Plasticizer for resin and resin composition

Abstract

To provide a polyester plasticizer having superior bleeding resistance compared to a polyester plasticizer having a structure in which both ends of a polymer chain having repeating units of an aliphatic dicarboxylic acid and a diol are blocked with an aliphatic monoalcohol. [Solution] A polyester obtained by the reaction of the following components (A) to (C): (A) A dicarboxylic acid represented by the following general formula (1) or an acid anhydride thereof. (B) A polyalkylene glycol having a number average molecular weight of 180 or more and an alkylene group having 1 to 8 carbon atoms and which may have a branch. (C) An alcohol represented by the following general formula (2): JPEG2026043150000008.jpg15150

Description

[Technical Field]

[0001] The present invention relates to a novel polyester and a resin composition containing the same. [Background technology]

[0002] Plastics such as polyester, polyolefin, polyamide, polyacetal, vinyl resin, styrene-based resin, acrylic resin, and cellulose-based resin are used in a wide range of fields, including food packaging, construction materials, and home appliances. In addition, various plasticizers are used to impart flexibility and other properties to these plastics, and plastic products with improved functionality are used in a variety of applications.

[0003] As examples of plastic products containing such plasticizers, Patent Document 1 describes a polyester-based plasticizer having a structure in which both ends of a polymer chain having repeating units of an aliphatic dicarboxylic acid and a diol are blocked with an aliphatic monoalcohol, a polyester resin composition containing the plasticizer, and a sheet and film made of the resin composition. It is disclosed that these products have good transparency, heat resistance, and bleeding resistance due to the inclusion of the polyester-based plasticizer.

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-199637 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned polyester plasticizers still do not have sufficient bleeding resistance. An object of the present invention is to provide a polyester plasticizer with even better bleeding resistance. [Means for solving the problem]

[0006] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have found that a polyester (plasticizer) obtained by reacting a specific dicarboxylic acid, a diol, and a monoalcohol, which will be described later, has excellent bleeding resistance and can solve the above-mentioned problems, thereby completing the present invention.

[0007] [1] A polyester obtained by the reaction of the following components (A) to (C): (A) The following general formula (1):

[0008] [ka] (In the formula, R1 is an alkylene group having 1 to 12 carbon atoms, which may be branched.) A dicarboxylic acid represented by the formula (I) or an acid anhydride thereof. (B) A polyalkylene glycol having a number average molecular weight of 180 or more and an alkylene group having 1 to 8 carbon atoms and which may have a branch. (C) the following general formula (2):

[0009] [ka] (In the formula, R2 is an alkyl group having 1 to 4 carbon atoms which may be branched or a phenoxy group, and n is an integer of 0 to 2. When n is 2, multiple R2s may be the same or different.) Alcohol represented by

[0010] [2] The polyester according to [1], wherein in the component (B), the polyalkylene glycol having an alkylene group having 1 to 8 carbon atoms, which may be branched, is at least one polyalkylene glycol selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytrimethylene glycol.

[0011] [3] A resin composition comprising the polyester according to [1] or [2] and a resin other than the polyester.

[0012] [4] The resin composition according to [3], wherein the other resin is a biodegradable resin.

[0013] [5] The resin composition according to [3], wherein the other resin is a polylactic acid-based resin. [Effects of the Invention]

[0014] According to the present invention, a polyester (plasticizer) having excellent bleeding resistance can be provided. Furthermore, when the polyester of the present invention is added to a resin (e.g., a polylactic acid-based resin), the resulting resin composition exhibits effects of little bleeding (i.e., excellent bleeding resistance) and excellent transparency and plasticity. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below. In this specification, when a numerical range is expressed as "A to B," it means A or more and B or less. In addition, in this specification, the term "comprise" is a concept that also encompasses "consist essentially of" and "consist only of."

[0016] [polyester] The polyester of the present invention is obtained by the reaction of the following components (A) to (C), and can be used as a plasticizer as it is. (A) The following general formula (1):

[0017] [ka] (In the formula, R1 is an alkylene group having 1 to 12 carbon atoms, which may be branched.) A dicarboxylic acid represented by the formula (I) or an acid anhydride thereof. (B) A polyalkylene glycol having a number average molecular weight of 180 or more and an alkylene group having 1 to 8 carbon atoms and which may have a branch. (C) the following general formula (3):

[0018] [ka] (In the formula, R2 is an alkyl group having 1 to 4 carbon atoms which may be branched or a phenoxy group, and n is an integer of 0 to 2. When n is 2, multiple R2s may be the same or different.) Alcohol represented by

[0019] The polyester of the present invention is a polyester containing the structural unit (a) derived from the component (A), the structural unit (b) derived from the component (B), and the structural unit (c) derived from the component (C), and typically consists essentially of the structural units (a), (b), and (c). The polyester of the present invention is a copolymer of the component (A), which is a dicarboxylic acid component, and the component (B), which is a diol component, and has a structure in which at least one polymer end is blocked with the component (C).

[0020] Component (A) is a dicarboxylic acid represented by the general formula (1) above or an acid anhydride thereof. In the general formula (1), R1 is an alkylene group having 1 to 12 carbon atoms, which may be branched. Examples of the alkylene group having 1 to 12 carbon atoms, which may be branched, in R1 include an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group. Among these, R1 is preferably an alkylene group having 1 to 8 carbon atoms, which may be branched, more preferably an alkylene group having 1 to 4 carbon atoms, and even more preferably an ethylene group or a tetramethylene group. Note that when a polyester obtained using a dicarboxylic acid (e.g., maleic acid, fumaric acid, etc.) in which R1 in the general formula (1) above is an alkenylene group, or an anhydride thereof, as component (A) is used as a resin composition described below, it may not plasticize other resins but may react with them to harden them, which is undesirable.

[0021] Specific examples of component (A) include malonic acid, methylmalonic acid, ethylmalonic acid, dimethylmalonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,2,3-trimethylsuccinic acid, 2-ethyl-2-methyl-succinic acid, glutaric acid, 2-methylglutaric acid, 2,2-dimethylglutaric acid, 2,4-dimethylglutaric acid, 3,3-dimethylglutaric acid, 3-ethyl-3-methylglutaric acid, adipic acid, 3-methyladipic acid, 2,2-dimethyladipic acid, pime Examples include phosphoric acid, suberic acid, azelaic acid, heptane-4,4-dicarboxylic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradodecanedioic acid, 1,1-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,1-cyclopentanediacetic acid, and acid anhydrides thereof. These may be used alone or in combination of two or more.

[0022] Component (B) is a polyalkylene glycol having an alkylene group having 1 to 8 carbon atoms, which may be branched, and a number-average molecular weight of 180 or more. Examples of the alkylene group having 1 to 8 carbon atoms, which may be branched, include an ethylene group, a propylene group, and a trimethylene group. Among these, an alkyl group having 1 to 4 carbon atoms, which may be branched, is preferred, and an ethylene group, a propylene group, or a trimethylene group is more preferred. The number-average molecular weight is preferably 180 to 2200, more preferably 180 to 1100, and even more preferably 180 to 640. The number-average molecular weight can be measured, for example, by the method described in the Examples section below.

[0023] Specific examples of component (B) include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, etc., having the above molecular weights. Note that simple compounds such as tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, tetratrimethylene glycol, pentatrimethylene glycol, and hexatrimethylene glycol are also included in the polyalkylene glycol. These may be used alone or in combination of two or more.

[0024] Component (C) is an alcohol represented by the above general formula (2). In the above general formula (2), R2 is an alkyl group having 1 to 4 carbon atoms, which may be branched, or a phenoxy group. Examples of the alkyl group having 1 to 4 carbon atoms, which may be branched, include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Among these substituents, a methyl group is preferred.

[0025] In the above general formula (2), n is an integer of 0 to 2, preferably 0 or 1. When n is 2, the multiple R2s may be the same or different.

[0026] Specific examples of component (C) include benzyl alcohol (n=0), 2-methylbenzyl alcohol, 3-methylbenzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, 3-ethylbenzyl alcohol, 4-ethylbenzyl alcohol, 2,3-dimethylbenzyl alcohol, 2,4-dimethylbenzyl alcohol, 3,5-dimethylbenzyl alcohol, 2,6-dimethylbenzyl alcohol, 4-isopropylbenzyl alcohol, 2,4,6-trimethylbenzyl alcohol, 3,4,5-trimethylbenzyl alcohol, 3-phenoxybenzyl alcohol, etc. These may be used alone or in combination of two or more.

[0027] The polyester of the present invention has, for example, a number average molecular weight of 300 to 10,000, preferably 350 to 4,000, and more preferably 400 to 2,000. The number average molecular weight can be measured, for example, by the method described in the Examples section below.

[0028] [Polyester manufacturing method] The polyester of the present invention can be obtained, for example, by subjecting the above components (A) to (C) to an esterification reaction using a conventional method. Examples of reaction methods include a single-stage method in which the above components (A) to (C) are reacted simultaneously, and a multi-stage method in which the above component (A) is reacted with the above component (B) and then the above component (C). The multi-stage method is preferred. The reaction is carried out, for example, at a temperature of 100°C to 300°C, in the presence of an acid and / or a catalyst, if necessary, and in the presence of a solvent such as toluene or xylene, while removing the generated water from the system. The reaction is preferably carried out under an inert gas atmosphere such as nitrogen or helium, or under a stream of air. The product obtained by the reaction may be distilled to remove unreacted raw materials, by-products, solvent, etc., according to conventional methods, and may also be purified by washing, adsorption, etc.

[0029] The molar ratio of the components (A) to (C) during the reaction is, for example, 1.0 mole of the component (A), 0.3 to 0.9 moles of the component (B), and 0.2 to 3.0 moles of the component (C).

[0030] [Resin composition] The resin composition of the present invention contains the polyester of the present invention described above and a resin, such as a polyester resin other than the polyester of the present invention, a polyolefin resin, a polyamide resin, a polyacetal resin, a vinyl resin, a styrene-based resin, or an acrylic resin.

[0031] Examples of the polyolefin resin include olefin homopolymers such as polyethylene, polypropylene, poly-1-butene, polymethylpentene, and polymethylbutene, and olefin copolymers such as propylene-ethylene random copolymers.

[0032] Examples of the polyamide resin include aliphatic polyamides such as nylon-6, nylon-66, nylon-10, nylon-12, and nylon-46, and aromatic polyamides produced from aromatic dicarboxylic acids and aliphatic diamines.

[0033] Examples of the polyacetal resin include polyformaldehyde, polyacetaldehyde, polypropionaldehyde, and polybutylaldehyde.

[0034] Examples of the vinyl resin include homopolymers such as polyvinyl chloride and polyvinylidene chloride, and vinyl compound copolymers such as copolymers of vinyl chloride or vinylidene chloride with vinyl acetate.

[0035] Examples of the styrene resin include polystyrene, AS resin, and ABS resin.

[0036] Examples of the acrylic resin include polyacrylic ester and polymethyl methacrylate.

[0037] Examples of the other polyester resins include aromatic polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; aliphatic aromatic copolyesters such as polybutylene succinate / terephthalate, polybutylene adipate / terephthalate, and polytetramethylene adipate / terephthalate; polycaprolactone, polyhydroxybutyrate (PHB), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), and poly(hydroxybutyrate-co-hydroxyhexamethyl). Examples of the polyhydroxyalkanoates include polyhydroxyalkanoates (PHAs) such as polybutylene succinate, polybutylene succinate-adipate copolymer, polyethylene succinate, polylactic acid resins, polymalic acid, polyglycolic acid, polydioxanone, and poly(2-oxetanone); and mixtures of natural polymers such as starch, cellulose, chitin, chitosan, gluten, gelatin, zein, soy protein, collagen, and keratin with the above-mentioned aliphatic polyesters or aliphatic aromatic copolyesters.

[0038] Among these resins, polyester resins that are decomposed into low molecular weight compounds in nature with the involvement of microorganisms (biodegradable) based on JIS K6953 (ISO14855) "Test for aerobic and ultimate biodegradability and disintegration under controlled aerobic compost conditions" are preferred, biodegradable aliphatic polyesters are more preferred, and polylactic acid resins are particularly preferred.

[0039] The polylactic acid resin is not particularly limited as long as it is a polyester resin obtained by polymerizing lactic acid, and examples thereof include a polylactic acid homopolymer, copolymer, blend polymer, etc. Examples of copolymers include copolymers of lactic acid with hydroxycarboxylic acids such as glycolic acid, hydroxypropionic acid, hydroxyheptanoic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and hydroxybenzoic acid, dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, glutaric acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and anthracenedicarboxylic acid, polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, octanediol, dodecanediol, neopentyl glycol, glycerin, pentaerythritol, sorbitan, bisphenol A, and polyethylene glycol, and lactones such as glycolide, caprolactone, butyrolactone, valerolactone, propylolactone, and undecalactone. Examples of blend polymers include mixtures of polylactic acid homopolymers and / or copolymers with celluloses, glycogen, chitin, chitosan, etc. The lactic acid used in the polymerization may be L-lactic acid, D-lactic acid, or a mixture thereof. These resins listed as resins contained in the resin composition of the present invention may be used alone or in combination of two or more.

[0040] In the resin composition of the present invention, the content of the polyester of the present invention is, for example, 1 to 100 parts by weight, preferably 1 to 50 parts by weight, and more preferably 5 to 30 parts by weight, per 100 parts of resin.

[0041] In the present invention, the method for blending the polyester of the present invention with a resin is not particularly limited, and examples thereof include a method of mixing using a blender, a mixer, etc., and a method of melt-kneading using an extruder, a Banbury mixer, a kneader, etc. Furthermore, a plasticizer may be mixed in the resin from the resin production stage.

[0042] In addition to the polyester of the present invention and the above-described resin, the resin composition of the present invention may contain other additives such as antiblocking agents, lubricants, antistatic agents, antifogging agents, ultraviolet absorbers, heat stabilizers, antioxidants, coloring inhibitors, fillers, pigments, dyes, dispersants, and flame retardants, depending on the intended use, within the scope of not impairing the object of the present invention. Furthermore, a compound generally used as a plasticizer other than the polyester of the present invention may also be used in combination.

[0043] The resin composition of the present invention can be molded using extrusion molding, injection molding, stretch film molding, blow molding, and other molding methods similar to those used for general thermoplastics, and is therefore useful in a wide range of applications, including food containers, electrical and electronic components, automotive parts, medical materials, film and sheet materials, fiber materials, paint resins, ink resins, toner resins, and adhesive resins. [Example]

[0044] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The number average molecular weights described in the examples are polystyrene-equivalent number average molecular weights measured by GPC (gel permeation chromatography) according to the measurement method described below.

[0045] Example 1 A four-neck flask equipped with a stirrer, nitrogen inlet, thermometer, and condenser, and an oil-water separator, was charged with 226.8 g (1.92 mol) of succinic acid, 191.4 g (0.96 mol) of polyethylene glycol #200 (number-average degree of polymerization n = 4, number-average molecular weight 184), 97 g of toluene, 12.0 g of paratoluenesulfonic acid monohydrate, and 2.5 g of sodium hypophosphite monohydrate. The esterification reaction was carried out at 110-120°C while removing the generated water from the system. After the theoretical amount of water was generated, 214.3 g (1.98 mol) of benzyl alcohol was added and the mixture was heated to 120-130°C. The esterification reaction was continued until the theoretical amount of water was generated. The mixture was cooled to 80°C, neutralized with 24% aqueous sodium hydroxide, and washed with water. Next, toluene and excess alcohol were removed under reduced pressure, followed by washing with alkali and water, and the water was removed under reduced pressure to obtain 476.9 g of a polyester (reaction product A) having a number average molecular weight of 457.

[0046] <Comparative Synthesis Example 1> Using the same reactor as in Example 1, 268.0 g (2.27 mol) of succinic acid, 171.3 g (1.14 mol) of triethylene glycol, 95 g of toluene, 14.0 g of paratoluenesulfonic acid monohydrate, and 3.2 g of sodium hypophosphite monohydrate were added and esterification reaction was carried out at 110-120 °C while removing the generated water from the system. After the theoretical amount of water was generated, 253.6 g (3.42 mol) of n-butanol was added and the mixture was heated to 100-120 °C. The esterification reaction was continued until the theoretical amount of water was generated. The mixture was cooled to 80 °C, neutralized with 24% aqueous sodium hydroxide, and washed with water. Next, the toluene and excess alcohol were removed under reduced pressure, followed by alkali washing and water washing. The water was removed under reduced pressure to obtain 332.3 g of polyester (reaction product B) with a number-average molecular weight of 778.

[0047] <Comparative Synthesis Example 2> Using the same reactor as in Example 1, 236.9 g (1.62 mol) of adipic acid, 161.3 g (0.81 mol) of polyethylene glycol #200 (average degree of polymerization n = 4, number-average molecular weight 184), 102 g of toluene, 10.1 g of paratoluenesulfonic acid monohydrate, and 2.1 g of sodium hypophosphite monohydrate were added and esterification reaction was carried out at 110-120 °C while removing the generated water from the system. After the theoretical amount of water was generated, 269.3 g (1.66 mol) of diethylene glycol monobutyl ether was added and the mixture was heated to 120-130 °C. The esterification reaction was continued until the theoretical amount of water was generated. The mixture was cooled to 80 °C, neutralized with 24% aqueous sodium hydroxide, and washed with water. Next, the toluene and excess alcohol were removed under reduced pressure, followed by alkali washing and water washing. The water was removed under reduced pressure to obtain 522.1 g of polyester (reaction product C) with a number-average molecular weight of 966.

[0048] <Comparative Synthesis Example 3> Using the same reactor as in Example 1, 476.1 g (4.02 mol) of succinic acid, 125.3 g (2.01 mol) of ethylene glycol, 159 g of toluene, 6.3 g of paratoluenesulfonic acid monohydrate, and 1.3 g of sodium hypophosphite monohydrate were added and esterification reaction was carried out at 110-120 °C while removing the generated water from the system. After the theoretical amount of water was generated, 449.9 g (4.12 mol) of benzyl alcohol was added and the mixture was heated to 120-130 °C. The esterification reaction was continued until the theoretical amount of water was generated. The mixture was cooled to 80 °C, neutralized with a 24% aqueous solution of NaOH, and washed with water. Next, the toluene and excess alcohol were removed under reduced pressure, followed by alkali washing and water washing. The water was removed under reduced pressure to obtain 761.5 g of polyester (reaction product D) with a number-average molecular weight of 343.

[0049] [Number average molecular weight measurement] Using polystyrene of known molecular weight as a standard substance, the measurement was carried out by GPC under the following conditions. ·Equipment used: HLC-8320 (manufactured by Tosoh Corporation) Columns: TSKgel SuperHZ1000 + TSKgel SuperHZ2500 + TSKgel SuperHZ4000 + TSKgel guardcolumn SuperHZ-L, one each in series Solvent (carrier): THF (tetrahydrofuran) ·Flow rate: 0.350mL / min Column temperature: 40℃ Detector: RI ·Injection volume: 10μL Sample preparation: Approximately 0.1 g of the compound to be measured was dissolved in 5 mL of THF. ·How to calculate number average molecular weight (Mn): The multimodal peaks obtained by the GPC measurement were treated as a single group, and the peaks corresponding to the organic solvent were excluded to calculate the number average molecular weight (Mn).

[0050] <Example 2 and Comparative Examples 1 to 6> A plasticizer was added to 100 parts by weight of polylactic acid (PLA) resin (Ingeo 4032D (Nature Works)) as shown in Table 1, and the mixture was melt-kneaded at a set temperature of 190°C using a Labo Plastomill (Toyo Seiki Seisakusho Co., Ltd.) to obtain a resin composition. This resin composition was compression-molded at 180°C and cooled to 25°C to produce a test sheet with a thickness of approximately 1 mm. Performance evaluation was performed using this test sheet under the conditions described below. The evaluation results are summarized in Table 1.

[0051] [Transparency Assessment] A test sheet approximately 1 mm thick was left to stand for 24 hours in an environment of 23°C and 50% humidity, and then the haze value of the test film was measured using a haze meter NDH4000 (manufactured by Nippon Denshoku Industries Co., Ltd.) Note that if the haze value is equal to or lower than that of Comparative Example 1 (no plasticizer added), it indicates that the inherent transparency of the polylactic acid resin is not impaired and that the transparency is excellent.

[0052] [Plasticity evaluation] A test sheet approximately 1 mm thick was punched out using a No. 3 dumbbell, and the dumbbell was left standing in a thermostatic chamber at 23°C and 50% RH for 24 hours. After that, a tensile test was carried out at a pulling rate of 200 mm / min, and the tensile breaking elongation (%) was calculated from the elongation at which the sample broke. Note that a larger value for the tensile breaking elongation (%) indicates higher plasticity.

[0053] [Bleeding evaluation] A test sheet with a thickness of about 1 mm was prepared and the weight of the sheet was measured.The test sheet was then left to stand in an 80°C atmosphere for 24 hours, and the plasticizer that had bled out from the surface of the test sheet was wiped off.The weight of the test sheet was then measured, and the weight loss rate was calculated from the weight before and after the test.A smaller weight loss rate indicates higher bleeding resistance.

[0054] [Table 1]

[0055] ATBC: Acetyl tributyl citrate (manufactured by Taoka Chemical Co., Ltd.) SR-86A: Butoxyethoxyethyl adipate (Taoka Chemical Co., Ltd.)

Claims

1. A polyester obtained by the reaction of the following components (A) to (C): (A) The following general formula (1): (In the formula, R １ is an alkylene group having 1 to 12 carbon atoms, which may be branched. A dicarboxylic acid represented by the formula (I) or an acid anhydride thereof. (B) A polyalkylene glycol having an alkylene group having 1 to 8 carbon atoms and which may have a branch, and which has a number average molecular weight of 180 or more. (C) the following general formula (2): (In the formula, R ２ is an alkyl group having 1 to 4 carbon atoms which may be branched or a phenoxy group, and n is an integer of 0 to 2. When n is 2, there are multiple R ２ may be the same or different.) Alcohol represented by

2. 2. The polyester according to claim 1, wherein in component (B), the polyalkylene glycol having an alkylene group having 1 to 8 carbon atoms, which may be branched, is at least one polyalkylene glycol selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytrimethylene glycol.

3. A resin composition comprising the polyester according to claim 1 or 2 and a resin other than the polyester.

4. The resin composition according to claim 3, wherein the other resin is a biodegradable resin.

5. The resin composition according to claim 3, wherein the other resin is a polylactic acid resin.

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