JP5731164B2 - Flat glass fiber-containing thermoplastic resin composition and molded article thereof - Google Patents

Description

  The present invention relates to a resin composition containing a polyamide resin, a graft copolymer and an unsaturated carboxylic acid-modified copolymer, and has impact resistance (high-speed drop) of a weld portion containing glass fibers having a specific flat shape. The present invention relates to a flat glass fiber-containing thermoplastic resin composition excellent in weight impact), heat resistance, rigidity and weld appearance.

  Recently, in vehicle exterior parts and outer plate parts, the use of various plastic materials from metal parts has been promoted to reduce vehicle weight. Conventional resin parts are also required to have high appearance and high design in addition to high functionality. In particular, exterior parts such as bumpers, wheel caps, and spoilers, and outer panel panels such as door panels, front fenders, and tailgate panels are strongly demanded for the impact resistance, heat resistance, and good appearance of molded products.

  Polyamide resins represented by 6-nylon have excellent moldability, heat resistance, impact resistance, chemical resistance, etc., but problems such as reduced impact strength in the dry state, dimensional change due to moisture absorption, and lower tensile strength. have. In addition, rubber-reinforced styrene resin represented by ABS resin also has excellent impact resistance, moldability, gloss, and the like, but has a problem that chemical resistance is inferior.

  In order to maintain the features of polyamide resin and rubber reinforced styrene resin, and to improve the chemical resistance, which is a defect of rubber reinforced styrene resin, and the dimensional change at the time of moisture absorption, which is a defect of polyamide resin, A polymer alloy obtained by blending a copolymer as a compatibilizing agent and a resin composition blended with glass fiber have been proposed (Patent Document 1: JP-A-1-158, Patent Document 2: JP-A-10-10). No. 158508, Patent Document 3: JP 2000-17170 A). However, in order to obtain sufficient rigidity with the conventional glass fiber, a large amount of glass fiber needs to be blended, and there have been practical problems such as a decrease in fluidity and a deterioration in surface appearance. In addition, a resin composition excellent in rigidity, dimensional stability, and surface appearance has been proposed by blending a glass fiber having a specific shape with a polymer alloy containing a polyamide resin and a rubber-reinforced styrene-based resin. There is a problem that the strength and the appearance of the weld part are inferior. (Patent Document 4: Japanese Unexamined Patent Application Publication No. 2009-179675)

JP-A-1-158

JP-A-10-158508

JP 2000-17170 A

JP 2009-179675 A

  The object of the present invention is that it has the characteristics of polyamide resin / rubber reinforced styrene resin alloy, and has excellent impact resistance (high-speed drop impact), heat resistance and rigidity of the weld part, and a practical surface appearance of the weld part. It is in providing the thermoplastic resin composition which has.

That is, the present invention includes 10 to 80 parts by weight of a polyamide resin (A), 20 to 80% by weight of a rubbery polymer, 10 to 70% by weight of an aromatic vinyl monomer, and other monomers copolymerizable therewith. 10 to 80 parts by weight of the graft copolymer (B) obtained by graft polymerization of 10 to 70% by weight of the monomer (based on the graft copolymer (B) (100% by weight)), unsaturated carboxylic acid Obtained by polymerizing 0.5 to 20% by weight of a monomer, 50 to 89.5% by weight of an aromatic vinyl monomer, and 10 to 49.5% by weight of another monomer copolymerizable therewith. 1 to 40 parts by weight of the unsaturated carboxylic acid-modified copolymer (C) (based on the unsaturated carboxylic acid-modified copolymer (C) (100% by weight)), aromatic vinyl monomer 30 to 90% by weight and other monomers copolymerizable therewith (unsaturated carboxylic acids) The copolymer (D) obtained by polymerizing 10 to 70% by weight (excluding the system monomer) is contained in an amount of 0 to 50 parts by weight (based on the copolymer (D) (100% by weight)). The flatness ratio (ratio of major axis / minor axis of the cross section) is 2.0 with respect to 100 parts by weight of the resin composition (the total of (A), (B), (C) and (D) is 100 parts by weight). The present invention provides a flat glass fiber-containing thermoplastic resin composition comprising 1 to 10 parts by weight of glass fiber (E) having the above flat shape.

  The flat glass fiber-containing thermoplastic resin composition of the present invention is excellent in impact resistance (high-speed falling weight impact), heat resistance and rigidity of the weld part, and can provide a practical surface appearance of the weld part. It can be suitably used as an exterior or exterior plate part.

Hereinafter, the flat glass fiber-containing thermoplastic resin composition of the present invention will be described in detail.
The flat glass fiber-containing thermoplastic resin composition of the present invention is obtained by blending 1 to 19 parts by weight of specific glass fibers with respect to 100 parts by weight of a specific resin composition.
The resin composition that can be used in the present invention is polyamide resin (A) 10-80 parts by weight, graft copolymer (B) 10-80 parts by weight, unsaturated carboxylic acid-modified copolymer (C) 1 It is composed of 40 parts by weight and 0 to 50 parts by weight of the copolymer (D) (the total of (A), (B), (C) and (D) is 100 parts by weight). The target composition of the invention cannot be obtained.

  As the polyamide resin (A) constituting the resin composition of the present invention, nylon 3, nylon 4, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 116, nylon 11, nylon 12, nylon 6I, Nylon 6/66, Nylon 6T / 6I, Nylon 6 / 6T, Nylon 66 / 6T, Polytrimethylhexamethylene terephthalamide, Polybis (4-aminocyclohexyl) methane dodecamide, Polybis (3-methyl-4-aminocyclohexyl) methane Examples include dodecamide, polymetaxylylene adipamide, nylon 11T, and polyundecamethylene hexahydroterephthalamide. Note that “I” indicates an isophthalic acid component, and “T” indicates a terephthalic acid component. Of these, nylon 6, nylon 66, nylon 11, and nylon 12 are particularly preferable.

  The polyamide resin (A) needs to be contained in the resin composition in an amount of 10 to 80 parts by weight, but if it is less than 10 parts by weight, the weld strength and heat resistance are poor, and if it exceeds 80 parts by weight, the weld strength is poor. It is not preferable. It is preferably contained in an amount of 20 to 70 parts by weight, and more preferably 25 to 60 parts by weight.

  The graft copolymer (B) constituting the resin composition of the present invention is a rubbery polymer of 20 to 80% by weight, an aromatic vinyl monomer of 10 to 70% by weight and other copolymerizable with this. A graft copolymer obtained by graft polymerization of 10 to 70% by weight of the above monomer (based on the graft copolymer (B) (100% by weight)). From the viewpoint of balance of physical properties of the final composition, from 20 to 70% by weight of the rubbery polymer, 20 to 60% by weight of the aromatic vinyl monomer and 10 to 60% by weight of other monomers copolymerizable therewith. It is preferable to be obtained.

  The rubbery polymer constituting the graft copolymer (B) includes polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer. Polymers, diene (co) polymers such as isobutylene-isoprene copolymers, hydrogenated rubbers of these diene (co) polymers, ethylene-propylene copolymers, ethylene-propylene-nonconjugated diene copolymers Examples thereof include a copolymer, an ethylene-butene-1-nonconjugated diene copolymer, an acrylic rubber, and the like, and one kind or two or more kinds can be used. Of these, polybutadiene, butadiene-styrene copolymer, ethylene-propylene-nonconjugated diene copolymer, and acrylic rubber are preferable, and polybutadiene and butadiene-styrene copolymer are particularly preferable.

  Although there is no restriction | limiting in particular about the weight average particle diameter of a rubber-like polymer, It is preferable that it is 0.05-2.0 micrometers. More preferably, it is 0.10 to 1.0 μm. The rubbery polymer having the particle size may be an emulsion-polymerized rubber (latex) or a rubber (latex) enlarged by mechanically and chemically treating a small particle-size rubber latex by short-time emulsion polymerization. Furthermore, a dissolved rubber obtained by cutting a dry rubber and then dissolving it in a monomer or a solvent is also possible.

  Examples of the aromatic vinyl monomer constituting the graft copolymer (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinyltoluene, methyl-α-methylstyrene, brominated styrene. 1 or 2 or more types can be used, and styrene and α-methylstyrene are particularly preferable.

Other copolymerizable monomers include vinyl cyanide monomers, (meth) acrylic acid ester monomers, unsaturated carboxylic acid monomers, and maleimide monomers. Examples include at least one selected monomer.
Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile, and acrylonitrile is particularly preferable. Examples of the (meth) acrylic acid ester monomer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like, and methyl methacrylate is particularly preferable. Examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid, and the like, and (meth) acrylic acid and (anhydrous) maleic acid are preferable. Examples of the maleimide monomer include maleimide, N-methylmaleimide, N-phenylmaleimide, N- (2-methylphenyl) maleimide, N- (4-hydroxyphenyl) maleimide, N-cyclohexylmaleimide, and the like. In particular, N-phenylmaleimide and N-cyclohexylmaleimide are preferable.

Although there is no restriction | limiting in particular about the grafting rate in a graft copolymer (B), Preferably it is 20 to 150%.
The graft ratio is obtained by the following formula after dissolving the graft copolymer obtained by graft polymerization with acetone and separating it into a soluble part and an insoluble part.
Graft ratio (%) = [weight of acetone-insoluble matter−weight of rubbery polymer in graft copolymer] / [weight of rubbery polymer in graft copolymer] × 100
The graft ratio can be appropriately adjusted by changing the polymerization conditions such as the ratio of the rubbery polymer and the monomer during graft polymerization and the addition rate of the monomer. Moreover, there is no restriction | limiting in particular about the manufacturing method of a graft copolymer (B), The usual well-known methods, such as block polymerization, solution polymerization, block suspension polymerization, suspension polymerization, and emulsion polymerization, are used. From the viewpoint of graft rate, emulsion polymerization is preferred.

  The graft copolymer (B) needs to be contained in the resin composition in an amount of 10 to 80 parts by weight. However, if the amount is less than 10 parts by weight, the weld strength and tensile fracture stress are inferior. Inferior in fracture stress and heat resistance, not preferred. The graft copolymer (B) is preferably contained in an amount of 20 to 70 parts by weight, more preferably 25 to 60 parts by weight. Further, from the viewpoint of balance of physical properties, the content of the rubbery polymer in the resin composition is preferably in the range of 3 to 30% by weight.

  The unsaturated carboxylic acid-modified copolymer (C) constituting the resin composition of the present invention is an unsaturated carboxylic acid monomer of 0.5 to 20% by weight, an aromatic vinyl monomer of 50 to 89. 5% by weight and 10 to 49.5% by weight of other monomers copolymerizable therewith (based on unsaturated carboxylic acid-modified copolymer (C) (100% by weight)) and obtained by polymerization. Copolymer.

Examples of the unsaturated carboxylic acid monomer constituting the unsaturated carboxylic acid-modified copolymer (C) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Although it can be used, methacrylic acid is particularly preferred.
As the aromatic vinyl monomer and other monomers copolymerizable therewith, the same monomers as those exemplified in the section of the graft copolymer (B) can be used.
As other copolymerizable monomers, acrylonitrile, methyl methacrylate and the like are preferable.

In the production of the unsaturated carboxylic acid-modified copolymer (C), a known emulsion polymerization method, bulk polymerization method, suspension polymerization method, or solution polymerization method can be employed.
The reduced viscosity of the unsaturated carboxylic acid-modified copolymer (C) is not particularly limited, but is preferably 0.2 to 1.2 dl / g. The reduced viscosity can be appropriately adjusted depending on the polymerization temperature, the monomer addition method, the initiator used, and the type and amount of a polymerization chain transfer agent such as t-dodecyl mercaptan.

  The unsaturated carboxylic acid-modified copolymer (C) needs to be contained in the resin composition in an amount of 1 to 40 parts by weight, but if it is less than 1 part by weight, the weld strength and the weld appearance are inferior and exceed 40 parts by weight. In addition, the tensile fracture stress and heat resistance are inferior. The unsaturated carboxylic acid-modified copolymer (C) is preferably contained in an amount of 3 to 30 parts by weight, more preferably 5 to 20 parts by weight.

The copolymer (D) that can be used in the present invention is 30 to 90% by weight of an aromatic vinyl monomer and another monomer copolymerizable therewith (however, unsaturated carboxylic acid monomer) This is a copolymer obtained by polymerizing 10 to 70% by weight (based on copolymer (D) (100% by weight)).
As the aromatic vinyl monomer constituting the copolymer (D) and other monomers copolymerizable therewith, the same monomers as those exemplified in the section of the graft copolymer (B) are used. can do.

Styrene is preferred as the aromatic vinyl monomer, and acrylonitrile, methyl methacrylate, and N-phenylmaleimide are preferred as other copolymerizable monomers.
In the production of the copolymer (D), a known emulsion polymerization method, bulk polymerization method, suspension polymerization method, or solution polymerization method can be employed.
The reduced viscosity of the copolymer (D) is not particularly limited, but is preferably in the range of 0.3 to 1.2 dl / g from the viewpoint of physical property balance. The reduced viscosity can be appropriately adjusted depending on the polymerization temperature, the monomer addition method, the initiator used, and the type and amount of a polymerization chain transfer agent such as t-dodecyl mercaptan.

  The glass fiber (E) constituting the flat glass fiber-containing thermoplastic resin composition of the present invention is a glass fiber having a flat shape with a flatness ratio (ratio of major axis / minor axis) of 2.0 or more. If the flatness is less than 2.0, the weld portion is inferior in impact resistance (high-speed drop impact), and the surface appearance of the weld portion of the molded product is also impaired. Preferably it is 2.0-10.0, More preferably, it is 2.5-6.0. Moreover, there is no restriction | limiting in particular about fiber length, However, It is preferable that it is 2-50 mm. As such glass fiber, for example, Nitto Boseki Co., Ltd., modified cross-section glass fiber CSG 3PA-830, CSH 3PA-870 can be obtained.

  The flat glass fiber-containing thermoplastic resin composition of the present invention comprises the polyamide resin (A), the graft copolymer (B), the unsaturated carboxylic acid-modified copolymer (C), and the copolymer (D). 1 to 19 parts by weight of glass fiber (E) having a flat shape with a flatness ratio (ratio of major axis / minor axis) of 2.0 or more is blended with 100 parts by weight of the resin composition to be included. If the content of the glass fiber (E) is less than 1 part by weight, the impact resistance (high-speed falling impact) and heat resistance of the weld part are not sufficient, and if it exceeds 19 parts by weight, the appearance of the molded product weld Since it gets worse, it is not preferable. Preferably it is 3-10 weight part.

  The mixing order and the state of the polyamide resin (A), the graft copolymer (B), the unsaturated carboxylic acid-modified copolymer (C), the copolymer (D) and the glass fiber (E) having a flat shape are as follows: There are no restrictions, and the components remaining after the simultaneous mixing of the components (A), (B), (C), (D) and (E) in the form of powder, pellets, etc. The method of mixing is illustrated. In the melt mixing, a Banbury mixer, a roll, an extruder, or the like can be used.

When mixing, if necessary, other resins such as polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene ether, plant-derived thermoplastic resin represented by polylactic acid and thermoplastic starch, further antioxidants, ultraviolet absorbers, Adds known additives such as light stabilizers, antistatic agents, lubricants, dyes, pigments, plasticizers, flame retardants, release agents, talc, metal fibers, carbon fibers, metal flakes, reinforcing materials, fillers, etc. be able to.
The flat glass fiber-containing thermoplastic resin composition of the present invention can be used as various molded parts, particularly as bumper, wheel cap, spoiler and door panel, front fender, tailgate panel molding as exterior and exterior parts for vehicles. It can be suitably used as a component.

  The present invention is described in detail below. In addition, this invention does not receive a restriction | limiting at all by this. Moreover, both parts and% are shown on a weight basis.

<Polyamide resin (A)>
Unitika Ltd. “Unitika Nylon 6 A1030BRL”

<Graft copolymer B>
Production of polybutadiene rubber latex:
1,3-butadiene 100 parts, t-dodecyl mercaptan 0.3 parts, potassium persulfate 0.25 parts, sodium rosinate 2.5 parts, sodium hydroxide 0.1 parts, pure water 170 The polymerization was started after charging the portion and raising the temperature to 80 ° C. The polymerization was completed in 10 hours. The obtained polybutadiene rubber latex had a solid content of 37% and a weight average particle size of 0.10 μm.

Production of cohesive enlarged polybutadiene rubber latex:
To the glass reactor, 270 parts of polybutadiene rubber latex and 0.1 part of sodium dodecylbenzenesulfonate were added and stirred for 10 minutes, and then 20 parts of 5% aqueous phosphoric acid solution was added over 10 minutes. Subsequently, 10 parts of a 10% aqueous potassium hydroxide solution was added to obtain an agglomerated and enlarged polybutadiene rubber latex having a solid content of 34% and a weight average particle size of 0.33 μm.

A nitrogen-replaced glass reactor was charged with 50 parts of agglomerated polybutadiene rubber latex (solid content), 1.5 parts of sodium dodecylbenzenesulfonate and 0.3 part of potassium persulfate, heated to 70 ° C., and then styrene 35 A monomer mixture consisting of 15 parts by weight and 15 parts of acrylonitrile was continuously added over 5 hours to obtain a graft copolymer latex having a graft rate of 38%.
Thereafter, salting out was performed using sulfuric acid, followed by dehydration and drying to obtain a graft copolymer (B).

<Unsaturated carboxylic acid-modified copolymer (C)>
A glass reactor substituted with nitrogen was charged with 120 parts of pure water and 0.3 part of potassium persulfate, and then heated to 65 ° C. with stirring. Thereafter, a mixed monomer solution composed of 67 parts of styrene, 30 parts of acrylonitrile, 3 parts of methacrylic acid and 1.5 parts of t-dodecyl mercaptan and 30 parts of an emulsifier aqueous solution containing 2 parts of sodium dodecylbenzenesulfonate were continuously added for 5 hours. The polymerization system was then heated to 70 ° C. and aged for 3 hours to complete the polymerization. Then, salting out using calcium chloride, dehydration and drying were performed to obtain an unsaturated carboxylic acid-modified copolymer (C). The reduced viscosity of the obtained unsaturated carboxylic acid-modified copolymer (C) was 0.31 dl / g.

<Copolymer (D)>
A glass reactor substituted with nitrogen was charged with 120 parts of pure water and 0.3 part of potassium persulfate, and then heated to 65 ° C. with stirring. Thereafter, a mixed monomer solution consisting of 70 parts of styrene, 30 parts of acrylonitrile and 0.3 part of t-dodecyl mercaptan and 30 parts of an emulsifier aqueous solution containing 2 parts of sodium dodecylbenzenesulfonate were continuously added for 5 hours each, and then polymerization was performed. The system was heated to 70 ° C. and aged for 3 hours to complete the polymerization. Then, salting out using sulfuric acid, dehydration and drying were performed to obtain a copolymer (D). The reduced viscosity of the obtained copolymer (D) was 0.60 dl / g.

<Flat shape glass fiber (E)>
E-1: Chopped strand CSG 3PA-830 manufactured by Nitto Boseki Co., Ltd., flatness ratio = 4
E-2: Chopped strand CSH 3PA-870 manufactured by Nitto Boseki Co., Ltd., flatness ratio = 2
E-3: Chopped strand RES03-TP89Z manufactured by Owens Corning Japan, flatness ratio = 1

[Examples and Comparative Examples]
Based on the composition ratios shown in Tables 1 and 2, the above polyamide resin (A), graft copolymer (B), unsaturated carboxylic acid-modified copolymer (C), copolymer (D) and glass fiber ( E) was kneaded at once with a twin screw extruder (set temperature: 250 ° C.) and pelletized to obtain various compositions.

  Tables 1 and 2 show the results obtained by preparing various test pieces from the various compositions thus obtained using an injection molding machine (set temperature: 250 ° C., mold temperature: 60 ° C.) and evaluating physical properties. In addition, each evaluation method is shown below.

(1) Impact resistance of the weld part (high-speed falling weight impact): obtained by injection molding with a flat plate making mold with dimensions of 90 mm x 150 mm x 3 mmt with a two-point gate and a central weld site The flat plate was allowed to stand in a constant temperature room at 23 ° C. and 50% RH for 24 hours. Using a high-speed drop weight tester manufactured by Toyo Seiki, a drop jig with a circular tip shape and a radius of 1/4 inch is placed on the weld part in the center of the molded product at -30 ° C and a weight of 7.5 kg from a height of 20 cm. The weight was dropped (impact speed 2 m / s) and the evaluation was performed. Unit: J
(2) Tensile fracture stress: conforming to ISO 527. Unit: MPa
(3) Heat resistance (deflection temperature under load): ISO 75 compliant (0.46 MPa). Unit: ° C
(4) Surface appearance of weld part: injection molding was performed with a flat plate making mold having a dimension of 90 mm × 150 mm × 1 mmt having a two-point gate and having a weld part in the center. It was left to stand in a% RH constant temperature room for 24 hours. The surface appearance of the central weld part of the molded product was observed and judged with a digital microscope (Keyence Co., Ltd., VHX-100F).
○: A weld line can be seen in the weld part but hardly noticeable △; a weld line can be seen in the weld part, and the weld line is slightly noticeable X: A weld line can be seen in the weld part, and the weld line is quite noticeable

  As shown in Tables 1 and 2, the flat glass fiber-containing thermoplastic resin composition of the present invention balances the impact resistance (high-speed drop impact) and heat resistance, rigidity, and surface appearance of the weld part of the weld part. Excellent results were excellent. It can also be seen that the glass fiber having a resin composition and a flat shape in a specific range is particularly excellent in the balance of physical properties and the surface appearance of the weld portion.

As shown in Comparative Example 1, when the flat glass fiber (E) is not contained, the impact resistance (high-speed drop impact) and heat resistance of the weld portion are low, which is not preferable. As shown in Comparative Example 2, when the content of the flat glass fiber (E) exceeds 19 parts by weight, the appearance of the molded product weld is deteriorated, which is not preferable. As shown in Comparative Example 3, when the flatness ratio of the flat glass fiber (E) is less than 2.0, the weld portion is inferior in impact resistance (high-speed drop impact), and the surface appearance of the weld portion of the molded product is also impaired. Therefore, it is not preferable. As shown in Comparative Example 4, when the polyamide resin (A) is less than 10 parts, the weld part has poor impact resistance (high-speed drop impact) and heat resistance, which is not preferable.

  Since the flat glass fiber-containing thermoplastic resin composition of the present invention is excellent in impact resistance, heat resistance, rigidity and surface appearance of the weld part of the weld part, exterior parts and door panels such as bumpers, wheel caps, spoilers, It can be suitably used for an outer panel such as a front fender and a tailgate panel.

Claims (2)

10 to 80 parts by weight of the polyamide resin (A), 20 to 80% by weight of the rubbery polymer, 10 to 70% by weight of the aromatic vinyl monomer and 10 to 70% of other monomers copolymerizable therewith % Of the graft copolymer (B) obtained by graft polymerization of 10% by weight (based on the graft copolymer (B) (100% by weight)), an unsaturated carboxylic acid monomer Unsaturated carboxylic acid modification obtained by polymerizing 5 to 20% by weight, aromatic vinyl-based monomer 50 to 89.5% by weight and other monomer 10 to 49.5% by weight copolymerizable therewith 1 to 40 parts by weight of copolymer (C) (based on unsaturated carboxylic acid-modified copolymer (C) (100% by weight)), 30 to 90% by weight of aromatic vinyl monomer, and Other copolymerizable monomers (excluding unsaturated carboxylic acid monomers) 0 to 50 parts by weight of a copolymer (D) obtained by polymerizing 0 to 70% by weight (based on the copolymer (D) (100% by weight)) 100 parts by weight of a resin composition (( A), (B), (C) and (D) are 100 parts by weight.) A glass fiber having a flat shape with a flatness ratio (ratio of major axis / minor axis) of 2.0 or more. (E) 1-10 weight part is mix | blended, The flat glass fiber containing thermoplastic resin composition characterized by the above-mentioned.
A molded article which is a vehicle exterior and outer plate part obtained from the flat glass fiber-containing thermoplastic resin composition according to claim 1.