JPH01246166A - Additive for cement - Google Patents

Abstract

PURPOSE:To obtain an additive capable of improving dispersibility of cement particles in a cement compound by subjecting a copolymer mixture of a specific hydrocarbon mixture with an unsaturated carboxylic acid to neutralization treatment. CONSTITUTION:An additive for cement containing a neutralization treatment product of a copolymer mixture of a 5-10C hydrocarbon mixture obtained by distillation treatment of residual oil produced in thermal cracking of a hydrocarbon with an unsaturated carboxylic acid or anhydride thereof as an active component. Naphtha, kerosene or mixture thereof which are petroleum fractions, obtained by distilling crude oil and having 30-350 deg.C boiling point are preferred as the hydrocarbon used. Either of light and heavy naphthas may be used as the naphtha. Maleic acid, acrylic acid methacrylic acid, etc., are cited as the unsaturated carboxylic acid. Dispersibility of cement particles in cement compounds can be improved by adding the above-mentioned additive for cement and moderate fluidity can be imparted. Duration time of fluidity thereof can be simultaneously prolonged.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an additive for cement, and more specifically,
For cement that improves the dispersibility of cement particles in cement mixtures such as cement paste, mortar, or concrete, improves the fluidity of cement mixtures, and suppresses the decline in fluidity over time to improve workability. Regarding additives.

[Prior art] In cement mixtures such as cement paste, mortar, or concrete, the cohesive force of cement particles is strong, so that a cement mixture with good workability can be obtained with the unit amount of water required to harden the cement. I can't. Therefore, in order to improve the workability of cement mixtures, it is necessary to increase the unit amount of water. However, increasing the unit amount of water causes a decrease in strength, so in order to obtain the same strength, the unit amount of cement must be increased. However, when the unit amount of cement is increased, the curing calorific value increases, which causes the problem that cracks are more likely to occur.

Further, after mixing the various materials, cement mixtures are often transported to the pouring site by mixer trucks, etc., but the time required for transportation tends to vary depending on the distance of transportation, the degree of traffic congestion, etc. Because of this, the fluidity of the cement mixture differs at the pouring site, making it difficult to obtain consistent workability. Furthermore, when pumping a cement mixture using a pump, if the pumping is interrupted for some reason and then restarted, the fluidity of the cement mixture in the piping has decreased, so the pumping pressure after restarting is There were problems such as having to raise the pipes or partially blocking the pipes.

As mentioned above, the most convenient way to improve the fluidity of a concrete mixture is to increase the amount of water mixed, but increasing the amount of water causes cracks and spalling after construction. Therefore, there is a need for an additive that has a water-reducing effect, improves the dispersibility of cement particles, provides suitable fluidity, and is capable of sustaining this fluidity.

Conventionally, salts of copolymers of styrene, methyl acrylate, and maleic acid have been known as such additives (
(Japanese Unexamined Patent Publication No. 62-187151).

[Problem to be Solved by the Invention] This conventional cement additive is used alone or in combination with other cement additives to entrain the right amount of air into the cement mixture to improve the quality of the cement mixture. Although it has the characteristic of providing a hardened product, it lacks uniform dispersibility in cement mixtures, and therefore has not always been at a satisfactory level in terms of contributing to improving the fluidity of cement mixtures. Furthermore, the fluidity was not maintained sufficiently.

[Means for Solving the Problems 1] Therefore, the inventors created a cement mixture that has sufficient fluidity, suppresses the decline in fluidity over time, and entrains an appropriate amount of air to achieve high quality. As a result of intensive research to develop a cement additive that produces a hardened product,
It has been discovered that the above object can be achieved by using a neutralized specific copolymer mixture or a specific sulfonated copolymer mixture, and based on this knowledge, the present invention has been made. I was able to complete it.

That is, according to the present invention, a copolymer mixture of a hydrocarbon mixture having 5 to io carbon atoms and an unsaturated carboxylic acid or its anhydride obtained by distilling the residual oil obtained when hydrocarbons are thermally decomposed. A cement additive containing as an active ingredient a neutralized product, or a sulfonated and neutralized copolymer mixture, and a cement additive consisting of two or more types, one of which is A cement additive is provided which is obtained by neutralizing or sulfonating the copolymer mixture.

The hydrocarbon used in this invention is not particularly limited, but naphtha, kerosene, light oil, or a mixture thereof is preferable, and these have a boiling point of 30 to 3, obtained by distillation of crude oil.
It is a petroleum fraction at 50°C, and naphtha may be either light naphtha or heavy naphtha.

In this invention, first, the above-mentioned hydrocarbons are thermally decomposed to obtain a residual oil, and this residual oil is subjected to distillation treatment to obtain a hydrocarbon mixture having 5 to 10 carbon atoms. For this thermal decomposition, the temperature is 200
~1200℃, preferably 400-10000G! , pressure 0-100 kg7 cm2, preferably 0.5-5
Pyrolyzed at 0 kg/cm2 or silica,
Catalytic cracking is carried out under the same conditions as above in the presence of a catalyst such as alumina, silica/alumina, zeolite, platinum, or palladium. In this way, a residual oil (pyrolysis gasoline, TCG) is obtained. Next, the obtained residual oil is distilled by a conventional method to reduce the number of carbon atoms from 5 to 10. Specific gravity 0.9
400-0.9750 and a boiling point of 30-250°C. An example of the composition of the obtained hydrocarbon mixture is shown in Table 1.

In this invention, the hydrocarbon mixture having 5 to 10 carbon atoms obtained above is subjected to a polymerization reaction with an unsaturated carboxylic acid or its anhydride to form a copolymer mixture, and this copolymer mixture is mixed with sodium, potassium, calcium, etc. hydroxide, carbonate,
Treatment by neutralizing using a neutralizing agent such as bicarbonate, ammonia, or amine at a temperature of 30-100°C, preferably 50-90°C, for 0.5-5 hours, preferably 1-3 hours. This product is used as an additive for cement.

(Hereinafter, blank space) In addition, in this invention, the carbon number 5 to
The hydrocarbon mixture of No. 10 is polymerized with an unsaturated carboxylic acid or its anhydride to form a copolymer mixture, and this copolymer mixture is sulfonated and then neutralized, and this is used as a cement additive. [Use.

Examples of the unsaturated carboxylic acid used in these cases include maleic acid, acrylic acid, and methacrylic acid.

In the copolymer reaction, 0.1 to 60 parts by weight, preferably 3 to 40 parts by weight of an unsaturated carboxylic acid or its anhydride is added per 100 parts by weight of the hydrocarbon mixture having 5 to 10 carbon atoms, and the temperature is 70 to 70 parts by weight. 250°C1 preferably 130~
The polymerization reaction is carried out at 190°C for 0.5 to 10 hours, preferably 1 to 5 hours. Also, at this time, benzene,
Toluene, xylene, petroleum aromatic solvents (boiling range 14
(0 to 230℃), ascent, methyl ethyl Kent, carbon tetrachloride, etc., or azobisisobutyronitrile, benzoyl peroxide, tertiary butylcumyl peroxide, di-tertiary bunal peroxide, Organic peroxides can also be used as polymerization initiators. In this way, a number average molecular weight of 100 to 30,00
A copolymer mixture with an acid value of 70-600 m9KOH/g is obtained.

For sulfonation, the obtained copolymer mixture 10
Per 0 parts by weight, 10 to 500 parts by weight, preferably 20 to 300 parts by weight of a sulfonating agent such as sulfuric acid, oleum, chlorosulfuric acid, sulfuric anhydride is added, and the temperature is 0 to 150°C, preferably 30 to 130°C. By reacting for 0.1 to 10 hours, preferably 0.5 to 5 hours, a sulfonated copolymer mixture is obtained.

The conditions for neutralizing the sulfonated copolymer thus obtained are as described above.

As mentioned above, the cement additive of the present invention is a combination of a hydrocarbon mixture having 5 to 10 carbon atoms obtained by distilling the residual oil obtained when hydrocarbons are thermally decomposed, and an unsaturated carboxylic acid or its anhydride. The active ingredient is a neutralized copolymer mixture, or a sulfonated and neutralized copolymer mixture, but when each of these cement additives is used alone. Although these methods sufficiently contribute to maintaining the fluidity of cement mixtures, there still remain some problems in improving the fluidity.

Therefore, an attempt was made to use these cement additives in combination with conventionally known cement additives, and it was found that satisfactory fluidity could be imparted and maintained. The present invention also provides an additive for cement comprising a combination of two or more types.

Such conventional cement additives include salts of formalin condensates of naphthalenesulfonic acids, salts of formalin condensates of alkylnaphthalenesulfonic acids, salts of formalin condensates of naphthalenesulfonic acids and alkylnaphthalenesulfonic acids, and lignin. Salts of sulfonic acids, salts of formalin condensates of naphthalenesulfonic acid and ligninsulfonic acids, sulfonated products of formalin condensates of melamine, salts of sulfonated styrene-maleic acid copolymers, formalin condensates of sulfonated creosote oils salt,
Examples include formalin condensates of sulfonated heavy aromatic hydrocarbon oils and salts of styrene-methyl acrylate-maleic acid copolymers.

There is no particular restriction on the blending ratio of each of these components, and they can be blended in various ratios, but usually 10% of the salt of the copolymer is used.
0 parts by weight, 5 to 9 parts of conventionally known cement additives
00 parts by weight, preferably 20 to 500 parts by weight.

The cement additive of the present invention is added to cement mixtures such as cement paste consisting of cement and water; mortar consisting of cement, sand and water; and concrete consisting of cement, sand, pebbles and water. The amount of the cement additive of the present invention added to the cement mixture is not particularly limited, but is 0.01 to 1.0 in terms of solid content relative to the cement.
Weight %, preferably 0.05 to 0.5 weight %, is suitable.

In addition, in addition to the cement additive of the present invention, other known water reducing agents--4 retarders, hardening accelerators, air entraining agents,
Air entrainment water reducing agents and other auxiliary ingredients may be added as appropriate.

[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Production Example: 100 parts by weight of paracymene was placed in a flask equipped with a stirrer, a dropping funnel, a reflux condenser, and a thermometer, and the inside was heated to 170% by weight.
The residual oil (
A hydrocarbon mixture having 5 to 10 carbon atoms obtained by distilling pyrolysis gasoline (TCG) (the composition is shown in Table 2).
100 parts by weight, unsaturated carboxylic acid or its anhydride shown in Table 3 and 0.0 parts by weight of di-tert-butyl peroxide.
7 parts by weight of the mixed solution was added dropwise through the dropping funnel over 2 hours while stirring. After the dropwise addition, the polymerization reaction was further carried out for 1 hour while stirring to obtain a yellow transparent solid copolymer mixture.

Table 3 shows the number average molecular weight and acid value of the obtained copolymer mixture.

Next, 10% by weight was added to 50 parts by weight of these copolymer mixtures.
104 g and 859 g of sulfur and lithium hydroxide aqueous solutions, respectively.
80 g of the sodium salt was added and neutralized at 90° C. for 3 hours to obtain a sodium salt, which was made into a 30% by weight aqueous solution to obtain cement additives (A), (B) and (C).

On the other hand, separately obtained cement additive (A) 50
150 parts by weight of concentrated sulfuric acid was added as a sulfonating agent to the weight part, and sulfonation was carried out at 100°C for 2 hours to obtain a sulfonated copolymer mixture.

These sulfonated copolymer mixtures contain calcium hydroxide 9
An emulsion containing 59 was added, and the produced calcium sulfate was removed by filtration. To the obtained filtrate, 959% of a 20% by weight aqueous sodium carbonate solution was added and neutralized at 60°C for 1 hour to obtain a sodium salt, and this was made into a 30% by weight aqueous solution to obtain a cement additive (D).

(Left below) Examples 1 to 4 In a 10M capacity forced stirring mortar mixer, cement,
Sand and water were added in the amounts shown in Table 4 and stirred for 2 minutes.

Thereafter, cement additives (A) to (G) shown in Tables 3 and 6 were added and stirred for an additional 30 seconds to prepare a mortar composition.

The mortar composition thus obtained was subjected to the Mortar 70 test and the results are shown in Table 4.

Mortar flow test: Based on JIS R-520i.

Flow values (III=l) immediately after mortar composition preparation, 15.30.45 and 60
Measure changes over time after minutes.

(Leaving space below) Examples 5 to 12 and Comparative Examples 5 to 8 Cement, sand, pebbles, air-entraining water reducer, and water were charged in the amounts shown in Table 5 into a forced kneading mixer having an internal volume of 100Q, and stirred for 1 minute. Thereafter, additives (A) to (G) shown in Tables 3 and 6 were added and further stirred for 30 seconds to prepare a concrete composition.

Each of the concrete compositions thus obtained was subjected to the following evaluation tests, and the results are shown in Table 5.

Air amount (volume %): Based on JIS A-1128.

Slump value (c'm): J Is A-110
Concrete 1 Immediately after composition preparation, 30.6
Measurement of changes over time at 0 and 90 minutes.

Compressive strength (kg/cm”): JISA-
1108, the values were measured 7 days and 28 days after preparation.

(The following is a blank space) Table 6 [Effect of the invention 1 By adding the cement additive of this invention, the dispersibility of cement particles in cement mixtures is improved, and suitable fluidity is imparted, and the fluidity of the cement mixture is improved. It can extend the duration of sex.

Therefore, the workability of pouring the cement mixture is significantly improved. Furthermore, this cement additive has a water-reducing effect, making it possible to obtain mortar and concrete that do not develop cracks and have sufficient strength. Therefore, the cement additive of the present invention is extremely useful in fields such as civil engineering and architecture, and in fields dealing with secondary concrete products.

Claims (1)

[Scope of Claims] 1. A copolymer mixture of a hydrocarbon mixture having 5 to 10 carbon atoms and an unsaturated carboxylic acid or its anhydride obtained by distilling the residual oil obtained when hydrocarbons are thermally decomposed. A cement additive whose active ingredient is a Japanese-treated product. 2. The cement additive according to claim 1, wherein the hydrocarbon is naphtha, kerosene, light oil, or a mixture thereof. 3. An additive for cement comprising, as an active ingredient, the copolymer mixture according to claim 1, which has been sulfonated and then neutralized. 4. The cement additive according to claim 1 or 2, wherein the unsaturated carboxylic acid is maleic acid, acrylic acid or methacrylic acid. 5. A cement additive comprising two or more types, one of which is the cement additive according to claim 1 or 2. 6. The cement additive according to claim 5, wherein the unsaturated carboxylic acid is maleic acid, acrylic acid or methacrylic acid. 7. Additives for cement other than claims 1 and 2 include salts of formalin condensates of naphthalenesulfonic acids, salts of formalin condensates of alkylnaphthalenesulfonic acids, salts of formalin condensates of naphthalenesulfonic acids and alkylnaphthalenesulfonic acids, and lignin. Salts of sulfonic acids, salts of formalin condensates of naphthalenesulfonic acid and ligninsulfonic acids, sulfonated products of formalin condensates of melamine, salts of sulfonated styrene-maleic acid copolymers, formalin condensates of sulfonated creosote oils The cement additive according to claim 5 or 6, wherein the cement additive is at least one selected from a salt of a sulfonated heavy aromatic hydrocarbon oil, a formalin condensate of a sulfonated heavy aromatic hydrocarbon oil, and a salt of a styrene-methyl acrylate-maleic acid copolymer. .