Resin composition, electrophotographic toner, and hot-melt adhesive

Abstract

To provide an electrophotographic toner and a hot-melt adhesive that enable achievement of performance comparable to that of a conventional wax through use of a post-industrial recycled wax.SOLUTION: A resin composition comprising a post-industrial recycled wax (A) and at least one resin (B) selected from the group consisting of thermoplastic resin and thermosetting resin, wherein a weight ratio [(A) / (B)] of the components (A) and (B) is 0.1 / 99.9 to 50 / 50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, an electrophotographic toner, and a hot melt adhesive containing post-industrial recycled wax. [Background technology]

[0002] Waxes are used in a wide range of fields, such as electrophotographic toners and hot melt adhesives, in combination with various resins. For example, waxes are used in toner applications for image formation by combining them with toner binder resins, and as hot melt adhesives by blending wax with resins that impart desired properties.

[0003] It is known that when a resin composition containing a non-polar wax such as polyethylene wax or polypropylene wax is used in a toner, the occurrence of offset phenomenon is reduced (so-called offset resistance is improved) (Patent Documents 1 and 2).

[0004] The offset phenomenon is a phenomenon in which, when toner transferred from an image developed on a photoreceptor to paper or toner directly attached to paper with a photosensitive layer is brought into contact with a heating body such as a heating roller to fix the toner, some of the toner adheres to the surface of the heating body and is transferred to the subsequent image portion. Adding a non-polar wax such as polyethylene wax or polypropylene wax to the toner is thought to impart releasability from the heating body to the toner, thereby reducing the occurrence of the offset phenomenon.

[0005] Meanwhile, with the need to achieve carbon neutrality and strengthen responses to the problems of marine plastic waste and climate change, promoting plastic recycling is becoming increasingly important. Recycled materials are generally classified into post-consumer recycled materials (hereinafter sometimes abbreviated as PCR) and post-industrial recycled materials (hereinafter sometimes abbreviated as PIR). PCR refers to materials collected or recycled after a product has been used and discarded by consumers, while PIR refers to materials collected or recycled from waste generated during the manufacturing process before the product reaches the consumer. Compared to PCR materials, PIR materials have less variation in quality due to degradation and other factors, making them more likely to produce stable products when used as recycled raw materials.

[0006] A method for producing wax from waste plastics (hereinafter sometimes abbreviated as waste plastics) (Patent Document 3) and a method for using the wax (Patent Document 4) have been proposed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 8-248671 [Patent Document 2] Japanese Patent Application Publication No. 8-114942 [Patent Document 3] Patent No. 5964825 [Patent Document 4] Patent No. 6880051 Summary of the Invention [Problem to be solved by the invention]

[0008] The recycled wax proposed in Patent Documents 3 and 4 is made from recycled plastics, which are PCR materials, and therefore suffer from poorer color and impurity contamination compared to virgin wax, limiting its usage and applications. In particular, when used as electrophotographic toner or hot melt adhesive, the color deterioration and contamination were significant, making it difficult to achieve the target quality.

[0009] Therefore, an object of the present invention is to provide an electrophotographic toner and a hot melt adhesive that use recycled wax produced from waste plastics and that have the same quality as those produced using conventional virgin wax. [Means for solving the problem]

[0010] As a result of extensive research into solving the above-mentioned problems, the present inventors have discovered that by blending PIR wax, obtained by thermally decomposing waste PIR plastics, particularly discarded polyethylene resins, into electrophotographic toners and hot melt adhesives, it is possible to obtain electrophotographic toners and hot melt adhesives that are comparable to those blended with virgin wax, and have thus completed the present invention.

[0011] That is, the embodiments of the present invention are [1] to [8] shown below. [1] A resin composition comprising a post-industrial recycled wax (A) and a resin (B) which is a thermoplastic resin and / or a thermosetting resin, wherein the weight ratio of (A) to (B) [(A) / (B)] is 0.1 / 99.9 to 50 / 50. [2] The resin composition according to [1], wherein the post-industrial recycled wax (A) satisfies the following (i) to (iii): (i) The number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 500 or more and 8,000 or less. (ii) The ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (molecular weight distribution: Mw / Mn) measured by GPC is 1.0 or more and less than 4.0. (iii) The melting point (Tm) measured by differential scanning calorimetry (DSC) is 90°C or higher and 125°C or lower. [3] The resin composition according to [1] or [2], wherein the post-industrial recycled wax (A) is a polyethylene wax. [4] The resin composition according to any one of [1] to [3], wherein the resin (B) is a thermoplastic resin. [5] The resin composition according to any one of [1] to [4], wherein the resin (B) is a polyester resin or a styrene-based polymer. [6] The resin composition according to any one of [1] to [4], wherein the resin (B) is polyethylene or an ethylene-vinyl acetate copolymer. [7] An electrophotographic toner comprising the resin composition according to any one of [1] to [5] and a colorant. [8] A hot melt adhesive comprising the resin composition according to any one of [1] to [4] and [6] and a tackifier, wherein the tackifier is contained in an amount of 5 to 300 parts by mass per 100 parts by mass of the resin composition. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a resin composition, an electrophotographic toner, and a hot melt adhesive that are made from PIR wax as a raw material, and furthermore, it leads to a reduction in waste plastics, and therefore its industrial value is extremely high. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below.

[0014] A resin composition according to one embodiment of the present invention comprises a post-industrial recycled wax (A) and a resin (B) which is a thermoplastic resin and / or a thermosetting resin, and the weight ratio of (A) to (B) [(A) / (B)] is 0.1 / 99.9 to 50 / 50.

[0015] The PIR wax (A) preferably has a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 500 to 8,000, more preferably 500 to 3,000. When the number average molecular weight (Mn) is 500 or more, the viscosity of the resin composition does not decrease, resulting in excellent blocking resistance and abrasion resistance. On the other hand, when the number average molecular weight (Mn) is 8,000 or less, the viscosity of the resin composition does not increase, resulting in good handleability.

[0016] The PIR wax (A) preferably has a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (molecular weight distribution: Mw / Mn) measured by GPC of 1.0 or more and less than 4.0, more preferably 1.0 or more and less than 3.3. When the molecular weight distribution is less than 4.0, the resin composition has improved blocking resistance and good handleability.

[0017] The PIR wax (A) preferably has a melting point of 90° C. or higher and 125° C. or lower, more preferably 100° C. or higher and 115° C. When the melting point is 90° C. or higher, the blocking resistance and handleability of the resin composition are improved, and when the melting point is 125° C. or lower, the viscosity and particle size of the resin composition do not increase, and the handleability is good.

[0018] Next, a method for producing the PIR wax (A) will be described.

[0019] PIR wax (A) is produced by feeding waste PIR plastic into an extruder and thermally decomposing it in the extruder.

[0020] The waste plastic for PIR materials is preferably polyethylene resin, and examples of such waste plastics include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-high molecular weight polyethylene. A mixture of these waste plastics is also acceptable. Furthermore, the plastic is not limited to pellets or powder, but may also be in the form of films, sheets, bottles, fibers, pipes, injection-molded products, and other molded products, as well as their crushed parts. Examples of such waste plastics include used products, non-standard products, and discarded products. Of these, waste polyethylene generated during the extrusion lamination molding process is the most preferred. When the waste plastic is a resin composition, it may be in a state where the components are melted and mixed together, or in a state where the components are physically mixed in the form of solids, such as pellets or scraps.

[0021] PIR waste plastics can be used as they are, with antioxidants added during manufacturing or when they are molded into products such as film.Furthermore, antioxidants can be added to prevent oxidative degradation during the thermal decomposition reaction, and the thermal decomposition reaction can also be carried out.

[0022] The extruder is not particularly limited, and examples thereof include a single-screw extruder, a co-rotating twin-screw extruder, a counter-rotating twin-screw extruder, a multi-screw extruder such as a four-screw or eight-screw extruder in which three or more screws are arranged in parallel in the cylinder of the extruder, and a tandem extruder in which two or more extruders are connected in series, an extruder in which the outlet of one extruder is connected to the inlet of the other extruder and arranged in an L-shape, an extruder in which the outlet of one extruder is connected to the side of the other extruder and arranged in a T-shape, etc. Furthermore, examples of the extruders constituting the tandem extruder include a single-screw extruder or a multi-screw extruder with two to eight screws, and two or more of these extruders can be combined to form a tandem extruder. Among these extruders, a co-rotating twin screw extruder, a 4- to 8-screw multi-screw extruder, or a tandem extruder is preferred because it can produce a PIR wax (A) of particularly stable quality and has excellent stability in torque and discharge rate during extrusion. These extruders are preferably equipped with a side feeder for adding a modifier.

[0023] The extruder is preferably equipped with a vacuum vent port to efficiently discharge pyrolyzed low-molecular-weight gas components outside the extruder. Furthermore, the ratio (L / D) of screw length (L) to screw diameter (D) is preferably 30 or more, particularly 40 or more, so that the pyrolysis of waste plastic can be efficiently carried out and PIR wax (A) of stable quality can be obtained.

[0024] The conditions for pyrolysis of waste plastics after feeding them into the extruder should be adjusted appropriately depending on the molecular weight of the desired pyrolysis wax, but since pyrolysis can be carried out in a short time and the odor of the resulting pyrolysis wax can be easily suppressed, the cylinder temperature in the pyrolysis zone can be in the range of 330 to 480°C, more preferably 350 to 460°C, and particularly preferably 380 to 450°C. The residence time in the pyrolysis zone can be in the range of 0.5 to 30 minutes, more preferably 1 to 20 minutes, and particularly preferably 1.5 to 15 minutes.

[0025] In order to suppress the odor of the resulting PIR wax (A) and to facilitate control of the molecular weight and degree of modification, it is preferable to replace the atmosphere inside the extruder with an inert gas such as hydrogen, helium, argon, nitrogen, or carbon dioxide during pyrolysis, and nitrogen gas is particularly preferable. The wax extruded from the extruder can be pelletized by methods such as hot cutting, mist cutting, or underwater cutting, or by cooling on a steel belt and then cutting.

[0026] The PIR wax (A) can be used in any form such as pellets, powder, flakes, granules, grains, or paste.

[0027] In the present invention, resin (B) is a resin made of a thermoplastic resin and / or a thermosetting resin. Examples of the thermoplastic resin include olefin resins, styrene resins, thermoplastic polyester resins, polyamides, polycarbonates, polyacetals, polyphenylene oxides, polyimides, polyvinyl alcohols, polyvinyl acetates, acrylic resins, rosin resins, alkyd resins, coumarone resins, ketone resins, cellulose resins, chlorinated polyolefins, and mixtures thereof.

[0028] Examples of the thermosetting resin include polyurethane, epoxy resin, thermosetting unsaturated polyester resin, urea resin, melamine resin, phenolic resin, and mixed resins thereof.

[0029] The resin (B) may consist of one kind of these thermoplastic resins and thermosetting resins alone, or may consist of a combination of two or more kinds.

[0030] The thermoplastic resin or thermosetting resin may contain fibers or organic fillers as long as the object of the present invention is not impaired.

[0031] The definitions and manufacturing methods of thermoplastic resins and thermosetting resins are well known and are described in publications such as "Practical Plastics Encyclopedia" (Practical Plastics Encyclopedia Editorial Committee, published by Sangyo Chosakai Co., Ltd.).

[0032] Resin (B) is preferably a thermoplastic resin. Since PIR wax (A) and resin (B) are mixed at high temperatures (e.g., 100°C or higher), using a thermoplastic resin for resin (B) prevents curing of resin (B) during mixing and makes it easier to uniformly disperse PIR wax (A) in resin (B).

[0033] Resin (B) may be graft-copolymerized with a polar monomer, if necessary. Examples of the polar monomer include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, epoxy group-containing ethylenically unsaturated compounds, unsaturated carboxylic acids and their anhydrides and derivatives, and vinyl ester compounds.

[0034] [Resin (B) when the resin composition is used for toner] When the resin composition is used as a toner, resin (B) corresponds to a toner binder resin. Various known binder resins can be used as resin (B) for toner. Specific examples include polyester resins such as styrene polymers, ketone resins, maleic acid resins, aliphatic polyester resins, aromatic polyester resins, and aliphatic-aromatic polyester resins, coumarone resins, phenolic resins, epoxy resins, terpene resins, and amorphous resins such as polyvinyl butyral, polybutyl methacrylate, polyvinyl chloride, polyethylene (provided that Mw is higher than 1500), polypropylene, polybutadiene, and ethylene-vinyl acetate copolymers.

[0035] These toner binder resins can be used alone or in combination of two or more. Among the above toner binder resins, at least one resin selected from the group consisting of polyester resins and styrene polymers is preferred, and styrene polymers are particularly preferred, in that they have an appropriate softening point of around 100°C and exhibit good fixing properties.

[0036] The styrene polymer may be, for example, a homopolymer or copolymer consisting of only a styrene monomer, or a copolymer of a styrene monomer and another vinyl monomer, etc. Examples of the styrene monomer include styrene, p-chlorostyrene, vinylnaphthalene, etc.

[0037] Examples of the other vinyl monomers include ethylenically unsaturated monoolefins such as ethylene, propylene, 1-butene, and isobutene; vinyl halides such as vinyl chloride, vinyl bromide, and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; α-methylene aliphatic monocarboxylic acids such as acrylic acid and methacrylic acid; esters of α-methylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. nitriles or amides such as acrylonitrile, methacrylonitrile, acrylamide, etc.; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl isobutyl ether, etc.; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, etc.; N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone, etc.; itaconate esters such as dimethyl itaconate, dipropyl itaconate, dibutyl itaconate, dioctyl itaconate, diamyl itaconate, etc.; and other compounds such as maleic esters and fumaric esters may also be used, but are not limited to these.

[0038] Among these vinyl monomers, esters of α-methylene aliphatic monocarboxylic acids are preferred.

[0039] The styrene polymer can be produced by a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization.

[0040] [Resin (B) when the resin composition is used for hot melt adhesive applications] When the resin composition is used as a hot melt adhesive, the resin (B) may be a polymer that is commonly used in hot melt adhesives, and examples thereof include the following.

[0041] 1) Polyethylene (however, Mw: higher than 1500) 2) Ethylene-vinyl acetate copolymer (EVA) 3) Modified EVA polymers such as saponified EVA and graft-modified EVA 4) Ethylene (meth)acrylate copolymers such as ethylene (meth)ethyl acrylate (EEA) (however, Mw: higher than 1500) 5) Ionomer resins obtained by partially neutralizing ethylene-(meth)acrylic acid copolymers. Specific examples include those marketed by Mitsui DuPont Polychemicals under the trade name Himilan.

[0042] 6) Ethylene-propylene copolymer or ethylene-propylene-(meth)acrylic acid terpolymer (Mw: higher than 1500) 7) Polyamide: A reaction product of a dibasic acid and a diamine, such as a reaction product of a dimer of a fatty acid such as soybean oil, tung oil, or tall oil, with an alkyldiamine such as ethylenediamine or diethylenetriamine, or nylons such as nylon 12. Specific examples of these include DAIAMID (registered trademark) (Daicel Chemical Industries), PLATILON (Toa Gosei Chemical Industry), and AMILAN (Toray).

[0043] 8) Polyester: For example, Ester Resin 200 and 300 (Toyobo), Vita 1200, 300 (Goodyear), etc.

[0044] 9) Propylene-based polymers: atactic polypropylene, propylene-α-olefin copolymers with 4 or more carbon atoms, etc.

[0045] 10) Copolymers of vinyl aromatic compounds and conjugated diene compounds, and their hydrogenated products: Specific examples include styrene-butadiene random copolymers, styrene-isoprene random copolymers, butadiene-polystyrene block copolymers, polystyrene-polyisoprene block copolymers, polystyrene-polyisoprene-polystyrene triblock copolymers, polystyrene-polybutadiene-polystyrene triblock copolymers, poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene) triblock copolymers, and hydrogenated products thereof.

[0046] As the resin (B), 1) polyethylene, 2) ethylene-vinyl acetate copolymer (EVA), 6) ethylene-propylene copolymer, 6) ethylene-propylene-(meth)acrylic acid terpolymer, and 9) propylene-based polymer are preferred, and from the viewpoint of compatibility with the PIR wax (A), 1) polyethylene and 2) ethylene-vinyl acetate copolymer (EVA) are particularly preferred.

[0047] These resins (B) are commercially available. Examples of resins (B) include Cariflex TR-1101, TR-1107, and TR-4113 (manufactured by Shell Chemical Co.), Kraton G-6500, G-6521, G-1650, G-1652, and G-1657 (manufactured by Shell Chemical Co.), Sorbrene and hydrogenated Sorbrene (manufactured by Phillips), and Affinity GA1900 and GA1950 (manufactured by The Dow Chemical Company). Resins (B) may be used singly or in combination of two or more.

[0048] In the resin composition, the mass ratio of the PIR wax (A) to the resin (B) [(A) / (B)] is 0.1 / 99.9 to 50 / 50, preferably 1 / 99 to 50 / 50, more preferably 2 / 98 to 30 / 70, and even more preferably 8 / 92 to 25 / 75. When the mass ratio is 0.1 / 99.9 to 50 / 50, the resin composition is likely to achieve both good handleability and a reduced deformation initiation temperature during heating.

[0049] When the resin composition is used in a toner, the mass ratio of the PIR wax (A) to the resin (B) [(A) / (B)] is preferably 0.1 / 99.9 to 30 / 70. The lower limit of the PIR wax (A) mass ratio is preferably 0.5 / 99.5, more preferably 1.0 / 99.0, particularly preferably 1.5 / 98.5, and most preferably 2.0 / 98.0. The upper limit of the PIR wax (A) mass ratio is preferably 25 / 75, more preferably 15 / 85, particularly preferably 10 / 90, and most preferably 6 / 94. If the mass ratio [(A) / (B)] is less than 0.1 / 99.9, the toner may have insufficient offset resistance and storage stability. If the mass ratio [(A) / (B)] exceeds 30 / 70, the fixing property and, in particular, the fixing stability over time after printing will be insufficient, meaning that the letters will be prone to peeling off from the paper surface.

[0050] When the resin composition is used in a hot melt adhesive, the mass ratio of the PIR wax (A) to the resin (B) [(A) / (B)] is preferably 1 / 99 to 50 / 50. In order to reduce the melt viscosity while maintaining good adhesiveness, the mass ratio is more preferably 15 / 85 to 45 / 55.

[0051] The resin composition may further contain additives such as other thermoplastic resins, weathering stabilizers, heat stabilizers, antistatic agents, antislip agents, antiblocking agents, antifogging agents, nucleating agents, lubricants, pigments, organic fillers, inorganic fillers, fibers, fillers, dyes, plasticizers, antioxidants, hydrochloric acid absorbers, antioxidants, and copper inhibitors, as needed, provided that the objectives of the present invention are not impaired. Examples of fibers include glass fiber, carbon fiber, natural fibers (wood flour, wood fiber, bamboo, cotton, cellulose, nanocellulose fibers, etc.), and agricultural fibers (straw, hemp, flax, kenaf, kapok, jute, ramie, sisal, henequen, corn fiber, coir, nut shells, rice husks, etc.). Examples of organic fillers include lignin, starch, and products containing them.

[0052] The type of glass fiber is not particularly limited, but it is possible to use roving glass, chopped strand glass, milled glass, etc. These may be used alone or in combination of two or more types.

[0053] The carbon fiber is not particularly limited in shape or type, and may be in the form of chopped strand, roving strand, milled fiber, etc., and may be either pitch-based or polyacrylonitrile-based. In addition to those obtained by spinning or molding these raw material compositions and then carbonizing them, it is also possible to use carbon fibers obtained by vapor growth methods that basically do not involve a spinning step.

[0054] Examples of fillers that can be used include amorphous fillers such as calcium carbonate, silica, kaolin, clay, titanium oxide, barium sulfate, zinc oxide, aluminum hydroxide, alumina, and magnesium hydroxide; plate-like fillers such as talc, mica, and glass flakes; needle-like fillers such as wollastonite, potassium titanate, basic magnesium sulfate, sepiolite, xonotlite, and aluminum borate; metal powders, metal flakes; and fillers such as carbon black and carbon particles. Other examples include glass beads and glass powder. These fillers may be used alone or in combination, or their surfaces may be carbon-coated or silane-coupling-treated, and used alone or in combination.

[0055] The resin composition can be produced by dry blending or melt blending using any method. Specifically, for example, the PIR wax (A), resin (B), and other optional components can be blended simultaneously or in any order using a tumbler, V-blender, Nauta mixer, Banbury mixer, kneading roll, single-screw or twin-screw extruder, or the like. Alternatively, the PIR wax (A), resin (B), and other optional components can be dispersed or dissolved in a solvent and then blended by drying using an appropriate method, such as natural drying or forced heating.

[0056] <Electrophotographic toner> An electrophotographic toner according to one embodiment of the present invention comprises the resin composition and a colorant.

[0057] In addition to the resin composition and colorant, the electrophotographic toner may further contain a charge control agent, a release agent, a pigment dispersant, etc., as required.

[0058] Examples of colorants include known black pigments such as carbon black, acetylene black, lamp black, and magnetite; known inorganic pigments such as yellow lead, yellow iron oxide, titanium oxide, and zinc white; and known organic pigments such as Hansa Yellow G, Quinoline Yellow Lake, Permanent Yellow NCG, Molybdenum Orange, Vulcan Orange, Indanthrene, Brilliant Orange GK, Bengala, Brilliant Carmine 6B, Frizarin Lake, Methyl Violet Lake, Fast Violet B, Cobalt Blue, Alkali Blue Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, and Malachite Green Lake. The content of the colorant is usually preferably 5 to 250 parts by mass per 100 parts by mass of the resin composition.

[0059] If necessary, the electrophotographic toner may contain a conventional release agent, such as polyvinyl chloride, polyvinyl acetate, polyolefin, polyester, polyvinyl butyral, polyurethane, polyamide, rosin, modified rosin, terpene resin, phenolic resin, aliphatic hydrocarbon resin, aromatic petroleum resin, paraffin wax, polyolefin wax (excluding the PIR wax (A) of the present invention), ceramic wax, rice wax, sugar wax, urushi wax, beeswax, natural waxes such as carnauba wax, candelilla wax, and montan wax, fatty acid amide wax, PVC resin, styrene-butadiene resin, chroman-indene resin, or melamine resin, within the range that does not impair the effects of the present invention. The amount of the release agent is preferably 0.1 to 40 parts by mass per 100 parts by mass of the resin composition.

[0060] Examples of monomers constituting the polyolefin wax (excluding PIR wax (A)) include ethylene, propylene, 1-butene, 1-pentene, and all other olefin monomers. Polyolefin waxes obtained from these monomers may be homopolymers obtained from a single monomer, or copolymers obtained from two or more monomers. The polyolefin waxes may be either unmodified polyolefin waxes or modified polyolefin waxes in which a modifying component is blocked or grafted onto the olefin component. Examples of modifying components in modified polyolefin waxes include aromatic monomers such as styrene, methylstyrene, p-ethylstyrene, and pn-butylstyrene; monocarboxylic acid ester monomers such as methyl (meth)acrylate and ethyl (meth)acrylate; dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, crotonic acid, and methylhexahydrophthalic acid; and anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, allylsuccinic anhydride, glutaconic anhydride, and nadic anhydride.

[0061] As the charge control agent, known charge adjusting agents such as nigrosine, quaternary ammonium salts, and metal-containing azo dyes can be appropriately selected and used, and the amount used is preferably 0.1 to 10 parts by mass, which is the usual amount, per 100 parts by mass of the resin composition.

[0062] The electrophotographic toner can be produced by dispersing the above-mentioned components in any conventionally known manner, such as contact dispersion, melt dispersion, or solution dispersion.

[0063] For example, when an electrophotographic toner is produced by melt dispersion, the PIR wax (A), the resin (B) used as a toner binder resin, a colorant, a charge control agent, a release agent, and the like are premixed in advance in a mixer such as a ball mill or a Henschel mixer, and then kneaded in a heated, molten state using a thermal kneader such as a hot roll kneader or a single-screw or twin-screw kneader. After cooling, the mixture is finely pulverized using a fine pulverizer such as a hammer mill, and further classified using an air classifier. Usually, particles having a diameter in the range of 8 to 20 μm are collected to produce the toner.

[0064] The heat-melting conditions when kneading with the twin-screw thermal kneader vary depending on the physical properties, such as the melting point, of the resin (B) used as the toner binder resin. For example, in the case of a polar group-containing vinyl polymer such as a styrene-acrylic resin, the resin temperature at the discharge port of the twin-screw kneader is preferably less than 190°C and the residence time is preferably less than 180 seconds. Furthermore, the cooling method is preferably rapid cooling using a steel belt cooler or the like.

[0065] One method for carrying out the above kneading is to prepare a masterbatch by kneading the PIR wax (A) with the resin (B) used as the toner binder resin under conditions where the content of the PIR wax (A) is high, and then kneading this with other components such as the toner binder resin and colorant. This method is effective when the resin (B) used as the toner binder resin and the PIR wax (A) are relatively difficult to mix.

[0066] When preparing the masterbatch, the PIR wax (A) is contained in an amount of 5 to 900 parts by mass, preferably 5 to 300 parts by mass, more preferably 5 to 100 parts by mass, and particularly preferably 5 to 50 parts by mass, per 100 parts by mass of the resin (B) used as the binder resin for the toner.

[0067] Alternatively, the electrophotographic toner can also be produced by a method including a mixing step of mixing a resin particle dispersion in which resin particles are dispersed in a dispersant, a colorant dispersion in which colorant particles are dispersed in a dispersant, and a release agent particle dispersion in which PIR wax (A) particles are dispersed in a dispersant, etc.; an aggregation step of forming aggregated particles corresponding to the toner particle size; and a fusion step of fusing the aggregated particles by heating.

[0068] The toner of the present invention can also be produced by a method including a step of polymerizing a composition comprising a polymerizable monomer, a colorant, the PIR wax (A), a charge control agent, and the like.

[0069] The use of electrophotographic toner is not particularly limited, but it can also be used as a developer by mixing it with a carrier. Any conventionally known carrier can be used as the carrier. Examples of the carrier include magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, and the like, or those whose surfaces are treated with resin or the like.

[0070] Examples of resins that can be used to coat the carrier surface include styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, acrylic acid ester copolymers, methacrylic acid ester copolymers, fluorine-containing resins, silicon-containing resins, polyamide resins, ionomer resins, polyphenylene sulfide resins, and mixtures thereof.

[0071] <Hot melt adhesive> A hot melt adhesive according to one embodiment of the present invention comprises the resin composition and a tackifier.

[0072] The tackifier is blended to adjust the viscosity of the resin (B) contained in the resin composition when melted and to improve hot tack and wettability. Examples of tackifiers include aliphatic hydrogenated tackifiers, rosin, modified rosin, or esters thereof, aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins of aliphatic and aromatic components, low-molecular-weight styrene-based resins, isoprene-based resins, alkylphenol resins, terpene resins, and coumarone-indene resins. Tackifiers may be used alone or in combination of two or more.

[0073] The tackifier can be appropriately selected depending on the resin (B) contained in the resin composition. For example, when an ethylene-vinyl acetate copolymer (EVA) is used as the resin (B), it is preferable to use an aromatic hydrocarbon resin, an alicyclic petroleum resin, or a (modified) rosin.

[0074] The content of the tackifier is preferably 5 to 300 parts by mass per 100 parts by mass of the resin composition, and more preferably 50 to 200 parts by mass in order to facilitate the development of adhesive strength while maintaining an appropriate melt viscosity.

[0075] The hot melt adhesive may further contain an unmodified polyolefin such as Sasol Wax (H-1, manufactured by Sasol Corporation), which is typically blended into hot melt adhesives. This reduces the melt viscosity of the hot melt adhesive and further improves workability.

[0076] The hot melt adhesive may contain various additives, such as softeners, weather resistance stabilizers, heat resistance stabilizers, antistatic agents, antislip agents, antiblocking agents, antifogging agents, nucleating agents, lubricants, pigments, fillers, dyes, plasticizers, antioxidants, hydrochloric acid absorbers, antioxidants, and copper inhibitors, as needed, provided that the object of the present invention is not impaired.

[0077] The hot melt adhesive can be obtained by feeding the above components to a mixer such as a Brabender, heating to melt and mix them, and then molding them into the desired shape, such as granules, flakes, or rods.

[0078] Hot melt adhesives are used, for example, by heating and melting them and applying them to a substrate such as cloth, kraft paper, aluminum foil, or polyester film in a conventional manner to form a hot melt adhesive layer. [Example]

[0079] EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these. (1) Evaluation method for PIR wax 1) GPC measurement Apparatus: HLC (registered trademark)-8321GPC / HT (detector: RI method) (manufactured by Tosoh Corporation) Columns: One column of (i) and three columns of (ii) below are used in series. (i) TSKgel® guardColumuH(HR)(30)HT (7.5mm I.D.) x 7.5cm) (Tosoh Corporation) x 1 (ii) TSKgel® GMH(HR)-H(20)HT (7.5mm I.D.) x 30cm) (Tosoh Corporation) x 3 Eluent: 1,2,4-trichlorobenzene (containing 0.05 wt% BHT) (Purchased from Fujifilm Wako Pure Chemical Industries, Ltd.) Flow rate: 1.0mL / min Injection volume: 0.3mL Column temperature: 140℃ System temperature: 40°C Sample concentration: 1 mg / mL Calibration curve: quintic approximation curve using standard polystyrene manufactured by Tosoh Corporation. However, the molecular weight was converted to PE equivalent molecular weight using the Q factor.

[0080] 2) Melting point measurement Measurements were taken in accordance with JIS K7122 (2012).

[0081] The melting point of PIR wax was measured by differential scanning calorimetry (DSC) using a DSC7000X (Hitachi High-Tech Science). Approximately 10 mg of sample was sealed in an aluminum pan and heated from -20°C to 200°C at a rate of 10°C / min. The endothermic peak of the resulting curve was determined as the melting point. Prior to this temperature measurement, the sample was first heated to approximately 200°C, held there for 5 minutes, and then cooled to -20°C at a rate of 20°C / min to standardize the thermal history of the sample. (2) Evaluation method for electrophotographic toner 1) Toner storage stability The toner sample was placed in a sealed container and left in a thermostatic water bath maintained at 50°C for 24 hours, then removed and the state of blocking of the toner was visually evaluated according to the following criteria.

[0082] ○: No blocking occurs ×: Blocking occurs 2) Toner fixation An adhesive tape was attached to the obtained copy, and after the adhesive tape was peeled off, the amount of image remaining on the tape was visually evaluated according to the following criteria.

[0083] ○: No adhesion at all ×: Partial adhesion 3) Offset resistance The degree of toner contamination of the fixing roller was visually observed and evaluated according to the following criteria.

[0084] ○: Non-staining ×: Stains occur (3) Evaluation method for hot melt adhesive composition 1) Melt viscosity (normal use temperature) The melt viscosity at 180°C was measured using a Brookfield viscometer. 10 g of sample was placed in the apparatus heated to 180°C, and the measurement was started after 10 minutes of melting. A No. 31 rotor was used, and the viscosity (mPa·s) was read after 20 minutes at 5 revolutions per minute.

[0085] (Evaluation criteria) ○: Less than 3,000 mPa·s △: 3,000~4,000mPa·s ×: Over 4,000 mPa·s 2) Heat resistant adhesion (How to prepare adhesive test specimens) The hot melt adhesive composition was tested using a hot melt open time tester (manufactured by Asahi Chemical Synthetic Co., Ltd.) at a coating temperature of 180°C and a coating amount of 0.03 g / cm. 2 The adhesive was applied at a coating speed of 7.5 m / min, an open time of 2 seconds, and a press load of 2 kg (size: 50 mm x 100 mm). (Adhesion test substrate) The adherend used was general-purpose cardboard (K-liner).

[0086] (Method for measuring heat resistance adhesion (peel adhesion failure time)) The test specimens prepared using the adhesive test specimen preparation method were cut to a size of 25 mm x 100 mm to form substrates in a T-type peel state. A 300 g / 25 mm load was hung from the specimens and they were placed in an oven set at 65°C. The time it took for the adhesive on the substrate to fail due to the weight being too strong to withstand the weight (the weight fell) was evaluated as the peel adhesion failure time.

[0087] (Evaluation criteria) ○: 80 minutes or more ×: Less than 80 minutes 3) Solidification rate The hot melt adhesive composition was placed in a 100 ml test tube (2.5 cm diameter) and heated using a heater set to 180°C. After leaving to stand for 10 minutes, the dissolved contents were stirred gently with a thin spatula for 1 minute. A thermometer was then inserted into the composition, and the internal temperature was raised to 170°C. The test tube was then quickly removed, and while it was allowed to cool, the internal temperature was read at the moment the bottom of the test tube turned cloudy. During cooling, the test tube was fixed 1 cm from the bottom of a 500 ml beaker to prevent localized cooling due to air currents.

[0088] (Evaluation criteria) Cloudy temperature ○ : Above 118°C × : Below 118°C <Production Example of PIR Wax> [Production Example 1] As an extruder, a co-rotating meshing type twin-screw extruder with a screw diameter of 11 mm and a ratio of screw length L to screw diameter D (L / D) of 40 was used. As the waste plastic, polyethylene (number average molecular weight 15,000) of the used PIR material generated at the time of resin switching in the extrusion lamination molding of low-density polyethylene (Petrosen (registered trademark) 205 manufactured by Tosoh Corporation) was used. It was pulverized and volume-reduced to an average particle size of 10 mm or less by a pulverizer, and was charged from the main feeder of the extruder together with nitrogen gas at a constant flow rate at a supply rate of 20 g / hr, and was thermally decomposed by melt-kneading under the condition that the cylinder temperature in the thermal decomposition region of the extruder was heated to 450°C and the cooling region was heated to 200°C. Next, the melt-kneaded product was extruded onto a steel plate placed in a nitrogen atmosphere, cooled, and then pulverized to obtain powdery PIR wax. And as a result of performing GPC measurement using the obtained PIR wax (A-1), the number average molecular weight (Mn) was 1,500, the molecular weight distribution (Mw / Mn) was 3.0, and the melting point (Tm) was 108°C.

[0089] [Production Example 2] As the waste plastic, polyethylene (number average molecular weight 13,000) of the used PIR material, which is the end material of the laminated film of low-density polyethylene (Petrosen (registered trademark) 203 manufactured by Tosoh Corporation), was used, and PIR wax was obtained in the same manner as in Example 1. The analysis results of the obtained PIR wax (A-2) are shown in Table 1.

[0090] <Production Example of Toner Binder> A four-neck separable flask equipped with a condenser, stirrer, thermometer, and nitrogen inlet tube was charged with a mixture of 70 parts styrene, 25 parts n-butyl acrylate, 5 parts monobutyl maleate, 0.5 parts maleic acid-modified polyvinyl alcohol, 40 ppm divinylbenzene as a molecular weight modifier, 0.4 parts 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane as a polymerization initiator, and a specified amount of ion-exchanged water. The mixture was kept at 60°C for 1 hour, then heated to 85°C and polymerized for 8 hours. 20 ppm benzoyl peroxide was added, and the temperature was further raised to 95°C and maintained for 4 hours to complete the polymerization. The mixture was then cooled to room temperature, thoroughly washed with water, and dried to obtain a styrene-acrylic copolymer for toner binder resin. The resulting resin had a weight-average molecular weight of 130,000 and a glass transition temperature of 64°C. Furthermore, when the particle size of the obtained resin was measured using a laser diffraction particle size distribution analyzer (SALD3000S manufactured by Shimadzu Corporation), sharp particles with an average particle size of 110 μm and a particle size distribution uniformity of 0.4 were obtained.

[0091] <Toner production example and evaluation results> [Example 1] 100 parts of the resulting toner binder resin, 5 parts of carbon black (MA-100 manufactured by Mitsubishi Chemical Industries), 1 part of PIR wax (A-1), and 1 part of charge control agent (Bontron S34 manufactured by Orient Chemical Industries) were coarsely pulverized in a Henschel mixer and then finely pulverized in a jet mill to obtain a black toner with an average particle size of 13 μm. 50 g of this toner was mixed with 950 g of iron powder carrier (EF300-500 manufactured by Nippon Iron Powder Co., Ltd.) to prepare a developer. The storage stability of this developer was evaluated using the method described below, and no blocking was observed. Images were printed using this developer in an electrophotographic copier (Fuji Xerox 3200). The fixation temperature of the copied image was varied using a temperature-adjustable heating roller, and the fixation initiation temperature was measured at 140°C. Further increasing the temperature, offsetting occurred at 175°C. The adhesion of the fixed image obtained within this temperature range was evaluated using adhesive tape and found to be good. The evaluation results of storage stability, fixability, and offset resistance are shown in Table 2.

[0092] [Example 2] A toner was obtained in the same manner as in Example 1, except that the PIR wax (A-2) obtained in Production Example 2 was used instead of the PIR wax (A-1) used in Example 1. The evaluation results of the obtained toner are shown in Table 2.

[0093] [Comparative Example 1] A toner was obtained in the same manner as in Example 1, except that a polyethylene wax with the trade name Sanwax (registered trademark)-171P (manufactured by Sanyo Chemical Industries, Ltd., physical properties are shown in Table 1) was used instead of the PIR wax (A-1) used in Example 1. The evaluation results of the obtained toner are shown in Table 2.

[0094] Comparative Example 2 A toner was obtained in the same manner as in Example 1, except that a low molecular weight polyethylene (trade name: Hiwax 220P, manufactured by Mitsui Chemicals, Inc., physical properties are shown in Table 1) was used instead of the PIR wax (A-1) used in Example 1. The evaluation results of the obtained toner are shown in Table 2. <Production Examples and Evaluation Results of Hot Melt Adhesive Compositions> [Example 3] A hot melt composition was obtained by blending 40 parts by mass of an ethylene-vinyl acetate copolymer (trade name Ultrathene (registered trademark) 722, manufactured by Tosoh Corporation) as resin (B), 40 parts by mass of a hydrogenated petroleum resin (Arcon (registered trademark) M-115, manufactured by Arakawa Chemical Industries, Ltd.) as a tackifier, and 20 parts by mass of the PIR wax (A-1) obtained in Production Example 1, and kneading the mixture in an autoclave at 180°C for 15 minutes. The evaluation results of the obtained hot melt adhesive composition are shown in Table 3.

[0095] [Example 4] A hot melt composition was obtained in the same manner as in Example 2, except that the PIR wax (A-2) obtained in Production Example 2 was used instead of the PIR wax (A-1) used in Example 3. The evaluation results of the obtained hot melt adhesive composition are shown in Table 3.

[0096] Comparative Example 3 A hot melt composition was obtained in the same manner as in Example 3, except that a low molecular weight polyethylene (trade name: Sanwax (registered trademark)-171P, manufactured by Sanyo Chemical Industries, Ltd., physical properties are shown in Table 1) was used instead of the PIR wax (A-1) used in Example 3. The evaluation results of the obtained hot melt adhesive composition are shown in Table 3.

[0097] Comparative Example 4 A hot melt composition was obtained in the same manner as in Example 3, except that a low molecular weight polyethylene (trade name: Hiwax 220P, manufactured by Mitsui Chemicals, Inc., physical properties are shown in Table 1) was used instead of the PIR wax (A-1) used in Example 3. The evaluation results of the obtained hot melt adhesive composition are shown in Table 3.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3] [Industrial Applicability]

[0101] PIR wax, produced by simply and efficiently pyrolyzing waste PIR plastics, can reduce waste plastics and, when blended with thermoplastic resins and / or thermosetting resins, can provide excellent electrophotographic toners and hot melt adhesives.

Claims

1. A resin composition comprising a post-industrial recycled wax (A) and a resin (B) which is a thermoplastic resin and / or a thermosetting resin, wherein the weight ratio of (A) to (B) [(A) / (B)] is 0.1 / 99.9 to 50 / 50.

2. The resin composition according to claim 1, wherein the post-industrial recycled wax (A) satisfies the following (i) to (iii): (i) The number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 500 or more and 8,000 or less. (ii) The ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (molecular weight distribution: Mw / Mn) measured by GPC is 1.0 or more and less than 4.

0. (iii) The melting point (Tm) measured by differential scanning calorimetry (DSC) is 90°C or higher and 125°C or lower.

3. The resin composition according to claim 1, wherein the post-industrial recycled wax (A) is a polyethylene wax.

4. The resin composition according to claim 1 , wherein the resin (B) is a thermoplastic resin.

5. The resin composition according to claim 1, wherein the resin (B) is a polyester resin or a styrene-based polymer.

6. The resin composition according to claim 1, wherein the resin (B) is polyethylene or an ethylene-vinyl acetate copolymer.

7. 6. An electrophotographic toner comprising the resin composition according to claim 1 and a colorant.

8. A hot melt adhesive comprising the resin composition according to any one of claims 1 to 4 and 6, and a tackifier, wherein the tackifier is contained in an amount of 5 to 300 parts by mass per 100 parts by mass of the resin composition.

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