Aqueous surface treatment agent, method for producing the same, surface treatment method, and elastomer article

Abstract

To provide an aqueous surface treatment agent and a method for producing the same, capable of achieving reduction of tackiness and a low friction coefficient of an article without using a fluorine-based surface treatment agent or a silicone-based surface treatment agent, and having little load on the environment and no problem of contact failure, a surface treatment method of an elastomer article, and an elastomer article having a surface treatment layer formed by surface treatment using the aqueous surface treatment agent.SOLUTION: An aqueous surface treating agent which is a dispersion liquid of an aqueous solvent containing polyurethane resin particles as a component (A), ultra-high molecular weight polyethylene particles having a mass average molecular weight of 1,000,000 or more as a component (B), and an acetylene-based surfactant as a component (C), a method for producing the same, a method for surface-treating an elastomer article using the aqueous surface treating agent, and an elastomer article having a surface-treated layer formed by surface treatment using the aqueous surface treating agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aqueous surface treatment agent and a method for producing the same, a method for treating the surface of an elastomer article using the aqueous surface treatment agent, and an elastomer article. [Background technology]

[0002] Conventionally, a method of applying a surface treatment agent to the surface of an elastomer article has been known for the purpose of reducing the stickiness of the elastomer article or improving its sliding properties (lowering the coefficient of friction). For example, a fluorine-based surface treatment agent or a silicone-based surface treatment agent has been applied to the surface of an article such as a rubber material in order to reduce the stickiness or improve the sliding properties.

[0003] As a specific example, Patent Document 1 describes a paint containing a water-soluble urethane resin, ultra-high molecular weight polyethylene particles, and fluorine-based resin particles. This paint is used to form a lubricating coating that improves the wear resistance of plastic sliding members.

[0004] Patent Document 2 describes a coating agent containing a base resin such as a water-based urethane resin and 1.5 to 45 parts by mass of low-friction powder such as silicone resin powder or fluororesin powder per 100 parts by mass of the base resin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-12480 [Patent Document 2] JP 2016-51143 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, fluorine-based surface treatment agents and silicone-based surface treatment agents are known as surface treatment agents used to reduce the stickiness of elastomer articles or to lower the sliding properties (lower the coefficient of friction). However, fluorine-based surface treatment agents are being considered for inclusion in PFAS regulations, and given the recent trend toward low environmental impact, there are concerns that their use will be restricted in the future. Furthermore, silicone-based surface treatment agents have problems with contact failure, limiting their use in the electronic component field. Therefore, there is a demand for new types of surface treatment agents that can reduce the tackiness and friction coefficient of elastomer articles, have a low environmental impact, and are free from the problem of contact failure, as alternatives to fluorine-based surface treatment agents and silicone-based surface treatment agents.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an aqueous surface treatment agent and a method for producing the same that can reduce the stickiness and the coefficient of friction of an article without using a fluorine-based surface treatment agent or a silicone-based surface treatment agent, that has a low environmental impact, and that is free from the problem of contact failure; a method for treating the surface of an elastomer article using the aqueous surface treatment agent; and an elastomer article having a surface treatment layer formed by surface treatment using the aqueous surface treatment agent. [Means for solving the problem]

[0008] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that an aqueous surface treatment agent containing (A) component: polyurethane resin particles, (B) component: ultra-high molecular weight polyethylene particles having a mass average molecular weight of 1,000,000 or more, and (C) component: an acetylene-based surfactant can reduce the stickiness and reduce the coefficient of friction of an article, has a low environmental impact, and is free from the problem of contact failure, thereby completing the present invention.

[0009] Thus, according to the present invention, there are provided aqueous surface treatment agents [1] to [8], a method for producing an aqueous surface treatment agent [9], surface treatment methods

[10] to

[12] , and an elastomer article

[13] . [1] An aqueous surface treatment agent characterized by containing the following components (A), (B), and (C): (A) Component: Polyurethane resin particles (B) Component: Ultra-high molecular weight polyethylene particles with a mass average molecular weight of 1,000,000 or more (C) Component: Acetylenic surfactant [2] The aqueous surface treatment agent according to [1], which is a dispersion in an aqueous solvent containing the components (A), (B), and (C). [3] The aqueous surface treatment agent according to [1] or [2], wherein the component (A) contains at least first polyurethane resin particles having an elastic modulus (MPa) of 500 MPa or more and second polyurethane resin particles having an elastic modulus (MPa) of less than 100 MPa. [4] The aqueous surface treatment agent according to [1] or [2], wherein the ultra-high molecular weight polyethylene particles of the component (B) are fine particles having an average particle size of 1 to 100 μm.

[0010] [5] The aqueous surface treatment agent according to [1] or [2], wherein the content of the component (A) is 35.0 to 98.5 mass% based on the total amount of the components (A), (B), and (C). [6] The aqueous surface treatment agent according to [1] or [2], wherein the content of the component (B) is 1.0 to 64.5 mass% relative to the total amount of the components (A), (B), and (C). [7] The aqueous surface treatment agent according to [1] or [2], wherein the content of the component (C) relative to the total amount of the components (A), (B), and (C) is 0.5 to 64.0 mass%. [8] The aqueous surface treatment agent according to [1] or [2], which is a surface treatment agent for elastomers.

[0011] [9] A method for producing the aqueous surface treatment agent according to [1] above, comprising the following steps (I), (II), and (III): (1) Step (I): Adding the following component (C) to an aqueous solvent to prepare a uniform aqueous solvent solution: (2) Step (II): A step of adding the following component (A) to the aqueous solvent solution obtained in step (I) to obtain a uniform dispersion: (3) Step (III): A step of adding the following component (B) to the dispersion obtained in step (II) to obtain a uniform dispersion. (A) Component: Polyurethane resin particles (B) Component: Ultra-high molecular weight polyethylene particles with a mass average molecular weight of 1,000,000 or more (C) Component: Acetylenic surfactant

[10] A surface treatment method for an elastomer article, comprising applying the aqueous surface treatment agent according to [1] or [2] to the surface of an elastomer article, and then drying the resulting coating film.

[11] The surface treatment method according to

[10] , wherein the coating method is spray coating.

[12] The amount of water-based surface treatment agent applied is 80 g / m 2 ~2000g / m 2 The surface treatment method according to

[10] ,

[13] An elastomer article comprising a surface treatment layer provided on at least a portion thereof, the surface treatment layer being formed by a surface treatment using the aqueous surface treatment agent described in [1] or [2]. [Effects of the Invention]

[0012] According to the present invention, there are provided an aqueous surface treatment agent and a method for producing the same that can reduce the stickiness and the coefficient of friction of an article without using a fluorine-based surface treatment agent or a silicone-based surface treatment agent, that has a low environmental impact, and that is free from the problem of contact failure; a method for treating the surface of an elastomer article using the aqueous surface treatment agent; and an elastomer article having a surface treatment layer formed by surface treatment using the aqueous surface treatment agent. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below, divided into the following sections: 1) an aqueous surface treatment agent, 2) a method for producing an aqueous surface treatment agent, and 3) a method for treating the surface of an elastomer article.

[0014] 1) Water-based surface treatment agents A first aspect of the present invention is an aqueous surface treatment agent characterized by containing the following components (A), (B), and (C): (A) Component: Polyurethane resin particles (B) Component: Ultra-high molecular weight polyethylene particles with a mass average molecular weight of 1,000,000 or more (C) Component: Acetylenic surfactant

[0015] The aqueous surface treatment agent of the present invention is a composition containing the components (A), (B), and (C), and an aqueous solvent, and is preferably a dispersion of the components (A), (B), and (C) in an aqueous solvent. As used herein, the term "aqueous solvent" refers to water or a mixed solvent of water and a water-miscible organic solvent. The aqueous solvent used in the present invention is preferably water or a mixed solvent consisting of water and a water-miscible organic solvent, and the water content in the mixed solvent is preferably 50% by mass or more, and more preferably water. The water used is preferably one that does not contain impurities, such as distilled water or deionized water. The aqueous surface treatment agent of the present invention has the advantage of being environmentally friendly because it uses an aqueous solvent.

[0016] <Component (A): Polyurethane resin particles> The polyurethane resin used in the present invention is preferably in a particulate form from the viewpoint of dispersibility in an aqueous solvent.

[0017] The average particle size of the polyurethane resin particles is usually 1 to 1,000 nm, preferably 5 to 800 nm. If the average particle size is less than 1 nm, the polyurethane resin will be in an aqueous solution state, which will significantly reduce water resistance and may make it impossible to achieve high molecular weight at an appropriate viscosity. On the other hand, if the average particle size exceeds 1,000 nm, the dispersion may become unstable and sedimentation may occur. The "average particle size of the polyurethane resin particles" can be measured by dynamic light scattering (DLS).

[0018] The polyurethane resin can be produced using a polyol compound, a compound having an active hydrogen group and a hydrophilic group in the molecule, an organic polyisocyanate, and, if necessary, a chain extender and a polymerization terminator.

[0019] The polyol compound is not particularly limited as long as it contains two or more hydroxyl groups in the molecule. For example, polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, and glycerin; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol; polyester polyols obtained from dicarboxylic acids such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, phthalic acid, and isophthalic acid and glycols such as ethylene glycol, triethylene glycol, propylene glycol, butylene glycol, tripropylene glycol, and neopentyl glycol; polycaprolactone polyols; polybutadiene polyols; polycarbonate polyols; polythioether polyols; and the like can be used. The polyol compounds may be used alone or in combination of two or more.

[0020] The compound having an active hydrogen group and a hydrophilic group in the molecule can be a known compound containing an active hydrogen and an anionic group (an anionic group or an anion-forming group (a group that reacts with a base to form an anionic group, in this case, a group that forms an anionic group by neutralization with a base before, during, or after the urethanization reaction)). Examples include the compounds described in JP-B-42-24192 and JP-B-55-41607 (α,α-dimethylolpropionic acid, α,α-dimethylolbutyric acid, etc.); compounds having an active hydrogen and a cationic group in the molecule (compounds described in JP-B-43-9076, etc.); and compounds having an active hydrogen and a nonionic hydrophilic group in the molecule (compounds described in JP-B-41718, etc.).

[0021] The organic polyisocyanate is not particularly limited as long as it has two or more isocyanate groups in the molecule. For example, aliphatic diisocyanates such as 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexyl-2,4-diisocyanate, methylcyclohexyl-2,6-diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanato)methylcyclohexane, tetramethylxylylene diisocyanate, transcyclohexane-1,4-diisocyanate, and lysine diisocyanate are available. Examples of suitable polyisocyanates include aromatic diisocyanates such as 6-toluylene diisocyanate, diphenylmethane-4,4'-diisocyanate, 1,5'-naphthene diisocyanate, tolidine diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, and 1,3-phenylene diisocyanate; and triisocyanates such as lysine ester triisocyanate, triphenylmethane triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4,4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate. These polyisocyanate compounds may also be used as dimers or trimers (compounds having an isocyanurate bond), or may be reacted with an amine to form a biuret. Furthermore, polyisocyanates having urethane bonds obtained by reacting these polyisocyanate compounds with polyols can also be used.

[0022] The chain extender that may be added as needed during production of the polyurethane resin is not particularly limited as long as it contains two or more active hydrogen groups. Examples include low-molecular-weight polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, 3-methylpentanediol, 2-ethyl-1,3-hexanediol, and trimethylolpropane; polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, hydrazine, xylylenediamine, and isophoronediamine; and water.

[0023] In the reaction to obtain the polyurethane resin, a catalyst can be used as needed. Examples of the catalyst include salts and organometallic derivatives of metals with organic and inorganic acids such as dibutyltin laurate, dioctyltin laurate, stannous octoate, zinc octoate, and tetra-n-butyl titanate; organic amines such as triethylamine; and 1,8-diazabicyclo[5.4.0]-7-undecene.

[0024] Examples of the polymerization terminator include compounds having one active hydrogen in the molecule (such as monoalcohols and monoamines) and monoisocyanate compounds.

[0025] In addition, if an isocyanate group remains at the polymer terminal in the reaction for obtaining a polyurethane resin, it is also preferable to carry out a termination reaction of the isocyanate group. The termination reaction of the isocyanate group can be carried out using a compound reactive with the isocyanate group. Examples of such compounds that can be used include monofunctional compounds such as monoalcohols and monoamines; and compounds having two types of functional groups that have different reactivities with isocyanate.

[0026] The polyurethane resin may be produced without using a solvent or with an organic solvent, which may be inactive to isocyanate groups or less active than the reactants to isocyanate groups.

[0027] Examples of the organic solvent to be used include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, Swazol (trade name, manufactured by Cosmo Oil Co., Ltd.), and Solvesso (trade name, manufactured by Exxon Chemical Co., Ltd.); aliphatic hydrocarbon solvents such as n-hexane; alcohol-based solvents such as methanol, ethanol, and isopropyl alcohol; ether-based solvents such as dioxane and tetrahydrofuran; ester-based solvents such as ethyl acetate, butyl acetate, and isobutyl acetate; glycol ether ester-based solvents such as ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, and ethyl-3-ethoxypropionate; amide-based solvents such as dimethylformamide and dimethylacetamide; and lactam-based solvents such as N-methyl-2-pyrrolidone.

[0028] The reaction method for obtaining the polyurethane resin may be either a one-shot method in which each component is reacted at once, or a multi-step method in which the components are reacted in stages (a method in which a part of the active hydrogen-containing compound (e.g., a polymer polyol) is reacted to form an NCO-terminated prepolymer, and then the remainder of the active hydrogen-containing compound is reacted to produce the prepolymer). The synthetic reaction of the polyurethane resin is usually carried out at 40 to 140°C, preferably 60 to 120°C.

[0029] The copolymerization form of the polyurethane resin is not particularly limited, and may be any of a random copolymer, a block copolymer, and a graft copolymer.

[0030] By appropriately selecting the types and combinations of polyols, polyisocyanates, polyamines, and chain extenders used, a wide range of resin designs are possible. That is, polyurethane resins with various properties such as toughness (high hardness), weather resistance, abrasion resistance, chemical resistance, quick drying, adhesion, and flexibility can be obtained depending on the application of the aqueous surface treatment agent.

[0031] Furthermore, as will be described later, by appropriately selecting the types of polyol, polyisocyanate, polyamine, and chain extender to be used, and the combination thereof, it is possible to obtain a polyurethane resin having a desired elastic modulus.

[0032] The elastic modulus (MPa) of the polyurethane resin used in the present invention is preferably 500 MPa or more, more preferably 530 MPa or more, and particularly preferably 550 MPa or more, and is preferably 100 MPa or less, more preferably 80 MPa or less, and particularly preferably 60 MPa or less. The elastic modulus (MPa) of the polyurethane resin can be measured using a precision universal testing machine in accordance with JIS K7161:2014.

[0033] In general, polyurethane resins with a high elastic modulus tend to impart toughness (high hardness) to the coating film of a surface treatment agent, while polyurethane resins with a low elastic modulus tend to impart flexibility, conformability, and adhesion to the coating film of a surface treatment agent.

[0034] To obtain a polyurethane resin with a relatively high modulus of elasticity, for example, the amount of aromatic groups present in the repeating units (the amount of hard segments present) can be increased, while to obtain a polyurethane resin with a relatively low modulus of elasticity, for example, the amount of long-chain alkylene groups present in the repeating units (the amount of soft segments present) can be increased.

[0035] In the surface treatment agent of the present invention, the component (A): polyurethane resin particles preferably contains at least polyurethane resin particles (first polyurethane resin particles) having an elastic modulus of 500 MPa or more and polyurethane resin particles (second polyurethane resin particles) having an elastic modulus of less than 100 MPa.

[0036] That is, from the viewpoint of easily obtaining an aqueous surface treatment agent having excellent toughness (high hardness), flexibility, conformability, and adhesion, it is preferable to use a combination of first polyurethane resin particles having a relatively high elastic modulus and second polyurethane resin particles having a relatively low elastic modulus as the component (A): polyurethane resin particles used in the present invention.

[0037] When the first polyurethane resin particles and the second polyurethane resin particles are used in combination, the ratio of the first polyurethane resin particles to the second polyurethane resin particles is not particularly limited, but the mass ratio of (first polyurethane resin particles):(second polyurethane resin particles) is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, and even more preferably 1:3 to 3:1. By containing the first polyurethane resin particles and the second polyurethane resin particles in such a ratio, it is possible to easily obtain an aqueous surface treatment agent that has excellent toughness (high hardness), flexibility, conformability, and adhesion.

[0038] Furthermore, it is preferable to use the polyurethane resin particles (component (A)) used in the present invention as a dispersion in an aqueous solvent in order to obtain the aqueous surface treatment agent of the present invention more efficiently.

[0039] A dispersion of polyurethane resin particles in an aqueous solvent (hereinafter, this may be referred to as a "polyurethane dispersion") can be produced by adding water and a neutralizing agent to a polyurethane prepolymer and emulsifying the mixture. Specifically, the polyurethane dispersion can be obtained by heating a reaction solution containing a polyurethane prepolymer in which the urethanization reaction has been completed to about 50°C or less, adding a mixture of water and a neutralizing agent while stirring the entire mixture, and stirring until the mixture is uniform. In this case, the neutralizing agent may be added first to the reaction solution containing the polyurethane prepolymer, and water may be added after the mixture has become uniform.

[0040] As the neutralizing agent, organic amines, alkali metals, and inorganic alkalis can be used.

[0041] The polyurethane dispersion is a pale blue to pale white dispersion that is stable over time. The content of polyurethane resin particles in the dispersion is 5 to 60% by mass, preferably 20 to 55% by mass.

[0042] The content of the (A) component (when two or more types of (A) components are used, the total amount thereof) in the aqueous surface treatment agent of the present invention is preferably 35.0 to 98.5 mass %, more preferably 50.0 to 90.0 mass %, and even more preferably 60.0 to 80.0 mass %, relative to the total amount of the (A), (B), and (C) components. By including component (A) in such a ratio, it is possible to reduce the tackiness of the article and the coefficient of friction, and it becomes easier to obtain an aqueous surface treatment agent that is environmentally friendly and does not cause contact failure problems.

[0043] <Component (B): Ultra-high molecular weight polyethylene particles> The component (B): ultra-high molecular weight polyethylene particles used in the present invention has a mass average molecular weight of 1×10 6 These polyethylene particles have a spherical shape. When the ultra-high molecular weight polyethylene particles form a dry lubricating coating, the dry lubricating coating has low roughness, and a low coefficient of friction can be achieved by the sliding of a mating component on the ultra-high molecular weight polyethylene particles located near the surface. Furthermore, lubricating coatings containing ultra-high molecular weight polyethylene particles have excellent wear resistance.

[0044] The mass average molecular weight (Mw) of the ultra-high molecular weight polyethylene particles is 1 × 10 6 There is no particular limitation as long as it is equal to or greater than 1.2 × 10 6 More preferably, it is 1.5×10 or more. 6 More preferably, it is equal to or greater than this. The mass average molecular weight (Mw) of the ultra-high molecular weight polyethylene particles can be measured, for example, by gel permeation chromatography (GPC) and calculated as a value converted into standard polystyrene.

[0045] The average particle size of the ultra-high molecular weight polyethylene particles is preferably 1 to 100 μm, more preferably 2 μm or more, even more preferably 5 μm or more, and particularly preferably 7 μm or more. By having an average particle size of 1 μm or more, the amount of ultra-high molecular weight polyethylene particles present near the surface of the dry lubricating coating can be controlled to an appropriate level, allowing the mating member to slide over the surface and achieving a low coefficient of friction. Furthermore, the average particle size is preferably 100 μm or less, more preferably 30 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less. By having an average particle size of 100 μm or less, it is possible to prevent the surface roughness of the dry lubricating coating from increasing. The average particle size of the ultra-high molecular weight polyethylene particles can be measured using a laser diffraction particle size analyzer. Component (B) can be used alone or in combination with two or more species differing in mass average molecular weight (Mw) or average particle size.

[0046] Component (B): ultra-high molecular weight polyethylene particles may be synthesized by a conventional method or may be commercially available, such as the Sunfine (trade name, manufactured by Asahi Kasei Chemicals Corporation) series, the Mipelon (trade name, manufactured by Mitsui Chemicals, Inc.) series, the Hi-Zex Million (trade name, manufactured by Mitsui Chemicals, Inc.) series, Dyneema (trade name, manufactured by DSM), Spectra (trade name, manufactured by Honeywell), and GUR (trade name, manufactured by Celanese).

[0047] The content of the ultra-high molecular weight polyethylene particles (B) component in the aqueous surface treatment agent of the present invention is preferably 1.0 to 64.5 mass%, more preferably 3.0 to 30%, and even more preferably 5 to 25 mass%, based on the total amount of the (A), (B), and (C) components. By including component (B) in such a ratio, it is possible to reduce the adhesion of the article and the friction coefficient, and it becomes easier to obtain an aqueous surface treatment agent that is environmentally friendly and does not cause contact failure problems.

[0048] <Component (C): Acetylenic surfactant> The aqueous surface treatment agent of the present invention preferably contains one or more acetylene-based surfactants. By including an acetylene-based surfactant, it is possible to easily obtain a dispersion in which components (A) and (B) are uniformly dispersed in the aqueous dispersion. If component (C) is not added, it may be difficult to uniformly disperse component (B) in an aqueous solvent due to the water-repellent properties of component (B).Furthermore, the resulting surface treatment agent itself has low wettability, which may make it difficult to uniformly apply the surface treatment agent to the surface of an article.

[0049] Acetylenic surfactants are nonionic compounds that have at least one triple bond between carbon atoms in the molecule.

[0050] The number of carbon atoms in the molecule of the acetylene surfactant is preferably 11 to 100, more preferably 12 to 70, even more preferably 13 to 50, and most preferably 14 to 40. When the number of carbon atoms is within these suitable ranges, the wettability is further improved. The acetylene surfactant preferably has a hydroxyl group or an oxygen atom forming an ether bond in the molecule, which further improves wettability.

[0051] Specific examples of the acetylene surfactant include acetylene glycols and derivatives thereof represented by the following formulas (α) and (β):

[0052] [ka]

[0053] [ka]

[0054] In formulas (α) and (β), R 1 ~R 8are each independently an alkyl group having 1 to 10 carbon atoms, and n and m are each independently an integer of 1 or more, where n+m=1 to 40. The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.

[0055] Specific examples of the acetylene glycol and its derivatives represented by the above formulas (α) and (β) include 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, 5,8-dimethyl-6-dodecyne-5,8-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 4,7-dimethyl-5-decyne-4,7-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2,5-dimethyl-3-hexyne-2,5-diol, an ethoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol (ethylene oxide addition mole number: 1.3), an ethoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol ( ethoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol (number of moles of ethylene oxide added: 10), ethoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol (number of moles of ethylene oxide added: 30), ethoxylated 3,6-dimethyl-4-octyne-3,6-diol (number of moles of ethylene oxide added: 20), and the like. These may be used alone or in combination of two or more.

[0056] In the present invention, commercially available products may be used as the acetylene surfactant of component (C). Examples of commercially available products include Olfine D-10, Olfine D-10A, Olfine D-10E, Olfine D-10H, Olfine D-10PG, Olfine E1004C, Olfine E1004, Olfine E1006, Olfine E1010, Olfine E1020, Olfine E1030W, Olfine E1204C, Olfine EXP.4001, Olfine EXP.4200, Olfine EXP.4123, Olfine EXP.4300, Olfine WE-002, and Olfine Olfine WE-003, Olfine PD-001, Olfine PD-002W, Olfine PD-005, Olfine PD-003, Olfine PD-201, Olfine PD-301A, Olfine PD-611, Olfine PD-631, Olfine SPC, Olfine AF-300, Olfine AF-400, Olfine SK-14, Olfine AK-02, Surfynol 420, Surfynol 440, Surfynol 104E (all of which are trade names manufactured by Nissin Chemical Industry Co., Ltd.).

[0057] The content of component (C) in the aqueous surface treatment agent of the present invention is preferably 0.5 to 64.0 mass%, more preferably 1.0 to 30.0 mass%, and even more preferably 1.5 to 25.0 mass%, relative to the total amount of components (A), (B), and (C). When the content is within the above range, it is possible to more easily obtain a dispersion in which the components (A) and (B) are uniformly dispersed.

[0058] The aqueous surface treatment agent of the present invention is useful as a surface treatment agent for elastomers. Examples of elastomers include rubber materials such as natural rubber (NR), fluororubber (FKM, FEPM), acrylonitrile butadiene rubber (NBR), hydrogenated acrylonitrile butadiene rubber (hydrogenated NBR), styrene butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), butyl rubber (IIR), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), ethylene propylene rubber (EPM, EPDM), urethane rubber (AU, EU), and silicone rubber (VMQ, FVMQ); thermoplastic resins such as ABS resin (acrylonitrile-butadiene-styrene copolymer resin) and AS resin (acrylonitrile-styrene copolymer resin), and resin materials such as thermosetting resins. The aqueous surface treatment agent of the present invention is preferably intended to impart non-stick properties and improve slip properties to rubber materials.

[0059] The aqueous surface treatment agent according to the embodiment of the present invention can reduce the tackiness of elastomers and lower the coefficient of friction, has a low environmental impact, and is free from the problem of contact failure.

[0060] 2) Manufacturing method of surface treatment agent A second aspect of the present invention is a method for producing the aqueous surface treatment agent of the present invention, which comprises the following steps (I), (II), and (III): (1) Step (I): Adding the following component (C) to an aqueous solvent to prepare a uniform aqueous solution: (2) Step (II): A step of adding the following component (A) to the aqueous solvent solution obtained in step (I) to obtain a uniform dispersion: (3) Step (III): A step of adding the following component (B) to the solution obtained in step (II) to obtain a uniform dispersion. (A) Component: Polyurethane resin particles (B) Component: Ultra-high molecular weight polyethylene particles with a mass average molecular weight of 1,000,000 or more (C) Component: Acetylenic surfactant

[0061] (1) Process (I) First, a predetermined amount of the component (C) is added to an aqueous solvent, and the entire mixture is stirred to obtain a uniform aqueous solvent solution. In the production method of the present invention, it is essential to first provide a step (I) of obtaining a solution of component (C) in an aqueous solvent, which makes it possible to easily obtain a dispersion in which components (A) and (B) are uniformly dispersed in an aqueous solvent.

[0062] (2) Process (II) Next, a predetermined amount of the component (A) is added to the aqueous solvent solution obtained in step (I), and the entire volume is stirred until it becomes homogeneous, thereby obtaining a dispersion in which the polyurethane resin particles are uniformly dispersed in the aqueous solvent. The component (A) used here is preferably a polyurethane resin dispersion. By using a polyurethane resin dispersion, the desired aqueous surface treatment agent can be produced more efficiently. Furthermore, when two or more polyurethane resin dispersions are used, the order of addition is not particularly limited.

[0063] (3) Process (III) Thereafter, a predetermined amount of the component (B) is added to the dispersion obtained in step (II) and stirred until the entire volume becomes uniform, thereby obtaining the intended aqueous surface treatment agent of the present invention.

[0064] In the production method of the present invention, the order of steps (II) and (III) may be step (III) followed by step (II) unless there is a particular problem.

[0065] According to the method for producing an aqueous surface treatment agent according to an embodiment of the present invention, the aqueous surface treatment agent of the present invention can be produced simply and efficiently.

[0066] 3) Surface treatment method for elastomer articles A third aspect of the present invention is a method for treating the surface of an elastomer article, which comprises applying the aqueous surface treatment agent of the present invention to the surface of an elastomer article and then drying the resulting coating film of the aqueous surface treatment agent.

[0067] The elastomer article to be treated by the surface treatment method of the present invention is not particularly limited in type, shape, etc., as long as the surface to be treated by the aqueous surface treatment agent of the present invention is composed of an elastomer. Examples of elastomers include those listed as targets for treatment by the aqueous surface treatment agent of the present invention, and rubber materials are preferred.

[0068] The surface treatment of the elastomeric article is carried out as follows. First, the aqueous surface treatment agent of the present invention is applied to at least a part of the surface of an elastomer article (a member to be treated) by a known coating method to form a coating film of the aqueous surface treatment agent. Examples of the coating method include immersion, brush coating, roll coating, spray coating, knife coating, and dip coating. Among these, spray coating is preferred from the viewpoint of simplicity and convenience. The spray coating method allows the aqueous surface treatment agent of the present invention to be uniformly applied even to articles having complex shapes.

[0069] Next, the resulting coating film is dried by heating at about 120 to 150° C. for about 10 to 60 minutes to form a coating (surface treatment layer) of the aqueous surface treatment agent.

[0070] The amount of the aqueous surface treatment agent applied is preferably 80 g / m 2 More preferably, 80 g / m 2 ~2000g / m 2 , and more preferably 300 g / m 2 ~1000g / m 2 is. Such an amount of coating can provide a sufficient surface treatment effect.

[0071] In this manner, an elastomer article can be obtained which has, at least in part, a surface-treated layer formed by surface treatment using the aqueous surface treatment agent of the present invention.

[0072] According to the surface treatment method of the embodiment of the present invention, by using the aqueous surface treatment agent of the present invention, it is possible to achieve reduced adhesion and a low friction coefficient of elastomer articles that are equivalent to or better than those of conventionally known fluorine-based surface treatment agents or silicone-based surface treatment agents, and it is possible to obtain the effects of reducing the burden on the environment and not causing contact failure when used in electronic components.

[0073] Furthermore, the elastomer article according to the embodiment of the present invention has, at least in part, a surface treatment layer formed by surface treatment using the aqueous surface treatment agent of the present invention. The surface treatment layer has excellent adhesion and shape conformability, and imparts excellent non-stickiness and low sliding properties to the elastomer article.

[0074] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Example]

[0075] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Note that all "parts" are by weight.

[0076] <Materials used> The following components were used as components (A), (B), (C), and (c). [Component (A): Polyurethane resin particles] (A1): Aqueous dispersion of polyurethane resin particles (product name: UW-2001A, manufactured by UBE Corporation; elastic modulus (MPa): 10 MPa; content of polyurethane resin particles: 26 to 33% by mass) (A2): Aqueous dispersion of polyurethane resin particles (product name: UW-5034-E, manufactured by UBE Corporation; elastic modulus (MPa): 1100 MPa; content of polyurethane resin particles: 26 to 35% by mass) [Component (B): Ultra-high molecular weight polyethylene particles with a mass of 1,000,000 or more] (B1): Mipelon PM-200 (ultra-high molecular weight polyethylene powder, manufactured by Mitsui Chemicals, Inc., mass average molecular weight: 1.8 million, average particle size: 10 μm) (B2): Miperon XM-220 (ultra high molecular weight polyethylene powder, manufactured by Mitsui Chemicals, mass average molecular weight: 2 million, average particle size: 30 μm) [Component (C): Acetylenic surfactant] (C1): Acetylenic surfactant (trade name: Olfine EXP. 4200, manufactured by Nissin Chemical Industry Co., Ltd.) (C2): Acetylenic surfactant (trade name: Olfine EXP. 4300, manufactured by Nissin Chemical Industry Co., Ltd.) [Component (c): Other surfactants] (c1): Hexadecyltrimethylammonium bromide (c2): Trimethylstearylammonium chloride

[0077] <Production of water-based surface treatment agents> (1) Example 1 50 parts of (C1) were added to 1500 parts of distilled water, and the whole was stirred to obtain a uniform aqueous solution. Next, 125 parts of (A1) and 250 parts of (A2) were added to this aqueous solution, and the whole was stirred to obtain a uniform dispersion. Furthermore, 50 parts of (B1) were added to the obtained dispersion, and the whole was stirred to obtain a uniform aqueous dispersion of an aqueous surface treatment agent.

[0078] (2) Examples 2 to 48 and Comparative Examples 1 to 4 Surface treatment agents for Examples 2 to 48 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that (A1), (A2), (B1), (C1), (C2), (c1), and (c2) were used in the amounts shown in Tables 1, 2, and 3. In Table 3, Comparative Example 1 is an aqueous surface treatment agent that does not contain a surfactant, Comparative Example 2 is an aqueous surface treatment agent that does not contain component B, and Comparative Examples 3 and 4 are aqueous surface treatment agents in which other surfactants [(c1) and (c2)] were added instead of component (C). In Comparative Examples 3 and 4, the active ingredient concentration of the acetylene surfactant used as component (C) was 80 mass %, so the amount of the other surfactant added was 40 parts.

[0079] [Table 1]

[0080] [Table 2]

[0081] [Table 3]

[0082] <Performance evaluation test> The aqueous surface treatment agents obtained in Examples 1 to 48 and Comparative Examples 1 to 4 were subjected to the following performance evaluation tests. (1) Preparation of test samples The test samples were prepared as square rubber sheets 1 to 4, each measuring 2 cm on each side. Each rubber sheet was coated with 400 g / m of the aqueous surface treatment agent produced in the examples and comparative examples (Examples 1 to 48 and Comparative Examples 1 to 4). 2 The rubber sheet with the surface treatment layer formed thereon was then heated at 150°C for 10 minutes to produce the rubber sheet.

[0083] In addition, since the formulations of Comparative Examples 1, 3, and 4 did not contain component C2, it was not possible to obtain a uniform solution and to uniformly coat various rubber sheets, and therefore abrasion friction tests were not conducted.

[0084] Rubber sheets 1 to 4 have the following meanings (the same applies below). Rubber sheet 1: Fluorine rubber sheet Rubber sheet 2: Ethylene propylene rubber sheet Rubber sheet 3: Nitrile rubber sheet Rubber sheet 4: Silicone rubber sheet

[0085] (2) Friction and wear test The prepared test samples were subjected to a friction and wear test under the following conditions using a ball-on-disk friction and wear tester (compliant with JIS R 1613-1993) to measure the friction coefficient and calculate the average value of the friction coefficient. Furthermore, to evaluate the wear resistance of the surface treatment layer, the sample surfaces after the test were visually observed to check for the presence or absence of wear marks. Samples for which no wear marks were observed on the surface after the test were rated "Good," and samples for which wear marks were observed were rated "Poor."

[0086] (Friction and wear test conditions) The friction coefficient was measured once per second with a ball radius of 3.0 mm, a rotation speed of 15 rpm, a sample peripheral speed of 4.7 mm / sec, a pressing load of 0.49 N, and a measurement time of 3600 seconds. A graph was obtained with the friction coefficient on the vertical axis and time (unit: seconds) on the horizontal axis, and the average friction coefficient was calculated from the obtained graph. The load, radius, rotation speed, linear speed, measurement time, and related standards (JIS) used during measurement are as follows: Load: 50g Radius: 3mm Rotation speed: 15 rpm Linear speed: 4.712mm / sec Measurement time: 3600sec Related standard: JIS R 1613-1993

[0087] The test results are shown in Tables 4 and 5. In Table 5, Reference Example 2 shows the measurement results when an existing low-sliding silicone-based surface treatment agent (manufactured by Fujikura Composites Co., Ltd.) was used.

[0088] [Table 4]

[0089] [Table 5]

[0090] Tables 4 and 5 show that the aqueous surface treatment agents of Examples 1 to 48 have the effect of imparting excellent low sliding properties (low coefficient of friction) and high adhesion to various rubber sheets, equivalent to those of the conventional silicone-based surface treatment agent (surface treatment agent of Reference Example 2).

[0091] (3) TAC test The prepared samples were subjected to a test using a probe tack tester (product name: tacking tester TAC-II, manufactured by Rhesca Co., Ltd.) under the following conditions to measure adhesive strength.

[0092] (TAC test conditions) A probe (a cylindrical probe made of stainless steel (diameter: 5.1 mm)) was brought into contact with the test piece for 3 seconds while applying a load of 100 gf, and then the probe was peeled off in a direction perpendicular to the surface of the test piece at a speed of 600 mm / min, and the force required to peel off (adhesive strength (gf)) was measured. The test results are shown in Table 6. Reference Example 1 shows the measurement results when an existing non-stick fluorine-based surface treatment agent (manufactured by Fujikura Composites Co., Ltd.) was used, and Reference Example 2 shows the measurement results when an existing low-sliding silicone-based surface treatment agent (manufactured by Fujikura Composites Co., Ltd.) was used.

[0093] [Table 6]

[0094] The surface treatment of rubber sheets 1 to 4 was carried out using the aqueous surface treatment agent of Example 40. As a result, it was found that the use of the aqueous surface treatment agent of Example 40 can achieve an effect of reducing adhesion (low TAC value) almost equivalent to that of the conventional fluorine-based surface treatment agent (Reference Example 1) and the silicone-based surface treatment agent (Reference Example 2).

[0095] (4) Tracking stress test The prepared sample was clamped at both ends with a jig. The screw inside the jig was then turned to widen the gap between the two clamped ends to the left and right. The sample surface was then observed under an electron microscope at 0%, 25%, and 50% elongation to evaluate conformability. Samples that showed no cracks in the surface treatment layer by 50% elongation were evaluated as "Good," samples that showed cracks in the surface treatment layer by 50% elongation were evaluated as "Good," samples that showed cracks in the surface treatment layer by 25% elongation were evaluated as "Poor," and samples that showed cracks in the surface treatment layer by 25% elongation were evaluated as "Poor." The results are shown in Table 7.

[0096] [Table 7]

[0097] From Table 7, we can see the following: The aqueous surface treatment agents of Examples 1, 12, 25, 26, 28, 31 and 40 showed excellent conformability to the rubber sheets 1 to 4. The aqueous surface treatment agents of Examples 29 and 30 also showed excellent conformability to the rubber sheets 1, 3 and 4.

[0098] As described above, the aqueous surface treatment agent of the present invention can reduce the tackiness of an article and achieve a low coefficient of friction without using a fluorine-based surface treatment agent or a silicone-based surface treatment agent. The aqueous surface treatment agent of the present invention has excellent adhesion and conformability, is environmentally friendly, and is free from the problem of contact failure.

Claims

1. An aqueous surface treatment agent characterized by containing the following components (A), (B), and (C): Component (A): Polyurethane resin particles Component (B): Ultra-high molecular weight polyethylene particles having a mass average molecular weight of 1,000,000 or more Component (C): Acetylenic surfactant

2. 2. The aqueous surface treatment agent according to claim 1, which is a dispersion in an aqueous solvent containing the components (A), (B), and (C).

3. 3. The aqueous surface treatment agent according to claim 1, wherein the component (A) comprises at least first polyurethane resin particles having an elastic modulus (MPa) of 500 MPa or more and second polyurethane resin particles having an elastic modulus (MPa) of less than 100 MPa.

4. 3. The aqueous surface treatment agent according to claim 1, wherein the ultra-high molecular weight polyethylene particles of component (B) are fine particles having an average particle size of 1 to 100 μm.

5. 3. The aqueous surface treatment agent according to claim 1, wherein a content of the component (A) relative to the total amount of the components (A), (B), and (C) is 35.0 to 98.5 mass%.

6. 3. The aqueous surface treatment agent according to claim 1, wherein a content of the component (B) relative to the total amount of the components (A), (B), and (C) is 1.0 to 64.5 mass%.

7. 3. The aqueous surface treatment agent according to claim 1, wherein a content of the component (C) relative to the total amount of the components (A), (B), and (C) is 0.5 to 64.0 mass%.

8. The aqueous surface treatment agent according to claim 1 or 2, which is a surface treatment agent for an elastomer.

9. 2. A method for producing the aqueous surface treatment agent according to claim 1, comprising the following steps (I), (II), and (III): (1) Step (I): A step of adding the following component (C) to an aqueous solvent to prepare a uniform aqueous solvent solution: (2) Step (II): A step of adding the following component (A) to the aqueous solvent solution obtained in step (I) to obtain a uniform dispersion: (3) Step (III): A step of adding the following component (B) to the dispersion obtained in step (II) to obtain a uniform dispersion. Component (A): Polyurethane resin particles Component (B): Ultra-high molecular weight polyethylene particles having a mass average molecular weight of 1,000,000 or more Component (C): Acetylenic surfactant

10. 3. A method for treating the surface of an elastomer article, comprising applying the aqueous surface treatment agent according to claim 1 or 2 to the surface of the elastomer article, and then drying the resulting coating film.

11. The surface treatment method according to claim 10, wherein the coating method is spray coating.

12. The amount of water-based surface treatment agent applied is 80 g / m ２ ~2000g / m ２ The surface treatment method according to claim 10, wherein

13. 3. An elastomer article comprising a surface treatment layer provided on at least a portion thereof, the surface treatment layer being formed by surface treatment using the aqueous surface treatment agent according to claim 1 or 2.

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