Resin composite and method for producing resin composite

Abstract

The resin composite contains a thermoplastic resin and cellulose fibers, and the raw material of the main component of the cellulose fibers is a low basis weight paper having a basis weight of 100 g / m2 or less after a drying step.

Description

TECHNICAL FIELD

[0001] The present application relates to a resin composite and a method for producing a resin composite. BACKGROUND

[0002] In a resin composite, mechanical strength (flexural modulus, flexural strength) and impact strength are in a trade-off relationship, and various studies have been made to eliminate the trade-off (for example, refer to Patent Documents 1 to 3). In Patent Documents 1 and 2, a resin composite containing an inorganic filler was studied, and in Patent Document 3, a resin composite containing a reinforcing fiber was studied, but further improvement in performance is required. In addition, the linear expansion coefficient is an important index for imparting dimensional stability in molding of a thermoplastic resin, but a resin composite and a method for producing the same, which are excellent in all of mechanical strength, impact strength, and linear expansion coefficient, have not yet been established.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-62492

[0006] Patent Document 2: International Publication No. 2018 / 135648

[0007] Patent Document 3: International Publication No. 2019 / 208826 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] An object of the present application is to provide a resin composite and a method for producing a resin composite, which are excellent in mechanical strength, impact strength, and linear expansion coefficient.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The present inventors made intensive studies, and as a result, found that the above object can be achieved by using a low-basis weight paper subjected to a drying process, particularly a household tissue paper product such as toilet paper, paper towel, and wiping paper, and thus completed the present application. Specifically, a resin composite obtained by heat-kneading cellulose fibers obtained from a low-basis weight paper subjected to a drying process and a thermoplastic resin is excellent in mechanical strength (flexural modulus, flexural strength), impact strength, and linear expansion coefficient.

[0012] That is, according to the present application, there are provided

[0013] (1) A resin composite comprising a thermoplastic resin and cellulose fibers, wherein a raw material of a main component of the cellulose fibers is a low-basis weight paper subjected to a drying process, and a basis weight of the low-basis weight paper is 100 g / m 2The following low-basis weight paper.

[0014] (2) The resin composite according to (1), characterized in that the cellulose fibers are a pulverized product of a pulverization treatment process.

[0015] (3) The resin composite according to (1) or (2), characterized in that the cellulose fibers are a pulverized product having a loose bulk density in the range of 10 to 60 g / L.

[0016] (4) The resin composite according to (1) or (2), characterized in that the cellulose fibers are a pulverized product having a compact bulk density in the range of 15 to 80 g / L.

[0017] (5) The resin composite according to (1) or (2), characterized in that the cellulose fibers have an aspect ratio represented by

[0018] an aspect ratio retention of 60% or more.

[0019]

[0020] (6) The resin composite according to (1) or (2), wherein the low-basis weight paper is a tissue paper having a basis weight of 3 to 40 g / m 2 .

[0021] (7) The resin composite according to (1) or (2), wherein the low-basis weight paper is a household tissue paper.

[0022] (8) The resin composite according to (1) or (2), characterized in that the thermoplastic resin is a polyolefin or a blend of a polyolefin and an elastomer, has a flexural elastic modulus of 1.00 GPa or more, an impact strength of 5.0 kJ / m 2 or more, and a linear expansion coefficient of 100 x 10 -6 / K or less. (9) The resin composite according to (1) or (2), wherein the thermoplastic resin is a nylon or a blend of a nylon and an elastomer having an impact strength of 3.0 kJ / m 2 or more, (10) The resin composite according to (1) or (2), characterized in that the thermoplastic resin is a nylon or a blend of a nylon and an elastomer, has a flexural elastic modulus of 1.60 GPa or more, an impact strength of 2.0 kJ / m 2 or more, and a linear expansion coefficient of 70 x 10 -6 / K or less.

[0023] ​(11) The resin composite according to (1) or (2), wherein the thermoplastic resin is a resin having a flexural strength of 3.0 kJ / m 2 The polylactic acid above or a blend of polylactic acid and an elastomer.

[0024] (12) The resin composite according to (1) or (2), characterized in that the thermoplastic resin is polylactic acid or a blend of polylactic acid and an elastomer, the flexural modulus is 3.50 GPa or more, the impact strength is 3.0 kJ / m 2 or more above, and the linear expansion coefficient is 80 x 10 -6 or less.

[0025] (13) A method for manufacturing a resin composite, characterized by having the following processes (A) to (C), Process (A): supplying a raw material pulp to a papermaking process and a drying process to obtain a low-basis-weight paper having a basis weight of 100 g / m 2 or less, Process (B): a process of performing a pulverization treatment on the low-basis-weight paper that has passed through the process (A), Process (C): a process of mixing the low-basis-weight paper that has been subjected to the pulverization treatment in the process (B) with a thermoplastic resin and performing heat kneading.

[0026] (14) The method for manufacturing a resin composite according to (13), characterized in that the process (B) performs the pulverization treatment in such a manner that the loose bulk density of the low-basis-weight paper becomes in the range of 10 to 60 g / L.

[0027] (15) The method for manufacturing a resin composite according to (13) or (14), characterized in that the process (B) performs the pulverization treatment in such a manner that the compact bulk density of the low-basis-weight paper becomes in the range of 15 to 80 g / L.

[0028] (16) The method for manufacturing a resin composite according to (13) or (14), characterized in that the process (B) performs the pulverization treatment in such a manner that the aspect ratio retention rate represented by

[0029] the aspect ratio of the low-basis-weight paper before the pulverization treatment process) x 100 (%)

[0030] becomes 60% or more.

[0031] Effects of the Invention

[0032] According to the present application, it is possible to provide a resin composite and a method for manufacturing a resin composite, which are excellent in mechanical strength (flexural modulus, flexural strength), impact strength, and linear expansion coefficient. DETAILED DESCRIPTION

[0033] Hereinafter, the resin composite of the present application and the method for producing the resin composite will be described. The resin composite of the present application is a resin composite comprising a thermoplastic resin and a cellulose fiber, the main component of which is obtained from a low basis weight paper that has undergone a drying process, and the basis weight of which is 100 g / m2or less. 2 The low basis weight paper described below is used as a raw material.

[0034] Further, the method for producing the resin composite of the present application is characterized by having the following processes (A) to (C).

[0035] Process (A): supplying a raw material paper pulp to a papermaking process and a drying process to obtain a low basis weight paper having a basis weight of 100 g / m2or less, 2 The process of the low basis weight paper described below, Process (B): a process of performing a pulverization treatment on the low basis weight paper that has undergone the process (A), Process (C): a process of mixing the low basis weight paper that has undergone the pulverization treatment by the process (B) with a thermoplastic resin and performing a heat kneading.

[0036] (Cellulose fiber)

[0037] The main component of the cellulose fiber used in the present application can be obtained from a low basis weight paper that has undergone a drying process.

[0038] In the present application, the low basis weight paper that has undergone a drying process can be subsequently subjected to a wet breaking.

[0039] In the present application, a low basis weight paper that has undergone a drying process is used, but a low basis weight paper having a basis weight of 100 g / m2or less is used. 2 The low basis weight paper described below. Generally, in the production of paper, papermaking processes such as papermaking and coating are performed at high speed and with high efficiency, and the paper is manufactured by a strong drying process in multiple stages, and a paper that has undergone such a process tends to obtain straight fibers in which the number of hydrogen bonding points between cellulose fibers is relatively large. On the other hand, in the production of a low basis weight paper, the production is mostly performed at a relatively low speed in order to prevent paper breakage, and cellulose fibers that are easy to disperse and have a small number of hydrogen bonding points can be obtained. It is considered that by containing such fibers, the fibers in the resin composite become easy to disperse in a state of being elongated and having a high aspect ratio, and the mechanical strength increases. In the present application, it has been found that by using such a low basis weight paper to produce a resin composite, the problem is solved on one end.

[0040] As a manufacturing method of these low-basis weight papers, there is no particular limitation, and a papermaking raw material centered on plant fibers at a prescribed concentration can be passed through a Fourdrinier, a cylinder mold, or a cylinder, to perform papermaking on a web (wet paper), dewatering is performed by pressing, and further drying is performed using various publicly known drying devices, to thereby obtain. In addition, it can also be manufactured by further winding into a roll afterward. As examples of such papers, there can be mentioned printing paper such as thin paper, newspaper paper, high-quality paper, medium-quality paper, high-quality paper, and the like, packaging paper, moisture-proof paper, lining paper for wall paper, raw paper for paperware, raw paper for laminated board, raw paper for molding applications, and the like, inkjet recording paper, thermal recording paper, pressure-sensitive recording paper, fine-coated paper such as art paper, foam paper, corrugated paper raw paper, and the like, and in order to suppress agglomerates in the resin composite, it is preferable that the paper not be accompanied by a coating layer, a laminate. These papers are preferably 100 g / m 2 Hereinafter, a commercially available paper can be used without particular limitation.

[0041] Further, it is known that by using thin paper, which is particularly low in basis weight among the above low-basis weight papers, the effect increases. According to Paper Pulp Guide (issued in 1971), thin paper is a general term for thin paper, and is 40 g / m 2 or less in basis weight. Hereinafter. Thin paper is lower in basis weight among the above papers, and when foreign matter, inclusions are contained in the pulp, paper breakage and the like occurs, and has the property of being difficult to papermaking. In addition, it is known that when agglomerates originating from the pulp are contained in the resin composite, they become a starting point of cracks generated in a strength test, and the impact strength decreases. Thin paper is a low-basis weight paper, and thus is a paper that is preferably manufactured in a manner in which foreign matter, inclusions, and agglomerates are less mixed in thin paper manufacturing, and is more suitable for the present application, but is poor in handling properties on papermaking when the basis weight is too low, and thus is preferably 3 to 40 g / m 2 , and further preferably 5 to 30 g / m 2 .

[0042] As a specific thin paper, there can be used household thin paper, glassine paper, rice paper, Indian paper, carbon paper raw paper, office thin paper, condenser paper, carbonless raw paper, back carbon raw paper, pressure-sensitive paper, foil paper, lining paper, insulating paper, release paper, cap raw paper, paper cloth raw paper, paper weaving raw paper, face tape paper, paper for artificial silk refining, fruit packaging paper, transfer paper, graph paper raw paper, airmail paper, flower-making raw paper, water guide raw paper, knot raw paper, legal instrument paper, parchment paper, Beijing paper, tea bag paper, and the like.

[0043] Among them, the household thin paper is less mixed with agents, fillers, and inclusions in the paper pulp and papermaking process, and is more preferable. As the household thin paper, there are paper towels, toilet paper, wiping paper, hand paper, towel paper, sanitary napkin paper, table napkin paper, tempura pad paper, bed sheet paper, pillow cover paper, diaper paper, paper diaper paper, formal paper, and the like. In particular, toilet paper, paper towels, and wiping paper are less mixed with agents and fillers, and the mixing of foreign matter and inclusions is strictly managed in terms of hygiene, and thus are preferable, and toilet paper is particularly preferable.

[0044] The toilet paper preferably complies with the standards of JIS P4501:2006, and particularly preferably has a basis weight of 18 g / m 2 In the above, the burst strength is 78 kPa or more, and particularly the easy-to-disintegrate property is 100 s or less.

[0045] As the papermaking raw material of the paper used in the present application, for example, wood-based virgin pulp such as coniferous bleached kraft pulp (NBKP), broad-leaved bleached kraft pulp (LBKP), or coniferous unbleached kraft pulp (NUKP), or waste paper pulp regenerated from waste paper can be preferably used. In addition to the above, wood pulp from coniferous trees and broad-leaved trees can be used, and as pulp from non-wood plants, rice straw pulp, sugar cane bagasse pulp, reed pulp, kenaf pulp, linen pulp, ramie pulp, hemp pulp, flax pulp, bamboo pulp, and the like can be mentioned. In the present application, the pulp can or can not contain lignin, and a treatment for removing lignin during the manufacturing process or a treatment for removing lignin from lignocellulosic fibers can be performed. In addition, fibers derived from plants that do not originally contain lignin can also be used. Furthermore, for example, dissolving pulp, sulfite pulp, kraft pulp, semi-chemical pulp, chemical pulp, refiner pulp, thermomechanical pulp, groundwood pulp, refiner pulp, thermomechanical pulp, and fiberboard pulp can be used. Using these pulps, a low-basis-weight paper can be obtained by performing a papermaking process and a drying process, but the above-mentioned pulps can be used alone or in combination.

[0046] These pulps can be adjusted and changed in terms of the quality required for various papers and the blending ratio. In addition, various chemicals can be added (internal addition) in order to stabilize the required quality and operation. As such chemicals, softening agents, bulking agents, dyes, dispersants, wet paper strength enhancers, dry paper strength agents, drainage improvers, resin control agents, yield improvers, and the like can be mentioned. In addition, these pulps can be bleached, and intermediate products during the manufacturing process, specifically waste paper, process recycled paper, which have undergone a drying process, can be used.

[0047] Embodiments of the present application relate to low-basis weight paper that can be manufactured by a publicly known papermaking method. One example is described below, but is not limited thereto. First, a papermaking raw material is supplied from a raw material tank, and further diluted with white water to prepare a paper stock. After the paper stock is degassed and screened to remove dust, it is delivered to a stock inlet using a blower pump. The stock inlet supplies the paper stock, which is well dispersed with fibers, to a full-width wire of a papermaking machine at an appropriate concentration, speed, and angle in a uniform manner without flocculation (clumps) and without generating flow lines. As the stock inlet, any of a headbox provided at a high position in an open manner to the atmosphere, a pressurized type, a hydraulic type, and the like can be used. Then, the paper stock is ejected from the stock inlet to between the wire and a felt, and a sheet (paper web, wet paper) is formed on the felt.

[0048] The paper web formed between the wire and the felt is transferred to a Yankee dryer using a press roll. Subsequently, the paper web is dried by the Yankee dryer and the Yankee dryer hood, and further peeled from the Yankee dryer while being subjected to a creping process by a creping blade, and wound into a roll by a reel. The Yankee dryer is a cast iron or cast steel roll for drying the paper web, and generally has an outer diameter of 2.4 to 6 m.

[0049] Here, the creping is a method of mechanically compressing the paper in the longitudinal direction (machine running direction) to form wavy wrinkles called crepe, and is used to impart bulk (fluffiness), softness, water absorbency, smoothness of the surface, beauty (shape of the crepe), and the like in low-basis weight paper, particularly in thin paper such as toilet paper, paper towel, and the like. Further, the crepe is formed by the creping blade using the speed difference between the Yankee dryer and the roll (speed of the roll < speed of the Yankee dryer). The characteristics of the crepe also depend on the above-mentioned speed difference, but if the basis weight of the raw paper on the Yankee dryer is 7 to 40 g / m 2 , the basis weight on the roll is substantially 9 to 50 g / m 2 , which is greater than the basis weight on the Yankee dryer.

[0050] The creping rate based on the speed difference between the Yankee dryer and the roll is defined by the following equation.

[0051] Creping rate (%) = 100 x (speed of the Yankee dryer (m / min) - speed of the roll (m / min)) ÷ speed of the roll (m / min)

[0052] The quality of the crepe and the operability of the creping are substantially determined by the creping rate, and in the present application, the creping rate is preferably in the range of 10% to 50%.

[0053] In the present application, low-basis-weight paper subjected to a drying process is used as a cellulose raw material, but the pretreatment method for supplying to a kneader is not particularly limited. In addition, the pretreatment can be dry crushing or wet crushing, and is preferably performed in a wet state. By performing the crushing in a wet state, i.e., in a state of a sheet containing water, the paper to be used can be crushed to a uniform size, and the subsequent processes of mixing with a thermoplastic resin, and supplying the low-basis-weight paper to a kneader can be easily performed. Furthermore, the dispersion in the thermoplastic resin performed in the kneader, and the opening of the cellulose fibers to the nanoscale can be easily and uniformly performed. Performing the dispersion and the opening to a uniform level is effective for further improving the mechanical strength, the impact strength, and the reduction in the linear expansion coefficient. As the crushing method, a publicly known method can be used, and a jet mill, a roll mill, a ball mill, a chopper mill, a stone mortar-type mill, an impact mill, a Dyno-mill, an ultrasonic mill, a vibration mill, a Lodige mixer, a Henschel-type mixer, a household juicer mixer, a mortar, or the like can be used.

[0054] In addition, a modification treatment for imparting hydrophobicity to the cellulose fibers used in the present application can also be performed. The imparting of hydrophobicity is known by the following methods: (1) a method of directly hydrophobizing the cellulose fibers by introducing various hydrocarbon groups or the like by etherification, esterification, dithioesterification, or the like of the hydroxyl groups of cellulose; (2) a method of indirectly hydrophobizing by introducing various hydrocarbon groups or the like by a direct ionic bond, an ionic bond via a metal ion or the like, an amide bond, or an ester bond or the like to ionic functional groups such as carboxyl groups, phosphoric acid groups, phosphorous acid groups, amino groups, or the like introduced to the hydroxyl groups of cellulose by oxidation, etherification, esterification, carbamoylation, or the like. By these hydrophobization, the dispersibility in the resin composite is improved, and various physical properties such as the mechanical strength are improved, on the other hand, there are concerns about the reduction in the crystallinity, the increase in the number of processes, the generation of VOC at the time of the residual of the compounds used in the modification treatment, or the like.

[0055] In the present application, the effects are exhibited even without using these modified cellulose fibers, but in order to adjust the physical properties, the cellulose fibers from the low-basis-weight paper subjected to a drying process can also be subjected to a modification treatment and used.

[0056] In addition, in the present application, a high-basis-weight paper other than the low-basis-weight paper subjected to a drying process, a pulp dried without a papermaking process can be used as the cellulose fibers within a range not impairing the effects of the present application, but in order to suppress the agglomerates in the resin composite, a paper sheet not accompanied by a coating layer, lamination, or the like is preferred. In addition, as to the proportion of the mixture, 49% by mass or less of the entire cellulose fibers can be mixed, and 33% by mass or less is preferred.

[0057] In the present application, the low-basis-weight paper subjected to the drying step can be subjected to a pulverization treatment. Alternatively, the low-basis-weight paper subjected to the drying step can be subjected to a pulverization treatment after being subjected to a water-containing crushing. By subjecting to the pulverization treatment, the conveyance workability at the time of producing the resin composite is improved, the aggregation of the cellulose fiber and the like in the resin composite is suppressed, and a resin composite having good physical properties can be obtained.

[0058] Note that, in the present application, pulverization refers to a process of applying a strong shearing force to finely pulverize to the extent of primary particles, and is clearly distinguished from the crushing described later (coarse pulverization to the extent of secondary aggregation for the purpose of loosening the low-basis-weight paper).

[0059] The method of the pulverization treatment is not particularly limited, and, for example, a pulverization device can be used for the pulverization treatment. As the pulverization device, a dry-type pulverizer and a wet-type pulverizer can be exemplified.

[0060] The dry-type pulverizer can exemplify a shredding mill, an impact mill, an air-flow mill, and a media mill. They can be used alone, or a plurality of them can be used in combination, and further, a plurality of the same type can be used for a segmented treatment.

[0061] As the shredding mill, a mesh mill (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hombu Mfg. Co., Ltd.), a knife mill (manufactured by Pallmann Co.), a granulator (manufactured by Herbold Co.), a rotary shredding mill (manufactured by Nara Machine Mfg. Co., Ltd.), and the like can be exemplified.

[0062] As the impact mill, a Pulperizer (manufactured by Hosokawa Micron Co., Ltd.), a fine impact mill (manufactured by Hosokawa Micron Co., Ltd.), a Super Micron Mill (manufactured by Hosokawa Micron Co., Ltd.), a Sample Mill (manufactured by Seishin Co., Ltd.), a Bantam Mill (manufactured by Seishin Co., Ltd.), an Atomizer (manufactured by Seishin Co., Ltd.), a cyclone mill (manufactured by Nikkiso Co.), a turbo mill (manufactured by Turbo Industry Co., Ltd.), a Bevel impact mill (manufactured by Aikawa Iron Works Co., Ltd.), and the like can be exemplified.

[0063] As the air-flow mill, a CGS-type jet mill (manufactured by Mitsui Mining Co., Ltd.), a jet mill (manufactured by Zozensha Co., Ltd.), an Ebara Jet Micronizer (manufactured by Ebara Mfg. Co., Ltd.), a Ceren Miller (manufactured by Masuyuki Sangyo Co., Ltd.), a supersonic jet mill (manufactured by Japan Pneumatic Co., Ltd.), and the like can be exemplified.

[0064] As the media mill, a vibration ball mill and the like can be exemplified.

[0065] As the wet-type pulverizer, Masscolloider (manufactured by Kakushiki Co., Ltd.), high-pressure homogenizer (manufactured by San-Ai Machinery Co., Ltd.), and media mill can be exemplified. As the media mill, a bead mill (manufactured by AIMEX Co., Ltd.) or the like can be exemplified.

[0066] The bulk density of the pulverized product obtained in the pulverization treatment step is preferably in the range of 10 to 60 g / L, more preferably in the range of 10 to 40 g / L, and further preferably in the range of 10 to 30 g / L.

[0067] Here, the bulk density can be measured, for example, by the following method.

[0068] In order to eliminate the aggregation of the fibers, about 50 g of the pulverized product is put into a prepared bag, air is blown and dispersed (for 30 seconds), and the pulverized product is put into a 1000-cc graduated cylinder until 700 cc. The weight is measured. The above operation is performed three times, and the average of the measured weights is taken as the bulk density.

[0069] By making the bulk density in the above range, the caking in the conveyance at the time of manufacturing the resin composite can be suppressed, and the cellulose fibers can be easily and uniformly filled without segregation at the time of manufacturing the resin composite.

[0070] In addition, the compacted bulk density of the pulverized product after the pulverization treatment step is preferably in the range of 15 to 80 g / L, more preferably in the range of 15 to 60 g / L, and further preferably in the range of 15 to 50 g / L.

[0071] Here, the compacted bulk density can be measured, for example, by the following method.

[0072] In order to eliminate the aggregation of the fibers, about 50 g of the pulverized product is put into a prepared bag, air is blown and dispersed (for 30 seconds), and the pulverized product is put into a 1000-cc graduated cylinder until 1200 cc (2 times the measurement amount from the limit position without a scale). Then, the graduated cylinder is fixed in the air, and the bottom is tapped with a palm at a frequency of 250 times / minute for 150 times. Then, the pulverized product is removed to the 600-cc scale of the graduated cylinder, and the weight is measured. The above operation is performed three times, and the average of the measured weights is taken as the compacted bulk density.

[0073] By making the compacted bulk density in the above range, the caking in the conveyance at the time of manufacturing the resin composite can be suppressed even when the pulverized product is conveyed by applying pressure, and the cellulose fibers can be easily and uniformly filled without segregation at the time of manufacturing the resin composite.

[0074] In addition, with respect to the pulverized product after the pulverization treatment step,

[0075] (Aspect ratio of cellulose fibers in the pulverized material) / (Aspect ratio of cellulose fibers before pulverization) × 100

[0076] The aspect ratio retention rate is preferably 60% or more, and as an upper limit, it can be 100% or less, preferably 99% or less, more preferably 95% or less, and even more preferably 93% or less.

[0077] Here, the aspect ratio can be derived from...

[0078] (Length of cellulose fibers in the pulverized material) / (Diameter of cellulose fibers in the pulverized material)

[0079] The fiber length and fiber diameter can be determined, for example, by measuring them using a fiber tester.

[0080] In this invention, which includes a pulverizing process, by adjusting the aspect ratio retention rate to the range described above, the reduction in mechanical strength, impact strength, coefficient of linear expansion, etc., caused by the shortening of cellulose fibers can be suppressed, and the objective of this invention can be easily achieved.

[0081] (Thermoplastic resin)

[0082] The thermoplastic resin used in this invention preferably has an impact strength of at least a specified value (e.g., 10 kJ / m² in the case of polyolefins) in the form of a single resin or a resin mixture that does not contain cellulose fibers. 2 The above figure is 3.0 kJ / m in the case of polyamide or aliphatic polyester. 2 The above-mentioned resins are not particularly limited, and polyamides, polyolefins, aliphatic polyesters, aromatic polyesters, polyacetals, polycarbonates, polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS resins), polycarbonate-ABS alloys (PC-ABS alloys), and modified polyphenylene ethers (m-PPEs) are preferred.

[0083] In addition, these thermoplastic resins can also be subjected to chemical treatments such as acid modification and chlorination.

[0084] As polyamides (PA), polyamide 6 (nylon 6, PA6), polyamide 66 (nylon 66, PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), polyamide 12 (PA12), polyamide 46, polyamide XD10 (PAXD10), polyamide MXD6 (PAMXD6), etc. are preferred.

[0085] As the polyolefin, polypropylene (PP), polyethylene (PE, (HDPE, MDPE, LDPE)), a copolymer of ethylene and propylene, or the like can be preferably used. In addition, polyisobutylene, polyisoprene, polybutadiene, or the like can also be preferably used.

[0086] As the polypropylene (PP), isotactic polypropylene (iPP), syndiotactic polypropylene (sPP), or the like can be preferably used.

[0087] As the aliphatic polyester, a polymer or copolymer of a diol and an aliphatic dicarboxylic acid such as succinic acid or glutaric acid (e.g., polybutylene succinate (PBS)), or a polyhydroxyalkanoate derived from microbial production or the like (e.g., a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBH)), a homopolymer or copolymer of a hydroxycarboxylic acid such as glycolic acid or lactic acid (e.g., polylactic acid (PLA), poly-epsilon-caprolactone (PCL), or the like), and a copolymer of a diol, an aliphatic dicarboxylic acid, and the hydroxycarboxylic acid, or the like can be preferably used.

[0088] As the aromatic polyester, a polymer of a diol such as ethylene glycol, propylene glycol, or 1,4-butanediol and an aromatic dicarboxylic acid such as terephthalic acid, or the like can be preferably used. Specifically, for example, polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), or the like can be preferably used.

[0089] As the polyacetal (also referred to as polyoxymethylene, POM), a copolymer of paraformaldehyde and ethylene oxide can be preferably used in addition to a homopolymer of paraformaldehyde.

[0090] As the polycarbonate (PC), a reaction product of a bisphenol such as bisphenol A or a derivative thereof and phosgene or phenyl dichloroformate can be preferably used.

[0091] As the polystyrene (PS), in addition to general-purpose PS (GPPS), a PS (HIPS) in which a rubber component is dispersed in a PS matrix to improve impact resistance, a copolymer of styrene (acrylonitrile-butadiene-styrene copolymer, ABS resin) can be preferably used.

[0092] A PC-ABS alloy can be preferably used in terms of excellent impact resistance, weather resistance, and moldability. In addition, as the m-PPE, a blend of PPE and PS (PPE-PS blend) can be preferably used because of high heat resistance and light weight.

[0093] In addition, as the thermoplastic resin other than the above, for example, polyvinyl chloride, polyvinylidene chloride, fluororesin, (meth)acrylic resin, (thermoplastic) polyurethane, vinyl ether resin, polysulfone-based resin, cellulose-based resin (for example, triacetyl cellulose, diacetyl cellulose, acetyl butyl cellulose, and the like), copolymer of polystyrene and acrylonitrile (AS resin), PHA, PBSA, PBAT, and the like, which are biodegradable resins other than the above, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyamide-imide, polyether-imide, polyether-ketone, polyimide, liquid crystal polymer, fluororesin, and the like can be used.

[0094] These thermoplastic resins preferably have an impact strength of a prescribed value or more when the thermoplastic resin is a single kind or a mixture of two or more kinds, and can be a copolymer of each thermoplastic resin. In this case, the copolymer of the copolymer is not particularly limited, and from the viewpoint of easily exhibiting impact strength, it is preferable to use polyolefin such as polyethylene, polypropylene, and polybutylene, polyamide 6 (nylon 6, PA6), polylactic acid (PLA), and the like. In this case, in the case where polyolefin is used as the thermoplastic resin, the above impact strength is preferably 10 kJ / m 2 In the case where polyamide 6 (nylon 6, PA6) or polylactic acid (PLA) is used as the thermoplastic resin, the above impact strength is preferably 3.0 kJ / m 2 In the case where polyamide 6 (nylon 6, PA6) or polylactic acid (PLA) is used as the thermoplastic resin, the above impact strength is preferably 3.0 kJ / m 2 In the case where polyamide 6 (nylon 6, PA6) or polylactic acid (PLA) is used as the thermoplastic resin, the above impact strength is preferably 3.0 kJ / m 2 In the case where polyamide 6 (nylon 6, PA6) or polylactic acid (PLA) is used as the thermoplastic resin, the above impact strength is preferably 3.0 kJ / m

[0095] In the present application, as the elastomer, the following materials can be used. For example, natural rubber, chloroprene rubber, ethylene-propylene-non-conjugated diene copolymer rubber, ethylene-butene-1 copolymer rubber, ethylene-hexene copolymer rubber, ethylene-octene copolymer rubber, polybutadiene, styrene-butadiene block copolymer rubber, styrene-butadiene copolymer rubber, partially hydrogenated styrene-butadiene-styrene block copolymer rubber, styrene-isoprene block copolymer rubber, partially hydrogenated styrene-isoprene block copolymer rubber, polyurethane rubber, styrene-graft-ethylene-propylene-non-conjugated diene copolymer rubber, styrene-graft-ethylene-propylene copolymer rubber, styrene / acrylonitrile-graft-ethylene-propylene-non-conjugated diene copolymer rubber, styrene / acrylonitrile-graft-ethylene-propylene copolymer rubber, chlorosulfonated polyethylene rubber, silicone rubber, ethylene-vinyl acetate rubber, epichlorohydrin rubber, polysulfide rubber, metallocene catalyst polymerized polyethylene, metallocene catalyst polymerized ethylene-propylene-non-conjugated diene copolymer rubber, and the like can be mentioned. Note that these elastomers can be used singly or in combination of two or more. In addition, latex rubber or the like, which can be used in liquid, can also be used.

[0096] In the present application, the compounding amount of the elastomer added to the resin is preferably in a range not impairing the properties of the thermoplastic resin, i.e., the relationship of mechanical strength, impact strength, and linear expansion coefficient, and is preferably 50% by mass or less, further preferably 30% by mass or less, relative to the resin composite, but is preferably 8% by mass or more, further preferably 13% by mass or more. In the case of a large compounding amount, the improvement in mechanical strength is less, and in the case of a small compounding amount, the improvement in impact strength is less. In addition, the elastomer can be added singly with the thermoplastic resin at the time of the subsequent heating and kneading, or can be added as a blend of the thermoplastic resin and the elastomer prepared in advance.

[0097] In the present application, a compatibilizing resin can also be added together with the cellulose fiber and the thermoplastic resin. The compatibilizing resin refers to a resin that functions to improve the uniform mixing and adhesion of the cellulose fiber and the thermoplastic resin. As the compatibilizing resin used in the present application, a high molecular resin having a carboxylic acid, maleic acid, succinic acid, glutaric acid, or the like, which can form an anhydride, on a polypropylene, polyethylene, or the like, a high molecular resin having a primary amine, secondary amine, amide, or the like, on a polypropylene, polyethylene, or the like, a high molecular resin having a silanol group or the like, on a polypropylene, polyethylene, or the like, and the like are known, and, for example, in the case of use in a polyolefin resin, a resin having maleic anhydride-modified polypropylene (MAPP) or maleic anhydride-modified polyethylene (MAPE) as a main component, or the like is preferably used.

[0098] The amount of the compatibilized resin having the above-mentioned characteristics is preferably 5 to 100 mass% and further preferably 10 to 50 mass% relative to the amount of cellulose. If the amount exceeds 100 mass%, the effects of the present application cannot be exerted due to self-agglomeration of the compatibilized resins.

[0099] In addition, the compatibilized resin can be used alone or as a mixed resin of two or more. In the case of using as a graft of one or two or more polymers and polyolefin, the base resin constituting the graft is not particularly limited, and polyethylene, polypropylene, polybutylene, or the like can be used from the viewpoint of easy production of the graft.

[0100] In addition, the thermoplastic resin used in the present application preferably has an impact strength of a prescribed value or more. Specifically, in the case of using polyolefin as the thermoplastic resin, the impact strength is preferably 10 kJ / m 2 More preferably, 18 kJ / m 2 In the case of using polyamide 6 (nylon 6, PA6) as the thermoplastic resin, the impact strength is preferably 3.0 kJ / m 2 More preferably, 4.0 kJ / m 2 In the case of using polylactic acid (PLA) as the thermoplastic resin, the impact strength is preferably 3.0 kJ / m 2 More preferably, 4.0 kJ / m 2 Here, the impact strength in the present application is a value measured by an Izod impact test (ISO 180) or a Charpy impact strength test (ISO 179-1). For example, the Izod impact test can be performed using an injection molding machine to produce a bar-shaped test piece (10 mm x 80 mm x 4 mm) of a thermoplastic resin or a blend of a thermoplastic resin and an elastomer, and using an Izod impact tester (manufactured by Toyo Seiki Jiki K.K.). Specifically, a notch (cut) of 2 mm in depth is formed in the central portion of the test piece, and a crack is caused to develop from the notch by hitting the notch side with a hammer of appropriate energy, and the impact strength can be calculated. The greater the value of the impact strength, the more excellent the impact strength.

[0101] In addition, the impact strength of the thermoplastic resin can be found by measuring a resin composite formed by mixing and blending components other than cellulose fibers. In addition, in the case where the impact strength of the resin, the elastomer, or the like used is found, the impact strength value can be found by weighted average of the impact strength of the main thermoplastic resin that accounts for 67 mass% or more of the mass of the thermoplastic resin.

[0102] In addition, in the present application, depending on the use, a mineral filler such as talc, calcium carbonate, titanium oxide, glass beads, a fibrous filler such as a whisker, a glass fiber, a carbon fiber, an aramid fiber, a carbon nanotube, or the like, other than the cellulose fiber, can be used in combination. The content ratio of the optional additive is not particularly limited as long as the effect of the present application is not impaired, and is preferably 0.01 to 10% by mass in the resin composite, for example.

[0103] The resin composite of the present application can contain an optional additive, in addition to the above-mentioned thermoplastic resin or blend of a thermoplastic resin and an elastomer, and the cellulose fiber, as necessary. As the optional additive, a low-molecular-weight compatibilizer, a surfactant, a starch, a polysaccharide such as alginic acid, gelatin, animal glue, a natural protein such as casein, tannin, a zeolite, a ceramic, a metal powder, a viscosity modifier, a coloring agent, a plasticizer, a pigment, a dye, an antistatic agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a flame retardant, or the like can be mentioned. The content ratio of the optional additive is not particularly limited as long as the effect of the present application is not impaired, and is preferably 0.01 to 10% by mass in the resin composite, for example.

[0104] (Production of the resin composite)

[0105] The resin composite of the present application is obtained by heat-kneading the above-mentioned thermoplastic resin, the cellulose fiber, and the optional additive used as necessary.

[0106] Here, in order to exert the intended effects of the present application, it is important that the cellulose fiber in an amount corresponding to the thermoplastic resin as the object is uniformly and without segregation filled in the resin composite, and that the most dense packing with the structure homogenized and the structural defects reduced. Therefore, the blending ratio of the thermoplastic resin to the cellulose fiber is also related to the impact strength of the thermoplastic resin used, the degree of defibration of the fiber, and thus cannot be determined generally, for example, by making the cellulose fiber as a whole nanometerized, thereby exerting the effects with a small addition amount, on the other hand, even in the case where the defibration is not performed so strongly, the addition of the cellulose fiber is sufficient, whereby the impact strength is improved. The blending ratio of the thermoplastic resin to the cellulose fiber can be manufactured as 97:3 to 20:80 in terms of the mass ratio in the resin composite, preferably 89:11 to 40:60, more preferably 87:13 to 49:51, and a resin composite excellent in the mechanical strength, the impact strength, and the linear expansion coefficient can be obtained. Further, even in the case where the defibration of the cellulose is not defibrated to the nanometer level, as long as the cellulose fiber is 16% by mass or more in the resin composite, the effects can be exerted, and if it is 21% by mass or more, the effects can be further exerted. When the amount of the cellulose fiber exceeds 51% by mass, the flowability at the time of molding becomes low, the moldability is reduced, and various molding defects occur, and thus it is not preferred, but by including a large amount of the cellulose fiber, the convenience and the economy at the time of transportation are increased, and thus in the case where a master batch of the cellulose fiber used in the present application is used, it can also be used as a high concentration of 51% or more in the amount of the cellulose. It is also known that by using a thermoplastic resin high in the impact strength, even with the same addition amount of the cellulose fiber, the impact strength is improved, and the adjustment of the balance of the mechanical properties, the impact strength, and the linear expansion coefficient required finally can be performed.

[0107] The heating temperature can be adjusted according to the melting point of the thermoplastic resin used. As the heating temperature, the lowest processing temperature recommended by the thermoplastic resin supplier ± about 10°C is preferred. By setting the heating temperature to this temperature range, the thermoplastic resin and the cellulose fiber, and further the optional additive can be uniformly mixed.

[0108] The heating and kneading time can be adjusted within the range recommended by the kneader manufacturer in consideration of the manufacturing amount, the performance of the device, and the operating conditions such as the rotation speed. The shorter the heating time, the more the deterioration due to heat and oxidation at the time of heating and kneading can be prevented, and thus it is preferred, but in the case where the heating time is short, the dispersion in the resin can not be sufficient. Therefore, in the heating and kneading, it is preferred that the configuration of the screw member including the rotor, the kneader, and the like is included to enhance the kneading, and in particular, by using a plurality of rotors, the nanometer defibration can be promoted, and thus it is further preferred.

[0109] In addition, in order to prevent the deterioration due to heat and oxidation at the time of heating and kneading, it is preferred that an antioxidant or the like additive is added, and the kneading is performed under a nitrogen atmosphere.

[0110] As the kneader, a single-screw or multi-screw kneader, preferably a twin-screw kneader, can be used.

[0111] Further, in the present application, the total amount of the thermoplastic resin, the cellulose fiber, and the optional additive used as necessary can be supplied to the kneader at one time, or can be supplied to the kneader in multiple times.

[0112] Further, in the case of supplying in multiple times, a side feeder or the like can be used.

[0113] In order to obtain the resin composite, the number of times of processing in the kneader is not particularly limited, and in the case of multiple processing, the same material can be kneaded multiple times, and further, in the case of multiple processing, the manufacturing can be performed at a high concentration of 30 to 80% of the amount of the cellulose fiber in the initial processing, and the thermoplastic resin, the cellulose fiber, and the optional additive used as necessary are added at each repeated processing, so that the finally obtained resin composite is within the scope of the present application.

[0114] The cellulose fiber used in the present application can use any one of a substance obtained by dry pulverization of the low-basis weight paper subjected to the drying process before the kneading, a substance subjected to wet pulverization by being made in a water-containing state before the pulverization, and a substance obtained by making the substance after the dry pulverization contain water. In the case of using in a dry state, the general existing equipment for resin kneading can be used, and thus it is economical, but in the case of using in a water-containing state, the nanofibrillation is promoted at the time of kneading, and thus a resin composite of higher quality can be produced.

[0115] Note that, before the heat kneading of the thermoplastic resin and the cellulose fiber, the two can be mixed in advance. For example, (i) the crushed product of the low-basis weight paper subjected to the drying process in a dry state can be mixed with the thermoplastic resin, and the obtained mixture can be supplied to the kneader. Alternatively, (ii) the crushed product of the low-basis weight paper subjected to the drying process can be mixed with the thermoplastic resin in a powder or granular state after being dispersed in a dispersion liquid in which they are not dissolved, and the dried substance can be supplied to the kneader. Further, as the mixing means in this case, the use of a bench roll, a Banbury mixer, a kneader, a planetary mixer, a Lodige mixer, a Henschel-type mixer, a stirrer with stirring blades, or a stirrer of a revolution or rotation type can be exemplified.

[0116] In the case of (i), when the crushed product of the low-basis weight paper subjected to the drying process and the thermoplastic resin in a powder or granular state are mixed in advance before the heat kneading, an optional additive can be added.

[0117] (Molded body)

[0118] The resin composite of the present application can be used as a molding material for molding into a desired shape. In molding, the resin composite of the present application can be processed into various shapes such as pellets, scales, powders, sheets, plates, films, and the like.

[0119] As the molding method, injection molding, mold molding, extrusion molding, blow molding, vacuum pressure molding, molding based on a 3D printer, and the like can be given. In addition, molding with physical and chemical foaming can also be performed. As the shape of the molded body, sheets, plates, films, three-dimensional structures, and the like can be given. Various shapes of molded bodies can be produced by the above molding methods according to the use. By using the resin composite of the present application, a molded body having excellent mechanical strength (flexural modulus, flexural strength), impact strength, and linear expansion coefficient can be obtained. That is, in the case where the used thermoplastic resin is polyolefin, for example, a molded body having a flexural modulus of 1.0 GPa or more, an impact strength of 5.0 kJ / m 2 or more, and a linear expansion coefficient of 100 x 10 -6 / K or less can be obtained. In addition, in the case where the used thermoplastic resin is nylon 6 (PA6), for example, a molded body having a flexural modulus of 1.60 GPa or more, an impact strength of 2.0 kJ / m 2 or more, and a linear expansion coefficient of 70 x 10 -6 / K or less can be obtained. In addition, in the case where the used thermoplastic resin is polylactic acid (PLA), for example, a molded body having a flexural modulus of 3.50 GPa or more, an impact strength of 3.0 kJ / m 2 or more, and a linear expansion coefficient of 80 x 10 -6 / K or less can be obtained.

[0120] That is, in the case where the used thermoplastic resin is polyolefin, the resin composite of the present application and the molded body obtained from the resin composite of the present application, which are obtained as described above, preferably have a flexural modulus of 1.00 GPa or more, an impact strength of 5.0 kJ / m 2 or more, and a linear expansion coefficient of 100 x 10 -6 / K or less, more preferably a flexural modulus of 1.6 GPa or more, an impact strength of 9.5 kJ / m 2 or more, and a linear expansion coefficient of 60 x 10 -6 / K or less, further preferably a flexural modulus of 1.8 GPa or more, an impact strength of 10.0 kJ / m 2 or more, and a linear expansion coefficient of 50 x 10 -6 / K or less, particularly preferably a flexural modulus of 2.0 GPa or more, an impact strength of 10.5 kJ / m 2 or more, and a linear expansion coefficient of 40 x 10-6 / K or more, more preferably 30 MPa or more, further preferably 35 MPa or more. In addition, the specific gravity is preferably less than 1.4.

[0121] In addition, in the case where the thermoplastic resin used is nylon 6 (PA6), the resin composite of the present application obtained as described above and the molded body obtained from the resin composite of the present application preferably have a flexural modulus of 1.60 GPa or more, an impact strength of 2.0 kJ / m 2 or more, and a linear expansion coefficient of 70 x 10 -6 or more, more preferably a flexural modulus of 3.00 GPa or more, an impact strength of 2.0 kJ / m 2 or more, and a linear expansion coefficient of 70 x 10 -6 or more. In addition, further to these, the flexural strength is preferably 90 MPa or more, further preferably 100 MPa or more. In addition, the specific gravity is preferably less than 1.4.

[0122] In addition, in the case where the thermoplastic resin used is polylactic acid (PLA), the resin composite of the present application obtained as described above and the molded body obtained from the resin composite of the present application preferably have a flexural modulus of 3.50 GPa or more, an impact strength of 3.0 kJ / m 2 or more, and a linear expansion coefficient of 80 x 10 -6 or more, more preferably a flexural modulus of 4.00 GPa or more, an impact strength of 3.05 kJ / m 2 or more, and a linear expansion coefficient of 70 x 10 -6 or more. In addition, further to these, the flexural strength is preferably 105 MPa or more. In addition, the specific gravity is preferably less than 1.4.

[0123] Note that the flexural modulus and the flexural strength can be measured, for example, as follows.

[0124] That is, using the resin composite of the present application, a bar-shaped test piece (10 mm x 80 mm x 4 mm) was produced by an injection molding machine (Nippon Gohsei Corporation, NPX 7 type, clamp tonnage 7 tons). Specifically, the cylinder temperature of the injection molding machine was set to 170°C (supply part) to 190°C (metering part), the resin composite was melted, and injected into a mold at a temperature of 35°C, to produce a molded body. The test piece obtained was left to stand for 1 day in an atmosphere at a temperature of 23°C and a relative humidity of 50%, and then tested by the following test method.

[0125] As a test method, for the test piece, for example, using a universal testing machine (manufactured by Shimadzu Corporation, AG5000E type), the test conditions were set to a distance between fulcrums of 64 mm and a test speed of 10 mm / min, and a strength test was performed to obtain the bending elastic modulus and the bending strength. Both the bending elastic modulus and the bending strength are the greater the value, the more excellent the mechanical strength.

[0126] In addition, the impact strength is a value measured by an Izod impact test (ISO 180) or a Charpy impact strength test (ISO 179-1). For example, the Izod impact test can be performed using an injection molding machine to produce a bar-shaped test piece (10 mm x 80 mm x 4 mm) of the resin composite of the present application, using an Izod impact testing machine (manufactured by Toyo Seiki Jiki Kogyo Co., Ltd.). Specifically, a notch (cut) of 2 mm in depth is formed in the central portion of the test piece, and a hammer of appropriate energy is used to strike the notch side, allowing a crack to develop from the notch, and the impact strength can be calculated. The greater the value of the impact strength, the more excellent the impact strength.

[0127] In addition, the linear expansion coefficient is the linear expansion coefficient in the range of 30 to 50°C in which the linear expansion coefficient of the resin composite of the present application is the largest among PP-based materials when the temperature is increased from 0°C to 100°C, and can be measured under the conditions specified in ASTM D696. The smaller the value of the measured linear expansion coefficient, the more excellent the dimensional stability.

[0128] In addition, the specific gravity can be measured by a gas displacement method using an AccuPyc II manufactured by Micromeritics Corporation.

[0129] The molded body produced from the resin composite of the present application can be used in fields requiring mechanical strength, impact strength, and linear expansion coefficient. Specifically, it can be used as an interior material, an exterior packaging material, a structural material, or the like for transportation equipment such as automobiles, trains, ships, and airplanes; a housing, a structural material, an internal component, or the like for electronic products such as personal computers, televisions, telephones, and watches; a housing, a structural material, an internal component, or the like for mobile communication equipment such as mobile phones; a housing, a structural material, an internal component, or the like for portable music playback equipment, image playback equipment, printing equipment, copying equipment, sports equipment, and the like; a building material; an office equipment such as stationery; a container; and a container ship.

[0130] Examples

[0131] Hereinafter, the present application will be described in more detail by citing examples and comparative examples, but the present application is not limited to these examples. In addition, in the following, "parts" means a mass basis unless otherwise specified.

[0132] <Measurement method and evaluation method>

[0133] In the examples and comparative examples, the following was performed and evaluated.

[0134] (Measurement of basis weight of paper)

[0135] Measurement of basis weight of paper used

[0136] The paper used in the examples and comparative examples was measured for basis weight by the following method. The paper, whose area was measured in advance, was dried in an oven at 105°C overnight, and then left in a desiccator with a sufficient amount of silica gel for 30 minutes, and then the mass was measured. The measured mass was divided by the area to calculate the basis weight.

[0137] (Mechanical strength test (three-point bending test))

[0138] Method for producing test piece (molded body)

[0139] Using the resin composite obtained in the examples and comparative examples, a bar-shaped test piece (10 mm x 80 mm x 4 mm) was produced by an injection molding machine (Nippon Gohsei Corporation, NPX7 type, clamp tonnage 7 tons). Specifically, the cylinder temperature of the injection molding machine was set to 170°C (feed section) to 190°C (metering section), the resin composite was melted, and injected into a mold at a temperature of 35°C, to produce a molded body. The obtained test piece was left to stand in an atmosphere at a temperature of 23°C and a relative humidity of 50% for 1 day, and then subjected to a test.

[0140] Test method

[0141] For the test piece, a strength test was performed using a universal testing machine (Shimadzu Corporation, AG5000E type). The test conditions were set to a distance between fulcrums of 64 mm and a test speed of 10 mm / min, and the bending elastic modulus and the bending strength were calculated. Both the bending elastic modulus and the bending strength are the greater the value, the more excellent the mechanical strength.

[0142] (Izod impact test)

[0143] Using the resin composite obtained in the examples and comparative examples, a bar-shaped test piece (10 mm x 80 mm x 4 mm) was produced by an injection molding machine (Nippon Gohsei Corporation, NPX7 type, clamp tonnage 7 tons), and an Izod impact test was performed using an Izod impact testing machine (Toyo Seiki Jiki Kogyo Co., Ltd.). Specifically, a notch (cut) having a depth of 2 mm was formed in the central portion of the test piece. A hammer of an appropriate energy was used to strike the notch side, and the impact strength was calculated from the development of a crack from the notch. The greater the value, the more excellent the impact strength.

[0144] In addition, an Izod impact test was also performed on the thermoplastic resin not containing cellulose fibers or the blend of the thermoplastic resin and the elastomer used in the production of the resin composite.

[0145] (line expansion coefficient)

[0146] is the line expansion coefficient (or called the linear thermal expansion coefficient) in the range of 30 to 50°C in which the case of the largest linear thermal expansion coefficient in the PP-based material when the sample is warmed from 0°C to 100°C is the most frequent, and is measured under the conditions prescribed in ASTM D696. The smaller the value, the more excellent the dimensional stability.

[0147] (specific gravity)

[0148] The specific gravity is measured by the gas displacement method using an AccuPyc II manufactured by Micromeritics Corporation.

[0149] (loose bulk density)

[0150] In order to eliminate the aggregation of the fibers, about 50 g of the above pulverized product is put into a prepared bag, air is blown and dispersed (for 30 seconds), and the pulverized product is put into a 1000 cc graduated cylinder until 700 cc, and the weight is measured. The above operation is performed 3 times, and the average of the measured weights is taken as the loose bulk density.

[0151] (compact bulk density)

[0152] In order to eliminate the aggregation of the fibers, about 50 g of the above pulverized product is put into a prepared bag, air is blown and dispersed (for 30 seconds), and the pulverized product is put into a 1000 cc graduated cylinder until 1200 cc (2 times the measurement amount based on the limit position without a scale). Then, the graduated cylinder is fixed in the air, and the bottom is tapped with the palm of the hand 150 times at a frequency of 250 times / minute. Then, the pulverized product is removed to the 600 cc scale of the graduated cylinder, and the weight is measured. The above operation is performed 3 times, and the average of the measured weights is taken as the compact bulk density.

[0153] (fiber length, fiber diameter, and aspect ratio)

[0154] The fiber length and the fiber diameter are found by measuring using a fiber tester (L&W, Fiber Tester Plus (manufactured by Lorentzen & Wettre Corporation)). In addition, the aspect ratio is found by

[0155] (fiber length) / (fiber diameter)

[0156] is found.

[0157] (conveyability of cellulose fibers)

[0158] The cellulose fibers obtained in the examples and the comparative examples are used in a twin-screw kneader (manufactured by TECHNOVEL Corporation, screw diameter 30 mm, L / D 30, and rotation speed 300 rpm) having a feeder, and the conveyability is evaluated. 15mm, L / D45 (L / D is the ratio of screw length L to screw diameter D), cellulose fibers are fed into the feeder from the raw material inlet.

[0159] The horizontal conveying properties of cellulose fibers were visually observed when the feeder flow rate was 0.06 kg / h.

[0160] Furthermore, the cellulose fibers conveyed to the reaction section are fed onto the upper part of the screw, and the feeding operation of the cellulose fibers when the screw is running at a speed of 200 rpm is also visually observed and evaluated according to the following criteria.

[0161] 〇: During a 10-minute visual observation, no blockage of cellulose fibers was observed in either the feeder or the reaction section, indicating good conveying performance.

[0162] ×: During a 10-minute visual observation, clogging of cellulose fibers was observed in at least one of the conveying capacity in the feeder and the input workability in the reaction section, indicating poor conveying workability.

[0163] <Manufacturing of Resin Compounds>

[0164] (Example 1)

[0165] Set the screen aperture of the pulverizing device (UC-360, Horai) to... 2mm, will be used as cellulose fiber in toilet paper (manufactured by Nippon Paper Crecia Co., Ltd., Kleenex, basis weight 21g / m³). 2 The rolled product was crushed to obtain crushed material 1.

[0166] Add 27 parts by dry weight of the above-mentioned pulverized material obtained by pulverization, 68 parts of polypropylene (PP; Prime Polypro J-466HP manufactured by Prime Polymers), and 5 parts of maleic anhydride modified polypropylene (MAPP; TOYOTAC H1000P manufactured by Toyobo Corporation) as a compatibility resin, and stir with a Henschel mixer to obtain the pulverized material.

[0167] The crushed material is fed into a twin-screw mixer (manufactured by TECHNOVEL, screw diameter) without drying. A 15mm diameter, L / D ratio of 45 (L / D is the ratio of screw length (L) to screw diameter (D)), and three rotors in the screw configuration were used in the process. The mixture was heated and kneaded to obtain 100 parts of a resin composite. The barrel temperature of the twin-screw mixer was 160℃. The impact strength of the cellulose-free thermoplastic resin was 80kJ / m². 2 .

[0168] The obtained resin composite was used to prepare strip test pieces, which were then used for mechanical strength testing, Izod impact testing, and linear expansion coefficient determination. The results are shown in Table 1.

[0169] (Example 2)

[0170] The toilet paper used for shredding was changed from a roll to a Henschel shredded product, but otherwise shredded in the same manner as in Example 1, resulting in shredded material 2.

[0171] Here, the Henschel crushed product is prepared using a Henschel mixer (Nippon Coke Industry Co., Ltd., FM150 model) and toilet paper (Nippon Paper Crecia Co., Ltd., Kleenex, basis weight 21 g / m³). 2 The material was obtained by processing at 20 m / s for 2 minutes, followed by processing at 80 m / s for 2 minutes, and this process was repeated twice.

[0172] In addition, except that the pulverized material 1 was replaced with pulverized material 2, the resin compound was obtained in the same manner as in Example 1.

[0173] The obtained resin composite was used to prepare strip test pieces, which were then used for mechanical strength testing, Izod impact testing, and linear expansion coefficient determination. The results are shown in Table 1.

[0174] (Example 3)

[0175] In addition to changing the screen aperture during crushing... Beyond 20 mm, the material was pulverized in the same manner as in Example 2 to obtain pulverized material 3. Furthermore, except that pulverized material 2 was replaced with pulverized material 3, a resin composite was obtained in the same manner as in Example 2.

[0176] The obtained resin composite was used to prepare strip test pieces, which were then used for mechanical strength testing, Izod impact testing, and linear expansion coefficient determination. The results are shown in Table 1.

[0177] (Comparative Example 1)

[0178] Prepare 27 parts by dry weight of the above-mentioned toilet paper in Henschel powder, add 68 parts of polypropylene (PP; Prime Polypro J-466HP, manufactured by Prime Polymers) and 5 parts of maleic anhydride-modified polypropylene (MAPP; TOYOTAC H1000P, manufactured by Toyobo Corporation) as a compatibility resin, and stir using a Henschel mixer to obtain the powder. It should be noted that water is not added.

[0179] The crushed material is fed into a twin-screw mixer (manufactured by TECHNOVEL, screw diameter) without drying. 15 mm, L / D 45 (L / D is the ratio of the screw length (L) to the screw diameter (D)), using 3 rotors in the screw configuration, to perform heat kneading, to obtain a resin composite 100 parts. The temperature of the cylinder of the twin-screw kneader was 160°C. The impact strength of the thermoplastic resin not containing the cellulose fiber was 80 kJ / m 2 .

[0180] Using the obtained resin composite, a bar test piece was produced, and supplied to a mechanical strength test, an Izod impact test, a linear expansion coefficient measurement. The results are shown in Table 1.

[0181] [Table 1]

[0182] As shown in Table 1, the resin composite containing the thermoplastic resin and the cellulose fiber, and the raw material of the main component of the cellulose fiber being a base weight of 100 g / m 2 The mechanical strength test, the Izod impact test, and the linear expansion coefficient measurement of the resin composite of the following low base weight paper are excellent, and particularly in the case where the cellulose fiber is a pulverized product further subjected to a pulverization treatment process, further conveyability is also excellent.

Claims

1. A resin composite comprising a thermoplastic resin and cellulose fibers, wherein, The main component of the cellulose fiber is a raw material with a basis weight of 100g / m³ after a drying process. 2 The following are low-basic-weight papers.

2. The resin composite according to claim 1, characterized in that, The cellulose fibers are pulverized materials that have undergone a pulverization process.

3. The resin composite according to claim 1 or 2, characterized in that, The cellulose fibers are pulverized materials with a loose bulk density in the range of 10 to 60 g / L.

4. The resin composite according to claim 1 or 2, characterized in that, The cellulose fibers are pulverized materials with a compacted bulk density in the range of 15 to 80 g / L.

5. The resin composite according to claim 1 or 2, characterized in that, The cellulose fibers are composed of (Aspect ratio of cellulose fibers in the pulverized material) / (Aspect ratio of cellulose fibers before pulverization) × 100% (%) The aspect ratio is maintained at over 60%.

6. The resin composite according to claim 1 or 2, wherein, The low-basic-weight paper has a basic weight of 3-40 g / m³. 2 Thin sheets of paper.

7. The resin composite according to claim 1 or 2, wherein, The low-basic-weight paper is household thin paper.

8. The resin composite according to claim 1 or 2, characterized in that, The thermoplastic resin is a polyolefin or a blend of polyolefin and elastomer, with a flexural modulus of elasticity of 1.00 GPa or higher and an impact strength of 5.0 kJ / m. 2 The above, and the coefficient of linear expansion is 100×10. -6 / K or below.

9. The resin composite according to claim 1 or 2, wherein, The thermoplastic resin has an impact strength of 3.0 kJ / m. 2 The above-mentioned nylon may be a blend of nylon and elastomer.

10. The resin composite according to claim 1 or 2, characterized in that, The thermoplastic resin is nylon or a blend of nylon and elastomer, with a flexural modulus of elasticity of 1.60 GPa or higher and an impact strength of 2.0 kJ / m. 2 The above, and the coefficient of linear expansion is 70×10. -6 / K or below.

11. The resin composite according to claim 1 or 2, wherein, The thermoplastic resin has an impact strength of 3.0 kJ / m. 2 The above polylactic acid may be a blend of polylactic acid and elastomer.

12. The resin composite according to claim 1 or 2, characterized in that, The thermoplastic resin is polylactic acid or a blend of polylactic acid and an elastomer, with a flexural modulus of elasticity of 3.50 GPa or higher and an impact strength of 3.0 kJ / m. 2 The above, and the coefficient of linear expansion is 80×10. -6 / K or below.

13. A method for manufacturing a resin composite, characterized in that, It has the following processes (A) to (C), Process (A): The raw pulp is fed to the papermaking and drying processes to obtain a basis weight of 100 g / m³. 2 The following are the processes for producing low-basic heavy paper. Process (B): A process of shredding the low-basic-weight paper that has undergone process (A). Step (C): The process of mixing low-basic-weight paper that has been pulverized in step (B) with thermoplastic resin and then heating and kneading it.

14. The method for manufacturing the resin composite according to claim 13, characterized in that, The process (B) involves pulverizing the low-basic-weight paper in such a way that the loose bulk density is in the range of 10 to 60 g / L.

15. The method for manufacturing the resin composite according to claim 13 or 14, characterized in that, The process (B) involves pulverizing the low-basic-weight paper in such a way that the compact bulk density is in the range of 15 to 80 g / L.

16. The method for manufacturing the resin composite according to claim 13 or 14, characterized in that, The process (B) is carried out by (Aspect ratio of the low-basic-weight paper after shredding) / (Aspect ratio of the low-basic-weight paper before the shredding process) × 100% (%) The powder is processed in a way that maintains an aspect ratio of over 60%.

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