JPS597494A - Water glass composition - Google Patents

Abstract

PURPOSE:To provide a binder for a coated welding rod which has excellent viscosity and tackiness and is free from phase sepn., by adding the sodium salt of carboxymethylcellulose having a high rate of etherification to water glass. CONSTITUTION:The sodium salt of carboxymethylcellulose having >=1.0 rate of etherification is added to a water glass soln., and the mixture is used as a binder in the stage of coating a flux on a coated welding rod. A compsn. which does not separate to two phases even if it is left standing for a long time and is usable at all times as a flux binder is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water glass composition, particularly to a water glass composition with improved liquid external properties such as viscosity and stickiness.

Water glass is used in a wide range of applications such as cleaning agents, penetrants, bonding agents, adhesives, soil hardening agents, and fire retardants. Depending on the application, it may be necessary to improve the liquid properties, such as adding a lubricant to improve the slipperiness. In the case of coated welding rods, sodium alginate is used as a lubricant, and according to the literature, sodium salt of carboxymethyl cellulose (hereinafter abbreviated as cMcJ) is also used for the same purpose, but 1゜CMC is generally used as a water-soluble thickener, and is used in various fields because it can be used in foods. It should be possible to use it as a property improving agent, but commercially available CMC does not form a homogeneous liquid when mixed with water glass and separates into two phases in a short time, so it must be used immediately after mixing. There are cases where people use it even though they are aware of the inconvenience, but it is not put to practical use.

On the other hand, in terms of individual applications, the alginate soda used in the case of the welding rod is a natural product, is expensive, has large price fluctuations, and has unstable properties, so a substitute has been sought.

As a result of various studies, the present inventor found that CMC has a higher degree of etherification than commercially available CMC (degree of etherification: 0.5 to 0.9).
It has been found that MC is compatible with water glass. In other words, if the degree of etherification is LO or higher, it will be stable for more than 1 hour after mixing, so in most cases, the i? It can be used if it is a + book (no history in the content) (→ at the beginning). The relationship between the degree of etherification and the compatibility is shown in Table 1. When the degree of etherification is 15 or more, it is dramatically improved to the extent that it can be treated as a separate substance, and there is no fear of phase separation. Table (note) Water gaff, L is S i Q, / Na, O ratio λ5
The 55Be aqueous solution of anhydrous glass has a CMC of 1 weight 96
The results were obtained by adding an aqueous solution and observing the separation time.

CMC with a degree of substitution of 10 or more can be produced by a normal manufacturing method or by repeating a conventional method, but CMC with a degree of substitution of 15 or more is inefficient in such a method, so the present applicant The method disclosed in Japanese Patent Application No. 57-60576 is that a predetermined amount of monochloroacetic acid is added to the cellulose at the start of the reaction, and alkali is added in stages.
In other words, if the etherification reaction is carried out with an excess of monochloroacetic acid, CMC with a high degree of substitution can be obtained with little loss of monochloroacetic acid. 2 times]'
A compound with a degree of substitution of 3 is obtained. In contrast to the conventional method in which a predetermined amount of monochloroacetic acid and a predetermined amount of alkali are charged at the start of the total reaction, the loss of monochloroacetic acid is large and the etherification reaction must be repeated at least four times. It is.

In particular, when the degree of substitution is about 15, where the effects of the present invention are remarkable, the method of Japanese Patent Application No. 57-60576 can efficiently perform a single reaction, but the conventional method is close to the limit of a single reaction, and the efficiency is low. If the degree is 1.8 or more, it cannot be obtained by repeating at least two times using the conventional method.

In general, the mixing ratio of anhydrous glass and CMC with an etherification degree of 10 or more is 0.1 for products mixed with water glass.
It can be selected as appropriate between 99.9 and 99.9:0.1 (weight ratio) depending on the use and purpose, but when added as a lubricant to the coating material of welding rods, about 10% by weight of the total is sufficient. The purpose is achieved.

Next, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example water glass (55B'e) 61.3%, CMC09
%, water 37.8%, 250 parts by weight, 1 part by weight, lime carbonate (50 parts by weight), fluorite (18 parts by weight), ferron licon (13 parts by weight, 171 parts), and 1 part by weight (19 parts by weight). )
The mixture was mixed with 100 parts by weight of ordinary fura or alcoholic beverages consisting of.

This mixture remained stable without separating into two phases even after being left overnight, and had good paintability on metal core wires.

Patent Applicant: Daicel Chemical Industries, Ltd. Procedural Amendment Form) % Formula %)
＋SAlso, the name of the invention (Draft J), the name of the invention (Draft J), the relationship with the case of the person making the amendment, and the applicant at the time.

Claims (1)

[Claims] A water glass composition comprising water glass and a sodium salt of carboxyl methyl cellulose having a degree of etherification of 10 or more.