JPH06102772B2 - 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, the existing coatings based on these silicone resins are easily peeled off due to poor adhesion to the base material under conditions of constant exposure to waves, such as when immersed in seawater. It is difficult to maintain the antifouling effect over 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. After reacting the nato to exchange it with a silicone resin having at least a part having an unsaturated bond, a monomer having active hydrogen, a fluorine-containing (meth) acrylate and optionally a copolymerizable monomer are added thereto to carry out polymerization. Graft polymer obtained by: (B) polyisocyanate compound; and (C) silicone resin in which the main chain of constituent molecules is a polysiloxane bond.

Thus, after introducing an unsaturated bond by reacting an unsaturated isocyanate with a silicon resin having active hydrogen, a monomer having active hydrogen and a fluorine-containing monomer copolymerizable therewith are added to obtain a polymer. The graft polymer used is a polyvalent isocyanate compound as a cross-linking component, and a silicone resin with a polysiloxane structure is used in combination with this to finally cure the coating material containing free silicone resin. It also has the effect of preventing the adhesion of shellfish and algae in water by the appropriate migration of the silicone resin from the cured coating film.

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 and amount of fluorine-containing (meth) acrylate (iv) type and amount of polyvalent isocyanate (V) The physical properties can be changed in a wide range depending on the type and amount of the saturated silicone resin, and it can be used for various purposes.

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.

The above formula shows an example in which 1,1,1,3,3,3-hexafluoroisopropylmethacrylate is used as the fluorine-containing monomer and 2-hydroxyethylmethacrylate 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) Silicone resin having active hydrogen, (b) unsaturated isocyanate, (c) monomer having active hydrogen, (d) fluorine-containing (meth) acrylate and, optionally, (v) copolymerizable monomer.

The silicone resin (a) used for the production of the component (A) of the composition of the present invention has a main chain of constituent molecules represented by 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, diisocyanate includes 2,2-tolylene diisocyanate, isophorone diisocyanate, and the like.
Preference is given to different types of reactivity of the individual isocyanate groups.

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 or less with respect to 100 parts (weight part, the same below) of the silicone resin. Below the section. 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 fluorine-containing (meth) acrylate (d) used in the present invention is an acrylic acid ester or methacrylic acid ester of an alcohol having a fluorinated alkyl group and / or alkylene group, and is a hydrogen atom of an alkyl group or an alkylene group. Acrylic ester or methacrylic acid ester of an alcohol, wherein all or a part of them are substituted by fluorine, and the total number of carbon atoms of an alkyl group, an alkylene group or both groups in one molecule is 1 to 30, Compounds as exemplified: (However, m = 0 to 18, n = 0 to 18, R = H or CH ₃ C
O, X = H or CH _3, R '= H or CH ₃ (CH ₃₎ which is n).

The monomer used in combination as the copolymerizable monomer (e) may be any monomer as long as it can be copolymerized with the monomer, 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 ratio of the unsaturated bond-introduced silicone resin and the fluorine-containing (meth) acrylate can be freely changed, but normally, the unsaturated bond-introduced silicone resin is 10 to 95% (wt%, the same applies hereinafter),
It is preferably 20 to 80%.

The use ratios of the monomer (c) having active hydrogen, the fluorine-containing (meth) acrylate (d) and the copolymerizable monomer (e) are 1 to 30, 1 to 70 and 0, respectively, when the total monomer is 100. It is desirable that the content is ˜69 mol%.

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 an isocyanate group remains can also be used.

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.

It is the component (C) of the composition of the present invention. A silicone resin in which the main chain of the constituent molecule is a polysiloxane bond 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.

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 of (B) polyvalent isocyanate compound per 100 parts by weight.
-30, preferably 1-20, more preferably 2-10 parts, and the silicone resin as the component (C) is 5 to 150 parts, preferably 10 to 100 parts or less of a saturated silicone resin. If the proportion of the saturated silicone resin used is high, the coating becomes soft and the role of the protective coating is impaired.

That is, the added silicone resin gradually bleeds from the coating film, covering the coating film surface with the silicone resin, and the effect of preventing the adhesion of seawater 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 inlet tube, a silicone resin having a hydroxyl group (X-22-160B, manufactured by Shin-Etsu Chemical Co., Ltd., a hydroxyl value of about 35, Molecular weight 3200) 200 parts (weight part, the same applies hereinafter), isocyanate ethyl methacrylate 1.0 part,
Charge 0.2 parts of dibutyltin dilaurate, 4 at 60-65 ℃
Reacted for hours. As a result of infrared analysis, it was confirmed that the free isocyanate group disappeared.

29 parts of 2-hydroxypropyl methacrylate,
Fluoroacrylate represented by the following formula 150 parts, styrene 40 parts, toluene 380 parts, and azobisisobutyronitrile 2 parts were added and polymerized in a nitrogen stream at 65 to 70 ° C. for 3 hours. Toluene 100 parts and hydroquinone 0.1 part were added to terminate the polymerization. .

The appearance of the obtained graft resin (A) was a milky white liquid exhibiting thixotropy.

Polymerization of dimethylpolysiloxane as a silicone resin of the component (C) was performed by adding 6 parts of isophorone diisocyanate as the component (B) and 0.2 part of dibutyltin dilaurate to 100 parts of the solution of the component (A) polymer. Using a homologue (KF96 series manufactured by Shin-Etsu Chemical Co., Ltd.), 50 parts of each was added to 100 parts of the saturated 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 slate plate with a thickness of 6 mm was coated with Showa Polymer Co., Ltd. Spray Dam T-300F to a thickness of 1.5 mm and cured. On the coating film thus formed, (A) as described above,
The coating composition obtained by mixing the components (B) and (C) was applied twice with a bar coater to a thickness of about 200 μm. After leaving it alone, 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 effect of addition is the best, although the one around 30,000CS is used.

It is presumed that this is because the migration rate of the silicone resin from the effect resin coating film is moderate, and thus there is an action of permanently excluding the adhesion of shellfish and algae.

Example 6 A 2-separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas introduction tube was charged with a silicone resin having a hydroxyl group (Shin-Etsu Chemical Co., Ltd.) X-22-160A, a hydroxyl value of 62, and a molecular weight of 1800. 200 parts, 1 mol to 1 mol of an adduct of isophorone diisocyanate and 2-hydroxypropyl methacrylate as unsaturated isocyanate 2
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. Then 1,1,1,3,3,
3-hexafluoroisopyropyrmethacrylate (the following formula) 220 parts, 2-hydroxypropyl methacrylate 30
Parts, 1 part of azobisisobutyronitrile, and 450 parts of toluene were added, and the mixture was polymerized in a nitrogen stream at 65 to 70 ° C. for 16 hours, and then 0.1 g of hydroquinone was added to terminate the polymerization.

Thus, a cloudy thixotropic liquid polymer as the component (A) was obtained.

To 100 parts of this component (A) polymer, 80 parts of cuprous oxide, 10 parts of triphenyltin hydroxide, 10 parts of toluene and the above-mentioned dimethylpolysiloxane K as the component (C)
After mixing 30 parts of F-96 (viscosity 3000CS), 4 parts of hexamethylene diisocyanate was added as the component (B) to prepare a coating resin liquid. This resin solution was applied on a slate plate coating film on a slate plate in the same manner as in Example 1 to give a thickness of 200 μm.
The coating solution was applied so that the coating composition had the same thickness as above, and was left 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, no adherence of organisms was observed even after 12 months had elapsed.

〔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. Is converted to a silicone resin having a polysiloxane structure by reaction with an unsaturated isocyanate to convert it into a silicone resin having at least a part of unsaturated bonds, and then a monomer having active hydrogen, a fluorine-containing (meth) acrylate and optionally a A graft polymer obtained by adding a copolymerizable monomer accordingly; (B) a polyvalent isocyanate compound; and (C) a silicone resin in which the main chain of the constituent molecule is a polysiloxane bond.