RESIN COMPOSITION AND MOLDED ARTICLE THEREOF

Abstract

Disclosed is a resin composition including a thermoplastic resin (A) and a polyrotaxane (B) whose cyclic molecule is modified with a graft chain having a reactive functional group at the end, which are mixed together, the resin composition containing a fibrous filler (C) in the amount of 1 to 200 parts by weight relative to 100 parts by weight of the total amount of the thermoplastic resin (A) and the polyrotaxane (B). To provide a resin composition capable of affording a molded article having excellent balance between rigidity and toughness.

Claims

1. A resin composition comprising a thermoplastic resin (A), a polyrotaxane (B) whose cyclic molecule is modified with a graft chain having a reactive functional group at the end, and a fibrous filler (C), which are mixed together, wherein the thermoplastic resin (A) is a resin selected from a polyamide resin, a styrene-based resin, a polycarbonate resin, a polyester resin and a polyarylene sulfide resin, the reactive functional group at the end of the graft chain of the polyrotaxane (B) is at least one group selected from a hydroxyl group, an amino group, a carboxyl group, an acid anhydride group, a glycidyl group, an isocyanate group, an isothiocyanate group, a thiol group, an oxazoline group and a sulfonic acid group, and the resin composition containing the fibrous filler (C) in the amount of 1 to 200 parts by weight relative to 100 parts by weight of the total amount of the thermoplastic resin (A) and the polyrotaxane (B).

2. The resin composition according to claim 1, wherein, when a test piece in conformity with ISO527-1:2012 is formed using the resin composition and tensile properties of the test piece are measured by the method in conformity with ISO527-1:2012, a number average length of the exposed portion of the fibrous filler in a fracture surface of the test piece is 0.1 mm or more after the measurement.

3. The resin composition according to claim 1, wherein, when a test piece in conformity with ISO178:2010 is formed using the resin composition and bending properties of the test piece are measured by the method in conformity with ISO178:2010, an elastic modulus is 3 GPa or more and the test piece causes no fracture even after exceeding the yield point.

4. The resin composition according to claim 1, wherein the fibrous filler (C) is at least one selected from the group consisting of a glass fiber and a carbon fiber.

5. A molded article comprising the resin composition according to claim 1.

Description

EXAMPLES

[0073] The present invention will be described by way of Examples, but the present invention is not limited to these Examples. To obtain a resin composition of each Example, the following raw materials were used.

<Thermoplastic Resin>

[0074] (A-1): Nylon 6 resin (AMILAN (registered trademark), manufactured by Toray Industries, Ltd.) .sub.r=2.70, melting point of 225 C., amide group concentration of 10.5 mmol/g.

[0075] Here, the above relative viscosity .sub.r was measured at 25 C. in a 98% concentrated sulfuric acid solution having the concentration of 0.01 g/ml. The melting point was determined by the following procedure using a differential scanning calorimeter. In an inert gas atmosphere, the temperature of a polyamide was decreased to 30 C. from a molten state at a tempeature decrease rate of 20 C./minute and the temperature was increased to 265 C. at a temperature rise rate of 20 C./minute, and then the temperature of an endothermic peak observed was regarded as the melting point. When two or more endothermic peaks were observed, the temperature of the endothermic peak having the largest peak intensity was regarded as the melting point. The amide group concentration was calculated from a structural formula of a structural unit using the following equation (1).

[0076] Amide group concentration (mol/g)=(number of amide groups of structural unit/molecular weight of structural unit) (1).

[0077] (A-2): Polybutylene terephthalate resin (TORAYCON (registered trademark), manufactured by Toray Industries, Ltd.), =0.85 dl/g (measured at 25 C. in an o-chlorophenol solution), melting point of 223 C.

[0078] An intrinsic viscosity was measured at 25 C. in an o-chlorophenol solution having the concentration adjusted to 0.5% by weight. The melting point was defined as a temperature of an endothermic peak which appears when the temperature of polybutylene terephthalate is decreased to 30 C. from a molten state in an inert gas atmosphere at a temperature decrease rate of 20 C./minute, and then increased to 263 C. at a temperature increase rate of 20 C./minute, using a differential scanning calorimeter. When two or more endothermic peaks are detected, a temperature of an endothermic peak having the largest peak intensity was defined as the melting point.

[0079] (A-3): Nylon 66 resin (AMILAN (registered trademark), manufactured by Toray Industries, Ltd.), .sub.r=2.78, melting point of 260 C., amide group concentration of 8.84 mmol/g.

[0080] (A-4) : Nylon 610 resin (AMILAN (registered trademark), manufactured by Toray Industries, Ltd.) , .sub.r=2.71, melting point of 223 C., amide group concentration of 7.08 mmol/g.

<Polyrotaxane>

[0081] (B-1): Polyrotaxane (SeRM (registered trademark) Super Polymer SH2400P, manufactured by Advanced Softmaterials Inc.) was used. The end group of a graft chain modifying a cyclic molecule of this polyrotaxane is a hydroxyl group, a hydroxyl value in conformity with JIS K0070 is 1.3510.sup.3 mol/g, a number average molecular weight of polyethyleneglycol as a linear molecule is 20,000, and an entire weight average molecular weight is 400,000.

[0082] The weight average molecular weight of the polyrotaxane means a value in terms of poly (methyl methacrylate), measured by gel permeation chromatography in which hexafluoroisopropanol is used as a solvent and Shodex HFIP-806M (two columns)+HFIP-LG are used as columns.

<Fibrous Filler>

[0083] (C-1): Glass fiber (T-249, manufactured by Nippon Electric Glass Co., Ltd.) was used.

[0084] (C-2): Glass fiber (T-253, manufactured by Nippon Electric Glass Co., Ltd.) was used.

<Other Components>

[0085] (D-1): Maleic anhydride-modified ethylene-butene copolymer TAFMER (registered trademark) MH5040, manufactured by MitsUi Chemicals, Inc.) was used. The functional group concentration is 3.210.sup.4 mol/g.

<Evaluation Methods>

[0086] A description will be made on evaluation methods in the respective Examples and Comparative Examples. Unless otherwise specified, the number of samples to be evaluated (n) was 5 and an average was determined.

(1) Rigidity (Bending Elastic Modulus)

[0087] Pellets obtained by the respective Examples and Comparative Examples were vacuum-dried at 80 C. for 12 hours and then injection-molded under the conditions shown in Tables 1 and 2 using an injection molding machine (SE75DUZ-C250, manufactured by Sumitomo Heavy Industries, Ltd.) to fabricate multi-purpose test, pieces in conformity with ISO178:2010. With respect to bending test pieces obtained from these multi-purpose test pieces, a bending test was performed at a crosshead speed of 2 mm/min in accordance with ISO178:2010 using a precision universal testing machine AG-20 kNX (manufactured by Shimadzu Corporation) and then a bending elastic modulus was determined.

(2) Bending Fracture Behavior

[0088] In the above-mentioned bending test, the case where the test piece causes no fracture even after exceeding the yield point was rated no fracture, while the case where the test piece is fractured before exceeding the yield point was rated fracture.

(3) Toughness (Tensile Elongation at Break)

[0089] Pellets obtained by the respective Examples and Comparative Examples were vacuum-dried at 80 C. for 12 hours and then injection-molded under the conditions shown in Tables 1 and 2 using an injection molding machine (SE75DUZ-C250, manufactured by Sumitomo Heavy Industries, Ltd.) to fabricate 1A-type multi-purpose test pieces in conformity with ISO527-1:2012. With respect to tensile test pieces obtained from these multi-purpose test pieces, a tensile test was performed at a tensile speed of 5 mm/min and a gauge length of 75 mm in accordance with ISO527-1:2012 using a precision universal testing machine AG-20 kNX (manufactured by Shimadzu Corporation) and then a tensile elongation at break was determined.

(4) Number Average Length of Exposed Portion of Fibrous Filler (Exposed Fiber Length)

[0090] The fracture surface of the test piece after fracture in the above-mentioned tensile test was observed using an optical microscope (50 to 1,000 times). Each. length of 1,000 fibrous fillers selected at random from fibrous fillers exposed from the fracture surface of the molded article was measured and a number average thereof was regarded as an exposed fiber length. If the fracture surface in the molded article is not a flat surface, the exposed fiber length is calculated by specifying the fracture surface for each of selected fibrous filler.

Examples 1 to 9, Comparative Examples 1 to 9

[0091] A thermoplastic resin (A), a polyrotaxane (B) and, if necessary, an elastomer (D) were mixed so as to obtain the composition shown in Tables 1 and 2, followed by preblending. Using a twin-screw extruder (TEX30, manufactured by The Japan Steel Works, Ltd.) set at extrusion conditions shown in Tables 1 and 2, the thermoplastic resin (A), the polyrotaxane (B) and, if necessary, the elastomer (D) were fed through a main feeder and a fibrous filler (C) was fed through a side feeder, and then the gut ejected from the extruder was pelletized to obtain pellets. The thus obtained pellets were evaluated by the above methods. The results are shown in Tables 1 and 2.

TABLE-US-00001 TABLE 1 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9 Thermoplastic A-1 Nylon 6 Parts by 95 95 90 85 85 85 resin weight A-2 Polybutylene Parts by 95 terephthalate weight A-3 Nylon 66 Parts by 95 weight A-4 Nylon 610 Parts by 95 weight Polyrotaxane B-1 SH2400P Parts by 5 5 5 10 10 10 5 5 5 weight Fibrous filler C-1 Glass fiber Parts by 42.85 (T-249) weight C-2 Glass fiber Parts by 42.85 42.85 42.85 53.85 66.67 42.85 42.85 42.85 (T-253) weight Elastomer D-1 MH5040 Parts by 5 5 5 5 weight Extrusion Cylinder setting C. 240 240 240 240 240 240 240 275 240 conditions temperature Screw speed rpm 100 100 100 100 100 100 100 100 100 Molding Cylinder setting C. 240 240 240 240 240 240 240 275 240 conditions temperature Mold setting temperature C. 80 80 80 80 80 80 80 80 80 Bending test Bending elastic modulus GPa 8.4 8.8 8.6 8.4 8.6 11.1 9.5 9.2 8.5 Fracture morphology no no no no no no no no no fracture fracture fracture fracture fracture fracture fracture fracture fracture Tensile test Tensile elongation at break % 5.6 6.2 9.4 18.1 12.0 6.6 4.3 5.2 7.2 Exposed fiber length mm 0.18 0.20 0.25 0.3 0.26 0.24 0.18 0.19 0.22

TABLE-US-00002 TABLE 2 Com- Com- Com- Com- Com- Com- Com- Com- Com- parative parative parative parative parative parative parative parative parative Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9 Thermo- A-1 Nylon 6 Parts by 100 100 100 plastic weight resin A-2 Polybutylene Parts by 100 100 terephthalate weight A-3 Nylon 66 Parts by 100 100 weight A-4 Nylon 610 Parts by 100 100 weight Polyrotaxane B-1 SH2400P Parts by weight Fibrous C-1 Glass fiber Parts by 42.85 42.85 42.85 42.85 filler (T-249) weight C-2 Glass fiber Parts by 42.85 (T-253) weight Elastomer D-1 MH5040 Parts by weight Extrusion Cylinder setting C. 240 240 240 240 240 240 240 275 240 conditions temperature Screw speed rpm 100 100 100 100 100 100 100 100 100 Molding Cylinder setting C. 240 240 240 240 240 275 275 240 240 conditions temperature Mold setting C. 80 80 80 80 80 80 80 80 80 temperature Bending test Bending elastic GPa 2.8 8.4 2.5 9.5 8.4 2.8 9.4 2.1 8.8 modulus Fracture morphology No Fracture No Fracture Fracture No Fracture No Fracture fracture fracture fracture fracture Tensile test Tensile elongation % 35.0 4.5 30 2.5 4.6 24 2.5 50 2.9 at break Exposed fiber length mm 0.085 0.07 0.087 0.078 0.085