JP2008274200A - Method for producing cellulose fiber-reinforced composite, cellulose fiber-reinforced composite and material for producing cellulose fiber-reinforced composite - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cellulose fiber-reinforced composite in which fibrillated cellulose fibers are dispersed in a polymer compound, by synthesizing raw materials while the fibrillated cellulose fibers are held to be dispersed in the raw material, in the method for producing the cellulose fiber-reinforced composite. <P>SOLUTION: This method comprises a grinding step of disintegrating cellulose fibers by passing a pulp dispersed in a liquid polyhydric alcohol being a precursor of a polymer compound into a grinder, and a step of subjecting the pulp to a reaction with a compound having a plurality of functional groups forming chemical bonding to hydroxy groups of the polyhydric alcohols, to synthesize the polymer compound, followed by molding it. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for producing a cellulose fiber reinforced composite reinforced with cellulose fibers, a cellulose fiber reinforced composite reinforced with cellulose fibers, and a material for producing a cellulose fiber reinforced composite suitable for the production thereof. .

For a long time, it has been practiced to produce molded products by adding wood powder or wood pulp to thermosetting resins. However, waste problems such as plastics have become serious nowadays. Degradable plastics have been developed. For example, Patent Document 1 describes that a high-strength composite material is provided by impregnating microfibrillated cellulose with a thermosetting resin or a thermoplastic resin.
However, in the manufacturing method in which a fiber aggregate of cellulose fibers is impregnated with a resin, processing is difficult and mass productivity is poor. In particular, Functional Paper Research Group No. 24, 5-12, 1985 and JP-A-10-248872, from the state of being dispersed in moisture in order to maintain the form of microfibrillated cellulose fibers having a diameter of 0.1 μm or less. When trying to mold while drying, the water retention is high, and in order to make a molded body, a large amount of water must be evaporated and dried, and the volume is large, for example, 1/2 to 1/5. It is necessary to overcome the distortion associated with shrinkage.

Further, Patent Document 2 discloses a technique for dissolving microfibril cellulose in a resin by melting cellulose fibers while kneading with a kneader, for example, a kneader.
However, this method also requires molding while melting the resin at a high temperature, requires a high temperature and a high pressure, and is difficult to mold into a complicated shape due to the high melt viscosity of the molten resin containing fibers.
JP 2003-201695 A JP 2005-42283 A

An object of this invention is to provide the simple manufacturing method which improved the moldability of the cellulose fiber reinforced composite shape | molded by arrange | positioning the cellulose fiber containing a diameter-reduced cellulose in a high molecular compound.
Another object of the present invention is to provide a cellulose fiber reinforced composite having a high affinity between the cellulose fiber and the polymer compound by changing the medium itself having a high affinity with the reduced-diameter cellulose into a polymer compound.
Moreover, it aims at providing the material suitable for manufacture of a cellulose fiber reinforced composite.
In this specification, a cellulose fiber having a fiber diameter in the range of 10 nm to 400 nm is defined as a thinned cellulose fiber. In the claims, the extension needs to be clarified, but the above definition is a special definition used only in this specification because the claims may be ambiguous. In order to obtain cellulose fibers having a fiber diameter of 400 nm or less, it is necessary to add some artificial treatment since the fiber diameter of paper or pulp is usually on the order of μm. Here, the fiber diameter can be measured, for example, with a scanning microscope.

  The method for producing a cellulose fiber reinforced composite according to the first invention is a liquid polyhydric alcohol or a liquid and a plurality of hydroxyl groups containing cellulose fibers having a fiber diameter in the range of 10 nm to 400 nm (hereinafter referred to as thinned cellulose fibers). A first step of preparing a polyhydric alcohol derivative (hereinafter referred to as a liquid polyhydric alcohol by combining the polyhydric alcohol and the derivative) having a plurality of functional groups that chemically bond with a hydroxyl group of the liquid polyhydric alcohol And a second step of forming a polymer compound by reacting with a compound.

The method for producing a cellulose fiber reinforced composite according to the second invention is the method for producing a cellulose fiber reinforced composite according to the first invention, wherein the first step is to use paper or pulp as a raw material and the fiber diameter of the cellulose fiber. In the liquid polyhydric alcohols, a physical force is applied to the raw material in the liquid polyhydric alcohols so that there are those that fall within the range of 10 nm to 400 nm. Including the step of preparing.

The method for producing a cellulose fiber reinforced composite according to the third invention is the method for producing a cellulose fiber reinforced composite according to the first invention, wherein the first step is to use a fiber of cellulose fiber using paper or pulp as a raw material. By crushing the raw material with liquid polyhydric alcohols having a boiling point or decomposition temperature higher than the boiling point of water and water so that there are those whose diameters fall within the range of 10 nm to 400 nm, the diameter-reduced cellulose Including a step of preparing a liquid polyhydric alcohol containing fibers and water, and a step of evaporating water to reduce the water by bringing the diameter-reduced cellulose, water and polyhydric alcohol to a temperature equal to or higher than the boiling point of water. .
In this specification and claims, having a boiling point or decomposition temperature higher than that of water means that if it has a boiling point, the boiling point should be higher than the boiling point of water, and if it has no boiling point, it will decompose. It means that the temperature should be higher than the boiling point of water.

The method for producing a cellulose fiber reinforced composite according to the fourth invention is the method for producing a cellulose fiber reinforced composite according to the first invention. A first pretreatment step in which cellulose fibers are unwound by applying a physical force to the raw material in water so that there are those in the range of 10 nm to 400 nm, and cellulose containing water produced in the first pretreatment step A second pretreatment step in the assembly of fibers, in which a liquid polyhydric alcohol having a boiling point higher than the boiling point of water or a decomposition temperature is added or at least a part of water is substituted with the liquid polyhydric alcohol;
Is included.

  The cellulose fiber reinforced composite according to the fifth invention is manufactured by the method for manufacturing a cellulose fiber reinforced composite according to any one of the first to fourth inventions.

  A cellulose fiber reinforced composite according to a sixth invention is characterized in that, in the cellulose fiber reinforced composite of the fifth invention, the polymer compound has bubbles.

  A material for producing a cellulose fiber reinforced composite according to a seventh aspect of the present invention is a material for producing a cellulose fiber reinforced composite for producing a cellulose fiber reinforced composite in which a reduced-diameter cellulose fiber is dispersed in a polymer compound. , Liquid polyhydric alcohols, and a cellulose fiber aggregate including a cellulose fiber having a reduced diameter.

  According to the method for producing a cellulose fiber reinforced composite according to the first invention, the liquid polyhydric alcohol containing the thinned cellulose fiber is a liquid and a synthetic raw material for the polymer compound. Can be freely defined in form or can be continuously produced.

  According to the method for producing a cellulose fiber reinforced composite according to the second aspect of the invention, since the cellulose fiber is unwound together with paper and pulp using polyhydric alcohols as a medium, the concentration of polyhydric alcohols is high, and the chemical bonds with hydroxyl groups Thus, there is an effect that a chemical reaction with a compound having a plurality of functional groups can be easily performed and a stable moldability can be obtained.

  According to the method for producing a cellulose fiber reinforced composite according to the third or fourth aspect of the invention, since cellulose fibers are unwound using polyhydric alcohols and water together with paper and pulp, the polyhydric alcohols and water The ratio can be adjusted, and there is an advantage that inexpensive water can be used as a part of the medium when water is used for the reaction or when water is not an obstacle to the reaction.

  According to the cellulose fiber reinforced composite according to the fifth invention, since the polyhydric alcohol has a hydroxyl group, the affinity between the cellulose fiber and the polymer compound is high, and the cellulose fiber reinforced composite that can sufficiently draw out the reinforcement by the cellulose fiber is obtained. There is an effect that can be obtained.

  According to the cellulose fiber reinforced composite according to the sixth aspect of the invention, there is an effect that the density of the cellulose fiber and the polymer compound is high and the density can be adjusted by voids due to bubbles.

  According to the material for producing a cellulose fiber reinforced composite according to the seventh invention, since the polyhydric alcohol and the cellulose fiber aggregate are mixed and the amount of water is small, in order to form a polymer compound in which cellulose fibers are dispersed. It is suitable for reacting a compound having a plurality of functional groups chemically bonded to hydroxyl groups of liquid polyhydric alcohols.

  Below, the manufacturing method of the cellulose fiber reinforced composite of this invention and the cellulose fiber reinforced composite by it are demonstrated.

  Cellulose fibers are materials that improve the strength of composite materials. When the fiber diameter of the cellulose fiber is large, the proximity point between the fibers is reduced. If the fiber diameter is too large, the number of adjacent points decreases, and the tensile strength of the cellulose fibers cannot be sufficiently reflected in the strength of the composite material. Therefore, it is preferable to increase the number of adjacent points by thinly breaking the cellulose fiber. The lower limit of the diameter of the cellulose fiber is 10 nm because the single diameter of bacterial cellulose is about 4 nm. However, this does not mean that cellulose fibers below the lower limit should not be included.

  On the other hand, the upper limit of the cellulose fiber is also an indication of the degree to which the cellulose fiber is reduced in diameter, and it is preferable that the cellulose fiber is unraveled to such an extent that a thin fiber of 400 nm or less is seen, and the diameter of 400 nm or more. It does not mean that cellulose fibers should not be included.

  In addition, it is not limited about the length of a cellulose fiber, It is difficult to limit. In the present invention, cellulose fibers such as paper or pulp that are used in a state that does not reach a so-called microfibrillation treatment described in, for example, JP-A-2007-51266 are disclosed in JP-A-2007- It is considered that the first step is to solve the state called microfibrillation or the state just before that by a technique similar to that described in Japanese Patent No. 51266. The fiber length is not specified because it is not completely separated one by one. Even in this state, it can be sufficiently present in the polymer compound as a reinforcing fiber.

First, a cellulose having a reduced diameter is prepared using paper or pulp as a starting material. Pulp here refers to chemical pulp obtained by chemical treatment from wood, such as kraft pulp, sulfite pulp, semi-chemical pulp that has been pulped by mechanical treatment such as refiner and grinder, and recycled from used paper Pulp is exemplified.
For example, as described in JP-A-2005-42283, paper or pulp is preferably subjected to a known refiner treatment as a pretreatment. However, refiner processing is not necessarily required. It is because it can respond by design matters, such as increasing the frequency of passage of the grinding machine in the grinding process.

(First embodiment)
Hereinafter, the manufacturing method of the cellulose fiber reinforced composite by 1st Embodiment of this invention is demonstrated using FIG.
First, pulp is prepared. Although pulp is used here as a raw material, it is not limited to pulp, and may be paper, for example, used paper such as newspaper or milk cartons. That is, any material mainly composed of cellulose fibers obtained by removing lignin from wood or the like may be used, and the material is not limited to what is called pulp or paper. However, pulp and paper are suitable in view of the fact that the material can be supplied stably and the stability of the material, that is, the material is hardly deteriorated and is easily stored.

Next, in the defibrating step K11, the prepared pulp is defibrated by a defibrator. For example, using a dry-type defibrator such as a trade name “Atoms” manufactured by Hyakuma Yamamoto Co., Ltd. or a first defibrator described in Japanese Patent Application Laid-Open No. 8-215595, in which a swing cutter rotates at an ultra-high speed. Defibration. In a wet defibrating machine such as a refiner, a large amount of water is contained, which is not preferable.
For example, the first defibrator described in JP-A-8-215595, that is, a fixed drum, a rotary blade provided in the fixed drum and defibrated in cooperation with the blade of the fixed drum, and the fixed drum If a gas suction part that generates an air flow and a screen for discharging the defibrated material are used, the entanglement between cellulose fibers of the pulp can be unwound in a dry manner. That is, an aggregate of cellulose fibers in the form of cotton can be obtained. Making the cellulose fiber cottony is preferable because the length of the cellulose fiber is not too short. However, since there are various specifications required for the cellulose fiber reinforced composite, if the desired aspect ratio is obtained when the fiber diameter is reduced through the grinding process described later, the powder is removed in the defibrating process K11. You may make it.
The defibration described in JP-A-8-215595 further includes a step of defibrating pulp containing water by a second defibrator, but a casting / synthesis step described later with a small amount of water to be included. As long as it does not interfere with the synthesis at K16, the defibrating step by the second defibrator does not have to be omitted when utilizing the defibration described in JP-A-8-215595. If it is not desired to include moisture, the process of adding moisture may be omitted and the process performed by the first defibrator may be used.

Next, a mixing step K12 for mixing polyhydric alcohols with the defibrated pulp is performed. Mixing is performed, for example, by putting the defibrated pulp into polyhydric alcohols in a container and stirring it at the same time as deaeration while moving the sealed container in a planetary motion. As such a stirring / defoaming apparatus, for example, there is a “mixing apparatus for fluid substances” described in JP-A-6-205956. In addition, there is a trade name “Mazerustar” which is a stirring and defoaming device manufactured by Kurashiki Boseki Co., Ltd.
If the process is performed more easily without using a special device, the defibrated pulp may be simply immersed in a container containing polyhydric alcohols. Moreover, when producing in large quantities, it is preferable to mix continuously. In any mixing method, since many polyhydric alcohols have a flash point, mixing in a dry nitrogen atmosphere is preferable. Further, in order to familiarize the polyhydric alcohols and the pulp, after stirring and defoaming, for example, it is stored in a dry nitrogen atmosphere at room temperature for 24 hours.

Next, the process proceeds to the grinding step K13. In the grinding process K13, as a grinding machine, for example, a grinding machine as described in Japanese Patent Application Laid-Open No. 2007-1000024, for example, a product name “Supermass colloider” manufactured by Masuko Sangyo Co., Ltd. The product name “Pure Fine Mill” manufactured by Kurita Machine Works, Ltd. is used.
FIG. 2 schematically shows a cross section of the main part of the attritor. The grinding machine of FIG. 2 includes a pair of disc-shaped abrasive plates 1 and 2 facing each other, a supply pipe 3 for supplying a mixture of pulp and polyhydric alcohol between the abrasive plates 1 and 2, A drive motor 4 for rotating the lower abrasive grain plate 2 and a drive shaft 5 for transmitting a driving force from the drive motor 4 to the lower abrasive grain plate 2 are provided. As shown in FIG. 2, the abrasive grain plates 1 and 2 have a recess that forms a grinding chamber 6 in which the material to be ground is retained in the vicinity of the center of rotation of the opposing portion. Further, the grinding chamber 6 is provided with a feeding rotary blade 8 for adjusting the flow of the mixture and stably feeding the mixture into the grinding space 7 formed on the opposing surfaces of the abrasive grain plates 1 and 2. ing.
In Japanese Patent Application Laid-Open Publication No. 2007-1000024, the process of tearing cellulose fibers into fine pieces is performed by dispersing the defibrated pulp in a large amount of moisture. However, a large amount of polyhydric alcohols is used here. Since many polyhydric alcohols have a flash point, it is preferable to perform the grinding step K13 in a nitrogen atmosphere.
The polyhydric alcohol used here has a very high viscosity as compared with the viscosity of water conventionally used for breaking cellulose fibers, and reaches several tens to several thousand times. Therefore, it is supplied to the attritor through the supply pipe 3 while being pressurized with a pump. When the polyhydric alcohol has a hydroxyl group and the viscosity increases, the efficiency of unraveling the cellulose fibers can be increased. A well-known pump can be used as the fluid pump that supplies the mixture of pulp and polyhydric alcohol while applying pressure.
It can be seen from the description of JP-A-2007-1000024 that it is not sufficient to unravel cellulose fibers once through a grinder. The number of passes is appropriately designed based on differences in the grain size of the abrasive grains, differences in the spacing and rotational speed of the abrasive grains, differences in the affinity between water and cellulose fibers of polyhydric alcohols, and differences in the viscosity of the liquid. The
In the grinding process K13, for example, a plurality of grinders are arranged so that the grain size of the abrasive plate is gradually fined and the interval is gradually narrowed, and the grinders are sequentially passed through the plurality of grinders. May be produced continuously. Moreover, you may use the high-pressure homogenizer used conventionally in order to unwind a cellulose fiber.
In grinding process K13, what passes through a grinding machine many times and the thing in which the fiber diameter of a cellulose fiber becomes 10 nm-400 nm is contained.

Through the polishing step K13, when polyhydric alcohols containing finely divided cellulose fibers are obtained, a chemical reaction with the polyhydric alcohols occurs to form a polymer compound. Mixing with a compound having a functional group that causes a reaction.
In the 2nd mixing process K14, it mixes so that it can synthesize | combine by the casting / synthesis process K15 mentioned later. If the synthesis is started by mixing, a casting / synthesis process K16 and a mixing process 15 described later may be performed simultaneously.
For example, when a thin cellulose fiber is produced using diethylene glycol as a polyhydric alcohol, when producing a rigid polyisocyanurate foam using the diethylene glycol, for example, 8 weights per 100 parts by weight of polymeric diphenylmethane diisocyanate. Part of diethylene glycol is added. Further, 21 parts by weight of chlorofluorocarbon, 1 part by weight of a silicone foam stabilizer, and 5 parts by weight of a polyoxyethylene glycol solution of potassium amine octylate having a molecular weight of 200 are added as a catalyst. Note that the weight of cellulose fibers is not included in 8 parts by weight of diethylene glycol. For example, in the grinding step K13, if the weight ratio of cellulose fibers including diethylene glycol and thinned cellulose fibers is obtained at a ratio of 4 to 1, the weight of the cellulose fibers is 2 parts by weight. Addition of the mixture obtained in the crushing step K13 is a total of 10 parts by weight.
In the above example, when the isocyanate is 15 ° C. and the polyol is 20 ° C., the mixing time is 10 seconds, the cream time is 19 seconds, the gel time is 33 seconds, and the rise time is 42 seconds.

The rotation speed is rapidly increased from 0 to 1500 rpm or more from a state where the stirring blade is sufficiently immersed in the liquid. The stirring by the stirring blade is quickly performed within the mixing time.
Next, after stirring within the mixing time, it is quickly poured into the mold. After the rise time elapses from the cream time, it is aged in a heating furnace and then removed (casting / synthesis step K15).
A necessary part is cut out by cutting the cellulose fiber reinforced composite taken out or the like to complete a molded body of the cellulose fiber reinforced composite (finishing step).
When foaming is performed in the reaction between the isocyanate and the polyol exemplified as described above, bubbles are formed in the molded body, so that the density can be adjusted.
As another example, in the mixing step K14, first, a polyol including finely divided cellulose fibers can be obtained by using ethylene glycol, propylene glycol, glycerin or the like as a polyhydric alcohol as an initiator. In addition, polyhydric alcohols in which fine cellulose fibers are dispersed can also be used as a synthetic raw material for polyester.
Thus, in the mixing step K14, synthesis as a pretreatment for reacting with a compound may be performed in the casting / synthesis step K15 in the subsequent step.
A liquid A is prepared by adding a catalyst such as an amine catalyst to the obtained polyol, a foaming agent, a foaming agent, a crosslinking agent as required, and additives such as a mold release agent, a pigment, and a flame retardant as necessary . On the other hand, an isocyanate such as toluene diisocyanate is prepared as the B liquid. And B liquid is added to A liquid and it mixes quickly. Moreover, the polyol which is a derivative | guide_body of a polyhydric alcohol can also be produced | generated through a grinding process using the polyol containing fine diameter cellulose as a polyhydric alcohol.
In the next casting / synthesizing step K15, in addition to pouring into the mold, the mixed liquid A and liquid B may be flowed onto the belt conveyor to be formed into a plate shape. Alternatively, it can be sprayed onto a building wall and synthesized on the wall.
When formed into a plate shape, a finishing process K16 is performed in which the board is cut into a predetermined size or unnecessary ear portions are cut. Moreover, it is also a concept included in the casting / synthesizing step K15 in the present invention to form by spraying on the wall. In the case of spraying on a wall or the like, the finishing process K16 is a process of forming another material on the wall or covering it with an iron or wooden board for use as a heat insulating material.
For example, the liquid A includes 100 parts by weight of scroll-type polyether polyol, OHV450, 15 parts by weight of trichloroethyl phosphate (flame retardant), 1.5 parts by weight of dimethylcyclohexylamine (catalyst), and 1 part of silicone foam stabilizer. 0.5 parts by weight, 0.5 parts by weight of water, 30 parts by weight of Freon 11 and 128 parts by weight of polymeric MDI (diphenylmethane diisocyanate) are used as the liquid B. The polyether polyol contains 1 part by weight of reduced-diameter cellulose. The mixing time at this time is about 10 seconds.

As explained above, polyhydric alcohols include polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin. A mixture of these may also be used.
Further, the polyhydric alcohols include polyols formed by synthesizing polyhydric alcohols. Some polyols are liquid and have a boiling point higher than that of water.
Polyhydric alcohols include liquid compounds that can be synthesized with compounds derived from polyhydric alcohols and mixed in mixing step K14. The reason why it is necessary to be in a liquid state is to put pulp in the liquid in order to grind the cellulose fibers in the grinding step K13. Therefore, when it is necessary to adjust the viscosity, other viscosity modifiers may be added.

(Second Embodiment)
Next, the manufacturing method of the cellulose fiber reinforced composite by 2nd Embodiment of this invention is demonstrated using FIG.
First, pulp is prepared. In the defibrating step K21, the pulp prepared in the same manner as in the defibrating step K11 described above is defibrated by a defibrating machine.

  Next, a mixing step K22 for mixing polyhydric alcohols and water with the defibrated pulp is performed. The mixing is performed, for example, by stirring at the same time as deaeration while moving the sealed container in a planetary motion, similarly to the above-described mixing step K12. The weight ratio of the polyhydric alcohols, water and pulp to be put in the container is appropriately selected. For example, as a polyhydric alcohol, polypropylene glycol (hereinafter referred to as PPG) is added at a ratio of 100 parts by weight of water and 1 part by weight of pulp with respect to 100 parts by weight.

Next, the process proceeds to the grinding step K23. In the grinding process K23, a grinding machine similar to the grinding process K13 described above is used, and a mixture of a large amount of polyhydric alcohols and water is used. Many polyhydric alcohols have a flash point, but because they are mixed with water, they are less flammable than when only polyhydric alcohols are used alone, but in a nitrogen atmosphere or carbon dioxide atmosphere It is preferable to perform the grinding step K23.
The number of passes through the grinder, that is, the number of disintegrations with the grinder, is the difference in the grain size of the abrasive grains, the spacing between the abrasive grains and the number of rotations, or the affinity of the mixture of water and polyhydric alcohols with the cellulose fibers. It is designed as appropriate based on differences in liquidity and liquid viscosity. For example, a mixture consisting of 100 parts by weight of PPG, 100 parts by weight of water and 1 part by weight of pulp is passed through a grinder about 10 to 20 times.

After the grinding step K23, a mixture of water and polyhydric alcohols containing finely divided cellulose fibers is obtained. Next, in the water reducing step K24a, the polyhydric alcohols, water and finely divided cellulose fibers are mixed. Remove or reduce water from the containing mixture.
First, the ratio of liquid to solid is adjusted to reduce water. In the grinding process K23, since it is necessary to extrude a cellulose fiber with a liquid from the clearance gap between an abrasive grain board and an abrasive grain board, a lot of liquid is required, for example. However, in the casting / synthesizing step K25 described later, the ratio of the polyhydric alcohols that are the raw materials of the matrix of the cellulose fiber-reinforced composite and the cellulose fibers that are the reinforcing fiber component is It is necessary to set the components in accordance with a desired ratio. In the preceding water reduction step K24a, the liquid component consisting of polyhydric alcohols and water is filtered by a screen or the like to reduce the liquid component and to be described later. Easy to adjust according to the mold / synthesis process K25. At the same time, since the heat capacity of the mixture is reduced by reducing the liquid component, there is an effect of lowering the energy required for reducing the moisture in the liquid component. For example, the mixture of 100 parts by weight of PPG, 100 parts by weight of water, and 1 part by weight of cellulose fibers obtained in the grinding step K23 is filtered through a screen, and 10 parts by weight of cellulose fiber content is added to 100 parts by weight of the mixed liquid of PPG and water. Raise to weight part.

  Next, for example, dehydration under reduced pressure is performed to reduce the ratio of water in the mixed liquid pair of PPG and water. For example, when PPG is selected as the polyhydric alcohol, the moisture content is reduced to about 3 parts by weight with respect to 100 parts by weight of PPG by keeping it at 130 ° C. in a reduced dry nitrogen atmosphere. After cooling, water to which an amine catalyst is added is added to adjust the water content to 5 parts by weight with respect to 100 parts by weight of PPG. Although the boiling point of polyhydric alcohols is reduced by decompression, the boiling point of water is also lowered. Therefore, water can be reduced if the polyhydric alcohols have a boiling point relatively higher than that of water.

  In order to form a polymer compound by causing a chemical reaction with a polyhydric alcohol, mixing with a compound having a functional group that causes a chemical reaction with a hydroxyl group of the polyhydric alcohol is performed. For example, 100 parts of PPG, 5 parts by weight of water, 10 parts by weight of cellulose fibers, and 57 parts by weight of tolylene diisocyanate are mixed. For example, mixing is performed quickly within a mixing time with a 4000 rpm stirrer.

Next, after stirring within the mixing time, it is quickly poured into the mold. After elapse of the rise time from the cream time, it is aged in a heating furnace and taken out (casting / synthesis step K25). For example, when 100 parts by weight of PPG, 5 parts by weight of water, 10 parts by weight of cellulose fibers, and 57 parts by weight of tolylene diisocyanate are mixed and cast, the mold is placed in a constant temperature bath at 100 ° C. and demolded after 1 hour.
A necessary part is cut out of the taken-out cellulose fiber reinforced composite by cutting or the like to complete a molded body of the cellulose fiber reinforced composite (finishing step K26).
In the description of the second embodiment, PPG derived from polyhydric alcohol has been described as an example, but it goes without saying that polyhydric alcohol may be used as in the first embodiment. Absent. Whether to obtain a finely divided cellulose fiber using a polyhydric alcohol or to obtain a thinned cellulose fiber using a derivative from a polyhydric alcohol depends on what kind of polymer compound is desired, Any liquid polyhydric alcohol having a boiling point or decomposition temperature exceeding the boiling point of water is applicable in the second embodiment.

(Third embodiment)
Next, the manufacturing method of the cellulose fiber reinforced composite by 3rd Embodiment of this invention is demonstrated using FIG.
First, pulp is prepared. In the defibrating step K31, the pulp prepared in the same manner as in the defibrating step K11 described above is defibrated by a defibrating machine.

  Next, a mixing step K32 for mixing water with the defibrated pulp is performed. For example, as in the mixing step K12 described above, mixing can be performed simultaneously with deaeration while moving the sealed container in a planetary motion, but it is easier to perform mixing by wing stirring or the like in the tank. When water is used as a pulp dispersion medium, the viscosity is lower than that of polyhydric alcohols, so there is little entrainment of air or the like, and there is little difference in the efficiency of unraveling cellulose fibers even if the defoaming step is omitted. For example, with respect to 100 weight part of water, it mixes in the ratio of 1.5-6 weight part of pulp. In the mixing step K32, the pulp is stored at room temperature and normal pressure, for example, for 24 hours in order to adjust the pulp to water.

  Next, the process proceeds to the grinding step K33. In the grinding step K33, a grinding machine similar to the grinding step K13 described above is used, and a mixture with a large amount of water is used. For example, a mixture of 1.5 to 6 parts by weight of pulp and 100 parts by weight of water is used. The number of times of passing through the grinder, that is, the number of times of unraveling with the grinder, is appropriately designed based on the difference in the grain size of the abrasive grains, the difference in the interval between the abrasive grains and the rotational speed, the difference in the ratio of water and pulp. For example, a mixture of 100 parts by weight of water and 1 part by weight of pulp is passed through a grinder about 10 to 20 times.

When a mixture with water containing finely divided cellulose fibers is obtained through the grinding step K33, polyhydric alcohols are then added to the mixture of water and finely divided cellulose (mixing step). K34a). For example, 100 parts by weight of PPG having a hydroxyl value of 400 is added to 100 parts by weight of water and mixed. In the water reduction step K34b, water is removed or reduced from the mixture containing polyhydric alcohols, water, and fine cellulose fibers. For example, dehydration under reduced pressure is performed at 130 ° C. from 100 parts by weight of PPG, 100 parts by weight of water, and 1 part by weight of the reduced-sized cellulose fiber to reduce water to 8 parts by weight. Dehydration is possible by heating the mixture above the boiling point of water without reducing the pressure.
First, the ratio of liquid to solid may be adjusted for water reduction. In the above example, the content of cellulose fiber is 1 part by weight with respect to 100 parts by weight of PPG. However, the content of cellulose fiber, which is a solid content, can be increased by filtering with a screen or the like. The fiber may be 2 parts by weight.
In the grinding process K33, since it is necessary to extrude a cellulose fiber with a liquid from the clearance gap between an abrasive grain board and an abrasive grain board, for example, a lot of liquids are required. However, in the casting / synthesis process K35 described later, the ratio of the polyhydric alcohols that are the raw materials of the matrix of the cellulose fiber-reinforced composite and the cellulose fibers that are the reinforcing fiber components is the same as the matrix of the cellulose fiber-reinforced composite and the reinforcing fibers. It is necessary to set the components in accordance with a desired ratio. In the preceding water reduction step K34b, the liquid component consisting of polyhydric alcohols and water is filtered by a screen or the like to reduce the liquid component and to be described later. Easy to adjust according to the mold / synthesis process K35.

  In order to form a polymer compound by causing a chemical reaction with the polyhydric alcohol, mixing with a compound having a functional group that causes a chemical reaction with the hydroxyl group of the polyhydric alcohol is performed (mixing step K34c). For example, 100 parts by weight of PPG, 8 parts by weight of water, 1 part by weight of cellulose fiber, and 230 parts by weight of 4,4-diphenylmethane diisocyanate are mixed. For example, the mixing is stirred with a mixer for 7 seconds.

  Next, after stirring within the mixing time, it is quickly poured into the mold. After elapse of the rise time from the cream time, it is aged in a heating furnace and taken out (casting / synthesis step K25). After demolding, a molded product of the cellulose fiber reinforced composite is completed by cutting the taken out cellulose fiber reinforced composite (finishing step K36). However, the finishing steps K16 to K36 shown in the first to third embodiments are not essential steps for the invention.

  As described above in the first to third embodiments, the reduced-sized cellulose is dispersed in polyhydric alcohols having a boiling point or decomposition temperature higher than the boiling point of water, and 100 parts by weight of the polyhydric alcohols. Those having a water content not exceeding 10 parts by weight are easy to use for the synthesis of polymer compounds. Even if the water content exceeds 10 parts by weight, it is not unusable, but in order to expand the application, it is better to use less, and here 10 parts by weight is taken as one standard. A mixture of polyhydric alcohols and cellulose fibers is chemically stable and easy to handle, and is suitable for distribution.

  It is process drawing which shows one manufacturing method of the cellulose fiber reinforced composite_body | complex which concerns on 1st Embodiment of this invention.   It is sectional drawing which shows typically an example of the grinding machine of the cellulose fiber of this invention.   It is process drawing which shows one manufacturing method of the cellulose fiber reinforced composite_body | complex which concerns on 2nd Embodiment of this invention.   It is process drawing which shows one manufacturing method of the cellulose fiber reinforced composite_body | complex which concerns on 3rd Embodiment of this invention.

Explanation of symbols

1, 2, Abrasive plate, 3 Supply pipe, 4 Electric motor, 5 Drive shaft, 6 Grinding chamber, 7 Grinding space, 8 Rotary blade for feeding, K13 to K33 Grinding process

Claims (7)

Liquid polyhydric alcohol containing cellulose fibers having a fiber diameter in the range of 10 nm to 400 nm (hereinafter referred to as thinned cellulose fibers) or a liquid polyhydric alcohol derivative having a plurality of hydroxyl groups (hereinafter, the polyhydric alcohol and the derivative) And preparing a liquid polyhydric alcohol)),
A second step of synthesizing and molding a polymer compound by reacting a compound having a plurality of functional groups chemically bonded to the hydroxyl group of the liquid polyhydric alcohol;
A method for producing a cellulose fiber reinforced composite. The first step includes
By using paper or pulp as a raw material, by applying physical force to the raw material in the liquid polyhydric alcohols so that there is a fiber diameter of the cellulose fiber within the range of 10 nm to 400 nm, The method for producing a cellulose fiber-reinforced composite according to claim 1, comprising a step of preparing a liquid polyhydric alcohol containing the thinned cellulose fiber. The first step includes
The raw material is a liquid polyhydric alcohol having a boiling point higher than the boiling point of water or a decomposition temperature so that there is a fiber or fiber having a fiber diameter in the range of 10 nm to 400 nm. And a step of preparing a liquid polyhydric alcohol containing the finely divided cellulose fiber and water by grinding together with the finely divided cellulose, the water and the polyhydric alcohol above the boiling point of water. The method for producing a cellulose fiber-reinforced composite according to claim 1, comprising a step of evaporating moisture by reducing the water temperature. The first step includes
A first pretreatment step of unwinding cellulose fibers by applying physical force to the raw materials in water such that paper or pulp is used as a raw material and the fiber diameter of the cellulose fibers falls within the range of 10 nm to 400 nm;
In the aggregate of cellulose fibers containing water produced in the first pretreatment step, liquid polyhydric alcohols having a boiling point or decomposition temperature higher than the boiling point of water are added or liquid polyhydric alcohols and at least water A second pretreatment step to replace a part;
The method for producing a cellulose fiber reinforced composite according to claim 1, comprising:   The cellulose fiber reinforced composite manufactured by the manufacturing method of the cellulose fiber reinforced composite as described in any one of Claims 1-4.   6. The cellulose fiber reinforced composite according to claim 5, wherein the polymer compound has bubbles. A material for producing a cellulose fiber reinforced composite for producing a cellulose fiber reinforced composite in which a thin cellulose fiber is dispersed in a polymer compound,
Cellulose containing liquid polyhydric alcohols having a boiling point or decomposition temperature higher than the boiling point of water and finely divided cellulose fibers, and the water content does not exceed 10 parts by weight with respect to 100 parts by weight of the liquid polyhydric alcohols Material for manufacturing fiber reinforced composites.

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