JPS6389574A - Extensible paint composition - Google Patents

Abstract

PURPOSE:To provide a paint compsn, which has good compatibility and gives a coating film which has excellent extensibility and weather resistance and is not broken when applied to exterior finish materials for buildings, etc., by mixing a polyisocyanate obtd. by a specified reaction with a fluoropolyol. CONSTITUTION:A paint compsn. is obtd. by mixing a polyisocyanate having isocyanate groups at its terminals, which is a reaction product of an aliph. diisocyanate and/or alicyclic diisocyanate (pref. hexamethylene diisocyanate) with a branched 3-10C alkylenediol (e.g., 1,3-butanediol), with a fluoropolyol having at least two OH groups in an equivalent ratio of NCO to OH of 0.5-2.0. The paint compsn. has good compatibility and given a coating film which has excellent extensibility and weathersbility and is not broken applied to exterior finish materials for buildings, floors, waterproofing roofs, plastics, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a two-component polyurethane coating composition having extensibility. More specifically, the present invention relates to a coating composition that has extensibility and excellent weather resistance and is used for architectural exterior materials, roof ink materials, plastics, and the like.

(Prior art) In recent years, as exemplified by wing materials used for architectural exteriors,
There is an increasing demand for paints with excellent elongation and weather resistance. In response to these * Are known.

However, it is extremely difficult to obtain a coating composition that simultaneously satisfies both extensibility and weather resistance properties.

In other words, when the extensibility of gold was increased using the potato method described in 011, the weather resistance was stubbornly reduced69, and there was an antinomic relationship between weather resistance and extensibility. In addition, it is known that polyurethane paints, which are made of fluorine-containing polyol as a main ingredient and cured with polyvalent isocyanate, as described in Japanese Patent Application No. 55-108189 and No. 56-133269, have excellent weather resistance. However, the compatibility with inocyanates and plasticizers is insufficient, and the usable isocyanates and '51 plasticizers are limited to 6 degrees, making it impossible to obtain coatings with high extensibility.

(Problems to be Solved by the Present Invention) An object of the present invention is to obtain a coating composition that uses a fluorine-containing polyol that has excellent weather resistance, has good compatibility, and has extensibility. .

(Means for solving the problem) The present inventors solve the above ii rtfJ problem/
As a result of extensive research, we have found that aliphatic diisocyanates or alicyclic diisocyanates can be used in combination with specific diols.
By combining a polyisocyanate having an isocyanate group at the end obtained by adding S and a fluorine-containing polyol, a composition can be obtained that has sufficient compatibility, has coating film extensibility, and has excellent weather resistance. The present inventors have found that the above problem can be solved, and have completed the present invention.

That is, the present invention provides an anti-16 combination of an aliphatic diisocyanate or an alicyclic diisocyanate alone or a mixture thereof and a branched alkylene diol having 5 to 10 carbon atoms.
It is characterized by mixing the product polyisocyanate having an isocyanate group at the end with a fluorine-containing polyol having two or more hydroxyl groups at an NCO/OH equivalent ratio in the range of 0.5 to 2.0. Regarding the coating composition, the compatibility between the fluorine-containing polyol and the polyisocyanate is good, and the resulting coating film has extensibility and excellent weather resistance.

Examples of the aliphatic diisocyanate or alicyclic diisocyanate in the present invention include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, inphorone diisocyanate, hydrogenated xylylene diisocyanate, and 114-diisocyanate. Examples include cyclohexane, but particularly preferred is hexamethylene diisocyanate. These diisocyanate compounds can be used alone or in appropriate combinations.

The branched fulkylene diol having 3 to 1 degrees of carbon atoms used in the present invention has a saturated hydrocarbon skeleton, or
The chain may contain an ether bond, an ester bond, etc. Examples of these diols include, for example, 1,2-
Propanediol, 1.2-butanediol, 1.3-
Butanediol, 2,3-butanediol, 2-methyl-1,2-nia'lovandiol, 1,2-bentanediol, 2,3-bentanediol, 3-methyl-1
, 2-butanediol, 2-methyl-1,2-butanediol, 2-methyl-2,3-butanediol, 2.5
-dimethyl-2゜3-butanediol, 2,4-bentanediol, 2-methyl-2,4-butanediol, 2
, 4-dimethyl-2,4-bentanediol, hexamethyltrimethylene glycol, neopentyl glycol, 2.2-dimethyl-1,3-butanediol, 2.2
-dimethyl-1,3-bentanediol, 2,2.4-
Trimethyl-1,3-bentanediol, 1,4-pentanediol, 2-methyl-2,5-bentanediol, 3-methyl-2,5-bentanediol, 1,4-hexanediol, 2.5-dimethyl -2゜5-hexanediol, dipropylene glycol, 3-methoxy-1
, 2-propanediol, 3-butoxy-1,2-propanediol, 2-ethyl-1,3-hexanediol, and the like.

These may be used alone or in any combination. Particularly preferred among these diols are 1°3-butanediol, 2,3-butanediol, neopentyl glycol, and 2-ethyl-1,3-hexanediol.

The alkylene diol to be reacted with the aliphatic diisocyanate or alicyclic diisocyanate needs to have a branch as described above. Unbranched diols, such as ethylene glycol, 1°5-propanediol, 1
．． 4-butanediol, 1,5-bentanediol, 1
．． When using 6-hexanediol, diethylene glycol, etc., the reaction product polyisocyanate is solid and 7'(υ, extremely poorly soluble in organic solvents).
The compatibility with the fluorine-containing polyol was insufficient, which is contrary to the purpose of the present invention. Furthermore, when a diol having 11 or more carbon atoms is used, it is not preferable because the viscosity of the obtained polyisocyanate is too high, the resulting polyisocyanate becomes solid, and the compatibility with the fluorine polyol is insufficient. . In addition, polyisocyanates having a billet structure or an isocyanurate structure, which are often used as curing agents in general polyurethane paints, are undesirable because they have poor compatibility with fluorine-containing polyols and lack extensibility. .

The production of a polyisocyanate having fewer isocyanate groups, which is obtained by reacting the aliphatic diisocyanate or alicyclic diisocyanate used in the present invention with a branched alkylene diol and removing the excess diisocyanate by purification, is generally known. For example, the method described in Japanese Patent Application No. 55-65406 can be used.

The fluorine-containing polyol having two or more hydroxyl groups used in the present invention is a vinyl monomer copolymerizable with a fluoroolefin or a fluorine-containing vinyl monomer and a hydroxyl group-containing vinyl monomer as essential components. It is a polyol soluble in an organic solvent obtained by copolymerizing with and, for example, according to Japanese Patent Application No. 55-108189 and No. 56-133269. Commercially available products include Lumi 7F:1 LF-100, I, and F-20 from Asahi Glass Co., Ltd.
0, LP-300, LF-60i, etc.

The mixture of the polyisocyanate having an isocyanate group at the terminal and the fluorine-containing polyol preferably has an NCO/OH equivalent ratio of 0.5 to 2.0. If this ratio is less than 0.5,
Weather resistance, solvent resistance, etc. are poor, and if it exceeds 2.0,
It is not preferable because the drying property becomes slow.

Furthermore, additives commonly used in polyurethane paints, such as curing accelerating catalysts, ultraviolet absorbers, antioxidants, and leveling agents, can also be added to these mixtures.

(Effect of the invention) The uninvented Tatebayashi composition has good compatibility and is suitable for building exterior materials,
When applied to floors, roof waterproofing, plastics, etc., it forms a coating film that has excellent elongation properties and follows cracks in the base and the base, and does not cause rupture of the film.

It also forms a coating film with excellent weather resistance.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.
In these examples, the present invention is not limited to these examples, parts are parts by weight, and m is m. In addition, in the extensibility test in the examples, those that showed a breaking elongation of 150% or more are @, those that are 100 seconds or more are ○, and 5.
A value of 0 or more is expressed as Δ, and a value of so1 or less is expressed as ×.

Production Example 1 2520 parts and 104 parts of neopentyl glycol were mixed into 1
1 at 120C using 260 parts of trimethyl phosphate as a solvent.
Allowed time to react. Using a # membrane evaporator, the reaction solution was reduced to 0.22
The viscosity at 25C is 1 as the bottom liquid from which unreacted HMDI and solvent are removed under the conditions of 160C.
A polyisocyanate of 300 Cp and an NGO content of 18.13% was obtained.

Production Examples 2 to 4 The same reactions and purification as in Production Example 1 were carried out except that the diisocyanate and diol in Production Example 1 were changed to those shown in Table 1. The characteristic values of the obtained polyisocyanate are also shown in Table 1.

Example 1 10.5 parts of the 9-polyisocyanate obtained in Production Example 1 was diluted with a large amount of ethyl acetate, mixed with 100 parts of Lumiflon LF-100 (manufactured by Asahi Glass Co., Ltd.), and a dry film thickness was formed on a Teflon plate. After drying under 20C and 65RH for 7 days, the coating film was peeled off and the transparency was observed with the naked eye.The same coating film was coated with a width of 1o+u.
Cut to length 701H11, chuck pressure i 50 MM
When I did a tension test at a speed of 50t1M1 minute,
A coating film having elongation properties showing a breaking elongation of 105 and a rank of Q was obtained.

The same paint formulation was brushed onto a slate board so that the dry film thickness was 50μ, and after drying for 7 days under 20C65RH%, an accelerated weathering test was conducted for 1000 hours under the conditions specified in JIS A 6910. However, the gloss decreases,
No changes such as discoloration, cracking, or peeling were observed.

Examples 2 to 5 Similar to Example 1, the polyisocyanate and polyol were changed as shown in Table 2, and the test results are also shown in Table 2.

Comparative Examples 1 to 4 Table 2 also shows the results of tests conducted in the same manner as in Example 1, with the polyisocyanate and polyol changed as shown in Table 2.

Table 1 The numbers within 0 in Table 1 indicate the amount (parts) to be prepared.

Abbreviation in Table 1 IPI) I: Inphorone diisocyanate 1.3-
BG: i,! -butanediol 2-Et-H
D: 2-ethyl-1,3-hexanediol NPG
: Neopentyl glycol Table 2 *1: HMDI polyisocyanate manufactured by Nippon Polyurethane Industries Co., Ltd. *2: HMDI polyisocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd.

Claims (3)

[Claims] (1) Aliphatic diisocyanate or alicyclic diisocyanate alone or as a mixture, and a branched carbon number 3
A polyisocyanate having an isocyanate group at the end, which is a reaction product with an alkylene diol of 1 to 10, and a fluorine-containing polyol having two or more hydroxyl groups are combined into NCO
1. A coating composition comprising a mixture of /OH equivalent ratio in the range of 0.5 to 2.0. (2) The coating composition according to claim 1, wherein the aliphatic diisocyanate is hexamethylene diisocyanate. (3) The coating composition according to claim 1, wherein the branched alkylene diol having 3 to 10 carbon atoms is 1,3-butanediol, neopentyl glycol, or 2-ethyl-1,3-hexanediol. thing.