USE OF FIBRE COMPOSITE MATERIAL HAVING SANDWICH STRUCTURE AND FOAM COMPONENT

Abstract

The use of a fibre composite material W having a sandwich structure, constructed from: A) a thermoplastic material layer w, containing as components: a) a thermoplastic moulding compound A as a matrix, b) a ply made from reinforcing fibres B, and c) optionally additive C, wherein the ply of reinforcing fibres B is embedded in the matrix of the thermoplastic moulding compound A, and, in the production of the material layer w, the thermoplastic moulding compound A comprises at least one chemically reactive functionality, which reacts with chemical groups of the surface of the reinforcing fibres B; and B) a further thermoplastic layer T and/or a foam layer S, wherein said further layer T and/or S is permanently connected to the material layer w; provides increased mechanical stability for the production of moulded parts.

Claims

1-16. (canceled)

17. A method for production of moldings, comprising forming a fiber composite material W with sandwich structure from: A) at least one thermoplastic material layer w, comprising, as components in the production, a) at least one thermoplastic molding compound A as matrix, b) at least one ply of reinforcing fibers B, and c) optionally at least one additive C, wherein the at least one ply of the reinforcing fibers B has been embedded into the matrix of the thermoplastic molding compound A, and wherein the thermoplastic molding compound A, in the production of the material layer w, has at least one chemically reactive functionality that reacts with chemical groups on the surface of the reinforcing fibers B; and B) at least one further thermoplastic layer T other than the layer w, at least one foam layer S or a combination of T and S, said further layer T, S, or a combination of T and S having been permanently bonded to the material layer w.

18. The method as claimed in claim 17, formed from: A) 10% to 70% by weight of thermoplastic material layer w, comprising a) 30% to 95% by weight of the thermoplastic molding compound A, b) 5% to 70% by weight of the reinforcing fibers B, and c) 0% to 40% by weight of at least one additive C, and B) 30% to 90% by weight of at least one thermoplastic layer T, at least one foam layer S, or a combination of T and S.

19. The method as claimed in claim 17, wherein the thermoplastic molding compound A is amorphous and is based on a styrene copolymer modified by a chemically reactive functionality.

20. The method as claimed in claim 17, wherein the thermoplastic molding compound A is selected from the group of copolymers modified by a chemically reactive functionality consisting of: styrene-acrylonitrile copolymers, -methylstyrene-acrylonitrile copolymers, impact modified acrylonitrile-styrene copolymers, and blends of the copolymers mentioned with polycarbonate or polyimide.

21. The method as claimed in any of claim 17, wherein the chemically reactive functionality of the thermoplastic molding compound A is based on components selected from the group consisting of maleic anhydride, N-phenylmaleimide, and glycidyl (meth)acrylate.

22. The method as claimed in claim 17, wherein the thermoplastic molding compound A comprises from 0.1% to 10% by weight of monomers (A-1), based on the amount of component A, said monomers having a chemically reactive functionality.

23. The method as claimed in claim 17, wherein the reinforcing fibers B comprise, at the surface, one or more chemically reactive functionalities from the group of hydroxyl, ester, and amino groups.

24. The method as claimed in claim 17, wherein the reinforcing fibers B consist of glass fibers comprising silanol groups on the surface as chemically reactive functionality.

25. The method as claimed in claim 17, wherein the reinforcing fibers B are used in the form of a scrim, a weave, a mat, a nonwoven, or a knit in a maleic anhydride-modified styrene copolymer as molding compound A.

26. The method as claimed in claim 17, wherein the material layer w has a thickness of <100 mm.

27. The method as claimed in claim 17, wherein the material layer w has a ribbed structure.

28. The method as claimed in claim 17, wherein the material layer w comprises more than three layers.

29. The method as claimed in claim 17, wherein the at least one thermoplastic layer T, at least one foam layer S, or a combination of T and S has been bonded to the material layer w by lamination or (co)extrusion.

30. The method as claimed in claim 17, wherein the thermoplastic layer T has been reinforced with at least one short, long, or endless fiber S.

31. A fiber composite material W with sandwich structure, comprising: A) at least one thermoplastic material layer w, comprising, as components in the production, a) at least one thermoplastic molding compound A as matrix, b) at least one ply of reinforcing fibers B, and c) optionally at least one additive C, wherein the at least one ply of reinforcing fibers B has been embedded into the matrix of the thermoplastic molding compound A, and wherein the thermoplastic molding compound A in the production of the material layer w has at least one chemically reactive functionality that reacts with chemical groups on the surface of the reinforcing fibers B; and B) at least one further thermoplastic layer T other than the layer w, at least one foam layer S, or a combination of T and S, said further layer T, S, or a combination of T and S having been permanently bonded to the material layer w.

32. The method as claimed in claim 17, formed from: A) 10% to 70% by weight of thermoplastic material layer w, comprising a) 30% to 95% by weight of the thermoplastic molding compound A, b) 5% to 70% by weight of the reinforcing fibers B, and c) 0% to 40% by weight of at least one additive C, and B) 30% to 90% by weight of at least one thermoplastic layer T, at least one foam layer S, or a combination of T and S, wherein the reinforcing fibers B are used in the form of a scrim, a weave, a mat, a nonwoven, or a knit in a maleic anhydride-modified styrene copolymer as molding compound A, and wherein the material layer w optionally comprises more than three layers.

33. The method as claimed in claim 17, wherein the material layer w has a thickness of <10 mm.

34. The method as claimed in claim 17, wherein the material layer w has a thickness of <5 mm.

35. The method as claimed in claim 17, wherein the thermoplastic molding compound A is selected from the group of copolymers modified by a chemically reactive functionality consisting of: styrene-acrylonitrile copolymers, -methylstyrene-acrylonitrile copolymers, acrylonitrile-butadiene-styrene copolymers (ABS), and acrylonitrile-styrene-acrylic ester copolymers (ASA), and blends of the copolymers mentioned with polycarbonate or polyamide.

36. The method as claimed in claim 30, wherein the fibers S are carbon fibers or basalt fibers.

Description

FIGURES

[0252] FIG. 1 shows the fiber composite material layers w which have been obtained according to experiment no. 1. FIG. 1A shows the visual documentation. FIG. 1B shows the microscope view of a section through the laminar fiber composite material layer w arranged in horizontal alignment (on the left: 25-fold magnification, on the right: 50-fold magnification), the fibers being clearly apparent as a horizontal dark-colored layer between the light-colored layers of thermoplastic molding compound. FIG. 1C shows the 200-fold magnification, it being apparent that the impregnation is incomplete at some points.

[0253] FIG. 2 shows the fiber composite material layers w which have been obtained according to experiment no. 2. FIG. 2A shows the visual documentation. FIG. 2B shows the microscope view of a section through the laminar fiber composite material layer w arranged in horizontal alignment (on the left: 25-fold magnification, on the right: 50-fold magnification), the fibers being clearly apparent as a horizontal dark-colored layer between the light-colored layers of thermoplastic molding compound. FIG. 2C shows the 200-fold magnification, it being apparent that the impregnation is partially incomplete.

[0254] FIG. 3 shows the fiber composite material layers w which have been obtained according to experiment no. 3. FIG. 3A shows the visual documentation. FIG. 3B shows the microscope view of a section through the laminar fiber composite material layer w arranged in horizontal alignment (on the left: 25-fold magnification, on the right: 50-fold magnification), with no apparent layer of fibers. FIG. 3C shows the 200-fold magnification, it being apparent that the impregnation is substantially complete.

[0255] FIG. 4 shows the fiber composite material layers w which have been obtained according to experiment no. 4. FIG. 4A shows the visual documentation. FIG. 4B shows the microscope view of a section through the laminar fiber composite material layer w arranged in horizontal alignment (on the left: 25-fold magnification, on the right: 50-fold magnification), with no apparent layer of fibers. FIG. 4C shows the 200-fold magnification, it being apparent that the impregnation is incomplete at individual points.

[0256] FIG. 5 shows the fiber composite material layers w which have been obtained according to experiment no. 5. FIG. 5A shows the visual documentation. FIG. 5B shows the microscope view of a section through the laminar fiber composite material layer w arranged in horizontal alignment (on the left: 25-fold magnification, on the right: 50-fold magnification), with no apparent layer of fibers. FIG. 4C shows the 200-fold magnification, it being apparent that the impregnation is incomplete at a few points.

[0257] FIG. 6 shows the production of the fiber composite material layers w (here: glass fiber weave) in the press intake V25-V28. It is clearly apparent that a production process of this kind permits continuous production. Moreover, it is apparent via the embossment of the pattern that the fiber composite material layer w is also three-dimensionally formable.

[0258] FIG. 7 shows, in schematic form, the development of undesired formation of surface waves (texture).

[0259] The invention is described in detail in the examples, figures and claims which follow.

EXAMPLES

[0260] The experiments which follow were conducted in a commercial intermittent hot press capable of producing a fiber/film composite from polymer film, melt or powder, for quasi-continuous production of fiber-reinforced thermoplastic semifinished products, laminates and sandwich sheets.

[0261] Sheet width: 660 mm

[0262] Laminate thickness: 0.2 to 9.0 mm

[0263] Laminate tolerances: max.0.1 mm corresponding to semifinished product

[0264] Sandwich sheet thickness: max. 30 mm

[0265] Output: about 0.1-60 m/h, depending on quality and component thickness

[0266] Nominal advance rate 5 m/h

[0267] Mold pressure: compression unit 5-25 bar, infinitely adjustable for minimum and maximum mold size (optional)

[0268] Mold temperature control: 3 heating zones and 2 cooling zones

[0269] Mold temperature: up to 400 C.

[0270] Mold length: 1000 mm

[0271] Press opening distance: 0.5 to 200 mm

[0272] Preferred direction of production: from right to left

[0273] Technical data of the melt plastification are:

[0274] Discontinuous melt discharge in center position for production of fiber-reinforced thermoplastic semifinished products:

[0275] Screw diameter: 35 mm

[0276] Max. stroke volume: 192 cm.sup.3

[0277] Max. screw speed: 350 rpm

[0278] Max. discharge flow rate: 108 cm.sup.3/s

[0279] Max. discharge pressure: 2406 bar (specific)

[0280] The described fiber composite materials W (organosheets) with sandwich structures, comprising material layer w, especially with an amorphous thermoplastic matrix, are particularly suitable for the production of moldings. Some examples are detailed hereinafter.

[0281] Unless stated otherwise, the moldings are produced by injection molding.

[0282] Production of the Material Layer m

[0283] 40% by weight, based on the material layer, of an acrylonitrile-styrene-maleic anhydride copolymer as thermoplastic molding compound A (produced from: 75% by weight of styrene, 24% by weight of acrylonitrile and 1.0% by weight of maleic anhydride) is compounded with

[0284] 60% by weight, based on the material layer, of a glass-based reinforcing fiber having chemically reactive functionality (silane groups) on the surface [GW 123-580K2 from P-D Glasseiden GmbH].

[0285] Production of the Material Layer n

[0286] 65% by weight, based on the material layer, of an acrylonitrile-butadiene-styrene copolymer as thermoplastic molding compound A (ABS prepared from: 45% by weight of butadiene, 30% by weight of styrene, 24% by weight of acrylonitrile and 1% by weight of maleic anhydride) is compounded with

[0287] 35% by weight, based on the material layer, of a glass-based reinforcing fiber having chemically reactive functionality (silane groups) on the surface [GW 123-580K2 from P-D Glasseiden GmbH]. The material layer is subsequently provided with a ribbed structure.

Example 1: Production of a Fiber Composite Material with Sandwich Structure, Comprising Material Layer m

[0288] The material m is coextruded with an expanded polystyrene (X-PS; produced from 158 K polystyrene with CO.sub.2/ethanol as blowing agent) on a tandem extruder with a thickness of 10 mm, in order to obtain a sandwich structure.

[0289] The fiber composite material with sandwich structure obtained has a sequence of m/X-PS/m.

Example 2: Production of an Organosheet Sandwich Structure Comprising Material Layer n

[0290] The material n is coextruded with an expanded polystyrene (X-PS; produced from 158 K polystyrene with CO.sub.2/ethanol as blowing agent) on a tandem extruder with a thickness of 10 mm, in order to obtain a sandwich structure.

[0291] The fiber composite material with sandwich structure obtained has a sequence of: n/X-PS/n.

[0292] The inventive organosheets with sandwich structures from examples 1 and 2 are more robust compared to the corresponding organosheets without sandwich structure m and n.

Further Examples for Production of the Thermoplastic Fiber Composite Material Layer w

[0293] Thermoplastic Combinations a Run: [0294] A1 (comparison):S/AN with 75% styrene (S) and 25% acrylonitrile (AN), viscosity number 60, Mw 250 000 g/mol (measured via gel permeation chromatography on standard columns with monodisperse polystyrene calibration standards) [0295] A2: S/AN/maleic anhydride copolymer with the composition (% by weight): 74/25/1, Mw 250 000 g/mol (measured via gel permeation chromatography on standard columns with monodisperse polystyrene calibration standards) [0296] A3: mixture of A2:A1=2:1 [0297] A4: mixture of A2:A1=1:2

[0298] Fiber Textiles B Used: [0299] B1: bidirectional glass fiber scrim 0/90 (GF-GE) with basis weight=590 g/m.sup.2, [0300] weft+warp=1200 tex [for example KN G 590.1 from P-D Glasseiden GmbH] [0301] B2: glass fiber weave, 2/2 twill (GF-KG) with basis weight=576 g/m.sup.2, weft+warp=1200 tex

[0302] The combinations and parameter settings run in connection with experiments no. 1-5 are listed in the following table:

TABLE-US-00001 TABLE 1 Production conditions for the fiber composite material layers w Experi- Thick- ment Com- Pressure Pressing ness no. posite* Temperature profile (bar) time (s) (mm) 1 (comp.) A1 + B1 220-240-260-160-80 20 20 1 2 (comp.) A1 + B1 220-280-300-160-80 25 30 1 3 A2 + B1 240-300-320-160-80 20 20 1 4 A3 + B1 240-300-320-160-80 20 30 1 5 A4 + B1 240-300-320-160-80 20 30 1 *Components A + B1: textile construction thickness 0.465 mm, matrix construction thickness 0.653 mm, total matrix volume: 22 mL, proportion by volume of fibers: 41.6%, overall semifinished product density: 1.669 g/mL, total semifinished product thickness: 1.117 mm

Experiment No. 1 (Comparative Experiment)

[0303] The results are shown in FIG. 1.

[0304] Visual assessment at the semifinished product surface:

[0305] Macroimpregnation: complete

[0306] Microimpregnation: clearly incomplete

[0307] Microscopic assessment within the semifinished product:

[0308] Matrix layer in middle ply: clearly apparent

[0309] Matrix layer in the outer ply: not apparent in the roving

[0310] Impregnated warp threads: unimpregnated regions in the middle, lightly impregnated at the circumference

[0311] Impregnated weft threads: clearly unimpregnated regions in the middle, lightly impregnated at the circumference

[0312] Air pockets: few, in the roving only

[0313] Consolidation: inadequate, damage to warp and weft threads

Experiment No. 2

[0314] The results are shown in FIG. 2.

[0315] Visual assessment at the semifinished product surface:

[0316] Macroimpregnation: complete

[0317] Microimpregnation: incomplete at several points

[0318] Microscopic assessment within the semifinished product:

[0319] Matrix layer in middle ply: apparent

[0320] Matrix layer in the outer ply: indistinct at the roving

[0321] Impregnated warp threads: unimpregnated regions in the middle apparent, partly impregnated and partly unimpregnated at the circumference

[0322] Impregnated weft threads: unimpregnated regions in the middle, lightly impregnated at the circumference

[0323] Air pockets: few

[0324] Consolidation: insufficient, distinct damage to weft threads

Experiment No. 3

[0325] The results are shown in FIG. 3.

[0326] Visual assessment at the semifinished product surface: Macroimpregnation: complete

[0327] Microimpregnation: complete

Experiment No. 3, Microscopic Assessment within the Semifinished Product

[0328] Matrix layer in middle ply: not apparent

[0329] Matrix layer in the outer ply: clearly apparent

[0330] Impregnated warp threads: barely any unimpregnated regions apparent, well-impregnated at the circumference

[0331] Impregnated weft threads: barely any unimpregnated regions apparent, well-impregnated at the circumference

[0332] Air pockets: a very large number of large bubbles apparent

[0333] Consolidation: good, no damage

Experiment No. 4

[0334] The results are shown in FIG. 4.

[0335] Visual assessment at the semifinished product surface:

[0336] Macroimpregnation: complete

[0337] Microimpregnation: predominantly complete

[0338] Microscopic assessment within the semifinished product:

[0339] Matrix layer in middle ply: barely apparent

[0340] Matrix layer in the outer ply: apparent

[0341] Impregnated warp threads: lightly unimpregnated regions apparent, well-impregnated at the circumference

[0342] Impregnated weft threads: unimpregnated regions apparent, but impregnated at the circumference

[0343] Air pockets: none apparent

[0344] Consolidation: satisfactory, moderate damage to weft threads apparent

Experiment No. 5

[0345] The results are shown in FIG. 5.

[0346] Visual assessment at the semifinished product surface:

[0347] Macroimpregnation: complete

[0348] Microimpregnation: predominantly complete

[0349] Microscopic assessment within the semifinished product:

[0350] Matrix layer in middle ply: not apparent

[0351] Matrix layer in the outer ply: apparent

[0352] Impregnated warp threads: few unimpregnated regions apparent, well-impregnated at the circumference

[0353] Impregnated weft threads: few unimpregnated regions apparent, well-impregnated at the circumference

[0354] Air pockets: none apparent

[0355] Consolidation: partly good, partly inadequate, local damage to weft threads apparent

Summary of the Experimental Results

[0356]

TABLE-US-00002 TABLE 2 Summary of experiments and assessment Maleic anhydride Max. Experiment concentration temperature Impregnation** no. Composite* (% by wt.) ( C.) Macro Micro Consolidation** 1 (comp.) A1 + B1 0 260 1 5 5 2 (comp.) A1 + B1 0 300 1 4 4 3 A2 + B1 1 320 1 1 2 4 A3 + B1 0.66 320 1 2 3 5 A4 + B1 0.33 320 1 2 4 *Components A + B1: textile construction thickness 0.465 mm, matrix construction thickness 0.653 mm, total matrix volume: 22 mL, proportion by volume of fibers: 41.6%, overall semifinished product density: 1.669 g/mL, total semifinished product thickness: 1.117 mm **1 = perfect, 2 = good, 3 = partial, 4 = little, 5 = poor/zero

TABLE-US-00003 TABLE 3 Comparison of the inventive experimental settings with conventional organosheets Maleic Experi- anhydride Printability ment concentration Surface with 45 no. Composite (% by wt.) quality* mdyne ink** 1 (comp.) A1 + B1 0 2 1 2 (comp.) A1 + B1 0 2 1 3 A2 + B1 1 1-2 1 4 A3 + B1 0.66 1-2 1 5 A4 + B1 0.33 1-2 1 6 bond laminates 0 4-5 1 composite composed of about 60% glass fiber weave and 40% polyamide 7 composite 0 4-5 5 composed of about 60% glass fiber weave and 40% polyamide *1 = completely smooth, 2 = substantially smooth, 3 = slightly rough, 4 = moderately rough, 5 = fibers clearly perceptible **1 = perfect, 2 = good, 3 = partial, 4 = little, 5 = poor/zero

Experiment No. 6

[0357] The results are shown in table 5.

[0358] The combinations and parameter settings run in connection with experiment no. 6 are listed in the following table:

TABLE-US-00004 TABLE 4 Production conditions of the fiber composite material layers w Experi- Tem- ment perature Pressure Pressing Thickness no. Composite* profile (bar) time (s) (mm) 4 A1 + B1 220-240-300-160- 20 20 1 80 12 A3 + B1 220-240-300-160- 20 20 1 80 28 A1 + B2 240-300-320-160- 20 20 1 80 26 A3 + B2 240-300-320-160- 20 30 1 80 *Components A + B1: textile construction thickness 0.465 mm, matrix construction thickness 0.653 mm, total matrix volume: 22 mL, proportion by volume of fibers: 41.6%, overall semifinished product density: 1.669 g/mL, total semifinished product thickness: 1.117 mm

TABLE-US-00005 TABLE 5 Comparison of flexural strength. Experiment no. 8 9 10 11 scrim (B1), warp 2/2 twill Reinforcement direction Delta weave (B2) Delta Matrix A1 A3 (%) A1 A3 (%) Flexural test: Modulus (GPa) 19.7 22.5 14 21.1 19.6 7 Breaking stress (MPa) 211 462 119 423 528 25

[0359] Table 5 shows the fiber composite material layers w (or fiber composite materials W) obtained in a test series. In each case, pure SAN (A1) and an S/AN/maleic anhydride copolymer (A2) were combined with a commercial scrim and weave reinforcement in an identical process and tested. The fiber volume content of the composites was 42%.

[0360] The improved quality of the impregnation and bonding between fiber and matrix is not shown in the flexural stiffness, but is clearly shown in the flexural strength (breaking stress) of the samples examined.

[0361] Examples of Multilayer Organosheets

[0362] The fiber composite material layers w (organosheets) described, especially with an amorphous thermoplastic matrix, are particularly suitable for the production of molded articles, films and coatings. Some examples are adduced hereinafter. Unless stated otherwise, the moldings are produced by injection molding.

Example 1: Production of the Fiber Composite Material M

[0363] 40% by weight, based on the fiber composite material layers w, of an acrylonitrile-styrene-maleic anhydride copolymer as thermoplastic molding compound A (produced from: 75% by weight of styrene, 24% by weight of acrylonitrile and 1% by weight of maleic anhydride) is compounded with

[0364] 60% by weight, based on the fiber composite material layer w, of a glass-based reinforcing fiber with chemically reactive functionality (silane groups) at the surface [GW 123-580K2 from P-D Glasseiden GmbH].

Example 2: Production of the Fiber Composite Material Layer N

[0365] 65% by weight, based on the fiber composite material layer w, of an acrylonitrile-butadiene-styrene copolymer as thermoplastic molding compound A (ABS produced from: 45% by weight of butadiene, 30% by weight of styrene, 24% by weight of acrylonitrile and 1% by weight of maleic anhydride) is compounded with 35% by weight, based on the fiber composite material layer w, of a glass-based reinforcing fiber with chemically reactive functionality (silane groups) at the surface [GW 123-580K2 from P-D Glasseiden GmbH]. The fiber composite material layer w is subsequently provided with a ribbed structure.

Example 3: Production of Moldings from the Fiber Composite Material Layers M and N

Example A: Washing Machine Windows

Example B: Lens Covers

[0366] An elevated stiffness of the window and the lens cover is observed compared to corresponding materials consisting of glass. Moreover, the organosheets are less sensitive to scratches and pressure.

[0367] Further Flexural Stress Experiments on Fiber Composite Materials Reinforced with Sheetlike Structures

[0368] The components are as defined above. Flexural stress and flexural modulus were determined according to DIN 14125:2011-05.

[0369] The combinations and parameter settings for the process described in claim 1 are listed in the following table:

TABLE-US-00006 TABLE 6 Compositions of comp. 1, comp. 2, comp. 10 and comp. 15 and of the inventive compositions V3 to V9 and V11 to V14. X: proportion by weight of component A:B = 60:40 No. A1 A2 A3 A4 B1 B2 T [ C.] t [s] Comp. 1 X X 260 20-30 Comp. 2 X X 300 30-30 V3 X X 280 20-30 V4 X X 280 40 V5 X X 320 30-30 V6 X X 300 20-30 V7 X X 320 20-30 V8 X X 310 20-30 V9 X X 320 20-30 Comp. 10 X X 320 20-30 V11 X X 320 20-30 V12 X X 320 20-30 V13 X X 320 20-30 V14 X X 320 20-30 Comp. 15 X X 320 20-30

[0370] Table 6 shows the conditions in the experiments conducted.

[0371] In this context, the reactants and the temperature and pressing time were varied. The pressure in all the test series was about 20 bar.

TABLE-US-00007 TABLE 7 Mean values for maximum flexural stress in warp and weft direction for the organosheets produced according to the mixtures comp. 2, V5, V7, V9, comp. 10, V12 to V14 and comp. 15, with a production temperature in each case of at least 300 C. Mean values for maximum No. Fiber direction flexural stress [MPa] Comp. 2 warp direction 211.23 weft direction 184.94 V5 warp direction 670.48 weft direction 271.05 V7 warp direction 590.98 weft direction 301.21 V9 warp direction 371.73 weft direction 244.62 Comp. 10 warp direction 319.8 weft direction 236.01 V12 warp direction 556.15 weft direction 484.24 V13 warp direction 528.96 weft direction 386.83 V14 warp direction 513.95 weft direction 413.86 comp. 15 warp direction 423.03 weft direction 301.40

[0372] The values shown in table 7 are the mean value of 9 measurements in each case.

[0373] Table 7 shows that the inventive organosheets V5, V7, V9, V12, V13 and V14 have a higher mean maximum flexural stress than the organosheets having a matrix comprising 75% by weight of styrene (S) and 25% by weight of acrylonitrile (AN) (comp. 10 and comp. 15). The comparison of V9 with comp. 10 also shows that, under the same conditions (T=320 C. and t=30 s), the organosheet of the invention has greater flexural stress both in warp direction and in weft direction.

[0374] It is found that the process for producing the fiber composite material layer w (and hence of the entire fiber composite material W as well) with a thermoplastic molding compound A and reinforcing fibers B can give improved products.

[0375] Further Examination of Multilayer Fiber Composite Materials

[0376] Technical Data of the Intermittent Hot Press (IVHP):

[0377] Quasi-continuous production of fiber-reinforced semifinished products, laminates and sandwich sheets

[0378] Sheet width: 660 mm

[0379] Laminate thickness: 0.2 to 9.0 mm

[0380] Laminate tolerances: max.0.1 mm corresponding to semifinished product

[0381] Sandwich sheet thickness: max. 30 mm

[0382] Output: about 0.1-60 m/h, depending on quality and component thickness

[0383] Nominal advance rate 5 m/h

[0384] Mold pressure: press unit 5-25 bar, infinitely adjustable for minimum and maximum mold size (optional)

[0385] Mold temperature control: 3 heating and 2 cooling zones

[0386] Mold temperature: up to 400 C.

[0387] Mold length: 1000 mm

[0388] Press opening distance: 0.5 to 200 mm

[0389] Production direction: from right to left

[0390] Technical Data of the Melt Plastification:

[0391] Discontinuous melt discharge in center position for production of fiber-reinforced thermoplastic semifinished products:

[0392] Screw diameter: 35 mm

[0393] Max. stroke volume: 192 cm.sup.3

[0394] Max. screw speed: 350 rpm

[0395] Max. discharge flow rate: 108 cm.sup.3/s

[0396] Max. discharge pressure: 2406 bar (specific)

[0397] Here:

[0398] Melt volume: 22 ccm

[0399] isobaric=pressure-controlled pressing operation

[0400] isochoric=volume-control pressing operation

[0401] T [ C.]=temperature of the temperature zones* (*the press has 3 heating and 2 cooling zones, specified in production direction)

[0402] p [bar]=pressure per cycle: isochoric 20

[0403] s [mm]=distance limit for compression thickness: 1.1 mm

[0404] Temperature profile: (i) 210 to 245 C., so about 220 C. [0405] (ii) 300 to 325 C., so about 300 C. [0406] (iii) 270 to 320 C., so about 280 to 320 C. [0407] (iv) 160 to 180 C. [0408] (v) 80 C.

[0409] t [sec]=pressing time per cycle: 20-30 s

[0410] Construction/lamination: 6-ply construction with middle melt layer; production process: direct melt (SD)

[0411] Matrix Components A:

[0412] M1 (SAN type): styrene-acrylonitrile-maleic anhydride (SAN-MA) terpolymer (S/AN/MA: 74/25/1) with an MA content of 1% by weight and an MVR of 22 cm.sup.3/10 min at 220 C./10 kg (measured to ISO1133);

[0413] M1b corresponds to the aforementioned component M1, with an additional 2% by weight of industrial black mixed into the matrix.

[0414] M2 (SAN type): styrene-acrylonitrile-maleic anhydride (SAN-MA) terpolymer (S/AN/MA: 73/25/2.1) with an MA content of 2.1% by weight and an MVR of 22 cm.sup.3/10 min at 220 C./10 kg (measured to ISO1133);

[0415] M2b corresponds to the aforementioned component M2, with an additional 2% by weight of industrial black mixed into the matrix.

[0416] M3 (SAN type): blend of 33% by weight of M1 and 67% by weight of the SAN copolymer Luran VLN, so 0.33% by weight of maleic anhydride (MA) in the overall blend;

[0417] M3b corresponds to the aforementioned component M3, with an additional 2% by weight of industrial black mixed into the matrix.

[0418] PA6: semicrystalline, free-flowing polyamide Durethan B30S

[0419] PD(OD): free-flowing amorphous optical grade polycarbonate for optical discs;

[0420] Fiber Components B:

[0421] Glass filament twill weave (brief designations: GF-KG(LR) or LR), 2/2 twill weave, basis weight 290 g/m.sup.2, EC9 68 tex rovings, TF-970 finish, supply width 1000 mm (type: 01102 0800-1240; manufacture: Hexcel, obtained from: Lange+Ritter)

[0422] Glass filament twill weave (brief designations: GF-KG(PD) or PD), 2/2 twill weave, basis weight 320 g/m.sup.2, 320 tex rovings, 350 finish, supply width 635 mm (type: EC14-320-350, manufacturer and supplier: PD Glasseide GmbH Oschatz)

[0423] Glass filament scrim (brief designations: GF-GE(Sae) or Sae) 0/45/90/45, basis weight 313 g/m.sup.2, 300 tex main rovings, PA size finish, supply width 655 mm (type: X-E-PA-313-655, no. 7004344, manufacturer and supplier: Saertex GmbH & Co. KG)

[0424] Sae n.s.=300 g/m.sup.2 glass filament scrim, manufacturer designation: Saertex new sizing, +45/45/+45/45

[0425] Glass fiber nonwoven (brief designation: GV50), basis weight 50 g/m.sup.2, fiber diameter 10 m, supply width 640 mm (type: Evalith S5030, manufacturer and supplier: Johns Manville Europe)

[0426] Visual Assessment

[0427] All the fiber composite materials produced were producible in each case as flat organosheets (with a large area) in a continuous process, and it was possible without any problem to cut these to size (in laminatable, customary transport dimensions, for instance 1 m0.6 m). In the case of the transparent fiber composite materials, the embedded fiber material was just apparent on detailed backlit inspection. In the case of the fiber composite materials with a (black-)colored matrix, the embedded fiber material was not/barely apparent even on closer backlit visual inspection.

[0428] Microscope Assessment

[0429] In this case, defects (craters, dips, etc.) were assessed via epiluminescence microscopy, and the surface quality via confocal laser scanning microscopy (LSM). By means of LSM, a top view of a three-dimensional (3D) survey (7.2 mm7.2 mm) of the local measurement region and a two-dimensional (2D) representation of the differences in height after scaling and use of various profile filters were created. Measurement errors and general distortion/skewness of the sample were compensated for by the use of profile filters (noise filters and tilt filters). The 2D high profile of the image was converted to line profiles via defined measurement lines by integrated software and evaluated with computer assistance.

[0430] Fiber composite materials each having four plies of the appropriate sheetlike structure of fibers (GF-KG(PD)(4) or Sae(4) here) embedded into the respective matrix were produced. In order to further increase the comparability of the samples, a thin glass fiber nonwoven (GV50, see above) was applied to each side of the fiber composite materials produced. This had no noticeable effect on the mechanical properties.

[0431] The mean wave depth (MW Wt) and the median roughness (Ra) were ascertained for numerous fiber composite materials. It was found that the MW Wt for all fiber composite materials in which the matrix comprises a functional component that can react with the fibers is distinctly <10 m, whereas in the case of fiber composite materials with comparable PA6 and PD(OD) matrices it is distinctly <10 m. The median roughness values ascertained were also much less for fiber composite materials of the invention. This is shown by way of example by the measured values below.

TABLE-US-00008 TABLE 8 Test results of the LSM analysis with SAN matrix system - wave depth (Wt) and median roughness (Ra) SAN(1) PC(1) PA6(1) +GF-KG(PD)(4) Construction M1b + M2 + M2b + M3b + PC(OD)+ PA6+ Components PD PD PD PD PD PD MW Wt 7.141 7.187 5.181 5.425 11.745 12.323 MW Ra 3.995 4.415 4.17 3.451 6.406 4.968

[0432] This likewise became clear when a scrim (such as Sae) was used in place of the weave:

TABLE-US-00009 TABLE 9 Test results of the LSM analysis with SAN matrix system - wave depth (Wt) and median roughness (Ra) Construction SAN(1) PA6(1) Construction +Sae(4) Components M1b + Sae M2b + Sae MW Wt 5.535 5.205 17.05 MW Ra 4.261 4.24 4.861

[0433] In further tests, strength in warp direction and in weft direction was examined separately. It was shown that the fiber composite materials are very stable both in warp direction and in weft direction. The fiber composite materials are generally even more stable in warp direction than in weft direction.

[0434] Mechanical Properties

[0435] Matrix Components A

[0436] The matrix components A are as described above.

[0437] Fiber components B (if not described above)

[0438] FG290=glass filament weave 290 g/m.sup.2, manufacturer designation: Hexcel HexForce 01202 1000 TF970

[0439] FG320=glass filament weave 320 g/m.sup.2, manufacturer designation: PD Glasseide GmbH Oschatz EC14-320-350

[0440] Sae=MuAx313, glass filament scrim 300 g/m.sup.2, manufacturer designation: Saertex X-E-PA-313-655

[0441] Sae n.s.=glass filament scrim 300 g/m.sup.2, manufacturer designation: Saertex new sizing, +45/45/+45/45

[0442] Number of layers (for example 4=four layers of the respective fiber scrim or of the respective fibers)

[0443] The transparent fiber composite materials which follow were produced, into each of which was introduced flat fiber material. The fiber composite materials produced each had a thickness of about 1.1 mm. In order to further increase the comparability of the samples, a thin glass fiber nonwoven (GV50, see above) was applied to each side of the fiber composite materials produced. This has no noticeable effect on the mechanical or optical properties. For the samples, the following flexural strengths were ascertained according to DIN EN ISO 14125:

TABLE-US-00010 TABLE 10 Transparent fiber composite materials - flexural strength Glass Thick- Modulus content ness of Flexural No. Construction [g/m.sup.2] Matrix [mm] elasticity strength F/T_1 4xFG290 1260 M2 1.09 18.41 658.89 F/T_2 4xFG320 1380 M2 1.09 18.17 634.32 F/T_3 4xSae 1352 M2 1.16 18.44 444.33 F/T_4 Sae n.s. M2 1.17 15.93 621.04 F/T_5 4xFG320 1380 PC(OD) 1.14 23.36 377.97

[0444] Additionally produced were the black-colored fiber composite materials which follow, in which 2% by weight of industrial black was mixed into the matrix and into each of which flat fiber material was introduced. The fiber composite materials produced each had a thickness of about 1.1 mm. In order to further increase the comparability of the samples, a thin glass fiber nonwoven (GV50, see above) was applied to each side of the fiber composite materials produced. This has no noticeable effect on the mechanical or optical properties. For the samples, the following flexural strengths were ascertained according to DIN EN ISO 14125:

TABLE-US-00011 TABLE 11 Nontransparent fiber composite materials - flexural strength Glass Thick- Modulus content ness of Flexural No. Construction [g/m.sup.2] Matrix [mm] elasticity strength F/S_1 4xFG290 1260 M2 1.07 21.61 661.73 F/S_2 4xFG320 1380 M2 1.20 22.70 673.99 F/S_3 4xSae 1352 M2 1.15 14.92 385.21 F/S_4 4xSae 1352 PA6 1.13 14.30 477.77 F/S_5 4xFG320 1380 PA6 1.11 16.95 471.97

[0445] In summary, it is found that the weaves used (FG290 and FG320) can be processed to give fiber composite materials having particularly high flexural strength. The fiber composite materials of the invention in which the matrix comprises a component that reacts with the fibers (here: maleic anhydride (MA)) have a significantly higher flexural strength than comparative molding compounds without any such component, for instance PC(OD) or PA6.

[0446] By comparison, for the noninventive Luran 378P G7 fiber composite material reinforced with short glass fibers, only a flexural strength of 150 MPa was found, and so a much lower flexural strength. In addition, for the fiber composite materials, the impact resistance or penetration characteristics (dart test according to ISO 6603) were ascertained. Here too, the fiber composite materials showed a high stability of Fm>3000 N.

[0447] Optional Further Processing

[0448] It was also shown experimentally that the fiber composite materials obtained had good formability to give three-dimensional semifinished products, for example to give semifinished products in half-shell form. It was additionally shown that the fiber composite materials obtained were printable and laminatable.

SUMMARY OF THE EXPERIMENTAL RESULTS

[0449] The evaluation of different glass fiber-based textile systems with different matrix systems to give a fiber composite material (organosheet) showed that good fiber composite materials (as organosheets and semifinished products produced therefrom) can be produced in a reproducible manner. These can be produced in colorless or colored form. The fiber composite materials showed good to very good optical, tactile and mechanical properties (for instance with regard to their flexural strength and puncture resistance). In mechanical terms, the weaves showed somewhat greater strength and stiffness than scrims. The styrene copolymer-based matrices (SAN matrices) tended to lead to better fiber composite materials in terms of the mechanical indices than the alternative matrices such as PC and PA6. The fiber composite materials of the invention were producible in a semiautomatic or fully automatic manner by means of a continuous process. The fiber composite materials (organosheets) of the invention have good formability to give three-dimensional semifinished products.