JPS6251969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-curable composition that cures in water and that adheres extremely strongly to a desired substrate surface, even in water or under wet conditions.

In fields such as civil engineering, architecture, and waterproofing, such as tunnel construction, floor lining, and wall protection, work conditions generally involve being wet with water or, in extreme cases, having to be painted or glued underwater. Therefore, there is a desire for an underwater curable composition that can be used even under such conditions.

Conventionally, this type of underwater curable composition is mainly referred to as an underwater curable composition. Generally used is an epoxy resin in which a polyamide resin synthesized by condensation of an aliphatic diamine having an aromatic structure (for example, xylene diamine) and a dimer acid is used as a curing agent.

However, this epoxy resin does not necessarily have sufficient adhesion to the substrate and cannot be said to be reliable, although this varies depending on the usage conditions. Furthermore, this epoxy resin has the drawback of being relatively expensive when used in fields such as civil engineering and architecture.

The present inventors have conducted various studies on compositions that can be cured in water, are inexpensive, can be cured not only on wet surfaces, but also in water, and can adhere extremely well to substrates. A composition consisting of 1) an unsaturated isocyanate, (2) a cement, and (3) an organic peroxide has been found to be effective and has already been proposed.

However, the unsaturated isocyanate used in this composition has a relatively high viscosity of several tens to hundreds of poise, which not only makes it difficult to handle, but also limits the amount of unsaturated isocyanate mixed in with cement (unsaturated isocyanate). (up to 200 parts by weight per 100 parts by weight), and the form of the composition may be limited to a putty-like form. Additionally, this composition has the disadvantage of short shelf life.

From this point of view, the present inventors further investigated and found that the above-mentioned drawbacks could be overcome by using unsaturated isocyanates and (meth)acrylic esters in combination, leading to the completion of the present invention. .

That is, the present invention provides (1) unsaturated isocyanate, (2)
This invention relates to a composition curable in water comprising (meth)acrylic esters, (3) cement, and (4) organic peroxide.

In the present invention, the effect of using (meth)acrylic acid esters in combination is extremely remarkable. In other words, (a) the viscosity and curing properties of the composition can be freely controlled, making it easy to handle; (b) the amount of cement mixed in increases, making it possible to
(c) The physical properties of the cured resin can be changed by changing the blending amount of the (meth)acrylic ester.

The unsaturated isocyanate used in the present invention has a (meth)acryloyl group in one molecule.
It has 0.1 equivalent or more, preferably 0.5 equivalent or more and 1.8 equivalent or less, and has an isocyanate group of 0.1 equivalent or more, preferably 0.5 equivalent or more and 1.8 equivalent or less.

When oligoacrylates containing no isocyanate groups are used, the curability and adhesion are not sufficient and it is not suitable.

Various types of unsaturated isocyanates are known, but from a practical standpoint, those synthesized by an addition reaction between an unsaturated monoalcohol containing a (meth)acryloyl group and a polyvalent isocyanate compound are used. It is preferable.

Examples of the polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, and diphenyl. Examples include methane diisocyanate, 1,5-naphthylene diisocyanate, paraphenylene diisocyanate, xylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and polyisocyanate synthesized from novolak.

Examples of unsaturated monoalcohols containing a (meth)acryloyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, trimethylolpropane acrylate, 2-
Examples include hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and trimethylolpropane dimethacrylate. The reaction ratio of the polyvalent isocyanate compound and the unsaturated monoalcohol containing the (meth)acryloyl group is 0.1 to 1 mole of the polyvalent isocyanate compound.
The amount is 1.9 mol, preferably within the range of 0.5 to 1.5 mol.

The synthesis of unsaturated isocyanates is carried out by adding monomers [(meth)acrylic acid esters] or polyvalent isocyanate compounds dissolved in a solvent as necessary.
It is convenient to carry out an addition reaction by dropping an unsaturated monoalcohol containing a (meth)acryloyl group, and in this case, it is advantageous to use a urethanization catalyst such as a tertiary amine or an organic compound of tin.

Examples of the (meth)acrylic acid esters used in the present invention include mono-, di-, and tri-methacrylates, and mono(meth)acrylates are useful from a practical standpoint including cost. However, it is extremely useful to use di- and tri-(meth)acrylates in combination when the number of (meth)acryloyl groups in the unsaturated isocyanate is small.

Specific examples of (meth)acrylic esters include methyl acrylate, ethyl acrylate,
Butyl acrylate, 2-ethylhexyacrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate,
Glycerin triacrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate, phenoxydiethyl methacrylate,
Examples include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyglycol dimethacrylate, 1,6-hexanediol dimethacrylate, and trimethylolpropane trimethacrylate. These (meth)acrylic esters can also be used in combination with vinyl ester resins, oligopolyester (meth)acrylates, and the like. The (meth)acrylic esters may be added in advance during the synthesis of the unsaturated isocyanate, or may be blended after the unsaturated isocyanate is synthesized.

The mixing ratio of unsaturated isocyanate and (meth)acrylic ester varies depending on the required viscosity and physical properties of the cured resin, but it is usually 20 to 95% by weight of unsaturated isocyanate and 5% of (meth)acrylic ester. -80% by weight, preferably 50-80% by weight of unsaturated isocyanates and 20-50% by weight of (meth)acrylates. If the mixing ratio of (meth)acrylic esters is less than 5% by weight, there is little point in adding it; if it is more than 80% by weight, the concentration of isocyanate decreases, resulting in impaired adhesion and slow curing.

The cement used in the present invention is necessary for accelerating hardening in water or under wet conditions, especially in water, and for developing hardness of the cured product, and cement is used in combination with unsaturated isocyanates and (meth)acrylic esters. Only then can reliable adhesion in water or under wet conditions be achieved.

As for cement, there is a type commonly available on the market called Portland cement.
Or alumina cement is sufficient, but white cement can also be used.

Cement may be used in combination with fillers that are known to react with cement, such as fly ash, fine silica powder, and the like.

The blending ratio of unsaturated isocyanate, (meth)acrylic ester and cement cannot be determined unconditionally as it varies depending on the purpose of use, but in general it is a mixture of unsaturated isocyanate and (meth)acrylic ester. It is appropriate to use 10 to 500 parts by weight, preferably 50 to 350 parts by weight, of cement per 100 parts by weight. If the blending amount of cement is less than 10 parts by weight, it will take a long time to remove water, and physical properties will not develop at an early stage. On the other hand, if the blending amount of cement is more than 500 parts by weight, it will be difficult to form a uniform putty, depending on the type of unsaturated isocyanate, and problems will arise in workability.

In the present invention, an organic peroxide is used for curing the unsaturated isocyanate, but if this is lacking, it will take a long time to develop the final hardness, and the practicality will be considerably impaired.

Examples of the organic peroxide used in the present invention include hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, 2,5-dichlorobenzoyl peroxide, etc. Examples include acyl peroxides such as methyl ethyl kent peroxide, cyclohexanone peroxide, methyl isobutyl ketone peroxide and the like.

These organic peroxides exhibit sufficient curing action even when used alone, but in order to further accelerate curing, organic peroxides, especially ketone peroxides and hydroperoxides, are recommended. When using these, it is preferable to use these together with a curing accelerator such as an organic acid salt of cobalt or acetylacetonate of vanadium. The amount of curing accelerator used is about 0.1 to 5 parts by weight per 100 parts by weight of unsaturated isocyanate.

The amount of the organic peroxide to be blended is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the unsaturated isocyanate. If the amount of organic peroxide is less than 0.1 part by weight, curing will not be sufficient and only a soft product will be obtained. On the other hand, if the amount of organic peroxide added is more than 10 parts by weight, no effect can be observed by increasing the amount, but rather disadvantages arise in that storage stability is shortened and costs are increased.

The water-curable composition of the present invention comprises unsaturated isocyanates, (meth)acrylic esters,
It is prepared by uniformly mixing cement and organic peroxide, and there is no particular restriction on the order of addition of each component. When an organic peroxide is used together with a curing accelerator, the curing accelerator may be blended with the unsaturated isocyanate in advance.

The underwater curable composition of the present invention may contain reinforcing materials, colorants, and other additives as necessary.

The composition of the present invention can be applied to a substrate in water or under wet conditions by lining, spraying or roll coating, casting, puttying, etc., but it goes without saying that the composition should not be wetted with water. It can also be applied to a substrate, that is, a dry substrate, by the same means as described above, and then cured while immersed in water.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Synthesis of unsaturated isocyanate (A) Tolylene diisocyanate mixture (2.4 bodies, 80% by weight, 2.6
20% by weight of body), 220 g of methyl methacrylate, 0.8 g of dibutyltin dilaurate, and 0.1 g of parabenzoquinone were added, and while stirring,
-Hydroxypropyl methacrylate 432g (3
mol) was added dropwise.

Immediately after the start of dripping, the temperature begins to rise, and when it reaches 60℃, it is cooled down, and then the temperature is kept at 60℃ until the dripping is finished.
℃ was maintained.

After the dropwise addition was completed, the reaction was continued for 1 hour, and as a result of infrared analysis, it was determined that the free hydroxyl groups had disappeared. In addition, it is recognized that the isocyanate group has decreased to about 1/4 of the original amount, and the following (a),
(b) Possible mixtures of unsaturated isocyanates (A)
A methyl methacrylate solution (methyl methacrylate content of about 22% by weight) was obtained. The product was pale yellowish brown in color and had a viscosity of 2.9 poise.

Add 300 parts by weight of Portland cement and parts by weight of cobalt naphthenate to 100 parts by weight of a methyl methacrylate solution of unsaturated isocyanate (A), mix well to form a paste, and then add 3 parts by weight of cumene hydroperoxide. It was further kneaded.

The resulting composition was immersed in 3% saline solution for 150 mm.
Edge of a steel plate measuring 25mm x 3mm with some rust
Putty was applied to 12mm to a thickness of 3 to 5mm.

To this, 150 mm of water similarly immersed in 3% saline solution was added.
A test piece was created by gluing and pressing 12mm × 25mm × 3mm polished steel plates, and the test piece was left to harden in water.

The pot life of the composition in air is approximately 24 hours.
The pot life in water was about 3 hours.

The test piece in water hardens after 5 hours and becomes 1
After being left overnight, it became hard and it was impossible to peel it off from the steel plate without damaging the cured product.

Also, the tensile shear strength of steel plate to steel plate is 91 to 147
Kg/cm ² , and the composition of the present invention exhibited sufficient performance as an adhesive.

Example 2 Synthesis of unsaturated isocyanate (B) 333 g (1.5 mol) of isophorone diisocyanate, 155 g of phenoxyethyl acrylate, Weigh out 0.6 g of dibutyltin dilaurate and 0.1 g of parabenzoquinone, and add 2-hydroxyethyl methacrylate to this.
312 g (2.4 mol) was added dropwise.

After the dropwise addition, the temperature gradually rose, so it was cooled when it reached 60°C. After heating and stirring at 60° C. for 3 hours, infrared analysis revealed that free hydroxyl groups disappeared and isocyanate groups remained.

The obtained phenoxyethyl acrylate solution of unsaturated isocyanate (B) (phenoxyethyl acrylate content: about 20% by weight) was pale yellow in color and had a viscosity of 4.7 poise.

100 parts by weight of phenoxyethyl acrylate solution of unsaturated isocyanate (B), 150 parts by weight of white cement, 3 parts by weight of paramethane hydroperoxide, 10% acidic butyl phosphate solution of vanadium acetylacetonate (2.4% vanadium )of
0.3 parts by weight were mixed.

The resulting composition was immersed in water for 150 mm.
After adhering it to the 12mm end of a slate board of ×25mm ×6mm, press and tighten another slate board of the same size.
It was left in water for 24 hours. After taking it out and drying it at room temperature for a day and night, we measured the adhesive strength, and found that the slate plate broke at around 30 kg/cm ² , making further measurements impossible, and the strength of the bonded portion exceeded that of the slate.

Example 3 Synthesis of unsaturated isocyanate (C) 250 g (1 mol) of diphenylmethane diisocyanate and triethylene glycol dimethacrylate were placed in a separable flask equipped with a stirrer, a dropping funnel, a thermometer, and a reflux condenser. 150g,
Dibutyltin dilaurate 0.6g, benzoquinone
0.06 g was added, and 220 g (equivalent to 0.8 mol) of trimethylolpropane diacrylate (including small amounts of mono- and triacrylate) was added dropwise.

As the temperature rose as the dripping took place, the temperature reached 60°C.
It was cooled when the temperature reached 60°C, and the temperature was maintained at 60°C until the dropwise addition was completed.

After reacting at 60°C for 3 hours, it was determined that free hydroxyl groups had disappeared as a result of infrared analysis, and triethylene glycol dimethacrylate welding of unsaturated isocyanate (C) (triethylene glycol dimethacrylate content approximately 24% by weight) was performed. ) was obtained with a light reddish brown color and a viscosity of 9.5 poise.

Add 250 parts by weight of alumina cement and 2 parts by weight of benzoyl peroxide paste (50% benzoyl peroxide) to 100 parts by weight of a triethylene glycol dimethacrylate solution of unsaturated isocyanate (C) and knead to form a putty. A composition was obtained.

The resulting composition was puttyed over the entire surface of a bent steel plate (character shape, height 5 cm, width 10 cm) that was wet with water, and then immediately poured into a factory drain (the water flow rate was approx.
10m/min).

When the putty on the bent steel plate was observed after being left in a factory drainage outlet overnight, no putty flowed out and the putty had hardened considerably. Adhesion between the steel plate and the putty was also good. Furthermore, the surface was polished to a smooth surface, and it showed a value of 50 kg/cm ² or more in an elcometer test.

Claims (1)

[Claims] 1 (1) unsaturated isocyanate, (2) (meth)acrylic esters, (3) cement, and (4) Organic peroxide A water-curable composition consisting of: