JP2018172467A - Polypropylene resin composition and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene-based resin composition capable of producing a molded product with an embossed pattern which hardly causes scratches and shine scratches, is excellent in mechanical characteristics, and shows less change in an embossed state even under a high temperature condition.SOLUTION: There are provided a propylene-based resin composition which contains 45-85 parts of a propylene-ethylene random copolymer or a propylene homopolymer (A) having an MFR of 5-100 g/10 min, having an ethylene content not exceeding 1.3 mass%, and Mw/Mn of 1.8-3.5, 5-25 parts of an ethylene-α-olefin (3 to 10 carbon atoms) copolymer (B) having an MFR of 0.1-30 g/10 min, 10-30 parts of a fibrous filler (C) having an average fiber length of 0.1-2 mm, 0.01-1.0 part of a lubricant (D), and 0.1-3 parts of modified polypropylene (E); and a molded body such as automobile interior and exterior parts formed from the resin composition.SELECTED DRAWING: None

Description

  The present invention relates to a propylene-based resin composition capable of producing a molded article with a texture pattern having excellent mechanical properties and scratch resistance.

  Molded articles obtained by injection molding a propylene-based resin composition are used in various fields such as automobile parts and household appliance parts due to their excellent mechanical properties, moldability, and economy.

  In the automotive parts field, in addition to using polypropylene alone, polypropylene-ethylene-propylene copolymer (EPR), ethylene-butene copolymer (EBR), ethylene-octene copolymer (EOR), styrene-butadiene copolymer (SBR), materials improved in impact by adding rubber components such as polystyrene-ethylene / butene-polystyrene triblock copolymer (SEBS) (see Patent Documents 1 and 2), talc, mica, glass fiber, etc. A material in which an inorganic filler is added to improve rigidity, and a blend polymer to which a rubber component and an inorganic filler are added to give excellent mechanical properties are used.

  On the other hand, polypropylene molded products are generally known to have low scratch resistance. Scratches generated in polypropylene molded products include scratches caused by scraping the surface of the molded product with a sharp tip, and the surface of the molded product is pressed or rubbed by a wide object, large object or soft object. There are shining scratches and the like caused by being.

  Conventionally, vinyl chloride resins having a textured pattern have been used for molded articles such as automobile dashboards, and recently molded articles made of polyolefin resin have begun to be used. However, as the overall performance of the automobile increases, the usable period of the automobile extends, and the surface of a dashboard or the like in which outdoor rays are directly irradiated through a windshield or the like is exposed to a long thermal history. It was. As a result, problems such as a wrinkle pattern on the dashboard surface and a rise in gloss due to shine are becoming obvious. Patent Document 3 discloses a propylene-based resin composition capable of producing a molded article having excellent mechanical properties and scratch resistance, but the problem of suppressing changes in the textured state under high temperature conditions has been studied. Further, the composition of the molecular weight distribution and the ethylene content of the component (A) is different from the present invention described later.

JP 2006-307015 A JP 2006-316103 A International Publication No. 2015/005239

  An object of the present invention is to provide a propylene-based resin composition that can produce a molded article with a wrinkle pattern that is less likely to cause scratches, shine, and the like, has excellent mechanical properties, and has little change in wrinkle state even under high temperature conditions. Is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors use the following propylene-based resin composition so that scratches and shining scratches are less likely to occur, and further, molding with a wrinkle pattern having excellent mechanical properties. The present invention was completed by finding that this propylene resin composition is suitable for producing automobile interior and exterior parts and the like.

That is, the propylene-based resin composition of the present invention is
Including the following (A) to (E), when the total content of (A) to (C) is 100 parts by mass, the content of (A) is 45 to 85 parts by mass, the content of (B) Is 5 to 25 parts by mass, (C) is 10 to 30 parts by mass, (D) is 0.01 to 1.0 parts by mass, and (E) is 0.1 to 3 parts by mass. Part of a propylene-based resin composition.
(A) Based on ASTM D1238, the melt flow rate measured under the conditions of a test load of 2.16 kg and a test temperature of 230 ° C. is 5 to 100 g / 10 minutes, and the content ratio of the structural units derived from ethylene to all structural units is From propylene-ethylene random copolymer or propylene homopolymer (B) ethylene having a Mw / Mn of 1.8 to 3.5 not exceeding 1.3 mass% and an α-olefin having 3 to 10 carbon atoms It is a copolymer with one or more selected α-olefins, and has a melt flow rate of 0.1 to 30 g / 10 measured under the conditions of a test load of 2.16 kg and a test temperature of 190 ° C. in accordance with ASTM D1238. Minute, ethylene-α-olefin copolymer (C) fibrous filler (D) lubricant (E) modified polypropylene having an average fiber length of 0.1 to 2 mm

  In the present invention, (A) the propylene-ethylene random copolymer or the propylene homopolymer is a propylene-ethylene random copolymer, and the content ratio of structural units derived from ethylene to all structural units is 0.1 mass. % Or more and preferably not exceeding 1.3% by mass.

  In this invention, it is preferable that the content ratio of the structural unit derived from the alpha olefin with respect to all the structural units of a copolymer is 5-60 mol% in the (B) ethylene-alpha-olefin copolymer.

  In the present invention, (C) the fibrous filler is preferably a glass fiber filler.

  In the present invention, (B) one type in which the structural unit derived from α-olefin constituting the ethylene-α-olefin copolymer is selected from structural units derived from propylene, 1-butene, 1-hexene and 1-octene. The above is preferable.

  In the present invention, (D) the lubricant is preferably erucic acid amide.

  In the present invention, (E) the modified polypropylene is preferably maleic anhydride-modified polypropylene.

  A molded body such as an automobile interior / exterior part can be formed from the propylene-based resin composition of the present invention.

  According to the present invention, propylene that is excellent in scratch resistance and mechanical properties, in particular, rigidity and impact resistance, and that can produce a molded product that can maintain a stable texture pattern even when held at high temperatures for a long period of time. It becomes possible to provide a resin-based resin composition.

  Hereinafter, the present invention will be specifically described.

  The propylene-based resin composition of the present invention has the following characteristics: (A) propylene-ethylene random copolymer or propylene homopolymer, (B) ethylene-α-olefin copolymer, (C) fibrous filler, D) a lubricant, and (E) a modified polypropylene. Hereinafter, each component and components that may optionally be included will be described in detail.

<(A) Propylene-ethylene random copolymer or propylene homopolymer>
In the present invention, among the components (A), the propylene-ethylene random copolymer is obtained by copolymerizing propylene and ethylene.

  (A) Propylene-ethylene random copolymer or propylene homopolymer, measured in accordance with ASTM D1238, with a test load of 2.16 kg and a test temperature of 230 ° C., the melt flow rate is preferably 5 to 100 g / 10 min. Is 5 to 75 g / 10 min, more preferably 5 to 50 g / 10 min. If the melt flow rate is less than 5 g / 10 min, the resin fluidity at the time of molding is poor, and when molding a large molded product such as an instrument panel or door trim, the resin may not be filled up to the details of the mold. On the other hand, if the melt flow rate is greater than 100 g / 10 min, sufficient impact properties are not exhibited in the molded product.

  (A) The content ratio of the structural unit derived from ethylene to the total structural unit of the copolymer in the propylene-ethylene random copolymer or the propylene homopolymer does not exceed 1.3% by mass. When a propylene-ethylene random copolymer is used as the component (A), the content ratio of the structural unit derived from ethylene is preferably 0.1% by mass or more and does not exceed 1.3% by mass, more preferably 0.1%. It is -1.2 mass%. Whether to use a copolymer or a homopolymer as the component (A) is appropriately selected depending on which item in the performance of the molded body has priority. That is, a propylene homopolymer is preferably used when emphasizing the mechanical strength of the molded body, and a propylene-ethylene random copolymer is preferably used when emphasizing the heat resistance of the grain gloss of the molded body. In addition, the content ratio of the structural unit derived from ethylene in the copolymer can be measured by infrared spectroscopy or NMR. When the content ratio is 1.3% by mass or more, the balance between the impact resistance and the rigidity of the molded product tends to deteriorate, and the grain gloss after the heat history tends to slightly increase.

  In the present invention, the (A) propylene-ethylene random copolymer or propylene homopolymer is polymerized using an olefin polymerization catalyst.

  Although the said olefin polymerization catalyst is not specifically limited, The catalyst for olefin polymerization containing (a) the transition compound of the periodic table group IV containing the ligand which has a specific fluorenyl skeleton, and (b) the organoaluminum oxy compound. Those polymerized by use are preferred.

  In the present invention, the molecular weight distribution (Mw / Mn) of (A) propylene-ethylene random copolymer or propylene homopolymer is 1.5 to 3.5, preferably 1.6 to 3.4. Preferably it is 1.8-3.3. This molecular weight distribution (Mw / Mn) is determined by gel permeation chromatography (GPC). Specifically, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the polydispersity (Mw / Mn) of polypropylene (PP) by GPC were measured by a gel permeation chromatograph (GPC) HLC-8321GPC / manufactured by Tosoh Corporation. Measurement was performed as follows using an HT type.

  The separation column is composed of four TSKgel GMH6-HT and TSKgel GMH6-HTL connected in series, the column size is 7.5 mm in inner diameter and 300 mm in length, the column temperature is 140 ° C., and the mobile phase has a concentration of 0. Using o-dichlorobenzene (manufactured by Wako Pure Chemical Industries) containing the antioxidant BHT (manufactured by Wako Pure Chemical Industries) at 25 g / kg, the sample was moved at 1.0 mL / min, and a typical sample concentration was 1.5 mg / kg. The sample injection volume was 400 L, and a differential refractometer was used as a detector. For column calibration, standard polystyrene with a molecular weight in the range of 500 to 20.6 million manufactured by Tosoh Corporation is used, the relation between the common logarithm of polystyrene (PS) molecular weight and retention time is approximated by a polynomial, and the PS-converted molecular weight is determined from the polynomial, In combination with the general calibration concept, the PE equivalent molecular weight and the PP equivalent molecular weight were determined.

The concept of general-purpose calibration was proposed by Z. Grubisic et al. (J. Polym. Sci., Part B, 5, 753 (1967)). Today, it is a concept that is widely used in molecular weight calculations and is necessary for conversion. The Mark-Houwink coefficients for PS, PE, and PP are the literature (J. Polym. Sci., Part A-2, 8, 1803 (1970), Eur. Polym. J., 7, 1537 (1971), Makromol, respectively. Chem., 177, 213 (1976)) the following values were used.
PS coefficient: Kps = 1.38 × 10−4, ps = 0.70
PP coefficient: Kpp = 2.42 × 10−4, pp = 0.707

  In the present invention, when a propylene-ethylene random copolymer is used as the component (A), the elastic recovery and flexibility are higher than when a propylene homopolymer is used. Even if the wound is caused by an external force, the wound is repaired to some extent and tends to be inconspicuous.

<(B) Ethylene-α-olefin copolymer>
In the present invention, the (B) ethylene-α-olefin copolymer is obtained by copolymerizing ethylene and one or more α-olefins selected from α-olefins having 3 to 10 carbon atoms. The α-olefin is preferably selected from propylene, 1-butene, 1-hexene and 1-octene. The α-olefin may be used alone or in combination of two or more. . Use of these monomers is particularly preferred from the viewpoint of elastic recovery, flexibility and scratch resistance.

  (B) The melt flow rate of the ethylene / α-olefin copolymer measured under the conditions of a test load of 2.16 kg and a test temperature of 190 ° C. in accordance with ASTM D1238 is 0.1 to 30 g / 10 minutes, preferably 1. -20 g / 10 min, more preferably 1-10 g / 10 min. When the melt flow rate is less than 0.1 g / 10 minutes, the resin fluidity is lowered and the dispersion is not good at the time of kneading, which leads to deterioration of physical properties such as impact resistance of the molded product and deterioration of the molded product surface appearance. On the other hand, if it exceeds 30 g / 10 minutes, sufficient impact resistance cannot be obtained for the molded product, and glossiness after the thermal history of the surface of the molded product is increased, which is not preferable.

  (B) The content ratio of the structural unit derived from α-olefin to the total structural unit of the copolymer in the ethylene-α-olefin copolymer is preferably 5 to 60 mol%, more preferably 7 to 50 mol%, particularly preferably. Is 10 to 45 mol%.

  (B) The ethylene-α-olefin copolymer is preferably an ethylene-octene copolymer or an ethylene-butene copolymer.

<(C) Fibrous filler>
In the present invention, the (C) fibrous filler includes, for example, carbon fiber (carbon fiber), carbon nanotube, basic magnesium sulfate fiber (magnesium oxysulfate fiber), potassium titanate fiber, aluminum borate fiber, calcium silicate. Fiber, calcium carbonate fiber, glass fiber, silicon carbide fiber, wollastonite, zonotlite, various metal fibers, natural fibers such as cotton, celluloses, silk, wool and hemp, regenerated fibers such as rayon and cupra, acetate and promix And the like, synthetic fibers such as polyester, polyacrylonitrile, polyamide, aramid and polyolefin, and modified fibers whose surfaces and ends are chemically modified.

  Among these, celluloses such as nanocellulose and TEMPO-oxidized nanocellulose; glass fibers; carbon fibers; carbon nanotubes such as single wall carbon nanotubes and multiwall carbon nanotubes are included in the resin composition and resin composition of the present invention. The molded product is preferable from the viewpoints of molding appearance, physical property balance, imparting dimensional stability (reducing linear expansion coefficient, etc.), adaptability to various performances required for dimensions and physical properties, and the like.

  Furthermore, among these, glass fiber, carbon fiber, and cellulose are most preferably used because they are versatile, have excellent availability, and are inexpensive.

  The average fiber length of the (C) fibrous filler contained in the propylene-based resin composition of the present invention is 0.1 to 2 mm, preferably 0.3 to 1.5 mm, and more preferably 0.4 to 1. 3 mm.

  (C) Although the average fiber length of a fibrous filler is a numerical value of the fibrous filler in the state contained in the propylene-type resin composition, as a fibrous filler before making it contain in a composition, average fiber length is The thing of about 0.1-10 mm can be illustrated. The fibrous filler having these sizes before preparation of the composition becomes a size within the above range by cracking during the preparation of the propylene-based resin composition described later. Further, the average fiber diameter of the fibrous filler before being contained in the composition is not limited as long as it is a fiber diameter of a generally used fibrous filler, but is usually 1 to 25 μm, preferably 5 to 17 μm, more preferably. Is 8-15 μm. Moreover, the average fiber diameter of the fibrous filler in a composition is substantially equivalent to the average fiber diameter before making it contain in a composition.

  (C) The average fiber length of the fibrous filler can be measured as follows. The sample is processed in an electric furnace at 600 ° C. for 3 hours to be incinerated, and the incinerated product is image-processed with an image processor (for example, LUZEX (registered trademark) -AP, manufactured by Nireco Co., Ltd.). And the weight average fiber length calculated from the length is taken as the average fiber length.

  (C) The form of the raw material for supplying the fibrous filler is a short fiber shape, a long fiber shape, a cloth shape, a sheet shape hardened by paper-making like paper, a compressed soul shape, a granular shape, etc. You may use what was done. In particular, a short fiber shape, a long fiber shape, a cloth shape, and a paper sheet shape are easily used because they are easy to handle and the performance as a material is easily improved. In general, a cloth-like or paper-made sheet is preferable because it can be expected to bond fibers, and is extremely effective in improving the strength of the material.

  (C) As the fibrous filler, for the purpose of improving the dispersibility in the resin composition or the adhesiveness with (A) propylene-ethylene random copolymer or propylene homopolymer which is a crystalline resin, Various organic titanate coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or modified polyolefins grafted with anhydrides thereof, fatty acids, fatty acid metal salts, fatty acid esters and the like may be used. . Alternatively, there may be no problem even if the surface is treated with a thermosetting or thermoplastic polymer component and modified.

  In addition, (C) fibrous filler may be used independently and may be used together 2 or more types.

<(D) Lubricant>
In the present invention, examples of the (D) lubricant include fatty acid amides. Examples of the fatty acid residue of the fatty acid amide include residues derived from saturated and unsaturated fatty acids having about 15 to 30 carbon atoms. Specific examples of fatty acid amides include oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, palmitic acid amide, myristic acid amide, lauric acid amide, caprylic acid amide, caproic acid amide, n-oleyl palmitoamide. , N-oleyl erucamide, and a dimer thereof. These lubricants are preferable for improving the stickiness feeling in use, which is characteristic when (A) a propylene-ethylene random copolymer or a propylene homopolymer is used, and erucic acid amide is particularly preferable. These can be used alone or in admixture of two or more.

<(E) Modified polypropylene>
In the present invention, (E) modified polypropylene is obtained by acid-modifying polypropylene. Examples of methods for modifying polypropylene include graft modification and copolymerization.

  Examples of modifying agents used for modification include unsaturated carboxylic acids and derivatives thereof. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, angelic acid, and phthalic acid. Examples of the derivatives include acid anhydrides, esters, amides, imides, and metal salts. For example, maleic anhydride, itaconic anhydride, citraconic anhydride, nadic anhydride, phthalic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, maleic acid monoamide, Maleimide, N-butylmaleimide, sodium acrylate, sodium methacrylate and the like can be mentioned. Among these, unsaturated dicarboxylic acids and derivatives thereof are preferable, and maleic anhydride and phthalic anhydride are particularly preferable.

  When acid-modifying in the melt-kneading process, the unsaturated carboxylic acid or derivative thereof is graft-copolymerized and modified by kneading polypropylene and unsaturated carboxylic acid or derivative thereof together with an organic peroxide in an extruder.

  Examples of the organic peroxide include benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, dicumyl peroxide, t-butyl hydroperoxide, α, α′-bis (t-butylperoxydiisopropyl). Benzene, bis (t-butyldioxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) ) Hexin-3, di-t-butyl peroxide, cumene hydroperoxide and the like.

  The present invention is effective, for example, in improving the affinity between glass fiber and propylene-based resin, and may be particularly effective in increasing rigidity. From that viewpoint, anhydrous fatty acid-modified polypropylene is preferable as (E) modified polypropylene. In particular, maleic anhydride-modified polypropylene is preferred.

  (E) When maleic anhydride-modified polypropylene is used as the modified polypropylene, the amount of maleic anhydride-modified polypropylene used is such that the maleic acid-modified group content (M value) is 0.1 with respect to 100 parts by mass of the propylene-based resin composition. The amount is preferably 5 to 5.0 parts by mass, more preferably 0.8 to 2.5 parts by mass. When the amount used is lower than this range, the effect of improving the scratch resistance on the molded product is not recognized, and when it is high, the impact strength in the mechanical properties of the molded product may be lowered. This M value is obtained from an infrared absorption spectrum. 2 g of the acid-modified resin is collected, dissolved by heating in 500 ml of boiling p-xylene completely, cooled, put into 1200 ml of acetone, and the precipitate is filtered and dried to obtain a purified polymer. A film having a thickness of 20 μm was produced from the purified product by hot pressing, the infrared absorption spectrum of the film was measured, and the content of the acid used for modification was measured from the absorption specific to the acid used for modification. The absorption specific to the acid used for modification is around 1780 cm @ -1 for maleic anhydride.

  (E) The intrinsic viscosity [η] measured in 135 ° C. decalin of the base polypropylene constituting the modified polypropylene is usually 0.2 to 2.0 dl / g, more preferably 0.4 to 1.0 dl. / G.

  Specific examples of the maleic anhydride-modified polypropylene include Admer (registered trademark) manufactured by Mitsui Chemicals, Umex (registered trademark) manufactured by Sanyo Chemical Industries, MZ series manufactured by DuPont, Excellor (registered trademark) manufactured by Exxon, and Chem. Commercial products such as Chura Japan Co., Ltd. polybond PB3200 can be used.

<Other ingredients>
In the propylene-based resin composition of the present invention, if necessary, a heat resistance stabilizer, an antistatic agent, a weather resistance stabilizer, a light resistance stabilizer, an antiaging agent, an antioxidant, a fatty acid metal salt, a softening agent, a dispersing agent, Other additives such as a filler, a colorant, and a pigment can be blended as long as the object of the present invention is not impaired. The mixing order of additives to be blended is arbitrary, and may be mixed at the same time, or a multistage mixing method in which some components are mixed and then other components are mixed.

<Propylene-based resin composition>
The propylene-based resin composition of the present invention is produced by blending the components (A), (B), (C), (D) and (E) described above and other additives as necessary. be able to. Each of these components can be blended in any order.

  In the propylene-based resin composition of the present invention, the melt flow rate measured under the conditions of a test load of 2.16 kg and a test temperature of 230 ° C. is 10 g / 10 min or more and 70 g / 10 min or less in accordance with ASTM D1238. In particular, it is preferably 10 g / 10 min or more and 45 g / 10 min or less.

  The blending ratio of the above components in the propylene-based resin composition of the present invention is (A): 45 to 85 parts by mass when the total of components (A), (B) and (C) is 100 parts by mass. (B) 5 to 25 parts by mass, (C): 10 to 30 parts by mass, (D): 0.01 to 1.0 parts by mass, and (E): 0.1 to 3 parts by mass.

  The compounding quantity of a component (A) becomes like this. Preferably it is 45-85 mass parts, More preferably, it is 55-75 mass parts. When the blending amount of the component (A) is less than 45 parts by mass, the scratch resistance of the molded product such as shine scratches is lowered. Moreover, when the compounding quantity of a component (A) is larger than 85 mass parts, the rigidity of a molded product will fall.

  The compounding quantity of a component (B) becomes like this. Preferably it is 7-25 mass parts, More preferably, it is 8-23 mass parts. When the blending amount of the component (B) is less than 5 parts by mass, the molded article cannot obtain sufficient impact resistance. Moreover, when the compounding quantity of a component (B) is larger than 25 mass parts, the rigidity (tensile modulus) of a molded product will fall.

  The amount of component (C) is preferably 20 to 30 parts by mass. When the amount of component (C) is less than 10 parts by mass, the rigidity (tensile modulus) of the molded product is reduced. Moreover, when the compounding quantity of a component (C) exceeds 30 mass parts, since the surface external appearance of a molded article may deteriorate, and since it is a fibrous filler, shrinkage | contraction rate of MD direction and TD direction of a molded article is Anisotropy is likely to occur, and there is a possibility of warping of the molded product.

  The amount of component (D) is preferably 0.05 to 0.7 parts by mass, more preferably 0.1 to 0.5 parts by mass. If the blending amount of component (D) is less than 0.01 parts by mass, sufficient scratch resistance may not be obtained for the molded product. Moreover, when the compounding quantity of a component (D) is larger than 1.0 mass part, fogging property may deteriorate.

  The amount of component (E) is preferably 0.5 to 2 parts by mass, more preferably 0.5 to 1.5 parts by mass. When the blending amount of the component (E) is less than 0.1 part by mass, the dispersibility of the fibrous filler is lowered, and mechanical properties such as impact properties and rigidity of the molded product may be adversely affected. Moreover, when the compounding quantity of a component (E) is larger than 3 mass parts, the impact property of a molded article falls.

  The propylene-based resin composition of the present invention contains (A) a propylene-ethylene random copolymer or a propylene homopolymer as an essential component. Since the component (A) is a relatively flexible material, the molded product containing the polymer is elastically recovered even if it is damaged by other objects, so it is confirmed that there is little change in the surface of the molded product substrate. ing. This feature is believed to improve scratch resistance.

  In addition, since the component (A) is a material having a low crystallization temperature, when forming a textured shape on the surface of the molded product, the composition does not solidify until the shape is sufficiently transferred, so that the texture transferability is improved. It is considered that the gloss on the surface of the molded article is reduced, and it is possible to suppress shine damage.

  The propylene-based resin composition of the present invention includes (C) a fibrous filler in addition to the component (A), thereby supplementing the flexibility of the component (A) and having an excellent balance between rigidity and impact resistance. Finished.

  The propylene-based resin composition of the present invention comprises the above components (A), (B), (C), (D) and (E), and other additives to be blended as necessary. It can be obtained by mixing or melt-kneading with a mixing device such as a mixer, a single screw extruder, a twin screw extruder, or a high speed twin screw extruder.

  The propylene-based resin composition of the present invention is particularly suitably used for injection molding. Molded articles obtained by injection molding the propylene-based resin composition of the present invention have excellent mechanical properties and resistance to scratches such as scratches and shining scratches, and are stable even when held at high temperatures for a long period of time. Can maintain a smooth texture.

  Such a propylene resin composition of the present invention can be suitably used in various fields such as automobile interior and exterior parts.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

  The measurement of the properties of each component and the propylene resin composition of the present invention, and the evaluation of the propylene resin composition and molded product of the present invention were performed as follows.

(1) Measurement of melt flow rate The melt flow rate is in accordance with ASTM D1238, with a test load of 2.16 kg, a test temperature of 230 ° C. [component (A) and the entire resin composition] or 190 ° C. [component (B)]. Measured under conditions.

(2) Measurement of modifying group content 2 g of acid-modified resin was sampled and completely dissolved by heating in 500 ml of boiling p-xylene. After cooling, it was put into 1200 ml of acetone, and the precipitate was filtered and dried to obtain a purified polymer. The purified polymer was hot-pressed to produce a film having a thickness of 20 μm. The infrared absorption spectrum of the produced film was measured, and the content of the acid used for modification was measured from the specific absorption of the acid used for modification. The characteristic absorption of the acid used for modification is around 1780 cm ⁻¹ for maleic anhydride.
(3) Measurement of molecular weight distribution (Mw / Mn) The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) was determined by gel permeation chromatography (GPC).

(4) Measurement of room temperature Charpy impact strength (kJ / m ² ) Based on ISO 179, room temperature Charpy impact strength was measured under the conditions of notch and hammer capacity of 4J.

(5) Measurement of tensile elastic modulus Based on ISO 527, the tensile elastic modulus was measured under the condition of a tensile speed of 1 mm / min.

(6) Measurement of grain gloss A mold with a cavity size of 130 mm in length, 120 mm in width, and 2 mm thickness on the cavity surface with a skin texture (depth of 90 μm) is set to 40 ° C, and the resin temperature is set to 210 ° C and injection molding is performed. The grain surface of the molded product obtained in this manner was measured for grain gloss with a gloss meter (UNIGLOSS 60 manufactured by Konica Minolta Co., Ltd.) at a light source irradiation angle of 60 °. Next, the same grain gloss was also measured on the test piece after aging the test piece in a thermostatic bath at 110 ° C. and 120 ° C. for 400 hours.

(7) Evaluation of shine damage resistance Set a mold with a cavity size of 130 mm in length, 120 mm in width, 2 mm in thickness and a cavity surface (depth: 90 μm) processed to 40 ° C and a resin temperature of 210 ° C. Tests the textured surface of the molded product obtained by injection molding for Ford 5-Finger Test (needle tip R: 7 mm, test load: 0.6, 2, 3, 5, 7, 10, 15, 20 N) Then, using a Weld-Line-Tester (FW-098 manufactured by Nippon Denshoku Industries Co., Ltd.), the gross change rate of the scar part and the unscratched part ([gross of scar part] / [gross of unscratched part]) Was measured. It is evaluated that the smaller the rate of change in gloss, the higher the resistance to shine damage.

  In the following examples and comparative examples, each component used is as follows.

<(A) Propylene-ethylene random copolymer or propylene homopolymer>
(A-1) Propylene homopolymer MFR: 60 g / 10 min, molecular weight distribution: 2.7
(A-2) Propylene / ethylene random copolymer MFR: 60 g / 10 min, structural unit content derived from ethylene content: 1.0 mass%, molecular weight distribution: 2.7
(A-3) Propylene / ethylene random copolymer MFR: 60 g / 10 min, structural unit content derived from ethylene content: 2.2 mass%, molecular weight distribution: 2.4
(A-4) Propylene / ethylene random copolymer MFR: 60 g / 10 min, structural unit content derived from ethylene content: 1.0 mass%, molecular weight distribution: 6.1

<(B) ethylene / α-olefin copolymer>
(B-1) Ethylene / 1-butene random copolymer (product name: A35070, manufactured by Mitsui Chemicals, Inc. may be abbreviated as TF-1 in the following description)
MFR (190 ° C.): 35 g / 10 min
(B-2) ethylene / 1-butene random copolymer (product name: A4050S, manufactured by Mitsui Chemicals, Inc. may be abbreviated as TF-2 in the following description)
MFR (190 ° C.): 3.6 g / 10 min
(B-3) ethylene / 1-butene random copolymer (product name: A1050S, manufactured by Mitsui Chemicals, Inc. may be abbreviated as TF-3 in the following description)
MFR (190 ° C): 1.2 g / 10 min

<(C) Fibrous filler>
Glass fiber filler (Nippon Electric Glass Industrial Co., Ltd. product name: T-480, average fiber length 3 mm, average fiber diameter 13 μm)

<(D) Lubricant>
Erucamide (Nitrone (registered trademark) S manufactured by Nippon Seika Co., Ltd.)

<(E) Modified polypropylene>
Maleic anhydride-modified polypropylene (product name: Polybond PB3200 manufactured by Chemtura Japan Co., Ltd.), acid-modified group content: 0.4% by mass

  In addition, the propylene homopolymer or the propylene / ethylene random copolymer of (A-1) to (A-3) is a specification filed by the present applicant and published as International Publication No. 2010/5239. Presence of a catalyst combining diphenylmethylene (3-t-butyl-5-methylcyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride and methylaluminoxane based on the described formulation Below, it is a polymer obtained by homopolymerizing propylene or copolymerizing propylene and ethylene.

The propylene / ethylene random copolymer (A-4) is also based on the prescription described in the specification published as International Publication No. 2010/5239, and a magnesium chloride-supported TiCl ₄ catalyst and triethyl. It is a polymer polymerized using aluminum.

[Examples 1-3 and Comparative Examples 1-4]
Each component showing the blending ratio (parts by mass) in Table 1, and 0.1 parts by mass of IRGANOX (registered trademark) 1010 manufactured by Ciba Specialty Chemicals Co., Ltd. as an antioxidant, ) 0.1 parts by mass of IRGAFOS168 manufactured by Ciba Specialty Chemicals, 0.15 parts by mass of LA-402AF manufactured by ADEKA Co., Ltd. as a light-resistant stabilizer, and 0 tinbin (registered trademark) manufactured by BASF as a light-resistant stabilizer .10 parts by mass, dry blended with a Henschel mixer, barrel temperature (kneading temperature) 210 ° C., screw by twin screw extruder (NR-II manufactured by Nakatani Machinery Co., Ltd., co-rotating twin screw extruder) Kneading and extrusion were performed under the conditions of a rotation speed of 200 rpm and an extrusion rate of 20 kg / h, and the propylene resins of Examples 1 to 3 and Comparative Examples 1 to 4 A composition was obtained.

  Next, using each resin composition, a test piece for measuring Charpy impact strength and tensile elastic modulus was molded with an injection molding machine at a molding temperature of 200 ° C and a mold temperature of 40 ° C. Square plates were molded at a mold temperature of 40 ° C. The obtained test piece was used to evaluate the resin physical properties, and the square plate was used to evaluate the appearance characteristics of the molded body. Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 5, respectively.

  From the comparison between Example 1 and Comparative Example 4, when the content of the ethylene-derived structural unit of the component (A) exceeds 1.3% by mass, the grain gloss after the heat history increases, that is, the heat-resistant grain gloss deteriorates. I understand.

  From the comparison between Example 1 or 3 and Comparative Example 1, it can also be seen that when the melt flow rate of the component (B) exceeds 30 g / 10 minutes, the heat-resistant grain gloss is extremely deteriorated.

  From the comparison between Example 3 and Comparative Example 2, the propylene-ethylene random copolymer as the component (A) having Mw / Mn in the range of 1.8 to 3.5 was obtained with the same content of ethylene-derived structural unit. It can also be seen that the heat-resistant texture is deteriorated by changing to a propylene-ethylene random copolymer containing Mw / Mn of 3.5 or more.

  It can be seen from the comparison between Examples 1 to 3 and Comparative Example 3 that the balance between impact properties and rigidity is optimized by using the optimum amount of glass fiber.

  The propylene-based resin composition of the present invention can be suitably used as a molding material with a grain pattern in various fields such as automobile interior and exterior parts such as instrument panels and console boxes.

Claims (9)

Including the following (A) to (E), when the total content of (A) to (C) is 100 parts by mass, the content of (A) is 45 to 85 parts by mass, the content of (B) Is 5 to 25 parts by mass, (C) is 10 to 30 parts by mass, (D) is 0.01 to 1.0 parts by mass, and (E) is 0.1 to 3 parts by mass. Part of a propylene-based resin composition.
(A) Based on ASTM D1238, the melt flow rate measured under the conditions of a test load of 2.16 kg and a test temperature of 230 ° C. is 5 to 100 g / 10 minutes, and the content ratio of the structural units derived from ethylene to all structural units is From propylene-ethylene random copolymer or propylene homopolymer (B) ethylene having a Mw / Mn of 1.8 to 3.5 not exceeding 1.3 mass% and an α-olefin having 3 to 10 carbon atoms It is a copolymer with one or more selected α-olefins, and has a melt flow rate of 0.1 to 30 g / 10 measured under the conditions of a test load of 2.16 kg and a test temperature of 190 ° C. in accordance with ASTM D1238. Minute, ethylene-α-olefin copolymer (C) fibrous filler (D) lubricant (E) modified polypropylene having an average fiber length of 0.1 to 2 mm   (A) The propylene-ethylene random copolymer or the propylene homopolymer is a propylene-ethylene random copolymer, and the content ratio of structural units derived from ethylene to all structural units is 0.1% by mass or more, 1 The propylene-based resin composition according to claim 1, which does not exceed .3% by mass.   The propylene-based resin composition according to claim 1 or 2, wherein in the ethylene-α-olefin copolymer, the content ratio of the structural unit derived from α-olefin to the total structural unit of the copolymer is 5 to 60 mol%. object.   (C) A fibrous filler is a glass fiber filler, The propylene-type resin composition in any one of Claims 1-3.   (B) The structural unit derived from α-olefin constituting the ethylene-α-olefin copolymer is at least one selected from structural units derived from propylene, 1-butene, 1-hexene and 1-octene. Item 5. The propylene-based resin composition according to any one of Items 1 to 4.   (D) A lubricant is erucic acid amide, The propylene-type resin composition in any one of Claims 1-5.   (E) The modified polypropylene is maleic anhydride-modified polypropylene, The propylene-based resin composition according to any one of claims 1 to 6.   The molded object formed from the propylene-type resin composition in any one of Claims 1-7.   An automotive interior / exterior part formed from the propylene-based resin composition according to claim 1.