JP5245741B2 - Polyisocyanate curing agent composition for fluorine-based polyol and two-component coating composition using the same - Google Patents

Description

  The present invention relates to a polyisocyanate curing agent composition for a fluorine-based polyol and a two-component coating composition using the same.

The two-component urethane paint that uses polyisocyanate as a component gives a coating film with excellent weather resistance and abrasion resistance, so it can be applied to outdoor substrates such as buildings and civil engineering structures, automobile repairs, and plastics. Used for painting.
Conventionally, as a paint that can provide a coating film particularly excellent in weather resistance, a paint using a fluorinated polyol as a main agent and a polyisocyanate as a curing agent has been proposed. This paint includes a fluorinated polyol and a polyisocyanate. There is a problem that the compatibility with is low.

In order to improve this compatibility, for example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 5-287240), a monoalcohol having 1 to 10 carbon atoms and a fat as a curing agent for a two-component fluorine-based coating composition A technique using an allophanate group-containing polyisocyanate obtained by reaction with a group organic polyisocyanate is disclosed.
By the way, in the two-pack type urethane-based paint, generally, a strong solvent such as an aromatic hydrocarbon solvent such as toluene or xylene, or an ester-based solvent such as butyl acetate from the high polarity of polyisocyanate, that is, A solvent having a strong dissolving power is used, and the paint of Patent Document 1 is no exception.

  However, since these strong solvents have strong odors, they tend to be avoided in recent years in terms of improving the working environment and reducing the burden on the global environment. Furthermore, when a new paint is applied over the old paint film and the paint is repaired or repainted, if the repair paint contains a strong solvent having a high dissolving power, the old paint film will swell or dissolve, There is a possibility that it may be necessary to repair the old paint film. As a result, problems such as enlargement and complication of painting work, increase in painting cost, and extension of construction period may occur.

Japanese Patent Laid-Open No. 5-287240

  The present invention has been made in view of the above circumstances, and is used for a fluorine-based polyol that is soluble in a low-polar organic solvent, has excellent compatibility with a fluorine-based polyol compound, and can provide a coating film having excellent hardness. It is an object of the present invention to provide a polyisocyanate curing agent composition and a two-component coating composition using the same.

  As a result of intensive studies to achieve the above object, the present inventor is obtained by reacting an aliphatic or alicyclic diisocyanate with a monoalcohol having a predetermined carbon number, and has a number average molecular weight of 500 to 1, The polyisocyanate composition containing a predetermined ratio of 000 components and having an allophanate group / isocyanurate group molar ratio in a predetermined range is excellent in solubility in a low-polar organic solvent, and the polyisocyanate composition The present invention was completed by finding that the strength of a coating film obtained from a paint containing a fluorine-based polyol was improved.

That is, the present invention
1. It is obtained by subjecting an aliphatic or alicyclic diisocyanate and a monoalcohol having 11 to 20 carbon atoms to an allophanatization reaction and an isocyanuration reaction simultaneously in the presence of a tin octylate catalyst , and having a number average molecular weight of 500 to 1,000. Polyisocyanate having an ingredient content of 35 to 80% by mass and containing allophanate groups and isocyanurate groups in an allophanate group / isocyanurate group = 65/35 to 40/60 (molar ratio), and aniline A polyisocyanate curing agent composition for a fluorine-based polyol, comprising a low-polar organic solvent having a point of 10 to 70 ° C. or a low-polar organic solvent having a mixed aniline point of 5 to 50 ° C.,
2. 1 polyisocyanate curing agent composition for fluorine-based polyol, wherein the polyisocyanate contains a urethane group of 0.5 mol% or less when the total molar amount of the allophanate group and isocyanurate group is 100;
3. 1 or 2 polyisocyanate curing agent composition for fluorine-based polyol, wherein the molar ratio of the allophanate group to the isocyanurate group is 60/40 to 40/60,
4). The polyisocyanate curing agent composition for a fluorine-based polyol according to any one of 1 to 3, wherein the content of the component having a number average molecular weight of 500 to 1,000 is 35 to 63.3% by mass,
5 . A two-component coating composition comprising the polyisocyanate curing agent composition for fluorine-based polyol according to any one of 1 to 4 and a fluorine-based polyol compound;
6). A method for producing a polyisocyanate in which an aliphatic or alicyclic diisocyanate and a monoalcohol having 11 to 20 carbon atoms are simultaneously subjected to an allophanatization reaction and an isocyanurate reaction in the presence of a tin octylate catalyst, The content of the component having a number average molecular weight of 500 to 1,000 is 35 to 80% by mass, and allophanate group and isocyanurate group are allophanate group / isocyanurate group = 65/35 to 40/60 (molar ratio). A process for producing a polyisocyanate, characterized in that
7. When the polyisocyanate has a total molar amount of the allophanate group and isocyanurate group of 100, the production method of 6 polyisocyanate containing 0.5 mol% or less urethane group,
8). A process for producing a polyisocyanate of 6 or 7, wherein the molar ratio of the allophanate group to the isocyanurate group is 60/40 to 40/60;
9. The method for producing a polyisocyanate according to any one of 6 to 8, wherein the content of the component having the number average molecular weight of 500 to 1,000 is 35 to 63.3 mass% .

The polyisocyanate curing agent composition of the present invention is excellent in solubility in a low-polar organic solvent (weak solvent) and has good compatibility with a fluorine-based polyol used in a two-component paint.
The coating film obtained from the two-component coating composition using this polyisocyanate curing agent composition has a high tensile strength and is tough.
In addition, since the two-component coating composition of the present invention is soluble in a low-polar organic solvent (weak solvent), it does not erode the base layer during overcoating, and thus has excellent recoatability. Yes.

Hereinafter, the present invention will be described in more detail.
The polyisocyanate curing agent composition for fluorine-based polyol according to the present invention is obtained by reacting an aliphatic or alicyclic diisocyanate with a monoalcohol having 11 to 20 carbon atoms, and has a number average molecular weight of 500 to 1,000. And a polyisocyanate containing an allophanate group and an isocyanurate group in an allophanate group / isocyanurate group = 80/20 to 40/60 (molar ratio), and an aniline point. Includes a low polar organic solvent having a temperature of 10 to 70 ° C. or a low polar organic solvent having a mixed aniline point of 5 to 50 ° C.

In the present invention, when the allophanate group / isocyanurate group (molar ratio) in the polyisocyanate is out of the above range, the solubility of the polyisocyanate in the low-polar organic solvent is lowered, and the curing agent composition is used. The physical properties of the coated film are reduced.
The allophanate group / isocyanurate group (molar ratio) is preferably 75/25 to 40/60, more preferably 65/35 to 40/60, and still more preferably 60/40 to 40/60.
Further, the content of the urethane group in the polyisocyanate is not particularly limited, but in the polyisocyanate of the present invention, when the total molar amount of allophanate group and isocyanurate group is 100, 0.7 mol % Is preferable, and 0.5 mol% or less is more preferable. Moreover, the lower limit is not particularly limited, but is preferably 0.1 mol% or more.
The molar ratio of each functional group can be calculated by ¹ H-NMR measurement.

Moreover, when there are too many components below the number average molecular weight 500 in polyisocyanate, the coating-film intensity | strength obtained using a polyisocyanate hardening | curing agent composition will fall. On the other hand, when there are too many components having a number average molecular weight exceeding 1,000, the viscosity of the curing agent becomes high, and the workability at the time of coating operation is lowered.
The ratio of components having a number average molecular weight of 500 to 1,000 is preferably 35 to 75% by mass, more preferably 40 to 70% by mass.
In addition, in the molecular weight distribution obtained by gel permeation chromatography (GPC) measurement, this component ratio is the peak area (with a molecular weight of 500 to 1,000 when the peak area of the entire molecular weight distribution is 100%) %).

As said polyisocyanate, what made the allophanate of an aliphatic or alicyclic diisocyanate and a C1-C20 monoalcohol, and / or the thing made these are isocyanurate can be used.
In this case, the aliphatic or alicyclic diisocyanate can be appropriately selected from conventionally known ones. For example, hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methylpentane-1,5- Aliphatic diisocyanates such as diisocyanate and lysine diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylene diisocyanate Can be used. These diisocyanates may be used alone or in combination of two or more.
Of these, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and norbornane diisocyanate are particularly preferred in consideration of further improving the weather resistance of the resulting coating film.

On the other hand, specific examples of the monoalcohol having 11 to 20 carbon atoms include isotridecanol, 1-undecanol, 1-dodecanol, 1-eicosanol, 1-heptadecanol, 1-nonadecanol, 1-tridecanol, 1-tetra Decanol, 1-pentadecanol, stearyl alcohol, isostearyl alcohol, 3-ethyl-4,5,6-trimethyloctanol, 4,5,6,7-tetramethylnonanol, 4,5,8-trimethyldecane Examples thereof include 4,7,8-trimethyldecanol, 2-hexyl decanol, 2-octyl decanol, 2-dodecyl decanol, and 2-hexadecyl octadecanol.
Among these, in consideration of further increasing the solubility of the resulting polyisocyanate in a low-polar organic solvent, 1-tridecanol, isotridecanol, 1-dodecanol, 1-eicosanol, 1-heptadecanol, 1-nonadecanol 1-tetradecanol, 1-pentadecanol, stearyl alcohol and isostearyl alcohol are preferable, and 1-tridecanol and isotridecanol are more preferable.

The allophanatization reaction can be performed by heating diisocyanate and monoalcohol as described above to about 50 to 150 ° C. in the presence or absence of an organic solvent.
Allophanatization may be performed simultaneously with urethanization or after urethanization. When urethanization and allophanatization are performed simultaneously, the reaction may be performed in the presence of an allophanatization catalyst. When allophanatization is performed after urethanization, the urethanization reaction was performed for a predetermined time in the absence of the allophanatization catalyst. Thereafter, an allophanatization catalyst may be added to carry out the allophanatization reaction.

The allophanatization catalyst can be appropriately selected from known catalysts, and for example, a zirconium salt of a carboxylic acid can be used. Examples of the carboxylic acid include saturated aliphatic carboxylic acids such as acetic acid, propionic acid, butyric acid, caproic acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, 2-ethylhexanoic acid, cyclohexanecarboxylic acid, Saturated monocyclic carboxylic acids such as cyclopentanecarboxylic acid, saturated polycyclic carboxylic acids such as bicyclo (4.4.0) decane-2-carboxylic acid, mixtures of the above-mentioned carboxylic acids such as naphthenic acid, oleic acid, linoleic acid , Monocarboxylic acids such as unsaturated aliphatic carboxylic acids such as linolenic acid, soybean oil fatty acid and tall oil fatty acid, aromatic aliphatic carboxylic acids such as diphenylacetic acid, aromatic carboxylic acids such as benzoic acid and toluic acid; phthalic acid, Isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, gluta Acid, adipic acid, pimelic acid, suberic acid, kurtaconic acid, azelaic acid, sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, Examples thereof include polycarboxylic acids such as α, β-diethylsuccinic acid, maleic acid, fumaric acid, trimellitic acid and pyromellitic acid. These zirconium carboxylates can be used alone or in combination of two or more. In particular, it is more preferable to use a monocarboxylic acid zirconium salt having 10 or less carbon atoms such as zirconium octylate and zirconium 2-ethylhexanoate.
In addition, 0.0005-1 mass% is preferable with respect to the total mass of polyisocyanate and alcohol, and, as for the usage-amount of an allophanatization catalyst, 0.001-0.1 mass% is more preferable.

  When the reaction is performed in the presence of an organic solvent, various organic solvents that do not affect the reaction can be used. Specific examples thereof include aliphatic hydrocarbons such as n-hexane and octane; cyclohexane, methylcyclohexane, and the like. Alicyclic hydrocarbons; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate; ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, Glycol ether esters such as 3-methyl-3-methoxybutyl acetate and ethyl-3-ethoxypropionate; ethers such as diethyl ether, tetrahydrofuran and dioxane; methyl chloride, methylene chloride, chloroform and tetrasalt Carbon, methyl bromide, methylene iodide, halogenated hydrocarbons dichloroethane; N- methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, polar aprotic solvents such as hexamethylphosphoric phosphonyl amides. These solvents can be used alone or in combination of two or more.

After completion of the reaction, a reaction terminator such as phosphoric acid or phosphoric acid ester is added to the reaction system, and a termination reaction is performed at 30 to 100 ° C. for 1 to 2 hours to terminate the allophanate reaction.
After termination of the reaction, the desired allophanate-modified polyisocyanate can be obtained by removing unreacted components by a known method such as thin film distillation.
The obtained allophanate-modified polyisocyanate can be used as it is (when the above allophanate group / isocyanurate group is satisfied).

The allophanate-modified polyisocyanate obtained as described above mainly has an allophanate group, but a side reaction occurs due to, for example, a reaction under a condition in which an isocyanate group is excessively present, and an isocyanurate group is generated.
Therefore, the molar ratio of allophanate groups to isocyanurate groups in the resulting polyisocyanate is adjusted to about 80/20 to 40/60 by appropriately adjusting various conditions such as the ratio of [NCO] / [OH] in allophanate formation. It can adjust suitably in the range.

  On the other hand, examples of the isocyanuration reaction include a method of modifying (trimerization) polyisocyanate in the presence of an isocyanuration catalyst. As such a modification method, for example, methods described in Japanese Patent Nos. 3371480 and 2002-241458 can be used.

Examples of the isocyanurate-forming catalyst include metal salts of aliphatic carboxylic acids, phenolates such as potassium phenolate, 2,4,6-tris (dimethylaminomethyl) phenol, 2,4-bis (dimethylaminomethyl) phenol, Amine systems such as 2,6-di-t-butyl-4-dimethylaminotrimethylsilanephenol, triethylamine, N, N ′, N ″ -tris (dimethylaminopropyl) hexahydro-S-triazine, diazabicycloundecene Compounds can be used. Among these, tin salts, potassium salts, sodium salts, calcium salts, zinc salts, and bismuth salts of aliphatic carboxylic acids are preferable, and tin salts are particularly preferable because of easy reaction control.
Specifically, tin salts of acetic acid, propionic acid, undecylic acid, capric acid, octylic acid, and myristic acid can be preferably used.
In addition, 2-hydroxypropyltrimethylammonium octylate (DABCO TMR, manufactured by Sankyo Air Products Co., Ltd.) and potassium octylate (DABCO K-15, manufactured by Sankyo Air Products Co., Ltd.) may be used as commercially available products. it can.

The isocyanurate-modified polyisocyanate obtained as described above has an isocyanurate group, but also has an allophanate group by-produced during the reaction.
The molar ratio of the allophanate group and isocyanurate group in the obtained isocyanurate-modified polyisocyanate can be adjusted in the range of about 80/20 to 40/60 by appropriately adjusting the isocyanurate reaction time and the like.
In addition, the polyisocyanate previously converted to allophanate may be further isocyanurated to adjust the allophanate group / isocyanurate group molar ratio.

The polyisocyanate used in the present invention may be a blend of allophanate-modified polyisocyanate and isocyanurate-modified polyisocyanate.
In this case, allophanate-modified polyisocyanate and isocyanurate-modified polyisocyanate may be mixed at a ratio satisfying the above-described allophanate group / isocyanurate group molar ratio.
In addition, as long as the molar ratio of the allophanate group and isocyanurate group mentioned above is satisfy | filled as the whole mixture, the polyisocyanate which does not satisfy | fill the molar ratio of the said allophanate group and isocyanurate group can also be used partially.

  The viscosity of the polyisocyanate used in the present invention is not particularly limited, but is preferably 2,000 mPa · s or less at 25 ° C., more preferably 1,500 mPa · s or less, and 1,000 mPa. -More preferably, it is s or less. If the viscosity of the polyisocyanate exceeds 2,000 mPa · s, the viscosity of the coating composition may increase and it may be difficult to handle. On the other hand, the lower limit of the viscosity is not particularly limited, but is preferably 50 mPa · s or more, more preferably 100 mPa · s, and even more preferably 200 mPa · s from the viewpoint of handling.

Moreover, the polyisocyanate curing agent composition of the present invention contains a low polarity organic solvent having an aniline point of 10 to 70 ° C. or a low polarity organic solvent having a mixed aniline point of 5 to 50 ° C.
Here, the “aniline point” is a minimum temperature at which an equal volume of aniline and a sample (organic solvent) exist as a uniform mixed solution. The “mixed aniline point” is the lowest temperature at which 2 volumes of aniline, 1 volume of sample, and 1 volume of 1-heptane exist as a uniform mixed solution. The aniline point and mixed aniline point can be measured according to the aniline point and mixed aniline point test method described in JIS K 2256.
Since aniline has a freezing point of −6 ° C., the aniline point cannot be measured at temperatures below that. Therefore, a mixed aniline point is used in order to measure the solubility of the organic solvent over a wider area by mixing aniline with heptane.

  The aniline point is preferably 10 to 70 ° C, more preferably 10 to 65 ° C, and more preferably 10 to 50 ° C. Moreover, in the case of a mixed aniline point, 5-50 degreeC is preferable. When the aniline point is less than 10 ° C. or the mixed aniline point is less than 5 ° C., the base is likely to be attacked, and when the aniline point exceeds 70 ° C. or the mixed aniline point exceeds 50 ° C., it becomes difficult to dissolve the polyisocyanate.

  Examples of such organic solvents include methylcyclohexane (aniline point: 40 ° C.), ethylcyclohexane (aniline point: 44 ° C.), mineral spirit (aniline point: 56 ° C.), and turpentine oil (aniline point: 44 ° C.). Also, under the trade name marketed as petroleum-based hydrocarbons, High Aromatic White Spirit (hereinafter referred to as “HAWS”) (manufactured by Shell Chemicals Japan, aniline point: 17 ° C.), Low Aromatic White Spirit (hereinafter referred to as “Haromatic White Spirit”) , “LAWS”) (manufactured by Shell Chemicals Japan, aniline point: 44 ° C.), Essonaphtha No. 6 (ExxonMobil, aniline point: 43 ° C), Pegazole 3040 (ExxonMobil, aniline point: 55 ° C), A Solvent (manufactured by Nippon Oil Corporation, aniline point: 45 ° C), Clensol (Nippon Oil) Manufactured by the company, aniline point: 64 ° C.), mineral spirit A (manufactured by Nippon Oil Corporation, aniline point: 43 ° C.), Hyalom 2S (manufactured by Nippon Oil Corporation, aniline point: 44 ° C.), Solvesso 100 (manufactured by ExxonMobil Corporation) , Mixed aniline point: 14 ° C.), Solvesso 150 (manufactured by ExxonMobil, mixed aniline point: 18.3 ° C.), Swazol 100 (manufactured by Maruzen Petrochemical Co., Ltd., mixed aniline point: 24.6 ° C.), swazole 200 (Maruzen) Petrochemical Co., Ltd., mixed aniline point: 23.8 ° C), Swazol 1000 (Maruzen Petrochemical Co., Ltd., mixed aniline point: 12.7 ° C), Zol 1500 (Maruzen Petrochemical Co., Ltd., mixed aniline point: 16.5 ° C), Swazol 1800 (Maruzen Petrochemical Co., Ltd., mixed aniline point: 15.7 ° C), Idemitsu Ipsol 100 (Idemitsu Kosan Co., Ltd., mixed aniline point) : 13.5 ° C), Idemitsu Ipsol 150 (Idemitsu Kosan Co., Ltd., mixed aniline point: 15.2 ° C), Pegasol ARO-80 (ExxonMobil Corp., mixed aniline point: 25 ° C), Pegazole R-100 (Exxon) Mobil Corp., mixed aniline point: 14 ° C), Akiraishi Special Hyzol (manufactured by Shell Chemicals Japan, mixed aniline point: 12.6 ° C), Nisseki Hysol (manufactured by Nippon Oil Corporation, mixed aniline point: 17 ° C or less) ) And the like. These organic solvents can be used individually by 1 type or in mixture of 2 or more types.

An organic solvent having an aniline point of 70 ° C. or lower or a mixed aniline point of 50 ° C. or lower has a feature that it has less odor. Therefore, the coating composition of the present invention containing such a low-polar organic solvent is excellent from the viewpoint of environmental properties.
Furthermore, such a low-polarity organic solvent has a low dissolving power and does not easily attack the base, so that the coating composition can be repeatedly applied, and is suitable for repair coatings.

  The blending ratio of the polyisocyanate and the low polarity organic solvent in the polyisocyanate curing agent composition is not particularly limited, but in the present invention, polyisocyanate: low polarity organic solvent = 90: 10 to 10 by mass ratio. 10:90 is preferable and 80:20 to 20:80 is more preferable.

The coating composition of this invention contains the polyisocyanate hardening | curing agent composition mentioned above and a fluorine-type polyol.
In addition, it does not specifically limit as a fluorine-type polyol, Although it can select suitably from a conventionally well-known thing and can use it, the polyisocyanate hardening | curing agent composition of this invention that the solubility with respect to a low polar organic solvent is favorable. From the characteristics of the product, a fluorine-based polyol that is soluble in a low-polarity solvent is preferable.
The fluorine-based polyol soluble in such a low-polar organic solvent is not particularly limited, and a known weak solvent-soluble fluorine-based polyol can be used. Specific examples thereof include a fluoroethylene-vinyl ether (vinyl ester) copolymer. As a commercial item, Lumiflon LF800 (Asahi Glass Co., Ltd. product) etc. are mentioned.

Although the hydroxyl value and acid value of the fluorine-based polyol are not particularly limited, the hydroxyl value of the paint of the present invention is preferably 1 to 300 mgKOH / g, more preferably 1 to 250 mgKOH / g. When the hydroxyl value is less than 1 mg KOH / g, the coating film is insufficiently crosslinked, and the physical properties such as the coating film strength tend to decrease. When the hydroxyl value exceeds 300 mg KOH / g, the crosslinking density of the coating film becomes too high and hard. The followability and flexibility to the substrate may be reduced.
On the other hand, the acid value is preferably from 0.1 to 5 mgKOH / g, and more preferably from 0.5 to 3 mgKOH / g.
Further, the number average molecular weight of the fluorinated polyol is preferably 5,000 to 20,000, more preferably 7,000 to 15,000, considering the strength of the coating film to be obtained and the handleability of the paint. The number average molecular weight is a value measured by GPC (polystyrene conversion value) by differential refractometer detection.

  The blending ratio of the polyisocyanate curing agent composition and the fluorine-based polyol in the coating composition of the present invention is preferably 1 to 150 parts by mass of the polyisocyanate curing agent composition with respect to 100 parts by mass of the fluorine-based polyol. 1 to 130 parts by mass, and more preferably 1 to 100 parts by mass.

  In addition, the said coating composition may contain the low polar organic solvent mentioned above and the various additives generally used for a coating material. Examples of additives include plasticizers, antiseptics, antifungal agents, algaeproofing agents, antifoaming agents, leveling agents, pigment dispersants, anti-settling agents, anti-sagging agents, catalysts, curing accelerators, dehydrating agents, and gloss. Examples include an eraser, an ultraviolet absorber, an antioxidant, a pigment, and a surfactant.

When a coating film is produced from the coating composition of the present invention, brushing, roller coating, spraying is applied to an appropriate base material such as concrete, mortar, siding board, extrusion board, porcelain tile, metal, glass, wood, plastic, etc. It may be applied by a method such as dip coating, and dried and cured by an appropriate method.
Moreover, when coating a dry type building material, you may precoat in a factory etc. with a flow coater or a roll coater.
The coating composition may be applied directly to the substrate, or may be applied from above the sealing, electrodeposition, undercoating (primer coating), or intermediate coating (coloring, etc.). Moreover, when a base material is a metal, you may apply | coat after performing surface treatments, such as an iron phosphate process or a zinc phosphate process.

  EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. In the following, the viscosity is a value measured with a B-type rotational viscometer.

[1] Production of Modified Polyisocyanate [Synthesis Example 1] Synthesis of Modified Polyisocyanate S-1 Hexamethylene diisocyanate was added to a one-liter four-necked flask equipped with a stirrer, thermometer, cooling tube, and nitrogen gas introduction tube. 880 g (manufactured by Nippon Polyurethane Industry Co., Ltd., NCO content: 49.9% by mass, hereinafter referred to as HDI) and 120 g of tridecanol were charged, and these were heated to 85 ° C. with stirring, and subjected to a urethanization reaction for 3 hours.
Thereafter, 0.1 g of tin octylate (manufactured by Nippon Chemical Industry Co., Ltd.), which is an isocyanurate-forming catalyst, was added to the reaction solution and reacted at 110 ° C. 0.2 g of acidic phosphate ester (JP-508, manufactured by Johoku Chemical Industry Co., Ltd.) as an agent was added, and a stop reaction was performed at 50 ° C. for 1 hour.
Excess HDI was removed from the reaction product by thin-film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 15.8% by mass, viscosity (25 ° C.) 320 mPa · s, free HDI content 0.1 Mass% modified polyisocyanate S-1 was obtained.

[Synthesis Examples 2-5] Synthesis of Modified Polyisocyanates S-2 to S-5 Modified Polyisocyanates S-2 to S-5 were obtained in the same manner as in Synthesis Example 1 except that the amounts were changed to the amounts shown in Table 1. It was.

[Comparative Synthesis Example 1] Synthesis of Modified Polyisocyanate S-7 880 g of HDI and 120 g of tridecanol were charged into a one-liter four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube. While stirring, the mixture was heated to 85 ° C. and subjected to urethanization reaction for 3 hours.
Thereafter, 0.1 g of zirconium octylate (Daiichi Rare Element Chemical Co., Ltd.) as an allophanatization catalyst was added to this reaction solution and reacted at 110 ° C., and when a predetermined NCO content was reached. 0.2 g of acidic phosphate ester (JP-508, manufactured by Johoku Chemical Industry Co., Ltd.) which is a reaction terminator was added, and a termination reaction was performed at 50 ° C. for 1 hour.
Excess HDI was removed from this reaction product by thin-film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 14.8% by mass, viscosity (25 ° C.) 150 mPa · s, free HDI content 0.1 Mass% modified polyisocyanate S-7 was obtained.

[Comparative Synthesis Example 2] Synthesis of Modified Polyisocyanate S-9 The modified polyisocyanate obtained in Synthesis Example 1 was added to a one-liter four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube. 140 g of S-1 and 60 g of polyisocyanate S-7 obtained in Comparative Synthesis Example 1 were charged and stirred for 1 hour, modified polyisocyanate having an NCO content of 15.5% by mass and a viscosity (25 ° C.) of 270 mPa · s. S-9 was obtained.

[Comparative Synthesis Example 3] Synthesis of Modified Polyisocyanate S-6 Modified polyisocyanate S-6 was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to the amount shown in Table 1.

[Synthesis Example 6] Synthesis of Modified Polyisocyanurate S-10 The modified polyisocyanate obtained in Synthesis Example 4 was added to a one-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube, and a nitrogen gas introduction tube. 100 g of S-4 and 100 g of polyisocyanate S-6 obtained in Comparative Synthesis Example 3 were charged and stirred for 1 hour, and modified polyisocyanate having an NCO content of 16.5% by mass and a viscosity (25 ° C.) of 1580 mPa · s. S-10 was obtained.

Comparative Synthesis Example 4 Synthesis of Modified Polyisocyanate S-8 910 g of HDI and 90 g of 2-ethylhexanol were charged into a 1-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube, and a nitrogen gas introduction tube. Immediately after heating to 80 ° C., a urethanization reaction was carried out for 2 hours.
Thereafter, 0.5 g of tin octylate (manufactured by Nippon Chemical Industry Co., Ltd.), which is an isocyanurate-forming catalyst, was added to the reaction solution and reacted at 110 ° C. When the predetermined NCO content was reached. 1.0 g of acidic phosphate ester (JP-508, manufactured by Johoku Chemical Industry Co., Ltd.) as a stopping agent was added, and a stopping reaction was performed at 50 ° C. for 1 hour.
Excess HDI was removed from this reaction product by thin-film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.1% by mass, viscosity (25 ° C.) 700 mPa · s, free HDI content 0.2 Mass% modified polyisocyanate S-8 was obtained.

For the modified polyisocyanates S-1 to S-10 obtained in the above synthesis examples and comparative synthesis examples, the (formation) molar ratio of allophanate group, isocyanurate group and urethane group, and the number average molecular weight of 500 to 1,000, respectively. The content ratio of the components was measured by the following method. The results are shown in Table 1.
[Measurement method]
[1] (Production) molar ratio of allophanate group, isocyanurate group and urethane group
^{Using 1} H-NMR (300 MHz, manufactured by Varian), the signal of the hydrogen atom bonded to the nitrogen atom of the allophanate group near 8.5 ppm and the methylene group adjacent to the nitrogen atom of the isocyanurate group near 3.7 ppm It calculated | required from the area ratio of the signal of a hydrogen atom, and the signal of the hydrogen atom couple | bonded with the nitrogen atom of the urethane group of 7.0 ppm vicinity. Specific measurement conditions are as follows.
Measurement temperature: 23 ° C
Sample concentration: 0.02 g / 1 ml
Integration count: 32 times Relaxation time: 5 seconds
Solvent: Deuterium dimethyl sulfoxide Chemical shift criteria: Signal of hydrogen atom of methyl group in deuterium dimethyl sulfoxide (2.5 ppm)

[2] Content ratio of components having a number average molecular weight of 500 to 1,000 In the molecular weight distribution obtained by the following measurement, when the peak area of the entire molecular weight distribution is 100%, the molecular weight calculated from the following conditions is 500 to 500 The peak area (%) of 1,000 was determined and used as the content ratio of components having a number average molecular weight of 500 to 1,000.
[Measurement method]
GPC device: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSKgel G3000H _XL , G2500H _XL , G2000H _XL , G1000H _XL
Temperature: 40 ° C
Detector: RI (refractive index) detector Eluent: THF (tetrahydrofuran)
Flow rate: 1,000 ml / min
Calibration curve: Standard polystyrene (manufactured by Tosoh Corporation)
F-80 (TS-201) (7.06 × 10 ⁵ )
F-20 (TS-141) (1.90 × 10 ⁵ )
F-10 (TS-144) (9.64 × 10 ⁴ )
F-2 (TS-504) (1.80 × 10 ⁴ )
F-1 (TS-508) (1.02 × 10 ⁴ )
A-5000 (TS-503) (5.97 × 10 ³ )
A-2800 (TS-502) (2.63 × 10 ³ )
A-500 (TS-505) (5.0 × 10 ² )
HDI monomer molecular weight 168
C-HXLV
Trimer molecular weight 505
Pentamer molecular weight 841
7-mer molecular weight 1177
Sample concentration: 0.5% by mass (THF solution)

Furthermore, about polyisocyanate S-1 to S-10, the solubility in 20 degreeC with respect to the mineral spirit A (made by Nippon Oil Corporation) was measured with the following method. The results are also shown in Table 1.
[Measurement method]
1 g of polyisocyanate was weighed out, and mineral spirit A was added thereto. The turbid portion was taken as the end point, and the amount (g) of mineral spirit A added at that time was determined.
Using this added amount, tolerance was calculated from the following formula (1).
Tolerance = Required amount of organic solvent (g) / Sample amount (1 g) (1)

[2] Production of polyisocyanate curing agent composition and two-component coating composition [Examples 1 to 5, Reference Example 1 and Comparative Examples 1 to 4]
Each polyisocyanate and mineral spirit A (manufactured by Shin Nippon Oil Co., Ltd.) obtained in the above synthesis examples and comparative synthesis examples were blended in the proportions shown in Table 2 to prepare polyisocyanate curing agent compositions.
Furthermore, the obtained polyisocyanate curing agent composition, fluorine polyol (Lumiflon LF800, manufactured by Asahi Glass Urethane Co., Ltd.), titanium oxide (CR-90, manufactured by Ishihara Sangyo Co., Ltd.), and mineral spirit A (Shin Nippon Oil ( Co., Ltd.) was blended in the proportions shown in Table 3 to prepare a two-component coating composition.

Steel plates obtained by degreasing the two-component coating compositions prepared in Examples 1 to 5, Reference Example 1 and Comparative Examples 1 and 2 with methyl ethyl ketone (JIS G3141 trade names: SPCC-SB, PF-1077 treatment, Japan Test Panel) (Applicable to Kogyo Co., Ltd.) Using an applicator, the film was applied with a wet film thickness of 100 μm and cured for 7 days in an environment of 20 ° C. and a relative humidity of 65% to form a coating film having a dry film thickness of 40 to 50 μm. About the obtained coating film, the following each characteristic was evaluated. The results are shown in Table 4.
In addition, about the comparative examples 3 and 4, since the solubility with respect to the mineral spirit A of modified polyisocyanate S-6 and S-8 was bad, the coating-film test was not implemented.

(1) Bending resistance Using a cylindrical mandrel with a diameter of 2 mm, the coating film cracked when it was bent by a cylindrical mandrel and the presence or absence of peeling from the steel plate, JIS K-5600-5-1: 1999 Evaluation was performed according to a flex resistance test. A film that did not cause cracking or peeling of the coating film was evaluated as acceptable (◯).
(2) Cupping resistance JIS K-5600-5-2: 1999 cupping resistance test using an indenter to check for cracks in the coating film when it was partially deformed by indentation, and whether or not it peeled off from the steel sheet. Evaluated in accordance with. The indentation depth (mm) at which the coating film was cracked or peeled off by the indenter was defined as cupping resistance.
(3) Weight drop resistance Using a weight of 10.3 mm in diameter and a weight of 0.5 kg, JIS K-5600 is used to determine whether the coating film is cracked or peeled off from the steel sheet when subjected to deformation due to weight drop. -5-3: Evaluated according to 1999 weight drop resistance test (DuPont method). The minimum drop height (cm) at which the coating film cracked and peeled was defined as the weight drop resistance.
(4) Coating film hardness The hardness of the coating film surface was measured based on the scratch hardness test (pencil method) of JIS K-5600-5-4: 1999. The hardness of the hardest pencil with no scratch marks on the surface of the coating film was defined as the coating film hardness.
(5) Adhesiveness The adhesiveness of the coating film is determined from the substrate when a cross-cut tape peeling test based on JIS K-5600-5-6: 1999, a right-angle lattice pattern is cut into the coating film and penetrates to the substrate. The coating film was evaluated for resistance to peeling (cross-cut method).

As shown in Table 4, it can be seen that the coating films obtained from the coating compositions of Examples 1 to 5 are excellent in adhesion and hardness.

Claims (9)

It is obtained by subjecting an aliphatic or alicyclic diisocyanate and a monoalcohol having 11 to 20 carbon atoms to an allophanatization reaction and an isocyanuration reaction simultaneously in the presence of a tin octylate catalyst , and having a number average molecular weight of 500 to 1,000. A polyisocyanate having a component content of 35 to 80% by mass and containing an allophanate group and an isocyanurate group in an allophanate group / isocyanurate group = 65/35 to 40/60 (molar ratio), and aniline A polyisocyanate curing agent composition for a fluorine-based polyol, comprising a low-polar organic solvent having a point of 10 to 70 ° C or a low-polar organic solvent having a mixed aniline point of 5 to 50 ° C.   2. The polyisocyanate curing agent composition for fluorine-based polyol according to claim 1, wherein the polyisocyanate contains 0.5 mol% or less of urethane groups when the total molar amount of the allophanate groups and isocyanurate groups is 100. 3. The polyisocyanate curing agent composition for fluorine-based polyol according to claim 1 or 2, wherein the molar ratio of the allophanate group to the isocyanurate group is 60/40 to 40/60. The polyisocyanate curing agent composition for fluorine-based polyol according to any one of claims 1 to 3, wherein the content of the component having a number average molecular weight of 500 to 1,000 is 35 to 63.3 mass%. A two-component coating composition comprising the polyisocyanate curing agent composition for a fluorine-based polyol according to any one of claims 1 to 4 and a fluorine-based polyol compound. A process for producing a polyisocyanate, in which an aliphatic or alicyclic diisocyanate and a monoalcohol having 11 to 20 carbon atoms are simultaneously reacted in the presence of a tin octylate catalyst and allophanated and isocyanurated,
The content of the component having a number average molecular weight of 500 to 1,000 in the polyisocyanate is 35 to 80% by mass, and allophanate group and isocyanurate group are allophanate group / isocyanurate group = 65/35 to 40 / It contains by 60 (molar ratio), The manufacturing method of the polyisocyanate characterized by the above-mentioned. The method for producing a polyisocyanate according to claim 6, wherein the polyisocyanate contains 0.5 mol% or less of a urethane group when the total molar amount of the allophanate group and the isocyanurate group is 100. The method for producing a polyisocyanate according to claim 6 or 7, wherein a molar ratio between the allophanate group and the isocyanurate group is 60/40 to 40/60. The method for producing a polyisocyanate according to any one of claims 6 to 8, wherein a content of the component having a number average molecular weight of 500 to 1,000 is 35 to 63.3 mass%.