JPS6126940B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a heat-resistant anticorrosive compound, more specifically, a tape for use on the surface of pipes, valves, fittings, tanks, and other metal structures, especially steel structures, in various industries such as gas, oil, water, chemical, shipbuilding, and construction. The present invention relates to a heat-resistant anti-corrosion compound that is applied in the form of mastics, paste, primer, etc., and forms an anti-corrosion layer that cuts off contact between the structure and water, air, etc. to prevent corrosion. Conventionally, as one of the corrosion prevention measures for metal structures in various industries, for example, mineral oil, animal and vegetable oil, wax, asphalt, etc. are used as the main ingredients (base).
Compounds containing corrosion inhibitors, fillers, etc., are commonly used in the form of tapes in which tape base materials are impregnated with the compounds, or in other forms such as mastics and pastes. In particular, this compound has a strong adhesion to the metal surface as its main component (base) and does not evaporate or harden over a long period of time.
It is highly praised for its ability to semi-permanently form an anti-corrosion layer that maintains viscosity on metal surfaces. However, the upper limit of the environmental temperature in which the above compound can be used is approximately 55 to 60°C, and at temperatures exceeding this temperature, its adhesion to the metal surface decreases, the compound flows out and flows down, and the desired anticorrosion effect cannot be achieved. It has the disadvantage that it is not. This drawback is especially true when the above compounds are used in ground-mounted gas and oil tanks.
This is extremely important when installing on the outer periphery of, for example, around the hem or on pipes. In fact, the surface temperature of structures such as tanks can easily exceed the upper limit of the above operating temperature (usually 70℃) due to normal sunlight irradiation.
Under such high temperatures, the compound will peel off from the metal surface or the compound itself will flow down, failing to achieve the desired anticorrosion effect and causing disasters such as explosions and oil spills. Although various attempts have been made to improve the shortcomings of poor high temperature resistance (heat resistance) found in the above-mentioned known anti-corrosion compounds, the flexibility of the base component,
No compound has been developed that can improve heat resistance without substantially impeding low-temperature properties, weather resistance, etc. The present inventors have expanded the usable environmental temperature range in view of the above-mentioned current situation, and have achieved sufficient corrosion prevention effect without leaking or flowing down even at high temperatures of around 120 ° C.
Moreover, we are working diligently to provide a new heat-resistant anti-corrosion compound that does not harden or become brittle even at low temperatures of around -35°C, and of course has all the other properties required of known anti-corrosion compounds of this type. I did a lot of research. As a result, the following specific (A)
It has been found that a compound using a combination of predetermined amounts of each of the components (C) satisfies the above objective. The present invention was completed based on this knowledge. That is, the present invention is a heat-resistant anticorrosion compound that is applied to the surface of a metal structure in a form selected from tape, mastic, paste, and primer, and which (A) is obtained from high-boiling petroleum distillate or kettle residual oil and is heated at room temperature. 50 to 95 parts by weight of a hydrocarbon mixture (hereinafter referred to as component A), which exhibits a solid or jelly-like state and has a melting point of 50°C or higher and a consistency of 60 to 360 (at 25°C); (B) a natural or synthetic resin; and (or) 3 to 20 parts by weight of natural or synthetic rubber (hereinafter referred to as component B), and (C) amide (hereinafter referred to as component C) 2 to 20 parts by weight.
It pertains to a heat-resistant anticorrosive compound characterized in that it contains 30 parts by weight. The heat-resistant anticorrosive compound of the present invention has all the properties required of this type of compound. That is, the compound (1) has a high melting point with almost no evaporation loss, (2) is highly flexible and has excellent low temperature resistance, (3) has excellent adhesion and stickiness to metal surfaces, and (4) ) Does not cause run-off or decrease in adhesion at high temperatures,
(5) Low viscosity, good workability, and no uneven impregnation during melt impregnation into the tape base material, (6) Weather resistance, acid resistance, alkali resistance, water resistance, and salt water resistance, and excellent rust prevention ability.
(7) It has plasticity and can be applied to metal surfaces with complex shapes, (8) it can retain its internal viscosity semi-permanently after application, and there is no risk of hardening or cracking, (9) it naturally pollutes the working environment. It does not cause any toxicity or cause skin irritation (chapped hands, etc.) to those who handle it, and does not cause any pollution problems. In particular, the heat-resistant anti-corrosion compound of the present invention can be used under an unprecedentedly wide range of temperature conditions, from low to high temperatures, and virtually no adverse effects are observed under this wide range of temperature conditions. Features can be added. In fact, the compound of the present invention is based on blending predetermined amounts of each of the above-mentioned specific A to C components, as shown in the Examples described below.
Has a heat-resistant flow point of 70℃ or higher, around 120℃, and -35℃
It has passed the cold bending test and has particularly excellent adhesion, water resistance, and salt water resistance. Therefore, the compound of the present invention can be used as anticorrosive tapes, sheets, etc., as well as other anticorrosive mastics, pastes, primers, etc., for corrosion protection of various metal structures exposed to low temperature and high temperature environments, and also for use in harsh environments such as underground and underwater. It is extremely useful for preventing corrosion of metals under harsh conditions. The hydrocarbon mixture used as component A in the compound of the present invention is obtained from high-boiling petroleum fractions or kettle residue, and is solid to jelly-like at room temperature.
It is selected from those having a melting point above 50°C and a consistency (at 25°C) of 60 to 360°C. Specific examples include slug wax, petrolatum and similar petroleum products. The above component A has the original properties as a hydrocarbon mixture, that is, it is strong, and has water resistance, acid resistance, alkali resistance, etc., so when it is used as a base, the resulting compound will not harden, crack, etc., and will be porous. It can provide the property of forming a semi-permanent anti-corrosion layer that can completely prevent the permeation of moisture and air. Further, in the compound of the present invention, it is essential to use a natural or synthetic resin and/or a natural or synthetic rubber as component B. Such B
The component mainly contributes to improving the adhesiveness and adhesion of the compound and improving the flexibility without substantially inhibiting the properties of the above-mentioned component A. As the natural or synthetic resin constituting component B, natural rosin, tenpene resin, rosin-modified resin, and aliphatic, aromatic, and alicyclic petroleum resins can be preferably used. Typical examples include natural rosin (Chukyo Rosin), YS Resin _P
1150'' (manufactured by Yasushi Oil Co., Ltd.), ``Ester Gum H'' (manufactured by Arakawa Chemical Industry Co., Ltd.), ``Malquid No. 2'' (manufactured by the same company), ``Escorets 1102B or 1103U'' (manufactured by Etsuso Chemical Co., Ltd.), ``Quinton D'' -100 or U-185” (manufactured by Zeon Corporation), “Petrozine 120” (manufactured by Mitsui Petrochemicals Co., Ltd.), “High Range #90” (manufactured by Toho Petroleum Resin Co., Ltd.),
“Neopolymer 120” (manufactured by Nisseki Chemical Co., Ltd.), “Escolets 5300 or 5320” (manufactured by Etsuo Chemical Co., Ltd.), “Alcon P-125” (manufactured by Arakawa Chemical Co., Ltd.), “Polybutene
HV-1900'' (manufactured by Nisseki Kagaku Co., Ltd.). As the natural or synthetic rubber, natural rubber, thermoplastic rubber, polyisobutylene, polybutene, etc. can be preferably used.
LMMH or LMMS" (manufactured by Etsuo Kagaku Co., Ltd.), "Polybutene SV-7000" (manufactured by Nisseki Kagaku Co., Ltd.), and the like. The above-mentioned component B can be used alone or in combination of two or more kinds, but the combination of a natural or synthetic resin and a natural or synthetic rubber is most preferable. Furthermore, the amide used as component C in the present invention is a relatively high-melting-point amide obtained from a carboxylic acid having 8 to 40 carbon atoms and a mono-, di-, or tri-amine having an alkyl group having 1 to 40 carbon atoms. Amides are preferred, and the carboxylic acid may be aliphatic or aromatic. In particular, commercially available high melting point amide or polyamide (mono-, di- or tri-amide) are preferred. When added to the compound of the present invention, this component C has the effect of significantly increasing the softening point of the compound, imparting high heat resistance, and greatly increasing the upper limit of the environmental temperature in which it can be used. Specific examples include "Hoechst Wax C" (manufactured by Hoechst Japan Co., Ltd.), "Bisamide" (manufactured by Nippon Kasei Co., Ltd.), "KAO Wax EB" (manufactured by Kao Soap Co., Ltd.), and "Aramide 18" (manufactured by Lion Armor Co., Ltd.). , "Aamide P" (manufactured by Nitto Kagaku Co., Ltd.), and the like. It is important that the compound of the present invention contains a predetermined amount of each of the above-mentioned components A to C, and the blending amount of component A is 50 to 95 parts by weight, preferably 60 to 95 parts by weight.
80 parts by weight, 3 to 20 parts by weight of component B, preferably 5 to 20 parts by weight
15 parts by weight and 2 to 30 parts by weight of component C, preferably 5 parts by weight.
~15 parts by weight, thereby achieving the intended purpose of the present invention. In particular, in the compound of the present invention, it is important to use component A, component B, and component C in combination. It is possible to achieve remarkable effects that cannot be achieved by other methods, and moreover, it is possible to successfully prevent the occurrence of various adverse effects that cannot be avoided when each of these is used alone. On the other hand, if either one of the B component and C component is missing, or if they are used together but outside the above range, the invention may not have the excellent properties that are the object of the present invention, but may have adverse effects. It is not possible to obtain an anti-corrosion compound without it. These matters are clear from the Examples and Comparative Examples described later. For example, if the C component is missing or is used in an amount below the above range, no improvement in heat resistance can be expected, as with conventionally known compounds of this type, resulting in a product that cannot be used under high-temperature conditions. It's nothing more than that. In addition, if the above component C is used in an amount greater than 30 parts by weight, the product cost will be high and it is not practical; if the component B is absent or is used in an amount below the above range, adhesion may decrease, bleed, cracks, etc. may occur. , reduced low temperature resistance,
A decrease in water resistance is observed, making it difficult to achieve the desired anticorrosion effect. In other words, in a compound consisting of component A and component C, the inherent anti-sticking (prevention of blocking) and mold release effects of component C appear as harmful effects, and furthermore, when component C is blended alone with component A, it causes crystallization. It has a high tendency to breed,
The resulting compound becomes hard and brittle at low temperatures.
In addition, if the above component B is used in a large amount exceeding 20 parts by weight, the heat resistance properties will decrease and the melt viscosity will increase, resulting in poor workability of the compound, and if the compound is used as an anticorrosion tape. This is not preferable since the tape base material may be impregnated insufficiently or may be impregnated unevenly. Furthermore, as mentioned above, the amount of component A must be at least 50 parts by weight. If this amount is less than 50 parts by weight, the compound will become too hard, the weather resistance will decrease, and the internal viscosity of the compound will be lost. Earnings will be difficult. The compound of the present invention basically consists of the above-mentioned components A to C, but if necessary, corrosion inhibitors and inorganic fillers that are commonly added may be added thereto. Examples of corrosion inhibitors include commonly used oil-soluble corrosion inhibitors such as carboxylic acid, ester, metal soaps, sulfonates, lanolin and its derivatives, and oxidized paraffins. Further, as the inorganic filler, any of various usual inorganic fillers such as silica, talc, clay, calcium carbonate, diatomaceous earth, alumina, bentonite, chlorite, and magnesium carbonate can be used. The heat-resistant anti-corrosion compound of the present invention can be used as a mastic or primer by heating and mixing a predetermined amount of the above-mentioned components A to C and an appropriate amount of a corrosion inhibitor and/or an inorganic filler as necessary, and solidifying by cooling. The molten mixture obtained by heating and mixing the above components is impregnated into a suitable base material such as woven fabric, synthetic fiber non-woven fabric, metal fiber non-woven fabric, felt, asbestos, pulp, paper, etc. It is used in tape form. The manufacturing and application methods of the mastic, paste, primer, tape, etc. described above are not substantially different from those conventionally known. In particular, the compound of the present invention has an advantage in that operations such as tape production are extremely simple since it has an appropriate viscosity when melted. Thus, the anticorrosive compound of the present invention, in the form of tape, mastic, paste, primer, etc., greatly contributes to anticorrosion measures in various industries. In particular, this compound can be used to prevent corrosion of pipes buried underground or at low sea level, to treat various pipe joints, to prevent corrosion around the bases of gas and oil tanks, and to protect networks in corrosive atmospheres, such as atmospheres containing sulfur dioxide, salt, etc. It is extremely effective for corrosion protection of manufactured structures, coating and waterproofing of marine steel structures, etc. Examples and comparative examples are given below to explain the present invention in more detail. Examples 1 to 4 Predetermined amounts of each substance listed in Table 1 were used as components A to C, and these were mixed and melted at 150 to 160°C and then cooled to obtain a heat-resistant anticorrosion compound of the present invention. Its composition is shown in Table 1.

【table】

[Table] Each component in Table 1 indicates the following. A-1... Slut wax (thickness 120 at 25°C, melting point 73°C) A-2... Petrolatum (thickness at 25°C
95, with a melting point of 77°C) B-1... "Escolets 1102-B" (manufactured by Etsuso Chemical Co., Ltd.) B-2... "Polybdenum HV-1900" (manufactured by Nisseki Chemical Co., Ltd.) B-3... "Vistanetx"LMMS" (manufactured by Etsuo Kagaku Co., Ltd.) C-1..."Hoechst Wax C" (manufactured by Hoechst Japan Co., Ltd.) C-2..."Aramide 18" (manufactured by Lion Armor Co., Ltd.) Comparative Examples 1 to 5 Same as the above examples A comparative compound having the composition shown in Table 2 below was obtained.

[Table] The symbols for each component in Table 2 are the same as those in Table 1, and A-3 indicates the following. A-3...Petrolatum (temperature at 25℃
280, melting point 68° C.) The following tests were conducted on each compound obtained in each of the above Examples and Comparative Examples. 1 Heat resistant flow point Performed according to JIS-K-2246. However, the average coating thickness is 1300±100μm using a 1.3mm mold.
shall be. Measure the temperature when the coating film flows down to the reference line to determine the heat-resistant flow point. 2 Cold resistance bending test A coating film of each compound with a thickness of 1 mm was formed on an aluminum plate (30 mm x 100 mm), and after cooling it to a specified temperature, it was bent 180 degrees along an andrel with a diameter of 80 mm. Observe the compound coating for peeling or cracking from the aluminum plate. . Temperature conditions: -25℃, -30℃ and -35℃
℃, and those with no abnormality at each temperature are considered acceptable, and those with peeling or cracking are rejected. 3. Adhesive shear test (adhesion test) A 50 mm wide nonwoven fabric was impregnated with each compound and used as a sample tape. Next, one end of the sample tape is attached to the upper half of a steel pipe with an outer diameter of 50 mm that is fixed horizontally in a room temperature room, and a 1 kg weight is hung from the other end, and the tape falls (slips).
Measure the time (seconds). 4 Salt spray test A test piece coated with each compound was prepared according to JIS-K-2246, and this was tested in accordance with JIS-K-2246.
Subject to salt spray test in accordance with 2371. The result is JIS
- Measure and evaluate according to K-2246. 5. Moisture test A test piece coated with each compound is subjected to a wetness test in accordance with JIS-K-2246. The results of each of the above tests are shown in Table 3 below.

[Table] The following is clear from Table 3 above. That is, according to the present invention, based on the combination of predetermined amounts of each of the above-mentioned components A to C, the
Shows a heat-resistant flow point of up to 130℃, and -35℃
The compound is fully usable for practical use, and also has excellent properties in terms of adhesion, salt water resistance, water resistance, etc., and is extremely useful as a heat-resistant anticorrosive tape, mastics, etc. On the other hand, with component A alone (Comparative Examples No. 1 and 2) and with component A and component B in combination (comparative example 3), it was impossible to improve the desired heat resistance, and other properties were still improved. It is an insufficient thing that should be done. In addition, when the A component and the C component are used in combination (Comparative Examples 4 and 5), an improvement in heat resistance is observed in Comparative Example 4, but this fails the cold resistance bending test at -35°C, and has low adhesion and water resistance. ,
Salt water resistance is also poor, and Comparative Example 5 no longer has substantial adhesion, making it unusable. Examples 5 to 9 and Comparative Examples 6 to 13 In place of the A-1 component used as the base component in Example 1, predetermined amounts of each of the following components were used, and B-1 component and C-1 component, respectively, were used. Predetermined amounts of each were blended to obtain each sample compound having the composition shown in Table 4 in the same manner. <Base component> A-3 (present invention)... Petrolatum (stiffness 76 at 25°C, melting point 74°C) A-4 (present invention)... Petrolatum (stiffness 228 at 25°C, melting point 66) °C) a-1 (comparison)...Multi wax W-445 (microcrystalline wax manufactured by Witco Chemical Co., Ltd., with a hardness of 9 at 25 °C, a penetration of 19, and a melting point of 79 °C) a-2 ( Comparison)...Paraffin Wax 135〓
(Tightness 2, Penetration 10, Melting point 60 at 25℃
℃) Tests were conducted in the same manner as above for each sample compound obtained in each of the above Examples and Comparative Examples.
The results are also listed in Table 4. However, each test was conducted as follows. Temperature...according to JISK2235. Penetration...according to JISK2235. Melting point...according to JISK2235. Heat resistance flow point: Same as Table 3 above. Cold resistance bending test...according to the following method. A coating film of each sample compound with a thickness of 1 mm was formed on an aluminum plate (30 mm x 100 mm), and this was bent 180° along a mandrel with a diameter of 80 mm at a predetermined temperature. Observe for peeling or cracking.
If there is no abnormality under the specified temperature tested, it is considered to be passed, and if peeling or cracking occurs, it is judged to be rejected. Adhesive slippage test...Same as in Table 3. Salt spray test...Same as in Table 3. Wet test...Same as in Table 3.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A heat-resistant anticorrosion compound applied to the surface of metal structures in a form selected from tape, mastic, paste, and primer, which compound (A) is obtained from high-boiling petroleum distillate or kettle residue; , 50 to 95 parts by weight of a hydrocarbon mixture that is solid or jelly-like at room temperature, has a melting point of 50°C or more and a hardness (at 25°C) of 60 to 360; (B) a natural or synthetic resin and (or ) A heat-resistant anticorrosion compound characterized by containing 3 to 20 parts by weight of natural or synthetic rubber, and (C) 2 to 30 parts by weight of an amide.