JP6187653B1 - Cellulose acylate, resin composition, and resin molded article - Google Patents

Abstract

The resin composition containing cellulose acylate obtained is molded at a higher temperature than when the volume average particle size D50 measured using a laser diffraction particle size distribution measuring device is less than 10 μm or more than 100 μm. Sometimes, it is to provide a cellulose acylate in which the lightness L * of the resin molding is increased. A cellulose acylate having a volume average particle diameter D50 measured using a laser diffraction particle size distribution measuring apparatus of 10 μm or more and 100 μm or less. [Selection figure] None

Description

The present invention is cellulose acylate, the resin composition, and relates to a resin molded body.

Conventionally, various thermoplastic resins have been provided and used for various applications. For example, thermoplastic resins are used in various parts of home appliances, automobiles, office equipment, electronic electrical equipment, and the like.
In recent years, plant-derived resins have been used as thermoplastic resins, and cellulose acylate is one of conventionally known plant-derived resins.

For example, Patent Document 1 discloses that “cellulose ester satisfying the following requirements 1) total sulfuric acid remaining in cellulose ester is 10 ppm or more and 160 ppm or less as an amount with respect to cellulose ester as an amount converted to sulfuric acid;
2) Calcium is not contained or even if it is contained, it is 10 ppm or less as an amount relative to the cellulose ester, and
3) Magnesium is included, and the amount of magnesium is 10 to 60 ppm as an amount with respect to the cellulose ester. Is disclosed.

  Patent Document 2 discloses “micro-crosslinked cellulose particles formed from cellulose fibers, the cellulose fibers being cross-linked by a cross-linking agent, and being atomized”.

JP 2009-161701 A Japanese Patent Laid-Open No. 9-302001

  An object of the present invention is to provide a resin composition containing cellulose acylate obtained at a higher temperature than when the volume average particle diameter D50 measured using a laser diffraction particle size distribution measuring device is less than 10 μm or more than 100 μm. It is to provide a cellulose acylate in which the lightness L * of the resin molded body is high when molded with the above method.

  The above problem is solved by the following means.

  The invention according to claim 1 is as follows.
  The volume average particle diameter D50 measured using a laser diffraction particle size distribution analyzer is 72 μm or more and 100 μm or less, the degree of polymerization is 131 or more and 350 or less, and the degree of substitution is 2.1 or more and 2.6 or less. Cellulose acylate.

  The invention according to claim 2 is as follows.
  The cellulose acylate according to claim 1, wherein the degree of polymerization is 221 or more and 335 or less.

  The invention according to claim 3 is as follows.
  The cellulose acylate according to claim 1 or 2, wherein the substitution degree is 2.2 or more and 2.5 or less.

  The invention according to claim 4 is as follows.
  The cellulose acylate according to any one of claims 1 to 3, wherein the weight average molecular weight is from 34,000 to 90,000.

  The invention according to claim 5 is as follows.
  The cellulose acylate according to any one of claims 1 to 4, comprising an acetyl group.

  The invention according to claim 6 is as follows.
  The cellulose acylate according to any one of claims 1 to 5 is included.
  Resin composition.

  The invention according to claim 7 is as follows.
  The resin composition according to claim 6, comprising an adipic acid ester-containing compound.

  The invention according to claim 8 is as follows.
  The resin molding containing the resin composition of Claim 6 or Claim 7.

  The invention according to claim 9 is as follows.
  The resin molded body according to claim 8, wherein the resin molded body is an injection molded body.

  According to the first aspect of the present invention, the cellulose acylate has a volume average particle diameter D50 measured using a laser diffraction particle size distribution measuring device of less than 10 μm or more than 100 μm. A cellulose acylate having a lightness L * when a resin composition containing it is molded at a high temperature is provided.

  According to the invention of claim 2, the cellulose acylate has a lightness L * that is higher when a resin composition containing cellulose acylate is molded at a higher temperature than when the average degree of polymerization of cellulose acylate exceeds 350. Is provided.

  According to the invention of claim 3, when the degree of substitution of cellulose acylate is less than 2.1 or more than 2.6, when the resin composition containing cellulose acylate is molded at a high temperature, A cellulose acylate in which the lightness L * of the resin molding is increased is provided.

  According to the invention of claim 4, when the cellulose acylate contains a propionyl group, when the resin composition containing the cellulose acylate is molded at a high temperature, the lightness L * of the resin molded article becomes high. Rate is provided.

  According to the invention which concerns on Claim 5 or 6, when the resin composition containing the cellulose acylate obtained is shape | molded at high temperature compared with the case where only a nonpolar solvent is used as a deacylation solvent in a deacylation process. There is provided a method for producing a cellulose acylate in which the lightness L * of the resin molding is increased.

  According to the seventh aspect of the invention, when the cellulose acylate having a volume average particle diameter D50 of less than 10 μm or more than 100 μm is applied, which is measured using a laser diffraction particle size distribution analyzer. In comparison, when a resin composition containing cellulose acylate is molded at a high temperature, a resin composition in which the lightness L * of the resin molded body is increased is provided.

  According to the invention which concerns on Claim 8, when the resin composition containing a cellulose acylate is shape | molded at high temperature compared with the case where an adipic acid ester containing compound is not included, the lightness L * of a resin molding becomes high. Things are provided.

  According to the ninth aspect of the present invention, the cellulose acylate has a volume average particle diameter D50 measured using a laser diffraction particle size distribution measuring device of less than 10 μm or more than 100 μm. Provided is a resin molded article having an increased lightness L * when the resin composition it contains is molded at a high temperature.

  According to the invention of claim 10, the cellulose acylate has a volume average particle diameter D50 measured by using a laser diffraction particle size distribution measuring device of less than 10 μm or more than 100 μm. Provided is a resin molded article having a lightness L * when the resin composition containing it is molded by injection molding.

  Embodiments that are examples of the present invention will be described below.

(Cellulose acylate)
The cellulose acylate according to this embodiment has a volume average particle diameter D50 measured using a laser diffraction particle size distribution measuring apparatus of 10 μm or more and 100 μm or less.

Here, since the cellulose acylate has a melting temperature and a decomposition temperature close to each other, the cellulose acylate may be decomposed simultaneously with heating to the melting temperature (melting point). Therefore, when a resin composition containing cellulose acylate is molded by molding (for example, injection molding or the like) that is heated to a temperature close to the melting temperature (melting point) of cellulose acylate, cellulose acylate is decomposed and obtained. The resin molding may be colored. The colored resin molded product tends to impair the transmittance in applications that require transparency. Even in applications that do not require transparency, the color difference changes due to the difference in time held at a temperature close to the melting temperature (melting point) of cellulose acylate, and the product color is difficult to stabilize. For this reason, cellulose acylate is difficult to use in molding applications (for example, injection molding, etc.) that are heated to a temperature close to the melting temperature (melting point) of cellulose acylate, and is limited to molding applications that do not require high temperatures such as casting. This is the current situation.
Thus, even when the resin composition containing cellulose acylate is molded (for example, injection molding or the like) at a high temperature (above the temperature close to the melting temperature (melting point) of cellulose acylate), the coloring of the resin molded product is suppressed. Is desired.

  On the other hand, in the cellulose acylate according to the present embodiment, the volume average particle diameter D50 measured by the laser diffraction particle size distribution measuring device is set to 10 μm or more and 100 μm or less. Thereby, coloring of the resin molded product, which occurs when the resin composition containing cellulose acylate is molded (for example, injection molding or the like) at a high temperature (above the temperature close to the melting temperature (melting point) of cellulose acylate), is suppressed, A resin molded body having a high lightness L * is obtained. The reason is presumed as follows.

Usually, sulfuric acid is used as a catalyst for the acylation of cellulose. However, it is considered that this sulfuric acid remaining in the resin composition is a cause of coloring of the resin molded product produced when molding at high temperature. By making the volume average particle diameter D50 of cellulose acylate 10 μm or more and 100 μm or less, after the synthesis of cellulose acylate, the collision efficiency with water at the time of washing is improved. For example, sulfuric acid used as a catalyst for acylation is removed. Since it is easy, the said coloring is suppressed.
In addition, by setting the volume average particle diameter D50 of the cellulose acylate to 10 μm or more and 100 μm or less, the dissolution rate is increased when the molding is performed at a high temperature such as injection molding, temperature unevenness is eliminated, and local heating is prevented. As a result, decomposition of the cellulose ester is suppressed, and the coloration is suppressed.

<Volume average particle diameter D50>
The volume average particle diameter D50 of the cellulose acylate in this embodiment is 10 μm to 100 μm, more preferably 10 μm to 80 μm, and still more preferably 10 μm to 60 μm.
If the volume average particle diameter D50 is 100 μm or less, the smaller the resin is, the smaller the resin composition containing cellulose acylate is molded at a higher temperature (above the temperature close to the melting temperature (melting point) of cellulose acylate) (for example, injection molding). Etc.), it is preferable because coloring of the resin molded product is suppressed, but from the viewpoint of suppressing secondary aggregation of cellulose acylate, it is preferably 10 μm or more.
The volume average particle diameter D50 of the cellulose acylate in this embodiment is a particle size range divided by using a particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus (for example, Nikkiso Co., Ltd., Microtrack). With respect to the channel), a cumulative distribution is drawn from the small particle diameter side with respect to the volume, and the particle diameter that becomes 50% cumulative with respect to all particles is measured as the volume average particle diameter D50.

  Hereinafter, the details of the cellulose acylate according to the present embodiment will be described.

  The cellulose acylate according to this embodiment is a cellulose derivative in which at least a part of hydroxyl groups in cellulose is substituted (acylated) with an acyl group. Specifically, for example, cellulose represented by the general formula (1) Is a derivative.

In General Formula (1), R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an acyl group. n represents an integer of 2 or more. However, at least a part of n R ¹ , n R ² , and n R ³ represents an acyl group.
The acyl group represented by R ¹ , R ² and R ³ is preferably an acyl group having 1 to 6 carbon atoms.

In general formula (1), the range of n is not particularly limited, but is preferably 40 or more and 300 or less, and more preferably 100 or more and 200 or less.
When n is 40 or more, the strength of the resin molded body is likely to increase. When n is set to 300 or less, a decrease in flexibility of the resin molded body is easily suppressed.

In the cellulose acylate according to this embodiment, a part of the hydroxyl group may be substituted with an acyl group (more preferably, an acyl group having 1 to 6 carbon atoms). That is, in the case of the cellulose derivative having the structure represented by the general formula (1), at least a part of n R ¹ , n R ² , and n R ³ represents an acyl group.
Thus, R ¹ and n times in the cellulose acylate of the general formula (1) may be different from each other in the same part in all the same. Similarly, n R ^{2 s} and n R ^{3 s} may all be the same, partially the same, or different from each other. And at least one of these represents an acyl group.

  Cellulose acylate has an acyl group having 1 to 6 carbon atoms as an acyl group, so that the elastic modulus and heat resistance are improved as compared with the case of having an acyl group having 7 or more carbon atoms.

The acyl group is represented by a structure of “—CO—R _AC ”, and R _AC represents a hydrogen atom or a hydrocarbon group (more preferably a hydrocarbon group having 1 to 5 carbon atoms).
The hydrocarbon group represented by R _AC is a linear, branched, and may be any of circular, but more preferably is linear.
The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group.
Further, the hydrocarbon group may have other atoms (for example, oxygen, nitrogen, etc.) other than carbon and hydrogen, but is more preferably a hydrocarbon group consisting of only carbon and hydrogen.
Examples of the acyl group include formyl group, acetyl group, propionyl group, butyryl group (butanoyl group), propenoyl group, hexanoyl group and the like.
Among these, as the acyl group, from the viewpoint of improving moldability of the resin composition, an acyl group having 2 to 4 carbon atoms is more preferable, an acyl group having 2 to 3 carbon atoms is more preferable, and an acyl group having 2 carbon atoms is more preferable. An acyl group (acetyl group) is particularly preferred. That is, the cellulose acylate preferably has an acetyl group.

  The degree of polymerization of the cellulose acylate according to this embodiment is preferably from 100 to 350, preferably from 120 to 330, from the viewpoint of reducing the melting temperature (improving moldability) and improving the strength of the resulting resin composition. More preferably, it is 150 or more and 320 or less.

Here, the degree of polymerization is determined from the weight average molecular weight by the following procedure.
First, the weight average molecular weight of cellulose acylate is polystyrene in a gel permeation chromatography apparatus (GPC apparatus: HLC-8320GPC, column: TSKgel α-M, manufactured by Tosoh Corporation) using a dimethylacetamide / lithium chloride = 90/10 solution. Measure in conversion.
Next, the degree of polymerization of cellulose acylate is determined by dividing by the molecular weight of the structural unit of cellulose acylate. For example, when the substituent of cellulose acylate is an acetyl group, the structural unit molecular weight is 263 when the degree of substitution is 2.4, and 287 when the degree of substitution is 2.9.

  The substitution degree of the cellulose acylate according to this embodiment is preferably a substitution degree of 2.1 or more and 2.6 or less from the viewpoint of reducing the melting temperature (improving moldability) and improving the strength of the resulting resin composition. 2 or more and 2.5 or less is more preferable, and 2.2 or more and 2.45 or less is more preferable.

Here, the degree of substitution is an index indicating the degree to which the hydroxyl group of cellulose is substituted with an acyl group. That is, the degree of substitution is an index indicating the degree of acylation of cellulose acylate. Specifically, the degree of substitution means an intramolecular average of the number of substitutions in which three hydroxyl groups in the D-glucopyranose unit of cellulose acylate are substituted with acyl groups.
Then, the degree of substitution is ^at H 1 -NMR (manufactured by JMN-ECA / JEOL RESONANCE Co.), measured from the area ratio of the cellulose-derived hydrogen and an acyl group derived peak.

(Method for producing cellulose acylate)
The method for producing cellulose acylate according to the present embodiment includes an acylation step of acylating cellulose in the presence of sulfuric acid, and deacylation of deacylating the acylated cellulose in the presence of acetic acid in a polar solvent. It is preferable that it is a manufacturing method of the cellulose acylate which has a process.
Here, in the method for producing cellulose acylate according to the present embodiment, the volume-average particle diameter D50 measured using a laser diffraction particle size distribution measuring device is 10 μm or more by performing the deacylation step in a polar solvent. A cellulose acylate having a size of 100 μm or less is obtained.
The polar solvent used in the deacylation step dissolves cellulose acylate, but the solubility varies depending on the substitution degree and molecular weight of cellulose acylate, so cellulose acylate is divided into dissolved and insoluble components during the deacylation step. By removing the insoluble matter by filtration after the deacylation step, a cellulose acylate having a particle size after reprecipitation of reprecipitation of not less than 10 μm and not more than 100 μm, and having a narrow substitution degree distribution and molecular weight distribution is obtained. Coloring of the resin molded body, which occurs when a resin composition containing acylate is molded at a high temperature, is suppressed.

(Method for producing cellulose acylate)
Hereinafter, the detail of the manufacturing method of the cellulose acylate which concerns on this embodiment is demonstrated.

<First Embodiment>
The method for producing cellulose acylate according to the first embodiment is, for example,
An acylation step for acylating cellulose in the presence of sulfuric acid (hereinafter also referred to as “first acylation step”), and a deacylation step for deacylating the acylated cellulose in the presence of acetic acid in a polar solvent (Hereinafter also referred to as “first deacylation step”),
In the deacylation step, the acylated cellulose is depolymerized.

[First acylation step]
In the first acylation step, cellulose is acylated in the presence of sulfuric acid.
Specifically, in the first acylation step, for example, cellulose is acylated while stirring in a state where cellulose is immersed or dispersed in a solution containing sulfuric acid, an acylating agent, and an acylating solvent. In addition, cellulose may be immersed or dispersed in a solution containing sulfuric acid, an acylating agent, and an acylating solvent, or sulfuric acid and an acylating agent may be added to a solution in which cellulose is immersed or dispersed in an acylating solvent. Also good.

-Cellulose-
The cellulose to be acylated is high molecular weight cellulose (for example, cellulose having a polymerization degree of 1,000 to 10,000). As the high molecular weight cellulose, for example, various raw material celluloses such as wood pulp (coniferous pulp, hardwood pulp) and cotton linter pulp are used. Commercially available cellulose may be used as the high molecular weight cellulose. Examples of commercially available high molecular weight cellulose include KC Flock W50, W100, W200, W300G, W400G, W-100F, W60MG, W-50GK, W-100GK, NDPT, NDPS, LNDP, NSPP manufactured by Nippon Paper Industries Co., Ltd. -HR etc. are mentioned.
In addition, the cellulose used as the object of acylation may also contain different components such as hemicellulose derived from the raw material (pulp). For this reason, in this specification, the term "cellulose" also means containing different components, such as hemicellulose.

  The cellulose to be acylated may be subjected to an activation treatment. The activation treatment is, for example, a method of treating cellulose using an activator containing water (a method of spraying an activator on cellulose, a method of immersing cellulose in an activator, or the like). The activator may use an acylating solvent. Specifically, as the activation treatment, 1) a method of mixing cellulose and water, filtering the cellulose, mixing cellulose and an acylating solvent, and filtering the cellulose, and 2) mixing water and cellulose Examples thereof include a method of mixing a liquid (for example, a mixed liquid having a water content of 0 to 50% by mass) and cellulose and filtering the cellulose.

Note that the temperature of the activation treatment is, for example, 0 ° C. or higher and 100 ° C. or lower (preferably 10 ° C. or higher and 40 ° C. or lower).
The time for the activation treatment (the total time when the treatment is performed twice) is, for example, 0.1 hours to 20 hours (preferably 1 hour to 15 hours).

-Acylation catalyst-
Sulfuric acid is applied as the acylation catalyst. In addition, formic acid, nitric acid, hydrochloric acid and the like may be used in combination as the acylation catalyst.

  The amount of sulfuric acid as the acylation catalyst is preferably 1% by mass or more and 20% by mass or less, and more preferably 4% by mass or more and 12% by mass or less in terms of mass ratio to cellulose from the viewpoint of suppressing coloring of the resin molded product.

-Acylating agent-
Examples of the acylating agent include compounds having an acyl group. Specifically, as the acylating agent, an alkylcarboxylic acid anhydride (for example, an alkyl having 2 to 6 carbon atoms in a straight or branched chain such as acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, etc. Suitable examples include carboxylic acid anhydrides) and organic acid halides (eg, acetic acid chloride, propionic acid chloride, butyric acid chloride, etc.). However, alkylcarboxylic acid anhydride is usually used as the acylating agent.
The acylating agent is selected according to the type of cellulose acylate desired to be obtained by acylation. For example, when cellulose acetate is obtained, acetic anhydride is applied as an acylating agent. Further, when cellulose acetate propionate is obtained, two kinds of acetic anhydride and propionic anhydride are applied as acylating agents.
In addition, an acylating agent may be used individually by 1 type, and may use 2 or more types together.

  The amount of acylating agent is selected according to the degree of substitution of cellulose acylate desired to be obtained by acylation. Usually, in the first acylation step, cellulose acylate having a substitution degree of 3 (cellulose triacylate) is often obtained. In this case, the amount of acylating agent is preferably from 1 to 5 times, more preferably from 1.5 to 4 times, as the molar ratio of cellulose to hydroxyl groups.

-Acylation solvent-
As the acylating solvent, an alkyl carboxylic acid (for example, a linear or branched alkyl carboxylic acid having 1 to 6 carbon atoms such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, and valeric acid) is preferably used. Can be mentioned.
Among these, formic acid and acetic acid are preferable as the acylating solvent, and acetic acid is particularly preferable from the viewpoint of suppressing coloring of the resin molded body.
In addition, an acylating agent may be used individually by 1 type, and may be used together 2 or more types.

  The amount of acylated solvent is preferably 3 to 20 times and more preferably 5 to 15 times in terms of mass ratio to cellulose from the viewpoint of increasing reactivity and simplifying the subsequent solvent removal step.

  As the acylating solvent, water may be used in combination with the alkylcarboxylic acid. However, the amount of water is 50% by mass or less based on the alkylcarboxylic acid.

-Conditions for the first acylation step-
Suitable conditions for the first acylation step are, for example, as follows.
Temperature: For example, 10 ° C to 80 ° C (preferably 15 ° C to 40 ° C)
Time: For example, 1 hour to 12 hours (preferably 2 hours to 8 hours).

  After the first acylation step, the acylated cellulose is precipitated and filtered by mixing a solution containing the acylated cellulose and a large amount of water, and then washed, dried, etc. as necessary to obtain acyl. Cellulose acylate is obtained.

[First deacylation step]
In the first deacylation step, the acylated cellulose (hereinafter also referred to as “primary cellulose acylate”) is deacylated and depolymerized in the presence of acetic acid in a polar solvent. In the first deacylation step, the degree of substitution of primary cellulose acylate is adjusted by deacylation (hydrolysis or saponification), and the molecular weight of primary cellulose acylate is reduced by depolymerization to achieve the desired substitution. This is a step of obtaining a cellulose acylate having a degree of polymerization and a degree of polymerization (hereinafter also referred to as “secondary cellulose acylate”).

  Specifically, in the first deacylation step, for example, a polar solvent and acetic acid are added to the primary cellulose acylate that has passed through the first acylation step, followed by stirring. In addition, powdery primary cellulose acylate may be dissolved in a solution containing a polar solvent and acetic acid, or acetic acid may be added to a solution in which powdered primary cellulose acylate is dissolved in a polar solvent.

-Polar solvent-
The polar solvent is not particularly limited as long as it dissolves the primary cellulose acylate. For example, it suppresses coloring of the resin molded product that occurs when a resin composition containing the obtained cellulose acylate is molded at a high temperature. From the viewpoint of sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, and acetamides such as N, N-dimethylacetamide and N, N-diethylacetamide Solvent, pyrrolidone solvent such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, phenol solvent such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenol, catechol, Tetrahydrofuran, dioxane, di Ether solvents such Kisoran, chloroform, chlorinated solvents such as methylene chloride or hexamethylphosphoramide, and γ- butyrolactone can be mentioned preferably, tetrahydrofuran and the like and more preferably.

  The polar solvent is preferably added so as to be 100% by mass to 500% by mass and more preferably 150% by mass to 300% by mass with respect to the total mass of the primary cellulose acylate.

-Acetic acid-
In the first deacylation step, acetic acid is used as a deacylation catalyst.
In the first deacylation step, the amount of acetic acid is preferably 30% by mass or more and 500% by mass or less, and more preferably 80% by mass or more and 150% by mass or less, as a mass ratio to the primary cellulose acylate.

Suitable conditions for the first deacylation step are selected according to the degree of substitution and the degree of polymerization of the secondary cellulose acylate to be obtained, and are as follows, for example.
Temperature: For example, 40 ° C. or higher and 100 ° C. or lower (preferably 50 ° C. or higher and 90 ° C. or lower)
Time: for example, 1 hour to 15 hours (preferably 2 hours to 12 hours).

  After the first deacylation step, by mixing a solution containing secondary cellulose acylate and a large amount of water, the acylated cellulose is precipitated and filtered, and then washed, dried, etc. as necessary. A powdery acylated cellulose acylate is obtained.

In addition, after carrying out the step of neutralizing the filtered secondary cellulose acylate, the step of washing the neutralized secondary cellulose acylate with water, etc., it is dried to obtain the desired powdery cellulose acylate. It is good to get a rate.
Here, the neutralization treatment is, for example, alkyl carboxylic acid (for example, linear or branched alkyl carboxylic acid having 1 to 6 carbon atoms such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, etc. ) Metal salt (metal salt of periodic table group 1 element such as Na, periodic table group 2 element such as Ca, etc.).

Second Embodiment
The method for producing a cellulose acylate according to the second embodiment is, for example, an acylation step for acylating cellulose having a degree of polymerization of 100 or more and 350 or less in the presence of sulfuric acid (hereinafter also referred to as “second acylation step”). And a deacylation step (hereinafter also referred to as “second deacylation step”) in which the acylated cellulose is deacylated in the presence of acetic acid in a polar solvent.

[Second acylation step]
In the method for producing a cellulose acylate according to the second embodiment, the second acylation step is the same as the first acylation step of the first embodiment, except that cellulose having a degree of polymerization of 100 to 350 is acylated as cellulose. To implement.

  In addition, after a 2nd acylation process, water is added to the solution containing a cellulose acylate, cellulose acylate is deposited, it filters, It dries, and the target cellulose acylate is obtained.

  Here, in the method for producing a cellulose acylate according to the second embodiment, if necessary, in the presence of hydrochloric acid, cellulose having a high molecular weight, cellulose having a polymerization degree of 100 or more and 350 or less before the second acylation step. You may implement the process (henceforth a "depolymerization process") etc. which obtain A.

[Depolymerization process]
The depolymerization step is a step in which high molecular weight cellulose is reduced in molecular weight by depolymerization to obtain cellulose having a target molecular weight (cellulose having a polymerization degree of 100 or more and 350 or less).
Specifically, in the depolymerization step, for example, the high molecular weight cellulose is stirred while being immersed or dispersed in a solution containing hydrochloric acid and a solvent (solvent such as water, formic acid, and acetic acid). Is depolymerized. Note that cellulose may be immersed or dispersed in a solution containing hydrochloric acid and a solvent (for example, an aqueous hydrochloric acid solution), or after immersing or dispersing cellulose in a solution containing a solvent, an aqueous hydrochloric acid solution may be added.

  The high molecular weight cellulose is, for example, cellulose having a polymerization degree of 1,000 or more and 10,000 or less, and examples thereof include the cellulose described in the first acylation step of the first embodiment.

  In the depolymerization step, the amount of hydrochloric acid is preferably 10% by mass or more and 200% by mass or less, and more preferably 30% by mass or more and 150% by mass or less in terms of mass ratio with respect to high molecular weight cellulose from the viewpoint of suppressing the spread of the molecular weight distribution.

Suitable conditions for the depolymerization step are selected according to the degree of polymerization of the cellulose to be obtained, and are as follows, for example.
Temperature: For example, 18 ° C. or higher and 100 ° C. or lower (preferably 20 ° C. or higher and 80 ° C. or lower)
Time: For example, 0.5 hours to 30 hours (preferably 1 hour to 25 hours).

  After the depolymerization step, powdered cellulose is obtained which is obtained by precipitation and filtration (washing, drying, etc., if necessary) in a solution containing cellulose having a desired degree of polymerization.

(Second deacylation step)
In the second deacylation step, the acylated cellulose (hereinafter also referred to as “primary cellulose acylate”) is deacylated and depolymerized in the presence of acetic acid in a polar solvent. In the second deacylation step, the degree of substitution of the primary cellulose acylate is adjusted by deacylation (hydrolysis or saponification), and the cellulose acylate having the desired degree of substitution and polymerization (hereinafter referred to as “secondary cellulose acylate”). It is also a process of obtaining a rate.
For this reason, also in the manufacturing method of the cellulose acylate which concerns on 2nd Embodiment, the coloring of the resin molding which arises when shape | molding the resin composition containing the cellulose acylate obtained at high temperature is suppressed.

  Specifically, in the second deacylation step, the primary cellulose acylate is deacylated with the primary cellulose acylate dissolved in a solution containing acetic acid and a polar solvent. Note that primary cellulose acylate may be dissolved in a solution containing acetic acid and a polar solvent, or acetic acid may be added to a solution in which primary cellulose acylate is dissolved in a polar solvent.

  Here, the primary cellulose acylate precipitates and filters the primary cellulose acylate from the solution that has undergone the second acylation step (a solution containing the primary cellulose acylate, the acylation catalyst, the acylating agent, and the acylating solvent). Primary cellulose acylate obtained by washing (obtained by washing, drying, etc., if necessary) is used.

-Polar solvent-
Moreover, the same solvent as the polar solvent used at a 1st deacylation process is mentioned as a polar solvent. That is, as a polar solvent, a sulfoxide solvent such as dimethyl sulfoxide and diethyl sulfoxide, which is produced when a resin composition containing cellulose acylate to be obtained is molded at a high temperature is suppressed, N , N-dimethylformamide, formamide solvents such as N, N-diethylformamide, N, N-dimethylacetamide, acetamide solvents such as N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-vinyl-2 -Pyrrolidone solvents such as pyrrolidone, phenol solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenol, catechol, ether solvents such as tetrahydrofuran, dioxane, dioxolane, chloroform, methylene chloride, etc. Chlorine based Medium, or hexamethylphosphoramide, γ- butyrolactone can be mentioned preferably, tetrahydrofuran and the like and more preferably.

  The polar solvent is preferably added so as to be 100% by mass to 500% by mass and more preferably 120% by mass to 300% by mass with respect to the total mass of the primary cellulose acylate.

-Acetic acid-
In the second deacylation step, the amount of acetic acid is 50% by mass or more and 500% by mass or less in terms of mass ratio with respect to primary cellulose acylate (cellulose acylated in the second acylation step) from the viewpoint of reactivity and particle size. Preferably, 80 mass% or more and 200 mass% or less are more preferable.

Suitable conditions for the second deacylation step are selected according to the degree of substitution of the secondary cellulose acylate to be obtained, and are as follows, for example.
Temperature: For example, 20 ° C to 100 ° C (preferably 30 ° C to 70 ° C)
Time: For example, 0.5 hours or more and 20 hours or less (preferably 2 hours or more and 8 hours or less).

  After the second deacylation step, water is added to the solution containing the secondary cellulose acylate, the secondary cellulose acylate is precipitated and filtered, and then washed and dried as necessary to obtain the desired powder form. The cellulose acylate is obtained.

  In addition, after carrying out the step of neutralizing the filtered secondary cellulose acylate, the step of washing the neutralized secondary cellulose acylate with water, etc., it is dried to obtain the desired powdery cellulose acylate. It is good to get a rate.

  In the method for producing cellulose acylate according to the present embodiment described above, depending on the type of acylating agent, various methods such as cellulose monoacetate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, etc. Cellulose acylate is obtained.

(Resin composition)
Hereinafter, a resin composition using the cellulose acylate according to this embodiment (hereinafter, also referred to as “resin composition according to this embodiment”) will be described.

The resin composition according to the present embodiment includes the cellulose acylate according to the present embodiment.
The content of the cellulose acylate according to the present embodiment is preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass with respect to the total mass of the resin composition from the viewpoint of suppressing coloring of the resin molded body. % Or more is more preferable. The upper limit of the content is not particularly limited, and may be 100% by mass or less.
The resin composition according to the present embodiment may include a plasticizer, other components, and the like as necessary.

  In addition, it is preferable that content of a plasticizer shall be the quantity from which the ratio of the cellulose acylate to the whole resin composition becomes the above-mentioned range. More specifically, the proportion of the plasticizer in the entire resin composition is preferably 15% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less. When the ratio of the plasticizer is within the above range, the hue change of the obtained resin molded body is suppressed, the elastic modulus becomes higher, and the heat resistance becomes higher. In addition, bleeding of the plasticizer (a phenomenon in which the plasticizer is precipitated) is also suppressed.

<Plasticizer>
Examples of the plasticizer include adipic acid ester-containing compounds, polyether ester compounds, sebacic acid ester compounds, glycol ester compounds, acetate esters, dibasic acid ester compounds, phosphate ester compounds, phthalate ester compounds, camphor, citric acid. Examples include esters, stearates, metal soaps, polyols, polyalkylene oxides, and the like.
Among these, adipic acid ester-containing compounds and polyether ester compounds are preferable, and adipic acid ester-containing compounds are more preferable.

[Compound containing adipic acid ester]
The adipic acid ester-containing compound (compound containing adipic acid ester) is a compound of adipic acid ester alone or a mixture of adipic acid ester and a component other than adipic acid ester (a compound different from adipic acid ester) Indicates. However, the adipic acid ester-containing compound may contain 50% by mass or more of the adipic acid ester with respect to all components.

  Examples of the adipic acid ester include adipic acid diester and adipic acid polyester. Specifically, an adipic acid diester represented by the following general formula (AE-1), an adipic acid polyester represented by the following general formula (AE-2), and the like can be given.

In General Formulas (AE-1) and (AE-2), R ^AE1 and R ^AE2 are each independently an alkyl group or a polyoxyalkyl group [— (C _x H _2X —O) _y —R ^A1 ] ( However, R ^A1 represents an alkyl group, x represents an integer of 1 to 10, and y represents an integer of 1 to 10.
R ^AE3 represents an alkylene group.
m1 represents an integer of 1 or more and 20 or less.
m2 represents an integer of 1 or more and 10 or less.

In general formulas (AE-1) and (AE-2), the alkyl group represented by R ^AE1 and R ^AE2 is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. . The alkyl group represented by R ^AE1 and R ^AE2 may be linear, branched, or cyclic, but is preferably linear or branched.
In the general formulas (AE-1) and (AE-2), in the polyoxyalkyl group [— (C _x H _2X —O) _y —R ^A1 ] represented by R ^AE1 and R ^AE2 , the alkyl group represented by R ^A1 is An alkyl group having 1 to 6 carbon atoms is preferable, and an alkyl group having 1 to 4 carbon atoms is more preferable. The alkyl group represented by R ^A1 may be linear, branched, or cyclic, but is preferably linear or branched.

In general formula (AE-2), the alkylene group represented by R ^AE3 is preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 4 carbon atoms. The alkylene group may be linear, branched or cyclic, but is preferably linear or branched.

  In general formulas (AE-1) and (AE-2), the group represented by each symbol may be substituted with a substituent. Examples of the substituent include an alkyl group, an aryl group, and a hydroxyl group.

  The molecular weight (or weight average molecular weight) of the adipic acid ester is preferably 200 or more and 5,000 or less, and more preferably 300 or more and 2,000 or less. The weight average molecular weight is a value measured according to the above-described method for measuring the weight average molecular weight of cellulose acylate.

  Hereinafter, although the specific example of an adipic acid ester containing compound is shown, it is not necessarily restricted to this.

-Polyetherester compound-
Specific examples of the polyetherester compound include a polyetherester compound represented by the general formula (EE).

In General Formula (EE), R ^EE1 and R ^EE2 each independently represent an alkylene group having 2 to 10 carbon atoms. ^AEE1 and ^AEE2 each independently represent an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. m represents an integer of 1 or more.

In general formula (EE), as an alkylene group which ^REE1 represents, a ^C3-C10 alkylene group is preferable and a C3-C6 alkylene group is more preferable. The alkylene group represented by ^REE1 may be linear, branched or cyclic, but is preferably linear.
When the number of carbon atoms of the alkylene group represented by ^REE1 is 3 or more, a decrease in fluidity of the resin composition is suppressed, and thermoplasticity is easily exhibited. When the alkylene group represented by ^REE1 has 10 or less carbon atoms or the alkylene group represented by ^REE1 is linear, the affinity with cellulose acylate is likely to increase. For this reason, when the alkylene group represented by ^REE1 is linear, and the carbon number is in the above range, the moldability of the resin composition is improved.
From these viewpoints, the alkylene group represented by ^REE1 is particularly preferably an n-hexylene group (— (CH ₂ ) ₆ —). That is, the polyether ester compound is preferably a compound representing an n-hexylene group (— (CH ₂ ) ₆ —) as R ^EE1 .

In general formula (EE), as an alkylene group which ^REE2 represents, a ^C3-C10 alkylene group is preferable and a C3-C6 alkylene group is more preferable. The alkylene group represented by ^REE2 may be linear, branched or cyclic, but is preferably linear.
When the number of carbon atoms of the alkylene group represented by ^REE2 is 3 or more, a decrease in fluidity of the resin composition is suppressed and thermoplasticity is easily exhibited. When the alkylene group represented by ^REE2 has a carbon number of 10 or less or the alkylene group represented by ^REE2 is linear, the affinity with cellulose acylate is likely to increase. For this reason, when the alkylene group represented by ^REE2 is linear and the carbon number is in the above range, the moldability of the resin composition is improved.
From these viewpoints, the alkylene group represented by ^REE2 is particularly preferably an n-butylene group (— (CH ₂ ) ₄ —). That is, the polyether ester compound is preferably a compound representing an n-butylene group (— (CH ₂ ) ₄ —) as ^REE2 .

In the general formula ^(EE), the alkyl group represented by ^{A EE1,} and ^{A EE2} is an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 2 to 4 carbon atoms. A ^EE1, and alkyl group represented by A ^EE2 are linear, branched, and may be either cyclic, branched is preferred.
Aryl groups A ^EE1, and represented by A ^EE2 is an aryl group having 6 to 12 carbon atoms, a phenyl group, an unsubstituted aryl group such as a naphthyl group, or t- butyl phenyl, substituted phenyl such as hydroxyphenyl group Groups.
A ^EE1, and aralkyl group represented by ^{A EE2,} a group represented by -R A -Ph. R ^A represents a linear or branched alkylene group having 1 to 6 carbon atoms (preferably 2 to 4 carbon atoms). Ph represents an unsubstituted phenyl group or a substituted phenyl group substituted with a linear or branched alkyl group having 1 to 6 carbon atoms (preferably 2 to 6 carbon atoms). Specific examples of the aralkyl group include unsubstituted aralkyl groups such as benzyl group, phenylmethyl group (phenethyl group), phenylpropyl group, and phenylbutyl group, or substituted groups such as methylbenzyl group, dimethylbenzyl group, and methylphenethyl group. An aralkyl group is mentioned.

At least one of A ^EE1, and ^{A EE2} is preferably an aryl group or an aralkyl group. In other words, a polyether ester ^{compound, A EE1,} and preferably (preferably a phenyl group) an aryl group as at least one of ^{A EE2} is a compound represented or aralkyl ^{group, A EE1,} and aryl groups as both ^{A EE2} ( A compound that preferably represents a phenyl group) or an aralkyl group is preferred.

  Next, the characteristics of the polyetherester compound will be described.

The weight average molecular weight (Mw) of the polyetherester compound is preferably from 450 to 650, more preferably from 500 to 600.
When the weight average molecular weight (Mw) is 450 or more, bleeding (a phenomenon of precipitation) becomes difficult. When the weight average molecular weight (Mw) is 650 or less, the affinity with cellulose acylate is likely to increase. For this reason, when a weight average molecular weight (Mw) is made into the said range, the moldability of a resin composition will improve.
In addition, the weight average molecular weight (Mw) of a polyetherester compound is a value measured by a gel permeation chromatograph (GPC). Specifically, the molecular weight measurement by GPC is carried out with a chloroform solvent using a Tosoh Corporation HPLC1100 as a measuring apparatus, using a Tosoh column TSKgel GMHHR-M + TSKgel GMHHR-M (7.8 mm ID 30 cm). . The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

The viscosity of the polyether ester compound at 25 ° C. is preferably 35 mPa · s or more and 50 mPa · s or less, and more preferably 40 mPa · s or more and 45 mPa · s or less.
When the viscosity is 35 mPa · s or more, dispersibility in cellulose acylate is easily improved. When the viscosity is 50 mPa · s or less, the anisotropy of the dispersion of the polyetherester compound hardly appears. For this reason, when a viscosity is made into the said range, the moldability of a resin composition will improve.
The viscosity is a value measured with an E-type viscometer.

The solubility parameter (SP value) of the polyether ester compound is preferably from 9.5 to 9.9, and more preferably from 9.6 to 9.8.
When the solubility parameter (SP value) is 9.5 or more and 9.9 or less, the dispersibility in cellulose acylate is easily improved.
The solubility parameter (SP value) is a value calculated by the method of Fedor. Specifically, the solubility parameter (SP value) is, for example, Polym. Eng. Sci. , Vol. 14, p. 147 (1974), the SP value is calculated by the following formula.
Formula: SP value = √ (Ev / v) = √ (ΣΔei / ΣΔvi)
(Wherein Ev: evaporation energy (cal / mol), v: molar volume (cm ³ / mol), Δei: evaporation energy of each atom or atomic group, Δvi: molar volume of each atom or atomic group)
The solubility parameter (SP value) employs (cal / cm ³ ) ^1/2 as a unit, but the unit is omitted in accordance with common practice and expressed in a dimensionless manner.

  Hereinafter, although the specific example of a polyetherester compound is shown, it is not necessarily restricted to this.

[Other ingredients]
Examples of other components include flame retardants, compatibilizers, antioxidants, mold release agents, light proofing agents, weathering agents, colorants, pigments, modifiers, anti-drip agents, antistatic agents, and hydrolysis inhibitors. , Fillers, reinforcing agents (glass fiber, carbon fiber, talc, clay, mica, glass flake, milled glass, glass beads, crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, etc.). The content of these components is preferably 0% by mass to 5% by mass with respect to the entire resin composition. Here, “0 mass%” means that other components are not included.

[Other resins]
The resin composition according to the present embodiment may contain a resin other than the cellulose acylate. However, it is preferable that other resins have an amount such that the ratio of cellulose acylate in the entire resin composition falls within the above-described range.
Examples of other resins include conventionally known thermoplastic resins, and specifically, polycarbonate resins; polypropylene resins; polyester resins; polyolefin resins; polyester carbonate resins; polyphenylene ether resins; Polyethersulfone resin; Polyarylene resin; Polyetherimide resin; Polyacetal resin; Polyvinyl acetal resin; Polyketone resin; Polyetherketone resin; Polyetheretherketone resin; Polyarylketone resin; Polyethernitrile resin; Imidazole resin; polyparabanic acid resin; selected from the group consisting of aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters, and vinyl cyanide compounds Vinyl-based polymer or copolymer resin obtained by polymerizing or copolymerizing two or more kinds of vinyl monomers; diene-aromatic alkenyl compound copolymer resin; vinyl cyanide-diene-aromatic alkenyl compound copolymer Polymer resin; aromatic alkenyl compound-diene-vinyl cyanide-N-phenylmaleimide copolymer resin; vinyl cyanide- (ethylene-diene-propylene (EPDM))-aromatic alkenyl compound copolymer resin; vinyl chloride resin Chlorinated vinyl chloride resin; and the like. These resins may be used alone or in combination of two or more.

[Method for producing resin composition]
The resin composition according to the present embodiment is produced, for example, by melt-kneading a mixture containing at least cellulose acylate and, if necessary, a plasticizer and other components. In addition, the resin composition according to the present embodiment is produced, for example, by dissolving the above components in a solvent.
Examples of the melt-kneading means include known means, and specific examples include a twin screw extruder, a Henschel mixer, a Banbury mixer, a single screw extruder, a multi-screw extruder, and a kneader.
The temperature at the time of kneading may be determined according to the melting temperature of the cellulose acylate to be used, but is preferably 140 ° C. or higher and 240 ° C. or lower, and preferably 160 ° C. or higher and 200 ° C. or higher from the viewpoint of thermal decomposition and fluidity. More preferably, it is not more than

(Resin molding)
Hereinafter, a resin molded body using the resin composition according to the present embodiment (hereinafter also referred to as “resin molded body according to the present embodiment”) will be described.

The resin molded body according to the present embodiment includes the resin composition according to the present embodiment. That is, the resin molded body according to the present embodiment is configured with the same composition as the resin composition according to the present embodiment.
Specifically, the resin molded body according to the present embodiment is obtained by molding the resin composition according to the present embodiment. As the molding method, for example, injection molding, extrusion molding, blow molding, hot press molding, calendar molding, coating molding, cast molding, dipping molding, vacuum molding, transfer molding, or the like may be applied.

The molding method of the resin molded body according to the present embodiment is preferably injection molding because it has a high degree of freedom in shape. That is, the resin molded body according to the present embodiment is preferably an injection molded body. About injection molding, a resin composition is heated and melted, poured into a mold, and solidified to obtain a molded body. You may shape | mold by injection compression molding.
The cylinder temperature for injection molding is, for example, 140 ° C. or higher and 240 ° C. or lower, preferably 150 ° C. or higher and 220 ° C. or lower, more preferably 160 ° C. or higher and 200 ° C. or lower. The mold temperature for injection molding is, for example, 30 ° C. or more and 120 ° C. or less, and more preferably 40 ° C. or more and 80 ° C. or less. The injection molding may be performed using a commercially available device such as NEX500 manufactured by Nissei Plastic Industry, NEX150 manufactured by Nissei Plastic Industry, NEX70000 manufactured by Nissei Plastic Industry, SE50D manufactured by Toshiba Machine.

  The resin molded body according to the present embodiment is suitably used for applications such as electronic equipment, electrical equipment, office equipment, home appliances, automobile interior materials, engine covers, vehicle bodies, and containers. More specifically, housings for electronic / electrical appliances and home appliances; various parts of electronic devices / electrical appliances and household electrical appliances; interior parts for automobiles; storage cases such as CD-ROMs and DVDs; tableware; Food tray; wrapping material; film; sheet;

  EXAMPLES The present invention will be described in further detail with reference to examples below, but the present invention is not limited to these examples. Note that “part” means “part by mass” unless otherwise specified.

(Synthesis of cellulose acylate)
<Synthesis of cellulose acetate (CA1)>
[Acylation step]
Cellulose powder (manufactured by Nippon Paper Chemical Co., Ltd., KC Flock W50, polymerization degree = 1020), 3 kg of concentrated sulfuric acid, 156 g of concentrated sulfuric acid (sulfuric acid amount = 150 g), 30 kg of acetic acid and 6 kg of acetic anhydride were placed in a 50 L reaction vessel and stirred at 20 ° C. for 4 hours. . This produced cellulose triacetate.

[Deacylation step]
The obtained white precipitate (cellulose triacetate) and 6 kg of acetic acid were placed in 10 L of tetrahydrofuran, heated to 50 ° C. and stirred for 8 hours. Thereby, depolymerization proceeded with deacylation of cellulose triacetate. This solution was dropped into 30 L of pure water over 2 hours to obtain a white precipitate (cellulose diacetate), which was separated by filtration.

[Washing process]
The obtained white powder (cellulose diacetate) was washed with pure water using a filter press (manufactured by Kurita Kikai Co., Ltd., SF (PP)) until the conductivity became 50 μS or less, and then dried.

-Post-treatment process-
200 g of calcium acetate and 30 L of pure water were added to 3 kg of dried white powder, stirred for 2 hours at 25 ° C., filtered, and the resulting powder was dried at 60 ° C. for 72 hours to obtain cellulose acetate (CA1). 2.5 kg was obtained.

<Synthesis of cellulose acetate (CA2)>
Cellulose acetate (CA2) was obtained in the same manner as cellulose acetate (CA1) except that the dropping time of the reaction solution to pure water in the deacylation step was 2 minutes.

<Synthesis of cellulose acetate (CA3)>
Cellulose acetate (CA3) was obtained in the same manner as cellulose acetate (CA1) except that the dropping time of the reaction solution in pure water in the deacylation step was set to 3 hours.

<Synthesis of cellulose acetate (CA4)>
Cellulose acetate (CA4) was obtained in the same manner as cellulose acetate (CA1) except that the reaction time at 50 ° C. in the deacylation step was set to 3 hours.

<Synthesis of cellulose acetate (CA5)>
Cellulose acetate (CA5) was obtained in the same manner as cellulose acetate (CA1) except that the reaction time at 50 ° C. in the deacylation step was changed to 4 hours.

<Synthesis of cellulose acetate (CA6)>
Cellulose acetate (CA6) was obtained in the same manner as cellulose acetate (CA1) except that the reaction time at 50 ° C. in the deacylation step was 10 hours.

<Synthesis of cellulose acetate (CA7)>
Cellulose acetate (CA7) was obtained in the same manner as cellulose acetate (CA1) except that the reaction time at 50 ° C. in the deacylation step was 8 hours.

<Synthesis of cellulose acetate (CA8)>
Cellulose acetate (CA8) was obtained in the same manner as cellulose acetate (CA1) except that the reaction temperature of 50 ° C. in the deacylation step was changed to 30 ° C.

<Synthesis of cellulose acetate (CA9)>
Cellulose acetate (CA9) was obtained in the same manner as cellulose acetate (CA1) except that the reaction temperature in the deacylation step was set to 40 ° C.

<Synthesis of cellulose acetate (CA10)>
Cellulose acetate (CA10) was obtained in the same manner as cellulose acetate (CA1) except that the reaction temperature of 50 ° C. in the deacylation step was changed to 55 ° C.

<Synthesis of cellulose acetate (CA11)>
Cellulose acetate (CA11) was obtained in the same manner as cellulose acetate (CA1) except that the reaction temperature of 50 ° C. in the deacylation step was changed to 60 ° C.

<Synthesis of cellulose propionate (CP1)>
In the acylation step, cellulose propionate (CP1) was obtained in the same manner as cellulose acetate (CA1) except that 6 kg of acetic anhydride was used and changed to 12.5 kg of propionic anhydride.

<Synthesis of cellulose acetate (CA12)>
Cellulose acetate (CA12) was obtained in the same manner as cellulose acetate (CA1) except that the dropping time of the reaction solution to pure water in the deacylation step was set to 15 minutes.

<Synthesis of cellulose acetate (CA13)>
Cellulose acetate (CA13) was obtained in the same manner as cellulose acetate (CA1) except that the dropping time of the reaction solution into pure water in the deacylation step was changed from 2 hours to 3 hours and 30 minutes.
<Synthesis of Cellulose Acetate (CA13-1)>
(CA13-1) was obtained in the same manner as (CA1) except that 9 kg of dimethyl sulfoxide was used in place of 10 L of tetrahydrofuran in the deacylation step.
<Synthesis of cellulose acetate (CA13-2)>
(CA13-2) was obtained in the same manner as (CA1) except that 10 L of tetrahydrofuran was used instead of 10 L of tetrahydrofuran in the deacylation step.

<Preparation of cellulose acetate (CA14 to CA16)>
The following commercially available cellulose acetates were prepared as CA14 to CA16.
CA14: Daicel Corporation, L50
CA15: manufactured by Eastman Chemical Co., CA398-3
CA16: manufactured by Daicel Corporation, LT-55

<Synthesis of Cellulose Acetate (CA17-18)>
Cellulose acetates (CA17) to (CA18) were synthesized by the synthesis methods described in Example 1 and Example 7 of JP-A-2009-161701, respectively.

<Physical properties of cellulose acylate>
The physical properties (degree of polymerization, degree of substitution, volume average particle size) of each cellulose acylate obtained were measured according to the method described above. The results are shown in Table 3.

<Preparation of adipic acid ester-containing compound>
A commercially available adipic acid ester-containing compound (Daifatty 101, manufactured by Daihachi Chemical Co., Ltd.) was prepared as Compound AE1.

(Examples and comparative examples)
The cylinder temperature was adjusted at the charged composition ratio shown in Table 4, and kneading was carried out with a biaxial kneader (TEX41SS, manufactured by Toshiba Machine Co., Ltd.) to obtain a resin composition (pellet).
About the obtained pellet, D1 and D2 test piece (measurement part dimension: width 60x60mm / thickness) using an injection molding machine (Nex140III made by Nissei Plastic Industry Co., Ltd.) and a cylinder temperature at which an injection peak pressure does not exceed 180 MPa. A 1 mm D1 test piece and a D2 test piece having a width of 60 × 60 mm and a thickness of 2 mm were formed. The cylinder temperature is shown in Table 4.
In addition, about the Example or comparative example using the resin composition which does not contain an adipic acid ester containing compound, it described as "-" in the column of the adipic acid ester containing compound in Table 4.

<Coloring evaluation after injection molding>
The total light transmittance was measured and the hue was evaluated by the following method to obtain a coloring evaluation. The evaluation results are shown in Table 4.
The total light transmittance of the obtained D1 and D2 test pieces was measured with a spectroscopic haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., SH7000).
Further, the hue of the obtained D2 test piece was measured with a color difference meter (CR410, manufactured by Konica Minolta) with the lightness L * value as a representative value.

  The details of the examples and comparative examples are listed in Tables 3 and 4 below.

  From the above results, it can be seen that in this example, even when high temperature injection molding is performed, the total light transmittance of the test piece is high and coloring is suppressed.

Claims (9)

  The volume average particle diameter D50 measured using a laser diffraction particle size distribution analyzer is 72 μm or more and 100 μm or less, the degree of polymerization is 131 or more and 350 or less, and the degree of substitution is 2.1 or more and 2.6 or less. Cellulose acylate.   The cellulose acylate according to claim 1, wherein the degree of polymerization is 221 or more and 335 or less.   The cellulose acylate according to claim 1 or 2, wherein the substitution degree is 2.2 or more and 2.5 or less.   The cellulose acylate according to any one of claims 1 to 3, wherein the weight average molecular weight is from 34,000 to 90,000.   The cellulose acylate according to any one of claims 1 to 4, comprising an acetyl group. The resin composition containing the cellulose acylate of any one of Claims 1-5. The resin composition according to claim 6 , comprising an adipic acid ester-containing compound. The resin molding containing the resin composition of Claim 6 or Claim 7 . The resin molded body according to claim 8 , wherein the resin molded body is an injection molded body.