JPH09194564A - Urethane composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a urethane composition, consisting essentially of a polyisocyanate having at least one isocyanate group bonded to a hindered amine- based compound, capable of providing a coating film excellent in long-term weather resistance and useful as an adhesive, etc. SOLUTION: This urethane composition consists essentially of a polyisocyanate having at least one isocyanate group bonded to a hindered amine- based compound. The hindered amine-based compound preferably has amino group having active hydrogen or hydroxyl group. Reactional products, etc., of various polyols with an isocyanate compound are preferred as the polyisocyanate. The content of the hindered amine-based compound is preferably 0.01-10wt.% based on the whole polyisocyanate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a urethane composition suitable for paints, adhesives, sealants and the like.

[0002]

2. Description of the Related Art Conventionally, urethane resins have been used in a wide range of applications such as paints, adhesives and sealants mainly in the construction field because of their excellent wear resistance, chemical resistance and stain resistance. However, particularly in the case of paints, a large amount of cost is required for repainting due to soaring labor costs and the like, so that a maintenance-free paint having good weather resistance has been demanded. In order to solve this, many antioxidants, UV absorbers,
Although light stabilizers and the like have been developed and used, these low molecular weight additives have the drawback that after coating, they exude from the coating film and are washed away by rain or the like. In order to solve this drawback, high molecular weight compounds of these additives have been developed, but their compatibility with urethane resins was poor and there were many practical problems.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide urethane compositions such as paints, adhesives and sealants which have excellent weather resistance for a long period of time.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have made polyisocyanate in which at least one isocyanate group of polyisocyanate is bonded to a hindered amine compound an essential component. The cured product obtained from the urethane composition was found to have excellent weather resistance over a long period of time, and the present invention has been completed.

That is, the present invention is characterized in that it is a urethane composition containing as an essential component a polyisocyanate in which at least one isocyanate group is bonded to a hindered amine compound.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyisocyanate of the present invention is
It is a compound having at least one isocyanate group, and is preferably a reaction product of various polyols and an isocyanate compound, and / or a condensate or polymer of a low molecular weight polyisocyanate.

As these isocyanate compounds,
For example, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate (or 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate) and other aliphatic or cycloaliphatic diisocyanates, tolylene diisocyanate (various mixtures of isomers Examples of aromatic diisocyanates and triisocyanates such as (including) and diphenylmethane diisocyanate (including various mixtures of isomers) include lysine triisocyanate. Furthermore, as a condensate or polymer of these monomers, 3
Various modified polyisocyanates such as isocyanurate type polyisocyanates having a functionality or higher, burette type polyisocyanates, and polymethylene polyphenyl polyisocyanates (for example, Millionate MR manufactured by Nippon Polyurethane Industry Co., Ltd.) can be mentioned.

Examples of various polyols which form a reaction product of an isocyanate compound include polyester polyols, polyether polyols, polycarbonate polyols, silicone polyols, acrylic polyols and polyolefin polyols.

As the polyester polyol, for example, a dibasic acid selected from the group of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid and terephthalic acid, alone or Polyester obtained by a condensation reaction of a mixture with a polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin, etc., alone or in a mixture, and, for example, ε-caprolactone Examples thereof include polycaprolactone obtained by ring-opening polymerization using a polyhydric alcohol.

As the polyether polyol, for example, a polyol obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide alone or a mixture to a polyhydric alcohol such as glycerin or propylene glycol, or polytetramethylene glycol. And so on.

Polycarbonate polyols include aromatic polyhydric alcohols such as bisphenol A and 1,6-
Examples thereof include those obtained by a conventional method using an aliphatic or alicyclic polyhydric alcohol such as hexanediol as a raw material.

Examples of silicone polyols include polydimethylsiloxane.

Examples of acrylic polyols include:
Acrylic acid-2-hydroxyethyl, acrylic acid-2-
Acrylic esters with active hydrogen such as hydroxypropyl and 2-hydroxybutyl acrylate, methacryl with active hydrogen such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate and 2-hydroxybutyl methacrylate Acid ester, or a single or mixture selected from the group consisting of acrylic acid methacrylic acid monoester of glycerin or methacrylic acid monoester, acrylic acid monoester of trimethylolpropane or methacrylic acid monoester, and methyl acrylate, ethyl acrylate, acrylic acid Isopropyl ester, acrylic acid ester such as n-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, methacrylic ester ester such as methacrylic acid-n-butyl, acrylic acid Unsaturated carboxylic acids such as methacrylic acid, maleic acid, itaconic acid, acrylamide, N-methylol acrylamide, glycidyl methacrylate, styrene, vinyl acetate, and those obtained by copolymerizing with a mixture of polymerizable monomers such as acrylonitrile. Can be mentioned.

Examples of the polyolefin polyol include polybutadiene and hydrogenated polybutadiene.

The molecular weight of the polyol used in the present invention is usually 300 to 50,000, preferably 4
00-10,000, more preferably 500-7,
When the molecular weight is too low, it tends to be difficult to form a durable coating film, and when the molecular weight is too high, application tends to be difficult.

The polyisocyanate obtained by binding the hindered amine compound of the present invention is usually used as a mixture with another polyisocyanate. The mixing ratio of the polyisocyanate of the present invention, as a hindered amine compound, is usually 0.01 to 10% by weight, preferably 0.05 to 5% by weight of the polyisocyanate mixture.

The hindered amine compound of the present invention is an amino compound having a bulky substituent at an adjacent carbon atom, and is preferably 3,3,5,5-tetramethylpiperidinol or bis (2). , 2,6,6-Tetramethyl-4-piperidine) sebacate and other hindered amine compounds having an amino group having active hydrogen, for example, 1,3,3,5,5-pentamethyl-4-piperidinol and other hydroxyl groups. Examples thereof include hindered amine compounds, but are not limited thereto.

The hindered amine compound of the present invention has a polyisocyanate and active hydrogen of the hindered amine compound, preferably an amino group and / or a hydroxyl group of the hindered amine compound, bonded to an isocyanate group of the polyisocyanate. Further, the thiol group and / or the carboxyl group may be bonded to the isocyanate group of the polyisocyanate. The urethane composition of the present invention can be produced from a polyisocyanate and a hindered amine compound containing active hydrogen, and is preferably produced by previously reacting the hindered amine compound and the isocyanate group of the polyisocyanate.

In the method for producing the urethane composition of the present invention, an organic solvent may or may not be used, but when an organic solvent is used, a polyisocyanate and a hindered amine compound are dissolved and no active hydrogen is contained. Can be used, for example, aromatic hydrocarbons such as xylene and toluene, 2-butanone, 4-methyl-2-pentanone, 2-
Examples thereof include ketones such as heptanone.
In the production method of the present invention, a catalyst can be used if necessary. As the catalyst, a usual urethane catalyst can be used. Other known metal compound catalysts such as tin compounds can be mentioned. If the amount of the catalyst is too large, it tends to cause coloring, and if it is too small, the catalytic effect tends to be insufficient. Therefore, the amount of the catalyst is usually 0.005-1% by weight, preferably 0.01-.
It is selected in the range of 0.8% by weight. The temperature in the production method of the present invention is 0 to 150 ° C, preferably 10 to 120 ° C.
Is selected in the range.

The urethane composition of the present invention may be either one-component curing type or two-component curing type. If it is a one-component type, only a mixture of polyisocyanate is used as a resin component, and if it is a two-component type, a polyol component and a polyisocyanate mixture may be mixed at the time of use.

The urethane composition of the present invention may contain various additives and fillers as in the case of ordinary paints. Examples thereof include pigments, defoamers, defoamers, thickeners, dehydrators, surface conditioners, ultraviolet absorbers, antioxidants, curing catalysts and the like.

[0022]

EXAMPLES Examples will be described below, but the invention is not limited thereto.

Example 1 Polycaprolactone-based urethane prepolymer (Huls
VESTICOAT UT880, NCO content 5.5% by weight) 100 parts by weight solution of 100 parts by weight and dibutyltin dilaurate 0.1 parts by weight in a four-necked flask equipped with a stirrer, a reflux tube, a thermometer, and a dropping funnel. It was dissolved in 100 parts by weight of dry xylene. As a hindered amine compound, a solution prepared by dissolving 10 parts by weight of 1,3,3,5,5-pentamethyl-4-piperidinol (manufactured by Mitsui Petrochemical Co., Ltd.) in 20 parts by weight of dry xylene was added dropwise at 70 ° C.
Stir for 4 hours. 10 parts by weight of the obtained urethane polymer solution, 95 parts by weight of VESTICOAT UT880,
Polycaprolactone-based urethane prepolymer (Huls
Manufactured by VESTICOAT UT647, NCO content of 3.5% by weight) 44% by weight of a 70% by weight solution and 52 parts by weight of dry xylene were mixed well, and a polished steel test plate (SPCC-SB, 150 ×) was obtained. 70 × 0.8 mm) with a brush and cured. Sunshine weather o-meter (Suga testing machine), 60 ° after 300 hours
The specular gloss and the color difference ΔE were measured.

Comparative Example 1 Polycaprolactone-based urethane prepolymer (Huls
100 parts by weight of VESTICOAT UT880, a polycaprolactone-based urethane prepolymer (Hu
44 parts by weight of VESTICOAT UT647 manufactured by Is Co., Ltd., and TINUVIN as a hindered amine compound.
765 (Ciba Geigy, main component: bis (1, 2, 2,
0.6 parts by weight of 6,6-pentamethyl-4-piperidinyl) sebacate) and 58 parts by weight of dry xylene were thoroughly mixed, applied to a test plate and cured.

As shown in Table 1, the coating film using the urethane composition of the present invention has a higher gloss retention rate than the coating film to which the hindered amine compound which is a light stabilizer for urethane is simply added. It can be seen that the color difference is small.

[0026]

[Table 1]

[0027]

EFFECT OF THE INVENTION A urethane composition containing a polyisocyanate formed by combining with a hindered amine compound of the present invention as an essential component gives a urethane resin coating film excellent in weather resistance for a long period of time and is used as an adhesive or a sealing material. Can also be preferably used.

Claims (10)

[Claims] 1. At least one isocyanate group is
A urethane composition comprising a polyisocyanate formed by binding with a hindered amine compound as an essential component. 2. The urethane composition according to claim 1, wherein the hindered amine compound has an amino group having active hydrogen. 3. The urethane composition according to claim 1, wherein the hindered amine compound has a hydroxyl group. 4. The urethane composition according to claim 1, wherein the amino group of the hindered amine compound is bonded to an isocyanate group. 5. The urethane composition according to claim 1, wherein a hydroxyl group of the hindered amine compound is bonded to an isocyanate group. 6. The method according to claim 1, wherein the polyisocyanate is a reaction product of a polyol selected from polyester polyol, polyether polyol, polycarbonate polyol, silicone polyol, acrylic polyol, and polyolefin polyol, and an isocyanate compound. The urethane composition described. 7. The urethane composition according to claim 1, wherein the polyisocyanate is a condensate or polymer of a low molecular weight polyisocyanate. 8. The urethane composition according to claim 1, wherein the polyisocyanate formed by combining with a hindered amine compound is used as a mixture with another polyisocyanate. 9. The content of the hindered amine compound is
The urethane composition according to claim 1, which is 0.01 to 10% by weight of the total polyisocyanate. 10. A method for producing a urethane composition, which comprises reacting a hindered amine compound with an isocyanate group of a polyisocyanate in advance.