JPH0327571B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a one-component thermosetting composition containing three types of oxime compound-blocked isocyanate groups, active hydrogen-containing groups, and (meth)acryloyl groups, which are useful for various uses including paints and molding materials. It is something. As is well known, blocked polyisocyanate compounds are polyisocyanate compounds whose isocyanate groups are stabilized with phenols, lactams, etc., and are polyesters having active hydrogen,
It is used as a one-component thermosetting composition by blending it with polyether ester, polyepoxy compound, etc. This blocked polyisocyanate compound releases a blocking agent when heated, and free isocyanate is produced, which reacts with a coexisting compound having active hydrogen to produce curability. This cured product is
It has excellent properties such as flexibility, impact resistance, and chemical resistance, so it is used for a variety of purposes. However, when such a composition is cured, the blocking agent evaporates, causing bubbles to be generated in the cured product, or
It has the disadvantage that it remains in the cured product and deteriorates the physical properties of the cured product, and an improvement is desired in applications where thick coatings are applied. Furthermore, because of foaming caused by volatilization of the blocking agent, it cannot currently be used as a molding material. Furthermore, in the paint field, in recent years there has been a desire to save resources and reduce pollution, and one of the things that meet this demand is:
The development of high-solids paints is progressing. In view of the above points, the present inventors have conducted extensive research and found that the present invention contains three types of functional groups as essential functional groups: an isocyanate group blocked with an oxime compound, an active hydrogen-containing group, and a (meth)acryloyl group. The present inventors have discovered that the composition can be made to have a high solidity and that there is almost no volatilization of the blocking agent during curing, so there is no deterioration in the physical properties of bubbles in the cured product, and the present invention has been completed. Compounds having two or more isocyanate groups (a) blocked with oxime compounds (), compounds having two or more active hydrogen-containing groups (b) (), compounds having (meth)acryloyl groups (c) ,1
one or more of the functional groups (b) and one or more of the above functional groups
(c) A compound having both functional groups (), one or more of the above functional groups (a) and one or more of the above functional groups (c)
A compound () having both functional groups (), one or more of the functional group (a) and one or more of the functional group (b), and a compound () having both the functional group (a) and one or more of the functional group (b). , (b) and (c), a compound having two or more functional groups selected from these functional groups (a), (b) and (c) per molecule ( ), and these functional groups (a), (b) and (c) are the above-mentioned compounds (), (), (), (), (), () and /
or (), it is intended to provide a thermosetting resin composition that is completely satisfied. In the composition of the present invention, the oxime compound that dissociates during curing easily undergoes an addition reaction with 2 equivalents of (meth)acryloyl groups per 1 equivalent of oxime group to form an isoxazolidine compound, which is thought to suppress volatilization. Furthermore, (meth)acryloyl group-containing compounds generally have low viscosity and non-volatility, and are effective in reducing the viscosity of the resin composition, so the amount of solvent used can be reduced and high solidity can be achieved. Therefore, the composition of the present invention can be applied to the field of coatings, where resin compositions containing blocked isocyanates have conventionally been used, and to the fields of adhesives, molded products, laminates, etc., which can take advantage of their low foaming characteristics. Compounds having two or more functional groups per molecule selected from the group consisting of (a), (b), and (c) used in the present invention include () isocyanate groups [functional groups] blocked with oxime compounds; (a)]; () Compounds having two or more active hydrogen-containing groups [functional group (b)]; () Compounds having two or more (meth)acryloyl groups [functional group (c)]; Compounds, () Compounds having one or more functional groups (b) and one or more functional groups (c), () Compounds having one or more functional groups (a) and one or more functional groups (c), () Compounds having one or more functional groups (a) and one or more functional groups (b); () Compounds having one or more each of functional groups (a), (b), and (c). . Examples of () include compounds that are easily synthesized by reacting a polyisocyanate compound and an oxime compound. Specific examples of polyisocyanate compounds include:
Tolylene diisocyanate, metaphenylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and further the above polyisocyanate compounds and low molecular weight polyols, polyester polyols, polyoxyalkylene polyols, polybutadiene Examples include prepolymers having terminal isocyanate groups obtained by reacting polyhydroxy compounds such as polyols and acrylic polyols. Further, specific examples of oxime compounds include aldoximes such as formaldoxime, acetaldoxime, propioaldoxime, butyraldoxime, crotonaldoxime, benzaldoxime, acetoxime, methyl ethyl ketone oxime, acetophenone oxime, Ketoximes such as benzophenone oxime and cyclohexanone oxime having one oxime group in the molecule are preferred, but those having two oxime groups such as glutaraldehyde dioxime and terephthaldehyde dioxime can also be used. In addition, when the composition of the present invention is used for adhesives, molded products, etc., a low-volatility oxime compound is preferably used. () is a compound that has two or more functional groups that are reactive with isocyanate groups such as hydroxyl groups, amino groups, and carboxyl groups, and specifically, vinyl copolymers and polyester resins that have the above-mentioned functional groups. , alkyd resins, polyamide resins, polyhydric alcohols, polyether polyols, and the like. Specific examples of () are ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, penta Polyol poly(meth)acrylate such as erythritol tetra(meth)acrylate; polyether such as diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate Polyol poly(meth)acrylate; polyester (meth)acrylate; urethane (meth)
There are acrylates, etc. () is particularly preferably a compound having a hydroxyl group and a (meth)acryloyl group,
Specific examples include partial esterification products of polyhydroxy compounds such as polyhydric alcohols, polyether polyols, polyester polyols, and acrylic polyols with (meth)acrylic acid; glycidyl ether type polyepoxy compounds, glycidyl ester type polyepoxy compounds, Addition reaction products of polyepoxy compounds such as vinyl polymers having epoxy groups in their side chains and (meth)acrylic acid; monofunctional epoxy compounds such as ethylene oxide, propylene oxide, phenyl glycidyl ether, butyl glycidyl ether and ( Addition reaction product with meth)acrylic acid; furthermore, glycidyl(meth)acrylic acid, β-methylglycidyl(meth)
Acrylate and (meth)acrylic acid, benzoic acid,
Examples include addition reaction products with monobasic acids such as stearic acid, and dibasic acids such as adipic acid, phthalic acid, and maleic acid. A specific example of () is to react a polyisocyanate compound as described above with a compound () having a hydroxyl group and a (meth)acryloyl group in a ratio such that the isocyanate group is in excess of the hydroxyl group, and then Examples include compounds obtained by blocking the reactive isocyanate group with an oxime compound. A specific example of () is obtained by reacting a polyisocyanate compound partially blocked with oxime groups and the above-mentioned active hydrogen-containing compound () so that the active hydrogen groups are in excess of the isocyanate groups. Compounds include copolymers of blocked isocyanate group-containing vinyl monomers and active hydrogen-containing vinyl monomers. As a specific example of (), a polyisocyanate compound partially blocked with an oxime group and a compound () having a hydroxyl group and a (meth)acryloyl group as described above are mixed so that the isocyanate groups are in excess relative to the active hydrogen groups. Examples include compounds obtained by reacting and further reacting unreacted isocyanate groups with the above-mentioned active hydrogen-containing compound () such that the active hydrogen groups are in excess relative to the isocyanate groups. The composition of the present invention comprises a compound () as described above.
It can be obtained by using two or more of - () and blending them so that the three functional groups (a), (b), and (c) are contained at the same time. Specific examples of such combinations are ()-()-(), ()-
()−()()−()−(),()−(
)−
(), ()-(), ()-(), ()-(
)
()-()-(), ()-()-()-(
),
Examples include ()-()-()-(). The blending ratio in the composition of the present invention is functional group (a)/
The equivalent ratio of the functional group (b) is preferably in the range of 1/0.5 to 1/2. Also, functional group (a)/functional group
The equivalent ratio of (c) is appropriately selected depending on the purpose, but for example, when used for paints, it is desirable to set it in the range of 1/0.5 to 1/2 in consideration of volatilization of the oxime compound. When used for agents, molded products, etc., it is preferably in the range of 1/1.5 to 1/2.5. Further, when a radical polymerization initiator or a redox polymerization initiator is used, the equivalent ratio of functional group (a)/functional group (c) is preferably in the range of 1/1.5 to 1/10. Furthermore, the composition of the present invention may optionally include (meth)acrylic esters having no functional group,
An aromatic vinyl compound, a radical polymerization initiator, a redox polymerization initiator, various organic solvents, pigments, fillers, stabilizers, antioxidants, etc. can be added. The curing temperature of the composition of the present invention is 80-250°C, preferably 100-180°C. In the practice of this invention, a blocked isocyanate dissociation catalyst may be used for the purpose of lowering the curing temperature.
As the catalyst, any known catalysts such as metal-based, amine-based, etc. can be used. The appropriate amount of the catalyst added is 0.01 to 5% by weight of the resin composition. The thermosetting composition thus obtained can be used without a solvent or in the form of a solution or emulsion for various purposes such as coatings, adhesives, cast molding, lamination, and others. In particular, when used as a paint, it provides a smooth coated surface with no foaming even when applied thickly, has excellent magic staining properties, and has no foaming properties when used for cast molding. The present invention will be explained below based on examples. "Parts" in the text indicate "parts by weight." Synthesis Example 1 A mixture consisting of 134 parts of trimethylolpropane, 522 parts of an 80/20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, and 393 parts of ethyl acetate was reacted at a temperature of 80°C for 6 hours. I let it happen. Next, dibutyltin dilaurate 2
of methyl ethyl ketone oxime at the same temperature.
261 parts were added dropwise and the reaction was continued for further 7 hours to obtain a resin solution having 3 oxime blocked isocyanate groups per molecule with a non-volatile content of 70% (this was referred to as ()-1). Synthesis Example 2 A mixture consisting of 400 parts of polypropylene glycol having a number average molecular weight of 400, 348 parts of tolylene diisocyanate and 400 parts of ethyl acetate was reacted at a temperature of 80° C. for 6 hours. Next, 2 parts of dibutyltin dilaurate were added, and 174 parts of methyl ethyl ketone oxime was added dropwise over 2 hours at the same temperature. After further reaction for 7 hours, the free NCO groups became 0.1% or less. Then,
Ethyl acetate was completely removed by heating at 85° C. or below under reduced pressure to obtain a highly viscous liquid resin having two oxime blocked isocyanate groups per molecule.
(This is referred to as ()-2) Synthesis Example 3 134 parts of trimethylolpropane, 342 parts of ε-caprolactone, and 0.5 parts of zinc acetylacetonate
A mixture consisting of 3 hydroxyl groups per molecule and a viscosity is called ()-1). Synthesis example 4 Polyether triol with number average molecular weight 1560
A mixture of 1,560 parts of hexamethylene diisocyanate and 504 parts of hexamethylene diisocyanate was reacted at a temperature of 80° C. for 6 hours. Next, the temperature was lowered to 60℃ and dibutyltin dilaurate 2
of cyclohexanone oxime at the same temperature.
A mixture consisting of 113 parts of β-hydroxyethyl acrylate and 232 parts of β-hydroxyethyl acrylate was added dropwise over 2 hours, and the reaction was further continued for 8 hours to form a highly viscous liquid polyether having two acryloyl groups and one oxime blocked isocyanate group per molecule. A urethane resin was obtained (referred to as ()-1). Synthesis Example 5 300 parts of toluene and 200 parts of butyl acetate were charged into a reactor equipped with a stirrer, a thermometer, a dropping funnel, and a nitrogen introduction tube, and the temperature was raised to 80°C under a nitrogen atmosphere. Next, 350 parts of styrene, 43 parts of butyl methacrylate, 200 parts of 2-ethylhexyl acrylate,
A mixture consisting of 102 parts of 2-hydroxyethyl methacrylate, 305 parts of monomer (M-1), 30 parts of azobisisobutyronitrile, and 167 parts of toluene was
It was dripped over a period of time. Thereafter, 10 parts of azobisisobutyronitrile was added and kept at the same temperature for 10 hours to obtain a mixture with a nonvolatile content of 60%, a number average molecular weight of 6500, and 5 hydroxyl groups and 5 oxime blocked isocyanate groups per molecule. A solution of a vinyl copolymer was obtained (referred to as ()-1). (Note) Monomer (M-1) is a reaction product of 2,4-tolylene diisocyanate, methyl ethyl ketone oxime and 2-hydroxyethyl methacrylate, and has the following structure. Synthesis Example 6 In a reaction vessel similar to Synthesis Example 5, butyl acetate was added.
500 parts were charged and the temperature was raised to 80°C under a nitrogen atmosphere. Next, 350 parts of styrene, 50 parts of methyl methacrylate, 100 parts of butyl methacrylate, 93 parts of 2-ethylhexyl acrylate, 102 parts of 2-hydroxyethyl methacrylate, monomer (M-1)
A mixture of 305 parts of azobisisobutyronitrile, 30 parts of azobisisobutyronitrile, and 167 parts of butyl acetate was added dropwise over 3 hours. After that, 10 of azobisisobutyronitrile
The polymerization reaction was continued by adding an additional 1.0 parts and maintaining the same temperature for an additional 10 hours. Then 55.3 parts of 2-isocyanatoethyl acrylate and 0.1 parts of dibutyltin dilaurate
The non-volatile content was 61.3%, the number average molecular weight was 7500, the number of hydroxyl groups per molecule was 2.8, and there were 2.8 acryloyl groups and 5.5 hydroxyl groups. A solution of a vinyl copolymer having oxime blocked isocyanate groups was obtained (referred to as ()-1). Examples 1 to 4, Comparative Example 1 Paints were prepared by mixing each component (the amounts used are in parts) in the ratios shown in Table 1. Next, this paint was diluted with a mixed solvent of butyl acetate/xylene = 70/30 (weight ratio), sprayed onto a zinc phosphate treated steel plate, and baked at 140°C for 30 minutes to obtain a cured film with a film thickness of approximately 50μ. Ta. In this way, the performance etc. of the obtained coating film were evaluated first.
Shown in the table.

【table】

[Table] Example 5 After mixing each component (the amount used is in parts) in the ratio shown in Table 2, pour it into a casting mold,
A cured product without foaming was obtained by heating at 120°C for 3 hours. Comparative Example 2 After mixing each component (the amount used is in parts) in the ratio shown in Table 2, pouring into a casting mold,
Although the mixture was heated at 120°C for 3 hours, no molded product could be obtained due to foaming.

【table】

[Table] Examples 6 and 7 and Comparative Example 3 Paints were prepared and sprayed in the same manner as in Examples 1 to 4 and Comparative Example 1, except that the composition was changed to the one shown in Table 3. , and baked to obtain a cured coating. The performance etc. of the coating film thus obtained are shown in the same table.

[Table] As is clear from the above examples and comparative examples, the paint obtained using the thermosetting composition of the present invention has extremely low foaming properties compared to conventional products. , provides a coating film with good flexibility and impact resistance. Furthermore, the composition of the present invention can also be used as a cast product.

Claims (1)

[Claims] 1 () A compound having two or more isocyanate groups (a) blocked with an oxime compound, ()
A compound having two or more active hydrogen-containing groups (b), ()
Compounds having two or more acryloyl groups or methacryloyl groups (c); () Compounds having both functional groups: one or more of the above active hydrogen-containing groups (b) and one or more acryloyl groups or methacryloyl groups (c). , () A compound having both functional groups, an isocyanate group (a) blocked with one or more of the above-mentioned oxime compounds and one or more acryloyl or methacryloyl group (c), ()1
A compound having both functional groups consisting of an isocyanate group (a) blocked with one or more of the above-mentioned oxime compounds and one or more active hydrogen groups (b), and () each of the above-mentioned compounds blocked with an oxime compound. an isocyanate group (a) blocked with the above-mentioned oxime compound, which is a compound having one or more each of an isocyanate group (a), an active hydrogen-containing group (b), and an acryloyl group or methacryloyl group (c); Containing two or more compounds having two or more functional groups per molecule selected from the group consisting of an active hydrogen-containing group (b) and an acryloyl group or a methacryloyl group (c), and
The above-mentioned functional groups (a), (b) and (c) are all the above-mentioned compounds (), (), (), (), (),
A thermosetting composition characterized in that it is satisfied by () and/or ().