JPH0761889B2 - Water repellent gypsum composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-repellent gypsum composition having unprecedented excellent performance. More specifically, it relates to a water-repellent gypsum composition having improved water resistance and workability.

[Conventional technology]

Products using gypsum, such as gypsum board and gypsum plaster,
Due to the characteristics of gypsum, there are problems with water resistance despite the remarkable features of fireproofing, soundproofing, strength, and low price, and the range of use is currently limited.

Various methods have been proposed to compensate for the drawbacks of gypsum. For example, a method of adding asphalt or paraffin as powder and melting after molding, a method of emulsifying and adding asphalt and paraffin, a method of adding a silicone compound or synthetic resin emulsion, etc. No satisfactory performance was obtained. Use of paraffin and oxidized paraffin as water repellency-imparting agents to improve the above-mentioned drawbacks (Japanese Patent Publication No.
-50906), using a wax and a carboxyl group-containing wax (JP-A-55-37423), and using a paraffin and a saturated fatty acid adduct of olefin (JP-A-60-1).
4932), using wax and styrene-maleic anhydride monoester (JP-B-58-58304),
Those using an alkyl or alkenyl succinate and a water-soluble compound of aluminum (JP-A-55-113650) have been proposed.

[Problems to be solved by the invention]

However, in these methods, if there are not many auxiliaries used when emulsifying wax or paraffin, the water repellency-imparting property to gypsum and the stability in gypsum slurry are insufficient, or the auxiliaries or water repellents are used. There were problems such as high cost of the agent itself.

[Means for solving problems]

The inventors of the present invention have conducted diligent studies on a method for solving such a problem, and when emulsifying waxes, surprisingly, when an olephine-maleic anhydride derivative is used, a gypsum slurry of emargyon produced even in a small amount thereof is used. It was found that the gypsum slurry had good stability in the interior, and the gypsum slurry also had good fluidity and water repellency, and thus reached the present invention.

That is, the gist of the present invention is a paraffin emulsion obtained by emulsifying (A) waxes having a melting point of 40 to 90 ° C. and (B) an olefin-maleic anhydride derivative in water in the presence of (C) a water-soluble alkaline compound. A water-repellent gypsum composition containing (D) gypsum and an emulsion containing (F) polyvinyl alcohol. Hereinafter, the present invention will be described in detail.

Melting point 40-90 ° C, which is one component of the water-repellent gypsum composition of the present invention
The waxes are paraffinic or olefinic hydrocarbons. Specifically, Paraffin Wax,
Examples include Montan wax and low melting point polyolefin wax.

If the melting point of waxes is lower than 40 ° C, the quality of the product deteriorates in summer, and if it is higher than 90 ° C, a product having good water repellency cannot be obtained.

The other component, an olefin-maleic anhydride derivative, is obtained by low polymerization of α-olefin having 4 to 6 carbon atoms or α-olefin having 2 to 5 carbon atoms such as ethylene, propylene, isobutylene and isoamylene. Addition product of maleic anhydride with linear or branched olefin having a double bond at the α-position having 4 to 60 carbon atoms, and these α-
Copolymers obtained by copolymerizing olefin and maleic anhydride with a radical initiator, and partial esters of these organic monohydroxy compounds are used. The partial ester may be synthesized after the reaction between olephine and maleic anhydride, or by the reaction between the partial ester of maleic anhydride and olein. The molar ratio of olefin and maleic anhydride or its partial ester is 3: 1 to 1: 2.
Is preferred. If the molar ratio is out of this range, the stability of emulsion or the water repellency of the gypsum composition is impaired, which is not preferable.

Examples of the organic monohydroxy compound used for producing the partial ester include alcohols such as methanol, ethanol, isopropanol, butanol, and 2ethylhexanol, and cellosolves such as butyl cellosolve and ethyl cellosolve. The organic monohydroxy compound is used in the range of 1 mol or less relative to 1 mol of maleic anhydride. The reaction of the organic monohydroxy compound with maleic anhydride or an olefin-maleic anhydride derivative is carried out under normal pressure or, if necessary, under pressure in an autoclave at 90 to
It is carried out at a temperature of 130 ° C for about 1 to 10 hours.

In the present invention, water repellency can be improved by further using a hydrocarbon resin in combination with the waxes and the olefin-maleic anhydride derivative described above. As the hydrocarbon resin, a molecular weight of 500 to 500 obtained by polymerizing an aromatic hydrocarbon having a carbon number of 9 or an aliphatic hydrocarbon fraction having a carbon number of 5 obtained in the process of petroleum refining or petrochemical industry with a Friedel-Crafts catalyst is used. 3000 coumarone-indene resin, terpene resin with a molecular weight of 500-3000 obtained from turpentine oil,
Examples include rosin, ethylene, propylene, butene, isobutylene, oligomers of styrene, and asphalt having a molecular weight of 500 to 3000 and a melting point of 95 ° C or higher.

Hydrocarbon resin is wax: hydrocarbon resin weight ratio is 10
It is used in the range of 0: 0 to 30:70. If an extremely large amount of hydrocarbon resin is used, the water repellency of waxes may be impaired, and the cost of raw materials may be increased.

Specific examples of the water-soluble alkaline compound used in the emulsification include lithium hydroxide, sodium hydroxide, alkali metal hydroxides such as potassium hydroxide, sodium carbonate,
Examples thereof include alkali metal carbonates such as potassium carbonate, ammonia, ammonium hydroxide, amines such as dimethylamine, trimethylamine and triethylamine, and ethanolamines such as triethanolamine, diethanolamine, dimethylethanolamine and methyldiethanolamine. The amount of addition of these alkaline compounds is 0.3 to 3 times the amount required to neutralize the olefin-maleic anhydride derivative.

If the amount added is outside this range, the stability of the emulsion may become poor, which is not preferable.

The above waxes, or the composition ratio of the mixture of waxes and a hydrocarbon resin and the olefin-maleic anhydride derivative is 1: 0.01 to 1: 0.7 by weight ratio, preferably 1: 0.02 to 1: 0.4. To be selected.

Furthermore, by using polyvinyl alcohol in combination with the above emulsion, the stability and water repellency of the emulsion can be further improved. The polyvinyl alcohol preferably has a saponification degree of 70% or more, and usually waxes (or waxes and a hydrocarbon resin) and the total amount of olefin-maleic anhydride derivative: the weight ratio of polyvinyl alcohol is 1: 0.01 to 1: 1. Use in the range of 0.4. Polyvinyl alcohol may be added after the emulsion is formed, or may be added at the time of emulsification.

Further, if necessary, a water-soluble polymer such as polyacrylamide, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like can coexist.

Examples of the method for producing emulsion of the water repellent component in the present invention include phase inversion emulsification method and mechanical emulsification method, and these methods may be used alone or in combination. The mechanical emulsification method includes a homomixer, a valve homogenizer, a colloid mill, an ultrasonic method and the like, but any method can be used as long as it can produce a uniform emulsion.

The composition of the present invention contains the water repellent component prepared as described above and gypsum. Β is often used for industrial purposes as plaster
Any of gypsum, α-semi-water and type 2 anhydrous gypsum can be used. Further, if necessary, lightweight aggregates such as perlite and vermiyukilite, various foaming agents, water reducing agents for gypsum, gypsum setting rate regulators, reinforcing fibers and the like may be used in combination.

In order to produce the composition of the present invention, the emulsion prepared as described above is added to an aqueous slurry containing gypsum, and after curing, dried if necessary. The emulsion in the present invention has a solid content of usually 0.5 to 20 with respect to 100 parts of calcined gypsum.
Parts by weight, preferably 0.7 to 10 parts by weight are added. If the solid content is less than the above range, a sufficient effect cannot be achieved, and if it is more than the above range, the fire resistance and economy, which are the characteristics of the gypsum composition, are lost, which is not preferable.

Next, the present invention will be described more specifically with reference to Examples, Comparative Examples and Production Examples. In the following examples, "part" and "%" mean "part by weight" and "% by weight", respectively.

[A] Production of Olefin-Maleic Anhydride Derivative Production Example A-1 1200 g of α-olefin having 30 to 60 carbon atoms (number average carbon number 48; product of Mitsubishi Kasei Kogyo Co., Ltd., product name Dialene 30) was charged into a flask. , After thoroughly replacing the system with nitrogen gas 18
The mixture was heated to 5 ° C., and 180 g of maleic anhydride and 45.5 g of di-t-butyl peroxide were simultaneously supplied to the mixture for 2 hours to carry out polymerization. After further aging for 1 hour, the mixture was cooled to obtain an olefin-maleic anhydride copolymer (copolymer A) having a maleic anhydride content of 0.725 mmol / g.

Production Example A-2 560 g of olefin (diisobutylene) having 8 carbon atoms and 196 g of maleic anhydride were placed in a flask, the system was sufficiently replaced with nitrogen gas, and the mixture was heated to 80 to 100 ° C. and t-butylperocto under stirring. 73.3 g of an ate was fed and polymerized over 2 hours. After further aging for 1 hour, the mixture was cooled, and the polymer obtained was dried to obtain an olefin-maleic anhydride copolymer (copolymer B) having a maleic anhydride content of 2.6 mmol / g.

Production Example A-3 α-olefin having 6 carbon atoms (product of Mitsubishi Kasei Co., Ltd.,
An autoclave was charged with 420 g of the product name Dialene 6) and 196 g of maleic anhydride, and an olefin-maleic anhydride copolymer was obtained in the same manner as in Production Example A-2. Methanol
96 g was added, and the mixture was reacted at 60 ° C. for 3 hours to obtain a partial ester (copolymer C) of an olefin-maleic anhydride copolymer having a maleic anhydride content of 2.25 mmol / g.

Production Example A-4 C 12 olefin (main component, 2,4,6-trimethyl-
1-Nonene) (484 g) and maleic anhydride (311 g) were charged into an autoclave, the system was sufficiently replaced with nitrogen gas, and the mixture was heated to 200 ° C. with stirring and reacted at the same temperature for 8 hours. Then, unreacted olein and maleic anhydride were distilled off while gradually increasing the degree of reduced pressure, and an olefin-maleic anhydride adduct (adduct D) having a maleic anhydride content of 1.34 mmol / g.
Got

[B] Production of emulsion Production example B-1 95 parts of paraffin wax having a melting point of 68.3 ° C., 5 parts of copolymer A and 122.2 parts of warm water are heated and melted at 85 ° C., 0.4 parts of potassium hydroxide is added, and emulsified by a homomixer. did. Further, the mixture was applied to a piston type high-pressure homogenizer and homogenized at a pressure of 250 kg / cm ² and then cooled to obtain paraffin emulsion A having a solid content of 45%.

Production Example B-2 Paraffin emulsion B was obtained in the same manner as in Production Example B-1 except that Copolymer B and 1.5 parts of potassium hydroxide were used.

Production Example B-3 Paraffin emulsion C was produced in the same manner as in Production Example B-1 except that Copolymer C was used and 0.6 part of potassium hydroxide was used.
Got

Production Example B-4 Paraffin emulsion D was produced in the same manner as in Production Example B-1 except that 0.75 part of potassium hydroxide was used as the adduct D.
Got

Production Example B-5 76.4 parts of paraffin wax having a melting point of 68.3 ° C and a melting point of 97 ° C
19.1 parts of brominated 31.2 petroleum resin was melted at 120 ° C, then the temperature of the system was lowered to 98 ° C, copolymer B1.94 parts, hot water of 98 ° C 1
22 parts, potassium hydroxide 0.52 parts, and saponification degree 97%, 25 ° C
Paraffin emulsion F was obtained in the same manner as in Production Example B-1 by adding 2.5 parts by weight of polyvinyl alcohol (10% aqueous solution) having a viscosity of 5 centipoise of 4% aqueous solution in the above.

Production Example B-6 Paraffin emulsion C obtained in Production Example B-3,
The same polyvinyl alcohol (20% aqueous solution) used in Production Example B-5 was added to the paraffin wax and the copolymer C in the emulsion at a weight ratio of 0.2 to obtain a solid content of about 0.5%. 37% paraffin emulsion C'was obtained.

Production Example B-7 The same polyvinyl alcohol (20% aqueous solution) as used in Production Example B-5 was added to the paraffin emulsion A obtained in Production Example B-1, and the paraffin wax and the copolymer A in the above emulsion were used. To a paraffin emulsion A'having a solid content of about 42% by weight.

Production Example B-8 The same polyvinyl alcohol (20% aqueous solution) as used in Production Example B-5 was added to the paraffin emulsion B obtained in Production Example B-2, and the paraffin wax and the copolymer B in the above emulsion were used. To a paraffin emulsion B'having a solid content of about 42% by adding it in a weight ratio of 0.05.

Production Example B-9 For the paraffin emulsion D obtained in Production Example B-4, the same polyvinyl alcohol (20% aqueous solution) used in Production Example B-5 was added to the paraffin wax and the adduct D in the above emulsion. On the other hand, a paraffin emulsion D'having a solid content of about 42% was obtained by adding it in a weight ratio of 0.05.

Comparative Production Example 1 According to Example 1 of JP-A-60-14932, emulsion a was obtained by the following formulation in the same manner as in this example.

Melting point 130 ° F of paraffin 49.5 parts C ₂₀ ~ ₂₈ alpha-olefin (Mitsubishi Kasei Corporation product,
Butyric acid adduct of product name Dialene 208 (mp.47 ℃ acid value 610.
5 parts Caustic potassium 0.03 part (neutralization equivalent) warm water 50 parts Comparative Production Example 2 According to Example 4 of JP-B-58-58304, emulsion b was obtained by the following formulation in the same manner as in this example.

Petroleum resin having a softening point of 120 ° C. and a bromine number of 30 71 parts Paraffin having a melting point of 145 ° F 259 parts Aluminum stearate 40 parts 6% aqueous solution of potassium salt of styrene maleic anhydride monomethyl ester 678 parts Comparative Production Example 3 According to the method described in Sho 55-37423, 95 parts of paraffin having a melting point of 60 ° C, 5 parts of maleic anhydride-modified wax having an acid value of 65 and a softening point of 111 ° C are melted at 130 ° C, and this is heated in a pressure vessel. 122.2 parts and 0.3 part of caustic potash were added and emulsified. At the same temperature, emulsion c was obtained in the same manner as in Production Example B-1.

Example 1 Production example B was added to β hemihydrate gypsum (Sakura Mark A grade, Yoshino Gypsum Co., Ltd.)
-1 to B-4, B-6 to B-9, and the paraffin emulsion obtained in Comparative Production Examples 1 and 3 were used as gypsum 10 in terms of solid content.
To 1.0 part, 1.0 part and 80 parts of water were added to form a slurry,
This was poured between base papers for gypsum board to form a gypsum board, and dried at 70 ° C for about 2.5 hours.

The specific gravity of the obtained board was about 0.95.

Water absorption rate (A _W ) after immersion in water at 20 ℃ ± 1 ℃ for 24 hours
Was measured.

The results are shown in Table 1.

Example 2 Production example B was added to β hemihydrate gypsum (Sakura Mark A grade, Yoshino Gypsum Co., Ltd.)
-6 and 1.0 parts of the paraffin emulsion obtained in Comparative Production Example 2 was added to 100 parts of gypsum as a solid content, and further 2 parts of gypsum dihydrate, 80 parts of water as a setting accelerator and the specific gravity of the obtained gypsum board were Add 0.01 to 0.0 of foaming agent to about 0.75 to 0.8.
A gypsum board was obtained in the same manner as in Example 1 with the addition of 2%.

The water absorption rate of this board after 2 hours was measured in the same manner as in Example 1. The results are shown in Table 2.

Further, in order to examine the fluidity of gypsum, a slurry obtained by adding 1.5 parts of emulgion in a solid content and 80 parts of water to 100 parts of the above-mentioned gypsum, a truncated cone having no bottom installed on a glass plate. Molded container (lower inner diameter 50mm, upper inner diameter 35mm, height 30m
m) immediately, scrape off the excess slurry overflowing on the top with a metal spatula, then gradually pull up the container vertically upward to remove it, and remove the maximum diameter of the gypsum slurry spread on the glass plate. The measured value was used as the flow value. The results are also shown in Table-2.

Example 3 The gypsum used in the gypsum board in Japan is drainage gypsum,
In many cases, the slurry is acidic, such as gypsum by-product of phosphoric acid.
Therefore, in order to investigate the stability of the water repellent against these, one drop of each paraffin emulsion, dropped into a saturated gypsum aqueous solution of pH 5, visually observe the stability, ○ those that are uniformly dispersed, Dispersed but aggregates occur △,
The results are shown in Tables 1 and 2.

〔The invention's effect〕

The gypsum composition of the present invention has (1) higher water resistance than that using a conventional water repellent, and (2) compared with the case of using a conventional water repellent, an acidic gypsum composition When used, it exhibits better workability, and (3) the fluidity of the slurry is better than when a conventional water repellent is used, and accordingly, the amount of mixed water can be reduced and the line speed can be increased.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location // C04B 111: 27 (72) Inventor Kiyoharu Yoshimi Sanjo, 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Kasei Kogyo Co., Ltd. Research Institute (72) Inventor Yasuji Ozawa 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. Research Institute (56) Reference JP-A-55-37423 (JP, A) )

Claims (8)

[Claims] 1. An emulsion obtained by emulsifying (A) a wax having a melting point of 40 to 90 ° C. and (B) an olefin-maleic anhydride derivative in water in the presence of (C) a water-soluble alkaline compound (F). A water-repellent gypsum composition comprising an emulsion containing polyvinyl alcohol and (D) gypsum. 2. An emulsion comprising (A) waxes having a melting point of 40 to 90 ° C., (B) an olefin-maleic anhydride derivative and (E) a hydrocarbon resin in water in the presence of (C) a water-soluble alkaline compound. The composition according to claim 1, which is obtained by adding (F) polyvinyl alcohol to an emulsified emulsion. 3. The olephine-maleic anhydride derivative is an adduct or copolymer of α-olefin having 4 to 60 carbon atoms and maleic anhydride, and a partial ester thereof. The composition according to the item. 4. A composition according to claim 2, wherein the hydrocarbon resin is petroleum resin, coumarone-indene resin, terpene resin, rosin, low molecular weight polyolefins or asphalt. 5. The weight ratio of (A) to (B) is 1: 0.01 to 1: 0.
The composition according to claim 1 or 2, which is 7. 6. The composition according to claim 2, wherein the weight ratio of the total amount of (A) and (E) to (B) is 1: 0.01 to 1: 0.7. 7. The composition according to claim 1, wherein the weight ratio of the total amount of (A) and (B) to (F) is 1: 0.01 to 1: 0.4. 8. The composition according to claim 2, wherein the weight ratio of the total amount of (A), (B) and (E) to (F) is 1: 0.01 to 1: 0.4.