JP2014196458A - Conductive coating-floor paint, conductive coated floor, and building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide conductive coating-floor paint capable of forming a layer of conductive coated floor doubling the functions of undercoat layer and middle coat layer for the purpose of work period shortening, conductive coated floor comprising layer composed of said conductive coating-floor paint, and building such as factory comprising said conductive coated floor.SOLUTION: The conductive coating-floor paint is obtained by blending, into solventless epoxy resin, 10 or more pts.mass and 25 or less pts.mass of columnar expanded graphite into 100 pts.mass of said epoxy resin. The conductive coated floor comprises layer composed of said conductive coating-floor paint. The conductive coated floor preferably is formed of said layer as primer layer, and on top of it a surface layer composed of coating-floor paint comprising epoxy resin, conductive material, dispersant, and antisettling agent. The building comprises said conductive coated floor.

Description

  The present invention relates to a conductive floor coating, a conductive floor including a layer formed by applying the conductive floor coating, and a building including the conductive floor.

As floors for various production facilities such as factories, synthetic resin-based floors such as epoxy resins are widely used.
Such a synthetic resin-based floor is generally an insulator with high electrical resistance, and it is easy to be charged when an operator walks on the floor. In addition, static electricity accumulated in the floor and the worker itself is leaked due to charging. There is a problem that it is difficult to do.

For this reason, for example, clean rooms used in the manufacturing process of electronic components such as semiconductor elements, floors that require a high level of dust-proof performance, or the handling of organic solvents and gases, etc. must be highly prevented. The coated floor applied to the floor to be used is required to impart conductivity and improve the antistatic performance.
It has been reported that various conductive materials may be mixed into a synthetic resin in order to impart conductivity to a painted floor based on a synthetic resin that is an insulator to form a so-called conductive coated floor ( For example, Patent Documents 1 and 2).

In addition, in order to stabilize the conductivity of the conductive coating floor, the conductive coating floor is mixed with an undercoat layer (primer layer) made of a synthetic resin and a conductive material, respectively, on a concrete ground or the like. In general, a three-layer structure in which an applied intermediate coating layer (conductive primer layer) and a colored top coating layer (surface layer) are sequentially laminated is used.
The application of each layer and the curing of the synthetic resin each require approximately one day, and therefore, the construction of the conductive coating floor having a three-layer structure requires a total period of three days.

  However, for example, in order to construct a three-layered conductive coated floor on the floor of a factory in operation, the operation is stopped for 3 days from the viewpoint of the productivity of products produced in the factory. It is not preferable, and shortening of the construction period has been demanded.

JP 2007-262254 A JP2012-126817A

The undercoat layer is used to add adhesive strength to the conductive coating floor, and to correct the foundation by filling in the unevenness, dents, and scratches of the foundation. It is often formed by a small solvent-free epoxy resin.
The intermediate coating layer is formed by, for example, applying a solvent-based epoxy resin such as water mixed with a conductive material onto the undercoat layer, and then drying to remove water and curing the epoxy resin. It is common.

In the intermediate coating layer, the physical distance between the blended conductive materials is reduced by the volume reduction during drying and curing, and the conductivity of the entire layer is expressed. Therefore, even if the conductive material is blended in a range that does not impede the flow of the coating material for the intermediate coating layer, good physical conductivity is imparted to the formed intermediate coating layer by reducing the physical distance between the conductive materials due to volume reduction. it can.
It is conceivable to shorten the construction period by combining these two layers into one layer.

However, as described above, the coating for the intermediate coating layer has a large volume reduction rate at the time of drying and curing, mainly from the viewpoint of imparting electrical conductivity. It cannot be combined with the function of the undercoat layer.
Further, as described above, the undercoat layer is made of an epoxy resin that is a solvent-free system and hardly decreases in volume when cured in order to provide a function of correcting the base. Even when the same amount of conductive material is blended as in the case, the physical distance between the conductive materials is not reduced at the time of curing, and hence good conductivity cannot be expressed in the intermediate coating layer.

In order to secure an appropriate physical distance, it is conceivable to increase the blending amount of the conductive material, but in that case, the viscosity becomes too high, and it becomes difficult to mix and stir. Then, it becomes impossible to prepare a uniform paint in which the conductive material is uniformly dispersed.
An object of the present invention is to provide a conductive coating floor coating that can form a conductive coating floor layer that also functions as an undercoat layer and an intermediate coating layer for shortening the work period, and a conductive layer provided with a layer made of such a conductive coating floor coating. Another object of the present invention is to provide a building such as a factory equipped with a conductive coating floor and the conductive coating floor.

The present invention relates to a conductive floor coating characterized by comprising 10 mass parts or more and 25 mass parts or less of columnar expansive graphite per 100 mass parts of the epoxy resin in a solvent-free epoxy resin. is there.
Conventionally, for example, spherical artificial graphite has been used as the conductive material for the intermediate coating layer. Therefore, even if the same amount of conductive material as in the case of the intermediate coating layer is blended with the coating for the undercoat layer made of an epoxy resin that does not substantially reduce the volume upon curing in a solvent-free system, good conductivity can be imparted. could not.

  On the other hand, columnar expansive graphite used as a conductive material in the conductive floor coating of the present invention, as its name suggests, expands graphite into a columnar shape, and the dimensions in the length direction of the column are other. Because it is larger than the dimension in the direction, unlike conventional spherical ones etc., it may be blended in the above proportion in an epoxy resin that is solvent-free and hardly decreases in volume when cured. Based on the shape characteristics, an appropriate physical distance can be secured between the expanded graphites adjacent to each other, or a layer having good conductivity can be formed.

Therefore, such a layer can be combined with the functions of the conventional undercoat layer and intermediate coat layer, thereby reducing the total number of layers of the conductive coating floor and shortening the construction period.
In the present invention, the proportion of the expanded graphite is limited to the above range for the following reason.
That is, when the blending ratio is less than 10 parts by mass per 100 parts by mass of the solventless epoxy resin, even if columnar expanded graphite is used, the effect of imparting good conductivity to the layer is obtained due to its shape characteristics. Absent.

On the other hand, when the amount exceeds 25 parts by mass, the viscosity becomes too high to be mixed and stirred, and a uniform paint in which the conductive material is uniformly dispersed cannot be prepared.
On the other hand, by setting the blending ratio of the expanded graphite within the range described above, the expanded graphite can be easily and uniformly dispersed in the epoxy resin to prepare a conductive floor coating, and the conductive coating Good conductivity can be imparted to the floor coating layer.

In consideration of further improving this effect, the blending ratio of the expanded graphite is preferably 15 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the solventless epoxy resin even in the above range. .
The present invention is a conductive floor including at least a layer formed by applying the conductive floor coating of the present invention on a base and curing an epoxy resin.

Such a conductive coating floor of the present invention comprises a layer having the functions of a conventional undercoat layer and an intermediate coating layer made of the conductive coating floor paint of the present invention, so that the total number of layers can be reduced. The construction period can be shortened.
In particular, when the conductive coated floor of the present invention has a two-layer structure in which such a layer is a single primer layer and a surface layer (overcoat layer) is further laminated on the primer layer, the conventional three-layer structure is used. The construction period can be shortened to 2/3 compared to the conductive coating floor.

In particular, the surface layer includes an epoxy resin and a main agent containing a conductive substance, 0.25 parts by mass to 5 parts by mass of a dispersant, and 0.25 parts by mass to 0.75 parts by mass per 100 parts by mass of the main agent. It is preferable to form a coating layer for the surface layer, which is blended with a part or less antisettling agent, on the primer layer and cure the epoxy resin.
By forming the surface layer with an epoxy resin excellent in affinity and adhesion to the primer layer, the strength and durability of the conductive coating floor having a two-layer structure can be improved.

Moreover, the electroconductivity as the whole electroconductive coating floor can also be stabilized by mix | blending an electroconductive substance with a surface layer.
Further, when a dispersant is added to the coating for the surface layer, the dispersibility of the conductive material can be improved, and the variation in the resistance value of the surface layer can be minimized.
However, when a dispersant is blended, the viscosity of the paint floor coating decreases, and a conductive material having a large specific gravity tends to settle, sticking as an agglomerate to the bottom of the can where the paint floor paint is stored, so-called hard caking. And thereby cause poor curing of the paint floor during construction.

On the other hand, when the anti-settling agent is used in combination with the dispersant, the settling of the conductive substance can be suppressed, and a surface layer having no variation in resistance value can be formed without causing poor curing due to the occurrence of hard caking.
The present invention is a building comprising the conductive coating floor of the present invention.
Such a building of the present invention comprises the conductive coating floor of the present invention, and the conductive coating floor is made of the conductive coating floor coating of the present invention containing an epoxy resin which is a solvent-free system and hardly reduces its volume when cured. Therefore, there is an advantage that the strength of the floor and the whole building is improved.

  According to the present invention, an electrically conductive floor coating that can form a conductive floor layer that also functions as an undercoat layer and an intermediate layer for shortening the construction period, and a conductive layer provided with a layer made of such a conductive floor floor coating. It is possible to provide a building such as a factory equipped with a conductive coating floor and the conductive coating floor.

<Conductive floor paint>
The conductive floor coating of the present invention is characterized by comprising 10 parts by mass or more and 25 parts by mass or less of columnar expandable graphite per 100 parts by mass of the epoxy resin in a solventless epoxy resin. Is.
(Epoxy resin)
The epoxy resin is liquid at the construction environment temperature (especially room temperature) of the conductive coating floor, so it does not require a solvent such as water, and it has various liquids suitable for the correction of the groundwork due to small shrinkage during drying and curing. An epoxy resin of the above type, particularly a so-called two-component curing type epoxy resin that is liquid and is cured by reaction with a curing agent is preferable.

Examples of such epoxy resins include Gripcoat (registered trademark) C301, C312 and C355 manufactured by Sumitomo Rubber Industries.
(Curing agent)
As the curing agent for the two-component curing type epoxy resin, various curing agents capable of curing the epoxy resin at the construction environment temperature (particularly room temperature) of the conductive coated floor can be used.

  Examples of the curing agent include aliphatic amines such as diethylenetriamine and triethylenetetramine, and modified products thereof, aromatic amines such as m-phenylenediamine and diaminodiphenylmethane, and modified products thereof, phthalic anhydride, hexahydrophthalic acid, and the like. One type or two or more types of acid anhydrides such as anhydride, pyromellitic acid anhydride, polysulfide, acid amide, thiocol and the like can be mentioned.

Specific examples of the curing agent include Gripcoat H312F (modified amine type), H326, H355, and the like manufactured by Sumitomo Rubber Industries, Ltd.
(Columnar expanded graphite)
As the columnar expanded graphite, any of various columnar expanded graphites obtained by thermally expanding graphite after interlayer treatment can be used.

Such expanded graphite has a column length of 20 μm or more, particularly preferably 80 μm or more, and is preferably 200 μm or less, particularly preferably 120 μm or less.
If the length is less than this range, there is a possibility that the effect of imparting good conductivity to the layer made of the conductive coating floor paint of the present invention may not be sufficiently obtained based on its shape characteristics.
On the other hand, the bonding force between the layers of graphite constituting the expanded graphite is not so strong and is easily broken in the middle, so it is not easy to produce long expanded graphite exceeding the above range.

Examples of the columnar expanded graphite include BSP-100A (length: 100 μm) manufactured by Shin-Etsu Chemical Co., Ltd.
As described above, the proportion of the expanded graphite is limited to 10 parts by mass or more and 25 parts by mass or less per 100 parts by mass of the solventless epoxy resin.
If the blending ratio is less than this range, even if columnar expanded graphite is used, the effect of imparting good conductivity to the layer cannot be obtained due to its shape characteristics.

On the other hand, when it exceeds the range, the viscosity becomes too high, and it becomes difficult to mix and stir, and a uniform paint in which the conductive material is uniformly dispersed cannot be prepared.
In contrast, by setting the proportion of expanded graphite within the above range, the expanded graphite can be easily and uniformly dispersed in the epoxy resin to prepare a conductive coated floor coating, and the conductive coated floor coating can be prepared. Good conductivity can be imparted to the layer comprising

In consideration of further improving this effect, the blending ratio of the expanded graphite is preferably 15 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the solventless epoxy resin even in the above range. .
In the case of a two-component curing type epoxy resin, the mass part of the epoxy resin serving as a reference for the blending ratio is the mass part of only the epoxy resin not including the curing agent.

(Other)
In the conductive floor coating of the present invention, a reactive diluent for adjusting the viscosity and fluidity, a catalyst for accelerating the curing reaction of the epoxy resin, and the like are further blended at an appropriate ratio. Also good. Moreover, when the electroconductive coating floor of this invention is a single layer so that it may demonstrate below, in order to color the said layer, you may mix | blend colorants, such as a pigment.

(Conductive floor paint)
When the epoxy resin is a two-component curing type epoxy resin that cures by reaction with a curing agent, the conductive coating floor coating is configured as a two-component type of a main agent in which expanded graphite is dispersed in an epoxy resin and a curing agent. And it is preferable to mix | blend a main ingredient and a hardening | curing agent in a predetermined ratio in a construction site, and to apply | coat on a foundation | substrate.

<Conductive coated floor>
The conductive floor of the present invention is characterized by including at least a layer formed by applying the conductive floor paint of the present invention on a base and curing an epoxy resin.
The configuration of the present invention is applicable to various conductive coating floors having a single layer or a multilayer structure.

That is, the conductive coating floor may be formed by a single layer formed by applying and curing the conductive coating floor coating of the present invention, or a multi-layered conductive coating floor including such a layer may be formed. Good.
However, the conductive coated floor of the present invention preferably has a two-layer structure in which a surface layer (overcoat layer) is further laminated on a conventional single-layer primer layer that also serves as an undercoat layer and an intermediate coat layer.

In this case, the construction period can be shortened to 2/3 compared to the conventional conductive coating floor having a three-layer structure. In addition, by laminating the surface layer on the primer layer, the overall conductivity of the conductive coating floor can be stabilized.
(Surface layer)
The surface layer can be formed in a conventional manner. That is, the surface of a two-part room temperature curing type, one-part moisture curing type, etc., in which a conductive material, a coloring agent such as a pigment is blended in a synthetic resin excellent in affinity and adhesion to the primer layer, particularly an epoxy resin The surface layer can be formed by applying a floor coating for the layer on the primer layer and curing the epoxy resin.

In particular, the epoxy resin and the main agent containing a conductive substance are 0.25 parts by mass or more and 5 parts by mass or less of a dispersant, and 0.25 parts by mass or more and 0.75 parts by mass or less per 100 parts by mass of the main agent. It is preferable to form the surface layer using a coating for the surface layer containing an anti-settling agent.
When a dispersant is added to the coating for the surface layer, the dispersibility of the conductive material can be improved, and the variation in the resistance value of the surface layer can be minimized.

However, when a dispersant is blended, the viscosity of the paint floor coating decreases, and a conductive material having a large specific gravity tends to settle, sticking as an agglomerate to the bottom of the can where the paint floor paint is stored, so-called hard caking. This may cause poor curing of the paint floor during construction.
On the other hand, when the anti-settling agent is used in combination with the dispersant, the settling of the conductive substance can be suppressed, and a surface layer having no variation in resistance value can be formed without causing poor curing due to the occurrence of hard caking.

(Epoxy resin)
As an epoxy resin, as used in the conductive coating floor paint of the present invention, a solvent such as water is unnecessary because it exhibits a liquid state at the construction environment temperature (particularly room temperature) of the conductive coating floor, and is dried. In addition, various liquid epoxy resins suitable for the correction of the substrate because of small shrinkage at the time of curing, particularly so-called two-component curing type epoxy resins which are liquid and cure by reaction with a curing agent are preferable.

(Curing agent)
As the curing agent for the two-component curing type epoxy resin, the epoxy resin can be cured at the construction environment temperature (particularly room temperature) of the conductive coating floor, similar to that used in the conductive coating floor coating of the present invention. Various curing agents that can be used can be used.
Examples of the curing agent include aliphatic amines such as diethylenetriamine and triethylenetetramine, and modified products thereof, aromatic amines such as m-phenylenediamine and diaminodiphenylmethane, and modified products thereof, phthalic anhydride, hexahydrophthalic acid, and the like. One type or two or more types of acid anhydrides such as anhydride, pyromellitic acid anhydride, polysulfide, acid amide, thiocol and the like can be mentioned.

(Conductive substance)
As the conductive substance, for example, one kind of conductive metal oxide such as conductive zinc white (zinc oxide, ZnO), titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), etc. Or 2 or more types are mentioned.
Since these conductive metal oxides usually exhibit white or light color, the appearance and appearance of the surface layer can be improved.

Moreover, as a conductive substance, you may use together 1 type (s) or 2 or more types, such as a carbon fiber and a metal fiber, for example with a conductive metal oxide.
The blending ratio of the conductive substance is preferably 10 parts by mass or more, particularly 20 parts by mass or more, and preferably 100 parts by mass or less, particularly 80 parts by mass or less, per 100 parts by mass of the epoxy resin.

When the blending ratio is less than this range, the resistance value of the surface layer cannot be lowered sufficiently, and there is a possibility that a good antistatic function cannot be imparted to the conductive coating floor.
On the other hand, when it exceeds the range, the blending ratio of the epoxy resin is relatively reduced, so that the strength and durability of the surface layer, and thus the conductive coated floor, may be lowered.
On the other hand, by setting the blending ratio of the conductive substance within the range described above, it is possible to impart a further better antistatic function to the conductive coated floor while preventing a decrease in strength and durability.

In addition, a mixing | blending ratio should just make the total mixing | blending ratio in said range, when using 2 or more types of electroconductive substances together.
(Dispersant)
As the dispersant, a dispersant having both a function as a wetting agent for wetting the conductive substance with the epoxy resin and a function as a dispersing agent for dispersing the conductive substance in the epoxy resin can be used.

In particular, when a conductive metal oxide is mainly used as the conductive material, a copolymer having an acid group in the molecule and an acid value of 50 mgKOH / g or more is preferable.
Such copolymers exhibit acidity and adsorb more strongly to conductive metal oxides that are basically basic than other dispersants such as copolymers with acid values below this range, so as wetting agents The conductive material including the conductive metal oxide is well wetted by the epoxy resin and can be dispersed as evenly as possible in the epoxy resin. Therefore, the dispersibility of the conductive material can be improved, and the variation in the resistance value of the surface layer can be minimized.

Further, since such a copolymer is basically colorless and transparent, as described above, the appearance and appearance of the surface layer can be improved in combination with the conductive metal oxide usually exhibiting white or light color.
Examples of the acid group include a phosphoric acid group and a carboxylic acid group.
The copolymer preferably has an acid value of 70 mgKOH / g or more, particularly 120 mgKOH / g or more in consideration of further improving the effects described above. The upper limit of the acid value is not particularly limited, but is preferably 140 mgKOH / g or less, particularly preferably 130 mgKOH / g or less.

  Examples of such a copolymer include BYK (registered trademark) -W9010 [acid group: phosphoric acid group, acid value: 129 mgKOH / g, nonvolatile content: 100%], BYK-W995 [acid group: manufactured by Big Chemie Japan Co., Ltd.]. Phosphoric acid group, acid value: 53 mg KOH / g, nonvolatile content: 53%], BYK-W996 [acid group: phosphoric acid group, acid value: 71 mg KOH / g, nonvolatile content: 52%], DISPERBYK (registered trademark) -110 [Acid group: phosphate group, acid value: 53 mg KOH / g, nonvolatile content: 52%], DISPERBYK-111 [acid group: phosphate group, acid value: 129 mg KOH / g, nonvolatile content: 95%], etc. Or 2 or more types are mentioned.

The blending ratio of the dispersant is preferably 0.25 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the main agent containing the epoxy resin and the conductive material.
When the blending ratio is less than this range, there is a possibility that the effect of improving the dispersibility of the conductive material and reducing the variation in the resistance value of the surface layer may not be sufficiently obtained.
On the other hand, when the range is exceeded, an excessive dispersant may bleed on the surface of the surface layer, and the appearance and appearance of the surface layer may be impaired.

On the other hand, by making the blending ratio of the dispersant within the above range, the dispersibility of the conductive substance is improved while maintaining the appearance and appearance of the surface layer, and the resistance value of the surface layer is improved. The variation can be further reduced.
(Anti-settling agent)
Examples of the anti-settling agent include various anti-settling agents that can control the rheology of the non-aqueous paint to prevent the solid content, that is, the conductive material from settling.

Examples of the anti-settling agent include a solution in which modified urea is dissolved in N-methylpyrrolidone. Specific examples thereof include at least one of BYK-410 and BYK-411 manufactured by BYK Chemie Japan Co., Ltd. Species are mentioned.
The blending ratio of the anti-settling agent is preferably 0.25 parts by mass or more and 0.75 parts by mass or less per 100 parts by mass of the main agent containing the epoxy resin and the conductive substance.

If the blending ratio is less than this range, the effect of suppressing the sedimentation of the conductive substance becomes insufficient, and there is a risk of causing poor curing due to the occurrence of hard caking.
On the other hand, if the range is exceeded, the conductivity of the surface layer may be insufficient.
On the other hand, by setting the blending ratio of the anti-settling agent in the above range, it is possible to more reliably prevent poor curing due to the occurrence of hard caking while maintaining the conductivity of the surface layer well.

(Other)
For coatings for the surface layer, coloring agents such as pigments for coloring the surface layer, reactive diluents for adjusting the viscosity and fluidity of the coating layer, or curing of epoxy resin You may mix | blend the catalyst for promoting reaction, etc. in a suitable ratio.
(Coating floor paint)
When the epoxy resin is a two-component curing type epoxy resin that cures by reaction with a curing agent, the floor coating for the surface layer contains an electrically conductive substance, a dispersant, an anti-settling agent, a colorant and the like on the epoxy resin. It is preferable to configure as a two-component type of a blended main agent and a curing agent, blend the main agent and the curing agent at a predetermined ratio at the construction site, and apply the mixture onto the primer layer.

(Resistance value)
The resistance value of the surface of the conductive coated floor having a two-layer structure of the primer layer and the surface layer is preferably 1.0 × 10 ⁴ Ω or more, particularly preferably 7.5 × 10 ⁵ Ω or more, and 1.0 × 10 6 ^It is preferably ⁸ Ω or less, particularly 3.5 × 10 ⁷ Ω or less.
In order to keep the resistance value below this range, (1) increase the proportion of expanded graphite in the primer layer, (2) make the surface layer thinner, or (3) mix the conductive material in the surface layer. In the case of (1), the flow of the conductive floor paint is obstructed, making it difficult to apply evenly on the base, or correcting the base is not easy. There is a risk. Also, in the case of (2) and (3), the durability of the surface layer is reduced, and in the case of (2), the effect of stabilizing the overall conductivity of the conductive coated floor by providing the surface layer May not be sufficiently obtained.

On the other hand, if the resistance value exceeds the range, the effect of preventing the charging or quickly leaking the static electricity accumulated by charging by providing the conductive floor with appropriate conductivity is sufficient. May not be obtained.
The thickness of both layers is not particularly limited, but the thickness of the primer layer is preferably 0.2 kg / m ² or more in terms of the coating amount per unit area of the conductive coating floor coating used as the base layer, It is preferably 0.5 kg / m ² or less.

  If the coating amount is less than this range, the primer layer is too thin, and by forming the primer layer, the conductive coating floor is imparted with appropriate conductivity to prevent charging or to prevent static electricity accumulated by charging. There is a possibility that the effect of promptly leaking may not be obtained sufficiently. In addition, there is a possibility that the effect of correcting the base by filling the base with unevenness, dents, and scratches may not be obtained while forming the primer layer to add adhesive strength.

Further, even if the coating amount exceeds the range, not only the effect is not obtained, but also a large amount of conductive coating floor paint is consumed, which may lead to an increase in cost of the conductive coating floor.
The thickness of the surface layer is preferably 0.5 kg / m ² or more in terms of the coating amount per unit area when the underlying paint is a solventless system, and is 3.7 kg / m ² or less. Preferably there is. In the case of a solvent system, the solvent content may be added to this range.

If the coating amount is less than this range, the surface layer is too thin, the durability of the surface layer is lowered, and the effect of stabilizing the overall conductivity of the conductive coated floor by providing the surface layer is sufficiently obtained. There is a risk of not being able to.
On the other hand, when exceeding the range, the resistance value of the surface of the conductive coating floor exceeds the range described above, preventing charging by imparting appropriate conductivity to the conductive coating floor, There is a possibility that the effect of quickly leaking static electricity accumulated by charging may not be sufficiently obtained.

<building>
The building of this invention is equipped with the electroconductive coating floor of the said this invention, It is characterized by the above-mentioned.
As the building of the present invention, as mentioned above, especially a building such as a clean room factory used in the manufacturing process of electronic parts such as semiconductor elements, a floor where high dustproof performance is required on the floor, or an organic solvent, Examples include buildings that require a high level of prevention of static electricity on the floor, such as factories that handle gas.

Each of the following operations and tests was carried out in a normal temperature and humidity environment with a temperature of 23 ° C. and a relative humidity of 50%.
Example 1
<Conductive floor paint>
(Main agent)
Solvent-free epoxy resin [Gripcoat (registered trademark) C312 manufactured by Sumitomo Rubber Industries, Ltd.] 100 parts by mass, columnar expanded graphite [BSP-100A manufactured by Shin-Etsukasei Co., Ltd., length: 100 μm] Mix 10 parts by mass and stir for 2 minutes using a general-purpose stirrer (trade name Power Mixer PM-850 manufactured by Ryobi Corporation, blade diameter: φ150 mm). The main ingredient of the floor paint was prepared.

(Curing agent)
As the curing agent, a modified amine curing agent [Gripcoat H312F manufactured by Sumitomo Rubber Industries, Ltd.] was prepared.
<Primer layer>
40 mass parts of hardening | curing agents were mix | blended with the said main ingredient per 100 mass parts of the said main ingredients, and it stirred and prepared the conductive coating floor coating used as the origin of a primer layer.

Then, this conductive coating floor coating was applied to the surface of the base so that the coating amount per unit area was 0.33 kg / m ^2, and allowed to stand for 24 hours to be cured to form a primer layer.
<Coating floor paint for surface layer>
(Main agent)
The main agent includes an epoxy resin, a main agent containing 25 parts by mass of conductive zinc white per 100 parts by mass of the epoxy resin, 0.5 parts by mass of carbon fiber, and 1.4 parts by mass of metal fiber [Sumitomo Rubber Industries, Ltd. ) Grip Coat C503].

(Curing agent)
As a curing agent, a modified aliphatic polyamine curing agent [Gripcoat H506S manufactured by Sumitomo Rubber Industries, Ltd.] was prepared.
<Surface layer>
25 parts by mass of a curing agent was blended with 100 parts by mass of the main agent in the above-mentioned main agent, and the mixture was stirred to prepare a coating floor coating that becomes the basis of the surface layer.

And this coating floor coating was apply | coated so that the application quantity per unit area might be 1 kg / m < ² > on the above-mentioned primer layer, and it left still for 24 hours and hardened | cured, and the surface layer was formed.
<< Examples 2 to 4, Comparative Examples 1 and 2 >>
5 parts by mass (Comparative Example 1), 15 parts by mass (Example 2), 20 parts by mass (Example 3), and 25 parts by mass (implemented) with respect to 100 parts by mass of the solvent-free epoxy resin. A main component of a two-component curing type electrically conductive floor coating was prepared in the same manner as in Example 1 except that Example 4) was used.

In the same manner as in Example 1 except that this main agent was used, a conductive coating floor coating for a primer layer was prepared and applied on the base to form a primer layer. A surface layer was formed by applying the same floor coating for the surface layer as used.
Example 5
In the base agent of the same floor coating material for the surface layer used in Examples 1 to 4 (grip coat C503 manufactured by Sumitomo Rubber Industries, Ltd.) per 100 parts by mass of the main agent, the dispersant [BIC Chemie 1 part by mass of BYK-W9010 manufactured by Japan Co., Ltd. and 0.375 parts by mass of anti-settling agent [BYK-410 manufactured by Big Chemie Japan Co., Ltd.] described above were further stirred. 25 parts by mass of a curing agent [Gripcoat H506S manufactured by Sumitomo Rubber Industries, Ltd.] was mixed and stirred to prepare a coating for the surface layer.

And this coating floor coating was apply | coated on the same primer layer formed in Example 3, and the surface layer was formed.
<< Comparative Example 2 >>
When the proportion of expanded graphite is 30 parts by mass with respect to 100 parts by mass of the solvent-free epoxy resin, the viscosity is too high to uniformly stir, and the main component of the conductive coating floor coating for the primer layer Could not be prepared. Therefore, subsequent operation was not performed and the evaluation test mentioned later was not implemented.

<< Comparative Example 3 >>
In place of expanded graphite, spherical artificial graphite (average particle size: less than 10 μm) was blended in the same manner as in Example 1 except that 20 parts by mass per 100 parts by mass of the epoxy resin was blended. The main ingredient of the floor paint was prepared.
In the same manner as in Example 1 except that this main agent was used, a conductive coating floor coating for a primer layer was prepared and applied on the base to form a primer layer. A surface layer was formed by applying the same floor coating for the surface layer as used.

<Evaluation of resistance value>
The main ingredients of general-purpose epoxy resin-based paint floor coating [Gripcoat C450 manufactured by Sumitomo Rubber Industries, Ltd. and a curing agent [Gripcoat H506S manufactured by Sumitomo Rubber Industries, Ltd.] are blended at a predetermined ratio and stirred. This was coated on the surface of the plywood so that the coating amount per unit area was 1.2 kg / m ² and cured to prepare a base.

And on this foundation | substrate, each primer layer and the surface layer were formed in order in the procedure demonstrated in Examples 1-5 and Comparative Examples 1 and 3. FIG.
(Measurement and evaluation of resistance value)
The resistance value of the formed surface layer was measured using a resistance meter (terra ohm meter) manufactured by Midori Safety Co., Ltd. The measurement was performed while applying a voltage of 10 V or 100 V between the two electrodes while adhering the two electrodes attached to the resistance meter to the surface layer with a distance of 30 cm.

And the resistance value was evaluated according to the following criteria.
A: Resistance value was in the range of 7.5 × 10 ⁵ Ω or more and 3.5 × 10 ⁷ Ω or less. Very good.
○: The resistance value was 1.0 × 10 ⁴ Ω or more and 1.0 × 10 ⁸ Ω or less, and the range excluding the range of ◎. Good.

X: The resistance value was less than 1.0 × 10 ⁴ Ω or a range exceeding 1.0 × 10 ⁸ Ω. Bad.
(Evaluation of resistance variation)
The standard deviation σ of the logarithm of the resistance value measured as described above was calculated at a plurality of locations on the surface layer, and the variation in resistance value was evaluated according to the following criteria.

A: Standard deviation σ was 0.5 or less. Very good.
○: The standard deviation σ exceeded 0.5 and was 1 or less. Good.
X: The standard deviation σ exceeded 1. Bad.
<< Evaluation of adhesion
A concrete flat plate of 300 mm square and 60 mm thickness was prepared as a base model.

And on this foundation | substrate, each primer layer and surface layer are formed in order in the procedure demonstrated in Examples 1-5 and Comparative Examples 1 and 3, Furthermore, it is left still for one week and is cured, It is a 2 layer structure. A sample of a conductive floor was completed.
(Adhesive strength evaluation)
The Kenken adhesive strength test (Japan Paint Floor Industry Association test method NNK-005) was performed on the formed conductive coated floor sample, and the adhesive strength was evaluated according to the following criteria.

A: The substrate was destroyed. Good adhesion.
X: Interfacial peeling between the base and the primer layer, cohesive failure of the primer layer, or interfacial peeling between the primer layer and the surface layer. Adhesive strength is poor.
《Evaluation of impact resistance》
For the same conductive coated floor sample as the above adhesive strength evaluation, the falling ball test described in the Japanese coated floor industry association test method NNK-002 2000 "Coating floor impact strength test method" The impact resistance was evaluated based on the following criteria.

○: It was necessary to drop the ball twice or more before the coating film cracked or peeled off. Good impact resistance.
X: The coating film was cracked or peeled by one falling ball. Impact resistance failure.
"Comprehensive evaluation"
Of the above evaluations, at least one of the above evaluations was “×”, there was no “×”, and there was no “×”, all of which were “○” or “◎” and “○” were “○”, There was no “x”, and two “◎” and “◯” were evaluated as “◎”.

  The above results are shown in Tables 1 and 2.

From the results of Examples 1 to 5 and Comparative Example 3 in Tables 1 and 2, it is preferable for a primer layer made of a solventless epoxy resin by blending columnar expanded graphite instead of conventional spherical artificial graphite. It has been found that it is possible to impart a high conductivity.
However, from the results of Examples 1 to 5 and Comparative Example 1, it was found that the blending ratio of the expanded graphite needs to be 10 parts by mass or more per 100 parts by mass of the epoxy resin in order to obtain such an effect.

Further, from the results of Examples 1 to 5 and Comparative Example 2, in order to form a primer layer by preparing expanded primer by easily and uniformly dispersing expanded graphite in an epoxy resin, It turned out that it is necessary to make a mixture ratio into 25 mass parts or less per 100 mass parts of epoxy resins.
Furthermore, from the results of Examples 1 to 4, in order to further improve the effect of blending expanded graphite, the blending ratio of the expanded graphite is 15 parts by mass or more per 100 parts by mass of epoxy resin even in the above range. It was found that the content is preferably 20 parts by mass or less.

  From the results of Examples 3 and 5, it is preferable to add a dispersant and an anti-settling agent to the coating for the surface layer in order to minimize variations in the resistance value of the surface layer. understood.

Claims (6)

  A conductive floor coating comprising a solvent-free epoxy resin and 10 to 25 parts by mass of columnar expansive graphite per 100 parts by mass of the epoxy resin.   The conductive coating floor coating composition according to claim 1, wherein the expansive graphite is blended at a ratio of 15 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the epoxy resin.   An electroconductive floor, comprising at least a layer formed by applying the electroconductive floor paint according to claim 1 or 2 on a base and curing the epoxy resin.   The conductive coated floor according to claim 3, wherein the layer is a single-layer primer layer and has a two-layer structure in which a surface layer is further laminated on the primer layer.   The surface layer is composed of an epoxy resin and a main agent containing a conductive substance, 0.25 parts by mass to 5 parts by mass of a dispersant, and 0.25 parts by mass to 0.75 parts by mass per 100 parts by mass of the main agent. 5. The conductive coating floor according to claim 4, which is formed by applying a coating material for a surface layer containing an anti-settling agent in an amount of less than or equal to the amount on the primer layer and curing the epoxy resin.   A building comprising the conductive coated floor according to any one of claims 3 to 5.