JPH1034077A - Lining structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of blisters in a polyurethane layer by forming a first glass flake lining layer on the surface of a metal base body, forming a polyurethane layer containing glass flakes, and then forming a second glass flake lining layer. SOLUTION: A glass flake lining material prepared by dispersing glass flakes in a resin component such as an unsatd. polyester resin, vinylester resin, etc., is applied on an iron plate by using a blade to form a first glass flake lining layer. Then the iron plate is dipped in hot water to accelerate deterioration of the glass flake lining layer. The plate is dried under natural conditions, and a compsn. prepared by compounding polyol, polyisocyanate, glass flakes, etc., is applied on the first layer to form a polyurethane layer containing glass flakes. Then the same glass flake lining material used for the first lining is applied on the polyurethane layer to form a second glass flake lining layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lining structure having a lining layer containing glass flakes formed on a metal substrate.

[0002]

2. Description of the Related Art For the purpose of preventing corrosion of metals, resin linings are applied to tanks, ship bottoms, exhaust ducts, etc., mainly for various chemical and environmental devices. The resin lining uses an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, or the like as a coating film forming component in terms of room temperature curability, cost, and workability. As the resin lining, there are an FRP lining using glass fiber as a reinforcing material of a coating film, and a glass flare lining in which flaky glass flakes are dispersed in the coating film. Above all, in the glass flake lining, since scale-like glass flakes are present in the lining layer in a direction parallel to the surface, the permeation of corrosive substances is significantly delayed, and excellent corrosion resistance is exhibited.

[0003]

Generally, the use of a resin lining also deteriorates the lining layer and causes defects such as blistering and cracking. In such a state, repair is necessary, and the lining material of the same kind is usually overcoated. However, when a glass flare lining material is applied directly on the deteriorated glass flare lining layer, delamination tends to occur. Therefore, when a second glass flare lining layer was formed on the deteriorated glass flare lining layer via a polyurethane layer, immediately after forming the second glass flare lining layer, the second glass flare lining layer was attached. Although the adhesion was good, there was a drawback that blisters were easily generated from the polyurethane layer at an early stage. The present invention relates to a lining structure formed by forming a second glass flare lining layer via a polyurethane layer on a first glass flare lining layer formed on the surface of a metal substrate, and prevents blistering from the polyurethane layer. An object of the present invention is to provide a suppressed lining structure.

[0004]

Means for Solving the Problems The present inventors have conducted various studies on means for suppressing the occurrence of blisters from the polyurethane layer, and have reached the present invention.

[0005] The present invention is a lining structure in which a second glass flare lining layer is formed on a first glass flare lining layer formed on the surface of a metal substrate via a polyurethane layer containing glass flakes. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, a resin lining is mainly provided on a metal substrate surface such as a steel plate or a steel pipe used for a tank, a ship bottom, an exhaust duct, etc., mainly for various chemical devices and environmental devices. Therefore, the target for forming the lining layer is often large,
As the resin component for forming the coating film of the lining layer, an unsaturated polyester resin or a vinyl ester resin is used, and the resin component for forming the coating film is often cured at room temperature.

[0007] The first and second glass flaking layers are made of an unsaturated polyester resin, a vinyl ester resin or the like as a resin component for forming a coating film (hereinafter simply referred to as a resin component), and a glass flake dispersed in the resin component. It is formed by applying a flaking material to the surface of a metal substrate and curing a resin component. In addition to the resin component and glass flake, a polymerizable monomer for crosslinking the resin component is required. In addition, a thixotropic material, a curing agent, a curing accelerator, a pigment, a filler, an antifoaming agent, a reinforcing fiber, and the like are added as necessary.

[0008] The unsaturated polyester resin is obtained by reacting an unsaturated polybasic acid with a polyhydric alcohol. Usually, unsaturated polybasic acids include α, β-unsaturated dibasic acids and / or
Alternatively, an acid anhydride thereof is used. An unsaturated polybasic acid and a saturated polybasic acid may be used in combination. When a saturated polybasic acid is used in combination, the content of the unsaturated polybasic acid is preferably 100 to 20 mol%, and the content of the unsaturated polybasic acid is preferably 90 to 3 mol%.
More preferably, it is 0 mol%.

The α, β-unsaturated dibasic acid and / or acid anhydride used herein includes maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride and the like. The above may be used in combination. As the saturated polybasic acid used in combination, phthalic acid, phthalic anhydride,
Trimellitic anhydride, succinic acid, azelaic acid, adipic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, rosin-maleic anhydride adducts, and the like, and these are two or more types. May be used in combination.

As polyhydric alcohols, ethylene glycol, diethylene glycol, propylene glycol,
Dipropylene glycol, 1,3-butanediol,
1,6-hexanediol, neopentyl glycol,
Examples include 1,4-cyclohexanediol, dihydric alcohols such as hydrogenated bisphenol A, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. These may be used in combination of two or more. Good. The acid and the alcohol are preferably blended so that the equivalent ratio of hydroxyl group / carboxyl group is 1.5 to 0.7, more preferably 1.2 to 0.9. .

Since the synthesis of the unsaturated polyester resin is a condensation reaction between an acid component and an alcohol component, a system in which the acid component and the alcohol component are mixed is heated, and nitrogen and carbon dioxide are added to prevent side reactions due to oxidation. The process proceeds while passing an inert gas such as carbon and distilling water and other low-molecular compounds generated by the reaction out of the system. Distillation of water and other low-molecular compounds out of the system is performed by natural distillation by passing an inert gas or vacuum distillation. In order to promote the distillation, a solvent such as toluene or xylene can be added to the system as an azeotropic component. The reaction temperature is preferably set to 150 ° C. or higher.
As the reaction apparatus, those made of glass, stainless steel, etc. are selected, a stirring apparatus, a fractionating apparatus for preventing water and an alcohol component from azeotropically evaporating the alcohol component, and a heating device for increasing the temperature of the reaction system It is preferable to use a reactor equipped with a temperature controller for the heating device, a device for blowing an inert gas such as nitrogen, and the like. In general, the degree of progress of the reaction can be known by measuring the amount of distillate generated by the reaction, quantifying the terminal functional group, measuring the viscosity of the reaction system, and the like.

The vinyl ester resin is obtained by reacting an epoxy resin with an unsaturated monobasic acid. In addition to the unsaturated monobasic acid, if necessary, a polybasic acid may be used in combination.

The epoxy resin used here is not particularly limited as long as it is a bifunctional or higher epoxy resin.
Examples of the bifunctional or higher epoxy resin include a bisphenol epoxy resin and a novolak epoxy resin.

As the bisphenol-based epoxy resin,
Yuko Shell Epoxy Co., Ltd., Epikote 828, Epikote 1001, Epikote 1004,
AER-664H, AER-331, AER-33, commercially available from Asahi Kasei Corporation
7, which is commercially available from Dow Chemical Company. E. FIG. R. 330, D.I. E. FIG. R. 660, D.E.
E. FIG. R. 664 and the like.

As a novolak-based epoxy resin, Epicoat 1 commercially available from Yuka Shell Epoxy Co., Ltd.
52, Epicoat 154, commercially available from Ciba, EPN11338, commercially available from Dow Chemical Company; E. FIG. N. 43
1, D. E. FIG. N. 438, and the like.

As unsaturated monobasic acids to be reacted with these epoxy resins, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, tricyclo [5.2.1.0 ^2,6 ]-
A partially esterified carboxylic acid containing 4-decene-8 or 9 residues and an unsaturated dibasic acid residue as constituents can be used. Examples of partially esterified carboxylic acids include 8 or 9-hydroxytricyclodecene-4-
[5.2.1.0 ^2,6 ] and 1.00 to 1.20 mol of an unsaturated dibasic acid such as maleic anhydride, itaconic acid and citraconic acid in an inert gas stream at 70 to 1.20 mol. 150
There is an unsaturated dibasic acid monoester obtained by heating at ° C. The unsaturated monobasic acid is preferably blended so that the ratio of epoxy group / carboxyl group is 1.5 to 0.6 in equivalent ratio, and is adjusted to be 1.2 to 0.9. Is more preferred.

The polybasic acids to be reacted as required include phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, glutaric acid, adipic acid, Sebacic acid, trimellitic acid, pyromellitic acid, dimer acid, maleic anhydride, fumaric acid and the like can be mentioned. The amount of the polybasic acid used is preferably 1 to 20 mol%, more preferably 2 to 10 mol%, based on the hydroxyl groups of the vinyl ester resin.

The epoxy resin is reacted with the unsaturated monobasic acid and, if necessary, the polybasic acid at a temperature of 60 to 150 ° C., preferably 70 to 130 ° C., to obtain a vinyl ester resin.

Examples of the polymerizable monomer for crosslinking the resin component include styrene, chlorostyrene, divinylbenzene, tertiarybutylstyrene, styrene bromide, diallyl phthalate, methyl methacrylate, ethyl methacrylate, and acrylic acid. Ethyl, butyl acrylate,
Ethyl β-hydroxymethacrylate, ethyl β-hydroxyacrylate, acrylamide, phenylmaleimide and the like are used. Also, ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate,
Polyfunctional (meth) acrylates such as trimethylolpropane trimethacrylate can also be used. These are used alone or in combination with other polymerizable monomers. The amount is preferably 10 to 200 parts by weight, and more preferably 30 to 15 parts by weight, per 100 parts by weight of the resin component.
0 parts by weight is more preferred.

Glass flakes are flat glass materials. The average thickness of the glass flakes is preferably 0.5 to 10 μm, and particularly preferably 3 to 5 μm. The average size of the glass flakes is 100
To 4000 μm, particularly preferably 150 to 3 μm.
It is preferably 00 μm. Because this glass flake is oriented in parallel in the coating film and laminated in layers,
It has the effect of improving the strength of the coating film and delaying the transmission of vapor, moisture and other corrosive substances from the outside. Here, the size of the glass flake is defined as the diameter of the largest circumscribed circle of the glass flake. If the thickness of the glass flakes is too small, the strength of the flakes is weak and breakage occurs when mixed with the resin.If the thickness is too large, the number of parallel-oriented layers in the coating film decreases, and external steam, moisture and other corrosion occur. The effect of blocking the permeation of the conductive material is reduced. If the size of the glass flakes is less than 100 μm, it is difficult to orient parallel to the surface of the metal substrate. If the size exceeds 4000 μm, mixing with the resin becomes difficult, and the wettability between the surface of the glass flakes and the resin deteriorates. As glass flakes, RCF-600, RCF-140, RC from Nippon Glass Fiber Co., Ltd.
F-015, REF-600, REF-140 and RE
Examples include those commercially available under the trade name of F-015 and under the trade name of GF-Cl50 from Asahi Fiberglass Corporation.

The amount of the glass flake is preferably 10 to 60 parts by weight, more preferably 30 to 50 parts by weight, based on 100 parts by weight of the total of the resin component and the polymerizable monomer. If the amount is too small, vapor, moisture and other corrosive substances cannot be prevented from penetrating from the outside, and if the amount is too large, the flexibility of the coating film is reduced and the adhesion to the metal substrate surface is poor. It causes blistering.

As the curing agent, peroxides such as methyl ethyl ketone peroxide, acetylacetone peroxide, isobutyl methyl ketone peroxide, cumene hydroperoxide, benzoyl peroxide, t-butyl perbenzoate and t-butyl hydroperoxide are used. Is done. The amount of the curing agent is preferably from 0.4 to 3.0 parts by weight, more preferably from 0.6 to 2.0 parts by weight, based on 100 parts by weight of the total amount of the resin component and the polymerizable monomer.

As the curing accelerator, it is preferable to use cobalt octenoate or cobalt naphthenate. The compounding amount is preferably 0.1 to 2 parts by weight, preferably 0.3 to 1.0 part by weight based on 100 parts by weight of the total amount of the resin component and the polymerizable monomer.
Part by weight is more preferred. Further, it is preferable to mix dimethylaniline, diethylaniline, N, N-dimethylparatoluidine, acetylacetone, ethyl acetoacetate and the like as a co-promoter. The compounding amount is 0.01 to 100 parts by weight of the total amount of the resin component and the polymerizable monomer.
1.0 part by weight is preferable, and 0.05 to 0.3 part by weight is more preferable.

Examples of the thixotropic material to be blended if necessary include fumed silica and organic bentonite, and are used in the range of 0.5 to 10% by weight based on the total amount of the resin component and the polymerizable monomer. Is preferably performed.

As the filler, fillers such as calcium carbonate, barium hydroxide, aluminum hydroxide, talc and glass powder, and pigments can be added.
Further, a silane coupling agent or the like can be added for improving the coupling between the glass flake and the unsaturated polyester resin or the vinyl ester resin and the filler.

In addition, pigments, defoamers, reinforcing fibers and the like are appropriately compounded.

The polyurethane layer containing the glass flakes formed on the first glass flake reclining layer contains a polyol, a polyisocyanate, a glass flake and a reaction catalyst, and, if necessary, further contains a pigment, a filler, It is formed by applying a composition containing an antifoaming agent, a foam inhibitor, a reinforcing fiber and the like, and reacting a polyol with a polyisocyanate.

Examples of the polyisocyanate include diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. A low-molecular or high-molecular NCO-terminated prepolymer derived from the above is used.

As the polyol, a polyol usually used for polyurethane can be used. Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, hexanetriol, triethanolamine,
Examples thereof include diglycerin, pentaerythritol, ethylenediamine, methylglucose, aromatic diamine, sorbitol, and sugar. Further, those obtained by subjecting ethylene oxide, propylene oxide, or the like to addition polymerization in the presence of an alkali catalyst using a low molecular weight polyhydric alcohol or polyamine as a starting material can be used. It is preferable that the number of terminal hydroxyl groups in the molecule is 1.5 or more on average and the number average molecular weight is 2000 or less, and the number of terminal hydroxyl groups in the molecule is 2 or more on average and 1000 or less in number average. preferable. In addition, polytetramethylene ether glycol, polyester polyol and the like may be used in combination. Here, the number average molecular weight is determined by gel permeation chromatography in terms of standard polystyrene.

The reaction catalyst is blended for accelerating curing. As the reaction catalyst, those used for producing ordinary polyurethane can be used, and tin compounds such as dibutyltin laurate and dibutyltin octoate, triethylamine, triethylenediamine, triethanolamine, 2-dimethylamino-2-methyl- An amine compound such as 1-propanol is used alone or in combination.
The blending amount of the reaction catalyst is determined by the required pot life, but is preferably 0.02 to 2.0 parts by weight based on 100 parts by weight of the total of polyol and polyisocyanate.

The glass flakes contained in the polyurethane layer are the same as those used for forming the first and second glass flake reclining layers. The same applies to pigments, fillers, defoamers, foam inhibitors, reinforcing fibers, and the like, if necessary. The amount of the glass flakes contained in the polyurethane layer is 10 to 6 with respect to 100 parts by weight of the total amount of the polyol and the polyisocyanate.
0 parts by weight is preferred. If the amount is too small, the penetration of steam, moisture and other corrosive substances from the outside cannot be prevented, and if the amount is too large, the flexibility of the coating film decreases and the followability with the glass flare lining layer tends to be poor. It is in.

Next, the thickness of each layer will be described. The glass flare lining layer has a thickness of 0.1 mm from the viewpoint of corrosion resistance.
It is preferable to be applied to 2 to 2.0 mm,
The polyurethane layer containing glass flakes has a thickness of 0.2-1.
Preferably, it is applied to a thickness of 0 mm. If this layer is too thin, the adhesiveness is reduced, and if it is too thick, foaming tends to occur.

[0033]

The present invention will be described below with reference to examples. In the examples, “part” means “part by weight” and “%” means “% by weight”.

Example 1 Preparation of styrene solution of vinyl ester resin 150 parts of bisphenol epoxy resin (13 parts of Epicoat 828 (trade name, epoxy equivalent: 189) manufactured by Yuka Shell Epoxy Co., Ltd.) and Epicoat 1001 (trade name, epoxy equivalent of 470) ) 150 in total of 137 parts
Parts), 29 parts of methacrylic acid, 0.8 parts of trimethylbenzylammonium chloride, and 0.04 parts of hydroquinone were charged into a flask, reacted at 120 ° C., and dissolved in 1100 parts of styrene when the acid value reached 7.

Vinyl ester resin styrene solution 100
Parts, 0.5 part of 6% cobalt octenoate solution, 0.1 part of N, N-dimethylparatoluidine, 0.04 part of methylhydroquinone, fumed silica (using Aerosil 200 (trade name) manufactured by Nippon Aerosil Co., Ltd.) did)
4 parts, 0.2 parts of surfactant (using Rhodol TW-L120 (trade name) manufactured by Kao Atlas Co., Ltd.) and glass flakes having an average size of 140 μm (RCF-140 manufactured by Nippon Glass Fiber Co., Ltd. Product name)
Forty parts were thoroughly stirred and dispersed by a stirrer, and 2 parts of a 55% methyl ethyl ketone peroxide DMP solution was blended.
The obtained composition was applied to a 70 mm square, 3 mm thick iron plate with a spatula so as to have a thickness of about 1 mm, and allowed to stand for one day to obtain a test piece on which a first glass flare lining layer was formed. Next, the test piece was immersed in warm water at 90 ° C. for 7 days to accelerate and deteriorate the first glass flaking layer. Then, it was air-dried and the surface of the first glass flare lining layer was roughened with # 150 sandpaper. Separately, 45 parts of diphenylmethane diisocyanate,
Pentaerythritol-based polyol (using Sannics EP-560 (trade name) manufactured by Sanyo Chemical Co., Ltd.)
25 parts and 30 parts of glass flakes (using the same RCF-140 as the first glass flaking layer) were stirred, and then 0.6 parts of dibutyltin laurylate was mixed and dispersed. This composition was applied to the roughened test piece so as to have a thickness of about 0.2 mm, and allowed to stand for one day to obtain a test piece on which a polyurethane layer containing glass flakes was formed. Next, on the polyurethane layer containing the glass flakes, the composition used for forming the first glass flake lining layer is applied so as to have a thickness of about 1 mm, and left for one day to form the second glass flakes. A test piece having a lining layer was prepared. In addition, six test pieces were prepared, five were used for measuring the adhesion strength, and the other one was used for the boiling test.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 except that glass flakes in the polyurethane layer were not added.

Comparative Example 2 A test piece was prepared in the same manner as in Example 1 except that the second glass flaking layer was formed directly on the first glass flaking layer without forming the polyurethane layer.

Example 2 Preparation of Styrene Solution of Unsaturated Polyester Resin 75 parts of propylene glycol and 74 parts of isophthalic acid were charged into a flask and reacted at 190 ° C. until the acid value reached 10, and 1.8 parts of hydroquinone and propylene glycol were added. 18 parts and 64 parts of maleic anhydride were added and reacted at 220 ° C. until the acid value reached 17, and then 90 parts of styrene were added. 100 parts of a styrene solution of an unsaturated polyester resin,
Fumed silica (the same as in Example 1 was used) 2
Parts and 40 parts of glass flakes (using the same one as in Example 1) were sufficiently stirred and dispersed with a stirrer, and 1.4 parts of a 55% methyl ethyl ketone peroxide solution (using the same one as in Example 1) was blended. . A test piece was prepared in the same manner as in Example 1 except that this composition was used for forming the first and second glass flaking layers.

Comparative Example 3 A test piece was prepared in the same manner as in Example 2 except that glass flakes in the polyurethane layer were not added.

Comparative Example 4 A test piece was prepared in the same manner as in Example 2 except that no polyurethane layer was formed.

The obtained test piece was subjected to JIS K5
The adhesive strength of the lining layer was measured according to the 400 Paint General Test Method. Further, the end of the test piece was sealed with the composition used for forming the first and second glass flaking layers, and the test piece was immersed in hot water at 95 ° C. to determine the number of days until blistering occurred. Table 1 shows the above results. In Table 1, the number of days until the occurrence of blisters is shown as durability.

[0042]

Table 1 Example 1 Comparative Example 1 Comparative Example 2 Example 2 Comparative Example 3 Comparative Example 4 付 着 Adhesive Strength 2.4 2.8 1.8 1.8 2.0 1.2 Durability 26 18 20 24 19 21 ━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━ Note) Unit of adhesion strength: average value of 5 MPa Unit of durability: day

From the results shown in Table 1, it can be seen from the results that the polyurethane layer containing glass flakes formed between the first glass flake layer and the second glass flake layer shows the adhesion strength and the number of days until blistering. Both are excellent, whereas those in which a polyurethane layer that does not contain glass flakes is formed between the first glass flake lining layer and the second glass flake lining layer, the adhesion strength is good However, it can be seen that the number of days until blistering was inferior.

[0044]

According to the present invention, there is provided a lining structure in which a second glass flare lining layer is formed on a first glass flare lining layer, such as for repairing when the first glass flare lining layer is deteriorated. In addition, a lining structure having good adhesion between the first and second glass flaking lining layers and suppressing the occurrence of blisters can be obtained.

Claims (1)

[Claims] 1. A lining structure in which a second glass flare lining layer is formed on a first glass flare lining layer formed on a surface of a metal base via a polyurethane layer containing glass flakes.