JPH0681824B2 - 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 relates to a coating composition having excellent releasability and antifouling property by utilizing the properties of curable resin having excellent weather resistance and low surface energy and migration of free silicone resin.

[Conventional technology and problems]

It is known that a curable silicone resin, mainly a rubber silicone resin, is mixed 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 method for producing a coating resin that is difficult to peel off.

[Means for Solving the Problems]

That is, the present invention provides an antifouling coating composition containing the following component (A) and optionally component (B): (A) (1) At least one activity in one molecule A monomer containing hydrogen and having a main chain of polysiloxane structure is reacted with an unsaturated isocyanate to convert it to a silicone resin having at least a part of unsaturated bonds, and then a monomer containing active hydrogen. A step of adding a fluorine-containing (meth) acrylate and, if necessary, a copolymerizable monomer, and polymerizing it to form a graft polymer;
And (2) a step of introducing an unsaturated bond into the graft polymer by adding unsaturated isocyanate to the graft polymer and reacting active hydrogen in the graft polymer with the isocyanate; (B) A silicone resin in which the main chains of constituent molecules are polysiloxane bonds.

The coating composition according to the present invention has excellent adhesion to metals such as iron and aluminum, concrete, inorganic building materials such as slate, wood, and the like, and by curing this, a tough and durable coating composition is obtained. It becomes possible to obtain a film.

In order to facilitate the understanding of the present invention, (A) of the composition of the present invention
The procedure for producing the components is as follows.

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.

When the polymer of the above formula is reacted with an unsaturated isocyanate, one of the graft polymers having an unsaturated bond of the present invention can be obtained.
The following equation is obtained as an example.

The unsaturated polymer according to the present invention includes (i) a ratio of a silicone resin, (ii) a degree of unsaturation of the silicone resin, (iii) a type and amount of a fluorine-containing (meth) acrylate, (iv) a type of a copolymerizable monomer. , (V) By changing factors such as the degree of unsaturation of the unsaturated graft polymer obtained by the final polymerization, it is possible to change the physical properties of the resin in a very wide range, and it is possible to deal with various uses. It will be possible.

For example, by using methyl methacrylate as a monomer, a coating film having excellent weather resistance can be obtained.

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

(A) active hydrogen-containing silicone resin, (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, with respect to 100 parts (weight part, 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 in combination and the ratio of unsaturated silicone resin to 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 alcohol whose part or all is substituted by fluorine, and the total number of carbon atoms of alkyl group, alkylene group or both groups in one molecule is 1 to 30, Is a compound such as: (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 ₂₎ a 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 mixing ratio of the unsaturated bond-introduced silicone resin and the fluorine-containing (meth) acrylate can be freely changed, but a preferred range is 10 to 95% of the unsaturated bond-introduced silicone resin, 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%.

The unsaturated isocyanate for introducing an unsaturated group into the graft polymer having active hydrogen, which is used in the step (2) for producing the component (A) of the composition of the present invention, includes various unsaturated isocyanates described above. The nart can be used as it is. The amount of the unsaturated bond in the graft polymer is preferably in the range of 1 to 30 mol%.

The component (B) of the composition of the present invention, which is a silicone resin in which the main chains of constituent molecules are polysiloxane bonds, 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 an active hydrogen group, and is preferably a viscous liquid at room temperature or a grease-like, and a viscosity of 100 in the case of a liquid. Centistokes (CS) or more, preferably 1,000 to 100,000 CS is suitable.

The mixing ratio varies depending on the purpose of use, but it is not less than 5 parts by weight of saturated silicone resin per 100 parts by weight of unsaturated graft polymer.
It is not more than 10 parts, preferably not less than 10 parts and not more than 100 parts. 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 exudes from the coating film, and the coating film surface is covered with the silicone resin, and the effect of preventing the adhesion of marine organisms is quickly lost.

A radical generating catalyst is required for curing the silicone resin graft unsaturated polymer according to the present invention, and a commonly used radical generating agent can be used for this.
In this case, it goes without saying that a reinforcing material, a filler, a coloring agent, a wax and the like can be used in combination, if necessary.

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

Example 1 In a one-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., hydroxyl number: about 35, molecular weight: 3200). 200 parts (parts by weight, the same applies hereinafter), 1.0 part of isocyanate ethyl methacrylate,
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 the free isocyanate group disappeared.

29 parts of 2-hydroxypropyl methacrylate,
Fluoroacrylate represented by the following formula Was added to 150 parts of styrene, 40 parts of styrene, and 1 part of azobisisobutyronitrile, and the mixture was polymerized at 65 to 70 ° C. for 3 hours. Then, 0.1 part of hydroquinone was added to terminate the polymerization.

The appearance of the obtained resin was a cloudy liquid exhibiting thixotropy.

Then, 30 parts of isocyanate ethyl methacrylate and 0.5 part of dibutyltin dilaurate were added, and the mixture was reacted at 60 to 65 ° C. for 6 hours under dry air. An unsaturated polymer grafted with a loose syrup-like fluoroacrylate was obtained. As a result of infrared analysis, it was confirmed that the free isocyanate group disappeared. This unsaturated graft polymer was used as the component (A) of the composition of the present invention.

On the other hand, a polymerized homolog of dimethylpolysiloxane (KF96 series, Shin-Etsu Chemical Co., Ltd.) was selected as the component (B) silicone resin, and 50 parts of 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 3,000CS 4 30,000CS 5 300,000CS Resin composition 100 obtained by mixing components (A) and (B)
3 parts by weight of "Darocur # 1173" manufactured by Merck Co., Ltd. as a photo-curing initiator was added to the parts (parts by weight, the same applies hereinafter), and the product was manufactured by Showa High Polymer Co., Ltd. Put Splaydam T-300F putty to a thickness of 1.5 mm, paint it on the cured coating film to a thickness of 0.7 to 0.8 mm, output 30
20 cm under the lamp of the KW ultraviolet irradiation device was passed at a speed of 2 m / min. No cellophane adhesive property was observed in any of the cured coating films, and the peel strength was 0.1 kg / inch or less.

A cured coating plate and a slate plate separately were immersed in seawater from April to October, using a hard polyvinyl chloride plate having the same size and a thickness of 3 m as a comparative example.

The results are shown in Table 1.

As can be seen from Table 1, the viscosity of silicone resin is 3,000C.
It was estimated that the addition of S and 30,000CS was relatively good, and the migration rate of the silicone resin from the cured coating film was appropriate. It is presumed that this is because the migration speed of the silicone resin from the cured resin coating film is moderate, and therefore, the adhesion of shellfish and algae is permanently excluded. Further, since the antifouling paint of the present invention contains fluorine, it has an effect of making it more difficult for marine organisms to adhere to it, as compared with a paint containing no fluorine.

Example 6 100 parts of the unsaturated polymer (A) used in Example 1 was thoroughly mixed with 80 parts of cuprous oxide and 10 parts of triphenyltin hydroxide, and 2 parts of 328E of Kayaku Nouri Co., cobalt naphthenate was added to the mixture. 1 part, 0.2 part of dimethylaniline, and 50 parts of a silicone resin KF96 (viscosity 3000CS) were mixed in the same manner as in Example 1, and the thickness of the resin solution was applied on a slate plate to a thickness of 1 to 1.5 mm. Was applied.

After standing overnight, it was heated and cured at 60 ° C. for 6 hours.

An immersion test in the sea was conducted in the same manner as in Examples 1 to 5, but no adhesion of organisms was observed even after 12 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.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08F 299/08 MRY 7442-4J

Claims (1)

[Claims] 1. An antifouling coating composition containing the following component (A) and, if necessary, component (B): (A) (1) A molecule having at least one active hydrogen atom in one molecule. Is reacted with an unsaturated isocyanate in a silicone resin having a polysiloxane structure as a main chain to convert into a silicone resin having at least a part of unsaturated bonds, and then a monomer having active hydrogen, fluorine-containing (meth) acrylate And a copolymerizable monomer, if necessary, and polymerized to form a graft polymer;
And (2) a step of introducing an unsaturated bond into the graft polymer by adding unsaturated isocyanate to the graft polymer and reacting active hydrogen in the graft polymer with the isocyanate; (B) A silicone resin in which the main chains of constituent molecules are polysiloxane bonds.