POLYMER COMPOSITIONS THAT CONTAIN A SEMI-CRYSTALLINE POLYMER, AND PROCESS OF PREPARATION

Abstract

The invention relates to polymer compositions that contain a thermoplastic molding compound A, at least one reinforcing fiber B and at least one inorganic filler material C, the polymer composition having excellent aesthetic quality after thermoplastic processing. The invention also relates to a process for preparing the claimed composition and to uses thereof.

Claims

1-16. (canceled)

17. A polymeric composition comprising: a) 20 to 79% by weight of a thermoplastic molding composition A, wherein the thermoplastic molding composition A comprises at least one semicrystalline polymer A1; b) 10 to 79% by weight of at least one reinforcing fiber B; c) 1 to 70% by weight of at least one inorganic filler C; d) 0 to 10% by weight of at least one further additive D; wherein the at least one inorganic filler C has a coefficient of linear thermal expansion α.sub.C (CLTE, coefficient of linear thermal expansion, measured in accordance with ISO 11359-1 and ISO 11359-2) which is smaller than the coefficient of linear thermal expansion α.sub.A of the thermoplastic molding composition A, wherein the at least one inorganic filler C has a volume shrinkage which is 0.1 to 10 times as great as the volume shrinkage of the reinforcing fiber B, wherein the volume shrinkage is calculated from the coefficient of thermal volume expansion α.sub.V in 1/K of the respective component multiplied by the proportion of the respective component in the polymeric composition in % by volume/100, wherein: $\frac{{\alpha }_{V,C}\times \mathrm{proportion}\mathrm{by}\mathrm{volume}\mathrm{of}C}{{\alpha }_{V,B}\times \mathrm{proportion}\mathrm{by}\mathrm{volume}\mathrm{of}B}=0.1-10$ wherein α.sub.V,C=coefficient of thermal volume expansion of C in 1/K, wherein α.sub.V,C=3*α.sub.C; proportion by volume of C=proportion by volume of C, based on the entire polymeric composition, in % by volume/100; α.sub.V,B=coefficient of thermal volume expansion of B in 1/K, wherein α.sub.V,B=3*α.sub.B; proportion by volume of B=proportion by volume of B, based on the entire polymeric composition, in % by volume/100; and wherein the data in % by weight and in % by volume, respectively, are based on the entire polymeric composition.

18. The polymeric composition of claim 17, wherein the thermoplastic molding composition A comprises 1 to 100% by weight, based on the entire thermoplastic molding composition A, of the at least one semicrystalline polymer A1, selected from polyamide, polypropylene, and polyethylene.

19. The polymeric composition of claim 17, wherein the thermoplastic molding composition A comprises 60 to 99.9% by weight of the at least one semicrystalline polyolefin polymer A1 and 0.1 to 40% by weight of at least one polymer A2, respectively, based on the entire thermoplastic molding composition A.

20. The polymeric composition of claim 17, wherein the semicrystalline polyolefin polymer A1 is one or more semicrystalline homo- or copolymers of ethylene, propylene, butylene, and/or isobutylene.

21. The polymeric composition of claim 17, wherein the semicrystalline polyolefin polymer A1 is one or more polypropylene homopolymers.

22. The polymeric composition of claim 17, wherein the semicrystalline polyolefin polymer A1 is one or more semicrystalline polypropylene homopolymers, wherein the polypropylene homopolymer has less than 60% by weight of amorphous content, based on the polyolefin polymer A1.

23. The polymeric composition of claim 17, wherein the semicrystalline polyolefin polymer A1 is one or more semicrystalline polypropylene homopolymers, wherein the polypropylene homopolymers have a melt volume rate in the range of 50 to 70 ml/10 min.

24. The polymeric composition of claim 19, wherein the polymer A2 is at least one polymer of ethylene, propylene, butylene, and/or isobutylene, wherein the polymer comprises at least one functional monomer A2-1, selected from maleic anhydride, N-phenylmaleimide, tert-butyl(meth)acrylate, and glycidyl(meth)acrylate.

25. The polymeric composition of claim 19, wherein the polymer A2 is one or more propylene-maleic anhydride graft copolymers which have a proportion of maleic anhydride as monomer A2-1 in the range of 0.01 to 5% by weight, based on the polymer A2.

26. The polymeric composition of claim 17, wherein the at least one reinforcing fiber B is one or more glass fibers whose surface comprises functional groups, selected from hydroxy, ester, amino, and silanol groups.

27. The polymeric composition of claim 17, wherein the polymeric composition comprises 1 to 30% by weight of at least one inorganic filler C.

28. The polymeric composition of claim 17, wherein the polymeric composition comprises 1 to 30% by weight of at least one inorganic filler C in crystalline and/or amorphous form, selected from silicates, phosphates, sulfates, carbonates, and borates.

29. The polymeric composition of claim 17, comprising: a) 25 to 55% by weight of the at least one thermoplastic molding composition A; b) 40 to 60% by weight of the at least one reinforcing fiber B; c) 5 to 35% by weight of the at least one inorganic filler C; and d) 0 to 10% by weight of at least one further additive D.

30. A process for the production of a polymeric composition of claim 17, comprising the mixing of the components A, B, C, and optionally D.

31. The process of claim 30, wherein the mixing takes place at a temperature of at least 200° C.

32. A process for the production of a molding, comprising the polymeric composition of claim 17.

33. The process of claim 32, wherein the process comprises a forming process selected from compression molding, rolling, hot pressmolding, stamping, and/or a thermoplastic shaping process.

34. The process of claim 32, wherein the process further comprises a step of hardening of the molding.

35. The process of claim 32, wherein the molding undergoes a downstream operation.

36. The process of claim 35, wherein the downstream operation comprises the steps of deflashing, polishing, dyeing, or a combination thereof.

Description

EXAMPLE 1

[0145] The following experiments were carried out in a simple, heated batch press at temperatures of approximately 230-240° C., the pressure in the press being about 10 bar.

[0146] The average coefficients of linear thermal expansion a were measured as arithmetic average of the values in longitudinal and transverse direction in accordance with ISO 11359-1,2.

Components:

A1 Polypropylene

[0147] Polypropylene homopolymer, with a density <0.9 g/cm.sup.3; melt volume flow rate MVR (230° C./2.16 kg) 50-70 ml/10 min, mostly 60 ml/10 min; crystallization temperature (DSC) 130° C. Coefficients of thermal expansion Ω.sub.A1=60*10.sup.−6 K.sup.−1, coefficient of thermal volume expansion α.sub.V,A1=3*α.sub.A1=180*10.sup.−6 K.sup.−1

A2 PRIEX® 20093 (Altana, AddComp)

[0148] Chemically modified polypropylene polymer (white granulate) with a high content of grafted-on maleic anhydride (0.15-0.25% by weight) with a density of about 0.9 g/cm.sup.3. Coefficients of thermal expansion α.sub.A2c=65*10.sup.−6 K.sup.−1, coefficient of thermal volume expansion α.sub.V,A2=3*α.sub.A2=195*10.sup.−6 K.sup.−1

B Glass Fiber

[0149] Reinforcing fiber B used was a glass fiber twill with the following properties: size made of PP polymer, weight per unit area 600 g/m.sup.2, 1200 tex warp threads. Coefficients of thermal expansion α.sub.B=7*10.sup.−6 K.sup.−1, coefficient of thermal volume expansion α.sub.V,B=3*α.sub.B=21*10.sup.−6 K.sup.−1, density of B=about 2.5 g/ml.

C Inorganic Filler

[0150] The following fillers C were used:

[0151] C1 (of the Invention):

[0152] Glass powder with average particle size of approximately 50 μm

[0153] Coefficients of thermal expansion α.sub.C1=8*10.sup.−6 K.sup.−1, coefficient of thermal volume expansion α.sub.V,C1=3*α.sub.C1=24*10.sup.−6 K.sup.−1, density of C1=about 2.5 g/ml.

C2 (Comparison):

[0154] Polyamide-66 powder with average particle size of approximately 50 μm.

[0155] Coefficients of thermal expansion α.sub.C2=80*10.sup.−6 K.sup.−1, coefficient of thermal volume expansion α.sub.V,C2=3*α.sub.C,2=240*10 K.sup.−1, density of C2=1.3 g/ml.

[0156] The polymeric compositions described in table 1 with a thickness of 1.0 mm and 45% by volume content of glass fiber (component B as described above) were produced from the components described above by means of the process described above.

Mechanical Characterization:

[0157] Maximal flexural stress σ.sub.max was determined on the resultant compositions (moldings) by the three-point flexural test in accordance with DIN 14125. The values were measured respectively in the direction 0° (in fiber direction) and 90° (perpendicularly to the fiber direction). Table 1 presents the results. Optical appearance was assessed visually on the basis of the following system: [0158] 0: Completely flat, mirror-smooth surface [0159] 1: Slight undulations on a flat surface [0160] 2: Significant undulations, but gloss remains high [0161] 3: Large number of undulations, moderate gloss [0162] 4: Rough surface, low gloss

TABLE-US-00001 TABLE 1 Production and characterization of the polymeric compositions V3 V4 V1 V2 (inv.) (comp.) A1 % by wt. 50 55 35 35 A2 % by wt. 5 0 5 5 B % by wt. 45 45 30 30 Cl % by wt. 0 0 30 0 C2 % by wt. 0 0 0 30 [00008]$\frac{\text{?}\times \begin{array}{c}\mathrm{proportion}\mathrm{by}\mathrm{volume}\\ \mathrm{of}C\end{array}}{\text{?}\times \begin{array}{c}\mathrm{proportion}\mathrm{by}\mathrm{volume}\\ \mathrm{of}B\end{array}}$ — — 1.1 22 Flexural stress σ.sub.max 0° MPa 3121 240 Flexural stress σ.sub.max 90° MPa 325 274 Optical assessment of 3 4 2 3 surface [00009]$\text{?}\text{indicates text missing or illegible when filed}$

[0163] Example V3 is inventive; example V4 serves as comparative example.