WO2006048946A1

WO2006048946A1 - Biodegradable graft polymer and process for producing the same

Info

Publication number: WO2006048946A1
Application number: PCT/JP2004/016546
Authority: WO
Inventors: Mariko Yoshioka
Original assignee: Agri Future Joetsu Co., Ltd.
Priority date: 2004-11-08
Filing date: 2004-11-08
Publication date: 2006-05-11
Also published as: JPWO2006048946A1

Abstract

A cellulose derivative composite material which has thermoplasticity and excellent moldability and further has a characteristic layer structure and biodegradability. Cyclic esters comprising one or more lactones, e.g., ϵ-caprolactone, and/or one or more lactides as main components are mixed together in the presence of a hydroxylated cellulose derivative and an organic lamellar clay mineral. Tin octylate is added as a ring-opening polymerization catalyst to the resultant mixture to cause the esters to undergo ring-opening polymerization at a high efficiency. Thus, a polymer is produced which has functions such as satisfactory thermal stability, melt properties, gas-barrier properties, and biodegradability.

Description

Specification

Biodegradable graft polymer and production method thereof

Technical field

TECHNICAL FIELD [0001] The present invention relates to a biodegradable graft polymer of a composite material of a cellulose derivative and a method for producing the same.

Background art

[0002] Cellulosic materials are gaining increasing attention as the most mass-produced biomass materials on the earth and as biodegradable materials in the environment. Cell mouths have been widely used since ancient times by spinning cotton and linen produced in nature.

Since the 20th century, it has been used as a cellulose derivative. Currently, among the cellulose derivatives, cellulose acetate is the cheapest and has the largest industrial production. It has been used in photographic films, tobacco filters, and textiles for clothing. Most of them are molded in a solvent such as acetone and then evaporated.

[0003] However, the use of organic solvents such as acetone has an adverse effect on the environment! There is also a problem that a large amount of energy is required to recover the solvent, the productivity is low, and the cost is high. In contrast, melt processing has the advantages of low energy costs and high productivity.

In response, the plasticizer is added to the cellulose acetate, and then the thermoplasticity is increased and the melt processing is performed. Further research is ongoing in Japan. Studies are also underway to obtain thermoplastic coagulants in such a way that the graft reaction is directly modified to the cellulose derivative or the cellulose derivative species is handled in a wider range (for example, from Patent Document 1 to Patent Document 1). 7).

[0004] Among them, the method of performing in situ graft polymerization directly on a cellulose derivative is one of attractive methods. However, as described in Patent Document 1 to Patent Document 3, etc. A polymer obtained by ring-opening graft polymerization mainly comprising ε-force prolataton with respect to the acetyl acetate main chain and a production method thereof are known.

Patent Document 1: Japanese Patent Laid-Open No. 7-179662

Patent Document 2: JP-A-11 255801

Patent Document 3: Japanese Patent Laid-Open No. 11 255870

Patent Document 4: Japanese Unexamined Patent Publication No. 2003-82525

Patent Document 5: Japanese Patent Laid-Open No. 2003-238669

Patent Document 6: Japanese Unexamined Patent Publication No. 2003-335898

Patent Document 7: Japanese Patent Application Laid-Open No. 2004-10844

Disclosure of the invention

Problems to be solved by the invention

However, although there is no concern about bleed out in the polymer produced by the above-described method, the side chain flows at a temperature as low as about 60 ° C. because the introduced side chain mainly becomes poly force prolataton force. As a result, the thermal stability of the polymer material is problematic. In addition, as a general-purpose polymer, there is a problem of high cost in that a product is obtained by graft polymerization of cellulose acetate, which is a relatively high price.

The object of the present invention is to overcome the above-mentioned problems and to have good thermal stability and melting characteristics appropriate for a polymer material, and to achieve price absorption by providing functions such as gas permeation barrier and biodegradability. An object of the present invention is to provide a thermoplastic cellulose derivative composite material provided. Means for solving the problem

[0006] The above-mentioned problem of the present invention is that a layered clay mineral organized with an organic salt is added at the time of ring-opening graft polymerization of a cyclic ester mainly composed of ε-force prolatatone onto cellulose acetate. , Mixing well, proceeding to reaction to make a composite material, selecting organic salt species according to purpose, and selecting ε-force prolataton and lactide copolymerization according to purpose This can be solved by the thermoplastic cellulose derivative composite material obtained in this way.

The invention's effect [0007] According to the biodegradable graft polymer of the present invention, a cellulose derivative composite material having thermoplasticity, excellent molding processability and further biodegradability is provided.

BEST MODE FOR CARRYING OUT THE INVENTION

[0008] Examples of the cellulose derivative having a hydroxyl group used in the present invention include cellulose esters such as cellulose acetate acetate, cenololose acetate butyrate, cenololose acetate propionate, cellulose acetate phthalate, and cellulose nitrate, or the like. Examples include cellulose ethers such as ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose.

[0009] Among these cellulose derivatives having a hydroxyl group, since they are biodegradable, have good solubility in ratatones, are relatively inexpensive, and are easily available industrially, cellulose esters are used in the present invention. Cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferred because they are preferred to use and easier to handle. Among these, cellulose acetate having a acetyl group substitution degree of 1 to 13 is particularly preferable.

[0010] Examples of the cyclic ester used in the present invention include those capable of ring-opening polymerization: propylene-based rataton, δ-noratolataton, ε-force prolataton, α, α-dimethinole j8 —People piolaton, -ethyl-δ-valerolataton, α-methyl-ε-force prolatatone, j8-methyl-ε-force prolatataton, γ-methyl-ε-force prolatatone, 3, 3,5-trimethyl-ε- Ratatons such as force prolacton, 3,5,5-trimethyl-ε-force prolatatone, and enanthlactone, and ratatide.

In the present invention, the cyclic ester contains, as a main component, any one of such latatones and lactides, or a mixture containing a plurality of these in an arbitrary ratio. preferable. In particular, it is industrially available and is relatively inexpensive, and is compatible with cellulose esters such as cellulose acetate and ε-caprolatatone, lactide, which is excellent in compatibility, or ε-caprolataton and lactide mixed in any proportion. Is advantageous.

In the present invention, the ratio of the cellulose derivative having a hydroxyl group and the cyclic ester is not particularly limited. However, in general, a ratio of 85% by weight of a cellulose derivative having a hydroxyl group to 15% by weight of a cyclic ester 99 is desirable for graft polymerization. Has a hydroxyl group When the charging ratio of the cellulose derivative is larger than 85% by weight, the viscosity of the reaction system becomes remarkably high and handling becomes difficult. Further, when the charging ratio of the cellulose derivative having a hydroxyl group is less than 1% by weight, the productivity is lowered. When the viscosity is high, the reactive processing treatment included in the present invention is effective.

[0012] Nevertheless, when it is difficult to handle, the cellulose acetate as a third component and an organic solvent that does not have active hydrogen that is compatible with the cyclic ester, or a reactive polyhydric alcohol. It is possible to react by lowering the viscosity of the system to an easy-to-handle range.

[0013] The organically modified layered clay mineral used in the present invention is an organic material adsorbed or / and bonded to the interphase or / and surface of the layered clay mineral by a physical or chemical method (preferably a chemical method). Means what was done.

There are no particular restrictions on the striking layered clay minerals. Specifically, the smectite group such as montmorillonite, noiderite, sabonite and hectorite; the kaolinite group such as kaolinite and halosite; Bamikyrites such as Hederalba-Mikiyurites; Theolite, Tetralithic My Strength, Mascobite, Illite, Sericite, Fragobite, Biotite and other My Power.

These layered clay minerals may be natural minerals or synthetic minerals by hydrothermal synthesis, melting method, solid phase method, or the like. One of the above layered clay minerals may be used alone, or two or more of them may be used in combination. The layered clay mineral preferably has a cation exchange capacity of 30-300 meq / 100 g.

[0014] Further, organic organic salts are preferably used as organic substances adsorbed between the layers of these layered clay minerals. This organic humus salt is a layered clay mineral made from the cyclic esters (latatones and / or lactides) and cellulose acetate. Intercalation into, can increase their dispersion uniformity.

[0015] Specific examples of such organic salt include organic ammonium salt, organic phospho-um salt, organic pyridinium salt, and organic sulfo-um salt. . For example, the organic ammonium salt used in the present invention is NR + X— [4 R may be the same or different. Each represents a hydrogen atom or an alkyl group, and represents a counter ion]. Here, the number of carbon atoms of the organic salt (the total number of carbon atoms of four R) is preferably 6 or more. If the organic salt-um salt has a carbon number of less than 6, the interlayer distance of the layered clay mineral cannot be increased sufficiently, and the layered clay mineral is incorporated into cyclic esters (latatones or Z and lactide) and cellulose acetate. It tends to be difficult to evenly disperse or to inter-rate with them. Further, when R is an alkyl group, the alkyl group may contain a hydroxyl group as a substituent which may have a substituent.

Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a straight chain or a branched chain. Pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, straight Linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, straight chain Examples thereof include a chain or branched pentadecyl group and a linear or branched octadecyl group. In addition, the synthesis of an organic aluminum salt having a carbon number greater than that of the alkyl group tends to be difficult.

[0017] The organic salt-um salt has a force in which a chain of methylene groups having a functional group at the end as R is often present. The number of the chains is an integer of 6-22, preferably 8-18. If it is less than 6, the interlayer distance of the layered clay mineral is not sufficiently widened, and the dispersion uniformity of the layered clay mineral with cyclic esters (latatones or Z and lactide) and cellulose acetate is reduced. There is a tendency for the inter force rate to occur in the latter. On the other hand, if it exceeds 22, it tends to be difficult to synthesize organic alum salt. In the present invention, different organic onium salts can be used in combination.

[0018] The content of the organic salt is preferably 10 to 150 parts by weight, more preferably 20 to 100 parts by weight with respect to 100 parts by weight of the layered clay mineral. When the content of the organic salt is less than the lower limit, the interlayer distance of the layered clay mineral is not sufficiently increased, and the dispersion uniformity of the layered clay mineral with cyclic ester, lactide, cellulose acetate, and the like is increased. The tendency to decrease or the inter force rate to the latter of the former to happen On the other hand, if the above upper limit is exceeded, the amount of the organic sodium salt introduced by physical adsorption tends to increase, and the physical properties of the composite material finally obtained tend to be impaired (for example, excessive plasticization). It is in.

[0019] In addition, the interlayer distance of the layered clay mineral organicized with organic humic salt is preferably 2.9 or more, preferably 10 or more, based on the average distance between the center of gravity of each layer. More preferred. If the interlayer distance of the lamellar clay mineral is less than 2.9 mm, the dispersion uniformity of the lamellar clay mineral with cyclic esters, ratatoids, cellulose acetate, etc. will decrease.

[0020] As a catalyst used for polymerizing or graft polymerizing lactones and lactides in the presence of a cellulose derivative having a hydroxyl group, an organically modified lamellar clay mineral, etc., a usual ring-opening reaction of a cyclic ester is used. Catalysts used, ie, alkali metals such as sodium and lithium and derivatives thereof such as alkoxides; alkylaluminums and derivatives thereof typified by triethylaluminum, alkoxytitanium compounds typified by tetrabutyltitanate, tin octylate And organometallic compounds such as dibutyltin laurate; and metal halides such as tin chloride. Among them, a preferred U catalyst that can be used in the present invention is tin octylate.

In addition, by appropriately selecting the catalyst to be used and the reaction conditions, each can be subjected to single ring-opening graft polymerization or co-opening graft polymerization in the situation where latatones and lactide coexist. .

[0021] In the biodegradable graft polymer of the present invention, the ratio of the total amount of cellulose derivative having a hydroxyl group, cyclic ester (ratonone or / and lactide), catalyst to the amount of the organically modified layered clay mineral is the former. The latter is preferably 0.01-20 parts by weight with respect to 100 parts by weight, more preferably 0.05-10 parts by weight.

If the content of the organic layered clay mineral is less than the lower limit, the degree of improvement in physical properties such as rigidity tends to be insufficient. On the other hand, if the content exceeds the upper limit, the matrix resin becomes brittle. The impact strength may be significantly reduced.

[0022] (Production method)

Next, a cellulose derivative-based composite material that is a biodegradable graft polymer useful for the present invention The manufacturing method of the material will be explained.

The production method according to the present invention comprises an organicizing step in which an organic layered clay mineral is obtained by organicizing a layered clay mineral with an organic salt, an organic layered clay mineral and a cellulose derivative, a cyclic ester (Rataton). 3 and 4), and a step of stirring and mixing or melting and kneading at a sufficiently high temperature such as 100 to 200 ° C., and a step of polymerizing the mixed cyclic ester lactide. . However, in the following explanation, the organic layered clay mineral was purchased from three companies with their own characteristics, so the organicization process can be omitted.

[0023] That is, after the purchased organic layered clay mineral is added to cellulose acetate and cyclic ester (latatones or Z and lactide), the mixture is left to stand for a required time, stirred, or kneaded using a kneader. After the formation of a uniform state as much as possible, a catalyst for ring-opening polymerization of the cyclic ester is added, and the necessary heating is applied to proceed with polymerization to prepare a composite. As a result, in the case of a good combination, the cellulose derivative, the cyclic ester, and the organically modified layered clay mineral organized with the organic salt are sufficiently uniformly mixed, so that the heat resistance, moldability, and organically modified layered clay are mixed. A cellulose derivative composite material which is a biodegradable graft polymer according to the present invention having excellent mineral orientation can be easily and reliably obtained.

[0024] The temperature in the melt-kneading step without stirring and mixing is not particularly limited, but is preferably 100 to 200 ° C as described above. When the temperature is less than the lower limit, the cellulose acetate in contact with the cyclic ester is not sufficiently melted, and the organically layered clay mineral tends to be uniformly dispersed in the matrix resin. . On the other hand, when the temperature exceeds the upper limit, the molecular weight of the matrix resin decreases and physical properties of the cellulose derivative composite material tend to be impaired (for example, embrittlement).

[0025] The polymerization temperature for obtaining the polymer and further the graft polymer is usually a temperature applied to the ring-opening polymerization of the cyclic ester, and preferably 100 to 200 ° C. The reaction time varies depending on the type of cellulose derivative and cyclic ester having a hydroxyl group, the charging ratio, the type and amount of the catalyst, the reaction temperature, and the reaction apparatus, and there is no particular limitation. If you choose, one hour is enough. In particular, the biaxial etastruder When using a first-class reactive processing device together with a vacuum distillation recovery device for unreacted monomers to achieve nanocomposite composites and impart thermoplasticity, the reaction time is extremely short, such as 6 minutes or less. It is also possible to achieve the purpose.

[0026] In addition, when obtaining the biodegradable graft polymer of the present invention, it is desirable that the raw materials and reactors used be sufficiently dried. The water content of the reaction system should be 0.1% by weight or less, preferably 0.01% by weight or less, more preferably 0.001% by weight or less. The reaction product obtained in this way is based on the type of organic layered clay mineral, the molecular weight of the cellulose derivative having a hydroxyl group, and the force depending on the type of polymerization monomer of the cyclic ester (such as latatones or z and lactide). A cellulose acetate matrix resin obtained by grafting a cyclic ester containing lactide as a main component has a weight average molecular weight in the range of tens of thousands to two million.

[0027] These are those having molecular weights that satisfy the usual purpose of use. Further adjustment is possible in consideration of the amount of graft polymerization determined by the molecular weight of the raw material cellulose acetate and the amount of raw material blended above. . When a cellulose derivative having a hydroxyl group and a cyclic ester (latatones or Z and lactide) are included in the above-mentioned range of blending ratio, the average cellulose acetate graft polymer obtained by polymerization has a cyclic ester per glucose unit. 2-50, preferably 3-30, more preferably 4-20 moles. The graft polymer suitable for the molding process has a heat flow temperature of less than 180 ° C, in particular 60 to 175 ° C.

[0028] The reaction product according to the present invention may include a part of cellulose acetate and a graft polymer to organically modified layered clay mineral, and a homopolymer of unreacted cellulose derivative and cyclic ester. Compatibility of layered clay minerals and / or unreacted cellulose derivatives with homopolymers such as cyclic esters Even if not so good, the graft polymer acts as a mediator (compatibility agent), and the cyclic ester homopolymer It improves the miscibility of polymers and so on, resulting in an apparently uniform composite or matrix resin.

[0029] The cellulose derivative-based composite material thus obtained has sufficiently high dispersion uniformity of the cellulose derivative, the cyclic ester, and the organically modified layered clay mineral. Further, if an organic onium salt having a hydroxyl group is used, the water in the polymerization step is used. The acid group reacts with the cyclic ester, reacts with the cyclic ester as well as the polymer or oligomer force, and the cellulose derivative and the layered clay mineral are held more stably between the layers. The biodegradable graft polymer thus obtained can further improve heat resistance, moldability, and mold release properties.

[0030] By the way, by adding a cyclic ester, a plasticizing effect is recognized inside the cellulose derivative. This can lower the melting temperature of the product and increase the pyrolysis temperature. From this fact, it is possible to perform molding by molding means used for processing ordinary thermoplastic resin without adding a large amount of plasticizer, for example, injection molding, extrusion molding, press molding and the like. The cellulose derivative composite material, which is a biodegradable graft polymer according to the present invention internally plasticized by this cyclic ester, has a cellulose derivative biodegradable, and the grafted chemical species are respectively It is known that poly force prolatatatone and polylactic acid produced by polymerization, and copolymers of both are biodegradable. The matrix resin of the present invention has a feature of a polymer material in which a monomer that gives a biodegradable polymer is intentionally graft-polymerized to a cellulose derivative that is a biodegradable polymer.

[0031] Molded articles made of a cellulose derivative composite material in which an organically modified layered clay mineral is nano-dispersed in a matrix resin that has been internally plasticized by this cyclic ester include, for example, sheets, films, pipes, rods , Tools, tableware packaging, electronic parts, toys and other plastic materials that can be biodegradable and have excellent physical properties. It can be used as a plastic material for many general purpose applications.

[0032] Furthermore, the molded article using the cellulose derivative composite material which is the biodegradable graft polymer according to the present invention does not have the migration property of the external plasticizer. Conventionally, cellulose acetate molded products plasticized with phthalate esters such as dimethyl phthalate and jetyl phthalate, and other molded products made of methacrylic acid resin, polycarbonate resin, styrene resin, etc. When left in contact with high temperature and high humidity, other molded products such as methacrylic acid resin, polycarbonate resin, styrenic resin, etc. are markedly removed by the transferred phthalate ester. Crazing occurs. [0033] However, the molded article using the cellulose derivative composite material, which is the biodegradable graft polymer according to the present invention, can be used in combination with the other molded articles described above. It does not attack the molded product. In addition, in the case of a power cellulose derivative composite material in which various stabilizers are usually added to the resin molding material to prevent thermal deterioration and thermal coloring, the effect of the nanocomposite is not affected. They may be added in the required amount, alone or in combination. In addition, plasticizers, fillers, lubricants, antistatic agents, etc. may be added depending on the purpose.

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. The present invention is not limited to these examples or comparative examples. In the present invention, unless otherwise specified, “parts” and “%” in Examples and Comparative Examples indicate “parts by weight” and “% by weight”.

[0035] (Comparative Example 1)

Reactor equipped with stirrer, thermometer, reflux condenser (with drying tube at the top), 100 parts of dry cell mouth acetoacetate (manufactured by Daicel Engineering Co., Ltd., acetylation degree 55%, substitution degree 2.45), purification 400 parts of ε-force prolatatone was added, heated to 140 ° C, and gently stirred to dissolve the cellulose acetate uniformly. After stirring in a nitrogen atmosphere for 120 minutes in total, tin (II) octylate as a catalyst was added dropwise by 1% of the total amount of cellulose acetate and ε-force prolatatone, and initially stirring at 140 ° C The reaction was carried out for 30 minutes to obtain a product composed mainly of prolatatatone “graft” cellulose acetate (CL-g-CDA) equivalent to the matrix composite of the nanocomposite described later.

[0036] After completion of the reaction time, the reaction flask was lifted with an oil bath, and a large amount of dry nitrogen was blown into it. At the same time, a sufficient amount of acetone was added to dissolve the whole uniformly, and then centrifuged at 15000 rpm for 20 minutes. After separation, the acetone-insoluble residue was recovered, and the acetone-insoluble residue rate was determined to be 0.01%. Thereafter, the acetone-soluble material was concentrated to an appropriate concentration and then poured into a large excess of methanol to precipitate grafted cellulose acetate. The precipitate was collected by filtration using a 0.2 / zm membrane filter, further washed with a large amount of methanol, and collected by filtration to remove unreacted monomers and ε-caprolatatone homo-oligomer. The former amount of unreacted monomer was also confirmed to be very small chromatographically. Obtained graft cell The yield was determined by drying the rotacetate using a blow dryer and then a vacuum dryer for at least 24 hours, and the yield was 328.4%, and a large amount of grafted carpet of 228.4% weight was obtained. It was known that.

[0037] This product was subjected to GPC analysis using a tetrahydrofuran solvent and a developing agent. As a result, in terms of standard polystyrene, the starting cellulose diacetate is Mn57,000,

The ring-opening grafted cellulose acetate was Mwl56,000, whereas Mn was

128,000 and Mw force ¾12,000, confirming that the graft polymerization is proceeding remarkably. This graft cellulose cellulose acetate easily showed heat flow with a flow tester, and the heat flow temperature was 160 ° C.

[0038] A homopoly strength prolatatatone separately collected was mixed with the graft cellulose cellulose acetate, and then a flexible sheet having a thickness of 0.4 mm was formed using a hot press. A test piece (40x5x0.4 mm) was cut out from this sheet, and a dynamic viscoelasticity measuring device (manufactured by UBM)

Rheogel-E4000) was used to measure the temperature dependence of storage modulus. In this measurement, the measurement temperature range was 25-170 ° C, the heating rate was 3 ° C / min, the measurement frequency was 10Hz, and the measurement was performed in tensile mode. The data acquisition interval was 2 ° C.

[0039] The most important finding in the obtained measurement data is that the storage elastic modulus (Ε ') in the rubbery plateau region on the high temperature side is the lowest value compared to the data of the nanocomposites described later. In other words, the force varies at about 100 ° C or higher. These indicate that the thermal stability as a material is the worst.

[0040] (Comparative Example 2)

In a reactor equipped with a stirrer, thermometer, reflux condenser (with a drying tube at the top), 100 parts of absolutely dry cell mouth acetoacetate (Daiceli Gakugaku Co., Ltd., acetylation degree 55%, substitution degree 2.45), Weighed 25 parts of high purity purified natural montmorillonite PGW made by Nanocorln (5% of the total amount of the former two) with 400 parts of purified ε-force prolatatone, heated to 140 ° C, gently stirred, Cellulose acetate and PGW were uniformly dispersed and dissolved. After stirring for 120 minutes in total in a nitrogen atmosphere, stannous octoate (II) as a catalyst was added dropwise by 1% of the total amount of cellulose acetate and ε-caplat rataton, and initially stirred at 140 ° C. React for 30 minutes, force prolatathon 'graft' cellulose acetate / PGW (CL-g-CDA / PGW) A composite material was obtained.

[0041] During the preparation process, an X-ray diffraction intensity (XRD) curve of the PGW in the composite material finally obtained and the dry PGW used as a raw material was RINT 2200V manufactured by Rigaku Corporation. In order to cause intercalation in the mixing process of cellulose acetate and _ε -caprolataton and the latter polymerization process, no change was observed in the PGW interlayer spacing in the process of this composite material. Showed that some kind of organication is necessary for PGW. The same conclusion was obtained more clearly in the result of a similar study using Somasif®-100 (Copo Chemical Co., Ltd.) instead of PGW.

[0042] When the dynamic viscoelasticity was measured in the same manner as in Comparative Example 1, the storage modulus (Ε ') in the rubbery plateau region on the high temperature side was a small absolute value that approached the plot in Comparative Example 1. However, there was no variation in plots up to about 160 ° C, and the added PGW joined the soft matrix oils as a filler to maintain the aggregated structure. As a result, it was known that the thermal stability of the material was higher than that of Comparative Example 1.

[0043] (Example 1)

In a reactor equipped with a stirrer, thermometer, reflux condenser (with a drying tube at the top), 100 parts of absolutely dry cell mouth acetoacetate (Daiceli Gakugaku Co., Ltd., acetylation degree 55%, substitution degree 2.45), Organized with 400 parts of purified ε-force prolatatone and 25 parts (5% of the total amount of the former two) made by Corpo Chemical Co., Ltd. It was weighed as a layered clay mineral, heated to 140 ° C, stirred gently, and cellulose acetate and PGW were uniformly dispersed and dissolved. After stirring in a nitrogen atmosphere for 120 minutes in total, tin (II) octylate as a catalyst was added dropwise by 1% of the total amount of cellulose acetate and ε-force prolatatone, and initially stirred at 140 ° C while stirring 30 Reaction was carried out to obtain a force prolatatone 'graft' cellulose acetate / MEE (CL-g-CDA / MEE) composite material.

[0044] During this preparation process, an X-ray diffraction intensity (XRD) curve of the MEE in the composite material finally obtained and the dry MEE used as a raw material was RINT 2200V manufactured by Rigaku Denki Co., Ltd. As a result of measurement, it was found that MEE, which had a distance between bottom surfaces of 2.12 nm, was almost completely dispersed during the process of making this composite material, and was in an etaformed form. Synthetic fluorine mica system is considered to be difficult to insert between layers. It has a high compatibility and has an intercalation compound.

[0045] Hot-press molding of the main prolatatone graft 'cellulose acetate / MEE (CL-g-CDA / MEE) composite material yielded a flexible sheet having a thickness of 0.4 mm. A test piece (40 × 5 × 0.4 mm) was cut out from this sheet, and the temperature dependence of the storage elastic modulus was measured using a dynamic viscoelasticity measuring device (Rheoge® E4000 manufactured by UBM). In this measurement, the measurement temperature range was 25 ° C to 170 ° C, the heating rate was 3 ° C / min, the measurement frequency was 10Hz, and the measurement was performed in the tensile mode. The data acquisition interval was 2 ° C.

[0046] As a result, the value of the storage elastic modulus (値 ') in the rubbery plateau region on the high temperature side was the largest of all the composite materials used in this test, and in the case of the microcomposite of Comparative Example 2, It was one digit higher than the value obtained. There is no variability in the plot, and the added soot is larger in shape than the montmorillonite type and the force is almost completely dispersed (exfoliate). This is thought to be due to the ability to maintain a larger aggregated structure.

[Example 2]

Force Prolatatone Graft 'Cellulose Acetate / I- The same as in Example 1 except that Nanomart 30T manufactured by Nanocor Inc. was used as the organic layered clay mineral (no hydroxyl group contained in the organic salt between layers). A 30T (CL-g-CDA / I-30T) composite material was obtained.

In the course of this preparation, the X-ray diffraction intensity (XRD) curves of the final I-30T in the composite material and the absolutely dry I-30T used as an organized layered clay mineral were When measured using RINT 2200V manufactured by Co., Ltd.

I-30T, which was 2.61 nm, increased to 3.40 nm, and it was known that only intercalation due to intercalation was observed. This was confirmed and confirmed by transmission electron microscope (TEM) observation. The force present in the sheet in the form of lumps in I-30T. Their long axis is parallel to the surface of the film thickness, and it can be seen that it is affected by the flow during film formation.

[0048] (Example 3)

Force prolatatone graft cell according to Example 1 except that Corpo Chemical's Lucent SPN (an organic layer between layers-containing 1 hydroxyl group) is used as the organic layered clay mineral. Sose acetate / SPN (CL-g-CDA / SPN) composite material was obtained.

In the course of this preparation, the X-ray diffraction intensity (XRD) curve of the SPN in the composite material finally obtained and the completely dry SPN used as a raw material was measured using RINT 2200V manufactured by Rigaku Denki Co., Ltd. It was measured. It is known that SPN is almost dispersed during the process of this composite material, and is almost in the state of being etaformed.

[0049] When observed with a transmission electron microscope (TEM), the SPN is in a more dispersed state, but it is not separated into a single layer and exists in the sheet as an aggregate of multiple sheets. Then! Their major axes are parallel to the surface in terms of the thickness of the film, and it is recognized that they are affected by the flow during film formation.

The observation result that these multiple sheets are aggregated and oriented parallel to the sheet surface is the result of wide-angle and small-angle X-ray scattering images obtained by irradiating the X-ray beam perpendicularly to the sample sheet surface and wall surface [high flux beam It was supported by analyzing the line BL40XU (High Intensity Science Research Center).

[0050] (Example 4)

Force prolatatone 'graft' cellulose acetate / Cloisite according to Example 1 except that Cloisite 30B (Organic layer-containing two hydroxyl groups) is used as the organic layered clay mineral. 30B (CL-g-CDA / Cloisite 30B) composite material was obtained. In the course of this preparation, X-ray diffraction intensity (XRD) curves of Cloisite 30B in the final composite material and the completely dried Cloisite 30B used as raw materials were manufactured by Rigaku Corporation.

Measured using RINT 2200V. Cloisite 30B was known to disperse in the process of making it into a composite material and to become an etaformed.

[0051] Upon observation with a transmission electron microscope (TEM), it was found that SPN was separated into almost one layer and existed in the sheet. Their long axes exist without regularity in terms of the thickness of the film, and it is recognized that they dance during the flow during film formation. this is

It is thought that Cloisite 30B is separated to near a single layer and the mass is reduced.

This observation was supported by analyzing wide-angle and small-angle X-ray scattering photographs [High Flux Beamline BL40XU (High Intensity Science Research Center)] obtained by irradiating X-ray beams perpendicular to the sample sheet surface and the wall surface. . [Example 5]

Cellulose acetate, Lucentite SEN (containing two hydroxyl groups in the interlaminar organic salt) and ε-force prolatatone were kneaded and polymerized using Toyo Seiki Seisakusho Co., Ltd. . The feed ratio was supplied to the etastruder so that the charge ratio was 400 parts of ε-caprolatatone for 100 parts of cellulose diacetate (L-40) and 25 parts of SEN. That is, the cellulose diacetate and SEN mixture was weighed immediately before the experiment using a powder metering feeder, ε-force prolatatone, and tin octylate as a catalyst to 4 parts per 100 parts of cellulose diacetate. Then, the liquid was supplied to the etastruder by a liquid metering feeder using a feed pump. The reaction temperature was 140 ° C, and the reaction time (residence time) was 30 minutes. The reaction product comes out in the form of being discharged from the tip nozzle part of the etastruder, but the product was collected as a product after it was sufficiently quantified (in this experiment, 40 minutes after supplying the raw material ( It was sampled after obtaining a residence time of +10 minutes).

[0053] When the dynamic viscoelasticity was measured in the same manner as in Example 1, the value of the storage elastic modulus (で ') in the rubber-like plateau region on the high temperature side was the same as the plot of Comparative Example 1 and Example 1 The E 'value decreased from 120 ° C to 135 ° C and increased again. There is no variation in plots up to about 160 ° C, and the added PGW maintains the agglomerated structure by bonding the softened matrix resin together as a filler, thus improving the thermal stability of the material. It was known to be raised.

[Example 6]

The reaction composition obtained in Example 4 was hot-pressed into a sheet shape, and then a sheet cut out to a thickness of 0.4 mm and about 20 × 20 was used as a specimen. Composting machine pockets NS-1 with a volume of 20 liters and adjusted to 38 ° C (manufactured by Natural Kobo) contain sawdust and aerobic carbon-degrading bacteria (NS bacteria). First of all, on the first Saturday of the month, lkg of leftover food per day was put in and the operation was continued. Because of the degradation by aerobic bacteria, stirring in the device was performed once every 4 hours. In order to cope with this agitation, the small sheet-shaped test piece used was put into a metal or hard plastic net-like protective container and put into a test.

[0055] The composting test period is one month, and after that period, the specimen is removed and careful attention is paid. First, it was washed and lightly wiped with water, followed by preliminary drying in a 40 ° C blower dryer, followed by vacuum drying at room temperature for a whole day and weighing. The weight loss rate determined from the weight difference before and after composting was 25.6%. Specimen force that had a colorless, transparent and smooth surface before and after the composting process. This composting process resulted in a brownish color overall, and some parts became opaque and turbid. The surface also became uneven. Scanning electron microscopes also showed a large change in the surface condition, which was confirmed and confirmed by the fact that they were attacked by microorganisms by composting.

Claims

The scope of the claims

[I] A catalyst for ring-opening polymerization of this cyclic ester after mixing ratatones or a cyclic ester mainly composed of Z and lactide in the presence of a cellulose derivative having a hydroxyl group and an organic layered clay mineral. In addition, a biodegradable graft polymer obtained by ring-opening graft polymerization.

[2] The biodegradable graft polymer according to [1], wherein the Radon is subjected to single ring-opening graft polymerization.

[3] The biodegradable graft polymer according to [1], wherein the Raton and the lactide are subjected to co-opening graft polymerization.

4. The biodegradable graft polymer according to claim 1, wherein the ratatones are ε-force prolatatanes.

5. The biodegradable graph polymer according to claim 1, wherein the catalyst is tin octylate.

6. The biodegradable graft polymer according to claim 1, wherein the cellulose derivative having a hydroxyl group is a cellulose acetate having a degree of substitution of acetyl group of 1 to 13.

7. The biodegradable graphic polymer according to claim 1, wherein the cellulose derivative having a hydroxyl group is graft-polymerized with 2 to 50 mol of ε-caprolatatone per glucose unit.

[8] The biodegradable graft polymer according to any one of claims 1 to 7, which has a weight average molecular weight of 1 to 1 million.

[9] The biodegradable graft polymer according to any one of claims 1 to 7, wherein the heat flow temperature is 60 to 175 ° C.

[10] In the presence of a cellulose derivative having a hydroxyl group and an organically modified layered clay mineral, a catalyst for ring-opening polymerization of the cyclic ester is prepared after mixing with latatones or a cyclic ester mainly composed of Z and lactide. In addition, a method for producing a biodegradable graft polymer, comprising ring-opening graft polymerization.

[II] The method for producing a biodegradable graft polymer according to claim 10, wherein the ring-opening graft polymerization is carried out at a water content of the reaction system of 0.1% by weight or less. 12. The method for producing a biodegradable graft polymer according to claim 10 or 11, wherein the ring-opening graft polymerization is carried out using a biaxial etastruder.