Vinyl chloride resin joint

Abstract

To provide a vinyl chloride-based resin joint which can enhance impact resistance.SOLUTION: A vinyl chloride-based resin joint is a vinyl chloride-based resin joint obtained by molding a vinyl chloride-based resin composition containing a vinyl chloride-based resin, polyoxyalkylene glycol and calcium carbonate. In the vinyl chloride-based resin composition, with respect to 100 pts.wt. of the vinyl chloride-based resin, a content of the calcium carbonate is 5 pts.wt. or more and 30 pts.wt. or less and a content of the polyoxyalkylene glycol is 0.005 pts.wt. or more and 0.6 pts.wt. or less. The vinyl chloride-based resin joint contains secondary particles of the calcium carbonate. In the vinyl chloride-based resin joint, an average particle diameter of the secondary particles of the calcium carbonate is 15 μm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a vinyl chloride resin joint using a vinyl chloride resin composition.

Background Art

[0002] Vinyl chloride resins are processed into various molded articles such as joints, pipes, plates, and containers, and are used in many fields. Since the above vinyl chloride resins are excellent in mechanical strength, weather resistance, heat resistance, and chemical resistance, they are particularly preferably used for joints.

[0003] When producing a vinyl chloride resin composition and a vinyl chloride resin joint (vinyl chloride resin molded article), additives such as a stabilizer and a lubricant may be used to improve moldability. However, stabilizers and lubricants are relatively expensive, and there is a problem that the manufacturing cost increases. Therefore, inexpensive calcium carbonate may be used as a filler in order to reduce the manufacturing cost of vinyl chloride resin molded articles and vinyl chloride resin joints (vinyl chloride resin molded articles).

[0004] Patent Document 1 below discloses a vinyl chloride resin composition containing a vinyl chloride resin and cubic calcium carbonate. The above vinyl chloride resin composition preferably contains a plasticizer.

[0005] Patent Document 2 below discloses a rigid polyvinyl chloride molded article containing 100 parts by mass of a polyvinyl chloride resin having an average degree of polymerization of 500 to 1500 and 10 to 40 parts by mass of calcium carbonate. Regarding the above calcium carbonate, the average primary particle diameter is 0.01 μm to 0.3 μm, and the coefficient of variation of the number of particles is 15% or less.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In Patent Documents 1 and 2, by adding calcium carbonate to a vinyl chloride resin composition, the production cost can be reduced to some extent.

[0008] However, since calcium carbonate and vinyl chloride resins have poor compatibility, calcium carbonate particles pulverized by mixing with vinyl chloride resins are difficult to disperse uniformly in the vinyl chloride resin composition, and there is a problem that they aggregate in the composition or during molding to form secondary particles. If there are secondary particles of calcium carbonate in a vinyl chloride resin molded body, depending on the state of existence of the secondary particles, when an impact such as dropping is applied to the vinyl chloride resin molded body, cracks may occur starting from the secondary particles of calcium carbonate. That is, there is a problem that the impact resistance of the obtained vinyl chloride resin molded body is lowered. These problems are more prominent in injection molding, which has lower kneading ability than extrusion molding and a more complex shape of the molded body.

[0009] Furthermore, in the vinyl chloride resin composition described in Patent Document 1, there is a problem that the heat resistance and impact resistance of the vinyl chloride resin composition are further lowered by the plasticizer.

[0010] Also, in Patent Document 2, since the particle diameter of calcium carbonate in the vinyl chloride resin composition is too small, calcium carbonate is more likely to aggregate, and secondary particles of calcium carbonate are more likely to be formed. As a result, there is a problem that the appearance and impact resistance of the vinyl chloride resin molded body are more likely to deteriorate.

[0011] An object of the present invention is to provide a vinyl chloride resin joint capable of enhancing impact resistance.

Means for Solving the Problems

[0012] According to a broad aspect of the present invention, there is provided a vinyl chloride resin joint formed from a vinyl chloride resin composition containing a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate. In the vinyl chloride resin composition, the content of the calcium carbonate is 5 parts by weight or more and 30 parts by weight or less, and the content of the polyoxyalkylene glycol is 0.005 parts by weight or more and 0.60 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin. The vinyl chloride resin joint contains secondary particles of the calcium carbonate, and in the vinyl chloride resin joint, the average particle diameter of the secondary particles of the calcium carbonate is 15 μm or less.

[0013] In a specific aspect of the vinyl chloride resin joint according to the present invention, the polyoxyalkylene glycol is polyoxypropylene glycol.

[0014] In a specific aspect of the vinyl chloride resin joint according to the present invention, in the vinyl chloride resin composition, the content of the polyoxyalkylene glycol is 0.1 parts by weight or more and 2.0 parts by weight or less, based on 100 parts by weight of the calcium carbonate.

[0015] In a specific aspect of the vinyl chloride resin joint according to the present invention, the vinyl chloride resin composition contains an organotin-based stabilizer.

[0016] In a specific aspect of the vinyl chloride resin joint according to the present invention, the vinyl chloride resin joint is an injection molded article of the vinyl chloride resin composition.

Advantages of the Invention

[0017] The vinyl chloride resin joint according to the present invention is a vinyl chloride resin joint formed from a vinyl chloride resin composition containing a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate. In the vinyl chloride resin joint according to the present invention, in the above vinyl chloride resin composition, the content of the above calcium carbonate is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the above vinyl chloride resin, and the content of the above polyoxyalkylene glycol is 0.005 parts by weight or more and 0.60 parts by weight or less. The vinyl chloride resin joint according to the present invention contains secondary particles of the above calcium carbonate. In the vinyl chloride resin joint according to the present invention, the average particle diameter of the secondary particles of the above calcium carbonate is 15 μm or less. Since the above configuration is provided in the vinyl chloride resin joint according to the present invention, the impact resistance can be enhanced.

Mode for Carrying Out the Invention

[0018] Hereinafter, the present invention will be described in detail.

[0019] The vinyl chloride resin joint according to the present invention is a vinyl chloride resin joint formed from a vinyl chloride resin composition containing a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate. In the vinyl chloride resin joint according to the present invention, in the above vinyl chloride resin composition, the content of the above calcium carbonate is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the above vinyl chloride resin, and the content of the above polyoxyalkylene glycol is 0.005 parts by weight or more and 0.60 parts by weight or less.

[0020] The vinyl chloride resin joint according to the present invention contains secondary particles of the above calcium carbonate. In the vinyl chloride resin joint according to the present invention, the average particle diameter of the secondary particles of the above calcium carbonate is 15 μm or less.

[0021] In the vinyl chloride resin joint according to the present invention, since the above configuration is provided, the impact resistance can be enhanced. Further, in the vinyl chloride resin joint according to the present invention, since calcium carbonate is contained in a specific content, the manufacturing cost can be reduced.

[0022] In addition, since the vinyl chloride resin joint according to the present invention is obtained by molding the above vinyl chloride resin composition, it contains a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate. In the vinyl chloride resin joint according to the present invention, the content of the calcium carbonate is preferably 5 parts by weight or more and 30 parts by weight or less, and the content of the polyoxyalkylene glycol is preferably 0.005 parts by weight or more and 0.60 parts by weight or less with respect to 100 parts by weight of the above vinyl chloride resin.

[0023] The above vinyl chloride resin joint is a molded body of the above base vinyl resin composition. The above vinyl chloride resin joint is preferably an injection molded body of the above vinyl chloride resin composition.

[0024] The above vinyl chloride resin composition is used to obtain a vinyl chloride resin joint. The above vinyl chloride resin composition is preferably used suitably to obtain an injection type vinyl chloride resin joint. The above vinyl chloride resin composition is preferably injection molded. The above vinyl chloride resin composition is preferably an injection molding vinyl chloride resin composition.

[0025] (Vinyl chloride resin composition) The above vinyl chloride resin composition contains a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate.

[0026] In this specification, one non-aggregated calcium carbonate in the material of the above vinyl chloride resin composition is defined as a primary particle of calcium carbonate. The pulverized product obtained by pulverizing the primary particles of the above calcium carbonate is defined as the pulverized particles of calcium carbonate. The aggregate in which two or more of the primary particles or pulverized particles of the above calcium carbonate are aggregated is defined as the secondary particles of calcium carbonate.

[0027] Hereinafter, each component and the like contained in the above vinyl chloride resin composition will be described. In the following description of the vinyl chloride resin composition, the above vinyl chloride resin joint may also be described together.

[0028] In addition, in this specification, “(meth)acryl” means one or both of “acryl” and “methacryl”, and “(meth)acrylate” means one or both of “acrylate” and “methacrylate”.

[0029] <Vinyl chloride resin> The above vinyl chloride resin has a chlorine atom. The above vinyl chloride resin may be a chlorinated vinyl chloride resin, a non-chlorinated vinyl chloride resin, or a mixture of a chlorinated vinyl chloride resin and a non-chlorinated vinyl chloride resin. From the viewpoint of enhancing flame retardancy and heat resistance to deformation, the above vinyl chloride resin is preferably a chlorinated vinyl chloride resin. The above chlorinated vinyl chloride resin is a resin obtained by chlorinating a vinyl chloride resin. Only one kind of the above vinyl chloride resin may be used, or two or more kinds may be used in combination.

[0030] Examples of the above vinyl chloride resin include a homopolymer of a vinyl chloride monomer and a copolymer of a vinyl chloride monomer and a vinyl monomer copolymerizable with the vinyl chloride monomer.

[0031] Examples of the vinyl monomer copolymerizable with the above vinyl chloride monomer include vinyl esters such as vinyl acetate, vinyl propionate, and vinyl ether; cyano group-containing compounds such as acrylonitrile; halogen compounds such as vinylidene chloride and vinyl fluoride; olefins such as ethylene and propylene; carboxyl group-containing compounds such as itaconic acid, maleic acid, and fumaric acid; non-aromatic carboxylic acid anhydrides such as maleic anhydride; (meth)acrylate esters such as methyl (meth)acrylate and ethyl (meth)acrylate; and imide compounds such as maleimide. Only one kind of the above vinyl monomer may be used, or two or more kinds may be used in combination.

[0032] The polymerization method of the above vinyl chloride monomer or the polymerization method of the above vinyl chloride monomer and a vinyl monomer copolymerizable with the above vinyl chloride monomer is not particularly limited. Examples of the above polymerization method include suspension polymerization method, emulsion polymerization method, solution polymerization method, bulk polymerization method, and precipitation polymerization method. From the viewpoint of efficiently obtaining a vinyl chloride resin, the above polymerization method is preferably a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, or a precipitation polymerization method.

[0033] The above chlorinated vinyl chloride resin is preferably obtained by polymerizing the above vinyl chloride monomer or the above vinyl chloride monomer and the above vinyl monomer to obtain a vinyl chloride resin and then chlorinating the vinyl chloride resin.

[0034] The method for chlorinating the above vinyl chloride resin is not particularly limited. Examples of the method for chlorinating the above vinyl chloride resin include a method in which the vinyl chloride resin is put into an aqueous solvent to obtain a suspension and then chlorine is added to react the vinyl chloride resin with chlorine. This chlorination reaction proceeds under heating conditions or light irradiation conditions.

[0035] From the viewpoint of enhancing the thermal stability of the obtained chlorinated vinyl chloride resin, the above chlorination reaction is preferably carried out under heating conditions.

[0036] From the viewpoint of enhancing the efficiency of the chlorination reaction, the temperature during the above heating is preferably 80 °C or higher and preferably 140 °C or lower.

[0037] The degree of polymerization of the above vinyl chloride resin is preferably 500 or more, more preferably 600 or more, preferably 2000 or less, more preferably 1100 or less, and even more preferably 1000 or less. When the degree of polymerization is at least the above lower limit, the durability of the vinyl chloride resin joint can be enhanced and the impact resistance can be further enhanced. When the degree of polymerization is at most the above upper limit, the melt viscosity of the above vinyl chloride resin and the above vinyl chloride resin composition can be lowered, so that the fluidity during molding can be enhanced.

[0038] In 100% by weight of the above vinyl chloride resin composition and in 100% by weight of the above vinyl chloride resin joint, the content of the above vinyl chloride resin is preferably 85% by weight or more, more preferably 87% by weight or more, still more preferably 90% by weight or more, and preferably 95% by weight or less, more preferably 92% by weight or less, still more preferably 91% by weight or less. When the content of the above vinyl chloride resin is at least the above lower limit, the adhesive strength of the vinyl chloride resin joint can be increased, and the impact resistance can be further enhanced. When the content of the above vinyl chloride resin is at most the above upper limit, it is not necessary to raise the temperature during molding, and the moldability can be improved.

[0039] The vinyl chloride resin contained in the above vinyl chloride resin composition is preferably in the form of particles. The particle diameter of the vinyl chloride resin in the form of particles is preferably 0.1 μm or more and preferably 500 μm or less. When the above particle diameter is at least the above lower limit, the handleability can be enhanced. When the above particle diameter is at most the above upper limit, the moldability can be improved.

[0040] The particle diameter of the above vinyl chloride resin is preferably the average particle diameter, and preferably the volume average particle diameter. The volume average particle diameter of the above vinyl chloride resin is the average diameter measured on a volume basis and is the value of the median diameter (D50) at which it becomes 50%. The above volume average particle diameter can be measured by a laser diffraction / scattering method or the like.

[0041] <Polyoxyalkylene glycol> By using the above polyoxyalkylene glycol in combination with calcium carbonate, the primary particles and pulverized particles of the above calcium carbonate can be uniformly dispersed in the above vinyl chloride resin composition and the above vinyl chloride resin joint, and the formation of secondary particles of the above calcium carbonate can be suppressed.

[0042] Examples of the polyoxyalkylene glycol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, and polyoxyethylene-polyoxypropylene copolymer. Only one type of the polyoxyalkylene glycol may be used, or two or more types may be used.

[0043] From the viewpoint of improving the appearance of the vinyl chloride resin joint and further enhancing the impact resistance by suppressing the formation of secondary particles of calcium carbonate, the polyoxyalkylene glycol is preferably polyoxyethylene glycol or polyoxypropylene glycol, and more preferably polyoxypropylene glycol.

[0044] From the viewpoint of improving the appearance of the vinyl chloride resin joint and further enhancing the impact resistance by suppressing the formation of secondary particles of calcium carbonate, the number of carbon atoms of the alkylene group in the polyoxyalkylene glycol is preferably 2 or more and preferably 4 or less. The alkylene group in the polyoxyalkylene glycol may be only one type or two or more types.

[0045] The alkylene group in the polyoxyalkylene glycol may or may not have a side chain. Examples of the side chain include a methyl group, an ethyl group, a propyl group, and a butyl group. The side chain of the alkylene group in the polyoxyalkylene glycol may be only one type or two or more types.

[0046] From the viewpoint of more uniformly dispersing the primary particles and pulverized particles of calcium carbonate in the vinyl chloride resin composition and the vinyl chloride resin joint and further suppressing the formation of secondary particles of calcium carbonate, the polyoxyalkylene glycol preferably has a carboxy group at the terminal, and more preferably has carboxy groups at both terminals.

[0047] The molecular weight of the above polyoxyalkylene glycol is preferably 100 or more, more preferably 2000 or more, still more preferably 3000 or more, and preferably 10000 or less, more preferably 8000 or less, still more preferably 6000 or less. When the molecular weight of the above polyoxyalkylene glycol is not less than the above lower limit and not more than the above upper limit, the formation of secondary particles of the above calcium carbonate can be suppressed, thereby improving the appearance of the above vinyl chloride resin joint and further enhancing the impact resistance. The above molecular weight is preferably the number average molecular weight.

[0048] The molecular weight of the above polyoxyalkylene glycol means the molecular weight calculated from the structural formula when the structural formula of the above polyoxyalkylene glycol can be specified. When the above polyoxyalkylene glycol is a polymer or the like whose structural formula cannot be specified, it means the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0049] In the above vinyl chloride resin composition, the content of the polyoxyalkylene glycol is 0.005 parts by weight or more and 0.60 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. Further, in the above vinyl chloride resin joint, the content of the polyoxyalkylene glycol is preferably 0.005 parts by weight or more and preferably 0.60 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. In each of the above vinyl chloride resin composition and the above vinyl chloride resin joint, the content of the polyoxyalkylene glycol is preferably 0.02 parts by weight or more, more preferably 0.05 parts by weight or more, preferably 0.50 parts by weight or less, and more preferably 0.40 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. When the content of the polyoxyalkylene glycol is at least the above lower limit, the primary particles and pulverized particles of the calcium carbonate can be more uniformly dispersed in the above vinyl chloride resin composition and the above vinyl chloride resin joint, and the formation of secondary particles of the calcium carbonate can be suppressed. As a result, the appearance of the vinyl chloride resin joint can be improved, and the impact resistance can be further enhanced. When the content of the polyoxyalkylene glycol is at most the above upper limit, the polyoxyalkylene glycol present between the pulverized particles of the calcium carbonate is difficult to be removed, and the aggregation of the pulverized particles of the calcium carbonate can be prevented, so that the formation of secondary particles of the calcium carbonate can be suppressed. As a result, the appearance of the vinyl chloride resin joint can be further improved, and the impact resistance can be further enhanced.

[0050] In each of the above vinyl chloride resin composition and the above vinyl chloride resin joint, with respect to 100 parts by weight of the above calcium carbonate, the content of the above polyoxyalkylene glycol is preferably 0.1 part by weight or more, more preferably 0.5 part by weight or more, and still more preferably 1.0 part by weight or more. In each of the above vinyl chloride resin composition and the above vinyl chloride resin joint, with respect to 100 parts by weight of the above calcium carbonate, the content of the above polyoxyalkylene glycol is preferably 2.0 parts by weight or less, more preferably 1.8 parts by weight or less, and still more preferably 1.3 parts by weight or less. When the content of the above polyoxyalkylene glycol is at least the above lower limit, the primary particles and pulverized particles of the above calcium carbonate can be uniformly dispersed in the above vinyl chloride resin composition and the above vinyl chloride resin joint, and the formation of secondary particles of the above calcium carbonate can be suppressed. As a result, the appearance of the vinyl chloride resin joint can be improved, and the impact resistance can be further enhanced. When the content of the above polyoxyalkylene glycol is at most the above upper limit, the polyoxyalkylene glycol present between the pulverized particles of the above calcium carbonate is difficult to be eliminated, and the aggregation of the pulverized particles of the above calcium carbonate can be prevented, so the formation of secondary particles of the above calcium carbonate can be suppressed. As a result, the appearance of the vinyl chloride resin joint can be improved, and the impact resistance can be further enhanced.

[0051] <Calcium carbonate> In the above vinyl chloride resin composition and the above vinyl chloride resin joint, the above calcium carbonate acts as a filler.

[0052] In the material of the above vinyl chloride resin composition, it is preferable that the calcium carbonate exists as primary particles. The primary particles of the calcium carbonate may be pulverized into two or more particles by mixing with a vinyl chloride resin or the like during the preparation of the vinyl chloride resin composition to become pulverized particles. The pulverized particles of the calcium carbonate are formed by pulverizing the primary particles of the calcium carbonate. The primary particles and pulverized particles of the calcium carbonate may aggregate in the vinyl chloride resin composition and during molding to form secondary particles. The secondary particles of the calcium carbonate are formed by two or more primary particles or pulverized particles of the calcium carbonate. The secondary particles of the calcium carbonate may be formed only by the primary particles of the calcium carbonate, may be formed only by the pulverized particles of the calcium carbonate, or may be formed by a combination of the primary particles and pulverized particles of the calcium carbonate.

[0053] The above vinyl chloride resin composition may contain the primary particles of the calcium carbonate, may contain the pulverized particles of the calcium carbonate, or may contain the primary particles and pulverized particles of the calcium carbonate. It is preferable that the vinyl chloride resin composition contains the pulverized particles of the calcium carbonate. The calcium carbonate in the vinyl chloride resin composition is preferably the pulverized particles of the calcium carbonate. In the vinyl chloride resin composition, the calcium carbonate particles preferably exist as pulverized particles. In addition, it is preferable that the calcium carbonate is not aggregated in the vinyl chloride resin composition. It is preferable that the vinyl chloride resin composition does not contain the secondary particles of the calcium carbonate.

[0054] From the viewpoint of more effectively exerting the effects of the present invention, the particle diameter (primary particle diameter) of the primary particles of the calcium carbonate is preferably 0.5 μm or more, more preferably 0.8 μm or more, still more preferably 1.0 μm or more, and preferably 10 μm or less, more preferably 5.0 μm or less, still more preferably 3.0 μm or less.

[0055] From the viewpoint of more effectively exerting the effects of the present invention, the particle diameter (ground particle diameter) of the ground particles of the calcium carbonate is preferably 0.1 μm or more, more preferably 0.2 μm or more, still more preferably 0.5 μm or more, and preferably 5.0 μm or less, more preferably 3.0 μm or less, still more preferably 2.0 μm or less.

[0056] From the viewpoint of more effectively exerting the effects of the present invention, the particle diameter (secondary particle diameter) of the secondary particles of the calcium carbonate in the vinyl chloride resin composition is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1.5 μm or more, and preferably 15 μm or less, more preferably 14 μm or less, still more preferably 10 μm or less.

[0057] The primary particle diameter, ground particle diameter, and secondary particle diameter of the calcium carbonate are preferably average particle diameters, and more preferably number average particle diameters. The particle diameter of the calcium carbonate can be determined, for example, by observing 50 arbitrary calcium carbonates with an electron microscope or an optical microscope and calculating the average value of the particle diameters of each calcium carbonate, or by using a particle size distribution measuring device. In the observation with an electron microscope or an optical microscope, the particle diameter of each calcium carbonate is determined as the particle diameter equivalent to a circle. In the observation with an electron microscope or an optical microscope, the average particle diameter in terms of the circle equivalent diameter of 50 arbitrary calcium carbonates is almost equal to the average particle diameter in terms of the sphere equivalent diameter. In the particle size distribution measuring device, the particle diameter of each calcium carbonate is determined as the particle diameter equivalent to a sphere. The average particle diameter of the calcium carbonate is preferably calculated using a particle size distribution measuring device.

[0058] The primary particles, pulverized particles, and secondary particles of the calcium carbonate may be spherical, may have a shape other than spherical, and may have a shape such as square columnar, cylindrical, and flat. From the viewpoint of improving the appearance of the vinyl chloride resin joint and further enhancing the impact resistance by suppressing the formation of secondary particles of calcium carbonate, the shapes of the primary particles, pulverized particles, and secondary particles of the calcium carbonate are preferably spherical. The aspect ratio of the primary particles, pulverized particles, and secondary particles of the calcium carbonate is preferably 2.0 or less, more preferably 1.5 or less, and still more preferably 1.2 or less.

[0059] In the vinyl chloride resin composition, the content of the calcium carbonate is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. In the vinyl chloride resin joint, the content of the calcium carbonate is preferably 5 parts by weight or more and preferably 30 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. In the present invention, since the above configuration is provided, the fluidity during molding can be increased, and the appearance of the vinyl chloride resin joint can be improved. Further, the manufacturing costs of the vinyl chloride resin composition and the vinyl chloride resin joint can be reduced. In each of the vinyl chloride resin composition and the vinyl chloride resin joint, the content of the calcium carbonate is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 15 parts by weight or less, and more preferably 20 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. When the content of the calcium carbonate is equal to or higher than the lower limit and equal to or lower than the upper limit, the manufacturing cost can be reduced, and the effects of the present invention can be more effectively exhibited.

[0060] <Other components> Various additives may be used in the vinyl chloride resin composition and the vinyl chloride resin joint as needed. Examples of the additives include stabilizers, heat stabilization aids, lubricants, impact modifiers, heat resistance improvers, antioxidants, ultraviolet absorbers, antistatic agents, light stabilizers, pigments, flame retardants, and plasticizers. Only one kind of the additives may be used, or two or more kinds may be used in combination.

[0061] The above vinyl chloride resin composition and the above vinyl chloride resin joint preferably contain a stabilizer. Examples of the above heat stabilizer include organotin stabilizers, lead stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, and barium-cadmium stabilizers. Only one kind of the above stabilizer may be used, or two or more kinds may be used in combination.

[0062] The above stabilizer is preferably a heat stabilizer.

[0063] From the viewpoint of suppressing the decomposition of the vinyl chloride resin and capturing hydrochloric acid generated during the decomposition of the vinyl chloride resin, the above vinyl chloride resin composition and the above vinyl chloride resin joint preferably contain an organotin stabilizer, and more preferably contain an organotin heat stabilizer. Further, by using an organotin stabilizer, the appearance of the above vinyl chloride resin joint becomes even better.

[0064] Examples of the above organotin stabilizer include tin mercapto stabilizers, tin maleate stabilizers, and tin carboxylate stabilizers. Examples of the above tin mercapto stabilizer include monoalkyltin mercapto, dialkyltin mercapto, monoalkyltin mercapto polymer, dialkyltin mercapto polymer, monoalkyltin mercapto sulfide, and dialkyltin mercapto sulfide. Examples of the above tin maleate stabilizer include monoalkyltin maleate, dialkyltin maleate, monoalkyltin maleate polymer, and dialkyltin maleate polymer. Examples of the above tin carboxylate stabilizer include monoalkyltin carboxylate and dialkyltin carboxylate. Only one kind of the above organotin stabilizer may be used, or two or more kinds may be used in combination.

[0065] From the viewpoint of improving the heat stability, the above organotin stabilizer is preferably a tin mercapto stabilizer, preferably dialkyltin mercapto, and more preferably dioctyltin mercapto.

[0066] Examples of the lead stabilizer include tribasic lead sulfate, tetrabasic lead sulfate, basic lead sulfite, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, dibasic lead stearate, and basic lead sulfite phosphite.

[0067] In each of the vinyl chloride resin composition and the vinyl chloride resin joint, the content of the organotin stabilizer is preferably 0.2 parts by weight or more, more preferably 0.3 parts by weight or more, and still more preferably 0.5 parts by weight or more, based on 100 parts by weight of the vinyl chloride resin. In each of the vinyl chloride resin composition and the vinyl chloride resin joint, the content of the organotin stabilizer is preferably 3.0 parts by weight or less, more preferably 2.0 parts by weight or less, and still more preferably 1.8 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin. When the content of the organotin stabilizer is not less than the lower limit and not more than the upper limit, the thermal stability can be enhanced, and the heat resistance of the vinyl chloride resin joint can be enhanced.

[0068] The heat stabilizer aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, and zeolite. Only one kind of the heat stabilizer aid may be used, or two or more kinds may be used in combination.

[0069] The vinyl chloride resin composition and the vinyl chloride resin joint may or may not contain a lubricant. It is preferable that the vinyl chloride resin composition and the vinyl chloride resin joint contain a lubricant.

[0070] Examples of the lubricant include an internal lubricant and an external lubricant. The internal lubricant is used for the purpose of reducing the melt viscosity of the molten resin during the molding process and preventing frictional heat generation. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. The external lubricant is used for the purpose of enhancing the sliding effect between the molten resin and the metal surface (mold) during the molding process. The external lubricant is not particularly limited, and examples thereof include polyethylene-based lubricants, ester-based lubricants, paraffin wax, polyolefin wax, and montanic acid wax. Only one kind of the lubricant may be used, or two or more kinds may be used in combination.

[0071] From the viewpoint of improving the sliding between the vinyl chloride-based resin composition and the metal surface (mold) during molding, it is preferable that the vinyl chloride-based resin composition and the vinyl chloride-based resin joint contain a polyethylene-based lubricant, and it is more preferable that they contain a polyethylene-based lubricant and an ester-based lubricant.

[0072] When the vinyl chloride-based resin composition and the vinyl chloride-based resin joint contain the polyethylene-based lubricant, it is preferable to satisfy the following content. With respect to 100 parts by weight of the vinyl chloride-based resin, the content of the polyethylene-based lubricant is preferably more than 0 part by weight, more preferably 0.1 part by weight or more, still more preferably 0.5 part by weight or more, preferably 10 parts by weight or less, more preferably 2 parts by weight or less, and still more preferably 1 part by weight or less. When the content of the polyethylene-based lubricant satisfies the above lower limit and upper limit, the primary particles and pulverized particles of the calcium carbonate can be uniformly dispersed in the vinyl chloride-based resin composition and the vinyl chloride-based resin joint, and the formation of secondary particles of the calcium carbonate can be suppressed. As a result, the fluidity during molding can be increased, and the appearance of the vinyl chloride-based resin joint can be improved. In addition, the sliding between the vinyl chloride-based resin composition and the metal surface (mold) during molding can be improved, and the appearance of the vinyl chloride-based resin joint can be improved.

[0073] The above vinyl chloride resin composition and the above vinyl chloride resin joint may contain the above polyethylene-based lubricant and a lubricant other than the above polyethylene-based lubricant.

[0074] When the above vinyl chloride resin composition and the above vinyl chloride resin joint contain the above polyethylene-based lubricant and a lubricant other than the above polyethylene-based lubricant, it is preferable to satisfy the following content. With respect to 100 parts by weight of the above vinyl chloride resin, the total content of the above polyethylene-based lubricant and a lubricant other than the above polyethylene-based lubricant (total content of lubricants) is preferably more than 0 part by weight, more preferably 0.2 part by weight or more, still more preferably 0.4 part by weight or more, preferably 1.5 part by weight or less, and more preferably 0.6 part by weight or less. When the total content of the above polyethylene-based lubricant and a lubricant other than the above polyethylene-based lubricant satisfies the above lower limit and the above upper limit, the primary particles and pulverized particles of the above calcium carbonate can be uniformly dispersed in the above vinyl chloride resin composition and the above vinyl chloride resin joint. As a result, the fluidity during molding can be enhanced, and the appearance of the above vinyl chloride resin joint can be improved. Further, the slipperiness between the vinyl chloride resin composition and the metal surface (mold) during molding can be improved, and the appearance of the above vinyl chloride resin joint can be improved.

[0075] The above impact modifier is not particularly limited, and examples thereof include methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, and acrylic rubber. Only one kind of the above impact modifier may be used, or two or more kinds may be used in combination.

[0076] The above heat resistance improver is not particularly limited, and examples thereof include α-methylstyrene-based and N-phenylmaleimide-based resins. Only one kind of the above heat resistance improver may be used, or two or more kinds may be used in combination.

[0077] The above antioxidant is not particularly limited, and examples thereof include phenolic antioxidants. Only one kind of the above antioxidant may be used, or two or more kinds may be used in combination.

[0078] The above ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. Only one kind of the above ultraviolet absorber may be used, or two or more kinds may be used in combination.

[0079] The above light stabilizer is not particularly limited, and examples thereof include hindered amine-based light stabilizers. Only one kind of the above light stabilizer may be used, or two or more kinds may be used in combination.

[0080] The above pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments. Examples of the above organic pigments include azo-based organic pigments, phthalocyanine-based organic pigments, perylene-based organic pigments, and dye lake-based organic pigments. Examples of the above inorganic pigments include oxide-based inorganic pigments, molybdenum chromate-based inorganic pigments, sulfide / selenide-based inorganic pigments, and ferrocyanide-based inorganic pigments. From the viewpoint of further enhancing transparency, it is preferable that the above vinyl chloride-based resin composition does not contain the above pigment.

[0081] The above plasticizer may be added for the purpose of enhancing the processability during molding. Since the heat resistance of the molded product may decrease due to the addition of the plasticizer, it is preferable that the addition amount of the plasticizer is small. The above plasticizer is not particularly limited, and examples thereof include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. Only one kind of the above plasticizer may be used, or two or more kinds may be used in combination.

[0082] (Other details of the vinyl chloride-based resin joint) The above vinyl chloride resin joint is formed using the above vinyl chloride resin composition. The above vinyl chloride resin composition can be used to obtain the above vinyl chloride resin joint. The above vinyl chloride resin joint is obtained by molding the above vinyl chloride resin composition. The above vinyl chloride resin joint is a molded body of the above vinyl chloride resin composition. The above vinyl chloride resin joint is preferably an injection molded body of the above vinyl chloride resin composition.

[0083] In the above vinyl chloride resin joint, the primary particles and pulverized particles of the above calcium carbonate can be uniformly dispersed. As a result, the appearance of the above vinyl chloride resin joint can be improved.

[0084] Note that some of the primary particles and pulverized particles of the above calcium carbonate in the above vinyl chloride resin composition may aggregate in the composition or during molding. In the above vinyl chloride resin joint, some of the primary particles or pulverized particles of the above calcium carbonate are aggregated. The above vinyl chloride resin joint (molded body of the vinyl chloride resin composition) contains secondary particles of the above calcium carbonate. In the above vinyl chloride resin joint, the primary particles, pulverized particles and secondary particles of the above calcium carbonate may be present. The above vinyl chloride resin joint may contain only the secondary particles of the above calcium carbonate, may contain primary particles and secondary particles, may contain pulverized particles and secondary particles, or may contain primary particles, pulverized particles and secondary particles.

[0085] In the above vinyl chloride resin joint, the particle diameter (secondary particle diameter) of the secondary particles of the above calcium carbonate is 15 μm or less. The particle diameter of the secondary particles of the above calcium carbonate in the above vinyl chloride resin joint is preferably 1.0 μm or more, more preferably 1.5 μm or more, still more preferably 2.0 μm or more, preferably 13 μm or less, more preferably 10 μm or less, still more preferably 8.0 μm or less, and particularly preferably 5.0 μm or less. When the particle diameter of the secondary particles of the above calcium carbonate is not less than the above lower limit and not more than the above upper limit, the appearance of the above vinyl chloride resin joint can be improved, and the impact resistance can be further enhanced.

[0086] The particle diameter of the secondary particles of the calcium carbonate is preferably the number average particle diameter. The particle diameter of the secondary particles of the calcium carbonate can be measured, for example, by the following method. The vinyl chloride resin joint is cut using a diamond cutter, and the cross section is observed with a scanning electron microscope. Using image analysis software, the average value of the particle diameters of the secondary particles of calcium carbonate present in a unit area is determined. Examples of the diamond cutter include "Marunoko Machine Model 2711" manufactured by Makita Corporation.

[0087] For example, when one secondary particle is composed of three primary particles of calcium carbonate, in this secondary particle, the number of the primary particles of calcium carbonate that form the secondary particle is counted as 3. For example, when one secondary particle is composed of three pulverized particles of calcium carbonate, in this secondary particle, the number of the pulverized particles of calcium carbonate that form the secondary particle is counted as 3.

[0088] The mixing method of the vinyl chloride resin composition and the materials of the vinyl chloride resin joint is not particularly limited. The vinyl chloride resin composition and the materials of the vinyl chloride resin joint may be mixed all at once, or a plurality of materials may be mixed in advance. In the manufacturing method of the vinyl chloride resin composition and the vinyl chloride resin joint, it is preferable that the calcium carbonate (primary particles) and the polyoxyalkylene glycol are mixed in advance. When the calcium carbonate and the polyoxyalkylene glycol are mixed in advance, the polyoxyalkylene glycol is dispersed on the surface of the calcium carbonate, and aggregation of the primary particles and pulverized particles of the calcium carbonate can be prevented. As a result, formation of the secondary particles of calcium carbonate in the vinyl chloride resin composition and during molding can be suppressed, so that the appearance of the vinyl chloride resin joint can be improved, and the impact resistance can be further enhanced. The calcium carbonate and the polyoxyalkylene glycol can be mixed, for example, using a mixer.

[0089] The above vinyl chloride resin joint may be a single-layer joint or a multi-layer joint.

[0090] The method for molding the above vinyl chloride resin composition is not particularly limited, and examples thereof include an extrusion molding method, an injection molding method, a calender molding method, and a press molding method. From the viewpoint of enhancing the fluidity during molding, the molding method of the above vinyl chloride resin composition is preferably an injection molding method.

[0091] The above vinyl chloride resin joint is preferably an injection molded article.

[0092] The molding machine used for molding is not particularly limited, and examples thereof include a screw type injection molding machine, a single-screw extruder, a twin-screw non-directional parallel extruder, a twin-screw non-directional conical extruder, and a twin-screw co-directional extruder. When molding using the above molding machine, the shaping die, resin temperature, etc. are not particularly limited.

[0093] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited only to the following examples.

[0094] The following materials were prepared.

[0095] (Vinyl chloride resin) Vinyl chloride resin ("TS-800" manufactured by Taiyo Vinyl Co., polymerization degree: 800)

[0096] (Polyoxyalkylene glycol) Polyoxypropylene glycol ("DISPERPLAST-1180" manufactured by BYK, molecular weight: 3.2×10 3 )

[0097] (Calcium carbonate) Calcium carbonate ("Super #1700" manufactured by Maruo Calcium Co., average particle diameter of primary particles: 1.9 μm)

[0098] (Lubricant) Polyethylene-based lubricant (manufactured by Mitsui Chemicals, Inc., "HW2203A", acid value: 30) Ester-based lubricant (manufactured by Emery Oleochemicals, "G15")

[0099] (Stabilizer) Organotin-based stabilizer (manufactured by Katsuta Chemical Co., Ltd., "KM-19D-2")

[0100] (Example 1) 10 parts by weight of calcium carbonate and 0.15 parts by weight of polyoxypropylene glycol were added to a small crusher (Rotary Crusher NR-04A type manufactured by Sanjo Industries Co., Ltd.) and mixed at 30,000 rpm for 5 minutes to obtain a premixed composition. In the premixed composition, crushed particles of calcium carbonate were formed. The obtained premixed composition, 100 parts by weight of a vinyl chloride-based resin, 1.6 parts by weight of an organotin-based stabilizer, 0.5 parts by weight of a polyethylene-based lubricant, and 0.5 parts by weight of an ester-based lubricant were added to a rotary mixer ("20L Super Mixer" manufactured by Kawata Co., Ltd.). Then, steam was introduced and rotation mixing was carried out at 1500 rpm, and the temperature was raised to 105°C. After that, the steam was stopped, cooling water was passed through and rotation mixing was carried out, and it was cooled to room temperature (23°C) to obtain a vinyl chloride-based resin composition.

[0101] For the obtained vinyl chloride-based resin composition, a vinyl chloride-based resin joint (injection molded body) was produced in accordance with JIS K6743 using a screw-type injection molding machine ("350t injection molding machine" manufactured by JSW Co., Ltd.) and a joint mold. The obtained vinyl chloride-based resin joint had a length of 133 mm, a diameter of 50 mm, and a thickness of 5.0 ± 0.4 mm. In the vinyl chloride-based resin joint, secondary particles of calcium carbonate were formed.

[0102] (Examples 2 to 5 and Comparative Examples 1 to 8) A vinyl chloride-based resin composition and a vinyl chloride-based resin joint were produced in the same manner as in Example 1, except that the types and amounts of the compounding components were as shown in Tables 1 to 2 below.

[0103] (Evaluation) (1) Average particle diameter of secondary particles of calcium carbonate The obtained vinyl chloride resin joint was cut into pieces with a length of 3 mm using a diamond cutter (Makita's "Marunoko Disk Model 2711"), and the cross-section was observed using a scanning electron microscope (JEOL's "JSM-6510A"). Using image analysis software (ImageJ), the average value of the equivalent circle diameter of the secondary particles of calcium carbonate present in any 1 cm 2 was determined and taken as the average particle diameter of the secondary particles.

[0104] (2) Impact resistance Regarding the obtained vinyl chloride resin joint, using a falling weight tester (Nidec-Shimpo's "TS-001") and a flat-bottomed weight with a mass of 3 kg, the 50% impact fracture height was calculated in accordance with Appendix JA of JIS K6743. The impact resistance was judged according to the following criteria.

[0105] [Judgment criteria for impact resistance] ○○: The 50% impact fracture height is 80 cm or more ○: The 50% impact fracture height is 50 cm or more and less than 80 cm ×: The 50% impact fracture height is less than 50 cm

[0106] The compounding composition and results are shown in Tables 1 to 2 below.

[0107]

Table 1

[0108]

Table 2

Claims

1. A vinyl chloride resin joint formed from a vinyl chloride resin composition containing a vinyl chloride resin, a polyoxyalkylene glycol, and calcium carbonate, wherein in the vinyl chloride resin composition, the content of the calcium carbonate is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin, and the content of the polyoxyalkylene glycol is 0.005 parts by weight or more and 0.60 parts by weight or less, the polyoxyalkylene glycol has carboxy groups at both ends, the vinyl chloride resin joint contains secondary particles of the calcium carbonate, and in observation of a cross section of the vinyl chloride resin joint by a scanning electron microscope, the average value of the equivalent circle diameter of the secondary particles of the calcium carbonate is 15 μm or less.

2. The vinyl chloride resin joint according to claim 1, wherein the polyoxyalkylene glycol is polyoxypropylene glycol.

3. The vinyl chloride resin joint according to claim 1 or 2, wherein in the vinyl chloride resin composition, the content of the polyoxyalkylene glycol is 0.1 parts by weight or more and 2.0 parts by weight or less with respect to 100 parts by weight of the calcium carbonate.

4. The vinyl chloride resin joint according to any one of claims 1 to 3, wherein the vinyl chloride resin composition contains an organotin-based stabilizer.

5. The vinyl chloride resin joint according to any one of claims 1 to 4, which is an injection molded article of the vinyl chloride resin composition.

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