment These two plates still have the same thickness.

According to the present invention the production of the plastic plate with a layered structure, by placing an acrylic resin in the chamber between two outer plastic plates polymerized. In this case, the outer plastic plates according to the invention are not subject special restrictions. On the contrary, it can the known, usually commercially available plastic plates be used.

For however, the purposes of the present invention have been exhaustive very cheap proved that you have two outer plastic plates which each independently from each other a thickness in the range of 1 to 7 mm, preferably in Range from 3 to 5 mm.

The manner of making the outer plastic sheets is generally not critical to the purposes of the present invention. These can be produced in a manner known per se, for example by extrusion or by casting. However, in the context of the present invention, plastic sheets which have been obtained by a casting method, preferably in the chamber method, have proven particularly useful. Very particularly advantageous results may be obtained using PLEXIGLAS ^® GS sheets of Messrs. Rohm GmbH & Co. KG are obtained.

As part of a very preferred embodiment The present invention provides at least one colored, outer plastic plate used. Such plastic plates can be used per se known pigments, which in the range of visible light (380 to 700 nm) and in this way the complementary color impression evoke the viewer. For more details will be on the common ones Specialist literature, for example on Römpp Lexikon Chemie, Version 2.0, Stuttgart / New York, Georg Thieme Verlag, 1999 and there cited publications.

The thickness ratio of the two outer plastic plates is in the context of the present invention is of central importance. This must be in the range of greater than or equal to 2: 3 to less than or equal to 3: 2 lie to avoid in particular a warping (crowning) of the plastic plate with a layered structure after one or both sides. Conveniently, a thickness ratio in the range of 3: 4 to 4: 3, preferably in the range of 4: 5 to 5: 4, more preferably in the range of 9:10 to 10: 9, in particular 1: 1, is selected.

It is within the scope of the present Invention to the average thickness of the outer plates, wherein the differences in thickness along an outer panel are preferably maximum 10% based on the average thickness of the outer plate amount.

The method of the present invention can be alike for the Production of thick as well as of thin plastic plates with layered Construction can be used. However, it is particularly advantageous for the production of plastic sheets with a laminar structure with a total thickness in the range of 4 to 20 mm, preferably in the range of 8 to 15 mm, used.

Furthermore, the method according to the invention has for the Production of large format Plastic sheets with layered Construction, especially for Formats larger DIN A2, as very cheap proved. For this reason, preferably two outer plastic plates selected which each have a length of at least 2 m, preferably at least 3 m, in particular at least 4 m, and a width of at least two 2 m, preferably at least 3 m, in particular at least 4 m.

The process according to the invention available Plastic sheets with layered Construction is characterized in particular by their planarity. she fulfill preferably the requirements that the bulging of the plastic plates with layered Construction, measured according to a modified rule analogous to Standard EN ISO 12017, maximum 3 mm, preferably at most 2 mm, in particular of at most 1 mm, based on a length of 1 m.

The composition of the invention to be polymerized Acrylic resin can, in principle, in the context of the present invention chosen arbitrarily become. However, it has expediently the following components in the indicated quantities:

• A) a) (meth) acrylate 30-100% by weight a1) methyl (meth) acrylate 0-100% by weight a2) C ₂ -C ₄ (meth) acrylate 0-100% by weight a3) ≥ C ₅ (meth) acrylate 0-100% by weight a4) polyvalent (meth) acrylates 0-50% by weight b) comonomers 0-70% by weight b1) vinyl aromatics 0-35% by weight b2) vinyl ester 0-35% by weight, in each case based on the total weight of the acrylic resin composition and the components a1) to a4) are selected so that they give 30 to 100 wt .-% a) and the components b1) to b2) are selected so that they 0 to 70% by weight of b), while a) and b) together give advantageously 100% by weight of component A),
• B) to 1 part by weight of A) 0-12 Parts by weight of a soluble in A) or swellable polymer or prepolymer (syrup)
• C) initiator in an amount sufficient to cure the Component A)
• D) optionally means for adjusting the viscosity of the system,
• E) usual Additives in an amount of up to 3 parts by weight per 1 part by weight A).

As part of a very preferred embodiment The present invention is an acrylic resin consisting of the used above components A) to E).

The parenthesized components stand for their optional usability, d. H. (Meth) acrylate stands for acrylate and / or methacrylate.

The monomer component A) preferably contains at least 30% by weight of (meth) acrylate, monohydric (meth) acrylates having a C ₁ -C ₄ -ester residue being preferred. Longer-chain esters, ie those having a C ₅ or longer chain ester radical are expediently limited to 50% by weight in component A). Preferably, component A) contains at least 40% by weight of methyl methacrylate.

The long-chain (meth) acrylates make in the specified quantity the system is impact resistant. They are preferably used in amounts less than 50 wt .-%.

In addition to the (meth) acrylates, component A) may also contain other comonomers, the proportion of which is expediently restricted to 70% by weight. Among these comonomers, vinylaromatics and / or vinyl esters are preferably used in each case up to 35% by weight in component A). Higher levels of vinyl aromatic compounds are difficult to polymerize and can lead to a segregation of the Systems lead. Higher proportions of vinyl ester can continue to harden insufficiently at low temperatures and tend to a larger shrinkage behavior.

The component A) is preferably composed of 80-100% by weight and more preferably 90-100% by weight of (meth) acrylates, since with these monomers plastic sheets having a layered structure with processing methods that are favorable for application technology are used. and use properties can be achieved. The proportion of C ₂ -C ₄ esters in (meth) acrylates is preferably limited to 50% by weight in component A), these esters are preferably to max. 30 wt .-% and particularly advantageous to max. 20 wt .-% in component A).

Suitable monofunctional (meth) acrylates are in particular methyl methacrylate, butyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyltriglycol methacrylate, hydroxypropyl methacrylate.

Particularly suitable as comonomers Vinyl toluene, styrene, vinyl ester.

Preferably, styrene is max. 20% by weight in A), there a higher one Content to disorders during the polymerization can.

Component A) can also be polyvalent Contain (meth) acrylates in an amount of up to 50 wt .-%. Preferably are polyvalent (meth) acrylates in the (meth) acrylate system in the component A) in an amount of 0.1-30 % By weight especially appropriate in one Amount of 0.2-5 Wt .-%, contained. The polyfunctional (polyvalent) (meth) acrylates serve for polymer linking between linear molecules. Thereby can Properties like flexibility, Scratch resistance, glass transition temperature, melting point or hardening processes influenced become.

• (1) Difunktionelle (Meth)acrylate Verbindungen der allgemeinen Formel:
  
  worin R Wasserstoff oder Methyl ist und n eine positive ganze Zahl zwischen 3 und 20, wie z. B. Di(meth)acrylat des Propandiols, Butandiols, Hexandiols, Octandiols, Nonandiols, Decandiols und Eicosandiols, Verbindungen der allgemeinen Formel:
  
  worin R Wasserstoff oder Methyl ist und n eine positive ganze Zahl zwischen 1 und 14, wie z. B. Di(meth)acrylat des Ethylenglycols, Diethylenglycols, Triethylenglycols, Tetraethylenglycols, Dodecaethylenglycols, Tetradecaethylenglycols, Propylenglycols, Dipropylenglycols und Tetradecapropylenglycols; und Glycerindi(meth)acrylat, 2,2'-Bis[p-(γ-methacryloxy-β-hydroxypropoxy)-phenylpropan] oder Bis-GMA, Biphenol-A-dimethacrylat, Neopentylglycoldi(meth)acrylat, 2,2'-Di-(4-methacryloxypolyethoxyphenyl)propan mit 2 bis 10 Ethoxygruppen pro Molekül und 1,2-Bis(3-methacryloxy-2-hydroxypropoxy)butan.
• (2) Tri- oder mehrfachfunktionelle (Meth)acrylate Trimethylolpropantri(meth)acrylate und Pentaerythritoltetra(meth)acrylat.

Preferred polyfunctional (meth) acrylates include:

• (1) Difunctional (meth) acrylate compounds of the general formula:
  
  wherein R is hydrogen or methyl and n is a positive integer between 3 and 20, such as. As di (meth) acrylate of propanediol, butanediol, hexanediol, octanediol, nonanediol, decanediol and eicosanediols, compounds of the general formula:
  
  wherein R is hydrogen or methyl and n is a positive integer between 1 and 14, such as. Di (meth) acrylate of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dodecaethylene glycol, tetradecaethylene glycols, propylene glycols, dipropylene glycols and tetradecapropylene glycols; and glycerol di (meth) acrylate, 2,2'-bis [p- (γ-methacryloxy-β-hydroxypropoxy) phenylpropane] or bis-GMA, biphenol A dimethacrylate, neopentyl glycol di (meth) acrylate, 2,2'- Di (4-methacryloxypolyethoxyphenyl) propane having 2 to 10 ethoxy groups per molecule and 1,2-bis (3-methacryloxy-2-hydroxypropoxy) butane.
• (2) Tri- or polyfunctional (meth) acrylates trimethylolpropane tri (meth) acrylates and pentaerythritol tetra (meth) acrylate.

Preferred conventional polyfunctional (meth) acrylates include, among other triethylene glycol dimethacrylate (TEDMA), trimethylolpropane trimethacrylate (TRIM), 1,4-butanediol dimethacrylate (1,4-BDMA), ethylene glycol dimethacrylate (EDMA).

Component B) is an optional one Component, which is however very preferably used.

Basically you can in the deployment of B) proceed in two different ways. On the one hand you can use B) as a separately prepared polymeric substance and with the component A), wherein B) dissolves in A). To the another one can use the component A) and partially prepolymerize, to obtain a so-called prepolymer, which is also available as a syrup referred to as. This syrup then contains next to unchanged monomeric components from the group A) nor polymeric constituents from group B) in a mixture. For the preparation of the compositions according to the invention This syrup can either be used directly or with more Components of component A) are mixed.

The addition of the polymer B) or the Syrup to component A) can - as executed - for adjustment the viscosity of the resin and the overall rheology of the system as well as the better ones Curing done become.

Component B) may be any Be polymer. Especially useful is a Suspension polymer, emulsion polymer and / or grinding granules from recycling processes. The mean particle diameter of the polymer particles is then usually at <0, 8 mm.

Polymer B) is preferred to a copolymer, being hard and solubility by the type and amount of comonomer in the polymer B) influence. To deployable comonomers, which in the structure of the respective polymer B) are involved u. a. Acrylates and methacrylates derived from methyl methacrylate (MMA) vinyl ester, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene and the various halogen-substituted styrenes, vinyl and isopropenyl ethers, Dienes such as 1,3-butadiene and divinylbenzene.

Preferred comonomers are for methyl acrylate u. a., ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, 2-ethylhexyl methacrylate, propyl acrylate, propyl methacrylate, methacrylic acid, ethyl triglycol methacrylate, Hydroxypropyl methacrylate.

This polymer B) should be soluble in A) or be swellable. This depends the solubility of B) as well as the speed of the dissolution process naturally from the molecular weight of component B). As a guideline, polymers B) with lower molecular weights faster and in larger proportions in component A), as with components B) with molecular weights at the top the specified range is the case. To 100 parts by weight A) 0.1 to 75 parts by weight of the polymer B) are used, preferably 0.5 to 25 parts by weight B) and particularly preferably 1 to 10 parts by weight B).

Suitable as component B) are in particular Poly (meth) acrylates. Furthermore, polyvinyl chloride, polyvinyl acetate, Polystyrene, epoxy resins, epoxy (meth) acrylates, unsaturated polyesters, Polyurethanes or mixtures thereof. These polymers cause z. B. special flexibility properties, Shrink regulation, act as a stabilizer or leveling agent.

The molecular weight (weight average Mw) of the polymer B) is usually between 50,000 g / mol and 10 million g / mol, preferably between 100,000 g / mol and 5 million g / mol, or more preferably between 150,000 g / mol and 1 million g / mol. The determination of the molecular weight can for example, by the method of determination known to those skilled in the art Size Exclusion Chromatography (SEC) using the usual Standards, e.g. As polystyrene, take place.

If as component B) a syrup this may be used alone or in admixture with others Proportions of component A) are used. This usually occurs no problems in terms of the rate of release or that Mixing behavior of the components, which is advantageous. On one Weight part A) 0 to 12 parts of the syrup 8) are used. Preference is given to 2 to 11 parts by weight B) to 1 part by weight of A) used. Especially useful 4 to 10 parts by weight B) to 1 part by weight of A). Most notably It is preferable to take 6 to 9 parts by weight of a syrup and mix with one part by weight of polymerizable monomers A).

Preferably, as a component B) Syrup used and dissolved in A).

Component C) is an essential one Component used for curing (Polymerization) of the polymerizable system is essential.

The polymerization can be free-radical as well as ionic, the radical polymerization being preferred is. It can take place thermally, by blasting and by initiators, preferably using initiators which form radicals. The particular conditions of the polymerization depend on the monomers selected and the initiator system, and are well known in the art.

Among the preferred initiators include Others well-known in the art Azoinitiatoren how AIBN or 1,1-azobiscyclohexanecarbonitrile, and peroxy compounds, such as methyl ethyl ketone peroxide, acetylacetone peroxide, Ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane, tert-butyl peroxy-2-ethylhexanoate, tert-butylperoxy-3,5,5-trimethylhexanoate, 1,1-bis (tert-butylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, cumyl hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, bis (4-tert-butylcyclohexyl) peroxydicarbonate, Mixtures of two or more of the aforementioned compounds with each other and mixtures of the aforementioned compounds with those not mentioned Compounds that can also form radicals.

There are also redox systems in question, whereby phlegmatized systems in organic solvents or in aqueous solutions or in aqueous suspension are known and used. Such a system is available under the trademark ^® Cadox from Akzo.

Also mixtures of several initiators with graded half-life are possible. That way you can master the polymerization reaction better, local irregularities can be avoided and it will get a smoother result. Also, one can thereby shorten the Nachpolymerisationszeit (annealing in thermo cabinets).

The amount of component C) is variable within wide limits. It depends on the composition of the monomers, the type and amount of the polymer or prepolymer and the desired polymerization temperature and the desired molecular weight of the polymer to be prepared. benchmarks For example, for molecular weights of 10,000 to 200,000 (weight average molecular weight), from 2 × 10 ^-5 to about 1 × 10 ^-4 mole of initiator per mole of polymerizable components of the monomer system. Depending on the molecular weight of the initiator compound (s) used, about 1 × 10 ^-3 to 5 × 10 ^{-5 parts by} weight of component C) are suitable per part by weight of component A). By correspondingly lower choice of the amount of initiator, the molecular weight of the polymerized intermediate layer can be up to 10 million g / mol.

The component D) is is an optional component of the polymerizable (meth) acrylate system, however, preferably contained in the system. examples are Emulsifiers. Preference is given to lecithins, z. B. soy lecithin. The amount The substances to be used can be varied over a wide range become. Preference is given to 0.01 to 1 part by weight of D) to 1 part by weight A). Particularly useful are 0.1 to 0.2 part by weight of D) to 1 part by weight of A).

Component E) is optional. It this is the usual Additives that are known per se. So this includes u. a. Color pigments, antistatic agents, antioxidants, flame retardants, Lubricants, dyes, flow improvers, fillers, Light stabilizers and organic phosphorus compounds, such as phosphites or phosphonates, pigments, thixotropic agents, UV protectants, Weathering agents and plasticizers.

In the context of the present invention the amount of acrylic resin is chosen such that by the polymerization an acrylic glass intermediate layer with a thickness of at least 2 mm is generated. Particularly advantageous thicknesses of the intermediate layer are in the range of 2 mm to 10 mm, in particular in the range of 3 mm to 9 mm. This is generally a thicker intermediate layer better able to detect any irregularities in the thickness of the outer plastic sheets compensate.

According to the invention, the composition the acrylic resin is further preferably selected such that the resulting acrylic glass intermediate layer is one of at least an outer plastic plates different Color has. Within the scope of a most preferred embodiment In the present invention, the acrylic glass intermediate layer is colorless.

• a) die zwei äußeren Kunststoff-Platten mit Hilfe einer Dichtung so distanziert, dass zwischen den beiden Platten ein Spalt von mindestens 2 mm entsteht,
• b) in diesen Spalt durch eine Öffnung in der Dichtung die Acrylharz-Zusammensetzung einfüllt und
• c) die Polymerisation der Acrylharz-Zusammensetzung initiiert.

Carrying out the chamber polymerization can be carried out in a manner known per se for the purposes of the present invention, except for the fact that two plastic sheets are used instead of the otherwise customary glass sheets. Appropriately, one proceeds in such a way that one

• a) the two outer plastic plates with the aid of a seal so distanced that between the two plates, a gap of at least 2 mm,
• b) in this gap through an opening in the gasket, the acrylic resin composition fills and
• c) initiating the polymerization of the acrylic resin composition.

In this context, it has as very cheap proved to place the chamber horizontally and to polymerize. This is the lower outer plastic plate expediently on a glass sheet with a thickness of preferably at least 10 mm in order to a bulge The best way to prevent the lower plastic plate. Farther It may also be beneficial to have a second glass on top of the chamber with a thickness of preferably at least 10 mm to put the Chamber further stabilize.

For more details will be on the standard Reference literature referred, for example, to M. Stickler et al. in "Polymethacrylates", Ullmann's Encyclopedia of Industrial Chemistry, Vol. A 21, VCH Publishers Inc., Weinheim, 1992, page 473 ff or W. Wunderlich in Houben-Weyl, Methods of Organic Chemistry, Volume E 20 "Macromolecular Substances ", G. Thieme Verlag, Stuttgart, 1987, Volume 2, page 1145 ff, the disclosure of which hereby is explicitly referred to.

Possible Areas of application of the obtainable by the process according to the invention Plastic sheets with layered Construction are for immediately obvious to the person skilled in the art. They are particularly suitable for such Applications for multilayered, colored Plastic plates with a layered structure are predetermined. These include especially the visual advertising, the furniture industry, for example for delusions, as well as the shop and fair construction.

The following is the present Invention by examples and comparative examples explained in more detail, without this is a limitation the idea of the invention is to take place.

I. General experimental procedure

A) Chamber construction

The description of the chamber structure done from bottom to top.

The bottom plate, to support the overall package, is a 10 mm thick glass pane (float glass). It is used to protect the underside of the package from damage (eg rack prints, etc.). On top of this lies the colored PLEXIGLAS ^® plate, which on the underside is covered with SH foil (= self-adhesive Sheeting) is covered. The film is used to obtain a visually perfect surface in the later annealing process. In this case, the film has a corresponding temperature resistance. The top of the colored plate is unknown.

On the colored plate is the Sealing cord (round profile, PVC or PE) fixed.

In addition, the for filling the Chamber needed filling hose (Gut-like Material with low wall thickness) inserted.

Thereafter, the cover is covered with a clear PLEXIGLAS ^® pane. This is covered only on the top again with SH foil.

As a lid, a 10 mm glass pane to stabilize the overall package. Without use Of the lid, it may happen that the colorless disc strong Bends, which leads to tolerance problems.

B) filling the chamber, intermediate layer

The package described under A) becomes Clamped on three sides with elastic spring steel clips. The unclamped front is wedged on (about 30 mm). About the resulting opening, will over the previously inserted filling hose the tilted one Chamber filled with syrup. This will start the syrup into the chamber from the bottom up filled, to avoid filling bubbles in the syrup and with the PLEXIGLAS slices in the upper area Be wetted syrup.

It will be exactly the one for the desired layer thickness required amount filled. The Fülldarm is at filling pulled out again.

After that, the front will be the same Spring steel clips closed. The entire package then becomes horizontal placed and vented. For the further process steps, it is retracted into a polymerization rack.

C) solution production

A low molecular weight, UV protected Syrup, with about 25% polymer content. The initiator is a combination used from high and low decomposition peroxides. The solution will be before filling evacuated.

D) polymerization

The polymerization takes place in a water bath, depending on the strength the intermediate layer, in the temperature range of 30 to 55 ° C. The length of stay Depending on the layer thickness between 1.5 (3 mm) and 15 (10 mm) hours. The turnover thus achieved is approx. 90%.

When using PE cord, this is removed in the course of polymerization, this will be the brackets decreased.

When using PVC cord the cord remains in the intermediate area and the clips on the Package.

E) final polymerization

The complete package will be in the tempering cabinet retracted.

The final polymerization takes place in Tempering cabinet at approx. 100 ° C, between 4 to 10 hours. The turnover is then greater than 99%.

F) Disassembly

After the cooling down phase, the brackets become removed (PVC cord). For dismantling, the upper glass pane lifted. The polymerized, both sides with SH film pasted Package will follow lifted from the bottom plate and on a transport pallet discontinued.

G) control

For control, the top sheet deducted and the plate checked for errors and tolerance. Finally done again the application of a protective lamination. The bi-color plate can now be cropped.

The procedure described above can be applied mutatis mutandis to the Rostero chamber method (eg. DE-OS 20 40 849 , Polymerization in vertical arrangement of the chambers) or the air polymerization be transmitted.

II. Measuring instructions for Determination of the deflection

The determination of the deflection of the plates (planarity) is carried out according to a modified form of the German standard 12017 EN ISO as follows:
Test conditions, sampling, sample preparation, etc. are carried out as described in the standard, with the difference that, instead of the web plates described in the standard, the flat, monolithic plates of the present application are examined.

The measurement of the deflection takes place in the vertical position of the plates, as in point 6.6 "Deflection the disk surface " becomes a square piece of 1 m × 1 m edge length cut out of the plate to be measured and on both sides Remove the protective foil (SH foil) on a level, horizontal surface posed. By repeatedly applying the long, straight ruler (length 1000 mm) to different places of the concavely curved surface the maximum distance between the plate surface and the ruler is determined (e.g., calipers or depth gauge). After seeing the plates of the present application no extrusion direction, only the Value of the maximum deflection specified, regardless of whether it is horizontal or was determined with vertical attitude of the ruler, and it becomes when specifying the value with specified that the value is a length of 1 m is related.

example 1

According to the general test procedure An acrylic glass plate in the format 3.15 m × 2.13 m (glass format) was produced. It became a lower outer, colored Acrylic sheet with a thickness of 3 mm and an upper outer, colorless Acrylic glass panel used with a thickness of 3 mm. The thickness of the Interlayer was set to 3 mm.

The resulting acrylic sheet with a layered structure has the same properties and processability as PLEXIGLAS ^® GS from Röhm GmbH & Co. KG, z. Also, it is characterized by a high planarity and shows a bulge, measured according to the modified rule analogous to the standard EN ISO 12017, of less than 3 mm in relation to a length of 1 m.

Example 2

According to the general test procedure An acrylic glass plate in the format 2.25 m × 1.45 m (glass format) was produced. It became a lower outer, colored Acrylic sheet with a thickness of 4 mm and an upper outer, colorless Acrylic glass plate used with a thickness of 4 mm. The thickness of the Interlayer was set to 6 mm.

The acrylic glass plate obtained has the same properties and processability as PLEXIGLAS ^® GS Fa. Röhm GmbH & Co. KG, for example, transparency, laser cuttability, workability, adhesiveness, etc. Also, it is characterized by high planarity and shows a dishing, measured in accordance with the modified standard analogous to standard EN ISO 12017, of less than 3 mm in relation to a length of 1 m.

Comparative Example 1

According to the general test procedure An acrylic glass plate in the format 2.25 m × 1.45 m (glass format) was produced. It became a lower outer, colored Acrylic sheet with a thickness of 3 mm and an upper outer, colorless Acrylic sheet used with a thickness of 4 mm. The fat the intermediate layer was adjusted to 6 mm.

The resulting acrylic sheet with layered Structure shows a bulge, measured according to the modified standard analogous to the standard EN ISO 12017, from about 3 mm relative to a length of 1 m.

Comparative Example 2

According to the general test procedure An acrylic glass plate in the format 2.25 m × 1.45 m (glass format) was produced. It became a lower outer, colored Acrylic sheet with a thickness of 4 mm and an upper outer, colorless Acrylic sheet used with a thickness of 5 mm. The fat the interlayer was set to 6 now.

The resulting acrylic sheet with layered Structure shows a bulge, measured according to the modified standard analogous to the standard EN ISO 12017, from about 3 mm relative to a length of 1 m.

Comparative Example 3

According to the general test procedure but without the upper outer acrylic sheet was an acrylic sheet with a layered structure in 2.25 format m × 1.45 m (glass format) produced. However, this package had to be discarded be because the bulge the thus obtained plate with about 6-9 mm based on a length of 1 m, measured according to the modified standard analogous to the standard EN ISO 12017, way too high.

Claims (12)

A process for producing a plastic sheet having a laminar structure, in which an acrylic resin is polymerized in the chamber process between two outer plastic sheets, characterized in that the thickness ratio of the two outer plastic sheets in the range of greater than or equal to 2: 3 to smaller or equal to 3: 2, and by the polymerization produces an acrylic glass intermediate layer having a thickness of at least 2 mm. Method according to claim 1, characterized in that that you have two outer plastic plates which each independently each other have a thickness in the range of 1 to 7 mm. Method according to claim 1 and / or 2, characterized that you have a plastic plate with a layered structure with a total thickness in the range of 4 to 20 mm. Method according to one of the preceding claims, characterized characterized in that at least one of the outer plastic plates an acrylic (co) polymer, ABS, cycloolefinic copolymer (COC), Nylon, polyether, polyester, polycarbonate, polystyrene or PVC consists. Method according to one of the preceding claims, characterized characterized in that at least one of the outer plastic plates a mineral filler or contains a functional additive. Method according to at least one of the preceding Claims, characterized in that one uses two outer plastic plates, which each have a length of at least 2 m and a width of at least two 2 m. Method according to at least one of the preceding Claims, characterized in that a plastic plate with a layered structure produces a deflection, measured according to a modified Regulation analogous to the standard EN ISO 12017, of a maximum of 3 mm with respect to one length of 1 m. Method according to at least one of the preceding Claims, characterized in that at least one colored, outer plastic plate starts. Method according to at least one of the preceding Claims, characterized in that the acrylic resin composition is such selects the resulting acrylic glass intermediate layer is one of at least an outer plastic plate has different color. Method according to at least one of the preceding Claims, characterized in that as outer plastic plates such Uses plates obtained by a casting process. Method according to at least one of the preceding claims, characterized in that one uses an acrylic resin which contains the following components: A) a) (meth) acrylate 30-100% by weight a1) methyl (meth) acrylate 0-100% by weight a2) C ₂ -C ₄ (meth) acrylate 0-100% by weight a3) C ₅ (meth) acrylate 0-100% by weight a4) polyvalent (meth) acrylates 0-50% by weight b) comonomers 0-70% by weight b1) vinyl aromatics 0-35% by weight b2) vinyl ester 0-35% by weight, in each case based on the total weight of the acrylic resin composition and the components a1) to a4) are selected so that they give 30 to 100 wt .-% a) and the components b1) to b2) are selected so that they 0 to 70% by weight of b), while a) and b) together give 100% by weight of component A), B) to 1 part by weight of A) 0-12 parts by weight of a) soluble or swellable in A) Polymer or prepolymer (syrup) C) initiator in an amount sufficient to cure the component A) D) optionally means for adjusting the viscosity of the system, E) conventional additives in an amount of up to 3 parts by weight per 1 part by weight of A). Method according to at least one of the preceding Claims, characterized in that one a) the two outer plastic plates with the help of a seal so distant that between the two Plates creates a gap of at least 2 mm, b) in these Gap through an opening in the seal the acrylic resin composition fills and c) initiating the polymerization of the acrylic resin composition.