JPH0826811A - Composition for water-repellent cured body and water-repellent cured body - Google Patents

Abstract

(57) [Summary] [Purpose] Not only a water-repellent cured product that is excellent in waterproofness and water repellency at the initial stage of curing and also has good weather resistance under outdoor exposure conditions, and improved workability during manufacturing. An object of the present invention is to provide a composition for a water-repellent cured body. [Structure] For a composition for a hardened body containing a powdery siliceous raw material and a calcareous raw material as main components, the following general formula (1) (However, in the formula, R represents an alkyl group having 4 to 12 carbon atoms, R'represents an alkyl group having 1 to 3 carbon atoms, and y represents all the methyl groups in which the number of the alkyl group R is directly bonded to a silicon atom in one molecule. A silicone oil represented by an integer, z being 1 or 2, and 3 ≦ x + y + z ≦ 20, which is 10 mol% or more of the number of groups, is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-repellent hardened material composition and a water-repellent hardened material which have weather proof water repellency of a hardened material and are particularly suitable for lightweight cellular concrete useful as a building material. .

[0002]

2. Description of the Related Art Conventionally, a composition for a hardened body containing a powdery siliceous raw material and a calcareous raw material as main raw materials has a foaming agent added or not added thereto. A molded and hardened body is manufactured by molding into a predetermined shape and subjecting it to high-pressure steam curing, normal-pressure steam curing or wet curing. The molded and cured product thus obtained is used in a wide range of applications as a heat insulating material, heat insulating material, concrete, mortar, steam pipe, slate and the like.

Particularly, in recent years, in the case of obtaining lightweight cellular concrete, water is added to a crushed material of siliceous materials such as silica sand and silica and calcareous materials such as lime and cement at an appropriate ratio and then mixed with aluminum or the like. After adding metal powder to the mixture and stirring it, or by mixing it with air, the mixture is allowed to contain air bubbles, and then solidified and cured, and cured by high-pressure steam curing, normal-pressure steam curing, or wet curing in the same manner as above. The method has been adopted.

The molded and hardened product produced in this way, particularly lightweight cellular concrete, has a large number of pores on its surface, and the pores present inside are also open pores, so that the water absorbency is high. However, high water absorption is not desirable as a property of lightweight cellular concrete used as a building material. Therefore, in order to prevent the water absorption of the molded and cured product from increasing, it has been proposed to add various silicones during the production thereof.

For example, in JP-A-55-42272, dimethylpolysiloxane, amino group-containing polysiloxane, polyether-containing polysiloxane, olefin-containing polysiloxane, epoxy group-containing polysiloxane, fluorine-containing polysiloxane, α-methyl. Styrene-containing polysiloxane and alcohol-modified polysiloxane, 55-
85452 discloses methylphenylpolysiloxane and chlorophenylmethylpolysiloxane, 55-90.
No. 460 discloses a methyl silicone varnish, a phenylmethyl silicone varnish, and a modified silicone varnish obtained by modifying or blending these with other organic monomers or polymers with an alkyd, an epoxy resin, an acrylic resin, or the like. Is disclosed.

By adding the above various silicones as water repellents, it is possible to prevent the water absorption of the molded and cured products obtained in all cases to a certain extent but to increase the water repellency and waterproofness. As shown. However, since each of the above-mentioned various silicones exhibits strong water repellency, it does not dissolve at all in a slurry obtained by mixing a siliceous raw material, a calcareous raw material and the like with water in producing a molded and cured product, and thus has no hydrophilicity. There is a problem in that it is very difficult to disperse in a slurry.

Therefore, in order to solve the above-mentioned problems, JP-A-57-123851 discloses that dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane or methylcarboxyl-modified polysiloxane is used as an anionic surfactant. A method of emulsifying and adding to a slurry is disclosed. According to this method, it is easy to add silicone to the slurry, but since the surfactant having strong hydrophilicity is used together, the waterproofness and water repellency of the molded and cured product are considerably impaired. There was a problem.

Further, according to the study of the present invention, by adding the above-mentioned various water repellents, the molded and cured product exhibits good waterproofness and water repellency in the initial stage of curing, but it is compared with the case where it is exposed to the outdoors. It has been found that there is a problem that these characteristics disappear or deteriorate easily.

Further, Japanese Patent Publication No. 1-44733 discloses:
In producing a molded and cured product, the average number of organic groups per silicon atom is 0.4 to 1.8, at least 10% of which has an alkyl group having 4 or more carbon atoms, and a silicon atom. It is disclosed that an organopolysiloxane having an average of 0.01 to 2.0 alkoxy groups per one is added as a water repellent.

The above water repellent has weather resistance within a certain range, and the dispersibility of the slurry is improved due to the presence of a hydrophilic alkoxy group, but the content of the alkoxy group is large. Therefore, new problems such as alcohol being liberated in an alkaline slurry and contaminating the working environment have been found. Furthermore, since the number of organic groups exhibiting the most water repellency is as small as 0.4 to 1.8 on average, the number of organic groups is 2.0 or more on average as compared with the silicone oil type, There was also a problem that the addition amount had to be increased.

On the other hand, Japanese Patent Publication No. 1-58148 discloses that
In order to solve the above-mentioned problem, it has an alkyl group having 4 to 12 carbon atoms and the total number of siloxane units in one molecule is 2 to 2.
A method for producing a water-repellent molded and cured product by adding a silicone oil containing no alkoxy groups within the range of 0 is disclosed. According to this method, it is possible to produce a water-repellent molded and cured product which is excellent in waterproofness and water repellency at the initial stage of curing and also has good weather resistance under outdoor exposure conditions (that is, durability of water repellency). However, the above silicone oil has not been improved in dispersibility in a slurry at the time of production, and unless very careful work is performed, the silicone oil becomes a water-repellent molded and cured product having uneven distribution, and its waterproofness and water repellency. Had the problem that the effect of was reduced.

The present invention has been made in view of the above circumstances, and not only provides a water-repellent cured product which is excellent in waterproofness and water repellency at the initial stage of curing and also has good weather resistance under outdoor exposure conditions. It is an object of the present invention to provide a composition for a water-repellent cured product and a water-repellent cured product with improved workability during production.

[0013]

MEANS TO SOLVE THE PROBLEMS As a result of intensive studies to achieve the above object, the present inventor has found that a composition for a water-repellent cured body containing a powdery siliceous raw material and a calcareous raw material as main raw materials. On the other hand, by adding a silicone oil having a specific range of alkyl groups, a specific range of polymerization degree, and a specific range of hydrophilic alkoxy groups for improving dispersibility in the slurry, workability during production is improved. The inventors have found that a water-repellent cured product that is improved and has excellent weather resistance can be obtained, and completed the present invention.

That is, according to the present invention, a silicone oil represented by the following general formula (1) is preferably added to a composition for a hardened product containing a powdery siliceous raw material and a calcareous raw material as main components. The composition for water-repellent cured products is characterized in that the composition is added in an amount of 0.05 to 3% by weight, and a water-repellent cured product containing the silicone oil of the formula (1) as a water repellent. With the goal.

[0015]

Embedded image (However, in the formula, R represents an alkyl group having 4 to 12 carbon atoms, R'represents an alkyl group having 1 to 3 carbon atoms, and y represents all the methyl groups in which the number of the alkyl group R is directly bonded to a silicon atom in one molecule. (An integer, z is 1 or 2, and 3 ≦ x + y + z ≦ 20 to be 10 mol% or more of the number of groups.)

The present invention will be described in more detail below. The composition for water-repellent cured product of the present invention uses a siliceous raw material and a calcareous raw material as main raw materials. These main raw materials are molded and cured. The type is not particularly limited as long as it is generally used for body production. The siliceous raw material may be any material containing a SiO ₂ unit as a main component, and examples thereof include silica, sand, silica stone, silica sand, blast furnace slag, and fly ash.
As the calcareous raw material, any material containing a CaO unit as a main component may be used, and examples thereof include quick lime, limestone, slaked lime, cement and calcium carbonate.

Since the blending ratio of the siliceous raw material and the calcareous raw material described above greatly varies depending on the use of the molded and hardened product,
Although not particularly limited, it is usually 3 as a weight ratio.
It is 0:70 to 70:30.

The specific silicone oil used in the present invention is represented by the following general formula (1).

[0019]

Embedded image

Here, R is a long-chain alkyl group having 4 to 12 carbon atoms, preferably 6 to 10 carbon atoms.
When the carbon number of R is less than 4, the weather resistance is not sufficient, and when the carbon number of R is greater than 12, the water repellency tends to decrease. In addition, R in one molecule may be the same or different.

In addition, y representing the number of groups of R in one molecule
Is one of all methyl groups that directly connects the number of long-chain alkyl groups R in silicone oil to silicon atoms in silicone oil.
An integer of 0 mol% or more, preferably 20 mol% or more,
More preferably, it is an integer of 20 to 80 mol%. This improves the weather resistance of the water-repellent cured product produced by the present invention.

R'is an alkyl group having 1 to 3 carbon atoms. The reason why the number of carbon atoms of R'is set to 1 to 3 is to impart hydrophilicity as an alkoxy group (OR '), and an alkoxy group having 4 or more carbon atoms tends to have reduced hydrophilicity.
Z representing the number of groups in one molecule of this alkoxy group is 1 or 2
Is. When the number of alkoxy groups in one molecule of silicone oil is 3 or more, the water repellency of the obtained cured product is adversely affected.

The total number of siloxane units (x + y + z) of the silicone oil of formula (1) is 3-20. If the total number of siloxane units exceeds 20, the viscosity of the silicone oil will increase excessively, and it will be difficult to uniformly disperse the alkoxy groups when they are mixed with the slurry, even though the alkoxy groups exhibit hydrophilicity.

Specific examples of such silicone oils include the following compounds.

[0025]

[Chemical 4]

The above silicone oil is used in an amount of 0.05 to 3 with respect to the above main raw materials (silicic raw material and calcareous raw material).
%, Preferably 0.3 to 2% by weight. If it is less than 0.05% by weight, a cured product having sufficient water repellency cannot be obtained, and if it exceeds 3% by weight, further water repellency cannot be obtained, which is economically disadvantageous.

The composition of the present invention contains at least one of the above-mentioned silicone oils. However, two or more kinds of the above-mentioned silicone oils may be added in combination,
The above silicone oil and other silicone oils can be added in combination.

As a general method for synthesizing the silicone oil of the above formula (1), for example, CH ₂ ═CH (CH ₂ ) ₅ CH ₃ is added to organopolysiloxane having a specific SiH group.
Such a long-chain alkene having 4 to 12 carbon atoms is subjected to an addition reaction to synthesize a silicone oil in which one or more SiH groups remain in one molecule. Here, a long chain alkene was added to the organopolysiloxane having a SiH group at a reaction rate of 10
It is very difficult to add so that the reaction rate becomes 0%, but it is easy to add so that the reaction rate becomes about 90%. In this way, a method in which an appropriate amount of an alcohol having 1 to 3 carbon atoms is added to the silicone oil in which the SiH group remains and an alkoxy group is introduced by a dehydrogenation reaction can be mentioned. According to this method, the silicone oil of the above formula (1) can be easily produced. As a catalyst for the above addition reaction and dehydrogenation reaction, a platinum compound such as chloroplatinic acid is generally used as a common catalyst.

In addition to the above-mentioned main raw materials of siliceous raw material and calcareous raw material, various components can be added to the composition of the present invention as required. Examples of such components include glass fiber. , Synthetic fibers, reinforcing materials such as pulp, wood chips,
Mineral oil, a hardening accelerator, etc. are mentioned.

When a molded and cured product is obtained using the composition of the present invention, this composition is used in the form of a slurry by adding water, and this is poured into a mold and molded and cured to obtain a water repellent cured product. It is a thing. In particular, the composition of the present invention is suitably applied to the production of lightweight cellular concrete having a density of, for example, 150 to 800 kg / m ³ , and especially 150
It is more suitable for lightweight aerated concrete by steam curing having a density of ˜450 kg / m ³ .

[0031]

EFFECTS OF THE INVENTION According to the composition for a water-repellent cured product of the present invention, workability during production is improved, water resistance and water repellency at the initial stage of curing are excellent, and weather resistance under outdoor exposure conditions is also good. A water-repellent cured product can be easily produced. Since this cured product contains and disperses the silicone oil of the formula (1), a water-repellent cured product suitable as, for example, lightweight cellular concrete for building materials can be obtained. .

[0032]

EXAMPLES Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] 50 parts of fine sand having a silica content of 70 to 80% (parts by weight, the same applies hereinafter), 28 parts of Portland cement, 12 parts of fine powder quicklime having a calcium oxide content of 88 to 92%, and aluminum powder 60 parts of water is added to 1 part to make a slurry, and the organopolysiloxane A represented by the following formula (2) is used as a silicone oil in the slurry.
(Viscosity: 20 cst; 25 ° C., the same shall apply hereinafter) was added at a ratio shown in Table 1 to the total solid amount in the slurry to obtain a composition, which was poured into a mold and kept in an autoclave at 10 atm for 10 hours. 12 in air after steam curing
It dried at 0 degreeC for 3 hours, and obtained the hardened | cured material.

[Examples 2 and 3] Except that the amount of organopolysiloxane A added in Example 1 was changed to the amount shown in Table 1,
A cured product was obtained in the same manner as in Example 1.

[Comparative Examples 1 to 3] The silicone oil of Example 1 was changed to the organopolysiloxane B represented by the following formula (3) (viscosity: 23 cst), and the addition amount was changed to the amount shown in Table 1. A cured product was obtained in the same manner as in Example 1.

[Comparative Examples 4 to 6] The silicone oil of Example 1 was changed to organopolysiloxane C (viscosity: 20 cst) represented by the following formula (4), and the addition amount was changed to the amount shown in Table 1. A cured product was obtained in the same manner as in Example 1.

[0037]

Embedded image

The specific gravity of each cured product of Examples 1 to 3 and Comparative Examples 1 to 6 was 0.40 to 0.45 g / cm ³ .

Each cured product was cut into pieces of 10 × 10 × 3 (cm), and water drops were observed by dropping water droplets at three points on the surface thereof. Each water repellency was evaluated according to the following criteria.

⊚: Water droplets were kept spherical even after 30 minutes, and the water repellency was very good. ◯: After 30 minutes, the water droplets become hemispherical and the water repellency is good. Δ: Water droplets disintegrate after 10 minutes, but did not reach below the surface and the water repellency was slightly good. X: Water droplets are absorbed below the surface after 5 minutes and water repellency is poor. XX: Water droplets are immediately absorbed under the surface and show no water repellency. Table 1 also shows the evaluation results of the water repellency of each cured product.

[0041]

[Table 1]

From the results shown in Table 1, it is recognized that the cured product obtained from the composition of the present invention continues to have good water repellency even when the amount of silicone oil added is small. On the other hand, when the organopolysiloxane B having a long-chain alkyl group but not containing an alkoxy group is used as in the silicone oil of the present invention (Comparative Examples 1 to 3), the addition amount of the silicone oil is small. It is recognized that the water repellency is lowered and the water repellency is not sustained. Also,
When the organopolysiloxane C containing no long-chain alkyl group and alkoxy group is used (Comparative Examples 4 to 6),
The water repellency at the initial stage of curing is slightly inferior, but there is a large difference in the persistence of water repellency.

Example 4 32 parts of fine silica powder having a silica content of 85%, Portland cement 22 parts, powder quicklime 6 parts and aluminum powder 0.5 part were added with 40 parts of water to form a slurry. Organopolysiloxane D represented by the following formula (5) as silicone oil
(Viscosity: 40 cst) was added at a ratio shown in Table 2 with respect to the total solid amount in the slurry, and the mixture was further stirred, and then light-weight cellular concrete by steam curing was manufactured according to a normal operation.

[Examples 5 and 6] Except that the addition amount of the organopolysiloxane D of Example 4 was changed to the amount shown in Table 2,
A cured product was obtained in the same manner as in Example 4.

[Comparative Examples 7 to 9] The silicone oil of Example 4 was changed to organopolysiloxane E (viscosity: 40 cst) represented by the following formula (6), and the addition amount was changed to the amount shown in Table 2. A cured product was obtained in the same manner as in Example 4.

Comparative Examples 10 to 12 The silicone oil of Example 4 was changed to the organopolysiloxane F (viscosity: 40 cst) represented by the following formula (7), and the addition amount was changed to the amount shown in Table 2. A cured product was obtained in the same manner as in Example 4.

[0047]

[Chemical 6]

The density of each of the obtained lightweight cellular concretes was 280 to 300 kg / m ³ .

The water repellency of each lightweight cellular concrete was evaluated in the same manner as above, and the results are also shown in Table 2.

[0050]

[Table 2]

From the results shown in Table 2, the lightweight cellular concrete produced by the method of the present invention has good water repellency even when the amount of silicone oil added is small, and the water repellency is maintained even under the exposure condition. Is recognized. On the other hand, when organopolysiloxane E having a long-chain alkyl group and not containing an alkoxy group was used (Comparative Example 7 to
In 9), it is recognized that when the added amount of silicone oil is small, the water repellency is reduced and the water repellency does not last under the exposure conditions. Further, an organopolysiloxane F having an aryl group and not containing a long-chain alkyl group or an alkoxy group
In the case of using (Comparative Examples 10 to 12), the water repellency in the initial stage of curing is slightly inferior, but a large difference is observed particularly in the persistence of water repellency.

Therefore, from the above results, it was confirmed that the composition of the present invention is suitable for lightweight aerated concrete by steam curing.

Reference Example One example of the silicone oil used in the composition of the present invention is obtained by the following synthesis method.

That is, (CH ₃ ) ₃ SiO [(CH ₃ ) ₂ Si
O] ₆ [CH ₃ · HSiO] ₄ Si (CH ₃ ) ₃ 423 g of SiH group-containing methylpolysiloxane and decene 2
10 g was charged into a 1-liter 4-necked flask equipped with a stirrer, a thermometer, a Dimroth and a dropping funnel, and 5 drops of a 1% isopropanol solution of chloroplatinic acid was added.
The reaction was performed at 0 ° C for 2 hours. Then, cool to 60 ° C., add 30 g of methyl alcohol through a dropping funnel, and add 70
Silicone oil was synthesized by reacting at 0 ° C. for 1 hour.

As a result of infrared spectroscopy analysis of this silicone oil, it was confirmed that the SiH bond and the unsaturated bond had disappeared, and decene was added to the SiH group of methylpolysiloxane to give a residual SiH group. It was confirmed that methyl alcohol was dehydrogenated.

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Claims (3)

[Claims] 1. A composition for a hardened body, which comprises a powdery siliceous raw material and a calcareous raw material as main components, has the following general formula (1): (However, in the formula, R represents an alkyl group having 4 to 12 carbon atoms, R'represents an alkyl group having 1 to 3 carbon atoms, and y represents all the methyl groups in which the number of the alkyl group R is directly bonded to a silicon atom in one molecule. An integer for z to be 10 mol% or more of the number of groups, z is 1 or 2, and 3 ≦ x + y + z ≦ 20.) A water-repellent cure characterized by being added. Body composition. 2. A water-repellent cured product containing the silicone oil of the general formula (1). 3. The water repellent cured product according to claim 2, which is lightweight cellular concrete.