JPH02252773A - Antifouling coating composition - Google Patents

Abstract

PURPOSE:To improve the adhesiveness to a substrate material and weathering and antifouling properties in sea water by compounding a specific graft polymer, a polyisocyanate, and a silicone resin. CONSTITUTION:100 pts.wt. silicone resin having at least one active hydrogen in the molecule and comprising a polysiloxane backbone structure is reacted with 0.01-10 pts.wt. unsatd. isocyanate to give a silicone resin of which at least a part contains an unsatd. bond. 10-95wt.% resulting silicone resin is polymerized with a mixture of 1-30mol% active hydrogen monomer with 70-99mol% copolymerizable monomer to give a graft polymer. 100 pts.wt. graft polymer. 0.1-30 pts.wt. polyisocyanate, and 5-150 pts.wt. silicone resin with the polysiloxane backbone structure are compounded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an antifouling paint composition.

In particular, the present invention provides an antifouling paint that exhibits excellent mold releasability and antifouling properties by utilizing the properties of a curable resin that has excellent weather resistance and low surface energy, and the migration of free silicone resin. The present invention relates to a composition.

[Conventional technology and issues]

It is known to mix a curable silicone resin, mainly a rubber-based silicone resin, with a liquid having a releasing effect, such as silicone oil, to form a coating that has an antifouling effect, especially in seawater.

The same thing has been reported regarding thermoplastic type silicone resins.
No. 62-15 describes a reaction-curing silicone composition.
No. 6172 discloses a polymer of vinyl silicon,
JP-275132 discloses a copolymer of a polysiloxane macromer and a nil monomer.

However, existing coatings based on silicone resins tend to peel off due to poor adhesion to the base material under conditions where they are constantly exposed 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, exhibits an antifouling effect, has good adhesion to the base material, and sufficiently withstands repeated stress such as waves, making it suitable for practical use. This invention relates to a coating composition that is difficult to peel off.

[Means to solve the problem]

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

In this way, by finally curing the paint containing free silicone resin, the paint film has both durability and adhesion, and at the same time, moderate migration of the silicone resin from the cured paint film makes it possible to It has the effect of preventing the adhesion of shellfish and algae.

The final cured resin according to the present invention consists of: (i) proportion of unsaturated silicone resin; (ii) amount of monomer having active hydrogen; (iii) type of monomer; (iv) type and amount of polyvalent isocyanate; (V) proportion of saturated silicone resin. Depending on the type and amount, the physical properties can be varied over a wide range, making it suitable for a wide variety of uses.

The coating composition according to the present invention has excellent adhesion to metals such as iron and aluminum, inorganic building materials such as concrete and slate, and wood, and by curing it, a strong and durable coating film can be created. It becomes possible to obtain.

To aid in understanding the present invention, (A) of the composition of the present invention
The procedure for producing the components is illustrated below.

fh Active hydrogen-containing silicone resin Unsaturated isocyanate (
isocyanatoethyl methacrylate) (unsaturated bond-introduced silicone resin) + (vinyl monomer/active hydrogen-containing monomer) The above formula shows an example in which styrene is used as the monomer and 2-hydroxyethyl methacrylate is used as the monomer having active hydrogen. .

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

(a) silicone resin having active hydrogen, (b) unsaturated isocyanate, (c) monomer having active hydrogen, and optionally further (d) copolymerizable monomer of component (A) of the composition of the present invention. The silicone resin (A) used for manufacturing has a main chain of the constituent molecules of the following formula (however, R,
R' has a polysiloxane structure (alkyl group, phenyl group), and contains at least one active hydrogen, typically a hydroxyl group, that can react with isocyanate in one molecule.
It is necessary to own it individually.

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

X-22-160A Hydroxy value 62 Molecular weight 1
800 X-22-160B Hydroxy value 35 Molecular weight 3
200 X-22-1・60C hydroxyl value 20 molecular weight 560
0 Unsaturated isocyanates (b) for introducing unsaturated bonds into these hydroxyl group-containing silicone resins include a) compounds that share an isocyanate group and an unsaturated bond in one molecule, b) diisocyanate Examples include adducts of 1 mole to 1 mole of Nate and unsaturated monoalcohol, and the like.

Examples of unsaturated incyanates include isocyanate ethyl methacrylate, methacryloyl isocyanate, 1-isopropenyl-α, α-dimethylbenzyl isocyanate, and isocyanate ethyl methacrylate (formula below) % formula % is generally handled. It is suitable from the viewpoints of properties, reactivity of incyanate, etc.

Examples of the reaction product of diisocyanate and unsaturated alcohol include a 1 mole to 1 mole adduct (formula below) of 2,4-tolylene diisocyanate and 2-hydroxyethyl methacrylate.

C1l.

In this case, the diisocyanate includes 2,4-tolylene diisocyanate, isophorone diisocyanate,
Preference is given to different types of reactivity of the two incyanato groups.

The reaction ratio between active hydrogen of silicone resin and unsaturated isocyanate is 100 parts of silicone resin (parts by weight, same below)
The amount of unsaturated isocyanate is 0.01 part or more and 10 parts or less, preferably 0.1 part or more and 3 parts or less. In this case, it is not necessary to react all of the active hydrogen present; the extent to which it reacts depends on the type of monomer used in combination and the ratio of the unsaturated silicone resin to the monomer.

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

The monomers to be used in combination with the copolymerizable monomer may be any monomers as long as they are copolymerizable with the copolymerizable monomer, and commonly commercially available types are used. There are no particular restrictions on the type, but examples include styrene, vinyltoluene, acrylic esters, methacrylic esters, acrylonitrile, methacrylate trile, vinyl acetate, ethylene, butadiene, and the like.

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

Taking these into consideration, the proportion of the unsaturated bond-introduced silicone resin is 10 to 95% (weight %, the same hereinafter), preferably 20 to 90%.

The proportion of the active hydrogen-containing monomer (c) to be used is desirably about 1 to 30 mol % when the total monomer is taken as 100, with the remainder being the copolymerizable monomer (d).

A graft polymer with active hydrogen (A> is added to
Examples of the polyvalent isocyanate compound (B) for curing the resin by reacting with this compound include the following types.

2.4-) lylene diisocyanate, 2.6-) lylene diisocyanate, 2.4-) mixture of lylene diisocyanate and 2.6-) lylene diisocyanate, diphenylmethane diisocyanate, inphorone diisocyanate, xylylene diisocyanate Nato, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, 1,5 naphthylene diisocyanate, polyisocyanates represented by the following general formula.

Adducts of these isocyanates and, for example, polyols, in which isocyanate groups remain, can also be used.

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

Component (C) of the composition of the present invention, a silicone resin whose main chain of constituent molecules is a polysiloxane bond, is represented by the following general formula.

(However, R+ and R2 are alkyl groups or aryl groups.) This silicone resin has no active hydrogen and is preferably a viscous liquid or grease-like at room temperature, and if it is a liquid, it has a viscosity of 100 centistokes ( CS) Above, preferably 4! There are 1,000 to 100,000 OOCS.

The mixing ratio of each component of the composition of the present invention varies depending on the purpose of use, but 0.1 to 30 parts by weight of the polyvalent isocyanate compound (B) is mixed per 100 parts by weight of the unsaturated graft polymer which is the component (A). part, preferably 1 to 20 parts by weight, more preferably 2 to 10 parts by weight, and the silicone resin as component (C) is 5 to 150 parts, preferably 10 to 100 parts or less of the saturated silicone resin. If the proportion of saturated silicone resin used is too high, the coating film will become soft and its role as a protective coating will be impaired; if it is too small, the purpose of adding it will be lost.In other words, the added silicone resin will ooze out little by little from within the coating film and damage the coating surface. Covered with silicone resin, the effect of preventing the attachment of marine life is quickly lost.

Of course, reinforcing materials, fillers, colorants, waxes, etc. can be used in combination with the silicone resin-grafted unsaturated polymer according to the present invention, if necessary.

Next, the present invention will be further explained by examples.

E1 and -1 Goj Into a 21 separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas inlet tube, a silicone resin having a hydroxyl group (X-22-1608, manufactured by Shin-Etsu Chemical Co., Ltd.,
200 parts (hydroxyl number approximately 35, molecular weight 3200)
0.8 parts of incyanate ethyl methacrylate and 0.2 parts of dibutyltin dilaurate were added, and the mixture was reacted at 60 to 65°C for 4 hours. As a result of infrared analysis, it was observed that free isocyanate groups had disappeared.

To this, 40 parts of 2-hydroxy 10-pyl methacrylate, 177 parts of styrene, 300 parts of toluene, 4 parts of azobisisobutyronitrile, and 2 parts of tertiary-butyldodecanethiol were added, and at 75 to 80°C, azobisisobutyronitrile was added. After adding 2 parts of butyronitrile and polymerizing for 16 hours, 0.1 part of hydroquinone 7-methyl ether was added. A slightly viscous and cloudy solution of the homogeneous graft polymer of component (A) was obtained.

To 100 parts of this (A) component polymer solution, 7 parts of inphorone diisocyanate as the (B) component and 0.3 parts of dibutyltin dilaurate were added, and dimethyl polyester was added as the (C) component silicone resin. Siloxane polymer complexes (KF96 series manufactured by Shin-Etsu Chemical Co., Ltd.) were used, and 50 parts of each were added to 100 parts of unsaturated polymer (A). The viscosity of the silicone resin used in each example is
It is as follows.

Example 1 10CS 2 100CS 3 3000CS 4 30.0OOCS 5 300,000CS 30ci
A coating composition prepared by mixing components (A), (B), and (C) as described above was applied onto the cured coating film to a thickness of about 200 μm. was applied with a bar coater. After leaving it as it was overnight, it was heated at 100° C. for 1 hour to harden it.

Separately, in the case of only a slate board, a hard polyvinyl chloride board of the same size and thickness of 3 cm 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, the viscosity is 300 as silicone resin.
It is clear that the best addition effect is obtained by using a substance having a concentration of about 0 to 30,000C3.

This is presumed to be because the rate at which the silicone resin migrates from the cured resin coating is moderate, and thus has the effect of permanently repelling the adhesion of shellfish and algae.

Table 1 Blank: When silicone resin is not added Zero wheel evaluation method O: When marine organisms are attached to less than 10 (%) of the total area 1
: When the adhesion area is 10 to 20 (%) 2: When the adhesion area is 20 to 30 (%) 3: When the adhesion area is 30 to 40
(%) 4: When the adhesion area is 40 to 60 (%) 5: Full surface adhesion ratio [In Example 1, instead of the silicone resin to which isocyanate ethyl methacrylate was added, a silicone resin with active hydrogen was used. (manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-1608
The reaction was carried out in the same manner as in Example 1, except that .

The obtained polymer separated into two layers on standing and did not form a homogeneous solution. In other words, it is presumed that it was not grafted.

IM - In a 21 separable flask equipped with a ball stirrer, a reflux condenser, a thermometer, and a gas inlet tube, silicone resin having a hydroxyl group (Shin-Etsu Chemical Co., Ltd. X-22-160^, hydroxyl value 62, molecular weight 1800) was added. ) and 200 parts of isophorone diisocyanate as unsaturated isocyanate.
and 1 mole of 2-hydroxypropyl methacrylate to 1
2.5 parts of molar adduct, 0.0 parts of dibutyltin dilaurate.
2 parts were added and reacted at 65-70°C for 3 hours. As a result of infrared analysis, it was observed that free isocyanate groups had disappeared.

To this were added 120 parts of methyl methacrylate, 84 parts of isobutyl methacrylate, 26 parts of 2-hydroxyethyl methacrylate, 2.5 parts of azobisisobutyronitrile, 300 parts of toluene, and 1.3 parts of lauryl mercaptan.
After polymerization at 5-70°C for 15 hours, 0.0% of hydroquinone was added.
1 part was added to stop the polymerization.

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

To 100 parts of this (A) component polymer, 10 parts of toluene,
After mixing 80 parts of tR suboxide, 10 parts of triphenyltin hydroxide, and 30 parts of dimethylpolysiloxane KF-96 (viscosity 3000C3) described above as component (C), 4 parts of hexamethylene diisocyanate as component (B) was added, It was used as a resin liquid for coating. This resin liquid,
In the same manner as in Example 1, it was applied to a thickness of 200 μm on a spray dam coating film applied on a slate board, and after being left overnight, it was 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 biological attachment was observed even after several months had passed.

〔Effect of the invention〕

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

Claims (1)

[Scope of Claims] An antifouling paint composition containing the following components (A), (B), and (C): (A) having at least one active hydrogen in one molecule; A silicone resin whose chain has a polysiloxane structure is reacted with an unsaturated isocyanate to convert it into a silicone resin with at least a portion of unsaturated bonds, which can then be copolymerized with a monomer having active hydrogen as necessary. A graft polymer obtained by adding a monomer and polymerizing; (B) a polyvalent isocyanate compound; and (C) a silicone resin whose main chain of constituent molecules is a polysiloxane bond.