Two-pack type epoxy resin composition

Abstract

To provide a two-pack type epoxy resin composition which is excellent in coating properties such as dryness and curability, while being an aqueous coating material containing no volatile organic solvent, and to provide a two-pack type epoxy resin composition whose characteristics are applicable to other substances other than the coating material.SOLUTION: A two-pack type epoxy resin composition has: a main agent containing at least an epoxy resin, water, and alumina cement in which the hydration reaction is blocked; and a sub agent containing an epoxy resin curing agent for curing the epoxy resin and a basic aqueous solution for releasing the blocking of the hydration reaction of the alumina cement. The two-pack type epoxy resin composition is usable as a resin mortar material, a putty material, an adhesive or a fiber-reinforced plastic, other than a coating material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a two-component epoxy resin composition. [Background technology]

[0002] Conventionally, epoxy resin paints, whose main components are aromatic epoxy resins such as bisphenol A epoxy resin and bisphenol F epoxy resin, have been widely used as factory floor paints due to their excellent durability, chemical resistance, etc. Conventionally, epoxy resin paints have generally been made low-viscosity by blending volatile organic solvents to improve paint workability.

[0003] In addition, in order to ensure the shelf life (pot life) of epoxy resin paints until the time of use, paint compositions in which the epoxy resin and the curing agent that cures the epoxy resin are separated into two liquids have been proposed and are being used.

[0004] In response to the recent demand for low VOCs, there has been a call for a shift to water-based epoxy resin paints for such organic solvent-based epoxy resin paints for a long time (see, for example, Patent Document 1). However, there is still a high demand for organic solvent-based epoxy resin paints, which are excellent in paint properties such as drying and curing properties, and coating film properties such as durability and chemical resistance.

[0005] Therefore, it is desirable to solve the problems of organic solvent-based epoxy resin paints derived from volatile organic solvents, while improving the paint properties such as poor drying under high humidity conditions, delayed curing at low temperatures, and film thickness reduction due to water evaporation, which are problems of water-based epoxy resin paints, as well as the coating film properties such as durability and chemical resistance.

[0006] In water-based paints, white Portland cement and alumina cement are used as inorganic binders, but because they are inferior in physical properties such as thin film formation, stain resistance, and impact resistance, and in handling properties such as paintability, color matching, and storage stability, they are not commonly used as finishing materials that can be easily applied with a roller, for example. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication 2020 / 110601 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a two-component epoxy resin composition which is a water-based paint containing no volatile organic solvent and yet has excellent paint physical properties such as drying property and curing property, etc. Another object of the present invention is to provide a two-component epoxy resin composition whose properties can be applied to things other than paints. [Means for solving the problem]

[0009] The above object can be achieved by the following aspects of the present invention. That is, one aspect of the two-component epoxy resin composition of the present invention comprises a base material containing at least an epoxy resin, water, and an alumina cement whose hydration reaction is blocked; an epoxy resin curing agent for curing the epoxy resin, and a sub-agent including a basic aqueous solution for unblocking the hydration reaction of the alumina cement; has.

[0010] In the above aspect, it is preferable that the coating liquid prepared by mixing the main agent and the auxiliary agent has a water content of 5 to 30 mass % and a cured product-forming component content of 85 to 100 mass %.

[0011] In the above embodiment, the epoxy resin is preferably a self-emulsifying liquid epoxy resin, and the epoxy resin curing agent is preferably a polyamine.

[0012] The two-component epoxy resin composition of the above embodiment can be used as a coating material.

[0013] Moreover, by further blending coarse aggregate with the two-component epoxy resin composition of the above embodiment, it can be used as a resin mortar material.

[0014] Furthermore, by further blending a thickener with the two-component epoxy resin composition of the above embodiment, it can be used as a putty material or an adhesive.

[0015] In the two-component epoxy resin composition of the above embodiment, the main component and the auxiliary component are mixed to prepare a mixed liquid, and then the mixed liquid is impregnated into fibers, thereby obtaining a fiber-reinforced plastic. Effect of the Invention

[0016] According to the present invention, it is possible to provide a two-component epoxy resin composition which is a water-based paint containing no volatile organic solvent and yet has excellent paint physical properties such as drying property and curing property, etc. It is also possible to provide a two-component epoxy resin composition whose properties can be applied to things other than paints. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a schematic explanatory diagram showing the state of a main component and a sub-component in the two-component epoxy resin composition according to the present embodiment. [Diagram 2] FIG. 2 is a schematic explanatory diagram showing the state of a coating film formed by a coating liquid prepared from the two-component epoxy resin composition according to the present embodiment. [Diagram 3] 1 is an optical microscope photograph (100x) of a cross section of a coating film formed with a coating liquid prepared from a two-component epoxy resin composition according to an example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The two-part epoxy resin composition of the present invention was developed for use in coating materials, but its unique curing mechanism and properties make it applicable to a variety of uses other than coating materials. In the following embodiments, the use as a coating material will be mainly described, and applications to other uses will be described later.

[0019] <Embodiment of paint application> Hereinafter, a two-component epoxy resin composition according to one embodiment of the present invention for use as a coating material (hereinafter, may be simply referred to as a "resin composition") will be described. The resin composition according to the present embodiment contains the main component and auxiliary components described below.

[0020] Base material: At least epoxy resin, water, and alumina cement with hydration reaction blocked · Secondary agent: Epoxy resin hardener that hardens the epoxy resin contained in the main agent, and a basic aqueous solution that unblocks the hydration reaction of the alumina cement contained in the main agent

[0021] In addition to the above essential components, other components are appropriately blended in at least one of these components or as a separate component in the resin composition according to the present embodiment. Below, the two-liquid epoxy resin composition consisting of the main component and the auxiliary component will be mainly described, and the essential components contained in each of the main component and the auxiliary component will be described, followed by a description of the other components.

[0022] [(1) Main ingredient] The (1) base material in the resin composition according to the present embodiment contains, as essential components, an epoxy resin, water, and alumina cement.

[0023] (Epoxy resin) Examples of the epoxy resin used in this embodiment include bisphenol type epoxy resins such as bisphenol A, bisphenol F, bisphenol S, and halogenated bisphenol A; biphenyl type epoxy resins; alicyclic type epoxy resins; ester type epoxy resins such as dibasic acids; terpene diphenol type epoxy resins; and the like. In addition, phenol novolac epoxy resins; alkylphenol novolac epoxy resins such as cresol novolac epoxy resins; bisphenol A novolac epoxy resins; and the like can also be used. These epoxy resins may be used alone or in combination of two or more.

[0024] The method for producing the epoxy resin used in the present embodiment is not particularly limited, and examples thereof include a direct synthesis method or an indirect synthesis method for bisphenol A type epoxy resin and bisphenol F type epoxy resin, a method of reacting an epoxy resin with an aliphatic monocarboxylic acid to obtain an epoxy resin having a hydroxyl group introduced therein, and a method of reacting an epoxy resin with a monophenol or the like to obtain an epoxy resin having a hydroxyl group introduced therein.

[0025] As the epoxy resin used in this embodiment, both a self-emulsifying epoxy resin and a non-self-emulsifying epoxy resin can be used. When a non-self-emulsifying epoxy resin is used, it is sufficient to emulsify it by mixing it with an emulsifier or a self-emulsifying resin and disperse it in water. However, it is preferable to use a self-emulsifying epoxy resin because forced emulsification using an emulsifier requires stirring with a shear force, which makes the work complicated, and it is difficult to ensure performance such as water resistance even if forced emulsification is performed using an emulsifier. In addition, it is preferable to use a self-emulsifying epoxy resin in order to maintain the uniformity of the paint and to increase the uniformity of the coating film formed, since it is in a state where water is dispersed in the epoxy resin, which is the opposite of general emulsification.

[0026] A self-emulsifying epoxy resin is an epoxy resin that spontaneously becomes a dispersion or emulsion upon contact with water without the aid or action of a special emulsifier or dispersant. Specific examples of self-emulsifying epoxy resins include epoxy resins that have a hydrophilic portion introduced therein, such as epoxy resins that have a hydrophilic portion in the molecule. Specific examples of the hydrophilic portion include ionic hydrophilic group portions and nonionic polyalkylene oxide skeletons.

[0027] An epoxy resin having a polyalkylene oxide skeleton in the molecule can be obtained, for example, by reacting an epoxy resin with a polyalkylene glycol in a conventional manner under conditions of an excess of epoxy equivalent. The polyalkylene glycol used in this case is not particularly limited, and examples thereof include alkylene glycols such as ethylene glycol, propylene glycol, and butylene glycol, polyethylene glycols such as diethylene glycol and triethylene glycol, and polypropylene glycols having a degree of polymerization of 2 to 10.

[0028] (water) The water used in this embodiment is not particularly limited, and any of tap water, industrial water, river water, groundwater, deionized water, pure water, etc. can be used. As long as the salt content, sulfur content, etc. is not extremely high, water can be used without any problems, but of course, it is preferable that the amount of impurities is small.

[0029] (Alumina cement) The alumina cement used in this embodiment is not particularly limited, and for example, any of alumina cements of types 1 to 5 specified in Japanese Industrial Standard JIS R2511 (abolished in 2000) can be used.

[0030] The alumina cement used in this embodiment is blocked from hydration. To block the hydration of the alumina cement, a blocking agent (also called a "hydration stopper") is used. It is known that the alumina cement can stop the hydration and stabilize the suspension by using the blocking agent.

[0031] The blocking agent that blocks the hydration reaction of alumina cement is a substance that exhibits acidity in aqueous solution. Specific blocking agents include metaphosphoric acid, phosphorous acid, phosphoric acid, phosphonic acid, and phosphorus-containing compounds that can produce these phosphorus compounds by reacting with water; oxycarboxylic acids and their salts; polyacrylic acid and its derivatives; salts of acrylic acid; chelating agents; condensed phosphates; aluminum phosphate and boric acid. These can be used alone or in combination of two or more.

[0032] The mechanism by which the blocking agent blocks the hydration reaction of alumina cement is thought to be as follows. When alumina cement comes into contact with water, it immediately reacts to form Ca 2+ and Al 3+ As the ions are dissolved, the pH of the water rises. Then, at a certain pH level, alumina cement hydrate precipitates. However, if an acidic blocking agent is present, the dissolved Ca 2+ is captured, preventing the pH from rising and maintaining the water at a slightly acidic state, thereby inhibiting the progress of the hydration reaction of alumina cement.

[0033] On the other hand, in the hydration reaction of alumina cement, gelation of aluminum hydroxide is caused. This gelled aluminum hydroxide is deposited and coated on the surface of the alumina cement, and is stably present on the surface of the alumina cement when the water is kept acidic. Therefore, it is presumed that the hydration reaction of the alumina cement is stopped. Note that this mechanism of action for stopping hydration is merely presumed, and the present embodiment is not limited by this mechanism of action.

[0034] In this embodiment, the amount of blocking agent added depends mainly on the acidity of the blocking agent and the amount of alumina cement in the base material. In practice, the amount of blocking agent added is preferably adjusted so that the pH of the base material is 2 to 7, and more preferably 3 to 6.

[0035] If the pH of the base agent becomes too high, there is a concern that the hydration stopping effect will be insufficient, and the preservation properties may be insufficient. On the other hand, if the pH of the base agent becomes too low, the base agent may generate heat and enter a pseudo-setting state, which also tends to result in insufficient preservation properties. This pseudo-setting phenomenon is thought to be caused by a direct chemical reaction between alumina cement and acid.

[0036] The base material in the resin composition according to the present embodiment can be prepared by mixing the above-mentioned essential components with other components, which are appropriately blended as described below, and thoroughly stirring the mixture with, for example, a general rotary mixer so as to avoid uneven concentration.

[0037] [(2) Adjuncts] The auxiliary agent (2) in the resin composition according to the present embodiment contains, as essential components, an epoxy resin curing agent and a basic aqueous solution.

[0038] (Epoxy resin hardener) As the epoxy resin curing agent (hereinafter, sometimes simply referred to as "curing agent") used in this embodiment, those usually used as curing agents for epoxy resins can be used as they are. Specific curing agents include, for example, polyamide amines, polyamines such as aliphatic polyamines and modified polyamines, epoxy resin amine adducts, aromatic amines, hydrazides, dicyandiamide, imidazole, tertiary amines, acid anhydrides, phenolic resins, urea resins, resol resins, amino resins, ketimines, acid-terminated polyester resins, isocyanates, and blocked isocyanates. These curing agents may be used in combination depending on the purpose. Among these, polyamines are preferable as the curing agent used in this embodiment in terms of the reaction rate with epoxy resins at room temperature and the control thereof, the mixed viscosity with epoxy resins and the control thereof, and the mixed stability with an alkaline aqueous solution.

[0039] (basic aqueous solution) The basic aqueous solution used in this embodiment is a material that unblocks the hydration reaction of the alumina cement contained in the base agent and restores the progress of the hydration reaction, and can be called a hydration initiator in contrast to the blocking agent contained in the base agent.

[0040] As the basic aqueous solution, at least one selected from the group consisting of aluminates, hydroxides, carbonates, nitrites, silicates and borates of alkali metals, and oxides and hydroxides of alkaline earth metals can be used. The type and amount of the hydration initiator can be selected according to the type and amount of the blocking agent contained in the base agent.

[0041] The auxiliary agent in the resin composition according to the present embodiment can be prepared by mixing the above-mentioned essential components with other components that are appropriately blended as described below, and thoroughly stirring the mixture with, for example, a general rotary mixer so as to avoid uneven concentration.

[0042] Each component contained in the main agent and auxiliary agent described above is commercially available as is or in a state where each component is mixed with water and other components, and can be easily obtained from the market. The resin composition according to the present embodiment can be prepared by procuring each component individually, or can be prepared by appropriately using a commercially available composition with a suitable blend and adjusting the blend of each component.

[0043] [Other ingredients] In addition to the above essential components, the resin composition according to the present embodiment may contain other components as necessary. Specifically, various additives such as pigments, aggregates such as glass beads, granite, and silica sand powder, anti-suspending agents, diluents, surface conditioners, and curing accelerators for epoxy resins, and the like.

[0044] Examples of pigments include pigments commonly used in paints, and are not particularly limited as long as they do not inhibit the stability of the resin composition. For example, various coloring pigments, such as inorganic pigments such as titanium dioxide, yellow lead, iron oxide, and red iron oxide, and organic pigments such as azo pigments and phthalocyanine pigments, and extender pigments such as calcium carbonate, talc, alumina, mica, baryte, and precipitated barium sulfate can be used. In addition, aggregates such as glass beads, kansui stone, and silica sand powder can also be used for the purpose of improving nighttime visibility, thickening the film thickness, and durability. The content of pigments and aggregates is not particularly limited, but it is preferable that the content is set to a level that does not significantly affect the properties of the coating film finally formed when used as a paint.

[0045] These other components may be contained in either the main agent or the auxiliary agent, or in both. Alternatively, a separate additive (which may be a liquid or a solid such as a powder) containing these other components may be prepared. In addition, in order to adjust the viscosity or concentration, the separate additive may contain water, or the additive may consist only of water. Such separate additives may be one type or two or more types.

[0046] [Mixing ratio] The resin composition according to the present embodiment is prepared in a state usable as a coating liquid by mixing the above-mentioned main agent, the above-mentioned auxiliary agent, and, if additives are prepared separately, all of the additives in a predetermined mixing ratio, and thoroughly stirring the mixture with, for example, a general rotary stirrer so as to avoid uneven concentration.

[0047] The amount of each component constituting the resin composition according to the present embodiment is determined so that the final coating solution will have an appropriate amount. Therefore, the amount of each component varies depending on the mixing ratio of the main component and the auxiliary component.

[0048] In this embodiment, when the term "when the main agent and the auxiliary agent are mixed to prepare the coating liquid" or "in the coating liquid" is used, it means that the main agent and the auxiliary agent are mixed, and if there is a separate additive, the additive is also mixed to finally "prepare the coating liquid". Hereinafter, the final coating liquid may be simply referred to as the "coating liquid".

[0049] In this embodiment, the amount of epoxy resin and epoxy resin curing agent is preferably within the range of 25 to 85% by mass in the coating liquid, and more preferably within the range of 45 to 75% by mass. If the amount of epoxy resin and epoxy resin curing agent is too large, the amount of water that can be blended becomes small, and it cannot be called a water-based paint, and if it is too small, the water and alumina cement cannot be properly dispersed in the mixture of epoxy resin and epoxy resin curing agent, so both are undesirable.

[0050] In this embodiment, the amount of epoxy resin curing agent to be blended varies depending on the type of epoxy resin curing agent to be used, the combination with the epoxy resin, and further the desired paint or coating film properties, and cannot be generalized. In general, the amount of epoxy resin curing agent to be blended is such that the equivalent of the epoxy resin curing agent (amine equivalent if the epoxy resin curing agent is an amine) is approximately the same as the epoxy equivalent of the epoxy resin. However, depending on the desired coating film properties, it is acceptable to make either the epoxy equivalent or the equivalent of the epoxy resin curing agent excessive.

[0051] In this embodiment, the amount of alumina cement is preferably within the range of 7.5 to 50% by mass in the coating liquid, and more preferably within the range of 15 to 35% by mass. If the amount of alumina cement is too large, the water and alumina cement cannot be properly dispersed in the mixture of the epoxy resin and the epoxy resin hardener, and if the amount of water that can be blended is too small, the amount of water that can be blended becomes too small to be called an aqueous coating material, and both are undesirable.

[0052] In this embodiment, the amount of the basic aqueous solution to be mixed may be an amount that can neutralize the acid of the blocking agent contained in the base agent or more. When the pH at the alumina cement interface becomes 8 or more by neutralization, the hydration reaction of the alumina cement resumes. In order to obtain an appropriate hydration rate, it is preferable that the pH is 9 or more.

[0053] In addition, since the basic aqueous solution is mixed with the curing agent, it is preferable that the concentration is such that it completely dissolves in the epoxy resin curing agent such as amine used. More preferably, a basic aqueous solution with a pH of about 13 to 14 is mixed with the curing agent, and the amount of the basic aqueous solution is such that the pH is maintained so that the hydration speed matches the curing speed of the resin mixture after mixing with the base agent. That is, if the amount of the basic aqueous solution is too small, hydration will not be completed and the resin cured product will be in a water-containing state, which may make it difficult to express the appropriate resin performance, and if the amount is too large, hydration will proceed first, not only will the original pot life not be obtained, but the finished surface may be deteriorated, which is not preferable. As described above, the specific appropriate amount of the basic aqueous solution will change depending on the type and amount of the alumina cement, blocking agent, or epoxy resin curing agent.

[0054] In this embodiment, the content of water in the coating solution is preferably within the range of 5 to 30% by mass, and more preferably within the range of 10 to 20% by mass. If the amount of water is too much relative to the alumina cement, an excess amount of water that is not consumed in the hydration reaction is generated, and must be volatilized when the coating film is cured, and the effects of the present invention, such as being less susceptible to the effects of humidity and temperature described below and being less susceptible to film thickness reduction due to water volatilization, are reduced. In addition, if the amount of water and dispersed alumina cement is too large, hydrates are dispersed in the epoxy resin, and the characteristics of the resulting cured body may be lost. On the other hand, if the amount of water is too small, it is not suitable to be called aqueous, and there is a concern that the viscosity of the coating solution will not be sufficiently reduced and the paintability will be reduced, which is not preferable.

[0055] The above water amounts are the conditions for a typical epoxy resin-based paint for floors that is applied with a trowel to ensure a certain degree of coating thickness (for example, about 1000 μm or more), but by using an excess amount of water that exceeds the above range (for example, the water content in the coating solution is more than 30 mass% and about 60 mass% or less), the viscosity can be further reduced, making roller coating possible and the coating film can be made thinner (for example, about 100 μm or less). In this case, since the excess water needs to be removed by evaporation, it is important to note that the time until the coating film hardens depends on the amount applied and the coating environment.

[0056] In this embodiment, the content of the curable product-forming component in the coating liquid is preferably 85 to 100% by mass, more preferably in the range of 95 to 100% by mass, and particularly preferably close to 100% by mass.

[0057] The term "hardened product-forming components" as used herein refers to all of the components in the coating solution that become hardened products through the curing reaction of the epoxy resin and the components that become hardened products through the hydration reaction of the alumina cement. The amount of water consumed by the hydration reaction of the alumina cement to become hardened products corresponds to the hardened product-forming components, while the excess amount of water that is not used in the hydration reaction does not correspond to the hardened product-forming components. Although the amount of hydration of the alumina cement is experimentally influenced by the concentration and amount of the basic aqueous solution that releases the block, the extender pigment used in combination, etc., it is estimated from experience that about 90% of the water by mass of the mixed alumina cement is fixed in the coating film through hydration (i.e., corresponds to the hardened product-forming components).

[0058] In this embodiment, a part or all of the water that contributes to the coating suitability of the coating solution is used in the hydration reaction of the alumina cement, and becomes a hardened material forming component. Therefore, the content of the hardened material forming component in the coating solution can be set to 100 mass % or close to 100 mass %, so that the reduction in film thickness due to the evaporation of the solvent can be suppressed.

[0059] The content of the cured product-forming component in the coating liquid can be determined by producing a cured product and measuring the weight change. In this embodiment, as an example, the content of the cured product-forming component was determined by the following method.

[0060] A mold (e.g., a polypropylene mold) with a depth of 4 mm and a diameter of 65 mm was prepared from which the hardened body would be easily removed. The mass a (g) that would result in a thickness of 4 mm was calculated from the specific gravity of the mixture, and the mixture of mass a was poured into the mold to produce a hardened body. Since the amount of weight lost will be calculated as a percentage later, the accuracy of the poured mass is sufficient within ±5%. The mixture was kept in a constant environment (temperature 23°C, humidity 50% RH) and the mass b (g) was measured after one month. The content S (%) of the hardened body-forming component was calculated from the measured value and the mass a when poured into the mold using the following formula (1). S = b / a × 100 (1)

[0061] [Painting of resin composition] The resin composition according to the present embodiment is used for coating in the state of the coating solution prepared as described above. The coating solution may be applied using a coating tool suitable for the coating thickness or the object to be coated, such as a trowel, spatula, brush, roller, applicator, or a known method such as a spray method using a lysine gun or a universal gun.

[0062] [Coating film formation mechanism] Fig. 1 is a schematic explanatory diagram showing the state of the main agent and the auxiliary agent (separate agent) in the resin composition according to this embodiment. As shown in Fig. 1, the main agent is in the state of w / o type emulsion in which the epoxy resin exhibits hydrophobicity (o) and water droplets (w) are dispersed therein. The water droplets contain alumina cement whose hydration reaction has been blocked by a blocking agent. The auxiliary agent contains an epoxy resin curing agent and a basic aqueous solution, and is an aqueous liquid.

[0063] When the main agent and auxiliary agent are mixed and stirred well, first, as shown by arrow a in Figure 1, the epoxy resin in the main agent reacts with the epoxy resin hardener in the auxiliary agent, and the hardening reaction of the epoxy resin progresses. At the same time, as shown by arrow b in Figure 1, the blocking agent in the main agent reacts with the basic aqueous solution of the auxiliary agent, neutralizing the blocking agent. Then, the hydration reaction block by the blocking agent is released, and a hydration reaction begins between the alumina cement in the main agent and water, as shown by arrow c1 in Figure 1. Also, as shown by arrow c2 in Figure 1, the alumina cement in the main agent also undergoes a hydration reaction with the water contained in the auxiliary agent.

[0064] The coating solution prepared by mixing the main agent and the auxiliary agent is in a state in which the above-mentioned epoxy resin hardening reaction and alumina cement hydration reaction proceed simultaneously. Before these reactions proceed, the coating solution is subjected to the painting operation. The coating film formed in this way is formed by the progress of these two reactions.

[0065] FIG. 2 is a schematic explanatory diagram showing the state of a coating film formed by a coating liquid prepared from a resin composition according to this embodiment (hereinafter, sometimes abbreviated as "coating film formed by this embodiment"). As shown in FIG. 2, the coating film formed by this embodiment is in a state in which hardened alumina cement hydrate is dispersed in a hardened product of an epoxy resin and an epoxy resin hardener. Also, a small amount of a neutralized product of a blocking agent and a base in a basic aqueous solution remains in the alumina cement hydrate. The amount of the neutralized product is very small and it is neutral or weakly alkaline, so it has almost no effect on the hardened product of the alumina cement hydrate or the epoxy resin.

[0066] The coating film formed by this embodiment as described above is not affected by humidity or temperature because the curing reaction does not involve water volatilization and the curing reaction proceeds inside the coating film, and the coating film is not easily affected by humidity or temperature, and is not easily thinned due to water volatilization. Therefore, the coating film formed by this embodiment significantly reduces problems that occur with general water-based paints, such as poor drying under high humidity conditions, delayed curing at low temperatures, and thinning of the coating film due to water volatilization.

[0067] Water-based epoxy resin paints are inevitably inferior in water resistance, but the base material of the resin composition according to this embodiment is composed of a water-insoluble raw material, and the curing agent is mixed with the base material, and as the hydration of alumina cement and neutralization of alkali proceed, the water-soluble amine becomes hydrophobic, and further, the water resistance of the resulting coating film is hardly reduced by the hardening caused by the reaction with the epoxy resin. According to the resin composition according to this embodiment, while inheriting the performance of the hardened product of the oil-based liquid epoxy resin paint whose viscosity is adjusted by an organic solvent, it is possible to adjust the viscosity with water instead of an organic solvent, and the volume reduction after hardening due to volatilization can be greatly suppressed. Therefore, the coating liquid according to this embodiment has a low viscosity, and the coating film of the coating liquid has a high solid content after hardening.

[0068] The coating film formed by this embodiment mainly exhibits the performance of the hardened epoxy resin. In addition, the alumina cement hydrate is dispersed as a hardened body inside the hardened epoxy resin, and the alumina cement hydrate functions as a filler, so that the coating film is expected to have excellent mechanical strength (e.g., abrasion resistance).

[0069] The resin composition according to the present embodiment is an aqueous agent containing no organic solvent in either the main agent or the auxiliary agent, and therefore has excellent handleability without being subject to various regulations under the Fire Service Act.

[0070] <Application to other uses> Due to its unique curing mechanism and characteristics, the resin composition according to the present embodiment can be used in applications other than coating applications, such as the applications listed below.

[0071] (Resin mortar material) By further blending coarse aggregate into the resin composition according to the present embodiment, it becomes possible to use it as a resin mortar material. In this case, it is preferable to blend the coarse aggregate after preparing a mixed liquid by mixing the main agent and the auxiliary agent. The resin mortar material obtained in this manner is excellent as a resin mortar material in that it has a property of having little volume reduction when hardened.

[0072] The coarse aggregate to be mixed when used as a resin mortar material may be contained in either the main agent or the auxiliary agent, or in both, as with the "other components" described above, or may be contained in an additive prepared separately.

[0073] The amount of coarse aggregate to be mixed depends on the particle size of the aggregate mixed depending on the required thickness, for example, if a thickness of about 5 mm is targeted, silica sand No. 5 or aggregate of a similar particle size should be used, and about 4 times the total amount of the main agent and auxiliary agent of the resin composition of this embodiment should be used by mass, and if a thickness of about 10 mm is targeted, silica sand No. 4 should be used, and about 5 times the total amount should be used by mass. Naturally, the amount of coarse aggregate may be adjusted or aggregates of each particle size may be used in combination depending on the properties expected of the resin mortar material, such as handleability, surface finish, and adhesion to the base material.

[0074] (Putty or adhesive) By further blending a thickener into the resin composition according to the present embodiment, it becomes possible to use it as a putty material or an adhesive. In this case, it is preferable to blend the thickener after preparing a mixed liquid by mixing the main agent and the auxiliary agent. The putty material or adhesive obtained in this way has a property of having little volume loss when hardened, so that it is excellent as a putty material because cracks and insufficient filling due to shrinkage are unlikely to occur when filling unevenness or gaps. Also, it is excellent as an adhesive because it is unlikely to cause insufficient adhesive strength between adherends due to shrinkage.

[0075] The type of thickener is not particularly limited, and any of the general thickeners used in preparing putty materials or adhesives can be used.

[0076] The amount of thickener to be added varies depending on the type and properties of the thickener, but from the viewpoint of imparting properties as a thickener and maintaining the functionality of the resin composition according to this embodiment, it is desirable for the amount to be within a range of 0 to 30 mass % in the coating liquid, and more preferably within a range of 0 to 20 mass %.

[0077] (Fiber reinforced plastics) The resin composition according to the present embodiment can be used as a fiber-reinforced plastic by further adding fibers. In this case, it is preferable to mix the main agent and the auxiliary agent to prepare a mixed liquid, and then impregnate the fibers with the mixed liquid. The fibers may be immersed in or added to the mixed liquid.

[0078] The resin composition according to the present embodiment has a low viscosity, so that it can be easily impregnated into fibers, and therefore is easy to process. In addition, the resin composition according to the present embodiment has a property of causing little volume loss when cured, so that peeling between the resin composition and fibers is unlikely to occur, and strength can be easily ensured.

[0079] The fibers contained in the resin composition according to the present embodiment may be general reinforcement fibers such as carbon fibers, glass fibers, boron fibers, aramid fibers, etc., as well as general fibers such as nylon, polyester, hemp, cotton, etc. The fibers may be woven or nonwoven fabric, and may be formed by impregnating an aggregate of disorganized fiber particles with the resin composition or dispersing fiber particles in the resin composition. EXAMPLES

[0080] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0081] (Example 1: Example of paint application) Example 1 is an example of a trowel-applied floor paint (finishing material).

[0082] <Preparation of Coating Solution of Example 1> (1) Preparation of the base agent As the epoxy resin, a self-emulsifying epoxy resin, AW-1000 (a bisphenol A type liquid epoxy resin, solid content 100%, epoxy equivalent 215, manufactured by Chori GLEX Co., Ltd.) was used. In addition, Exalt (Kerneos) was used as the alumina cement. Exalt is a water-dispersed product in which the hydration reaction is blocked.

[0083] In addition, ET base color (product name "ET 3W 114 White", a white pigment manufactured by Dainichi Seikagaku Kogyo Co., Ltd.) was blended as a pigment, ERISYS AED-16L (manufactured by Huntsman Advanced Materials, 1,6-hexanediol glycidyl ether) was blended as a diluent, and FLOWLEN AC-326F (manufactured by Kyoeisha Chemical Co., Ltd., vinyl ether polymer) was blended as a surface conditioner (defoamer). The composition of the base material is as shown in Table 1 below.

[0084] [Table 1]

[0085] All of the components (total amount 100) other than the alumina cement in the above formulation were mixed and stirred until uniform, and then the alumina cement was added to prepare the base material of Example 1.

[0086] In this embodiment, only the white ET base color is used as a pigment, but to obtain a desired color, other ET base colors can be used alone, or multiple ET base colors can be mixed by adjusting the color type and amount. If the finished state, such as color development, is not as desired, additives such as dispersants, color separation inhibitors, and defoamers can be added to adjust the quality to the required level. In terms of the stability of the composition, additives that are not basic are preferred, taking into account the hydration reaction block state of the alumina cement.

[0087] When mixing ET base colors in the formulation of this embodiment, the total blend ratio of all ET base colors used in the mixing is 10, and the finish state of the coating can be adjusted by adding 0.5 to 1 part by mass of AFCONA6226 (manufactured by Afcona Japan Co., Ltd.) and 0.3 to 0.8 parts by mass of Floren NAF250 (manufactured by Kyoeisha Chemical Co., Ltd.) as additives in an external ratio of 150 (parts by mass).

[0088] (2) Preparation of auxiliary agents The auxiliary agent of Example 1 was prepared by adding 10 parts by mass of a 5% by mass aqueous solution of sodium hydroxide to 30 parts by mass of Fujicure 8167-D (manufactured by T&K TOKA Corporation, modified amine-based curing agent, amine value: 395 to 435, standard compounding equivalent: 85 g / eq) as an epoxy resin curing agent, and mixing uniformly.

[0089] (3) Preparation of coating solution The main agent and auxiliary agent of each color obtained as above were mixed so that the mixing ratio of the main agent:auxiliary agent=15:4, and the mixture was thoroughly stirred to be homogenous using a propeller type stirrer to prepare the coating solution of Example 1. The specific gravity of the obtained coating solution was 1.35.

[0090] (4) Painting and evaluation testing a) Measurement of coating thickness and gloss 10.5 g (1 kg / m2) of the coating solution of Example 1 was applied to a glass plate (float glass plate, 70 x 150 x 3 mm) with a spatula under an environment of 23°C temperature and 50% RH humidity so that the film thickness immediately after application (film thickness before curing) was theoretically 0.75 mm, and the plate was left to stand under the same environment for 20 hours. The glossiness (JIS K5600-4-7) of the formed coating film was measured at three points, and the average values ​​were 62.5 / 96.3 / 91.0 at measurement angles of 20° / 60° / 85°, respectively, and the coating surface was glossy.

[0091] The formed coating film was peeled off from the glass plate, its cross section was cut out with a cutter, and the exposed cross section of the coating film was photographed under an optical microscope (100x). The optical microscope photograph of the cross section of the coating film is shown in Figure 3. In the photograph of Figure 3, the layer in the center of the image is the cross section of the coating film, and the lower surface is the surface that was attached to the glass plate. In addition, in the photograph of Figure 3, there is empty space above and below the coating film. When the film thickness was measured from the cross section of the coating film in the photograph, it was approximately 0.76 mm, and the theoretical value and the measured value were almost the same.

[0092] b) Hardness and thickness reduction of the coating film (cured film) 18.0 g of the coating solution of Example 1 (mass that would give a thickness of 4 mm calculated from the specific gravity) was poured into a polypropylene mold with a diameter of 65 mm and a depth of 4 mm under an environment of 23°C temperature and 50% RH humidity, and allowed to stand for 20 hours under the same environment. The mass of the resulting cured film was measured and found to be 18.0 g (mass loss 0%). The durometer hardness of this cured film (type D durometer hardness according to JIS K7215; the same applies below) was HDD65, which was sufficient hardness for a coating film.

[0093] The samples left under the above conditions were further left to stand (cured) for one month under the same environment (23°C, 50%RH). The mass of the cured film after standing (curing) was measured and found to be 17.6g on average (mass reduction 2.22%). This confirmed that most of the coating liquid constituted the cured film.

[0094] c) Reduction in hardness and thickness of coating film (cured film) in high humidity environment 18.2 g of the coating solution of Example 1 was poured into a mold with a diameter of 65 mm and a depth of 4 mm under an environment of a temperature of 23° C. and a humidity of 100% RH, and left to stand under the same environment for 20 hours. The mass of the obtained cured film was measured and found to be 18.2 g (mass loss 0%). The durometer hardness of this cured film was HDD65, and even under a high humidity environment, the result was the same as that under an environment of a temperature of 23° C. and a humidity of 50% RH.

[0095] (Example 2: Putty and adhesive applications) To the coating solution of Example 1, 15% by mass of a zeolite thickener, Milcon MS-2 (manufactured by Showa KDE Co., Ltd.), was added and thoroughly stirred. The mixture had good mixability, and the composition of Example 2, which can be used as an adhesive or putty material with good handling properties, was obtained.

[0096] <Adhesive evaluation test> The adhesive strength of the composition of Example 2 as an adhesive was evaluated in accordance with the coating floor adhesion test method NNK-005 (2020) (established by the Technical Committee of the Japan Coating Floor Industry Association). Note that the coating floor adhesion test method NNK-005 is basically the same as the test method specified in JIS K5600-5-7 (Mechanical properties of coating film adhesion (pull-off method)) (JIS uses a cylindrical jig, whereas a square jig is used).

[0097] A concrete slab (30cm x 30cm x 6cm) as specified in JIS A 5371 "Precast unreinforced concrete products" that had been thoroughly treated to remove laitance by sanding with #40 grit paper was bonded to a steel jig (4cm x 4cm) for adhesive strength testing using the composition of Example 2 as an adhesive. The amount of the composition of Example 2 applied (before hardening) was 1.2 kg / m 2 The test was carried out in an environment with a temperature of 23°C and a humidity of 50% RH.

[0098] After confirming that the adhesive had fully hardened three days after bonding, a cut was made around the steel jig, a testing machine was attached, and the maximum tensile load was measured. The test was carried out five times, and the fracture surface and adhesive strength were calculated. The test results showed that the adhesive had delamination with the steel material accompanied by cohesive failure of the substrate, and the adhesive strength (unit: N / mm 2 ) was 1.46 on average (minimum 1.04, maximum 2.05), confirming a certain adhesive strength.

[0099] <Evaluation test as putty material> The composition of Example 2 as a putty was applied with a spatula at a rate of 2 kg / m2 onto the surface of the same concrete flat plate (30 cm x 30 cm x 6 cm) as used in the <Evaluation test as an adhesive>. 2This was done in an environment with a temperature of 23°C and a humidity of 50%.

[0100] After 4 hours had passed since application under the same environment, and it was confirmed that the surface had hardened to the extent that it could be overcoated, the coating solution of Example 1 was applied using a spatula so that the film thickness immediately after application (film thickness before hardening) was theoretically 0.75 mm, and the surface was left to stand for 20 hours. All steps from application to standing were carried out under the same environment (temperature 23°C, humidity 50% RH).

[0101] When the hardened coating surface was observed, it was found to be smooth and free of dents or pinholes caused by the base coat.

[0102] The adhesion between layers was confirmed by the same test method as in the <Evaluation test as an adhesive>. However, the square jig was attached to the surface of the coating film made from the coating liquid of Example 1 with an epoxy resin adhesive (product name "Bond Quick Mender", manufactured by Konishi Co., Ltd.). The test was carried out five times, and the fracture surface and adhesive strength were calculated. All test results showed cohesive failure of the test substrate, and the adhesive strength (unit: N / mm 2 ) was 3.76 on average (minimum 3.52, maximum 4.09), confirming that it has high performance as a putty material. [Industrial Applicability]

[0103] As explained above, the two-component epoxy resin composition of the present invention is preferably used as a paint because it was developed for this purpose, but it can also be used as a resin mortar material by adding coarse aggregate, as a putty material or adhesive by adding a viscosity agent, and as a fiber-reinforced plastic by impregnating fibers. Of course, the two-component epoxy resin composition of the present invention is also used in applications other than paint.

Claims

1. A base material including at least an epoxy resin, water, and alumina cement whose hydration reaction has been blocked; an epoxy resin curing agent for curing the epoxy resin, and a sub-agent including a basic aqueous solution for unblocking the hydration reaction of the alumina cement; A two-component epoxy resin composition comprising:

2. 2. The two-component epoxy resin composition according to claim 1, wherein the coating liquid prepared by mixing the main agent and the auxiliary agent has a water content of 5 to 30 mass % and a cured product-forming component content of 85 to 100 mass % in the coating liquid.

3. 2. The two-component epoxy resin composition according to claim 1, wherein the epoxy resin is a self-emulsifying liquid epoxy resin.

4. 2. The two-part epoxy resin composition according to claim 1, wherein the epoxy resin hardener is a polyamine.

5. The two-component epoxy resin composition according to claim 1, which is used as a coating material.

6. 2. The two-component epoxy resin composition according to claim 1, further comprising coarse aggregate, and used as a resin mortar material.

7. 2. The two-component epoxy resin composition according to claim 1, further comprising a thickener, and used as a putty or adhesive.

8. The two-component epoxy resin composition according to claim 1, further comprising fibers and used as a fiber-reinforced plastic.

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