Chloroprene, chloroprene production method, chloroprene-based polymer, vulcanized molded article, adhesive composition, composition for forming dip-molded article, and dip-molded article

Abstract

[Problem] To provide: chloroprene that can be used as the starting material for a synthetic rubber while reducing the environmental impact thereof; a chloroprene production method; and a chloroprene rubber. [Solution] One embodiment of the present invention provides chloroprene that contains biomass-derived carbon atoms.

Description

Chloroprene, method for producing chloroprene, chloroprene polymer, vulcanized molded product, adhesive composition, composition for forming dip molded product, and dip molded product

[0001] The present invention relates to chloroprene, a method for producing chloroprene, a chloroprene-based polymer, a vulcanized molded product, an adhesive composition, a composition for forming a dip-molded product, and a dip-molded product.

[0002] In recent years, demand for bioplastics has been increasing from the perspective of reducing the burden on the environment. As a bioplastic, biopolyethylene has been put on the market and is expected to contribute to reducing carbon dioxide emissions (see Patent Document 1). Currently, the types of bioplastics that can be produced are limited, and there is a demand for the development of compounds that can be used as raw materials for more types of bioplastics. On the other hand, not many bio-derived compounds that can be used as raw materials for synthetic rubber are known.

[0003] JP 2010-511634 A

[0004] In view of the above circumstances, the present invention provides chloroprene that can be used as a raw material for synthetic rubber while reducing the burden on the environment, a method for producing chloroprene, and chloroprene rubber.

[0005] According to one aspect of the present invention, there is provided chloroprene, the chloroprene containing carbon atoms derived from biomass.

[0006] According to this embodiment, it is possible to supply chloroprene that can be used as a raw material for synthetic rubber while reducing the burden on the environment.

[0007] Hereinafter, embodiments of chloroprene, a method for producing chloroprene, and chloroprene rubber will be described. Various features shown in the following embodiments can be combined with each other.

[0008] <Chloroprene and Chloroprene Rubber> The chloroprene (2-chloro-1,3-butadiene) of this embodiment contains carbon atoms derived from biomass. Use of such chloroprene makes it possible to produce synthetic rubber (chloroprene rubber) while reducing the burden on the environment. This can contribute to the realization of a carbon-recycling society. Furthermore, the chloroprene-based polymer of this embodiment is a polymer of the above-mentioned chloroprene. Use of such chloroprene rubber can reduce the burden on the environment and also contribute to the realization of a carbon-recycling society.

[0009] Such chloroprene is defined in ASTM D6866. １４ The biomass degree measured by C isotope measurement is preferably about 0.01% or more and 100% or less, more preferably about 0.1% or more and 80% or less, and more preferably about 1% or more and 60% or less. If the biomass degree is set to the above upper limit or less, chloroprene, which is a raw material for synthetic rubber, can be supplied more cheaply. On the other hand, if the biomass degree is set to the above lower limit or more, it is easier to contribute to the realization of a carbon-recycling society.

[0010] Here, the biomass ratio means the ratio of carbon atoms derived from biomass contained in chloroprene. This biomass ratio is calculated by dividing the radiocarbon ( １４ The biomass content can be determined by measuring the amount of C) contained in chloroprene. The same applies to metal carbide and acetylene. In this specification, the biomass content is determined by the method defined in ASTM D6866. １４ Accelerator Mass Spectrometry (AMS), a type of C isotope measurement method, was used to determine the carbon atoms in chloroprene. １４The carbon content can be determined by measuring the percentage of carbon (percent Modern Carbon: pMC) and calculating the percentage (content) of carbon atoms derived from biomass. The carbon atoms derived from biomass are preferably carbon atoms derived from at least one of charcoal, carbonized pulp, carbonized lignin, carbonized coconut shells, carbonized bagasse, and carbonized sorghum. The advantages of using charcoal as biomass will be described in detail later.

[0011] <Method for Producing Chloroprene> The above-described chloroprene can be produced, for example, by the following method for producing chloroprene. In the method for producing chloroprene of this embodiment, chloroprene is obtained by dimerizing acetylene containing carbon atoms derived from biomass and then reacting it with hydrogen chloride. 1. Synthesis of Acetylene First, acetylene containing carbon atoms derived from biomass is synthesized. This acetylene is preferably obtained through the steps of preparing a carbon source containing biomass and a metal source, heating the carbon source and the metal source in an electric furnace to obtain metal carbide, and reacting the metal carbide with water. According to this method, acetylene can be obtained relatively easily and in high yield. Here, the metal carbide is represented by the chemical formula: MC or MC ２ (M is a metal atom). Each step will be described below.

[0012] <<Preparation Step>> First, a carbon source containing biomass and a metal source are prepared. Examples of biomass include plant-derived biomass and animal-derived biomass. These waste materials may be used alone or in combination. Examples of plant-derived biomass include felled trees, sawmill waste, chips, and wood such as branches; agricultural crops such as corn, sugarcane, wheat, rice, soybeans, rapeseed, and sorghum; agricultural residues such as rice straw, wheat straw, corn stalks and leaves, coconut shells, and bagasse (sugarcane pomace); grasses (herbaceous plants) such as switchgrass and miscanthus; algae such as seaweed and microalgae; pulp; lignocelluloses such as lignin; fruit peels, seeds, and vegetable oils. Examples of animal-derived biomass include livestock (cattle, pigs, chickens, etc.) manure, livestock by-products such as livestock bones or organs, and animal oils.

[0013] The biomass may be used after separation using a specific method. For example, lignocellulosic biomass may be prepared as the biomass, and insoluble matter containing lignin (lignin-containing components) may be separated and recovered from the lignocellulosic biomass using a dilute sulfuric acid method or a concentrated sulfuric acid method. The biomass may be used as a carbon source as is, or the carbonized product obtained after carbonization may be used as a carbon source. The fixed carbon content in the carbon source can be adjusted, for example, by controlling the temperature (carbonization temperature) during carbonization of the biomass. Specifically, the fixed carbon (carbon atoms) content in the carbon source is preferably about 85% by mass or more, more preferably about 90% by mass or more, even more preferably about 95% by mass or more, and may even be 100% by mass. In this case, metal carbide with a reduced impurity content can be obtained at a high yield. The fixed carbon content in the carbon source can be measured according to JIS M 8812:2006.

[0014] Among the above, non-edible biomass, particularly carbonized non-edible biomass, is preferred as the biomass. This is because the use of non-edible biomass eliminates the need to consider competition with food. In particular, the biomass preferably contains at least one of charcoal, pulp carbonized, lignin carbonized (carbonized lignin-containing component), coconut shell carbonized, bagasse carbonized, and sorghum carbonized. It is more preferred that the biomass contains charcoal and / or pulp carbonized, and even more preferred that the biomass contains charcoal. Charcoal is easy to obtain and easy to handle, and therefore has the advantage that when used in combination with coke, they can be easily mixed uniformly. Furthermore, charcoal and pulp carbonized materials do not contain phosphorus compounds, or contain only small amounts of them, thereby sufficiently reducing the content of impurities such as calcium phosphide (metal phosphide) in the resulting metal carbide. Therefore, when acetylene is produced using such metal carbides, the generation of toxic substances such as phosphine derived from the above impurities can be suitably prevented, and therefore safety is high.

[0015] Among charcoal, it is preferable to use hard charcoal. The use of hard charcoal makes it difficult to crush when mixed with coke or in the subsequent heating step, facilitating more stable production of metal carbide. Specific examples of charcoal include white charcoal, black charcoal, sawdust charcoal, and industrial charcoal. These charcoal may be used alone or in combination of two or more types. Specifically, it is preferable that a sample of 35 mm x 35 mm x 10 mm cut from the carbon source has a crushing strength of about 30 kgf or more as measured in accordance with JIS Z 8841:1993.

[0016] Briquettes and molded charcoal produced by firing briquettes can also be suitably used as carbon sources. Such briquettes can be obtained by pulverizing and sieving biomass in a pulverizer to obtain pulverized biomass, mixing the pulverized biomass with a binder in a mixer, and then molding the mixture in a molding machine. The crushing strength of these carbon sources is preferably about 30 kgf or more, more preferably about 35 kgf or more, and even more preferably about 40 kgf or more. The upper limit of the crushing strength of the carbon source is not particularly limited, but is about 60 kgf. The crushing strength of the carbon source can be, for example, about 30 kgf or more and 60 kgf or less. This can suitably prevent collapse of the carbon source during charging or in an electric furnace.

[0017] Such a carbon source preferably has a volatile content of about 5% by mass or less, more preferably about 4% by mass or less, and even more preferably about 3% by mass or less, as measured in accordance with JIS M 8812:2006. The lower limit of the volatile content of the carbon source is not particularly limited, but is about 0.01% by mass. The volatile content of the carbon source can be, for example, about 0.01% by mass or more and about 5% by mass or less. This can suitably prevent the carbon source from burning during storage, etc. Furthermore, the content of phosphorus atoms in the carbon source is preferably about 200 ppm or less, more preferably about 150 ppm or less, about 100 ppm or less, about 60 ppm or less, more preferably about 50 ppm or less, and even more preferably about 40 ppm or less. In this case, even when acetylene is produced using the obtained metal carbide, the generation of toxic substances such as phosphine can be sufficiently prevented, thereby further improving safety.

[0018] However, if a small amount of phosphorus atoms is contained in the carbon source, the odor of phosphorus compounds derived from calcium phosphide (metal phosphide) can be detected, thereby making it possible to detect the leakage of highly flammable acetylene. From this perspective, safety can also be improved. Specifically, the content of phosphorus atoms in the carbon source is preferably about 0.1 ppm or more, more preferably about 0.5 ppm or more, about 1 ppm or more, about 5 ppm or more, about 10 ppm or more, about 15 ppm or more, or about 20 ppm or more, more preferably about 25 ppm or more, and even more preferably about 30 ppm or more. The content of phosphorus atoms in the carbon source can be, for example, about 0.1 ppm or more and about 200 ppm or less.

[0019] The content of sulfur atoms in the carbon source is preferably 0.1% by mass (1000 ppm) or less, more preferably about 800 ppm or less, even more preferably about 600 ppm or less, particularly preferably about 400 ppm or less, and most preferably about 200 ppm or less. In this case, the generation of hydrogen sulfide can be suppressed, thereby improving safety. The generation of sulfur oxides can also be suppressed, thereby reducing corrosion and other problems in metal carbide and bioplastic production equipment. The lower limit of the content of sulfur atoms in the carbon source is not particularly limited, but is about 50 ppm. The content of sulfur atoms in the carbon source can be, for example, about 50 ppm or more and 1000 ppm or less. The contents of phosphorus atoms and sulfur atoms in the carbon source can be measured in accordance with JIS M 8813:2004.

[0020] The ash content in the carbon source is preferably about 13% by mass or less, more preferably about 10% by mass or less, even more preferably about 5% by mass or less, and particularly preferably about 3% by mass or less. In this case, even if the ash is a compound that is reduced in an electric furnace, the amount is small, which can suitably prevent or suppress wasteful consumption of the carbon source and electricity. It can also reduce the number of times the work of periodically removing (cleaning) the reduced ash accumulated at the bottom of the electric furnace is required. Furthermore, it can also improve the purity of calcium hydroxide, a by-product produced when acetylene is generated by reacting metal carbide with water. The lower limit of the ash content in the carbon source is not particularly limited and may be 0% by mass. The ash content in the carbon source can be, for example, about 0% by mass or more and 13% by mass or less. Here, ash refers to the inorganic component residue remaining when the carbon source is completely combusted in air (usually at about 550°C or more and 800°C or less). The ash content in the carbon source can be measured in accordance with JIS M 8812:2006.

[0021] On the other hand, examples of the metal source include alkaline earth metal oxides, alkaline earth metal carbonates, alkaline earth metal hydroxides, alkaline earth metal sulfates, and alkaline earth metal chlorides. These metal sources may be used alone or in combination of two or more. The metal source preferably contains an alkaline earth metal oxide, and more preferably contains calcium oxide. Calcium oxide (CaO) can be, for example, calcium carbonate (CaCO ３ Calcium oxide is an unstable substance obtained by thermal decomposition of calcium carbide (CaO) at approximately 900°C. Calcium oxide is therefore suitable as a metal source due to its high reactivity. Suitable metal carbides include calcium carbide, barium carbide, and magnesium carbide.

[0022] <<Heating Step>> Next, the mixture of the carbon source and the metal source is placed in an electric furnace (carbide electric furnace) and heated. This causes the carbon source and the metal source to react with each other to obtain metal carbide. The heating temperature is not particularly limited, but is preferably about 1700°C or higher and 2200°C or lower, and more preferably about 1900°C or higher and 2100°C or lower. The heating time is also not particularly limited, but when the heating temperature is set as above, it is preferably about 2 minutes to 3 hours, and more preferably about 30 minutes to 1.5 hours. Heating under such heating conditions allows the reaction between the carbon source and the metal source to proceed sufficiently.

[0023] The heating atmosphere is preferably an argon atmosphere. This can prevent unnecessary combustion of carbon monoxide and hydrogen generated during the reaction between the carbon source and the metal source. The amount of carbon source is preferably about 30 parts by mass or more and 400 parts by mass or less, more preferably about 50 parts by mass or more and 300 parts by mass or less, and even more preferably about 70 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the metal source. By carrying out the reaction at such an amount ratio, the yield of metal carbide can be sufficiently increased. The carbon source and the metal source are preferably each in a particulate form. This can increase the contact area between the carbon source and the metal source, thereby improving their reaction efficiency.

[0024] The average particle size of the carbon source is not particularly limited, but is preferably about 8 mm to 50 mm, more preferably about 8 mm to 30 mm, and even more preferably about 8 mm to 10 mm. The average particle size of the metal source is also not particularly limited, but is preferably about 8 mm to 50 mm, more preferably about 8 mm to 30 mm, and even more preferably about 8 mm to 10 mm. In this specification, the average particle size refers to the particle size (D50) at which the cumulative value in the volume-based cumulative particle size distribution obtained by laser diffraction scattering method reaches 50%. The laser diffraction scattering method is measured in accordance with the method described in JIS Z 8825:2013 "Particle size analysis - laser diffraction and scattering method."

[0025] When biomass is used as a carbon source and combined with coke, combustion of the biomass, which has a lower ignition temperature than coke, is initiated first, and the heat from this combustion is expected to promote the combustion of the coke. As a result, the heating temperature can be smoothly adjusted to the above-mentioned range in which the reaction between the carbon source and the metal source proceeds smoothly. This effect is particularly pronounced when charcoal is used as a biomass. Charcoal has a high carbon to hydrogen atom ratio, making it suitable for use in combination with coke. Charcoal is also preferred because it has lower electrical conductivity than coke and is less likely to cause electrical short circuits in an electric furnace. Furthermore, the use of charcoal has the advantage of preventing a significant increase in the production cost of metal carbide, since it does not require significant changes to the electric furnace configuration or the addition of new production equipment.

[0026] Prior to the heating (main heating), the mixture may be preheated at a lower temperature than the heating temperature. Preheating can reduce the consumption of the carbon source during the main heating and increase the yield of metal carbide. Examples of fuel for the preheating include charcoal, which has a low ignition temperature among substances contained in the carbon source, and electric furnace gas (a mixed gas of carbon monoxide and hydrogen) emitted during the main heating. Using charcoal as the fuel for the preheating allows for a smooth transition from preheating to the main heating. Using electric furnace gas as the fuel for the preheating allows for efficient energy utilization while favorably preventing air pollution. Furthermore, by changing the mixing ratio of biomass (charcoal) to coke in the main heating process, the biomass content of the resulting metal carbide can be adjusted. Therefore, the mass balance method can appropriately respond to fluctuations in demand by simply changing the mixing ratio of biomass to coke according to the demand for biomass.

[0027] Furthermore, the gas containing at least carbon monoxide and hydrogen produced in the electric furnace during this heating step may be recovered. That is, the chloroprene production method may further include a step of recovering the gas containing at least carbon monoxide and hydrogen produced in the electric furnace. The recovered carbon monoxide and hydrogen may be used, for example, as an energy source for converting calcium carbonate to calcium oxide or an energy source for converting metal carbide to acetylene, or may be used to convert them into carbon compounds. In the latter case, the chloroprene production method may further include a step of reacting at least carbon monoxide with hydrogen to obtain a carbon compound. This allows for effective use of the gas generated in the metal carbide production step. Examples of such carbon compounds include acrylic acid, olefins (jet fuel), and acetylene black.

[0028] <<Acetylene Production Step>> Next, the metal carbide is reacted with water, thereby producing acetylene. The amount of water added is preferably about 2 to 10 moles, and more preferably about 2.5 to 5 moles, per mole of metal carbide. This allows the reaction between the metal carbide and water to proceed sufficiently. The temperature maintained during the reaction between the metal carbide and water is preferably about 80°C to 200°C, and more preferably about 100°C to 180°C. By maintaining the reaction temperature within this range, evaporation of water can be suitably prevented, allowing the reaction with the metal carbide to proceed sufficiently.

[0029] The metal carbide may be in a block shape, but is preferably in a particulate shape. By using particulate metal carbide, the contact area with water can be increased. As a result, the reaction between the metal carbide and water can proceed just right. In this case, the average particle size of the metal carbide is not particularly limited, but is preferably about 1 mm or more and 150 mm or less, and more preferably about 5 mm or more and 120 mm or less. In this case, the above-mentioned effects can be further improved.

[0030] The water may be, for example, tap water, distilled water, ion-exchanged water, pure water, ultrapure water, RO water, etc. Since the reaction between the metal carbide and water is an exothermic reaction, the generated heat may be recovered and used in the reaction between the carbon source and the metal source as described above. The slaked lime (calcium hydroxide) produced in this reaction can be suitably used, for example, as a cement admixture.

[0031] The metal carbide reacts with pure water to generate acetylene, and the sulfur atom content in the metal carbide is preferably about 100 ppm or less, more preferably about 90 ppm or less, even more preferably about 80 ppm or less, particularly preferably about 50 ppm or less, and may even be 0 ppm. The metal carbide reacts with pure water to generate acetylene, and the phosphorus atom content in the metal carbide is preferably about 1 ppm to 320 ppm, more preferably about 5 ppm to 250 ppm, even more preferably about 10 ppm to 200 ppm, and particularly preferably about 20 ppm to 180 ppm. The metal carbide reacts with pure water to generate acetylene, and the ash content in the metal carbide is preferably about 10% by mass or less, more preferably about 8% by mass or less, even more preferably about 5% by mass or less, particularly preferably about 3% by mass or less, and may be 0% by mass.

[0032] 2. Acetylene Dimerization Next, acetylene is dimerized to produce monovinylacetylene (MVA). The acetylene dimerization reaction (vinylation reaction) is usually carried out by continuously supplying acetylene gas at a predetermined rate to a predetermined amount of Nieuwland catalyst solution (a hydrochloric acid solution of cuprous chloride and ammonium chloride). The reaction temperature is preferably about 65°C or higher and 90°C or lower (specifically, about 72°C). Since the reaction rate at this temperature is 5% or lower, after completion of the reaction, monovinylacetylene is separated from acetylene by utilizing the difference in boiling points between monovinylacetylene and acetylene.

[0033] 3. Chlorination of Monovinylacetylene Next, monovinylacetylene is reacted with hydrogen chloride to obtain chloroprene. The chlorination reaction of monovinylacetylene is usually carried out in a toluene / water two-phase system by mixing a Nieuwland catalyst solution containing hydrogen chloride with a toluene solution containing monovinylacetylene. The reaction temperature is preferably about 30°C to 50°C (specifically, about 40°C). The reaction time is preferably about 30 minutes to 3 hours (specifically, about 1 hour). The reaction pressure is preferably atmospheric pressure.

[0034] <Other Methods for Producing Chloroprene> Chloroprene can also be synthesized by chlorinating butadiene containing carbon atoms derived from biomass, followed by dehydrochlorination. First, butadiene containing carbon atoms derived from biomass is synthesized. This butadiene can be obtained directly by microbial fermentation of biomass, for example, or it can be obtained by producing butanol by microbial fermentation of biomass and then subjecting the butanol to a dehydration reaction. Next, the butadiene is chlorinated by a reaction between butadiene and chlorine to obtain a mixture containing 1,4-dichloro-2-butene and 3,4-dichloro-1-butene.

[0035] The mixture is then heated in the presence of a catalyst to isomerize 1,4-dichloro-2-butene and convert it to 3,4-dichloro-1-butene. Next, 3,4-dichloro-1-butene is dehydrochlorinated in an alkaline solution in the presence of a polymerization inhibitor to obtain chloroprene. The resulting chloroprene is purified, for example, by distillation, to obtain high-purity chloroprene.

[0036] The chloroprene obtained as described above is usually polymerized by radical emulsion polymerization to obtain a chloroprene-based polymer (chloroprene rubber, chloroprene polymer), which is a polymer of chloroprene. For example, rosin acid soap is used as an emulsifier and persulfate is used as a catalyst in this polymerization. The basic properties of the chloroprene rubber can be adjusted by the polymerization temperature and a molecular weight modifier. Furthermore, the vulcanized molded article of this embodiment includes a vulcanized product of a rubber composition, which contains the chloroprene-based polymer. The rubber composition may include a vulcanizing agent, a plasticizer, an antioxidant, a filler, a vulcanization accelerator, a vulcanization rate modifier, a processing aid, a softener, a scorch inhibitor, and the like. Such vulcanized molded articles are preferably transmission belts, conveyor belts, hoses, wipers, dipped products, sealing parts, adhesives, boots, rubber-coated fabrics, rubber rolls, anti-vibration rubber, or sponge products.

[0037] The adhesive composition of this embodiment contains a chloroprene polymer latex, and this chloroprene polymer latex contains the above-mentioned chloroprene polymer. The adhesive composition may also contain a solvent, a metal oxide, a tackifier resin, an antioxidant, etc. The viscosity of the adhesive composition is preferably adjusted to approximately 3500 mPa·S or more and 4500 mPa·S or less. The dip-molded body composition of this embodiment contains a chloroprene polymer latex, and this chloroprene polymer latex contains the above-mentioned chloroprene polymer. The dip-molded body composition may also contain a metal oxide, a heteroaromatic ring compound, an antioxidant, etc. The dip-molded body of this embodiment is a molded product of the above-mentioned dip-molded body composition. The dip-molded body is preferably an industrial or general household glove, a medical glove, a balloon, a catheter, or a boot. Furthermore, the dip-molded body may be provided in any of the following aspects.

[0038] (1) Chloroprene, which contains carbon atoms derived from biomass.

[0039] (2) In the chloroprene described in (1) above, the chloroprene specified in ASTM D6866 １４Chloroprene having a biomass ratio of 0.01% or more and 100% or less as measured by C isotope measurement.

[0040] (3) The chloroprene according to (1) or (2) above, wherein the carbon atom derived from biomass is a carbon atom derived from at least one of charcoal, carbonized pulp, carbonized lignin, carbonized coconut shell, carbonized bagasse, and carbonized sorghum.

[0041] (4) A method for producing chloroprene, comprising dimerizing acetylene containing a carbon atom derived from biomass and then reacting the dimer with hydrogen chloride to obtain the chloroprene described in any one of (1) to (3).

[0042] (5) The method for producing chloroprene according to (4), wherein the acetylene is obtained through a step of preparing a carbon source containing biomass and a metal source, a step of heating the carbon source and the metal source in an electric furnace to obtain a metal carbide, and a step of reacting the metal carbide with water.

[0043] (6) The method for producing chloroprene according to (5) above, wherein the content of phosphorus atoms in the carbon source is 200 ppm or less.

[0044] (7) The method for producing chloroprene according to (6) above, wherein the content of the phosphorus atoms is 0.1 ppm or more.

[0045] (8) The method for producing chloroprene according to any one of (5) to (6) above, wherein the ash content in the carbon source is 13 mass% or less.

[0046] (9) The method for producing chloroprene according to any one of (5) to (8) above, wherein the content of sulfur atoms in the carbon source is 0.1 mass% or less.

[0047] (10) The method for producing chloroprene according to any one of (5) to (9), wherein the carbon source has a volatile content of 5% by mass or less as measured in accordance with JIS M 8812:2006.

[0048] (11) The method for producing chloroprene according to any one of (5) to (10) above, wherein the content of fixed carbon in the carbon source is 85 mass% or more.

[0049] (12) The method for producing chloroprene according to any one of (5) to (11) above, wherein the biomass contains at least one of charcoal, carbonized pulp, carbonized lignin, carbonized coconut shell, carbonized bagasse, and carbonized sorghum.

[0050] (13) In the method for producing chloroprene according to any one of (5) to (12), a sample cut out from the carbon source to a size of 35 mm × 35 mm × 10 mm has a crushing strength of 30 kgf or more as measured in accordance with JIS Z 8841:1993.

[0051] (14) The method for producing chloroprene according to any one of (5) to (13) above, wherein the metal source contains an oxide of an alkaline earth metal.

[0052] (15) The method for producing chloroprene according to any one of (5) to (14) above, further comprising a step of recovering a gas produced in the electric furnace and containing at least carbon monoxide and hydrogen.

[0053] (16) The method for producing chloroprene according to (15) above, further comprising a step of reacting at least the carbon monoxide with the hydrogen to obtain a carbon compound.

[0054] (17) The method for producing chloroprene according to any one of (5) to (16) above, wherein the biomass is pulverized and sized using a pulverizer to obtain pulverized biomass, the pulverized biomass and a binder are mixed using a mixer and then molded using a molding machine to obtain briquettes, and the briquettes are used as the carbon source.

[0055] (18) The method for producing chloroprene according to any one of (5) to (16) above, further comprising the steps of: preparing lignocellulose biomass as the biomass; separating and recovering a lignin-containing component from the lignocellulose biomass; carbonizing the lignin-containing component to obtain a carbonized lignin-containing component; and using the carbonized lignin-containing component as the carbon source.

[0056] (19) A chloroprene-based polymer, which is a polymer of the chloroprene described in any one of (1) to (3) above.

[0057] (20) A vulcanized molded article, comprising a vulcanizate of a rubber composition, the rubber composition containing the chloroprene-based polymer described in (19) above.

[0058] (21) In the vulcanization molded article described in (20) above, the vulcanization molded article is a transmission belt, a conveyor belt, a hose, a wiper, a dipping product, a sealing part, an adhesive, a boot, a rubber-coated fabric, a rubber roll, a vibration-proof rubber, or a sponge product.

[0059] (22) An adhesive composition comprising a chloroprene polymer latex, the chloroprene polymer latex containing the chloroprene polymer described in (19) above.

[0060] (23) A composition for forming a dip-molded body, comprising a chloroprene polymer latex, the chloroprene polymer latex containing the chloroprene polymer described in (19) above.

[0061] (24) A dip-molded body, which is a molded product of the composition for forming a dip-molded body according to (23) above. Of course, the present invention is not limited to this.

[0062] Finally, while various embodiments of the present disclosure have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the claims.

[0063] Chloroprene, a method for producing chloroprene, and chloroprene rubber will be described in more detail below using the following examples and comparative examples, but the invention is not limited to these examples.

[0064] 1. Preparation of raw materials <Carbon source> ・White charcoal: "Kishu Binchotan" manufactured by South Sky Co., Ltd. ・Nara black charcoal: "Black charcoal" manufactured by Yachi Forestry Co., Ltd. ・Sawmill charcoal: "Oga Binchotan" manufactured by Pearl Metal Co., Ltd. ・Coconut shell: "PKS (Palm Kernel Shell)" manufactured by Enelabo Japan Co., Ltd. ・Bagasse: "Dried Bagasse" manufactured by Bagasse Garden Co., Ltd. ・Anthracite: Hong Gay charcoal from Vietnam ・Wood chips: "Natural Season Blend Smoking Chips Value Pack" manufactured by Komeri Co., Ltd. The above white charcoal, Nara black charcoal, sawmill charcoal, and anthracite were each crushed and sieved to an average particle size of approximately 10 mm before use. <Calcium source (metal source)> ・Calcium oxide: Calcium oxide, 99.9%, manufactured by Fujifilm Wako Pure Chemical Corporation <Barium source (metal source)> ・Barium carbonate: Barium carbonate, 99.9%, manufactured by Fujifilm Wako Pure Chemical Corporation

[0065] 2. Production of Metal Carbide, Acetylene, and Chloroprene (Example 1) First, 111 parts by mass of white charcoal as a carbon source and 155 parts by mass of calcium oxide as a calcium source were mixed to obtain a mixture so that the amount of fixed carbon charged was 100 parts by mass. Next, this mixture was placed in a multipurpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd., "Hi-Multi Series") and heated at 2000°C for 1 hour while flowing argon at a rate of 7 L / hr. This produced calcium carbide. The average particle size of the resulting calcium carbide was 10 mm. Subsequently, 2.5 moles of distilled water were added per mole of calcium carbide to produce acetylene. The reaction temperature was maintained at 120°C.

[0066] Next, acetylene gas was continuously supplied at a rate of 15.0 L / min to 2000 mL of a Nieuwland catalyst solution having a copper concentration of 8.6 mol / L, and a dimerization reaction was carried out. The resulting acetylene / monovinylacetylene mixed gas was cooled to -20 °C, and monovinylacetylene was separated and recovered. Next, a solution was prepared by dissolving hydrogen chloride at a ratio of 5.0 mol / L in a Nieuwland catalyst solution having a copper concentration of 8.6 mol / L. Then, 1000 mL of a toluene solution containing 16% by volume of monovinylacetylene was supplied to 2000 mL of this solution, and the reaction was carried out at normal pressure and 40 °C for 1 hour. This resulted in chloroprene.

[0067] Example 2: Calcium carbide, acetylene, and chloroprene were obtained in the same manner as in Example 1, except that 133 parts by mass of sawdust charcoal was used as the carbon source. Example 3: Calcium carbide, acetylene, and chloroprene were obtained in the same manner as in Example 1, except that 111 parts by mass of sawdust charcoal was used as the carbon source.

[0068] Example 4: Except for using 56 parts by mass of white charcoal and 59 parts by mass of anthracite as the carbon source, calcium carbide, acetylene and chloroprene were obtained in the same manner as in Example 1. Example 5: Except for using 11 parts by mass of white charcoal and 106 parts by mass of anthracite as the carbon source, calcium carbide, acetylene and chloroprene were obtained in the same manner as in Example 1.

[0069] Example 6 Calcium carbide, acetylene and chloroprene were obtained in the same manner as in Example 1, except that 1 part by mass of white charcoal and 116 parts by mass of anthracite were used as the carbon source.

[0070] Example 7 Coconut shells were placed in a multipurpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd., "High Multi Series") and heated at 800°C while flowing argon at a rate of 7 L / hr until the fixed carbon reached 90% by mass, yielding coconut shell charcoal. Next, 111 parts by mass of coconut shell charcoal and 195 parts by mass of calcium oxide as a calcium source were mixed to obtain a mixture. This mixture was then placed in a multipurpose high-temperature furnace and heated at 2000°C for 1 hour while flowing argon at a rate of 7 L / hr. This yielded calcium carbide. The resulting calcium carbide was then used to obtain acetylene and chloroprene in the same manner as in Example 1.

[0071] Example 8 Bagasse was placed in a multipurpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd., "High Multi Series") and heated at 800°C while flowing argon at a rate of 7 L / hr until the fixed carbon content reached 90% by mass, thereby obtaining bagasse charcoal. Next, 111 parts by mass of the bagasse charcoal and 195 parts by mass of calcium oxide as a calcium source were mixed to obtain a mixture. Next, this mixture was placed in a multipurpose high-temperature furnace and heated at 2000°C for 1 hour while flowing argon at a rate of 7 L / hr. This resulted in calcium carbide. The obtained calcium carbide was then used to obtain acetylene and chloroprene in the same manner as in Example 1.

[0072] Example 9 The bagasse charcoal obtained in Example 8 was pulverized using a disk mill to obtain bagasse charcoal powder (pulverized bagasse charcoal) with an average particle size of 350 μm. Next, 100 parts by mass of the bagasse charcoal powder and 8 parts by mass of asphalt binder were mixed in a batch mixer until the moisture content reached 7% by mass. This mixture was then molded at a linear pressure of 10 kN / cm using a double-roll molding machine with recesses measuring 34.8 mm x 30 mm x 9.4 mm to obtain bagasse charcoal briquettes. After measuring the crushing strength, 111 parts by mass of the bagasse charcoal briquettes were mixed with 195 parts by mass of calcium oxide as a calcium source to obtain a mixture. This mixture was then placed in a multipurpose high-temperature furnace and heated at 2000 °C for 1 hour while flowing argon at a rate of 7 L / hr. This produced calcium carbide. The resulting calcium carbide was then used to produce acetylene and chloroprene in the same manner as in Example 1.

[0073] (Example 10) Wood chips were hydrolyzed using a concentrated sulfuric acid method, and then the residue was collected by filtration. The resulting residue was washed with hot water at 80°C, followed by acetone, ethyl acetate, and toluene to obtain wood chip-derived lignin. The obtained wood chip-derived lignin was then placed in a multipurpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd., "High Multi Series") and heated at 800°C while flowing argon at a rate of 7 L / hr until the fixed carbon reached 90% by mass, thereby obtaining wood chip-derived lignin carbonized material. Next, 111 parts by mass of the wood chip-derived lignin carbonized material and 195 parts by mass of calcium oxide as a calcium source were mixed to obtain a mixture. Next, this mixture was placed in a multipurpose high-temperature furnace and heated at 2000°C for 1 hour while flowing argon at a rate of 7 L / hr. This resulted in calcium carbide. The obtained calcium carbide was then used to obtain acetylene and chloroprene in the same manner as in Example 1.

[0074] Example 11 The wood chip-derived lignin obtained in Example 10 was heated at 300°C to obtain wood chip-derived lignin hemicarbonized. 100 parts by mass of the wood chip-derived lignin hemicarbonized and 8 parts by mass of asphalt binder were mixed using a batch mixer to obtain wood chip-derived lignin hemicarbonized pellets. The wood chip-derived lignin hemicarbonized pellets were then placed in a multipurpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd., "High Multi Series"), and heated at 800°C under a reduced pressure of 10 Pa at 20 MPa using a press until the fixed carbon reached 90% by mass, obtaining wood chip-derived lignin molded charcoal. Next, 111 parts by mass of the wood chip-derived lignin molded charcoal and 195 parts by mass of calcium oxide as a calcium source were mixed to obtain a mixture. This mixture was then placed in a multipurpose high-temperature furnace and heated at 2000°C for 1 hour while flowing argon at a rate of 7 L / hr. Calcium carbide was thus obtained. Thereafter, acetylene and chloroprene were obtained using the obtained calcium carbide in the same manner as in Example 1.

[0075] Example 12: 111 parts by mass of the wood chip-derived lignin carbonized material obtained in Example 10 was mixed with 411 parts by mass of barium carbonate as a barium source to obtain a mixture. This mixture was then placed in a multipurpose high-temperature furnace and heated at 1550°C for 1 hour while flowing argon at a rate of 7 L / hr. This produced barium carbide. The obtained barium carbide was then used to produce acetylene and chloroprene in the same manner as in Example 1.

[0076] Comparative Example Calcium carbide, acetylene and chloroprene were obtained in the same manner as in Example 1, except that 118 parts by mass of anthracite was used as the carbon source.

[0077] 3. Measurement 3-1. Measurement of biomass degree The biomass carbon source used in each example and comparative example, the metal carbide, acetylene, and chloroprene obtained in each example and comparative example were each measured by accelerator mass spectrometry (AMS) in accordance with ASTM D6866, and the biomass degree was calculated according to the following formula: Biomass degree (%) = Biomass carbon source, metal carbide, acetylene, or chloroprene１４ Mass of C / Mass of total carbon atoms of biomass carbon source, metal carbide, acetylene or chloroprene × 100

[0078] 3-2. Measurement of phosphorus atom and sulfur atom contents in biomass carbon source and anthracite The phosphorus atom and sulfur atom contents (phosphorus content and sulfur content) in the biomass carbon source and anthracite were measured in accordance with JIS M 8813:2004. 3-3. Measurement of carbon atom (fixed carbon) content in biomass carbon source and anthracite The carbon atom content (fixed carbon content) in the biomass carbon source and anthracite was measured in accordance with JIS M 8812:2006.

[0079] 3-4. Measurement of ash content in biomass carbon source The ash content in the biomass carbon source (ash content) was measured in accordance with JIS M 8812:2006. 3-5. Measurement of crushing strength of biomass carbon source The biomass carbon source was molded into a sample measuring 35 mm x 35 mm x 10 mm. The crushing strength of this sample was measured in accordance with JIS Z 8841:1993.

[0080] 3-6. Measurement of phosphorus atom content in metal carbide Acetylene gas was generated from metal carbide in accordance with JIS K 1901:2003. The phosphine content in the acetylene gas (phosphine content) was measured in accordance with JIS K 1901:2003. The phosphorus atom content in the metal carbide (phosphorus content) was calculated from the phosphine content in the acetylene as follows. [wherein Cp is the phosphorus content in the metal carbide, Ap is the phosphine content in the acetylene gas, and Mc is the formula weight of the metal carbide.]

[0081] 3-7. Measurement of sulfur atom content in metal carbide Acetylene gas was generated from metal carbide in accordance with JIS K 1901:2003. The hydrogen sulfide content in the acetylene gas (hydrogen sulfide content) was measured in accordance with JIS K 1901:2003. The sulfur atom content in the metal carbide (sulfur content) was calculated from the hydrogen sulfide content in the acetylene as follows. [wherein Cs is the phosphorus content in the metal carbide, As is the phosphine content in the acetylene gas, and Mc is the formula weight of the metal carbide.]

[0082] 3-8. Measurement of Ash Content in Metal Carbide Calcium hydroxide was obtained by reacting 100 parts by mass of calcium carbide from Examples 1 to 11 and the Comparative Example with 58 parts by mass of pure water. The resulting calcium hydroxide was dried at 150°C until the water content was 0.1% by mass or less. The purity of the calcium hydroxide was measured in accordance with JIS K 8575:2025. Barium hydroxide was obtained by reacting 100 parts by mass of barium carbide from Example 12 with 30 parts by mass of pure water. The resulting barium hydroxide was dried at 150°C until the water content was 0.1% by mass or less. The purity of the barium hydroxide was measured in accordance with JIS K 1417-1992. The ash content in the metal carbide was calculated from the purity of calcium hydroxide or barium hydroxide measured as described above as follows. [where Mc is the formula weight of the metal carbide, Ac is the ash content of the metal carbide, M ＯＨ : Formula weight of metal hydroxide, P ＯＨ : Purity of metal hydroxide.]

[0083] The results are shown in Tables 1 and 2 below.

[0084]

[0085] As shown in Tables 1 and 2, it was confirmed that acetylene and chloroprene reflecting the biomass degree of the metal carbide can be produced. Furthermore, it was confirmed that acetylene and chloroprene having a biomass degree according to the mass balance can be produced. Furthermore, when the chloroprene obtained in each Example and Comparative Example is used to produce chloroprene rubber, it can be produced to the same extent.

Claims

1. Chloroprene containing carbon atoms derived from biomass.

2. The chloroprene according to claim 1, wherein the chloroprene is selected from the group consisting of chloroprene, ... １４ Chloroprene having a biomass ratio of 0.01% or more and 100% or less as measured by C isotope measurement.

3. The chloroprene according to claim 1, wherein the carbon atom derived from biomass is a carbon atom derived from at least one of charcoal, carbonized pulp, carbonized lignin, carbonized coconut shell, carbonized bagasse, and carbonized sorghum.

4. A method for producing chloroprene, comprising dimerizing acetylene containing carbon atoms derived from biomass, and then reacting the dimer with hydrogen chloride to obtain the chloroprene described in any one of claims 1 to 3.

5. A method for producing chloroprene according to claim 4, wherein the acetylene is obtained through the steps of: preparing a carbon source containing biomass and a metal source; heating the carbon source and the metal source in an electric furnace to obtain metal carbide; and reacting the metal carbide with water.

6. The method for producing chloroprene according to claim 5, wherein the content of phosphorus atoms in the carbon source is 200 ppm or less.

7. The method for producing chloroprene according to claim 6, wherein the content of phosphorus atoms is 0.1 ppm or more.

8. The method for producing chloroprene according to claim 5, wherein the ash content in the carbon source is 13 mass % or less.

9. The method for producing chloroprene according to claim 5, wherein the content of sulfur atoms in the carbon source is 0.1 mass % or less.

10. The method for producing chloroprene according to claim 5, wherein the carbon source has a volatile content of 5 mass % or less as measured in accordance with JIS M 8812:2006.

11. The method for producing chloroprene according to claim 5, wherein the content of fixed carbon in the carbon source is 85 mass % or more.

12. The method for producing chloroprene according to claim 5, wherein the biomass contains at least one of charcoal, carbonized pulp, carbonized lignin, carbonized coconut shell, carbonized bagasse, and carbonized sorghum.

13. The method for producing chloroprene according to claim 5, wherein a sample cut out from the carbon source to a size of 35 mm x 35 mm x 10 mm has a crushing strength of 30 kgf or more as measured in accordance with JIS Z 8841:1993.

14. The method for producing chloroprene according to claim 5, wherein the metal source comprises an oxide of an alkaline earth metal.

15. The method for producing chloroprene according to claim 5, further comprising a step of recovering gas produced in the electric furnace and containing at least carbon monoxide and hydrogen.

16. The method for producing chloroprene according to claim 15, further comprising the step of reacting at least the carbon monoxide with the hydrogen to obtain a carbon compound.

17. A method for producing chloroprene according to claim 5, wherein the biomass is pulverized and sized using a pulverizer to obtain pulverized biomass, the pulverized biomass and a binder are mixed using a mixer, and then molded using a molding machine to obtain briquettes, and the briquettes are used as the carbon source.

18. A method for producing chloroprene as described in claim 5, comprising: preparing lignocellulosic biomass as the biomass; separating and recovering lignin-containing components from the lignocellulosic biomass; carbonizing the lignin-containing components to obtain carbonized lignin-containing components; and using the carbonized lignin-containing components as the carbon source.

19. A chloroprene polymer, which is a polymer of the chloroprene described in any one of claims 1 to 3.

20. A vulcanized molded article comprising a vulcanizate of a rubber composition, the rubber composition containing the chloroprene polymer according to claim 19.

21. The vulcanized molded article according to claim 20, which is a transmission belt, a conveyor belt, a hose, a wiper, a dipping product, a sealing part, an adhesive, a boot, a rubber-coated fabric, a rubber roll, a vibration-proof rubber, or a sponge product.

22. An adhesive composition comprising a chloroprene polymer latex, wherein the chloroprene polymer latex contains the chloroprene polymer according to claim 19.

23. A composition for forming a dip-molded body, comprising a chloroprene polymer latex, wherein the chloroprene polymer latex contains the chloroprene polymer according to claim 19.

24. A dip-molded body, which is a molded product of the composition for forming a dip-molded body according to claim 23.