JPS62257935A - Curable composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition giving a coating film having excellent hardness and heat-resistance and variable flexibility and toughness, by using a polythiol compound and an unsaturated urethane oligomer composed of an unsaturated monoalcohol having triple bond, a polyether, etc. CONSTITUTION:The objective composition suitable for paint, etc., contains, as active components, (A) an unsaturated urethane oligomer having >=2 alkyne- type unsaturated bonds in one molecule and produced by reacting a polyvalent isocyanate to (a) an unsaturated monoalcohol having triple bond (e.g. propargyl alcohol), a polyvalent isocyanate and a polyether having >=2 hydroxyl groups in one molecule (e.g. polyoxypropylene glycol) or (b) an unsaturated polyether produced by reacting the above unsaturated monoalcohol with a monoepoxide and (B) a polythiol compound having >=2 thiol groups in one molecule.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a curable composition suitable for paints, coating agents, lining agents, adhesives, etc. Concerning possible compositions.

[Conventional technology]

It is known that a polyene compound or oligomer having two or more ethylenically unsaturated bonds in one molecule and a monothiol compound are used in combination, and a photoreaction initiator is added to prepare a photocurable resin composition.

As the ethylenically unsaturated bond, allyl ether group C)12=CH-CH2-0-1E
l Allyl ester group CH2=CH-Cf(2-0-C-
1 Acryloyl group CH2-CH-C-1CH30 Polythiol compounds are generally mainly esters of polyhydric alcohols and caldic acid containing a thiol group.

The above-mentioned composition is a photoreaction initiator (hereinafter simply "initiator").
When irradiated with energy rays (ultraviolet rays, electron beams, etc.) in the coexistence of so-called H-transfer polymerization (
(hereinafter referred to as "photocuring"). However, in the case of electron beams, an initiator may not be necessary.

[Problem that the invention seeks to solve]

Although these existing photocurable resins made from combinations of polyene-polythiol compounds have excellent adhesion to metals, they also have the following drawbacks, which are major obstacles to their practical application.

(a) Hard resin is difficult to obtain and remains at a semi-hard level.

(b) Cured resins tend to be brittle.

(c) It has a short shelf life and immediately glues when the polyene and i91J thiol are mixed.

) Poor heat resistance.

In particular, items (a), (b), and (b) are strongly required to be improved from the viewpoint of physical properties of the coating film.

[Means for solving problems]

The present inventors have been studying improvements to polyene-polythiol type photocurable resins, but have found that it is difficult to solve the above-mentioned problems by using the above-mentioned types as polyene compounds. As a result of our research, we submitted to the previous paper that a system using a monoalcohol having a triple bond as an unsaturated component exhibits properties completely different from those of ethylenically unsaturated bonds, and that the above-mentioned drawbacks can be almost completely improved. Furthermore, the present inventors have discovered that an amorphous unsaturated urethane oligomer useful for paints and adhesives can be obtained by using polyethers as a modifying component, leading to the completion of the present invention.

That is, the present invention relates to [I] unsaturated monoalcohols having triple bonds (hereinafter referred to as unsaturated monoalcohols), polyvalent isocyanates, and polyethers having two or more hydroxyl groups in one molecule (hereinafter referred to as polyethers). A polyvalent isocyanate is reacted with an unsaturated polyether (hereinafter referred to as an unsaturated polyether) obtained by reacting a monoepoxide with the unsaturated monoalcohol (hereinafter referred to as an unsaturated polyether). unsaturated urethane oligomer having two or more alkyne type unsaturated bonds in one molecule (hereinafter referred to as unsaturated urethane oligomer) obtained by [II] two or more alkyne type unsaturated bonds in one molecule. The object of the present invention is to provide a curable composition containing a polythiol compound having a thiol group (hereinafter referred to as a polythiol compound) as an active ingredient.

[Effect]

The system using the unsaturated urethane oligomer of the present invention provides a coating film that is incomparably harder and tougher than conventional polyene-polythiols, and is also highly heat resistant.

Triple bonds in unsaturated urethane oligomers are essentially different from double bonds such as in ryoryl groups. That is, when an allyl ether group is used in combination with a polythiol, the ethylenically unsaturated group acts only as a monofunctional group.

However, the triple bond in the unsaturated urethane oligo9mer has a bifunctional ability as shown in the following formula. It is presumed that it is possible to exhibit hardness and heat resistance, and to significantly improve the properties of the cured resin.

f12C-CH-CH2-0- The unsaturated urethane oligomer CI) of the present invention typically contains glopagyl alcohol as an unsaturated monoalcohol, tolylene diisocyanate as a polyvalent isocyanate, and polyether as a polyether. It can be produced using oxypropylene glycol, but its structural formula is as follows: Although aliphatic alcohols having up to 12 carbon atoms and having a triple bond in the molecule can be used, glopargyl alcohol obtained by the reaction of acetylene and formaldehyde is representative, and the present invention also deals with its handling. It is also the most commonly used because it is easy to use.

Other compounds called acetylene alcohols can also be used as the unsaturated monoalcohol of the present invention. These compounds are synthesized by the reaction of alcohol and ketones, such as 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, and 3,5-tumethyl-1-ol. Hexyn-3-ol, etc. Furthermore, 3,6-cymethyl-4-octyne-3,6-
Diol, 2,4,7.9-tetramethyl-5-decyne-4°7-sool and 2. Examples include S-dimethyl-3-hexyne-2,5-diol, which can of course also be used as the unsaturated monoalcohol of the present invention.

As the polyvalent isocyanate that reacts with unsaturated monoalcohols and polyethers, commonly available commercially available ones can be used, such as those listed below. tolylene diisocyanate) (including mixtures of 2,4,2,6), xylylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, sophenylmethane diisocyanate, nogura phenylene diisocyanate hexamethylene diisocyanate, hydrogenated diphenylmeth-7noindianate, 1.5-
naphthylene diisocyanate.

Polyethers that are used in combination with unsaturated monoalcohols to diversify physical properties include polyethers that have two or more hydroxyl groups in one molecule and are currently used in polyurethane-related applications. Available.

For example, polyoxypropylene glycol with a molecular weight of 200 or more, polyethylene glycol, a block copolymer of polyethylene glycol and monopropylene glycol, polycaprolactone whose terminal group is a hydroxyl group, polyoxybutylene glycol, polyoxytetramethylene glycol, polyoxy propylene triol,
Examples include poly(oxypropylene) poly(oxyethylene) poly(oxypropylene) triol, other pentaerythritol or sorbitol (oxyethylene) polyol, Isu(oxypropylene) triol, and adducts of ethylene diamine and alkylene monoepoxide. .

The unsaturated urethane olico-9mer of the present invention is synthesized by reacting an unsaturated monoalcohol and a polyvalent isocyanate, and then reacting a polyether. It may also be reacted with a monoalcohol.

The reaction ratio of hydroxyl groups and isocyanate groups in unsaturated monoalcohols and polyethers is substantially 1:1.
It is appropriate that the ratio is 0.8:1.2~
It can be used in the range of 1.2:0.8.

The proportion of 4-reather to be used may be changed as appropriate depending on the application, but practically it is
It is used in a proportion of 95 mole, preferably 20 to 80 mole. The reaction is carried out neat or in a solvent, reaction diluent.

Furthermore, the monoepoxides used in the present invention include alkylene monoboxides such as ethylene oxide and propylene oxide; Examples include enyl glycidyl ester and cresyl glycidyl ether.

Contrary to unsaturated monoalcohols and monoepoxides.

The permissible ratio is substantially 1:1 (molar ratio) to 1:20 molar. The reaction ratio between the resulting unsaturated polyether and the polyvalent isocyanate is substantially 1:1 (hydroxyl group: isocyanate group), practically 0.8:1.
The range of 2 to 1.2:0.8 is preferable.

Of course, it is also possible to use an unsaturated monoalcohol in which a portion (for example, preferably 50% or less) of the unsaturated monoalcohol is replaced with a saturated monoalcohol within a range that does not impair the properties of the cured resin.

The polythiol compound used in the curable composition of the present invention is not particularly limited, but from a practical standpoint, ester compounds of polyhydric alcohols and thioglycolic acid or thiopropionic acid are preferred.

Examples of these compounds include, for example, pentaerythritate tetrathioglycolate, pentaerythritate tetrathiozolobionate, trimethylolpronocentrithiopropionate, hex f7 dioldithioglycolate, hexanedioldithioglopinate, "bisphenol" Examples of the alkylene monoepoxide adducts of A include thiopropionate and thiobisphenol.

The blending ratio of the unsaturated urethane oligomer and the polythiol compound can be selected within a wide range, whereas good results cannot be obtained unless the double bond and thiol group are approximately 1:1 when using a dIJene compound. It is possible. For example, since 1 equivalent of the triple bond of the unsaturated urethane oligomer of the present invention reacts with 2 equivalents of thiol group,
Originally, only such a blending ratio should be good, but a practical coating film can be obtained even with 0.5 equivalents of thiol group per equivalent of triple bond, and even if 2 equivalents or more is used, the cured coating film will not be obtained. No sudden drop in physical properties was observed, and on the contrary, good results were obtained in terms of adhesion to metals.

Therefore, the ratio of the thiol group to 1 equivalent of triple bond may be in the range of about 0.2 to 4 equivalents, but is usually preferably used in the range of 0.5 to 3 equivalents.

The curable composition of the present invention is easily cured by irradiation with energy beams such as heat, light, and electron beams. In the case of photocuring, it is necessary to use a photoreaction initiator. The amount of the initiator added is 0.01% or more, preferably 0.5 to 5%.

Typical photoreaction initiators include commercially available types such as Ciba's Irgacure 651 (-4-nordimethyl ketal) and Merck's Darocure 1173 (2-hydroxy-
(2-methylglobiophenone), 2-chlorothioxanthone, pe/siphenone, and benzoin ethers. In addition, a sensitizer such as amines may be used in combination, if necessary.

Furthermore, it is advantageous to use a stabilizer such as polyhydric phenols or quinones in order to improve the storage stability of the unsaturated urethane having an alkyne unsaturated bond and a polythiol compound according to the present invention at room temperature. be.

The curable composition of the present invention may contain colorants, reinforcing agents, fillers, polymers, etc., if necessary.

〔Example〕

The present invention will be further explained with reference to Examples below.

Example 1 Synthesis of unsaturated urethane oligomer (4) Into a 2t cell I4 rubble flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas inlet tube, glott4gyl alcohol 56,9,2
．． 174 g of 4-tolylene diisocyanate and 170 y of ethyl acetate were charged and reacted at 60°C in a nitrogen gas stream for 3 hours.
000, branched type using triol as an initiator) 770g
, 1 g of dibutyltin dilaurate, and further heated at 60°C for 3
After reacting for a period of time, infrared analysis revealed that free isocyanate groups had completely disappeared.

The unsaturated urethane oligomer obtained by adding 0.1 g of hydroquinone was a slightly yellow liquid.

To 117 g of unsaturated urethane oligomer (A), 45.9 g of pentaerythritte tetrathiopropionate (specific gravity of alkynic unsaturated bond and thiol group is approximately 1:2), and 3.0 g of Irgacure Φ651 from Chipa Co. as an initiator. 59
In addition, a 35μ thick copper foil was coated with a percoater to a thickness of 30μ. .

After leaving it at room temperature for 1 hour, heat it at 80°C for 30 minutes to remove the solvent, and place it under the rung of a 2 kW ultraviolet irradiation device at 15 cIn.
was passed at a speed of 2 m 1 min.

Curing of the coating occurred in one pass.

As for the physical properties, as shown in Table 1, it had excellent adhesion and excellent heat resistance.

Table 1 Hardness B Corner adhesion test 100/100 180° bending 1 mφ Passed Example 2゜ The composition used in Example 1 except that the cure% 51 was removed was similarly applied to copper foil. The coating film, which had been heated at 80° C. for 30 minutes to remove the solvent, was irradiated with a dose of 3 megarads in air using a scanning type electron beam irradiation device with an output of 350 kV.

The physical properties of the cured coating film were as shown in Table 1.

Example 3 In the same manner as in Example 2, the composition except for Irgacure≠651 was applied to copper foil and heated at 60°C for 30 minutes, 80°C for 30 minutes, and then 150°C for 2 hours to cure the coating film. I let it happen.

The physical properties of the cured coating were as shown in Table 1.

Example 4゜Unsaturated urethane oligo ff-(B)O synthesis stirrer,
3-) f/L/-1-butyne-
3-ol (Air Grodak & Chemicals Ltd. trade name Orfin B) 84,9゜Isophorone diinquanate 222II, ethyl acetate 94I and sibutyltin dilaure) 0.59 was charged and reacted for 3 hours at 60°C in a nitrogen stream. , a polyether CH of the following formula in which approximately 3 moles of ethylene oxide are added to each of the 7 enolic hydroxyl groups of a bisphenol.

Add 250p of
After the time reaction, it was determined that free isocyanate groups disappeared as a result of infrared analysis.

0.1 g of hydroquinone was added to obtain a pale yellow liquid unsaturated urethane oligomer (B).

70 g of unsaturated urethane oligomer, 26.9 g of pentaerythrite tetrathioglycole (equivalent ratio of alkyne unsaturated bond to thiol group is approximately 1:2.2)
, Merck's ProCure Φ1173 was used as an initiator.
In addition, after polishing with sandpaper A of 600 mm, 1.
1. It was coated to a thickness of 50 μm on a steel plate that had been washed with 1-trichloroethane.

- After being left overnight, it was heated at 80° C. for 20 minutes to remove the solvent, and cured using the same ultraviolet irradiation equipment and conditions as used in Example 1.

Curing occurred in one pass.

The physical properties of the cured coating film are shown in Table 2, and the coating film was found to have antirust ability.

Table 2 Hardness H Grind adhesion test 100/100 cross cut Passed 90'' bending No peeling occurs.

Example 5 Synthesis of unsaturated urethane olico 9mer C) Into an IL-gableable flask equipped with a stirrer, a reflux condenser, 11 dropping funnels, and a thermometer, 569. diallylphtale) 94,! i+.

0.5.9% of trifurinated boron ether adduct was charged, and phenylglycidel ether 4509 was added dropwise at 40°C.

The reaction is carried out at 60°C or lower, and after the dropwise addition is completed, the reaction is carried out at 60°C for 3 hours.

As a result of infrared analysis, no epoxy groups were found, and the hydroxyl value was 126.
An unsaturated polyether was obtained.

Furthermore, diphenylmethane diisocyanate 120I, diallylphthalate) 86.1 diptyltin dilaurate 2I
was added and reacted at 60 to 65° C. for 3 hours, and as a result of infrared analysis, it was determined that the free isocyanate groups had completely disappeared.

Yellowish brown, viscous liquid unsaturated urethane oligomer (C)
was gotten.

Synthesis of unsaturated urethane oligomer 〇) Using allyl alcohol 58I instead of pro-gyl alcohol in Q,
A yellow-brown, viscous unsaturated urethane oligomer 〇) was obtained by the same synthesis.

Unsaturated urethane (C) 100,! i', 0.05 g of methylhydroquinone, 50 g of pentaerythritte tetrathiopropionate, and Procure Φ11 as an initiator.
Sample III) with 3g of 73 added and unsaturated urethane 1)
To 100.9, add 37 g of methylhydroquinone 0.05.9° pentaerythritte tetrathiopropionate and Procure≠1173 to 3. ! i+, added sample [II]
Each was coated on a Sonderite steel plate to a thickness of 50 μm, and passed through the lower 10 ports of the ultraviolet irradiation device similar to Example 1 at a speed of 2 m/min.

Curing occurred in one pass.

The physical properties of the cured coating film are shown in Table 3, and unsaturated urethane (C) having an alkyne unsaturated bond was excellent.

Table 3 Unsaturated urethane (Q Unsaturated urethane (D) hardness
2HB Cross cut Pass Pass is the bread adhesion test 100/100 96/100 Example 6゜Unsaturated urethane oligomer (odor synthesis stirrer, reflux condenser, dropping funnel, thermometer T-equipped 1t separable flask, Block kill alcohol 56,9.) Luet 84,9.3 fluorinated boronate ether adduct 0.5.9 is charged and styrene oxide 360I is added dropwise at a temperature of 40''C.

The temperature is kept at 60-65°C.

When the reaction was carried out at the same temperature for 5 hours after completion of the dropwise addition, no epoxy groups were observed as a result of infrared analysis, and an unsaturated polyether with a hydroxyl value of 141 (solid content) was obtained.

Further, 85 g of hexamethylene diisocyanate and 1.5 g of dibutyltin dilaurate were added and the mixture was reacted at 60° C. for 5 hours. As a result of infrared analysis, free isocyanate groups completely disappeared.

Pale yellowish brown, viscous unsaturated urethane orico 9mer(g))
was gotten.

To 100 parts of unsaturated urethane olico 9mer ■, add 70I of trimethylolgulonotrithioglopionate (approximately 1 thiol group per equivalent of alkyne unsaturated bond).
．． 6 equivalents), and further added 3 g of Ciba's Irgacure ◆651 as an initiator, and after coating it on a glass plate to a thickness of 50 μm, it was heated at 80° C. for 30 minutes. The sample was passed through a 10 cM tube under an ultraviolet irradiation device with an output of 2 kW at a speed of 2 pulses/min.

Curing occurred in one pass.

The physical properties of the coating film are shown in Table 4, and it showed good adhesion to the glass plate.

Table 4 Hardness F Goban adhesion test 100/100 cross cut test Passed In addition, 10 lengths of a glass plate measuring 20 gourds x 15 meters x 5 meters were coated with resin of the same formulation, and after being left overnight, it was coated with a resin of 1010 meters x 1.
They were overlapped with an area of 5 and irradiated with light in the same manner.

Curing occurred in one pass.

When examining the adhesive strength due to compressive shearing, it was found that the glass itself was destroyed.

〔Effect of the invention〕

By using an unsaturated urethane oligomer having triple bonds, the curable composition of the present invention can exhibit hardness and heat resistance that could not be achieved with polyene-polythiol systems having ethylenically unsaturated groups. By using polyether as a modifying component, it has become possible to freely change the flexibility and toughness.

Claims (1)

[Claims] 1. [I] Obtained by reacting an unsaturated monoalcohol having a triple bond with a polyvalent isocyanate and a polyether having two or more hydroxyl groups in one molecule,
or an unsaturated polyether obtained by reacting a monoepoxide with an unsaturated monoalcohol containing a triple bond and having two or more alkyne-type unsaturated bonds in one molecule obtained by reacting a polyvalent isocyanate. A curable composition containing as active ingredients a urethane oligomer and [II] a polythiol compound having two or more thiol groups in one molecule. 2. The curable composition according to claim 1, which contains 0.01 to 0.5% by weight of a photoreaction initiator.