Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/12—Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
  • B29C64/30—Auxiliary operations or equipment
  • B29C64/307—Handling of material to be used in additive manufacturing
  • B29C64/314—Preparation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
  • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/02—Cellulose; Modified cellulose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L53/02—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers of vinyl-aromatic monomers and conjugated dienes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
  • C08L71/02—Polyalkylene oxides

Definitions

• the present invention relates to a resin composition containing a styrene-based elastomer.
• thermoplastic elastomers have traditionally been used in a wide range of applications because, while exhibiting rubber elasticity, they can be melt molded using techniques similar to those used for thermoplastic resins.
• Known thermoplastic elastomers include styrene-based, olefin-based, polyurethane-based, polyester-based, polyamide-based, acrylic-based, and polyvinyl chloride-based elastomers. Of these, styrene-based elastomers have excellent weather resistance and chemical resistance, and are therefore used as sealing materials, etc., as well as modifiers and additives for various materials.
• the resin composition contains a styrene-based elastomer as the thermoplastic elastomer, Item 16.
• the resin composition contains an acid-modified styrene-based elastomer as the thermoplastic elastomer, Item 17.
• the resin composition contains, as the thermoplastic elastomer, an acid-modified styrene-based elastomer and a styrene-based elastomer, Item 20.
• the resin composition according to any one of items 1 to 19, wherein the number average molecular weight of the acid-modified styrene-based elastomer is 10,000 to 500,000, and the number average molecular weight of the styrene-based elastomer is 10,000 to 500,000.
• the resin composition contains an acid-modified styrene-based elastomer as the thermoplastic elastomer, 21.
• the resin composition contains an acid-modified styrene-based elastomer as the thermoplastic elastomer, 22.
• the resin composition according to any one of the preceding claims further comprising a liquid polymer.
• Item 29 Item 29.
• Item 28 A resin molded product obtained by molding the resin composition according to any one of items 1 to 27.
• Item 31 Item 31.
• Item 33 Item 28.
• a 3D printing modeling material comprising the resin composition according to any one of items 1 to 27.
• Item 34 Item 34.
• the 3D printing modeling material according to item 33 having the form of a filament or powder.
• Item 35 Item 28.
• a molded object obtained by molding the resin composition according to any one of items 1 to 27 using a 3D printer.
• Item 36 Item 35.
• a 3D printing material according to item 33 or 34 which is shaped by a 3D printer.
• a method for manufacturing a shaped object comprising the steps of: 28.
• a method comprising a step of modeling the resin composition according to any one of items 1 to 27 using a 3D printer.
• thermoplastic elastomer a thermoplastic elastomer and cellulose nanofibers.
• the amount of the thermoplastic elastomer in 100% by mass of the resin composition is 60% by mass or more.
• adding cellulose nanofibers to styrene-based elastomers can be advantageous in reducing shrinkage during molding, and in improving the tensile strength, tensile modulus, tensile elongation at break, and/or hardness of the molded body. It has been found that in the resin composition according to one embodiment, the presence of acid-modified styrene-based elastomers in addition to cellulose nanofibers can further improve the tensile strength, tensile modulus, tensile elongation at break, and/or hardness of the molded body, and can reduce disadvantages such as whitening and coloring of the molded body.
• the resin composition according to one embodiment is excellent in processability and handling while using a styrene-based elastomer that is excellent in rubber elasticity, weather resistance, chemical resistance, etc., and has a favorable physical property improvement effect due to the cellulose nanofiber, and further has little inconvenience such as whitening and coloring, making it suitable, for example, as a substitute for thermoplastic polyurethane elastomer (TPU).
• TPU thermoplastic polyurethane elastomer
• One aspect of the present invention also provides a resin composition comprising a styrene-based elastomer and a tack inhibitor containing cellulose nanofibers.
• styrene-based elastomers inherently have good rubber elasticity, weather resistance, chemical resistance, etc., due to their tackiness, molding is difficult and the molded body tends to be difficult to handle.
• a molding material having tackiness is difficult to separate from a mold during molding, and when a molded body is peeled off from the mold by applying a strong force, it is deformed and broken, making it difficult to obtain a good molded body.
• cellulose nanofibers have an excellent effect of reducing the tackiness of styrene-based elastomers is unclear, but the fine fibrous structure of cellulose nanofibers makes them more likely to physically intertwine with styrene-based elastomers than other fillers (e.g., silica particles, glass fibers, carbon fibers, etc.), which may result in a good tackiness reduction effect.
• Cellulose nanofibers are softer than, for example, silica particles, glass fibers, carbon fibers, etc., and therefore are advantageous in that they do not impair the rubber elasticity inherent to styrene-based elastomers.
• the resin composition according to one embodiment has a tack strength (hereinafter sometimes simply referred to as tack strength) of 10.0 gf/mm 2 or less at 23°C, a load of 600 gf, a pressure time of 60 seconds, and a peeling speed of 600 mm/min, as measured by a probe tack test.
• the tack strength may be 9.0 gf/mm 2 or less, or 7.0 gf/mm 2 or less, or 5.0 gf/mm 2 or less, or 3.0 gf/mm 2 or less, or 2.0 gf/mm 2 or less, or 1.5 gf/mm 2 or less, or 1.0 gf/mm 2 or less.
• the tack strength of the resin composition according to one embodiment is preferably 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 25% or less, or 20% or less, or 15% or less, or 10% or less, relative to the tack strength of a resin composition having the same composition but not containing cellulose nanofibers (100%).
• the above ratio is preferably small from the viewpoint of suppressing tack, but from the viewpoint of ease of production of the resin composition, in one embodiment, it may be 0.0001% or more, or 0.1% or more, or 1% or more, or 3% or more. It is also preferable that the tack strength of the resin composition according to one embodiment shows the above-mentioned exemplary ratio with respect to 100% of the tack strength of the styrene-based elastomer contained in the resin composition.
• Regenerated cellulose can be regenerated cellulose fibers (viscose, cupra, tencel, etc.), cellulose derivative fibers, and ultrafine threads of regenerated cellulose or cellulose derivatives obtained by electrospinning.
• Cellulose fiber raw materials that give cellulose nanofibers with fluff on the surface may be advantageous in terms of tack suppression effect. From this viewpoint, preferred cellulose fiber raw materials include cotton linters, etc.
• defibration is a dry or wet mechanical treatment, preferably a wet treatment in which mechanical treatment is applied to a slurry obtained by dispersing cellulose fiber raw material in a liquid medium.
• a single device may be used once or more than once, or multiple devices may each be used once or more than once.
• the number average fiber length L of the cellulose nanofibers is preferably 100 nm or more, or 500 nm or more, 1 ⁇ m or more, or 5 ⁇ m or more, or 10 ⁇ m or more, or 20 ⁇ m or more, from the viewpoint of satisfactorily expressing the physical property improving effect of the cellulose nanofibers, and is preferably 1000 ⁇ m or less, or 800 ⁇ m or less, or 500 ⁇ m or less, or 400 ⁇ m or less, or 300 ⁇ m or less, or 200 ⁇ m or less, from the viewpoint of satisfactorily dispersing the cellulose nanofibers in the resin composition.
• the number average fiber diameter D of the cellulose nanofibers is preferably 2 to 1000 nm from the viewpoint of obtaining a good effect of improving physical properties by the cellulose nanofibers.
• the number average fiber diameter of the cellulose nanofibers is more preferably 4 nm or more, or 5 nm or more, or 10 nm or more, or 15 nm or more, or 20 nm or more, and more preferably 900 nm or less, or 800 nm or less, or 700 nm or less, or 600 nm or less, or 500 nm or less, or 400 nm or less, or 300 nm or less, or 200 nm or less.
• the average fiber length (L)/fiber diameter (D) ratio of the cellulose nanofibers is preferably 30 or more, or 50 or more, or 80 or more, or 100 or more, or 120 or more, or 150 or more, from the viewpoint of effectively improving the mechanical properties of a rubber composite containing cellulose nanofibers with a small amount of cellulose nanofibers.
• the number average aspect ratio which is the ratio L/D of the number average fiber length L to the number average fiber diameter D of the cellulose nanofibers in the resin composition, is, in one embodiment, 2 or more and 26 or less.
• the upper limit of the aspect ratio is not particularly limited, but from the viewpoint of handleability, it is preferably 25 or less.
• the lower limit of the aspect ratio is not particularly limited, but is preferably 5 or more, 10 or more, or 15 or more.
• the aspect ratio is a value measured by the method described in the [Examples] section of this disclosure.
• Known crystalline forms of cellulose include types I, II, III, and IV, of which types I and II are particularly widely used, while types III and IV have been obtained on a laboratory scale but are not widely used on an industrial scale.
• the cellulose nanofibers disclosed herein have relatively high structural mobility, and by dispersing the cellulose nanofibers in rubber, a molded product with a lower linear expansion coefficient and superior strength and elongation during tensile and bending deformation can be obtained. Therefore, cellulose nanofibers containing cellulose type I crystals or cellulose type II crystals are preferred, and cellulose nanofibers containing cellulose type I crystals and having a crystallinity of 55% or more are more preferred.
• the degree of crystallinity of the cellulose nanofiber is preferably 55% or more.
• a more preferable lower limit of the degree of crystallinity is 60%, even more preferably 70%, and most preferably 80%.
• the degree of crystallinity is determined by the following formula using the Segal method from the diffraction pattern (2 ⁇ /deg. is 10 to 30) obtained by measuring a sample by wide-angle X-ray diffraction.
• Crystallinity (%) [I (200) - I (amorphous) ] / I (200) ⁇ 100
• Crystallinity (%) (h0-h1) /h0 ⁇ 100
• the weight average molecular weight (Mw) of the cellulose nanofiber is 100,000 or more, more preferably 200,000 or more.
• the ratio (Mw/Mn) of the weight average molecular weight to the number average molecular weight (Mn) is 6 or less, preferably 5.6 or less, or 5.4 or less. The larger the weight average molecular weight, the fewer the number of terminal groups of the cellulose molecule.
• the ratio (Mw/Mn) of the weight average molecular weight to the number average molecular weight represents the width of the molecular weight distribution, the smaller the Mw/Mn, the fewer the number of terminals of the cellulose molecule.
• the terminals of the cellulose molecules are the starting points of thermal decomposition, when the cellulose molecules of the cellulose nanofibers not only have a large weight average molecular weight but also have a narrow molecular weight distribution, a cellulose nanofiber with particularly high heat resistance and a resin composition containing the cellulose nanofiber can be obtained.
• the weight average molecular weight (Mw) of the cellulose nanofiber may be, for example, 600,000 or less, 500,000 or less, or 400,000 or less.
• Mw/Mn can also be controlled to the above range by selecting a cellulose raw material having an Mw/Mn according to the purpose, appropriately performing physical treatment and/or chemical treatment on the cellulose raw material within an appropriate range, etc.
• Each of the Mw and Mw/Mn of the cellulose raw material may be within the above range in one embodiment.
• the weight-average molecular weight and number-average molecular weight of the cellulose nanofibers referred to here are values determined by dissolving the cellulose nanofibers in N,N-dimethylacetamide containing added lithium chloride, and then performing gel permeation chromatography using N,N-dimethylacetamide as the solvent.
• Alkali-soluble polysaccharides that cellulose nanofibers may contain include hemicellulose, as well as ⁇ -cellulose and ⁇ -cellulose.
• Alkali-soluble polysaccharides are understood by those skilled in the art as components obtained as the alkali-soluble portion of holocellulose obtained by solvent extraction and chlorine treatment of plants (e.g. wood) (i.e., components obtained by removing ⁇ -cellulose from holocellulose).
• Alkali-soluble polysaccharides are polysaccharides that contain hydroxyl groups and have poor heat resistance, which can lead to inconveniences such as decomposition when exposed to heat, yellowing during thermal aging, and a decrease in the strength of cellulose nanofibers. Therefore, it is preferable that the content of alkali-soluble polysaccharides in cellulose nanofibers is low.
• the average content of alkali-soluble polysaccharides in the cellulose nanofibers is preferably 20% by mass or less, or 18% by mass or less, or 15% by mass or less, or 12% by mass or less, relative to 100% by mass of the cellulose nanofibers, from the viewpoint of obtaining good dispersibility of the cellulose nanofibers.
• the above content may be 1% by mass or more, or 2% by mass or more, or 3% by mass or more.
• the average alkali-soluble polysaccharide content can be determined by the method described in the non-patent literature (Wood Science Experiment Manual, edited by the Japan Wood Research Society, pp. 92-97, 2000), by subtracting the ⁇ -cellulose content from the holocellulose content (Wise method). This method is understood in the industry as a method for measuring the amount of hemicellulose. The alkali-soluble polysaccharide content is calculated three times for each sample, and the number average of the calculated alkali-soluble polysaccharide contents is taken as the average alkali-soluble polysaccharide content.
• the average acid-insoluble content is determined by quantifying the acid-insoluble content using the Clason method described in the non-patent literature (Wood Science Experiment Manual, edited by the Japan Wood Research Society, pp. 92-97, 2000). This method is understood in the industry as a method for measuring the amount of lignin.
• the sample is stirred in a sulfuric acid solution to dissolve cellulose, hemicellulose, etc., and then filtered through glass fiber filter paper. The resulting residue corresponds to the acid-insoluble components.
• the acid-insoluble component content is calculated from the weight of this acid-insoluble component.
• the acid-insoluble component content is then measured three times for each sample, and the number average is taken as the average acid-insoluble component content.
• the cellulose nanofiber may be a chemically modified cellulose nanofiber (also referred to as a chemically modified cellulose nanofiber).
• chemically modified cellulose nanofibers include inorganic esters such as nitrate esters, sulfate esters, phosphate esters, silicate esters, and borate esters, organic esters such as acetylation and propionylation, ethers such as methyl ether, hydroxyethyl ether, hydroxypropyl ether, hydroxybutyl ether, carboxymethyl ether, and cyanoethyl ether, and TEMPO oxides obtained by oxidizing the primary hydroxyl groups of cellulose.
• the cellulose nanofibers may be chemically modified with a modifying agent, for example, at the stage of cellulose fiber raw material, during the defibration treatment, or after the defibration treatment, or may be chemically modified during or after the preparation of a slurry as a dispersion, or during or after the drying process.
• a modifying agent for example, at the stage of cellulose fiber raw material, during the defibration treatment, or after the defibration treatment, or may be chemically modified during or after the preparation of a slurry as a dispersion, or during or after the drying process.
• the acyl substitution degree (DS) is preferably 0.1 or more, or 0.2 or more, or 0.25 or more, or 0.3 or more, or 0.5 or more in terms of obtaining esterified cellulose nanofibers with a high thermal decomposition onset temperature, and is preferably 2.0 or less, or 1.8 or less, or 1.5 or less, or 1.2 or less, or 1.0 or less, or 0.8 or less, or 0.7 or less, or 0.6 or less, or 0.5 or less in terms of obtaining esterified cellulose nanofibers having a high thermal decomposition onset temperature because an unmodified cellulose skeleton remains in the esterified cellulose nanofibers.
• H1730 and H1030 are the absorbances at 1730 cm -1 and 1030 cm -1 (absorption bands of C-O stretching vibration of the cellulose backbone chain), respectively, where the lines connecting 1900 cm -1 and 1500 cm -1 and 800 cm -1 and 1500 cm -1 are taken as baselines, and these mean the absorbances when these baselines are taken as absorbance 0.
• the modifying group is an acetyl group
• the signal at 23 ppm assigned to --CH.sub.3 may be used.
• the 1% weight loss temperature (T 1% ) is the temperature at which a 1% weight loss occurs, starting from a weight of 150° C., when the temperature is continued to be raised by the above-mentioned T D method.
• a concentrated cake of cellulose nanofibers with a solid content of 10% by mass or more is added to tert-butanol, and a dispersion process is performed using a mixer or the like until no aggregates are present. The concentration is adjusted to 0.5% by mass per 0.5 g of cellulose nanofiber solid content.
• 100 g of the obtained tert-butanol dispersion is filtered on filter paper. The filtered material is not peeled off from the filter paper, but is sandwiched between two sheets of larger filter paper, and the edges of the larger filter paper are pressed down with a weight and dried in an oven at 150 ° C. for 5 minutes. The filter paper is then peeled off to obtain a porous sheet with little distortion.
• the sheet with an air resistance R of 100 sec/100 ml or less per 10 g/m2 sheet basis weight is used as a porous sheet and is used as a measurement sample.
• the specific surface area of the cellulose nanofiber is preferably 10 m2/g or more, or 15 m2/g or more, or 20 m2 /g or more, or 30 m2 /g or more, or 40 m2 /g or more, or 50 m2/g or more , from the viewpoint of the good color tone of the resin composition due to the highly fine cellulose nanofiber and the good effect of reducing tack to styrene- based elastomers, and is preferably 200 m2 /g or less, or 170 m2 /g or less, or 160 m2 /g or less, from the viewpoint of ease of production and handling of the cellulose nanofiber .
• the specific surface area is measured by drying approximately 0.2 g of a sample under vacuum at 120°C for 5 hours using a specific surface area/pore distribution measuring device (e.g., Nova-4200e, manufactured by Quantachrome Instruments), measuring the amount of nitrogen gas adsorption at the boiling point of liquid nitrogen at five points in the range of relative vapor pressure (P/P0) of 0.05 to 0.2 (multipoint method), and calculating the BET specific surface area ( m2 /g) using the device program.
• a specific surface area/pore distribution measuring device e.g., Nova-4200e, manufactured by Quantachrome Instruments
• the specific surface area of the cellulose nanofiber is preferably 10 m 2 /g or more, or 15 m 2 /g or more, or 20 m 2 /g or more, or 30 m 2 /g or more, or 40 m 2 /g or more, or 50 m 2 /g or more, in view of the excellent transparency of the resin composition due to the highly fine cellulose nanofiber, and is preferably 200 m 2 / g or less, or 170 m 2 /g or less, or 160 m 2 /g or less, in view of the ease of production and handling of the cellulose nanofiber.
• the above range is particularly suitable in the embodiment in which a tack inhibitor containing cellulose nanofiber is used.
• Cellulose nanofibers having a relatively large specific surface area may be advantageous in terms of the tack inhibitor effect.
• the preferred specific surface area is 10 m 2 /g or more, or 20 m 2 /g or more, or 30 m 2 /g or more.
• Various physical properties of the cellulose nanofibers contained in resin compositions, etc. are analyzed by the following methods.
• the polymer component contained in the resin composition or the like is dissolved in an organic or inorganic solvent capable of dissolving the polymer component, the cellulose nanofiber is separated, and the cellulose nanofiber is thoroughly washed with the solvent, after which the solvent is replaced with tert-butanol.
• the cellulose nanofiber tert-butanol slurry is then analyzed using the same measurement method as above, and various physical properties of the cellulose nanofiber in the resin composition are calculated.
• the weight gain of the cellulose nanofibers when they are separated from the resin composition using THF is preferably 190% or more, or 250% or more, or 300% or more, or 350% or more from the viewpoint of interfacial strength between the resin and the cellulose nanofibers, and is preferably 600% or less, or 550% or less, or 500% or less from the viewpoint of suppressing fiber shortening during kneading.
• the weight gain is a value measured by the method described in the [Examples] section of this disclosure.
• the cellulose nanofibers may be provided in the form of a slurry containing a liquid medium, or in the form of a dry body such as particles, a film, or a bulk.
• the liquid medium include water and/or an organic solvent having a boiling point, and the cellulose nanofibers may contain one or more types of medium.
• the liquid medium content in the slurry form is 50% by mass or more, and the liquid medium content in the dry body is less than 50% by mass.
• the liquid medium content is a value measured when heated at 180°C using an infrared heating moisture meter (e.g., product name "MX-50" manufactured by A&D Co., Ltd.).
• the cellulose nanofibers mixed with the styrene-based elastomer are in the form of a dry body.
• the amount of cellulose nanofibers in 100% by mass of the resin composition is preferably 0.1% by mass or more, or 0.3% by mass or more, or 0.4% by mass or more, or 0.5% by mass or more, or 0.7% by mass or more, or 1.0% by mass or more, from the viewpoint of obtaining the advantages of the cellulose nanofibers well, and is preferably 20% by mass or less, or 15% by mass or less, or 10% by mass or less, from the viewpoint of the impact resistance of the resin composition.
• a particularly preferred amount of cellulose nanofiber from the viewpoint of exhibiting a good tack inhibition effect is 0.5% by mass or more, or 0.7% by mass or more, or 1.0% by mass or more.
• the thermoplastic elastomer includes, in one embodiment, a styrene-based elastomer, in one embodiment, an acid-modified styrene-based elastomer, in one embodiment, a styrene-based elastomer and an acid-modified styrene-based elastomer, and in one embodiment, a styrene-based elastomer and an acid-modified styrene-based elastomer.
• the elastomer is, in one embodiment, a substance that is elastic at room temperature (23° C.) (specifically, a natural or synthetic polymer substance).
• conjugated diene monomer examples include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene, and these may be used alone or in combination of two or more.
• Random copolymers include butadiene-styrene random copolymers, isoprene-styrene random copolymers, and butadiene-isoprene-styrene random copolymers.
• the composition distribution of each monomer in the copolymer chain includes completely random copolymers that are close to a statistically random composition, and tapered (gradient) random copolymers with a gradient in composition distribution.
• the bond type of the conjugated diene polymer i.e., the composition of 1,4-bonds, 1,2-bonds, etc., may be uniform or different between molecules.
• the block copolymer may be a copolymer consisting of two or more blocks.
• the block copolymer may be a block copolymer in which a block A of an aromatic vinyl monomer and a block B of a conjugated diene monomer and/or a copolymer of an aromatic vinyl monomer and a conjugated diene monomer constitute a structure such as A-B, A-B-A, or A-B-A-B.
• the boundaries of the blocks do not necessarily need to be clearly distinguished.
• block B is a copolymer of an aromatic vinyl monomer and a conjugated diene monomer
• the aromatic vinyl monomer in block B may be distributed uniformly or in a tapered shape.
• Block B may have a plurality of parts in which the aromatic vinyl monomer is distributed uniformly and/or a plurality of parts in which the aromatic vinyl monomer is distributed in a tapered shape.
• Block B may have a plurality of segments with different aromatic vinyl monomer contents.
• the molecular weights and compositions of the blocks A and B may be the same or different.
• the styrene-based elastomer may be an aromatic vinyl compound-conjugated diene compound block copolymer or a hydrogenated product thereof.
• the block copolymer may be a mixture of two or more types that differ from each other in one or more of the following: bond type, molecular weight, aromatic vinyl compound type, conjugated diene compound type, 1,2-vinyl content or the total amount of 1,2-vinyl content and 3,4-vinyl content, aromatic vinyl compound component content, hydrogenation rate, etc.
• the styrene-based elastomer may be partially or completely hydrogenated.
• the hydrogenation rate of the hydrogenated product is preferably 50% or more, 80% or more, or 98% or more from the viewpoint of suppressing thermal degradation during processing, and is preferably 50% or less, 20% or less, or 0% (i.e., non-hydrogenated product) from the viewpoint of low-temperature toughness.
• Examples of hydrogenated conjugated diene polymers include the hydrogenated conjugated diene polymers exemplified above, and may be, for example, a hydrogenated styrene-butadiene copolymer.
• the styrenic elastomer is not acid-modified. In one embodiment, the styrenic elastomer may be unmodified.
• the acid-modified styrene-based elastomer may be an acid-modified product of the styrene-based elastomer exemplified above.
• the acid-modified styrene-based elastomer means that an acidic functional group is added to the molecular skeleton of the styrene-based elastomer via a chemical bond as an acid-modified group.
• the acidic functional group means a functional group that can react with a basic functional group, etc., and specific examples include a hydroxyl group, a carboxyl group, a carboxylate group, a sulfo group, an acid anhydride group, etc.
• the acid modification rate which is the mass ratio of the acid-modified groups in 100% by mass of the acid-modified styrene-based elastomer, is preferably 0.2% by mass or more, or 0.3% by mass or more, or 0.5% by mass or more, or 1% by mass or more, or 1.5% by mass or more, based on 100% by mass of the acid-modified styrene-based elastomer, from the viewpoint of the void reduction effect due to good affinity with cellulose nanofibers, and is preferably 2.5% by mass or less, or 2.3% by mass or less, or 2% by mass or less, from the viewpoint of affinity with the styrene-based elastomer.
• the acid modification rate is a value obtained by measuring a calibration curve sample in which an acidic substance has been mixed in advance using an infrared absorption spectrometer, and measuring the sample based on a calibration curve that has been created using the characteristic absorption band of the acid.
• the acid-modified styrene-based elastomer is an acid-modified styrene-based elastomer which is an aromatic vinyl compound-conjugated diene compound copolymer (preferably an aromatic vinyl compound-conjugated diene compound block copolymer) or a hydrogenated product thereof.
• acid-modified styrene-based elastomers include elastomers which are modified by grafting an ⁇ , ⁇ -unsaturated dicarboxylic acid or a derivative thereof to an aromatic compound-conjugated diene copolymer (preferably a block copolymer) or a hydrogenated product thereof in the presence or absence of a peroxide.
• ⁇ , ⁇ -unsaturated dicarboxylic acid and derivatives thereof include maleic acid, fumaric acid, maleic anhydride, and fumaric anhydride, and among these, maleic anhydride is particularly preferred.
• the acid-modified styrene-based elastomer is an acid anhydride-modified styrene-based elastomer.
• the styrene-based elastomer is preferably at least one selected from the group consisting of styrene-butadiene block copolymers, styrene-ethylene-butadiene block copolymers, styrene-ethylene-butylene block copolymers, styrene-butadiene-butylene block copolymers, styrene-isoprene block copolymers, styrene-ethylene-propylene block copolymers, styrene-isobutylene block copolymers, hydrogenated styrene-butadiene block copolymers, hydrogenated styrene-ethylene-butadiene block copolymers, hydrogenated styrene-butadiene-butylene block copolymers, hydrogenated hydrogenated styrene-butadiene-butylene block copolymers, hydrogenated styrene-but
• the styrene unit ratio of the acid-modified styrene-based elastomer and the unit ratio of the styrene-based elastomer are preferably 10% by mass or more, or 19% by mass or more, or 29% by mass or more, respectively, from the viewpoint of the affinity between the acid-modified styrene-based elastomer and the styrene-based elastomer, and from the viewpoint of well expressing the advantageous properties inherent to the styrene-based elastomer, and are preferably 45% by mass or less, or 40% by mass or less, or 35% by mass or less, respectively, from the viewpoint of hardness.
• the styrene unit ratio is a value obtained by the following method. Specifically, a predetermined amount of elastomer is dissolved in chloroform, and measured with an ultraviolet spectrophotometer (e.g., Shimadzu Corporation, UV-2450), and the content of aromatic vinyl monomer units (styrene) is calculated using a calibration curve from the peak intensity of the absorption wavelength (262 nm) due to the aromatic vinyl compound component (styrene).
• an ultraviolet spectrophotometer e.g., Shimadzu Corporation, UV-2450
• the styrene unit ratio of the acid-modified styrene-based elastomer and the unit ratio of the styrene-based elastomer are preferably 10 mol% or more, or 15 mol% or more, or 20 mol% or more from the viewpoint of affinity between the acid-modified styrene-based elastomer and the styrene-based elastomer and from the viewpoint of well expressing advantageous properties inherent to the styrene-based elastomer, and are preferably 40 mol% or less, or 35 mol% or less, or 30 mol% or less, or 25 mol% or less from the viewpoint of flexibility of the composition.
• These unit ratios are suitable in an embodiment using a tack inhibitor containing cellulose nanofibers.
• the styrene unit ratio is a value determined by an NMR method.
• the ratio of the styrene unit ratio to the acid modification rate is preferably 5 or more, or 10 or more, or 20 or more from the viewpoint of affinity with the styrene-based elastomer, and is preferably 90 or less, or 85 or less, or 80 or less from the viewpoint of affinity with the cellulose nanofiber.
• the amount of vinyl bonds (e.g., 1,2- or 3,4-bonds of butadiene) in the conjugated diene bond units in the conjugated diene-based polymer is preferably 5 mol % or more, or 10 mol % or more, or 13 mol % or more, or 15 mol % or more, and is preferably 80 mol % or less, or 75 mol % or less, or 65 mol % or less, or 50 mol % or less, or 40 mol % or less.
• the amount of vinyl bonds in the conjugated diene bond units (for example, the amount of 1,2-bonds in butadiene) can be determined by 13 C-NMR (quantitative mode). That is, by integrating the peak areas shown below in 13 C-NMR, a value proportional to the carbon amount of each structural unit can be obtained, which can then be converted into the mass % of each structural unit.
• the amount of aromatic vinyl monomer bonded to the conjugated diene monomer may be preferably 5.0% by mass or more and 70% by mass or less, or 10% by mass or more and 50% by mass or less, based on the total mass of the styrene-based elastomer.
• the aromatic vinyl bond amount can be determined by the ultraviolet absorbance of the phenyl group, and the conjugated diene bond amount can also be determined based on this.
• the number average molecular weight (Mn) of the acid-modified styrene-based elastomer is preferably 10,000 or more, or 30,000 or more, or 50,000 or more, from the viewpoint of affinity with the styrene-based elastomer, and is preferably 500,000 or less, or 250,000 or less, or 200,000 or less, from the viewpoint of affinity with the cellulose nanofiber.
• the number average molecular weight (Mn) of the styrene-based elastomer is preferably 10,000 to 500,000, or 40,000 to 250,000, from the viewpoint of achieving both impact strength and fluidity.
• the total amount of the acid-modified styrene-based elastomer and the styrene-based elastomer in 100% by mass of the resin composition is 60% by mass or more, or 65% by mass or more, or 70% by mass or more, or 75% by mass or more.
• Such a resin composition can exhibit good rubber elasticity, weather resistance, chemical resistance, etc.
• the above total amount is 90% by mass or less, or 85% by mass or less, or 80% by mass or less, from the viewpoint of containing the desired amount of other components, particularly cellulose nanofibers.
• the amount of acid-modified styrene-based elastomer per 100 parts by mass of styrene-based elastomer is preferably 0.5 parts by mass or more, or 1 part by mass or more, or 5 parts by mass or more from the viewpoints of improving the surface smoothness of the molded body, whitening resistance when the molded body is stretched (suppression of void generation), etc., and is preferably 50 parts by mass or less, or 40 parts by mass or less, or 30 parts by mass or less from the viewpoints of suppressing discoloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• the amount of the acid-modified styrene-based elastomer per 1 part by mass of cellulose nanofiber is preferably 0.5 parts by mass or more, or 1 part by mass or more, or 5 parts by mass or more from the viewpoints of improving the surface smoothness of the molded body, whitening resistance when the molded body is stretched (suppression of void generation), etc., and is preferably 45 parts by mass or less, or 40 parts by mass or less, or 35 parts by mass or less, or 30 parts by mass or less from the viewpoint of suppressing coloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• the amount of acid-modified styrene-based elastomer present in the resin composition may be advantageous to minimize the amount of acid-modified styrene-based elastomer present in the resin composition to the extent that the desired affinity with the cellulose nanofibers is obtained. From this viewpoint, it is preferable to adjust the amount of acid-modified styrene-based elastomer so that it is not excessive relative to the number of hydroxyl groups in the cellulose nanofibers, and the upper limit amount exemplified above is suitable from this viewpoint.
• the amount of acid-modified styrene-based elastomer in 100% by mass of the resin composition is preferably 0.5% by mass or more, or 1% by mass or more, or 5% by mass or more from the viewpoints of improving the surface smoothness of the molded body, whitening resistance when the molded body is stretched (suppression of void generation), etc., and is preferably 50% by mass or less, or 40% by mass or less, or 30% by mass or less from the viewpoints of suppressing discoloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• acid-modified styrene-based elastomers are generally relatively expensive, so it is advantageous in terms of cost to use a smaller amount.
• the behavior of the stress-strain curve (e.g., yield behavior) in a tensile test of the resin composition may be controlled according to the desired application of the resin composition by selecting the type and/or amount of the acid-modified styrene-based elastomer.
• the amount of styrene-based elastomer in 100% by mass of the resin composition is preferably 10% by mass or more, or 20% by mass or more, or 30% by mass or more, from the viewpoint of effectively exerting the advantageous properties inherent to the styrene-based elastomer, and is preferably 98.8% by mass or less, or 90% by mass or less, or 80% by mass or less, from the viewpoint of containing the desired amounts of other components.
• the resin composition contains an acid-modified styrene-based elastomer.
• reaction between the hydroxyl groups of the cellulose nanofibers and the acid-modified groups of the acid-modified styrene-based elastomer strengthens the interface between them, making it difficult for peeling to occur between the styrene-based elastomer, cellulose nanofiber, and acid-modified styrene-based elastomer when an external force is applied to the molded body, and making it difficult for coloring to occur due to thermal degradation of the cellulose nanofibers.
• the physical property improving effect of the cellulose nanofibers is well exhibited, and the occurrence of voids in the molded body due to peeling is suppressed, reducing whitening, and further suppressing coloring of the cellulose nanofibers.
• the presence of an acid-modified styrene-based elastomer in the resin composition is also advantageous in terms of further reducing tackiness caused by the styrene-based elastomer.
• the acid-modified styrene-based elastomer and the styrene-based elastomer are compatible with each other without phase separation, and form a continuous phase.
• the acid-modified styrene-based elastomer forms a first phase
• the styrene-based elastomer forms a second phase that is phase-separated from the first phase.
• the total amount of the acid-modified styrene-based elastomer and the styrene-based elastomer is 60 mass% or more in 100 mass% of the resin composition.
• the second phase is a continuous phase.
• the styrene-based elastomer portion in the resin composition contributes to the expression of the good properties inherent to the styrene-based elastomer, while the acid-modified styrene-based elastomer portion in the resin composition is interposed between the styrene-based elastomer and the cellulose nanofiber due to its good affinity with both the styrene-based elastomer and the cellulose nanofiber, contributing to further improving the physical property improvement effect of the cellulose nanofiber.
• the acid-modified styrene-based elastomer may be an acid-modified product of the styrene-based elastomer exemplified above. Suitable examples of the acid-modified styrene-based elastomer are as exemplified above in this disclosure.
• the amount of styrene-based elastomer per 1 part by mass of cellulose nanofiber is preferably 0.5 parts by mass or more, or 1 part by mass or more, or 3 parts by mass or more, or 5 parts by mass or more, or 7 parts by mass or more, or 10 parts by mass or more, or 15 parts by mass or more, from the viewpoint of obtaining the good rubber elasticity, weather resistance, and chemical resistance inherent to styrene-based elastomers, and is preferably 250 parts by mass or less, or 150 parts by mass or less, or 100 parts by mass or less, from the viewpoint of reducing tackiness and improving hardness of the molded body.
• the amount of styrene-based elastomer in 100% by mass of the resin composition is preferably 10% by mass or more, or 20% by mass or more, or 40% by mass or more, or 50% by mass or more, or 60% by mass or more, or 70% by mass or more, or 80% by mass or more, from the viewpoint of obtaining the inherent advantages of the styrene-based elastomer, and is preferably 99.5% by mass or less, or 99% by mass or less, or 98% by mass or less, or 95% by mass or less, or 90% by mass or less, from the viewpoint of containing the desired amounts of other components.
• the melt mass flow rate (MFR) of the styrene-based elastomer at 230°C and 2.16 kg is preferably 20 g/10 min or less, or 15 g/10 min or less, or 10 g/10 min or less, or 8 g/10 min or less, or 5 g/10 min or less, from the viewpoint of obtaining good mechanical properties of the resin composition, and is preferably 0.1 g/10 min or more, or 0.5 g/10 min or more, or 1.0 g/10 min or more, from the viewpoint of easy melt processing.
• the acid modification rate which is the mass ratio of acid-modified groups in 100% by mass of acid-modified styrene-based elastomer, is preferably 0.2% by mass or more, or 0.5% by mass or more, or 0.8% by mass or more, or 1.0% by mass or more, or 1.2% by mass or more, or 1.5% by mass or more, based on 100% by mass of acid-modified styrene-based elastomer, from the viewpoint of affinity with cellulose nanofibers, and is preferably 5.0% by mass or less, or 3.0% by mass or less, or 2.5% by mass or less, or 2.0% by mass or less, from the viewpoint of affinity with styrene-based elastomers.
• the ratio of the styrene unit ratio of the styrene elastomer to the styrene unit ratio of the acid-modified styrene elastomer is preferably 0.3 or more, or 0.35 or more, or 0.4 or more, from the viewpoint of the affinity between the acid-modified styrene elastomer and the styrene elastomer, and from the same viewpoint, is preferably 4 or less, or 3 or less, or 2 or less.
• the ratio of the styrene unit ratio to the acid modification rate is preferably 5 or more, or 8 or more, or 12 or more from the viewpoint of affinity with the styrene-based elastomer, and is preferably 90 or less, or 50 or less, or 30 or less from the viewpoint of affinity with the cellulose nanofiber.
• the melt mass flow rate (MFR) of the acid-modified styrene-based elastomer at 230°C and 2.16 kg is preferably 0.1 g/10 min or more, or 0.5 g/10 min or more, or 1.0 g/10 min or more, from the viewpoint of affinity with the styrene-based elastomer, and is preferably 20 g/10 min or less, or 15 g/10 min or less, or 10 g/10 min or less, or 8 g/10 min or less, or 5 g/10 min or less, from the viewpoint of affinity with the cellulose nanofiber.
• the total amount of the acid-modified styrene-based elastomer and the styrene-based elastomer in 100% by mass of the resin composition is 50% by mass or more, or 60% by mass or more, or 70% by mass or more, or 80% by mass or more.
• a resin composition can exhibit good rubber elasticity, weather resistance, chemical resistance, etc.
• the above total amount is 99.5% by mass or less, or 99% by mass or less, or 98% by mass or less, or 95% by mass or less, or 90% by mass or less, from the viewpoint of containing a desired amount of other components, particularly cellulose nanofibers.
• the amount of acid-modified styrene-based elastomer per 100 parts by mass of styrene-based elastomer is preferably 0.5 parts by mass or more, or 1 part by mass or more, or 5 parts by mass or more, from the viewpoint of obtaining the advantages of the acid-modified styrene-based elastomer well, and is preferably 100 parts by mass or less, or 50 parts by mass or less, or 20 parts by mass or less, or 10 parts by mass or less, from the viewpoint of suppressing discoloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• the amount of acid-modified styrene-based elastomer per 1 part by mass of cellulose nanofiber is preferably 0.1 parts by mass or more, or 0.3 parts by mass or more, or 0.5 parts by mass or more, or 0.8 parts by mass or more, from the viewpoint of obtaining the advantages of the acid-modified styrene-based elastomer well, and is preferably 45 parts by mass or less, or 30% by mass or less, or 20 parts by mass or less, or 10 parts by mass or less, or 5 parts by mass or less, or 3 parts by mass or less, or 2 parts by mass or less, from the viewpoint of suppressing discoloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• the amount of acid-modified styrene-based elastomer in 100% by mass of the resin composition is preferably 0.5% by mass or more, or 1% by mass or more, or 2% by mass or more, or 3% by mass or more, or 4% by mass or more, from the viewpoint of obtaining the advantages of the acid-modified styrene-based elastomer well, and is preferably 50% by mass or less, or 30% by mass or less, or 20% by mass or less, or 10% by mass or less, from the viewpoint of suppressing discoloration, shrinkage during molding, and/or reduction in hardness caused by a large amount of acid-modified styrene-based elastomer.
• acid-modified styrene-based elastomers are generally relatively expensive, and it is advantageous in terms of cost to use a smaller amount.
• the content of the styrene-based elastomer in the resin composition components is preferably 10% by mass or more, or 20% by mass or more, and preferably 90% by mass or less, or 85% by mass or less, or 80% by mass or less.
• the total content of the styrene-based elastomer and the acid-modified styrene-based elastomer in the resin composition components is preferably 40% by mass or more, or 45% by mass or more, or 50% by mass or more, and preferably 99% by mass or less, or 95% by mass or less, or 90% by mass or less.
• the content of the acid-modified styrene-based elastomer relative to a total of 100 parts by mass of the styrene-based elastomer and the acid-modified styrene-based elastomer is preferably 5 parts by mass or more, or 10 parts by mass or more, or 15 parts by mass or more, and preferably 70 parts by mass or less, or 65 parts by mass or less, or 60 parts by mass or less.
• the amount of cellulose nanofibers in the resin composition components is preferably 1 part by mass or more, or 2 parts by mass or more, or 3 parts by mass or more, and preferably 70 parts by mass or less, or 65 parts by mass or less, or 60 parts by mass or less, per 100 parts by mass of the total of the styrene-based elastomer and the acid-modified styrene-based elastomer.
• the mass ratio of [cellulose nanofiber]/[total of styrene-based elastomer and acid-modified styrene-based elastomer] in the resin composition components is preferably 1/99 to 60/40, or 2/98 to 50/50, or 3/97 to 40/60.
• the resin composition may include a liquid polymer.
• the liquid polymer means a polymer having fluidity at 23° C.
• the liquid polymer has a glass transition temperature (Tg).
• the liquid polymer may be a conjugated diene-based polymer or a non-conjugated diene-based polymer.
• the liquid polymer is a liquid rubber.
• the liquid rubber means a substance having fluidity at 23° C. and forming a rubber elastomer by crosslinking (more specifically, vulcanization) and/or chain extension. That is, the liquid rubber is an uncured material in one embodiment.
• having fluidity means that, in one embodiment, when a liquid polymer dissolved in cyclohexane is placed in a vial having a body diameter of 21 mm and a total length of 50 mm at 23°C and then dried, the liquid polymer is filled into the vial to a height of 1 mm and sealed, and the vial is left upside down for 24 hours, and a movement of the material in the vertical direction of 0.1 mm or more can be confirmed.
• the liquid polymer may have a monomer composition of a typical polymer, and preferably has a relatively low molecular weight from the viewpoint of ease of handling and good dispersibility of cellulose nanofibers.
• the liquid polymer has a number average molecular weight (Mn) of 80,000 or less, and thus assumes a liquid form.
• Mn number average molecular weight
• the number average molecular weight and weight average molecular weight of the various polymers disclosed herein are values determined in terms of standard polystyrene using gel permeation chromatography, using chloroform as a solvent, and measuring at 40°C, unless otherwise specified.
• the liquid polymer may be combined with cellulose nanofibers to form a masterbatch, and such masterbatch may be combined with a resin to form the resin composition of the present disclosure.
• the number average molecular weight (Mn) of the liquid polymer is preferably 1,000 or more, or 1,500 or more, or 2,000 or more from the viewpoint of thermal stability and the effect of improving the dispersibility of cellulose nanofibers in the resin, and is preferably 80,000 or less, or 50,000 or less, or 40,000 or less, or 30,000 or less, or 10,000 or less in terms of having high fluidity suitable for good dispersion when dispersing cellulose nanofibers in the liquid polymer.
• the weight-average molecular weight (Mw) of the liquid polymer is preferably 1,000 or more, or 2,000 or more, or 4,000 or more from the viewpoint of thermal stability and the effect of improving the dispersibility of cellulose nanofibers in the resin, and is preferably 240,000 or less, or 150,000 or less, or 30,000 or less from the viewpoint of having high fluidity suitable for good dispersion when dispersing cellulose nanofibers in the liquid polymer.
• the glass transition temperature of the liquid polymer is preferably -150°C or higher, or -120°C or higher, or -100°C or higher, in terms of good thermal stability, and is preferably 25°C or lower, or 10°C or lower, or 0°C or lower, in terms of good fluidity.
• the liquid polymer includes a diene polymer, and in another embodiment, a conjugated diene polymer or a non-conjugated diene polymer, or a hydrogenated product thereof.
• the above polymer or hydrogenated product may be an oligomer.
• the monomers constituting the liquid polymer may be unmodified or modified (e.g., acid modified, hydroxyl group modified, etc.).
• the liquid polymer may have reactive groups (e.g., one or more selected from the group consisting of hydroxyl groups, carboxy groups, isocyanato groups, thio groups, amino groups, and halo groups) at both ends, and may therefore be bifunctional. These reactive groups contribute to crosslinking and/or chain extension of the liquid polymer.
• Conjugated diene monomers include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene, and these may be used alone or in combination of two or more.
• the conjugated diene polymer is a copolymer of the above-mentioned conjugated diene monomer and an aromatic vinyl monomer.
• the aromatic vinyl monomer is not particularly limited as long as it is a monomer copolymerizable with the conjugated diene monomer, and examples thereof include styrene, m- or p-methylstyrene, ⁇ -methylstyrene, ethylstyrene, p-tert-butylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, diphenylethylene, and divinylbenzene, which may be used alone or in combination of two or more. From the viewpoints of the molding processability of the resin composition and the impact resistance of the molded article, styrene is preferred.
• the block copolymer may be a copolymer consisting of two or more blocks.
• the block copolymer may be a block copolymer in which a block A of an aromatic vinyl monomer and a block B of a conjugated diene monomer and/or a copolymer of an aromatic vinyl monomer and a conjugated diene monomer constitute a structure such as A-B, A-B-A, or A-B-A-B.
• the boundaries of the blocks do not necessarily need to be clearly distinguished.
• block B is a copolymer of an aromatic vinyl monomer and a conjugated diene monomer
• the aromatic vinyl monomer in block B may be distributed uniformly or in a tapered shape.
• Block B may have a plurality of parts in which the aromatic vinyl monomer is distributed uniformly and/or a plurality of parts in which the aromatic vinyl monomer is distributed in a tapered shape.
• Block B may have a plurality of segments with different aromatic vinyl monomer contents.
• the molecular weights and compositions of the blocks A and B may be the same or different.
• the amount of vinyl bonds (for example, 1,2- or 3,4-bonds of butadiene) in the conjugated diene bond units in the conjugated diene polymer is preferably 10 mol % or more and 75 mol % or less, or 13 mol % or more and 65 mol % or less.
• the amount of vinyl bonds in the conjugated diene bond units (for example, the amount of 1,2-bonds in butadiene) can be determined by 13C -NMR (quantitative mode). That is, by integrating the peak areas shown below in 13C -NMR, a value proportional to the carbon amount of each structural unit can be obtained, which can then be converted into the mass % of each structural unit.
• the hydrogenated conjugated diene polymer may be any of the hydrogenated conjugated diene polymers listed above, for example, a hydrogenated butadiene homopolymer, an isoprene homopolymer, a styrene-butadiene copolymer, or an acrylonitrile-butadiene copolymer.
• the liquid polymer is one or more selected from the group consisting of polybutadiene, butadiene-styrene copolymer, polyisoprene, and polychloroprene. These may be derivatives (e.g., maleic anhydride modified products, methacrylic acid modified products, terminal hydroxyl group modified products, hydrogenated products, and combinations thereof).
• the non-conjugated diene polymer may be a homopolymer, a copolymer of two or more kinds of non-conjugated diene monomers, or a copolymer of a non-conjugated diene monomer and another monomer.
• the copolymer may be either random or block.
• Examples of the non-conjugated diene polymer include olefin polymers (e.g., liquid paraffin), silicone polymers, and acrylic polymers.
• examples of the non-conjugated diene polymer when the liquid polymer is liquid rubber include: Olefin polymers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, and ethylene- ⁇ -olefin copolymers;
• Examples of the rubber include butyl rubber, brominated butyl rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, ⁇ , ⁇ -unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber.
• monomers that can be copolymerized with ethylene units include aliphatic substituted vinyl monomers such as propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, or eicosene-1, isobutylene, and styrene.
• aliphatic substituted vinyl monomers such as propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodec
• vinyl monomers examples include aromatic vinyl monomers such as styrene and substituted styrene, ester vinyl monomers such as vinyl acetate, acrylic esters, methacrylic esters, glycidyl acrylic esters, glycidyl methacrylic esters, and hydroxyethyl methacrylic ester, nitrogen-containing vinyl monomers such as acrylamide, allylamine, vinyl-p-aminobenzene, and acrylonitrile, and dienes such as butadiene, cyclopentadiene, 1,4-hexadiene, and isoprene.
• aromatic vinyl monomers such as styrene and substituted styrene
• ester vinyl monomers such as vinyl acetate, acrylic esters, methacrylic esters, glycidyl acrylic esters, glycidyl methacrylic esters, and hydroxyethyl methacrylic ester
• nitrogen-containing vinyl monomers such as acrylamide,
• the ethylene- ⁇ -olefin copolymer is preferably a copolymer of ethylene and one or more ⁇ -olefins having 3 to 20 carbon atoms, more preferably a copolymer of ethylene and one or more ⁇ -olefins having 3 to 16 carbon atoms, and most preferably a copolymer of ethylene and one or more ⁇ -olefins having 3 to 12 carbon atoms.
• the molecular weight of the ethylene- ⁇ -olefin copolymer is preferably 10,000 or more, more preferably 10,000 to 100,000, more preferably 10,000 to 80,000, and even more preferably 20,000 to 60,000, as the number average molecular weight (Mn) measured with a gel permeation chromatography measuring device using 1,2,4-trichlorobenzene as a solvent at 140°C and polystyrene standards.
• the content of ethylene units in the ethylene- ⁇ -olefin copolymer is preferably 30 to 95% by mass based on the total amount of the ethylene- ⁇ -olefin copolymer.
• Ethylene- ⁇ -olefin copolymers can be produced by conventionally known production methods such as those described in, for example, JP-B-4-12283, JP-A-60-35006, JP-A-60-35007, JP-A-60-35008, JP-A-5-155930, JP-A-3-163088, and the specification of U.S. Pat. No. 5,272,236.
• the liquid polymer includes one or more selected from the group consisting of diene rubber, silicone rubber, urethane rubber, polysulfide rubber, and hydrogenated versions thereof, and preferably includes diene rubber.
• the viscosity of the liquid polymer at 25°C is preferably 1,000,000 mPa ⁇ s or less, or 500,000 mPa ⁇ s or less, or 200,000 mPa ⁇ s or less, from the viewpoint of good dispersion of the cellulose nanofibers in the liquid polymer, and is preferably 100 mPa ⁇ s or more, or 300 mPa ⁇ s or more, or 500 mPa ⁇ s or more, from the viewpoints of thermal stability, the effect of improving the dispersibility of the cellulose nanofibers in the resin, and the mechanical properties of the resin composition.
• the viscosity of the liquid polymer at 50°C is preferably 1,000,000 mPa ⁇ s or less, or 500,000 mPa ⁇ s or less, or 200,000 mPa ⁇ s or less, or 100,000 mPa ⁇ s or less, from the viewpoint of dispersing the cellulose nanofibers well in the liquid polymer and from the viewpoint of dispersing the cellulose nanofibers well in the resin by heating and kneading, and is preferably 50 mPa ⁇ s or more, or 100 mPa ⁇ s or more, or 500 mPa ⁇ s or more, from the viewpoints of thermal stability, the effect of improving the dispersibility of the cellulose nanofibers in the resin, and the mechanical properties of the resin composition.
• the viscosity of the liquid polymer at 80°C is preferably 1,000,000 mPa ⁇ s or less, or 500,000 mPa ⁇ s or less, or 250,000 mPa ⁇ s or less, or 100,000 mPa ⁇ s or less, from the viewpoint of dispersing the cellulose nanofibers well in the liquid polymer and from the viewpoint of dispersing the cellulose nanofibers well in the resin by heating and kneading, and is preferably 50 mPa ⁇ s or more, or 100 mPa ⁇ s or more, or 300 mPa ⁇ s or more, from the viewpoints of thermal stability, the effect of improving the dispersibility of the cellulose nanofibers in the resin, and the mechanical properties of the resin composition.
• the viscosity of the liquid polymer at 0°C is preferably 2,000,000 mPa ⁇ s or less, or 1,000,000 mPa ⁇ s or less, or 400,000 mPa ⁇ s or less, from the viewpoint of good dispersion of the cellulose nanofibers in the liquid polymer, and is preferably 200 mPa ⁇ s or more, or 600 mPa ⁇ s or more, or 1,000 mPa ⁇ s or more, from the viewpoint of thermal stability, the effect of improving the dispersibility of the cellulose nanofibers in the resin, and the mechanical properties of the resin composition.
• the viscosity of the liquid polymer at 80°C, 50°C, 25°C and 0°C is within the above range, since this allows the cellulose nanofibers to be well dispersed in the liquid polymer over a wide range of mixing temperatures.
• the amount of liquid polymer per 100 parts by mass of styrene-based elastomer is preferably 0.1 parts by mass or more, or 0.3 parts by mass or more, or 0.5 parts by mass or more, or 1.0 parts by mass or more, from the viewpoint of obtaining the advantages of the liquid polymer well, and is preferably 15 parts by mass or less, or 10 parts by mass or less, or 5 parts by mass or less, from the viewpoint of obtaining the advantages of the acid-modified styrene-based elastomer well, or from the viewpoint of obtaining a resin composition exhibiting the inherent physical properties of the styrene-based elastomer.
• the amount of liquid polymer per 100 parts by mass of cellulose nanofiber is preferably 5 parts by mass or more, or 10 parts by mass or more, or 20 parts by mass or more, or 30 parts by mass or more, or 40 parts by mass or more, from the viewpoint of obtaining the advantages of the liquid polymer well, and is preferably 400 parts by mass or less, or 200 parts by mass or less, or 100 parts by mass or less, from the viewpoint of obtaining good physical properties of the resin composition and the resin molded article.
• the content of the liquid polymer in the resin composition is preferably 0.1% by mass or more, or 0.3% by mass or more, or 1.0% by mass or more, from the viewpoint of obtaining the advantages of the liquid polymer well, and is preferably 20% by mass or less, or 10% by mass or less, or 7% by mass or less, or 5% by mass or less, from the viewpoint of obtaining good physical properties of the resin composition and the resin molded article.
• the resin composition includes a dispersant.
• the dispersant preferably has a hydrophilic segment and a hydrophobic segment in the same molecule (i.e., is an amphiphilic molecule) from the viewpoint of dispersing the cellulose nanofibers more uniformly in the resin composition.
• the resin composition includes a polyoxyethylene unit-containing polymer.
• the hydrophilic segment is a portion that exhibits good affinity with cellulose nanofibers by containing a hydrophilic structure, specifically including hydroxyl groups, thiol groups, carboxy groups, sulfonic acid groups, sulfate groups, phosphate groups, boronic acid groups, silanol groups, groups derived from sugars such as sorbitan and sucrose, groups derived from glycerin, groups represented by -OM, -COOM, -SO3M , -OSO3M , -HMPO4, and -M2PO4 (wherein M represents an alkali metal or an alkaline earth metal ) , primary to tertiary amines, and quaternary ammonium salts.
• a hydrophilic structure specifically including hydroxyl groups, thiol groups, carboxy groups, sulfonic acid groups, sulfate groups, phosphate groups, boronic acid groups, silanol groups, groups derived from sugars such as sorb
• Examples of the counter anion of the quaternary ammonium salt include halide ions such as hydroxide ion, fluoride ion, chloride ion, bromide ion, and iodide ion, as well as one or more hydrophilic groups selected from the group consisting of nitrate ion, formate ion, acetate ion, trifluoroacetate ion, p-toluenesulfonate ion, hexafluorophosphate, and tetrafluoroborate.
• halide ions such as hydroxide ion, fluoride ion, chloride ion, bromide ion, and iodide ion
• hydrophilic groups selected from the group consisting of nitrate ion, formate ion, acetate ion, trifluoroacetate ion, p-toluenesulfonate ion, he
• hydrophilic segments include polyethylene glycol segments, segments containing repeating units containing a quaternary ammonium salt structure, polyvinyl alcohol segments, polyvinylpyrrolidone segments, polyacrylic acid segments, carboxyvinyl polymer segments, cationized guar gum segments, hydroxyethyl cellulose segments, methyl cellulose segments, carboxymethyl cellulose segments, and polyurethane soft segments (specifically diol segments).
• Nonionic polyoxyethylene derivatives are particularly preferred, and the polyoxyethylene chain length of the polyoxyethylene derivative may be 3 or more, or 5 or more, or 10 or more, or 15 or more.
• the polyoxyethylene chain length may be 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less.
• hydrophobic segments include segments having a hydrocarbon, segments having a fluorocarbon, segments having an alkylene oxide unit having 3 or more carbon atoms (for example, a PPG block), and segments containing a polymer structure.
• Preferred examples of the segment having a hydrocarbon include alkyl, alkenyl, alkyl ether, alkenyl ether, alkyl phenyl ether, alkenyl phenyl ether, rosin ester, bisphenol A, ⁇ -naphthyl, styrenated phenyl, and hydrogenated castor oil.
• the number of carbon atoms in the alkyl or alkenyl chain of the hydrophobic group is preferably 2 or more, or 5 or more, or 10 or more, or 12 or more, or 16 or more.
• the segment having a fluorocarbon a straight-chain or branched alkyl type having 1 to 20 carbon atoms is preferable.
• Preferred examples of the segment containing a polymer structure include acrylic polymers, styrene resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, amino acid lactams including ring-opening polymerization products of lactams, polymers composed of diamines and dicarboxylic acids, polyacetal resins, polycarbonate resins, polyester resins, polyphenylene sulfide resins, polysulfone resins, polyether ketone resins, polyimide resins, fluorine resins, hydrophobic silicone resins, melamine resins, epoxy resins, and phenolic resins.
• These hydrophobic segments may have a linear or branched structure.
• the hydrophobic segment may have a single chain structure or a structure having two or more chains. When the hydrophobic segment has a structure having two or more chains, the hydrophobic segment may have a plurality of types of hydrophobic groups.
• the structure of the amphiphilic molecule is not particularly limited, but when the hydrophilic segment is A and the hydrophobic segment is B, examples of the amphiphilic molecule include linear copolymers such as AB block copolymers, ABA block copolymers, and BAB block copolymers, tri-branched copolymers containing A and B, tetra-branched copolymers containing A and B, star copolymers containing A and B, monocyclic copolymers containing A and B, polycyclic copolymers containing A and B, cage copolymers containing A and B, and graft copolymers containing A and B, where A is a hydrophilic segment and B is a hydrophobic segment.
• linear copolymers such as AB block copolymers, ABA block copolymers, and BAB block copolymers, tri-branched copolymers containing A and B, tetra-branched copolymers containing A and B, star cop
• the molecular structure of the hydrophilic segment may be a single type or a combination of two or more types.
• the molecular structure of the hydrophobic segment may be a single type or a combination of two or more types.
• any of anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants can be used.
• the dispersant may be a polymer surfactant, a reactive surfactant, or the like.
• Nonionic surfactants include, for example, fatty acid dialkanolamides (e.g., lauric acid diethanolamide), polyoxyalkylene fatty acid amides (e.g., polyoxyethylene stearic acid amide), polyoxyalkylene aryl ethers (e.g., polyoxyethylene phenyl ether), polyoxyalkylene alkyl aryl ethers (e.g., polyoxyethylene octylphenyl ether), polyoxyalkylene alkyl or alkenyl ethers (e.g., polyoxyethylene lauryl ether, polyoxyethylene stearyl ether), fatty acid esters of polyhydric alcohols (e.g., polyethylene glycol mono- or distearate esters, polyethylene glycol mono- or dilaurate esters, polyoxyethylene hydrogenated castor oil), glycerin fatty acid esters (e.g., glycerin monostearate, glycerin monoole
• the anionic surfactant may be a carboxylate, sulfonate, sulfate, phosphate, etc.
• the carboxylate include aliphatic monocarboxylic acids and alkyl ether carboxylates
• examples of the sulfonate include dialkyl sulfosuccinates, alkanesulfonates, alkylbenzenesulfonates, and alkylnaphthalenesulfonates
• examples of the sulfate include alkyl sulfates and fat sulfates
• examples of the phosphate include alkyl phosphates and polyoxyethylene alkyl ether phosphates.
• Cationic surfactants include amine salts, amidoamine salts, quaternary ammonium salts, and imidazolinium salts. Specific examples include, but are not limited to, amine salt surfactants such as alkylamine salts, polyoxyethylene alkylamine salts, alkylamidoamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, and imidazolines, as well as quaternary ammonium salt surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, alkylpyridinium salts, alkylisoquinolinium salts, and benzethonium chloride.
• amine salt surfactants such as alkylamine salts, polyoxyethylene alkylamine salts, alkylamidoamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, and imidazolines
• amphoteric surfactants include alkylamine oxides, alanines, imidazolinium betaines, amido betaines, and betaine acetate, and more specifically, long-chain amine oxides, lauryl betaine, stearyl betaine, lauryl carboxymethyl hydroxyethyl imidazolinium betaine, lauryl dimethylamino acetate betaine, and fatty acid amidopropyl dimethylamino acetate betaine.
• the dispersant is preferably a hydrophilic polymer.
• the hydrophilic polymer is a polymer having a hydrophilic group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an ammonium group, a sulfonic acid group, a phosphoric acid group, and the like.
• hydrophilic polymer one or more selected from the group consisting of a cellulose derivative (hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, and the like), a polyalkylene glycol, a polyvinyl alcohol, a polyvinylpyrrolidone, a polyacrylic acid, a carboxyvinyl polymer, a cationized guar gum, a water-soluble polyurethane, a polymer containing a quaternary ammonium salt structure, an amide, an amine, and the like can be used.
• a cellulose derivative and a polyalkylene glycol are more preferable, and a polyalkylene glycol is particularly preferable.
• the amount of dispersant in the resin composition is preferably 1 part by mass or more, or 3 parts by mass or more, or 5 parts by mass or more, or 10 parts by mass or more, or 15 parts by mass or more, and is preferably 200 parts by mass or less, or 150 parts by mass or less, or 100 parts by mass or less, or 90 parts by mass or less, or 80 parts by mass or less, or 70 parts by mass or less, or 60 parts by mass or less, or 50 parts by mass or less, per 100 parts by mass of cellulose nanofiber.
• the content of the dispersant in the resin composition components may be, in one embodiment, 0.1% by mass or more, or 0.5% by mass or more, or 1% by mass or more, and in one embodiment, 40% by mass or less, or 35% by mass or less, or 30% by mass or less.
• the mass ratio of the preliminary composition to the styrene-based elastomer in the resin composition components may be, in one embodiment, 1/99 to 99/1, or 5/95 to 95/5, or 10/90 to 90/10, or 20/80 to 80/20, or 30/70 to 70/30.
• the resin composition component When the resin composition component contains a liquid rubber, the resin composition component typically contains a vulcanizing agent and may optionally contain a vulcanization accelerator.
• the vulcanizing agent and vulcanization accelerator may be appropriately selected from conventionally known ones according to the type of liquid rubber in the resin composition component.
• the vulcanizing agent organic peroxides, azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, sulfur compounds, etc. can be used.
• the sulfur compound sulfur monochloride, sulfur dichloride, disulfide compounds, polymer polysulfur compounds, etc. can be mentioned.
• the amount of vulcanizing agent in the resin composition is preferably 0.01 to 20 parts by mass, or 0.1 to 15 parts by mass, per 100 parts by mass of liquid rubber in the resin composition.
• vulcanization accelerators examples include sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Zinc oxide, stearic acid, and the like may also be used as vulcanization aids.
• the amount of vulcanization accelerator is preferably 0.01 to 20 parts by mass, or 0.1 to 15 parts by mass, per 100 parts by mass of liquid rubber in the resin composition components.
• the resin composition component may contain various conventionally known rubber additives (stabilizers, softeners, antioxidants, etc.).
• As the rubber stabilizer one or more antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol may be used.
• BHT 2,6-di-tert-butyl-4-hydroxytoluene
• n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate and 2-methyl-4,6-bis[(octylthio)methyl]phenol
• As the rubber softener one or more process oils, extender oils, etc. may be used.
• the resin composition of the present embodiment is capable
• vulcanizing agent vulcanization accelerator
• rubber additives are typically added during the production of the resin composition, but the manner of addition is not limited to this.
• the resin composition component may further include additional components.
• additional components include additional polymers, organic or inorganic fillers, heat stabilizers, antioxidants, antistatic agents, colorants, etc.
• the content ratio of any additional component in the resin composition component is appropriately selected within a range in which the desired effects of the present invention are not impaired, and may be, for example, 0.01 to 50% by mass, or 0.1 to 30% by mass.
• the resin composition according to one embodiment can be produced by mixing composition components, which are a mixture containing cellulose nanofibers, an acid-modified styrene-based elastomer, and a styrene-based elastomer.
• the resin composition according to one embodiment can be produced by a method of mixing a composition component, which is a mixture containing a tack inhibitor containing cellulose nanofibers and a styrene-based elastomer. In one embodiment, the mixing is heat kneading.
• a method for producing a resin composition includes a kneading step of heating and kneading a mixture containing a styrene-based elastomer and cellulose nanofibers.
• the weight gain rate of the cellulose nanofiber after heating and kneading relative to the cellulose nanofiber before heating and kneading is preferably 190% or more and 600% or less. From the viewpoint of the interfacial strength between the resin and the cellulose nanofiber, the weight gain rate is preferably 190% or more, or 250% or more, or 300% or more, or 350% or more, and from the viewpoint of suppressing fiber shortening during kneading, it is preferably 600% or less, or 550% or less, or 500% or less.
• the weight gain rate is a value measured by the method described in the [Examples] section of this disclosure.
• a method for producing the resin composition using an acid-modified styrene-based elastomer is as follows: (1) A method comprising: a first step of mixing cellulose nanofibers with an acid-modified styrene-based elastomer to obtain a preliminary composition; and a second step of mixing the preliminary composition with a styrene-based elastomer to obtain a resin composition; (2) A method comprising a step of mixing together resin composition components including cellulose nanofibers, an acid-modified styrene-based elastomer, and a styrene-based elastomer; etc.
• the resin composition components containing the cellulose nanofibers and the styrene-based elastomer may be mixed together in the above method (2).
• the mixing conditions are not particularly limited, and for example, the resin composition may be obtained by mixing the components constituting the resin composition with a stirring means such as a rotation/revolution mixer, a planetary mixer, a propeller type stirrer, a rotary stirrer, an electromagnetic stirrer, an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, etc.
• the components may be stirred under heating in order to efficiently perform shearing.
• the contact opportunity between the cellulose nanofibers and the styrene-based elastomer becomes more moderate and uniform, which can lead to better improvement in the physical properties of the resin composition.
• the cellulose nanofibers to be mixed with the acid-modified styrene-based elastomer or the styrene-based elastomer may be in the form of a dried body containing the cellulose nanofibers.
• the cellulose nanofibers may be mixed with a liquid polymer and/or a dispersant in the form of a slurry, and the liquid medium contained therein may be dried and removed to obtain a dried body containing the cellulose nanofibers.
• the drying process may be carried out, for example, as follows.
• a dry body containing cellulose nanofibers can be produced by drying a cellulose nanofiber slurry.
• the dryer is not particularly limited, but examples thereof include a kneader, a planetary mixer, a Henschel mixer, a high-speed mixer, a propeller mixer, a ribbon mixer, a single-screw or twin-screw extruder, a Banbury mixer, a freeze dryer, a shelf dryer, a spray dryer, a fluidized bed dryer, and a drum dryer.
• the drying temperature may be, for example, 20°C or higher, or 30°C or higher, or 40°C or higher, or 50°C or higher, from the viewpoint of drying efficiency, and of forming a dried body containing cellulose nanofibers with powder properties that are excellent in nano-dispersibility and macro-dispersibility of the cellulose nanofibers in the resin composition; and the drying temperature may be, for example, 200°C or lower, or 180°C or lower, or 160°C or lower, or 140°C or lower, or 120°C or lower, or 100°C or lower, from the viewpoint of making it difficult for thermal deterioration of the cellulose nanofibers and additional components to occur, and from the viewpoint of avoiding excessive pulverization of the dried body containing cellulose nanofibers due to rapid drying of the slurry.
• the drying temperature is the temperature of a heat source in contact with the slurry, and is defined, for example, as the surface temperature of a temperature-control jacket of a drying apparatus, the surface temperature of a heating cylinder, or
• the pressure may be either atmospheric pressure or reduced pressure, but from the viewpoint of forming a dried body containing cellulose nanofibers with powder properties excellent in drying efficiency, nano-dispersibility, and macro-dispersibility of the cellulose nanofibers in the resin composition, the pressure may be -1 kPa or less, or -10 kPa or less, or -20 kPa or less, or -30 kPa or less, or -40 kPa or less, or -50 kPa or less, and from the viewpoint of avoiding excessive pulverization of the dried body containing cellulose nanofibers due to rapid drying of the slurry, the pressure may be -100 kPa or more, or -95 kPa or more, or -90 kPa or more.
• the concentration of cellulose nanofibers in the cellulose nanofiber slurry to be subjected to the drying step is preferably 1% by mass or more, or 2% by mass or more, or 3% by mass or more, or 5% by mass or more, or 10% by mass or more, or 15% by mass or more, or 20% by mass or more, or 25% by mass or more from the viewpoint of process efficiency during drying, and is preferably 50% by mass or less, or 45% by mass or less, or 40% by mass or less, or 35% by mass or less from the viewpoint of maintaining good handleability by avoiding an excessive increase in the viscosity of the slurry and solidification due to aggregation.
• cellulose nanofibers are often produced in a dilute dispersion, and the cellulose nanofiber concentration in the slurry may be adjusted to the above-mentioned preferred range by concentrating such a dilute dispersion. Methods such as suction filtration, pressure filtration, centrifugal deliquation, and heating can be used for concentration.
• the dried material containing cellulose nanofibers may contain a liquid polymer and/or a dispersant, which may be added before, during, and/or after drying of the cellulose nanofiber slurry.
• the liquid polymer and/or dispersant may be added in a dispersed or dissolved state in water and/or an organic solvent.
• the organic solvent is not particularly limited, but is preferably a solvent in which the liquid polymer and dispersant are soluble, and examples of such solvents include non-water-soluble solvents such as chloroform, toluene, hexane, and cyclohexane.
• the liquid medium content of the dried material containing cellulose nanofibers may be preferably 50% by mass or less, or 40% by mass or less, or 30% by mass or less, or 20% by mass or less, or 10% by mass or less, from the viewpoint of workability during kneading with the acid-modified styrene-based elastomer or the styrene-based elastomer.
• a particularly preferred liquid medium content from the viewpoint of the tack suppression effect is 7% by mass or less, or 5% by mass or less, or 3% by mass or less.
• the liquid medium content may be 0% by mass, but from the viewpoint of ease of production of the dried material containing cellulose nanofibers, it may be, for example, 0.1% by mass or more, or 1% by mass or more, or 1.5% by mass or more.
• the liquid medium content is a value measured using an infrared heating type moisture meter.
• the average particle size of the dried material containing cellulose nanofibers is preferably 1 ⁇ m or more, or 10 ⁇ m or more, 50 ⁇ m or more, or 100 ⁇ m or more, or 200 ⁇ m or more, or 500 ⁇ m or more from the viewpoint of ease of production, and is preferably 10,000 ⁇ m or less, or 5,000 ⁇ m or less, or 4,000 ⁇ m or less, or 3,000 ⁇ m or less, or 2,000 ⁇ m or less from the viewpoint that the dried material containing cellulose nanofibers can be easily disintegrated in the resin composition and the cellulose nanofibers can be well dispersed in the resin composition.
• the above average particle size is a value measured with a dynamic image analysis type particle size distribution measuring device (CAMSIZER X2 manufactured by Microtrac).
• the loose bulk density of the dried material containing cellulose nanofibers is preferably 0.01 g/cm 3 or more, or 0.05 g/cm 3 or more, or 0.10 g/cm 3 or more, or 0.15 g/cm 3 or more, or 0.20 g/cm 3 or more, or 0.25 g/cm 3 or more, or 0.30 g/cm 3 or more, or 0.35 g/cm 3 or more, or 0.40 g/cm 3 or more, or 0.45 g/cm 3 or more , or 0.50 g/cm 3 or more, from the viewpoints of good fluidity and excellent feedability of the dried material containing cellulose nanofibers and suppression of migration of a liquid polymer and/or a dispersant to the resin composition; and is preferably 0.85 g/ cm 3 or more from the viewpoints of easy disintegration of the dried material containing cellulose nanofibers in the resin composition and good dispersion of the cellulose
• the solid bulk density of the dry body containing cellulose nanofibers is controlled to a range that is useful for controlling the loose bulk density and compressibility within the range of the present disclosure, and in one aspect, is preferably 0.01 g/cm3 or more , or 0.1 g/cm3 or more , or 0.15 g/cm3 or more , or 0.2 g/cm3 or more , or 0.3 g/cm3 or more , or 0.4 g/cm3 or more , or 0.5 g/ cm3 or more, or 0.6 g/ cm3 or more, and preferably 0.95 g/cm3 or less , or 0.9 g/cm3 or less , or 0.85 g/ cm3 or less.
• the loose bulk density and hardened bulk density are values measured by the method described in the [Examples] section of this disclosure.
• the degree of compression represents the degree of bulk loss.
• the degree of compression of the dried material containing cellulose nanofibers is preferably 1% or more, or 5% or more, or 10% or more, or 15% or more, or 20% or more, or 25% or more, in terms of the fluidity of the dried material containing cellulose nanofibers being not too high.
• the degree of compression is preferably 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less.
• the loose bulk density, hardened bulk density, and compressibility are measured using a powder tester (model number: PT-X) manufactured by Hosokawa Micron Corporation.
• the hardened bulk density is measured by tapping 180 times.
• a tack inhibitor containing cellulose nanofibers in an embodiment in which a tack inhibitor containing cellulose nanofibers is used, the following can also be mentioned.
• a resin composition containing the dried body, an acid-modified styrene-based elastomer, and a styrene-based elastomer is prepared.
• a slurry containing cellulose nanofibers, an acid-modified styrene-based elastomer, a styrene-based elastomer, and optionally a liquid polymer and/or a dispersant is prepared, and then the slurry is dried to prepare a dried body.
• a resin composition containing the dried body and a styrene-based elastomer is prepared.
• the resin composition may be molded into a desired shape, either alone or together with other components, to produce a desired molded product.
• the method of combining the components and the molding method are not particularly limited and may be selected according to the desired molded product. Molding is usually melt molding, and may be performed by injection molding, extrusion molding, extrusion profile molding, blow molding, compression molding, etc.
• the molding method may be a profile molding. That is, in one aspect, the resin molded product of the present embodiment may be a profile molded product.
• One aspect of the present invention also provides a method for producing a profile extrusion molded product, comprising a step of profile extruding the resin composition of the present embodiment.
• a known method can be used for the contour extrusion molding.
• a specific example of the contour extrusion molding method is to feed a resin composition into an extrusion molding machine, knead it while heating it inside, and extrude it from a contour extrusion die to obtain an uncooled resin molded body. Then, the uncooled resin molded body is continuously guided to a cooling zone and cooled to obtain a contour extrusion molded product.
• Another method is to perform melt kneading to obtain a resin composition, extrude using the die of the kneading machine as a die for profile extrusion to obtain an uncooled resin molded product, and then continuously guide the uncooled resin molded product into a cooling zone to cool it and obtain a profile extrusion molded product.
• the lower limit of the extrusion temperature during profile extrusion is preferably +5°C, more preferably +10°C, relative to the melting point when the thermoplastic resin in the resin composition is a crystalline resin, or +10°C, more preferably relative to the glass transition point when the thermoplastic resin in the resin composition is an amorphous resin.
• the upper limit of the extrusion temperature during profile extrusion is preferably +100°C, more preferably +80°C, more preferably +70°C, more preferably +60°C, relative to the melting point when the thermoplastic resin in the resin composition is a crystalline resin, or +100°C, more preferably +80°C, more preferably +70°C, more preferably +60°C, more preferably relative to the glass transition point when the thermoplastic resin in the resin composition is an amorphous resin.
• the upper limit within this range, the deterioration of the cellulose fine fibers can be suppressed, so that the mechanical properties of the resin composition can be maintained, and the drawdown of the resin between the profile extrusion die and the cooling zone can be suppressed, so that the dimensional accuracy of the profile extrusion molded product can be improved.
• the cross-sectional shape of the irregular extrusion molded product are preferably sheet, pipe, tube, and angular.
• the sheet thickness can be 0.2 to 50 mm, and the sheet width can be 10 to 1500 mm.
• the thickness can be 0.1 to 30 mm, and the inner diameter can be 1 to 1000 mm.
• the angle of the corner can be 30 to 150 degrees.
• the minimum radius of curvature on the valley side of the corner can be 0.1 mm.
• a preferred example of the use of the resin composition of this embodiment is a modeling material for 3D printing.
• One aspect of the present invention provides a modeling material for 3D printing that is composed of the resin composition of this embodiment.
• the modeling material for 3D printing may be formed into a desired form selected from various forms such as pellets, filaments, and powder.
• the modeling material for 3D printing has the form of a filament or powder.
• the 3D printing modeling material of this embodiment has the advantage that, due to its ability to inhibit cellulose nanofiber aggregation, it can suppress dripping (drawdown) due to its own weight from the nozzle during molding or when forming into a 3D printing modeling material.
• the filament may be a monofilament or a multifilament, but a monofilament is preferred for ease of molding.
• the diameter of the filamentary modeling material is preferably 0.5 to 5.0 mm, more preferably 1.0 to 3.5 mm, and most preferably 1.5 to 3.0 mm.
• the length of the filamentary modeling material is preferably more than 1 m, more preferably more than 10 m, more preferably more than 100 m, and most preferably more than 300 m. By controlling the shape of the filamentary modeling material within this range, it becomes possible to select a wide range of applicable 3D printers, and it becomes possible to appropriately design the modeling time, size, and sophistication of the model. In one embodiment, the length of the filamentary modeling material may be 20,000 m or less.
• the filament-shaped modeling material can be produced by heating and melting the resin composition, passing it through a small hole in a nozzle or the like, cooling it, and winding it up.
• the diameter of the small hole can be appropriately selected according to the diameter of the filament and the winding speed, but from the viewpoints of production efficiency and the frequency of occurrence of thread breakage defects, it is preferably 0.5 to 10.0 mm, more preferably 0.8 to 5.0 mm, and most preferably 1.0 to 3.0 mm.
• a cooling method a known method such as air cooling or water cooling can be appropriately selected, but air cooling is preferred from the viewpoint of preventing water absorption due to the hydrophilicity of cellulose nanofibers.
• the winding speed of the filament is preferably 0.1 to 10 m/s, more preferably 0.15 to 5 m/s, and most preferably 0.2 to 1 m/s.
• the manufacturing device for the filament-shaped modeling material and the manufacturing device for the resin composition may be the same or different.
• the particle size, particle shape, and aspect ratio of the powdered modeling material can be appropriately selected depending on the 3D printer to be used.
• the particle size is preferably 1 to 10,000 ⁇ m, more preferably 10 to 500 ⁇ m, and most preferably 30 to 200 ⁇ m, from the viewpoints of handling as a modeling material and surface smoothness of the modeled object.
• the particle shape may be spherical or irregular, but irregular shape is preferred from the viewpoint of suppressing voids during modeling.
• the aspect ratio is preferably 1.001 to 3.0, preferably 1.01 to 2.0, and most preferably 1.1 to 1.8, from the viewpoint of suppressing voids by reducing interparticle gaps.
• the powdered modeling material can be produced by pulverizing or reprecipitating the resin composition.
• the method for pulverizing the resin composition is not particularly limited, and may be wet pulverization, dry pulverization, low-temperature pulverization, freeze pulverization, heat pulverization, etc.
• a grinding medium may be used for the purpose of controlling the shape of the powdered modeling material.
• One aspect of the present invention provides a molded object obtained by molding the resin composition (e.g., resin composition pellets) or the molding material for 3D printing of the present embodiment using a 3D printer.
• Another aspect of the present invention provides a method for manufacturing a molded object, comprising a step of molding the resin composition or the molding material for 3D printing of the present embodiment using a 3D printer.
• the molding method of the 3D printer includes a fused deposition modeling method, a photolithography method, a material injection method, a powder bonding method, a powder bed fusion method, and the like. When a filamentary molding material is used, the fused deposition modeling method is preferred, and when a powdery molding material is used, the powder bonding method and the powder bed fusion method are preferred.
• the shaped object may be directly applied to various applications, or may be molded into a desired shape alone or together with other components to produce a desired molded product.
• the method of combining the components and the molding method are not particularly limited and may be selected according to the desired molded product.
• the molding method may include, but is not limited to, cutting molding, foam molding, etc.
• the shaped object or molded product is useful as a substitute for steel plates, fiber-reinforced plastics (e.g., carbon fiber reinforced plastics, glass fiber reinforced plastics, etc.), resin composites containing inorganic fillers, etc.
• Suitable applications of the 3D printing modeling material, shaped object, or molded product include industrial machine parts, general machine parts, automobile, railway, vehicle, ship, aerospace-related parts, electronic and electrical parts, building and civil engineering materials, daily necessities, sports and leisure goods, wind power generation housing parts, containers and packaging parts, etc.
• the resulting molded products can be used for a variety of purposes, including automobile parts, electrical and electronic parts, building materials, lifestyle, cosmetic and medical parts, rails, pipes, sashes, door frames, window frames, handrails, decking materials, fences and various building materials.
• automotive parts include interior parts such as inner handles, fuel trunk openers, seat belt buckles, assist wraps, various switches, knobs, levers, clips, etc.; electrical system parts such as meters and connectors; in-vehicle electrical and electronic parts such as audio equipment and car navigation equipment; parts that come into contact with metal such as window regulator carrier plates; door lock actuator parts, mirror parts, wiper motor system parts, fuel system parts, and other mechanical parts.
• Electrical and electronic parts include parts or components of equipment that are made of resin molded bodies and have many metal contacts, such as audio equipment, video equipment, office automation equipment such as telephones, copy machines, facsimiles, word processors, and computers, and parts or components of toys, specifically chassis, gears, levers, cams, pulleys, bearings, etc.
• the tensile stress (modulus) at 100% elongation (M100) of the resin composition or resin molded body may, in one embodiment, be 2.0 MPa or more, or 3.0 MPa or more, or 4.0 MPa or more, and in one embodiment, may be 10.0 MPa or less, or 9.0 MPa or less, or 8.0 MPa or less.
• the tensile stress at 300% elongation (M300) of the resin composition or resin molded body may, in one embodiment, be 3.0 MPa or more, or 5.0 MPa or more, or 6.0 MPa or more, and in one embodiment, may be 20.0 MPa or less, or 15.0 MPa or less, or 13.0 MPa or less.
• the ratio (M300/M100) of the tensile stress at 300% elongation (M300) to the tensile stress at 100% elongation (M100) of the resin composition or resin molded body may be, in one embodiment, 1.3 or more, or 1.4 or more, or 1.5 or more, and in one embodiment, 2.0 or less, or 1.8 or less.
• the storage modulus of the resin composition or the resin molded body may be, in one embodiment, 2.0 MPa or more, or 2.5 MPa or more, and in one embodiment, 4.0 MPa or less, or 3.5 MPa or less, or 3.0 MPa or less.
• One aspect of the present invention provides a resin molded product obtained by molding the resin composition of the present embodiment.
• the resin molded product may have various shapes.
• the molded product can be used in a wide range of applications, such as industrial machine parts, general machine parts, automobile, railway, vehicle, ship, and aerospace related parts, electronic and electrical parts, construction and civil engineering materials, daily necessities, sports and leisure goods, housing parts for wind power generation, and containers and packaging parts.
• Item 6 Item 6.
• the styrene-based elastomer is an aromatic vinyl compound-conjugated diene compound block copolymer or a hydrogenated product thereof.
• the styrene-based elastomer is an aromatic vinyl compound-conjugated diene compound block copolymer or a hydrogenated product thereof.
• Item 16 Item 16.
• the cellulose nanofibers subjected to the kneading step are in a dry form having a liquid medium content of 7% by mass or less.
• Item 19 Item 17.
• ⁇ Cellulose nanofiber> The cellulose nanofibers were evaluated as follows. [Preparation of porous sheet] First, the concentrated cake was added to tert-butanol, and further dispersed in a mixer or the like until no aggregates were present. The concentration was adjusted to 0.5% by mass relative to 0.5 g of cellulose nanofiber solids. 100 g of the obtained tert-butanol dispersion was filtered on filter paper. The filtered material was not peeled off from the filter paper, but was sandwiched between two sheets of larger filter paper together with the filter paper, and the edges of the larger filter paper were pressed down with a weight and dried for 5 minutes in an oven at 150 ° C.
• N,N-dimethylacetamide and solids were separated again by centrifugation, and then 20 mL of N,N-dimethylacetamide was added, lightly stirred, and left for one day.
• N,N-dimethylacetamide and solids were separated by centrifugation, and 19.2 g of N,N-dimethylacetamide solution prepared so that lithium chloride was 8 mass percent was added to the solids, and the mixture was stirred with a stirrer, and it was confirmed that it was dissolved by visual observation.
• the solution in which the cellulose nanofibers were dissolved was filtered through a 0.45 ⁇ m filter, and the filtrate was used as a sample for gel permeation chromatography.
• the apparatus and measurement conditions used are as follows.
• the measurement was performed by adjusting the magnification so that at least 100 cellulose nanofibers were observed, and the diameters (D) of 100 randomly selected cellulose nanofibers were measured, and the arithmetic average of the 100 cellulose nanofibers was calculated as the number average fiber diameter.
• Thermal decomposition start temperature ( TD ) The thermal analysis of the porous sheet was carried out by the following measurement method. Apparatus: Thermo plus EVO2, manufactured by Rigaku Corporation Sample: A circular sample was cut out from the porous sheet and placed in an aluminum sample pan in a pile of 10 mg. Sample amount: 10 mg Measurement conditions: In a nitrogen flow of 100 ml/min, the temperature was increased from room temperature to 150° C. at a rate of 10° C./min, and after holding at 150° C. for 1 hour, the temperature was increased to 450° C. at a rate of 10° C./min. TD calculation method: Calculated from a graph with temperature on the horizontal axis and weight remaining rate % on the vertical axis.
• the temperature was further increased to obtain a straight line passing through the temperature at 1 wt% weight loss and the temperature at 2 wt% weight loss.
• the temperature at the point where this straight line intersects with the horizontal line (baseline) passing through the starting point of 0 wt% weight loss was determined as the thermal decomposition onset temperature ( TD ).
• ⁇ Resin composition> [Whitening degree at break (void amount)]
• the test pieces were used after the tensile test according to JIS K-6251, and the fracture site (2 mm in ND direction ⁇ 3 mm in TD direction ⁇ 4 mm in MD direction) was observed in the MD/TD cross section using X-ray CT.
• the properties of the cellulose nanofiber are as follows: Weight average molecular weight (Mw): 380000 Number average molecular weight (Mn): 80000 Average content of alkali-soluble polysaccharides: 3.8% Average content of acid-insoluble components: 3.1% Crystallinity: 85% Number average fiber diameter: 75 nm Specific surface area: 34m 2 /g Thermal decomposition start temperature (T D ): 283°C 1wt% weight loss temperature: 297°C 250°C weight loss rate: 2.8%
• Example 1 Cellulose nanofiber cake, RICON 184 and PEG 6000 were mixed in a ratio of 7:4:3 by solid weight, and the mixture was mixed in a planetary mixer (model number: ACM-5LVT: paddle type) manufactured by Kodaira Seisakusho Co., Ltd. under the conditions of a jacket temperature of 80°C and stirring at 307 rpm, while reducing the pressure to -90 kPa with a vacuum pump. The mixture was dried under reduced pressure until the product temperature reached 70°C, and a cellulose nanofiber powder was obtained.
• a planetary mixer model number: ACM-5LVT: paddle type

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