Polymer composition, fibre-composite semi-finished product and method for the production thereof

Abstract

The invention relates to a polymer composition and a fiber-composite semi-finished product, the surface thereof being at least partially formed from the polymer composition. The invention also relates to an associated production method for the fiber-composite semi-finished product. Said polymer composition is characterized in that it contains 100 parts by weight of a polyamide and 0.5-20 parts by weight of one or more adhesion-promoting additives.

Claims

1. A polymer composition, containing a) 100 parts by weight of a polyamide; b) 0.5 to 20 parts by weight of one or more adhesion-promoting additives of Formula (I):
M.sub.aM.sub.bD.sub.cD.sub.d(I) with M=[R.sub.3SiO.sub.1/2] M=[RR.sub.2SiO.sub.1/2] D=[R.sub.2SiO.sub.2/2] D=[RRSiO.sub.2/2] wherein each R independently stands for methyl or phenyl, wherein R is a glycidyloxypropyl radical of Formula (II) ##STR00003## wherein the following holds true for the indices: a=0 to 2, b=0 to 2, c=15 to 100, d=0 to 50, a+b=2, and b+d2, wherein a ratio (a+c)/(b+d) of the sum of the indices a +c to the sum of the indices b +d ranges from 4 to 20, wherein the composition includes at least 90% by weight of the mixture of polyamide with the adhesion-promoting additive of Formula (I), and wherein the adhesion-promoting additive of Formula (I) does not react with the polyamide.

2. The polymer composition of claim 1, wherein R stands for methyl.

3. The polymer composition of claim 1, wherein a ratio (a+c)/(b+d) of the sum of the indices a+c to the sum of the indices b+d ranges from 2 to 50.

4. The polymer composition of claim 1, wherein it holds true for index c that: c=15 to 100.

5. The polymer composition of claim 1, wherein (i) in the case that b=2, it holds true for index d that: d=0 to 20; and (ii) in the case that b=0, it holds true for index d that: d=2 to 20.

6. The polymer composition of claim 1, wherein the polymer composition contains 0.5 to 5 parts by weight of the adhesion-promoting additive.

7. The polymer composition of claim 1, wherein the polyamide is selected from the group comprising polyamide 6, polyamide 12 and polyamide 6,6.

8. The polymer composition of claim 7, wherein the polyamide is polyamide 6.

9. A semi-finished fiber composite product based on polyamide, wherein at least a part of the surface of the semi-finished product is formed from a polymer composition according to claim 1.

10. A film containing a polymer composition of claim 1, wherein the film is between 10 m and 600 m in thickness.

11. The film of claim 10, wherein both sides of the film have at its boundary layer a zone in which the adhesion-promoting additive of Formula (I) is accumulated.

12. A method of producing a semi-finished fiber composite product, the method comprising the steps of: a) providing a polymer composition of claim 1; b) producing a film of the polymer composition; and c) processing the film as part of the manufacturing process of the semi-finished fiber composite product by way of the film-stacking process or the direct melt process or by laminating.

13. A semi-finished fiber composite product obtainable by the method of claim 12.

14. The polymer composition of claim 3, wherein the ratio ranges from 4 to 20.

15. The polymer composition of claim 3, wherein the ratio ranges from 5 to 15.

16. The polymer composition of claim 4, wherein it holds true for index c that: c=20 to 50.

17. The polymer composition of claim 5, wherein in the case that b=2, it holds true for index d that: d=1 to 10.

18. The polymer composition of claim 5, wherein in the case that b=0, it holds true for index d that: d=3 to 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the invention will be explained in detail using some embodiments and the accompanying drawings. The figures show:

(2) FIG. 1 a schematic view of the design of a semi-finished fiber composite product manufactured by way of the film-stacking process;

(3) FIG. 2 a schematic view of the design of a semi-finished fiber composite product manufactured by way of the direct melt process;

(4) FIG. 3 a schematic view of the distribution of the adhesion-promoting additive over the cross-section of a film in accordance with the present invention; and

(5) FIG. 4 an XMS measurement of a film for determining the silicon concentration as a function of the distance to the surface. Each line corresponds to a depth increasing by 0.2 nm; the highest concentration was found in the surface.

DETAILED DESCRIPTION OF THE INVENTION

(6) The polymer compositions in accordance with the present invention, the films in accordance with the present invention which contain the polymer compositions in accordance with the present invention, the semi-finished fiber composite products in accordance with the present invention which contain the polymer compositions in accordance with the present invention and the method in accordance with the present invention of producing the semi-finished fiber composite product will be described below by way of examples. Where ranges, general formulae or classes of compounds are indicated below, they shall encompass not just the respective ranges or groups of compounds that are explicitly mentioned but also all sub-ranges and sub-groups of compounds which are obtainable by extraction of individual values (ranges) or compounds. Where documents are cited in the context of the present description, their content shall fully form part of the disclosure content of the present invention. Where % figures are given below, these are figures in % by weight, unless otherwise specified. In the case of compositions, the % figures refer to the overall composition, unless otherwise specified. Where average values are indicated below, these are mass averages (weight averages), unless otherwise specified. Where measurement values are indicated below, these measurement values were determined under a pressure of 101325 Pa and at a temperature of 25 C., unless otherwise specified.

(7) General Instructions for Producing the Polymer Composition

(8) In an extruder, adhesion-promoting additives of Formula (I)
M.sub.aM.sub.bD.sub.cD.sub.d(I) with M=[R.sub.3SiO.sub.1/2] M=[RR.sub.2SiO.sub.1/2] D=[R.sub.2SiO.sub.2/2] D=[RRSiO.sub.2/2]
wherein each R stands for methyl and R is a glycidyloxypropyl radical of Formula (II)

(9) ##STR00002##
have been either added directly to polyamides (polyamide 6 or polyamide 6,6) by liquid dosing or supplied as masterbatch in solid form.

(10) In the case of liquid dosing (as provided for example by the Dutch company Movacolor), the additives have been mixed in homogeneously in the first third of the extrusion line (0.1 to 20% by weight in relation to the total weight of the polymer composition). For high viscosity additives, a pump with a heatable inlet pipe and a heatable feed vessel was used as an alternative.

(11) Alternatively, 50% masterbatches of the additives in polyamide were produced. Using a separate feeder, the masterbatches were dosed into the main feed throat of the extrusion line, where also the respective polyamide was fed in.

(12) TABLE-US-00001 TABLE 1 Additives of Formula (I) that were used a b c d OMS 1 0 2 18 0 OMS 2 2 0 89 7 OMS 3 2 0 43 5 OMS 4 2 0 73 25 OMS 5 0 2 16 2

(13) The temperature profile in the extruder corresponded to the recommendations by the manufacturer of the respective polyamide. Optionally, the polyamides were pre-dried if their moisture content was above 0.1% by weight. The polymer compositions were processed at a machine output of 3 to 10 kg per hour in dependence on the filling level and the polymer.

(14) Testing the Polymer Compositions in Accordance with the Present Invention

(15) The quality of the distribution of the additives used in the polyamides was assessed directly using the appearance of the strand on its discharge from the extruder head. A homogeneous distribution of the additive in the polyamide was assumed if a homogeneous strand was formed without bubbles, without strand rupture and without a strand thickness variation by more than 20%. This state was designated as OK in the embodiments mentioned below.

(16) TABLE-US-00002 TABLE 2 Polymer composition based on polyamide 6 (PA6) and polyamide 6,6 (PA6,6) Composition 0.1% 0.5% 1% 2% 4% 10% 20% PA6/OMS 1 OK OK OK OK OK OK OK PA6/OMS 2 OK OK OK OK OK OK OK PA6/OMS 3 OK OK OK OK PA6/OMS 4 OK OK OK OK PA6/OMS 5 OK OK OK OK Composition 2% 4% 6% 8% 10% PA6/OMS MB 1 OK OK OK OK OK PA6/OMS MB 2 OK OK OK OK OK PA6/OMS MB 3 OK OK PA6/OMS MB 4 OK OK PA6/OMS MB 5 OK OK Composition 0.5% 1% 2% 4% 10% PA6,6/OMS 1 OK OK OK OK OK PA6,6/OMS 2 OK OK OK OK OK

(17) MB means dosing as masterbatch, no additional specification means dosing via liquid dosing; not specified means that these compositions were not produced. All polymer compositions that were made fulfilled all quality criteria specified above.

(18) Film Production

(19) The films were produced in a casting process as so-called cast films with a layer thickness of 50 to 600 m (cast film line built by the Collin company). The quality of the films was assessed by measuring and comparing the layer thickness in different regions of the film, with a layer thickness variation of less than 15% being designated as OK in the application examples shown below.

(20) The thickness was determined by using a digital outside micrometer of the Mitutoyo company with a clamping force of 7 to 9 Newton to determine the thickness of the film at 5 arbitrarily and randomly selected points of a sample measuring 30 cm by 30 cm from the center of the material.

(21) It is not required for the resulting film made of the polymer composition to be transparent; rather, it can also have an opaque appearance.

(22) TABLE-US-00003 TABLE 3 Films - polymer composition and layer thickness Film layer thickness in m Polymer composition 50 100 150 250 400 600 PA6/0.5% OMS 1 OK OK OK OK OK PA6/2% OMS 1 OK OK OK OK OK OK PA6/4% OMS 1 OK OK OK OK OK PA6/10% OMS 1 OK OK OK OK PA6/0.5% OMS 2 OK OK OK OK OK OK PA6/2% OMS 2 OK OK OK OK OK OK PA6/4% OMS 2 OK OK OK OK OK PA6/10% OMS 2 OK OK OK OK OK PA6/2% OMS MB 2 OK OK OK OK OK OK PA6/4% OMS MB 2 OK OK OK OK

(23) If no values are given, the respective films were not produced. It is apparent that all films that were made fulfilled the quality criteria specified above.

(24) Producing a Semi-Finished Fiber Composite Product Based on a Film

(25) The films that were made were further processed into semi-finished fiber composite products by way of the film-stacking process or the direct melt process. FIG. 1 provides a schematic illustration of the structure of the semi-finished fiber composite product when using the film-stacking process and FIG. 2 when using the direct melt process.

(26) The design of the installation technology for performing both of these processes is sufficiently well known and comprises units for material feeding, an interval pressing unit with impregnation and compositing lines and, arranged downstream, a roll mill and a fabricating unit. The material feed includes roll holders for the individual polyamide films and semi-finished textile products, such as woven or non-woven fabrics, utilized in the respective processes. In the case of the direct melt process, a separate plastication unit for direct impregnation with polymer melts is present. The impregnation and compositing line in which the fed films, semi-finished textile products and, if applicable, melts are combined is predetermined by the interval pressing unit. Such installations are sufficiently well known, see for example the publications of the Neue Materialien Frth GmbH company.

(27) FIG. 1 shows an exemplary sequence of alternating layers of various materials such as can be used in producing a semi-finished fiber composite product by way of the film-stacking process. According to this embodiment, the matrix material is provided by feeding a total of five matrix films 40 into the interval pressing unit. Each matrix film 40 consists of polyamide, in particular polyamide 6. Four layers of a semi-finished reinforcement product 42 are arranged alternatingly between the matrix films 40. The semi-finished reinforcement product 42 includes the fibers serving as reinforcement. Possible fiber types for this purpose are, for example, glass fibers, carbon fibers or aramid fibers. Possible types of semi-finished reinforcement products comprise woven and non-woven fabrics. Finally, a modified peripheral film 44 made of the polymer composition in accordance with the present invention is provided in each of the peripheral regions of the layer stack shown.

(28) When using the direct melt process, layers of a semi-finished reinforcement product 42 and a modified peripheral film 44 are fed into the interval pressing unit, as well, in the sequence illustrated in FIG. 2. In addition, a polymer melt 46 consisting of polyamide, in particular polyamide 6, is fed in by way of a plastication unit.

(29) The structure illustrated in FIGS. 1 and 2, in particular the sequence of layers and the number of layers of the semi-finished reinforcement product 42 and the matrix film 40, is variable and can be adapted to the respective requirements. Of importance for the purpose of the invention is only that a modification of the peripheral layers on one side or both sides of the semi-finished fiber composite product is performed by laminating with the modified peripheral film 44 made of the polymer composition in accordance with the present invention.

(30) Manufacturing Process of a Semi-Finished Fiber Composite Product without Film Production

(31) A further method of producing a semi-finished fiber composite product with modified peripheral layers without prior film production is provided by the double-belt pressing process. In this process, one or more layers of a dry (not impregnated) endless fiber-reinforced semi-finished fiber composite product are drawn into a double-belt press. Just as in the direct melt process, the matrix material is applied to the dry fabric, preferably through a flat-sheet die, in the triangular space between the individual layers.