JP6527800B2 - Filter paper for filter and manufacturing method thereof - Google Patents

Description

  The present invention relates to a filter material for an air filter, particularly a filter paper for an air filter used to filter impurities in a gas in a semiconductor, liquid crystal, clean room for bio / food industry, clean bench etc, or an air filter for building air conditioning, Alternatively, the present invention relates to a filter paper for liquid filters used in the fields of electronics, chemicals, beverages / food, water treatment and the like.

  Conventionally, filter paper for air filters to efficiently collect and remove submicron or micron-sized particles in air, or liquid filter to efficiently collect and remove particulates in water and solvents For filter paper, glass fibers having an average fiber diameter of several micrometers to several tens of micrometers are used as a main component. However, glass fiber itself does not have self-adhesion like pulp fiber used for general paper, and as it is, there is no practical strength at the time of post-processing and use, and glass fiber is scattered during ventilation etc. Problems will arise.

  Conventionally, in order to solve this problem, a method of applying an organic binder to a glass fiber substrate is used. Here, examples of the organic binder to be used include acrylic resin, epoxy resin, polyvinyl alcohol, urethane resin and the like. However, when it is necessary to increase the strength of the filter medium by this method, it is necessary to increase the binder adhesion amount, but when the adhesion amount is increased, the web-like film of the binder increases between the glass fibers, and the filtration efficiency of the filter paper decreases. In particular, in the case of filter paper for air filters, there is a market demand for flame retardancy with respect to the filter paper, but if the amount of adhesion of the organic binder is increased, the filter paper becomes easy to burn and the amount of adhesion is limited. By the way, the binder adhesion amount is less than about 10% by mass to the base material in ordinary filter media for air filters, and in particular, in the filter media for high performance and super performance air filters such as HEPA / ULPA, the amount of combustibles is 7% by mass in MIL specification It is prescribed as follows.

  Also, in recent years, with the increase in air volume of air filters, mini pleating of filter media has progressed to ensure filter paper strength, and also in terms of filtration performance, for the purpose of reducing running costs of blowers used in clean rooms, clean benches, etc. There is a growing demand for improvement in the filtration efficiency of filter paper. In order to increase the filtration efficiency of the filter paper, there is a method of reducing the fiber diameter of the glass fiber. However, the finer the fiber diameter, the higher the filtration resistance of the filter paper, and the higher the running cost of the blower. In general, there is a trade-off relationship between the reduction of filtration resistance and the improvement of filtration efficiency.

  As a method of improving the filtration efficiency of the filter paper for air filters having glass fibers as its main fibers, a method of adhering a binder and a silicone resin to fibers constituting the filter paper (see, for example, Patent Document 1), filter paper is constructed. A method has been proposed in which a binder, a fluorocarbon resin and a silicone resin are attached to fibers (see, for example, Patent Document 2).

  In addition, to the same problem, in the process of producing filter paper, after preparing the glass fiber slurry with acidity, a method is proposed to make the pH about 6 to 9 by adding a pH adjuster in the headbox. (See, for example, Patent Document 3).

  On the other hand, as a method of improving the filtration efficiency of filter paper in a filter paper for liquid filter, it is a non-woven filter medium in which glass fiber and bicomponent fiber are mixed and these are thermally bonded. A filter medium which is a polyethylene terephthalate / polyethylene terephthalate having a core structure has been proposed (see, for example, Patent Document 4).

JP-A-2-41499 JP-A-2-175997 WO 2004/940038 JP 2015-37783

  However, in the methods of Patent Documents 1 and 2, the component of the silicone resin attached to the filter paper volatilizes in a minute amount when the filter is used, adheres to the product in the process of making electronic components such as LSI and liquid crystal, and greatly reduces the product yield. There's a problem.

  Moreover, in the embodiment of the method of Patent Document 3, since the binder is not used at the time of production of the filter medium, the filter medium obtained here does not have sufficient strength required for practical use. Is easily estimated.

  In the method of Patent Document 4, since only a two-component fiber is used as a binder, the retention of glass fiber is weak, and there is a problem that the glass fiber is dropped when used as a liquid filter. In filter paper mainly composed of glass fiber, the use of an organic binder is essential.

  Therefore, an object of the present invention is to provide a filter paper for filter with improved filtration efficiency without increasing the filtration resistance as compared with the current filter paper.

  As a result of intensive investigations, the present inventors have found that the above-mentioned problems can be solved by depositing an organic binder and sorbitol polyglycidyl ether in filter paper mainly composed of glass fibers, and complete the present invention. The That is, the filter paper for filters according to the present invention is the filter paper mainly composed of glass fibers, wherein the glass fibers comprise (1) an organic binder and sorbitol polyglycidyl ether, (2) an organic binder, sorbitol polyglycidyl ether And a cross-linked product thereof, or (3) a cross-linked product of an organic binder and sorbitol polyglycidyl ether is attached.

  In the filter paper for filters according to the present invention, the pressure loss is preferably 500 Pa or more. Sorbitol polyglycidyl ether works effectively to reduce the web-like film of the organic binder for filter paper with a large pressure loss and a fine eye.

In the filter paper for filters which concerns on this invention, the water repellent may adhere to the said glass fiber. The filter paper filter according to the present invention, the organic binder is an epoxy resin, a styrene - butadiene resin, vinyl acetate resin, ethylene - vinyl acetate resins, polyolefin resins, is preferably a polyvinyl alcohol or a urethane resin.

  The method for producing filter paper according to the present invention is a process for producing a wet paper by wet papermaking of a slurry in which filter medium-constituting fibers containing the glass fibers are dispersed, in the method for producing filter paper mainly comprising glass fibers. A step of simultaneously or separately attaching an organic binder and sorbitol polyglycidyl ether to a wet paper web obtained by wet papermaking; and drying the wet paper onto which the organic binder and sorbitol polyglycidyl ether are attached; It is characterized by having.

  In the method for producing filter paper for filters according to the present invention, in the step of drying the wet paper on which the organic binder and sorbitol polyglycidyl ether are attached, the organic binder and sorbitol polyglycidyl ether crosslink. .

  In the method for producing filter paper according to the present invention, the organic binder and sorbitol polyglycidyl ether are preferably adhered to the wet paper before the wet paper is dried. Sufficient effect is obtained.

  In the method for producing filter paper according to the present invention, the ratio of the adhesion amount of sorbitol polyglycidyl ether to the organic binder is preferably 0.2 to 20% by mass. In this range, an effect according to the compounding amount is obtained.

In the method of manufacturing the filter paper for a filter according to the present invention, the ratio of the adhesion amount of the organic binder to the filter medium constituting fiber is preferably 2 to 10% by mass on a dry basis. While suppressing formation of the web-like film of an organic type binder, sufficient strength of a filter medium is securable. In the method for producing filter paper according to the present invention, the organic binder is a latex or solution of an epoxy resin, a styrene-butadiene resin, a vinyl acetate resin, an ethylene-vinyl acetate resin, a polyolefin resin, a polyvinyl alcohol or a urethane resin. Is preferred.

  The filter paper of the present invention can provide a filter paper with improved filtration efficiency as an air filter or a liquid filter without increasing the filtration resistance as compared with the current filter papers.

  EXAMPLES The present invention will next be described in detail by way of embodiments, which should not be construed as limiting the present invention. The embodiment may be variously modified as long as the effects of the present invention are exhibited.

  The filter paper for filters according to the present embodiment is a filter paper mainly composed of glass fibers, which comprises (1) an organic binder and sorbitol polyglycidyl ether, (2) an organic binder, sorbitol polyglycidyl ether, and the like to glass fiber. Or a crosslinked product of (3) an organic binder and sorbitol polyglycidyl ether.

The sorbitol polyglycidyl ether used in the filter paper for filters of the present invention is a polyfunctional epoxy compound having a molecular formula C ₁₈ H ₃₀ O ₁₀ and a molecular weight of 406.43. Sorbitol polyglycidyl ether is used as a crosslinker / insolubilizer for water-soluble resins, a modifier for synthetic resins, an adhesion improver, etc. because of its excellent reactivity and water solubility.

  The present invention makes it possible to produce a novel filter medium with improved filtration performance by attaching the sorbitol polyglycidyl ether to the glass fibers constituting the filter paper for filter.

  Sorbitol polyglycidyl ether functions to crosslink between the surface of the filter paper fiber and the organic binder molecule, or between the organic binder molecule and the organic binder molecule. As a result, it has a function to greatly improve the strength property in order to strengthen the bonding between fibers. In the conventional filter paper, the binder which does not participate in the binding between the fibers and the binder molecules forms a web-like membrane between the fibers and blocks the filter medium, which causes an increase in filtration resistance and a decrease in filtration efficiency. . However, sorbitol polyglycidyl ether more effectively crosslinks between the fiber and the binder molecule or between the binder molecule and the binder molecule in a three-dimensional manner, thereby reducing the web-like film which blocks the filter medium, As a result, it is considered that an increase in filtration resistance is prevented and the filtration efficiency is enhanced. Therefore, the adhesion form to glass fiber is (1) organic binder and sorbitol polyglycidyl ether, (2) organic binder, sorbitol polyglycidyl ether and crosslinked products thereof, or (3) organic binder and sorbitol poly Although there are cross-linked products with glycidyl ether, a form containing the cross-linked product is preferred.

  In a filter medium, 0.2-20 mass% is preferable, and, as for the ratio of the adhesion amount of sorbitol polyglycidyl ether with respect to an organic type binder, 1-10 mass% is more preferable. If the amount is less than 0.2% by mass, the effect is small, and if the amount is more than 20% by mass, the effect more than the addition to the addition is not expected and the cost increases.

  Further, even if sorbitol polyglycidyl ether is used alone as a filter medium-constituting fiber (hereinafter also referred to as a base material), there is no effect to improve the filtration efficiency, and it is necessary to use an organic binder in combination. Here, as the organic binder to be used, an acrylic ester resin, an epoxy resin, a styrene-butadiene resin, a vinyl acetate resin, an ethylene-vinyl acetate resin, a polyolefin resin, a polyvinyl alcohol, which is usually used for a filter medium A latex or solution of a urethane resin can be used, and the ratio of the adhesion amount of the organic binder to the substrate is preferably 2% by mass to 10% by mass, and more preferably 3% by mass to 7% by mass. is there. When the amount is less than 2% by mass, sufficient strength as filter paper can not be obtained, and when the amount is more than 10% by mass, a web-like film of a binder is easily formed, and the adhesion effect of the sorbitol polyglycidyl ether of the present invention becomes low. As for the strength of the filter paper, in the case of the filter paper for air filter, it is preferable that the tensile strength shown in MIL spec MIL-F-51079C is 0.44 kN / m or more in the longitudinal direction and 0.35 kN / m or more in the transverse direction. There is no particular strength shown in the case of liquid filter paper, but it is necessary to have a practical strength or higher.

  In the case of using the filter paper of the present embodiment for an air filter, even if a water repellent is further added according to the request, the effect is exhibited without change. Here, as the water repellent, a generally used fluorine-based water repellent, wax-based water repellent, alkyl ketene dimer or a mixture of these water repellents can be used. 1-40 mass% is preferable, and, as for the ratio of the adhesion amount of the water repellent with respect to the organic type binder in a filter medium, 3-20 mass% is more preferable. If the amount is less than 1% by mass, it is difficult to obtain sufficient water repellency, and if it exceeds 40% by mass, the strength of the filter medium may be reduced.

  In the present embodiment, glass fibers having an average fiber diameter of 0.2 to 20 μm are used as main fibers. Glass fibers include glass wool and chopped glass fibers. Glass wool is a wool-like glass fiber manufactured by a flame drawing method or a rotary method, and the fiber diameter is about 0.2 to 6 μm. In addition, the chopped glass fiber is a glass fiber obtained by melt spinning and is cut with the fiber length of about 3 to 20 mm, and the fiber diameter is about 6 μm to 20 μm. According to the filtration performance and other physical properties of the filter paper required, it can be suitably selected from glass fibers having various fiber diameters. There is a form of glass wool alone, chopped glass fiber alone, or a mixture of glass wool and chopped glass fiber. As the glass composition, the majority of filter applications are borosilicate glass, and among these, C glass having acid resistance and E glass (alkali-free glass) having electrical insulation are included. In the field of air filters, low boron glass fibers and silica glass fibers can also be used for the purpose of preventing boron contamination in semiconductor processes and the like. In addition, the main fiber in this embodiment shows the thing of the fiber which occupies 70 mass% or more of all the raw material fiber combination. In addition to main fibers, organic synthetic fibers may be, for example, vinylon main fibers, aramid fibers, carbon fibers, polyester fibers, rayon fibers, polypropylene fibers, polyester fibers, acrylic fibers, etc., or natural organic fibers or wood, depending on the purpose. Blends of pulp, cotton linter fibers, hemp fibers, etc., or inorganic fibers other than glass fibers, such as rock wool, alumina fibers, silica-alumina fibers, etc., are also possible.

  By changing the fiber diameter of the glass fiber constituting the filter paper, fine filter paper for precision filtration can be made from coarse filter paper. The coarseness of the filter paper can be indicated by the average pore diameter, air permeability, pressure loss, etc. of the filter paper. For example, the pressure drop of coarse filter paper is low and the pressure drop of fine filter paper is high. Also, the air permeability of the coarse filter paper is high and the air permeability of the fine filter paper is low.

  From the coarse filter paper with low pressure drop to the fine filter paper with high pressure drop for precision filtration, although there is the adhesion effect of the sorbitol polyglycidyl ether of the present invention, the filter paper with pressure loss of 500 Pa or more is better It is effective, and more effective for filter paper with a pressure drop of 1000 Pa or more. This is because as the filter paper with higher pressure loss becomes finer, it becomes easier to be covered with the web-like film of the organic binder, but the sorbitol polyglycidyl ether works effectively for the reduction of the web-like film. . The upper limit of the pressure loss is not particularly limited, and is, for example, 3000 Pa.

  Moreover, the filter medium which concerns on this embodiment can be obtained with the following manufacturing methods. That is, filter medium-constituting fibers containing glass fibers are dispersed in water using a pulper or the like. In the dispersion process of these raw material fibers, in order to improve the dispersibility, a method of adjusting in pH 2 to 4 with sulfuric acid acidity is adopted, but a surfactant such as a dispersing agent may be used at pH neutrality. Next, this slurry is subjected to wet paper making with a paper machine to obtain wet paper.

  Next, the above-mentioned organic binder, sorbitol polyglycidyl ether, if necessary, a water repellent agent and the like are adhered to the wet paper, and then dried. The effect is low even if the sorbitol polyglycidyl ether compound is applied after drying the wet paper, and it is desirable to apply it before the wet paper is dried. Even if the organic binder, sorbitol polyglycidyl ether, and the water repellent are each deposited alone, or even when these agents are simultaneously deposited, the effect is the same even if a mixed solution of these agents is deposited. .

  There is no particular limitation on the method of applying the adhesion liquid such as organic binder, sorbitol polyglycidyl ether, water repellent, etc., but a method of immersing the wet paper in the adhesion liquid, a method of spraying on the wet paper, adhesion to the roll There is a method of adhering the liquid and transferring it to a wet paper. As a drying method, it is desirable to dry at 110 to 150 ° C. using a hot air drier, a roll drier or the like.

  EXAMPLES The present invention will next be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Moreover, unless otherwise indicated, "part" and "%" in an example show a "mass part" and "mass%."

Example 1
63% by mass of glass wool with an average fiber diameter of 0.50 μm (manufactured by Johnmanville), 32% by mass of glass wool with an average fiber diameter of 2.70 μm (manufactured by Johnman Building), 11 μm in average fiber diameter, 6 μm in fiber length 5% by mass (manufactured by Owens Corning Co., Ltd.) was deagglomerated with a pulper at a concentration of 0.5% and sulfuric acid acidity pH 2.5, followed by paper making with a paper machine to obtain a wet paper. Next, as an adhesion liquid composition, polyacrylic ester 1.85 mass% (trade name: biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), sorbitol polyglycidyl ether 0.0037 mass% (against binder 0.2 mass%) (commodity Name: SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion liquid is applied to a wet paper, then dried with a dryer at 130 ° C, and the ratio of the adhesion amount of the adhesion liquid component is 6.10% at a basis weight of 70 g / m ² Filter paper was obtained. In addition, how to obtain | require the ratio of the adhesion amount of an adhesion liquid component is as follows. First, the mass of the base material is determined, and the base material is heated in an electric furnace at 525 ° C. for 30 minutes to burn the adhering liquid component (glass fiber does not burn), and the base material mass before and after combustion of the base material The obtained combustible (%) was taken as the ratio of the adhesion amount of the adhesion liquid component. The same applies to the following examples and comparative examples. In addition, the ratio of the adhesion amount of each component contained in adhesion liquid can be calculated as a thing according to the content ratio of each component of adhesion liquid.

(Example 2)
The composition of the adhesive solution in Example 1 is 1.85% by mass of polyacrylic ester (trade name: Biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.056% by mass of sorbitol polyglycidyl ether (3% by mass of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.15% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 3)
The composition of the adhesive solution in Example 1 is 1.85 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.093 mass% of sorbitol polyglycidyl ether (5 mass% of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.20% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 4)
The composition of the adhesive solution in Example 1 is as follows: 1.85 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.37 mass% of sorbitol polyglycidyl ether (20 mass% to binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.18% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 5)
The composition of the adhesive solution in Example 1 is 1.85% by mass of polyacrylic ester (trade name: Biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.56% by mass of sorbitol polyglycidyl ether (30% by mass of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.02% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 6)
The composition of the adhesive solution in Example 1 is 1.85% by mass of polyacrylic ester (trade name: Viniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.00093% by mass of sorbitol polyglycidyl ether (relative to 0.05% by mass of binder) ) (Trade name: SR-SEP, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) In the same manner as in Example 1, a filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.26% was obtained .

(Example 7)
The composition of the adhesive solution in Example 1 is 1.85% by mass of polyacrylic ester (trade name: Biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.056% by mass of sorbitol polyglycidyl ether (3% by mass of binder) Brand name: SR-SEP, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., 0.11% by mass of a fluorine-based water repellent (against binder 6% by mass) (trade name: Asahi Guard AG-E061, manufactured by Asahi Glass Co., Ltd.) In the same manner as in Example 1, a filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.24% was obtained.

(Example 8)
The composition of the adhesive liquid in Example 1 is 3.08 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.092 mass% of sorbitol polyglycidyl ether (3 mass% to binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 9.80% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 9)
20% by mass of glass wool with an average fiber diameter of 0.26 μm (manufactured by Johnman Building), 50% by mass of glass wool with an average fiber diameter of 0.32 μm (manufactured by Johnman Building), an average fiber diameter of 2.70 μm (Johnman Building) 5% by mass of glass chopped fiber (manufactured by Owens Corning Co., Ltd.) of 25% by mass of glass wool with an average fiber diameter of 11 μm and a fiber length of 6 mm is deagglomerated with a pulper at a concentration of 0.5% sulfuric acid pH 2.5 and then with a paper machine Papermaking gave a wet paper. Next, as an adhesion liquid composition, polyacrylic ester 1.85 mass% (trade name: biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), sorbitol polyglycidyl ether 0.0037 mass% (against binder 0.2 mass%) (commodity Name: SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion solution is applied to a wet paper, then dried with a dryer at 130 ° C, and the proportion of the adhesion amount of the adhesion liquid component is 6.06% at a basis weight of 70 g / m ² Filter paper was obtained.

(Example 10)
The composition of the adhesive solution in Example 9 is as follows: 1.85 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.093 mass% of sorbitol polyglycidyl ether to 5 mass% of binder) Name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) In the same manner as in Example 9, a filter paper with a basis weight of 70 g / m ² was used to obtain a filter paper with a ratio of the adhesion amount of the adhesion liquid component of 6.11%.

(Example 11)
In Example 9, the composition of the adhesive liquid is 1.85 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.185 mass% of sorbitol polyglycidyl ether (relative to 10 mass% of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.25% was obtained in the same manner as in Example 9 except for using trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 12)
In Example 9, the composition of the adhesive liquid is 1.85 mass% of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.093 mass% of sorbitol polyglycidyl ether (5 mass% of binder) A filter paper with a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.14% was obtained in the same manner as in Example 9 except that trade name: CR-5L, manufactured by DIC Corporation).

(Example 13)
63% by mass of glass wool with an average fiber diameter of 0.65 μm (made by John Manville), 32% by mass of glass wool with an average fiber diameter of 2.70 μm (made by John Manville), a glass chopped fiber with an average fiber diameter of 11 μm and a fiber length of 6 mm 5% by mass (manufactured by Owens Corning Co., Ltd.) was deagglomerated with a pulper at a concentration of 0.5% and sulfuric acid acidity pH 2.5, followed by paper making with a paper machine to obtain a wet paper. Subsequently, polyacrylic acid ester 1.85 mass% (brand name: Binibran 2680, Nisshin Chemical Industry Co., Ltd. make), sorbitol polyglycidyl ether 0.056 mass% (against binder 3 mass%) (brand name :) as adhesion liquid composition. SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion solution is applied to a wet paper, then dried with a dryer at 130 ° C., and the basis weight 70 g / m ² of filter paper with a ratio of adhesion amount of adhesion liquid component of 6.26% I got

(Example 14)
The composition of the adhesive liquid in Example 1 was 3.95% by mass of polyacrylic ester (trade name: Biniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.119% by mass of sorbitol polyglycidyl ether (3% by mass of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 12.3% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 15)
The composition of the adhesive liquid in Example 1 is as follows: 1.85 mass% of epoxy resin (trade name: Epiclon 850, manufactured by DIC), 0.093 mass% of sorbitol polyglycidyl ether (5 mass% to binder) (trade name: SR-) A filter paper with a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 6.00% was obtained in the same manner as in Example 1 except that SEP was manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 16)
The composition of the adhesive solution in Example 1 is 0.62% by mass of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.031% by mass of sorbitol polyglycidyl ether (relative to 5% by mass of binder) A filter paper having a basis weight of 70 g / m ² and a ratio of an adhesion amount of an adhesion liquid component of 2.11% was obtained in the same manner as in Example 1 except that trade name: SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

(Example 17)
63% by mass of glass wool with an average fiber diameter of 0.50 μm (made by John Manville), 37 mass% of glass wool with an average fiber diameter of 2.70 μm (made by John Manville) at a concentration of 0.5%, sulfuric acid pH 2.5 The mixture was disintegrated with a pulper and then made into paper by a paper machine to obtain wet paper. Next, as an adhesion liquid composition, polyacrylic ester 1.85 mass% (trade name: Binibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), sorbitol polyglycidyl ether 0.056 mass% (against binder 3.0 mass%) (commodity Name: SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion solution is applied to a wet paper, then dried with a dryer at 130 ° C, and the ratio of the adhesion amount of the adhesion liquid component is 6.03% at a basis weight of 70 g / m ² Filter paper was obtained.

(Example 18)
100% by mass of a glass chopped fiber (manufactured by Owens Corning Co., Ltd.) having an average fiber diameter of 11 μm and a fiber length of 6 mm is deaggregated with a pulper at a concentration of 0.5% and sulfuric acid acidity pH 2.5, I got Next, as an adhesion liquid composition, polyacrylic ester 1.85 mass% (trade name: Binibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), sorbitol polyglycidyl ether 0.056 mass% (against binder 3.0 mass%) (commodity Name: SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion solution is applied to a wet paper, then dried with a dryer at 130 ° C, and the ratio of the adhesion amount of the adhesion liquid component is 7.07% at 70 g / m ² of fabric weight Filter paper was obtained.

(Example 19)
63% by mass of glass wool with an average fiber diameter of 0.50 μm (manufactured by Johnmanville), 32% by mass of glass wool with an average fiber diameter of 2.70 μm (manufactured by Johnman Building), 11 μm in average fiber diameter, 6 μm in fiber length 5% by mass (manufactured by Owens Corning Co., Ltd.) was deagglomerated with a pulper at a concentration of 0.5% and sulfuric acid acidity pH 2.5, followed by paper making with a paper machine to obtain a wet paper. Then, an adhesion liquid of 1.85% by mass of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.) as an adhesion liquid composition is applied to a wet paper, and then 0.056% by mass of sorbitol polyglycidyl ether An adhesion solution of (3.0 mass% to binder) (trade name: SR-SEP, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) is applied to a wet paper and then dried with a dryer at 130 ° C. to adhere at a basis weight of 70 g / m ² The ratio of the adhesion amount of a liquid component obtained the filter paper of 6.12%.

Example 20
63% by mass of glass wool with an average fiber diameter of 0.50 μm (manufactured by Johnmanville), 32% by mass of glass wool with an average fiber diameter of 2.70 μm (manufactured by Johnman Building), 11 μm in average fiber diameter, 6 μm in fiber length 5% by mass (manufactured by Owens Corning Co., Ltd.) is deaggregated with a pulper at a concentration of 0.5% and sulfuric acid pH 2.5 with a pulper, and then made into a wet paper by a paper machine, and the wet paper is a dryer at 130 ° C. And dried to obtain a dry paper. Next, as an adhesion liquid composition, polyacrylic ester 1.85 mass% (trade name: Binibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), sorbitol polyglycidyl ether 0.056 mass% (against binder 3.0 mass%) (commodity Name: SR-SEP (Sakamoto Yakuhin Kogyo Co., Ltd.) adhesion solution is applied to dry paper and then dried with a dryer at 130 ° C, and the ratio of the adhesion amount of the adhesion liquid component is 6.08 at a basis weight of 70 g / m ² % Filter paper was obtained.

(Comparative example 1)
63% by mass of glass wool with an average fiber diameter of 0.50 μm (manufactured by Johnmanville), 32% by mass of glass wool with an average fiber diameter of 2.70 μm (manufactured by Johnman Building), 11 μm in average fiber diameter, 6 μm in fiber length 5% by mass (manufactured by Owens Corning Co., Ltd.) was deagglomerated with a pulper at a concentration of 0.5% and sulfuric acid acidity pH 2.5, followed by paper making with a paper machine to obtain a wet paper. Then, an adhesion liquid made of only 1.85% by mass of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.) as an adhesion liquid composition is applied to a wet paper, and then dried with a dryer at 130 ° C. The ratio of the adhesion amount of adhesion liquid component obtained the filter paper of 6.20% at 70 g / m < ² >.

(Comparative example 2)
The composition of the adhesive liquid in Comparative Example 1 is 1.85 mass% of polyacrylic ester (trade name: Viniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.), 0.11 mass% of fluorine-based water repellent (relative to 6 mass% of binder) A filter paper with a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 5.94% was obtained in the same manner as in Comparative Example 1 except that (trade name: Asahi Guard AG-E061, manufactured by Asahi Glass Co., Ltd.).

(Comparative example 3)
The coating weight was 70 g / m ² in the same manner as in Example 9 except that the adhesive liquid composition in Example 9 was changed to only 1.85% by mass of polyacrylic ester (trade name: Viniblanc 2680, manufactured by Nisshin Chemical Industry Co., Ltd.). The ratio of the adhesion amount of the adhesion liquid component obtained the filter paper of 6.06%.

(Comparative example 4)
The coating weight was 70 g / m ² in the same manner as in Example 13 except that the adhesive liquid composition in Example 13 was changed to only 1.85% by mass of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.). A filter paper with a ratio of the adhesion amount of the adhesion liquid component of 6.19% was obtained.

(Comparative example 5)
Example 1 and Example 1 except that the adhesion liquid composition is 0.056% by mass of sorbitol polyglycidyl ether (relative to base material 0.30% by mass) (trade name: SR-SEP, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) Similarly, a filter paper having a basis weight of 70 g / m ² and a ratio of the adhesion amount of the adhesion liquid component of 0.30% was obtained.

(Comparative example 6)
The coating weight was 70 g / m ² in the same manner as in Example 18 except that the adhesive liquid composition in Example 18 was changed to only 1.85% by mass of polyacrylic ester (trade name: Vinibran 2680, manufactured by Nisshin Chemical Industry Co., Ltd.). A filter paper with a ratio of adhesion amount of adhesion liquid component of 7.03% was obtained.

  The evaluation of the filter media obtained in Examples and Comparative Examples was carried out using the following method.

The pressure drop was measured on a filter medium having an effective area of 100 cm ² using a manometer as a differential pressure when air passes at a surface air velocity of 5.3 cm / sec.

The 0.10-0.15 μm transmittance is the number of upstream and downstream PAO particles when air containing PAO particles generated by the Raskin nozzle passes at a surface velocity of 5.3 cm / sec in a filter medium having an effective area of 100 cm ² Was measured using a laser particle counter (KC-18, manufactured by Rion Co., Ltd.), and calculated from the number value. The target particle diameter is 0.10 to 0.15 μm.

For slurry filtration efficiency, use a test solution with a concentration of 100 ppm in which test particles (polishing powder GC # 30000, manufactured by Niigata Seiki Co., Ltd.) are dispersed in ion exchange water, and fix a filter medium with an effective area of 17.3 cm ² to the filter holder. The test solution was attached to a suction bottle, and the turbidity of the test solution before and after suction filtration was measured using a turbidity measuring device COH400 (manufactured by Nippon Denshoku Kogyo Co., Ltd.). The slurry filtration efficiency was calculated from the following equation (Equation 1).
(Equation 1) Slurry filtration efficiency [%] = filtrate turbidity [%] / test liquid turbidity [%] x 100
In Example 7 and Comparative Example 2, a water repellent is blended. The slurry filtration efficiency was not measured because only the filter paper for air filter was targeted for imparting water repellency.

  The tensile strength is a universal testing machine (Autograph AGS-X, manufactured by Shimadzu Corporation) in accordance with JIS P 8113: 2006 "Paper and paperboard-Test method of tensile properties-Part 2: Low speed elongation method". It measured using. The longitudinal direction of the filter paper is the flow direction of the paper machine, and the transverse direction is the direction perpendicular to the flow direction.

  Tables 1 and 2 show the measurement results of the above tests.

  As shown in Examples 1 to 6, the filter paper obtained by adding sorbitol polyglycidyl ether to the organic binder of the present invention has air compared with Comparative Example 1 despite the fact that the pressure loss showing the filtration resistance of the filter paper is equal. The 0.10-0.15 μm transmittance, which indicates the performance as a filter, is small, and the slurry filtration efficiency, which is also a performance as a liquid filter, is large. It can be seen that the performance as filter paper is improved.

  Similarly, in Examples 9 to 12 and Example 13 with different pressure loss, as compared with Comparative Example 3 and Comparative Example 4, the effect on the 0.10 to 0.15 μm permeability and the slurry filtration efficiency is observed. It is understood that the performance as filter paper is improved, and it is understood that the higher the pressure loss, the higher the improvement effect.

  Example 7 is an example in which a water repellent is used in combination on the premise of application as an air filter, but the transmittance of 0.10 to 0.15 μm is smaller than that of Comparative Example 2, and the performance as filter paper is improved. I understand that I am doing.

  Example 2, Example 8, Example 14 and Example 16 are the examples which saw the influence of the ratio of the adhesion amount of an organic type binder. The effect of applying sorbitol polyglycidyl ether to the organic binder of the present invention is seen in the permeability of 0.10 to 0.15 μm and the slurry filtration efficiency until the ratio of the adhesion amount of the organic binder is about 10%. It can be understood that when the ratio of the adhesion amount of the organic binder is increased to about%, an effect corresponding to the adhesion amount can not be obtained.

  Example 15 is an example using an epoxy resin as an organic binder. The same performance as in Example 3 using a polyacrylate was obtained.

  Example 17 is an example which blended only glass wool as glass fiber, and did not blend glass chopped fiber. The same performance as in Example 3 in which glass chopped fibers were blended was obtained. Example 18 is an example where only glass chopped fiber was blended without blending only glass wool as glass fiber. As compared with Comparative Example 6, the effect on the 0.10 to 0.15 μm transmittance and the slurry filtration efficiency can be seen, and it can be seen that the performance as a filter paper is improved.

  Example 19 is an example in which the adhesion liquid containing a polyacrylic acid ester and the adhesion liquid containing sorbitol polyglycidyl ether were separately applied to wet paper. As compared with Example 2 in which the adhesion liquid containing both polyacrylic ester and sorbitol polyglycidyl ether was used, the case where the mixed solution of these agents was attached and the case where they were separately attached without being mixed So we could confirm that the effect is exactly the same.

Example 20 is an example in which the adhesion liquid is applied after the wet paper has been made into a dry paper. It can be seen that the effect on the 0.10-0.15 [mu] m transmittance and the slurry filtration efficiency is not very large as compared with Example 2 in which the adhesion liquid is applied to the wet paper.

Claims (12)

In filter paper made mainly of glass fiber,
In the glass fiber, (1) organic binder and sorbitol polyglycidyl ether, (2) organic binder, sorbitol polyglycidyl ether and crosslinked products thereof, or (3) crosslinking of organic binder and sorbitol polyglycidyl ether Filter paper for filter characterized in that the body is attached.   The filter paper according to claim 1, wherein the pressure drop is 500 Pa or more.   The filter paper according to claim 1 or 2, wherein a water repellent agent is attached to the glass fiber. The organic binder is an epoxy resin, a styrene - butadiene resin, vinyl acetate resin, ethylene - vinyl acetate resins, polyolefin resins, any one of claims 1 to 3, wherein the polyvinyl alcohol or a urethane resin Filter paper described in 1). In a method of producing filter paper mainly composed of glass fiber,
Wet-papering a slurry in which filter medium-constituting fibers including the glass fibers are dispersed to obtain a wet paper;
Attaching an organic binder and sorbitol polyglycidyl ether simultaneously or separately to the wet paper obtained by wet papermaking;
Drying the wet paper on which the organic binder and sorbitol polyglycidyl ether are attached;
A method of producing filter paper for a filter, comprising: The process for drying the wet paper on which the organic binder and the sorbitol polyglycidyl ether are adhered, the organic binder and the sorbitol polyglycidyl ether are cross-linked, the filter paper for the filter according to claim 5 being manufactured. Method. Wherein before the wet paper is dried, the manufacturing method of the filter paper filter of claim 5 or 6, characterized in that the deposition of the organic binder and sorbitol polyglycidyl ether wet web. Method for producing filter paper filter according to any one of claims 5-7, wherein the ratio of the coating weight of sorbitol polyglycidyl ether with respect to the organic binder is 0.2 to 20 mass%. Ratio of coating weight for said filter media fibers constituting the organic binder on a dry weight, the production of filter paper for filter according to any one of claims 5-8, characterized in that 2-10 wt% Method. The filter paper according to any one of claims 5 to 8 , characterized in that a water repellent is further adhered to the wet paper obtained by wet papermaking in addition to the organic binder and the sorbitol polyglycidyl ether. Manufacturing method. The organic binder, the proportion of adhesion amount with respect to the filter media fibers constituting the sum of sorbitol polyglycidyl ether and the water repellent, by dry weight, according to claim 10, characterized in that 2-10 wt% Method of manufacturing filter paper for filter. The organic binder is an epoxy resin, a styrene - butadiene resin, vinyl acetate resin, ethylene - vinyl acetate resins, polyolefin resins, claims 5 to 11, characterized in that a latex or solution of polyvinyl alcohol or a urethane resin The manufacturing method of the filter paper for filters as described in any one of these.