EP4263679A1

EP4263679A1 - Process for producing a thermoplastic polymer-containing fiber-reinforced composite material

Info

Publication number: EP4263679A1
Application number: EP21831317.9A
Authority: EP
Inventors: Felix KLAUCK; Pierre JUAN; Norbert Niessner; Jonathan LIMBECK; Eike Jahnke
Original assignee: Ineos Styrolution Group GmbH
Current assignee: Ineos Styrolution Group GmbH
Priority date: 2020-12-16
Filing date: 2021-12-14
Publication date: 2023-10-25
Also published as: WO2022129045A1; US20240141116A1

Abstract

The invention relates to a process for producing a fiber-reinforced composite material (organosheet) containing at least one thermoplastic molding compound, at least one continuous reinforcing fiber layer and at least one inorganic filler material. According to the invention, at least one sheet material consisting of continuous reinforcing fibers is embedded in a matrix composition comprising at least one thermoplastic molding compound, the thermoplastic molding compound including at least one thermoplastic polymer and optionally at least one polarity-functionalized polymer that contains repeat units of at least one functional monomer. The invention also relates to the composite materials produced according to the claimed method.

Description

Process for producing a fiber-reinforced composite material containing a thermoplastic polymer

The invention relates to a method for producing a fiber-reinforced composite material (organic sheet) which comprises at least one thermoplastic molding compound, at least one layer of continuous reinforcing fibers and at least one inorganic filler. In particular, at least one fabric consisting of reinforcing fibers is embedded in a matrix composition which comprises at least one thermoplastic molding composition, the thermoplastic molding composition containing at least one thermoplastic polymer and optionally at least one polar functionalized polymer which comprises repeating units of at least one functional monomer. The invention also relates to the composite materials produced according to the method described here.

State of the art

Composite materials or organo sheets usually consist of a large number of reinforcing fibers that are embedded in a polymer matrix. The areas of application of composite materials are diverse. For example, composite materials are used in the automotive and aviation sectors. The aim here is to prevent tearing or other fragmentation of the component through the use of composite materials, in order to reduce the risk of accidents caused by individual component fragments. Many composite materials are able to absorb comparatively high forces under load before total failure occurs. A total failure of fibre-reinforced composite materials is expressed by the fact that components do not burst into many individual parts when the maximum bending stress is exceeded, for example when subjected to bending stress, but remain connected via the reinforcing fibers with individual fractures or biting points. At the same time, composite materials are distinguished from conventional, non-reinforced materials by a high strength and rigidity that can be adjusted depending on the direction, while at the same time having a low density and other advantageous properties, such as good resistance to aging and corrosion.

The strength and stiffness of the composites can be adjusted to the direction and type of loading. The fibers are primarily responsible for the strength and rigidity of the composite material. In addition, their arrangement often determines the direction-dependent, mechanical properties of the respective composite material. The primary purpose of the matrix is to introduce the forces to be absorbed into the individual fibers and to maintain the spatial arrangement of the fibers in the desired orientation. Furthermore, the matrix protects the fiber from external influences and determines the long-term properties of the composite material. Above all, however, the choice of matrix material largely determines the external appearance of the composite material.

In the production of composite materials, the connection of fibers and polymer matrix to each other and the critical fiber length play an important role. The strength of the embedding of the fibers in the polymer matrix (fiber-matrix adhesion) can also have a significant influence on the properties of the composite material. In addition, the process for producing the materials should be simple and inexpensive to carry out.

Since both the fibers and the matrix materials can be varied, there are numerous possible combinations of fibers and matrix materials. Due to the low chemical similarity between the fiber surface and the surrounding polymer matrix, there is often a low attraction and thus a low adhesion between fibers and matrix materials.

In order to optimize the fiber-matrix adhesion and to compensate for the low chemical similarity between the components, reinforcing fibers are regularly pre-treated with a so-called sizing (sizing agent). Such a sizing (sizing agent) is often applied to the fiber during production in order to improve the further processing of the fibers (such as weaving, laying, sewing) at the same time. In some cases, reinforcing fibres, such as glass fibres, are also processed without a size. These glass fiber sizings often contain a large number of different components, such as film formers, lubricants, wetting agents and adhesion promoters.

The treatment of reinforcing fibers with a sizing serves, among other things, to prevent the fibers from being damaged by abrasion or to facilitate the cutting process of the fibers. Furthermore, the sizing can avoid agglomeration of the fibers and the dispersibility of fibers in water can be improved. However, a size can also contribute to the production of improved cohesion between the glass fibers and the polymer matrix in which the glass fibers act as reinforcing fibers. This principle is mainly used in glass fiber reinforced composites. Typically, coupling agents in the size can increase the adhesion of polymers to the fiber surface by forming a bridging layer between both surfaces. Organofunctional silanes such as aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, glycidyloxypropyltrimethoxysilane and the like are often used.

A technical challenge is to avoid material breakage in the event of total failure of the fiber-reinforced composite materials, as this can result in a significant risk of accidents due to torn components. This is problematic, for example, in the case of components that are exposed to high loads.

It is therefore desirable to provide composite materials with a low intrinsic weight and a wide load range in which the total failure does not manifest itself in the form of a material fracture. Composite materials with excellent optical properties, such as smooth and/or shiny surfaces, are also desirable. In order to obtain an aesthetically high-quality surface, especially in composites with a thermoplastic matrix, it is crucial to achieve a reduction in the shrinkage of the thermoplastic matrix, e.g. during cooling after the composite has been manufactured.

WO 2008/058971 describes molding compositions which use different groups of reinforcing fibers. The groups of reinforcing fibers are each provided with different adhesion promoter components, which are intended to bring about different fiber-matrix adhesions. Thermosets, such as polyester, and thermoplastics, such as polyamide and polypropylene, are proposed as matrix materials. The aim of the application is to achieve improved fracture-mechanical behavior in the event of total failure.

WO 2010/074120 describes a fiber-reinforced polypropylene resin composition containing a reinforcing fiber, a largely unmodified polypropylene resin and two other polypropylene resins, comprising a carboxy-modified polypropylene Resin, where the molecular weight of the various polypropylene resins is defined. The aim here is to achieve the best possible fiber-matrix adhesion in order to optimize the mechanical properties of the composite material. In the application, this is achieved by adjusting the ratios of the two functional monomers.

WO 2019/086431 describes a fiber-reinforced composition characterized in that it contains a filler which remains in an outer area of the fiber bundles and thus reduces the shrinkage of the matrix. The resin composition can be found both in the outer area with the fillers and in the inner area of the fiber bundles.

Glass fiber reinforced polypropylene resins are also e.g. 154791, CN-A 107 815013, CN-A 107118437, WO 2019/010672 and CN-A 108164822.

WO 2008/119678 discloses thermoplastic molding compositions containing 5 to 95% of a copolymer A consisting of: 70-76% vinyl aromatic monomer A1, 24-30% vinyl cyanide monomer component A2 and 0-50% of one or more unsaturated, co- polymerizable monomers A3; 0-60% of a graft rubber B and 5-50% glass fibers C. The molding compositions are produced by mixing the components and processed using the injection molding process.

The production of fiber-reinforced composites includes the following process steps, whereby the order of the process steps can vary from time to time:

(i) providing a) at least one thermoplastic molding composition A, b) at least one layer of reinforcing fibers B, and c) optionally at least one additive C,

(ii) contacting components A and B, and optionally C,

(iii) impregnating and consolidating components A and B, and optionally C;

(iv) optionally shaping the fiber composite material obtained from the previous steps; and

(v) optionally allowing the fiber composite material obtained from the previous steps to harden. The production of fiber composite materials according to this general process principle is z. in WO 2016/170145, WO 2016/170148, WO 2016/170131, WO 2016/170098, WO 2016/170104 and DE 20 2017004083 U1.

In addition, production processes are also known in which short fiber-reinforced composite materials are obtained, for example, by mixing and compounding processes and can be further processed, e.g. in injection molding processes. Examples are described in EP 3394171, EP 0945253 and WO 2018/114979.

DE 10 2017125438 describes a fiber-reinforced composite material comprising a fiber material which has a plurality of continuous fibers each formed from filaments, a plastic matrix material which fills an inner space between the filaments of a respective continuous fiber and surrounds the continuous fibers in an outer space, and a quantity of particles. The particles preferably include glass particles, in particular hollow glass bodies, and/or carbon particles and/or mineral particles and/or ceramic particles and/or temperature- and/or pressure-expanded particles.

The composite material is obtained by a process comprising the steps of:

providing a fibrous material having a plurality of continuous fibers each formed of filaments;

providing a plastic matrix material and a quantity of particles; adding the matrix material and the particles to the fiber material; and subsequently subjecting the fiber material, the matrix material and the particles to an external pressure; wherein the matrix material and the particles separate during the addition and/or the pressurization in such a way that a first volume concentration of the particles based on the matrix material in an inner spatial region between the filaments of a continuous fiber is less than a second volume concentration of the particles based on the matrix material in a outer space outside the filaments becomes.

WO 2019/086431 discloses a fiber-reinforced composite material comprising a fiber material which has a plurality of continuous fibers each formed from filaments, a plastic matrix material which has an inner space between the filaments of a respective continuous filament and surrounds the continuous filaments in an outer space region, and a quantity of particles.

The particles are selected from or consist of glass particles, in particular hollow glass bodies, and/or carbon particles and/or mineral particles and/or ceramic particles. A first volume concentration of the particles in relation to the matrix material in the inner spatial area is lower than a second volume concentration of the particles in relation to the matrix material in the outer spatial area, the second volume concentration being homogeneous and the second volume concentration in the outer spatial area being similar to one on the matrix material related volume concentration of the filaments in the inner space is adapted that temperature-dependent material properties of the composite material in the outer space and in the inner space adjust. The first volume concentration and the second volume concentration are preferably chosen such that a temperature-specific expansion coefficient of the composite material in the inner spatial area deviates by at most 15% from a temperature-specific expansion coefficient of the composite material in the outer spatial area.

The fiber-reinforced composite material described in WO 2019/086431 is obtained by a process with the following steps:

providing a plastic matrix material and a quantity of particles; adding the matrix material and the particles to the fiber material; and subsequently subjecting the fiber material, the matrix material and the particles to an external pressure; wherein the matrix material and the particles separate during the addition and/or the pressurization in such a way that a first volume concentration of the particles based on the matrix material in an inner spatial region between the filaments of a continuous fiber is less than a second volume concentration of the particles based on the matrix material in a outer spatial area outside of the filaments, with the second volume concentration becoming homogeneous, with the second volume concentration in the outer spatial area being adapted to a volume concentration of the filaments in the inner spatial area based on the matrix material in such a way that temperature-dependent material properties of the composite material in the outer spatial area and in the inner spatial area adjust. An object of the invention is to provide a method for producing a fiber-reinforced composite material based on a thermoplastic polymer which has good strength and high surface quality (ie low surface waviness), as well as resistance to stress cracking and solvents. In addition, the composite material should be suitable for the production of moldings, films and coatings. The manufacturing process should allow the composite material to be manufactured cost-effectively and be able to be integrated into common processes with the shortest possible cycle times.

A fiber-reinforced composite material with the desired properties can be obtained by introducing a filler into a thermoplastic matrix polymer and impregnating the textile fibers to compensate for shrinkage and significantly reduce the measured surface waviness of the resulting fiber-reinforced composite material. Surprisingly, an improved manufacturing process for such a thermoplastic, fiber-reinforced composite material was found. If both the thermoplastic molding compound and the filler are added in the form of powder during production, buildup on the pressing tool forms in conventional manufacturing processes, which can affect the service life of the pressing tool. By introducing the thermoplastic molding compound and the filler in the form of a thermoplastic film, adhesions on the pressing tool can be completely avoided.

The present invention relates to a process for producing a fiber-reinforced, thermoplastic composite material V, comprising: a) at least one thermoplastic matrix composition M, comprising at least one thermoplastic molding composition A, at least one particulate, inorganic filler and optionally at least one additive D; and b) at least one continuous reinforcement fiber B; the method comprising at least the following method steps: i) providing the at least one continuous reinforcing fiber B; ii) providing at least one thermoplastic matrix composition M obtained by mixing the at least one thermoplastic molding composition A, the at least one particulate, inorganic filler C and optionally the at least one additive D; iii) combining the thermoplastic matrix composition M with the at least one continuous reinforcing fiber B; iv) impregnation of the at least one continuous reinforcing fiber B with the thermoplastic matrix composition M to obtain a composite material V; v) consolidation of the composite V obtained; vi) optional solidification and/or optional further process steps; wherein in process step iii) the thermoplastic matrix composition M containing filler C is combined in the form of a thermoplastic film with the at least one continuous reinforcing fiber B, the thermoplastic matrix composition M being 20 to 80% by volume, preferably 20 to 70% by volume , in particular 30 to 60% by volume, of which at least one particulate, inorganic filler C consists.

In a preferred embodiment of the invention, the thermoplastic film used in process step iii) is characterized in that it has an average thickness of 25 to 500 μm.

The particulate, inorganic filler C preferably has a thermal expansion coefficient in the range from 2*1 0' ⁶ K' ¹ to 20*1 0' ⁶ K' ¹ .

The process for producing the fiber-reinforced, thermoplastic composite material V is preferably characterized in that process step iii) is carried out at a temperature of at least 160.degree. C., preferably at a temperature of from 160 to 280.degree.

Process step iv) of the process according to the invention is preferably carried out at a temperature of at least 180°C, more preferably at a temperature of 200-290°C, and/or at an elevated pressure in the range from 1 to 3 MPa.

The thermoplastic matrix composition M comprises at least one thermoplastic molding material A, which contains at least one thermoplastic polymer A1, particularly preferably a polyolefin A1. The thermoplastic matrix composition preferably comprises M > 5 to < 20 parts by weight, preferably > 10 to < 20 parts by weight, of the thermoplastic molding composition A, >1 to <60 parts by weight, preferably >5 to <40 parts by weight, of the at least one inorganic filler C, and >0 to <10 parts by weight of the at least one additive D.

The method according to the invention can advantageously be used to produce a fiber-reinforced, thermoplastic composite material V, the fiber-reinforced, thermoplastic composite material V comprising or consisting of the following components: a) >5 to <20% by weight of a thermoplastic molding composition A; b) >20 to <80% by weight of the at least one reinforcing fiber B; c)> 1 to <60 wt .-% of at least one particulate, inorganic filler C, and c)> 0 to <10 wt .-% of at least one other additive D, the details in wt .-% in each case on the are based on the entire fiber-reinforced, thermoplastic composite material V and the sum of components A, B, C and D is 100% by weight.

The polar functionalized polymer A2 is preferably a graft copolymer of polypropene and maleic anhydride, in particular with a maleic anhydride content of 0.1 to 5% by weight, based on the total weight of the polar functionalized polymer A2.

The thermoplastic molding composition A used in the process for producing a fiber-reinforced, thermoplastic composite material V preferably comprises at least one thermoplastic polymer A1 and optionally at least one polar functionalized polymer A2, comprising at least repeating units of at least one functional monomer A2-I.

In a preferred embodiment, the thermoplastic molding compound A comprises (or consists of) the following components: a-1) 50 to 99.9% by weight, preferably 70 to 99.9% by weight, particularly preferably 79 to 98% by weight %, particularly preferably 90 to 97% by weight, of a thermoplastic polymer A1; a-2) 0.1 to 20% by weight, preferably 0.1 to 10% by weight, particularly preferably 1 to 8% by weight, particularly preferably 3 to 7% by weight, of the at least one polar functionalized polymer A2; a-3) 0 to 49.9% by weight, preferably 0 to 29.9% by weight, more preferably 1 to 20% by weight, of at least one further polymer A3; where the polymers A1, A2 and A3 are different from one another, and where the percentages by weight are in each case based on the total weight of the thermoplastic molding composition A and the sum of the components A1, A2 and A3 is 100% by weight. The thermoplastic molding composition preferably consists of components A1, A2 and A3.

The particulate, inorganic filler C preferably has a density of 0.2-2.8 g/ml and an average particle size of less than 70 μm.

In a particularly preferred embodiment of the invention, the at least one particulate, inorganic filler comprises hollow glass spheres and/or calcium carbonate.

The thermoplastic matrix composition M preferably comprises at least one mold release agent as additive D.

The invention also relates to a fiber-reinforced, thermoplastic composite material V obtained by the process according to the invention.

The individual process steps for producing the composite material V and the components A, B, C, D and M used are explained in more detail below.

Process for the production of the fiber-reinforced composite material V

The invention relates to a method for producing a fiber-reinforced, thermoplastic composite material V, comprising: a) at least one thermoplastic matrix composition M, comprising at least one thermoplastic molding composition A, at least one particulate, inorganic filler C and optionally at least one additive D; and b) at least one continuous reinforcement fiber B. The method according to the invention is characterized by the following method steps: i) providing the at least one continuous reinforcing fiber B; ii) providing at least one thermoplastic matrix composition M obtained by mixing the at least one thermoplastic molding composition A, the at least one particulate, inorganic filler C and optionally the at least one additive D; iii) combining the thermoplastic matrix composition M with the at least one continuous reinforcing fiber B; iv) impregnation of the at least one continuous reinforcing fiber B with the thermoplastic matrix composition M to obtain a composite material V; v) consolidation of the composite V obtained; vi) optional solidification and/or optional further process steps;

The method is further characterized in that in method step iii) the thermoplastic matrix composition M containing filler C is combined in the form of a thermoplastic film with the at least one continuous reinforcing fiber B, the thermoplastic matrix composition M being 20 to 80% by volume, preferably 20 to 70% by volume, in particular 30 to 60% by volume, of which at least one particulate, inorganic filler C consists.

According to process step (i), the continuous reinforcing fiber B is preferably provided in the form of a flat structure, in particular a flat structure G. This is preferably provided flat, in its full surface area. Preferably, the surface filaments F described herein, such as woven fabrics, mats, fleeces, scrims or knitted fabrics, comprising the continuous reinforcing fibers B are used. More preferably, woven fabrics or scrims, in particular woven fabrics, which comprise the continuous reinforcing fibers B or consist of them, are used. The sheet G has a first and a second surface.

In process step ii), a thermoplastic matrix composition M is provided, which comprises at least one thermoplastic molding composition A, at least one particulate, inorganic filler C and optionally at least one additive D. The thermoplastic molding composition A, the particulate, inorganic filler C and the additive D are explained in more detail hereinbelow. The thermoplastic matrix composition M is obtained by intensively mixing components A, C and optionally D with one another. This can be done using any method known to those skilled in the art which is suitable for producing a homogeneous, thermoplastic composition. Components A, C and optionally D are usually provided as powders or granules. To produce the matrix composition M, the component A, comprising the polymers A1 and optionally A2 and/or A3, the component C and optionally the component D, in particular by joint extrusion, kneading and/or rolling of the components, in particular a melt of the polymers A1 and optionally A2 and/or A3, component C and optionally component D, mixed together. Subsequently, the matrix composition M thus obtained was formed in the form of a thermoplastic film. The thermoplastic film preferably has a thickness of 25 μm to 500 μm, preferably 50 to 400 μm. The thermoplastic film thus comprises components A, C, and optionally D.

The combination of the at least one thermoplastic molding composition A, the at least one inorganic filler C, and optionally the at least one further additive D with the at least one continuous reinforcing fiber B, according to process step (iii) preferably takes place at elevated temperature. The components A, B, C and optionally D are particularly preferably heated to a temperature of more than 130°C, in particular of at least 160°C.

Process step (iii) is preferably carried out in such a way that at least one layer structure L is obtained from at least two layers, the layer structure L being at least one layer made of reinforcing fibers B, in particular one layer of a fabric G made of reinforcing fibers B, and at least one layer which is at least the matrix composition M comprises.

In a preferred embodiment of the invention, a layer structure L is provided from at least one layer of reinforcement fibers B, in particular one layer of a fabric G from reinforcement fibers B, and at least two layers, which comprise at least the matrix composition M, wherein the at least two layers, which at least the matrix composition M, arranged on the respective first and second surface of the at least one layer of reinforcing fibers B, in particular a layer of a fabric G of reinforcing fibers B are, so that the at least one layer of reinforcing fibers B, in particular a layer of a fabric G made of reinforcing fibers B, is arranged between at least two layers, which comprise at least the matrix composition M.

In a further embodiment of the invention, a layer structure L is provided from a large number (i.e. at least 4) layers, the layer structure L having at least n layers of reinforcing fibers B, in particular one layer of a fabric G made of reinforcing fibers B, and at least m layers, which at least Matrix composition M comprises, where n>1, in particular>2 and m>1, preferably>2. Adjacent layers can be the same as or different from one another. Optionally, the layered structure L can also include further layers, which include the at least one thermoplastic molding compound A, but essentially contain no filler C. In order to achieve the inventive effect of improved surface quality, it is necessary for at least the layers that form the surface of the layered structure L (and thus also of the later composite material V) and a particularly high surface quality to have, at least the thermoplastic molding compound A and the filler C, i.e. the matrix composition M. Such a layer is also referred to herein as a surface layer O.

Layers of reinforcing fibers B are provided in particular in the form of layers of a fabric G made of reinforcing fibers B.

Layers of thermoplastic molding composition A (i.e. without filler C) are provided, in particular in the form of powders, granules, melts or films, which comprise the molding composition A and optional additives D. These are preferably applied directly to at least one surface of an adjacent layer, in particular a layer of reinforcing fibers B, e.g. This can be done by sprinkling (in the case of powders or granules), pouring and/or raking (in the case of melts) or laying on (in the case of films). Layers of thermoplastic molding composition A are preferably applied in the form of powders or films.

Layers of the matrix composition M are provided according to the invention by providing the filler C in the form of powder with the thermoplastic molding composition A and optionally with the optional additives D in the form of a film and is applied to at least part of a surface of a layer of reinforcing fibers B, eg a layer of a fabric G.

In a preferred embodiment of the invention, the layer structure L comprises at least one surface layer O, which is formed from a film which comprises at least one thermoplastic molding compound A and optional additives D.

In a further preferred embodiment of the invention, at least one surface layer O comprises at least the matrix composition M according to the invention. Such a layer structure L is particularly suitable for significantly reducing the occurrence of adhesions of the filler C on the pressing tool during production and also for obtaining composite materials V with surfaces with a particularly high surface quality (low waviness, high gloss).

According to process step iii), the thermoplastic matrix composition M is brought together with the at least one continuous reinforcing fiber B, preferably at least one fabric G. For this purpose, the thermoplastic film made of the thermoplastic matrix composition M is arranged flat on at least part of the first surface of the fabric G made of reinforcing fibers B . Optionally, the thermoplastic film of thermoplastic matrix composition M may be sheeted onto at least a portion of the first and at least a portion of the second surface of the sheet G of reinforcing fibers B . Preferably, the sheet G and the thermoplastic film are each mounted on a dispenser for semi-continuous joining.

In one embodiment of the invention, the sheet-like structure G is placed with the first surface on at least one first thermoplastic film made from the thermoplastic matrix composition M. At least one second thermoplastic film made from the thermoplastic matrix composition is then or simultaneously optionally placed on the second surface of the fabric G. The layer structure L thus obtained is then preferably prefixed in method step (iii) by heating the layer structure L to a temperature of more than 130°C, in particular of at least 160°C. Process step (iii) is preferably carried out at least temporarily at a temperature in a range from 160°C to 350°C, particularly preferably at a temperature in a range from 190°C to 290°C. Suitable methods and devices are known to those skilled in the art. For example, interval hot presses can be used to advantage. In alternative embodiments, a multiplicity of thermoplastic films from the thermoplastic matrix composition and/or fabrics G can be assembled into a layer structure L in order to obtain composite materials V with the desired thickness, the layer structure L having at least one thermoplastic film from the thermoplastic matrix composition M and at least a fabric G made of reinforcing fibers B comprises.

In one embodiment of the invention, in addition to the at least one thermoplastic film made from the thermoplastic matrix composition M, further layers made from thermoplastic molding composition A and optional additives D can be incorporated into the layered structure L to produce the composite material. These are preferably also used in the form of thermoplastic films which comprise the molding composition A and optionally the additives D, but are essentially free from fillers C. This means that the filler-free, thermoplastic films, in contrast to the thermoplastic films from the thermoplastic matrix composition M, comprise less than 5% by weight, based on the total weight of the thermoplastic film, of particulate, inorganic filler e, preferably less than 2% by weight. -%. In a sequence of at least two fabrics G made of reinforcing fibers B, at least one filler-free thermoplastic film is preferably arranged between the fabrics F, while the thermoplastic films containing filler C are preferably used only as surface layers O of a layer structure L. A composite material V with a lower filler content is thus obtained, which nevertheless has a good surface quality.

According to process step (iv), the continuous reinforcing fiber B is impregnated with the matrix composition M. For this purpose, the prefixed layer structure L obtained in process step (iii) is heated to a temperature of at least 180° C., particularly preferably at a temperature in the range from 200 to 290° C., in order to melt the thermoplastic molding composition A and thus enable impregnation . Due to the comparatively low viscosity of the thermoplastic molding composition A, preferably complete impregnation of the continuous reinforcing fibers B with the molding composition A is possible with sufficient speed. As a rule, a time interval of 0.1 to 30 minutes, more preferably 0.2 to 10 minutes, is sufficient to achieve complete impregnation of the continuous reinforcing fibers B with the thermoplastic molding composition A. The thermoplastic molding composition A penetrates into the interstices of individual continuous reinforcing fibers B and also partially into interstices between the individual filaments (ie in the filament bundles) from which the continuous reinforcing fibers B are formed. The optional additives D generally penetrate together with the thermoplastic molding composition A into the interstices mentioned in the filament bundles.

According to the invention, the inorganic fillers C only penetrate to a maximum of 10% into the filament bundles of the continuous reinforcing fibers B, based on surface areas of a cross section of the filament bundles. This increases the local concentration of particulate, inorganic filler C outside the filament bundles. This has a positive effect on the surface quality of the composite materials V, which have particularly low surface waviness. The waviness present due to the continuous reinforcing fibers B is thus compensated for by the particulate, inorganic filler C. This effect can be achieved through the properties of the inorganic filler C, the continuous reinforcing fibers B and the thermoplastic molding composition A described herein, in particular through their relationships with regard to the thermal expansion coefficients and the volume shrinkage.

In step (v), during the consolidation, air inclusions in the composite material V are reduced and a good bond is produced between the thermoplastic molding composition A and the continuous reinforcing fibers B (in particular when the continuous reinforcing fibers B are embedded in layers). After impregnation and consolidation, it is preferable to obtain a (as far as possible) pore-free composite material.

The reinforcing fibers B can be impregnated and consolidated as a sheet-like structure G in a single processing step with the at least one thermoplastic film made from the thermoplastic matrix composition M and the additional, filler-free thermoplastic film(s) that may be used. The composite material V can thus be produced particularly efficiently. Alternatively, the steps mentioned can be carried out in a separate sequence. For example, layers of reinforcing fibers B with differently prepared reinforcing fibers B can first be produced, the reinforcing fibers B being partially impregnated with the matrix composition M of thermoplastic molding composition A and filler e. After that, partially impregnated layers with reinforcement fibers B with different fiber-matrix adhesion can be present, which can be completely impregnated and consolidated as a composite material V in a further work step to form a material composite. Before the layers of reinforcing fibers B are laminated with the thermoplastic matrix composition M, at least some of the reinforcing fibers B can be subjected to a pretreatment, during which the subsequent fiber-matrix adhesion is influenced.

The pre-treatment can include, for example, a coating step, an etching step, a heat treatment step or a mechanical surface treatment step. In particular, an adhesion promoter that has already been applied can be partially removed, for example by heating part of the reinforcing fibers B.

The reinforcement layers can be completely connected to each other during the manufacturing process (lamination). Such composite materials offer optimized strength and rigidity in the fiber direction and can be further processed in a particularly advantageous manner.

The method according to the invention for producing the composite materials V according to the invention preferably comprises at least the following method steps: i) providing at least one sheet G made of reinforcing fibers B; ii) providing at least one thermoplastic matrix composition M, comprising at least one thermoplastic molding composition A, at least one particulate, inorganic filler e, and optionally at least one additive D, wherein the thermoplastic matrix composition M is obtained by mixing components A, C and optionally D, and wherein the thermoplastic matrix composition M is provided in the form of a thermoplastic film; iii) merging at least one thermoplastic film from the thermoplastic matrix composition M with at least one fabric G from reinforcing fibers B, wherein the thermoplastic film from the thermoplastic matrix composition M is laid flat on at least part of a surface of the sheet G of reinforcing fibers B; iv) impregnation of the reinforcing fiber B with the thermoplastic matrix composition M; v) consolidation of the composite V; vi) optional solidification and/or optional further process steps.

In a further preferred embodiment, the method for producing the composite material V according to the invention comprises the steps: i) providing at least one fabric G made of reinforcing fibers B, the surface of the reinforcing fibers B having one or more functional groups selected from hydroxy, ester, amino, and silanol groups; ii-a) providing at least one thermoplastic film from a thermoplastic matrix composition M, comprising at least one thermoplastic molding composition A, at least one particulate, inorganic filler C with a particle size D50 in the range of up to 300 μm, and optionally at least one additive D with a mean film thickness from 25 µm to 500 µm thick; ii-b) optionally providing at least one further thermoplastic film, comprising at least one thermoplastic molding composition A, and optionally at least one additive D, wherein the thermoplastic film essentially contains no particulate, inorganic filler e; iii-a) combining at least the filler-containing thermoplastic film obtained in process step ii-a) with the fabric G made of reinforcing fibers B at a temperature of 160 to 290 ° C, wherein the at least one filler-containing thermoplastic film and the at least one Flat structures G are arranged flat on top of one another in order to obtain an at least two-layer, prefixed layer structure L; iii-b) optionally combining the layer structure L obtained in process step iii-a) with at least one filler-free thermoplastic film obtained according to process step ii-b) at a temperature of 160° C. to 350° C., preferably in a temperature range of 190° C to 290 ° C, wherein the method step iii- a) and the method step iii-b) can be carried out at the same time or at different times in order to obtain a multi-layer, prefixed layer structure L, which has at least one surface layer O of the layer structure L, which consists of a thermoplastic film formed from the matrix composition M according to process step ii-a); iv) impregnation of the reinforcing fiber B with the matrix composition M at a temperature of at least 180°C, preferably at a temperature ranging from 200 to 290°C and a pressure of 1 to 3 MPa; v) consolidation of the composite material V thus obtained; vi) optional solidification and/or optional further process steps.

The process according to the invention for producing the composite material V can be carried out continuously, semi-continuously or discontinuously.

According to a preferred embodiment, the process is carried out as a continuous process, in particular as a continuous process, e.g. for the production of smooth or three-dimensionally embossed composite materials V.

Alternatively, the method according to the invention for producing the composite material V can be carried out semi-continuously or discontinuously.

The process for producing the composite material V according to the invention can preferably be carried out using an interval hot press.

In step (v), during the consolidation, air inclusions in the composite material V are reduced and a good bond is produced between the thermoplastic molding composition A and the reinforcing fibers B (in particular when the reinforcing fibers B are embedded in layers). After impregnation and consolidation, it is preferable to obtain a (as far as possible) pore-free composite material.

According to a preferred embodiment, the method comprises a three-dimensional shaping to form a molded part T as a further step (vi).

This can be done in any way, such as mechanical shaping by a shaping body, which can also be a roller with embossing. The still formable composite material V, in which the thermoplastic molding composition A is still (partially) molten, is preferably formed. Alternatively or additionally, a hardened composite material V can also be cold-formed. A (largely) solid molded part or composite material V is preferably obtained at the end of the process. The method therefore preferably comprises curing the molded part or the product obtained from step (v) as a further step (vi). This step is often referred to as solidification. The solidification, which usually takes place with the withdrawal of heat, usually leads to a ready-to-use molded part. Optionally, the molded part or the composite material V can also be post-processed, for example by the steps of milling, cutting, burring, polishing and/or coloring.

In a preferred embodiment, the method comprises a ribbing step. The improvement in component rigidity through ribbing (creation of a ribbed structure) is based on the increase in area moment of inertia. In general, the optimal dimensioning of the ribs includes aspects of production technology, aesthetics and design. The method steps for ribbing are known to those skilled in the art.

A further aspect of the invention relates to the use of the composite material V according to the invention for the production of molded parts T, for example by conventional deformation processes such as compression molding, rolling, hot pressing, stamping.

A further aspect of the invention relates to the thermoplastic matrix composition M according to the invention described herein, containing the thermoplastic molding composition A, the at least one inorganic particulate, inorganic filler C and optionally one or more further additives D. The thermoplastic matrix composition M according to the invention can preferably be in the form of a film together are provided with the at least one continuous reinforcing fiber B, preferably in the form of a fabric G, preferably selected from woven fabrics, mats, nonwoven fabrics, scrims and knitted fabrics, and are processed into bandage materials with a high surface quality.

The preferred embodiments with regard to the composition of the composite material V to be produced and the components A, B, C and D to be used are described below.

Composite V The inventive method is used to produce a fiber-reinforced, thermoplastic composite V, comprising (or consisting of): a)> 5 to <20 wt .-%, preferably> 7 to <18 wt .-%, a thermoplastic molding composition A, wherein the thermoplastic molding composition A comprises at least one thermoplastic polymer A1, preferably at least one polyolefin, and optionally at least one polar functionalized polymer A2, comprising repeating units of at least one functional monomer A2-I; b) >20 to <80% by weight, preferably >50 to <80% by weight, of at least one continuous reinforcing fiber B in the form of filament bundles, comprising a large number of filaments, preferably selected from inorganic or organic reinforcing fibers, particularly preferably selected made of glass fibers and/or carbon fibers, particularly preferably made of glass fibers; c) > 1 to <60% by weight, preferably > 3 to <45% by weight, of at least one particulate, inorganic filler C, preferably selected from glass fillers, mineral fillers, ceramic fillers and mixtures thereof, and d) > 0 to <10% by weight, preferably >0.01 to <10% by weight, more preferably >0.1 to <5% by weight, of at least one further additive D, preferably selected from processing aids, stabilizers, lubricants and mold release agents, flame retardants, dyes, pigments and plasticizers; wherein the at least one particulate, inorganic filler C has a linear thermal expansion coefficient Oc (CLTE, Coefficient of Linear Thermal Expansion, measured according to ISO 11359-1 and ISO 11359-2) which is lower than the linear, thermal expansion coefficient OA of the thermoplastic molding composition A (also measured according to ISO 11359-1 and ISO 11359-2), ie the relationship (I) applies:

Oc < OA (I); wherein the at least one particulate, inorganic filler C has a volume shrinkage that is 0.1 to 2 times the volume shrinkage of the continuous reinforcing fiber B, the volume shrinkage resulting from the coefficient of thermal volume expansion ay in 1/K der respective component multiplied by the proportion by weight of the respective component in the composite material V in % by weight/100 and with the reciprocal density of the respective component in g/cm ³ , where the following relationship (II) applies: a _v rX component Cx density B in q/ml. , . > ,,,.

- — — = 0.1 to 2 (II) a _{v B} x proportion B x density C in g/ml with av,c = coefficient of thermal volume expansion of component C in 1/K,

Proportion C = proportion by weight of component C in the entire composite material V in % by weight Z100,

OV,B = coefficient of thermal volume expansion of component B in 1/K,

Proportion B=proportion by weight of component B in the entire composite material V in % by weight/100; and where the following relationships hold: av,c = 3 * 0c; and civ.B = 3 * OB with

□A = average linear thermal expansion coefficient of component A;

OB = average linear thermal expansion coefficient of component B; and

Oc = average linear thermal expansion coefficient of component C; and where the percentages by weight are in each case based on the entire fiber-reinforced, thermoplastic composite material V and the sum of components A, B, C and D is 100% by weight.

For the purposes of the present invention, the linear thermal expansion coefficient a (CLTE, Coefficient of Linear Thermal Expansion) is determined according to ISO 11359-2 (in particular ISO 11359-2:1999), with ISO 11359-1 (in particular ISO 11359-2: 2015) describes the general principles of thermomechanical test methods. Typically, the linear thermal expansion coefficient a (in particular the average linear thermal expansion coefficient a) in 1/K results from the following relationship (III): With

AL = change in length of the test sample between two temperatures Ti and T2;

AT = temperature change (= T2-T1);

Lo = reference length of the sample at room temperature in the direction of measurement.

The size and location of the temperature range AT is typically selected in accordance with the ISO 11359-1, 2 standards. Typically, the coefficient of thermal expansion is determined in a temperature range ΔT in the range from -30 to 200°C, in particular 40 to 150°C, in particular 70 to 120°C.

Typically, the coefficient of thermal volumetric expansion Ov is obtained by replacing the terms “length” with “volume” in equation (III). As an approximation, it can be assumed that the coefficient of thermal volume expansion Ov corresponds to three times the linear thermal expansion coefficient a (av= 3 * a). A value averaged over two or three of the dimensions of the test sample is often used as the coefficient of linear thermal expansion, a.

For the purposes of the present invention, the volume shrinkage of the at least one filler C is as follows:

AVc = Ov,c * weight fraction of component C in the total composite

V in % by weight / 100 / density of component C in g/cm ³ ; where approximately Ov,c = 3 * Oc

According to the present invention, the volume shrinkage of the at least one continuous reinforcing fiber B is as follows:

AVB = OV,B * weight fraction of component B in the total composite

V in % by weight / 100 / density of component B in g/cm ³ ; where approximately OV,B = 3 * OB.

In embodiments in which the optional component D is present, in particular the proportion of the thermoplastic molding composition A can be adjusted accordingly, so that the sum of components A, B, C and D is 100% by weight and is not exceeded. In a preferred embodiment, the proportions of components A, B, C and optionally D add up to 100% by weight.

A preferred embodiment of the invention relates to a fiber-reinforced, thermoplastic composite material V, comprising (preferably consisting of): a)> 5 to <20 wt .-%, preferably> 7 to <18 wt .-%, a thermoplastic molding composition A, wherein the thermoplastic molding composition A contains at least one thermoplastic polymer A1, preferably at least one polyolefin, and optionally at least one polar functionalized polymer A2, comprising repeating units of at least one functional monomer A2-I; and wherein the at least one polyolefin is selected from homo- or copolymers of ethene, propene, butene and/or isobutene, and wherein the polar functionalized polymer A2 is a copolymer of at least one repeating unit A2-I and at least one repeating unit A2-II is, wherein the at least one repeating unit A2-I is selected from maleic anhydride, N-phenylmaleimide, tert-butyl (meth)acrylate, glycidyl (meth)acrylate and mixtures thereof, and the at least one repeating unit A2-II is selected from ethene, propene, butene, isobutene and mixtures thereof; b) >20 to <80% by weight, preferably >50 to <80% by weight, of at least one continuous reinforcing fiber B in the form of filament bundles, comprising a large number of filaments, preferably selected from inorganic or organic reinforcing fibers, in particular selected from Glass fibers and/or carbon fibers, particularly preferably glass fibers; c) > 1 to <60% by weight, preferably > 3 to <45% by weight, of at least one particulate, inorganic filler C, preferably selected from glass fillers, mineral fillers, ceramic fillers and mixtures thereof, and d) > 0 to <10% by weight, preferably >0.1 to <5% by weight, of at least one further additive D, where the following relationships (I) and (II) apply: □c < C(A (I) and a _v rX proportion Cx density B in q/ml " . . . > - — — = 0.1 to 2 (II) a _{v B} x proportion Bx density C in g/ml with: av, c = coefficient of thermal volume expansion of component C in 1/K,

OV,B = coefficient of thermal volume expansion of component B in 1/K,

Proportion B=proportion by weight of component B in the entire composite material V in % by weight/100; and where the following relationships hold: av,c = 3 * 0c; and civ.B = 3 * OB with:

□A = average linear thermal expansion coefficient of component A; OB = average linear thermal expansion coefficient of component B; and

An alternative preferred embodiment of the invention relates to a fiber-reinforced, thermoplastic composite material V comprising (preferably consisting of): a)> 5 to <20 wt .-%, preferably> 10 to <18 wt .-%, a thermoplastic molding composition A, wherein the thermoplastic molding composition A contains at least one thermoplastic polymer A1, preferably at least one polyolefin, and optionally at least one polar functionalized polymer A2, comprising at least one functional monomer A2-I; b) >50 to <80% by weight, preferably >50 to <60% by weight, of at least one continuous reinforcing fiber B in the form of filament bundles, comprising a multiplicity of filaments; c) > 20 to < 45% by weight, preferably > 30 to < 40% by weight, of at least one inorganic, mineral filler C, preferably selected from inorganic carbonates, particularly preferably calcium carbonate, and d) > 0 to < 10% by weight %, preferably >0.1 to <5% by weight, of at least one further additive D where the following applies: a _c <a _A and a _vc x proportion C x density B in q/ml

— - — — = 0.1 to 2 a _VB x proportion B x density C in g/ml with av,c = coefficient of thermal volume expansion of component C in 1/K,

OV,B = coefficient of thermal volume expansion of component B in 1/K,

Proportion B=proportion by weight of component B in the entire composite material V in % by weight/100; and where the following relationships hold: av,c and civ.B With

□A = average linear thermal expansion coefficient of component A;

OB = average linear thermal expansion coefficient of component B; and ac = average linear thermal expansion coefficient of component C; and where the percentages by weight are in each case based on the entire fiber-reinforced, thermoplastic composite material V and the sum of components A, B, C and D is 100% by weight.

Another alternative preferred embodiment of the invention relates to a fiber-reinforced, thermoplastic composite material V comprising (preferably consisting of): a)> 5 to <20 wt .-%, preferably> 10 to <20 wt .-%, a thermoplastic molding composition A, wherein the thermoplastic molding composition A contains at least one thermoplastic polymer A1, preferably at least one polyolefin, and optionally at least one polar functionalized polymer A2, comprising at least one functional monomer A2-I; b) >50 to <80% by weight, preferably >70 to <80% by weight, of at least one continuous reinforcing fiber B in the form of filament bundles, comprising a multiplicity of filaments; c) >1 to <20% by weight, preferably >3 to <10% by weight, of at least one inorganic glass filler C, in particular hollow glass bodies, and d) >0 to <10% by weight, preferably >0.1 to <5% by weight of at least one further additive D, where the following relationships (I) and (II) apply:

Oc < a _A (I) and With:

Ov,c = coefficient of thermal volume expansion of component C in 1/K,

Proportion C = proportion by weight of component C in the entire composite material V in % by weight /100, QV,B = coefficient of thermal volume expansion of component B in 1/K,

The composite material V is preferably characterized in that the thermoplastic molding compound A penetrates into the filament bundles of the continuous reinforcing fibers B, but the fillers C only penetrate up to a maximum of 10% into the filament bundles of the continuous reinforcing fibers B, based on surface areas of a cross section of the filament bundles. This is ensured by a suitable selection of the fillers and leads to an accumulation of the fillers C in the areas of the molding compound A that lie between the continuous reinforcing fibers B. On the other hand, only smaller amounts of filler C are found within the continuous reinforcing fibers B, i.e. between the individual filaments of a filament bundle. The filler e is also found almost exclusively in the outer area of the filament bundles, i.e. in an area up to 10% of the diameter of a single filament bundle. Suitable analysis methods for this are, in particular, electron microscopy or reflected light microscopy of the cross-sectional areas of the continuous reinforcing fibers B in the composite material V.

Thermoplastic matrix composition M To produce the fiber-reinforced composite material V according to the invention, a thermoplastic matrix composition M is first provided according to the invention.

According to the invention, the thermoplastic matrix composition M contains at least the thermoplastic molding composition A described herein, which contains at least one thermoplastic polymer A1 and optionally at least one polar functionalized polymer A2, comprising at least one repeating unit of a functional monomer A2-I, and optionally further polymers A3. The thermoplastic matrix composition M also comprises the at least one particulate inorganic filler C described herein, in particular hollow glass bodies and/or carbonates, and optionally the at least one additive D.

In a preferred embodiment, the thermoplastic matrix composition M comprises the at least one thermoplastic molding compound A and the particulate, inorganic filler C and optionally the additives D or consists of these components A, C and D. In one embodiment, the thermoplastic matrix composition M is formed by mixing the molding compound A provided with the particulate, inorganic filler e and optionally the additives D.

The thermoplastic matrix composition M can be provided by known methods, in particular by co-extruding, kneading and / or rolling the polymers A1 and optionally A2 and / or A3 with the filler C and the optional additives D. The thermoplastic matrix composition M can thus the invention Components A1 and C, components A1, A2 and C, components A1, A2, A3 and C, components A1, A3 and C, and components A1, C and D, components A1, A2, C and D the components A1, A2, A3, C and D, or the components A1, A3, C and D include.

The thermoplastic matrix composition M is provided according to the invention as a thermoplastic film. Preferably, the thermoplastic matrix composition M is provided as a thermoplastic film having a thickness of 25 μm to 500 μm, preferably 50 to 400 μm, more preferably 65 to 200 μm. The thermoplastic matrix composition M comprises 20 to 80% by volume, preferably 20 to 70% by volume, in particular 30 to 60% by volume, based on the total volume of the matrix composition M, of the at least one particulate inorganic filler C, preferably selected from particulate mineral or amorphous (glass-like) spherical fillers, preferably selected from hollow glass spheres or carbonates. The rest of the thermoplastic matrix composition M consists of the thermoplastic molding composition A described herein, which preferably consists of the polymers A1 and A2, and optionally the additives D.

In one embodiment of the invention, in addition to the films from the matrix composition, thermoplastic films which essentially do not comprise fillers C are also provided. For this purpose, the components A and optionally D are brought together in process step (ii) as a powder, as a granulate, as a melt or as a thermoplastic film with the fabric G made of continuous reinforcing fibers B. In one embodiment of the invention, components A and optionally D are combined with continuous reinforcing fiber B, preferably as a thermoplastic film.

Thermoplastic molding compound A

The composite material V produced according to the invention contains at least 5% by weight, generally at least 7% by weight, based on the total weight of the composite material V, of the thermoplastic molding composition A. The composite material V generally contains <20% by weight at most 18% by weight, based on the total weight of the composite material V, of the thermoplastic molding composition A.

The thermoplastic molding composition A is contained in the composite material V from 5 to <20% by weight, preferably from 7 to 18% by weight, in particular 10 to 18% by weight, based on the composite material V.

The thermoplastic molding composition A is preferably contained in the composite material V from 5 to 50% by volume, preferably from 10 to 40% by volume and particularly preferably from 15 to 35% by volume, based on the composite material V. The thermoplastic molding composition A contains at least one thermoplastic polymer A1. The thermoplastic polymer A1 is preferably an amorphous or partially crystalline polymer. The thermoplastic polymer A1 is preferably an amorphous or partially crystalline polymer selected from polystyrenes (PS), styrene/acrylonitrile copolymers (PSAN), acrylonitrile/butadiene/styrene copolymers (ABS), acrylate/styrene/acrylonitrile copolymers (ASA), polycarbonates, such as polycarbonates based on bisphenol A, polyesters, polyamides, such as polyamide 6 and polyamide 6,6, polyolefins, and mixtures of the aforementioned polymers. In a particularly preferred embodiment of the invention, the thermoplastic polymer A1 comprises at least one polyolefin or consists of at least one polyolefin, it being possible for the polyolefin to be a polyolefin homopolymer and/or a polyolefin copolymer.

In addition to the thermoplastic polymer A1, the thermoplastic molding composition A can optionally comprise at least one polar functionalized polymer A2, which comprises repeating units of at least one functional monomer A2-I. In addition, the thermoplastic molding composition A can comprise further polymers A3 which are different from the polymers A1 and A2.

In one embodiment, the thermoplastic molding composition A1 contains up to 100% by weight of the at least one thermoplastic polymer A1 selected from homo- or copolymers of polyamide, polypropylene and polyethene.

The thermoplastic molding composition A can also contain from 0 to 99% by weight of the at least one polymer A2 and/or the polymers A3, based in each case on the total weight of the thermoplastic molding composition A.

In a preferred embodiment, the thermoplastic molding composition A contains 60 to 99.9% by weight, more preferably 70 to 99.9% by weight, particularly preferably 75 to 99.9% by weight, particularly preferably 90 to 99% by weight. -%, more preferably 94 to 97% by weight, of the at least one thermoplastic polymer A1, in particular a thermoplastic polyolefin homopolymer or polyolefin copolymer A1, and

0.1 to 40% by weight, preferably 0.1 to 30% by weight, particularly preferably 0.1 to 20% by weight, particularly preferably 1 to 10% by weight, more preferably 3 to 6% by weight. % of the at least one polar functionalized polymer A2, the percentages by weight in each case being based on the total weight of the thermoplastic molding composition A. In a preferred embodiment of the invention, the thermoplastic molding composition A comprises the polymers A1 and A2 and comprises no further polymers A3.

In an alternative embodiment, the thermoplastic molding composition A contains the polymers A1 and A2 and optionally at least one further polymer A3. Typically, the at least one optional polymer A3 can be selected from any thermoplastic polymer other than A1 and A2. For example, the at least one optional polymer A3 can be selected from polystyrenes (PS), styrene/acrylonitrile copolymers (PSAN), acrylonitrile/butadiene/styrene copolymers (ABS), acrylate/styrene/acrylonitrile copolymers (ASA), polycarbonates, polyesters , polyamides, polyolefins and mixtures thereof. The at least one optional polymer A3 is particularly preferably selected from polyethene, ethene/propene copolymers, styrene polymers and styrene/acrylonitrile copolymers, with the proviso that the at least one polymer A3 is different from the polymers A1 and A2. The polymer A3 can preferably be at least one amorphous polymer. In particular, the thermoplastic molding composition A has a proportion by weight of less than 50% by weight of polymers A3, more preferably less than 30% by weight.

The thermoplastic molding composition A preferably contains (or consists of): a-1) 50 to 99.9% by weight, preferably 70 to 99.9% by weight, particularly preferably 79 to 98% by weight, particularly preferably 90 up to 97% by weight of a thermoplastic polymer A1; a-2) 0.1 to 20% by weight, preferably 0.1 to 10% by weight, particularly preferably 1 to 8% by weight, particularly preferably 3 to 7% by weight, of the at least one polar functionalized polymer A2; a-3) 0 to 49.9% by weight, preferably 0 to 29.9% by weight, more preferably 1 to 20% by weight, of at least one further polymer A3; where the polymers A1, A2 and A3 are different from one another, and where the percentages by weight are in each case based on the total weight of the thermoplastic molding composition A and the sum of the components A1, A2 and A3 is 100% by weight. The thermoplastic molding composition A preferably comprises the components A1, A2 and A3 or consists of these.

More preferably, the thermoplastic molding composition A contains (or consists of): a-1) 60 to 99% by weight of at least one polymer A1 selected from the group consisting of propene homopolymers, propene copolymers, styrene copolymers, polyamides and polycarbonates; a-2) 1 to 40% by weight of a polar functionalized polymer A2; and a-3) 0 to 10% by weight of at least one further polymer A3, the polymer A3 being different from the polymers A1 and A2. where the polymers A1, A2 and A3 are different from one another, and where the percentages by weight are in each case based on the total weight of the thermoplastic molding composition A and the sum of the components A1, A2 and A3 is 100% by weight. The thermoplastic molding composition preferably consists of components A1, A2 and A3.

Thermoplastic Polymer A1

The thermoplastic molding composition A preferably contains at least 50% by weight, preferably at least 60% by weight, in particular at least 80% by weight, of at least one thermoplastic polymer A1, preferably at least one polyolefin, based on the total weight of the thermoplastic molding composition A. Preferably contains the thermoplastic molding composition A contains the at least one polymer A1 in a range from 70 to 99.9% by weight, more preferably 90 to 99% by weight, particularly preferably 92 to 97% by weight, based on the total weight of the thermoplastic molding composition A

The thermoplastic polymer A1 is preferably an amorphous or partially crystalline homopolymer or copolymer of ethene, propene, butene and/or isobutene. The polymer A1 particularly preferably comprises at least one propene homopolymer and/or propene-ethene copolymer (also referred to as polypropene impact copolymer). The polymer A1 particularly preferably comprises (or is) a propene-ethene copolymer.

The polymer A1 is preferably at least one propene-ethene copolymer, the propene-ethene copolymer preferably having a melt mass flow rate MFR (determined according to DIN EN ISO 1133 at 230° C./2.16 kg ) in the range 40g/10min to 120g/10min, preferably 80g/10min to 120g/10min, more preferably 90g/10min to 110g/10min, and often about 100g/10min , having. The polymer A1 n is preferably at least one propene-ethene copolymer with a Density (according to DIN EN ISO 1183-1:2019-09) <0.95 g/cm ³ , in particular in the range from 0.89 g/cm ³ to 0.93 g/cm ³ , preferably from 0.895 g/cm ³ to 0.915 g/ ^cm3 .

The thermoplastic polymer A1 is preferably at least one propene-ethene copolymer with a modulus of elasticity (measured according to DIN EN ISO 178) in the range from 1400 MPa to 2100 MPa, often around 1550 MPa.

The thermoplastic polymer A1 preferably has a thermal expansion coefficient OAI according to ISO 11359-1 and ISO 11359-2 in a range from 50* ^10'6 K'1 to 100* ¹⁰ ^-6 ^K'1 , in particular in a range of 60* 1 O' ⁶ K' ¹ to 90*1 O' ⁶ K' ¹ .

The thermoplastic polymer A1 preferably has a coefficient of thermal volume expansion OV,AI, determined according to the formula described above, in a range from 150*10 ^-6 K' ¹ to 300*10' ⁶ K ^-1 , in particular in a range of 180*10 ^-6 K' ¹ to 270*1 O' ⁶ K' ¹ .

The thermoplastic A1 preferably has a melting point (DSC, measured according to DIN EN ISO 11357-3) in a range from 100 to 200.degree. C., in particular in a range from 135 to 160.degree.

Suitable polyolefins are available, for example, under the trade name Rigidex 380-H100 from INEOS Olefins & Polymers Europe.

Polar Functionalized Polymer A2

The optional polar functionalized polymer A2 is different from polymer A1 and comprises repeating units of at least one functional monomer A2-I.

The thermoplastic molding composition A preferably contains at least 0.1% by weight, more preferably at least 1% by weight, particularly preferably at least 3% by weight, and in particular at least 3% by weight, of the at least one polar functionalized polymer A2, based on the total weight of the thermoplastic molding composition A. The thermoplastic molding composition A preferably contains at most 30% by weight, more preferably at most 20% by weight, particularly preferably at most 15% by weight, and in particular at most 10% by weight, of at least one polar functionalized polymer A2, based on the total weight of the thermoplastic molding composition A. The thermoplastic molding composition A preferably contains the at least one polar functionalized polymer A2 in the range from 0.1 to 30% by weight, preferably 0.1 to 20% by weight, particularly preferably 1 to 15% by weight, particularly preferably 3 to 10% by weight, based on the total weight of the thermoplastic molding composition A.

The polar functionalized polymer A2 serves as a compatibilizer between the thermoplastic molding composition A and the continuous reinforcing fiber B. The polar functionalized polymer A2 has at least one polar, preferably chemically reactive, functionality (typically provided by the repeating units of the at least one functional monomer A2-I), which can react with chemical groups on the surface of the continuous reinforcing fiber B during the manufacturing process of the composite material V and bonds (covalent bonds, ionic bonds, van der Waals bonds) can form, resulting in a composite material V with good strength, in particular a good fiber-matrix adhesion is obtained. The polar-functionalized polymer A2 often increases the polarity of the thermoplastic molding composition A, which increases the compatibility with polar surfaces of the reinforcing fibers, in particular the polar surfaces of glass fibers or surfaces of reinforcing fibers that are polar-functionalized by sizing agents.

In a preferred embodiment, the polar functionalized polymer A2 comprises at least 0.1% by weight, preferably 0.1 to 5% by weight, particularly preferably 0.1 to 3% by weight, particularly preferably 0.1 to 1 5% by weight, more preferably 0.1 to 0.5% by weight, based on the total weight of the polymer A2, of repeating units of the at least one functional monomer A2-I.

According to a preferred embodiment, the at least one functional monomer A2-I is selected from the group consisting of maleic anhydride (MA), N-phenylmaleimide (PM), tert-butyl (meth)acrylate and glycidyl (meth)acrylate (GM), in particular selected from the group consisting of maleic anhydride (MA), N-phenylmaleimide (PM) and glycidyl (meth)acrylate (GM).

In addition to the repeating units A2-I, the polar-functionalized polymer A2 preferably comprises at least repeating units of a further monomer A2-II, which is different from the monomer A2-I. The proportion of repeating units of the monomer A2-II is up to 99.9% by weight, preferably in a range from 95 to 99.9% by weight, particularly preferably 97 to 99.9% by weight, particularly preferably 98.5 to 99.9% by weight, more preferably 99.5 to 99.9% by weight, based on the total weight of the polymer A2, of repeating units of the at least one monomer A2-II.

The monomer A2-II is preferably selected from ethene, propene, butene and/or isobutene.

The polar functionalized polymer A2 is preferably a copolymer of repeating units of at least one monomer A2-II selected from ethene, propene, butene and/or isobutene, and repeating units of at least one functional monomer A2-I selected from maleic anhydride, N-phenylmaleimide , tert-butyl (meth)acrylate and glycidyl (meth)acrylate. More preferably, the polar functionalized polymer A2 is a copolymer of propene repeating units and repeating units of at least one functional monomer A2-I selected from maleic anhydride, N-phenylmaleimide, tert-butyl (meth)acrylate and glycidyl (meth) acrylate. The polar functionalized polymer A2 is particularly preferably a propene graft copolymer, repeating units of the abovementioned functional monomers A2-I being grafted onto a polypropene. The polar functionalized polymer A2 is preferably a propene-maleic anhydride graft copolymer, the graft core consisting predominantly of propene repeating units and the graft shell consisting predominantly of maleic anhydride repeating units. Such polar functionalized polymers A2 and their preparation are described, for example, in US Pat. No. 10/189933 B2. They are known, for example, under the product names PRIEX® 20093 (BYK), Orevac® CA100 (Arkema) and Scona® TPPP 9021 (BYK) and are commercially available.

The polar functionalized polymer A2 is particularly preferably one or more propene-maleic anhydride graft copolymers which have a proportion of maleic anhydride as monomer A2-I in the range from 0.01 to 5% by weight, preferably 0.1 to 0 4% by weight, particularly preferably from 0.15 to 0.25% by weight, based on the total weight of the polar functionalized polymer A2. In particular, the polar functionalized polymer A2 is a polymer which has a density (according to DIN EN ISO 1183-1:2019-09) in a range from 0.8 to 1.0 g/cm ³ , preferably in a range from 0.85 g/cm ³ to 0.95 g/cm ³ , in particular from 0.895 g/cm ³ to 0.915 g/cm ³ , often from about 0.9 g/cm ³ .

The polar functionalized polymer A2 preferably has a melt mass flow rate (MFR) (determined according to DIN EN ISO 1133, at 190° C./0.325 kg) in the range from 8 g/10 min to 15 g/10 min, in particular 9 g /10 min to 13 g/10 min.

The polar functionalized polymer A2 is preferably a polymer which has a melting point (measured according to DIN EN ISO 11357-3) in the range from 160 to 165° C. and/or a viscosity (measured according to DIN EN ISO 1628-1) in the range of 0.07 to 0.08 l/g.

In a preferred embodiment of the invention, polymer A1 is a propene-ethene copolymer, preferably with a density of 0.898 g/cm ³ to 0.900 g/cm ³ ; and the functionalized polymer A2 is a propene graft copolymer (such as PRI EX® 20093 from BYK-Chemie).

Continuous reinforcement fiber B

The composite material V produced according to the invention contains at least 20% by weight, preferably at least 40% by weight, particularly preferably at least 45% by weight, particularly preferably at least 50% by weight, based on the total weight of the composite material V, of the continuous reinforcing fibers B. In a preferred embodiment, the composite material V contains >50% by weight, based on the total weight of the composite material V, of the continuous reinforcing fiber B.

The composite material V generally contains at most 80% by weight, based on the total weight of the composite material V, of the continuous reinforcing fibers B.

The at least one continuous reinforcing fiber B is contained in the composite material V from 20 to 80% by weight, preferably from 40 to 80% by weight, particularly preferably from 50 to 80% by weight, based on the composite material V. In a preferred embodiment, the at least one continuous reinforcing fiber B is contained in the composite material V in an amount of 51 to 80% by weight, based on the composite material V. The continuous reinforcing fiber B is preferably contained in the composite material V from 20 to 80% by volume, preferably from 30 to 70% by volume and particularly preferably from 40 to 55% by volume, based on the composite material V.

The continuous reinforcement fibers B are preferably selected from glass fibers, carbon fibers, aramid fibers and natural fibers and/or mixed forms of the continuous reinforcement fibers B mentioned. The continuous reinforcement fibers B are more preferably selected from glass fibers and/or carbon fibers, in particular glass fibers.

Typically, the density of the continuous reinforcing fiber B ranges from 1.4 g/cm ³ to 2.8 g/cm ³ . Preferably, the density of the continuous reinforcing fiber B selected from glass fibers is in the range from 1.8 g/cm ³ to 2.8 g/cm ³ . Preferably, the density of the continuous reinforcing fiber B selected from carbon fibers is in the range of 1.4 g/cm ³ to 1.9 g/cm ³ . Suitable methods for density determination are known to those skilled in the art. The density of the continuous reinforcing fiber B is typically determined according to test standard ASTM C693.

The continuous reinforcement fiber B is typically a bundle of a multiplicity of filaments. Such bundles of filaments (also referred to as multifilaments) are formed during the manufacture of fibers. The continuous reinforcing fiber B according to the invention therefore corresponds to a filament bundle made up of a large number of individual filaments.

Typically, the continuous reinforcing fiber B comprises a large number of individual filaments, the mean filament diameter being in a range from 2 to 35 μm, preferably from 5 to 25 μm. The filaments of the continuous reinforcing fiber B are often bundled into rovings, fabrics and/or yarns.

In a further preferred embodiment, the continuous reinforcing fibers B have one or more functional groups, preferably polar functional groups, particularly preferably functional groups selected from hydroxyl, ester, amino and silanol groups, on at least part of their surface. The polar functional fibers arranged on the surface of the continuous reinforcing fibers B Len groups can be formed directly by the fiber material itself (especially in the case of glass fibers) or by applying at least one sizing agent to the surface of the continuous reinforcing fibers B.

Thus, in one embodiment of the invention, the continuous reinforcing fiber B may comprise a sizing agent applied to at least a portion of the surface of the continuous reinforcing fiber B . Fibers for fibrous reinforcing materials are often treated with a sizing agent, particularly to protect the reinforcing fibers. Mutual damage caused by abrasion can thus be prevented. If a mechanical impact occurs, there must be no cross-fragmentation (breakage) of the reinforcing fibers. In addition, the sizing agent can prevent agglomeration of the reinforcing fibers. A sizing agent can also contribute to improved cohesion between the reinforcing fibers and the polymer matrix in the composite material V.

Suitable sizing agents generally include a large number of different ingredients such as film formers, lubricants, wetting agents and adhesives.

Film formers protect the fibers from rubbing against each other and can also increase affinity for polymers, thereby promoting composite strength and adhesion. Mention may be made of starch derivatives, polymers and copolymers of vinyl acetate and acrylic esters, epoxy resin emulsions, polyurethane resins and polyamides in a proportion of 0.5 to 12% by weight, based on the total weight of the sizing agent.

Lubricants give the fibers and their products flexibility and reduce the friction between the reinforcing fibers. However, the adhesion between the reinforcing fiber and the polymer is often impaired by the use of lubricants. Mention should be made of fats, oils and polyalkyleneamines in an amount of 0.01 to 1% by weight, based on the total weight of the sizing agent.

Wetting agents cause a reduction in surface tension and improved wetting of the filaments with the sizing agent. For example, polyfatty acid amides in an amount of 0.1 to 5% by weight, based on the total weight of the sizing agent, should be mentioned for aqueous finishing. Often there is no suitable affinity between the polymer matrix and the reinforcing fibers. This can be overcome by using adhesives that increase the adhesion of polymers to the fiber surface. Typically, organofunctionalized silanes such as aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, glycidyloxypropyltrimethoxysilane, and the like are used.

In an alternative, preferred embodiment of the invention, the continuous reinforcing fibers B of the present invention are (essentially) free of a sizing agent, i.e. they comprise less than 3% by weight, preferably less than 1% by weight, and in particular less than 0 1% by weight of sizing agent, based on the total weight of the continuous reinforcing fibers B. If the continuous reinforcing fibers B (e.g. due to production) comprise a sizing agent which is applied to at least part of the surface of the continuous reinforcing fibers B, the sizing agent can be present of use according to the present invention. This can be achieved, for example, by thermal desizing processes (e.g. incineration of the sizing agent).

In one embodiment, the continuous reinforcing fiber B is one or more glass fibers. The at least one continuous reinforcing fiber B is particularly preferably one or more glass fibers whose surface comprises functional groups selected from hydroxyl, ester, amino and silanol groups, preferably silanol groups.

Typically, the well-known qualities of glass fibers are used, depending on the requirements and area of application, e ; aluminum silicate glass with additions of magnesium oxide), R glass (R=Resistance, aluminum silicate glass with additions of calcium and magnesium oxide), M glass (M=modulus, glass containing berrylium), C glass ( C=Chemical, fiber with increased chemical resistance), ECR glass (E-Glass Corrosion Resistant), D glass (D = Dielectric, fiber with low dielectric loss factor), AR glass (AR=Alkaline Resistant, for use in concrete developed fiber enriched with zirconium (IV) oxide), Q-glass (Q=quartz, fiber made of quartz glass SiÜ2) and hollow glass fibers. E-glass fiber is often used as the standard fiber for general plastic reinforcement and electrical applications. In a preferred embodiment of the invention, glass fibers with a filament diameter of 5 to 25 μm are used, which are usually combined with multifilament yarn (roving). Such a multifilament yarn (roving) preferably has a fineness of 1200 tex. These are preferably used both as warp threads and as weft threads in a fabric G.

In addition, it is also possible to use carbon fibers (also called carbon fibers or carbon fibers) as the continuous reinforcing fiber B. Typically, carbon fibers are industrially manufactured fibers made from carbon-containing starting materials, which are converted into graphite-like carbon by chemical reactions adapted to the raw material. Common isotropic and anisotropic types can be used, with anisotropic fibers typically having high strength and rigidity combined with low elongation at break in the axial direction. Carbon fibers are often used as a stiffening component for lightweight construction. Typically, carbon fibers have a diameter of about 5 to 9 microns, with 1,000 to 24,000 filaments usually being combined to form a multifilament yarn (roving).

The continuous reinforcing fiber B is preferably used as the fabric G. The flat structure G is preferably a scrim, a woven fabric, a mat, a fleece, a knitted fabric, a mesh or a multiaxial scrim, which is formed at least partially from filament bundles of the continuous reinforcing fibers B. The continuous reinforcing fiber B is preferably embedded in the composite material V as a flat structure G, preferably selected from woven fabrics, mats, nonwoven fabrics, scrims and knitted fabrics, in particular woven fabrics and scrims.

The further processing of continuous reinforcing fiber B to fabrics G in the form of semi-finished textile products such. g. scrims, woven fabrics, mats, nonwovens, knitted fabrics, braids or multiaxial fabrics, is usually carried out on weaving machines, braiding machines or multiaxial knitting machines or, in the area of the production of fiber-reinforced plastics, directly on prepreg systems, pultrusion systems (pultrusion systems) or winding machines. The continuous reinforcing fibers B can be embedded in the composite material V as a flat structure G in any orientation and arrangement. The continuous reinforcing fibers B are often not statistically evenly distributed in the composite material V, but rather as a flat structure G, ie in levels with a higher and in levels with a lower proportion (therefore as more or less separate layers). A laminate-like or laminar structure of the composite material V is preferably assumed, the composite material V comprising a multiplicity of flat structures G, comprising the continuous reinforcing fibers B.

Flat laminates formed in this way typically contain composites built up in layers from flat reinforcement layers (surface structure G comprising continuous reinforcement fibers B) and layers of a wetting and cohesive matrix composition (also referred to herein as matrix composition M), which comprises at least the thermoplastic molding composition A. According to a preferred embodiment, the continuous reinforcing fibers B are embedded in the composite material V in layers. The continuous reinforcing fibers B are preferably present as a flat structure G.

In a fabric, the fibers are typically ideally parallel and stretched. Endless fibers are mostly used. Fabrics are typically created by weaving endless fibers, such as rovings. The weaving of fibers is inevitably accompanied by a deflection (undulation) of the fibers. In particular, the undulation causes a reduction in the compressive strength parallel to the fibers. Mats usually consist of long fibers that are loosely connected to each other with a binding agent. Due to the use of long fibers, the mechanical properties of components made of mats are inferior to those of fabrics. Nonwovens are typically structures made of fibers of limited length, continuous fibers (filaments) and/or chopped yarns which have been joined together in any known manner to form a nonwoven and usually connected via a binder. Knitted fabrics typically refer to thread systems that are created and connected by stitch formation.

In a further embodiment, the invention relates to a composite material V which has a ribbing or a sandwich structure and is built up in layers. The method steps for ribbing are known to those skilled in the art. In a further embodiment, the invention relates to a composite material V described herein, the composite material V having a layered structure and containing more than two, often more than three, layers. For example, all of the layers can be of the same type or some of the layers can have a different structure. A layer comprises at least one sheet G made of continuous reinforcing fibers B, which is embedded in at least one matrix composition (herein also referred to as matrix composition M), which comprises at least the thermoplastic molding composition A.

Particulate, inorganic filler e

The composite material V produced according to the invention contains at least 1% by weight, preferably at least 3% by weight, particularly preferably at least 4% by weight, based on the total weight of the composite material V, of at least one particulate, inorganic filler C. The composite material V contains at most 60% by weight, preferably at most 45% by weight, particularly preferably at most 40% by weight, based on the total weight of the composite material V, of at least one particulate, inorganic filler e.

The at least one particulate, inorganic filler e is contained in the composite material V from 1 to 60% by weight, preferably 3 to 45% by weight, particularly preferably 5 to 40% by weight, based on the composite material V as a whole.

In a preferred embodiment, the composite material V according to the invention contains at least 5 to 60% by volume, preferably 15 to 50% by volume and particularly preferably 25 to 40% by volume, based on the composite material V, of at least one particulate inorganic filler C .

The particulate, inorganic filler C is preferably selected from glass fillers, mineral fillers, ceramic fillers and mixtures thereof.

Suitable glass fillers include, in particular, glass powder and hollow glass bodies, particularly preferably hollow glass bodies. Glass hollow bodies are characterized by a particularly low density and thus enable the production of fiber-reinforced composites V with a low density. These are advantageous as light but mechanically stable materials.

Suitable mineral fillers include in particular silicates, phosphates, sulfates, carbonates, hydroxides and borates, particularly preferably carbonates. Carbonates, in particular calcium carbonate, are advantageously characterized by worldwide availability at a low price and are also commercially available in many different size distributions.

Suitable ceramic fillers include, in particular, boron nitrite (BN - borazon), aluminum oxide (AI2O3), silicates, silicon dioxide, zirconium(IV) oxide, titanium(IV) oxide, aluminum miniumtitanate, barium titanate and silicon carbide (SiC) and boron carbide (B4C ). Ceramic fillers contribute in particular to improving the hardness and scratch resistance of the composite material V.

The at least one particulate, inorganic filler C is preferably selected from mineral fillers, which can be present both in crystalline form and in amorphous form (in particular as glass fillers). The at least one particulate, inorganic filler e is preferably selected from glass powder, hollow glass bodies, amorphous silica; carbonates (e.g. magnesium carbonate, calcium carbonate (chalk)); powdered quartz; Mica; silicates such as clays, muscovite, biotite, suzoite, tin maletite, talc, chlorite, phlogopite, feldspar; kaolin and calcium silicates (such as wollastonite). Hollow glass bodies and carbonates, in particular calcium carbonate (chalk), are very particularly preferred.

In a preferred embodiment, the composite material V according to the invention contains 3 to 45% by weight of at least one particulate, inorganic filler C in crystalline and/or amorphous form, selected from silicates, phosphates, sulfates, carbonates and borates.

In a further preferred embodiment, the composite material V according to the invention comprises >20 to <45% by weight, more preferably >30 to <40% by weight, of at least one particulate, inorganic filler C selected from inorganic carbonates, preferably calcium carbonate. It was shown that, despite this high amount of filler C, it is possible to provide a composite material V which has good mechanical properties and at the same time surfaces with a particularly low surface waviness, ie having a particularly smooth surface.

In a further alternative preferred embodiment, the composite material V according to the invention comprises >1 to <20% by weight, preferably 3 to <10% by weight, of at least one particulate, inorganic filler C selected from hollow glass bodies. It was possible to show that this quantity of hollow glass bodies is suitable for providing a low-density composite material V which has surfaces with particularly low surface waviness, i.e. with a particularly smooth surface.

In a preferred embodiment, fillers C with an average particle size D50 in the range of up to 300 μm, more preferably of up to 100 μm, particularly preferably of up to 70 μm, in particular in a range of 1 μm to 50 μm, as particulate, inorganic filler C used.

According to the invention, inorganic fillers C are used which have a linear thermal expansion coefficient Oc (ÖLTE, Coefficient of Linear Thermal Expansion, measured according to ISO 11359-1 and ISO 11359-2) which is lower than the linear thermal expansion coefficient OA of the thermoplastic molding composition A, i.e. Oc < QA Preferably the relation Oc < 0.3 OA applies.

The at least one particulate, inorganic filler C also preferably has a coefficient of thermal expansion Oc (ÖLTE, Coefficient of Linear Thermal Expansion, measured according to ISO 11359-1 and ISO 11359-2) which is 0.2 to 5 times greater as the coefficient of thermal expansion OB of the continuous reinforcing fiber B, more preferably 0.3 to 1 times, i.e. 0.2 OBS OC S 5 OB, particularly 0.3 OBS OC S T OB.

The particulate, inorganic filler C preferably has a coefficient of linear thermal expansion Oc (CLTE, Coefficient of Linear Thermal Expansion, measured according to ISO 11359-1 and ISO 11359-2) in the range from 2*10' ⁶ K' ¹ to 20*1 O ' ⁶ K' ¹ , preferably 5*1 O' ⁶ K' ¹ to 15*10 ^-6 K' ¹ , particularly preferably 7*1 O' ⁶ K' ¹ to 12*10 ^-6 K' ¹ . According to the invention, inorganic fillers C are used for which the following relationship (II) applies: 0.1 to 2 (II) With:

Ov,c = coefficient of thermal volume expansion of component C in 1/K,

OV,B = coefficient of thermal volume expansion of component B in 1/K,

Proportion B=proportion by weight of component B in the entire composite material V in % by weight/100; and where: av,c = 3 * 0c; and civ.B = 3 * OB with:

□A = average linear thermal expansion coefficient of component A;

OB = average linear thermal expansion coefficient of component B; and

Oc = mean linear thermal expansion coefficient of component C.

Details for determining the linear thermal expansion coefficient a and the coefficient of thermal volume expansion Ov are described above.

The relationship (IV) preferably applies: a _vr x proportion C x density B in q/ml - - - = 0.44 to 1.5 (IV) a _{v B} x proportion B x density C in g/ml

It was observed that with a value of >0.44 in relation (IV), a 50% reduction in the surface waviness of the composite material V obtained could be achieved.

More preferably, the relationship (V) applies: 0.50 to 1.2

The density of the inorganic fillers C is preferably in a range of 0.1 to 5 g/ml, more preferably in particular 0.2 to 4 g/ml, especially 0.2 to 2.8 g/ml. Suitable methods for determining the density are known to those skilled in the art. The density of inorganic fillers C is typically determined according to the test standard DIN-ISO 787/10. The density of hollow glass spheres, which can preferably be used according to the invention as particulate, inorganic filler e, is preferably in a range from 0.1 to 1.0 g/ml, more preferably in a range from 0.2 to 0.6 g/ml. ml. The density of carbonates, which can preferably be used according to the invention as particulate, inorganic filler C, is preferably in a range from 1.0 to 4.0 g/ml, more preferably in a range from 2.0 to 2.8 g/ml. ml.

In one embodiment of the production of the composite material V according to the invention, the particulate, inorganic filler C is typically added to the thermoplastic molding composition A before the components are contacted with the continuous reinforcing fiber B. In another embodiment, all three components are brought together in one process step. Further details on the production of the composite material V according to the invention can be found in the section on the production process contained herein.

Other additives D

The composite material V produced according to the invention can optionally contain 0 to 10% by weight, preferably 0 to 5% by weight, particularly preferably 0.01 to 10% by weight, particularly preferably 0.1 to 5% by weight, based on the entire composite material V, one or more additives D included. Typically, the optional additive D is customary auxiliaries and additives that are different from components A to C. Typical plastic additives are described, for example, in H. Zweifel et al., Plastics Additives Handbook, Hanser Verlag, 6th edition, 2009.

In the production of the composite material V according to the invention, the additives D are typically added to the thermoplastic molding composition A. For example, the at least one further additive D can be selected from processing aids, stabilizers, lubricants and mold release agents, flame retardants, dyes, pigments and plasticizers. As stabilizers, for example, antioxidants (oxidation retardants) and agents against heat decomposition (heat stabilizers) and decomposition by ultraviolet light (UV stabilizers) are used.

Suitable UV stabilizers include various substituted resorcinols, salicylates, benzotriazoles and benzophenones. UV stabilizers are typically used in amounts of up to 2% by weight, preferably from 0.01 to 2% by weight, based on the composite material V as a whole. Common UV stabilizers are described, for example, in H. Zweifel et al., Plastics Additives Handbook, Hanser Verlag, 6th edition, 2009, pp. 246-329.

Examples of suitable antioxidants and heat stabilizers are sterically hindered phenols, hydroquinones, substituted representatives of this group, secondary aromatic amines, optionally in combination with phosphorus-containing acids or their salts, and mixtures of these compounds. Common antioxidants are described, for example, in H. Zweifel et al., Plastics Additives Handbook, Hanser Verlag, 6th edition, 2009, pages 40 to 64. Antioxidants of the Irganox® (BASF) type are preferably used. Antioxidants and heat stabilizers are typically used in amounts of up to 1% by weight, preferably from 0.01 to 1% by weight, based on the composite material V as a whole.

In a preferred embodiment, the composite material V according to the invention contains one or more lubricants and mold release agents as additives D. Common lubricants and mold release agents are described, for example, in H. Zweifel et al., Plastics Additives Handbook, Hanser Verlag, 6th edition, 2009, p. 563-580. Examples of suitable lubricants and mold release agents are stearic acid, stearyl alcohol, stearic acid esters and amides, and esters of pentaerythritol with long-chain fatty acids. For example, the calcium, zinc or aluminum salts of stearic acid and dialkyl ketones, for example distearyl ketone, can be used.

Furthermore, ethene oxide-propene oxide copolymers can also be used as lubricants and mold release agents. Natural and/or synthetic waxes can also be used. Examples include PP wax, PE wax, PA wax, grafted PO wax, HDPE wax, PTFE wax, EBS wax, montan wax, carnauba and beeswax. Lubricants and mold release agents are typically used in amounts of up to 1% by weight, preferably from 0.01 to 1% by weight, based on the composite material V as a whole.

In a preferred embodiment, the composite material according to the invention contains

V 0.01 to 1 wt. %, preferably 0.1 to 0.9 wt 1-glycerol monostearate.

Suitable flame retardants can be halogen-containing or halogen-free compounds. Suitable halogen compounds are chlorinated and/or brominated compounds, with brominated compounds being preferable to chlorinated ones. Halogen-free compounds such as, for example, phosphorus compounds, in particular phosphine oxides and derivatives of phosphorus acids and salts of acids and acid derivatives of phosphorus, are preferably used. Phosphorus compounds particularly preferably contain ester, alkyl, cycloalkyl and/or aryl groups. Also suitable are oligomeric phosphorus compounds with a molecular weight of less than 2000 g/mol, as described, for example, in EP-A 0 363 608.

Furthermore, pigments and dyes in the composite materials according to the invention

V be included as additives D. These are typically present in amounts of 0 to 10% by weight, preferably 0.1 to 10% by weight and in particular 0.5 to 8% by weight, based on the composite V as a whole. Typical pigments for coloring thermoplastics are well known, see for example H. Zweifel et al., Plastics Additives Handbook, Hanser Verlag, 6th edition, 2009, pp. 855-868 and 883-889 and R. Gachter and H. Müller, Taschenbuch der Kunststoffadditive, Carl Hanser Verlag, 1983, pp. 494 to 510. The first preferred group of pigments are white pigments, such as zinc oxide, zinc sulfide, white lead (2 PbCOs·Pb(OH)2), lithopone, antimony white and titanium dioxide. Of the two most common crystal modifications (rutile and anatase type) of titanium dioxide, the rutile form in particular is used to whiten the molding compositions of the invention. Another preferred group of pigments are black color pigments, such as iron oxide black (FesO 4 , spinel black (Cu(Cr,Fe) 2 O 4 ), manganese black (mixture of manganese dioxide, silicon oxide and iron oxide), cobalt black and antimony black, as well as being particularly preferred Carbon black, which is mostly used in the form of furnace or gas black (see G. Benzing, Pigmente für Anstrichmittel, Expert-Verlag (1988), p. 78ff).

In addition, inorganic colored pigments, such as chrome oxide green, or organic colored pigments, such as azo pigments and phthalocyanines, can be used according to the invention to set specific shades. Such pigments are generally commercially available. Furthermore, it can be advantageous to use the pigments or dyes mentioned in a mixture, for example carbon black with copper phthalocyanines.

In addition to the additives mentioned, which are usually added to the thermoplastic molding composition A, the continuous reinforcing fibers B can also comprise additives, in particular in the form of a surface coating, a so-called size (size). Typically, sizing agents generally contain a large number of different ingredients such as film formers, lubricants, wetting agents and adhesives. These are described in more detail in the description of continuous reinforcing fibers B section herein.

The present invention is further illustrated by the following examples and claims.

examples

Various fiber-reinforced composite materials V were produced from components A1, A2, B, C1 or C2 and D. The components and methods for their characterization are described below.

characterization methods

Unless otherwise stated, the components used were characterized according to the methods described below.

The density of the composite materials V was determined according to DIN EN ISO 1183-1:2019-09 on test specimens using the immersion method.

The density of the molding compounds A was determined in accordance with DIN EN ISO 1183-1:2019-09.

The density of the reinforcing fibers B was determined according to ASTM C693.

The density of the filler C is typically determined according to DIN-ISO 787/10. The melt mass flow rate MFR (melt flow rate) was determined according to DIN EN ISO 1133 at 230° C./2.16 kg for the polymer A1 and at 190° C./0.325 kg for the polar functionalized polymer A2.

The melting point Tm was determined by means of differential scanning calorimetry (DSC) in accordance with DIN EN ISO 11357-3.

The mean linear thermal expansion coefficients a (CLTE, Coefficient of Linear Thermal Expansion) were determined as the arithmetic mean of the values in the longitudinal and transverse directions in accordance with ISO 11359-1 and ISO 11359-2.

The average coefficient of thermal volume expansion Ov was determined according to the equation Ov = 3 * a.

Components A, B, C and D used

Polymer A1 polyolefin

propene-ethene copolymer having a density of 0.898 g/cm ³ to 0.900 g/cm ³ ; a melt mass flow rate MFR (230°C/2.16 kg) of 90 to 110 ml/10 min, mostly 100 ml/10 min; a melting point (DSC) of 135 °C to 159 °C, a thermal expansion coefficient OAI = 60*1 O' ⁶ K' ¹ to 90*1 O' ⁶ K' ¹ , coefficient of thermal volume expansion OV,AI = 3 * OAI = 180*10' ⁶ K' ¹ to 270*1 O' ⁶ K' ¹

Polar Functionalized Polymer A2 Propene Graft Copolymer

(PRIEX® 20093 from BYK-Chemie)

Chemically modified propene graft copolymer (white granules) with grafted maleic anhydride (0.15 to 0.25% by weight) having a density of about 0.9 g/cm ³ . melt mass flow rate MFR (190°C/0.325 kg) 9 g/10 min to 13 g/10 min; Melting point (DSC) 160°C to 165°C.

Continuous reinforcement fiber B glass fiber

(E-glass fibers from Lange + Ritter GmbH)

A glass fiber twill fabric 2/2 with the following properties was used as continuous reinforcement fiber B: size PP-compatible, basis weight 600 g/m ² , 1200 tex roving yarn in warp and weft, 25 threads/10 cm in warp and weft direction, coefficient of thermal expansion QB = 5*1 O' ⁶ K' ¹ to 6*1 O' ⁶ K' ¹ , coefficient of thermal volume expansion OV,B = 3 * OB = 15*10' ⁶ K' ¹ to 18*10' ⁶ K' ¹ (16.5*1 O' ⁶ K' ¹ ), density B = 2.55 g/ml to 2.58 g/ml (2.57 g/ml).

Inorganic filler C

The following fillers C were used:

C1 CaCOs with a mean particle size of 35 pm

(Omyacarb® 30-AV from OMYA)

Coefficient of thermal expansion aci = 10*10 ^-6 K' ¹ , coefficient of thermal volume expansion av,ci = 3 * aci = 30*10' ⁶ K' ¹ , density C1 = 2.3-2.8 g/ml (2, 65g/ml)

C2 Hollow glass spheres with an average particle size of 20 μm

(Glass Bubbles iM16K by 3M™)

Thermal expansion coefficients Oc2 = 8*1 O' ⁶ K' ¹ to 9*1 O' ⁶ K' ¹ , coefficient of thermal volume expansion av,c2 = 3 * Oc2 = 24*10' ⁶ K' ¹ 27*10' ⁶ K ' ¹ (25.5*10 ^-6 K' ¹ ), density C2 = 0.46 g/ml

Additive D Distilled monoglyceride (1-glycerol monostearate, white powder). Dimodan® HP from DuPont Danisco

Matrix composition M

A mixture of the thermoplastic molding composition A (comprising the polymers A1 and A2) and the additive D with the following composition was used as the matrix composition M:

Table 1. Composition of matrix composition M and unfilled thermoplastic composition. The matrix composition M is obtained by intensively mixing components A1, A2, D and C in an extruder. The matrix composition M was provided as a powder and as a film with a thickness of 67 µm and 135 µm. A composition of matter containing filler (M+C) was prepared as film F(M+C) by mixing components A1, A2, D and C and forming into a film having a thickness of 135 µm and 270 µm.

production method

The composite materials V described in Table 1 with a proportion of 40 to 48% by volume of reinforcing fibers B and two layers of the glass fiber twill fabric were produced from the components described above by means of a described hot-pressing process. The process for producing the composite materials V comprises the following process steps, which are explained in more detail below: i) providing at least one sheet G made of continuous reinforcing fibers B: the continuous reinforcing fibers are used as rolled goods and unrolled within the process; ii) providing at least one thermoplastic film from thermoplastic matrix composition M containing the thermoplastic molding compound A and the at least one inorganic filler C; iii) bringing together the thermoplastic matrix composition M containing the thermoplastic molding composition A and the at least one particulate inorganic filler e, with the sheet G of continuous reinforcing fibers B: the matrix composition M and the continuous reinforcing fiber B are in the manners described below at 160-220 °C merged; iv) Impregnation of the continuous reinforcing fiber B with the thermoplastic matrix composition M: the assembled layer structure is pressed in an interval hot press, the structure containing the thermoplastic matrix A, the continuous reinforcing fiber B and the filler C is processed between two steel dividing sheets. The pressing tool is lowered onto the pressing species and raised again, and the species is pulled a little further in the lifting cycle. The pressing tool has a temperature of 200-280 °C. The composite is pressed at 1-3 MPa for 5-40 seconds per stroke; v) Consolidation of the composite V: after the hot-pressing zone, the composite with the separating plates is transferred to a colder zone of the pressing tool. Here the temperature is 80-180 °C. The composite is pressed at 1-3 MPa for 5-40 seconds per stroke. Here, the matrix material is solidified and a finished composite material V is obtained; vi) optional cooling and optional further process steps.

Process steps i) and ii)

Process step i) includes the provision of the glass fiber twill fabric used by laying it out flat. Process step ii) comprises the provision of a film of thermoplastic matrix composition M according to Table 1.

Process step iii) was carried out in two alternative embodiments, which are described below as process steps iii-a) and iii-b).

Process step iii-a) (comparative tests)

The sheet G of continuous reinforcing fibers B was provided flat in its full areal extent. The matrix composition M and optionally the filler C were each applied in the form of powder to the fabric G in one step. The composite was heated using a hot press so that the matrix composition M was bonded to the fabric G and optionally the filler C. Composite V was not fully consolidated at this step.

Process step iii-b) (according to the invention)

The fabric G was provided flat over its full area extent. Films made from Matrix Composition M and Filler C were used. Layer constructions from the fabric G and the films were produced and pressed directly into the fully consolidated composite material V in a hot press.

Process steps iv) + v)

The following tests were carried out on an interval hot press (manufacturer: Teubert Maschinenbau GmbH, type HP007), which is capable of producing a composite material from polymer film, melt or powder, for quasi-continuous production of fiber-reinforced thermoplastic semi-finished products, laminates and sandwich panels.

Characterization of process step iii):

Process step iii) represents the merging of the various components. In each case, an assessment was made of the extent to which adhesions occurred on the pressing tool during the manufacturing process:

1 no buildup on the pressing tool

2 small adhesions on the pressing tool

3 medium adhesions on the pressing tool

4 strong adhesions on the pressing tool

Mechanical characterization of the composites

The flexural modulus E _r and the maximum flexural stress o max according to the 3-point flexural test according to DIN ₁₄₁₂₅ were determined on the composite materials produced. The values were measured in the directions °0° (in the direction of the grain) and 90° (perpendicular to the direction of the grain), respectively. The results are shown in Table 1.

Characterization of the geometric surface shape of the composite material

The geometric surface shape of the composite materials V produced was determined by determining the maximum heights Sz in accordance with the geometric product specification according to DIN EN ISO 25178. Due to the unequal shrinkage behavior of thermoplastic molding compound A and continuous reinforcing fiber B in fabric G, without filler C the textile fiber architecture is visible on the composite surface, the so-called fiber topography. In order to improve the surface quality, ie to reduce the appearance of the textile fiber architecture and thus to minimize the geometric product specification in the form of the maximum height Sz, the fillers C described were added to the thermoplastic molding composition A. In order to measure the resulting surface quality, samples measuring 95×70 mm ² were repeatedly measured and evaluated using the optical white light method (phase stepped deflectometry=PSD). The results are shown in Tables 1 to 5. Results

Composite materials V with different compositions were produced and characterized in the manner described. The filler contents were chosen such that the volume content of filler C in the entire matrix composition M (based on the total volume of components M and C) corresponded to a content of about 50% by volume.

Table 2: Production and testing of composite materials with different layer structures L and process step iii-a), comparative examples C1, C2 and C3.

^[1] Layer structure legend: P(P) = filler-free polymer composition like. Tab. 1 in the form of powder; G = fabric G; P(C1)=powdered filler C1; P(C2) = powder filler C2. " ₇ . 0.1 to 2 ^[3] Bending stress Omax.

Table 3: Production and testing of composite materials with different layer structures L and process step iii-b), examples 1 and 2.

^[1] Layer structure legend: G = fabric G; F(M+C2) = film of matrix composition M with filler C2; behind the film is the respective thickness of the film in μm (135 μm or 270 μm for the films F(M+C2) „ ₇ . 0.1 to 2

^[3] Bending stress Omax.

Examples 1 and 2 are according to the invention, C1 to C3 represent comparative examples. Examples 1 and 2 show that the method according to the invention using films from the matrix composition M gives composite materials V with high surface quality, with the occurrence of adhesions of the filler at the pressing tool during production is significantly reduced. Also, the surface waviness can be reduced four to five times compared to Comparative Example 1. The surface appearance of the composite materials V is thus significantly improved.

Tables 4 and 5 show further examples 3 to 8, which were produced by the process according to the invention, and comparative example C4.

Table 4: Production of thermoplastic fiber-reinforced plastics with different filler contents, examples 3 and 4, comparative example C4.

^[1] Layer structure legend: F(M) = matrix composition M in the form of a film; G = fabric G; F(M+C2) = film comprising matrix composition M and filler C2; behind the film the respective thickness of the film is listed in μm (67 μm or 135 μm for the films F(M); 135 μm or 270 μm for the films F(M+C2) „ ₇ . 0.1 to 2

^[3] Bending stress Omax.

Table 5: Production of thermoplastic fiber-reinforced plastics with different filler contents, examples 5 to 8.

^[3] Bending stress Omax.

The examples according to the invention are characterized by a high surface quality, while the mechanical properties of the composite materials according to the invention

V remain sufficiently good even with comparatively low proportions of thermoplastic molding composition A. The occurrence of adhesions on the pressing tool is significantly reduced during the process implementation.

Claims

patent claims

1. A process for producing a fiber-reinforced, thermoplastic composite material V, comprising: a) a thermoplastic matrix composition M, comprising at least one thermoplastic molding composition A, at least one particulate, inorganic filler C and optionally at least one additive D; and b) at least one continuous reinforcement fiber B; the method comprising at least the following method steps: i) providing the at least one continuous reinforcing fiber B; ii) providing at least one thermoplastic matrix composition M obtained by mixing the at least one thermoplastic molding composition A, the at least one particulate, inorganic filler C and optionally the at least one additive D; iii) combining the thermoplastic matrix composition M with the at least one continuous reinforcing fiber B; iv) impregnation of the at least one continuous reinforcing fiber B with the thermoplastic matrix composition M to obtain a composite material V; v) consolidation of the composite V obtained; vi) optional solidification and/or optional further process steps; characterized in that in process step iii) the thermoplastic matrix composition M containing the particulate, inorganic filler C is brought together in the form of a thermoplastic film with the at least one continuous reinforcing fiber B, the thermoplastic matrix composition M being 20 to 80% by volume, preferably 20 to 70% by volume, in particular 30 to 60% by volume, of which at least one particulate, inorganic filler e consists.

2. A process for producing a fiber-reinforced, thermoplastic composite material V according to claim 1, wherein in process step iii) the thermoplastic film has an average thickness of 25 to 500 μm. Process for producing a fiber-reinforced, thermoplastic composite material V according to claim 1 or 2, wherein the particulate, inorganic filler C has a thermal expansion coefficient in the range from 2*io- ⁶ K' ¹ to 20*1 O' ⁶ K' ¹ . Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of Claims 1 to 3, process step iii) being carried out at a temperature of at least 160°C, preferably at a temperature of 160 to 280°C. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of Claims 1 to 4, process step iv) being carried out at a temperature of at least 180°C, preferably at a temperature of 200 to 290°C. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of Claims 1 to 5, process step iv) being carried out at an elevated pressure in a range from 1 to 3 MPa. Process for the production of a fiber-reinforced, thermoplastic composite material V according to at least one of Claims 1 to 6, in which the thermoplastic matrix composition M contains >5 to <20 parts by weight, preferably >10 to <20 parts by weight, of the thermoplastic molding composition A, > 1 to <60 parts by weight, preferably >5 to <40 parts by weight, of the at least one particulate, inorganic filler C, and >0 to <10 parts by weight of the at least one additive D. A method for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 7, wherein the fiber-reinforced, thermoplastic composite material V comprises the following components, or consists of: a)> 5 to <20 wt .-% of a thermoplastic molding compound A; b) >20 to <80% by weight of the at least one reinforcing fiber B; c) > 1 to < 60% by weight of the at least one inorganic filler C, and d) > 0 to < 10% by weight of the at least one further additive D, where the information in % by weight is based on the total fiber-reinforced, thermoplastic composite V are based and the sum of components A, B, C, and D 100 wt .-% result. A process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 8, wherein the thermoplastic molding composition A comprises at least one thermoplastic polymer A1 and optionally at least one polar functionalized polymer A2, comprising at least repeating units of at least one functional monomer A2-I. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 9, wherein the thermoplastic molding composition A comprises (and preferably consists of) the following components: a-1) 50 to 99.9% by weight, preferably 70 to 99.9% by weight, particularly preferably 79 to 98% by weight, particularly preferably 90 to 97% by weight, of a thermoplastic polymer A1; a-2) 0.1 to 20% by weight, preferably 0.1 to 10% by weight, particularly preferably 1 to 8% by weight, particularly preferably 3 to 7% by weight, of the at least one polar functionalized polymer A2; a-3) 0 to 49.9% by weight, preferably 0 to 29.9% by weight, more preferably 1 to 20% by weight, of at least one further polymer A3; where the polymers A1, A2 and A3 are different from one another, and where the percentages by weight are in each case based on the total weight of the thermoplastic molding composition A and the sum of the components A1, A2 and A3 is 100% by weight. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 10, wherein the particulate, inorganic filler C has a density of 0.2 to 2.8 g/ml and an average particle size of less than 70 μm. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 11, wherein the particulate, inorganic filler e comprises hollow glass spheres and/or calcium carbonate. A process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 1 to 12, wherein the thermoplastic matrix composition M comprises at least one mold release agent as additive D. Process for producing a fiber-reinforced, thermoplastic composite material V according to at least one of claims 9 or 10, wherein the polar functionalized polymer A2 is a graft copolymer of polypropylene and maleic anhydride with a maleic anhydride content of 0.1 to 5% by weight, based on the total weight of the polar functionalized polymer A2. Fibre-reinforced, thermoplastic composite material V obtained according to at least one of Claims 1 to 14.