WO2020050286A1

WO2020050286A1 - Composite particles and resin composition

Info

Publication number: WO2020050286A1
Application number: PCT/JP2019/034666
Authority: WO
Inventors: 博文小野; 一文河原; 洋文内村; 三好　貴章; 正広大賀
Original assignee: 旭化成株式会社
Priority date: 2018-09-03
Filing date: 2019-09-03
Publication date: 2020-03-12
Also published as: JPWO2020050286A1; JP2021155750A; JP7385625B2; JP6896946B2

Abstract

The purpose of one embodiment of the present disclosure is to provide: composite particles which contain fine cellulose and impart a molded body with physical property stability that is good enough for practical use, while imparting the molded body with sufficient mechanical characteristics; and a resin composition which contains the composite particles. One embodiment of the present disclosure provides composite particles which contain fine cellulose and a thermoplastic resin, and which is configured such that: the ratio of the fine cellulose in the composite particles is from 10% by mass to 95% by mass (inclusive); and a dispersion liquid, which is obtained by dispersing the composite particles into dimethyl sulfoxide so that the fine cellulose concentration in the dispersion liquid is 1% by mass, has a viscosity η₁₀ at a liquid temperature of 25°C at a shear rate of 10 s^-1 is 10 mPa·s or more.

Description

Composite particles and resin composition

の一 One embodiment of the present invention relates to a composite particle containing fine cellulose and a thermoplastic resin, a resin composition containing the same, and a method for producing these.

In recent years, in the fields of automobiles, electric appliances, etc., it has been aggressive to replace parts with metal instead of resin in order to reduce product weight. In such applications, the mechanical properties and dimensional stability of the resin alone are often insufficient, and various inorganic materials such as glass fiber, carbon fiber, talc, and clay are generally added as fillers. . However, since these fillers have a large specific gravity, there is a problem that the weight of the obtained resin molded body increases.

In contrast, cellulose is known to have a high modulus of elasticity comparable to aramid fibers and a lower coefficient of linear expansion than glass fibers. In addition, the true density is as low as 1.56 g / cm ³ , which is lower than that of glass (density 2.4 to 2.6 g / cm ³ ) and talc (density 2.7 g / cm ³ ) which are used as general fillers. It is an overwhelmingly light material. It is present on Earth in large quantities as a natural resource, is regarded as an environmentally friendly material from the viewpoint of carbon neutrality, and is expected as a filler for thermoplastic resins.

In particular, in recent years, fine cellulose obtained by beating and pulverizing cellulose fibers at a high level to make the fibers finer (fibrillated) to a fiber diameter of 1 μm or less has attracted attention as a filler.

Patent Documents 1 to 4 disclose techniques for dispersing fine cellulose having a high degree of fineness and a nanometer-sized fiber in a thermoplastic resin.

In addition, cellulose is maintained in a relatively stable dispersion state in a state of being dispersed in water, but when water is removed or the like, it is difficult to obtain a good dispersion due to strong cohesion between the celluloses. is there. Therefore, as a technique for dispersing cellulose in a thermoplastic resin, for example, Patent Document 5 discloses a technique in which powdery cellulose is subjected to lipophilic treatment to obtain a mixture uniformly dispersed in a plasticizer, and then melt-kneaded with polyolefin. The technology to do this is described. Patent Literature 6 describes a technique of mixing a resin, a vegetable fiber swollen in a special liquid, and an organic liquid. Further, Patent Document 7 discloses a technique in which water is separated from a mixed dispersion obtained by previously mixing a cellulose dispersion with a resin powder having a specific particle size to obtain a cellulose / resin mixture, and then the mixture is melt-kneaded. Has been described.

International Publication No. 2011/058678 International Publication No. WO 2016/199923 Japanese Patent Publication No. 9-505329 JP 2008-001728 A JP 2016-104874 A International Publication No. 2013/133093 JP 2008-297364 A

配合 In order to mix fine cellulose in the resin, it is necessary to dry and powder the fine cellulose. However, during the drying process, the fine cellulose becomes a strong aggregate due to hydrogen bonding due to surface hydroxyl groups. At this time, the fine cellulose is hardly dispersed in the resin, and a part thereof is non-uniformly present as an aggregate.

When the dispersibility of the fine cellulose in the resin composition is non-uniform, the mechanical properties and the thermal dimensional stability are inferior to the resin composition in which an equivalent amount of the fine cellulose is completely dispersed. Become. Therefore, in order to develop the same mechanical properties and thermal dimensional stability, the amount of fine cellulose added is undesirably increased.

すると If aggregates are present in the resin composition, a molded article formed from such a resin composition is likely to be broken starting from the aggregates. That is, since the aggregates cause a difference in mechanical strength depending on the portion of the molded body, the mechanical properties of the molded body including the aggregates vary greatly. In this case, the molded article partially has a strength defect, and significantly impairs the reliability as an actual product. For this reason, while fine cellulose has its excellent properties, it is not actually used in practice.

On the other hand, impurities such as hemicellulose and lignin remain in the cellulosic material, and these may be altered by heat received during processing in an extruder, which is a general resin processing method, and may cause coloring. Are known. Cellulose itself induces various side reactions such as hydrolysis with heat during extrusion processing and moisture in the system to induce a saccharification reaction and the like, which promotes thermal deterioration due to heat in the extruder and becomes a coloring factor. Not only that, there was a problem that the extruded pellets and the molded product gave a sweet smell of burnt sugar. As described above, cellulose is expected to be used as a resin reinforcing material particularly in automotive applications because of its light weight. However, automobiles and other interior parts are exposed to the five senses (especially sight and smell) of the human being, and thus are strictly required. For these parts, cellulose must be sacrificed without sacrificing the dispersibility of cellulose in the resin. It is a major issue how to suppress coloring and odor generated during heating.

In addition, in order to mix cellulose in the resin, it is necessary to dry and powder the cellulose in advance, but the cellulose becomes a strong aggregate from a finely dispersed state in the process of separation from water, and is difficult to redisperse. In the resin composition, the particles after drying are present in a maintained form. It is said that this cohesive force is very strong because it is developed by hydrogen bonding due to the hydroxyl group of cellulose, and it is difficult to control the cellulose in the resin composition to a uniform dispersion diameter. For example, using a TEMPO oxidation catalyst or the like, there is a technique in which cellulose is refined to a basic fibril level and then blended with a resin. However, this is because cellulose is too fine, and the contribution to the improvement of slidability is small. There is a problem of becoming. In addition, there is a technique of using a device capable of giving relatively strong shear, such as a twin-screw extruder, to give strong shearing to cellulose at the time of kneading with a resin to make the cellulose finer. Is difficult to obtain, and sufficient slidability has not been imparted.

In the techniques described in Patent Documents 5 to 7, in order to improve dispersibility and heat resistance, it is necessary to add a step of performing various treatments on the cellulose material itself, resulting in an increase in cost and an economical viewpoint. Is also not preferred. In terms of performance, if the resin has a low melting point, there is some improvement, but when the cellulose material is applied to a resin having a high melting point, the problem has not yet been sufficiently solved. That is, the improvement in dispersibility and the suppression of coloring and odor cannot be achieved at the same time, and at present, a cellulose-containing resin composition having excellent dispersibility and having suppressed coloring and odor can be produced for general use. There is no technology available by the method.

で Furthermore, during the drying process, the fine cellulose becomes a strong aggregate due to hydrogen bonding due to surface hydroxyl groups. At this time, the fine cellulose is hardly dispersed in the resin, and a part thereof is non-uniformly present as an aggregate.

Therefore, one embodiment of the present disclosure provides a composite particle containing fine cellulose and a resin composition containing the composite particle, which impart sufficient mechanical properties to a molded article while providing sufficient physical property stability for practical use. The purpose is to provide.
In addition, one embodiment of the present disclosure is a method in which a cellulose reinforced resin composition having excellent redispersibility even when a fine cellulose is in a dry state, and having very little coloring and having a suppressed odor can be used for general purposes. It is an object of the present invention to provide a manufacturing method for manufacturing with.

The present invention includes the following embodiments.
[1] A composite particle containing fine cellulose and a thermoplastic resin,
The ratio of fine cellulose in the composite particles is 10% by mass or more and 95% by mass or less,
The viscosity η ₁₀ at a liquid temperature of 25 ° C. and a shear rate of 10 s ⁻¹ of a dispersion obtained by dispersing the composite particles in dimethyl sulfoxide so that the concentration of fine cellulose in the dispersion is 1% by mass is 10 mPa · s. s or more.
[2] The thixotropic index (TI), which is the ratio of the viscosity η ₁₀ at a shear rate of 10 s ⁻¹ to the viscosity η _{100 at} a shear rate of _{100 s} ⁻¹ at a liquid temperature of 25 ° C., η ₁₀ / η ₁₀₀ , is obtained. 2. The composite particle according to the above aspect 1, which is 2 or more.
[3] The composite particles according to the

above aspect

1 or 2, wherein the median particle diameter is 1 μm or more and 5000 μm or less.
[4] The composite particles according to any one of the above-described embodiments 1 to 3, wherein the thermoplastic resin is soluble in dimethyl sulfoxide.
[5] The composite particles according to the above aspect 4, wherein the thermoplastic resin is a cellulose derivative.
[6] The composite particle according to the above aspect 5, wherein the weight average molecular weight Mw of the cellulose derivative is 100,000 or less.
[7] The composite particle according to any one of Aspects 1 to 6, wherein the fine cellulose has a number average diameter of 2 nm or more and less than 1000 nm.
[8] The composite particle according to any one of Aspects 1 to 6, wherein the fine cellulose has a number average diameter of 2 nm or more and less than 500 nm.
[9] The composite particle according to any one of Embodiments 1 to 6, wherein the fine cellulose has a number average diameter of 10 nm or more and less than 100 nm.
[10] The method according to any of the above aspects 1 to 9, wherein the fine cellulose has a weight average molecular weight (Mw) of 100,000 or more and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less. The composite particles according to any one of the above.
[11] The composite particle according to any one of Aspects 1 to 10, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
[12] The composite particle according to any of the above aspects 1 to 11, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 8% by mass or less.
[13] The composite particle according to any one of Aspects 1 to 12, wherein a part of the fine cellulose is chemically modified, and the fine cellulose has an I-type crystal structure.
[14] The composite particle according to the above aspect 13, wherein the chemical modification is acetylation.
[15] The method for producing a composite particle according to any one of the above aspects 1 to 14,
A method comprising a powdering step of mixing an aqueous dispersion of fine cellulose and particles of a thermoplastic resin and then drying to collect the composite particles.
[16] An aqueous dispersion of the fine cellulose is
Fibrillation step of performing a fibrillation treatment of cellulose in an organic solvent to obtain a fine cellulose dispersion, and a purification step of substituting water for the organic solvent in the fine cellulose dispersion,
The production method according to the above aspect 15, which is prepared by the following method.
[17] The method according to the above aspect 16, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with the defibration step or after the defibration step and before the purification step.
[18] The method for producing a composite particle according to any one of the above aspects 1 to 14,
Preparation of fine cellulose / resin dispersion by adding thermoplastic resin to organic solvent dispersion of fine cellulose to obtain fine cellulose / resin dispersion in which fine cellulose is dispersed in organic solvent and thermoplastic resin is dissolved Process,
A precipitation step of obtaining a composite particle dispersion by mixing the fine cellulose / resin dispersion with a poor solvent for the thermoplastic resin and precipitating composite particles containing the fine cellulose and the thermoplastic resin;
A purification step of replacing the organic solvent in the composite particle dispersion with water to obtain an aqueous dispersion, and a powdering step of drying the aqueous dispersion to collect composite particles,
Including, methods.
[19] The method for producing composite particles according to the above aspect 18, wherein the organic solvent dispersion of fine cellulose is prepared by a defibration step of defibrating cellulose in an organic solvent.
[20] The method according to the above aspect 19, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with or after the defibration step.
[21] A method for producing a resin composition including composite particles containing fine cellulose and a thermoplastic resin, and a thermoplastic resin different from the thermoplastic resin in the composite particles,
A step of forming composite particles by the method according to any of aspects 15 to 20, and a step of kneading the composite particles and a thermoplastic resin different from the thermoplastic resin contained in the composite particles;
Including, methods.
[22] A resin composition comprising the composite particle according to any one of the above aspects 1 to 14 and a base resin.
[23] a thermoplastic resin,
0.1 to 40 parts by mass with respect to 100 parts by mass of the thermoplastic resin, fine cellulose fibers having a fiber diameter of 2 nm to less than 1000 nm, and 1 part by mass to 500 parts by mass with respect to 100 parts by mass of the fine cellulose fibers. Of a cellulose derivative,
A resin composition comprising:
[24] The above-mentioned aspect 23, wherein the fine cellulose fiber has a weight average molecular weight (Mw) of 100,000 or more and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less. Resin composition.
[25] The resin composition according to the above aspect 23 or 24, wherein the fine cellulose fibers have an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
[26] The resin composition according to the above aspect 22, wherein the base resin is a thermoplastic resin.
[27] The thermoplastic resin is selected from the group consisting of a polyolefin resin, a polyamide resin, a polyester resin, a polyacetal resin, a polyphenylene ether resin, a polyphenylene sulfide resin, and a mixture of any two or more thereof. 27. The resin composition according to any one of aspects 23 to 26 above.
[28] The above aspect, wherein the thermoplastic resin is polypropylene, and a melt mass flow rate (MFR) of the polypropylene measured at 230 ° C in accordance with ISO1133 is 3 g / 10 min or more and 30 g / 10 min or less. 28. The resin composition according to 27.
[29] The thermoplastic resin is a polyamide resin, and a ratio of a carboxyl terminal group to all terminal groups ([COOH] / [all terminal groups]) of the polyamide resin is 0.30 to 0.95. 28. The resin composition according to the above aspect 27.
[30] The thermoplastic resin is a polyester resin, and a ratio of a carboxyl terminal group to all terminal groups ([COOH] / [all terminal groups]) of the polyester resin is 0.30 to 0.95. 28. The resin composition according to the above aspect 27.
[31] The resin composition according to the above aspect 27, wherein the thermoplastic resin is a polyacetal resin, and the polyacetal resin is a copolyacetal containing 0.01 to 4 mol% of a comonomer-derived structure.
[32] The resin composition according to any of the above aspects 23 to 31, wherein the thermoplastic resin is a crystalline thermoplastic resin having a melting point of 140 ° C. or higher.
[33] The resin composition according to the above aspect 22, wherein the base resin is a thermosetting resin or a photocurable resin.
[34] The resin composition according to the above aspect 22, wherein the base resin is a rubber.
[35] The method for producing a resin composition according to any of the above aspects 22 to 32,
13. A method comprising kneading the composite particles according to any one of the above aspects 1 to 12 in the form of a dry powder or an aqueous dispersion with a thermoplastic resin in a melt-kneading molding machine, and then molding.
[36] a thermoplastic resin,
Composite particles composed of fine cellulose and a cellulose derivative,
A method for producing a resin composition comprising:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
Including, methods.
[37] The above-mentioned aspect 36, wherein the fine cellulose has a weight average molecular weight (Mw) of 100,000 or more and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less. Method.
[38] The method according to Aspect 36 or 37, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
[39] The method comprises:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
36. The method according to aspect 35, comprising:
[40] The first step is performed in a melt-kneading zone in a cylinder provided in the extruder,
40. The method according to any of aspects 36 to 39, wherein the second step is performed by supplying the composite particles from an addition port provided in the cylinder.
[41] The method according to the above aspect 40, wherein the addition port is disposed downstream of the melt-kneading zone.
[42] The method according to the above aspect 40 or 41, wherein a length (L2) from an outlet of the cylinder to the addition port is 1/2 or less of a total length (L1) of the cylinder.
[43] Any of the above aspects 40 to 42, wherein one or more counterclockwise screws for kneading and dispersing the composite particles in the thermoplastic resin are provided in a cylinder downstream of the addition port. The method described in Crab.
[44] The method for producing a resin composition according to the above aspect 33, wherein
Mixing the composite particles with a thermosetting resin and then molding and then performing a thermosetting process; or mixing the composite particles with a photocurable resin and then molding and then performing a photocuring process,
Including, methods.
[45] The method for producing a resin composition according to the above aspect 34, wherein
Mixing the composite particles with rubber, then molding and then vulcanizing.
[46] The resin composition according to any of aspects 22 to 34, wherein the coefficient of variation (standard deviation / arithmetic mean) of the tensile rupture strength of the resin composition is 15% or less.
[47] The resin composition according to any of aspects 22 to 34 and 46, wherein the tensile yield strength of the resin composition is at least 1.05 times the tensile yield strength of the thermoplastic resin.
[48] The resin composition according to any of aspects 22 to 34, 46 and 47, wherein the resin composition has a coefficient of linear expansion in a range of 0 ° C. to 60 ° C. of 80 ppm / k or less.
[49] A resin pellet formed from the resin composition according to any of aspects 22 to 34 and 46 to 48.
[50] A resin molded article formed from the resin composition according to any one of aspects 22 to 34 and 46 to 48.

The composite particles and the resin composition containing the composite particles according to one embodiment of the present disclosure can impart sufficient mechanical properties to a molded article, and further, can impart sufficient physical property stability to withstand practical use.
In addition, according to the method for producing a resin composition according to one embodiment of the present disclosure, cellulose reinforced resin having excellent redispersibility even when the fine cellulose is in a dry state, and having extremely little coloring and suppressed odor The composition can be manufactured in a generally applicable manner.

FIG. 1 is a microscope image showing an example of fine cellulose fibers. FIG. 2A is a microscope image showing an example of a cellulose whisker. FIG. 2B is a microscope image showing an example of a cellulose whisker. FIG. 3A is an explanatory diagram of a method for measuring the thermal decomposition onset temperature (T _D ) and the 1% weight loss temperature. FIG. 3B is an explanatory diagram of a method for measuring the thermal decomposition onset temperature (T _D ) and the 1% weight loss temperature. FIG. 4 is an explanatory diagram of a method of measuring the weight loss rate at 250 ° C. FIG. 5 is an explanatory diagram of a method of calculating an IR index. FIG. 6 is a schematic view showing the shape of a fender manufactured for evaluation of the defect rate of the fender in the example and the comparative example. FIG. 7 is a view of a fender showing a position where a test piece is taken out in order to measure a coefficient of variation of a linear expansion coefficient of an actual molded body in Examples and Comparative Examples.

例示 Example embodiments of the present invention will be specifically described below, but the present invention is not limited to these embodiments.

≪Composite particles≫
One embodiment of the present invention provides a composite particle containing fine cellulose and a thermoplastic resin. In one embodiment, the proportion of fine cellulose in the composite particles is from 10% by mass to 95% by mass. The lower limit of the proportion of fine cellulose in the composite particles is 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, and the upper limit is 95% by mass or less, preferably 90% by mass or less, more preferably Is 80% by mass or less. When the ratio of the fine cellulose is 10% by mass or more, in the production of the resin composition using the composite particles, the amount of the thermoplastic resin of the composite particles contained in the resin composition when the predetermined fine cellulose is added becomes too large. This is advantageous because control of the physical properties of the resin composition itself does not become difficult. When the proportion of the fine cellulose is 95% by mass, the aggregation derived from hydrogen bonds between the fine celluloses is not too strong, the dispersion of the fine cellulose in the resin composition is good, and the mechanical strength and the dimensional stability can be improved. It is advantageous.

In one embodiment, the dispersion is obtained by dispersing the composite particles in dimethyl sulfoxide (DMSO in the present disclosure) so that the concentration of fine cellulose in the dispersion is 1% by mass. The viscosity η _{10 at a} shear rate of 10 s ⁻¹ (also simply referred to as “viscosity η ₁₀ ” in the present disclosure) is 10 mPa · s or more, preferably 15 mPa · s or more, more preferably 20 mPa · s or more, and still more preferably. Is 25 mPa · s or more. When a resin composition is prepared using a composite particle having a viscosity η ₁₀ of 10 mPa · s or more, the dispersibility of fine cellulose in the resin composition is good, and the mechanical strength and dimensional stability can be improved, which is advantageous. It is. On the other hand, the upper limit of the viscosity eta ₁₀ for the higher viscosity eta ₁₀ excellent dispersibility in DMSO rises no particular. The higher the viscosity eta ₁₀ improves the dispersibility of the fine cellulose in the resin composition can achieve good improvement in mechanical strength and dimensional stability improvement. In one embodiment, from the viewpoint of easy availability of the thermoplastic resin, the upper limit of the eta ₁₀ is, 2000 mPa · s or less, or 1800 mPa · s or less, or 1500 mPa · s may be less.

In a preferred embodiment, the viscosity η _{100 of} a dispersion obtained by dispersing the composite particles in DMSO such that the concentration of fine cellulose in the dispersion is 1% by mass at a liquid temperature of 25 ° C. and a shear rate of 100 s ⁻¹ is obtained. The thixotropy index (TI), which is the ratio of the viscosity η ₁₀ at a shear rate of 10 s ⁻¹ to η ₁₀ / η ₁₀₀ , is 2 or more. Essentially, a dispersion in which fine cellulose is sufficiently dispersed has a structural viscosity that decreases as the shear rate increases. When the TI is 2 or more, the dispersibility of the fine cellulose in the composite particles is good. When a resin composition is prepared using such composite particles, the dispersion of the fine cellulose in the resin composition is reduced. It has good properties and is advantageous in improving mechanical strength and dimensional stability. TI is more preferably 3 or more, still more preferably 5 or more, and particularly preferably 7 or more. The TI is preferably large from the viewpoint of dispersibility of the fine cellulose, but may be, for example, 50 or less, or 40 or less, or 30 or less from the viewpoint of ease of production of the composite particles.

In the measurement of the viscosity (η ₁₀ and η ₁₀₀ ) of the present disclosure, first, a predetermined amount of composite particles is added to DMSO so that the fine cellulose is 1% by mass, and 100 ml of a DMSO dispersion liquid containing the composite particles is prepared. The dispersion conditions are set so that the composite particles are dispersed in DMSO by stirring the dispersion liquid or the like. For example, stirring is performed with a magnetic stirrer at a rotation speed of 300 rpm or more for 1 minute or more (more specifically, with a magnetic stirrer at 1200 rpm. , Stirring for 1 hour). After confirming that the liquid temperature is 25 ° C., an aliquot of the stirring dispersion is taken and the viscosity is measured immediately in a double cylinder geometry with a rheometer. The temperature of the apparatus is adjusted to 25 ° C. in advance. As a measurement condition, a cycle of decreasing the shear rate from 100 s ^-1 to 1 s ^-1 over 100 seconds and then increasing it to 100 s ^-1 over 100 seconds is repeated twice. Finally, the pressure is lowered from 100 s ^-1 to 1 s ^-1 over 100 seconds, and viscosity data is acquired every 1 second. Then, the viscosity at the shear rate Rs ⁻¹ is defined as η _R (for example, when the shear rate is 10 s ⁻¹ , it is denoted as η ₁₀ ).

で In the present disclosure, the median particle size of the composite particles is a value measured by a laser diffraction type particle size distribution measuring device or an image analysis type particle size distribution measuring device. The numerical value of the median particle size of the present disclosure is intended to be a numerical value obtained from at least one of these devices. The lower limit of the median particle size is preferably at least 1 μm, more preferably at least 3 μm, further preferably at least 5 μm, particularly preferably at least 10 μm. Further, the upper limit is preferably 5000 μm or less, more preferably 3000 μm or less, further preferably 1000 μm or less, and particularly preferably 500 μm or less. When the median particle diameter is 1 μm or more, it is not necessary to use a special technique in production in order to prevent secondary aggregation of the primary particles, which is preferable from the viewpoint of the production process and cost. On the other hand, when the median particle diameter is 5000 μm or less, kneading of the composite particles and the base resin is stabilized in the production of the resin composition using an extruder or the like, and as a result, the dispersibility of the fine cellulose in the resin composition is good. It is preferable.

<Fine cellulose>
“Fine cellulose” of the present disclosure means cellulose having a number average diameter of 2 nm or more and less than 1000 nm, and includes cellulose fibers and cellulose whiskers. In the present disclosure, the “length” (L) and the “diameter” (D) of the fine cellulose are, for example, the fiber length and the fiber diameter in a cellulose fiber (also referred to as a fine cellulose fiber in the present disclosure). In cellulose whiskers, they correspond to the major axis and minor axis, respectively. The number average diameter of the fine cellulose (in one embodiment, each of the cellulose whiskers and the cellulose fibers) is, in one embodiment, 4 nm or more, 10 nm or more, or 20 nm or more, or 30 nm or more, and in one embodiment, 500 nm or less, or 500 nm. Or less than 450 nm, or 400 nm or less, or 350 nm or less, or 300 nm or less, or 100 nm or less, or less than 100 nm. When the number average diameter of the fine cellulose is less than 2 nm, the crystallinity is extremely low and the dispersibility in the resin composition is poor, so that the desired tensile breaking strength and thermal stability of the resin composition (specifically, Does not provide a low coefficient of linear thermal expansion and elastic retention at high temperatures). On the other hand, when the number average diameter of the fine cellulose is 1000 nm or more, the number of entangled points of the fine cellulose in the resin composition is small, and the desired tensile strength at break and thermal stability of the resin composition cannot be obtained. Making the diameter of the fine cellulose within the above-mentioned range is advantageous from the viewpoint of improving the slidability of the molded article formed using the resin composition.

In one embodiment of the present disclosure, the fiber diameter of the cellulose fiber is preferably 4 nm or more, or 10 nm or more, or 20 nm or more, or 30 nm or more, preferably 500 nm or less, or less than 500 nm, or 450 nm or less, or 400 nm or less. , Or 350 nm or less, or 300 nm or less, or 100 nm or less, or less than 100 nm.

In one embodiment of the present disclosure, the minor axis of the cellulose whisker is preferably 4 nm or more, or 10 nm or more, 20 nm or more, or 30 nm or more, preferably 500 nm or less, or less than 500 nm, or 450 nm or less, or 400 nm or less, Or 350 nm or less, or 300 nm or less, or 100 nm or less, or less than 100 nm.

In one embodiment, the ratio (L / D) of the fiber length (L) / fiber diameter (D) of the cellulose fiber is 30 or more, preferably 50 or more, more preferably 80 or more, more preferably 100 or more, more preferably. Is 120 or more, more preferably 150 or more, more preferably 200 or more, even more preferably 300 or more, and most preferably 500 or more, and also preferably 5000 or less, more preferably 4000 or less, and still more preferably 3000 or less. Preferably it is 1000 or less. It is advantageous that the L / D of the cellulose fiber is in the above-mentioned range in terms of improving the tensile strength at break and the thermal stability of the resin composition. In one embodiment, the L / D of the cellulose fiber of 1000 or less is advantageous from the viewpoint of not increasing the melt viscosity of the resin composition too much.

In one embodiment, the ratio (L / D) of the major axis (L) / minor axis (D) of the cellulose whisker is less than 30, preferably 25 or less, more preferably 20 or less, more preferably 15 or less, more preferably. It is 10 or less, more preferably 5 or less. The L / D of the cellulose whisker is 1 or more, preferably 1.1 or more, more preferably 1.2 or more, and further preferably 1.5 or more. Having the L / D ratio of the cellulose whiskers within the above-described range is advantageous in one aspect in that a suitable fluidity can be imparted to the resin composition.

In one embodiment, the fine cellulose is a cellulose fiber, a cellulose whisker, or a mixture thereof. The fine cellulose is a cellulose fiber or a mixture of cellulose fibers and cellulose whiskers in that the advantages of the composite particles of the present disclosure are significant. The cellulose fiber / cellulose whisker ratio (by mass) of the above mixture is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, and further preferably 70/30 to 30/70.

In one embodiment, the cellulose whiskers can improve the dispersibility of the cellulose fibers by being mixed with the cellulose fibers, and as a result, can improve the mechanical properties of the resin composition. The cellulose whisker may be chemically modified, and the aspect of the chemical modification may be the same as that of the cellulose fiber. When cellulose fibers and cellulose whiskers are combined, the amount of cellulose whiskers is preferably from 10 to 500 parts by mass, more preferably from 20 to 300 parts by mass, even more preferably from 30 to 200 parts by mass based on 100 parts by mass of the cellulose fibers. . From the viewpoint of the balance between processability and mechanical properties, it is desirable that the amount of cellulose whisker be within the above range.

The number average diameter, number average length, and L / D of fine cellulose (eg, cellulose whiskers and cellulose fibers) can be determined by using an aqueous dispersion of fine cellulose in a water-soluble solvent (eg, water, ethanol, tert-butanol, etc.). And then diluted with a high shear homogenizer (eg, Nippon Seiki Co., Ltd., trade name “Excel Auto Homogenizer ED-7”, manufactured by IKA, trade name “Ultra Turrax T18”). )), And processing conditions: disperse at 25,000 rpm for 5 minutes, cast on mica, air-dry, and use as a measurement sample, high-resolution scanning microscope (SEM) or atomic force microscope (AFM) Measure with and find. Specifically, the length and diameter of 100 randomly selected microcellulose are measured in an observation field of view in which the magnification is adjusted so that at least 100 microcellulose are observed. L / D of the fine cellulose can be calculated). Then, the average value of the diameter and length of the obtained 100 pieces is defined as the number average diameter and number average length of the fine cellulose. In one embodiment, the cellulose whiskers and the cellulose fibers may be distinguished from each other by classifying cellulose whiskers having a ratio (L / D) of less than 30 as cellulose whiskers and those having a ratio (L / D) of 30 or more as cellulose fibers. In one embodiment, when the fine cellulose is a mixture of cellulose whiskers and cellulose fibers, a total of 200 cellulose fibers of 100 or more cellulose fibers having an L / D of 30 or more and 100 or more cellulose whiskers having an L / D of less than 30 are used. The above measurement is performed.

FIG. 1 is a microscope image showing an example of fine cellulose as a cellulose fiber. It can be seen that any cellulose has a fibrous structure and has a high L / D of 30 or more. 2A and 2B are microscopic images showing examples of cellulose whiskers. FIG. 2B is a partially enlarged view of FIG. 2A. It can be seen that all celluloses have a needle-like crystal particle structure and have a low L / D of less than 30.

The length, diameter, and L / D ratio of fine cellulose (for example, each of cellulose whiskers and cellulose fibers) in the resin composition or the composite particles are determined using the solid resin composition or the composite particles as a measurement sample. It may be confirmed by measuring according to the measurement method described above. As a method for removing fine cellulose as an aqueous dispersion from the resin composition or the composite particles, a solvent in which the thermoplastic resin is dissolved (for example, 1,2,4-trichlorobenzene or 1,2-dichlorobenzene for polyolefin, For the polyamide, hexafluoro-2-isopropanol and the like can be mentioned, but the resin dissolving agent is not limited to these.) After dissolving the thermoplastic resin by filtration, fine filtration is performed using filtration or centrifugation. The cellulose is separated and washed thoroughly with the solvent. Thereafter, the solvent was replaced with pure water, and finally, a high shear homogenizer (eg, Nippon Seiki Co., Ltd., trade name “Excel Auto Homogenizer ED-7”, IKA, trade name “Ultra Turrax T18”) And an aqueous dispersion can be taken out by dispersing at a processing condition of 25,000 rpm for 5 minutes.

The number average diameter of the fine cellulose of the present embodiment may be a specific surface area equivalent diameter calculated from the specific surface area. That is, in one embodiment, the equivalent diameter of the specific surface area of the fine cellulose may be in the range of the present disclosure. In this disclosure, the specific surface area equivalent diameter is a diameter calculated from the specific surface area obtained by the BET method using nitrogen adsorption.

The specific surface area equivalent diameter is obtained by preparing a porous sheet by replacing the aqueous dispersion of fine cellulose with tBuOH and then drying it, and measuring the specific surface area of the porous sheet using the BET method by nitrogen adsorption. Value. Assuming that the fine cellulose is an ideal state in which no fusion between the celluloses occurs and the cellulose density is d (g / cm ³ ) and the diameter is D (nm), the specific surface area and the diameter are as follows. It is represented by the following equation.
Specific surface area (m ² / g) = 4000 / (dD)
When the cellulose density is 1.50 g / cm ³ , the diameter is represented by the following equation.
D (nm) = 2667 / specific surface area (m ² / g)

In a typical embodiment, the fine cellulose has a crystalline structure of cellulose type I and / or II. As crystalline forms of cellulose, type I, type II, type III, type IV and the like are known. While type I and type II celluloses are commonly used, type III and type IV celluloses are obtained on a laboratory scale but not on an industrial scale. As a fine cellulose, a resin composition having relatively high structural mobility, dispersing the fine cellulose into a resin, having a lower coefficient of linear thermal expansion, and having higher strength and elongation at the time of tensile and bending deformation. From the viewpoint of obtaining a product, fine cellulose containing cellulose type I crystal or cellulose type II crystal is preferable.

The crystal structure can be identified from a diffraction profile obtained by wide-angle X-ray diffraction using CuKα (λ = 0.15418 nm) monochromated with graphite. Cellulose type I has peaks at two positions around 2θ = 14 to 17 ° and around 2θ = 22 to 23 °. Cellulose type II has one peak at 2θ = 10 ° to 19 ° and two peaks at 2θ = 19 ° to 25 °. When cellulose type I and cellulose type II are mixed, up to six peaks are observed in the range of 2θ = 10 ° to 25 °.

微細 The crystallinity of the fine cellulose (particularly, each of cellulose fiber and cellulose whisker) of the present embodiment is preferably 50% or more. When the crystallinity is in this range, the mechanical properties (particularly strength and dimensional stability) of the fine cellulose (for example, cellulose fiber) itself increase, so that the strength and dimensional stability of the resin composition obtained by dispersing the fine cellulose in the resin are increased. Tend to be higher. The crystallinity of the fine cellulose of the present embodiment is more preferably 55% or more, or 60% or more, or 65% or more, or 70% or more, or 80% or more. Since the higher the degree of crystallinity of the fine cellulose, the more preferable it is. Therefore, the upper limit is not particularly limited, but 99% is a preferable upper limit from the viewpoint of production.

When the fine cellulose is cellulose type I crystal (derived from natural cellulose), the crystallinity is determined by the Segal method from the diffraction pattern (2θ / deg. Of 10 to 30) when the sample is measured by wide-angle X-ray diffraction. Is obtained by the following equation.
Crystallinity (%) = [I ₍₂₀₀₎ -I _(amorphous) ] / I ₍₂₀₀₎ × 100
I ₍₂₀₀₎ : Diffraction peak intensity due to 200 planes (2θ = 22.5 °) in cellulose I-type crystal I _(amorphous) : Halo peak intensity due to amorphous _{phase in} cellulose I-type crystal Peak intensity at the low angle side of 0.5 ° (2θ = 18.0 °)

When the cellulose is a cellulose II crystal (derived from regenerated cellulose), the crystallinity at 2θ = 12.6 ° attributed to the (110) plane peak of the cellulose II crystal in wide-angle X-ray diffraction. From the absolute peak intensity h0 and the peak intensity h1 from the baseline at this plane interval, it is determined by the following equation.
Crystallinity (%) = h1 / h0 × 100

The degree of polymerization (DP) of the fine cellulose is preferably 100 or more and 12,000 or less. The degree of polymerization is the number of repetitions of an anhydrous glucose unit forming a cellulose molecular chain. When the degree of polymerization of the fine cellulose is 100 or more, the tensile strength at break and the elastic modulus of the fine cellulose itself are improved, and the high tensile strength at break and the thermal stability of the resin composition are preferably exhibited. Although there is no particular upper limit on the degree of polymerization of fine cellulose, cellulose having a degree of polymerization exceeding 12,000 is practically difficult to obtain and tends to be difficult to use industrially. From the viewpoint of handleability and industrial implementation, the degree of polymerization of the fine cellulose is preferably from 150 to 8000. First, the intrinsic viscosity (JIS P 8215: 1998) of a dilute cellulose solution using a copper ethylenediamine solution is determined, and then the intrinsic viscosity of the cellulose and the polymerization degree DP have a relationship represented by the following formula (1). Is used to determine the degree of polymerization DP.
Intrinsic viscosity [η] = K x DPa (1)
Here, K and a are constants determined by the type of polymer. In the case of cellulose, K is 5.7 × 10 ⁻³ and a is 1.

In one embodiment, the degree of polymerization of the cellulose whiskers is preferably 600 or less, more preferably 300 or less, and preferably 100 or more, and more preferably 150 or more.

において In one embodiment, the weight average molecular weight (Mw) of the fine cellulose is 100,000 or more, more preferably 200,000 or more. The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight (Mn) is 6 or less, preferably 5.4 or less. The higher the weight average molecular weight, the smaller the number of terminal groups of the cellulose molecule. Further, since the ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight indicates the width of the molecular weight distribution, the smaller the Mw / Mn, the smaller the number of the terminal of the cellulose molecule. Since the end of the cellulose molecule is the starting point of thermal decomposition, not only the weight average molecular weight of the cellulose molecule of the fine cellulose is large, but also the weight average molecular weight is large and the width of the molecular weight distribution is narrow. Cellulose and a resin composite of fine cellulose and a resin are obtained. The weight average molecular weight (Mw) of the fibrous cellulose may be, for example, 600,000 or less or 500,000 or less from the viewpoint of availability of the cellulose raw material. The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight (Mn) may be, for example, 1.5 or more, or 2 or more, from the viewpoint of easy production of fibrous cellulose. Mw can be controlled in the above range by selecting a cellulose raw material having Mw according to the purpose, appropriately performing physical treatment and / or chemical treatment on the cellulose raw material within an appropriate range, and the like. Mw / Mn is also in the above range by selecting a cellulose raw material having Mw / Mn according to the purpose, appropriately performing physical treatment and / or chemical treatment on the cellulose raw material in an appropriate range, and the like. Can be controlled. In both the control of Mw and the control of Mw / Mn, the physical treatment includes dry or wet pulverization using a microfluidizer, a ball mill, a disk mill, etc., a crusher, a homomixer, a high-pressure homogenizer, and an ultrasonic device. And the like. Examples of the physical treatment for applying a mechanical force such as impact, shear, shear, friction and the like due to the above-mentioned chemical treatment include digestion, bleaching, acid treatment, regenerated cellulose and the like.

The weight-average molecular weight and number-average molecular weight of the cellulose used herein are defined as the values obtained by dissolving cellulose in N, N-dimethylacetamide to which lithium chloride has been added and then performing gel permeation chromatography using N, N-dimethylacetamide as a solvent. This is the calculated value.

The fine cellulose of the present embodiment may be chemically modified (in the present disclosure, chemically modified fine cellulose is also referred to as chemically modified fine cellulose). The chemical modification is performed on the hydroxyl groups of the cellulose molecules inside and / or on the surface of the fine cellulose, and the hydroxyl groups are replaced with desired functional groups by the cellulose modifying agent. For example, hydroxyl groups present on the surface of fine cellulose are esterified to acetate, nitrate, sulfate, phosphate, etc. (esterified fine cellulose), alkyl ethers such as methyl ether, and carboxymethyl ether. The carboxy ether, cyanoethyl ether, etc. (etherified microcellulose), which are typical, and the hydroxyl group at position 6 is oxidized by a TEMPO (2,2,6,6-tetramethylpiperidinooxy radical) oxidation catalyst. And carboxyl groups (including acid type and salt type) (carboxylated fine cellulose). The chemical modification is that the affinity between the resin and the fine cellulose is increased to improve the tensile strength at break and / or the thermal stability of the resin composition, and / or that the fibrillation between microfibrils is easily performed. This is advantageous in that the heat resistance of the fine cellulose is improved so that it can be used as a filler for engineering plastics having high heat resistance. Such chemical modification is preferably esterification, more preferably acetylation, from the viewpoint of simplifying the reaction process and improving the heat resistance of the fine cellulose itself. Chemical modification may occur on a portion (eg, inside or on the surface) of the microcellulose or on all (eg, both inside and on the surface). The cellulose skeleton can be left in the fine cellulose. For example, it is possible to chemically modify only the surface of the fine cellulose and leave a cellulose skeleton (particularly, a cellulose I-type or II-type crystal structure) in the center. When a part of the microcellulose is chemically modified and the microcellulose has a crystal structure (typically type I and / or type II, preferably type I), high tensile breaking strength and size derived from cellulose It is more preferable because the stability can be maintained, the heat resistance can be improved by chemical modification, the affinity with the resin at the time of resin composite can be improved, and the dimensional stability of the resin composition can be improved. The presence of a chemically modified group in the chemically modified fine cellulose can be confirmed by ¹ HNMR.

熱 The thermal decomposition onset temperature (Td) of the fine cellulose is not particularly limited, but when discoloration or thermal degradation of the fine cellulose by heating becomes a problem, the higher the thermal decomposition onset temperature, the more preferable. The thermal decomposition onset temperature (Td) is preferably at least 270 ° C, more preferably at least 275 ° C, further preferably at least 280 ° C, particularly preferably at least 285 ° C.

In the present disclosure, the thermal decomposition onset temperature (Td) is, as shown in the explanatory diagrams of FIGS. 3A and 3B, a thermogravimetric (TG) analysis from a graph in which the horizontal axis represents temperature and the vertical axis represents weight retention%. This is the calculated value (FIG. 3B is an enlarged view of FIG. 3A). Starting from the weight (weight loss of 0 wt%) at 150 ° C. (in a state where water is almost removed) of the fine cellulose, the temperature is further increased, and the temperature at the time of 1 wt% weight loss and the temperature at the time of 2 wt% weight loss are changed. Get a straight line through. The temperature at the point where this straight line intersects with the horizontal line (base line) passing through the starting point of the weight loss of 0 wt% is defined as the thermal decomposition onset temperature (Td). The TG analysis is composed of two steps: (1) a sample drying step and (2) a measurement step that follows the drying step. (1) In the sample drying step, the sample is heated from room temperature to 150 ° C. at a rate of 10 ° C./min in a nitrogen flow of 100 ml / min, kept at 150 ° C. for 1 hour, and then cooled to 30 ° C. Cooling. Subsequently, in the measurement step (2), the temperature is increased from 30 ° C. to 450 ° C. at a rate of 10 ° C./min in a nitrogen flow of 100 ml / min. Further, as a measurement sample, a circularly cut-out piece of the above-mentioned porous sheet of chemically modified fine cellulose is used, and 10 mg of the sample is placed in an aluminum sample pan and measured.

The 1% weight loss temperature is the temperature at the time of 1% weight loss starting from the weight of 150 ° C. when the temperature is raised by the method of the above-mentioned thermal decomposition onset temperature (Td).

As shown in the explanatory diagram of FIG. 4, the weight reduction rate of the fine cellulose of the present embodiment at 250 ° C. was determined by thermogravimetric (TG) analysis when the fine cellulose was kept at 250 ° C. under a nitrogen flow for 2 hours. Rate. The TG analysis is composed of two steps: (1) a sample drying step and (2) a measurement step that follows the drying step. (1) In the sample drying step, the temperature is raised from room temperature to 150 ° C. at a rate of 10 ° C./min in a nitrogen flow of 100 ml / min, and maintained at 150 ° C. for 1 hour. Subsequently, in the measurement step (2), the temperature is increased from 150 ° C. to 250 ° C. at a rate of 10 ° C./min in a nitrogen flow of 100 ml / min, and is maintained at 250 ° C. for 2 hours. Further, as a measurement sample, a circularly cut-out piece of the above-mentioned porous sheet of chemically modified fine cellulose is used, and 10 mg of the sample is placed in an aluminum sample pan and measured.

The zeta potential of the fine cellulose is preferably -5 mV or less. When the zeta potential is in this range, when the fine cellulose component and the base resin are compounded, good melt fluidity can be maintained without excessive bonding between the fine cellulose component and the base resin. The zeta potential is more preferably -10 mV or less, further preferably -20 mV or less, particularly preferably -25 mV or less, and most preferably -30 mV or less. The smaller the value is, the more excellent the physical properties of the compound are, so the lower limit is not particularly limited, but is preferably −10 mV or more from the viewpoint of easy production.
In the case of fine cellulose which has been chemically modified, its properties are strongly affected by the modifying groups, and therefore, good melt fluidity can be maintained even at a zeta potential exceeding -5 mV. Therefore, the zeta potential of the chemically modified fine cellulose may be outside the above range.

The zeta potential can be measured by the following method. A suspension of pure water having a concentration of 1% by mass of fine cellulose was mixed with a high-shear homogenizer (for example, Nippon Seiki Co., Ltd., trade name "Excel Auto Homogenizer ED-7", IKA, trade name "Ultra Turrax T18"). Processing conditions: A water dispersion obtained by dispersing at 25,000 rpm for 5 minutes at a rotation speed was diluted with pure water to 0.01 to 0.5% by mass, and a zeta potentiometer (for example, an apparatus manufactured by Malvern Co., Ltd. It is measured at 25 ° C. and pH 7 using the name Zetasizer Nano ZS).

微細 The fine cellulose of the present embodiment may contain an acid-insoluble component containing lignin and / or an alkali-soluble polysaccharide containing hemicellulose and the like. The contents of the acid-insoluble component and the alkali-soluble polysaccharide affect the heat resistance of fine cellulose and the dispersibility in the resin composition, and may be adjusted according to the purpose. In general, when the content of the acid-insoluble component and the alkali-soluble polysaccharide is large, the heat resistance of the fine cellulose is reduced, the discoloration accompanying the content is reduced, and the mechanical properties of the fine cellulose are reduced. Therefore, for example, when producing a resin composition using a resin that is melt-kneaded at a high temperature such as a polyamide resin, it is preferable that the average content of the acid-insoluble component and the alkali-soluble polysaccharide in the cellulose raw material is preferably smaller. is there.

The average content of the acid-insoluble component in the fine cellulose (average lignin content in one embodiment) is preferably less than 10% by mass, more preferably 8% by mass or less, still more preferably 7% by mass or less, and still more preferably 6% by mass. %, Most preferably 5% by mass or less. The average content of the acid-insoluble component may be 0% by mass, but from the viewpoint of easy production of fine cellulose, for example, 0.1% by mass or more, or 0.5% by mass or more, or 1% by mass or more, or It may be 2% by mass or more, or 3% by mass or more.

定量 The quantitative determination of the acid-insoluble component is performed as the quantitative determination of the acid-insoluble component using the Klason method described in Non-Patent Document (Wood Science Experiment Manual, edited by The Japan Wood Science Society, pp. 92-97, 2000). This method is understood in the art as a method for measuring the amount of lignin. The sample is stirred in a sulfuric acid solution to dissolve cellulose, hemicellulose, and the like, and then filtered through a glass fiber filter, and the obtained residue corresponds to the acid-insoluble component. The content of the acid-insoluble component is calculated from the weight of the acid-insoluble component, and the number average of the content of the acid-insoluble component calculated for the three samples is defined as the average content of the acid-insoluble component.

The average content of alkali-soluble polysaccharides in fine cellulose (in one embodiment, the average content of hemicellulose) is preferably 13% by mass or less, more preferably 12% by mass or less, more preferably 8% by mass or less, further preferably 5% by mass or less. % By mass or less. The alkali-soluble polysaccharide average content may be 0% by mass, but from the viewpoint of easy production of fine cellulose, for example, may be 1% by mass or more, or 3% by mass or more, or 6% by mass or more. Good. In a preferred embodiment, the fine cellulose has a value in the above range as the average content of the alkali-soluble polysaccharide, and has a value in the range of the present disclosure (particularly preferably 60% or more) as the crystallinity.

アルカリ The alkali-soluble polysaccharide in the present disclosure includes β-cellulose and γ-cellulose in addition to hemicellulose. The alkali-soluble polysaccharide is a component obtained as an alkali-soluble polysaccharide from holocellulose obtained by subjecting a plant (eg, wood) to solvent extraction and chlorination (ie, a component obtained by removing α-cellulose from holocellulose). As understood by those skilled in the art. Alkali-soluble components are polysaccharides containing hydroxyl groups and have poor heat resistance, decompose when heated, cause yellowing during thermal aging, and cause inconvenience such as a decrease in the strength of cellulose fibers. It is preferable that the content of the alkali-soluble polysaccharide in the fine cellulose is small, because it can cause the occurrence.

The content of the alkali-soluble polysaccharide can be determined by the method described in Non-Patent Document (Wood Science Experiment Manual, edited by The Japan Wood Science Society, pp. 92-97, 2000), and is calculated from the holocellulose content (Wise method). It is determined by subtracting the cellulose content. This method is understood in the art as a method for measuring the amount of hemicellulose. The alkali-soluble polysaccharide content is calculated three times for one sample, and the number average of the calculated alkali-soluble polysaccharide content is defined as the alkali-soluble polysaccharide average content.

The average content of the acid-insoluble component and the average content of the alkali-soluble polysaccharide of the fine cellulose in the present embodiment are calculated from the average content of the acid-insoluble component and the average content of the alkali-soluble polysaccharide of the cellulose raw material used for the production of the fine cellulose. May be.

Hereinafter, a method for producing fine cellulose will be exemplified.
As a cellulose fiber (also referred to as a cellulose raw material) as a raw material of fine cellulose, natural cellulose and regenerated cellulose can be used. As natural cellulose, wood pulp obtained from wood species (hardwood or conifer), non-wood pulp obtained from non-wood species (cotton, bamboo, hemp, bagasse, kenaf, cotton linter, sisal, straw, etc.), animals (for example, Cellulose fiber aggregates derived from sea squirts), algae, microorganisms (for example, acetic acid bacteria), and microbial products can be used. Examples of the regenerated cellulose include cut yarns of regenerated cellulose fibers (such as viscose, cupra, and Tencel), cut yarns of cellulose derivative fibers, and ultrafine yarns of regenerated cellulose or cellulose derivatives obtained by electrospinning. These raw materials may be used to adjust the fiber diameter, fiber length, degree of fibrillation, etc. by beating, fibrillation, or refining by mechanical force of a beater or refiner, etc., or bleaching, refining using chemicals, and lignin And the content of non-cellulose such as hemicellulose and the like can be adjusted.

成分 Acid-insoluble components and alkali-soluble polysaccharides can be mentioned as components other than cellulose remaining in the pulp, but in a usual embodiment, these components remain even after the production of fine cellulose. The acid-insoluble component and the alkali-soluble polysaccharide contained in the fine cellulose all affect the dispersibility, heat resistance and the like of the fine cellulose in the resin composition, and may be adjusted according to the purpose. As described above, when improvement in heat resistance or the like of fine cellulose is required, it is preferable that the content of the acid-insoluble component and the alkali-soluble polysaccharide in the cellulose raw material is small and the cellulose purity (α-cellulose content) is high. There are cases. In such a case, for the raw material of the cellulose I-type crystal, it is preferable to use cellulose having a cellulose purity (α-cellulose content) of 80% by mass or more to suppress the discoloration of the resin composition and maintain the properties of the composition. Preferred from a viewpoint. The cellulose purity is more preferably at least 85% by mass, still more preferably at least 90% by mass, particularly preferably at least 95% by mass.

The cellulose purity can be determined by the α-cellulose content measuring method described in Non-Patent Document (Wood Science Experiment Manual, edited by The Japan Wood Science Society, pp. 92-97, 2000).

For the raw material of the cellulose II crystal, a lower cellulose purity may be exhibited when the α-cellulose content measuring method is used (originally, the α-cellulose content measuring method is a raw material of the cellulose I crystal, such as wood). For the method developed in the analysis). However, since the raw material of the cellulose II crystal is a product processed and manufactured from the cellulose I crystal (for example, viscose rayon, cupra, lyocell, mercerized cellulose, etc.), the cellulose purity is originally high. Therefore, even if the cellulose purity is less than 85% by mass, it is preferable as the raw material of the fine cellulose of the present embodiment.

微細 Fine cellulose is obtained by applying shear to the cellulose raw material to make it finer. In order to prevent a decrease in the crystallinity of the fine cellulose due to the fineness, shearing in a liquid is preferable. For example, a method in which fibrillation is highly promoted by a beater such as a beater or a disc refiner (double disc refiner) in a fibrillation solvent, and then subjected to a fine treatment by a high-pressure homogenizer, an ultra-high-pressure homogenizer, a grinder, or the like. And a method of performing fibrillation by a method other than strong mechanical fibrillation such as pulverization (TEMPO oxidation, chemical modification of cellulose hydroxyl group in an organic solvent, etc.).

水 As the fibrillation solvent, water, aprotic solvent and the like are useful. When a fibrillation solvent containing an aprotic solvent is impregnated into a cellulose raw material (preferably a cellulose raw material having a cellulose purity of 80% by mass or more), the cellulose swells in a short time. In this state, a finer treatment can be performed by applying shear energy. Compared to refinement treatment with water solvent, refinement with aprotic solvent is simpler in process because it can be defibrated with low energy and chemical modification can be performed simultaneously with or after defibration. Is more preferable.

Examples of the aprotic solvent include alkyl sulfoxides, alkyl amides, and pyrrolidones. These solvents can be used alone or in combination of two or more.

Examples of the alkyl sulfoxides include, for example, di C 1-4 alkyl sulfoxides such as dimethyl sulfoxide (DMSO), methyl ethyl sulfoxide, and diethyl sulfoxide.

Examples of the alkylamides include N, N-diC1-4alkylformamides such as N, N-dimethylformamide (DMF) and N, N-diethylformamide; N, N-dimethylacetamide (DMAc), N, N N, N-diC1-4alkylacetamides such as -diethylacetamide and the like.

Examples of pyrrolidones include, for example, pyrrolidone such as 2-pyrrolidone and 3-pyrrolidone; and N-C1-4 alkylpyrrolidone such as N-methyl-2-pyrrolidone (NMP).

These aprotic solvents can be used alone or in combination of two or more. Among these aprotic solvents (the number in parentheses is the number of donors), DMSO (29.8), DMF (26.6), DMAc (27.8), NMP (27.3) and the like, particularly DMSO If is used, fine cellulose having a high thermal decomposition initiation temperature can be produced more efficiently. The mechanism of this action is not necessarily clear, but is presumed to be due to the homogeneous micro-swelling of the cellulose raw material in the aprotic solvent.

As a method of applying agitation or shearing energy, for example, a device to which impact shear is applied such as a planetary ball mill and a bead mill, a device to which a rotary shear field which induces fibrillation of cellulose such as a disc refiner and a grinder is added, or various kneaders and The kneading, stirring, and dispersing functions, such as a planetary mixer, can be obtained by using an apparatus capable of performing the functions with high efficiency. More specifically, a disintegrator, a beater, a refiner, a low-pressure homogenizer, a high-pressure homogenizer, an ultra-high-pressure homogenizer, a homomixer, a grinder, a mass colloider, a cutter mill, a ball mill, a jet mill, a single-screw extruder, a twin-screw extruder, Examples thereof include an ultrasonic stirrer and a household juicer mixer.

Cellulose whiskers can be obtained with high efficiency by hydrolyzing cellulose raw materials and dissolving the amorphous part of cellulose.

方法 The method of hydrolysis is not particularly limited, and examples thereof include acid hydrolysis, alkali oxidative decomposition, hydrothermal decomposition, steam explosion, and microwave decomposition. These methods may be used alone or in combination of two or more. In the method of acid hydrolysis, for example, a suitable amount of protonic acid, carboxylic acid, Lewis acid, heteropoly acid, etc. is added in a state where a cellulose raw material is dispersed in an aqueous medium, and the mixture is heated with stirring to easily perform average polymerization. You can control the degree. The reaction conditions such as temperature, pressure, and time vary depending on the type of cellulose, the concentration of cellulose, the type of acid, and the concentration of acid, but are appropriately adjusted so as to achieve the desired average polymerization degree. For example, there is a condition that the cellulose is treated at 100 ° C. or more and under pressure for 10 minutes or more using a 2% by mass or less aqueous mineral acid solution. Under these conditions, a catalyst component such as an acid penetrates into the inside of the cellulose, hydrolysis is promoted, the amount of the catalyst component used is reduced, and subsequent purification is also facilitated. In addition, the dispersion of the cellulose raw material at the time of hydrolysis may contain a small amount of an organic solvent in addition to water as long as the effects of the present invention are not impaired.

The method for chemically modifying the fine cellulose is not particularly limited.For example, a method of adding a chemical modifier at the same time as miniaturization, and performing a chemical modification at the same time as the miniaturization, or adding a chemical modifier after the miniaturization is performed. A method of separately performing chemical modification by a chemical method, or a method of performing fine modification after chemically modifying a cellulose raw material. The solvent used in the chemical modification is not particularly limited. In particular, when an aprotic solvent is used, the cellulose quickly swells into the microfibril gap of cellulose, swells the cellulose, and the microfibrils enter a finely fibrillated state. By performing the chemical modification after creating this state, the chemical modification proceeds uniformly throughout the fine cellulose, and as a result, the variation in the degree of modification is reduced, and high heat resistance can be obtained.

化合物 As the chemical modifier, a compound which reacts with the hydroxyl group of cellulose can be used, and examples thereof include an esterifying agent, an etherifying agent, and a silylating agent. Particularly, an esterifying agent is preferable from the viewpoint of improving heat resistance. As the esterifying agent, an acid halide, an acid anhydride and a vinyl carboxylate are preferred.

The acid halide may be at least one selected from the group consisting of compounds represented by the following formula (1).
R1-C (= O) -X (1)
(Wherein, R1 represents an alkyl group having 1 to 24 carbon atoms, an alkylene group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, or an aryl group having 6 to 24 carbon atoms, X is Cl, Br or I.)
Specific examples of acid halides include acetyl chloride, acetyl bromide, acetyl iodide, propionyl chloride, propionyl bromide, propionyl iodide, butyryl chloride, butyryl bromide, butyryl iodide, benzoyl chloride, benzoyl bromide, iodine But not limited thereto. Above all, acid chlorides can be suitably employed from the viewpoint of reactivity and handleability. In the reaction of the acid halide, one or more alkaline compounds may be added for the purpose of neutralizing the acidic substance which is a by-product while acting as a catalyst. Specific examples of the alkaline compound include, but are not limited to, tertiary amine compounds such as triethylamine and trimethylamine; and nitrogen-containing aromatic compounds such as pyridine and dimethylaminopyridine.

As the acid anhydride, any appropriate acid anhydrides can be used. For example, saturated aliphatic monocarboxylic anhydrides such as acetic acid, propionic acid, (iso) butyric acid, and valeric acid; unsaturated aliphatic monocarboxylic anhydrides such as (meth) acrylic acid and oleic acid; cyclohexanecarboxylic acid, tetrahydro Alicyclic monocarboxylic acid anhydrides such as benzoic acid; aromatic monocarboxylic acid anhydrides such as benzoic acid and 4-methylbenzoic acid; dibasic carboxylic acid anhydrides such as succinic anhydride and adipic acid; Unsaturated aliphatic dicarboxylic anhydrides such as saturated aliphatic dicarboxylic acid, maleic anhydride and itaconic anhydride; 1-cyclohexene-1,2-dicarboxylic anhydride; hexahydrophthalic anhydride; methyltetrahydrophthalic anhydride; Alicyclic dicarboxylic anhydride and aromatic dicarboxylic anhydride such as phthalic anhydride and naphthalic anhydride; 3 bases or more The nucleotide carboxylic acid anhydrides, for example, trimellitic acid, (anhydrous) polycarboxylic acids such as pyromellitic anhydride. In the reaction of the acid anhydride, one or more acidic compounds such as sulfuric acid, hydrochloric acid, and phosphoric acid, or Lewis acids such as metal chlorides and metal triflates, or alkaline compounds such as triethylamine and pyridine are used as catalysts. It may be added.

As the carboxylic acid vinyl ester, the following formula (2):
R-COO-CH = CH ₂ Formula (2)
In the formula, R is an alkyl group having 1 to 24 carbon atoms, an alkylene group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, or an aryl group having 6 to 24 carbon atoms. Vinyl carboxylate represented by｝ is preferred. Vinyl carboxylate includes vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl cyclohexanecarboxylate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, pivalin More preferably, it is at least one selected from the group consisting of vinyl acrylate, vinyl octylate divinyl adipate, vinyl methacrylate, vinyl crotonate, vinyl pivalate, vinyl octylate, vinyl benzoate, and vinyl cinnamate. . In the esterification reaction with a vinyl carboxylate, a catalyst such as an alkali metal hydroxide, an alkaline earth metal hydroxide, a primary to tertiary amine, a quaternary ammonium salt, imidazole and its derivatives, pyridine and its derivatives, and an alkoxide Or one or more selected from the group consisting of:

Examples of the alkali metal hydroxide and alkaline earth metal hydroxide include sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide and the like.

The primary to tertiary amines are primary amines, secondary amines, and tertiary amines, and specific examples include ethylenediamine, diethylamine, proline, N, N, N ', N'-tetramethylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-propanediamine, N, N, N ′, N′-tetramethyl-1,6-hexanediamine, tris (3-dimethylaminopropyl) amine, N, N-dimethylcyclohexylamine, triethylamine and the like can be mentioned.

Examples of imidazole and its derivatives include 1-methylimidazole, 3-aminopropylimidazole, carbonyldiimidazole and the like.

Examples of pyridine and derivatives thereof include N, N-dimethyl-4-aminopyridine, picoline and the like.

Examples of the alkoxide include sodium methoxide, sodium ethoxide, potassium-t-butoxide and the like.

Among these esterifying agents, in particular, acetic anhydride, propionic anhydride, butyric anhydride, vinyl acetate, vinyl propionate, and at least one selected from the group consisting of vinyl butyrate, among them, acetic anhydride and vinyl acetate, the reaction efficiency of Preferred from a viewpoint.

In the reflection type infrared absorption spectrum of the chemically modified fine cellulose, the peak position of the absorption band changes depending on the type of the chemically modified group. From the change in the peak position, it can be determined what absorption band the peak is based on, and the modifying group can be identified. The modification ratio can be calculated from the peak intensity ratio between the peak derived from the modifying group and the peak derived from the cellulose skeleton.
For example, when the modifying group is an acyl group, the peak of the absorption band of C ＝ O based on the acyl group appears at 1730 cm −1, and the peak of the absorption band of CO based on the cellulose backbone appears at 1030 cm −1. (See FIG. 5).

Ratio of peak intensity (peak height of C = O absorption band based on acyl group) of peak intensity of absorption band based on chemical modifying group to peak intensity (height) of absorption band of CO based on cellulose backbone (chemical modification) The degree of modification (modification ratio) (IR index 1030) defined by the peak height of the absorption band based on the group / the peak height of the absorption band of the cellulose backbone C—O) is preferably 0.0024 or more, and 0.1. 50 or less. When the IR index 1030 is 0.0024 or more, a resin composition containing chemically modified fine cellulose having a high thermal decomposition onset temperature can be obtained. On the other hand, when it is 0.50 or less, since the unmodified cellulose skeleton remains in the chemically modified fine cellulose, it has both high tensile breaking strength and dimensional stability derived from cellulose and high thermal decomposition initiation temperature derived from chemical modification. A resin composition containing chemically modified fine cellulose can be obtained. The IR index 1030 is more preferably 0.012 or more, further preferably 0.024 or more, still more preferably 0.048 or more, particularly preferably 0.72 or more, and most preferably 0.1 or more, and more preferably It is 0.44 or less, more preferably 0.37 or less, particularly preferably 0.30 or less, and most preferably 0.25 or less.

Reading of the peak heights of 1730 cm ^-1 and 1030 cm ^-1 used to calculate the IR index 1730 and IR index 1030 is carried out as follows. The peak intensity of 1730 cm ^-1, drawing a base line which connects a straight line other peak is not located near 1550 cm ^-1 and near 1850 cm ^-1, a peak of 1730 cm ^-1 to the height of the baseline in 1730 cm ^-1 The value subtracted from the height shall be read.
The peak intensity of 1030 cm ^-1, drawing a base line which connects a straight line other peaks is no position near 820 cm ^-1 and near 1530 cm ^-1, a peak of 1030 cm ^-1 to the height of the baseline in 1030 cm ^-1 The value subtracted from the height shall be read.

The IR index 1030 can be converted into the average degree of substitution of hydroxyl groups of chemically modified fine cellulose (the average number of substituted hydroxyl groups per glucose, which is a basic structural unit of cellulose, sometimes referred to as DS) according to the following formula.
DS = 4.13 × IR index 1030
The average degree of substitution is preferably from 0.01 to 2.0. When DS is 0.01 or more, a resin composite containing chemically modified fine cellulose having a high thermal decomposition initiation temperature can be obtained. On the other hand, when the molecular weight is 2.0 or less, the unmodified cellulose skeleton remains in the chemically modified fine cellulose, and therefore, a chemical having both high tensile strength and dimensional stability derived from cellulose and high thermal decomposition initiation temperature derived from the chemical modification. A resin composite containing the modified fine cellulose can be obtained. DS is more preferably 0.05 or more, further preferably 0.1 or more, particularly preferably 0.2 or more, most preferably 0.3 or more, more preferably 1.8 or less, and still more preferably 1. 5 or less, particularly preferably 1.2 or less, most preferably 1.0 or less.

The fine cellulose or the chemically modified fine cellulose is washed and concentrated by filtration or centrifugation using water, and finally can be used as a water slurry or a dried product for producing composite particles.

<Thermoplastic resin>
The thermoplastic resin that can be used for the composite particles of the present embodiment will be described in detail.
Specific examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene and ethylene-propylene copolymer; vinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride; polyvinyl acetate and ethylene-vinyl acetate copolymer. , A vinyl resin such as polyvinyl alcohol; a polyacetal resin; a fluororesin such as polyvinylidene fluoride; a polyester resin such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polystyrene, styrene-butadiene block copolymer, styrene-isoprene Polystyrene resins such as block copolymers; Nitrile resins such as polyacrylonitrile, styrene-acrylonitrile copolymer, ABS resin; polyphenylene ether resins; polyamides; Polyimide; Polyamide imide; Acrylic resin such as polymethacrylic acid and polyacrylic acid; Polycarbonate; Polyphenylene sulfide; Polysulfone; Polyether sulfone; Polyether nitrile; Polyether ketone; Polyketone; Liquid crystal polymer; Silicone resin; Natural celluloses such as wood pulp and cotton; regenerated celluloses such as viscose rayon, cuprammonium rayon and Tencel); cellulose derivatives such as nitrocellulose and cellulose acetate; thermoplastic elastomers (eg, ethylene-propylene copolymer (EPR); Olefin-based elastomers such as ethylene-propylene-diene copolymer (EPDM); Styrene-based elastomers such as SBR comprising a copolymer of styrene and butadiene -Silicon-based elastomer; Nitrile-based elastomer; Butadiene-based elastomer; Urethane-based elastomer; Nylon-based elastomer; Ester-based elastomer; Fluorine-based elastomer; and reactive sites (double bond, carboxyl anhydride group, etc.) introduced into those elastomers Modified products); and mixtures of two or more of these.

In a preferred embodiment, the thermoplastic is soluble in DMSO. In the present disclosure, being soluble in DMSO means that 0.1 g or more is dissolved in 100 g of DMSO at 25 ° C. Thermoplastic resins that are soluble in DMSO contribute to increasing the viscosities η ₁₀ and η ₁₀₀ of the present disclosure. Examples of the thermoplastic resin soluble in DMSO include a cellulose derivative (particularly, a cellulose ester), a polystyrene resin, and a vinyl chloride resin. The thermoplastic resin dissolves more preferably in an amount of 0.5 g or more, further preferably 1.0 g or more, particularly preferably 2.0 g or more, in 100 g of DMSO at 25 ° C. It is preferable that the solubility of the thermoplastic resin in DMSO is large, but from the viewpoint of improving the mechanical strength of the resin composition, the thermoplastic resin is 100 g or less of DMSO at 25 ° C., for example, 100 g or less, or 70 g or less, or Dissolve in an amount of 50 g or less.

Among them, the cellulose derivative has a high affinity for fine cellulose because it is a cellulosic material, and also because it is a thermoplastic resin, it can contribute to stabilizing the dispersion of fine cellulose in the resin composition. Therefore, it is more preferable as the thermoplastic resin used for the composite particles. In one embodiment, the mechanical properties of the resin composition are improved by improving and controlling the dispersion state of the fine cellulose in the base resin in the resin composition due to the presence of the cellulose derivative. Further, in one aspect, the presence of the cellulose derivative can have a property that the fine cellulose is soluble and redispersible in the thermoplastic resin.

微細 In the case of fine cellulose in which cellulose is refined to the nanometer level, the surface area of cellulose is significantly increased so that interaction between the surfaces of cellulose is caused by hydrogen bonding. When the fine cellulose is dried and powdered, extremely strong drying shrinkage occurs, and the shrinking structure is irreversible. In addition, since the hydrophilic properties of cellulose are remarkably exhibited in fine cellulose, the fine cellulose is strongly aggregated in a different medium such as a base resin. When the cellulose derivative is present, the fine cellulose can be redispersed even in a dry state, so that the fine cellulose can be redispersed in the resin under melt-kneading with the base resin. Fine cellulose, which is highly dispersed in the resin, improves various mechanical properties of the resin composition.

Considering the production process of a composite material containing a filler and a resin, it is extremely significant that the composite particles as a filler are in a dry state. However, conventionally, particularly, fine cellulose having a nanometer size (ie, less than 1 μm) has to be recycled. It was difficult to obtain a dried product that can be dispersed. In the composite particles according to one embodiment of the present disclosure, the cellulose derivative interacts with the surface of the fine cellulose, and can also function as a binder showing an affinity for the base resin. Redistribution is feasible. In particular, the fact that the surface of the fine cellulose is chemically modified is effective for strengthening the interaction between the cellulose derivative and the fine cellulose.

において In one embodiment, the cellulose derivative is bound to the surface of the fine cellulose.

Cellulose derivatives are preferably cellulose acetate, cellulose acetate propionate, cellulose esters such as cellulose acetate butyrate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, cellulose ethers such as cyanoethyl cellulose, and hydroxypropyl. Cellulose ether esters such as methylcellulose acetate and hydroxypropylmethylcellulose acetate succinate (in the present disclosure, cellulose ether esters are intended to be included in the concept of both cellulose ethers and cellulose esters). At least one type. Among them, cellulose ester is excellent in terms of heat resistance and is preferred. The cellulose derivative is preferably soluble in a solvent used for defibrating cellulose. The cellulose derivative preferably has a melting point between 100 ° C. and 350 ° C. from the viewpoint of miscibility with the resin. Among them, cellulose derivatives having two or more substituents in one derivative, such as cellulose acetate propionate and cellulose acetate butyrate, often have a melting point, and are more preferable.

The weight average molecular weight (Mw) of the cellulose derivative is preferably 1,000 or more, or 5,000 or more, or 10,000 or more, or 20,000 or more, preferably 100,000 or less, or 80,000 or less, or 60,000 or less. is there. Mw is a value measured by a method of calculating in terms of standard polystyrene by size exclusion chromatography.

アルキル The alkyl substituent of the cellulose ether is preferably an alkyl group having 1 to 18 carbon atoms. One or more ether substituents per anhydroglucose unit (ie, mixed esters) may be used. Preferred examples of the ether substituent are a methyl group, an ethyl group, and a propyl group. The ether substituent is preferably an ethyl group in view of moldability, transparency and flexural modulus of the resin composition.

The total degree of substitution of the cellulose ether (the sum of the degree of methyl group substitution and the degree of ethyl group substitution in the case of a co-substituted product such as cellulose methyl ethyl ether) is preferably 1 from the viewpoint of compatibility between the resin and the fine cellulose. It is from 2.5 to 3.0, more preferably from 2.1 to 2.95, even more preferably from 2.6 to 2.90.
The degree of ether substitution is a value measured by ¹ H-NMR (nuclear magnetic resonance apparatus).

The following range is preferable for the degree of polymerization of the cellulose ether, using the viscosity as an index. That is, the viscosity of a solution obtained by dissolving 5 parts by mass of cellulose ether in a mixed solvent of 80 parts by mass of toluene and 20 parts by mass of ethanol has a lower limit of 1 mPa · s or more under a temperature condition of 25 ° C. It is preferably at least 3 mPa · s, more preferably at least 5 mPa · s, even more preferably at least 8 mPa · s, particularly preferably at least 12 mPa · s, most preferably at least 20 mPa · s. Further, the upper limit of the degree of polymerization is preferably 500 mPa · s or less, more preferably 350 mPa · s or less, further preferably 250 mPa · s or less, further preferably 110 mPa · s or less, particularly preferably 70 mPa · s or less, and 55 mPa · s or less. s or less are most preferred. The degree of polymerization of the cellulose ethers, by inhibiting aggregation of the fine cellulose in the composite particles (which are reflected in the dispersion viscosity eta ₁₀ of the composite particles is a high value), the fine cellulose in the resin composition In order to finely disperse the resin composition and improve the transparency and flexural modulus of the resin composition, it is preferably not less than the lower limit, and the fineness is increased by increasing the binding point at the interface between the fine cellulose and the cellulose derivative. From the viewpoint of improving the dispersion stability of cellulose, the content is preferably not more than the above upper limit.

The cellulose ether may be a commercially available product, or a product obtained by adjusting the degree of substitution of the commercially available product to a desired range. Commercially available products include, for example, those available from The Dow Chemical Company under the name ETHOCEL ™. ETHOCEL (TM) Standard @ 4, ETHOCEL (TM) Standard # 7, ETHOCEL (TM) Standard @ 10, ETHOCEL (TM) Standard @ 20, ETHOCEL (TM) Standard @ 45, or ETHOCyl @ Shd @ rd @ Shd. Have been.

エステル The ester substituent of the cellulose ester is preferably an acyl group having 1 to 18 carbon atoms. One or more ester substituents per anhydroglucose unit (ie, mixed esters) may be used. Preferred examples of ester substituents are acetyl, propionyl, and butyryl. The ester substituent is preferably an acetyl group from the viewpoint of moldability and flexural modulus of the resin composition.

The cellulose ester has a degree of polymerization of 50 to 1000, and preferably has a total degree of substitution (ester substitution of 1.5 to 2.6. The degree of polymerization of the cellulose ester is such that the aggregation of fine cellulose in the composite particles is suppressed. (which is being reflected in the dispersion viscosity eta ₁₀ of the composite particles is a high value) the transparency and flexural modulus of the resin composition favorably by finely dispersing the fine cellulose in the resin composition Is preferably 80 or more, more preferably 100 or more, and from the viewpoint of improving the dispersion stability of the fine cellulose by increasing the binding point at the interface between the fine cellulose and the cellulose derivative, It is 700 or less, more preferably 500 or less.

The average degree of polymerization of the cellulose ester can be measured by the limiting viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, Journal of the Fiber Society, Vol. 18, No. 1, pp. 105-120, 1962). The solvent can be selected according to the degree of substitution of the cellulose ester. For example, a cellulose ester is dissolved in a mixed solvent of methylene chloride / methanol = 9/1 (mass ratio) to prepare a solution having a predetermined concentration c (2.00 g / L), and the solution is injected into an Ostwald viscometer. At 25 ° C., the time t (second) for the solution to pass between the marking lines of the viscometer is measured. On the other hand, also for the mixed solvent alone, the passage time to (second) is measured in the same manner as described above, and the viscosity average polymerization degree can be calculated according to the following formulas (3) to (5).
ηrel = t / to (3)
[Η] = (lnηrel) / c (4)
DP = [η] / (6 × 10−4) (5)
(Where t is the transit time of the solution (seconds), to is the transit time of the solvent (seconds), c is the cellulose ester concentration of the solution (g / L), ηrel is the relative viscosity, [η] is the intrinsic viscosity, DP Indicates the average degree of polymerization)

The total degree of substitution of the cellulose ester (for example, in the case of a co-substituted product such as cellulose acetate butyrate, the sum of the degree of acetyl group substitution and the degree of butyryl group substitution) is preferably from the viewpoint of compatibility between the resin and the fine cellulose. Is from 1.5 to 3.0, more preferably from 2.1 to 2.95, even more preferably from 2.6 to 2.90. By setting the total substitution degree within the above range, the affinity between the resin and the fine cellulose can be increased, and the effect of improving the dispersion stability becomes good.
The degree of ester substitution is a value measured by ¹ H-NMR (nuclear magnetic resonance apparatus).

The cellulose ester may be a commercially available product, or a product obtained by adjusting the total substitution degree of the commercially available product to a desired range. Commercially available products include cellulose diacetate (manufactured by Daicel, product names: L-30 and L-70), cellulose triacetate (manufactured by Daicel, product name: LT-105), and cellulose acetate propionate (Eastman Chemical Co., Ltd.) And product name: CAP504-2.0), cellulose acetate butyrate (manufactured by Eastman Chemical Company, product name: CAB321-0.1), and the like.

The combination of the cellulose derivative and the chemical modification in the fine cellulose is preferably a combination in which the cellulose derivative has at least an acetyl substituent and the chemical modification is acetylation, and more preferably, the cellulose derivative is a cellulose diacetate ( DAC), cellulose triacetate (TAC), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP), and the chemical modification is acetylation. When the cellulose derivative and the fine cellulose have similar ester substituents, the hydrophobicity and affinity of the cellulose derivative and the fine cellulose tend to be good, and the fine dispersion of the fine cellulose in the resin composition is good. It is preferred in terms of.

The ratio of the fine cellulose to 100% by mass of the composite particles is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, particularly preferably 15% by mass, from the viewpoint of obtaining a good effect as a filler. At least 20% by mass, most preferably at least 20% by mass, and preferably at most 90% by mass, more preferably at most 90% by mass, from the viewpoint of obtaining an excellent dispersion improving effect of fine cellulose by using a thermoplastic resin (in one embodiment, a cellulose derivative). It is at most 85% by mass, more preferably at most 80% by mass.

The lower limit of the ratio of the thermoplastic resin (in one aspect, a cellulose derivative) in the composite particles is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably from the viewpoint of obtaining a good dispersion improving effect of fine cellulose. Is not less than 20% by mass, and the upper limit is preferably not more than 90% by mass, more preferably not more than 85% by mass, and still more preferably not more than 80% by mass, from the viewpoint of obtaining a good filler action by using fine cellulose.

The lower limit of the amount of the cellulose derivative per 100 parts by mass of fine cellulose (fine cellulose fibers in one embodiment) is preferably 1 part by mass or more, or 5 parts by mass or more, or 10 parts by mass or more, or 20 parts by mass or more, The upper limit is preferably 500 parts by mass or less, or 300 parts by mass or less, or 200 parts by mass or less. From the viewpoint of improving the tensile rupture strength and thermal stability of the resin composition and reducing the variation in performance, it is desirable that the amount of fine cellulose (fine cellulose fiber in one embodiment) be within the above range.

The ratio (by mass) of fine cellulose / cellulose derivative in the composite particles is preferably 10/90 to 90/10, more preferably 15/85 to 85/15, and still more preferably 20/80 to 80/20. .

≫Production of composite particles≪
The method for producing the composite particles is not particularly limited, and examples thereof include the following methods. According to these methods, the composite particles can be collected as a slurry or a dried product.
(1) An aqueous dispersion (slurry) of fine cellulose (fine cellulose fibers in one embodiment) and thermoplastic resin particles (cellulose derivative powder in one embodiment) are mixed, and then optionally dried (ie, powdered), A method for recovering composite particles.
(2) A thermoplastic resin is added to an organic solvent dispersion of fine cellulose (fine cellulose fiber in one embodiment) to disperse the fine cellulose and dissolve the thermoplastic resin (cellulose derivative in one embodiment). Obtaining an organic solvent dispersion (fine cellulose / resin dispersion).
This organic solvent dispersion is mixed with a poor solvent for a thermoplastic resin (in one embodiment, a cellulose derivative) to precipitate the thermoplastic resin (that is, to deposit composite particles containing fine cellulose and the thermoplastic resin), thereby dispersing the composite particles. The process of obtaining the body,
Optionally, a purification step of replacing the organic solvent of the composite particle dispersion with water, and optionally, a step of separating and collecting the composite particles by filtration, centrifugation, etc., washing with pure water, and / or drying,
A method that includes
(3) After adding and dissolving a thermoplastic resin (in one aspect, a cellulose derivative) in the process of producing fine cellulose (in one aspect, fine cellulose fibers), after the production of the fine cellulose is completed, the same as in the method (2) above A method for performing the steps after the precipitation step.

Fine cellulose can be preferably prepared by a defibration step of performing a defibration treatment of cellulose in an organic solvent to obtain a fine cellulose dispersion, and optionally a purification step of replacing the organic solvent in the fine cellulose dispersion with water. . The addition of the thermoplastic resin in the method (3) may be performed before or during defibration.

化学 In the case where the fine cellulose is chemically modified, it is preferable to provide a chemical modification step for chemically modifying the fine cellulose at the same time as or after the fibrillation step (preferably, before the purification step).

The organic solvent in which the thermoplastic resin (in one embodiment, a cellulose derivative) dissolves is not particularly limited, but may be a halogenated hydrocarbon, an ester, a ketone, an ether, an alcohol, an alkylsulfoxide, an alkylamide, or a pyrrolidone. Are preferred. The solvent may be a single type of compound or a mixed solvent obtained by mixing a plurality of compounds. Specifically, halogenated hydrocarbons (eg, dichloromethane, etc.), esters (eg, methyl acetate, methyl formate, ethyl acetate, amyl acetate, butyl acetate, etc.), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, etc.) ), Ethers (eg, dioxane, dioxolan, tetrahydrofuran, diethyl ether, methyl-t-butyl ether, etc.), alcohols (eg, methanol, ethanol, hexafluoroisopropanol, resorcinol, etc.), aprotic solvents described above in the present disclosure (Alkylsulfoxides, alkylamides, pyrrolidones) and the like.
Among them, the above-mentioned aprotic solvents are also excellent in producing fine cellulose. It is preferable in terms of process efficiency to continuously perform the production of fine cellulose and the production of composite particles using an aprotic solvent. In particular, when the thermoplastic resin is a cellulose derivative, it is preferable to use DMSO because the swellability of the cellulose raw material is extremely excellent and the solubility of the cellulose derivative is also excellent.

貧 A poor solvent for a thermoplastic resin is a solvent that does not dissolve the thermoplastic resin. More preferably, it is a solvent that does not dissolve the thermoplastic resin and is miscible with the organic solvent in which the thermoplastic resin dissolves. Examples of the poor solvent for the thermoplastic resin (in one embodiment, a cellulose derivative) include water having a pH of 1 to 14, water containing an inorganic salt (eg, sodium chloride, calcium chloride, sodium silicate, etc.), and alcohol (eg, methanol, ethanol, and the like). Isopropanol, 1-hexanol, etc.), and a mixed solvent of water / alcohol.

解 In the case where the fibrillation and / or chemical modification of the cellulose raw material and the addition of the cellulose derivative are performed simultaneously or continuously in an organic solvent, it is preferable to use DMSO, DMF, DMAc, NMP, etc., particularly, DMSO. In this case, fine cellulose having a high thermal decomposition initiation temperature can be produced more efficiently. The mechanism of this action is not necessarily clear, but is presumed to be due to the homogeneous micro-swelling of the cellulose raw material in the aprotic solvent.

The method of stirring or shearing necessary to promote the compositing of the fine cellulose and the cellulose derivative is not particularly limited, but, for example, a device to which collision shear is applied such as a planetary ball mill and a bead mill, a disc refiner A device capable of performing kneading, stirring, and dispersing functions with high efficiency can be used, such as a device that adds a rotary shear field that induces fibrillation of cellulose, such as a grinder, and a grinder, or various kneaders and a planetary mixer. .

The proportion of water in the composite particles is preferably not more than 95% by mass, more preferably 0.01 to 95% by mass, still more preferably 0.1 to 50% by mass, particularly preferably 0 to 50% by mass, based on the total amount of the composite particles. It can be controlled to 1 to 20% by mass, most preferably 0.1 to 10% by mass. The drying operation may be appropriately performed in a constant temperature chamber or the like so that the proportion of water in the composite particles falls within a desired range.

Conventionally, the process of concentrating a slurry of fine cellulose requires a very long time due to clogging when, for example, a filtration operation is used. Therefore, the productivity when performing washing multiple times was remarkably low. However, the above production methods ((2) and (3)) in which washing and concentration are performed after precipitation using a poor solvent for the thermoplastic resin are performed, because the fine cellulose and the thermoplastic resin are both precipitated, and the Is greatly improved, and the time for the concentration step can be significantly reduced, while the washing efficiency is equal to or higher than the conventional one.

≪Resin composition≫
One embodiment of the present invention provides a resin composition (resin composite) including the above-described composite particles and a base resin. As the base resin, a thermoplastic resin, a thermosetting resin, a photocurable resin, rubber, or the like can be used. In a typical embodiment, the thermoplastic resin derived from the composite particles forms a matrix together with the base resin (preferably by mixing the thermoplastic resin and the base resin) in the resin composition, and the fine cellulose is contained in the matrix. Are finely dispersed. In one embodiment in which the base resin is a thermoplastic resin, the base resin is a resin different from the thermoplastic resin contained in the composite particles. In the present disclosure, “different resins” means resins having different component compositions and / or molecular structures (for example, molecular weights) of the resins.

の一 One embodiment of the present invention also provides a resin composition containing a thermoplastic resin (as a base resin), fine cellulose having a fiber diameter of 2 nm or more and less than 1000 nm, and a cellulose derivative. Specific embodiments include a thermoplastic resin (as a base resin), 0.1 to 40 parts by mass per 100 parts by mass of the thermoplastic resin, fine cellulose having a fiber diameter of 2 nm or more and less than 1000 nm, and fine cellulose 100 Provided is a resin composition containing 1 to 900 parts by mass of a cellulose derivative with respect to parts by mass.

<Base resin>
[Thermoplastic resin]
Specific examples of the thermoplastic resin include, but are not particularly limited to, for example, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyvinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride; Vinyl resins such as polyvinyl acetate, ethylene-vinyl acetate copolymer and polyvinyl alcohol; polyacetal resins; fluororesins such as polyvinylidene fluoride; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Polystyrene resins such as styrene-butadiene block copolymer and styrene-isoprene block copolymer; nitrile resins such as polyacrylonitrile, styrene-acrylonitrile copolymer and ABS resin; polyphenylene Acrylic resins such as polymethacrylic acid and polyacrylic acid; polycarbonate; polyphenylene sulfide; polysulfone; polyether sulfone; polyether nitrile; polyether ketone; polyketone; liquid crystal polymer; Resin; ionomer; cellulose (natural cellulose such as wood pulp and cotton; regenerated cellulose such as viscose rayon, cuprammonium rayon and Tencel); and cellulose derivatives such as nitrocellulose. These thermoplastic resins may be used alone or as a blend of two or more. The blending ratio when blending may be appropriately selected according to various uses.

Among the thermoplastic resins, a crystalline resin having a melting point in the range of 100 ° C. to 350 ° C. or an amorphous resin having a glass transition temperature in the range of 100 to 250 ° C., for example, a polyolefin resin, a polyamide resin , Polyester-based resin, polyacetal-based resin, polyphenylene ether-based resin, polyphenylene sulfide-based resin and a mixture of two or more thereof, preferably polyolefin-based resin, polyamide-based resin, polyester from the viewpoint of handleability and cost Resins, polyacetal resins and the like. From the viewpoint of increasing the heat resistance of the resin composition, the melting point of the thermoplastic resin (particularly, the crystalline resin) is preferably 140 ° C or higher, or 150 ° C or higher, or 160 ° C or higher, or 170 ° C or higher, or 180 ° C or higher. Or at least 190 ° C, or at least 200 ° C, or at least 210 ° C, at least 220 ° C, or at least 230 ° C, or at least 240 ° C, or at least 245 ° C, or at least 250 ° C.

The melting point of the crystalline resin as used herein refers to the peak top temperature of an endothermic peak that appears when the temperature is raised from 23 ° C. at a rate of 10 ° C./min using a differential scanning calorimeter (DSC). When two or more endothermic peaks appear, it indicates the peak top temperature of the endothermic peak on the highest temperature side. At this time, the enthalpy of the endothermic peak is preferably at least 10 J / g, more preferably at least 20 J / g. In the measurement, it is preferable to use a sample which is once heated to a temperature condition of not less than the melting point + 20 ° C. to melt the resin, and then cooled to 23 ° C. at a rate of 10 ° C./min.

The glass transition temperature of the amorphous resin as used herein means that the temperature is measured at an applied frequency of 10 Hz using a dynamic viscoelasticity measuring apparatus while increasing the temperature from 23 ° C. at a rate of 2 ° C./min. The temperature at the peak top of the peak at which the storage modulus is greatly reduced and the loss modulus is maximized. When two or more peaks of the loss elastic modulus appear, it indicates the peak top temperature of the highest temperature peak. The measurement frequency at this time is desirably at least once every 20 seconds in order to increase the measurement accuracy. The method of preparing the measurement sample is not particularly limited. From the viewpoint of eliminating the influence of molding distortion, it is preferable to use a cut piece of a hot press molded product, and the size (width and thickness) of the cut piece is as small as possible. Smaller is more desirable from the viewpoint of heat conduction.

ポリ Polyolefin resins that are preferable as thermoplastic resins are polymers obtained by polymerizing olefins (for example, α-olefins) or alkenes as a monomer unit. Specific examples of the polyolefin resin include ethylene (co) polymers exemplified by low-density polyethylene (for example, linear low-density polyethylene), high-density polyethylene, ultra-low-density polyethylene, ultra-high-molecular-weight polyethylene, polypropylene, and ethylene. -Polypropylene (co) polymers exemplified by ethylene-propylene copolymer, ethylene-propylene-diene copolymer, etc., ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer Copolymers of α-olefins such as ethylene typified by coalescence are exemplified.

ポリプロピレン Here, the most preferable polyolefin resin is polypropylene. Particularly, polypropylene having a melt mass flow rate (MFR) of 3 g / 10 min or more and 30 g / 10 min or less measured at 230 ° C. under a load of 21.2 N according to ISO 1133 is preferable. The lower limit of the MFR is more preferably 5 g / 10 minutes, still more preferably 6 g / 10 minutes, and most preferably 8 g / 10 minutes. Further, the upper limit is more preferably 25 g / 10 minutes, still more preferably 20 g / 10 minutes, and most preferably 18 g / 10 minutes. The MFR desirably does not exceed the above upper limit from the viewpoint of improving the toughness of the composition, and desirably does not exceed the above lower limit from the viewpoint of the fluidity of the composition.

酸 Further, in order to increase the affinity with cellulose, an acid-modified polyolefin-based resin can be suitably used. The acid at this time can be appropriately selected from maleic acid, fumaric acid, succinic acid, phthalic acid, anhydrides thereof, and polycarboxylic acids such as citric acid. Among these, maleic acid or its anhydride is preferred because of its high modification rate. The modification method is not particularly limited, but is generally a method of melting and kneading by heating to the melting point or higher in the presence or absence of a peroxide. As the polyolefin resin to be acid-modified, all of the above-mentioned polyolefin resins can be used, but polypropylene is particularly preferably used. The acid-modified polypropylene may be used alone, but it is more preferable to use it in combination with unmodified polypropylene in order to adjust the modification rate of the whole resin. At this time, the ratio of the acid-modified polypropylene to all the polypropylenes is 0.5% by mass to 50% by mass. A more preferred lower limit is 1% by mass, further preferably 2% by mass, still more preferably 3% by mass, particularly preferably 4% by mass, and most preferably 5% by mass. Further, a more preferable upper limit is 45% by mass, further preferably 40% by mass, still more preferably 35% by mass, particularly preferably 30% by mass, and most preferably 20% by mass. In order to maintain the interface strength between the resin and the cellulose, the lower limit is preferably greater than or equal to the lower limit. To maintain the ductility of the resin, the upper limit is preferably equal to or less than the upper limit.

The melt mass flow rate (MFR) of the acid-modified polypropylene measured at 230 ° C. under a load of 21.2 N according to ISO 1133 is preferably 50 g / 10 min or more in order to increase the affinity with the cellulose interface. . A more preferred lower limit is 100 g / 10 minutes, still more preferably 150 g / 10 minutes, and most preferably 200 g / 10 minutes. There is no particular upper limit, but the upper limit is 500 g / 10 minutes from the viewpoint of maintaining the mechanical strength. By setting the MFR within this range, it is possible to enjoy the advantage that the MFR is easily present at the interface between the cellulose and the resin.

Illustrative examples of polyamide resins that are preferable as the thermoplastic resin include polyamide 6, polyamide 11, and polyamide 12 obtained by a polycondensation reaction of lactams, 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, and the like. 1,7-heptanediamine, 2-methyl-1-6-hexanediamine, 1,8-octanediamine, 2-methyl-1,7-heptanediamine, 1,9-nonanediamine, 2-methyl-1,8- Diamines such as octanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, m-xylylenediamine, and butanedioic acid, pentanedioic acid, hexanedioic acid, heptadioic acid Octane diacid, nonane diacid, decane diacid, benzene-1,2-dicarboxylic acid, benzene-1,3-

di Polyamide

6,6,

polyamide

6,10 obtained as a copolymer with dicarboxylic acids such as cyclohexane-1,3-dicarboxylic acid and cyclohexane-1,4-dicarboxylic acid such as rubonic acid and benzene-1,4 dicarboxylic acid , Polyamide 6,11, polyamide 6,12, polyamide 6, T, polyamide 6, I, polyamide 9, T, polyamide 10, T, polyamide 2M5, T, polyamide MXD, 6, polyamide 6, C, polyamide 2M5, C And copolymers obtained by copolymerizing them, for example, copolymers of polyamide 6, T / 6, I, and the like.

Among these polyamide resins, aliphatic polyamides such as polyamide 6, polyamide 11, polyamide 12,

polyamide

6,6,

polyamide

6,10, polyamide 6,11 and polyamide 6,12, polyamide 6, C, polyamide 2M5, C The alicyclic polyamide is more preferable.

末端 The terminal carboxyl group concentration of the polyamide resin is not particularly limited, but the lower limit is preferably 20 µmol / g, and more preferably 30 µmol / g. The upper limit of the terminal carboxyl group concentration is preferably 150 μmol / g, more preferably 100 μmol / g, and still more preferably 80 μmol / g.

において In the polyamide resin, the ratio of the carboxyl terminal group to all terminal groups ([COOH] / [total terminal group]) is more preferably 0.30 to 0.95. The lower limit of the carboxyl end group ratio is more preferably 0.35, even more preferably 0.40, and most preferably 0.45. The upper limit of the carboxyl terminal group ratio is more preferably 0.90, still more preferably 0.85, and most preferably 0.80. The carboxyl terminal group ratio is desirably 0.30 or more from the viewpoint of dispersibility of the fine cellulose in the composition, and desirably 0.95 or less from the viewpoint of the color tone of the obtained composition.

公知 A known method can be used to adjust the terminal group concentration of the polyamide resin. For example, a diamine compound, a monoamine compound, a dicarboxylic acid compound, a monocarboxylic acid compound, an acid anhydride, a monoisocyanate, a monoacid halide, a monoester, a monoalcohol, etc., so as to have a predetermined terminal group concentration during polymerization of polyamide. A method in which a terminal adjuster that reacts with a terminal group is added to the polymerization solution may be used.

Examples of the terminal regulator that reacts with a terminal amino group include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. Aliphatic monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid A carboxylic acid; and a plurality of mixtures arbitrarily selected from these. Among them, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, from the viewpoints of reactivity, sealed terminal stability, and price. And at least one terminal adjuster selected from the group consisting of benzoic acid and benzoic acid, and acetic acid is most preferred.

Examples of a terminal adjuster that reacts with a terminal carboxyl group include aliphatic amines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Monoamines; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, naphthylamine, and any mixtures thereof. Among them, at least one terminal selected from the group consisting of butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline from the viewpoints of reactivity, boiling point, stability of a sealed terminal, and price. Modifiers are preferred.

The concentration of these amino terminal groups and carboxyl terminal groups is preferably determined from the integrated value of the characteristic signal corresponding to each terminal group by ¹ H-NMR from the viewpoint of accuracy and simplicity. As a method for determining the concentrations of these terminal groups, a method described in JP-A-7-228775 is specifically recommended. When this method is used, deuterated trifluoroacetic acid is useful as a measuring solvent. Further, the number of times of integration of ¹ H-NMR requires at least 300 scans even when measured by an instrument having a sufficient resolution. In addition, the concentration of the terminal group can be measured by a titration measurement method as described in JP-A-2003-055549. However, in order to minimize the influence of mixed additives, lubricants, and the like, quantification by ¹ H-NMR is more preferable.

The intrinsic viscosity [η] of the polyamide resin measured in concentrated sulfuric acid at 30 ° C. is preferably 0.6 to 2.0 dL / g, and 0.7 to 1.4 dL / g. Is more preferably 0.7 to 1.2 dL / g, and particularly preferably 0.7 to 1.0 dL / g. Use of the polyamide having an intrinsic viscosity in a preferable range, and particularly preferable range among them, can significantly increase the fluidity in a mold at the time of injection molding of the resin composition, and give an effect of improving the appearance of a molded piece. it can.

In the present disclosure, “intrinsic viscosity” has the same meaning as viscosity generally called intrinsic viscosity. A specific method for obtaining this viscosity is to measure ηsp / c of several measuring solvents having different concentrations in 96% concentrated sulfuric acid under a temperature condition of 30 ° C., and to determine the respective ηsp / c and the concentration (c ) And extrapolating the concentration to zero. The value extrapolated to zero is the intrinsic viscosity.
Details of these are described, for example, in Polymer Process Engineering (Prentice-Hall, Inc. 1994), pages 291 to 294.
At this time, it is desirable from the viewpoint of accuracy that the number of the measurement solvents having different concentrations be at least four. At this time, the recommended concentrations of the different viscosity measurement solutions are preferably at least four points of 0.05 g / dL, 0.1 g / dL, 0.2 g / dL, and 0.4 g / dL.

Preferred polyester resins as thermoplastic resins include polyethylene terephthalate (hereinafter sometimes simply referred to as PET), polybutylene succinate (a polyester resin comprising an aliphatic polyvalent carboxylic acid and an aliphatic polyol (hereinafter referred to as PBS). ), Polybutylene succinate adipate (hereinafter sometimes simply referred to as PBSA), polybutylene adipate terephthalate (hereinafter sometimes simply referred to as PBAT), polyhydroxyalkanoic acid (3-hydroxyalkanoic acid). A polyester resin comprising: PHA; polylactic acid (hereinafter, sometimes simply referred to as PLA); polybutylene terephthalate (hereinafter, sometimes simply referred to as PBT); polyethylene naphthalate (hereinafter, simply referred to as PBT) , May be referred to as PEN), polyarylate (hereinafter sometimes simply referred to as PAR), polycarbonate (hereinafter sometimes simply referred to as PC), or one or more kinds selected therefrom. .

ポリエステル Among these, more preferred polyester-based resins include PET, PBS, PBSA, PBT, and PEN, and more preferably, PBS, PBSA, and PBT.

The end groups of the polyester resin can be freely changed depending on the monomer ratio at the time of polymerization and the presence / absence of the terminal stabilizer, and the amount of the carboxyl end group relative to all end groups of the polyester resin. The ratio ([COOH] / [all terminal groups]) is more preferably 0.30 to 0.95. The lower limit of the carboxyl end group ratio is more preferably 0.35, even more preferably 0.40, and most preferably 0.45. The upper limit of the carboxyl terminal group ratio is more preferably 0.90, still more preferably 0.85, and most preferably 0.80. The carboxyl terminal group ratio is desirably 0.30 or more from the viewpoint of dispersibility of the fine cellulose in the composition, and desirably 0.95 or less from the viewpoint of the color tone of the obtained composition.

Polyacetal resins preferred as thermoplastic resins include homopolyacetals using formaldehyde as a raw material and copolyacetals containing trioxane as a main monomer and 1,3-dioxolane as a comonomer component, and both are usable. However, from the viewpoint of thermal stability during processing, copolyacetal can be preferably used. In particular, the amount of the structure derived from a comonomer component (eg, 1,3-dioxolane) is more preferably in the range of 0.01 to 4 mol%. A preferred lower limit of the amount of the structure derived from the comonomer component is 0.05 mol%, more preferably 0.1 mol%, and even more preferably 0.2 mol%. A preferred upper limit is 3.5 mol%, more preferably 3.0 mol%, still more preferably 2.5 mol%, and most preferably 2.3 mol%.

下限 From the viewpoint of thermal stability during extrusion and molding, the lower limit is preferably within the above range, and the upper limit is preferably within the above range from the viewpoint of mechanical strength.

[Thermosetting resin]
Specific examples of the thermosetting resin are not particularly limited. For example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol E epoxy resin, bisphenol M epoxy resin Epoxy resins such as bisphenol P epoxy resin, bisphenol Z epoxy resin, bisphenol A novolak epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, novolak epoxy resin, biphenyl epoxy resin, biphenyl aralkyl Epoxy resin, arylalkylene epoxy resin, tetraphenylolethane epoxy resin, naphthalene epoxy resin, anthracene epoxy resin, phenoxy epoxy resin Epoxy resin, dicyclopentadiene epoxy resin, norbornene epoxy resin, adamantane epoxy resin, fluorene epoxy resin, glycidyl methacrylate copolymer epoxy resin, copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified Polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4′-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or Diglycidyl ether of propylene glycol, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, triglycidyl Oil-modified resols modified with novolak-type phenol resins such as squirrel (2-hydroxyethyl) isocyanurate, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, unmodified resol phenol resin, tung oil, linseed oil, walnut oil, etc. Phenol resin such as resol type phenol resin such as phenol resin, phenoxy resin, urea (urea) resin, triazine ring-containing resin such as melamine resin, unsaturated polyester resin, bismaleimide resin, diallyl phthalate resin, silicone resin, benzoxazine ring Resin, norbornene resin, cyanate resin, isocyanate resin, urethane resin, benzocyclobutene resin, maleimide resin, bismaleimide triazine resin, polyazomethine resin, thermosetting resin Imide and the like.
These thermosetting resins may be used alone or as a blend of two or more. The blending ratio when blending may be appropriately selected according to various uses.

[Photocurable resin]
Specific examples of the photocurable resin include, but are not particularly limited to, known general (meth) acrylate resins, vinyl resins, and epoxy resins. These are roughly classified into a radical reaction type in which a monomer reacts by radicals generated by light and a cation reaction type in which a monomer cationically polymerizes, according to a reaction mechanism. The radical reaction type monomers include (meth) acrylate compounds, vinyl compounds (for example, certain vinyl ethers), and the like. Epoxy compounds, certain vinyl ethers and the like correspond to the cation reaction type. In addition, for example, an epoxy compound that can be used as a cation reaction type can be a monomer of both a thermosetting resin and a photocurable resin.

(Meth) acrylate compound refers to a compound having one or more (meth) acrylate groups in a molecule. Specific examples of the (meth) acrylate compound include monofunctional (meth) acrylate, polyfunctional (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate.

Examples of the vinyl compound include vinyl ether, styrene and styrene derivatives, and vinyl compounds. Examples of the vinyl ether include ethyl vinyl ether, propyl vinyl ether, hydroxyethyl vinyl ether, and ethylene glycol divinyl ether. Examples of the styrene derivative include methyl styrene and ethyl styrene. Examples of the vinyl compound include triallyl isocyanurate and trialmethallyl isocyanurate.

Furthermore, a so-called reactive oligomer may be used as a raw material of the photocurable resin. As the reactive oligomer, an oligomer having any combination selected from a (meth) acrylate group, an epoxy group, a urethane bond, and an ester bond in the same molecule, for example, a (meth) acrylate group and a urethane bond in the same molecule Urethane acrylate, a polyester acrylate having a (meth) acrylate group and an ester bond in the same molecule, an epoxy acrylate derived from an epoxy resin and having an epoxy group and a (meth) acrylate group in the same molecule, and the like. Can be

(4) The photocurable resin may be used alone, or two or more kinds may be used as a blend. The blending ratio in the case of blending may be appropriately selected according to various uses.

[Elastomer (rubber)]
Specific examples of the elastomer (that is, rubber) are not particularly limited, and include, for example, natural rubber (NR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), isoprene rubber (IR) Butyl rubber (IIR), acrylonitrile-butadiene rubber (NBR), acrylonitrile-styrene-butadiene copolymer rubber, chloroprene rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, isoprene-butadiene copolymer Combined rubber, chlorosulfonated polyethylene rubber, modified natural rubber (epoxidized natural rubber (ENR), hydrogenated natural rubber, deproteinized natural rubber, etc.), ethylene-propylene copolymer rubber, acrylic rubber, epichlorohydrin rubber, polysulfide Rubber, silicone rubber, rubber Containing rubbers, urethane rubbers, and the like. These rubbers may be used alone or as a blend of two or more. The blending ratio when blending may be appropriately selected according to various uses.

[Additive]
The resin composition of the present embodiment may further include an additive as needed in order to improve its performance. The additive is not particularly limited, but includes, for example, a dispersion stabilizer; a fine fiber filler component (eg, fibrillated fiber or fine fiber of aramid fiber) composed of a high heat-resistant organic polymer other than fine cellulose; Agents; polysaccharides such as starches and alginic acid; natural proteins such as gelatin, glue and casein; inorganic compounds such as zeolites, ceramics, talc, silica, metal oxides and metal powders; coloring agents; fragrances; pigments; Leveling agent; conductive agent; antistatic agent; ultraviolet absorber; ultraviolet dispersant; The content ratio of the optional additive in the resin composition is appropriately selected within a range that does not impair the desired effect of the present invention, and is, for example, 0.01 to 50% by mass, or 0.1 to 30% by mass. May be.

(Dispersion stabilizer)
In a preferred embodiment, a dispersion stabilizer having a function of stably dispersing fine cellulose in the resin composition may be used. The dispersion stabilizer can improve the mechanical properties of the resin composition by improving and controlling the dispersion state of the fine cellulose in the resin composition. The dispersion stabilizer can be at least one selected from the group consisting of a surfactant, an organic compound having a boiling point of 160 ° C. or higher, and a resin having a chemical structure capable of highly dispersing fine cellulose.

The lower limit of the mass ratio of the dispersion stabilizer to the total mass of the resin composition is preferably 0.01% by mass or more, or 0%, from the viewpoint of favorably improving the mechanical properties and thermal stability of the resin composition. 0.5% by mass or more, or 0.1% by mass or more, or 0.5% by mass or more, or 1% by mass or more, and the upper limit is in terms of favorably maintaining the desired properties of the base resin in the resin composition. Therefore, it is preferably 20% by mass or less, or 10% by mass or less, or 5% by mass or less, or 3% by mass or less.

The surfactant only needs to have a chemical structure in which a site having a hydrophilic substituent and a site having a hydrophobic substituent are covalently bonded. Can be used. For example, the following can be used alone or in combination of two or more.
As the surfactant, any of an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and a cationic surfactant can be used. In the above, an anionic surfactant and a nonionic surfactant are preferable, and a nonionic surfactant is more preferable.

Among the above, in terms of affinity with cellulose, a surfactant having a polyoxyethylene chain as a hydrophilic group, a carboxylic acid group, or a hydroxyl group is preferable, and a polyoxyethylene-based surfactant having a polyoxyethylene chain as a hydrophilic group. Agents (polyoxyethylene derivatives) are more preferred, and nonionic polyoxyethylene derivatives are even more preferred. The polyoxyethylene chain length of the polyoxyethylene derivative is preferably 3 or more, more preferably 5 or more, still more preferably 10 or more, and particularly preferably 15 or more. The longer the chain length, the higher the affinity for cellulose, but in the balance with coating properties, the upper limit is preferably 60 or less, more preferably 50 or less, still more preferably 40 or less, and particularly preferably 30 or less. Most preferred is 20 or less.

In the above-mentioned surfactants, in particular, as the hydrophobic group, alkyl ether type, alkyl phenyl ether type, rosin ester type, bisphenol A type, β naphthyl type, styrenated phenyl type, and hardened castor oil type, Since it has a high affinity, it can be suitably used. The preferred alkyl chain length (in the case of alkylphenyl, the number of carbon atoms excluding the phenyl group) is preferably 5 or more, more preferably 10 or more, still more preferably 12 or more, and particularly preferably 16 or more. When the base resin is a polyolefin, there is no upper limit because the greater the number of carbon atoms, the higher the affinity with the base resin. However, the upper limit is preferably 30 or less, more preferably 25 or less.

Among these hydrophobic groups, those having a cyclic structure or those having a bulky and multifunctional structure are preferable. Those having a cyclic structure are preferably alkylphenyl ether type, rosin ester type, bisphenol A type, β-naphthyl type, and styrenated phenyl type, and those having a polyfunctional structure are preferably hardened castor oil type.
Among these, the rosin ester type and the hardened castor oil type are particularly preferable.

有機 Although depending on the type of the base resin, an organic compound having a boiling point of 160 ° C. or higher may be effective as a non-surfactant-based dispersion medium in some cases. As a specific example of such an organic compound, for example, when the base resin is a polyolefin-based resin, a high-boiling organic solvent such as liquid paraffin or decalin is effective. When the base resin is a polar resin such as a nylon-based resin and a polyacetate-based resin, it is effective to use a solvent similar to an aprotic solvent that can be used in producing fine cellulose, for example, DMSO. It may be.

The lower limit of the amount of the composite particles relative to 100 parts by mass of the base resin is at least 0.1 part by mass, preferably at least 1 part by mass, more preferably at least 2 parts by mass, even more preferably at least 3 parts by mass, and the upper limit is 100 parts by mass. Parts by mass, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, particularly preferably 50 parts by mass or less. From the viewpoint of the balance between the fluidity of the resin composition at the time of melting and the mechanical properties, it is desirable that the amount of fine cellulose be within the above range.

The lower limit of the mass ratio of the fine cellulose to the total mass of the resin composition is preferably 0.05% by mass or more, or 0. 0 mass% from the viewpoint of favorably improving the mechanical properties and thermal stability of the resin composition. 1% by mass or more, or 1% by mass or more, and the upper limit is preferably 50% by mass or less, or 40% by mass or less, from the viewpoint of favorably maintaining desired properties of the base resin in the resin composition. 30% by mass or less, or 20% by mass or less.

The mass ratio of the base resin (thermoplastic resin in one embodiment) to the total mass of the resin composition is preferably 50 from the viewpoint of exhibiting thermal stability (reduction of linear thermal expansion coefficient and retention of elasticity at high temperatures). % By mass or more, or 60% by mass or more, or 70% by mass or more, or 80% by mass or more, from the viewpoint of imparting functions such as a high elastic modulus and a decrease in thermal expansion coefficient to the resin composition. Is 99.5% by mass or less, or 90% by mass or less.

The amount of fine cellulose (fine cellulose fibers in one embodiment) is preferably 0.1 parts by mass or more, or 1 part by mass or more, or 2 parts by mass or more based on 100 parts by mass of the base resin (the thermoplastic resin in one embodiment). Or 3 parts by mass or more, and the upper limit is preferably 40 parts by mass or less, or 30 parts by mass or less, or 20 parts by mass or less, or 10 parts by mass or less. From the viewpoint of the balance between the fluidity of the resin composition at the time of melting and the mechanical properties, it is desirable that the amount of fine cellulose be within the above range. In one embodiment, since the composite particles in a dry state are highly redispersed after being mixed into the base resin, sufficient mechanical properties can be realized even if the amount of fine cellulose relative to the resin is small. Specifically, the ratio of the fine cellulose can be preferably 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the base resin. In particular, since excellent mechanical properties can be realized even when the amount is 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the base resin, problems such as moisture absorption of the composition as well as coloring and odor are minimized. can do.

複合 The content of the composite particles in the resin composition may be 0.5 to 40% by mass, more preferably 10 to 20% by mass.

In one embodiment, a resin composition using the composite particles of the present disclosure is a comparative resin composition using fine cellulose alone (ie, not as composite particles) and having the same fine cellulose ratio in the resin composition. When evaluated as a ratio to the value of
The tensile breaking strength is preferably 1.03 or more, more preferably 1.05 or more, still more preferably 1.10 or more, and most preferably 1.15 or more, and / or the tensile breaking elongation is preferably 1 or more. 0.05 or more, more preferably 1.10 or more, still more preferably 1.20 or more, and most preferably 1.30 or more, and / or a flexural modulus of preferably 1.03 or more, more preferably 1.30 or more. 05 or more, more preferably 1.10 or more, most preferably 1.15 or more, and / or the coefficient of linear expansion is preferably 0.90 or less, more preferably 0.85 or less, and still more preferably 0.80 or less. Or less, most preferably 0.75 or less.

In one embodiment, the change in storage modulus of the resin composition is preferably 0.98 or less, more preferably 0.95, even more preferably 0.90 or less, and most preferably 0.85 or less.
The change in storage modulus is calculated according to the following equation.
Change in storage modulus = storage modulus at low temperature / storage modulus at high temperature For example, for polyamide 6, the low / high temperature is 0 ° C / 150 ° C, and for polypropylene is -50 ° C / 100 ° C. Generally, the storage elastic modulus decreases as the temperature increases, so that the change in the storage elastic modulus becomes 1 or more. The closer this value is to 1, the smaller the change in storage modulus at high temperature and the higher the heat resistance (the higher the rigidity at high temperature).

In the resin composition in which fine cellulose is added to the base resin in the form of composite particles, the dispersibility of the fine cellulose is improved as compared with the resin composition in which fine cellulose is directly added to the base resin. . A state in which the dispersibility of the fine cellulose is poor means that the fine cellulose exists as a coarse aggregate. Since coarse aggregates serve as fracture starting points at the time of a tensile test, the presence of coarse aggregates is not preferable in the production of a resin composition because the tensile strength at break and elongation are reduced when compared with an ideal dispersion state. Also, the presence of coarse aggregates means a decrease in the amount of fine cellulose that effectively contributes as a filler, lowers the flexural modulus when compared to the ideal dispersion state, and changes the linear expansion coefficient and the storage modulus. It is not preferable in the production of the resin composition because it deteriorates.

樹脂 Since the resin composition of the present disclosure can have improved dispersibility of fine cellulose, it can exhibit lower linear expansion than a conventional resin composition containing fine cellulose. In one embodiment, the linear expansion coefficient of the resin composition in a temperature range of 0 ° C. to 60 ° C. is preferably 80 ppm / k or less, more preferably 70 ppm / k or less, further preferably 60 ppm / k or less, and further preferably 55 ppm / k. Or less, particularly preferably 50 ppm / k or less, most preferably 45 ppm / k or less. The linear expansion coefficient is preferably as low as possible, but may be, for example, 10 ppm / k or more, or 15 ppm / k or more from the viewpoint of ease of production of the resin composition.

From the viewpoint of eliminating strength defects of a molded article obtained by using the resin composition of the present disclosure, in one embodiment, the variation coefficient CV of tensile strength at break of the resin composition is preferably 15% or less. The coefficient of variation referred to here is a value expressed as a percentage obtained by dividing the standard deviation (σ) by the arithmetic mean (μ) and multiplying by 100, and is a number without a unit representing relative variation.
CV = (σ / μ) × 100
Here, μ and σ are given by the following equations.

Here, xi is a single piece of data of the tensile breaking strength among the n pieces of data x1, x2, x3,... Xn.
The number of samples (n) for calculating the coefficient of variation CV of the tensile rupture strength is desirably at least 10 or more in order to easily find defects in the resin composition. More preferably, it is 15 or more.

より A more preferable upper limit of the coefficient of variation is 12%, or 10%, or 9%, or 8%, or 7%, or 6%, or 5%. The lower limit is preferably 0%, but is preferably 0.1% from the viewpoint of manufacturability. In one embodiment, the coefficient of variation in the above range can be realized by using a combination of fine cellulose (particularly fine cellulose fibers) and a cellulose derivative. In one embodiment, when a fine cellulose fiber and a cellulose derivative are used in combination, the fine cellulose fiber can be present in the resin composition at a higher dispersibility and a higher concentration than the fine cellulose fiber alone. This breakthrough eliminates the occurrence of partial strength defects found in resin molded products made of conventional resin compositions containing fine cellulose fibers, and significantly improves the reliability as actual products. Effects can be obtained.

The partial strength defect as described above of a conventional resin molded product is caused by the aggregation of fine cellulose (fine cellulose fibers in one embodiment) in a base resin (thermoplastic resin in one embodiment), and the vicinity of the aggregate. It is considered that the formation of voids (voids) occurs. As an index for evaluating the easiness of formation of the strength defect, there is a method in which a tensile test is performed on a plurality of test pieces and the presence / absence and the number of variations in the breaking strength are confirmed.

For example, if voids derived from aggregates of fine cellulose are present in the molded bodies of automobile bodies, structural parts such as door panels and bumpers, when a large stress is instantaneously applied to the molded bodies, or as in vibration Although the stress is small, when the stress is repeatedly applied, the stress concentrates on the above-mentioned non-uniform portions and voids. Eventually, these compacts are destroyed by the concentrated stress. This is a reduction in the reliability of the product.

Conventionally, as a method of predicting the structural defects occurring in the actual product at the test stage, for example, a method of confirming the dispersibility of fine cellulose in the product with a microscope or the like has been used. However, observation with a microscope or the like is extremely microscopic observation, cannot comprehensively evaluate the entire test piece and the entire product, and it is difficult to foresee accurately.

(4) The present inventors have found out that there is a correlation between the coefficient of variation of the tensile strength at break and the ratio of structural defects of a product during various studies.

To describe in more detail, for example, if the material has a homogeneous internal structure and does not have voids and the like, even when a tensile break test of a plurality of samples is performed, the stress at the time of breakage is between the plurality of samples. The values are almost the same, and the coefficient of variation is very small. However, in a material having a non-uniform portion or a void inside, the stress leading to fracture in one sample has a great difference from the stress of another sample. Such a degree of the number of samples exhibiting stress different from the stress of other samples can be clarified by using a scale called a coefficient of variation.

と For example, in the case of a material having no yield strength, for example, a sample having an internal defect leads to fracture at a lower strength than other samples. Also, in the case of a material having a yield strength, after the yield, it often breaks on the way to necking, and the sample having a defect inside has a higher strength than the other samples. The tendency to reach. Although there is a difference in the behavior in this way, the possibility of occurrence of a strength defect in an actual product can be expected by using a scale of a coefficient of variation of tensile strength at break.

(4) It is considered that the dispersion state of the fine cellulose in the composition greatly affects the coefficient of variation of the tensile strength at break. There are various techniques for improving the dispersion state. For example, a method for optimizing the ratio of fine cellulose to a cellulose derivative, a method for optimizing the diameter and / or L / D of fine cellulose, optimizing screw arrangement during melt kneading in an extruder, Method of giving sufficient shearing to fine cellulose by optimizing resin viscosity by control, method of strengthening interface between resin and fine cellulose by adding an optimal organic component (for example, surfactant) additionally, There are various approaches such as a method for forming some kind of chemical bond with cellulose, a method for chemically modifying the surface of fine cellulose, and a method for optimizing a method for preparing a composite of fine cellulose and a cellulose derivative. Either of these approaches may be employed to improve the dispersion of the fine cellulose. Setting the coefficient of variation CV of the tensile strength at break to 10% or less can contribute to the elimination of the strength defect of the obtained molded article, and has the effect of greatly improving the strength of the molded article.

In one embodiment, the tensile yield strength tends to be dramatically improved as compared to the thermoplastic resin alone in the resin composition. The ratio of the tensile yield strength of the resin composition when the tensile yield strength of the composition containing no fine cellulose or the thermoplastic resin alone is set to 1.0 is preferably 1.05 times or more, more preferably It is at least 1.10 times, still more preferably at least 1.15 times, particularly preferably at least 1.20 times, and most preferably at least 1.3 times. The upper limit of the ratio is not particularly limited, but is preferably, for example, 5.0 times, and more preferably 4.0 times, from the viewpoint of ease of production.

In one embodiment, the resin composition has excellent dispersion uniformity in the composition of fine cellulose, and thus also has a feature that the variation in linear expansion coefficient in a large molded product is small. Specifically, the characteristic is that the variation of the coefficient of linear expansion measured using the test pieces collected from different portions of the large molded body is extremely low.

場合 When the dispersion of the fine cellulose in the composition is not uniform and the difference in linear expansion coefficient is large depending on the site, a problem such as distortion or warpage of the molded body is likely to occur due to temperature change. In addition, this failure is a failure mode that occurs due to a difference in thermal expansion and reversibly occurs when the temperature rises and falls. Therefore, the failure mode may have a potential danger that it cannot be recognized by checking at room temperature.

大 The magnitude of the variation of the linear expansion coefficient can be expressed by using the variation coefficient of the linear expansion coefficient of the measurement sample obtained from a different portion of the site. The coefficient of variation here is the same as that described in the section on the coefficient of variation of tensile strength at break.

In one embodiment, the coefficient of variation of the linear expansion coefficient obtained from the resin composition is preferably 15% or less. A more preferred upper limit of the variation coefficient is 13%, further preferably 11%, more preferably 10%, still more preferably 9%, and most preferably 8%. The lower limit is preferably 0%, but is preferably 0.1% from the viewpoint of ease of production.
The number of samples (n) for calculating the coefficient of variation of the linear expansion coefficient is desirably at least 10 or more in order to reduce the influence of data errors and the like.

製造 Method for producing resin composition≫
In one embodiment, the resin composition can be produced by mixing the composite particles and the base resin, and performing hot-melt kneading, thermosetting, light curing, vulcanization, and the like. Further, a molded article can be produced by molding the resin composition. The form in which the composite particles are added in the production of the resin composition is not particularly limited, and may be a slurry containing water as well as the dry powder. The slurry containing water can be prepared by a method of stopping the drying in the course of the drying process of the above-described method for producing composite particles, a method of once drying, and a method of adding water.

In one embodiment, the method for producing a resin composition comprises melt-kneading the composite particles in the form of a dry powder or an aqueous dispersion with a thermoplastic resin (in one embodiment, a thermoplastic resin different from the thermoplastic resin in the composite particles). Kneading inside a molding machine and then molding.
In another aspect, a method for producing a resin composition comprises mixing the composite particles with a thermosetting resin, then molding and then performing a thermosetting treatment, or mixing the composite particles with a photocurable resin, Molding and then photo-curing.
In another aspect, a method for producing a resin composition includes the steps of mixing the composite particles with a rubber, molding, and then vulcanizing.

The method for producing the resin composition when the base resin is a thermoplastic resin is not particularly limited, for example,
1. Using a single-screw or twin-screw extruder, after melt-kneading a mixture of composite particles (dry powder or aqueous dispersion) and a thermoplastic resin,
(1) a method of extruding into a strand, cooling and solidifying in a water bath to obtain a pellet-shaped molded product of the resin composition,
(2) a method of obtaining an extruded product of the resin composition by extruding and cooling into a rod or a tube, or (3) a method of extruding from a T-die to obtain a sheet or film of the resin composition, or 2 . The composite particles (dry powder or aqueous dispersion) and a thermoplastic resin monomer are mixed, and a polymerization reaction (specifically, solid-phase polymerization, emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or the like) is performed, and the obtained mixture is obtained. Extruding the resulting product by any of the above methods (1) to (3) to obtain a molded article of the resin composition;
3. An aqueous dispersion of a base resin monomer, fine cellulose, and a cellulose derivative is mixed, a polymerization reaction is performed, and the obtained product is extruded by any one of the above (1) to (3) to obtain a resin composition. A method of obtaining a molded body,
And the like.

In another aspect, a more specific method for producing a resin composition can include the following.
1. After mixing the base resin, the dried fine cellulose, the cellulose derivative powder, and the dispersant in a desired ratio as needed, a method of collective melt kneading,
2. After mixing the base resin, the fine cellulose water slurry, the cellulose derivative powder, and the dispersant in a desired ratio as needed, a method of melt-kneading all at once,
3. After preparing a composite of fine cellulose and a cellulose derivative in advance, after mixing the base resin and the dispersant as required in a desired ratio, a method of melt-kneading all at once,
4. After melt-kneading the base resin and, if necessary, the dispersant, adding a dried fine cellulose and cellulose derivative powder mixed in a desired ratio, and further melt-kneading,
5. After melt-kneading the base resin and the dispersant as necessary, adding a fine cellulose water slurry and cellulose derivative powder mixed in a desired ratio, and further melt-kneading,
6. After melt-kneading the base resin and the dispersant if necessary, adding a composite of fine cellulose and a cellulose derivative prepared in advance at a desired ratio, and further melt-kneading,
And the like.

(4) When the base resin is a thermoplastic resin, the heating temperature when melt-kneading the mixture of the composite particles and the base resin can be adjusted according to the resin used. The minimum processing temperature recommended by the thermoplastic resin supplier is 255 to 270 ° C for nylon 66, 225 to 240 ° C for nylon 6, 170 to 190 ° C for polyacetal resin, and 160 to 180 ° C for polypropylene. The heating set temperature is preferably in the range of 20 ° C. higher than these recommended minimum processing temperatures. By setting the mixing temperature within this temperature range, the mixed components can be uniformly mixed.

The moisture content of the resin composition is not particularly limited. For example, in the case of polyamide, it is preferably 10 ppm or more in order to suppress an increase in the molecular weight of the polyamide during melting, and 1200 ppm in order to suppress hydrolysis of the polyamide during melting. It is preferably at most 900 ppm, more preferably at most 900 ppm, most preferably at most 700 ppm. The moisture content is a value measured using a Karl Fischer moisture meter by a method based on ISO # 15512.

樹脂 The resin composition of the present embodiment can be provided in various shapes. Specific examples include resin pellets, sheets, fibers, plates, and rods. Among them, the resin pellet shape is more preferable from the viewpoint of easiness of post-processing and transportation. Preferable pellet shapes at this time include a round shape, an elliptical shape, a cylindrical shape, and the like, and these differ depending on a cutting method at the time of extrusion. Pellets cut by a cutting method called underwater cut are often round, and pellets cut by a cutting method called hot cut are often round or oval, and cuts called strand cuts The pellets cut by the method often have a columnar shape. In the case of a round pellet, the preferred size is 1 mm or more and 3 mm or less as a pellet diameter. Further, in the case of a cylindrical pellet, a preferred diameter is 1 mm or more and 3 mm or less, and a preferred length is 2 mm or more and 10 mm or less. The above-mentioned diameter and length are desirably not less than the lower limit from the viewpoint of operation stability during extrusion, and desirably not more than the upper limit from the viewpoint of biting into a molding machine in post-processing.

In one embodiment, the resin composition may be a composite of a nonwoven fabric (which is also simply referred to as a nonwoven fabric) made of fine cellulose fibers to which a cellulose derivative is attached, and a thermoplastic resin. Although not particularly limited, such a resin composition can be produced by, for example, the following operation.
(A) A method of impregnating a non-woven fabric with a thermoplastic resin precursor and polymerizing the precursor.
(B) A nonwoven fabric is impregnated or coated with a solution containing a thermoplastic resin or a thermoplastic resin precursor, dried, adhered by a hot press or the like, and polymerized and cured as necessary. How to let.
(C) A method in which a non-woven fabric is impregnated with a melt of a thermoplastic resin and adhered by a hot press or the like.
(D) A method in which a thermoplastic resin sheet and a non-woven fabric are alternately arranged and closely adhered by a hot press or the like.

The method for obtaining the nonwoven fabric composed of the fine cellulose fibers to which the cellulose derivative is attached is not particularly limited. For example, as described above, the fine cellulose fiber water slurry to which the cellulose derivative is attached is dried after papermaking or coating. And a method in which a nonwoven fabric is first obtained by using fine cellulose fibers alone, an organic solvent in which a cellulose derivative is dissolved is applied to the nonwoven fabric, and then dried.

樹脂 The resin composition using a thermoplastic resin as a base resin can be molded into a resin molded article having various shapes (for example, a film shape, a sheet shape, a fiber shape, a plate shape, a pellet shape, a powder shape, and a three-dimensional structure). Although there is no particular limitation on the method for producing the resin molded body, injection molding (for example, injection compression molding, injection press molding, gas assist injection molding, and ultra high speed injection molding), various extrusion molding (cold runner method or hot runner method), Examples include foam molding (including by injection of supercritical fluid), insert molding, in-mold coating molding, heat-insulating mold molding, rapid heating / cooling mold molding, and various shape extrusion molding (eg, two-color molding and sandwich molding). it can. For example, various extrusion moldings are suitable for molding sheets, films, fibers and the like. For forming a sheet or film, an inflation method, a calendar method, a casting method, or the like can be used. Furthermore, it is also possible to form a heat-shrinkable tube by performing a specific stretching operation. It is also possible to form a hollow molded product by rotational molding or blow molding. Among these, the injection molding method is particularly preferable from the viewpoint of design and cost.

The method for producing the resin composition in which the base resin is a thermosetting resin or a photocurable resin is not particularly limited. For example, the composite particles are sufficiently dispersed in a base resin solution or a base resin powder dispersion and dried. A method in which the composite particles are sufficiently dispersed in a base resin monomer liquid and polymerized by heat, UV irradiation, a polymerization initiator, etc., and a base formed of the composite particles (eg, a sheet, a powder particle formed body, etc.) A method of sufficiently impregnating and drying a resin solution or a base resin powder dispersion, a method of sufficiently impregnating a molded body composed of composite particles with a base resin monomer liquid, and polymerizing with heat, UV irradiation, a polymerization initiator, and the like. No. Upon curing, various polymerization initiators, curing agents, curing accelerators, polymerization inhibitors and the like can be blended.

樹脂 A resin composition containing a thermosetting resin or a photocurable resin as a base resin can be used as various resin molded articles. There is no particular limitation on the method for producing the resin molded body.

In the case of a thermosetting resin, if a plate-like product is to be manufactured, an extrusion molding method is generally used, but a flat press can also be used. In addition, a profile extrusion method, a blow molding method, a compression molding method, a vacuum molding method, an injection molding method, or the like can be used. In addition, if a film-shaped product is to be produced, a solution casting method can be used in addition to a melt extrusion method. When a melt molding method is used, blown film molding, cast molding, extrusion lamination molding, calender molding, sheet molding. , Fiber molding, blow molding, injection molding, rotational molding, coating molding and the like.

Alternatively, a method may be used in which after a sheet called an uncured or semi-cured prepreg is produced, the prepreg is formed into a single layer or a laminate, and the resin is cured and molded by applying pressure and heat. The method of applying heat and pressure includes a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, and the like, but is not limited to these molding methods.

Further, a method of impregnating a filament or preform of a reinforcing fiber such as a carbon fiber with a resin composition before the base resin is cured, and then curing the base resin to obtain a molded product (for example, RTM, VaRTM, filament winding, RFI etc.), but are not limited to these molding methods.

場合 When the base resin is a photocurable resin, a molded article can be manufactured by various curing methods using active energy rays.

The method for producing the resin composition when the base resin is rubber is not particularly limited.For example, a method of kneading the composite particles and the rubber in a dry manner, dispersing or dissolving the composite particles and the rubber in a dispersion medium. And then kneading by drying. As a mixing method, a high shearing force and pressure are applied, and a mixing method using a homogenizer is preferable in that the dispersion can be promoted.In addition, a propeller-type stirring device, a rotary stirring device, an electromagnetic stirring device, manual stirring, etc. A method can also be used. The obtained resin composition is molded into a desired shape and can be used as a molding material. Examples of the shape of the molding material include a sheet, a pellet, and a powder.

樹脂 Resin compositions using rubber as a base resin can be used as various resin molded articles. There is no particular limitation on the method for producing the resin molded body, and the molding material is molded using a desired molding method such as, for example, mold molding, injection molding, extrusion molding, hollow molding, foam molding, or the like. A molded product of sulfur can be obtained. The unvulcanized molded body can be vulcanized by heat treatment or the like as necessary.

One aspect of the present disclosure is:
A thermoplastic resin as a base resin, and composite particles of the present disclosure (for example, composite particles composed of fine cellulose and a cellulose derivative),
A method for producing a resin composition comprising:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
A method comprising: In the present disclosure, the phrase “the composite particle is composed of fine cellulose and a cellulose derivative” means that the composite particle is composed mainly of the fine cellulose and the cellulose derivative (that is, the total amount of the fine cellulose and the cellulose derivative is the composite particle 100). (To be more than 50% by mass with respect to% by mass), and does not exclude inclusion of a third component such as an additive.

パル Pulp, which is an aggregate of fine cellulose having a high elastic modulus, is defibrated at a beating level and used as a resin filler. Since pulp with a low degree of defibration has a relatively good dispersion in the resin, kneading is possible even if the dried pulp is added to the thermoplastic resin, and a constant quality level is maintained in the subsequent extruded product. be able to. However, in such a composite material of pulp and thermoplastic resin, pulp fibers of a few millimeters to hundreds of micrometer level are only dispersed in the thermoplastic resin as a filler due to weak interaction, and the In order to improve the physical properties, a large amount of pulp fibers must be put into the thermoplastic resin as in other fillers such as talc (at least 20% by mass or more of the total mass of the composite material). On the other hand, when fine cellulose having a nanometer size (ie, less than 1 μm) is used as a filler component, by appropriately controlling the interaction between the fine celluloses, 10% by mass or less, preferably 5% by mass of the total mass of the resin composition. With the following amount of fine cellulose, it is possible to form a highly extended network structure in the thermoplastic resin. This network structure significantly improves the mechanical properties of the composite of fine cellulose and thermoplastic resin. In a typical embodiment, the fine cellulose capable of forming the above network structure can form a highly elastic gel state in, for example, an aqueous dispersion medium before kneading with a thermoplastic resin. The cellulose derivative controls the interaction between the fine celluloses, and thus contributes to controlling the state of dispersion between the fine celluloses in the base resin.

(4) It is preferable that the diameter of fine cellulose (particularly cellulose whiskers and / or cellulose fibers) alone be nanometer-sized (that is, less than 1 μm) from the viewpoint of effectively forming a cellulose aggregate in the second step.

において In the second step, a single-screw extruder, a twin-screw extruder, or the like can be used as an extruder, but a twin-screw extruder is preferable in controlling the dispersibility of cellulose. L / D obtained by dividing the cylinder length (L) of the extruder by the screw diameter (D) is preferably 40 or more, and particularly preferably 50 or more. The screw rotation speed during kneading is preferably in the range of 100 to 800 rpm, more preferably in the range of 150 to 600 rpm. These vary depending on the screw design.

各 Each screw in the cylinder of the extruder is optimized by combining an elliptical two-wing screw-shaped full flight screw, a kneading element called a kneading disk, and the like.

In one embodiment, an addition port is provided in the middle of the cylinder of the extruder, and the raw material charged into the addition port is guided to a screw in the cylinder. In one aspect, the position of the addition port is located downstream of the melt-kneading zone where the first step is performed. In normal kneading using an extruder, the first resin melting zone is the region where the shearing is most intense. The filler is finely dispersed by the shearing force below. However, when cellulose is finely dispersed in a resin as a reinforcing filler, if cellulose is added before the resin melting zone, the cellulose may deteriorate due to strong shearing force in the resin melting zone. In particular, in the case of using fine cellulose having a diameter of nanometer (i.e., less than 1 μm) in a simple substance of cellulose, since the surface area is extremely large, the addition ratio of the usual filler component to the resin (specifically, the filler component When a reinforced resin composition is designed with a filler component of 20% by mass or more with respect to a total of 100% by mass of the resin and the resin, the degradation of the fine cellulose due to the above-mentioned shearing force increases, and the original strong crystal of the fine cellulose is Problems such as loss of structure, deterioration of mechanical properties as a reinforced resin, coloring and odor may occur.

複合 Since the composite particles of the present disclosure can have excellent redispersibility even in a dry state, they can be finely dispersed without exposing the composite particles under the above-mentioned shearing. That is, the composite particles can be added in the second step to the thermoplastic resin melted in the first step. The composite particles composed of fine cellulose and a cellulose derivative are rapidly and finely dispersed in a resin already in a molten state, and the amount thereof is extremely small, for example, 10 parts by mass with respect to 100 parts by mass of a thermoplastic resin as a base resin. Parts or less, it can exhibit a good function as a reinforcing filler, can reliably improve the mechanical properties of the finally obtained resin composition, and can also satisfactorily suppress problems such as coloring and odor.

添加 The addition port is preferably designed downstream of the melt-kneading zone of the extruder for the purpose of reducing the heat history received when passing through the inside of the cylinder. Specifically, the length (L2) from the outlet of the cylinder to the addition port is preferably designed to be １／ or less of the total length (L1) of the cylinder. Note that the entire length of the cylinder includes a portion not involved in kneading (for example, a transport zone).

複合 Composite particles composed of fine cellulose and a cellulose derivative are introduced from the addition port and mixed into the thermoplastic resin melt-kneaded in the extruder. Since the composite particles of this embodiment are excellent in redispersibility, they can be highly dispersed in the resin even when introduced in a subsequent step in an extruder.

場合 If the thermoplastic resin is an engineered plastic having excellent heat resistance, its melting temperature is extremely high, so that during processing, a strong heat history is applied to the fine cellulose, and coloring and odor problems due to burning are likely to occur. In addition, since this strong thermal history partially loses the excellent mechanical properties of cellulose (particularly natural cellulose), the mechanical properties of the resin composition are improved when cellulose is added as a filler to the thermoplastic resin. Decrease the effect.

In the present embodiment, since the fine cellulose is modified into a composite particle having excellent redispersibility even in a dry state using a cellulose derivative in advance, the resin melted in the first step (Preferably downstream of the melt kneading zone of the extruder, more preferably L2 / L1 is １／ or less, further preferably L2 / L1 is １／ or less, most preferably L2 / L1 is １／ or less. Even if the composite particles are added to the cylinder (from the addition port located), a resin composition in which fine cellulose is highly dispersed can be produced. In the fine cellulose charged in the above-described mode, the heat history is reduced, so that the generation of coloring and odor due to burning is suppressed. In addition, according to the method of the present embodiment, a high degree of dispersion of the fine cellulose can be realized together with the relaxation of the heat history, so that a high mechanical property of the resin composition can be realized.

Downstream of the extruder including the addition port (side feeder), a degas cylinder, a vacuum vent, etc. are provided as appropriate to degas air and a small amount of water (water vapor) mixed when the composite particles are charged. it can.

二 In the twin-screw extruder, high pressure is applied to the resin at the tip discharge section, and the resin temperature tends to rise. A gear pump can be installed downstream for the purpose of controlling the resin pressure and reducing the rise in resin temperature.

In the present embodiment, the distance in which the composite particles composed of the fine cellulose and the cellulose derivative are conveyed in the extruder can be shortened as compared with the thermoplastic resin, so that the configuration of the screw in the cylinder after mixing the composite particles is reduced. By devising it, it is possible to realize reliable homogeneous dispersion. Specifically, the present invention is not limited to this. By providing at least one counterclockwise screw that creates a feed in the direction opposite to the traveling direction in the cylinder downstream of the addition port, the fine cellulose is removed. Advanced dispersion can be realized more reliably.

≪Molded body≫
The molded article obtained from the resin composition of the present embodiment may have any shape depending on the application, and may have a three-dimensional three-dimensional shape, a sheet shape, a film shape, or a fibrous shape. For example, a part (for example, several places) of the molded body may be melted by heat treatment, and may be used by being adhered to a resin or metal substrate, for example. The molded body may be a coating film applied to a resin or metal substrate, or may form a laminate with the substrate. The sheet, film, or fibrous formed body may be subjected to secondary processing such as annealing, etching, corona processing, plasma processing, grain transfer, cutting, and surface polishing.

Since the resin composition of the present embodiment has high heat resistance and light weight, it can be substituted for a steel plate, or a fiber reinforced plastic such as a carbon fiber reinforced plastic or a glass fiber reinforced plastic, or a resin composite containing an inorganic filler. For example, industrial machine parts (for example, electromagnetic equipment housing, roll material, transfer arm, medical equipment members, etc.), general machine parts, automobile / railway / vehicle parts (for example, outer plates, chassis, aerodynamic members, seats, Frictional material inside the transmission, etc.), marine components (for example, hull, seat, etc.), aviation-related parts (for example, fuselage, main wing, tail wing, rotor blade, fairing, cowl, door, seat, interior materials, etc.), spacecraft, Satellite members (motor case, main wing, structure, antenna, etc.), electronic and electric parts (for example, personal computer housing, mobile phone housing, OA equipment, AV equipment, telephone, facsimile, home appliances, toy supplies, etc.), architecture・ Civil engineering materials (for example, reinforcing steel substitute materials, truss structures, suspension bridge cables, etc.), daily necessities, sports and leisure goods (for example, golf club shafts, fishing rods, Varnish or badminton rackets or the like), a wind power generation housing member or the like, also containers and packaging member, for example, can be a material for the high pressure container to be filled with hydrogen gas or the like, such as those used in fuel cells.
Among these, automotive members that require resin molding can exhibit advantages due to higher heat resistance and lighter weight than existing resin compositions. In particular, it is useful for gears, engine covers, radiator tanks, intake manifolds and the like, which are members around the engine used in a high temperature environment. When rigidity in a high temperature environment is low, misalignment or loss of teeth occurs in complicated structures such as gears, and damage to joints with other members in containers such as engine covers, radiator tanks, intake manifolds, etc. And deformation. Therefore, the resin composition of the present embodiment having excellent high-temperature stiffness is most suitable for a member used in a high-temperature environment. In addition, the resin composition of the present embodiment has high heat resistance, light weight and high strength, as well as low linear expansion, because the fine cellulose is satisfactorily dispersed, and also has excellent surface properties and sliding properties. Cooling fan, canister, rocker cover, ornament cover, radiator drain cap, radiator fan, cylinder head cover, oil pan, oil reservoir tank, gasoline tank, cable liner, fastener clip, engine mount, engine fan, spark Suitable for plug cover, spark plug cap, junction block, relay block, connector, brake pipe, fuel pipe tube, waste gas system parts intake system parts, exhaust system parts, etc.

The resin composition according to one aspect of the present disclosure can have high mechanical properties and low linear expansion, and / or can have high fluidity that can accommodate large parts, and / or have a partial fluidity. Since it is possible to provide a molded article substantially free of high strength defects, the molded article may be various large parts.

The present disclosure includes the following aspects.
<Aspect A>
[1] A composite particle containing fine cellulose and a thermoplastic resin,
The ratio of fine cellulose in the composite particles is 10% by mass or more and 95% by mass or less,
The dispersion η10 at a liquid temperature of 25 ° C. and a shear rate of 10 s ⁻¹ has a viscosity η ₁₀ of 10 mPa · s, obtained by dispersing the composite particles in DMSO such that the concentration of fine cellulose in the dispersion becomes 1% by mass. That is the composite particle.
[2] The thixotropic index (TI), which is the ratio of the viscosity η ₁₀ at a shear rate of 10 s ⁻¹ to the viscosity η _{100 at} a shear rate of _{100 s} ⁻¹ at a liquid temperature of 25 ° C., η ₁₀ / η ₁₀₀ , is obtained. 2. The composite particle according to the above aspect 1, which is 2 or more.
[3] The composite particles according to the

above aspect

1 or 2, wherein the median particle diameter is 1 μm or more and 5000 μm or less.
[4] The composite particles according to any one of the above-described embodiments 1 to 3, wherein the thermoplastic resin is soluble in DMSO.
[5] The composite particles according to the above aspect 4, wherein the thermoplastic resin is a cellulose derivative.
[6] The composite particle according to any of the above aspects 1 to 5, wherein the fine cellulose has a specific surface area equivalent diameter of 2 nm or more and less than 1000 nm.
[7] The composite particle according to any one of Aspects 1 to 6, wherein a part of the fine cellulose is chemically modified, and the fine cellulose has an I-type crystal structure.
[8] The composite particle according to the above aspect 7, wherein the chemical modification is acetylation.
[9] The method for producing a composite particle according to any one of the above aspects 1 to 8,
A method comprising a powdering step of mixing an aqueous dispersion of fine cellulose and particles of a thermoplastic resin and then drying to collect the composite particles.
[10] The aqueous dispersion of the fine cellulose is
Fibrillation step of performing a fibrillation treatment of cellulose in an organic solvent to obtain a fine cellulose dispersion, and a purification step of substituting water for the organic solvent in the fine cellulose dispersion,
The production method according to the above aspect 9, which is prepared by the following method.
[11] The method according to the above aspect 10, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with the defibration step or after the defibration step and before the purification step.
[12] The method for producing a composite particle according to any one of the above aspects 1 to 8,
Preparation of fine cellulose / resin dispersion by adding thermoplastic resin to organic solvent dispersion of fine cellulose to obtain fine cellulose / resin dispersion in which fine cellulose is dispersed in organic solvent and thermoplastic resin is dissolved Process,
A precipitation step of obtaining a composite particle dispersion by mixing the fine cellulose / resin dispersion with a poor solvent for the thermoplastic resin and precipitating composite particles containing the fine cellulose and the thermoplastic resin;
A purification step of replacing the organic solvent in the composite particle dispersion with water to obtain an aqueous dispersion, and a powdering step of drying the aqueous dispersion to collect composite particles,
Including, methods.
[13] The method for producing composite particles according to the above aspect 12, wherein the organic solvent dispersion of fine cellulose is prepared by a defibration step of defibrating cellulose in an organic solvent.
[14] The method according to the above aspect 13, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with or after the defibration step.
[15] A resin composition comprising the composite particle according to any one of the above aspects 1 to 8 and a base resin.
[16] The resin composition according to the above aspect 15, wherein the base resin is a thermoplastic resin.
[17] The resin composition according to the above aspect 15, wherein the base resin is a thermosetting resin or a photocurable resin.
[18] The resin composition according to the above aspect 15, wherein the base resin is a rubber.
[19] The method for producing a resin composition according to the above aspect 16, wherein
A method comprising kneading the composite particles in the form of a dry powder or an aqueous dispersion with a thermoplastic resin inside a melt-kneading molding machine, and then molding.
[20] The method for producing a resin composition according to the above aspect 17, wherein
Mixing the composite particles with a thermosetting resin and then molding and then performing a thermosetting process; or mixing the composite particles with a photocurable resin and then molding and then performing a photocuring process,
Including, methods.
[21] The method for producing a resin composition according to the above aspect 18, wherein
Mixing the composite particles with rubber, then molding and then vulcanizing.

<Aspect B>
[1] thermoplastic resin,
0.1 to 40 parts by mass based on 100 parts by mass of the thermoplastic resin, fine cellulose fibers having a fiber diameter of 2 nm or more and less than 1 μm, and 1 part by mass to 500 parts by mass based on 100 parts by mass of the fine cellulose fibers Of a cellulose derivative,
A resin composition comprising:
[2] The thermoplastic resin is selected from the group consisting of polyolefin resins, polyamide resins, polyester resins, polyacetal resins, polyphenylene ether resins, polyphenylene sulfide resins, and mixtures of any two or more of these. The resin composition according to the above aspect 1.
[3] The above aspect, wherein the thermoplastic resin is polypropylene, and the melt mass flow rate (MFR) of the polypropylene measured at 230 ° C. based on ISO1133 is 3 g / 10 min or more and 30 g / 10 min or less. 2. The resin composition according to 1.
[4] The thermoplastic resin is a polyamide resin, and a ratio of a carboxyl terminal group to all terminal groups ([COOH] / [all terminal groups]) of the polyamide resin is 0.30 to 0.95. The resin composition according to the above aspect 1.
[5] The thermoplastic resin is a polyester resin, and the ratio of carboxyl terminal groups to all terminal groups ([COOH] / [all terminal groups]) of the polyester resin is 0.30 to 0.95. The resin composition according to the above aspect 1.
[6] The resin composition according to the above aspect 1, wherein the thermoplastic resin is a polyacetal resin, and the polyacetal resin is a copolyacetal containing 0.01 to 4 mol% of a comonomer-derived structure.
[7] The resin composition according to any one of Aspects 1 to 6, wherein the cellulose derivative is at least one selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate.
[8] The resin composition according to any one of Aspects 1 to 7, wherein the fine cellulose fiber has a fiber diameter of 500 nm or less.
[9] The resin composition according to any one of Embodiments 1 to 8, wherein the crystallinity of the fine cellulose fibers is 50% or more.
[10] The resin composition according to any of aspects 1 to 9, wherein the fine cellulose fibers are chemically modified fine cellulose fibers.
[11] The resin composition according to the above aspect 10, wherein the chemically modified fine cellulose fiber is an esterified fine cellulose fiber.
[12] The resin composition according to any of the above aspects 1 to 11, further comprising cellulose whiskers in an amount of 10 to 500 parts by mass based on 100 parts by mass of the fine cellulose fibers.
[13] The resin composition according to any one of Embodiments 1 to 12, wherein the coefficient of variation (standard deviation / arithmetic mean) of the tensile rupture strength of the resin composition is 15% or less.
[14] The resin composition according to any of aspects 1 to 13, wherein the tensile yield strength of the resin composition is at least 1.05 times the tensile yield strength of the thermoplastic resin.
[15] The resin composition according to any of aspects 1 to 14, wherein the resin composition has a coefficient of linear expansion in the range of 0 ° C to 60 ° C of 80 ppm / k or less.
[16] A resin pellet formed from the resin composition according to any one of the above aspects 1 to 15.
[17] A resin molded article formed from the resin composition according to any one of the above aspects 1 to 15.

<Aspect C>
[1] a thermoplastic resin,
Composite particles composed of fine cellulose and a cellulose derivative,
A method for producing a resin composition comprising:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
And a manufacturing method.
[2] The first step is performed in a melt-kneading zone in a cylinder provided in the extruder,
The manufacturing method according to the above aspect 1, wherein the second step is performed by supplying the composite particles from an addition port provided in the cylinder.
[3] The production method according to the above aspect 2, wherein the addition port is disposed downstream of the melt-kneading zone.
[4] The production method according to the

above aspect

2 or 3, wherein the length (L2) from the outlet of the cylinder to the addition port is 1/2 or less of the total length (L1) of the cylinder.
[5] Any of the above-described embodiments 2 to 4, wherein one or more counterclockwise screws for kneading and dispersing the composite particles in the thermoplastic resin are provided in a cylinder downstream of the addition port. The production method described in Crab.
[6] The production method according to any one of the first to fifth embodiments, wherein the fine cellulose constituting the composite particles is chemically modified.
[7] The production method according to the above aspect 6, wherein the chemical modification of the fine cellulose is acetylation.
[8] The method according to any one of Aspects 1 to 7, wherein the resin composition contains the fine cellulose in an amount of 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the thermoplastic resin.
[9] The microscopic cellulose according to any of the above aspects 1 to 8, wherein the fine cellulose comprises a cellulose whisker having a length / diameter ratio (L / D ratio) of less than 15 and a cellulose fiber having an L / D ratio of 150 or more. The manufacturing method as described.
[10] The production method according to any of the above aspects 1 to 9, wherein the melting point of the thermoplastic resin is 220 ° C. or higher.

本 Hereinafter, the present invention will be further described based on examples, but the present invention is not limited to these examples.

1. Raw Materials The raw materials used are described below.

≪Base resin≫
Polyamide Polyamide 6 (hereinafter simply referred to as PA6)
"UBE Nylon 1013B" available from Ube Industries, Ltd.
Carboxyl end group ratio is ([COOH] / [all end groups]) = 0.6
Polypropylene homopolypropylene (hereinafter simply referred to as PP)
"Prime Polypro J105B" available from Prime Polymer
MFR = 9.0 g / 10 min. Measured at 230 ° C. according to ISO 1133 Maleic acid-modified polypropylene (hereinafter simply referred to as MPP)
"UMEX 1001" available from Sanyo Chemical Industries, Ltd.
MFR measured at 230 ° C. according to ISO 1133 = 230 g / 10 min

熱 Composite particle (composite) thermoplastic resin≫
[Cellulose derivative]
Cellulose acetate butyrate CAB0.1 (manufactured by Eastman Chemical Company, product name CAB381-0.1, molecular weight 20,000, degree of esterification: butyl group 37 wt%, acetyl group 13 wt%, hydroxy group 1.5 wt%)
Cellulose acetate butyrate CAB20 (manufactured by Eastman Chemical Co., product name CAB381-20, molecular weight 70000, degree of esterification: butyl group 37 wt%, acetyl group 13.5 wt%, hydroxy group 1.5 wt%)
Cellulose acetate propionate CAP20 (product name: CAP482-20, manufactured by Eastman Chemical Company, esterification degree: propionyl group 48 wt%, acetyl group 1.3 wt%, hydroxy group 1.7 wt%)
[polyamide]
Polyamide 6 powder PA6 (manufactured by Metal Color Co., product name SNP-613NS)

<< Example A >>
<Production of fine cellulose>
Fine cellulose slurries used in the production of the composite particles and the single particles of the fine cellulose alone were produced according to the compositions shown in Table 1 by the following Production Examples A to E2.

[Cellulose whisker (hereinafter also referred to as CNC)]
Commercial DP pulp (average degree of polymerization: 1600) was cut and hydrolyzed in a 10% by mass aqueous hydrochloric acid solution at 105 ° C. for 30 minutes. The obtained acid-insoluble residue was filtered, washed and pH-adjusted to prepare a crystalline cellulose dispersion having a solid content of 14% by mass and a pH of 6.5. The crystalline cellulose dispersion was spray-dried to obtain a dried crystalline cellulose. Next, the dried product obtained above was supplied to an air-flow type pulverizer (STJ-400, manufactured by Seishin Enterprise Co., Ltd.) at a supply rate of 10 kg / hr and pulverized to obtain cellulose whiskers as crystalline cellulose fine powder. . The properties of the obtained cellulose whiskers were evaluated by the methods described below. The results are shown below.
L / D = 1.6
Average diameter = 200 nm
Crystallinity = 78%
Degree of polymerization = 200

[Production Example A] (fibrillation in water)
3 parts by mass of cotton linter pulp were immersed in 27 parts by mass of water and heat-treated at 130 ° C. for 4 hours in an autoclave. The obtained swollen pulp was washed with water to obtain a purified pulp containing water (30 parts by mass). Subsequently, 170 parts by mass of water was added to 30 parts by mass of purified pulp containing water and dispersed in water (solid content ratio: 1.5% by mass), and SDR14 type laboratory refiner (manufactured by Aikawa Tekko Co., Ltd.) as a disc refiner ( The aqueous dispersion was beaten for 20 minutes with a clearance between disks of 1 mm using a pressurized DISK method. Subsequently, thorough beating was performed under the condition that the clearance was reduced to a level close to almost zero to obtain a beaten water dispersion (solid content concentration: 1.5% by mass). The obtained beaten water dispersion was directly subjected to micronization treatment at an operating pressure of 100 MPa for 15 times using a high-pressure homogenizer (NSO15H manufactured by Niro Soavi Co., Ltd. (Italy)) to obtain a fine cellulose slurry (solid content: 1.5%). % By mass). Then, the mixture was concentrated to a solid content of 10% by mass with a dehydrator to obtain 30 parts by mass of slurry A (aqueous solvent).

[Production Example B1] (fibrillation in DMSO)
One part by mass of the cotton linter pulp was stirred at 500 rpm for 1 hour at room temperature in 30 parts by mass of dimethyl sulfoxide (DMSO) using a uniaxial stirrer (DKV-1 φ125 mm dissolver manufactured by Imex). Subsequently, the mixture was fed to a bead mill (NVM-1.5, manufactured by IMEX Co., Ltd.) using a hose pump, and circulated for 180 minutes using only DMSO to obtain 31 parts by mass of a slurry B1 (DMSO solvent) having a solid content of 3.2% by mass. Was.
At the time of circulation operation, the rotation speed of the bead mill was 2500 rpm, the peripheral speed was 12 m / s, the beads used were made of zirconia, φ2.0 mm, and the filling rate was 70% (the slit gap of the bead mill was 0.6 mm). During the circulation operation, the slurry temperature was controlled at 40 ° C. by a chiller in order to absorb heat generated by friction.

[Production Example B2] (fibrillation in DMSO, followed by solvent replacement with water)
After adding 30 parts by mass of pure water to the slurry B1 and sufficiently stirring, the mixture was put into a dehydrator and concentrated. A washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water is repeated a total of 5 times to remove the unreacted reagent solvent and the like, thereby obtaining a slurry B2 (water) having a solid content of 10% by mass. Solvent) was obtained in an amount of 10 parts by mass.

[Production Example C1] (fibrillation in DMSO followed by chemical modification)
After putting the slurry B1 into an explosion-proof disperser tank, 3.2 parts by mass of vinyl acetate and 0.49 parts by mass of sodium hydrogen carbonate were added, the temperature in the tank was adjusted to 70 ° C., and the mixture was stirred for 120 minutes to obtain a solid content of 2 parts. 35 parts by mass of a slurry C1 (DMSO solvent) of 9.9% by mass was obtained.

[Production Example C2] (fibrillation in DMSO, then chemical modification, then solvent replacement with water)
After 30 parts by mass of pure water was added to the slurry C1 and sufficiently stirred, the mixture was put into a dehydrator and concentrated. The washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water is repeated a total of 5 times to remove the unreacted reagent solvent and the like, thereby obtaining a slurry C2 (water) having a solid content of 10% by mass. Solvent).

[Production Example D1] (using CNC, defibrating in DMSO, and then chemically modifying)
A fine cellulose DMSO slurry was obtained in the same manner as in Production Example B1, except that the cellulose raw material was changed to 0.6 parts by mass of linter pulp and 0.4 parts by mass of CNC. Subsequently, fine cellulose was acetylated in the same manner as in Production Example C1 to obtain 35 parts by mass of a slurry D1 (DMSO solvent) having a solid content of 2.9% by mass.

[Production Example D2] (CNC combined, defibration in DMSO, then chemical modification, then solvent replacement with water)
After 30 parts by mass of pure water was added to the slurry D1 and sufficiently stirred, the mixture was put into a dehydrator and concentrated. The washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water is repeated a total of 5 times to remove the unreacted reagent solvent and the like, thereby obtaining a slurry D2 (water) having a solid content of 10% by mass. Solvent) was obtained in an amount of 10 parts by mass.

[Production Example E1] (using wood pulp, chemical modification simultaneously with defibration in DMSO)
Except that the cellulose raw material was changed to 1 part by mass of softwood bleached kraft pulp NBKP, 3.2 parts by mass of vinyl acetate and 0.49 parts by mass of sodium hydrogen carbonate were added immediately before bead milling, and the circulation operation was performed at 40 ° C. for 180 minutes. The same treatment as in Production Example B1 was carried out to obtain 35 parts by mass of a slurry E1 (DMSO solvent) having a solid content of 2.9% by mass (1 part by mass of fine cellulose).

[Production Example E2] (using wood pulp, chemical modification simultaneously with fibrillation in DMSO, and then solvent replacement with water)
After adding 30 parts by mass of pure water to the slurry E1 and sufficiently stirring, the mixture was put into a dehydrator and concentrated. The washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water is repeated a total of 5 times to remove the unreacted reagent solvent and the like, thereby obtaining a slurry E2 (water) having a solid content of 10% by mass. Solvent) was obtained in an amount of 10 parts by mass.

<Production of composite particles>
The composite particles and single particles of only fine cellulose used in Examples A1 to A9 and Comparative Examples A1 to A8 were produced according to the compositions of Table 2 by the methods of Production Examples V to Z described below.

[Production Example V]
After putting all of the slurries B1, C1, D1, and E1 into explosion-proof disperser tanks, cellulose derivative powder was added, and the mixture was stirred for 10 minutes at a rotation speed of 100 rpm at room temperature to completely dissolve the cellulose derivatives. Subsequently, while stirring 30 parts by mass of pure water in another explosion-proof type disperser tank at 200 rpm, the entire amount of the slurry was dropped at a rate of 1 L / min. The derivative was precipitated (precipitation step). A liquid component was removed from the obtained aqueous dispersion by a dehydrator. Thereafter, 30 parts by mass of pure water was added, and the mixture was sufficiently stirred. A washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water was repeated a total of five times to remove DMSO, thereby producing 10 parts by mass of water-containing composite particles (solid content ratio). 10% by mass).

[Production Example W]
With respect to the slurries B1, C1, and D1, the total amount of the water-containing composite particles produced in Production Example V was vacuum-dried at 50 rpm at 40 ° C. using a planetary mixer (Hibismix 2P-1) to obtain dried composite particles. Obtained.

[Production Example X]
Nylon 6 powder was added to the slurry C2, and the mixture was kneaded with a planetary mixer at a rotation speed of 50 rpm at room temperature for 2 hours, followed by vacuum drying at 40 ° C. to obtain dried composite particles.

[Production Example Y]
The slurries B2, C2, D2, and E2 were dried at 50 rpm at 40 ° C. under vacuum using a planetary mixer without adding any thermoplastic resin powder, to obtain single particles.

[Production Example Z]
The cellulose derivative powder is added to the slurry A, the mixture is kneaded with a planetary mixer at a rotation speed of 50 rpm at room temperature for 2 hours, and dried at 40 ° C. under vacuum to concentrate to a solid content of 30% by mass. Was manufactured.

<Measurement method-fine cellulose>
[Preparation of measurement sample]
Table 1 shows the physical properties of the fine celluloses of Production Examples A, B1, C1, C2, D1, and E1. These physical properties were evaluated using the aqueous slurries of Production Examples A, B1, C1, C2, D1, and E1 and the porous sheet prepared by the following method.
First, 4 g of a fine cellulose concentrated slurry or a chemically modified fine cellulose concentrated slurry having a solid concentration of 10% by mass was dispersed in 96 g of tert-butanol, and further treated with a homogenizer (trade name "Ultra Turrax T18" manufactured by IKA): The dispersion treatment was performed at a rotation speed of 25,000 rpm for 5 minutes until there was no aggregate (solid content concentration: 0.4% by mass). 100 g of the obtained tert-butanol dispersion was filtered on filter paper (5C, Advantech, diameter 90 mm). The wet paper obtained by the filtration is in a state where the filter paper is stuck, and is sandwiched between two filter papers of 150 mm in diameter, and the circumference of the wet paper is suppressed by a cylindrical weight (inner diameter 110 mm) of about 300 g. Heating was performed at 150 ° C. for 5 minutes to obtain a dried sheet. At this time, a sheet having an air permeability resistance of 100 sec / 100 ml or less per 10 g / m ^{2 of} sheet weight was defined as a porous sheet and used as a measurement sample.
After measuring the basis weight W (g / m ² ) of the sample which was allowed to stand for 1 day in an environment of 23 ° C. and 50% RH, an Oken-type air resistance tester (model EG01, manufactured by Asahi Seiko Co., Ltd.) was used. The air resistance R (sec / 100 ml) was measured. At this time, a value per 10 g / m ² basis weight was calculated according to the following equation.
Permeation resistance per unit weight of 10 g / m ² (sec / 100 ml) = R / W × 10

[Number average diameter]
The water slurries and cellulose whiskers in Production Examples A, B1, C1, C2, D1, and E1 were diluted to 0.01% by mass with tert-butanol, and a high-shear homogenizer (trade name “Ultra Turrax T18” manufactured by IKA) was used. Processing conditions: Dispersed at 25,000 rpm for 5 minutes, cast on mica and air-dried to obtain a measurement sample, which was measured with a high-resolution scanning microscope. Specifically, the diameter and length of 100 randomly selected microcellulose were measured in an observation visual field whose magnification was adjusted so that 100 microcellulose were observed. Subsequently, the average value of the diameters and lengths of the obtained 100 pieces was defined as the number average diameter and number average length of the fine cellulose. L / D was calculated from the number average diameter and the number average length.

[Crystallinity]
The X-ray diffraction measurement of the porous sheet was performed, and the crystallinity was calculated from the following equation.
Crystallinity (%) = [I ₍₂₀₀₎ -I _(amorphous) ] / I ₍₂₀₀₎ × 100
I ₍₂₀₀₎ : Diffraction peak intensity due to 200 planes (2θ = 22.5 °) in cellulose I-type crystal I _(amorphous) : Halo peak intensity due to amorphous _{phase in} cellulose I-type crystal Peak intensity at the low angle side of 0.5 ° (2θ = 18.0 °)

(X-ray diffraction measurement conditions)
Equipment MiniFlex (manufactured by Rigaku Corporation)
Operation axis 2θ / θ
Source CuKα
Measurement method Continuous type Voltage 40kV
Current 15mA
Starting angle 2θ = 5 °
End angle 2θ = 30 °
Sampling width 0.020 °
Scan speed 2.0 ° / min
Sample: Paste porous sheet on sample holder

[IR index, DS]
The infrared spectrum of the porous sheet by the ATR-IR method was measured with a Fourier transform infrared spectrophotometer (FT / IR-6200 manufactured by JASCO). The infrared spectrum was measured under the following conditions.
Number of accumulation: 64 times,
Wave number resolution: 4 cm ^-1 ,
Measurement wave number range: 4000 to 600 cm ^-1 ,
ATR crystal: diamond,
Incident angle: 45 °
From the obtained IR spectrum, the IR index was calculated by the following formula (1):
IR index = H1730 / H1030 (1)
It calculated according to. In the formula, H1730 and H1030 are absorbances at 1730 cm ⁻¹ and 1030 cm ⁻¹ (absorption band of cellulose backbone chain CO stretching vibration). Here, the line connecting 1900 cm ^-1 and 1500 cm ^-1 and the line connecting 800 cm ^-1 and 1500 cm ^-1 are used as the baseline, and the absorbance is defined as the absorbance of which is 0.
Then, the average degree of substitution (DS) was calculated from the IR index according to the following equation (2).
DS = 4.13 × IR index (2)

<Measurement method-composite particles>
[DMSO dispersion viscosity, thixotropic index (TI)]
A predetermined amount of composite particles was added to DMSO so that the fine cellulose was 1% by mass, to prepare 100 ml of a DMSO dispersion containing the composite particles. Subsequently, the mixture was stirred with a magnetic stirrer at a rotation speed of 1200 rpm for 1 hour or more. After confirming that the liquid temperature was 25 ° C., a part of the dispersion during stirring was taken, and the viscosity was immediately measured with a rheometer (TA Instruments, product name: ARES) in a double cylindrical geometry. . The temperature of the apparatus was previously adjusted to 25 ° C.
As a measurement condition, a cycle in which the shear rate was decreased from 100 s ^-1 to 1 s ^-1 over 100 seconds and then increased to 100 s ^-1 over 100 seconds was repeated twice. And finally, it was lowered from 100 s ^-1 to 1 s ^-1 over 100 seconds, and viscosity data was acquired every 1 second. The viscosities at a shear rate of 10 s ^-1 and 100 s ^-1 were defined as η ₁₀ and η ₁₀₀ , respectively.
The thixotropic index TI was calculated according to the following equation.
TI = η ₁₀ / η ₁₀₀

[Composite particle-median particle size]
200 ml of an aqueous dispersion containing 1% by mass of the composite particles was prepared. Subsequently, the mixture was treated with a household mixer (Panasonic, fiber mixer MX-X701) for 1 minute. Then, using a laser diffraction type particle size distribution analyzer (Beckman Coulter, LSI3320), the average value in four measurements was taken as the median particle size.

<Measurement method-resin composition>
A multipurpose test piece based on ISO294-3 was molded using an injection molding machine.
Polyamide-based material: Conditions according to JIS K6920-2 Polypropylene-based material: Conditions according to JIS K6921-2

[Tensile breaking strength, tensile breaking elongation, flexural modulus]
For each of the resin composition and the base resin alone, the tensile strength at break and tensile elongation at break were measured in accordance with ISO527, and the flexural modulus was measured in accordance with ISO179.
In addition, since the polyamide-based material changes due to moisture absorption, it was stored in an aluminum moisture-proof bag immediately after molding to suppress moisture absorption.

[Linear expansion coefficient]
The resin composite or the resin was cut into a 3 mm width × 25 mm length to obtain a measurement sample. Using a TMA6100 type device manufactured by SII, in a tensile mode, the distance between the chucks was 10 mm, the load was 5 g, and the temperature was from 5 ° C./min. And then up to 25 ° C at 5 ° C / min. At 25 ° C to 120 ° C again at 5 ° C / min. The temperature rose. At this time, the average linear thermal expansion coefficient between 30 ° C. and 100 ° C. at the time of the second heating was measured.

[Storage modulus]
The resin composite pellets were melted by an injection molding machine at 260 ° C. for PA6 and 160 ° C. for PP to prepare dumbbell-shaped test pieces conforming to JIS K7127. The equipment and measurement conditions used for storage elastic modulus measurement are as follows.
Equipment: GABO Eplexer Measurement mode: Tensile Frequency: 10 Hz
Temperature range: -130 ° C to 150 ° C
Heating rate: 3 ° C./min Measurement atmosphere: Nitrogen storage modulus change was calculated according to the following equation.
Change in storage modulus = storage modulus at low temperature / storage modulus at high temperature The low / high temperature was set to 0 ° C./150° C. for PA6, and −50 ° C./100° C. for PP. Generally, the storage elastic modulus decreases as the temperature increases, so that the change in the storage elastic modulus becomes 1 or more. The closer this value is to 1, the smaller the change in storage modulus at high temperatures and the better the heat resistance (high temperature rigidity).

Regarding the five physical properties (tensile rupture strength, tensile rupture elongation, flexural modulus, linear expansion coefficient, change in storage modulus) of the resin composition measured by the above-described measuring method, only fine cellulose was used instead of the composite particles. The ratio of the value of the resin composition formed using the composite particles to the value of the formed resin composition was determined.

<Examples A1 to A9 and Comparative Examples A1 to A8>
In the production of the resin composition, a twin-screw extruder (TEM-26SS extruder manufactured by Toshiba Machine Co., Ltd. (L / D = 48, with a vacuum vent)) is used. The cylinder temperature was set to ° C. The composite particles and the base resin were mixed in the proportions shown in Table 3 and supplied from a quantitative feeder. The mixture was melt-kneaded under the conditions of an extrusion rate of 15 kg / hour, a screw rotation speed of 250 rpm, vacuum deaeration, and a strand from the die. Extruded. The strand was quenched by a strand bath and cut by a strand cutter to obtain a pellet-shaped resin composition.

<< Example B >>
<Manufacture of fine cellulose fiber (hereinafter may be abbreviated as CNF)>
[Production Example A]
3 parts by mass of cotton linter pulp were immersed in 27 parts by mass of water and heat-treated at 130 ° C. for 4 hours in an autoclave. The obtained swollen pulp was washed with water to obtain a purified pulp containing water (30 parts by mass). Subsequently, 170 parts by mass of water was added to 30 parts by mass of purified pulp containing water and dispersed in water (solid content ratio: 1.5% by mass), and SDR14 type laboratory refiner (manufactured by Aikawa Tekko Co., Ltd.) as a disc refiner ( The aqueous dispersion was beaten for 20 minutes with a clearance between disks of 1 mm using a pressurized DISK method. Subsequently, thorough beating was performed under the condition that the clearance was reduced to a level close to almost zero to obtain a beaten water dispersion (solid content concentration: 1.5% by mass). The obtained beaten water dispersion was directly subjected to micronization treatment 15 times under an operating pressure of 100 MPa using a high-pressure homogenizer (NSO15H manufactured by Niro Soavi Co., Ltd. (Italy)) to obtain a fine cellulose slurry (solid content: 1). 0.5% by mass). Then, the mixture was concentrated to a solid content of 10% by mass with a dehydrator to obtain 30 parts by mass of slurry a (aqueous solvent).

[Production Example B1]
One part by mass of the cotton linter pulp was stirred at 500 rpm for 1 hour at room temperature in 30 parts by mass of dimethyl sulfoxide (DMSO) using a uniaxial stirrer (DKV-1 φ125 mm dissolver manufactured by Imex). Subsequently, the mixture was fed to a bead mill (NVM-1.5, manufactured by IMEX Co., Ltd.) using a hose pump, and circulated with only DMSO for 180 minutes to obtain 31 parts by mass of a slurry b1 (DMSO solvent).
During the circulation operation, the rotation speed of the bead mill was 2500 rpm, the peripheral speed was 12 m / s, the beads used were made of zirconia, Φ2.0 mm, and the filling rate was 70% (the slit gap of the bead mill was 0.6 mm). During the circulation operation, the slurry temperature was controlled at 40 ° C. by a chiller in order to absorb heat generated by friction.

[Production Example B2]
After adding 30 parts by mass of pure water to the slurry b1 and sufficiently stirring, the mixture was put into a dehydrator and concentrated. A washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water was repeated a total of 5 times to remove the unreacted reagent solvent and the like, and to obtain a slurry b2 (water) having a solid content of 10% by mass. Solvent) was obtained in an amount of 10 parts by mass.

[Production Example C1]
After putting the slurry b1 into the explosion-proof disperser tank, 3.2 parts by mass of vinyl acetate and 0.49 parts by mass of sodium hydrogen carbonate were added, the temperature in the tank was set to 70 ° C., and the mixture was stirred for 120 minutes to obtain a slurry c1 (DMSO Solvent) was obtained in an amount of 35 parts by mass.

[Production Example C2]
After adding 30 parts by mass of pure water to the slurry c1 and sufficiently stirring, the mixture was placed in a dehydrator and concentrated. A washing operation of dispersing, stirring, and concentrating the obtained wet cake again in 30 parts by mass of pure water is repeated a total of 5 times to remove unreacted reagent solvents and the like, thereby obtaining a slurry c2 (water) having a solid content of 10% by mass. Solvent) was obtained in an amount of 10 parts by mass.

<Production of cellulose derivative composite>
The cellulose derivative composites used in Examples B1 to B23 and Comparative Examples B1 to B6 were produced according to the compositions of Table 5 by the methods of Production Examples W to Z below.

[Production Examples W1 to W5]
The cellulose derivative powder CAB or CAP is added to the slurry a, and the mixture is stirred for 10 minutes using a planetary mixer (manufactured by Primix, Hibismix 2P-1) at a rotation speed of 50 rpm at room temperature to obtain a composite W1 to W5 containing water. Was manufactured.

[Production Example W-6]
The slurry a was vacuum-dried at 40 rpm at 50 rpm using a planetary mixer to obtain a fine cellulose fiber powder W6.

[Production Example X-1]
The cellulose derivative powder CAB was added to the slurry b2, and the mixture was stirred at a rotation speed of 50 rpm at room temperature for 10 minutes using a planetary mixer, and further dried at a rotation speed of 50 rpm at 40 ° C. under vacuum to produce a dry composite X1.

[Production Example X-2]
The slurry b2 was vacuum-dried at 50 rpm at 40 ° C. using a planetary mixer to obtain a chemically modified fine cellulose fiber powder X2.

[Production Example Y]
After putting the entire amount of the slurry b1 into the explosion-proof disperser tank, the cellulose derivative powder CAB or CAP was added, and the mixture was stirred for 10 minutes at a rotation speed of 100 rpm at room temperature to completely dissolve the cellulose derivative. Subsequently, while stirring 30 parts by mass of pure water in another explosion-proof disperser tank at 200 rpm, the slurry was dripped in a total amount of 1 L / min at a rate of 1 L / min. The derivative was precipitated (precipitation step). A liquid component was removed from the obtained aqueous dispersion by a dehydrator. Thereafter, 30 parts by mass of pure water was added, and the mixture was sufficiently stirred. The obtained wet cake is again dispersed in 30 parts by mass of pure water, and the washing operation of stirring and concentrating is repeated a total of 5 times to remove DMSO, and to remove 10 parts by mass of the water-containing composite Y (solid content: 10% by mass). ) Manufactured.

[Production Examples Z-1 to Z-5]
A water-containing composite was produced in the same manner as in Production Example Y-1 except that the slurry used was changed to the slurry c1, and then dried at 50 rpm at 40 ° C. under vacuum using a planetary mixer to obtain a dry composite. The bodies Z1 to Z5 were produced.

[Production Example Z-6]
After producing a composite containing water in the same manner as in Production Examples Z-1 to Z-5, cellulose whisker powder was added, and the mixture was dried under vacuum at 50 rpm at 40 ° C. using a planetary mixer to obtain cellulose whiskers. To produce a dry composite Z6.

[Production Example Z-7]
The slurry c2 was vacuum-dried using a planetary mixer at a rotation speed of 50 rpm at 40 ° C. to obtain a chemically modified fine cellulose fiber powder Z7.

<Measurement method-fine cellulose fiber>
[Preparation of measurement sample]
A measurement sample was prepared in the same procedure as in Example A using 4 g of a concentrated cellulose fiber or a chemically modified fine cellulose fiber concentrated slurry having a solid content of 10% by mass.
Table 4 shows the physical properties of the fine cellulose fibers and the chemically modified fine cellulose fibers in Examples and Comparative Examples. These physical properties were evaluated using the aqueous slurries of Production Examples A, B2, and C2, and the porous sheet produced by the following method. The fine cellulose fibers / chemically modified fine cellulose fibers obtained in Production Examples B1 and C1 were regarded as equivalent to those obtained in Production Examples B2 and C2.

[Fiber diameter]
After drying about 0.2 g of the porous sheet sample under vacuum at 120 ° C. for 2 hours using a specific surface area / pore distribution measuring apparatus (Nova-4200e, manufactured by Cantachrome Instruments), the boiling point of liquid nitrogen was measured. Was measured at five points in the range where the relative vapor pressure (P / P ₀ ) was 0.05 or more and 0.2 or less (multipoint method), and the BET specific surface area (m ² / G) was calculated. Then, the equivalent diameter of the specific surface area was calculated from the specific surface area by the following formula, and was defined as the fiber diameter D of the fine cellulose fiber.
D (nm) = 2667 / specific surface area (m ² / g)

[Crystallinity]
Evaluation was performed in the same manner as in Example A.

[IR index, DS]
Evaluation was performed in the same manner as in Example A.

[Thermal decomposition start temperature]
The thermal analysis of the porous sheet was evaluated by the following measurement method.
Equipment: Thermo plus EVO2 manufactured by Rigaku
Sample: A circular sheet cut from a porous sheet was placed in an aluminum sample pan in an amount of 10 mg.
Sample size: 10mg
Measurement conditions: In a nitrogen flow of 100 ml / min, the temperature was raised from room temperature to 150 ° C. at a rate of 10 ° C./min, kept at 150 ° C. for 1 hour, and then cooled to 30 ° C. Subsequently, the temperature was raised from 30 ° C. to 450 ° C. at a rate of 10 ° C./min.
T _D calculation method: Determined from a graph in which the horizontal axis represents temperature and the vertical axis represents weight retention%. Starting from the weight of the porous sheet at 150 ° C. (in a state where moisture is almost removed) (weight loss: 0 wt%), the temperature is further increased, and the temperature when the weight is reduced by 1 wt% and the temperature when the weight is reduced by 2 wt% To get a straight line. The temperature at the point where this straight line intersected with the horizontal line (base line) passing through the starting point where the weight loss amount was 0 wt% was defined as the thermal decomposition onset temperature (T _D ).

[1 wt% weight loss temperature]
1 wt% weight loss temperature calculation method: The temperature at the time of 1 wt% weight reduction used in the above Td calculation was defined as 1 wt% weight loss temperature.

[250 ° C weight loss rate]
Equipment: Thermo plus EVO2 manufactured by Rigaku
Sample: A circular sheet cut from a porous sheet was placed in an aluminum sample pan in an amount of 10 mg.
Sample size: 10mg
Measurement conditions: In a nitrogen flow of 100 ml / min, the temperature was raised from room temperature to 150 ° C. at a rate of 10 ° C./min, maintained at 150 ° C. for 1 hour, and then increased from 150 ° C. to 250 ° C. at a rate of 10 ° C. / Min, and kept at 250 ° C. for 2 hours.
Method for calculating weight change rate at 250 ° C .: Starting from the weight W0 at the time when the temperature reached 250 ° C., the weight after holding at 250 ° C. for 2 hours as W1 was determined by the following formula.
250 ° C weight change rate (%): (W1-W0) / W0 × 100

[Polymerization degree]
It was measured by the reduced specific viscosity method using a copper ethylenediamine solution specified in the crystalline cellulose confirmation test (3) of “14th Revised Japanese Pharmacopoeia” (published by Hirokawa Shoten).

[Weight average molecular weight (Mw), number average molecular weight (Mn)]
0.88 g of the porous sheet was weighed, cut into small pieces with scissors, stirred gently, added with 20 mL of pure water, and allowed to stand for one day. Next, water and solids were separated by centrifugation. Subsequently, 20 mL of acetone was added, and the mixture was stirred gently and allowed to stand for 1 day. Next, acetone and solid content were separated by centrifugation. Subsequently, 20 mL of N, N-dimethylacetamide was added, and the mixture was stirred gently and allowed to stand for 1 day. After N, N-dimethylacetamide and the solid content were separated again by centrifugation, 20 mL of N, N-dimethylacetamide was added, and the mixture was lightly stirred and allowed to stand for 1 day. The N, N-dimethylacetamide and the solid content were separated by centrifugation, and 19.2 g of an N, N-dimethylacetamide solution prepared by adjusting the solid content to 8% by mass of lithium chloride was added, followed by stirring with a stirrer. Dissolution was confirmed visually. The solution in which cellulose was dissolved was filtered through a 0.45 μm filter, and the filtrate was used as a sample for gel permeation chromatography. The equipment used and the measurement conditions are as follows.
Equipment: Tosoh Corporation HLC-8120
Column: TSKgel SuperAWM-H (6.0 mm ID × 15 cm) × 2 Detector: RI detector Eluent: N, N-dimethylacetamide (lithium chloride 0.2%)
Flow rate: 0.6 mL / min Calibration curve: Pullulan conversion

[Average content of acid-insoluble components]
The acid-insoluble component was quantified by the Clerson method described in Non-Patent Document (Wood Science Experiment Manual, edited by The Japan Wood Research Society, pp. 92-97, 2000) for fine cellulose fiber raw materials. The raw material of the absolutely dried fine cellulose fiber is precisely weighed, put in a predetermined container, added with 72% by mass of concentrated sulfuric acid, and appropriately pressed with a glass rod so that the contents become uniform. Was dissolved in the acid solution. After allowing to cool, the content was filtered through a glass fiber filter paper to obtain an acid-insoluble component as a residue. The acid-insoluble component content was calculated from the weight of the acid-insoluble component, and the number average of the acid-insoluble component content calculated for the three samples was defined as the acid-insoluble component average content.

[Average alkali-soluble polysaccharide content]
The content of alkali-soluble polysaccharide is determined by the method described in Non-Patent Document (Wood Science Experiment Manual, edited by The Wood Science Society of Japan, pp. 92-97, 2000) for the raw material of fine cellulose fiber (Wise method). From the α-cellulose content. The alkali-soluble polysaccharide content was calculated three times for one sample, and the number average of the calculated alkali-soluble polysaccharide content was defined as the average alkali-soluble polysaccharide content of the fine cellulose fibers.

<Measurement method-resin composition>
[Tensile yield strength increase ratio]
A multipurpose test piece based on ISO294-3 was molded using an injection molding machine.
As for the polypropylene-based material, the test was performed under the conditions in accordance with JIS K6821-2.
As for the polyamide-based material, the test was performed under the conditions in accordance with JIS K6920-2.
For each of the raw resin (namely, the thermoplastic resin alone) and the resin composition (namely, the fine cellulose fiber-containing resin composition), the tensile yield strength was measured in accordance with ISO527, and the tensile yield strength of the fine cellulose fiber-containing resin composition was measured. Was divided by the tensile yield strength of the raw resin to calculate a tensile yield strength increase ratio.
In addition, since the polyamide-based material changes due to moisture absorption, it was stored in an aluminum moisture-proof bag immediately after molding to suppress moisture absorption.

[Coefficient of variation in tensile breaking strength]
Using a multipurpose test piece conforming to ISO 294-3, the tensile strength at break was measured at number 15 in accordance with ISO 527, and a coefficient of variation (CV) was calculated based on the following data based on the obtained data. did.
CV = (σ / μ) × 100
Here, σ represents a standard deviation, and μ represents an arithmetic mean of tensile breaking strength.

[Linear expansion coefficient]
Annealing before measurement and measurement were performed in the same procedure as in Example A.

[Expansion of molded piece]
As an evaluation method corresponding to the dimensional change of the actual molded body, the expansion coefficient of the molded piece was measured.
Specifically, the length of the molded piece in the environment of 23 ° C. and 50% RH was measured using a fully-filled molded piece molded at the time of fluidity evaluation, and then the test piece was placed in an oven at 60 ° C. It was placed in the container, and measured in the length direction immediately after being taken out after 30 minutes, and the dimensional change was calculated. The measurement was carried out at n = 5, and the arithmetic average thereof was defined as a molded piece expansion coefficient.

[Fender defect rate]
Using the pellets obtained in the example, the cylinder temperature of an injection molding machine with a maximum clamping pressure of 4000 tons was set to 250 ° C., and a predetermined mold capable of molding a fender having the shape shown in the schematic diagram of FIG. (Cavity volume: about 1400 cm ³ , average thickness: 2 mm, projected area: about 7000 cm ² , number of gates: 5 gates, hot runner: a runner is shown in FIG. 6 to clarify the runner position of the molded body. (The relative position 1 of the (hot runner) is shown.), The mold temperature was set to 60 ° C., and 20 fenders were formed.

置き The obtained fender was placed on the floor, and a bag containing 5 kg of sand was dropped from the height of about 50 cm to the center of the fender, and the state of destruction of the fender was confirmed. The number destroyed out of 20 was counted.

[Coefficient of linear expansion coefficient variation]
Using the fender used in the measurement of the defect rate of the fender, cut out approximately 10 mm square from the positions of (1) to (10) in FIG. 7 and 10 small pieces of about 10 mm in length, about 10 mm in width, and 2 mm in thickness. Flat specimens were collected. In addition, (1) to (3) are the vicinity of the molded body gate, (4) to (7) are the flow end portions of the molded body, and (8) to (10) are the central part of the molded body.
The obtained small flat plate test piece was further cut into a rectangular parallelepiped sample for measurement having a length of 4 mm, a width of 2 mm, and a length of 4 mm using a precision cut saw. The lateral portion of the rectangular parallelepiped sample at this time is in the thickness direction of the fender.
Prior to the measurement, the sample was left standing at 120 ° C. for 5 hours to perform annealing, thereby obtaining a sample for measurement. The obtained sample was measured in a measurement temperature range of −10 ° C. to + 80 ° C. in accordance with ISO 11359-2, and an expansion coefficient between 0 ° C. and 60 ° C. was calculated, and a total of 10 measurement results were obtained. Was. The coefficient of variation (CV) was calculated based on the following measurement data based on the ten measurement data.
CV = (σ / μ) × 100
Here, σ represents a standard deviation, and μ represents an arithmetic mean of tensile breaking strength.

<Examples B1 to B21, Comparative Examples B1 to B4>
The polyamide, the cellulose derivative composite, and the cellulose whisker were mixed such that the fine cellulose fiber or the chemically modified fine cellulose fiber, the cellulose derivative, the cellulose whisker, and the polyamide had the ratios shown in Tables 6 to 8, and were mixed with Toshiba Machine Co., Ltd. ), The mixture was melt-kneaded at a screw rotation speed of 350 rpm and a discharge rate of 140 kg / hr, devolatilized in vacuum, extruded from a die into a strand, cooled in a water bath, and pelletized. The pellet had a columnar shape, a diameter of 2.3 mm and a length of 5 mm.
These were evaluated based on the above-mentioned evaluation method.

判 It can be seen that the defect rate of the fender and the expansion rate of the molded piece are significantly improved by the polyamide resin containing not only the fine cellulose fiber or the chemically modified fine cellulose fiber but also the cellulose derivative. This tendency is confirmed even when cellulose whiskers are added.

<Examples B22 to B23, Comparative Examples B5 to B6>
Pellets were obtained using the procedure of Example B1 with the composition shown in Table 9 except that the resin was changed to polypropylene or acid-modified polypropylene, or cellulose whiskers were added.

判 It can be seen that the defect rate of the fender and the expansion rate of the molded piece are greatly improved by the fact that not only the fine cellulose fiber or the chemically modified fine cellulose fiber but also the cellulose derivative is contained in the polypropylene resin. Further, by using the acid-modified polypropylene in combination, the affinity between the thermoplastic resin and the fine cellulose fibers is improved, the dispersibility of the fine cellulose fibers in the resin is also improved, and the physical properties are generally improved.

<< Example C >>
<Evaluation method>
[Fiber diameter D, fiber length L / fiber diameter D of cellulose fiber]
A part of the cellulose fiber slurry is repeatedly washed with pure water to obtain a cellulose fiber water slurry. The cellulose fiber water slurry was diluted with tert-butanol to 0.01% by mass, and treated with a high shear homogenizer (trade name “Ultra Turrax T18” manufactured by IKA) under the following conditions: 25,000 rpm for 5 minutes. A sample that is dispersed, cast on mica, and air-dried is used as a measurement sample, and measured by a high-resolution scanning microscope. Specifically, the diameter D and the length L of 100 randomly selected microcellulose are measured in an observation visual field whose magnification is adjusted so that 100 or more microcellulose are observed. Subsequently, the average value of the obtained 100 diameters D is defined as the number average diameter of the fine cellulose. In this embodiment, when the number average diameter is 20 nm or more and less than 450 nm, it is defined as a cellulose nanofiber (CNF) described later. The L / D of 100 fine celluloses is calculated, and the average value is defined as the average L / D of the fine cellulose. In this example, when the average L / D is 30 or more and less than 1000, it is defined as a cellulose nanofiber (CNF) described later. The fiber diameter D and L / D of the cellulose fiber are also preserved in the fiber diameter and L / D of the chemically modified cellulose fiber, and even when the cellulose fiber is chemically modified, the fine cellulose before the chemical modification is removed. It should be evaluated.

<Structure and extrusion of extruder>
[Aspect 1]
L / D is 60, there are 13 cylinder blocks, cylinder 1 is the main throat, cylinder 4 (L / D = 17 position), cylinder 8 (L / D = 35 position) and cylinder 10 ( A twin-screw extruder with a screw diameter of 30 mm capable of installing a feeder that can be forcibly pushed from the extrusion side at the position of L / D = 45 is prepared, and can be forcibly pushed into the cylinder 4 (the position of L / D = 18). The feeder is installed, and the cylinder 8 (the position of L / D = 36) and the cylinder 10 (the position of L / D = 45) are closed. In addition, a vent port is provided at the upper part of the cylinder 12 so that vacuum suction can be performed, and vacuum suction is performed.

The screw configuration of the extruder is such that the

cylinders

1 and 2 are transport zones composed of only transport screws, and one clockwise kneading disk (feed type kneading disk: hereinafter simply referred to as RKD) is provided on the cylinder 3 from the upstream side. 2) Neutral kneading disk (non-conveying type kneading disk: hereinafter may be simply referred to as NKD), 1 counterclockwise screw (reverse feed type kneading disk: hereinafter) , May be simply referred to as RKD.). The cylinders 4 to 8 are used as a transport zone, and two NKD and one LKD are arranged in the cylinder 9 in this order. The subsequent cylinder 10 is a transport zone, two NKDs and one LKD are arranged in this order on the cylinder 11, and the cylinders 12 and 13 are transport zones.

シリンダー Cylinder temperature of this extruder is set to 200 ° C. for cylinder 1 with water cooling, cylinder 2 for 160 ° C. and cylinder 3 to die when resin is PP. When the resin is PA6, the cylinder 1 is water-cooled, the cylinder 2 is set at 230 ° C., and the cylinders 3 to dies are set at 250 ° C.

From the main throat, a resin is supplied from the addition port of the cylinder 4 to the composite particles at a ratio shown in Tables 10 and 11, melt kneading is performed at a screw rotation speed of the extruder of 250 rpm, extruded into a strand, and water-cooled. Pelletize. The obtained pellets are subjected to vacuum drying for 12 hours using a vacuum dryer set at 80 ° C. in order to reduce moisture.

[Aspect 2]
A feeder that can be forcibly pushed is installed in the cylinder 8 (L / D = 35), the cylinder 4 (L / D = 17) and the cylinder 10 (L / D = 45) are closed, and the cylinder 8 is closed. Preparations were made in the same manner as in Embodiment 1, except that the composite particles were supplied from.

[Aspect 3]
A feeder that can be forcibly pushed is installed in the cylinder 10 (L / D = 45), the cylinder 4 (L / D = 17) and the cylinder 8 (L / D = 35) are closed, and the cylinder 10 (L / D = 35) is closed. Preparations were made in the same manner as in Embodiment 1, except that the composite particles were supplied from.

[Aspect 4]
In the extruder of the first embodiment, the forcible push-in port is closed from the extrusion side of the

cylinders

4, 8, and 10, and the screw configuration is such that the cylinders 1 to 8 are formed as a conveyance zone composed of only conveyance screws, and two cylinders are provided in the cylinder 9. NKD and one LKD are arranged in this order. The subsequent cylinder 10 serves as a transfer zone, two NKDs and one subsequent LKD are arranged on the cylinder 11 in this order, and the cylinders 12 and 13 serve as transfer zones. Further, a vent port is provided in the upper portion of the cylinder 12 so that vacuum suction can be performed, and vacuum suction is performed. All preparations are made in the same manner as in Embodiment 1, except that a possible feeder can be installed.

Both the resin and the composite particles are supplied from the main throat at the ratios shown in Tables 10 and 11, melt-kneaded at a screw rotation speed of the extruder of 250 rpm, extruded into strands, water-cooled, and pelletized. The obtained pellets are subjected to vacuum drying for 12 hours using a vacuum dryer set at 80 ° C. in order to reduce moisture. At this time, the resin and the composite particles are supplied from different supply devices from the main throat.

<Cellulose whisker>
The same as in Example A is used.

<Production of cellulose nanofiber (CNF) slurry>
1 part by weight of cotton linter pulp is mixed with 10 to 50 parts by weight of dimethyl sulfoxide (DMSO) at 200 to 700 rpm for 0.5 to 2 hours at room temperature using a uniaxial stirrer (DKV-1 φ125 mm dissolver manufactured by Imex). And stir. Subsequently, the mixture is fed to a bead mill (NVM-1.5, manufactured by IMEX Co., Ltd.) using a hose pump, and circulated for 1 to 3 hours with only DMSO to obtain a fine cellulose fiber slurry.

<Production of chemically modified fine cellulose slurry>
After introducing the obtained fine cellulose fiber slurry into a disperser tank, vinyl acetate (VA) and sodium bicarbonate are added at a mass ratio capable of sufficiently acetylating hydroxyl groups of glucose, and the temperature in the tank is adjusted to 30 to 60 ° C. Stirring is performed for 60 to 180 minutes to obtain a chemically modified fine cellulose slurry. When cellulose whiskers are added, they are added at this stage, and acetylation is performed at the same time. By the above procedure, a chemically modified fine cellulose slurry is obtained.

<Production of composite particles>
After the obtained chemically modified fine cellulose slurry is again put into the disperser tank, a predetermined amount of the cellulose derivative powder CAB or CAP is added and stirred at room temperature to completely dissolve the cellulose derivative. Subsequently, the entire slurry is dropped at a constant rate into pure water placed in another explosion-proof disperser tank to precipitate a cellulose derivative (precipitation step). The obtained precipitate is repeatedly washed with pure water to obtain a water slurry of the composite particles. Finally, the composite particle water slurry is vacuum-dried using a planetary mixer (Hibismix 2P-1) to obtain dry composite particles.

<Measurement method>
[Preparation of measurement sample of chemically modified fine cellulose]
A part of the chemically modified fine cellulose slurry is repeatedly washed with pure water to obtain a chemically modified fine cellulose water slurry. Subsequently, the water slurry is dispersed in tert-butanol (solid content: less than 0.4% by mass and moisture content: less than 5% by mass), and further subjected to dispersion treatment with a homogenizer until no aggregates are present. The obtained tert-butanol dispersion is filtered on filter paper (5C, Advantech, diameter 90 mm), and the obtained wet paper is dried by heating to obtain a sheet. A sheet having an air resistance of 100 sec / 100 ml or less per 10 g / m ^{2 of} sheet weight is defined as a porous sheet and used as a measurement sample.

[Crystallinity of chemically modified fine cellulose]
In the same procedure as in Example A, the X-ray diffraction measurement of the porous sheet is performed to calculate the crystallinity. A material having a crystallinity of 55% or more can exhibit good mechanical properties as a filler, and is evaluated as satisfying the requirements in this example.

[Evaluation of degree of chemical modification]
Regarding the degree of chemical modification of the fine cellulose, measurement of an infrared spectrum of the porous sheet by the ATR-IR method and calculation of an IR index are performed in the same procedure as in Example A.
Those having a DS of 0.1 or more and less than 1.6 have been subjected to sufficient chemical modification, and are evaluated as satisfying the requirements in this example.

[Median particle diameter of composite particles]
The measurement is performed in the same procedure as in Example A. Particles having a particle size of 1 μm or more and less than 5000 μm exhibit a stable behavior as a filler when kneaded with a resin, and are evaluated as satisfying the requirements in this example.

[Fluidity (minimum filling pressure)]
The minimum filling pressure is measured as an index of fluidity close to actual molding.
Specifically, an injection molding machine with a mold clamping pressure of 200 tons, a flat plate mold having a film gate in the width direction, a length of 200 mm, a width of 150 mm, and a thickness varying from 3 mm to 1.5 mm at the center of the plate. Attach, set the cylinder temperature and the mold temperature as follows, and measure the bare pressure of the test piece. At this time, the holding pressure is not switched, and the injection pressure and the speed are set to only one stage. Further, after molding by full filling for 20 consecutive shots, the injection pressure is gradually lowered, and the injection pressure immediately before unfilling occurs or immediately before sink occurs is defined as the minimum filling pressure.

Cylinder temperature Polypropylene material 210 ° C
Polyamide material 260 ° C
Mold temperature Polypropylene material 40 ℃
Polyamide material 70 ℃

[Evaluation of resin composition]
1. Colorability Colorability is evaluated as an index of the ease of coloring. In general, when coloring a resin, an operation of adding a dye and pigment necessary for a desired color and then toning is performed after whitening the resin once. The easiness of turning to white greatly affects the colorability. Here, the coloring property is evaluated by measuring the whiteness when a predetermined amount of titanium oxide is added.

A master batch containing 50 parts by mass of titanium oxide was dry-blended at a ratio of 3 parts by mass with respect to 100 parts by mass of pellets containing fine cellulose prepared in the example, and an injection molding machine with a mold clamping pressure of 200 tons was used. Then, using the same flat mold as that used for fluidity (minimum filling pressure), the cylinder temperature and the mold temperature are set as follows, and molding is performed at a pressure sufficient for filling the test piece. As the masterbatch used at this time, a masterbatch using polypropylene as a base resin for a polypropylene material and a polyamide as a base resin for a polyamide material is used.
Cylinder temperature / Mold temperature Polypropylene material 210 ℃ / 40 ℃
Polyamide material 260 ° C / 70 ° C

Using the flat plate portion of the obtained test piece, the L * value was measured with a color difference meter (CM-2002, manufactured by Konica Minolta) under a D65 light and a 10 ° visual field, and the coloring property was evaluated according to the following evaluation criteria. Perform an evaluation.
L * value of flat plate Colorability 85 or more Excellent 80 or more and less than 85 Good 75 or more and less than 80 Acceptable Less than 75 Poor

2. Appearance of molded piece The appearance of a fully filled molded piece molded at the time of fluidity evaluation is evaluated by the following index.
Points Situation 5 The entire surface of the molded piece is glossy 4 The glossy end of the molded piece is not glossy 3 The thin part of the molded piece is not glossy 2 The entire surface of the molded piece is not glossy and slight discoloration can be confirmed.
1 The entire surface of the molded piece is not glossy and considerable discoloration can be confirmed.

3. Odor The odor is evaluated by a sensory test and the following three levels.
A: No odor.
B: There is a slight sugar smell (sweet smell).
C: There is a strong sugar odor.
D: There is a burning smell together with a sugar smell.

The odor test is performed at each of the following stages. (1) resin composition pellets immediately after extrusion, (2) atmosphere during injection molding, (3) molded body immediately after injection molding, (4) molded body one hour after injection molding

4. Linear expansion coefficient Annealing and measurement before measurement are performed in the same procedure as in Example A.
Linear expansion coefficient (ppm / K) Degree of dimensional stability 30 or less Excellent 40 or less Good 50 or less Acceptable More than 50 Poor

5. Tensile yield strength increase ratio In the same procedure as in Example B, molding, measurement, and calculation of the tensile yield strength increase ratio are performed. In addition, since the polyamide-based material changes due to moisture absorption, it is stored in an aluminum moisture-proof bag immediately after molding to suppress moisture absorption.
Increase ratio of tensile yield strength Degree of improvement in resin properties 1.2 or more Excellent 1.1 or more Good 1.0 or more Possible Less than 1.0 Bad

6. Molding piece expansion rate In the same procedure as in Example B, molding, measurement, and calculation of the molding piece expansion rate are performed.
Mold piece expansion rate Degree of expansion suppression 0.2% or less Excellent 0.3% or less Good 0.4% or less Acceptable More than 0.4% Poor

[Examples C1 to C14, Comparative Examples C1 and C2]
Table 10 shows the composition ratio of each component and the evaluation results.
In Examples C1 to C14, the acetylated microcellulose has a fiber diameter D and a fiber length L / fiber diameter D falling under the definition of the cellulose nanofiber described above (excluding the cellulose whiskers used in Example C13). . The crystallinity and average degree of substitution (DS) satisfy the above requirements. The median particle size of the composite particles with the cellulose derivative also satisfies the above requirements.

In Examples C5, C9 and C14, composite particles were supplied from the main throat provided in the cylinder 1 of the extruder, and in Comparative Examples C1 and C2, fine cellulose was not formed into a composite particle with a cellulose derivative.

樹脂 The resin composition of the present invention can be suitably used, for example, in the field of exterior materials for automobiles, which are large parts requiring high strength and low linear expansion and stable performance.

1 Relative positions of runners (hot runners) (1) to (10) Positions where test pieces for measuring the coefficient of variation of linear expansion coefficient were collected

Claims

Composite particles comprising fine cellulose and a thermoplastic resin,
The ratio of fine cellulose in the composite particles is 10% by mass or more and 95% by mass or less,
The viscosity η 10 at a liquid temperature of 25 ° C. and a shear rate of 10 s −1 of a dispersion obtained by dispersing the composite particles in dimethyl sulfoxide so that the concentration of fine cellulose in the dispersion is 1% by mass is 10 mPa · s. s or more.
A thixotropic index (TI), which is a ratio η 10 / η 100 of a viscosity η 10 at a shear rate of 10 s −1 to a viscosity η 100 at a shear rate of 100 s −1 at a liquid temperature of 25 ° C., is 2 or more. The composite particle according to claim 1, which is:
The composite particles according to claim 1 or 2, wherein the median particle size is 1 µm or more and 5000 µm or less.
The composite particles according to any one of claims 1 to 3, wherein the thermoplastic resin is soluble in dimethyl sulfoxide.
The composite particles according to claim 4, wherein the thermoplastic resin is a cellulose derivative.
The composite particles according to claim 5, wherein the weight average molecular weight Mw of the cellulose derivative is 100,000 or less.
複合 The composite particle according to any one of claims 1 to 6, wherein the fine cellulose has a number average diameter of 2 nm or more and less than 1000 nm.
複合 The composite particle according to any one of claims 1 to 6, wherein the fine cellulose has a number average diameter of 2 nm or more and less than 500 nm.
複合 The composite particle according to any one of claims 1 to 6, wherein the fine cellulose has a number average diameter of 10 nm or more and less than 100 nm.
10. The method according to claim 1, wherein the fine cellulose has a weight average molecular weight (Mw) of 100,000 or more and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less. 12. The composite particles according to item.
The composite particles according to any one of claims 1 to 10, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
The composite particles according to any one of claims 1 to 11, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 8% by mass or less.
The composite particles according to any one of claims 1 to 12, wherein a part of the fine cellulose is chemically modified, and the fine cellulose has an I-type crystal structure.
The composite particle according to claim 13, wherein the chemical modification is acetylation.
A method for producing a composite particle according to any one of claims 1 to 14,
A method comprising a powdering step of mixing an aqueous dispersion of fine cellulose and particles of a thermoplastic resin and then drying to collect the composite particles.
The aqueous dispersion of the fine cellulose,
Fibrillation step of performing a fibrillation treatment of cellulose in an organic solvent to obtain a fine cellulose dispersion, and a purification step of substituting water for the organic solvent in the fine cellulose dispersion,
The production method according to claim 15, which is prepared by:
17. The method according to claim 16, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with the defibration step or after the defibration step and before the refining step.
A method for producing a composite particle according to any one of claims 1 to 14,
Preparation of fine cellulose / resin dispersion by adding thermoplastic resin to organic solvent dispersion of fine cellulose to obtain fine cellulose / resin dispersion in which fine cellulose is dispersed in organic solvent and thermoplastic resin is dissolved Process,
A precipitation step of obtaining a composite particle dispersion by mixing the fine cellulose / resin dispersion with a poor solvent for the thermoplastic resin and precipitating composite particles containing the fine cellulose and the thermoplastic resin;
A purification step of replacing the organic solvent in the composite particle dispersion with water to obtain an aqueous dispersion, and a powdering step of drying the aqueous dispersion to collect composite particles,
Including, methods.
19. The method for producing composite particles according to claim 18, wherein the organic solvent dispersion of the fine cellulose is prepared by a defibration step of defibrating cellulose in an organic solvent.
20. The method according to claim 19, further comprising a chemical modification step of performing a chemical modification of the fine cellulose simultaneously with or after the defibration step.
Composite particles comprising fine cellulose and a thermoplastic resin, and a thermoplastic resin different from the thermoplastic resin in the composite particles, a method for producing a resin composition comprising:
A step of forming composite particles by the method according to any one of claims 15 to 20, and a step of kneading the composite particles and a thermoplastic resin different from the thermoplastic resin contained in the composite particles,
Including, methods.
A resin composition comprising the composite particle according to any one of claims 1 to 14 and a base resin.
Thermoplastic resin,
0.1 to 40 parts by mass with respect to 100 parts by mass of the thermoplastic resin, fine cellulose fibers having a fiber diameter of 2 nm to less than 1000 nm, and 1 part by mass to 500 parts by mass with respect to 100 parts by mass of the fine cellulose fibers. Of a cellulose derivative,
A resin composition comprising:
24. The resin composition according to claim 23, wherein the fine cellulose fibers have a weight average molecular weight (Mw) of 100,000 or more, and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less. object.
The resin composition according to claim 23 or 24, wherein the fine cellulose fibers have an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
23. The resin composition according to claim 22, wherein the base resin is a thermoplastic resin.
The thermoplastic resin is selected from the group consisting of polyolefin resins, polyamide resins, polyester resins, polyacetal resins, polyphenylene ether resins, polyphenylene sulfide resins, and mixtures of any two or more of these. Item 27. The resin composition according to any one of items 23 to 26.
The said thermoplastic resin is polypropylene, The melt mass flow rate (MFR) measured at 230 degreeC based on ISO1133 of this polypropylene is 3 g / 10 minutes or more and 30 g / 10 minutes or less. Resin composition.
The thermoplastic resin is a polyamide resin, and a ratio of carboxyl terminal groups to all terminal groups ([COOH] / [total terminal groups]) of the polyamide resin is 0.30 to 0.95. 28. The resin composition according to 27.
The thermoplastic resin is a polyester resin, and a ratio of a carboxyl terminal group to all terminal groups ([COOH] / [all terminal groups]) of the polyester resin is 0.30 to 0.95. 28. The resin composition according to 27.
28. The resin composition according to claim 27, wherein the thermoplastic resin is a polyacetal-based resin, and the polyacetal-based resin is a copolyacetal containing a comonomer-derived structure in an amount of 0.01 to 4 mol%.
樹脂 The resin composition according to any one of claims 23 to 31, wherein the thermoplastic resin is a crystalline thermoplastic resin having a melting point of 140 ° C or higher.
23. The resin composition according to claim 22, wherein the base resin is a thermosetting resin or a photocurable resin.
23. The resin composition according to claim 22, wherein the base resin is a rubber.
A method for producing a resin composition according to any one of claims 22 to 32,
A method comprising: kneading the composite particles according to any one of claims 1 to 12 in the form of a dry powder or an aqueous dispersion with a thermoplastic resin inside a melt kneading molding machine, and then molding. .
A thermoplastic resin,
Composite particles composed of fine cellulose and a cellulose derivative,
A method for producing a resin composition comprising:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
Including, methods.
37. The method according to claim 36, wherein the fine cellulose has a weight average molecular weight (Mw) of 100,000 or more and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 6 or less.
38. The method according to claim 36 or 37, wherein the fine cellulose has an average content of alkali-soluble polysaccharide of 12% by mass or less and a crystallinity of 60% or more.
The method comprises:
A first step of melt-kneading the thermoplastic resin in an extruder;
A second step of adding the composite particles to the molten resin of the first step;
36. The method of claim 35, comprising:
The first step is performed in a melt-kneading zone in a cylinder provided in the extruder,
The method according to any one of claims 36 to 39, wherein the second step is performed by supplying the composite particles from an addition port provided in the cylinder.
41. The method according to claim 40, wherein the addition port is disposed downstream of the melt-kneading zone.
42. The method according to claim 40 or 41, wherein the length (L2) from the outlet of the cylinder to the addition port is 1/2 or less of the total length (L1) of the cylinder.
The counterclockwise screw for kneading and dispersing the composite particles in the thermoplastic resin is provided at one or more locations in a cylinder downstream of the addition port. The method described in.
A method for producing a resin composition according to claim 33,
Mixing the composite particles with a thermosetting resin and then molding and then performing a thermosetting process; or mixing the composite particles with a photocurable resin and then molding and then performing a photocuring process,
Including, methods.
A method for producing a resin composition according to claim 34,
Mixing the composite particles with rubber, then molding and then vulcanizing.
35. The resin composition according to any one of claims 22 to 34, wherein a coefficient of variation (standard deviation / arithmetic mean value) of tensile rupture strength of the resin composition is 15% or less.
The resin composition according to any one of claims 22 to 34 and 46, wherein the tensile yield strength of the resin composition is at least 1.05 times the tensile yield strength of the thermoplastic resin.
樹脂 The resin composition according to any one of claims 22 to 34, 46, and 47, wherein the resin composition has a linear expansion coefficient in a range of 0 ° C to 60 ° C of 80 ppm / k or less.
樹脂 Resin pellets formed from the resin composition according to any one of claims 22 to 34 and 46 to 48.
樹脂 A resin molded article formed from the resin composition according to any one of claims 22 to 34 and 46 to 48.