JP5515274B2 - Curing agent for two-component polyurethane resin paint, method for producing the same, and two-component polyurethane resin paint - Google Patents

Description

  The present invention relates to a two-component polyurethane resin paint using polyisocyanate as a curing agent.

  The two-component polyurethane resin paint using various resin components such as polyol as the main agent (resin) and polyisocyanate as the curing agent can be dried at room temperature, has a good coating appearance, excellent coating strength, Since a coating film having good acid resistance can be formed, it is used in the fields of construction, earthwork and vehicles.

When coating with a two-component polyurethane resin paint, a catalyst is added to the above-described two components in order to promote curability and drying. At this time, a catalyst is also added in advance to one of the two liquids.
As such a catalyst, for example, dibutyltin dilaurate, which is an organic metal compound, or tertiary amine such as triethyleneamine, which is an organic nonmetallic compound, is used.

  However, when these catalysts are used in a large amount for improving curability, there is a problem that the appearance of the coating film is deteriorated. In particular, a highly active organometallic compound is likely to cause this problem because the curing reaction easily proceeds non-uniformly.

In order to improve the above problems, various techniques have been proposed.
For example, a urethane resin composition comprising a polyisocyanate compound obtained from an aliphatic or alicyclic diisocyanate and a polyhydroxyl compound having two or more hydroxyl groups, (A) a monoalkyltin tris fatty acid salt and (B) a dialkyl as a curing catalyst A urethane resin composition using a tin difatty acid salt has been proposed. This urethane resin composition has a fast curability and a long pot life (the usable time from mixing to the start of curing. It is also called pot life. ). Here, as a polyisocyanate compound obtained from an aliphatic or alicyclic diisocyanate, a diisocyanate such as 1,6-hexamethylene diisocyanate (HDI), 3,5,5-trimethyl-3-isocyanatomethylcyclohexane (IPDI) or the like is used. A polyisocyanate having an isocyanate group-containing biuret, isocyanurate, urethane, or allophanate group is used (see Patent Document 1).

For example, although it is related to a urethane elastomer-forming composition, it is obtained by reacting component (A): diphenylmethane diisocyanate (A1) with a bifunctional polyol (A2) having a number average molecular weight of 500 to 3,000. A main agent containing an isocyanate group-terminated urethane prepolymer, a component (B): a short chain diol (B1) having a number average molecular weight of 300 or less, and a curing agent containing a short chain triol (B2) having a number average molecular weight of 500 or less; C) Component: A catalyst containing a catalyst containing N, N, N'-trimethylaminoethylethanolamine (C1) has been proposed, the curing time (demolding time) is short, and the pot life (casting is possible) It is said that a novel urethane elastomer-forming composition having a long time) is provided. In addition, only when N, N, N′-trimethylaminoethylethanolamine was used as the only reaction catalyst for urethane foam, a remarkable rapid demolding effect was produced in the formation of non-foamed cast urethane elastomer. (Refer to Patent Document 2).
Further, Patent Documents 3 and 4 are prior arts disclosed by the applicant of the present application.
JP 2001-106758 A JP 2004-224938 A Japanese Patent Laid-Open No. 10-273517 Japanese Patent Laid-Open No. 11-228653

  However, the above-mentioned two conventional techniques are not different from other conventional techniques in that a catalyst is added to these two liquids blended when coating with a two-component polyurethane resin paint. For this reason, apart from the presence or absence of a significant decrease in the appearance of the paint film, it is confirmed by a phenomenon that a part of the paint film is peeled off during the solvent resistance test (MEK rubbing test), which is one of the evaluation indices of the paint film appearance. Thus, it is considered that there is a limit to the improvement of the problem that the solvent resistance deteriorates.

The present invention has been made in view of the above problems, and a curing agent for a two-component polyurethane resin paint, a method for producing the same, and a two-component polyurethane that can effectively improve the problem of deterioration in solvent resistance. An object is to provide a resin paint.
The present invention also provides a curing agent for a two-component polyurethane resin paint, a method for producing the same, and a two-component polyurethane resin paint, which are excellent in balance between solvent resistance, pot life, quick drying property, fast curing property, and the like. With the goal.

2-component polyurethane resin coating hardeners according to the present invention, a polyisocyanate, characterized in that it contains as the main component a tertiary polyisocyanate modified product obtained by modified with amine having a hydroxyl group.

  The curing agent for a two-component polyurethane resin paint according to the present invention is preferably characterized in that the polyisocyanate contains one or both of an isocyanurate group and an allophanate group.

  Moreover, the curing agent for a two-component polyurethane resin paint according to the present invention preferably includes a polyisocyanate in which the polyisocyanate is derived from one or both of an aliphatic polyisocyanate and an alicyclic polyisocyanate. It is characterized by that.

  The curing agent for a two-component polyurethane resin paint according to the present invention is preferably characterized in that the main agent is an acrylic resin.

  A two-component polyurethane resin paint according to the present invention is characterized by comprising the curing agent for the two-component polyurethane resin paint and a main agent having active hydrogen.

  In the method for producing a curing agent for a two-component polyurethane resin paint according to the present invention, the polyisocyanate is modified with a modifying agent having a functional group that exhibits a catalytic action in a reaction with a main agent having a hydroxyl group and active hydrogen. It is characterized by.

  The method for producing a curing agent for a two-component polyurethane resin paint according to the present invention is characterized in that the polyisocyanate contains one or both of an isocyanurate group and an allophanate group.

  In the method for producing a curing agent for a two-component polyurethane resin paint according to the present invention, preferably, the polyisocyanate is derived from one or both of an aliphatic polyisocyanate and an alicyclic polyisocyanate. Isocyanate is included.

  In the method for producing a curing agent for a two-component polyurethane resin paint according to the present invention, preferably, the main agent is an acrylic resin.

2-component polyurethane resin coating hardeners according to the present invention, a polyisocyanate, for mainly containing tertiary polyisocyanate modified product obtained by modified with amines having hydroxyl group, deterioration of solvent resistance The problem can be effectively improved.
Moreover, the curing agent for a two-component polyurethane resin paint according to the present invention can provide a two-component polyurethane resin paint excellent in the balance between solvent resistance, pot life, quick drying property, fast curing property, and the like.
The method for producing a curing agent for a two-component polyurethane resin paint according to the present invention can suitably obtain the curing agent for a two-component polyurethane resin coating according to the present invention, and the two-component type according to the present invention. The polyurethane resin paint can suitably obtain the effect of the curing agent for a two-component polyurethane resin paint according to the present invention.

  An embodiment (this embodiment) of the present invention will be described below.

The curing agent for a two-component polyurethane resin paint according to the present embodiment is a polyisocyanate obtained by modifying a polyisocyanate with a modifier having a functional group that exhibits a catalytic action in a reaction with a main component having a hydroxyl group and active hydrogen. It contains a modified product as a main component.
Moreover, the manufacturing method of the hardening | curing agent for 2 liquid type polyurethane resin coating materials which concerns on this Embodiment which can manufacture suitably the hardening | curing agent for 2 liquid type polyurethane resin coating materials which concern on the said this embodiment is polyisocyanate, It is modified with a modifying agent having a functional group that exhibits a catalytic action in a reaction with a main agent having a hydroxyl group and active hydrogen.

The polyisocyanate is not particularly limited, and examples thereof include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (TDI), 2,2′-diphenylmethane diisocyanate, and 2,4′-diphenylmethane diester. An aromatic polyisocyanate such as isocyanate and 4,4′-diphenylmethane diisocyanate (MDI) may be used, but from the viewpoint of reducing yellowing, it should be an aliphatic polyisocyanate or an alicyclic polyisocyanate. Is more preferable. Either an aliphatic polyisocyanate or an alicyclic polyisocyanate may be used, or both may be used.
As the aliphatic polyisocyanate, for example, hexamethylene diisocyanate (HDI), tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, 2,2,4-trimethyl-hexamethylene-1,6-diisocyanate may be used. it can.
Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis (isocyanatemethyl) -cyclohexane, 1,4-bis (isocyanatemethyl) -cyclohexane, 4,4 ′.
-Dicyclohexylmethane diisocyanate, 2,5-diisocyanatomethylbicyclo [2,2,1] heptane, 2,6-diisocyanatomethylbicyclo [2,2,1] heptane, and the like can be used.

It is more preferable that the polyisocyanate contains one or both of an isocyanurate group and an allophanate group from the viewpoints of coating film strength, drying property and curability.
The isocyanurate group is obtained by reacting polyisocyanate or polyisocyanate urethane-treated with monool and / or diol using an isocyanurate-forming catalyst.
Allophanate groups are obtained by reacting polyisocyanates with monools and / or diols in the presence of an allophanatization catalyst.
The monool is not particularly limited, for example, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, ethyldimethyl-1-hexanol, methyl-1-nonanol, dimethyl-1-octanol, tetramethyl-1-hexanol, 3-ethyl-4,5,6-trimethyloctanol, 4, 5,6,7-tetramethylnonanol, 4,5,8-trimethyldecanol, 4,7,8-trimethyldecanol, tridecanol, tetradecanol, 2-hexyldodecanol, 2-octyldodecanol, 2 -Dodecyldecanol, 2-hexadecyl octadecano Monools such as 1 to 20 carbon atoms and the like. These may be used alone or in combination of two or more.
The diol is not particularly limited, and examples thereof include ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butane. Diol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1 , 9-nonanediol, 3,3-dimethylolheptane, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-ethyl-1,3-propanediol, 2-normalpropyl-1,3 -Propanediol, 2-isopropyl-1,3-propanediol, 2-no Malbutyl-1,3-propanediol, 2-isobutyl-1,3-propanediol, 2-tertiarybutyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2, 2-diethyl-1,3-propanediol, 2-ethyl-2-normalpropyl-1,3-propanediol, 2-ethyl-2-normalbutyl-1,3-propanediol, 2-ethyl-3-ethyl -1,4-butanediol, 2-methyl-3-ethyl-1,4-butanediol, 2,3-diethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol It is done. These may be used alone or in combination of two or more.
Among these monools and diols, a monool having 3 to 40 carbon atoms is preferable in view of further increasing the solubility of the resulting polyisocyanate composition in a low-polar organic solvent. Furthermore, in consideration of avoiding a decrease in the NCO content of the resulting polyisocyanate composition, a monool having 3 to 20 carbon atoms is more preferable.
The polyisocyanate containing an isocyanurate group may be modified with isocyanurate using only the organic polyisocyanate described above, but isocyanurate-modified after urethane modification with the exemplified monool and diol. More preferable from the viewpoint of compatibility.
The polyisocyanate may contain a functional group derived from an isocyanate group such as a urethane group, a urea group, a biuret group, a uretidione group, a carbodiimide group, a uretonimine group, an amide group, an acylurea group, or a carbamoyl chloride group. .
Moreover, polyisocyanate may use organic polyisocyanate together with what modified organic polyisocyanate with the compound which has catalytic activity.

As described above, the modifying agent that modifies the polyisocyanate has a functional group that exhibits a catalytic action in the reaction with the main component (resin) having a hydroxyl group and active hydrogen. Here, functional groups that exhibit a catalytic action in the reaction with the main agent (resin) having active hydrogen are represented by tertiary amines (tertiary amino groups) and quaternary ammoniums (quaternary ammonium groups). And functional groups having basic catalytic ability, and functional groups having acid catalytic ability such as carboxylic acid (carboxy group), phosphoric acid (phosphoric acid group) and sulfonic acid (sulfo group). .
The modifier is not particularly limited as long as it has these hydroxyl groups and functional groups, but an organic nonmetallic compound is more preferable from the viewpoint of solvent resistance and pot life. Here, the term “nonmetal” means that a metal element having a high catalytic activity such as tin is not included in the structure of the compound. The organic nonmetallic compound preferably has a non-ring structure (not containing an unsaturated ring or a saturated ring as a part of the structure), but is not limited to this and may contain a ring structure.

Examples of the acyclic organic nonmetallic compound include those shown in Table 1 below. These acyclic organic nonmetallic compounds can be used alone or in combination of two or more.
For example, in the case of N, N-dimethylaminohexanol, it has an OH group containing active hydrogen at one end of a long aliphatic hydrocarbon chain, and a functional group that exhibits a catalytic action in the reaction with the main agent at the other end. It has a tertiary amino group.

The main agent that is the counterpart with which the curing agent for a two-component polyurethane resin paint of the present embodiment reacts has active hydrogen. Examples of the active hydrogen include functional groups such as a hydroxyl group, a carboxyl group, an amino group, and a thiol group.
The main agent is not particularly limited as long as the curing agent for a two-component polyurethane resin coating can react to form a coating film having the effects of the present invention.
Examples of the main agent include saturated or unsaturated polyester polyol, polycaprolactone polyol, saturated or unsaturated oil-modified or fatty acid-modified alkyd polyol, amino alkyd polyol, polycarbonate polyol, acrylic polyol, polyether polyol, epoxy polyol, fluorine-containing polyol. Furthermore, saturated or unsaturated polyester resin, polycaprolactone resin, saturated or unsaturated oil-modified or fatty acid-modified alkyd resin, amino alkyd resin, polycarbonate resin, acrylic resin, polyether resin, epoxy resin, polyurethane resin, cellulose acetate butyrate Examples thereof include lato resins and fluorine-containing resins. Of these, acrylic polyols and acrylic resins are particularly preferable from the viewpoint of workability such as drying properties and curability, and economical efficiency, and among them, acrylic resins are more preferable.

The curing agent for a two-component polyurethane resin paint according to the present embodiment is mainly composed of a polyisocyanate-modified product obtained by modifying the above-described polyisocyanate with a modifier, and as long as the effects of the present invention are exhibited. The content of the polyisocyanate-modified product in the curing agent is not limited.
As long as the curing agent for a two-component polyurethane resin paint exhibits the effects of the present invention, as a remaining component other than the polyisocyanate-modified product, a polyisocyanate of a type other than that used for the unmodified polyisocyanate or the modified raw material is used. Isocyanate may be included, and organic solvents and other auxiliaries necessary for coating film formation may be included.

  The method for producing a curing agent for a two-component polyurethane resin paint is appropriately set depending on the type of modifier used and is not limited. For example, a curing agent is produced by blending a modifier with polyisocyanate so as to have a concentration of several tens of ppm to several tens of thousands of ppm, preferably 100 ppm to 15,000 ppm, and reacting at a temperature of about 80 ° C. for about 2 hours. can do.

The curing agent for a two-component polyurethane resin paint according to the present embodiment described above can effectively improve the deterioration of solvent resistance due to poor curing compared to the conventional one. This is because a modifier having a functional group that exhibits a catalytic action in the reaction with a main agent having active hydrogen is combined with polyisocyanate, so that movement in the liquid phase occurs when a curing agent and main agent are blended during coating. As a result, the catalytic action is mitigated compared to the conventional one in which the catalyst is added to either the curing agent or the main agent in advance or the catalyst is added when the curing agent and the main agent are added during coating. It is thought that the solvent resistance is improved.
Moreover, the curing agent for a two-component polyurethane resin paint according to the present embodiment is excellent in balance between solvent resistance, pot life, quick drying property, fast curing property, and the like.
Further, the curing agent for a two-component polyurethane resin paint according to the present embodiment is excellent in quick drying and fast curing properties.

  Moreover, the manufacturing method of the curing agent for two-component polyurethane resin paints according to the present embodiment can suitably obtain the curing agent for two-component polyurethane resin coatings according to the present embodiment.

  Next, the two-component polyurethane resin paint according to the present embodiment is composed of a curing agent for the two-component polyurethane resin paint according to the present embodiment and a main agent having active hydrogen. As the main agent, those described above can be used. Thereby, said effect of the hardening | curing agent for 2 liquid type polyurethane resin coating materials concerning this Embodiment can be acquired suitably.

In addition, the curing agent for two-component resin coatings according to the present embodiment described above is used for one-component coatings, or is used in combination with a different type of main component from the main component for polyurethane resin coatings, or other It is not excluded to use in combination with a curing agent.
Although the present embodiment is for paint applications, the present invention can be used for adhesives, pressure-sensitive adhesives, waterproof top coats, and moisture-curing paints regardless of this. .

  The present invention will be further described with reference to examples and comparative examples. In addition, this invention is not limited to the Example demonstrated below. Moreover, in the following description, the unit (ppm,%) of each component amount is based on mass.

(Polyisocyanate synthesis example 1: Isocyanate 1 (isocyanurate group-containing isocyanate))
After charging 936 g of hexamethylene diisocyanate (hereinafter referred to as HDI) 6 g of 1,3-butanediol 6 g into a 1000 ml glass four-necked flask equipped with a thermometer, stirrer and nitrogen gas inlet tube, and then purging with nitrogen While stirring, the temperature was raised to 50 ° C., and 0.1 g of phenol and 0.04 g of a catalyst (a mixture of potassium isobutyrate: dipropylene glycol: THF = 1: 4.5: 4.5) were added. Sampling was performed while reacting at 110 ° C., and when the NCO content reached 41.5%, 0.004 g of N-cyclohexylsulfamic acid and 0.015 g of 2-ethylhexyl acid phosphate were added to stop the reaction. Next, free HDI was removed by thin film distillation under conditions of 130 ° C. and 0.04 kPa.
The isocyanate 1 thus obtained was a pale yellow liquid having an average functional group number of 3.5, an NCO content of 21.2%, and a viscosity of 2500 (mPa · s at 25 ° C.).

(Polyisocyanate synthesis example 2: Isocyanate 2 (isocyanurate group-containing isocyanate))
HDI961g, 1,3-butanediol 3.5g was charged into a 1000ml glass four-necked flask with a lid equipped with a thermometer, stirrer and nitrogen gas inlet tube, purged with nitrogen, then heated to 50 ° C with stirring. Warm, 0.06 g of phenol 0.1 g, catalyst (a mixture of potassium isobutyrate: dipropylene alcohol: THF = 1: 4.5: 4.5) was added. Sampling was performed while reacting at 110 ° C., and when the NCO content reached 35.0%, 0.007 g of N-cyclohexylsulfamic acid and 0.011 g of 2-ethylhexyl acid phosphate were added to stop the reaction. Next, free HDI was removed by thin film distillation under conditions of 130 ° C. and 0.04 kPa.
The isocyanate 2 thus obtained was a pale yellow liquid having an average functional group number of 4.5, an NCO content of 20.0%, and a viscosity of 8000 (mPa · s at 25 ° C.).

(Polyisocyanate Synthesis Example 3: Isocyanate 3 (Allophanate-Containing Isocyanate))
HDI950g, 1,3-butanediol 50g was charged into a 1000ml glass four-necked flask with a lid equipped with a thermometer, stirrer and nitrogen gas inlet tube, purged with nitrogen, then heated to 50 ° C with stirring. Then, 0.05 g of octylsan zirconyl (1st rare element chemical industry) was added. Sampling was performed while reacting at 110 ° C., and when the NCO content reached 40.3%, 0.055 g of 2-ethylhexyl acid phosphate was added to stop the reaction. Next, free HDI was removed by thin film distillation under conditions of 130 ° C. and 0.04 kPa.
The isocyanate 3 thus obtained was a pale yellow liquid having an average functional group number of 4.8, an NCO content of 19.2%, and a viscosity of 2000 (mPa · s at 25 ° C.).

(Polyisocyanate synthesis example 4: isocyanate 4 (isocyanurate group-containing isocyanate))
VESTANAT T-1890 / 100 (IPDI-based isocyanurate-modified polyisocyanate, manufactured by Evonik Degussa Japan Co., Ltd.), with a 1000 ml glass four-necked flask equipped with a thermometer, stirrer and nitrogen gas inlet tube After charging 600 g of NCO content 17.3%) and 400 g of butyl acetate and purging with nitrogen, the mixture was stirred while raising the temperature to 50 ° C. until VESTANAT T-1890 was completely dissolved.
The isocyanate 4 thus obtained was a pale yellow liquid having an average functional group number of 3.6, an NCO content of 10.4%, and a viscosity of 80 (mPa · s at 25 ° C.).

(Polyisocyanate-modified product synthesis example: curing agent)
After replacing the reactor equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe and a thermometer with nitrogen, 990 g of any isocyanate synthesized in polyisocyanate synthesis examples 1 to 3 and 10 g of any modifier described in Table 1 were used. A curing agent (polyisocyanate-modified product) was obtained by reacting for 2 hours while charging (10,000 ppm) and stirring at 80 ° C.
The types of isocyanate and modifier used in each synthesis example are summarized in the following tables. In each synthesis example, the compounding amount of the modifier with respect to the polyisocyanate is not the above (10 g with respect to 990 g) is shown in the table.

(Example of manufacturing two-component polyurethane resin paint)
Polyisocyanate modified body (curing agent) synthesized in the polyisocyanate modified body synthesis example and acrylic resin (“Acridic A-801” manufactured by Dainippon Ink Co., Ltd.) as the main agent are used in an isocyanate group / hydroxyl ratio in a molar ratio of 1 / A steel plate (JIS G3141, manufactured by Partec Co., Ltd., trade names “SPCC-SB”, PF-1077 treatment), which is degreased with methyl ethyl ketone at room temperature, is 100 μm thick using an applicator. A test piece was prepared by coating with a coating film.

(Two-component polyurethane resin paint production comparative example)
Polyisocyanate (non-modified product) prepared by blending (adding) the polyisocyanate (non-modified product) used in the polyisocyanate-modified product synthesis example or the polyisocyanate modified product (non-modified product) with the modifier used in the polyisocyanate-modified product synthesis example. ) And acrylic resin (“Acridic A-801” manufactured by Dainippon Ink Co., Ltd.) as the main agent, and a mixture of isocyanate groups / hydroxyl groups in a molar ratio of 1/1. A coating film was formed by applying a degreased steel plate (JIS G3141, manufactured by Partec Co., Ltd., trade name “SPCC-SB”, PF-1077 treatment) to a thickness of 100 μm using an applicator.

(Evaluation method)
The coating properties of the paints produced in the two-part polyurethane resin paint production examples and the two-part polyurethane resin paint production comparative examples were evaluated in the following manner.
<MEK rubbing test>
○ MEK rubbing test curing time 1
A test piece that had been dried and baked with a dryer at a temperature of 40 ° C. and 50% RH while changing the drying time (curing time) was reciprocated on the coating film with lightly dipped cotton soaked in methyl ethyl ketone (MEK). The minimum curing time in which the number of reciprocations until the occurrence of this was possible 100 times or more was determined.
○ MEK rubbing test curing time 2
A test piece dried and baked with a dryer at a temperature of 80 ° C. and 50% RH for different drying times (curing time) was reciprocated on the coating film with lightly dipped cotton soaked in methyl ethyl ketone (MEK). The minimum curing time in which the number of reciprocations until the occurrence of this was possible 100 times or more was determined.
○ MEK rubbing test curing time 3
A test piece dried and baked with a dryer at a temperature of 90 ° C. and 50% RH with a different drying time (curing time) was reciprocated with cotton wool lightly soaked in methyl ethyl ketone (MEK) on the coating film, and the coating film was scratched or peeled. The minimum curing time in which the number of reciprocations until the occurrence of this was possible 100 times or more was determined.
○ MEK rubbing test curing temperature 1
Test pieces dried and baked for 30 minutes in a temperature gradient oven under 50% RH conditions were reciprocated with cotton wool lightly soaked in methyl ethyl ketone (MEK) on the coating film. The minimum drying temperature (minimum curing temperature) at which the number of reciprocations until the occurrence of was possible was 100 times or more was determined.
○ MEK rubbing test curing temperature 2
A test piece dried and baked for 90 minutes under a temperature gradient oven at 50% RH under different temperature conditions was reciprocated on a coated cotton cloth lightly soaked in methyl ethyl ketone (MEK). The minimum drying temperature (minimum curing temperature) at which the number of reciprocations until the occurrence of was possible was 100 times or more was determined.
<Shiatsu drying test>
○ Shiatsu drying test 1
For a test piece that was dried and baked for 30 minutes under a 50% RH temperature condition in a temperature gradient oven, when the center of the paint surface was strongly sandwiched between the thumb and forefinger, the paint surface would not have dents due to fingerprints. The drying temperature was determined.
○ Shiatsu drying test 2
For a test piece that was dried and baked with a dryer at a temperature of 40 ° C and 50% RH, changing the drying time (curing time), when the center of the paint surface was strongly sandwiched between the thumb and forefinger, the paint surface was marked with fingerprints. The minimum curing time (minimum drying time) was determined.
○ Shiatsu drying test 3
For test pieces that have been dried and baked with a dryer at a temperature of 80 ° C and 50% RH, with the drying time (curing time) changed, when the center of the paint surface is strongly sandwiched between the thumb and forefinger, the paint surface will have a fingerprint mark. The minimum curing time (minimum drying time) was determined.
<Dry touch test>
○ Finger touch drying test 1
For a test piece that was dried and baked for 30 minutes under a 50% RH temperature condition in a temperature gradient oven, the lowest drying temperature at which the sticky feeling disappeared was determined by lightly touching the center of the coated surface with a fingertip.
○ Finger touch drying test 2
For a test piece that was dried and baked with a dryer at a temperature of 40 ° C. and 50% RH and changing the drying time (curing time), touch the center of the coated surface lightly with the fingertip to minimize the stickiness. Drying time).
○ Finger touch drying test 3
For test pieces that have been dried and baked with a dryer at a temperature of 80 ° C. and 50% RH, changing the drying time (curing time), touch the fingertip lightly to the center of the coated surface, and the minimum curing time (no minimum) Drying time).
<Pot life evaluation>
The polyisocyanate modified (curing agent) synthesized in the polyisocyanate modified synthesis example is blended with “Acridick A-801” manufactured by Dainippon Ink Co., Ltd., which is the main agent, so that the polyisocyanate group / hydroxyl group ratio is 1.0. Then, butyl acetate was added and mixed so that the solid content of the blended solution was 45%. This mixed solution was placed in a constant temperature water bath at 25 ° C., and whether or not the compounded solution was gelated within a predetermined time was measured and a change in viscosity was measured.

  The preparation conditions and evaluation results of the coating films formed with the paints produced in the two-part polyurethane resin paint production examples 1 to 25 and the two-part polyurethane resin paint production comparative examples 1 to 8 are summarized in Tables 2 to 7. . Moreover, pot life evaluation was collectively shown to FIGS. 1-5 except the one part Example and the comparative example.

It is a figure which shows pot life evaluations, such as an Example shown in Table 2. FIG. It is a figure which shows pot life evaluations, such as an Example shown in Table 4. FIG. It is a figure which shows pot life evaluations, such as an Example shown in Table 5. FIG. It is a figure which shows pot life evaluations, such as an Example shown in Table 6. FIG. It is a figure which shows pot life evaluations, such as an Example shown in Table 7.

Claims (9)

The polyisocyanate, 2-component polyurethane resin paint curing agent characterized in that it contains a tertiary polyisocyanate modified product denaturation and comprising an amine as a main component having a hydroxyl group.   The curing agent for a two-component polyurethane resin paint according to claim 1, wherein the polyisocyanate contains one or both of an isocyanurate group and an allophanate group. The curing agent for a two-component polyurethane resin paint according to claim 1 , wherein the polyisocyanate includes a polyisocyanate derived from one or both of an aliphatic polyisocyanate and an alicyclic polyisocyanate. The curing agent for a two-component polyurethane resin paint according to claim 1, wherein the main agent is an acrylic resin . A two-component polyurethane resin paint comprising the curing agent for a two-component polyurethane resin paint according to any one of claims 1 to 4 and a main agent having active hydrogen. A method for producing a curing agent for a two-component polyurethane resin paint, wherein polyisocyanate is modified with a tertiary amine having a hydroxyl group . The method for producing a curing agent for a two-component polyurethane resin paint according to claim 6 , wherein the polyisocyanate contains one or both of an isocyanurate group and an allophanate group . The curing agent for a two-component polyurethane resin paint according to claim 6, wherein the polyisocyanate contains a polyisocyanate derived from one or both of an aliphatic polyisocyanate and an alicyclic polyisocyanate . Production method. The method for producing a curing agent for a two-component polyurethane resin paint according to claim 6, wherein the main agent is an acrylic resin .

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