JPS6317873B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water repellent. Specifically, the present invention relates to a water repellent that dries at room temperature or a relatively low temperature and imparts water repellency to building materials such as concrete, mortar, various architectural boards, and base materials such as fiber cloth and paper. In the present invention, the water repellent is a water repellent that imparts hydrophobicity to the surface of the base material by incorporating it into the base material during manufacture of the base material or by forming a film on the surface of the base material. It is a substance that prevents water leakage, etc. Therefore, whether the water repellency is good or bad can be measured by the magnitude of the water absorption rate of the base material when a water absorption test is performed on the water repellent treated base material. [Prior Art and Problems] Conventionally, paraffin wax, silicon compounds, petroleum resins, oils and fats, asphalt, fluororesins, etc. have been generally used as water repellency imparting agents. However, when such water repellents are used to treat wood fiber boards, etc., the amount added must be increased in order to impart sufficient water repellency, which reduces the strength of the base material. There are drawbacks such as: In addition, when using such water repellent agents on fibers, paper, etc., it is necessary to perform high-temperature treatment, and as a result, the paper, fibers, etc. are likely to change texture, reduce whiteness, and yellow. Since this tends to cause trouble, water repellent finishing requires a treatment agent that can be sufficiently effective at low temperatures. In addition, there are other problems such as the limited range of use of colored water repellents even if they are inexpensive, so the development of colorless water repellents that are inexpensive and easy to use is strongly desired in the industry. There is. Additionally, if the surfactant in the water repellent agent used for treatment remains on paper, fibers, etc. treated in this way, it will work against the water repellent effect and may not produce the expected effect. It may not be possible. In view of this current situation, we are conducting intensive research to develop a water repellent that is cheaper than silicon, fluorine compounds, etc., does not impair sufficient water repellency, is white, and can be used in internal addition methods such as paper making. We proceeded to propose a water repellent containing paraffin emulsion as an active ingredient, which not only has excellent water repellency but also solves the above-mentioned problems. (Unexamined Japanese Patent Publication No. 51-116188,
51-115533) However, the water repellent does not develop sufficient water repellency unless it is dried at a certain temperature.
It was difficult to use in applications that required drying at room temperature. [Means for solving the problem] In view of this point, the present inventors conducted further research and found that if a water repellent containing a specific paraffin emulsion as an active ingredient is used, the water repellent can be cleaned simply by drying at room temperature. The present invention was achieved by discovering that a high degree of water repellency can be imparted to materials. That is, the gist of the present invention is that the melting point is 40
A paraffinic hydrocarbon at ~80°C and an oxidized paraffin with an acid value of 10 to 70 that is 0.03 to 1.0 times the weight of the above hydrocarbon, a glycerin monofatty acid ester consisting of glycerin and a fatty acid having 10 to 18 carbon atoms, and a nonionic emulsifier. It is a water repellent consisting of a paraffin emulsion that is emulsified in water in the presence of. To explain the present invention in detail below, the paraffinic hydrocarbon used as a raw material for the paraffin emulsion, which is the active ingredient of the water repellent of the present invention, must have a melting point in the range of 40 to 80°C. If the melting point is lower than 40℃, the quality will deteriorate in summer, and if it is higher than 80℃, it will not show sufficient water repellency.Also, the acid value of paraffin oxide is in the range of 10 to 70, especially 20 to 40. Furthermore, it is preferable that the melting point be in the range of 30 to 90°C, particularly 40 to 80°C. If the acid value is below the above range, it will be difficult to emulsify with a small amount of emulsifier, and the resulting paraffin emulsion will have poor emulsion stability.If the oxidation is above the above range, it will be difficult to impart water repellency to the paraffin emulsion. Both are unfavorable as they reduce effectiveness. The reason why paraffin oxide having the above melting point is preferable is due to the same reason as the above paraffinic hydrocarbon. And paraffin oxide is 0.03 to 1.0 relative to paraffinic hydrocarbons.
It is used in an amount of 0.05 to 0.45 times by weight, preferably 0.05 to 0.45 times by weight. If oxidized paraffin is used in an amount greater or less than the above range, no effective water repellent effect can be expected. The glycerin monofatty acid ester to be present when emulsifying the paraffinic hydrocarbon and oxidized paraffin in water includes glycerin and a fatty acid having 10 to 18 carbon atoms such as palmitic acid, stearic acid, oleic acid, lauric acid, and capric acid. Monoesters formed are mentioned. Such monoesters may contain diesters, triesters or mixtures thereof. Further, the above fatty acid monoesters may be used in the form of a mixture, such as a mixture of linoleic acid monoglyceride and oleic acid monoglyceride. Nonionic emulsifiers used for emulsification with paraffin hydrocarbons, oxidized paraffin, and glycerin monofatty acid esters include ethylene oxide adducts of fatty acid monoglycerides, ethylene oxide adducts of sorbitan, ethylene oxide adducts of higher alcohols such as oleyl alcohol, Examples include ethylene oxide adducts of alkylphenols and ethylene oxide adducts of polypropylene glycol. The mixing ratio of the glycerin monofatty acid ester and the nonionic emulsifier can be set arbitrarily. The total amount of glycerin monofatty acid ester and nonionic emulsifier is usually 1 to 20% by weight, preferably 1 to 10% by weight, based on the total of paraffin hydrocarbon and oxidized paraffin (hereinafter both are collectively referred to as total paraffin). used. Such a paraffin emulsion can be produced by emulsifying total paraffin melted under heating with water by vigorous stirring in the presence of a glycerin monofatty acid ester and a nonionic emulsifier, or by emulsifying total paraffin melted under heating using a conventional method. It can be produced by adding water dropwise to the mixture under strong stirring in the presence of a glycerin monofatty acid ester and a nonionic emulsifier to effect phase inversion emulsification. For emulsification, various devices are used, such as a homomixer, a bulb homogenizer, a colloid mill, and an ultrasonic emulsifier. Also, water is usually used in an amount of 0.5 to 10% by weight based on the total paraffin. A water-soluble alkali metal compound or ammonium hydroxide may be present for the purpose of neutralizing paraffin oxide during emulsification. Examples of the alkali metal compound include alkali metal hydroxides such as lithium hydroxide, potassium hydroxide, and sodium hydroxide; alkali metal carbonates such as lithium carbonate and sodium carbonate; and sodium hydride. It is particularly preferable to have these compounds present during emulsification when it is difficult to obtain a stable paraffin emulsion that can serve as an active ingredient in the water repellent of the present invention, or in cases such as the above-mentioned phase inversion emulsification. Of course, these compounds may be added at the stage where an unstable or temporary emulsion has been formed. These compounds are normally used in amounts up to three times the amount required to neutralize 100% of the acid value of oxidized paraffin. Furthermore, in order to improve the storage stability of the paraffin emulsion, water-soluble polymer compounds, such as synthetic polymer compounds such as polyvinyl alcohol, polyacrylamide, and polyacrylic acid, and cellulose derivatives such as methyl cellulose, carboxymethyl cellulose, and hydroxyethyl cellulose, It is also possible to use starch derivatives such as carboxymethyl starch, hydroxyethyl starch and the like. The timing of adding these water-soluble polymer compounds is not particularly limited, but in order to uniformly disperse them in the paraffin emulsion, it is particularly preferable to add them before the end of emulsification. The amount used is 0.01 to 10 in addition to paraffin emulsion.
% by weight, especially from 0.01 to 6% by weight. Furthermore, it is also possible to mix and use various polymer emulsions, such as acrylic ester and vinyl ester polymer emulsions, as water repellent aids with the paraffin emulsion. Further, other additives may be added as necessary. When bringing the water repellent made of such a paraffin emulsion into contact with the base material, it is preferable to include an alkaline earth metal compound in order to further improve water repellency when dried at room temperature. In particular, when the base material does not contain the compound, it is particularly preferable that the alkaline earth metal compound be present in the water repellent. If the base material itself contains the compound, such as cement or calcium silicate, it can be used instead. Examples of the alkaline earth metal compound include alkaline salts such as alkaline earth metal hydroxides and carbonates. More specific examples include calcium hydroxide, barium hydroxide, magnesium hydroxide, calcium carbonate, and magnesium carbonate. When using an alkaline earth metal compound, it is preferable to use it immediately before bringing the water repellent into contact with the substrate. That is, it is preferable to use as a water repellent a paraffin emulsion in which these compounds are added immediately before contact. Of course, when the base material is treated as a slurry containing the base material, it may be added to this slurry. The amount of alkaline earth metal compound used is generally in the range of 1 to 100% by weight, particularly 10 to 80% by weight, based on the solid content in the paraffin emulsion. The solid content in the paraffin emulsion refers to the solid content remaining after the paraffin emulsion is heated in a conventional manner to remove water and other volatile matter. Various well-known substrates can be used as base materials that impart water repellency, and specific examples include products such as concrete, mortar, and cement, mineral fiber boards, calcium silicate boards, magnesium carbonate boards, and ettringite boards. , wood fiberboard, wood chip board, fiber cloth, paper, etc. The water repellent of the present invention is particularly effective against the first five types of substrates. As a method for bringing the base material into contact with the paraffin emulsion type water repellent, any known water repellent finishing method can be employed, and is appropriately selected depending on the type of the base material or its use. For example, a method of kneading a base material and a water repellent, a method of adding a water repellent to a slurry containing a base material, a method of immersing a base material in a water repellent,
A method such as spraying or coating a water repellent on the base material is adopted. For building materials such as concrete, mortar, and cement, the first two methods are often used, and for textiles, paper, etc., the latter two methods are often used. [Effects of the Invention] The water repellent of the present invention has been explained in detail above,
If the water repellent of the present invention is used, a high degree of water repellency can be imparted to the substrate simply by bringing the substrate into contact with the water repellent and then drying at room temperature or at a relatively low temperature. As can be seen in the examples below, when the water repellent of the present invention is used on an asbestos calcium silicate board or a magnesium carbonate board, the water absorption rate is as follows:
In addition, the water repellency is about half or less compared to when using a water repellent that does not contain glycerin monofatty acid ester. [Examples] The present invention will be explained in more detail by Examples below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In addition, in the following, "parts" and "%" indicate "parts by weight" and "% by weight", respectively. [Manufacture of paraffin emulsion] Example 1 90 parts paraffinic hydrocarbon with a melting point of 57.3°C Paraffin oxide with an acid value of 28 and a melting point of 67°C 10 parts Sodium hydroxide 0.2 parts Polyoxyethylene oleyl ether (HL
B. Number = 15) 7.5 parts Stearic acid monoglyceride 2.5 parts Charge the above ingredients in the above ratio into an emulsification container and 80℃
200 parts of deionized water was added dropwise while stirring with a homomixer to effect phase inversion emulsification. Total time required: 30
A paraffin emulsion a having a solid content of 36% was obtained. Example 2 Solid content was determined in the same manner as in Example 1 except that 2.5 parts of sorbitan monostearate was used instead of 2.5 parts of stearic acid glyceride in Example 1.
A 36% paraffin emulsion b was obtained. Example 3 In Example 1, stearic acid monoglyceride
2.5 parts linoleic acid monoglyceride instead of 50
and 50 parts of oleic acid monoglyceride.
A paraffin emulsion c having a solids content of 36% was obtained in exactly the same manner as in Example 1, except that 2.5 parts were used. Example 4 In Example 1, stearic acid monoglyceride
Stearic acid monoglyceride instead of 2.5 parts,
Palmitic acid monoglyceride, myristic acid monoglyceride, stearic acid diglyceride,
Paraffin with a solids content of 36% was prepared in the same manner as in Example 1, except that 2.5 parts of mixed glyceride containing palmitic acid diglyceride and myristic acid diglyceride in the ratio of 56.7:37.2:6.5:4.4:2.8:0.5 was used. Emulsion d was obtained. Example 1 and Comparative Example 1 Paraffin emulsion a 1% solid content
Dilute the diluted solution with water so that the size is 10 cm x
10cm x 0.7cm, asbestos calcium silicate plate with a specific gravity of 0.7 (trade name Hisirax, manufactured by Mitsubishi Mining Cement Co., Ltd.)
After soaking, it was dried at room temperature for 2 days. A water absorption test was conducted on this sample. For water absorption test, sample
The water absorption rate (Aw) was determined after being immersed in water at 20±1°C for a predetermined time. The results are shown in Table 1. In addition, in the following Examples and Comparative Examples, Aw was calculated from the following formula. Aw = Weight of the sample after the water absorption test (g) - Weight of the sample before the water absorption test (g) / Weight of the sample before the water absorption test (g) x 100 In addition, [Aw] _x is the water absorption test for X hours. Therefore, in this example, [Aw] ₂ indicates the water absorption rate when the sample was immersed in water for 2 hours. For comparison, the water absorption rate was measured in the same manner as in Example 1, except that the asbestos calcium silicate plate was immersed in water not containing paraffin emulsion a. The results are also listed in Table 1. Comparative Example 2 Water absorption was measured in exactly the same manner as in Example 1 except that paraffin emulsion b was used instead of paraffin emulsion a in example 1, and the results are shown in Table 1. Example 2 and Comparative Example 3 Paraffin emulsion a was added to 520 parts of Portland cement (containing calcium as an alkaline earth metal), 1040 parts of Toyoura standard sand, and 286.6 parts of water to give a solid content of 1.5% to the mortar. 80.3 parts of emulsion a was added, kneaded with a mortar mixer, and poured into a predetermined mold to obtain a molded product with dimensions of 4 cm x 4 cm x 16 cm. This is JIS
It was cured for 19 days in a humidity box at 20±3℃ and a humidity of 80% or more according to A1404. Furthermore, this was dried at room temperature until it reached a constant temperature, and a specimen with a specific gravity of 2.2 was prepared.
This was immersed in water (20°C ± 3°C) for a predetermined time in a constant temperature chamber at 20°C ± 3°C and humidity of 80% or more, and the water absorption rate was measured. The results obtained in this manner are shown in Table 1. For comparison, the water absorption rate was measured in the same manner for a sample without paraffin emulsion a, and the results are shown in Table 1. Example 3 and Comparative Example 4 Paraffin emulsion a was added as a solid content to a 9% water slurry of neutral magnesium carbonate (first grade reagent), and asbestos was added to the neutral magnesium carbonate at a concentration of 1%.
18% magnesium hydroxide and 18% magnesium hydroxide were mixed and dispersed, pressure molded using a water press, and then heated at 50℃ for 24 hours.
After drying, dimensions 10cm x 10cm x 0.9cm, specific gravity 0.66
A molded body was obtained. This was immersed in water at 20°C±3°C and the water absorption rate was measured. The results obtained in this manner are shown in Table 1. For comparison, the water absorption rate was measured in the same manner for a sample without paraffin emulsion a, and the results are shown in Table 1. Example 4 and Comparative Example 5 100 parts of high water slag, 6 parts of dihydrate gypsum, and 20 parts of slaked lime were stirred with 1200 parts of water at 90° C. for 5 hours, and the resulting slurry was cooled. Bulb and paraffin emulsion a were added and dispersed in an amount of about 1.5% as a solid content based on the solid content in the produced slurry, and after filtration, the slurry was molded under pressure at 100 kg/cm ² . Furthermore, after curing at room temperature for 28 days, it was dried at room temperature to obtain an ettringite plate with a specific gravity of 0.9 and dimensions of 10 cm x 10 cm x 0.9 cm. This sample was immersed in water at 20°C±3°C and the water absorption rate was measured. The results are shown in Table 1. For comparison, paraffin emulsion a
The water absorption rate was measured in the same manner for the sample without using , and the results are shown in Table 1. Example 4 and Comparative Example 5 Commercially available ordinary plywood (JAS grade, thickness 9 mm, specific gravity
0.7, 5 layers) was immersed in a calcium hydroxide supernatant, and then immersed in a diluted solution of paraffin emulsion a with water to a solid content of 1% for 10 minutes, and then incubated at 45°C for 24 hours. Dry for an hour. This sample
The water absorption rate was measured by immersing the sample in water at 20°C±3°C, and the results are shown in Table 1. For comparison, the water absorption rate was measured in the same manner for those without paraffin emulsion a, and the results are shown in Table 1. Example 5 The same procedure as in Example 1 was carried out except that paraffin emulsion d was used instead of paraffin emulsion a. The results obtained are shown in Table 1. Example 6 The same procedure as in Example 1 was carried out except that paraffin emulsion d was used instead of paraffin emulsion a. The results obtained are shown in Table 1. 【table】

Claims (1)

[Claims] 1. A paraffinic hydrocarbon with a melting point of 40 to 80°C and an acid value of 10 to 1.0 times the weight of the hydrocarbon.
70 oxidized paraffin, glycerin and carbon number 10~
A water repellent consisting of a paraffin emulsion made by emulsifying glycerin monofatty acid ester consisting of 18 fatty acids in water in the presence of a nonionic emulsifier. 2. The water repellent according to claim 1, wherein the total amount of glycerin monofatty acid ester and nonionic emulsifier is 1 to 20% by weight based on the total amount of paraffin hydrocarbon and oxidized paraffin. 3. The water repellent according to claim 1, which is obtained by emulsifying a paraffin emulsion in the presence of a water-soluble alkaline alkali metal compound or ammonium hydroxide.