CA2012308A1 - Antifouling agent for fishnets - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The present invention as disclosed provides an anti fouling agent for fish nets that contains as effective ingredients at least one compound represented by the general formula (I):

(I) where X1 and X2 are each a hydrogen atom, a halogen atom or a lower alkyl group with at least one of X2 being a halogen; and Y is an alkyl group having 1-14 carbon atoms, an aryl group, a substituted aryl group having phenoxy, hydroxy, trihalomethyl, halogen, lower alkoxy or lower alkyl as a substituent, and aralkyl group or a substituted aralkyl group having halogen, lower alkoxy or lower alkyl as a substituent, and one of both of at least one compound represented by the general formula (II):
R1 -(S)m -R1 (II) where R1 is an alkyl group having 1-20 carbon atoms; and m is an integer of 2-10 and at least one compound represented by the general formula (III):

Description

`

r,ANTIFOULlNG Al:~ENT FOR FI~HNETS

BACKG:ROUND OF THE IN~ENTION
The present inventiun relates to a heavy metal- and pollution-free antifouling solution ~or fishnets that ef~ectively prevents the attachment of marine foulingorganisms to nets, either for use in cultivation ~arms or ~or ~tationary :net f~lshery, ::as well as to items submerged in water such as accessolies i`or fishnets.
.~Fishnets for use in cultivation farms or in stationary net fishery a~ld ropes .:used with them are submerged iIl ~eawater for a proloIlged period and are prone to be i~fested w~th extensive attachment OI mari~e fouling organisms includi:~lgseaweeds, b~rnacles, tube worms, polyzoans and mollusks. The attac~nsnt of '~ ~the e marine fouling organism~ prevents economical use of fi~hnets and costs lots $ ~of labor and money in maintenance work. It has therefore been desired to develop ` ~'an antifouling agent for fishnet;s that ~emains ef~ective and econom}cal ~or a prolonged period and which i~ ~imple to use without causing pol}ution of the ~"
environment.
With a view~ to attaining this objective, various studies and proposals have been made and it is generally known that a serie~ of organotin compounds ~e.g.
trialkyi or triphenyl tin compounds) are ef~ective for practical purposes.
Howeverj mos~ of tbe~prev;ously proposed organotin compounds are highly toxic and products containing them might cause dainage to users if not handled carefillly, They are also disadvantageous from the viewpoi~t of the need to prevent environmental pollutio~. For thesc reasons, the advent of a heavy metal-and pollu~ion-free antifouling agent for fishnets has been strongly desired.
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Japanese Patent Publication No. 50984/1986 shows an antifouling agent for marine structures that contains 3-isothiazolone as an effective ingredient.
JapaIlese Patent Applicatio~ (OPI) No. 34604/lg81 (the term OPI as used herein means an une~amined published Japanese patent applicat;o~) shows a marine s antifouliIlg agent or an antifouling solutio~sfor fishnets that employstetlachloroisophthalonitrile. Japanese Patent Application (OPI) No. 8150~/1981 shows a marine anti~ouli~g agent or an antifouling solution for fishnets that emplLoys a dialkyl sulfide or tetraalkylthiuram disulfide compound. Japanese PateIIt Application (OPI) No. 118006/1981 shows a marille a}ltifouling agent or an a~ ouling sol-ltioll for f~lshnets that employs a combiIlatio~ of the three compo~ents mentioned above. However, these compounds, whe~l taken individually, are ~ot satis~actory for practical purpo~e~ since t'hey are comparatively low in their ability to prevent attachment of marine antifouling orga~isms, L~ addition, very f~w of them exhibit a desired antifouling ef~lcacy against a broad spectrum of fouli~g organisms. Although some of the proposals :,.
made in the above listed patents are being commercialized, there still is a need to develop an antifouling agsnt for fishnets that is potentially low in environme~
hazard and tox~city to fish ~d wh;ch yet shows satisfactory results in practicalapplica~ions.

SUMMARY OF THE INV:13NTION
The present inventors cvnducted intensive studies in searsh for an antifouling agent for fishnets that is low in toxicity and risk of environmental pollution (heavy metal- and pollution-free) aIld which is easy to use. As a result, they have accomplished the present invention which will be described below in detail.

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.. According to one aspect, the present invention provides an antifouling agent tor fishnets that contains as effecti~!e ingredients at least one compound represellted by the general formula (I):
X~
,1 . N (I) X2/ \S/ ~ Y

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where X~ d :~2 are each a hydrogen atom, a haloglen atom or a lower alkyl group, with at least one of Xl and X2 being a haloge~; a~ld Y is ~ al~yl group havi~g 1- 14 carbon atoms, an aryl group, a substituted aryl group having phenoxy, hydro~y, trihalomethyl, halogen, lower alkoxy or lower alkyl a~ a substituent, a~ aralkyl group, or a substituted aralkyl group having halogen, lower alkoxy or lower alkyl as R substituent, and one or both of at least one compound repres~nted by the general formula tI~:
Rl--(S)m--Rl (~) where Rl is an alkyl group having 1 - 20 carbon atoms; and m is an integer of 2 -10 a~d at least one compound represented by the general formula ~m):

N -- C -- S -- S -- C --N (m) S S
where R2 is an alkyl group having 1 4 carbon atoms.
AccordiIlg to another aspect, the present inver~tion provides an antifouling agent for fishnets that additionally contains tetrachloroisophthalonitrile as aneffective ingredient.

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According to ~he studies co~ducted by the prese~tinventors,com poundsofthe general formulas (I), (~) and (m) and tetrachloroisophthalonitrile, when taken i~dividually, arelow in ~heir ability ~o prevent attachxnent of marine a~ti~ouling organism s and he~ce are not satisfactory for use in practical applications.
However, when ~e eompound (I) and one or both of the compounds (II) and are used in combination, or if th ey are co m bin ed with tetrachloroisophthalonitrile, un-expectedly high synerg~stic efl~ects are exhibited and ~fouling agen~s that contain them show balanced effec~s i~ practical applicatioIls while pre~e~lting low toxicity to ffsh a~d mi~imal risk of .s e~vironme~talpollutio~.

.` DEl'AII,ED ESCRIPTION OF TEE INVENTION
Exannples of ~he com pound represented by the generalform ula (i)include: 5-chlorophe~yl-2-n-decyl-3-iso~hiazolone, 5-chloro-2 phenethyl-3-isothiazolQne, 4-bromo-2-n-dode~yl-3-isothiazolone, 4,5-dichloro-2-n-octyl-3-isothia~olone, 4-methyl-5-chloro-2-(d~'-chlorobenzyl)-3-isothiazolo~et 4,5-dichloro-~-(4'-chloro-benzyl)-3-isothiazolone9 4,5-dichloro-2-(4'-chlorophenyl)-3-isothiazolone, 4,5-dichloro-2-(2'-methoxy-3'-chlorophenyl)-3-isothiazolone, 4,5-dibromo-2-(4'-chlorobenzyl)-3-isothia~olone, 4-methyl-5-chloro-2-(4'hydroxyphenyl)-3 isothia2010ne, 4,~-dichloro-2-~-hyxyl-3-isothia~olone, and ~-chloro-2-(3',4'-dichlorophenyl)-3-isothia2oloIle. Of course, these are not the sole examples of compound (I) that can be used in the present irlvention.
Examples of the compou~d represented by the ge~eral fol~ula (It) include:
diethyl pentasulfide, dipropyl tetrasul~lde, diisopropyl trisulfde, di-t-butyl ditetrasulfide, dihexyl pentasulfide, dioctyl tetrasul~lde, di-t-nonyl pentasulfide, .

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dodecyl pentasul~lde, ditetradecyl tetrasulfide, dinonadecyl tetrasulf~lde, and utyl decasulfide. Of course, these are nok the sole examples of compound (~
that can be u~ed in the present invelltion.
Examples of the compound represented by the general fo~nula (m) include:
tetraethylthiuram disul~lde, tetraisopropylthiuram disulfide, and tetra-n-butylthiuram disulfide. Ot' course, these are not the sole exarnples of compound(D~) that can be used in the present illvention.
E~amples of ~e solvent that can be used ;~ the present invention i~clude ~ylene, solvent rlaphtha, diethylbenzene, pseudocurnene, mesitylene, ~riethylbenzene and butyl acet te, with xylene, solvent naph~a, pseudocumene a~d butyl acetate being pre~erred.
The n~ixing proportions of the compound (I) and or both of the compounds (II) and (m), and tetrachloroisophthalo~itrile if this is used, alld the total amount of their u~e are not limited to any values since these fac~ors w~ll vary both with the a~tifouling performa~ce required of the ~l~al product and with the coIlditions of the environment in which it is used. Normally, these compounds a:lld optional tetrachloroisophthalo~itrile are used in amounts ra~ging from 3 to 30 parts, desirably ~rom 8 to 20 parts, per 100 parts of the final product.
The mixin~ propor$ioll~; of the compound (I) and or both of the compounds (II) alld (m) and the optional component tetrachloroisophthalonitrile can be varied in accordance with the specific conditions of the environrlle3~t in which the anti~ouling ageIlt of the present invention is used. Additional ingredients thatare know~ to be ef~ective and safe may also be incorporated aIld this of~ers theadvantage that more balanced e~ects are anticipated against various marine foullng organlsms.

The antifouling so~ution for fishnets of the present invention can be prepared /Yith ease. Compound (I) and one or both of the compounds (II) and (m), ~nd optionally tetrachloroisophthalonitrile may be dissolved in solveIlts such ~s xylene, solvent naphtha and pseudocum~ne together with resins such as natural re~ins, oily resins, synthetic resin and sy~thetic rubber-base resins that are employed in ordinary paint~, and optional additives such as colora~t~ and pla~ticizers that may be incorporated ~ required. AdvaIItageou~ resins i~clude polyacrylics, polybuteIles, rosins, coumarone resi~s, polyvinyl chloride, chlorinated rubb~rs, alkyd resins, a~ld ethylene/vinyl acetate copolymer resins.The following examples are given ~or illustrating the formulation of the ~nti~ouling agent for fishnets of the present invention. It should hovrever be noted that the present invention is by no means limited by these examples. Ltl the ~ollowing examples, the amount~ of all ingredie~ts incorporated are expressed in weight perceIlt.

4,5-Dichloro-2-n-octyl-3-isothiazolone 5%
Tetraethylthiuram disulfide 10~o Acrylic resi~ (in 6~% 2cyle~e solution) 20%
Xylene 65%

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5-chloro-2-n-decyl-3-isot,hiazolone 6%
Di-t-nonyl pentasulf~lde ~L0%
Acrylic resill (in 50% xylene solut;on) 22%
Xylene 63%

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' EXA~'IE 3 4,5-Dichloro-2-(4'-chlorobenzyl)-3-isothiazolone 5%
Tetraethylthiuram disulfide ld%
Acrylic resin (in ~0% xylene solutioll) 22%
Polybutene , ~%
Xylene 48%
Pseudocume~e 10%

4,5-Dichloro-2-(4'-chlorophenyl)-3-isothiazolone 3%
4-3!~ethyl-5-chloro-2-(4'-hydroxyphenyl)-3-isothiazolone 2%
Te~raethylthiuram disul~lde 10%
Acrylic resin ~in ~% xylene solution) 22%
Xylene ~3%
Pseu~ocumelle 10%

4-Bromo-2-~-decyl-3-isot;hiazolone . ~%
Tetraethylthiuram disulfide 6%
Di-~dodeeyl pentasul~lde 6%
Acrylic resin (i~ 50% xylene solution) 22%
Coumarone 3%
Xylene 5~%
EX~LE 6 4-Methyl-5-chloro-2-~4'-chlorobenzyl)-3 isothiazolone 5%
Tetraethylthiuram disulf~lde 6%
Di-t~nonyl pentasulf~lde 6%

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Acrylic resin (in 50% xylene solution) 22%
Xylene 61%
i Pseudocumene 10%
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4,5-Dichloro-2-n-octyl-3-isothiazolone 3%
5-Chloro-2-phenethyl-3-isothiazolone 2%
Tetraethylthiuram disulfide 6%
Di-t-nonyl pentasulfide 6%
Acrylic resin (in 50% xylene solution) 22%
Xylene 61%

4,~-Dichloro-2-n-octyl-3-isothia~olone ~%
Di-t-nonyl pentasul~lde ~%
Tetrachloroisophthalo~itrile 5%
Acrylic resin ~in 50% xyle~e solutioll) 22%
Xylene 43%
Pseudocume~e 20%

4,5-Dichloro-2-(4'-chlorophe~yl)-3-isothiazolone ~%
Di-~lonyl pentasul~lde 6%
Tetrachloroisophthalonitrile 5%
Acrylic resin (in 50% xylene solution) 22%
Xylene 43%
Pseudocumene 20%

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~!L~'3 4,5-Dichloro-2-(4'-chlorobenzyl)-3-isothiazolone 6%
Tetraethylthiuram disulfide 5%
Tetrachloroi~ophthalonitrile 5%
Acrylic resin ~in 50~o xylene solution) 22%
Xylene 43%
Pseudocumene 2û%

4,5-Dichloro-2-n-hexyl-3-isothiazolone 3%
4,6-Dichloro-2-n-tridecyl-3-isothiazolone 2%
Tetraethylthiuram disulfide 5%
Tetrachloroisophthalonitrile 5%
Acrylic resin (in ~0% xylene solution) 22%
Xyle~e 43%
Pseudocumene 20%
XA~LE 12 4,5-Dichloro-2-n-octyl-3-isothia7010ne 5%
I)i-~nonyl pentasulfide 3%
Tetraethyl~hiuram disulfide 3%
Tetrachloroisophthalonitrile 5%
Acryl;c resin (in 50% ~ylene solution) 22%
Xylene 42%
Pseudocumene 20%

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The e~lcacy of the above-noked ~ormulations of antifouling agent was tested in the experiment described below. As comparisons, $he following formulations were also tested for their ef~lcacy.

4,5-I~ichloro-2-n-octyl-3-isothiazolone 15%
Acrylic resin (in ~0% xylene solution~ 22%
Xylene . 63%
COMPARATIVE E~LE ~
4,6-I~ichloro 2-(4'-chlorobenzyl)-3 isothiazolone 16%
Acrylic resill (in ~0% xylene solution) 22%
: Xylene . 63%
COMPAR~TIVE :!3XAMPLE 3 S-Chloro-2-phenethyl-3-iæothiazolone 1~%
Acryli.~ resin (ln 50% ~ylene solution) 22%
~ ~ylene 63%
:~ COMPA:R~TIVE EXAMPLE 4 4,5-Dichloro-2-n-he$yl 3-isothiazolone 6%
4,5-Dichloro-2-n-tridecyl-3-isothiazolone 10%
Acrylic resin (in: 50% xylene solution) ~2%
Xylene - 63%

EXPE:RIMENT
Polyethylene fishnets (6 knots, 400 d/60 yarns) were dip-coated with the antifouling formulations prepared in Examples 1- 12 and Comparative E~amples : - . :

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1- 4. After being dried with air, the nets were submerged about 1 m below sea level 1;l Tanabe Bay, Kii, Wakayama, Japan in early September of 1987 and held there for 4 months in order to investigate the time-dependent attachment of marine fouling organisms on the ne~s. The results were evaluated by the following criteria.

Rating Attachment of fouling organism~
1 none -~ , ., . ~
2 less than 1%
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3 less than 5%
4 from 5% to less thaIl 10%
. 5 10- 20%

6 20~.- S0%
_ _ . ... , .,_ _ ~ _ more than 50~O

The results are shown in Table 1 below.

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Time (month) 1 2 3 4 FoImula on ~ _ Example 1 1 2 2 3 ;; , ~ _ _ _ _ ¦0 w~- ~;w w ~ 1 ~ 5 , Untreated _ _ _ _ _ As the data in Table 1 shows, the formulations that incorporated the co:mpound (I) arld olle or both of the compounds (II) and (m), or those which contained tetrachloroi~ophthalollitrile in addition to these compounds provided high-performance antifouling agents for ~lshnets that exhibited persistent synergistic eflEects against attachment of marine antifouling organisrns in a ":' ' ' .
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bala~ced and hence practically effective way while e~suring great safety by causing only low to:~icity ~ fi~h.

Claims (2)

1. An antifouling agent for fishnets that contains as effective ingredients at least one compound represented by the general formula (I):

(I) where X1 and X2 are each a hydrogen atom, a halogen atom or a lower alkyl group, with at least one of X1 and X2 being a halogen; and Y is an alkyl group having 1 - 14 carbon atoms, an aryl group, a substituted aryl group having phenoxy, hydroxy, trihalomethyl, halogen, lower alkoxy or lower alkyl as a substituent, an aralkyl group, or a substituted aralkyl group having halogen, lower alkoxy or lower alkyl as a substituent, and one or both of at least one compound represented by the general formula (II):
R1 - (S)m - R1 (II) where R1 is an alkyl group having 1- 20 carbon atoms; and m is an integer of 2 -10 and at least one compound represented by the general formula (III):

(III) where R2 is an alkyl group having 1 - 4 carbon atoms.

2. An antifouling agent for fishnets that contains as effective ingredients at least one compound represented by the general formula (I):

(I) where X1 and X2 are each a hydrogen atom, a halogen atom or a lower alkyl group, with at least one of X1 and X2 being a halogen; and Y is an alkyl group having 1 - 14 carbon atoms, an aryl group, a substituted aryl group having phenoxy, hydroxy, trihalomethyl, halogen, lower alkoxy or lower alkyl as a substituent, an aralkyl group, or a substituted aralkyl group having halogen, lower alkoxy or lower alkyl as a substituent, and one or both of at least one compound represented by the general formula (II):
R1 - (S)m - R1 (II) where R1 is all alkyl group having 1- 20 carbon atoms; and m is an integer of 2 -10, and at least one compound represented by the general formula (III) (III) where R2 is an alkyl group having 1 - 4 carbon atoms, and tetrachloro-isophthalonitrile.