GB2163754A

GB2163754A - Sealing composition for use in coating ships' hulls

Info

Publication number: GB2163754A
Application number: GB08521446A
Authority: GB
Inventors: Yoshihiko Ono; Toshihiko Ochiai; Naozo Matsumoto
Original assignee: Kobe Paints Ltd
Current assignee: Kobe Paints Ltd
Priority date: 1984-08-29
Filing date: 1985-08-29
Publication date: 1986-03-05
Also published as: DK377285D0; JPS6157661A; DE3530771A1; NL8502352A; KR870002217A; DK377285A; GB8521446D0; GB2163754B; KR900003425B1

Abstract

Ships' hulls are coated with both anti-corrosive paint and anti-fouling paint. Recently, paint containing epoxy resin, coal tar-epoxy resin or coal tar-denatured vinyl resin, as a vehicle, and paint principally containing acrylic resin as a vehicle, have assumed importance as anti-corrosive and anti-fouling paints, respectively. However, the combined use of anti-corrosive and anti-fouling paints based on these different kinds of vehicle is apt to cause problems. The present invention relates to sealing compositions for coating on existing antifouling paint layers of ships' hulls for alleviating such problems. These sealing compositions comprise a vehicle of which 10 to 70% by weight is an acrylic resin having a glass transition point of 10 DEG C or less. Fresh anti-fouling or anti-corrosive paint layers can then be applied on the sealing layer.

Description

SPECIFICATION Sealing composition for use in ship hull paint The present invention relates to sealing compositions for use in ship outer hull paint.

Paint containing oil- or alkyd resin as vehicle has been used for anti-corrosive paint for a long time. In addition, recently solvent evaporation drying type paint containing chlorinated rubber or denatured vinyl resin as vehicle has been widely used for the substitute for said paint containing oil- or slkyd resin as vehicle.

Anti-fouling paint to be applied on anti-corrosive paint has generally contained resin of the same system as in anti-corrosive paint as vehicle.

On the other hand, cross-linking type resin paint such as epoxy resin and coal tar-epoxy resin or paint containing coal tar-denatured vinyl resin as vehicle, which exhibits anti-corrosive function for a long time, has taken an important position as anti-corrosive paint as a result of the investigation on economy.

In addition, rosin has been added to anti-fouling paint containing oil- or alkyd resin, chlorinated rubber or denatured vinyl resin as vehicle in order to dissolve anti-fouling agents contained in paint and the dissolution of anti-fouling agent from paint film accompanied by the hydrolysis and water solubilization of rosin has been utilized.

However, such paint has shown a disadvantage in that insoluble layers (generally referred to as skeleton layers) are gradually formed on the surface of ship bottom during its voyage whereby the surface roughness of hull-bottom is increased and the anti-fouling function is remarkably reduced.

In order to improve such a disadvantage, various kinds of investigation were performed and as a result remarkably improved anti-fouling paint has been practically used at present.

These mostly are copolymers of vinyl group-containing monomers which are called generically acrylic resin.

That is to say, they principally comprise at least one kind of copolymers of acrylic acid or methacrylic acid or various kinds of alkyl ester, hydroxyalkyl ester and amide thereof, styrene, vinyl tuluene, ithaconic acid, maleic acid and the like. Although denatured vinyl resin and other resins, which are compatible with these copolymers, are partially added according to circumstances, paint containing such acrylic ingredients mainly as vehicle and cuprous oxide, organic tin-containing compounds and sulfur-containing compounds as anti-fouling agent solely or in combination has been well received by the popular name of Long Life A/F as anti-fouling paint exhibiting strong anti-fouling power for a long time.

In addition, copolymers of at least one kind of various kinds of acrylic ester or methacrylic ester and esters of methacrylic acid or acrylic acid and organic tin or organic lead "organometalcopolymers" exhibit anti-fouling effect due to bonded organometalcompounds isolated from polymers by the hydrolysis of a paint coating formed thereof and per se are gradually flown away from the surface of hull with a stream of sea water after the dissociation of organometalcompounds whereby marine lives can be prevented from adhering to the surface of hull or removed from the surface of hull, so that organometalcompounds have been practically used solely or in combination with various kinds of conventional anti-fouling agent. They are called generically self-grinding type A/F.

As a result of the advanced investigation on the respective aimed performance under such conditions, anti-corrosive paint and anti-fouling paint has used quite different resin as vehicle and as a result, different kinds of resin paint have been applied in layers in most cases.

That is to say, at first anti-corrosive paint containing coal tar, denatured vinyl resin, epoxy resin, epoxy resin-coal tar or epoxy-urethane resin-coal tar as vehicle has been applied and then the above described Long Life A/F or self-grinding type A/F has been applied directly on said anti-corrosive paint, or, primer called binder or sealer-coat containing chlorinated rubber resin, denatured vinyl resin or denatured vinyl chloride-coal tar as vehicle has been applied on anticorrosive paint containing epoxy resin, epoxy resin-coal tar or epoxy urethane resin-coal tar as vehicle and then Long Life A/F or self-grinding type A/F has been applied thereon.

Even in case where different kinds of resin paint are applied in layers, as far as anti-fouling paint is applied on anto-corrosive paint, as described hereon, no problem occurs in the drying, adhesion and the like of coated film.

However, a hull is apt to come into collision with an anchor or an anchor chain, a fender of quay, floatages on the sea and the like to be injured and in order to repair such injured portions anti-corrosive paint is applied in a touch up manner. Thus anti-corrosive paint is applied on antifouling paint in the vicinity of such injured portions.

Further, depending upon the kind of anti-fouling paint, it is preferable according to circumstances that a primer is applied all over the surface of old anti-fouling paint left on the surface of hull bottom as a binder and then anti-fouling paint is applied thereon.

In such a case, if the known anti-corrosive paint or primer is applied on Long Life A/F containing acrylic resin principally as vehicle or self-grinding type A/F, only the surface is dried while the under-layer Long Life A/F or self-grinding type A/F absorbs solvents to be softened whereby the drying and solidification of the underlayer is remarkably delayed and as a result, its drying and solidification requires 2 or 3 days although the drying and solidification of the respective paint used soley generally requires only several hours and cracks are produced in a primer film as the surface layer.

In addition, in case where anti-corrosive paint is tar-epoxy paint, even though tar-epoxy paint film completed its cross-linking reaction, old A/F layer disposed thereunder contains solvents yet and as a result, it is left under the soft condition whereby leading to the delamination of paint film during the voyage of ship in most cases.

The present inventors achieved the present invention as a result of the hard investigation for solving the above disadvantages of ship outer hull paint.

That is to say, the present inventors found that the sealing compositions comprising acrylic resin having the glass transition point of 1000 or less at a ratio of 10 to 70% by weight can overcome the disadvantages incidental to the known anti-corrosive paint and primer and as a result, can be satisfactorily applied on Long Life A/F containing "acrylic resin" principally as vehicle or self-grinding type A/F.

Although it is not obvious yet why the sealing compositions of the present invention produce no trouble when applied on an old A/F paint layer, it seems that in case where they contain the similar acrylic resin as in A/F paint layer and said acrylic resin has the glass transition point of 1000 or less, even though solvents contained in the compositions are temporarily penetrated into the under layer old A/F paint layer, solvents are distributed between an old A/F paint layer and the composition according to the present invention in a well-balanced relation whereby the difference between the underlayer old A/F paint and the composition according to the present invention in evaporation of solvent, that is to say drying and as a result, the drying and solidification of paint film as a whole can be normalized.

In case where the sealing composition according to the present invention is applied on an old A/F paint film and normally dried and solidified, no drying trouble and insufficient adhesion occur even though A/F paint or tarepoxy paint is newly applied on the sealing composition according to the present invention.

It is essential that acrylic resin used in the present invention has the glass transition point of 1000 or less. With acrylic resin having the glass transition point exceeding 10 C the effects of the present invention are reduced. Even a primer containing acrylic resin solely as vehicle not only does not give sufficient effects but also is inferior in other properties according to circumstances.

The use of acrylic resin having the glass transition point of 10 C or less at a ratio of at most 70% by weight based on vehicle characterizing the present invention per se exhibits an effect, that is to say the composition of suitable combination can be obtained.

Furthermore, even in case where acrylic resin having the lowest glass transition point of those known at present is used, the practical effect can not be attained unless it is contained in vehicle at a ratio of at least 10% by weight.

Acrylic resin may be contained in vehicle at a less ratio with a reduction of glass transition point.

Acrylic monomers for obtaining acrylic resin having the glass transition point of 1000 or less used in the present invention include alkyl ester such as methyl ester, ethyl ester, propyl ester, butyl ester, hexyl ester, t-butyl ester, 2-ethylhexyl ester, octyl ester, lauryl ester and stearyl ester; hydroxyalkyl ester such as hydroxyethyl ester and hydroxypropyl ester; aminoalkyl ester such as dimethylaminoethyl and diethylaminoethyl; alcoxyalkyl ester such as methoxyethyl ester and ethoxyethyl ester of acrylic acid or methacrylic acid; acrylaminde; methacrylamide; acrylonitrile; methacrylonitrile; cyclohexyl ester; benzyl ester; organic tin-containing ester such as tributyl stannate and triphenylstannate; organic lead-containing ester such as tributyl lead and triphenyl lead of acrylic acid or methacrylic acid; and the like.

In addition, vinyl group contained monomers copolymerizable to these acrylic monomers include styrene, vinyl styrene, vinyl toluene, maleic acid, fumalic acid, ithaconic acid, vinyl acetate, vinyl chloride and the like. Polymers having the glass transition point of 1000 or less obtained by polymerizing or copolymerizing at least one kind of these monomers at a suitable ratio can exhibit the effect of the present invention.

As described above, the main factor of the composition according to the present invention is the glass transition point Polymers or copolymers having too high molecular weight are disadvantageous in painting work. Polymers and copolymers having molecular weight of 200,000 or less are suitable used.

Next, the resin, which has been used in the conventional solvent evaporation film forming type anti-corrosive paint or primer as vehicle, may be used for the resin usable as the ingredient of 90 to 30% by weight added to acrylic resin having the glass transition point of 1000 or less of 10 to 70% by weight as vehicle in the composition according to the present invention.For example, chlorinated polyolefine such as chlorinated rubber, cyclized rubber, chlorinated polyethylene and chlorinated polypropylene; "denatured vinyl chloride resin" obtained from vinyl chloride and at least one kind of vinyl group-contained monomer such as vinyl chloride and vinyl acetate, vinyl chloride and vinyl isomethyl ether, vinyl chloride and vinyl isobutyl ether and vinyl chloride, vinyl acetate and maleic acid; petroleum resin; cumaron resin; coal tar; coal tar pitch; and further various kinds of plasticizer if needed may be used solely or in combination.

In addition, in the production of the composition according to the present invention, it is effective to use materials, which have been used usually for paint, such as extender pigments such as calcium carbonate, talc and balite; anti-rust pigments such as zinc phosphate, aluminium phosphate, zinc chromate and red lead; aluminium powders; coloring pigments; stabilizers; pigment-wetting agents; dispersing agents; levelling agents; and flow-preventing agents, according to circumstances.

The present invention will be in more detail described below with reference to Examples. Parts all are expressed by weight.

Example 1 Butyl acrylate (250 parts) and xylene (150 parts) were put in a flask provided with a refluxtype condenser, a stirrer and a thermometer. The content of the flask was heated to temperatures of 90 to 100"C and then benzoil peroxide (2 parts) was added. After holding the reaction mixture at those temperatures for 4 hours benzoil peroxide (still more 1 part) was added. Benzoil peroxide (1 part) was added still more two times every two hours to complete the reaction.

Subsequently, the content of the flask was cooled and then xylene (100 parts) was added to produce a 50% polymer solution. The glass transition point of the resulting polymer was -45"C.

Example 2 Xylene (150 parts) was put in a flask provided with a reflux-type condenser, a stirrer and a thermometer. A mixture solution comprising butyl acrylate (175 parts), butyl methacrylate (50 parts), styrene (25 parts) and benzoil peroxide (1 part) was added to the content of the flask drop by drop for 2 hours with holding temperatures of 90 to 100"C and then benzoil peroxide (1 part) was added three times every two hours to complete the polymerization reaction.

Subsequently, the content of the flask was cooled and then xylene (100 parts) was added to produce a 50% polymer solution. The glass transition point of the resulting polymer was -20"C.

Example 3 Xylene (150 parts) was put in a flask provided with the same equipments as in Example 2. A mixture solution comprising ethyl acrylate (190 parts), ethyl methacrylate (50 parts), 2-hydroxylethyl methacrylate (10 parts) and benzoil peroxide (1 part) was added to the content of the flask drop by drop for 2 hours with holding temperatures of 90 to 100"C and then benzoil peroxide (1 part) was added three times every two hours to complete the polymerization.

Subsequently, the content of the flask was cooled and then xylene (100 parts) was added to produce a 50% polymer solution. The glass transition point of the resulting polymer was -2"C.

Example 4 Sealing compositions for use in ship outer hull paint having blending ratios 1-7 as shown in Table 1 were prepared from 50% polymer solutions produced in Examples 1 to 3, a resin solution on the market VIOMET 300 (50% solution of copolymer of methyl methacrylate and tributyltin methacrylate manufactured by M & T Co., Ltd., glass transition point: 0 C) and VIOMET 303J (50% solution of copolymer of methyl methacrylate, octyl acrylate and tributyltin methacrylate manufactured by M & T Co., Ltd., glass transition point: 8"C).

Then the sealing compositions having the above described blending ratios 1-7 was applied at a dry film thickness of about 50,u on anti-fouling paint containing acrylic resin principally as vehicle applied on an iron plate on which anti-rust paint was previously applied and the drying state and surface state of coated film were investigated.

The results are shown in Table 2. It was proved from Table 2 that the sealing compositions according to the present invention were superior to the conventional primer shown as Comparative Examples.

Furthermore, even though anti-fouling paint was further applied on dried sealing compositions, the underlayer formed of anti-fouling paint was not softened.

In addition, even though coal tar-epoxy paint was applied on these sealing compositions, it was softened to an extent less than that in Comparative Examples.

Table 1

Eu l $, Dl - o ratio 1 2 3 4 5 6 7 tive tive Ld Example v ~~ N N H No. 1 2 59 ~ resin solution (1 10 30 40 15 30 70 20 - 40 % chlorinated rubbe 75 65 45 - - - 75 75 P Z E1 I uo V\ C) O 0 ( u\ m O 25 rl denat'ured vinyl F F N FJ N N N H O resin solution (3) F O m O denatured vinyl O O O UO I I - 25 O C F N rlr(CUrl I (4) 50 . petroleum resin - - 24 - - - - - O I | (5) Coal tar - I N 20 15 7 Ir\ .S~ Ufi O I 8 9 1 I > m - 0 1 O Red oxide 10 20 - 25 N H N N N + Zinc | O I I OI - 10 10 V\OI 5 I N OJ N ~{ N OJ r C Aluminium povder 20 - 20 - 15 < V M O 20 I 15 I ( 25 25 20 (h N 25 Talc cm 15 15 N N > 1 61 N 15 20 N ~ . ~ O U O O ( OI 25 35 - - 25 1t \0 N ~1 N t1 c1 c1 N . . .

H Soivesso &num; 100 o 15 15 o O o - 15 15 9 r( uU (Vr( O 0 o z / o a qn 2 > &num; 1 ::S $ t h h o I ^ M X g e o g 8 < X 21 b ft h ID^ 4 o H H /4 a hv P O~ h El a / e < e oi h v g o 1 +4 o &commat; X o &commat; o o H A to t e o 0 e e At1 S H O; &commat; &commat; ffi I fi t tfi wtaj 5 o S o i M < > o o N h st h 1 0 CZ P4 a t*J 1 Ez IDt : 0Q L &commat; oA XU&commat;fl6 & Xu&commat;tlos (Notes) (1):50% resin solution was produced in Examples 1 to 3.

(2):40% chlorinated rubber solution was obtained by dissolving chlorinated rubber (ALLOPRENE R-10) manufactured by ICI Co., Ltd., England of 40 parts by weight in xylene of 60 parts by weight.

(3): 25% denatured vinyl resin solution was obtained by dissolving vinyl chloride resin (VINYLITE RESIN VAGH) manufactured by Union Carbide Co., Ltd. of 25 parts by weight in a mixture solvent consisting of MIBK of 37.5 parts by weight and xylene of 37.5 parts by weight.

(4): 40% denatured vinyl resin solution was obtained by dissolving vinyl chloride resin (LARO FLEX MP 45) manufactured by BSAF Co., Ltd. of 40 parts by weight in xylene of 60 parts by weight.

(5):50% petroleum resin solution was obtained by dissolving petroleum resin (PETROSIN 120) manufactured by Mitsui Petroleum Chemical Co., Ltd. of 50 parts by weight in xylene of 50 parts.

(6):CERECHLOR 48 manufactured by IC Co., Ltd., England was used for a plasticizer.

Table 2

--sPT----- State of coated film Anti-fouling Blending the sealing compositions after the sealing paint (1) ratio Resin solu- according to the present compositions according No. applied on tion used invention or primers to the present inven an iron plate No. were a lied er rs d primers 'were 1 A 1 Example 1 0 0 Excellent 2 A 2 Example 2 0 3 A 7 VIOXET 303J ed 4 A Comparative - L= A Cracked xam Is oO.r 1 5 B 3 YIOMHT 303J ~ ~ ~ ~ ~ ~ 6 B 4 VIOMET 300 0 0 I1 7 - B 5 Example 2 N 0 8 as: h 6 Example 3 0 0 N v d ~ ~ ~ ~ ~ w . ~ ~ ~ ~ ~ ~ 4 n v 10 ..,xoooc X 000 11 000 12 C 6 VIOMHT 303J 0 8 d C Comparative O x A Cracked 13 qo cu le Ir\ 2 14 D 1 Example 1 0 0 Excellent 15 D 4 Example 2 0 16 r( D 5 VIZ razzI r t H 300 to o 6 VION:BT | Comparative o 1 P ~~~ . ~ 0F ~ ~ ~ ~ 0t ~ P ~ ~ ~ ~ oF 3 tH eN tN a H N F P n + uo qz P n uo vD hZo1 - st un vo A l . : < < < A ffi m m m C) CM C) C) Q n Q a n U ~1 N n + UN qD ti 08 HO t1 61 1 H H vD H (Notes) anti-fouling Paint (1) applied on an Iron Plate A: Paint containing acrylic resin as the main ingredient manufactured by Kobe Paint Co., Ltd. (KP COAT A/F HTS-T) B : Paint containing copolymer of tributyltin methacrylate as the main ingredient manufactured by Kobe Paint Co., Ltd. (KP ACE SP A/F 100) C : Paint containing copolymer of tributyltin methacrylate as the main ingredient manufactured by Chugoku Paint Co., Ltd. (AF SEA FLO Z-1000) D: Paint containing copolymer of tributyltin methacrylate as the main ingredient manufactured by Nippon Oil & Fats Co., Ltd. (TAKATA LLL No. 2) (2) Evaluation Standard of Drying State o : Excellent - No mark is left on the surface of coated film even though it is pushed by fingers.

A: Slightly Excellent - Marks are left on the surface of coated film when it is pushed by fingers.

X: Bad - A coated film is slipped out of position when it is pushed by fingers.

it is shown from the above Tables that the use of the sealing compositions for use in ship outer hull paint according to the present invention containing acrylic resin having the glass transition point of 10 C or less at a ratio of 10 to 70% by weight leads to an excellent coated state and drying state of coated film.

Claims

1. A sealing composition for use in ship hull paint, characterized by acrylic resin having the glass transition point of 10 C or less at a ratio of 10 to 70% by weight.

2. A sealing composition as set forth in Claim 1, characterized in that said acrylic resin having the glass transition point of 10 C or less comprises the ingredients containing at least one kind of monomer expressed by the following general formula and/or vinyl group contained monomer copolymerizable thereto:

wherein R,: hydrogen or methyl group; R2 hydrogen or alkyl-, hydroxyalkyl-, aminoalkyl-, alcoxyalkyl, organic tin-containing- and organic lead-containing group of C-C20.

3. A sealing composition as set forth in Claim 1, characterized in that the ingredients of 90 to 30% by weight other than said acrylic resin in said composition comprise at least one kind of material of chlorinated rubber, cyclized rubber, chlorinated polyolefine and copolymers of vinyl chloride and other vinyl group contained monomer, petroleum resin, cumaron resin, coal tar, plasticizer and the like.

4. A sealing composition for use in ship hull, paint, substantially as hereinbefore described.

5. A process of preparing a sealing composition for use in ship hull paint, substantially as hereinbefore described.