JPH04269537A - Antistaining lining - Google Patents

Abstract

PURPOSE:To continue antistaining effect by replenishing a highly water- absorbable substance from the interior of a lining to the surface thereof. CONSTITUTION:In applying an antistaining lining utilizing a highly water- absorbable substance to the surface of the structure being in contact with seawater, the lining is constituted of a laminate consisting of a layer (waterproof layer) containing no highly water-absorbable substance, a layer (intermediate layer) containing a large amount of the highly water-absorbable substance and a layer (water contact layer) containing a small amount of said substance.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to offshore structures,
This invention relates to an antifouling lining that provides an antifouling structure that is free from environmental pollution in antifouling treatments that prevent aquatic organisms from attaching and growing on ships, piping, waterways, etc.

0002

BACKGROUND OF THE INVENTION Paints in which substances toxic to aquatic organisms, such as copper compounds and organic tin compounds, are dispersed as antifouling agents are used for antifouling of ships and marine structures. However, the use of these paints is being restricted because they pollute the ocean.

[0003] As a pollution-free antifouling means that does not pollute the environment,
A technique was disclosed in which a structure is lined with an antifouling sheet formed by uniformly dispersing superabsorbent resin in rubber or synthetic resin, by nailing or gluing it (Japanese Patent Laid-Open No. 61-611).
No. 2529). This antifouling lining is effective because
It is based on the following mechanism. In other words, marine organisms such as barnacles and mussels attach to structures because the proteins secreted by the organisms have adhesive properties, but if superabsorbent resin is present on the surface of the structure, The movement of water into and out of the surface layer and the movement of molecules of water retained on the surface create a liquid lubrication effect on the surface, which reduces the adhesive force of proteins.

However, when the above-mentioned antifouling sheet is continuously immersed in seawater, the superabsorbent resin swells, and the rubber or synthetic resin present in a matrix is compressed by this swelling. As a result of this pressure being created within the matrix,
The water-absorbing resin is extruded and detached from the antifouling sheet, and the antifouling effect gradually decreases.

[0005] Even if the content of the superabsorbent resin is increased in order to improve the sustainability of the antifouling effect, the strength of the antifouling sheet and the ability to retain the superabsorbent resin decrease accordingly, and the result is not as good as expected. No effect will be obtained.

[0006]

[Problems to be Solved by the Invention] An object of the present invention is to provide an antifouling lining that prevents the attachment of marine organisms without releasing harmful substances into the ocean, and that maintains the effect of preventing attachment of organisms for a long period of time. There is a particular thing.

[0007]

[Means for Solving the Problems] As shown in FIG. 1, the antifouling lining of the present invention has a structure (6
) is a lining made mainly of rubber or synthetic resin applied to the surface of the structure, in which the lining (1) is, in order from the surface of the structure, a waterproof layer (2) that does not contain a superabsorbent substance, and a large amount of a superabsorbent substance. and a water contact layer (4) containing a small amount of super absorbent material.

[0008] Structures to be lined according to the present invention are all structures that can be lined, such as steel, wood, and concrete, which require prevention of marine organisms from adhering to them.

The material used for the lining is selected from among the following rubbers and synthetic resins, taking into account the workability of the lining and the adhesion between the lining layer and the structure depending on the structure to be antifouled. Choose the appropriate one. That is, when the surface to be lined is already rubber-lined or is a steel or concrete surface, rubber lining is suitable because the lining work is relatively easy. When the surface to be lined is lined with a resin such as polyethylene, resin lining using the same type of resin is preferred. The structure is FRP
If it is made of rubber, you can choose either a rubber lining or a resin lining.

Rubbers used for the rubber lining include natural rubber, chloroprene rubber, styrene-butadiene rubber, nitrile rubber, butyl rubber, ethylene propylene rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber,
Any known material such as urethane rubber may be used.

[0011] For the resin lining, soft resins such as vinyl chloride resin, vinyl acetate resin, acrylic resin, urethane resin, silicone, polyamide, and polyethylene are usually used, and in the present invention, a soft resin may be selected from among them.

The superabsorbent material used in the present invention is not particularly limited, but representative examples include vinyl alcohol/acrylate copolymer, polyacrylonitrile hydrolyzate, crosslinked polyacrylate, These include highly absorbent polymers such as modified polyvinyl alcohol, crosslinked carboxymethyl cellulose, and graft polymers of starch and acrylate, and natural hydrophilic polymer substances such as gelatin and agar. The superabsorbent substance is used in the form of particles of an appropriate diameter.

The content of the highly water-absorbent substance is 20 to 100 parts by weight, particularly 30 to 50 parts by weight, in the intermediate layer, and 1 to 100 parts by weight in the water contact layer, per 100 parts by weight of the rubber or synthetic resin.
A range of from 5 to 10 parts by weight is suitable, in particular from 5 to 10 parts by weight.

[0014] In order to improve strength and other physical properties,
As with conventional linings, suitable fillers may be added to the rubber or synthetic resin.

Although the thickness of the lining depends on the environment around the structure, a total thickness of about 3 mm is sufficient. The thickness of the water contact layer is preferably 1 mm or less.

[0016] Formation of the lining can be carried out by known methods. For example, in the case of rubber lining, you can either laminate each rubber sheet for the waterproof layer, intermediate layer, and water contact layer on the structure in order, or prepare a laminate of each rubber sheet in advance and paste it. . The lining using a thermoplastic resin may be formed by a sheet lining method or the powder lining method, and the lining using a thermosetting resin may be formed by repeatedly applying a resin composition.

As shown in FIG.
It is preferable that there is no interface between the waterproof layer (2) and the waterproof layer (2), that is, the layers are sufficiently fused and integrated.

[0018] Such a lining can be produced by laminating and vulcanizing each rubber sheet if rubber is used, or by heating and pressing the laminated resin sheets with a calender roll if a thermoplastic resin is used. When a thermosetting resin is used, each of these can be achieved by overcoating the resin composition before the underlying resin layer is completely cured.

[0019]

[Function] The antifouling lining of the present invention has two layers with different contents of highly water-absorbing substances, and the content is lower on the side that comes in contact with seawater, and higher on the inside, so it is antifouling with the following mechanism. Long-lasting effect. In other words, when the antifouling structure is immersed in seawater, the water-absorbing substance on the surface of the layer in contact with water (low content layer) acts as an antifouling agent, but these particles swell and become swollen due to the pressure generated in the matrix. Some of it is pushed out to the seawater side. When the water-absorbing substance falls off from the water-contacting layer, the area becomes a dent, and seawater enters the dent and swells the water-absorbing substance particles present inside the dent. Particles of this water-absorbing material bulge out near the surface of the lining through the holes where seawater has entered, and act as an antifouling agent. The water-absorbing material particles remain effective for a relatively long period of time, since the pressure build-up within the matrix is alleviated by the swelling. Since the amount of water that passes through the rubber or synthetic resin matrix is small, the swelling of the superabsorbent material in the deeper layer only progresses slowly. However, over a long period of time, water gradually enters the material, reaches the highly water-absorbent material present in a relatively high amount on the back side of the water-contacted layer, and gradually swells it. The highly water-absorbent material is pushed outward little by little through the holes created in the water-contact layer, so even if the water-absorbent material is detached from the lining surface, water-absorbent material is immediately replenished from the middle layer. and its abundance in the surface layer is maintained. As a result, biofouling on the surface can be prevented.

[0020] The number of holes formed in the water-contact layer was small compared to the amount of water-absorbing material contained in the intermediate layer, since the content of the water-absorbing substance was small. The movement of water-absorbing substances to the surface layer is gradual. In this way, the antifouling effect is maintained.

[0021] The existence of a waterproof layer that does not contain a water-absorbing substance between the layer containing a water-absorbing substance and the structure prevents seawater from coming into contact with the structure through the lining layer, and has an anticorrosion effect. ensure that

[0022] A lining in which the water-contact layer, intermediate layer, and waterproof layer are sufficiently fused has less risk of the intermediate layer and water-contact layer peeling off from the waterproof layer due to volumetric expansion of the intermediate layer, and provides reliable stain resistance. have an effect.

[0023]

[Example] Using a rubber kneading roll, rubber kneaded products having the following three types of compositions were prepared. Kneaded products A, B and C
are those with low, high, and no superabsorbent substances, respectively.
A B
C Chloroprene rubber 100 parts 100 parts
100 parts lead red
10 copies 10 copies
10 parts stearic acid
0.5 part 0.5 part
0.5 part process oil
10 parts 10 parts 1
Part 0 carbon black
30 copies 20 copies 30 copies
clay
20 copies 10 copies 30
Part Acrylic acid/vinyl
Alcohol copolymer 10 parts
40 copies -
(Super absorbent resin) Kneaded products A, B, and C were each formed into sheets with a thickness of 1.0 mm using an extruder, and then laminated using a pressure roll.

This laminated sheet was lined on the inner surface of a steel pipe with flanges at both ends (diameter: 100 mm, length: 1 m) and vulcanized in an oven to obtain the antifouling structure of the present invention.
The thickness of the lining layer is 3mm.

As Comparative Example 1, a rubber sheet of Kneaded Product C was used to line the inner surface of a steel piece with flanges at both ends having the same size as above and vulcanize it to produce a lining layer of the same thickness.

As Comparative Example 2, a lining layer was provided on the inner surface of the steel pipe in the same manner as described above, except that a laminated sheet in which two rubber sheets of kneaded product B were laminated on a rubber sheet of kneaded product C was used. A dirty structure was fabricated.

The steel pipes of the above embodiment of the present invention, Comparative Example 1, and Comparative Example 2 were installed in the same seawater intake pipe, and the adhesion status of marine organisms was examined.

[0028] On the inner surface of the steel pipe of Comparative Example 1, adhesion of barnacles, snails, etc. was observed from the first month, and the entire surface of the lining layer was covered with marine organisms after the third month. On the inner surface of the steel pipe of Comparative Example 2, adhesion of barnacles and staghorn worms was observed four months after the start of the test.
After six months, approximately 30% of the surface of the lining layer was covered with marine life.

No marine organisms were found attached to the inner surface of the steel pipe of the example even after 6 months had passed.

[0030]

Effects of the Invention The antifouling lining of the present invention prevents marine organisms from adhering to marine structures for a long period of time without contaminating seawater. It also has high corrosion resistance to protect structures from seawater corrosion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view for explaining an example of a structure provided with an antifouling lining of the present invention.

FIG. 2 is an enlarged sectional view for explaining a preferred embodiment of the antifouling lining of the present invention.

[Explanation of symbols]

1. Antifouling lining 2 Waterproof layer 3 Middle class 4 Water contact layer 6 Structure 7 Seawater

Claims (3)

[Claims] Claim 1: A lining made mainly of rubber or synthetic resin applied to the surface of a structure in contact with seawater, the lining comprising, in order from the surface of the structure, a waterproof layer that does not contain a highly absorbent substance, a highly absorbent an intermediate layer containing a large amount of substance;
and an antifouling lining consisting of a water-contact layer containing a small amount of highly water-absorbent substances. 2. The intermediate layer contains 20 to 100 parts by weight of a highly water-absorbent substance per 100 parts by weight of rubber or resin, and the water-contact layer contains a highly water-absorbent material per 100 parts by weight of rubber or synthetic resin. The antifouling lining according to claim 1, which contains 1 to 20 parts by weight of the substance. 3. The antifouling structure of claim 1, wherein the layers forming the lining layer are fully fused.