JP2018024750A - Resin composition, and molded body obtained from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene-based resin composition capable of obtaining a molded body excellent in workability and balance among appearance, rigidity and impact resistance.SOLUTION: A resin composition contains a propylene-based polymer (A) having an MFR measured at 230°C and a test load of 2.16 kgf in a range of 0.01-100 g/10 min, a propylene-based wax (B) and an inorganic filler (C), where when the total of the contents of the propylene-based polymer (A) and the inorganic filler (C) is 100 pts.mass, the resin composition contains 1-70 pts.mass of the propylene-based polymer (A), 30-99 pts.mass of the inorganic filler (C) and 0.1-50 pts.mass of the propylene-based wax (B), and the propylene-based wax (B) satisfies the following (i) and (ii). (i) a number average molecular weight (Mn) in terms of polystyrene measured by GPC is in a range of 300-20,000. (ii) an acid value is in a range of 1-100 mgKOH/g.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition having a specific composition and a molded body obtained from the resin composition.

  Propylene-based resins such as polypropylene are excellent in mechanical properties and moldability. Therefore, propylene-based resins are used in various applications such as automobile parts and household appliance parts. Conventionally, it is known that the rigidity is improved by adding an inorganic filler such as talc, mica, and glass fiber to a propylene-based resin. Patent Document 1 describes that the dimensional stability of a molded body is increased by adding talc having a specific aspect ratio and an average particle diameter in a predetermined range to a propylene resin. Yes.

Japanese Patent Laid-Open No. 2006-84386

  Conventionally, the content of an inorganic filler such as talc in the propylene-based resin composition is at most about 20 to 30% by mass with respect to the total of the resin and the inorganic pigment. When the content ratio of the inorganic filler in the resin composition is increased, the rigidity of the resulting molded body is improved, but the impact strength tends to be reduced. In addition, appearance and workability may be deteriorated. Therefore, the composition having a relatively high content of the inorganic filler has a problem that it cannot be applied to applications that require rigidity, impact strength, and the like, such as automobile applications.

  The present invention has been made in view of the above problems. That is, the present invention provides a propylene-based resin composition capable of obtaining a molded article having excellent workability and a good balance of appearance, rigidity, and impact strength in spite of a relatively high content of the inorganic filler. The purpose is to provide.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above problem can be solved by using a resin composition having a specific composition, and the present invention has been completed.

That is, this invention relates to the following resin compositions and the molded object obtained from this.
[1] Propylene-based polymer (A) having a melt flow rate (MFR) measured in a range of 0.01 to 100 g / 10 min in accordance with JIS K7210 and measured at 230 ° C. under a test load of 2.16 kgf, and a propylene-based wax (B) and an inorganic filler (C), and when the total content of the propylene polymer (A) and the inorganic filler (C) is 100 parts by mass, the propylene 1 to 70 parts by mass of the polymer (A), 30 to 99 parts by mass of the inorganic filler (C), 0.1 to 50 parts by mass of the propylene wax (B), and the propylene wax (B) A resin composition satisfying the following (i) and (ii).
(I) The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 300 to 20000 (ii) The acid value is in the range of 1 to 100 mgKOH / g.

[2] The propylene-based wax (B) is at least selected from the group consisting of a propylene homopolymer and a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms. The resin composition according to [1], which is an unsaturated carboxylic acid derivative monomer modified product or air oxide of one polymer.
[3] The resin composition according to [1] or [2], wherein the propylene polymer (A) is a propylene / ethylene block copolymer.
[4] The resin composition according to [1] to [3], wherein the inorganic filler (C) is talc.
[5] A molded product obtained from the resin composition according to any one of [1] to [4].

  ADVANTAGE OF THE INVENTION According to this invention, the propylene resin composition which is excellent in workability and can obtain the molded object excellent in the balance of an external appearance, rigidity, and impact strength can be provided.

  Hereinafter, the resin composition of the present invention and the molded product obtained therefrom will be described in detail.

(Resin composition)
The resin composition of the present invention contains a propylene polymer (A), a propylene wax (B), and an inorganic filler (C). Here, the propylene polymer (A) is a polymer having a relatively high molecular weight that satisfies a specific MFR, and the propylene wax (B) is a polymer having a relatively low molecular weight.

  When the total content of the propylene polymer (A) and the inorganic filler (C) in the resin composition of the present invention is 100 parts by mass, the amount of the propylene polymer (A) is 1 to 70. It is a mass part, Preferably it is 20-65 mass parts, More preferably, it is 30-64 mass parts, More preferably, it is 50-62 mass parts. On the other hand, the amount of the inorganic filler (C) is 30 to 99 parts by mass, preferably 35 to 80 parts by mass, more preferably 36 to 70 parts by mass, and further preferably 38 to 50 parts by mass. is there.

Further, when the total content of the propylene polymer (A) and the inorganic filler (C) in the resin composition is 100 parts by mass, the amount of the propylene wax (B) is 0.1 to 50 masses. Part, preferably 0.1 to 20 parts by weight, more preferably 0.2 to 9 parts by weight, still more preferably 0.3 to 7 parts by weight, and particularly preferably 0.4 to 5 parts by weight. Parts by mass, and most preferably 1 to 3 parts by mass. When the amount of the propylene-based wax (B) is in this range, the workability of the resin composition is excellent, and the balance of appearance, rigidity, and impact strength of the molded product obtained from the resin composition is increased.
Hereinafter, each component and each requirement will be described.

1. Propylene polymer (A)
In the resin composition of the present invention, the propylene-based polymer (A) may contain only one type or two or more types.

  The melt flow rate (MFR) measured at 230 ° C. under a test load of 2.16 kgf based on JIS K7210 of the propylene polymer (A) is 0.01 to 100 g / 10 minutes, preferably 0.1 to 50 g. / 10 minutes. When the MFR of the propylene-based polymer (A) is in the above range, it is easy to injection mold the resin composition, and further, a molded body having an excellent balance between rigidity and impact strength can be obtained.

  The propylene polymer (A) may be a propylene homopolymer (polypropylene) or a copolymer of propylene and an α-olefin. The ethylene / α-olefin copolymer may be a random copolymer or a block copolymer. Examples of α-olefins copolymerized with propylene include ethylene and α-olefins having 4 to 12 carbon atoms. When the propylene polymer is a copolymer of propylene and ethylene, the amount of the structural unit derived from propylene is preferably 60 to 99.5 mol%. The amount of the structural unit derived from propylene is more preferably 80 to 99 mol%, further preferably 90 to 98.5 mol%, and particularly preferably 95 to 98 mol%. Here, the sum total of the quantity of the structural unit derived from propylene and the quantity of the structural unit derived from ethylene is 100 mol%. When the resin composition contains an ethylene / propylene copolymer having a large amount of propylene-derived structural unit, the resulting molded article has a good appearance and a good balance between mechanical strength and heat resistance.

  When the propylene polymer is a copolymer of propylene and an α-olefin having 4 to 12 carbon atoms, examples of the α-olefin having 4 to 12 carbon atoms include, for example, 1-butene and 1-pentene. Linear or branched α such as 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, etc. -Olefin is included. Among these, 1-butene is particularly preferable. Further, the propylene / α-olefin copolymer may contain an olefin having 4 to 12 carbon atoms. For example, a small amount of structural units derived from ethylene or the like (for example, all structural units of the propylene-based copolymer). 10 mol% or less). On the other hand, it is also preferable that the structural unit derived from ethylene is not included from the viewpoint of improving the balance between the heat resistance and the mechanical strength of the molded body obtained from the resin composition. The ethylene / α-olefin copolymer may contain only one kind of α-olefin, or may contain two or more kinds of α-olefins.

  The propylene polymer (A) is particularly preferably a propylene / ethylene block copolymer, particularly preferably a polymer having a propylene homopolymer block and an ethylene / propylene random copolymer block. The propylene homopolymer block is a component insoluble in n-decane, and the ethylene / propylene random copolymer block is a component soluble in n-decane. Therefore, in the propylene / ethylene block copolymer, these can be clearly distinguished or separated.

  Here, the propylene / ethylene block copolymer is (a) propylene homopolymer component having an intrinsic viscosity [η] measured at 135 ° C. in a decalin solution of 0.2 to 2.0 dl / g, 80 to 97 mass. And (b) 3 to 20% by mass of an ethylene / propylene random copolymer component having an intrinsic viscosity [η] measured at 135 ° C. in a decalin solution of 2.5 to 9.0 dl / g (provided that (a) A component obtained by copolymerizing the component and the total of component (b) is 100% by mass). Hereinafter, the intrinsic viscosity [η] in the present specification means a value measured in a decalin solution at 135 ° C. unless otherwise specified.

  The polymerization ratio of the (a) propylene homopolymer component and the (b) ethylene / propylene random copolymer component is (a) component: (b) component is 80 to 95% by mass: 5 to 20% by mass. It is preferable that it is 82-92 mass%: 8-18 mass%. Here, the sum total of (a) component and (b) component is 100 mass%.

  Such a propylene / ethylene block copolymer can be appropriately produced by a known method.

  The propylene polymer (A) may be graft-modified with a polar compound containing a double bond and having a polar group. Examples of the polar compound include an unsaturated carboxylic acid or a derivative thereof for graft-modifying a propylene-based wax described later.

  The propylene polymer (A) preferably has a melting point (Tm) measured by a differential scanning calorimeter (DSC) of 250 ° C. or lower or is not observed. When the melting point is observed, the upper limit of the melting point is more preferably 230 ° C., further preferably 200 ° C., and particularly preferably 170 ° C. The lower limit of the melting point is preferably 50 ° C., more preferably 70 ° C., still more preferably 90 ° C., particularly preferably 130 ° C., and most preferably 150 ° C. When the melting point is in the range between the upper limit and the lower limit, it is difficult to generate smoke or odor when the resin composition is prepared or the molded body is produced, and the influence on the working environment is reduced. In addition, the obtained molded product is hardly sticky, and a molded product having an excellent balance of heat resistance, mechanical strength, impact strength, and impact absorbability is easily obtained.

  The propylene polymer (A) preferably has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) in the range of −140 ° C. to 50 ° C., more preferably −120 ° C. It exists in the range of -40 degreeC, More preferably, it exists in the range of -50 degreeC--10 degreeC. When the glass transition temperature is within the above range, the long-term stability of the resin composition and the balance between the heat resistance, impact resistance and mechanical strength of the molded product tend to be excellent.

Furthermore, it is preferable that the bending elastic modulus measured based on JISK7171: 94 of a propylene-type polymer (A) is 1-10000 Mpa.
Here, when the molded body obtained from the resin composition is required to have scratch resistance, mechanical strength or the like, the flexural modulus is preferably 500 to 7000 MPa, more preferably 700 to 5000 MPa, and particularly preferably 900. It is -3000MPa, More preferably, it is 1000-2000MPa. When the flexural modulus is in the above range, not only the processability of the resin composition is excellent, but also the balance of scratch resistance, heat resistance, and mechanical strength of the molded article is excellent.

  On the other hand, when flexibility etc. are requested | required of the molded object obtained from a resin composition, the said bending elastic modulus becomes like this. Preferably it is less than 300 MPa, More preferably, it is less than 100 MPa, More preferably, it is less than 50 MPa. When the flexural modulus is in the above range, not only the flexibility of the obtained molded article is excellent, but also the impact absorption, light weight, vibration proofing, vibration damping and sound damping are excellent. Furthermore, design properties such as mold transferability and embossing transferability and surface grip properties of the molded article are also improved.

  The number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) of the propylene polymer (A) is more than 20000, and the upper limit is preferably 300,000. The upper limit is more preferably 200,000, still more preferably 100,000, and particularly preferably 90000. The weight average molecular weight (Mw) in terms of polystyrene measured by GPC of the propylene polymer (A) is preferably 40000 to 3000000, more preferably 40000 to 2000000, still more preferably 40000 to 1000000, particularly preferably. 40,000 to 900,000. When it is in the above range, the resin composition can be easily injection-molded, and a molded product having an excellent balance between rigidity and impact strength can be easily obtained.

2. Propylene wax (B)
The propylene-based wax (B) satisfies the following requirements (i) and (ii). Furthermore, it is preferable that at least one of requirements (iii) and (iv) is satisfied.

(I) The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 300 to 20000 (ii) The acid value is in the range of 1 to 100 mgKOH / g (iii) JISK (Iv) The ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) measured by gel permeation chromatography (GPC) is 7.0 or less.

  The number average molecular weight (requirement (i)) of the propylene-based wax (B) is preferably 500 to 18000, more preferably 1000 to 12000, further preferably 1500 to 12000, and particularly preferably 3700 to 12000. When the number average molecular weight is within the above range, the dispersibility of the inorganic filler (C) in the resin composition is increased, the appearance of the resulting molded article is improved, and the heat resistance and mechanical strength are increased. Moreover, there exists a tendency for the workability and kneadability of a resin composition to become favorable.

  On the other hand, the acid value (requirement (ii)) of the propylene-based wax (B) is usually preferably 20 to 90 mgKOH / g, and more preferably 30 to 87 mgKOH / g. When the acid value is in the above range, as described above, the molded article obtained from the resin composition of the present invention has both rigidity and impact resistance. The acid value refers to the number of mg of potassium hydroxide required for neutralization per 1 g of sample. The acid value of the propylene-based wax (B) can be measured according to JIS K5902.

  However, when it is required to improve the workability of the resin composition or to improve the appearance of the obtained molded product, the acid value of the propylene-based wax (B) is preferably 1 to 70 mgKOH / g. The lower limit is more preferably 20 mgKOH / g, still more preferably 30 mgKOH / g, and particularly preferably 42 mgKOH / g. On the other hand, the upper limit is more preferably 60 mgKOH / g, still more preferably 50 mgKOH / g, and particularly preferably 46 mgKOH / g.

  On the other hand, when heat resistance and mechanical strength are required for the obtained molded product, the acid value of the propylene-based wax (B) is preferably 40 to 100 mgKOH / g, more preferably 50 to 100 mgKOH / g, More preferably, it is 60-100 mgKOH / g, Most preferably, it is 60-95 mgKOH / g, More preferably, it is 60-90 mgKOH / g, Most preferably, it is 70-90 mgKOH / g.

  In the conventional propylene-based resin composition, when the content ratio of the inorganic filler (C) is increased, the rigidity of the obtained molded body is improved, but the impact strength tends to be reduced. In order to improve the impact, an acid-modified propylene-based resin may be added. However, although the impact strength is improved, it is difficult to knead and the appearance tends to be poor. On the other hand, in the present invention, even if a relatively large amount of the inorganic filler (C) is included, the processability of the resin composition, the appearance of the obtained molded body, and the impact strength are hardly lowered. That is, according to the resin composition of the present invention, it is possible to obtain a molded article having excellent processability and excellent balance of appearance, rigidity and impact resistance. Although the detailed mechanism is not clear, the propylene-based wax (B) having an acid value in the above-described range is compatible with the surface of the polar inorganic filler (C) and covers the surface, whereby the inorganic filler ( C) It is thought to prevent aggregation between each other. Further, since the propylene-based wax (B) having a number average molecular weight within the above range includes a relatively low molecular weight and a structure similar to that of the propylene-based polymer (A), as a result, during processing of the propylene-based resin composition, That is, at the time of melting, it is considered that the fluidity of the entire resin composition can be improved and the dispersibility of the inorganic filler (C) can be effectively increased. Furthermore, when the propylene-based resin composition is solidified, the propylene-based wax (B) localized on the surface of the inorganic filler (C) is likely to have an affinity with the propylene-based polymer (A). As a result, it is considered that the impact resistance and rigidity derived from the propylene-based polymer (A) are compatible. From the above, it is considered that the resin composition is excellent in processability, and further, a molded article having an excellent balance of appearance, rigidity and impact resistance can be obtained.

  Further, the upper limit of the softening point (requirement (iii)) of the propylene-based wax (B) is more preferably 160 ° C, further preferably 150 ° C, and particularly preferably 145 ° C. The lower limit is more preferably 80 ° C, further preferably 90 ° C, particularly preferably 95 ° C, and most preferably 105 ° C. When the softening point of the propylene-based wax (B) is in the above range, the appearance of the molded product obtained from the resin composition becomes good, and the processability of the resin composition increases. Furthermore, the heat resistance and mechanical strength of the molded body are also increased.

  Furthermore, the ratio (Mw / Mn) (requirement (iv)) of the weight average molecular weight and the number average molecular weight of the propylene-based wax (B) is more preferably 5.0 or less, and further preferably 3.0 or less. . When the Mw / Mn is in the above range, since there are few low molecular weight components that cause a decrease in physical properties, the appearance of the resulting molded article is improved, and heat resistance and mechanical strength are increased.

Moreover, it is preferable that the density measured by JISK7112 of the propylene-type wax (B) is 900-950 kg / m < ³ >. When the density is in the range, the inorganic filler (C)
The dispersibility of is improved.

  The propylene-based wax (B) is not particularly limited as long as it is a compound that satisfies the above-described requirements (i) and (ii) and includes a propylene-derived structure as a structural unit. Specific examples of the propylene-based wax (B) are selected from the group consisting of a propylene homopolymer and a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms. An unsaturated carboxylic acid derivative monomer modification or air oxide of at least one polymer is included.

The propylene-based wax (B) is prepared from an unmodified propylene-based wax (B ′) such as a propylene homopolymer or the above-mentioned copolymer, which is modified with an unsaturated carboxylic acid monomer or air-oxidized. Can be obtained.
Hereinafter, the unmodified propylene wax (B ′) and the production method thereof will be described first, and then the propylene wax (B) modified with these will be described.

(About unmodified propylene wax (B '))
The unmodified propylene-based wax (B ′) can be made into a polymer obtained by copolymerizing propylene and, if necessary, another monomer in the presence of a stereospecific catalyst. The unmodified propylene wax (B ′) may be a propylene homopolymer or a copolymer mainly composed of propylene. Further, the unmodified propylene wax (B ′) may be obtained by thermally decomposing high molecular weight polypropylene. Further, from a composition containing an unmodified propylene wax (B ′), only the unmodified propylene wax (B ′) is fractionated (solvent fractionation) based on the difference in solubility in the solvent, or fractionated (molecularly). Distilled) may be used.

  The unmodified propylene-based wax (B ′) is preferably a propylene homopolymer and a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms.

  When the unmodified propylene-based wax (B ′) is a copolymer of propylene and ethylene, the constituent unit derived from propylene in the copolymer is preferably 60 to 99.5 mol%. The constituent unit amount derived from propylene is more preferably 80 to 99 mol%, further preferably 90 to 98.5 mol%, and particularly preferably 95 to 98 mol%. However, the total amount of the structural unit derived from propylene and the structural unit derived from ethylene is 100 mol%. When the unmodified propylene-based wax (B ′) is a propylene / ethylene copolymer, a molded article having an excellent balance of appearance, mechanical strength, and heat resistance can be obtained.

  When the unmodified propylene-based wax (B ′) is a copolymer of propylene, ethylene and at least one selected from α-olefins having 4 to 12 carbon atoms, the α-olefins having 4 to 12 carbon atoms Examples include 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1- Linear or branched α-olefins such as dodecene are included. Among these, 1-butene is particularly preferable. When the unmodified propylene-based wax (B ′) is the above copolymer, the copolymer may be a binary copolymer or a ternary or higher copolymer. .

  When the unmodified propylene-based wax (B ′) is a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms (provided that the above-mentioned propylene / ethylene copolymer is used) The amount of the structural unit derived from propylene in the copolymer is preferably 60 to 90 mol%, more preferably 65 to 88 mol%, still more preferably 70 to 85 mol%. Particularly preferred is 75 to 82 mol%. On the other hand, the total amount of structural units derived from ethylene or an α-olefin having 4 to 12 carbon atoms is preferably 10 to 40 mol%, more preferably 12 to 35 mol%, still more preferably 15 to 30 mol%. It is mol%, Most preferably, it is 18-25 mol%. However, the total amount of the structural unit derived from propylene, the structural unit amount derived from ethylene, and the structural unit derived from an α-olefin having 4 to 12 carbon atoms is 100 mol%.

  When the unmodified propylene-based wax (B ′) is a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms, and the composition is in the above range, the appearance is good. Can be obtained. The reason is that the time required for crystallization of the propylene wax (B) obtained by modifying the propylene wax can be increased. Therefore, when producing a molded object from a resin composition, the time which can flow a resin composition on a metal mold | die or a cooling process can be lengthened. As a result, it is considered that the surface properties of the obtained molded body are improved. Further, when the propylene-based wax (B) obtained from such an unmodified propylene-based wax (B ′) is used, the heat resistance and mechanical strength of the molded product tend to increase.

The unmodified propylene wax (B ′) described above may be obtained by directly polymerizing propylene or the like as described above, or obtained by thermally decomposing a high molecular weight propylene polymer. Also good. When thermally decomposing a high molecular weight propylene polymer (for example, polypropylene), it is preferable to thermally decompose at 300 to 450 ° C. for 5 minutes to 10 hours. In this case, the unmodified propylene wax (B ′) has an unsaturated terminal (vinylidene group). The unsaturated ^terminus can be confirmed by the 1 H-NMR measurement ^was measured by 1 H-NMR, it is preferable number of 1000 vinylidene group per carbon atom is 0.5 to 5 pieces . When the number of vinylidene groups is within this range, the compatibilizing effect of the propylene-based wax (B) on the inorganic filler (C) tends to increase. Further, the unmodified propylene wax (B ′) may be subjected to solvent fractionation in which only the unmodified propylene wax (B ′) is separated from the composition containing the unmodified propylene wax (B ′) by the difference in solubility in the solvent. It may be purified by a method such as distillation. Among these, the unmodified propylene wax (B ′) is preferably obtained by thermal decomposition.

  When propylene-based wax (B ′) is directly polymerized, various known production methods, for example, propylene monomer and ethylene monomer or α-olefin monomer by Ziegler / Natta catalyst or metallocene catalyst. A polymerization method or the like can be applied.

(Propylene wax (B))
The propylene-based wax (B) contained in the resin composition of the present invention is an acid-modified product of the above-mentioned unmodified propylene-based wax (B ′) (for example, a modified product or an air oxide with an unsaturated carboxylic acid derivative monomer). .

  When the propylene-based wax (B) is an air oxide of the above-mentioned unmodified propylene-based wax (B ′), the propylene-based wax (B) is obtained by bringing the unmodified propylene-based wax (B ′) as a raw material into a molten state. It is obtained by contacting with oxygen or oxygen-containing gas while stirring. The unmodified propylene-based wax (B ′) is usually in a molten state by heating to 130 to 200 ° C., preferably 140 to 170 ° C. The term “oxygen or oxygen-containing gas” in this specification includes pure oxygen (oxygen obtained by normal liquid air fractionation or water electrolysis, and may contain other components to the extent of impurities. Not only) but also a mixed gas of pure oxygen and other gases, such as air or ozone.

  As a method of bringing the unmodified propylene wax (B ′) into contact with oxygen or an oxygen-containing gas, the oxygen-containing gas is continuously supplied from the lower part of the reactor and brought into contact with the unmodified propylene wax (B ′). A method is preferred. In this case, the oxygen-containing gas is preferably supplied so that the amount of oxygen is equivalent to 1.0 to 8.0 NL per minute per 1 kg of the propylene-based wax (B ′).

  The propylene-based wax (B) may be a graft-modified product of an unmodified propylene-based wax (B ′) with an unsaturated carboxylic acid derivative monomer. The graft modified product can be prepared by a conventionally known method. For example, (1) an unmodified propylene wax (B ′) as a raw material and (2) an unsaturated carboxylic acid or derivative thereof are (3) melt-kneaded in the presence of a polymerization initiator such as an organic peroxide. It may be a method. Further, (1) unmodified propylene wax (B ′) and (2) unsaturated carboxylic acid or a derivative thereof are dissolved in an organic solvent, and the resulting composition is used as (3) an organic peroxide or the like. It can be obtained by kneading in the presence of a polymerization initiator.

  The kneading method at the time of preparing the propylene-based wax (B) is not particularly limited, and examples of the kneading apparatus include an autoclave, a Henschel mixer, a V-type blender, a tumbler blender, a ribbon blender, a single-screw extruder, a multi-screw extruder, and a kneader. A Banbury mixer or the like can be used. Among these, when a batch type apparatus such as an autoclave is used, each component can be more uniformly dispersed and reacted. In addition, compared to a continuous apparatus, a batch apparatus can easily adjust the residence time of the composition. Furthermore, since a long residence time can be obtained, it is relatively preferable to increase the modification rate and modification efficiency relatively easily.

  Here, examples of the unsaturated carboxylic acid or its derivative for modifying the unmodified propylene wax (B ′) include methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid-sec-butyl, acrylic Isobutyl acid, propyl acrylate, isopropyl acrylate, 2-octyl acrylate, dodecyl acrylate, stearyl acrylate, hexyl acrylate, isohexyl acrylate, phenyl acrylate, 2-chlorophenyl acrylate, diethylaminoethyl acrylate, Acrylic acid esters such as 3-methoxybutyl acrylate, diethylene glycol ethoxylate acrylate, and 2,2,2-trifluoroethyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacryl -Sec-butyl, isobutyl methacrylate, propyl methacrylate, isopropyl methacrylate, 2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, stearyl methacrylate, hexyl methacrylate, decyl methacrylate, phenyl methacrylate, methacrylic acid Methacrylic acid esters such as 2-chlorohexyl, diethylaminoethyl methacrylate, 2-hexylethyl methacrylate, -2,2,2-trifluoroethyl methacrylate; ethyl maleate, propyl maleate, butyl maleate, Maleic acid esters such as diethyl maleate, dipropyl maleate and dibutyl maleate; Fumarate esters such as ethyl fumarate, butyl fumarate and dibutyl fumarate; maleic acid, fumaric acid, Dicarboxylic acids such as conic acid, crotonic acid, nadic acid, methylhexahydrophthalic acid; and anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, glutaconic anhydride, and nadic anhydride .

  Among these, maleic anhydride is preferable. Maleic anhydride has a relatively high reactivity with the raw material unmodified propylene wax (B ′). Furthermore, maleic anhydride itself is stable and hardly changes in structure by polymerization. Therefore, when the propylene-based wax (B) is a propylene-based wax modified with maleic anhydride, the propylene-based wax (B) is stable even in a high temperature environment when molding the resin composition, and the inorganic filler ( C) It tends to act efficiently on the surface. As a result, it is considered that the appearance of the molded body obtained from the resin composition is improved and the balance of heat resistance, workability, and mechanical strength is improved.

  The propylene wax (B) described above may be a commercially available product.

  The propylene-based wax (B) may be a solid such as a powder, a tablet, or a block, and may be dispersed or dissolved in water or a solvent.

3. Inorganic filler (C)
As the inorganic filler (C), known inorganic fillers can be used without any particular limitation. For example, talc, mica, calcium carbonate, hydrotalcite, wollastonite, zonotlite, barium sulfate, sulfuric acid Calcium, calcium silicate, clay, glass fiber, glass beads, glass flake, carbon fiber, carbon black, graphite, gypsum, magnesium carbonate, magnesium oxide, titanium oxide, potassium titanate and other titanates, iron oxide, alumina, and more Includes metal powders such as zinc, copper, iron, aluminum, magnesium, silicon, and titanium, or metal fibers. Furthermore, pumice powder, pumice balun, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium titanate, calcium sulfite, asbestos, montmorillonite, bentonite, molybdenum sulfide and the like can be mentioned. These may be used alone or in combination. Of these, talc, mica, calcium carbonate, glass fiber and the like are preferable, and talc is particularly preferable.

  The inorganic filler (C) may have any shape such as a granular shape, a plate shape, a rod shape, a fiber shape, and a whisker shape. Moreover, the inorganic filler (C) may be a commercially available filler for polymer. For example, it may be commercially available in any form such as powder form, roving form, chopped strand form, compressed soul form, pellet (granulated) form, granule form and the like. When the inorganic filler (C) is talc, it is preferably processed into a powder form, a compressed soul form, or a granular form. The resin composition of the present invention may contain only one kind of inorganic filler (C), or may contain two or more kinds.

  The average particle diameter of the inorganic filler (C) is preferably 1 to 15 μm, more preferably 3 to 14 μm. The average particle diameter is a value measured by a laser diffraction method.

  The inorganic filler (C) is produced by various known production methods. For example, talc is manufactured by pulverizing the raw stone with an impact pulverizer or micron mill type pulverizer, or further pulverizing with a jet mill or the like and then adjusting the classification with a cyclone or micron separator. be able to.

  In addition, the inorganic filler (C) may be untreated or may be a surface-treated at least part of it. Examples of the surface treatment agent include an organic titanate coupling agent, an organic silane coupling agent, a modified polyolefin grafted with an unsaturated carboxylic acid or an anhydride thereof, a fatty acid, a fatty acid metal salt, a fatty acid ester, and the like. Moreover, these surface treating agents may be used individually by 1 type, and may be used in combination of 2 or more type.

4). Other resins The resin composition of the present invention may further contain other resins as long as the object of the present invention is not impaired. Although it does not restrict | limit in particular in content of other resin, It is preferable that it is about 0.1-30 mass parts with respect to 100 mass parts of propylene-type polymer (A).

5. Other Fillers The resin composition of the present invention may contain fillers other than inorganic fillers, that is, fillers made of organic substances (hereinafter also referred to as “organic fillers”). Examples of organic fillers include lignin, starch, wood flour, wood fibers, bamboo, cotton, cellulose, natural fibers such as nanocellulosic fibers, and products containing them.

  The resin composition may contain only 1 type of these organic fillers, and may contain 2 or more types. The content of these organic fillers is not particularly limited, but is preferably 70% by mass or less in total with respect to 100% by mass of the total mass of the propylene polymer (A) and the propylene wax (B). Preferably it is 30 mass% or less, More preferably, it is 20 mass% or less.

6). Other Additives The resin composition of the present invention may contain additives other than fillers. Other additives include those known in the polyolefin field. Examples of additives include nucleating agents, anti-blocking agents, pigments, dyes, lubricants, foaming agents, plasticizers, mold release agents, antioxidants, flame retardants, UV absorbers, antibacterial agents, surfactants, antistatic agents Agent, weather stabilizer, heat stabilizer, anti-slip agent, foaming agent, crystallization aid, anti-fogging agent, anti-aging agent, hydrochloric acid absorbent, impact modifier, crosslinking agent, co-crosslinking agent, crosslinking aid, adhesive Agents, softeners, processing aids and the like.

  The resin composition may contain only one type of additive or may contain two or more types. The content of these additives is not particularly limited as long as it does not impair the object of the present invention, but is 100% by mass relative to the total mass of the propylene polymer (A) and the propylene wax (B), respectively. It is preferable that it is about 0.05-70 mass%. The upper limit is more preferably 30% by mass.

7). Production Method of Resin Composition The resin composition of the present invention can be produced by dry blending or melt blending using any of various methods. Specific examples of the method include a tumbler, a V-type blender, a propylene-based polymer (A), a propylene-based wax (B), an inorganic filler (C), and other optional components, simultaneously or in any order. A blending method can be used with a Nauter mixer, a Banbury mixer, a kneading roll, a single-screw or twin-screw extruder, and the like. Alternatively, the propylene polymer (A), the propylene wax (B), the inorganic filler (C), and other optional components are once dispersed or dissolved in an arbitrary solvent, followed by natural drying or heat forced drying. Etc., and may be blended by appropriately drying.

  In general, it is preferable from the viewpoints of appearance and impact resistance of a molded article from which a melt blend is obtained rather than a dry blend. In particular, by sufficiently kneading with melt blending, the appearance and impact resistance of the resulting molded product tend to be increased. In particular, when two or more kinds of compounds are used in combination as the propylene-based wax (B), it is preferable from the viewpoint of handling that two or more kinds of propylene-based wax (B) are dry blended or melt blended in advance. As a method of melt blending, the above method, a method using a batch kettle, or the like is appropriately used.

  It is preferable that MFR (230 degreeC test load 2.16kgf) measured based on JISK7210 of the resin composition of this invention is 0.01-100g / 10min, More preferably, it is 0.1-50g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes, particularly preferably 1 to 20 g / 10 minutes, and further preferably 3 to 15 g / 10 minutes. When the MFR of the resin composition is in the above range, the balance between the processability of the resin composition, the heat resistance of the molded body and the mechanical strength is excellent.

  Further, the resin composition of the present invention is a torque after 10 minutes when melt kneaded and kneaded at a set temperature of 210 ° C. and a resin charge of 50 g, 50 rpm for 10 minutes using a biaxial batch melt blending device. The value (torque steady value) is preferably 4 N / m or less.

B. Molded body The molded body of the present invention can be produced by molding the resin composition into a desired shape by a conventionally known method such as injection molding, coating, extrusion molding, compression molding or the like. The shape of the molded body is not particularly limited, and is, for example, a film shape, a plate shape, a prismatic shape, a columnar shape, or the like. The molded product of the present invention can be used for the same applications as conventionally known propylene resins. Specifically, it can be used for automobile parts, home appliance parts, and the like.

  EXAMPLES Although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

1. Propylene polymer (A)
As propylene-based polymer (A), propylene / ethylene block copolymer (Prime Polymer Block Polypropylene Co., Ltd., trade name: Prime Polypro J707G (measured according to JIS K2170 at 230 ° C. and test load 2.16 kgf) Melt flow rate: 30 g / 10 min) was used.

2. Propylene Wax W1 and W2 having the composition shown in Table 1 were used as the propylene wax. W1 is a maleic anhydride-modified product of unmodified propylene wax (propylene / ethylene copolymer) (corresponding to the propylene wax (B) of the present invention), and W2 is an unmodified propylene wax (propylene). -An ethylene copolymer). These physical properties are shown in Table 1. Moreover, the measuring method of these compositions and each physical property value is as follows.

<Polymer composition>
The content ratio of the structural unit derived from ethylene and the structural unit derived from propylene was determined by analysis of ¹³ C-NMR spectrum. In Table 1, C3 means propylene and C2 means ethylene.

<Mn and Mw / Mn>
The number average molecular weight Mn and the molecular weight distribution (Mw / Mn) were determined from GPC measurement. The measurement was performed under the following conditions. The number average molecular weight Mn and the weight average molecular weight Mw were determined by preparing a calibration curve using commercially available monodisperse standard polystyrene.
Apparatus: Gel permeation chromatograph Alliance GPC2000 (manufactured by Waters)
Solvent: o-dichlorobenzene Column: TSKgel GMH6-HT × 2, TSKgel GMH6-HTL column × 2 (both manufactured by Tosoh Corporation)
Flow rate: 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution Temperature: 140 ° C.

<Softening point>
It measured according to JIS K2207.

<Density>
It was measured by the density gradient tube method of JIS K7112.

<Acid value>
It measured according to JIS K5902.

3. Inorganic filler (C)
As the inorganic filler (C), talc (manufactured by Asada Flour Milling Co., Ltd., trade name: JM-209P (average particle diameter (D50) 3.9 ± 0.4 μm)) was used.

[Example 1, Comparative Examples 1-3]
[Preparation of resin composition]
Propylene polymer (A), inorganic filler (C), propylene wax, and calcium stearate were mixed in the blending amounts shown in Table 2. The mixture was subjected to a lab plast mill (biaxial batch type melt blending device) manufactured by Toyo Seiki Co., Ltd. at a set temperature of 210 ° C., with a resin charge of 50 g (device batch volume = 60 cm ³ ), 50 rpm, and 10 minutes. The resin composition was obtained by melt-kneading. In addition, Table 2 shows the amount of propylene-based wax and the amount of calcium stearate with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the inorganic filler (C). Moreover, MFR of the said resin composition was measured with the following method.

<MFR>
The MFR of the obtained resin composition was measured according to JIS K7210 at 230 ° C. and 2.16 kgf.

(Evaluation of resin composition)
The processability during melt kneading of the resin composition was evaluated as follows. A molded body was produced from the obtained resin composition, and the tensile strength, tensile elongation, tensile modulus, Izod impact strength, and surface appearance were confirmed. The results are shown in Table 2.

<Processability>
Using a lab plast mill (biaxial batch type melt blending device) manufactured by Toyo Seiki Co., Ltd., melt kneading was performed under the conditions of a set temperature of 210 ° C., a resin charge amount of 50 g (device batch volume = 60 cm ³ ), 50 rpm, and 10 minutes. The torque value at the start of kneading was defined as the maximum torque value, and the torque value after 10 minutes was defined as the steady torque value. Based on the steady torque value, the workability was judged according to the following criteria.
○: Steady torque value 4N · m or less △: Steady torque value 4N · m or more, 4.5N · m or less ×: Steady torque value 4.5N · m or more

[Create specimen]
The obtained resin composition was press-molded under conditions of preheating at 210 ° C. for 5 minutes, pressure at 200 ° C. for 2 minutes, and cooling at 20 ° C. for 4 minutes to obtain a sheet-like molded body having a thickness of 2 mm.

[Evaluation of specimen]
The following evaluation was performed about the obtained test piece.

<Tensile test (tensile strength, tensile elongation, tensile modulus)>
Dumbbell test pieces (total length 50 mm, grip part width 10 mm, parallel part width 5 mm, thickness 2 mm) were prepared, and the tensile strength, tensile elongation, and tensile modulus were measured under the conditions of a chuck distance of 30 mm and a test speed of 50 mm / min. It was measured.

<Izod impact test>
Based on ASTM D256-10, an Izod impact test at room temperature was conducted. The notch was machined, the test piece was 63.5 mm (length) x 12.7 mm (width) x 2 mm (thickness), and the notch height was 10.16 mm.

<Surface appearance>
As for the surface appearance, the surface of the produced press sheet was visually confirmed, and surface roughness estimated to be an aggregate of inorganic filler (talc) was judged according to the following criteria.
○: No surface roughness △: Some surface roughness ×: Surface roughness

  As shown in Table 2 above, in Comparative Examples 2 and 3 that do not contain the propylene-based wax (B), Comparative Example 2 having a higher inorganic filler content has a higher tensile elastic modulus, but the impact strength is greatly reduced. doing. On the other hand, in the molded body of the resin composition of Example 1, although the tensile elastic modulus is high, a decrease in impact strength is suppressed and a relatively high value is shown. That is, the balance between tensile modulus and impact strength is excellent. The resin composition also has good processability. On the other hand, in Comparative Example 1 including a propylene-based wax having an acid value of less than 1 mgKOH / g, the tensile modulus is not sufficiently increased and impact resistance is low as compared with the case where the wax is not included. That is, the balance between elastic modulus and impact strength is reduced.

  The resin composition of the present invention has a high balance between rigidity and impact strength of the obtained molded body. Therefore, it can be applied not only to home appliance parts and the like, but also to applications that require high impact strength, such as automobile applications.

Claims (5)

A propylene polymer (A) having a melt flow rate (MFR) measured in a range of 0.01 to 100 g / 10 min in accordance with JIS K7210 and a test load of 2.16 kgf at 230 ° C., and a propylene wax (B) And an inorganic filler (C),
When the total content of the propylene polymer (A) and the inorganic filler (C) is 100 parts by mass, 1 to 70 parts by mass of the propylene polymer (A), the inorganic filler ( 30) to 99 parts by mass of C), 0.1 to 50 parts by mass of the propylene wax (B),
The propylene-based wax (B) satisfies the following (i) and (ii):
Resin composition.
(I) The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 300 to 20000 (ii) The acid value is in the range of 1 to 100 mgKOH / g. The propylene-based wax (B) is a propylene homopolymer, and at least one selected from the group consisting of propylene and a copolymer of propylene and at least one selected from ethylene and an α-olefin having 4 to 12 carbon atoms. Polymer unsaturated carboxylic acid derivative monomer modified product or air oxide,
The resin composition according to claim 1. The propylene polymer (A) is a propylene / ethylene block copolymer.
The resin composition according to claim 1 or 2. The inorganic filler (C) is talc.
The resin composition as described in any one of Claims 1-3. Obtained from the resin composition according to any one of claims 1 to 4,
Molded body.