JPH013041A - Efflorescence prevention agent for mortar and concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a cement admixture for the purpose of preventing efflorescence from occurring on the surfaces of mortar and concrete. <Prior Art> Whiteness that appears on the surface of hardened cement products such as mortar and concrete is one of the fatal defects of cement. If efflorescence occurs on hardened cement, it not only significantly impairs the appearance of the building, but also has harmful effects on finishing materials such as tiles and paints, such as changes in color tone and the so-called runny nose caused by efflorescence. There is. Therefore, the problem of efflorescence has become an important problem in the construction of plastered mortar walls, tiled walls, interlocking blocks, and colored slabs. Therefore, in order to prevent efflorescence, the following various methods have been proposed. ■A method of adding substances that react with white or other components to cement. ■Method of reducing kneading water by using a water reducer together. ■A method of adding substances that lower the surface tension of water. ■How to form a waterproof layer. <Problems to be Solved by the Invention> However, although all of these methods have some effect on Shirooke Boichi, it has been difficult to find a sufficient effect. In order to solve this problem, the inventors of the present invention have continued intensive research for many years, and as a result, they have completed an efflorescence inhibitor for mortar and zinccrete that has unprecedented effects. A means to solve these problems> The anti-efflorescence agent added to concrete consists of a soluble alkaline earth metal salt, an amino resin or an amino alkyd resin as the main components, and a higher fatty acid salt as an auxiliary component. The problem was solved as follows. Then, add 50 parts by weight of the amino resin or amino alkyd resin to 100 parts by weight of the soluble alkaline earth metal salt.
A more significant effect can be obtained by using ~150 parts by weight of dry worms and 5 to 25 parts by weight of a higher fatty acid salt. As described above, we were able to obtain an unprecedented efflorescence prevention effect, which is thought to be partly due to the waterproofing effect of this efflorescence inhibitor. . This will be explained in more detail below. The soluble alkaline earth metal salt used in the present invention refers to an alkaline earth metal salt that dissolves in water, and may be selected from, for example, calcium chloride, magnesium chloride, calcium oxalate, etc. Among these, particularly Preferred is calcium chloride, which is inexpensive, has high solubility in water, and has a high effect of promoting cement setting. The soluble alkaline earth metal salt is usually used as an aqueous solution having a concentration of 30 parts by weight or more. The amino resin used in the present invention may be selected from, for example, urea resins, melamine resins, or amino alkyd resins that are a mixture of these amino resins and alkyd resins, but room temperature curing amino alkyd resins are particularly preferred. preferable. Note that there is no need to use specially prepared resins, and commercially available products may be used. The higher fatty acid salt used in the present invention may be selected from, for example, calcium stearate, potassium stearate, sodium stearate, calcium palmitate, potassium palmitate, sodium palmitate, etc., but from the economic point of view stearate, Particularly preferred is calcium stearate. These are then preferably used as the water dispersion. A preferred embodiment of the mortar and concrete efflorescence inhibitor according to the present invention includes soluble alkaline earth metal salt 100
5 parts by weight of amino resin or amino alkyd resin
0 to 150 parts by dry weight, and 5 to 25 parts by weight of a higher fatty acid salt, most preferably a 33.3% aqueous solution containing 100 parts by weight of a soluble alkaline earth metal salt (e.g. calcium chloride). 300 parts by weight, 80 to 140 parts by dry weight of amino resin or amino alkyd resin,
and higher fatty acid salts (e.g. calcium stearate) 7
．． It consists of 71 parts of 5 to 15 folds. If the amount of resin is less than this, the efflorescence prevention ability will gradually decrease.
If the amount is too large, the uniform mixability of the composition liquid begins to deteriorate. Furthermore, if the higher fatty acid salt is used in an amount greater or less than this, the anti-efflorescence ability will gradually begin to decrease. <Embodiments> Below, preferred embodiments of the present invention will be described in detail by way of example. However, unless there is a specific description, the scope of the present invention is not intended to be limited thereto, and is merely an illustrative example. Incidentally, parts and % in the following explanations mean parts by weight and % by weight, respectively. The anti-efflorescence agent of this example was prepared using the following components.

[Ingredients] Calcium chloride Commercially available anhydrous calcium chloride urea resin Product name: Igetalime UA-125,1 (manufactured by Sumitomo Bakelite Co., Ltd.) Melamine resin Product name: Igetalime MR-IJ (manufactured by Sumitomo Bakelite Co., Ltd.) Urea alkyd resin product name [Aikaratsuku CU-2805J (manufactured by Aikanigyo Co., Ltd.) Calcium stearate commercially available water dispersion with a solid content of 50%

[Preparation of composition]

B) Preparation method 1 Add 45 parts by dry weight of urea resin to 100 parts of a calcium chloride aqueous solution with a concentration of 33.3%, disperse or dissolve it, then add 8 parts of water dispersion of calcium stearate, and further add 200 parts in total. Sample 1 was obtained by adding methanol until . Sample 2 was obtained in the same manner by adding melamine resin instead of urea resin. Then, sample 3 was obtained by adding urea alkyd resin instead of urea resin. Preparation method 2 Add 6.5 parts by dry weight of urea resin I to 100 parts of a calcium chloride aqueous solution with a concentration of 33.3%, disperse or dissolve it, then add 8 parts of water dispersion of calcium stearate, and further add the total amount. Sample 4 was obtained by adding methanol to 200 parts. Sample 5 was obtained in the same manner by adding melamine resin instead of urea resin. Then, sample 6 was obtained by adding urea alkyd resin instead of urea resin. c) Preparation method 3 Calcium chloride aqueous solution with a concentration of 33.3% 100 ff+
After adding 30 parts by dry weight of urea resin and dispersing or dissolving it, 28 parts of water dispersion of calcium stearate was added, and methanol was further added until the total amount became 200 parts to obtain Sample 7. Sample 8 was obtained in the same manner by adding melamine resin instead of urea resin. Sample 9 was then obtained by adding a urea alkyd resin instead of the urea resin. 2) Preparation method 4' In 100 parts of calcium chloride aqueous solution with a concentration of 33.3%,
After adding and dissolving 45 parts by dry weight of urea alkyd resin, 3.5 parts by weight of calcium stearate water dispersion.
sample 10 was obtained by adding methanol until the total amount reached 200 parts. E) Co-N manufacturing method 5 Add n parts of 45 dry weight of urea alkyd resin to 100 parts of calcium chloride aqueous solution with a concentration of 33.3%, and after dissolving, add 16 parts of aqueous disverzidine of calcium stearate, and further Sample 11 was obtained by adding methanol until the total amount was 200 parts. f) Comparative Example 1 Sample 12 was obtained by preparing according to Preparation Method 4 except that calcium stearate was removed. g) Comparative Example 2 Sample 13 was obtained using only calcium stearate. h) Comparative Example 3 Sample I4 was obtained using only a completely water-soluble urea resin. W) Comparative Example 4 Sample 15 was obtained using only a completely water-soluble melamine resin. n) Comparative Example 5 Sample 16 was obtained using only an aqueous calcium chloride solution. ) Comparative Example 6 Sample 17 was prepared without adding any additives.

[Efflorescence test method]

To cement mixed with 1 part of ordinary Portland cement, 3 parts of sand, and 0.75 parts of water, 1.0% of each type of anti-efflorescence sample was added to 10X1.0X10c.
It was molded into a cement mortar prismatic body (x), cured in humid air for 24 hours (20°C, R890%), and then demolded. These cement mortar prismatic bodies were cut in a width of 2cx in the longitudinal direction, and each test piece was designated as IOX IOX 2cx. The IC shoulder in the thickness direction of the obtained test piece was immersed in water at 5°C, and the whole was left in an environmental container at 5°C with RI (50%, wind speed 0, 2-0.3z/sea) for 14 days. The degree of occurrence of efflorescence was visually observed and the results are summarized in Table 1. The degree of occurrence of efflorescence was determined as follows: ◎ No efflorescence occurred at all. ○ Extremely Slight efflorescence occurred. △ Efflorescence occurred to the extent that the appearance was impaired. × Efflorescence occurred severely (Table-1) Sample 3 and sample 12 were used separately, and the addition ratio to cement was 1%, 2%, and 3%. When a water absorption test was conducted according to JIS-A1404, the results shown in Table 2 were obtained. <Effects of the Invention> The anti-efflorescence agents of the present invention are not effective when used alone, but when mixed together Possibly mortar, concrete 0
It is useful because it has the unprecedented effect of being able to suppress emotions under a wide range of environmental conditions. In addition, as an additional effect, it has a waterproofing effect as shown in Table 2, which suppresses the elution of concrete components and is therefore effective in preventing alkali corrosion of aluminum sash, etc., and its uses are wide.

Claims (1)

[Scope of Claims] 1) An efflorescence preventive agent for mortar and concrete, characterized by containing a soluble alkaline earth metal salt and an amino resin or an amino alkyd resin as main components, and a higher fatty acid salt as an auxiliary component. 2) For 100 parts by weight of soluble alkaline earth metal salt,
The efflorescence inhibitor for mortar and concrete according to claim 1, which contains 50 to 150 parts by dry weight of an amino resin or amino alkyd resin and 5 to 25 parts by weight of a higher fatty acid salt.