Vinyl-chloride-based resin mixture containing calcium carbonate, and production method therefor

Abstract

In an aspect of the present invention, provided is a method for producing a vinyl-chloride-based resin mixture containing calcium carbonate, the method including a mixing or stirring step in which a vinyl-chloride-based resin, a calcium-carbonate-containing composition derived from calcium-containing waste, and a lubricant are mixed to produce a vinyl-chloride-based resin mixture containing calcium carbonate. In another aspect of the present invention, provided is a vinyl-chloride-based resin mixture containing calcium carbonate, said mixture comprising a vinyl-chloride-based resin, a calcium-carbonate-containing composition derived from calcium-containing waste, and a lubricant.

Description

Calcium carbonate-containing vinyl chloride resin mixture, and method for producing the same.

[0001] The present invention relates to a calcium carbonate-containing vinyl chloride resin mixture and a method for producing the same.

[0002] Patent Document 1 discloses "a method for producing recycled cement, comprising the steps of: mixing cement-containing waste with water to produce a first slurry; stirring the first slurry for two hours or more; supplying exhaust gas containing carbon dioxide into the first slurry while stirring the first slurry to fix the carbon dioxide contained in the exhaust gas as calcium carbonate; and obtaining a second slurry produced in the fixation step and containing the calcium carbonate (Claim 1)." Patent Document 2 discloses "a carbon dioxide fixation apparatus characterized by comprising: a hydration means for obtaining a first intermediate by adding water to cement paste sludge, which is concrete sludge from which coarse aggregate and fine aggregate have been removed in the concrete secondary product manufacturing stage, while stirring without solid-liquid separation; a supply means for obtaining a second intermediate by supplying a gas containing carbon dioxide to the first intermediate without solid-liquid separation; and a dewatering means for dewatering the second intermediate to produce a powder containing light calcium carbonate, which is a crystal of calcium carbonate; cement carbonate powder, in which the calcium component of cement particles has been carbonated on the surface of the cement particles; and unreacted cement particles. (Claim 1)" [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Publication No. 2024-130324 [Patent Document 2] Japanese Patent No. 7470262 [General Disclosure]

[0003] In a first embodiment of the present invention, a method for producing a calcium carbonate-containing vinyl chloride resin mixture is provided, comprising a mixing or stirring step of mixing a vinyl chloride resin, a calcium carbonate-containing composition derived from calcium-containing waste, and a lubricant to produce a calcium carbonate-containing vinyl chloride resin mixture.

[0004] In the above, the lubricant may include at least one of the following: a metal soap-based lubricant, a fatty acid-based lubricant, a hydrocarbon-based lubricant, an ester-based lubricant, a fatty acid amide-based lubricant, and a silicone-based lubricant.

[0005] In the above, the lubricant may be included in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0006] In the present invention, we have found that by kneading the stirred compound under different conditions (temperature, rotation speed, and input amount), differences in the decomposition time of the mixture occur.

[0007] In the above, calcium-containing waste may include at least one of the following: concrete waste, limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste.

[0008] In the above, as the calcium carbonate-containing composition derived from calcium-containing waste, a calcium carbonate-containing composition derived from calcium-containing waste that contains 10% by mass or more and 80% by mass or less of calcium carbonate derived from the calcium-containing waste may be used.

[0009] In the above, the calcium carbonate-containing vinyl chloride resin mixture may contain 1 to 250 parts by weight of the calcium carbonate-containing composition per 100 parts by weight of the vinyl chloride resin.

[0010] In a second embodiment of the present invention, a calcium carbonate-containing vinyl chloride resin mixture is provided, comprising a vinyl chloride resin, a calcium carbonate-containing composition derived from calcium-containing waste, and a lubricant.

[0011] In the above, the lubricant may include at least one of the following: a metal soap-based lubricant, a fatty acid-based lubricant, a hydrocarbon-based lubricant, an ester-based lubricant, a fatty acid amide-based lubricant, and a silicone-based lubricant.

[0012] In the above, the lubricant may be included in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0013] In the above, calcium-containing waste may include at least one of the following: concrete waste, limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste.

[0014] In the above, as the calcium carbonate-containing composition derived from calcium-containing waste, a calcium carbonate-containing composition derived from calcium-containing waste that contains 10% by mass or more and 80% by mass or less of calcium carbonate derived from calcium-containing waste may be used.

[0015] In the above, the calcium carbonate-containing vinyl chloride resin mixture may contain 1 to 250 parts by weight of the calcium carbonate-containing composition per 100 parts by weight of the vinyl chloride resin.

[0016] In the above, a molded article may be obtained by molding a calcium carbonate-containing vinyl chloride resin mixture by injection molding, extrusion molding, press molding, or calendering.

[0017] The above summary of the invention does not enumerate all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention.

[0018] An example of the flow of the method for producing the calcium carbonate-containing vinyl chloride resin mixture in this embodiment is shown. A schematic cross-sectional view of an example of the polymerization apparatus 100 is shown. This is a graph showing the temperature and torque measured during stirring of the mixture in production example D1. This is a graph showing the temperature and torque measured during stirring of the mixture in production example D2.

[0019] The present invention will be described below through embodiments, but these embodiments are not intended to limit the scope of the claims. Not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, embodiments will be described with reference to the drawings, but in the drawings, identical or similar parts may be given the same reference numeral to omit redundant descriptions.

[0020] [Calcium Carbonate-Containing Vinyl Chloride Resin Mixture] The calcium carbonate-containing vinyl chloride resin mixture in this embodiment (sometimes simply referred to as "mixture") comprises a vinyl chloride resin, a calcium carbonate-containing composition derived from calcium-containing waste, and a lubricant. The details of the mixture will be described below.

[0021] [Vinyl Chloride Resins] Vinyl chloride resins are polymers obtained by polymerizing monomers (monomers) containing at least vinyl chloride. Vinyl chloride resins may be polyvinyl chloride homopolymers (vinyl chloride monopolymers) or copolymers of polyvinyl chloride and other polymers (copolymers of vinyl chloride monomers and monomers copolymerizable with vinyl chloride). In copolymers of polyvinyl chloride and other polymers, the weight of polyvinyl chloride may be 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, or 95% by weight or more. Vinyl chloride resins may also be chlorinated vinyl chloride copolymers obtained by further chlorinating polyvinyl chloride homopolymers or copolymers.

[0022] In copolymers of polyvinyl chloride and other polymers, monomers copolymerizable with vinyl chloride may be compounds having at least one ethylenic double bond. For example, monomers copolymerizable with vinyl chloride may be at least one of vinyl esters such as vinyl acetate and vinyl propionate, acrylic acid esters such as acrylic acid and ethyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, olefin monomers such as ethylene and propylene, acrylonitrile, styrene, and vinylidene chloride, but are not limited to these.

[0023] The average degree of polymerization of the vinyl chloride resin may be between 500 and 4000. For example, the degree of polymerization of the vinyl chloride resin may be between 600 and 2000, preferably between 700 and 1500, and more preferably between 800 and 1200. If the average degree of polymerization of the vinyl chloride resin is less than 500, the impact strength of the molded product may be low. If the average degree of polymerization of the vinyl chloride resin exceeds 4000, the melt viscosity may increase, making molding difficult. The average degree of polymerization of the vinyl chloride resin may be measured according to JIS K 7367-2:1999.

[0024] [Calcium Carbonate-Containing Composition] The calcium carbonate-containing composition is a composition containing calcium carbonate derived from calcium-containing waste. The calcium carbonate-containing composition may be present in an amount of 1 to 250 parts by weight per 100 parts by weight of vinyl chloride resin. For example, the calcium carbonate-containing composition may be present in an amount of 10 to 200 parts by weight, preferably 20 to 150 parts by weight, and more preferably 25 to 120 parts by weight, per 100 parts by weight of vinyl chloride resin. In this specification, the content or amount used of the calcium carbonate-containing composition may be expressed in terms of the amount of calcium carbonate contained in the calcium carbonate-containing composition. The average primary particle diameter of calcium carbonate may be 0.01 μm or more and 0.3 μm or less, preferably 0.05 μm or more and 0.25 μm or less, and more preferably 0.1 μm or more and 0.25 μm or less. An average primary particle diameter of calcium carbonate of 0.01 μm or more and 0.3 μm or less results in excellent impact strength of the molded product. The average primary particle size of calcium carbonate may be measured according to JIS Z 8901:2006.

[0025] The average particle size D50 of calcium carbonate may be 0.1 μm or more and 50 μm or less, preferably 1 μm or more and 30 μm or less, and more preferably 2 μm or more and 20 μm or less. As an example, the average particle size D50 of calcium carbonate is about 10 μm. Here, "average particle size D50" means the particle size based on 50% of the volume cumulative particle size distribution of calcium carbonate particles. The average particle size D50 can be measured by laser diffraction. For example, after dispersing calcium carbonate particles in a dispersion medium, the particles are introduced into a commercially available laser diffraction particle size distribution analyzer and irradiated with ultrasound at an output of about 40 W at about 40 kHz. Then, a volume cumulative particle size distribution graph is created, and the average particle size D50 of the calcium carbonate particles can be measured by calculating the particle size corresponding to 50% of the volume cumulative amount.

[0026] Calcium carbonate can be obtained by contacting calcium-containing waste with carbon dioxide. Carbon dioxide is known to be present in the atmosphere or exhaust gases. For example, carbon dioxide is known to be present in the exhaust gases of boilers, incinerators, or automobiles. Exhaust gases may contain carbon dioxide at a concentration of 1% to 30% by volume. By contacting calcium-containing waste with carbon dioxide derived from exhaust gases, carbon dioxide can be recovered and effectively utilized as a resource, and the amount of carbon dioxide in the air can be reduced.

[0027] Calcium-containing waste is (industrial) waste containing calcium, such as calcium hydroxide, calcium oxide, and / or calcium carbonate. Calcium-containing waste may include at least one of the following: concrete waste, limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste. Calcium-containing waste may contain 30% by weight or more, preferably 40% by weight or more, and more preferably 50% by weight or more of calcium. Here, the calcium content may refer to the weight of calcium salts. For example, the weight of calcium may refer to the weight of calcium hydroxide or the weight converted to calcium hydroxide.

[0028] Concrete waste may include demolished concrete generated from civil engineering works or the demolition of structures, or surplus concrete generated during the construction of buildings, etc. Concrete waste may be from which aggregate has been removed by specific gravity separation or other means. Concrete waste contains calcium derived from cement.

[0029] For example, concrete waste is concrete sludge water discharged from cleaning concrete mixers at concrete product plants or from cleaning ready-mix concrete transport vehicles. Concrete sludge water may contain 40% to 70% by weight of cement and 30% to 60% by weight of water. The cement may contain 30% to 60% by weight of calcium. The cement may preferably contain 40% or more by weight of calcium, more preferably 50% or more by weight.

[0030] Limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste (these are sometimes collectively referred to simply as "limestone, etc.") are all known to contain a large amount of calcium. Limestone, etc. may contain 30% by weight or more, preferably 40% by weight or more, and more preferably 50% by weight or more of calcium. The calcium in limestone, etc. may contain at least one of calcium hydroxide, calcium oxide, and calcium carbonate.

[0031] The calcium-containing waste may be concrete waste or crushed limestone particles suspended in a solvent such as water. Carbon dioxide is blown into the water or other solvent containing the calcium-containing waste, causing a reaction between the calcium-containing waste and the carbon dioxide. The resulting calcium carbonate-containing composition may be dried to form a solid such as a powder.

[0032] [Lubricant] The lubricant reduces the friction between the vinyl chloride-based resin and the calcium carbonate-containing composition contained in the mixture and / or the friction between these components and the stirrer when the mixture is stirred, and suppresses the generation of heat due to friction. Friction is generated as the particles or melts of the vinyl chloride-based resin and the calcium carbonate-containing composition are mixed together by stirring. Friction also occurs when the particles or melts of the vinyl chloride-based resin and / or the calcium carbonate-containing composition come into contact with the wall surface of the stirrer. As the lubricant suppresses heat generation and the like due to friction, shearing and decomposition of the vinyl chloride-based resin are inhibited, and foaming, discoloration and the like caused by hydrogen chloride gas can be suppressed. The lubricant has low compatibility with the vinyl chloride-based resin, and has a different mechanism of action from plasticizers that are compatible with polyvinyl chloride to impart flexibility. The lubricant may comprise at least one of a metal soap-based lubricant, a fatty acid-based lubricant, a hydrocarbon-based lubricant, an ester-based lubricant, a fatty acid amide-based lubricant, and a silicone-based lubricant. Among the lubricants, at least one of a metal soap-based lubricant, a hydrocarbon-based lubricant, and an ester-based lubricant is further preferred.

[0033] The metal soap-based lubricant (sometimes referred to as "metal-based lubricant") is a fatty acid salt of a metal, and is also called a fatty acid metal salt-based lubricant. The metal may be one that ionizes to become a monovalent, divalent, or trivalent cation. For example, the metal includes at least one of lithium, sodium, potassium, magnesium, calcium, barium, aluminum, and zinc. The fatty acid may be a linear or branched fatty acid having 10 to 20 carbon atoms. For example, the fatty acid includes at least one of decanoic acid, myristic acid, palmitic acid, stearic acid, oleic acid, and lauric acid.

[0034] The fatty acid-based lubricant is a higher fatty acid. The higher fatty acid may be a linear or branched fatty acid having 10 to 20 carbon atoms. For example, the fatty acid includes at least one of decanoic acid, myristic acid, palmitic acid, stearic acid, oleic acid, and lauric acid.

[0035] The hydrocarbon-based lubricant is a linear or branched hydrocarbon. For example, the hydrocarbon is polyethylene wax with a molecular weight of 1000 to 10000, paraffin wax with 20 to 70 carbon atoms, or liquid paraffin. The polyethylene wax suppresses friction between the calcium carbonate-containing vinyl chloride-based resin mixture and the metal surface of a molding machine, and when used in combination with a metal soap-based lubricant, further suppresses the generation of heat due to friction.

[0036] The ester-based lubricant is an ester obtained by reacting an alcohol with a higher fatty acid. The alcohol may be a linear or branched alcohol having 2 to 20 carbon atoms. For example, the alcohol comprises at least one of glycerol, butyl alcohol, pentyl alcohol, hexyl alcohol, octyl alcohol, and stearyl alcohol. The higher fatty acid may be a linear or branched fatty acid having 10 to 20 carbon atoms. For example, the fatty acid comprises at least one of decanoic acid, myristic acid, palmitic acid, stearic acid, oleic acid, and lauric acid. The molecular weight is preferably from 1000 to 10000. The ester-based lubricant may be a polyester wax. The polyester wax suppresses friction between the calcium carbonate-containing vinyl chloride resin mixture and the metal surface of a molding machine, and when used in combination with a metal soap-based lubricant, further suppresses the generation of heat due to friction.

[0037] The fatty acid amide-based lubricant is an amide of a higher fatty acid. The higher fatty acid may be a linear or branched fatty acid having 10 to 20 carbon atoms. For example, the fatty acid comprises at least one of decanoic acid, myristic acid, palmitic acid, stearic acid, oleic acid, and lauric acid.

[0038] The silicone-based lubricant is a silicone resin which is a polymer containing silicon atoms. For example, the silicone resin is dimethylpolysiloxane or methylphenylpolysiloxane. The silicone-based lubricant may be a modified silicone resin. For example, the modified silicone resin is a methylstyryl-modified silicone resin or an alkyl-modified silicone resin.

[0039] In the mixture, the lubricant may be included in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of vinyl chloride resin. For example, in the mixture, the lubricant may be included in an amount of 0.3 parts by weight or more and 10 parts by weight or less, preferably 0.5 parts by weight or more and 10 parts by weight or less, and more preferably 1 part by weight or more and 9 parts by weight or less per 100 parts by weight of vinyl chloride resin. By including 0.1 parts by weight or more and 10 parts by weight or less of lubricant per 100 parts by weight of vinyl chloride resin in the mixture, heat generation due to friction when stirring the mixture is suppressed, and shearing and decomposition of the vinyl chloride resin, generation of hydrogen chloride gas, and discoloration of the molded product are suppressed.

[0040] If the lubricant is present in a mixture in an amount of less than 0.1 parts by weight, there is a risk that heat generation will not be sufficiently suppressed when stirring the mixture. If the lubricant is present in a mixture in an amount exceeding 10 parts by weight, the melting of the vinyl chloride resin particles may not proceed sufficiently, or the lubricant may not dissolve sufficiently in the mixture, potentially resulting in poor moldability (for example, surface quality, which is the appearance quality of the molded product) due to poor dispersion of the lubricant.

[0041] [Content of vinyl chloride resin and calcium carbonate-containing composition in the mixture] In the mixture, the calcium carbonate-containing composition may be included in an amount of 1 part by weight or more and 250 parts by weight or less per 100 parts by weight of vinyl chloride resin. For example, in the mixture, the calcium carbonate-containing composition may be included in an amount of 10 parts by weight or more and 200 parts by weight or less, preferably 20 parts by weight or more and 150 parts by weight or less, and more preferably 25 parts by weight or more and 120 parts by weight or less per 100 parts by weight of vinyl chloride resin.

[0042] If the mixture contains less than 1 part by weight of the calcium carbonate-containing composition per 100 parts by weight of the vinyl chloride resin, the environmental advantages due to the immobilization of exhaust gas and calcium-containing waste are insufficient. If the mixture contains more than 250 parts by weight of the calcium carbonate-containing composition per 100 parts by weight of the vinyl chloride resin, it may become difficult to obtain molded products.

[0043] [Solvent] The mixture may further contain a solvent. Any solvent may be used. For example, the solvent may be water such as deionized water or distilled water, or an organic solvent. For example, the organic solvent may be an alcohol-based solvent. The alcohol-based solvent may consist of one or more alcohols having 2 to 10 carbon atoms, such as isopropyl alcohol, methanol, and ethanol, or an alcohol-based solvent containing one or more of these. As an example, the alcohol-based solvent may contain water and one or more alcohol components selected from isopropyl alcohol, methanol, and ethanol.

[0044] In the mixture, the solvent may be present in an amount of 10% by weight or less. Preferably, the solvent may be present in an amount of 5% by weight or less, more preferably 2% by weight or less, and even more preferably 1% by weight or less.

[0045] [Additives] If necessary, the mixture may further contain one or more additives such as heat stabilizers, ultraviolet absorbers, antioxidants, inorganic particles, and pigments. These additives may be present in amounts of 50 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0046] [Plasticizer] A plasticizer may be used as an additive. In vinyl chloride resins, the plasticizer plays a role in reducing friction between polymers and decreasing viscosity. Plasticizers have high compatibility with vinyl chloride resins, and in this respect their mechanism of action differs from that of lubricants. Epoxy soybean oil or bis(2-ethylhexyl) phthalate (also known as DEHP) may be suitably used as the plasticizer. The amount of plasticizer is preferably varied depending on whether it is for hard or soft applications, but for example, the amount of plasticizer per 100 parts by weight of vinyl chloride resin is 250 parts by weight or less, preferably 100 parts by weight or less, more preferably 80 parts by weight or less, and most preferably 50 parts by weight or less.

[0047] [Manufacturing Method] Figure 1 shows an example of a flow chart for manufacturing the calcium carbonate-containing vinyl chloride resin mixture of this embodiment. For example, by performing each of the processes from S100 to S500, the calcium carbonate-containing vinyl chloride resin mixture is manufactured, and a molded article is further manufactured. Some of the processes from S100 to S500 may be omitted. In addition to the processes from S100 to S500, other processes may be performed as needed. The calcium carbonate-containing vinyl chloride resin mixture and the molded article may be produced by methods other than the flow chart shown in Figure 1.

[0048] First, in S100, a vinyl chloride resin is obtained by polymerizing a vinyl chloride monomer. If the vinyl chloride resin is a homopolymer of polyvinyl chloride, the monomer may be vinyl chloride alone. If the vinyl chloride resin is a copolymer of polyvinyl chloride and another polymer, vinyl chloride may be further polymerized together with a monomer copolymerizable with vinyl chloride. Polymerization may be carried out by suspension polymerization, but is not limited to this, and may be carried out by known methods. For example, a vinyl chloride resin can be obtained by radical polymerization of these monomers with an initiator in a solvent within a polymerization apparatus.

[0049] Any type of polymerization apparatus may be used. For example, the polymerization apparatus is a batch polymerization apparatus. For example, the polymerization apparatus comprises a reactor having a cylindrical straight section. For example, the polymerization apparatus comprises one or more cooling pipes arranged inside the reactor for circulating a refrigerant. For example, the polymerization apparatus comprises a stirring shaft arranged inside the reactor, to which one or more stirring blades are attached and which is configured to be rotatable. The stirring shaft may be configured to allow the attachment of multiple stirring blades at different positions in the direction of extension of the stirring shaft. As an example, the polymerization apparatus is described in International Publication No. 2022 / 265057.

[0050] Figure 2 shows an example of a polymerization apparatus 100. The polymerization apparatus 100 may include a reaction vessel 110. When the polymerization apparatus 100 is used to produce a polymer, polymerization is started after polymerizable monomers, polymerization initiators, aqueous media, dispersing aids, etc., are placed inside the reaction vessel 110. As a dispersing aid, for example, any surfactant may be used.

[0051] The reaction vessel 110 has, for example, a cylindrical shape. The reaction vessel 110 may have a cylindrical shape, or may have a rectangular tubular shape. The reaction vessel 110 is installed, for example, such that the extending direction of the reaction vessel 110 (the z direction in the figure) is the vertical direction.

[0052] Examples of the shape of a cross section (sometimes referred to as a transverse cross section) obtained by cutting the reaction vessel 110 along a plane perpendicular to the extending direction of the reaction vessel 110 (the xy plane in the figure) include a circle, an ellipse, a polygon, and the like. Note that the shape of the transverse cross section of the reaction vessel 110 may be a shape that can be substantially regarded as a circle, an ellipse, or a polygon.

[0053] The internal volume of the reaction vessel 110 is not particularly limited, but the internal volume of the reaction vessel 110 is, for example, 1 to 300 m ３ . The lower limit value of the internal volume of the reaction vessel 110 is 40 m ３ , may be 80 m ３ , may be 100 m ３ , may be 120 m ３ , may be 130 m ３ , may be 150 m ３ , may be 200 m ３ , or may be 250 m ３ . The upper limit value of the internal volume of the reaction vessel 110 may be 300 m ３ or more. The upper limit value of the internal volume of the reaction vessel 110 may be 350 m ３ , or may be 400 m ３ . The larger the internal volume of the reaction vessel 110, the more the improvement of the cooling capacity according to the present embodiment can act advantageously.

[0054] The internal volume of the reaction vessel 110 is defined as the capacity when the reaction vessel 110 stores liquid up to a predetermined upper limit position of the reaction vessel 110. The internal volume of the reaction vessel 110 is, for example, the internal volume of the reaction vessel 110 when no internal structures such as a stirring shaft, blades, baffles, and coils are arranged inside the reaction vessel 110.

[0055] As mentioned above, there is a trade-off between increasing the size of the reaction vessel 110 and shortening the reaction time. The internal volume of the reaction vessel 110 is 40 ml. ３ At this level, the heat removal efficiency of the polymerization apparatus 100 tends to become insufficient, making it difficult to increase the size of the reaction vessel 110 while shortening the reaction time. In particular, when the volume of the reaction vessel 110 is 80 ml ３ In the above case, the effects of the polymerization apparatus 100 according to this embodiment become more pronounced. Details of the reaction vessel 110 will be described later.

[0056] In this embodiment, the stirrer 120 stirs the liquid stored inside the reaction vessel 110. In this embodiment, the stirring shaft 122 holds the stirring blade 124 and rotates the stirring blade 124. In this embodiment, the stirring blade 124 is attached to the stirring shaft 122 and stirs the liquid stored inside the reaction vessel 110.

[0057] The shape of the stirring blade 124 is not particularly limited, but examples of the shape of the stirring blade 124 include Faudler blades, blue margin blades, paddle blades, inclined paddle blades, turbine blades, propeller blades, and combinations thereof. As a result, when the stirring shaft 122 rotates, a discharge flow is generated radially from the stirring shaft 122 toward the outer circumference. The number of blades on the stirring blade 124 is not particularly limited, but examples of the number of blades include 2 to 6. The installation position and number of stirring blades 124 are not particularly limited, but it is preferable that the stirring blades 124 be installed in multiple stages. Examples of the number of stages of the stirring blades 124 include 2 to 6 stages.

[0058] In this embodiment, the power mechanism 126 rotates the stirring shaft 122. The power mechanism 126 includes, for example, a power unit (not shown) that generates power and a power transmission unit (not shown) that transmits the power generated by the power unit to the stirring shaft 122. An electric motor is an example of the power unit. A reduction gear is an example of the power transmission unit.

[0059] The rotational speed of the stirring shaft 122, as well as the shape, size, number of blades, installation position, number of units, and installation interval Pi of the stirring blades 124, are appropriately determined according to the application of the polymerization apparatus 100. The rotational speed of the stirring shaft 122, as well as the shape, size, number of blades, installation position, number of units, and installation interval Pi of the stirring blades 124, are determined, for example, by considering the volume of the reaction vessel 110, the shape of the reaction vessel 110, the internal structures arranged inside the reaction vessel 110, the configuration of the heat removal means, the heat removal capacity, and the composition of the raw materials charged for polymerization.

[0060] In this embodiment, the baffle 130 improves the mixing performance of the polymerization apparatus 100. For example, the baffle 130 improves the vertical mixing performance inside the reaction vessel 110. The installation position of the baffle 130 is not particularly limited, but for example, the baffle 130 is positioned near the inner wall of the reaction vessel 110. The baffle 130 may be supported by the side wall of the reaction vessel 110. In another embodiment, the baffle 130 is supported by the top or bottom plate of the reaction vessel 110 and is positioned near the stirring blade 124. When the polymerization apparatus 100 is used to produce polymers, the baffle 130 may be positioned so that its upper end is submerged in the liquid phase, or it may be positioned so that its upper end is not submerged in the liquid phase.

[0061] The number of baffles 130 is preferably 1 to 12, preferably 2 to 8, more preferably 3 to 6, and even more preferably 4 to 6. It is preferable that an even number of baffles 130 are arranged substantially symmetrically around the extension axis (sometimes referred to as the central axis) of the reaction vessel 110. This further improves the mixing performance of the polymerization apparatus 100 and suppresses liquid stagnation. As a result, scale formation can be suppressed.

[0062] In this embodiment, the main body 132 of the baffle 130 improves the mixing performance of the polymerization apparatus 100. The shape of the main body 132 is not particularly limited, but the main body 132 has, for example, a plate-like or cylindrical shape that extends substantially parallel to the extension direction of the reaction vessel 110. If the main body 132 has a cylindrical shape, the diameter of the main body 132 may be 40 to 500 mm. The length Bh (sometimes referred to as height Bh) of the main body 132 in the extension direction (z direction in the figure) is not particularly limited.

[0063] The length Bw (sometimes referred to as width Bw) of the main body 132 in a direction substantially perpendicular to the extension direction (the x or y direction in the figure) is not particularly limited. The ratio of the width Bw of the main body 132 to the inner diameter of the reaction vessel 110 may be 1 to 10%, 2.5 to 7.5%, or 3 to 7%.

[0064] If the main body 132 has a cylindrical shape, the ratio of the total area of ​​the cross-sectional areas of one or more cylindrical main bodies 132 to the area of ​​the cross-sectional area of ​​the straight body of the reaction vessel 110 may be 0.4 to 3%. If the above ratio is less than 0.4%, the function as a baffle will be insufficient, and vertical mixing inside the reaction vessel 110 may become insufficient. For example, if the polymerization apparatus 100 is equipped with a single baffle 130, the above ratio may be less than 0.4%. For example, in the suspension polymerization of vinyl chloride monomers, if vertical mixing inside the reaction vessel 110 is insufficient, the particle size distribution of the produced polymer may become broad. As a result, when the produced polymer is molded into a sheet, for example, fish eyes may increase, and the quality of the molded product may deteriorate.

[0065] On the other hand, if the above ratio exceeds 3%, the power required for the agitator 120 will increase excessively. Also, the fluidity of the liquid between the baffle 130 and the inner wall surface of the reaction vessel 110 may decrease. As a result, scale may be more likely to adhere to the reaction vessel 110 or the internal structures of the reaction vessel 110. For example, if the polymerization apparatus 100 is equipped with more than eight baffles 130, the above ratio may exceed 3% depending on the design of the polymerization apparatus 100.

[0066] At least one baffle 130 body 132 may have a passage for circulating a heat transfer medium. The passage may be formed inside the body 132 or located outside the body 132. The passage may be a single pipe or may have a double pipe structure.

[0067] The main body 132 is connected to the inner wall surface of the reaction vessel 110, for example, via a support 134. The distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is preferably 40 mm or more. If the above distance is less than 40 mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the baffle 130 near the gas-liquid interface inside the reaction vessel 110. Details of the main body 132 will be described later.

[0068] In this embodiment, the support 134 holds the main body 132. For example, one end of the support 134 is in contact with the inner wall surface of the reaction vessel 110, and the other end of the support 134 is in contact with the main body 132. As described above, the support 134 may hold the main body 132 such that the distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is 40 mm or more.

[0069] In this embodiment, the serpentine cooler 140 has a flow path formed inside for circulating a heat transfer medium. The serpentine cooler 140 may be a single-walled tube. The serpentine cooler 140 is positioned closer to the central axis of the reaction vessel 110 than the serpentine cooler 150. The number of serpentine coolers 140 is preferably 1 to 12, preferably 2 to 8, more preferably 3 to 6, and even more preferably 4 to 6. It is preferable that an even number of serpentine coolers 140 are arranged substantially symmetrically around the central axis of the reaction vessel 110.

[0070] The heat transfer medium may be a known refrigerant. Examples of refrigerants include water, brine, Freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, it may function as a refrigerant by evaporating inside the meandering cooling tube 140. The linear velocity of the refrigerant may be approximately 0.1 to 6.0 m / s.

[0071] In this embodiment, at least a portion of the meandering cooling tube 140 extends while repeatedly bending. The length Ph in the extension direction of the portion of the meandering cooling tube 140 that extends while repeatedly bending may be smaller than the length Bh in the extension direction (z-direction in the figure) of the main body 132 of the baffle 130, may be approximately the same as Bh, or may be larger than Bh. This increases the heat transfer area per unit area.

[0072] In the example shown in Figure 2, the meandering condenser 140 extends approximately parallel to the extension direction of the reaction vessel 110 while repeatedly bending. In the example shown in Figure 2, the entire meandering condenser 140 extends while repeatedly bending. The ratio of the length Ph of the portion of the meandering condenser 140 that extends while repeatedly bending to the total length Pt (not shown) of the meandering condenser 140 in the extension direction may be 0.25 or more, 0.5 or more, 0.75 or more, 0.8 or more, or 0.9 or more.

[0073] The meandering cooler tube 140 may be positioned so that its upper end is submerged in the liquid phase when the polymerization apparatus 100 is used to produce polymers. This is because if the upper part of the meandering cooler tube 140 is exposed to the gas phase, the heat transfer efficiency will decrease and polymer scale will be more likely to adhere to the meandering cooler tube 140. In the final stages of polymerization, the gas-liquid interface will be lowered due to liquid shrinkage. Therefore, it is preferable that the meandering cooler tube 140 is positioned so that even at the end of polymerization, there is a sufficient distance between its upper end and the gas-liquid interface. Details of the meandering cooler tube 140 will be described later.

[0074] In this embodiment, the serpentine condenser 150 has a flow path formed inside for circulating a heat transfer medium. The serpentine condenser 150 may be a single-walled tube. The serpentine condenser 150 is positioned closer to the side wall of the reaction vessel 110 than the serpentine condenser 140. The number of serpentine condensers 150 is preferably 1 to 12, preferably 2 to 8, more preferably 3 to 6, and even more preferably 4 to 6. The number of serpentine condensers 150 may be the same as or different from the number of serpentine condensers 140. It is preferable that an even number of serpentine condensers 150 are arranged substantially symmetrically around the central axis of the reaction vessel 110.

[0075] The heat transfer medium may be a known refrigerant. Examples of refrigerants include water, brine, Freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, it may function as a refrigerant by evaporating inside the meandering cooling tube 140. The linear velocity of the refrigerant may be approximately 0.1 to 6.0 m / s.

[0076] In this embodiment, at least a portion of the meandering cooling tube 150 extends while repeatedly bending. The length Ph in the extension direction of the portion of the meandering cooling tube 150 that extends while repeatedly bending may be smaller than the length Bh in the extension direction (z-direction in the figure) of the main body 132 of the baffle 130, may be approximately the same as Bh, or may be larger than Bh. This increases the heat transfer area per unit area.

[0077] In the example shown in Figure 2, the meandering condenser 150 extends approximately parallel to the extension direction of the reaction vessel 110, while repeatedly bending. In the example shown in Figure 2, the entire meandering condenser 150 extends while repeatedly bending. The ratio of the length Ph of the portion of the meandering condenser 150 that extends while repeatedly bending to the total length Pt (not shown) of the meandering condenser 150 in the extension direction may be 0.25 or more, 0.5 or more, 0.75 or more, 0.8 or more, or 0.9 or more.

[0078] The meandering cooler tube 150 may be positioned so that its upper end is submerged in the liquid phase when the polymerization apparatus 100 is used to produce polymers. This is because if the upper part of the meandering cooler tube 150 is exposed to the gas phase, the heat transfer efficiency will decrease and polymer scale will be more likely to adhere to the meandering cooler tube 150. In the final stages of polymerization, the gas-liquid interface will be lowered due to liquid shrinkage. Therefore, it is preferable that the meandering cooler tube 150 be positioned so that even at the end of polymerization, there is a sufficient distance between its upper end and the gas-liquid interface.

[0079] In one embodiment, the direction of flow of the refrigerant in the meandering cooling pipe 150 is set so that the refrigerant flows from below the reaction vessel 110 towards the top of the reaction vessel 110. In another embodiment, the direction of flow of the refrigerant in the meandering cooling pipe 150 is set so that the refrigerant flows from above the reaction vessel 110 towards the bottom of the reaction vessel 110.

[0080] For example, the liquid returned from the reflux condenser 180 is at a lower temperature and has a higher density than the liquid inside the reaction vessel 110. Therefore, near the inlet of the liquid returned from the reflux condenser 180, the liquid inside the reaction vessel 110 tends to flow from top to bottom. Thus, for example, a meandering condenser 150 located near the inlet of the liquid returned from the reflux condenser 180 can be configured to allow the refrigerant to flow from the bottom to the top of the reaction vessel 110. Details of the meandering condenser 150 will be described later.

[0081] In this embodiment, the jacket 170 heats or cools the reaction vessel 110 from outside the reaction vessel 110. As described above, the jacket 170 has a flow path 172 through which a heat transfer medium can flow. The jacket 170 adjusts the amount of heat heated and removed from the reaction vessel 110 by controlling at least one of the temperature and flow rate of the heat transfer medium flowing through the flow path 172.

[0082] The heat transfer medium may be a known refrigerant. Examples of refrigerants include water, brine, Freon, and various liquefied gases. It is preferable to use a liquid refrigerant. When a liquefied gas is used as the refrigerant, the liquefied gas may function as a refrigerant by evaporating inside the meandering cooling tube 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0083] In this embodiment, the reflux condenser 180 is used to remove heat from the reaction vessel 110. For example, steam from the reaction vessel 110 is supplied to the reflux condenser 180. The reflux condenser 180 cools and liquefies the steam. The reflux condenser 180 returns the liquid produced by the cooling to the reaction vessel 110. As described above, the reflux condenser 180 has a flow path 182 through which a heat transfer medium can flow. The reflux condenser 180 cools the steam from the reaction vessel 110 by heat exchange between the heat transfer medium flowing through the flow path 182 and the steam from the reaction vessel 110. The amount of heat removed from the reaction vessel 110 can be adjusted by controlling at least one of the temperature and flow rate of the heat transfer medium flowing through the flow path 182.

[0084] Known initiators may be used. For example, the initiator is one or more selected from the group consisting of azobis compounds, organic peroxides, inorganic peroxides, and redox initiator systems. As an example, an organic peroxide is benzoyl peroxide. As an example, an inorganic peroxide is sodium persulfate. As an example, a redox initiator system is a combination of azobis compounds, organic peroxides, inorganic peroxides, etc., and amines, etc.

[0085] For example, initiators include 4,4'-azobis(4-cyanovaleric acid), sodium peroxodisulfate, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]n hydrate, 2,2'-azobis(isobutyronitrile), and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

[0086] The initiator content may be 0.01 parts by weight or more and 1 part by weight or less, preferably 0.05 parts by weight or more and 0.5 parts by weight or less, per 100 parts by weight of monomer.

[0087] Other components may be added to the polymerization reaction system. For example, chain transfer agents such as alcohols, mercaptans, and halogenated carbons may be added to the polymerization reaction system.

[0088] The solvent in the polymerization reaction system may be an aqueous solvent. For example, the solvent may be distilled water or purified water such as deionized water. The solvent may further contain organic solvents such as alcohols. The solvent content may be 100 parts by weight or more and 2000 parts by weight or less, preferably 500 parts by weight or more and 1000 parts by weight or less, per 100 parts by weight of monomer.

[0089] In addition to S100, optionally, in S110, a chlorinated vinyl chloride resin may be obtained by further chlorinating the polyvinyl chloride homopolymer or copolymer. For example, a chlorinated vinyl chloride resin can be obtained by introducing chlorine gas into the polyvinyl chloride homopolymer or copolymer. The chlorination of polyvinyl chloride is not limited to this and may be carried out by known methods.

[0090] Next, in S200, a calcium carbonate-containing composition derived from waste is obtained by contacting the calcium-containing waste with carbon dioxide. For example, calcium-containing waste such as concrete waste or limestone is crushed into particles. These are then suspended in a solvent such as water to produce a suspension. A calcium carbonate-containing composition may be obtained by contacting the suspension with carbon dioxide derived from exhaust gas.

[0091] Contact may be carried out by bubbling or the like using any container. The same stirrer used for stirring in S300 may be used as the container. Contact may be carried out at a temperature of 50°C to 400°C. In terms of yield, it is preferable that the reaction is carried out so that the ratio of calcium-containing composition to carbon dioxide is approximately 1:1 in stoichiometric ratio (molar ratio).

[0092] The contact may be carried out for one hour or more, preferably two hours or more, and more preferably three hours or more. To ensure that the reaction proceeds sufficiently, it is preferable to contact the calcium-containing composition with carbon dioxide while stirring. After the reaction is complete, the calcium-containing composition may be dehydrated by decantation or dried to form a solid such as a powder.

[0093] Alternatively, in S200, the washing wastewater sludge discharged from the cement concrete mixing equipment may be used as cement-containing waste, and this may be immersed in water to create a slurry of a predetermined concentration (for example, about 1 to 30% by weight). Next, the slurry waste may be placed in a container, and exhaust gas containing carbon dioxide (for example, carbon dioxide concentration of about 1 to 30% by volume) discharged from the cement manufacturing equipment may be supplied at a fixed rate (for example, about 1 to 50 liters per minute per 1 kg of solid matter) for a fixed time (for example, 1 to 300 minutes). This will cause the calcium component in the slurry waste to react with the carbon dioxide in the exhaust gas to obtain calcium carbonate. The solid component may be separated from the obtained calcium carbonate and dried to obtain the calcium-containing composition.

[0094] Alternatively, in S200, a first slurry may be prepared by mixing cement-containing waste such as concrete sludge with water. Next, the first slurry may be stirred at a predetermined rotation speed (for example, about 50 to 2000 revolutions per minute) at room temperature for a certain period of time (for example, 1 to 300 minutes). Combustible waste gas containing carbon dioxide may be supplied to the first slurry at a constant flow rate (for example, a flow rate of about 0.1 to 5.0 liters per minute per 1 kg of solid content) for about 3 hours while stirring to fix the carbon dioxide as calcium carbonate. The second slurry containing the fixed calcium carbonate may be separated into solid and liquid components, and the dried solid component may be used as the calcium-containing composition. Alternatively, the second slurry containing the fixed calcium carbonate may be used as the calcium-containing composition without solid-liquid separation into solid and liquid components. In S200, a calcium-containing composition derived from calcium-containing waste may be obtained that contains 10% by mass or more and 80% by mass or less of calcium carbonate derived from the calcium-containing waste, preferably 30% by mass or more and 70% by mass or less, and more preferably 35% by mass or more and 60% by mass or less.

[0095] Next, in S300, the vinyl chloride resin obtained in S100 or S110, the calcium carbonate-containing composition obtained in S200, and a lubricant are mixed to produce a calcium carbonate-containing vinyl chloride resin mixture (sometimes simply referred to as the "mixture") by mixing or stirring (sometimes referred to as "kneading"). The lubricant may contain at least one of the following: metal soap lubricants, fatty acid lubricants, hydrocarbon lubricants, ester lubricants, fatty acid amide lubricants, and silicone lubricants. The lubricant may be included in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin. By using a lubricant, the generation of heat due to friction is suppressed, the shearing and decomposition of the vinyl chloride resin is suppressed, and foaming and discoloration due to hydrogen chloride gas can be suppressed. Mixing or stirring may be carried out using any rotary mixer. From the viewpoint of uniform mixing by convection of the resin composition, examples of rotary mixers that can be used include Henschel mixers, super mixers, and ribbon blenders.

[0096] There are no particular restrictions on the rotational speed and / or discharge temperature of the rotary mixer described above, but for example, in the case of a Henschel mixer, it is preferable to use a rotational speed of 100 rpm or more and 2500 rpm or less, and more preferably 500 rpm or more and 2000 rpm or less. If the rotational speed of the rotary mixer is less than 100 rpm, calcium carbonate may aggregate due to poor dispersion, which may lead to a decrease in physical properties. If the rotational speed of the rotary mixer exceeds 2500 rpm, it may become difficult to uniformly control the mixing temperature due to excessive heat generation.

[0097] Furthermore, when stirring and mixing with the rotary mixer (such as a Henschel mixer), the mixture is rotary mixed at a temperature of 10 to 40°C, preferably 20 to 30°C, and discharged when the temperature rises to 100 to 140°C, preferably 110 to 130°C, thereby obtaining a powder mixture of resin (sometimes called a "compound"). The mixing time for the materials can be 0.05 hours or more and 2.0 hours or less, preferably 0.05 hours or more and 1.0 hour or less, preferably 0.05 hours or more and 0.5 hours or less.

[0098] In this invention, it was found that when a calcium carbonate-containing vinyl chloride resin mixture was prepared using a calcium carbonate-containing composition derived from calcium-containing waste, surface defects such as foaming due to thermal decomposition during extrusion occurred compared to when ordinary calcium carbonate was used. After diligent investigation into the cause, it was found that the calcium carbonate-containing vinyl chloride resin mixture using a calcium carbonate-containing composition derived from calcium-containing waste is prone to thermal decomposition due to shear. Specifically, in a chamber with a volume of 60 cm³... ３An evaluation was conducted using a closed-type twin-screw mixer under two conditions: Condition 1, with a temperature of 180°C, a rotation speed of 60 rpm, and a filling amount of 72 g; and Condition 2, with a temperature of 200°C, a rotation speed of 40 rpm, and a filling amount of 67 g. Compared to Condition 2, Condition 1 involved lower temperature, higher rotation speed, and a higher filling amount, resulting in higher viscosity of the molten material during the test, a faster shear rate, and greater heat generation due to the larger input volume and higher resin pressure. Compared to Condition 1, Condition 2 was less susceptible to shear, but received more heat from the chamber surface due to the higher temperature.

[0099] In conclusion, to obtain good moldability, a chamber volume of 60 cm³ is required. ３ The decomposition time of the calcium carbonate-containing vinyl chloride resin mixture when mixed using a closed-type twin-screw mixer at a temperature of 180°C, a rotation speed of 60 rpm, and a filling amount of 72 g may be longer than the decomposition time of the calcium carbonate-containing vinyl chloride resin mixture when mixed at a temperature of 200°C, a rotation speed of 40 rpm, and a filling amount of 67 g. Chamber volume: 60 cm³ ３ The difference between the decomposition time of a calcium carbonate-containing vinyl chloride resin mixture when mixed using a closed twin-screw kneader at a temperature of 180°C, a rotation speed of 60 rpm, and a filling amount of 72 g, and the difference between the decomposition time of a calcium carbonate-containing vinyl chloride resin mixture when mixed at a temperature of 200°C, a rotation speed of 40 rpm, and a filling amount of 67 g, may be 30 seconds, 1 minute, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, or 180 minutes. Preferably, the difference should be 1 minute or more, and more preferably 3 minutes or more.

[0100] In the above, the closed-type twin-screw compounder may be a Laboplastmill or a Brabender.

[0101] Next, in S500, the mixture after mixing or stirring is molded. The mixture may be extruded into pellets before the final molding process. There are no particular restrictions on the method of molding the above calcium carbonate-containing vinyl chloride resin mixture (also called "final molding"), but it is preferable to use a molding method selected from the group consisting of extrusion molding, press molding, injection molding, and calendering.

[0102] Prior to the above molding process, the powder compound can be pre-melted. Examples of this pre-melting process include using a Banbury mixer, extrusion molding, or roll molding, or using a method of shredding these to pelletize them to a size of approximately 0.5 to 10 mm, more preferably 1 to 7 mm. It is preferable to knead the mixture at a temperature of 140 to 200°C for 2 to 12 minutes during this pre-melting process. In the case of pre-melting using extrusion molding, for example, a calcium carbonate-containing vinyl chloride resin mixture can be melted in an extruder at 140 to 180°C, the screw speed can be controlled to 20 to 60 rpm, and pellets can be obtained by making pellets with a longitudinal dimension of approximately 0.5 to 10 mm. In the case of roll forming, it is preferable to feed the powder compound into two rolls (3 to 9 inches in diameter and, for example, at approximately 10 to 30 rpm), knead it at 160 to 200°C for 1 to 30 minutes, preferably 1 to 10 minutes, to form a sheet with a thickness of 0.1 to 5 mm.

[0103] The molded product may then be formed by injection molding, extrusion molding, press molding, or calendering, but is not limited to these methods; any molding method can be used depending on the intended use of the molded product. The molded product can be suitably used for various industrial products such as pipes, fittings, rain gutters, flat plates, corrugated sheets, wallpaper, films, sheets, and bathtub lids. The thickness of the molded product can be adjusted according to the desired application, but it is preferable to have a thickness of 1 μm to 100 mm, preferably 10 μm to 10 mm.

[0104] [Examples] Examples are shown below, but these embodiments are not limited to these examples.

[0105] (Polymerization of vinyl chloride) The polymerization reaction was carried out using the polymerization apparatus described in Reference Example 1 of International Publication No. 2022 / 265057. First, 32,900 kg of deionized water, 10.5 kg of partially saponified polyvinyl alcohol with a degree of saponification of 80.0 mol%, and 4.5 kg of hydroxypropyl methylcellulose with a degree of methoxy substitution of 28.5% by mass and a degree of hydroxypropyl substitution of 8.9% were prepared as aqueous solutions and added to the reaction vessel of the polymerization apparatus. Next, 30,100 kg of vinyl chloride monomer was added to the reaction vessel. Then, while stirring the mixed solution with a stirrer, polymerization initiators A, B, and C were pumped into the reaction vessel.

[0106] As polymerization initiator A, an isoparaffin solution containing di-2-ethylhexyl peroxydicarbonate was used. The amount of di-2-ethylhexyl peroxydicarbonate added was 22.1 kg. As polymerization initiator B, an isoparaffin solution containing t-butyl peroxyneodecanate was used. The amount of t-butyl peroxyneodecanate added was 3.2 kg. As polymerization initiator C, an isoparaffin solution containing cumyl peroxyneodecanate was used. The amount of cumyl peroxyneodecanate added was 5.0 kg.

[0107] Next, polymerization was initiated by raising the temperature of the mixed solution inside the reaction vessel to 60°C. When the temperature of the mixed solution inside the reaction vessel reached 60°C, the flow of cooling water to the cooling pipe was started. Under conditions that the temperature of the mixed solution inside the reaction vessel was maintained at 60°C, cooling was stopped when the pressure inside the reaction vessel decreased by 0.09 MPa compared to the average pressure after the start of polymerization.

[0108] Eighteen minutes after the cooling was stopped, a sufficient amount of triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] aqueous dispersion (concentration: 40% by mass) to stop the polymerization reaction was added to the reaction vessel. This terminated the polymerization reaction, and a vinyl chloride polymer (polyvinyl chloride) was obtained. The obtained vinyl chloride polymer (polyvinyl chloride) is referred to as vinyl chloride polymer A (degree of polymerization 800).

[0109] (Production of calcium carbonate-containing composition) As heavy calcium carbonate not derived from calcium-containing waste, Softon 1800 (manufactured by Bihoku Powdering Industry Co., Ltd., average primary particle size 1.25 μm, BET 18000 cm) ２ A calcium carbonate ( / g) was used. This is referred to as calcium carbonate-containing composition B. Calcium carbonate not derived from calcium-containing waste can be used comparatively or supplementarily, but the effects of the present invention are significantly expressed by using calcium carbonate derived from waste.

[0110] A cement regeneration material was obtained as a calcium carbonate-containing composition by the method of Example 1 described in International Publication No. 2024 / 190776. Specifically, a first slurry was obtained by mixing 45 g of ordinary Portland cement with 450 g of water. Next, the first slurry was stirred with a stirrer at a speed of 800 rpm for 3 hours at 20°C. Then, carbon dioxide was supplied to the first slurry at a rate of 500 mL per minute by bubbling, and the reaction was stopped when the pH of the first slurry became constant near neutral, to obtain a second slurry. The second slurry was separated into solid and liquid components, and the solid component was dried to obtain the cement regeneration material. This cement regeneration material is referred to as calcium carbonate-containing composition C. The calcium carbonate content of calcium carbonate-containing composition C is 50%, and the calcium carbonate content was calculated from the amount of Ca obtained by a fluorescent X-ray analyzer.

[0111] (Mixture Production: Production Example A1 as an Example) A Henschel mixer (manufactured by Nippon Coke Industries Co., Ltd., FM10C / 1) with a total mixing tank capacity of approximately 10 L was prepared as a rotary mixer. ST blades (standard) were used as the upper blades of the Henschel mixer. AO blades (standard) were used as the lower blades of the Henschel mixer. Next, the raw materials were added to the mixing tank of the Henschel mixer. Specifically, 1000 g of vinyl chloride polymer A, 250 g of calcium carbonate-containing composition C, 2.5 g of calcium stearate and 10 g of zinc stearate as metal lubricants, 10 g of hydrotalcite, 2.5 g of dibenzoylmethane and 2.5 g of dipentaerythritol as stabilizers, 20 g of polyester wax (molecular weight 4000) as an ester lubricant, and 10 g of polyethylene wax (molecular weight 5500) as a hydrocarbon lubricant were added to the mixing tank of the Henschel mixer. The raw materials were placed in a Henschel mixer at 25°C and blended for 0.1 hours at a rotation speed of 1800 rpm. The mixture was then discharged at 120°C to produce a compound (referred to as mixture A1).

[0112] Next, as a test evaluation, the compound was subjected to a closed twin-screw mixer (chamber capacity 60 cm³). ３ 72g was added to the mixture and kneaded at 180°C at a rotation speed of 60 rpm.

[0113] (Formation of the mixture: Production example A2 as an example) Mixture A1 was kneaded in the same manner as in Production Example A1, except that 67 g of mixture A1 was added and kneaded at a temperature of 200°C and a rotation speed of 40 rpm.

[0114] (Evaluation of decomposition time) Table 1 shows the decomposition times for manufacturing example A1 and manufacturing example A2. Decomposition time was defined as the time at which the torque of the twin-screw mixer began to increase sharply.

[0115] (Evaluation of surface properties of extruded samples) Each compound was formed into a 1 mm thick sheet using a 20 mm diameter single-screw extruder. The extrusion conditions were set as follows: Cylinder temperature was set to 140°C for cylinder 1 and 150°C for cylinder 2, starting from the position closest to the raw material inlet; adapter mold temperature was set to 160°C; mold temperature was set to 170°C; and a T-die was used for the mold. The surface of the formed sheets was visually inspected and evaluated according to the following criteria: ○: Almost no foaming or roughness observed. △: Some foaming or roughness observed. ×: A lot of foaming or roughness.

[0116] Thus, the decomposition time was longer for manufacturing example A1, which was compounded at a temperature of 180°C and a rotation speed of 60 rpm, compared to manufacturing example A2, which was compounded at a temperature of 200°C and a rotation speed of 40 rpm. This demonstrates that adding a lubricant to the mixture can suppress the heat generated during compounding, thereby inhibiting the decomposition of the vinyl chloride resin. Furthermore, both manufacturing examples A1 and A2 showed excellent surface quality in the extruded samples.

[0117] (Mixture Preparation: Production Example B1 as an Example) The mixtures of Production Examples B1 to K2 were prepared in the same manner as in Production Example A1. Except for changing the amount of calcium stearate to 5 g, zinc stearate to 20 g, polyester wax (molecular weight 4000), and polyethylene wax (molecular weight 5500) to 40 g (i.e., doubling the amount of lubricant in the mixture), the evaluation was the same as in Production Example A1.

[0118] (Formation of the mixture: Production example B2 as an example) The evaluation was the same as in Production Example A2, except that the amount of calcium stearate was changed to 5 g, zinc stearate to 20 g, polyester wax (molecular weight 4000) to 40 g, and polyethylene wax (molecular weight 5500) to 20 g (i.e., the amount of lubricant in the mixture was doubled).

[0119] (Formation of the mixture: Production example C1 as a comparative example) The evaluation was the same as in Production Example A1, except that calcium stearate was changed to 0 g, zinc stearate to 0 g, polyester wax (molecular weight 4000) to 0 g, and polyethylene wax (molecular weight 5500) to 0 g (i.e., no lubricant was present in the mixture).

[0120] (Formation of the mixture: Production example C2 as a comparative example) The evaluation was the same as in Production Example A2, except that calcium stearate was changed to 0 g, zinc stearate to 0 g, polyester wax (molecular weight 4000) to 0 g, and polyethylene wax (molecular weight 5500) to 0 g (i.e., no lubricant was present in the mixture).

[0121] (Formation of the mixture: Production example D1 as an example) The evaluation was the same as in Production Example A1, except that the amount of polyester wax (molecular weight 4000) was changed to 0 g and polyethylene wax (molecular weight 5500) was changed to 0 g (i.e., hydrocarbon lubricants and ester lubricants were not present in the mixture).

[0122] (Formation of the mixture: Production example D2 as an example) The evaluation was the same as in Production Example A2, except that the amount of polyester wax (molecular weight 4000) was changed to 0 g and polyethylene wax (molecular weight 5500) was changed to 0 g (i.e., hydrocarbon lubricants and ester lubricants were not present in the mixture).

[0123] (Production of the mixture: Production example E1 as an example) A compound (referred to as mixture E1) was prepared by mixing 1000 g of vinyl chloride polymer A, 125 g of calcium carbonate-containing composition B, 125 g of calcium carbonate-containing composition C, 2.5 g of calcium stearate, 10 g of zinc stearate, 10 g of hydrotalcite, 2.5 g of dibenzoylmethane, and 2.5 g of dipentaerythritol. Subsequently, as a test evaluation, the compound was processed in a closed twin-screw mixer (chamber capacity 60 cm³). ３72g was added to ) and kneaded at a temperature of 180°C and a rotation speed of 60 rpm. (Formation of mixture: Production example E2 as an example) A mixture was obtained in the same manner as in Production Example E1, except that 67g of mixture E1 was added and kneaded at a temperature of 200°C and a rotation speed of 40 rpm.

[0124] (Formation of the mixture: Production example F1 as an example) The evaluation was the same as in Production Example E1, except that hydrotalcite was changed to 0 g, dibenzoylmethane to 0 g, and dipentaerythritol to 0 g (i.e., no stabilizers were present in the mixture).

[0125] (Formation of the mixture: Production example F2 as an example) The evaluation was the same as in Production Example E2, except that hydrotalcite was changed to 0 g, dibenzoylmethane to 0 g, and dipentaerythritol to 0 g (i.e., no stabilizers were present in the mixture).

[0126] (Formation of mixture: Production example G1 as a comparative example) A compound (referred to as mixture G1) was prepared by mixing 1000 g of vinyl chloride polymer A and 900 g of calcium carbonate-containing composition C. Subsequently, as a test evaluation, the compound was put into a closed twin-screw mixer (chamber capacity 60 cm³). ３ 72g was added to the mixture and kneaded at a temperature of 180°C and a rotation speed of 60 rpm. (Formation of mixture: Production example G2 as a comparative example) A mixture was obtained in the same manner as in production example G1, except that 67g of mixture G1 was added and kneaded at a temperature of 200°C and a rotation speed of 40 rpm.

[0127] (Production of the mixture: Production example H1 as an example) A compound (referred to as mixture H1) was prepared by mixing 1000 g of vinyl chloride polymer A, 900 g of calcium carbonate-containing composition C, 10 g of barium stearate, 10 g of zinc stearate, 20 g of epoxidized soybean oil, and 300 g of DEHP (bis(2-ethylhexyl) phthalate). Subsequently, as a test evaluation, the compound was put into a closed twin-screw mixer (chamber capacity 60 cm³). ３72g was added to the mixture and kneaded at a temperature of 180°C and a rotation speed of 60 rpm. (Formation of mixture: Production example H2 as an example) A mixture was obtained in the same manner as in production example H1, except that 67g of mixture H1 was added and kneaded at a temperature of 200°C and a rotation speed of 40 rpm.

[0128] (Formation of mixture: Production example I1 as a comparative example) A compound (referred to as mixture I1) was prepared by mixing 1000 g of vinyl chloride polymer A, 250 g of calcium carbonate-containing composition C, 20 g of hydrotalcite, 5 g of dibenzoylmethane, and 5 g of dipentaerythritol. Subsequently, as a test evaluation, the compound was processed in a closed twin-screw mixer (chamber capacity 60 cm³). ３ 72g was added to the mixture and kneaded at a temperature of 180°C and a rotation speed of 60 rpm.

[0129] (Formation of the mixture: Production example I2 as a comparative example) Mixture I1 was kneaded in the same manner as in production example I1, except that 67 g of mixture I1 was added and kneaded at a temperature of 200°C and a rotation speed of 40 rpm.

[0130] (Formation of the mixture: Production example J1 as an example) The evaluation was the same as in Production Example I1, except that 5 g of calcium stearate and 20 g of zinc stearate were added, and hydrotalcite was changed to 10 g, dibenzoylmethane to 2.5 g, and dipentaerythritol to 2.5 g.

[0131] (Formation of the mixture: Production example J2 as an example) The evaluation was the same as in Production Example I2, except that 5 g of calcium stearate and 20 g of zinc stearate were added, and hydrotalcite was changed to 10 g, dibenzoylmethane to 2.5 g, and dipentaerythritol to 2.5 g.

[0132] (Formation of the mixture: Production example K1 as an example) The evaluation was the same as in Production Example I1, except that 2.5 g of calcium stearate and 10 g of zinc stearate were added.

[0133] (Formation of the mixture: Production example K2 as an example) The evaluation was the same as in Production Example I2, except that 2.5 g of calcium stearate and 10 g of zinc stearate were added.

[0134] For the mixtures of manufacturing examples B1 to K2, the temperature and torque of the mixture during mixing were measured using a twin-screw mixing test apparatus (manufactured by Toyo Seiki Co., Ltd., product name Laboplast Mill (Type C), mixer R60H, roller blade R60B) during the mixing time. The results for manufacturing example D1 are shown in Figure 3, and the results for manufacturing example D2 are shown in Figure 4. In Figures 3 and 4, the horizontal axis represents the mixing time (seconds), and the vertical axis represents the temperature (°C) and torque (N・m) of the mixture.

[0135] Tables 2 and 3 show the decomposition times and surface properties of the extruded samples for manufacturing examples B1 to K2. Decomposition time was defined as the time at which the torque of the twin-screw mixer began to increase sharply.

[0136] From the results in Figures 3 and 4, the mixtures according to Production Example D1 and Production Example D2 of the present invention showed that the use of calcium carbonate derived from calcium-containing waste resulted in greater heat generation due to shearing. Under the conditions of input amount of 72 g, temperature of 180°C, and rotation speed of 60 rpm (Production Example D1), the decomposition of the vinyl chloride resin (calcium carbonate-containing vinyl chloride resin mixture) progressed more rapidly than under the conditions of input amount of 67 g, temperature of 200°C, and rotation speed of 40 rpm (Production Example D2) (Table 2). This is because, under the conditions of 180°C and rotation speed of 60 rpm, the viscosity of the molten material was higher and the shear rate was faster during the test. As a result, the decomposition of the vinyl chloride resin (calcium carbonate-containing vinyl chloride resin mixture) due to heat generation was significantly more pronounced in the mixtures according to Production Example D1 and Production Example D2, where heat generation due to shearing was greater. However, by adjusting the lubricity and melt viscosity of the compound, the generation of heat due to shear can be suppressed, and it has become clear that the decomposition of the vinyl chloride resin (calcium carbonate-containing vinyl chloride resin mixture) is suppressed more effectively under the conditions of 72g input, 180°C, and 60rpm (production example A1) than under the conditions of 67g input, 200°C, and 40rpm (production example A2) (Table 1). In other words, in production examples D1 and D2, the type and amount of lubricant are insufficient, so the suppression effect of shear heat generation is insufficient. On the other hand, in production examples A1 and A2, the type and amount of lubricant are appropriately adjusted, so it is thought that the generation of heat due to shear is suppressed. If the decomposition time under conditions of 180°C and 60 rpm is longer than the decomposition time under conditions of 200°C and 40 rpm, it can be evaluated that the heat generation due to shear is suppressed to some extent, and even when the calcium carbonate-containing vinyl chloride resin mixture is produced in an extruder (especially a real machine with a high shear rate), decomposition and / or foaming of the calcium carbonate-containing vinyl chloride resin mixture is less likely to occur.

[0137] Production examples B1 and B2 were obtained by adding double the amount of lubricant compared to production examples A1 and A2, respectively. By increasing the amount of lubricant, the decomposition time of production examples B1 and B2 became longer than that of production examples A1 and A2, respectively.

[0138] Production examples C1 and C2 are the same as production examples A1 and A2, but with all lubricants removed. Because of the absence of lubricants, the vinyl chloride resin decomposed rapidly in production examples C1 and C2. In particular, the decomposition time of production example C1, under low-temperature and high-speed conditions, was shorter than that of production example C2, under high-temperature and low-speed conditions. Since shear heat generation occurs when a mixture is kneaded at high speed, this suggests that lubricants have an effect in suppressing shear heat generation.

[0139] Production examples D1 and D2 contain only the metallic lubricants (calcium stearate and zinc stearate) found in production examples A1 and A2, respectively, and do not contain polyester wax or polyethylene wax. Although production examples D1 and D2 have longer decomposition times than production examples C1 and C2, respectively, they are shorter than production examples A1 and A2, respectively. This suggests that the lubricant has a dose-dependent effect in suppressing the decomposition of the mixture. Production examples A1 and A2, and production examples B1 and B2, by including a combination of a metallic lubricant and at least one of a hydrocarbon lubricant and an ester lubricant, have the effect of having a longer decomposition time compared to production examples D1 and D2, which contain only a metallic lubricant.

[0140] Production examples E1 and E2 were created by replacing half of the calcium carbonate in production examples A1 and A2, respectively, with calcium carbonate that was not derived from waste. Since production examples E1 and E2 do not contain polyester wax or polyethylene wax, their decomposition times are shorter than those of production examples A1 and A2, respectively. This suggests that the lubricant has a dose-dependent effect in suppressing the decomposition of the mixture.

[0141] Production examples F1 and F2 do not contain the stabilizers found in production examples E1 and E2, respectively. Because production examples F1 and F2 do not contain stabilizers, their decomposition times are shorter than those of production examples E1 and E2, respectively. This suggests that stabilizers also contribute to suppressing the decomposition of the mixture.

[0142] Production examples G1 and G2 were obtained by increasing the amount of calcium carbonate from 250 g to 900 g compared to production examples C1 and C2, respectively. Because production examples G1 and G2 did not contain a lubricant, they decomposed more quickly than production examples C1 and C2, respectively.

[0143] Production examples H1 and H2, by adding lubricants and plasticizers to production examples G1 and G2 respectively, showed lower melt viscosity and longer decomposition time compared to production examples G1 and G2. This suggests that lubricants and plasticizers have the effect of suppressing the decomposition of the mixture.

[0144] Because manufacturing examples I1 and I2 contained no lubricant whatsoever, they decomposed in a much shorter time compared to manufacturing examples J1 and J2, respectively.

[0145] Production examples J1 and J2 were obtained by adding a metallic lubricant to production examples I1 and I2, respectively. Due to the presence of the metallic lubricant, production examples J1 and J2 had longer decomposition times than production examples I1 and I2, respectively.

[0146] Production examples K1 and K2 were obtained by adding a metallic lubricant to production examples I1 and I2, respectively. Production examples K1 and K2 had longer decomposition times than production examples I1 and I2, respectively, due to the presence of the metallic lubricant. Here, production examples K1 and K2 contained less metallic lubricant and more stabilizer compared to production examples J1 and J2, respectively. Production examples K1 and K2 had shorter decomposition times compared to production examples J1 and J2, respectively. This suggests that the lubricant contributes more significantly than the stabilizer to suppressing the decomposition of the mixture.

[0147] Although the present invention has been described above based on embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the description of the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0148] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus and methods shown in the claims, specifications, and drawings is not explicitly stated as "before" or "prior to," and that unless the output of a previous process is used in a later process, the processes can be implemented in any order. Even if the operation flow in the claims, specifications, and drawings is described using terms such as "first" and "next" for convenience, this does not mean that it is mandatory to perform the processes in that order.

[0149] 100 Polymerization apparatus 110 Reaction vessel 120 Stirrer 122 Stirring shaft 124 Stirring blade 126 Power mechanism 130 Baffle 132 Main body 134 Support 140 Serpentine condenser 150 Serpentine condenser 170 Jacket 172 Flow channel 180 Refrigeration condenser 182 Flow channel

Claims

1. A method for producing a calcium carbonate-containing vinyl chloride resin mixture, comprising a mixing or stirring step of mixing a vinyl chloride resin, a calcium carbonate-containing composition derived from calcium-containing waste, and a lubricant to produce a calcium carbonate-containing vinyl chloride resin mixture.

2. The method for producing a calcium carbonate-containing vinyl chloride resin mixture according to claim 1, wherein the lubricant comprises at least one of a metal soap-based lubricant, a fatty acid-based lubricant, a hydrocarbon-based lubricant, an ester-based lubricant, a fatty acid amide-based lubricant, and a silicone-based lubricant.

3. The method for producing a calcium carbonate-containing vinyl chloride resin mixture according to claim 1 or 2, wherein the lubricant is contained in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

4. Chamber volume: 60 cm³ ３ A method for producing a calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 1 to 3, wherein the decomposition time of the calcium carbonate-containing vinyl chloride resin mixture when kneaded using a closed twin-screw kneader at a temperature of 180°C, a rotation speed of 60 rpm, and a filling amount of 72 g is longer than the decomposition time of the calcium carbonate-containing vinyl chloride resin mixture when kneaded at a temperature of 200°C, a rotation speed of 40 rpm, and a filling amount of 67 g.

5. The method for producing a calcium carbonate-containing vinyl chloride resin mixture according to claim 4, wherein the closed twin-screw kneader is a Laboplastmill or a Brabender.

6. A method for producing a calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 1 to 5, wherein the calcium-containing waste includes at least one of concrete waste, limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste.

7. A method for producing a calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 1 to 6, wherein the calcium carbonate-containing composition derived from the calcium-containing waste is used, wherein the calcium carbonate-containing composition derived from the calcium-containing waste contains 10% by mass or more and 80% by mass or less of calcium carbonate derived from the calcium-containing waste.

8. A method for producing a calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 1 to 7, wherein the calcium carbonate-containing composition is contained in an amount of 1 part by weight or more and 250 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

9. A polyvinyl chloride resin mixture containing a polyvinyl chloride resin, a calcium carbonate-containing composition derived from calcium-containing waste, and a lubricant.

10. The calcium carbonate-containing vinyl chloride resin mixture according to claim 9, wherein the lubricant comprises at least one of a metal soap-based lubricant, a fatty acid-based lubricant, a hydrocarbon-based lubricant, an ester-based lubricant, a fatty acid amide-based lubricant, and a silicone-based lubricant.

11. The calcium carbonate-containing vinyl chloride resin mixture according to claim 9 or 10, wherein the lubricant is contained in an amount of 0.1 parts by weight or more and 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

12. The calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 9 to 11, wherein the calcium-containing waste comprises at least one of concrete waste, limestone, marble, seashells, oyster shells, sea urchin shells, chicken eggshells, coral sand, calcium silicate boards, gypsum boards, waste incineration ash, slag, waste concrete, ready-mix concrete sludge, biomass ash, carbide slurry, and livestock waste.

13. The calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 9 to 12, wherein the vinyl chloride resin is a homopolymer or copolymer of polyvinyl chloride.

14. A calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 9 to 13, wherein the calcium carbonate-containing composition is contained in an amount of 1 part by weight or more and 250 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

15. A molded article obtained by injection molding, extrusion molding, press molding or calendering a calcium carbonate-containing vinyl chloride resin mixture according to any one of claims 9 to 14.

Images