Plasticizer composition for cellulose ester resin, cellulose ester resin composition, and molded product thereof

Abstract

To provide a plasticizer composition for cellulose ester resins having enhanced hydrolysis resistance.SOLUTION: A plasticizer composition for cellulose ester resins includes an alkoxy ether diester compound represented by formula (A) and a benzoic acid ester compound represented by formula (B).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a plasticizer composition for cellulose ester resins, a cellulose ester resin composition, and a molded article thereof.

Background Art

[0002] General-purpose plastics such as vinyl chloride resin (PVC) are used in a wide range of applications, and such general-purpose plastics are generally used after adding a plasticizer to make them flexible. However, since general-purpose plastics are difficult to decompose, there has been a movement to switch from general-purpose plastics to biodegradable resins from the perspective of emphasizing "sustainability" in recent years.

[0003] Since biodegradable resins are generally more polar than general-purpose plastics, a plasticizer suitable for biodegradable resins, which is different from conventional plasticizers for general-purpose plastics, is required. Among biodegradable resins, cellulose ester resins have attracted attention for their utilization as bio-derived sustainable materials, and alkoxy ether diesters are known as plasticizers for such cellulose ester resins (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The above alkoxy ether diester has high performance as a plasticizer for cellulose ester resins, but the alkoxy ether diester has a property of being easily hydrolyzed. In a cellulose ester resin composition containing an alkoxy ether diester as a plasticizer, the acid generated by the hydrolysis of the alkoxy ether diester causes the cellulose ester resin to also be hydrolyzed, resulting in problems such as deterioration of the dimensional stability and durability of the obtained molded article.

[0006] The problem to be solved by the present invention is to provide a plasticizer composition for cellulose ester resins with improved hydrolysis resistance. Another problem to be solved by the present invention is to provide a molded article excellent in dimensional stability and durability.

Means for Solving the Problems

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that the hydrolysis resistance of the plasticizer can be improved by further using a benzoic acid ester compound in the alkoxy ether diester, and have completed the present invention.

[0008] That is, the present invention relates to a plasticizer composition for cellulose ester resins and the like. 1. A plasticizer composition for cellulose ester resins containing an alkoxy ether diester compound represented by the following general formula (A) and a benzoic acid ester compound represented by the following general formula (B).

Chemical formula

Chemical formula

[0009] According to the present invention, a plasticizer composition for a cellulose ester resin with improved hydrolysis resistance can be provided. According to the present invention, a molded article excellent in dimensional stability and durability can be provided. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within a range that does not impair the effects of the present invention. In addition, the compounds in this specification may be derived from fossil resources or may be derived from biological resources.

[0011] [Plasticizer Composition for Cellulose Ester Resin] The plasticizer composition for cellulose ester resin of the present invention (hereinafter, may be simply referred to as "the plasticizer composition of the present invention") contains an alkoxy ether diester compound represented by the following general formula (A) and a benzoate compound represented by the following general formula (B). Hereinafter, each component of the plasticizer composition of the present invention will be described.

[0012]

Chemical formula

[0013] (Alkoxy ether diester compound) The alkoxy ether diester compound represented by the following general formula (A) is a compound obtained, for example, by reacting an aliphatic dibasic acid with an alkyl alcohol having an ether bond.

[0014]

Chemical formula

[0015] L 1 The alkylene group having 1 to 18 carbon atoms of may be linear or branched. Also, L 1 The alkylene group having 1 to 18 carbon atoms of may contain an alicyclic structure.

[0016] L 1 Specific examples of the alkylene group having 1 to 18 carbon atoms of include a malonic acid residue, a succinic acid residue, a glutaric acid residue, an adipic acid residue, a pimelic acid residue, a suberic acid residue, an azelaic acid residue, a sebacic acid residue, a dodecanedicarboxylic acid residue, a maleic acid residue, a fumaric acid residue, a 1,2-dicarboxycyclohexane residue, a 1,2-dicarboxycyclohexene residue, etc., preferably a succinic acid residue, a glutaric acid residue, an adipic acid residue or a sebacic acid residue, more preferably a succinic acid residue or an adipic acid residue. In the present invention, the "carboxylic acid residue" means the remaining organic group obtained by removing the carboxyl group from the carboxylic acid. Regarding the number of carbon atoms of the carboxylic acid residue, the carbon atom in the carboxyl group is not included.

[0017] R 11 and R 12 The alkyl group having an ether bond with 2 to 24 carbon atoms of may be linear or branched. Also, R 11 and R 12 The alkyl group having an ether bond with 2 to 24 carbon atoms of may contain an alicyclic structure.

[0018] R 11 and R 12Specific examples of the alkyl group having an ether bond with 2 to 24 carbon atoms include alcohol residues of polyalkylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, and tetraethylene glycol monoethyl ether. Among these, the alcohol residue of diethylene glycol monomethyl ether or the alcohol residue of triethylene glycol monomethyl ether is preferable. In the present invention, the "alcohol residue" refers to the remaining organic group obtained by removing the hydroxyl group from an alcohol.

[0019] The alkoxy ether diester compound represented by the general formula (A) is preferably an alkoxy ether diester compound represented by the following general formula (A1).

[0020] [Chemical formula] (In the general formula (A1), L 1 is an alkylene group having 1 to 18 carbon atoms, n is an integer in the range of 1 to 4, preferably an integer in the range of 2 to 3, m is an integer in the range of 2 to 4, preferably an integer in the range of 2 to 3, p is an integer in the range of 1 to 4, preferably an integer in the range of 2 to 3, q is an integer in the range of 2 to 4, preferably an integer in the range of 2 to 3, R 13 and R 14 are each independently an alkyl group having 1 to 6 carbon atoms. Note that m number of n's may be the same as or different from each other. q number of p's may be the same as or different from each other.)

[0021] R 13 and R 14The alkyl group having 1 to 6 carbon atoms is preferably an alkyl group having 1 or 2 carbon atoms, more preferably a methyl group.

[0022] The alkoxy ether diester compound represented by the general formula (A) in the plasticizer composition of the present invention may be used alone or in combination of two or more.

[0023] As described above, the alkoxy ether diester compound is a compound obtained by reacting, for example, an aliphatic dibasic acid with an alkyl alcohol having an ether bond, and can be produced by a known method.

[0024] (Benzoic acid ester compound) The benzoic acid ester compound represented by the following general formula (B) is a compound obtained by reacting, for example, an aliphatic diol or aliphatic triol with a benzoic acid derivative and an arbitrary aliphatic monocarboxylic acid. By containing the benzoic acid ester, the influence of water on the alkoxy ether diester can be reduced, and the drawbacks of the alkoxy ether diester that is easily hydrolyzed can be complemented.

[0025] [Chemical formula] (In the general formula (B), R 21 is an alkyl group having 1 to 6 carbon atoms, L 2 is a divalent aliphatic group or a trivalent aliphatic group, R 22 is an alkyl group having 1 to 20 carbon atoms, or an alkyl group having an ether bond with 2 to 20 carbon atoms, s is an integer from 1 to 3, t is an integer in the range of 0 to 2, u is an integer in the range of 0 to 2, and the sum of s, t, and u is L 2 is an integer corresponding to the valence of the aliphatic group of, x is an integer in the range of 0 to 5.)

[0026] In the general formula (B), L 2 When it is a divalent aliphatic group, s + t + u = 2, and L 2 When it is a trivalent aliphatic group, s + t + u = 3.

[0027] In the general formula (B), when there are a plurality of R 21 the plurality of R 21 may be the same as each other or different from each other. Similarly, in the general formula (B), when there are a plurality of R 22 the plurality of R 22 may be the same as each other or different from each other.

[0028] L 2 When L is a divalent aliphatic group, examples of the divalent aliphatic group include an alkylene group having 1 to 12 carbon atoms or an alkylene group having an ether bond with 1 to 12 carbon atoms.

[0029] L 2 Specific examples of the alkylene group having 1 to 12 carbon atoms of L include ethylene glycol residue, 1,2 - propylene glycol residue, 1,3 - propanediol residue, 1,2 - butanediol residue, 1,3 - butanediol residue, 2 - methyl - 1,3 - propanediol residue, 1,4 - butanediol residue, 1,5 - pentanediol residue, 2,2 - dimethyl - 1,3 - propanediol (neopentyl glycol) residue, 2,2 - diethyl - 1,3 - propanediol (3,3 - dimethylolpentane) residue, 2 - n - butyl - 2 - ethyl - 1,3 - propanediol (3,3 - dimethylolheptane) residue, 3 - methyl - 1,5 - pentanediol residue, 1,6 - hexanediol residue, 2,2,4 - trimethyl - 1,3 - pentanediol residue, 2 - ethyl - 1,3 - hexanediol residue, 2 - methyl - 1,8 - octanediol residue, 1,9 - nonanediol residue, 1,10 - decanediol residue, 1,12 - dodecanediol residue, and the like. In the present invention, the "alcohol residue" and the "glycol residue" refer to the remaining organic groups obtained by removing the hydroxyl group from alcohol and glycol.

[0030] L 2 The alkylene group having 1 to 12 carbon atoms in L may contain an alicyclic structure. Examples of the alkylene group having 1 to 12 carbon atoms containing the alicyclic structure include 1,3-cyclopentanediol residue, 1,2-cyclohexanediol residue, 1,3-cyclohexanediol residue, 1,4-cyclohexanediol residue, 1,2-cyclohexanedimethanol residue, 1,4-cyclohexanedimethanol residue, and the like.

[0031] L 2 The alkylene group having 1 to 12 carbon atoms in L is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms.

[0032] L 2 The alkylene group having an ether bond and having 1 to 12 carbon atoms in L is a group in which one or more -CH2- in the alkylene group are replaced by -O-.

[0033] L 2 The alkylene group having an ether bond and having 1 to 12 carbon atoms in L is preferably an alkylene group having an ether bond and having 1 to 10 carbon atoms, more preferably an alkylene group having an ether bond and having 1 to 8 carbon atoms.

[0034] L 2 Specific examples of the alkylene group having an ether bond and having 1 to 12 carbon atoms in L include diethylene glycol residue, triethylene glycol residue, tetraethylene glycol residue, dipropylene glycol residue, tripropylene glycol residue, and the like.

[0035] L 2 When L is a trivalent aliphatic group, examples of the trivalent aliphatic group include those in which one of the hydrogen atoms bonded to the carbon atoms of the above-mentioned alkylene group having 1 to 12 carbon atoms and the alkylene group having an ether bond and having 2 to 12 carbon atoms is replaced by a bond. Specific examples of the trivalent aliphatic group include trimethylolpropane residue, glycerin residue, and the like.

[0036] L 2 is preferably an ethylene glycol residue, 1,2 - propylene glycol residue, 1,3 - propanediol residue, 1,2 - butanediol residue, 1,3 - butanediol residue, 2 - methyl - 1,3 - propanediol residue, neopentyl glycol residue, diethylene glycol residue, dipropylene glycol residue, triethylene glycol residue, trimethylolpropane residue or glycerin residue, more preferably an ethylene glycol residue, diethylene glycol residue, 1,2 - propylene glycol residue, dipropylene glycol residue, trimethylolpropane residue or glycerin residue, and even more preferably an ethylene glycol residue, diethylene glycol residue, 1,2 - propylene glycol residue or dipropylene glycol residue.

[0037] X is preferably 0 or 1, and more preferably 0.

[0038] The benzoic acid ester compound represented by the general formula (B) is preferably a benzoic acid ester compound represented by the following general formula (B1).

[0039]

Chemical formula

[0040] The benzoic acid ester compound represented by the general formula (B) in the plasticizer composition of the present invention may be used alone or in combination of two or more.

[0041] As described above, the benzoic acid ester compound is a compound obtained, for example, by reacting an aliphatic diol or aliphatic triol with a benzoic acid derivative and an arbitrary aliphatic monocarboxylic acid, and can be produced by a known method.

[0042] The mass ratio of the alkoxy ether diester compound and the benzoic acid ester compound in the plasticizer composition of the present invention is, for example, in the range of alkoxy ether diester compound:benzoic acid ester compound = 90:10 to 20:80, preferably in the range of alkoxy ether diester compound:benzoic acid ester compound = 85:15 to 40:60, and more preferably in the range of alkoxy ether diester compound:benzoic acid ester compound = 80:20 to 50:50.

[0043] The plasticizer composition of the present invention only needs to contain the alkoxy ether diester compound and the benzoic acid ester compound, and may contain other plasticizer components as long as the effects of the present invention are not impaired. The plasticizer composition of the present invention preferably consists essentially of the alkoxy ether diester compound and the benzoic acid ester compound. Here, "consists essentially of" means that, for example, the total amount of the alkoxy ether diester compound and the benzoic acid ester compound is 90% by mass or more, 95% by mass or more, 98% by mass or more, or 100% by mass of the plasticizer composition of the present invention.

[0044] [Cellulose ester resin composition] The cellulose ester resin composition of the present invention contains the plasticizer composition of the present invention and a cellulose ester resin. Examples of the cellulose ester resin contained in the cellulose ester resin composition of the present invention include cellulose acetate (CA), cellulose diacetate (DAC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB), cellulose acetate phthalate, polycaprolactone grafted cellulose acetate, and the like. Among these, acetylated celluloses such as cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, and cellulose acetate butyrate are preferred because of their good transparency, processability, and mechanical properties (tensile strength, flexural strength, flexural modulus, etc.). Cellulose diacetate is most preferred. The cellulose ester resin can be used alone or in combination of two or more.

[0045] When the cellulose ester resin is acetylated cellulose, the upper limit of the degree of substitution of the acetyl group is preferably 3.0 or less, more preferably 2.7 or less, and even more preferably in the range of 2.6 or less. The lower limit of the degree of substitution is preferably 1.0 or more, preferably 1.5 or more, and even more preferably 2.0 or more. If the degree of polymerization and the degree of substitution of the cellulose acetate are within the above ranges, a film having excellent mechanical properties can be obtained. In the present invention, it is more preferable to use so-called cellulose diacetate.

[0046] The degree of polymerization of the cellulose ester is preferably in the range of 100 to 1,000, more preferably in the range of 100 to 500, in terms of the viscosity average degree of polymerization.

[0047] The above-mentioned "viscosity-average degree of polymerization" can be measured in accordance with the limiting viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, "Journal of the Fiber Society", Vol. 18, No. 1, pp. 105-120, 1962). Specifically, 0.2 g of absolutely dried cellulose ester is precisely weighed and dissolved in 100 ml of a mixed solvent of methylene chloride:ethanol = 9:1 (mass ratio). The dropping time of this solution is measured at a constant temperature of 25 °C in an Ostwald viscometer, and the average degree of polymerization is calculated by the following [Formula 1]. Average degree of polymerization = [η] / K m ··· [Formula 1] [η] = (lnη rel ) / C η rel = T / T0 K m = 6×10 -4 T: Dropping time of the measurement sample (seconds) T0: Dropping time of the solvent (seconds) C: Concentration of the sample (g / l)

[0048] As the cellulose ester resin, commercially available products may be used. Examples of such commercially available products include cellulose diacetates such as "L-20", "L-30", "L-40", "L-50", "L-70", etc. manufactured by Daicel Corporation; cellulose triacetates such as "LT-35", "LT-105", etc. manufactured by Daicel Corporation; cellulose acetate propionates such as "CAP482-20", "CAP141-20", etc. manufactured by Eastman Chemical; cellulose acetate butyrates such as "CAB381-20", "CAB171-15", etc.; and cellulose acetates such as "CA398-30", etc.

[0049] From the perspective of compatibility with the cellulose ester resin, etc., the content of the plasticizer composition in the cellulose ester resin composition of the present invention is preferably in the range of 1 to 100 parts by mass, more preferably in the range of 5 to 60 parts by mass, still more preferably in the range of 10 to 50 parts by mass, and even more preferably 20 to 45 parts by mass with respect to 100 parts by mass of the cellulose ester resin.

[0050] In the cellulose ester resin composition of the present invention, the total content of the cellulose ester resin and the plasticizer composition of the present invention is, for example, 80% by mass or more, 90% by mass or more, or 95% by mass or more of the solid content in the composition. The upper limit of the total content of the cellulose ester resin and the plasticizer for the cellulose ester resin of the present invention is not particularly limited, and is, for example, 100% by mass or less, 95% by mass or less, or 90% by mass or less.

[0051] The cellulose ester resin composition of the present invention may contain a cellulose ester resin and the plasticizer composition of the present invention, and may also contain other resins, plasticizers other than the plasticizer composition of the present invention (other plasticizers), other additives, and the like.

[0052] The other resins are not particularly limited, and examples thereof include polyolefin, polysulfide, polyvinyl chloride, modified polysulfide, silicone resin, modified silicone resin, acrylic urethane resin, epoxy resin, polyurethane, acrylic resin, polyester, unsaturated polyester, and the like.

[0053] Examples of the other plasticizers include phthalic acid esters such as dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), ditridecyl phthalate (DTDP); terephthalic acid esters such as dimethyl terephthalate, diethyl terephthalate (DETP), bis(2-ethylhexyl) terephthalate (DOTP); isophthalic acid esters such as dimethyl isophthalate (DMIP), diethyl isophthalate (DEIP), bis(2-ethylhexyl) isophthalate (DOIP); trimellitic acid esters such as tributyl trimellitate (TBTM), tri-2-ethylhexyl trimellitate (TOTM), trinormal octyl trimellitate (TnOTM); pyromellitic acid esters such as tetra-2-ethylhexyl pyromellitate (TOPM); aliphatic dibasic acid esters such as di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), di-2-ethylhexyl sebacate (DOS), diisononyl sebacate (DINS); phosphate esters such as tri-2-ethylhexyl phosphate (TOP), tricresyl phosphate (TCP); alkyl esters of polyhydric alcohols such as pentaerythritol; polyesters having a molecular weight of 800 to 4,000 synthesized by polyesterification of dibasic acids such as adipic acid and glycol; epoxidized esters such as epoxidized soybean oil, epoxidized linseed oil; alicyclic dibasic acids such as diisononyl hexahydrophthalate; fatty acid glycol esters such as 1,4-butanediol dicaprate; glycerin esters such as triacetin, diacetin; chlorinated paraffins obtained by chlorinating paraffin wax or n-paraffin; chlorinated fatty acid esters such as chlorinated stearic acid ester; and higher fatty acid esters such as butyl oleate, etc.

[0054] When using the other plasticizer in the cellulose ester resin composition of the present invention, the content of the other plasticizer is, for example, in the range of 0.1 to 100 parts by mass, preferably in the range of 1 to 50 parts by mass, based on 100 parts by mass of the plasticizer composition of the present invention.

[0055] Examples of the other additives include flame retardants, stabilizers, stabilization aids, colorants, processing aids, fillers, antioxidants (anti-aging agents), ultraviolet absorbers, light stabilizers, lubricants, antistatic agents, crosslinking aids, and the like.

[0056] [Method for producing cellulose ester resin composition] The method for producing the cellulose ester resin composition of the present invention is not particularly limited. For example, it can be obtained by a method of melt-kneading a cellulose ester resin, a plasticizer composition for the cellulose ester resin of the present invention, the above-mentioned other additives, etc. using a melt-kneading machine such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a Brabender, various kneaders, etc.

[0057] [Molded article of cellulose ester resin composition] The cellulose ester resin composition of the present invention can be molded by various molding methods applicable to general-purpose plastics. Examples of the above molding methods include compression molding (compression molding, lamination molding, stampable molding), injection molding, extrusion molding and co-extrusion molding (film molding by inflation method or T-die method, lamination molding, pipe molding, wire / cable molding, molding of profiled materials), 3D printing, hot press molding, hollow molding (various blow molding), calender molding, solid molding (uniaxial stretching molding, biaxial stretching molding, roll rolling molding, stretch-oriented nonwoven fabric molding, thermoforming (vacuum forming, pressure-air forming), plastic processing, powder molding (rotational molding), various nonwoven fabric molding (dry method, adhesion method, entanglement method, spunbond method, etc.). Injection molding, extrusion molding, 3D printing, compression molding or hot press molding is preferably applied. As specific shapes, application to sheets, films, and containers is preferred.

[0058] The molded article obtained above may be subjected to secondary processing. Examples of the secondary processing include embossing, painting, adhesion, printing, metallizing (such as plating), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.).

[0059] Since the molded article obtained from the cellulose ester resin composition of the present invention is composed of a cellulose ester resin and is decomposable, it is a molded article with a small environmental load.

[0060] The molded article obtained from the cellulose ester resin composition of the present invention is suitably used for a wide range of applications such as packaging materials for packaging liquids, powder granules, and solids, agricultural materials, and building materials. Specific uses include injection molded articles (for example, trays for fresh food, containers for fast food, containers for coffee capsules, cutlery, outdoor leisure products, etc.), extrusion molded articles (for example, films, sheets, fishing lines, fishing nets, vegetation nets, sheets for secondary processing, water retention sheets, etc.), hollow molded articles (bottles, etc.), and shaping by 3D printing.

[0061] The uses are not limited to the above, and it can also be used for mending tapes, glasses frames, aglets, agricultural films, coating materials, coating materials for fertilizers, seedling pots, laminated films, plates, stretched sheets, monofilaments, non-woven fabrics, flat yarns, staples, crimped fibers, ribbed tapes, split yarns, composite fibers, blow bottles, shopping bags, garbage bags, compost bags, fishing lines, cutlery, cosmetic containers, detergent containers, bleach containers, ropes, binding materials, sanitary cover stock materials, cool boxes, cushion material films, multifilaments, synthetic paper, surgical threads, sutures, artificial bones, artificial skin, microcapsules, wound dressing materials, etc. for medical use.

Examples

[0062] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Note that the present invention is not limited to the following Examples.

[0063] In the examples of the present application, the values of acid value and hydroxyl value are the values evaluated by the following methods. [Method for Measuring Acid Value] Measured by the method according to JIS K0070-1992. [Method for Measuring Hydroxyl Value] Measured by the method according to JIS K0070-1992.

[0064] In the examples of the present application, the number average molecular weight of the polyester is the value converted to polystyrene based on GPC measurement, and the measurement conditions 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 rate: 0.35 mL / min Measurement sample: A solution obtained by dissolving 7.5 mg of the sample in 10 ml of tetrahydrofuran and filtering the resulting solution with a microfilter was used as the measurement sample. Sample injection volume: 20 μl Standard sample: The following monodisperse polystyrene with a known molecular weight was used in accordance with the measurement manual of the "HLC-8320GPC".

[0065] (Monodisperse Polystyrene) "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

[0066] (Synthesis Example 1: Synthesis of alkoxy ether diester (A1)) A 1-liter four-necked flask was charged with 234 g of adipic acid, 461 g of 2-(2-methoxyethoxy)ethanol, and 0.04 g of tetraisopropyl titanate (hereinafter abbreviated as "TiPT") as a catalyst, and the temperature was raised to 210°C and reacted for 14 hours. After the reaction, unreacted glycol was distilled off under reduced pressure at 200°C. After the outflow of unreacted glycol ceased, the reduced pressure was released and the temperature was lowered, and the reaction product was filtered out to obtain a transparent yellow liquid alkoxy ether diester (A1).

[0067] The number average molecular weight of the obtained alkoxy ether diester (A1) was 390, the acid value was 1.0, and the hydroxyl value was 0.5.

[0068] (Synthesis Example 2: Synthesis of alkoxy ether diester (A2)) A 1-liter four-necked flask was charged with 159 g of succinic acid, 497 g of 2-(2-(2-methoxyethoxy)ethoxy)ethanol, and 0.02 g of TiPT as a catalyst, and then the temperature was raised to 220°C and reacted for 17 hours. After the reaction, unreacted glycol was distilled off under reduced pressure at 200°C. After the outflow of unreacted glycol ceased, the reduced pressure was released and the temperature was lowered, and the reaction product was filtered out to obtain a transparent yellow liquid alkoxy ether diester (A2).

[0069] The number average molecular weight of the obtained alkoxy ether diester (A2) was 430, the acid value was 0.6, and the hydroxyl value was 1.3.

[0070] (Synthesis Example 3: Synthesis of benzoic acid diester (B1)) Into a 2-liter four-necked flask, 979 g of benzoic acid (hereinafter abbreviated as "BzA"), 159 g of propylene glycol (hereinafter abbreviated as "PG"), 289 g of diethylene glycol, and 0.43 g of TiPT as a catalyst were charged. Then, the temperature was raised to 230°C and reacted for 11 hours. After the reaction, unreacted glycol was distilled off under reduced pressure at 230°C. After the outflow of unreacted glycol ceased, the reduced pressure was released and the temperature was lowered, and the reaction product was filtered and taken out to obtain a transparent yellow liquid benzoic acid diester (B1).

[0071] The number average molecular weight of the obtained benzoic acid diester (B1) was 310, the acid value was 0.1, and the hydroxyl value was 4.

[0072] (Synthesis Example 4: Synthesis of benzoic acid diester (B2)) Into a 2-liter four-necked flask, 772 g of BzA, 229 g of diethylene glycol, 177 g of dipyrropylene glycol, and 0.35 g of TiPT as a catalyst were charged. Then, the temperature was raised to 240°C and reacted for 11 hours. After the reaction, unreacted glycol was distilled off under reduced pressure at 210°C. After the outflow of unreacted glycol ceased, the reduced pressure was released and the temperature was lowered, and the reaction product was filtered and taken out to obtain a transparent yellow liquid benzoic acid diester (B2).

[0073] The number average molecular weight of the obtained benzoic acid diester (B2) was 370, the acid value was 0.1, and the hydroxyl value was 5.

[0074] (Synthesis Example 5: Synthesis of benzoic acid triester (B3)) A 3-liter four-necked flask was charged with 1832 g of BzA, 461 g of glycerin, and 0.069 g of TiPT as a catalyst, and then the temperature was raised to 220 °C and reacted for 20 hours. After the reaction, unreacted glycerin was distilled off under reduced pressure at 220 °C. After the outflow of unreacted glycerin ceased, the reduced pressure was released and the temperature was lowered, and the reaction product was filtered out to obtain a transparent yellow liquid benzoic acid triester (B3).

[0075] The number average molecular weight of the obtained benzoic acid triester (B3) was 410, the acid value was 0.3, and the hydroxyl value was 27.

[0076] (Example 1: Production and Evaluation of Cellulose Ester Optical Film) 70 parts by mass of cellulose acetate resin (degree of acetylation 2.36, degree of esterification 54.2%), 30 parts by mass of a plasticizer composition (a mixture of diester (A1) and diester (B2) with a mass ratio of diester (A1): diester (B2) = 8:2), and IRGANOX-1010 as a stabilizer was blended in an amount of 0.1 mass percent based on the cellulose acetate resin and stirred and mixed at 70 °C to prepare a cellulose acetate resin composition. The obtained composition was kneaded using a small-scale melt-kneading apparatus (Laboplastmill), and a press plate with a thickness of 3 mm and a size of 60 mm square was manufactured using a hot press machine. The following evaluations were performed on the manufactured press plate. The results are shown in Table 1.

[0077] (1) Transparency The surface of the press plate was visually inspected, and the transparency of the press plate was evaluated according to the following criteria. No turbidity or foreign matter can be confirmed on the surface of the press plate: ○ Turbidity and / or foreign matter can be confirmed on the surface of the press plate: ×

[0078] (2) Compatibility after the Damp Heat Test The press plate was exposed to an environment of 85 °C and a relative humidity of 90% (damp heat environment) for 6 hours, and the state of the press plate after the damp heat test was visually inspected, and the compatibility of the plasticizer was evaluated according to the following criteria. No foreign matter bleed - out can be confirmed on the surface of the press plate: ○ Foreign matter bleed - out can be confirmed on the surface of the press plate: ×

[0079] (3) Water absorbency While exposing the press plate to an environment of 85 °C and 90% relative humidity (humid - heat environment) for 24 hours, the mass of the press plate was measured at 6 hours after the start of the test and 24 hours after the start of the test (at the end of the test) respectively. Calculate (the mass of the press plate after 24 hours - the mass of the press plate after 6 hours) / the mass of the press plate after 6 hours of the humid - heat test to evaluate the increase rate of the press plate during the humid - heat test. The smaller this value is, the less likely it is for the press plate to deform due to moisture absorption, so it is preferable.

[0080] Regarding the cellulose acetate resin composition used in the production of the press plate, the following evaluations were separately carried out. The results are shown in Table 1.

[0081] (4) Acetic acid generation amount Put 1.000 g of the composition used in the production of the press plate into a 25 - ml sample bottle. After leaving it under the conditions of 85 °C × 90% humidity without covering the lid of the sample bottle for 1 day, cover the lid and leave it for another 168 hours, and then examine the amount of acetic acid generated with a detector tube (Kitagawa - type gas detector tube for acetic acid). The less the acetic acid generation amount is, the less likely the plasticizer in the composition is to hydrolyze, and the durability reduction of the obtained molded product can be suppressed.

[0082] (Examples 2 - 4 and Comparative Examples 1 - 5: Production and evaluation of cellulose ester optical films) Except for changing the plasticizer to those shown in Table 1, the preparation of the cellulose acetate resin composition and the production of the press plate were carried out in the same manner as in Example 1, and the same evaluations as in Example 1 were performed. The results are shown in Table 1.

[0083]

Table 1

[0084] Regarding Table 1, from the results of the amount of acetic acid generated in Example 1 and Comparative Example 1, and Example 2-4 and Comparative Example 2, it can be seen that by using a combination of a benzoate compound with an alkoxy ether diester, the hydrolysis of the alkoxy ether diester can be suppressed.

Claims

1. A plasticizer composition for a cellulose ester resin, containing an alkoxy ether diester compound represented by the following general formula (A) and a benzoic acid ester compound represented by the following general formula (B). 【Chemical 1】 (In the above general formulas (A) and (B), L １ is an alkylene group having 1 to 18 carbon atoms, R １１ and R １２ are each independently an alkyl group having an ether bond with 2 to 24 carbon atoms, R ２１ is an alkyl group having 1 to 6 carbon atoms, L ２ is a divalent aliphatic group or a trivalent aliphatic group, R ２２ is an alkyl group having 1 to 20 carbon atoms or an alkyl group having an ether bond and 2 to 20 carbon atoms, s is an integer in the range of 1 to 3, t is an integer in the range of 0 to 2, u is an integer in the range of 0 to 2, and the sum of s, t, and u is L ２ which is an integer corresponding to the valence of the aliphatic group of x is an integer in the range of 0 to 5.)

2. The plasticizer composition for a cellulose ester resin according to Claim 1, wherein the mass ratio of the alkoxy ether diester compound and the benzoic acid ester compound satisfies alkoxy ether diester compound:benzoic acid ester compound = 85:15 to 40:

60.

3. The plasticizer composition for a cellulose ester resin according to Claim 1 or 2, wherein the alkoxy ether diester compound is an alkoxy ether diester compound represented by the following general formula (A1). 【Chemical 2】 (In the above general formula (A1), L １ is an alkylene group having 1 to 18 carbon atoms, n is an integer in the range of 1 to 4, m is an integer in the range of 2 to 4, p is an integer in the range of 1 to 4, q is an integer in the range of 2 to 4, R １３ and R １４ is each independently an alkyl group having 1 to 6 carbon atoms. In addition, m number of n's may be the same as or different from each other. q number of p's may be the same as or different from each other.)

4. Said L １ is a malonic acid residue, a succinic acid residue, a glutaric acid residue, an adipic acid residue, a pimelic acid residue, a suberic acid residue, an azelaic acid residue, a sebacic acid residue, a dodecanedicarboxylic acid residue, a maleic acid residue, a fumaric acid residue, a 1,2-dicarboxycyclohexane residue or a 1,2-dicarboxycyclohexene residue, and the plasticizer composition for a cellulose ester resin according to claim 1 or 2.

5. Said R １１ and R １２ are each independently an alcohol residue of a polyalkylene glycol monoalkyl ether selected from diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, and tetraethylene glycol monoethyl ether. The plasticizer composition for a cellulose ester resin according to claim 1 or 2.

6. The plasticizer composition for a cellulose ester resin according to Claim 1 or 2, wherein the benzoic acid ester compound is a benzoic acid ester compound represented by the following general formula (B1). 【Chemical Formula 3】 (In the above general formula (B1), L ２ is a divalent aliphatic group or a trivalent aliphatic group, v is L ２ an integer corresponding to the valence of the aliphatic group of R ２１ is an alkyl group having 1 to 6 carbon atoms, x is an integer in the range of 0 to 5.)

7. Said L ２ is the plasticizer composition for cellulose ester resin according to claim 1 or 2, which is an ethylene glycol residue, 1,2-propylene glycol residue, 1,3-propanediol residue, 1,2-butanediol residue, 1,3-butanediol residue, 2-methyl-1,3-propanediol residue, neopentyl glycol residue, diethylene glycol residue, dipropylene glycol residue, triethylene glycol residue, tripropylene glycol residue, trimethylolpropane residue or glycerin residue.

8. A cellulose ester resin composition containing the plasticizer composition for a cellulose ester resin according to Claim 1 or 2 and a cellulose ester resin, wherein the plasticizer composition for a cellulose ester resin is contained in a range of 1 to 100 parts by mass with respect to 100 parts by mass of the cellulose ester resin.

9. A molded article of the cellulose ester resin composition according to Claim 8.

10. The molded article according to Claim 9, which is an eyeglass frame.

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