JPS6240053B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an impregnation treatment agent for processing filter materials such as dust masks. Conventionally, the method of processing filter materials such as those for dust masks is to impregnate a material such as wool felt with synthetic resin, squeeze out the excess liquid, and heat it at 100°C.
By heating and drying to a certain degree and processing with resin,
A method of imparting an electrostatic effect to materials was widely adopted. In addition, other methods have been proposed, such as Japanese Patent Publication No. 39-5987 ``Method for Processing Materials for Dust Masks'', which eliminate the drawbacks of the conventional methods. Solution A is obtained by adding appropriate amounts of hydrochloric acid and ammonium chloride as a catalyst to a mixture of para-alkyl phenols and formalin, and heating the solution. A material such as wool felt is immersed in the resin solution obtained by adding an appropriate amount of ammonia water and heating it to prepare the resin B. A material such as wool felt is immersed in the resin solution obtained by adding appropriate amount of benzol and heating the solution A and resin B. It is characterized by this. However, all of the known methods use organic solvents such as benzene as the solvent for the resin, which not only requires a large amount of money for the solvent recovery equipment, but also poses safety and hygiene concerns such as fires and human disasters. Various problems still remained. In contrast, the present inventors previously filed a patent application filed in 1973-
No. 34997 "Method for processing filter materials such as dust masks" etc., after impregnating appropriate materials such as wool or non-woven fabric with resin and drying them by known means, mechanically bending or stretching the materials. Dust can be collected by hand-rubbing, tanning by similar physical means, and using cheaper materials such as non-woven fabrics or other materials with lower ventilation resistance than known methods. We proposed a method that can significantly improve efficiency. The present invention relates to an impregnating treatment agent applied to this prior invention, by emulsifying a resin using water as a solvent and a surfactant.
It has good adhesion and impregnation properties even for materials such as wool, which are difficult to impregnate with resin unless it is an organic solvent-based resin liquid, and does not require expensive solvent recovery equipment as in the above-mentioned known method. Even safer,
To provide an impregnating agent that can produce a dustproof filter with significantly improved dust collection efficiency without any hygienic drawbacks. The resin used in the present invention is an acrylic resin, a styrene resin, or a vinyl acetate resin, either alone or as a mixture. It is a copolymer resin. In addition, the surfactant in the present invention is used as an emulsifying dispersant, and both anionic and nonionic surfactants can be used, but anionic surfactants are particularly effective for acrylic resins and styrene resins, and acetic acid Anionic or nonionic resins are particularly effective for vinyl resins, and anionic resins are particularly effective for acrylic-vinyl acetate copolymer resins. In the present invention, the amount of resin added is 0.3 in terms of the dust collection efficiency of the dustproof filter, as shown in the reference example below.
It is important that the amount of surfactant be ~2% by weight, and the amount of surfactant added should be 1/10 of the amount of resin added. In addition, in the present invention, curing accelerators such as iron naphthenate, manganese naphthenate, cobalt naphthenate, zinc naphthenate, chromic acid, alkali chromate, dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, etc. , plasticizers such as phthalic acid esters such as dihebutyl phthalate and dioctyl phthalate, and phthalic acid mixed group esters such as butyl benzyl and butyl lauryl. By adding these curing accelerators, plasticizers, etc., effects such as shortening the curing time after being impregnated with the impregnating treatment agent of the present invention and improving the condition of the resin film after curing and drying can be obtained. No adverse effect on dust collection efficiency was observed at all. Furthermore, in the present invention, in order to improve the stability of the emulsified dispersion of the resin, in the case of acrylic resins and styrene resins, a weak alkaline solution with a pH of 7 to 8,
In the case of vinyl acetate resin, it needs to be weakly acidic with a pH of 4 to 5.5. The impregnating treatment agent of the present invention described above can be applied to 1) felt (natural animal fiber), 2) woven fabrics or non-woven fabrics of natural vegetable fibers such as cotton and rayon, and 3) single fibers of synthetic fibers such as polypropylene, polyolefin, nylon, and acrylic. Alternatively, it can be impregnated into various materials such as a combination non-woven fabric, a combination non-woven fabric of the synthetic fibers described in 3 above and natural vegetable fibers described in 2 above, 5 foam molded products such as rubber or urethane, etc., and then rolled or the like. Squeeze out excess liquid, heat and dry at around 100-150℃, and then apply tanning treatment by mechanically bending, stretching, loosening by hand, or similar physical means. This makes it possible to manufacture a dustproof filter with good air permeability and extremely high dust collection efficiency, which is extremely useful industrially. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 2 parts by weight of vinyl acetate resin adjusted to a particle size of 0.5 to 1μ, 0.2 parts by weight of an anionic surfactant (product name: Liporan, manufactured by Lion Oil Co., Ltd.), 0.5 parts by weight of a curing accelerator (cobalt naphthenate), and the remainder When the mixture was well mixed with water and a small amount of acetic acid was added to adjust the pH to 5.5, it eventually turned into an emulsion and took on a milky white appearance. This product was impregnated with felt to a thickness of 3 mm, and the excess liquid was squeezed out using a roll, pre-dried at 50 to 60°C, and further heated and dried in a constant temperature bath at 110°C. Then, a part of it was passed three times through a tanning device with a total of seven rolls of 10 mm diameter installed in a chain at 15 mm intervals (distance from center to center of the rolls).
The other part is used as a dust filter without passing through the tanning equipment, improving the dust collection efficiency of both.
When compared according to the JIS T8151 "dust mask" test method, the former (with tanning treatment) had a dust collection efficiency of 99.8%, while the latter (without tanning treatment) had a dust collection efficiency of 54.5%. . Example 2 Acrylic resin 1.5 with particle size adjusted to 0.1-0.2μ
Add parts by weight, 0.15 parts by weight of an anionic surfactant (trade name: Labelin, manufactured by Dai-ichi Kogyo Yakuhin Co., Ltd.), and 0.3 parts by weight of a curing accelerator (cobalt naphthenate) to 94.7 parts by weight of water, and adjust the pH to 7 with caustic soda. Mix and stir well. This material eventually turned into an emulsion and took on a milky white appearance. This was made into a tanned dustproof filter in the same manner as in Example 1 except that the nonwoven fabric with a thickness of 1.5 mm made of a blend of polypropylene and rayon was used, and the dust collection efficiency was measured in the same manner as in Example 1. After getting used to it, the dust collection efficiency was 99.8% with two layers. Example 3 1 part by weight of an acrylic-styrene copolymer resin whose particle size was adjusted to 0.1 to 0.2μ and 0.1 part by weight of an anionic surfactant (product name: Riporan, manufactured by Lion Oil Co., Ltd.) were added to 98 parts by weight of water, and caustic soda was added. PH at 7.5
After adjusting the temperature, the mixture was thoroughly mixed and stirred to form an emulsion. This product was made into a tanned dustproof filter in the same manner as in Example 1 except that the material was a 3.0 mm thick nonwoven fabric made of a blend of polypropylene and rayon, and the dust collection efficiency was measured in the same manner as in Example 1. After getting used to it, the dust collection efficiency was 99.8% with two layers. Reference Example The following various experiments were conducted to confirm the optimum resin concentration. First, as a result of preliminary tests, homopolymer resins such as acrylic resins, styrene resins, and vinyl acetate resins, or copolymer resins alone or in mixtures, have approximately the same yield at the same concentration, regardless of the type of resin. It has been found that dust efficiency can be obtained. Next, an emulsion solution was prepared in exactly the same manner as in Example 1 except that the vinyl acetate resin used in Example 1 was used and the resin concentration was varied. Using non-woven fabric, each was made into a tanned dustproof filter in the same manner as in Example 1, and the dust collection efficiency was measured in the same manner as in Example 1 with a 3 mm filter and a 1.5 mm filter stacked one on top of the other. The results were as shown in Table 1.

[Table] As is clear from Table 1, the dust collection efficiency is closely related to the resin concentration, and the dust collection efficiency can be obtained according to the resin concentration. To obtain more than %, the resin concentration should be 0.3
It turns out that it is necessary to keep it within the range of ~2% by weight. Moreover, the reason for this is thought to be that the electrostatic effect becomes smaller whether the amount of resin attached is too small or too large.

Claims (1)

[Claims] 1. In an impregnating treatment agent for manufacturing a dust filter by tanning by physical means after impregnating with a synthetic resin, 0.3 to 2% by weight of acrylic resin, styrene resin, or vinyl acetate resin alone or Contains a mixture, and further contains the balance water and a surfactant of 1/10 of the amount of the above resin, and if the above resin is an acrylic resin or a styrene resin, it is slightly alkaline with a pH of 7 to 8, and a vinyl acetate resin. In this case, an impregnating treatment agent for dust filters characterized by having a pH adjusted to a weak acidity of PH4 to 5.5.