JP6977544B2 - Cellulose ester resin composition and its molded product - Google Patents

Description

The present invention relates to a molded body having excellent transparency, moisture permeability, and good plasticity, particularly a cellulose ester resin composition for obtaining a film, and a molded body and a film obtained by using the resin composition.

Cellulose ester resin is obtained from plant-derived raw materials, is generally tougher than other synthetic resins, has excellent transparency, luster, luster, chemical resistance, and moisture permeability, and has a smooth surface and a good feel. It has a great feature. For this reason, the resin has a wide variety of uses, for example, sheets, films, electric wire coatings, toys, medical devices, electronic devices, food packaging materials, and the like.

In recent years, taking advantage of the high transparency and moisture permeability of cellulose esters, application to humidity control films, antifogging films, food packaging materials and the like has been considered.

However, since the cellulose ester resin has poor plasticity and is hard and brittle, it has a problem that it cannot be used in applications requiring high flexibility. Therefore, in order to avoid this, it is necessary to add an appropriate plasticizer to lower the softening point of the cellulose-based resin, and for this purpose, conventionally, for example, triphenyl phosphate, tricresyl phosphate, diphenyl phosphate, triethyl Phosphate, tributyl phosphate, dimethyl phthalate, diethyl phthalate, dimethoxyethyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, toluene sulfonamide, triacetin, pentaerythritol tetraacetate and the like have been used.

However, these plasticizers are compatible with cellulosic resins, plasticizing efficiency, transparency, moisture permeability, water resistance, heat resistance, non-volatile, heat and light stability, non-migration, non-extractability. There is nothing that can satisfy a wide range of performance such as. In particular, in order to eliminate the hardness and brittleness while maintaining the high moisture permeability of the cellulosic resin, it is necessary to add a large amount of the plasticizer, but the problem is that the plasticizer bleeds out. ..

As means for solving these problems, for example, an ester compound obtained by reacting a polybasic acid with a polyhydric alcohol and an ether alcohol (see, for example, Patent Document 1), a structural unit derived from an aliphatic dibasic acid, and the like. An ester compound consisting of a structural unit derived from an alkylene diol and a structural unit derived from a polyalkylene ether glycol and consisting of a random copolymer having a hydroxyl group or a carboxyl group at the end (see, for example, Patent Document 2) is cellulose-based. It is offered to be used as a resin modifier.

However, sufficient moisture permeability cannot be obtained when the compound actually provided in Patent Document 1 is used as a modifier, and when the compound actually provided in Patent Document 2 is used as a modifier. However, the moisture permeability and compatibility with the cellulosic resin have not reached a level applicable to, for example, food packaging materials, and further improvement is required.

Japanese Unexamined Patent Publication No. 2009-173740 Japanese Unexamined Patent Publication No. 2017-145275

The problem to be solved by the present invention is a cellulose ester resin composition that can obtain a molded body or film having excellent transparency, moisture permeability, compatibility, and good plasticity, and a molded body obtained by using the resin composition. Is to provide.

As a result of diligent studies, the present inventors have made dihydric alcohols, dibasic acids, and polyalkylene glycol monoalkyl ethers having a number average molecular weight of 150 to 5000 (however, the number of carbon atoms of the terminal alkyl group is 1 to 1). By using the condensation reaction product with (6) as a modifier for the cellulose ester resin, a molded product having excellent moisture permeability without impairing the transparency of the cellulose ester resin, particularly a film, can be obtained and moist heat can be obtained. Later, they found that the change in transparency was small and the plasticizing effect was good, and the present invention was completed.

That is, the present invention is a cellulose ester resin composition containing a cellulose ester resin (A) and an ester compound (B).
The ester compound (B) is
Dihydric alcohol (b1), dibasic acid (b2), and polyalkylene glycol monoalkyl ether having a number average molecular weight of 150 to 5000 (however, the terminal alkyl group has 1 to 6 carbon atoms) (b3). ), A cellulose ester resin composition, and a molded product containing the resin composition.

According to the present invention, it is possible to provide a resin composition which is excellent in transparency and moisture permeability, has good plasticity, and can be suitably used for food packaging materials and the like. By using this resin composition, it is possible to obtain a molded product having excellent transparency, moisture permeability, and plasticity, particularly a film having the performance.

The cellulose ester resin (A) used in the present invention is not particularly limited, and for example, a part or all of the hydroxyl groups of cellulose obtained from cotton linter, wood pulp, kenaf, etc. are esterified. Can be exemplified.

Examples of the cellulose ester resin (A) include cellulose acetate, cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB), cellulose acetate phthalate, cellulose acetate stearate, cellulose acetate benzoate, cellulose nitrate, and polycaprolactone. Examples thereof include grafted cellulose acetate, and when used as a molded body or film, cellulose acetate or cellulose acetate propionate (from the viewpoint of obtaining a molded body or film having excellent mechanical properties and transparency). CAP) and cellulose acetate butyrate (CAB) are preferable, and cellulose acetate is more preferable. These cellulose ester resins (A) may be used alone or in combination of two or more.

The cellulose ester resin (A) preferably has an average degree of polymerization in the range of 50 to 2000, and the average degree of acetyl substitution is preferably in the range of 2.0 to 3.0, more preferably. It is in the range of 2.2 to 3.0.

As long as the degree of polymerization and the degree of average substitution of the cellulose ester resin (A) are within the range, a molded body and a film having excellent mechanical properties can be obtained. In the present invention, it is more preferable to use so-called cellulose triacetate (TAC) or cellulose diacetate (DAC). The "average degree of acetyl substitution" in the present invention is a value measured according to ASTM D-817-91.

The number average molecular weight of the cellulose acetate is preferably in the range of 5,000 to 1,000,000, more preferably in the range of 10,000 to 500,000, and most preferably in the range of 10,000 to 200,000. When the number average molecular weight of the cellulose acetate is in this range, a film having excellent mechanical properties can be easily obtained.

Here, in the present invention, the number average molecular weight (Mn) is a value converted to polystyrene based on GPC measurement. The measurement conditions of GPC are as follows.

[GPC measurement conditions]
Measuring device: High-speed GPC device "HLC-8320GPC" manufactured by Tosoh Corporation
Column: "TSK GURDCOLUMN SuperHZ-L" manufactured by Tosoh Corporation + "TSK gel SuperHZM-M" manufactured by Tosoh Corporation + "TSK gel SuperHZM-M" manufactured by Tosoh Corporation + "TSK gel SuperHZ-2000" manufactured by Tosoh Corporation "TSK gel SuperHZ-2000" manufactured by Tosoh Corporation
Detector: RI (Differential Refractometer)
Data processing: "EcoSEC Data Analysis version 1.07" manufactured by Tosoh Corporation
Column temperature: 40 ° C
Developing solvent: Tetrahydrofuran Flow velocity: 0.35 mL / min Measurement sample: 7.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran, and the obtained solution was filtered through a microfilter to obtain a measurement sample.
Sample injection amount: 20 μl
Standard sample: According to the measurement manual of the above-mentioned "HLC-8320GPC", the following monodisperse polystyrene having a known molecular weight was used.

(Polystyrene monodisperse)
"A-300" manufactured by Tosoh Corporation
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
"F-288" manufactured by Tosoh Corporation

The ester compound (B) used in the present invention is a dihydric alcohol (b1), a dibasic acid (b2), and a polyalkylene glycol monoalkyl ether having a number average molecular weight of 150 to 5000 (provided that the carbon of the terminal alkyl group is carbon). The number of atoms is 1 to 6), which is a condensation reaction product with (b3).

Examples of the dihydric alcohol (b1) include alkylene glycol and oxyalkylene glycol. Examples of the alkylene glycol include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, and 1 , 4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylo-) Lupentane), 2-n-butyl-2-ethyl-1,3propanediol (3,3-dimethylolheptan), 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2 4-trimethyl 1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12- Examples thereof include alkylene glycols having 2 to 15 carbon atoms such as dodecanediol and hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane). These may be used alone or in combination of two or more.

Examples of the oxyalkylene glycol include oxyalkylene glycols having 4 to 12 carbon atoms such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. These may be used alone or in combination of two or more.

Among these, it is preferable to use alkylene glycol having 2 to 6 carbon atoms, cyclohexanedimethanol, and hydrogenated bisphenol A because a film having excellent transparency and moisture permeability can be obtained. Among alkylene glycols having 2 to 6 carbon atoms, ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 3-Methyl-1,5-pentanediol and 2-butyl-2-ethyl-1,3-propanediol are preferable from the viewpoint of obtaining a molded product having more excellent plasticity, particularly a film.

As the dibasic acid (b2), any of aromatic, aliphatic, and alicyclic dibasic acids may be used, for example, an alkylene dicarboxylic acid having 2 to 12 carbon atoms or 6 to 12 carbon atoms. The aryldicarboxylic acid of the above can be mentioned. However, this number of carbon atoms does not include the carbon atom in the carboxy group.

Examples of the alkylene dicarboxylic acid having 2 to 12 carbon atoms include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecandicarboxylic acid, cyclohexanedicarboxylic acid and the like. Examples of the aryldicarboxylic acid having 6 to 12 atoms include phthalic acid, terephthalic acid, isophthalic acid, dimethyl terephthalate, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 1,4-naphthalenedicarboxylic acid. And so on. These may be used alone or in combination of two or more. Further, when the ester compound (B) used in the present invention is synthesized by a transesterification reaction, a derivative such as an alkyl ester of these dibasic acids may be used as a raw material.

Among these, an alkylene dicarboxylic acid having 2 to 6 carbon atoms or an aryldicarboxylic acid having 6 to 10 carbon atoms is preferable because a film having excellent transparency and moisture permeability can be obtained, and phthalic acid, cyclohexanedicarboxylic acid, and adipine are preferable. It is more preferable to use an acid or a succinic acid, and it is most preferable to use an adipic acid or a succinic acid in an amount of 10 mol% or more in the dibasic acid (b2) used as a raw material.

The polyalkylene glycol monoalkyl ether (b3) has an alkyl group constituting the terminal alkyl ether in the range of 1 to 6 carbon atoms and its number average molecular weight in the range of 150 to 5000, and has a number of 150 to 5000. 3000 is preferable, and 150 to 2000 is particularly preferable. By using such a specific polyalkylene glycol monoalkyl ether, the cellulose ester resin (A) exhibits high moisture permeability, the hardness and brittleness of the cellulose ester resin (A) are eliminated, and the cellulose ester resin (A) is used. ) Is also excellent, so that the moisture permeability, transparency and plasticity of the obtained molded body and film are good.

The carbon atom number of the alkylene glycol portion in the polyalkylene glycol monoalkylene ether (b3) is preferably in the range of 1 to 6, particularly preferably in the range of 1 to 4, and constitutes ethylene glycol or propylene glycol. Most preferably, it is a unit.

The alkyl group constituting the terminal alkyl ether is in the range of 1 to 6 carbon atoms, but preferably 1 to 4 carbon atoms, and particularly is a methyl ether having 1 carbon atom. It is preferable from the viewpoint that a molded body and a film having more excellent moisture permeability can be easily obtained.

By using such a polyalkylene glycol monoalkylene ether (b3), the ester compound (B) has an ester bond between the hydroxyl group at the terminal opposite to the alkylene ether portion of the (b3) and the dibasic acid (b2). It becomes a structure sealed by. The ester compound (B) of the present invention is a linear compound, but even if one end is sealed with this polyalkylene glycol monoalkylene ether (b3), both ends are sealed. However, it is preferable that the ester compound has a structure in which both ends are sealed, because it is more excellent in balance between transparency, moisture permeability and plasticity.

The compound whose one end is sealed with a polyalkylene glycol monoalkylene ether (b3) may have the other end as a hydroxyl group or a carboxy group derived from a raw material, or a monoalcohol. The structure may be sealed with a monocarboxylic acid. Examples of the monoalcohol that can be used at this time include methanol, ethanol, propanol, butanol, hepanol, hexanol, cyclohexanol, heptonol, octanol, nonanol, decanol, undecanol, dodecanol and the like, and examples of the monocarboxylic acid include monocarboxylic acids. For example, benzoic acid, dimethyl benzoic acid, trimethyl benzoic acid, tetramethyl benzoic acid, ethyl benzoic acid, propyl benzoic acid, butyl benzoic acid, cumic acid, paratasial butyl benzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, ethoxy. Benzoic acid, propoxybenzoic acid, naphthoic acid, anisic acid, etc., aromatic compounds such as their methyl esters and acidified products, and aliphatic compounds such as acetic acid, propionic acid, butanoic acid, hexane acid, cyclohexanecarboxylic acid, etc. Can be mentioned.

From this point of view, the ester compound (B) used in the present invention has the following general formula (1).

（式中、Ｇはアルキレングリコール残基又はオキシアルキレングリコール残基であり、Ａはそれぞれ独立にアルキレンジカルボン酸残基又はアリールジカルボン酸残基であり、Ｒ^１はそれぞれ独立に炭素原子数１〜６のアルキル基であり、Ｒ^２はそれぞれ独立に炭素原子数１〜６のアルキル基である。ｍはそれぞれ独立に１以上の整数であり、ｎは０以上の整数であって、繰り返しごとに、Ａ、Ｇ、Ｒ^１は同一でも異なっていてもよい。）
で表される化合物であることが好ましい。

(In the formula, G is an alkylene glycol residue or an oxyalkylene glycol residue, A is an alkylene dicarboxylic acid residue or an aryldicarboxylic acid residue, ^{respectively, and R 1} is an independently having 1 to 6 carbon atoms. ^{R 2} is an alkyl group having 1 to 6 carbon atoms independently. M is an integer of 1 or more independently, n is an integer of 0 or more, and each repetition. A, G, and R ¹ may be the same or different.)
It is preferably a compound represented by.

In the present invention, the alkylene dicarboxylic acid residue or the aryldicarboxylic acid residue refers to a portion obtained by removing the carboxy group or the carboxy group derivative from the raw material dicarboxylic acid or a derivative thereof such as an alkyl ester, and the alkylene glycol residue or the alkylene glycol residue or the derivative thereof. The oxyalkylene glycol residue indicates a raw material alkylene glycol or a portion obtained by removing a hydroxyl group from the oxyalkylene glycol.

Among these, G in the general formula (1) is an alkylene glycol residue having 2 to 6 carbon atoms, a cyclohexanedimethanol residue or a hydrogenated bisphenol A residue, and A is a hydrogenated bisphenol A residue having 2 to 6 carbon atoms. An alkylene dicarboxylic acid residue or an aryldicarboxylic acid residue having 6 to 8 carbon atoms, R ¹ is an alkyl group having 2 to 3 carbon atoms, and R ² is an alkyl group having 1 to 4 carbon atoms. It is preferable to use a compound because it is excellent in the balance of transparency, moisture permeability and plasticity in the obtained molded product and film.

In the general formula (1), n and m indicate the number of repetitions, respectively, and it is preferable that n is 2 to 20 and m is 4 to 50 on average.

The number average molecular weight (Mn) of the ester compound (A) used in the present invention is preferably 400 to 4000. When the number average molecular weight is in this range, it is easy to obtain a molded body and a film having better transparency, moisture permeability, and plasticity. From this point of view, the number average molecular weight is particularly preferably in the range of 500 to 3000.

The ester compound (B) used in the present invention may be a single compound, a mixture of compounds having different numbers of repetitions of m and n, or A in the general formula (1). , G, R ¹ and R ² may be a mixture of different compounds.

The acid value of the ester compound (B) used in the present invention is preferably 5 or less, and more preferably 1 or less, from the viewpoint that a molded product and a film having sufficient strength can be easily obtained. Further, the hydroxyl value of the ester compound is preferably 50 or less, more preferably 20 or less, from the viewpoint that a composition having better stability against heat during molding and film formation can be easily obtained.

The ester compound (B) used in the present invention can be easily obtained, for example, by using the usual esterification method shown below.
Method 1: A dihydric alcohol (b1), a dibasic acid (b2), and a polyalkylene glycol monoalkyl ether having a number average molecular weight of 150 to 5000 (provided that the terminal alkyl group has 1 to 6 carbon atoms. ) (B3) are charged in a batch and these are reacted.
Method 2: After reacting a dihydric alcohol (b1) and a dibasic acid (b2) under a condition that the equivalent of a hydroxyl group is less than the equivalent of a carboxyl group to obtain an ester compound intermediate at the terminal of a carboxy group. , A method of reacting the intermediate with a polyalkylene glycol monoalkyl ether having a number average molecular weight of 150 to 5000 (provided that the terminal alkyl group has 1 to 6 carbon atoms) (b3).

As a method for obtaining the ester compound (B) used in the present invention by the esterification method, for example, the above-mentioned raw materials are used in the presence of an esterification catalyst, for example, in a temperature range of 180 to 250 ° C. Examples thereof include a method of reacting for 10 to 25 hours. Conditions such as the temperature and time of the esterification reaction are not particularly limited and may be set as appropriate.

Examples of the esterification catalyst include titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate; tin-based catalysts such as dibutyltin oxide; and organic sulfonic acid-based catalysts such as p-toluenesulfonic acid.

The amount of the esterification catalyst used may be appropriately set, but it is usually preferable to use the esterification catalyst in the range of 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the total amount of the raw material.

The properties of the ester compound (B) used in the present invention vary depending on factors such as number average molecular weight and composition, but are usually liquid, solid, paste or the like at room temperature.

The content of the ester compound (B) in the cellulose ester resin composition of the present invention depends on the properties such as moisture permeability of the target film, but in order to make it more plastic, it is a cellulose ester resin. (A) 1 to 70 parts by mass is preferable with respect to 100 parts by mass, and 5 to 50 parts by mass is more preferable.

A resin other than the cellulose ester resin (A) and the ester compound (B) can be mixed with the cellulose ester resin composition of the present invention within a range that does not impair the object of the present invention, for example, polyethylene, polypropylene and the like. Polystyrene; Polystyrene resin such as polystyrene, styrene acrylonitrile copolymer; Polyamide, polyphenylene sulfide resin, polyether ether ketone resin, polyester other than ester compound (B), polysulfone, polyphenylene oxide, polyimide, polyetherimide, polyacetal, Thermoplastic resins such as acrylic and urethane; thermosetting resins such as phenol resin, melamine resin, silicone resin and epoxy resin can be mentioned. These may be a mixture of one type or two or more types.

Various additives can be used in the cellulose ester resin composition of the present invention as long as the object of the present invention is not impaired.

Examples of the additive include a modifier other than the ester compound (B) used in the present invention, a thermoplastic resin, an ultraviolet absorber, a matting agent, a deterioration inhibitor, a flame retardant, a filler, a filler, a colorant, and a cross-linking agent. Examples thereof include agents, antistatic agents, plate-out inhibitors, surface treatment agents, lubricants, fluorescent agents, fungicides, bactericides, metal deactivating agents, mold release agents, pigments, processing aids, foaming agents and the like.

Examples of the modifier other than the ester compound (B) include phosphate esters such as triphenyl phosphate (TPP), tricresyl phosphate, and cresyl diphenyl phosphate; dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and di-2. -Phthalate esters such as ethylhexyl phthalate; examples thereof include ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, trimethylol propanetribenzoate, pentaerythritol tetraacetate, acetyl citrate tributyl and the like. These may be used alone or in combination of two or more.

The thermoplastic resin is not particularly limited, and examples thereof include polyester resins other than the ester compound (B) used in the present invention, polyester ether resins, urethane resins, epoxy resins, toluene sulfonamide resins, acrylic resins and the like.

Examples of the ultraviolet absorber include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salt compounds and the like.

The matting agent is not particularly limited, and examples thereof include silicon oxide, titanium oxide, aluminum oxide, calcium carbonate, calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, kaolin, and talc.

Examples of the deterioration inhibitor include, but are not limited to, antioxidants, peroxide decomposing agents, radical inhibitors, metal deactivating agents, acid trapping agents and the like.

The flame retardant is not particularly limited, and examples thereof include halogen-based compounds, phosphoric acid esters, condensed phosphoric acid esters, organic phosphorus-based compounds such as polyphosphates, and inorganic particles such as metal hydroxides.

The filler is not particularly limited, and examples thereof include inorganic or organic substances such as fibrous, plate-like, granular, and powder-like.

The cellulose ester resin composition of the present invention may contain the cellulose ester resin (A) and the ester compound (B), and the production method thereof is not particularly limited. Specifically, for example, the cellulose ester resin (A) and the ester compound (B), and if necessary, the additives and other resins are used in a single-screw extruder, a twin-screw extruder, a Banbury mixer, a brabender, and the like. It can be obtained by a method of melt-kneading using a melt-kneading machine such as various kneaders. Further, the cellulose ester resin composition of the present invention can also be obtained as a solution by dissolving the cellulose ester resin (A), the ester compound (B) and the above additives or resins in an organic solvent, if necessary. .. As the organic solvent, for example, an organic solvent used for obtaining a dope solution containing the cellulose ester resin (A) and the ester compound (B) in the solution flow method (solvent cast method) described later can be used.

The molded product of the present invention is obtained by molding the cellulose ester composition of the present invention. As a method for producing a molded product of the present invention, a known method can be adopted, and examples thereof include various methods such as injection molding, extrusion molding, blow molding, inflation molding, extrusion laminating molding, calendar molding, and powder molding. Not particularly limited. The molding temperature may be appropriately set depending on various conditions such as the properties of the cellulose ester composition to be molded and the molding method, and is not particularly limited, but is usually preferably in the range of 180 to 250 ° C., more preferably 200. It is in the range of ~ 230 ° C.

The molded product of the present invention may be in the form of a film, and is characterized by containing the cellulose ester resin composition of the present invention. In order to obtain the film of the present invention, for example, techniques such as extrusion molding and cast molding are used. Specifically, for example, an extruder equipped with a T-die, a circular die, or the like can be used to extrude the unstretched film. When a film is obtained by extrusion molding, the cellulose ester resin composition of the present invention obtained by melt-kneading the cellulose ester resin (A) and the ester compound (B) in advance can be used, or the cellulose ester resin composition of the present invention can be used at the time of extrusion molding. The cellulose ester resin (A) and the ester compound (B) can be melt-kneaded and extruded as they are. Further, the cellulose ester resin (A) and the ester compound (B) are dissolved in the solvent using a solvent that dissolves the cellulose ester resin (A) and the ester compound (B) component to obtain a so-called dope solution. After that, an unstretched film can also be obtained by a solution casting method (solvent casting method) in which cast molding is performed.

The solution casting method will be described in detail below. The film obtained by the solution casting method is less likely to form irregularities on its surface and has excellent surface smoothness, and can be used for, for example, various packaging materials.

The solution casting method generally includes a first step of dissolving the cellulose ester resin (A) and the ester compound (B) in an organic solvent and casting the obtained resin solution on a metal support. The second step of distilling off the organic solvent contained in the cast resin solution and drying to form a film, followed by peeling the film formed on the metal support from the metal support and heating and drying. Including the third step of making.

Examples of the metal support used in the first step include endless belt-shaped or drum-shaped metal supports, and for example, stainless steel having a mirror-finished surface thereof can be used. ..

When the resin solution is cast on the metal support, it is preferable to use a resin solution filtered through a filter in order to prevent foreign matter from being mixed in the obtained film.

The drying method in the second step is not particularly limited, but is included in the cast resin solution by, for example, blowing air in a temperature range of 30 to 50 ° C. on the upper surface and / or the lower surface of the metal support. A method of evaporating 50 to 80% by mass of the organic solvent to form a film on the metal support can be mentioned.

Next, the third step is a step of peeling the film formed in the second step from the metal support and heating and drying it under a temperature condition higher than that of the second step. As the heat-drying method, for example, a method of gradually increasing the temperature under a temperature condition of 100 to 160 ° C. is preferable because good dimensional stability can be obtained. By heating and drying under the above temperature conditions, the organic solvent remaining in the film after the second step can be almost completely removed.

The organic solvent recovered in the first to third steps can be reused.

The organic solvent that can be used when the cellulose ester resin (A) and the ester compound (B) are mixed and dissolved in an organic solvent is not particularly limited as long as they can be dissolved, but for example, chloroform and dichloride. Examples thereof include solvents such as methylene and methylene chloride.

The concentration of the cellulose ester resin (A) in the resin solution is preferably 10 to 50% by mass, more preferably 15 to 35% by mass.

The film thickness of the film of the present invention is preferably in the range of 20 to 200 μm, more preferably in the range of 25 to 150 μm, and particularly preferably in the range of 25 to 100 μm.

In the present invention, for example, the unstretched film obtained by the above method is stretched by vertical uniaxial stretching in the mechanical flow direction and horizontal uniaxial stretching in the direction perpendicular to the mechanical flow direction, if necessary. You can get the film. Further, a stretched film can be obtained by stretching by a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method by tenter stretching, a biaxial stretching method by tubular stretching, or the like. The draw ratio is preferably 0.1% or more and 1000% or less in at least one direction, more preferably 0.2% or more and 600% or less, and preferably 0.3% or more and 300% or less. Especially preferable. By designing in this range, a stretched film preferable from the viewpoint of moisture permeability and strength can be obtained.

The film of the present invention has excellent moisture permeability, and for example, ^{a film having a moisture permeability of 550 m 2} / g for 24 hours or more at a thickness of 60 μm can be preferably obtained. Such a moisture-permeable film can be used as a humidity control film, an anti-fog film, and can be suitably used as a food packaging material or the like.

Further, the film of the present invention is also excellent in plasticity, and for example, a film having a tensile elongation of 12% or more and a tensile elastic modulus of 4000 MPa or less can be preferably obtained. From the viewpoint of having such plasticity and excellent transparency, it can be used as various packaging materials.

Hereinafter, the present invention will be described in more detail based on examples. Parts and% in the example are based on mass unless otherwise specified.

Synthesis example 1
In a 500 ml four-necked flask, 113.0 g of ethylene glycol (hereinafter abbreviated as "EG") as a dihydric alcohol (b1) and 212.6 g of succinic acid (hereinafter abbreviated as "SuA") as a dibasic acid (b2). As polyethylene glycol monomethyl ether, 70.4 g of Himol PM (number average molecular weight 220) manufactured by Toho Kagaku Kogyo Co., Ltd. and 0.025 g of tetraisopropyl titanate (hereinafter abbreviated as "TIPT") as a catalyst are charged, and a nitrogen stream is introduced from a nitrogen introduction tube. Below, the temperature was gradually raised to 230 ° C. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-1) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-1) was a pale yellow liquid at room temperature, had an acid value of 0.24, a hydroxyl value of 13, and had a number average molecular weight of 950.

Synthesis example 2
In a 500 ml 4-necked flask, 85.7 g of EG as dihydric alcohol (b1), 165.4 g of SuA as dibasic acid (b2), and Uniox M-400 (number average molecular weight 400) manufactured by Nikko Co., Ltd. as polyethylene glycol monomethyl ether. ) 128.0 g and 0.023 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. from a nitrogen introduction tube under a nitrogen stream. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-2) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-2) was a pale yellow liquid at room temperature, had an acid value of 0.18, a hydroxyl value of 15, and had a number average molecular weight of 1330.

Synthesis example 3
In a 500 ml four-necked flask, 116.1 g of EG as dihydric alcohol (b1), 213.1 g of SuA as dibasic acid (b2), 92.0 g of Uniox M-400 as polyethylene glycol monomethyl ether, and 0.025 g of TIPT as a catalyst. Was charged, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from the nitrogen introduction pipe. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-3) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-3) was a pale yellow liquid at room temperature, had an acid value of 0.12, a hydroxyl value of 20, and had a number average molecular weight of 1250.

Synthesis example 4
In a 500 ml four-necked flask, 56.6 g of EG as dihydric alcohol (b1) and 119.9 g of 2-butyl 2-ethyl 1,3-propanediol, 192.8 g of SuA as dibasic acid (b2), and polyethylene glycol monomethyl ether. As a result, 109.2 g of Uniox M-400 and 0.028 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-4) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-4) was a pale yellow liquid at room temperature, had an acid value of 0.11, a hydroxyl value of 18, and had a number average molecular weight of 1480.

Synthesis example 5
In a 500 ml four-necked flask, 95.3 g of EG as dihydric alcohol (b1), 230.4 g of adipic acid (hereinafter abbreviated as "AA") as dibasic acid (b2), and Uniox M-400 as polyethylene glycol monomethyl ether. 96.0 g and 0.025 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. from a nitrogen introduction tube under a nitrogen stream. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-5) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-5) was a pale yellow liquid at room temperature, had an acid value of 0.15, a hydroxyl value of 18, and had a number average molecular weight of 2350.

Synthesis example 6
In a 500 ml four-necked flask, 46.3 g of EG as dihydric alcohol (b1) and 60.7 g of 1,3-butanediol, 214.3 g of dibasic acid (b2), and Uniox M-400 as polyethylene glycol monomethyl ether. 96.0 g and 0.025 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. from a nitrogen introduction tube under a nitrogen stream. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-6) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-6) was a pale yellow liquid at room temperature, had an acid value of 0.15, a hydroxyl value of 18, and had a number average molecular weight of 2680.

Synthesis example 7
In a 500 ml 4-necked flask, 47.7 g of EG as dihydric alcohol (b1), 101.8 g of SuA as dibasic acid (b2), and MPG-081 (number average molecular weight 680) 246 manufactured by Nippon Emulsifying Co., Ltd. as polyethylene glycol monomethyl ether. 0.9 g and 0.024 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-7) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-7) was a pale yellow liquid at room temperature, had an acid value of 0.68, a hydroxyl value of 8, and had a number average molecular weight of 2050.

Synthesis example 8
In a 500 ml four-necked flask, 84.9 g of EG as dihydric alcohol (b1), 159.2 g of SuA as dibasic acid (b2), MPG-081 157.7 g as polyethylene glycol monomethyl ether, and 0.024 g of TIPT as a catalyst are charged. The temperature was gradually raised to 230 ° C. under a nitrogen stream from the nitrogen introduction pipe. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-8) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-8) was a pale yellow liquid at room temperature, had an acid value of 0.2, a hydroxyl value of 16, and had a number average molecular weight of 1860.

Synthesis example 9
In a 500 ml 4-necked flask, 70.6 g of EG as dihydric alcohol (b1), SuA139.2 g as dibasic acid (b2), and Uniox M-1000 (number average molecular weight 1000) manufactured by Nikko Co., Ltd. as polyethylene glycol monomethyl ether. ) 320.0 g and 0.032 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. from a nitrogen introduction tube under a nitrogen stream. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-9) of the present invention was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B-9) was a pale yellow liquid at room temperature, had an acid value of 0.2, a hydroxyl value of 11, and had a number average molecular weight of 2310.

Comparative synthesis example 1
94.0 g of EG, 221.2 g of AA, 48.7 g of diethylene glycol monobutyl ether and 0.022 g of TIPT as a catalyst were charged in a 500 ml four-necked flask, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B'-1) was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B'-1) was a pale yellow liquid at room temperature, had an acid value of 0.25, a hydroxyl value of 13, and had a number average molecular weight of 870.

Comparative synthesis example 2
73.7 g of EG, 200.3 g of AA, 103.8 g of diethylene glycol monobutyl ether and 0.023 g of TIPT as a catalyst were charged in a 500 ml four-necked flask, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B'-2) was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B'-2) was a pale yellow liquid at room temperature, had an acid value of 0.58, a hydroxyl value of 4, and had a number average molecular weight of 1410.

Comparative synthesis example 3
In a 500 ml four-necked flask, 121.7 g of EG, 227.7 g of SuA, 51.9 g of diethylene glycol monobutyl ether and 0.024 g of TIPT as a catalyst were charged, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B'-3) was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B'-3) was a pale yellow liquid at room temperature, had an acid value of 0.08, a hydroxyl value of 28, and had a number average molecular weight of 660.

Comparative synthesis example 4
113.4 g of EG, 66.4 g of PEG200, 216.5 g of SuA and 0.024 g of TIPT as a catalyst were charged in a 500 ml four-necked flask, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B-4) was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B'-4) was a pale yellow liquid at room temperature, had an acid value of 0.1, a hydroxyl value of 32, and had a number average molecular weight of 1600.

Comparative synthesis example 5
A 500 ml four-necked flask was charged with 129.0 g of EG, 47.3 g of PEG200, 238.0 g of SuA and 0.025 g of TIPT as a catalyst, and the temperature was gradually raised to 230 ° C. under a nitrogen stream from a nitrogen introduction tube. The condensation reaction was carried out at 230 ° C. for 8 hours, and it was confirmed that the acid value was 1.0 or less. The ester compound (B'-5) was obtained by removing excess glycol at 200 ° C. under reduced pressure. The obtained ester compound (B'-5) was a pale yellow liquid at room temperature, had an acid value of 0.05, a hydroxyl value of 32, and had a number average molecular weight of 1370.

<Adjustment of cellulose ester optical film>
100 parts of triacetyl cellulose resin (“LT-35” manufactured by Daicel Co., Ltd., abbreviated as TAC) or diacetyl cellulose resin (“L-50” manufactured by Daicel Co., Ltd., abbreviated as DAC), 10 to 30 parts of an ester compound. , 810 parts of methylene chloride and 90 parts of methanol were added to and dissolved in a mixed solvent to prepare a dope solution. This doping solution was cast on a glass plate to a thickness of 0.8 mm, dried at room temperature for 16 hours, and then dried at 50 ° C. for 30 minutes and then at 120 ° C. for 30 minutes to obtain a film. rice field. The obtained film was evaluated as follows, and the results are shown in the table.

<Tensile test of film obtained from cellulose ester resin composition>
Equipment: Autograph AG-IS manufactured by Shimadzu Corporation
Specimen: 150 mm x 10 mm, strip type with a thickness of 80 μm Chuck spacing: 100 mm
Test speed: 10 mm / min
The smaller the elastic modulus, the softer the film and the better the processability. The larger the elongation, the softer the film and the better the processability.

<Measurement of moisture permeability of film>
Measurements were made according to the method described in JIS Z 0208. The measurement conditions were a temperature of 40 ° C. and a relative humidity of 90%. The converted value when the film thickness is 60 μm is shown. The larger the obtained value, the better the moisture permeability.

<Moist heat test>
A film having a film thickness of 60 μm was exposed to an environment of 85 ° C. and a relative humidity of 90% (wet and heat environment) for 120 hours.

<HAZE>
The HAZE value was measured according to JIS K 7105 using a turbidity meter (“NDH 5000” manufactured by Nippon Denshoku Industries Co., Ltd.). The closer the obtained value is to 0%, the more transparent it is. A film having a film thickness of 60 μm was used.

In Comparative Example 5, the film was not evaluated because the additive bleeded out.

Claims (6)

A cellulose ester resin composition containing a cellulose ester resin (A) and an ester compound (B).
The ester compound (B) is
A dihydric alcohol (b1), a dibasic acid (b2), and a polyalkylene glycol monoalkyl ether having a number average molecular weight of 150 to 5000 (however, the terminal alkyl group has 1 to 6 carbon atoms) (b3). ), The cellulose ester resin composition, which is represented by the following general formula (1).

(During the ceremony,
G is an alkylene glycol residue or an oxyalkylene glycol residue,
A is an alkylene dicarboxylic acid residue or an aryl dicarboxylic acid residue independently, respectively.
R ¹ is an independently alkyl group having 1 to 6 carbon atoms.
R ² is an independently alkyl group having 1 to 6 carbon atoms.
m and n represent the number of repeating each average of m is Ri 4-50 der, the average of n is 2 to 20.
Each iteration, A, G, R ¹ may be the same or different. ) In the general formula (1), G is an alkylene glycol residue having 2 to 6 carbon atoms, and A is an alkylene dicarboxylic acid residue having 2 to 6 carbon atoms or an aryldicarboxylic acid residue having 6 to 8 carbon atoms. a group, R ¹ is a alkyl group having a carbon number of 2-3, a cellulose ester resin composition according to claim 1, wherein R ² is an alkyl group having 1 to 4 carbon atoms. The cellulose ester resin composition according to claim 1 or 2 , wherein the content of the ester compound (B) is 5 to 50 parts by mass with respect to 100 parts by mass of the cellulose ester resin (A). A molded product containing the cellulose ester resin composition according to any one of claims 1 to 3. The molded product according to claim 4 , which has a moisture permeability of 550 m ² / g for 24 hours or more at a thickness of 60 μm. The molded product according to claim 4 or 5, wherein the tensile elongation is 12% or more and the tensile elastic modulus is 4000 MPa or less.