Olefin-based resin porous body, and polishing material or cleaning material comprising the olefin-based resin porous body.

Abstract

To provide a novel porous material that achieves both chemical resistance and processability. [Solution] This technology provides an olefin-based resin porous body that has been treated with fluorine gas. In the olefin-based resin porous body according to this technology, only the hydrogen on the surface may be replaced with fluorine. In the olefin-based resin porous body according to this technology, the surface may have IR peaks originating from CH bonds and CF bonds. In the olefin-based resin porous body according to this technology, open pores may be present. In the olefin-based resin porous body according to this technology can be manufactured by extracting and removing pore-forming material from a raw material composition. In the porous body according to this technology, it can be used as an abrasive material or a cleaning material.

Description

Technical Field

[0001] The present technology relates to an olefin resin porous body, and a polishing material or a cleaning material including the olefin resin porous body.

Background Art

[0002] Porous bodies made of resin are used in various fields. For example, functional separation membranes such as filters and filtration membranes, water retention materials, water stop materials, sustained release materials, stamp pads using solvent-type inks, members that absorb and hold organic solvents, bleeding pad materials, cosmetic tools, medical tools, polishing materials, or cleaning materials, etc., use porous bodies made of resin.

[0003] Techniques for imparting additional properties to porous bodies are also being developed according to the uses of the porous bodies. For example, in Patent Document 1, a kneaded product composed of a thermoplastic fluorocarbon resin, a pore-forming material composed of a water-soluble inorganic salt, and a lubricant composed of a water-soluble polymer inert to the thermoplastic fluorocarbon resin is used. By extracting and removing the pore-forming material and the lubricant with water to form a continuous pore structure, a porous body having good flame retardancy and chemical resistance, no quality deterioration such as discoloration during production, and no need for sintering in a subsequent process during production is proposed. [[ID=1十七]]

[0004] As one of the uses of porous bodies, for example, a polishing material can be mentioned. For example, Patent Document 2 discloses a polishing liquid for metal that can polish a substrate having a cobalt-containing film on its surface while suppressing corrosion, and a polishing method using the polishing liquid for metal. As a polishing cloth used during polishing, a porous fluororesin, etc. are disclosed.

[0005] Further, Patent Document 3 discloses a technique of using an applicator article formed of an open-cell foam material having a porosity of about 60% or more as a hydrophobic applicator used in a polishing system, and also describes performing a hydrophobic coating on this open-cell foam material with a hydrophobizing chemical solution.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-65124 [Patent Document 2] Japanese Patent Publication No. 2018-2797 [Patent Document 3] Special Publication No. 2023-517313 [Overview of the project] [Problems that the invention aims to solve]

[0007] As mentioned above, technologies for imparting new properties to porous materials are being developed, and technologies for improving chemical resistance by using fluorine-based resins have been proposed. However, due to the material properties, there are disadvantages such as difficulty in processing and hardening.

[0008] Therefore, the main objective of this technology is to provide a novel porous material that can achieve both chemical resistance and processability. [Means for solving the problem]

[0009] This technology provides a porous olefin resin body that has been treated with fluorine gas. In the olefin-based resin porous material relating to this technology, only the hydrogen on the surface may be replaced with fluorine. The olefin-based resin porous material relating to this technology may have IR peaks on its surface originating from CH bonds and CF bonds. In this technology, "the surface of a porous material" refers to the entire surface that can come into contact with the outside air, including the surface within the pores. For example, it is synonymous with the surface when measuring the specific surface area of ​​a porous material. The porous olefin resin material relating to this technology may have open cells. The porous olefin resin material related to this technology can be manufactured by extracting and removing the pore-forming material from the raw material composition. The porous material relating to this technology can be used as an abrasive material or a cleaning material. [Modes for carrying out the invention]

[0010] The following describes a preferred form for implementing this technology. The embodiments described below are examples of typical embodiments of this technology, and any combination of these embodiments is possible. Furthermore, this does not mean that the scope of this technology will be narrowed.

[0011] 1. Porous material The porous material related to this technology is an olefin-based resin porous material that has been treated with fluorine gas. Fluorine gas treatment is a process in which fluorine gas is brought into contact with the olefin-based resin porous material and a gas phase treatment is performed, chemically altering the portion of the olefin-based resin porous material that comes into contact with the fluorine gas. In other words, it is different from the technology of applying a layered coating to the surface, which is commonly referred to as fluorine coating. Specifically, hydrogen in the portion of the olefin-based resin porous material that comes into contact with the fluorine gas is replaced with fluorine. That is, IR peaks originating from CF bonds can be observed on the surface of the olefin-based resin porous material. Note that since the porous material related to this technology is an olefin-based resin porous material and is different from a fluororesin porous material, in addition to IR peaks originating from CF bonds, IR peaks originating from CH bonds can also be observed on its surface.

[0012] It is preferable to apply fluorine gas treatment only to the surface of the olefin-based resin porous body. That is, it is preferable that in the olefin-based resin porous body according to this technology, only the hydrogen on the surface is replaced with fluorine. That is, it is preferable that the olefin-based resin porous body has an IR peak originating from CF bonds only on its surface. Because the hydrogen inside is not replaced with fluorine, that is, because there is no IR peak originating from CF bonds inside the resin skeleton, the olefin-based resin skeleton remains inside the resin skeleton, and the chemical resistance can be improved while maintaining the excellent physical properties of the olefin-based resin porous body.

[0013] The method of fluorine gas treatment is not particularly limited as long as it does not impair the function or effect of this technology, and any method that allows the olefin-based resin porous body to come into contact with fluorine gas can be used. For example, one method involves placing the olefin-based resin porous body inside a space such as a kiln or container, filling the space with fluorine gas, and exposing it to the gas for a predetermined time. Fluorine gas treatment can also be performed with heating as needed.

[0014] The porous olefin resin material according to this technology preferably has open cells. Having open cells improves the solvent impregnation performance. For example, when the porous olefin resin material is used as an abrasive or cleaning material, the cleaning solvent can penetrate sufficiently into the interior of the porous material, improving the cleaning effect.

[0015] Olefin-based porous resins having open-cell structures can be manufactured using general porous material manufacturing methods, but for example, they can be manufactured by extracting and removing pore-forming materials from the raw material composition. In addition to olefin-based resins and pore-forming materials, water-soluble polymers that act as lubricants and other components can be used in the manufacture of olefin-based porous resins according to this technology. The components used in the manufacture of olefin-based porous resins according to this technology will be described in detail below.

[0016] (1) Olefin resins The porous material relating to this technology is characterized by containing an olefin-based resin as a resin component. A polyolefin resin is a resin whose main component is olefin component units. A resin whose main component is olefin component units means a resin that contains 50% by mass or more of olefin component units.

[0017] Examples of polyolefin resins that can be used in the present technology include polyethylene, polypropylene, polybutene, polypentene, and copolymers of olefin monomers and monomers copolymerizable with the olefin monomers. These can be used alone or in combinations of two or more.

[0018] Examples of polyethylene include ethylene homopolymers such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very-low-density polyethylene (VLDPE); ethylene-propylene random copolymers, ethylene-propylene block copolymers, ethylene-butene block copolymers, ethylene-butene random copolymers, ethylene-vinyl acetate copolymers, and ethylene-methyl methacrylate copolymers.

[0019] Examples of polypropylene resins include propylene homopolymers such as isotactic polypropylene, syndiotactic polypropylene, and atactic polypropylene; propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-butene random copolymers, propylene-butene block copolymers, propylene-ethylene-butene terpolymers, propylene-acrylic acid copolymers, and propylene-maleic anhydride copolymers.

[0020] In the present technology, among these, any one or more selected from the group consisting of α-olefin copolymers, polyethylene, and ethylene-octene copolymers are preferred.

[0021] (2) Pore-forming material As the pore-forming material that can be used in the present technology, it is preferably a substance that is soluble in water, alcohol, or an aqueous alcohol solution (preferably water), and is also stable when the resin melts. Specifically, for example, inorganic substances such as NaCl, KCl, CaC1, NH4Cl, NaNO3, and NaNO2; organic substances such as sodium salts of TME (trimethylolethane), trimethylolpropane, trimethylolbutane, sucrose, soluble starch, sorbitol, glycine, and various organic acids (for example, malic acid, citric acid, glutamic acid, succinic acid, succinic acid, etc.), and these can be used alone or in combination of two or more.

[0022] In the present technology, among these, it is particularly preferable to use inorganic substances, and among inorganic substances, it is particularly preferable to use NaCl.

[0023] The average particle size of the pore-forming material can be freely set as long as the functions and effects of the present technology are not impaired. The lower limit value of the average particle size of the pore-forming material is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more. By setting the lower limit value of the average particle size of the pore-forming material within this range, the size of the pores of the porous body can be controlled to a certain extent or more, and a porous body having a smooth surface can be provided.

[0024] The upper limit value of the average particle size of the pore-forming material is, for example, 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. By setting the upper limit value of the average particle size of the pore-forming material within this range, the size of the pores of the porous body can be controlled to a certain extent or less, and a stable porous body can be obtained.

[0025] In the present technology, the "average particle size of the pore-forming material" refers to the average particle size in the mixed state when two or more pore-forming materials having a single peak are mixed. Also, in the present technology, the average particle size is the particle size (D-50) at which the cumulative frequency is 50% in the particle size distribution measured by the laser diffraction method.

[0026] The amount of pore-forming material used in the production of olefin-based porous materials according to this technology can be freely set as long as it does not impair the function and effects of this technology. The lower limit of the amount of pore-forming material used in the raw materials of the porous material is, for example, 40% by volume or more, preferably 45% by volume or more, and more preferably 50% by volume or more. The upper limit of the amount of pore-forming material used in the raw materials of the porous material is, for example, 70% by volume or less, preferably 65% ​​by volume or less, and more preferably 60% by volume or less.

[0027] (3) Water-soluble polymer compound In the production of the olefin-based resin porous body related to this technology, a water-soluble polymer compound that acts as a lubricant may be used. Specifically, examples include polyethylene glycol, polyethylene oxide, polyethylene glycol diacrylate, polyethylene glycol dioleate, and polyethylene glycol derivatives such as polyethylene glycol diacetate, and these can be used individually or in combination of two or more.

[0028] In this technology, polyethylene glycol is particularly preferred among these materials. This is because polyethylene glycol has a high melt flow and high water solubility. When molding is performed by extrusion molding, the molecular weight of polyethylene glycol is preferably 2,000 to 30,000, more preferably 5,000 to 25,000, and even more preferably 15,000 to 25,000.

[0029] The amount of water-soluble polymer compound used in the production of olefin-based porous resins according to this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the amount of water-soluble polymer compound used in the raw materials of the porous body is, for example, 10% by volume or more, preferably 15% by volume or more, and more preferably 20% by volume or more. The upper limit of the amount of water-soluble polymer compound used in the raw materials of the porous body is, for example, 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less.

[0030] (4) Others The olefin-based porous resin material relating to this technology may contain one or more other components that can be used in general porous materials, as long as they do not impair the function or effect of this technology. For example, it may contain any components such as fillers, colorants, flame retardants, plasticizers, antistatic agents, antioxidants, ultraviolet absorbers, and antifungal agents.

[0031] 2. Method for manufacturing porous materials The method for producing an olefin-based resin porous body according to this technology involves a step of extracting and removing a pore-forming material from a raw material composition. In this technology, it is possible to freely combine other steps performed in general porous body manufacturing methods, as long as the function and effects of this technology are not impaired. For example, it can be produced by extracting and removing the pore-forming material and the water-soluble polymer compound from a molded article of a raw material composition in which a pore-forming material and a water-soluble polymer compound are mixed with a resin component and, if necessary, other components. Heating may be performed during the mixing process as needed. In addition, each raw material of the porous body can be divided and mixed as needed.

[0032] More specifically, first, the resin components to be used as raw materials, and other components as needed, are mixed and kneaded in a predetermined mixing ratio using predetermined equipment. Then, this mixture is mixed and kneaded with one or more types of pore-forming materials and water-soluble polymer compounds in a predetermined mixing ratio using predetermined equipment to obtain a raw material composition. Next, the obtained raw material composition is molded into a molded body of a predetermined shape using an extruder or the like. The obtained molded body is then immersed in an extraction solvent at a predetermined temperature to extract and remove the pore-forming materials and water-soluble polymer compounds, thereby obtaining a porous body with numerous fine bubbles. The type of extraction solvent that can be used in this technology is not particularly limited and can be freely selected depending on the type of pore-forming material and water-soluble polymer compound used. A specific example of an extraction solvent is water.

[0033] For mixing and kneading the resin components, porosity-forming agents, and water-soluble polymer compounds mentioned above, kneading equipment such as laboplast mills, single-screw or twin-screw extruders, kneaders, pressure kneaders, conkneaders, Banbury mixers, Henschel mixers, and rotor mixers can be used. No special equipment is required for this kneading, and the kneading speed is not particularly limited. The temperature during kneading is set appropriately according to the melting point of the resins used. The kneading time depends on the physical properties of the mixture, but it is sufficient if the mixture is thoroughly mixed and kneaded. The kneaded raw materials can be molded into desired shapes by extrusion, injection, pressing, rolling, blowing, etc.

[0034] The molded body, formed into the desired shape, is immersed in a solvent such as water for a predetermined time (depending on the shape and thickness of the molded body, for example, 24 to 48 hours) to extract and remove the pore-forming material and the water-soluble polymer compound. While any immersion method is acceptable, extraction and removal by immersion in water is preferred, as it brings the entire mixture into contact with the water. The temperature of the water used is not particularly limited as long as it is lower than the melting point of the resin used; however, warm water at 15 to 60°C may be used for efficient removal of the water-soluble substances.

[0035] 3. Physical properties of porous olefin resins (1)Hardness The hardness of the olefin-based resin porous material related to this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the hardness is, for example, 40 or higher on the Asker F hardness scale, preferably 45 or higher, and more preferably 50 or higher. By setting the lower limit of the Asker F hardness of the olefin-based resin porous material within this range, the durability of the porous material can be further improved.

[0036] The upper limit of hardness is, for example, 70 or less on the Asker C hardness scale, preferably 65 or less, and more preferably 60 or less. By setting the upper limit of the Asker C hardness of the olefin-based porous resin to this range, it is possible to prevent the olefin-based porous resin from becoming too hard, and for example, when the olefin-based porous resin is used as an abrasive material, damage to the object being abraded can be prevented.

[0037] In this technology, the Asker F hardness of the olefin-based porous resin material is measured using an F-type hardness tester in accordance with JIS K 6253-3. The Asker C hardness of the olefin-based porous resin material is measured using a C-type hardness tester in accordance with JIS K 7312.

[0038] (2) Tensile strength The tensile strength of the olefin-based resin porous material relating to this technology can be freely set as long as it does not impair the function and effect of this technology, but for example, it is 0.3 MPa or higher, preferably 0.4 MPa or higher, and more preferably 0.5 MPa or higher. Furthermore, there is no particular upper limit to the tensile strength of the olefin-based resin porous material relating to this technology, but it is usually 10 MPa or lower.

[0039] In this technology, the tensile strength of the olefin-based porous resin material is a value measured in accordance with JIS K 6251.

[0040] (3) Tensile elongation The tensile elongation of the olefin-based resin porous material according to this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the tensile elongation of the olefin-based resin porous material according to this technology is, for example, 50% or more, preferably 100% or more, and more preferably 150% or more. The upper limit of the tensile elongation of the porous material according to this technology is not particularly limited, but is usually 500% or less.

[0041] In this technology, the tensile elongation of the olefin-based porous resin is a value measured in accordance with JIS K 6251.

[0042] (4) Chemical resistance The porous olefin resin material according to this technology has high chemical resistance. In particular, the porous olefin resin material according to this technology is characterized by its high resistance to ozone.

[0043] 4. Applications of olefin-based porous resins The olefin-based resin porous material related to this technology can be used in all fields and for all applications due to its high quality. In particular, this technology makes it suitable for use as an abrasive or cleaning material due to its high flexibility and high ozone resistance. In particular, this technology makes it even more suitable for use as an abrasive or cleaning material when exposed to ozone water, such as when cleaning with ozone water, due to its high ozone resistance. [Examples]

[0044] The present technology will be described in more detail below based on the following examples. The examples described below are representative examples of the present technology and should not be interpreted as narrowing the scope of the present technology.

[0045] (1) Production of porous olefin resin After weighing the raw materials shown in Table 1 below, they were kneaded in a laboplast mill (temperature: 130°C, time: 10 min, rotation speed: 50 rpm). The kneaded mixture was then molded using a hand press (temperature: 130°C, time: 5 min, pressure: 40 kN), cooled with water, immersed in water to allow the pore-forming agent and water-soluble polymer compound to dissolve overnight (temperature: approximately 25°C), and then dried to produce each porous material.

[0046] (2) Fluorine gas treatment Fluorine gas-treated porous materials were produced by contacting the surface of each porous material manufactured in Examples 1 to 3 with fluorine gas. Comparative Example 1 was an example in which no fluorine gas treatment was performed.

[0047] (3) Measurement and evaluation of physical properties The physical properties of each porous material manufactured were measured and evaluated using the following methods.

[0048] [Surface modification evaluation] Process oil (Idemitsu Kosan Co., Ltd. "Diana Procell Oil PW-90") was dropped onto the fluorine gas-treated porous bodies of Examples 1-3 and the porous body of Comparative Example 1, and the contact angle was measured. A contact angle of 60° or more was evaluated as ○, a contact angle of less than 60° as △, and a case where the oil soaked into the porous body as ×.

[0049] [Ozone water resistance evaluation] The fluorine gas-treated porous bodies of Examples 1-3 and the porous body of Comparative Example 1 were immersed in ozonated water with an ozone concentration of 20 ppm for 100 hours. The changes in Asker F hardness, tensile strength, and tensile elongation before and after immersion were evaluated.

[0050] The Asker F hardness was measured using an F-type hardness tester in accordance with JIS K 6253-3. Tensile strength and tensile elongation were measured in accordance with JIS K 6251.

[0051] (4) Results The results are shown in Table 1 below.

[0052] [Table 1]

[0053] (5) Discussion As shown in Table 1 above, the porous materials of Examples 1 to 3, which underwent fluorine treatment, showed better surface modification evaluation and superior ozone resistance compared to the porous material of Comparative Example 1, which did not undergo fluorine treatment.

Claims

1. A porous olefin resin material treated with fluorine gas.

2. A porous olefin resin in which only the surface hydrogen is replaced with fluorine.

3. An olefin-based resin porous body having IR peaks on its surface originating from C-H bonds and C-F bonds.

4. An olefin-based resin porous body having open cells, according to any one of claims 1 to 3.

5. An olefin-based resin porous body according to any one of claims 1 to 3, obtained by extracting and removing a pore-forming agent from a raw material composition.

6. A polishing material or cleaning material comprising an olefin-based resin porous body according to any one of claims 1 to 3.

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