JP6160751B1 - Method for producing cellulose acylate - Google Patents

Abstract

The value of (([M1] / 2) + [M2]) in Formula 1 calculated from the addition amount of a specific organic acid salt added in the stabilization step is less than 0.5, To provide a method for producing cellulose acylate in which coloring of a resin molded product, which is generated when a resin composition containing cellulose acylate to be obtained is heated and molded, as compared with the case of exceeding 5.0. An acylation step of acylating cellulose in the presence of sulfuric acid, a deacylation step of deacylating the acylated cellulose in the presence of hydrochloric acid, and the deacylated cellulose are identified as follows: A washing step of washing until the electric conductivity of the aqueous dispersion becomes 50 μS or less, and a stabilizing step of adding a specific organic acid salt so as to satisfy Formula 1 with respect to the deacylated cellulose after washing. A process for producing a cellulose acylate. Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0 [Selection] None

Description

  The present invention relates to a method for producing cellulose acylate.

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 Literature 1 discloses a cellulose mixed fatty acid ester in which the number of bright spot foreign matters having a size of 10 μm or more measured by the following method is 12 / mm 3 or less.
(Measurement method of bright spot foreign matter)
Cellulose mixed fatty acid ester is dissolved in a mixed solvent of methylene chloride / methanol = 9/1 (weight ratio) to obtain a 20% by weight (solid content concentration) solution (dope). This dope is cast and dried on a slide glass to obtain a film sample having a thickness of about 100 μm. This sample was observed with a polarizing microscope under a dark field, and the number of bright spot foreign matters having a maximum length of 10 μm or more in an area of 6.4 mm ² was counted and corrected with an accurate film thickness measured separately to obtain a unit volume (1 mm ³ ) Obtain the number of foreign objects per unit. The same measurement is performed on five films formed from different dopes, and the average value thereof is calculated as the number of bright spot foreign matters.

JP 2008-127535 A

  The subject of the present invention is the above formula 1 calculated from the addition amount of at least one compound selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt added in the stabilization step. The resin composition containing cellulose acylate obtained is heated and molded as compared with the case where the value of (([M1] / 2) + [M2]) is less than 0.5 or more than 5.0. It is an object of the present invention to provide a method for producing a cellulose acylate in which coloring of a resin molded product, which occurs when the resin is formed, is suppressed.

  The above problem is solved by the following means.

The invention according to claim 1 comprises an acylation step of acylating cellulose in the presence of sulfuric acid,
A deacylation step of deacylating the acylated cellulose in the presence of hydrochloric acid;
A washing step of washing the deacylated cellulose until the conductivity of the aqueous dispersion prepared by dispersing in 5 times the mass of water with respect to the total mass of the deacylated cellulose is 50 μS or less; ,
At least one compound selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt is added to the deacylated cellulose after washing so as to satisfy the following formula 1. A method for producing cellulose acylate.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: Sodium mass contained in the sodium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass M2: The calcium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass and magnesium Total amount of calcium and magnesium in organic acid salt

The invention according to claim 2 is the method for producing cellulose acylate according to claim 1, wherein the obtained cellulose acylate has an average degree of polymerization of 100 to 350 and a degree of substitution of 2.1 to 2.6. .

Invention of Claim 3 is a manufacturing method of the cellulose acylate of Claim 1 or 2 which performs the depolymerization of the said acylated cellulose in the said deacylation process.

  According to the invention of claim 1, it is calculated from the addition amount of at least one compound selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt added in the stabilization step. In addition, the resin composition containing the cellulose acylate obtained is compared with the case where the value of (([M1] / 2) + [M2]) in the above formula 1 is less than 0.5 or more than 5.0. Provided is a method for producing cellulose acylate in which coloring of a resin molded product, which is generated when heated and molded, is suppressed.

  According to the invention according to claim 2, the average degree of polymerization of the obtained cellulose acylate exceeds 350, the degree of substitution is less than 2.1, or compared with the case where the degree of substitution exceeds 2.6. There is provided a method for producing a cellulose acylate in which coloring of a resin molded product, which is generated when a resin composition containing the cellulose acylate obtained is heated and molded, is further suppressed.

  According to the invention of claim 3, the resin molded product produced when the resin composition containing the cellulose acylate obtained is molded by heating, compared to the case where the depolymerization of cellulose is performed before the acylation step. There is provided a method for producing a cellulose acylate in which coloring of is suppressed more.

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

(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, a deacylation step of deacylating the acylated cellulose in the presence of hydrochloric acid, The deacylated cellulose was dispersed until the conductivity of the aqueous dispersion prepared by dispersing the deacylated cellulose in water having a mass five times the total mass of the deacylated cellulose was 50 μS or less. The washing step for washing cellulose and the deacylated cellulose after washing were selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt so as to satisfy the following formula 1. And a stabilizing step of adding at least one compound.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: Sodium mass contained in the sodium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass M2: The calcium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass and magnesium Total amount of calcium and magnesium in organic acid salt

Here, conventionally, when acylating cellulose, sulfuric acid is generally used as a catalyst (hereinafter also referred to as “acylation catalyst”).
However, when the obtained resin composition containing cellulose acylate (acylated cellulose) is heated and molded (for example, injection molding or the like), the resulting resin molded product may be colored.
This is because if the sulfuric acid used as the catalyst remains in the resin composition, the cellulose acylate is decomposed by sulfuric acid during the heating molding.
Therefore, in order to suppress the coloring, a basic salt is added to neutralize sulfate ions.
However, the addition of the basic salt causes the coloration when calcium ions, magnesium ions, or sodium ions remain in the cellulose acylate or the resin composition.

On the other hand, according to the method for producing cellulose acylate according to the present embodiment, the cellulose acylate in which coloring of the resin molded product, which is generated when the resin composition containing the cellulose acylate to be obtained is molded by heating, is suppressed. Rate production is realized.
The reason is estimated as follows.
Compared to the conventional method using sulfuric acid in the step of deacylation, use of hydrochloric acid in the deacylation in the deacylation step, and 5 times the total mass of the deacylated cellulose Since the amount of free sulfuric acid remaining is reduced by washing the deacylated cellulose until the conductivity of the aqueous dispersion prepared by dispersing in mass water is 50 μS or less, the resulting cellulose acylate is Production of cellulose acylate in which coloring of the resin molded product, which is generated when the resin composition containing the resin composition is heated and molded, is suppressed.
Further, by neutralizing sulfuric acid in the stabilization step, the remaining esterified sulfuric acid is further reduced, and the residual amount of calcium ions, magnesium ions and sodium ions is reduced. Production of cellulose acylate in which coloring of the resin molded product, which is generated when the resin composition containing acylate is heated and molded, is realized.

  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 deacylation of the acylated cellulose in the presence of hydrochloric acid (hereinafter referred to as “first acylation step”). 1 deacylation step)) until the electric conductivity of the aqueous dispersion prepared by dispersing in water 5 times the total mass of the deacylated cellulose is 50 μS or less. A washing step for washing the deacylated cellulose (hereinafter also referred to as “first washing step”) and a calcium organic acid salt, magnesium so as to satisfy the following formula 1 for the deacylated cellulose after the washing: A stabilization step of adding at least one compound selected from the group consisting of an organic acid salt and a sodium organic acid salt (hereinafter also referred to as “first stabilization step”),
In the deacylation step, the acylated cellulose is depolymerized.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: Sodium mass contained in the sodium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass M2: The calcium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass and magnesium Total amount of calcium and magnesium in organic acid salt

According to the method for producing cellulose acylate according to the first embodiment, coloring of the resin molded product, which occurs when the resin composition containing cellulose acylate to be obtained is molded by heating, is suppressed, and the molecular weight distribution is A narrow cellulose acylate is obtained.
The detailed reason why cellulose acylate having a narrow molecular weight distribution can be obtained is unknown, but when deacylation (hydrolysis or saponification) and depolymerization are carried out in the presence of hydrochloric acid, these reactions proceed in a homogeneous manner. It is considered a thing. Thereby, the spread of the molecular weight distribution is suppressed, and it is presumed that a cellulose acylate having a narrow molecular weight distribution is obtained.

[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 be used together 2 or more types.

  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).

[First deacylation step]
In the first deacylation step, acylated cellulose (hereinafter also referred to as “primary cellulose acylate”) is deacylated and depolymerized in the presence of hydrochloric acid. 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, an aqueous hydrochloric acid solution is added to the solution that has undergone the first acylation step (a solution containing a primary cellulose acylate, an acylation catalyst, an acylating agent, and an acylating solvent). Stir after addition. That is, from the viewpoint of productivity, the first acylation step and the first deacylation step are preferably performed continuously in the same container.

-Deactivator-
In addition, in order to deactivate the remaining acylating agent before adding the hydrochloric acid aqueous solution, water or a mixed solution containing water and at least one selected from an acylating solvent (alkylcarboxylic acid) and a neutralizing agent, etc. It is better to add a quencher to the solution.
Neutralizing agents include alkali metal compounds (hydroxides such as sodium hydroxide and potassium hydroxide; carbonates such as sodium carbonate and potassium carbonate; organic acid salts such as sodium acetate and potassium acetate), alkaline earth metals Examples include bases such as compounds (hydroxides such as calcium hydroxide; carbonates such as calcium carbonate; organic acid salts such as calcium acetate).

-Hydrochloric acid-
In the first deacylation step, the amount of hydrochloric acid is 0.5% by mass or more and 5% by mass with respect to primary cellulose acylate (cellulose acylated in the first acylation step) from the viewpoint of suppressing coloring of the resin molded product. It is preferably at most 1 mass%, more preferably at least 1 mass% and at most 3 mass%.
When the acylation step and the deacylation step are carried out continuously in the same container, the mass of the primary cellulose acylate is calculated on the assumption that all of the charged cellulose is triacylate with a substitution degree of 3. To do.

-Conditions for the first deacylation step-
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).

The first deacylation step was obtained by, for example, precipitating and filtering primary cellulose acylate after the first acylation step (obtained by washing, drying, etc. as necessary), powder. Primary cellulose acylate may be used. Here, the precipitation of the primary cellulose acylate is carried out, for example, by mixing a solution containing the primary cellulose acylate and a large amount of water.
In this case, in the first deacylation step, powder is prepared in a solution containing hydrochloric acid and a deacylation solvent (the same solvent as the acylation solvent, specifically, an alkylcarboxylic acid or a mixed solvent of an alkylcarboxylic acid and water). The primary cellulose acylate is deacylated and depolymerized in a state where the primary cellulose acylate is dissolved. Note that powdery primary cellulose acylate may be dissolved in a solution containing hydrochloric acid and a solvent, or an aqueous hydrochloric acid solution may be added to a solution in which powdered primary cellulose acylate is dissolved in a solvent.

[First cleaning step]
In the first washing step, secondary cellulose acylate is used until the electric conductivity of the aqueous dispersion prepared by dispersing in 5 times the mass of water with respect to the total mass of the deacylated cellulose is 50 μS or less. Wash.
The first washing step is a step of removing sulfuric acid, acylating agent, and hydrochloric acid.
The washing method is not particularly limited, and may be washed by a known method. For example, after the first acylation step, water is used for precipitation, followed by filtration, and the filtrate is further washed with a washing solution. The method of using and washing | cleaning is mentioned.
Examples of the cleaning liquid include water, and may include alkali ions such as sodium and potassium from the viewpoint of detergency.
The electrical conductivity is measured by an AC two-electrode method by preparing an aqueous dispersion prepared by dispersing in water having a mass five times the total mass of deacylated cellulose (secondary cellulose acylate). The mass of the secondary cellulose acylate in the dispersion is calculated from the amount of cellulose used in the first acylation step and the degree of substitution.
The conductivity is preferably 50 μS or less, more preferably 30 μS or less, and even more preferably 10 μS or less.
The lower limit of the conductivity is not particularly limited and may be 0.1 μS or more.
If the electrical conductivity is 50 μS or less, the resin composition containing the cellulose acylate obtained is excellent in suppressing the coloring of the resin molded product, which occurs when the resin composition is heated and molded.

[First stabilization step]
In the first stabilization step, the deacylated cellulose after washing was selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt so as to satisfy the following formula 1. At least one compound (hereinafter also referred to as “specific organic acid salt”) is added.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: Sodium mass contained in the sodium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass M2: The calcium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass and magnesium The total amount of calcium and magnesium contained in the organic acid salt According to the first stabilization step of this embodiment, the sulfuric acid remaining after forming the deacylated cellulose and sulfate ester after washing Since it is removed from the deacylated cellulose by forming a sulfate with calcium, magnesium or sodium contained in the specific organic acid salt, the resulting resin composition containing cellulose acylate is heated and molded. Coloring of the resin molding resulting from the decomposition of cellulose acylate by sulfuric acid is suppressed. Speculate that.
On the other hand, by using hydrochloric acid in the first deacylation step and performing the first washing step, the amount of remaining sulfuric acid is reduced, so that the specific organic used in the first stabilization step is reduced. The amount of acid salt can be reduced. As a result, according to the 1st stabilization process of this embodiment, it is estimated that coloring of the resin molding derived from a calcium ion, a magnesium ion, or a sodium ion is also suppressed.

In the first stabilization step, the specific organic acid salt is added so as to satisfy the formula 1 and the specific organic acid salt is added so as to satisfy the following formula 2 with respect to the deacylated cellulose after washing. The specific organic acid salt is more preferably added so as to satisfy the following formula 3.
Formula 2: 0.7 ≦ ([M1] / 2) + [M2] ≦ 4.0
Formula 3: 0.8 ≦ ([M1] / 2) + [M2] ≦ 3.0
Resin produced when the resin composition containing cellulose acylate obtained is heated and molded by adding a specific organic acid salt so as to satisfy Formula 1 with respect to the deacylated cellulose after washing Excellent suppression of coloring of the molded product.

The amount of deacylated cellulose after washing in M1 and M2 described in Formulas 1 to 3 is calculated from the amount of cellulose used in the first acylation step and the degree of substitution. In M1 and M2, the sodium mass contained in the sodium organic acid salt, or the calcium organic acid salt and the calcium mass and magnesium mass contained in the magnesium organic acid salt are the specific organic acid salt used. And the molecular weight of the specific organic acid salt.
For example, as the specific organic acid salt, the amount of cellulose used in the first acylation step is 100 parts by mass, the degree of substitution after the first deacylation step is 2.4, and 0.285 parts by mass of calcium acetate is used. When used, ([M1] / 2) + [M2] is obtained as follows.

Amount of deacylated cellulose = 100 × 263 / 162≈162 parts by mass M1 = 0
M2 = 100/162 × 0.285 × 40 / 158≈0.044
([M1] / 2) + [M2] = 0.044

In addition, the following value was used for the said calculation.
Cellulose unit molecular weight used in the first acylation step = 162
Structural unit molecular weight of cellulose acylate having a degree of substitution of 2.4 after the first deacylation step = 263
Molecular weight of calcium acetate = 158
Atomic weight of calcium = 40

-Specific organic acid salt-
The specific organic acid salt used in this embodiment is an alkyl carboxylic acid (for example, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, etc., linear or branched and having 1 to 6 carbon atoms) Alkylcarboxylic acid) calcium salt, magnesium salt and sodium salt are preferable, and acetic acid calcium salt, magnesium salt and sodium salt are preferable.
In addition, among the calcium salts, magnesium salts, and sodium salts in the specific organic acid salt, a viewpoint of suppressing coloring of the resin molded body that occurs when the resin composition containing the cellulose acylate to be obtained is heated and molded. Therefore, calcium salt and magnesium salt are preferable, and calcium salt is more preferable.
A specific organic acid salt may be used individually by 1 type, and may use 2 or more types together.

-Conditions for the first stabilization process-
The first stabilization step is preferably performed by adding a specific organic acid salt to a dispersion in which the deacylated cellulose after washing is dispersed in a solvent.
The solvent is not particularly limited as long as it does not dissolve the deacylated cellulose after washing and dissolves the specific organic acid salt, but water is preferable.
The concentration of the deacylated cellulose after washing in the dispersion is preferably 5% by mass to 30% by mass and more preferably 7% by mass to 15% by mass with respect to the total mass of the dispersion. Is more preferable.
The specific organic acid salt may be added by dispersing the deacylated cellulose after washing in a solution containing the specific organic acid salt and a solvent (for example, an aqueous solution of the specific organic acid salt). You may carry out by adding the aqueous solution of a specific organic solvent, after disperse | distributing a cellulose to the solution to contain.
Suitable conditions for the first stabilization step are, for example, as follows.
Temperature: For example, 10 ° C to 80 ° C (preferably 15 ° C to 40 ° C)
Time: For example, 0.5 hours to 10 hours (preferably 1 hour to 5 hours).

[Other processes]
After the first stabilization step, a step of washing the deacylated cellulose after washing with water or the like is carried out and then dried to obtain a desired powdery cellulose acylate.

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”). ), A deacylation step of deacylating the acylated cellulose in the presence of hydrochloric acid (hereinafter also referred to as “second deacylation step”), and the total mass of the deacylated cellulose. On the other hand, a washing step for washing the deacylated cellulose until the electric conductivity of the aqueous dispersion prepared by dispersing in 5 times mass of water becomes 50 μS or less (hereinafter also referred to as “second washing step”). )) And the deacylated cellulose after washing so that the following formula 1 is satisfied, the organic acid salt is selected from the group consisting of calcium organic acid salt, magnesium organic acid salt and sodium organic acid salt. The have a stabilizing step of adding at least one compound (hereinafter, also referred to as "second stabilization step.") And,.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: Sodium mass contained in the sodium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass M2: The calcium organic acid salt with respect to deacylated cellulose after washing of 100 parts by mass and magnesium Total amount of calcium and magnesium in organic acid salt

[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.
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 the resin composition containing the cellulose acylate obtained is heated and shape | molded is suppressed.

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

[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)
The second deacylation step adjusts the degree of substitution of the cellulose acylated in the second acylation step (hereinafter also referred to as “primary cellulose acylate”) by deacylation (hydrolysis or saponification). This is a step of obtaining cellulose acylate having a substitution degree (hereinafter also referred to as “secondary cellulose acylate”).

  Specifically, in the second deacylation step, for example, the primary cellulose acylate is deacylated in a state where the primary cellulose acylate is dissolved in a solution containing hydrochloric acid and a deacylation solvent. Note that primary cellulose acylate may be dissolved in a solution containing hydrochloric acid and a solvent, or an aqueous hydrochloric acid solution may be added to a solution in which primary cellulose acylate is dissolved in a 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). The powdered primary cellulose acylate obtained (and obtained by carrying out washing, drying, etc., if necessary) is used.

  Examples of the deacylation solvent include the same solvent as the acylation solvent used in the second acylation step. That is, examples of the deacylation solvent include alkylcarboxylic acids or mixed solvents of alkylcarboxylic acids and water.

  In the second deacylation step, the amount of hydrochloric acid is 10% by mass or more and 200% 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 homogenization of the degree of substitution. Is preferable, and 30 mass% or more and 150 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, 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).

In the second deacylation step, for example, an aqueous hydrochloric acid solution is added to the solution that has undergone the second acylation step (a solution containing a primary cellulose acylate, an acylation catalyst, an acylating agent, and an acylating solvent). May be.
In this case, in order to deactivate the remaining acylating agent before adding the hydrochloric acid aqueous solution, water or a mixed solution containing water and at least one selected from an acylating solvent (alkylcarboxylic acid) and a neutralizing agent It is better to add a quenching agent such as
Neutralizing agents are alkali metal compounds (hydroxides such as sodium hydroxide and potassium hydroxide; carbonates such as sodium carbonate and potassium carbonate; organic acid salts such as sodium acetate and potassium acetate), alkaline earth metal compounds Bases such as (hydroxides such as calcium hydroxide; carbonates such as calcium carbonate; organic acid salts such as calcium acetate).

[Second cleaning step]
The second washing step is performed in the same manner as the first washing step using the secondary cellulose acylate obtained in the second deacylation step.

[Second stabilization step]
The second stabilization step is performed in the same manner as the first stabilization step using the secondary cellulose acylate after washing obtained in the second washing step.

[Other processes]
After the second stabilization step, a step of washing the deacylated cellulose after washing with water or the like is carried out, followed by drying to obtain a desired powdery cellulose acylate.

  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.

(Cellulose acylate)
Hereinafter, preferred characteristics of cellulose acylate produced by the method for producing cellulose acylate according to this embodiment (hereinafter also referred to as “cellulose acylate according to this embodiment”) will be described.

The cellulose acylate according to the present embodiment is a cellulose acylate (particularly, cellulose diacetate) having a degree of polymerization of 100 or more and 350 or less and a degree of substitution of 2.1 or more and 2.6 or less. preferable.
If the degree of polymerization and the degree of substitution are within the above ranges, coloring of the resin molded product, which occurs when the resin composition containing cellulose acylate is heated and molded, is suppressed.
However, the characteristics of the cellulose acylate according to the present embodiment are not limited to the above characteristics, and are selected according to the intended use of the cellulose acylate.

  The degree of polymerization of the cellulose acylate according to the present embodiment is preferably 100 or more and 350 or less, preferably 100 or more and 350 or less, from the viewpoint of reducing the melting temperature (improving moldability) and improving the strength of the resulting resin composition. 150 or more and 300 or less are more preferable.

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 degree of substitution of the cellulose acylate according to this embodiment is preferably 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, 2.1 or more and 2.5 or less are 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.

  The molecular weight distribution of the cellulose acylate according to this embodiment is preferably 1.5 or more and 5 or less, and more preferably 2 or more and 3.5 or less, from the viewpoints of improving transparency and reducing melting temperature (improving moldability). .

Here, the molecular weight distribution is a ratio (Mw / Mn) between the weight average molecular weight Mw and the number average molecular weight Mn.
And the weight average molecular weight Mw and the number average molecular weight Mn use a dimethylacetamide / lithium chloride = 90/10 solution, and a gel permeation chromatography apparatus (GPC apparatus: manufactured by Tosoh Corporation, HLC-8320GPC, column: TSKgel α-M). In polystyrene conversion.

  The cellulose acylate according to this embodiment is used as a resin for forming a resin molded body, specifically, an injection molding resin, an extrusion molding resin, or the like.

(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 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. 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, housing of electronic / electrical equipment and home appliances; various parts of electronic equipment, electrical equipment and home appliances; interior parts of automobiles; storage cases such as CD-ROM and DVD; tableware; beverage bottles; 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]
Immediately after stirring, 3 kg of acetic acid and 1.2 L of pure water were added to the resulting solution containing cellulose triacetate. After stirring at 20 ° C. for 30 minutes, 0.2 M hydrochloric acid aqueous solution 20 L (hydrochloric acid amount = 0.3 kg) was added. In addition, the mixture was heated to 75 ° C. and stirred for 5 hours. Thereby, depolymerization proceeded with deacylation of cellulose triacetate.
Next, the stirred solution was dropped into 200 L of pure water over 2 hours, allowed to stand for 20 hours, and then filtered through a filter having a pore size of 6 μm to obtain 4 kg of white powder (cellulose diacetate).

[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.

[Stabilization process]
200 g of calcium acetate and 30 L of pure water were added to 3 kg of the dried white powder, stirred at 25 ° C. for 2 hours, 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 150 g of sulfuric acid used in the acylation step was changed to 290 g.

<Synthesis of cellulose acetate CA3>
Cellulose acetate (CA3) was obtained in the same manner as cellulose acetate (CA1) except that the amount of sulfuric acid used in the acylation step was changed to 150 g.

<Synthesis of cellulose acetate CA4>
Cellulose acetate (CA4) was obtained in the same manner as cellulose acetate (CA1) except that the place of stirring for 5 hours in the deacylation step was changed to 7 hours.

<Synthesis of cellulose acetate CA5>
Cellulose acetate (CA5) was obtained in the same manner as cellulose acetate (CA1) except that the place of stirring for 5 hours in the deacylation step was changed to 4 hours 30 minutes.

<Synthesis of cellulose acetate CA6>
Cellulose acetate (CA6) was obtained in the same manner as cellulose acetate (CA1) except that the solution obtained in the acylation step was allowed to stand at room temperature for 10 hours and then deacylated.

<Synthesis of cellulose acetate CA7>
In the deacylation step, cellulose acetate (CA7) was obtained in the same manner as cellulose acetate (CA1) except that stirring at 75 ° C. for 5 hours was performed at 65 ° C. for 7 hours.

<Synthesis of cellulose acetate CA8>
In the deacylation step, cellulose acetate (CA8) was obtained in the same manner as cellulose acetate (CA1) except that stirring at 75 ° C. for 5 hours was performed at 80 ° C. for 4 hours.

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

<Synthesis of cellulose acetate CA9>
In the stabilization step, cellulose acetate (CA9) was obtained in the same manner as cellulose acetate (CA1) except that 200 g of magnesium acetate was used instead of 200 g of calcium acetate.

<Synthesis of Cellulose Acetate CA10>
In the stabilization step, cellulose acetate (CA10) was obtained in the same manner as cellulose acetate (CA1) except that 400 g of sodium acetate was used instead of 200 g of calcium acetate.

<Synthesis of cellulose acetate CA11>
In the stabilization step, cellulose acetate (CA11) was obtained in the same manner as cellulose acetate (CA1) except that 600 g of calcium acetate was used instead of 200 g of calcium acetate.

<Synthesis of cellulose acetate CA12>
In the stabilization step, cellulose acetate (CA12) was obtained in the same manner as cellulose acetate (CA1) except that 40 g of calcium acetate was used instead of 200 g of calcium acetate.

<Physical properties of cellulose acylate>
The kind of the specific organic acid salt in the stabilization step, the value of [M1] / 2 + [M2] described in the formula 1, and the physical properties (substituent, polymerization degree, substitution degree) of each cellulose acylate obtained ) Was measured or calculated 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 Industry 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.

(Evaluation of coloring after injection molding)
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), and the coloring was quantitatively evaluated. The results are shown in Table 4.

  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, the total light transmittance of the test piece is high and coloring is suppressed even when the injection molding is performed by heating, as compared with the comparative example.

Claims (4)

An acylation step of acylating cellulose in the presence of sulfuric acid;
A deacylation step of deacylating the acylated cellulose in the presence of hydrochloric acid;
A washing step of washing the deacylated cellulose until the conductivity of the aqueous dispersion prepared by dispersing in 5 times the mass of water with respect to the total mass of the deacylated cellulose is 50 μS or less; ,
The cellulose was deacylated after the washing, so as to satisfy the following formula 1, alkyl carboxylate having 1 to 6 carbon atoms calcium, alkyl carboxylate and sodium 1 to 6 carbon atoms magnesium atoms selected from the group consisting of alkyl carboxylate having 1 to 6, method for producing a cellulose acylate having a stabilizing step of adding at least one compound.
Formula 1: 0.5 ≦ ([M1] / 2) + [M2] ≦ 5.0
M1: 100 parts by (dry weight) sodium mass fraction contained in alkyl carboxylate having 1 to 6 carbon atoms of the sodium for deacylation cellulose after washing M2: After washing 100 parts by (dry weight) deacylated alkyl carboxylate having 1 to 6 carbon atoms of the calcium to the cellulose, and the total amount of calcium mass fraction and the magnesium mass content contained in the carboxylic acid salt having 1 to 6 carbon atoms magnesium The cellulose acylate production method according to claim 1, wherein the obtained cellulose acylate has a weight average polymerization degree of 100 or more and 350 or less and a substitution degree of 2.1 or more and 2.6 or less.   In the stabilization step, the deacylated cellulose after the washing satisfies the following formula 2 so that the calcium carboxylate is an alkyl carboxylate having 1 to 6 carbon atoms, and the magnesium is an alkylcarboxyl having 1 to 6 carbon atoms. The manufacturing method of the cellulose acylate of Claim 2 which is the process of adding the at least 1 sort (s) of compound chosen from the group which consists of an acid salt and a C1-C6 alkyl carboxylate of sodium.
  Formula 2: 0.7 ≦ ([M1] / 2) + [M2] ≦ 4.0 The method for producing a cellulose acylate according to any one of claims 1 to 3 , wherein in the deacylation step, depolymerization of the acylated cellulose is performed.