JPH0360330B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an underwater curable epoxy resin composition that can be effectively used as an anticorrosive material, adhesive, etc. underwater and has excellent workability in underwater construction. Epoxy-based underwater curing paints and sealers have traditionally been used for offshore repairs of marine structures and ships, and for corrosion protection of corroded steel parts in flooded areas of port facilities. These materials have low adhesion in water to the steel material to be coated, and therefore have unsatisfactory corrosion resistance. Furthermore, in terms of underwater application workability, the water on the surface of the object to be coated has poor displaceability with the paint, making it difficult to spread the paint over the surface of the object to be coated. However, these have the problem that when the paint is stirred in water during underwater application using a brush, etc., the paint becomes suspended and thickens significantly, making the application process even more difficult. This invention was developed as a result of studies aimed at solving the above-mentioned drawbacks and providing an underwater curable epoxy resin composition that has excellent coating workability in water and excellent adhesion to objects to be coated. It has been done. That is, this invention provides (a) an average of approximately
A non-alicyclic epoxy resin having 1.7 or more epoxy groups, (b) mainly containing at least one polyamine selected from isophorone diamine, cyclohexane diamine, diaminodiphenylmethane, metaphenylene diamine, and derivatives thereof Contains a curing agent and (c) an inorganic filler with a specific gravity of 3.0 or more as essential components, has a specific gravity of 1.2 or more, and has a specific gravity of 20
The present invention relates to an underwater curable epoxy resin composition for underwater construction, which has a viscosity of 10 to 3000 poise at a temperature of 10 to 3000 poise at a temperature of 10 to 3000 poise. The viscosity referred to in this specification is measured using a Bruckfield HB rotational viscometer with a No. 5 rotor at 10 rpm. The epoxy resin composition for underwater construction of this invention is
By using the above-mentioned non-alicyclic epoxy resin as the epoxy resin and using the above-mentioned specific polyamine as the curing agent, the affinity with water is adjusted appropriately, so it is difficult to coat the coating surface during underwater coating work. It is easy to spread the paint over the surface of objects, and even when the paint is stirred in water, it does not become suspended and thicken, giving it excellent application workability.Furthermore, the cured product obtained from this composition can be used to coat materials such as steel plates. It has excellent adhesive properties to objects, is durable not only to seawater, but also to acidic aqueous solutions, and has excellent chemical resistance. The workability of coating in water is also affected by the specific gravity and viscosity of the epoxy resin composition, and if the specific gravity of the composition is lower than the specific gravity of water, the composition tends to float during application, reducing the workability of application. At the same time, the composition may float on the water surface and contaminate ports, etc.If the viscosity of the composition is too high, the coating workability will be reduced. The viscosity at the initial stage of mixing at 20°C, that is, the viscosity at the time of application, is set at 10 to 3000.
Poise is set to prevent the above-mentioned deterioration in coating workability and contamination caused by this. In addition, since the epoxy resin composition of the present invention has a viscosity range set as described above, the adhesion of the composition to the coated object before curing is also good, and as a result, the cured product has good adhesion. Good results have also been achieved in terms of adhesion to coated objects. In other words, the surface tension of water is approximately 73 dyne/ ^cm2 , whereas that of an epoxy resin composition is usually
50dyne/ ^cm2 or less, more commonly 30-45dyne/
in the ^cm2 range. Therefore, a composition applied in water is subjected to a force that causes it to form a spherical shape due to the surface tension of the water. If the viscosity of the composition is too low, i.e. less than 10 poise, the force of the water will cause the composition applied to the object to change into a spherical shape, causing the composition to peel off from the object. , the adhesion area decreases, the adhesion after curing decreases, and a sufficient anticorrosion effect cannot be obtained. On the other hand, when the viscosity of the composition is 10 poise or more as described above, the applied composition does not deform even when subjected to the surface tension of water and adheres well to the object to be coated. There is. In addition, if the object to be coated is stained with oil, some oil will remain even if it is removed by scouring, etc., and the epoxy resin composition should not be applied to the object to be coated with some oil. When applying this composition in oily or oily water, the composition usually has difficulty adhering to the object to be coated, but the epoxy resin composition of the present invention can be applied successfully even in such cases. can do. As mentioned above, the epoxy resin composition for underwater application of the present invention has excellent coating workability in water and is non-contaminating, and the cured product has excellent adhesion to the object to be coated and is chemically resistant. Because it has the characteristics of excellent hardness and acid resistance, it is useful as an anticorrosive material and adhesive in seawater and water containing chemicals. The non-alicyclic epoxy resin used in this invention, that is, component a, has an average of about 1.7 or more epoxy groups per molecule, preferably an average of about 1.7 to 3.0, and more preferably an average of about 1.7 to 2.3. If the number of epoxy groups is less than the above, a cured product with excellent mechanical strength etc. cannot be obtained, and alicyclic epoxy resins are unsuitable due to poor room temperature curability. Note that the term non-alicyclic epoxy resin herein refers to a resin that has an epoxy group only in a portion other than the alicyclic structure, regardless of the presence or absence of an alicyclic structure, and the term alicyclic epoxy resin refers to a resin that has epoxy groups only in parts other than the alicyclic structure. It means a resin having at least one alicyclic structure to which a group is bonded. Examples of the above-mentioned non-alicyclic epoxy resins as component a include the following. That is, epoxidized cyclic silanes, epoxidized soybean oil, polyglycidyl esters of polycarboxylic acids, epoxidized polyolefins, and glycidyl ether resins.
Among these, glycidyl ether resin is preferred. Examples of the polycarboxylic acid polyglycidyl ester include diglycidyl ester of linoleic dimer acid and triglycidyl ester of linoleic trimer acid. Suitable glycidyl ether resins include polyallyl glycidyl ether, diglycidyl ether of chlorendiol, diglycidyl ether of dioxanediol, diglycidyl ether of endomethylenecyclohexanediol, epoxy novolac resins, alkanediol diglycidyl ether, alkane triols. These include triglycidyl ether. More desirable glycidyl ether resins include alkanediol diglycidyl ethers represented by the following formula. (In the formula, X is an alkylene or alkylidene group having 1 to 10 carbon atoms, preferably 2 to 6 carbon atoms, and n is 1 to 20, preferably 1 to 15.) Suitable alkanediol diglycidyl ethers are , ethylene glycol diglycidyl ether,
These include propylene glycol diglycidyl ether and butanediol diglycidyl ether. Other more desirable glycidyl ether resins include alkanetriol triglycidyl ethers with alkanetriyl groups having from 2 to 10 carbon atoms, especially from 3 to 10 carbon atoms, such as glyceryl triglycidyl ether, triglycidyl ether of trimethylolpropane, etc. . Still other more desirable glycidyl ether resins are di- and polyglycidyl ethers of bisphenols represented by the formula: (In the formula, R is a divalent radical containing 1 to 8 atoms of at least one selected from the group consisting of C, O, S, and N, preferably an alkylene or alkylidene group having 1 to 8 carbon atoms, more preferably is an alkylene or alkylidene group having 1 to 6 carbon atoms.) Among the above, suitable bisphenols include methylene bisphenol, isopropylidene bisphenol, butylidene bisphenol, octylidene bisphenol, and bisphenol sulfide. , bisphenol sulfone, bisphenol ether, and bisphenolamine. In particular, excellent results were obtained using methylene bisphenol. Suitable di- and polyglycidyl ethers include di- and polyglycidyl ethers of methylene bisphenol. The curing agent used as component b used in this invention usually contains 60 to 100% by weight of at least one polyamine selected from isophorone diamine, cyclohexane diamine, diaminodiphenylmethane, metaphenylene diamine, and derivatives thereof.
It includes. The above-mentioned derivatives are compounds having an epoxy group in each of the above-mentioned diamines, or modified polyamines obtained by reacting phenols with a compound having a carbonyl group. As a compound having the above epoxy group, for example, the following formula; (In the formula, R is a hydrogen atom, a methyl group, or an ethyl group.) Examples include epoxy resins having an average of more than one group in one molecule. In addition, examples of the above-mentioned phenols include phenol, cresol, alkyl-substituted phenol, halogen-substituted phenol, anisole, 2-
Examples include 2-bis(4-hydroxysphenyl)propane. Further, examples of the above-mentioned compounds having a carbonyl group include formaldehyde, paraformaldehyde, crotonaldehyde, acetaldehyde, glyoxal, acetone, and furfurylaldehyde. In addition to the above-mentioned polyamine as the main component, component b may contain other curing agents in a proportion of less than 40% by weight. Examples of such curing agents include polyamidoamine, ethylenediamine, diethylenetriamine, triethylenetetramine, dimethylaminopropylamine, diethylaminopropylamine, etc., which are condensation reaction products of polymerized fatty acids such as dimer acid and trimer acid with various polyamines. and modified polyamines obtained by modifying the above-mentioned polyamide amines and aliphatic polyamines using a compound containing an epoxy group or a phenol and a carbonyl compound. The blending ratio of the above component b in the epoxy resin composition of the present invention is such that the active amine hydrogen equivalent in the component b is usually 0.5 to 2.0 equivalents, preferably 0.5 to 2.0 equivalents, relative to the epoxy group of the non-alicyclic epoxy resin that is the component a. teeth
The ratio is preferably 0.5 to 1.5 equivalents. If the blending ratio of component b is too small, curing will be delayed, and if it is too large, the physical properties of the cured product will deteriorate, which is not preferable. The inorganic filler used as component c in this invention has a specific gravity of 3.0 or more, preferably 3.1 or more and usually up to 17.2. Examples of such inorganic fillers include inorganic oxides such as titanium dioxide, magnesium oxide, zirconium oxide, and aluminum oxide, inorganic sulfates such as barium sulfate, and inorganic carbides such as barium carbide, manganese carbide, molybdenum carbide, and silicon carbide. Suitable examples include inorganic nitrides such as , calcium nitride, magnesium nitride, and silicon nitride. If the specific gravity of the inorganic filler is less than 3.0, it is not preferable because the specific gravity of the epoxy resin composition cannot be increased to 1.2 or more within a range where the amount of the inorganic filler does not deteriorate the physical properties of the cured product. The blending ratio of the inorganic filler, that is, component c, in the epoxy resin composition of the present invention is such that component c is usually 15 to 60% by weight of the total amount of component a, component b, and component c. It is better to do so. If this c component is too small, the specific gravity of the composition cannot be made to be 1.2 or more without deteriorating the physical properties of the cured product, and if it is too large, the viscosity of the composition will increase and the coating workability will decrease, which is undesirable. . The epoxy resin composition for underwater construction of this invention is
Although the above components a, b, and c are included as essential components, various optional components may be included in addition to these components. Examples of this include various known diluents (including reactive diluents) for adjusting viscosity, various known curing aids or curing accelerators for adjusting curing speed, and various known diluents with a specific gravity of less than 3.0. Inorganic fillers such as silica, clay, coal powder, calcium carbonate, asbestos, etc.
Further examples include various known fluidity regulators, silane coupling agents for improving water resistance, antifoaming agents, anti-cissing/pinhole agents, antioxidants, stabilizers, and the like. The epoxy resin composition for underwater construction of the present invention obtained by mixing the above components has a specific gravity of 1.2.
above, preferably adjusted to 1.4 to 2.6, and
It is important that the viscosity at 20° C. at the initial stage of mixing is adjusted to 10 to 3000 poise, more preferably 30 to 2500 poise. If the specific gravity of the composition is less than 1.2, it is not preferable because coating workability is reduced and staining occurs. Further, if the above-mentioned viscosity is less than 10 poise, the adhesion of the composition to the object to be coated decreases, and if it exceeds 3000 poise, the coating workability decreases, which is not preferable. In addition, since the epoxy resin composition of the present invention is room temperature curable, it is usually a two-component type consisting of an epoxy resin blend system containing component a as the main component and a curing agent blend system containing component b as the main component. Component c and other optional components are preferably included in either one or both of the blending systems, and these blending systems are mixed at the time of use. When using the epoxy resin composition of the present invention for underwater construction, after mixing as described above, apply an appropriate brush or rubber spatula to the surface of a workpiece such as a steel plate in water or in a humid atmosphere as the case may be. It may be applied by any means, and then left to stand to naturally harden to form a coating film with good adhesion to the object to be coated. Examples of this invention will be described below. Examples 1 to 9 and Comparative Examples 1 to 4 Non-alicyclic epoxy resin (Epicoat #807 manufactured by Yuka Ciel Co., Ltd.; bisphenol F type epoxy resin,
Average number of epoxy groups per molecule: 1.9, epoxy equivalent: 170), reactive diluent (phenyl glycidyl ether), titanium white (R-650 manufactured by Sakai Chemical Co., Ltd.; specific gravity
4.1), Magnesia (Tateho Chemical Industry Co., Ltd. product number
300; specific gravity 3.6), silica (specific surface area 300-400m ² /
gr, specific gravity 2.2), curing agent A (at least one selected from the following polyamines *A to *D) and curing agent B (Sanwa Kagaku Co., Ltd. Sanmide #315; polyamide amine, amine value 310, active amine Hydrogen equivalent
120 (average number of amino groups per molecule: 5.5) is uniformly mixed with a stirrer at the proportions shown in the table below, and the specific gravity and viscosity at the initial stage of mixing at 20℃ are the values shown in the table below.For underwater construction. An epoxy resin composition was obtained. Note that the polyamines in *A to E above represent the following. *A; Polyamine containing isophorone diamine and its derivatives (Ancamine MCA manufactured by ACI Japan, amine value 305, active amine hydrogen equivalent)
102) *A; Polyamine containing diaminodiphenylmethane and its derivatives (ACI Japan Co., Ltd. Ancamine LO, amine value 280, active amine hydrogen equivalent 99) 1618, amine value 275, active amine hydrogen equivalent 115)
The viscosity at °C is a value measured using a Bruckfield HB rotational viscometer with a No. 5 rotor and 10 rpm. Furthermore, the coating workability, staining resistance, and adhesive strength of the obtained epoxy resin composition for underwater construction were examined as follows, and the results are also listed in the table below. <Coating workability> The epoxy resin composition was applied to a thickness of about 1 mm using a brush or a rubber spatula on a 300 mm x 300 mm x 9 mm steel plate immersed in water, and the difficulty of coating workability in water was determined. <Staining property> A sample in which no floating matter was generated during the above coating operation was considered to be non-staining, and a sample in which floating matter was generated was considered to be polluting. <Adhesive strength> The steel plate coated with the epoxy resin composition as described above was left in water at 20°C for two weeks, then pulled out and the tensile adhesive strength of the coating film was measured using an Elcometer (manufactured by Elcometer Instrument Co., Ltd.). It was measured.

【table】

[Table] *1 Magnesia was used in Example 3, titanium white was used in the others *2 Many floating objects with a diameter of 5 to 20 mm were generated.
As is clear from the above results, the epoxy resin composition for underwater construction of the present invention can be used as a corrosion protection agent and adhesive for objects immersed in water. Moreover, it has excellent adhesion to the coated object.

Claims (1)

[Claims] 1. At least one selected from (a) a non-alicyclic epoxy resin having an average of about 1.7 or more epoxy groups per molecule, (b) isophorone diamine, cyclohexane diamine, diaminodiphenylmethane, metaphenylene diamine, and derivatives thereof. A curing agent mainly composed of one type of polyamine and (c) a specific gravity of
Contains an inorganic filler of 3.0 or higher as an essential ingredient,
An underwater curable epoxy resin composition for underwater construction, which has a specific gravity of 1.2 or more and a viscosity of 10 to 3000 poise at 20° C. at the initial stage of mixing.