CA2044742A1

CA2044742A1 - Process for the production of molded articles or films

Info

Publication number: CA2044742A1
Application number: CA002044742A
Authority: CA
Inventors: Joachim Wagner; Werner Rasshofer; Thomas Elsner
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1990-06-21
Filing date: 1991-06-17
Publication date: 1991-12-22
Also published as: DE4019800A1; JPH04232729A; KR920000848A; EP0462474A2; EP0462474A3

Abstract

PROCESS FOR THE PRODUCTION OF MOLDED ARTICLES OR FILMS

ABSTRACT OF THE DISCLOSURE
The present invention is directed to a process for the production of molded articles or films, comprising thermoplastically shaping a combination under elevated temperature and pressure conditions wherein the combination contains foamed polyisocyanate polyaddition products in size reduced form and wherein the shaping process irreversibly increases the density of the foamed polyisocyanate polyaddition products.

Mo3576

Description

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Mo3576 - LeA 27,551 PROCESS FOR THE PRODUCTION OF MOLDED ARTICLES OR FILMS
`: BACKGROUND OFI HE INVENTIO~
The present invention relates to a process for the production of reinforced molded articles or films based on ~ 5 foamed polyisocyanate polyaddition products containing urethane -~ groups and/or urea groups by thermoplastic shaping. The polyisocyanate polyaddition products used are size reduced foamed materials in combination with certain reinforcing materials. The density of the foamed materials is increased in the course of thermoplastic shaping. The invention is also directed to the molded products thus obtained.
It is already known to produce molded articles or sheet products by thermoplastic shaping of polyurethanes (see e.g. Becker/Braun, Kunststoff-Handbuch, Volume 7, "Polyurethane", publishers Carl Hanser, Munich/Vienna (1983), pages 428 et seq). Thermoplastically processible polyurethane elastomers are generally based on diisocyanates, relatively high molecular weight dihydroxy compounds (in particular relatively high molecular weight polyester diols), and low molecular weight diols used as chain lengthening agents. Such polyurethanes should be as linear in structure as possible, i.e. they should have no cross-linking or branching points in the molecule.
Thermoplastic shaping of polyurethanes with a branched molecular structure is also known. Thus, fnr example, German Offenlegungsschriften 2,461,399, 2,164,381, 2,Q32,174 and 2,607,380 describe the preparation and thermoplastic shaping of polyurethane foams.
German Offenlegungsschrift 3,733,756 describes the production of molded articles or films based on polyisocyanate polyaddition products having densities of at least 0.8 g/cm3.
The polyisocyanate polyaddition products are elastomers which are prepared from isocyanate reactive compounds having 35376JaG2301 ., :`` 2~7~

molecular weights of from 1800 to 12,000 and having functionalities for the isocyanate addition reaction of at least 2.5 together with low molecular weight, preferably difunctional compounds containing isocyanate reactive groups as re~ctants for the polyisocyanates. The polyisocyanate polyaddition products which are to be thermoplastically ~ processed may also contain fillers and reinforcing materials.It was an object of the present invention to provide a process by which new molded articles with properties suitable for many applications could be produced from foamed - polyurethane parts such as waste, rejects, left-overs or old parts for the purpose of reusing these materials. It was in particular an object of the present invention to provide a process which would enable composite articles of so-called "back filled" foams and film materials such as polyvinyl chloride films of the kind used, for example, for dashboards in the construction of motor vehicles, to be re-used for the production of useful articles.
DESCRIPTION OF THE INVENTION
It has now surprisingly been found that high quality molded articles and sheet products based on polyisocyanate polyaddition products could be obtained by a process variation in which a foamed polyisocyanate polyaddition product having a particular chemical composition and present in a size reduced form could be combined with certain reinforcing materials, optionally in combination with a sheet product also present in size reduced form, whereupon thermoplastic shaping of this combination could be carried out with irreversible compression and increase in density. The "thermoplastic" shaping process according to the invention does not require melting of the polyisocyanate polyaddition product, which is a feature of "thermoplastic" polymers in the true sense, and at no stage does a liquid, relatively low viscous, macroscopic phase occur.
The term "thermoplastic shaping' as used herein means a shaping process which takes place at an elevated temperature and in Mo3576 20~47~2 which the polyisocyanate polyaddition product may be softened but is not liquefied.
The present invention relates to a process for the production of molded articles or films, comprising thermoplastically shaping a combination under elevated : temperature and pressure conditions wherein the combination contains foamed polyisocyanate polyaddition products in size reduced form and wherein the shaping process irreversibly increases the density of the foamed polyisocyanate polyaddition products. In a first embodiment, the combination comprises A) at least 20% by weight based upon the total weight of all the components of the combination of a component A) consisting of A1) foamed polyisocyanate polyaddition products present in a size reduced form and having a density of from 0.1 to 1.2 g/cm3 obtained by the reaction of a) organic polyisocyanates with b) compounds having molecular weights of from 1800 to 12,000 containing on statistical average at least 2.5 isocyanate reactive groups, c) optionally diamines having molecular weights of from 108 to 400 and having two primary and/or secondary aromatically bound amino groups, and d) optionally one or more compounds, which contain ether groups, having molecular weights of from 60 to 1,799, and being selected from the group consisting aliphatic diols, cycloaliphatic diols, aliphatic polyamines, and cycloaliphatic polyamines, in the presence of e) blowing agents and optionally other auxiliary agents and additives known from polyurethane chemistry by a single stage or multistage process in which an isocyanate index of from 62 to 200 is maintained, Mo3576 4 2 ~
; and B) up to 80% by weight, based on the total weight of all the components of the combination of fillers and/or reinforcing materials, and - 5 C) up to 50% by weight, based on the total weight of all the- components of other auxiliary agents and additives.
In a second embodiment, component A) of the mixture is A2) a mixture in a size reduced form of such foamed polyisocyanate polyaddition products (Al) and films of the kind used for back foaming a film to produce a foam-film composite, As used herein, the "combination" to be shaped can be a mixture such as when particulate fillers are used as component B) or can be a combination of a reinforcing structure (such as a mat) with the foam particles.
The invention also relates to the molded articles and films obtained by the process according to the invention.
Polyisocyanate polyaddition products Al) to be used in the process according to the invention are foamed synthetic resins having densities of from 0.1 to 1.2, preferably from 0.1 to 1.0, and most preferably from 0.1 to 0.79 g/cm3. These materials are most preferably very flexible to semi-rigid foams having a Shore D hardness of at most 50, preferably not more than 40. The foams may contain up to 80% by weight, preferably - 25 20 to 60% by weight, of fillers and/or reinforcing materials.
The polyisocyanate polyaddition products Al) are foams having a gross density amounting to at most gOY0, preferably not more than 50% of the density of the corresponding pore free material. The polyisocyanate polyaddition products Al) are produced by the reaction known per se of the above-mentioned starting materials. These materials may be reacted together in one or more stages and the reaction may be carried out either in closed molds or under conditions of free foaming of the starting materials.

Mo3576 A

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' The starting materials a) used may be any organic poly;socyanates but are preferably aromatic polyisocyanates, i for example the isocyanates described in European patent 81,701, column 3, line 30 to column 4, line 25. Polyisocyanat~
i ~ 5 mixtures of the diphenylmethane series obtainable in known manner by the phosgenation of aniline/formaldehyde condensates and having viscosities of from 50 to 500 mPa.s at 23C are particularly preferred as component a).
Component b) consists of isocyanate reactive compounds having molecular weights of from 1800 to 12,000, preferably from 3000 to 7000, or of mixtures of such compounds.
Component b) has an average functionality above 2.5 in isocyanate addition reactions. The average functionality of component b) is preferably from 2.5 to 3.0, and in particular from 2.8 to 3Ø Compounds particularly suitable for use as component b) are polyether polyols and mi~tures of polyether polyols conforming to these conditions as disclosed in German Auslegeschrift 2,622,951, column 6, line 65 to column 7, line 47. Polyether polyols in which at least 50% of the hydroxyl 20 groups, preferably no less than 80% of the hydroxyl groups consist of primary hydroxyl groups are also preferred for the present invention. Hydroxyl group-containing polyesters, polythioethers, polyacetals, polycarbonates and polyester - amides disclosed in German Auslegeschrift 2,622,951 are in 25 principle also suitable as components b) according to the invention, provided they conform to the above-mentioned conditions, but are less preferred than polyether polyols. The high molecular weight polyhydroxyl compounds containing polyadducts or polycondensates or polyether polyols modified by vi nyl polymers mentioned in German Auslegeschrift 2,622,951 may also advantageously be used as part or all of component b) if ; they conform to the conditions indicated above.
Polyether amines and mixtures of polyether amines conforming to the above-mentioned conditions, i.e. polyethers 35 containing isocyanate reactive groups consisting to an extent Mo3576 2 ~ L~

of at least 50 equivalents %, preferably not less than 80 equivalents %, of primary and/or secondary, aromatically or aliphatically, preferably aromatically bound amino groups, the rema;nder being composed of primary and/or secondary aliphatically bound hydroxyl groups, are also suitable as starting components b). Suitable amino polyethers of this type are, for example, the compounds described in European patent 81,701, column 4, line 26 to column 5, line 40. The amino groups in these compounds may also be present in an other suitable form, e.g. as ketimine groups.
Mixtures of the polyhydroxyl compounds exemplified above with the polyether amines exemplified may, of course, also be used as component b).
Component c) optionally used for the invention consists of aromatic diamines of the type described in European Patent 81,701, column 5, line 58 to column 6, line 34. Those diamines mentioned as preferred in this European patent are also preferred for the present invention.
The polyols and polyamines d) optionally used as additional starting components may contain ether groups and may be any non-aromatic compounds having molecular weights of from 60 to 1799, preferably from 62 to 500, most preferably from 62 to 400, containing two isocyanate reactive groups.
Other compounds which may be used as component d) include, for example, aliphatic polyamines containing ether groups, for example polypropylene oxides in the aboYe-mentioned molecular weight range containing terminal primary amino groups. Polyols containing cycloaliphatic rings may also be used, for example, ; 1,4-dihydroxy-cyclohexane or 1,4-bis-hydroxymethyl-cyclohexane.
It is important that in the preparation of the foams, component b) should be used in such a quantity that the proportion by weight of component b), based on the weight of components a) to d), is at least 5% by weight, preferably not less than 10% by weight. The polyisocyanate polyaddition products are most preferably prepared from polyols b) as the Mo3576 20~7~2 : -7-only reactants for the polyisocyanates. The average functionality of all the components b) to d~ for isocyanate addition reactions is preferably but not necessar~ly at least 2.5.
Since the polyisocyanate polyaddition products A1) are foams, it is essential to use known blowing agents e) for their preparation, optionally in addition to other auxiliary agents and additives e). Both chemical and physical blowing agents may be used, as well as inert gases dissolved in the starting components. Suitable blowing agents are described, for example, in European patent 81,701, column 8, lines 31 to 51, and in "Kunststoff-Handbuch" cited there. Water is a preferred blowing agent.
The preparation of the polyisocyanate polyaddition products A1) may be carried out in the presence of fillers and/or reinforcing materials e) which, if used at all, may be added in quantities of up to 80% by weight, in particular from 20 to 60% by weight, based on the weight of all the starting components a) to e). The use of fillers and reinforcing 20 materials is, however, not preferred in preparing the polyisocyanate polyaddition products herein.
Examples of suitable fillers and/or reinforcing materials include barium sulphate, kieselguhr, whiting, mica and especially glass fibers, liquid crystal fibers, glass 25 flakes, glass spheres and metal fibers and carbon fibers. The reinforcing materials e) which can be used in the production of ; the polyisocyanate polyaddition product are also understood to include sheet materials made of wood, solid, optionally reinforced, plastics or metal, optionally containing 30 perforations or apertures, of the kind used, for example, for the production of foam-covered control panels, consoles, vehicle roofs, or instrument panels or for the production of other interior coverings in the vehicle construction industry.
In the subsequent comminution of the polyisocyanate 35 polyaddition products containing such reinforcing materials e), Mo3576 2~7~

corresponding small fragments or minute particles are automatically obtained in which the reinforcing materials are present in a correspondingly comminuted form. Such small fragments or minute particles can be processed to form new molded articles by means of the process of the present invention. If such fillers and/or reinforcing materials are used, component B) must still be used in the amounts noted.
Other auxiliary agents and additives e) optionally used include, for example, the conventional catalysts for polyisocyanate polyaddition reactions, surface-active addit;ves, cell regulators, pigments, dyes, flame retardants, stabilizers, plasticizers and fungistatic and bacteriostatic substances such as those exemplified, for example, in European patent 81,701, column 6, line 40 to column 9, line 31.
The preparation of the polyisocyanate polyaddition products A1) may be carried out by several variations, as already indicated, but it is preferably carried out by the one-shot process in which polyisocyanate component a) is mixed with a mixture of components b), c), d) and e) in suitable mixing apparatus and the mixture is brought to reaction. It would in principle also be possible to react the polyisocyanate polyaddition products by a "modified one-shot process" in which the polyisocyanate component a) is reacted with part of the isocyanate reactive compounds to form isocyanate semi-prepolymers which are then reacted in a single stage with the mixture of the remaining components containing isocyanate reactive groups. The foams could in principle also be prepared by the classical prepolymer process. In all cases, the isocyanate index (number of NCO groups divided by the number of NC0-reactive groups multiplied by 100) is from 60 to 200, preferably from 80 to 180, most preferably from 95 to 140. The auxiliary agents and additives e) are generally incorporated with component b) or with the mixture of components b)-d) before these are mixed with the polyisocyanate component a) although certain auxiliary agents and additives could be added Mo3576 7 ~ ~
g to the polyisocyanate component before the latter is combined with the other starting materials. When the polyisocyanate polyaddition products are prepared by the prepolymer process, the auxiliary agents and additives are preferably added to the isocyanate prepolymers.
Preparation of the polyisocyanate polyaddition products Al) may be carried out in closed molds by the reaction injection molding technique as described, for example, in German Auslegeschrift 2,622,951, U.S. Patent 4,218,543 or European Patent 81,701 but they may also be prepared in open molds or foamed in the open as blocks or foam boards.
Component A) most preferably consists of combinations A2) in a size reduced form of foamed polyisocyanate polyaddition products of the type mentioned above and thermoplastic films such as back foamed composite systems. The term "back foamed composite systems" is used here to denote composite systems of thermoplastic films and flexible polyurethane foams such as those used, for example, for the manufacture of steering wheels, head rests, dashboards, bicycle saddles, the inside linings of motor vehicle roofs, and the like. Soft polyvinyl chloride films are examples of suitable thermoplastic films but any other thermoplastic films may also be used, for example films produced by the so-called slush process, by deep drawing or from suitable starting materials in closed film molds. The last mentioned include, for example, polyurethane films produced in closed molds, preferably without blowing agents, from starting materials substantially similar to the starting materials a) to d) of the polyisocyanate pulyaddition products used according to the invention. The "thermoplastic films" may be either films based on conventional thermoplastic synthetic resins, i.e. polymers which are liquefied in the process of thermoplastic shaping, or films based on synthetic resins of the type of polyisocyanate polyaddition products used according to the invention, which are not liquefied in the process of thermoplastic shaping and Mo3576 2~7~2 for which the term "thermoplastic" has the meaning indicated above.
The composite systems A2) are produced in known manner by lining suitable molds with a thermoplastic film of the type mentioned above and then filling the lined mold with the reaction mixture which is to react to form ~ foam. Such composite systems generally consist of 40 to 70% by weight of thermoplastic film and 30 to 60% by weight of polyurethane foam.
When the process according to the invention is carried out with composite sys$em A2) as component A), it serves in particular for the re-use of such composite systems which are obtained, for example, from the scrapping of old motor vehicles or vehicles which have become write-offs in accidents or as waste products from the production and processing of such composite systems.
When foamed polyisocyanate polyaddition products Al) are used as component A), the process according to the invention is employed, for example, for the re-use of production waste such as sprues, flash or surplus which is cut off in the manufacture of block foams.
It is important, however, that the pol~isocyanate polyaddition products Al) or their combinations A2) with thermoplastic films should be used in a size reduced form, i.e.
in the form of granules, shavings, flakes and/or other small and very small particles. It is particularly preferred to size reduce the polyisocyanate polyaddition products Al) or combinations A2) thereof with thermoplastic films to small or very small particle sizes of at most 10 mm, preferably less than 6 mm, in suitable apparatus before the process according to the invention is carried out. Suitable methods for size reduction include e.g. cutting, tearing, chopping and granulating, which are well known in the art. Suitable - apparatus for size reduction are available commercially.
Cutting m;lls with rotary knives, for example, used in Mo3576 2~7l~'~

conjunction w;th sie~es in which the milled material ~s screened are su~table apparatus for this purpose. Apparatus of this type are available e.g. from Pallmann, 6660 Zweibr~cken, BRD or from Weiss, 6340 Dillenburg, BRD.
- 5 Component B) consists of reinfurcing materials or fillers such as barium sulphate, kieselguhr, whiting, mica or in particular glass fibers, liquid crystal fibers, glass flakes, glass spheres and metal or carbon fibers. The reinforcing materials used as component B) are, however, most preferably sheet products such as mats of various weights per unit area, knitted or circular knitted fabrics, woven fabrics, non-wovens, nets, sieves, grids, etc. of glass, carbon fibers, liquid crystal fibers and fibers of polyamide, aramide, cellulose, and the like as well as of inorganic materials such as carbides or metals such as aluminum, steel or copper.
; Component B) is generally used in a quantity of up to 80% by weight in the process according to the invention, preferably 20 to 70% by weight, based on the total weight of all the components of the mixture to be thermoplastically shaped.
For carrying out the process according to the invention, starting component A) is combined with component B) optionally with auxiliary agents and additives C) in a quantity of up to 50% by weight, based on the total weight of all the components, preferably forming a multi-layer system. In the case of the preferred embodiment where component B) is in sheet or mat form, component A) is placed on such sheet or mat to form a laminated-like structure which is then thermoplastically shaped.
The optionally used auxiliary agents and additives C) may consist, for example, of other thermoplastic synthetic resins, such as polyethylene, polypropylene, polystyrene, ABS, thermoplastic polyurethane, polyacrylonitrile, PVC, polyvinyl acetate or mixtures of such thermoplastic resins. These Mo3576 2~7'~2 thermoplastic resins may be used in the form of films, mats, granulates, powders or any other form.
Other auxiliary agents and additives C) optionally used may include processing auxiliaries for improving the adherence between individual layers of the construction. Such processing auxiliaries are described, for example, in German Offenlegungsschrift 3,840,167.
The process according to the invention, i.e. the thermoplastic shaping of the combination of materials by the action of pressure and temperature, may be carried out in any known apparatus suitable for this purpose, such as deep drawing presses. The process according to the invention, however, does not include melting of the material such as takes place when ; processing true "thermoplastic" synthetic res~ns. A liquid, relatively low viscosity macroscopic phase does not occur at any stage. Suitable processes for thermoforming are described, for example, by H. Kaufer in "Maschinenmarkt" 88 (1982), Vogel-Verlag, Wurzburg, pages 1068 to 1071.
The process according to the invention is generally 20 carried out at a pressure of at least 1 bar (normal pressure), preferably within the pressure range of from 10 to 400 bar, most preferably within the pressure range of from 20 to 100 bar, at a temperature of at least 50C, preferably from 100 to 220C, most preferably at 150 to 200~C. The shaping times may 25 vary from 1 second to 10 minutes.
The pressure and temperature conditions and their duration must be chosen so tha~ the foamable polyisocyanate polyaddition products of component AJ are compressed during the action of pressure and temperature so that the density of the polyisocyanate polyaddition products present in a compressed form in the products of the process is at least lO~o~ preferably at le~st 50% above the density of the polyisocyanate poly-addition products A) used as starting materials.
The process according to the invention may be used for the production of semi-finished goods as well as the Mo3576 2~7~, production of end products from waste material and for the recycling of used parts for a wide variety of purposes. Thus the composite bodies according to the invention may be used, for example, in the form of hollow bodies for linings, cups and containers of various dimensions and volumetric capacities, as covers for dashboards and switch boards, as covers for steering !: columns, for flat parts of car bodies such as door panels, side parts, mudguards, bonnets or the lids of luggage compartments and for the manufacture of wheel caps, seating shells or back rests. In a flat form, the products of the process according to the invention are also suitable for use as writing surfaces, ; display boards with magnetic holders, adhesive labels and sign plates, and protective films and coatings for various purposes.
The products of the process according to the invention may also be used as seating shells, back rests, cushions, cups, luggage of a stressed skin construction and similar containers, construction parts for car bodies, chassis, stiffening elements, profiles such as frames, carriers, rigid external parts of car bodies such as mudguards or engine bonnets or lids 20 of luggage compartments, wheel caps, wheel case linings, stiffening elements for shutters, interior door trimmings for motor vehicles, doors, flaps, covers and similar articles.
- They may also be pressed together with wood and the like and . used in the interior of vehicles. They are also suitable for 25 articles manufactured for the recreation industry.
Products of the process according to the invention may also be used in the form of small molded parts such as keyboard elements, rigid elastic sealing parts and collars, handles and hollow parts for grips, small damping elements and washers and spacer discs. They may also be used for rigid or non-rigid profiles for cable channels and sealing lips or for any other solid, small parts.
The invention is further illustrated but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
Mo3576 2~7~

EXAMPLES
A film-foam composite prepared as described below was used in the Examples. The following polyurethane raw materials were used for back foaming:
90 parts of a polyether of molecular weight 4800 (obtained by the addition of propylene oxide (87%) and ethylene oxide (13%) to trimethylolpropane), 2.5 parts of water, 2 parts ~f tall oil and 0.4 parts of dimethylaminopropyl-formamide were : mixed with 47 parts of a polyphenyl polymethylene polyisocyanate which had been obtained by the phosgenation of an aniline-formaldehyde condensate and which had an isocyanate content of 31% by weight.
A commercial polyvinyl chloride product about 0.7 mm in thickness which has not been colored was placed in a heatable metal plate mold measuring 20 x 20 x 4 cm. The sheet was back-filled mechanically with the mixture described above.
The product was removed from the mold after a reaction and curing time of 5 minutes.
The molded parts obtained were tempered in a circulating air drying cupboard at 120C. The density of the back filling foam was about 0.45 g/cm3.
The composite material thus produced was first subjected to a preliminary size reduction to pieces measuring about 3 cm to 5 cm and then size reduced to a particle size of about 4 mm in a cutter mill PS 4-5 (Pallmann, Zweibrucken, BRD).
This granulate was used as starting material for the Examples which follow.
Example 1 The granulate was preheated to 180C for 10 minutes in a drying cupboard and then introduced together with an endless fiber glass mat U 816 (Gevetex, Herzogenrath, BRD) into a shear edge tool (pressure mold for the production of a pressed plate measuring 60 x 120 mm and varying in thickness of from 0.5 to 5 mm according to the amount of filling; the mold Mo3576 . .

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is made of brass with a brass ram) which was situated in the press and had been preheated to 195-C. The weight of the glass mat amounted to 60% of the total weight of the materlal introduced into the pressure mold.
After the mold (Model Polystat 200 T of Schwabenthan, Berlin) had been filled, the press was closed and the mold subjected to a compression pressure of 80 bar. After a molding pressure time of 2 minutes, the plate which had a thickness of 3 mm was removed. The thickness of 3 mm obtained corresponded to an irreversible compression of the foam in the press to twice the original density (0.9 g/cm3).
The plate showed signs of separation of the PVC-PUR
fractions, but this had no influence on the mechanical properties of the plate.
Tension rods produced from this plate showed an elongation at break according to DIN 53 504 of 3% and a tensile strength of 14 MPa.
Example 2 The same procedure as used in Example 1 was followed, but instead of the glass mat, a wire mesh with a width of mesh of 0.1 mm in a quantity of 60% by weight, based on the total weight of the material in the press, was used.
A pressed plate 1.2 mm in thickness was obtained.
This could be bent like a metal plate at room temperature with permanent deformation. Th;s thickness corresponds to a compression of the foam material in the mold to twice its density (0.9 g/cm3).
Example 3 The same process as in Example 2 was used, but using a wire mesh with a mesh width of 0.3 mm. The result is substantially similar to that of Example 2.
Example 4 The granulate used in Example 1 is placed together with a continuous filament glass mat U 816 covered by a layer of fine wood veneer on to a pressed plate preheated to 170~C to Mo3576 204~7~2 form a 4-layered struc~ure (PVC/PUR-endless filament glass mat-PVC/PUR wood veneer).
The granulate was not preheated before it was placed ; on the pressed plates which had been preheated to 170-C. It s was then covered with the endless filament mat on which more granulate was placed and the wood veneer was placed on top.
The press was then slowly closed and the material was subjected to a pressure of 100 bar between the plates. After 2 minutes, the material was cooled to room temperature under pressure within a period of 4 minutes and the laminate was removed. The proportion by weight of the endless mat was 50%, based on the total weight of the laminate. The quantity of granulate used amounted to 45% of the total weight. The amount by which the foam was compressed in the course of production of the laminate corresponded to a doubling in the density of the foam material (0-9 9/cm3).
Example 5 Plates containing endless filament glass mats as reinforcement were produced in a shear edge tool (tool for the production of pressed plates measuring 190 x 190 mm) by a process analogous to that of Example 1, using a Polystat 400 press of Schwabenthan, Berlin, BRD. Three endless filament glass mats were placed in the mold which was then filled with the amount of granulate required for a glass content of 70% by weight in the plates produced.
The temperature of the press was 198C and the compression pressure 180 bar in the molded part and the dwell time of the material in the press was varied from 10 to 20 minutes. The pressed plates were removed from the mold while hot. Six boards were produced by this method.
Example 6 The plates from Example 5 were converted into pyramidal molded parts by a deep drawing process in another, separate step.

Mo3576 ..

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-, .. ~ -20~7~2 FO~^ this purpose, the semi-finished plates from Example 5 were preheated at 180-C in a drying cupboard for 10 minutes and then placed into the compression mold (asymmetric pyramidal mold with a height of 4 cm and a square base with a length of side of g.~ cm, made of brass) which had been preheated to 194-C. The press was then slowly closed and the molded part inside the press was subjected to a pressure of 80 bar. After a dwell time of 2 minutes, the molded part was cooled to room temperature under pressure and removed from the mold Although the inventiun has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.

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Mo3576

Claims

1. A process for the production of molded articles or films, comprising thermoplastically shaping a combination under elevated temperature and pressure conditions wherein the combination contains foamed polyisocyanate polyaddition products in size reduced form and wherein the shaping process irreversibly increases the density of the foamed polyisocyanate polyaddition products, wherein said combination comprises A) at least 20% by weight based upon the total weight of all the components of the combination of a component A) comprising Al) foamed polyisocyanate polyaddition products present in a size reduced form and having a density of from 0.1 to 1.2 g/cm3 obtained by the reaction of a) organic polyisocyanates with b) compounds having molecular weights of from 1800 to 12,000 containing on statistical average at least 2.5 isocyanate reactive groups, c) optionally diamines having molecular weights of from 108 to 400 and having two primary and/or secondary aromatically bound amino groups, and d) optionally one or more compounds, which contain ether groups, having molecular weights of from 60 to 1,799, and being selected from the group consisting aliphatic diols, cycloaliphatic diols, aliphatic polyamines, and cycloaliphatic polyamines, in the presence of e) blowing agents and optionally other auxiliary agents and additives known from polyurethane chemistry by a single stage or multistage process in which an isocyanate index of from 62 to 200 is maintained, and Mo3576 B) up to 80% by weight, based on the total weight of all the components of the combination of fillers and/or reinforcing materials, and C) up to 50% by weight, based on the total weight of all the components of other auxiliary agents and additives.

2. The process of Claim 1 wherein component A) of the combination is A2) a mixture in a size reduced form of such foamed polyisocyanate polyaddition products (Al) and films of the kind used for back foaming a film to produce a foam-film composite,

3. The process of Claim 1, wherein the polyisocyanate polyaddition products of component A) have a density of from 0.1 to 0.79 g/cm3.

4. The process of Claim 1, wherein said component A) is present in the form of granulates, shavings, flakes and/or other small and very small particles before they are combined with component B) to form the combination which is to be subjected to the thermoplastic shaping process.

5. A molded article or film produced according to the process of Claim 1.

Mo3576