JPS6254833B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an antifouling composition for fishing nets that does not cause stiffness or stickiness in fishing nets. [Prior Art] Tributyltin methacrylate copolymer has been used as an excellent fishing net antifouling agent. [Problems to be Solved by the Invention] However, fishing nets treated with conventional tributyltin methacrylate copolymers become stiff in cold regions. As a result, the fishing net becomes bulky when being wound up or stacked, making it difficult to move and transport the fishing net, and in extreme cases, the membrane cracks, resulting in fouling. To improve this, there is a method of copolymerizing a monomer with a low glass transition point with tributyltin methacrylate, but the use of the tributyltin methacrylate copolymer obtained in this way causes extreme tackiness in the coating film, and the thin polymer The membrane is destroyed. In addition, the solubility of the paint film is accelerated, and the antifouling effect is shortened. [Means for Solving the Problems] In order to improve the above-mentioned drawbacks, the present inventors, as a result of intensive research, have developed a fishing net barrier obtained by blending specific tributyltin methacrylate copolymers with different compositions. If you use a dirt composition,
The inventors have found a solution to the above problems and have arrived at the present invention. That is, the present invention provides a fishing net antifouling agent mainly comprising a copolymer of tributyltin methacrylate and another polymerizable unsaturated compound, wherein the copolymer contains (a) 30 to 80 units of tributyltin methacrylate;
% by weight, the remaining part is the general formula CH ₂ = CH−
30 to 70% by weight of one or more copolymers containing units of an acrylic acid ester compound represented by COOR (in the formula, R represents an alkyl group having 4 to 12 carbon atoms) and (b) tributyl. 60-90 units of tin methacrylate
Weight%, units of methyl methacrylate 10-40
% by weight, one or more copolymers containing units of unsaturated compounds, the remainder of which can be polymerized
This antifouling composition for fishing nets is characterized by using a copolymer mixture consisting of 70 to 30% by weight. Examples of the acrylic ester used in (a) of the present invention include n-butyl acrylate, iso-butyl acrylate, t-butyl acrylate, amyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate. Examples include acrylate, preferably butyl acrylate,
2-ethylhexyl acrylate and amyl acrylate. Furthermore, examples of the polymerizable unsaturated compound in (b) of the present invention include methyl acrylate,
Ethyl acrylate, n-butyl acrylate,
Acrylic acid esters such as amyl acrylate and hexyl acrylate, ethyl methacrylate,
Examples include methacrylic esters such as butyl methacrylate and cyclohexyl methacrylate, and polymerizable vinyl monomers such as vinyl acetate, styrene, and vinylpyrrolidone, with acrylic esters being preferred. The antifouling composition for fishing nets of the present invention consists of 30 to 70% by weight of one or more copolymers (a) and 70 to 30% by weight of one or more copolymers (b). It is a copolymer mixture. The copolymer in (a) of the present invention contains tributyltin methacrylate units in an amount of 30 to 80% by weight. 30
If the amount is less than % by weight, the hydrolyzability of the copolymer (a) itself will be impaired. Moreover, if it exceeds 80% by weight, the strength decreases and it becomes brittle. (a) is the part responsible for flexibility, and the general formula CH ₂ =
In acrylic acid ester compounds represented by CH-COOR (R = C ₄ - C ₁₂ alkyl), those where R is 3 or less carbon atoms have a poor contribution to flexibility, and those with 13 carbon atoms
The above causes significant adhesion. (b) is a part mainly responsible for antifouling properties, and (b) of the present invention
The copolymer contains 60 to 90% by weight of tributyltin methacrylate units. If it is less than 60% by weight, the antifouling property will decrease. Moreover, if it exceeds 90% by weight, it becomes sticky, which is not preferable. Furthermore, the copolymer in (b) of the present invention contains 10 to 40% by weight of methyl methacrylate. Even if it is less than 10% by weight or more than 40% by weight, sufficient strength cannot be imparted to the coating film. The use of 10-40% by weight of methyl methacrylate is essential. Furthermore, the antifouling composition for fishing nets of the present invention is composed of copolymer (a) and copolymer (b), but when the content of copolymer (a) is less than 30% by weight, it becomes tough. In this case, the copolymer composition of copolymer (b) cannot compensate for the flexibility, while when copolymer (a) exceeds 70% by weight, the copolymer composition of copolymer (b) cannot compensate for the flexibility. It cannot compensate for staining and promotes a decrease in the strength and tackiness of the coating film, both of which are undesirable. The thus obtained antifouling composition for fishing nets of the present invention may be prepared by adding a coloring dye if necessary, to hydrocarbons such as toluene and xylene, alcohols such as denatured alcohol, butyl alcohol, and isopropyl alcohol, ethyl acetate, butyl acetate, etc. It is dissolved using various solvents such as esters and ketones as appropriate to make a dipping bath, and a fishing net is immersed in the dipping bath, taken out, dried, and applied to the fishing net. [Effects of the Invention] The antifouling composition for fishing nets of the present invention has the following features. That is, by using the specific tributyltin methacrylate copolymer blend of the present invention, compared to conventional tributyltin methacrylate copolymers, it exhibits a long-term antifouling effect, and also has extremely low tackiness despite its high flexibility. A useful fishing net without stiffness can be obtained. Next, the present invention will be explained with reference to production examples and examples, where % in each example indicates weight %. Production example A: 160 g of tributyltin methacrylate, 240 g of amyl acrylate, and 400 g of xylene were placed in a 1-4 neck flask equipped with a thermometer, reflux condenser, and stirring motor, and then 5 g of benzoyl peroxide was added, and the mixture was heated to 90° to 95°C. Polymerization was carried out for 8 hours to obtain a copolymer solution [A]. This copolymer solution [A] is a slightly yellow liquid with a heating residue of 49.8% and a viscosity of
It had a weight average molecular weight of 41,000 and a weight average molecular weight of 180 cps (25°C). Production Examples B to K Put the polymerizable monomers shown in Table 1 below into the same flask as in Production Example A, and then polymerize under the same conditions and same operations as Production Example A to obtain copolymer solutions [B] to
Obtained [K]. In all production examples, the same amounts of xylene and benzoyl peroxide as in production example A were used.

[Table] The physical properties of each copolymer obtained were as shown in Table 2.

【table】

[Table] Examples 1 to 5 Copolymer solutions [A] obtained in Production Examples A to E
[E] was mixed in the proportions shown in Table 3 below to prepare the antifouling composition of the present invention. In addition, (a) and (b) of these compositions
The copolymer ratio is shown in the same table.

[Table] Comparative Examples 1 to 5 Copolymer solutions [F] obtained in Production Examples F to J
[J] was used as it was to prepare antifouling compositions of Comparative Examples 1 to 5. The composition ratios of monomer units contained in the solids of Comparative Examples 1 to 5' were the same as those of Examples 1 to 5, as shown in Table 4.

[Table] Comparative Examples 6 to 7 For comparison, copolymer solution [K] was used instead of copolymer solution [B] in Examples 3 and 4,
Comparative Examples 6 and 7 were prepared by mixing with copolymer solutions [D] and [E] in the following proportions. Comparative Example 6 Solution [K]: 10 parts and Solution [D]: 20 parts Comparative Example 7 Solution [K]: 15 parts and Solution [E]: 15 parts Comparative Examples 8 to 9 In Examples 2 and 3 (a) , (b) Comparative Examples 8 and 9 were obtained by changing the copolymer ratio as shown below. Comparative Example 8 Solution [A]: 6 parts and solution [E]: 24 parts
(a) 20%, (b) 80% Comparative Example 9 Solution [B]: 24 parts and solution [D]: 6 parts
(a) 80%, (b) 20% Strength and tack evaluation test 100 parts of each antifouling composition obtained in Examples 1 to 5 and Comparative Examples 1 to 9 was diluted by adding 100 parts of xylene.
Polyethylene fishing nets (24 pieces, 8 sections) for each diluted solution.
20×40 cm sections were immersed, removed after a few minutes, and air-dried at room temperature for 1 day. The tackiness can be measured at room temperature (15
℃). Thereafter, the net was left in a -5°C room for 8 hours, and in the same room, the stiffness was examined by touching an untreated fishing net of the same shape as a blank. The results are shown in Table 5. Antifouling Test 100 parts of each of the antifouling compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 9 were diluted by adding 250 parts of xylene.
Polyethylene fishing nets (24 pieces, 8 sections) for each diluted solution.
A 30×40 cm section was immersed, removed after a few minutes, and air-dried at room temperature for 1 day. Each of the nets treated in this way was attached to an iron frame and subjected to immersion in a hanging raft for 6 months in Owase Bay, Mie Prefecture. The results are shown in Table 5.

【table】

Claims (1)

[Scope of Claims] 1. A fishing net antifouling agent containing as a main component a copolymer of tributyltin methacrylate and another polymerizable unsaturated compound, wherein the copolymer contains (a) 30 to 30 units of tributyltin methacrylate; 80
% by weight, the remaining part is the general formula CH ₂ = CH−
30 to 70% by weight of one or more copolymers containing units of an acrylic ester compound represented by COOR (in the formula, R represents an alkyl group having 4 to 12 carbon atoms) and (b) tributyl. 60-90 units of tin methacrylate
Weight%, units of methyl methacrylate 10-40
% by weight, one or more copolymers containing units of unsaturated compounds, the remainder of which can be polymerized
An antifouling composition for fishing nets, characterized in that it uses a copolymer mixture comprising 70 to 30% by weight.