Powdery cellulose

Abstract

To provide powdery cellulose which affords natural tones of color derived from wood when being formed into a resin composition.SOLUTION: Powdery cellulose has an average particle diameter of 10 to 100 μm, wherein when the powdery cellulose is 100 wt.%, a hemicellulose content is 10 to 30 wt.%, and when the temperature is raised under the condition of 20°C / min in a thermal analysis device (TG), a heat weight reduction rate at 110°C to 300°C is 4 to 15%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to powdered cellulose. [Background technology]

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

[0003] [Patent Document 1] Patent Publication No. 2022-012875 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the applications of resin compositions containing powdered cellulose is for exterior parts such as housings for home appliances and interior and exterior parts for automobiles. In addition to mechanical strength such as rigidity and impact strength, color is considered important as a property required for exterior parts, and it is desired that the natural color derived from wood is obtained when the resin composition is made. However, since general cellulose fibers become colored when heated, there was an issue that the color of the resin composition was not stable.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a powdery cellulose that exhibits a natural color inherent to wood when made into a resin composition. [Means for solving the problem]

[0006] The present invention provides the following [1] to [3]. [1] Powdered cellulose having an average particle size of 10 to 100 μm, a hemicellulose content of 10 to 30% by weight when the powdered cellulose is taken as 100% by weight, and a thermal weight loss rate of 4 to 15% at 110°C to 300°C when heated at 20°C / min in a thermal analyzer (TG). [2] The powdery cellulose according to [1], having an average fiber length / average fiber width (L / D) of 2.0 to 10.0. [3] The powdered cellulose according to [1], wherein the raw material pulp is pulp derived from broad-leaved trees. Effect of the Invention

[0007] According to the present invention, it is possible to provide powdered cellulose that exhibits a natural color inherent to wood when made into a resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [1. Powdered cellulose] The powdered cellulose has a given average particle size and hemicellulose content, and exhibits a thermal weight loss rate of 4 to 15% at 110° C. to 300° C. when heated at 20° C. / min in a thermal analyzer (TG).

[0009] [1.1. Average particle size] [Particle size distribution] The particle size distribution of powdered cellulose can be expressed as the particle size distribution when the integrated value of the volume accumulation distribution is 10%, 50%, and 90% (10% diameter, 50% diameter, and 90% diameter, respectively, D.10, D.50, and D.90). In this specification, the particle size distribution is a value obtained by wet measurement (with ultrasonic irradiation) using a laser scattering method as the measurement principle. In this specification, the average particle size refers to the D.50 value obtained by wet measurement (with ultrasonic irradiation).

[0010] -Wet measurement (with ultrasonic irradiation)- In this specification, wet conditions (with ultrasonic irradiation) refer to conditions in which water is added to a 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 case of wet conditions (with ultrasonic irradiation) are as follows. In general, the larger the particle size, the more likely the fibers are to become entangled. Furthermore, by being 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 μm 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, and more preferably 25.0 μm or more (but 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 50.0 μm or more, preferably 60.0 μm or more, and more preferably 65.0 μm or more (but is a value larger than D.50). The upper limit is usually 200.0 μm or less, preferably 180.0 μm or less, and more preferably 150.0 μm or less.

[0011] [1.2. Average fiber width (μm), average fiber length (μm), average fiber length / average fiber width (L / D)] The average fiber length is preferably 30 μm or more, more preferably 50 μm or more, and the upper limit is preferably 300 μm or less, more preferably 200 μm or less.

[0012] The average fiber width is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and the upper limit is usually 50 μm or less, preferably 40 μm or less, more preferably 35 μm or less.

[0013] The powdered cellulose has an average fiber length / average fiber width (L / D) of preferably 2.0 to 10.0, more preferably 2.0 to 8.0, and even more preferably 2.0 to 5.0. When L / D is 2.0 to 10.0, the resin composition containing the powdered cellulose has good fluidity, so that excessive shear heat is unlikely to be applied, and excessive coloring and color unevenness are prevented, resulting in a stable color tone.

[0014] The average fiber length and average fiber width can be measured using a Fiber Tester Plus manufactured by ABB Corp. In this specification, the average fiber length refers to the length-weighted fiber length and the average fiber width refers to the width-weighted fiber width when all fibers of 0.0 mm or more are analyzed.

[0015] [1.3.NDF] NDF is an abbreviation for neutral detergent fiber, and indicates organic matter that does not dissolve when a sample is boiled in a neutral detergent solution, and is generally a value indicating the total fiber amount. The NDF in the powdered cellulose of the present invention is mainly a value obtained by adding up the amount of cellulose, the amount of hemicellulose, and the amount of lignin. When the powdered cellulose is taken as 100% by weight, the NDF contained in the powdered cellulose is not particularly limited as a lower limit, but is preferably 70% by weight or more, and more preferably 80% by weight or more.

[0016] In this specification, the NDF content can be measured under the following conditions, and the values ​​in the examples are also values ​​measured by the following method. Accurately weigh 2 to 5 g of the analytical sample and place it on an aluminum weighing dish (previously dried and weighed). The sample is placed in a 1L volumetric flask (previously weighed accurately), dried at 135±2°C for 2 hours, cooled in a desiccator, weighed accurately, and the water content of the sample is calculated. 18.6g of disodium dihydrogen ethylenediaminetetraacetate dihydrate, 6.8g of sodium borate decahydrate, and 4.6g of disodium hydrogen phosphate are weighed and placed in a 1L volumetric flask, and 500mL of water is added to dissolve. 30.0g of sodium n-dodecyl sulfate, 10mL of triethylene glycol, and 250mL of water are added to this solution and mixed, and then water is added up to the mark on the volumetric flask to prepare a neutral detergent solution. Before use, confirm that the pH is in the range of 6.95 to 7.05. 0.5g of the sample to be analyzed is weighed accurately and placed in a 500mL tall beaker, and 0.5g of sodium sulfite and 50mL of neutral detergent solution are added. The tall beaker is covered with a watch glass or a cooler, and heated to boiling in a preheated fiber boiling apparatus. After boiling for 1 hour while replenishing the evaporated water, the tall beaker is removed from the fiber boiling apparatus, and the contents of the tall beaker are suction filtered through a glass filter (P2, FossTecator, pore size 40-100 μm, or equivalent). The residue in the glass filter (neutral detergent insolubles) is washed three times with 40 mL of hot water, and then washed three or four times with 10-20 mL of acetone, and then air-dried until the acetone odor disappears. Next, the glass filter is dried at 135 ± 2 ° C for 2 hours, cooled in a desiccator, and the weight of the neutral detergent insolubles is accurately weighed. The glass filter is further heated at 520-550 ° C for 2-5 hours to incinerate the neutral detergent insolubles, heated at 150 ° C for 2 hours, cooled in a desiccator, and the weight of the ash is accurately weighed. The NDF (% dry matter) in the sample is calculated by subtracting the amount of ash from the amount of neutral detergent insoluble matter described above.

[0017] [1.4.ADF] ADF is an abbreviation for acid detergent fiber, and is a value indicating organic matter that does not dissolve when a sample is boiled in an acid detergent solution. The ADF in the powdered cellulose of the present invention is mainly a value obtained by adding up the amount of cellulose and the amount of lignin. The ADF content in the powdered cellulose is preferably 85% by weight or more, more preferably 80% by weight or more, and more preferably 75% by weight or more, when the powdered cellulose is 100% by weight. The lower limit is not particularly limited, but is preferably 60% by weight or more, and more preferably 70% by weight or more.

[0018] In this specification, the ADF content can be measured under the following conditions, and the values ​​in the examples are also values ​​measured by the following method. Accurately weigh 2 to 5 g of the analytical sample and place it on an aluminum weighing dish (previously dried and weighed). The sample is placed in a 500mL tall beaker, 100mL of acid detergent solution is added, and the tall beaker is covered with a watch glass or a cooler and boiled. After boiling for 1 hour while replacing the water that evaporates, the contents of the tall beaker are suction filtered through a glass filter (P2, FossTecator, pore size 40-100μm, or equivalent). The residue in the glass filter (acid detergent insoluble matter) is thoroughly washed with hot water, washed 3-4 times with 10-20mL of acetone, and then air-dried until the acetone odor disappears. Next, the glass filter is dried at 135°C for 2 hours, cooled in a desiccator, and the weight of the acid detergent insoluble matter is accurately weighed. The glass filter is further heated at 520-550°C for 2 hours to incinerate the acid detergent insoluble matter, heated at 150°C for 2 hours, cooled in a desiccator, and the weight of the ash is accurately weighed. The ADF (% of dry matter) in the sample is calculated by subtracting the amount of ash from the amount of acid detergent insoluble matter obtained earlier.

[0019] [1.5. Hemicellulose] The powdered cellulose may contain hemicellulose. The amount of hemicellulose in the powdered cellulose is usually 10 to 30% by weight, preferably 10 to 20% by weight, and more preferably 10 to 15% by weight, when the powdered cellulose is taken as 100% by weight. When the amount of hemicellulose is 10 to 30% by weight, excessive coloring and color unevenness when heated and kneaded with resin are suppressed, and a natural color derived from wood can be produced.

[0020] The hemicellulose content can be calculated from the difference between the above NDF and ADF.

[0021] [1.6. Thermogravimetric reduction rate] The powdered cellulose of the present invention has a thermal weight loss rate of usually 4 to 15%, and preferably 5 to 10%, at 110 to 300°C when heated at 20°C / min in a thermal analyzer under a nitrogen atmosphere. If the thermal weight loss rate is 4 to 15%, excessive coloring and color unevenness when heated and kneaded with a resin can be suppressed, and a natural color inherent to wood can be obtained.

[0022] The thermal weight retention rate can be determined by reading the weights at 110°C and 300°C when the temperature is raised from 35°C to 550°C at 20°C / min in a nitrogen atmosphere using a thermal analyzer such as TG, and confirming the rate of change as the thermal weight loss rate (%).

[0023] [2. Cellulose raw materials] The cellulose raw material is usually naturally derived cellulose, preferably pulp, 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 Examples of such pulps include wood-derived pulps such as bleached hardwood pulp (LUSP) and bleached hardwood sulfite pulp (LBSP), thermomechanical pulp (TMP), pressurized groundwood pulp (PGW), refiner ground wood pulp (RGP), alkaline peroxide mechanical pulp (APMP), and alkaline peroxide thermomechanical pulp (APTMP). However, pulp derived from hardwoods that contains a certain amount of hemicellulose is more preferable.

[0024] Examples of methods for preparing wood-derived pulp include chemical pulping (cooking) methods. By chemical pulping (cooking), lignin, a coloring substance, is dissolved and removed, and by combining this with oxygen delignification and bleaching, pulp with high whiteness can be obtained. Examples of chemical pulping (cooking) methods include sulfite cooking, kraft cooking, soda-quinone cooking, and organosolv cooking. Kraft pulp is preferred from the environmental and economical standpoints, and because a certain amount of hemicellulose remains and it is easy to color the pulp brown. Kraft cooking uses alkaline chemicals such as sodium hydroxide, potassium hydroxide, and sodium carbonate, as well as chemicals containing sulfur such as sodium sulfide and sodium sulfite, and can use quinone-based cooking aids, polysulfides, and other additives. These additives do not need to be used if the pulp can be cooked using only alkaline chemicals.

[0025] In the method for preparing pulp, the pulp obtained by cooking can be subjected to oxygen delignification. The oxygen delignification used in the present invention can be a known medium or high consistency method. In the case of the medium consistency method, the pulp consistency is preferably 8 to 15% by mass, and in the case of the high consistency method, it is preferably 20 to 35% by mass. As the alkali in the oxygen delignification, sodium hydroxide or potassium hydroxide can be used, and as the oxygen gas, oxygen from the cryogenic separation method, oxygen from PSA (Pressure Swing Adsorption), oxygen from VSA (Vacuum Swing Adsorption), etc. can be used. The reaction conditions for the oxygen delignification are not particularly limited, but the oxygen pressure is 3 to 9 kg / cm2, more preferably 4 to 7 kg / cm2, 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 may be performed multiple times.

[0026] The pulp that has been subjected to the oxygen delignification treatment may then be sent to a washing step, and after washing, may be subjected to a bleaching treatment as described below. The brightness of the pulp that has been subjected to the oxygen delignification treatment is preferably 30% to 55% based on ISO 2470.

[0027] In the preparation of pulp, in addition to chemical pulping (cooking) and oxygen delignification, a bleaching treatment can also be carried out. This results in a pulp with a higher brightness. Examples of bleaching treatment methods include 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), chelate treatment (Q), and combinations of two or more of these treatments on pulp that has been delignified by any conventional method. Examples of combinations (sequences) of two or more treatments include DE / PD, C / DEHD, ZED-PZ / D-Ep-D, Z / D-Ep-DP, D-Ep-D, D-Ep-DP, D-Ep-PD, Z-Eop-DD, Z / D-Eop-D, and Z / D-Eop-DED (the " / " in the sequence means that the treatments before and after the " / " are performed consecutively without washing). The bleaching treatment is not limited to the above examples, and may be a commonly used method. Pulp that has been bleached is usually in a fluid state (fluid pulp).

[0028] The brightness of such bleached pulp is 70% according to ISO 2470. The above is preferred.

[0029] The moisture content of the cellulose raw material is usually preferably 5 to 30%, and more preferably 5 to 20%, based on 100% of the cellulose raw material. When the moisture content of the cellulose raw material is higher than the above range, the moisture content may be adjusted by a dehydration / drying treatment described below.

[0030] 3. Method for producing powdered cellulose The method for producing 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 grinding treatment is included, and a method including a mechanical grinding treatment is preferred.

[0031] [Mechanical crushing process] The pulverization process is a process in which the cellulose raw material is mechanically pulverized. Prior to the pulverization process, pretreatment such as dehydration / drying or acid hydrolysis may be performed, with dehydration / drying being preferred. Classification may be performed simultaneously with or after the pulverization process.

[0032] Examples of the pulverizer include a cutting mill, an impact mill, an airflow mill, a hammer mill, a roll mill, a roller mill, a media mill, a media stirring mill, and a freeze pulverizer. One type may be used alone, or two or more types may be used in combination.

[0033] Examples of cutting type mills include cutting mills (manufactured by Horai Co., Ltd.), mesh mills (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hyakuma Manufacturing Co., Ltd.), knife mills (manufactured by Palman), cutter mills (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.), centri-cutter (Nippon Coke and Engineering Co., Ltd.), rotary cutter mills (manufactured by Nara Machinery Works, Ltd.), turbo cutters (manufactured by Freund Turbo Corporation), and pulp crushers (manufactured by Zuikou Co., Ltd.).

[0034] Examples of the hammer mill include a hammer mill (manufactured by Hosokawa Micron Corporation), a jaw crusher (manufactured by Makino Corporation), and a hammer crusher (manufactured by Makino Sangyo Co., Ltd.).

[0035] Examples of impact mills include Pulverizer (manufactured by Hosokawa Micron Corporation), Fine Impact Mill (manufactured by Hosokawa Micron Corporation), Super Micron Mill (registered trademark, manufactured by Hosokawa Micron Corporation), Innomizer (registered trademark, manufactured by Hosokawa Micron Corporation), Fine Mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), CUM type centrifugal mill (manufactured by Mitsui Mining Co., Ltd.), Exceed Mill (manufactured by Makino Sangyo Co., Ltd.), Ultraplex (manufactured by Makino Sangyo Co., Ltd.), Contraplex (manufactured by Makino Sangyo Co., Ltd.), Coroplex (manufactured by Makino Sangyo Co., Ltd.), Atomizer (manufactured by Seishin Enterprise Co., Ltd.), Tornado Mill (Nikki Examples of such mills include those manufactured by Nara Sozo Co., Ltd.), Nea Mill (manufactured by Dalton Co., Ltd.), Jiyu Crusher (manufactured by Nara Machinery Works Ltd.), New Cosmomizer (manufactured by Nara Machinery Works Ltd.), Turbo Mill (manufactured by Freund Turbo Corporation), Super Powder Mill (manufactured by Nishimura Machinery Works Ltd.), Blade Mill (manufactured by Nisshin Engineering Inc.), Super Rotor (manufactured by Nisshin Engineering Inc.), Wheeley Crusher (manufactured by Sanki Manufacturing Co., Ltd.), Pulp Crusher (manufactured by Zuikou Co., Ltd.), Jacobson Fine Crusher (manufactured by Kobe Steel Pantech Co., Ltd.), Universal Mill (manufactured by Tokuju Machinery Works Ltd.), and Continuous Vibro Mill (Euras Techno Co., Ltd.).

[0036] Examples of airflow 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 Japan Pneumatic Mfg. Co., Ltd.), Current Jet (manufactured by Nisshin Engineering Inc.), Jet Mill (manufactured by Sansho Industry Co., Ltd.), Selenium Mirror (manufactured by Masuko Sangyo Co., Ltd.), New Micro Sictomat (manufactured by Masuno Seisakusho Co., Ltd.), and Kryptron (manufactured by EarthTechnica Corporation).

[0037] Examples of roller mills include a vertical roller mill (manufactured by Seishin Co., Ltd.), a vertical roller mill (manufactured by Chinon Co., Ltd.), a roller mill (manufactured by Kotobuki Giken Kogyo Co., Ltd.), a VX mill (Kurimoto Iron Works Ltd.), a KVM type vertical roller mill (Earth Technica Corporation), and an IS mill (IHI Plant Engineering Co., Ltd.). Of these, cutting mills and roller mills are preferred.

[0038] The conditions for the pulverization treatment can be appropriately set so as to obtain the desired powdered cellulose. For example, the treatment conditions can be adjusted by referring to a calibration curve prepared from the pulverization conditions (e.g., treatment time, input amount) and the desired physical properties of the powdered cellulose.

[0039] -Neutralization, washing, dehydration, drying process- The cellulose raw material is appropriately pretreated before the pulverization process. Examples of the pretreatment include neutralization, washing, deliquation, and drying, and it is preferable to perform dehydration and drying in this order. The solid content concentration of the cellulose raw material can be adjusted by drying (dehydration) treatment, and the physical properties of the powdered cellulose can be easily controlled. The solid content concentration is usually adjusted to 15% or more, preferably 20% or more. It is preferable to use an airflow dryer for drying. This allows the processed cellulose raw material to be dispersed in an airflow while being exposed to high-speed hot air, regardless of the form of the processed cellulose raw material, such as a cake-like solid, a slurry, or a solution, and the reduced pressure effect inside the dryer can be utilized to dry it instantly. In addition, since the time of contact with the hot air is extremely short, the product temperature can be kept low, making it ideal for drying products that are sensitive to heat or have a low melting point. The conditions for drying using an airflow dryer are not particularly limited and can be set appropriately, but an example is as follows. The outlet drying temperature is usually 80 to 180°C, preferably 90 to 160°C. The amount of air supplied is usually 150 to 350 m 3 / h, preferably 160 to 320 m 3 / h. On the other hand, when using a spray dryer, the material is sprayed and dried instantly with hot air to produce granules. Therefore, it is often not suitable for drying solid or semi-solid objects with low moisture content, and the particles are more likely to be exposed to high heat instantaneously than when drying with an airflow dryer, which may affect the product.

[0040] -Acid hydrolysis treatment- Examples of the acid used in 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 viewpoint of maintaining the degree of polymerization and whiteness, it is preferably lower than the acid concentration in the acid hydrolysis treatment for the conventional production of powdered cellulose, more preferably 0.4 to 2.0N, and more preferably 0.5 to 1.5N. If the acid concentration is less than 0.4N, the depolymerization of cellulose by the acid is suppressed and the decrease in the degree of polymerization of cellulose can be reduced, but it may be difficult to finely pulverize the cellulose. On the other hand, if the acid concentration exceeds 2.0N, the depolymerization of cellulose progresses and finely pulverization becomes easier, so that the powder flowability improves, but the tablet hardness decreases with the decrease in the degree of polymerization (it may become easily disintegrated when molded). 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.

[0041] Prior to the acid hydrolysis treatment, the cellulose raw material may be pretreated. For example, the cellulose raw material may be slurried (prepared as a dispersion liquid) and the concentration of the cellulose raw material may be adjusted. The concentration of the cellulose raw material is usually 3 to 10% by weight (solid content equivalent) relative to the dispersion liquid. When the cellulose raw material is a fluid pulp that has been bleached, a treatment to increase the pulp concentration is usually performed before hydrolysis. A dehydrator such as a screw press or a belt filter may be used to adjust (concentrate) the concentration of the cellulose raw material. The acid hydrolysis treatment may be performed on a slurry of the cellulose raw material, or on a sheet-like cellulose raw material. When the cellulose raw material is a dry sheet of pulp, the pulp is usually loosened before the acid hydrolysis treatment. A crusher such as a roll crusher may be used to loosen the pulp.

[0042] In the pulverization treatment after acid hydrolysis, at least one other component (e.g., organic component, inorganic component) may be subjected to the pulverization treatment together with the acid hydrolysis product, if necessary. This can impart functionality to the powdered cellulose or improve its functionality. The amount of the other components to be blended may be appropriately selected. Furthermore, prior to the pulverization step, the acid hydrolysis product may be subjected to the above-mentioned neutralization, washing, dehydration, and drying treatments.

[0043] The powdered cellulose may be chemically treated as necessary. The chemical treatment is preferably a treatment that does not significantly impair the degree of polymerization of the cellulose raw material. The chemical treatment may be performed when the cellulose raw material is subjected to a crushing treatment, or may be performed before a pretreatment for the crushing treatment.

[0044] [4. Uses of powdered cellulose] Other uses of powdered cellulose include, for example, industrial additives (for resins such as polypropylene, phenolic resins, and melamine resins, and for various rubbers). It can also be used as a component or raw material for resin compositions (for example, polyolefin resins, modified polyolefin resins, and rubbers), rubber compositions (for example, automobiles, personal computers, building materials, and containers), food additives (for example, shredded cheese, fried products, bread crumbs, ham and sausage casings, and their pickling liquids), sanitary products / cosmetics (for example, facial cleansers, dentifrices, and foundations), filter aids (for example, rare metals, and food), paint / adhesive additives (for example, urethane paints), and feed (for example, pet food and fishing bait). EXAMPLES

[0045] The present invention will be described below with reference to examples. The following examples are not intended to limit the present invention. The test methods used in the examples of the present application are as follows. The methods for measuring physical properties and the like are the same as those described above unless otherwise specified.

[0046] <Average particle size> A laser diffraction particle size distribution measuring device (Mastersizer 3000, Malvern Panalytical Division, Spectris) was used. The particle size distribution was measured by wet measurement (with ultrasonic irradiation) using the laser scattering method as the measurement principle. When the particle size distribution is expressed as a volume accumulation distribution, the values ​​at which the integrated value of the volume accumulation distribution is 10%, 50%, and 90% were defined as the particle size distribution D.10, D.50, and D.90, respectively. The wet D.50 (with ultrasonic irradiation) was defined as the average particle size.

[0047] Wet measurements were performed by adding a sample to the measurement section in water stirred at 3000 rpm so that the scattering intensity was about 10%. When irradiating ultrasonic waves, ultrasonic waves were applied to the sample in water under the following conditions before wet measurements were performed. Mode: Continuous ·Strength: 100% Time: 600 seconds

[0048] The particle size distribution analysis was performed under the following conditions for all measurement conditions. Analysis: General purpose Analysis Sensitivity: Emphasis Light scattering model: Mie theory

[0049] <Average fiber length (μm), average fiber width (μm), L / D> The measurement was carried out using an L&W Fiber Tester Plus (manufactured by ABB) according to the following procedure. 0.1 g of the sample was placed in a cylinder containing 200 ml of pure water, stirred for about 1 minute, then transferred to a dedicated 300 ml beaker, set in a sample cycler, and measurement was started. Measurements were continued until more than 55,000 fibers with a fiber length of 0.1 mm or more were counted, and the length-weighted fiber length and width-weighted fiber width were obtained, which were taken as the average fiber length and average fiber width of the powdered cellulose. Note that the measurement was performed after setting the Max value of Fines Limit to 0.0 and the Min value of Length class 1 to 0.0 on the Sample type screen, which determines the measurement conditions. L / D was calculated from the obtained average fiber length and average fiber width.

[0050] <ndf> 3 g of sample was placed in an aluminum weighing dish, dried at 135°C for 2 hours, cooled in a desiccator, weighed, and the moisture content of the sample was calculated. 18.6 g of disodium dihydrogen ethylenediaminetetraacetate dihydrate, 6.8 g of sodium borate decahydrate, and 4.6 g of disodium hydrogen phosphate were weighed and placed in a 1L volumetric flask, and 500 mL of water was added to dissolve. 30.0 g of sodium n-dodecyl sulfate, 10 mL of triethylene glycol, and 250 mL of water were added to this solution and mixed, and then water was added up to the mark on the volumetric flask to prepare a neutral detergent solution. 0.5 g of sample was placed in a 500 mL tall beaker, 0.5 g of sodium sulfite and 50 mL of neutral detergent solution were added, and the tall beaker was covered with a watch glass or a cooler and heated to boiling in a preheated fiber boiling device. After boiling for 1 hour while supplementing the evaporated water, the tall beaker was removed from the fiber boiling apparatus, and the contents of the tall beaker were suction filtered through a glass filter (P2, FossTecator, pore size 50 μm). The residue in the glass filter (neutral detergent insolubles) was washed with hot water, further washed with acetone, and then air-dried until the acetone odor disappeared. Next, the glass filter was dried at 135 ° C for 2 hours, cooled in a desiccator, and the weight of the neutral detergent insolubles was weighed. The glass filter was further heated at 520 ° C for 3 hours to incinerate the neutral detergent insolubles, heated at 150 ° C for 2 hours, cooled in a desiccator, and the weight of the ash was accurately weighed. The amount of ash was subtracted from the amount of the neutral detergent insolubles described above to calculate the NDF (% of dry matter) in the sample.

[0051] <adf> 3 g of sample was placed in an aluminum weighing dish, dried at 135°C for 2 hours, and cooled in a desiccator, then weighed, and the moisture content in the sample was calculated. 20 g of cetyltrimethylammonium bromide was added to 1 L of sulfuric acid (1+37) and dissolved to prepare an acid detergent solution. 1 g of sample was placed in a 500 mL tall beaker, 100 mL of acid detergent solution was added, and the tall beaker was covered with a watch glass or a cooler and boiled. After boiling for 1 hour while supplementing the evaporating moisture, the contents of the tall beaker were suction filtered with a glass filter (P2, FossTecator, pore size 50 μm). The residue in the glass filter (acid detergent insoluble matter) was washed with hot water, further washed with acetone, and then air-dried until the acetone odor disappeared. Next, the glass filter was dried at 135°C for 2 hours, cooled in a desiccator, and the weight of the acid detergent insoluble matter was accurately weighed. The glass filter was then heated at 520°C for 3 hours to convert the acid detergent insoluble matter into incinerated matter, and then heated at 150°C for 2 hours. After cooling in a desiccator, the weight of the ash was accurately measured. The ADF (% of dry matter) in the sample was calculated by subtracting the amount of ash from the amount of acid detergent insoluble matter obtained above.

[0052] <Hemicellulose content> The amount of hemicellulose was calculated as the difference between the above NDF and ADF.

[0053] <Thermogravimetric reduction rate> The thermal weight loss rate was calculated by measuring the weight of powdered cellulose at 110°C and 300°C when the temperature was raised from 35°C to 550°C at 20°C / min in a nitrogen atmosphere using a thermal analyzer (TGA Q50, TA Instruments Japan, Inc.), and calculating the rate of change as the thermal weight loss rate (%). 5 to 15 g of powdered cellulose was weighed onto a platinum pan and the measurement was performed. Thermal weight loss rate (%) = 100 x (weight at 1-300°C / weight at 110°C)

[0054] <Color (resin composition)> A resin composition containing powdered cellulose was prepared as follows. Powdered cellulose, polypropylene resin (BC10HRF, manufactured by Japan Polypropylene Corporation), and maleic anhydride modified polypropylene (UMEX 1010, manufactured by Sanyo Chemical Industries, Ltd.) were weighed out in a ratio of 51:48.5:0.5 to a total of 8 g, and eight batches were prepared. Each 8 g of the weighed material was put into a small molding machine ("MC15" manufactured by Xplore Instruments), kneaded for 5 minutes at a heating barrel (cylinder) temperature of 200°C, and eight rectangular test pieces (JIS K7139) were molded under the condition of a mold temperature of 40°C. The first three were discarded, and the remaining five were used for color evaluation. The CIE L of the rectangular test pieces was measured using a spectrophotometer (eXact, manufactured by Videojet X-Rite Inc.). * , a * , b * Measure at three points on each test piece, and the average value is the L of that test piece. * , a * , b * The illuminant during the measurement was D50, the observation field was 2°, the density status was T, and the measurement conditions were M. 0 (N 0 ) No filter was selected. This measurement was performed on a total of five test pieces, and the average value of n=5 was calculated as the L * , a * , b * The saturation of the sample C * , color difference ΔE with polypropylene alone * The L value of the polypropylene alone used (the larger the value, the greater the discoloration) was calculated according to the following formula. * , a * , b * are L * 0 , a * 0 , b * 0 And L * 0 is 52.3, a * 0 is -1.0, b * 0 was -2.4. TIFF2025074677000001.tif16160 TIFF2025074677000002.tif11160 In the present invention, L * is 40 or more, and C * is 18 or more, and ΔE * If the value is between 21 and 30, the color is considered to be natural, derived from the wood.

[0055] <Preparation of powdered cellulose> Example 1 Using a bleached kraft pulp sheet (LBKP dry sheet, Nippon Paper Industries Co., Ltd., moisture content 7%) derived from hardwood as the raw material, the sheet was coarsely crushed in a uniaxial crusher and then primarily crushed in a vertical roller mill (Hatsuratsu Co., Ltd.) at a feed rate of 30 kg / h, a classifier frequency of 22 Hz, and a crushing roller frequency of 55 Hz, and then secondary crushed in the same device at a feed rate of 50 kg / h, a classifier frequency of 43 Hz, and a crushing roller frequency of 55 Hz, and the crushed product obtained was used as the powdered cellulose of Example 1. Various physical property values ​​are shown in Table 1.

[0056] Comparative Example 1 A bleached kraft pulp sheet (NBKP dry sheet, Nippon Paper Industries Co., Ltd., moisture content 10%) derived from coniferous trees was used as the raw material, and the sheet was coarsely crushed in a uniaxial crusher, and then treated in a vertical roller mill (Hatsuratsu Co., Ltd.) in the same manner as in Example 1, except that the feed rate for the primary crushing was 30 kg / h, the classifier frequency was 14 Hz, and the feed rate for the secondary crushing was 45 kg / h, and the classifier frequency was 28 Hz. The resulting crushed product was used as the powdered cellulose of Comparative Example 1. Various physical property values ​​are shown in Table 1.

[0057] Comparative Example 2 A bleached dissolving kraft pulp sheet derived from hardwood (LDKP dry sheet, Nippon Paper Industries Co., Ltd., moisture content 10%) was used and coarsely pulverized with a cutting mill (PI-20120, Horai Co., Ltd., screen diameter Φ3 mm), and then pulverized with a cutting mill (HA8-2542, Horai Co., Ltd., main mesh: 165 mesh, auxiliary mesh: 20 mesh), and the pulverized material obtained was used as the powdered cellulose of Comparative Example 2. Various physical property values ​​are shown in Table 1.

[0058] Comparative Example 3 A bleached sulfite pulp sheet derived from hardwood (LDPT dry sheet, Nippon Paper Industries Co., Ltd., moisture content 7.5%) was used as the raw material, and the powdered cellulose obtained by treating in the same manner as in Example 2, except that the mesh during pulverization in a cutting mill (HA8-2542) was 100 mesh, was used as the powdered cellulose of Comparative Example 3. Various physical property values ​​are shown in Table 1.

[0059] [Table 1]

[0060] Example 1, in which the hemicellulose amount and the thermal weight loss rate were within the prescribed ranges, had a natural color derived from wood when made into a resin composition, compared to Comparative Examples 1 to 3, in which the hemicellulose amount and the thermal weight loss rate were outside the ranges.< / adf> < / ndf>

Claims

1. The powdered cellulose has an average particle size of 10 to 100 μm, a hemicellulose content of 10 to 30% by weight when the powdered cellulose is taken as 100% by weight, and a thermal weight loss rate of 4 to 15% at 110° C. to 300° C. when heated at 20° C. / min in a thermal analyzer (TG).

2. The powdered cellulose according to claim 1, having an average fiber length / average fiber width (L / D) of 2.0 to 10.

0.

3. 2. The powdered cellulose according to claim 1, wherein the raw pulp is pulp derived from hardwood.

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