Novel polymer compound

Abstract

To provide a novel industrial material using biomass resources, specifically lignin, which is a non-edible biomass resource.SOLUTION: A polymer compound comprises a lignin skeleton (A), a polyalkylene glycol structure having one end bound to the lignin skeleton (A), and a (meth)acryloyl group-containing group (B).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a novel polymer compound having a lignin skeleton. [Background technology]

[0002] Lignin accounts for 20-30% of plants and wood, and is a non-edible biomass material that can be obtained in large quantities and at relatively low cost.

[0003] Various studies have been conducted to industrially utilize lignin, which is available at low cost and in large quantities. For example, Patent Document 1 discloses a dispersant containing an alkylene oxide adduct of glycol lignin obtained by extracting lignin components from wood using polyalkylene glycol. Patent Document 2 discloses an ultraviolet absorber that contains alkali-treated lignin and absorbs ultraviolet rays of 280 to 400 nm relatively uniformly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-147409 [Patent Document 2] JP 2004-131672 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, although various technologies using lignin have been investigated, the use of lignin as an industrial material is still limited. Due to the progress of global warming, the need for industrial materials derived from biomass resources is increasing, and the development of new industrial materials using lignin is expected to increase.

[0006] In order to solve the above-mentioned problems, an object of the present invention is to provide a novel industrial material using lignin. [Means for solving the problem]

[0007] That is, the present invention relates to the following [1] to [6]. [1] A lignin skeleton (A); A polyalkylene glycol structure having one end bonded to the lignin skeleton (A); A polymer compound having a (meth)acryloyl group-containing group (B). [2] The polymer compound according to [1], wherein the (meth)acryloyl group-containing group (B) is a terminal (meth)acryloyl group-containing polyalkylene glycol group (B1) in which a (meth)acryloyl group is bonded to the other end of the polyalkylene glycol structure. [3] The polymer compound according to [1] or [2], wherein the (meth)acryloyl group-containing group (B) is a (meth)acryloyl group (B2) bonded to the lignin skeleton (A) directly or via a structure other than the polyalkylene glycol structure. [4] The polymer compound according to any one of [1] to [3], which has a terminal hydroxyl group-containing polyalkylene glycol group (C) having a hydroxyl group bonded to the other end of the polyalkylene glycol structure. [5] The (meth)acryloyl group-containing group (B) is a (meth)acryloyl group (B2) bonded to the lignin skeleton (A) directly or via a structure other than the polyalkylene glycol structure; The polymer compound according to any one of [1] to [4], which has a terminal hydroxyl group-containing polyalkylene glycol group (C) having a hydroxyl group bonded to the other end of the polyalkylene glycol structure. [6] The polymer compound according to any one of [1] to [5], having a double bond equivalent of 300 or more and 1,000 or less. [7] The polymer compound according to any one of [1] to [6], having a hydroxyl value of 20 or more and 300 or less. Effect of the Invention

[0008] According to the present invention, a novel industrial material utilizing lignin can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 shows the results of measuring the absorbance of polymer compound α1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0011] In this specification, the terms "(meth)acrylic", "(meth)acrylate", and the like are general terms for "methacrylic", "acrylic", "methacrylate", and "acrylate", respectively.

[0012] In this specification, when a numerical range is indicated using "to", it is intended to include both ends of the range.

[0013] <Polymer Compound of the Present Embodiment> The polymer compound of this embodiment is a novel polymer compound having a lignin skeleton (A), a polyalkylene glycol structure having one end bonded to the lignin skeleton (A), and a (meth)acryloyl group-containing group (B). As described later, in the polymer compound of this embodiment, the lignin skeleton (A) may have a different structure depending on the plant from which the lignin skeleton was obtained. Therefore, the specific chemical structure of the polymer compound of this embodiment cannot be uniquely determined, but may include, for example, a structure such as the following formula (1).

[0014] [ka] [In the formula, each R1 is independently hydrogen or a methyl group, n is an integer of 2 to 4, m is an integer of 2 to 450, and the dashed lines in the formula represent bonds to other atoms]

[0015] (Lignin skeleton (A)) The lignin skeleton (A) (hereinafter, sometimes simply referred to as "skeleton (A)") contained in the polymer compound of this embodiment is a main component of the polymer compound lignin. The lignin skeleton (A) can have a different structure depending on the plant from which the lignin skeleton is obtained. Therefore, in the polymer compound of this embodiment, the structure of the lignin skeleton is not particularly limited as long as it is a structure derived from the lignin of the plant from which the lignin skeleton is obtained. More specifically, the lignin skeleton of the polymer compound of this embodiment has at least a plurality of aromatic rings (A1), one end bonded to at least one of these aromatic rings (A1) via an oxygen atom, and the other end bonded to an aromatic ring different from the aromatic ring bonded via an oxygen atom, and has a linear or branched hydrocarbon structure (A2) (hereinafter, sometimes simply referred to as "hydrocarbon structure (A2)"). The hydrogen atoms in the aromatic ring (A1) and the hydrocarbon structure (A2) may be substituted with various substituents, including the terminal (meth)acryloyl group-containing polyalkylene glycol group (B1), the (meth)acryloyl group (B2), and the terminal hydroxyl group-containing polyalkylene glycol group (C), as described below, as well as hydroxyl groups, -OCH3 groups, and the like. In the polymer compound of this embodiment, these substituents are not included in the lignin skeleton (A). In addition, examples of the aromatic ring (A1) include, but are not limited to, a benzene ring.

[0016] (Polyalkylene glycol structure) The polyalkylene glycol structure (hereinafter, sometimes referred to as "PAG structure") contained in the polymer compound of this embodiment has one end that is bonded to the lignin skeleton (A). The PAG structure is, for example, n H 2n O) m-*2 (*1 and *2 each represent one or the other end bonded to the skeleton (A), and n and m are the same as in formula (1). One end bonded to the skeleton (A) in the PAG structure may be bonded to the hydrocarbon structure of the skeleton (A) directly or via another atomic group. The other end of the PAG structure is bonded to a hydroxyl group or a (meth)acryloyl group, as described below. The other end of the PAG structure may be bonded to a skeleton (A) different from the skeleton (A) to which the one end is bonded, and in this case, the other end bonded to the skeleton (A) in the PAG structure may be bonded to the hydrocarbon structure of the different skeleton (A) directly or via another atomic group.

[0017] The polyalkylene glycol that forms the polyalkylene glycol structure is not particularly limited, and may be a structure in which alkylene glycol units such as ethylene glycol (EO) units and propylene glycol (PO) units are repeated two or more times. In the polymer compound of this embodiment, a plurality of groups containing a PAG structure may be present, and the number of repeats of the PAG structure may differ for each group. Similarly, in each group, the PAG structure may be composed of only one type of repeat unit, or may be composed of two or more types of repeat units.

[0018] ((Meth)acryloyl group-containing group (B)) The (meth)acryloyl group-containing group (B) contained in the polymer compound of this embodiment is a group that is bonded to the lignin skeleton (A) directly or via another atomic group. More specifically, the (meth)acryloyl group-containing group (B) contained in the polymer compound of this embodiment is a (meth)acryloyl group-containing polyalkylene glycol group (B1) described later, and / or a (meth)acryloyl group (B2) bonded to the lignin skeleton (A) directly or via a structure other than a polyalkylene glycol structure. The polymer compound of this embodiment may have only an acryloyl group as the (meth)acryloyl group-containing group (B), may have only a methacryloyl group, or may have both an acryloyl group and a methacryloyl group. In addition, the (meth)acryloyl group-containing group (B) is not particularly limited as long as it is a group that contains a (meth)acryloyl group at the end, and may be the (meth)acryloyl group itself.

[0019] <Types of polymer compounds> The polymer compounds of this embodiment can be broadly divided into two types: polymer compounds α and polymer compounds β. The main difference between polymer compounds α and β is in what groups are essential components. That is, polymer compound α has a terminal (meth)acryloyl group-containing polyalkylene glycol group (B1) as an essential component, whereas polymer compound β has a terminal hydroxyl group-containing polyalkylene glycol group (C) in which a hydroxyl group is bonded to the other end of the polyalkylene glycol structure as an essential component. In polymer compound α, a (meth)acryloyl group (B2) bonded via a structure other than the polyalkylene glycol structure may be present, and a terminal hydroxyl group-containing polyalkylene glycol group (C) may be present. In addition, polymer compound β may have a (meth)acryloyl group-containing polyalkylene glycol group (B1) in which a (meth)acryloyl group is bonded via a structure other than the polyalkylene glycol structure. That is, depending on the embodiment, the polymer compound α and the polymer compound β can be regarded as the same. Hereinafter, both the polymer compounds α and β will be described, but the description of the items common to both will be omitted as appropriate.

[0020] [Polymer compound α] The polymer compound α is a polymer compound having a lignin skeleton (A) and a terminal (meth)acryloyl-containing polyalkylene glycol group (B1) (hereinafter sometimes simply referred to as "group (B1)") having a polyalkylene glycol structure having one end bonded to the lignin skeleton (A) and a (meth)acryloyl group bonded to the other end of the polyalkylene glycol structure.

[0021] (Polyalkylene glycol group containing a terminal (meth)acryloyl group (B1)) The terminal (meth)acryloyl group-containing polyalkylene glycol group (B1) has a polyalkylene glycol structure having one end bonded to the lignin skeleton (A) and a (meth)acryloyl group bonded to the other end of the polyalkylene glycol structure. The end of the group (B1) bonded to the skeleton (A) may be bonded directly to the hydrocarbon structure of the skeleton (A) or via another atomic group. The (meth)acryloyl group bonded to the other end of the polyalkylene glycol structure in the group (B1) may be bonded to the PAG structure directly or via another atomic group, and is typically bonded to the polyalkylene glycol structure via an oxygen atom. When the (meth)acryloyl group is bonded to the polyalkylene glycol structure via an oxygen atom, the end of the group (B1) is a (meth)acryloyloxy group.

[0022] ((Meth)acryloyl group (B2)) The polymer compound α may have a (meth)acryloyl group (B2) (hereinafter, sometimes simply referred to as "group (B2)") bonded to the lignin skeleton (A) directly and / or via a structure other than a polyalkylene glycol structure. When the polymer compound α has the group (B2), the physical properties of the polymer compound α can be adjusted, and for example, when the polymer compound α is used as a curing agent, the curing property of the curing agent can be further improved. When multiple groups (B2) are present in the polymer compound α, the polymer compound α may have only an acryloyl group as each group (B2), may have only a methacryloyl group, or may have both an acryloyl group and a methacryloyl group. In addition, the (meth)acryloyl group in the group (B2) may be bonded to the skeleton (A) directly or via another atomic group (excluding a polyalkylene glycol structure), and is typically bonded to the skeleton (A) via an oxygen atom. When the group (B2) is bonded to the skeleton (A) via an oxygen atom, the terminal of the group (B2) is a (meth)acryloyloxy group.

[0023] [Polymer compound β] The polymer compound β is a polymer compound having a lignin skeleton (A), a terminal hydroxyl group-containing polyalkylene glycol group (C) having a polyalkylene glycol structure having one end bonded to the lignin skeleton (A) and a hydroxyl group bonded to the end of the polyalkylene glycol structure, and a (meth)acryloyl group (B2) bonded to the lignin skeleton via a structure other than the polyalkylene glycol structure. The skeleton (A) and group (B2) are the same as those of the polymer compound α described above, so the terminal hydroxyl group-containing polyalkylene glycol group (C) will be described below.

[0024] (Polyalkylene glycol group containing terminal hydroxyl group (C)) The terminal hydroxyl group-containing polyalkylene glycol group (C) (hereinafter sometimes simply referred to as "group (C)") has a polyalkylene glycol structure having one end bonded to the skeleton (A) and a hydroxyl group bonded to the end of the polyalkylene glycol structure. The one end bonded to the skeleton (A) in the group (C) may be bonded directly to the hydrocarbon structure of the skeleton (A) or via another atomic group. The hydroxyl group bonded to the other end of the polyalkylene glycol structure in the group (C) may be bonded to the PAG structure directly or via another atomic group, and is typically bonded directly to the polyalkylene glycol structure. Other points are the same as those of the polyalkylene glycol structure in the group (B1), so the description will be omitted.

[0025] Other characteristics of polymer compounds Other features of the polymer compound of this embodiment will be described below.

[0026] (double bond equivalent) The double bond equivalent (unit: g / mol) of the polymer compound of this embodiment is preferably 300 or more and 1000 or less. When the double bond equivalent of the polymer compound of this embodiment is within this range, the polymer compound can easily exhibit various physical properties and can be relatively easy to handle. The lower limit of the double bond equivalent of the polymer compound of this embodiment may be 400 or more, 500 or more, or 600 or more. The upper limit of the double bond equivalent of the polymer compound of this embodiment may be 900 or less, 800 or less, or 700 or less. The double bond equivalent of the polymer compound of this embodiment may be a combination of these upper and lower limits.

[0027] The double bond equivalent in this embodiment refers to the number of grams of the target substance per mole of a group having a double bond, and can be calculated by double bond equivalent = (amount of target substance (g) / number of groups having a double bond contained in the polymer compound (mol)). Specifically, the double bond equivalent of the polymer compound in this embodiment refers to a value calculated from the iodine value measured by measuring the iodine value of the polymer compound by the Wiess method based on the method described in "Section 6 Iodine Value" of JIS K0070:1992. The group having a double bond is not particularly limited, but a representative example is an ethylenically unsaturated group, and examples of the ethylenically unsaturated group include an acryloyl group and a methacryloyl group.

[0028] (Hydroxyl value) The hydroxyl value (unit: mgKOH) of the polymer compound of this embodiment is preferably 20 or more and 300 or less. When the hydroxyl value of the polymer compound of this embodiment is within this range, it is possible to obtain a polymer compound that is easy to exhibit various physical properties and is relatively easy to handle. The lower limit of the hydroxyl value of the polymer compound of this embodiment may be 50 or more, 100 or more, or 150 or more. The upper limit of the hydroxyl value of the polymer compound of this embodiment may be 270 or less, 260 or less, 250 or less, or 200 or less. The hydroxyl value of the polymer compound of this embodiment may be a combination of these upper and lower limits.

[0029] The hydroxyl value in this embodiment represents the mass (mg) of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups after acetylation of 1 g of the polymer compound. Specifically, the hydroxyl value of the polymer compound in this embodiment refers to a value measured and calculated by potentiometric titration method specified in JIS K0070:1992.

[0030] (Acid value) The acid value (unit: mgKOH) of the polymer compound of this embodiment is preferably 0 or more and 300 or less. When the acid value of the polymer compound of this embodiment is within this range, the polymer compound can easily exhibit various physical properties and can be relatively easy to handle. The lower limit of the acid value of the polymer compound of this embodiment is preferably closer to 0, but may be 10 or more, 20 or more, or 30 or more. The upper limit of the acid value of the polymer compound of this embodiment may be 270 or less, 250 or less, or 200 or less. The acid value of the polymer compound of this embodiment may be a combination of these upper and lower limits.

[0031] The acid value in this embodiment refers to the mass (mg) of potassium hydroxide required to neutralize the acidic components contained in 1 g of the polymer compound. Specifically, the acid value of the polymer compound in this embodiment refers to a value calculated by measuring the polymer compound by back titration with a 0.1 mol / L hydrochloric acid solution after neutralizing the polymer compound with an excess of 0.1 mol / L potassium hydroxide solution.

[0032] (Weight average molecular weight) The weight average molecular weight (Mw) of the polymer compound of this embodiment is not particularly limited, but from the viewpoint that the polymer compound of this embodiment is easy to exhibit various physical properties and is a polymer compound that is relatively easy to handle, it is preferably 1000 to 50000, more preferably 3000 to 30000, even more preferably 5000 to 15000, and particularly preferably 7500 to 12500. The weight average molecular weight can be determined by gel permeation chromatography (GPC) in accordance with JIS K 7252-1:2016, and is a value converted by standard polystyrene. More specifically, the Mw of the polymer compound of this embodiment can be measured under the following conditions. Equipment: Tosoh Corporation "HLC-8220GPC" (product name) Column: Tosoh Corporation "TSKgel G4000HXL" x 1 "TSKgel G3000HXL" x 1 "TSKgel G2000HXL" x 2 Mobile phase: Tetrahydrofuran Detector: RI

[0033] (number average molecular weight) The number average molecular weight (Mn) of the polymer compound of this embodiment is not particularly limited, but from the viewpoint that the polymer compound of this embodiment is easy to exhibit various physical properties and is a polymer compound that is relatively easy to handle, it is preferably 500 to 25000, more preferably 1500 to 15000, and even more preferably 2500 to 5000. The number average molecular weight can be determined by gel permeation chromatography (GPC) in accordance with JIS K 7252-1:2016, and is a value converted by standard polystyrene. More specifically, the Mn of the polymer compound of this embodiment can be measured under the same conditions as the above Mw.

[0034] (Dispersity (Mw / Mn)) The dispersity (Mw / Mn) of the polymer compound of this embodiment is not particularly limited, but from the viewpoint that the polymer compound of this embodiment is a polymer compound that is easy to exhibit various physical properties and is relatively easy to handle, it is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and even more preferably 1.0 to 3.0. The lower limit of the dispersity may be 1.5 or more, and further 2.0 or more.

[0035] <Method for producing polymer compound according to the present embodiment> A method for producing the polymer compound of this embodiment will be described below. A representative method for producing the polymer compound of this embodiment is to react a polymer compound having a polyalkylene glycol structure added to a lignin skeleton (A) (hereinafter, sometimes referred to as "modified lignin") with a compound having a (meth)acryloyl group. More specifically, a polymer compound having a lignin skeleton (A), a polyalkylene glycol structure, and a (meth)acryloyl group can be produced by adding a compound having a (meth)acryloyl group to various hydroxyl groups of the modified lignin.

[0036] ≪Raw materials≫ The raw materials for producing the polymer compound of this embodiment will be described below. The main raw materials for producing the polymer compound of this embodiment are a polymer compound having a polyalkylene glycol structure added to a lignin skeleton (A) and a compound having a (meth)acryloyl group.

[0037] (Polymer compound in which a polyalkylene glycol structure is added to a lignin skeleton (A)) A polymer compound in which a polyalkylene glycol structure is added to a lignin skeleton (A) is a polymer compound (modified lignin) having at least a lignin skeleton (A) and a terminal hydroxyl group-containing polyalkylene glycol group (C). The modified lignin may further have a hydroxyl group bonded to the skeleton (A). These hydroxyl groups may be present bonded directly to an aromatic ring constituting the skeleton (A) or bonded directly to a hydrocarbon structure constituting the skeleton (A) or bonded directly to a hydrocarbon structure constituting the skeleton (A) or bonded via a carbon atom. Typically, the modified lignin has a hydroxyl group bonded directly to an aromatic ring constituting the skeleton (A) and a hydroxyl group bonded to a hydrocarbon structure constituting the skeleton (A) via a carbon atom. Therefore, the modified lignin is a polymer compound having three types of hydroxyl groups: these two types of hydroxyl groups and the terminal hydroxyl group of the group (C).

[0038] The modified lignin can be produced by reacting a raw lignin having a hydroxyl group directly bonded to an aromatic ring constituting the skeleton (A) and a hydroxyl group bonded to a hydrocarbon structure constituting the skeleton (A) via a carbon atom with a polyalkylene glycol. More specifically, known methods include the production methods described in JP 2017-197517 A and JP 2017-105991 A. In addition, if a commercially available modified lignin is available, the commercially available product may be used, and an example of a commercially available product is the Lignotop series (manufactured by Lignomateria Co., Ltd.).

[0039] The addition rate of polyalkylene glycol in the modified lignin (mass of polyalkylene glycol structure / mass of modified lignin) is preferably 10% or more and 60% or less, more preferably 20% or more and 50% or less, and even more preferably 30% or more and 40% or less, from the viewpoint that the polymer compound of this embodiment is a polymer compound that is easily able to exhibit various physical properties and is relatively easy to handle.

[0040] (Compound having a (meth)acryloyl group) The compound having a (meth)acryloyl group (hereinafter, sometimes referred to as "(meth)acrylic compound") is not particularly limited as long as it can react with the hydroxyl group of the modified lignin to add the (meth)acryloyl group-containing group (B) to the lignin skeleton (A). In addition, depending on the type and amount of the (meth)acrylic compound used, it can be non-selectively (comprehensively) reacted with all types of hydroxyl groups, namely, the hydroxyl group of the group (C), the hydroxyl group bonded to the aromatic ring constituting the skeleton (A), and the hydroxyl group bonded to the hydrocarbon structure constituting the skeleton (A) (hereinafter, sometimes referred to as "three types of hydroxyl groups"), or it can be selectively reacted with any of the three types of hydroxyl groups. In addition, depending on the type and amount of the (meth)acrylic compound used, the amount of hydroxyl groups remaining in the polymer compound can be adjusted. That is, depending on the type and amount of the (meth)acrylic compound used, the above-mentioned polymer compound α and polymer compound β can be selectively produced. In addition, in the modified lignin, due to its structure, it is considered that the hydroxyl groups bonded to the aromatic rings constituting the skeleton (A) tend to react relatively less with (meth)acrylic compounds.

[0041] The (meth)acrylic compound is not particularly limited, and for example, a known compound having one or more (meth)acryloyl groups can be used. Examples of such compounds include (meth)acrylic acid, (meth)acrylic anhydride, (meth)acrylic acid chloride, unsaturated carboxylic acids such as (anhydrous) maleic acid and cinnamic acid, (meth)acrylic acid esters, etc. Examples of (meth)acrylic acid esters include monofunctional (meth)acrylic acid esters having one (meth)acryloyl group, and polyfunctional (meth)acrylic acid esters having two or more (meth)acryloyl groups. Examples of monofunctional (meth)acrylic acid esters include hydroxyl group-containing mono(meth)acrylates such as methyl (meth)acrylate, glycidyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Examples of the polyfunctional (meth)acrylic acid ester include hydroxyl-containing polyfunctional (meth)acrylates such as a condensate of pentaerythritol and acrylic acid (Viscoat #300, manufactured by Osaka Organic Chemical Industry Co., Ltd.). In addition, a (meth)acrylic compound having a polyalkylene glycol structure can also be used, and in this case, the (meth)acrylic compound having a PAG structure is also included in the PAG structure of the polymer compound according to this embodiment. These (meth)acrylic compounds may be used alone or in combination of two or more kinds.

[0042] (others) When producing the polymer compound of the present embodiment, a solvent, a catalyst, a polymerization inhibitor, etc. may be used as necessary from the viewpoint of promoting the reaction, etc. These are not particularly limited, and known ones can be used. Examples of the solvent include organic solvents such as ether solvents such as diethyl ether, tetrahydrofuran (THF), and dioxane, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, acetate solvents such as methyl acetate and ethyl acetate, and amide solvents such as dimethylformamide. Examples of the catalyst include acid catalysts such as p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid, and basic catalysts such as triethylamine, tributylamine, N-methylpiperidine, N-methylmorpholine, 1,4-diazabicyclo[2.2.2]octane, 1,7-diazabicyclo[4.3.0]non-6-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, dimethylaniline, and dimethylaminopyridine. Examples of polymerization inhibitors that can be used include 2,4-dimethyl-6-tert-butylphenol (Topanol A), 2,6-di-tert-butyl-p-cresol (BHT), etc. These solvents, catalysts, polymerization inhibitors, etc. may be used alone or in combination of two or more kinds.

[0043] <Reaction method> The method for producing the polymer compound of this embodiment is not particularly limited, and the polymer compound can be produced by mixing the above-mentioned raw materials in a container and reacting the raw materials by heating, irradiating with light (ultraviolet rays), or the like.

[0044] <Uses of the polymer compound of this embodiment> The application of the polymer compound of the present embodiment is not particularly limited, and the polymer compound of the present embodiment can be used for various applications. In particular, the polymer compound of the present embodiment can be used as a colorant, an ultraviolet absorber, a polymerization inhibitor, a resin raw material, a tackifier, an adhesion imparting agent, an adhesiveness imparting agent, a curing agent, etc.

[0045] When the polymer compound of this embodiment is used as a colorant, the polymer compound can have a large number of (meth)acryloyl groups, and therefore the polymer compound can be firmly bonded to an object such as a resin, resulting in an object that is resistant to discoloration.

[0046] The polymer compound of this embodiment can be adjusted so as to absorb ultraviolet light at about 240 nm, and this effect can be utilized to produce ultraviolet absorbents and polymerization inhibitors, as well as raw materials for these. When the polymer compound of this embodiment is used as an ultraviolet absorber, the polymer compound of this embodiment can have a large number of (meth)acryloyl groups, so that the polymer compound is firmly bonded to the target object and has excellent weather resistance, etc.

[0047] Since the polymer compound of this embodiment can have many (meth)acryloyl groups, when used as a resin raw material, a resin with high strength (hardness) can be obtained. In addition, when the polymer compound of this embodiment is mixed with other resins, etc., and heated, the many (meth)acryloyl groups react with the other resins (particularly other resins having (meth)acryloyl groups) and bond strongly with the other resins, so that a resin (molded product) with high strength can be obtained.

[0048] When the polymer compound of this embodiment is used as a tackifier, adhesion agent, and adhesive agent, the polymer compound can have a large number of (meth)acryloyl groups, and therefore the polymer compound of this embodiment can be firmly bonded to objects, thereby exhibiting good adhesiveness, adhesion, and bonding properties. EXAMPLES

[0049] The present invention will be described below with reference to examples, but the present invention is not limited to these examples in any way.

[0050] <Synthesis of polymer compound α1> In a glass flask equipped with a heating / cooling / stirring device and a reflux condenser, 60.0 g of modified lignin (Lignotop SD4, manufactured by Lignomateria Co., Ltd.), 33.8 g of acrylic anhydride, 0.7 g of p-toluenesulfonic acid monohydrate, 0.02 g of 2,4-dimethyl-6-tert-butylphenol, and 300.0 g of dimethylformamide were placed and reacted at 70 ° C for 27 hours. After cooling to room temperature, the reaction solution was poured into 3135.3 g of a mixed solvent of methanol and water (methanol: water = 4: 1 by mass ratio) to precipitate a solid. The obtained solid was filtered, dissolved in 131.1 g of tetrahydrofuran, and poured into 1808.1 g of a mixed solvent of methanol and water (methanol: water = 4: 1 by mass ratio) to precipitate a solid again. The obtained solid was filtered and dried in a vacuum dryer at 40 ° C for 5 hours, and 37.5 g of the target polymer compound α1 was obtained. The appearance of polymer compound α1 was brown powder. The weight average molecular weight (Mw) of polymer compound α1 was 10,000, the number average molecular weight (Mn) was 4,500, and the dispersity (Mw / Mn) was 2.2. The hydroxyl value of polymer compound α was 255 mg KOH / g, the acid value was 184 mg KOH / g, and the double bond equivalent was 637 g / mol.

[0051] <Measurement of absorbance of polymer compound α1> The polymer compound α1 obtained above was dissolved in tetrahydrofuran (THF) to prepare a THF solution containing 10 ppm of polymer compound α1. This solution was placed in a quartz cell container with an optical path length of 10 mm, and the UV-visible absorption spectrum was measured using a UV-visible spectrophotometer (UV-2450, manufactured by Shimadzu Corporation), and the absorbance at 200 nm to 800 nm was obtained. The results are shown in Figure 1.

[0052] As shown in Figure 1, the polymer compound α1 had an absorption peak at 236 nm. Therefore, the polymer compound α1 can be effectively used as an ultraviolet absorber or as a raw material thereof. [Industrial Applicability]

[0053] The polymer compound of the present invention can be suitably used for various applications as a new industrial material derived from biomass resources.

Claims

1. A lignin skeleton (A); A polyalkylene glycol structure having one end bonded to the lignin skeleton (A); A (meth)acryloyl group-containing group (B); A polymer compound having the formula:

2. The polymer compound according to claim 1, wherein the (meth)acryloyl group-containing group (B) is a terminal (meth)acryloyl group-containing polyalkylene glycol group (B1) in which a (meth)acryloyl group is bonded to the other end of the polyalkylene glycol structure.

3. The (meth)acryloyl group-containing group (B) is a (meth)acryloyl group (B2) bonded to the lignin skeleton (A) directly or via a structure other than the polyalkylene glycol structure. The polymer compound according to claim 1 or 2.

4. 3. The polymer compound according to claim 1, further comprising a terminal hydroxyl group-containing polyalkylene glycol group (C) having a hydroxyl group bonded to the other end of the polyalkylene glycol structure.

5. The (meth)acryloyl group-containing group (B) is a (meth)acryloyl group (B2) bonded to the lignin skeleton (A) directly or via a structure other than the polyalkylene glycol structure; a terminal hydroxyl group-containing polyalkylene glycol group (C) having a hydroxyl group bonded to the other end of the polyalkylene glycol structure; The polymer compound according to claim 1 or 2, having the formula:

6. 3. The polymer compound according to claim 1, having a double bond equivalent of 300 or more and 1,000 or less.

7. The polymer compound according to claim 1 or 2, having a hydroxyl value of 20 or more and 300 or less.

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