HK1085694B - Infrared-reflective, transparent, multi-layer plastic laminates - Google Patents

Description

Infrared reflective, transparent, multi-layer plastic laminate

The invention relates to a multilayer product made of a plastic exhibiting high infrared reflection and high gloss.

Multilayer products having layers comprising transparent thermoplastic plastic are known.

In particular, polycarbonate sheets are known. They are manufactured for many purposes of use. Their production is, for example, carried out by coextrusion of the polycarbonate-containing compositions (molding compositions) optionally together with molding compositions having a high UV absorber content.

Polycarbonate sheets are known from EP-A0110221.

In order to prevent the polycarbonate sheets from yellowing over a long period of time due to UV light, it has been proposed in EP-A0320632 to provide the sheets with a coextruded layer containing a high concentration of a sparingly volatile UV absorber.

EP-B0678376 and EP-B0595413 propose that, for sheets made of polyester, in particular comprising copolyester sheets consisting of a mixture of an aromatic dicarboxylic acid and two aliphatic diols, such as PETG, the weathering resistance is achieved by coextrusion with an outer layer containing a high concentration of UV absorber, such as those based on benzotriazoles.

From german patent specification DE-C2544245, a plate made of polymethyl methacrylate is known, which contains a light-reflecting particle material positioned parallel to the surface. The layer thickness is designed such that visible light is substantially transmitted and infrared radiation is substantially reflected.

This known body contains light-reflecting particles which are contained in a matrix made of polymethyl methacrylate. These fine particles were added to a liquid methyl methacrylate monomer, and the liquid methyl methacrylate monomer was introduced into a polymerization chamber formed by parallel glass plates and partially polymerized. Before this, the particles have fallen onto the underlying glass sheet. The particles are positioned parallel to the surface by parallel displacement of the sheet and remain in that position as polymerization continues. This production method is therefore complicated and expensive in terms of processing steps.

EP-a 340313 describes some solar radiation coatings for ships, tanks, buildings, etc. for reducing solar heat. These coatings contain a binder and a heat reflective pigment, and optionally any desired color pigments.

According to EP-A428937, polyethylene pipe sections for greenhouses are constructed by brushing or spraying a coating containing light-reflecting pigments in a lacquer film binder carrier matrix. Since these pigment particles are not oriented by the coating process, they only act as a toning effect, so that the transmission is unsatisfactory, and since the customary lacquer adhesive carriers have a weak adhesion to polyethylene, the coating is easily washed off by water streams from the coated pipe sections.

EP-A0548822 describes PMMA plates and polycarbonate plates which contain special pearlescent pigments in the coextruded layers. These pearlescent pigments are composed of a support material, such as mica, which is covered with a layer of titanium dioxide having a thickness of from 60 to 120 nm.

The production of these pearlescent pigments is described, for example, in DE-A19618569. EP-A0548822 proposes that the selectivity parameter (SKZ) must be above 1.15 in order to obtain sufficient IR reflection. SKZ is defined as follows.

The T/g ratio is also referred to as the selectivity parameter SKZ (in accordance with DIN 67507). This ratio is the quotient of the percentage of light transmission in the visible region of the spectrum and the percentage of the total transmission of radiant energy. SKZ is a measure of IR reflection and in this respect also of the effectiveness of the solar control glazing; therefore, it should be as high as possible.

It is known that, in order to achieve the desired high selectivity parameters, the panels described in EP-A0548822 have pearlescent pigments in the coextruded layer in an amount of from 20 to 40% by weight. But has the disadvantage that it is necessary to use a pearlescent pigment content as high as this. Therefore, these sheets are very expensive.

DE-A10006651 proposes pearlescent pigments comprising three or more titanium dioxide and silicon dioxide layers on mica, which have a particularly low degree of yellowing as a result of weathering during weathering of plastics containing these pigments.

Pearlescent pigments have the disadvantage that they form a rough surface when applied to the outer layers of a multilayer product. In addition, the content of the pearlescent pigment must be high.

It is therefore an object of the present invention to provide IR-reflecting products which have a selectivity parameter (SKZ) of greater than 1.15, a high surface gloss and which can achieve these properties with as little pearlescent pigment as possible.

This object is achieved by a multilayer product comprising three layers A, B and C, in which layer A comprises a transparent thermoplastic, layer B comprises a transparent thermoplastic and a pigment composed of a transparent support material and a titanium dioxide layer having a layer thickness of 150 and 200 nm on the support material, and layer C comprises a transparent thermoplastic, and further layers can be applied to the titanium dioxide layer. The invention relates to such a multilayer product.

The pigment concentration can be optimized by routine experimentation by one skilled in the art. The concentration is chosen such that SKZ is greater than 1.15. This concentration of course also depends on the thickness of the B layer.

If further layers are to be applied on top of the titanium dioxide layer, these layers must be selected so as not to prevent the SKZ from reaching above 1.15.

A particular embodiment of the invention is said multilayer product wherein the B layer is 15 to 250 microns thick.

Another embodiment of the invention is the multilayer product wherein the transparent thermoplastic contained in layer A, B and layer C is selected from the group consisting of polycarbonate, polymethyl methacrylate, modified polymethyl methacrylate (PMMA) (copolymer of methyl methacrylate and butyl methacrylate or butyl acrylate or other common comonomers), transparent ABS, polystyrene, styrene-acrylonitrile copolymer, transparent polyvinyl chloride and polyesters, especially those comprising repeating units derived from ethylene glycol and/or cyclohexane-dimethanol and/or butanediol and terephthalic acid and/or isophthalic acid and mixtures thereof.

Another embodiment of the present invention is the multilayer product wherein the transparent thermoplastic of at least one of layer A, B and layer C is a copolyester derived from a dicarboxylic acid and a diol, wherein the dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, and cyclohexane-1, 4-dicarboxylic acid, wherein the diol is selected from the group consisting of ethylene glycol, cyclohexane-dimethanol, and diethylene glycol, and wherein the content of repeat units derived from diethylene glycol is less than 5 mole% of the content of all repeat units derived from diol.

Cyclohexane-dimethanol has the following structure:

another particular embodiment of the invention is said multilayer product wherein the layer B is located between the layers a and C.

Another particular embodiment of the invention is that the multilayer product is selected from the group consisting of a sheet, a solid sheet, a corrugated sheet and a multilayer sheet.

The invention also relates to the use of the multilayer product according to the invention for producing decorative panels for wall coverings, partitions, ceiling coverings, auxiliary floors, greenhouse panes, bus stop panes, roofs, panes for attenuating incident light, or alternative coatings and for thermal insulation.

The invention also relates to products containing the multilayer product according to the invention.

The product is preferably selected from the group consisting of wall coverings, partitions, ceiling coverings, auxiliary floors, greenhouse glass, bus stop glass, roofs, incident light attenuating glass, and paint replacement products.

In addition to the A, B and C layers, the multilayer product according to the invention may also contain further layers. The order of these layers is arbitrary. The B layer is preferably located between the a and C layers. A. Other preferred sequences of layers B and C are as follows: C-B-A-C, C-B-A-B-C or C-B-A-B.

A. The B and C layers may each be composed of different plastics. If the same type of multilayer (e.g., in C-B-A-B-C) is used, the same type of layer (in this example, two layers B and two layers C) may comprise different compositions.

The pigments according to the invention consist of a transparent support material coated with a titanium dioxide layer having a thickness of 150-200 nm. Such pigments are known and commercially available. Platelet-shaped pigments having a diameter of 1 to 80 μm and a thickness of 0.4 to 2.0. mu.m are preferred.

The transparent carrier material is mica, other layered silicate, glass flake, PbCO₃xPb(OH)₂BiOCl, or flaked sheet-like dioxide produced by the process described in WO 93/108237Silicon.

The multilayer products according to the invention have the advantage of a selectivity parameter of above 1.15 and a high surface gloss (preferably > 40%, particularly preferably > 70%). At the same time, only small amounts of the pigments according to the invention are required.

The multilayer product according to the invention can be used as insulating glass.

The B layer of the multilayer product according to the invention is preferably from 15 to 250 microns thick, in particular from 20 to 150 microns thick, most preferably from 25 to 70 microns thick.

The C layer of the multilayer product according to the invention is preferably 5 to 1000 μm thick.

The transparent thermoplastic contained in layers A, B and C of the multilayer product according to the invention is preferably selected from: polycarbonates, polymethyl methacrylate, modified polymethyl methacrylate (PMMA) (copolymers of methyl methacrylate and butyl methacrylate or butyl acrylate or other customary comonomers), transparent ABS, polystyrene, styrene acrylonitrile copolymers, transparent polyvinyl chloride and polyesters, in particular those having repeating units derived from ethylene glycol and/or cyclohexane-dimethanol and/or butanediol and terephthalic acid and/or isophthalic acid and/or cyclohexane-1, 4-dicarboxylic acid and mixtures thereof.

The transparent thermoplastic contained in the A, B and C layers of the multilayer product according to the invention may also be a polyester as disclosed in US-A5986040. It may also be a plastic composition as disclosed in WO 99/63002, or it may also be a plastic as disclosed in WO 00/69945.

Polycarbonates are particularly preferred, in particular homopolycarbonates based on bisphenol A.

In order to increase the weathering behavior of the multilayer products according to the invention, UV absorbers may be present in both the uppermost layer and the intermediate layer. The UV absorber may be present in different amounts in different layers.

The multilayer products according to the invention can be produced by coextrusion, melt lamination, coating films or lamination. Coextrusion is preferred.

The layer C of the multilayer product according to the invention may additionally contain UV absorbers, heat stabilizers, optical brighteners, colorants and other additives.

The layer C may additionally contain 0 to 5% by weight of the pigment contained in the layer B.

A. The B and C layers, independently of one another, may additionally contain UV absorbers, heat stabilizers, optical brighteners, colorants and other additives.

In particular, the multilayer products according to the invention can be solid plastic sheets, corrugated sheets and multilayer sheets (e.g. double-layer sheets, triple-layer sheets, corrugated multilayer sheets). These panels also include those having an additional top layer of the molding composition having a high UV absorber content on one or both sides.

The multilayer product according to the invention has a pearlescent surface. They can therefore be used as decorative panels for wall coverings, partitions, ceiling coverings, auxiliary floors, glass and roofs which attenuate incident light, for modern interior design, for the decoration of buildings for optical applications, or for replacing lacquers and for thermal insulation.

It is possible to carry out subsequent treatments, such as thermoforming, or surface treatments, such as the application of scratch-resistant paint films, water-spread cloth layers, etc., on the multilayer products according to the invention, and the invention also relates to the products produced by these processes.

The thermoplastic aromatic polycarbonates used for the coextrusion molding compositions according to the invention or for coating the moldings are those which have also been used for this purpose in the past. These are homopolycarbonates, copolycarbonates and thermoplastic polyester carbonates. The average molecular weight Mw is determined by measuring the relative solution viscosity in methylene chloride or in a mixture of equal weights of phenol and o-dichlorobenzene at 25 ℃ and calibrating by light scattering, and is 18000-40000, preferably 20000-36000, in particular 22000-35000.

With regard to the production of polycarbonates for the coextrusion molding compositions according to the invention, reference may be made, for example, to the following references: "polycarbonate chemistry and Physics" by "Schnell" as published in "Polymer compendium (Polymer Reviews), volume 9, Interscience Publishers, New York, London, Sydney 1964"; PREVORSEK, B.T.DEBONA and Y.KESTEN, corporation Research Center, Allied Chemical

"Synthesis of Poly (ester) carbonate copolymer" published in "Journal of Polymer Science, Polymer chemistry edition", volume 19, 75-90(1980), by Moristown Corporation, New Jersey 07960: freutag, U.G. 0, P.R. Muller, N.Nouvertne, BAYER AG in "Encyclopedia of Polymer Science and engineering (Encyclopedia of Polymer Science and engineering)" Vol 11, second edition, 1988, page 648-718 "polycarbonate" section; and finally "polycarbonates, polyacetals, polyesters, cellulose esters" by Ph.U.G.Kircher and P.R.Muller et al in "Becker/Braun, Kunststoff-Handbuch", Vol. 3/1, Carl Hanser Verlag Munich, Wien, 1992, pp. 117-. The preparation is preferably carried out by the phase interface process or the melt transesterification process, as described in the phase interface process.

Preferred compounds to be used as starting compounds are bisphenols of the general formula

HO-Z-OH

Wherein Z is a divalent organic group having 6 to 30 carbon atoms, which group contains one or more aryl groups. Examples of such compounds are bisphenols selected from the following compounds: dihydroxybiphenyl, bis (hydroxyphenyl) alkanes, indanbisphenol, bis (hydroxyphenyl) ether, bis (hydroxyphenyl) sulfone, bis (hydroxyphenyl) methanone, and α, α' -bis (hydroxyphenyl) diisopropylbenzene.

Particularly preferred bisphenols are selected from the following compounds mentioned above: bisphenol A, tetraalkylbisphenol A, 4- (M-phenylenediisopropyl) diphenol (bisphenol M), 4- (p-phenylenediisopropyl) -diphenol, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane (BP-TMC) and optionally mixtures thereof. Homopolycarbonates based on bisphenol A and copolycarbonates based on the monomers bisphenol A and 1, 1-bis (4-hydroxy-phenyl) -3, 3, 5-trimethylcyclohexane are particularly preferred. The bisphenol compounds used according to the invention are reacted with carbonic acid, in particular phosgene, or, in the case of transesterification by melt reaction, diphenyl carbonate or dimethyl carbonate.

The polyester carbonates are obtained by reacting the bisphenols already mentioned above, at least one aromatic dicarboxylic acid and optionally carbonic acid equivalents. Suitable aromatic dicarboxylic acids are, for example, phthalic acid, terephthalic acid, isophthalic acid, 3 '-or 4, 4' -biphenyldicarboxylic acid and benzophenonedicarboxylic acid. In the polycarbonates, a portion, up to 80 mol%, preferably from 20 to 50 mol%, of the carbonate groups may be replaced by aromatic dicarboxylic acid ester groups.

The inert organic solvent used in the interfacial polycondensation method is, for example, dichloromethane, various dichloroethane and chloropropane compounds, tetrachloromethane, trichloromethane, chlorobenzene and chlorotoluene, with chlorobenzene, dichloromethane or mixtures of dichloromethane and chlorobenzene being preferably used.

The phase interface reaction can be accelerated by catalysts, such as tertiary amines, in particular N-alkylpiperidines or onium salts. Tributylamine, triethylamine and N-ethylpiperidine are preferably used. In the case of the melt transesterification process, the catalysts mentioned in DE-A4238123 are used.

The polycarbonates may be branched deliberately and controllably by adding small amounts of branching agents. Some suitable branching agents are phloroglucinol, 4, 6-dimethyl-2, 4, 6-tris- (4-hydroxyphenyl) heptene-2; 4, 6-dimethyl-2, 4, 6-tris- (4-hydroxyphenyl) heptane; 1, 3, 5-tris- (4-hydroxyphenyl) benzene; 1, 1, 1-tris- (4-hydroxyphenyl) ethane; tris- (4-hydroxyphenyl) phenylmethane, 2-bis- [4, 4-bis (4-hydroxyphenyl) cyclohexyl ] propane; 2, 4-bis- (4-hydroxyphenylisopropyl) phenol; 2, 6-bis- (2-hydroxy-5' -methylbenzyl) -4-methylphenol; 2- (4-hydroxyphenyl) -2- (2, 4-dihydroxyphenyl) propane; hexa- (4- (4-hydroxyphenylisopropyl) phenyl) o-terephthalate; tetrakis- (4-hydroxyphenyl) methane; tetrakis- (4- (4-hydroxyphenylisopropyl) -phenoxy) methane; α, α' α "-tris- (4-hydroxyphenyl) -1, 3, 5-triisopropylbenzene; 2, 4-dihydroxybenzoic acid; 1, 3, 5-trimellitic acid; cyanuric chloride; 3, 3-bis- (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-indoline; 1, 4-bis- (4 ', 4' -dihydroxytriphenyl) methyl) -benzene, in particular 1, 1, 1-tris- (4-hydroxyphenyl) ethane and bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-indoline.

0.05 to 2 mol%, based on the amount of diphenols used, of branching agents or mixtures of branching agents which may optionally be added, may be added together with the diphenols or at a later stage of the synthesis.

Phenols, such as phenol, alkylphenols, such as cresol and 4-tert-butylphenol, chlorophenol, bromophenol, cumylphenol or mixtures thereof are preferably used as chain terminators in amounts of from 1 to 20 mol%, preferably from 2 to 10 mol%, per mole of bisphenol. Phenol, 4-tert-butylphenol and cumylphenol are preferred.

Chain terminators and branching agents may be added separately to the synthesis or together with the bisphenols.

A process for preparing polycarbonates for the coextrusion molding compositions according to the invention by the melt transesterification process is described, for example, in DE 4238123.

The UV absorber is added to the thermoplastic coextrusion molding composition according to the invention applied by conventional methods, for example by mixing a solution of the UV absorber with a solution of the plastic in a suitable organic solvent, for example CH₂Cl₂Halogenated paraffins, halogenated aromatics, chlorobenzene and xylenes. The mixture of these substances is then homogenized by extrusion in a known manner; the solution mixture is preferably discharged in a known manner by evaporating off the solvent and then extruding, for example by mixing.

Examples of suitable stabilizers for the polycarbonates of the coextrusion molding compositions according to the invention include phosphines, phosphites, epoxides or siliceous stabilizers, and also the other compounds described in EP 0500496A1 and U.S. Pat. No. 3, 3,673,146. Examples thereof include triphenylphosphine, diphenylalkylphosphite, phenyldialkylphosphite, tris (nonylphenyl) phosphite, tetrakis (2, 4-di-tert-butylphenyl) -4, 4' -biphenylene diphosphonate (diphosphonite), and triarylphosphite. Triphenylphosphine and tris (2, 4-di-tert-butylphenyl) phosphite are particularly preferred.

The coextrusion molding compositions according to the invention can be used for coextrusion sheets. It is possible to have a co-extruded layer on one or both sides of the sheets.

Coextrusion as such is known from the literature (see, for example, EP 110221 and EP 110238).

Suitable UV absorbers for the optionally used coextrusion compositions are those compounds which, owing to their absorption capacity below 400 nm, are effective in protecting polycarbonates from UV light and have a molecular weight above 370, preferably 500 or above.

Particularly suitable UV absorbers are the compounds of the formula (II) described in WO 99/05205:

wherein

R¹And R²Are the same or different and denote

H. Halogen, C₁-C₁₀Alkyl radical, C₅-C₁₀Cycloalkyl radical, C₇-C₁₃Aralkyl radical, C₆-C₁₄Aryl, -OR⁵Or- (CO) -O-R⁵Where R is⁵H or C₁-C₄-an alkyl group,

R³and R⁴Likewise identical or different and denoted H, C₁-C₄Alkyl radical, C₅-C₆Cycloalkyl, benzyl or C₆-C₁₄An aryl group, a heteroaryl group,

m is 1, 2 or 3 and n is 1, 2, 3 or 4,

and those of formula (III).

Wherein the bridge represents

Wherein R is¹And R²M, n have the meanings given for formula (II),

in addition, wherein p is an integer of 0 to 3,

q is an integer of 1 to 10,

y is-CH₂-CH₂-、-(CH₂)₃-、-(CH₂)₄-、-(CH₂)₅-、-(CH₂)₆-, or CH (CH)₃)-CH₂-

And

R³and R⁴Have the meanings given for formula (II).

Other suitable UV absorbers are substituted triazines, such as 2, 4-bis- (2, 4-dimethylphenyl) -6- (2-hydroxy-4-n-octyloxyphenyl) -1, 3, 5-triazine (R: (R) (R))UV-1164) or 2- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) -5- (hexyl) oxy-phenol (1577). Particularly preferred as UV absorbers are those under the trade name360 or AdekaLA 31 commercially available 2, 2-methylenebis- (4- (1, 1, 3, 3-tetramethylbutyl) -6- (2H-benzyltriazol-2-yl) phenol). UV absorbers as exemplified in EP 0500496A1 are also suitable. The UV absorber obtained in example 1 of WO 96/15102, Uvinul 3030 from BASF AG, can also be used.

Examples of antistatic agents are cationic compounds, such as quaternary ammonium salts, phosphonium salts or sulfonium salts, anionic compounds, such as alkylsulfonates, alkyl sulfates, alkyl phosphates, carboxylates in the form of alkali metal or alkaline earth metal salts, nonionic compounds, such as polyethylene glycol esters, polyethylene glycol ethers, fatty acid esters, ethoxylated fatty amines. Preferred antistatic agents are nonionic compounds.

Preferred fillers are glass fibers, micaceous stone, silicates, quartz, talc, titanium dioxide or wollastonite. Preferred reinforcing agents are glass or carbon fibers.

All the starting materials and solvents used for the production of the molding compositions according to the invention may contain corresponding impurities from their production and storage, but the aim is still to select as clean as possible starting materials.

The individual components can be mixed in a known manner either successively or simultaneously and can be carried out both at room temperature and at elevated temperature.

The additives can be added to the molding compositions according to the invention by known methods, by mixing the polymer particles with the additives and subsequent extrusion, or by mixing solutions of the polycarbonate with solutions of the additives and subsequent evaporation of the solvent by known methods. The content of additives in the molding composition can vary within wide limits, depending on the properties desired for the molding composition. The total content of additives in the molding composition is up to about 40% by weight, preferably from 4 to 30% by weight, relative to the weight of the molding composition.

The polymer compositions thus obtained can be converted into moulded articles by conventional methods, such as hot pressing, spinning (Spinnen), extrusion or injection moulding. Examples of molded articles include toy parts, also fibers, films, strips, plates, containers, tubes and other profiles. The polymer composition may also be processed into cast films. The present invention therefore also relates to the use of the polymer compositions according to the invention for producing moldings. The use of multilayer systems is also of interest.

The following examples are intended to illustrate the invention in more detail, but are not to be construed as limiting it.

Examples

For example, according to EP-A0110238, 10 mm double-layer panels A, B, C and 16 mm triple-layer panels D and E (referred to there as multi-layer cavity plastic panels) were obtained with the following molding compositions: by using1243 (a branched bisphenol A polycarbonate, manufactured by Bayer AG, Leverkusen, according to ISO 1133, having a melt flow index (MFR) of 6.5 g/10 min at 300 ℃ and a load of 1.2 kg) as substrate. It was compared with bases listed in Table 13108 the compounds are co-extruded together (3108 is a linear bisphenol A polycarbonate having a melt flow index (MFR) of 6.5 g/10 min at 300 ℃ and a load of 1.2 kg according to ISO 1133, manufactured by Bayer AG (Leverkusen). Intermediate coextrusionThe thickness of the laminate was about 60 microns and the thickness of the outer layer was about 45 microns.

The machines and devices for manufacturing the multilayer panels are described below:

the structure includes:

a main extruder with a 33D long screw of diameter 70 mm and a degassing device;

a co-extrusion adapter (feedblock system);

two co-extruders for applying (aufbringer) the intermediate layer and the outer layer, each comprising a screw 25D long and 30 mm in diameter;

-a dedicated sheet die having a width of 350 mm;

-a calibrator;

-a roller conveyor;

-an extraction device;

-a cut-to-length device (saw);

-run-out table.

The substrate polycarbonate in pellet form was introduced into the hopper of the main extruder and the UV co-extrusion material was introduced into the hopper of the respective co-extruder. Melt and deliver the respective materials to the respective barrel/screw plasticizing systems. The two molten materials were collected in the co-extrusion adapter and, upon exiting the extrusion die and cooling in the calibrator, they formed a composite. Other devices are used for transport, cut to length and storage of the extruded sheet material.

The resulting plaques were then evaluated colorimetrically. The following assay methods were used:

1. the transparency was measured according to ASTM E308/ASTM D1003.

2. Yellowness index was determined according to ASTM specification E313.

3. Gloss is measured according to ASTM specification D523.

4. The selectivity parameters were determined according to DIN specification 67507.

Table 1 shows the results based on3108.

TABLE 1

The formulations in table 1 are the compositions of the B layers in the examples and the corresponding layers in the control examples.

1)＝Magna1000, supplied by Costenable GmbH (Eschborn) of Germany;

2)＝AC 870, supplied by Merck KGaA (Darmstadt) of Germany;

3)＝9223 available from Merck KGaA (Darmstadt) of Germany

4) 2, 2' -methylene-bis [4- (1, 1, 3, 3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol ], available from Ciba Specialty Chemicals (Lampertheim) germany.

The pigment structure is as follows:

the core of which consists in each case of micaceous stone.

Magna1000：

TiO on the core₂Layer thickness: 60-110 nm;

AC 870：

innermost TiO on the core₂Thickness of layer: 110-120 nm;

intermediate SiO₂Layer thickness: 110-140 nm;

outermost TiO₂Thickness of layer: 120-150 nm

9223：

TiO on the core₂Thickness of layer: 150-.

The formulations listed in Table 1 were co-extruded into1243 made of 10 mm double layer panels (table 2) and 16 mm triple layer panels (table 3).

TABLE 2

No.	Intermediate coextruded layer	Outer co-extruded layer
			A	Is not provided with	Ingredient 1
B	Is not provided with	Ingredient 2
			C	Is not provided with	Ingredient 3

TABLE 3

No.	Intermediate coextruded layer	Outer co-extruded layer
			D	Ingredient 4	Ingredient 6
E	Ingredient 5	Ingredient 6

The gloss and selectivity parameters of these multilayer panels were determined. The results are shown in Table 5.

TABLE 5

No.	Glossiness (60 degree)	Selectivity parameter
			A	19％	0.81
B	18％	1.13
			C	14％	1.29
D	99％	1.14
			E	98％	1.27

As shown in table 5, only the E sheet met the desired performance profile. A. The gloss of the B and C panels was too low. The selectivity parameter for the D sheet is too low (below 1.15).

Claims (14)

1. A multilayer product comprising A, B and C three layers, wherein the layer B is located between the layers a and C, wherein the layer a comprises a transparent thermoplastic, wherein the layer B comprises a transparent thermoplastic and a pigment consisting of a transparent carrier material and a titanium dioxide layer on the carrier material with a thickness of 150-nm, 200 nm, and wherein the layer C comprises a transparent thermoplastic, wherein the transparent thermoplastic contained in the layers A, B and C is a polycarbonate, or the transparent thermoplastic contained in at least one of the layers A, B and C is a copolyester derived from a dicarboxylic acid and a diol, wherein the dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid and cyclohexane-1, 4-dicarboxylic acid, wherein the diol is selected from the group consisting of ethylene glycol, cyclohexanedimethanol and diethylene glycol, and wherein the content of repeat units derived from diethylene glycol is less than 5 mol% of the content of all repeat units derived from the diol .

2. The multilayer product according to claim 1, wherein the B layer is 15 to 250 microns thick.

3. A multi-layer product according to claim 1, which is a sheet.

4. A multi-ply product according to claim 3, wherein the sheet is a solid sheet.

5. A multi-ply product according to claim 3, wherein the sheet is a corrugated sheet.

6. A multi-layer product according to claim 3, wherein said sheet material is a multi-layer sheet material.

7. A process for the manufacture of a multilayer product according to any one of claims 1 to 6 by coextrusion.

8. Use of a multilayer product according to any of claims 1 to 6 for the manufacture of a partition, roof or insulating glass.

9. Use of a multilayer product according to any of claims 1 to 6 for the production of wall coverings.

10. Use of a multilayer product according to any of claims 1 to 6 for the manufacture of ceiling coverings.

11. Product comprising a multilayer product according to any of claims 1 to 6.

12. A product according to claim 11, selected from roof or insulating glass or partition walls.

13. The product according to claim 11, selected from wall coverings.

14. The product according to claim 11, selected from ceiling coverings.