JPH0391571A - Antifouling coating composition - Google Patents

Abstract

PURPOSE:To prepare a nontoxic antifouling coating compsn. having excellent stainproof properties and contg. no harmful stainproofing agent by compounding a polysiloxane-vinyl polymer block copolymer obtd. by a specific method as the film-forming component into the coating compsn. CONSTITUTION:Using a chain transfer agent comprising a polysiloxane macromonomer of formula I [wherein m is a positive integer; X is a divalent (substd.) hydrocarbon group; R1, R2, and R3 are each 1-4C alkyl, 1-4C alkoxy, (substd.) phenyl, or (substd.) phenoxy; and Y and Z are each a similar group to R1, R2, and R3, or an organosiloxane of formula II (wherein n is a positive integer; and R1', R2', and R3' are each a similar group to R1, R2, and R3)], at least one radical-polymerizable vinyl monomer is polymerized in the presence of a radical initiator to give a block copolymer consisting of a polysiloxane block and a vinyl polymer block. The block copolymer is compounded as the film-forming component to give an antifouling coating compsn., which is nontoxic, excellent in the stainproof properties, and free from a harmful stainproofing agent causative of environmental pollution.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to ships, buoys, coastal industrial plants, cooling water intake channels for thermal and nuclear power plants, offshore oil field drilling rigs, port facilities, fishing nets for aquaculture, fixed The present invention relates to an antifouling paint composition that is applied to fishing nets, seawater pollution prevention zones for marine civil engineering work, etc. (hereinafter referred to as "underwater structures").

(Prior art and its problem to be solved 11i) In the water, animals such as fujibo, serpura, mussels, oysters, sea squirts, plants such as sea lettuce and green laver, bacteria called slime, diatoms, etc. are attached. It is well known that a large number of living organisms live there, and that their attachment to the water-contacted parts of the above-mentioned underwater structures causes a large amount of industrial damage.

For example, when aquatic organisms adhere to the hull of a ship, frictional resistance with water increases, resulting in a decrease in sailing speed, and fuel consumption increases in order to maintain a constant speed, which is economically undesirable. Furthermore, if aquatic organisms adhere to structures that are fixed underwater or on the water surface, such as port facilities, it becomes difficult for these organisms to fully perform their individual functions, and moreover, they may erode the base material. Furthermore, if aquatic organisms adhere to aquaculture nets or fixed nets, the nets may become clogged and the fish may be killed.

As a countermeasure against this problem, a method of applying an antifouling paint containing an organic tin compound or a copper compound as an antifouling agent has been generally used. However, the use of such antifouling agents poses problems from the viewpoint of environmental pollution and health and safety, and there has been a desire to develop antifouling paints that do not contain harmful antifouling agents.

Many studies have been conducted on such non-toxic antifouling paints that utilize the water repellency of the paint film, that is, the low energy surface. As a simple solution, the use of water-repellent substances such as paraffin and wax has traditionally been suggested, but these additives themselves do not have film-forming properties, so the amount added is limited, and the antifouling performance is not satisfactory. There wasn't.

Further, antifouling paints have been suggested in which silicone resins, especially oligomeric room temperature curing silicone rubbers are used alone or water-repellent substances such as paraffin and silicone oil are added thereto. However, although this antifouling paint has considerably improved antifouling performance compared to the antifouling paints mentioned above, the characteristics of reaction-curing silicone rubber include uneven curing of the coating film and poor adhesion. It has drawbacks such as being difficult to reuse after opening the can, and having poor durability because the coating film is flexible.

As a result of intensive research, the inventors of the present invention have found that it is difficult for underwater sessile organisms to adhere to coatings with low surface energy or to coatings with a small coefficient of friction with water droplets, and even when they do adhere to coatings. It was found that it can be easily removed.

An object of the present invention is to provide a non-toxic antifouling paint composition that does not contain harmful antifouling agents that cause environmental pollution and has excellent antifouling performance.

(Means for Solving the Problems) The first feature of the present invention is the general formula (1) of the formula (1); R, R2 and R3 are each the same or different alkyl group having 1 to 4 carbon atoms, alkoxyl group having 1 to 4 carbon atoms,
phenyl group, phenoxydyl group, substituted phenyl group, substituted phenoxydyl group, and Y and z are the above R,, R,,
, R, or the following formula (2); %formula%) (2) (wherein, n is a positive integer, R=, ,R"2, R,
are the same groups as the above R,, R2, and R, and may be the same group or different groups. ), which may be the same group or different groups. ] As a film-forming component, a polysiloxane-vinyl polymer block copolymer obtained by polymerizing one or more radically polymerizable vinyl monomers in the presence of a radical initiator is used as a chain transfer agent. It is in the place where it is contained.

A second feature of the present invention is that it contains one or more of the above polysiloxane-vinyl polymer block copolymer and a water-repellent substance.

Next, the main components constituting the antifouling paint composition of the present invention will be specifically explained.

The polysiloxane macromonomer that is a component of the antifouling paint composition of the present invention is represented by the general formula (1) above.
It is a polysiloxane compound having one mercapto group at one end.

In general formula (1), X represents a divalent hydrocarbon group that may have a substituent that bonds a mercapto group and a silicon atom, for example, -C112-, -<CL) 2-, -(C112)
s --(CL)i-1-(Cllz)i-1-(
I blame C1l for extending to-9Clli.

R, R, and R3 are each an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms,
It is a group selected from a phenyl group, a phenoxydyl group, a substituted phenyl group, and a substituted phenoxydyl group, and the above-mentioned alkyl group and alkoxyl group having 1 to 4 carbon atoms may be chain or branched. Examples of the substituents for the above-mentioned substituted phenyl group and substituted phenoxyl group include halogen, an alkyl group or alkoxyl group having 1 to 4 carbon atoms, and an acyl group.

Rt, R2, and Rs may be the same or different groups, but alkyl groups, especially methyl groups, are preferred because they minimize the surface energy of the coating film formed from the copolymer. .

In addition, in general formula (1), Y and Z are the above-mentioned R1゜R2,
A group similar to R, or a group selected from organopolysiloxane groups represented by the following formula (2); You can. In addition, when Y and z are the same groups as R,, R2, and R1, these may also be the same or different groups.

In (2) above, R-, R-, and R1 are each an alkyl group having 1 to 4 carbon atoms, and 1 to 4 carbon atoms.
4 alkoxyl groups, phenyl group, phenoxydyl group,
A group selected from a substituted phenyl group and a substituted phenoxyl group, and the above-mentioned alkyl group and alkoxyl group having 1 to 4 carbon atoms may be straight or branched, and the above-mentioned substituted phenyl group and Examples of the substituent of the substituted phenoxyl group include halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group, and an acyl group.

R″IIR=2.R″3 may be the same or different groups, but an alkyl group, especially a methyl group, provides the lowest surface energy of the coating film formed from the copolymer. Therefore, it is suitable.

m and n are numbers representing the chain length of organosiloxane, and can be positive integers, preferably 3 to 1.000, more preferably 3 to 300.

This is because when m and n are smaller than 3, properties derived from the organosiloxane chain cannot be expected, and when m and n are too large, the strength of the copolymer decreases.

Specific examples of such polysiloxane macromonomers include those listed below.

lh 113 C11゜ C11゜ 1ll C1! .

113 l1g C11゜ IlI 113 ILs 01 bites.

C11゜ These may be used alone or in combination of two or more.

In order to obtain the polysiloxane-vinyl polymer block copolymer of the present invention, the radical polymerizable vinyl thread yarn used together with the above-mentioned polysiloxane macromonomer includes methyl (meth)acrylate,
Ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, decyl (
meth)acrylate, dodecyl(meth)acrylate,
Tridecyl (meth)acrylate, octadecyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylate having a perfluoroalkyl group having 1 to 8 carbon atoms, trimethoxysilyl Propyl (meth)
(meth)acrylates such as acrylate and dimethoxymethylsilylprobyl (meth)acrylate; styrenes such as styrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl caproate, and vinyl laurate; Examples include (meth)acrylic acid, (meth)acrylamide, maleic anhydride, acrylonitrole, and butadiene. These vinyl monomers may be used alone or in combination of two or more.

The polysiloxane-vinyl polymer block copolymer of the present invention combines one or more of the polysiloxane macromonomers and one or more radically polymerizable vinyl monomers in the presence of a radical initiator. It is obtained by copolymerizing the following.

The weight fraction of the polysiloxane macromonomer in the block copolymer is preferably 5 to 601i% by weight, and the weight fraction of the vinyl monomer is preferably 95 to 40% by weight. If the weight fraction of polysiloxane macromonomer is less than 5% by weight, the properties derived from polysiloxane chains (low surface energy) will decrease, and if it exceeds 60% by weight, the properties derived from the block copolymer will be reduced. This is because the mechanical strength and hardness of the coating film decreases.

Copolymerization of a polysiloxane macromonomer and a radically polymerizable vinyl hexamer can be carried out according to known radical polymerization methods, but if the polysiloxane macromonomer contains a hydrolyzable group, suspension Polymerization and emulsion polymerization are not very preferred.

Specific examples of radical initiators include benzoyl peroxide, barbutyl benzoate, methyl ethyl ketone peroxide, dicumyl oxide, t-butyl hydroperoxide, 2,2°-azobisisobutyronitrile, 2.2° -Azobisisovaleronitrile, 2
．． Examples include polymerization initiators commonly used in radical polymerization, such as 2°-azobis(2,4-dimethylvaleronitrile).

The weight average molecular weight of the polysiloxane-vinyl polymer block copolymer obtained as described above was approximately t, o.
oo to about t, ooo, ooo especially about 5,000 to about 30
Preferably it is 0.000.

Next, to explain the second feature of the present invention, the present invention provides an antifouling paint composition having excellent antifouling performance using the above polysiloxane-vinyl polymer block copolymer alone. However, the antifouling performance can be further improved by adding one or more water-repellent substances to this block copolymer.

Representative examples of such water-repellent substances include petrolatum, paraffin wax, liquid paraffin, dimethyl silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil,
Silicone oils such as fluorosilicone oils and silicone oils containing terminal functional groups; long-chain fatty acids and their esters such as caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, and oleic acid; and beef tallow.

Natural oils and fats include liver fat, cod fat, coconut oil, and palm oil.

In the present invention, 1FIi or 2 of the above water repellent substance
When combining 8i or higher with the above-mentioned block copolymer, the blending amount is not particularly limited; Water repellent substance 1-200% by weight based on 100% by weight
, particularly preferably from 5 to 100% by weight.

The antifouling coating composition of the present invention comprises the aforementioned polysiloxane-vinyl polymer block copolymer alone, or one or two selected from the block copolymer and a water-repellent substance.
It is prepared by dissolving or dispersing one or more species in a suitable solvent.

Such solvents have suitable volatility at room temperature,
There is no particular restriction as long as it dissolves the block copolymer, but examples include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane and heptane; ketones such as acetone, methyl ethyl ketone, dibutyl ketone, and cyclohexanone. esters such as ethyl acetate, isopropyl acetate, isobutyl acetate; diethyl ether, di-
Examples include ethers such as n-propyl ether, diptyl ether, tetrahydrofuran, and dioxane; chlorinated hydrocarbons such as dichloromethane, trichloroethylene, tetrachloroethane, and chloroform; and alcohols such as isopropanol, n-butanol, and isobutanol. . These solvents may be used alone or in combination of two or more. In particular, when solution polymerization is used as the polymerization method, it is also possible to use the block copolymer obtained by the polymerization reaction as it is diluted with a solvent without fractionating or purifying it.

The coating composition of the present invention may further contain conventional coating additives, such as coloring pigments, extender pigments, anti-sagging agents, etc.
Antisettling agents, antifoaming agents, etc. may be used according to conventional methods.

The coating composition of the present invention is prepared by dispersing the above-mentioned components using a conventionally known dispersion machine such as a ball mill or attritor.

(Function) The coating film formed from the block copolymer of polysiloxane-vinyl polymer in the present invention has a low surface energy and a low coefficient of friction with water droplets because the polysiloxane chains are strongly oriented on the surface. Characteristics are given.

This property makes it difficult for underwater organisms to adhere to this coating.
Moreover, even if it adheres, it can be easily removed, and excellent antifouling performance can be maintained for a long period of time. Further, by using the water-repellent substance mentioned in the second invention in combination, the antifouling performance is further improved over a longer period of time.

Furthermore, by copolymerizing a vinyl polymer, it becomes possible to form a polymer, which imparts mechanical strength, adhesion to the surface to be coated, and the like.

(Effects of the Invention) As explained above, the antifouling paint composition of the present invention does not contain harmful antifouling agents, and the formed coating film has low surface energy and a small coefficient of friction with water droplets. Therefore, it is difficult for living organisms to adhere to the coating, and the physical properties of the coating film surface allow it to maintain excellent antifouling performance for a long period of time. It also has excellent drying properties, storage stability, and adhesion, and can be applied to the water-contact parts of ships, fishing nets, and other underwater structures that need to prevent the attachment of aquatic organisms to achieve that purpose. .

(Examples) The present invention will be specifically described below with reference to Examples, Comparative Examples, and Test Examples, but the present invention is not limited only to the Examples. Note that parts and % in Examples and Comparative Examples indicate parts by weight and % by weight.

Production Examples 1 to 6 A polysiloxane macromonomer, a radically polymerizable monomer, 80 parts of xylene, and 20 parts of xylene were added in a glass reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube according to the formulation shown in Table 1.゜2゛ - Add 1 part of azobisisobutyronitrile and heat to 85-90℃ under nitrogen gas stream.
The mixture was stirred for 10 hours to obtain copolymer solutions A to F.

The properties of these solutions are also shown in Table-1.

Polysiloxane macromonomer (3) Polysiloxane macromonomer (4) CH3CHl 1 HS-(CH2))-8L-(0-8L)rCHs
CHs Polysiloxane macromonomer (5) CH3CHs HS-(CH2)3-3i -(0-SL)□CHs
CH1 Examples 1 to 10 Using block copolymer solutions A to E, the formulation shown in Table 2 was prepared. In the table, ISOVGIO is liquid paraffin, which is an anti-sagging agent manufactured by KF60 Seal Co., Ltd.

The following paints were also prepared for comparison.

Comparative Example 1 Copolymer solution F Erosil #2 obtained in Production Example 6 above
00 xylene. −〇CH3 ゜. □OCR.

The antifouling paint composition of the present invention was obtained by mixing and dispersing using a paint shaker in the same manner as in Example 1.

+9 is silicone oil made by Shin-Etsu Chemical Co., Ltd. Erosil #200 is Nippon Kou 90 parts 1 part 9 parts

Claims (2)

[Claims] (1) The following general formula (1); ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (However, in the formula, m is a positive integer, and X is a divalent group that may have a substituent. Hydrocarbon groups, R_1, R_2 and R_
3 is the same or different number of carbon atoms 1
~4 alkyl groups, alkoxyl groups having 1 to 4 carbon atoms, phenyl groups, phenoxyl groups, substituted phenyl groups,
It is a substituted phenoxyl group, and Y and Z are the above R_1
, R_2, R_3 or the following formula (2); ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(2) (However, in the formula, n is a positive integer, R'_1, R'_2 ,
R'_3 is the same group as R_1, R_2, and R_3 described above, and may be the same group or different groups. ), which may be the same group or different groups. ) A polysiloxane-vinyl polymer block obtained by polymerizing one or more radically polymerizable vinyl monomers in the presence of a radical initiator using a polysiloxane macromonomer shown as a chain transfer agent. An antifouling paint composition characterized by containing a copolymer as a film-forming component. (2) In claim 1, a polysiloxane obtained by using the polysiloxane macromonomer as a chain transfer agent and polymerizing one or more radically polymerizable vinyl monomers in the presence of a radical initiator. An antifouling paint composition comprising one or more of a block copolymer of a vinyl polymer and a water-repellent substance.