JPH0749625B2 - Method for producing fixed silica fiber material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention uses ultrafine silica (silicon dioxide) obtained by hydrolyzing and polycondensing ethyl orthosilicate in the presence of a reactive emulsifier on a fiber material. The present invention relates to a method for manufacturing a material fixed to the.

(Problems to be solved by conventional technologies and inventions) Generally, such as baking coatings on steel cabinets, electric appliances, refrigerators, sinks, etc., plastic products such as bathtubs, washbasins, etc. Gum-like or resin-like stubborn stains such as oxides cannot be removed by simply wiping them with a cloth or paper, and cannot be removed with a detergent, so it is necessary to scrape them off with a cleaner such as polishing powder, but the surface may be scratched. There is. Also, to remove rust and scales from metal surfaces such as nickel-plated water taps, stainless steel products, brass, silver, tin, etc., scrape off with a cloth or other specialized cleaner such as a paste or liquid metal polisher. It is cumbersome, and it lacks convenience because it has an oily substance such as a paste on the hand, a bad odor of the solvent, and a troublesome removal action of the abrasive.

In addition, the paste and liquid cleaner products that have been conventionally used to remove dirt and rust are made into fine particles of abrasives by mechanical crushing using a colloid mill, etc. Precautions were required in use.

(Means for Solving the Problems) The present inventor has hydrolyzed and polycondensed water with a metal alkoxide such as ethyl orthosilicate in a medium such as ethanol in the production of glass or ceramic thin film at 60 to 80 ° C. We are studying the application technology of the sol-gel method in which a sol consisting of oxides or oxide fine particles is formed, a thin film is formed at the gelation point, and then heated to several hundred degrees to form a glass or ceramic thin film. Was originally researching the improvement,
When ethyl orthosilicate (tetraethoxysilane), which is an oily substance that is completely immiscible with water, is emulsified with a reactive emulsifier having a polymerizable functional group, alcohols such as ethanol, which are common media at room temperature, are removed. It was found that hydrolysis was accelerated without addition and the system turned into a completely homogeneous and transparent aqueous sol. Then, it was found that a sheet material suitable for removing stains such as rust and stubborn oil stains having a relatively rigid material feel can be obtained by impregnating this aqueous gel into a fiber material and then drying it. Based on this, the present invention has been completed.

That is, the present invention is a method for producing a fiber material, which comprises hydrolyzing ethyl ortho-based acid in the presence of a reactive emulsifier, impregnating a fiber material with a transparent aqueous silica sol obtained by polycondensation, and then drying, Is provided.

In the present invention, the well-known sol-gel method is used as a method for producing ultrafine particle silica that is firmly fixed to the fiber, but conventionally, in the sol-gel method, ethyl orthosilicate is not mixed with water at all, so that it is used as a common medium. Although a large amount of ethanol was added and hydrolysis / polycondensation was performed over a long period of time at a temperature of 60 to 80 ° C, it is not economical to use alcohols, and hydrolysis reaction occurs under alcohol reflux. There was a drawback that was suppressed. In the sol-gel method, hydrolysis and condensation reactions proceed at the same time to finally produce silica. However, the reaction involves hydrolysis and two-molecule condensation, as well as two-dimensional and three-dimensional polycondensation as shown in the following formula. Eventually, the three-dimensional siloxane bond increases and the spherical shape becomes spherical due to the complicated reaction that occurs, and if the silanol SiOH remaining on the surface is ignored, the net reaction is given by the following equation, and the ultrafine silica particles (Si
Generates a large amount of O ₂ ).

(Hydrolysis) Si (OC ₂ H ₅ ) ₄ + 4H ₂ O → Si (OH) ₄ + 4C ₂ H ₅ OH (2 molecule condensation) (Polymer produced by polycondensation) The addition amount of water needs to be more than the stoichiometric amount, but the addition amount can be arbitrarily selected widely and the concentration can be adjusted according to the purpose of the aqueous silica sol. Preferably, the amount of ethyl orthosilicate is the same amount (100%) by weight, but up to 9 times amount (900%). If the amount of water is too large, it takes a long time until a transparent sol is formed, and if a large amount of water is stirred, the efficiency becomes poor. After forming a thick sol, it can be arbitrarily diluted with water, and increasing the amount of water is meaningless. On the other hand, if the amount is too small, the emulsion initially emulsified in white is unlikely to be a uniform transparent sol, and it is easy to form bead-shaped gel particles or a semitransparent viscous sol.

The sol produced is generally a transparent, uniform, low-viscosity sol and contains ethanol produced by the hydrolysis of ethyl orthosilicate, so it rapidly increases when it is sprayed or impregnated into a fibrous material such as non-woven fabric or tissue paper. It gives a fibrous material (sheet material) that dries and is rather rigid. In addition, the generated sol has good wettability because the reactive silanol groups remain on the surface of the silica particles as shown in the above reaction formula due to the polycondensation of ethyl orthosilicate, and also with the fibrous material due to hydrogen bonding and the like. They are firmly bonded and the silica particles are never detached. There is no particular limitation on the amount of the silica particles fixed to the fiber material and fixed to the fiber material, but in the case of a sheet such as paper, the dry weight of silica in the sol for impregnation is preferably 5% by weight or more. The silica particles generated here are generated by a chemical reaction.
It is a very fine silica particle with a particle size of 50 nm, which is close to the molecular level and has a uniform particle size, so that it has the characteristic that it can remove only dirt without damaging the substrate.

The reactive emulsifier used in the present invention is a macromonomer having a polymerizable functional group such as metaacryloyl group and vinyl group at one or both terminals of one molecule, and ethylene oxide group is hydrophilic group and propylene oxide group is hydrophobic group. It is an amphipathic emulsifier that emulsifies water-insoluble ethyl orthosilicate and accelerates hydrolysis, and the reactive emulsifier eventually polymerizes to attach silica particles to fibers such as paper. It is effective, and since it is an amphipathic surface-active substance, it also has the effect of lowering the interfacial tension, has wettability with water and oil, and contributes to stain removal. The amount of reactive emulsifier used is 0.
It is preferable to use about 5 to 10% by weight. If this amount is too small, the emulsification may be insufficient, the hydrolysis may be delayed, the binder effect may be reduced, and the silica particles may be desorbed.
When a reactive emulsifier is present and has a high concentration, it promotes the emulsion cleaning action of oils and the like, but when wet, it causes bubbles or increases the tackiness, and it is not preferable from the economical viewpoint.

As the reactive emulsifier, various commercially available ones can be used, but New Frontier A-229E capable of keeping the pH of the system on the acidic side.
(Made by Dai-ichi Kogyo Seiyaku Co., Ltd.), Kayamer (made by Nippon Kayaku Co., Ltd.),
Latemur K180 (manufactured by Kao Soap Co., Ltd.), Akron RN-20 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (all of which are trade names) are suitable. Other various anions, nonions, and cationic surfactants can be mixed and used, but it is important to keep the pH of the system on the acidic side, and hydrolysis is slow at neutral,
Further, when the system becomes alkaline, the particle size of the produced silica becomes large, which is not preferable.

The shape of the fiber material used in the present invention is not particularly limited, but a sheet shape (the thickness is not limited) is practically preferable and can be appropriately selected depending on the intended use of the material. In particular, it is suitable for removing rust because a non-woven fabric made of polypropylene having oil absorbency (for example, Kleenex Clean Cloth (trade name), manufactured by Tojo Kimberley Co., Ltd.), towel cloth, and bleached cotton stubbornly removes stains. In addition, JK wiper (product name, which is widely used in various work and research and experiment
Jujo Kimberley Co., Ltd.) and Kimwipe (trade name, manufactured by Tojo Kimberley Co., Ltd.) absorb moisture and oil, and are inexpensive and suitable as a disposable type because there is no fiber adhesion.

(Effects of the Invention) Since the material obtained by the present invention is obtained by impregnating a non-woven fabric, towel cloth, tissue paper, etc. with ultrafine aqueous silica sol and drying, silica is firmly fixed to the fiber material and is relatively rigid. There is a feeling of frictional material, it can be quickly and easily removed from rust and dirt, and the dirt itself is adsorbed on the fiber surface of non-woven fabric or tissue paper. There is the convenience that the surface can be cleaned.
Therefore, it is suitable as a wiper type stain remover that does not require a cleaning agent or an abrasive. Also, since this material uses the polishing action of extremely fine particles of silica of 50 nm or less generated on fibers of paper, cloth, etc., even if the dirt on the surface of the plastic or coating film is removed by polishing, the base material will not be scratched. It has the characteristics that it can remove dirt without applying it, has moderate friction, and can be removed very easily by simply wiping off dirt, rust, and the like. Not only can it be used favorably for removing stains on metal, enamel, glass, and tile surfaces, but it can also remove stains on the surface of various materials such as plastic, baking coating film, vinyl, film, leather, and wood.

(Example) Next, the present invention will be described in more detail based on examples.

Example 1 Ethyl orthosilicate 1 in a 500 ml Erlenmeyer flask with stopper.
Dissolve 0.3 to 3 g of the reactive emulsifier New Frontea A-229E in 00 g and add 30 ml to 400 ml of water to immediately obtain a white and uniform emulsified state, but if you stir with a magnetic stirrer for 10 to 30 minutes at room temperature, ethanol will be produced. As a result, the transparency of the entire system changed to a uniform sol.

When the formed aqueous sol is impregnated with Kimwipe and then naturally dried, a semitransparent tissue paper containing ultra-fine silica having a slight rigidity is obtained. This water-based sol-impregnated Kimwipe tissue paper gets wet well with water,
Even if it gets wet with water, there is little decrease in strength. If a small amount of water is applied and the stains and discolored parts of the baking coating film of steel cabinets, refrigerators, etc. are rubbed, the stains can be easily removed, and the discolored parts can be restored without impairing the gloss. Moreover, it was confirmed that stains and rust on the nickel plating of water faucets, handles, and various devices can be easily restored to a high-gloss plating by rubbing with a tissue paper. Glass, tile,
Not only stainless steel, but also plastic, leather,
Dirt and rust on vinyl sheets, wood, brass, tin and silver products were also easily removed and not scratched.

Example 2 In the same manner as in Example 1, 1 g of the reactive emulsifier Aqualon RN-20 was dissolved in 100 g of ethyl orthosilicate, 30 to 400 ml of water was added, and 0.1N hydrochloric acid was added dropwise. After adjusting the pH to 3-5,
When the emulsion was stirred at room temperature, the whole system changed to a transparent and uniform sol in about 20 to 40 minutes.

When the formed aqueous sol was impregnated into polypropylene non-woven cloth Kleenex Clean Cloth and then air-dried, a non-woven cloth containing ultrafine particles of silica having a substantially rigid appearance was obtained.

We have found that any stubborn stain can be removed by wetting with a small amount of water and rubbing.

It was acknowledged that the non-woven fabric of the base material was strong even if it was rubbed off quite violently, the stains could be removed comfortably, and that it could be used again and again by washing with water or detergent.

Claims (1)

[Claims] 1. A method for producing a fiber material, comprising impregnating a fiber material with a transparent aqueous silica sol obtained by hydrolyzing and polycondensing ethyl orthosilicate in the presence of a reactive emulsifier, and then drying.