WO2020241421A1 - BRANCHED CHAIN, ESTERIFIED α-1,3-GLUCAN DERIVATIVE - Google Patents

BRANCHED CHAIN, ESTERIFIED α-1,3-GLUCAN DERIVATIVE Download PDF

Info

Publication number
WO2020241421A1
WO2020241421A1 PCT/JP2020/019991 JP2020019991W WO2020241421A1 WO 2020241421 A1 WO2020241421 A1 WO 2020241421A1 JP 2020019991 W JP2020019991 W JP 2020019991W WO 2020241421 A1 WO2020241421 A1 WO 2020241421A1
Authority
WO
WIPO (PCT)
Prior art keywords
molding
glucan
esterified
glucan derivative
group
Prior art date
Application number
PCT/JP2020/019991
Other languages
French (fr)
Japanese (ja)
Inventor
忠久 岩田
木村　聡
裕哉 深田
Original Assignee
国立大学法人 東京大学
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
Application filed by 国立大学法人 東京大学 filed Critical 国立大学法人 東京大学
Priority to JP2021522271A priority Critical patent/JPWO2020241421A1/ja
Publication of WO2020241421A1 publication Critical patent/WO2020241421A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof

Definitions

  • the present invention relates to an ⁇ -1,3-glucan derivative introduced with a bi- or tri-branched ester chain.
  • bio-based plastics made from polysaccharides which are one of the natural polymers
  • the natural polysaccharides that have been used so far are cellulose ( ⁇ -1,4-glucan) and starch ( ⁇ -).
  • Plant-derived substances such as 1,4-glucan) and xylan ( ⁇ -1,4-xylan), and microorganisms such as curdlan ( ⁇ -1,3-glucan) and dextran ( ⁇ -1,6-glucan).
  • Such a polymer derived from a natural polysaccharide has greatly different physical properties as a polymer depending on the type of the derived sugar unit, the binding site, and the anomer.
  • ⁇ -1,3-glucan which is a polymer in which glucose is polymerized and bonded by an ⁇ -1,3-glycosidic bond
  • ⁇ -1,3-glucan exists as a structural polysaccharide on the cell wall of fungi and yeast, and is also produced by streptococci, which are oral streptococci.
  • the present inventors cloned the GtfJ gene, which is an ⁇ -1,3-glucan synthase derived from sucrose, and used the recombinant GtfJ enzyme obtained by utilizing the Escherichia coli expression system to linearize from sucrose. It has been reported that ⁇ -1,3-glucan can be synthesized (Patent Document 1). Furthermore, the present inventors have also found that by substituting the OH group in ⁇ -1,3-glucan with a linear saturated carboxylic acid, solubility and thermoplasticity in an organic solvent can be imparted. (Non-Patent Document 1). However, no synthetic example of a derivative in which a branched chain ester is introduced into an OH group in ⁇ -1,3-glucan has been reported, and elucidation of its thermal properties and mechanical properties is required.
  • the present inventors have surprisingly found that the ⁇ -1,3-glucan derivative introduced with a bifurcated or trifurcated ester chain is a conventional linear chain.
  • the film molded from the branched chain esterified ⁇ -1,3-glucan derivative has excellent physical properties such as thermal properties different from those of the derivative into which the ester chain has been introduced, and is excellent in heat resistance and thermoformability. It has been found that it has insulating properties and is suitable as an engineering plastic. Based on these new findings, the present invention has been completed.
  • each R is an acyl group having 4 to 20 carbon atoms having a bifurcated or trifurcated alkyl chain, which may be the same or different, and n is 100 to 20,000.) ;
  • ⁇ 3> The esterified ⁇ -1,3-glucan derivative according to ⁇ 1> or ⁇ 2> above, wherein the melting point is 250 to 340 ° C.
  • the glass transition temperature is in the range of 100 to 210 ° C.; ⁇ 4> The esterified ⁇ -1,3-glucan derivative according to ⁇ 3> above, wherein the glass transition temperature is 150 ° C. or higher and the difference between the melting point and the glass transition temperature is 110 ° C. or lower; ⁇ 5> The esterified ⁇ -1,3-glucan derivative according to any one of ⁇ 1> to ⁇ 4> above, wherein the viscosity is 50 kPa ⁇ s or less in the region of 200 to 280 ° C.
  • ⁇ 6> The esterified ⁇ -1,3-glucan derivative according to any one of ⁇ 1> to ⁇ 5> above, wherein the viscosity is 50 kPa ⁇ s or less in the region between the glass transition temperature and the melting point; ⁇ 7>
  • the invention ⁇ 9> A structure containing the esterified ⁇ -1,3-glucan derivative according to any one of ⁇ 1> to ⁇ 8>above; ⁇ 10> The structure is injection molding, compression molding, blow molding, inflation molding engel molding, extrusion molding, extrusion laminating molding, rotary molding, calendar molding, vacuum molding, stamping molding, spray-up molding, laminate molding, casting.
  • the structure according to ⁇ 9> above which is formed by a method, injection molding, manual stack molding, low pressure molding, transfer molding, foam molding, blow molding, or T-die method; ⁇ 11>
  • a bio-based plastic film or the like having excellent heat resistance and thermoforming properties and also having excellent mechanical properties. Materials can be provided. More specifically, in the ⁇ -1,3-glucan derivative introduced with the branched ester chain of the present invention, a higher glass transition temperature can be obtained and heat resistance is obtained as compared with the case where a linear ester having the same carbon number is introduced. You will get an improvement. In addition, since it exhibits thermal fluidity at a relatively low temperature, it can provide the effect of having excellent thermoformability in addition to improving thermal properties.
  • the melting point tends to decrease as the number of carbon atoms in the ester chain increases, whereas the branched ester chain of the present invention is used.
  • the introduced ⁇ -1,3-glucan derivative has the property of increasing the melting point by increasing the number of carbon atoms in the branched ester chain.
  • the esterified ⁇ -1,3-glucan derivative of the present invention can achieve both high heat resistance and excellent insulating properties, and is useful as a novel heat-resistant insulator.
  • FIG. 1 is a photograph of various cast films prepared from esterified ⁇ -1,3-glucan derivatives.
  • FIG. 2 is a graph showing UV-Vis spectra (transmittance) obtained for various cast films prepared from esterified ⁇ -1,3-glucan derivatives.
  • FIG. 3 is a graph in which the melting points (Tm) and glass transition temperature (Tg) of various esterified ⁇ -1,3-glucan derivatives are plotted for the number of carbon atoms in the acyl group R of the formula (1).
  • FIG. 4 is a graph showing the temperature dependence of the viscosity obtained by the capillary rheometer for various esterified ⁇ -1,3-glucan derivatives.
  • FIG. 5 is a graph showing the temperature dependence of the dielectric constants obtained for various esterified ⁇ -1,3-glucan derivatives.
  • the branched esterified ⁇ -1,3-glucan derivative according to the present invention has a structure in which glucose units are linearly polymerized by ⁇ -1,3-glycosidic bonds. , It is characterized by having a branched chain ester in the molecule as represented by the following formula (1).
  • the ⁇ -1,3-glucan derivative represented by the formula (1) is composed of an acyl group in which three hydroxyl groups (OH groups) in the glucose unit constituting the polymer have a bifurcated or trifurcated alkyl chain. It has a structure that has been esterified to form an OR group.
  • ⁇ -1,3-Glucan having an OH group (unesterified ⁇ -1,3-glucan) itself does not have thermoplasticity, but by performing such esterification, linear ⁇ -1,3- Thermoplasticity can be developed while retaining the structure of glucan. Therefore, by using the ester derivative, it can be used as a thermoplastic engineering plastic material whose shape can be freely changed by heat.
  • each R is an acyl group having 4 to 20 carbon atoms having a bifurcated or trifurcated alkyl chain, which may be the same or different, and preferably has a bifurcated or trifurcated alkyl chain. It is an acyl group having 4 to 12 carbon atoms.
  • Preferred examples of the acyl group having a bifurcated alkyl chain include, but are limited to, an isobutyryl group, an isovaleryl group, an isohexanoyl group, an isoheptanoyyl group, an isooctanoyl group, an isodecanoyl group, and an isostearoyl group. It's not a thing.
  • acyl group having a tri-branched alkyl chain examples include a pivaloyl group (tert-butylyl group), an acetyl tert-butylyl group, a propyl tert-butylyl group, and a butyryl tert-butylyl group.
  • the degree of substitution (DS) by the acyl group in R is in the range of 2.0 to 3.0, preferably in the range of 2.5 to 3.0.
  • the "degree of substitution” means the average number of hydroxyl groups substituted with the ester per glucose unit. That is, when the degree of substitution is 3, it means that all three Rs in the formula (1) are acyl groups, and all three OH groups in each glucose unit are esterified. If the degree of substitution is 1, one of the three OR groups in the formula (1) is esterified on average, and the remaining two ORs remain hydroxyl groups (that is, R is a hydrogen atom). Is shown.
  • the ester groups obtained by substituting the three OH groups (four OH groups in the terminal glucose unit) existing in each glucose unit of ⁇ -1,3-glucan may be the same or different. .. That is, in the ester group within each glucose unit, each R can be the same or different acyl group. For example, R can be randomly different ester groups, or a plurality of different ester groups can be obtained in a ratio of 2: 1 by controlling the esterification method.
  • N in the above formula (1) is 100 to 20,000, preferably 100 to 10,000.
  • the molecular weight of the esterified ⁇ -1,3-glucan derivative changes depending on the value of n, and the weight average molecular weight (Mw) of the ⁇ -1,3-glucan derivative is preferably 1. is 8 ⁇ 10 5 or more.
  • Such control of the molecular weight can be performed mainly by the type of synthase, reaction temperature, reaction time, use of a surfactant and the like when synthesizing ⁇ -1,3-glucan.
  • the degree of polydispersity (also referred to as PDI; or molecular weight distribution) represented by the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is preferably in the range of 2.0 to 3.0. Is.
  • Mw weight average molecular weight
  • Mn number average molecular weight
  • HPLC high performance liquid chromatography
  • SEC size exclusion chromatography
  • GPC gel permeation chromatography
  • the esterified ⁇ -1,3-glucan derivative of the present invention is characterized by having a structure in which glucose units are linearly polymerized by ⁇ -1,3-glycosidic bonds.
  • the ⁇ -1,3-glucan derivative has a completely linear structure.
  • “completely linear” means that the glucose unit constituting ⁇ -1,3-glucan does not have a branch other than the ⁇ -1,3-glycosidic bond (branch by glucose and other sugars). means.
  • a higher melting point tends to be obtained by increasing the number of carbon atoms of R in the above formula (1). This is in contrast to the fact that ⁇ -1,3-glucan derivatives introduced with a linear ester tend to have a lower melting point as the alkyl chain length is lengthened, and this is the first finding found in the present invention. Is.
  • the esterified ⁇ -1,3-glucan derivative of the present invention preferably has a glass transition temperature in the range of 100 to 210 ° C, more preferably 150 ° C or higher. Thereby, it is possible to have excellent heat resistance and thermoformability.
  • the esterified ⁇ -1,3-glucan derivative of the present invention can have a glass transition temperature of 150 ° C. or higher and a difference between the melting point and the glass transition temperature of 110 ° C. or lower.
  • the esterified ⁇ -1,3-glucan derivative of the present invention has a viscosity at a temperature (generally 350 ° C.) or lower at which decomposition of the ⁇ -1,3-glucan polymer occurs from the viewpoint of excellent thermoformability. It is preferable that it decreases and shows fluidity.
  • the esterified ⁇ -1,3-glucan derivative of the present invention has a viscosity of 50 kPa ⁇ s or less at any point in the region of 200 to 280 ° C.
  • the esterified ⁇ -1,3-glucan derivative of the present invention has a viscosity of 50 kPa ⁇ s or less at any point in the region between the glass transition temperature and the melting point.
  • the esterified ⁇ -1,3-glucan derivative of the present invention can have high insulating properties in addition to the above-mentioned excellent heat resistance. That is, the esterified ⁇ -1,3-glucan derivative of the present invention has a relative permittivity of 5.0 or less, preferably in the range of 2.0 to 4.5, and more preferably 2.5 to 3. It has a relative permittivity in the range of 0.8. Although not necessarily limited to this, in a particularly preferable embodiment, the esterified ⁇ -1,3-glucan derivative of the present invention has a glass transition temperature in the range of 100 to 210 ° C. and a relative permittivity. It can be in the range of 2.5 to 3.8.
  • the esterified ⁇ -1,3-glucan derivative of the present invention is an ⁇ -1,3-glucan having an OH group (unesterified ⁇ -1,3-glucan) using an esterification method known in the art.
  • the OH group of ⁇ -1,3-glucan can be converted to an ester group by reacting with a carboxylic acid anhydride having a desired branched alkyl chain in the presence of a base.
  • the OH group of ⁇ -1,3-glucan can be converted to an ester group by reacting with an organic acid having a desired branched alkyl chain and an acid anhydride in the presence of an acid catalyst.
  • the unesterified ⁇ -1,3-glucan as a raw material can be synthesized from sucrose using a known ⁇ -1,3-glucan synthase.
  • the ⁇ -1,3-glucan synthase is an enzyme capable of polymerizing glucose with an ⁇ -1,3-glycosidic bond while degrading sucrose, and is generally a glucan sucrase or glucosyl transferase (“Gtf” or “GtfJ”). ”) Also called.
  • an enzyme derived from Streptococcus salivarius disclosed in JP-A-2018-102249 can be used as such an ⁇ -1,3-glucan synthase.
  • the enzyme can be obtained by cloning the ⁇ -1,3-glucan synthase gene of caries bacterium, incorporating it into a plasmid vector such as Escherichia coli, and expressing it as a host.
  • the esterified ⁇ -1,3-glucan derivative of the present invention has both high heat resistance and excellent mechanical properties, a structure such as a film can be suitably produced by using the esterified ⁇ -1,3-glucan derivative.
  • the structure containing the esterified ⁇ -1,3-glucan derivative of the present invention can be molded by a method known in the art, for example, injection molding, compression molding, blow molding, inflation molding Engel molding. , Extrusion molding, extrusion laminating molding, rotary molding, calendar molding, vacuum molding, stamping molding, spray-up molding, laminate molding, casting method, injection molding, manual stack molding, low pressure molding, transfer molding, foam molding, blow molding, Alternatively, it can be molded by a method such as the T-die method.
  • the structure of the present invention is a film.
  • a method for producing a film from an esterified ⁇ -1,3-glucan derivative a method known in the art can be used.
  • a solution in which the ester derivative is dissolved in an appropriate organic solvent is applied.
  • the organic solvent include methylene chloride (dimethane), methanol, chloroform, tetrachloroethane, formic acid, acetic acid, bromoform, pyridine, dioxane, ethanol, acetone, alcohols, and aromatic compounds such as toluene, ethyl acetate and acetic acid.
  • Esters such as propyl, ethers such as tetrahydrofuran, methyl cellosolve, and ethylene glycol monomethyl ether, or combinations thereof can be used.
  • the film can also be molded by using a method such as spin coating or spraying.
  • the film can also be applied to the surface of the material by a hot melt method to bond the materials together.
  • the structure formed by the esterified ⁇ -1,3-glucan derivative of the present invention has excellent transparency.
  • a film having a thickness of about 0.05 to 0.2 mm can have a maximum transmittance of 60% or more.
  • the film of the present invention has an advantage of having transparency even in the ultraviolet region, and preferably has a transmittance of 40% or more at 300 nm.
  • the structure formed by the esterified ⁇ -1,3-glucan derivative of the present invention is It can preferably have a tensile strength of 10 MPa or more. In addition, it can have a breaking elongation of 5% or more and a Young's modulus of 0.10 GPa or more.
  • the mechanical properties can be controlled by adjusting the carbon number of R in the ester moiety. These physical properties can be measured by a method known in the art.
  • esterified ⁇ -1,3-glucan derivative of the present invention has high heat resistance and excellent thermoformability as described above, it can be applied to various plastic materials other than films. Furthermore, since the esterified ⁇ -1,3-glucan derivative of the present invention can also have high insulating properties, it can also be used as a heat-resistant insulator.
  • the unesterified ⁇ -1,3-glucan was synthesized by adding a recombinant glucosyl transferase (GtfJ enzyme) produced in Escherichia coli to a pH-adjusted sucrose solution in accordance with the disclosure of JP-A-2018-102249. ..
  • the obtained ⁇ -1,3-glucan was collected by filtration, washed with water, freeze-dried, and further dried in a vacuum dryer set at 105 ° C. for 3.5 hours.
  • ⁇ -1,3-glucan was esterified with various carboxylic acids.
  • 90 ml of acetic acid and 120 ml of trifluoroacetic anhydride (TFAA) were placed in an eggplant flask and stirred in an oil bath at 50 ° C for 5 minutes to mix.
  • Dry 3.0 g of ⁇ -1,3-glucan was added to the obtained mixed solution, and the mixture was stirred at 50 ° C. for 1 hour.
  • the recovered precipitate was dissolved in 100 ml of chloroform, reprecipitated in methanol, and recovered by filtration.
  • ester derivatives obtained by reacting with acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, isobutyric acid, isovaleric acid, isohexanoic acid, isoheptanic acid, and pivalic acid were used as ⁇ -1,3-glucan-Ac and ⁇ , respectively.
  • -1,3-glucan-Pr ⁇ -1,3-glucan-Bu, ⁇ -1,3-glucan-Va, ⁇ -1,3-glucan-Hex, ⁇ -1,3-glucan-iBu, ⁇ Notated as -1,3-glucan-iVa, ⁇ -1,3-glucan-iHex, ⁇ -1,3-glucan-iHep, ⁇ -1,3-glucan-Pi.
  • the molecular weight (Mw), polydispersity (Mw / Mn), and substitution degree (DS) calculated by GPC measurement for the synthesized esterified ⁇ -1,3-glucan derivative are shown in Table 2 below.
  • a film was prepared from the esterified ⁇ -1,3-glucan derivative obtained in Example 1 by a solvent casting method. 0.2 g of esterified ⁇ -1,3-glucan derivative was dissolved in 2 ml of dichloromethane and poured into a Teflon petri dish about 5.4 cm in diameter. The linear ester derivative was allowed to stand at room temperature for 3 days, and the branched ester derivative was allowed to stand on a hot plate at 40 ° C. for 1 hour to completely volatilize the solvent. As shown in FIG. 1, the obtained film was highly transparent in the entire visible light region.
  • the UV-Vis spectra obtained for various cast films are shown in FIG. Table 3 shows the film thickness and the maximum light transmittance in the visible light range (450-760 nm).
  • the esterified ⁇ -1,3-glucan derivative had relatively high transparency and showed the same transparency as polyethylene terephthalate and polyethylene.
  • polyethylene terephthalate has an aromatic ring, so that the transmittance is remarkably lowered, but it was found that the esterified ⁇ -1,3-glucan derivative also has a high transmittance in the ultraviolet region.
  • Thermogravimetric analysis (TGA) TGA-50 (Shimadzu Corporation) was used for the measurement.
  • the sample weight was about 2 mg.
  • the measurement was performed at a temperature range of 30 ° C-500 ° C, a heating rate of 20 ° C / min, and a nitrogen flow rate of 50 ml / s.
  • TGA Thermogravimetric analysis
  • Table 4 shows the temperatures (Td.5%, Td.50%) when the sample weight loss rate calculated from the TGA thermograms obtained for the esterified ⁇ -1,3-glucan derivative was 5% and 50%. Shown in.
  • ⁇ -1,3-glucan-Hex improved the thermal decomposition temperature by about 50 ° C
  • other ⁇ -1,3-glucan ester derivatives improved by about 90 ° C. This result is considered to indicate that the production of levoglucosan was suppressed and the thermal decomposition temperature was improved by substituting the hydroxyl group of ⁇ -1,3-glucan with an ester group.
  • DSC8500 (PerkinElmer) was used for differential scanning calorimetry. A cast film was used as the sample, and the weight was about 3 mg. After each sample was held at an isothermal temperature for 10 or 20 minutes, the melting point was evaluated in the heating process (1st run) from -30 ° C to 380 ° C. The heating rate was 20 ° C / min.
  • Holding temperature is 260 ° C for ⁇ -1,3-glucan-Ac, 250 ° C for ⁇ -1,3-glucan-Pr, ⁇ -1,3-glucan-Bu and ⁇ -1,3-glucan-Va
  • ⁇ -1,3-glucan-Hex is 200 ° C
  • ⁇ -1,3-glucan-iBu is 240 ° C
  • ⁇ -1,3-glucan-iVa and ⁇ -1,3-glucan -iHex and ⁇ -1,3-glucan-iHep were set to 280 ° C.
  • the melting point of ⁇ -1,3-glucan-Pi could be observed without heat treatment, it was not heat-treated. The measurement was carried out in a nitrogen atmosphere, and an empty aluminum pan was used as a control substance.
  • D-VA200S (IT measurement control) was used for dynamic viscoelasticity measurement.
  • a cast film with a thickness of 0.6 mm-1.0 mm was cut into a sample with a length of 7 mm and a width of 5 mm.
  • the conditions were shear mode, the temperature range was 30 ° C-380 ° C, the rate of temperature rise was 2 ° C / min, and the measurement frequency was 10 Hz.
  • Tm melting points
  • Tg glass transition points
  • the branched esterified ⁇ -1,3-glucan derivatives of the present invention ⁇ -1,3-glucan-iBu and ⁇ -1,3-glucan-Pi, have a high glass transition point exceeding 200 ° C. It was found that the temperature and the difference between the melting point and the glass transition point were within 100 ° C. It was also found that in the branched esterified ⁇ -1,3-glucan derivative of the present invention, the melting point tends to increase as the number of carbon atoms in the side chain increases. It was also found that the glass transition point decreases as the number of carbon atoms in the side chain increases, but stops decreasing at some point.
  • the increase in melting point due to the increase in side chain length is a specific behavior for a polysaccharide ester derivative. It is considered that the crystals are more densely constructed as the cause of the increase in the melting point. However, it is considered that the value of the exothermic enthalpy ⁇ H derived from the melting point decreases as the side chain becomes longer, and the crystallinity decreases. The decrease in the glass transition point is considered to be due to the decrease in the intermolecular cohesive force in the amorphous region.
  • the ⁇ -1,3-glucan derivative introduced with the linear ester tends to have a contrasting tendency that the melting point decreases as the side chain becomes longer. It was also found that the glass transition point tends to decrease almost linearly as the side chain becomes longer. It is considered that this is because the introduction of a long side chain increases the distance between the main chains and reduces the intermolecular cohesive force.
  • the branched esterified ⁇ -1,3-glucan derivative of the present invention showed a higher melting point than the linear ester derivative having a side chain having the same carbon number.
  • the branched esterified ⁇ -1,3-glucan derivative of the present invention showed a higher value than the linear ester derivative having a side chain having the same carbon number.
  • ⁇ -1,3-glucan-iBu has Tm of 257 ° C and Tg of 206 ° C
  • ⁇ -1,3-glucan-Pi has Tm of 307 ° C and Tg of 202 ° C.
  • the melt viscosity was measured with a capillary rheometer. CFT-500EX (Shimadzu Corporation) was used for the measurement. Samples include ⁇ -1,3-glucan-Ac, ⁇ -1,3-glucan-Pr, ⁇ -1,3-glucan-Bu, ⁇ -1,3-glucan-iBu, ⁇ -1,3-glucan Pellets of -iVa and ⁇ -1,3-glucan-Pi powder were used. In addition, polypropylene (PP) and polylactic acid (PLLA), which are known to have good thermoformability, were used as comparison targets. The sample mass was 1.5 g. The measurement start temperature was set near the glass transition point of each sample. After heating at the starting temperature for 300 seconds, the temperature was raised at 5 ° C / min. The measurement was finished when all the samples flowed out. The test force was 10 kgf, the die hole diameter was 1 mm, and the die length was 1 mm.
  • Figure 4 shows the temperature dependence of the viscosities obtained by the capillary rheometer for various esterified ⁇ -1,3-glucan derivatives.
  • the viscosity of ⁇ -1,3-glucan-Pi decreased sharply between the glass transition point and the melting point.
  • the viscosity at this time was lowered to the same level as the viscosity of polypropylene or polylactic acid after the melting point, and it was found that thermoforming between the glass transition point and the melting point was possible.
  • the viscosities of ⁇ -1,3-glucan-Pr and ⁇ -1,3-glucan-iBu decreased sharply after the melting point.
  • the viscosity after the melting point is lowered to the same level as the viscosity after the melting point of polypropylene, polylactic acid, etc., and there is a possibility that thermoforming can be performed.
  • an increase in viscosity was observed between the glass transition point and the melting point in all samples except ⁇ -1,3-glucan-Pi. This is considered to be due to the binding of molecular chains due to crystallization.
  • polysaccharide ester derivatives are concerned about decomposition of ester groups and coloration associated therewith at temperatures exceeding 300 ° C. Addition of antioxidants to prevent these problems and plasticizers to increase fluidity. Attempts have been made to add or introduce long-chain ester groups that themselves serve as plasticizers.
  • the introduction of petroleum-derived additives reduces the degree of biomass, and the introduction of long-chain esters reduces thermal properties. Therefore, like ⁇ -1,3-glucan-Pi introduced with a tribranched ester which is an esterified ⁇ -1,3-glucan derivative of the present invention, thermoforming is performed at a relatively low temperature between the glass transition point and the melting point. If possible, it is very useful because good moldability can be obtained without lowering the degree of biomass and thermal properties, and the above measurement results demonstrate such usefulness.
  • ⁇ -1,3-Glucan-Acetate Ac
  • ⁇ -1,3-Glucan-Hexanoate Hex
  • ⁇ -1,3- synthesized in Example 1 as esterified ⁇ -1,3-glucan derivatives Glucan-Ibutyrate (iBu) and ⁇ -1,3-Glucan-Pivalate (Pi) were used.
  • Test method Automatic equilibrium bridge method (LCR meter method)
  • Test equipment LCR meter HP4284A (manufactured by Agilent Technologies) TO-19 constant temperature bath (manufactured by Ando Electric) SE-70 type solid electrode (manufactured by Ando Electric)
  • Specimen size 5 cm Square electrode: Main electrode diameter 10.5 mm
  • Thickness measurement Micrometer Procedure: A sample was placed on a copper plate, and the main electrode was pressed with a cylindrical metal Al. The temperature was measured by a temperature sensor attached on a copper plate.
  • the relative permittivity of the two types of ⁇ -1,3-Glucan branched ester derivatives is smaller than that of the linear ester derivative ⁇ -1,3-Glucan-Ac. It was similar to ⁇ -1,3-Glucan-Hex.
  • a graph of the temperature dependence of the dielectric constant is shown in FIG.
  • the glass transition point of an aromatic polymer such as Toron (registered trademark), which is generally used as a heat-resistant insulator is 200 ° C. or higher, which is equivalent to or equal to that of an ⁇ -1,3-Glucan branched ester derivative.
  • Toron registered trademark
  • their relative permittivity is about 4, and their insulating properties are inferior to those of ⁇ -1,3-Glucan branched ester derivatives.
  • the dielectric constant of polyethylene and polypropylene is lower than that of ⁇ -1,3-Glucan branched ester derivatives, but their glass transition points are significantly lower than those of ⁇ -1,3-Glucan branched ester derivatives.
  • the ⁇ -1,3-Glucan branched ester derivative was found to be promising as a novel heat-resistant insulator.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biochemistry (AREA)
  • Molecular Biology (AREA)
  • General Health & Medical Sciences (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)

Abstract

[Problem] To provide a novel α-1,3-glucan derivative into which an ester chain having a branch has been introduced. [Solution] An esterified α-1,3-glucan derivative represented by formula (1), having a structure in which glucose units are polymerized linearly with α-1,3-glycosidic linkages. (In the formula, the Rs may be the same or different and are acyl groups with 4-20 carbons having a 2-branched or 3-branched alkyl chain, and n is 100-20,000.)

Description

分岐鎖エステル化α－１，３－グルカン誘導体Branched chain esterified α-1,3-glucan derivative
　本発明は、２分岐又は３分岐のエステル鎖を導入したα－１，３－グルカン誘導体に関する。 The present invention relates to an α-1,3-glucan derivative introduced with a bi- or tri-branched ester chain.
　近年、二酸化炭素排出や環境問題等により、石油由来に替わり、再生産可能な植物バイオマスを原料とした高強度で耐熱性に優れたバイオベースプラスチックの開発が求められています。とりわけ、天然高分子の一つである多糖類を原料とするバイオベースプラスチックが注目されおり、これまで利用されてきた天然多糖類としてはセルロース（β－１，４－グルカン）、デンプン（α－１，４－グルカン）、キシラン（β－１，４－キシラン）等の植物由来のものや、カードラン（β－１，３－グルカン）やデキストラン（α－１，６－グルカン）等の微生物が生産するものがある。かかる天然多糖類由来の高分子は、由来の糖ユニットの種類、結合部位、アノマーの違いにより、高分子としての物性が大きく異なる。 In recent years, due to carbon dioxide emissions and environmental problems, there has been a demand for the development of high-strength, heat-resistant bio-based plastics made from reproducible plant biomass instead of petroleum-derived ones. In particular, bio-based plastics made from polysaccharides, which are one of the natural polymers, are attracting attention, and the natural polysaccharides that have been used so far are cellulose (β-1,4-glucan) and starch (α-). Plant-derived substances such as 1,4-glucan) and xylan (β-1,4-xylan), and microorganisms such as curdlan (β-1,3-glucan) and dextran (α-1,6-glucan). Has something to produce. Such a polymer derived from a natural polysaccharide has greatly different physical properties as a polymer depending on the type of the derived sugar unit, the binding site, and the anomer.
　このような多糖類の一種として、グルコースがα－１，３－グリコシド結合により重合結合した高分子であるα－１，３－グルカンが知られている。α－１，３－グルカンは、菌類や酵母の細胞壁に構造多糖として存在する他、口内連鎖球菌であるストレプトコッカス類によって産生される。 As one of such polysaccharides, α-1,3-glucan, which is a polymer in which glucose is polymerized and bonded by an α-1,3-glycosidic bond, is known. α-1,3-glucan exists as a structural polysaccharide on the cell wall of fungi and yeast, and is also produced by streptococci, which are oral streptococci.
　本発明者らは、虫歯菌由来のα－１，３－グルカン合成酵素であるＧｔｆＪ遺伝子をクローニングし、大腸菌発現系を利用して得られた組み換えＧｔｆＪ酵素を用いることで、スクロースから直鎖状のα－１，３－グルカンを合成できることを報告している（特許文献１）。　さらに、本発明者らは、α－１，３－グルカンにおけるＯＨ基を直鎖状飽和カルボン酸で置換することによって、有機溶媒への溶解性および熱可塑性を付与することができることも見出している（非特許文献１）。しかしながら、α－１，３－グルカンにおけるＯＨ基に分岐鎖エステルを導入した誘導体の合成例は報告されておらず、その熱特性や機械特性の解明が求められている。 The present inventors cloned the GtfJ gene, which is an α-1,3-glucan synthase derived from sucrose, and used the recombinant GtfJ enzyme obtained by utilizing the Escherichia coli expression system to linearize from sucrose. It has been reported that α-1,3-glucan can be synthesized (Patent Document 1). Furthermore, the present inventors have also found that by substituting the OH group in α-1,3-glucan with a linear saturated carboxylic acid, solubility and thermoplasticity in an organic solvent can be imparted. (Non-Patent Document 1). However, no synthetic example of a derivative in which a branched chain ester is introduced into an OH group in α-1,3-glucan has been reported, and elucidation of its thermal properties and mechanical properties is required.
特開２０１８－１０２２４９号公報JP-A-2018-102249
　そこで、本発明は、分岐を有するエステル鎖を導入した新規α－１，３－グルカン誘導体を提供することを課題とするものである。 Therefore, it is an object of the present invention to provide a novel α-1,3-glucan derivative into which an ester chain having a branch is introduced.
　本発明者らは、上記課題を解決するべく鋭意検討を行った結果、２分岐又は３分岐のエステル鎖を導入したα－１，３－グルカン誘導体が、驚くべきことに、従来の直鎖状エステル鎖を導入した誘導体と異なる熱特性等の物性を有すること、さらに、かかる分岐鎖エステル化α－１，３－グルカン誘導体から成型したフィルムが、優れた耐熱性や熱成形性とともに、優れた絶縁性を有し、エンジニアリングプラスチックとして好適であることを見出した。これらの新たな知見に基づき、本発明を完成するに至ったものである。 As a result of diligent studies to solve the above problems, the present inventors have surprisingly found that the α-1,3-glucan derivative introduced with a bifurcated or trifurcated ester chain is a conventional linear chain. The film molded from the branched chain esterified α-1,3-glucan derivative has excellent physical properties such as thermal properties different from those of the derivative into which the ester chain has been introduced, and is excellent in heat resistance and thermoformability. It has been found that it has insulating properties and is suitable as an engineering plastic. Based on these new findings, the present invention has been completed.
　すなわち、本発明は、一態様において、
＜１＞α－１，３－グリコシド結合によりグルコース単位が直鎖状に重合した構造を有する、式（１）で表されるエステル化α－１，３－グルカン誘導体：
Figure JPOXMLDOC01-appb-C000002
 （式中、各Ｒは、それぞれ同一でも異なっていてもよい、２分岐又は３分岐のアルキル鎖を有する炭素数４～２０のアシル基であり、ｎは、１００～２０，０００である。）；
＜２＞前記Ｒが、イソブチリル基、イソバレリル基、イソヘキサノイル基、イソヘプタノイル基、及びピバロイル基よりなる群から選択される、上記＜１＞に記載のエステル化α－１，３－グルカン誘導体；
＜３＞融点が２５０～３４０℃であり、かつ、ガラス転移温度が１００～２１０℃の範囲である、上記＜１＞又は＜２＞に記載のエステル化α－１，３－グルカン誘導体；
＜４＞ガラス転移温度が１５０℃以上であって、かつ融点とガラス転移温度との差が１１０℃以内である、上記＜３＞に記載のエステル化α－１，３－グルカン誘導体；
＜５＞２００～２８０℃の領域において粘度が５０ｋＰａ・ｓ以下となる、上記＜１＞～＜４＞のいずれかに記載のエステル化α－１，３－グルカン誘導体；
＜６＞ガラス転移温度と融点との間の領域において粘度が５０ｋＰａ・ｓ以下となる、上記＜１＞～＜５＞のいずれかに記載のエステル化α－１，３－グルカン誘導体；
＜７＞重量平均分子量（Ｍｗ）が、１．８×１０５以上である、上記＜１＞～＜６＞のいずれかに記載のエステル化α－１，３－グルカン誘導体；及び
＜８＞多分散度（Ｍｗ／Ｍｎ）が、２．０～３．０の範囲である、上記＜１＞～＜７＞のいずれかに記載のエステル化α－１，３－グルカン誘導体
を提供するものである。 That is, the present invention, in one aspect,
<1> An esterified α-1,3-glucan derivative represented by the formula (1), which has a structure in which glucose units are linearly polymerized by an α-1,3-glycosidic bond:
Figure JPOXMLDOC01-appb-C000002
 (In the formula, each R is an acyl group having 4 to 20 carbon atoms having a bifurcated or trifurcated alkyl chain, which may be the same or different, and n is 100 to 20,000.) ;
<2> The esterified α-1,3-glucan derivative according to <1> above, wherein the R is selected from the group consisting of an isobutyryl group, an isovaleryl group, an isohexanoyl group, an isoheptanoyle group, and a pivaloyl group;
<3> The esterified α-1,3-glucan derivative according to <1> or <2> above, wherein the melting point is 250 to 340 ° C. and the glass transition temperature is in the range of 100 to 210 ° C.;
<4> The esterified α-1,3-glucan derivative according to <3> above, wherein the glass transition temperature is 150 ° C. or higher and the difference between the melting point and the glass transition temperature is 110 ° C. or lower;
<5> The esterified α-1,3-glucan derivative according to any one of <1> to <4> above, wherein the viscosity is 50 kPa · s or less in the region of 200 to 280 ° C.
<6> The esterified α-1,3-glucan derivative according to any one of <1> to <5> above, wherein the viscosity is 50 kPa · s or less in the region between the glass transition temperature and the melting point;
<7> The weight average molecular weight (Mw) is 1.8 × 10 5 or more, the <1> esterified alpha-1,3-glucan derivative according to any one of 1 to <6>; and <8> The esterified α-1,3-glucan derivative according to any one of <1> to <7>, wherein the polydispersity (Mw / Mn) is in the range of 2.0 to 3.0. Is.
　別の態様において、本発明は、
＜９＞上記＜１＞～＜８＞のいずれかに記載のエステル化α－１，３－グルカン誘導体を含む構造体；
＜１０＞前記構造体が、射出成形、圧縮成形、ブロー成形、インフレーション成形エンゲル成形、押出成形、押出ラミネート成形、回転成形、カレンダー成形、真空成型、スタンピング成形、スプレーアップ成形、積層成形、注形法、注入成形、手積み成形、低圧成形、トランスファー成形、発泡成形、ブロー成形、又はＴダイ法により成形されてなる、上記＜９＞に記載の構造体；
＜１１＞前記構造体がフィルムである、上記＜９＞又は＜１０＞に記載の構造体；及び
＜１２＞３００ｎｍにおいて４０％以上の透過率を有する、上記＜１１＞に記載の構造体
を提供するものである。 In another aspect, the invention
<9> A structure containing the esterified α-1,3-glucan derivative according to any one of <1> to <8>above;
<10> The structure is injection molding, compression molding, blow molding, inflation molding engel molding, extrusion molding, extrusion laminating molding, rotary molding, calendar molding, vacuum molding, stamping molding, spray-up molding, laminate molding, casting. The structure according to <9> above, which is formed by a method, injection molding, manual stack molding, low pressure molding, transfer molding, foam molding, blow molding, or T-die method;
<11> The structure according to <9> or <10>, wherein the structure is a film; and the structure according to <11>, which has a transmittance of 40% or more at <12> 300 nm. It is to provide.
　本発明の分岐エステル鎖を導入した新規α－１，３－グルカン誘導体を用いることで、優れた耐熱性や熱成形性を有し、さらに優れた機械的性質を併せ持つ、バイオベースプラスチック製フィルム等の材料を提供することができる。より詳細には、本発明の分岐エステル鎖を導入したα－１，３－グルカン誘導体では、同じ炭素数の直鎖エステルを導入した場合と比べて、高いガラス転移温度が得られ、耐熱性の向上が得られる。加えて、比較的低温で熱流動性を示すため、熱特性の向上に加え、優れた熱成形性を有するという効果を提供することができる。 By using the novel α-1,3-glucan derivative introduced with the branched ester chain of the present invention, a bio-based plastic film or the like having excellent heat resistance and thermoforming properties and also having excellent mechanical properties. Materials can be provided. More specifically, in the α-1,3-glucan derivative introduced with the branched ester chain of the present invention, a higher glass transition temperature can be obtained and heat resistance is obtained as compared with the case where a linear ester having the same carbon number is introduced. You will get an improvement. In addition, since it exhibits thermal fluidity at a relatively low temperature, it can provide the effect of having excellent thermoformability in addition to improving thermal properties.
　さらに、従来の直鎖エステルをα－１，３－グルカンに導入する場合には、エステル鎖における炭素数の増加に伴い融点が低下する傾向が見られるのに対し、本発明の分岐エステル鎖を導入したα－１，３－グルカン誘導体では、分岐エステル鎖における炭素数を増加させることにより融点が高くなるという性質が得られることが分かった。これにより、分岐エステル鎖における炭素数やアルキル鎖長を変化させることで、熱的特性や機械的特性などをその用途に応じて制御可能であるという効果を奏する。特に、本発明のエステル化α－１，３－グルカン誘導体は、高い耐熱性と優れた絶縁性を両立でき、新規な耐熱性絶縁体として有用である。 Furthermore, when a conventional linear ester is introduced into α-1,3-glucan, the melting point tends to decrease as the number of carbon atoms in the ester chain increases, whereas the branched ester chain of the present invention is used. It was found that the introduced α-1,3-glucan derivative has the property of increasing the melting point by increasing the number of carbon atoms in the branched ester chain. As a result, by changing the number of carbon atoms and the length of the alkyl chain in the branched ester chain, it is possible to control the thermal properties and mechanical properties according to the application. In particular, the esterified α-1,3-glucan derivative of the present invention can achieve both high heat resistance and excellent insulating properties, and is useful as a novel heat-resistant insulator.
図１は、エステル化α－１，３－グルカン誘導体から調製した各種キャストフィルムの写真である。FIG. 1 is a photograph of various cast films prepared from esterified α-1,3-glucan derivatives. 図２は、エステル化α－１，３－グルカン誘導体から調製した各種キャストフィルムについて得られたUV-Visスペクトル（透過率）を示すグラフである。FIG. 2 is a graph showing UV-Vis spectra (transmittance) obtained for various cast films prepared from esterified α-1,3-glucan derivatives. 図３は、各種エステル化α－１，３－グルカン誘導体の融点（Ｔｍ）及びガラス転移温度（Ｔｇ）を、式（１）のアシル基Ｒにおける炭素数についてプロットしたグラフである。FIG. 3 is a graph in which the melting points (Tm) and glass transition temperature (Tg) of various esterified α-1,3-glucan derivatives are plotted for the number of carbon atoms in the acyl group R of the formula (1). 図４は、各種エステル化α－１，３－グルカン誘導体について、キャピラリーレオメーターにより得られた粘度の温度依存性を示すグラフである。FIG. 4 is a graph showing the temperature dependence of the viscosity obtained by the capillary rheometer for various esterified α-1,3-glucan derivatives. 図５は、各種エステル化α－１，３－グルカン誘導体について得られた誘電率の温度依存性を示すグラフである。FIG. 5 is a graph showing the temperature dependence of the dielectric constants obtained for various esterified α-1,3-glucan derivatives.
　以下、本発明の実施形態について説明する。本発明の範囲はこれらの説明に拘束されることはなく、以下の例示以外についても、本発明の趣旨を損なわない範囲で適宜変更し実施することができる。 Hereinafter, embodiments of the present invention will be described. The scope of the present invention is not limited to these explanations, and other than the following examples, the scope of the present invention can be appropriately modified and implemented without impairing the gist of the present invention.
１．分岐エステル化α－１，３－グルカン誘導体
　本発明に係る分岐エステル化α－１，３－グルカン誘導体は、α－１，３－グリコシド結合によりグルコース単位が直鎖状に重合した構造を有し、以下の式（１）で表されるように分子内に分岐鎖エステルを有することを特徴するものである。
Figure JPOXMLDOC01-appb-C000003
 1. 1. Branched esterified α-1,3-glucan derivative The branched esterified α-1,3-glucan derivative according to the present invention has a structure in which glucose units are linearly polymerized by α-1,3-glycosidic bonds. , It is characterized by having a branched chain ester in the molecule as represented by the following formula (1).
Figure JPOXMLDOC01-appb-C000003
　すなわち、式（１）で表されるα－１，３－グルカン誘導体は、重合体を構成するグルコース単位における３つの水酸基（ＯＨ基）が、２分岐又は３分岐のアルキル鎖を有するアシル基によりエステル化されＯＲ基となった構造を有する。ＯＨ基を有するα－１，３－グルカン（未エステル化α－１，３－グルカン）自体は熱可塑性を有しないが、かかるエステル化を行うことにより、直鎖状のα－１，３－グルカンの構造を残したままで、熱可塑性を発現させることができる。そのため、当該エステル誘導体を用いることで、熱により形を自在に変えられる熱可塑性のエンジニアリングプラスチック材料として用いることが可能となる。 That is, the α-1,3-glucan derivative represented by the formula (1) is composed of an acyl group in which three hydroxyl groups (OH groups) in the glucose unit constituting the polymer have a bifurcated or trifurcated alkyl chain. It has a structure that has been esterified to form an OR group. Α-1,3-Glucan having an OH group (unesterified α-1,3-glucan) itself does not have thermoplasticity, but by performing such esterification, linear α-1,3- Thermoplasticity can be developed while retaining the structure of glucan. Therefore, by using the ester derivative, it can be used as a thermoplastic engineering plastic material whose shape can be freely changed by heat.
　式中、各Ｒは、それぞれ同一でも異なっていてもよい、２分岐又は３分岐のアルキル鎖を有する炭素数４～２０のアシル基であり、好ましくは、２分岐又は３分岐のアルキル鎖を有する炭素数４～１２のアシル基である。かかる分岐数や炭素数を変化させることにより、α－１，３－グルカン誘導体の融点やガラス転移温度等の熱特性を制御することができる。 In the formula, each R is an acyl group having 4 to 20 carbon atoms having a bifurcated or trifurcated alkyl chain, which may be the same or different, and preferably has a bifurcated or trifurcated alkyl chain. It is an acyl group having 4 to 12 carbon atoms. By changing the number of branches and the number of carbon atoms, it is possible to control thermal characteristics such as the melting point and glass transition temperature of the α-1,3-glucan derivative.
　２分岐のアルキル鎖を有するアシル基の好ましい例としては、イソブチリル基、イソバレリル基、イソヘキサノイル基、イソヘプタノイル基、イソオクタノイル基、イソデカノイル基、イソステアロイル基を挙げることができるが、これらに限定されるものではない。また、３分岐のアルキル鎖を有するアシル基の好ましい例としては、ピバロイル基（ｔｅｒｔ－ブチリル基）、アセチルｔｅｒｔ－ブチリル基、プロピルｔｅｒｔ－ブチリル基、ブチリルｔｅｒｔ－ブチリル基を挙げることができる。 Preferred examples of the acyl group having a bifurcated alkyl chain include, but are limited to, an isobutyryl group, an isovaleryl group, an isohexanoyl group, an isoheptanoyyl group, an isooctanoyl group, an isodecanoyl group, and an isostearoyl group. It's not a thing. In addition, preferable examples of the acyl group having a tri-branched alkyl chain include a pivaloyl group (tert-butylyl group), an acetyl tert-butylyl group, a propyl tert-butylyl group, and a butyryl tert-butylyl group.
　Ｒにおけるアシル基による置換度（ＤＳ）は、２．０～３．０の範囲であり、好ましくは、２．５～３．０の範囲である。ここで、「置換度」とは、１グルコース単位当たりのエステルに置換された水酸基の平均数を意味する。すなわち、置換度が３であれば、式（１）における３つのＲがいずれもアシル基であり、各グルコース単位における３つのＯＨ基がすべてエステル化されている状態を示す。また、置換度が１であれば、式（１）における３つのＯＲ基のうち平均して１つがエステル化され、残りの２つのＯＲは水酸基のまま（すなわち、Ｒが水素原子）であることを示す。 The degree of substitution (DS) by the acyl group in R is in the range of 2.0 to 3.0, preferably in the range of 2.5 to 3.0. Here, the "degree of substitution" means the average number of hydroxyl groups substituted with the ester per glucose unit. That is, when the degree of substitution is 3, it means that all three Rs in the formula (1) are acyl groups, and all three OH groups in each glucose unit are esterified. If the degree of substitution is 1, one of the three OR groups in the formula (1) is esterified on average, and the remaining two ORs remain hydroxyl groups (that is, R is a hydrogen atom). Is shown.
　なお、α－１，３－グルカンの各グルコース単位内に存在する３つのＯＨ基（末端のグルコース単位では４つのＯＨ基）を置換して得られるエステル基は、それぞれ同一でも異なっていてもよい。すなわち、各グルコース単位内のエステル基において、各Ｒは同一または異なるアシル基であることができる。例えば、Ｒがランダムに異なるエステル基とすることができ、或いは、エステル化の手法を制御することによって異なる複数のエステル基を２：１の比率で得ることもできる。 The ester groups obtained by substituting the three OH groups (four OH groups in the terminal glucose unit) existing in each glucose unit of α-1,3-glucan may be the same or different. .. That is, in the ester group within each glucose unit, each R can be the same or different acyl group. For example, R can be randomly different ester groups, or a plurality of different ester groups can be obtained in a ratio of 2: 1 by controlling the esterification method.
　上記式（１）におけるｎは、１００～２０，０００であり、好ましくは、１００～１０，０００である。当該ｎの値により、エステル化α－１，３－グルカン誘導体の分子量等が変化することになるが、当該α－１，３－グルカン誘導体の重量平均分子量（Ｍｗ）は、好ましくは、１．８×１０５以上である。かかる分子量の制御は、主として、α－１，３－グルカンを合成する際における合成酵素の種類、反応温度、反応時間、界面活性剤の使用等によって行うことができる。 N in the above formula (1) is 100 to 20,000, preferably 100 to 10,000. The molecular weight of the esterified α-1,3-glucan derivative changes depending on the value of n, and the weight average molecular weight (Mw) of the α-1,3-glucan derivative is preferably 1. is 8 × 10 5 or more. Such control of the molecular weight can be performed mainly by the type of synthase, reaction temperature, reaction time, use of a surfactant and the like when synthesizing α-1,3-glucan.
　また、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）との比Ｍｗ／Ｍｎで表される多分散度（ＰＤＩ；又は分子量分布ともいう）が、好ましくは２．０～３．０の範囲である。 Further, the degree of polydispersity (also referred to as PDI; or molecular weight distribution) represented by the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is preferably in the range of 2.0 to 3.0. Is.
　重量平均分子量（Ｍｗ）及び数平均分子量（Ｍｎ）の測定には、当該技術分野における公知の手法を用いることができ、例えば、高圧液体クロマトグラフィー（ＨＰＬＣ）、サイズ排除クロマトグラフィー（ＳＥＣ）、またはゲル透過クロマトグラフィー（ＧＰＣ）などの手段を用いることができる。 Known techniques in the art can be used to measure weight average molecular weight (Mw) and number average molecular weight (Mn), such as high performance liquid chromatography (HPLC), size exclusion chromatography (SEC), or Means such as gel permeation chromatography (GPC) can be used.
　本発明のエステル化α－１，３－グルカン誘導体は、上述のように、グルコース単位がα－１，３－グリコシド結合によって直鎖状に重合した構造を有することを特徴とする。好ましくは、α－１，３－グルカン誘導体は、完全直鎖状の構造を有する。ここで、「完全直鎖状」とは、α－１，３－グルカンを構成するグルコース単位がα－１，３－グリコシド結合以外の分岐（グルコース及び他の糖による分岐）を有しないことを意味する。 As described above, the esterified α-1,3-glucan derivative of the present invention is characterized by having a structure in which glucose units are linearly polymerized by α-1,3-glycosidic bonds. Preferably, the α-1,3-glucan derivative has a completely linear structure. Here, "completely linear" means that the glucose unit constituting α-1,3-glucan does not have a branch other than the α-1,3-glycosidic bond (branch by glucose and other sugars). means.
　本発明のエステル化α－１，３－グルカン誘導体は、好ましくは、融点が２５０～３４０℃であることができ、当該融点は、広く用いられている石油由来のプラスチックの代表であるポリエチレン（融点＝１２０℃）、ポリプロピレン（融点＝１７５℃）、ナイロン-６（融点＝２２５℃）よりも高く、本発明のエステル化α－１，３－グルカンエステル誘導体はこれらよりも耐熱性に優れている。本発明の分岐エステル化α－１，３－グルカン誘導体では、上記式（１）中のＲの炭素数を多くすることで、よる高い融点が得られる傾向にある。これは、直鎖エステルを導入したα－１，３－グルカン誘導体では、アルキル鎖長を長くすると融点が低下する傾向を示すことと対照的なものであり、本発明で初めて見出された知見である。 The esterified α-1,3-glucan derivative of the present invention can preferably have a melting point of 250 to 340 ° C., which is a polyethylene (melting point) which is a representative of widely used petroleum-derived plastics. = 120 ° C.), polypropylene (melting point = 175 ° C.), nylon-6 (melting point = 225 ° C.), and the esterified α-1,3-glucan ester derivative of the present invention has better heat resistance than these. .. In the branched esterified α-1,3-glucan derivative of the present invention, a higher melting point tends to be obtained by increasing the number of carbon atoms of R in the above formula (1). This is in contrast to the fact that α-1,3-glucan derivatives introduced with a linear ester tend to have a lower melting point as the alkyl chain length is lengthened, and this is the first finding found in the present invention. Is.
　本発明のエステル化α－１，３－グルカン誘導体は、好ましくは、ガラス転移温度が１００～２１０℃の範囲であり、より好ましくは１５０℃以上である。これにより、優れた耐熱性と熱成形性を有することができる。好ましい態様では、本発明のエステル化α－１，３－グルカン誘導体は、ガラス転移温度が１５０℃以上であって、かつ融点とガラス転移温度との差が１１０℃以内であることができる。 The esterified α-1,3-glucan derivative of the present invention preferably has a glass transition temperature in the range of 100 to 210 ° C, more preferably 150 ° C or higher. Thereby, it is possible to have excellent heat resistance and thermoformability. In a preferred embodiment, the esterified α-1,3-glucan derivative of the present invention can have a glass transition temperature of 150 ° C. or higher and a difference between the melting point and the glass transition temperature of 110 ° C. or lower.
　また、本発明のエステル化α－１，３－グルカン誘導体は、優れた熱成形性の観点で、α－１，３－グルカン重合体の分解が生じる温度（一般に、３５０℃）以下で粘度が低下し流動性を示すことが好ましい。例えば、一の側面において、本発明のエステル化α－１，３－グルカン誘導体は、２００～２８０℃の領域の任意の点において粘度が５０ｋＰａ・ｓ以下となる。或いは、別の側面において、本発明のエステル化α－１，３－グルカン誘導体は、ガラス転移温度と融点との間の領域の任意の点において粘度が５０ｋＰａ・ｓ以下となる。 Further, the esterified α-1,3-glucan derivative of the present invention has a viscosity at a temperature (generally 350 ° C.) or lower at which decomposition of the α-1,3-glucan polymer occurs from the viewpoint of excellent thermoformability. It is preferable that it decreases and shows fluidity. For example, in one aspect, the esterified α-1,3-glucan derivative of the present invention has a viscosity of 50 kPa · s or less at any point in the region of 200 to 280 ° C. Alternatively, in another aspect, the esterified α-1,3-glucan derivative of the present invention has a viscosity of 50 kPa · s or less at any point in the region between the glass transition temperature and the melting point.
　さらに、本発明のエステル化α－１，３－グルカン誘導体は、上述の優れた耐熱性に加えて、高い絶縁性を併せて持つことができる。すなわち、本発明のエステル化α－１，３－グルカン誘導体は、５．０以下の比誘電率を有し、好ましくは、２．０～４．５の範囲、より好ましくは２．５～３．８範囲の比誘電率を有する。必ずしもこれに限定されるものではないが、特に好ましい態様では、本発明のエステル化α－１，３－グルカン誘導体は、ガラス転移温度が１００～２１０℃の範囲であり、かつ、比誘電率が２．５～３．８範囲の範囲であることができる。 Furthermore, the esterified α-1,3-glucan derivative of the present invention can have high insulating properties in addition to the above-mentioned excellent heat resistance. That is, the esterified α-1,3-glucan derivative of the present invention has a relative permittivity of 5.0 or less, preferably in the range of 2.0 to 4.5, and more preferably 2.5 to 3. It has a relative permittivity in the range of 0.8. Although not necessarily limited to this, in a particularly preferable embodiment, the esterified α-1,3-glucan derivative of the present invention has a glass transition temperature in the range of 100 to 210 ° C. and a relative permittivity. It can be in the range of 2.5 to 3.8.
　本発明のエステル化α－１，３－グルカン誘導体は、当該技術分野において公知のエステル化手法を用いて、ＯＨ基を有するα－１，３－グルカン（未エステル化α－１，３－グルカン）をエステル化することで合成することができる。例えば、塩基の存在下で所望の分岐アルキル鎖を有するカルボン酸無水物と反応させることにより、α－１，３－グルカンのＯＨ基をエステル基に変換することができる。または、酸触媒の存在下で、所望の分岐アルキル鎖を有する有機酸及び酸無水物と反応させることにより、α－１，３－グルカンのＯＨ基をエステル基に変換することもできる。 The esterified α-1,3-glucan derivative of the present invention is an α-1,3-glucan having an OH group (unesterified α-1,3-glucan) using an esterification method known in the art. ) Can be synthesized by esterification. For example, the OH group of α-1,3-glucan can be converted to an ester group by reacting with a carboxylic acid anhydride having a desired branched alkyl chain in the presence of a base. Alternatively, the OH group of α-1,3-glucan can be converted to an ester group by reacting with an organic acid having a desired branched alkyl chain and an acid anhydride in the presence of an acid catalyst.
　また、原料となる未エステル化α－１，３－グルカンは、公知のα－１，３－グルカン合成酵素を用いてスクロースから合成することができる。α－１，３－グルカン合成酵素は、スクロースを分解しながらグルコースをα－１，３－グリコシド結合で重合させることができる酵素であり、一般に、グルカンスクラーゼまたはグルコシルトランスフェラーゼ（「Ｇｔｆ」又は「ＧｔｆＪ」）とも呼ばれる。例えば、そのようなα－１，３－グルカン合成酵素としては、特開２０１８－１０２２４９号公報に開示されている虫歯菌（Ｓｔｒｅｐｔｏｃｏｃｃｕｓ ｓａｌｉｖａｒｉｕｓ）由来の酵素を用いることができる。当該酵素は、虫歯菌のα－１，３－グルカン合成酵素遺伝子をクローニングし、大腸菌等のプラスミドベクターに組み込み、これを宿主として発現させることで得ることができる。 Further, the unesterified α-1,3-glucan as a raw material can be synthesized from sucrose using a known α-1,3-glucan synthase. The α-1,3-glucan synthase is an enzyme capable of polymerizing glucose with an α-1,3-glycosidic bond while degrading sucrose, and is generally a glucan sucrase or glucosyl transferase (“Gtf” or “GtfJ”). ") Also called. For example, as such an α-1,3-glucan synthase, an enzyme derived from Streptococcus salivarius disclosed in JP-A-2018-102249 can be used. The enzyme can be obtained by cloning the α-1,3-glucan synthase gene of caries bacterium, incorporating it into a plasmid vector such as Escherichia coli, and expressing it as a host.
２．構造体の成形
　本発明のエステル化α－１，３－グルカン誘導体は、高い耐熱性と優れた機械的性質を併せ持つため、これを用いてフィルム等の構造体を好適に作成することができる。 2. 2. Molding of Structure Since the esterified α-1,3-glucan derivative of the present invention has both high heat resistance and excellent mechanical properties, a structure such as a film can be suitably produced by using the esterified α-1,3-glucan derivative.
　本発明のエステル化α－１，３－グルカン誘導体を含む構造体は、当該技術分野において公知の手法を用いて成形することができ、例えば、射出成形、圧縮成形、ブロー成形、インフレーション成形エンゲル成形、押出成形、押出ラミネート成形、回転成形、カレンダー成形、真空成型、スタンピング成形、スプレーアップ成形、積層成形、注形法、注入成形、手積み成形、低圧成形、トランスファー成形、発泡成形、ブロー成形、又はＴダイ法等の手法により成形することができる。 The structure containing the esterified α-1,3-glucan derivative of the present invention can be molded by a method known in the art, for example, injection molding, compression molding, blow molding, inflation molding Engel molding. , Extrusion molding, extrusion laminating molding, rotary molding, calendar molding, vacuum molding, stamping molding, spray-up molding, laminate molding, casting method, injection molding, manual stack molding, low pressure molding, transfer molding, foam molding, blow molding, Alternatively, it can be molded by a method such as the T-die method.
　好ましくは、本発明の構造体は、フィルムである。エステル化α－１，３－グルカン誘導体からフィルムを作成する手法としては、当該技術分野において公知の手法を用いることができるが、例えば、当該エステル誘導体を適切な有機溶媒に溶解させた溶液を塗布し、溶媒を除去することにより、所望の厚さのフィルムを得ることができる。当該有機溶媒としては、例えば、塩化メチレン（ジクロロメタン）、メタノール、クロロホルム、テトラクロロエタン、ギ酸、酢酸、ブロモホルム、ピリジン、ジオキサン、エタノール、アセトン、アルコール類、及びトルエンなどの芳香族化合物、酢酸エチル及び酢酸プロピルなどのエステル、テトラヒドロフラン、メチルセロソルブ、及びエチレングリコールモノメチルエーテルなどのエーテル、又はこれらの組み合わせを用いることができる。また、スピンコートや噴霧等の方法を用いてフィルムを成形することもできる。かかるフィルムをホットメルト法により材料表面に適用して、材料同士を接着することもできる。 Preferably, the structure of the present invention is a film. As a method for producing a film from an esterified α-1,3-glucan derivative, a method known in the art can be used. For example, a solution in which the ester derivative is dissolved in an appropriate organic solvent is applied. By removing the solvent, a film having a desired thickness can be obtained. Examples of the organic solvent include methylene chloride (dimethane), methanol, chloroform, tetrachloroethane, formic acid, acetic acid, bromoform, pyridine, dioxane, ethanol, acetone, alcohols, and aromatic compounds such as toluene, ethyl acetate and acetic acid. Esters such as propyl, ethers such as tetrahydrofuran, methyl cellosolve, and ethylene glycol monomethyl ether, or combinations thereof can be used. The film can also be molded by using a method such as spin coating or spraying. The film can also be applied to the surface of the material by a hot melt method to bond the materials together.
　本発明のエステル化α－１，３－グルカン誘導体により形成した構造体は、優れた透明性を有する。例えば、０．０５～０．２ｍｍ程度の厚さのフィルムにおいて、６０％以上の最大透過率を有することができる。特に、本発明のフィルムは紫外領域においても透明性を有するという利点があり、好ましくは、３００ｎｍにおいて４０％以上の透過率を有する。 The structure formed by the esterified α-1,3-glucan derivative of the present invention has excellent transparency. For example, a film having a thickness of about 0.05 to 0.2 mm can have a maximum transmittance of 60% or more. In particular, the film of the present invention has an advantage of having transparency even in the ultraviolet region, and preferably has a transmittance of 40% or more at 300 nm.
　本発明のエステル化α－１，３－グルカン誘導体により形成した構造体は、
好ましくは１０ＭＰａ以上の引張強度を有することができる。また、５％以上の破断伸び、及び０．１０ＧＰａ以上のヤング率を有することができる。エステル部位のＲの炭素数を調整することで、機械的特性を制御することができる。これらの物性は、当該技術分野において公知の手法によって測定することができる。 The structure formed by the esterified α-1,3-glucan derivative of the present invention is
It can preferably have a tensile strength of 10 MPa or more. In addition, it can have a breaking elongation of 5% or more and a Young's modulus of 0.10 GPa or more. The mechanical properties can be controlled by adjusting the carbon number of R in the ester moiety. These physical properties can be measured by a method known in the art.
　また、本発明のエステル化α－１，３－グルカン誘導体は、上述のように高い耐熱性と優れた熱成形性を有するため、フィルム以外の種々のプラスチック材料に応用することもできる。さらに、本発明のエステル化α－１，３－グルカン誘導体は、高い絶縁性をも併せ持つことができるため、耐熱性絶縁体としても利用することができる。 Further, since the esterified α-1,3-glucan derivative of the present invention has high heat resistance and excellent thermoformability as described above, it can be applied to various plastic materials other than films. Furthermore, since the esterified α-1,3-glucan derivative of the present invention can also have high insulating properties, it can also be used as a heat-resistant insulator.
　以下、実施例により本発明をさらに詳細に説明するが、本発明はこれらによって限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
１．エステル化α－１，３－グルカン誘導体の合成 1. 1. Synthesis of esterified α-1,3-glucan derivatives
［試薬］
Figure JPOXMLDOC01-appb-T000004
 [reagent]
Figure JPOXMLDOC01-appb-T000004
　未エステル化α－１，３－グルカンは、特開２０１８－１０２２４９号公報の開示に従い、大腸菌で生産した組換えグルコシルトランスフェラーゼ（ＧｔｆＪ酵素）を、ｐＨを調整したスクロース溶液に添加することで合成した。得られたα－１，３－グルカンは、ろ過により回収・水洗し、凍結乾燥、さらに１０５℃に設定した真空乾燥機の中で３．５時間乾燥した。 The unesterified α-1,3-glucan was synthesized by adding a recombinant glucosyl transferase (GtfJ enzyme) produced in Escherichia coli to a pH-adjusted sucrose solution in accordance with the disclosure of JP-A-2018-102249. .. The obtained α-1,3-glucan was collected by filtration, washed with water, freeze-dried, and further dried in a vacuum dryer set at 105 ° C. for 3.5 hours.
　続いて、α－１，３－グルカンを各種カルボン酸によりエステル化した。90 mlの酢酸と120 mlのトリフルオロ酢酸無水物（TFAA）をナスフラスコに入れ、50°Cのオイルバス中で5分間撹拌し、混合した。得られた混合溶液に乾燥した3.0 gのα-1,3-glucanを加え、50°Cで1時間撹拌した。反応後の溶液は均一になり、この溶液を1 Lのメタノールに入れ、沈殿させ、ろ過によって回収した。回収した沈殿物を100 mlのクロロホルムに溶かし、メタノールに再沈殿し、ろ過によって回収した。水とメタノールで洗浄した後、2日間常温常圧で乾燥し、最後に3時間真空乾燥した。酢酸に替えて、プロピオン酸、酪酸、吉草酸、ヘキサン酸、イソ酪酸、イソ吉草酸、イソヘキサン酸、イソヘプタン酸、ピバル酸を用いて同様のエステル化反応を行った。 Subsequently, α-1,3-glucan was esterified with various carboxylic acids. 90 ml of acetic acid and 120 ml of trifluoroacetic anhydride (TFAA) were placed in an eggplant flask and stirred in an oil bath at 50 ° C for 5 minutes to mix. Dry 3.0 g of α-1,3-glucan was added to the obtained mixed solution, and the mixture was stirred at 50 ° C. for 1 hour. The solution after the reaction became uniform, and this solution was placed in 1 L of methanol, precipitated, and recovered by filtration. The recovered precipitate was dissolved in 100 ml of chloroform, reprecipitated in methanol, and recovered by filtration. After washing with water and methanol, it was dried at normal temperature and pressure for 2 days, and finally vacuum dried for 3 hours. A similar esterification reaction was carried out using propionic acid, butyric acid, valeric acid, hexanoic acid, isobutyric acid, isovaleric acid, isohexanoic acid, isoheptanic acid and pivalic acid instead of acetic acid.
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
　酢酸、プロピオン酸、酪酸、吉草酸、ヘキサン酸、イソ酪酸、イソ吉草酸、イソヘキサン酸、イソヘプタン酸、ピバル酸と反応し得られたエステル誘導体を、それぞれα-1,3-glucan-Ac、α-1,3-glucan-Pr、α-1,3-glucan-Bu、α-1,3-glucan-Va、α-1,3-glucan-Hex、α-1,3-glucan-iBu、α-1,3-glucan-iVa、α-1,3-glucan-iHex、α-1,3-glucan-iHep、α-1,3-glucan-Piと表記する。 The ester derivatives obtained by reacting with acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, isobutyric acid, isovaleric acid, isohexanoic acid, isoheptanic acid, and pivalic acid were used as α-1,3-glucan-Ac and α, respectively. -1,3-glucan-Pr, α-1,3-glucan-Bu, α-1,3-glucan-Va, α-1,3-glucan-Hex, α-1,3-glucan-iBu, α Notated as -1,3-glucan-iVa, α-1,3-glucan-iHex, α-1,3-glucan-iHep, α-1,3-glucan-Pi.
　合成したエステル化α－１，３－グルカン誘導体について、GPC測定により算出した分子量（Ｍｗ）、多分散度（Ｍｗ／Ｍｎ）、及び置換度（ＤＳ）を以下の表２に示す。
Figure JPOXMLDOC01-appb-T000006
 The molecular weight (Mw), polydispersity (Mw / Mn), and substitution degree (DS) calculated by GPC measurement for the synthesized esterified α-1,3-glucan derivative are shown in Table 2 below.
Figure JPOXMLDOC01-appb-T000006
２．エステル化α－１,３－グルカン誘導体から成形したフィルムの物性 2. 2. Physical properties of film molded from esterified α-1,3-glucan derivative
２－１．フィルムの成形
　ソルベントキャスト法により、実施例１で得られたエステル化α－１,３－グルカン誘導体からフィルムを作成した。0.2 gのエステル化α－１,３－グルカン誘導体を2 mlのジクロロメタンに溶解し、直径約5.4 cmのテフロンシャーレに流し込んだ。直鎖状エステル誘導体は常温で3日間、分岐状エステル誘導体は40°Cのホットプレート上で１時間静置し、溶媒を完全に揮発させた。図１に示すように、得られたフィルムは、可視光域全般において透明性が高いものが得られた。 2-1. Film Molding A film was prepared from the esterified α-1,3-glucan derivative obtained in Example 1 by a solvent casting method. 0.2 g of esterified α-1,3-glucan derivative was dissolved in 2 ml of dichloromethane and poured into a Teflon petri dish about 5.4 cm in diameter. The linear ester derivative was allowed to stand at room temperature for 3 days, and the branched ester derivative was allowed to stand on a hot plate at 40 ° C. for 1 hour to completely volatilize the solvent. As shown in FIG. 1, the obtained film was highly transparent in the entire visible light region.
２－２．フィルムの透過率測定
　紫外可視近赤外分光法（UV-Vis）によりフィルムの光透過率を測定した。測定にはU-2910（日立）を用いた。２－１で作製したキャストフィルムをサンプルとして使用した。測定波長範囲は190 nm-1100 nmとし、スキャン速度は400 nm/minとした。 2-2. Film transmittance measurement The light transmittance of the film was measured by ultraviolet-visible near-infrared spectroscopy (UV-Vis). U-2910 (Hitachi) was used for the measurement. The cast film prepared in 2-1 was used as a sample. The measurement wavelength range was 190 nm-1100 nm, and the scan speed was 400 nm / min.
　各種キャストフィルムについて得られたUV-Visスペクトルを図２に示す。また、表３にフィルム厚と可視光範囲（450-760 nm）における光最大透過率を示す。可視光領域においては、エステル化α－１,３－グルカン誘導体は比較的透明性が高く、ポリエチレンテレフタレートやポリエチレンと同等の透明性を示した。また、紫外領域において、ポリエチレンテレフタレートは芳香環をもつため著しく透過率が低下するが、エステル化α－１,３－グルカン誘導体は紫外領域においても高い透過率を有することが分かった。
Figure JPOXMLDOC01-appb-T000007
 The UV-Vis spectra obtained for various cast films are shown in FIG. Table 3 shows the film thickness and the maximum light transmittance in the visible light range (450-760 nm). In the visible light region, the esterified α-1,3-glucan derivative had relatively high transparency and showed the same transparency as polyethylene terephthalate and polyethylene. Further, in the ultraviolet region, polyethylene terephthalate has an aromatic ring, so that the transmittance is remarkably lowered, but it was found that the esterified α-1,3-glucan derivative also has a high transmittance in the ultraviolet region.
Figure JPOXMLDOC01-appb-T000007
２－３．熱重量分析（TGA）
　測定にはTGA-50(島津製作所)を用いた。サンプル重量は約2 mgとした。温度範囲30°C-500°C、昇温速度20 °C/min、窒素流量50 ml/sで測定した。比較例として、未エステル化のα－１,３－グルカンについても同様の測定を行った。エステル化α－１,３－グルカン誘導体について得られたＴＧＡサーモグラムから算出した試料重量減少率が５％および50%の時の温度（Td.5%、Td.50%）を以下の表４に示す。
Figure JPOXMLDOC01-appb-T000008
 2-3. Thermogravimetric analysis (TGA)
TGA-50 (Shimadzu Corporation) was used for the measurement. The sample weight was about 2 mg. The measurement was performed at a temperature range of 30 ° C-500 ° C, a heating rate of 20 ° C / min, and a nitrogen flow rate of 50 ml / s. As a comparative example, the same measurement was performed for unesterified α-1,3-glucan. Table 4 below shows the temperatures (Td.5%, Td.50%) when the sample weight loss rate calculated from the TGA thermograms obtained for the esterified α-1,3-glucan derivative was 5% and 50%. Shown in.
Figure JPOXMLDOC01-appb-T000008
　α-1,3-glucanに対し、α-1,3-glucan-Hexは約50°C、他のα－１,３－グルカンエステル誘導体は約90°C熱分解温度が向上した。この結果は、α－１,３－グルカンの水酸基をエステル基に置換することによって、レボグルコサンの生成が抑制され、熱分解温度が向上したことを示すものと考えられる。 Compared to α-1,3-glucan, α-1,3-glucan-Hex improved the thermal decomposition temperature by about 50 ° C, and other α-1,3-glucan ester derivatives improved by about 90 ° C. This result is considered to indicate that the production of levoglucosan was suppressed and the thermal decomposition temperature was improved by substituting the hydroxyl group of α-1,3-glucan with an ester group.
２－４．融点及びガラス転移点の測定
　各種エステル化α－１,３－グルカン誘導体について、示差走査熱量測定（DSC）及び動的粘弾性測定（DMA）を用いて、それぞれ融点（Ｔｍ）及びガラス転移点（Ｔｇ）の測定を行った。 2-4. Measurement of melting point and glass transition point For various esterified α-1,3-glucan derivatives, using differential scanning calorimetry (DSC) and dynamic viscoelasticity measurement (DMA), respectively, the melting point (Tm) and glass transition point (Tm) and glass transition point ( Tg) was measured.
　示差走査熱量測定では、DSC8500（Perkin Elmer）を用いた。サンプルはキャストフィルムを用い、重量は約3mgとした。それぞれのサンプルを10分または20分間の等温保持後、-30°Cから380°Cまでの昇温過程(1st run)において、融点を評価した。昇温速度は20 °C/minとした。保持温度はα-1,3-glucan-Acは260°C、α-1,3-glucan-Prは250°C、α-1,3-glucan-Buとα-1,3-glucan-Vaは210°C、α-1,3-glucan-Hexは200°C、α-1,3-glucan-iBuは240°C、α-1,3-glucan-iVaとα-1,3-glucan-iHex、α-1,3-glucan-iHepは280°Cとした。ただし、α-1,3-glucan-Piは熱処理なしで融点が観測できたため、熱処理を行っていない。測定は窒素雰囲気下で行い、対照物質には空のアルミパンを用いた。 DSC8500 (PerkinElmer) was used for differential scanning calorimetry. A cast film was used as the sample, and the weight was about 3 mg. After each sample was held at an isothermal temperature for 10 or 20 minutes, the melting point was evaluated in the heating process (1st run) from -30 ° C to 380 ° C. The heating rate was 20 ° C / min. Holding temperature is 260 ° C for α-1,3-glucan-Ac, 250 ° C for α-1,3-glucan-Pr, α-1,3-glucan-Bu and α-1,3-glucan-Va Is 210 ° C, α-1,3-glucan-Hex is 200 ° C, α-1,3-glucan-iBu is 240 ° C, α-1,3-glucan-iVa and α-1,3-glucan -iHex and α-1,3-glucan-iHep were set to 280 ° C. However, since the melting point of α-1,3-glucan-Pi could be observed without heat treatment, it was not heat-treated. The measurement was carried out in a nitrogen atmosphere, and an empty aluminum pan was used as a control substance.
　動的粘弾性測定では、D-VA 200S（アイティー計測制御）を用いた。厚さ0.6 mm-1.0 mmのキャストフィルムを長さ7 mm、幅5 mmに切断しサンプルとした。窒素雰囲気下で、条件は剪断モード、温度範囲は30°C-380°C、昇温速度は2 °C/min、測定周波数は10 Hzとした。 D-VA200S (IT measurement control) was used for dynamic viscoelasticity measurement. A cast film with a thickness of 0.6 mm-1.0 mm was cut into a sample with a length of 7 mm and a width of 5 mm. Under a nitrogen atmosphere, the conditions were shear mode, the temperature range was 30 ° C-380 ° C, the rate of temperature rise was 2 ° C / min, and the measurement frequency was 10 Hz.
　得られた融点（Ｔｍ）及びガラス転移点（Ｔｇ）を以下の表５に示す。
Figure JPOXMLDOC01-appb-T000009
 The obtained melting points (Tm) and glass transition points (Tg) are shown in Table 5 below.
Figure JPOXMLDOC01-appb-T000009
　また、これらＴｍ及びＴｇの値と、アシル基Ｒにおける炭素数との関係を図３に示す。 Further, the relationship between these Tm and Tg values and the number of carbon atoms in the acyl group R is shown in FIG.
　これらの結果から、本発明の分岐エステル化α－１，３－グルカン誘導体であるα-1,3-glucan-iBu及びα-1,3-glucan-Piでは、２００℃を超える高いガラス転移点を有すること、及び、融点とガラス転移点との差が１００℃以内となることが分かった。また、本発明の分岐エステル化α－１，３－グルカン誘導体では側鎖の炭素数が増大するにつれ、融点が上昇する傾向があることがわかった。また、ガラス転移点は、側鎖の炭素数が増大するにつれて低下するものの、ある程度のところで下げ止まることが分かった。側鎖長の増加による融点の上昇は多糖エステル誘導体としては特異的な挙動である。融点の上昇の原因として、より密に結晶が構築されていることが考えられる。しかしながら、側鎖が長くなるにつれ融点に由来する発熱エンタルピーΔＨの値が低下しており、結晶性は低下していると考えられる。ガラス転移点の低下は、非晶領域における分子間凝集力の低下に起因すると考えられる。 From these results, the branched esterified α-1,3-glucan derivatives of the present invention, α-1,3-glucan-iBu and α-1,3-glucan-Pi, have a high glass transition point exceeding 200 ° C. It was found that the temperature and the difference between the melting point and the glass transition point were within 100 ° C. It was also found that in the branched esterified α-1,3-glucan derivative of the present invention, the melting point tends to increase as the number of carbon atoms in the side chain increases. It was also found that the glass transition point decreases as the number of carbon atoms in the side chain increases, but stops decreasing at some point. The increase in melting point due to the increase in side chain length is a specific behavior for a polysaccharide ester derivative. It is considered that the crystals are more densely constructed as the cause of the increase in the melting point. However, it is considered that the value of the exothermic enthalpy ΔH derived from the melting point decreases as the side chain becomes longer, and the crystallinity decreases. The decrease in the glass transition point is considered to be due to the decrease in the intermolecular cohesive force in the amorphous region.
　一方、直鎖状エステルを導入したα－１,３－グルカン誘導体では、側鎖が長くなるにつれ、融点が低下するという対照的な傾向があることがわかった。また、ガラス転移点は、側鎖が長くなるにつれ、ほぼ直線的に低下する傾向であることが分かった。これは、長い側鎖を導入することによって、主鎖間距離が増大し、分子間凝集力が低下するためと考えられる。 On the other hand, it was found that the α-1,3-glucan derivative introduced with the linear ester tends to have a contrasting tendency that the melting point decreases as the side chain becomes longer. It was also found that the glass transition point tends to decrease almost linearly as the side chain becomes longer. It is considered that this is because the introduction of a long side chain increases the distance between the main chains and reduces the intermolecular cohesive force.
　また、本発明の分岐エステル化α－１，３－グルカン誘導体では、同炭素数の側鎖を持つ直鎖状エステル誘導体より、高い融点を示した。ガラス転移点についても、本発明の分岐エステル化α－１，３－グルカン誘導体は、同炭素数の側鎖を持つ直鎖状エステル誘導体より、高い値を示した。 In addition, the branched esterified α-1,3-glucan derivative of the present invention showed a higher melting point than the linear ester derivative having a side chain having the same carbon number. Regarding the glass transition point, the branched esterified α-1,3-glucan derivative of the present invention showed a higher value than the linear ester derivative having a side chain having the same carbon number.
　α-1,3-glucan-iBuはTmが257°C、Tgが206°C、α-1,3-glucan-PiはTmが307°C、Tgが202°Cであり、これらは汎用プラスチックであるポリプロピレン（Tm=188°C、Tg=-20°C）、ナイロン6（Tm=220°C、Tg=40°C）やポリエチレンテレフタレート（Tm=270°C、Tg=69°C）の熱特性を上回る。特にガラス転移点は、以前に報告された多糖エステル誘導体であるカードランピバレート（Tg＝173°C）やグルコマンナントリアセテート（Tg=174°C）、α-1,3-gluca-Ac、エンジニアリングプラスチックであるポリカーボネート（Tg=151°C）よりも高い。 α-1,3-glucan-iBu has Tm of 257 ° C and Tg of 206 ° C, and α-1,3-glucan-Pi has Tm of 307 ° C and Tg of 202 ° C. These are general-purpose plastics. Polypropylene (Tm = 188 ° C, Tg = -20 ° C), nylon 6 (Tm = 220 ° C, Tg = 40 ° C) and polyethylene terephthalate (Tm = 270 ° C, Tg = 69 ° C) Exceeds thermal properties. In particular, the glass transition points are previously reported polysaccharide ester derivatives such as curdlampivarate (Tg = 173 ° C), glucomannan triacetate (Tg = 174 ° C), α-1,3-gluca-Ac, and engineering plastics. It is higher than polycarbonate (Tg = 151 ° C).
２－５．フィルムの機械的特性
　２－１で作製した各種キャストフィルムの引張試験を行った。測定には卓上万能試験機Eztest（島津製作所）を用いた。フィルムを長さ25-30 mm、幅5 mmに切断し、サンプルとして使用した。測定は最低5回行い、それらの平均値を結果とした。 2-5. Tensile tests of various cast films prepared according to the mechanical properties 2-1 of the film were carried out. A desktop universal testing machine Eztest (Shimadzu Corporation) was used for the measurement. The film was cut to a length of 25-30 mm and a width of 5 mm and used as a sample. The measurement was performed at least 5 times, and the average value of them was used as the result.
　各種キャストフィルムについて得られた引張強度、破断伸び、及びヤング率の結果を以下の表６に示す。
Figure JPOXMLDOC01-appb-T000010
 The results of tensile strength, elongation at break, and Young's modulus obtained for various cast films are shown in Table 6 below.
Figure JPOXMLDOC01-appb-T000010
　本発明の分岐エステル化α－１，３－グルカン誘導体、及び直鎖状エステル誘導体はともに、側鎖の炭素数が増加するにつれヤング率、引張強度が低下し、破断伸びが上昇する傾向にあった。これは、側鎖が長くなるにつれ、主鎖の凝集が低下したためだと考えられる。また、炭素数の増加に伴い分岐状エステル誘導体の破断伸びが大きい。これはもともと直鎖より分岐のほうが側鎖同士は絡み合いやすいが、側鎖が長くなるにつれ、側鎖の相互作用の影響が大きくなり、側鎖の絡み合いの効果が発現したためだと考えられる。分子量の大きな分岐エステル化α－１，３－グルカン誘導体を用いることで機械特性の改善が期待できる。 In both the branched esterified α-1,3-glucan derivative and the linear ester derivative of the present invention, Young's modulus and tensile strength tend to decrease and elongation at break tends to increase as the number of carbon atoms in the side chain increases. It was. It is considered that this is because the aggregation of the main chain decreased as the side chain became longer. In addition, the elongation at break of the branched ester derivative increases as the number of carbon atoms increases. It is considered that this is because the side chains are originally more likely to be entangled with each other in the branch than in the straight chain, but as the side chains become longer, the influence of the side chain interaction becomes greater and the effect of the side chain entanglement appears. Improvement of mechanical properties can be expected by using a branched esterified α-1,3-glucan derivative having a large molecular weight.
３．エステル化α－１，３－グルカン誘導体の成形性の検討
　一般に、プラスチックの成形加工は、高温化等により材料に流動性を与えた後、固体化させることが必要であるため、本発明のエステル化α－１，３－グルカン誘導体の熱成形性の指標として、加熱による流動性の変化の評価を行った。 3. 3. Examination of Moldability of Esterified α-1,3-Glucan Derivatives Generally, in the molding process of plastics, it is necessary to give fluidity to the material by high temperature or the like and then solidify it. Therefore, the ester of the present invention As an index of thermoformability of the esterified α-1,3-glucan derivative, the change in fluidity due to heating was evaluated.
　キャピラリーレオメーターによる溶融粘度の測定を行った。測定にはCFT-500EX（島津製作所）を用いた。サンプルにはα-1,3-glucan-Ac、α-1,3-glucan-Pr、α-1,3-glucan-Bu、α-1,3-glucan-iBu、α-1,3-glucan-iVa、α-1,3-glucan-Piの粉体をペレット状にしたものを用いた。また、比較対象として良好な熱成型性をもつことが知られているポリプロピレン（PP）、ポリ乳酸（PLLA）を用いた。サンプル質量は1.5 gとした。測定開始温度はそれぞれのサンプルのガラス転移点付近とした。開始温度で300秒間加熱した後、5 °C/minで昇温した。サンプルが全て流出した時点で測定を終了した。試験力は10 kgf、ダイ穴径は1 mm、ダイ長さは1 mmとした。 The melt viscosity was measured with a capillary rheometer. CFT-500EX (Shimadzu Corporation) was used for the measurement. Samples include α-1,3-glucan-Ac, α-1,3-glucan-Pr, α-1,3-glucan-Bu, α-1,3-glucan-iBu, α-1,3-glucan Pellets of -iVa and α-1,3-glucan-Pi powder were used. In addition, polypropylene (PP) and polylactic acid (PLLA), which are known to have good thermoformability, were used as comparison targets. The sample mass was 1.5 g. The measurement start temperature was set near the glass transition point of each sample. After heating at the starting temperature for 300 seconds, the temperature was raised at 5 ° C / min. The measurement was finished when all the samples flowed out. The test force was 10 kgf, the die hole diameter was 1 mm, and the die length was 1 mm.
　各種エステル化α－１，３－グルカン誘導体について、キャピラリーレオメーターにより得られた粘度の温度依存性を図４に示す。 Figure 4 shows the temperature dependence of the viscosities obtained by the capillary rheometer for various esterified α-1,3-glucan derivatives.
　α-1,3-glucan-Piはガラス転移点と融点の間で急激に粘度が低下した。この時の粘度は融点後のポリプロピレンやポリ乳酸の粘度と同等まで低下しており、ガラス転移点と融点の間における熱成形が可能であることが分かった。また、α-1,3-glucan-Pr、α-1,3-glucan-iBuは融点後に急激に粘度が低下した。融点後の粘度はポリプロピレンやポリ乳酸等の融点後の粘度と同等まで低下しており、熱成形ができる可能性がある。また、α-1,3-glucan-Piを除く全てのサンプルにおいて、ガラス転移点と融点の間で粘度の上昇が観察された。これは結晶化による分子鎖の束縛に起因すると考えられる。 The viscosity of α-1,3-glucan-Pi decreased sharply between the glass transition point and the melting point. The viscosity at this time was lowered to the same level as the viscosity of polypropylene or polylactic acid after the melting point, and it was found that thermoforming between the glass transition point and the melting point was possible. The viscosities of α-1,3-glucan-Pr and α-1,3-glucan-iBu decreased sharply after the melting point. The viscosity after the melting point is lowered to the same level as the viscosity after the melting point of polypropylene, polylactic acid, etc., and there is a possibility that thermoforming can be performed. In addition, an increase in viscosity was observed between the glass transition point and the melting point in all samples except α-1,3-glucan-Pi. This is considered to be due to the binding of molecular chains due to crystallization.
　一般に、多糖エステル誘導体は300℃を超える温度ではエステル基の分解や、それに伴う着色が懸念されているおり、それらの問題を防ぐため酸化防止剤の添加や、流動性を高めるために可塑剤の添加や自身が可塑剤となる長鎖エステル基の導入が試みられている。しかし、石油由来の添加剤の導入はバイオマス度を低下させ、長鎖エステルの導入は熱特性を低下させる。したがって、本発明のエステル化α－１，３－グルカン誘導体である３分岐エステルを導入したα-1,3-glucan-Piのように、ガラス転移点と融点の間という比較的低温で熱成型が可能であれば、バイオマス度や熱特性を低下させずに良好な成形性が得られるため非常に有用であり、上記測定結果はかかる有用性を実証するものである。 In general, polysaccharide ester derivatives are concerned about decomposition of ester groups and coloration associated therewith at temperatures exceeding 300 ° C. Addition of antioxidants to prevent these problems and plasticizers to increase fluidity. Attempts have been made to add or introduce long-chain ester groups that themselves serve as plasticizers. However, the introduction of petroleum-derived additives reduces the degree of biomass, and the introduction of long-chain esters reduces thermal properties. Therefore, like α-1,3-glucan-Pi introduced with a tribranched ester which is an esterified α-1,3-glucan derivative of the present invention, thermoforming is performed at a relatively low temperature between the glass transition point and the melting point. If possible, it is very useful because good moldability can be obtained without lowering the degree of biomass and thermal properties, and the above measurement results demonstrate such usefulness.
４．エステル化α－１，３－グルカン誘導体の電気的特性の評価
　次いで、本発明のエステル化α－１，３－グルカン誘導体について、比誘電率及び誘電正接を測定し、電気的特性の評価を行った。 4. Evaluation of Electrical Properties of Esterified α-1,3-Glucan Derivatives Next, the relative permittivity and dielectric loss tangent of the esterified α-1,3-glucan derivative of the present invention are measured and the electrical properties are evaluated. It was.
　エステル化α－１，３－グルカン誘導体として、実施例１で合成したα-1,3-Glucan-Acetate (Ac)、α-1,3-Glucan-Hexanoate (Hex)、α-1,3-Glucan-Ibutyrate (iBu)、α-1,3-Glucan-Pivalate (Pi)を用いた。 Α-1,3-Glucan-Acetate (Ac), α-1,3-Glucan-Hexanoate (Hex), α-1,3- synthesized in Example 1 as esterified α-1,3-glucan derivatives. Glucan-Ibutyrate (iBu) and α-1,3-Glucan-Pivalate (Pi) were used.
　実験条件は、以下のとおりである。
試験法：　自動平衡ブリッジ法（LCRメータ法）
試験装置：LCRメータHP4284A（アジレントテクノロジー製）
TO-19恒温槽（安藤電機製）
SE-70形固体用電極（安藤電機製）
試験片寸法：5 cm角
電極：主電極径10.5 mm
測定環境：23℃、50℃、100℃、150℃
測定周波数：10 kHz
厚み計測：マイクロメータ
手順：　銅板上に試料を載せて、主電極部を円筒状の金属Alで押さえつけた。銅板上に張り付けた温度センサーにより温度を測定した。 The experimental conditions are as follows.
Test method: Automatic equilibrium bridge method (LCR meter method)
Test equipment: LCR meter HP4284A (manufactured by Agilent Technologies)
TO-19 constant temperature bath (manufactured by Ando Electric)
SE-70 type solid electrode (manufactured by Ando Electric)
Specimen size: 5 cm Square electrode: Main electrode diameter 10.5 mm
Measurement environment: 23 ℃, 50 ℃, 100 ℃, 150 ℃
Measurement frequency: 10 kHz
Thickness measurement: Micrometer Procedure: A sample was placed on a copper plate, and the main electrode was pressed with a cylindrical metal Al. The temperature was measured by a temperature sensor attached on a copper plate.
　測定結果を以下の表７に示す。
Figure JPOXMLDOC01-appb-T000011
 The measurement results are shown in Table 7 below.
Figure JPOXMLDOC01-appb-T000011
　表７に示すように、２種類のα-1,3-Glucan分岐状エステル誘導体（PiとiBu）の比誘電率は、直鎖状エステル誘導体のα-1,3-Glucan-Acより小さく、α-1,3-Glucan-Hexと同程度であった。分岐状エステル誘導体は、直鎖状エステル誘導体（α-1,3-Glucan-Hex , Tg=49℃）に比べ、Tgが200℃以上と非常に高い熱安定性を持っている。すなわち、分岐状エステル誘導体は、非常に高い耐熱性（寸法安定性）と高い絶縁性を併せ持つ材料であった。また、いずれのα-1,3-Glucanエステル誘導体においても、温度が高いほど、低い誘電率（高い絶縁性）を示した。誘電率の温度依存性のグラフを図５に示す。 As shown in Table 7, the relative permittivity of the two types of α-1,3-Glucan branched ester derivatives (Pi and iBu) is smaller than that of the linear ester derivative α-1,3-Glucan-Ac. It was similar to α-1,3-Glucan-Hex. The branched ester derivative has extremely high thermal stability with a Tg of 200 ° C or higher as compared with the linear ester derivative (α-1,3-Glucan-Hex, Tg = 49 ° C). That is, the branched ester derivative was a material having both extremely high heat resistance (dimensional stability) and high insulating properties. In addition, the higher the temperature, the lower the dielectric constant (higher insulating property) of all the α-1,3-Glucan ester derivatives. A graph of the temperature dependence of the dielectric constant is shown in FIG.
　さらに、α-1,3-Glucan分岐状エステル誘導体のような高い耐熱性と絶縁性を両立した物性は、従来のプラスチックではほとんど実現されていない。例えば、一般に、耐熱性絶縁体として利用されているトーロン（登録商標）などの芳香族ポリマーのガラス転移点は、200℃以上であり、α-1,3-Glucan分岐状エステル誘導体と同等、もしくはより高い耐熱性を持つ。しかし、図５中に示すように、それらの比誘電率は4程度であり、絶縁性はα-1,3-Glucan分岐状エステル誘導体に劣る。また、ポリエチレンやポリプロピレンの誘電率は、α-1,3-Glucan分岐状エステル誘導体より低いが、それらのガラス転移点はα-1,3-Glucan分岐状エステルより著しく低い。このように、α-1,3-Glucan分岐状エステル誘導体は、新規な耐熱性絶縁体として有望であることが分かった。 Furthermore, physical properties that have both high heat resistance and insulating properties, such as α-1,3-Glucan branched ester derivatives, have hardly been realized with conventional plastics. For example, the glass transition point of an aromatic polymer such as Toron (registered trademark), which is generally used as a heat-resistant insulator, is 200 ° C. or higher, which is equivalent to or equal to that of an α-1,3-Glucan branched ester derivative. Has higher heat resistance. However, as shown in FIG. 5, their relative permittivity is about 4, and their insulating properties are inferior to those of α-1,3-Glucan branched ester derivatives. The dielectric constant of polyethylene and polypropylene is lower than that of α-1,3-Glucan branched ester derivatives, but their glass transition points are significantly lower than those of α-1,3-Glucan branched ester derivatives. As described above, the α-1,3-Glucan branched ester derivative was found to be promising as a novel heat-resistant insulator.

Claims (12)

  1. 　α－１，３－グリコシド結合によりグルコース単位が直鎖状に重合した構造を有する、式（１）で表されるエステル化α－１，３－グルカン誘導体：
    Figure JPOXMLDOC01-appb-C000001
     （式中、各Ｒは、それぞれ同一でも異なっていてもよい、２分岐又は３分岐のアルキル鎖を有する炭素数４～２０のアシル基であり、ｎは、１００～２０，０００である。）。     An esterified α-1,3-glucan derivative represented by the formula (1), which has a structure in which glucose units are linearly polymerized by an α-1,3-glycosidic bond:
    Figure JPOXMLDOC01-appb-C000001
     (In the formula, each R is an acyl group having 4 to 20 carbon atoms having a bifurcated or trifurcated alkyl chain, which may be the same or different, and n is 100 to 20,000.) ..
  2. 　前記Ｒが、イソブチリル基、イソバレリル基、イソヘキサノイル基、イソヘプタノイル基、及びピバロイル基よりなる群から選択される、請求項１に記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to claim 1, wherein R is selected from the group consisting of an isobutyryl group, an isovaleryl group, an isohexanoyl group, an isoheptanoyle group, and a pivaloyl group.
  3. 　融点が２５０～３４０℃であり、かつ、ガラス転移温度が１００～２１０℃の範囲である、請求項１又は２に記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to claim 1 or 2, which has a melting point of 250 to 340 ° C. and a glass transition temperature in the range of 100 to 210 ° C.
  4. 　ガラス転移温度が１５０℃以上であって、かつ融点とガラス転移温度との差が１１０℃以内である、請求項３に記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to claim 3, wherein the glass transition temperature is 150 ° C. or higher, and the difference between the melting point and the glass transition temperature is 110 ° C. or lower.
  5. 　２００～２８０℃の領域において粘度が５０ｋＰａ・ｓ以下となる、請求項１～４のいずれかに記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to any one of claims 1 to 4, which has a viscosity of 50 kPa · s or less in the region of 200 to 280 ° C.
  6. 　ガラス転移温度と融点との間の領域において粘度が５０ｋＰａ・ｓ以下となる、請求項１～５のいずれかに記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to any one of claims 1 to 5, wherein the viscosity is 50 kPa · s or less in the region between the glass transition temperature and the melting point.
  7. 　重量平均分子量（Ｍｗ）が、１．８×１０５以上である、請求項１～６のいずれかに記載のエステル化α－１，３－グルカン誘導体。 The weight average molecular weight (Mw) is 1.8 × 10 5 or more, esterified alpha-1,3-glucan derivative according to any one of claims 1 to 6.
  8. 　多分散度（Ｍｗ／Ｍｎ）が、２．０～３．０の範囲である、請求項１～７のいずれかに記載のエステル化α－１，３－グルカン誘導体。 The esterified α-1,3-glucan derivative according to any one of claims 1 to 7, wherein the polydispersity (Mw / Mn) is in the range of 2.0 to 3.0.
  9. 　請求項１～８のいずれかに記載のエステル化α－１，３－グルカン誘導体を含む構造体。 A structure containing the esterified α-1,3-glucan derivative according to any one of claims 1 to 8.
  10. 　前記構造体が、射出成形、圧縮成形、ブロー成形、インフレーション成形エンゲル成形、押出成形、押出ラミネート成形、回転成形、カレンダー成形、真空成型、スタンピング成形、スプレーアップ成形、積層成形、注形法、注入成形、手積み成形、低圧成形、トランスファー成形、発泡成形、ブロー成形、又はＴダイ法により成形されてなる、請求項９に記載の構造体。 The structure is injection molding, compression molding, blow molding, inflation molding engel molding, extrusion molding, extrusion laminating molding, rotary molding, calendar molding, vacuum molding, stamping molding, spray-up molding, lamination molding, casting method, injection. The structure according to claim 9, wherein the structure is formed by molding, manual stacking, low pressure molding, transfer molding, foam molding, blow molding, or T-die method.
  11. 　前記構造体がフィルムである、請求項９又は１０に記載の構造体。 The structure according to claim 9 or 10, wherein the structure is a film.
  12. 　３００ｎｍにおいて４０％以上の透過率を有する、請求項１１に記載の構造体。 The structure according to claim 11, which has a transmittance of 40% or more at 300 nm.
PCT/JP2020/019991 2019-05-24 2020-05-20 BRANCHED CHAIN, ESTERIFIED α-1,3-GLUCAN DERIVATIVE WO2020241421A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2021522271A JPWO2020241421A1 (en) 2019-05-24 2020-05-20

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019097431 2019-05-24
JP2019-097431 2019-05-24

Publications (1)

Publication Number Publication Date
WO2020241421A1 true WO2020241421A1 (en) 2020-12-03

Family

ID=73552202

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/019991 WO2020241421A1 (en) 2019-05-24 2020-05-20 BRANCHED CHAIN, ESTERIFIED α-1,3-GLUCAN DERIVATIVE

Country Status (2)

Country Link
JP (1) JPWO2020241421A1 (en)
WO (1) WO2020241421A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09316133A (en) * 1996-05-31 1997-12-09 Meito Sangyo Kk Dextran ester copolymer
WO2018098065A1 (en) * 2016-11-22 2018-05-31 E.I. Du Pont De Nemours And Company Polyalpha-1,3-glucan esters and articles made therefrom
JP2018102249A (en) * 2016-12-27 2018-07-05 国立大学法人 東京大学 METHOD FOR SYNTHESIZING HIGH MOLECULAR WEIGHT α-1,3-GLUCAN

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09316133A (en) * 1996-05-31 1997-12-09 Meito Sangyo Kk Dextran ester copolymer
WO2018098065A1 (en) * 2016-11-22 2018-05-31 E.I. Du Pont De Nemours And Company Polyalpha-1,3-glucan esters and articles made therefrom
JP2018102249A (en) * 2016-12-27 2018-07-05 国立大学法人 東京大学 METHOD FOR SYNTHESIZING HIGH MOLECULAR WEIGHT α-1,3-GLUCAN

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
SAKARIN PUANGLEK ET AL: "Thermal and mechanical properties of tailor-made unbranched α-1,3-glucan esters with various carboxylic acid chain length", CARBOHYDRATE POLYMERS, vol. 169, August 2017 (2017-08-01), pages 245 - 254, XP055766615, DOI: 10.1016/j.carbpol.2017.04.015 *
SEN-I GAKKAI PREPRINTS, vol. 74, no. 1, 5 June 2019 (2019-06-05), pages 257 *
TAKAHIRO DANJO ET AL: "Syntheses of cellulose branched ester derivatives and their properties and structure analyses", POLYMER, vol. 137, 5 January 2018 (2018-01-05), pages 358 - 363, XP055766607, DOI: 10.1016/j.polymer.2018.01.009 *
YUYA FUKATA ET AL: "Synthesis of α-1,3-Glucan branched ester derivatives with excellent thermal stability and thermoplasticity", POLYMER DEGRADATION AND STABILITY, vol. 177, no. 109130, 1 July 2020 (2020-07-01), pages 1 - 8, XP055766619, DOI: 10.1016/j.polymdegradstab.2020.109130 *
ZHAI WENJIA ET AL: "Synthesis and physical properties of Curdlan branched Ester derivatives", JOURNAL OF POLYMER RESEARCH, vol. 25, no. 3, 181, 11 October 2017 (2017-10-11), pages 1 - 7, XP036478227, DOI: 10.1007/s10965-017-1348-7 *

Also Published As

Publication number Publication date
JPWO2020241421A1 (en) 2020-12-03

Similar Documents

Publication Publication Date Title
Marubayashi et al. Curdlan ester derivatives: Synthesis, structure, and properties
Hu et al. Bio-based poly (butylene 2, 5-furandicarboxylate)-b-poly (ethylene glycol) copolymers with adjustable degradation rate and mechanical properties: Synthesis and characterization
Hu et al. Fully bio-based poly (propylene succinate-co-propylene furandicarboxylate) copolyesters with proper mechanical, degradation and barrier properties for green packaging applications
JP6817972B2 (en) Preparation of poly α-1,3-glucan ester using cyclic organic anhydride
FI112083B (en) Viscosity modified lactide polymer blend and its preparation process
Puanglek et al. Thermal and mechanical properties of tailor-made unbranched α-1, 3-glucan esters with various carboxylic acid chain length
Enomoto-Rogers et al. Syntheses and characterization of konjac glucomannan acetate and their thermal and mechanical properties
Yu et al. Crystallization behavior and hydrophobic properties of biodegradable ethyl cellulose-g-poly (3-hydroxybutyrate-co-3-hydroxyvalerate): The influence of the side-chain length and grafting density
Enomoto-Rogers et al. Synthesis of xylan-graft-poly (l-lactide) copolymers via click chemistry and their thermal properties
Teramoto et al. Plasticization of cellulose diacetate by graft copolymerization of ε‐caprolactone and lactic acid
JP2017193667A (en) β-1,3-GLUCAN DERIVATIVE, METHOD FOR PRODUCING THE SAME, AND MOLDED BODY
Fukata et al. Synthesis of α-1, 3-Glucan branched ester derivatives with excellent thermal stability and thermoplasticity
KR20190082887A (en) Molded articles comprising polysaccharides
Vidéki et al. Grafting of caprolacton to cellulose acetate by reactive processing
WO2021246006A1 (en) β-1,3-GLUCAN ESTER DERIVATIVE AND β-1,4-GLUCAN ESTER DERIVATIVE
Zhai et al. Synthesis and properties of curdlan branched and linear mixed ester derivatives
Gericke et al. α-1, 3-Glucan benzoate–A novel polysaccharide derivative
Danjo et al. Syntheses and properties of glucomannan acetate butyrate mixed esters
Sun et al. Succinoylation of wheat straw hemicelluloses with a low degree of substitution in aqueous systems
WO2020241421A1 (en) BRANCHED CHAIN, ESTERIFIED α-1,3-GLUCAN DERIVATIVE
Lee et al. Synthesis and characterization of dextrin derivatives by heterogeneous esterification
Seok et al. Synthesis and characterization of paramylon propionate-graft-poly (lactic acid) and paramylon propionate-graft-poly (ε-caprolactone)
Lee et al. One-pot synthesis of cellulose ester–graft–polylactide copolymers in an ionic liquid and the effect of graft-chain composition on their thermoplasticities and enzymatic degradabilities
Caner et al. Preparation of hetero-armed POSS-cored star-shaped PCL-PLA/PLA composites and effect of different diisocyanates as compatibilizer
WO2018147144A1 (en) Coating material containing dextran ester derivative

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20813912

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021522271

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20813912

Country of ref document: EP

Kind code of ref document: A1