JP2008037022A - Case injection molding method for lignocellulosic resin composition and lignocellulosic resin composition - Google Patents

Abstract

A casing injection molding method for lignocellulosic resin composition and a lignocellulosic resin composition that can be molded from a lignocellulosic resin composition by injection molding and the production efficiency thereof can be improved. To provide.
According to the method for manufacturing the casing 100 of the present invention, the kneading step (S5) is performed after the steam treatment step (S2) and before the molding step (S8), and the kneading step. In (S5), the total weight of the kneaded mixture of the biodegradable resin and the lignocellulosic material in which the lignocellulosic modifier is produced is added to the lignocellulosic material in which the lignocellulosic material is produced. The biodegradable resin and the lubricant are kneaded at a ratio of 5% by weight or more. Thereby, since the fluidity | liquidity of the lignocellulose type material in which the lignocellulose type modifier was produced | generated can be improved and the housing | casing 100 can be manufactured by injection molding, compared with the case where the housing | casing 100 is manufactured by compression molding. The production efficiency can be improved.
[Selection] Figure 1

Description

  The present invention relates to a casing injection molding method for lignocellulosic resin composition and a lignocellulosic resin composition, and in particular, the casing can be molded from a lignocellulosic resin composition by injection molding to improve its production efficiency. The present invention relates to a case injection molding method for a lignocellulosic resin composition and a lignocellulosic resin composition.

  Generally, wastes such as waste materials of houses and furniture, waste paper, cut leaves and fallen leaves are made of lignocellulosic materials containing hemicellulose, lignin and cellulose, and the waste is reused, that is, lignocellulosic materials. Various attempts have been made to reuse resources to effectively use resources.

  For example, in JP-A-2004-43529 (Patent Document 1), a wood resin (lignocellulose material) having a bulk specific gravity of 0.2 or more is blended with an olefin-based synthetic resin to prepare a molding resin composition. The technology is described.

  According to this technique, since the bulk specific gravity of the wood powder is set to 0.2 or more, the wood powder can be uniformly dispersed in the olefin synthetic resin. As a result, since the ratio of the wood powder mix | blended with the resin composition for shaping | molding can be raised, the effective utilization of wood powder can be aimed at that much.

  By the way, as for the molded object shape | molded from the resin composition for shaping | molding mentioned above, intensity | strength falls by the amount which a lignocellulosic material is mix | blended. As a result, it is not possible to use a molded body molded from the molding resin composition on a member that requires strength, such as a rotating body such as a gear, and there is a problem that the application range of such a molded body is limited. there were.

  Therefore, Japanese Patent Application Laid-Open No. 2004-261967 (Patent Document 2) describes a technique in which a lignocellulosic material is steam-treated to produce a lignocellulosic modifier, and the lignocellulosic modifier is molded. ing.

  According to this technique, the lignocellulosic modifiers adhere to each other by the adhesive force of the lignocellulosic modifier. As a result, the lignocellulosic molded body molded from the lignocellulosic modifier can ensure high strength, and accordingly, the applicable range of the lignocellulosic molded body can be expanded.

Further, for example, Japanese Patent Application Laid-Open No. 2005-200614 (Patent Document 3) discloses a technique for obtaining a polyolefin resin composition that is a resin composition containing a wood-based material and has excellent impact strength. Yes.
JP 2004-43529 A (paragraph [0013], FIG. 1 etc.) JP 2004-261967 (paragraph [0007]) JP 2005-200614 A

  By the way, this lignocellulosic molded product is manufactured by compression molding or extrusion molding because of the low flowability of the lignocellulosic modifier, and is mass-produced injection like a molded product molded from a molding resin composition. It cannot be manufactured by molding. For example, in the technique of Patent Document 3 described above, when the amount of lignocellulosic material exceeds 80 parts by weight, heat generation during kneading and molding increases, and kneading and molding cannot be performed (see paragraph [0022 of Patent Document 3). ]).

  Therefore, the lignocellulose-based molded article has a problem that the production efficiency is low as compared with a molded article molded from the molding resin composition. Moreover, when the ratio of lignocellulosic material becomes high, there existed a problem that it became weak to an impact or a bending.

  The present invention has been made to solve the above-described problems, and the lignocellulosic resin composition capable of improving the production efficiency by allowing the casing to be molded from the lignocellulosic resin composition by injection molding. It is an object of the present invention to provide a case injection molding method and a lignocellulosic resin composition.

  In order to achieve this object, a casing injection molding method for a lignocellulosic resin composition according to claim 1 includes a pulverizing step of pulverizing a lignocellulosic material containing at least hemicellulose, lignin and cellulose, and the pulverizing step. A steam treatment step for producing a lignocellulosic modifier by steam-treating the lignocellulosic material crushed by the step, and the lignocellulosic material in which the lignocellulosic modifier is produced in the steam treatment step. A molding step of molding a casing by an adhesive force of the lignocellulose-based modifier, and the lignocellulose in the steam treatment step after the steam treatment step and before the molding step. A mixing step of mixing a biodegradable resin and a lubricant with the lignocellulosic material from which a system modifier is produced In the mixing step, the ratio of the biodegradable resin and the lubricant is 1% by weight or more based on the total weight of the mixture of the biodegradable resin and the lignocellulosic material from which the lignocellulosic modifier is generated. In the molding step, a mixture of the biodegradable resin and lubricant mixed in the mixing step and the lignocellulosic material from which the lignocellulosic modifier is produced is injection molded. Is.

  The case injection molding method of the lignocellulosic resin composition according to claim 2 is the case injection molding method of the lignocellulosic resin composition according to claim 1, wherein the molding step is performed after the mixing step. Before the step, a deaeration step of removing moisture or pyrolysis gas contained in the lignocellulosic material from which the lignocellulosic modifier is generated is provided.

  The casing injection molding method of the lignocellulose-based resin composition according to claim 3 is the casing injection molding method of the lignocellulose-based resin composition according to claim 1 or 2, after the steam treatment step, and Before the mixing step, there is provided a pulverizing step for finely pulverizing the lignocellulosic material from which the lignocellulosic modifier is produced.

  The casing injection molding method of the lignocellulose-based resin composition according to claim 4 is the casing injection molding method of the lignocellulose-based resin composition according to any one of claims 1 to 3, wherein the biodegradable resin is It is composed of an aliphatic polyester resin.

  The casing injection molding method of the lignocellulosic resin composition according to claim 5 is the casing injection molding method of lignocellulosic resin composition according to claim 4, wherein the biodegradable resin is a polylactic acid resin. It is configured.

  The lignocellulosic resin composition according to claim 6, wherein the lignocellulosic modifier is produced by pulverizing and steaming a lignocellulosic material containing at least hemicellulose, lignin and cellulose. 40 to 100 parts by weight of the lignocellulosic material in which the lignocellulosic modifier is produced, and more than 0 parts by weight and 60 parts by weight or less (B) polyester 1 to 10 parts by weight of (C) oligomer-based lubricant with respect to 100 parts by weight of the biodegradable resin and the mixture of (A) and (B).

  According to the case injection molding method of the lignocellulosic resin composition according to claim 1, the lignocellulosic material containing at least lignin and cellulose is pulverized by the pulverization step. The pulverized lignocellulosic material is subjected to steam treatment in a steam treatment step, and a lignocellulose-based modifier is generated. The lignocellulosic material from which the lignocellulosic modifier is produced is molded by the adhesion of the lignocellulosic modifier in the molding process. As a result, the housing is manufactured.

  Here, after the steam treatment step and before the molding step, a mixing step is performed. In the mixing step, the lignocellulosic material in which the lignocellulosic modifier is generated is added to the biodegradable resin and The biodegradable resin and the lubricant are mixed at a ratio of 1% by weight or more based on the total weight of the mixture of the lubricant and the lignocellulosic material in which the lignocellulosic modifier is produced. Therefore, there exists an effect that the fluidity | liquidity of the lignocellulose type material in which the lignocellulose type modifier was produced | generated can be improved.

  That is, when the mixing ratio of the biodegradable resin and the lubricant is less than 1% by weight with respect to the total weight of the mixture, the fluidity of the mixture is low, and the mixture cannot flow out from the nozzle of the injection molding machine. That is, the casing cannot be manufactured by injection molding.

  On the other hand, in the production method of the present invention, the lignocellulose-based modifier produced by mixing the biodegradable resin and the lubricant at a ratio of 1% by weight or more with respect to the total weight of the mixture. The fluidity of the material can be improved. As a result, the mixture can be discharged from the nozzle of the injection molding machine, that is, the casing can be manufactured by injection molding, so that the manufacturing efficiency of the casing is improved compared to the case of manufacturing the casing by compression molding. There is an effect that can be made.

  The casing is manufactured from a mixture of a biodegradable resin and a lignocellulosic material in which a lignocellulosic modifier is produced, so it is biodegraded into water and carbon dioxide by natural microorganisms and degrading enzymes. In other words, return to the soil harmlessly. Therefore, the casing manufactured by the manufacturing method of the present invention has an effect that the load on the environment can be reduced as compared with the casing manufactured by plastic.

  In addition, the housing manufactured from a mixture of biodegradable resin and lignocellulosic material in which lignocellulosic modifiers are produced does not generate dioxins or other harmful gases during incineration, thus preventing air pollution. There is an effect that the load on the environment can be reduced.

  In addition, since the casing manufactured by the manufacturing method of the present invention is molded by the adhesive force of the lignocellulosic modifier, compared to the case where the lignocellulosic material is blended with the resin and molded, There exists an effect that the intensity | strength of a housing | casing can be ensured.

  In addition, the mixture of the biodegradable resin and the lignocellulosic material in which the lignocellulosic modifier is produced has a higher glass transition temperature than the biodegradable resin, and therefore shortens the time required for molding. Can do. Therefore, the production method of the present invention has an effect that the production efficiency can be improved as compared with the case where the housing is produced using only the biodegradable resin.

  According to the case injection molding method of the lignocellulosic resin composition according to claim 2, in addition to the effect exhibited by the case injection molding method of the lignocellulosic resin composition according to claim 1, after the mixing step, In addition, since there is a deaeration step for removing moisture or pyrolysis gas contained in the lignocellulosic material from which the lignocellulosic modifier is generated before the molding step, moisture or heat is removed from the mixture before molding. The cracked gas can be removed.

  Here, when the mixture contains moisture, the moisture evaporates due to heat during molding, and the casing is cracked or distorted. In addition, when the mixture contains a pyrolysis gas, bubbles are generated in the mixture, and the casing is cracked or distorted. On the other hand, the production method of the present invention includes a degassing step for removing moisture or pyrolysis gas contained in the lignocellulosic material from which the lignocellulosic modifier is generated. There is an effect that it is possible to remove the moisture or the pyrolysis gas and to prevent the casing from being cracked or distorted.

  In addition, moisture or pyrolysis gas can be removed from the mixture before molding by the deaeration process, which suppresses increase in molding shrinkage due to moisture evaporation and pyrolysis gas bubbles, and molds a highly accurate housing. There is an effect that can be done.

  According to the case injection molding method of the lignocellulosic resin composition according to claim 3, in addition to the effect of the case injection molding method of the lignocellulosic resin composition according to claim 1 or 2, a steam treatment step And before the mixing step, there is provided a pulverization step for finely pulverizing the lignocellulose-based material from which the lignocellulose-based modifier has been produced, so that the lignocellulose-based modifier has been produced. The effect of improving the fluidity of the cellulosic material and allowing the mixture of the biodegradable resin and the lignocellulosic material produced with the lignocellulosic modifier to flow out from the nozzle of the injection molding machine reliably. is there.

  According to the case injection molding method of the lignocellulosic resin composition according to claim 4, in addition to the effect exhibited by the case injection molding method of the lignocellulosic resin composition according to any one of claims 1 to 3, Since the biodegradable resin is composed of a polyester resin that is a general-purpose resin, the cost of the biodegradable resin can be reduced, and the manufacturing cost of the casing can be reduced correspondingly.

  In addition, when the biodegradable resin is composed of a petroleum-based polyester-based resin, it is possible to ensure the strength of the casing as compared with the case where the plant-based polylactic acid-based resin is mixed and manufactured. There is an effect that can be done.

  The polylactic acid-based resin may be hydrolyzed by an acid such as acetic acid generated when the lignocellulosic material is steam-treated. On the other hand, since the petroleum-based polyester resin is stable against acids such as acetic acid, the fluidity of the lignocellulosic material in which the lignocellulosic modifier is generated can be reliably improved. There is an effect.

  According to the case injection molding method of the lignocellulosic resin composition according to claim 5, in addition to the effect exhibited by the case injection molding method of the lignocellulosic resin composition according to claim 4, the biodegradable resin is: Since it is composed of a polylactic acid resin which is a non-petroleum resource, there is an effect that it is possible to prevent the fossil fuel from being depleted without using fossil fuel.

  According to the lignocellulosic resin composition according to claim 6, the lignocellulosic material in which 40 to 100 parts by weight of the (A) lignocellulosic modifier is produced, and more than 0 parts by weight and 60 parts by weight or less. (B) In addition to the polyester-based biodegradable resin, (C) the oligomer-based lubricant comprises (A) a lignocellulose-based material in which a lignocellulosic modifier is generated, and (B) a polyester-based biodegradable resin. 1 to 10 parts by weight is added to 100 parts by weight of the mixture.

  The “(A) lignocellulosic material produced with a lignocellulose-based modifier” is a lignocellulosic material produced by pulverizing and steaming a lignocellulosic material containing at least hemicellulose, lignin and cellulose. It is a lignocellulose material containing a cellulosic modifier. Further, “(B) polyester-based biodegradable resin” includes petroleum-based aliphatic or aromatic polyester-based resins.

  Addition of (C) oligomeric lubricant by adding (C) oligomeric lubricant in a ratio of 1 to 10 parts by weight with respect to 100 parts by weight of the mixture of component (A) and component (B) The dispersibility of the (B) polyester-based biodegradable resin with respect to the lignocellulosic material from which the (A) lignocellulosic modifier was generated can be improved without causing stickiness due to the above. As a result, the fluidity of the lignocellulosic resin composition containing the lignocellulosic material from which the lignocellulosic modifier is produced can be improved, and the fluidity sufficient to flow out from the nozzle of the injection molding machine. There is an effect that can be obtained. That is, there is an effect that it is possible to manufacture a casing by injection molding the lignocellulose-based resin composition according to claim 6.

  A casing manufactured by injection molding the lignocellulosic resin composition according to claim 6 is manufactured from a mixture of a biodegradable resin and a lignocellulosic material in which a lignocellulosic modifier is produced. Therefore, it can be biodegraded into water and carbon dioxide by natural microorganisms and degrading enzymes and returned to the soil harmlessly. Therefore, such a lignocellulosic resin composition has an effect that it is useful as a material that can reduce the load on the environment as compared with plastics and the like.

  The lignocellulose-based resin composition according to claim 6 includes (B) a polyester-based biodegradable resin as a biodegradable resin. By using a polyester-based resin that is a general-purpose resin, a lignocellulose-based resin composition is used. Since the cost of the resin composition can be reduced, for example, when the casing is manufactured by injection molding the lignocellulosic resin composition, the casing is made by an amount corresponding to the reduced cost of the lignocellulosic resin composition. The manufacturing cost can be reduced.

  Here, especially when the polyester-based biodegradable resin is composed of a petroleum-based polyester-based resin, the strength of the housing is higher than when the plant-based polylactic acid-based resin is mixed. There is an effect that can be secured.

  In addition, when the polyester biodegradable resin is composed of a petroleum polyester resin, it is stable against acids such as acetic acid, so it depends on the acid generated when the lignocellulosic material is steam-treated. Since acid hydrolysis is suppressed, there is an effect that the fluidity of the lignocellulosic material in which the lignocellulosic modifier is generated can be reliably improved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a process diagram of a method for manufacturing a casing 100 of the present invention. First, a method for manufacturing the housing 100 will be described with reference to FIG.

  As shown in FIG. 1, in the manufacturing method of the housing 100 (see FIG. 3), first, in the pulverization step (S1), the lignocellulosic material is pulverized, specifically, pulverized wood. Such wood is preferably finely divided so that the steam treatment in the steam treatment step (S2) to be described later can be performed uniformly, and the time required for the steam treatment by subdividing the wood is reduced. Can be shortened.

  Specifically, the pulverized wood preferably has a thickness of 1 mm or less and a flat area of 5 cm × 5 cm or less, and a thickness of 0.5 mm or less and a flat area of 2 cm × 2 cm or less. Is more preferable.

  The “lignocellulose-based material” described in claim 1 corresponds to a material containing at least hemicellulose, lignin and cellulose. Such lignocellulosic materials include, for example, various trees, bamboo, kenaf, corn, sugarcane, hemp, and other vegetation, and also include industrial waste such as house demolition, furniture demolition, and wood waste.

  Next, after the pulverization step (S1) is executed, the pulverized wood is steamed in the steam treatment step (S2). Such steam treatment is performed by spraying heated water vapor on the wood in the pressure vessel under high temperature and high pressure. The molecular bond of hemicellulose and lignin contained in the wood is cut (decomposed), and the lignocellulose-based modification is performed. Produce material.

  The “lignocellulose-based modifier” according to claims 1 to 3 contains a hemicellulose-based degradation component in which the molecular bond of hemicellulose is cleaved and a lignin-type degradation component in which the molecular bond of lignin is cleaved. The composition is applicable.

  Such a hemicellulose-based decomposition component has self-adhesive properties, and the lignin-based decomposition component has thermoplasticity. Thereby, a lignocellulose-type modifier functions as a thermoplastic material which can be fluidized by heating.

  The steam treatment temperature is preferably set in the range of 110 ° C. or higher and 230 ° C. or lower, and more preferably in the range of 150 ° C. or higher and 230 ° C. or lower. Thereby, while promoting the hydrolysis of hemicellulose and lignin, side reactions such as decomposition condensation can be suppressed.

  Next, after performing the steam treatment step (S2), in the drying step (S3), the lignocellulosic material in which the lignocellulose-based modifier is generated is dried. In such drying, air or heat is applied to the lignocellulosic material from which the lignocellulosic modifier is generated, and the water contained in the lignocellulosic material is rapidly evaporated.

  In this way, by rapidly evaporating the water contained in the lignocellulosic material from which the lignocellulosic modifier is generated, it is possible to suppress the gradual separation of water-soluble decomposition components along with moisture, A large amount can remain in the cellulosic material.

  Next, after the drying step (S3) is performed, the lignocellulosic material from which the lignocellulose-based modifier is produced is finely pulverized in the fine pulverization step (S4). In the fine pulverization, the lignocellulosic material in which the lignocellulosic modifier is generated is pulverized so as to be smaller than the particle size of the lignocellulosic material pulverized in the pulverization step (S1). Thus, the fluidity | liquidity of the lignocellulosic material at the time of a fusion | melting can be improved by pulverizing the lignocellulosic material in which the lignocellulosic modifier was produced | generated.

  The particle size of the finely pulverized lignocellulosic material is specifically set to 1500 μm or less, preferably a particle size of 1000 μm or less, and more preferably a particle size of 500 μm or less.

  Next, after the fine pulverization step (S4) is performed, in the kneading step (S5), the polylactic acid-based resin and the lignocellulose-based material in which the lignocellulose-based modifier is generated are kneaded. The kneading ratio of the polylactic acid-based resin is 1% by weight or more and 50% by weight with respect to the total weight of the kneaded material of the polylactic acid-based resin and the lignocellulosic material in which the lignocellulose-based modifier is generated. % Is set within the range.

  Here, when the kneading ratio of the polylactic acid-based resin is smaller than 1% by weight with respect to the total weight of the kneaded product, the kneaded product has low fluidity, and the kneaded product is obtained from a nozzle 5a (see FIG. 2) described later. It cannot be drained.

  On the other hand, by setting the kneading ratio of the polylactic acid resin to 1% by weight or more with respect to the total weight of the kneaded product, the fluidity of the lignocellulosic material in which the lignocellulose-based modifier is generated is improved. be able to. As a result, the kneaded material can be discharged from the nozzle 5a, that is, the casing 100 can be injection-molded, so that the manufacturing efficiency of the casing 100 can be improved as compared with the case where the casing 100 is compression-molded. it can.

  On the other hand, when the kneading ratio of the polylactic acid-based resin is larger than 50% with respect to the total weight of the kneaded product, the content of the hemicellulose-based decomposition component having self-adhesiveness is reduced, and the strength of the casing 100 is correspondingly reduced. Is reduced. In addition, since the kneading amount of the high-cost polylactic acid resin increases, the manufacturing cost of the housing 100 increases accordingly.

  On the other hand, by setting the kneading ratio of the polylactic acid resin to 50% by weight or less with respect to the total weight of the kneaded product, the content of the hemicellulose-based decomposition component is suppressed from being reduced, and accordingly, the housing It can suppress that the intensity | strength of 100 reduces.

  Also, by setting the kneading ratio of the polylactic acid resin to 50% by weight or less with respect to the total weight of the kneaded product, the kneading amount of the polylactic acid resin is reduced, and the manufacturing cost of the casing 100 is reduced accordingly. can do.

  Next, after the kneading step (S5) is executed, the kneaded product is formed into pellets in the pellet forming step (S6). The particle size of the pellet is not particularly limited, and can be changed according to the size of an injection molding machine 1 (see FIG. 2) to be described later.

  In this embodiment, the kneaded material formed into a pellet is configured to be put into a hopper 3 (see FIG. 2) to be described later. However, the present invention is not necessarily limited to this and is formed into a pellet. The previous kneaded product may be put directly into the hopper 3.

  Next, after the pellet forming step (S6) is executed, the kneaded product is deaerated in the deaeration step (S7). Such deaeration is performed by a vent mechanism, in which a kneaded product is put into a vacuum pressure vessel that is evacuated, and moisture contained in the kneaded product and a pyrolysis gas generated during heating are removed.

  Here, when the kneaded material before molding contains moisture, the moisture evaporates due to heat during molding, and cracks and distortion occur during molding of the housing 100. In addition, when the kneaded material contains a pyrolysis gas, bubbles are generated in the kneaded material, and cracks and strains occur when the casing 100 is molded. On the other hand, as described above, in the deaeration step (S7), it is possible to suppress the occurrence of cracks and distortions in the housing 100 by removing moisture and pyrolysis gas contained in the kneaded product.

  Furthermore, in the degassing step (S7), the moisture contained in the kneaded product and the pyrolysis gas generated during heating can be removed, thereby suppressing the increase in molding shrinkage due to moisture evaporation and pyrolysis gas bubbles. A highly accurate housing 100 can be formed.

  Next, after performing the deaeration process (S7), in the molding process (S8), the lignocellulosic material in which the lignocellulosic modifier is generated is injection molded. In the molding step (S8), the injection molding machine 1 is used. Here, with reference to FIG. 2, the detailed structure of the injection molding machine 1 is demonstrated.

  FIG. 2 is a front view schematically showing the injection molding machine 1. As shown in FIG. 2, an injection molding machine 1 is a device for injecting a fluidized injection into a mold and molding the frame 2, a hopper 3, an injection cylinder 4, a cylinder 5, and a band heater. 6, a fixed platen 7, a mold 8, a movable platen 9, and a mold clamping cylinder 10.

  The frame 2 is a pedestal for mounting an injection cylinder 4, a cylinder 5, a fixed plate 7, a movable plate 9, and a mold clamping cylinder 10, which will be described later, and is made of a high-strength material that can withstand the forces and vibrations generated in various places. It is configured.

  The hopper 3 is a substantially conical storage container for supplying an injection product to the cylinder 5, and an upper portion thereof is formed with an opening, and a tip thereof is connected to the cylinder 5. Then, the injected material is supplied from the upper part of the hopper 3 and supplied to the cylinder 5. The injection cylinder 4 is a hydraulic cylinder for rotating a screw (not shown) built in the cylinder 5.

  The cylinder 5 is for transporting, heating and melting the injection, and injecting it, and melts the injection by shearing heat of a screw built in the cylinder 5 and heating of a band heater 6 described later. Then, the injection cylinder 4 advances the screw to the nozzle 5a side (left side in FIG. 2), which will be described later, and injects the injection from the nozzle 5a.

  The nozzle 5a is an injection port connected to the tip of the cylinder 5 for injecting an injection product, and is in close contact with the fixed mold 8a at the time of injection to form a flow path for the injection product. In the injection process, it is desirable to perform filling at a high speed in order to minimize the change in the viscosity of the injection product due to cooling during filling.

  For this reason, the nozzle 5a is set to have a small opening size, and injects an injection with a high pressure. As described above, the nozzle 5a is set to have a small opening size. As described above, the lignocellulosic material in which the lignocellulose-based modifier is generated is mixed with the biodegradable resin to thereby produce lignocellulose. It is possible to improve the fluidity of the lignocellulosic material from which the cellulosic modifier is produced, and to injection mold the lignocellulosic material.

  The band heater 6 is a heat generating member for heating the cylinder 5, and is wound around the outer periphery of the cylinder 5. The fixed platen 7 is for supporting a fixed-side mold 8a described later on one end surface side (left side in FIG. 2), and is fixed to the upper surface of the frame 2. The nozzle 5a comes into contact with the fixed mold 8a through a hole penetratingly formed in the center.

  The mold 8 is for molding the injection into the shape of a casing 100 (see FIG. 3) to be described later. The mold 8 is provided on a fixed-side mold 8a disposed on the fixed platen 7 and a movable platen 9 to be described later. The movable side mold 8b is provided. And the internal space which these fixed side and movable side metal mold | die 8a, 8b form is formed in the same shape as the housing | casing 100, and the injection material with which the internal space was filled is shape | molded in the shape of the housing | casing 100. FIG.

  Here, the housing | casing 100 shape | molded with this metal mold | die 8 is demonstrated with reference to FIG.3 and FIG.4. 3 is a perspective view of the casing 100, and FIG. 4 is a photograph of the injection molded casing and an Izod impact test piece. Note that the casing 100 may be provided with a lightening portion for reducing weight and a handle for facilitating carrying on the side wall portion 102.

  The housing 100 is a storage container for storing a workpiece. As shown in FIG. 3, the housing 100 includes a substantially rectangular bottom surface portion 101, and a side wall portion 102 erected upward from the end of the bottom surface portion 101 (upward in FIG. 3). The workpiece can be put in from the opening formed by the upper end of the side wall portion 102 so that the workpiece can be stored therein.

  As the dimensions of the housing 100, for example, the bottom surface portion 101 is set to a size of 50 cm × 90 cm, the height of the side wall portion 102 is set to 40 cm, and the thickness of the thickest part is set to 15 mm. The case where the thickness of the thinnest part is set to 5 mm is illustrated as an example.

  Here, the general housing is made of plastic. A casing made of this plastic is not preferable from the viewpoint of the global environment, such as the use of fossil fuels and the generation of harmful gases during disposal / incineration. In addition, when the casing is made of polylactic acid resin, which is a biodegradable resin, the environmental load can be reduced, but because the glass transition temperature is very low, it takes time to mold and the production efficiency is low. There is a problem. In particular, since the casing 100 is increased in size to accommodate a workpiece, a difference in glass transition temperature has a great influence on manufacturing efficiency as compared with a case where a small molded body is molded.

  On the other hand, since the casing 100 of the present invention is composed of a lignocellulose-based injection-molded body, it has a higher glass transition temperature than the case where it is composed of a polylactic acid-based resin. It can be shortened. That is, the casing 100 is made of a lignocellulose-based injection-molded body, whereby the production efficiency can be improved while reducing the load on the global environment.

  Here, the physical property values of the housing 100 will be described with reference to FIG. FIG. 5 is a diagram illustrating physical property values of the housing 100. The water absorption rate shown in the A4 column indicates the water absorption rate of the housing 100 when the housing 100 is immersed in water at a temperature of 23 ° C. for 24 hours.

  As shown in the A1 column, the Izod impact value of the housing 100 is 4.5 kJ / m 2.

  Next, as shown in the A2 column, the bending strength of the housing 100 is 74 MPa, and it can be said that the bending strength that can withstand practical use is secured. Similarly, as shown in the A3 column, the bending elastic modulus of the casing 100 is 11000 MPa, and it can be said that the bending elastic modulus that can withstand practical use is secured.

  Next, as shown in the A4 column, the water absorption rate of the lignocellulose-based injection-molded product is 1.6%. Therefore, it can be said that the casing 100 has a long life because it absorbs excessive water and is not hydrolyzed.

  Here, with reference to FIG. 2 again, the detailed configuration of the injection molding machine 1 will be described. The movable platen 9 is for supporting the movable side mold 8b disposed on the other end face side (right side in FIG. 2). The movable platen 9 is guided in a horizontal direction ( It is configured to be able to move forward and backward in the left-right direction in FIG.

  The mold clamping cylinder 10 is a hydraulic cylinder for moving the movable platen 9 back and forth. When the mold clamping cylinder 10 is extended, the movable platen 9 is advanced to move the movable die 8b to the fixed die 8a. Make contact. On the other hand, when the mold clamping cylinder 10 is contracted, the movable platen 9 is moved backward to move the movable mold 8b away from the fixed mold 8a.

  Here, referring to FIG. 1 again, a method of manufacturing the housing 100 will be described. In the molding step (S8), the casing 100 is manufactured by injection molding by the injection molding machine 1 shown in FIG.

  As described above, the casing 100 is formed from a kneaded product of a polylactic acid resin and a lignocellulosic material in which a lignocellulosic modifier is generated. As a result, the casing 100 is biodegraded into water and carbon dioxide by natural microorganisms and degrading enzymes, that is, harmlessly returns to the soil, so that the load on the environment can be reduced.

  Furthermore, since the casing 100 does not generate harmful gas such as dioxin at the time of incineration, air pollution can be prevented and the load on the environment can be reduced.

  In addition, since a polylactic acid resin, which is a non-petroleum resource, is used, the use of fossil fuel is not required, and fossil fuel depletion can be prevented.

  Moreover, the housing | casing 100 mutually adhere | attaches by the self-adhesive property which a hemicellulose type | system | group decomposition component has. Thereby, the housing | casing 100 can ensure intensity | strength compared with the housing | casing shape | molded by mix | blending lignocellulosic material with resin.

  In the present embodiment, the polylactic acid resin is kneaded in order to improve the fluidity of the lignocellulosic material from which the lignocellulosic modifier is generated, but is not necessarily limited thereto. Other biodegradable resins, for example, microbial biodegradable resins, chemically synthesized biodegradable resins, and natural product biodegradable resins may be mixed.

  Here, poly-3-hydroxybutyric acid (PHB), polyhydroxyalkanoate (PHA), or the like can be used as the microbial biodegradable resin. In addition, as a chemically synthetic biodegradable resin, polyvinyl alcohol (PVA), polyglycolic acid (PGA), or the like can be used. Further, as a natural product-based biodegradable resin, starch polyester, cellulose acetate and the like can be used.

  However, it is preferable to knead a chemically synthesized biodegradable resin that is a general-purpose resin, specifically, an aliphatic and aromatic polyester. Since these aliphatic and aromatic polyesters are in widespread use, the cost is lower than that of microbial biodegradable resins and natural product biodegradable resins. This is because the cost can be reduced.

  It is also desirable to knead petroleum-based aliphatic and aromatic polyesters. A casing formed by kneading such petroleum-based aliphatic and aromatic polyesters can ensure strength as compared with a casing formed by kneading a plant polylactic acid resin.

  Here, as the petroleum-based aliphatic polyester, polybutylene succinate (PBS), polycaprolactone (PCL), or the like can be used. As the petroleum-based aromatic polyester, polybutylene adipate terephthalate (PBAT), polyethylene terephthalate succinate (CPE), or the like can be used.

  In the kneading step (S5), when the lignocellulosic material from which the lignocellulosic modifier is produced and the biodegradable resin such as polylactic acid resin or polyester biodegradable resin are kneaded, In order to improve fluidity, it is preferable to add a lubricant.

  For example, a composition used as an injection in an injection molding machine includes (A) a lignocellulosic material in which a lignocellulosic modifier is generated, and (B) an aliphatic or aromatic polyester biodegradable resin ( Aliphatic or aromatic polyester-based biodegradable resin) and (C) an oligomeric lubricant, the composition of each component is 40 to 100 parts by weight and 0 parts by weight, respectively. It is preferably 1 to 10 parts by weight with respect to 60 parts by weight or more and 100 parts by weight of the mixture of component (A) and component (B).

  The composition containing component (A) to component (C) in the above composition comprises (B) a lignocellulosic material in which (A) a lignocellulosic modifier is produced by addition of an oligomeric lubricant (B) Dispersibility of the polyester biodegradable resin can be improved. In addition, by setting the ratio of (C) oligomer-based lubricant to 1 to 10 weights with respect to 100 parts by weight of the mixture of component (A) and component (B), (C) by adding oligomer-based lubricant Stickiness can be suppressed. As a result, the fluidity of the composition containing the lignocellulosic material in which the lignocellulosic modifier is produced is improved, and sufficient fluidity to flow out from the nozzle of the injection molding machine can be obtained. is there.

  A lubricant further added to the composition in that the composition containing the lignocellulosic material and the biodegradable resin in which the lignocellulosic modifier is produced is used as an injection in an injection molding machine. It is necessary to have heat resistance that can correspond to the molding temperature of the lignocellulosic material or biodegradable resin from which the lignocellulosic modifier is produced. For this reason, as a preferable lubricant, for example, a narrow distribution EXELEX (registered trademark) (manufactured by Mitsui Chemicals, Inc.) which is an oligomeric low molecular weight polyethylene (metallocene based oligomeric low molecular weight polyethylene) produced by using a metallocene catalyst Can be preferably used. The molecular weight of the lubricant is preferably about 1000 to 5000.

  The polylactic acid-based resin may be decomposed by an acid such as acetic acid that is generated when wood is steam-treated in the steam treatment step (S2). On the other hand, petroleum-based aliphatic and aromatic polyesters are stable against acids such as acetic acid, and thus improve the fluidity of the lignocellulosic material in which the lignocellulosic modifier is produced. be able to.

  Next, the fluidity test will be described with reference to FIGS. The fluidity test is a test for measuring the fluidity of the lignocellulosic material, and was performed using a flow tester shown in FIG.

  The flow tester includes a cylindrical cylinder portion and a piston portion that is fitted in the cylinder portion and can reciprocate in the cylinder portion, and a nozzle is formed in the side wall portion of the cylinder portion.

  In the flow test, as shown in FIG. 6, a sample (lignocellulosic material) is filled in the cylinder part, and the piston part is pressurized and pushed, and it is necessary for the sample to flow out from the cylinder through the nozzle. Measure the applied pressure.

  As shown in FIG. 7, the applied pressure includes a “flow start” pressure (pressure when the pressure is gradually increased and the sample starts to flow out of the nozzle) and a “flow stop” pressure (pressure is increased to the flow start pressure). After that, the pressure was gradually decreased and the pressure when the flow of the sample stopped was measured.

  The flow test is performed in a state where the flow tester is heated to 180 ° C., the inner diameter of the cylinder part is set to a diameter of 60 mm, and the shape of the nozzle is set to a rectangular shape of 2.8 mm × 3.8 mm. The weight is 20 g.

  For the sample, the lignocellulosic resin composition described in the above embodiment was compared with the sample 1 in which the particle size of the lignocellulosic material was set in the range of 250 μm to 500 μm, and the particle size of the lignocellulosic material from 50 μm. Sample 2 set within a range of 250 μm, Sample 3 to which 2% by weight of Exelex 48070B (registered trademark) (manufactured by Mitsui Chemicals), which is a metallocene oligomeric low molecular weight polyethylene as a lubricant, was added, and the above as a lubricant Sample 4 to which 5% by weight of Excelx 48070B (registered trademark) (manufactured by Mitsui Chemicals, Inc.) was added, and sample 5 to which 10% by weight of the above Excell 48070B (registered trademark) (manufactured by Mitsui Chemicals, Inc.) was added as a lubricant Sample 6 to which 5% by weight of zinc stearate was added as a lubricant, and TOWAX-131 (registered trademark) (as a lubricant) Sub Kasei Co., Ltd.) 2% by weight of the sample 7 was added, and was used TOWAX-131 (registered trademark) (Toa Kasei Co., Ltd.) Sample 8 was added 5% by weight as a lubricant.

  As shown in FIG. 7, when Sample 1 and Sample 2 are compared, it is recognized that there is an effect of reducing the pressure at the start of flow by reducing the particle size of the lignocellulosic material. There is no change in the flow stop pressure.

  When samples 3 to 5 are compared, it is recognized that there is an effect of reducing the pressure at the start of flow by increasing the amount of lubricant added. The flow stop pressure does not change when added at 5 wt% or more.

  From the results of Samples 6 to 8, it is recognized that adding the above-described zinc stearate or the like as a lubricant also has an effect of improving fluidity. In the case of Sample 7 and Sample 8, there is no change in fluidity even when the addition amount is increased.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in the above-described embodiment, the casing 100 is made of a lignocellulosic material and a biodegradable resin, but is not necessarily limited thereto, and includes, for example, a thermoplastic resin such as polyethylene or polypropylene. You may let them.

  Moreover, in the said embodiment, although the cylinder 5 is comprised by the in-line screw type which fuse | melts material by rotation of a built-in screw, it is not necessarily restricted to this, For example, it pushes in with a built-in plunger. You may comprise by the plunger type which injects.

  Moreover, although the said embodiment demonstrated the case where the plasticization injection mechanism of the injection molding machine 1 was comprised with an in-line screw type, it is not necessarily restricted to this, A plasticization injection mechanism is various other well-known. Of course, it is possible to configure with this mechanism.

  Similarly, the case where the mold clamping mechanism of the injection molding machine 1 is configured by a horizontal type and a direct pressure type has been described, but the present invention is not necessarily limited thereto, and the mold clamping mechanism may be configured by various other known mechanisms. Is of course possible.

  As another plasticizing injection mechanism, for example, a pre-plastic type is exemplified. Thereby, in each process of FIG. 1, while being able to abbreviate | omit a pellet shaping | molding process (S6), from the kneading | mixing process (S5) to a shaping | molding process (S7) can be performed with the 1 injection molding machine 1, The manufacturing cost can be reduced.

  Moreover, in the said embodiment, although the housing | casing 100 is formed with the lignocellulose type injection molded object, it is not necessarily restricted to this shape, The product and components of another shape are made with a lignocellulose type injection molded object. It may be formed.

  Further, the size of the housing 100 in the above embodiment is an example, and is not necessarily limited to this size.

It is process drawing of the manufacturing method of the housing | casing of this invention. It is a front view which shows an injection molding machine typically. It is a perspective view of a housing | casing. 2 is a photograph of an injection molded housing and an Izod impact test piece. It is a figure which shows the physical-property value of a housing | casing. It is a photograph of a flow tester. It is a graph which shows the result of a fluidity test.

Explanation of symbols

100 Housing S1 Grinding step S2 Steam treatment step S4 Fine grinding step S5 Kneading step (mixing step)
S7 Degassing process S8 Molding process

Claims (6)

A pulverization step of pulverizing a lignocellulosic material containing at least hemicellulose, lignin and cellulose; and a steam treatment step of generating a lignocellulosic modifier by steaming the lignocellulosic material pulverized in the pulverization step; A lignocellulosic resin composition comprising: a molding step of molding the lignocellulosic material in which the lignocellulosic modifier has been produced in the steam treatment step with an adhesive force of the lignocellulose modifier. In the casing injection molding method,
A mixing step of mixing a biodegradable resin and a lubricant into the lignocellulosic material in which the lignocellulosic modifier is generated in the steaming step after the steaming step and before the molding step. With
In the mixing step, the ratio of the biodegradable resin and the lubricant is 1% by weight or more based on the total weight of the mixture of the biodegradable resin and the lignocellulosic material from which the lignocellulosic modifier is generated. Are mixed in
The molding step is an injection molding of a mixture of the biodegradable resin and lubricant mixed in the mixing step and the lignocellulosic material in which the lignocellulosic modifier is generated. A casing injection molding method for lignocellulosic resin composition.   After the mixing step and before the molding step, a deaeration step for removing moisture or pyrolysis gas contained in the lignocellulosic material from which the lignocellulosic modifier is generated is provided. The method for injection molding a lignocellulosic resin composition according to claim 1.   A pulverization step of pulverizing the lignocellulosic material from which the lignocellulosic modifier is produced is provided after the steam treatment step and before the mixing step. Item 3. A casing injection molding method of a lignocellulosic resin composition according to Item 1 or 2.   4. The casing injection molding method for a lignocellulosic resin composition according to any one of claims 1 to 3, wherein the biodegradable resin is composed of a polyester resin.   The said biodegradable resin is comprised with the polylactic acid-type resin, The housing | casing injection molding method of the lignocellulose-type resin composition of Claim 4 characterized by the above-mentioned. A lignocellulosic resin composition comprising the lignocellulosic material in which a lignocellulosic modifier is produced by pulverizing a lignocellulosic material containing at least hemicellulose, lignin and cellulose and performing a steam treatment,
40 to 100 parts by weight of (A) the lignocellulosic material in which the lignocellulosic modifier is produced;
(B) polyester-based biodegradable resin in an amount of more than 0 parts by weight and not more than 60 parts by weight;
A lignocellulosic resin composition comprising 1 to 10 parts by weight of (C) oligomer-based lubricant with respect to 100 parts by weight of the mixture of (A) and (B).