JP4439981B2 - Plasticizer for polyester resin - Google Patents

Description

  The present invention relates to a plasticizer for a polyester resin and a polyester resin composition excellent in flexibility, bleed resistance, volatilization resistance and fogging resistance.

  General-purpose resins made from petroleum, such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene, are lightweight and have good processability, physical properties, and durability. Used in various fields such as building materials and food packaging. However, these resin products have a disadvantage of good durability at the stage of finishing and discarding their functions, and are inferior in degradability in nature, and thus may affect the ecosystem.

  In order to solve such problems, as a polymer having a biodegradability with a thermoplastic resin, polylactic acid, a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid, an aliphatic polyhydric alcohol and an aliphatic polyvalent carboxylic acid are used. Biodegradable polyester resins such as aliphatic polyesters derived from acids and copolymers containing these units have been developed.

  These biodegradable polyester resins, when placed in soil, seawater, or the body of an animal, begin to degrade in a few weeks due to the action of enzymes produced by naturally occurring microorganisms. Disappears within a few years. Furthermore, the decomposition products become lactic acid, carbon dioxide, water, etc., which are harmless to the human body. Among the aliphatic polyesters, polylactic acid resin is made of a large amount of L-lactic acid by a fermentation method from sugars obtained from corn, straw, etc., and has become inexpensive. In addition, as the performance of the polymer obtained is characterized by high rigidity and good transparency, it is expected to be used at present, such as flat yarns, nets, gardening materials, seedling pots and other agricultural civil engineering materials fields, windows Used in envelopes, shopping bags, compost bags, stationery, miscellaneous goods, etc. However, in the case of polylactic acid resin, it is brittle, hard, and lacks flexibility, so all are limited to the field of hard molded products, and when molded into a film or the like, it is insufficient in flexibility or bent. At present, there are problems such as whitening, and it is not used in the soft or semi-rigid field.

Various methods of adding a plasticizer have been proposed as a technique applied to the soft and semi-rigid fields. For example, a technique of adding a plasticizer such as tributyl acetyl citrate (Patent Document 1), diglycerin tetraacetate or the like (Patent Document 2) is disclosed. However, when these plasticizers are used, the plasticizer smokes violently during the molding process and the working environment deteriorates, and the volatile and agglomerated plasticizer adheres to the molded product, resulting in a reduction in commercial value and yield. Therefore, there is a problem that leads to a decrease in productivity and an increase in cost. In addition, automotive skin panels such as instrument panels, door trims, and leather for seats can be considered as examples of applications in the soft field. . Under such circumstances, interior skin materials using plasticizers such as those mentioned above are subject to this field because the added plasticizer volatilizes and sublimes at high temperatures, causing fogging phenomenon that fogs windshields and transparent plastic parts. I couldn't apply it.
Japanese Patent No. 3105020 JP 2003-138118 A

  An object of the present invention is to provide a polyester resin plasticizer capable of imparting flexibility to a polyester resin, excellent in volatility resistance and fogging resistance, and capable of suppressing smoke generation of a plasticizer during processing, and flexibility. Another object of the present invention is to provide a polyester resin composition excellent in bleed resistance, volatilization resistance and fogging resistance.

  The present invention is a trivalent or higher aliphatic polyvalent carboxylic acid, a trivalent or higher aromatic polyvalent carboxylic acid, a condensed polycyclic aromatic carboxylic acid, and an alicyclic carboxylic acid, or an anhydride thereof, or a Esters of at least one acid component selected from lower alkyl esters having 1 to 3 carbon atoms and at least one alcohol component selected from alkylene oxide adducts of monovalent or divalent alcohols (hereinafter referred to as esters of the present invention) And a polyester resin composition containing the polyester resin and the plasticizer.

  The plasticizer of the present invention can impart flexibility to the polyester resin, can impart excellent volatility resistance and fogging resistance, and can suppress smoke generation of the plasticizer during processing. Further, the polyester resin composition of the present invention is excellent in flexibility, bleed resistance, volatilization resistance and fogging resistance.

[Plasticizer]
The acid component constituting the ester of the present invention is a trivalent or higher aliphatic polyvalent carboxylic acid, a trivalent or higher aromatic polyvalent carboxylic acid, a condensed polycyclic aromatic carboxylic acid, and an alicyclic carboxylic acid, or It is at least one selected from those anhydrides or their lower alkyl esters having 1 to 3 carbon atoms. The acid component referred to in the present invention includes an acid anhydride and a lower alkyl ester of an acid.

  As the trivalent or higher aliphatic polyvalent carboxylic acid, from the viewpoint of expressing the effects of the present invention, a trivalent to hexavalent aliphatic polyvalent carboxylic acid is preferable, and a trivalent or tetravalent aliphatic polyvalent carboxylic acid is preferable. More preferred. The number of carbon atoms of the trivalent or higher aliphatic polyvalent carboxylic acid is preferably 6 to 20 and more preferably 8 to 12 from the viewpoint of expressing the effects of the present invention. These aliphatic polyvalent carboxylic acids preferably have no substituent other than a carboxyl group, such as a hydroxyl group or an acyl group, from the viewpoints of compatibility with the resin, transparency and bleed resistance. Specific examples of these aliphatic polyvalent carboxylic acids include 1,3,6-hexanetricarboxylic acid and 1,2,3,4-butanetetracarboxylic acid.

  The trivalent or higher aromatic polyvalent carboxylic acid is preferably a trivalent or tetravalent aromatic polyvalent carboxylic acid. Specific examples include trimellitic acid and pyromellitic acid.

  The condensed polycyclic aromatic carboxylic acid is preferably a condensed polycyclic aromatic carboxylic acid having 1 to 4 carboxyl groups in one molecule, particularly a condensed polycyclic aromatic carboxylic acid having a naphthalene ring. Specific examples include 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, and the like.

  The alicyclic carboxylic acid is preferably an alicyclic carboxylic acid having 1 to 4 carboxyl groups in one molecule, particularly an alicyclic carboxylic acid having a C 5-7 cycloalkane ring. Specific examples include 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, cyclohexanecarboxylic acid, cyclopentanecarboxylic acid, cycloheptanecarboxylic acid, 1,2,3,4-cyclohexanetetracarboxylic acid, and the like. It is done.

  Among these acid components, trivalent or higher aliphatic polyvalent carboxylic acids, trivalent or higher aromatic polyvalent carboxylic acids, anhydrides thereof, or lower alkyl esters having 1 to 3 carbon atoms thereof are preferable.

  The alcohol component constituting the ester of the present invention is at least one selected from alkylene oxide adducts of monovalent or divalent alcohols. The monovalent or divalent alcohol is preferably an alcohol having 1 to 18 carbon atoms, more preferably a linear or branched aliphatic monohydric alcohol having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms. The alkylene oxide is preferably an alkylene oxide having 2 to 4 carbon atoms, and more preferably ethylene oxide. Moreover, 0.2-20 are preferable and, as for the average added mole number of alkylene oxide, 0.5-10 are more preferable.

  The ester of the present invention may be either a saturated ester in which all of the carboxyl groups of the acid component are esterified with an alcohol component, or a partial ester in which a part of the carboxyl group is esterified. From the viewpoint, a saturated ester is preferable.

  The number average molecular weight of the ester of the present invention is preferably 450 or more, and more preferably 500-1500, from the viewpoint of bleed resistance and volatile resistance.

  The number average molecular weight of the ester of the present invention is a value measured by the following method.

<Measurement method of number average molecular weight>
Measurement is performed under the following conditions by GPC (gel permeation chromatography).
Column: TSK PWXL + G4000PWXL + G2500PWXL (both manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Detector: RI or UV (210 nm)
Eluent: 0.2 mol / L phosphate buffer / acetonitrile (9/1)
Flow rate: 1.0 mL / min
Injection volume: 0.1 mL
Standard: Polyethylene glycol The ester of the present invention can be obtained by esterification reaction or transesterification reaction between the acid component and the alcohol component as described above, and its production method is not particularly limited.

  The plasticizer of the present invention can contain, in addition to the ester of the present invention, unreacted components in the production of the ester of the present invention, esters other than the ester of the present invention, plasticizers, and the like.

  Examples of esters other than the ester of the present invention include dipropylene glycol dibenzoate, ethylene glycol dibenzoate, neopentyl glycol dibenzoate, and polyoxyethylene methyl ether adipic acid diester. Examples of the plasticizer other than the ester of the present invention include acetylated monoglyceride and acetylated tributyl citrate.

  The content of the ester of the present invention in the plasticizer of the present invention is preferably 50% by weight or more, more preferably 70% by weight or more, and further preferably 90% from the viewpoint of achieving the object of the present invention. % By weight or more.

[Polyester resin]
Although it does not specifically limit as polyester resin concerning this invention, The polyester obtained by condensation reaction of dicarboxylic acid or its ester-forming derivative, and diol or its ester-forming derivative, The polyester obtained by the condensation reaction of hydroxycarboxylic acid A mixture of these polyesters and a transesterification product of the mixture are suitable.

  Specific examples of the polyester resin include aromatic polyesters such as polyalkylene terephthalates including polyalkylene terephthalates such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, and polyalkylene naphthalates such as polyethylene naphthalate and polybutylene naphthalate. Resin; Aliphatic polyester resin such as polyester of adipic acid and 1,4-butanediol; Polyether ester resin in which a part of the diol component is substituted with alkylene glycol such as polyethylene glycol; Polyhydroxybutyrate, polycaprolactone, poly Butylene succinate, polybutylene succinate / adipate, polyethylene succinate, polylactic acid resin, polymalic acid, polyglycol Biodegradable aliphatic polyesters such as polydioxanone and poly (2-oxetanone); biodegradable aliphatic aromatic copolyesters such as polybutylene succinate / terephthalate, polybutylene adipate / terephthalate, and polytetramethylene adipate / terephthalate It is done. These can be used alone or in combination. Among these, a biodegradable resin is preferable from the viewpoint of exerting influence on the ecosystem and the effects of the present invention.

  The biodegradable resin used in the present invention refers to biodegradability based on JIS K6953 (ISO 14855) "Aerobic and ultimate biodegradability and disintegration tests under controlled aerobic compost conditions". It is a polyester resin.

  The biodegradable resin used in the present invention is not particularly limited as long as it has a biodegradability capable of being decomposed into a low molecular weight compound with the participation of microorganisms in nature. For example, aliphatic polyesters such as polyhydroxybutyrate, polycaprolactone, polybutylene succinate, polybutylene succinate / adipate, polyethylene succinate, polylactic acid resin, polymalic acid, polyglycolic acid, polydioxanone, poly (2-oxetanone) Aliphatic aliphatic copolyesters such as polybutylene succinate / terephthalate, polybutylene adipate / terephthalate, polytetramethylene adipate / terephthalate; starch, cellulose, chitin, chitosan, gluten, gelatin, zein, soy protein, collagen, keratin, etc. And a mixture of the above natural polymer and the above aliphatic polyester or aliphatic aromatic copolyester.

  Of these, aliphatic polyesters are preferable from the viewpoint of processability, economy, and availability in large quantities, and polylactic acid resins are more preferable from the viewpoint of physical properties. Here, the polylactic acid resin is polylactic acid or a copolymer of lactic acid and hydroxycarboxylic acid. Examples of the hydroxycarboxylic acid include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid and the like, and glycolic acid and hydroxycaproic acid are preferable. A preferred molecular structure of polylactic acid is composed of 20 to 100 mol% of either L-lactic acid or D-lactic acid and 0 to 20 mol% of each enantiomer. The copolymer of lactic acid and hydroxycarboxylic acid is composed of 85 to 100 mol% of either L-lactic acid or D-lactic acid and 0 to 15 mol% of hydroxycarboxylic acid units. These polylactic acid resins can be obtained by dehydrating polycondensation using L-lactic acid, D-lactic acid and hydroxycarboxylic acid as a raw material by selecting those having the required structure. Preferably, it can be obtained by ring-opening polymerization by selecting a desired structure from lactide, which is a cyclic dimer of lactic acid, glycolide, which is a cyclic dimer of glycolic acid, and caprolactone. Lactide includes L-lactide which is a cyclic dimer of L-lactic acid, D-lactide which is a cyclic dimer of D-lactic acid, meso-lactide obtained by cyclic dimerization of D-lactic acid and L-lactic acid, and D-lactide. There is DL-lactide, which is a racemic mixture of lactide and L-lactide. Any lactide can be used in the present invention. However, the main raw material is preferably D-lactide or L-lactide.

  Examples of commercially available biodegradable resins include DuPont, trade name Biomax; BASF, trade name Ecoflex; Eastman Chemicals, trade name EsterBio; Showa Polymer Co., Ltd., trade name Bionore; Nippon Synthetic Chemical Industry Co., Ltd., trade name: Matterby; Mitsui Chemicals, Inc., trade name: Lacia; Nippon Shokubai Co., Ltd., trade name: Lunare; Chisso Corporation, trade name: Novon; Cargill Dow Polymers The product name Nature Works etc. is mentioned.

  Among these, a polylactic acid resin (for example, Mitsui Chemicals, Inc., trade name Lacia H-100, H-280, H-400, H-440; Cargill Dow Polymers, trade name Nature Works) is preferable. ), Aliphatic polyesters such as polybutylene succinate (product name Bionore, manufactured by Showa Polymer Co., Ltd.), aliphatic aromatic copolyesters such as poly (butylene succinate / terephthalate) (trade name Bio, manufactured by DuPont) Max).

  From the viewpoint of heat resistance, a crystalline biodegradable resin having a high L-lactic acid purity is preferable, and orientation crystallization is preferably performed by stretching. Examples of the crystalline biodegradable resin include Lacia H-100, H-400, and H-440 manufactured by Mitsui Chemicals.

[Polyester resin composition]
The polyester resin composition of the present invention contains the plasticizer of the present invention and a polyester resin. The content of the plasticizer of the present invention is preferably 1 to 70 parts by weight, more preferably 100 parts by weight of the polyester resin, from the viewpoints of flexibility, bleed resistance, volatilization resistance, fogging resistance and economy. 3 to 50 parts by weight, particularly preferably 5 to 30 parts by weight.

  From the viewpoint of achieving the object of the present invention, the content of the polyester resin in the polyester resin composition of the present invention is preferably 50% by weight or more, and more preferably 70% by weight or more.

  The composition of the present invention can contain other components such as a lubricant in addition to the plasticizer. Examples of the lubricant include hydrocarbon waxes such as polyethylene wax, fatty acids such as stearic acid, fatty acid esters such as glycerol ester, metal soaps such as calcium stearate, ester waxes such as montanic acid wax, and alkylbenzene sulfone. Anionic surfactants having an aromatic ring such as acid salts, anionic surfactants having an alkylene oxide addition moiety such as polyoxyethylene alkyl ether sulfate, and the like. The content of these lubricants is preferably 0.05 to 3 parts by weight and more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the polyester resin.

  The composition of the present invention includes an antistatic agent, an antifogging agent, a light stabilizer, an ultraviolet absorber, a pigment, an inorganic filler, an antifungal agent, an antibacterial agent, a foaming agent, a flame retardant, Plasticizers other than the plasticizer of the present invention can be contained as long as the object of the present invention is not hindered.

  Since the composition of the present invention has good processability and can be processed at a low temperature such as 160 to 190 ° C., it can be calendered and the plasticizer is hardly decomposed. The composition of the present invention can be formed into a film or sheet and used for various applications.

  The present invention is a trivalent or higher aliphatic polyvalent carboxylic acid, a trivalent or higher aromatic polyvalent carboxylic acid, a condensed polycyclic aromatic carboxylic acid, and an alicyclic carboxylic acid, or an anhydride thereof, or a A plasticizer comprising an ester of at least one acid component selected from lower alkyl esters having 1 to 3 carbon atoms and at least one alcohol component selected from an alkylene oxide adduct of a monovalent or divalent alcohol. It is characterized by its use, and by using this plasticizer, it is possible to give flexibility to the polyester resin, give it excellent volatilization resistance and fogging resistance, and suppress fuming of the plasticizer during processing. can do. The reason why the effects of the present invention are manifested is not clear, but based on the results that the plasticizer of the present invention has a structure in which an alkylene oxide chain is introduced, the compatibility with the resin and the plasticizing efficiency are excellent. It is considered that the effect of the present invention is manifested because the interaction between the polymer molecules constituting it is efficiently reduced to facilitate the movement of the polymer molecular chain (micro Brownian motion).

Synthesis example 1
With respect to 1 mol of 1,3,6-hexanetricarboxylic acid (TCX-21 manufactured by Asahi Kasei Co., Ltd.), 3.3 mol of diethylene glycol monobutyl ether (BDG manufactured by Nippon Emulsifier Co., Ltd.) and dibutyltin oxide were charged to 0.03. 1% by weight was added and an esterification reaction was carried out at 200 ° C. After completion of the reaction at an acid value of 1 or less, the product was subjected to steam distillation under reduced pressure, and the unreacted product contained was distilled off to obtain 1,3,6-hexanetricarboxylic acid POE (2) butyl ether triester. .

Synthesis example 2
1,3,6-hexanetricarboxylic acid POE (2) hexyl ether triester was obtained in the same manner as in Synthesis Example 1 except that 3.3 mol of diethylene glycol monohexyl ether was used instead of diethylene glycol monobutyl ether.

Synthesis example 3
To 1 mol of trimellitic anhydride (reagent manufactured by Wako Pure Chemical Industries, Ltd.), 3.3 mol of polyethylene glycol (EO = 4.5) monomethyl ether (MPG manufactured by Nippon Emulsifier Co., Ltd.) and dibutyltin oxide were charged. The esterification reaction was performed at 220 ° C. in an amount of 0.1% by weight. After completion of the reaction at an acid value of 1 or less, the product was subjected to steam distillation under reduced pressure to distill off the unreacted substances contained therein, thereby obtaining trimellitic acid POE (4.5) methyl ether triester.

Examples 1-3 and Comparative Examples 1-3
As a polyester resin, a composition comprising 100 parts by weight of a polylactic acid resin (manufactured by Mitsui Chemicals, LACEA H-280) and a plasticizer of the type and amount shown in Table 1 in a 4-inch roll at 130 ° C. And kneaded for 15 minutes, and a test piece having a thickness of 0.5 mm was prepared with a 160 ° C. press molding machine.

  The obtained test pieces were evaluated for flexibility, transparency, surface condition, volatilization resistance and fogging resistance by the following methods. Further, this test piece was bent by 108 ° by hand, and the presence or absence of whitening was observed with the naked eye. These results are shown in Table 1.

<Flexibility evaluation method>
The test piece was punched out with a No. 3 dumbbell, left in a constant temperature room at a temperature of 23 ° C., and a humidity of 50% RH for 24 hours.

<Transparency evaluation method>
The haze value of the test piece was measured using an integrating sphere light transmittance measuring device (haze meter) defined in JIS-K7105. Smaller numbers indicate better transparency.

<Surface condition (with or without bleeding)>
The test piece (length 100 mm × width 100 mm, thickness 0.5 mm) was left in a thermostatic chamber at 40 ° C. for 1 week, and the presence or absence of plasticizer bleeding on the surface was observed with the naked eye.

<Evaluation method for volatile resistance (residual amount of heating)>
Weigh 15 mg of plasticizer in an aluminum pan and use SSC-5000 thermal analysis unit manufactured by Seiko Denshi Kogyo Co., Ltd. to raise the temperature from 30 ° C. to 300 ° C. at 5 ° C./min under the condition of a nitrogen flow rate of 200 ml / min. This was evaluated by the residual amount of heat at 250 ° C. The larger this value, the better the volatility resistance.

<Evaluation method of fogging resistance>
A plate-like test piece of 50 mm × 100 mm × 0.5 mm was set in a glass fogging (fogging) test apparatus compliant with ISO-6542 and treated at a heating temperature of 90 ° C. and a heating time of 20 hours. The haze value of the obtained test piece was measured using an integrating sphere light transmittance measuring device (haze meter) defined in JIS-K7105. The smaller this value, the better the fogging resistance.

Claims (2)

At least selected from 1,3,6-hexanetricarboxylic acid and alkylene oxide adducts of linear or branched aliphatic monohydric alcohols having 1 to 12 carbon atoms (average number of added moles of alkylene oxide of 0.5 to 10) A plasticizer for a biodegradable polyester resin containing an ester with one alcohol component (hereinafter referred to as an ester of the present invention).   The polyester resin composition containing a biodegradable polyester resin and the plasticizer of Claim 1 (1-50 weight part with respect to 100 weight part of biodegradable polyester resin).