JP2005021123A - Coating agent for float - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating agent for a float to form a float having excellent durability and usable for a long period without causing the lowering of the buoyancy of the float, the change of appearance and the adhesion of organisms to the float. <P>SOLUTION: The coating agent for a float is composed of a two-pack solvent-free urethane resin [I] composed of (a) a polyisocyanate component, (b) a polyol component and (c) a catalyst. Preferably, the resin is a urethane resin [I-1] wherein the polyisocyanate component (a) is composed mainly of a diphenylmethane diisocyanate-based polyisocyanate, the polyol component (b) is composed of (b1) an N,N,N',N'-tetrakis[hydroxypropyl]ethylenediamine compound and (b2) other polyols and the catalyst (c) is a metallic compound, especially a bismuth-based compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coating agent for a float comprising a two-component solventless urethane resin, and more particularly, a float used for aquaculture, civil engineering, etc. The present invention relates to a coating agent for a float for providing a float having excellent durability and no buoyancy reduction, appearance change, and biological adhesion to the float.

Synthetic resin foams such as foamed polystyrene are often used as floats for aquaculture and civil engineering work, but these foams are weak and cracked due to adhesion of aquatic organisms such as oysters, barnacles and seaweeds. There have been problems such as damage such as cutting or shaving, or damage due to joining with squid or contact with ships. In addition, debris generated due to deterioration over time such as cracking and shaving of floats drifts in the ocean and harms the landscape, and there are also concerns about ecosystem problems.
Therefore, some floats were used by covering them with a bag made of synthetic resin film and tying them with a string, but the workability was poor and the appearance was inferior, and the bag was in close contact with the float. The problem of water entering the gaps and attaching aquatic organisms has not been solved.

As a solution to such a problem, for example, a float that is covered with a heat-shrinkable film by covering a foamed synthetic resin molding with a tube-shaped or bag-shaped heat-shrinkable film, and heat-shrinkable (see, for example, Patent Document 1). ) Or a heat shrinkable cloth sheet in which a polyethylene resin layer is laminated on one or both sides of a woven or knitted fabric using a flat yarn made of polyolefin for warp and / or weft as a base fabric, There has been proposed a float (see, for example, Patent Document 2) obtained by coating a float made of a synthetic resin foam and heating and closely coating.
Japanese Patent Laid-Open No. 6-217661 JP 2000-296872 A

  However, although the float and the heat-shrinkable film or the cross sheet are in close contact with each other in the techniques disclosed in Patent Documents 1 and 2, the buoyancy is greatly reduced or the film or the cross sheet is damaged when used for a long time. Problems such as appearance changes and biofouling on the float remain, and further improvements are required.

  Therefore, in the present invention, under such a background, even when used for a long period of time, there is no decrease in float buoyancy, appearance change, biofouling on the float, and a float coating agent for obtaining a float with excellent durability. Is intended to provide.

  However, as a result of intensive studies in view of such circumstances, the present inventors have determined from a two-component solventless urethane resin [I] comprising a polyisocyanate component (a), a polyol component (b) and a catalyst (c). As a result, the present invention was completed.

  In the present invention, the polyisocyanate component (a) is preferably composed mainly of diphenylmethane diisocyanate polyisocyanate from the viewpoint of the elasticity of the coating film, and the polyol component (b) is N, N, N It is preferable from the viewpoint of maintaining the strength and elongation of the coating film that it is composed of the ', N'-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and the other polyol (b2). It is preferable that c) is made of a bismuth compound in terms of drying property and surface smoothness.

  The float coating agent of the present invention comprises a two-component solventless urethane-based resin [I] comprising a polyisocyanate component (a), a polyol component (b) and a catalyst (c), preferably a polyisocyanate component (a ) Is mainly composed of diphenylmethane diisocyanate polyisocyanate, and the polyol component (b) is N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and other polyols (b2). The catalyst (c) is made of a urethane resin [I-1] made of a metal compound, particularly a bismuth compound, so that even if it is used for a long period of time, the float buoyancy is reduced, the appearance changes, It exhibits an excellent effect of obtaining a float that is free from biological adhesion and excellent in durability.

  The two-component solventless urethane-based resin [I] used in the present invention may be composed of the polyisocyanate component (a), the polyol component (b), and the catalyst (c). (A) is mainly composed of diphenylmethane diisocyanate polyisocyanate, and the polyol component (b) is composed of N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and other polyols ( b2), and the catalyst (c) is a urethane resin [I-1] made of a metal compound, particularly a bismuth compound, in terms of strength and elongation of the coating film, drying property and surface smoothness. It is preferable from the above point.

  As the polyisocyanate component (a), various polyisocyanates used in the production of polyurethane can be used, and among them, those mainly composed of diphenylmethane diisocyanate polyisocyanate are particularly suitable.

  Here, examples of the diphenylmethane diisocyanate-based polyisocyanate are (1) diphenylmethane-4,4′-diisocyanate called pure MDI, (2) polymethylene polyphenyl polyisocyanate called crude MDI or polymeric MDI, ( 3) Dicyclohexylmethane-4,4′-diisocyanate called hydrogenated MDI or H12MDI, (4) one or two of polyisocyanate of (1) to (3) above, carbodiimide, isocyanurate, uretonimine, etc. (5) Modified products of the above-mentioned (1) to (3) MDI polyisocyanate and one or more of biuret, allophanate, etc., (6) (1) to (3 ) Polyisocyanates and hydroxy polyols (polyalkylene glycols, etc.) (7) A polyisocyanate modified from (1) to (3) above, modified with carbodiimide, isocyanurate, uretonimine, etc., and prepolymerized with hydroxy polyol or polyhydric alcohol , Etc. Among these, (1), (4), (6) and (7), particularly (4), (6) and (7) are useful.

  Polyisocyanates other than diphenylmethane diisocyanate polyisocyanates include 2,4- or / and 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, trans Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, tetramethylxylene diisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, 1, Examples include 3,6-hexamethylene triisocyanate and bicycloheptane triisocyanate. However, even when these are used, it is preferable to use a small amount (50% by weight or less, usually 30% by weight or less, and further 20% by weight or less) in combination with diphenylmethane diisocyanate polyisocyanate.

As the polyol component (b), those composed of N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and other polyols (b2) are used.
As the N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1), N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine represented by the following formula (1) is used. As a commercial product, there is “Quadrol” manufactured by Asahi Denka Kogyo Co., Ltd. In addition, compounds represented by the following formula (2) can also be used. (2) Four n in a formula are positive integers (preferably 1-20), and each n may be the same or different.

  As the polyol (b2) other than the N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) among the polyol component (b), various polyols used for the production of polyurethane are used. However, in the polyol (b2), the amount exceeding 50% by weight (preferably 60% by weight or more, more preferably 65% by weight or more, especially 70% by weight or more) is a secondary OH group-containing polyol. It is particularly preferred. The use of the secondary OH group-containing polyol is preferable in terms of mechanical strength, adjustment of curing time, and realization of surface smoothness when applied to the surface of an object.

  As the secondary OH group-containing polyol, a high molecular polyol or a low molecular polyol as exemplified below is used, and it is preferable to use the high molecular polyol in a main ratio.

  Examples of the polymer polyol include polypropylene glycol, polybutylene glycol, castor oil or a derivative thereof, a random or block copolymer of propylene oxide and butylene oxide, a random or propylene oxide end block copolymer of propylene oxide and ethylene oxide, Random or butylene oxide end block copolymer of butylene oxide and ethylene oxide, random or propylene oxide end copolymer of propylene oxide and tetrahydrofuran, random or butylene oxide end copolymer of butylene oxide and tetrahydrofuran, glycerin and tri Polymers obtained by addition polymerization of propylene oxide to chain extenders such as methylolpropane, glycerin and trimethylol A polymer obtained by addition polymerization of butylene oxide to a chain extender such as lopan, a polymer obtained by addition polymerization of propylene oxide or butylene oxide to a chain extender such as glycerin or trimethylolpropane, and the secondary class described later Examples thereof include a polymer obtained by addition polymerization of propylene oxide to a polyol other than the OH group-containing polyol, and a polymer obtained by addition polymerization of butylene oxide to a polyol other than the secondary OH group-containing polyol described below.

  Low molecular polyols include propylene glycol, dipropylene glycol, tripropylene glycol, 2,4-pentanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, and 1,2-cyclohexane. Diol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hexanediol, glycerin, diglycerin, 1,2,6-hexanetriol, sorbitol, triisopropanolamine, phenyldiisopropanol Examples thereof include amines and N, N′-bis (2-hydroxypropyl) aniline.

  As polyols other than the secondary OH group-containing polyol in the polyol (b2), high molecular polyols and low molecular polyols as exemplified below are used.

  As the polymer polyol, polyethylene glycol, polytetramethylene glycol, a copolymer of ethylene oxide and tetrahydrofuran, a polyester polyol such as a condensed polyester polyol / lactone polyester polyol / polycarbonate diol, a primary OH as a chain extender. The thing using the polyol containing only a group, polybutadiene polyol, etc. are mentioned.

  Low molecular polyols include ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-bis ( 2′-hydroxyethoxy) benzene, trimethylolpropane, pentaerythritol, diethanolamine, triethanolamine, phenyldiethanolamine, N, N′-di (2-hydroxyethyl) aniline and the like.

  The proportion of N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) in the polyol component (b) is 5 to 40% by weight (preferably 5 to 30% by weight), otherwise The proportion of the polyol (b2) is desirably 95 to 60% by weight (preferably 95 to 70% by weight). When the proportion of N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) is too small, the coating film is unsatisfactory in terms of strength and hardness when applied to an object, and curing rate. However, there are disadvantages such as being slow, insufficiency in smoothness, and inadequate adhesion to objects. On the other hand, when the ratio of the N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) is too large, the coating when applied to an object becomes hard but brittle, and due to external impact The coating may be damaged.

  The total OH value of the polyol component (b) comprising the N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and the other polyol (b2) is 10 to 380 KOHmg / g, particularly 20 to It is preferable to be within the range of 350 KOHmg / g. This is because when the OH value is in such a range, the physical properties as a coating agent, particularly the elastic modulus of the coating film, is improved, and the balance between strength and elongation is optimal.

  The catalyst (c) is preferably a metal compound, particularly a bismuth compound, specifically, bismuth acetate, bismuth oxalate, bismuth oleate, bismuth valerate, bismastannate, bismuth citrate, bismuth salicylate, Examples include bismuth organic acid salts such as bismuth-2-ethylhexanoate and bismuth neodecanoate, bismuth carbonate, bismuth hydrate, bismuth nitrate, bismuth oxide, bismuth phosphate, and bismuth neodecanoate. Is preferred. The bismuth compound exhibits a synergistic effect with the N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) used as the polyol component (b), and improves smoothness when applied to an object. It is effective in terms of improving adhesion.

  The bismuth-based compound as the catalyst (c) is used in the form of a solution mixed with an appropriate amount of an organic acid (for example, neodecanoic acid) or the like dissolved in a polyol in a single state in order to make it liquid. It is normal.

  Further, as a catalyst other than the bismuth compound, a metal compound such as an organic tin compound and an organic lead compound can be used together with the bismuth compound, and if the amount does not impair the spirit of the present invention, As a catalyst other than the metal compound, for example, a tertiary amine may be used in combination.

  The two-component solventless urethane resin [I-1] includes a chain extender that does not belong to the polyol component in addition to the polyisocyanate component (a), the polyol component (b), and the catalyst (c). (Polyvalent amine or the like) can be blended. The chain extender belonging to the polyol component (b) is classified as the above-described polyol component for convenience.

In the present invention, the two-component solventless urethane resin [I] is a urethane resin comprising a polyisocyanate component (a), a polyol component (b), a catalyst (c) and a crosslinking agent (d). In the polyol component (b), an amount exceeding 50% by weight is composed of the secondary OH group-containing polyol, and the urethane resin [I-2] in which the crosslinking agent (d) is diethyl toluenediamine is used. You can also.
Examples of the polyisocyanate component (a) include the same as the polyisocyanate component (a).

  As the polyol component (b), an amount exceeding 50% by weight (preferably 60% by weight or more, more preferably 70% by weight or more, especially 80% by weight or more, further 90% by weight or more) is a secondary OH group. It is made to comprise with a contained polyol. The use of the secondary OH group-containing polyol is preferable in terms of mechanical strength, adjustment of curing time, and realization of surface smoothness when applied to the surface of an object.

As the secondary OH group-containing polyol, the same polymer polyol and low molecular polyol as those described above are used, and it is preferable to use the polymer polyol in a main ratio.
As the polyol other than the secondary OH group-containing polyol in the polyol component (b), the same polymer polyol and low molecular polyol as those described above are used.

The OH value of the entire polyol component (b) is preferably in the range of 10 to 380 KOHmg / g, particularly 20 to 350 KOHmg / g. This is because when the OH value is in such a range, the physical properties of the coating film, particularly the elastic modulus of the coating film, is improved, and the balance between strength and elongation is optimal.
Examples of the catalyst (c) include the same as the catalyst (c).

  As the crosslinking agent (d), it is preferable to use diethyltoluenediamine, which is a compound represented by the following formula (3).

  Further, as the crosslinking agent (d), an amine other than diethyltoluenediamine may be used in combination as long as it does not impair the spirit of the present invention (for example, 30% by weight or less, particularly 20% by weight or less). .

  In addition to the polyisocyanate component (a), the polyol component (b), the catalyst (c) and the crosslinking agent (d), the two-component solventless urethane resin [I-2] includes a polyol component. A chain extender (such as a polyvalent amine) that does not belong to can be blended. The chain extender belonging to the polyol component is classified as the above-mentioned polyol component (b) for convenience.

Furthermore, in the present invention, the two-component solventless urethane resin [I] is a urethane resin comprising a polyisocyanate component (a), a polyol component (b), a catalyst (c) and a crosslinking agent (d). In the polyol component (b), an amount exceeding 50% by weight is composed of a primary OH group-containing polyol, and the urethane resin [I-3] in which the crosslinking agent (d) is diethyl toluenediamine is used. You can also.
Examples of the polyisocyanate component (a) include the same as the polyisocyanate component (a).

  As the polyol component (b), an amount exceeding 50% by weight (preferably 60% by weight or more, more preferably 70% by weight or more, especially 80% by weight or more) is constituted by the primary OH group-containing polyol. To. The use of the primary OH group-containing polyol is preferable from the viewpoints of appropriate strength and flexibility (elongation, etc.) of the coating when applied to the surface of the object, adjustment of the curing time, and realization of surface smoothness.

The primary OH group-containing polyol has a weight ratio of 6: 4 in terms of a weight ratio of a high OH number polyol having an OH number X exceeding 100 mgKOH / g and a low OH number polyol having an OH number smaller than X. A mixture of ˜9: 1 is preferred. This is because in such a range, a flexible and tough coating film can be obtained.
The OH value X is preferably 110 mgKOH / g or more, more preferably 115 mgKOH / g or more. The upper limit of the OH number X is practically about 140 mgKOH / g.

The OH group-containing polyol includes a primary OH group-containing polyol and a secondary OH group-containing polyol.
As the primary OH group-containing polyol in the polyol component (b), the following polymer polyols and low-molecular polyols are used, and it is preferable to use the polymer polyol in a main ratio.

  As the polymer polyol, polyethylene glycol, polytetramethylene glycol, a copolymer of ethylene oxide and tetrahydrofuran, a polyester polyol such as a condensed polyester polyol / lactone polyester polyol / polycarbonate diol, a primary OH as a chain extender. The thing using the polyol containing only a group, polybutadiene polyol, etc. are mentioned. Moreover, what capped the secondary OH group of polypropylene glycol or polybutylene glycol with ethylene oxide (that is, an ethylene oxide terminal block copolymer) can also be suitably used.

Low molecular polyols include ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-bis ( 2′-hydroxyethoxy) benzene, trimethylolpropane, pentaerythritol, diethanolamine, triethanolamine, phenyldiethanolamine, N, N′-di (2-hydroxyethyl) aniline and the like.
As the secondary OH group-containing polyol, high molecular polyols and low molecular polyols similar to those described above are used.

  The OH value of the entire polyol component (b) is preferably in the range of 10 to 380 KOHmg / g, particularly 20 to 350 KOHmg / g. This is because when the OH value is in such a range, the physical properties of the coating film, particularly the elastic modulus of the coating film, is improved, and the balance between strength and elongation is optimal.

Examples of the catalyst (c) include the same as the catalyst (c).
Examples of the crosslinking agent (d) include those similar to the crosslinking agent (d) described above, and if the amount does not impair the spirit of the present invention (for example, 30% by weight or less, particularly 20% by weight or less). An amine other than diethyltoluenediamine may be used in combination.

  In addition to the polyisocyanate component (a), the polyol component (b), the catalyst (c) and the crosslinking agent (d), the two-component solventless urethane resin [I-3] includes a polyol component. A chain extender (such as a polyvalent amine) that does not belong to can be blended. The chain extender belonging to the polyol component is classified as the above-mentioned polyol component (b) for convenience.

Thus, in preparing the two-component solventless urethane resin [I], the polyisocyanate component (a) is used as the A solution and the polyol component (b) as the B solution, and the catalyst (c), the crosslinking agent (d), the chain is used. The extender is usually blended into the B liquid.
The blending ratio of the polyisocyanate component (a) and the polyol component (b) is such that the equivalent ratio of NCO / active H is 0.9 to 1.3, preferably 1.0 to 1.2. Is appropriate. The active H is H capable of reacting with an NCO group, for example, H of an OH group, H of an NH2 group, H of a COOH group, or the like.

Taking the case of a bismuth compound as an example, the amount of the catalyst (c) is 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the whole polyol component (b). When the ratio is too small, the curing rate, smoothness, adhesion, and coating strength are unsatisfactory. When the ratio is too large, the smoothness and adhesion may be deteriorated.
The amount of the crosslinking agent (d) is 1 to 40% by weight, preferably 5 to 30% by weight, based on the whole polyol component (b). When the proportion is too small, the curing rate In addition, it is unsatisfactory in terms of smoothness and adhesion, and tends to cause a decrease in coating strength. On the other hand, when the ratio is too large, there is a risk that the smoothness and adhesion will be reduced.

Thus, in the present invention, a float coating agent comprising the two-component solventless urethane resin [I] is obtained.
Such float coating agents may include fillers, colorants, plasticizers, oxidation stabilizers, UV absorbers, flame retardants, antistatic agents, hydrolysis inhibitors, antifungal agents, dehydrating agents, and extinguishing agents as necessary. A foaming agent etc. can be mix | blended.

  The float used in the present invention is not particularly limited, but the effect of the present invention is remarkably exhibited when it is made of a synthetic resin foam, and as such a float made of synthetic resin foam, polystyrene, polyethylene, Any foam formed by foaming polypropylene or the like is used, but generally, polystyrene foam made of polystyrene is often used.

As the shape of the float, various shapes such as a cylindrical shape, a disk shape, a square shape, and a spherical shape can be used.
In coating on the float, the thickness of the coating agent layer of the present invention is not particularly limited, but is preferably 0.1 to 20 mm, particularly 0.5 to 10 mm, and more preferably 1 to 5 mm. If the coating agent layer is less than 0.1 mm, the strength is insufficient, and it is difficult to obtain the effect of preventing float breakage, and it is also difficult to obtain a sufficient effect of preventing biological adhesion. If the thickness exceeds 20 mm, the weight increases and the buoyancy decreases, which is preferable. Absent.
The coating of the coating agent of the present invention on the float can be arbitrarily selected, for example, by spraying, pouring, troweling or the like.

The coating agent of the present invention may be applied directly to the float surface, but can also be applied via a primer layer in order to improve adhesion and corrosion resistance. Such a primer layer can be formed by a commonly used primer, but from the viewpoint of heat resistance, a solvent-free or water-based primer of a thermosetting resin is preferable.
In order to further improve the weather resistance, an overcoat layer can be provided on the surface of the coating agent layer of the present invention. Such an overcoat layer can be formed of, for example, an acrylic resin paint, an acrylic-urethane resin paint, a urethane resin paint, a silicon resin paint, a fluorine resin paint, or the like.

  Thus, even if the coating agent for float of the present invention is used for a long period of time, a float excellent in durability can be obtained without lowering the buoyancy of the float, changing its appearance, and attaching organisms to the float.

Hereinafter, the present invention will be described more specifically with reference to examples.
In the examples, “%” and “parts” are based on weight unless otherwise specified.

[Preparation of solution A]
35 parts of diphenylmethane-4,4′-diisocyanate (pure MDI) was melted in a nitrogen stream at a temperature of 80 ° C., prepolymerized with 24 parts of polypropylene glycol having a molecular weight of 700, reacted for 2 hours, and then modified with carbodiimide. 41 parts of the body (“Coronate 84” manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to obtain a prepolymer having a free NCO% of 21.0. This was used as the polyisocyanate component (a).

[Preparation of solution B]
N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine (“Quodorol” manufactured by Asahi Denka Kogyo Co., Ltd.) as N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) ) 23 parts, 64 parts of a polypropylene glycol ("Adeka Polyether P-1000" manufactured by Asahi Denka Kogyo Co., Ltd.) having a molecular weight of 1000 as the other polyol (b2) and a polyether polyol (OH value is 33 KOHmg / g) 7 parts of polyoxypropylene-polyoxyethylene block copolymer having a polyoxypropylene unit in), 5 parts of 1,4-butanediol as polyol (b2) which is also a chain extender, and bismuth as catalyst (c) Neodecanoate in neodecanoic acid (bismuth content is 16% by weight) 1.0 part was mixed and it was set as B liquid.

Next, using a spray device “QSP-26” manufactured by Nippon Synthetic Chemical Industry Co., Ltd., the above-mentioned B liquid together with A liquid (volume ratio of A liquid and B liquid is 1: 1) and foamed polystyrene (foaming ratio 50) 2 times) cylindrical float (No. 2 float: 700 mm in diameter, 1100 liters in capacity) (Toyo Float manufactured by Toyo Cork Co., Ltd.) and aged for 24 hours to form a coating agent layer with a thickness of 1 mm Thus, the float (1) was produced.
The following evaluation was performed about the obtained float (1).

(Appearance change)
The obtained float (1) was floated on the sea, and the appearance change was visually observed over time (after 3 months, 6 months, 9 months, and 1 year).
(buoyancy)
The obtained float (1) was floated on the sea, and its buoyancy was measured over time (after 3 months, 6 months, 9 months and 1 year). The initial buoyancy was 450 kg.
(Biological status)
The obtained float (1) was floated on the sea, and the state of biological adhesion was visually observed over time (after 3 months, 6 months, 9 months, and 1 year).
(durability)
Join the wood in a lattice shape to make a squid, connect the float (1) to the joint, float it in the sea, and contact the joint between the squid wood and the float (1) or ship The durability of the peripheral part, which is expected to be observed, was visually observed over time (after 3 months, 6 months, 9 months, and 1 year).

[Preparation of solution A]
The same one as in Example 1 was used.
[Preparation of solution B]
N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine (“Quodorol” manufactured by Asahi Denka Kogyo Co., Ltd.) as N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) ) 23 parts, 52 parts of a propylene oxide-tetrahydrofuran random copolymer ("PPTG1000" manufactured by Hodogaya Chemical Co., Ltd.) as a polyol (b2) other than that and polyether polyol (manufactured by Sanyo Chemical Industries, Ltd.) "Sanniks PP-1200") 19 parts, 5 parts of 1,4-butanediol as polyol (b2), which is also a chain extender, and a neodecanoic acid solution of bismuth neodecanoate (bismuth) as catalyst (c) The ratio was 16% by weight.

Next, in the same manner as in Example 1, using the spray device “QSP-26” manufactured by Nippon Synthetic Chemical Industry Co., Ltd., the above solution B together with solution A (volume ratio of solution A and solution B is 1: 1) A cylindrical float (No. 2 float: diameter 700 mm, capacity 1100 liters) made of expanded polystyrene (expanding ratio 50 times) (Toyo Float manufactured by Toyo Cork Co., Ltd.), aged for 24 hours, thickness A coating agent layer having a thickness of 1.0 mm was formed to produce float (2).
About the obtained float (2), evaluation similar to Example 1 was performed.

Comparative Example 1

  A cylindrical float (No. 2 float: diameter 700 mm, capacity 1100 liters) made of expanded polystyrene (expanding ratio 50 times) was used as it was, and the same evaluation as in Example 1 was performed.

Comparative Example 2

The same evaluation as in Example 1 was performed using a cylindrical float (No. 2 float: diameter 700 mm, capacity 1100 liters) made of expanded polystyrene (expanding ratio 50 times) covered with a polyethylene bag. It was.
The evaluation results of Examples and Comparative Examples are shown in Table 1 and Table 2.

  A float used for aquaculture, civil engineering, etc., to provide a float with excellent durability even when used for a long period of time, with no buoyancy reduction or change in appearance of the float, biological attachment to the float Useful for coating agents for floats.

Claims (7)

  A coating agent for a float, comprising a two-component solventless urethane resin [I] comprising a polyisocyanate component (a), a polyol component (b) and a catalyst (c).   The float coating composition according to claim 1, wherein the polyisocyanate component (a) is mainly composed of diphenylmethane diisocyanate polyisocyanate.   2. The polyol component (b) comprises N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) and other polyol (b2). Or the coating agent for floats of 2 description.   The coating agent for float according to claim 3, wherein the amount exceeding 50% by weight of the polyol (b2) in the polyol component (b) is a secondary OH group-containing polyol.   The proportion of N, N, N ′, N′-tetrakis [hydroxypropyl] ethylenediamine compound (b1) in the polyol component (b) is 5 to 40% by weight, and the proportion of the other polyol (b2) is 95%. The float coating composition according to claim 3 or 4, characterized in that it is -60 wt%.   The coating agent for float according to any one of claims 1 to 5, wherein the catalyst (c) comprises a bismuth compound.   The coating agent for float according to any one of claims 1 to 6, which is applied to a float made of foamed polystyrene.