JP4919667B2 - Two-component polyurethane composition - Google Patents

Description

  The present invention contains a low polarity organic solvent having an aniline point of 10 ° C. to 70 ° C. and, if necessary, at least one silicate selected from tetraalkoxysilane, a tetraalkoxysilane condensate, and a tetraalkoxysilane derivative. The present invention relates to a two-pack type polyurethane composition using a curing agent polyisocyanate composition containing a compound and a main component polyol composition, and particularly to a two-pack type polyurethane composition useful for architectural paints, heavy anticorrosive paints, and the like.

  Two-component polyurethane compositions using aliphatic and alicyclic polyisocyanate compositions are widely used in paints, inks, etc., because they exhibit excellent weather resistance, chemical resistance, abrasion resistance, and the like. It has been broken. In particular, the polyisocyanate composition having an isocyanurate structure and a monoalcohol allophanate structure disclosed in Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5 has a low viscosity or low polarity organic property. It has a feature of excellent solubility in solvents, and has been used as a curing agent for high solid paints or low polar organic solvent soluble paints. However, in recent years, paints that are more environmentally friendly have been demanded, and further improvement in performance has been an issue.

In recent years, oil-based pollutants such as automobile exhaust gas and soot have become more likely to cause rain-stain contamination on the paint film, and in particular, in the field of building exterior paint, it is possible to form a paint film that does not easily adhere to rain-stain pollution. There has been a need for paint.
In order to solve such problems, a polyisocyanate composition is generally used by mixing a tetraalkoxysilane, a condensate thereof, or a derivative thereof, which is generally called a silicate compound, with a polyurethane coating film formed. A method of hydrophilizing the surface has been used. Patent Document 6 proposes a two-component polyurethane composition containing tetraalkoxysilane in the two-component polyurethane composition. Patent Document 7 proposes a two-component polyurethane composition containing a main component polyol composition that can be dissolved in a low-polar organic solvent, a curing agent polyisocyanate composition, and a tetraalkoxysilane having a long-chain alkyl group. ing. In these prior literatures, there is no detailed description regarding the structure of the curing agent polyisocyanate composition, and when mixed with a silicate compound and a low polar organic solvent, there are cases where white turbidity or phase separation may occur due to insufficient compatibility. Patent Document 8 proposes a curing agent polyisocyanate composition comprising a polyisocyanate containing a monoalcohol and a tetraalkoxysilane condensate, which hardly causes phase separation or white turbidity, but these compositions also contain a silicate compound. In some cases, the compatibility is insufficient when the amount is large or at low temperatures.

JP-A-2-250872 JP-A-4-306218 JP-A-5-70444 Japanese Patent Laid-Open No. 5-222007 JP 2003-55433 A International Application WO94 / 06870 Pamphlet Japanese Patent Laid-Open No. 10-102000 JP 2004-277710 A

  The present invention combines stain resistance and weather resistance by combining a curing agent polyisocyanate composition that does not cause white turbidity or phase separation even when the content of a low-polar organic solvent or silicate compound is large, and a main component polyol composition. An object is to provide a two-component polyurethane composition having excellent properties, chemical resistance, abrasion resistance, and the like.

式中のＲは、同一、もしくは異なって炭素数１〜１０のアルキル基、またはアリール基である。
２） 硬化剤ポリイソシアネート組成物が、アニリン点１０℃〜７０℃の低極性有機溶剤を含有する上記１）記載の二液型ポリウレタン組成物。
３） 主剤ポリオール組成物が、アニリン点１０℃〜７０℃の低極性有機溶剤を含有する上
記１）〜２）のいずれかに記載の二液型ポリウレタン組成物。
As a result of diligent research, the present inventors have found that a curing agent polyisocyanate composition containing a polyisocyanate compound obtained from a specific monoalcohol and a diisocyanate and containing allophanate groups and isocyanurate groups in a specific ratio, and acrylic It has been found that the above object can be achieved by using a main component polyol composition containing at least one of a polyol, a polyester polyol and a polyether polyol, and the present invention has been completed based on this.
That is, the present invention is as follows.
1) (A) It is obtained from at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate, and monoalcohol having 1 to 20 carbon atoms, and has a molar ratio of allophanate group / isocyanurate group of 90/10 to 10/10. Curing agent containing at least one silicate compound selected from a polyisocyanate compound of 70/30 and a tetraalkoxysilane represented by the following formula (1), a condensate of tetraalkoxysilane, and a derivative of tetraalkoxysilane The main component polyol composition containing at least one of a polyisocyanate composition and (B) acrylic polyol, polyester polyol, and polyether polyol is an essential component, and the isocyanate group of the main agent polyol composition and the curing agent polyisocyanate composition When A two-component polyurethane composition in which an equivalent ratio of hydroxyl groups (NCO / OH ratio) is 0.2 to 5.0, and a mass ratio of the polyisocyanate compound and the silicate compound is 5/95 to 95/5 .

R in the formula is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group.
2) The two-component polyurethane composition according to 1) above, wherein the curing agent polyisocyanate composition contains a low polarity organic solvent having an aniline point of 10 ° C to 70 ° C.
3) The two-component polyurethane composition according to any one of 1) to 2) above, wherein the main component polyol composition contains a low polarity organic solvent having an aniline point of 10 ° C to 70 ° C.

4 ) The two-component polyurethane composition according to any one of 1) to 3 ) above, wherein the monoalcohol has 4 to 9 carbon atoms.
5 ) The two-component polyurethane composition according to any one of 1) to 4 ) above, which is used for architectural coatings or heavy anticorrosion.
6 ) A building to which the two-component polyurethane composition described in 5 ) above is applied.

  The two-component polyurethane composition of the present invention is obtained by combining a curing agent polyisocyanate composition that does not cause white turbidity or phase separation even when the content of a low-polar organic solvent or a silicate compound is large, and a main component polyol composition. It has the effect of being excellent in contamination resistance, weather resistance, chemical resistance, wear resistance and the like.

The present invention is described in detail below.
In the present invention, at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate is used as a raw material.
Examples of the aliphatic diisocyanate include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane (hereinafter referred to as HDI), 1,6-diisocyanato-2,2, and the like. Examples include 4-trimethylhexane, methyl 2,6-diisocyanatohexanoate (lysine diisocyanate), and 1,9-diisocyanatononane.
Examples of the alicyclic diisocyanate include 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (isophorone diisocyanate), 1,3-diisocyanatomethylcyclohexane (hydrogenated xylylene diisocyanate), bis ( 4-isocyanatocyclohexyl) methane (hydrogenated diphenylmethane diisocyanate), 1,4-diisocyanatocyclohexane and the like.

Among aliphatic diisocyanates and alicyclic diisocyanates, HDI, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate are preferable because they are easily available industrially. As the aliphatic diisocyanate and the alicyclic diisocyanate, an aliphatic diisocyanate in which the viscosity of the produced polyisocyanate compound is reduced is preferable, and HDI is most preferable.
In the present invention, monoalcohol having 1 to 20 carbon atoms is used. The lower limit of the carbon number of the monoalcohol is preferably 2, more preferably 3, and still more preferably 4. The upper limit is preferably 16, more preferably 12, even more preferably 9. If the number of carbon atoms is 1 or more, the dissolving power in the low polarity organic solvent can be exhibited. If it is 20 or less, the compatibility with the silicate compound is sufficient. Monoalcohol may be used alone or in combination of two or more. The monoalcohol used in the present invention may contain an ether group, an ester group or a carbonyl group in the molecule, but is preferably a monoalcohol comprising only a saturated hydrocarbon group. Furthermore, a monoalcohol having a branch is more preferable. Examples of such monoalcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol, isoamyl alcohol, 1-hexanol, 2- Hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1-hexanol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, cyclopentanol, cyclohexanol, Examples include methylcyclohexanol and trimethylcyclohexanol. Among them, isobutanol, n-butanol, isoamyl alcohol, 1-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, 1,3 , 5-trimethylcyclohexanol is more preferred because of its particularly excellent solubility in low-polar organic solvents.

  1-propanol, isobutanol, 1-butanol, isoamyl alcohol, pentanol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 3, 3, 5 -Trimethyl-1-hexanol is even more preferred because of its particularly excellent compatibility with silicate compounds. Isobutanol, 1-hexanol, 2-hexanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1-hexanol are soluble in low polar organic solvents, silicates The compatibility with the compound is very excellent and most preferable.

The polyisocyanate compound is obtained by polyisocyanating aliphatic diisocyanate, alicyclic diisocyanate or the like by a known technique.
The polyisocyanate compound used in the present invention has an allophanate group / isocyanurate group molar ratio of 90/10 to 70/30. The upper limit of the allophanate group / isocyanurate group molar ratio is more preferably 87/13, and still more preferably 85/15. The lower limit is more preferably 74/26, still more preferably 77/23, and still more preferably 80/20. When the molar ratio of the allophanate group to the isocyanurate group is 90/10 to 70/30, the curability, the solubility in the low polar organic solvent, and the compatibility with the silicate compound are sufficient.

The curing agent polyisocyanate composition used in the present invention is a polyisocyanate compound used in a two-component polyurethane composition or, if necessary, a silicate compound, an organic solvent, a curing accelerator catalyst, a pigment, a leveling agent, an oxidation agent. It is a mixture of various additives used in the technical field such as an inhibitor, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant.
The molar ratio of allophanate groups to isocyanurate groups can be determined by 1H-NMR. An example of a method for measuring a polyisocyanate compound using HDI and an isocyanate prepolymer obtained therefrom as a raw material by 1H-NMR is shown below.
Example of 1H-NMR Measurement Method: A polyisocyanate compound is dissolved in deuterium chloroform at a concentration of 10% by mass (0.03% by mass of tetramethylsilane is added to the polyisocyanate compound). As a chemical shift standard, a hydrogen signal of tetramethylsilane was set to 0 ppm. Measured by 1H-NMR, adjacent to an isocyanurate group at a signal of hydrogen atoms bonded to nitrogen of allophanate groups at about 8.5 ppm (1 mol of hydrogen atoms relative to 1 mol of allophanate groups) and at about 3.85 ppm. The signal area ratio of the hydrogen atom of the methylene group (6 mol of hydrogen atom relative to 1 mol of isocyanurate group) is measured.
Allophanate group / isocyanurate group = (signal area around 8.5 ppm) / (signal area around 3.85 ppm / 6)

  In addition, the uretdione body is not only low in solubility in a low-polar organic solvent, but is also easily dissociated by heat or the like to generate HDI. Therefore, it is preferable to reduce the content of the uretdione body. The content of the uretdione compound is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% with respect to the polyisocyanate compound which does not substantially contain an organic solvent, a silicate compound or various additives. It is below mass%. The content of the uretdione compound can be determined by measuring the ratio of the area of the peak having a molecular weight of about 336 in gel filtration chromatography (hereinafter referred to as GPC) with a differential refractometer. When there is a peak that hinders measurement near the peak of about 336, the peak height of the uretdione group of about 1770 cm −1 and the peak of the allophanate group of about 1720 cm −1 are measured using FT-IR. The ratio can also be obtained by a method of quantifying using an internal standard.

  The GPC measurement method will be described below. All the measured values related to the molecular weight of the polyisocyanate compound are measured by the following measuring method. Equipment used: HLC-8120 (manufactured by Tosoh Corporation), columns used: TSK GEL SuperH1000, TSK GEL SuperH2000, TSK GEL SuperH3000 (both manufactured by Tosoh Corporation), sample concentration: 5 wt / vol%, carrier: THF, detection method : Differential refractometer, outflow amount 0.6 ml / min. Column temperature 30 ° C.). GPC calibration curves are polystyrene (molecular weight 50000-2050 PSS-06 (Mw 50000), BK 13007 (Mp = 20000, Mw / Mn = 1.03), PSS-08 (Mw = 9000), PSS. -09 (Mw = 4000), 5040-35125 (Mp = 2050, Mw / Mn = 1.05) and 3 amounts of an isocyanurate of an HDI-based polyisocyanate compound (Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation) To 7-mer (isocyanurate trimer molecular weight = 504, isocyanurate pentamer molecular weight = 840, isocyanurate heptamer molecular weight = 1176) and HDI (molecular weight = 168) were prepared as standards.

When a large amount of urethane is contained, the crosslinking ability of the curing agent polyisocyanate composition containing the polyisocyanate compound is lowered, which is not preferable. The range of the amount of the urethane compound contained in the polyisocyanate compound of the present invention is preferably 10% by mass or less with respect to the polyisocyanate compound substantially not containing an organic solvent, a silicate compound or various additives, More preferably, it is 5% by mass or less, and still more preferably 3% by mass or less.
Furthermore, the biuret body and other diisocyanate polymers are not preferable because the solubility in a low-polar organic solvent and the compatibility with a silicate compound are lowered. The polyisocyanate compound of the present invention preferably has a biuret form and other diisocyanate polymers in an amount range, preferably with respect to a polyisocyanate compound substantially not containing an organic solvent, a silicate compound or various additives. 10 mass% or less, More preferably, it is 5 mass% or less, More preferably, 3 mass% or less is suitable.

The isocyanate group content (hereinafter referred to as NCO content) of the polyisocyanate compound used in the present invention is 10 to 22% by mass, preferably 13 in a state that does not substantially contain an organic solvent, diisocyanate, silicate compound and various additives. -21% by mass, more preferably 16-20% by mass. If it is the range of 10-22 mass%, it can fully melt | dissolve in a low polar organic solvent, and can obtain the hardening | curing agent polyisocyanate composition which has sufficient crosslinking | crosslinked property.
The viscosity of the polyisocyanate compound used in the present invention is preferably 50 to 500 mPa.s in a state that does not substantially contain an organic solvent, diisocyanate, silicate compound and various additives. s. The lower limit of the viscosity is more preferably 75 mPa.s. s, more preferably 100 mPa.s. s, still more preferably 120 mPa.s. s. The upper limit of the viscosity is more preferably 450 mPa.s. s, more preferably 400 mPa.s. s, more preferably 350 mPa.s. s, most preferably 300 mPa.s. s. If the viscosity of the polyisocyanate compound is 50 or more, a curing agent polyisocyanate composition having sufficient crosslinkability can be obtained, and 500 mPa.s. If it is s or less, it becomes possible to obtain a high-solid two-component polyurethane composition.

The number average functional group number (isocyanate group) of the polyisocyanate compound used in the present invention is preferably 2.10 to 2.50. The lower limit of the number average functional group number is more preferably 2.15, and still more preferably 2.20. The upper limit is more preferably 2.40, and still more preferably 2.35. When the number average functional group number is in the range of 2.10 to 2.50, the curability when formed into a coating film, the solubility in a low-polar organic solvent, and the compatibility with the silicate compound are improved.
The number average functional group number can be obtained by the following formula.
Number average functional group number = number average molecular weight × NCO content (%) / 4200
The number average molecular weight can be determined by GPC measurement.
The manufacturing method of the polyisocyanate compound used by this invention is demonstrated.

As a method for producing the polyisocyanate compound used in the present invention, the following three methods may be mentioned.
(1) A method in which a C1-20 monoalcohol and a diisocyanate are subjected to a urethanization reaction, and thereafter or simultaneously, an allophanatization reaction and an isocyanurate formation reaction are performed to obtain a target polyisocyanate compound.
(2) C1-20 monoalcohol and diisocyanate were subjected to urethanization reaction, and thereafter, or simultaneously, allophanatization reaction was performed, and the resulting polyisocyanate compound having an allophanate group and diisocyanate were obtained by isocyanuration reaction. A method of obtaining a target polyisocyanate compound by mixing a polyisocyanate compound having an isocyanurate group.

(3) A C1-20 monoalcohol and a diisocyanate are subjected to a urethanization reaction, and thereafter, or simultaneously, an allophanate reaction and an isocyanurate reaction, and a polyisocyanate compound containing the obtained allophanate group and isocyanurate group; A method in which a C1-20 monoalcohol and a diisocyanate are subjected to a urethanization reaction, and then or simultaneously, an allophanatization reaction is performed, and the obtained polyisocyanate compound having an allophanate group is mixed to obtain a target polyisocyanate compound.
Since the method (1) can be manufactured by one process, it has a feature that production efficiency is good. In the methods (2) and (3), a polyisocyanate compound having an isocyanurate structure or a polyisocyanate compound having an isocyanurate structure and an allophanate structure and a polyisocyanate compound having an allophanate group can be mixed in any ratio. Therefore, there is a feature that the physical properties of the obtained polyisocyanate compound can be easily adjusted.

Any method may be used as long as the molar ratio between the allophanate group and the isocyanurate group is 90/10 to 70/30.
The urethanization reaction is preferably 20 to 200 ° C., more preferably 40 to 150 ° C., even more preferably 60 to 120 ° C., preferably 10 minutes to 24 hours, more preferably 15 minutes to 15 hours, even more preferably. Is performed for 20 minutes to 10 hours. The reaction is fast at 20 ° C. or higher, side reactions such as uretdione formation are suppressed at 200 ° C. or lower, and coloring is also suppressed. If the time is 10 minutes or more, the reaction can be completed. If the time is 24 hours or less, there is no problem in production efficiency, and side reactions are also suppressed. The urethanization reaction can be carried out without a catalyst or in the presence of a catalyst such as tin or amine.

The allophanatization reaction is preferably performed at a temperature of 20 to 200 ° C. More preferably, it is 40-180 degreeC, More preferably, it is 60-160 degreeC. Still more preferably, it is 90-150 degreeC, Most preferably, it is 110-150 degreeC. Above 20 ° C., the amount of allophanatization catalyst decreases and the time required to complete the reaction is short. Further, at 200 ° C. or lower, side reactions such as uretdione formation are suppressed, and coloring of the reaction product is suppressed.
The reaction time of the allophanatization reaction is preferably 10 minutes to 24 hours, more preferably 15 minutes to 12 hours, even more preferably 20 minutes to 8 hours, and even more preferably 20 minutes to 6 hours. If the reaction time is 10 minutes or more, the reaction can be controlled, and if it is within 24 hours, the production efficiency is sufficient. When the reaction temperature exceeds 130 ° C., uretdione may be generated as a side reaction. Therefore, the reaction time is preferably within 8 hours, more preferably within 6 hours, and even more preferably within 4 hours. .

The isocyanuration reaction, or allophanatization and isocyanuration reaction is preferably performed at a temperature of 20 to 180 ° C. More preferably, it is 30-160 degreeC, More preferably, it is 40-140 degreeC. Still more preferably, it is 60-130 degreeC, Most preferably, it is 80-110 degreeC. At 20 ° C. or higher, the amount of the catalyst is reduced, and side reactions such as nylon reaction are less likely to occur. Further, at 180 ° C. or lower, side reactions such as uretdione formation are suppressed, and coloring of the reaction product is suppressed.
The reaction time of the isocyanuration reaction, or allophanation and isocyanuration reaction is preferably 10 minutes to 24 hours, more preferably 15 minutes to 12 hours, even more preferably 20 minutes to 8 hours, and still more preferably 20 Min ~ 6 hours is good. If the reaction time is 10 minutes or more, the reaction can be controlled, and if it is within 24 hours, the production efficiency is sufficient.

When the method (1) is adopted, it is preferable to use a catalyst for the allophanate reaction and isocyanurate reaction, and in particular, the molar ratio of allophanate group / isocyanurate group of the polyisocyanate to be produced is 70/30 to 90/10. It is preferable to select a catalyst that yields Examples of such catalysts include zinc carboxylates, bismuth carboxylates, alkoxides such as zinc, tin, zirconium and zirconyl.
When the method (2) or (3) is employed to produce a polyisocyanate having an allophanate group, the allophanate reaction is preferably performed using a catalyst, and more preferably a catalyst having a high allophanate group selectivity, more preferably It is preferable to select a catalyst in which the ratio of allophanate groups / isocyanurate groups of the polyisocyanate to be produced is 90/10 to 100/0. Examples of such a catalyst include lead, tin, zirconyl, zirconium carboxylate, and a mixture thereof.

When the method (2) is employed to produce a polyisocyanate containing an isocyanurate group, it is preferable to use a catalyst for the isocyanurate formation reaction. Examples of the isocyanurate-forming catalyst include tetraalkylammonium, hydroxyalkylammonium, carboxylates of alkali metal salts, hydroxides, aminosilyl group-containing compounds, and the like, or mixtures thereof.
When the method (3) is employed to produce a polyisocyanate containing an allophanate group and an isocyanurate group, it is preferable to use a catalyst for the allophanate reaction and the isocyanurate reaction. Examples of the allophanatization and isocyanuration catalyst include tetraalkylammonium, hydroxyalkylammonium, carboxylates of alkali metal salts, hydroxides, aminosilyl group-containing compounds, and the like, or mixtures thereof. In particular, it is preferable that the selectivity of allophanate formation is moderately high because the possibility of remaining urethane groups is low, and therefore the ratio of allophanate groups / isocyanurate groups of the polyisocyanate to be produced is more preferably 40/60 to 70/30. The catalyst which becomes is good. Such catalysts include tetraalkylammonium, hydroxyalkylammonium carboxylates, or mixtures thereof.

The amount of the allophanate catalyst, isocyanurate catalyst, allophanate catalyst and isocyanurate catalyst is preferably 0.001 to 2.0% by mass, more preferably 0.01 to 2.0%, based on the total mass of the reaction solution. Used in an amount of 0.5% by weight. The effect of the catalyst can be sufficiently exerted at 0.001% by mass or more. Control of the allophanatization reaction is easy at 2% by weight or less.
In the present invention, the method for adding the allophanate catalyst, isocyanurate catalyst, allophanate catalyst and isocyanurate catalyst is not limited. For example, in the case of an allophanatization catalyst, allophanate formation and isocyanurate formation catalyst, it may be added before the production of a compound containing a urethane group, that is, prior to the urethanization reaction of an organic compound having a diisocyanate and a hydroxyl group. And may be added during the urethanization reaction of the organic compound having a hydroxyl group, or after the urethane group-containing compound is produced. In addition, as a method of addition, a required amount of the allophanatization catalyst may be added all at once, or may be added in several divided portions. Or the method of adding continuously at a fixed addition rate is also employable.

The urethanization reaction, allophanate reaction, isocyanurate reaction, allophanate reaction and isocyanurate reaction proceed in the absence of a solvent, but if necessary, in addition to the above-mentioned low polar organic solvents, ethyl acetate, butyl acetate, etc. Ester solvents, ketone solvents such as methyl ethyl ketone, aromatic solvents such as toluene, xylene, and diethylbenzene, organic solvents that are not reactive with isocyanate groups such as dialkyl polyalkylene glycol ethers, and mixtures thereof Can be used as
The process of urethanization reaction, allophanate reaction, isocyanurate reaction, allophanate reaction, and isocyanurate reaction in the present invention can be traced by measuring the NCO content of the reaction solution or measuring the refractive index.

  The allophanate reaction, isocyanurate reaction, allophanate reaction and isocyanurate reaction can be stopped by cooling to room temperature or adding a reaction terminator, but when using a catalyst, it is better to add a reaction terminator. It is preferable because side reactions can be suppressed. The amount of the reaction terminator added is preferably 0.25 to 20 times the molar amount, more preferably 0.5 to 16 times the molar amount, still more preferably 1.0 to 12 times the catalyst. Molar amount. It becomes possible to completely deactivate at 0.25 times or more. Storage stability becomes good at 20 times or less. Any reaction terminator may be used as long as it deactivates the catalyst. Examples of reaction terminators include phosphoric acid, pyrophosphoric acid and other phosphoric acid compounds, phosphoric acid, monoalkyl or dialkyl esters such as pyrophosphoric acid, halogenated acetic acid such as monochloroacetic acid, benzoyl chloride, sulfonic acid ester, Examples include sulfuric acid, sulfuric ester, ion exchange resin, chelating agent and the like. From an industrial viewpoint, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphoric acid monoalkyl ester, and phosphoric acid dialkyl ester are preferable because they hardly corrode stainless steel. Examples of phosphoric acid monoesters and phosphoric acid diesters include phosphoric acid monoethyl ester, phosphoric acid diethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, phosphoric acid mono (2-ethylhexyl) ester, and phosphoric acid diester. (2-ethylhexyl) ester, phosphate monodecyl ester, phosphate didecyl ester, phosphate monolauryl ester, phosphate dilauryl ester, phosphate monotridecyl ester, phosphate ditridecyl ester, phosphate monooleyl ester, Examples thereof include phosphate dioleyl ester and mixtures thereof.

  In addition, it is also preferable to stop the reaction using an adsorbent or to combine and stop the adsorbent and the above-mentioned reaction stopper. Examples of the adsorbent include silica gel and activated carbon. The amount of adsorbent added is preferably 1.4 to 3000 times the mass of the catalyst, more preferably 7.0 to 1500 times the mass, and even more preferably 10.0 to 700 times the mass. Mass. If it is 1.4 times or more, it has sufficient ability to adsorb the catalyst remaining in the polyisocyanate compound, the thermally deactivated catalyst, the reaction product of the reaction terminator and the catalyst, the unreacted reaction terminator, and the like. If it is 2 times or less, it is easy to remove the adsorbent from the polyisocyanate compound.

After completion of the reaction, unreacted diisocyanate and solvent may be separated from the polyisocyanate compound. In view of safety, it is preferable to separate unreacted diisocyanate. Examples of a method for separating unreacted diisocyanate and solvent include a thin film distillation method and a solvent extraction method.
In the reaction in the present invention, a urethanization reaction and an allophanatization reaction can be performed in one reactor. Moreover, two reactors can be connected, and the urethanization reaction step and the allophanatization reaction step can be carried out separately. Alternatively, it can be carried out continuously by arranging several reactors side by side.

Next, the main component polyol composition will be described in detail.
In the present invention, acrylic polyol, polyester polyol, or polyether polyol is used as the main component polyol composition. These may be used alone or in combination. Furthermore, an acrylic polyol, a polyester polyol, or a polyether polyol may be mixed with another resin. Examples of other resins include aliphatic hydrocarbon polyols, silicon-containing polyols, polycarbonate polyols, epoxy resins, and alkyd polyols.
The main component polyol composition of the present invention includes an acrylic polyol, a polyester polyol, and a polyether polyol modified with an aliphatic diisocyanate, an alicyclic diisocyanate, or a polyisocyanate compound obtained therefrom, and a urethane-modified acrylic polyol or urethane-modified polyol. Polyester polyols and urethane modified polyether polyols can also be used.
The main component polyol composition used in the present invention preferably has a hydroxyl group of 5 to 350 mgKOH / g, preferably 10 to 300 mgKOH / g, more preferably 20 to 250 mgKOH / g. If the hydroxyl value is 5 mgKOH / g or more, a tough coating film can be obtained. If it is 350 mgKOH / g or less, a smooth coating film can be obtained.

Hereinafter, the manufacturing method of a main ingredient polyol composition is described.
The acrylic polyol can be produced, for example, by copolymerizing a polymerizable monomer having one or more active hydrogens in one molecule and another monomer copolymerizable therewith. For example, acrylic acid esters having active hydrogen such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate, or 2-hydroxyethyl methacrylate and methacrylic acid-2- Methacrylic acid esters having active hydrogen such as hydroxypropyl, methacrylic acid-2-hydroxybutyl, methacrylic acid-3-hydroxypropyl, methacrylic acid-4-hydroxybutyl, or triol monoacrylate such as glycerin and trimethylolpropane (Meth) acrylic acid esters having polyvalent active hydrogen such as ester or methacrylic acid monoester, polyether polyols such as polyethylene glycol, polypropylene glycol, polybutylene glycol and the above active hydrogen A (meth) monoether of acrylic acid esters, glycidyl (meth) acrylate and acetic acid, propionic acid, adducts of monobasic acids such as p-tert-butylbenzoic acid,

  Alternatively, a single or mixture selected from the group of adducts obtained by ring-opening polymerization of lactones such as ε-caprolactam and γ-valerolactone to active hydrogens of (meth) acrylic acid esters having active hydrogen as described above As an essential component, as required, acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, -n-butyl acrylate, 2-ethylhexyl acrylate, or methyl methacrylate, ethyl methacrylate, Methacrylic acid esters such as isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, maleic acid, itacon Acid etc. Unsaturated carboxylic acids, unsaturated amides such as acrylamide, N-methylolacrylamide, diacetone acrylamide, etc., or hydrolyzable silyl such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acrylopropyltrimethoxysilane A vinyl monomer having a group, styrene, vinyl toluene, vinyl acetate, acrylonitrile, a single or a mixture selected from the group of other polymerizable monomers such as dibutyl fumarate, can be obtained by copolymerizing by a conventional method. it can. For example, the monomer component can be obtained by solution polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound.

  Examples of the method for producing polyester polyol include dibasic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and carboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Alone or in combination with ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, 1,2-, 1,3- and 1,4-cyclohexane It can be obtained by performing a known condensation reaction with a diol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, or a polyhydric alcohol such as ethoxylated trimethylolpropane alone or in a mixture. For example, it can be done by combining the above ingredients and heating at about 160-220 ° C. Furthermore, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone using a polyhydric alcohol can also be used as the polyester polyol.

  As a manufacturing method of polyether polyol, polyhydric alcohol, polyhydric phenol, polyamine, alkanolamine, etc., specifically, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4- Dihydric alcohols such as butanediol, 1,6-hexanediol, and bisphenol A, trihydric alcohols such as glycerin and trimethylolpropane, and diamines such as ethylenediamine, alone or in a mixture, for example, hydroxides such as lithium, sodium, and potassium , Strongly basic catalysts such as alcoholates and alkylamines, metal porphyrins, complex metal cyanide complexes, complexes of metals with tridentate or higher chelating agents, complex metal complexes such as zinc hexacyanocobaltate complexes Use, ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, obtained by adding, alone or mixtures of alkylene oxides such as styrene oxide.

Next, the two-component polyurethane composition of the present invention containing the main component polyol composition and the curing agent polyisocyanate composition will be described. The equivalent ratio (NCO / OH ratio) of isocyanate groups and hydroxyl groups of the main component polyol composition and the curing agent polyisocyanate composition used in the present invention is 0.2 to 5.0, preferably 0.4 to 3.0. More preferably, 0.5 to 2.0 is appropriate. If it is 0.2 or more, a tough coating film can be obtained. If it is 5.0 or less, a smooth coating film can be obtained.
Any of the main component polyol composition, curing agent polyisocyanate composition, and two-component polyurethane composition used in the present invention can be used by mixing with an organic solvent. In this case, the organic solvent preferably does not have a functional group that reacts with a hydroxyl group and an isocyanate group. The organic solvent is preferably compatible with the main component polyol composition, curing agent polyisocyanate composition, and two-component polyurethane composition used in the present invention. As such organic solvents, ester compounds, ether compounds, ketone compounds, aromatic compounds, ethylene glycol dialkyl ether compounds, polyethylene glycol dicarboxylate compounds, hydrocarbon solvents generally used as paint solvents An aromatic solvent or the like may be used.

Among them, the main component polyol composition dissolved in the low-polar organic solvent or the dispersed main component polyol composition of the so-called NAD (non-water-dispersible acrylic resin) system erodes the old coating film during the repainting operation. It is preferable because it is difficult.
The curing agent polyisocyanate composition or the main component polyol composition of the present invention can contain a low polarity organic solvent. The low polarity organic solvent is an organic solvent containing an aliphatic or alicyclic hydrocarbon solvent as a main component, and the low polarity organic solvent used in the present invention has an aniline point of 10 to 70 ° C. The low polarity organic solvent used in the present invention may contain an aromatic hydrocarbon solvent, an ester solvent, an ether solvent, or the like.
The lower limit of the aniline point of the low polarity organic solvent used in the present invention is preferably 12 ° C, more preferably 15 ° C. The upper limit is preferably 65 ° C, more preferably 60 ° C. If the aniline point is 10 ° C. or higher, the base coating film is hardly affected, and if it is 70 ° C. or lower, the polyisocyanate can be dissolved.

  Examples of the low polarity organic solvent used in the present invention include methylcyclohexane (aniline point 40 ° C.), ethylcyclohexane (aniline point 44 ° C.), mineral spirit (mineral terpene) (aniline point 56 ° C.), turpentine oil (aniline point 20 ° C.). In addition to HAWS (manufactured by Shell Japan, aniline point 17 ° C.), Essonaphtha No. 6 (manufactured by ExxonMobil Chemical, aniline point 43 ° C), LAWS (manufactured by Shell Japan, aniline point 44 ° C), pegasol 3040 (manufactured by ExxonMobil Chemical, aniline point 55 ° C), A solvent (Shin Nippon Petrochemical Co., Ltd., aniline) 45 ° C), Clensol (Shin Nippon Petrochemical Co., Ltd., aniline point 64 ° C), Mineral Spirit A (Shin Nippon Petrochemical Co., Ltd., aniline point 43 ° C), Hyalom 2S (Shin Nippon Petrochemical Co., Ltd.) An aniline point of 44 ° C.), or a mixture of at least one of these low-polar organic solvents and, if necessary, an aromatic hydrocarbon solvent, an ester solvent, an ether solvent, or the like.

  In recent years, the demand for repainting has increased, and there is an increasing demand for dilution of solvents that do not easily attack the underlying coating film, that is, low-polar organic solvents that have a much lower dissolving power. In such a case, the lower limit of the aniline point is preferably 30 ° C, more preferably 40 ° C. Specific examples of such low polarity organic solvents include LAWS (manufactured by Shell Chemicals Japan, aniline point 44 ° C.), Pegasol 3040 (manufactured by ExxonMobil Co., Ltd., aniline point 55 ° C.), A solvent (Shin Nippon Petrochemical) Co., Ltd., aniline point 45 ° C), Clensol (Shin Nippon Petrochemical Co., Ltd., aniline point 64 ° C), Mineral Spirit A (Shin Nippon Petrochemical Co., Ltd., aniline point 43 ° C), Hyalom 2S (Shin Nippon Oil Chemical Co., Ltd., aniline point 44 ° C), Linearlen 10, Linearlen 12 (Idemitsu Petrochemical Co., Ltd., α-olefin hydrocarbon, aniline point 44 ° C, 54 ° C), Exol D30 (Exxon Mobil Co., Ltd., naphthenic) Solvent, aniline point 63 ° C), Ricasolve 900, 910B, 1000 (Nippon Nippon Chemical Co., Ltd.) Company Ltd., hydrogenated C9 solvent, aniline point 53 ℃, 40 ℃, 55 ℃), etc. are preferable. Even if these low-polar organic solvents are mixed with an aromatic solvent, an ether solvent, an ester solvent or the like, the mixed solvent may be within the range of the aniline point. The aniline point may be measured according to the aniline point test method described in JIS K 2256.

  Furthermore, it is often required that the solvent be dissolved in a low-polar organic solvent that does not contain a so-called PRTR (chemical substance transfer and transfer registration) target substance such as toluene, xylene, 1,3,5-trimethylbenzene. In such a case, it is more preferable to use a low-polar organic solvent that does not contain a PRTR target substance. Specific examples of such low-polar organic solvents include α-olefinic hydrocarbons (such as Nylarene 10 and linearene 12), naphthenic solvents having a relatively low aniline point (such as Exol D30), hydrogenated solvents (Lycasolve 900, 910B, 1000 etc.). Alternatively, an isoparaffinic, naphthenic, or paraffinic solvent having an aniline point exceeding 70 ° C may be mixed with an ether or ester solvent to adjust the aniline point to 10 ° C to 70 ° C. Examples of the isoparaffin-based solvent include Shellsol S (manufactured by Shell Chemicals Japan Co., Ltd., aniline point 78 ° C.), Isopar G (manufactured by ExxonMobil Co., Ltd., aniline point 78 ° C.), Nippon Oil Isosol 300 (Shin Nippon Petrochemical Co., Ltd.) Company-made, aniline point 80 ° C.). Examples of the naphthenic solvent include Exol D40 (manufactured by ExxonMobil Co., Ltd., aniline point 69 ° C.), Naphthezol 160 (manufactured by Nippon Petrochemical Co., Ltd., aniline point 69 ° C.), IP solvent 1016, 1620 (Idemitsu Petrochemical Co., Ltd.) (Manufactured by company, aniline point 72 ° C., 81 ° C.) and the like. Examples of the paraffinic solvent include normal paraffin SL (manufactured by Shin Nippon Petrochemical Co., Ltd., aniline point 80 ° C.). Examples of ester solvents and ether solvents include ethyl acetate, butyl acetate, and methoxypropyl acetate.

In the curing agent polyisocyanate composition of the present invention containing a low polar organic solvent, the mass ratio of the polyisocyanate compound and the low polar organic solvent is preferably 5/95 to 95/5. The lower limit of the mass ratio of the polyisocyanate compound and the low polarity organic solvent is more preferably 10/90, and even more preferably 15/85. The upper limit of the mass ratio is more preferably 90/10, still more preferably 85/15.
The curing agent polyisocyanate composition of the present invention contains at least one silicate compound selected from a tetraalkoxysilane represented by the following formula ( 1 ), a condensate of tetraalkoxysilane, and a tetraalkoxysilane derivative. I can do it.

By containing a silicate compound, when a coating film is produced in combination with the main component polyol composition, the coating film surface is made hydrophilic and rain-stain stain resistance is exhibited.
R in the formula is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group. The upper limit of the carbon number is preferably 8, more preferably 6, still more preferably 4. R is preferably an alkyl group.
When R is an alkyl group, it may be either linear or branched, but is more preferably linear.
When R is an aryl group, it may be monocyclic or polycyclic, but is preferably monocyclic.

Examples of such tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-tert-butoxysilane, and dimethoxy. Examples thereof include diethoxysilane, tetraphenoxysilane, and condensates thereof. Among these, the condensate of tetramethoxysilane and the condensate of tetraethoxysilane are preferable because the surface of the coating film tends to be hydrophilic when the coating film is prepared.
Furthermore, a tetraalkoxysilane condensate in which two or more types of alkoxyl groups having different carbon numbers are mixed can be used as the silicate compound. This is because the tetramethoxysilane condensate, or the methoxy group or ethoxy group of the tetraethoxysilane condensate, more preferably 5 to 50 mol% of the methoxy group of the tetramethoxysilane condensate is substituted with an alkoxyl group having 3 to 10 carbon atoms. This is a method using a compound. The ratio of substituting the methoxy group and the ethoxy group with an alkoxyl group having 3 to 10 carbon atoms is more preferably 8 to 40 mol%, still more preferably 12 to 35 mol%. The substituted alkoxyl group is preferably a butyl group, a pentyl group, a hexyl group, or an octyl group, and more preferably an n-butyl group, an isobutyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, 2-ethyl-1-hexyl group. Such a silicate compound is very preferable because it has a high hydrophilicity in the case where the coating film is formed and a high solubility in a low-polar organic solvent.

In the curing agent polyisocyanate composition of the present invention containing a silicate compound, the mass ratio of the polyisocyanate compound and the silicate compound is preferably 5/95 to 95/5. The lower limit of the mass ratio of the polyisocyanate compound and the silicate compound is more preferably 10/90, still more preferably 15/85. The upper limit is more preferably 90/10, still more preferably 85/15.
In the two-component polyurethane composition of the present invention, a curing accelerating catalyst, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, and a light stabilizer are used in a range that does not impair the effects of the present invention, depending on the purpose and application. Various additives used in the technical field such as an agent, a plasticizer, and a surfactant can also be mixed and used. These may be contained in any of the main component polyol composition, the curing agent polyisocyanate composition, and the two-component polyurethane composition.

Examples of curing accelerating catalysts include metal salts such as dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, cobalt salt, triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N-dimethyl And tertiary amines such as cyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N, N′-endoethylenepiperazine, and N, N′-dimethylpiperazine.
Antioxidants, ultraviolet absorbers, light stabilizers and the like prevent deterioration of the main component polyol composition and curing agent polyisocyanate composition over time. Examples of the antioxidant include dibutylhydroxytoluene (BHT), butylhydroxyanisole, tocopherol and the like. Examples of ultraviolet absorbers include benzotriazole ultraviolet absorbers. Examples of light stabilizers include hindered amine light stabilizers (HALS). Of these, HALS is most effective and particularly preferred for the two-component polyurethane composition of the present invention.

The two-component polyurethane composition of the present invention is obtained from at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate, and a monoalcohol having 1 to 20 carbon atoms, and has a molar ratio of allophanate group / isocyanurate group. A coating film obtained using a curing agent polyisocyanate composition having a ratio of 90/10 to 70/30 and a main component polyol composition containing an acrylic polyol, a polyester polyol or a polyether polyol has a good appearance and excellent It has the characteristics of having excellent weather resistance and excellent scratch resistance.
The two-component polyurethane composition of the present invention uses either a curing agent polyisocyanate composition using a polyisocyanate compound that dissolves in a low-polar organic solvent or a main component polyol composition that dissolves in a low-polar organic solvent. In the case where both or both of them are used, the low-polar organic solvent has a low dissolving power, so that it is difficult to attack the base. That is, when the two-component polyurethane composition of the present invention is directly applied without removing the old coating film or applying a sealing agent during the repainting operation, lifting is unlikely to occur. In addition, when performing repair work and overcoating work, it is possible to perform overcoating without affecting the underlying coating film. Furthermore, the low polar organic solvent often has a property of low odor, and has a feature that it is difficult to cause odor to a painter or a nearby person.

Further, the polyisocyanate compound used in the present invention also has a characteristic of very low viscosity, and when it is a two-pack type polyurethane composition, it becomes possible to reduce the VOC (volatile organic compound) component.
Furthermore, the two-component polyurethane composition of the present invention is a curing agent polyisocyanate composition, or a main component polyol composition, or both a curing agent polyisocyanate composition and a main component polyol composition, or a two-component polyurethane composition. When the silicate compound is blended during production, the coating film surface becomes hydrophilic after coating and drying, and therefore, it has a feature of excellent rain-stain stain resistance. However, it is not preferable to add a silicate compound to the main component polyol composition because the hydroxyl group of the main component polyol composition reacts with the silicate compound.

Therefore, the two-component polyurethane composition of the present invention can be used for paints, inks, adhesives, casting materials, elastomers, foams, and plastic materials. Among these, it is suitable for paints and adhesives, and particularly suitable for paints. In addition, the two-component polyurethane composition of the present invention is required to have stain resistance, weather resistance, chemical resistance, and abrasion resistance. Architectural paints, heavy anticorrosion paints, automotive paints, household paints, personal computers, Suitable for paints for information devices such as mobile phones. Among them, it is suitable for architectural paints and heavy anticorrosion paints, and particularly suitable for architectural exterior paints for repainting applications.
Examples of the synthesis method of the polyisocyanate compound used in the present invention, the preparation method of the curing agent polyisocyanate composition, the synthesis method of the main component polyol composition, and the two-component polyurethane composition of the present invention will be described below.

  The number average molecular weight, weight average molecular weight, etc. are as follows: GPC (equipment used: HLC-8120 (manufactured by Tosoh Corporation), column used: TSK GEL SuperH1000, TSK GEL SuperH2000, TSK GEL SuperH3000 (all manufactured by Tosoh Corporation), sample concentration : 5 wt / vol%, carrier: THF, detection method: differential refractometer, flow rate 0.6 ml / min, column temperature 30 ° C.). GPC calibration curves are polystyrene (molecular weight 50000-2050 PSS-06 (Mw 50000), BK 13007 (Mp = 20000, Mw / Mn = 1.03), PSS-08 (Mw = 9000), PSS. -09 (Mw = 4000), 5040-35125 (Mp = 2050, Mw / Mn = 1.05) and 3 amounts of an isocyanurate of an HDI-based polyisocyanate compound (Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation) To 7-mer (isocyanurate trimer molecular weight = 504, isocyanurate pentamer molecular weight = 840, isocyanurate heptamer molecular weight = 1176) and HDI (molecular weight = 168) were prepared as standards.

The mole fraction of allophanate groups was determined by using 1H-NMR (FT-NMR DPX-400 manufactured by Bruker), hydrogen signal on the nitrogen atom of allophanate groups near 8.5 ppm, and isocyanurate near 3.8 ppm. It was determined from the area of the hydrogen signal of the methylene group next to the nitrogen atom of the isocyanurate ring of the group.
NCO% was determined by back titration with 1N hydrochloric acid after neutralizing the isocyanate group with excess 2N amine.
The viscosity was measured at 25 ° C. using an E-type viscometer (manufactured by Tokimec Co., Ltd.).
A standard rotor (1 ° 34 ′ × R24) was used. The number of revolutions is as follows.
100r. p. m. (If less than 128 mPa.s)
50r. p. m. (In the case of 128 mPa.s to 256 mPa.s)
20r. p. m. (In the case of 256 mPa.s to 640 mPa.s)
10r. p. m. (In the case of 640 mPa.s to 1280 mPa.s)
5r. p. m. (In the case of 1280 mPa.s to 2560 mPa.s)

The low polarity organic solvent solubility is obtained by gradually adding the low polarity organic solvent to the polyisocyanate compound with stirring under the condition of 20 ° C., measuring the mass when it starts to become cloudy, and obtaining by the following formula: It was.
Low polar organic solvent solubility (%) = ((mass of low polar organic solvent when starting to become cloudy (g) × 100%) / (mass of polyisocyanate compound (g))
Silicate compatibility is 20 ° C under low-polarity organic solvent “HAWS” (trade name, aniline point 17 ° C., Shell Japan) or “A-solvent” (trade name) so that the NCO content is 10%. The silicate compound was added to the sample diluted at an aniline point of 45 ° C. (manufactured by Shin Nippon Petrochemical Co., Ltd.), and the mass at the time when turbidity began to be measured was determined by the following formula.
Silicate compatibility (%) = ((mass of silicate compound when starting to become cloudy (g) × 100%) / mass of sample (g))
The gel fraction was determined from the mass of a coating film obtained by immersing about 0.1 g of a coating film in acetone at 20 ° C. for 24 hours, taking out the coating film, and drying at 80 ° C. for 1 hour.

“Synthesis Example 1”
The inside of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was purged with nitrogen, 1000 g of HDI and 100 g of isobutanol were charged, and a urethanization reaction was performed at 90 ° C. for 1 hour with stirring. 20% mineral spirit solution of bismuth 2-ethylhexanoate as an allophanate / isocyanurate catalyst at 90 ° C. (diluted by Nippon Chemical Industry Co., Ltd., trade name “Nikka Octix Bismuth 25%” with mineral spirits) 10 g) was added. When the increase in the refractive index of the reaction solution was 0.01, 4.5 g of phosphoric acid 2-ethylhexyl ester (manufactured by Johoku Chemical Co., Ltd., trade name “JP-508”) (8.0 to the catalyst). The reaction was stopped by adding 1 mol).

After filtering the reaction solution, unreacted HDI was removed at 160 ° C. (27 Pa) for the first time and 150 ° C. (13 Pa) for the second time using a flow-down type thin-film distillation apparatus.
The obtained polyisocyanate compound was a transparent liquid, yield 429 g, viscosity 160 mPa.s. s, NCO content was 17.8%. When NMR was measured, the allophanate / isocyanurate molar ratio was 84/16. Let the obtained polyisocyanate compound be P-1. In the present invention, “%” means “% by mass” unless otherwise specified.
P-1 was tested for solubility in low polarity organic solvents. The solubility of HAWS (manufactured by Shell Chemicals Japan, aniline point 15 ° C.) was> 2000%. The solubility of the A solvent (manufactured by Nippon Petrochemical Co., Ltd., aniline point 45 ° C.) was> 2000%, and the solubility of Pegasol 3040 (manufactured by ExxonMobil Co., Ltd., aniline point 55 ° C.) was> 2000%.
The silicate compatibility of P-1 was tested. Compatibility with MKC silicate MS58B15 (trade name, condensate of butyl-modified methyl silicate, manufactured by Mitsubishi Chemical Corporation) is> 500%, MKC silicate MS58B30 (trade name, condensate of butyl-modified methyl silicate, Mitsubishi Chemical Corporation) Compatibility) was> 500%.

“Synthesis Example 2”
In the same apparatus as in Synthesis Example 1, 2700 g of HDI and 132 g of isobutanol were charged and subjected to urethanization reaction at 130 ° C. for 1 hour with stirring. As an allophanatization catalyst, 0.55 g of 20% solid spirit solution of zirconyl 2-ethylhexanoate (manufactured by Nippon Kagaku Sangyo Co., Ltd., trade name “Nikka Octix Zirconium 12%” diluted with mineral spirit) was added. . When the increase in the refractive index of the reaction solution reached 0.0055, 0.32 g of 2-ethylhexyl phosphate (4.1 times mol with respect to the catalyst) was added to stop the reaction.
After filtration of the reaction solution, unreacted HDI was removed in the same manner as in Synthesis Example 1.
The obtained polyisocyanate compound was a transparent liquid, yield 737 g, viscosity 110 mPa.s. s, NCO content was 19.4%. When NMR was measured, the molar ratio of allophanate group / isocyanurate group was 97/3. Let the obtained polyisocyanate compound be M-1.

“Synthesis Example 3”
In the same apparatus as in Synthesis Example 1, 2700 g of HDI and 210 g of 2-ethylhexanol were charged, and a urethanization reaction was performed at 130 ° C. for 1 hour with stirring. As an allophanatization catalyst, 0.54 g of a 20% solid spirit solution of zirconyl 2-ethylhexanoate in a solid content was added. When the increase in the refractive index of the reaction solution reached 0.0055, a 50% isobutanol solution of dodecyl phosphate (Johoku Chemical Co., Ltd., trade name “JP-512” diluted with isobutanol) 0.81 g (4.0 moles relative to the catalyst) was added to stop the reaction.
After filtration of the reaction solution, unreacted HDI was removed in the same manner as in Synthesis Example 1.
The obtained polyisocyanate compound was a transparent liquid, yield 770 g, viscosity 110 mPa.s. s, NCO content was 17.2%. When NMR was measured, the molar ratio of allophanate group / isocyanurate group was 97/3. Let the obtained polyisocyanate compound be M-2.

“Synthesis Example 4”
In the same apparatus as in Synthesis Example 1, 1000 g of HDI and 50 g of isobutanol were charged, and a urethanization reaction was performed at 90 ° C. for 1 hour with stirring. As an allophanatization and isocyanurate formation catalyst, 0.53 g of a solid content 10% n-butanol solution of tetramethylammonium caprate was added. When the increase in the refractive index of the reaction solution reached 0.015, 0.10 g of an aqueous solution containing 85% solid content of phosphoric acid (4.0 times moles relative to the catalyst) was added to stop the reaction.
After filtration of the reaction solution, unreacted HDI was removed in the same manner as in Synthesis Example 1.
The obtained polyisocyanate compound was a transparent liquid, yield 440 g, viscosity 450 mPa.s. s, NCO content was 19.6%. When NMR was measured, the molar ratio of allophanate / isocyanurate was 60/40. Let the obtained polyisocyanate compound be M-3.

“Synthesis Example 5”
In the same apparatus as in Synthesis Example 1, 1000 g of HDI and 30 g of 2-ethylhexanol were charged, and a urethanization reaction was performed at 90 ° C. for 1 hour with stirring. As an allophanatization and isocyanurate formation catalyst, 0.36 g of a solid content 10% n-butanol solution of tetramethylammonium caprate was added. When the increase in the refractive index of the reaction solution reached 0.01, 0.58 g of an aqueous solution containing 85% solid content of phosphoric acid (4.0 times moles relative to the catalyst) was added to stop the reaction.
After filtration of the reaction solution, unreacted HDI was removed in the same manner as in Synthesis Example 1.
The obtained polyisocyanate compound was a transparent liquid, yield 300 g, viscosity 450 mPa.s. s, NCO content was 20.6%. When NMR was measured, the molar ratio of allophanate / isocyanurate was 35/65. Let the obtained polyisocyanate compound be M-4.
“Synthesis Examples 6-8”
M-1 to M-4 obtained above were mixed to synthesize polyisocyanate compounds P-2 to P-4. The obtained polyisocyanate compound is shown in Table 1.

“Synthesis Example 9”
In a four-necked flask equipped with a stirrer, thermometer, and cooling tube, 120.0 g of a hydrocarbon solvent (trade name “Solvesso # 150”: a solvent manufactured by Exxon Chemical Co., Ltd.), xylene (Wako Pure Chemical Industries, Ltd.) (Reagent manufactured) was charged with 60.0 g, the inside was purged with nitrogen, the temperature was raised to 120 ° C., and (meth) acrylic monomer and 8.0 g of benzoyl peroxide described below were added dropwise over 2 hours, followed by stirring reaction I let you. After completion of the dropping, the reaction was further continued at 120 ° C. for 4 hours to obtain a main component polyol composition.
(Meth) acrylic monomer methyl methacrylate 128.8g used as raw material
n-Butyl acrylate 84.8g
Cyclohexane methacrylate 80.0g
74.4 g of 2-hydroxyethyl methacrylate
Styrene 32.0g
The obtained main component polyol composition had a solid content of 70%, a hydroxyl value = 80.0 mgKOH / g (based on the resin content), Tg = 40.1 ° C., and a number average molecular weight of 1700. The obtained main component polyol composition is hereinafter referred to as S-1.

“Synthesis Example 10”
Non-aqueous dispersion type acrylic polyol (trade name: Hitaroid 6500, manufactured by Hitachi Chemical Co., Ltd., hydroxyl value = 30 mg KOH / g (solid content), Tg = 33 ° C., heating residue = 53%, solvent composition = mineral turpen / solvesso 100 = 44/7) and low polar organic solvent soluble acrylic polyol (trade name: Hitaroid 6500B, manufactured by Hitachi Chemical Co., Ltd., hydroxyl value = 30 mg KOH / g (solid content), Tg = 35 ° C., heating residue = 53 mass%, solvent composition = mineral terpenes) was mixed at 9/1. The obtained main component polyol composition is hereinafter referred to as S-2.

The present invention will be described based on examples.
[Examples 1-8, Comparative Examples 1-4]
A two-component polyurethane composition was prepared as follows.
Curing agent polyisocyanate composition Px-1, Px using polyisocyanate compounds P-1, P-2, P-3, P-4, M-1, M-4, and a low polar organic solvent, silicate compound -2, Px-3, Px-4, Mx-1, and Mx-4 were obtained. Moreover, 1000 ppm of HALS (trade name “Sanol LS-765”: an additive manufactured by Sankyo Co., Ltd.) as an additive was added to the curing agent polyisocyanate compositions Px-3 to Px-4. . Table 2 shows the obtained curing agent polyisocyanate composition.
Table 2 shows the states of the obtained curing agent polyisocyanate compositions Px-1, Px-2, Px-3, Px-4, Mx-1, and Mx-4 at 20 ° C and 5 ° C. It was confirmed that the curing agent polyisocyanate of the present invention had good compatibility with the silicate and the low polarity organic solvent even at 20 ° C and 5 ° C.

In Examples 1-8, S-1 and S-2 were used as the main component polyol composition, and Px-1, Px-2, Px-3, and Px-4 were used as the curing agent polyisocyanate composition. 4, S-1 and S-2 are used as the main component polyol composition, and Mx-1 and Mx-4 are used as the curing agent polyisocyanate composition, respectively. In Examples 1 to 8 and Comparative Examples 1 to 4, the molar ratio of isocyanate group / hydroxyl group was adjusted to 1/1, and the solid content was adjusted to 50% using HAWS as a solvent. .
As an index of curability (crosslinkability), the gel fraction at the initial curing stage of the coating film was measured. If the curability is good, a tough coating film is formed, and chemical resistance and wear resistance are good. The gel fraction was measured when it was applied to a polypropylene plate with a bar coder so that the film thickness was about 50 microns and then dried at 20 ° C. for one day. The results are shown in Table 3. In Table 3, a gel fraction of 40% or more is represented by ◎, 20% or more and less than 30% is represented by ◯, and less than 20% is represented by ×.

As an index of stain resistance, the rain stripe contamination of the coating film was measured. With a bar coder, it was applied on a 100 mm x 225 mm alumite plate to a dry film thickness of 100 microns, dried for 1 week under 20 ° C and 65% RH conditions, and at 1/3 of the long side, It was bent to an inner angle of 135 ° C., the surface with a large area was made vertical, fixed in the north direction in Kawasaki City, Kanagawa Prefecture, and rain stripe contamination was visually determined about 3 months after the start of actual exposure. The results are shown in Table 3. In Table 3, the determination of rain stripe contamination is as follows.
A: No rain streaks are seen and the whole is not dirty.
○: Although it is dirty as a whole, no rain streak is seen.
X: Some dirt is seen on the whole, and rain stripes are also recognized.

As an indicator of chemical resistance, a test was conducted in which the two-component polyurethane composition produced in this case was immersed in 10% hydrochloric acid at 20 ° C. for 24 hours. As a result, it was confirmed that the two-component polyurethane composition produced in the present case did not change after the test and the chemical resistance was good.
As an indicator of weather resistance, measurement with S-WOM (Sunshine Weather Meter S80: tester manufactured by Suga Test Instruments Co., Ltd.) was performed. After applying to a white-coated aluminum plate with a bar coder so that the film thickness was about 50 microns, it was dried at 20 ° C. for 14 days, and the coating film was measured by S-WOM. As a result, even if the two-component polyurethane composition produced in this case exceeds 3000 hours, the gloss retention (digital declination gloss meter UGB-5D: measured using a tester manufactured by Suga Test Instruments Co., Ltd.) It was 85% or more. From this result, it was confirmed that the two-component polyurethane composition invented in the present case has good weather resistance.

A scratch resistance test of the coating film was performed as an index of wear resistance. A bar coder was applied to a white-coated aluminum plate so as to have a film thickness of 50 microns, followed by drying at 20 ° C. for 14 days. The two-component polyurethane composition produced in this case had a gloss retention of 70% or more before and after the scratch resistance test. From this result, it was confirmed that the two-component polyurethane composition invented in the present case has good wear resistance.
The two-component polyurethane composition of the present invention is obtained from at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate, and a monoalcohol having 1 to 20 carbon atoms, and has a molar ratio of allophanate group / isocyanurate group. A curing agent polyisocyanate composition containing a polyisocyanate compound having a ratio of 90/10 to 70/30 and a main component polyol composition containing an acrylic polyol, a polyester polyol or a polyether polyol as essential components are obtained. The film is characterized by having a good appearance, excellent weather resistance, and excellent scratch resistance.

In addition, the two-component polyurethane composition of the present invention used either or both of a curing agent polyisocyanate composition that dissolves in a low polarity organic solvent and a main component polyol composition that dissolves in a low polarity organic solvent. In this case, the low-polar organic solvent has a low dissolving power, so that it is difficult to attack the base. That is, when the two-component polyurethane composition of the present invention is applied directly without removing the old coating film or applying a sealing agent during the repainting operation, lifting is less likely to occur. In addition, when performing repair work and overcoating work, it is possible to perform overcoating without affecting the underlying coating film. Furthermore, the low polar organic solvent often has a property of low odor, and has a feature that it is difficult to cause odor to a painter or a nearby person.
Further, the polyisocyanate compound contained in the curing agent polyisocyanate composition of the present invention also has a characteristic of very low viscosity, and when it is a two-component polyurethane composition, it is possible to reduce the VOC component. Become.
Furthermore, the two-component polyurethane composition of the present invention has a feature that it has excellent rain-stain stain resistance because the coating surface becomes hydrophilic after coating and drying.

  The two-component polyurethane composition of the present invention can be used for paints, inks, adhesives, casting materials, elastomers, foams, and plastic materials. Especially suitable for architectural paints, heavy anticorrosion paints, automotive paints, home appliance paints, information equipment paints such as personal computers and mobile phones, where contamination resistance, weather resistance, chemical resistance, and abrasion resistance are required. Yes. Especially, it is suitable for the paint for construction, and the paint for heavy anti-corrosion, and can be suitably used especially in the field of architectural exterior paint for repainting applications.

Claims (6)

(A) It is obtained from at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate, and monoalcohol having 1 to 20 carbon atoms, and the molar ratio of allophanate group / isocyanurate group is 90/10 to 70 /. Curing agent polyisocyanate containing at least one silicate compound selected from polyisocyanate compound 30 and tetraalkoxysilane represented by the following formula (1), a condensate of tetraalkoxysilane, and a derivative of tetraalkoxysilane The main component polyol composition containing at least one of the composition and (B) acrylic polyol, polyester polyol, and polyether polyol is an essential component, and the isocyanate group and water of the main component polyol composition and the curing agent polyisocyanate composition. acid Equivalent ratio of (NCO / OH ratio) is 0.2 to 5.0, the mass ratio of the polyisocyanate compound and silicate compound is 5/95 to 95/5, two-component polyurethane composition.

R in the formula is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group.   The two-component polyurethane composition according to claim 1, wherein the curing agent polyisocyanate composition contains a low polarity organic solvent having an aniline point of 10C to 70C.   The two-component polyurethane composition according to claim 1 or 2, wherein the main component polyol composition contains a low polarity organic solvent having an aniline point of 10 ° C to 70 ° C. The two-component polyurethane composition according to any one of claims 1 to 3 , wherein the monoalcohol has 4 to 9 carbon atoms. The two-component polyurethane composition according to claim 1, claim 2, claim 3, or claim 4, which is used for construction or for heavy anticorrosion. A building to which the two-component polyurethane composition according to claim 5 is applied.