Method of manufacturing blow molded article, resin composition, and pellet

Abstract

To provide a method of manufacturing a blow molded article capable of preventing a component derived from wax from migrating to a surface of the blow molded article.SOLUTION: A method of manufacturing a blow molded article has a step of blow molding using a resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound, to obtain the blow molded article.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a blow molded article, a resin composition, and pellets. [Background technology]

[0002] In electrophotographic image forming devices, toner bottles that supply toner and the like need to be strong enough not to break when dropped, so blow-molded products made of polyethylene (hereinafter sometimes referred to as "PE") or polypropylene (hereinafter sometimes referred to as "PP") are sometimes used in addition to polyethylene terephthalate, a polyester resin (Patent Document 1).

[0003] In recent years, from the viewpoint of environmental protection, thermoplastic resin products and their parts are collected, and then regenerated by temporarily changing their original shape and recycling them. Here, as described in paragraph

[0002] of Patent Document 2, chemical recycling and material recycling are known as methods for recycling thermoplastic resins such as polyethylene and polypropylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 06-067536 [Patent Document 2] JP 2009-001693 A Summary of the Invention [Problem to be solved by the invention]

[0005] Chemical recycling requires a multi-stage process as disclosed in Patent Document 2, and therefore requires decomposition equipment and polymerization equipment, resulting in high recycling costs. In addition, the environmental impact is also large. Meanwhile, in material recycling, a process of washing bottles is generally performed. However, bottle washing may be performed multiple times using water, acid, alkali, etc., and a drying process is also required. Therefore, bottle washing may also increase the environmental impact.

[0006] Therefore, from the viewpoint of reducing the environmental load, the present inventors simplified or omitted the washing of the toner bottle to be recycled, and produced a toner bottle again using polyethylene or polypropylene (hereinafter also referred to as "material recycled PE" or "MR-PE" or "material recycled PP" or "MR-PP") obtained from the toner bottle with toner still attached inside. Then, when toner was stored in the toner bottle obtained in this way, it was found that the surface of the toner particles may be deformed at the contact point between the toner in the toner bottle and the inner surface of the toner bottle. Toner particles with a deformed surface may cause development defects such as insufficient transfer during electrophotographic development (when the toner is transferred to the photosensitive drum), and as a result, may cause density unevenness in the electrophotographic image.

[0007] At least one aspect of the present disclosure is directed to providing a method for producing a blow-molded article that can prevent migration of wax-derived components to the surface of the blow-molded article. At least one aspect of the present disclosure is directed to providing a resin composition that contributes to preventing migration of wax-derived components to the surface of a blow-molded article. At least one aspect of the present disclosure is directed to providing a pellet that helps prevent migration of wax-derived components to the surface of a blow-molded article. [Means for solving the problem]

[0008] According to at least one embodiment of the present disclosure, a step of blow molding a resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound to obtain a blow molded article. A method for producing a blow molded article is provided, comprising: According to at least one embodiment of the present disclosure, there is provided a resin composition comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound. According to at least one embodiment of the present disclosure, there is provided a pellet comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound. Effect of the Invention

[0009] According to at least one embodiment of the present disclosure, a method for producing a blow-molded article capable of preventing migration of wax-derived components to the surface of the blow-molded article can be obtained. According to at least one embodiment of the present disclosure, a resin composition that contributes to preventing migration of wax-derived components to the surface of the blow-molded article can be obtained. Furthermore, according to at least one embodiment of the present disclosure, a pellet that contributes to preventing migration of wax-derived components to the surface of the blow-molded article can be obtained. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. 2 is a schematic diagram showing a method for molding a preform. [Diagram 3] FIG. 1 is a schematic diagram showing a stretch blow molding process. [Figure 4] FIG. 1 is a schematic diagram of a one-stage stretch blow molding process. [Diagram 5] FIG. 1 is a schematic diagram of direct blow molding. [Figure 6] FIG. 1 is a schematic diagram of a biaxially stretched blown bottle. [Figure 7] FIG. 1 is a schematic diagram of a direct blow bottle. [Figure 8] 1 is a presumed reaction scheme between a wax-derived component and a carbodiimide compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In the present disclosure, the descriptions "XX or more and YY or less" and "XX to YY" expressing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, any combination of the upper and lower limits of each numerical range is also disclosed. In addition, in the present disclosure, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0012] As described above, when toner is stored in a toner bottle molded using MR-PE or MR-PP obtained from a toner bottle with toner still attached thereto, deformation of the surface of the stored toner may occur. The present inventors speculate that the reason for this is as follows.

[0013] That is, it is believed that the toner bottle is contaminated with wax contained in the toner adhering to the toner bottle before recycling. It is believed that at least a part of the contaminated wax is present on the inside surface (hereinafter also referred to as the "inner surface") of the toner bottle formed using MR-PE or MR-PP. It is also believed that at least a part of the wax contained in the MR-PE or MR-PP is hydrolyzed by moisture in the air, etc., and the hydrolyzate is present on the inner surface of the toner bottle after blow molding. In addition, when a preform containing MR-PE or MR-PP is used as the resin mixture, at least a part of the wax in the preform is hydrolyzed by moisture in the air, etc., It is also considered that the hydrolyzate is present on the inner surface of the toner bottle after blow molding.

[0014] It is believed that the toner particles' surfaces are deformed when the toner contained in the toner bottle comes into contact with the wax and hydrolysates exposed on the inner surface of the toner bottle. Hereinafter, wax and its hydrolysates are collectively referred to as "wax-derived components." In addition, in the present disclosure, the deformation of the toner particle surface caused by the wax-derived components may be referred to as chemical attack.

[0015] It is believed that the migration of wax-derived components to the inner surface of a toner bottle is likely to occur during heating in blow molding. During blow molding, the raw material of the blow molded product is heated to or above the glass transition temperature of the main material, polyethylene or polypropylene. Polyethylene or polypropylene has high molecular mobility at or above its glass transition temperature. On the other hand, wax generally has a low molecular weight, for example, about 300 to 500, and wax hydrolysates have even lower molecular weights. Therefore, wax-derived components are likely to migrate to the surface, including the inner surface, of the blow molded product. Therefore, when the resin mixture is heated to above the melting point of the polyethylene or polypropylene that is the main material of the resin mixture and blow molded, it is thought that the wax-derived components migrate to the surfaces, including the inner surface, of the blow molded product. Therefore, there are more wax-derived components on the inner surface of the toner bottle, which is a blow molded product of MR-PE or MR-PP.

[0016] In addition, when a preform is used for blow molding, there is almost no difference in the concentration of wax-derived components between the inside and the inner surface of the preform immediately after molding. However, when the preform is stretch-blow molded, when the preform is heated to a temperature equal to or higher than the melting point of the polyethylene or polypropylene that is the main material of the preform, it is considered that the wax-derived components with low molecular weight migrate to the surface, including the inner surface, of the preform. Therefore, the wax-derived components are more abundant on the inner surface of the toner bottle, which is a stretch-blow molded product of a preform containing MR-PE or MR-PP.

[0017] Based on such considerations, the present inventors have conducted extensive research to obtain a blow molded article that can be used as a toner bottle that can prevent the migration of wax-derived components to the surface of the blow molded article and prevent deformation of the toner contained therein, on the premise that MR-PE or MR-PP recycled from a toner bottle with toner attached thereto is used. As a result, they have found that a blow molded article obtained by a method of blow molding a resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound contributes to solving the above-mentioned problems.

[0018] The present inventors speculate as follows why the blow molded article obtained from the above resin mixture contributes to solving the above problems. First, the resin mixture is melt-kneaded during blow molding, and during the melt-kneading process, the wax-derived components contained in the resin mixture react with the carbodiimide compound, polymerizing the wax-derived components. It is believed that the wax-derived components that have polymerized are less fluid. As a result, it is believed that the migration of the wax-derived components to the surface of the preform or blow molded product is suppressed.

[0019] Another reason is that when the wax contains an ester wax, as described above, the wax in the raw material is hydrolyzed by moisture in the air, etc., and a carboxylic acid is generated as one of the wax-derived components as shown in Fig. 8A. The generated carboxylic acid then migrates to the inner surface of the preform or toner bottle, which may result in deformation of the toner.

[0020] However, when the resin mixture contains a carbodiimide compound, in the process of melt-kneading the resin mixture, as shown in Figure 8B, carboxylic acid as a wax-derived component reacts with the carbodiimide compound, and the wax-derived component relatively polymerizes. As a result, it is considered that migration of the wax-derived component is suppressed, and the presence of the wax-derived component on the inner surface of the preform or blow molded product can be suppressed. Note that Rw1, Rw2, R1, R2, etc. in Figures 8A and 8B represent organic groups in the ester wax or carbodiimide compound.

[0021] A method for producing a blow-molded article according to an embodiment of the present disclosure includes a step of blow-molding a resin mixture containing at least a wax, polyethylene or polypropylene, and a carbodiimide compound to obtain a blow-molded article. More specifically, the method includes a step of blow-molding a molten kneaded product of a resin mixture containing at least a wax, polyethylene or polypropylene, and a carbodiimide compound to obtain a blow-molded article.

[0022] Here, "melt kneading" means applying a shear force to a resin mixture in a state where the resin mixture is heated to have fluidity, specifically, for example, a temperature above the glass transition temperature, particularly above the melting point, of the polyethylene or polypropylene in the resin mixture. Methods of applying a shear force to a resin mixture in a melt kneaded state include, for example, a method of applying a shear force to the resin mixture with a screw while heating the resin mixture using a twin screw extruder, a method of injection molding a melt of the resin mixture, and a method of extrusion molding a melt of the resin mixture.

[0023] More specifically, "melt kneading" includes, for example, heating the resin mixture to a temperature equal to or higher than the glass transition temperature of the polyethylene or polypropylene, more preferably equal to or higher than the melting point of the polyethylene or polypropylene, and applying a shear force in a state in which the polyethylene or polypropylene has fluidity and at least a part of the wax-derived component is melted, or at least a part of the carbodiimide compound is melted, or at least a part of the wax-derived component and at least a part of the carbodiimide compound are melted. The "melt kneaded product" includes a product obtained by cooling through the above-mentioned "melt kneading" process.

[0024] The method of blow molding is not particularly limited, and stretch blow molding, direct blow molding, etc. can be adopted. That is, the blow molded product may be a stretch blow molded product or a direct blow molded product.

[0025] Stretch blow molding is a method in which a preform is molded from a molten raw material as a resin mixture, and then the preform is stretch blow molded. On the other hand, direct blow molding is a method of directly blow molding a molten resin mixture. In this case, pellets formed by melt-kneading raw materials may be used as the resin mixture. Therefore, specific examples of melt kneading include melt kneading when producing pellets of a resin mixture, melt kneading when producing a preform for stretch blow molding, and melt kneading by extrusion using an injection molding machine or the like in direct blow molding.

[0026] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. However, the scope of the present invention is not limited to the following embodiment. In the following description, "%" means "% by mass" unless otherwise specified.

[0027] (pellets, preforms) Blow molded products are made by blow molding pellets or preforms as a resin mixture. That is, as the resin mixture, pellets and preforms formed by melt-kneading the raw materials can be used. The pellets may be a pellet mixture obtained by mixing different pellets (pellet blend).

[0028] The pellets contain at least a wax, polyethylene or polypropylene, and a carbodiimide compound. The pellets preferably contain a toner containing a wax. The method of forming the pellets will be described in detail below. The preform is manufactured from a melt-kneaded resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound. The preform preferably contains a toner containing wax. The preform can be molded, for example, by injection molding. The details of the molding method of the preform will be described later.

[0029] The polyethylene or polypropylene is not particularly limited as long as it is polyethylene or polypropylene having thermoplastic properties. A carbodiimide compound has at least one carbodiimide group represented by "-N=C=N-" in the molecule. Examples of the carbodiimide compound include carbodiimide and polycarbodiimide.

[0030] The polyethylene or polypropylene may be polyethylene or polypropylene that has been material recycled, or may be virgin polyethylene or polypropylene that has not undergone molecular weight reduction. However, the effect of the present disclosure is more pronounced when the polyethylene or polypropylene is MR-PE or MR-PP that has been recycled from toner bottles. Therefore, it is preferable that the resin mixture contains MR-PE or MR-PP. The MR-PE or MR-PP may be obtained by using recycled raw materials with toner attached to the surface. The toner contains components such as wax. That is, the MR-PE or MR-PP may contain wax.

[0031] <Polyethylene (PE)> Polyethylene (PE) is obtained by a polymerization reaction of ethylene. PE is not particularly limited, and known polyethylene can be used. For example, polyethylene may be at least one selected from the group consisting of HDPE (high density polyethylene), LDPE (low density polyethylene), and LLDPE (linear low density polyethylene). Preferably, polyethylene includes HDPE (high density polyethylene). For example, "KEIYO B5804" (product name, manufactured by Keiyo Polyethylene Co., Ltd.) can be used. It may also be a mixture with other resins.

[0032] <Polypropylene (PP)> Polypropylene (PP) is obtained by a polymerization reaction of propylene. The polypropylene is not particularly limited, and any known polypropylene can be used. For example, the polypropylene may be at least one selected from the group consisting of a homopolymer, which is a single polymer of propylene alone, a random copolymer, which is a copolymer with ethylene, and a block copolymer, which is a heterophase copolymer. Preferably, the polypropylene contains a block copolymer. For example, "Prime Polypro E701G" (trade name, manufactured by Prime Polymer Co., Ltd.) can be used. It may also be a mixture with other resins.

[0033] The content of polyethylene or polypropylene in the pellets or preforms is not particularly limited, but is preferably 80% by mass or more, more preferably 90% by mass or more, based on the mass of the pellets or preforms. Also, it is preferably 99.9% by mass or less, more preferably 99.5% by mass or less. For example, it is preferably in the range of 80 to 99.9% by mass or 90 to 99.5% by mass.

[0034] <Carbodiimide compound> A carbodiimide compound has at least one carbodiimide group in the molecule. Examples of the carbodiimide compound include carbodiimide and polycarbodiimide. Carbodiimide and polycarbodiimide have at least one carbodiimide group represented by "-N=C=N-" in the molecule. Among them, it is preferable to use a polycarbodiimide having two or more carbodiimide groups in the molecule, which is expected to interact (react) more efficiently with wax-derived components.

[0035] In the polycarbodiimide compound shown in FIG. 8, n represents an integer of 1 or more, and R2 is a divalent residue obtained by removing two isocyanate groups from a diisocyanate compound, has a benzene-based aromatic ring directly bonded to an NCN group, and has a structure in which both ortho positions of the benzene-based aromatic ring bonded to the NCN group have no substituent or only one substituent. In addition, R11 and R12 each independently represent a residue of an organic compound having one functional group capable of reacting with an isocyanate group. Such a polycarbodiimide is available, for example, as "Carbodilite HMV-15CA" (trade name, manufactured by Nisshinbo Chemical Co., Ltd.).

[0036] Polycarbodiimides can be produced, for example, by heating an organic isocyanate in the presence of a catalyst and subjecting it to a decarboxylation condensation reaction. Examples of the organic isocyanate include aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. Specific examples of polycarbodiimides include aromatic polycarbodiimides such as poly(4,4'-diphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(diisopropylphenylcarbodiimide), and poly(triisopropylphenylcarbodiimide); and alicyclic polycarbodiimides such as poly(dicyclohexylmethanecarbodiimide). These polycarbodiimides may be used alone or in any combination of two or more.

[0037] Among these polycarbodiimides, aliphatic polycarbodiimides are preferred. For example, commercially available aliphatic polycarbodiimides such as "Carbodilite HMV-15CA", "Carbodilite LA-1" and "Carbodilite HMV-5CA-LC" (all trade names, manufactured by Nisshinbo Chemical Inc.) can be used.

[0038] In order to sufficiently react the wax-derived component with the carbodiimide compound, it is preferable to melt-knead the resin mixture containing the wax-derived component and the carbodiimide compound. It is considered that the reaction between the wax-derived component and the carbodiimide compound is more easily promoted by melt-kneading. Then, the melt-kneaded product thus obtained can be used to form pellets or preforms, and the pellets or preforms can be blow-molded to obtain blow-molded products.

[0039] Non-limiting methods for obtaining pellets and preforms include the following methods. For example, a mixture containing at least a wax, polyethylene or polypropylene, and a carbodiimide compound can be melt-kneaded, and the resulting melt-kneaded mixture can be pelletized to form pellets. The pellets obtained by the above method can be melt-kneaded and then molded to produce a preform.

[0040] The form in which the carbodiimide compound is added is not particularly limited. For example, a powdered carbodiimide compound can be used. For example, MR-PE or MR-PP containing wax can be melt-kneaded to form pellets. A toner bottle containing polyethylene or polypropylene to which a toner containing wax is attached can be pulverized, and a carbodiimide compound can be added to the pulverized product obtained and melt-kneaded to form pellets. The resulting pellets can be blow molded by a method described below to produce a blow molded product. That is, the step of blow molding a resin mixture to obtain a blow molded product preferably includes a step of obtaining pellets of a melt-kneaded product of the resin mixture and a step of direct blow molding using the pellets.

[0041] In addition, the pellets obtained by the above method can be melt-kneaded and then molded to produce a preform. The molding method of the preform will be described later. The obtained preform can be blow molded by the method described later to produce a blow molded article. That is, the process of blow molding a resin mixture to obtain a blow molded article preferably includes a process of obtaining pellets of the melt-kneaded resin mixture, a process of producing a preform using the pellets, and a process of blow molding the preform.

[0042] Since carbodiimide compounds such as polycarbodiimide have high reactivity, it is preferable to stabilize the physical properties of the reaction product between the wax-derived component and the carbodiimide compound while controlling the amount of the carbodiimide compound added. For example, the carbodiimide compound may be diluted in advance with polyethylene or polypropylene, and melt-kneaded at a temperature equal to or higher than the melting point of the polyethylene or polypropylene to prepare master batch pellets (second pellets). The master batch pellets may be mixed with pellets (first pellets) containing wax and polyethylene or polypropylene to prepare a pellet mixture, which may be melt-kneaded.

[0043] It is preferable that the process for producing a blow-molded article comprises the steps of melt-kneading a wax and a polyethylene or a polypropylene to form first pellets, melt-kneading a carbodiimide compound and another polyethylene or a polypropylene to form second pellets, mixing the first pellets with the second pellets to obtain a pellet mixture, and blow-molding the pellet mixture.

[0044] Specifically, for example, wax (preferably a toner containing wax) and polyethylene or polypropylene are melt-kneaded to form first pellets. The first pellets are pellets of MR-PE or MR-PP containing wax, obtained by melting and pelletizing crushed products of used PE or PP toner bottles.

[0045] On the other hand, separately from the step of forming the first pellets, the carbodiimide compound and another polyethylene or polypropylene are melt-kneaded to form second pellets. The other polyethylene or polypropylene used in forming the second pellets is not particularly limited, and may be the same polyethylene or polypropylene as the polyethylene or polypropylene contained in the first pellets, or may be a different polyethylene or polypropylene.

[0046] In preparing the master batch pellets (second pellets), the dilution ratio when diluting the carbodiimide compound with polyethylene or polypropylene is not particularly limited. For example, it is preferable to dilute the carbodiimide compound with polyethylene or polypropylene 5 to 15 times, more preferably 10 times. By setting the dilution ratio at 5 times or more, the concentration of the carbodiimide compound is in an appropriate range, and unevenness is unlikely to occur. In addition, by setting the dilution ratio at 15 times or less, the amount of the carbodiimide compound used can be set to an appropriate range without excessively decreasing. In this case, the obtained master batch pellets contain polyethylene or polypropylene and unreacted carbodiimide compound.

[0047] Next, the master batch pellets (second pellets) are mixed (pellet blended) with polyethylene or polypropylene pellets (first pellets) to obtain a pellet mixture. The obtained pellet mixture is melt-kneaded at a temperature equal to or higher than the melting point of polyethylene or polypropylene, so that the carbodiimide compound and the wax-derived component contained in the polyethylene or polypropylene pellets (first pellets) can react more uniformly. Here, pellet blending refers to stirring and mixing a plurality of materials at a temperature at which the resin components do not melt, unlike melt kneading, to obtain a substantially uniform state.

[0048] Next, pellets (third pellets) containing a melt-kneaded mixture of the first pellets and the second pellets may be obtained, and the melt of the third pellets may be blow-molded. Alternatively, the melt of the third pellets may be molded into a preform by a method such as injection molding. Alternatively, without preparing the third pellets, the first pellets and the second pellets may be uniformly stirred (pellet blended) using a blender or the like to prepare a molten pellet mixture, which may then be directly blow molded. That is, a pellet mixture of the first pellets and the second pellets can be blow molded by the above-mentioned method to produce a blow molded product. The blow molding step preferably includes a step of injection molding the pellet mixture.

[0049] Alternatively, the melt of the pellet mixture can be molded into a preform by a method such as injection molding. In the process of injection molding of the melt of the pellet mixture, a shear force is applied to the melt, and the obtained preform is included in the resin composition containing the melt kneaded product according to the present disclosure. By uniformly stirring two types of pellets and then molding them, the carbodiimide compound can react more uniformly with the wax-derived component contained in the polyethylene or polypropylene.

[0050] As another method, a melt-kneaded mixture containing at least the wax, polyethylene or polypropylene, and the carbodiimide compound may not be pelletized, but may be molded into a preform following the melt-kneading step, and the resulting preform may be used as the resin mixture. For example, a toner containing wax and a toner bottle containing polyethylene or polypropylene may be pulverized, and the melt-kneaded mixture of the pulverized product may be directly molded into a preform. As another method, for example, the melt-kneaded product is not pelletized, and the resin mixture is subsequently melt-kneaded to form a blow-molded product.

[0051] The amount of the carbodiimide compound added is preferably 220 parts by mass or more, more preferably 400 parts by mass or more, and more preferably 450 parts by mass or more, relative to 100 parts by mass of the wax. Also, it is preferably 10,000 parts by mass or less, more preferably 1,500 parts by mass or less, and even more preferably 1,400 parts by mass or less. The amount of the carbodiimide compound added relative to 100 parts by mass of the wax is, for example, preferably 220 to 10,000 parts by mass, more preferably 400 to 1,500 parts by mass, and even more preferably 450 to 1,400 parts by mass. By setting the amount of the carbodiimide compound to be added within the above range, the wax-derived component and the carbodiimide compound can be reacted sufficiently and reliably.

[0052] When the amount of the carbodiimide compound added per 100 parts by mass of wax is 220 parts by mass or more, the reaction between the carbodiimide compound and the wax-derived components proceeds sufficiently. As a result, it is preferable because it is easy to sufficiently suppress the migration of the wax-derived components to the surface of the blow molded article. In addition, when the amount of the carbodiimide compound added per 100 parts by mass of wax is 10,000 parts by mass or less, the reaction between the carbodiimide compound and the wax-derived components is suppressed to a range that is not excessive, so that the viscosity of the polyethylene or polypropylene when melted does not become too high, and an appropriate viscosity is obtained. As a result, molding defects due to a decrease in the fluidity of the resin during blow molding are less likely to occur, which is preferable. By setting the amount of the carbodiimide compound to be added within the above range, it is possible to suppress migration of wax to the surface of the molded article while maintaining moldability during blow molding.

[0053] Examples of a method for reacting a carbodiimide compound with a wax-derived component include a method in which a mixture of a carbodiimide compound or masterbatch pellets containing a carbodiimide compound and polyethylene or polypropylene containing wax is heated to a temperature equal to or higher than the melting point of the polyethylene or polypropylene using an extruder to melt and knead the mixture.

[0054] The melt-kneading means is not particularly limited, and known means such as a twin-screw extruder can be used. As the twin-screw extruder, for example, "PCM-46" (trade name, manufactured by Ikegai Corporation) can be used. The temperature during melt-kneading is not particularly limited, but is preferably 180 to 260°C, more preferably 190 to 250°C, and even more preferably 200 to 240°C. By melt-kneading, the wax is hydrolyzed, and the decomposed wax becomes more reactive with the carbodiimide. It is also considered that the reaction between the decomposed wax and the carbodiimide compound is more likely to be promoted.

[0055] The wax contained in the toner is not particularly limited, and may be any wax commonly used in toners. Specific examples of the wax are listed below. Examples of the wax include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymers, polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; or block copolymers thereof; vegetable waxes such as candelilla wax, carnauba wax, Japan wax, and jojoba wax; animal waxes such as beeswax, lanolin, and spermaceti; mineral waxes such as ozokerite, ceresin, and petrolactam; waxes mainly composed of aliphatic esters such as montan acid ester wax and castor wax; and waxes in which aliphatic esters have been partially or completely deoxidized, such as deoxidized carnauba wax.Further, saturated straight-chain fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having even longer alkyl chains; unsaturated fatty acids such as brassidic acid, eleostearic acid, or valinaric acid; saturated alcohols such as stearyl alcohol, eicosyl alcohol, behenyl alcohol, carnabyl alcohol, ceryl alcohol, melissyl alcohol, or alkyl alcohols having even longer alkyl chains; polyhydric alcohols such as sorbitol; aliphatic amides such as linoleic acid amide, oleic acid amide, or lauric acid amide; saturated aliphatic bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, or hexamethylene bisstearic acid amide; ethylene bis(oxyethylene)-2-hydroxyethyl ether; Examples of the wax include unsaturated fatty acid amides such as m-xylene bisstearamide, hexamethylene bisoleamide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bisstearamide and N,N'-distearyl isophthalamide; fatty metal salts (generally called metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; waxes obtained by grafting aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid; partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having hydroxyl groups obtained by hydrogenating vegetable oils and fats. Rw1 in the waxes exemplified in FIGS. 8A and 8B represents, for example, a hydrocarbon group having 1 to 40 carbon atoms. The hydrocarbon group is typically an alkyl group.

[0056] These waxes may be used alone or in any combination of two or more. The wax preferably contains an ester wax. It is considered that the ester wax is hydrolyzed during blow molding or in a toner bottle, and becomes a component that deforms the toner. However, according to the method of the present disclosure, the hydrolyzate is polymerized by reacting with a carbodiimide compound, and migration to the surface of the blow molded article can be prevented.

[0057] In addition, it is preferable to use these waxes whose molecular weight distribution is sharpened by using a press sweating method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method, a melt crystal precipitation method, etc. In addition, it is also preferable to use waxes from which low molecular weight solid fatty acids, low molecular weight solid alcohols, low molecular weight solid compounds, and other impurities have been removed. Specific examples include Viscol (registered trademark) 330-P, 550-P, 660-P, and TS-200 (Sanyo Chemical Industries, Ltd.), Hiwax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, and 110P (Mitsui Chemicals, Inc.), Sasol H1, H2, C80, C105, and C77 (Schumann-Sasol), HNP-1, HNP-3, and HN P-9, HNP-10, HNP-11, HNP-12 (Nippon Seiro Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.), wood wax, beeswax, rice wax, candelilla wax, carnauba wax (available from Cerarica NODA Co., Ltd.), and the like.

[0058] The blow molded article may contain a colorant, if necessary. Examples of colorants include carbon black. The content of the colorant in the blow molded article is, for example, 0.01 to 0.20% by mass, or 0.02 to 0.10% by mass.

[0059] <Stretch blow molding> A method for producing a blow molded product by stretch blow molding will be described below. Stretch blow molding is a method in which a preform is molded from a molten raw material, and then the preform is stretch blow molded. (I) Process for manufacturing preforms A method for producing the preform is described below. As shown in Fig. 2, a test tube-shaped preform 104 is molded by injection molding. Specifically, a heating cylinder 105 heats the material put into an injection molding machine 101 to a molten state, and an extrusion screw 207 injects the molten material into preform molds 102 and 103, and after cooling, the material is removed from the mold to obtain a preform 104. As the material, pellets containing wax (preferably a toner containing wax), polyethylene or polypropylene, and a carbodiimide compound can be used. Alternatively, a melt-kneaded mixture containing wax (preferably a toner containing wax), polyethylene or polypropylene, and a carbodiimide compound may be used.

[0060] In the preform molding step, it is preferable to mold the preform by injection molding. That is, it is preferable that the preform molding step includes a step of injection molding a melt-kneaded product of pellets. In addition, it is preferable that the preform has a test tube shape. In the preform molding step, the raw material is melted, and the wax is hydrolyzed. The wax-derived component is easily polymerized by reacting with the carbodiimide compound.

[0061] (II) A process for producing a blow molded product by stretch blow molding the preform Next, a process for producing a blow molded product by stretch-blow molding a preform will be described. As shown in Fig. 3, a preform 104 is biaxially stretch-blow molded (biaxially stretch-molded). First, the preform 104 is placed in a heating furnace 107 and heated to a temperature at which it can be stretched.

[0062] The heated preform 104 is removed from the heating furnace 107 and placed in the mouth of a blow mold 108. The blow mold 108 has a cavity formed therein by combining a left mold 108-1 and a right mold 108-2. It is preferable to place the heated preform at the mouth of the blow mold in a short time (for example, within 10 seconds) so that the temperature of the preform does not drop before the start of the biaxial stretching step.

[0063] The heated preform placed in the blow mold 108 is stretched in the longitudinal direction of the preform using a stretch rod 109. This is called the first stretching. In the first stretching, it is preferable to flow gas so that the preform 104 does not come into contact with the stretch rod 109. The pressure of the gas at this time is called the first blow pressure.

[0064] After the first stretching, gas 110 is introduced from the preform mouth 106 to stretch the preform in the lateral direction (the circumferential direction, i.e., the direction intersecting the stretching rod 109). This is called the second stretching. The pressure of the gas at this time is called the secondary blow pressure. Examples of the gas introduced during the first and second stretching include air, nitrogen, carbon dioxide, and argon.

[0065] By carrying out these primary and secondary stretching steps, the preform 104 expands in each direction indicated by the arrows 111 and adheres to the inner wall of the blow mold 108, and is cooled and solidified in this state to produce a blow-molded product 112. The step of blow molding the preform preferably includes a step of stretching the preform in the longitudinal direction of the preform using a stretching rod, and a step of injecting gas into the longitudinally stretched preform to stretch it in the circumferential direction of the preform.

[0066] Next, the left mold 108-1 and the right mold 108-2 of the blow mold 108 are separated, and the blow-molded article 112 is removed from the blow mold 108. Since this blow-molded article 112 is stretched in both the vertical and horizontal directions, it becomes a molded article with high strength.

[0067] In the stretching step of injection stretch blow molding, it is preferable that the preform is in a non-crystallized state (non-crystalline, i.e., amorphous state). If it is kept at the blow molding temperature in an amorphous state, the PE or PP will stretch-crystallize in the stretched direction by blowing, i.e., biaxial stretch molding, and it becomes possible to form a bottle with high strength.

[0068] There are two types of injection stretch blow molding: one-stage and two-stage. The one-stage method uses the residual heat of the preform immediately after it is removed from the mold to stretch blow mold it as is, or after adjusting the temperature. The two-stage method cools the preform down to room temperature, and then stretch blow molds it again after adjusting the temperature. That is, the step of molding the pellets to produce a preform and the molding step of stretch-blow molding the preform to produce a stretch-blow molded article may be performed continuously while maintaining the temperature of the preform. Also, after the step of molding the pellets to produce a preform, the preform may be cooled to room temperature and then stretch-blow molded to produce a stretch-blow molded article.

[0069] A schematic diagram of the one-stage method is shown in Fig. 4. In the one-stage method, after injection molding of a preform 104 from an injection molding machine 101, the preform 104 is immediately kept warm and heated to a blow molding temperature (for example, 140 to 160°C) and blow molded to produce a blow-molded product 112. In the one-stage method, an apparatus in which an injection molding device and a blow molding device are integrated is used.

[0070] In the two-stage method, the preform is injection molded, cooled, and removed, and then heated to the blow molding temperature (e.g., 140 to 160°C) in a separate blow molding device. In the two-stage method, the injection molding equipment and the blow molding equipment are not integrated, but are independent of each other.

[0071] The injection stretch blow molding method can be appropriately selected depending on the components contained in the preform, etc. The one-stage method is preferable in that it does not include a step of cooling the preform and therefore requires less energy for reheating compared to the two-stage method.

[0072] <Direct blow molding> The method for producing a blow-molded product by direct blow molding will be described below. Direct blow molding is a method in which molten raw material or pellets formed from raw material are directly blow-molded. In direct blow molding, a resin mixture in a molten state is blow molded using an injection molding machine or the like. As a material used in direct blow molding, pellets containing at least wax (preferably a toner containing wax), polyethylene or polypropylene, and a carbodiimide compound can be used. Alternatively, a melt-kneaded product of a resin mixture containing wax, polyethylene or polypropylene, and a carbodiimide compound may be used.

[0073] An embodiment of a method for producing a blow-molded article by direct blow molding will be described below. As shown in FIG. 5, a resin mixture (the above-mentioned pellets or a melt-kneaded mixture of raw materials) is charged into a direct blow molding machine 301, and while being heated and melt-kneaded, the melt-kneaded resin mixture is allowed to drip into a cylindrical shape under its own weight. Before the molten and kneaded resin mixture cools and solidifies, it is sandwiched between metal molds 302 and simultaneously inflated with gas from blow pins 303. Examples of the gas include air, nitrogen, carbon dioxide, and argon. In other words, the method of producing a blow molded product by direct blow molding preferably includes a step of sandwiching the molten and kneaded resin mixture between metal molds and injecting gas to stretch the resin mixture. The molten resin mixture is stretched by the gas, so that the resin mixture adheres to the inner wall of the blow mold and is cooled and solidified in that state. Finally, the blow mold is opened and the blow molded product is removed from the blow mold. The resin contained in the resin mixture is stretched by this blow molding, so a molded product with high strength can be obtained.

[0074] Next, a method for checking chemical attack on the toner contained in the toner bottle obtained by blow molding will be described. Toner is placed in a toner bottle obtained by blow molding. The toner bottle containing the toner is left in a usage environment. In the evaluation of chemical attack according to the present disclosure, the usage environment is set to 50°C for 72 hours, and the toner bottle is left in a test thermostatic chamber. The toner bottle exposed to the usage environment is removed, and only the toner adhering to the inner surface of the bottle is taken out from the toner contained in the toner bottle and observed under an electron microscope. In the present disclosure, the toner was discharged from the toner bottle with the opening of the bottle facing downward, and then the toner adhering to the inner surface of the bottle was attached to an adhesive tape, and only the toner adhering to the inner surface of the bottle was removed. When the deformation of the toner particle surface of the toner adhering to the inner surface of the bottle is observed with an electron microscope, the toner particles that have been subjected to chemical attack can be seen to have deformed areas on the contact surface with the toner bottle. The deformed areas on the contact surface with the toner bottle can be identified by the fact that they have less unevenness compared to the surrounding areas in the image observed with the electron microscope.

[0075] (Image forming device) Hereinafter, an image forming apparatus using a toner storage bottle obtained by the manufacturing method of the present disclosure will be described with reference to the drawings. In the figure, reference numeral 80 denotes the main body of the image forming apparatus. The image forming apparatus 80 is configured as a so-called intermediate transfer tandem type image forming apparatus in which four color image forming units are arranged side by side on an intermediate transfer belt.

[0076] The image forming apparatus 80 forms an image as follows. First, the exposure device 50 (50y, 50m, 50c, 50bk) forms an electrostatic latent image on the photosensitive drum 17 (17y, 17m, 17c, 17bk) based on print data. Then, the developing device 21 (21y, 21m, 21c, 21bk) develops the formed electrostatic latent image to form a toner image.

[0077] The toner image is transferred onto an intermediate transfer body 62 by a primary transfer device 60 (60y, 60m, 60c, 60bk), and then transferred onto a sheet material S supplied from a paper feeder 63 in a secondary transfer section 64 (64a, 64b). Next, the toner image transferred onto the sheet S is fixed onto the sheet material S by a fixing means 68, and then the sheet material S is discharged onto a paper discharge tray 70.

[0078] In the image forming apparatus 80, a toner image is formed by developing in the developing device 21 as described above. At this time, detachable toner bottles 3 (3Y, 3M, 3C, 3Bk) can be used to supply toner to the developing device 21. The toner bottles manufactured by the manufacturing method of the present disclosure are toner bottles used in this manner. EXAMPLES

[0079] The present disclosure will be described in detail below using examples and comparative examples. However, the present disclosure is not limited to these examples. In the following examples and comparative examples, "%" means "% by mass" unless otherwise specified.

[0080] (Examples A1 to A12, Comparative Examples A1 and A2) <Production of toner bottles by stretch blow molding> A one-stage stretch blow molding machine (ASB-70DPH, manufactured by Nissei ASB Machinery Co., Ltd.) was used to produce a toner bottle (total length (B) 439.5 mm, diameter (A) 101 mm) as shown in Figure 7. The blow stretch ratio was set to "vertical ratio x horizontal ratio = 6.7". The "longitudinal ratio" of the blow stretch ratio is a value calculated by dividing the "total length after stretching" by the "total length (before stretching) of the part (heated part) of the preform that reaches the stretching temperature." The "lateral ratio" of the blow stretch ratio is a value calculated by dividing the "diameter of the middle part after stretching" by the "diameter of the middle part of the preform (before stretching)".

[0081] First, the materials shown in Table 1 below were melt-kneaded and then pelletized to prepare a master batch with a carbon black concentration of 5 mass %. [Table 1]

[0082] Next, the master batch having a carbon black concentration of 5% by mass prepared above and PP were mixed together. The ingredients were mixed in the ratio shown in Table 2, melt-kneaded, and then pelletized to obtain pellets of a resin mixture. [Table 2]

[0083] <Blow molding conditions> The pellets as the resin mixture were fed into an extrusion molding device of a one-stage stretch blow molding machine (product name: ASB-70DPH; manufactured by Nissei ASB Machinery Co., Ltd.), and a toner bottle was molded by biaxial stretch blow molding. The one-stage stretch blow molding machine can continuously carry out a process of manufacturing a test tube-shaped preform by injection molding, and a process of manufacturing a bottle-shaped molded product by biaxial stretch blow molding the preform. The screw diameter of the injection molding machine in the molding machine was 54 mm.

[0084] First, a mold capable of molding a preform having an outer diameter of 30 mm, a wall thickness of 3.7 mm, and a length of 220 mm was prepared as a mold for molding a preform. Then, a preform was molded under the following molding conditions. Screw diameter: 54mm Screw position before filling the cavity with resin mixture: 95mm ·Injection speed Up to 5mm of screw advance: 50% of maximum speed Advance the screw another 20mm: 30% of maximum speed To advance the screw an additional 35mm: 25% of maximum speed PV switching position: 35mm First stage of pressure retention 30MPa, 4s Second stage of pressure retention 20MPa, 7.99s ·Heating tube temperature: 230℃ ·Cooling time: 10.0 seconds Mold temperature: 20℃

[0085] After a cooling time of 10.0 seconds had elapsed, the preform was demolded and transported to the biaxial stretch blow station of the one-stage stretch blow molding machine. The temperature of the preform during transportation was controlled as follows. Preform heating temperature 10% of the preform's total length from the top of the preform 180℃ 25% of the preform's total length from the top of the preform 200℃ 50% of the preform's total length from the top of the preform 200℃ 75% of the preform's total length from the top of the preform 180℃

[0086] Next, the preform adjusted to the above temperature is placed in a cylindrical mold adjusted to a temperature of 20° C. and has a size corresponding to the size of the toner bottle, and is subjected to biaxial stretch blow molding to obtain a blown product. The temperature of the preform was controlled by heating during transportation, and the surface temperature of the center of the preform was 150°C just before it was placed in the cylindrical mold. First, the stretch bar, which was in the retreated position, was inserted into the preform through the opening of the preform and advanced until it contacted the top of the preform. Then, the air pressure driving the stretch bar was increased to 1.2 MPa to advance the stretch bar further. Next, 0.5 seconds after the start of the further advancement of the stretch bar, primary air was introduced into the preform through the opening of the preform. The pressure of the primary air was set to 0.4 MPa. Next, 0.7 seconds after the introduction of the primary air, secondary air was introduced. The pressure of the secondary air was set to 1.2 MPa. Air was introduced into the preform for 2.7 seconds from the start of the introduction of the primary air. Next, the pressure inside the preform was returned to normal pressure over 0.5 seconds. In this manner, a toner bottle was produced by blow molding. This bottle is a toner bottle containing virgin PP that has not been recycled. Using the above method, 200 toner bottles containing virgin PP were prepared.

[0087] (Example A1) <Production of recycled pellets> All of the 200 toner bottles containing virgin PP prepared above were filled with black toner contained in an electrophotographic toner bottle (product name Toner NPG-67; manufactured by Canon Inc.). The black toner contained 6.9 parts by mass of ester wax per 100 parts by mass of toner. Next, the black toner filled in the toner bottle containing virgin PP was discharged by directing the opening of the toner bottle vertically downward. Even after this operation, a small amount of black toner was attached to the inner wall of each toner bottle. At this time, the amount of black toner remaining in the toner bottle was 0.321% by mass on average for the 200 toner bottles, based on the mass of the toner bottle body. Here, the mass of the toner bottle body refers to the mass of the toner bottle and only the toner remaining therein, after all the supply parts and the like attached to the toner bottle have been removed.

[0088] Next, 200 of the toner bottles with toner attached thereto prepared above were crushed into pieces of about 5 to 10 mm square using a crusher to obtain crushed products (hereinafter also referred to as flake products). The flake products were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corporation) at a temperature of 210°C, a screw rotation speed of 200 rpm, vent degassing of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The obtained recycled pellets were designated as MR-PP (1-1) (first pellets).

[0089] <Making blow bottles> A polycarbodiimide compound was added to MR-PP (1-1), and biaxial stretch blow molding was performed using the one-stage stretch blow molding apparatus under the same blow molding conditions as described above. The polycarbodiimide compound was diluted and prepared in advance as a master batch pellet so that it could be easily mixed uniformly in a blender. Specifically, the polycarbodiimide compound and PP were mixed in the ratio shown in Table 3, melt-kneaded, and then pelletized to prepare a polycarbodiimide master batch pellet (second pellet). [Table 3]

[0090] Before feeding the material into the molding machine, 3.0 mass% of polycarbodiimide master batch pellets (second pellets) were added to MR-PP (1-1) (first pellets) and mixed uniformly in a blender to form a pellet mixture. The polycarbodiimide master batch pellets were diluted at the ratio shown in Table 3, so polycarbodiimide was actually contained at a ratio of 0.3 mass%. The pellet mixture stirred in the blender was put into the blow molding machine and biaxial stretch blow molding was performed under the same blow molding conditions as described above. The obtained toner bottle was named toner bottle (1-1A). Toner was placed in the toner bottle (1-1A) and left in a usage environment of 50°C for 72 hours. Thereafter, the toner adhering to the inner surface of the toner bottle was removed, and the surface of the toner particles was observed under an electron microscope. As a result, no deformation of the toner particle surface was confirmed, and it was confirmed that no chemical attack had occurred.

[0091] (Examples A2 and A3) Toner bottles (1-2A) and (1-3A) were produced in the same manner as in Example A1, except that the compounding ratio of MR-PP (1-1) and polycarbodiimide master batch was changed as shown in Table 4. Using toner bottles (1-2A) and (1-3A), the occurrence of chemical attack was checked in the same manner as for toner bottle (1-1A), and it was confirmed that no chemical attack occurred. [Table 4] The toner bottles (1-1A), (1-2A), and (1-3A) were crushed and melt-kneaded to form first pellets, which were then mixed with second pellets (master batch pellets) of a polycarbodiimide compound prepared in advance before being fed into a molding machine.

[0092] (Example A4) <Production of recycled pellets> A polycarbodiimide compound (trade name: Carbodilite HMV-15CA; manufactured by Nisshinbo Chemical Co., Ltd.) of 0.3% by mass was uniformly added to the flakes prepared in the same manner as in Example A1, and the mixture was melt-kneaded using a twin-screw extruder (manufactured by Ikegai Co., Ltd., PCM-46) at a temperature of 210°C, a screw speed of 200 rpm, vent degassing at -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The polycarbodiimide used here was in powder form, and was used as a master batch. The recycled pellets obtained were named MR-PP (2-1).

[0093] <Making blow bottles> The MR-PP (2-1) was placed in the one-stage blow molding apparatus and biaxial stretch blow molding was carried out under the same blow molding conditions as described above. Since polycarbodiimide was added during the extrusion process of the MR-PP (2-1), unlike Examples A1 to A3, no polycarbodiimide was added when the material was put into the blow molding machine. The obtained toner bottle was named toner bottle (2-1A).

[0094] (Examples A5 and A6) Pellets of MR-PP (2-2) and (2-3) were prepared in the same manner as for MR-PP (2-1), except that the blending ratio of polycarbodiimide in Example A4 was changed as shown in Table 5. [Table 5]

[0095] Each of the obtained pellets was subjected to biaxial stretch blow molding under the same conditions as in Example A4 to obtain toner bottles (2-2A) and (2-3A). Toner was placed in each bottle, and the toner attached to the inner surface of the toner bottle was observed for deformation of the toner particle surface after leaving it at 50°C for 72 hours. Toner bottle (2-2A) was evaluated as Example A5, and toner bottle (2-3A) was evaluated as Example A6. As a result, no deformation of the toner particle surface was confirmed in Examples A4 to A6, and it was confirmed that no chemical attack occurred.

[0096] In Examples A4 to A6, the master batch pellets were not prepared, and the carbodiimide compound was added when the crushed product (flakes) of the toner bottle with the toner attached thereto was melt-kneaded and pelletized in an extruder. In this method, the wax and the carbodiimide compound were sufficiently kneaded in the extruder, and the reaction between the wax and the carbodiimide compound was considered to have progressed sufficiently. Therefore, it is considered that the migration of the wax to the inner surface of the toner bottle was sufficiently prevented, and the chemical attack was suppressed. Table 6 shows the results of evaluation of chemical attack after molding of the toner bottles of Examples A4 to A6. [Table 6] As described above, polycarbodiimide was added to the toner bottles (2-1A), (2-2A) and (2-3A) in the process of crushing the toner bottles, melt-kneading them and forming pellets.

[0097] (Comparative Example A1) <Production of recycled pellets> The flakes prepared in the same manner as in Example A1 were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corporation) at a temperature of 210°C, a screw speed of 200 rpm, vent degassing at -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. No polycarbodiimide compound was added during melt-kneading. The resulting recycled pellets were designated MR-PP (2-4).

[0098] <Making blow bottles> The MR-PP (2-4) was placed in the one-step stretch blow molding machine and biaxial stretch blow molding was carried out under the same blow molding conditions as described above. The resulting toner bottle was designated toner bottle (2-4A). Toner was placed in a toner bottle (2-4A) and left in the usage environment (50°C, 72 hours) to conduct an environmental test. After the test, the toner adhering to the inner surface of the toner bottle was observed by the above-mentioned method, and it was confirmed that the surface of the toner particles had been deformed and chemically attacked. [Table 7]

[0099] <Manufacturing toner bottles by direct blow molding> A toner bottle (total length (B) 150 mm, diameter (A) 76 mm) shown in Figure 7 was created using a direct blow molding device (model name: MSE-55E / 54M-AP(E2), Tahara Co., Ltd.).

[0100] First, the materials shown in Table 8 below were melt-kneaded and then pelletized to prepare a master batch with a carbon black concentration of 5 mass %. [Table 8] Next, the master batch with a carbon black concentration of 5% by mass prepared above and PP were mixed in the ratio shown in Table 9 below, melt-kneaded, and then pelletized to obtain pellets as a resin mixture. [Table 9]

[0101] <Direct blow molding conditions> The pellets as the resin mixture were fed into a direct blow molding machine (model name: MSE-55E / 54M-AP(E2), Tahara Co., Ltd.) to mold a toner bottle. The screw diameter of the injection molding machine in the molding machine was 50 mm.

[0102] Direct blow molding was performed under the following molding conditions. Extruder screw diameter: 50mm Extruder cylinder temperature: 210℃ -Extrusion rate 10kg / h Blow pressure: 0.6MPa Cooling time: 15s Mold temperature: 15℃ A toner bottle was produced by the above-mentioned direct blow molding. This toner bottle is made of virgin PP that has not been recycled. Using the above method, 200 toner bottles were produced using virgin PP.

[0103] (Example A7) <Production of recycled pellets> All 200 toner bottles containing virgin PP prepared above were filled with black toner contained in an electrophotographic toner bottle (product name Toner NPG-67; manufactured by Canon Inc.). The black toner contained 6.9 parts by mass of ester wax per 100 parts by mass of toner. Next, the black toner filled in the toner bottle containing virgin PP was discharged by directing the opening of the toner bottle vertically downward. Even after this operation, a small amount of black toner was still attached to the inner wall of each toner bottle. At this time, the amount of black toner remaining in the toner bottle was 0.321% by mass, based on the mass of the toner bottle body, on the average value of the 200 toner bottles. Note that the mass of the toner bottle body here refers to the mass of the toner bottle after removing all the supply parts and the like attached to the toner bottle. The mass of the toner particles is the mass of the toner particles alone, and the mass of the toner particles alone.

[0104] Next, 200 of the toner bottles with toner attached thereto prepared above were crushed into pieces of about 5 to 10 mm square using a crusher to obtain crushed products (hereinafter also referred to as "flake products"). The wax content per 100 parts by mass of the obtained flake products was 0.022 parts by mass. The wax content in the flake products was measured using GPC and FT-IR. Next, the above flakes were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corporation) at a temperature of 210°C, a screw speed of 200 rpm, vent degassing pressure of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The obtained recycled pellets were designated as MR-PP (3-1) (first pellets).

[0105] <Making blow bottles> A polycarbodiimide compound was added to MR-PP (3-1), and direct blow molding was performed under the same blow molding conditions as described above. The polycarbodiimide compound was diluted and prepared in advance as a master batch pellet so that it could be easily mixed uniformly in a blender. Specifically, the polycarbodiimide compound and PP were mixed in the ratio shown in Table 10, melt-kneaded, and then pelletized to prepare a polycarbodiimide master batch pellet (second pellet). [Table 10]

[0106] Before feeding the material into the molding machine, 3.0% by mass of polycarbodiimide master batch pellets (second pellets) were added to MR-PP (3-1) (first pellets) and uniformly stirred in a blender to obtain a pellet mixture. The polycarbodiimide master batch pellets were diluted at the ratio shown in Table 10, so polycarbodiimide was actually contained at a ratio of 0.3% by mass. The pellet mixture stirred in the blender was put into the blow molding machine and direct blow molding was carried out under the same blow molding conditions as described above. The obtained toner bottle was named toner bottle (3-1A). Toner was placed in the toner bottle (3-1A) and left in an operating environment of 50°C for 72 hours. Thereafter, the toner adhering to the inner surface of the toner bottle was removed, and the surface of the toner particles was observed under an electron microscope. As a result, no deformation of the toner particle surface was confirmed, and it was confirmed that no chemical attack had occurred.

[0107] (Examples A8 and A9) Toner bottles (3-2A) and (3-3A) were produced in the same manner as in Example A7, except that the compounding ratio of MR-PP (3-1) and polycarbodiimide master batch was changed as shown in Table 11. Using toner bottles (3-2A) and (3-3A), the occurrence of chemical attack was confirmed in the same manner as for toner bottle (3-1A), and it was confirmed that no chemical attack occurred. [Table 11] The toner bottles (3-1A), (3-2A), and (3-3A) were crushed and melt-kneaded to form first pellets, which were then mixed with second pellets (master batch pellets) of a polycarbodiimide compound prepared in advance before being fed into a molding machine.

[0108] (Example A10) <Production of recycled pellets> A polycarbodiimide compound (trade name: Carbodilite HMV-15CA; manufactured by Nisshinbo Chemical Co., Ltd.) of 0.3% by mass was uniformly added to the flake product prepared in the same manner as in Example A7, and the mixture was melt-kneaded using a twin-screw extruder (manufactured by Ikegai Co., Ltd., PCM-46) at a temperature of 210°C, a screw rotation speed of 200 rpm, vent degassing of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The polycarbodiimide used here was in powder form, and was not a master batch pellet. The obtained recycled pellet was designated MR-PP (4-1).

[0109] <Making blow bottles> MR-PP (4-1) was put into the direct blow molding device and direct blow molding was carried out under the same blow molding conditions as described above. Since polycarbodiimide was added during the extrusion process of MR-PP (4-1), polycarbodiimide was not added when the material was put into the blow molding machine, unlike Examples A7 to A9. The obtained toner bottle was named toner bottle (4-1A).

[0110] (Examples A11 and A12) Pellets of MR-PP (4-2) and (4-3) were prepared in the same manner as for MR-PP (4-1), except that the blending ratio of polycarbodiimide in Example A10 was changed as shown in Table 12. [Table 12]

[0111] Each of the obtained pellets was subjected to direct blow molding under the same conditions as in Example A10 to obtain toner bottles (4-2A) and (4-3A). Toner was placed in each bottle, and the toner particles of the toner adhered to the inner surface of the toner bottle after leaving it at 50° C. for 72 hours were measured. The toner bottle (4-2A) was evaluated as Example A11, and the toner bottle (4-3A) was evaluated as Example A12. As a result, no deformation of the toner particle surface was confirmed in Examples A10 to A12, and it was confirmed that no chemical attack occurred.

[0112] In Examples A10 to A12, the master batch pellets were not prepared, and the carbodiimide compound was added when the crushed product (flakes) of the toner bottle with the toner attached thereto was melt-kneaded and pelletized in an extruder. In this method, the wax and the carbodiimide compound were sufficiently kneaded in the extruder, and the reaction between the wax and the carbodiimide compound was considered to have progressed sufficiently. Therefore, it is considered that the migration of the wax to the inner surface of the toner bottle was sufficiently prevented, and the chemical attack was suppressed. Table 13 shows the evaluation results of chemical attack after molding of the toner bottles of Examples A10 to A12. [Table 13] As described above, polycarbodiimide was added to the toner bottles (4-1A), (4-2A) and (4-3A) in the process of crushing the toner bottles, melt-kneading them and forming pellets.

[0113] (Comparative example A2) <Production of recycled pellets> The flakes prepared in the same manner as in Example A7 were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corporation) at a temperature of 210°C, a screw rotation speed of 200 rpm, vent degassing pressure of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. During melt-kneading, no polycarbodiimide compound was added. The obtained recycled pellets were designated MR-PP (4-4).

[0114] <Making blow bottles> The MR-PP (4-4) was placed in the above-mentioned direct blow molding machine, and direct blow molding was carried out under the same blow molding conditions as described above. The obtained toner bottle was named toner bottle (4-4A). Toner was placed in a toner bottle (4-4A) and left in the usage environment (50°C, 72 hours) to conduct an environmental test. After the test, the toner adhering to the inner surface of the toner bottle was observed by the above-mentioned method, and it was confirmed that the surface of the toner particles had been deformed and that chemical attacks had occurred. [Table 14]

[0115] (Examples B1 to B6, Comparative Example B1) <Manufacturing toner bottles by direct blowing> Using a direct blow molding device, the toner bottles shown in Fig. 7 were manufactured. A was φ76 mm, and B was 150 mm. KEIYO B5804 (product name) manufactured by Keiyo Polyethylene Co., Ltd. was used as the pellet material.

[0116] First, the materials shown in Table 15 below were melt-kneaded and then pelletized to prepare a master batch with a carbon black concentration of 5 mass %. [Table 15]

[0117] Next, the master batch with a carbon black concentration of 5% by mass prepared above and PE were mixed in the ratio shown in Table 16 below, melt-kneaded, and then pelletized to obtain pellets of a resin mixture. [Table 16]

[0118] <Blow molding conditions> The pellets of the resin mixture were fed into a direct blow molding machine (model name: MSE-55E / 54M-AP(E2), Tahara Co., Ltd.) to mold a toner bottle. The screw diameter of the injection molding machine in the molding machine was 50 mm.

[0119] Direct blow molding was performed under the following molding conditions. Extruder screw diameter: 50mm Extruder cylinder temperature: 182℃ -Extrusion rate: 10kg / h Blow pressure: 0.6MPa Cooling time: 15s Mold temperature: 15℃ A toner bottle was produced by the above direct blow molding. This toner bottle is made of virgin PE that has not been recycled. Using the above method, 200 toner bottles were produced using virgin PE.

[0120] (Example B1) <Production of recycled pellets> All of the 200 toner bottles containing virgin PE prepared above were filled with black toner contained in a toner cartridge (product name: Toner NPG-26, manufactured by Canon Inc.). The black toner contained ester wax. Next, the opening of the toner bottle using virgin PE was turned vertically downward to discharge the black toner inside. Even after this operation, a small amount of black toner was still attached to the inner wall of each toner bottle. At this time, the average amount of black toner remaining in the toner bottle for the 200 toner bottles was 0.321% by mass based on the mass of the toner bottle body. Here, the mass of the toner bottle body refers to the mass of the toner bottle and only the toner remaining inside it, after all the supply parts and the like attached to the toner bottle have been removed.

[0121] Next, each of the toner bottles with toner adhering to the inner surface was crushed into pieces of about 5 to 10 mm square using a crusher to obtain crushed products (hereinafter also referred to as flake products). The flake products were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corporation) at a temperature of 200°C, a screw rotation speed of 200 rpm, vent degassing of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The obtained recycled pellets were designated as MR-PE (1-1) (first pellets).

[0122] <Making blow bottles> A polycarbodiimide compound was added to MR-PE (1-1), and direct blow molding was performed under the same blow molding conditions as described above. The polycarbodiimide compound was diluted and prepared in advance as a master batch pellet so that it could be easily mixed uniformly in a blender. Specifically, the polycarbodiimide compound and PE were mixed in the ratio shown in Table 17, melt-kneaded, and then pelletized to prepare a polycarbodiimide master batch pellet (second pellet). [Table 17]

[0123] Before feeding the material into the molding machine, 3.0% by mass of polycarbodiimide master batch pellets (second pellets) were added to MR-PE (1-1) (first pellets) and uniformly stirred in a blender to obtain a pellet mixture. The polycarbodiimide master batch pellets were diluted at the ratio shown in Table 17, so that polycarbodiimide was actually contained at a ratio of 0.3% by mass. The pellet mixture stirred in the blender was subjected to direct blow molding under the same blow molding conditions as described above. The obtained toner bottle was designated toner bottle (1-1B). Toner was placed in the toner bottle (1-1B) and left in an operating environment of 50°C for 72 hours. Thereafter, the toner adhering to the inner surface of the toner bottle was removed, and the surface of the toner particles was observed under an electron microscope. As a result, no deformation of the toner particle surface was confirmed, and no chemical attack occurred. It was confirmed that this was not the case.

[0124] (Examples B2 and B3) Toner bottles (1-2B) and (1-3B) were produced in the same manner as in Example B1, except that the compounding ratio of MR-PE (1-1) and polycarbodiimide master batch was changed as shown in Table 18. Using toner bottles (1-2B) and (1-3B), the occurrence of chemical attack was confirmed in the same manner as for toner bottle (1-1B), and it was confirmed that no chemical attack occurred. [Table 18] The toner bottles (1-1B), (1-2B) and (1-3B) were crushed and melt-kneaded to form first pellets, which were then mixed with second pellets (master batch pellets) of a polycarbodiimide compound prepared in advance before being fed into a molding machine.

[0125] (Example B4) <Production of recycled pellets> A polycarbodiimide compound (trade name: Carbodilite HMV-15CA; manufactured by Nisshinbo Chemical Co., Ltd.) of 0.3% by mass was uniformly added to the flake product prepared in the same manner as in Example B1, and the mixture was melt-kneaded using a twin-screw extruder (manufactured by Ikegai Co., Ltd., PCM-46) at a temperature of 200°C, a screw rotation speed of 200 rpm, vent degassing of -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. The polycarbodiimide used here was in powder form, and was not a master batch pellet. The obtained recycled pellet was designated MR-PE (2-1).

[0126] <Making blow bottles> Direct blow molding was carried out on MR-PE (2-1) under the same blow molding conditions as described above. Since polycarbodiimide was added during the extrusion process of MR-PE (2-1), polycarbodiimide was not added when the material was fed into the blow molding machine, unlike in Examples B1 to B3. The obtained toner bottle was named toner bottle (2-1B).

[0127] (Examples B5 and B6) Pellets of MR-PE (2-2) and (2-3) were prepared in the same manner as for MR-PE (2-1), except that the blending ratio of polycarbodiimide in Example B4 was changed as shown in Table 19. [Table 19]

[0128] Each of the obtained pellets was subjected to direct blow molding under the same conditions as in Example B4 to obtain toner bottles (2-2B) and (2-3B). Toner was placed in each bottle, and the toner was observed for deformation of the toner particle surface of the toner attached to the inner surface of the toner bottle after leaving it at 50°C for 72 hours. Toner bottle (2-2B) was evaluated as Example B5, and toner bottle (2-3B) was evaluated as Example B6. As a result, no deformation of the toner particle surface was confirmed in Examples B4 to B6, and it was confirmed that no chemical attack occurred.

[0129] In Examples B4 to B6, the master batch pellets were not prepared, and the carbodiimide compound was added when the crushed product (flakes) of the toner bottle with the toner attached thereto was melt-kneaded and pelletized in an extruder. In this method, the wax and the carbodiimide compound were sufficiently kneaded in the extruder, and the reaction between the wax and the carbodiimide compound was considered to have progressed sufficiently. Therefore, it is considered that the migration of the wax to the inner surface of the toner bottle was sufficiently prevented, and the chemical attack was suppressed. Table 20 shows the evaluation results of chemical attack after molding of the toner bottles of Examples B4 to B6. [Table 20] As described above, polycarbodiimide was added to the toner bottles (2-1B), (2-2B) and (2-3B) in the process of crushing the toner bottles, melting and kneading them to form pellets.

[0130] (Comparative Example B1) <Production of recycled pellets> The flakes prepared in the same manner as in Example B1 were melt-kneaded using a twin-screw extruder (PCM-46 manufactured by Ikegai Corp.) at a temperature of 200°C, a screw speed of 200 rpm, vent degassing at -0.08 MPa, and a discharge rate of 50 kg / h, and then pelletized. No polycarbodiimide compound was added during the melt-kneading. The obtained recycled pellets were mixed with MR-PE (2 -4).

[0131] <Making blow bottles> The MR-PE (2-4) was subjected to direct blow molding under the same blow molding conditions as described above, and the obtained toner bottle was named toner bottle (2-4B). Toner was placed in a toner bottle (2-4B) and left in the usage environment (50°C, 72 hours) to conduct an environmental test. After the test, the toner adhering to the inner surface of the toner bottle was observed by the above-mentioned method, and it was confirmed that the surface of the toner particles had been deformed and chemically attacked. [Table 21]

[0132] The present disclosure relates to the following methods and compositions: (Method 1) A step of obtaining a blow molded product by blow molding using a resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound. A method for producing a blow molded article, comprising the steps of: (Method 2) The polyethylene or polypropylene is the polyethylene, The method for producing a blow-molded article according to method 1, wherein the polyethylene is at least one selected from the group consisting of high-density polyethylene, low-density polyethylene, and linear low-density polyethylene. (Method 3) the polyethylene or polypropylene is the polypropylene, The method for producing a blow-molded article according to method 1, wherein the polypropylene is at least one selected from the group consisting of a homopolymer, a random copolymer, and a block copolymer. (Method 4) The method for producing a blow-molded article according to any one of Methods 1 to 3, wherein the wax includes an ester wax. (Method 5) The method for producing a blow molded article according to any one of Methods 1 to 4, wherein the blow molded article is a toner bottle. (Method 6) The method for producing a blow molded article according to any one of Methods 1 to 5, wherein the blow molded article is a stretch blow molded article or a direct blow molded article. (Method 7) The step of obtaining the blow molded article comprises: obtaining pellets of the melt-kneaded resin mixture; and performing direct blow molding using the pellets. (Method 8) The step of obtaining the blow molded article comprises: A step of sandwiching the molten kneaded resin mixture between dies and injecting gas into the mold to stretch the resin mixture. The method for producing a blow molded article according to any one of Methods 1 to 5, comprising the steps of: (Method 9) The step of producing the blow molded article comprises: obtaining pellets of the melt-kneaded resin mixture; producing a preform using the pellets; and a step of blow molding the preform. (Method 10) The method for producing a blow molded article according to method 9, wherein the preform has a test tube shape. (Method 11) The step of blow molding the preform comprises: stretching the preform in a longitudinal direction of the preform using a stretching rod; A step of injecting a gas into the inside of the preform to stretch the preform in a circumferential direction; The method for producing a blow molded article according to method 9 or 10, comprising the steps of: (Method 12) The step of producing the blow molded article comprises: melt-kneading the wax and the polyethylene or polypropylene to form first pellets; melt blending the carbodiimide compound and the other polyethylene or polypropylene to form second pellets; mixing the first pellets with the second pellets to obtain a pellet mixture; and blow molding the pellet mixture. A method for producing a blow molded article according to any one of Methods 1 to 5. (Method 13) 13. The method of producing a blow molded article according to method 12, wherein the blow molding step comprises injection molding the pellet mixture. (Method 14) 14. The method for producing a blow-molded article according to any one of Methods 1 to 13, wherein the content of the carbodiimide compound in the resin mixture is 400 to 1500 parts by mass per 100 parts by mass of the wax. (Configuration 15) A resin composition comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound. (Configuration 16) A pellet comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound.

[0133] 3: toner bottle, 21: developing device, 80: image forming device, 60: primary transfer device, 62: intermediate transfer body, 63: paper feeder, 64: secondary transfer section, 68: fixing means, 70: paper discharge tray, 101: injection molding machine, 102: preform mold, 103: preform mold, 104: preform, 105: heating cylinder, 106: preform mouth, 107: heating furnace, 108: blow mold, 109: stretch rod, 110: gas, 112: blow molded product, 207: extrusion screw, 301: direct blow molding machine, 302: direct blow mold, 303: blow pin

Claims

1. A step of obtaining a blow molded product by blow molding using a resin mixture containing at least wax, polyethylene or polypropylene, and a carbodiimide compound. A method for producing a blow molded article, comprising the steps of:

2. The polyethylene or polypropylene is the polyethylene, The method for producing a blow molded article according to claim 1, wherein the polyethylene is at least one selected from the group consisting of high-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

3. the polyethylene or polypropylene is the polypropylene, The method for producing a blow molded article according to claim 1, wherein the polypropylene is at least one selected from the group consisting of a homopolymer, a random copolymer, and a block copolymer.

4. The method for producing a blow molded article according to any one of claims 1 to 3, wherein the wax comprises an ester wax.

5. The method for producing a blow molded article according to any one of claims 1 to 3, wherein the blow molded article is a toner bottle.

6. The method for producing a blow molded article according to any one of claims 1 to 3, wherein the blow molded article is a stretch blow molded article or a direct blow molded article.

7. The step of obtaining the blow molded article comprises: obtaining pellets of the melt-kneaded resin mixture; and performing direct blow molding using the pellets.

8. The step of obtaining the blow molded article comprises: A step of sandwiching the molten kneaded resin mixture between dies and injecting gas into the mold to stretch the resin mixture. The method for producing a blow molded article according to any one of claims 1 to 3, comprising:

9. The step of producing the blow molded article comprises: obtaining pellets of the melt-kneaded resin mixture; producing a preform using the pellets; and blow molding the preform.

10. The method for producing a blow molded article according to claim 9, wherein the preform has a test tube shape.

11. The step of blow molding the preform comprises: stretching the preform in a longitudinal direction of the preform using a stretching bar; A step of injecting a gas into the inside of the preform to stretch the preform in a circumferential direction; The method for producing the blow molded article according to claim 9, comprising:

12. The step of producing the blow molded article comprises: melt-blending the wax and the polyethylene or polypropylene to form first pellets; melt blending the carbodiimide compound and the other polyethylene or polypropylene to form second pellets; mixing the first pellets with the second pellets to obtain a pellet mixture; and blow molding the pellet mixture. A method for producing the blow molded article according to any one of claims 1 to 3.

13. The method of claim 12, wherein the blow molding step comprises injection molding the pellet mixture.

14. The method for producing a blow molded product according to any one of claims 1 to 3, wherein the content of the carbodiimide compound in the resin mixture is 400 to 1500 parts by mass relative to 100 parts by mass of the wax.

15. A resin composition comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound.

16. A pellet comprising a melt-kneaded mixture of wax, polyethylene or polypropylene, and a carbodiimide compound.

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