JPS6230216B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a heat-resistant grout, and its purpose is to provide a grout that can be used in fire-resistant and heat-resistant structures and buildings. Conventionally, the main uses as grout materials are:
Examples include adhesion between concrete, adhesion between concrete and metal, and adhesion between metals. Originally, concrete is prone to cracking due to the characteristics of its material, and cracks are also likely to occur at joints of concrete and between layers of concrete for the structure and finishing mortar. In that case, these cracks significantly reduce the durability of the structure,
This can lead to water leakage and corrosion of reinforcing steel, so it is necessary to inject grout into the cracks to repair them. In addition, as an example of bonding concrete and metal, holes are drilled in the concrete in advance to a depth equivalent to the penetration of embedded anchor hardware, various supports or handrail hardware, partition studs, embedded reinforcing bars, etc. There is a method of firmly adhering and fixing by rooting it in and filling it with grout material. Next, as an example of metal-to-metal bonding, there is a linear joint method for reinforcing bars, in which a deformed reinforcing bar whose surface has been hot-rolled into a spiral thread shape is machined with threads on its inner surface. When connecting with a coupler, there is a method in which grout is injected to eliminate play between the coupler thread and the reinforcing bar thread due to the dimensional difference. The clearance between this deformed reinforcing bar and the coupler is usually about 2 mm. These plays cause cracks in the concrete at joints when external forces act on the reinforced concrete. As for the materials conventionally used as such grout materials, epoxy resin is the most common, and other materials include unsaturated polyester resin and polyurethane resin. However, a major drawback of these grout materials is that they do not have sufficient heat resistance. There are inorganic grout materials that are heat resistant, but they are hard and brittle and have low peel adhesion strength and impact adhesion strength, as well as poor airtightness and water resistance.
It has drawbacks such as requiring high temperatures for curing. In recent years, the need for fire-resistant and heat-resistant structures to protect human lives and buildings from fire has increased, and legal standards are also being revised. In the event of a fire, approximately 80mm deep from the mortar surface inside the building
It is said that the temperature reaches 350℃, and the temperature reaches 50℃ in a 150mm area. If exposed to such high temperatures, for example, the grout at a threaded joint becomes soft, the reinforcing bar joints will become loose, and large cracks will develop in the concrete at the joint, making it difficult for stress to propagate between the reinforcing bars. If this is not done, the basic structure of the building will collapse due to external forces, causing a serious accident. Additionally, if the grout injected into a concrete wall softens, the original adhesive fixation cannot be maintained due to external forces, and the wall may fall, endangering people's lives. In addition, it is necessary to take safety measures based on the assumption that joints of reinforcing bars in reinforced concrete used in structures such as nuclear power plants will be exposed to high temperatures of 130°C or higher. Conventionally, the method of joining reinforced concrete reinforcing bars in nuclear power plant structures is to apply torque to two nuts placed on both sides of a coupler, and introduce axial force into the joint to forcibly bring it into close contact with the mating part, thereby eliminating play. It is being reduced. However, this method is inefficient and has major problems such as prolonging the construction period and increasing construction costs. On the other hand, if joints could be formed using a method of injecting heat-resistant grout, nuclear power plant equipment would have the great effect of shortening the construction period and reducing equipment costs. From the above explanation, the following points should be mentioned as practical points for a heat-resistant grout material. (1) It has sufficient heat resistance without being hardened by heat. (2) Good curability at room temperature or low temperature. (3) Long pot life. (4) Good storage stability. (5) The blending ratio is simple and the tolerance for blending errors is wide. These characteristics will be described in turn below. Among these, it is particularly important to have sufficient heat resistance when cured at room temperature without heat curing. At a construction site, it is extremely difficult and virtually impossible to inject grout into a structure and harden the grout by heating. There are many locations where grout is injected, and it is extremely difficult to secure a heat source at all of the locations. Heating by direct flame is undesirable because it poses a risk of fire and requires a lot of manpower, increasing labor costs. In addition, electric heating causes a large increase in costs, and there are many iron bars, reinforcing bars, etc. at construction sites, and there is a risk of electric shock accidents due to electrical leakage. Adhesives that can obtain sufficient heat resistance through heat curing include aromatic amine-cured epoxy resins, epoxy novolac resins, polybenzimidazole resins, and polyimide resins, but none of them require sufficient heat resistance to be obtained. It is necessary to cure at a low temperature of 150℃ or higher and a high temperature of nearly 400℃. Therefore, at present, these adhesives are virtually not used as grouting materials. Regarding curability at room temperature or low temperature, gelation from a liquid state to a solid state must be achieved at least in these temperature ranges. Since grout materials are often used outdoors, curing must proceed sufficiently even at temperatures of around 5° C. in winter. It is generally known that the heat resistance of thermosetting resins increases as the curing temperature increases. The reason is that the higher the curing temperature, the higher the crosslinking density and the more thermally stable. Therefore, in order to sufficiently cure the resin at a low density and increase the crosslinking density, it is essential to select a resin that has a high curing reaction rate at that temperature. Further, although the heat-resistant grout of the present invention is a two-component type, the pot life from the time the two components are sufficiently mixed until the time it is injected must be long enough to be practical. If the pot life is short, the resin will begin to harden and its viscosity will increase before the pouring operation begins, and the fluidity will change over time, making the pouring operation difficult or impossible. Usually the pot life is at least 5
Minutes are necessary. In addition, the grout material must have good storage stability throughout the seasons. The temperature difference between summer and winter reaches more than 30℃. Particularly in summer, if the two liquids before mixing react or change in quality due to high temperatures and the viscosity of the system increases, injection becomes difficult. Further, if the filler contained in the grout material settles during storage of the grout material, it is inconvenient that the filler must be sufficiently stirred to form a uniform liquid before use. Storage stability is also an extremely important issue for grout materials. It is desirable that the mixing ratio of the two-component mixture be simple. In actual grouting operations, the amounts of the two liquids mixed at one time often change each time. If the mixing ratio is complicated, the required amount of each liquid will not be a simple number, making it easy to make mistakes in weighing. Further, even if the mixing ratio is incorrect, the physical properties of the cured product will not change as much as possible. Epoxy resin, which is most commonly used as a grout material, can become sticky forever if the mixing ratio of resin and curing agent is incorrect, making it impossible to achieve the desired physical properties and purpose. Since epoxy resin is an equimolar reaction of resin and curing agent, the physical properties will deviate from the desired properties no matter which one is present in more or less amount. The most desirable blending ratio is 1:1. It is difficult to make a mistake because the amount of each liquid collected is the same and the sum is the amount required as grout material. Some epoxy resin grouting materials have a 1:1 mixing ratio, but this curing agent requires the use of polyamide with a high PHR. However, when polyamide is used as a curing agent, the crosslinking density becomes low and the heat resistance decreases. Since the grout material of the present invention needs to have heat resistance, ordinary epoxy cannot be used. Based on the above-mentioned recognition, the present inventors have worked for many years to develop a heat-resistant grout material that satisfies these points, and as a result of intensive research, they have arrived at the present invention. That is, the heat-resistant grout material obtained by the present invention has (a) an alicyclic epoxy resin, (b) two or more silanol groups in one molecule, and the hydroxyl group in the silanol group is 2.0 to 2.0. It is a 6.0% by weight organosilicon compound, the weight ratio of (a) and (b) is 8/1 to 1/1, and (c) fillers other than metal powder and fine powder silica are not included.
An antisettling agent containing 10 to 70% by weight and having no (d) silanol group or basic nitrogen group, and (e) the above-mentioned
(a), (b), (c), and (d) at 35°C in the presence of an organoaluminum compound in an amount of 0.05 to 5% by weight based on the total amount of resin.
The following is a method for producing a heat-resistant grout material, which is characterized by curing without substantially heating. The epoxy resins used in the present invention are limited to cycloaliphatic epoxy resins. Bisphenol A
Alternatively, an epoxy resin synthesized from bisphenol F and epichlorohydrin cannot be used because it has insufficient curing properties at room temperature or low temperature as intended by the present invention, and cannot achieve the content of the present invention. For the same reason, novolak type epoxy resins cannot be used either. As an alicyclic epoxy, Commercial product name ERL-4221 (Union Carbide) Celloxide #2021 (Daicel Chemical) Commercial product name ERL-4299 (Union Carbide) Commercial product name: ERL-4234 (Union Carbide) Alicyclic epoxy with a 1/2-bond polybutadiene skeleton Commercial product names: Epoxy EPB-27, EPB-23 (Nippon Soda), etc. These can be used alone or in combination. The organosilicon compound used in the present invention has two or more silanol groups in one molecule,
And the hydroxyl group in the silanol group is 2.0 to 6.0% by weight, preferably 3.0 to 5.0% by weight. If it is less than 2.0% by weight, curability at room temperature or low temperature is poor and the desired heat resistance cannot be obtained. Moreover, if it exceeds 6.0% by weight, the storage stability of the organosilicon compound deteriorates, so that it cannot be used practically. Organosilicon compounds having one silanol group in one molecule are not preferred as heat-resistant grout materials targeted by the present invention. This is because although it hardens at room temperature, sufficient heat resistance cannot be obtained. However, the addition of a small amount of an organosilicon compound having one silanol group per molecule may be an effective means for lowering the crosslinking density of the cured product and reducing the brittleness of the material. If the amount added exceeds 30% of the total organosilicon compound, the heat resistance will be significantly lowered, so it should be kept below 30%. Examples of the organoaluminum compounds used in the present invention include aluminum chelate compounds and aluminum alcoholates. Specifically, aluminum acetylacetonate, aluminum 3
-bromoacetylacetonate, aluminum ethyl acetylacetonate, aluminum methyl acetylacetonate, aluminum triisopropoxide, aluminum tri-sec-butoxide, and the like. It is already known that an organoaluminum compound is an effective catalyst for the reaction between an organosilicon compound having a silanol group and an epoxy resin, and is described, for example, in JP-A-51-118728. The organic aluminum compound added in the present invention is about 0.05 to 5%, preferably 0.3 to 3.0%, based on the resin excluding fillers. A catalyst amount within this range provides the best balance as a heat-resistant grout material in terms of room temperature curability, pot life, and heat resistance. When the amount of catalyst is increased, room temperature curability improves, but heat resistance tends to decrease. In addition, (a) alicyclic epoxy resin and (b) 2 in one molecule.
an organosilicon compound having 2 or more silanol groups and 2.0 to 6.0% by weight of hydroxyl groups in the silanol groups, and the weight ratio of (a) and (b) is 8/1 to 1/1. Yes, preferably from 6/1 to 2/1.
If the weight ratio exceeds 8/1, room temperature curability as a heat-resistant grout material deteriorates, making it impractical. Furthermore, if the weight ratio is less than 1/1, room temperature curability tends to deteriorate, resulting in low mechanical strength and low elastic modulus, which is not preferable. The heat-resistant grout of the present invention is a two-component type, but
Regarding the resin components of each liquid, liquid A is an alicyclic epoxy and an organic silicon compound having two or more silanol groups in one molecule, and liquid B is an alicyclic epoxy.
The organoaluminum compound of the catalyst is blended into the B solution. Further, the filler is added to liquid A and liquid B, and as mentioned above, the mixing ratio of the two liquids is preferably 1:1, and most preferably 1:1 in terms of weight ratio and volume ratio. Therefore, it is convenient to add the same filler to the A liquid and the B liquid in the same proportion. The filler used in the present invention is not particularly limited except for finely powdered silica and metal powder. Fine powder silica fillers include fused silica and white carbon, and usually have a single particle size of 40 μm or less. When these are added to liquid A or liquid B, the viscosity of both liquids increases over time. The reason for this is not necessarily clear, but when it is contained in liquid B, the silanol group contained in a small amount in the filler reacts with the alicyclic epoxy group in the presence of the organoaluminum compound, resulting in thickening. This is understood to be because aluminum or silica itself, which is contained in a small amount in the fine powder silica filler, has a catalytic action when contained in Liquid A. As the filler, calcium carbonate, barium sulfate, talc, glass beads, glass chips, zinc oxide, aluminum oxide, titanium oxide, carbon black, etc. are preferably used. Metal powders such as iron powder and aluminum powder have a slight catalytic effect on the reaction between the alicyclic epoxy and the compound having a silanol group, so when they are included in the A liquid, the viscosity of the A liquid increases over time. Although it is possible to add metal powder to liquid B, this is not preferred because the mixing ratio of liquids A and B will not be the ideal 1:1. The purpose of adding a filler is to increase the viscosity of the grout to obtain fluidity that is convenient for work, to reduce the coefficient of thermal expansion, and to reduce the cost of heat-resistant grout by adding a filler that is cheaper than the resin component. In addition, it suppresses curing heat generation and extends pot life. (a) an alicyclic epoxy resin and (b) an organosilicon compound having two or more silanol groups in one molecule, and the amount of hydroxyl groups in the silanol groups being 2.0 to 6.0% by weight; If the weight ratio of () and (b) is within the range of 8/1 to 1/1, the organic aluminum compound will harden extremely rapidly. Pot life is 25 with a mixed amount of 100g.
℃ for about 1 minute, so it cannot be practically used as the heat-resistant grout material of the present invention because there is almost no time for mixing the two liquids or for pouring after mixing. By adding fillers, it is possible to extend the pot life to some extent. As the filler content increases, the pot life becomes longer, but as the resin component decreases, the viscosity of the system increases and the room temperature curability deteriorates. Therefore, a well-balanced formulation of pot life, viscosity, and room temperature curability is required. The viscosity of the heat-resistant grout filled in the approximately 2 mm clearance between the helical thread-shaped deformed reinforcing bar and the coupler threaded on the inner surface, which is one of the above-mentioned linear reinforcing bar joint methods, is 10 to 30. 40,000 to 90 in the temperature range of ℃
Ten thousand centipoise is preferred. If the viscosity is higher than this, it will take time to fill with a grout injection device and efficiency will be poor, and if the viscosity is low, it will flow out from the gap between the deformed reinforcing bar and the coupler, resulting in insufficient filling and material loss. In order to obtain a suitable viscosity, it is necessary to appropriately select the type and amount of the filler and the type and amount of the anti-settling agent (also a thixotropy imparting agent), and the appropriate amount to be added will be described later. By using an appropriate anti-settling material, it is possible to adjust the viscosity to an appropriate level without using fillers, and to adjust the pot life and room-temperature curability. However, when injecting grout, the temperature should be below 35°C, preferably below 30°C. If the temperature exceeds 35°C, the pot life becomes too short and grouting becomes virtually impossible. Generally, the addition of a filler with thin particles or a filler with a high oil absorption rate tends to increase the viscosity, and since thin particles are difficult to settle, the amount of anti-settling agent can be reduced. The antisettling agents used in the present invention exclude those having a silanol group or a basic nitrogen group. Finely powdered amorphous silica has silanol groups, and is often used to prevent sagging and sedimentation. Those having basic nitrogen groups include lecithin and amine complexes of montmorillonite. Anti-settling agents are usually added in an amount of 0.1 to 2% by weight, but when finely powdered amorphous silica with silanol groups is added to liquid A, it hardly increases the viscosity.
In liquid B, the viscosity clearly increases. Further, antisettling agents having a basic nitrogen group cannot be used in the present invention because they decompose the organoaluminum compound that is the catalyst and reduce its activity. Examples of the antisettling agent used in the present invention include hydrogenated castor oil, polyethylene oxide, methyl cellulose, and asbestos. Among them, hydrogenated castor oil is the most suitable in terms of pot life, room temperature curability, and viscosity. The present inventors found out. The amount of the filler used in the present invention varies depending on the type and amount of the antisettling agent used in combination, but it is usually 10 to 70% by weight, and in order to satisfy the above conditions, it is 40 to 70% by weight. Preferably it is 60%. If the amount added is less than 10%, the pot life will be short, the heat resistance will be poor, and the cost as a grout material will be high, which is not preferable. If it exceeds 70%, room temperature curability deteriorates and mechanical strength also decreases, which is not preferable. As described above in detail, the significance of the present invention is to (a) have an alicyclic epoxy resin and (b) have two or more silanol groups in one molecule, and the hydroxyl group in the silanol group is from 2.0 to 2.0. The basic method is to cure 6.0% by weight of an organosilicon compound in the presence of organoaluminium at a weight ratio of 8/1 to 1/1, and then add appropriate fillers and anti-settling agents. As a result, a heat-resistant grout material having appropriate pot life, viscosity, and storage stability can be obtained.
This provides a grout material that can be used in fire- and heat-resistant structures and buildings and has sufficient heat resistance only by curing at room temperature, and such a grout material has not previously existed. Hereinafter, the content of the present invention will be explained in more detail with reference to Examples. Example 1 The average composition formula is RaSiO4-a/2, R consists of 63 mol% methyl group and 37% phenyl group, and a=
1.6 and 200 parts of silicone with 5% by weight of OH group in the silanol group, 300 parts of Celoxide #2021 (trade name: Daicel Chemical Industries), and hydrogenated castor oil-based Disparon #305 (trade name, Kusumoto Kasei) as an anti-settling agent.
6 parts were added, heated to 80°C, and stirred with a dissolver for 30 minutes. After cooling to 40°C, 495 parts of calcium carbonate and 5 parts of carbon black were added and stirred for 1.5 hours. The temperature of the mixture reached 65°C due to the heat of stirring.
This liquid (liquid A) is black. Separately, 480 parts of Celloxide #2021 (trade name), 19 parts of aluminum acetylacetonate, and 10 parts of Disparon #305 (trade name) were added and stirred at 80°C for 30 minutes with a dissolver. The mixture became clear. After cooling to 40℃, add 492 parts of calcium carbonate and 5 parts of titanium oxide to 1.5
I stirred the time. The temperature of the mixture reached 62°C.
This liquid (liquid B) is white. The viscosity at 25℃ measured with a rotational viscometer is 55,000 centipoise for liquid A, and 55,000 centipoise for liquid B.
The liquid was 30,000 centipoise hot. Table 1 shows the results of curing liquid A and liquid B at a predetermined mixing ratio under given conditions. The pot life is determined by taking both liquids A and B, which have been adjusted to a specified temperature, into a paper cup at the specified mixing ratio so that the mixed amount is 250 g, stirring them thoroughly until the color becomes a uniform gray color, and then standing still. This was the time taken for the contents to reach 70°C. Further, the curing time for a 2 mm thick film was defined as the time when both solutions A and B adjusted to a predetermined temperature were mixed, applied on an iron plate, and the coating was struck with a metal rod to make a metallic sound.

[Table] Next, dumbbells (JIS-K 6911 tensile test specimens for molding materials, but after curing time of 24 to 48 hours) were prepared under the same Exp No. conditions as in the measurement of the curing time of the thin film in Table 1. Strength and elastic modulus were measured at a predetermined temperature using a universal testing machine with a tank. All test pieces were placed in a constant temperature bath for 10 minutes and then measured (Table 2).

[Table] From the results in Tables 1 and 2, it can be said that it has good curability even at low temperatures and has excellent heat resistance. Also A, B
Even if the blending ratio of both liquids changes, the tensile strength and elastic modulus hardly change, so it can be said that even if there is an error of about 20% in the blending ratio, the performance as a heat-resistant grout material will not change. On the other hand, as a storage stability test, liquids A and B were placed in cans, sealed, and left outdoors for 60 days in the summer, but no sedimentation of the co-fillers for liquids A and B was observed, and the viscosity was It didn't change. Example 2 The same silicone used in Example 1, a solution (6% concentration) in which aluminum acetylacetonate was previously dissolved in Celoxide #2021 (trade name), and Celoxide #2021 (trade name) were combined in an appropriate manner. Celoxide #2021 (product name) as shown in 3.
and silicone, and add calcium carbonate to this to make the calcium carbonate content 55%.
The catalyst concentration was 0.75% based on the resin component. A thin film (2 mm thick) was formed using these test solutions in the same manner as in Example 1.
A hardenability test was conducted. The results are shown in Table 3. The evaluation of curing time was the same as in Example 1.

[Table] Example 3 In Example 1, two liquids were prepared in which only the amount of aluminum acetylacetonate in liquid B was changed, and the pot life was measured at a blending ratio of 1:1. Also
A test piece was prepared in accordance with ASTM D 648-56 (JIS measurement method), and the fiber stress was 18.6.
The heat distortion temperature was measured in Kg/cm ² . The results are shown in Table 4.

[Table] The results in Table 4 show that it is undesirable to use too much catalyst in terms of pot life and heat distortion temperature. Example 4 The average compositional formula is shown as RaSiO4-a/2, R consists of 55 mol% methyl group and 45 mol% phenyl group,
Solution A was prepared in the same manner as in Example 1 except that a silicone having a=1.57, 2.2 silanol groups per molecule, and an OH group content of 3.7% by weight of the silanol groups was used. A mixture of this A liquid and B liquid of Example 1 was thoroughly stirred at a weight ratio of 1:1, and the surface was roughened with sandpaper (No. 100) to a width of 25 mm and a length of 100 mm.
mm, adhesive area is 25 x 12.5 on two steel plates with a thickness of 1.6 mm.
They were overlapped to a size of mm ² and left at 25°C for 24 hours. When the tensile shear adhesive strength of this was measured using a tensile tester at 23°C, the adhesive strength was 89 kg/cm ² . On the other hand, Solution A was prepared in the same manner as in Example 1, except that diphenylmethylsilanol, which has only one silanol group in one molecule, was used;
An attempt was made to measure the tensile shear adhesive strength under the same conditions by mixing liquid B at a weight ratio of 1:1, but even after 24 hours at 25° C., curing was insufficient and there was no substantial adhesion. Example 5 Solution B was prepared in Example 1 using aluminum triisopropoxide instead of aluminum acetylacetonate. However, aluminum triisopropoxide was not completely dissolved in Celoxide #2021 (trade name). The weight ratio of this B liquid and A liquid of Example 1 was 1:1, and the curability of the thin film was measured in the same manner as in Example 1. As a result, the curing time for a 2 mm thick coating at 25°C is approximately
It took 450 minutes. Example 6 The following tests were conducted on the A and B solutions prepared in Example 1 to examine their practical performance as heat-resistant grout materials. Threaded reinforcement D51 Sumine screw bar SD40 Four types of hot rolled steel bars, nominal diameter 50.8mm
D51 (Sumitomo Metal Industries) was used to connect. From the grout injection port located in the center of the coupler, a grout material made by uniformly mixing both liquids A and B at a weight ratio of 1:1 is poured into the space between the reinforcing bars and the coupler using a grout injection device.
The solution was injected until it ran out. The clearance between the threaded head of the reinforcing bar inside the coupler and the female thread of the coupler is approximately 2 mm, and the amount of grout that is completely injected is approximately
It was 200g. Approximately 18 hours after grouting 23
It was left at room temperature at °C. After that, it was set in a tensile testing machine equipped with a constant temperature bath at 132°C, and a tensile test was conducted. The tensile stress was increased to 95% (approximately 3800 Kg/cm ² ) of the tensile yield value at 132° C. of the sumine screw bar alone. The elastic modulus of Sumine screw bar at that point is 2.1×10 ⁶
Kg/cm ² , but the joint part injected with heat-resistant grout material had a value of 2.3×10 ⁶ Kg/cm ² , which is higher than that of the sumine screw bar alone, and it is clear that the heat resistance at 132°C is sufficient. Summer.

Claims (1)

[Scope of Claims] 1. (a) Alicyclic epoxy resin; (b) organosilicon having two or more silanol groups in one molecule and containing 2.0 to 6.0% by weight of hydroxyl groups in the silanol groups; A compound in which the weight ratio of (a) and (b) is 8/1 to 1/1, and (c) fillers other than metal powder and fine powder silica are 10
An antisettling agent containing ~70% by weight and having no (d) silanol group or basic nitrogen group, and (e) the above-mentioned
(a), (b), (c), and (d) at 35°C in the presence of an organoaluminum compound in an amount of 0.05 to 5% by weight based on the total amount of resin.
The following method for producing a heat-resistant grout material, which is characterized by curing without substantially heating. 2. The method for producing a heat-resistant grout according to claim 1, wherein the organoaluminum compound is an aluminum chelate compound or an aluminum alcoholate.