Molding material and molding

Abstract

To provide a molding material that has excellent moldability and can give a molding having excellent transparency.SOLUTION: This invention relates to a molding material containing a polymer having a pentose derivative-derived unit. This invention also relates to a molding obtained by the molding material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a molding material and a molded article using the molding material. [Background technology]

[0002] In recent years, plant-derived plastics and biodegradable plastics have been attracting attention as a means of combating marine pollution and global warming. Plant-derived components are mainly composed of three types: cellulose, hemicellulose, and lignin. Of these, cellulose is well known as a biodegradable material, but it has been reported that hemicellulose is even more biodegradable than cellulose.

[0003] Technologies for utilizing cellulose as a molding material are being investigated. For example, Patent Document 1 discloses a method for producing a resin molded product in which cellulose nanofibers are blended with the resin.

[0004] Patent Document 2 discloses a technique for polymerizing cellulose acetate and a fluorene-based compound to produce a material for injection molding. In addition, Patent Document 2 also proposes the use of wood flour itself, hemicellulose, and lignin.

[0005] Patent Document 3 proposes an unsaturated polyester resin containing an unsaturated polyester and a crosslinkable monomer, in which a material made from a wood-based material is used as part of the main chain of the unsaturated polyester.

[0006] Patent Document 4 discloses a molded body reinforced with natural fibers. This molded body is made of a molding material obtained after plastic or thermoplastic molding of a raw material mixture containing residual moisture, and is solidified after the final molding step. The molded body contains at least one plant or animal fiber material, at least one thermoplastic or thermosetting plastic, and at least one water-binding biopolymer and / or at least one water-binding biomonomer. Patent Document 4 also describes that hemicellulose can be used as the plant fiber, biopolymer, and biomonomer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2018-43405 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-86254 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-239906 [Patent Document 4] Special Publication No. 2005-506413 Summary of the Invention [Problem to be solved by the invention]

[0008] In the materials used for the resin molded products disclosed in Patent Document 1, the mixing ratio of cellulose nanofibers to polypropylene is limited to a maximum of 20% due to fluidity issues during injection molding, and it has been difficult to increase the proportion of plant-derived materials.

[0009] In contrast, Patent Document 2 shows that it is possible to increase the proportion of cellulose acetate, a plant-derived material, to 70-90%, but there are problems in that fluorene itself is expensive and the light transmittance of the molded body is insufficient depending on the application.

[0010] Patent Document 3 discloses a method for synthesizing a material made from lignin, cellulose, and hemicellulose in wood-based materials in Example 3. However, there is room for improvement in the moldability of the resin obtained in Patent Document 3, and the light transmittance of the molded body is also insufficient.

[0011] Patent Document 4 discloses a method of using hemicellulose as a biopolymer / biomonomer, but does not specifically disclose the use of hemicellulose, nor does it clarify its moldability, compatibility with conventional plastics, or transparency.

[0012] Therefore, the problem that the present invention aims to solve is to provide a molding material that can be used to form molded bodies that have excellent moldability and transparency, while effectively utilizing hemicellulose, a plant-derived material that has hardly been used industrially. [Means for solving the problem]

[0013] In order to solve the above problems, the present invention has the following configuration. [1] A molding material containing a polymer containing units derived from a pentose derivative. [2] The molding material according to [1], wherein the content of the pentose derivative-derived units is 20% by mass or more based on the total mass of the molding material. [3] The molding material according to [1] or [2], wherein the pentose derivative-derived unit is a unit derived from a monomer represented by the following formula (1): [ka] In formula (1), R 1 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and there are multiple R 1 may be the same or different. [4] The molding material according to [1] or [2], wherein the pentose derivative-derived unit is a unit derived from a monomer represented by the following formula (2): [ka] In formula (2), R 1 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and there are multiple R 1 may be the same or different; R 5 represents a hydrogen atom, an alkyl group, a fluorine atom, a bromine atom, or an iodine atom; Y 1 represents a single bond or a linking group. [5] The molding material according to any one of [1] to [4], wherein the pentose derivative-derived unit is a hemicellulose-derived unit. [6] The molding material according to any one of [1] to [5], further comprising a pentose derivative. [7] The molding material according to any one of [1] to [6], further comprising a resin component. [8] The molding material according to any one of [1] to [7], which is for introducing metals. [9] A molded article obtained by molding the molding material according to any one of [1] to [8].

[10] The molded article according to [9], which has a total light transmittance of 80% or more.

[11] The molded article according to [9] or

[10] , further comprising a metal.

[0014] The present invention may also have the following configuration.

[0015]

[0101] A molding material comprising at least one component selected from monosaccharide or polysaccharide derivatives in which pentose is chemically modified.

[0102] A molding material according to

[0101] , wherein the monosaccharide or polysaccharide derivative in which the pentose is chemically modified has a structure represented by the following formula (1) or contains a unit derived from the structure represented by the following formula (1). [ka] In formula (1), R 1 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R 1 may be the same or different.

[0103] A molding material according to

[0101] , wherein the monosaccharide or polysaccharide derivative in which the pentose is chemically modified has a structure represented by the following formula (2) or contains a unit derived from the structure represented by the following formula (2). [ka] R 1each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and multiple R1s may be the same or different; R 5 represents a hydrogen atom, an alkyl group, a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom; Y 1 represents a single bond or a linking group.

[0104]

[0101] to

[0103] A molded product obtained by molding the molding material described in any one of the above.

[0105]

[0101] to

[0103] A molding method comprising a step of molding the molding material according to any one of the above to obtain a molded product.

[0106] A molding method described in

[0105] , further comprising a step of introducing a metal.

[0107] A molding method described in

[0105] or

[0106] , wherein at least one component selected from monosaccharide or polysaccharide derivatives whose pentoses are chemically modified is obtained by decomposing hemicellulose. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a molding material that effectively utilizes hemicellulose and that can form a molded article that has excellent moldability and transparency. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, substituents that are not specified as substituted or unsubstituted mean that the group may have any substituent.

[0018] (molding material) The molding material of the present invention relates to a molding material containing a polymer containing a unit derived from a pentose derivative. The pentose derivative is at least one type selected from monosaccharide or polysaccharide derivatives in which the pentose has been chemically modified. In this specification, the term "unit derived from a pentose derivative" refers to a unit derived from a monosaccharide or polysaccharide derivative in which the pentose has been chemically modified. The molding material of the present invention may also contain a monosaccharide or polysaccharide derivative in which the pentose has been chemically modified.

[0019] In the molding material of the present invention, the content of pentose derivative-derived units (sugar derivative content) is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, and particularly preferably 40% by mass or more, relative to the total mass of the molding material. The content of pentose derivative-derived units (sugar derivative content) may be 100% by mass. By setting the content of pentose derivative-derived units (sugar derivative content) within the above range, the biodegradability of molded articles formed from the molding material can be more effectively improved.

[0020] Here, the content of units derived from pentose derivatives (sugar derivative content) in the molding material of the present invention is a value calculated by the following calculation formula. Content of pentose derivative-derived units (mass%) = mass of polymer consisting of pentose derivative-derived units / mass of molding material × 100 When the polymer containing pentose derivative-derived units is a copolymer of pentose derivative-derived units and other structural units, the content of pentose derivative-derived units is calculated by the following formula. Content of pentose derivative-derived units (mass%) = molecular weight of pentose derivative-derived units × average number of pentose derivative-derived units in copolymer / weight average molecular weight of molding material

[0021] The molding material of the present invention has the above-described configuration and therefore has excellent moldability. Here, the moldability of the molding material can be evaluated based on the properties of the molded body after the molding material is heated and pressure molded. Specifically, the moldability can be evaluated as good when a molded body without cracks and with a good appearance is obtained. Furthermore, molded bodies formed from the molding material of the present invention also have excellent transparency. The transparency of the molded body can be determined from the total light transmittance of the molded body. Specifically, the transparency of the molded body can be evaluated as good when the total light transmittance measured by the method described in JIS K 7105 is 80% or more.

[0022] Furthermore, molded articles formed from the molding material of the present invention are biodegradable because they contain units derived from pentose derivatives, and are expected to be used as materials that can suppress marine pollution and global warming.

[0023] (pentose derivatives) Pentose derivatives (monosaccharide or polysaccharide derivatives in which pentoses have been chemically modified) are pentose monosaccharides or polysaccharides in which multiple pentoses are glycosidicly bonded, in which at least one hydroxyl group has been modified with a substituent. Examples of the substituent include those described below, such as alkyl groups, acyl groups, aryl groups, phosphoryl groups, and trimethylsilyl groups. In this way, modifying some of the hydroxyl groups of the pentose with a substituent weakens the hydrogen bonding strength between the hydroxyl groups, thereby improving compatibility in molding materials and fluidity during molding, thereby improving moldability.

[0024] Preferred examples of monosaccharide derivatives in which pentoses are chemically modified include xylose derivatives, and preferred examples of polysaccharide derivatives in which pentoses are chemically modified include hemicellulose derivatives and xylooligosaccharide derivatives, with xylooligosaccharide derivatives being preferred.

[0025] It is also preferable that the pentose derivative is a material derived from hemicellulose. That is, it is preferable that the pentose derivative-derived unit is a unit derived from hemicellulose. By obtaining a pentose derivative from a material derived from hemicellulose, hemicellulose can be effectively utilized. In addition, hemicellulose is known to be highly biodegradable, and since both cellulose and cellulose acetate are biodegradable, using a material derived from hemicellulose can more effectively increase biodegradability.

[0026] The pentose derivative-derived unit is preferably a unit derived from a monomer represented by the following formula (1) or (2): That is, the polymer contained in the molding material preferably contains a unit derived from a monomer represented by the following formula (1) or (2):

[0027] [ka]

[0028] In formula (1), R 1 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R 1 may be the same or different, provided that R 1 At least one of is an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group.

[0029] [ka]

[0030] In formula (2), R 1 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R 1 may be the same or different. 5 represents a hydrogen atom, an alkyl group, a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom. 1represents a single bond or a linking group.

[0031] The polymer containing a pentose derivative-derived unit may be a sugar polymer having a side chain. Here, the sugar polymer may be one in which a sugar chain constitutes the main chain of the polymer, or one in which a component other than the sugar chain constitutes the main chain of the polymer. When a component other than the sugar constitutes the main chain of the polymer, the sugar or sugar chain constitutes the side chain of the polymer. Furthermore, when the sugar polymer has sugar chains in the main chain and the side chain, either the pentose in the main chain or the side chain may be chemically modified.

[0032] When a component other than sugar constitutes the main chain of the polymer, the pentose derivative-derived unit is preferably a unit represented by the following formula (3). [ka]

[0033] In formula (3), R 1 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a phosphoryl group, or a trimethylsilyl group, and the alkyl group includes a sugar derivative group. 1 may be the same or different; R' is a hydrogen atom, -OR 1 , amino group or -NR 1 Represents 2. R″ is a hydrogen atom or —OR 1 Represents. In addition, R in R' and R" 1 is R in Equation (3). 1 The same applies to the preferred range. R 5 represents a hydrogen atom, an alkyl group, a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom, and there are multiple R 5 may be the same or different. 5 is preferably a hydrogen atom, an alkyl group, a fluorine atom, a bromine atom or an iodine atom. X 1 and Y 1each independently represents a single bond or a linking group, and a plurality of X 1 may be the same or different, and there may be multiple Y 1 may be the same or different.

[0034] When the sugar chain constitutes the main chain of the polymer, the pentose derivative-derived unit is preferably a unit represented by the following formula (4). [ka]

[0035] In formula (4), R 201 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a phosphoryl group, or a trimethylsilyl group, and a plurality of R 201 may be the same or different. R' is a hydrogen atom, -OR 1 , amino group or -NR 1 Represents 2. R″ is a hydrogen atom or —OR 1 Represents. In addition, R in R' and R" 1 is R in Equation (3). 1 The same applies to the preferred range. * indicates R 201 Instead of R 201 represents the bonding site with one of the oxygen atoms to which it is bonded.

[0036] When the pentose derivative-derived unit is a unit represented by the above formula (3), in formula (3), R 1 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a phosphoryl group, or a trimethylsilyl group. 1 At least one of R is preferably an alkyl group, an acyl group, an aryl group, a phosphoryl group, or a trimethylsilyl group. 1 The alkyl group in may be an alkyl group having a substituent, and such an alkyl group includes a sugar derivative group, so that the sugar portion (sugar derivative moiety) of formula (3) may further have a linear or branched sugar derivative moiety.1 are preferably each independently a hydrogen atom or an acyl group having 1 to 3 carbon atoms. Note that multiple R1s may be the same or different.

[0037] In the above formula (3), R 1 When is an alkyl group or an acyl group, the number of carbon atoms therein can be appropriately selected depending on the purpose. For example, the number of carbon atoms therein is preferably 1 or more, and is preferably 200 or less, more preferably 100 or less, even more preferably 20 or less, and particularly preferably 4 or less.

[0038] R in the above formula (3) 1 Specific examples of include acyl groups such as acetyl, propanoyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, octanoyl, chloroacetyl, trifluoroacetyl, cyclopentanecarbonyl, cyclohexanecarbonyl, benzoyl, methoxybenzoyl, and chlorobenzoyl; and alkyl groups such as methyl, ethyl, propyl, butyl, and t-butyl. Among these, methyl, ethyl, acetyl, propanoyl, butyryl, isobutyryl, and benzoyl are preferred, with acetyl and propanoyl being particularly preferred.

[0039] In formula (3), R' is a hydrogen atom, -OR 1 , amino group, or -NR 1 Represents 2. R 1 Specific examples of R in the above formula (3) include 1 Preferred structures of R' are -H, -OH, -OAc, -OCOC2H5, -OCOC6H5, -NH2, -NHCOOH, and -NHCOCH3, more preferred structures of R' are -H, -OH, -OAc, -OCOC2H5, and -NH2, and particularly preferred structures of R' are -OH, -OAc, and -OCOC2H5.

[0040] In formula (3), R″ is a hydrogen atom or —OR 1 Represents R1 Specific examples of R in the above formula (3) include 1 Preferred structures of R" are -H, -OAc, and -OCOC2H5, and more preferred structures of R" are -H, -OAc, and -OCOC2H5.

[0041] In formula (3), R 5 represents a hydrogen atom, an alkyl group, a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom, and multiple R5s may be the same or different. 5 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

[0042] In formula (3), X 1 and Y 1 each independently represents a single bond or a linking group, and a plurality of X 1 may be the same or different, and there may be multiple Y 1 may be the same or different. X 1 is a linking group, X 1 Examples of the X include groups containing an alkylene group, -O-, -NH2-, and a carbonyl group. 1 is preferably a single bond or an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Y 1 is a linking group, Y 1 Examples of Y include groups containing an alkylene group, a phenylene group, -O-, -C(=O)O-, etc. 1 may be a linking group combining these groups. 1 is preferably one of the following linking groups (a) to (e). [ka]

[0043] In the linking groups (a) to (e), the * symbol indicates the bonding site with the main chain, and the * symbol indicates the bonding site with the sugar unit of the side chain.

[0044] In this specification, R in formula (3) 1 When is an alkyl group, the alkyl group may be an alkyl group having a substituent, and such alkyl groups include sugar derivative groups. Therefore, the sugar moiety (sugar derivative moiety) of formula (3) may further have a linear or branched sugar derivative moiety. In other words, the pentose derivative-derived unit may be a unit represented by formula (3'). [ka]

[0045] In formula (3'), R 1 , R 5 , R', R'', X 1 and Y 1 is R in Equation (3). 1 , R 5 , R', R'', X 1 and Y 1 The same applies. r is 2 or more and 1500 or less. The * mark in formula (3') indicates that R 1 or R 1 Instead of R 1 represents the bonding site with one of the oxygen atoms to which it is bonded.

[0046] In addition, r in formula (3') represents the degree of polymerization of the sugar derivative portion. The average degree of polymerization of the sugar derivative portion can be calculated using the following measurement method. First, a solution containing pentose derivatives is kept at 50°C and centrifuged at 15,000 rpm for 15 minutes to remove insoluble matter. Then, the total sugar amount and the reducing sugar amount (both converted to xylose) of the supernatant are measured. The average degree of polymerization is calculated by dividing the total sugar amount by the reducing sugar amount. If the above measurement method cannot be used, gel permeation chromatography, size exclusion chromatography, light scattering, viscosity method, end group quantification method, sedimentation velocity method, MULDI-TOF-MS method, structural analysis by NMR, etc. may also be used.

[0047] When measuring the average degree of polymerization of sugar derivatives after polymer synthesis, 1 The integral value of the peak (around 3.3-5.5 ppm) derived from the sugar chain and the integral value of the peak derived from other components of the pentose derivative are calculated by H-NMR, and the average degree of polymerization is calculated from the ratio of these integral values. 1 If is not a hydrogen atom, -OR 1 The integral value of the peak derived from the -OR group can also be used (however, in this case, 1 Group R 1 is not a glycan).

[0048] When polymerizing a polymer containing a pentose derivative-derived unit represented by formula (3), it may be a homopolymer or a copolymer obtained by mixing with other known monomer materials. The known monomer materials are not particularly limited, but methyl methacrylate, styrene, lactic acid, propylene, terephthalic acid, ethylene glycol, etc. can also be used.

[0049] When the pentose derivative-derived unit is a unit represented by the above formula (4), in formula (4), R 201 each independently represents a hydrogen atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R 201 may be the same or different. 201 At least one of the groups is preferably an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group.

[0050] In formula (4), R 201 The preferred ranges of R, R′, and R″ are 1 The preferred ranges of R, R′, and R″ are the same as those of R′, R″.

[0051] The polymer contained in the molding material of the present invention may be a copolymer containing structural units of formula (3) and formula (4). Furthermore, the polymer contained in the molding material of the present invention may contain other structural units in addition to the structural units of formula (3) and / or formula (4).

[0052] The molding material of the present invention contains a polymer containing the above-described pentose derivative-derived units. The weight-average molecular weight of the polymer is preferably 150 or more, more preferably 200 or more, and even more preferably 300 or more. The weight-average molecular weight of the polymer is preferably 2,000,000 or less, more preferably 1,000,000 or less, and even more preferably 800,000 or less. The weight-average molecular weight of the polymer is a value measured by gel permeation chromatography (GPC) using polystyrene standards.

[0053] (resin component) The molding material of the present invention may contain a resin component in addition to the polymer containing units derived from a pentose derivative. Examples of the resin component include, but are not limited to, PMMA, PC, PS, polylactic acid, polypropylene, PET, PTFE, polyamide, and PFA. Because the molding material of the present invention uses a chemically modified pentose, its compatibility with the resin component is significantly improved compared to monosaccharides or polysaccharides composed of unmodified pentose.

[0054] The resin component may be included as a copolymerization component constituting a polymer containing pentose derivative-derived units. In this case, the polymer is formed by copolymerizing the pentose derivative-derived units with units derived from the monomers constituting the resin. In this way, the resin component may be included as a copolymerization component constituting a polymer containing pentose derivative-derived units. Such a copolymer may be a random copolymer or a block copolymer.

[0055] The resin component may also be a polymer that is added separately from the polymer containing pentose derivative-derived units. In such a case, the resin component may be added as a plastic material. Examples of the plastic material include materials similar to those of the resin component described above. When the resin component is a polymer that is added separately from the polymer containing pentose derivative-derived units, the polymer containing pentose derivative-derived units and the polymer consisting of the resin component are melt-mixed.

[0056] (optional ingredient) In addition to the above components, the molding material of the present invention may contain a crosslinking agent, a polymerization initiator, an additive for improving compatibility, a colorant, a thickener, a shrinkage reducing agent, a reinforcing material, an inorganic filler, etc. The crosslinking agent or polymerization initiator may be one that crosslinks or polymerizes groups substituted on hydroxyl groups of monosaccharides or polysaccharides, or may be one that crosslinks or polymerizes materials contained in the molding material other than the derivatives of monosaccharides or polysaccharides.

[0057] The molding material of the present invention may contain a pentose derivative as a monomer component in addition to the polymer containing a pentose derivative-derived unit. By containing a pentose derivative as a monomer component, the moldability of the molding material can be improved.

[0058] In the process of forming a molded body from the molding material of the present invention, a metal component may be introduced. The molded body into which the metal component is introduced can exhibit electrical conductivity, and is therefore preferably used in applications requiring electrical conductivity. In this way, the molding material of the present invention may be a material for introducing a metal.

[0059] (Method for synthesizing polymers containing units derived from pentose derivatives) Polymers containing pentose derivative-derived units can be synthesized by known polymerization methods such as living radical polymerization, living anionic polymerization, and atom transfer radical polymerization. For example, in the case of living radical polymerization, a polymer can be obtained by reacting a monomer such as a pentose derivative with a polymerization initiator such as AIBN (α,α'-azobisisobutyronitrile). In the case of living anionic polymerization, a polymer can be obtained by reacting a monomer with butyllithium in the presence of lithium chloride. Note that although this example shows an example of synthesis using living anionic polymerization, the synthesis is not limited thereto, and the polymer can be appropriately synthesized by any of the above-mentioned synthesis methods or known synthesis methods.

[0060] (Method for extracting pentose materials) The pentose material used in synthesizing the polymer containing pentose derivative-derived units may be obtained by synthesis, or may be obtained by combining a step of extraction from woody or herbaceous plant-derived material. When a method of extraction from lignocellulose derived from woody or herbaceous plants is adopted, the extraction method described in JP 2012-100546 A can be used. Xylan can be extracted, for example, by the method disclosed in JP 2012-180424 A.

[0061] (Chemical modification of pentose materials) The pentose derivative is preferably used after modifying the OH group of the pentose material obtained by the above extraction method, etc. by acetylation, halogenation, etc. For example, when an acetyl group is introduced, the acetylated pentose derivative can be obtained by reacting the pentose material with acetic anhydride.

[0062] (Molded body) The present invention also relates to a molded article obtained by molding the above-mentioned molding material. The molding material is preferably obtained by molding the above-mentioned molding material under heat and pressure. The molded article may also be a molded article obtained by curing the above-mentioned molding material by irradiating it with an active energy source.

[0063] The molded article of the present invention has a total light transmittance of preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. Because the molded article of the present invention has such excellent transparency, it is also preferably used as an optical component.

[0064] The molded article of the present invention may further contain the above-mentioned optional components and metals. The metal contained in the molded article is introduced in the metal introduction step described below. The molded article into which the metal has been introduced can exhibit electrical conductivity, and is therefore preferably used in applications requiring electrical conductivity.

[0065] Examples of uses of the molded article include housings for electronic devices and home appliances, reinforcing materials, civil engineering and building material parts, interior parts, automobile and motorcycle parts, aircraft parts, railway vehicle parts, daily necessities, packaging materials, etc., and among these, the molded article is suitable for disposable uses. It is desirable that the molded article of the present invention does not leak into the natural environment, but even if it does leak out, it can be decomposed in the natural environment, thereby reducing the burden on the environment.

[0066] (Molding method) The molding method for the molded article of the present invention is not particularly limited, and examples thereof include injection molding, extrusion molding, blow molding, vacuum molding, pressure molding, cast molding, foam molding, powder molding, photomolding, compression molding, etc. Among these, injection molding, extrusion molding, foam molding, and powder molding are preferred molding methods.

[0067] The molded article of the present invention can also be formed by photopolymerization. In this case, it is preferable to use a photopolymerizable material as the molding material. When forming a molded article by photopolymerization, the molding material of the present invention can be poured into a mold having a recessed or fine patterned surface, and then irradiated with light to obtain a molded article. Alternatively, a substrate can be coated with the molding material to a desired thickness, followed by irradiating with light to obtain a molded article coated with the molding material. Alternatively, the molding material can be applied to a so-called nanoimprinting technique, in which the molding material is coated on a base material to form an uncured resin film, and the resin film is photopolymerized while a mold is pressed against the resin film. When using the molding material of the present invention for nanoimprinting, it is preferable to add a monomer component of a pentose derivative to reduce the viscosity of the molding material before curing. Alternatively, it is also preferable to add a monosaccharide derivative or oligosaccharide derivative other than the pentose derivative. The base material for the coating is not particularly limited, but examples of materials that can be used include PET, PP, PE, PS, PC, PMMA, COP (cycloolefin polymer), polyamide, cellulose nanofiber, silicon, and quartz.

[0068] (Metal introduction step) When a molded article is formed using the molding material of the present invention, it is also preferable to provide a step of introducing a metal after molding. By introducing a metal, the strength and conductivity of the molded article can be increased.

[0069] Methods for introducing metals include mixing or coordinating a metal material into the molding material itself, but metals can also be introduced after the molding is completed. Specific examples include metal impregnation methods such as CVD (chemical vapor deposition), sputtering (vacuum deposition), ALD (atomic layer deposition), and SIS (sequential infiltration synthesis). Among these, the metal introduction step is preferably carried out after the molding material is molded. Metal impregnation methods, in which a metal gas is impregnated into the molded body, are particularly preferred because the metal penetrates not only the surface but also the interior of the molded body. In this case, the metal introduction step can be carried out on the entire molded body, or the metal can be introduced by selecting the desired portion of the molded body.

[0070] Examples of metals introduced in the metal introduction step include Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Nb, Mo, Ru, Pd, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Such a process can be carried out, for example, by the method described in Journal of Photopolymer Science and Technology, Volume 29, Number 5 (2016) 653-657. [Example]

[0071] The features of the present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0072] [Sugar preparation] Xylooligosaccharides and xylose were extracted from wood pulp with reference to JP 2012-100546 A.

[0073] [Example 1] (Synthesis of acetyl sugar methacrylate 1) 1 kg of xylose was added to a mixed solution of 12 kg of acetic anhydride and 16 kg of acetic acid and stirred at 30°C for 2 hours. Approximately 5 times the volume of cold water was slowly added while stirring, and the mixture was stirred for 2 hours and then allowed to stand overnight. 60 g of ethylenediamine and 70 g of acetic acid were added to 20 L of THF in a flask, and the temperature was adjusted to 0°C. 1 kg of the precipitated crystals was added and stirred for 4 hours. This was poured into 50 L of cold water and extracted twice with dichloromethane. 1 kg of the resulting extract, 15 L of dichloromethane, and 240 g of triethylamine were placed in a flask and cooled to -30°C. Next, 140 g of methacryloyl chloride was added and stirred for 2 hours. This was poured into 15 L of cold water and extracted twice with dichloromethane. The solvent was concentrated to obtain 810 g of acetyl sugar methacrylate 1. The structure of the obtained acetyl sugar methacrylate 1 is shown in formula (6) below. [ka]

[0074] (Synthesis of acetyl sugar methacrylate polymer 1) 500 mL of tetrahydrofuran and 92 g of a 2.6% by mass solution of lithium chloride in THF (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a flask and cooled to -78°C under an argon atmosphere. 13 g of a 15.4% by mass hexane solution of n-butyllithium (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred for 5 minutes, after which the mixture was dehydrated and degassed. Next, 300 g of acetyl sugar methacrylate 1 was added and stirred for 30 minutes. 10 g of methanol was then added to terminate the reaction, yielding acetyl sugar methacrylate polymer 1. The degree of polymerization of acetyl sugar methacrylate was 350. The weight-average molecular weight of acetyl sugar methacrylate polymer 1 was 34,000. The resulting acetyl sugar methacrylate polymer 1 was used as the molding material.

[0075] [Example 2] (Synthesis of acetyl sugar methacrylate 2) Acetyl sugar methacrylate 2 was synthesized in the same manner as in the synthesis of acetyl sugar methacrylate 1 in Example 1 (synthesis of acetyl sugar methacrylate 1), except that xylooligosaccharide with an average degree of polymerization of 3 was used instead of xylose.

[0076] (Synthesis of acetyl sugar methacrylate polymer 2) A flask was charged with 500 mL of tetrahydrofuran and 92 g of a 2.6% by mass solution of lithium chloride in THF (Tokyo Chemical Industry Co., Ltd.), and cooled to -78°C under an argon atmosphere. 13 g of a 15.4% by mass hexane solution of n-butyllithium (Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was stirred for 5 minutes, followed by dehydration and degassing. Next, acetyl sugar methacrylate 2 (300 g) was added and stirred for 30 minutes. 10 g of methanol was then added to terminate the reaction, yielding acetyl sugar methacrylate polymer 2.

[0077] (Synthesis of polylactic acid) 900 g of L-lactic acid was added to a flask, and after degassing, 4 L of dehydrated toluene (Wako Pure Chemical Industries, Ltd.) and 7 mL of tin(II) 2-ethylhexanoate (Sigma-Aldrich) were added under an argon atmosphere, and the mixture was stirred at 90°C for 24 hours. After the reaction, the mixture was cooled to room temperature, and 5 L of methanol was added to terminate the reaction, yielding polylactic acid.

[0078] (Synthesis of polylactic acid-acetyl sugar methacrylate diblock copolymer) Polylactic acid-acetyl sugar methacrylate two-block copolymer was synthesized with reference to Macromolecules Vol. 36, No. 6, 2003. First, 50 g of acetyl sugar methacrylate polymer 2 and 50 g of polylactic acid were added to 1 L of DMF, and 1 g of NaCNBH3 was added as a reducing agent. The mixture was stirred at 60 °C for 7 days, with 1 g of NaCNBH3 added daily. The mixture was then cooled to room temperature, and 5 L of water was added to precipitate the precipitate. The precipitate was filtered and washed several times with cold water to remove excess acetyl sugar. The filtered solid was then vacuum-dried to obtain polylactic acid-acetyl sugar methacrylate two-block copolymer. The structure of the resulting block copolymer is shown in Formula (7) below. [ka]

[0079] In formula (7), p = 104, q = 156, and r = 1. Note that p, q, and r represent average values ​​in the obtained block copolymer. The weight-average molecular weight of the obtained polylactic acid-acetyl sugar methacrylate two-block copolymer was 32,000. This polylactic acid-acetyl sugar methacrylate two-block copolymer was used as the molding material.

[0080] [Example 3] (Synthesis of acetyl sugars) One kg of xylooligosaccharide (average sugar chain length 8) was added to a mixed solution of 12 kg of acetic anhydride and 15 kg of pyridine, and the mixture was stirred at 30°C for 17 hours. Approximately five times the volume of cold water was slowly added while stirring, and the mixture was stirred for 30 minutes to synthesize acetyl sugar, a xylose acetyl derivative. Four grams of the resulting acetyl sugar, bone dry mass, was mixed with 6 g of PMMA (Sigma-Aldrich, weight-average molecular weight 350,000) to prepare the molding material.

[0081] [Example 4] 10 g of acetyl sugar methacrylate 1 synthesized in Example 1 (Synthesis of acetyl sugar methacrylate 1), 0.3 g of IRGACURE369 (manufactured by Ciba Specialty Chemicals) as a polymerization initiator, 3 g of Light Ester M (manufactured by Kyoeisha Chemical Co., Ltd.), and 2 g of pentaerythritol tetraacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) were mixed, and the resulting polymer was used as the molding material after irradiating with a xenon lamp.

[0082] [Comparative Example 1] Powdered cellulose (manufactured by Sigma-Aldrich) was used as the molding material.

[0083] Comparative Example 2 A molding material was prepared by mixing 4 g of powdered cellulose (manufactured by Sigma-Aldrich Co.) with 6 g of PMMA (manufactured by Sigma-Aldrich Co., weight-average molecular weight: 350,000) with an absolute dry weight of 4 g.

[0084] [Measurement and Evaluation] <Content of pentose derivative-derived units> The content of the pentose derivative-derived unit in the molding material was calculated as follows. Content of pentose derivative-derived units (mass%) = mass of polymer consisting of pentose derivative-derived units / mass of molding material × 100 When the pentose derivative-derived unit forms a copolymer with another structural unit, the content of the pentose derivative-derived unit was calculated as follows. Content of pentose derivative-derived units (mass%) = molecular weight of pentose derivative-derived units × average number of pentose derivative-derived units in copolymer / weight average molecular weight of molding material In the above formula, the molecular weight of the pentose derivative-derived unit, the average content of the pentose derivative-derived unit in the copolymer, and the weight-average molecular weight of the molding material were calculated as follows: 1 The molecular weight of the pentose derivative-derived unit was calculated from the average degree of polymerization of the pentose derivative. The weight average molecular weight of the molding material was measured by gel permeation chromatography (GPC). GPC column: Shode x K-806M / K-802 connected column (Showa Denko K.K.) Column temperature: 40℃ Mobile phase: chloroform Detector: RI The average content of pentose derivative-derived units in the copolymer is 1 Calculated from H-NMR and GPC values. Average number of pentose derivative-derived units in copolymer = (number ratio of pentose derivative-derived units × number average molecular weight of molding material) / {(molecular weight of pentose derivative-derived units × number ratio of pentose derivative-derived units) + (number average molecular weight of other structural units × number ratio of other structural units)}

[0085] <Moldability> (Thermoforming) The molding materials obtained in the Examples and Comparative Examples were thermoformed to confirm their moldability. Specifically, 2 g of the molding materials obtained in the Examples and Comparative Examples were placed in a silicone rubber mold made to form a recess measuring 10 mm x 20 mm x 2 mm. Next, the pressure inside the rubber mold was reduced and the molding material was heated from the outside of the mold with a lamp to 160 to 180°C to melt the molding material. The material was then air-cooled for 1 hour and removed from the mold to obtain a molded product. The moldability was evaluated from the appearance of the molded product using the following evaluation criteria. ◯: No cracks were visually observed in the molded body, and moldability was good. ×: Cracks were visually observed in the molded product, and there was a problem with moldability.

[0086] <Transparency> In the evaluation of moldability, the total light transmittance of the molded article was measured by the method described in JIS K 7105.

[0087] <Conductivity> The molded body produced for the evaluation of formability was placed in an ALD (atomic layer deposition) apparatus (SUNALE R-100B, manufactured by PICUSAN Corporation), and Al(CH3)3 gas was introduced at 95°C, followed by water vapor. This procedure was repeated three times to introduce Al2O3 into the molded body. After the Al2O3 introduction, the molded body was subjected to EDX (energy dispersive X-ray analysis) analysis using an electron microscope JSM7800F (manufactured by JEOL Ltd.) to calculate the ratio of the Al component and evaluate the electrical conductivity according to the following criteria. ◯: The ratio of the Al component is 5 atom % or more, and the compact has electrical conductivity. ×: The ratio of the Al component is less than 5 atom %, and the molded body does not have electrical conductivity.

[0088] [Table 1]

[0089] <Photoformability> In Example 4, the moldability by photoforming was further confirmed. The molding material of Example 4 was applied to a 0.1 μm-thick PET film to a thickness of 200 nm, and a quartz template mold with 100 nm diameter holes was pressed against it, irradiated with a xenon flash lamp, and then removed from the mold. When the surface of the PET film was observed with an SEM, it was confirmed that a pillar structure (molded body) with a diameter of 100 nm, which was the inverse of the hole shape of the quartz template, had been formed. The quartz template transfer structure obtained in Example 4 was free of defects and had optical transparency.

[0090] As described above, the molding materials of the Examples had excellent moldability and transparency. Thus, in the molded articles obtained in the Examples, the occurrence of structural defects such as cracks was suppressed, and strength was expected to be exhibited. Furthermore, since they have optical transparency, they can be used as optical components. Furthermore, since metals can be easily incorporated, they can also be used as conductive or antistatic parts. Additionally, the molded articles produced using the molding materials of the Examples contain components derived from pentose derivatives, and are therefore biodegradable.

Claims

1. A molding material containing a polymer containing units derived from a pentose derivative.

2. The molding material according to claim 1 , wherein the content of the pentose derivative-derived units is 20% by mass or more relative to the total mass of the molding material.

3. The molding material according to claim 1 or 2, wherein the pentose derivative-derived unit is a unit derived from a monomer represented by the following formula (1): 【Chemistry 1】 In formula (1), R １ each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R １ may be the same or different.

4. The molding material according to claim 1 or 2, wherein the pentose derivative-derived unit is a unit derived from a monomer represented by the following formula (2): 【Chemistry 2】 In formula (2), R １ each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group, an acyl group, an aryl group, a trimethylsilyl group, or a phosphoryl group, and a plurality of R １ may be the same or different; R ５ represents a hydrogen atom, an alkyl group, a fluorine atom, a bromine atom, or an iodine atom; Y １ represents a single bond or a linking group.

5. The molding material according to any one of claims 1 to 4, wherein the pentose derivative-derived units are hemicellulose-derived units.

6. The molding material according to any one of claims 1 to 5, further comprising a pentose derivative.

7. The molding material according to any one of claims 1 to 6, further comprising a resin component.

8. The molding material according to any one of claims 1 to 7, which is used for introducing metals.

9. A molded article obtained by molding the molding material according to any one of claims 1 to 8.

10. The molded article according to claim 9, having a total light transmittance of 80% or more.

11. The molded body according to claim 9 or 10, further comprising a metal.

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