CARBON FIBER-REINFORCED RESIN COMPOSITION AND SHAPED PRODUCT OBTAINED THEREFROM

Abstract

Disclosed are: a carbon fiber-reinforced resin composition excellent in properties such as strength and elastic modulus, comprising 100 parts by mass of a polymer alloy (A) which comprises: 25 to 95% by mass of one or more propylene-based polymers (p) selected from a propylene-ethylene block copolymer, a propylene homopolymer and a ropylene-ethylene random copolymer having an ethylene content of 5% by mass or less, 1 to 60% by mass of an acid-modified polyolefin resin (m), 0 to 40% by mass of an ethylene-based polymer (e) and 0 to 50% by mass of a polyamide (n) wherein the total of the component (p), the component (m), the component (e) and the component (n) is 100% by mass, and 1 to 200 parts by mass of a carbon fiber (B).

Claims

1. A carbon fiber-reinforced resin composition, comprising: 100 parts by mass of a polymer alloy (A) which comprises: 25 to 95% by mass of one or more propylene-based polymers (p) selected from a propylene-ethylene block copolymer, a propylene homopolymer and a propylene-ethylene random copolymer having an ethylene content of 5% by mass or less, 1 to 60% by mass of an acid-modified polyolefin resin (m), 0 to 40% by mass of an ethylene-based polymer (e) and 0 to 50% by mass of a polyamide (n) wherein the total of the component (p), the component (m), the component (e) and the component (n) is 100% by mass, and 1 to 200 parts by mass of a carbon fiber (B); the acid-modified polyolefin resin (m) comprises a maleic acid-modified propylene-based polymer (m1); the total of W.sub.p and W.sub.m1 is 50 to 98% by mass, in which the content of the component (p) is expressed by W.sub.p% by mass, the content of the component (m1) is expressed by Wm1% by mass (the content of the whole component (m) is expressed by Wm % by mass), the content of the component (e) is expressed by W.sub.e% by mass, and the content of the component (n) is expressed by W.sub.n% by mass in the polymer alloy (A), and the total of Wp, Wm, We and Wn is 100% by mass; and additionally; and, the following formula (1) is satisfied in which the melt flow rate (MFR) of the component (p) measured at 230° C. under a load of 2.16 kg according to ASTM D1238 is expressed by MFR.sub.p (g/10 min) and the melt flow rate (MFR) of the component (m1) measured at 230° C. under a load of 2.16 kg according to ASTM D1238 is expressed by MFR.sub.m1 (g/10 min).
Q.sub.p×log(MFR.sub.p)+Q.sub.m1×log(MFR.sub.m1)>log 120  (1) wherein, Q.sub.P W.sub.p (W.sub.p+W.sub.m1), Q.sub.m1=W.sub.m1/(W.sub.p W.sub.m1)

2. The carbon fiber-reinforced resin composition according to claim 1, wherein the composition comprises 100 parts by mass of the polymer alloy (A) and 1 to 80 parts by mass of the carbon fiber (B).

3. The carbon fiber-reinforced resin composition according to claim 1, wherein the melt flow rate (MFR) of the polymer alloy (A), measured at 230° C. under a load of 2.16 kg according to ASTM D1238, is 30 to 500 g/10 min.

4. The carbon fiber-reinforced resin composition according to claim 1, wherein the total of W.sub.p and W.sub.m is 50 to 100% by mass, W.sub.n is 0 to 50% by mass, and the ratio of Wp and Wm (Wp/Wm) is 70/30 to 98/2, in which the content of the component (p) is expressed by W.sub.p% by mass, the content of the component (m) is expressed by W.sub.m% by mass, the content of the component (e) is expressed by W.sub.e% by mass, and the content of the component (n) is expressed by W.sub.n% by mass in the polymer alloy (A), and the total of W.sub.p, W.sub.m, W.sub.e and W.sub.n is 100% by mass.

5. The carbon fiber-reinforced resin composition according to claim 1, wherein the acid-modified polyolefin resin (m) additionally comprises a maleic acid-modified ethylene-based polymer (m2).

6. The carbon fiber-reinforced resin composition according to claim 1, wherein the acid-modified polyolefin resin (m) comprises a maleic acid-modified propylene-based polymer (m1), and the melt flow rate (MFR) of the maleic acid-modified propylene-based polymer (m1), measured at 230° C. under a load of 2.16 kg according to ASTM D1238, exceeds 150 g/10 min.

7. (canceled)

8. The carbon fiber-reinforced resin composition according to claim 1, wherein the carbon fiber (B) is in the form of a carbon fiber bundle which has been sized using a sizing agent, and the sizing agent is an epoxy-based emulsion.

9. A shaped product, which is obtained by molding the carbon fiber-reinforced resin composition according to claim 1.

Description

EXAMPLES

[0083] Then, the present invention will be illustrated by way of examples, but the present invention is not restricted by them. First, raw materials used in Examples and Comparative Examples are shown below.

[Carbon Fiber (B)]

[0084] The following three kinds of short fibers manufactured by Toho Tenax Co., Ltd. “TENAX (registered trademark) Chopped Fiber” (CF-1˜CF-3) and the following filament “TANAX (registered trademark) Filament Yarn” (CF-4) were used. In addition, in Comparative Example 1-2, the following glass fibers (GF-1) manufactured by Central Glass Fiber Co., Ltd. were used. [0085] “CF-1”: HT C251; fiber length=6 mm, epoxy content=1.3% by mass [0086] “CF-2”: HT C227; fiber length=6 mm, epoxy content=7.0% by mass [0087] “CF-3”: HT C261; fiber length=3 mm, epoxy content=1.3% by mass [0088] “CF-4”: HTS40 12K; number of filaments=12000, epoxy content=1.3% by mass) [0089] GF-1: fiber length=3 mm
[Propylene-Based Polymer (p)]

[0090] The following propylene-ethylene block copolymer (b-PP) and the following four kinds of propylene homopolymers (h-PP (1)˜h-PP (4)) manufactured by Prime Polymer Co., Ltd. were used. [0091] “b-PP”: X855; MFR according to ASTM D1238 (the same shall apply hereinafter) (230° C., 2.16 kg)=15 g/10 min, 25° C. xylene-soluble part amount=23% by mass, limiting viscosity of 25° C. xylene-soluble part [η]=7.4 dl/g, ethylene content of 25° C. xylene-soluble part=39 mol % [0092] “h-PP (1)”: MFR (230° C., 2.16 kg)=15 g/10 min [0093] “h-PP (2)”: MFR (230° C., 2.16 kg)=50 g/10 min [0094] “h-PP (3)”: MFR (230° C., 2.16 kg)=63 g/10 min [0095] “h-PP (4)”: MFR (230° C., 2.16 kg)=220 g/10 min
[Ethylene-Based Copolymer (e)]

[0096] The following two kinds of ethylene-1-butene copolymers manufactured by Mitsui Chemicals, Inc. “TAFMER (registered trademark)” (e-1˜e-2) were used. [0097] “e-1”: DF940; ethylene content=90 mol %, MFR (230° C., 2.16 kg)=6.7 g/10 min [0098] “e-2”: DF7350; density=870 kg/m.sup.3, MFR (230° C., 2.16 kg)=65 g/10 min, melting point=55° C.

[0099] [Polyamide (n)]

[0100] The following three kinds of polyamide 12(s) manufactured by Ube Industries, Ltd. “UBESTA (registered trademark)” (PA-1˜PA-3) were used. [0101] “PA-1”: 3012U; melting point according to ISO11357-3 (the same shall apply hereinafter)=180° C., MFR according to ISO11357-3 (the same shall apply hereinafter) (190° C., 1.0 kg)=17 g/10 min) [0102] “PA-2”: 3014U; melting point=179° C., MFR (190° C., 1.0 kg)=9 g/10 min [0103] “PA-3”: 3020U; melting point=178° C., MFR (235° C., 2.16 kg)=20 g/10 min)
[Acid-Modified Polyolefin Resin (m)]

[0104] The following maleic-acid modified random polypropylene manufactured by Mitsui Chemicals, Inc. “ADMER (registered trademark) QE800” (m1-1), maleic anhydride-modified polypropylene (m1-2) prepared by the following method, and the following maleic acid-modified ethylene-based polymer manufactured by Mitsui Chemicals, Inc. “TAFMER (registered trademark) MH5020” (m2) were used. [0105] “m1-1”: MFR according to ASTM D1238 (the same shall apply hereinafter) (230° C., 2.16 kg)=9.0 g/10 min [0106] “m1-2”: Into 100 parts by mass of polypropylene (manufactured by Prime Polymer Co., Ltd., tradename J106G, MFR (230° C., 2.16 kg)=15 g/10 min) were pre-mixed with 1 mass part of dialkyl peroxide (manufactured by NOF CORPORATION, Perhexa (registered trademark) 25B) and 3 parts by mass of powdered maleic anhydride (manufactured by NOF CORPORATION, CRYSTAL MAN (registered trademark)). This mixture was supplied to a 30 mm φ biaxial extruder, a temperature of which had been regulated at 190° C., and melted and kneaded at 200 rpm to obtain a strand, which was then cooled in a water tank to obtain maleic anhydride-modified polypropylene. In order to remove unmodified remaining maleic anhydride, this maleic anhydride-modified polypropylene was vacuum-dried at 40° C. for 2 hours. The content of maleic acid of the resulting maleic anhydride-modified polypropylene (m1-2) was 2.5% by mass, and the MFR (230° C., 2.16 Kg) was 800 g/10 min. [0107] “m2”: MFR (230° C., 2.16 Kg)=1.2 g/10 min

Example 1-1

<Assessing Method 1 (DSM Method)>

[0108] A component (n), a component (m1), a component (m2), a component (p), a component (e) and a component (B) in amounts shown in Table 1 were placed in this order into a kneading potion having a volume of 100 cc of a kneading device (manufactured by Toyo Seiki Seisaku-Sho, Ltd., Labo Plastomill (registered trademark) 75C100), the roller rotation number of which was set at 5 rpm and the temperature of which was set at 180° C., and after completion of placement, the set temperature was raised up to 190° C. Then, an operation of increasing the roller rotation number to 10.fwdarw.30.fwdarw.50.fwdarw.70.fwdarw.90 rpm at an interval of 10 seconds was repeated three times. Thereafter, kneading was performed at 30 rpm for 10 minutes, then, the kneaded product was taken out from the mill, and the massy kneaded product was pressed with a simple pressing machine to obtain a sheet-like carbon fiber-reinforced resin composition having a thickness of around 2 mm.

[0109] The above-described sheet-like carbon fiber-reinforced resin composition was cut into small pieces with a cutter, and placed into a hopper portion of a small kneading machine (DSM Xplore MC15M) of a resin kneading and molding assessing apparatus (manufactured by Xplore Instruments) and kneaded at 180° C. for 3 minutes. Thereafter, the kneaded product was immediately placed into a pot portion (220° C.) of an injection molding machine for manufacturing a test piece (DSM Xplore IM12M), and injection-molded into a mold at 30 to 40° C. under a pressure of 9 MPa (primary) and 12 MPa (secondary), and this was retained for 35 seconds to manufacture a dumb-bell-type test piece according to JIS K 7162 1994. Then, a tensile test was performed under the conditions of a tensile speed of 50 mm/min and a distance between chucks of 50 mm. The results of the tensile yield stress (YS) (MPa), the tensile elongation at breakage (%) and the tensile elastic modulus (apparent tensile elastic modulus) (GPa) in a stress-strain curve are shown in Table 1.

<Assessing Method 2 (Plate Excising Method)>

[0110] A component (n), a component (m1), a component (m2), a component (p), a component (e) and a component (B) in amounts shown in Table 1 were placed in this order into a hopper of a screw-type extruder, a temperature of which had been regulated at 250° C. In addition, the component (B) was extended and opened at such a speed that the amount of the component (B) became 100 parts by mass, supplied to a die head of the extruder, stranded, cooled to solidify, and pelletized with a strand cutter to obtain a pellet-like carbon fiber-reinforced resin composition.

[0111] The above-described pellet-like carbon fiber-reinforced resin composition was placed into an injection molding machine at a cylinder temperature of 250° C. and a clamping pressure of 100 t, and a mold of 120 mm×120 mm×3 mm was used to obtain a plate-like shaped product. This plate-like shaped product was used according to JIS K 7162IBA (ISO527-2) to make an excised test piece. Regarding the excised test piece, a bending test was performed according to ISO178, and the bending elastic modulus (GPa) and the bending strength (MPa) in a stress-strain curve were obtained. In addition, regarding the excised test piece, a Charpy impact test was performed according to JIS K7111 (test piece size=10 mm×80 mm×4 mm, notch=machining), and the Charpy impact strength (kJ/m.sup.2) at 23° C. was obtained. The results are shown in Table 1.

<Actually Measured MFR>

[0112] The melt flow rate (MFR) of the component (A) was measured at 230° C. under a load of 2.16 kg according to ASTM D1238. The results are shown in Table 1.

Example 1-2

[0113] According to the same manner as that of Example 1-1 except that CF-1 as the component (B) was changed to CF-2, assessment was performed. The results are shown in Table 1.

Example 1-3

[0114] According to the same manner as that of Example 1-1 except that CF-1 as the component (B) was changed to CF-3, assessment was performed. The results are shown in Table 1.

Comparative Example 1-1

[0115] According to the same manner as that of Example 1-1 except that the component (B) was not used, assessment was performed. The results are shown in Table 1.

Comparative Example 1-2

[0116] According to the same manner as that of Example 1-1 except that CF-1 as the component (B) was changed to GF-1, assessment was performed. The results are shown in Table 1. In the present Comparative Example, tensile yield stress and tensile elastic modulus exhibited somewhat great values as compared with Comparative Example 1-1 using no fibers, but mechanical properties were inferior as compared with Examples 1-1 to 1-3 using the carbon fibers.

TABLE-US-00001 TABLE 1 Comp. Comp. Ex. Ex. Ex. Ex. Ex. 1-1 1-2 1-3 1-1 1-2 Component (B) CF-1 [parts by mass] 6 parts by mass with respect CF-2 [parts by mass] 6 to 100 parts by mass of CF-3 [parts by mass] 6 component (A) CF-4 [parts by mass] G F [parts by mass] 6 Component Component b-PP [% by mass] 35 35 35 35 35 (A) (p) h-PP (1) [% by mass] h-PP (2) [% by mass] h-PP (3) [% by mass] h-PP (4) [% by mass] Component e-1 [% by mass] 12 12 12 12 12 (e) e-2 [% by mass] Component m1-1 [% by mass] 18 18 18 18 18 (m) m1-2 [% by mass] m2 [% by mass] 12 12 12 12 12 Component PA-1 [% by mass] (n) PA-2 [% by mass] PA-3 [% by mass] 23 23 23 23 23 (Total) [% by mass] 100 100 100 100 100 W.sub.p + W.sub.m [% bymass] 65 W.sub.p/W.sub.m [−] 55/45 Actually measured MFR of compo-nent (A) [g/10 min] 1.2 (230° C., load 2.16 kg) MFR calculated from formula (1) left side [g/10 min] 13 (230° C., load 2.16 kg) Assessing method 1 Tensile yield stress [MPa] 34 33 34 24 28 (DSM method) Tensile elongation [%] 20 18 18 220 120 at breakage Tensile elastic [GPa] 1.8 1.8 1.9 0.8 1.1 modulus Assessing method 2 Bending elastic [GP] 1.9 1.8 1.9 — — (Plate excising method) modulus Bending [MPa] — — — — — strength Charpy impact [kJ/m.sup.2] 11 10 11 — — strength

Example 2-1

[0117] According to the same manner as that of Example 1-1 except that the component (p), the component (m) and the component (B) in amounts shown in Table 2 were placed into Labo Plastomill (registered trademark) in this order, the same test piece as that of the assessing method 1 in Example 1-1 was made, a tensile test was performed, and the tensile elastic modulus (GPa) and the tensile strength (MPa) in a stress-strain curve were obtained. In addition, the MFR (230° C., 2.16 kg) of the component (A) was also measured. The results are shown in Table 2.

Comparative Example 2-1

[0118] According to the same manner as that of Example 2-1 except that the component (m) was not used and the amounts of respective components were changed as shown in Table 2, molding of a test piece was tried. However, since the carbon fiber was not uniformly melted and kneaded, molding could not be performed.

Example 2-2

[0119] According to the same manner as that of Example 2-1 except that h-PP (4) was used as the component (p), the component (n) was used concurrently, and the amounts of respective components were changed as shown in Table 2, a test piece was made, and assessed. The results are shown in Table 2. In the present Example, despite the fact that the content of the carbon fibers (component (B)) was lower than that of Example 2-1, higher tensile properties were exhibited. Further, the MFR of the polymer alloy (A) of the present example exhibited a high value of 250 g/10 min, and from this, it was seen that the test piece is easily melted and kneaded (the carbon fibers were sufficiently impregnated at the low feed energy amount).

Example 2-3

[0120] According to the same manner as that of Example 2-2 except that h-PP (3) was used as the component (p), a test piece was made and assessed. The results are shown in Table 2. In the present Example, since the MFR of the component (p) was slightly lower as compared with Example 2-2, it was seen that tensile properties also tend to be reduced. However, this is practically the level having no problem.

Reference Example 2-1

[0121] According to the same manner as that of Example 2-2 except that h-PP (1) was used as the component (p), a test piece was made and assessed. The results are shown in Table 2. In the present Reference Example, since the MFR of the component (p) was considerably lower as compared with Example 2-2, the MFR of the polymer alloy (A) was also considerably reduced, and tensile properties were reduced to a degree that an improvement is practically desirable.

Example 2-4

[0122] According to the same manner as that of Example 2-1 except that h-PP (4) as the component (p), the component (m), the component (n) and the component (B) were used in amounts shown in Table 2, the same test piece as that of the assessing method 1 was made and assessed. In addition, the same test piece as that of the assessing method 2 of Example 1-1 was also made, and the bending elastic modulus (GPa), the bending strength (MPa) and the Charpy impact strength (kJ/m.sup.2) were measured. Further, regarding the test piece of the assessing method 2, a tensile test was performed at a tensile speed of 5 mm/min, and the tensile elastic modulus (GPa) and the tensile strength (MPa) in a stress-strain curve were also measured. The results are shown in Table 2.

Example 2-5

[0123] According to the same manner as that of Example 2-4 except that h-PP (3) was used as the component (p), and the amounts of respective components were changed as shown in Table 2, a test piece was made and assessed. The results are shown in Table 2. Since the MFR of the component (p) was slightly lower in the present Example as compared with Example 2-4, it was seen that tensile properties and bending properties tend to be reduced. However, this is practically the level having no problem.

Reference Example 2-2

[0124] According to the same manner as that of Example 2-4 except that h-PP (1) was used as the component (p), a test piece of the assessing method 2 was made and assessed (provided that Charpy impact strength is excluded). The results are shown in Table 2. In the present Reference Example, since the MFR of the component (p) was considerably lower as compared with Example 2-4, the MFR of the polymer alloy (A) was also considerably reduced, and tensile properties were reduced to a degree that an improvement is practically desirable.

Example 3-1

[0125] According to the same manner as that of Example 2-4 except that b-PP as the component (p), the component (e), the component (m), the component (n) and the component (B) were used in amounts shown in Table 2, a test piece of the assessing method 2 was made and assessed. The results are shown in Table 2. In the present Example, tensile properties and bending properties were lower than those of Examples 2-4 and 2-5 using h-PP, but the Charpy impact strength was greatly improved.

Example 3-2

[0126] According to the same manner as that of Example 3-1 except that the amount of the component (B) was increased as shown in Table 2, a test piece of the assessing method 2 was made and assessed. The results are shown in Table 2. In the present Example, since the amount of the carbon fiber (component (B)) was larger than that of Example 3-1, not only were tensile properties and bending properties improved, but also the impact resistance (Charpy impact strength) was improved by 30 to 40%.

TABLE-US-00002 TABLE 2 Comp. Ref. Ref. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. 2-1 2-1 2-2 2-3 2-1 2-4 2-5 2-2 3-1 3-2 Component (B) CF-1 [parts by mass] parts by mass with CF-2 [parts by mass] respect to 100 parts by CF-3 [parts by mass] 67 67 10 10 10 mass of component CF-4 [parts by mass] 67 67 67 26 64 (A) G F [parts by mass] Component Component b-PP [% by mass] (A) (p) h-PP (1) [% by mass] 76 66 h-PP (2) [% by mass] 90 100 h-PP (3) [% by mass] 76 76 24 24 h-PP (4) [% by mass] 76 66 Component e-1 [% by mass] (e) e-2 [% by mass] 12 12 Component m1-1 [% by mass] (m) m1-2 [% by mass] 10 14 14 14 12 14 12 3 3 m2 [% by mass] 12 12 Component PA-1 [% by mass] 10 10 10 22 10 22 (n) PA-2 [% by mass] 14 14 PA-3 [% by mass] (Total) [% by mass] 100 100 100 100 100 100 100 100 100 100 W.sub.p + W.sub.m [% bymass] 100 100 90 90 90 78 90 78 74 W.sub.p/W.sub.m [−] Actually measured MFR of [g/10 min] 50 48 250 60 20 160 60 20 7 component (A) (230° C., load 2.16 kg) MFR calculated from formula (1) [g/10 min] 66 50 267 92 28 267 92 27 32 left side (230° C., load 2.16 kg) Assessing method 1 Tensile [GPa] 10.7 Unmold- 4.5 4.2 3.0 10.5 7.0 — — — (DSM method) elastic able odulus Tensile [MPa] 130 78 71 48 126 115 — — — strength Assessing method 2 Tensile [GPa] — — — — — 7.9 7.2 5.5 3.7 5.2 (Plate excising method) strength modulus Tensile [MPa] — — — — — 134 138 90 68 74 strength Bending [GPa] — — — — — 17.4 17.1 12.5 6.0 10.0 elastic modulus Bending [MPa] — — — — — 213 218 160 99 112 strength Charpy [kJ/m.sup.2] — — — — — 8 10 — 17 23 impact strength