JP6005470B2 - Method for producing cellulose fiber-containing resin - Google Patents

Description

  The present invention relates to a method for producing a cellulose fiber-containing resin, and more particularly to a method for producing a resin containing fibrillated cellulose fibers.

  For the purpose of improving the physical properties of resin products, for example, improving the mechanical strength such as elastic modulus and bending strength, and reducing the thermal expansion coefficient, the resin material for producing resin products is granular or fibrous made of organic or inorganic substances. Often, this filler is blended. As such fillers, various new materials such as fine particles such as silica fine particles and metal fine particles and whisker type have been developed and provided. Is attracting attention. In addition to being suitable for improving the physical properties as described above, the cellulose fiber has a specific gravity of 4 to 6 compared to a specific gravity of a general filler made of an inorganic material. Compared to the use of fillers, it has the advantage of contributing to weight reduction of resin products, and in addition to the development of fine fiber technology in recent years, the required physical properties can be improved with a smaller amount of compound than inorganic fillers. This is because it can be expected.

  Cellulose fibers used as fillers need to improve dispersibility in the resin material by defibrating. In general, cellulose fibers are often defibrated in an aqueous medium. In this case, as the defibration progresses, interaction between the hydroxyl group or methylol group of cellulose and the aqueous medium due to hydrogen bonding force or the like occurs. It becomes difficult to prepare a high-concentration dispersion of cellulose fibers because the dispersion of fibrillated cellulose fibers becomes strong and thickens. For this reason, normally, only a dispersion having a fibrillated cellulose fiber concentration of about 1% by mass can be obtained, and a dispersion having the same concentration of about 5% by mass even when sacrificing the degree of cellulose fiber fibrillation is sacrificed. Can only be obtained.

  In the case of blending the cellulose fiber of the dispersion prepared using an aqueous medium into the resin material, it is necessary to evaporate the aqueous medium from the dispersion, but the cellulose fiber concentration in the dispersion is 1 to 5 mass as described above. Therefore, it is necessary to evaporate an aqueous medium 20 to 100 times the cellulose fiber in this evaporation operation, and the cost becomes very high. Further, in this evaporation process, the fibrillated cellulose fibers may aggregate, and in this case, the dispersibility of the cellulose fibers in the resin material is reduced.

  Therefore, various alternative methods have been proposed for the method of blending cellulose fibers and resin materials. For example, in Patent Document 1, a water-containing fiber aggregate is produced by wet-pulverizing cellulose fibers in an aqueous suspension of cellulose fibers and then filtering the water suspension, and is included in the water-containing fiber aggregate. A method is disclosed in which after replacing water with a medium such as a water-soluble organic solvent, the medium is further replaced with a liquid material of a matrix material such as a resin or a resin precursor. Patent Document 2 discloses a method of dispersing a cellulose fiber that has been defibrated in a solvent having dispersibility of the cellulose fiber and solubility of the resin, and dissolving and mixing the resin, and then removing the solvent. ing. Furthermore, Patent Document 3 discloses a method of blending a resin material with a dispersion obtained by wet-grinding cellulose fibers in an organic solvent.

  In the method described in Patent Document 1, since a resin product is manufactured by curing a liquid material of a matrix material replaced with a medium solution, a resin product in which fibrillated cellulose fibers are uniformly dispersed is obtained. It is difficult to manufacture. Moreover, since the method described in Patent Document 2 tends to cause aggregation of the cellulose fibers dispersed in the solvent when the resin is dissolved in the solvent in which the fibrillated cellulose fibers are dispersed, the cellulose fibers are added to the resin. It becomes difficult to disperse uniformly. Furthermore, in the method described in Patent Document 3, the cellulose fibers are uniformly dispersed in the resin because the cellulose fibers in the dispersion are likely to aggregate when the dispersion of the cellulose fibers is blended with the resin material. It becomes difficult.

  Thus, it is difficult to prepare resin materials in which cellulose fibers are uniformly dispersed by these alternative methods, and resin products obtained using resin materials obtained by these alternative methods have physical properties as expected. It may not be improved.

JP 2006-241450 A JP 2008-024795 A JP 2011-006598 A

  An object of the present invention is to uniformly disperse fibrillated cellulose fibers in a resin without using an aqueous medium.

The present invention relates to a method for producing a resin containing cellulose fibers, and this production method defibrates raw material cellulose fibers in a resin precursor A used for preparing a resin, and It includes a step of producing a resin precursor dispersion and a step of preparing a resin by polymerizing the resin precursor dispersion. In this manufacturing method, when the raw material cellulose fiber is defibrated so that the fiber diameter of the cellulose fiber is more than 1 μm and not more than 30 μm in the step of producing the resin precursor dispersion, and the resin precursor dispersion is polymerized. In addition, a resin precursor B different from the resin precursor A contained in the resin precursor dispersion necessary for preparing the resin is mixed with the resin precursor dispersion.

The fiber diameter of the raw material cellulose fiber used in this production method is usually preferably 100 μm or less. Moreover, this manufacturing method, usually, sets the content of the cellulose fibers in wood fat precursor dispersion to 1-30 mass%.

The melting point of the resin precursor A used in this production method is usually 100 ° C. or lower.

An example of the resin precursor A used in this production method is at least one selected from the group consisting of glycols, glycerols and pentaerythritol derivatives. Another example of the resin precursor A is at least one selected from the group consisting of an epoxy compound and an oxetane compound. Still another example of the resin precursor A is at least one selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester.

Other according to aspect the present invention relates to method for producing a cellulose fiber-containing resin molded body, the manufacturing method, you molded cellulose fiber-containing resin obtained by the method for producing a cellulose fiber-containing resin according to the present invention Is.

In the method for producing a cellulose fiber-containing resin according to the present invention, since the raw cellulose fibers are defibrated in the resin precursor A used for preparing the resin, the defibrated cellulose fibers are uniformly contained in the resin. Can be dispersed.

Since the method for producing a cellulose fiber-containing resin molded product according to the present invention is obtained by molding the cellulose fiber-containing resin obtained by the production method of the present invention, the cellulose fiber-containing resin molded product obtained by this production method is based on cellulose fibers. Easy to improve physical properties.

In the method for producing a cellulose fiber-containing resin according to the present invention, first, a raw material cellulose fiber is defibrated in a resin precursor (corresponding to the resin precursor A) used for preparing a target resin, and a resin of cellulose fiber is obtained. A precursor dispersion is produced.

  If the raw material cellulose fiber used at this process contains a cellulose, the kind will not be specifically limited, The thing derived from a plant (For example, wood, cotton, bamboo, hemp, jute, kenaf, etc.) Derived from plant materials, fabrics made from plant materials, pulp, paper or waste paper, etc.), derived from seaweeds (such as valonia and shigusa), derived from animals It may be derived from any one (for example, derived from ascidians) or derived from bacteria (so-called bacterial cellulose). However, since it is usually easy to obtain, it is preferable to use cellulose fibers derived from plants as raw material cellulose fibers.

  In general, the raw material cellulose fiber used in this step preferably has a fiber diameter of 100 μm or less, and more preferably 50 μm or less. As the raw material cellulose fiber having such a fiber diameter, a commercially available one may be used, or a cellulose material (for example, commercially available dissolved pulp or cotton linter pulp) derived from the above-described material is finely pulverized. What was prepared by grind | pulverizing using may be used.

  The fiber diameter of the raw material cellulose fiber does not mean that the fiber diameter of all the raw material cellulose fibers is 100 μm or less, and the fiber diameter of 50% or more of the cellulose fiber is based on the mass of the raw material cellulose fiber used. Means 100 μm or less. The fiber diameter of the raw material cellulose fiber can be determined by placing an appropriate amount of the raw material cellulose fiber on a glass plate or the like as a sample and observing it with the naked eye using a microscope.

  The resin precursor used in this step is a material that can form a target resin by itself or together with other resin precursors by various polymerization reactions, and is a liquid that can fibrillate the raw material cellulose fibers. It is not particularly limited as long as it is, and it is usually various monomers, oligomers or prepolymers.

  The target resin is not particularly limited because it can be appropriately selected according to the type of resin product produced using the cellulose fiber-containing resin obtained by the production method of the present invention. For example, a polyester resin , Polyurethane resins (including alkylene oxide resins modified by using polyfunctional isocyanate compounds), polylactone resins, lactone copolymer resins, polylactam resins, lactam copolymer resins, phenol resins, epoxy resins or acrylic resins. .

  Examples of the resin precursor for preparing the polyester resin or polyurethane resin include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol and diethylene glycol, glycerols such as glycerol, glycerol ether and glycerol ester, And pentaerythritol derivatives such as pentaerythritol triacrylate, and phthalic acid esters such as diethylene terephthalate and dibutyl terephthalate.

  Examples of the resin precursor for preparing the polylactone resin or lactone copolymer resin include lactones such as propiolactone and butyrolactone. Examples of the resin precursor for preparing the polylactam resin or the lactam copolymer resin include lactams such as valerolactam and caprolactam. Examples of the resin precursor for preparing the phenol resin include phenols such as phenol, o-cresol and m-cresol. Examples of the resin precursor for preparing the epoxy resin include glycidyl compounds such as epichlorohydrin, allyl glycidyl ether, 2-ethylhexyl glycidyl ether and phenyl glycidyl ether, and novolac type epoxy resins, N, N, O-triglycidyl-m. Epoxy compounds such as polyfunctional epoxy compounds having two or more epoxy groups such as aminophenol and N, N, O-4-amino-3-methylphenol, bis (3-ethyl-3-oxetalmethyl) ether, 2 Oxetane compounds such as -ethylhexyloxetane, xylylenebisoxetane and 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane (for example, "OXT-221" from Toagosei Co., Ltd.) Cited . Examples of the resin precursor for preparing the acrylic resin include acrylic acid and methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and propyl acrylate. Acrylates and methacrylates such as propyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate.

  The resin precursor used in this step has a melting point of 100 ° C. or lower, more preferably normal temperature (25 ° C.) or lower. In order to defibrate and disperse the raw material cellulose fibers in the resin precursor, the resin precursor needs to be in a liquid state and has a low viscosity, so a resin precursor having a melting point exceeding 100 ° C. is used. If so, the defibrating work of the raw material cellulose fiber in this step may be complicated or difficult. Moreover, since melting | fusing point exceeds 100 degreeC, since there exists a tendency for the polymerization reaction and decomposition reaction of a resin precursor to advance easily during the defibration of raw material cellulose fiber, execution of this process may become difficult.

  In this step, two or more types of resin precursors may be used in combination.

  The mixing ratio of the raw material cellulose fibers with respect to the resin precursor can be adjusted according to the amount of cellulose fibers contained in the resin product produced using the cellulose fiber-containing resin obtained by the production method of the present invention.

  Here, when the raw material cellulose fibers are defibrated in an aqueous medium, it is difficult to prepare a high-concentration cellulose fiber dispersion because the aqueous medium thickens. Since the viscosity of the resin precursor is less likely to increase due to the fine fibers, the mixing ratio of the raw material cellulose fibers to the resin precursor can be set large. Specifically, in the resin precursor dispersion liquid prepared in this step, the ratio of raw material cellulose fibers can be set to 1 to 30% by mass. However, since the raw cellulose fibers can be defibrated more stably, this ratio is usually preferably set to 1 to 20% by mass and more preferably 1 to 10% by mass. If the ratio of the raw material cellulose fibers is less than 1% by mass, it may be difficult to give the effect of improving physical properties by using the cellulose fibers to the resin product. On the contrary, if it exceeds 30% by mass, it becomes difficult to disentangle the raw cellulose fibers uniformly and finely in the resin precursor, so that the defibrating efficiency of the raw cellulose fibers may decrease, Since the viscosity of the resin precursor dispersion becomes high, polymerization in the next step may be difficult.

  As a method for defibrating the raw material cellulose fibers in the resin precursor, the same mechanical method as that for defibrating the raw material cellulose fibers in an aqueous medium can be employed. For example, a method using a grinder such as a high-pressure homogenizer, a multi-screw extruder, or a stone mill type or a ball mill can be employed.

  In this step, the raw material cellulose fiber is preferably defibrated so that the fiber diameter of the fine cellulose fiber after defibration exceeds 1 μm and is 30 μm or less. More preferably, the fiber is defibrated so that the fiber diameter exceeds 1 μm and is 20 μm or less. Thereby, the fibrillated cellulose fiber can be uniformly and stably dispersed in the resin precursor. When the fiber diameter after defibration is 1 μm or less, the dispersibility of the cellulose fiber after defibration in the resin precursor dispersion is likely to be lowered, and thus surface treatment for increasing dispersibility with respect to the raw material cellulose fiber, etc. Unless the special treatment is applied, it may be difficult to increase the dispersibility of the cellulose fibers in the resin precursor. On the other hand, when the fiber diameter after defibration exceeds 30 μm, the dispersibility may deteriorate and the expected physical properties may not be obtained.

  When the raw cellulose fiber is defibrated so that the fiber diameter of the cellulose fiber after defibration is in the above range, it is not necessary that all the fiber diameters of the cellulose fiber after defibration are in the above range, and the cellulose fiber after defibration Most specifically, the fiber diameter of the cellulose fiber corresponding to 50% by mass or more of the raw material cellulose fiber used may be in the above range. The fiber diameter of the cellulose fiber after defibration can be determined by thinly applying a part of the resin precursor dispersion on a glass plate as a sample and observing it with the naked eye using a microscope.

  In this step, two or more types of resin precursor dispersions can be prepared according to the type of the target resin. For example, in the case of producing a polyester resin containing cellulose fibers by the production method of the present invention, in at least one polyol compound selected from the group consisting of glycols, glycerols and pentaerythritol derivatives as resin precursors The first resin precursor dispersion is prepared by defibrating the raw material cellulose fiber in Step 2, and the second resin precursor dispersion is obtained by defibrating the raw material cellulose fiber in the phthalates as the resin precursor. A liquid can be prepared.

  For example, when preparing acrylic resin, when acrylic acid or methacrylic acid and acrylic acid ester or methacrylic acid ester are used in combination as the resin precursor, it is possible to further improve the fibrillation efficiency of the raw material cellulose fiber. If there is, the first resin precursor dispersion is prepared by defibrating the raw cellulose fibers in acrylic acid or methacrylic acid, and the raw cellulose fibers are defibrated in the acrylic ester or methacrylic ester. Another second resin precursor dispersion can also be prepared.

  In the production method of the present invention, the desired resin is then prepared by polymerizing the obtained resin precursor dispersion. Thereby, the target cellulose fiber containing resin is obtained.

  The resin precursor dispersion polymerized in this step may be a single one as long as the target resin can be prepared by itself, or two or more kinds if necessary for the preparation of the target resin. A combination of these may be used. For example, when two or more types of resin precursor dispersions are prepared in the previous step, the prepared two or more types of resin precursor dispersions can be mixed in the polymerization in this step.

In this step, the resin precursor dispersion is prepared by reacting with other materials necessary for preparing the target resin, for example, the resin precursor contained in the resin precursor dispersion. Possible resin precursors different from the resin precursors contained in the resin precursor dispersion ( corresponding to the resin precursor B, usually various monomers, oligomers or prepolymers), polymer materials, solvents Or various additives (for example, polymerization initiator, polymerization catalyst, modifier, antioxidant, antistatic agent, UV absorber, heat stabilizer, anti-glare stabilizer, plasticizer, flame retardant or antibacterial agent) You can also Two or more kinds of other materials may be mixed here.

  The polymerization method in this step is not particularly limited, and can be performed by various polymerization methods such as addition polymerization, polycondensation, or addition condensation depending on the type of the resin precursor to be used.

  When the cellulose fiber is used for the purpose of, for example, improving the mechanical strength of the resin product or suppressing the thermal expansion coefficient, the content of the cellulose fiber in the resin obtained by polymerization in this step is 1 to 20% by mass It is preferably set, more preferably 2 to 15% by mass, and even more preferably 3 to 10% by mass.

  The cellulose fiber-containing resin obtained in this step can be used as a production material for various resin products, and can be molded into a required shape by various molding methods such as press molding, injection molding, or extrusion molding. The resin product, which is a molded product obtained from this cellulose fiber-containing resin, is in a state where the cellulose fibers are uniformly dispersed. Therefore, the expected physical properties such as improvement of mechanical strength and reduction of thermal expansion coefficient due to cellulose fibers are obtained. The improvement effect can be imparted uniformly. For this reason, this resin product can be widely used as various industrial fields such as automobile materials and building materials.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1
Dissolving pulp (“NDPS” from Nippon Paper Chemical Co., Ltd.) was pulverized using a fine crusher (Horai Co., Ltd. mesh mill, model number “HA-2542”, screen diameter 0.35 mmφ) to obtain raw cellulose fibers (Fiber diameter 30 μm). 20 parts by mass of the raw material cellulose fiber and 80 parts by mass of ethylene glycol (dehydrated) (reagent grade 1 of Wako Pure Chemical Industries, Ltd.) were charged into a planetary ball mill (Lecce ’s model number “Type PM100”) and rotated. The raw material cellulose fiber was defibrated by processing at several 300 rpm for 6 hours. Thereby, a dispersion liquid in which cellulose fibers were uniformly dispersed in ethylene glycol was obtained. The fiber diameter of the cellulose fiber in the dispersion was 10 μm.

  In addition, the fiber diameter of the raw material cellulose fiber and the cellulose fiber in the dispersion liquid is thinly arranged or coated on a glass plate using a part of the raw material cellulose fiber or the dispersion liquid as a sample, and the digital microscope (Keyence Corporation model number “VHX” is used. -600 ") to determine with the naked eye. The same applies to other examples and comparative examples described later.

Nitrogen gas was vented at a flow rate of 4 m ³ / hr through a 0.6 kL table kneader (model number “PBV-0.6” manufactured by Irie Shokai Co., Ltd.), and 75 g of the resulting dispersion (60 g of ethylene glycol) Cellulose fibers (15 g uniformly dispersed with respect to 0.97 mol) and polyethylene glycol 20000 (Wako Pure Chemical Industries, Ltd., reagent grade 1) 75 g (0.0038 mol) were charged. The contents of the table kneader were treated at a temperature of 140 ° C. and a rotation speed of 70 rpm for 2 hours under a state where nitrogen gas was passed at the above flow rate to remove moisture in the contents. Then, after adding 0.3 g of dioctyltin dilaurate as a polymerization catalyst to the contents with a syringe, 152.79 g (0.58 mol) of dicyclohexylmethane-4,4-diisocyanate was further added, and the temperature was 140 ° C. The reaction was performed at several 70 rpm for 1 hour. Thereby, a cellulose fiber-containing modified alkylene oxide resin was obtained.

  A basket-like cellulose fiber-containing modified alkylene oxide resin taken out from a table kneader is charged into a 100 mm × 100 mm × 3 mmt metal frame and molded at room temperature using a small heat press (model number “HA-2003” manufactured by ASONE Corporation). A preformed sheet was prepared. A preformed sheet obtained using a 40T press (manufactured by Gonno Seisakusho) was pressed at 120 ° C. and 2 MPa for 5 minutes to obtain a 100 mm × 100 mm × 2 mmt press sheet (cellulose fiber content: 4.95% by mass). Produced.

Comparative Example 1
The same operation as in Example 1 was carried out without using raw material cellulose fibers to produce a modified alkylene oxide resin containing no cellulose fibers. And using this modified | denatured alkylene oxide resin, it carried out similarly to Example 1, and produced the press sheet of 100 mm x 100 mm x 2 mmt.

Example 2
Cotton linter pulp (manufactured by Baccai Technologies) was pulverized using a fine pulverizer (mesh mill manufactured by Horai Co., Ltd., model number “HA-2542”, screen diameter 0.35 mmφ) to obtain raw material cellulose fibers (fibers) Diameter 20 μm). 5 parts by mass of a raw material cellulose fiber obtained using Disper (model number “TK AUTO MIXER AZ-20” manufactured by Primix Co., Ltd.) and an oxetane compound (3-ethyl-3 {[(3-ethyloxetane-3- Yl) methoxy] methyl} oxetane: “OXT-221” manufactured by Toagosei Co., Ltd.) and 95 parts by mass were stirred at a rotational speed of 5000 rpm for 5 minutes and mixed. The obtained mixture was charged into a planetary ball mill (model number “Type PM100” manufactured by Lecce Co., Ltd.) and treated at a rotational speed of 300 rpm for 6 hours to defibrate the raw cellulose fibers. Thereby, a dispersion liquid in which cellulose fibers were uniformly dispersed in the oxetane compound was obtained. The fiber diameter of the cellulose fiber in the dispersion was 1 μm.

  200 g of a dispersion (obtained by uniformly dispersing 10 g of cellulose fibers with respect to 190 g of the oxetane compound) was charged in a desktop kneader (model number “PBV-0.6” manufactured by Irie Shokai Co., Ltd.) having an internal volume of 0.6 L. . To this, 67 g of an epoxy compound (3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate: “CEL2021P” manufactured by Daicel Corporation) was added and mixed at room temperature, and then the temperature of the mixture was changed to 80. The polymer was further heated to 16 ° C. and 16 g of a polymerization initiator (“San-Aid SI-100L” from Sanshin Chemical Industry Co., Ltd.) was further added. While raising the temperature of the contents of the table kneader stepwise to 180 ° C., a polymerization reaction was carried out at a rotation speed of 50 rpm for 5.5 hours to obtain a cellulose fiber-containing epoxy resin.

  The cellulose fiber-containing epoxy resin taken out from the table kneader was poured into a dumbbell No. 2 mold for measuring physical properties at 180 ° C., and cooled to room temperature to be cured. This obtained the sheet | seat (cellulose fiber content: 3.5 mass%) of thickness 1mm.

Comparative Example 2
The same operation as in Example 2 was performed without using the raw material cellulose fiber, to obtain an epoxy resin containing no cellulose fiber. Then, using this epoxy resin, a sheet having a thickness of 1 mm was produced in the same manner as in Example 2.

Evaluation 1
Tensile tests were performed on the resin molded bodies (sheets) obtained in Examples 1 and 2 and Comparative Examples 1 and 2, respectively.

  About the resin molding obtained in Example 1 and Comparative Example 1, in accordance with JIS K7161, tensile stress (tensile stress at 5% strain and 10% strain) using the following test piece and measuring device, The breaking stress (tensile stress at break) and breaking strain (elongation at break) were measured. The results are shown in Table 1.

Test piece: 1BA type small test piece made from resin molded body (press sheet) Measuring instrument: “Autograph AGS-J type” manufactured by Shimadzu Corporation

  On the other hand, the resin moldings obtained in Example 2 and Comparative Example 2 are based on JIS K7113, and using the following test piece and measuring device, tensile strength (tensile strength at break), elongation (at break) Elongation) was measured. The results are shown in Table 1.

Test piece: Sheet measuring instrument obtained in Example 2 or Comparative Example 2: "Autograph AGS-J type" manufactured by Shimadzu Corporation

Example 3
Dissolving pulp (“LDP-R” from Nippon Paper Chemical Co., Ltd.) was pulverized using an ultracentrifugal crusher (model number “ZM200 type” from Lecce Co., Ltd., screen diameter 0.12 mmφ) to obtain raw material cellulose fibers ( Fiber diameter 40 μm). 10 parts by mass of the raw material cellulose fiber and 90 parts by mass of acrylic acid (special grade of Wako Pure Chemical Industries, Ltd.) were charged into a planetary ball mill (Lecce ’s model number “Type PM100”), and rotated at 300 rpm for 6 hours. The raw material cellulose fiber was defibrated by processing. Thereby, a dispersion liquid in which cellulose fibers were uniformly dispersed in acrylic acid was obtained. The fiber diameter of the cellulose fiber in the dispersion was 20 μm.

  In a 500 ml four-necked flask equipped with a stirrer, thermometer, nitrogen blowing tube and cooling tube, 5 g of cellulose fiber is uniformly dispersed with respect to 50 g of the obtained dispersion (45 g (0.625 mol) of acrylic acid). ), 0.225 g of pentaerythritol allyl ether, 0.081 g (0.00035 mol) of 2,2′-azobismethylisobutyrate, 121.8 g (179.1 ml) of heptane and 40.3 g of ethyl acetate (44 .8 ml) was charged. After the contents of the four-necked flask were uniformly stirred and mixed, nitrogen gas was blown into the contents in order to remove oxygen present in the upper space of the reaction vessel, the raw materials, and the solvent. And the content was hold | maintained at 60-65 degreeC under nitrogen atmosphere, and was made to superpose | polymerize for 4 hours.

  After completion of the reaction, the produced slurry is heated to 90 ° C. to distill off normal hexane, and further dried under reduced pressure at 110 ° C. and 10 mmHg for 8 hours to obtain a white coarse granular cellulose fiber-containing acrylic resin (carboxyvinyl). Polymer) 50g was obtained.

Comparative Example 3
The same operation as in Example 3 was carried out without using the raw material cellulose fiber to obtain an acrylic resin containing no cellulose fiber.

Evaluation 2
A neutralized viscous liquid was prepared using the acrylic resins obtained in Example 3 and Comparative Example 3 and evaluated. Specifically, 298.5 g of ion exchange water was put into a 500 mL beaker, and the temperature of the ion exchange water was adjusted to 25 ° C. Using a stirrer equipped with a four-blade paddle (blade diameter: 50 mm), ion-exchanged water in this beaker was stirred at a rotational speed of 300 rpm, and 1.5 g of the acrylic resin obtained in Example 3 or Comparative Example 3 was added. And dispersed for 1 hour. Then, it neutralized to pH 7 using 0.5 mass% sodium hydroxide aqueous solution, and prepared the neutralization viscous liquid.

  About the prepared neutralized viscous liquid, it is hardness (expressed as resistance to being made to flow) using "Card Meter ME303 type" of iTechno Engineering Co., Ltd., breaking force (breaking load: elastic force The limit is the force that the elastic body breaks.) Viscosity (the apparent viscosity that acts in the form of frictional force against the sample flowing on the pressure-sensitive axis, proportional to the flow rate) Expressed in the form of stress) and the viscosity was measured. The measurement conditions are as follows. The results are shown in Table 2.

Test container: 200 ml beaker Measurement conditions: load 200 g, pressure sensitive axis 16 mm, speed 7 sec / inch

Claims (8)

A method for producing a resin containing cellulose fibers,
In the resin precursor A used to prepare the resin, a process of defibrating the raw material cellulose fibers and producing a resin precursor dispersion of cellulose fibers;
And a step of preparing the resin by polymerizing the resin precursor dispersion,
In the step of producing the resin precursor dispersion, the raw cellulose fibers are defibrated so that the fiber diameter of the cellulose fibers exceeds 1 μm and is 30 μm or less,
When polymerizing the resin precursor dispersion, a resin precursor different from the resin precursor A contained in the resin precursor dispersion necessary for preparing the resin with respect to the resin precursor dispersion Mixing body B,
A method for producing a cellulose fiber-containing resin.   The manufacturing method of the cellulose fiber containing resin of Claim 1 whose fiber diameter of raw material cellulose fiber is 100 micrometers or less. The manufacturing method of the cellulose fiber containing resin of Claim 1 or 2 which sets content of the said cellulose fiber in the said resin precursor dispersion liquid to 1-30 mass%. The manufacturing method of the cellulose fiber containing resin in any one of Claim 1 to 3 whose melting point of the resin precursor A is 100 degrees C or less. The method for producing a cellulose fiber-containing resin according to any one of claims 1 to 4 , wherein the resin precursor A is at least one selected from the group consisting of glycols, glycerols and pentaerythritol derivatives. The method for producing a cellulose fiber-containing resin according to any one of claims 1 to 4 , wherein the resin precursor A is at least one selected from the group consisting of an epoxy compound and an oxetane compound. The method for producing a cellulose fiber-containing resin according to any one of claims 1 to 4 , wherein the resin precursor A is at least one selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester. . Molding a cellulose fiber-containing resin obtained by the production method according to any one of claims 1 to 7, The method for producing a cellulose fiber-containing resin molded product.