JPS60260459A - Gypsum water slurry composition - 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 water slurry of gypsum.

More specifically, it relates to a gypsum water slurry composition that greatly reduces the amount of pleating water when the mixing water floats up before the gypsum hardens (hereinafter referred to as "pleasing"), and has good dispersibility. .

[Prior art]

Gypsum is used for a variety of purposes, including in the architectural field, such as gypsum plaster, gypsum bond, and gypsum flooring, and in the ceramic industry, such as molds. When this gypsum is used, it is usually made into a slurry of water, which is cast or poured into a predetermined shape, and then hardens due to its hydraulic properties to form a hardened product for use. At this time, disperse the 2 plasters,
Gypsum dispersants are commonly used to reduce the viscosity of slurries and improve workability.

On the other hand, if the kneading water precipitates before the plaster hardens, two types of open circuits will occur. When the kneading water precipitates, the strength of the surface of the cured product decreases significantly, and
Its smoothness also decreases.

In the field of gypsum flooring and molding, this pleating is particularly problematic. As a dispersant for gypsum, lignin sulfonate, salt of formalin condensate of naphthalene sulfonic acid, salt of formalin condensate of melamine sulfonic acid, etc. are used. Among these dispersants, lignin sulfonate-based ones have low dispersibility in gypsum;
It has the disadvantage of having to be used in large quantities.

Moreover, if a large amount is used and its dispersibility is improved, the amount of water for pre-preparation increases, and furthermore, it has the disadvantage of slowing down the curing speed of 1 gypsum.

Ring-based formalin condensates of naphthalene sulfonic acid have better monodispersibility than lignin sulfonate-based ones, but it is still difficult to say that they have sufficient dispersibility, and they also tend to cause wear and tear. Water t is as large as the ligninsulfonic acid type. Furthermore, the ring-based formalin condensate of 5 melamine sulfonic acid has good performance, such as good bidispersity and little plucking.

It is expensive and has major economic problems.

The present invention was completed as a result of intensive research based on the above circumstances.

[Purpose of the invention]

The object of the present invention is to reduce the amount of breathing water.

The present invention also provides a gypsum aqueous slurry composition that has good dispersibility and is economically superior.

[Structure of the invention]

The present invention is a gypsum water slurry composition in which gypsum is dispersed in water using a polymer of sulfonated dicyclopentadiene as a dispersant.

The gypsum used in the present invention is not particularly limited as long as it is industrially used; for example, gypsum hemihydrate (CaS
O,! -H, 0, α- or β type), anhydrite (CaS
O4) and trihydrate (Ca5o42H,O). Among these, hemihydrate gypsum, which has hydraulic properties, is often used. Particularly preferred is α-hemihydrate gypsum.

In the case of mixing gypsum and water in the present invention, the mixing ratio (weight basis) is α-hemihydrate gypsum, and usually ice digypsum = 6
5 to 25:100, and in the case of β-hemihydrate gypsum, the ratio is 2 normal sulfur gypsum = 65 to 85:100.

The dispersant used in the present invention is a polymer of dicyclopentadiene (represented by the following general formula (5)) having a sulfonic acid group (this polymer includes a co-polymer). .

(In the formula, M represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, ammonium or t-1 amine, and n is an integer of 1 or 2.) As the alkali metal in the above general formula (5), Sodium, potassium, etc. can be mentioned, and examples of amines include methylamine, ethylamine, propylamine,
Dimethylamine, diethylamine, trimethylamine,
Examples include alkylamines such as triethylamine, butylamine, dibutylamine, and tributylamine; boinoamines such as ethylenediamine, diethylenetriamine, and triethylenetetramine; morpholine, piperidine, and the like; examples of alkaline earth metals include calcium.

Examples include magnesium. Moreover, these M can be mutually exchanged with other types of M by various ion exchange techniques or by neutralization reaction at °C.

The weighted average molecular weight of the polymer is preferably 500 or more, more preferably 2000 or more, and 3
500 to 50,000 is most preferable.

The polymer can be mutually exchanged into an acid form or a salt of an alkali metal, alkaline earth metal, ammonium, amine, etc. by an ion exchange method or a neutralization reaction.

An example of a method for producing the polymer will be explained. (Detail is%
It is described in Japanese Patent No. 57-175666. ) Synchlopentadiene is sulfonated, and then, if necessary, a compound of general formula (A) is obtained as a sulfonate, and this compound is subjected to a chassis reaction, for example, in the presence of an acidic compound catalyst. In the polymerization reaction, a copolymerizable monomer such as an aliphatic, alicyclic, or aromatic hydrocarbon having an olefinic double bond is present to obtain a copolymer ii'. In the case of a copolymer, in order to keep air entrainment low, the content of sulfonated substances in the copolymer is 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more.

The amount of the dispersant added is 1. ! #Usually 0.05 to 5% by weight, preferably 0.1 to 3%.

If the amount added is less than 0.05% by weight, the dispersibility will be low, and if it exceeds 5% by weight, no improvement in the dispersibility will be observed. .

The dispersant is usually added when gypsum and water are mixed, but other methods of addition, such as adding it to gypsum in advance, can also be used.

In the present invention, one dispersant can be used in combination with other optional components. Such optional ingredients include known ingredients such as curing accelerator (sodium sulfate).

(sodium chloride, etc.), curing retarders (alcohol, sugar,
starch, etc.), other gypsum dispersants (sodium polyacrylate,
Calcium ligninsulfonate, condensates of sodium naphthalenesulfonate and their modified products, condensate salts of melaminesulfonic acid, sodium ligninsulfonate, etc.), other gypsum foaming agents (dodecylbenzenesulfonic acid, etc.), etc. . Further, it is preferable to use finely powdered silica in combination for the purpose of significantly reducing the amount of breathing water and improving the dispersibility of gypsum. In this case, the weight ratio of the dispersant to the finely powdered silica is usually 70:30 to 97:3, preferably 80.
: 20-95:5. If the amount of finely powdered silica is less than 3 parts, the synergistic effect will be small and the dispersibility and amount of breathing water will be the same as when the dispersant is used alone. Furthermore, if the amount of finely powdered silica is more than 30 parts, although the amount of breathing water decreases, the dispersibility actually decreases.

Furthermore, the dispersibility may be further improved when an oily substance consisting of mineral oil, synthetic lubricating oil, and fatty oil is used in combination.

Ordinary mineral oils may be used, including those commonly referred to as petroleum-based lubricating oils. This stuff is normal.

Boiling point approximately 3 obtained as distillation residue from atmospheric distillation of crude oil
Heavy oil at a temperature of 00°C or higher is separated into various distillate oils and residual oils by vacuum distillation, and each is subjected to appropriate refining treatments before being made into a final product. A specific example of petroleum-based lubricating oil is spindle oil (JIS standard white-, 60-, separate-1150-spindle oil, etc.).

There are no particular restrictions on the form of mineral oil, and it can be a single mineral oil.

Various forms are used, such as emulsions of mineral oil and powders in which mineral oil is adsorbed on an inorganic carrier.

Examples of synthetic lubricating oils include silicone oil, polyalkylene glycol oil (diester oil, olefin polymerized oil, other synthetic lubricating oils, and mixtures thereof).

Fatty oils include vegetable oils and animal oils. In addition, oils include non-drying oils, semi-drying oils and drying oils.

Among the oily substances mentioned above, preferred ones are: Mineral oil 1
Synthetic lubricating oils and mixtures thereof.

In addition, when a mixed system is used as the oily substance, two or more types of oils do not necessarily have to be mutually soluble.

Add an oily substance to the dispersant, optionally added finely powdered silica □ to improve dispersibility.

The weight ratio of the oily substance to the total weight of the dispersant and finely powdered silica is usually 0.5 to 25. Preferably it is 2-20. If the amount of oily substance is less than 0.5 parts, no improvement in dispersibility is observed, and if it exceeds 25 parts, not only the dispersibility decreases but also 9
An oil film of mineral oil, silicone oil, realkylene glycol oil, etc. may be formed on the surface of the hardened gypsum, and the strength of the hardened gypsum surface may be reduced.

〔Example〕

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

Reference Example 1 In a stainless steel autoclave (1,30 liters) equipped with a stirrer and a thermometer, 30 ml of dicyclopentadiene was added.
・0・Ol, sodium bisulfite 1888.9 potassium nitrate 9L711. Isopropyl alcohol 1°1. E
z, DXM*30001/-ゎ, ! After supplying nitrogen until the internal pressure in the mF, d-1-tralepe reached 1.0% (gauge pressure), the pulp was sealed and reacted at 110°C for 5 hours while mixing under strong stirring. I let it happen. After that, it was allowed to cool to room temperature, and after removing most of the isopropyl alcohol by distillation, distilled water and petroleum ether were added and thoroughly mixed, the petroleum ether layer that separated and the precipitate were removed, and the resulting aqueous layer was concentrated. , distilled to dryness. This was dissolved in glacial acetic acid, and the acetic acid insoluble portion consisting of inorganic salts was separated using a centrifuge. A white solid 2800.9 was obtained by concentrating the obtained acetic acid soluble content. (After converting this aqueous solution of sulfonated compound A into the acid form using an ion exchange resin, the water was concentrated to dryness to obtain the acid form of the sulfonated compound. 150 g of the above-mentioned sulfonated compound B, 709 g of sulfuric acid, and 45 g of water were placed in a three-tube flask with a capacity of 11 equipped with an apparatus.

The polymerization reaction was carried out at a temperature of 120° C. for 26 hours. After completion of the reaction, liming and soda john were performed, and the solid content obtained was 157 g.

The weight average molecular weight of this polymer was 13,200.

This is designated as “Sample IJ.

Reference Example 2 A polymer having a weight average molecular weight of 3,800 was obtained by carrying out the same treatment as in Reference Example 1 except that sulfonated compound A was used. This will be referred to as "Sample 2."

Reference Example 3 In Reference Example 1, one polymerization reaction was carried out using 150 g of sulfonated product A.
using sulfuric acid 1509. Add 45g of water.

The reaction was carried out at a temperature of 130°C for 28 hours. Otherwise, the same treatment was performed to obtain a polymer having a weight average molecular weight of 8,600, which was designated as "Sample 3".

Reference Example 4 Sulfonated compound A was copolymerized with 130.9° of sulfonated compound A in a 130.9° synchropentadiene flask equipped with a reflux condenser and a stirrer, and 2 ml of synchropentadiene (1. After the reaction, liming and nodition were performed, and the solid content obtained was 158&.

The weight average molecular weight was 13,500. (Sample 4) Reference Example 5 A 11-volume Mitsulo flask equipped with an R-flow condenser and a stirrer was charged with 10 OX 9° of acrylic acid, 150 ml of acrylic acid, 150 ml of sulfuric acid, and 40 ti of water, and polymerized at 120°C for 26 hours. I let it happen.

After the polymerization, the solid content was 151 g, and the weight average molecular weight was 14,100. This is designated as sample 5.

Examples j-12. Comparative Examples 1-2 100 parts by weight of α-hemihydrate gypsum (including setting retarder) and 3 parts water
0 heavy leaf part and various dispersants in Table 1 (Reference Examples 1 to 5) were added in the amounts shown in Table 1, and after stirring for 30 seconds, immediately
Dispersibility measurement (flow value measurement.

(viscosity measurement) and pleating water volume measurement.

The results shown in Table 1 were obtained.

[Measurement method]

Flow value measurement glass plate): Pour gypsum slurry into an inner cylinder with a diameter of 4 Q mw = internal volume of 90 wal,
Pull up the tube and measure the spread of the gypsum slurry on the glass plate.

Viscosity measurement: Measured using a BL type viscometer at a rotor speed of 3.6° rpm.

Breathing water amount: In a 200+nJ graduated cylinder with a diameter of 2501+.

Pour 100+++l of gypsum slurry and let it stand for 1 hour.
Measure the amount of water breathing onto the slurry surface.

〔Effect of the invention〕

As is clear from Table 1, the effects of the present invention are a gypsum water slurry composition that has a greatly reduced amount of pleating water and has good dispersibility. Incidentally, suitable uses of the gypsum slurry composition include 1 gypsum board, C/I/7 leveling material, and the like.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] Sulfonated dicyclopentadiene as a dispersant
A gypsum water slurry composition in which gypsum is dispersed in water using coalescence. .