JP2011195787A - Method for producing thermoplastic cellulose composition, and method for producing molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a cellulose composition having satisfactory thermoplastic properties and strength by a simple method.SOLUTION: The method for producing the thermoplastic cellulose composition includes an acylation step of acylating the mixture of a flocculent cellulose and a granular alkyl cellulose by an acid anhydride. The alkyl cellulose is preferably one having 1-4C alkyl group and is preferably at least one selected from the group consisting especially of hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxypropylmethyl cellulose, hydroxyethylmethyl cellulose, hydroxypropylethyl cellulose and hydroxyethylethyl cellulose. The mixing ratio of the flocculent cellulose and the granular cellulose of the mixture (the flocculent cellulose/the granular cellulose) is preferably 100/50 to 100/10 on the basis of mass.

Description

  The present invention relates to a method for producing a novel thermoplastic cellulose composition.

  Cellulose derivatives such as cellulose and cellulose esters and cellulose ethers are attracting much attention as biomass materials that can be reproduced on the earth and biodegradable materials in the environment.

  Currently, industrially produced cellulose derivatives such as cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate are highly versatile, low-cost, and the reaction proceeds under mild conditions. Thus, a method of acylating using acetic anhydride or acid anhydrides of various organic acids as an acylating agent in an organic acid solvent under a sulfuric acid catalyst is employed.

  These cellulose esters are tough and have characteristics such as high gloss, transparency, oil resistance, and light resistance, and thus are used in a wide range of fields such as fibers, plastics, filters, and paints. However, there are many cellulose esters that are colored or decomposed simultaneously with melting when heated alone. For example, the most commonly used cellulose acetate cannot obtain a good molded product without adding a plasticizer. In addition, when a cellulose derivative is melted and molded using various solvents instead of melt molding, it cannot have good flexibility without the addition of a plasticizer. It is necessary to add a plasticizer to the cellulose ester.

  For this reason, various plasticizers are used. Representative examples thereof include phthalates such as diethyl phthalate, polyhydric alcohol esters such as triacetin, phosphate esters such as triphenyl phosphate, and dibutyl adipate. Basic fatty acid esters and the like have been used.

  Regarding the mixing of the cellulose ester and the plasticizer, Patent Document 1 describes an example of kneading a separately prepared cellulose ester flake using a mixing stirrer.

  As a method using a high molecular weight plasticizer, for example, Patent Document 2 shows that phthalic acid-based polyester can be used and Patent Document 3 shows that polycaprolactone can be used. In Patent Document 4, a vinyl polymer or vinyl copolymer having an amide bond in the side chain is used as a plasticizer that is very compatible with cellulose ester. As the description regarding kneading of the cellulose derivative and the copolymer in the publication, a method of melt kneading using an extruder, kneader, Banbury mixer, roll or the like, or dissolving and kneading using an appropriate solvent is shown. Yes. Patent Document 5 describes a method of obtaining a thermoplastic composition by adding a plasticizer during cellulose ester synthesis.

JP 54-157159 A JP 61-276836 A Japanese Patent Laid-Open No. 07-076662 JP-A-12-212224 Japanese Patent No. 3932997

However, in any of Patent Documents 1 to 4, in order to obtain a cellulose ester composition containing a plasticizer, flakes of a cellulose ester derivative obtained by an arbitrary method and a plasticizer are separately melt-kneaded or melt-kneaded. Need to do.
Since the kneading temperature for melt kneading requires a high temperature of around 200 ° C., it cannot be used for kneading with a low boiling point compound. In addition, kneading of a highly viscous cellulose ester and a plasticizer requires a long time until they are uniformly mixed.
On the other hand, in dissolution kneading, it is necessary to use a solvent that dissolves both the cellulose ester and the plasticizer. Various organic solvents have been proposed as solvents for cellulose triacetate, and methylene chloride and the like can be mentioned as solvents that are substantially used. However, in recent years, the use of halogenated hydrocarbons such as methylene chloride is being regulated from the viewpoint of protecting the global environment. Moreover, since the boiling point of methylene chloride is as low as 41 ° C. and easily volatilizes in the manufacturing process, there is a problem when considering the working environment. In addition, mixed fatty acid esters of cellulose typified by cellulose acetate propionate have higher solubility than cellulose acetate, and various solvents can be used. However, even in that case, the cost of making the solvent itself and the solvent recovery step is not economical.
Further, in the method of Patent Document 5, since the plasticizer used is a general low molecular weight plasticizer, there is a problem such as evaporation of the plasticizer in drying and molding operations.

  As described above, when a plasticizer is used in order to obtain a cellulose composition having thermoplasticity, there are various problems, and further improvement has been demanded.

  This invention is made | formed in view of the above, and makes it a subject to manufacture the cellulose composition which has favorable thermoplasticity and intensity | strength by a simple method especially.

  Specific means for solving the above problems are as follows.

Item 1. A method for producing a thermoplastic cellulose composition, comprising an acylation step of acylating a mixture of cotton-like cellulose and granular alkyl cellulose with an acid anhydride.
Item 2. Item 2. The production method according to Item 1, wherein the alkyl cellulose has an alkyl group having 1 to 4 carbon atoms.
Item 3. Item 3. The production method according to Item 1 or 2, wherein the acid anhydride contains at least one selected from the group consisting of acetic anhydride, propionic anhydride, and butyric anhydride.
Item 4. Item 4. The production method according to any one of Items 1 to 3, wherein sulfuric acid or methanesulfonic acid is used as a catalyst in the acylation.
Item 5. Item 5. The item according to any one of Items 1 to 4, wherein the alkylcellulose includes at least one selected from the group consisting of hydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylethylcellulose, and hydroxyethylethylcellulose. Production method.
Item 6. Item 1-5, wherein the mixture ratio of cotton-like cellulose and granular alkylcellulose (cotton-like cellulose / granular alkylcellulose) in the mixture is 100/50 to 100/10 on a mass basis. The manufacturing method as described.
Item 7. Prior to the acylation step according to any one of Items 1 to 6,
Item 7. The production method according to any one of Items 1 to 6, comprising a pretreatment step of adding an acidic compound to the mixture.
Item 8. Item 8. A method for producing a molded body, comprising a step of melt-molding a molding material containing the thermoplastic cellulose composition obtained by the production method according to any one of Items 1 to 7.

  According to the present invention, a cellulose composition having good thermoplasticity and strength can be produced by a simple method.

  In the present invention, the use of a plasticizer is reduced by acylating a mixture of cotton-like cellulose and granular alkylcellulose with an acid anhydride, or kneading by heating is performed without using a plasticizer. A cellulose composition having good thermoplasticity and strength was successfully produced by a simple method that was not present.

  The present invention is a method for producing a thermoplastic cellulose composition, comprising an acylation step of acylating a mixture of cotton-like cellulose and granular alkyl cellulose with an acid anhydride. Below, the manufacturing method of the thermoplastic cellulose composition of this invention and the manufacturing method of a molded object using the same are demonstrated in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

(Cotton-like cellulose)
The cellulose used in the present invention is not limited as long as it is cottony. The cotton form in the present invention refers to an assembly of fibrous ones irregularly, for example, one having a bulk density of 0.1 g / 100 ml or more and 20 g / 100 ml or less. The bulk density of the cotton-like cellulose is preferably from 0.1 g / 100 ml to 15 g / 100 ml, more preferably from 1.0 g / 100 ml to 10 g / 100 ml.

  The cotton-like cellulose used in the present invention can be obtained, for example, by cutting roll-like cellulose with a shredder or the like and crushing it with a centrifugal pulverizer or the like.

  Cellulose has various shapes such as granular (bulk density of 25 g / 100 ml to 80 g / 100 ml) and cotton (bulk density of 0.1 g / 100 ml to 20 g / 100 ml). Cellulose is used.

The bulk density can be measured by the method described in JP-T-2008-534735. Specifically, the bulk density of cellulose can be measured as follows using a Lobe Pharma Electrolab Tap Density Tester (USP) model ETD-1020.
1) Measure the (empty) tare weight of a 100 ml USP1 graduated cylinder within a range of ± 0.01 g.
2) Place ~ 90 ml of uncompressed cellulose in a 100 ml USP1 graduated cylinder.
3) Place this graduated cylinder in a tap density tester and drop (tap) 200 times at a speed of 300 drops / min.
4) The obtained cellulose volume after tapping is visually measured within a range of ± 1 ml, and the weight of the cellulose is further measured within a range of ± 0.01 g.
5) Calculate the bulk density by dividing the weight of cellulose by the volume of cellulose after tapping.

The cellulose referred to in the present invention is a compound having a repeating unit represented by — (C ₆ H ₁₀ O ₅ ) —, and is a polymer compound in which a large number of glucoses are bonded by β-1,4-glycosidic bonds. It means that the hydroxyl groups bonded to the carbon atoms at the 2nd, 3rd and 6th positions in the glucose ring of cellulose are unsubstituted.

(Granular alkyl cellulose)
The alkyl cellulose used in the present invention is not limited as long as it is granular. The granular form in the present invention means that the ratio of the maximum diameter to the minimum diameter of the particles is 10 or less, for example, the bulk density is 25 g / 100 ml or more and 80 g / 100 ml or less. The bulk density of the granular alkyl cellulose is preferably 25 g / 100 ml or more and 70 g / 100 ml or less, more preferably 30 g / 100 ml or more and 60 g / 100 ml or less, and more preferably 30 g / 100 ml or more and 50 g / 100 ml or less. Most preferred. The bulk density of the granular alkyl cellulose can be measured by the same method as the measurement of the bulk density of the cotton-like cellulose.

The alkyl cellulose of the present invention preferably has an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms may be linear, branched or cyclic, and may have an unsaturated bond. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group. The alkyl group having 1 to 4 carbon atoms may have a further substituent. Additional substituents include, for example, hydroxyl groups, mercapto groups, halogen atoms (eg fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, sulfo groups, carboxyl groups, nitro groups, hydroxamic acid groups, sulfino groups, hydrazino groups. Group, imino group and the like. The further substituent that the alkyl group having 1 to 4 carbon atoms has is preferably a hydroxyl group.
When the alkyl group having 1 to 4 carbon atoms has a further substituent and the substituent includes carbon, the carbon number of the substituent is not included as the carbon number of the alkyl group having 1 to 4 carbon atoms. Shall.

  The alkyl cellulose referred to in the present invention preferably has a repeating unit represented by the following general formula (1).

(In the general formula (1), R ² , R ³ and R ⁶ each independently represent a hydrogen atom, —C _n H _{2n + 1} or — (C _m H _2m O) _k —H, where n and m are each independent. Represents an integer of 1 to 7. k represents an integer of 1 to 10, and may be different for each repeating unit, provided that at least one of R ² , R ^3, and R ⁶ is —C _n H _{2n + 1} or - a _{(C m H 2m O) k} -H).

In the general formula ^(1), at least one of R 2, ^{R 3} and ^{R 6} _- is preferably a _{(C m H 2m O) k} -H.

In the general formula (1), the group represented by —C _n H _{2n + 1} may be linear or branched. n represents an integer of 1 to 7, preferably 1 to 4, and more preferably 1 to 3. Specific examples of the group represented by —C _n H _{2n + 1} include —CH ₃ , —C ₂ H ₅ , —C ₃ H ₇ , —CH (CH ₃ ) ₂ , —C ₄ H ₉ , —CH ₂ —. CH (CH ₃ ) ₂ , —CH (CH ₃ ) —CH ₂ —CH ₃ , —C (CH ₃ ) _{3 and the} like. Preferably _{-CH 3,} -C ₂ H 5, a _-C 3 _{H 7.}

In the general formula _{(1) - (C m H} 2m O) a group represented by k -H may be either linear or branched. m represents an integer of 1 to 7, preferably 1 to 4, and more preferably 2 to 3. k represents an integer of 1 to 10, preferably 1 to 8, and more preferably 1 to 5. k may be different for each repeating unit. - _{(C m} H 2m _O) a group represented by k -H is specifically _{- (C 2 H 4 O)} k -H, - (C 3 H 6 O) k -H, - {CH 2 _{CH (CH 3) O} k} -H , and the like. Preferably _{- (C 2 H 4 O)} k -H, - a _{{CH 2 CH (CH 3)} O} k -H. Here, k is the same as defined in the general formula (1).

The compound represented by the general formula (1) is preferably hydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylethylcellulose, hydroxyethylethylcellulose, hydroxyethylmethylethylcellulose, hydroxypropylmethylethylcellulose, methylcellulose. , Ethyl cellulose, methyl ethyl cellulose and the like.
Among these, hydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylethylcellulose, hydroxyethylethylcellulose, hydroxyethylmethylethylcellulose, hydroxypropylmethylethylcellulose are preferred, hydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, Most preferred are hydroxyethylmethylcellulose, hydroxypropylethylcellulose, and hydroxyethylethylcellulose.

  The mixing ratio (cotton-like cellulose / granular alkylcellulose) in the mixture of flocculent cellulose and granular alkylcellulose in the present invention is preferably 100/100 to 100/1, and 100/50 to 100/10 on a mass basis. Is more preferable, and 100/40 to 100/20 is most preferable.

In the present invention, by using cotton-like cellulose and granular alkyl cellulose, a cellulose composition having good thermoplasticity and strength was successfully produced by a simple method. When the reaction is performed by mixing different bulk densities, the reaction is expected to be heterogeneous, so generally the bulk density is close, that is, the similar shapes are mixed. Perform the reaction. Therefore, it is usually not possible to carry out the reaction by mixing a flocculent compound and a granular compound. However, in the present invention, cotton cellulose having different shapes and granular alkyl cellulose are mixed, and the mixture is acylated with an acid anhydride, thereby reducing the use of a plasticizer or without using a plasticizer. It succeeded in producing a cellulose composition having good thermoplasticity and strength by a simple method.
The mechanism that has made it possible to produce a cellulose composition having good thermoplasticity and strength by reducing the use of a plasticizer or without using a plasticizer by using the constitution of the present invention is not clear. Although it is not, it is guessed as follows. By acylating a mixture of cotton-like cellulose and granular alkylcellulose, acylated alkylcellulose, which is thought to improve thermoplasticity, could be introduced into the composition without performing melt kneading. It is considered that thermoplasticity could be imparted to the composition.

(Acid anhydride)
The acid anhydride used in the present invention is not limited as long as it is a compound formed by elimination of one molecule of water from two molecules of carboxylic acid. The acid anhydride preferably has 4 or more carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 4 to 8 carbon atoms.

  As the acid anhydride, for example, a carboxylic acid anhydride which is a compound formed by elimination of one molecule of water from two molecules of carboxylic acid having 2 to 12 carbon atoms is used. Examples of such carboxylic anhydrides include acetic anhydride (ethanoic anhydride), propionic anhydride (propanoic anhydride), butyric anhydride (butanoic anhydride), valeric anhydride (pentanoic anhydride). , Caproic anhydride (hexanoic anhydride), enanthic anhydride (heptanoic anhydride), caprylic anhydride (octanoic anhydride), pelargonic anhydride (nonanoic anhydride), capric anhydride ( Decanoic anhydride), lauric anhydride (dodecanoic anhydride) and the like. Among these, it is preferable to contain at least one selected from the group consisting of acetic anhydride, propionic anhydride and butyric anhydride.

  In the acylation step in the present invention, it is preferable to use an acid anhydride of equimolar or more with respect to the hydroxyl group contained in the cotton-like cellulose and the granular alkylcellulose.

(Acylation step)
In the acylation step of the present invention, a mixture of cotton-like cellulose and granular alkyl cellulose is mixed with an acid anhydride. In the acylation step, an acyl group is introduced into the cellulose and the alkylcellulose by causing the hydroxyl group in the cellulose and the alkylcellulose to undergo an acylation reaction with the acid anhydride. The hydroxyl group contained in the cotton-like cellulose and granular alkyl cellulose used in the present invention is preferably 70-100 mol% acylated and 80-100 mol% acylated by the acylation step of the present invention. Further preferred. Here, the acylation degree can be determined by ¹ H-NMR using the method described in Cellulose Communication 6, 73-79 (1999).

  The reaction temperature in the acylation step of the present invention is preferably −20 to 80 ° C., and more preferably −10 to 70 ° C. from the viewpoint of the viscosity of the cellulose mixture and the reaction rate.

  The reaction time in the acylation step of the present invention is preferably 0.5 to 12 hours, and more preferably 1 to 6 hours in order to suppress the generation of by-products.

  The acylation step of the present invention is preferably performed, for example, under a pressure of 0.013 atm (10 Torr) to normal pressure, and more preferably performed under a pressure of 0.039 atm (30 Torr) to normal pressure.

  As the solvent in the acylation step of the present invention, acetic acid, propionic acid and the like are preferable, and acetic acid is more preferable. As acetic acid, glacial acetic acid is preferably used.

  Moreover, you may use an acid as a catalyst in the acylation of this invention. Preferable acids include sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, perchloric acid, phosphoric acid, trifluoroacetic acid, trichloroacetic acid and the like. More preferred are sulfuric acid and methanesulfonic acid. Most preferred is sulfuric acid. Bisulfates may also be used, and examples include lithium bisulfate, sodium bisulfate, and potassium bisulfate. A solid acid catalyst may also be used. For example, a polymer solid acid catalyst such as an ion exchange resin, an inorganic oxide solid acid catalyst typified by zeolite, and a carbon type used in JP2009-67730A. A solid acid catalyst is mentioned. A Lewis acid catalyst may also be used, and examples thereof include titanic acid ester catalysts and zinc chloride used in US Pat. No. 2,976,277.

(Pretreatment process)
The production of the thermoplastic cellulose composition in the present invention preferably includes a pretreatment step of adding an acidic compound to a mixture of cellulose and alkylcellulose prior to the acylation step. It is inferred that the pretreatment step makes the cellulose mixture suitable for the acylation step. In addition, although an acylation process is performed after a pre-processing process, you may insert another process suitably after a pre-processing process. The other step may be, for example, a cooling step or a reaction that introduces another substituent.

  The acidic compound used in the pretreatment step is not limited as long as it improves the reactivity of cellulose. Examples of the acidic compound used in the pretreatment step include acetic acid and propionic acid, and it is preferable to use acetic acid. As acetic acid, glacial acetic acid is preferably used.

  The pretreatment step is preferably performed at 10 ° C. to 80 ° C., for example, and more preferably 20 ° C. to 60 ° C.

  The pretreatment step is preferably performed, for example, over 10 minutes to 20 hours, and more preferably performed over 10 minutes to 2 hours.

  The pretreatment step is preferably performed, for example, under normal pressure to 2 atm (1520 Torr), more preferably normal pressure.

(Cellulose composition)
The cellulose composition obtained by the production method of the present invention contains acylated cellulose and acylated alkyl cellulose. The ratio of acylated cellulose to acylated alkyl cellulose (acylated cellulose / acylated alkyl cellulose) present in the cellulose composition obtained by the production method of the present invention is 100 on a mass basis. / 100 to 100/1 is preferable, 100/50 to 100/10 is more preferable, and 100/40 to 100/20 is most preferable.

  Examples of the acylated cellulose include acetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, acetyl butyryl cellulose, propionyl butyryl cellulose, and acetylpropyl butyryl cellulose. Examples of the acylated alkylcellulose include acetoxypropylacetylcellulose, acetoxypropylpropionylcellulose, propionyloxypropylacetylcellulose, propionyloxypropylpropionylcellulose, acetoxyethylacetylcellulose, acetoxyethylpropionylcellulose, acetoxypropylmethylacetylcellulose, propionyloxy Ethylacetylcellulose, propionyloxyethylpropionylcellulose, acetoxypropylethylacetylcellulose, acetoxypropylpropylacetylcellulose, acetoxypropylbutylacetylcellulose, propionyloxypropylmethylacetylcellulose, propionyloxypropylethylacetyl cell , Propionyloxypropylpropylacetylcellulose, propionyloxypropylbutylacetylcellulose, acetoxypropylpropionyloxypropylmethylacetylpropionylcellulose, butyryloxypropylmethylacetylcellulose, acetoxypropylbutyryloxypropylmethylacetylbutyrylcellulose, acetoxyethylmethyl Acetylcellulose, acetoxyethylethylacetylcellulose, acetoxyethylpropylacetylcellulose, acetoxyethylbutylacetylcellulose, acetoxyethylmethylpropionylcellulose, acetoxyethylethylpropionylcellulose, acetoxyethylpropylpropionylcellulose, acetoxyethylbutylpropionylcell Acetoxypropylmethylpropionylcellulose, acetoxyethylhexylpropionylcellulose, propionyloxyethylmethylacetylcellulose, propionyloxyethylethylacetylcellulose, propionyloxyethylpropylacetylcellulose, propionyloxyethylbutylacetylcellulose, propionyloxyethylmethylpropionylcellulose, propionyl Examples thereof include oxypropylmethyl propionyl cellulose, propionyloxyethyl ethyl propionyl cellulose, propionyloxyethyl propyl propionyl cellulose, and propionyloxyethyl butyl propionyl cellulose.

As for the molecular weight of the cellulose composition obtained by the production method of the present invention, the number average molecular weight (Mn) is preferably in the range of 5 × 10 ^{3 to} 1000 × 10 ³ , and more preferably in the range of 10 × 10 ^{3 to} 500 × 10 ^3. The range of 10 × 10 ³ to 200 × 10 ³ is most preferable. The weight average molecular weight (Mw) is preferably in the range of 7 × 10 ^{3 to} 10000 × 10 ³ , more preferably in the range of 15 × 10 ^{3 to} 5000 × 10 ³ , and in the range of 100 × 10 ^{3 to} 3000 × 10 ³ . Is most preferred. By setting the average molecular weight within this range, it is possible to improve the moldability and mechanical strength of the molded body. The molecular weight distribution (MWD) is preferably in the range of 1.1 to 10.0, and more preferably in the range of 1.5 to 8.0. By setting the molecular weight distribution within this range, moldability and the like can be improved.

  In the present invention, the number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (MWD) can be measured using gel permeation chromatography (GPC). Specifically, N-methylpyrrolidone can be used as a solvent, a polystyrene gel can be used, and the molecular weight can be obtained using a conversion molecular weight calibration curve obtained in advance from a constituent curve of standard monodisperse polystyrene.

(Method for producing molded body)
The present inventors have found a method for producing a molded body comprising a step of melt-molding a molding material containing the thermoplastic cellulose composition obtained by the production method described above by heating. This will be described in detail below.

  The method for producing a molded body in the present invention includes a step of melt-molding the molding material containing the thermoplastic cellulose composition described above by heating, and if necessary, the molding material contains other additives. be able to. The content ratio of the thermoplastic cellulose composition in the molding material is preferably 75% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less.

  In addition to the thermoplastic cellulose composition of the present invention, the molding material of the present invention may contain various additives such as fillers and flame retardants as necessary.

  The molding material of the present invention may contain a filler (reinforcing material). By containing the filler, the mechanical properties of the molded body formed of the molding material can be enhanced.

  A well-known thing can be used as a filler. The shape of the filler may be any of fibrous, plate-like, granular, powdery and the like. Further, it may be inorganic or organic. Specifically, as the inorganic filler, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, silicon whisker, wollastonite, sepiolite, slag fiber, zonolite, Elastadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber and boron fiber, and other inorganic fillers; glass flakes, non-swellable mica, carbon black, graphite, metal foil , Ceramic beads, talc, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, fine silicate, feldspar, potassium titanate, shirasu balloon, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide Beam, aluminum oxide, titanium oxide, magnesium oxide, aluminum silicate, silicon oxide, aluminum hydroxide, magnesium hydroxide, gypsum, novaculite, dawsonite, and a plate-like or granular inorganic fillers of clay or the like.

  Organic fillers include synthetic fibers such as polyester fiber, nylon fiber, acrylic fiber, regenerated cellulose fiber, and acetate fiber, and natural fibers such as kenaf, ramie, cotton, jute, hemp, sisal, Manila hemp, flax, linen, silk, and wool. Examples thereof include fibrous organic fillers obtained from microcrystalline cellulose, sugar cane, wood pulp, paper waste, waste paper and the like, and granular organic fillers such as organic pigments.

  When the molding material contains a filler, the content is not limited, but is usually 30 parts by mass or less, preferably 5 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic cellulose composition.

  The molding material of the present invention may contain a flame retardant. Thereby, the flame retarding effect such as reduction or suppression of the burning rate can be improved. The flame retardant is not particularly limited, and a conventional flame retardant can be used. For example, brominated flame retardants, chlorine-based flame retardants, phosphorus-containing flame retardants, silicon-containing flame retardants, nitrogen compound-based flame retardants, inorganic flame retardants and the like can be mentioned. Among these, hydrogen halides are not generated by thermal decomposition during resin compounding or molding, and do not corrode processing machines or molds or deteriorate the working environment. Phosphorus-containing flame retardants and silicon-containing flame retardants are preferred because they are less likely to adversely affect the environment through the generation of harmful substances such as dioxins when they are diffused or decomposed.

  The phosphorus-containing flame retardant is not particularly limited, and a commonly used one can be used. Examples thereof include organic phosphorus compounds such as phosphate esters, phosphate condensation esters, and polyphosphates.

Specific examples of phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) Phosphate, tris (phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl Acid phosphate, 2-methacryloyloxyethyl acid phosphate, diphenyl Examples include 2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, diethyl phenylphosphonate be able to.

  Examples of phosphoric acid condensed esters include resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate, bisphenol A polycresyl phosphate, hydroquinone poly (2,6-xylyl) phosphate, and condensates thereof. Aromatic phosphoric acid condensed ester and the like.

  Moreover, the polyphosphate which consists of a salt of phosphoric acid, polyphosphoric acid, a periodic table group 1-14 group metal, ammonia, an aliphatic amine, and an aromatic amine can also be mentioned. As typical salts of polyphosphates, lithium salts, sodium salts, calcium salts, barium salts, iron (II) salts, iron (III) salts, aluminum salts and the like as metal salts, methylamine salts as aliphatic amine salts, Examples include ethylamine salts, diethylamine salts, triethylamine salts, ethylenediamine salts, piperazine salts, and examples of aromatic amine salts include pyridine salts and triazines.

  In addition to the above, halogen-containing phosphate esters such as trischloroethyl phosphate, trisdichloropropyl phosphate, tris (β-chloropropyl) phosphate), and structures in which a phosphorus atom and a nitrogen atom are connected by a double bond Phosphazene compounds having phosphoric acid and phosphoric ester amides. These phosphorus-containing flame retardants may be used singly or in combination of two or more.

  Examples of the silicon-containing flame retardant include an organic silicon compound having a two-dimensional or three-dimensional structure, polydimethylsiloxane, or a methyl group at a side chain or a terminal of polydimethylsiloxane, a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, Examples thereof include those substituted or modified with an aromatic hydrocarbon group, so-called silicone oils, or modified silicone oils.

  Examples of the substituted or unsubstituted aliphatic hydrocarbon group and aromatic hydrocarbon group include an alkyl group, a cycloalkyl group, a phenyl group, a benzyl group, an amino group, an epoxy group, a polyether group, a carboxyl group, a mercapto group, Examples include a chloroalkyl group, an alkyl higher alcohol ester group, an alcohol group, an aralkyl group, a vinyl group, or a trifluoromethyl group. These silicon-containing flame retardants may be used alone or in combination of two or more.

  Examples of the flame retardant other than the phosphorus-containing flame retardant or the silicon-containing flame retardant include, for example, magnesium hydroxide, aluminum hydroxide, antimony trioxide, antimony pentoxide, sodium antimonate, zinc hydroxystannate, zinc stannate, Metastannic acid, tin oxide, tin oxide salt, zinc sulfate, zinc oxide, ferrous oxide, ferric oxide, stannous oxide, stannic oxide, zinc borate, ammonium borate, ammonium octamolybdate, tungsten Inorganic flame retardants such as acid metal salts, complex oxides of tungsten and metalloid, ammonium sulfamate, ammonium bromide, zirconium compounds, guanidine compounds, fluorine compounds, graphite, and swellable graphite can be used. . These other flame retardants may be used alone or in combination of two or more.

  When the molding material of the present invention contains a flame retardant, the content thereof is not limited, but is usually 30 parts by mass or less, preferably 2 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic cellulose composition. Good. By setting it as this range, impact resistance, brittleness, etc. can be improved, or generation | occurrence | production of pellet blocking can be suppressed.

  The molding material of the present invention is for the purpose of further improving various properties such as moldability and flame retardancy within the range not impairing the object of the present invention, in addition to the thermoplastic cellulose composition, filler and flame retardant. Other components may be included. Examples of other components include polymers other than the polymer contained in the thermoplastic cellulose composition, stabilizers (antioxidants, ultraviolet absorbers, etc.), mold release agents (fatty acids, fatty acid metal salts, oxyfatty acids, fatty acid esters). , Aliphatic partially saponified ester, paraffin, low molecular weight polyolefin, fatty acid amide, alkylene bis fatty acid amide, aliphatic ketone, fatty acid lower alcohol ester, fatty acid polyhydric alcohol ester, fatty acid polyglycol ester, modified silicone), antistatic agent, difficult Examples include a combustion aid, a processing aid, an anti-drip agent, an antibacterial agent, and an antifungal agent. Further, a coloring agent containing a dye or a pigment can be added.

  When the molding material of the present invention contains a polymer other than the polymer contained in the thermoplastic cellulose composition, the content is preferably 30 parts by mass or less, more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the cellulose derivative. preferable.

  In the present invention, a mixture of cotton-like cellulose and granular alkyl cellulose is acylated with an acid anhydride, so that the use of a plasticizer is reduced or a simple method without using a plasticizer is good. A cellulose composition having excellent thermoplasticity and strength can be obtained, but a plasticizer may be contained in the molding material as long as the effects of the present invention are not impaired. Thereby, a flame retardance and a moldability can be improved further. As the plasticizer, those commonly used for polymer molding can be used. Examples thereof include polyester plasticizers, glycerin plasticizers, polycarboxylic acid ester plasticizers, polyalkylene glycol plasticizers, and epoxy plasticizers.

  The molded article of the present invention can be obtained by melt-molding a molding material containing the thermoplastic cellulose composition by heating. More specifically, the manufacturing method including a step of heating the thermoplastic cellulose composition or the molding material containing the thermoplastic cellulose composition and various additives as necessary, and molding by various molding methods. Obtained by. Examples of the molding method include injection molding, extrusion molding, blow molding and the like. The heating temperature is usually 160 to 300 ° C, preferably 180 to 260 ° C.

  The use of the molded product of the present invention is not particularly limited. For example, interior or exterior parts of electrical and electronic equipment (home appliances, OA / media related equipment, optical equipment, communication equipment, etc.), automobiles, mechanical parts, etc. And materials for housing and construction. Among these, from the viewpoint of having excellent heat resistance and impact resistance and low environmental impact, for example, exterior parts (especially casings) for electrical and electronic equipment such as copiers, printers, personal computers, and televisions. ) Can be suitably used.

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

(Preparation of cotton-like cellulose)
A softwood sulfite pulp roll (α-cellulose content 87%) was cut with a household shredder, and pulverized with an ultracentrifugal mill ZM-200 (manufactured by Lecce) at a rotational speed of 18000 rpm. Hereinafter, this cellulose is referred to as cotton-like cellulose.

The bulk density of the obtained cotton-like cellulose was measured as follows using a Lobe Pharma Electrolab Tap Density Tester (USP) model ETD-1020. However, the bulk density was 6 g / 100 ml.
1) The (empty) tare weight of a 100 ml USP1 graduated cylinder was measured within a range of ± 0.01 g.
2) In a 100 ml USP1 graduated cylinder, ˜90 ml of uncompressed cotton-like cellulose prepared above was placed.
3) This graduated cylinder was placed in a tap density tester and dropped (tapped) 200 times at a speed of 300 times / min.
4) The volume of cellulose obtained after tapping was visually measured within a range of ± 1 ml, and the weight of cotton-like cellulose was further measured within a range of ± 0.01 g.
5) The bulk density was calculated by dividing the weight of cottony cellulose by the volume of cellulose after tapping.

(Synthesis example)
<Example 1-1>
In a 5 L glass reaction vessel with stirring blades, 49 g of the above-prepared cotton cellulose, hydroxypropylmethylcellulose, which is granular alkylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd., bulk density 15 g of 35 g / 100 ml) was added, 24 g of glacial acetic acid was added, and the pretreatment was activated by vigorous stirring for 2 hours at normal temperature and normal pressure at a stirring speed of 200 rpm.
A mixed solution of 180 g of acetic anhydride, 240 g of glacial acetic acid, and 19.2 g of sulfuric acid was previously adjusted to 5 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixed solution to react. The temperature of the system was kept at 35 ° C. or lower and mixed with stirring for 4 hours. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. 53 g of water was added, the system temperature was adjusted to 50 ° C., and the mixture was stirred and mixed for 50 minutes. After adding 58 g of 24 wt% magnesium acetate aqueous solution and stirring for 25 minutes, 29 g was added and stirred for 10 minutes, 14.5 g was added, 20 minutes later, 7.25 g was added, and 20 g was added after 25 minutes. Then, water was dripped at room temperature and taken out. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. The cellulose composition (P-1) was obtained by drying.

<Example 2-1>
In a 5 L glass reaction vessel with stirring blades, 15 g of hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), which is granular alkyl cellulose, is used for 49 g of the cotton-like cellulose prepared above. In addition, 24 g of glacial acetic acid was added, and the pretreatment was activated by vigorous stirring for 2 hours at room temperature and normal pressure and a stirring speed of 200 rpm.
A mixture of 180 g of acetic anhydride, 240 g of glacial acetic acid, and 4.8 g of sulfuric acid was previously adjusted to 5 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixture to react. The temperature of the system was kept at 35 ° C. or lower and the mixture was stirred for 6 hours. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. 53 g of water was added, the system temperature was adjusted to 50 ° C., and the mixture was stirred and mixed for 50 minutes. 14.5 g of a 24 wt% magnesium acetate aqueous solution was added and stirred for 25 minutes, then 7.25 g was added and stirred for 10 minutes, 3.63 g was added, 20 minutes later, 1.81 g was added, and 10 g was added. Then, water was dripped at room temperature and taken out. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. The cellulose composition (P-2) was obtained by drying.

<Example 3-1>
In a 5 L glass reaction vessel with stirring blades, 15 g of hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), which is granular alkyl cellulose, is used for 49 g of the cotton-like cellulose prepared above. In addition, 24 g of glacial acetic acid was added, and the pretreatment was activated by vigorous stirring for 2 hours at room temperature and normal pressure and a stirring speed of 200 rpm.
A mixed solution of 144 g of acetic anhydride, 180 g of glacial acetic acid and 1.5 g of sulfuric acid was previously adjusted to −2 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixed solution and stirred. Mixed. The time when the pretreated activated cellulose is added is defined as 0 minute. After 30 minutes, the temperature in the reaction system was 30 ° C. At this time, a solution of 0.3 g of sulfuric acid / 18 g of acetic acid was added dropwise. After 50 minutes, the temperature in the reaction system was 62.5 ° C., and the mixture was further stirred for 15 minutes. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. After completion of the acylation reaction, 12 g of a 24 wt% magnesium acetate aqueous solution was added and stirred for 25 minutes. The contents were transferred to an autoclave and heated with 60 ml of warm water. After 90 minutes, the system temperature was 150 ° C., and the temperature was further maintained for 25 minutes, followed by reprecipitation with a large amount of dilute acetic acid aqueous solution. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. The cellulose composition (P-3) was obtained by drying.

<Example 4-1>
In a 5 L glass reaction vessel with stirring blades, 15 g of hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), which is granular alkyl cellulose, is used for 49 g of the cotton-like cellulose prepared above. In addition, 24 g of glacial acetic acid was added, and the pretreatment was activated by vigorous stirring for 2 hours at room temperature and normal pressure and a stirring speed of 200 rpm.
A mixed solution of 89 g of propionic acid, 21 g of acetic anhydride, 335 g of propionic anhydride, and 1.2 g of sulfuric acid was previously adjusted to 5 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixed solution. The mixture was stirred and mixed. The time when the pretreated activated cellulose is added is defined as 0 minute. After 30 minutes, the temperature in the reaction system was 30 ° C. At this time, a solution of 0.3 g of sulfuric acid / 18 g of acetic acid was added dropwise. After 50 minutes, the temperature in the reaction system was 61 ° C., and the mixture was further stirred for 15 minutes. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. After completion of the acylation reaction, 22 g of a 24 wt% magnesium acetate aqueous solution was added and stirred for 25 minutes. The contents were transferred to an autoclave and heated with 60 ml of warm water. After 90 minutes, the system temperature was 150 ° C., and the temperature was further maintained for 25 minutes, followed by reprecipitation with a large amount of dilute acetic acid aqueous solution. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. The cellulose composition (P-4) was obtained by drying.

<Example 5-1>
In a 5 L glass reaction vessel with stirring blades, 15 g of hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), which is granular alkyl cellulose, is used for 49 g of the cotton-like cellulose prepared above. In addition, 24 g of glacial acetic acid was added, and the pretreatment was activated by vigorous stirring for 2 hours at room temperature and normal pressure and a stirring speed of 200 rpm.
A mixed solution of 89 g of propionic acid, 21 g of acetic anhydride, 335 g of propionic anhydride, and 1.2 g of sulfuric acid was previously adjusted to 5 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixed solution. The mixture was stirred and mixed. The time when the pretreated activated cellulose is added is defined as 0 minute. After 30 minutes, the temperature in the reaction system was 30 ° C. At this time, a solution of 0.3 g of sulfuric acid / 18 g of acetic acid was added dropwise. After 50 minutes, the temperature in the reaction system was 62 ° C., and the mixture was further stirred for 15 minutes. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. After completion of the acylation reaction, 180 ml of an acetic acid aqueous solution (50 wt%) was added, the system temperature was set to 50 ° C., and the mixture was stirred and mixed for 50 minutes. 14.5 g of a 24 wt% magnesium acetate aqueous solution was added and stirred for 25 minutes, then 7.25 g was added and stirred for 10 minutes, 3.63 g was added, 20 minutes later, 1.81 g was added, and 10 g was added. Then, water was dripped at room temperature and taken out. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. The cellulose composition (P-5) was obtained by drying.

<Example 6-1>
The hydroxypropyl methylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) in Example 5-1 was changed to hydroxyethyl methylcellulose (trade name Marporose ME-350T; manufactured by Matsumoto Yushi) which is a granular alkyl cellulose. A cellulose composition (P-6) was obtained in the same manner as in Example 5-1.

<Example 7-1>
Hydroxypropyl methylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) in Example 5-1 was changed to hydroxyethyl cellulose (trade name HEC AX-15; manufactured by Sumitomo Seika), which is a granular alkyl cellulose. A cellulose composition (P-7) was obtained in the same manner as in Example 5-1.

<Example 8-1>
Example 5-1 except that hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) in Example 5-1 was changed to hydroxypropylcellulose (manufactured by Aldrich), which is granular alkylcellulose. A cellulose composition (P-8) was obtained by the same operation as above.

<Comparative Example 1-1>
-Synthesis of cellulose acetate (H-1)-
Pretreatment activation was performed by adding 24 g of glacial acetic acid to 60 g of the cotton-like cellulose prepared above in a 5 L glass reaction vessel with stirring blades and vigorously stirring for 2 hours at normal temperature and normal pressure at a stirring speed of 200 rpm.
A mixed solution of 144 g of acetic anhydride, 180 g of glacial acetic acid and 1.5 g of sulfuric acid was previously adjusted to 5 ° C. and prepared in a 3 L kneader, and the pretreated activated cellulose was added to this mixed solution and stirred and mixed. did. The time when the pretreated activated cellulose is added is defined as 0 minute. After 30 minutes, the temperature in the reaction system was 30 ° C. At this time, a solution of 0.3 g of sulfuric acid / 18 g of acetic acid was added dropwise. After 50 minutes, the temperature in the reaction system was 62 ° C., and the mixture was further stirred for 15 minutes. The reaction system changed from a bowl-like shape to a transparent candy-like shape. When the sampled sample was observed with a polarizing microscope, it was confirmed that the cellulose crystals had completely disappeared. This point was regarded as the end point of the acylation reaction. After completion of the acylation reaction, 180 ml of an acetic acid aqueous solution (50 wt%) was added, the system temperature was set to 50 ° C., and the mixture was stirred and mixed for 50 minutes. 14.5 g of a 24 wt% magnesium acetate aqueous solution was added and stirred for 25 minutes, then 7.25 g was added and stirred for 10 minutes, 3.63 g was added, 20 minutes later, 1.81 g was added, and 10 g was added. Then, water was dripped at room temperature and taken out. The obtained crude product was washed with water, washed with 0.002 wt% calcium hydroxide aqueous solution, and filtered. By drying, cellulose acetate (H-1) was obtained.

-Synthesis of acetoxypropylacetylmethylcellulose (H-2)-
Other than changing the cotton-like cellulose in the synthesis of cellulose acetate (H-1) to hydroxypropylmethylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) which is a granular alkyl cellulose, (H-1 ) To obtain acetoxypropylacetylmethylcellulose (H-2).

  By mixing 80 g of (H-1) and 20 g of (H-2) as powder, a cellulose composition (J-1) was obtained.

<Comparative Example 2-1>
-Synthesis of acetoxyethylacetylcellulose (H-3)-
Hydroxypropyl methylcellulose (trade name Marprose 90MP-4000: manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) in the synthesis of acetoxypropylacetylmethylcellulose (H-2) is hydroxyalkyl cellulose (trade name HEC AX-15; Sumitomo) Acetoxyacetoxyethyl acetylcellulose (H-3) was obtained in the same manner as in (H-2) except that the product was changed to Seikasei).

  80 g of (H-1) and 20 g of (H-3) were mixed to obtain a cellulose composition (J-2).

<Comparative Example 3-1>
The cellulose composition (J-3) was prepared in the same manner as in Example 1-1 except that the cotton-like cellulose in Example 1-1 was changed to KC Plock W-400G (granular cellulose: manufactured by Nippon Paper Industries Co., Ltd.). Obtained. In addition, when the bulk density of granular cellulose was measured by the same method as cotton-like cellulose, the bulk density was 30 g / 100 ml.

About the composition obtained above, the kind of functional group substituted with the hydroxyl group (R ² , R ³ and R ⁶ ) contained in cellulose, and the acylation degree are described in Cellulose Communication 6, 73-79 (1999). It was observed and determined by ¹ H-NMR using the described method.

(Measurement of molecular weight and molecular weight distribution of cellulose composition)
About the obtained cellulose composition, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured. These measuring methods are as follows.
For the measurement of the number average molecular weight (Mn) and the weight average molecular weight (Mw), gel permeation chromatography (GPC) was used. Specifically, N-methylpyrrolidone was used as a solvent, a polystyrene gel was used, and the molecular weight was determined using a conversion molecular weight calibration curve obtained in advance from a constituent curve of standard monodisperse polystyrene. As the GPC apparatus, HLC-8220 GPC (manufactured by Tosoh Corporation) was used.

  The number average molecular weight (Mn), the weight average molecular weight (Mw) and the degree of substitution are shown together in Table 1.

HPMC = hydroxypropylmethylcellulose (bulk density 35g / 100ml)
HEMC = hydroxyethylmethylcellulose (bulk density 33 g / 100 ml)
HEC = hydroxyethyl cellulose (bulk density 36g / 100ml)
HPC = hydroxypropylcellulose (bulk density 36g / 100ml)

(Production of molded body)
<Example 1-2: Production of molded body made of cellulose composition (P-1)>
-Preparation of resin pellets-
100 parts by mass of the cellulose composition (P-1) obtained above and 1 part by mass of calcium carbonate were kneaded at a cylinder temperature of 210 ° C., and then supplied to a twin-screw kneading extruder (manufactured by Technobel Corp., Ultrano). Thus, pellets of the cellulose composition were produced.

-Test piece preparation-
The cellulose composition pellets obtained above are supplied to an injection molding machine (manufactured by Imoto Seisakusho, semi-automatic injection molding machine) at a cylinder temperature of 200 ° C., a mold temperature of 30 ° C., and an injection pressure of 3 kgf / cm ² . A 4 × 10 × 80 mm multipurpose test piece (PT-1) was molded. The mold temperature was 30 ° C. The test piece PT-1 was in a good state with no coloring.

<Examples 2-2 to 8-2: Production of molded bodies made of cellulose compositions (P-2) to (P-8)>
Pellets of cellulose compositions (P-2) to (P-8) in the same manner as in Example 1 except that the cellulose composition (P-1) is changed to that shown in the following table in the method of Example 1. And multipurpose test pieces (PT-2) to (PT-8) were prepared. The test pieces PT-2 to 8 were all in a good state with no coloring.

<Comparative Example 1-2: Production of molded body made of cellulose composition (J-1)>
-Preparation of resin pellets-
When 100 parts by mass of the cellulose composition (J-1) obtained above and 1 part by mass of calcium carbonate were kneaded at a cylinder temperature of 210 ° C., pellets could not be produced due to insufficient thermoplasticity. Therefore, the mixture was kneaded at a cylinder temperature of 250 ° C. and supplied to a twin-screw kneading extruder (manufactured by Technobell, Ultrano) to produce pellets of a cellulose composition.

-Test piece preparation-
The cellulose composition pellets obtained above were supplied to an injection molding machine (manufactured by Imoto Seisakusho Co., Ltd., semi-automatic injection molding machine) and 4 at a cylinder temperature of 240 ° C., a mold temperature of 30 ° C., and an injection pressure of 3 kgf / cm ² . A multipurpose test piece (JT-1) of × 10 × 80 mm was molded. The mold temperature was 30 ° C. The test piece JT-1 was colored.

<Comparative Example 2-2: Production of molded body made of cellulose composition (J-2)>
-Preparation of resin pellets-
When 100 parts by mass of the cellulose composition (J-2) obtained above and 1 part by mass of calcium carbonate were kneaded at a cylinder temperature of 210 ° C., pellets could not be produced due to insufficient thermoplasticity. Therefore, the mixture was kneaded at a cylinder temperature of 250 ° C. and supplied to a twin-screw kneading extruder (manufactured by Technobell, Ultrano) to produce pellets of a cellulose composition.

-Test piece preparation-
The cellulose derivative composition pellets obtained above are supplied to an injection molding machine (Imoto Seisakusho, semi-automatic injection molding machine) at a cylinder temperature of 240 ° C., a mold temperature of 30 ° C., and an injection pressure of 3 kgf / cm ² . A 4 × 10 × 80 mm multipurpose test piece (JT-2) was molded. The mold temperature was 30 ° C. The test piece JT-2 was colored.

<Comparative Example 3-2: Production of molded body made of cellulose composition (J-3)>
-Preparation of resin pellets-
100 parts by mass of the cellulose composition (J-3) obtained above and 1 part by mass of calcium carbonate were kneaded at a cylinder temperature of 210 ° C., and then supplied to a twin-screw kneading extruder (manufactured by Technobel Corp., Ultrano). Thus, pellets of the cellulose composition were produced.

-Test piece preparation-
The cellulose composition pellets obtained above were supplied to an injection molding machine (manufactured by Imoto Seisakusho Co., Ltd., semi-automatic injection molding machine) and 4 at a cylinder temperature of 200 ° C., a mold temperature of 30 ° C., and an injection pressure of 3 kgf / cm ² . A multipurpose test piece (JT-3) of × 10 × 80 mm was molded. The mold temperature was 30 ° C. The test piece JT-3 was not colored.

(Measurement of physical properties of specimen)
About the obtained composition and test piece, the temperature at 10 ⁵ Pa · s, Charpy impact strength, and thermal deformation temperature (HDT) were evaluated according to the following methods. The results are shown in the table below.

-Temperature at 10 ⁵ Pa · s-
Using a flow tester (manufactured by Shimadzu), melt viscosity measurement was performed on each of the cellulose compositions of P-1 to P-8 and J-1 to J-3, and the temperature at 10 ⁵ Pa · s was measured. Here, when the temperature at 10 ⁵ Pa · s is 220 ° C. or less, it can be said that there is thermoplasticity, and it can be used within a range where there is no practical problem. The measurement results are shown in Table 2.

-Charpy impact strength-
In accordance with ISO 179, each test piece of PT-1 to PT-8 and JT-1 to JT-3 molded by injection molding has an incident angle of 45 ± 0.5 ° and a tip of 0.25 ± 0.05 mm. A notch was formed and allowed to stand for 48 hours or more at 23 ° C. ± 2 ° C. and 50% ± 5% RH, and then the impact strength was measured edgewise with a Charpy impact tester (manufactured by Toyo Seiki Seisakusho). The measurement is an average of three measurements. Here, when the Charpy impact strength is 5 KJ / m ² or more, it can be said that there is sufficient strength, and it can be used within a range that does not cause any problem in practice. The measurement results are shown in Table 2.

-Thermal deformation temperature (HDT)-
In accordance with ISO75, a constant bending load (1.8 MPa) is applied to the center of each test piece of PT-1 to PT-8 (in the flatwise direction), the temperature is increased at a constant speed, and the strain at the center is 0. The temperature when it reached 34 mm was measured. The measurement results of PT-1 to PT-8 were 114 ° C., 115 ° C., 118 ° C., 105 ° C., 107 ° C., 103 ° C., 105 ° C., and 102 ° C., respectively, and showed excellent heat resistance.

  As is clear from the above results, in the present invention, a mixture of cotton-like cellulose and granular alkyl cellulose is acylated with an acid anhydride, so that no kneading or the like is performed without using a plasticizer. In this way, a cellulose composition having good thermoplasticity and strength was successfully produced. Moreover, problems such as transpiration of a plasticizer could be solved by using the method for producing a thermoplastic cellulose composition of the present invention. Furthermore, it turned out that the thermoplastic cellulose composition which was not colored and was excellent also in heat resistance can be obtained by setting it as the structure of this invention.

Claims (8)

  A method for producing a thermoplastic cellulose composition, comprising an acylation step of acylating a mixture of cotton-like cellulose and granular alkyl cellulose with an acid anhydride.   The production method according to claim 1, wherein the alkyl cellulose has an alkyl group having 1 to 4 carbon atoms.   The manufacturing method according to claim 1 or 2, wherein the acid anhydride contains at least one selected from the group consisting of acetic anhydride, propionic anhydride and butyric anhydride.   The manufacturing method of any one of Claims 1-3 using a sulfuric acid or methanesulfonic acid as a catalyst in the said acylation.   The said alkyl cellulose contains at least 1 sort (s) chosen from the group which consists of hydroxypropylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylethylcellulose, and hydroxyethylethylcellulose. Manufacturing method.   The mixing ratio of cotton-like cellulose and granular alkyl cellulose (cotton-like cellulose / granular alkyl cellulose) in the mixture is 100/50 to 100/10 on a mass basis. The manufacturing method as described in. Prior to the acylation step according to any one of claims 1 to 6,
The manufacturing method of any one of Claims 1-6 provided with the pre-processing process which adds an acidic compound to the said mixture.   The manufacturing method of the molded object provided with the process of melt-molding the molding material containing the thermoplastic cellulose composition obtained by the manufacturing method of any one of Claims 1-7 by heating.