Powdery cellulose

Abstract

To provide a powdery cellulose which enhances tensile strength when formulated into a resin composition.SOLUTION: The present invention provides powdery cellulose for a molding resin material, the powdery cellulose having a particle diameter D50 of 10-100 μm, and the raw pulp for the powdery cellulose having a Canadian standard freeness of 400 mL or less. It is preferable that the powdery cellulose has an average fibril perimeter length of 3.6% or more when measured with Fiber Tester Plus.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to powdery cellulose.

Background Art

[0002] In recent years, powdery cellulose has been used as a reinforcing agent for resin materials such as rubber and plastic (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As one of the uses of a resin composition containing powdery cellulose, it is used for appearance parts such as home appliance housings, automotive interior and exterior parts. Characteristics required for appearance parts include mechanical strengths such as tensile strength, flexural strength, and impact strength. An object of the present invention is to provide powdery cellulose that improves tensile strength when used as a resin composition.

Means for Solving the Problems

[0005] The present invention provides the following [1] to [7]. [1] Powdery cellulose for a molding resin material having a particle size D50 of 10 to 100 μm, wherein the Canadian standard drainage degree of the raw material pulp of the powdery cellulose is 400 mL or less, and the powdery cellulose for a molding resin material. [2] The powdery cellulose for a molding resin material according to [1], wherein the average fibril perimeter length measured with a Fiber Tester Plus is 3.6% or more. [3] The powdery cellulose according to [1], wherein the raw material pulp of the powdery cellulose is derived from hardwood bleached kraft pulp (LBKP). 〔4〕The aspect ratio of the powdery cellulose is 5.0 to 10.0, and the powdery cellulose for the resin material for molding according to 〔1〕. 〔5〕The value obtained by subtracting the particle diameter D50 from the particle diameter D90 of the powdery cellulose (particle diameter D90 - particle diameter D50) is 70 to 120 μm, and the value obtained by subtracting the particle diameter D10 from the particle diameter D50 (particle diameter D50 - particle diameter D10) is 15 to 40 μm, and the powdery cellulose for the resin material for molding according to 〔1〕. 〔6〕A resin material for molding, comprising the powdery cellulose and a thermoplastic resin. 〔7〕The resin material for molding according to 〔6〕, wherein the content of the powdery cellulose is 10% by weight or more when the resin material for molding is 100% by weight.

Advantages of the Invention

[0006] According to the present invention, it is possible to provide powdery cellulose that improves the tensile strength when used as a resin composition.

Modes for Carrying Out the Invention

[0007] 〔1. Powdery Cellulose〕 The powdery cellulose has a predetermined average particle diameter, and the Canadian standard drainage degree of the raw material pulp is 400 mL or less.

[0008] 〔1.1. Average Particle Diameter〕 〔Particle Size Distribution〕 The particle size distribution of the powdery cellulose can be represented as the particle size distribution (10% diameter, 50% diameter, 90% diameter, D.10, D.50, D.90, respectively) when the integrated value of the volume accumulation distribution is 10%, 50%, and 90%. In this specification, the particle size distribution is a value obtained by wet measurement (with ultrasonic irradiation) using the laser scattering method as the measurement principle. The average particle diameter in this specification refers to the value of D.50 obtained by wet measurement (with ultrasonic irradiation).

[0009] - Wet measurement (with ultrasonic irradiation)- In this specification, the wet condition (with ultrasonic irradiation) refers to the condition where after adding water to the sample, ultrasonic irradiation is performed and then the particle size is measured. The preferred ranges of D.10, D.50, and D.90 in the wet (with ultrasonic) case are as follows. Generally, the larger the particle size, the higher the tendency for fibers to entangle with each other. Furthermore, within the following ranges, when added to resins, rubbers, etc., the strength can be appropriately improved without impairing their properties. D.10 is usually 3.0 μm or more, preferably 5.0 μm or more, and more preferably 10.0 μm or more. The upper limit is usually 20.0 μm or less, preferably 17.0 or less, and more preferably 15.0 μm or less. D.50 is usually 10.0 μm or more, preferably 20.0 μm or more, more preferably 30.0 μm or more, and even more preferably 35.0 μm or more (however, it is a value larger than D.10). The upper limit is usually 100.0 μm or less, preferably 80.0 μm or less, more preferably 60.0 μm or less, and even more preferably 50.0 μm or less. D.90 is usually 60.0 μm or more, preferably 80.0 μm or more, and more preferably 100.0 μm or more (however, it is a value larger than D.50). The upper limit is usually 200.0 μm or less, preferably 170.0 μm or less, and more preferably 150.0 μm or less.

[0010] The value obtained by subtracting the particle size D10 from the particle size D90 of the powdery cellulose of the present invention (particle size D90 - particle size D10) is preferably 100 to 150 μm, more preferably 110 to 140 μm, and even more preferably 110 to 130 μm. When the particle size D90 - particle size D10 is 100 to 150 μm, since the particle size distribution is appropriate, the tensile strength can be improved when added to the resin.

[0011] In addition, the value obtained by subtracting the particle diameter D50 from the particle diameter D90 of the powdery cellulose of the present invention (particle diameter D90 - particle diameter D50) is preferably 70 to 120 μm, more preferably 80 to 120 μm, and still more preferably 90 to 110 μm. When the particle diameter D90 - particle diameter D50 is 70 to 120 μm, since the powder having a large particle diameter is appropriately contained, the tensile strength can be improved when added to the resin.

[0012] In addition, the value obtained by subtracting the particle diameter D10 from the particle diameter D50 of the powdery cellulose of the present invention (particle diameter D50 - particle diameter D10) is preferably 15 to 40 μm, more preferably 15 to 30 μm, and still more preferably 20 to 30 μm. When the particle diameter D50 - particle diameter D10 is 15 to 40 μm, since the powder having a small particle diameter is appropriately contained, the tensile strength can be improved when added to the resin.

[0013] [[1.2. Average fiber width (μm), average fiber length (μm), average fiber length / average fiber width (L / D)]] The average fiber length is preferably 100 μm or more, more preferably 120 μm or more. The upper limit is preferably 300 μm or less, more preferably 200 μm or less.

[0014] The average fiber width is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more. The upper limit is usually 50 μm or less, preferably 40 μm or less, more preferably 35 μm or less.

[0015] The average fiber length / average fiber width (L / D) of the powdery cellulose is preferably 5.0 to 10.0, more preferably 5.0 to 8.0, and still more preferably 6.0 to 7.0. When L / D is 5.0 to 10.0, when a resin composition containing powdery cellulose is formed, the cellulose fibers are entangled with each other, thereby improving the tensile strength.

[0016] The average fiber length and average fiber width can be measured using the Fiber Tester Plus manufactured by ABB. In this specification, the average fiber length refers to the length-weighted fiber length when all fibers with a length of 0.0 mm or more are the analysis target, and the average fiber width refers to the width-weighted fiber width. L / D is a value calculated from these measured values.

[0017] [[1.3. Average fibril area (%), average fibril perimeter length (%)]] The average fibril area is preferably 1.0% or more, more preferably 1.3% or more. When the average fibril area is 1.0% or more, fibrillation (hairiness) on the fiber surface progresses, and when a resin composition containing powdered cellulose is formed, the cellulose fibers are more likely to entangle with each other, so the tensile strength is improved.

[0018] The average fibril perimeter length is preferably 2.0% or more, more preferably 3.0% or more. When the average fibril perimeter length is 2.0% or more, fibrillation (hairiness) on the fiber surface progresses, and when a resin composition containing powdered cellulose is formed, the cellulose fibers are more likely to entangle with each other, so the tensile strength is improved.

[0019] The average fibril area and average fibril perimeter length can be measured using the Fiber Tester Plus manufactured by ABB. In this specification, the average fiber length refers to the Fibril Area_Length (length-weighted average fibril area) and Fibril Perimeter_Length (length-weighted average fibril perimeter length) when all fibers with a length of 0.0 mm or more are the analysis target.

[0020] [[2.1. Cellulose raw material]] The cellulose raw material is usually naturally derived cellulose, preferably pulp, and more preferably wood-derived pulp. Examples of wood-derived pulp include softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), softwood bleached dissolving kraft pulp (NDKP), hardwood bleached dissolving kraft pulp (LDKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), hardwood unbleached sulfite pulp (LUSP), hardwood bleached sulfite pulp (LBSP), and other wood-derived pulps, thermomechanical pulp (TMP), pressure groundwood pulp (PGW), refiner groundwood pulp (RGP), alkaline hydrogen peroxide mechanical pulp (APMP), alkaline hydrogen peroxide thermomechanical pulp (APTMP), etc. Among them, kraft pulp is preferred as the material.

[0021] Examples of the method for preparing wood-derived pulp include methods involving treatment by a chemical pulping method (digestion method). By treatment with the chemical pulping method (digestion method), lignin, which is a coloring substance, is dissolved and removed, and high-whiteness pulp can be obtained by combining with oxygen delignification treatment and bleaching treatment. Examples of the chemical pulping method (digestion method) include sulfite digestion method, kraft digestion method, soda-quinone digestion method, and organosolv digestion method. From the perspectives of the environment and economy, kraft pulp is preferred. The kraft digestion method involves using alkali chemicals such as sodium hydroxide, potassium hydroxide, and sodium carbonate, and chemicals containing sulfur such as sodium sulfide and sodium sulfite in combination, and quinone-based cooking aids, polysulfide, etc. can be used as additives. These additives may not be used if digestion can be carried out with only alkali chemicals. Also, from the perspective of suppressing coloring, silver streaks, and odors when resin is heat-kneaded with a small amount of hemicellulose, pre-hydrolysis treatment may be carried out before kraft digestion.

[0022] In the method for preparing pulp, oxygen delignification can be performed on the pulp obtained by cooking. For the oxygen delignification used in the present invention, known medium-consistency methods or high-consistency methods can be applied as they are. In the case of the medium-consistency method, it is preferably carried out at a pulp concentration of 8 to 15% by mass, and in the case of the high-consistency method, it is preferably carried out at 20 to 35% by mass. As the alkali in oxygen delignification, sodium hydroxide and potassium hydroxide can be used, and as the oxygen gas, oxygen from cryogenic separation, oxygen from PSA (Pressure Swing Adsorption), oxygen from VSA (Vacuum Swing Adsorption), etc. can be used. The reaction conditions for the oxygen delignification treatment are not particularly limited, but the oxygen pressure is 3 to 9 kg / cm 2 , more preferably 4 to 7 kg / cm 2 , the alkali addition rate is 0.5 to 4% by mass, the temperature is 80 to 140 °C, the treatment time is 20 to 180 minutes, and other known conditions can be applied. In the present invention, the oxygen delignification treatment may be carried out multiple times.

[0023] The pulp subjected to the oxygen delignification treatment can be sent to, for example, a washing step next, and after washing, a bleaching treatment as described later may be carried out. The whiteness of the pulp subjected to the oxygen delignification treatment is preferably 30% to 55% based on ISO 2470.

[0024] In the method for preparing pulp, in addition to the chemical pulping method (kraft method) and oxygen delignification treatment, bleaching treatment can also be carried out. Thereby, pulp with a higher whiteness can be obtained. As the bleaching treatment method, for example, for pulp that has been optionally delignified by a normal method, chlorine treatment (C), chlorine dioxide bleaching (D), alkaline extraction (E), hypochlorite bleaching (H), hydrogen peroxide bleaching (P), alkaline hydrogen peroxide treatment stage (Ep), alkaline hydrogen peroxide / oxygen treatment stage (Eop), ozone treatment (Z), chelating treatment (Q), and methods of performing a combination of two or more of these treatments can be mentioned. Examples of the combination (sequence) of two or more treatments include, for example, D-E / P-D, C / D-E-H-D, Z-E-D-PZ / D-Ep-D, Z / D-Ep-D-P, D-Ep-D, D-Ep-D-P, D-Ep-P-D, Z-Eop-D-D, Z / D-Eop-D, Z / D-Eop-D-E-D (in the sequence, " / " means performing the treatments before and after " / " continuously without washing). The bleaching treatment is not limited to the above examples and may be a generally used method. The pulp that has undergone the bleaching treatment is usually in a fluid state (fluid pulp).

[0025] The whiteness of the pulp subjected to such bleaching treatment is preferably 70% or more based on ISO 2470.

[0026] The moisture content of the cellulose raw material is usually preferably 5 to 30%, preferably 5 to 20% with respect to 100% of the cellulose raw material. When the moisture content of the cellulose raw material is more than the aforementioned range, the moisture content may be adjusted by the dehydration / drying treatment described later.

[0027] [2.2. Canadian standard drainage degree] In the present invention, for the raw material pulp of powdered cellulose, by using pulp with a Canadian Standard Freeness (CSF) of 400 ml or less, the tensile strength is improved when kneaded with the resin material for molding. The Canadian Standard Freeness of the pulp used in the present invention is 400 ml or less, and more preferably 380 ml or less. By setting the Canadian Standard Freeness to 400 ml or less, fibrillation (linting) of the pulp proceeds moderately, and after pulverization into powdered cellulose, when kneaded with the resin material for molding, the cellulose fibers are more likely to entangle with each other, improving the tensile strength of the resin material. Generally, the Canadian Standard Freeness of pulp can be adjusted by treatment with a known beating machine such as a double disk refiner, single disk refiner, conical refiner, or PFI mill.

[0028] 〔3. Method for manufacturing powdered cellulose〕 The method for manufacturing powdered cellulose is not particularly limited as long as it is a method for obtaining powdered cellulose from a cellulose raw material. For example, a method including at least a pulverization treatment can be mentioned, and a method including a mechanical pulverization treatment is preferred.

[0029] 〔Mechanical pulverization treatment〕 The pulverization treatment is a treatment for mechanically pulverizing the cellulose raw material. Prior to the pulverization treatment, pretreatment such as dehydration / drying treatment and acid hydrolysis treatment may be performed, and dehydration / drying treatment is preferred. Classification treatment may be performed simultaneously with or after the pulverization treatment.

[0030] Examples of the pulverizer include a cutting mill, impact mill, air classifier mill, hammer mill, roll mill, roller mill, media mill, media agitation mill, and cryogenic grinder, and they may be used alone or in combination of two or more.

[0031] Examples of cutting mills include, for example, cutting mills (manufactured by Horai Co., Ltd.), mesh mills (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hyakuma Seisakusho Co., Ltd.), knife mills (manufactured by Palman), cutter mills (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.), centric cutters (manufactured by Nippon Coke & Engineering Co., Ltd.), rotary cutter mills (manufactured by Nara Machinery Co., Ltd.), turbo cutters (manufactured by Freund Turbo Co., Ltd.), and pulp crushers (manufactured by Zuiho Co., Ltd.).

[0032] Examples of hammer mills include, for example, hammer mills (manufactured by Hosokawa Micron Corporation), jaw crushers (manufactured by Makino Co., Ltd.), and hammer crushers (manufactured by Mino Industries Co., Ltd.).

[0033] Examples of impact mills include, for example, pulverizers (manufactured by Hosokawa Micron Corporation), fine impact mills (manufactured by Hosokawa Micron Corporation), Super Micron Mills (registered trademark, manufactured by Hosokawa Micron Corporation), Inomizers (registered trademark, manufactured by Hosokawa Micron Corporation), fine mills (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), CUM type centrifugal mills (manufactured by Mitsui Mining Co., Ltd.), Ixeed mills (manufactured by Mino Industries Co., Ltd.), Ultra Plex (manufactured by Mino Industries Co., Ltd.), Contra Plex (manufactured by Mino Industries Co., Ltd.), Colo Plex (manufactured by Mino Industries Co., Ltd.), atomizers (manufactured by Seishin Enterprise Co., Ltd.), Tornade mills (manufactured by Nikkiso Co., Ltd.), near mills (manufactured by Dalton Co., Ltd.), free crushers (manufactured by Nara Machinery Co., Ltd.), New Cosmomizers (manufactured by Nara Machinery Co., Ltd.), turbo mills (manufactured by Freund Turbo Co., Ltd.), Super Powder Mills (manufactured by Nishimura Machinery Works Co., Ltd.), blade mills (manufactured by Nisshin Engineering Co., Ltd.), Super Rotors (manufactured by Nisshin Engineering Co., Ltd.), Wiley crushers (manufactured by Sanki Seisakusho Co., Ltd.), pulp crushers (manufactured by Zuiho Co., Ltd.), Jacobson fine crushers (manufactured by Kobe Steel Pantech Co., Ltd.), universal mills (manufactured by Tokuju Kousakusho Co., Ltd.), and continuous vibro mills (manufactured by Eurastech Co., Ltd.).

[0034] Examples of the air classifier mills include CGS type jet mill (manufactured by Mitsui Mining Co., Ltd.), micron jet (registered trademark, manufactured by Hosokawa Micron Corporation), counter jet mill (registered trademark, manufactured by Hosokawa Micron Corporation), cross jet mill (manufactured by Kurimoto Iron Works, Ltd.), supersonic jet mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), current jet (manufactured by Nisshin Engineering Co., Ltd.), jet mill (manufactured by Sanjo Industry Co., Ltd.), selen mirror (manufactured by Masayuki Sangyo Co., Ltd.), new micro cyclotmat (manufactured by Masuno Seisakusho Co., Ltd.), and crypton (manufactured by Earth Technica Co., Ltd.).

[0035] Examples of the roller mills include vertical roller mill (manufactured by Seishin Co., Ltd.), vertical roller mill (manufactured by Shinion Co., Ltd.), roller mill (manufactured by Kotobuki Giken Kogyo Co., Ltd.), VX mill (Kurimoto Iron Works, Ltd.), KVM type vertical roller mill (Earth Technica Co., Ltd.), and IS mill (IHI Plant Engineering Co., Ltd.). Among these, the cutting mills and roller mills are preferred.

[0036] The conditions for the grinding treatment can be appropriately set so as to obtain the desired powdery cellulose. For example, the treatment conditions can be adjusted with reference to a calibration curve created from the grinding conditions (e.g., treatment time, input amount) and the desired physical properties of the powdery cellulose.

[0037] -Neutralization, washing, dehydration, and drying treatment- The cellulose raw material is appropriately pretreated before the grinding treatment. Examples of the pretreatment include neutralization, washing, liquid removal, and drying treatment, and it is preferable to perform the dehydration and drying treatments in this order. The cellulose raw material can adjust the solid content concentration by the drying (dehydration) treatment, and it is easy to control the physical property values of the powdery cellulose.

[0038] -Acid hydrolysis treatment- Examples of the acid used for the acid hydrolysis treatment include mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid. The acid concentration is not particularly limited, but from the viewpoints of maintaining the degree of polymerization and whiteness, it is preferably lower than the acid concentration in the acid hydrolysis treatment for the production of conventional powdered cellulose, more preferably 0.4 to 2.0 N, and even more preferably 0.5 to 1.5 N. If the acid concentration is less than 0.4 N, the depolymerization of cellulose by the acid is suppressed and the decrease in the degree of polymerization of cellulose can be reduced, but the micronization may be difficult in some cases. On the other hand, if it exceeds 2.0 N, the depolymerization of cellulose proceeds and the micronization becomes easy, so the powder fluidity is improved, but the tablet hardness may decrease with the decrease in the degree of polymerization (when molded, it may be easily disintegrated). The reaction conditions for the acid hydrolysis treatment are not particularly limited, but the reaction temperature is usually 80 to 100 °C, and the reaction time is usually 30 minutes to 3 hours.

[0039] Prior to the acid hydrolysis treatment, pretreatment may be performed on the cellulose raw material. For example, slurrying of the cellulose raw material (preparation of a dispersion) and adjustment of the cellulose raw material concentration can be mentioned. The concentration of the cellulose raw material is usually 3 to 10% by weight (in terms of solid content) with respect to the dispersion. When the cellulose raw material is a bleached fluid pulp, usually, a treatment for increasing the pulp concentration is often performed before hydrolysis. For the adjustment (concentration) of the cellulose raw material concentration, a dehydrator such as a screw press or a belt filter may be used. The acid hydrolysis treatment may be performed on the slurry of the cellulose raw material, or may be performed on the sheet-like cellulose raw material. When the cellulose raw material is a dry sheet of pulp, usually, the pulp is loosened and then the acid hydrolysis treatment is performed. When loosening the pulp, a crusher such as a roll crusher may be used.

[0040] During the pulverization treatment after the acid hydrolysis, if necessary, at least one other component (for example, an organic component, an inorganic component) may be subjected to the pulverization treatment together with the acid hydrolysis product. Thereby, functionality can be imparted to the powdered cellulose or the functionality can be improved. The blending amount of the other component may be appropriately selected as an appropriate amount. Further, prior to the pulverization step, the acid hydrolysis product may be further subjected to the above-mentioned neutralization, washing, dehydration, and drying treatments.

[0041] The powdery cellulose may be chemically treated if necessary. The chemical treatment is preferably a treatment that does not significantly impair the degree of polymerization of the cellulose raw material. The timing of the chemical treatment may be carried out during the pulverization treatment of the cellulose raw material, or may be carried out before the pretreatment of the pulverization treatment.

[0042] 〔4. Uses of Powdery Cellulose〕 As other uses of the powdery cellulose, for example, it can be used as an industrial additive (for example, for resins such as polypropylene, phenolic resin, melamine resin, etc., for various rubbers). It can also be used as a component and raw material of resin compositions (for example, polyolefin resins, modified polyolefin resins, rubbers), rubber compositions (for example, automobiles, personal computers, building materials, containers), etc.

[0043] The powdery cellulose of the present invention can be particularly used as a resin material for molding. By using the powdery cellulose of the present invention in the resin material for molding, the tensile strength can be improved.

[0044] When the powdery cellulose of the present invention is used for a resin material for molding, although there is no particular limitation, the content of the powdery cellulose can be 10% by weight or more when the resin material for molding is 100% by weight.

Examples

[0045] Hereinafter, the present invention will be described with reference to examples. The following examples do not limit the present invention. The test methods in the examples of the present application are shown below. The measurement methods of physical property values and the like are the measurement methods described above unless otherwise specified.

[0046] <Average Particle Diameter> A laser diffraction particle size distribution analyzer (MasterSizer 3000, manufactured by Spectris, Malvern Panalytical) was used. The laser scattering method was used as the measurement principle, and the particle size distribution was measured by wet measurement (with ultrasonic irradiation). When the particle size distribution was expressed as a volume accumulation distribution, the values at which the integrated values of the volume accumulation distribution were 10%, 50%, and 90% were defined as the particle size distribution D.10, D.50, and D.90, respectively. The D.50 of the wet (with ultrasonic irradiation) was taken as the average particle size.

[0047] For the wet measurement, the sample was added to the measurement part in water being stirred at 3000 rpm so that the scattering intensity became about 10%. When irradiating ultrasonic waves, ultrasonic waves were applied to the sample in water based on the following conditions and then the wet measurement was carried out. · Mode: Continuous · Intensity: 100% · Time: 600 seconds

[0048] The analysis of the particle size distribution was carried out under the following conditions for all measurement conditions. · Analysis: General purpose · Analysis sensitivity: Emphasized · Light scattering model: Mie theory

[0049] <Average fiber length (μm), average fiber width (μm), L / D (aspect ratio), average fibril area (%), average fibril perimeter length (%)> The measurement was carried out using an L&W Fiber Tester Plus (manufactured by ABB) according to the following procedure. Place 0.1 g of the sample into a cylinder containing 200 ml of pure water, stir for about 1 minute, then transfer it to a dedicated 300 ml beaker, set it on a sample cycler, start the measurement, and perform the measurement until more than 55,000 fibers with a fiber length of 0.1 mm or more are counted. Calculate the length-weighted fiber length and width-weighted fiber width, and use these as the average fiber length and average fiber width of the powdered cellulose. Calculate the Fibrill Area Length and Fibrill Perimeter Length, and use these as the average fibrill area and average fibrill perimeter length. Divide the obtained average fiber length by the average fiber width to calculate the L / D (aspect ratio). In addition, the measurement was performed after setting the Max value of Fines Limit to 0.0 and the Min value of Length class1 to 0.001 on the Sample type screen for determining the measurement conditions. Divide the obtained average fiber length by the average fiber width to calculate the L / D (aspect ratio).

[0050] <Canadian standard water filtration degree> Measured in accordance with JIS P 8121-2:2012.

[0051] <Resin composition and test piece> A resin composition containing powdered cellulose was prepared as follows. Powdered cellulose, polypropylene resin (J779EA, manufactured by Prime Polymer Co., Ltd.), and maleic anhydride-modified polypropylene (Yumex 1010, manufactured by Sanyo Chemical Industries, Ltd.) were weighed in a ratio of 51:48.5:0.5 to a total of 8 g, and 8 portions were prepared. Each 8 g of the weighed materials was put into a small kneader ("MC15" manufactured by Xplore Instruments), kneaded at a temperature of 200°C for 5 minutes, and 5 dumbbell-shaped test pieces (type A12, JIS K7139) and 8 strip-shaped test pieces (type B1, JIS K7139) were molded using an Xplore injection molding machine (manufactured by Xplore Instruments) under the conditions of a cylinder temperature of 200°C and a mold temperature of 40°C.

[0052] <Tensile strength (MPa)> For the obtained dumbbell-shaped test pieces, using a precision universal testing machine ("Autograph AG-Xplus" manufactured by Shimadzu Corporation), in accordance with JIS K 7161: Test Method for Tensile Properties of Plastics, the tensile stress was measured at a test speed of 1 mm / min and an initial gauge length of 30 mm, and the maximum value was taken as the tensile strength. The average value of the tensile strengths of 5 test pieces was taken as the tensile strength of the sample.

[0053] <Flexural strength (MPa)> For the obtained strip-shaped test pieces, using a precision universal testing machine ("Autograph AG-Xplus" manufactured by Shimadzu Corporation), in accordance with JIS K7171, a flexural test was carried out with a distance between supports of 64 mm and a test speed of 10 mm / min, and the maximum flexural stress that the test piece could withstand during the flexural test was taken as the flexural strength. The average value of the flexural strengths of 3 test pieces was taken as the flexural strength of the sample.

[0054] <Charpy impact strength (kJ / m 2 )> For the obtained strip-shaped test pieces, a Charpy impact test was carried out using a Charpy impact tester (model: IT, manufactured by Toyo Seiki Seisakusho Co., Ltd.). A notch with a depth of 2 mm was inserted into the center of the test piece. The opposite side of the notch was struck using a pendulum of JC005J (0.5 J), and the impact strength was calculated. The average value of the Charpy impact strengths of 5 test pieces was taken as the Charpy impact strength of the sample.

[0055] <Preparation of powdered cellulose> (Example 1) Hardwood-derived sun-dried kraft pulp was dispersed in water to form a 4% by mass aqueous dispersion, and using a double disk refiner (manufactured by Aikawa Iron Works Co., Ltd.), beating was carried out under the condition of a clearance of 0.2 mm until the Canadian standard freeness reached 368 ml. Then, using a paper machine, wet paper was made from this pulp dispersion at a paper-making speed of 110 m / min, and dryer drying was carried out to obtain a basis weight of 320 g / m 2, an LBKP dry sheet with 7% moisture was obtained. Using this dry sheet as a raw material, it was roughly pulverized with a cutting mill (PI-20120, manufactured by Horai Co., Ltd., screen diameter Φ3 mm), and then pulverized with a cutting mill (HA8-2542, manufactured by Horai Co., Ltd., main mesh: 165 mesh, auxiliary mesh: 20 mesh) to obtain the powdered cellulose of Example 1. The various physical property values are shown in Table 1.

[0056] (Comparative Example 1) The powdered cellulose obtained by treating in the same manner as in Example 1 except that the beating treatment of the raw material pulp was not performed was used as the powdered cellulose of Comparative Example 1. The various physical property values are shown in Table 1.

[0057]

Table 1

[0058] In Example 1 where the D50 of the powdered cellulose was 10 to 100 μm and the Canadian standard freeness of the raw material pulp was 400 mL or less, the tensile strength was improved when a resin composition was made as compared with Comparative Example 1 outside the range.

Claims

1. Powdery cellulose for a molding resin material having a particle size D50 of 10 to 100 μm, wherein the Canadian standard drainage degree of the raw material pulp of the powdery cellulose is 400 mL or less, the powdery cellulose for a molding resin material.

2. The powdery cellulose for a molding resin material according to Claim 1, wherein the average fibril perimeter length measured with a Fiber Tester Plus is 3.6% or more.

3. The powdery cellulose for a molding resin material according to Claim 1, wherein the raw material pulp of the powdery cellulose is derived from hardwood kraft pulp (LBKP).

4. The powdery cellulose for a molding resin material according to Claim 1, wherein the aspect ratio of the powdery cellulose is 5.0 to 10.

0.

5. The powdery cellulose for a molding resin material according to Claim 1, wherein the value obtained by subtracting the particle size D50 from the particle size D90 (particle size D90 - particle size D50) of the powdery cellulose is 70 to 120 μm, and the value obtained by subtracting the particle size D10 from the particle size D50 (particle size D50 - particle size D10) is 15 to 40 μm.

6. A molding resin material comprising the powdery cellulose and a thermoplastic resin.

7. The molding resin material according to Claim 6, wherein the content of the powdery cellulose is 10% by weight or more when the molding resin material is 100% by weight.

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