JPS61168557A - Manufacture of lightweight gypsum product - 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] 1 Junkosuke The present invention relates to lightweight gypsum products containing air bubbles.

Gypsum board, which has been widely used as a building material in the past, is being made lighter in order to reduce industrial labor and prevent it from falling off due to its own weight. Such lightweight gypsum products are made by adding a surfactant as a foaming agent into the gypsum slurry to introduce air bubbles.
The slurry is then dried and molded to produce the product.

Traditionally, as surfactants, alkylbenzene sulfonates, higher alcohol sulfate ester salts, polyoxyethylene alkyl sulfate ester salts, rosin soaps, etc. have been used, and α-olefin sulfonates (Japanese Patent Publication No. 52-32763 It is also proposed to use the official gazette).

However, although some of these surfactants have excellent foaming power, they tend to produce coarse foam, break, or have a short foam duration, making them even more difficult to use. Improvements were made over time.

INDUSTRIAL APPLICABILITY The present invention provides a method for easily producing a lightweight gypsum product with a low specific gravity and a stable foaming property in a gypsum slurry.

Hikari 11-1 Yield The method for producing a lightweight gypsum product of the present invention includes forming a gypsum slurry with air bubbles mixed therein to produce a lightweight gypsum product. Characterized by the addition of sulfonates.

Internal olefin sulfonate has 10 or more carbon atoms.
It is a neutralized salt of a sulfonated product of internal olefin No. 18, preferably No. 14 to 16, and contains alkenyl sulfonate and hydroxyalkanesulfonate as main components. The internal olefin sulfonate used in the present invention has, for example, the general formula R-CH=CH-R'C, where R and R' are each a linear or branched saturated carbon group having 1 or more carbon atoms. Yes, the sum of the carbon numbers of R and R' is 8 to
It is 16. ) is the main component, and in some cases, trisubstituted monoolefin (R-CH
=CR'R"), neutralized with a suitable base, and optionally hydrolyzed. The internal olefin sulfonate thus obtained usually has a 10~
60% by weight alkenyl sulfonate and about 90-40%
% by weight of hydroxyalkanesulfonates, while containing about 80% by weight or more of monosulfonates and up to about 20% by weight of disulfonates.

Internal olefin sulfonates suitable for the present invention contain about 40% by weight or more of hydroxyalkanesulfonate, preferably about 45 to 90% by weight, and about 20% by weight or less of disulfonate, preferably about 0.1 to 90% by weight. 1
It contains 5% by weight or less. In addition, as salt,
Alkali metal salts are suitable, preferably sodium or potassium salts.

Any conventional method can be adopted as a manufacturing process for lightweight gypsum products using internal olefin sulfonate as a blowing agent. For example, first, water and internal olefin sulfonate are mixed to prepare an aqueous blowing agent solution, gypsum and other additives such as pulp and starch are added to this to form a paste-like gypsum slurry, and then a foaming agent such as lignin sulfonic acid is added. After adding a water reducing agent and aging,
Form and dry to obtain plasterboard.

The internal olefin sulfonate is suitably added in an amount of 0.1 to 1.0 parts by weight, preferably 0.4 to 0.8 parts by weight, per 100 parts by weight of gypsum.

According to the present invention, by using an internal olefin sulfonate having 10 to 18 carbon atoms as a blowing agent,
Since it is possible to effectively prevent bubbles from becoming coarse and uneven, and to form bubbles that are hard to burst, stable, and long-lasting, lightweight plaster products with low specific gravity can be easily manufactured.

Using various internal olefin sulfonates and conventional surfactants shown in Table 1 below in Examples as blowing agents,
Performance evaluation was performed using the following method, and the results are summarized in Table 1.

(1) RkM method (JI
SK-3362).

(2) Gypsum slurry: 0.6 parts by weight of specific gravity foaming agent, 80 parts by weight of water, and 100 parts by weight of calcined gypsum
The parts by weight were mixed using a mixer, and the specific gravity of the resulting slurry paste was measured.

Specific gravity of slurry paste = Step 1-Pace 100
0ra Q water 1000s (l weight (3) gypsum board specific gravity (2) gypsum slurry obtained from 150ma x 180m
+m x 9cm container, after molding and aging, 160~1
A gypsum board was prepared by drying at 00° C. for 60 minutes, and its specific gravity was measured.

In addition, gypsum boards were prepared in the same manner except that the amount of the foaming agent added was changed, and the specific gravity thereof is shown in Table 2.

(Margin below)

Claims (1)

[Claims] 1. When manufacturing a lightweight gypsum product by molding a gypsum slurry mixed with air bubbles, the gypsum slurry contains 10 carbon atoms.
A method for producing a lightweight gypsum product, characterized in that an internal olefin sulfonate of ~18 is added.