JP2018171613A - Coating method for solvent-free urethane primer for hand coating - Google Patents

Abstract

The present invention provides adhesive performance and coating film strength equal to or better than those of solvent-based primers, and has a pot life of 40 minutes or more, and is particularly applicable to building materials such as concrete and mortar in sealed structures. It is to provide a coating method of a solvent-free urethane primer for hand coating. In the present invention, when a two-component reactive urethane primer is applied by hand to a construction material adherend such as concrete or mortar, the usable time is 40 minutes (reach 500 mPa · s) or more. For hand-painting, which includes a step of adjusting a urethane primer, a step of applying the liquid urethane primer to an adherend, and a step of overcoating and laminating a urethane coating material after the coated liquid urethane primer is cured. It is a coating method of a two-component reaction type solventless urethane primer. [Selection figure] None

Description

The present invention relates to a coating method of a two-component reaction type solventless urethane primer having a pot life suitable for hand coating. More specifically, in the adhesive performance with adherends such as concrete and mortar, the solvent-free urethane primer of the present invention can be used with an adherend equivalent to or better than the solvent-based primer while being solvent-free. The present invention relates to a coating method of a solvent-free urethane primer having excellent adhesion performance with a polyurea / polyurethane coating material (hereinafter referred to as polyurea coating material) as a top coating material.

In Japan, the primer used for the base of polyurea coating material in sealed rooms and pits (hereinafter referred to as concrete primer) is a water-based epoxy resin primer or water-based acrylic resin primer in consideration of the safety and environment of workers. Is widely used.

However, the water-based resin primer does not yet have a sufficient adhesive force with the adherend concrete or mortar as compared with the solvent-based primer. In particular, in a long-term water resistance test, warm water resistance test, etc., there was a problem that the adhesion performance with the adherend was extremely lowered and the coating film peeled off.

In addition to the above water-based resin primer, one-component moisture-curing urethane primer and epoxy resin primer are also used, but generally the curing speed is slow, so it takes a long time to apply the top coat material, and the primer itself Because of the relatively high viscosity, it was necessary to adjust the viscosity by adding an organic solvent.

Regarding the solvent-free urethane primer, technical information relating to a coating method of a steel material anticorrosion primer excellent in anticorrosion properties (water resistance, etc.) is disclosed (for example, Patent Document 1).

About the coating method of the primer for steel material corrosion prevention of patent document 1, it is the composition which assumed spray coating mainly with respect to the steel material of a to-be-adhered body. Since the main coat can be applied even at an interval of 5 minutes after primer coating, the painting process can be greatly shortened. Further, the addition of a phosphate of a metal of Group II and / or Group III of the periodic table adjusts the cathode peeling resistance, strength, initial adhesion, and water resistance adhesion of the primer coating film (layer).

In Patent Document 1, in order to enhance the adhesion between the primer and the steel material, the equivalent ratio (NCO group / OH group) is NCO excess, and the reaction is controlled within a certain range. In other words, by designing the equivalent ratio at the time of reaction to a high level, excess NCO groups react with moisture in the air, and by appropriately controlling the reaction with polyol and moisture, the primer layer and anticorrosive paint ( It was necessary to form a chemical bond between the two layers with the topcoat layer.

However, if the interval until the top coating after primer coating becomes possible during hand coating (hereinafter referred to as the coating interval) is shortened as described in Patent Document 1, bubbles generated during stirring are generated in the primer cured product. In addition, the isocyanate group cannot properly control the reaction between the base or moisture in the atmosphere and the polyol, causing foaming, and a stable continuous coating film as a primer cannot be obtained.

Therefore, it is possible to obtain a urethane primer coating film with satisfactory adhesion performance and coating strength for both the surface layer on the base material such as concrete and the polyurea coating layer. A suitable solventless primer coating method has not yet been obtained.

JP 11-319704 A

The present invention provides adhesive performance and coating strength equal to or better than those of solvent-based primers, has a pot life of 40 minutes or more, and is especially applied to building materials such as concrete and mortar for sealed structures. It is providing the coating method of the solventless urethane primer for coating.

In order to solve the above-mentioned problems, the inventors paid attention to the composition adjustment of a two-component reactive solvent-free urethane primer for hand-painting, and made intensive efforts to select the main agent and the curing agent composition. That is, by adjusting the primer composition to lower the viscosity of the urethane primer and further greatly extend the curing time, the coating interval also increased in parallel, making it easier to remove bubbles generated during stirring from the primer. In addition, by appropriately controlling the reaction between the isocyanate group and the substrate or moisture in the atmosphere and polyol, foaming due to moisture is suppressed, and as a result, a stable continuous coating film can be obtained as a primer. It came to complete the coating method of solvent-free urethane primer.

That is, the present invention provides a step of adjusting a liquid urethane primer having a usable time of 40 minutes (reaching 500 mPa · s) or more when applying a two-component reactive urethane primer for concrete and mortar to an adherend, A two-component reactive solvent-free urethane primer for hand-painting, which comprises a step of applying a liquid urethane primer to an adherend and a step of coating and laminating a urea coating material after the coated liquid urethane primer is cured. This is a coating method.

In the step of preparing the liquid urethane primer, the isocyanate component of the main component is a diphenylmethane diisocyanate compound mixture represented by general formulas (1) and (2) (hereinafter referred to as MDI isomer mixture) and a general formula (3 ) And a carbodiimide-modified MDI (hereinafter referred to as liquid MDI), and its mass mixing ratio (MDI isomer mixture / liquid MDI) is 0/100 to 98/2. It is a coating method of a two-component reactive solventless urethane primer for coating.

（１）

(1)

（２）

(2)

（３）

(3)

According to the present invention, in the step of preparing the liquid urethane primer, the MDI isomer mixture includes a 4,4′-isomer represented by the general formula (1) and a 2,4′-isomer represented by the general formula (2). A mixture containing a body, and its mass mixing ratio (4,4′-isomer / 2,4′-isomer) is in the range of 30/70 to 65/35. It is a coating method of a two-component reaction type solventless urethane primer.

In the step of preparing the liquid urethane primer according to the present invention, the polyol component of the curing agent is polyoxypropylene triol and castor oil, and the mass ratio of the polyoxypropylene triol is 15% to 50%. This is a coating method of a two-component reactive solventless urethane primer for hand coating.

The present invention is characterized in that, in the step of adjusting the liquid urethane primer, the equivalent ratio (NCO group / OH group) of the isocyanate component of the main agent and the polyol component of the curing agent is in the range of 0.7 to 4.0. It is a coating method of a two-component reactive solventless urethane primer for hand coating.

Furthermore, in the step of preparing the liquid urethane primer, the present invention is a method in which Portland cement powder is added to 1/1/0 (main agent / hardener / cement) to 1/0 in the main agent and the hardener having a mass ratio of 1/1. It is a coating method of a two-component reactive solventless urethane primer for hand-painting, which is blended at a mixing ratio (mass) of 1/2 (main agent / curing agent / cement).

In addition, the present invention is characterized in that, after 24 hours to 144 hours have elapsed (within 6 days) after the liquid urethane primer is applied to the adherend, a polyurea coating material is overcoated and laminated. It is a coating method of a two-component reaction type solventless urethane primer for hand coating.

Further, the present invention is a coating method of a two-component reactive solventless urethane primer for hand coating, wherein the adherend is concrete or mortar.

The coating method of the two-component reactive solvent-free urethane primer for hand coating of the present invention is environmentally friendly, and the resulting primer coating film is compared with conventional water-based epoxy resins and water-based acrylic resin primers. It has excellent adhesion and water resistance for adherends such as concrete and mortar. Also, the polyurea coating material can be overcoated within a period of 6 days after coating, and exhibits adhesion performance equal to or better than that of the solvent-based primer to the adherend and the topcoat material. Further, since it is solvent-free, it is extremely safe for workers and the environment, and is particularly suitable for the waterproof field of hermetic structures.

As a coating method of the two-component reactive solvent-free urethane primer for hand-coating of the present invention, it can be used in combination with an automatic mixing device such as a static mixer or a dynamic mixer because the leveling after coating is relatively long. Then, after mixing, it is hand-coated by a hand tool for coating such as a roller, a brush, and a trowel.

Specific examples include non-solvents such as concrete or mortar in the interior of closed systems or in pits, which are subject to coating. In places where there are many places such as corners and wall joints, hand coating using a roller or a brush is suitable.

In this way, in consideration of the situation at the coating site, etc., it is possible to select coating by spraying or manual coating by roller or brush using the automatic mixing device in combination. In addition, as for the thickness after drying of the solventless urethane primer used by this invention, 10-250 micrometers is preferable.

The coating method of the two-component reactive solvent-free urethane primer for hand-coating of the present invention comprises a step of adjusting a liquid urethane primer having a usable time of 40 minutes (500 mPa · s reached) or more, and the liquid urethane It has the process of applying a primer to a to-be-adhered body, and the process of apply | coating and laminating | stacking a polyurea coating material after the coated liquid urethane primer hardens | cures.

As a coating method for the two-component reactive solvent-free urethane primer for hand-coating of the present invention, the step of preparing a liquid urethane primer having a usable time of 40 minutes (reaching 500 mPa · s) or more is the main component isocyanate. The compound can be used by mixing the MDI isomer mixture and the liquid MDI within a predetermined range.

The main component isocyanate compound used in the coating method of the two-component reactive solvent-free urethane primer for hand coating of the present invention is a diphenylmethane diisocyanate compound mixture represented by general formulas (1) and (2) (hereinafter referred to as MDI isomers). And a carbodiimide-modified MDI represented by the general formula (3) (hereinafter referred to as liquid MDI), and its mass mixing ratio (MDI isomer mixture / liquid MDI) ranges from 0/100 to 98 / 2.

（１）

(1)

（２）

(2)

（３）

(3)

As a method for producing an MDI isomer mixture, first, polymeric methylenediamine (hereinafter referred to as polymeric MDA) is produced by a condensation reaction of aniline and formalin. Monomeric MDI (hereinafter referred to as MDI) can be separated from the obtained polymeric MDA by phosgenation and distillation or crystallization from the obtained polymeric MDI mixture (for example, trade name “Millionate MR200”).

Depending on the substitution position of the NCO group, the resulting MDI is known to exist in three types: 2,2'-isomer, 2,4'-isomer, and 4,4'-isomer. 4,4′-MDI (CAS registration number: 101-68-8, melting point: 40 ° C.) is a white or pale yellow solid at room temperature. When handling, it is heated and completely melted, and then impurities are removed by filtration or the like. It is preferably used as a reaction raw material.

The above MDI isomer mixture contains the 4,4′-isomer represented by the general formula (1) and the 2,4′-isomer represented by the general formula (2), and the mixing ratio is 4,4′-isomer / 2,4′-isomer and 30/70 to 65/35 (mass ratio). In the present invention, the range of the isomer mixing ratio in the primer curing agent is preferably 30/70 to 55/45 (mass ratio) in view of storage stability of the main agent, pot life, physical property value (elongation rate) and the like. The MDI isomer mixture has a melting point of about 20 ° C. and crystallizes in winter.

On the other hand, the liquid MDI is a polyisocyanate represented by the general formula (3) and having an isocyanurate structure obtained by cyclization of isocyanate groups of MDI and trimerizing them (for example, trade name “Millionate MTL”). Also, the white turbidity due to precipitation of unmodified isocyanate is small.

In the MDI urethane primer, the difference in pot life (minutes) depending on the type of isocyanate is clear. According to <Evaluation method of pot life> (1) described later, the time until the viscosity at which the uncured liquid can be applied reaches 500 mPa · s / 23 ° C. tends to increase in the order of MR200 <MTL <MI. is there.

Specifically, mixing with the MDI isomer mixture / liquid MDI in the main agent increases the pot life as the content of the MDI isomer mixture increases, but it may crystallize in winter. Further, if the content of liquid MDI is increased, the possibility of crystallization of the main agent is reduced, but the pot life is shortened.

From the low temperature stability of the main agent, pot life, and various physical properties (adhesiveness, hardness, etc.), the mixing ratio of the MDI isomer mixture / liquid MDI is preferably 0/100 to 98/2 (mass ratio). More preferably, it is 70 / 30-95 / 5 (mass ratio).

In the liquid urethane primer preparation step of the present invention, the polyoxyalkylene polyol as a raw material is preferably a polyoxypropylene polyol or a polyoxyethylenepropylene polyol. These are low molecular polyols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexane glycol, glycerin, trimethylolpropane, propylene oxide or propylene oxide and ethylene oxide. Can be obtained by addition polymerization.

The polyol component of the urethane primer used in the present invention is the above polyoxyalkylene polyol alone or a mixed polyol of the polyoxyalkylene polyol and castor oil which is an oxyacid oil polyol. The castor oil of the present invention can be used without any particular problem as long as it is a grade used as a normal urethane raw material.

The polyoxyalkylene polyol has an average of 2 to 3 hydroxyl groups in the molecule, and the range of the hydroxyl value is preferably 100 to 500 mgKOH / g. Even in the combined use of polyoxyalkylene polyol and castor oil, a mixed polyol having an average hydroxyl value of 100 to 400 mgKOH / g is preferred. Application of a solvent-free urethane primer for hand coating, in which the equivalent ratio (NCO group / OH group) of the isocyanate component in the main agent and the polyol component in the curing agent is in the range of 0.7 to 4.0. It is a construction method.

In the two-component reaction type urethane primer of the present invention, the equivalent ratio (NCO group / OH group) of the isocyanate group contained in the main agent and the hydroxyl group contained in the curing agent is preferably 0.7 to 4.0, more preferably. It is 0.7-2.6. When the equivalent ratio (NCO group / OH group) is within the above range, it is easy to ensure the desired pot life and physical properties of the cured product. In addition, when the equivalent ratio (NCO group / OH group) is within the above range, the interlaminar adhesion between the primer layer and the polyurea coating material layer, which is the overcoat material, is also excellent.

In the solvent-free two-component reaction type urethane primer of the present invention, auxiliary agents such as a plasticizer, a color pigment and an anti-settling agent can be added to the curing agent as desired. In addition to the main agent and the curing agent, cement powder may be blended as needed (hereinafter referred to as “cement blending primer”).

The blending ratio (mass ratio) of the cement blended primer is preferably 1/0 to 1/2 for the primer / cement, and particularly preferably 1/1/0 to 1/1/2 for the main agent / curing agent / cement. The thickness of the primer layer may be appropriately set in consideration of the adhesiveness with the urethane coating layer and the state of the base, but usually about 0.05 to 0.2 mm is preferable. The coating amount is preferably 0.1 to 0.5 kg / m ² . The primer layer composed of the cement-mixed primer can reduce ground treatment such as small joints and cracks. Moreover, foaming by moisture etc. can be suppressed by mix | blending cement. Examples of cement that can be used in the present invention include Portland cement, early-strength cement, fly ash cement, and alumina cement.

Although the two-component reaction type urethane primer of the present invention is solvent-free, the viscosity immediately after mixing with the main agent and the curing agent (mixed initial viscosity) is 250 mPa · s / 23 ° C. or less, and the adherend adheres to concrete or mortar. The permeability is good. When the viscosity exceeds 1000 mPa · s / 23 ° C., workability at the time of construction is lowered, and the permeability to the adherend is not preferable.

The polyurea coating material, which is the above-mentioned topcoat material used in the present invention, is a polyurea / polyurethane anticorrosion material, a polyurea / polyurethane coating waterproofing material, a polyurea / polyurethane coating floor material, or a polyurea / polyurethane anticorrosion material. is there. HC spray AU (product name, manufactured by Hodogaya Bandex Building Materials Co., Ltd.) is a polyurea / polyurethane anticorrosive material having such characteristics. In addition, HC eco-proof (product name, manufactured by Hodogaya Bandex Building Materials Co., Ltd.) as a polyurea / polyurethane coating waterproofing material, HC spray F (product name, manufactured by Hodogaya Bandex Building Materials Co., Ltd.), etc. as a polyurea coating film flooring Can be mentioned.

The polyurea coating material includes a main component mainly composed of an isocyanate group-terminated prepolymer as an overcoat material and an aromatic polyamine cross-linking agent after the primer layer is applied on the adherend concrete or the like at a construction site. A curing structure is weighed and mixed with an electric stirrer or an automatic mixing device, and a laminated structure composed of a polyurea coating layer that is cured at room temperature is formed by mechanical coating such as hand coating or spraying.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to the following Example at all. In Examples and Comparative Examples, “part”, “ratio” or “combination ratio” is based on mass.

The components contained in the main agent and the curing agent used in Examples and Comparative Examples are shown below. Moreover, it shows below also about the evaluation method used by the Example and the comparative example.

<Main agent>
-MDI isomer mixture (4,4'-MDI / 2,4'-MDI mixture):
(Brand name "Lupranate MI", manufactured by BASF INOAC polyurethane)
-MDI isomer mixture (4,4'-MDI / 2,4'-MDI mixture):
(Product name "Millionate NM", manufactured by Tosoh Corporation)
-Carbodiimide-modified MDI:
(Product name "Millionate MTL", manufactured by Nippon Polyurethane Industry Co., Ltd.)

<Curing agent>
Castor oil: molecular weight 950
(Brand name "Castor oil round special A", manufactured by Ito Oil Co., Ltd.)
T-400: polyoxypropylene triol, molecular weight 400
(Brand name "ACT COL T-400", manufactured by Mitsui Chemicals, Inc.)
・ Dioctyl phthalate:
(Product name "Dioctyl phthalate", manufactured by Daihachi Chemical Industry)

<Cement powder>
・ Portland cement powder:
(Product name “Portland Cement”, Taiheiyo Cement Co., Ltd.)

<Measurement method of viscosity>
The viscosity is 23 ° C. using a rotational viscometer (Toki Sangyo Co., Ltd., B8M type) according to “Testing method for tolylene diisocyanate type prepolymer for thermosetting urethane elastomer 6.2 viscosity” of JIS K 7301: 1995. Measured with

<Initial mixing viscosity>
The initial mixing viscosity is a viscosity at 23 ° C. in a mixed system immediately after a predetermined amount of a curing agent is added to a liquid main ingredient and stirred. It can be measured by the above rotational viscometer.

<Evaluation method of pot life>
(1) Urethane primer:
After mixing the main agent and curing agent, the time (minutes) until the viscosity at 23 ° C. of the mixed solution reached 500 centipoise (mPa · s) was defined as the time during which coating can be performed without any trouble (potential time).
(2) Urethane coating material:
After mixing the main agent and the curing agent, the time (minutes) until the viscosity at 23 ° C. of the mixed solution reached 100,000 centipoise was defined as the coating time (usable time).

<Method for evaluating curability (finger touch method)>
The main agent and the curing agent were mixed and then applied onto a slate plate, and the curability was evaluated by touching the cured state of the coating film after 16 hours by hand. Those with particularly good curability are marked with ◎, those with good curability are marked with ○, those with slightly bad are marked with Δ, and those with poor curability are marked with ×.

<Adhesion test method (kenken type test)>
Adhesion test piece: base (concrete board), top coat (HC spray AU)
Adhesion tester: Digital Gauge GC74 / Oxjack Co., Ltd. Adhesion test method: The top coat is applied three days after the primer application. One week later, evaluation will be made by Kenken-style test. An area ratio (%) of material destruction is evaluated as a destruction state by an average value of three times. Judgment evaluation is performed according to the criteria described in the following table (1-1) using the three times measured strength value and the area ratio (%) of material destruction. Note that n is the number of measurements.

<Adhesion test method (180 ° peel)>
Adhesion test piece: Base (concrete board), topcoat (HC Eco-proof EN)
Adhesion tester: Autograph / Shimadzu Corporation Adhesion test method: The top coat material is applied together with the nonwoven fabric the next day after primer application. One week later, the nonwoven fabric is pulled and evaluated in the 180 ° direction by an autograph test. The area ratio (%) of material destruction is evaluated as the destruction state by an average value. Judgment evaluation is performed according to the criteria described in the following table (1-2) using the area ratio (%) of material destruction.

The trade names and raw material names described in the following examples and comparative examples are abbreviated as follows.
Lupranate MI: MI (MDI isomer mixture)
Millionate NM: NM (MDI isomer mixture)
Millionate MTL: MTL (liquid MDI)
Act call T-400: T-400
Castor oil malt A: castor oil dioctyl phthalate: plasticizer

[Example 1, Comparative Example 1]
(1) A main agent and a curing agent having the composition shown in Table (2-1) were prepared according to the following procedure.
(2) As the isocyanate composition (main agent), MI and MTL are studied, and considering the crystallization and low viscosity (23 ° C.) of MI in winter, the mixing ratio of the MDI isomer mixture (MI) is Sample solutions having 50/50 and varying MI / MTL mixing ratio were prepared.
(3) According to the above <Method for measuring viscosity>, the properties (5 ° C.) of each sample were determined by measuring the sample solution viscosity (mPa · s / 23 ° C.) of each main agent and by visual observation.
(4) The polyol composition (curing agent) was a polyoxyalkylene polyol T-400, castor oil, and a plasticizer were mixed in predetermined amounts to obtain a polyol composition.
(5) The isocyanate composition and the polyol composition are allowed to stand at 23 ° C. for 24 hours or longer, and then mixed at 23 ° C. so that the ratio of the main agent and the curing agent is 1/1. The pot life (according to the above <Method for evaluating pot life>) was measured.
(6) Under the above measurement conditions, Portland cement powder is mixed with the main agent and the curing agent so that the mixing ratio is 1/1/1, and applied at an application amount of 0.3 kg / m ² , and the curability thereof. A test was conducted. Further, in accordance with the above-described adhesion test method, an adhesion test between the base material (concrete plate) and the primer, and the primer and the overcoat material (HC spray AU) was performed.
(7) For Comparative Example 1-1 shown in Table (2-1), the test was performed in the same manner as in the above (1) to (6). The results are shown in Table (2-1).
(8) A main agent and a curing agent having the composition shown in Table (2-2) were prepared according to the following procedure.
(9) As the isocyanate composition (main agent), NM and MTL are studied, and considering the crystallization and low viscosity (23 ° C.) of NM in winter, the mixing ratio of the MDI isomer mixture (NM) is Sample solutions with 45/55 and varying NM / MTL mixing ratios were prepared.
(10) According to the above <Measurement Method of Viscosity>, the sample solution viscosity (mPa · s / 23 ° C.) of each main agent was measured, and the property (5 ° C.) of each sample was determined by visual inspection.
(11) The polyol composition (curing agent) was a polyoxyalkylene polyol T-400, castor oil, and a plasticizer were mixed in predetermined amounts to obtain a polyol composition.
(12) The isocyanate composition and the polyol composition are allowed to stand at 23 ° C. for 24 hours or longer, and then mixed at 23 ° C. so that the ratio of the main agent and the curing agent is 1/1. The pot life (according to the above <Method for evaluating pot life>) was measured.
(13) Under the above measurement conditions, Portland cement powder was mixed with the main agent and the curing agent so that the mixing ratio was 2/1/2, and the mixture was applied at a coating amount of 0.3 kg / m ² . Further, in accordance with the above-described adhesion test method, an adhesion test between a base material (concrete board) and a primer, and a primer and a top coating material (HC Ecoproof EN) was performed.
(14) For Comparative Example 1-2 shown in Table (2-2), a test was performed in the same manner as in the above (8) to (13). The results are shown in Table (2-2).

[Example 2]
(1) Under the conditions shown in Table 3, a main agent and a curing agent were prepared in which the mixing ratio with 4,4′-MDI / 2,4′-MDI was changed.
(2) Using the obtained main agent and curing agent, the mixed primer initial viscosity (mPa · s / 23 ° C.), pot life (minutes), and primer coating film physical properties were measured in the same manner as in Example 1 above. did.
(3) Further, an adhesion test between the base material (concrete plate) and the primer, and the primer and the top coat material (HC spray AU) was performed.
(4) The results are listed in Table 3.

[Example 3, Comparative Example 3]
(1) A base agent and a curing agent were prepared in the same manner as in Example 1 under the conditions shown in Table 4.
(2) Using the obtained main agent and curing agent, the viscosity (mPa · s / 23 ° C.), the initial mixing viscosity of the primer (mPa · s / 23 ° C.), and the pot life (minutes) as in Example 1. ) Was measured.
(3) In the same manner as in Example 1, Portland cement powder was mixed with the main agent and the curing agent so as to have a mixing ratio of 1/1/1, and applied at a coating amount of 0.3 kg / m ² and cured. The test was conducted for sex. Further, an adhesion test between the base material (concrete plate) and the primer, and the primer and the top coating material (HC spray AU) was performed.
(4) For Comparative Examples 3-1 to 3-3 shown in Table 4, tests were performed in the same manner as in the above (1) to (3). The results are listed in Table 4.

In Example 3-5 and Comparative Example 3-3 (curing agent composition) in Table 4, when the proportion of T-400 in the polyol is 50 parts or more, rapid gelation is observed after mixing with the main agent.

[Example 4, Comparative Example 4]
(1) Under the conditions shown in Table 5, the main agent and the curing agent were prepared in the same manner as in Example 1, and the following experiment was performed.
(2) Using the obtained main agent and curing agent, the equivalent ratio of the main agent / curing agent was changed within the range of 0.7 to 5.0, and the initial mixing viscosity of the obtained primer and the pot life Was measured.
(3) Further, Portland cement powder was mixed with the main agent and the curing agent so as to have a mixing ratio shown in Table 5, and a test (a finger touch method) was performed on the curability. Further, in the same manner as in Example 1 above, an adhesion test between a base material (concrete plate) and a primer, and a primer and an overcoat material (HC spray AU) was performed.
(4) For Comparative Examples 4-1 to 4-2 shown in Table 5, tests were performed in the same manner as in the above (1) to (3). The results are listed in Table 5.

[Example 5, Comparative Example 5]
(1) Under the conditions shown in Table 6, the main agent and the curing agent were prepared in the same manner as in Example 1, and the following experiment was performed.
(2) Using the obtained main agent and curing agent, the mixing ratio of the main agent / curing agent was fixed to 1/1, and the mixed initial viscosity and working life of the obtained primer were measured.
(3) Further, Portland cement powder was mixed with the main agent and the curing agent so that the mixing ratio was 1/1 / (0 to 3), and the curability was tested (finger touch method). Further, in the same manner as in Example 1 above, an adhesion test between a base material (concrete plate) and a primer, and a primer and an overcoat material (HC spray AU) was performed.
(4) For Comparative Examples 5-1 to 5-2 shown in Table 6, tests were performed in the same manner as in the above (1) to (3). The results are listed in Table 6.

[Example 6]
(1) Under the conditions shown in Table 7, a main agent and a curing agent were prepared in the same manner as in Example 1, and a comparative test with other company's products (water-based primer, one-part moisture type urethane primer, patented product) was performed. The results are listed in Table 7.

From the results of Table 7, the coating material obtained by the coating method of the two-component reactive solventless urethane primer for hand coating of the present invention is odorless, good curability, compared to the existing urethane primer, And a coating material having excellent adhesiveness.

Using the two-component reactive solvent-free urethane primer coating method of the present invention, a solvent-free urethane primer having high safety and excellent quality performance is stably provided to customers. For this reason, the concrete or mortar of the base in a closed system or in the pit is to be coated, and the irregular shape that is difficult to apply by spray, the narrow area of the coating area, the protruding corner, the entering corner, and the wall surface jointing In places where there are many places such as parts, hand coating using a roller or a brush is suitable.

Claims (8)

A method for coating a two-component reactive solvent-free urethane primer for hand-coating, wherein the liquid urethane primer has a usable time of 40 minutes (reaching 500 mPa · s) or more, and the liquid urethane primer It is characterized by having a step of coating the adherend on the adherend and a step of coating and laminating the urethane coating material after the coated liquid urethane primer is cured. In the step of preparing the liquid urethane primer, the main component isocyanate component is represented by the general formula (1) or diphenylmethane diisocyanate compound mixture (hereinafter referred to as MDI isomer mixture) and the general formula (3). 2. The mixture according to claim 1, wherein the mixture is a carbodiimide-modified MDI (hereinafter referred to as liquid MDI), and the mass mixing ratio (MDI isomer mixture / liquid MDI) is 0/100 to 98/2. Coating method of two-component reactive solvent-free urethane primer for hand coating.

(1)

(2)

(3) In the step of preparing the liquid urethane primer, the MDI isomer mixture includes a 4,4′-isomer represented by the general formula (1) and a 2,4′-isomer represented by the general formula (2). The mass mixing ratio (4,4′-isomer / 2,4′-isomer) is in the range of 30/70 to 65/35, according to claim 2. A two-component reactive solvent-free urethane primer coating method. In the step of preparing the liquid urethane primer, the polyol component of the curing agent is polyoxypropylene triol and castor oil, and the mass ratio of the polyoxypropylene triol is 15% to 50%. The coating method of the two-component reaction type solvent-free urethane primer for hand-coating as described in any one of 3. 2. In the step of adjusting the liquid urethane primer, the equivalent ratio (NCO group / OH group) of the isocyanate component of the main agent and the polyol component of the curing agent is in the range of 0.7 to 4.0. The coating method of the two-component reaction type solventless urethane primer for hand-painting as described in any one of 1-4. In the step of preparing the liquid urethane primer, the Portland cement powder is 1/1/0 (main agent / hardener / cement) to 1/1/2 (main agent) in the main agent and the hardener having a mass ratio of 1/1. The coating of the two-component reactive solventless urethane primer for hand-painting according to any one of claims 1 to 5, characterized in that it is blended at a mixing ratio (mass) of (/ hardener / cement). Construction method. 7. The process of overcoating and laminating a urethane coating material after 24 hours to 144 hours have elapsed since the liquid urethane primer was applied to an adherend. The coating method of the two-component reactive solvent-free urethane primer for hand-painting as described in 2. The coating method of the two-component reactive solventless urethane primer for hand-painting according to any one of claims 1 to 7, wherein the adherend is concrete or mortar.