JPS5918336B2 - gypsum composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in gypsum compositions for use in building materials such as flooring and wall materials.

Recently, with the effective use of gypsum, building materials, especially flooring materials,
Gypsum compositions with good fluidity, the main component of which is strong alpha gypsum gypsum, are increasingly being used for wall materials and the like.

This highly fluid gypsum composition contains various additives such as water reducing agents, anti-floating agents, antifoaming agents, hardening regulators, etc., and is an all-premix product that can be used as a raw material for flooring, wall materials, etc. It is used in various ways.

However, there are many problems, especially when a water reducing agent such as melamine formalin resin sulfonate is used, since the storage stability of the product is not very good.

For example, even if natural gypsum is used as plaster,
℃, the curing time was delayed by more than twice in 20 days.

In addition, the fluidity of the product using phosphorescence decreases by about 40% after 1.5 months at room temperature and 15 days at 40°C.

Therefore, the current situation is that even premixed products are readjusted at the time of use, or adjusted each time by adding additives immediately before use.

The purpose of the present invention is to suppress the deterioration of the fluidity of a premixed gypsum composition over time, and to create a gypsum composition that maintains a constant quality during the normal use period (b months after manufacture), It is made of a gypsum composition characterized by adding silicofluoride to the set (branch) proboscis, which is mainly composed of alpha gypsum gypsum with addition of additives.

There are α-type and β-type hemihydrate gypsum, and the α-type hemihydrate used in the present invention is particularly strong.

It is usually preferable to use hydraulic cement such as Portland cement.

If hydraulic cement is used in combination, stability and external strength will also be improved.

The additive used is melamine formalin resin sulfonate (product name: Melment, manufactured by Showa Denko K.K.)
), alkylaryl sulfonate (trade name: Mighty 100, manufactured by Kako Atlas Co., Ltd.), water reducing agents such as methyl cellulose, polyvinyl alcohol, etc., potassium sulfate, aluminum sulfate, and sodium oxalate. , protein-based curing modifiers, silicone resin-based (product name: X5O-418, manufactured by Shin-Etsu Chemical Co., Ltd.),
Polyoxyethylene type (product name: Nopco, San Nopco (
Additives commonly used in gypsum compositions, such as antifoaming agents such as those manufactured by Co., Ltd., can be used as they are.

The present invention is characterized in that a silicofluoride is used together with these additives.

As the silicofluoride, alkali metal salts and alkaline earth metal salts are preferably used, and potassium salts and sodium salts are particularly preferred.

The amount used is 0.02 to 0 for external machining relative to the gypsum composition.
．． 5% by weight is good.

If the amount added is less than 0.02% by weight, no effect will be obtained;
Moreover, if it is more than 0.5% by weight, the fluorine content will affect the physical properties of the molded product, which is not preferable.

In the present invention, when 0.1% by weight of silicofluoride is added, the fluidity decreases by about 10% in 20 days at 40° C., and the curing time is delayed by 10 minutes or less.

Therefore, it is stable for more than 3 months at room temperature, and can be sold in bags as a premix product if it has a normal use period.

Next, Examples and Comparative Examples will be explained.

Example 1 2,800 g of phosphoric acid by-product α-watch plaster, 700 g of ordinary Portland cement, melamine formalin resin sulfonate (trade name: Melment, manufactured by Showa Denko K.K.),
After mixing 3.5 g of sodium fluorosilicide with a V-type mixer for 30 minutes, it was sealed in a plastic bag and left in a hot air dryer with a diameter of 40°C for a specified number of days, and the flow value and condensation time were measured over time. did.

As a result, the flow rate was 25% with 1 caliber kneading water content.
0 m/m, the apparent final 25 minutes was 40°C,
After 20 days, the flow was 298 m/m and the apparent finish was 35 minutes, a change of only 10% in flow and 10 minutes in setting time.

This corresponds to stability of more than 3 months at room temperature.

Example 2 The same treatment as in Example 1 was performed except that potassium fluorosilicide was used instead of sodium fluorosilicide in Example 1.

As a result, the flow rate was 224 with 1 caliber kneading aqueous ratio 25 parts.
m/m, apparent termination of 25 minutes, 40°C, 20
After a day, the flow was 202 m/m and the apparent final time was 35 minutes, and the flow had changed by only 10 minutes at 10% condensation time.

This corresponds to stability of more than 3 months at room temperature.

Example 3 2,800 g of natural alpha gypsum, 700 g of ordinary Portland cement, 42 g of melamine formalin resin sulfonate (mentioned above), 1.4 g of methyl cellulose (trade name Nimetrose, manufactured by Shin-Etsu Chemical Co., Ltd.), protein System curing retarder (product name: RTK-5, manufactured by Sannis Gypsum Co., Ltd.) 1
0.5 g and 3.5 g of sodium fluorosilicide were mixed, and the same treatment as in Example 1 was carried out.

As a result, the flow rate was 205 with a mixing ratio of 1 diameter and 25% of the water content.
The mA apparent termination of 27 minutes became an apparent termination of 38 minutes at 40° C., 20 days, 1 flow of 200 m/m, and the flow changed by only 11 minutes at 2.5% condensation time.

This corresponds to stability of more than 3 months at room temperature.

Comparative Example 1 After mixing 2,800 g of phosphoric acid by-product α Gypsum, 700 g of ordinary Portland cement, melamine formalin resin sulfonate (mentioned above), and 35 g of sulfuric acid IJ in a type mixer for 30 minutes, It was sealed in a bag and left in a hot air dryer with a diameter of 40° C. for a predetermined number of days, and changes in flow value and coagulation time over time were measured.

As a result, the flow rate was 23 with a mixed 1-caliber mixed hydrophobic outer ratio of 25%.
4 m/m, apparent final 30 minutes is 40°C21
After 0 days, the flow was 11Q 3 m/m, with an apparent end of 42 minutes, and on the 20th, 1 flow was 126 m/m, with an apparent end of 49 minutes, which showed a large change over time.

Also, if you do not add normal Portland cement, 40
It deteriorated after 1 day at ℃.

Comparative Example 2 When a product with exactly the same composition as Comparative Example 1 was left indoors,
On day 30, one flow was 212 m/m s, with an apparent termination of 37 minutes, and on day 45, one flow was 193 m/m, with an apparent termination of 44 minutes, and it was stable for only about one month even at room temperature.

Comparative example 3 Natural α Kite water gypsum 2. s o o g, ordinary Portland cement 700g, melamine formalin resin sulfonate (mentioned above) 42L Methyl cellulose (mentioned above) 1.4
．． After mixing 10.59 of a protein-based hardening retardant for 30 minutes in a V-type mixer, seal it in a plastic bag and leave it in a hot air dryer at 40°C for a predetermined number of days to determine the flow value and setting time. The changes over time were measured.

As a result, after one day of mixing, 217% of the flow was mixed with 25 parts of kneading water.
m/\apparent final time of 25 minutes, after 20 days at 40°C, the flow became 212 m/m and the apparent final time was 52 minutes, which showed a large change over time.

Comparative Example 4 The same treatment as in Comparative Example 1 was carried out except that the potassium sulfate was replaced with sodium oxalate.

As a result, after 18 minutes of mixing, 25 parts of kneading water was used to form a flow of 19577.
1/is apparent final time of 27 minutes changed significantly over time, at 40°C, 1 flow rate was 161 m/m on 10 days, and flow rate was 75 km/m after 20 days.

As mentioned above, the use of fluorosilicide greatly improves the stability of the gypsum composition, making it possible to mix all the materials and sell them in bags as a premix product.
We can always supply stable gypsum products.

Claims (1)

[Scope of Claims] 1. A gypsum composition characterized in that it is made by adding silicofluoride to a composition whose main component is alpha gypsum gypsum, which is made by adding an additive such as a water-reducing agent. 2. The gypsum composition according to claim 1, wherein the silicofluoride is an alkali metal salt. 3. The gypsum composition according to claim 1, wherein the silicofluoride is an alkali metal salt.