JP4694173B2 - Additive for polyester resin - Google Patents

Description

  The present invention relates to an additive for polyester resin, a polyester resin composition containing the additive, and a method for producing the same.

  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.

  When these biodegradable polyester resins are placed in soil, seawater, or the body of an animal, they start 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 has been made inexpensive by producing a large amount of L-lactic acid from sugars obtained from corn, straw, etc., and the raw material is a natural crop, so the total carbon dioxide emissions are extremely low. In addition, since the obtained polymer has characteristics such as high rigidity and good transparency, it is expected to be used at present, and the field of agricultural civil engineering materials such as flat yarn, nets, horticultural materials, seedling pots, with windows Used for envelopes, shopping bags, compost bags, stationery, miscellaneous goods, etc. However, since the crystallization rate of polylactic acid is significantly slower than that of polyolefin or the like, there are problems such as a decrease in heat resistance due to insufficient crystallization and an increase in cost due to a decrease in molding efficiency.

Polylactic acid is brittle, hard, and lacks flexibility, so it is limited to the field of hard molded products. When it is molded into a film, problems such as lack of flexibility or whitening when folded The current situation is that 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 acetylcitrate or diglycerin tetraacetate is disclosed. When these plasticizers are added to polylactic acid and a film or sheet is formed by extrusion or the like, good flexibility is obtained, but because the polymer is in an amorphous state, it is flexible due to temperature changes near the glass transition point. There is a problem that the change in properties is remarkable (temperature sensitivity) and the heat resistance at high temperatures is insufficient, so that the physical properties change remarkably depending on the season, making it impossible to use in high temperature environments. In order to solve this problem, polylactic acid is crystallized by adding a crystal nucleating agent such as talc (Patent Document 1) or montmorillonite intercalated with dioctadecyldimethylammonium cation (organic modified montmorillonite) (Patent Document 2). And a method for improving heat resistance and the like has been proposed. However, the crystallization rate by heat treatment after molding is still insufficient. Further, when organically modified layered silicate is used as a crystal nucleating agent, the silicate layer needs to be highly dispersed in the resin, and a dispersing device having a large shearing force may be required.
Japanese Patent No. 3410075 JP 2003-82212 A

  The subject of this invention is providing the polyester resin additive which can improve the crystallization speed | rate of a polyester resin, the polyester resin composition containing the same, and its manufacturing method.

  In the present invention, the crystal system is hexagonal, cubic, tetragonal, trigonal or orthorhombic, and at least one lattice constant of a-axis, b-axis, and c-axis is 7 to Provided are an additive for a polyester resin containing an inorganic compound of 15 angstroms, a polyester resin, a polyester resin composition containing the additive, and a method for producing the same.

  The additive for polyester resin of the present invention (hereinafter referred to as additive of the present invention) can improve the crystallization rate of the polyester resin.

[Additives for polyester resins]
The additive of the present invention has a crystal system of hexagonal system, cubic system, tetragonal system, trigonal system or orthorhombic system, and at least one lattice constant of a-axis, b-axis, and c-axis Contains an inorganic compound of 7 to 15 angstroms. From the viewpoint of expressing the effects of the present invention, an inorganic compound having at least two lattice constants of 7 to 15 angstroms in the a-axis, b-axis, and c-axis is preferable, and an inorganic compound having three lattice constants of 7 to 15 angstroms is preferable. Further preferred. Moreover, from the viewpoint of expressing the effects of the present invention, the crystal system is preferably a hexagonal system or a cubic system, and more preferably a cubic system. The lattice constant is preferably 8 to 13 angstroms, more preferably 8 to 10 angstroms, further preferably 8.4 to 9.4 angstroms, and particularly preferably 8.6 to 9.1 angstroms.

  Further, the difference between the lattice constant of the polyester resin in the fiber axis direction and at least one lattice constant of the a-axis, b-axis, and c-axis of the additive of the present invention is preferably 6 angstroms or less, more preferably 3 angstroms or less. More preferably, it is 1 angstrom or less.

  The additive of the present invention is not particularly limited, but is preferably an inorganic compound containing no heavy metal, rare earth metal, etc. from the viewpoint of cost and safety, for example, H, C, N, O, Na, Mg, An inorganic compound composed of any element of Al, Si, P, K, Ca, Ti, Fe, Zn, and Zr is more preferable. For example, sodalite, magnesium aluminate (spinel), zinc titanate, hydroxyapatite, fluoroapatite, magnesium silicate (enstatite), magnesium aluminate (garnite), α-magnesium aluminosilicate (Indialite), β-magnesium alumino Examples thereof include silicate (cordierite), sodium aluminosilicate (nepheline), calcium hydrogen phosphate, α-calcium phosphate, zirconium phosphate, zirconium oxynitride, and sodalite is preferable from the viewpoint of transparency.

  Although the additive of the present invention depends on the blending amount, a weak alkali to neutral one is preferable from the viewpoint of suppressing hydrolysis of the resin. When expressed in terms of pH (25 ° C.) of a 1 wt% aqueous dispersion, it is preferably 4 to 11, more preferably 5.5 to 10.5, and even more preferably 6.0 to 10.2.

The additive of the present invention preferably has a large oil absorption capacity and specific surface area from the viewpoint of expressing the effects of the present invention. The BET specific surface area is preferably at least 1 m ² / g, more preferably at least ^{10m 2 / g, 100m 2 /} g or more, and particularly preferably equal to or greater than 150m ² / g. The oil absorption capacity is preferably 50 mL / 100 g or more, and more preferably 100 mL / 100 g or more. When the oil absorption capacity and specific surface area are large, the resin dispersibility becomes good, the non-uniform formation field of the crystal nuclei of the polyester resin increases, and a large amount of fine crystal nuclei can be generated. It is considered that the improvement of property is brought about and it is preferable.

  The content of the inorganic compound according to the present invention in the additive of the present invention is preferably 50% by weight or more, more preferably 60% by weight or more, and still more preferably from the viewpoint of achieving the object of the present invention. Is 70% by weight or more.

  The additive of the present invention preferably contains an organic compound from the viewpoint of dispersibility in the resin. The type of the organic compound is not particularly limited, but an organic compound that can interact with an inorganic compound in a covalent bond, ionic bond, or hydrogen bond is preferable. For example, the organic compound is covalently bonded with a silane coupling agent or the like. Examples thereof include organic compounds that can interact with inorganic compounds, organic compounds having an anionic functional group such as phosphoric acid, carboxylic acid, and sulfonic acid, and organic compounds having a cationic functional group such as quaternary ammonium. The content of the organic compound in the additive of the present invention is not particularly limited, but is preferably 1 to 50% by weight, and 3 to 40% by weight from the viewpoint of expressing the cost, safety, and the effect of the present invention. More preferred is 10 to 30% by weight.

The additive of the present invention is suitably used as a crystal nucleating agent for polyester resins, and may contain an existing crystal nucleating agent in addition to the inorganic compound and the organic compound capable of interacting with the inorganic compound.
Examples of the existing crystal nucleating agent include inorganic particles such as silica and talc, and sorbitol derivatives such as bisbenzylidene sorbitol.

  The additive of the present invention is suitably used as an additive for polylactic acid resin from the viewpoint of excellent transparency retention in addition to the effects of the present invention.

[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 from 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, 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 has a biodegradability based on JIS K6953 (ISO 14855) “Aerobic and ultimate biodegradability and disintegration test under controlled aerobic compost conditions”. The polyester resin which has is preferable.

  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 Product name Nature Works; manufactured by Daicel Chemical Industries, Ltd., product name Cell Green; manufactured by Mitsubishi Chemical Corporation, product name GS-Pla, and the like.

  Among these, a polylactic acid resin (for example, Mitsui Chemical Co., Ltd., 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 preferred, and orientation crystallization is preferred by stretching. Examples of the crystalline biodegradable resin include Laissia H-100, H-400, and H-440 manufactured by Mitsui Chemicals.

[Plasticizer]
The polyester resin composition of the present invention preferably further contains a plasticizer from the viewpoint of imparting flexibility. The plasticizer used in the present invention is not particularly limited, and examples thereof include those shown in the following (1) to (7) in addition to the plasticizer used in general polyester resins.
(1) Esters of the following components (a) and (b) (a) General formula (I)

(In the formula, X ¹ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 22 carbon atoms, an alkenyl group, an alkoxy group, or a halogen atom, and d and e are each an integer of 1 or more, and d + e = 5. f represents an integer of 0 to 3. The d X ¹ may be the same or different.
Hydroxy aromatic carboxylic acid represented by the formula, hydroxy condensed polycyclic aromatic carboxylic acid having at least one hydroxyl group and carboxyl group in the molecule, hydroxy alicyclic carboxylic acid, anhydride of these carboxylic acids or carbon number At least one selected from 1 to 3 lower alkyl esters.
(B) Hydroxy compounds selected from aliphatic alcohols, alicyclic alcohols, aromatic alcohols, phenols and alkylphenols, or alkylene oxide adducts of these hydroxy compounds (alkylene group having 2 to 4 carbon atoms, alkylene oxide average addition mole) At least one selected from a number greater than 0 and 30 or less.
(2) Ester of the following component (c) and component (d) (c) At least one selected from alkylene oxide adducts of a polyhydric alcohol having 3 or more carbon atoms and having 3 or more hydroxyl groups in one molecule.
(D) At least one selected from linear or branched fatty acids having 2 to 12 carbon atoms or lower alkyl esters having 1 to 3 carbon atoms.
(3) A cyclic acetal obtained by subjecting the following component (e) and component (f) to an acetalization reaction or a transacetalization reaction.
(E) At least one of trihydric or higher polyhydric alcohols.
(F) At least one selected from the group consisting of a carbonyl compound represented by the general formula (II) and an acetal obtained from the carbonyl compound and a lower alcohol having 1 to 6 carbon atoms.

Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom or a linear, branched or cyclic alkyl group having ¹ to 21 carbon atoms, and R ¹ and R ² together represent 2 to 2 carbon atoms. 24 alkylene groups may be formed.)
(4) A compound represented by the general formula (III).

R ³ O (AO) _n R ⁴ (III)
[Wherein R ³ is a linear or branched alkyl group having 1 to 15 carbon atoms, an alkenyl group, or an alkylphenyl group having 7 to 18 carbon atoms, and R ⁴ is an acyl group having 2 to 15 carbon atoms or an alkyl group. or an alkenyl group, and the total number of carbon atoms in R ³ and R ⁴ is 4 to 18. A is an alkylene group having 2 to 4 carbon atoms, n is a number of 1 to 20 indicating the average number of added moles of alkylene oxide, and n A may be the same or different. ]
(5) Trivalent or higher aliphatic polyvalent carboxylic acid, trivalent or higher aromatic polyvalent carboxylic acid, condensed polycyclic aromatic carboxylic acid, and alicyclic carboxylic acid, or anhydrides thereof or carbon thereof An ester of at least one acid component selected from a lower alkyl ester of 1 to 3 and at least one alcohol component selected from an alkylene oxide adduct of a monovalent or divalent alcohol.
(6) A compound represented by the general formula (IV).

B- [O (EO) _p -R ⁵ ] ₂ (IV)
(In the formula, B represents a residue obtained by removing two hydroxyl groups from a linear or branched dihydric alcohol having 2 to 8 carbon atoms, and R ⁵ represents a linear or branched acyl group having 2 to 6 carbon atoms. And two R ^{5 s} may be the same or different, EO represents an oxyethylene group, p represents the average number of moles of ethylene oxide added, and 3 ≦ 2p ≦ 20.)
(7) A compound represented by formula (V).

(In the formula, R ⁶ represents a linear or branched alkyl group having 1 to 18 carbon atoms, and COR ⁸ and COR ⁹ each independently represents a linear or branched acyl group having 2 to 18 carbon atoms. , R ⁷ represents an alkylene group having 2 to 3 carbon atoms, and q + r R ^{7 s} may be the same or different, and q and r are numbers representing the average number of moles added of the oxyalkylene group, and 0 ≦ q ≦ 50, 0 ≦ r ≦ 50, and 0 ≦ q + r ≦ 50.)
Among these plasticizers, from the viewpoint of compatibility, 2-ethylhexanol p-hydroxybenzoic acid monoester, polyoxyethylene 6 mol (hereinafter referred to as POE (6)) glycerin triacetate, diglycerin cyclic acetal, POE (4 ) Methanol caprylate, polyethylene glycol 300 diacetate, 1,3,6-hexanetricarboxylic acid POE (2) butyl ether triester, POE (3) pentyl glyceryl ether diacetate and the like, and the biodegradability of the plasticizer itself From the viewpoint, 2-ethylhexanol p-hydroxybenzoic acid monoester, POE (4) methanol caprylate, polyethylene glycol 300 diacetate, POE (3) pentylglyceryl ether diacetate and the like are particularly preferable.

[Polyester resin composition]
The polyester resin composition of the present invention contains the additive of the present invention and a polyester resin, and preferably further contains a plasticizer. The content of the additive of the present invention in the polyester resin composition is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 100 parts by weight of the polyester resin from the viewpoint of expressing the effects of the present invention. ˜2 parts by weight, particularly preferably 0.5 to 1.5 parts by weight. The content of the plasticizer is preferably 1 to 70 parts by weight, more preferably 3 to 50 parts by weight, and particularly preferably 5 to 45 parts by weight with respect to 100 parts by weight of the polyester resin from the viewpoint of flexibility and bleed resistance. Part.

  Since the polyester resin composition of the present invention varies depending on the type of the polyester resin and the like, it cannot be determined unconditionally, but from the viewpoint of manifesting the effects of the present invention, the cold crystallization temperature (Tcc) measured by the following method Is preferably 70 ° C. or lower, more preferably 66 ° C. or lower. There is a clear correlation between the cold crystallization temperature (Tcc) and the crystallization speed, and the lower the cold crystallization temperature (Tcc), the remarkably improved the crystallization speed of the composition. Improvement in temperature sensitivity and heat resistance can be achieved, and further, the crystal can be made finer. Therefore, in the case of a transparent biodegradable resin such as polylactic acid, excellent transparency can be maintained.

<Cold crystallization temperature (Tcc)>
100 parts by weight of polyester resin, 15 parts by weight of polyoxyethylene (ethylene oxide average added mole number 6) glycerin triacetate (hereinafter abbreviated as POE (6) glycerin triacetate) and 1 part by weight of a crystal nucleating agent as a plasticizer A polyester resin composition obtained by mixing at a melting point (Tm) or higher and cooling it to an amorphous state (that is, conditions under which the crystallinity measured by wide-angle X-ray diffractometry is 1% or less) The cold crystallization peak temperature when measured with a differential scanning calorimeter at a temperature rise condition of 8 ° C./min from is defined as a cold crystallization temperature (Tcc).

  The polyester resin composition of the present invention can contain other components such as a lubricant in addition to the additive and plasticizer of the present invention. 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 polyester resin 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 difficult component, as components other than those described above. A flame retardant etc. can be contained in the range which does not prevent achievement of the objective of this invention.

  Since the polyester resin composition of the present invention has good processability and can be processed at a low temperature such as 130 to 200 ° C., there is also an advantage that the plasticizer is hardly decomposed. It can be used for various purposes.

  As a method for producing the polyester resin composition of the present invention, for example, a step of mixing a polyester resin, an additive of the present invention, and a plasticizer as necessary, at a melting point (Tm) or higher of the polyester resin, and a step of mixing And a step of heat-treating in a temperature range from the glass transition temperature (Tg) of the polyester resin composition obtained by cooling to less than Tm.

  Specific examples of the mixing step in the method for producing the polyester resin composition of the present invention can be carried out by an ordinary method. For example, while the polyester resin is melted using an extruder or the like, the additive of the present invention is used. And a method of mixing a plasticizer. From the viewpoint of the dispersibility of the additive and plasticizer of the present invention, the temperature of the mixing step is not less than the melting point (Tm) of the polyester resin, preferably Tm to Tm + 100 ° C., more preferably Tm to Tm + 50 ° C. is there. For example, when the polyester resin is polylactic acid, the temperature is preferably 170 to 240 ° C, more preferably 170 to 220 ° C.

  Specific examples of the heat-treating step in the method for producing the composition of the present invention can be performed by a usual method, and examples thereof include a method of heat-treating a polyester resin composition extruded by an extruder or the like. The temperature of the heat treatment step is less than Tm from the glass transition temperature (Tg) of the polyester resin composition, preferably Tg to Tg + 100 ° C., more preferably Tg to Tg + 50 ° C., from the viewpoint of improving the crystallization speed. . For example, in the case of a polyester resin composition in which the polyester resin is polylactic acid, 40 to 140 ° C is preferable, 50 to 120 ° C is more preferable, and 60 to 100 ° C is particularly preferable.

  In addition, melting | fusing point (Tm) of a polyester resin is a value calculated | required from the crystal melting endothermic peak temperature by the temperature rising method of the differential scanning calorimetry (DSC) based on JIS-K7121. Further, the glass transition temperature (Tg) of the polyester resin composition is a value obtained from the peak temperature of the loss elastic modulus (E ″) in the dynamic viscoelasticity measurement.

Production Example 1: Synthesis of organically modified sodalite Sodium hydroxide (Sumitomo) in a mixed solution of 0.15 g of sodium hydroxide (manufactured by Wako Pure Chemical Industries), 323 g of 25% tetramethylammonium hydroxide aqueous solution (manufactured by Wako Pure Chemical Industries), and 32 g of water 6.0 g of chemical, NAP-120, Al ₂ O ₃ = 53.8%, Na ₂ O = 40.1%) was added and stirred at room temperature for 2 hours to obtain a colorless and transparent aqueous solution of aluminate. It was. The aluminate aqueous solution was added dropwise to 253 g of an aqueous silica colloid (Nissan Chemical, Snowtex S, SiO ₂ = 30%, Na ₂ O = 0.4%) aqueous solution at room temperature with stirring over 15 minutes. Stir for 63 hours. After 400 g of the obtained cloudy water slurry was centrifuged (20000 r / min, 2 hours), the supernatant colorless and transparent aqueous solution was removed by decantation. Water was added to the resulting colorless precipitated gel and ultrasonic irradiation was performed to obtain a uniform white colloidal solution (pH 11.9). To this colloid solution, 6.0 g of a cation exchange resin (Amberlite IR120BH (H ⁺ type), manufactured by Rohm & Haas Co., Ltd.) was added with stirring at room temperature. After stirring for 10 minutes, the white colloid solution (pH 9. 9) was obtained. This white colloid solution was freeze-dried to obtain a white organically modified sodalite powder. As a result of composition analysis (Na, Si, Al: ZSX100E manufactured by Rigaku Denki Co., Ltd., C, H, N: 2400II manufactured by Perkin Elmer), the anhydrous oxide equivalent composition of the organically modified sodalite powder was 1.3 [( _{CH 3) 4 N] 2 O} : 0.1Na 2 O: 13SiO 2: was Al ₂ O _3. This is called crystal nucleating agent A.

  The physical properties of crystal nucleating agents A to G used in Examples and Comparative Examples were measured by the following methods. The results are shown in Table 1.

<X-ray diffraction>
Using a powder X-ray diffractometer (RINT2500 VPC manufactured by Rigaku Corporation, light source CuKα, tube voltage 40 kV, tube current 120 mA), a scanning angle of 0.01 °, a scanning speed of 10 ° / min, and a vertical divergence range of 2θ = 5 to 70 ° Lattice constants a, b, and c were determined by measuring at room temperature under conditions of a limiting slit of 10 mm, a diverging slit of 1 °, a light receiving slit of 0.3 mm, and a scattering slit automatically.

<PH of 1% by weight aqueous dispersion>
1 g of a sample was added to 99 g of ion-exchanged water (25 ° C.), and the pH of the slurry after stirring for 2 minutes was measured at 25 ° C. using a pH electrode (9621-10D manufactured by Horiba, Ltd.). The obtained value was defined as the pH of the 1 wt% aqueous dispersion.

<Oil absorption capacity>
It was measured according to the oil absorption measurement method of JIS K6220.

<BET specific surface area>
A flow sob (2300 manufactured by Shimadzu Corporation) was used, the sample was 0.1 g, and a mixed gas of N ₂ / He = 30/70 (volume ratio) was used as the adsorption gas.

<Agglomerated particle size>
Using a laser diffraction / scattering particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.), the particle size distribution after measuring the sample for 1 minute with ultrasonic waves using ion-exchanged water as a dispersion medium was measured, and the obtained median The diameter was defined as an agglomerated particle size.

Production Example 2: Synthesis of Plasticizer A specified amount was charged in an autoclave at a molar ratio of 6 moles of ethylene oxide to 1 mole of concentrated glycerin for cosmetics manufactured by Kao Corporation, and a constant pressure of 0.3 MPa reaction pressure using 1 mole% KOH as a catalyst. After addition, the reaction was carried out at 150 ° C. until the pressure became constant, and then the mixture was cooled to 80 ° C. to obtain an unneutralized catalyst product. Kyoward 600S as an adsorbent for the catalyst was added to this product 8 times the catalyst weight, and an adsorption treatment was performed at 80 ° C. for 1 hour under slightly pressurized nitrogen. Further, no. The adsorbent was filtered with a Nutse pre-coated with Radiolite # 900 on the filter paper of No. 2 to obtain an adduct of 6 mol of glycerin ethylene oxide (hereinafter referred to as POE (6) glycerin).

  This was charged into a four-necked flask, heated to 105 ° C., stirred at 300 rpm, and acetic anhydride was added dropwise at a ratio of 3.6 moles per mole of POE (6) glycerin in about 1 hour. I let you. After dropping, the mixture was aged at 110 ° C. for 2 hours and further aged at 120 ° C. for 1 hour. After aging, unreacted acetic anhydride and by-product acetic acid were topped under reduced pressure and further steamed to obtain POE (6) glycerin triacetate.

Examples 1-5 and Comparative Examples 1-3
100 parts by weight of polylactic acid resin (manufactured by Mitsui Chemicals, LACEA H-400, SP value 21.5, Tm 166 ° C., Tg 62 ° C.) as biodegradable resin, 15 parts by weight of POE (6) glycerin triacetate as plasticizer Part of the composition consisting of the type and amount of the crystal nucleating agent shown in Table 2 was kneaded for 10 minutes in a 180 ° C. lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and thickened with a 180 ° C. press molding machine. A test piece having a thickness of 0.5 mm was prepared. During press molding, the sheet to be molded was cooled in an amorphous state (that is, a condition where the degree of crystallinity measured by wide-angle X-ray diffraction method was 1% or less). The sheet was finely cut, 15 mg was weighed in an aluminum pan, and measured from room temperature to 200 ° C. at a rate of temperature increase of 8 ° C./min using a differential scanning calorimetry (DSC) apparatus. At that time, since an exothermic peak of cold crystallization was observed, the peak temperature was defined as a cold crystallization temperature (Tcc). The results are shown in Table 2. The lower the crystallization temperature, the higher the crystallization speed.

Claims (3)

  50% by weight or more of an inorganic compound having a crystal system of hexagonal system or cubic system as a crystal nucleating agent and having at least one lattice constant of a-axis, b-axis, and c-axis of 8.08 to 9.42 angstroms A polylactic acid resin composition comprising an additive for polylactic acid resin and a polylactic acid resin. Further claim 1 Symbol placement of the polylactic acid resin composition contains a plasticizer. A polylactic acid resin and an inorganic compound having a crystal system of hexagonal system or cubic system as a crystal nucleating agent and at least one lattice constant of a-axis, b-axis, and c-axis being 8.08 to 9.42 angstroms A step of mixing an additive for polylactic acid resin containing 50% by weight or more at a melting point (Tm) or higher of the polylactic acid resin, and a temperature range from the glass transition temperature (Tg) of the polylactic acid resin composition to less than Tm. A method for producing a polylactic acid resin composition comprising a step of heat treatment.