JP5584803B2 - Thermoformed product - Google Patents

Description

  The present invention relates to a thermoformed product comprising a specific polylactic acid resin composition. More specifically, the present invention relates to a thermoformed product excellent in heat resistance and hydrolysis resistance obtained by thermoforming a specific polylactic acid resin.

  In recent years, due to concerns about the depletion of petroleum resources and the problem of an increase in carbon dioxide that causes global warming, biomass resources that have carbon neutrality that does not rely on petroleum as a raw material and that do not increase carbon dioxide even when burned are attracting much attention. It is starting to collect. In the polymer field, biomass plastics produced from biomass resources are actively developed.

  A representative example of biomass plastics is polylactic acid, which has relatively high heat resistance and mechanical properties among biomass plastics, so we are considering expanding its use to extruded products such as films and sheets and thermoformed products using them. (See Patent Document 1), and its practical application has progressed to tableware, packaging materials, miscellaneous goods, etc., and more recently, the possibility as an industrial material has been studied.

  However, because polylactic acid was originally developed as a biodegradable resin, it has the advantage of being decomposed into carbon dioxide and water after disposal in the soil, but has biodegradability. On the other hand, it is disadvantageous in that it is susceptible to hydrolysis. This is a problem that when polylactic acid is developed to industrial materials and the like, durability when exposed to a long-term wet heat environment as a product, that is, hydrolysis resistance is inferior.

  On the other hand, polylactic acid has optical isomers. When poly-L-lactic acid and poly-D-lactic acid, which are polymers of L-lactic acid and D-lactic acid, are mixed, a stereocomplex crystal is formed. Or it is known that it becomes a material which shows higher melting | fusing point than the crystal | crystallization of poly-D-lactic acid alone (refer patent document 2, nonpatent literature 1), this stereocomplex polylactic acid is utilized for an automotive component, utilizing the heat resistance. Attempts have been made to use it for industrial applications such as home appliance parts (see Patent Document 3). Also disclosed is a production method in which poly L-lactic acid and poly D-lactic acid are melt-extruded and mixed to obtain an extruded product (see Patent Document 4). And this stereocomplex polylactic acid is also known to be more excellent in hydrolysis resistance than poly L-lactic acid generally utilized (refer nonpatent literature 2).

  However, when this stereocomplex polylactic acid is produced by an industrially advantageous melt extrusion process and products such as industrial materials are obtained by a processing method such as thermoforming, stereocomplexization is sufficiently advanced. However, if the stereocomplexization is insufficient, the good heat resistance and hydrolysis resistance, which are the characteristics thereof, cannot be exhibited.

  A method of heat-treating a mixture of poly-L-lactic acid and poly-D-lactic acid under a high temperature condition of 260 ° C. to 300 ° C. has also been proposed, but high energy is required and molecular weight due to thermal decomposition of polylactic acid Problems such as deterioration of mechanical properties and coloring may occur (see Patent Document 5).

Japanese Patent Application Laid-Open No. 07-308961 JP 63-24014 A Japanese Patent No. 3583097 JP 09-25400 A JP 2007-191551 A

Macromolecules, 24, 5651 (1991) Polymer, 41, 3621 (2000)

The main problem to be solved by the present invention is to provide a thermoformed product of polylactic acid resin having excellent heat resistance, mechanical properties and the like.
As a result of intensive studies, the present inventors have made it possible to mold under relatively mild conditions by using a specific polylactic acid in which an amide bond is bonded using polyisocyanate, and by thermoforming, The present invention has been completed by finding that a thermoformed product having excellent heat resistance and mechanical properties can be obtained.

That is, the present invention relates to the following (1) to (6).
(1) A polylactic acid resin (component A) having an amide bond obtained by reacting at least a polylactic acid unit containing L-lactic acid as a main component and a polylactic acid unit containing D-lactic acid as a main component with polyisocyanate. Thermoformed product,
Each of the polylactic acid units is obtained by any of the following methods, and a thermoformed product in which the ratio of carboxyl groups in the terminal functional groups exceeds 50%;
(A) A method of directly polycondensing a dicarboxylic acid or an acid anhydride with either lactic acid as a raw material, either in the initial stage of polymerization, in the middle or in the latter stage,
(B) A method of adding an acid anhydride after ring-opening polymerization of L-lactide or D-lactide, which is a lactic acid cyclic dimer, using an initiator.

(2) The polylactic acid unit containing L-lactic acid as a main component is composed of 90 to 100 mol% of L-lactic acid units and 0 to 10 mol% of D-lactic acid units and / or copolymer component units other than lactic acid. A polylactic acid unit,
The polylactic acid unit containing D-lactic acid as a main component is composed of 90 to 100 mol% of D-lactic acid units and 0 to 10 mol% of L-lactic acid units and / or copolymer component units other than lactic acid. Lactic acid unit,
Weight ratio of polylactic acid unit mainly composed of L-lactic acid and polylactic acid unit mainly composed of D-lactic acid in polylactic acid resin (component A) (polylactic acid unit mainly composed of L-lactic acid) / D-lactic acid as a main component) is in the range of 10/90 to 90/10, and the thermoformed product according to (1) above.

(3) The weight average molecular weight of each polylactic acid unit is in the range of 5000 to 100,000,
The thermoformed article as described in (1) or (2) above, wherein the polylactic acid resin (component A) has a weight average molecular weight in the range of 80,000 to 500,000.
(4) The thermoformed product according to any one of (1) to (3), wherein the polyisocyanate is an aliphatic diisocyanate.
(5) The polylactic acid resin (component A) is characterized in that, in a differential scanning calorimeter (DSC) measurement, a ratio of a melting peak at 195 ° C. or higher is 70% or higher among melting peaks in a temperature rising process. The thermoformed product according to any one of (1) to (4).
(6) The terminal blocker (component B) is contained in an amount of 0.01 to 5 parts by weight per 100 parts by weight of the polylactic acid resin (component A), according to any one of the above (1) to (5) Thermoformed product.

The molded article of the present invention can be obtained by thermoforming under relatively mild conditions using a polylactic acid resin capable of forming a stereocomplex at a high rate under relatively mild conditions. It has mechanical properties and hydrolysis resistance, and in addition, the environmental load is reduced.
The molded product of the present invention having the above-described features is useful for various uses such as packaging containers, various electronic / electrical equipment, OA equipment, vehicle parts, machine parts, other agricultural materials, fishing materials, transport containers, playground equipment, and miscellaneous goods. And the industrial effects that it plays are exceptional.

  Hereinafter, the polylactic acid of the present invention and other components, their blending ratio, preparation method and the like will be specifically described sequentially.

<About polylactic acid resin (component A)>
The polylactic acid resin of component A is a polylactic acid having an amide bond obtained by reacting a resin composition containing at least polylactic acid mainly composed of L-lactic acid and polylactic acid mainly composed of D-lactic acid with polyisocyanate. Resin. Having an amide bond is preferable from the viewpoint of heat resistance and crystallinity improvement.

  Here, the “main component” means that 60% by weight or more, more preferably 90% by weight or more of the structural unit specified in the polymer is contained.

The weight average molecular weight of the polylactic acid resin (component A) is preferably 80,000 to 500,000. More preferably, it is 100,000-300,000, More preferably, it is 100,000-250,000, and 100,000-200,000 are especially preferable from the point of a moldability and mechanical strength. The weight average molecular weight is a weight average molecular weight value in terms of standard polystyrene as measured by gel permeation chromatography (GPC) using chloroform as an eluent.
The polylactic acid resin (component A) in the resin composition constituting the thermoformed product of the present invention is polylactic acid having an L-lactic acid unit and a D-lactic acid unit as basic components, represented by the following formula (i):

（ここでnは１から２０００までの自然数をさす。）

(Where n is a natural number from 1 to 2000)

The polylactic acid mainly composed of L-lactic acid is preferably a-1 component or a-2 component, and the polylactic acid mainly composed of D-lactic acid is preferably b-1 component or b-2 component.
The a-1 component is polylactic acid composed of 90 to 100 mol% of L-lactic acid units and 0 to 10 mol% of D-lactic acid units and / or copolymerized component units other than lactic acid.
The a-2 component is a polylactic acid unit composed of 90 to 99 mol% of L-lactic acid units and 1 to 10 mol% of D-lactic acid units and / or copolymerized component units other than lactic acid.
The component b-1 is a polylactic acid unit composed of 90 to 100 mol% of D-lactic acid units and 0 to 10 mol% of L-lactic acid units and / or copolymerization component units other than lactic acid.
The b-2 component is a polylactic acid unit composed of 90 to 99 mol% of D-lactic acid units and 1 to 10 mol% of copolymer component units other than L-lactic acid units and / or lactic acid.

  The polylactic acid resin (component A) comprises an a-1 component and a b-1 component, and the weight ratio of the a-1 component to the b-1 component (a-1 component / b-1 component) is 10/90 to Polylactic acid in the range of 90/10, more preferably 30/70 to 70/30 is preferred.

Further, the polylactic acid resin (component A) comprises (1) a-1 component and b-2 component, and the weight ratio of the a-1 component and b-2 component (a-1 component / b-2 component). Is in the range of 10/90 to 90/10, more preferably in the range of 30/70 to 70/30, or (2) consists of b-1 component and a-2 component, b-1 component and a-2 component The polylactic acid having a weight ratio (b-1 component / a-2 component) of 10/90 to 90/10, more preferably 30/70 to 70/30 is preferable.
A particularly preferred polylactic acid resin (component A) comprises an a-2 component and a b-2 component, and the weight ratio of the a-2 component to the b-2 component (a-2 component / b-2 component) is 10 / Polylactic acid in the range of 90 to 90/10, more preferably 30/70 to 70/30.

  In the polylactic acid resin (component A), polylactic acid units mainly composed of L-lactic acid units (a-1 to a-2 components) and polylactic acid units mainly composed of D-lactic acid units (b-1 to b-2) The weight ratio of component) is 10/90 to 90/10, but in order to form more stereocomplexes, it is preferably 25/75 to 75/25, more preferably 40/60 to 60/40. If the weight ratio of one polymer is less than 10% by weight or exceeds 90% by weight, homocrystallization is prioritized and it may be difficult to form a stereo complex.

  The copolymer component unit other than lactic acid in the polylactic acid unit in the polylactic acid resin (component A) includes dicarboxylic acid, polyhydric alcohol, polyvalent amine, hydroxycarboxylic acid having two or more functional groups capable of forming an ester bond. Units derived from lactone, etc. and units derived from various polyesters, various polyethers, various polyamides, various polycarbonates, etc. composed of these various components can be used alone or in combination.

  Examples of the dicarboxylic acid include succinic acid, phthalic acid, maleic acid, tetrabromophthalic acid, tetrahydrophthalic acid, and dodecyl succinic acid. Polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, tri Examples thereof include polyhydric alcohols such as pentaerythritol, sorbitol, poly (vinyl alcohol), poly (hydroxyethyl methacrylate), and poly (hydroxypropyl methacrylate). Examples of the polyvalent amine include ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexyleneamine, heptylenediamine, diethylenetriamine, melamine and the like. As hydroxycarboxylic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid , 2-hydroxycaproic acid, 2-cyclohexyl-2-hydroxyacetic acid, mandelic acid and the like. Examples of the lactone include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, and the like.

  The weight average molecular weight of each polylactic acid unit (components a-1 to a-2 and components b-1 to b-2) constituting the polylactic acid resin (component A) is preferably 5,000 to 100,000. More preferably, 10000-70000 and 10000-50000 are particularly preferable. The weight average molecular weight is a weight average molecular weight value in terms of standard polystyrene as measured by gel permeation chromatography (GPC) using chloroform as an eluent.

  Moreover, each polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) constituting the polylactic acid resin (component A) has a carboxyl group ratio exceeding 50% in the terminal functional group. Is preferred. More preferably, the ratio of the carboxyl group in the terminal functional group is 90% or more, and the ratio of the carboxyl group in the terminal functional group is particularly preferably 95% or more. By increasing the proportion of the carboxyl group, more amide bonds are formed in the production method described later, which is preferable from the viewpoint of heat resistance and crystallinity.

The resin composition containing at least a polylactic acid unit containing L-lactic acid as a main component and a polylactic acid unit containing D-lactic acid as a main component contains other resin component units that react with isocyanate other than the polylactic acid unit. Also good.
Other resin components will be described later.

<Method for producing polylactic acid unit mainly composed of L-lactic acid or D-lactic acid>
Each polylactic acid unit (components a-1 to a-2 and components b-1 to b-2) constituting the polylactic acid resin (component A) can be produced by any known polylactic acid polymerization method. For example, it can be produced by ring-opening polymerization of lactide, dehydration condensation of lactic acid, and a method combining these with solid phase polymerization.

(Direct polycondensation method)
A specific example of preparing a polylactic acid unit containing L-lactic acid or D-lactic acid as a main component by a direct polycondensation method is to heat the raw material L-lactic acid or D-lactic acid in an inert gas atmosphere and lower the pressure. Each polylactic acid unit (a-1 to a-2 components) constituting the polylactic acid resin (component A) by performing a polycondensation reaction and finally performing a polycondensation reaction under conditions of a predetermined temperature and pressure. And b-1 to b-2 components). At this time, the main component is L-lactic acid in which the proportion of the carboxyl group in the terminal functional group exceeds 50% by adding polycarboxylic acid or acid anhydride or the like together with lactic acid as a raw material either in the early stage, in the middle or later stage. Polylactic acid units (a-1 to a-2 components) and polylactic acid units (b-1 to b-2 components) mainly composed of D-lactic acid in which the proportion of carboxyl groups in the terminal functional group exceeds 50% Can be prepared. The polycarboxylic acid component is preferably a dicarboxylic acid, and examples of the dicarboxylic acid component include succinic acid, phthalic acid, maleic acid, tetrabromophthalic acid, tetrahydrophthalic acid, trimellitic acid, and dodecyl succinic acid. An acid is particularly preferable from the viewpoint of cost. Examples of the acid anhydride include succinic anhydride, phthalic anhydride, maleic anhydride, tetrabromophthalic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride or dodecyl succinic anhydride, and succinic anhydride is particularly preferable. When the polycarboxylic acid or acid anhydride is added in the latter stage of polymerization, the polylactic acid units (a-1 to a-2 components and b-1) constituting the polylactic acid resin (component A) before addition are used. ˜b-2 component) is 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, and more preferably 0.5 to 5 parts by weight. When the polycarboxylic acid or acid anhydride is added during or later in the polymerization, each polylactic acid unit (a-1 to a-2 component and b-1 to b-) constituting the polylactic acid resin (component A) described later. What is necessary is just to add according to the target molecular weight in 2 components. Specifically, 0.001 to 5 parts by weight is preferable and 0.01 to 3 parts by weight is more preferable with respect to 100 parts by weight of L-lactic acid or D-lactic acid to be used. When the amount of the polycarboxylic acid or acid anhydride added is less than 0.001 part by weight, the molecular weight becomes too large and the polymerization takes a long time. On the other hand, when it exceeds 5 parts by weight, the molecular weight becomes too small and the In some cases, sufficient heat resistance, which is the purpose of the lactic acid resin, cannot be obtained.

  The polycondensation reaction may be performed in the presence of a catalyst for the purpose of shortening the polycondensation time, increasing the reaction rate with the acid anhydride, or shortening the reaction time. Examples of the catalyst include metals of Groups 2, 12, 13, 14, or 15 of the periodic table, or oxides or salts thereof. Specifically, metals such as zinc powder, tin powder, aluminum or magnesium, metal oxides such as antimony oxide, zinc oxide, tin oxide, aluminum oxide, magnesium oxide or titanium oxide, stannous chloride, stannic chloride , Stannous bromide, stannic bromide, antimony fluoride, zinc chloride, magnesium chloride or aluminum chloride, etc., carbonates such as magnesium carbonate or zinc carbonate, tin acetate, tin octoate, tin lactate , Organic carboxylates such as zinc acetate or aluminum acetate, or organic sulfonates such as tin trifluoromethanesulfonate, zinc trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, tin methanesulfonate or tin p-toluenesulfonate Can be given. In addition, organometallic oxides of the above metals such as dibutyltin oxide, metal alkoxides of the above metals such as titanium isopropoxide, alkyl metals of the above metals such as diethyl zinc, ion exchange resins such as dowex or amberlite, or the like And a protonic acid such as sulfuric acid, methanesulfonic acid or p-toluenesulfonic acid, and a tin or zinc metal or a metal compound thereof, which can obtain a high molecular weight polymer at a high polymerization rate, is preferable. Further, metal tin or tin compounds such as tin oxide and tin chloride are particularly preferred from the viewpoint of hue and catalytic activity. The amount of the catalyst added is not particularly limited, but is preferably 0.001 to 2 parts by weight, more preferably 0.001 to 1 part by weight, based on 100 parts by weight of L-lactic acid or D-lactic acid. preferable. When the amount of the catalyst is less than 0.001 part by weight, the effect of shortening the polymerization time is reduced, and when it exceeds 2 parts by weight, the heat of the molecular weight reduction or thermal decomposition during the molding process of the polylactic acid resin in the present invention due to the influence of the catalyst residue. It may impair stability.

(Ring-opening polymerization method)
In order to obtain each polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) constituting the polylactic acid resin (component A), L-lactide, which is the lactic acid cyclic dimer described above, is used. And D-lactide is subjected to ring-opening polymerization using an initiator such as a compound containing two or more hydroxyl groups or amino groups in the molecule, hydroxycarboxylic acid, water and the like. Moreover, the ratio that the terminal functional group of each polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) constituting the polylactic acid resin (component A) is a carboxyl group exceeds 50%. Specific examples of the compound prepared by using an initiator such as L-lactide and D-lactide, which are the above-mentioned lactic acid cyclic dimers, containing two or more hydroxyl groups or amino groups in the molecule, hydroxycarboxylic acid, water and the like. Examples thereof include a method obtained by adding ring-opening polymerization and then adding an acid anhydride. Examples of the compound containing two or more hydroxyl groups or amino groups in the molecule include ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin. , Polymethyl alcohols such as trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, poly (vinyl alcohol), poly (hydroxyethyl methacrylate), poly (hydroxypropyl methacrylate), ethylenediamine, propylenediamine, butylenediamine , Pentylenediamine, hexylenediamine, heptylenediamine, diethylenetriamine, Polyhydric amines such as tromethamine and the like. The addition amount of the initiator is not particularly limited, but is preferably 0.001 to 5 parts by weight with respect to 100 parts by weight of lactide (L-lactide or D-lactide) to be used. Part by weight is more preferred. When the amount of the polymerization initiator is less than 0.001 part by weight, the molecular weight becomes too large. On the other hand, when the amount exceeds 5 parts by weight, the molecular weight becomes too small. In either case, sufficient heat resistance is the purpose of the polylactic acid resin in the present invention. Sexuality may not be obtained.
Examples of the acid anhydride include succinic anhydride, phthalic anhydride, maleic anhydride, tetrabromophthalic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride or dodecyl succinic anhydride, and succinic anhydride is particularly preferable. The addition amount of the acid anhydride is 100 parts by weight of each polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) constituting the polylactic acid resin (component A) before addition. 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, and more preferably 0.5 to 5 parts by weight.

  The ring-opening polymerization may be performed in the presence of a catalyst for the purpose of shortening the polymerization time, increasing the reaction rate with the acid anhydride, or shortening the reaction time. Examples of the catalyst include metals such as tin, zinc, lead, titanium, bismuth, zirconium, germanium, antimony, and aluminum, and derivatives thereof. Derivatives are preferably metal alkoxides, carboxylates, carbonates, oxides and halides. Specific examples include tin chloride, tin octylate, zinc chloride, zinc acetate, lead oxide, lead carbonate, titanium chloride, alkoxytitanium, germanium oxide, and zirconium oxide. Among these, a tin compound is preferable, and tin octylate is particularly preferable. The amount of the catalyst added is not particularly limited, but is preferably 0.001 to 2 parts by weight, more preferably 0.001 to 1 part by weight based on 100 parts by weight of L-lactide or D-lactide used. preferable. When the amount of the catalyst is less than 0.001 part by weight, the effect of shortening the polymerization time is reduced, and when it exceeds 2 parts by weight, the thermal stability such as a decrease in molecular weight or thermal decomposition during molding of the polylactic acid resin in the present invention is impaired. There is.

<About the manufacturing method of polylactic acid resin (component A)>
Polylactic acid resin (A component) having an amide bond obtained by reacting a resin composition containing a polylactic acid unit containing L-lactic acid as a main component and a polylactic acid unit containing D-lactic acid as a main component, and a polyisocyanate The production method comprises a step of reacting at least each polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) constituting the polylactic acid resin (component A) with a polyisocyanate compound. Including. In this reaction, an amide bond is formed by a carboxyl group as a terminal functional group reacting with polyisocyanate. In the above reaction, it is preferable to carry out the reaction using an amidation catalyst. Although the following method is mentioned as a specific example of this process, As long as the objective of this invention is not impaired, it is not limited to this at all.

  First, the polylactic acid unit (components a-1 to a-2) mainly composed of L-lactic acid, the polylactic acid unit (components b-1 to b-2) mainly composed of D-lactic acid, and a solvent. The mixture is mixed, and the mixture is heated to a predetermined temperature under normal pressure and a nitrogen atmosphere. Next, after adding a catalyst to the mixture as necessary, a polyisocyanate compound is further added and reacted at a predetermined temperature. Finally, a polylactic acid resin (component A) can be obtained by decarboxylation of the obtained reaction product. The polyisocyanate compound is preferably a diisocyanate compound.

  In this step, the viscosity increases rapidly with increasing molecular weight of the reactant. Therefore, in addition to the method of reacting while stirring with a solution as described above, the method of extruding the product by kneading and reacting without a solvent using an extruder, particularly a twin-screw kneading extruder, is produced without using a solvent. Post-treatment of the product is simple and effective.

<Polyisocyanate compound>
The polyisocyanate compound used in the step is a compound having two or more isocyanate groups, and is not particularly limited as long as the object of the present invention is not impaired. Examples of the polyisocyanate compound having 3 or more isocyanate groups include triisocyanates such as 1,6,11-undecane triisocyanate and polyisocyanate-substituted compounds such as polyphenylmethane polyisocyanate. The polyisocyanate compound is preferably a diisocyanate compound.

  Diisocyanate compounds include 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, tetramethylene Diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, 1,3- (bisisocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, bis (isocyanatomethyl) bicyclo- [ 2,2,1] -heptane or bis (4-isocyanatocyclohexyl) methane, etc., and more preferred examples include 1,3-xylylene diisocyanate Tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, 1,3- (bisisocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, bis (isocyanatomethyl) bicyclo -[2,2,1] -heptane or bis (4-isocyanatocyclohexyl) methane.

  Among these, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, 1,3- (bisisocyanatomethyl) cyclohexane, bis (isocyanatomethyl) bicyclo- [2,2,1] -It is preferably one compound selected from the group consisting of heptane and bis (4-isocyanatocyclohexyl) methane, preferably an aliphatic diisocyanate compound, and particularly preferably hexamethylene diisocyanate. It is preferable in terms of color tone that the polyisocyanate compound is an aliphatic diisocyanate.

<Addition amount of polyisocyanate>
The addition amount of the polyisocyanate compound is based on the number of moles calculated from the number of all terminal functional groups of the mixture containing at least each of the polylactic acid units (a-1 to a-2 components and b-1 to b-2 components). To decide. The method of calculating | requiring the terminal functional group number of a polylactic acid unit (a-1 to a-2 component and b-1 to b-2 component) calculates by NMR and a carboxylic acid value. NMR and carboxylic acid values are measured by the methods described in the examples described later.

  The amount of the polyisocyanate compound added is the polylactic acid unit (a-1 to a-2 component) containing L-lactic acid as the main component and the polylactic acid unit (b-1 to b-component containing D-lactic acid as the main component). It is preferably 0.8 to 2.0 times mol, more preferably 0.8 to 1.5 times mol, with respect to the number of terminal functional groups of the mixture containing at least two components. It is especially preferable that it is 1.3 times mole. Here, “fold mole” is a unit of a value calculated by “number of moles of terminal functional group / one mole of reference substance”, and “reference substance” indicates an isocyanate group in the polyisocyanate compound.

  When the addition amount of the polyisocyanate compound is less than the lower limit, the addition effect of the polyisocyanate compound is small, and it may be difficult to obtain a high molecular weight polylactic acid resin (component A). On the other hand, if the upper limit is exceeded, the isocyanate may cause side reactions such as a crosslinking reaction, and a gel-like polylactic acid resin (component A) may be generated.

<Amidation catalyst>
In the present invention, the amidation catalyst is given priority to terminal carboxyl groups such as polylactic acid units (a-1 to a-2 components and b-1 to b-2 components) constituting the polylactic acid resin (component A). Specifically, it refers to a catalyst that reacts with the polyisocyanate compound to form an amide bond.

  The amidation catalyst used in the step preferably contains at least one metal selected from the group of metals in Groups 1, 2 and 3 of the periodic table, and is selected from the group of potassium, magnesium, calcium and ytterbium. More preferably, it contains at least one metal, and particularly preferably contains magnesium or calcium. The inclusion of such a metal is preferable in terms of catalytic effect and color tone.

  Examples of the amidation catalyst containing Group 1 metal of the periodic table include organic metal compounds such as organic acid salts, metal alkoxides or metal complexes (acetylacetonate, etc.) of lithium, sodium, potassium, rubidium or cesium; Inorganic metal compounds such as compounds, metal hydroxides, carbonates, phosphates, sulfates, nitrates, chlorides or fluorides, and as amidation catalysts containing Group 2 metals of the above periodic table, Organometallic compounds such as organic acid salts, metal alkoxides or metal complexes (such as acetylacetonate) of beryllium, magnesium, calcium, strontium or barium; metal oxides, metal hydroxides, carbonates, phosphates, sulfates Inorganic metal compounds such as nitrates, chlorides and fluorides. Furthermore, as the amidation catalyst containing the Group 3 metal of the periodic table, organometallic compounds such as scandium, ytterbium, yttrium or other rare earth organic acid salts, metal alkoxides or metal complexes (acetylacetonate, etc.) Inorganic metal compounds such as metal oxides, metal hydroxides, carbonates, phosphates, sulfates, nitrates, chlorides or fluorides; These may be used alone or in combination. Among these metal compound catalysts, bis (acetylacetonato) magnesium, magnesium stearate, calcium stearate, magnesium chloride, ytterbium triflate, etc. are preferable, and magnesium compounds, particularly bis (acetylacetonato) magnesium, magnesium stearate. Is preferred. Two or more of these catalysts can be used in combination.

  The amount of the amidation catalyst added is such that polylactic acid units (a-1 to a-2 components) mainly composed of L-lactic acid and polylactic acid units (b-1 to b-2) mainly composed of D-lactic acid. It is 0.01 to 2 parts by weight, preferably 0.01 to 1 part by weight, and more preferably 0.01 to 0.5 part by weight with respect to 100 parts by weight of the mixture containing at least the component.

  At least the polylactic acid unit (a-1 to a-2 component) having L-lactic acid as a main component and the polylactic acid unit (b-1 to b-2 component) having D-lactic acid as a main component in the present invention. The mixture may contain hydroxyl groups. In that case, the hydroxy moiety reacts with the polyisocyanate compound to form a urethane bond.

  Examples of the catalyst for forming such a urethane bond include dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, Titanium series such as tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate, dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, olein Lead such as lead acid, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, iron 2-ethylhexanoate, iron acetylacetate Iron-based, cobalt-benzoic acid, cobalt 2-ethylhexanoic acid cobalt, zinc naphthenate, zinc 2-ethylhexanoic acid zinc, naphthenic acid zirconium, triethylamine, triethylenediamine, N, N- Examples thereof include dimethylbenzylamine, N-methylmorpholine, diazabicycloundecene (DBU) and the like. The addition amount of the catalyst for forming the urethane bond is 0.01-2 parts by weight, preferably 0.01-1 part by weight, more preferably 0.01-0. 5 parts by weight.

<Copolymerization component>
As described above, in the polylactic acid resin (component A), polylactic acid units (a-1 to a-2 components) containing L-lactic acid as a main component and polylactic acid units (b-1 to b) containing D-lactic acid as main components. In addition to (b-2 component), a copolymer component may be included.

  The copolymer component is not particularly limited as long as it does not impair the object of the present invention, and can be used according to the object of improving physical properties. For example, polyhydroxycarboxylic acid other than polylactic acid, polyester, polyamide, polycarbonate and the like can be used.

  The content of the copolymer component is not particularly limited as long as it does not impair the object of the present invention, and polylactic acid units (a-1 to a-2 components) mainly composed of L-lactic acid and 0 to 40 parts by weight, preferably 5 to 20 parts by weight, more preferably 5 to 10 parts by weight with respect to 100 parts by weight of a mixture of polylactic acid units (components b-1 to b-2) mainly composed of D-lactic acid. It is preferable to use parts.

  Specific examples of the polyhydroxycarboxylic acid include polyglycolic acid, poly (3-hydroxybutyric acid), poly (4-hydroxybutyric acid), poly (2-hydroxy-n-butyric acid), poly (2-hydroxy-3,3- Dimethylbutyric acid), poly (2-hydroxy-3-methylbutyric acid), poly (2-methyllactic acid), poly (2-hydroxycaproic acid), poly (2-hydroxy-3-methylbutyric acid), poly (2-cyclohexyl) -2-hydroxyacetic acid), poly (mandelic acid) or polycaprolactone, or a copolymer or mixture thereof.

  Polyester is a polyester whose main component is represented by a repeating unit consisting of a glycol component and a dicarboxylic acid component, but it may be a copolymer of three or more components, including a copolymer other than a glycol component or a dicarboxylic acid component. May be. Examples of the glycol component include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neo Examples thereof include glycol compounds such as pentyl glycol, glycerin, pentaerythritol, bisphenol A, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and these can be used alone or in combination of two or more.

  Dicarboxylic acid components include succinic acid, oxalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, bis ( p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, dicarboxylic acid such as 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, and dimethyl ester thereof. These can be used alone or in combination of two or more.

  In addition, other copolymer components may include hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and hydroxybenzoic acid.

  Typical polyesters include polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene isophthalate, polybutylene isophthalate, polypropylene isophthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate, poly Butylene terephthalate, bisphenol A terephthalate, bisphenol A isophthalate, polycyclohexanedimethylene terephthalate, polycyclohexane dimethylene isophthalate, polyethylene sulfoisophthalate, polyethylene sulfoisophthalate, polybutylene sulfoisophthalate, polypropylene sulfoisophthalate, polybutylene sebate Polypropylene sebate, polyethylene sebate, polyethylene glycol, polyethylene glycol, polyethylene glycol, poly-ε-caprolactone, polyethylene oxalate, polypropylene oxalate, polybutylene oxalate, polyneopentyl glycol oxalate, polyethylene succinate, polypropylene succinate , Polybutylene succinate, polybutylene adipate, polypropylene adipate, polyethylene adipate, and the like. Polyamide is a polymer or copolymer mainly composed of amino acids, lactams or diamines and dicarboxylic acids. Examples of amino acids include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid. Examples of lactam include ε-caprolactam and ω-laurolactam.

  Examples of the diamine include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, 5-methylnonamethylene diamine, 2,4-dimethyloctamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 3, 8-bis (aminomethyl) tricyclodecane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) ) Piperazine, Ami Such as ethyl piperazine, and the like.

  Dicarboxylic acids include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, diglycolic acid and the like. Specific examples of the raw material include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and p-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, and tetramethylenediamine. , Hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methyl Nonamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5 -Trimethylcyclohex Fats such as sun, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine , Alicyclic, aromatic diamines, and succinic acid, adipic acid, peric acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5 -Aliphatic, alicyclic and aromatic dicarboxylic acids such as methyl isophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and the like. Homopolymers or copolymers derived from can be used .

  Specific examples of polyamides include polycaproamide, polyhexamethylene adipamide, polytetramethylene adipamide, polyhexamethylene sebamide, polyhexamethylene dodecane, polyundecanamide, polydodecanamide, polycaproamide / Polyhexamethylene terephthalamide copolymer, polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer, polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer, polyhexamethylene adipamide / polyhexamethylene isophthalamide / polycapro Amide copolymer, polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer, polyhexamethylene terephthalamide / polydodecanamide copolymer, Li hexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer, poly-xylylene adipamide, poly hexamethylene terephthalamide / poly-2-methyl pentamethylene terephthalamide copolymers.

  Polycarbonate is a resin having a carbonate bond, and is a polymer or copolymer obtained by reacting an aromatic hydroxy compound or a small amount of a polyhydroxy compound with a carbonate precursor. As aromatic hydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2,2-bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) Propane, 2,2-bis (hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, hydroquinone, resorcinol, 4,6-dimethyl-2,4,6 -Tri (4-hydroxyphenyl) heptene, 2,4,6-dimethyl-2,4,6-tri (4 Hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene, 1,3,5-tri (4-hydroxyphenyl) benzene, 1,1,1-tri (4 -Hydroxyphenyl) ethane, 3,3-bis (4-hydroxyaryl) oxindole, 5-chloro-3,3-bis (4-hydroxyaryl) oxindole, 5,7-dichloro-3,3-bis ( 4-hydroxyaryl) oxindole, 5-bromo-3,3-bis (4-hydroxyaryl) oxindole, etc. may be mentioned, and these may be used alone or in combination of two or more.

  As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate and the like.

  The terminal functional group of the copolymer component is not particularly limited, but is preferably one converted to a carboxyl group.

  The polylactic acid resin (component A) of the present invention is a ratio of the melting peak of 195 ° C. or higher in the melting peak derived from polylactic acid in the temperature rising process of differential scanning calorimetry (DSC) measurement at the stage of pellets before molding. Is preferably 70% or more, preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. The larger the ratio of the melting peak at 195 ° C. or higher, the easier it is to manufacture a thermoformed product having a higher stereo complex ratio.

<About B component>
In the resin composition constituting the thermoformed product of the present invention, when a terminal blocking agent which is a B component is further blended, a molded product with further improved hydrolysis resistance can be obtained.

  The end-capping agent (component B) shows a function of blocking by reacting with part or all of the carboxyl group ends of the polylactic acid resin (component A) in the resin composition constituting the thermoformed product of the present invention. Examples thereof include condensation reaction type compounds such as aliphatic alcohols and amide compounds, and addition reaction type compounds such as carbodiimide compounds, epoxy compounds, oxazoline compounds, oxazine compounds, and aziridine compounds.

  Examples of the monocarbodiimide compound contained in the carbodiimide compound include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide and the like. Of these, dicyclohexylcarbodiimide or diisopropylcarbodiimide is preferred from the viewpoint of easy industrial availability.

  In addition, as the polycarbodiimide compound contained in the carbodiimide compound, those produced by various methods can be used. Basically, conventional polycarbodiimide production methods (US Pat. No. 2,941,956, No. 47-33279, J.0rg.Chem.28, 2069-2075 (1963), Chemical Review 981, Vol.81 No.4, p619-621) can be used.

  Examples of the organic diisocyanate that is a synthetic raw material in the production of the polycarbodiimide compound include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures thereof. Specifically, 1,5-naphthalene diisocyanate. 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2, , 4-tolylene diisocyanate and 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophoro Illustrate diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl isocyanate, 1,3,5-triisopropylbenzene-2,4-diisocyanate, etc. Can do.

  Moreover, in the case of the said polycarbodiimide compound, it can also control to a suitable polymerization degree using the compound which reacts with the terminal isocyanate of polycarbodiimide compound, such as monoisocyanate.

  Examples of the monoisocyanate for sealing the end of such a polycarbodiimide compound and controlling the degree of polymerization thereof include phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like. be able to.

  Examples of the epoxy compound include, for example, N-glycidylphthalimide, N-glycidyl-4-methylphthalimide, N-glycidyl-4,5-dimethylphthalimide, N-glycidyl-3-methylphthalimide, and N-glycidyl-3,6. -Dimethylphthalimide, N-glycidyl-4-ethoxyphthalimide, N-glycidyl-4-chlorophthalimide, N-glycidyl-4,5-dichlorophthalimide, N-glycidyl-3,4,5,6-tetrabromophthalimide, N-glycidyl-4-n-butyl-5-bromophthalimide, N-glycidyl succinimide, N-glycidyl hexahydrophthalimide, N-glycidyl-1,2,3,6-tetrahydrophthalimide, N-glycidyl maleimide, N -Glycidyl-α, β-dimethyl Succinimide, N-glycidyl-α-ethylsuccinimide, N-glycidyl-α-propylsuccinimide, N-glycidylbenzamide, N-glycidyl-p-methylbenzamide, N-glycidylnaphthamide, N-glycidylsteramide, N- Methyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide, N-ethyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide, N-phenyl-4,5-epoxycyclohexane-1, -Dicarboxylic imide, N-naphthyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide, N-tolyl-3-methyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide, orthophenylphenyl Glycidyl ether, 2-methyloctyl glycidyl Ether, phenyl glycidyl ether, 3- (2-xenyloxy) -1,2-epoxypropane, allyl glycidyl ether, butyl glycidyl ether, lauryl glycidyl ether, benzyl glycidyl ether, cyclohexyl glycidyl ether, α-cresyl glycidyl ether, p- t-Butylphenyl glycidyl ether, glycidyl methacrylate methacrylate, ethylene oxide, propylene oxide, styrene oxide, octylene oxide, hydroquinone diglycidyl ether, resorcin diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A- Diglycidyl ether and the like, and further, terephthalic acid diglycidyl ester, tetrahydrophthalic acid diglycol Succinimidyl ester, hexahydrophthalic acid diglycidyl ester, phthalic acid dimethyl diglycidyl ester, phenylene glycidyl ether, ethylene diglycidyl ether, trimethylene diglycidyl ether, tetramethylene diglycidyl ether, hexamethylene diglycidyl ether. One or more compounds selected from these epoxy compounds may be arbitrarily selected to block the carboxyl terminal of the polylactic acid unit, but in terms of reactivity, ethylene oxide, propylene oxide, phenyl glycidyl ether, ortho Preferred are phenylphenyl glycidyl ether, pt-butylphenyl glycidyl ether, N-glycidyl phthalimide, hydroquinone diglycidyl ether, resorcin diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A-diglycidyl ether, and the like. .

  Examples of oxazoline compounds include, for example, 2-methoxy-2-oxazoline, 2-ethoxy-2-oxazoline, 2-propoxy-2-oxazoline, 2-butoxy-2-oxazoline, 2-pentyloxy-2-oxazoline, 2-hexyloxy-2-oxazoline, 2-heptyloxy-2-oxazoline, 2-octyloxy-2-oxazoline, 2-nonyloxy-2-oxazoline, 2-decyloxy-2-oxazoline, 2-cyclopentyloxy-2- Oxazoline, 2-cyclohexyloxy-2-oxazoline, 2-allyloxy-2-oxazoline, 2-methallyloxy-2-oxazoline, 2-crotyloxy-2-oxazoline, 2-phenoxy-2-oxazoline, 2-cresyl-2 -Oxazoline, 2- -Ethylphenoxy-2-oxazoline, 2-o-propylphenoxy-2-oxazoline, 2-o-phenylphenoxy-2-oxazoline, 2-m-ethylphenoxy-2-oxazoline, 2-m-propylphenoxy-2- Oxazoline, 2-p-phenylphenoxy-2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-butyl-2-oxazoline, 2-pentyl-2 -Oxazoline, 2-hexyl-2-oxazoline, 2-heptyl-2-oxazoline, 2-octyl-2-oxazoline, 2-nonyl-2-oxazoline, 2-decyl-2-oxazoline, 2-cyclopentyl-2-oxazoline , 2-cyclohexyl-2-oxazoline, 2-allyl- -Oxazoline, 2-methallyl-2-oxazoline, 2-crotyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-o-ethylphenyl-2-oxazoline, 2-o-propylphenyl-2-oxazoline, 2 -O-phenylphenyl-2-oxazoline, 2-m-ethylphenyl-2-oxazoline, 2-m-propylphenyl-2-oxazoline, 2-p-phenylphenyl-2-oxazoline and the like, and 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4,4'-dimethyl-2-oxazoline), 2,2 '-Bis (4-ethyl-2-oxazoline), 2,2'-bis (4,4'-diethyl-2-oxazoline), 2,2'-bis (4-pro Pyr-2-oxazoline), 2,2'-bis (4-butyl-2-oxazoline), 2,2'-bis (4-hexyl-2-oxazoline), 2,2'-bis (4-phenyl- 2-oxazoline), 2,2'-bis (4-cyclohexyl-2-oxazoline), 2,2'-bis (4-benzyl-2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline) ), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-o-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline) 2,2'-p-phenylenebis (4,4'-dimethyl-2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylene Screw (4,4'-di Til-2-oxazoline), 2,2'-ethylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-hexamethylenebis (2-oxazoline), 2, 2'-octamethylenebis (2-oxazoline), 2,2'-decamethylenebis (2-oxazoline), 2,2'-ethylenebis (4-methyl-2-oxazoline), 2,2'-tetramethylene Bis (4,4′-dimethyl-2-oxazoline), 2,2′-9,9′-diphenoxyethane bis (2-oxazoline), 2,2′-cyclohexylene bis (2-oxazoline), 2, And 2'-diphenylenebis (2-oxazoline). Furthermore, a polyoxazoline compound containing the above-described compound as a monomer unit, such as a styrene-2-isopropenyl-2-oxazoline copolymer, can be mentioned. One or more compounds may be arbitrarily selected from these oxazoline compounds to block the carboxyl terminal of the polylactic acid unit.

  Examples of oxazine compounds include, for example, 2-methoxy-5,6-dihydro-4H-1,3-oxazine, 2-ethoxy-5,6-dihydro-4H-1,3-oxazine, 2-propoxy-5 , 6-dihydro-4H-1,3-oxazine, 2-butoxy-5,6-dihydro-4H-1,3-oxazine, 2-pentyloxy-5,6-dihydro-4H-1,3-oxazine, 2-hexyloxy-5,6-dihydro-4H-1,3-oxazine, 2-heptyloxy-5,6-dihydro-4H-1,3-oxazine, 2-octyloxy-5,6-dihydro-4H -1,3-oxazine, 2-nonyloxy-5,6-dihydro-4H-1,3-oxazine, 2-decyloxy-5,6-dihydro-4H-1,3-oxazine, 2-cyclopent Ruoxy-5,6-dihydro-4H-1,3-oxazine, 2-cyclohexyloxy-5,6-dihydro-4H-1,3-oxazine, 2-allyloxy-5,6-dihydro-4H-1,3 -Oxazine, 2-methallyloxy-5,6-dihydro-4H-1,3-oxazine, 2-crotyloxy-5,6-dihydro-4H-1,3-oxazine, and the like. 2'-bis (5,6-dihydro-4H-1,3-oxazine), 2,2'-methylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-ethylenebis ( 5,6-dihydro-4H-1,3-oxazine), 2,2′-propylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2′-butylenebis (5,6-dihydro) -4H-1 3-oxazine), 2,2'-hexamethylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-p-phenylenebis (5,6-dihydro-4H-1,3 -Oxazine), 2,2'-m-phenylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-naphthylenebis (5,6-dihydro-4H-1,3-oxazine) 2,2′-P, P′-diphenylenebis (5,6-dihydro-4H-1,3-oxazine) and the like. Furthermore, the polyoxazine compound etc. which contain an above-described compound as a monomer unit are mentioned. One or two or more compounds may be arbitrarily selected from these oxazine compounds to block the carboxyl terminal of the polylactic acid unit.

  Further, one or more compounds selected from the oxazoline compounds exemplified above and the above-mentioned oxazine compounds may be arbitrarily selected and used together to block the carboxyl end of polylactic acid. 2,2′-m-phenylenebis (2-oxazoline) and 2,2′-p-phenylenebis (2-oxazoline) are preferable from the viewpoints of affinity and affinity with aliphatic polyester.

  Examples of the aziridine compound among the end-capping agents that can be used in the present invention include, for example, an addition reaction product of a mono-, bis- or polyisocyanate compound and ethyleneimine.

  Moreover, 2 or more types of compounds can also be used together as a terminal blocker among compounds, such as the carbodiimide compound mentioned above as an end blocker which can be used for this invention, an epoxy compound, an oxazoline compound, an oxazine compound, and an aziridine compound.

  As a method for blocking the carboxyl group terminal of the polylactic acid resin (component A) in the resin composition constituting the thermoformed product of the present invention, a terminal blocking agent such as a condensation reaction type or an addition reaction type may be reacted. As a method of blocking the carboxyl group terminal by a condensation reaction, an appropriate amount of a condensation reaction type terminal blocking agent such as an aliphatic alcohol or an amide compound is added to the polymerization system during polymer polymerization, and a dehydration condensation reaction is performed by reducing the pressure. Although the carboxyl group terminal can be blocked, it is preferable to add a condensation reaction type terminal blocking agent at the end of the polymerization reaction from the viewpoint of increasing the degree of polymerization of the polymer.

  As a method for blocking the carboxyl group terminal by addition reaction, it can be obtained by reacting an appropriate amount of a terminal blocking agent such as a carbodiimide compound, an epoxy compound, an oxazoline compound, an oxazine compound, or an aziridine compound in the molten state of polylactic acid. It is possible to add and react the end-capping agent after the polymerization reaction.

  The content of the terminal blocking agent (component B) is 0.01 to 5 parts by weight, preferably 0.05 to 4 parts by weight, more preferably 0.1 per 100 parts by weight of the polylactic acid resin (component A). ~ 3 parts by weight.

<About other ingredients>
(I) Crystal nucleating agent A crystal nucleating agent can be added to the polylactic acid (component A) constituting the thermoformed product of the present invention. As the crystal nucleating agent, polylactic acid and known compounds that are generally used as crystal nucleating agents for crystalline resins such as aromatic polyesters are mainly targeted.
For example, inorganic fine particles such as talc, silica, graphite, carbon powder, pyroferrite, gypsum, neutral clay, metal oxides such as magnesium oxide, aluminum oxide, titanium dioxide, sulfate, phosphate, phosphonate, Examples thereof include oxalate, oxalate, stearate, benzoate, salicylate, tartrate, sulfonate, montan wax salt, montan wax ester salt, terephthalate, benzoate, carboxylate and the like.

  Among these compounds used as the crystal nucleating agent, talc is particularly effective, and those having an average particle size of 20 μm or less are preferably used, but those having an average particle size of 5 μm or less are more preferable. .

  The blending amount of these crystal nucleating agents cannot be uniformly defined because the amount of the effect varies depending on the type and shape of the crystal nucleating agent, but is 0.01% per 100 parts by weight of the polylactic acid resin (component A). -5 parts by weight, preferably 0.05-3 parts by weight, more preferably 0.1-2 parts by weight. If the amount of the crystal nucleating agent is too small, the effect as a crystal nucleating agent will not be exhibited, and conversely, if it is too much, the effect as a crystal nucleating agent will not be increased. May give bad results.

  Although there is no restriction | limiting in particular in the compounding method of the crystal nucleating agent used in this invention, The polylactic acid unit (a-1 to a-2 component) which mainly consists of L-lactic acid units, and the polylactic acid unit which mainly consists of D-lactic acid units After mixing (b-1 to b-2 components), if there are other components to be blended if necessary, the method of adding when mixing with them is preferable because the adverse effect on stereo complex formation is small .

(Ii) Inorganic filler When an inorganic filler is further added to the polylactic acid constituting the thermoformed product of the present invention, a thermoformed product having excellent mechanical properties, dimensional properties, and the like can be obtained.
As inorganic fillers, various inorganic fillers generally known such as glass fiber, carbon fiber, glass flake, wollastonite, kaolin clay, mica, talc and various whiskers (potassium titanate whisker, aluminum borate whisker, etc.) Materials can be mentioned. The shape of the inorganic filler can be freely selected from fibrous, flaky, spherical and hollow shapes, and fibrous and flaky materials are suitable for improving the strength and impact resistance of the resin composition.

  Among them, the inorganic filler is preferably an inorganic filler made of a pulverized product of natural mineral, more preferably an inorganic filler made of a pulverized product of a natural mineral of silicate, and from the point of its shape. Are preferably mica, talc, and wollastonite.

  On the other hand, since these inorganic fillers are non-petroleum resource materials compared to petroleum resource materials such as carbon fibers, raw materials with a lower environmental load are used. There exists an effect that the significance which uses C component is raised more. Furthermore, the above-mentioned more preferable inorganic filler has an advantageous effect that good flame retardancy is exhibited as compared with carbon fiber and the like.

  The average particle diameter of mica that can be used in the present invention is a number average particle diameter calculated by a number average of a total of 1,000 particles observed with a scanning electron microscope and extracted those having a size of 1 μm or more. The number average particle diameter is preferably 10 to 500 μm, more preferably 30 to 400 μm, still more preferably 30 to 200 μm, and most preferably 35 to 80 μm. When the number average particle diameter is less than 10 μm, the impact strength may be lowered. On the other hand, if it exceeds 500 μm, the impact strength is improved, but the appearance tends to deteriorate.

  As the thickness of mica, one having a thickness measured by electron microscope observation of 0.01 to 10 μm can be used. Preferably 0.1-5 micrometers thing can be used. An aspect ratio of 5 to 200, preferably 10 to 100 can be used. The mica used is preferably mascobite mica, and its Mohs hardness is about 3. Muscovite mica can achieve higher rigidity and strength than other mica such as phlogopite, and more suitable electronic equipment exterior parts are provided.

  In addition, as a method for pulverizing mica, a dry pulverization method of pulverizing raw mica ore with a dry pulverizer, and coarsely pulverizing mica rough ore with a dry pulverizer, followed by adding a grinding aid such as water in a slurry state There is a wet pulverization method in which main pulverization is performed by a wet pulverizer, followed by dehydration and drying. The mica of the present invention can be produced by any pulverization method, but the dry pulverization method is generally lower in cost. On the other hand, the wet pulverization method is effective for pulverizing mica more thinly and finely, but is expensive. Mica may be surface-treated with various surface treatment agents such as silane coupling agents, higher fatty acid esters, and waxes, and further granulated with sizing agents such as various resins, higher fatty acid esters, and waxes to form granules. May be.

Talc that can be used in the present invention is a scaly particle having a layered structure, which is a hydrous magnesium silicate in terms of chemical composition, and is generally represented by the chemical formula 4SiO ₂ .3MgO.2H ₂ O. the SiO ₂ 56-65 wt%, the MgO 28 to 35 wt%, and a H ₂ O about 5 wt%. As other minor components, Fe ₂ O ₃ is 0.03 to 1.2% by weight, Al ₂ O ₃ is 0.05 to 1.5% by weight, CaO is 0.05 to 1.2% by weight, K ₂ O. Is 0.2 wt% or less, Na ₂ O is 0.2 wt% or less, the specific gravity is about 2.7, and the Mohs hardness is 1.

  The average particle diameter of the talc of the present invention is preferably 0.5 to 30 μm. The average particle size is a particle size at a 50% stacking rate obtained from the particle size distribution measured by the Andreazen pipette method measured according to JIS M8016. The particle diameter of talc is more preferably 2 to 30 μm, further preferably 5 to 20 μm, and most preferably 10 to 20 μm. Talc in the range of 0.5 to 30 μm imparts good surface appearance and flame retardancy to the molded product in addition to rigidity and low anisotropy.

  In addition, there is no particular restriction on the manufacturing method when talc is crushed from raw stone, and the axial flow mill method, the annular mill method, the roll mill method, the ball mill method, the jet mill method, the container rotary compression shearing mill method, etc. are used. can do. Further, the talc after pulverization is preferably classified by various classifiers and having a uniform particle size distribution. There are no particular restrictions on the classifier, impactor type inertial force classifier (variable impactor, etc.), Coanda effect type inertial force classifier (elbow jet, etc.), centrifugal field classifier (multistage cyclone, microplex, dispersion separator) , Accucut, Turbo Classifier, Turboplex, Micron Separator, and Super Separator).

  Further, talc is preferably in an agglomerated state in view of its handleability and the like, and as such a production method, there are a method by deaeration compression, a method of compression using a sizing agent, and the like. In particular, the degassing compression method is preferred because it is simple and does not include unnecessary sizing agent resin components in the electronic device exterior component of the present invention.

The wollastonite that can be used in the present invention is substantially represented by the chemical formula CaSiO ₃ , usually SiO ₂ is about 50 wt% or more, CaO is about 47 wt% or more, and other Fe ₂ O ₃ , Al ₂ O _3. Etc. Wollastonite is a white acicular powder obtained by crushing and classifying raw wollastonite, and has a Mohs hardness of about 4.5. The average fiber diameter of wollastonite used is preferably 0.5 to 20 μm, more preferably 0.5 to 10 μm, and most preferably 1 to 5 μm. The average fiber diameter is observed by a scanning electron microscope, and is calculated by a number average of a total of 1000 samples having a diameter of 0.1 μm or more extracted.

  Some of these inorganic fillers also function as crystal nucleating agents, but when used as inorganic fillers for the purpose of improving mechanical properties and the like, the blending amount is 100 parts by weight of polylactic acid resin (component A), 0.3 to 200 parts by weight is preferable, 1.0 to 100 parts by weight is more preferable, and 3 to 50 parts by weight is most preferable. When the blending amount is less than 0.3 parts by weight, the reinforcing effect on the mechanical properties of the molded product of the present invention is not sufficient, and when it exceeds 200 parts by weight, molding processability and hue may be deteriorated. .

  In addition, in the resin composition which comprises a thermoformed product, when using a fibrous inorganic filler and a flaky inorganic filler, the folding inhibitor for suppressing those folding can be included. The folding inhibitor inhibits adhesion between the matrix resin and the inorganic filler, reduces stress acting on the inorganic filler during melt kneading, and suppresses the folding of the inorganic filler. Examples of the effect of the folding inhibitor include (1) improvement of rigidity (increase in aspect ratio of inorganic filler), (2) improvement of toughness, and (3) improvement of conductivity (in the case of conductive inorganic filler). Can do. Specifically, the folding inhibitor includes (i) a compound obtained by directly coating a surface of an inorganic filler with a compound having a low affinity with a resin, and (ii) an inorganic filler having a structure with a low affinity with a resin. A compound having a functional group capable of reacting with the surface.

  Representative examples of the compound having a low affinity for the resin include various lubricants. Examples of the lubricant include mineral oil, synthetic oil, higher fatty acid ester, higher fatty acid amide, polyorganosiloxane (silicone oil, silicone rubber, etc.), olefinic wax (paraffin wax, polyolefin wax, etc.), polyalkylene glycol, fluorinated fatty acid. Fluorine oils such as esters, trifluorochloroethylene, and polyhexafluoropropylene glycol are listed.

  As a method of directly coating the surface of the inorganic filler with a compound having a low affinity for the resin, (1) a method of directly immersing the compound or a solution or emulsion of the compound in the inorganic filler; A method of passing an inorganic filler in the vapor or powder of a compound, (3) a method of irradiating the inorganic filler with the powder of the compound at high speed, and (4) a mechanochemical that rubs the inorganic filler and the compound. And the like.

  Examples of the compound having a structure having a low affinity with the resin and having a functional group capable of reacting with the surface of the inorganic filler include the above-described lubricants modified with various functional groups. Examples of such functional groups include a carboxyl group, a carboxylic acid anhydride group, an epoxy group, an oxazoline group, an isocyanate group, an ester group, an amino group, and an alkoxysilyl group.

  One suitable folding inhibitor is an alkoxysilane compound in which an alkyl group having 5 or more carbon atoms is bonded to a silicon atom. The number of carbon atoms of the alkyl group bonded to the silicon atom is preferably 5 to 60, more preferably 5 to 20, still more preferably 6 to 18, and particularly preferably 8 to 16. The alkyl group bonded to the silicon atom is preferably 1 or 2, and more preferably 1. Further, preferred examples of the alkoxy group include a methoxy group and an ethoxy group. Such alkoxysilane compounds are preferred in that they have high reactivity with the inorganic filler surface and excellent coating efficiency. Therefore, it is suitable for a finer inorganic filler.

  One suitable folding inhibitor is a polyolefin wax having at least one functional group selected from a carboxyl group and a carboxylic anhydride group. The molecular weight is preferably 500 to 20,000, more preferably 1,000 to 15,000 in terms of weight average molecular weight. In such a polyolefin wax, the amount of carboxyl group and carboxylic anhydride group is in the range of 0.05 to 10 meq / g per gram of lubricant having at least one functional group selected from carboxyl group and carboxylic anhydride group. Is preferable, more preferably 0.1 to 6 meq / g, and still more preferably 0.5 to 4 meq / g. It is preferable that the ratio of the functional group in the folding inhibitor is the same as the ratio of the carboxyl group and the carboxylic anhydride group in the functional group other than the carboxyl group.

More preferable examples of the folding inhibitor include a copolymer of an α-olefin and maleic anhydride. Such a copolymer can be produced by melt polymerization or bulk polymerization in the presence of a radical catalyst according to a conventional method. Here, as the α-olefin, those having 10 to 60 carbon atoms as an average value can be preferably exemplified. More preferable examples of the α-olefin include those having an average carbon number of 16 to 60, and more preferably 25 to 55.
The folding inhibitor is preferably 0.01 to 2 parts by weight, more preferably 0.05 to 1.5 parts by weight, and more preferably 0.1 to 0.8 parts by weight per 100 parts by weight of the polylactic acid resin (component A) of the present invention. Part is more preferable.

(Iii) Flame retardant A flame retardant can also be mix | blended with the resin composition which comprises the thermoforming goods of this invention. Flame retardants include brominated epoxy resins, brominated polystyrenes, brominated polycarbonates, brominated polyacrylates, halogenated flame retardants such as chlorinated polyethylene, phosphate ester flame retardants such as monophosphate compounds and phosphate oligomer compounds, Organophosphorous flame retardants other than phosphate ester flame retardants such as phosphonate oligomer compounds, phosphonitrile oligomer compounds, phosphonic acid amide compounds, organic sulfonate alkali (earth) metal salts, borate metal salt flame retardants, and tin Examples include organic metal salt flame retardants such as acid metal salt flame retardants, and silicone flame retardants. Separately, a flame retardant aid (for example, sodium antimonate, antimony trioxide, etc.), an anti-drip agent (polytetrafluoroethylene having fibril-forming ability, etc.), etc. may be blended and used together with the flame retardant.

  Among the above-mentioned flame retardants, compounds that do not contain chlorine and bromine atoms have reduced features that are undesirable when performing incineration and thermal recycling. It is more suitable as a flame retardant in the molded product of the present invention.

  Furthermore, the phosphate ester flame retardant is particularly preferable because a good hue can be obtained and an effect of improving molding processability can be exhibited. Specific examples of the phosphate ester flame retardant include one or more phosphate ester compounds represented by the following general formula (ii).

(However, X in the above formula is hydroquinone, resorcinol, bis (4-hydroxydiphenyl) methane, bisphenol A, dihydroxydiphenyl, dihydroxynaphthalene, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis A group derived from (4-hydroxyphenyl) sulfide, and n is an integer of 0 to 5, or an average value of 0 to 5 in the case of a mixture of phosphate esters having different numbers of n, R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ are each independently a group derived from phenol, cresol, xylenol, isopropylphenol, butylphenol, or p-cumylphenol substituted or unsubstituted with one or more halogen atoms. .)

More preferable examples include groups in which X in the above formula is derived from hydroquinone, resorcinol, bisphenol A, and dihydroxydiphenyl, and n is an integer of 1 to 3, or a different number of phosphate esters. In the case of blends of R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each independently of one or more halogen atoms substituted or more preferably substituted phenol, cresol, A group derived from xylenol.

  Among such organophosphate flame retardants, triphenyl phosphate is preferable as a phosphate compound, and resorcinol bis (dixylyl phosphate) and bisphenol A bis (diphenyl phosphate) are preferable as phosphate oligomers because of their excellent hydrolysis resistance. it can. More preferable are resorcinol bis (dixylyl phosphate) and bisphenol A bis (diphenyl phosphate) from the viewpoint of heat resistance. This is because they have good heat resistance and are free from adverse effects such as thermal deterioration and volatilization.

  In the resin composition constituting the thermoformed article of the present invention, when these flame retardants are blended, the range of 0.05 to 50 parts by weight per 100 parts by weight of the polylactic acid resin (component A) is preferable. If it is less than 0.05 part by weight, sufficient flame retardancy will not be exhibited, and if it exceeds 50 parts by weight, the strength and heat resistance of the molded product will be impaired.

(Iv) Stabilizer The resin composition constituting the thermoformed article of the present invention preferably contains a stabilizer in order to obtain a better hue and stable fluidity. Examples of the stabilizer include hindered phenol compounds, thioether compounds, vitamin compounds, triazole compounds, polyvalent amine compounds, hydrazine derivative compounds, phosphorus compounds, and the like. Good. Among them, it is preferable to include at least one phosphorus compound, and it is more preferable to use a phosphate compound or a phosphite compound. As further preferred examples of specific examples, “ADEKA STAB” AX-71 (dioftademil phosphate) manufactured by ADEKA, PEP-8 (distearyl pentaerythritol diphosphite), PEP-36 (cyclic neopentatetrayl bis (2, 6-t-butyl-4-methylphenyl) phosphite). The phosphorus stabilizer is a deactivator of the amidation catalyst and / or each polylactic acid unit (a-1 to a-2 component and b-1 to b-2) constituting the polylactic acid resin (component A). It is considered to act as a deactivator for the catalyst used in the preparation of the component) and is effective as a catalyst removal method in the production of the polylactic acid resin in the present invention.

  Specific examples of hindered phenol compounds include n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, n-octadecyl-3- (3-methyl-5-t -Butyl-4-hydroxyphenyl) -propionate, n-tetradecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, 1,6-hexanediol-bis- [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) -propionate], 1,4-butanediol-bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate], 2,2'-methylenebis- (4-methyl-t-butylphenol), triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4- Droxyphenyl) -propionate], tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 3,9-bis [2- {3- (3-t- Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, N, N′-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl hexamethylenediamine, N, N′-tetramethylene-bis-3- (3-methyl-5-tert-butyl-4-hydroxyphenol) propionyl Diamine, N, N′-bis- [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionyl] hydrazine, N-salicyloyl-N′-salicyle Nhydrazine, 3- (N-salicyloyl) amino-1,2,4-triazole, N, N′-bis [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy } Ethyl] oxyamide, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis- (3,5-di-t- Butyl-4-hydroxy-hydrocinnamide, etc. Preferably, triethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate], tetrakis [ Methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,6-hexanediol-bis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate], pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N '-Hexamethylenebis- (3,5-di-t-butyl-4-hydroxy-hydrocinnamide. Specific product names of hindered phenol compounds include “ADEKA STAB” AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80, and AO-330 manufactured by ADEKA. "Irganox" 245, 259, 565, 1010, 1035, 1035, 1076, 1098, 1222, 1330, 1425, 1520, 3114, 5057 manufactured by Ciba Specialty Chemicals Co., Ltd. "Sumilyzer" BHT-R manufactured by Sumitomo Chemical Co., Ltd. , MDP-S, BBM-S, WX-R, NW, BP-76, BP-101, GA-80, GM, GS, "Sianox" CY-1790 manufactured by Cyanamid Co., Ltd., and the like.

  Specific examples of the thioether compound include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate) Pentaerythritol-tetrakis (3-dodecylthiopropionate), pentaerythritol-tetrakis (3-octadecylthiopropionate), pentaerythritol-tetrakis (3-myristylthiopropionate), pentaerythritol-tetrakis (3- Stearylthiopropionate). Specific product names of the thioether compounds include “ADEKA STAB” A0-23, AO-412S, AO-503A manufactured by ADEKA Corporation, “Irganox” PS802 manufactured by Ciba Specialty Chemicals Co., Ltd., Sumitomo Chemical Co., Ltd. "Smilizer" TPL-R, TPM, TPS, TP-D, DSTP, DLTP, DLTOIB, DMTP manufactured by API Corporation, "Sinox" 412S manufactured by Cypro Kasei Co., Ltd. Knox "1212 etc. are mentioned.

Specific examples of the vitamin compound include d-α-tocopherol acetate, d-α-tocopherol succinate, d-α-tocopherol, d-β-tocopherol, d-γ-tocopherol, d-δ-tocopherol, d- Natural products such as α-tocotrienol, d-β-tocofetrienol, d-γ-tocofetrienol, d-δ-tocofetrienol, dl-α-tocopherol, dl-α-tocopherol acetate, succinic acid Synthetic products such as dl-α-tocopherol calcium and dl-α-tocopherol nicotinate can be mentioned. Specific product names of vitamin compounds include “Tocopherol” manufactured by Eisai Co., Ltd., “Irganox” E201 manufactured by Ciba Specialty Chemicals Co., Ltd. and the like.
Specific examples of the triazole compound include benzotriazole, 3- (N-salicyloyl) amino-1,2,4-triazole, and the like.

  Specific examples of the polyvalent amine compound include 3,9-bis [2- (3,5-diamino-2,4,6-triazaphenyl) ethyl] -2,4,8,10-tetraoxaspiro. [5.5] Undecane, ethylenediamine-tetraacetic acid, alkali metal salt (Li, Na, K) of ethylenediamine-tetraacetic acid, N, N′-disalicylidene-ethylenediamine, N, N′-disalicylidene-1 , 2-propylenediamine, N, N ″ -disalicylidene-N′-methyl-dipropylenetriamine, 3-salicyloylamino-1,2,4-triazole and the like.

  Specific examples of the hydrazine derivative-based compound include decamethylene dicarboxyl acid-bis (N′-salicyloyl hydrazide), bis (2-phenoxypropionyl hydrazide) isophthalate, N-formyl-N′-salicyloyl hydrazine. 2,2-oxamide bis- [ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], oxalyl-bis-benzylidene-hydrazide, nickel-bis (1-phenyl-3- Methyl-4-decanoyl-5-pyrazolate), 2-ethoxy-2′-ethyloxanilide, 5-t-butyl-2-ethoxy-2′-ethyloxanilide, N, N-diethyl-N ′, N′-diphenyl oxamide, N, N′-diethyl-N, N′-diphenyl oxamide, oxalic acid (Benzylidene hydrazide), thiodipropionic acid-bis (benzylidene hydrazide), bis (salicyloyl hydrazine), N-salicylidene-N′-salicyloyl hydrazone, N, N′-bis [3- (3 5-Di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, N, N′-bis [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] Oxamide etc. are mentioned.

  Examples of phosphorus compounds include phosphite compounds and phosphate compounds. Specific examples of such phosphite compounds include tetrakis [2-t-butyl-4-thio (2-methyl-4-hydroxy-5-t-butylphenyl) -5-methylphenyl] -1,6-hexa. Methylene-bis (N-hydroxyethyl-N-methylsemicarbazide) -diphosphite, tetrakis [2-tert-butyl-4-thio (2-methyl-4-hydroxy-5-tert-butylphenyl) -5-methylphenyl] -1,10-Decamethylene-di-carboxylic acid-di-hydroxyethylcarbonylhydrazide-diphosphite, tetrakis [2-tert-butyl-4-thio (2-methyl-4-hydroxy-5-tert-butylphenyl)- 5-methylphenyl] -1,10-decamethylene-di-carboxylic acid-di-salicyloyl Razide-diphosphite, tetrakis [2-t-butyl-4-thio (2-methyl-4-hydroxy-5-t-butylphenyl) -5-methylphenyl] -di (hydroxyethylcarbonyl) hydrazide-diphosphite, tetrakis [ 2-t-butyl-4-thio (2-methyl-4-hydroxy-5-t-butylphenyl) -5-methylphenyl] -N, N′-bis (hydroxyethyl) oxamide-diphosphite and the like. More preferably, at least one P—O bond is bonded to an aromatic group. Specific examples include tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di -T-butylphenyl) 4,4'-biphenylene phosphonite, bis (2,4-di-t-butylphenyl) pentaerythritol -Di-phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) Octyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-ditridecyl phosphite— 5-t-butyl-phenyl) butane, tris (mixed-mono and di-nonylphenyl) phosphite, tris (nonylphenyl) phosphite, 4,4′-isopropylidenebis (phenyl-dialkyl phosphite) and the like Tris (2,4-di-t-butylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylpheny ) Octyl phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene Phosphonite can be preferably used. Specific product names of phosphite compounds include “ADEKA STAB” C, PEP-4C, PEP-8, PEP-11C, PEP-24G, PEP-36, HP-10, 2112 and 260 manufactured by ADEKA Corporation. 522A, 329A, 1178, 1500, C, 135A, 3010, TPP, "Irgaphos" 168, manufactured by Ciba Specialty Chemicals, "Sumilyzer" P-16, manufactured by Sumitomo Chemical Co., Ltd., "sand stubs, manufactured by Clariant Co., Ltd. “PEPQ, manufactured by GE“ Weston ”618, 619G, 624, and the like.

  Specific examples of the phosphate compound include monostearyl acid phosphate, distearyl acid phosphate, methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, octyl acid phosphate, isodecyl acid phosphate, etc., among them monostearyl acid phosphate Distearyl acid phosphate is preferred. Specific product names of phosphate compounds include “Irganox” MD1024 manufactured by Ciba Specialty Chemicals, Inc. “Inhibitor” OABH manufactured by Eastman Kodak Co., Ltd., “Adeka Stub” CDA-1, manufactured by ADEKA Corporation, CDA-6, AX-71, etc. can be mentioned.

  Said stabilizer can be used individually or in combination of 2 or more types. The stabilizer is preferably added in an amount of 0.001 to 5 parts by weight, more preferably 0.01 to 3 parts by weight, and still more preferably 0.01 to 1 part by weight per 100 parts by weight of the polylactic acid resin (component A).

(V) Elastic polymer In the resin composition constituting the thermoformed article of the present invention, an elastic polymer can be used as an impact modifier. As an example of the elastic polymer, the glass transition temperature is 10 ° C. or less. Graft copolymer obtained by copolymerizing one or more monomers selected from aromatic vinyl, vinyl cyanide, acrylic acid ester, methacrylic acid ester, and vinyl compounds copolymerizable with these rubber components Coalescence can be mentioned. A more preferable elastic polymer is a core-shell type graft copolymer in which one or more shells of the above-mentioned monomer are graft-copolymerized on the core of the rubber component.

  Moreover, the rubber component and the block copolymer of the said monomer are also mentioned. Specific examples of such block copolymers include thermoplastic elastomers such as styrene / ethylenepropylene / styrene elastomers (hydrogenated styrene / isoprene / styrene elastomers) and hydrogenated styrene / butadiene / styrene elastomers. Furthermore, various elastic polymers known as other thermoplastic elastomers such as polyurethane elastomers, polyester elastomers, polyether amide elastomers and the like can also be used.

  A core-shell type graft copolymer is more suitable as an impact modifier. In the core-shell type graft copolymer, the core particle size is preferably 0.05 to 0.8 μm, more preferably 0.1 to 0.6 μm, and more preferably 0.1 to 0.5 μm in weight average particle size. Is more preferable. If it is in the range of 0.05 to 0.8 μm, better impact resistance is achieved. The elastic polymer preferably contains 40% or more of a rubber component, and more preferably contains 60% or more.

  Rubber components include butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, acrylic-silicone composite rubber, isobutylene-silicone composite rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, nitrile rubber, ethylene- Acrylic rubber, silicone rubber, epichlorohydrin rubber, fluororubber, and those in which hydrogen is added to these unsaturated bonds may include halogen atoms because of concerns about the generation of harmful substances during combustion. No rubber component is preferable in terms of environmental load.

  The glass transition temperature of the rubber component is preferably −10 ° C. or lower, more preferably −30 ° C. or lower. As the rubber component, butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, and acrylic-silicone composite rubber are particularly preferable. The composite rubber is a rubber obtained by copolymerizing two kinds of rubber components or a rubber polymerized so as to have an IPN structure entangled with each other so as not to be separated.

  Examples of the aromatic vinyl in the vinyl compound copolymerized with the rubber component include styrene, α-methylstyrene, p-methylstyrene, alkoxystyrene, halogenated styrene and the like, and styrene is particularly preferable. Examples of the acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, octyl acrylate, and the like. Examples of the methacrylate ester include methyl methacrylate, ethyl methacrylate, butyl methacrylate. , Cyclohexyl methacrylate, octyl methacrylate and the like, and methyl methacrylate is particularly preferable. Among these, it is particularly preferable to contain a methacrylic ester such as methyl methacrylate as an essential component. More specifically, the methacrylic acid ester is contained in 100% by weight of the graft component (in the case of the core-shell type polymer in 100% by weight of the shell), preferably 10% by weight or more, more preferably 15% by weight or more. The

  The elastic polymer containing a rubber component having a glass transition temperature of 10 ° C. or less may be produced by any polymerization method including bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. It can be a single-stage graft or a multi-stage graft. Moreover, the mixture with the copolymer of only the graft component byproduced in the case of manufacture may be sufficient. Furthermore, examples of the polymerization method include a general emulsion polymerization method, a soap-free polymerization method using an initiator such as potassium persulfate, a seed polymerization method, and a two-stage swelling polymerization method. In the suspension polymerization method, the aqueous phase and the monomer phase are individually maintained, both are accurately supplied to the continuous disperser, and the particle diameter is controlled by the rotation speed of the disperser, and the continuous production is performed. In the method, a method may be used in which the monomer phase is supplied by passing it through a fine orifice having a diameter of several to several tens of μm or a porous filter in an aqueous liquid having dispersibility to control the particle size. In the case of a core-shell type graft polymer, the reaction may be one stage or multistage for both the core and the shell.

  Such elastic polymers are commercially available and can be easily obtained. For example, as rubber components mainly composed of butadiene rubber, acrylic rubber or butadiene-acrylic composite rubber, Kane Ace B series (for example, B-56 etc.) of Kanegafuchi Chemical Industry Co., Ltd. and Metabrene of Mitsubishi Rayon Co., Ltd. C series (for example, C-223A), W series (for example, W-450A), paraloid EXL series (for example, EXL-2602) by Kureha Chemical Industry, HIA series (for example, HIA-15), BTA series (E.g., BTA-III), KCA series, Rohm and Haas Paraloid EXL series, KM series (e.g., KM-336P, KM-357P, etc.) and UCL modifier resin series (UMG) of Ube Saikon Co., Ltd.・ ABS's MG AXS Resin Series) and the like, and those mainly composed of acrylic-silicone composite rubber as the rubber component are those commercially available from Mitsubishi Rayon Co., Ltd. under the trade name Methbrene S-2001 or SRK-200. It is done.

  The composition ratio of the impact modifier is preferably 0.2 to 50 parts by weight per 100 parts by weight of the polylactic acid resin (component A), preferably 1 to 30 parts by weight, and more preferably 1.5 to 20 parts by weight. Such a composition range can give good impact resistance to the composition while suppressing a decrease in rigidity.

(Vi) Other additives In the resin composition constituting the thermoformed article of the present invention, other thermoplastic resins (for example, polycarbonate resin, polyalkylene terephthalate resin, polyarylate) are included within the range where the effects of the present invention are exhibited. Resin, liquid crystalline polyester resin, polyamide resin, polyimide resin, polyetherimide resin, polyurethane resin, silicone resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyolefin resin such as polyethylene and polypropylene, polystyrene resin, acrylonitrile / styrene copolymer Polymer (AS resin), Acrylonitrile / butadiene / styrene copolymer (ABS resin), Polystyrene resin, High impact polystyrene resin, Syndiotactic polystyrene resin, Polymethacrylate Resins, phenoxy or epoxy resins, etc.), UV absorbers (benzotriazole compounds, triazine compounds, benzophenone compounds, etc.), light stabilizers (HALS, etc.), mold release agents (saturated fatty acid esters, unsaturated fatty acid esters, polyolefins) Wax, fluorine compounds, paraffin wax, beeswax, etc.), flow modifiers (polycaprolactone, etc.), colorants (carbon black, titanium dioxide, various organic dyes, metallic pigments, etc.), light diffusing agents (acrylic crosslinked particles, Silicone cross-linked particles, etc.), fluorescent brighteners, phosphorescent pigments, fluorescent dyes, antistatic agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents (fine titanium oxide, fine zinc oxide, etc.), infrared absorbers, and photochromic You may mix | blend an agent ultraviolet absorber. These various additives can be used in known blending amounts when blended with a thermoplastic resin such as polylactic acid.

<About the compound manufacturing method>
In order to manufacture the compound which comprises the thermoformed product of this invention, arbitrary methods are employ | adopted. For example, each component and optionally other components can be premixed and then melt-kneaded and pelletized. Examples of the premixing means include a Nauter mixer, a V-type blender, a Henschel mixer, a mechanochemical apparatus, and an extrusion mixer. In the preliminary mixing, granulation can be performed by an extrusion granulator or a briquetting machine depending on the case. After the preliminary mixing, the mixture is melt-kneaded by a melt-kneader represented by a vent type twin-screw extruder and pelletized by a device such as a pelletizer. Other examples of the melt kneader include a Banbury mixer, a kneading roll, and a constant-temperature stirring vessel, but a vent type twin screw extruder is preferable. In addition, each component and optionally other components can be independently supplied to a melt-kneader represented by a twin-screw extruder without being premixed.

<Manufacture of thermoformed products>
The thermoformed product in the present invention is manufactured using a sheet-like molded product.
A sheet-like molded product can be prepared by generally known equipment and methods. That is, when there is polylactic acid or a compounding agent in the extruder, it is supplied together with all or a part of the components, extruded through a slit-shaped die, cooled and solidified on a casting drum, and formed into a sheet. Obtained by. Examples of a method for supplying the polylactic acid of the present invention to an extruder include: 1. A method for preparing a sheet by mixing each component and then preparing a sheet by melt-kneading and extruding with an extruder to prepare pellets, and then supplying the pellets to an extruder equipped with a slit die. 2. A method of once preparing pellets having different compositions, mixing a predetermined amount of the pellets, and supplying the pellets to a sheet forming extruder to obtain a “sheet”; Any method can be used such as a method of directly charging one or more of each component into an extruder for producing a sheet. In addition to this, one of the materials or components used for forming a sheet is also a sheet, a thermoformed product, and / or a pulverized die-cut scrap generated when thermoformed. It can also be used as It is preferable to mix a part of the components as a fine powder with other components and add them in order to uniformly mix these components. In addition, it is preferable to dry before supplying a pellet and a component to an extruder.

Further, when casting, a sheet having excellent flatness can be obtained by applying static electricity to the sheet and bringing it into close contact with the cooling drum.
By thermoforming the sheet of the present invention obtained as described above, various shapes can be formed and can be used for various applications.
The sheet obtained as described above is preheated by an infrared heater, a hot plate heater, hot air or the like and then subjected to thermoforming.

  As a thermoforming method, a female mold, a female mold and a male mold, or a plug is used, and for example, vacuum molding, pressure molding, or vacuum / pressure molding is employed. During molding, the female type, male type and plug can be heated.

  In the present invention, all or a part of the processed product or thermoformed product of the sheet may be bonded to each other or other materials to further increase the degree of processing, and various functional materials may be applied and used. Sometimes.

  In the thermoformed product of the present invention, the ratio of the melting peak at 195 ° C. or higher is preferably 70% or higher in the melting peak derived from polylactic acid in the temperature rising process of differential scanning calorimeter (DSC) measurement, preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. The larger the ratio of the melting peak at 195 ° C. or higher, the higher the hydrolysis resistance of the thermoformed product.

  The melting point is preferably in the range of 195 to 250 ° C, more preferably in the range of 200 to 220 ° C. The melting enthalpy is preferably 10 J / g or more, more preferably 20 J / g or more, and still more preferably 30 J / g or more.

  Specifically, in the melting peak derived from polylactic acid in the temperature rising process of differential scanning calorimetry (DSC) measurement, the ratio of the melting peak at 195 ° C. or higher is 70% or higher, and the melting point is in the range of 195 to 250 ° C. The melting enthalpy is preferably 10 J / g or more.

  The thermoformed product of the present invention is useful for packaging because it is excellent in heat resistance and hydrolysis resistance. For example, packaging of miscellaneous goods, toys, clothing, food, etc., optical products, OA products, electrical products, Used for packaging tools, machines, other industrial products, or parts thereof. However, the product of the present invention is used not only for packaging, but also as a component part of an electric device, an electronic device, an OA device, an electric machine, and other various devices and a component material of the component. Moreover, it can use as a base material of various tapes, or a base material of a product.

  Furthermore, the thermoformed product of the present invention can be provided with other functions by surface modification. Surface modification here means a new layer on the surface of resin molded products such as vapor deposition (physical vapor deposition, chemical vapor deposition, etc.), plating (electroplating, electroless plating, hot dipping, etc.), painting, coating, printing, etc. The method used for extrusion molded articles, such as a normal sheet | seat and a film, is applicable.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to these.
Polylactic acid units were produced by the method shown in the production examples below. Moreover, each value in an Example was calculated | required with the following method.

<Weight average molecular weight (Mw)>
Gel permeation chromatography (GPC, manufactured by Waters, detector RI: Waters, 2414, column: SHODEX, LF-G, LF-804) (column temperature 40 ° C., flow rate 1 mL / min, chloroform solvent) It calculated | required by the comparison with a polystyrene standard sample.

<Melting point (Tm)>
It calculated | required by DSC (DSC apparatus RDC220 by SII). A sample is weighed 5 to 6 mg, weighed into a nitrogen-sealed pan, charged in a DSC measuring section set at 30 ° C. that has been nitrogen-sealed in advance, and then heated to 250 ° C. at a rate of 10 ° C./min. did.

<Carboxylic acid value>
20 mL of a mixed solvent of chloroform / methanol = 7/3 was added to 0.5 g of the measurement target polymer, and the polymer was completely dissolved. Then, when 2 drops of ethanol solution of bromothymol blue / phenol red mixture was added as an indicator, yellow color was exhibited. Titration was performed with a 0.1N ethanolic potassium hydroxide solution, and the point at which the color changed from yellow to light purple was used as the end point to determine the carboxylic acid value of the polymer.

<Terminal carboxylic acid ratio and number of terminal functional groups>
¹ H-NMR of a sample obtained by reacting polylactic acid and succinic anhydride and a polylactic acid sample obtained from lactic acid and succinic anhydride (equipment: ECA500 manufactured by JEOL, internal standard tetramethylsilane: δ = 0 ppm) was measured. In this spectrum,
δ = 2.61 to 2.72 ppm (multiplet):
Succinic acid unit reacted with polylactic acid terminal and derived from methylene chain hydrogen of succinic acid in polylactic acid (4H)
δ = 4.36 ppm J = 6.92 (quartet):
Derived from methine hydrogen at α-position of polylactic acid chain terminal hydroxyl group (1H)

From the above two integral values,
The number of terminal carboxylic acids [= the number of polylactic acid carboxyl groups (= the number of unreacted polylactic acid terminal hydroxyl groups) + the number of succinylated terminal carboxyl groups] and the number of terminal hydroxyl groups (number of unreacted polylactic acid terminal hydroxyl groups) The rate was calculated. In addition, the number of terminal functional groups was calculated from the above-described carboxylic acid value and terminal carboxylic acid ratio.
Terminal carboxylic acid ratio (%) = number of terminal carboxylic acids / (number of terminal carboxylic acids + number of terminal hydroxyl groups) × 100
Number of terminal functional groups (mol / g) = Carboxylic acid value / (Terminal carboxylic acid ratio / 100)

<Identification of amide bond of polylactic acid resin>
¹³ C-NMR (apparatus: ECA500 manufactured by JEOL Ltd., internal standard chloroform-d: δ = 77 ppm) of a polylactic acid resin obtained by reacting polylactic acid and hexamethylene diisocyanate was measured. In this spectrum,
δ = 39 ppm:
From the α-position carbon of the hexamethylene unit adjacent to the amide bond From the above, the presence or absence of an amide bond in the polylactic acid resin was determined.

<Production Example 1: Production of polylactic acid unit a- 1 component>
Dean was charged with 500 parts by weight of 90% L-lactic acid (99.5% by mole of L-lactic acid) from Purac and 1.18 parts by weight of tin (II) chloride dihydrate (manufactured by Wako Pure Chemical Industries) as a reagent. A round bottom flask equipped with a Stark trap was charged. After the atmosphere in the flask was replaced with nitrogen, the temperature was raised to 130 ° C. with an oil bath heated to 150 ° C. under normal pressure and nitrogen atmosphere. The inside of the flask was gradually depressurized and held at 50 mmHg for 2 hours. Next, after releasing the inside of the flask to normal pressure, 40 parts by weight of xylene was added to the flask. The Dean Stark trap was then replaced with a Dean Stark trap filled with xylene. Next, the oil bath temperature was raised to 180 ° C., the pressure in the flask was reduced to 500 mmHg, and the reaction solution temperature was maintained at 150 ° C. for 20 hours to obtain transparent poly (L-lactic acid). With respect to the poly (L-lactic acid), the weight average molecular weight (Mw) was measured by the measurement method, and found to be 20000. Moreover, when the carboxylic acid value was calculated | required with the said measuring method, it was 1.818 * 10 < ^-4 > (mol / g).

Furthermore, 6.55 parts by weight of succinic anhydride was added to the flask, and the mixture was stirred at an oil bath temperature of 150 ° C. for 2 hours to convert the terminal hydroxyl group of the poly (L-lactic acid) into a carboxyl group. Lactic acid) was obtained. Thereafter, the inside of the flask was released to normal pressure, 300 parts by weight of xylene was added and diluted, and the resulting solution was extracted, and the xylene was air-dried under a nitrogen stream. It was washed twice with 2-propanol containing 1% of 35% hydrochloric acid, filtered, further washed several times with methanol, and dried under reduced pressure at 50 ° C. to obtain 340 wt. Of white polylactic acid unit a- 1 component. I got a part. It was 20000 when the weight average molecular weight (Mw) was measured by the said measuring method about the polylactic acid unit a- 1 component. With respect to the polylactic acid unit a- 1 component, the terminal carboxylic acid ratio was determined by the above measurement method and found to be 95%. Further, when the carboxylic acid value of the polylactic acid unit a-1 component was determined by the above measurement method, it was 3.652 × 10 ⁻⁴ (mol / g). The number average molecular weight Mn calculated from the carboxylic acid value and the terminal carboxylic acid ratio was 5200. The melting point (Tm) was 161 ° C.

<Production Example 2: Production of polylactic acid unit b- 1 component>
Polylactic acid unit as in Production Example 1 except that 90% L-lactic acid was changed to 90% D-lactic acid (hydrolyzed D-lactide manufactured by Purac, lactic acid having a D-form of 99.5 mol% or more). b- 1 component was obtained. It was 20000 when the weight average molecular weight (Mw) was measured by the said measuring method about the polylactic acid unit b- 1 component. With respect to the polylactic acid unit b- 1 component, the terminal carboxylic acid ratio was determined by the above measurement method and found to be 95%. Moreover, when the carboxylic acid value of the polylactic acid unit b- 1 component was determined by the above measurement method, it was 3.668 × 10 ⁻⁴ (mol / g). The number average molecular weight Mn calculated from the carboxylic acid value and the terminal carboxylic acid ratio was 5180. The melting point (Tm) was 160 ° C.

<Production Example 3: Production of polylactic acid resin (component A)>
A round bottom flask was charged with 75 parts by weight of the polylactic acid unit a- 1 component synthesized in Production Example 1, 75 parts by weight of the polylactic acid unit b- 1 component synthesized in Production Example 2, and 0.12 part by weight of magnesium stearate. . After replacing the inside of the flask with nitrogen, 150 parts by weight of tetralin was inserted, and the temperature was raised to 210 ° C. under normal pressure and nitrogen atmosphere. Next, 4.86 parts by weight of hexamethylene diisocyanate ( 1.05 equivalent of isocyanate group with respect to the terminal functional group) was added to the flask and reacted at 200 ° C. for 1 hour. By adding 0.750 parts by weight of PEP-36 (manufactured by ADEKA) and 0.750 parts by weight of Irganox 1010 (manufactured by Ciba Specialty Chemicals), 100 g of tetralin is added, the solution is cooled, and the precipitate is filtered and dried. 150 parts by weight of white powdered polylactic acid resin (component A) was obtained. With respect to the resin, the weight average molecular weight was measured by the above measurement method, which was 150,000. The amide bond content was confirmed by ¹³ C-NMR of the polylactic acid resin obtained by the above measurement method.

<Production Example 4: Production of poly L-lactic acid>
48.75 parts by weight of L-lactide (manufactured by Purac) and 1.25 parts by weight of D-lactide (manufactured by Purac) were added to the polymerization tank, and the system was purged with nitrogen, and then 0.05 parts by weight of stearyl alcohol, catalyst As a result, 25 × 10 ⁻³ parts by weight of tin octylate was added and polymerized at 190 ° C. for 2 hours to produce a polymer. This polymer was washed with 2-propanol containing 1% of 35% hydrochloric acid to remove the catalyst, and poly L-lactic acid was obtained. The obtained poly L-lactic acid had a weight average molecular weight of 100,000. The melting point (Tm) was 159 ° C.

<Production Example 5: Production of poly-D-lactic acid>
1.25 parts by weight of L-lactide (manufactured by Purac) and 48.75 parts by weight of D-lactide (manufactured by Purac) were added to the polymerization tank, the inside of the system was replaced with nitrogen, 0.05 parts by weight of stearyl alcohol, catalyst As a result, 25 × 10 ⁻³ parts by weight of tin octylate was added and polymerized at 190 ° C. for 2 hours to produce a polymer. This polymer was washed with 2-propanol containing 1% of 35% hydrochloric acid, the catalyst was removed, and poly-D-lactic acid was obtained. The obtained poly-D-lactic acid had a weight average molecular weight of 120,000. The melting point (Tm) was 156 ° C.

<Production Example 6: Production of polylactic acid 1>
100 parts by weight of the polylactic acid resin (component A) obtained in Production Example 3 is supplied to a vent type twin-screw extruder having a diameter of 30 mmφ [TEX30XSST manufactured by Nippon Steel Works, Ltd.], a cylinder temperature of 230 ° C., and a screw rotation speed Polylactic acid 1 was obtained by being melt-extruded and pelletized at 150 rpm, a discharge rate of 10 kg / h, and a vent pressure reduction degree of 3 kPa.

<Production Example 7: Production of polylactic acid 2>
100 parts by weight of the polylactic acid resin (component A) obtained in Production Example 3 and 1 part by weight of a carbodiimide compound (carbodilite HMV-8CA: manufactured by Nisshinbo Co., Ltd.), which is a terminal blocking agent (component B), have a diameter of 30 mmφ. Supplied to a vent type twin screw extruder [TEX30XSST manufactured by Nippon Steel Works, Ltd.], melt extruded at a cylinder temperature of 230 ° C., a screw rotation speed of 150 rpm, a discharge rate of 10 kg / h, and a vent pressure reduction degree of 3 kPa to be pelletized, and polylactic acid 2 was obtained.

<Production Example 8: Production of polylactic acid 3>
100 parts by weight of the poly-L-lactic acid obtained in Production Example 4 and 100 parts by weight of the poly-D-lactic acid obtained in Production Example 5 were mixed with a vent type twin screw extruder having a diameter of 30 mmφ [TEX30XSST manufactured by Nippon Steel Works, Ltd. The resulting mixture was melt-extruded and pelletized at a cylinder temperature of 230 ° C., a screw rotation speed of 150 rpm, a discharge rate of 10 kg / h, and a vent vacuum of 3 kPa to obtain polylactic acid 3.

Thermoformed products were produced by the methods shown in the following examples and comparative examples. Moreover, each value in an Example was calculated | required with the following method.
(1) Melting peak ratio of 195 ° C. or higher: Measured at a heating rate of 20 ° C./min under a nitrogen atmosphere using DSC, and the melting peak ratio (%) of 195 ° C. or higher is 195 ° C. or higher (high temperature ) And a melting peak area of 140 to 180 ° C. (low temperature).
R ₁₉₅ or more (%) = A ₁₉₅ or more / (A ₁₉₅ or more + A ₁₄₀ to ₁₈₀ ) × 100
R ₁₉₅ or higher: Ratio of melting peak at 195 ° C. or higher A ₁₉₅ or higher: melting peak area at 195 ° C. or higher A ₁₄₀ to ₁₈₀ : melting peak area at ₁₄₀ to ₁₈₀ ° C. (2) Moldability: observe the form of thermoformed product Was done.
(3) Hydrolysis resistance: Retention rate relative to the value before treatment of the molecular weight of polylactic acid after the extrusion-molded product was treated in a constant temperature and humidity chamber for 100 hours under conditions of 65 ° C. × 95% relative humidity It was evaluated with.

<Examples 1-2 and Comparative Examples 1-2>
Polylactic acid having the composition shown in Table 1 was dried at 90 ° C. for 5 hours, then supplied to an extruder hopper, melted at a melting temperature of 250 ° C., and passed through a 1 mm slit die on a rotary cooling drum having a surface temperature of 25 ° C. And then cooled rapidly to obtain a sheet having a thickness of 0.5 mm. Using these sheets, a tray-shaped mold having an opening of 56 mm × 121 mm × bottom of 38 mm × 102 mm and a depth of 20 mm was attached to an FC-1APA-W type vacuum pressure forming machine manufactured by Asano Laboratory, and the sheet was preheated in advance. After that, vacuum / pneumatic molding was performed. Table 1 shows the moldability and the evaluation results.

  As is apparent from the results in Table 1, a thermoformed product obtained from a specific polylactic acid has thermoformability equivalent to that of poly L-lactic acid that is generally put into practical use, and has heat resistance and water resistance. It can be seen that the degradability is greatly improved. Furthermore, it turns out that the further improvement of the hydrolysis resistance by including a terminal blocker is also acquired.

Claims (5)

Thermoformed product comprising a polylactic acid resin (component A) having an amide bond obtained by reacting at least a polylactic acid unit containing L-lactic acid as a main component and a polylactic acid unit containing D-lactic acid as a main component with polyisocyanate And
The polylactic acid unit containing L-lactic acid as a main component is composed of 90 to 100 mol% of L-lactic acid units and 0 to 10 mol% of D-lactic acid units and / or copolymerization component units other than lactic acid. Lactic acid unit,
The polylactic acid unit containing D-lactic acid as a main component is composed of 90 to 100 mol% of D-lactic acid units and 0 to 10 mol% of L-lactic acid units and / or copolymer component units other than lactic acid. Lactic acid unit,
Weight ratio of polylactic acid unit mainly composed of L-lactic acid and polylactic acid unit mainly composed of D-lactic acid in polylactic acid resin (component A) (polylactic acid unit mainly composed of L-lactic acid) / Polylactic acid unit having D-lactic acid as a main component) in the range of 10/90 to 90/10,
Each of the polylactic acid units is obtained by any of the following methods, and a thermoformed product in which the ratio of carboxyl groups in the terminal functional groups exceeds 50%;
(A) A method of directly polycondensing a dicarboxylic acid or an acid anhydride with either lactic acid as a raw material, either in the initial stage of polymerization, in the middle or in the latter stage,
(B) A method of adding an acid anhydride after ring-opening polymerization of L-lactide or D-lactide, which is a lactic acid cyclic dimer, using an initiator. The weight average molecular weight of each polylactic acid unit is in the range of 5000 to 100,000,
2. The thermoformed product according to claim 1, wherein the polylactic acid resin (component A) has a weight average molecular weight in the range of 80,000 to 500,000. The thermoformed product according to claim 1 or 2 , wherein the polyisocyanate is an aliphatic diisocyanate. The polylactic acid resin (component A) is characterized in that, in a differential scanning calorimeter (DSC) measurement, a ratio of a melting peak at 195 ° C. or higher is 70% or higher among melting peaks in a temperature rising process. The thermoformed product according to any one of 1 to 3 . The thermoforming product according to any one of claims 1 to 4, wherein the terminal blocking agent (component B) is contained in an amount of 0.01 to 5 parts by weight per 100 parts by weight of the polylactic acid resin (component A).