resin foam

Abstract

The present invention provides a resin foam primarily composed of polyolefin resin, which has been modified to be both hydrophilic and oleophobic. [Solution] The resin foam of the present invention comprises a polyolefin resin, an oil repellent, and a surfactant, wherein the amount of the oil repellent is 2 to 10 parts by mass per 100 parts by mass of the polyolefin resin, and the amount of the surfactant is 0.5 to 6 parts by mass per 100 parts by mass of the polyolefin resin.

Description

Technical Field

[0001] The present invention relates to a resin foam.

Background Art

[0002] Conventionally, polyurethane foam has been widely used as a sponge for dishwashing, a cushioning material for sofas and bedding (such as mattresses and pillows), etc. (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, polyurethane foam is inferior in chemical resistance and deteriorates by chlorine disinfection. On the other hand, as a material having excellent chemical resistance, a foam mainly composed of a polyolefin resin is known. The polyolefin resin is lipophilic and hydrophobic.

[0005] On the other hand, it is desirable that a sponge for dishwashing, etc. is hydrophilic and oil-repellent. Therefore, an object of the present invention is to provide a resin foam mainly composed of a polyolefin resin modified to be hydrophilic and oil-repellent.

Means for Solving the Problems

[0006] In order to achieve the above object, the resin foam of the present invention contains a polyolefin resin, an oil-repellent agent, and a surfactant, the blending amount of the oil-repellent agent is 2 parts by mass to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin, The amount of the surfactant blended is 0.5 to 6 parts by mass per 100 parts by mass of the polyolefin resin. [Effects of the Invention]

[0007] The resin foam of the present invention is modified to be hydrophilic and oil-repellent by adding a predetermined amount of oil-repellent agent and surfactant to a polyolefin resin. [Modes for carrying out the invention]

[0008] The resin foam of the present invention comprises a polyolefin resin, an oil repellent, and a surfactant. The resin foam may consist only of the polyolefin resin, the oil repellent, and the surfactant, or it may further contain other components (for example, fillers (including colorants such as pigments)).

[0009] The polyolefin resin is not particularly limited, and examples include polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polytetrafluoroethylene, ethylene-propylene copolymer, ethylene·1-octene copolymer, poly-4-methyl-1-pentene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer, and the like. The polyolefin resin may be used alone or in combination of two or more types.

[0010] The amount of the polyolefin resin in the total amount of the resin foam may be, for example, the remainder of the other components.

[0011] The oil repellent is not particularly limited and includes, for example, silicone-based oil repellents such as silicone concentrate, polymethylsiloxane, methylphenylpolysiloxane, and methylhydrodienepolysiloxane; fluorine-based oil repellents such as polychlorotrifluoroethylene, polytetrafluoroethylene, tetrafluoroethylene, and vinylidene fluoride; wax-based oil repellents using beeswax or paraffin; and metal salt-based oil repellents using salts of zirconium and fatty acids or aluminum and fatty acids. The oil repellent may be used alone or in combination of two or more types.

[0012] The oil-repellent agent may be prepared in-house or a commercially available product may be used. Examples of commercially available products include BY27-202 from DuPont-Toray Specialty Materials, Inc., which is a silicone concentrate (ultra-high molecular weight siloxane polymer (masterbatch)); TSE200A from Momentive Performance Materials, Inc., which is mainly methylsiloxane; and paraffin chloride from Ajinomoto Fine Techno, Inc.

[0013] The amount of the oil-repellent agent in the total amount of the resin foam is 2 to 10 parts by mass per 100 parts by mass of the polyolefin resin.

[0014] The surfactant is not particularly limited and includes, for example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. The surfactant may be used alone or in combination of two or more types.

[0015] Examples of the anionic surfactants include alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; dialkyl sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate and sodium diisotridecyl sulfosuccinate; dipolyoxyethylene alkyl ether sulfosuccinates such as sodium di(polyoxyethylene 2-ethylhexyl ether) sulfosuccinate and sodium di(polyoxyethylene isotridecyl ether) sulfosuccinate; polyoxyalkylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene myristyl ether sulfate; alkyl sulfates such as sodium lauryl sulfate, sodium higher alcohol sulfate, triethanolamine lauryl sulfate, and ammonium lauryl sulfate; fatty acid salts such as potassium oleate, sodium oleate, and sodium semi-hydrogenated beef tallow fatty acid; and the like.

[0016] Examples of the cationic surfactants include alkyltrimethylammonium salts such as lauryltrimethylammonium chloride, cetyltrimethylammonium bromide, and stearyltrimethylammonium chloride; and alkyldimethylbenzylammonium salts such as stearyldimethylbenzylammonium chloride, benzalkonium chloride, and lauryldimethylbenzylammonium chloride.

[0017] Examples of the nonionic surfactants include glycerin fatty acid esters such as glycerin monooleate; alkylolamides such as coconut oil fatty acid monoethanolamide and lauryl acid diethanolamide; polyoxyalkylphenyl ethers such as polyoxyethylene alkylphenyl ether; polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether; polyethylene glycol fatty acid esters such as polyethylene glycol distearate; sorbitan fatty acid esters such as sorbitan monocaprate, sorbitan monostearate, and sorbitan distearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate; polyoxyethylene sorbitan fatty acid esters; polyoxyethylene polyoxypropylene alkyl ether; glycol ether; and the like.

[0018] Examples of the aforementioned amphoteric surfactants include alkyl betaines such as coconut oil alkyl betaine; alkylamide betaines such as lauryldimethylaminoacetic acid betaine; imidazolines such as Z-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine; glycines such as polyoctyl polyaminoethylglycine; and the like.

[0019] The amount of the surfactant blended in the total amount of the resin foam is 0.5 to 6 parts by mass per 100 parts by mass of the polyolefin resin.

[0020] The resin foam is modified to be hydrophilic and oil-repellent by containing the predetermined amount of the oil-repellent agent and the surfactant with respect to the polyolefin resin. The hydrophilicity and oil-repellency of the resin foam can be evaluated, for example, by the contact angle measured by the droplet method. For example, the resin foam has a water contact angle measured by the droplet method of 20° to 80°, and an oil contact angle measured by the droplet method of 30° to 80°. Examples of the water used for measuring the contact angle include tap water, ion-exchanged water, pure water, and the like. Further, examples of the oil used for measuring the contact angle include highly refined industrial oils such as Shell Omala S2 G manufactured by Shell Lubricants Japan Co., Ltd.

[0021] The cell structure of the resin foam may be closed cells or open cells.

[0022] The resin foam can be obtained, for example, by the method shown below, but is not limited to this method.

[0023] First, the polyolefin resin, the oil-repellent agent, the surfactant, the foaming agent, the crosslinking agent, and, if necessary, a foaming aid, a filler, etc. are kneaded by a heated mixing roll, a pressure kneader, an extruder, etc. to obtain a compound.

[0024] Examples of the foaming agent include azo compounds such as azodicarbonamide and barium azodicarboxylate; nitroso compounds such as dinitrosopentamethylenetetramine and trinitrotriethylenetriamine; hydrazide compounds such as p,p'-oxybisbenzenesulfonylhydrazide; sulfonyl semicarbazide compounds such as p,p'-oxybisbenzenesulfonyl semicarbazide and toluenesulfonyl semicarbazide; and the like.

[0025] Examples of the crosslinking agents include organic peroxides such as ketone peroxides, dialkyl peroxides, hydroperoxides, peroxyesters, peroxy monocarbonates, diacyl peroxides, peroxycarbonates, peroxyketals, and dicumyl peroxides.

[0026] The foaming aid can be appropriately selected according to the type of foaming agent, and examples include compounds mainly composed of urea; metal oxides such as zinc oxide and lead oxide; compounds mainly composed of salicylic acid, stearic acid, etc.

[0027] Examples of fillers include metal oxides such as zinc oxide, titanium oxide, calcium oxide, magnesium oxide, and silicon oxide; carbonates such as magnesium carbonate and calcium carbonate; fibrous materials such as pulp; various dyes, pigments, and fluorescent substances; rubber compounding agents; and the like.

[0028] Next, the compound is filled into the mold and filled with 20 kgf / cm². 2 (20 × 0.098 MPa) ~ 150 kgf / cm² 2 The mixture is heated at 140°C to 170°C for 40 to 80 minutes under sealed pressure of (150 × 0.098 MPa). During this pressurization and heating process, the foaming agent and the crosslinking agent are decomposed.

[0029] Next, the resin foam is obtained by opening the mold.

[0030] Furthermore, the aforementioned resin foam may be made into a continuous-cell foam by compressing it with twin-screw metal rolls to burst the air bubbles (decompose the air bubble membrane).

[0031] The applications of the aforementioned resin foam are not particularly limited, but examples include sponges for washing dishes, foams for sofas and beds, camping mats, and other foams for which regular chlorine disinfection is desirable. [Examples]

[0032] For compounds with compositions shown in Table 1 or Table 2, resin foams of Examples 1 to 10 and Comparative Examples 1 to 8 were obtained using the methods exemplified in the embodiments for carrying out the invention described above.

[0033] The contact angles of the resin foams of Examples 1-10 and Comparative Examples 1-8, measured by the droplet method, are shown in Tables 1 and 2. The contact angles are the average values ​​of three measurements taken by dropping droplets (water or oil droplets) onto the surface of the resin foam. Tap water was used for the water used in the contact angle measurement, and Shell Omala S2 G, manufactured by Shell Lubricants Japan Co., Ltd., was used for the oil.

[0034] [Table 1]

[0035] [Table 2]

[0036] As shown in Table 1, the resin foams of Examples 1 to 10 were modified to be both hydrophilic and oleophobic, with water contact angles of 20° to 80° and oil contact angles of 30° to 80° as measured by the droplet method. On the other hand, as shown in Table 2, Comparative Example 1, which did not contain an oil repellent or surfactant, had a water contact angle of 120°, indicating poor hydrophilicity, and an oil contact angle of 10°, indicating poor oleophobicity. Comparative Example 2, which did not contain a surfactant, also had a water contact angle of 100°, indicating poor hydrophilicity. Comparative Example 3, which contained a small amount of oil repellent, also had a water contact angle of 100°, indicating poor hydrophilicity, and an oil contact angle of 20°, indicating poor oleophobicity. Furthermore, Comparative Example 4, which did not contain a surfactant, also had a water contact angle of 100°, indicating poor hydrophilicity. Furthermore, in Comparative Examples 5-8, where no oil repellent was added or only a small amount of oil repellent was added, the oil contact angle was 10° or 20°, indicating poor oil repellency.

[0037] Although the present invention has been described above with reference to embodiments and examples, the present invention is not limited to the above embodiments and examples. Various modifications to the configuration and details of the present invention can be understood by those skilled in the art within the scope of the present invention.

Claims

1. It contains a polyolefin resin, an oil repellent, and a surfactant. The amount of the oil-repellent agent is 2 to 10 parts by mass per 100 parts by mass of the polyolefin resin. The amount of the surfactant blended is 0.5 to 6 parts by mass per 100 parts by mass of the polyolefin resin, in a resin foam.

2. The resin foam according to claim 1, wherein the oil-repellent agent comprises a silicone concentrate.

3. The resin foam according to claim 1 or 2, wherein the contact angle of water measured by the droplet method is 20° to 80°, and the contact angle of oil measured by the droplet method is 30° to 80°.

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