Method for producing vinyl monomers

Abstract

The present invention provides a method for producing vinyl monomers using naturally derived raw materials, which allows for the production of vinyl monomers having multiple highly reactive terminal vinyl groups and high heat resistance. [Solution] A method for producing a vinyl monomer is provided, comprising the steps of (1) preparing a starting material containing a dimer acid (1a) of a naturally derived unsaturated fatty acid (1b), and (2) performing a reaction to convert the carboxyl group of the dimer acid (1a) into a vinyl group to obtain a vinyl monomer (2a) having two or more terminal vinyl groups.

Description

[Technical Field]

[0001] This invention relates to a method for producing vinyl monomer. [Background technology]

[0002] Biomass materials, which are derived from biological resources, are attracting attention as environmentally friendly materials. Unlike materials made from finite resources such as petroleum, biomass materials are renewable because they are derived from biological sources, which is one of the major advantages of using biomass materials. Examples of such biomass materials include vinyl monomers. Vinyl monomers are one of the monomers with industrial value as raw materials that can be used in various reactions.

[0003] Regarding manufacturing technologies for such biomass materials, for example, Non-Patent Document 1 discloses a technology for producing vinyl monomer using oleic acid derived from algae. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Journal of Polymer Science Part A: Polymer Chemistry Volume 57, Issue 2 p.85-89 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, the vinyl monomer obtained by the manufacturing technology disclosed in Non-Patent Document 1 has a problem in that it contains only one terminal vinyl group, which limits its application as a crosslinking agent in various reactions. In addition, there is also the problem that the vinyl monomer does not have sufficient heat resistance. Although vinyl monomers are monomers that are desired to be usable in various reactions such as various polymerization reactions, if vinyl monomers with insufficient heat resistance are used in reactions carried out under high temperature conditions, unintended side reactions will occur, and therefore they cannot be used in reactions under high temperature conditions. Thus, vinyl monomers with insufficient heat resistance are limited in the reactions in which they can be used. For these reasons, there is a need to develop a manufacturing method that can produce vinyl monomers that are biomass materials, have multiple highly reactive terminal vinyl groups, and have high heat resistance.

[0006] This invention has been made in view of the above circumstances, and aims to provide a method for producing vinyl monomers using raw materials derived from natural products, which allows for the production of vinyl monomers having multiple highly reactive terminal vinyl groups and high heat resistance. [Means for solving the problem]

[0007] As a result of diligent research to achieve the above-mentioned objectives, the present inventors have found a method for producing a vinyl monomer comprising: (1) a step of preparing a starting material containing a dimer acid (1a) of an unsaturated fatty acid derived from a natural product; and (2) a step of obtaining a vinyl monomer (2a) having two or more terminal vinyl groups by performing a reaction to convert the carboxyl group of the dimer acid (1a) into a vinyl group. Based on this finding, the present invention has been completed. That is, the present invention is as follows.

[0008] <1> A method for producing a vinyl monomer, comprising: (1) preparing a starting material containing a dimer acid (1a) of a naturally derived unsaturated fatty acid (1b); and (2) performing a reaction to convert the carboxyl group of the dimer acid (1a) into a vinyl group to obtain a vinyl monomer (2a) having two or more terminal vinyl groups. <2> The dimer acid (1a) is a dicarboxylic acid. <1> This is a method for producing vinyl monomer as described above. <3> The dimer acid (1a) is a dicarboxylic acid having two terminal carboxyl groups. <2> This is a method for producing vinyl monomer as described above. <4> The aforementioned starting material contains 30 to 100% by mass of the dimer acid (1a). <1> This is a method for producing vinyl monomer as described above. <5> The aforementioned starting material further contains 0 to 70% by mass of trimer acid (1c) of naturally derived unsaturated fatty acids (1b). <1> This is a method for producing vinyl monomer as described above. <6> The unsaturated fatty acid (1b) derived from the natural product has one or more terminal carboxyl groups, and apart from the terminal carboxyl groups, it is composed only of carbon atoms and hydrogen atoms. <1> This is a method for producing vinyl monomer as described above. <7> The process further includes (3) removing impurities other than the vinyl monomer (2a) after step (2), <1> This is a method for producing vinyl monomer as described above. <8> In the vinyl monomer (2a) obtained in step (2) above, the proportion of vinyl monomer (2a-1) having two terminal vinyl groups is 30 to 100% by mass. <1> This is a method for producing vinyl monomer as described above. <9> The vinyl monomer (2a) is composed only of carbon atoms and hydrogen atoms. <1> This is a method for producing vinyl monomer as described above. <10> The method for producing the vinyl monomer according to <1>, wherein the vinyl monomer (2a) has an alkyl group in the side chain. <11> The method for producing the vinyl monomer according to <1>, wherein the Rf value when the vinyl monomer (2a) is developed with hexane as a developing solvent on silica gel thin layer chromatography is 0.5 to 0.9. <12> The method for producing the vinyl monomer according to <1>, wherein the weight average molecular weight of the vinyl monomer (2a) is 500 to 1500. <13> The method for producing the vinyl monomer according to <1>, wherein the 5% weight loss temperature of the vinyl monomer (2a) by thermogravimetric analysis (TGA) is 200 °C or higher.

Advantages of the Invention

[0009] According to the present invention, there is provided a method for producing a vinyl monomer using a natural product-derived raw material, which can obtain a vinyl monomer having a plurality of highly reactive terminal vinyl groups and high heat resistance.

Brief Description of the Drawings

[0010] [Figure 1] 1H-NMR chart of the starting material of Example 1 and the product after column purification. [Figure 2] 13C-NMR chart of the starting material of Example 1 and the product after column purification. [Figure 3] 1H-NMR chart of the product after column purification of Example 2. [Figure 4] 13C-NMR chart of the product after column purification of Example 2. [Figure 5] Chart obtained by overlapping the GPC charts of the vinyl monomers (2a) of Example 1 and Example 2 and the GPC chart of MO synthesized in Comparative Example 1. [Figure 6]This chart shows the TGA graphs of the vinyl monomer (2a) from Example 1 and Example 2 superimposed with the TGA graph of the MO synthesized in Comparative Example 1. [Modes for carrying out the invention]

[0011] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "these embodiments"). These embodiments are illustrative for explaining the present invention and are not intended to limit the present invention to the following. The present invention can be appropriately modified and implemented within the scope of its gist. Furthermore, the configurations and parameters disclosed herein can be any combination unless otherwise specified. Moreover, the upper and lower limits of the values ​​disclosed herein can be any combination unless otherwise specified.

[0012] The method for producing vinyl monomer according to this embodiment is a method for producing vinyl monomer, comprising: (1) preparing a starting material containing a dimer acid (1a) of a naturally derived unsaturated fatty acid (1b); and (2) performing a reaction (hereinafter sometimes referred to as "vinylation reaction") to convert the carboxyl group of the dimer acid (1a) into a vinyl group to obtain a vinyl monomer (2a) having two or more terminal vinyl groups.

[0013] ((1) Process)

[0014] (1) In step (1), a starting material containing dimer acid (1a) of a naturally derived unsaturated fatty acid (1b) is prepared. The starting material used in step (1) contains dimer acid (1a) of a naturally derived unsaturated fatty acid (1b) (hereinafter sometimes abbreviated as "dimer acid (1a)"). In this specification, unless otherwise specified, "dimer acid" means a dimer of a fatty acid (dimeric acid), and "fatty acid" means a monovalent carboxylic acid having one carboxyl group in its hydrocarbon chain.

[0015] Dimer acid (1a) is preferably a dicarboxylic acid having two carboxyl groups. More preferably, dimer acid (1a) is a dicarboxylic acid having two terminal carboxyl groups. Furthermore, it is even more preferable that dimer acid (1a) is composed only of carbon atoms and hydrogen atoms other than the carboxyl groups. By including at least dimer acid (1a) having such a structure, vinyl monomers with high heat resistance can be obtained more efficiently.

[0016] The method for producing dimer acid (1a) is not particularly limited, but for example, it can be synthesized by a dimerization reaction of a naturally derived unsaturated fatty acid (1b). The reaction conditions for the dimerization reaction are not particularly limited, and a suitable method or conditions can be selected as appropriate, taking into consideration the type of dimer acid (1a) which is the target product of the dimerization reaction, the type of unsaturated fatty acid (1b) which is the raw material, and the reaction conditions. An example of a dimerization reaction is a method in which a crystalline clay mineral is used as a catalyst, a lithium salt is added as a co-catalyst, the unsaturated fatty acid is polymerized at a predetermined temperature, and the monomer component is removed by distillation. Examples of crystalline clay minerals include activated clays such as montmorillonite, bentonite, and hectorite, and acid clays. Examples of co-catalysts include lithium halides such as lithium hydroxide, lithium chloride, and lithium carbonate, and lithium organic acids such as lithium acetate, lithium propionate, lithium caproate, and lithium stearate.

[0017] Examples of naturally derived unsaturated fatty acids (1b) include plant-derived unsaturated fatty acids and animal-derived unsaturated fatty acids. Specific examples of plant-derived unsaturated fatty acids include those obtained from coconut oil, palm oil, olive oil, rapeseed oil, rice bran oil, soybean oil, cottonseed oil, castor oil, and algae. Examples of algae used for algae-derived unsaturated fatty acids include Botryococcus, Aurantiochytrium, Pseudocholicitis, Euglena, Chlorella, Dunaliella, Spirulina, Euglena, Nannochloropsis, and Haematococcus. Examples of animal-derived unsaturated fatty acids include those obtained from fats and oils such as beef tallow and pork tallow.

[0018] The number of carbon atoms in the naturally derived unsaturated fatty acid (1b) is not particularly limited, but is preferably 14 to 24. That is, it is preferable that it be an unsaturated fatty acid with 14 to 24 carbon atoms. The lower limit of the number of carbon atoms is more preferably 15 or more, and even more preferably 16 or more. The upper limit of the number of carbon atoms is more preferably 22 or less, and even more preferably 20 or less.

[0019] The number of double bonds in the naturally derived unsaturated fatty acid (1b) is not particularly limited, but is preferably 1 to 6. That is, it is preferable that the unsaturated fatty acid has 1 to 6 double bonds. The upper limit of the number of double bonds may be 5 or less, or 4 or less. The position of the double bond within the unsaturated fatty acid (1b) is not particularly limited, but it is preferably located at a non-terminal position. Examples of such unsaturated fatty acids (1b) include those in which the double bond is included within the molecule of the unsaturated fatty acid (1b) as a double bond in an unsaturated hydrocarbon group, or those that are unsaturated fatty acids as described later.

[0020] Naturally derived unsaturated fatty acids (1b) are preferably those having the number of carbon atoms and double bonds described above. An example of such a preferred combination is a fatty acid having 1 to 6 double bonds and 14 to 24 carbon atoms.

[0021] The molecular structure of the naturally derived unsaturated fatty acid (1b) is not particularly limited, but it is preferable that it has a carboxyl group at its terminal. Furthermore, it is preferable that the naturally derived unsaturated fatty acid (1b) is composed only of carbon atoms and hydrogen atoms other than the carboxyl group. More preferably, the naturally derived unsaturated fatty acid (1b) has one or more terminal carboxyl groups, and is composed only of carbon atoms and hydrogen atoms other than the terminal carboxyl group.

[0022] The type of unsaturated fatty acid (1b) derived from natural products is not particularly limited, but it is preferably at least one selected from the group consisting of monounsaturated fatty acids and polyunsaturated fatty acids.

[0023] Examples of monounsaturated fatty acids include myristoleic acid (14 carbon atoms, 1 double bond), palmitoleic acid (16 carbon atoms, 1 double bond), and oleic acid (18 carbon atoms, 1 double bond).

[0024] Examples of polyunsaturated fatty acids include so-called n-6 ​​polyunsaturated fatty acids and n-3 polyunsaturated fatty acids. Examples of n-6 polyunsaturated fatty acids include linoleic acid (18 carbon atoms, 2 double bonds), γ-linolenic acid (18 carbon atoms, 3 double bonds), and arachidonic acid (20 carbon atoms, 4 double bonds). Examples of n-3 polyunsaturated fatty acids include α-linolenic acid (18 carbon atoms, 3 double bonds), eicosapentaenoic acid (EPA, 20 carbon atoms, 5 double bonds), and docosahexaenoic acid (DHA, 22 carbon atoms, 6 double bonds).

[0025] The starting material can contain dimer acid (1a) and may also contain other components. These other components are not limited to, but may include various components other than dimer acid (1a), solvents, and other additives.

[0026] The starting material may further contain, as a component other than dimer acid (1a), at least one selected from the group consisting of naturally derived unsaturated fatty acids (1b) (hereinafter sometimes abbreviated as "unsaturated fatty acid (1b)", "monomer acid of unsaturated fatty acid (1b)", "monomer acid (1b)", etc.), naturally derived trimer acid of unsaturated fatty acids (1c) (hereinafter sometimes abbreviated as "trimer acid (1c)", "trimer acid of unsaturated fatty acid (1c)", etc.), saturated fatty acids, and polymers of unsaturated fatty acids. For example, the starting material may contain dimer acid (1a) and, as a component other than dimer acid (1a), naturally derived unsaturated fatty acid (1b) and / or trimer acid of said unsaturated fatty acid (1c).

[0027] Examples of naturally derived unsaturated fatty acids (1b) include those that are constituent units of dimer acid (1a) contained in the starting material. For example, unreacted monomeric acid (monomer) that remains when dimer acid (1a) is synthesized by the dimerization reaction of unsaturated fatty acids is an example. Unreacted unsaturated fatty acids (1b) (monomeric acid) can be difficult to separate from dimer acid (1a), but according to the method for producing vinyl monomers of this embodiment, even if the starting material contains unsaturated fatty acids (1b) that are difficult to separate, vinyl monomers with high heat resistance can be efficiently obtained.

[0028] Examples of trimer acids (1c) derived from natural unsaturated fatty acids include trimers of unsaturated fatty acids that are constituent units of dimer acid (1a) contained in the starting material. For example, when synthesizing dimer acid (1a) by a dimerization reaction of unsaturated fatty acids, the unsaturated fatty acid (monomer acid (monomer)) used as a raw material may trimer rather than dimerize. Such trimer acids are examples. Although trimer acid (1c) can be difficult to separate from dimer acid (1a), the vinyl monomer production method according to this embodiment makes it possible to efficiently obtain vinyl monomers with high heat resistance even from starting materials that contain residual trimer acid (1c) that is difficult to separate.

[0029] The starting material preferably contains 30 to 100% by mass of dimer acid (1a). The lower limit of the dimer acid (1a) content in the starting material is more preferably 32% by mass or more, more preferably 33% by mass or more, and even more preferably 34% by mass or more. The upper limit of the dimer acid (1a) content in the starting material may be 99% by mass or less, 98% by mass or less, or 97% by mass or less. By controlling the dimer acid (1a) content within these ranges, vinyl monomers having multiple highly reactive terminal vinyl groups and high heat resistance can be obtained more efficiently.

[0030] If the starting material contains an unsaturated fatty acid (1b), the starting material may contain 0 to 5% by mass of the unsaturated fatty acid (1b). The lower limit of the unsaturated fatty acid (1b) content in the starting material may be 1% by mass or more, or 2% by mass or more. Furthermore, the upper limit of the unsaturated fatty acid (1b) content in the starting material is preferably 4% by mass or less, and more preferably 3% by mass or less. By controlling the unsaturated fatty acid (1b) content within this range, vinyl monomers having multiple highly reactive terminal vinyl groups and high heat resistance can be obtained more efficiently.

[0031] When the starting material contains trimer acid (1c), it is preferable that the starting material contains 0 to 70% by mass of trimer acid (1c) of naturally derived unsaturated fatty acid (1b). The lower limit of the trimer acid (1c) content in the starting material may be 2% by mass or more, 5% by mass or more, or 10% by mass or more. The upper limit of the trimer acid (1c) content in the starting material may be 69% by mass or less, 67% by mass or less, or 65% by mass or less. By controlling the trimer acid (1c) content within these ranges, vinyl monomers having multiple highly reactive terminal vinyl groups and high heat resistance can be obtained more efficiently.

[0032] In the method for producing vinyl monomer according to this embodiment, commercially available dimer acids of unsaturated fatty acids can also be used as starting materials. Some of these commercially available products contain other fatty acid derivatives as components other than dimer acid (1a) (for example, unsaturated fatty acid (1b) (monomer acid) which is a monomer, or polymers such as trimer acid (1c) which is a trimer).

[0033] Commercially available dimer acids include, for example, the "Tsunodyme" (registered trademark) series from Tsukuno Foods Industry Co., Ltd. (e.g., "Tsunodyme 205", "Tsunodyme 216", "Tsunodyme 228", "Tsunodyme 205(W)", "Tsunodyme 216(W)", "Tsunodyme 228(W)", "Tsunodyme 346", "Tsunodyme 395", etc.); the "Pripol" (registered trademark) series from Croda (e.g., "Pripol 1004", "Pripol 1006", "Pripol 1009", "Pripol 1015", "Pripol 1017", "Pripol 1022", etc.); and the "Unydyme" series from Clayton ("Unydyme 14", "Unydyme 14R", "Unydyme T-17", "Unydyme 18", "Unydyme T-18", "Unydyme 22", "Unydyme T-22", "Unydyme Examples include "Unydyme 27", "Unydyme 35", "Unydyme M-9", "Unydyme M-15", "Unydyme M-35", "Unydyme 40", etc.; and the "Haridaimer" (registered trademark) series manufactured by Harima Chemicals, etc. (for example, "Haridaimer 200", "Haridaimer 250", etc.).

[0034] ((2) Process)

[0035] (2) In step (2), a vinyl monomer (2a) having two or more terminal vinyl groups is obtained by performing a vinylization reaction (conversion reaction) to convert the carboxyl group of dimer acid (1a) into a vinyl group. The vinylization reaction performed in step (2) only needs to be able to convert the carboxyl group of dimer acid (1a) into a vinyl group, and appropriate reaction conditions can be selected as appropriate, taking into consideration the type of dimer acid (1a), the type of target vinyl monomer (2a), and the reaction conditions.

[0036] One example of a vinylation reaction that converts a carboxyl group to a vinyl group is the decarbonylation reaction of dimer acid (1a), which converts the carboxyl group of dimer acid (1a) to a vinyl group. The decarbonylation reaction is carried out using a transition metal catalyst, while heating the dimer acid in the presence or absence of a solvent, under atmospheric pressure or reduced pressure, and mixing by stirring or shaking.

[0037] (acid anhydride)

[0038] In vinylization reactions, carboxylic acid anhydrides can be used as additives to allow the reaction to proceed at relatively low temperatures. The type of carboxylic acid anhydride is not particularly limited, but it is preferably at least one selected from the group consisting of, for example, pivalic acid anhydride, acetic acid anhydride, propionic acid anhydride, butyric acid anhydride, isobutyric acid anhydride, valeric acid anhydride, 2-ethylhexanoic acid anhydride, monochloroacetic acid anhydride, dichloroacetic acid anhydride, trichloroacetic acid anhydride, monobromoacetic acid anhydride, dibromoacetic acid anhydride, tribromoacetic acid anhydride, monofluoroacetic acid anhydride, difluoroacetic acid anhydride, trifluoroacetic acid anhydride, glutaric acid anhydride, succinic acid anhydride, and β-bromopropionic acid anhydride. Among these, pivalic acid anhydride and acetic acid anhydride are more preferred.

[0039] The amount of carboxylic acid anhydride used is not particularly limited, but it is preferably used in a ratio of 0.5 to 10 moles per mole of dimer acid. The lower limit is more preferably 1 mole or more, and even more preferably 2 moles or more. The upper limit is more preferably 6 moles or less, and even more preferably 5 moles or less. By using carboxylic acid anhydride within this range, a vinyl monomer with high heat resistance can be obtained more efficiently.

[0040] (catalyst)

[0041] Transition metal catalysts can be used in the vinylation reaction. While not particularly limited, examples of transition metal catalysts include palladium catalysts and rhodium catalysts. Among these, palladium catalysts are preferred from the viewpoint of selectively introducing vinyl groups to the terminals. Any catalyst containing palladium is acceptable as the palladium catalyst; it may be a heterogeneous or homogeneous catalyst.

[0042] Examples of heterogeneous catalysts include catalysts in which palladium is supported on a support such as activated carbon, alumina, silica, or barium sulfate. Specific examples of such heterogeneous catalysts include palladium-carbon, palladium-alumina, palladium-silica, and palladium-barium sulfate.

[0043] Examples of homogeneous catalysts include inorganic palladium salts, organic palladium salts, and palladium complexes. Examples of inorganic palladium salts include palladium chloride and palladium bromide. Examples of organic palladium salts include palladium acetate and palladium benzoate. Examples of palladium complexes include di-μ-chlorobis[(η-allyl)palladium(II)] and dichlorobis(acetonitrile)palladium(II). Among these, palladium chloride and palladium bromide are preferred.

[0044] The ratio of palladium catalyst to 1 mole of dimer acid is not particularly limited, but is preferably 0.1 to 5 mol%. The lower limit is more preferably 0.15 mol% or more, and even more preferably 0.2 mol% or more. The upper limit is more preferably 4 mol% or less, and even more preferably 3 mol% or less. By using the palladium catalyst within this range, heat-resistant vinyl monomers can be obtained more efficiently.

[0045] Examples of rhodium catalysts include rhodium(III) chloride hydrate, tris(triphenylphosphine)rhodium(I) chloride, and bis(triphenylphosphine)rhodium(I) carbonyl chloride. The ratio of rhodium catalyst to 1 mole of dimer acid is not particularly limited, but is preferably 0.1 to 5 moles by mass. The lower limit is more preferably 0.15 moles by mass or more, and even more preferably 0.2 moles by mass or more. The upper limit is more preferably 4 moles by mass or less, and even more preferably 3 moles by mass or less.

[0046] When using a catalyst, a ligand may be used in combination as needed. For example, ligands for palladium catalysts include triphenylphosphine, bis[2-(diphenylphosphino)phenyl] ether, tri(o-tolyl)phosphine, tris(p-chlorophenyl)phosphine, 1,1'-bis(diphenylphosphino)ferrocene, and 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl. Among these, bis[2-(diphenylphosphino)phenyl] ether is preferred.

[0047] (base)

[0048] In vinylization reactions, bases can be used to improve reaction efficiency. Examples of bases, though not particularly limited, include amine compounds, alkali metal compounds, alkaline earth metal compounds, and their salts.

[0049] Examples of amine compounds include tertiary amine compounds and heterocyclic amine compounds.

[0050] Examples of tertiary amine compounds include aliphatic tertiary amines, alicyclic tertiary amines, and aromatic tertiary amines. Examples of aliphatic tertiary amines include trialkylamines such as triethylamine, tripropylamine, tributylamine, trihexylamine, and trioctylamine, and dialkylalkylamines such as diethylmethylamine and dibutylethylamine. Examples of alicyclic tertiary amines include tricycloalkylamines such as tricyclohexylamine, dicycloalkylalkylamines such as dicyclohexylmethylamine, and cycloalkyldialkylamines such as cyclohexyldimethylamine. Examples of aromatic tertiary amines include triarylamines such as triphenylamine and aryldialkylamines such as N,N-dimethylaniline.

[0051] Examples of heterocyclic amine compounds include pyridine, methylpyridine, ethylpyridine, quinoline, isoquinoline, quinoxaline, quinazoline, phthalazine, 1-methylimidazole, and N,N-dimethylaminopyridine.

[0052] Examples of alkali metal compounds include alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal bicarbonates, and alkali metal alkoxides. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Examples of alkali metal carbonates include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate. Examples of alkali metal bicarbonates include lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, and cesium bicarbonate. Examples of alkali metal bicarbonates include lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, and cesium bicarbonate. Examples of alkali metal alkoxides include potassium butoxide, potassium ethoxide, potassium methoxide, sodium butoxide, sodium ethoxide, sodium methoxide, lithium butoxide, lithium ethoxide, and lithium methoxide.

[0053] Examples of alkaline earth metal compounds include alkaline earth metal hydroxides, alkaline earth metal carbonates, alkaline earth metal bicarbonates, and alkaline earth metal bicarbonates. Examples of alkaline earth metal hydroxides include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide. Examples of alkaline earth metal carbonates include beryllium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, and barium carbonate. Examples of alkaline earth metal bicarbonates include beryllium bicarbonate, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate, barium bicarbonate, and rubidium bicarbonate. Examples of alkaline earth metal bicarbonates include beryllium bicarbonate, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate, and barium bicarbonate.

[0054] The bases mentioned above may also be their salts. The explanation of salts overlaps somewhat with what is described above, but examples include halide salts (fluorides, chlorides, bromides, iodides, etc.), ammonium salts, sulfates, nitrates, etc.

[0055] A single base may be used, or two or more bases may be used in combination.

[0056] Among the above, amine compounds are preferred as bases, tertiary amine compounds and heterocyclic amine compounds are more preferred, tertiary amine compounds are even more preferred, and trialkylamine compounds such as triethylamine are preferred.

[0057] The amount of base used is not particularly limited, but it is preferably 0.05 to 1 mole per mole of dimer acid. The lower limit is more preferably 0.1 mole or more, and even more preferably 0.15 mole or more. The upper limit is more preferably 0.8 mole or less, and even more preferably 0.5 mole or less. By using the base within this range, the reaction efficiency can be increased, and a vinyl monomer with high heat resistance can be obtained more efficiently.

[0058] (solvent)

[0059] In the vinylation reaction, a solvent may or may not be used. If a solvent is used, it is preferable that the solvent does not inhibit the desired reaction, such as decarboxylation, and is capable of dissolving the starting materials. The boiling point of the solvent is not particularly limited, but it is preferable that it is higher than the temperature required to carry out the desired reaction, such as decarboxylation. From this viewpoint, the boiling point of the solvent is preferably 100°C or higher, more preferably 150°C or higher, and even more preferably 200°C or higher.

[0060] The type of solvent is not particularly limited, and a suitable solvent can be selected considering the components of the starting materials and the reaction conditions. Examples of solvents include nonpolar solvents, aprotic polar solvents, and protic polar solvents. Examples of nonpolar solvents include hexane, benzene, toluene, 1,4-dioxane, chloroform, and diethyl ether. Examples of aprotic polar solvents include N,N'-dimethylpropylene urea (DMPU), N-methylpyrrolidone (NMP), diethylene glycol dimethyl ether, dichloromethane, tetrahydrofuran (THF), ethyl acetate, acetone, dimethylformamide (DMF), acetonitrile, dimethyl sulfoxide (DMSO), and propylene carbonate. Examples of protic polar solvents include water, methanol, ethanol, isopropanol, and n-butanol. Among these, DMPU, NMP, and diethylene glycol dimethyl ether are preferred.

[0061] The solvent may be used alone or in combination of two or more types.

[0062] The amount of solvent used is not particularly limited, but it is preferable to use 1 to 20 g per 1 g of starting material. The lower limit is more preferably 2 g or more, and even more preferably 5 g or more. The upper limit is more preferably 15 g or less, and even more preferably 10 g or less. When the amount of solvent used is above the lower limit mentioned above, it is preferable from the viewpoint of controlling the viscosity of the reaction solution. When the amount of solvent used is below the upper limit mentioned above, it is preferable from the viewpoint of reaction efficiency.

[0063] (Reaction temperature)

[0064] The reaction temperature for the vinylization reaction is not particularly limited, and a suitable temperature can be selected considering the components of the starting materials and the reaction conditions. The reaction temperature is preferably 50 to 200°C. The lower limit is preferably 70°C or higher, and more preferably 90°C or higher. The upper limit is more preferably 150°C or lower, and even more preferably 130°C or lower. By keeping the reaction temperature within the above range, various side reactions can be suppressed compared to when the reaction is carried out at high temperatures, vinyl groups can be selectively introduced to the terminals, and highly heat-resistant vinyl monomers can be obtained more efficiently.

[0065] (Reaction time)

[0066] The reaction time for the vinylization reaction is not particularly limited, and a suitable time can be selected considering the components of the starting materials and the reaction conditions. The reaction time is preferably 5 to 30 hours. The lower limit is preferably 8 hours or more, and more preferably 12 hours or more. The upper limit is more preferably 24 hours or less, and even more preferably 20 hours or less. By keeping the reaction time within the above range, a vinyl monomer with high heat resistance can be obtained more efficiently.

[0067] (Reaction pressure)

[0068] The reaction pressure for the vinylization reaction is not particularly limited and can be at atmospheric pressure or under reduced pressure. The reaction pressure can be determined by considering the components of the starting materials and the reaction conditions.

[0069] (Other processes)

[0070] The method for producing vinyl monomer according to this embodiment may further include, as necessary, steps (1) and (2) described above. Examples include arbitrary pretreatment and posttreatment. These are described exemplified below.

[0071] (Degassing treatment)

[0072] If the starting material is liquid at room temperature and pressure, or if the vinylization reaction in step (2) is carried out in a solvent, it is preferable to perform a degassing treatment (degassing treatment) of the reaction solution to be used in the vinylization reaction between steps (1) and (2). By performing a degassing treatment, the dissolved oxygen in the reaction solution can be removed or reduced, and a further improvement in the yield of vinyl monomer (2a) can be expected. The method of degassing treatment is not particularly limited, and a suitable degassing treatment method can be appropriately selected considering the type of dimer acid (1a), the type of target vinyl monomer (2a), the reaction scale and reaction conditions, etc. Specific examples of degassing treatment methods include freeze degassing, ultrasonic degassing, membrane degassing, reduced pressure treatment, bubbling treatment using an inert gas, heat treatment, and treatment by adding an oxygen absorber.

[0073] In the case of freeze-degassing treatment, for example, one method is to repeat the operation (freeze cycle) of freezing the reaction solution with liquid nitrogen, reducing the pressure, and then warming the reaction solution to return it to its pre-freezing state (e.g., liquid) one to four times.

[0074] In the case of ultrasonic degassing, for example, an ultrasonic cleaner or the like is used to apply ultrasound to the reaction solution, and the dissolved oxygen is removed as bubbles due to the pressure change in the reaction solution.

[0075] In the case of membrane degassing, for example, one method involves reducing the pressure by passing the reaction solution through a membrane (gas separation membrane) having fine pores that allow gas to pass through but not solvent, thereby removing oxygen contained in the reaction solution.

[0076] In the case of reduced pressure treatment, one method is to remove oxygen contained in the reaction solution by lowering the partial pressure of oxygen in the gas that comes into contact with the solvent.

[0077] In the case of bubbling treatment using an inert gas, one method is to remove oxygen contained in the reaction solution by bubbling an inert gas such as nitrogen or a noble gas (helium gas, argon gas, etc.) into the reaction solution.

[0078] In the case of heat treatment, one method is to remove oxygen contained in the reaction solution by heating the reaction solution. The heating temperature for heat treatment may be, for example, 50°C or higher.

[0079] In cases where an oxygen scavenger is added, methods include adding an oxygen scavenger such as hydrazine or sodium sulfite to the reaction solution to remove oxygen from the reaction solution.

[0080] (Purification process)

[0081] (2) After step (2), it is preferable to perform a purification treatment (purification treatment) on the vinyl monomer (2a) having two or more terminal vinyl groups obtained in step (2). By performing the purification treatment, it is expected that the purity of the vinyl monomer (2a) will be further improved. The means of the purification treatment are not particularly limited, and a suitable purification treatment method can be selected as appropriate, taking into consideration the type of dimer acid (1a), the type of target vinyl monomer (2a), the reaction scale and reaction conditions, etc. Specific examples of purification treatment methods include filtration, concentration, distillation, extraction, crystallization, recrystallization, adsorption, column chromatography (e.g., silica gel column chromatography, etc.). Two or more of these purification treatment methods may be used in combination.

[0082] The method for producing vinyl monomer according to this embodiment preferably further includes a step of removing impurities other than vinyl monomer (2a) after step (2). As a preferred example of the purification process, for example, the method for producing vinyl monomer according to this embodiment preferably further includes a step of removing unreacted starting materials and vinyl monomer (2b) having one terminal carboxyl group. For example, when a dimer acid (1a) having two terminal carboxyl groups is used as the starting material, a by-reaction product may be generated in which only one of the two terminal carboxyl groups is vinylinated by the vinylization reaction in step (2). In that case, the starting materials and vinyl monomer (2b) having one terminal carboxyl group will remain in the system as impurities. Even in such a case, by performing step (3), such by-reaction products (impurities) can be efficiently removed from the reaction product after the vinylization reaction, so that the target vinyl monomer (2a) can be obtained with even higher purity. For example, in conventional manufacturing techniques, if by-reaction products such as vinyl monomer (2b), which are difficult to separate from the target vinyl monomer (2a), are generated in the system, the yield and purity of vinyl monomer (2a) may be reduced. However, according to the manufacturing method of this embodiment, the above-mentioned by-reaction products can be efficiently separated from the target product, making it possible to obtain vinyl monomer (2a) in high yield and / or high purity (however, the effects and benefits of this embodiment are not limited to these).

[0083] The method for producing vinyl monomers according to this embodiment produces vinyl monomers (2a) having two or more terminal vinyl groups, and also has the advantage of a high degree of freedom in selecting the structure of the vinyl monomers (2a) to be produced. For example, vinyl monomers (2a) include vinyl monomers having two or more terminal vinyl groups at the end of a divalent or higher hydrocarbon group. The hydrocarbon group may be, for example, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, but from the viewpoint of biomass and the efficiency of the vinylization reaction, an aliphatic hydrocarbon group is preferred.

[0084] The valency of the various hydrocarbon groups mentioned above can be 2 or higher, but it is preferable that it be 2. In that case, the resulting vinyl monomer (2a) is a vinyl monomer (2a-1; sometimes abbreviated as "DM") having two terminal vinyl groups. Furthermore, the dimer acid (1a) used as the starting material is preferably a dicarboxylic acid having two carboxyl groups. By using such a dicarboxylic acid as the dimer acid (1a), vinyl monomer (2a-1) having two terminal vinyl groups can be produced efficiently.

[0085] Furthermore, the proportion of vinyl monomers having two terminal vinyl groups (2a-1) (2a-1 / 2a) in the vinyl monomer (2a) obtained in step (2) is not particularly limited, but can be set to 30 to 100% by mass as a preferred embodiment of the manufacturing method according to this embodiment. The lower limit of this proportion is more preferably 35% by mass or more. This proportion can be determined in accordance with the method described in the examples later. In conventional manufacturing techniques, if by-reaction products such as vinyl monomer (2b), which are difficult to separate from the target vinyl monomer (2a), are generated in the system, the yield and purity of vinyl monomer (2a) may be reduced. However, according to the manufacturing method according to this embodiment, the above-mentioned by-reaction products can be efficiently separated from the target product. For this reason, the proportion of vinyl monomers having two terminal vinyl groups (2a-1) (2a-1 / 2a) in vinyl monomer (2a) can also be set to the high proportion described above (however, the effects and benefits of this embodiment are not limited to these).

[0086] Furthermore, it is preferable that the vinyl monomer (2a) is a vinyl monomer composed only of carbon atoms and hydrogen atoms. Such a vinyl monomer (2a) is useful as a biomass material and is also useful as a vinyl monomer with high heat resistance. Moreover, the method for producing vinyl monomer according to this embodiment can be expected to have the manufacturing advantage of being simple and efficient. Furthermore, from the viewpoint of efficiently obtaining such vinyl monomer (2a), it is preferable that the raw material dimer acid (1a) is a dimer acid composed only of carbon atoms and hydrogen atoms other than the carboxyl group.

[0087] The vinyl monomer (2a) may have an alkyl group in its side chain. From the viewpoint of efficiently obtaining such vinyl monomer (2a), it is preferable that the raw material dimer acid (1a) is a dimer acid composed only of carbon and hydrogen atoms other than the carboxyl group, and having an alkyl group in its side chain.

[0088] The number of carbon atoms in the vinyl monomer (2a) is not particularly limited, but is preferably 26 to 69. That is, it is preferable that the vinyl monomer has 26 to 69 carbon atoms. The lower limit of the number of carbon atoms is more preferably 28 or more, even more preferably 30 or more, even more preferably 32 or more, and even more preferably 34 or more. The upper limit of the number of carbon atoms is more preferably 60 or less, even more preferably 58 or less, even more preferably 56 or less, and even more preferably 54 or less. According to the method for producing vinyl monomers of this embodiment, vinyl monomers (2a) with such a number of carbon atoms can be produced particularly efficiently.

[0089] The number of double bonds in vinyl monomer (2a), excluding the terminal vinyl group, is not particularly limited, but is preferably 0 to 6. That is, it is preferable that the number of double bonds be 0 to 6. The lower limit of the number of double bonds may be 1 or more, 2 or more, or 3 or more. The upper limit of the number of double bonds may be 5 or less, or 4 or less. Examples of such vinyl monomer (2a) include those in which the double bond is contained within the molecule of vinyl monomer (2a) as a double bond in an unsaturated hydrocarbon group.

[0090] The vinyl monomer (2a) is preferably one having the number of carbon atoms and the number of double bonds described above. An example of such a preferred combination is a vinyl monomer having 0 to 6 double bonds and 26 to 69 carbon atoms.

[0091] Since vinyl monomer (2a) is manufactured from raw materials derived from natural products, it can be suitably used as a biomass material.

[0092] A preferred embodiment of the vinyl monomer (2a) that can be efficiently produced by the vinyl monomer production method according to this embodiment is a vinyl monomer having an Rf value (Relative to front) of 0.5 to 0.9 when developed on silica gel thin-layer chromatography with hexane as the developing solvent. The lower limit of the Rf value is more preferably 0.6 or higher, and even more preferably 0.7 or higher. The upper limit of the Rf value is more preferably 0.85 or lower, and even more preferably 0.8 or lower. The Rf value is a parameter that serves as one indicator of the polarity of the vinyl monomer, and according to the vinyl monomer production method according to this embodiment, vinyl monomers with Rf values ​​in this range can be efficiently produced. The silica gel thin-layer chromatography measurement can be performed in accordance with the method described in the examples below.

[0093] A preferred embodiment of vinyl monomer (2a) that can be efficiently produced by the vinyl monomer production method according to this embodiment is a vinyl monomer having a weight-average molecular weight of 500 to 1500. The lower limit of the weight-average molecular weight is more preferably 550 or higher, even more preferably 600 or higher, and even more preferably 700 or higher. The upper limit of the weight-average molecular weight is more preferably 1300 or lower, and even more preferably 1200 or lower. According to the vinyl monomer production method according to this embodiment, vinyl monomers having a weight-average molecular weight within this range can be efficiently produced. The weight-average molecular weight is the weight-average molecular weight in terms of polystyrene (PSt) calculated by GPC (Gel Permeation Chromatography) measurement using a GPC (Gel Permeation Chromatography) apparatus, and can be calculated in accordance with the method described in the examples below.

[0094] One preferred embodiment of the vinyl monomer (2a) that can be efficiently produced by the vinyl monomer production method according to this embodiment is a vinyl monomer having a molecular weight distribution (Mw / Mn) of 1 to 1.5. The upper limit of the molecular weight distribution is more preferably 1.4 or less, and even more preferably 1.3 or less. The lower limit of the molecular weight distribution may be 1.1 or more, or 1.2 or more. According to the vinyl monomer production method according to this embodiment, vinyl monomers having a molecular weight distribution within this range can be efficiently produced. The molecular weight distribution is the ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) as described above, and can be determined in accordance with the method described in the examples below.

[0095] The method for producing vinyl monomer according to this embodiment makes it possible to obtain vinyl monomer (2a) having high heat resistance. In one preferred embodiment of vinyl monomer (2a), the heat resistance temperature determined by thermogravimetric analysis (TGA) ("5% weight loss temperature of vinyl monomer (2a) determined by thermogravimetric analysis (TGA)") is preferably 200°C or higher, more preferably 220°C or higher, and even more preferably 230°C or higher. The upper limit of this heat resistance temperature is not necessarily limited, but may be 300°C or lower, 295°C or lower, or 290°C or lower. An example of a combination of the upper and lower limits of the heat resistance temperature is a numerical range that is above the lower limit and below the upper limit. For example, 200°C to 300°C, 220°C to 295°C, 230°C to 290°C, etc. are examples. This heat resistance temperature is defined as the temperature at which the weight loss due to heating exceeds 5% in thermogravimetric analysis (TGA) performed in an air atmosphere at a heating rate of 10°C / min. Thermogravimetric analysis can be performed in accordance with the method described in the examples below.

[0096] As described above, the vinyl monomer manufacturing method according to this embodiment allows for the introduction of multiple highly reactive terminal vinyl groups and the production of vinyl monomers with high heat resistance, even though it uses raw materials derived from natural products. In this respect, it is possible to produce vinyl monomers with high heat resistance, which were thought to be difficult to produce efficiently using conventional methods for manufacturing vinyl monomers using raw materials derived from natural products. Furthermore, the vinyl monomer manufacturing method according to this embodiment is expected to alleviate structural constraints on the target vinyl monomer.

[0097] The vinyl monomer obtained by the vinyl monomer production method according to this embodiment is a novel biomass material with the advantage of high heat resistance and is expected to be used in a wide range of fields. Since the vinyl groups introduced into the vinyl monomer are highly reactive with various functional groups, it is also expected to contribute to the development of various functional materials such as adhesives, sealants, and surface coatings. [Examples]

[0098] The present invention will be described in more detail by the following examples and comparative examples, but the present invention is not limited in any way by the following examples.

[0099] <Example 1>

[0100] As a starting material, 7.2 g (12.5 mmol) of a composition containing dimer acid, a naturally derived fatty acid from plant oils (manufactured by Tsukuno Foods Industry Co., Ltd., "Tsunodym® 395", acid value 195 mg KOH / g; a mixture containing 1% by mass of naturally derived unsaturated fatty acid (1b) (monomer acid), 97% by mass of dimer acid (1a), and 2% by mass of trimer acid (1c)) was prepared and placed in a flask (Step (1)). The unsaturated fatty acid (1b) contained in the starting material composition is an unsaturated fatty acid with 18 carbon atoms, the dimer acid (1a) is a dicarboxylic acid with 36 carbon atoms which is a dimer of unsaturated fatty acid (1b), and the trimer acid (1c) is a tricarboxylic acid with 54 carbon atoms which is a trimer of unsaturated fatty acid (1b).

[0101] The number of moles of the starting material, the composition, was calculated using the acid value of the composition (195 mg KOH / g) from the following formula (i). The number of moles of the starting material composition = (Acid value of the composition (mgKOH / g) × Mass of monomeric acid (g)) / (56100 × 1) + (Acid value of the composition (mgKOH / g) × Mass of dimer acid (g)) / (56100 × 2) + (Acid value of the composition (mgKOH / g) × Mass of trimer acid (g)) / (56100 × 3) ... (i) For example, let us explain using Example 1 as an example. The starting material composition for Example 1 ("Tsunodyme 395") contains 1% by mass of monomeric acid (number of carboxyl groups: 1), 97% by mass of dimer acid (number of carboxyl groups: 2), and 2% by mass of trimer acid (number of carboxyl groups: 3), and its acid value is 195 mgKOH / g. When 7.2 g of this composition is used, substituting it into formula (i) yields the following result, which is 12.5 mmol. The number of moles of the starting material composition in Example 1 = (195 × 7.2 × 0.01) / (56100 × 1) + (195 × 7.2 × 0.97) / (56100 × 2) + (195 × 7.2 × 0.02) / (56100 × 3) ≈ 12.5 mmol

[0102] Then, 7.2 g of the aforementioned starting material composition (manufactured by Tsukuno Foods Industry Co., Ltd., "Tsunodyme® 395") was mixed with 50.0 mmol of pivalic anhydride, 0.75 mmol of palladium(II) chloride, 2.25 mmol of bis[2-(diphenylphosphino)phenyl] ether, 2.3 mmol of triethylamine, and 50 mL of N,N'-dimethylpropylene urea (aprotic polar solvent, DMPU) as a solvent. Subsequently, the mixed liquid in the flask was freeze-degassed to remove dissolved oxygen. Furthermore, the mixed liquid in the flask was stirred at 110°C for 20 hours to carry out the reaction that converts the carboxyl group of the dimer acid to a vinyl group (decarbonylation reaction; step (2)).

[0103] After the reaction was complete, 200 mL of ethyl acetate was added to the reaction mixture, and the mixture was extracted and washed with 200 mL of saturated aqueous solution of ammonium chloride and saturated aqueous solution of saline. The organic layer after extraction and washing was filtered using amine-modified silica gel (Fuji Silysia Chemical Co., Ltd., "Chromatrex® NH-DM1020"), and the crude product was obtained by removing ethyl acetate under reduced pressure using an evaporator. The crude product was then purified by silica column chromatography (silica gel carrier: Fujifilm Wako Pure Chemical Industries, Ltd., "Wako Gel 60N", developing solvent: hexane) to obtain 4.1 g of vinyl monomer (2a-1) (hereinafter sometimes abbreviated as "DM") having two terminal vinyl groups (Rf value = 0.78 by silica gel thin-layer chromatography (TLC)).

[0104] (Measurement conditions for Rf value of TLC)

[0105] Silica gel thin-layer chromatography: 20cm x 20cm, manufactured by MERCK, Silica gel 60 F 254 (Catalog number: 1.05735.0001) was cut into 2cm x 5cm pieces and used. Spot size φ: approx. 2mm Developing solvent: Hexane Development temperature: 23±2℃ Deployment distance: approx. 4cm Colorimetric reagent: 0.005 ml / L aqueous solution of potassium permanganate

[0106] ( 1 H-NMR measurement and 13 C-NMR measurement)

[0107] 1 ¹H-NMR measurements were performed by dissolving the sample in CDCl3 solvent and measuring it using an NMR spectrometer (Bruker Biospin Avance 500, measurement frequency 500 MHz, probe: 5 mmφ solution probe, measurement temperature: room temperature (25°C), repetition time: 1 s, number of integrations: 16).

[0108] 13The 13C-NMR measurement was performed by dissolving the sample in CDCl3 solvent and using an NMR apparatus (Bruker's "Biospin Avance 500", measurement frequency 500 MHz, probe: 5 mmφ solution probe, measurement temperature: room temperature (25 °C), repetition time: 1 s, number of integrations 1024 times).

[0109] Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 1, the presence of peaks derived from the terminal vinyl groups that were not present in the starting material was at least confirmed. 1 Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 1, the presence of peaks derived from the terminal vinyl groups that were not present in the starting material was at least confirmed. 1 Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 1 is the 1H-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 1, the presence of peaks derived from the terminal vinyl groups that were not present in the starting material was at least confirmed.

[0110] Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 2, it was at least confirmed that the peak derived from the carboxylic acid that was present in the starting material had completely disappeared. 13 Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 2, it was at least confirmed that the peak derived from the carboxylic acid that was present in the starting material had completely disappeared. 13 Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the product after column purification. That is, Figure 2 is the 13C-NMR chart of the starting material of Example 1 and the vinyl monomer (2a) which is the product. In Figure 2, it was at least confirmed that the peak derived from the carboxylic acid that was present in the starting material had completely disappeared.

[0111] (Molecular weight)

[0112] GPC measurement was carried out under the following conditions to determine the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) in terms of polystyrene (PSt). Apparatus name: HLC-8220GPC (manufactured by Tosoh Corporation) Column: TSKgel GMHXL, TSKgel GMHXL, and TSKgel 2000HXL connected in series Solvent: Tetrahydrofuran Sample concentration: 0.1 wt% Injection volume: 20 μL Measurement temperature: 40 °C Flow rate: 1 mL / min Detector: Differential refractive index detector Calibration curve: Polystyrene (PSt)

[0113] The weight-average molecular weight (Mw) of vinyl monomer (2a) in Example 1 was 800, and the molecular weight distribution (Mw / Mn) was 1.02. Furthermore, the content of vinyl monomer (DM) having two terminal vinyl groups in vinyl monomer (2a) of Example 1, calculated from the area ratio of GPC peaks, was 100% by mass.

[0114] (Heat resistance) Thermogravimetric analysis was performed under the following conditions to determine the heat resistance temperature. Thermogravimetric analyzer: Manufactured by Shimadzu Corporation, model name "DTG-60" Heating rate: 10°C / min Measurement atmosphere: in air

[0115] For the vinyl monomer (2a) of Example 1, the temperature at which the weight loss due to heating exceeded 5% was 268°C. In other words, the heat resistance temperature of the vinyl monomer (2a) of Example 1 was 268°C.

[0116] <Comparative Example 1>

[0117] The vinyl monomer was synthesized under the same conditions as in Example 1, except that 25 mmol of naturally derived oleic acid was used as the starting material instead of the starting material used in Example 1 (a composition containing dimer acid of naturally derived fatty acids). In Comparative Example 1, a vinyl monomer having one vinyl group at the terminal end (hereinafter sometimes abbreviated as "MO") was obtained as the product. The MO in Comparative Example 1 was synthesized in accordance with the method disclosed in Non-Patent Document 1 (Journal of Polymer Science Part A: Polymer Chemistry Volume 57, Issue 2 p.85-89).

[0118] The molecular weight was measured using the same method as in Example 1, and the weight-average molecular weight (Mw) of MO was 340, and the molecular weight distribution (Mw / Mn) was 1.06.

[0119] The heat resistance temperature was measured using the same method as in Example 1, and the heat resistance temperature of MO was found to be 173°C.

[0120] <Example 2>

[0121] Vinyl monomers were synthesized under the same conditions as in Example 1, except that 9.9 mmol of a composition containing dimer acid from vegetable oils, which are naturally derived fatty acids (manufactured by Tsukuno Foods Industry Co., Ltd., "Tsunodym® 346", acid value 182 mgKOH / g; a mixture containing 1% by mass of naturally derived unsaturated fatty acid (1b) (monomer acid), 34% by mass of dimer acid (1a), and 65% by mass of trimer acid (1c)) was used instead of the starting material used in Example 1 (a composition containing dimer acid from naturally derived fatty acids). The yield of the obtained product was 3.4 g, and the Rf value by silica gel thin-layer chromatography (TLC) was 0.77.

[0122] Figure 3 shows the product after column purification in Example 2. 1 This is the H-NMR chart. Specifically, Figure 3 shows the vinyl monomer (2a), which is the product of Example 2. 1 This is an H-NMR chart, and as with Example 1, peaks attributable to terminal vinyl groups can be confirmed in Figure 3.

[0123] Figure 4 shows the product after column purification in Example 2. 13 This is a 1C-NMR chart. Specifically, Figure 4 shows the vinyl monomer (2a), which is the product of Example 2. 13 This is a 1C-NMR chart, and as shown in Figure 4, it can be confirmed that the peaks caused by carboxylic acids have completely disappeared, similar to Example 1.

[0124] The weight-average molecular weight (Mw) of vinyl monomer (2a) in Example 2 was 1020, and the molecular weight distribution (Mw / Mn) was 1.04. Furthermore, calculated from the area ratio of the GPC peaks, the content of vinyl monomer (2a) in Example 2 that has two terminal vinyl groups (DM) was 43% by mass, and the content of vinyl monomer (2a) that has three terminal vinyl groups was 57% by mass.

[0125] For the vinyl monomer (2a) of Example 2, the temperature at which the weight loss due to heating exceeded 5% was 282°C. In other words, the heat resistance temperature of the vinyl monomer (2a) of Example 2 was 282°C.

[0126] Figure 5 shows a chart overlaid with the GPC charts of vinyl monomer (2a) from Example 1 and Example 2 and the GPC chart of MO synthesized in Comparative Example 1. Figure 6 shows a chart overlaid with the TGA graphs of vinyl monomer (2a) from Example 1 and Example 2 and the TGA graph of MO synthesized in Comparative Example 1.

[0127] From the above, it has been confirmed that, according to the manufacturing method of this embodiment, it is possible to obtain a vinyl monomer having multiple highly reactive terminal vinyl groups and high heat resistance, even though it is a method of producing vinyl monomer using raw materials derived from natural products.

Claims

1. (1) A step of preparing a starting material containing dimer acid (1a) of a naturally derived unsaturated fatty acid (1b), (2) A step of obtaining a vinyl monomer (2a) having two or more terminal vinyl groups by carrying out a reaction to convert the carboxyl group of the dimer acid (1a) to a vinyl group, A method for producing vinyl monomers, including the following.

2. The dimer acid (1a) is a dicarboxylic acid. A method for producing a vinyl monomer according to claim 1.

3. The dimer acid (1a) is a dicarboxylic acid having two terminal carboxyl groups. A method for producing a vinyl monomer according to claim 2.

4. The aforementioned starting material contains 30 to 100% by mass of the dimer acid (1a). A method for producing a vinyl monomer according to claim 1.

5. The aforementioned starting material further contains 0 to 70% by mass of trimer acid (1c) of a naturally derived unsaturated fatty acid (1b). A method for producing a vinyl monomer according to claim 1.

6. The unsaturated fatty acid (1b) derived from the natural product has one or more terminal carboxyl groups, and apart from the terminal carboxyl groups, it is composed only of carbon atoms and hydrogen atoms. A method for producing a vinyl monomer according to claim 1.

7. After step (2) above, (3) Further comprising the step of removing impurities other than the vinyl monomer (2a), A method for producing a vinyl monomer according to claim 1.

8. In the vinyl monomer (2a) obtained in step (2) above, the proportion of vinyl monomer (2a-1) having two terminal vinyl groups is 30 to 100% by mass. A method for producing a vinyl monomer according to claim 1.

9. The vinyl monomer (2a) is composed only of carbon atoms and hydrogen atoms. A method for producing a vinyl monomer according to claim 1.

10. The vinyl monomer (2a) has an alkyl group in its side chain. A method for producing a vinyl monomer according to claim 1.

11. The Rf value of the vinyl monomer (2a) when it is developed on a silica gel thin-layer chromatography using hexane as the developing solvent is 0.5 to 0.

9. A method for producing a vinyl monomer according to claim 1.

12. The weight-average molecular weight of the vinyl monomer (2a) is 500 to 1500. A method for producing a vinyl monomer according to claim 1.

13. The 5% weight loss temperature of the vinyl monomer (2a) determined by thermogravimetric analysis (TGA) is 200°C or higher. A method for producing a vinyl monomer according to claim 1.

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