JPS6361331B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a curable composition useful mainly in the fields of adhesives and paints, which particularly has excellent adhesion to substrates and which can be freely curable. RELATED TO CONTROLLABLE COMPOSITIONS.

[Prior art]

A wide variety of adhesives and paints have already appeared, each aimed at different uses. As is well known, epoxy resin is the most well-established adhesive and has a good track record, but on the other hand, the hardening agent is irritating to the skin, and it is difficult to control room temperature curing. In addition, it takes a long time to cure, and if it cures quickly, the adhesion is inevitably impaired, and it is difficult to achieve the original physical properties.

In addition, neither polyurethane adhesives nor hardening acrylic adhesives fully meet the requirements.

In particular, it is used as an adhesive for materials that are commonly found in everyday life, such as concrete surfaces that contain water or steel surfaces that have some rust on them, where the physical properties of existing adhesives do not provide reliable results. There are many. The gluing operation originally cleans the bonding surface,
It is natural to choose conditions that allow the adhesive used to exhibit its best performance, and if this can be achieved there will be few problems, but from a practical standpoint, especially when bonding is performed outdoors, it is important to choose the best conditions. It is difficult to find, and in many cases almost impossible.

The situation is similar in the case of paints. There are many uses for paints that require applying a highly adhesive rust-preventing paint after removing one or two types of rust.

Conventionally, oil-based or alkyd-based paints mixed with lead oxide-based rust-preventing pigments have been used in cases like this, but maintenance-free heavy-duty anti-corrosion paints retain their performance for many years once applied. It is difficult to use alkyd-based paints.

[Structure of the invention]

The present inventors have conducted various studies on resins that serve as bases for adhesives and paints that exhibit extremely stable performance even under fluctuations in external conditions. As a result, a composition having the following structure has been found to have performance close to the above performance. Based on this knowledge, the present invention was completed. That is, the present invention provides (A) the following (a) to (c): (i) a side obtained by reacting a vinyl polymer having an acid anhydride structure with an alcohol having a (meth)acryloyl group; Polymers having (meth)acryloyl groups in their chains, (b) Vinyl polymers having carboxyl groups in their structure, with (meth)acryloyl groups in their side chains obtained by reacting epoxy compounds having (meth)acryloyl groups. (c) A polymer having (meth)acryloyl in the side chain obtained by reacting a vinyl polymer having a hydroxyl group in its structure with an unsaturated isocyanate compound containing an isocyanate group and a (meth)acryloyl group in the molecule. A polymer having a (meth)acryloyl group in any side chain of the polymer having a group, and (B) a polyvalent isocyanate compound and an unsaturated alcohol containing a (meth)acryloyl group per mole of the polyvalent isocyanate. Contains an unsaturated isocyanate having 0.1 equivalent or more of isocyanate group and 0.1 equivalent or more of (meth)acryloyl group in one molecule, obtained by reacting with a group-containing unsaturated alcohol at a molar ratio of 0.1 mol to 1.9 mol. The present invention relates to a curable composition characterized in that:

In this specification, "having a (meth)acryloyl group"
is understood to mean "contains a methacryloyl group, an acryloyl group, or both."

The combination of (A) and (B) above is, so to speak, a necessary condition for the composition of the present invention, but the use of other monomers such as acrylic esters can also be said to be a sufficient condition and is practically advantageous. be.

In addition, an organic peroxide must be used as a curing agent, and in particular, an accelerator must be used for curing at room temperature.

The polymer having a (meth)acryloyl group in the side chain used as component (A) in the composition of the present invention includes the following polymerizable monomer 1 and a functional group for introducing a (meth)acryloyl group into the monomer (for example, an acid anhydride group,
A polymerizable monomer (ii) having a carboxylic acid group, a hydroxyl group) and a polymerizable double bond, a group (for example, a hydroxyl group, an epoxy group, an NCO group) that is reactive with the functional group of the monomer (ii), and ( meth)acryloyl group and a compound (iii) having a meth)acryloyl group.

The monomer (i) that forms part of the polymer main chain does not need to be particularly limited, but includes, for example, styrene,
Typical examples include vinyltoluene, chlorostyrene, acrylic esters, methacrylic esters, acrylonitrile, vinyl chloride, vinylidene chloride, vinylpyrrolidone, and vinyl acetate.

The monomer (ii) that forms a part of the polymer main chain and has a functional group for introducing a side chain (meth)acryloyl group into the main chain includes, for example, acrylic acid, methacrylic acid;
Maleic anhydride, itaconic anhydride: unsaturated alcohols such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-
Hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; methylol acrylamide.

Compound (iii) that introduces a (meth)acryloyl group into a side chain into a polymer is an unsaturated compound described in (ii) above that reacts with an acid anhydride group in the polymer to introduce a (meth)acryloyl group into a side chain. Alcohols, such as unsaturated epoxy compounds that react with side chain carboxyl groups of polymers to introduce (meth)acryloyl groups, such as glycidyl (meth)acrylate;
In particular unsaturated isocyanates which react with glycidyl methacrylate or e.g. side chain OH groups of polymers [hereinafter this unsaturated isocyanate will be referred to as unsaturated isocyanate (C) to distinguish it from the unsaturated isocyanate of component (B) of the invention. ]. The unsaturated isocyanate (C) can be obtained by reacting the unsaturated alcohol having a (meth)acryloyl group described in monomer (ii) with a polyhydric isocyanate. In this case, it is necessary to react one mole or more of unsaturated alcohol per mole of polyvalent isocyanate. For example, it is necessary to react in a range of 1.1 to 1.8 moles of unsaturated alcohol per mole of diisocyanate to leave an NCO group, and this residual NCO group is the result of the reaction with monomers (i) and (ii). Used for reaction with hydroxyl groups in polymer main chain.

Therefore, the unsaturated isocyanate (C) is, for example, a mixture of the following two types of monomers.

In this case, the reaction with the polymer obtained from monomers (i) and (ii) having hydroxyl groups in the side chains is only with the unsaturated isocyanate (C) of (a), but with the di(meth)acryloyl of (b). Urethanes having groups are useful for improving physical properties including improving curability. If a free polyvalent isocyanate compound remains in the unsaturated isocyanate (C), it will cause gelation during the reaction, so the molar ratio of the unsaturated alcohol should be greater than 1 mole per mole of the alcohol.

Examples of polyvalent isocyanates that can be used as the (meth)acryloyl group-containing unsaturated isocyanate (C) for introducing (meth)acryloyl groups into the side chains of the polymer of the present invention include the following types: 2,4- Tolylene diisocyanate, 2,4-
Mixture of tolylene diisocyanate and 2,6-tolylene diisocyanate, paraphenylene diisocyanate, diphenylmethane isocyanate,
Polyisocyanate synthesized from xylylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, novolak, and 1,5-naphthylene diisocyanate.

Thus, in the composition of the present invention, the polymer (A) having a (meth)acryloyl group in the side chain can be produced, for example, as follows: (a) A polymer having an acid anhydride structure in its structure,
Reacting an alcohol with a (meth)acryloyl group: (b) Reacting an epoxy compound having a (meth)acryloyl group with a polymer having a carboxyl group in its structure: (c) Reacting a polymer having a hydroxyl group in its structure with an unsaturated isocyanate compound containing an isocyanate group and a (meth)acryloyl group in the molecule: Among the polymers in the above examples, (c) is an unsaturated isocyanate in the polymer having a hydroxyl group.
Most preferred is a polymer (A) obtained by reacting (C) with a (meth)acryloyl group in the polymer side chain via a urethane bond. In the type (B) in which an unsaturated epoxy compound is reacted with a carboxyl group-containing polymer, the hydroxyl group generated by the reaction reacts with the unsaturated isocyanate (B), so the polymer (A) and unsaturated isocyanate (B) are separated immediately before use. However, if the two are mixed together, they cannot be stored for a long time.

Unsaturated isocyanates which are other components of the present invention
(B) has a slightly different component ratio from unsaturated isocyanate (C). That is, the molar ratio of the polyvalent isocyanate compound and the (meth)acryloyl group-containing unsaturated alcohol is of the type obtained by reacting 0.1 to 1.9 moles of the unsaturated alcohol per mole of the polyvalent isocyanate. Therefore, the unsaturated isocyanate (B) used as a monomer component is, for example, a mixture of the following three components: However, depending on the molar ratio of the unsaturated alcohol and the isocyanate compound in the unsaturated alcohol (B), there may be two components.

The constituent components of the unsaturated isocyanate (B) are the same as those of the unsaturated isocyanate (C).

It goes without saying that the blending ratio of the polymer (A) of the present invention, that is, the side chain unsaturated bond type polymer, and the unsaturated isocyanate (B) can be changed depending on the purpose of use, but generally the unsaturated isocyanate (B) is completely It can be used from 5 to 95% by weight of the composition. A suitable proportion of the unsaturated isocyanate (B) is in the range of 20 to 70% by weight of the total composition. Although it is of course possible to use the polymer (A) and the unsaturated isocyanate (B) by dissolving them in a solvent, it is practically preferable to dissolve them in a monomer. The monomers used here can be used as long as they are copolymerizable with (meth)acryloyl groups, such as styrene, vinyltoluene, methacrylic esters, acrylic esters, acrylonitrile, vinylpyrrolidone, and vinyl acetate. Examples include.

Further, in order to cure the composition of the present invention, a curing agent is used, and for curing at room temperature or by heating, an organic peroxide and an accelerator as necessary are used, and for photocuring, a photosensitizer such as benzyl is used. Dimethyl ketal, hydroxyacetophenone, benzoisoisobutyl ether, etc. are used.

The composition of the present invention may optionally contain a fibrous reinforcing material,
Fillers, coloring agents, etc. can be used together.

[Embodiments of the invention]

Examples are provided below to aid in understanding the invention.

Example 1 Synthesis of side chain unsaturated bond polymer A 300 g of ethyl acetate and 1 g of azobisisobutyronitrile were placed in a four-necked flask equipped with a stirrer, a thermometer with a gas introduction hole, a reflux condenser, and a separating funnel. , 0.2g of lauryl mercabutane is added,
170 g of butyl acrylate at a temperature of 70°C in a nitrogen stream,
A monomer mixture of 20 g of acrylonitrile and 10 g of 2-hydroxypropyl methacrylate is added dropwise.

After completing the dropwise addition, keep the mixture under reflux for 12 hours. temperature 60
The temperature was lowered to °C and 0.1 g of hydroquinone was added to terminate the reaction.

2-hydroxypropyl methacrylate 1
Mol and 1 of 2,4-tolylene diisocyanate:
Adding 3 g of unsaturated isocyanate () with 1 mole of reaction product, substantially zero hydroxyl value, and remaining substantially 1 equivalent of isocyanate groups;
Heat and stir at 60°C for 3 hours.

Infrared analysis confirmed that the hydroxyl groups had almost completely disappeared. Further, 200 g of ethyl acetate was added, and unsaturated polymer (A) was obtained in the form of a slightly cloudy light yellowish brown liquid.

An adhesive was manufactured with the following formulation.

Unsaturated polymer (A) 100 parts Unsaturated isocyanate () 30 parts 1 part benzoyl peroxide paste (50% BPO) Glass flakes (average particle size approx. 80μ) 40 parts This pot life lasted about 30 minutes.

The end of a 150mm x 25mm x 3mm steel plate was polished to a length of 13mm with +600 abrasive paper, and coated with a bar coater to a thickness of 0.2mm on a test piece that had been cleaned with 1,1,1, trichloroethane, and kept at room temperature. After leaving it for 20 minutes to volatilize the ethyl acetate, it was crimped and left overnight.

The adhesive strength by tensile shear reached 154-192 Kg/cm ² and was useful as an adhesive. Furthermore, even when using a rusted test piece of the same size (however, the loose rust was removed with sandpaper), this adhesive exhibited a shear bond strength of approximately 140 to 170 kg/cm ² , showing the same adhesive strength. It was at a standard level.

Example 2 Synthesis of side chain unsaturated condensation polymer (B) In a four-necked flask equipped with a stirrer, reflux condenser, thermometer with gas inlet hole, and dropping funnel, 200 g of methyl ethyl ketone and 0.8 g of azobisitubutyronitrile were placed. g, and 0.2 g of lauryl mercaptan, and while refluxing toluene under a nitrogen atmosphere, a mixed solvent of 160 g of nonyl acrylate, 20 g of sterene, and 20 g of maleic anhydride was added dropwise. After the addition is complete,
Reflux was continued for 16 hours, the temperature was lowered to 60°C, and 0.08 g of hydroquinone was added to stop the reaction.

Then 2-hydroxyethyl methacrylate 30
g and 0.6 g of dibutyltin oxide were added, and the mixture was further heated at the boiling point of toluene for 8 hours.

The acetic acid value (in terms of solid content) was 59.5, indicating that most of the acid anhydride groups were converted to monoesters of unsaturated alcohols. After cooling to room temperature, add 300g of methyl ethyl ketone to form a side chain unsaturated bond type resin.
(B) was obtained as a pale yellowish brown liquid.

Synthesis of unsaturated isocyanate () Into a separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer with a gas inlet hole, 222 g (1 mol) of isophorone diisocyanate, 0.05 g of rosebenzoquinone, and 0.3 g of dibutyltin dilaurate were added. 146 g (1.2 mol) of 2-hydroxyethyl methacrylate was added dropwise.

The temperature will rise as the mixture is added, so once it reaches 60°C, cool it down and react at 60°C for 3 hours in dry air.
As a result of infrared analysis, it was determined that the absorption of hydroxyl groups had almost completely disappeared, although it was difficult to judge, and unsaturated isocyanate () was obtained in the form of a pale yellowish brown liquid.

Side chain unsaturated bond type polymer (B) 100 parts unsaturated isocyanate () 30 parts para-menthane peroxide 1 part dimethyl para-toluidine A mixture of 0.5 parts was applied to the edge of the same steel plate as in Example 1 by 0.2 mm.
Paint so that it is thick.

After the solvent evaporates, the coating film is sticky, but when the steel plates are stacked together, they become glued and do not move after about an hour, and after being left overnight, the adhesive strength by tensile shear is 134 to 191 kg/cm ² and could be used as an adhesive.

In addition, when using a test piece of the same size with a film of water on it after wetting the steel plate and scraping off the excess water, it showed an adhesive strength of 150 to 200 kg.
Rather, an improvement in strength was observed.

Example 3 Synthesis of side chain unsaturated bond type polymer (C) 200 g of methyl ethyl ketone and 142 g of glycidyl methacrylate were placed in a separable flask equipped with a stirrer, reflux condenser, dropping funnel, and gas introduction tube.
g, 300 g of ethyl acrylate, 4 g of azobisisobutyronitrile, and 1 g of lauryl mercabutane were polymerized for 8 hours at the boiling point of methyl ethyl ketone in a nitrogen gas stream, then the temperature was lowered to 60°C, and 0.2 g of hydroquinone was added to terminate the reaction. .

Next, triphenylphosphine 2g, acrylic acid
30 g was added, the temperature was raised, and the reaction was carried out for 12 hours at the boiling point of methyl ethyl ketone under a nitrogen stream. The acid value became almost zero, and the reaction was judged to have been completed.

370 g of phenoxyethyl acrylate was added thereto, the reflux condenser was replaced with a fractionation condenser, and methyl ethyl ketone was distilled off under reduced pressure of about 500 mmHg, to obtain an unsaturated bond type polymer (C) in the form of horizontal brown syrup.

Synthesis of unsaturated isocyanate () 1,6-hexamethylene diisocyanate was placed in a separable franc equipped with a stirrer, a dropping funnel, a reflux condenser, and a thermometer with a gas introduction hole.
164 g (1 mole), phenoxyethyl methacrylate 166 g, dibutyltin dilaurate 2 g, and hydroquinone 0.2 g were charged, the temperature was raised to 60°C, and then 80 g (0.8 mole) of 2-hydroxyethyl acrylate was added dropwise.

During dropping, the solution should be cooled and kept at around 60°C.

After the dropwise addition, the mixture was heated and stirred at 60°C for 3 hours, and as a result of infrared analysis, it was determined that the hydroxyl groups had completely disappeared, and unsaturated isocyanate () was obtained in the form of a pale yellowish brown liquid.

Side chain unsaturated bond type polymer (C) 100 parts Unsaturated isocyanate 100 parts Irgakiure #651 manufactured by Ciba (trade name, photosensitizer)
Mix 4 parts and immediately make a 25mm wide, 150mm long, 3mm thick
After polishing #320, it was applied to a length of 100mm using a knife coater on a steel plate that had been cleaned with triclean, and a polyester film of the same size (thickness 125μ) was crimped.
10m/20cm below the UV irradiation device with an output of 30Kw
Pass and cure at a speed of 1 minute. After curing, it was allowed to stand overnight and a T-peel test was performed, which showed a peel strength of 2 kg/cm or more, indicating that it could be used as an adhesive.

Example 4 A photocurable resin having the same composition as that used in Example 3 was coated on a 150 mm x 100 mm x 1 mm bonderite treated steel plate to a thickness of 25 μm using a bar coater, and placed 20 cm under an ultraviolet irradiation device with an output of 30 Kw. 5m/
Passed it in minutes.

The hardness of the resulting coating film was 2 to 3H, the cross-cut test was 100/100, and it had excellent adhesion, and no cracking or peeling of the coating film was observed even in a 180° bending test of 5 mm diameter.

Example 5 Synthesis of side chain unsaturated bond type resin (D) 104 g of styrene, 100 g of methyl methacrylate, 104 g of styrene, 100 g of methyl methacrylate,
65 g of 2-hydroxyethyl methacrylate, 131 g of ethyl acetate, 1 g of lauryl mercaptan, and 1 g of azobisisobutyronitrile were charged, heated in a nitrogen gas stream, and reacted for 16 hours under reflux of ethyl acetate.

After finishing, add 0.1g of hydroquinone. Separately, 250 g (1 mol) of diphenylmethane diisocyanate
and 2-hydroxyethyl methacrylate 156g
(1.2 mol) was heated to 60°C for 6 hours in the absence of a catalyst.The disappearance of hydroxyl groups was confirmed by infrared analysis. 120g of unsaturated isocyanate () and 1g of dibutyltin dilaurate were added, and the mixture was heated for 6 hours under a stream of dry air. After reacting at °C for 3 hours, it was confirmed by infrared analysis that the free isocyanate groups had completely disappeared.

Add 330 g of styrene and distill off ethyl acetate at about 450 mmHg.

A side chain unsaturated bond type resin (D) of styrene solution was obtained as a pale yellowish brown liquid.

Side chain unsaturated bond type resin (D) 100 parts Unsaturated isocyanate () 50 parts Styrene 20 parts Cumene hydroperoxide 3 parts Cobalt naphthenate 2 parts Talc 200 parts were uniformly kneaded and immediately wetted with water to a 150mm
Apply to the 13mm edge of a slate board of ×25mm ×6mm,
I crimped it on and left it overnight.

30Kg/cm ² in adhesive strength test using tensile shear
As a result, the slate broke.

Separately, the hardness of a 150 mm x 100 mm x 3 mm wet steel plate with putty applied to a thickness of 3 mm and hardened is 3.
~4H, in a tensile adhesion test using an elcometer, failure occurred on the dolly surface (epoxy resin adhesive surface) at 80 kg/cm ² or more.

However, for samples with the same formulation except for the unsaturated isocyanate (2), the peeling was in the range of 30 to 50 kg/cm ² and peeling occurred between the steel plate surface and the cured resin.

〔Effect of the invention〕

It exhibits strong adhesion even when applied to rusted or water-wet materials.

Claims (1)

[Scope of Claims] 1 (A) The following (a) to (c): (a) Obtained by reacting a vinyl polymer having an acid anhydride structure in its structure with an alcohol having a (meth)acryloyl group. (b) Polymers having (meth)acryloyl groups in the side chains obtained by reacting vinyl polymers having carboxyl groups in the structure with epoxy compounds having (meth)acryloyl groups. Polymer having (meth) groups; ) A polymer having a (meth)acryloyl group in any side chain of the polymer having an acryloyl group, and (B) a polyvalent isocyanate compound and an unsaturated alcohol containing a (meth)acryloyl group per mole of polyvalent isocyanate (meth). ) An unsaturated isocyanate having 0.1 equivalent or more of an isocyanate group and 0.1 equivalent or more of a (meth)acryloyl group in one molecule, obtained by reacting with an acryloyl group-containing unsaturated alcohol at a molar ratio of 0.1 mol to 1.9 mol. A curable composition comprising: