JPH02105880A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition improved in weathering resistance without detriment to the features of Japanese lacquer by using a mixture of a hydrogenated polybutadiene polyol with Japanese lacquer as a first pack and using a polyisocyanate as a second pack. CONSTITUTION:A two-pack coating composition is formed by using a mixture formed by mixing a hydrogenated polybutadiene polyol (A), wherein the main chain comprises a homopolymer of butadiene or a copolymer of butadiene with a vinyl compound, at least 50% of the butadiene units are bonded through a 1,2-bond, the unsaturated bonds have been saturated by hydrogenation, it has at least one OH group in the molecule, and the hydroxyl value is 10-500 KOHmg/g, with Japanese lacquer (B) in a weight ratio: 100/5>=A/B>=100/100, desirably, 100/10>=A/B>=100/60 as a first pack, and using a polyisocyanate component as a second pack. The mixing ratio between the first and second packs is usually 1/0.9>=OH/NCO>=1/1.5, desirably, 1/0.9>=OH/NCO>=1.1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating composition, and more particularly to a polyurethane-based coating composition in which lacquer is blended with hydrogenated polybutadiene polyol and polyisocyanate. 8. The coating composition of the present invention not only maintains the durability and texture of lacquer, but also has excellent weather resistance, so it is expected to be used in a wide range of fields as a high-grade coating.

[Conventional technology]

Lacquer has been used as an ancient Japanese paint for a wide range of products, including lacquerware, Buddhist altars, furniture, and fittings, as well as shrines and temples, arts and crafts, and daily necessities.

Even today, lacquer is a representative of high-class lacquerware, enriching daily life, and now that the trend toward luxury has progressed, lacquer is once again attracting attention from various quarters.

In recent years, highly weather-resistant paints such as non-yellowing polyurethane resin paints, acrylic silicone resin paints, and fluororesin paints have been developed as high-grade paints.

On the other hand, despite having the above-mentioned features, lacquer has poor weather resistance, and in order to improve this drawback, modification through chemical reactions such as mixing with highly weather-resistant resins, acrylicization, siliconization, etc. is being considered. In particular, concentrated polyurethane resin paints in which polyisocyanate is added to a mixture of lacquer and polyol components have been actively studied (see Japanese Patent Publication No. 58-013100).

[Problem that the invention seeks to solve]

The highly weather-resistant paints cited above are not used in the field of high-grade painting, where lacquer is used, because they have poor durability and poor gloss compared to lacquer.

On the other hand, when mixing lacquer with a highly weather-resistant resin, there are extreme restrictions on resin selection due to compatibility between the lacquer and the highly weather-resistant resin, storage stability, etc., and chemical modification such as acrylicization and siliconization. However, this method has not been put into practical use at present because it hinders the drying properties of the lacquer.

It is considered to modify lacquer with urethane using polybutadiene polyol, which has excellent compatibility with lacquer, but when ordinary polybutadiene polyol is used, the double bonds remaining in the coating film may cause weather resistance to deteriorate. The expected results are not being obtained.

An object of the present invention is to provide a coating composition with improved weather resistance without impairing the characteristics of lacquer.

[Means for solving problems]

As a result of intensive research to achieve the above object, the present inventors have discovered that by using hydrogenated polybutadiene-based polyol, which does not have a double bond in its molecular chain, in place of polybutadiene-polyol as a coexisting component of lacquer. , discovered that the coating film of the urethane modified product has extremely excellent weather resistance,
The invention has been completed.

The present invention is a 1,2-butadiene-based polymer whose main chain is a butadiene homopolymer or a copolymer of butadiene and a vinyl compound, and in which 50% or more of the butadiene units are 1,2-bonds. A polyol consisting of a mixture of a hydrogenated polybutadiene polyol [component A] and lacquer [component B], which is saturated and has at least one hydroxyl group in the molecule and has a hydroxyl value of 10 to 500 KOHmg/H. This is a two-component coating composition having a first component and a polyisocyanate (component C) as a second component.

In the present invention, the hydrogenated polybutadiene polyol of component A includes the following.

! al Hydrogenated polybutadiene (poly)ols whose main chain is a hydride of 1,2-polybutadiene and which has at least one hydroxyl group in the molecule, such as Nl5S
OG! -1,000, same 2,000, same 3,00
0 (manufactured by Nippon Soda ■), (b) The main chain is butadiene and vinyl compounds, such as aliphatic vinyl compounds such as acrylic acid and methacrylic acid, aromatic vinyl compounds such as styrene, α-methylstyrene, and divinylbenzene. Hydrogenated butadiene-radically polymerizable compound copolymers and (poly)ols which are hydrogenated products of copolymers in which 50% or more of the butadiene units are 1,2-bonds and have at least one hydroxyl group in the molecule. , (C1 above fa) or middle) hydrogenated polybutadiene-based acrylic-modified ols (0 per molecule)
．． A combination of an acrylic-modified hydrogenated polybutadiene polymer having 5 to 1.2 (meth)acryloyl groups and a hydroxyl group-containing radically polymerizable monomer or a mixture of a hydroxyl group-containing radically polymerizable monomer and a hydroxyl group-free radically polymerizable monomer consisting of a polymer with a number average molecular weight of 7. OOO~3o, ooo, hydroxyl group is 10~500
KOHmg/g of acrylic modified hydrogenated polybutadiene polyols.

In particular, the above-mentioned (cl) acrylic-modified hydrogenated polybutadiene polyols using the above-mentioned Tal hydrogenated polybutadiene polyol as a starting material are preferably used.

The acrylic-modified hydrogenated polybutadiene-based polymer is a hydrogenated polybutadiene-based (poly)ol or a 1,2-polybutadiene-based polymer having a main chain as described above, and has at least one carboxyl group in the molecule. Hydrogenated polybutadiene-based carboxylic acids having
1 mol of a (meth)acryloyl group-containing compound, such as glycidyl (meth)acrylate, etc.
．． A method of esterifying 2 moles of hydrogenated polybutadiene/(poly)ols with a diisocyanate compound and hydroxy(meth) in advance.
It can be easily produced by an addition reaction of a prepolymer obtained by an equimolar reaction with an acrylate, or an addition reaction of iminol (meth)acrylate with hydrogenated polybutadiene carboxylic acids described in the TCT.

As the hydroxyl group-containing radical polymerizable monomer to be copolymerized with the acrylic-modified hydrogenated polybutadiene polymer, alcohols such as allyl alcohol and methalyl alcohol, phenols such as vinylphenol, 2-hydroxyethyl (meth)acrylate, and hydroxybutyl (meth)acrylate can be used. ) (Meth)acrylic esters such as acrylate are used alone or as a mixture of two or more.

In addition, methyl (meth)azilylate, ethyl (
(meth)acrylic acid esters such as meth)acrylate, i-propyl(meth)acrylate, n-butyl(meth)acrylate-3ter-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and cyclohexyl(meth)acrylate aliphatic vinyl esters such as vinyl acetate and vinyl propionate, styrene, chlorostyrene, and α-methylstyrene.

Aromatic vinyl compounds such as vinyltoluene, vinylpyridines such as 4-vinylpyridine and 2-vinylpyridine,
(Meth)acrylamides, (meth)acrylonitrile, (meth)acrylic acid glycidyl ester, etc. are used singly or as a mixture of two or more.

Component B lacquer is produced using the so-called refining method, in which raw lacquer is dehydrated and purified, and is produced using a so-called purification method, such as Sogurome lacquer, which does not contain a modifier, Nashiji method, Hakushita lacquer, and modifiers such as linseed oil to improve gloss. Compounded Shugo lacquer, Shunkei lacquer, coating method, etc. can be used, and preferably lacquer without modifiers is used.

Lacquer is a polyol whose main component is urushiol (dihydroxyphenyl), and has approximately the following composition (% by weight).

Black-eyed lacquer Shugo lacquer urushiol 83~8673~80 Rubber 8~
126-10 Nitrogen-containing compound 3-4 2-3 Water 3-4 3-4 Oil, others 0 5-10 The first liquid is the component A
It is a polyol component consisting of a mixture of
100. Preferably l 00/10≧A/B≧10
It is 0/60. If the blending ratio of component B to component A is too low, the durability and luster characteristic of lacquer cannot be obtained,
Moreover, if the amount is too large, weather resistance will decrease.

The polyisocyanate of component C used as the second liquid is:
A crosslinking agent that reacts with the polyol component of the first liquid to form a urethane bond, such as hexamethylene diisocyanate (HMDI).

Aliphatic diisocyanates such as xylylene diisocyanate (XDI) and isophorone diisocyanate (NPDI); aromatic polyisocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and naphthalene diisocyanate (NDI); Adducts, biurets, modified products, and the like can be used singly or as a mixture of two or more. In particular, in consideration of weather resistance, it is preferable to use one type of aliphatic diisocyanate or a mixture of two or more types.

The coating composition of the present invention is used by mixing the first liquid and the second liquid before coating.

Generally, the blending ratio of the polyol component of the first liquid and the polyisocyanate component of the second liquid is 1) 0.9≧OH/NGO≧
1/1.5, preferably 1) 0.9≧.

H/NG O20/1.1 is adopted. OH/N
If the CO ratio is too high or too low, the coating film will become too soft or too hard, which is not preferable.

Further, additives such as pigments, organic solvents, dispersion aids, and modifiers that are commonly used in ordinary paints can be appropriately blended into this paint composition.

There are no particular restrictions on the coating method using the coating composition of the present invention; in addition to the spray method, brush coating method, etc. that are used as coating methods for boat fishing paints, electrostatic coating methods, mechanical coating methods, etc. Can be adopted.

[For production]

The coating composition of the present invention incorporates a hydrogenated polybutadiene polyol (component A) which is highly compatible with the lacquer (component B) during urethane modification of the lacquer (component B), which is mainly composed of urushiol, which is a polyol component. It is characterized in that it is added and blended to form the first liquid.

In the present invention, the first liquid is a polyol component, which reacts with the second liquid polyisocyanate (component C) to form a strong coating film due to urethane bonds.

In particular, the coating film formed by the reaction between the hydrogenated polybutadiene polyol (Component A) and the polyisocyanate (Component C) blended into the first liquid is difficult to form because the hydrogenated polybutadiene polyol does not have unsaturated bonds. Significantly improves weather resistance.

On the other hand, the reaction rate between component B, lacquer, and component C, positive isocyanate, is slower than the reaction between component A and component C, but since component B also has a polyol component as its main component, the reaction is caused by urethane bonds. Forms a hard and strong coating. Also,
In lacquer, a polymerization reaction due to the action of the enzyme roughcase proceeds simultaneously with the urethane reaction, forming an even stronger coating film.

In particular, since there is a difference in reaction rate between component A and component B,
It is presumed that a coating film with ultra-high weather resistance due to the combination of component A will be formed without impairing the durability and gloss, which are the characteristics of lacquer.

In addition, when preparing the first liquid, the hydrogenated polybutadiene polyol of component A has excellent compatibility with the lacquer of component B, so there is little risk of affecting drying performance or storage stability, and the Component A and component B can be blended in any ratio depending on specifications such as the coating method.

〔Example〕

The present invention will be explained in more detail with reference to Examples and Comparative Examples.

However, the scope of the present invention is not limited in any way by the following examples.

(1) Hydrogenated polybutadiene polyol (sample!
A-1) Synthesis 174 g of tolylene diisocyanate (rTDIJ) was charged into a four-piece separable flask equipped with a stirrer, a dropping funnel, a nitrogen inlet, and a reflux condenser, and heated while introducing dry nitrogen. After adding a mixture of 130 g of 2-hydroxyethyl methacrylate (rHEMAJ) and 0.1 g of di-n-butyltin dilaurate (reaction catalyst) over 90 minutes, the temperature was maintained at 60°C. The HEMA1 was added to the TDII molecule containing 1) 3.8% of isocyanate.
Isocyanate prepolymer with quantitative addition of molecules (
IP) was obtained.

Next, 152 g of the inocyanate prepolymer (IP) synthesized above and a number average molecular weight of 1000 were added to the reaction apparatus used for synthesizing the isocyanate prepolymer (IP).
, hydroxyl group-containing hydrogenated polybutadiene with an iodine value of 18 and a hydroxyl value of 62 KOHmg/H (trade name: Nl5SOPHG)
1-1000. 904 g of Nippon Soda ■ was charged, heated while introducing nitrogen gas, and stirred and held at 60°C for 5 hours to produce a colorless, transparent, high-viscosity acrylic-modified hydrogenated polybutadiene (AP) containing 0.1% or less of isocyanate groups. ) was obtained.

Furthermore, 297 g of toluene and 297 g of n-butyl acetate were charged into the reaction apparatus used for the synthesis of the IP, and heated while blowing nitrogen gas to the reflux temperature of toluene (1) from 0 to
1) 88.5 g of the acrylic-modified hydrogenated polybutadiene (AP) synthesized above and 128 g of methyl methacrylate while maintaining the temperature at 5°C.

Methacrylic M128g, HEMA87.5g5n-butyl methacrylate 94g and t-butylperoxy-
A mixed solution of 6 g of 2-ethyl hexaate (organic peroxide, trade name, Perbutyl-0, manufactured by NOF) was added from the dropping funnel over 30 minutes, and after being kept at reflux temperature for an additional 30 minutes, 2-ethyl hexaate was added. .6 g of 2-azobisbutyronitrile was added and the reaction was continued for an additional 2.5 hours to obtain a hydrogenated polybutadiene polyol (PP). The obtained PP had a non-volatile content of 40% and a hydroxyl value of 40 KOHm g/
g, acid value 1.3KOHmg/g, Gardner viscosity Z (
25℃), and the number average molecular weight of the nonvolatile fraction is 28.00.
It was 0.

(2) Preparation of coating composition and coating sample (8)
Sample (P-1) 100 parts of hydrogenated polybutadiene-based polyol (PP) synthesized in item +13 above, Sogurome lacquer (urushiol 8
4%, manufactured by Fujii Urushi Kogei ■) 20 parts and Mitsubishi Carbon 92
350 (manufactured by Mitsubishi Chemical Industries, Ltd.) were mixed and sufficiently dispersed until the particle size became 10 μm or less as measured with a tube gauge to prepare a first liquid.

Next, Duranate 24 was added to 100 parts of the first solution prepared above.
After mixing 28 parts of A-90CX (polyisocyanate with 90% non-volatile content and 21% NGO, manufactured by Asahi Kasei ■), a mixed solvent of ethyl acetate/butyl acetate/toluene = 2/2/6 was added to form a Ford cup #4. The viscosity was adjusted to 12 to 15 seconds using a type viscometer.

A steel plate (75 x 150 x 1.2), which had been subjected to surface treatment in advance, was spray-painted to a dry film thickness of 30 μm. The coating film was smooth and had an excellent texture.

After drying at room temperature for 30 days, use the Sunshine Weatherometer (
Accelerated Weather Resistance Test) The result was 1,800 Hr s.
No abnormality was observed.

Sample (P-2) 100 parts of hydrogenated polybutadiene-based polyol (PP) synthesized in Section 1) above, Sogurome lacquer (urushiol 8
4%, manufactured by Nei Urushi Kogei ■) 50 copies and Mitsubishi Carbon #2
350 (manufactured by Mitsubishi Chemical Industries, Ltd.) were mixed and sufficiently dispersed until the particle size became 10 μm or less as measured with a tube gauge to prepare a first liquid.

Next, Duranate 24A-90 was added to 100 parts of this first solution.
After mixing 40 parts of CX (above), add a mixed solvent of ethyl acetate/butyl acetate/Torso-2/2/6 and adjust the viscosity to 12 to 15 seconds using a Ford cup #4 viscometer. did.

Spray coating was applied to a pre-primed IL board (75 x 150 x 1.2) so that the dry film thickness was 30 μm. The coating film was smooth and had an excellent texture.

After drying at room temperature for 30 days, it was run on a Sunshine Weatherometer (accelerated weather resistance test), and no abnormality of 1.500 hours was observed.

(e) Sample (P-3) 100 parts of hydrogenated polybutadiene-based polyol (PP) synthesized in item (1) above, 7s
59M well lacquer craft special) 20 copies and Mitsubishi Carbon #23
50 (manufactured by Mitsubishi Chemical Industries, Ltd.) were mixed and sufficiently dispersed until the particle size was 10 μm or less as measured with a tube gauge to prepare a first liquid.

Next, add Dura and Nate 24A-9 to 100 parts of this first solution.
After mixing 27 parts of 0CX (above), add a mixed solvent of ethyl acetate/butyl acetate/Torso-2/2/6 and adjust the viscosity to 12 to 15 seconds using a Ford cup #4 viscometer. did.

A steel plate (75 x 150 x 1.2), which had been subjected to surface treatment in advance, was spray-painted to a dry film thickness of 30 μm. The coating film was smooth and had an excellent texture.

After drying at room temperature for 30 days, use the Sunshine Weatherometer (
As a result of subjecting it to an accelerated weather resistance test, no abnormality was observed for 1, 300 hours.

(d+ Comparative sample (C-1) Toluene was added to Shugo lacquer (75% urushiol, manufactured by Fujii Urushi Kogei ■) and the viscosity was adjusted to 20 to 3 with a Ford cup #4 type viscosity needle.
The viscosity was adjusted so that it was 0 seconds.

A steel plate (75 x 150 x 1.2), which had been subjected to surface treatment in advance, was spray-painted to a dry film thickness of 30 μm. The coating film was smooth and had an excellent texture.

After drying at room temperature for 30 days, use a sunshine meter (
As a result of subjecting the product to an accelerated weather resistance test, an abnormality occurred after 300 hours.

[el Comparative sample (C-2) 100 parts of acrylic polyol (Acridic A-801, manufactured by Dainippon Ink ■), Sogurome lacquer (Urushiol 84)
%, manufactured by Fujii Urushi Kogei ■) 20 parts and Mitsubishi Carbon #23
50 (manufactured by Mitsubishi Chemical Industries) were mixed and sufficiently dispersed until the particle size was 10 μm or less as measured with a tube gauge to prepare a first liquid.

Next, add Duranate 24A to 90 to 100 parts of this first solution.
After mixing 28 parts of CX (above), add a mixed solvent of ethyl acetate/butyl acetate/toluene = 2/2/6 and adjust the viscosity to 12 to 15 seconds using a Ford cup type 4 viscometer. did.

Spray coating was applied to a steel plate (75XI5Q1.2) that had undergone surface treatment in advance so that the dry film thickness was 30 μm. After drying the paint film at room temperature for 30 days, it was subjected to a Sunshine Weatherometer (accelerated weather resistance test), and an abnormality occurred at 1.0 OOHrs.

ff) Comparative sample (C-3) Alkyd polyol (halifthal C0G-40-50
7. Mix 100 parts of Harima Chemical Industries special product), 20 parts of Sogurome lacquer (84% urushiol, manufactured by Nei Urushi Kogei ■) and 4 parts of Mitsubishi Carbon #2350 (manufactured by Mitsubishi Chemical Industries ■),
A first liquid was prepared by thoroughly dispersing the particles until the particle size was 10 μm or less as measured with a tube gauge.

Next, Duranate 24Δ-90 was added to 100 parts of this first solution.
After mixing 28 parts of CX (above), add a mixed solvent of ethyl acetate/butyl acetate/toluene = 2/2/6 and adjust the viscosity to 12 to 15 seconds using a Ford cup #4 type viscometer. did.

A steel plate (75 x 150 x 1.2), which had been subjected to surface treatment in advance, was spray-painted to a dry film thickness of 30 μm. After drying the coating film at room temperature for 30 days, it was subjected to a Sunshine Weatherometer (accelerated weather resistance test), and an abnormality occurred after 500 hours.

(3) Various coating film tests The following coating film tests were conducted on the coating film samples prepared in the above item (2).

The results of each test are shown in Table 1 along with the results of the accelerated weathering test.

fat Initial gloss 60" specular reflectance before accelerated weathering test (bl Final gloss 60 parts specular reflectance after accelerated weathering test (C) Flesh, skin texture 4 levels from A (good) to D (bad) by visual inspection Judgment (di Accelerated Weather Resistance Test by Sunshine Weatherometer (hereinafter referred to as the margin) As shown in Table 1, the coating film formed using the legal coating composition of the present invention has excellent durability, texture, and The final gloss after the accelerated weathering test is excellent.

〔Effect of the invention〕

As shown in the examples above, by using the coating composition of the present invention, it is possible to form a coating film with ultra-high weather resistance without impairing the inherent properties of lacquer, such as durability and texture.

Therefore, it is suitable not only for traditional crafts such as lacquerware where weather resistance is not a problem, but also as a paint for high-grade coatings in fields where high weather resistance is required, such as shrines and temples, and other outdoor coatings.

The present invention provides a coating composition with excellent weather resistance that retains the characteristics of lacquer, and has extremely great industrial significance in the paint industry and coating industry.

Claims (2)

[Claims] (1) The main chain is a homopolymer of butadiene or a copolymer of butadiene and a vinyl compound, and 50% or more of the butadiene units are 1,2-bonds. The unsaturated bonds of the 10,2-butadiene-based polymer are hydrogenated and saturated. A polyol component consisting of a mixture of hydrogenated polybutadiene polyol [component A] and lacquer [component B] having at least one hydroxyl group in the molecule and a hydroxyl value of 10 to 500 KOHmg/g is used. A coating composition characterized by being a one-component type and a two-component type containing polyisocyanate [component C] as the second component. (2) In claim (1), the blending ratio (weight basis) of both components A and B of the first liquid is 100/5≧A/B≧10
A coating composition characterized in that it is 0/100.