Acid scavenger for cellulose ester resin, cellulose ester resin composition and compact thereof

Abstract

To provide an acid scavenger capable of yielding a compact of a cellulose ester resin composition that is transparent, free from coloration and bleed-out, and has a reduced odor derived from fatty acids, and a cellulose ester resin composition that is transparent, free from coloration and bleed-out, and has a reduced odor derived from fatty acids.SOLUTION: The present invention provides an acid scavenger for cellulose ester resins that includes a (meth)acrylate ester copolymer (A) with glycidyl (meth)acrylate as an essential constitutional monomer, where the epoxy equivalent of the (meth)acrylate ester copolymer (A) is between 140 g / eq and 750 g / eq, and the glass transition temperature of the (meth)acrylate ester copolymer (A) is between 50°C and 130°C.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an acid scavenger for a cellulose ester resin, a cellulose ester resin composition, and a molded article thereof. [Background technology]

[0002] Cellulose derivative (e.g., fatty acid cellulose ester) materials lack thermal stability as they are, and not only do they discolor when heated during injection molding, but they also suffer from problems such as the liberation of fatty acids and the odor caused by the liberated fatty acids. Patent Document 1 proposes a method of adding an inorganic deodorant as a method for solving the odor problem, but this has the problem of losing transparency of the inorganic deodorant resin.

[0003] As another method, a method has been proposed in which organic deodorants such as epoxy compounds (Patent Document 2) and carbodiimide compounds (Patent Document 3) are chemically reacted with lower fatty acids in the resin to deodorize the resin. However, this method has problems such as the organic deodorant bleeding out onto the resin surface, making the surface sticky. Furthermore, the carbodiimide compound has the problem of losing the transparency of the resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-028429 A [Patent Document 2] Patent No. 2533764 [Patent Document 3] Patent No. 6691395 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned problems of the conventional technology, and an object of the present invention is to provide an acid scavenger which can give a molded article of a cellulose ester resin composition which is free from coloration or bleed-out, has transparency, and has little odor derived from fatty acids, and a cellulose ester resin composition which is free from coloration or bleed-out, has transparency, and has little odor derived from fatty acids. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above problems, and have arrived at the present invention. That is, the present invention relates to an acid scavenger for cellulose ester resins, comprising a (meth)acrylic acid ester copolymer (A) containing glycidyl (meth)acrylate as an essential constituent monomer, the (meth)acrylic acid ester copolymer (A) having an epoxy equivalent of 140 g / eq or more and 750 g / eq or less, and the (meth)acrylic acid ester copolymer (A) having a glass transition temperature of 50° C. or more and 130° C. or less; a cellulose ester resin composition comprising a cellulose ester resin and a (meth)acrylic acid ester copolymer (A), the (meth)acrylic acid ester copolymer (A) being an acid scavenger for cellulose ester resins ... A cellulose ester resin composition, in which the (meth)acrylic ester copolymer (A) is a polymer containing glycidyl (meth)acrylate as an essential constituent monomer, the (meth)acrylic ester copolymer (A) has an epoxy equivalent of 140 g / eq or more and 750 g / eq or less, the (meth)acrylic ester copolymer (A) has a glass transition temperature of 50°C or more and 130°C or less, and the weight ratio of the (meth)acrylic ester is 0.3 to 15 wt % based on the total weight of the cellulose ester resin composition; and a molded article of the cellulose ester resin composition. Effect of the Invention

[0007] The acid scavenger of the present invention has excellent ability to capture fatty acids liberated from cellulose ester resins, and further has excellent dispersibility in cellulose ester resins, so that it is possible to provide a cellulose ester resin composition free from coloration or bleed-out, transparent, and with little odor derived from fatty acids, and a molded article thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <Acid scavengers for cellulose ester resins> The acid scavenger for cellulose ester resin of the present invention contains a (meth)acrylic acid ester copolymer (A). In this specification, "(meth)acrylic acid" is used to mean "methacrylic acid and / or acrylic acid".

[0009] When cellulose ester resin, which is a reaction product of cellulose and an organic acid anhydride, is heated and melted during molding, the ester group of the cellulose ester resin may decompose, liberating an organic acid. The acid scavenger for cellulose ester resin of the present invention has a function of capturing an organic acid liberated from the cellulose ester resin upon heating, etc. The organic acid captured by the acid scavenger for cellulose ester resin of the present invention is an organic acid (hereinafter also referred to as a fatty acid in this application) that is a constituent material of the ester group contained in the cellulose ester resin, and examples of such include acetic acid, butyric acid, and propionic acid.

[0010] <(Meth)acrylic acid ester copolymer (A)> The (meth)acrylic acid ester copolymer (A) contained in the acid scavenger for cellulose ester resin of the present invention has glycidyl (meth)acrylate as an essential constituent monomer. In the present invention, the glycidyl group of glycidyl (meth)acrylate reacts with fatty acid liberated during molding of cellulose ester resin to capture the fatty acid, thereby reducing odor derived from the fatty acid. Examples of glycidyl (meth)acrylate include glycidyl acrylate and glycidyl methacrylate, and glycidyl methacrylate is preferred from the viewpoint of suppressing bleed-out from cellulose ester resin.

[0011] The (meth)acrylic acid ester copolymer (A) of the present invention may contain other vinyl compounds (a2) as monomers.

[0012] The other vinyl compounds (a2) are not particularly limited, and known vinyl compounds (disclosed in JP-A-2002-284881, WO 99 / 40132, JP-A-10-251315, Chemistry of Polymer Synthesis (by Takayuki Otsu, published on January 10, 1979 by Kagaku Dojin Co., Ltd.), etc.) can be used. Examples of the monomer include styrene-based compounds (styrene, p-vinyltoluene, etc.), acrylic acid, acrylic acid esters (t-butyl acrylate, ethyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, butyl acrylate, etc.), methacrylic acid, methacrylic acid esters (2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, benzyl methacrylate, methyl methacrylate, trifluoroethyl methacrylate, dimethylaminoethyl methacrylate, butyl methacrylate, etc.), maleic acid and its derivatives (maleic acid, maleic anhydride, dimethyl maleate, diethyl maleate, methyl maleate, maleimide, phenylmaleimide, etc.), fumaric acid and its derivatives (fumaric acid, ethyl fumarate, etc.), N-vinylpyrrolidone, and N-vinylimidazole.

[0013] Among these, at least one selected from the group consisting of methyl methacrylate, 2-hydroxyethyl methacrylate, and 2-methoxyethyl (meth)acrylate is particularly preferred.

[0014] The (meth)acrylic acid ester copolymer (A) of the present invention has an epoxy equivalent of 140 g / eq or more and 750 g / eq or less, and preferably 140 g / eq or more and 450 g / eq or less from the viewpoint of acid scavenging ability. If the epoxy equivalent is less than 140 g / eq, the dispersibility of the (meth)acrylic acid ester copolymer (A) in the cellulose ester resin becomes poor, and the fatty acid liberated from the cellulose ester resin cannot be efficiently captured. If the epoxy equivalent is more than 750 g / eq, the number of glycidyl groups possessed by the acid scavenger of the present invention becomes small, and the fatty acid liberated from the cellulose ester resin cannot be completely captured, and the odor cannot be reduced. The epoxy equivalent in the present invention is a value measured by a method specified in JIS K7236:2001.

[0015] The (meth)acrylic acid ester copolymer (A) of the present invention has a glass transition temperature of 50° C. or more and 130° C. or less, and from the viewpoints of bleed-out and solubility in cellulose ester resin, it is preferably 50° C. or more and 100° C. or less. If the glass transition temperature is lower than 50° C., it will bleed out from the cellulose ester resin, and if the glass transition temperature is higher than 130° C., it will be poorly dispersible in the cellulose ester resin.

[0016] The (meth)acrylic acid ester copolymer (A) of the present invention can be obtained by carrying out solution polymerization by a known method using glycidyl (meth)acrylate, which is an essential constituent monomer, and other vinyl compounds (a2) used as necessary. For example, it can be obtained by dropping a solution of a monomer composition obtained by dissolving glycidyl (meth)acrylate and other vinyl compounds (a2) as necessary in a solvent and a polymerization initiator solution into a glass reaction vessel containing a solvent in a reflux state, and polymerizing the resulting solution.

[0017] The ratio of the amount of glycidyl (meth)acrylate, which is an essential constituent monomer, to the amount of other vinyl compounds (a2) used as necessary may be selected so as to satisfy the above-mentioned epoxy equivalent and glass transition temperature. When other vinyl compounds (a2) are used, methyl methacrylate, 2-hydroxyethyl methacrylate, and 2-methoxyethyl (meth)acrylate are preferred from the viewpoint of compatibility and dispersibility in cellulose ester, and methyl methacrylate is more preferred.

[0018] When the (meth)acrylic acid ester copolymer (A) uses another vinyl compound (a2) as a constituent monomer, the amount of the vinyl compound (a2) is preferably 0.1 to 80% by weight, more preferably 5 to 50% by weight, based on the total weight of glycidyl (meth)acrylate and the vinyl compound (a2), from the viewpoint of acid scavenging ability.

[0019] The weight average molecular weight of the (meth)acrylic acid ester copolymer (A) is preferably from 3,000 to 100,000, more preferably from 5,000 to 50,000, from the viewpoint of dispersibility in the cellulose ester resin.

[0020] The weight average molecular weight and the molecular weight distribution (Mw / Mn) are measured by dissolving the copolymer (A) in tetrahydrofuran (THF) as a sample solution and using gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh Corporation HLC-8120 Column: 2 TSK GEL GMH6 (Tosoh Corporation) Measurement temperature: 40℃ Sample solution: 0.25% by weight in THF solution Solution injection volume: 100μL Detector: Refractive index detector Reference material: Tosoh standard polystyrene [TSKstandard POLYSTYRENE] 12 points (molecular weight: 500,1050,2800,5970,9100,18100,37900,96400,190000,355000,1090000,2890000)

[0021] The acid scavenger for cellulose ester resin contains a (meth)acrylic acid ester copolymer (A) as an essential component, and may contain a compatibilizer (C) that improves the dispersibility of the (meth)acrylic acid ester copolymer (A) in the cellulose ester resin as another component. As the compatibilizer (C), a compound having an ester group can be used, and preferred examples of the ester compound include polylactic acid having a formula weight or number average molecular weight of 500 to 5000, and polyester diols having aliphatic dicarboxylic acids having 2 to 8 carbon atoms (succinic acid, adipic acid, sebacic acid, etc.) and alkylene glycols having 2 to 4 carbon atoms (ethylene glycol, 1,4-butanediol, etc.) as constituent monomers and having a formula weight or number average molecular weight of 500 to 5000. More specifically, polylactic acid (PLADO-2000, manufactured by HighChem Co., Ltd., number average molecular weight 2000), polyethylene adipate diol (SunEstar 2620, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight 2000), and polyethylene butylene adipate diol (SunEstar 24620, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight 2000, etc.). Among these, polyester diols having a number average molecular weight of 500 to 5000 are preferred, polyethylene butylene adipate diols having a chemical formula weight or number average molecular weight of 500 to 5000 are more preferred, and polyethylene butylene adipate diols having a number average molecular weight of 1500 to 2500 are most preferred.

[0022] In the present invention, the compatibilizer (C) has a solubility parameter (SP value) of 10.5 to 11.7 (cal / cm) from the viewpoint of improving the dispersibility of the (meth)acrylic acid ester copolymer (A) in the cellulose ester resin. 3 ) 1 / 2 It is preferable that:

[0023] The SP value (solubility parameter) in the present invention [unit: (cal / cm 3 ) 1 / 2 can be determined by the method described in Japanese Patent No. 7248852.

[0024] When the acid scavenger for cellulose ester resin of the present invention contains a (meth)acrylic acid ester copolymer (A) and a compatibilizer (C), the (meth)acrylic acid ester copolymer (A) is preferably 50 to 99.9 wt % based on the total weight of the acid scavenger for cellulose ester resin, and the compatibilizer (C) is preferably 0.1 to 50 wt % based on the total weight of the acid scavenger for cellulose ester resin.

[0025] The acid scavenger for cellulose ester resin of the present invention can capture fatty acids generated by heating and mixing with cellulose ester resin when the cellulose ester resin is heated and melted, and can reduce the odor of fatty acids. As a method for heating and mixing together with the cellulose ester resin, a method for melt-kneading a powder mixture of the plasticized cellulose ester resin obtained by mixing the plasticizer with the cellulose ester resin and the acid scavenger, and a method for melt-kneading the cellulose ester resin, the plasticizer, and the acid scavenger simultaneously are preferred.

[0026] <Cellulose ester resin composition> The cellulose ester resin composition of the present invention contains a cellulose ester resin and the above-mentioned (meth)acrylic acid ester copolymer (A). As the (meth)acrylic acid ester copolymer (A), the (meth)acrylic acid ester copolymer (A) contained in the acid scavenger for cellulose ester resin can be used. As the cellulose ester resin, known cellulose ester resins can be used, and examples thereof include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate. Other examples include polycaprolactone-grafted cellulose acetate, methyl cellulose acetate, ethyl cellulose acetate, propyl cellulose acetate, hydroxyethyl cellulose acetate, and hydroxypropyl cellulose acetate. From the viewpoint of acid scavenging ability, cellulose acetate is preferred.

[0027] The cellulose ester resin is preferably a cellulose acetate having an average degree of substitution of 2.7 or less.

[0028] The average degree of substitution of cellulose acetate is as described in JP 2021-165333 A. It can be determined by the method described in the specification.

[0029] The cellulose ester resin contained in the cellulose ester resin composition of the present invention can be a commercially available cellulose ester resin, and the Acetyl series, Cellulone series (manufactured by Daicel Miraize) and the like to which a plasticizer has already been added can be used.

[0030] In the cellulose ester resin composition of the present invention, the weight proportion of the cellulose ester resin is 70 to 99.7% by weight, preferably 80 to 97% by weight, based on the total weight of the cellulose ester resin composition, from the viewpoints of mechanical properties and odor.

[0031] In the cellulose ester resin composition of the present invention, the weight ratio of the (meth)acrylic acid ester copolymer (A) is 0.3 to 15 weight % based on the total weight of the cellulose ester resin composition, and preferably 3 to 10 weight %. If the weight ratio of the acrylic acid ester copolymer (A) is less than 0.3 weight %, the odor of fatty acid cannot be sufficiently reduced, and if it is more than 15 weight %, the mechanical properties of the cellulose ester resin may deteriorate.

[0032] The cellulose ester resin composition of the present invention preferably contains a compound having an ester group other than the cellulose ester resin (hereinafter referred to as an ester compound), and the ester compound contained in the cellulose ester resin composition of the present invention is preferably a polylactic acid having a chemical formula weight or number average molecular weight of 500 to 5000, and a polyester diol having a chemical formula weight or number average molecular weight of 500 to 5000, which has an aliphatic dicarboxylic acid having 2 to 8 carbon atoms (succinic acid, adipic acid, sebacic acid, etc.) and an alkylene glycol having 2 to 4 carbon atoms (ethylene glycol, 1,4-butanediol, etc.) as a constituent monomer, more preferably a polyethylene butylene adipate having a chemical formula weight or number average molecular weight of 500 to 5000, and most preferably a polyethylene butylene adipate having a number average molecular weight of 1500 to 2500. The ester compound functions as a compatibilizer that improves the dispersibility of the (meth)acrylic acid ester copolymer (A) in the cellulose ester resin. The compatibilizer (C) may be the same as the compatibilizer (C) that may be contained in the acid scavenger for cellulose ester resin.

[0033] The ester compound has a solubility parameter (SP value) of 10.5 to 11.7 (cal / cm) from the viewpoint of improving the dispersibility of the (meth)acrylic acid ester copolymer (A) in the cellulose ester resin. 3 ) 1 / 2 It is preferable that:

[0034] When the cellulose ester resin composition contains a compound having an ester group, the content of the compound having an ester group is preferably 20% by weight or less, more preferably 1 to 20% by weight, based on the weight of the cellulose ester resin.

[0035] The cellulose ester resin composition of the present invention may contain other components, such as a plasticizer (D) and, depending on the application, conventional additives, such as other stabilizers (e.g., antioxidants, ultraviolet absorbers, heat stabilizers, light resistance stabilizers, etc.), colorants (dyes, pigments, etc.), antistatic agents, flame retardant assistants, lubricants, antiblocking agents, dispersants, fluidizing agents, dripping inhibitors, and antibacterial agents.

[0036] The plasticizer (D) is preferably contained in an amount of 5 to 40% by weight based on the weight of the cellulose ester resin.

[0037] As the plasticizer (D), for example, one selected from the following plasticizers can be used, or two or more of them can be used in combination. Aromatic carboxylate esters [Dialkyl phthalates (alkyl carbon number 1-12, hereinafter "alkyl carbon number" is represented as "C") such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate and di-2-ethylhexyl phthalate, alkoxy phthalates (alkoxy group carbon number 1-6) alkyl esters (C1-12) such as dimethoxyethyl phthalate, alkyl aryl phthalates (C1-12) such as butyl benzyl phthalate, Alkyl esters (C1-3), alkyl phthalyl (C1-6) alkylene glycolates (C2-4) such as ethyl phthalyl ethylene glycolate and butyl phthalyl butylene glycolate, trimellitic acid trialkyl esters (C1-12) such as trimethyl trimellitate, triethyl trimellitate, trioctyl trimellitate and tri-2-ethylhexyl trimellitate, pyromellitic acid tetraalkyl esters (C1-12) such as tetraoctyl pyromellitate, etc. Fatty acid esters [adipic acid esters such as dibutyl adipate, dioctyl adipate, butoxyethoxyethyl benzyl adipate, and dibutoxyethoxyethyl adipate, azelaic acid esters such as diethyl azelaate, dibutyl azelaate, and dioctyl azelaate, sebacic acid esters such as dibutyl sebacate, dioctyl sebacate, butyl oleate, and methylacetyl ricinoleate, etc.], Lower fatty acid esters of polyhydric alcohols (glycerin, trimethylolpropane, pentaerythritol, sorbitol, etc.) [diglycerin tetraacetate, etc.], glycol esters (dipropylene glycol dibenzoate, etc.), citrate esters [acetyl tributyl citrate, etc.], amides [N-butylbenzenesulfonamide, etc.], ester oligomers (caprolactone oligomer, etc.), Examples of the alkylene oxide adducts include alkylene oxide adducts of aliphatic polyhydric alcohols (such as alkylene glycol, glycerin, trimethylolpropane, pentaerythritol, and sorbitol) (polyethylene glycol, polypropylene glycol, glycerin ethylene oxide adduct, glycerin propylene oxide adduct, and glycerin ethylene oxide propylene oxide adduct).

[0038] The total weight ratio of the other components is preferably 1 to 50% by weight based on the total weight of the cellulose ester resin composition, from the viewpoint of the mechanical properties of the resin.

[0039] <Method of producing cellulose ester resin composition> The method for producing the cellulose ester resin composition of the present invention is not particularly limited, but examples thereof include a method in which the (meth)acrylic acid ester copolymer (A), the cellulose ester resin, and other components used as necessary are premixed by dry or wet mixing using a mixer such as a tumbler mixer, a Henschel mixer, or a ribbon mixer, and then melt-kneaded at 200° C. to 300° C. using an extruder such as a single-screw or twin-screw extruder, or a kneader such as a heated roll or a Banbury mixer. The order of mixing is not particularly limited, but when there are other components, examples include a method in which the cellulose ester resin and other components are kneaded, and then the (meth)acrylic acid ester copolymer (A) is added and kneaded, or a method in which the (meth)acrylic acid ester copolymer (A), the cellulose ester resin, and other components are premixed all at once and then kneaded.

[0040] The compatibilizer (C) may be included as a component constituting the acid scavenger for cellulose ester resin. When the compatibilizer (C) is not included as a component constituting the acid scavenger for cellulose ester resin, the mixture in which the acid scavenger for cellulose ester resin and the compatibilizer (C) are mixed in advance may be melt-kneaded with the cellulose ester resin, or the acid scavenger for cellulose ester resin may be added after melt-kneading the cellulose ester resin and the compatibilizer (C) in advance, or the acid scavenger for cellulose ester resin and the compatibilizer (C) may be melt-kneaded with the cellulose ester resin at the same time.

[0041] When a plasticizer (D) is contained, the cellulose ester resin may be melt-kneaded with the plasticizer (D) to obtain a plasticized cellulose ester resin, and then the acid scavenger for cellulose ester resin may be mixed with the plasticized cellulose ester resin and melt-kneaded. Alternatively, the cellulose ester resin, the plasticizer (D), and the acid scavenger for cellulose ester resin may be melt-kneaded simultaneously.

[0042] <Molded body of cellulose ester resin composition> The molded article of the cellulose ester resin composition of the present invention is the molded article of the cellulose ester resin composition. The molded article of the cellulose ester resin composition can be obtained by known methods such as injection molding, extrusion molding, vacuum molding, irregular molding, foam molding, injection press, press molding, blow molding, and gas injection molding. EXAMPLES

[0043] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these. The glass transition temperature was measured as follows.

[0044] <Glass transition temperature> Using a DSC measuring device, in accordance with JIS K7121:2012, about 10 mg of sample (meth)acrylic acid ester copolymer (A) is heated from 0°C to 150°C at a rate of 20°C / min under the condition of a nitrogen gas flow rate of 50 mL / min [first heating], and after reaching 150°C, it is held for 3 minutes, and then cooled to 0°C at a rate of 20°C / min. Next, the temperature is raised from 0°C to 150°C at a rate of 20°C / min [second heating]. The extrapolated glass transition onset temperature (Tig) (°C), which is the temperature of the intersection between the straight line extending the low-temperature side baseline of the DSC curve drawn during the second heating to the high-temperature side and the tangent drawn at the point where the gradient of the curve of the stepwise change part of the glass transition is maximum, is defined as the glass transition temperature (°C) in the present invention.

[0045] <Production of (meth)acrylic acid ester copolymer (A) and acid scavenger (E) for cellulose ester resin> Example 1 A mixed liquid of glycidyl methacrylate (a-1), other vinyl compound (a2) and a chain transfer agent in the amounts shown in Table 1 was prepared at room temperature to obtain a monomer solution. Separately, 0.5 parts by weight of t-butyl-peroxy-isopropyl-monocarbonate [product name: Perbutyl I, manufactured by NOF Corporation] was uniformly dissolved in 30 parts by weight of toluene at room temperature to obtain a polymerization initiator solution. 50 parts by weight of toluene was charged into a glass reaction vessel (polymerization vessel) equipped with a drip inlet, a reflux tube, and an agitator, and the temperature was raised to 110°C while stirring at a rotation speed of 200 rpm to create a reflux state. While maintaining the reflux state, the above-mentioned monomer solution and polymerization initiator solution were simultaneously charged in their entirety over 180 minutes under normal pressure, and stirring was continued for 180 minutes after the charging under normal pressure reflux to polymerize. After polymerization, the contents were transferred to an eggplant flask, and the toluene was desolvated at 80°C using an evaporator until the fluidity of the contents disappeared, and the eggplant flask residue was transferred to a stainless steel tray, and dried in a 100°C circulating air dryer for about 6 hours while appropriately mixing with a spatula. The obtained dried product was pulverized with a benchtop mill to obtain a (meth)acrylic acid ester copolymer (A-1). The epoxy equivalent of the obtained (meth)acrylic acid ester copolymer (A-1) was 145 g / eq and the glass transition temperature was 78°C. The (meth)acrylic acid ester copolymer (A-1) and the compatibilizer (C-1) were placed in equal amounts in a disposable cup and stirred with a stirring blade for 1 hour to obtain an acid scavenger (E-1) for cellulose ester resin of the present invention.

[0046] (Example 2) to (Example 8) and (Comparative Example 1) to (Comparative Example 5) The (meth)acrylic acid ester copolymers (A-2) to (A-8) according to Examples 2 to 8 and the (meth)acrylic acid ester copolymers (comparison A-1) to (comparison A-5) according to Comparative Examples 1 to 5 were obtained in the same manner as in Example 1, except that the glycidyl methacrylate (a-1), other vinyl compounds (a2), initiators and chain transfer agents were changed to the compounds and amounts shown in Table 1. The obtained (meth)acrylic acid ester copolymers (A-2) to (A-8) and (comparison A-1) to (comparison A-5) were used as acid scavengers (E-2) to (E-8) and (comparison E-1) to (comparison E-5) for cellulose ester resins of the present invention.

[0047] [Table 1]

[0048] The raw materials used in Table 1 other than those described in the above examples are as follows. <Other vinyl compounds (a2)> Methyl methacrylate (a2-1) [Tokyo Chemical Industry Co., Ltd.] 2-Hydroxyethyl methacrylate (a2-2) [Tokyo Chemical Industry Co., Ltd.] 2-Methoxyethyl acrylate (a2-3) [Tokyo Chemical Industry Co., Ltd.] Isobornyl methacrylate (a2-4) [Tokyo Chemical Industry Co., Ltd.]

[0049] <Production of Cellulose Ester Resin (B1)> (Production Example 1) 100 parts by weight of cellulose acetate [product name: cellulose acetate, Fujifilm Wako Pure Chemical Industries, Ltd., average substitution degree: 2.4, viscosity average polymerization degree: about 150, number average molecular weight: about 40,000] and 40 parts by weight of diethyl phthalate were placed in a disposable cup and mixed by stirring with a stirring blade for 5 minutes. The resulting mixture was kneaded for 15 minutes in a Labo Plastomill adjusted to 210°C to obtain a plasticized cellulose ester resin (B1-2).

[0050] (Production Example 2) A plasticized cellulose ester resin (B1-3) was obtained in the same manner as in Production Example 1, except that 40 parts by weight of diethyl phthalate was replaced with 25 parts by weight of a glycerin ethylene oxide adduct [product name: Newpol GE-600, manufactured by Sanyo Chemical Industries, Ltd.].

[0051] <Production of Cellulose Ester Resin Composition> Example 9 In a Labo Plastomill adjusted to 220°C, 100 parts by weight of cellulose acetate (B1-1) [product name: Cellulene EC210, manufactured by Daicel Miraizu Co., Ltd., average substitution degree: 2.4 to 2.5] and 3 parts by weight of a compatibilizer (C-1) were added and mixed for 2 minutes. Then, 3 parts by weight of a (meth)acrylic acid ester copolymer (A-1) was further added and mixed for 10 minutes at 220°C and 60 rpm to obtain a cellulose ester resin composition (X-1) of the present invention.

[0052] (Example 10) to (Example 29), (Comparative Example 6) to (Comparative Example 10), and (Reference Example 1) The cellulose ester resin compositions (X-2) to (X-21), (Comparative X-1) to (Comparative X-5) and (Reference X-1) according to Examples 10 to 29, Comparative Examples 6 to 10 and Reference Example 1 were obtained in the same manner as in Example 9, except that the amounts of the (meth)acrylic acid ester copolymer (A-1), the cellulose ester resin (B) and other components were changed to those shown in Tables 2 and 3.

[0053] Comparative Example 11 The cellulose ester resin composition (comparison E-6) was obtained by changing 3 parts by weight of (meth)acrylic acid ester copolymer (A-1) to 5 parts by weight of low molecular weight epoxy compound (trimethylolpropane polyglycidyl ether [manufactured by Nagase ChemteX Corporation, product name: Denacol EX-321, epoxy equivalent 140g / eq, number average molecular weight 350]) (comparison A-6) and using it as cellulose ester resin composition (comparison E-6). The cellulose ester resin (B) and other components were changed to the amounts shown in Table 3. The same procedure as in Example 9 was used to obtain a cellulose ester resin composition (comparison X-6) related to Comparative Example 11.

[0054] In (Example 9) to (Example 29), (Comparative Example 6) to (Comparative Example 11), and (Reference Example 1), the presence or absence of odor derived from fatty acids when kneaded at 220°C and 60 rpm for 10 minutes was evaluated, and the results are shown in Tables 2 and 3. In addition, the obtained cellulose ester resin compositions (X-1) to (X-21), (Comparative X-1) to (Comparative X-6), and (Reference X-1) were subjected to transparency evaluation, fatty acid capture rate evaluation, coloration evaluation, and bleed-out evaluation by the following test methods. The evaluation results are shown in Tables 2 and 3.

[0055] [Table 2]

[0056] [Table 3]

[0057] The raw materials used in Tables 2 and 3 other than those described in the above examples are as follows. <Cellulose ester resin (B)> Cellulose acetate butyrate (B2-1) [Product name: Cab 171-15, manufactured by Eastman Chemical Company, degree of substitution: 1.5] <Other ingredients> <Compatibilizer (C)> Polyethylene adipate diol (C-1) [Product name: SunEstar 2620, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight 2000, SP value: 11.3] Polyethylene butylene adipate diol (C-2) [Product name: Sun-Estar 24620, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight 2000, SP value: 11.6] Polylactic acid (C-3) [Product name: PLADO-2000, manufactured by HighChem Co., Ltd., number average molecular weight 2000, hydroxyl value 56 KOHmg / g, SP value: 11.6]

[0058] <Whether or not there is an odor when heating and kneading> In (Example 9) to (Example 29), (Comparative Example 6) to (Comparative Example 11), and (Reference Example 1), the presence or absence of an odor derived from fatty acids was confirmed by sniffing the upper part of the raw material inlet 8 minutes after starting the kneading process at 220°C and 60 rpm for 10 minutes, and the odor intensity was evaluated on the following 5-point scale, and the results are shown in Tables 2 and 3. Odor intensity 0: Odorless Odor Intensity 1: Smell that can barely be detected (detection threshold) Odor Intensity 2: Odor that can be identified (recognition threshold) Odor intensity 3: Easily detectable odor Odor intensity 4: Strong odor

[0059] <Transparency assessment> The obtained cellulose ester resin compositions (X-1) to (X-21), (Comparative X-1) to (Comparative X-6) and (Reference X-1) were visually evaluated for transparency, and the results are shown in Tables 2 and 3 using the following symbols. ○: Transparent ×: No transparency

[0060] <Evaluation of fatty acid capture rate> The fatty acid generated when the cellulose ester resins (B1-1), (B1-2), (B1-3) and (B2-1) used in (Example 9) to (Example 29), (Comparative Example 6) to (Comparative Example 11) are heated is acetic acid or acetic acid and butanoic acid. Therefore, the total amount of acetic acid and butanoic acid contained in the sample was measured by the following method, and the total amount of fatty acid contained in 1 g of the cellulose ester resin composition after melt kneading (Q) and the total amount of fatty acid contained in 1 g of the cellulose ester resin when only the cellulose ester resin is melt kneaded (Q0) were calculated using the following calculation formula. Fatty acid capture rate=100×(Q0-Q) / Q0 (calculation formula 1) A high fatty acid capture rate means that the fatty acid content in the molded product is low and odor is suppressed. In addition, for the fatty acid capture rate, for the cellulose ester resin compositions (X-1) to (X-6), (Comparative X-1) to (Comparative X-6) and (Reference X-1), the value of cellulose acetate (B1-1) was used as Q0; for the cellulose ester resin compositions (X-7) to (X-12), the value of cellulose ester resin (B1-2) was used as Q0; for the cellulose ester resin compositions (X-13) to (X-18), the value of cellulose acetate butyrate (B2-1) was used as Q0; and for the cellulose ester resin compositions (X-19) to (X-21), the value of cellulose ester resin (B1-3) was used as Q0.

[0061] <Measurement of the Total Content of Fatty Acids in the Cellulose Ester Resin Composition after Melt Kneading> The cellulose ester resin compositions (X) obtained in (Example 9) to (Example 29), (Comparative Example 6) to (Comparative Example 11), and (Reference Example 1) were left to stand in liquid nitrogen for 10 minutes, and then pulverized to obtain 5 g of powder, which was placed in a screw tube, to which 10 g of ultrapure water was added, and the mixture was stirred with a stirrer at 25°C for 1 hour. The mixture was then left to stand, and the supernatant was collected. The amount of fat contained in the supernatant was quantified using liquid chromatography under the following conditions, and the total content (Q) [unit: ppm] of fatty acids contained in the cellulose ester resin composition (1 g) after melt kneading was calculated. <Measurement of the total content of fatty acids contained in cellulose ester resin when only it is heated> Each of the cellulose ester resins (B1-1), (B1-2), (B1-3) and (B2-1) was melt-kneaded for 12 minutes in a Labo Plastomill adjusted to 220°C, and measurements were carried out in the same manner as for the cellulose ester resin composition (X), and the total fat content (Q0) contained in the cellulose ester resin (1 g) after melt-kneading was calculated. <Liquid chromatography measurement conditions> Equipment: LCMS-2010EV (Shimadzu Corporation) Column: CAPELL PAK C18 AQ (particle size 5 μm, inner diameter 4.6 mm, length 250 mm) Mobile phase: 0.05% phosphoric acid aqueous solution Flow rate: 0.8mL / min Oven temperature: 40℃ Detector: PDA (210 nm)

[0062] <With or without coloring> The obtained cellulose ester resin compositions (X-1) to (X-21), (Comparative X-1) to (Comparative X-6) and (Reference X-1) were visually evaluated for the presence or absence of coloration, and the results are shown in Tables 2 and 3 using the following symbols. ○: No coloring ×: Colored

[0063] <Whether or not there is bleed out> The surfaces of the obtained cellulose ester resin compositions (X-1) to (X-21), (Comparative X-1) to (Comparative X-6), and (Reference X-1) were checked for stickiness when touching the hands. If the hands were sticky, it was judged that there was bleed-out of the (meth)acrylic acid ester copolymer or the low molecular weight epoxy compound. If the hands were not sticky, it was judged that there was no bleed-out. The results are shown in Tables 2 and 3 with the following symbols. ○: No bleed out ×: Bleed out

[0064] As shown in Tables 2 and 3, the cellulose ester resin compositions of each Example had extremely good sensory evaluation during molding, high transparency, high acetic acid reduction rate, and no coloring or bleeding out, compared with the cellulose ester resin compositions of each Comparative Example.

Claims

1. An acid scavenger for cellulose ester resins, comprising a (meth)acrylic acid ester copolymer (A) having glycidyl (meth)acrylate as an essential constituent monomer, wherein the (meth)acrylic acid ester copolymer (A) has an epoxy equivalent of 140 g / eq or more and 750 g / eq or less, and the (meth)acrylic acid ester copolymer (A) has a glass transition temperature of 50° C. or more and 130° C. or less.

2. A cellulose ester resin composition comprising a cellulose ester resin and a (meth)acrylic acid ester copolymer (A), the (meth)acrylic acid ester copolymer (A) being a polymer containing glycidyl (meth)acrylate as an essential constituent monomer, the (meth)acrylic acid ester copolymer (A) having an epoxy equivalent of 140 g / eq or more and 750 g / eq or less, the (meth)acrylic acid ester copolymer (A) having a glass transition temperature of 50°C or more and 130°C or less, and the (meth)acrylic acid ester copolymer (A) comprising 0.3 to 15% by weight based on the total weight of the cellulose ester resin composition.

3. 3. The cellulose ester resin composition according to claim 2, wherein the cellulose ester resin is cellulose acetate.

4. A molded article of the cellulose ester resin composition according to claim 2 or 3.

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