Note: Descriptions are shown in the official language in which they were submitted.
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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
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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
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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):
R2 R2
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.
EXAMPLE 1
4,5-Dichloro-2-n-octyl-3-isothiazolone 5%
Tetraethylthiuram disulfide 10~o
Acrylic resi~ (in 6~% 2cyle~e solution) 20%
Xylene 65%
EXAMPLE 2
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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%
EXAMPLE 4
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%
EXAMPLE 5
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%
~ EXAMPLE 7
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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%
113XAMPLE 8
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%
EXAMPLE 9
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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EXAMPLE 1 0
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%
EXAMPLE 11
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, $he following formulations
were also tested for their ef~lcacy.
COMPARATIVE EXAMPLE 1
4,5-I~ichloro-2-n-octyl-3-isothiazolone 15%
Acrylic resin (in ~0% xylene solution~ 22%
Xylene . 63%
COMPARATIVE E~LE ~
4,6-I~ichloro 2-(4'-chlorobenzyl)-3 isothiazolone 16%
Acrylic resill (in ~0% xylene solution) 22%
: Xylene . 63%
COMPAR~TIVE :!3XAMPLE 3
S-Chloro-2-phenethyl-3-iæothiazolone 1~%
Acryli.~ resin (ln 50% ~ylene solution) 22%
~ ~ylene 63%
:~ COMPA:R~TIVE EXAMPLE 4
4,5-Dichloro-2-n-he$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~
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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%
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The results are shown in Table 1 below.
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TABLE 1
Time (month) 1 2 3 4
FoImula on ~ _
Example 1 1 2 2 3
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¦0 w~- ~;w w ~ 1 ~ 5
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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.
