KR20080103870A - An injection process for making a moulding completely recyclable, multi-layered article - Google Patents

Abstract

An injection process for making a molding completely recyclable, multi-layered article is provided to acquire a product from recycled material in which mechanical properties such as elongation at break and impact resistance is superior enough. An injection process for making a molding completely recyclable, multi-layered article comprises a step of injection molding a hard layer inside mold consisting of two sides; a step of forming small gap of 3~4mm on the hard layer and side of a mold raised or changed; a soft layer made from thermoplastic polymer by injection molding a foaming skin layer within a gap formed the former step; and a foamed skin layer made from the soft layer material and commercial thermoplastic polymer.

Description

An Injection Process for Making a Molding Completely Recyclable, Multi-layered Article}

In the automotive industry, two types of panels and related processing techniques have been used for the interior of vehicles:

i) achieved using injection molding (this method is used in the lower segment of commercial vehicles due to some aesthetic and tactile limitations) and is usually made of PP modified or reinforced PC / ABS, PA / ABS, or other thermoplastic materials Hard inner panels; And

ii) a hard layer, usually achieved using injection molding, made of a material and / or blend of polypropylene and glass fibers (PP GF) or mineral fillers, ABS GF, PC / ABS, PPE / HIPS, SMA, etc. rescue),

A foam layer usually made of polyurethane (PU-foam), and

A skin layer achieved by techniques such as "slush molding", calendering, etc. using materials such as PVC, TPU,

Soft inner panel usually achieved by assembling three different layers.

In the art, the most widely used material for skin layers in instrument panel and interior panel applications is PVC (slush-skin). However, PVC is not compatible with other thermoplastic polymers and the presence of a PU-foam which in some cases imparts the necessary soft feel results in the separation of the material before recovery and regeneration at the end of its lifetime. As is well known from, for example, German patent DE-A-10003595 or patent applications WO 96/33060 and WO 97/48537, self-contained articles surface-finished with a vehicle instrument panel are typically used in a number of steps, typically of a thermoplastic It is prepared in the first step of producing a rigid structure by injection molding using a polymer.

The article is then taken out of the mold and surface finished through a leather or synthetic cover made separately using covers, different techniques and materials, with a layer of quite thin foam material in one or more steps. For example, the leather that is eventually combined with the foam layer can be produced by the "slush molding" technique. Soft inner panels or similar applications made according to the above known techniques have some limitations. In particular, parts manufactured prior to the present invention require three different steps in the manufacturing process, which results in higher equipment investments and processes with more space, more energy consumption, longer assembly times, additional care and pre-assembly parts. This means the need for a warehouse to store. In addition, using the above known method, panels and other internal parts using different techniques and made of different materials cannot be easily reproduced. All different polymer composition layers constituting the composite material must be carefully separated before regeneration. Otherwise, the mechanical properties (eg impact resistance or elongation at break) of the recycled polymer are poor and even in the lowest applications. Thus, regeneration of the composite material is expensive, complex and time consuming.

[Document 1] German Patent DE-A-10003595

[Patent 2] Patent application WO 96/33060

[Document 3] Patent application WO 97/48537

In particular, multilayer molded articles made of polymeric materials for use inside automobiles must meet high requirements, in particular for mechanical properties, surface properties, aging performance and odor performance. Various polymer materials are currently used in the manufacture of automotive interior moldings.

In addition, the molding composition should have a very low density. Low density materials are advantageous for fuel savings and achieving the desired soft feel. In addition, the molding composition should have a very low release of volatile components such that the new molding composition has acceptable odor performance. Finally, the hard layer should provide good adhesion to the foam.

It is an object of the present invention to provide a method obtained by injection molding a multilayer molded article having a fully reproducible structure, and an article obtained from a recycled material having sufficiently good mechanical properties such as elongation at break and impact resistance.

The object is a) injection molding a hard layer in a two-sided mold, and b) raising the one side of the mold or changing one side of the mold so that between 3 and 4 mm between the hard layer and the side of the raised or changed mold. Obtaining a small gap, and c) injecting a foam skin layer into the gap formed in step b), thereby completely regenerating a composition comprising i) a hard layer formed of a thermoplastic polymer and ii) a foam skin layer formed of a thermoplastic polymer compatible with the hard layer material. Achieved by an injection molding method for the production of multilayer articles.

In one embodiment, the object is d) injection molding a hard layer in a two-sided mold, and e) raising one side of the mold or changing one side of the mold to between the hard layer and the side of the raised or changed mold. Obtaining a small gap of 3-4 mm and f) injecting a foam skin layer into the gap formed in step e), i) a hard layer formed of thermoplastic polymer and ii) a foam skin layer formed of thermoplastic polymer compatible with the hard layer material And the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foamed skin layer are both achieved by an injection molding method for the production of a fully regenerated multilayer article.

Herein, the compatibility between the materials used in the production of the hard layer and the foamed skin layer means that the elongation at break of the finished product comprising the hard layer and the foamed skin layer is at least 80% of the elongation at break of the hard layer alone.

The injection molding process of the invention can preferably be carried out according to the following process techniques:

A preferred first process technique is overmoulding, which comprises the following process steps (optionally including a decompression technique):

a) injection molding of a hard layer made of thermoplastic, optionally dissolved gas or chemical blowing agent, and

b) raising or changing one side of the mold to form a small gap, preferably 2 mm to 4 mm, between the hard layer and the mold, and

c) optionally inserting an in-mold decorative (IMD) skin layer film comprising a thermoplastic polymer compatible with the materials used in both the hard and foam layers to improve surface properties,

d) injection molding with a thermoplastic elastic material compatible with the material used as the first layer with a physical or chemical blowing agent to form a foam skin layer, and

e) optionally repeating step b) until the required foam density is obtained and expanding the gap from 10% to 400% of the previous space (decompression molding of the foam layer),

f) optionally, overpainting or IMP (in-mold painting) the foam skin layer after the injection process to achieve a solid top layer of good surface quality and properties.

In the overmolding process, the foam skin layer is formed from a single type of thermoplastic elastomeric material.

In the step of optional In Mold Decoration (IMD), the skin layer film is inserted into the mold to improve the surface properties.

In addition, in the step of optional In Mold Painting, paint is sprayed onto the mold surface and then the material forming the layer is injected. At the end of the process paint remains on the surface of the article. The paint may be colored but is not essential. In general, a transparent protective layer is sufficient for instrument panel applications.

The second process technique disclosed in the present invention is co-injection molding. The technique can achieve better surface quality. The main advantage is that it completely separates the core from the skin. This means preventing any gas on the surface.

In addition, the co-injection makes the core a pure structure, resulting in a low density, non-aesthetic and inexpensive foam layer portion, while providing other functions and high surface properties to the skin portion.

If desired, it is also possible to use co-injection and pressure reduction techniques together in the same process to improve surface properties.

In co-injection molding, the foam skin layer is formed of two different materials, one named S for the skin layer portion and the other named F for the foam layer portion.

The material S may be compatible with the material used for the foam layer part and is also preferably a thermoplastic elastomer compatible with the material used for the layer. Material F is a thermoplastic or foamed thermoplastic foam material compatible with the materials used in the skin layer portion.

The process of manufacturing the co-injection structure includes the following steps.

a) optionally injection molding the hard layer with a dissolved gas or chemical blowing agent,

b) raising one side of the mold or deforming one void to form a small gap, preferably 2 mm to 12 mm, between the hard layer and the mold,

c) optionally inserting an in-mold decorative (IMD) skin layer film comprising a thermoplastic polymer compatible with the materials used in both the hard and foam layers to improve surface properties,

d) The co-injection phase is initiated by injecting a skin layer portion of a thermoplastic material compatible with the material used for the hard layer, filling some of the voids, and then injecting a foam layer portion (core material), thereby removing the initial skin layer portion. Penetrating (the two materials are not mixed and the core is a laminar flow so as not to perforate the skin, the foam layer part is also thermoplastic, optionally foamed by dissolved gas or chemical blowing agent, preferably completely To encapsulate, the skin material is injected at another time to close this part),

e) optionally repeating step b) until the required foam density is obtained to expand the gap to 10% to 400% of the previous space (decompression molding of the foam layer) and

f) optionally, overpainting the foam skin layer after injection molding, or using an in-mold painting technique (IMP) to achieve a solid top layer of good surface quality and properties.

Various foaming techniques and additives are used in the plastics market to achieve low density, good aesthetics on the skin surface and excellent foam structure of the foamed skin layer.

As is well known, current foaming techniques have some obvious limitations, the main limitation being that the cell size is large and not uniform. This drawback can exacerbate both mechanical properties (eg impact strength, brittleness and fatigue resistance) and aesthetics due to the difficulty of controlling gas concentration and release into the melt.

Uniform nucleation is required to solve the above-mentioned problems, including large amounts of blowing agents or dissolved gases, high temperatures and high pressures to form single phase solutions.

The following two main foaming techniques using thermoplastic polymers are used.

i) physical foaming using common atmospheric gases, such as carbon dioxide (CO ₂ ) or nitrogen (N ₂ ), directly mixed with the material inside the injection screw, and

ii) chemical foaming which achieves foaming by decomposition of the blowing agent (CBA) during the process.

The chemical decomposition may be endothermic or exothermic. Endothermic blowing agents produce mainly CO ₂ , while exothermic blowing agents produce mainly N ₂ .

There are many chemical blowing agents (CBAs), including organic and inorganic blowing agents; Azodicarbonamide (ADC); 4,4-oxybis benzene sulfonyl hydrazide (OBSH); p-toluene sulfonyl hydrazide (TSH); 5-phenyltetrazole (5-PT); p-toluene sulfonyl semicarbide (PTSS); Dinitroso pentamethylene tetramine (DNPT); Sodium bicarbonate (SBC); Zinc carbonate (ZnCO ₃ ) and the like.

It is an object of the present invention to achieve good soft feel, aesthetics, low density (0.2 to 0.8 g / cm ³ ) and good foam structure with regard to bubble size uniformity.

Another important goal is to maintain the lowest volatile emissions (required in the automotive sector in recent years).

In view of the needs, most organic blowing agents are not proposed due to environmental issues.

The choice of preferred foaming technique in connection with the present invention depends on the desired thickness of the molded article. For example, physical foaming is preferred for large gaps of greater than about 100% (using reduced pressure molding of foaming layers).

Many different solutions have been tested, but two preferred embodiments used physical foaming techniques, while in the second embodiment, chemical blowing agents were used together inside the polymer to obtain satisfactory results.

The preferred solution is as follows.

a) controlling the level of pressure used to physically foam the molded part, to mix gases and materials in a uniform phase. The most important factor in the process proved to be a very high pressure level. Preferred conditions are a mixing pressure of greater than 350 bar, high content (0.1 to 2% by volume) of atmospheric gases such as carbon dioxide (CO ₂ ) or nitrogen (N ₂ ). The material temperature in the barrel depends on the polymer used and is generally 170 to 280 ° C. In order to achieve the required esthetics and accurate foam structure, fine correction and monitoring of the mold opening speed during decompression is required after foam layer injection.

b) The moldings are combined with physical and chemical foaming, mixing the blowing agent in different fractions. The technique increases the surface side where a good foam structure is maintained. The operating conditions remain the same as described in a) above. The plastic material is mixed with the chemical blowing agent before the process. Preferred formulations are from 0.1 to 3% by weight sodium carbonate-based additives (or other inorganic blowing agents).

Molded articles obtained using the solutions mentioned above exhibit evenly distributed, uniformly sized micro cells (generally between 20 and 100 μm, depending on the material and process conditions). Foam materials prepared under the conditions described above provide improved density and uniformity of the cell structure compared to other foam systems and demonstrate lower VOC emissions.

In another approach, testing polymer microsphere cells encapsulating gases that increase pressure and volume upon heating has yielded poor results in terms of reduced density and narrow process windows due to short residence times.

In some cases, special properties of the skin layer, such as various color finishes, scratch resistance, are required in the present invention.

Part of this need can be achieved by inserting an in-mold decorative (IMD) skin film layer of thermoplastic polymer compatible with the hard and foam skin layers.

Due to their thin thickness equivalent to the film, the layer is achieved by various techniques such as extrusion and / or film blowing, and film blowing is preferred due to cost savings.

Generally, no layer film preprocessing, such as preforming, is performed because of technology conversion, material flexibility, and compatibility with other layers.

In many cases where the geometry of the molded part requires very small radii or sharp shapes, it is possible to preheat some areas of the film to increase the forming properties or direct workability with the preformed layer film.

In order to allow for regeneration of the article, the layer film must be compatible with the hard and foam skin layer materials such that no chemical bonds are formed between the in-mold molded skin layer film and the foam skin layer without any adhesive or subsequent processing.

The IMD layer film can be made using a variety of techniques, but using a compatible material, the preferred solution is that of the same group as the foamed skin layer, made of a material having other properties such as hardness, color, UV stability, etc. .

In connection with this process, the layer film is inserted into the mold on the leather corrugated surface side before the foam layer is injected.

The thickness of the layer can vary depending on the geometry of the leather, the material group and the molded part, in particular the contour and angle.

In order to reduce costs and to carry out a one-time process, the film can be formed into a flat film in the form required by the heat and pressure of the injected melt without mimicking any surface finish and surface treatment.

Important process parameters include material filling rate adjustment and molding temperature control for proper film stretching.

Another main point for the mold is to remove the air between the film and the substrate with the gate type and location, the emission from the core side, and a suitable exhaust.

The process is briefly described below.

i) placing the IMD layer film onto the mold using a roll or robot (available by cutting the flat film insert in advance),

ii) optionally applying vacuum or internal pressure to the voids to maintain the layer film in contact with the mold surface,

iii) inserting into the mold behind the foam layer to bond the hard layer and the IMD layer film and copying the surface treatment from the layer film.

If the IMD layer film was not preformed, after molding the excess IMD layer film was typically trimmed, folded and wound around the dividing line.

The above mentioned solution is a much more environmentally beneficial process than painting and in-mold painting techniques, and also ensures skin properties requirements, easier applicability in terms of surface appearance and cost savings.

matter

Various thermoplastics are suitable for use in the injection molding disclosed herein. Some polymers suitable for the hard layer, foam skin layer and IMD layer films are listed below.

Preferably,

i) hard layers include PP, PBT, SMA, SAN, ABS; Formed of ABS / AMSAN-, ABS / PC-, ABS / PA-, PBT / PET-, PBT / ASA or PPE / HIPS-blend,

ii) The foam skin layer is formed of TPC / PBT, TPO, TPU or PVC.

More preferably,

i) the hard layer is formed of a fiber reinforced PBT / ASA blend,

ii) The foam skin layer is formed of TPC / PBT or TPU.

More preferably,

i) the hard layer is formed of fiber reinforced PP,

ii) The foam skin layer is formed of TPC / PBT or TPU.

Particularly preferably,

i) the hard layer is formed of a fiber reinforced ABS / PA blend,

ii) The foam skin layer is formed of TPC / PBT or TPU.

In a preferred embodiment,

i) hard layers include PP, SMA (styrene maleic anhydride), SAN (styrene acrylonitrile), ABS;

PPE (polyphenylene ether) / HIPS-, ABS / AMSAN (alpha-methyl-SAN)-, ABS / PC (polycarbonate)-or ABS / PA (polyamide)-, PBT / ASA, or PBT / PET blend,

In particular, PBT / ASA having a glass, carbon, or thermoplastic fiber content of 0 to 30% by weight;

In particular, ABS / PA having a glass, carbon, or thermoplastic fiber content of 0 to 30% by weight;

In particular, SAN having a glass fiber content of 10 to 50% by weight including long glass fibers;

In particular, PP having a 10-50% by weight glass fiber content comprising long glass fibers (also using 10-40% by weight of fillers: calcium stearate, talc, wollastonite); And

ii) foamed skin layer consisting of TPC / PBT (defined in [PF 57804, page 16, line 20ff]), TPO (thermoplastic polyolefin), TPU (thermoplastic polyurethane) or PVC, in particular TPC / PBT or TPU It is prepared from a material selected from.

Most preferred embodiments are shown in the table below:

Hard layer Foam layer Fiber reinforced PP U TPC / PBT PP U TPU SAN U TPC / PBT SAN U TPU PBT / ASA U TPC / PBT PBT / ASA radish TPC / PBT PBT / ASA U TPU PBT / ASA radish TPU ABS / PA U TPC / PBT ABS / PA radish TPC / PBT ABS / PA U TPU ABS / PA radish TPU

Hard layer:

The hard layer preferably comprises 45 to 100% by weight, more preferably 55 to 90% by weight, particularly preferably 80 to 90% by weight of polybutylene terephthalate (PBT) as component A1. In addition to PBT, further aromatic polyesters can be used as component A2.

The further aromatic polyesters are preferably reacted with terephthalic acid, its esters or other ester-forming derivatives with 1,4-butanediol, 1,3-propanediol, or 1,2-ethanediol, respectively, in an essentially known manner. Are manufactured. Up to 20 mole percent of terephthalic acid may be replaced by other dicarboxylic acids. Here, by way of example only, naphthalene dicarboxylic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid and cyclohexanedicarboxylic acid, mixtures of these carboxylic acids, and ester-forming of these compounds Derivatives may be mentioned. Up to 20 mol% of each of the dihydroxy compounds 1,4-butanediol, 1,3-propanediol and 1,2-ethanediol are also other dihydroxy compounds, such as 1,6-hexanediol, 1,4- Hexanediol, 1,4-cyclohexanediol, 1,4-di (hydroxy-methyl) cyclohexane, bisphenol A, neopentyl glycol, mixtures of these diols, or other ester-forming derivatives of these compounds have.

Further aromatic polyesters are, for example, polytrimethylene terephthalate (PTT), in particular polyethylene terephthalate (PET) formed from terephthalic acid, propanediol and 1,4-butanediol. Some or all of the aromatics may be, for example, in the form of recycled polyester material regrind from container material or container production waste. In particular, the PBT or PBT / PET blend consists of recycled polyester, and the vehicle shaped portion can be easily recycled by itself.

In a particularly preferred embodiment, component A is 70 to 100% by weight, preferably 80 to 100% by weight, particularly preferably 90 to 100% by weight of PBT, and 0 to 30% by weight, preferably 0 to 20% by weight. %, Particularly preferably 0 to 10% by weight of PET. More preferred are molding compositions wherein the component A is free of PET.

The novel molding compositions are component B, from 0 to 25% by weight, preferably from 3 to 20% by weight, particularly preferably from 10 to 15, wherein the soft phase has a glass transition temperature of less than 0 ° C. and has a median particle size of 50 to 1000 nm. By weight of one or more particulate graft copolymers.

Component B is preferably

50 to 90% by weight of a graft graft base material B1 having a glass transition temperature of less than 0 ° C., and

b21) from 50 to 90% by weight of vinylaromatic monomer as component B21, and b22) from 10 to 50% by weight of graft B2 prepared from 10 to 50% by weight of acrylonitrile and / or methacrylonitrile as component B22.

Graft copolymers prepared from.

The granular graft base B1 may consist of 70-100% by weight of C ₁ -C ₁₀ -alkyl acrylate, and 0-30% by weight of two non-conjugated olefin double bonds.

In a preferred embodiment of the invention, the graft base B1 is

75 to 99.9% by weight of C ₁ -C ₁₀ -alkyl acrylate as component B11,

At least one polyfunctional monomer having from 0.1 to 10% by weight of at least two non-conjugated olefin double bonds as component B12, and

As component B13, from 0 to 24.9% by weight of one or more other copolymerizable monomers.

The graft base B1 is an elastomer having a glass transition temperature of preferably below -20 ° C, particularly preferably below -30 ° C. The main monomer B11 used to prepare the elastomer is an acrylate having 1 to 10 carbon atoms, especially 4 to 8 carbon atoms, in the alcohol moiety. Particularly preferred monomers B11 are isobutyl and n-butyl acrylate, and also 2-ethylhexyl acrylate, particularly preferably butyl acrylate.

In addition to the acrylates, the crosslinking monomers B12 used are from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, particularly preferably from 1 to 4% by weight of polyfunctional monomers having at least two non-conjugated olefin double bonds. to be. Examples of these are divinylbenzene, diallyl fumarate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, tricyclodecenyl acrylate and dihydrodicyclopentadienyl acrylate, particularly preferred To be the last two.

In addition to the monomers B11 and B12, the structure of the graft base B1 is also 24.9% by weight or less, preferably 20% by weight or less of other copolymerizable monomers, preferably 1,3-butadiene, styrene, α-methylstyrene, acrylonitrile , Methacrylonitrile and C ₁ -C ₈ -alkyl methacrylates, or mixtures of these monomers. In a particularly preferred embodiment, 1,3-butadiene is not present in the graft base B1, in particular the graft base B1 consists exclusively of components B11 and B12.

The graft B2 grafted on the graft base B1

50-90% by weight, preferably 60-90% by weight, particularly preferably 65-80% by weight of vinylaromatic monomer as component B21, and

As component B22 from 10 to 50% by weight, preferably from 10 to 40% by weight, particularly preferably from 20 to 35% by weight of acrylonitrile or methacrylonitrile, or mixtures thereof.

Examples of vinylaromatic monomers are unsubstituted styrene and substituted styrenes such as α-methylstyrene, p-chlorostyrene and p-chloro-α-methylstyrene. Preferably, unsubstituted styrene and α-methylstyrene, in particular unsubstituted styrene.

In one embodiment of the present invention, the median particle size of component B is between 50 and 200 nm, preferably between 55 and 150 nm.

In another embodiment of the invention, the median particle size of component B is between 200 and 1000 nm, preferably between 400 and 550 nm.

In another preferred embodiment of the invention, component B has a bimodal particle size distribution, 10-90% by weight, preferably 30-90, with a median particle size of 50-200 nm, preferably 55-150 nm. Wt-%, particularly preferably 50-75 wt-% of the fine-particle graft copolymer, and 10-90 wt-%, preferably 10-70, with a median particle size of 250-1000 nm, preferably about 400-550 nm Weight percent, particularly preferably 25 to 50 weight percent of the coarse-particle graft copolymer.

The median particle size and particle size distributions presented are the sizes determined from the integral mass distribution. The median particle size according to the invention is in all cases the median median of the particle size. This was done using an analytical ultracentrifuge [W. Scholtan and H. Lange, Kolloid-Z. and Z.-Polymere 250 (1972), pages 782-796. Ultracentrifuge measurements provide an integral mass distribution of the particle diameter of the specimen. From this, it is possible to deduce how many percent, based on the weight of the particles, have a diameter equal to or smaller than the particle size. The median particle size, also referred to as d ₅₀ of the integral mass distribution, is defined as the particle diameter when ₅₀ % by weight of the particles have a diameter smaller than the corresponding d ₅₀ . To describe the width of the particle size distribution of the rubber particles, d ₁₀ and d _90, given by the integral mass distribution, are used together with d ₅₀ (medium particle size). D ₁₀ and d ₉₀ of the integral mass distribution are defined as d ₅₀ , with the difference that they are based on 10% and 90% by weight of the particles, respectively. The ratio (d ₉₀ -d ₁₀ ) / d ₅₀ = Q is a measure of the width of the particle size distribution. The emulsion polymer A which can be used according to the invention as component A preferably has a Q of less than 0.5, in particular less than 0.35.

Graft copolymers B are generally polymers having at least one phase, ie consisting of one core and at least one shell. This polymer consists of a substrate (graft core) B1 and one, or preferably at least one phase B2 (graft), known as a graft or graft shell, grafted thereon.

One or more graft shells may be applied to rubber particles by grafting one or more times. Each graft shell can have a different configuration. In addition to the grafting monomers and together with the grafting monomers, polyfunctional crosslinking monomers or reactive group containing monomers may be grafted (eg EP-A 0 230 282, DE-A 36 01 419, EP- A 0 269 861).

In one embodiment of the invention, the crosslinked acrylate polymer having a glass transition temperature of less than 0 ° C. functions as the graft base B1. The crosslinked acrylate polymer should preferably have a glass transition temperature of below -20 ° C, in particular below -30 ° C.

Also in theory, the structure of the graft copolymer may have two or more layers in which the glass transition temperature of at least one inner layer is less than 0 ° C. and the glass transition temperature of the outermost layer is more than 23 ° C.

In one preferred embodiment, graft B2 consists of one or more graft shells. Its outermost graft shell has a glass transition temperature above 30 ° C. Polymers formed from the monomers of graft B2 will have a glass transition temperature greater than 80 ° C.

Suitable methods for preparing the graft copolymer B include emulsion, solution, bulk and suspension polymerization methods. Graft copolymer B is preferably prepared by free radical emulsion polymerization or using a redox initiator with a water-soluble and / or oil-soluble initiator such as peroxodisulfate or benzoyl peroxide at a temperature of 20-90 ° C. It is manufactured as a supplement. Redox initiators are also suitable for polymerization at less than 20 ° C.

Suitable emulsion polymerization processes are described in DE-A-28 26 925, DE-A-31 49 358 and DE-C-12 60 135.

The graft shell is preferably constructed by an emulsion polymerization process as described in DE-A-32 27 555, 31 49 357, 31 49 358 and 34 14 118. The setting of the particle size according to the invention, preferably from 50 to 1000 nm, is described in DE-C-12 60 135 and DE-A 28 26 925, or in Applied Polymer Science, Vol. 9 (1965), page 2929. The use of polymers of different particle sizes is known, for example, from DE-A 28 26 925 and US Pat. No. 5,196,480.

The novel molding compositions comprise 0.1 to 10% by weight of conventional additives as component I. Examples of this type of additives include UV stabilizers, transesterification stabilizers, oxidation retardants, lubricants, release agents, dyes, pigments, colorants, nucleators, antistatic agents, antioxidants, improving thermal stability and increasing light stability. And stabilizers for increasing hydrolysis resistance and chemical resistance, anti-pyrolysis agents, in particular lubricants useful in the production of moldings. These other additives may be metered in at any stage of the manufacturing process, but are preferably metered in initially to use the stabilizing effect (or other specific effects) of the additive at the initial stage. Thermal stabilizers or oxidation retardants are typically metal halides (chloride, bromide or iodide) derived from the Group I metals (eg Li, Na, K or Cu) of the Periodic Table of Elements.

Suitable stabilizers include conventional sterically hindered phenols, or vitamin E or compounds of similar structure. In addition, benzophenone, resorcinol, salicylate, benzotriazole and other components (e.g. Irganox®, Tinuvin®, such as Tinuvin® 770 (HALS (hindered amine light) Stabilizers) Absorbent, Bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate) or Tinuvin® P (UV absorber, (2H-benzotriazol-2-yl) -4 HALS stabilizers such as -methylphenol) or Topanol®) are suitable. Typical amounts of use are 2% by weight or less based on the total mixture.

Suitable transesterification stabilizers include organic phosphonites such as tetrakis (2,4-di-ter-butylphenyl) bisphenylenediphosphonite (Riga, manufactured by Ciba Geigy AG) Phos (Irgaphos® PEPQ) and mono phosphates (mono- or dihydrate). Transesterification stabilizers can be used, for example, in powder form or as PBT masterbatches.

Suitable lubricants and mold release agents include stearic acid, stearyl alcohol, stearates and higher fatty acids, usually 12 to 30 carbon atoms, derivatives thereof and corresponding fatty acid mixtures. The amount of such additives is 0.05 to 1% by weight.

Other possible additives include silicone oils, oligomeric isobutylene and similar materials. The amount is usually 0.05 to 5% by weight. In use, pigments, dyes, optical brighteners such as ultramarine blue, phthalocyanine, titanium dioxide, cadmium sulfide or derivatives of perylenetetracarboxylic acid can be used.

Processing aids and stabilizers such as UV stabilizers, lubricants and antistatic agents are generally used in amounts of 0.01 to 5% by weight, based on the total molding composition.

Nucleating agents such as talc, calcium fluoride, sodium phenylphosphinate, alumina or fine polytetrafluoroethylene can also be used, for example in amounts of up to 5% by weight, based on the total molding composition. Plasticizers such as dioctyl phthalate, dibenzylphthalate, butyl benzyl phthalate, hydrocarbon oil, N- (n-butyl) benzenesulfonamide, or o- or p-tolueneethylsulfonamide may be up to 5% by weight based on the molding composition It can be advantageously added in an amount. Colorants such as dyes or pigments may also be added in amounts up to 5% by weight based on the molding composition.

The hard layer preferably has a layer thickness of 1 to 10 mm, particularly preferably 1 to 4 mm.

Foam skin layer and in-mold decorative layer film

The foamed skin layer and the phosphorus mold decorative layer film material usable in the process according to the invention comprise thermoplastic polyester elastomers (TPC) containing polybutylene terephthalate (PBT).

Thermoplastic polyester elastomers (TPC) refer to segmented copolyesters containing hard polyester segments and soft segments of flexible polymers or oligomers that are substantially amorphous and have a glass transition temperature (Tg) of less than 0 ° C. Copolyester is also referred to as copolyether ester (TPC-ET) when the soft segment is polyether, and copolyester is represented as copolyester ester (TPC-ES) when the soft segment is polyester If the segment contains ester and ether linkages, the copolyester is referred to as TPC-EE.

These segmented copolyesters are composed of a plurality of long-chain ester repeating units (soft segments) and short-chain ester repeating units (hard segments) connected to each other in a head-to-tail form through an ester type linking chain. It is understood to have.

The short chain unit may be represented by the following formula (I).

<Formula I>

-O-D-O-CO-R-CO

The long chain ester unit may have the following formulas IIa and / or IIb.

<Formula IIa>

-O-G-O-CO-R-CO

<Formula IIb>

-O-D-O-CO-A-CO

Where

D is a divalent radical having a molecular weight of less than about 250 remaining after removal of the hydroxyl groups from the alkylene glycol,

R is a divalent radical having a molecular weight of less than about 300 remaining after removing a carboxyl group from a dicarboxylic acid,

G is a divalent radical having a molecular weight of about 250 to about 6,000 remaining after removal of the hydroxyl end groups from the long chain glycol,

A is a divalent radical remaining after removal of a carboxyl group from an unsaturated or saturated long chain dicarboxylic acid,

O is oxygen.

The term "short-chain ester unit" in connection with the units present in the polymer chain relates to the reaction product of a low molecular weight (less than about 250) diol (D) with dicarboxylic acid in the formation of the ester unit represented by formula (I) above. Among the low molecular weight diols that can react to form short chain ester segments are non-cyclic, cycloaliphatic and aromatic dihydroxy compounds. Diols having 2 to 15 carbon atoms, such as ethylene-glycol, propylene-glycol, isobutylene-glycol, tetramethylene-glycol, pentamethylene-glycol, 2,2-dimethyl-trimethylene-glycol, hexamethylene-glycol, deca Methylene glycol, dihydroxy-cyclohexane, cyclohexane-dimethanol, resorcinol, hydroquinone, 1,5-dihydroxy-naphthalene and the like are preferable. Particular preference is given to aliphatic diols having 2 to 8 carbon atoms. Aromatic dihydroxy compounds that may also be used include bisphenols such as bis- (p-hydroxy) -diphenyl, bis- (p-hydroxyphenyl) -methane and bis- (p-hydroxyphenyl) -propane have. Equivalent ester-forming derivatives of diols can also be used (eg ethylene oxide or ethylene carbonate can be used in place of ethylene glycol). Thus, the term "low molecular weight diol" as used in this context should be understood to include all derivatives suitable for forming esters. However, the conditions relating to molecular weight apply only to diols, not to their derivatives. 1,4-butane-diol should be at least part of the diols used.

Dicarboxylic acids (R) which can be reacted with low molecular weight diols and long chain glycols to prepare the copolyesters according to the invention include low molecular weights, ie aliphatic, cycloaliphatic or aromatic dicarboxylic acids having a molecular weight of less than about 300. . The term “dicarboxylic acid” as used herein also includes equivalent derivatives of dicarboxylic acids which exhibit substantially similar behavior to dicarboxylic acids in the reaction with glycols and diols to form copolyester polymers. Such equivalent compounds include esters and ester-forming derivatives such as halides and anhydrides. However, conditions relating to molecular weight always refer to acids and not to their equivalent esters or derivatives thereof suitable for forming esters. Thus, the term “dicarboxylic acid” refers to an ester of a dicarboxylic acid having a molecular weight greater than about 300, or an equivalent of a dicarboxylic acid having a molecular weight greater than about 300, provided that the molecular weight of the corresponding acid is still less than about 300. Include. The dicarboxylic acid may contain any substituent or any combination of substituents that does not significantly inhibit the formation of the copolyester polymer and the use of the polymer in the final product according to the invention. In the context of the present invention, "alicyclic dicarboxylic acid" means a carboxylic acid containing two carboxyl groups, wherein each of the carboxyl groups is bonded to a saturated carbon atom. If the carbon atom to which the carboxyl group is bonded is saturated and inside the ring, the acid is alicyclic. The term "aromatic dicarboxylic acid" as used in this context refers to a dicarboxylic acid containing two carboxyl groups. The two functional carboxyl groups need not be attached to the same aromatic ring, and if more than one ring is present it can be linked by an alicyclic or aromatic divalent radical or a divalent radical such as -O- or -SO _2- . Each carboxyl group is bonded to a carbon atom of an isolated or condensed aromatic ring.

Examples of aromatic dicarboxylic acids that can be used include phthalic acid, isophthalic acid and terephthalic acid, dibenzoic acid; Dicarboxylic compounds comprising two benzene rings, such as 4.4'-diphenyl dicarboxylic acid, bis- (para-carboxyphenyl) -methane, paraoxy- (para-carboxyphenyl) -benzoic acid, ethylene-bis- (Paraoxy-benzoic acid), 1,5-naphthalene-dicarboxylic acid, 2,6-naphthalene-dicarboxylic acid, 2,7-naphthalene-dicarboxylic acid, phenanthrene-dicarboxylic acid, anthracene- Dicarboxylic acids, 4,4-sulfonyl-dibenzoic acids and their (C 1 -C 12) -alkyl derivatives and ring-substituted derivatives such as halogenated (eg F, Cl, Br) derivatives, (preferably C1 to 4) alkoxy derivatives and aryl derivatives.

Aromatic acids containing hydroxy groups, such as para- (beta-hydroxyethoxy) -benzoic acid, may also be used provided that (aromatic) dicarboxylic acids are also present.

Aromatic dicarboxylic acids constitute a preferred class of acids for the preparation of the copolyesters according to the invention.

Among the aromatic acids, it is preferable to contain 8 to 16 carbon atoms, with phenylene dicarboxylic acid, ie phthalic acid, isophthalic acid and terephthalic acid being particularly preferred. In particular, terephthalic acid or a mixture of terephthalic acid and isophthalic acid alone is preferable.

Terephthalic acid should be at least part of the acid used.

The term “long chain ester unit” also applies to units having formula (IIb) which is the reaction product of long chain dicarboxylic acids and low molecular weight diols.

Long-chain dicarboxylic acids (A) are dimerized fatty acids. The term "dimer fatty acid" is well known in the art and refers to the dimerization reaction product of mono- or polyunsaturated fatty acids. Preferred dimer acids are dimers of C10 to C30, more preferably C12 to C24, especially C14 to C22, and more particularly C18 alkyl chains. Suitable dimer fatty acids include the dimerization reaction products of oleic acid, linoleic acid, pamitoleic acid, ellideic acid, or erucic acid. It is also possible to use dimerization reaction products of unsaturated fatty acid mixtures obtained from the hydrolysis of natural fats and oils such as sunflower oil, soybean oil, olive oil, rapeseed oil, cottonseed oil and tall oil.

Among the dimer acid products, hydrogenated dimer acid products are preferred, and purified and hydrogenated dimer fatty acids are particularly preferred.

Suitable long chain glycols (G) for preparing the polymers according to the invention include poly- (alkylene oxide) -glycols, where "alkylene" is preferably alkylene of C2 to 10], such as poly- (ethylene Oxide) -glycol, poly- (1,2- and -1,3-propylene oxide) -glycol, poly- (tetramethylene oxide) -glycol, poly- (pentamethylene oxide) -glycol, poly- (Hexamethylene oxide) -glycol, poly- (heptamethylene oxide) -glycol, poly- (octamethylene oxide) -glycol, poly- (nonmethylene oxide) -glycol, poly- (decamethylene oxide) -Glycols and poly- (1,2-butylene oxide) -glycols; Random copolymers or block copolymers of ethylene oxide and 1,2-propylene oxide; Polyformal prepared by the reaction of formaldehyde with glycol, such as pentamethylene-glycol, or glycol mixtures such as tetramethylene-glycol and pentamethylene-glycol; Dicarboxylic methyl acids of polyalkylene oxides, such as those derived from poly (tetramethylene oxide) or esters thereof. In addition, both poly-isoprene-glycol and poly-butadiene-glycol, copolymers thereof and saturated products obtained by hydrogenation thereof can be used as long chain polymer glycols. In addition, glycol-esters of dicarboxylic acids formed by oxidation reactions of polyisobutylene-diene copolymers may be used as raw materials. Preferred long chain glycols are poly (tetramethylene oxide) glycols having a number average molecular weight of 600 to 4000 and poly (ethylene oxide) glycols and / or poly- (1,2- and -1, having a number average molecular weight of 1000 to 3000, 3-propylene oxide) -glycol.

Most preferred is poly- (tetramethylene oxide) -glycol in the present invention.

Long chain glycols also include dimerized fatty diols derived from hydrogenation of high-purity dimer fatty acids, or mixtures of poly (alkylene oxide) glycols and dimer fatty diols. Among the dimer diol products, those derived from hydrogenation of high purity dimer fatty acids are preferred.

The ratio of soft to hard segments in the copolyesters described above can vary within wide limits, but is preferably selected such that relatively low hardness copolyether esters are obtained. The hardness of the copolyether esters is preferably less than 50 Shore D, more preferably less than 40 Shore D. In a preferred embodiment, 20 to 40 Shore D. Lower hardness copolyether esters generally result in improved low temperature performance and better soft feel, or soft touch, of the laminate product obtained according to the process of the present invention.

As a result of producing a polymer having a desirable balance of elastic properties and toughness, the short-chain ester units having the formula (I) are about 10 to 95% by weight of copolyester, preferably about 10 to 55% by weight, and more preferably about 13 to 40% by weight. The remainder of the copolyester is a long chain ester unit constituting about 5 to 90 weight percent, preferably 45 to 90 weight percent, and more preferably 60 to 87 weight percent of the copolyester, represented by Formula IIa or IIb above. ]

Preferred copolyester elastomers for use in the composition of the foamed skin layer of the present invention and the molded decorative film layer have dimethyl terephthalate, 1,4-butanediol and a number average molecular weight of about 600 to 4000, more preferably about 1000 Prepared from poly (tetramethylene oxide) glycol from 2000 and / or poly (ethylene oxide) glycol and / or poly- (1,2- and -1,3-propylene oxide) -glycol having a molecular weight of about 1000 to 3000 will be.

Particular preference is given to Pibiflex® thermoplastic polyesters of P-Group (Ferrara, Italy). It is more preferable for the composition of this invention that it is Shore D of less than 40 among fibiplex copolyesters.

A further object of the present invention is

i) a hard layer formed of a thermoplastic polymer and

ii) a foamed skin layer formed of a thermoplastic polymer compatible with the material of the hard layer

Made of

Both the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foamed skin layer comprise polybutylene terephthalate, the hard layer comprising

45 to 100 weight percent polybutylene terephthalate as component A1,

As component A2, from 0 to 30% by weight polyethylene terephthalate and

Component B, comprising 0 to 25% by weight of an ASA copolymer

It is to provide a fully reproducible multilayered article.

Also in additional alternatives,

i) a hard layer formed of a thermoplastic polymer and

ii) a foamed skin layer formed of a thermoplastic polymer compatible with the material of the hard layer

Made of

Both the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foamed skin layer both comprise polybutylene terephthalate, the foamed skin layer forming thermoplastic polymer being a soft segment, a plurality of repeating long chain ester units and a plurality of hard segments. Having a repeating short chain ester unit, wherein the short chain unit is represented by the following formula (I), and the long chain ester unit is represented by the formulas (IIa) and / or (IIb) below.

<Formula I>

-O-D-O-CO-R-CO

<Formula IIa>

-O-G-O-CO-R-CO

<Formula IIb>

-O-D-O-CO-A-CO-

In the above formula

D is a divalent radical remaining after removal of hydroxyl groups from an alkylene glycol having a molecular weight of less than about 250 (at least a portion of the alkylene glycol used is 1,4-butane-diol),

R is a divalent radical remaining after removal of a carboxyl group from a dicarboxylic acid having a molecular weight of less than about 300 (at least part of the dicarboxylic acid used is terephthalic acid),

G is a divalent radical remaining after removal of hydroxyl end groups from long chain glycols having a molecular weight of about 250 to about 6000,

a. A is a divalent radical remaining after removal of a carboxyl group from an unsaturated or saturated long-chain dicarboxylic acid having 1 to 25 carbon atoms

b. O is oxygen.

Preferably the hard layer is

45 to 100 weight percent polybutylene terephthalate as component A1,

As component A2, from 0 to 30% by weight polyethylene terephthalate and

Component B, comprising 0 to 25% by weight of ASA copolymer,

The foamed skin layer forming thermoplastic polymer has a plurality of repeating long chain ester units as soft segments and a plurality of repeating short chain ester units as hard segments,

The short chain unit is represented by the formula (I)

The long chain ester units are represented by the formulas (IIa) and / or (IIb) below.

<Formula I>

-O-D-O-CO-R-CO

<Formula IIa>

-O-G-O-CO-R-CO

<Formula IIb>

-O-D-O-CO-A-CO-

Where

D is a divalent radical remaining after removal of hydroxyl groups from an alkylene glycol having a molecular weight of less than about 250 (at least a portion of the alkylene glycol used is 1,4-butanediol),

R is a divalent radical remaining after removal of a carboxyl group from a dicarboxylic acid having a molecular weight of less than about 300 (at least part of the dicarboxylic acid used is terephthalic acid),

G is a divalent radical remaining after removal of hydroxyl end groups from long chain glycols having a molecular weight of about 250 to about 6000,

A is a divalent radical remaining after removal of a carboxyl group from an unsaturated or saturated long chain dicarboxylic acid having 1 to 25 carbon atoms,

O is oxygen.

<Application and Example>

The high heat resistance, good heat aging resistance, good mechanical properties and good surface properties of the novel molding compositions make them suitable for the wide variety of moldings in which these molding compositions are present. By way of example only, mention may be made of a camera case, a case for a mobile phone, a tube part for binoculars, a steam tube for a steam extraction hood, a component for a pressure cooker, a housing for a hot grill and a pump housing.

The above mentioned properties make the novel molded parts particularly suitable for automotive applications.

Examples of novel shaped articles specially made from the novel molding compositions are parts such as optical switch housings, housings for central electrical systems, multipoint connectors and plug connectors, ABS control housings, registration plate supports, and also roof shelves.

The good exhaust performance of the novel molded parts makes them particularly suitable for automotive interior applications. The new moldings thus produced from the novel molding compositions are preferably protective covers, storage compartments, instrument cluster supports, door breasts, parts for center consoles, retaining elements for radio and air conditioning systems, covers for center consoles, covers for radios, air conditioners Systems and ashtrays, extensions for the center console, storage pockets, storage parts for the driver's doors and occupants' doors, storage parts for the center console, components of the driver's and passenger seats, eg set covers, defroster tubes, interior mirror housings , Sunroof elements, eg sunroof frames, instrument covers and protective trims, instrument sockets, upper and lower shells for control columns, air lines, air blowers and adapters and defroster tubes for personal air flow devices, door side covers , Knee cover, air exhaust exposure, defrosting openings, switches and levers, and also air filter tubes and vents, and especially these A reinforcing component. These applications are merely examples of possible applications inside automobiles. The novel molded article is particularly preferably laser marked.

Also preferred are molded parts for exterior body parts, in particular fenders, tailgates, side paneling, bumpers, paneling, license plate supports, panels, sunroofs, sunroof frames, and also impact protectors and their components. .

Other applications that may be mentioned as other moldings include the automotive sector and hulls, lawn mower housings, garden furniture, motorcycle parts, camera cases, mobile phone cases, tubular parts for binoculars, steam tubes for steam extraction hoods, parts for pressure cookers It is not limited to the housing for the hot grill and the pump housing.

The molding compositions are suitable for plug connectors and housing parts, and especially for large transportation electronics, in particular for electronics for ABS / ASC, for transmission systems for ESPs, for seats, mirror motors, for window lifter motors, for flexible roofs, for airbag brakes, in passenger compartments. It has proven to be particularly useful for molded articles such as stability, acceleration sensors, and ignition electronics, and also seat occupancy sensing electronics. Other preferred uses of the novel molding compositions are for locking system housings, automatic relays and covers of wiper housings, and also for locking housings. Another preferred group of moldings that can be produced from the novel molding compositions are gas metering housings, wind deflectors, operating motor housings, preferably for use in the construction of motor vehicles, power drill parts, oven parts, especially heat Insulation from, for example, handles and oven handles, screen wiper parts, in particular wiper blade retainers, spoilers, mirror support plates for automotive mirrors, and also housings for dishwasher control systems.

The novel molding compositions are also suitable for other shaped articles used in the household sector, preferably in the kitchen sector. These include baking machines, toasters, table top grills, kitchen machinery, electronic can openers and juicers. Preferred are switches, housings, handles and covers made from novel molding compositions in these products. The novel molding compositions can also be used for molded articles of stoves, preferably stove handles, stove handles and switches.

The use of the novel molding compositions has also proved to be successful in large surface area molded articles for their relatively thin and required good molding performance in terms of their surface area. Special large surface area moldings of this type include sunroof rails, external body parts, air inlet grilles, instrument panel parts, for example instrument panel supports, protective covers, air pipes, additional parts (especially for the central console as part of an armored compartment), and also Protective rug for tachometer.

Particular preference is given to the use of an overmolded structure according to the invention for the interior of a motor vehicle.

The following examples describe the invention in more detail.

Example 1

Over-injection technology

Foam skin layer

Substance: Pifiplex® 2567S from the P-group (Italy) (chemical composition: TCP-ET (ISO 1043))

Processing Parameters of Continuous Injection Molding for Foam Skin Layer:

Melting temperature about 230 ℃

Molding temperature about 70 ℃

Injection speed 80 mm / min

Clamp force 200 KN

No back pressure

Hard layer

Material: Ultradeur® S 4090 GX from BASF AG (68 wt% PBT, 17 wt% ASA, 15 wt% glass fiber)

Processing parameters for the hard layer:

Melting temperature about 270 ℃

Molding temperature about 70 ℃

Injection speed 30 mm / min

Clamp force 2500 KN

Back pressure 20 bar

Ultradeu® was injected into a round mold of about 300 mm in diameter and 2 mm of spacing between two faces. The mold was opened an additional 2 mm and Pififlex® was injected. An additional 3 mm was opened immediately after filling the mold. This caused the dissolved gas to form a foam. The final thickness of the foam layer was 5 mm.

The Pifiplex® layer was formed using dissolved N ₂ and Piviplex® of 0.6% by volume (indicating the volume of Pifiplex® in its entirety). In the barrel of the extruder, N ₂ was introduced into the Pififlex® material at a pressure of about 300 bar, and the temperature of the barrel was from 220 ° C to 260 ° C.

Example 2

The same processing parameters and polymer materials as in Example 1 were used, but a physical blowing agent and a chemical blowing agent were used together.

While the equivalent treatment conditions reported in Example 1 were maintained with reference to physical foaming, the Piviflex® material was a 1.5 weight percent sodium carbonate based additive Hydroserol (from P-group (Italy) as a chemical blowing agent) Dry blended with CF40E.

The overmolded structure thus produced had good soft hand. The adhesion between the layers was good.

The adhesion between the layers of conventional articles formed from SMA (styrene-maleic anhydride) / polyurethane foam reaches values of only about 10 N / cm, while the hard and soft layers of the articles obtained according to Examples 1 and 2 The adhesion between them reached a value of at least 20 N / cm.

In contrast to the polymer combinations in the state of the art, the article could be easily recycled without prior separation of different polymers because the described system contains only one material group.

The main advantage is the mechanical properties of the soft hand crushed and re-injected molded parts in which the original layer's elongation at break is in the range of about 80%.

According to the present invention, there is provided an injection molding method of a multilayer molded article having a fully reproducible structure, and an article obtained from a recycled material which is sufficiently excellent in mechanical properties such as elongation at break and impact resistance.

Claims (21)

a) injection molding a hard layer in a mold consisting of two sides, b) raising one side of the mold or changing one side of the mold to obtain a small gap of 3-4 mm between the hard layer and the side of the raised or changed mold, c) by injecting a foam skin layer into the gap formed in step b), A method of injection molding for the production of a fully reproducible multilayer article comprising i) a hard layer formed of a thermoplastic polymer and ii) a foamed skin layer formed of a thermoplastic polymer compatible with the hard layer material. a) injection molding a hard layer in a mold consisting of two sides, b) raising one side of the mold or changing one side of the mold to obtain a small gap of 3-4 mm between the hard layer and the side of the raised or changed mold, c) by injecting a foam skin layer into the gap formed in step b), i) a hard layer formed of a thermoplastic polymer and ii) a foam skin layer formed of a thermoplastic polymer compatible with the hard layer material, wherein the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foam skin layer are both polybutyl. An injection molding method for producing a fully regenerated multilayer article, comprising lene terephthalate. The method of claim 2, i) the hard layer comprises PP, PBT, SMA, SAN, ABS; Formed of ABS / AMSAN-, ABS / PC-, ABS / PA-, PBT / PET-, PBT / ASA or PPE / HIPS-blend, ii) The injection molding method wherein the foam skin layer is formed of TPC / PBT, TPO, TPU or PVC. The method of claim 2, i) the hard layer is formed of a fiber reinforced PBT / ASA blend, ii) an injection molding method wherein the foam skin layer is formed of TPC / PBT or TPU. The method of claim 1, i) the hard layer is formed of fiber reinforced PP, ii) an injection molding method wherein the foam skin layer is formed of TPC / PBT or TPU. The method of claim 1, i) the hard layer is formed of a fiber reinforced ABS / PA blend, ii) an injection molding method wherein the foam skin layer is formed of TPC / PBT or TPU. The injection molding method according to any one of claims 1 to 6, wherein the foam skin layer is formed by overmolding. The cavity according to any one of claims 1 to 6, wherein the cavity is injected to form the foam layer portion by injecting the first thermoplastic material in the presence of the blowing agent, and the second thermoplastic material is injected to form the skin layer portion in the absence of the blowing agent. Injection molding method for obtaining a foamed skin layer by injection. The foam skin layer according to any one of claims 1 to 8, which is compatible with the thermoplastic polymer of the hard layer and the thermoplastic polymer of the foam layer and is inserted into the mold after the hard layer is injected. Forming a surface of the foam layer is injected after the insertion of the in-mold decorative film layer. 10. The method according to any one of claims 1 to 4 and 7 to 9, wherein the hard layer is 45 to 100% by weight polybutylene terephthalate as component A1, 0 to 30% by weight polyethylene terephthalate as component A2, and A component B comprising from 0 to 25% by weight of an ASA copolymer. The method of claim 10 wherein the hard layer is 80-90% by weight polybutylene terephthalate as component A1, and A component B comprising from 10 to 15% by weight of an ASA copolymer. The method of claim 10 or 11, wherein component B is 75 to 99.9% by weight of C1-C10-alkyl acrylate as component B11, 0.1 to 10% by weight of at least one multifunctional monomer having at least two non-conjugated olefinic double bonds as component B12 and at least one as component B13 50 to 90 weight percent of the particulate graft base B1 prepared from 0 to 24.9 weight percent of other copolymerizable monomers, and 10 to 50 weight percent of graft B2 prepared from 50 to 29 weight percent vinylaromatic monomer as component B21 and 10 to 50 weight percent of acrylonitrile and / or methacrylonitrile as component B22 and grafted to the graft base B1. Method comprising a. The method of claim 12, wherein the hard layer is reinforced by 5 to 30% glass, carbon or thermoplastic fibers. The method according to any one of claims 1 to 13, wherein the layer thickness of the foam skin layer is 1 to 12 mm. The foamed skin layer-forming thermoplastic polymer of claim 1, wherein the foamed skin layer forming thermoplastic polymer has a plurality of long chain ester repeating units as the soft portion and a plurality of short chain ester repeating units as the hard portion, wherein the short chain unit is of the formula Wherein the long chain ester units are represented by the formulas (IIa) and / or (IIb). <Formula I> -O-D-O-CO-R-CO <Formula IIa> -O-G-O-CO-R-CO <Formula IIb> -O-D-O-CO-A-CO- Where D is a divalent radical having a molecular weight of less than about 250 remaining after removal of the hydroxyl group from the alkylene glycol, at least a portion of the alkylene glycol used is 1,4-butane-diol, R is a divalent radical having a molecular weight of less than about 300 remaining after removal of the carboxyl group from the dicarboxylic acid, at least a portion of the dicarboxylic acid used is terephthalic acid, G is a divalent radical having a molecular weight of about 250 to about 6,000 remaining after removal of the hydroxyl end groups from the long chain glycol, A is a divalent radical having 1 to 25 carbon atoms remaining after removal of the carboxyl group from an unsaturated or saturated long chain dicarboxylic acid, O is oxygen. i) a hard layer formed of a thermoplastic polymer and ii) a foamed skin layer formed of a thermoplastic polymer compatible with the material of the hard layer, wherein both the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foamed skin layer comprise polybutylene terephthalate, The hard layer comprises 45 to 100 weight percent polybutylene terephthalate as component A1, 0 to 30 weight percent polyethylene terephthalate as component A2, and 0 to 25 weight percent ASA copolymer as component B. article. i) a hard layer formed of a thermoplastic polymer and ii) a foamed skin layer formed of a thermoplastic polymer compatible with the material of the hard layer, wherein both the thermoplastic polymer forming the hard layer and the thermoplastic polymer forming the foamed skin layer comprise polybutylene terephthalate, The foamed skin layer forming thermoplastic polymer has a plurality of long chain ester repeat units as the soft portion, and a plurality of short chain ester repeat units as the hard portion, wherein the short chain unit is represented by the following formula (I), wherein the long chain ester unit is A fully reproducible multilayer article as represented by IIa and / or IIb. <Formula I> -O-D-O-CO-R-CO <Formula IIa> -O-G-O-CO-R-CO <Formula IIb> -O-D-O-CO-A-CO- Where D is a divalent radical having a molecular weight of less than about 250 remaining after removal of the hydroxyl group from the alkylene glycol, at least a portion of the alkylene glycol used is 1,4-butane-diol, R is a divalent radical having a molecular weight of less than about 300 remaining after removal of the carboxyl group from the dicarboxylic acid, at least a portion of the dicarboxylic acid used is terephthalic acid, G is a divalent radical having a molecular weight of about 250 to about 6,000 remaining after removal of the hydroxyl end groups from the long chain glycol, A is a divalent radical having 1 to 25 carbon atoms remaining after removal of the carboxyl group from an unsaturated or saturated long chain dicarboxylic acid, O is oxygen. 18. The hard layer according to claim 16 or 17, wherein the hard layer comprises 45 to 100% by weight polybutylene terephthalate as component A1, 0 to 30% by weight polyethylene terephthalate as component A2 and 0 to 25% by weight ASA copolymer as component B. %, Wherein the foamed skin layer-forming thermoplastic polymer has a plurality of long chain ester repeat units as the soft portion and a plurality of short chain ester repeat units as the hard portion, wherein the short chain unit is represented by the following formula (I) The unit is a fully reproducible multilayer article, represented by the formulas (IIa) and / or (IIb) below. <Formula I> -O-D-O-CO-R-CO <Formula IIa> -O-G-O-CO-R-CO <Formula IIb> -O-D-O-CO-A-CO- Where D is a divalent radical having a molecular weight of less than about 250 remaining after removal of the hydroxyl group from the alkylene glycol, at least a portion of the alkylene glycol used is 1,4-butane-diol, R is a divalent radical having a molecular weight of less than about 300 remaining after removal of the carboxyl group from the dicarboxylic acid, at least a portion of the dicarboxylic acid used is terephthalic acid, G is a divalent radical having a molecular weight of about 250 to about 6,000 remaining after removal of the hydroxyl end groups from the long chain glycol, A is a divalent radical having 1 to 25 carbon atoms remaining after removal of the carboxyl group from an unsaturated or saturated long chain dicarboxylic acid, O is oxygen. 19. Use of the article according to any one of claims 16 to 18 for the interior of a motor vehicle. Instrument panel according to claim 19. An automobile seat according to claim 19.