JP5641519B2 - Stereocomplex body and method for producing the same - Google Patents

Description

  The present invention belongs to the technical field of polymer compounds, and particularly relates to a stereocomplex having excellent heat resistance and a method for producing the same.

  In recent years, there has been a strong interest in global environmental problems, and there has been an active movement to reduce emissions of greenhouse gases that are the cause of global warming problems. In addition, there is a concern that the exhaustion of oil, which is a limited reserve resource, will become a serious shortage.

  In conventional polymers using petroleum as a raw material, the shortage of raw materials and the suppression of greenhouse gas generation at the consumption / disposal stage are important issues in the industry. Under such circumstances, polylactic acid using non-petroleum-based raw materials has been spotlighted.

  Lactic acid, which is a raw material for polylactic acid, can be obtained through lactic acid fermentation from agricultural crops, so there is no fear of depletion. In addition, since the carbon that constitutes lactic acid is carbon dioxide in the atmosphere fixed by plants, there is no effect on the total amount of carbon dioxide in the atmosphere even if polylactic acid is disposed of by incineration, etc. Can be considered. For this reason, active technological development is currently underway in various applications, and several products have been born.

  However, polylactic acid has a problem that it is easily deformed by heat because its intermolecular force is small due to its molecular structure.

  As a means for solving this problem, a stereocomplex crystal is obtained by mixing and molding poly (D-lactic acid) and poly (L-lactic acid) obtained by separately polymerizing optical isomers L-lactic acid and D-lactic acid, respectively. It is known that the heat resistance is improved (see, for example, Non-Patent Document 1).

  In addition, various attempts have been made for the purpose of improving the thermal properties (melting point, etc.), mechanical properties (strength, etc.) of stereocomplex crystals of poly (D-lactic acid) and poly (L-lactic acid). (See Patent Documents 1 to 3). The stereocomplex crystal is formed by complementarily filling poly (L-lactic acid) and poly (D-lactic acid) having different molecular chain spiral directions to form a complex.

  It has been reported that by forming a stereocomplex crystal, the melting point is increased by about 40 ° C. and heat resistance is improved as compared with a homocrystal.

  However, the attempts disclosed in these patent documents and non-patent documents are all directed to a stereocomplex body composed of poly (D-lactic acid) and poly (L-lactic acid), and a poly (D or L) -lactic acid block. There are almost no reports on stereocomplexes of polymers having polymer blocks other than poly (D or L) -lactic acid blocks.

JP 2006-241607 A JP 2008-248022 A JP 2008-163111 A

Takasaki, et. al. , Fiber Preprints (Annual Meeting) Japan, Vol. 56, no. 1 (2001). Page 67

  Then, this invention makes it a subject to provide the stereocomplex body which has a novel structure.

  As a result of intensive research conducted by the present inventors to solve the above-mentioned problems, a polymer having a homopolylactic acid block and a polyolefin block, a homopolylactic acid reverse to the homopolylactic acid and / or a reverse polymorphic acid to the homopolylactic acid, and the like. The inventors have found that a polymer having a homogeneous homopolylactic acid block and a polyolefin block can form a stereocomplex, thereby completing the present invention. In particular, the present invention relates to the following (1) to (5).

(1) A stereocomplex obtained from a polymer (A) having a poly (D-lactic acid) block and a polyolefin block, and a polymer (B) having a poly (L-lactic acid) block and a polyolefin block. body.

(2) Poly (D-lactic acid) -polyolefin obtained by polymerizing D-lactic acid and / or D-lactide in the presence of a functional polyolefin having a hydroxyl group at the molecular chain end. A block copolymer,
Poly (L-lactic acid) -polyolefin block copolymer obtained by polymerizing L-lactic acid and / or L-lactide in the presence of a functional polyolefin having a hydroxyl group at the molecular chain end. The stereocomplex body according to (1), which is a coalescence.

(3) The functional polyolefin is obtained by thermal decomposition of a polyolefin having at least one selected from the structural units represented by the following general formula (i) as a structural unit, and the average number of terminal vinylidene groups per molecule is 1 A functional polyolefin obtained by hydroxylating a terminal vinylidene group-containing polyolefin having a number average molecular weight (Mn) of 1,000 to 100,000 and a molecular weight distribution dispersity (Mw / Mw) of 3.0 or less. The stereocomplex body according to (2).

（但し、式中、Ｒ^１は、水素原子、−ＣＨ_３、−Ｃ_２Ｈ_５又は−ＣＨ_２ＣＨ（ＣＨ_３）_２を意味する。）

(However, in the formula, R ¹ represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) _2. )

(4) preparing a poly (D-lactic acid) -polyolefin block copolymer by polymerizing D-lactic acid and / or D-lactide in the presence of a functional polyolefin having a hydroxyl group at the molecular chain end; A step of preparing a poly (L-lactic acid) -polyolefin block copolymer by polymerizing L-lactic acid and / or L-lactide in the presence of a functional polyolefin having a hydroxyl group at the molecular chain terminal; D-lactic acid) -polyolefin block copolymer and the poly (L-lactic acid) -polyolefin block copolymer are mixed, and then the mixture is melted by heating and further crystallized by cooling. A method for producing a stereocomplex body.

(5) Further, as the step of obtaining the functional polyolefin, polypropylene, poly-1-butene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, propylene / 1-butene copolymer, and poly-4- A step of melting one or two or more polyolefins selected from the group consisting of methyl-1-pentene, thermally decomposing under reduced pressure while bubbling an inert gas, and subsequently hydroxylating the pyrolysis product; The manufacturing method according to (4).

  The stereocomplex provided by the present invention is presumed that the poly (D-lactic acid) block and the poly (L-lactic acid) block form a stereocomplex, and has excellent heat resistance due to the complex structure.

1H-NMR chart of iPP-OH obtained in Reference Example 1 1H-NMR chart of iPP-PLLA obtained in Reference Example 3 DSC chart showing results of Example 1 DSC chart showing results of Example 2

  Hereinafter, the present invention will be described in detail according to embodiments. In the present invention, the term “poly” includes the concept of “oligo”.

  The stereocomplex body according to the present invention comprises a polymer having a homopolylactic acid block and a polyolefin block, and a homopolylactic acid reversely asymmetric to the homopolylactic acid and / or a homopolylactic acid block and polyolefin block reversely asymmetric to the homopolylactic acid. (In some cases, it may further contain a homopolylactic acid that is asymmetric with the homopolylactic acid). Here, “homopolylactic acid” refers to a polymer obtained by polymerizing L-form or D-form having an optical purity of 97% or more, preferably 100%.

Specific examples of the stereocomplex body according to the present invention are as follows.
A polymer having a poly (D-lactic acid) block and a polyolefin block, and a stereocomplex obtained by mixing poly (L-lactic acid) (in some cases, poly (D-lactic acid) may be further mixed) .
A stereocomplex obtained by mixing poly (D-lactic acid) and a polymer having a poly (L-lactic acid) block and a polyolefin block (in some cases, poly (L-lactic acid) may be further mixed) ).
A stereocomplex obtained by mixing a polymer (A) having a poly (D-lactic acid) block and a polyolefin block and a polymer (B) having a poly (L-lactic acid) block and a polyolefin block (In some cases, poly (D-lactic acid) and / or poly (L-lactic acid) may be further mixed).
In the present invention, it is needless to say that polyolefins compatible with the stereo complex may be appropriately present together.

  Of these, the polymer (A) having a poly (D-lactic acid) block and a polyolefin block, and the polymer (B) having a poly (L-lactic acid) block and a polyolefin block, according to the present application, The configured stereo complex body will be described in detail below.

  The polymer (A) is not particularly limited, but the functional group having at least one selected from the group represented by the following general formula (i) as a constituent unit and having a hydroxyl group at the molecular chain terminal. A poly (D-lactic acid) -polyolefin block copolymer obtained by polymerizing D-lactic acid and / or D-lactide in the presence of a functional polyolefin is preferred.

  Further, the polymer (B) is not particularly limited, but the polymer (B) has at least one structural unit represented by the following general formula (i), and has a molecular chain terminal. A poly (L-lactic acid) -polyolefin block copolymer obtained by polymerizing L-lactic acid and / or L-lactide in the presence of a functional polyolefin having a hydroxyl group is preferred.

(In the formula (i), R ¹ represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ).

  As the functional polyolefin having at least one of the structural units represented by the above general formula (i) and having a hydroxyl group at the molecular chain end, Macromolecules, 28, 7793 (1995) has been proposed by the present inventors. Preferred are those obtained by hydroxylating terminal vinylidene group-containing polyolefins obtained using the reported highly controlled pyrolysis techniques.

  The polyolefin thermal decomposition product (terminal vinylidene group-containing polyolefin) obtained by the highly controlled thermal decomposition method is represented by the following general formula (ii), a polyolefin having vinylidene groups at both ends of the molecular chain, and the following general formula: It is a mixture of polyolefin represented by (iii) having a vinylidene group at one end of a molecular chain, and usually has a number average molecular weight (Mn) of 1000 to 100,000 and a dispersity (Mw / Mn) of 3.0 or less, 1 The average number of vinylidene groups per molecule is in the range of 1.5 to 1.9, and the property is that the stereoregularity of the raw material polyolefin before decomposition is maintained.

（上記一般式（ｉｉ）及び一般式（ｉｉｉ）において、各Ｒ^１は、それぞれ独立して、水素原子、−ＣＨ_３、−Ｃ_２Ｈ_５又は−ＣＨ_２ＣＨ（ＣＨ_３）_２を表し、ｍ及びｎは、それぞれ独立して、１０〜２０００の整数を表す。）

(In the above general formula (ii) and general formula (iii), each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ; m and n each independently represents an integer of 10 to 2000.)

  The number average molecular weight of the raw material polyolefin before decomposition is preferably in the range of 10,000 to 1,000,000, more preferably in the range of 50,000 to 700,000, and still more preferably in the range of 100,000 to 500,000. The weight average molecular weight is preferably in the range of 10,000 to 1,000,000, more preferably in the range of 200,000 to 800,000.

  As the thermal decomposition apparatus, an apparatus disclosed in Journal of Polymer Science: Polymer Chemistry Edition, 21, 703 (1983) can be used. In the reaction vessel of the Pyrex (R) glass pyrolysis device, for example, polypropylene is put, and under the reduced pressure, the molten polymer phase is vigorously bubbled with nitrogen gas to extract the volatile product, thereby suppressing the secondary reaction. While performing the thermal decomposition reaction at a predetermined temperature for a predetermined time. After completion of the thermal decomposition reaction, the residue in the reaction vessel is dissolved in hot xylene, filtered while hot, and then reprecipitated with alcohol for purification. The re-precipitate is collected by filtration and dried in vacuum to obtain a terminal vinylidene group-containing polypropylene.

  The thermal decomposition conditions are adjusted by predicting the molecular weight of the product from the molecular weight of the polyolefin before decomposition and the primary structure of the final target block copolymer, and taking into account the results of experiments conducted in advance. The thermal decomposition temperature is preferably in the range of 300 ° C to 450 ° C. If the temperature is lower than 300 ° C., the thermal decomposition reaction of the polyolefin may not proceed sufficiently, and if the temperature is higher than 450 ° C., the thermal decomposition product may deteriorate.

  The polyolefin to be thermally decomposed is not particularly limited, but polypropylene, poly 1-butene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, propylene / 1-butene copolymer, and poly 4-methyl-1-pentene is preferred.

  Further, the stereoregularity of the polyolefin is not particularly limited, and various polyolefins such as isotactic polypropylene, syndiotactic oligopropylene, and atactic polypropylene can be thermally decomposed. The copolymer such as an ethylene / propylene copolymer may be either a random copolymer or a block copolymer.

  Hydroxylation is achieved by hydroxylating the double bond of the terminal vinylidene group-containing polyolefin obtained according to the above method by an oxidation reaction following hydroboration. For example, tetrahydrofuran is first used as a solvent, and a boronation reagent is first added to hydroborate. As the boration reagent, 9-boranebicyclononane or borane-tetrahydrofuran complex can be used. When a hydrogen peroxide solution is added to the reaction solution after hydroboration to cause an oxidation reaction, a functional polyolefin is obtained. The average number of terminal hydroxy groups per molecule depends on the average number of vinylidene groups and is in the range of 1.5 to 1.9.

  The conditions for polymerizing lactic acid and / or lactide in the presence of the functional polyolefin obtained as described above are not particularly limited, and generally known conditions can be adopted. Specifically, a metal derivative is used as a polymerization catalyst.

  Methods using metal derivatives are suitable for ring-opening polymerization of lactide (see Macromolecules 2000, 33, 7395-7403 and Macromolecules 1999, 32, 4794-4801, etc.). Examples of the metal derivative acting as a catalyst include metal derivatives such as tin, zinc, lead, titanium, bismuth, zirconium, germanium, antimony, and aluminum. Trialkylaluminum is preferred, and triethylaluminum is more preferred because of its reactivity and fewer impurities generated.

  The reaction solvent can be used without limitation as long as it is a solvent that dissolves the lactone polymer and does not deactivate the enzyme, such as acetonitrile, 1,4-dioxane, tetrahydrofuran, isopropyl ether, toluene, and benzene.

  The polymerization temperature can be 30 to 150 ° C., but it is particularly preferably carried out within the range of 40 to 130 ° C. If it is lower than 30 ° C., the reaction rate becomes low, and if it exceeds 130 ° C., the reaction solution may boil.

  The progress of the reaction can be confirmed by qualitatively or quantitatively analyzing the product. Specific examples include gas chromatograph, liquid chromatograph, mass spectrometry, NMR, IR, UV-VIS, or a combination thereof. The molecular weight characteristics of the block copolymer to be produced can be measured by the GPC method, and the NMR and IR spectroscopic methods can be applied to the microstructure.

  After completion of the reaction, it can be purified by reprecipitation with a poor solvent of the product. After purification, it is usually preferable to dry under reduced pressure.

  The polymer (A) and the polymer (B) thus obtained usually have a number average molecular weight (Mn) in the range of 5,000 to 500,000, preferably in the range of 10,000 to 200,000. It is. The weight average molecular weight (Mw) is usually in the range of 5,000 to 500,000, preferably in the range of 10,000 to 300,000. Further, the dispersity (Mn / Mw) is usually in the range of 1 to 3, preferably in the range of 1 to 2.

  In addition, the polymer (A) or the polymer (B) obtained in this way is respectively a poly (D or L) -lactic acid-polyolefin block copolymer represented by the following general formula (iv): It is a mixture containing a poly (D or L) -lactic acid-polyolefin block copolymer represented by the following general formula (v).

（上記式（ｉｖ）及び（ｖ）において、各Ｒ^１は、それぞれ独立して、水素原子、−ＣＨ_３、−Ｃ_２Ｈ_５又は−ＣＨ_２ＣＨ（ＣＨ_３）_２を表し、ｍ及びｎは、それぞれ独立して、１０〜２０００の整数を表す。また、ｏ、ｐ、及びｑは、それぞれ独立して、１０〜２０００の整数を表す。）なお、式（ｉｖ）及び式（ｖ）において、＊は、Ｄ−乳酸若しくはＤ−ラクチドによる不斉炭素箇所（重合体（Ａ）の場合）又はＬ−乳酸若しくはＬ−ラクチドによる不斉炭素箇所（重合体（Ｂ）の場合）を意味する。

(In the above formulas (iv) and (v), each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ , m and n Each independently represents an integer of 10 to 2000. Further, o, p, and q each independently represents an integer of 10 to 2000.) In addition, the formula (iv) and the formula (v) In the above, * means an asymmetric carbon site by D-lactic acid or D-lactide (in the case of the polymer (A)) or an asymmetric carbon site by L-lactic acid or L-lactide (in the case of the polymer (B)). To do.

  The formation method of the stereo complex is not particularly limited, and a generally known method can be adopted. Specifically, for example, the powders of the polymer (A) and the polymer (B) are mixed, the mixture is melted by heating, and further cooled to be crystallized. In this case, a generally known melt-kneading apparatus such as a twin-screw extruder can be appropriately used. The melting / kneading temperature is preferably in the range of 210 to 260 ° C. If the melting / kneading temperature is less than 210 ° C, the formation of a stereocomplex may be insufficient, and if it exceeds 260 ° C, decomposition or coloring may occur.

  The stereocomplex body according to the present invention has excellent heat resistance (usually a melting point of 180 to 240 ° C., typically 190 to 230 ° C.), so that it can be obtained by a molding method such as injection molding, blow molding or inflation molding. Can be formed into various products.

  In addition, the use of the stereocomplex body according to the present invention is not particularly limited, and can be formed into various products such as films and sheets. In addition, the stereocomplex of the present invention exhibits extremely excellent compatibility when preparing a blend or alloy of polyolefin and poly-lactic acid. In particular, by adding to a blend of isotactic polypropylene and polylactic acid, these completely different polymers can be compatibilized.

  There is no restriction | limiting in particular in the usage method of the stereocomplex body of this invention as a compatibilizing agent. It is possible to prepare a blend by mixing the stereocomplex of the present invention, polylactic acid and polyolefin at an appropriate mixing ratio by melt mixing or the like. The compatibility can be evaluated by observing the cross section of the blend. For observation of the cross section, an apparatus or a method usually used in the field of polymer blends or alloys can be used. Specifically, it is preferable to observe a cross section of a sample obtained by eluting one of the blended polymers with a solvent.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In each example, the molecular weight measurement conditions and the NMR measurement conditions are as follows.

<Molecular weight measurement conditions>
Measuring device: GPC analyzer (HLC-8220GPC (manufactured by Tosoh Corporation))
Column: TOSOH TSKgel GMHXL, G3000HXL, G2000HXL
Flow rate: 1 mL / min
Solvent: THF
Solute concentration: 1 mg / ml
Standard material: Polystyrene Temperature: 40 ° C
<NMR>
Measuring apparatus: FT-NMR: JNM-GX400 (manufactured by JEOL Ltd.)
Solvent: CDCl ₃
<Method for measuring the number of terminal vinylidene groups>
The number of terminal vinylidene groups was measured by 13C-NMR and determined from the signal intensity of 21.5 ppm of terminal vinylidene group adjacent methyl carbon and 12.5 ppm of saturated terminal methyl carbon. For example, polypropylene having a terminal double bond (0.4 g), 1,2,4-trichlorobenzene (2.1 mL), deuterated benzene (0.7 mL), HMDS as a reference substance, and 120 mm in a 10 mm tube. Measured at ° C.

(Synthesis Example 1): Synthesis of Functional Polypropylene (iPP-OH) A lab-scale highly controlled pyrolysis apparatus having a maximum sample amount of 5 kg was used as the pyrolysis apparatus. 2 kg of commercially available isotactic polypropylene (Novatech PP (manufactured by Nippon Polypropylene Co., Ltd.), grade: EA9A, melt flow index (MFR): 0.5 g / 10 min) was charged into the reactor, and the system was purged with nitrogen to 2 mmHg. Under reduced pressure, the reactor was heated to 200 ° C. to melt. Thereafter, the reactor was submerged in a metal bath set at 390 ° C., and pyrolysis was performed. During the thermal decomposition, the inside of the system was kept at a reduced pressure of about 2 mmHg, a conducting capillary was introduced into the molten polymer, and stirring was performed by bubbling nitrogen gas discharged from the capillary. After 2 hours, the reactor was lifted from the metal bath, cooled to room temperature, the reaction system was brought to atmospheric pressure, the residue in the reactor was dissolved in hot xylene, and then added dropwise to methanol for reprecipitation purification. The obtained polymer had a yield of 96%, a number average molecular weight (Mn) of 35,000, a dispersity (Mw / Mn) of 2.9, and an average number of terminal double bonds per molecule (fTVD) of 1.7. there were.

  The reactor was charged with 20 g of polypropylene having a terminal double bond (Mn: 1000, Mw / Mn: 1.1, fTVD: 1.8) obtained by highly controlled pyrolysis as described above and 200 ml of tetrahydrofuran (THF). After substitution with nitrogen, 60 ml of borane-tetrahydrofuran complex (BH3-THF) in THF (1M) was added and heated under reflux for 5 hours. Thereafter, 60 ml of 5N aqueous sodium hydroxide solution was added in an ice bath, followed by 60 ml of 30% aqueous hydrogen peroxide solution, and heated under reflux for 12 hours. After the reaction, the reaction mixture was poured into methanol and purified by reprecipitation to obtain functional polypropylene (iPP-OH). FIG. 1 shows a 1H-NMR chart of iPP-OH. As is clear from FIG. 1, since no peak due to a double bond is observed, it can be seen that all terminal vinylidene groups have been converted to hydroxyl groups.

(Synthesis Example 2): Synthesis of Polymer (A) (iPP-PDLA) 0.1 g of the above functional polypropylene (Mn: 1000) was charged into a Schlenk tube, and after nitrogen substitution, dissolved by heating with 3 ml of toluene. After that, 0.2 ml of a triethylaluminum / toluene 1M solution was added, and after stirring for 10 minutes, 1 g of D-lactide was added, followed by stirring at 100 ° C. for 12 hours. After the reaction, 0.5 ml of 1N HCl aqueous solution was added as a stopper and purified by reprecipitation with 200 ml of methanol. As a result of analyzing the obtained copolymer using GPC, Mn was 9900 and Mw / Mn was 1.22.

(Synthesis Example 3): Synthesis of Polymer (B) (iPP-PLLA) 0.1 g of the above functional polypropylene (Mn: 1000) was charged into a Schlenk tube, and after nitrogen substitution, dissolved by heating with 3 ml of toluene. After that, 0.2 ml of a triethylaluminum / toluene 1M solution was added, and after stirring for 10 minutes, 1 g of L-lactide was added, followed by stirring at 100 ° C. for 12 hours. After the reaction, 0.5 ml of 1N HCl aqueous solution was added as a stopper and purified by reprecipitation with 200 ml of methanol. As a result of analyzing the obtained copolymer using GPC, Mn was 10900 and Mw / Mn was 1.26. FIG. 2 shows a 1H-NMR chart of iPP-PLLA obtained in Reference Example 3 (note that the same chart was applied to iPP-PDLA according to Reference Example 2).

(Synthesis Example 4): Synthesis of Polymer (A) (iPP-PDLA) and Polymer (B) (iPP-PLLA) In Synthesis Example 1, the molecular weight of 14,000 obtained by changing the thermal decomposition conditions When iPP-PDLA (poly-D lactic acid-iPP-poly-D lactic acid triblock copolymer was estimated using iPP-OH in the same manner as in Synthesis Example 2 and Synthesis Example 3, Mn = 15 , 1,000-14,000-15,000) and iPP-PLLA (poly-L lactic acid-iPP-poly-L lactic acid triblock copolymer, Mn = 16,000-14,000-16 , 000) was synthesized.

(Example 1): Preparation of stereocomplex body and melting point measurement 1
Put 2.5 mg of the polymer (A) obtained in Synthesis Example 2 and 2.5 mg of the polymer (B) obtained in Synthesis Example 3 into a dedicated aluminum pan, and use a differential scanning calorimeter (DSC6100) manufactured by Seiko Instruments Inc. The temperature was raised from room temperature to 250 ° C. at a rate of 10 ° C./min to melt. Subsequently, the stereocomplex body (iPP-scPLA) was formed and crystallized by cooling from 250 degreeC to -70 degreeC at 10 degree-C / min.

    Furthermore, differential scanning calorimetry (DSC) was performed by raising the temperature of the stereocomplex body from −70 ° C. to 250 ° C. at 10 ° C./min in the differential scanning calorimeter. For comparison, DSC measurement was similarly performed for iPP-PDLA, iPP-PLLA, and iPP-OH. FIG. 3 is a DSC chart showing these results. FIG. 3 shows that the stereocomplex of the present invention has a melting point of 202 ° C. and has good heat resistance.

(Example 2): Preparation of stereocomplex body and melting point measurement 2
As the polymer (A) and the polymer (B), a stereocomplex was formed and the melting point was measured using the same method as in Example 1 except that the polymer (A) and the polymer (B) were used. The results are shown in FIG. In FIG. 4, the endothermic peak at 158 ° C. in iPP-OH is derived from iPP crystal melting. The endothermic peaks at 171 ° C. and 155 ° C. of iPP-PLLA are derived from crystal melting of PLLA and iPP, respectively. The peak at 161 ° C. and the shoulder peak at 154 ° C. in iPP-PDLA are derived from the crystal melting of PDLA and iPP, respectively. On the other hand, in iPP-scPLA, the peak derived from the crystal melting of PDLA and PLLA almost disappeared, and a new endothermic peak appeared at 220 ° C. This is about 50 ° C. higher than the crystal melting of PDLA and PLLA, and is derived from the stereocomplex.

  Since the stereocomplex body according to the present invention has good heat resistance, it can be molded into various products by molding methods such as injection molding, blow molding and inflation molding.

  In addition, since the polymer constituting the stereocomplex body according to the present invention has a polyolefin block, it has excellent mechanical properties (tensile strength, bending strength, resistance to resistance) compared to a stereocomplex body made of only conventional polylactic acid. Impact) and can be applied to various applications.

Claims (3)

A polymer (A) having a poly (D-lactic acid) block and a polyolefin block;
A stereocomplex obtained from a polymer (B) having a poly (L-lactic acid) block and a polyolefin block ,
As the polyolefin block, the following general formula (ii) and the following general formula (iii) having a number average molecular weight (Mn) of 1,000 to 100,000 obtained by a thermal decomposition method of isotactic polyolefin.

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000. )
Using a functional polyolefin obtained by hydroxylating the terminal vinylidene group of the polyolefin represented by
Poly (D-lactic acid)-represented by the following general formula (iv), obtained by polymerizing D-lactic acid and / or D-lactide in the presence of the functional polyolefin. A polyolefin block copolymer and a poly (D-lactic acid) -polyolefin block copolymer represented by the following general formula (v):

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000,
o, p, and q each independently represent an integer of 10 to 2000;
* Represents an asymmetric carbon site by D-lactic acid or D-lactide. )
Poly (L-lactic acid)-represented by the following general formula (iv) obtained by polymerizing L-lactic acid and / or L-lactide in the presence of the functional polyolefin. A polyolefin block copolymer and a poly (L-lactic acid) -polyolefin block copolymer represented by the following general formula (v):

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000,
o, p, and q each independently represent an integer of 10 to 2000;
* Represents an asymmetric carbon site by L-lactic acid or L-lactide. ),
The polymer (A) and the polymer (B) are stereocomplex bodies each having a number average molecular weight (Mn) in the range of 5,000 to 200,000 . The functionalized polyolefin is, the average terminal vinylidene groups per molecule 1.5 to 1.9, the molecular weight distribution of dispersity (Mw / Mw) is terminal vinylidene group-containing polyolefin is 3.0 or less hydroxylate a functionalized polyolefin obtained Te, claim 1 stereocomplex body according. Preparing a poly (D-lactic acid) -polyolefin block copolymer by polymerizing D-lactic acid and / or D-lactide in the presence of a functional polyolefin having a hydroxyl group at the molecular chain terminal; A step of preparing a poly (L-lactic acid) -polyolefin block copolymer by polymerizing L-lactic acid and / or L-lactide in the presence of a functional polyolefin having a hydroxyl group, and the poly (D-lactic acid) ) - wherein the polyolefin block copolymer poly (L- lactic acid) - mixture of polyolefin block copolymer, then and a step of crystallizing by melted by heating the mixture, further cooling, stereo A method for producing a complex body ,
As the polyolefin block, the following general formula (ii) and the following general formula (iii) having a number average molecular weight (Mn) of 1,000 to 100,000 obtained by a thermal decomposition method of isotactic polyolefin.

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000. )
Using a functional polyolefin obtained by hydroxylating the terminal vinylidene group of the polyolefin represented by
The poly (D-lactic acid) -polyolefin block copolymer is represented by the following general formula (iv) obtained by polymerizing D-lactic acid and / or D-lactide in the presence of the functional polyolefin. A poly (D-lactic acid) -polyolefin block copolymer and a poly (D-lactic acid) -polyolefin block copolymer represented by the following general formula (v):

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000,
o, p, and q each independently represent an integer of 10 to 2000;
* Represents an asymmetric carbon site by D-lactic acid or D-lactide. )
The poly (L-lactic acid) -polyolefin block copolymer is represented by the following general formula (iv) obtained by polymerizing L-lactic acid and / or L-lactide in the presence of the functional polyolefin. A poly (L-lactic acid) -polyolefin block copolymer and a poly (L-lactic acid) -polyolefin block copolymer represented by the following general formula (v):

(In the formula , each R ¹ independently represents a hydrogen atom, —CH ₃ , —C ₂ H ₅ or —CH ₂ CH (CH ₃ ) ₂ ;
m and n each independently represents an integer of 10 to 2000,
o, p, and q each independently represent an integer of 10 to 2000;
* Represents an asymmetric carbon site by L-lactic acid or L-lactide. ),
The poly (D-lactic acid) -polyolefin block copolymer and the poly (L-lactic acid) -polyolefin block copolymer have a number average molecular weight (Mn) in the range of 5,000 to 200,000, respectively. Body manufacturing method .

Images