JP-7855022-B2 - Silicone porous material and method for manufacturing the same

Inventors

• 田中 佳典
• 近藤 勇史
• 増山 圭司

Assignees

• 株式会社イノアックコーポレーション

Dates

Publication Date

20260507

Application Date

20240401

Claims (4)

1. A method for manufacturing a filter comprising a silicone porous body containing organic fibers and having a three-dimensional interconnected pore structure , satisfying any one of the following (1) to (5): The manufacturing process for the aforementioned porous silicone body is as follows: A dispersion step in which a silicone raw material, a water-soluble foam-forming agent, and organic fibers are mixed to form a silicone mixture, A crosslinking step to crosslink the aforementioned silicone mixture to form a silicone molded body, The process includes an extraction and removal step of bringing the silicone molded body into contact with water to extract and remove the water-soluble bubble-forming agent. A method for manufacturing a filter characterized by the following : (1) The organic fiber is a chemical fiber. (2) The melting point of the organic fiber is 100 to 260°C. (3) The fiber length of the organic fiber is 0.2 to 10 mm. (4) The fiber diameter of the organic fiber is 1 to 100 μm. (5) The density of the porous silicone is 0.11 to 0.22 g/ cm³.
2. A cosmetic puff comprising a silicone porous body containing polyethylene fibers and having a three-dimensional interconnected pore structure , characterized in that the fiber length of the polyethylene fibers is 0.8 to 2 mm.
3. The cosmetic puff according to claim 2, wherein the fiber diameter of the polyethylene fiber is 1 to 100 μm.
4. The cosmetic puff according to claim 2 or claim 3, wherein the density of the porous silicone material is 0.11 to 0.22 g/ cm³ .

Description

This invention relates to a porous silicone body having a three-dimensional interconnected pore structure and a method for producing the same. Silicone porous materials, which have three-dimensionally interconnected pores, are excellent in flexibility and breathability, and these properties are utilized in various applications such as cosmetic puffs and various filters. Such silicone porous materials are known to be manufactured by an extraction method in which a bubble-forming agent is mixed and dispersed in the main material beforehand, and then the bubble-forming agent is removed to form bubbles (cavities). Such extraction methods are broadly classified into wet methods and dry methods. (1) In the wet method, the main material is dissolved in a solvent, a bubble-forming agent is mixed and dispersed in this mixture, and the mixture is then molded into a predetermined shape, after which the bubble-forming agent is dissolved and removed. (2) In the dry method, the main material is heated to a molten state, mixed with a bubble-forming agent, molded into a predetermined shape, and then the bubble-forming agent is dissolved and removed. Such wet and dry methods require the main material to be dissolved in a solvent or heated to dissolve it, and have drawbacks such as being time-consuming. Another extraction method is the emulsion method. This method involves mixing and dispersing a liquid main material with water and/or a water-soluble foam-forming agent, then obtaining a main material molded into a predetermined shape, and subsequently removing water or a water-soluble polymer from this main material (for example, Patent Document 1). Japanese Patent Publication No. 2017-61592 This is a schematic process diagram illustrating the method for manufacturing a porous silicone material according to the present invention. Next, the silicone porous body and its manufacturing method according to the present invention will be described with reference to preferred examples. The inventors of this application have found that in a silicone porous body formed by mixing a silicone raw material, a water-soluble bubble-forming agent, and organic fibers to obtain an uncrosslinked silicone mixture in which the bubble-forming agent is dispersed, then crosslinking this silicone mixture to form a silicone rubber substrate made of silicone resin, and finally extracting and removing the bubble-forming agent with water, the inclusion of an organic material in the silicone rubber substrate results in a robust three-dimensional interconnected pore structure and excellent tear strength. The silicone raw material may be either a one-component or two-component type, but a liquid silicone that remains liquid at room temperature is used. In the case of a two-component type, it is preferable because it allows for easy control of the timing of the crosslinking reaction and suppresses mixing during the crosslinking reaction. Furthermore, the silicone raw material may be a condensation reaction crosslinking type or an addition reaction crosslinking type. In this case, it is preferable to use an addition reaction crosslinking type silicone raw material that does not release by-products during crosslinking. The room-temperature curing silicone raw material used in this invention is a material used to create prototype molds. After adding a curing agent to the main component, it is stirred, and the air trapped during mixing is removed by vacuum degassing, followed by curing and curing. This curing involves holding the silicone raw material in the mold at room temperature for approximately one day, after which demolding is possible immediately. Any water-soluble bubble-forming material can be used as the aforementioned water-soluble bubble-forming material, provided that it is soluble in water and, when mixed with the silicone raw material at a temperature of 100°C or lower, the bubble-forming material is uniformly and stably dispersed in the silicone raw material. This bubble-forming material contains at least one water-soluble inorganic substance and at least one water-soluble organic substance. For example, water-soluble inorganic substances include NaCl (salt), KCl, CaCl, NH₄Cl , NaNO₃ , NaNO₂ , etc. Examples of water-soluble organic substances include TME (trimethylolethane), trimethylolpropane, trimethylolbutane, sucrose, soluble starch, sorbitol, glycine, or sodium salts of various organic acids (malic acid, citric acid, glutamic acid, succinic acid, etc.). Other water-soluble organic substances that can be used include polyethylene glycol derivatives such as polyethylene glycol, polyethylene glycol diacrylate, polyethylene glycol dioleate, and polyethylene glycol diacetate, compounds derived from alkyl ethers represented by formula ( 1 ) R1O ( CH2CH2O ) nR2 , and other compounds that dissolve in water and reduce viscosity relative to the resin. Here, R1 in formula (1) is a hydrocarbon group, and R2 represents hydrogen or a hydrocarbon group. F