JP2006056971A - Manufacturing process of propylenic resin composition, propylenic resin composition and injection-molded molding composed of it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process of a propylenic resin composition having an excellent balance among the appearance, rigidity and impact resistance of the molding and an excellent balance between the impact resistance and heat resistance of the molding, a propylenic resin composition obtained from it and its injection-molded molding. <P>SOLUTION: The manufacturing process of the propylenic resin composition comprises the first step to obtain a resin composition (MB) by melt-molding 25-69.5 wt.% of (A) a propylene polymer, 30-70 wt.% of (B) a fibrous inorganic filler and 0.5-5 wt.% of (C) a modified olefin polymer and the second step to obtain the resin composition by adding (A) the propylene polymer, (D) a non-fibrous inorganic filler and (E) an olefinic elastomer and/or an elastomer containing a vinyl aromatic compound to the resin composition (MB) obtained in the first step and by melt-kneading the mixture. The propylenic resin composition thus obtained and its injection-molded molding are presented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a propylene-based resin composition, a propylene-based resin composition obtained by the production method, and an injection-molded body comprising the same. More specifically, a method for producing a propylene-based resin composition having excellent appearance of a molded article, a balance between rigidity and impact resistance, and an excellent balance between impact resistance and heat resistance, and a propylene-based resin obtained by the production method The present invention relates to a composition and an injection-molded body comprising the same.

Conventionally, propylene-based resins have been used as materials for automobiles because they are materials having excellent rigidity and impact resistance.
For example, Japanese Patent Application Laid-Open No. 61-69848 discloses a molded article that is suitable for the fields of automobiles, electricity, etc., has a high impact strength and heat resistance rigidity, a good surface appearance, and has small warpage and deformation. As the polypropylene resin composition to be given, a polypropylene resin composition containing a polypropylene resin, a fibrous filler, and talc is described, and it is described that a modified polyolefin or an elastomer may be blended. As a method for producing the composition, it is described that it can be obtained by sufficiently uniformly kneading by a combined method of dry mixing and melt mixing, a multistage melt mixing method, a simple melt mixing method, or the like.

  Japanese Patent Application Laid-Open No. 5-279526 discloses weight reduction while maintaining characteristics such as rigidity, heat resistance, and linear expansion coefficient of filler-filled polyolefin, and is suitably used as a molding material for automobile interior parts. A polyolefin resin composition comprising a polypropylene resin, a fibrous filler, and talc, and a polyolefin resin composition obtained by further adding an elastomer to the resin composition. As a method for producing the resin composition, a twin-screw extruder is used, and a polypropylene resin and talc are quantitatively supplied to a hopper, and after the polypropylene resin and talc are melt-kneaded, a fiber is formed in the downstream portion of the twin-screw extruder. A method is described in which a fixed amount of filler is supplied and kneaded again.

  Japanese Patent Application Laid-Open No. 10-36586 discloses a polypropylene resin composition that is excellent in rigidity and impact resistance, has a good surface appearance, dimensional accuracy, and moldability, and is suitably used for automobile interior and exterior materials. A polypropylene resin composition comprising a polypropylene resin, an ethylene / α-olefin copolymer, talc, and a fibrous inorganic filler is described, and as a method for producing the resin composition, A polypropylene resin, ethylene / α-olefin copolymer, and talc are quantitatively supplied to the hopper. After the polypropylene resin, ethylene / α-olefin copolymer, and talc are melt-kneaded, fibers are fed to the downstream of the twin screw extruder. A method is described in which a fixed amount of fibrous inorganic filler is supplied and kneaded again.

  Further, in JP-A-5-98087, as a polyolefin composition having excellent mechanical properties and heat resistance, a polyolefin, a modified polyolefin obtained by graft polymerization of a glycidyl compound onto the polyolefin, and a basic magnesium sulfate whisker are disclosed. The polyolefin composition to be contained is described, and it is also described that a rubber component such as an olefin-based elastomer can be added. As a method for producing the polyolefin composition, the components are mixed using a kneader. It describes that kneading is carried out in a heated and melted state.

Japanese Patent Laid-Open No. 61-69848 JP-A-5-279526 JP-A-10-36586 Japanese Patent Laid-Open No. 5-98087

However, even in the propylene-based resin compositions described in the above publications and the like, further improvements have been required for the molded appearance, the balance between rigidity and impact resistance, and the balance between impact resistance and heat resistance. .
In such a situation, an object of the present invention is to provide a method for producing a propylene-based resin composition having excellent appearance of a molded article, a balance between rigidity and impact resistance, and an excellent balance between impact resistance and heat resistance, and the production method. Is to provide a propylene-based resin composition obtained by the above, and an injection-molded body comprising the same.

As a result of intensive studies, the present inventors have found that the present invention can solve the above problems, and have completed this.
That is, the present invention
The weight ratio of the propylene polymer (A) is 25 to 69.5 wt%, the weight ratio of the fibrous inorganic filler (B) is 30 to 70 wt%, and the weight ratio of the modified olefin polymer (C) is 0. 0.5 to 5% by weight (provided that the total of the respective weight ratios of the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C) is 100% by weight) First step of obtaining a resin composition (MB) by melting and kneading the coalescence (A), the fibrous inorganic filler (B), and the modified olefin polymer (C), and the resin composition obtained in the first step A propylene polymer (A), a non-fibrous inorganic filler (D), an olefin-based elastomer and / or a vinyl aromatic compound-containing elastomer (E) are further added to (MB) and melt-kneaded to obtain a resin composition. Professional consisting of the second step Method for producing a polyalkylene-based resin composition, the propylene-based resin composition obtained by the production process, and is intended according to the injection-molded article comprising the same.

  According to the production method of the present invention, a propylene-based resin composition having an excellent appearance of a molded body, a balance between rigidity and impact resistance, and an excellent balance between impact resistance and heat resistance, and an injection molded body comprising the same Can be obtained.

Hereinafter, the present invention will be described in detail.
The propylene polymer (A) used in the present invention is a propylene-ethylene block copolymer (A-1) or a propylene homopolymer (A-2).
The propylene polymer (A) used in the first step is preferably a propylene homopolymer. The propylene polymer (A) used in the second step is preferably a propylene-ethylene block copolymer.

The propylene-ethylene block copolymer (A-1) is a copolymer having a propylene homopolymer portion as a first segment and a propylene-ethylene random copolymer portion as a second segment.
In the propylene-ethylene block copolymer used in the present invention, the weight ratio of the propylene homopolymer portion which is the first segment and the propylene-ethylene random copolymer portion which is the second segment is 95 for the first segment. -60% by weight and the second segment is 5-40% by weight. Preferably, the first segment is 90 to 65% by weight and the second segment is 10 to 35% by weight. (However, the total weight of the propylene-ethylene block copolymer (A-1) is 100% by weight.)

  Q value (Mw / Mn) which is the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) representing the molecular weight distribution of the first segment (propylene homopolymer part) in the propylene-ethylene block copolymer (A-1). ) Is usually 3 to 5, preferably 3.5 to 4.5, from the viewpoint of fluidity and the balance between rigidity and impact resistance.

  From the viewpoint of rigidity and heat resistance, the isotactic pentad fraction of the first segment in the propylene-ethylene block copolymer (A-1) is usually 0.97 or more, more preferably 0.98 or more. It is.

  The ethylene content ((C2 ′) EP) of the second segment in the propylene-ethylene block copolymer (A-1) is usually 25 to 60% by weight from the viewpoint of impact resistance, and more preferably 30 to 30%. 55% by weight. (However, the total weight of the second segment is 100% by weight.)

  In addition, the intrinsic viscosity ([η] EP) of the second segment is usually 1 to 9 dl / g, preferably 2 to 9 dl / g, from the viewpoint of the balance between rigidity and impact property, the occurrence of bulges and the surface quality. g, More preferably, it is 2-7.

  The MFR at 230 ° C. of the propylene-ethylene block copolymer (A-1) is usually 0.3 g / 10 minutes or more, preferably 10 g / 10 minutes or more.

As a manufacturing method of a propylene-ethylene block copolymer (A-1), the propylene homopolymer part which is the 1st segment is manufactured at the 1st process, and the propylene-ethylene random copolymer part which is the 2nd segment is prepared. The method of manufacturing at a 2nd process is mentioned.
And the method of manufacturing with a well-known polymerization method using a well-known polymerization catalyst is mentioned. Examples of the known polymerization catalyst include a Ziegler catalyst and a metallocene catalyst, and examples of the known polymerization method include a slurry polymerization method, a bulk polymerization method, and a gas phase polymerization method.

  The propylene homopolymer (A-2) used in the present invention is the same propylene as the propylene homopolymer which is the first segment of the propylene-ethylene block copolymer (A-1) used in the present invention. A homopolymer can be used.

  The MFR at 230 ° C. of the propylene homocopolymer (A-2) is usually 0.3 g / 10 min or more, preferably 0.5 g / 10 min or more. More preferably, it is 10 g / 10 minutes or more.

  From the viewpoint of melt-kneading the fibrous inorganic filler (B) without breaking, the shape of the propylene polymer (A) used in the first step of the production method of the present invention is preferably a pellet or powder. More preferably, it is powdery.

  The fibrous inorganic filler (B) used in the present invention is a fibrous inorganic filler having an average fiber length of 5 μm or more and an aspect ratio of 10 or more.

  Examples of the fibrous inorganic filler (B) include fibrous magnesium oxysulfate, potassium titanate fiber, magnesium hydroxide fiber, aluminum borate fiber, calcium silicate fiber, calcium carbonate fiber, carbon fiber, glass fiber, and metal. Examples thereof include fibers, and preferred are fibrous magnesium oxysulfate and calcium silicate fiber, and more preferred are fibrous magnesium oxysulfate.

The fibrous inorganic filler (B) preferably has an average fiber diameter of 0.2 to 1.5 μm, an average fiber length of 5 to 20 μm, and an aspect ratio of 10 to 30.
From the viewpoint of enhancing the effect of improving the rigidity and improving the appearance of the molded body, more preferably, the average fiber diameter is 0.3 to 1.0 μm, the average fiber length is 7 to 15 μm, and the aspect ratio Is 12-25.

  The fibrous inorganic filler (B) may be used without any treatment, and is usually used for improving the interfacial adhesion with the polypropylene resin and improving the dispersibility with respect to the polypropylene resin. The surface may be treated with an agent or a higher fatty acid metal salt. Examples of the higher fatty acid metal salt include calcium stearate, magnesium stearate, zinc stearate and the like.

  Examples of the form of the fibrous inorganic filler (B) include powder, flakes, and granules, and any form may be used. Preferably, it is granular from the viewpoint of easy handling.

The modified olefin polymer (C) used in the present invention is an olefin resin modified with an unsaturated carboxylic acid compound and / or a derivative of an unsaturated carboxylic acid compound.
Olefin resin is a homopolymer or copolymer of olefins, and examples of olefins include α-olefins and cyclic olefins. Examples of the α-olefin include ethylene, propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octene-1, decene-1, dodecene-1, and tetradecene. -1, hexadecene-1, octadecene-1, eicosene-1, and the like. Examples of the cyclic olefin include cyclic olefins described in JP-A-2-115248.

  The olefin resin is preferably a homopolymer or copolymer of olefin selected from ethylene, propylene, butene-1, and hexene-1, more preferably a propylene homopolymer, a propylene-ethylene block copolymer, and propylene. -An ethylene random copolymer or a mixture thereof, more preferably a propylene homopolymer.

  The molecular weight of the olefin resin is generally 0.01 to 400 g / 10 minutes, preferably 0.1 to 200 g, expressed in terms of a melt flow rate (MFR) measured under conditions of a temperature of 230 ° C. and a load of 21.2 N. / 10 minutes.

  The modified olefin polymer (C) used in the present invention is obtained by graft-modifying the above olefin resin with an unsaturated carboxylic acid compound and / or a derivative of an unsaturated carboxylic acid compound.

  Examples of the unsaturated carboxylic acid compound include unsaturated monocarboxylic acid and unsaturated dicarboxylic acid. Examples of the unsaturated monocarboxylic acid include acrylic acid and methacrylic acid. Examples of the unsaturated dicarboxylic acid include Examples include maleic acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid.

  Examples of the derivatives of unsaturated carboxylic acid compounds include derivatives of unsaturated monocarboxylic acids or unsaturated dicarboxylic acids, such as halides, amides, imides, anhydrides and esters of unsaturated monocarboxylic acids or unsaturated dicarboxylic acids. Is mentioned. Specific examples of the derivatives include maleimide, maleic anhydride, methyl acrylate, methyl methacrylate, citraconic anhydride, monomethyl maleate, dimethyl maleate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and the like.

  The unsaturated carboxylic acid compound or the derivative of the unsaturated carboxylic acid compound is preferably an unsaturated dicarboxylic acid or a derivative thereof, and more preferably maleic acid or maleic anhydride.

Examples of the method for producing the modified olefin polymer (C) used in the present invention include known graft modification methods such as a solution method and a melt kneading method. As a specific example of the graft modification method, a method of graft-modifying a propylene polymer with maleic anhydride is shown in the following (1) or (2).
(1) A propylene polymer, maleic anhydride, and a radical generator used as necessary are put into an extruder, a twin-screw kneader or the like, heated to a temperature of about 170 to 300 ° C. and melted. A melt-kneading method for obtaining a modified propylene polymer by melt-kneading.
(2) A propylene polymer, maleic anhydride, and a radical generator used as necessary are dissolved in an organic solvent such as xylene, and modified while stirring at a temperature of 90 to 200 ° C. for 0.1 to 100 hours. Solution method to obtain a propylene polymer.

Examples of the radical generator used in the above modification method include peroxides and diazo compounds.
Examples of peroxides include benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tertiary butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, and tertiary butyl peroxypivalate. 2,5-dimethyl-2,5-ditertiary butyl peroxyhexyne and the like.
Examples of the diazo compound include azobisisobutyronitrile.

The addition amount of the radical generator is usually 0.01 to 1 part by weight with respect to 100 parts by weight of the olefin resin used for modification. A phenolic antioxidant may be added at the time of graft modification.
Moreover, the addition amount of maleic anhydride is 0.2-20 weight part normally with respect to 100 weight part of olefin resins used for modification | denaturation.
The graft ratio of the modified polypropylene obtained by graft modification with maleic anhydride is usually 0.01 to 10% by weight, and the melt flow rate (MFR, JISK7210, load 21N, 230 ° C.) is usually 0.1. ~ 500.

  Examples of the non-fibrous inorganic filler (D) used in the present invention include talc, mica, calcium carbonate, barium sulfate, magnesium carbonate, clay, alumina, silica, calcium sulfate, silica sand, carbon black, titanium oxide, Examples thereof include magnesium hydroxide, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium hydroxide, calcium sulfite, sodium sulfate, bentonite, and graphite. From the viewpoint of obtaining good impact strength, good gloss of the molded article and good appearance, talc is preferable.

  The average particle diameter of the non-fibrous inorganic filler (D) is usually 10 μm or less, preferably 5 μm or less. Here, the average particle diameter of the non-fibrous inorganic filler (D) is an integral distribution curve of the sieving method measured by suspending in a dispersion medium such as water or alcohol using a centrifugal sedimentation type particle size distribution measuring device. It means the 50% equivalent particle diameter D50 determined from the above.

  Further, the non-fibrous inorganic filler (D) may be used as it is, and is usually used for improving the interfacial adhesion with the polypropylene resin and improving the dispersibility with respect to the polypropylene resin. The surface may be treated with a silane coupling agent, a titanium coupling agent or a surfactant. Examples of the surfactant include higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid salts and the like.

The elastomer (E) used in the present invention is an olefin elastomer (E-1) and / or a vinyl aromatic compound-containing elastomer (E-2).
The olefin elastomer (E-1) is ethylene and an α-olefin having 4 to 20 carbon atoms, and examples of the α-olefin having 4 to 20 carbon atoms used in (E-1) include 1-butene. , Isobutene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like, and these may be used alone or in combination of two or more. 1-butene, 1-hexene and 1-octene are preferred.

The density of the olefin-based elastomer (E-1) is usually 0 from the viewpoint of enhancing the dispersibility of the propylene copolymer (A) and the impact strength of the resulting resin composition at room temperature or low temperature. a .85~0.885g / cm ^3, preferably 0.85~0.880g / cm ^3, more preferably 0.855~0.875g / cm ^3.

  The MFR at 190 ° C. of the olefin elastomer (E-1) is usually 0.1 to 30 g / 10 minutes, preferably 0.5 to 20 g / 10 minutes, from the viewpoint of impact strength.

As a manufacturing method of an olefin type elastomer (E-1), the manufacturing method by a well-known polymerization method is mentioned using a well-known polymerization catalyst. Known polymerization catalysts include, for example, a Ziegler-Natta catalyst system comprising a vanadium compound, an organoaluminum compound and a halogenated ester compound, or at least one cyclopentadienyl anion skeleton on a titanium atom, a zirconium atom or a hafnium atom. Examples thereof include a so-called metallocene catalyst system in which a metallocene compound coordinated with a group having an alumoxane or boron compound is combined.
Known polymerization methods include, for example, a method of copolymerizing ethylene and α-olefin in an inert organic solvent such as a hydrocarbon compound, and a method of copolymerizing in ethylene and α-olefin without using a solvent. Can be mentioned.

  Examples of the vinyl aromatic compound-containing elastomer (E-2) include, for example, a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block, and a double bond of the conjugated diene portion of the block copolymer. Is a block polymer in which the double bond of the conjugated diene moiety of the block copolymer is hydrogenated by 80% or more, more preferably 85% or more hydrogen. It is a block polymer that has been added.

  The molecular weight distribution of the vinyl aromatic compound-containing elastomer (E-2) is a molecular weight distribution obtained from a weight average molecular weight (Mw) and a number average molecular weight (Mn) measured by a GPC (gel permeation chromatography) method ( (Q value) is preferably 2.5 or less, and more preferably 2.3 or less.

The average content of the vinyl aromatic compound contained in the vinyl aromatic compound-containing elastomer (E-2) is preferably 10 to 20% by weight, more preferably 12 to 19% by weight.
The melt flow rate (MFR, JIS-K-6758, 230 ° C.) of the vinyl aromatic compound-containing elastomer (E-2) is preferably 1 to 15 g / 10 minutes, more preferably 2 to 13 g / 10 minutes. is there.

  Examples of the vinyl aromatic compound-containing elastomer (E-2) include styrene-ethylene-butene-styrene rubber (SEBS), styrene-ethylene-propylene-styrene rubber (SEPS), and styrene-butadiene rubber (SBR). , Block copolymers such as styrene-butadiene-styrene rubber (SBS) and styrene-isoprene-styrene rubber (SIS), or block copolymers obtained by hydrogenating these rubber components.

  A rubber obtained by reacting an olefin copolymer rubber such as ethylene-propylene-nonconjugated diene rubber (EPDM) with a vinyl aromatic compound such as styrene can also be suitably used. Further, at least two kinds of vinyl aromatic compound-containing elastomers may be used in combination.

  Examples of the method for producing the vinyl aromatic compound-containing elastomer (E-2) include a method in which a vinyl aromatic compound is bonded to an olefin copolymer rubber or a conjugated diene rubber by polymerization, reaction, or the like.

  In the method for producing a propylene-based resin composition of the present invention, the weight proportion of the propylene polymer (A) is 25 to 69.5 wt%, and the weight proportion of the fibrous inorganic filler (B) is 30 to 70 wt%. The weight ratio of the modified olefin polymer (C) is 0.5 to 5% by weight (however, the respective weights of the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C)) 1) to obtain a resin composition (MB) by melt-kneading the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C). In addition to the resin composition (MB) obtained in the step and the first step, the propylene polymer (A), the non-fibrous inorganic filler (D), the olefin elastomer and / or the vinyl aromatic compound-containing elastomer (E ) And melt Mixing to a manufacturing method of a second step of obtaining a resin composition.

  In the first step of the method for producing the propylene-based resin composition of the present invention, the respective weight ratios of the propylene polymer (A), the fibrous inorganic filler (B) and the modified olefin polymer (C) to be melt-kneaded are , (A) is 25-69.5% by weight, (B) is 30-70% by weight, (C) is 0.5-5% by weight, preferably (A) is 38-59%. .2% by weight, (B) is 40-60% by weight, and (C) is 0.8-2% by weight.

  When (B) is less than 30% by weight, the effect of improving the rigidity may be reduced, and when it exceeds 70% by weight, (B) may be too much to be kneaded. When (C) is less than 0.5% by weight, the effect of improving heat resistance may be reduced, and when it exceeds 5% by weight, impact resistance and fluidity may be reduced.

Examples of a method for melt-kneading the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C) include a method of mixing and kneading each component.
Examples of the apparatus used for kneading include a single screw extruder, a twin screw extruder, a Banbury mixer, a hot roll, and the like, and a single screw extruder and a twin screw extruder are preferable.
The temperature of the resin when melt-kneading is usually 170 to 250 ° C., and the time of melt-kneading is usually 30 seconds to 10 minutes.

  As a method of melt-kneading the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C), preferably the fibrous inorganic filler (B) is not broken. In this method, a powdery propylene polymer (A) is used as the propylene polymer (A). As a more preferable method, the lubricant (F) is added in an amount of 0.3 to 3 parts by weight based on 100 parts by weight of the total weight of the propylene polymer (A) and the fibrous inorganic filler (B) modified olefin polymer (C). It is a method of adding and melting and kneading using a screw having L / D of 10 to 25.

Examples of the lubricant (F) include silane compounds, polyolefin waxes, fatty acid amides, and the like, preferably fatty acid amides, and more preferably fatty acid amides having 6 to 22 carbon atoms.
Examples of the fatty acid amide include lauric acid amide, stearic acid amide, oleic acid amide, behenic acid amide, erucic acid amide, and the like, and preferably erucic acid amide.

  In the second step of the method for producing a propylene-based resin composition of the present invention, a propylene polymer (A) and a non-fibrous inorganic filler (D) are further added to the resin composition (MB) obtained in the first step. In this process, an olefin elastomer and / or a vinyl aromatic compound-containing elastomer (E) is added and melt kneaded to obtain a resin composition.

  Examples of the apparatus used for melt kneading in the second step include a single screw extruder, a twin screw extruder, a Banbury mixer, and a hot roll. The temperature of the resin in the second step of melt kneading is usually 170 to 250 ° C., and the time of melt kneading is usually 1 to 20 minutes. Moreover, mixing of each component may be performed simultaneously and may be performed by dividing | segmenting. Further, a small amount of fibrous inorganic filler (B) may be added in the second step so as not to affect the performance.

  The first step and the second step of the production method of the propylene-based resin composition of the present invention may be performed continuously with one extruder, and the resin composition is once produced as a pellet in the first step, and then You may perform a 2nd process using the pellet obtained at the 1st process.

In the case where the resin composition is once manufactured as a pellet in the first step and the obtained pellet is used in the second step, the resin composition (MB) which is the pellet obtained in the first step and propylene are used in the second step. The polymer (A), the non-fibrous inorganic filler (D) and the elastomer (E) may be melt-kneaded all at once, or may be divided and melt-kneaded.
Examples of the method of dividing and melt-kneading include the following methods (1) to (4).
(1) After melt-kneading the propylene polymer (A), the non-fibrous inorganic filler (D) and the elastomer (E), a resin composition (MB) which is a pellet obtained in the first step is added, Melting and kneading method.
(2) After melt-kneading the resin composition (MB), the propylene polymer (A) and the non-fibrous inorganic filler (D) which are pellets obtained in the first step, the elastomer (E) is added, Melting and kneading method.
(3) After melt-kneading the resin composition (MB), the propylene polymer (A) and the elastomer (E) which are pellets obtained in the first step, the non-fibrous inorganic filler (D) is added, Melting and kneading method.
(4) The resin composition (MB) and the non-fibrous inorganic filling that are pellets obtained in the first step by melt-kneading the propylene polymer (A) with a high concentration of the elastomer (E) in advance to obtain a master batch. A method of adding the material (D) and melt-kneading.

The resin composition (MB), the propylene polymer (A), the non-fibrous inorganic filler (D) and the elastomer (E) contained in the polypropylene resin composition of the present invention are rigid or impact strength. From the viewpoint of enhancing the improvement effect, the content of the resin composition (MB) obtained in the first step is usually 5 to 30% by weight of the propylene polymer (A) further added in the second step. The content is 20 to 85% by weight, the content of the non-fibrous inorganic filler (D) is 5 to 20% by weight, and the content of the elastomer (E) is 5 to 30% by weight. (However, the total amount of the propylene resin composition is 100% by weight.)
Preferably, the content of the resin composition (MB) is 10 to 20% by weight, the content of the propylene polymer (A) further added in the second step is 53 to 75% by weight, and the non-fibrous inorganic The filler (D) content is 5 to 12% by weight, and the elastomer (E) content is 10 to 15% by weight.
Further, the content of the fibrous inorganic filler (B) contained in the resin composition (MB) is preferably 5 to 12% by weight. (However, the total amount of the propylene resin composition is 100% by weight.)

The propylene-based resin composition of the present invention is a propylene-based resin composition obtained by using the above-described method for producing a propylene-based resin composition.
In the polypropylene resin composition of the present invention, if necessary, an antioxidant, an ultraviolet absorber, a pigment, an antistatic agent, a copper damage inhibitor, a flame retardant, a lubricant, a neutralizing agent, a foaming agent, a plasticizer, You may mix | blend additives, such as a nucleating agent, an anti-bubble agent, and a crosslinking agent.

The injection-molded article of the present invention is obtained by molding the polypropylene resin composition of the present invention by a known injection molding method.
Examples of the use of the injection-molded article of the present invention include automotive parts, electrical / electronic product parts, building material parts, and the like, and preferably automotive parts.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these examples.
The measuring method of the physical property value in an Example and a comparative example was shown below.
(1) Melt flow rate (MFR, unit: g / 10 minutes)
The measurement was performed according to the method defined in JIS-K-6758. Unless otherwise specified, the measurement temperature was 230 ° C. and the load was 2.16 kg.

(2) Flexural modulus (unit: MPa)
The measurement was performed according to the method defined in JIS-K-7203. A test piece molded by injection molding was used. The thickness of the test piece was 6.4 mm, and the flexural modulus was evaluated under the conditions of a span length of 100 mm and a load speed of 30 mm / min. The measurement temperature was 23 ° C.

(3) Izod impact strength (unit: KJ / m ² )
The measurement was performed according to the method defined in JIS-K-7110. A test piece molded by injection molding was used. The thickness of the test piece was 3.2 mm, and the impact strength with a notch was evaluated. The measurement temperature was 23 ° C.

(4) Ethylene content (unit: wt%)
The ethylene content was determined by a calibration curve method using the absorbance of the characteristic absorption of methyl groups (—CH ₃ ) and methylene groups (—CH ₂ —) obtained by preparing press sheets and measuring infrared absorption spectra. .

(5) Intrinsic viscosity ([η], unit: dl / g)
Using a Ubbelohde viscometer, reduced viscosities were measured at three concentrations of 0.1, 0.2 and 0.5 g / dl. The intrinsic viscosity is calculated by the calculation method described in “Polymer Solution, Polymer Experiments 11” (published by Kyoritsu Shuppan Co., Ltd.), page 491. That is, the reduced viscosity is plotted against the concentration and the concentration is extrapolated to zero Obtained by extrapolation. Polypropylene was evaluated at a temperature of 135 ° C. using tetralin as a solvent.

(6) Molecular weight distribution (Q value)
It measured on the conditions shown below using the gel permeation chromatography (GPC).
GPC: Waters 150C type Column: Showa Denko Shodex 80 MA 2 Sample amount: 300 μl (polymer concentration 0.2 wt%)
Flow rate: 1 ml / min
Temperature: 135 ° C
Solvent: o-dichlorobenzene A standard curve of elution volume and molecular weight was prepared using standard polystyrene made by Toyo Soda. Using a calibration curve, the polystyrene-equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) of the sample were obtained, and the Q value, that is, the weight average molecular weight / number average molecular weight (Mw / Mn) was obtained as a measure of the molecular weight distribution. .

(7) Isotactic pentad fraction (unit:%)
The isotactic pentad fraction is determined as follows: Measurements were made according to the method published and described by Zambelli et al., Macromolecules, 6, 925 (1973). That is, an isotactic chain of pentad units in a polypropylene molecular chain measured using ¹³ C-NMR, in other words, a propylene monomer at the center of a chain in which five propylene monomer units are continuously meso-bonded The unit fraction was determined. However, the assignment of NMR absorption peaks was performed based on Macromolecules, 8, 687 (1975), which was published thereafter.
Specifically, the isotactic pentad fraction was measured as the area fraction of the mmmm peak in the total absorption peak in the methyl carbon region of the ¹³ C-NMR spectrum. By this method, NPL reference material CRM No. of British PHYSICAL LABORATORY It was 0.944 when the isotactic pentad fraction of M19-14 PolypropylenePP / MWD / 2 was measured.

(8) Propylene-ethylene block copolymer weight ratio of propylene-ethylene random copolymer portion to all block copolymers (X, wt%)
In the propylene-ethylene block copolymer, the weight ratio X (% by weight) of the propylene-ethylene random copolymer portion to the total block copolymer is the amount of heat of crystal melting of each of the propylene homopolymer portion and the total block copolymer. Was calculated from the following equation.
X = 1− (ΔHf) T / (ΔHf) P
(ΔHf) T: calorific value of heat of the entire block copolymer (cal / g)
(ΔHf) P: heat of fusion of propylene homopolymer part (cal / g)

(9) Ethylene content of propylene-ethylene random copolymer portion in propylene-ethylene block copolymer (unit:% by weight)
The ethylene content of the propylene-ethylene random copolymer portion in the propylene-ethylene block copolymer was measured by the ethylene content (% by weight) in all block copolymers by infrared absorption spectroscopy, and calculated from the following formula.
(C2 ') EP = (C2') T / X
(C2 ′) T: ethylene content (% by weight) in all block copolymers
(C2 ′) EP: ethylene content of propylene-ethylene random copolymer portion
(weight%)

(10) Intrinsic viscosity of propylene-ethylene random copolymer portion in propylene-ethylene block copolymer ([η] EP, unit: dl / g)
The intrinsic viscosity [η] EP of the propylene-ethylene random copolymer portion in the propylene-ethylene block copolymer is calculated from the following formula by measuring the intrinsic viscosity of each of the propylene homopolymer portion and the entire block copolymer: Calculated.
[Η] EP = [η] T / X− (1 / X−1) [η] P
[Η] P: Intrinsic viscosity of the propylene homopolymer part (dl / g)
[Η] T: Intrinsic viscosity of the entire block copolymer (dl / g)
In addition, the intrinsic viscosity [η] P of the propylene homopolymer portion which is the first segment of the propylene-ethylene block copolymer is from the inside of the polymerization tank after the production of the propylene homopolymer portion which is the first step. [Η] P was determined from the taken out propylene homopolymer.

(11) Evaluation of molding appearance The appearance (presence or absence) of the physical property evaluation test piece, which is an 80 mm × 240 mm × 3 mm flat plate obtained by an injection molding method described later, was visually observed.
The case where no defects were observed on the test piece for evaluating physical properties was marked with ◯, and the case where it was observed was marked with ×.

(12) Heat distortion temperature (deflection temperature under load, HDT, unit: ° C)
The measurement was performed according to the method defined in JIS-K-7207. Fiber stress was measured at 0.45 MPa.

The sample used for Examples 1-3 and Comparative Examples 1-3 was shown below.
(Aa) Propylene homopolymer The molecular weight distribution (Q value) is 4.1, the intrinsic viscosity ([η] P) is 0.80 dl / g, and the isotactic pentad fraction is 0.99. A powdery propylene homopolymer (A) having an MFR (230 ° C.) of 300 g / 10 min was used.

(Ab) Propylene-ethylene block copolymer (1) Propylene-ethylene block copolymer (BC-1)
AZ564 manufactured by Sumitomo Chemical Co., Ltd. was used. The MFR (230 ° C.) of AZ564 was 30 g / 10 minutes.
The molecular weight distribution (Q value) of the propylene homopolymer portion (first segment) is 4.0, the intrinsic viscosity ([η] P) is 1.05 dl / g, and the isotactic pentad fraction is 0. The intrinsic viscosity ([η] EP) of the propylene-ethylene random copolymer portion (second segment) is 4.0 dl / g, and the weight relative to the propylene-ethylene block copolymer (BC-1) The proportion was 16% by weight and the ethylene content was 45% by weight.

(2) Propylene-ethylene block copolymer (BC-2)
AS171G manufactured by Sumitomo Chemical Co., Ltd. was used. The MFR (230 ° C.) of AS171G was 0.9 g / 10 min.
The molecular weight distribution (Q value) of the propylene homopolymer portion (first segment) is 4.0, the intrinsic viscosity ([η] P) is 2.3 dl / g, and the isotactic pentad fraction is 0. The intrinsic viscosity ([η] EP) of the propylene-ethylene random copolymer portion (second segment) is 4.5 dl / g, and the weight relative to the propylene-ethylene block copolymer (BC-2) The proportion was 15.6% by weight and the ethylene content was 37.5% by weight.

(B) Fibrous inorganic filler Moss Heidi A (fibrous magnesium oxysulfate) manufactured by Ube Materials Co., Ltd. was used as the fibrous inorganic filler. The average fiber diameter was 0.5 μm, the average fiber length was 10 μm, and the average aspect ratio was 20.

(C) Modified olefin polymer (1) Modified propylene polymer (C-1)
Polybond 3200 manufactured by Shiraishi Calcium Co. was used. A propylene homopolymer was modified with maleic anhydride and had an MFR of 200 g / 10 min and a maleic acid graft ratio of 0.3% by weight.

(2) Modified propylene polymer (C-2)
A propylene-ethylene block copolymer modified with maleic anhydride was used. The MFR was 70 g / 10 min and the maleic acid graft ratio was 0.8% by weight.

(D) Non-fibrous inorganic filler As the non-fibrous inorganic filler, talc (MWHST, Hayashi Kasei Co., Ltd.) was used. The average particle size was 2.7 μm.

(E) Elastomer The following E-1 to E-4 were used as the olefin elastomer and the vinyl aromatic compound-containing elastomer.
(1) E-1
Ethylene-1-butene copolymer manufactured by Sumitomo Chemical Co., Ltd .: Excellen FX CX5515 (density: 0.870 g / cm ³ , MFR (190 ° C.): 6 g / 10 min)
(2) E-2
Ethylene-1-octene copolymer rubber manufactured by DuPont Dow Elastomer Co., Ltd .: ENGAGE 8200 (density: 0.870 g / cm ³ , MFR (190 ° C.): 5 g / 10 min)
(3) E-3
Ethylene-1-octene copolymer rubber manufactured by DuPont Dow Elastomer Co., Ltd .: ENGAGE 8150 (density: 0.870 g / cm ³ , MFR (190 ° C.): 0.5 g / 10 min)
(4) E-4
Ethylene-1-octene copolymer rubber manufactured by DuPont Dow Elastomer Co., Ltd .: ENGAGE 8842 (density: 0.858 g / cm ³ , MFR (190 ° C.): 1 g / 10 min)

(F) Lubricant As a lubricant, erucic acid amide NewS manufactured by Nippon Seika Co., Ltd. was used.

Examples 1-3, Comparative Example 1
First step: Melt kneading of propylene polymer (A), fibrous inorganic filler (B) and modified olefin polymer (C) Propylene homopolymer (A), fibrous inorganic filler (B) and modified olefin weight The coalesced (C-1, C-2) and lubricant (F) were fed from a weigher so as to have the composition shown in Table 1, and kneaded using a twin-screw kneading extruder (4FCM manufactured by Kobe Steel). The screw had a full flight shape and L / D = 18.5. After melt-kneading with a biaxial kneader, it was then pelletized with a 120 mm single-screw extruder manufactured by Osaka Seiki Co., Ltd. to obtain MB-1 and MB-2. Moreover, MB-3 was obtained as Comparative Example 1 in which the modified olefin polymer (C) was not used.

(Polypropylene resin composition)
A polypropylene resin composition was produced by the following method. Propylene-ethylene block copolymer (BC-1, BC-2), ethylene-α-olefin copolymer rubber (E-1, E-2, E-3, E-4), obtained in the first step The resin (MB-1, MB-2) and the non-fibrous inorganic filler (D) having the composition shown in Table 2, were uniformly premixed with a Henschel mixer and a tumbler, and then a twin-screw kneading extruder (Tex44SS-31.5BW-2V type manufactured by Nippon Steel Co., Ltd.) was used to produce a polypropylene resin composition under an extrusion rate of 30 kg / hr, a screw rotation speed of 350 rpm, and vent suction. The MFR of the obtained polypropylene resin composition was measured. The results are shown in Table 3.

(Injection molding)
Test pieces for evaluating physical properties were produced under the following injection molding conditions. The polypropylene resin composition obtained above was dried at 120 ° C. for 2 hours with a hot air drier, then using a Toshiba Machine IS150E-V type injection molding machine, a molding temperature of 180 ° C., a mold cooling temperature of 50 ° C., injection Injection molding was performed with a time of 15 sec and a cooling time of 30 sec. The obtained injection molded product was measured for flexural modulus and Izod impact strength. The results are shown in Table 3.

Comparative Examples 2 and 3
Comparative Examples 2 and 3 were carried out as manufacturing methods that did not use the first step.
A polypropylene resin composition was produced by the following method. Propylene-ethylene block copolymers (BC-1, BC-2), ethylene-α-olefin copolymer rubber (E-1), and non-fibrous inorganic filler (D) have the compositions shown in Table 4. Thus, the mixture was fed from a weigher and kneaded using a biaxial kneading extruder (SCM90 manufactured by Nippon Placon Co., Ltd.). A polypropylene resin composition was produced with a screw L / D = 32, an extrusion rate of 200 kg / hr, a screw rotation speed of 230 rpm, a screw temperature of 200 ° C., and vent suction.
Component B was fed from the downstream of the screw (location of L / D = 16) and kneaded. Table 5 shows the MFR and physical properties of the obtained polypropylene resin composition.

It can be seen that Examples 1, 2, and 3 that satisfy the requirements of the present invention have a higher heat distortion temperature and excellent heat resistance than Comparative Example 1 in which no modified olefin polymer is used.
Further, compared to Examples 2 and 3 in which Examples 1, 2 and 3 were not used in the first step of melt kneading (A), (B) and (C), rigidity, impact resistance, heat distortion temperature, It turns out that it is excellent in appearance.

Claims (9)

  The weight ratio of the propylene polymer (A) is 25 to 69.5 wt%, the weight ratio of the fibrous inorganic filler (B) is 30 to 70 wt%, and the weight ratio of the modified olefin polymer (C) is 0. 0.5 to 5% by weight (provided that the total of the respective weight ratios of the propylene polymer (A), the fibrous inorganic filler (B), and the modified olefin polymer (C) is 100% by weight) First step of obtaining a resin composition (MB) by melting and kneading the coalescence (A), the fibrous inorganic filler (B), and the modified olefin polymer (C), and the resin composition obtained in the first step A propylene polymer (A), a non-fibrous inorganic filler (D), an olefin-based elastomer and / or a vinyl aromatic compound-containing elastomer (E) are further added to (MB) and melt-kneaded to obtain a resin composition. Professional consisting of the second step Method for producing a polyalkylene resin composition.   It is a manufacturing method of the propylene-type resin composition of Claim 1, Comprising: Content of the resin composition (MB) obtained at the 1st process is 5 to 30 weight%, It is further added at the 2nd process. The propylene polymer (A) content is 20 to 85% by weight, the non-fibrous inorganic filler (D) content is 5 to 20% by weight, and the olefin elastomer and / or vinyl aromatic compound. The manufacturing method of the propylene-type resin composition whose content of containing elastomer (E) is 5 to 30 weight%. (However, the total amount of the propylene resin composition is 100% by weight.)   The manufacturing method of the propylene-type resin composition of Claim 1 or 2 which manufactures the resin composition (MB) obtained at the 1st process as a pellet, and uses this pellet at a 2nd process.   Claims using fibrous magnesium oxysulfate having an average fiber diameter of 0.2 to 1.5 μm, an average fiber length of 5 to 20 μm, and an aspect ratio of 10 to 30 as the fibrous inorganic filler (B) The manufacturing method of the propylene-type resin composition in any one of claim | item 1-3.   The method for producing a propylene-based resin composition according to any one of claims 1 to 4, wherein an acid-modified propylene polymer is used as the modified olefin polymer (C).   The method for producing a propylene-based resin composition according to any one of claims 1 to 5, wherein talc is used as the non-fibrous inorganic filler (D).   In the first step, 0.3 to 3 parts by weight of the lubricant (F) is added to 100 parts by weight of the total weight of the propylene polymer (A), the fibrous inorganic filler (B) and the modified olefin polymer (C). In addition, pellets of the resin composition (MB) are produced using a kneader having a ratio (L / D) of the length (L) to the diameter (D) of the screw of 15 to 25. A method for producing a propylene-based resin composition according to claim 1.   The propylene-type resin composition obtained by the manufacturing method of the propylene-type resin composition in any one of Claims 1-7.   An injection-molded article comprising the propylene-based resin composition according to claim 8.