JP7356317B2 - Polypropylene resin composition - Google Patents

Description

The present invention relates to a polypropylene resin composition containing a biomass material, an extruded foam, an injection foam, a sheet, a thermoformed article, and a blow molded article made of the polypropylene resin composition.

Polypropylene is used in all industries because it has excellent physical properties including heat resistance and can be manufactured at low cost. In recent years, there has been a need to reduce CO2 emissions from the perspective of global warming and environmental protection, and as a countermeasure, the use of biomass materials that can adsorb and fix CO2 in the atmosphere has been proposed in many fields. For example, a composition has been proposed in which polypropylene is composited with a biomass material such as wood flour (Patent Document 1). Polypropylene resin compositions, which are made by combining polypropylene with wood powder, are semi-plastic, but can retain the properties of wood, such as the scent and color tone, and are artificial. Its uses are expanding, including being used for wood.

When compounding polypropylene with biomass material and molding the compounded polypropylene resin composition into various molded products, a processing temperature of, for example, about 180 to 200°C is required, but at such high temperatures, biomass The problem is that the material emits a significant odor, which has a significant negative impact on workers. If the processing temperature is lowered to suppress the generation of odor, problems arise in that processing becomes difficult and the appearance quality of the resulting molded product deteriorates.

In order to solve such problems during molding processing, a propylene resin composition consisting of 10 to 90 parts by weight of a propylene resin with a melting point of 110 to 150°C and 90 to 10 parts by weight of a lignocellulose or cellulose material has been developed. A method has been proposed (Patent Document 2). According to the propylene resin composition of Patent Document 2, it has been shown that not only can the molding temperature be lowered and the generation of odor can be suppressed, but also the odor can be improved even at high molding temperatures.

Japanese Patent Application Publication No. 6-80832 Japanese Patent Application Publication No. 2007-169612

Although the propylene-based resin composition of Patent Document 2 has been improved in terms of odor, it has a problem in that it has a strong plastic feel in terms of color tone and the like. Furthermore, there is a problem in that the blending of lignocellulosic or cellulose materials deteriorates the melt spreadability of the propylene resin, resulting in restrictions on the molding method. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a polypropylene resin composition with improved odor, suppressed plastic feel, and suppressed deterioration of melt spreadability.

The first polypropylene resin composition of the present invention comprises 5 to 85% by mass of a polypropylene resin (A1) having a melting point of 150°C or higher and having the following properties (a-1); (B) 5 to 85% by mass, and biomass material (C) 10 to 80% by mass (however, the total mass of (A1), (B) and (C) is 100% by mass). shall be.
Characteristics (a-1): Melt tension (MT) (unit: g) is log (MT) ≧ -0.9 × log (MFR) + 0.7, and
Satisfies log(MT)≧1.15

In addition, the second polypropylene resin composition of the present invention contains 10% by mass or more of a polypropylene resin (A1) having a melting point of 150°C or higher and having the following property (a-1) and the following property (a-2). A total of 15 to 85% by mass of a polypropylene resin (A2) having a melting point of 150°C or higher and the polypropylene resin (A1) , 5 to 75 % by mass of a polypropylene resin (B) having a melting point of 110°C or higher and lower than 150°C, and It is characterized by containing 10 to 80% by mass of biomass material (C) (however, the total mass of (A1), (A2), (B) and (C) is 100% by mass).
Characteristics (a-1): Melt tension (MT) (unit: g) is log (MT) ≧ -0.9 × log (MFR) + 0.7, and
Characteristic (a-2) that satisfies log(MT)≧1.15: Melt tension (MT) (unit: g) is log(MT)<-0.9×log(MFR)+0.7, and log(MT ) < 1.15.

Polypropylene resin (A1), or polypropylene resin (A1) and polypropylene resin (A2) are each independently produced from a propylene homopolymer, a propylene/ethylene block copolymer, or a propylene/ethylene/1-butene block copolymer. The polypropylene resin may be one or more polypropylene resins selected from the group consisting of:

In addition, the polypropylene resin (B) includes propylene/ethylene random copolymer, propylene/1-butene random copolymer, propylene/ethylene/1-butene random copolymer, propylene/ethylene random block copolymer, propylene/ It is preferable to use one or more polypropylene resins selected from the group consisting of ethylene/1-butene random block copolymers.

Furthermore, the polypropylene resin (B) preferably has the following properties (b-1) and/or (b-2).
(b-1) Q value is 5.0 or less (b-2) Soluble content at 40°C or less measured by temperature rising elution fractionation (TREF) method is 4.0% by mass or less

The biomass material (C) is preferably one or more plant-derived fillers selected from the group consisting of wood, pulp, bamboo, sugarcane (bagasse), rice husk, and rice (starch).

In addition, the total of the above-mentioned polypropylene resin (A1), polypropylene resin (B) and biomass material (C), or the total of polypropylene resin (A1), polypropylene resin (A2), polypropylene resin (B) and biomass material (C) A polypropylene resin composition containing 1 to 50 parts by mass of the thermoplastic elastomer (D) per 100 parts by mass of 100% by mass is preferred.

Further, the extruded foam molded product, injection foam molded product, sheet molded product, thermoformed product, or blow molded product is preferably made of the above-mentioned polypropylene resin composition.

The polypropylene resin composition of the present invention has excellent environmental protection performance, suppresses odor and plastic feel, and can suppress deterioration of melt spreadability.

The first polypropylene resin composition of the present invention contains 5 to 85% by mass of polypropylene resin (A1), 5 to 85% by mass of polypropylene resin (B), and 10 to 80% by mass of biomass material (C), and these The total is 100% by mass.

The second polypropylene resin composition of the present invention contains a total of 5 to 85% by mass of polypropylene resin (A1) and polypropylene resin (A2), 5 to 85% by mass of polypropylene resin (B), and 10 to 10% of biomass material (C). ~80% by mass, and the total of these is 100% by mass.

The first polypropylene resin composition and the second polypropylene resin composition both contain a polypropylene resin (A1), a polypropylene resin (B), and a biomass material (C), and improve odor while suppressing the plastic feel. This suppresses the deterioration of melt spreadability and has excellent environmental protection ability. In addition, in this specification, "polypropylene resin (A1)" that constitutes the first polypropylene resin composition, and "a blend of polypropylene resin (A1) and polypropylene resin (A2)" that constitutes the second polypropylene resin composition "Product" may be simply written as "Polypropylene resin (A)."

Polypropylene resin (A1)
The polypropylene resin (A1) preferably has a melting point of 150°C or higher, more preferably 153°C or higher, even more preferably 155°C or higher. The melting point of the polypropylene resin (A1) is preferably 170°C or lower. By setting the melting point of the polypropylene resin (A1) to 150° C. or higher, rigidity and heat resistance are increased. Furthermore, the melting point can be adjusted by adjusting the amount of comonomers such as ethylene and butene introduced during propylene polymerization.

Here, in this specification, the melting point is a value measured by a differential scanning calorimeter (DSC). Using a Seiko differential scanning calorimeter, take approximately 5 mg of a sample, hold it at 200°C for 5 minutes, cool it to 40°C at a cooling rate of 10°C/min, and then increase the temperature at a rate of 10°C/min. Obtain the melting point from the heat of fusion curve obtained when melting at . That is, the maximum peak temperature of the heat of fusion curve is defined as the melting point.

The polypropylene resin (A1) has a melt flow rate (MFR) measured at 230° C. and a load of 2.16 kg, preferably from 0.1 to 150 g/10 minutes, more preferably from 1 to 100 g/10 minutes. Here, MFR is a value measured at 230° C. and a load of 2.16 kg in accordance with JIS K7210. The MFR of the polypropylene resin (A1) can be adjusted by controlling the hydrogen concentration during polymerization. When the MFR is 0.1 g/10 minutes or more, the load on the extruder is suppressed during extrusion molding of the sheet, and productivity is improved, which is preferable.

The polypropylene resin (A1) has the following characteristic (a-1) regarding the relationship between melt tension and MFR.
(a-1): The melt tension (MT) (unit: g) of the polypropylene resin (A1) is
Satisfies log(MT)≧-0.9×log(MFR)+0.7, or log(MT)≧1.15

The melt tension (MT) of the polypropylene resin (A1) preferably satisfies log(MT)≧−0.9×log(MFR)+0.9, or log(MT)≧1.15. More preferably, log(MT)≧−0.9×log(MFR)+1.1 or log(MT)≧1.15 is satisfied.

There is no upper limit to the melt tension of polypropylene resin (A1), but if it is too large, the ductility will decrease, the ability to form into a mold during thermoforming will deteriorate, and in extreme cases, the molded product will tear. Preferably, log(MT)≦1.48 (MT≦30.2).

Here, in this specification, melt tension (MT) is a value measured using a capillograph. The resin is placed in a cylinder with a diameter of 9.55 mm heated to a temperature of 230° C., and the molten resin is extruded through an orifice with a diameter of 2.0 mm and a length of 40 mm at a pushing speed of 20 mm/min. The tension detected in the pulley when the extruded resin is withdrawn at a speed of 4.0 m/min is measured, and this is defined as the melt tension (MT).

The polypropylene resin (A1) has a mm fraction of three chains of propylene units determined by ¹³ C-NMR, preferably 95% or more, more preferably 96% or more, and still more preferably 97% or more.

The mm fraction is the proportion of three chains of propylene units in which the direction of the methyl branch in each propylene unit is the same among three chains of arbitrary propylene units consisting of head-to-tail bonds in the polymer chain, and the upper limit is 100%. be. This mm fraction is a value indicating that the three-dimensional structure of the methyl group in the polypropylene molecular chain is isotactically controlled, and the higher it is, the more highly isotactically controlled it is. When the mm fraction is 95% or more, drawdown resistance during thermoforming is improved.

The method for measuring the mm fraction of three chains of propylene units of the polypropylene resin (A1) by ¹³ C-NMR is as follows.
After completely dissolving 375 mg of the sample in 2.5 ml of deuterated 1,1,2,2-tetrachloroethane in an NMR sample tube (10φ), the measurement was performed at 125°C using the proton complete decoupling method under the following conditions. do. The chemical shift is set at 74.2 ppm for the central peak of the three peaks of deuterated 1,1,2,2-tetrachloroethane. Chemical shifts of other carbon peaks are based on this.
Flip angle: 90 degrees Pulse interval: 10 seconds Resonance frequency: 100 MHz or more Integration number: 10,000 times or more Observation range: -20 ppm to 179 ppm
Number of data points: 32,768

The mm fraction is determined using the ¹³ C-NMR spectrum measured under the above conditions. Spectrum assignment is performed with reference to Macromolecules, (1975), Vol. 8, p. 687, and Polymer, Vol. 30, p. 1350 (1989). A more specific method for determining the mm fraction is described in detail in paragraphs [0053] to [0065] of JP-A No. 2009-275207, and this method is also used in the present invention. .

The polypropylene resin (A1) preferably has a Q value (Mw/Mn) of 3.5 to 10 determined from the weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography (GPC). , more preferably 3.7 to 8, still more preferably 4 to 6. When the Q value of the polypropylene resin (A1) is within the above range, the molding processability is particularly excellent when extrusion molding a sheet, which is preferable.

The polypropylene resin (A1) has a molecular weight distribution Mz/Mw determined from Z average molecular weight (Mz) and Mw measured by gel permeation chromatography (GPC), preferably 2.5 to 10, more preferably 2.8. -8, more preferably 3-6. When Mz/Mw of the polypropylene resin (A1) is within the above range, the molding processability is particularly excellent when extrusion molding a sheet.

In this specification, the definitions of Mn, Mw, and Mz are based on the matters described in "Fundamentals of Polymer Chemistry" (edited by the Society of Polymer Science, Tokyo Kagaku Dojin, 1978), and Mn, Mw, and Mz are It can be calculated from the molecular weight distribution curve determined by GPC.

In the present invention, the GPC measurement method is as follows.
・Equipment: Waters GPC (ALC/GPC 150C)
・Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm)
・Column: Showa Denko AD806M/S (3 columns)
・Mobile phase solvent: orthodichlorobenzene (ODCB)
・Measurement temperature: 140℃
・Flow rate: 1.0ml/min
・Injection amount: 0.2ml
- Preparation of sample: For the sample, prepare a 1 mg/mL solution using ODCB (containing 0.5 mg/mL BHT), and dissolve at 140° C. for about 1 hour.

The retention capacity obtained by GPC measurement is converted into molecular weight using a standard polystyrene calibration curve prepared in advance. As standard polystyrene, the following brands manufactured by Tosoh Corporation are used.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000

A calibration curve is created by injecting 0.2 mL of a solution in which each standard polystyrene is dissolved at 0.5 mg/mL in ODCB (containing 0.5 mg/mL BHT). The calibration curve uses a cubic equation obtained by approximation using the least squares method.
In addition, the following numerical value is used for the viscosity formula [η]=K×M ^α used for conversion to molecular weight.
PS: K=1.38×10 ⁻⁴ , α=0.7
PP: K=1.03× ^10-4 , α=0.78

The polypropylene resin (A1) preferably has a long chain branched structure.
A branching index g' can be cited as a direct indicator of whether a polypropylene resin has a long chain branched structure. The branching index g' is the ratio of the intrinsic viscosity [η]br of a polymer having a long chain branched structure to the intrinsic viscosity [η]lin of a linear polymer having the same molecular weight, that is, [η]br/[η]lin, It can be said that it has a long chain branched structure if g'<1.

The definition of the branching index g' is described, for example, in "Developments in Polymer Characterization-4" (J.V. Dawkins ed. Applied Science Publishers, 1983), and is an index known to those skilled in the art. There is.

The branching index g' can be obtained as a function of the absolute molecular weight Mabs, for example, by using a light scatterometer as described below and a GPC equipped with a viscometer as a detector.

When the absolute molecular weight Mabs determined by light scattering is 1 million, the polypropylene resin (A1) preferably has a branching index g' of 0.30 or more and less than 1.00, more preferably 0.55 or more and less than 1.00. Below, it is more preferably 0.75 or more and 0.96 or less, most preferably 0.78 or more and 0.95 or less.

The method for calculating the branching index g' is as follows.
Alliance GPCV2000 manufactured by Waters is used as a GPC device equipped with a differential refractometer (RI) and a viscosity detector (Viscometer). Further, as a light scattering detector, a multi-angle laser light scattering detector (MALLS) DAWN-E manufactured by Wyatt Technology is used. The detectors are connected in the order of MALLS, RI, and Viscometer. The mobile phase solvent was 1,2,4-trichlorobenzene (to which the antioxidant Irganox 1076 manufactured by BASF Japan was added at a concentration of 0.5 mg/mL).

The flow rate of the mobile phase solvent was 1 mL/min, and the columns used were two GMHHR-H(S) HT manufactured by Tosoh Corporation connected together. The temperature of the column, sample injection section, and each detector was 140°C. The sample concentration is 1 mg/mL, and the injection volume (sample loop volume) is 0.2175 mL.

To calculate the absolute molecular weight (Mabs), root mean square radius of inertia (Rg), and intrinsic viscosity ([η]), use the data processing software ASTRA (version 4.73.04) included with MALLS, and refer to the following literature. Perform the calculation.
References 1. Developments in Polymer Characterization-4 (J.V. Dawkins ed. Applied Science Publishers, 1983. Chapter 1.)
Reference 2. Polymer, 45, 6495-6505 (2004)
Reference 3. Macromolecules, 33, 2424-2436 (2000)
Reference 4. Macromolecules, 33, 6945-6952 (2000)

The branching index g' is the ratio ([η]lin) of the intrinsic viscosity ([η]br) obtained by measuring the sample with a Viscometer and the intrinsic viscosity ([η]lin) obtained by separately measuring the linear polymer. ]br/[η]lin).

Here, as the linear polymer for obtaining [η]lin, commercially available homopolypropylene (Novatec (registered trademark) PP grade name: FY6, manufactured by Nippon Polypropylene Co., Ltd.) is used. It is known as the Mark-Houwink-Sakurada equation that the logarithm of [η]lin of a linear polymer has a linear relationship with the logarithm of the molecular weight. You can extrapolate to get a numerical value.

The polypropylene resin (A1) preferably has a strain hardening degree (λmax (0.1)) of 6.0 or more, more preferably 8.0 or more as measured by extensional viscosity at a strain rate of 0.1 s ⁻¹ .
The degree of strain hardening (λmax (0.1)) is an index representing the strength at the time of melting, and when this value is large, there is an effect of improving the melt tension. As a result, during thermoforming, it is possible to prevent defective phenomena such as the formation of excessively uneven thickness even in molded products with complex shapes, improve the physical properties of the molded product, and reduce the thickness of the original sheet. Since it contributes to thinning (gauge down), industrial parts such as automobile parts can be suitably molded. When the strain hardening degree of the polypropylene resin (A1) having a long chain branched structure is 6.0 or more, a sufficient thickness unevenness suppressing effect is exhibited. Moreover, when the degree of strain hardening is 8.0 or more, even when the amount of filler and the amount of thermoplastic elastomer are increased, a sufficient thickness unevenness suppressing effect is exhibited.

The method for calculating the strain hardening degree λmax (0.1) in measuring the extensional viscosity at a strain rate of 0.1 s ⁻¹ is described below.
The elongational viscosity at a temperature of 180° C. and a strain rate of 0.1 s ⁻¹ is plotted on a log-log graph with time t (seconds) on the horizontal axis and elongational viscosity ηE (Pa·seconds) on the vertical axis. The relationship between the time immediately before strain hardening and viscosity is approximated by a straight line on the double-logarithmic graph to obtain an approximate straight line.
Specifically, first, the slope at each time when the extensional viscosity is plotted against time is determined. Use the average method. For example, a method may be used in which the slopes of adjacent data are respectively determined and the moving average of several surrounding points is taken.

In the region of low strain, the extensional viscosity becomes a simple increasing function, gradually approaches a constant value, and if there is no strain hardening, it will match the Trouton viscosity after a sufficient period of time has passed, but if there is strain hardening, the From a strain amount (=strain rate x time) of about 1, the elongational viscosity begins to increase with time. In other words, the above slope tends to decrease with time in the low strain region, but it tends to increase from a strain amount of about 1, and there is an inflection point on the curve when the extensional viscosity is plotted against time. . Therefore, within the distortion amount range of about 0.1 to 2.5, find the point where the slope at each time found above takes the minimum value, draw a tangent at that point, and draw a straight line with a distortion amount of 4.0. Extrapolate until . The maximum value (ηmax) of the elongational viscosity ηE until the strain amount reaches 4.0 and the time at which the maximum value is reached are determined, and the viscosity on the approximate straight line at that time is defined as ηlin. ηmax/ηlin is defined as λmax(0.1).

Polypropylene resin (A1) is a propylene homopolymer obtained by homopolymerizing propylene in a single-stage polymerization or a multi-stage polymerization of two or more stages, or a propylene homopolymer obtained by copolymerizing propylene with an α-olefin in a single-stage polymerization or a multi-stage polymerization of two or more stages. Propylene/α-olefin random copolymer obtained by polymerization, polymerization step (1) of homopolymerizing propylene by single-stage polymerization or multi-stage polymerization of two or more stages to obtain a propylene homopolymer, and propylene and α-olefin Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing by single-stage polymerization or multi-stage polymerization of two or more stages, or single-stage polymerization or two-stage polymerization of two or more α-olefins. A propylene/α-olefin block copolymer obtained by polymerization including the copolymerization step (2-2) to obtain a random copolymer between α-olefins by copolymerizing in the above multistage polymerization, propylene and α-olefin. A copolymerization step (1) to obtain a propylene/α-olefin random copolymer obtained by copolymerizing in a single-stage polymerization or a multi-stage polymerization of two or more stages, and a copolymerization step (1) in which propylene and α-olefin are copolymerized in a single-stage polymerization or a multi-stage polymerization of two or more stages. Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing in multi-stage polymerization, or copolymerizing two or more α-olefins in single-stage polymerization or multi-stage polymerization of two or more stages. Examples include a propylene/α-olefin random block copolymer obtained by polymerization including a copolymerization step (2-2) for obtaining a random copolymer between α-olefins. Moreover, as the polypropylene resin (A1), one type or a combination of two or more types may be used.

The α-olefin is preferably ethylene or an α-olefin having 4 to 18 carbon atoms. Specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene- I can list the first prize. Furthermore, the α-olefin may be used alone or in combination of two or more.

The polypropylene resin (A1) is preferably one or more polypropylene resins selected from the group consisting of propylene homopolymer, propylene/ethylene block copolymer, and propylene/ethylene/1-butene block copolymer. .

Examples of the polypropylene resin (A1) include those polymerized using a Ziegler-Natta catalyst, those polymerized using a metallocene catalyst, and those polymerized using a post-metallocene catalyst. Examples of the Ziegler-Natta catalyst include catalysts containing solid components including titanium, magnesium, and halogen, organic aluminum, and an electron donor used as necessary. Examples of the metallocene catalyst include a transition metal compound of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, and a catalyst containing an organometallic compound and a carrier used as necessary. It will be done. Examples of the post-metallocene catalyst include organometallic compounds such as bisamide compounds of metals of group 4 of the periodic table, bisimino compounds of metals of groups 8 to 10 of the periodic table, salicylaldiminato compounds of metals of groups 4 to 10 of the periodic table, promoters, and catalysts containing organometallic compounds and carriers used as necessary.
As the polypropylene resin (A1), commercially available products can be used, such as WAYMAX (registered trademark) series manufactured by Nippon Polypropylene Co., Ltd., and the like.

Polypropylene resin (A2)
The polypropylene resin (A2) preferably has a melting point of 150°C or higher, more preferably 153°C or higher, even more preferably 155°C or higher. The melting point of the polypropylene resin (A2) is preferably 170°C or lower. By setting the melting point of the polypropylene resin (A2) to 150°C or higher, the rigidity and heat resistance are increased. Furthermore, the melting point can be adjusted by adjusting the amount of comonomers such as ethylene and butene introduced during propylene polymerization.

The polypropylene resin (A2) has a melt flow rate (MFR) measured at 230° C. and a load of 2.16 kg, preferably from 0.1 to 150 g/10 minutes, more preferably from 1 to 100 g/10 minutes. Here, MFR is a value measured at 230° C. and a load of 2.16 kg in accordance with JIS K7210. The MFR of the polypropylene resin (A2) can be adjusted by controlling the hydrogen concentration during polymerization. When the MFR is 0.1 g/10 minutes or more, the load on the extruder is suppressed during extrusion molding of the sheet, and productivity is improved, which is preferable.

The polypropylene resin (A2) has the following characteristic (a-2) regarding the relationship between melt tension and MFR.
Characteristic (a-2): Melt tension (MT) (unit: g) satisfies log(MT)<-0.9×log(MFR)+0.7 and log(MT)<1.15

The melt tension (MT) of the polypropylene resin (A2) preferably satisfies log(MT)<-0.9×log(MFR)+0.6 and log(MT)<1.04 (MT<11). , more preferably satisfies log(MT)<−0.9×log(MFR)+0.5 and log(MT)<0.85 (MT<7).

There is no set lower limit for the melt tension of the polypropylene resin (A2), but if it is too small, the drawdown resistance may decrease and the moldable temperature range during thermoforming may be narrowed, so it is preferably log (MT )>0.48 (MT>3).

The polypropylene resin (A2) preferably has a Q value (Mw/Mn) of 3.5 to 10 determined from the weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography (GPC). , more preferably 3.7 to 8, still more preferably 4 to 6. When the Q value of the polypropylene resin (A2) is within the above range, the molding processability is particularly excellent when extrusion molding a sheet, which is preferable.

The polypropylene resin (A2) preferably has a long chain branched structure.
The polypropylene resin (A2) preferably has a branching index g' of 1 when the absolute molecular weight Mabs determined by a light scattering meter is 1 million.

Polypropylene resin (A2) is a propylene homopolymer obtained by homopolymerizing propylene in a single-stage polymerization or a multi-stage polymerization of two or more stages, or a propylene homopolymer obtained by copolymerizing propylene with an α-olefin in a single-stage polymerization or a multi-stage polymerization of two or more stages. Propylene/α-olefin random copolymer obtained by polymerization, polymerization step (1) of homopolymerizing propylene by single-stage polymerization or multi-stage polymerization of two or more stages to obtain a propylene homopolymer, and propylene and α-olefin Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing by single-stage polymerization or multi-stage polymerization of two or more stages, or single-stage polymerization or two-stage polymerization of two or more α-olefins. A propylene/α-olefin block copolymer obtained by polymerization including the copolymerization step (2-2) to obtain a random copolymer between α-olefins by copolymerizing in the above multistage polymerization, propylene and α-olefin. A copolymerization step (1) to obtain a propylene/α-olefin random copolymer obtained by copolymerizing in a single-stage polymerization or a multi-stage polymerization of two or more stages, and a copolymerization step (1) in which propylene and α-olefin are copolymerized in a single-stage polymerization or a multi-stage polymerization of two or more stages. Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing in multi-stage polymerization, or copolymerizing two or more α-olefins in single-stage polymerization or multi-stage polymerization of two or more stages. Examples include a propylene/α-olefin random block copolymer obtained by polymerization including a copolymerization step (2-2) for obtaining a random copolymer between α-olefins. Furthermore, the polypropylene resin (A2) may be used alone or in combination of two or more.

The α-olefin is preferably ethylene or an α-olefin having 4 to 18 carbon atoms. Specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene- I can list the first prize. Furthermore, the α-olefin may be used alone or in combination of two or more.

The polypropylene resin (A2) is preferably one or more polypropylene resins selected from the group consisting of propylene homopolymer, propylene/ethylene block copolymer, and propylene/ethylene/1-butene block copolymer. .

Examples of the polypropylene resin (A2) include those polymerized using a Ziegler-Natta catalyst, those polymerized using a metallocene catalyst, and those polymerized using a post-metallocene catalyst. Examples of the Ziegler-Natta catalyst include catalysts containing solid components including titanium, magnesium, and halogen, organic aluminum, and an electron donor used as necessary. Examples of the metallocene catalyst include a transition metal compound of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, and a catalyst containing an organometallic compound and a carrier used as necessary. It will be done. Examples of the post-metallocene catalyst include organometallic compounds such as bisamide compounds of metals of group 4 of the periodic table, bisimino compounds of metals of groups 8 to 10 of the periodic table, salicylaldiminato compounds of metals of groups 4 to 10 of the periodic table, promoters, and catalysts containing organometallic compounds and carriers used as necessary.
A commercially available product can be used as the polypropylene resin (A2), and for example, Novatec (registered trademark) PP series manufactured by Nippon Polypropylene Co., Ltd. can be used.

The second polypropylene resin composition of the present invention is an embodiment containing a polypropylene resin (A1) and a polypropylene resin (A2), and the mass ratio of the polypropylene resin (A1) and the polypropylene resin (A2) is, for example, preferably Polypropylene resin (A1): polypropylene resin (A2) = 5:95 to 95:5, more preferably polypropylene resin (A1): polypropylene resin (A2) = 10:90 to 85:15, even more preferably polypropylene resin (A1) ): polypropylene resin (A2) = 15:85 to 70:30.

The second polypropylene resin composition of the present invention is an embodiment containing a polypropylene resin (A1) and a polypropylene resin (A2), and the melting point (Tm1/°C) of the polypropylene resin (A1) and the melting point of the polypropylene resin (A2) (Tm2/°C) preferably satisfies Tm2-Tm1≧1, more preferably satisfies Tm2-Tm1≧3, and still more preferably satisfies 10≧Tm2-Tm1≧3.

Polypropylene resin (B)
The polypropylene resin (B) has a melting point of 110 to 150°C, preferably 115 to 145°C, more preferably 120 to 140°C. By setting the melting point of the polypropylene resin (B) to 110° C. or higher, it becomes possible to reduce stickiness caused by low crystallinity components. In addition, by setting the melting point of the polypropylene resin (B) to less than 150°C, the temperature when molding the polypropylene resin composition can be relatively low, suppressing the generation of odor, and improving moldability and product quality. Quality can be ensured. The melting point can be adjusted by adjusting the amount of comonomers such as ethylene and butene introduced during propylene polymerization, similarly to the polypropylene resin (A1). Here, the melting point is a value measured by the same method as measuring the melting point of the polypropylene resin (A1).

The melt flow rate (MFR) of the polypropylene resin (B) measured at 230° C. and a load of 2.16 kg is preferably 0.1 to 150 g/10 minutes, more preferably 1 to 100 g/10 minutes. When MFR is 0.1 g/10 minutes or more, when extruding a sheet, the load on the extruder is suppressed and productivity is improved. Here, MFR is a value measured at 230° C. and a load of 2.16 kg in accordance with JIS K7210. The MFR of the polypropylene resin (B) can be adjusted by controlling the hydrogen concentration during polymerization, etc.

The MFR of the polypropylene resin (B) preferably satisfies the following relationship. That is, when the melt flow rate of the polypropylene resin (A) is MFRa and the melt flow rate of the polypropylene resin (B) is MFRb, MFRa/MFRb preferably satisfies 30>MFRa/MFRb>1, more preferably 15> MFRa/MFRb>1.5 is satisfied. When MFRa/MFRb is within the above value range, a molded article with smaller thickness deviation can be obtained.

The polypropylene resin (B) preferably has a relationship between melt flow rate (MFR) and melt tension (MT) (unit: g) such that log(MT)<-0.9×log(MFR)+0.7. and log(MT)<1.15, more preferably log(MT)<-0.9×log(MFR)+0.6, and log(MT)<1.04 (MT<11). , more preferably satisfies log(MT)<−0.9×log(MFR)+0.5 and log(MT)<0.85 (MT<7).

There is no set lower limit for the melt tension of the polypropylene resin (B), but if it is too small, the drawdown resistance may decrease and the moldable temperature range during thermoforming may be narrowed, so it is preferably log (MT )>0.48 (MT>3). Here, the melt tension (MT) is a value measured by the same method as for measuring the melt tension of the polypropylene resin (A1).

(b-1) Q value The polypropylene resin (B) preferably has a Q value of 5.0 or less, more preferably 2.0 to 4.0, and even more preferably 2.3 to 3.5. Yes, and even more preferably 2.6 to 3.3. Here, the Q value is defined by the ratio (Mw/Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by GPC. By setting the Q value of the polypropylene resin (B) to 5.0 or less, a molded article with excellent mechanical properties can be obtained, which is preferable.

(b-2) Amount soluble at 40°C or less as measured by temperature-rising elution fractionation (TREF) method Polypropylene resin (B) is soluble in orthodichlorobenzene at 40°C or less as measured by temperature-rising elution fractionation (TREF) method. The amount of soluble components is preferably 4.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.5% by mass or less. By keeping the amount of soluble matter below 40°C measured by temperature-rising elution fractionation (TREF) method to 4.0% by mass or less, it improves compatibility with the biomass material (C) and suppresses bleeding from the molded product. And it is preferable.

Components that are soluble in orthodichlorobenzene at 40°C include components with low molecular weight such as oligomers, components with low stereoregularity such as atactic polypropylene, components with extremely high comonomer content, and so-called low crystal components. . Here, components with low stereoregularity such as atactic polypropylene and low crystallinity components with an extremely high comonomer content can become soluble components even if they have a high molecular weight. Therefore, in order to obtain the polypropylene resin (B) preferably used in the present invention, polypropylene with low stereoregularity and a polypropylene with a wide composition distribution that includes a low crystallinity component with an extremely high comonomer content is obtained. The use of catalysts and polymerization methods should be avoided.

Here, the amount of the component soluble in orthodichlorobenzene at 40° C. or lower measured by the temperature rising elution fractionation (TREF) method is a value measured according to the following procedure.
The sample is dissolved in orthodichlorobenzene at 140°C to form a solution. This was introduced into a TREF column at 140°C under the following conditions, cooled to 100°C at a cooling rate of 8°C/min, and then cooled to 40°C at a cooling rate of 4°C/min, and held for 10 minutes. . Thereafter, the solvent orthodichlorobenzene was flowed through the column at a flow rate of 1 mL/min to elute the components dissolved in orthodichlorobenzene at 40°C in the TREF column for 10 minutes, and then the temperature was increased at a rate of 100°C/hour. The temperature of the column was raised linearly to 140° C. to obtain an elution curve.
Column size: 4.3mmφ x 150mm
Column packing material: 100μm surface-deactivated glass beads Solvent: Orthodichlorobenzene Sample concentration: 5mg/mL
Sample injection volume: 0.2mL
Solvent flow rate: 1 mL/min Detector: Fixed wavelength infrared detector MIRAN 1A manufactured by FOXBORO
Measurement wavelength: 3.42μm
From the elution curve obtained according to the above conditions, the ratio (mass %) of the amount of the component eluted at 40° C. to the total amount of the sample is calculated.

Polypropylene resin (B) is a propylene homopolymer obtained by homopolymerizing propylene in a single-stage polymerization or a multi-stage polymerization of two or more stages, or a propylene homopolymer obtained by copolymerizing propylene with a single-stage polymerization or a multi-stage polymerization of two or more stages. Propylene/α-olefin random copolymer obtained by polymerization, polymerization step (1) of homopolymerizing propylene by single-stage polymerization or multi-stage polymerization of two or more stages to obtain a propylene homopolymer, and propylene and α-olefin Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing by single-stage polymerization or multi-stage polymerization of two or more stages, or single-stage polymerization or two-stage polymerization of two or more α-olefins. A propylene/α-olefin block copolymer obtained by polymerization including the copolymerization step (2-2) to obtain a random copolymer between α-olefins by copolymerizing in the above multistage polymerization, propylene and α-olefin. A copolymerization step (1) to obtain a propylene/α-olefin random copolymer obtained by copolymerizing in a single-stage polymerization or a multi-stage polymerization of two or more stages, and a copolymerization step (1) in which propylene and α-olefin are copolymerized in a single-stage polymerization or a multi-stage polymerization of two or more stages. Copolymerization step (2-1) to obtain a propylene/α-olefin random copolymer by copolymerizing in multi-stage polymerization, or copolymerizing two or more α-olefins in single-stage polymerization or multi-stage polymerization of two or more stages. Examples include a propylene/α-olefin random block copolymer obtained by polymerization including a copolymerization step (2-2) for obtaining a random copolymer between α-olefins. Furthermore, the polypropylene resin (B) may be used alone or in combination of two or more.

The α-olefin is preferably ethylene or an α-olefin having 4 to 18 carbon atoms. Specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene- I can list the first prize. Furthermore, the α-olefin may be used alone or in combination of two or more.

The polypropylene resin (B) is a propylene/ethylene random copolymer, a propylene/1-butene random copolymer, a propylene/ethylene/1-butene random copolymer, a propylene/ethylene random block copolymer, a propylene/ethylene/ It is preferable to use one or more polypropylene resins selected from the group consisting of 1-butene random block copolymers.

The polypropylene resin (B) contains 85 to 100 mol% of propylene units, preferably 90 to 99.5 mol%, more preferably 92 to 98.5 mol%, and 0 to 15 mol% of ethylene units and/or 1-butene units. It contains mol%, preferably 0.5 to 10 mol%, more preferably 1.5 to 8 mol%.
Here, the propylene unit and ethylene and/or 1-butene unit are values measured by Fourier transform infrared analysis.

Examples of the polypropylene resin (B) include those polymerized using a Ziegler-Natta catalyst, those polymerized using a metallocene catalyst, and those polymerized using a post-metallocene catalyst. Examples of the Ziegler-Natta catalyst include catalysts containing solid components including titanium, magnesium, and halogen, organic aluminum, and an electron donor used as necessary. Examples of the metallocene catalyst include a transition metal compound of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, and a catalyst containing an organometallic compound and a carrier used as necessary. It will be done. Examples of the post-metallocene catalyst include organometallic compounds such as bisamide compounds of metals of group 4 of the periodic table, bisimino compounds of metals of groups 8 to 10 of the periodic table, salicylaldiminato compounds of metals of groups 4 to 10 of the periodic table, promoters, and catalysts containing organometallic compounds and carriers used as necessary.
As the polypropylene resin (B), commercially available products can be used, such as the WINTEC (registered trademark) series manufactured by Nippon Polypropylene Co., Ltd., and the like.

Biomass material (C)
The biomass material (C) is an organic resource derived from animals and plants, excluding fossil resources, and preferably an organic resource derived from plants, excluding fossil resources. Examples of plant-derived organic resources excluding fossil resources include cellulose materials, lignocellulose materials, starch materials, and the like.

Examples of cellulosic materials include alpha fiber flock obtained by treating wood pulp with alkali and mechanically shredding it, cotton linter obtained from cotton seeds, cotton flock, and human silk flock obtained by shredding human silk. Lignocellulosic materials include lignocellulosic fibers and lignocellulosic powders. Specific examples include wood pulp, refiner graft pulp (RGP), paper pulp, waste paper, pulverized wood chips, wood flour, and fruit shell powder. The shape of these cellulosic materials and lignocellulosic materials is not particularly limited, and fibrous or powdered materials can be used. Specific examples of wood powder include crushed materials such as pine, fir, poplar, bamboo, bagasse, and oil palm tree trunks, sawdust, and canna shavings, and fruit shell powder includes fruits such as walnuts, peanuts, and coconut. There is a crushed material.

Cellulosic materials or lignocellulosic materials are esterified cellulose materials or esterified lignocellulosic materials, cellulosic materials, or lignocellulosic materials in which polybasic acid anhydrides are added to the hydroxyl groups of cellulosic materials or lignocellulosic materials. An oligoesterified cellulosic material or an oligoesterified lignocellulosic material obtained by adding a polybasic acid anhydride and a monoepoxy compound to the hydroxyl group of the cellulose material, and a hydroxyl group of the cellulosic material or lignocellulosic material, It may be an oligoesterified cellulose material or an oligoesterified lignocellulose material to which a polybasic acid anhydride and a polyhydric alcohol are added.

Examples of polybasic acid anhydrides include maleic anhydride, succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, dichloromaleic anhydride, itaconic anhydride, tetrabromophthalic anhydride, het's acid anhydride, Trimetic anhydride, pyromellitic anhydride, etc. may be mentioned, but maleic anhydride, succinic anhydride, and phthalic anhydride are particularly preferred, as they are industrially advantageous and inexpensive.

The monoepoxy compound may be any compound containing one epoxy group in the molecule, such as phenyl glycidyl ether, allyl glycidyl ether, styrene oxide, octylene oxide, methyl glycidyl ether, butyl glycidyl ether, cresyl Examples include glycidyl ether.

Examples of polyhydric alcohols include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-octanediol. , 1,9-nonanediol, 1,10-decanediol, pinacol, hydrobenzoin, benzpinacol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, glycerin, Examples include polyethylene glycol 400.

A general method for carrying out esterification is to use the polybasic acid anhydride (or the polybasic acid anhydride and the monoepoxy compound, or the polybasic acid anhydride and the monoepoxy compound, or the polybasic acid anhydride and the monoepoxy compound, or the polybasic acid anhydride and the monoepoxy compound, or the polybasic acid anhydride and the monoepoxy compound, or the polybasic acid anhydride and the monoepoxy compound, or and the polyhydric alcohol) and reacted at a temperature of 60 to 150°C for 0.5 to 8 hours.

In the case of a reaction in which the polybasic acid anhydride and the monoepoxy compound are alternately added and esterified to the hydroxyl group in the cellulosic material or lignocellulosic material component, the reaction proceeds satisfactorily even in the absence of a catalyst, but the reaction may be accelerated. For this purpose, a basic catalyst such as sodium carbonate, dimethylbenzylamine, tetramethylammonium chloride, or pyridine may be used. Additionally, addition esterification catalysts may be used.

The molecular weight of the oligomer of the polybasic acid anhydride and the monoepoxy compound is about 20 to 1,000 so that it can be liquid (the degree of polymerization is preferably 5 or less, and the molecular weight is 1). ) is preferable.

Further, the blending amounts of the polybasic acid anhydride and the monoepoxy compound are as follows. First, the polybasic acid anhydride is used in an amount of 5 to 120 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the dry cellulosic material or lignocellulosic material. The monoepoxy compound preferably has an epoxy group of 0.5 to 2.0 equivalents per equivalent of anhydride group of the polybasic acid anhydride used. This is because when the polybasic acid anhydride is used in an amount greater than 120 parts by mass per 100 parts by mass of dry cellulosic material or lignocellulosic material, the content of the lignocellulosic or cellulosic material component becomes low, and the heat pressure This is undesirable because it causes oozing during molding, and if the amount is less than 5 parts by mass, the hot-pressure fluidity decreases, and furthermore, it becomes impossible to obtain a uniform molded product, which is undesirable.

In the case of a reaction in which the polybasic acid anhydride and the polyhydric alcohol are alternately added and esterified to the hydroxyl group of the cellulosic material or lignocellulose material, the monoepoxy compound described above may be replaced with the polyhydric alcohol. .

As specific examples of starch-based materials, for example, rice, wheat, corn, sugarcane, potato, sweet potato, tapioca, corn starch, potato starch, potato starch, tapioca starch, and lightly acetylated products thereof can be widely used. Any agricultural products containing starch can be used without being limited to these. In addition, these starch-based materials may be kept in their general state when stockpiled, or they may be processed through simple processes such as washing, removing non-starchy parts such as the outer skin, or cutting them into appropriate sizes. It can be used as long as it is pretreated. Starch-based materials are usually obtained in the form of granules, but these can be used as they are.

Further, it is more preferable that the starch material used as a raw material is subjected to such a simple pretreatment and then subjected to a gelatinization treatment as described below. In other words, the starch that makes up starch-based materials initially has a crystalline structure (β structure), but when placed in a temperature environment of 70°C or higher in the presence of an appropriate amount of moisture, this β structure collapses. It changes to an amorphous structure (α structure). When raw starch contains water and is heated, it changes from the β structure to the α structure, which is called gelatinization. Starch granules exhibiting an α structure in this gelatinized material are dissolved at the starch molecular level in the heat-flowing polypropylene resin, compared to the β structure in the initial heated state (raw state). It becomes easy to disperse finely and uniformly.

As a specific process for converting starch having a β structure into an α structure, heat treatment that is generally used when making it edible, such as immersing it in water and boiling it, or steaming it with steam, is added. There are several methods.

By the way, if starch, which has an amorphous α structure, is left at low temperatures while still containing moisture, a phenomenon (called aging) is observed in which it returns to its original crystalline state of a β structure over time. generally known. On the other hand, it is known that if water is removed from starch, which has an amorphous α structure, the starch will maintain its α structure and will not undergo a reversible transition to a β structure (no aging) even if it is left at low temperatures for a long period of time. There is.

Therefore, the starch-based material used as the raw material of the present invention has an α structure (amorphous structure), and can be used in both a water-containing state and a water-free (dehydrated) state. This shall also include. In any case, if the starch structure of the starch-based material blended into the polypropylene resin is an α structure (amorphous structure), the molecular chains of starch will be loosened in the matrix of the polypropylene resin during the kneading process described later. , it becomes finer and more easily dispersed. This is an effect that cannot be obtained when a non-heated starch material whose starch structure is a β structure (crystalline structure) is blended.

By the way, the method for obtaining a dehydrated starch material having an α structure is to heat it in the presence of moisture to gelatinize it, and then directly reduce the pressure of the atmosphere using a vacuum device. If such dehydrated α-structure starch materials are used, they will not age easily, making it possible to store the starch materials alone for a long period of time, thereby shortening the production period and improving the production time of polypropylene resin compositions. This will contribute to cost reduction.

It is assumed that trehalose is dissolved in the water used for converting the starch having the β structure into the α structure. The effect of this is, for example, when rice is used as a starch-based material, by impregnating the uncooked rice with a trehalose aqueous solution, trehalose has the effect of suppressing the decomposition of the lipid components of rice, and the production process is improved. The purpose is to suppress deterioration over time of a polypropylene resin composition using rice. The reason for this is said to be that trehalose has the effect of coating rice components and protecting fatty acids from oxidative decomposition.

It can be said that this effect is not limited to rice but is also exhibited in general starch-based materials, and in addition to the above-mentioned trehalose, salt, sucrose, and antioxidants have such an effect. agents, protein decomposition promoters, cellulose decomposition promoters, and the like. In addition, by adding these materials to water to form a starch material having an α structure, it is possible to obtain the effect of preventing the characteristic odor, burning, and discoloration of the produced polypropylene resin composition.

So far, we have explained the use of starch materials that have already been subjected to gelatinization treatment to be blended as raw materials, but by the production method described later, starch materials with a β structure that contain water can be used. It can also be used in cases.

Specifically, raw rice is immersed in water for a predetermined period of time, drained, and then put into a kneader together with a polypropylene resin and kneaded at the heat flow temperature of the polypropylene resin. This heat flow temperature (usually 100 to 170°C) is sufficient to transform the starch structure of raw rice from β structure to α structure, so raw rice is gelatinized during the kneading process. become. In this way, after the raw rice changes to the α structure, the starch molecular chains loosen, become finer, and are dispersed in the polypropylene resin matrix, as described above.

Here, in order for raw rice with a β structure to become a gelatinized structure by heating, it is desirable that the moisture content be 17% or more by mass, and for this purpose, the immersion time in water should be 5 minutes or more. There is a need to. In addition, starch-based materials such as potatoes, which contain enough water to convert starch into an alpha structure by themselves, do not need to be soaked in water like rice, and can be fed directly into the kneading machine. can.

The biomass material (C) is preferably one or more plant-derived fillers selected from the group consisting of wood, pulp, bamboo, sugarcane (bagasse), rice husk, and rice (starch).

The first polypropylene resin composition of the present invention preferably contains 5 to 85% by mass of polypropylene resin (A1), 5 to 85% by mass of polypropylene resin (B), and 10 to 80% by mass of biomass material (C). Contains 10 to 75% by mass of polypropylene resin (A1), 10 to 75% by mass of polypropylene resin (B), and 15 to 70% by mass of biomass material (C), more preferably 15 to 65% by mass of polypropylene resin (A1), Contains 15 to 65% by mass of polypropylene resin (B), and 20 to 60% by mass of biomass material (C), more preferably 20 to 55% by mass of polypropylene resin (A1), 20 to 55% by mass of polypropylene resin (B), and 25 to 55% by mass of biomass material (C). Here, the total mass proportion of (A1), (B) and (C) is 100% by mass.

The second polypropylene resin composition of the present invention contains a total of 5 to 85% by mass of polypropylene resin (A1) and polypropylene resin (A2), 5 to 85% by mass of polypropylene resin (B), and 10 to 85% by mass of biomass material (C). 80% by mass, preferably a total of 10 to 75% by mass of polypropylene resin (A1) and polypropylene resin (A2), 10 to 75% by mass of polypropylene resin (B), and 15 to 70% by mass of biomass material (C). more preferably a total of 15 to 65% by mass of polypropylene resin (A1) and polypropylene resin (A2), 15 to 65% by mass of polypropylene resin (B), and 20 to 60% by mass of biomass material (C), and further It preferably contains a total of 20 to 55% by mass of polypropylene resin (A1) and polypropylene resin (A2), 20 to 55% by mass of polypropylene resin (B), and 25 to 55% by mass of biomass material (C). Here, the total mass proportion of (A1), (A2), (B) and (C) is 100% by mass.

Thermoplastic elastomer (D)
Optionally, a thermoplastic elastomer (D) may be blended into the polypropylene resin composition. Examples of the thermoplastic elastomer (D) include olefin elastomers and styrene elastomers. These can be used alone or in combination of two or more.

Examples of olefin elastomers include ethylene/propylene copolymer elastomer (EPR), ethylene/butene copolymer elastomer (EBR), ethylene/hexene copolymer elastomer (EHR), and ethylene/octene copolymer elastomer (EOR). ), ethylene/α-olefin/diene ternary copolymer elastomers such as ethylene/propylene/ethylidene norbornene copolymer, ethylene/propylene/butadiene copolymer, ethylene/propylene/isoprene copolymer, ethylene/ethylene/butylene - Hydrogenated polymer elastomers such as ethylene copolymer (CEBC) can be mentioned. Among these, ethylene/propylene copolymer elastomer, ethylene/butene copolymer elastomer, and ethylene/hexene copolymer elastomer are preferred.

Examples of styrene-based elastomers include styrene-butadiene-styrene triblock copolymer elastomer (SBS), styrene-isoprene-styrene triblock copolymer elastomer (SIS), and styrene-ethylene-butylene copolymer elastomer (SEB). , styrene-ethylene/propylene copolymer elastomer (SEP), styrene-ethylene/butylene-styrene copolymer elastomer (SEBS), styrene-ethylene/butylene-ethylene copolymer elastomer (SEBC), hydrogenated styrene/butadiene elastomer (HSBR), styrene-ethylene/propylene-styrene copolymer elastomer (SEPS), styrene-ethylene/ethylene/propylene-styrene copolymer elastomer (SEEPS), styrene-butadiene/butylene-styrene copolymer elastomer (SBBS) , partially hydrogenated styrene-isoprene-styrene copolymer elastomer, partially hydrogenated styrene-isoprene-butadiene-styrene copolymer elastomer, and the like.

The thermoplastic elastomer (D) preferably has an MFR of 0.01 to 10 g/10 minutes, more preferably 0.1 to 3 g/10 minutes, as measured at 190° C. and a load of 2.16 kg. When the MFR of the thermoplastic elastomer (D) is 0.1 g/10 minutes or more, when extruding a sheet, the load on the extruder is suppressed and productivity is improved. Further, it is preferable that the MFR is 10 g/10 minutes or less because the melt tension of the sheet can be kept high and the molded product will not sag due to its own weight during extrusion molding or thermoforming.

The polypropylene resin composition of the present invention is the sum of polypropylene resin (A1), polypropylene resin (B) and biomass material (C), or the sum of polypropylene resin (A1), polypropylene resin (A2), polypropylene resin (B) and biomass material Preferably the thermoplastic elastomer (D) is 1 to 50 parts by weight, more preferably 2 to 44 parts by weight, even more preferably 4 to 38 parts by weight, and More preferably, it can contain 8 to 32 parts by mass.

(3) Compatibilizer A compatibilizer may be added to the polypropylene resin composition, if necessary. Preferably used compatibilizers include saturated carboxylic acids, unsaturated carboxylic acids or derivatives thereof, thermoplastic resins modified with unsaturated carboxylic acids or derivatives thereof, and thermoplastic resins modified with unsaturated carboxylic acids or derivatives thereof. Examples include cellulose materials, lignocellulose materials, starch materials, and the like. Furthermore, oil-modified alkyd resins or derivatives thereof, modified starches or derivatives thereof can also be used.

Examples of the saturated carboxylic acid include succinic anhydride, succinic acid, phthalic anhydride, phthalic acid, tetrahydrophthalic anhydride, adipic anhydride, and the like. Examples of unsaturated carboxylic acids include maleic anhydride, maleic acid, nadic anhydride, itaconic anhydride, itaconic acid, citraconic anhydride, citraconic acid, crotonic acid, isocrotonic acid, mesaconic acid, angelic acid, sorbic acid, acrylic acid, etc. can be mentioned. As the derivative of saturated carboxylic acid or unsaturated carboxylic acid, metal salts, amides, imides, esters, etc. of saturated carboxylic acid or unsaturated carboxylic acid can be used.

Furthermore, thermoplastic resins modified with unsaturated carboxylic acids or derivatives thereof, cellulosic materials, lignocellulosic materials, starch materials, etc. modified with unsaturated carboxylic acids or derivatives thereof can be used. The thermoplastic resin before modification used in the thermoplastic resin modified with an unsaturated carboxylic acid or its derivative is not particularly limited as long as it does not significantly impair the effects of the present invention, and specifically, low density polyethylene, Examples include ethylene-α-olefin copolymer, high-density polyethylene, polypropylene, propylene block copolymer, and propylene random copolymer. Among these, it is preferable that the resin is the same as polypropylene resin (A1), polypropylene resin (A2) and/or polypropylene resin (B).

These can be obtained by heating and mixing thermoplastic resins, cellulosic materials, lignocellulosic materials, starch materials, etc., unsaturated carboxylic acids or derivatives thereof, and radical generators in the presence or absence of a solvent. It will be done. The amount of unsaturated carboxylic acid or its derivative added is preferably 0.1 to 15% by weight, particularly preferably 1 to 10% by weight. Compatibilizers used in the present invention include thermoplastic resins modified with unsaturated carboxylic acids or derivatives thereof that have no odor and low acidity, cellulosic materials modified with unsaturated carboxylic acids or derivatives thereof, and lignosols. Cellulose-based materials, starch-based materials, etc. are preferred.

The polypropylene resin composition may optionally contain various additives, such as nucleating agents, heat stabilizers, antioxidants, weather stabilizers, and light stabilizers, as long as the effects of the present invention are not significantly impaired. Stabilizers, UV absorbers, antistatic agents, slip agents, anti-blocking agents, antifogging agents, neutralizing agents, metal deactivators, surfactants, compatibilizers, colorants, antibacterial/antifungal agents, flame retardants , plasticizers, dispersants, fillers, conductive agents, preservatives, fragrances, deodorants, insect repellents, elastomers, etc. Two or more of these optional components may be used in combination.
In addition, these optional components may be blended with the polypropylene resin (A1) and/or the polypropylene resin (A2), or may be blended with the polypropylene resin (B), and in each resin component, Two or more types can also be used together.

The method for preparing the propylene resin composition of the present invention includes dry blending of powdered or pelleted polypropylene resin (A), polypropylene resin (B), biomass material (C), and other compounding agents used as necessary. A method of mixing using a Henschel mixer or the like can be mentioned. In an embodiment in which the polypropylene resin (A) contains the polypropylene resin (A1) and the polypropylene resin (A2), the polypropylene resin (A1) and the polypropylene resin (A2) may be mixed in advance, or the polypropylene resin (B) and It may be mixed together with the biomass material (C). Further, depending on the situation, the biomass material (C) and the polypropylene resin (A) and/or the polypropylene resin (B) may be fixed in advance by a gelation method or the like. Alternatively, these may be kneaded using a single-screw or twin-screw extruder, or may be kneaded with a high filler content to form a masterbatch, which may be diluted to a required concentration during molding.

The polypropylene resin composition of the present invention comprises polypropylene resin (A), polypropylene resin (B) and biomass material (C), or polypropylene resin (A), polypropylene resin (B), biomass material (C) and thermoplastic elastomer ( It can be produced by mixing or heating and kneading D) and optional components to be blended as needed using a single-screw extruder, twin-screw extruder, or the like. The resin temperature for heating and kneading can be appropriately determined in the range of 100° C. to 300° C., taking into account the kneading load, the color and odor of the resin composition, and the like.

The polypropylene resin composition of the present invention can be appropriately molded into a desired shape by means such as pressure molding, film molding, vacuum molding, extrusion molding, and injection molding to produce various molded products. The molding temperature at this time can be appropriately determined in the range of 100° C. to 300° C., taking into consideration the kneading load, the color and odor of the resin composition, etc.

The polypropylene resin composition of the present invention can be used for various film/sheet materials, disposable molded products (e.g., containers, pipes, square timbers, rods, artificial wood, trays, concrete panels, foams, etc.), furniture, building materials, It can be effectively used as a material for interior and exterior materials for automobiles, casings and housings for home appliances, civil engineering and construction materials, materials for agriculture, dairy farming, and fisheries, materials for recreation, materials for sports, etc.

The polypropylene resin composition of the present invention is also suitably used in the fields of electrical insulation materials, industrial parts materials, building materials, etc., and among them, it is suitably used as a raw material for housing components, building materials, and home appliances. Specific examples include trays, tableware, speakers, bath unit floor pans, buckets, toilet seats, cabinets, stereo cabinets, baseboards, door materials, counter materials, window frames, sound insulation boards, shelves, civil engineering square timbers, pillars, and structures. Examples include wood, kitchen parts, floors, baths, base boards, piano organ main boards, ceiling materials for fittings, etc.

According to the polypropylene resin composition of the present invention, it is possible to effectively dispose of a large amount of excess inventory of agricultural products that are difficult to dispose of, and to reduce the amount of polypropylene resin produced from fossil fuels used. Furthermore, even if the molded article of the polypropylene resin composition of the present invention is incinerated after use, charcoal remains as a residue, so the amount of combustion heat and carbon dioxide generated is small, greatly contributing to the preservation of the global environment. Furthermore, even when disposed of in a landfill, the rate of return to the soil is high, making it environmentally friendly.

EXAMPLES Hereinafter, the present invention will be explained in more detail using Examples, but the present invention is not limited to these Examples.

1. Evaluation method (1) Melting point (Tm)
Measurement was performed using a differential scanning calorimeter DSC6200 manufactured by Seiko. Approximately 5 mg of the sheet-shaped sample was packed in an aluminum pan, and the temperature was raised from room temperature to 200 °C at a heating rate of 100 °C/min, held for 5 minutes, and then lowered to 40 °C at a rate of 10 °C/min. From the heat of fusion curve obtained when the temperature was raised to 200°C at a rate of 10°C/min, the maximum melting peak temperature was defined as the melting point Tm (°C).

(2) Melt flow rate (MFR)
The MFR of the polypropylene resins (A1), (A2), and (B) was measured at 230° C. and a load of 2.16 kg in accordance with JIS K7210. The MFR of the thermoplastic elastomer (D) was measured at 190°C and a load of 2.16 kg in accordance with JIS K6922-2. The unit is g/10 minutes.

(3) Melt tension MT
Measurement was performed using a capillograph manufactured by Toyo Seiki Seisakusho.
(Measurement condition)
・Capillary: diameter 2.0mm, length 40mm
・Cylinder diameter: 9.55mm
・Cylinder extrusion speed: 20mm/min ・Take-off speed: 4.0m/min ・Temperature: 230℃
If the melt tension MT is extremely high, the resin may break at a take-up speed of 4.0 m/min. In such a case, the take-up speed was lowered by 0.1 m/min, and the melt tension at the highest take-off speed was defined as MT. The unit is grams.

(4) Q value (Mw/Mn)
It was determined by GPC measurement according to the method below.
・Equipment: Waters GPC (ALC/GPC 150C)
・Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42μm)
・Column: Showa Denko AD806M/S (3 columns)
・Mobile phase solvent: orthodichlorobenzene (ODCB)
・Measurement temperature: 140℃
・Flow rate: 1.0ml/min ・Injection volume: 0.2ml
- Preparation of sample: For the sample, prepare a 1 mg/mL solution using ODCB (containing 0.5 mg/mL BHT), and dissolve at 140° C. for about 1 hour.
Conversion of the retention capacity obtained by GPC measurement into molecular weight is performed using a standard polystyrene calibration curve prepared in advance. As standard polystyrene, the following brands manufactured by Tosoh Corporation are used.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000

(5) Soluble content at 40° C. or lower measured by temperature-rising elution fractionation (TREF) method Measured according to the method described above.

(6) Pellet odor 100 g of pellets were weighed, sealed in a 500 ml glass container, held at 80° C. for 3 hours, the lid of the glass container was opened, and the odor of the pellets inside was sensory evaluated. The strength of odor is determined as follows.
◎: Almost no odor felt.
○: Slight odor is felt.
△: An odor is felt.
×: The odor is felt strongly.

(7) Extruded sheet molded product and its plastic feel The pellets were put into an extruder with a screw diameter of 40 mm, extruded through a T-shaped die at a resin temperature of 200°C, and then transferred to a mirror-finished metal cast roll with a surface temperature of 60°C. The sheet was sandwiched between the sheets and continuously pulled out at a speed of 1.2 m/min while being cooled and solidified to obtain a sheet of polypropylene resin composition having a width of 500 mm and a thickness of 1.0 mm.
The plastic feel of the obtained molded product was evaluated based on the reduction in gloss caused by the biomass material and the addition of patterns. The strength of the plastic feel is determined as follows.
○: Almost no plastic feel.
△: Slightly plastic feel.
×: It feels like plastic itself.
In addition, the extensibility at the die exit was evaluated by increasing the take-up speed in the above extrusion sheet molding and evaluating the state when a sheet with a thickness of 0.5 mm was obtained. The evaluation of spreadability is as follows.
○: The thickness of the sheet is uniform.
Δ: Part of the sheet is thinned and the thickness is non-uniform.
×: The sheet is torn and difficult to take back.

(8) Thermoformed product The minimum thickness of the thermoformed product was measured as follows.
A test piece with a size of 200 mm x 200 mm was cut out from the polypropylene resin sheet obtained in each Example and each Comparative Example, and fixed in a circular frame with an inner radius of 80 mm. Using a sag tester made by Misuzu Ellie, the tester was guided to a heating furnace in which heaters were arranged vertically and heated at an ambient temperature of 200℃, and 2 seconds after the maximum tension, the plug installed at the top of the sheet was inserted. The sheet was deep drawn by lowering the sheet at a rate of 0.1 m/sec using air cylinder pressure. For the obtained cone-shaped molded product with a height of 200 mm, the thickness of the body at 11 reference points set at 25 mm intervals between 25 mm and 175 mm in the height direction was measured with a micrometer, and the minimum measurement value was determined. The value was taken as the minimum thickness of the body.

The drawdown property of the thermoformed product was measured as follows.
A test piece with a size of 300 mm x 300 mm was cut out from the polypropylene resin sheet obtained in each Example and each Comparative Example, and was fixed horizontally to a frame with internal dimensions of 260 mm x 260 mm. Using a sag tester manufactured by Misuzu Ellie Co., Ltd., the sample was guided to a heating furnace in the tester in which heaters were arranged vertically and heated at an ambient temperature of 200°C, and the change in vertical displacement of the center of the sample over time from the start of heating was measured. were successively measured using a laser beam.
As the sheet is heated, it once sags (displaces in the negative direction), becomes stretched back (displaces in the positive direction) due to stress relaxation, and then sags again. The sheet position (displacement) at the start of heating is A (mm), the position (displacement) at maximum tension return is B (mm), the position (displacement) 10 seconds after maximum tension return is C (mm), Drawdown resistance was evaluated based on the following criteria.
◎: B-A≧0mm and C-B≧-5mm
○: B-A≧-5mm and C-B≧-10mm (except when B-A≧0mm and C-B≧-5mm)
△: B-A≧-5mm and C-B<-10mm, or B-A<-5mm and C-B≧-10mm
×: BA<-5mm and CB<-10mm
Here, B-A≧-5mm means that the sheet is tensed during container molding and a beautiful appearance without wrinkles can be formed, and C-B≧-10mm means that it is good. This means that the molding time range is sufficiently wide to obtain a molded product.

(9) Extruded foam molded product and its plastic feel 100 parts by mass of pellets of a polypropylene resin composition and 0.5 parts by mass of a chemical blowing agent (trade name: Hydrocellol CF40E-J, manufactured by Clariant Japan) as a cell regulator. The mixture was uniformly stirred and mixed using a ribbon blender, and the resulting mixture was introduced into a single-screw extruder having a barrel hole for injecting a physical blowing agent in the middle of the barrel. After heating and melting in the front stage of the extruder to plasticize and decompose the cell regulator, 0.50 parts by mass of liquefied carbon dioxide was injected and kneaded with a high-pressure pump to 100 parts by mass of the polypropylene resin composition. The polypropylene resin foam molding material was rapidly cooled in the latter stage of the extruder and extruded from a T-shaped die with a width of 750 mm and a lip width of 0.4 mm. The extruded foam sheet is first cooled on one side by a roll installed close to the die, then both sides are cooled by three rolls installed, and then taken off at a constant speed by pinch rolls to form a foam sheet with a thickness of 1.3 mm. I got it. The operating conditions of the extruder are as follows.
・Extruder diameter: 65mmφ, L/D=42, physical foaming agent injection port: L/D=20 position Screw rotation speed: 75 rpm
Discharge amount: approx. 65kg/h
The resulting plastic feel was evaluated as described in (7) above.
The foaming ratio is determined by cutting the foam, filling it without gaps into a cylindrical container with a height of 4.5 cm and a bottom surface with a radius of 1.9 cm, and measuring the mass, volume, and density of the foam, and measuring the gas The expansion ratio was calculated by measuring the porosity by compression.
The foam form was determined by cutting out a sample from the foam sheet, enlarging and projecting the cross section of the foam layer using a stereomicroscope (manufactured by Nikon Corporation: SMZ-1000-2 model), and making the following judgments regarding the bubble form in the cross section. .
○: Fine and uniform.
×: Coarse bubbles are present.

(10) Injection foam molded product and its plastic feel 100 parts by mass of pellets of polypropylene resin composition and 0.5 parts by mass of a chemical blowing agent (trade name: Hydrocellol CF40E-J, manufactured by Clariant Japan) as a cell regulator. The mixture was stirred and mixed uniformly using a ribbon blender, and the resulting mixture was used to perform injection foam molding by the open mold injection foam molding method as described below.
Injection molding was performed using "α-300" manufactured by FANUC as an injection molding machine at a cylinder temperature of 200° C. and an injection time of 1.0 seconds. The mold for injection molding was a flat plate with dimensions of 400 mm x 200 mm and variable thickness for molding a foam molded article (in this case, the mold cavity clearance (T0) was set to 2.0 mm). Foam molding was carried out using the material.
The mold temperature was set at 40°C.
The resulting plastic feel was evaluated as described in (7) above.
The expansion ratio was defined as the ratio between the thickness of the molded body after foaming by the mold opening operation and the mold cavity clearance (T0).
The bubble morphology was determined by cutting out a sample from the foam, enlarging and projecting the cross section of the foam layer using a stereomicroscope (manufactured by Nikon Corporation: Model SMZ-1000-2), and making the following judgments regarding the bubble morphology in the cross section. .
○: Fine and uniform.
×: Coarse bubbles are present.

(11) Blow-molded product and its plastic appearance Using a small direct blow molding machine JB105 manufactured by Japan Steel Works Co., Ltd. with a diameter of 50 mmφ and a cross-head screw and die of L/D 22, the molding temperature was 200 ° C. A polypropylene blow-molded body (cylindrical bottle) with a bottle weight of 30 g and an internal capacity of 550 cc was molded under conditions of a mold cooling temperature of 15° C. and a cooling time of 24 seconds.
The resulting plastic feel was evaluated as described in (7) above.
The degree of parison descent was determined as follows from the ratio of the parison upper wall thickness to the parison lower wall thickness when the parison was extruded from the small direct blow molding machine to a length of 0.5 m.
○: The ratio of the parison upper wall thickness to the parison lower wall thickness is 0.8 to 1.0.
△: The ratio of the parison top wall thickness to the parison bottom wall thickness is 0.6 to less than 0.8 ×: The ratio of the parison top wall thickness to the parison bottom wall thickness is less than 0.6 The minimum thickness is the center of the body of the cylindrical bottle. (at a height of 15 cm from the bottom), the wall thickness in four circumferential directions was measured using a micrometer manufactured by Mitutoyo, and the difference between the maximum and minimum values was determined. The smaller this value is, the more uniform the wall thickness of the cylindrical bottle is, the smaller the uneven thickness, and the higher the quality of the product.

(12) Tensile Modulus Using a molding machine (EC20 injection molding machine manufactured by Toshiba Machine Co., Ltd.) and the following mold, flat test pieces for physical property evaluation were prepared under the following conditions, and the "tensile modulus" described later was Used for evaluation.
- Mold = 2 flat test pieces (10 x 80 x 4t (mm)) for physical property evaluation.
- Molding conditions = molding temperature 220°C, mold temperature 30°C, injection pressure 50MPa, injection time 5 seconds, cooling time 20 seconds.
Using the flat test piece prepared above, measurement was performed at a test temperature of 23°C in accordance with JIS K7162. The determination of the tensile modulus is as follows.
○: Tensile modulus is 1,200 MPa or more ×: Tensile modulus is less than 1,200 MPa

2. Raw materials The raw materials used for evaluation are as follows. In addition, the physical property values of the raw materials are summarized in Table 1.
-Polypropylene resin (A1-1): Waymax MFX6 (product name) manufactured by Nippon Polypro Co., Ltd.
-Polypropylene resin (A2-1): Novatec BC6C (product name) manufactured by Nippon Polypro Co., Ltd.
-Polypropylene resin (A2-2): Novatec BC03C (product name) manufactured by Nippon Polypro Co., Ltd.
-Polypropylene resin (B-1): Wintech WFX6 (product name) manufactured by Nippon Polypro Co., Ltd.
-Polypropylene resin (B-2): Wintech WSX03 (product name) manufactured by Nippon Polypro Co., Ltd.
- Biomass material (C-1): Wood flour (100 mesh), manufactured by Casino Company - Biomass material (C-2): Wood flour (45 mesh), manufactured by Casino Company - Thermoplastic elastomer (D-1): Mitsui Chemicals Tafmer (registered trademark) A4050

(Examples 1 to 24, Comparative Examples 1 to 5)
The 29 types of polypropylene resin compositions shown in Tables 2 and 3 (Examples 1 to 24, Comparative Examples 1 to 5) were weighed and uniformly stirred and mixed using a ribbon blender. The resulting mixture was put into a twin-screw extruder with a screw diameter of 15 mm, kneaded at a resin temperature of 200°C, extruded into strands, cooled with water, and pelletized to obtain a polypropylene resin composition.

Pellet odor of the obtained polypropylene resin composition, extruded sheet molded product (plastic feel, die exit extensibility), thermoformed product (drawdown property, minimum thickness), extruded foam molded product (plastic feel, expansion ratio, cell morphology) ), injection foam molded products (plastic feel, expansion ratio, cell morphology), blow molded products (plastic feel, parison drop degree, minimum thickness), and strength were evaluated using the methods described above. The evaluation results are summarized in Tables 2 and 3.

Claims (8)

5 to 85% by mass of a polypropylene resin (A1) having a melting point of 150°C or higher and having the following characteristics (a-1), 5 to 85% by mass of a polypropylene resin (B) having a melting point of 110°C or higher and lower than 150°C, and biomass material A polypropylene resin composition comprising (C) 10 to 80% by mass (however, the total mass of (A1), (B) and (C) is 100% by mass).
Characteristics (a-1): Melt tension (MT) (unit: g) is log (MT) ≧ -0.9 × log (MFR) + 0.7, and
Satisfies log(MT)≧1.15 10% by mass or more of a polypropylene resin (A1) with a melting point of 150 °C or higher having the following property (a-1), a polypropylene resin (A2) with a melting point of 150 °C or higher having the following property (a-2) , and the above. Contains a total of 15 to 85% by mass of polypropylene resin (A1) , 5 to 75 % by mass of polypropylene resin (B) with a melting point of 110°C or higher and lower than 150°C, and 10 to 80% by mass of biomass material (C) ( However, the total mass of (A1), (A2), (B) and (C) is 100% by mass.) A polypropylene resin composition characterized in that:
Characteristics (a-1): Melt tension (MT) (unit: g) is log (MT) ≧ -0.9 × log (MFR) + 0.7, and
Characteristic (a-2) that satisfies log(MT)≧1.15: Melt tension (MT) (unit: g) is log(MT)<-0.9×log(MFR)+0.7, and log(MT ) < 1.15. Polypropylene resin (A1), or polypropylene resin (A1) and polypropylene resin (A2) are each independently produced from a propylene homopolymer, a propylene/ethylene block copolymer, or a propylene/ethylene/1-butene block copolymer. The polypropylene resin composition according to claim 1 or 2, characterized in that it is one or more polypropylene resins selected from the group consisting of: The polypropylene resin (B) is a propylene/ethylene random copolymer, a propylene/1-butene random copolymer, a propylene/ethylene/1-butene random copolymer, a propylene/ethylene random block copolymer, a propylene/ethylene random block copolymer, or a propylene/ethylene random copolymer. The polypropylene resin composition according to any one of claims 1 to 3, characterized in that it is one or more polypropylene resins selected from the group consisting of 1-butene random block copolymers. The polypropylene resin composition according to any one of claims 1 to 4, wherein the polypropylene resin (B) has the following properties (b-1) and/or (b-2).
(b-1) Q value is 5.0 or less (b-2) Soluble content at 40°C or less measured by temperature rising elution fractionation (TREF) method is 4.0% by mass or less A claim characterized in that the biomass material (C) is one or more plant-derived fillers selected from the group consisting of wood, pulp, bamboo, sugarcane (bagasse), rice husk, and rice (starch). 6. The polypropylene resin composition according to any one of 1 to 5. From the total of polypropylene resin (A1), polypropylene resin (B) and biomass material (C), or from 100% by mass of the total of polypropylene resin (A1), polypropylene resin (A2), polypropylene resin (B) and biomass material (C) The polypropylene resin composition according to any one of claims 1 to 6, further comprising 1 to 50 parts by mass of a thermoplastic elastomer (D) per 100 parts by mass of the polypropylene resin composition. An extruded foam molded article, an injection foam molded article, a sheet molded article, a thermoformed article, or a blow molded article made of the polypropylene resin composition according to any one of claims 1 to 7.