US20120016101A1 - Polylactide resin and preparation method thereof - Google Patents

Polylactide resin and preparation method thereof Download PDF

Info

Publication number
US20120016101A1
US20120016101A1 US13/148,367 US201013148367A US2012016101A1 US 20120016101 A1 US20120016101 A1 US 20120016101A1 US 201013148367 A US201013148367 A US 201013148367A US 2012016101 A1 US2012016101 A1 US 2012016101A1
Authority
US
United States
Prior art keywords
substituted
unsubstituted
polylactide resin
group
chemical formula
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/148,367
Other languages
English (en)
Inventor
Sung-Cheol Yoon
In-su Lee
Seong-Woo Kim
Seung-Young Park
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LG Chem Ltd
Original Assignee
LG Chem Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020090040123A external-priority patent/KR101183225B1/ko
Priority claimed from KR1020090072140A external-priority patent/KR101183226B1/ko
Application filed by LG Chem Ltd filed Critical LG Chem Ltd
Assigned to LG CHEM, LTD. reassignment LG CHEM, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KIM, SEONG-WOO, LEE, IN-SU, PARK, SEUNG-YOUNG, YOON, SUNG-CHEOL
Publication of US20120016101A1 publication Critical patent/US20120016101A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/12—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing organo-metallic compounds or metal hydrides
    • B01J31/122—Metal aryl or alkyl compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
    • B01J31/18—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms
    • B01J31/1805—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms the ligands containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/78—Preparation processes
    • C08G63/82—Preparation processes characterised by the catalyst used
    • C08G63/823—Preparation processes characterised by the catalyst used for the preparation of polylactones or polylactides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/78—Preparation processes
    • C08G63/82—Preparation processes characterised by the catalyst used
    • C08G63/85—Germanium, tin, lead, arsenic, antimony, bismuth, titanium, zirconium, hafnium, vanadium, niobium, tantalum, or compounds thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
    • B01J2531/02—Compositional aspects of complexes used, e.g. polynuclearity
    • B01J2531/0213—Complexes without C-metal linkages
    • B01J2531/0219—Bimetallic complexes, i.e. comprising one or more units of two metals, with metal-metal bonds but no all-metal (M)n rings, e.g. Cr2(OAc)4
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
    • B01J2531/20—Complexes comprising metals of Group II (IIA or IIB) as the central metal
    • B01J2531/26—Zinc
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
    • B01J2531/40—Complexes comprising metals of Group IV (IVA or IVB) as the central metal
    • B01J2531/42—Tin
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

  • the present invention relates to polylactide resins with improved properties, and a preparation process therefor. More specifically, the present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefor, and polylactide resin compositions including the same.
  • Polylactides are a type of resin including a repeating unit of the following General Formula. Unlike conventional petroleum-based resins, the polylactide resins, which are based on biomass, can utilize renewable resources, and their preparation generates less greenhouse gas, CO 2 , than the preparation of other conventional resins. Also, not only do they have eco-friendly attributes such as biodegradability by water and microorganisms when being buried, but they also possess suitable mechanical strength comparable to the conventional petroleum-based resins.
  • the polylactide resins have been used mainly for disposable packages/containers, coatings, foams, films/sheets, and fibers. Recently, more efforts have been made to enhance the properties of the polylactide resins by mixing them with conventional resins such as ABS, polycarbonate, or polypropylene, and then utilizing them in a semi-permanent use such as for exterior materials of cell phones or interior materials of vehicles.
  • conventional resins such as ABS, polycarbonate, or polypropylene
  • the polylactide resins tend to biodegrade in and of themselves due to factors such as the catalyst used in their preparation, moisture in the air, and the like, and up to now such drawbacks of their own properties have limited their application.
  • Previously known processes for preparing the polylactide resins involve either directly subjecting lactic acid to condensation polymerization or carrying out ring opening polymerization with lactide monomers in the presence of an organometallic catalyst.
  • the direct condensation polymerization can produce the polymer at a low cost but it is difficult for the resulting polymers to have a high molecular weight in terms of a weight average molecular weight of 100,000 or more, making it difficult to sufficiently ensure the physical and mechanical properties of the polylactide resins.
  • the ring opening polymerization of the lactide monomers entails a higher cost than the condensation polymerization since the lactide monomers should be prepared from lactic acid, but it can produce a polymer having a relatively high molecular weight and is advantageous in controlling the polymerization, and thus it is commercially used.
  • this catalyst not only promotes the ring opening polymerization, but also tends to accelerate the depolymerization at a conversion rate exceeding a certain level (see U.S. Pat. No. 5,142,023; Leenslag et al. Makromol. Chem. 1987, 188, 1809-1814; Witzke et al. Macromolecules 1997, 30, 7075-7085).
  • the polylactide resin prepared from the ring opening polymerization tends to have a decreased molecular weight, a broadened molecular weight distribution, and an increased amount of remaining monomers, all of which can have an undesirable effect on the polymer properties.
  • the ring opening polymerization using such catalyst can achieve only a limited level of conversion rate.
  • the ring opening polymerization of the lactide as described above is a reaction involving a thermodynamic equilibrium between the monomers and the polymer, wherein the conversion rate to the polylactide resin increases at the beginning as the polymerization time passes, but the reaction reaches some degree of equilibrium when the conversion rate no longer increases.
  • the resulting polylactide resin after the polymerization essentially contains a certain amount of the monomer therein.
  • the reaction temperature becomes higher, the amount of the monomer at the equilibrium state increases, while the reverse holds true as the reaction temperature is reduced.
  • the present invention is to provide an organometallic complex and a catalyst composition that can be preferably used as a catalyst in a ring opening polymerization of lactide monomers to produce a polylactide resin with enhanced properties such as mechanical properties, heat resistance, and hydrolysis resistance at a high conversion rate.
  • the present invention is to provide a process for preparing the organometallic complex.
  • the present invention is to provide a polylactide resin with a higher molecular weight and excellent mechanical properties, wherein the depolymerization or the decomposition in its use is also suppressed so that the resin shows better hydrolysis resistance and heat resistance.
  • the present invention is to further provide a process for preparing a polylactide resin, which uses the organometallic complex or the catalyst composition and makes it possible to produce the polylactide resin at a high conversion rate.
  • the present invention is to provide a polylactide resin composition including the polylactide.
  • FIG. 1 shows a 13 C NMR spectrum for the organometallic complex of Synthesis Example 2.
  • FIG. 2 shows curves plotting a change in the conversion rate to the polylactide resin as the ring opening polymerization time passes, in Examples 4 and 5 and Comparative Examples 1 and 2.
  • FIG. 3 shows curves plotting a change in the weight average molecular weight of the polylactide resin as the ring opening polymerization time passes, in Examples 4 and 5 and Comparative Examples 1 and 2.
  • FIG. 4 shows curves illustrating the results of thermal gravimetric analysis (TGA) for the polylactide resin as prepared in Examples 6 and 9 and Comparative Example 1.
  • organometallic complexes and catalyst compositions a method of producing the organometallic complexes, and polylactide resins and a process for preparing the same will be explained hereinafter.
  • the term “including” or “containing” refers to including some element (or component) without any limitation, and should not be construed as excluding addition of other elements (or components).
  • lactide monomer can be defined as follows. Typically, lactides can be classified into L-lactide consisting of L-lactic acid, D-lactide consisting of D-lactic acid, and meso-lactide consisting of an L-type and a D-type. Also, a mixture of L-lactide and D-lactide (50:50) is referred to as D,L-lactide or rac-lactide.
  • lactides the polymerization proceeding only with either of L-lactide and D-lactide that have a high level of optical purity is known to yield an L- or D-polylactide (PLLA or PDLA) with a high level of stereoregularity.
  • L- or D-polylactide PLLA or PDLA
  • Such polylactides have a faster crystallization rate and a higher crystallization degree than a polylactide having a low level of optical purity.
  • the term “lactide monomer” is defined to include all types of lactides regardless of the characteristic differences of lactides depending on their types and the characteristic differences of the polylactides as obtained therefrom.
  • polylactide resin is defined to comprehensively refer to a homopolymer or copolymer including a repeating unit represented by the following General Formula.
  • Such “polylactide resin” can be prepared by a process including a step of forming the following repeating unit by the ring opening polymerization of the “lactide monomer” as described above.
  • the polymer obtained after the completion of such ring opening polymerization and the formation of the following repeating unit can be referred to as the “polylactide resin.”
  • the category of the “lactide monomer” includes any types of lactides.
  • polylactide resin In the category of the polymer that can be referred to as the “polylactide resin”, all the polymers are included in any state after the completion of the ring opening polymerization and the formation of the repeating unit, for example, unpurified or purified polymers after the completion of the ring opening polymerization, the polymers contained in the liquid or solid resin composition prior to being molded into an article, or the polymers contained in plastics or woven materials after being molded into an article. Accordingly, in the entire specification, properties of the “polylactide resin” (such as acidity, weight average molecular weight, amount of the catalyst residue, or the like) can be defined by the properties of the polymer in any state after the completion of the ring opening polymerization and the formation of the repeating unit.
  • properties of the “polylactide resin” such as acidity, weight average molecular weight, amount of the catalyst residue, or the like
  • polylactide resin composition is defined to refer to any composition prior to or after a molding into an article, including one including the “polylactide resin” or one prepared therefrom.
  • polylactide resin composition not only a liquid or solid resin composition in the form of a master batch or a pellet before a molding into an article is included, but also plastics or woven materials after a molding into an article.
  • the present inventors found the following to complete the present invention: when a novel organometallic complex having a carbodiimide structure bonded with a specific substituent group, or a catalyst composition including a compound of the carbodiimide structure and a metal compound, is used as a catalyst in the ring opening polymerization of lactide monomers, it is possible to produce a polylactide resin at a high conversion rate, the polylactide resin having a molecular weight higher than any previously known polylactides and thereby having excellent mechanical properties and having improved hydrolysis resistance and improved heat resistance since the decomposition in use can be suppressed.
  • an organometallic complex of Chemical Formula 1 is provided according to an embodiment of the present invention.
  • n is an integer of 0 to 15
  • p is an integer of 0 to 2
  • a is 0 or 1
  • M is Sn or Zn
  • R 1 and R 3 are the same as or different from each other, and each of them is hydrogen, a substituted or unsubstituted C3 to C10 alkyl, a substituted or unsubstituted C3 to C10 cycloalkyl, or a substituted or unsubstituted C6 to C10 aryl
  • R 2 is a substituted or unsubstituted C3 to C10 alkylene, a substituted or unsubstituted C3 to C10 cycloalkylene, or a substituted or unsubstituted C6 to C10 arylene
  • each of X and Y is independently an alkoxy group or a carboxyl group.
  • a catalyst composition including a compound of Chemical Formula 2 and a compound of Chemical Formula 3 is provided according to other embodiments of the present invention:
  • n is an integer of 0 to 15
  • p is an integer of 0 to 2
  • M is Sn or Zn
  • R 1 and R 3 are the same as or different from each other, and each of them is hydrogen, a substituted or unsubstituted C3 to C10 alkyl, a substituted or unsubstituted C3 to C10 cycloalkyl, or a substituted or unsubstituted C6 to C10 aryl
  • R 2 is a substituted or unsubstituted C3 to C10 alkylene, a substituted or unsubstituted C3 to C10 cycloalkylene, or a substituted or unsubstituted C6 to C10 arylene
  • each of X and Y is independently an alkoxy group or a carboxyl group.
  • an organometallic complex of Chemical Formula 1 or a catalyst composition including the compounds of Chemical Formula 2 and Chemical Formula 3 can show an excellent level of polymerization activity when being used as a catalyst in the ring opening polymerization of the lactide monomer. Therefore, it has been found that a polylactide resin having a high molecular weight can be obtained through the ring opening polymerization even with using a reduced amount of the catalyst.
  • the catalyst reacts with an initiator having a hydroxy group or moisture to form a metal hydroxy compound or an alkoxide compound, which is actually used as catalytically active species.
  • the ring opening polymerization is promoted by the metal hydroxy compound or the alkoxide compound to produce a polylactide resin.
  • some compounds having a carboxylic acid group or a hydroxy group are left behind, involving the depolymerization or the decomposition of the polylactide resin (see Kowalski et al. Macromolecules 2000, 33, 7359-7370).
  • the depolymerization or the decomposition that occurs as an equilibrium reaction for the polymerization of the polylactide resin is triggered by a hydrolysis reaction caused either by the carboxylic acid or by the moisture and lactic acid contained in the lactide monomer, a back-biting reaction caused by the catalyst bonded to the end of the polymer chain, or a transesterification reaction between the polymer chains with the catalyst bonded at their end and the carboxylic acid.
  • the specific carbodiimide component contained in the organometallic complex of Chemical Formula 1 or the catalyst composition can be coupled with the moisture or the carboxylic acid so as to eliminate the same. Therefore, when the ring opening polymerization of the lactide monomer proceeds when using the organometallic complex or the catalyst composition in accordance with the embodiment of the present invention, the hydrolysis reaction or the transesterification reaction by the moisture or the carboxylic acid can be suppressed so that the depolymerization or the decomposition of the polylactide resin can be greatly reduced.
  • the organometallic complex or the catalyst composition according to the embodiment of the present invention shows excellent polymerization activity and inhibition effect against the depolymerization caused by the catalyst, making it possible to produce high-molecular weight polylactide resins at a high conversion rate.
  • the organometallic complex or the catalyst composition also acts to remove moisture or acids, and thus when being used to carry out the ring opening polymerization of the lactide monomer, it can produce a polylactide resin having a lower level of acidity and thereby the decomposition of the polylactide resin after the polymerization or during its use can also be greatly suppressed.
  • organometallic complex and the catalyst composition show excellent activity as a catalyst for the ring opening polymerization, using them even in a relatively small amount makes it possible to produce high-molecular weight polylactide resins while curbing the amount of catalyst residue to a low level.
  • the organometallic complex and the catalyst composition when using the organometallic complex and the catalyst composition, one can produce a polylactide resin at a high conversion rate, the polylactide resin having excellent properties suitable for a semi-permanent use, such as superior mechanical properties resulting from the high molecular weight, and excellent hydrolysis resistance or heat resistance resulting from lower acidity or a smaller amount of the catalyst residue.
  • the organometallic complex of Chemical Formula 1 or the compound of Chemical Formula 2 contained in the catalyst composition has a specific carbodiimide structure substituted with a C3 to C10 alkyl group, cycloalkyl group, alkylene group, or cycloalkylene group, or a C6 to C10 aryl group or arylene group at the position of R 1 to R 3 .
  • such specific carbodiimide structure of the compound of Chemical Formula 1 or Chemical Formula 2 allows the organometallic complex and the catalyst composition to show excellent polymerization activity while effectively removing the moisture or the acids contained in the resin, and thereby the polylactide resin with excellent properties can be produced at a high conversion rate.
  • organometallic complex of Chemical Formula 1 or the compound of Chemical Formula 2 one can use a compound wherein R 1 and R 3 are monovalent phenyl groups substituted with a C1 to C10 alkyl group, or a C3 to C10 alkyl group or cycloalkyl group, and R 2 is a divalent phenylene group substituted with a C1 to C10 alkyl group or a C3 to C10 alkylene group or cycloalkylene group.
  • the MX p Y 2-p attached to Chemical Formula 1, or the compound of Chemical Formula 3 can be a compound containing Sn or Zn, or any mixture of at least two of the foregoing compounds, and representative examples of such compound include tin(II) 2-ethylhexanoate (Sn(Oct) 2 ).
  • the organometallic complex of Chemical Formula 1 can be prepared by a process including a step of a reaction of the compounds of Chemical Formula 2 and Chemical Formula 3, as substantiated by the following examples.
  • a polylactide resin having acidity of 10 meq/kg or less and a weight average molecular weight of 100,000 to 1,000,000 is provided according to other embodiments of the present invention.
  • Such polylactide resin can have a weight average molecular weight higher than any other polylactide resins previously known in the art.
  • a high weight average molecular weight is due to the fact that the catalyst such as the organometallic complex has excellent polymerization activity and plays a role of suppressing the depolymerization.
  • No polylactide resin with a weight average molecular weight of as high as 1,000,000 has been disclosed or provided yet. Thanks to such a high weight average molecular weight, the polylactide resin according to the embodiment of the present invention possesses excellent mechanical properties such as tensile strength in comparison with the previously known polylactide resin, allowing semi-permanent use of the polylactide resin.
  • the polylactide resin can be prepared in the presence of a smaller amount of the catalyst to have a higher molecular weight, and it can also have its depolymerization or decomposition during or after the polymerization being suppressed. Accordingly, in the polylactide resin, the amount of the monomer and the catalyst remaining after the polymerization can be minimized so that the polymer can have even better mechanical properties and the decomposition in use caused by the monomer residue or the like can be suppressed and thereby the polymer shows superior hydrolysis resistance.
  • the acidity of the polylactide resin according to the embodiment of the present invention is lower than that of any other polylactide resins previously known in the art.
  • the decomposition of the polylactide resin or the decrease in its molecular weight can be suppressed so that the hydrolysis resistance or the heat resistance of the polylactide resin can be further enhanced.
  • the polylactide resins can maintain their mechanical or physical properties (e.g., tensile strength) at an excellent level.
  • a Sn-containing catalyst for the ring opening polymerization, some of which will inevitably remain in the resulting resin as prepared.
  • Such remaining catalyst can be coupled to the end of the polylactide resin and the resulting coupled product causes a transesterification reaction with a carboxylic acid, possibly leading to the decomposition of the polylactide resin or a decrease in the molecular weight thereof.
  • the polylactide resin according to the embodiment of the present invention shows lower acidity (e.g., a low content of carboxylic acid) and includes a reduced amount of the catalyst residue as mentioned above so that the decomposition of the polylactide resin or the decrease in the molecular weight thereof that is caused by the transesterification reaction can be suppressed, making it possible to achieve excellent decomposition resistance (hydrolysis resistance) or heat resistance.
  • the decrease in the molecular weight of the polylactide resin is suppressed and the occurrence of the monomers resulting from the decomposition of the resin is prevented, the mechanical and physical properties of the polylactide resin can be maintained at an excellent level.
  • the polylactide resin according to the embodiment of the present invention shows enhanced hydrolysis resistance and heat resistance, allowing its semi-permanent use for the exterior materials of cell phones or interior materials of vehicles.
  • the polylactide resin according to the embodiment of the present invention as described above can have acidity of 3 to 10 meq/kg or less and a weight average molecular weight of 200,000 to 1,000,000. Accordingly, the polylactide resin shows superior hydrolysis resistance and heat resistance in combination with further enhanced mechanical properties suitable for a semi-permanent use and can be prepared at an outstanding conversion rate by using the specific catalysts and the preparation process, which will be described hereinbelow.
  • the amount of the residue catalyst in the polylactide resin can be 15 ppm or less, preferably 10 ppm or less, and more preferably 7 ppm or less (e.g., 3-7 ppm).
  • the polylactide resin according to an embodiment of the present invention can be obtained by using the novel catalyst with excellent polymerization activity, and the residual catalyst may include such novel catalyst, i.e., the organometallic complex of Chemical Formula 1 or a mixture of the compounds of Chemical Formula 2 and Chemical Formula 3.
  • the polylactide resin can be obtained in the presence of a smaller amount of the catalyst to have a high molecular weight, and as a result of this, it can have a smaller amount of the catalyst residue such as 15 ppm or less, preferably 10 ppm or less, and more preferably 7 ppm or less.
  • the catalyst residue is present at such a small amount that the bonding of the catalyst residue to the end of the polylactide resin and its triggering of a back-biting reaction or a transesterification reaction can be suppressed, and thereby the decomposition of the polylactide resin or the decrease in the molecular weight thereof can be reduced. Therefore, the polylactide resin with the decreased amount of catalyst residue can maintain its mechanical properties at an excellent level, showing superior hydrolysis resistance and heat resistance.
  • the novel catalyst in particular the carbodiimide component corresponding to Chemical Formula 2, can be coupled with moisture or an acid to remove it and thereby curb the hydrolysis of the polylactide resin caused by moisture, the transesterification caused by acid (e.g., carboxylic acid), and other decomposition/depolymerization results of the polylactide resin.
  • the polylactide resin includes such carbodiimide component in the catalyst residue, the decomposition or the decrease in the molecular weight can be further suppressed, and thereby the resin shows more enhanced mechanical properties, hydrolysis resistance, and the like.
  • the polylactide resin according to the embodiment of the present invention can show a weight loss of less than 20 wt % when being heated from room temperature to 300° C. during thermal gravimetric analysis (TGA).
  • TGA thermal gravimetric analysis
  • the polylactide resin according to the present invention has a weight loss of less than 20 wt %, showing excellent hydrolysis resistance and heat resistance. Therefore, the polylactide resin can be utilized very appropriately in a semi-permanent use.
  • a process for preparing a polylactide resin by using the organometallic complex or the catalyst composition as described above is provided.
  • the preparation process can include carrying out ring opening polymerization with lactide monomers in the presence of an organometallic complex of Chemical Formula 1.
  • the preparation process can include carrying out ring opening polymerization with lactide monomers in the presence of compounds of Chemical Formula 2 and Chemical Formula 3.
  • the specific carbodiimide structure contained in the organometallic complex or the like may act to remove moisture or acids so as to prepare a polylactide resin having lower acidity. Further, the excellent activity of the organometallic complex may reduce the amount of catalyst residue present in the polylactide resin.
  • the preparation process of the polylactide resin can produce a polylactide resin having more enhanced hydrolysis resistance.
  • the lactide monomers can be prepared from lactic acid by typical methods.
  • the lactide monomers can be any types of lactides, for example, all sorts of lactides including L,L-lactide, D,L-lactide, and D,D-lactide.
  • the compounds of Chemical Formula 1 or Chemical Formula 2 can have a specific carbodiimide structure substituted with either a C3 to C10 alkyl group, cycloalkyl group, alkylene group, or cycloalkylene group, or a C6 to C10 aryl group or arylene group.
  • the above compound has excellent polymerization activity and at the same time can eliminate the moisture or the acid contained in the resin, making it possible to produce a polylactide resin with a higher molecular weight and lower acidity.
  • R 1 is a monovalent phenyl group substituted with a C1 to C10 alkyl group, or a C3 to C10 alkyl group or cycloalkyl group
  • R 2 is a divalent phenylene group substituted with a C1 to C10 alkyl group, or a C3 to C10 alkylene group or cycloalkylene group.
  • the MX p Y 2-p attached to Chemical Formula 1, or the compound of Chemical Formula 3 can be a Sn- or Zn-containing compound or a mixture of at least two of the foregoing compounds.
  • Representative examples of such compound-in include tin(II) 2-ethylhexanoate (Sn(Oct) 2 ).
  • organometallic complex of Chemical Formula 1 can be prepared by a process including a step of subjecting the compounds of Chemical Formula 2 and Chemical Formula 3 to a reaction, which will be substantiated by the following examples.
  • the organometallic complex of Chemical Formula 1 or the compounds of Chemical Formulae 2 and 3 contained in the catalyst composition can be added at a ratio of 0.001 to 0.1 mole with respect to 100 moles of the lactide monomers, respectively, to conduct the ring opening polymerization. If the addition ratio of the catalyst becomes extremely low, the polymerization activity would be undesirably insufficient. On the other hand, if the addition ratio of the catalyst becomes exceedingly high, the amount of the catalyst residue in the polylactide resin as produced would increase so much so as to bring about the decomposition or the decrease in the molecular weight of the polylactide due to the depolymerization such as a transesterification reaction.
  • the organometallic complex of Chemical Formula 1 in the preparation process of the polylactide resin, one can use either the organometallic complex of Chemical Formula 1 as a single catalyst or the catalyst composition including the compounds of Chemical Formula 2 and Chemical Formula 3 as a catalyst.
  • the organometallic complex in terms of a high molecular weight of the resin as obtained from the polymerization or the polymerization activity or the conversion rate to the resin, it is more preferable to use the organometallic complex as a single catalyst.
  • the compounds of Chemical Formula 2 and Chemical Formula 3 can be added either simultaneously or sequentially with an interval therebetween. Further, they can be added either before the addition of the lactide monomer or prior to the initiation of the polymerization within a certain time, or directly before the initiation of the polymerization. However, in order to allow the compounds of Chemical Formula 2 and Chemical Formula 3 to react to some extent and form a complex therebetween, it is preferable for the compounds of Chemical Formulae 2 and 3 to be simultaneously added at a predetermined time before the initiation of the polymerization and then to add the monomer to initiate the polymerization.
  • the ring opening polymerization can be carried out in the presence of an initiator including a compound with a hydroxyl group.
  • the initiator can play a role of reacting with a catalyst such as the organometallic complex or the catalyst composition to form an effective catalytic species and initiate the ring opening polymerization. Accordingly, using the initiator in combination with the catalyst can cause further improvement in the catalyst activity, thereby producing the polylactide resin at a higher conversion rate.
  • the initiator can take part in some of the depolymerization or the decomposition of the resin to play a role of controlling the molecular weight of the polylactide resin.
  • a compound having a hydroxy group As the initiator, one can use any compound having a hydroxy group, with no limitation. However, a compound having less than 8 carbon atoms can be vaporized at the temperature of the ring opening polymerization due to its low molecular weight, and this can hinder its involvement in the polymerization reaction. Therefore, a compound with a hydroxy group that can be preferably used as the initiator has at least 8 carbon atoms, preferably 8 to 15 carbon atoms, and more preferably 8 to 12 carbon atoms.
  • the initiator can be added at a ratio of 0.001 to 1 mole with respect to 100 moles of the lactide monomers. If the addition ratio of the initiator becomes extremely low, the molecular weight of the resin as obtained by the ring opening polymerization would be so high that subsequent processing can become difficult. If the addition ratio of the initiator becomes too high, the molecular weight of the resin can decrease.
  • the ring opening polymerization of the lactide monomer is preferable for the ring opening polymerization of the lactide monomer to be carried out as bulk polymerization substantially without using any solvent.
  • “without using any solvent” includes using a small amount of a solvent for dissolving the catalyst, for example less than at most 1 mL of a solvent per kilogram of the lactide monomer.
  • Conducting the ring opening polymerization in the form of bulk polymerization can eliminate a process for removing the solvent after the polymerization and avoid decomposition or loss of the resin in such a solvent elimination process. Further, the bulk polymerization makes it possible to obtain the polylactide resin at a high conversion rate and at a high yield.
  • the ring opening polymerization of the lactide monomers can be performed at a temperature of 120 to 200° C. for 0.5 to 8 hours, preferably 0.5 to 4 hours.
  • the catalyst with superior activity is used, the ring opening polymerization carried out even for a shorter period than known before can provide a polylactide resin with a high molecular weight at a high conversion rate.
  • the depolymerization or the decomposition of the resin can be preferably reduced.
  • the preparation process as described above it is possible to produce the polylactide resin having a high molecular weight and lower acidity and thus showing excellent mechanical properties, hydrolysis resistance, and heat resistance at a high conversion rate.
  • a polylactide resin composition including the polylactide resin described above is provided.
  • the polylactide resin composition includes the polylactide resin with excellent mechanical properties, hydrolysis resistance, and heat resistance, and thus demonstrates excellent physical and mechanical properties so that it can be preferably utilized in a semi-permanent use such as for packaging for electronics or interior materials for vehicles.
  • the polylactide resin composition can include the polylactide resin either alone or in combination with a polycarbonate resin, an ABS resin, or a polypropylene resin. However, in order to exhibit unique properties of the polylactide, the resin composition can include the polylactide resin in an amount of 40 wt % or more, preferably 60 wt % or more, and more preferably 80 wt % or more, based on the content of the total resins contained therein.
  • the polylactide resin composition can include various additives that have been contained in a range of conventional resin compositions.
  • the polylactide resin compositions can be produced either as liquid or solid resin compositions prior to molding into the end-product or as plastics or woven materials in their end-product state.
  • the resulting plastics or woven materials can be prepared by typical processes depending on the type of each product.
  • an organometallic complex and a catalyst composition that can produce a polylactide resin with enhanced properties such as mechanical properties, heat resistance, and hydrolysis resistance at a high conversion rate, and a method of producing the organometallic complex, can be provided according to the present invention.
  • the present invention can provide a polylactide resin having a high molecular weight and superior mechanical properties and at the same time showing better hydrolysis resistance and heat resistance due to the inhibition of the depolymerization or the decomposition in use, a process for preparing the polylactide resin at a high conversion rate by using the organometallic complex or the catalyst composition, and a polylactide resin composition including the polylactide resin.
  • the present invention can make a great contribution to enabling it to be used not only for disposable products such as food wrapping films, household item films, and sheets, but also for various types of goods requiring a semi-permanent use such as packaging for electronics or interior materials for vehicles.
  • the molecular weight of the polymer and the molecular weight distribution thereof were measured by gel permeation chromatography (GPC), using a polystyrene sample as a standard.
  • FIG. 1 is 13 C NMR spectrum of organometallic complex B.
  • three peaks for a carbonyl group are shown at ⁇ 188, 183, and 182 ppm, respectively.
  • the peak at ⁇ 183 ppm which is very sharp, can be assigned to the one corresponding to the Oct-H acid compound coupled with the compound of Chemical Formula 5.
  • the broad peak at ⁇ 188 ppm corresponds to the one for free Sn(Oct) 2 and the broad peak at ⁇ 182 ppm can be assigned to the one corresponding to the organometallic complex coordinated by the compound of Chemical Formula 5.
  • organometallic complex B After 2 g (13.8 mmol) of a lactide monomer and 0.2 mL of a toluene solution (conc. 3.5 mM) of organometallic complex B were put into a 30 ml vial, and an initiator with a hydroxy group such as 2-ethylhexyl lactate, dodecyl alcohol, octanol, or ethylhexyl alcohol was added to each of the vials at a ratio of 1/1000, 2/1000, or 4/1000 (mol/mol) against the lactide monomer, respectively, they reacted at a polymerization temperature of 180° C. for 2 hours. Then, the reaction was carried out in the same manner as Example 1. Table 1 shows the amount of the initiator as added, the conversion rate to the polylactide resin, and the weight average molecular weight.
  • an initiator with a hydroxy group such as 2-ethylhexyl lactate, dodec
  • Example 12 it was found that when the initiator with a hydroxy group was added, the polylactide resin could be obtained at an even higher conversion rate. Further, as the initiator was added more or as the initiator with a hydroxy group had a longer chain, the molecular weight of the polylactide resin decreased, ascertaining that the initiator can play a role of controlling the molecular weight.
  • the amount of the catalyst residue in the polylactide resin was measured by inductively coupled plasma emission spectroscopy. With this method, the amounts of the catalyst residue in the polylactide resins prepared in Examples 7, 9, and 10 were measured, and the results are shown in Table 2.
  • the polylactide resin prepared by the examples had a small amount of the catalyst residue in the order of 5 to 15 ppm.
  • Example 1 Example 2
  • Example 4 Example 5 Polymerization temperature (° C.) 140 160 140 160 Time Sn/monomer (mol/mol) (h) 1/20,000 1/20,000 1/20,000 1/20,000 Conversion rate 0.5 19.4 64.6 77.2 (%) 1 20.0 20.0 83.5 85.6 2 26.3 91.4 91.4 4 34.6 37.3 88.2 90.8 Mw(*10 ⁇ 3 Da) 0.5 71.9 470.0 626.0 1 70.9 49.0 711.0 684.0 2 61.0 821.0 670.0 4 139.0 124.9 892.0 614.0 Mw/Mn 0.5 1.3 1.5 1.8 1 1.2 1.5 1.7 1.8 2 1.3 2.0 2.0 4 1.5 1.4 1.9 1.9 1.9 1.9
  • the conversion rate to polylactide resin was very low, i.e., 50% or less, and the molecular weight of the polylactide resin was also low, at most 150,000 or less.
  • the polylactide resins of the examples have low acidity of 5 meq/kg or less, while the ones from the comparative examples have high acidity of 35 meq/kg or more.
  • Thermal gravimetric analysis was carried out in order to test heat stability for the polylactide resins obtained by 2 hour and a 4 hour polymerizations in Comparative Example 1, respectively, and the polylactide resins obtained from Examples 6 and 11. The results are shown in FIG. 4 .
  • the “Comp. Ex. 1-2” shows an analysis result for the polylactide resin obtained by 2 hour polymerization in Comparative Example 1
  • “Comp. Ex. 1-4” shows an analysis result for the polylactide resin obtained by 4 hour polymerization in Comparative Example 1.
  • the thermal gravimetric analysis was conducted with heating from room temperature to 400° C. at a heating rate of 10° C./min, and Mettler-Toledo TGA 851e equipment was used as TGA equipment.
  • the decomposition was minimized in the polylactide resins of the examples even when heating to about 300° C., and the resins showed a weight loss of less than 20 wt %.
  • the polylactide resins of the comparative examples showed a weight loss exceeding at least 30 wt % when heating to about 300° C.
  • the polylactide resin of the examples has hydrolysis resistance and heat resistance better than the one of the comparative examples and thereby can maintain excellent mechanical properties.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Polyesters Or Polycarbonates (AREA)
  • Biological Depolymerization Polymers (AREA)
US13/148,367 2009-02-09 2010-02-09 Polylactide resin and preparation method thereof Abandoned US20120016101A1 (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
KR10-2009-0010182 2009-02-09
KR20090010182 2009-02-09
KR10-2009-0040123 2009-05-08
KR1020090040123A KR101183225B1 (ko) 2009-05-08 2009-05-08 폴리락타이드 수지, 이의 제조 방법 및 이를 포함하는 폴리락타이드 수지 조성물
KR10-2009-0072140 2009-08-05
KR1020090072140A KR101183226B1 (ko) 2009-02-09 2009-08-05 유기 금속복합체, 촉매 조성물 및 폴리락타이드 수지의 제조 방법
PCT/KR2010/000793 WO2010090496A2 (ko) 2009-02-09 2010-02-09 폴리락타이드 수지 및 이의 제조 방법

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2010/000793 A-371-Of-International WO2010090496A2 (ko) 2009-02-09 2010-02-09 폴리락타이드 수지 및 이의 제조 방법

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US14/027,700 Division US9415382B2 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof
US14/027,604 Division US20140066645A1 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof

Publications (1)

Publication Number Publication Date
US20120016101A1 true US20120016101A1 (en) 2012-01-19

Family

ID=44951557

Family Applications (4)

Application Number Title Priority Date Filing Date
US13/148,367 Abandoned US20120016101A1 (en) 2009-02-09 2010-02-09 Polylactide resin and preparation method thereof
US14/027,604 Abandoned US20140066645A1 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof
US14/027,700 Active 2030-07-29 US9415382B2 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof
US14/027,673 Abandoned US20140018515A1 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof

Family Applications After (3)

Application Number Title Priority Date Filing Date
US14/027,604 Abandoned US20140066645A1 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof
US14/027,700 Active 2030-07-29 US9415382B2 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof
US14/027,673 Abandoned US20140018515A1 (en) 2009-02-09 2013-09-16 Polylactide resin and preparation method thereof

Country Status (4)

Country Link
US (4) US20120016101A1 (zh)
EP (1) EP2395009B1 (zh)
CN (1) CN102333785B (zh)
WO (1) WO2010090496A2 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9062147B2 (en) * 2011-06-07 2015-06-23 Lg Chem, Ltd. Lactide copolymer, a preparation method thereof, and a resin composition including the same

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101027163B1 (ko) 2009-12-18 2011-04-05 주식회사 엘지화학 폴리락타이드 수지, 이의 제조 방법 및 이를 포함하는 폴리락타이드 수지 조성물
DE202011110976U1 (de) * 2010-06-21 2017-11-27 Lg Chem. Ltd. Polylactidharz mit ausgezeichneter Wärmebeständigkeit
KR101560302B1 (ko) 2012-12-06 2015-10-14 주식회사 엘지화학 락타이드 공중합체, 이의 제조 방법 및 이를 포함하는 수지 조성물
CN114315789A (zh) * 2020-12-15 2022-04-12 江苏景宏新材料科技有限公司 一种l-丙交酯的制备方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3502722A (en) * 1960-05-24 1970-03-24 Bayer Ag Carbodiimides
US4321394A (en) * 1979-10-11 1982-03-23 Bayer Aktiengesellschaft Process for the production of addition compounds of carbodiimides and compounds containing hydroxyl groups
US20070073033A1 (en) * 2004-11-04 2007-03-29 Hiroyuki Sato Process for producing aliphatic polyester

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5142023A (en) 1992-01-24 1992-08-25 Cargill, Incorporated Continuous process for manufacture of lactide polymers with controlled optical purity
US5338822A (en) 1992-10-02 1994-08-16 Cargill, Incorporated Melt-stable lactide polymer composition and process for manufacture thereof
US5770682A (en) * 1995-07-25 1998-06-23 Shimadzu Corporation Method for producing polylactic acid
US6166169A (en) 1996-07-15 2000-12-26 Brussels Biotech Aliphatic polyesters and/or copolyesters and a process for the production thereof
JP3440915B2 (ja) * 2000-03-14 2003-08-25 東レ株式会社 ポリ乳酸樹脂および成形品
US7151155B2 (en) * 2001-04-17 2006-12-19 Union Carbide Chemicals & Plastics Technology Corporation Copolymers of cyclic esters and cyclic formals
TW200533693A (en) * 2003-11-05 2005-10-16 Kureha Chemical Ind Co Ltd Process for producing aliphatic polyester
CN1930211B (zh) * 2004-03-18 2011-07-13 株式会社吴羽 残留环酯少的脂族聚酯的制造方法
JP4596125B2 (ja) 2004-05-11 2010-12-08 東洋紡績株式会社 ポリ乳酸樹脂組成物及びそれを用いた成形品
TW200732417A (en) 2005-10-05 2007-09-01 Teijin Ltd Composition containing polylactic acid
BRPI0709274A2 (pt) * 2006-03-31 2011-07-12 Teijin Ltd composição, produto moldado, e, processo para fabricar uma composição
JP2008069271A (ja) 2006-09-14 2008-03-27 Teijin Ltd ポリラクチドの製造方法
JP5323312B2 (ja) * 2006-11-09 2013-10-23 帝人株式会社 ポリラクチドの製造方法
WO2008102919A1 (ja) * 2007-02-23 2008-08-28 Teijin Limited ポリ乳酸組成物
JP2008231285A (ja) 2007-03-22 2008-10-02 Toray Ind Inc 発泡体

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3502722A (en) * 1960-05-24 1970-03-24 Bayer Ag Carbodiimides
US4321394A (en) * 1979-10-11 1982-03-23 Bayer Aktiengesellschaft Process for the production of addition compounds of carbodiimides and compounds containing hydroxyl groups
US20070073033A1 (en) * 2004-11-04 2007-03-29 Hiroyuki Sato Process for producing aliphatic polyester

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9062147B2 (en) * 2011-06-07 2015-06-23 Lg Chem, Ltd. Lactide copolymer, a preparation method thereof, and a resin composition including the same

Also Published As

Publication number Publication date
US20140066645A1 (en) 2014-03-06
EP2395009A4 (en) 2013-08-14
WO2010090496A3 (ko) 2010-11-25
WO2010090496A2 (ko) 2010-08-12
EP2395009B1 (en) 2014-12-17
US20140018515A1 (en) 2014-01-16
US20140018516A1 (en) 2014-01-16
US9415382B2 (en) 2016-08-16
EP2395009A2 (en) 2011-12-14
CN102333785B (zh) 2015-06-10
CN102333785A (zh) 2012-01-25

Similar Documents

Publication Publication Date Title
US9115248B2 (en) Polylactide resin having excellent heat resistance and preparation method thereof
US9415382B2 (en) Polylactide resin and preparation method thereof
KR20120135890A (ko) 락타이드 공중합체, 이의 제조 방법 및 이를 포함하는 수지 조성물
KR101183226B1 (ko) 유기 금속복합체, 촉매 조성물 및 폴리락타이드 수지의 제조 방법
KR101183225B1 (ko) 폴리락타이드 수지, 이의 제조 방법 및 이를 포함하는 폴리락타이드 수지 조성물
KR101786841B1 (ko) 신규한 중합 촉매를 사용하여 폴리락티드를 제조하는 방법
KR101476378B1 (ko) 변성 폴리락타이드 수지 및 그 제조방법
US8779083B2 (en) Polylactide resin, method of preparing the same, and polylactide resin composition comprising the same
WO2014088321A1 (ko) 락타이드 공중합체, 이의 제조 방법 및 이를 포함하는 수지 조성물
KR101536269B1 (ko) 폴리락타이드 수지의 제조 방법
EP2937370A1 (en) Production method for polylactide resin
EP4335888A1 (en) Method for preparation of poly lactic acid polymer
KR101501683B1 (ko) 저산도를 갖는 폴리락타이드 수지의 제조 방법 및 이에 의해 제조된 폴리락타이드 수지
EP4108702A1 (en) Polylactide stereocomplex and preparation method therefor
KR20230022136A (ko) 생분해성 폴리(락트산-β-4-하이드록시부티레이트) 블록 공중합체 및 이를 포함하는 물품

Legal Events

Date Code Title Description
AS Assignment

Owner name: LG CHEM, LTD., KOREA, REPUBLIC OF

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YOON, SUNG-CHEOL;LEE, IN-SU;KIM, SEONG-WOO;AND OTHERS;REEL/FRAME:026737/0445

Effective date: 20110810

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION