JPH06102771B2 - Antifouling paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antifouling coating composition.

In particular, the present invention utilizes the properties of a curable resin having excellent weather resistance and low surface energy and migration of free silicone resin, and exhibits excellent effects in releasability and antifouling property. It relates to a composition.

[Conventional technology and problems]

It is known to mix a curable silicone resin, mainly a rubber silicone resin, with a liquid having a releasing action such as silicone oil to form a coating having an antifouling effect particularly in seawater.

The same is said for thermoplastic type silicone resins. For example, JP-A No. 60-65076 discloses a reaction-curable silicone composition, JP-A No. 62-156172 discloses a polymer of vinyl silicon, and JP-A No. 62-275132 discloses a polysiloxane macromer. Copolymers with vinyl monomers are disclosed.

However, existing coatings based on these silicone resins are easily peeled off because of poor adhesion to the substrate under conditions of constant exposure to waves, such as when immersed in seawater. It is difficult to maintain the antifouling effect for a long period of time.

The present invention eliminates these conventional drawbacks, forms a low energy surface to exhibit an antifouling effect, has good adhesion to the substrate, and can withstand repeated stress such as waves sufficiently, and is practically used. The present invention relates to a coating composition that is difficult to peel off.

[Means for Solving the Problems]

That is, the present invention provides the following (A), (B) and (C)
The present invention provides an antifouling coating composition containing components: (A) Unsaturated isocyanate in a silicone resin having at least one active hydrogen in one molecule and having a main chain of constituent molecules of a polysiloxane structure. A graft polymer obtained by reacting a nato to convert it into a silicone resin having at least a portion having an unsaturated bond, and then adding a monomer having active hydrogen and a copolymerizable monomer, if necessary, and polymerizing the same. (B) a polyvalent isocyanate compound; and (C) a silicone resin in which the main chains of constituent molecules are polysiloxane bonds.

Thus, by finally curing the coating material containing the free silicone resin, the coating film has both durability and adhesiveness, and at the same time, due to the appropriate migration of the silicone resin from the cured coating film, in water. It exerts the effect of preventing the adhesion of shellfish and algae.

The final cured resin according to the present invention comprises: (i) ratio of unsaturated silicone resin (ii) amount of monomer having active hydrogen (iii) type of monomer (iv) type and amount of polyvalent isocyanate (v) of saturated silicone resin The physical properties can be changed over a wide range depending on the type and amount, and it can be used in various fields.

The coating composition according to the present invention has excellent adhesion to metals such as iron and aluminum, concrete, inorganic building materials including slate, wood, etc., and by curing this, a tough and durable coating film. Can be obtained.

In order to facilitate the understanding of the present invention, (A) of the composition of the present invention
The procedure for making the components is illustrated below.

In the above formula, styrene is used as the vinyl monomer and 2-hydroxyethyl methacrylate is used as the monomer having active hydrogen.

The raw materials used for producing the component (A) of the composition of the present invention are classified into the following types.

(A) Silicon resin having active hydrogen, (b) unsaturated isocyanate, (c) monomer having active hydrogen, and optionally (d) copolymerizable monomer.

In the silicone resin (a) used for producing the component (A) of the composition of the present invention, the main chain of the constituent molecules has the following formula (Wherein R and R'are alkyl groups and phenyl groups) and has a polysiloxane structure, and at least one active hydrogen capable of reacting with an isocyanate, typically a hydroxyl group, should be possessed in one molecule. is necessary.

As such a silicone resin, dimethylpolysiloxane having a hydroxyl group at the terminal is suitable, and examples of commercially available products include the following types manufactured by Shin-Etsu Chemical Co., Ltd.

X-22-160A Hydroxyl number 62 Molecular weight 1800 X-22-160B Hydroxyl number 35 Molecular weight 3200 X-22-160C Hydroxyl number 20 Molecular weight 5600 For introducing unsaturated bond into these hydroxyl group-containing silicone resins. Examples of the unsaturated isocyanate (b) include a) a compound that shares an unsaturated bond with an isocyanate group in one molecule, b) an adduct of diisocyanate with an unsaturated monoalcohol of 1 mol to 1 mol, and the like. Can be given.

Examples of unsaturated isocyanates include, for example, isocyanate ethyl methacrylate, methacryloyl isocyanate, m-isopropenyl-α, α dimethylbenzyl isocyanate, generally isocyanate ethyl methacrylate (the following formula) Is preferable from the viewpoints of handleability and reactivity of isocyanate.

The reaction product of diisocyanate and unsaturated alcohol is, for example, an adduct of 2,4-tolylene diisocyanate and 2-hydroxyethyl methacrylate in an amount of 1 mol to 1 mol (the following formula).

In this case, as the diisocyanate, types such as 2,4-tolylene diisocyanate and isophorodiisocyanate having different reactivity of two isocyanate groups are advantageous.

The reaction ratio between the active hydrogen of the silicone resin and the unsaturated isocyanate is 0.01 part or more and 10 parts or less, preferably 0.1 part or more and 3 parts, with respect to 100 parts (parts by weight, the same below) of the silicone resin. It is the following. In this case, it is not necessary to react all the active hydrogen present. The degree depends on the types of monomers used together and the ratio of the unsaturated silicone resin to the monomers.

Examples of the monomer (c) having active hydrogen include 2-
Examples thereof include hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and phenoxyethyl methacrylate.

The monomer used in combination as the copolymerizable monomer (d) may be any monomer as long as it can be copolymerized therewith, and generally commercially available types are used. There are no particular restrictions on the type,
Examples thereof include styrene, vinyltoluene, acrylic acid esters, methacrylic acid esters, acrylonitrile, methacrylonitrile, vinyl acetate, ethylene and butadiene.

The mixing ratio of the unsaturated bond-introduced silicone resin and the monomer can be freely changed, but depending on the amount and type of the monomer,
There is a possibility that the compatibility with the silicone resin as the component (B), migration, antifouling action, weather resistance, etc. may be insufficient.

If these are taken into consideration, the proportion of unsaturated bond-introduced silicone resin is 10 to 95% (wt%, the same applies hereinafter), preferably
20-96%.

The use ratio of the monomer (c) having active hydrogen is preferably about 1 to 30 mol% when the total amount of the monomer is 100, and the balance is a copolymerizable monomer (d).

Added to the graft polymer (A) having active hydrogen,
Examples of the polyvalent isocyanate compound (B) for reacting with this to cure the resin include the following types.

2,4-Tolylene diisocyanate, 2,6-Tolylene diisocyanate, Mixture of 2,4-Tolylene diisocyanate and 2,6-Tolylene diisocyanate, Diphenylmethane diisocyanate, Isophorone diisocyanate, Xylylene diisocyanate , Hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, 1,5 naphthylene diisocyanate, and polyisocyanates represented by the following general formula.

Adducts of these isocyanates with, for example, polyols, in which isocyanate groups remain, can be used as well.

Further, the combined use of a so-called urethane-forming catalyst in the reaction between the isocyanate compound and the active hydrogen of the polymer is effective in demonstrating the physical properties of the coating film at an early stage.

The silicone resin in which the main chain of the constituent molecule is a polysiloxane bond, which is the component (C) of the composition of the present invention, is represented by the following general formula.

(However, R ₁ and R ₂ are an alkyl group or an aryl group) This silicone resin does not have active hydrogen, and is desirably a viscous liquid or grease at room temperature. Stokes (CS) or higher, preferably
1,000 to 100,000 CS.

The mixing ratio of each component of the composition of the present invention varies depending on the purpose of use, but it is the unsaturated graft polymer which is the component (A).
0.1 parts (B) polyisocyanate compound per 100 parts by weight
To 30 parts by weight, preferably 1 to 20 parts by weight, more preferably 2 to 10 parts by weight, and the silicone resin as the component (C) is a saturated silicone resin of 5 to 150 parts, preferably 10 to 100 parts by weight or less. is there. If the proportion of saturated silicone resin used is large, the coating becomes soft and the role of the protective coating is impaired, and if it is small, the meaning of addition is lost. Covered with silicone resin, the effect of preventing the adhesion of marine organisms is quickly lost.

Needless to say, a reinforcing material, a filler, a coloring agent, a wax and the like can be used in combination for curing the silicone resin graft unsaturated polymer according to the present invention, if necessary.

Next, the present invention will be further described with reference to examples.

Examples 1 to 5 In a two-separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas introduction tube, a silicone resin having a hydroxyl group (X-22-160B manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl number about 35, molecular weight) 3200) 200 parts (weight part, the same applies hereinafter), isocyanate ethyl methacrylate 0.8 part,
Dibutyltin dilaurate (0.2 parts) was charged and reacted at 60 to 65 ° C for 4 hours. As a result of infrared analysis, it was confirmed that free isocyanate and the like had disappeared.

40 parts of 2-hydroxypropyl methacrylate,
Charge 177 parts of styrene, 300 parts of toluene, 4 parts of azobisisobutyronitrile, 2 parts of tert-butyldodecanethiol and add 2 parts of azobisisobutyronitrile on the way at 75-80 ° C for 16 hours. After polymerization, 0.1 part of hydroquinone monomethyl ether was added. A slightly viscous and cloudy solution of the homogeneous graft polymer of the component (A) was obtained.

Polymerization of dimethylpolysiloxane as a silicone resin of the component (C) was performed by adding 7 parts of isophorone diisocyanate as the component (B) and 0.3 part of dibutyltin dilaurate to 100 parts of the solution of the polymer of the component (A). Using a homologue (KF96 series manufactured by Shin-Etsu Chemical Co., Ltd.), 50 parts each was added to 100 parts of the unsaturated polymer (A). The viscosity of the silicone resin used in each example is as follows.

Example 1 10CS 2 100CS 3 3000CS 4 30,000CS 5 300,000CS 30 mm x 20 cm thick 5 mm slate plate was coated with Splaydam T-300F manufactured by Showa Polymer Co., Ltd. at 1.5 mm pressure and cured. On the coating film thus formed, (A) as described above,
The coating composition in which the components (B) and (C) were mixed was applied with a bar coater to a thickness of about 200μ. After leaving the one liquid as it was, it was heated at 100 ° C. for 1 hour to be cured.

Separately, in the case of only the slate plate, a hard polyvinyl chloride plate having the same size and a thickness of 3 mm was immersed in seawater from April to October as a comparative example. The results are shown in Table 1.

As can be seen from Table 1, silicone resin has a viscosity of 3000-
It is clear that the addition effect is best when using the one around 30,000SC.

It is presumed that this is because the silicone resin migrates from the cured resin coating film at an appropriate rate and thus has the effect of permanently excluding the adhesion of shellfish and algae.

Comparative Example The same as Example 1 except that a silicone resin having active hydrogen (manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-160B was used in place of the silicone resin added with isocyanate ethyl methacrylate. The reaction was carried out. The obtained polymer was separated into two layers after standing and did not become a uniform solution. That is, it is presumed that it was not grafted.

Example 6 A 2-separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas introduction tube was charged with 200 hydroxyl-containing silicone resin (X-22-160A, Shin-Etsu Chemical Co., Ltd., hydroxyl number 62, molecular weight 1800). Part, 2.5 moles of an adduct of isophorone diisocyanate and 2-hydroxypropyl methacrylate as unsaturated isocyanate with 1 mole to 1 mole.
And 0.2 part of dibutyltin dilaurate were added, and the mixture was reacted at 65 to 70 ° C. for 3 hours. As a result of infrared analysis, it was confirmed that the free isocyanate group disappeared.

To this, 120 parts of methyl methacrylate, 84 parts of isobutyl methacrylate, 26 parts of 2-hydroxyethyl methacrylate
Part, azobisisobutyronitrile 2.5 parts, toluene 300
Part, 1.3 parts of lauryl mercaptan, and add at 65-70 ℃ for 15
After polymerization for a period of time, 0.1 part of hydroquinone was added to terminate the polymerization.

In this way, a cloudy, syrupy polymer as the component (A) was obtained.

To 100 parts of the component (A) polymer, 10 parts of toluene, 80 parts of cuprous oxide, 10 parts of triphenyltin hydroxide and the dimethylpolysiloxane described above as the component (C).
After mixing 30 parts of KF-96 (viscosity 3000CS), 4 parts of hexamethylene diisocyanate was added as the component (B) to obtain a coating resin liquid. This resin solution was applied on a slate plate on a slate plate in the same manner as in Example 1 to give a thickness of 200
It was applied so as to have a thickness of μ, allowed to stand overnight, and then heated and cured at 100 ° C. for 1 hour.

When an underwater immersion test was conducted in the same manner as in Example 1, 12
No adherence of organisms was observed even after a lapse of months.

〔The invention's effect〕

Since the present invention is configured as described above, the adhesion to the substrate is good, even when immersed in seawater, weather resistance,
It is possible to produce an antifouling coating composition that exhibits excellent coating performance with antifouling properties.

Claims (1)

[Claims] 1. An antifouling coating composition containing the following components (A), (B) and (C): (A) having at least one active hydrogen atom in one molecule and having a main chain of constituent molecules. After reacting an unsaturated isocyanate with a silicone resin having a polysiloxane structure to convert it into a silicone resin having at least a portion having an unsaturated bond, a monomer having active hydrogen and a monomer copolymerizable therewith are required. And (B) a polyvalent isocyanate compound; and (C) a silicone resin in which the main chain of the constituent molecule is a polysiloxane bond.