JP2005200615A - Polyolefin based resin composition and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyolefin based resin composition containing woody materials and exhibiting excellent molding processability and impact strength, and to provide an injection-molded product composed of the resin composition containing the woody materials. <P>SOLUTION: The polyolefin based resin composition comprises (A) 16-35 pts. wt. of a polyolefin, (B) 30-80 pts.wt. of an esterified lignocellulosic or cellulosic substance obtained by esterification with a polybasic anhydride wherein the ratio of the polybasic anhydride introduced by the esterification is 0.5-20 wt% based on the esterified lignocellulosic or cellulosic substance, (C) 1-10 pts.wt. of a modified polyolefin, and (D) 3-25 pts.wt. of an ethylene/α-olefin elastomer, and the total of (A), (B), (C) and (D) is 100 pts.wt. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyolefin-based resin composition containing a wood-based material and an injection-molded body comprising the same, and more specifically, a polypropylene-based resin composition containing a wood-based material excellent in impact resistance for injection molding and the same The present invention relates to an injection molded body.

  It is widely practiced to obtain a composite material with improved appearance and elasticity by blending a wood-based material as a filler with a thermosetting resin such as melamine resin or phenol resin. On the other hand, a wood-based material may be blended with a thermoplastic resin such as polyolefin. In this case, however, the heat fluidity of the resin composition is lowered and the molding processability is lowered, and in some cases, the mechanical strength is lowered. Sometimes.

  In order to solve such problems, it has been practiced to esterify a wood-based material or blend a modified polyolefin resin and an organic peroxide. For example, Patent Document 1 describes that a composite material is obtained by reacting a composite resin composition containing a propylene-based resin, an esterified wood-based material, an organic peroxide, and optionally a modified polyolefin under heating. Has been. However, the resin composite material has a problem that it has high rigidity but low impact strength.

  Patent Document 2 describes that a composite material is obtained by reacting a resin composite material composed of polypropylene, polyethylene, a modified polyolefin, a lubricant, and a cellulosic material under heating. These resin composite materials Has a low melt flow rate and has a problem in molding processability, and also has a problem of low impact resistance as described above.

  On the other hand, Patent Document 3 and Patent Document 4 describe that a resin composite material comprising a polyolefin, a cellulosic material, and a lubricant is reacted under heating to obtain a composite material. There is a problem that the impact resistance is low.

JP-A-9-316248 Japanese Patent Laid-Open No. 11-12401 JP 2002-138202 A JP 2002-347909

  An object of the present invention is to provide a polyolefin-based resin composition that is a resin composition containing a wood-based material and is excellent in moldability and impact strength. Another object of the present invention is to provide an injection molded article comprising a resin composition containing the wood material.

  In view of the actual situation, the present inventor, as a result of earnest research, has a weight ratio within a certain range, a polyolefin, an esterified lignocellulose-based or cellulose-based material esterified with a polybasic acid anhydride, a modified polyolefin, and A resin composition comprising an ethylene / α-olefin elastomer, and a polyolefin, an esterified lignocellulosic or cellulosic material esterified with a polybasic acid anhydride, a modified polyolefin, ethylene / The present inventors have found that a resin composition comprising an α-olefin elastomer, a lubricant and / or a neutralizing agent can solve the above problems, and has completed the present invention.

That is, one of the present invention is
(A) 16 to 35 parts by weight of polyolefin, (B) an esterified lignocellulose-based or cellulose-based material esterified with a polybasic anhydride, wherein the ratio of the polybasic acid anhydride introduced by esterification is 40 to 80 parts by weight of esterified lignocellulosic or cellulosic material, 0.5 to 20% by weight based on the esterified lignocellulose or cellulosic material, (C) 1 to 10 parts by weight of modified polyolefin, and (D ) Ethylene / α-olefin elastomer 3 to 25 parts by weight, and the total of (A), (B), (C) and (D) is 100 parts by weight.

And one of the present invention is
(A) 16 to 35 parts by weight of polyolefin, (B) an esterified lignocellulose-based or cellulose-based material esterified with a polybasic anhydride, wherein the ratio of the polybasic acid anhydride introduced by esterification is 40 to 80 parts by weight of esterified lignocellulosic or cellulosic material that is 0.5 to 20% by weight based on the esterified lignocellulose or cellulosic material, (C) 1 to 10 parts by weight of modified polyolefin, (D) 3 to 25 parts by weight of an ethylene / α-olefin elastomer, (E) 0.1 to 10 parts by weight of a lubricant and / or (F) 0.1 to 5 parts by weight of a neutralizer, (A), (B), The sum of (C) and (D) relates to a polyolefin resin composition having 100 parts by weight.
Further, one aspect of the present invention is
The present invention relates to an injection-molded article comprising a polyolefin resin composition containing any one of the above woody materials.

  The polyolefin resin composition containing the woody material of the present invention is excellent in moldability and impact resistance. The polypropylene resin composition provided by the present invention is suitably used for injection-molded articles utilizing such physical properties.

  For the polyolefin (A) used as the component (A) of the polyolefin-based resin composition of the present invention, α-olefin homopolymers and copolymers can be used. Specific examples include homopolymers such as polyethylene, polypropylene, polybutene and poly-4-methyl-1-pentene; ethylene / propylene block copolymers, ethylene / propylene random copolymers, propylene / α-olefin copolymers Examples thereof include copolymers such as coalescence. Preferably, it is any of homopolypropylene, ethylene-propylene block copolymer, and ethylene-propylene random copolymer. Polyolefin (A) can also be used individually by 1 type, and can mix and use 2 or more types by arbitrary mixing ratios.

  The polyolefin (A) preferably has a melt flow rate (MFR: JIS-K-6758) at 230 ° C. and a load of 2.16 kg of 5 to 300 g / 10 minutes, more preferably 10 to 200 g / 10 minutes. Homopolypropylene, ethylene-propylene block copolymer, and ethylene-propylene random copolymer are desirable.

  The esterified lignocellulose-based or cellulose-based material (B) used in the present invention is an esterified product obtained by esterifying a lignocellulose-based or cellulose-based material with a polybasic acid anhydride. The ratio of the polybasic acid anhydride introduced by esterification is 0.5 to 20% by weight, preferably 1 to 10% by weight, based on 100% by weight of the lignocellulosic or cellulose material.

  The lignocellulose-based or cellulose-based material before esterification is a material containing lignocellulose, cellulose, or a derivative thereof, and those conventionally used as resin fillers can be used without limitation. The lignocellulosic or cellulosic material before esterification is a so-called woody material (hereinafter, the lignocellulosic or cellulosic material may be referred to as woody material). Specific examples include wood flour and woody material. For example, pulp. The raw wood and tree species of the woody material before esterification are not particularly limited. In addition, as the woody material before esterification, a woody material obtained from a woody material or an unused woody material as industrial waste in the wood industry can be used, and resources can be effectively used. Furthermore, what neutralized tiric acid (repric acid, acetic acid, formic acid, etc.) with urea etc. can also be used.

  Examples of polybasic acid anhydrides used for esterification of lignocellulosic or cellulosic materials include maleic anhydride, phthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, itaconic anhydride, anhydrous Examples include adipic acid. Among these, maleic anhydride, phthalic anhydride, succinic anhydride and the like, which are industrially inexpensive, are preferable. Such polybasic acid anhydrides can be used alone or in combination of two or more.

  The esterified wood-based material (B) is mixed by heating and kneading the wood-based material and the polybasic acid anhydride with the known batch-type pressure kneading apparatus or continuous kneading apparatus so as to achieve the esterification amount. Can be manufactured.

  As these esterification methods, methods detailed in JP-B-3-37490, JP-A-3-58881, JP-A-4-36843 and the like can be employed. (B) A component can also be used individually by 1 type and can also use 2 or more types together.

The modified polyolefin (C) used in the present invention was modified with a modifying compound such as maleic anhydride, dimethyl maleate, diethyl maleate, acrylic acid, methacrylic acid, tetrahydrophthalic acid, glycidyl methacrylate, hydroxyalkyl methacrylate, etc. Examples include polyolefins. Examples of the polyolefin before modification include the same as the polyolefin (A). Preferably, polypropylene modified with maleic anhydride is used. The amount of the modified portion introduced (modified amount) with respect to 100% by weight of the polyolefin before modification is usually 0.1 to 3% by weight, preferably 0.3 to 2% by weight.
The MFR (MFR: JIS-K-6758) having a load of 2.16 kg at 230 ° C. of the modified polyolefin (C) is from the viewpoint of heat generation when kneading and injection molding a polypropylene resin composition containing a wood material. 10-500 g / 10min is preferable, More preferably, it is 20-200 g / 10min.

For the ethylene / α-olefin elastomer (D) of the present invention, a copolymer of ethylene and α-olefin can be used. Specific examples of the α-olefin include 1-butene, isobutene, 1-pentene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene and 1-octene. 1-decene and 1-dodecene, which may be used alone or in combination, preferably 1-butene, 1-hexene and 1-octene.
The density of the ethylene / α-olefin elastomer (D) is 0.88 g / cm ³ or less, preferably 0.85 to 0.875 g / cm ³ , more preferably 0.855 to 0.875 g / cm ^3. It is. When the density exceeds 0.88 g / cm ³ , the dispersibility of the component (D) in the polyolefin may be poor, and the impact strength may be lowered. If the density is less than 0.85 g / cm ³ , it may become too soft and the rigidity may be insufficient.
From the viewpoint of impact strength, the ethylene / α-olefin elastomer (D) 190 ° C. and 2.16 kg load MFR (MFR: JIS-K-6758) is usually 0.3 to 25 g / 10 min. Is 0.5 to 20 g / 10 min, more preferably 1 to 10 g / 10 min.

The method for producing the ethylene / α-olefin elastomer (D) is not particularly limited, and examples thereof include a production method by a known polymerization method using a 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.
As a known polymerization method, for example, a method in which ethylene and an α-olefin are copolymerized in an inert organic solvent such as a hydrocarbon compound can be mentioned.

Examples of the lubricant (E) of the present invention include hydrocarbon external lubricants such as polyolefin wax and liquid paraffin, external lubricants such as metal soaps and ester lubricants, and internal lubricants such as fatty acid amides. It is a fatty acid amide. More preferably, the fatty acid amide is a compound represented by the general formula RCONH ₂ (wherein R represents an alkyl group or alkenyl group having 5 to 21 carbon atoms), and examples thereof include lauric acid amide and stearic acid amide. Oleic acid amide, pehenic acid amide, erucic acid amide and the like, and erucic acid amide is most preferable. More preferably, the polyolefin wax is a polyethylene or polypropylene wax having an average molecular weight (Mn) of 15000 or less. Most preferably, it is a polypropylene wax and has an average molecular weight (Mn) of 10,000 or less. These lubricants may be used in combination of a plurality of types such as a combination of polyolefin wax and fatty acid amide.

  Examples of the neutralizing agent (F) of the present invention include metal soaps, inorganic oxides, inorganic hydroxides, anion exchange layered compounds, etc., preferably inorganic hydroxides, anion exchange layered compounds. More preferably, calcium hydroxide, hydrotalcite, or dolomite.

Component (A) to (F) are blended in an amount of 16 to 35 parts by weight of polyolefin (A), esterified lignocellulose-based or cellulose-based substance (B) 40 to 80 parts by weight esterified with polybasic acid anhydride. The modified polyolefin (C) is 1 to 10 parts by weight, the ethylene / α-olefin elastomer (D) is 3 to 25 parts by weight, and the total of (A), (B), (C) and (D) is 100 parts by weight. It is.
The lubricant (E) may be added to suppress heat generation during kneading or injection molding, and is 0% relative to a total of 100 parts by weight of the above (A), (B), (C) and (D). .1 to 10 parts by weight.
Further, the neutralizing agent (F) may be added to suppress the acid component generated during molding, and is based on 100 parts by weight of the total of the above (A), (B), (C) and (D). 0.1 to 5 parts by weight.

When the amount of the polyolefin (A) is less than 16 parts by weight, it is difficult to solidify at the time of injection molding, and molding becomes difficult, and when it exceeds 35 parts by weight, the rigidity is lowered. Preferably, it is 20-30 weight part.
When the amount of the esterified lignocellulose-based or cellulose-based material (B) esterified with a polybasic acid anhydride is less than 40 parts by weight, the rigidity is insufficient, and when the amount exceeds 80 parts by weight, The heat generation during molding becomes large, and kneading and molding cannot be performed. In addition, the balance of physical properties deteriorates due to deterioration of the lignocellulosic or cellulosic material due to heat generation. Preferably, it is 50-80 weight part, More preferably, it is 60-70 weight part.
When the amount of the modified polyolefin (C) is less than 1 part by weight, the effect as a compatibilizing agent is reduced, and the impact resistance is lowered. Moreover, when it exceeds 10 weight part, rigidity and impact resistance will fall. Preferably, it is 3 to 8 parts by weight.
When the amount of the ethylene / α-olefin elastomer (D) is less than 3 parts by weight, impact resistance is lowered. When the amount exceeds 25 parts by weight, heat generation during kneading increases, the lignocellulose-based or cellulosic material deteriorates, and the rigidity also decreases. Preferably, it is 5 to 20 parts by weight.
Lubricant (E) may be added to suppress heat generation during kneading or injection molding, but if it is less than 0.1 parts by weight, the effect of suppressing heat generation is small, and if it exceeds 10 parts by weight, Adversely affects sex, etc. The amount is preferably 1 to 8 parts by weight, and more preferably 1 to 5 parts by weight. When using a plurality of types of lubricants, the total amount is used within the above range.
The neutralizing agent (F) may be added to suppress the acid component generated during molding. When the amount is less than 0.1 parts by weight, the acid suppressing effect is small, and even when added in excess of 5 parts by weight, the effect is achieved. Does not change so much, and the dispersion of the neutralizing agent becomes poor. Preferably, it is 0.5-3 weight part.

  The components (A) to (F) can be blended in an amount within the above general range, but it is most preferable that all components be blended in an amount within a preferred range. However, it is also preferable that a certain component is in a preferable range and another component is blended in an amount in a general range.

  The polyolefin-based resin composition of the present invention is a composition in which the components (A) to (D) and (E) and / or (F) components added as necessary are blended in the above blending amounts.

  The polyolefin resin composition of the present invention includes inorganic fillers such as talc, calcium carbonate, mica, glass fibers, etc., or organic fillers such as polyester and polyamide fibers, in addition to flame retardants and stabilizers. Addition of various additives such as UV absorbers, antioxidants, antistatic agents, copper damage inhibitors, foaming agents, nucleating agents, antifoaming agents, crosslinking agents, plasticizers, and coloring agents such as dyes and pigments An agent can be added.

  In the polyolefin-based resin composition of the present invention, the components (A) to (D) and other components added as necessary are mixed in the blending amount, and the mixture is mixed at 150 to 200 ° C., preferably 160 to 190. It can be produced by heating and kneading and reacting at 30 ° C. for 30 seconds to 30 minutes, preferably 1 to 20 minutes.

  The mixing method of each component is not specifically limited, It can mix with mixers, such as a Henschel mixer, and it is preferable to make uniform. The heat kneading method is not particularly limited as long as it can be heat kneaded under the above conditions, and for example, it can be carried out by a blender, kneader, mixing roll, Banbury mixer, monoaxial or biaxial extruder.

  The following manufacturing method can be illustrated as a preferable manufacturing method. That is, after mixing each component with a Henschel mixer at room temperature and homogenizing, the obtained mixture was kneaded with a twin-screw extruder while setting the kneading zone to the above temperature, and the polyolefin resin composition of the present invention Get things. In addition, since the gas by decomposition | disassembly of esterified wood type material (B) will generate | occur | produce when temperature is 200 degreeC or more, it needs to be careful so that granulation temperature may not exceed 200 degreeC. Therefore, it is preferable to use a twin screw extruder or the like that is effective in cooling control.

  The polyolefin resin composition of the present invention thus obtained is a material excellent in impact resistance and excellent in heat fluidity even though a woody material is blended. It can be easily molded into an arbitrary shape by a molding method such as injection molding.

  In addition, the polyolefin resin composition of the present invention is improved in the interfacial bonding between the polyolefin (A) and the esterified wood material (B) by adding the modified polyolefin (C). The obtained molded product is excellent in mechanical strength, for example, tensile strength, bending strength, impact strength strength and the like.

  The injection-molded article of the present invention is obtained by molding the polyolefin resin composition of the present invention by a known injection molding method.

  Next, examples of the present invention will be described. Although the manufacturing method of the composition used in each example, the shaping | molding method of a molded article, and the measuring method of a physical property are as follows, this invention is not limited to these Examples.

The measuring methods of physical property values in Examples and Comparative Examples are 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 that was notched after molding was evaluated. Measurement temperature was 23 degreeC and -30 degreeC.

(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 specimen were determined, and Q value = weight average molecular weight / number average molecular weight (Mw / Mn) was determined as a measure of 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 formula.
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 was 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 (% by 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: Obtained by calculation.
[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.

(sample)
(A) Polyolefin (1) Propylene-ethylene block copolymer (BC-1)
The molecular weight distribution (Q value) of the propylene homopolymer part (first segment) is 4.5, the intrinsic viscosity ([η] P) is 1.0 dl / g, and the isotactic pentad fraction is 0. .99, and the intrinsic viscosity ([η] EP) of the propylene-ethylene random copolymer portion (second segment) is 2.5 dl / g, and the weight relative to the propylene-ethylene block copolymer (BC-1) The proportion was 26.0% by weight, and the ethylene content of the propylene-ethylene random copolymer portion was 34.2% by weight. MFR (230 ° C.): 30 g / 10 min

(2) Propylene-ethylene block copolymer (BC-2)
The molecular weight distribution (Q value) of the propylene homopolymer portion (first segment) is 4.0, the intrinsic viscosity ([η] P) is 0.81 dl / g, and the isotactic pentad fraction is 0. The intrinsic viscosity ([η] EP) of the propylene-ethylene random copolymer portion (second segment) is 6.1 dl / g, and the weight relative to the propylene-ethylene block copolymer (BC-2) The proportion was 12.4% by weight, and the ethylene content of the propylene-ethylene random copolymer portion was 31.5% by weight. MFR (230 ° C.): 80 g / 10 min
(3) Propylene-ethylene block copolymer (BC-3)
The molecular weight distribution (Q value) of the propylene homopolymer portion (first segment) is 4.0, the intrinsic viscosity ([η] P) is 1.04 dl / g, and the isotactic pentad fraction is 0. .97, and the intrinsic viscosity ([η] EP) of the propylene-ethylene random copolymer portion (second segment) is 2.5 dl / g, and the weight relative to the propylene-ethylene block copolymer (BC-3) The proportion was 20.5% by weight, and the ethylene content of the propylene-ethylene random copolymer portion was 40.0% by weight. MFR (230 ° C.): 30 g / 10 min

(B) Esterified lignocellulosic or cellulosic material Wood flour: P Super (manufactured by Rettenmeier, Germany)
Esterified wood flour: Maleic anhydride-esterified wood flour (hereinafter referred to as MA wood flour) in which P super is esterified with maleic anhydride and the maleic anhydride introduced by esterification is 5 wt% with respect to the wood flour. (May be abbreviated).

(C) Modified polyolefin (1) Maleic acid modified polypropylene (MPP-1)
Maleic acid-modified polypropylene (degree of maleic acid modification: 0.6% by weight, MFR (230 ° C.): 70 g / 10 min) produced by the method described in JP-A-2002-308947 was used.

(D) Ethylene / α-olefin elastomer As the ethylene / α-olefin elastomer, the following ethylene / 1-octene copolymer (elastomer 1) and ethylene / 1-butene copolymer (elastomer 2) were used.
(1) Elastomer 1
Engage 8200 (ethylene / 1-octene copolymer density: 0.87 g / cm ³ , MFR (190 ° C.): 5 g / 10 min) manufactured by DuPont Dow Elastomer Co., Ltd. was used.
(2) Elastomer 2
An ethylene / 1-butene copolymer (density: 0.87 g / cm ³ , MFR (190 ° C.): 15 g / 10 min) produced using a metallocene catalyst was used.

(E) Lubricant (1) Lubricant 1
Erucic acid amide NewS manufactured by Nippon Seika Co., Ltd. was used as the fatty acid.
(2) Lubricant 2
As a polyolefin wax, Viscor 660-P manufactured by Sanyo Chemical Co., Ltd. was used.

(F) Neutralizing agent Hydrotalcite DHT-4A manufactured by Kyowa Chemical Co., Ltd. was used.

<< Manufacturing method of polyolefin resin composition >>
Components (A) to (D) and other components are fed into a hopper of a twin-screw extruder by a feeder that is controlled by the feed weight per hour, and the barrel set temperature: 190 ° C. Screw rotation speed: 120 rpm, the resin temperature is The polyolefin resin composition was obtained by heating and kneading at 180 to 190 ° C. at the exit of the extruder. The residence time (heat kneading time) was 1 minute.

<Molded product molding method for physical property evaluation>
(Injection molding)
Test pieces for evaluating physical properties were produced under the following injection molding conditions. The polypropylene resin composition obtained above is dried at 120 ° C. for 4 hours in 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 70 ° 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.

Examples 1-8, Comparative Examples 1-4
Polypropylene, maleic anhydride esterified wood flour, modified polyolefin, ethylene / α-olefin elastomer and other components in the blending ratio shown in Table 1 were extruded from a twin screw extruder to obtain a polyolefin resin composition for molding. The composition was dried at 120 ° C. for 4 hours with a dryer, and then the physical properties were measured. The results are also shown in Table 1.

  As is apparent from Table 1, the polyolefin resin composition according to the present invention had an impact strength of 70 J / m or more, and good moldability and appearance as compared with the resin composition according to the comparative example. . On the other hand, the impact strength of the resin composition according to Comparative Example 1 in which the modified polyolefin, which is outside the scope of the present invention, was removed was as small as 43 J / m. In addition, the impact strength of the resin compositions according to Comparative Example 2 and Comparative Example 3 from which the modified polyolefin and the ethylene / α-olefin elastomer were omitted was significantly reduced. Moreover, the impact strength of the resin composition according to Comparative Example 4 in which the ethylene / α-olefin elastomer was omitted was lowered.

  The field of application of the polyolefin-based resin composition of the present invention is not particularly limited, and is suitably used in the fields of electrical insulating materials, industrial parts materials, building materials, automobile parts, etc. for which thermoplastic resins have been conventionally used. In particular, it can be particularly suitably used as a raw material for automobile parts obtained by injection molding.

  Specifically, it is preferably used as an automobile interior material, and can be used as a material for door trims, floors, steering, pillars, instrument panels, instrument panel accessories, etc., but more preferably steering, instrument panel accessories. Can be used as floor material.

Claims (4)

(A) 16-35 parts by weight of polyolefin, (B) esterified lignocellulosic or cellulosic material esterified with polybasic anhydride, wherein the proportion of polybasic anhydride introduced by esterification is 30 to 80 parts by weight of esterified lignocellulosic or cellulosic material that is 0.5 to 20% by weight based on the esterified lignocellulose or cellulosic material, (C) 1 to 10 parts by weight of modified polyolefin, and (D ) A polyolefin-based resin composition comprising 3 to 25 parts by weight of an ethylene / α-olefin elastomer, wherein the total of (A), (B), (C) and (D) is 100 parts by weight. The polyolefin resin composition according to claim 1, wherein 0.1 to 10 parts by weight of (E) lubricant is further added to 100 parts by weight of the total of (A), (B), (C) and (D). . The polyolefin according to claim 1 or 2, wherein (F) 0.1 to 5 parts by weight of a neutralizer is further added to 100 parts by weight of the total of (A), (B), (C) and (D). -Based resin composition. An injection-molded article comprising the polyolefin-based resin composition according to any one of claims 1 to 3.