Water- and oil-repellent surface treatment agent

Abstract

To propose a surface treatment agent having excellent water- and oil-repellency, which replaces fluorine-based surface treatment agents.SOLUTION: The problem can be solved through the discovery that employing a polymer containing 50 to 100 mol% of epichlorohydrin-derived structural units (A) and having a weight-average molecular weight of at least 100,000 affords a surface treatment agent having excellent water- and oil-repellency.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water- and oil-repellent surface treatment agent containing a polymer having structural units derived from epichlorohydrin, and to articles such as paper, fibers, and films treated with the water- and oil-repellent surface treatment agent. [Background technology]

[0002] As a surface treatment agent that imparts water and oil repellency, a fluorine-containing polymer, for example, a polymer of a polymerizable compound having a perfluoroalkyl group or a perfluoroalkenyl group, is known.

[0003] These polymers of fluorine-based compounds have the advantage of being excellent in properties such as heat resistance, oxidation resistance and weather resistance, and are widely used as surface treatment agents for textile products, leather, paper and mineral substrates.

[0004] On the other hand, fluorine-based surface treatment agents are considered to be perfluoroalkyl and polyfluoroalkyl substances (PFAS), and there are concerns that they may be harmful to humans due to their persistence in the environment and their tendency to accumulate in the biosphere.

[0005] Therefore, there is a demand for a surface treatment agent having excellent water and oil repellency to replace the fluorine compound-based surface treatment agents. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication 2015 / 151598 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a surface treatment agent having excellent water and oil repellency and which can replace fluorine compound-based surface treatment agents. [Means for solving the problem]

[0008] Means for Solving the Problems The present inventors have conducted intensive research into the above-mentioned problems and have found that by using (A) a polymer having 50 to 100 mol % of epichlorohydrin-derived structural units and having a weight-average molecular weight of 100,000 or more, a surface treatment agent having excellent water- and oil-repellency can be provided, thereby solving the above-mentioned problems.

[0009] The present invention can also be described as follows. Item 1 (A) A water- and oil-repellent surface treatment agent containing a polymer having 50 to 100 mol % of structural units derived from epichlorohydrin and having a weight-average molecular weight of 100,000 or more. Item 2. The water- and oil-repellent surface treatment agent according to Item 1, wherein the polymer is a polymer having (A) 70 to 100 mol % of structural units derived from epichlorohydrin and (B) 0 to 30 mol % of structural units derived from an oxirane monomer copolymerizable with epichlorohydrin. Item 3. The water- and oil-repellent surface treatment agent according to Item 2, wherein the structural unit derived from an oxirane monomer copolymerizable with epichlorohydrin (B) is a structural unit derived from a monomer selected from methacrylic acid glycidyl ether, allyl glycidyl ether, an alkylene oxide having 2 to 18 carbon atoms, and an alkyl glycidyl ether having 8 to 18 carbon atoms. Item 4. The water- and oil-repellent surface treatment agent according to item 1, which contains a liquid medium. Item 5. The water- and oil-repellent surface treatment agent according to Item 1, wherein the polymer has a weight-average molecular weight of 200,000 or more. Item 6. An article that has been surface-treated with the water- and oil-repellent surface treatment agent according to any one of items 1 to 5. Effect of the Invention

[0010] The present invention relates to a surface treatment agent containing a polymer (A) having 50 to 100 mol % of structural units derived from epichlorohydrin and having a weight average molecular weight of 100,000 or more, and has excellent water and oil repellency, and is therefore extremely useful as a surface treatment agent for use on paper, fibers, films, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below. The water- and oil-repellent surface treatment agent of the present invention contains (A) a polymer having 50 to 100 mol% of epichlorohydrin-derived structural units and having a weight-average molecular weight of 100,000 or more. Although not limited to the mechanism of the present invention, it is considered that the water- and oil-repellency are compatible due to the fact that epichlorohydrin accounts for most of the structural units of the polymer and chloromethyl groups exist as side chains of the polymer.

[0012] The polymer contains at least a structural unit derived from epichlorohydrin, and may contain a structural unit derived from an oxirane monomer copolymerizable with epichlorohydrin, and the molar ratio of the structural unit is 1 It is determined by H-NMR spectroscopy.

[0013] The polymer preferably contains 50 to 100 mol %, more preferably 70 to 100 mol %, and particularly preferably 90 to 100 mol %, of structural units derived from epichlorohydrin.

[0014] The polymer may contain a constituent unit derived from an oxirane monomer copolymerizable with epichlorohydrin. Examples of the oxirane monomer copolymerizable with epichlorohydrin include methacrylic acid glycidyl ether, allyl glycidyl ether, alkylene oxides having 2 to 18 carbon atoms, such as ethylene oxide, propylene oxide, and butylene oxide, and alkyl glycidyl ethers having 8 to 18 carbon atoms.

[0015] The oxirane monomer constituent unit copolymerizable with epichlorohydrin is more preferably 0 to 50 mol%, further preferably 0 to 30 mol%, and particularly preferably 0 to 10 mol%. The oxirane monomer constituent unit copolymerizable with epichlorohydrin may be composed of a constituent unit derived from one type of monomer, or may be composed of a constituent unit derived from two or more types of monomers.

[0016] When the polymer contains at least both a structural unit derived from epichlorohydrin and a structural unit derived from an oxirane monomer copolymerizable with epichlorohydrin, the structural unit derived from epichlorohydrin may be 50 to 99 mol%, may be 70 to 99 mol%, or may be 90 to 99 mol%, and the structural unit derived from the oxirane monomer copolymerizable with epichlorohydrin may be 1 to 50 mol%, may be 1 to 30 mol%, or may be 1 to 10 mol%.

[0017] The weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 200,000 or more, and more preferably 300,000 or more, and although the upper limit is not particularly limited, it is preferably 3,000,000 or less, and may be 2,000,000 or less. The weight average molecular weight is calculated by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent in terms of standard polystyrene.

[0018] The polymer can be produced by polymerizing a monomer using a catalyst capable of ring-opening polymerization of an oxirane compound. The polymerization temperature is, for example, in the range of -20 to 100°C. This polymerization may be either solution polymerization or slurry polymerization. Examples of the catalyst include a catalyst system in which organoaluminum is the main component and water, a phosphorus oxo acid compound, acetylacetone, or the like is reacted therewith, a catalyst system in which organozinc is the main component and water is reacted therewith, and an organotin-phosphate ester condensate catalyst system.

[0019] The content of the polymer in the water- and oil-repellent surface treatment agent is preferably from 1 to 95% by mass, more preferably from 5 to 60% by mass, and may be from 10 to 40% by mass.

[0020] The water- and oil-repellent surface treatment agent preferably contains a liquid medium, and examples of the liquid medium include water and an organic solvent. Examples of the organic solvent include toluene, xylene, benzene, acetonitrile, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, glyme (ethylene glycol dimethyl ether), diglyme (diethylene glycol dimethyl ether), THF (tetrahydrofuran), acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol, tripropylene glycol, and ethanol.

[0021] The content of the liquid medium in the water- and oil-repellent surface treatment agent is preferably from 5 to 99% by mass, more preferably from 40 to 95% by mass, and may be from 60 to 90% by mass.

[0022] In the water- and oil-repellent surface treatment agent, the polymer may be dissolved or dispersed in a liquid medium, because the water- and oil-repellent surface treatment agent exhibits water- and oil-repellency by coating the surface of the object with the polymer after the object is treated with the water- and oil-repellent surface treatment agent.

[0023] The water- and oil-repellent surface treatment agent may further contain a surfactant. By containing a surfactant, the dispersibility of the polymer in the liquid medium in the water- and oil-repellent surface treatment agent can be improved, and the permeability into objects such as paper, fiber, and film can be increased.

[0024] As the surfactant, an anionic surfactant, a nonionic surfactant, or a cationic surfactant can be used, and a commercially available product may also be used.

[0025] Examples of the anionic surfactant include alkylbenzenesulfonates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, and fatty acid salts.

[0026] Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polycyclic phenyl ethers, polyoxyalkylene alkyl ethers, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters.

[0027] Examples of cationic surfactants include monostearyl trimethyl ammonium chloride, monostearyl dimethyl monoethyl ammonium ethyl sulfate, mono(stearyl) monomethyl di(polyethylene glycol) ammonium chloride, monofluorohexyl trimethyl ammonium chloride, di(tallow alkyl) dimethyl ammonium chloride, and dimethyl monococonut amine acetate, and it is more preferable to use a quaternary ammonium chloride.

[0028] The surfactant is contained in an amount of preferably 0.1 to 20 parts by mass, and more preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the polymer.

[0029] The water- and oil-repellent surface treatment agent may contain additives, such as reaction initiators (e.g., thermal reaction initiators, photoreaction initiators, etc.), crosslinking assistants, defoamers, preservatives, pH adjusters, thickeners, pigments, drying speed adjusters, film-forming assistants, antifreeze agents, ultraviolet absorbers, antioxidants, antibacterial agents, preservatives, insect repellents, fragrances, and flame retardants, as necessary.

[0030] The method for producing the water- and oil-repellent surface treatment agent is not particularly limited, and any stirring device for uniformly mixing and dispersing can be used, such as an agitator, a homomixer, a pipeline mixer, a blender, etc. The polymer, liquid medium, surfactant, etc. can be added all at once or in portions, as desired, depending on the state of dissolution and dispersion.

[0031] The objects to be surface-treated with the water- and oil-repellent surface treatment agent are not limited, and examples thereof include fibers, paper, films, nonwoven fabrics, resin products, leather products, wood, metal products, stone materials, glass products, and the like. The fiber material is not particularly limited, and examples thereof include natural fibers such as cotton, hemp, silk, and wool; semi-synthetic fibers such as rayon and acetate; synthetic fibers such as nylon, polyester, polyurethane, and polypropylene; and composite fibers and blended fibers thereof. The film may be a polymer film, and examples of the film include films of polyolefin, polyester, polystyrene, polymethyl methacrylate, polyamide, polycarbonate, etc.

[0032] As a method for treating with the water- and oil-repellent surface treatment agent, a conventional method can be used without any restrictions. For example, the object is treated with the water- and oil-repellent surface treatment agent by immersion, spraying, coating, adhesion, etc., and then dried. After drying, the object may be heat-treated as necessary.

[0033] During or after the treatment with the water- and oil-repellent surface treatment agent, the polymer in the water- and oil-repellent surface treatment agent can be crosslinked. When crosslinking, it is preferable that the water- and oil-repellent surface treatment agent contains a reaction initiator such as a thermal reaction initiator or a photoreaction initiator, and can further contain a crosslinking assistant.

[0034] As the thermal reaction initiator, a radical initiator selected from organic peroxides, azo compounds, etc. is used. As the organic peroxide, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, etc., which are usually used for crosslinking, are used, and as the azo compound, azonitrile compounds, azoamide compounds, azoamidine compounds, etc., which are usually used for crosslinking, are used. The amount of radical initiator added varies depending on the type, but is usually within the range of 0.1 to 10 parts by mass based on 100 parts by mass of the polymer.

[0035] As the photoreaction initiator, radical initiators such as alkylphenones, benzophenones, acylphosphine oxides, titanocenes, triazines, bisimidazoles, oxime esters, etc. are used. The amount of these radical polymerization initiators to be added varies depending on the type, but is usually within the range of 0.01 to 5.0 parts by mass based on 100 parts by mass of the polymer.

[0036] As the crosslinking aid, any of ethylene glycol diacrylate, ethylene glycol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, allyl methacrylate, allyl acrylate, diallyl maleate, triallyl isocyanurate, maleimide, phenylmaleimide, maleic anhydride, etc. can be used. The content of the crosslinking aid is preferably within a range of 0.1 to 30 parts by mass, more preferably within a range of 0.5 to 20 parts by mass, based on 100 parts by mass of the polymer.

[0037] When the crosslinking reaction is carried out by heat, it can be carried out by heating at a temperature setting of 100 to 200° C. for about 10 to 300 seconds. In the case of ultraviolet light, a xenon lamp, a mercury lamp, a high-pressure mercury lamp, or a metal halide lamp can be used. For example, the electrolyte is irradiated with light having a wavelength of 365 nm and a light intensity of 1 to 50 mW / cm. 2 This can be done by irradiating with light for 0.1 to 30 minutes. The crosslinking reaction may be carried out simultaneously with drying after treatment of the object with the above-mentioned water- and oil-repellent surface treatment agent or during heat treatment after drying, or may be carried out after drying after treatment of the object with the water- and oil-repellent surface treatment agent or after heat treatment after drying.

[0038] The present invention will be described in detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as it does not deviate from the gist of the present invention.

[0039] <Polymer analysis> The copolymerization composition of the polyether polymer obtained in Examples 1 to 3 and Comparative Example 1 was determined by dissolving the polyether polymer in deuterated chloroform, determining the integral value of each unit by 1H-NMR, and calculating the composition ratio from the calculation result. The apparatus used was JNM GSX-270 manufactured by JEOL Ltd. The weight average molecular weight of the polyether polymers obtained in the Examples and Comparative Examples was determined by gel permeation chromatography (GPC) in the following manner. Equipment: Shimadzu Corporation GPC system Column: Showa Denko KF-806L, KF-803L, KF-801 Detector: Differential refractometer Solvent: Tetrahydrofuran Flow rate: 1mL / min Column temperature: 40℃ Molecular weight standard: Standard polystyrene manufactured by Showa Denko K.K.

[0040] <Production of Polymerization Catalyst> Preparation of polymerization catalyst: 10 g of tributyltin chloride and 35 g of tributyl phosphate were placed in a three-necked flask equipped with a stirrer, a thermometer, and a condenser, and the mixture was heated at 250°C for 20 minutes while stirring under a nitrogen stream to remove the distillate, and a solid condensate was obtained as the residue at room temperature. This was used as a polymerization catalyst (hereinafter referred to as the condensate catalyst).

[0041] Example 1 The inside of a 1 L glass reactor was replaced with nitrogen, and 0.4 g of the above condensation catalyst, 70 g of epichlorohydrin (also referred to as EP), and 280 g of normal hexane as a solvent were charged. The polymerization reaction was stopped after 4 hours while maintaining the reaction temperature at 25°C. The polymer was taken out and then dried under reduced pressure at 40°C for 8 hours to obtain 60 g of a polyether polymer. The polymerization composition of the obtained polyether polymer was epichlorohydrin only (100 mol%), and the weight average molecular weight was 1 million.

[0042] Example 2 The inside of a 1 L glass reactor was replaced with nitrogen, and 0.2 g of the above condensation catalyst, 27.5 g of epichlorohydrin (also written as EP), 12.5 g of ethylene oxide (also written as EO), and 40 g of normal hexane as a solvent were charged. The polymerization reaction was stopped after 4 hours while maintaining the reaction temperature at 25°C. The polymer was taken out and then dried under reduced pressure at 40°C for 8 hours to obtain 25.0 g of a polyether copolymer. The copolymer composition of the obtained polyether polymer was 50 mol% epichlorohydrin: 50 mol% ethylene oxide, and the weight average molecular weight was 1 million.

[0043] Example 3 The inside of a 1 L glass reactor was replaced with nitrogen, and 0.2 g of the above condensation catalyst, 30 g of epichlorohydrin (also written as EP), 10 g of propylene oxide (also written as PO), and 40 g of normal hexane as a solvent were charged. The polymerization reaction was stopped after 5 hours while maintaining the reaction temperature at 25°C. The polymer was taken out and then dried under reduced pressure at 40°C for 8 hours to obtain 11.0 g of a polyether copolymer. The copolymer composition of the obtained polyether polymer was 70 mol% epichlorohydrin: 30 mol% propylene oxide, and the weight average molecular weight was 420,000.

[0044] Comparative Example 1 Commercially available PEO (polyethylene glycol 2000000 from Fujifilm Wako Pure Chemical Industries, Ltd.) was used.

[0045] <Evaluation> In order to evaluate the water and oil repellency of the polyether polymers of Examples 1 to 3 and Comparative Example 1, coating films were prepared as follows. The polyether polymers of Examples 1 to 3 and Comparative Example 1 were dissolved in tetrahydrofuran to a solid concentration of 5% by mass, then coated onto a polyethylene terephthalate film with an applicator and heated and dried at 40°C for 5 hours to obtain a coating film with a thickness of 20 μm.

[0046] <Film forming properties> The film-forming properties of the coating film were evaluated by visually inspecting the coating film after heating, based on the following criteria: 〇: Smooth, no bubbles, etc. ×: Smoothness, bubbles, etc.

[0047] <Contact angle> For the coating films obtained with the polyether polymers of the Examples and Comparative Examples, the contact angle (25°C) was measured to evaluate the water- and oil-repellency. Specifically, the water- and oil-repellency-imparted surface of each coating film was used as the test surface, and the contact angle of pure water (about 1 to 2 μl) and hexadecane (about 1 to 2 μl) was measured using a contact angle measuring device (fully automatic contact angle meter "DMo-702" manufactured by Kyowa Interface Science Co., Ltd.). The measurement results are shown in Table 1, with the N number set to three, and the average value of the contact angle after 2 minutes. Note that if the contact angle of water is 70° or more, and if the contact angle of hexadecane is 15° or more, it can be said that the coating film has water- and oil-repellency, and the larger the contact angle (unit: °), the better the water- and oil-repellency.

[0048] [Table 1]

[0049] Table 1 shows that the coating films obtained using the polyether polymers of Examples 1 to 3 have both water repellency and oil repellency compared to Comparative Example 1, and are useful as water- and oil-repellent surface treatment agents. [Industrial Applicability]

[0050] Since the surface treatment agent containing the polymer of the present invention has excellent water and oil repellency, it is extremely useful as a surface treatment agent for use on objects such as paper, fibers, and films.

Claims

1. (A) A water- and oil-repellent surface treatment agent containing a polymer having 50 to 100 mol % of structural units derived from epichlorohydrin and having a weight-average molecular weight of 100,000 or more.

2. 2. The water- and oil-repellent surface treatment agent according to claim 1, wherein the polymer is a polymer having (A) 70 to 100 mol % of structural units derived from epichlorohydrin and (B) 0 to 30 mol % of structural units derived from an oxirane monomer copolymerizable with epichlorohydrin.

3. The water- and oil-repellent surface treatment agent according to claim 2, wherein the structural unit derived from an oxirane monomer copolymerizable with epichlorohydrin (B) is a structural unit derived from a monomer selected from methacrylic acid glycidyl ether, allyl glycidyl ether, an alkylene oxide having 2 to 18 carbon atoms, and an alkyl glycidyl ether having 8 to 18 carbon atoms.

4. The water- and oil-repellent surface treatment agent according to claim 1, which contains a liquid medium.

5. 2. The water- and oil-repellent surface treatment agent according to claim 1, wherein the polymer has a weight average molecular weight of 200,000 or more.

6. An article whose surface has been treated with the water- and oil-repellent surface treatment agent according to any one of claims 1 to 5.

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