JP3172318B2 - Water repellent anticorrosion layer and anticorrosion treated material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-repellent anticorrosive layer which can be easily applied at room temperature with good adhesion and is suitable for metal corrosion prevention treatment, and a material for the anticorrosion treatment.

[0002]

2. Description of the Related Art Heretofore, there has been known an anticorrosion layer formed by lining hot-melt polyethylene or epoxy resin on a metal surface by a heating coating method using a production line. However, lining requires a complicated processing operation and a large amount of heat, and the anticorrosion layer formed during storage and transportation is easily damaged by external factors, and lining to the connection part of anticorrosion parts, for example, the connection part of the pipeline There was a problem that processing was difficult.

On the other hand, as a corrosion protection layer which can be formed by a cooling method which does not require a large amount of heat and which is advantageous for on-site construction, a polymerized cured film formed by applying a urethane resin or an epoxy resin to a metal surface has been known. However, it is difficult to form a uniform anticorrosion layer because the coating thickness tends to fluctuate, and in the case of a two-pack type coating liquid, the physical properties of the film are uneven due to the variation in the mixing ratio, making it difficult to form a uniform anticorrosion layer. was there.

On the other hand, as an anticorrosion layer having good thickness and homogeneity, there has been known an anticorrosion tape in which a pressure-sensitive adhesive layer provided on an anticorrosion substrate such as a film is wound or adhered to a metal surface. However, there has been a problem that the anticorrosion tape is easily deformed due to an external temperature or an external pressure, wrinkles and floating are easily generated in the anticorrosion layer, and there is a problem that dirt, dust and the like are easily attached and contaminated.

[0005]

SUMMARY OF THE INVENTION The present invention can be easily carried out at a low temperature such as room temperature even at a work site without requiring complicated processing operations such as a lining process and a large amount of heat, and can also process a joint portion of an anticorrosion component. It is easy, and the formed anticorrosive layer has excellent uniformity of thickness and physical properties, and has a toughness that is not easily damaged or deformed by external factors, and it is hard to be wrinkled or lifted up. The task is to obtain an anticorrosion layer.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a room temperature cross-linkable coating material obtained by impregnating a porous base material with a liquid mixture containing an uncrosslinked liquid silicone rubber as a main component and one of a curing agent and a curing catalyst. Is applied to a metal surface or an anticorrosion defect to form a coating layer, and the coating layer contains an uncrosslinked liquid silicone rubber and / or silicone oil as a main component and the other of the above-mentioned curing agent or curing catalyst. A water-repellent anticorrosion layer characterized by being cross-linked with a cross-linking coating liquid, and a water-repellent anticorrosion treated material comprising the room-temperature cross-linkable coating material and a cross-linking coating liquid. .

[0007]

The room temperature cross-linking type coating material having the above-mentioned structure shows satisfactory wettability and deformability even when the coated surface such as a metal surface is rough or curved through the contained liquid admixture. In close contact. In addition, the separation of the curing agent and the curing catalyst enables stable long-term storage, and the application of the coating liquid for crosslinking allows the liquid to penetrate into the coating layer of the room-temperature crosslinking type coating material and uncrosslinked liquid in the liquid mixture. The silicone rubber and the curing agent react under the action of a curing catalyst to crosslink at room temperature or the like, and form a tough water-repellent anticorrosion layer together with the porous substrate while firmly adhering to a metal or the like.

As a result, an anticorrosive layer having excellent uniformity in thickness and physical properties can be easily formed at a work site by low-temperature construction, and a connection portion such as a pipeline can be easily processed. In addition, since it is a curing mechanism using the crosslinking reaction of liquid silicone rubber, it is possible to avoid the involvement of harmful organic solvents etc. when forming the anticorrosion layer, and it cures to a tack-free state in a short time of about several hours, In addition to being less contaminated, the surface tension is small, and scales and the like are less likely to adhere, and a state of excellent glossy beauty is maintained. Further, the formed anticorrosion layer is less likely to be damaged or deformed by external factors, and is less likely to generate wrinkles and floating, thereby maintaining a water-repellent anticorrosion effect for a long time.

[0009]

The room temperature crosslinking type coating material used in the present invention is as follows.
A flexible porous substrate is impregnated with a liquid mixture containing an uncrosslinked liquid silicone rubber as a main component and one of a curing agent and a curing catalyst. Further, the coating liquid for crosslinking contains uncrosslinked liquid silicone rubber and / or silicone oil as a main component and contains the other of the above-mentioned curing agents or curing catalysts.

The liquid admixture contains an uncrosslinked liquid silicone rubber, ie, a liquid polyorganosiloxane as a main component, and contains a curing agent or a curing catalyst and is cured by a curing mechanism such as a condensation reaction type or an addition reaction type to form a rubbery mixture. It becomes a cured product.

The uncrosslinked liquid silicone rubber has a general formula: R _a SiO _{(4-a) / 2} (wherein R is a substituted or unsubstituted monovalent hydrocarbon or hydroxyl group, and a is 1 ~
It is an integer of 3. ), A homopolymer or a copolymer composed of the structural units represented by formula (1), or a mixture thereof.

In the above formula, the substituted or unsubstituted monovalent hydrocarbon group of the group R may be the same or different, for example, a methyl group, an ethyl group, a propyl group,
Alkyl groups such as butyl group, hexyl group and dodecyl group; alkenyl groups such as vinyl group and allyl group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group, β-phenylethyl group and β-phenylpropyl group. Group, 3,
And monovalent substituted hydrocarbon groups such as a 3,3-trifluoropropyl group and a chloromethyl group. These compounds can be used to easily synthesize an uncrosslinked liquid silicone rubber (liquid polyorganosiloxane), its curing mechanism, and the like. It can be appropriately selected according to the fluidity of the composition and the physical properties such as heat resistance of the cured product of the composition.

The molecular structure of the uncrosslinked liquid silicone rubber to be used is not particularly limited as long as it is liquid at room temperature, and it has a linear, branched, network or slightly three-dimensional network structure, or a mixture of these. It may be in any state, but the viscosity at 25 ° C. is 100 to 10
It is preferable to use the one of 000 cSt,
The one with 000 cSt is more preferred.

When the viscosity is less than 100 cSt, it is difficult to impart excellent mechanical properties to a cured product of the composition. When the viscosity exceeds 100,000 cSt, the composition has appropriate fluidity. Can not do.

The preparation of the liquid mixture can be carried out by mixing an uncrosslinked liquid silicone rubber with one of a curing agent and a curing catalyst. The curing agent reacts with the uncrosslinked liquid silicone rubber or the silicone oil which is the main component of the crosslinking coating liquid at a low temperature such as room temperature in the presence of a curing catalyst to react with the uncrosslinked liquid silicone rubber or the silicone oil of the crosslinking coating liquid. It crosslinks.

The uncrosslinked liquid silicone rubber, curing agent or curing catalyst can be used in an appropriate combination depending on the curing mechanism such as condensation reaction type or addition reaction type so as to cure at a low temperature such as room temperature. .

In the case of the condensation reaction type liquid mixture, (a) a polyorganosiloxane whose molecular chain ends are blocked with a silanol group or an alkoxy group is used as an uncrosslinked liquid silicone rubber, and (b) silicon is used as a curing agent. An organosilicon compound having at least three hydrolyzable groups bonded to an atom in one molecule or a curing catalyst is blended.

Among the substituted or unsubstituted monovalent hydrocarbon groups bonded to silicon atoms in the polyorganosiloxane (a), a methyl group, a vinyl group or a phenyl group is preferred from the viewpoint of ease of synthesis. Furthermore, when the hydrocarbon group bonded to the silicon atom is a methyl group, the synthesis of the raw material intermediate is easier than in the case of other hydrocarbon groups, and the degree of polymerization of the obtained polymer is high. The lowest viscosity compared to
It is most preferable because it has a favorable effect on the balance of physical properties of the elastic body which is a cured product.

Therefore, it is most preferable that substantially all of the group is a methyl group. However, when heat resistance is required for the cured product, a part of the hydrocarbon group bonded to the silicon atom is a phenyl group. Is preferred. As described above, even when a hydrocarbon group other than a methyl group is contained, it is preferable that 85% or more of the total number of hydrocarbon groups in the polymer is a methyl group.

As the organosilicon compound of the component (b),
Any compound having at least three hydrolyzable groups bonded to a silicon atom in one molecule may be used, for example, a silane compound or a partially hydrolyzed condensate thereof, a linear polyorganosiloxane, or a cyclic polyorganosiloxane. Organosiloxanes can be used.

Examples of the hydrolyzable group bonded to a silicon atom in the organosilicon compound include an alkoxy group, an acyloxy group, an N, N-dialkylamino group, an N-alkylamide group, an N, N-dialkylaminoxy group, and a ketoxime. And alkenoxy groups.

In the organosilicon compound, the silicon atom may be, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, an alkenyl group such as a vinyl group or an allyl group, or a phenyl group in addition to the above-mentioned hydrolyzable group. Or a substituted or unsubstituted monovalent hydrocarbon group such as an aryl group such as a haloalkyl group such as a 3,3,3-trifluoropropyl group or a chloromethyl group.

The component (b) is preferably blended so that the hydrolyzable group bonded to the silicon atom is at least equivalent to the silanol group or the alkoxy group in the component (a). If the amount of the component (b) is too small, the condensation reaction of the component (a) does not proceed sufficiently.

On the other hand, as a curing catalyst for accelerating the condensation reaction, metal salts of organic carboxylic acids, for example, carboxylic acids such as acetic acid, octanoic acid, lauric acid, stearic acid, oleic acid, naphthenic acid and benzoic acid; Tin, zinc, lead,
Examples thereof include salts with metals such as iron, antimony, barium, titanium, and manganese.

Other than the above, for example, organotin compounds such as dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dimethyltin oleate hydroxide, dibutyltin oleate, diphenyltin diacetate, dibutyltin oxide and dibutyltin dimethoxide; Organic titanates such as propyl titanate, tetrabutyl titanate, tetraoctyl titanate, diisopropoxy (acetylacetonato) titanium, diisopropyl bis (ethyl acetoacetato) titanium, 1,3-propylene dioxybis (acetyl acetonate) Organic metal compounds such as titanium chelate compounds such as titanium and 1,3-propylenedioxybis (ethylacetoacetato) titanium can also be mentioned.

In the case of such a condensation reaction type liquid mixture, the uncrosslinked liquid silicone rubber is exposed to moisture in the air or the like in the presence of a curing agent and a curing catalyst (sometimes unnecessary). It is hydrolyzed and undergoes a cross-linking reaction to be cured into a rubbery state.

On the other hand, in the case of an addition reaction type liquid mixture,
As an uncrosslinked liquid silicone rubber, (c) a polyorganosiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule is used, and (d) an organohydrogensilane or a polyorganohydrosiloxane is used as a curing agent. A curing catalyst for the reaction is blended. When it is desired to obtain a gelled product by curing, a polyorganosiloxane having one alkenyl group bonded to a silicon atom in one molecule can be used as the component (c).

The alkenyl group contained in the polyorganosiloxane of the component (c) includes, for example, a vinyl group,
Examples thereof include an allyl group, a 1-butenyl group, and a 1-hexenyl group, and a vinyl group is preferable because of ease of synthesis.

The substituted or unsubstituted monovalent hydrocarbon group which can be bonded other than the alkenyl group is as described above, but the ease of synthesis, the fluidity of the composition and the cured product obtained from the composition are Most preferably, it is a methyl group because polymerization is possible to the extent that good physical properties can be maintained.

The organic group capable of bonding to a silicon atom in the organohydrogensilane or polyorganohydrogensiloxane of the component (d) is the same as the above-mentioned substituted or unsubstituted monovalent hydrocarbon group. However, a methyl group is preferred because of ease of synthesis.

As the component (d), a polyorganohydrogensiloxane having an average of more than two hydrogen atoms bonded to silicon atoms in one molecule is preferable. As the polyorganohydrogensiloxane, any of linear, branched, cyclic and the like may be used, and a mixture of these may be used, but it imparts good physical properties to the cured composition itself. In terms of doing, the following a ~
It is preferable to use a compound represented by C or a mixture thereof.

A. A branched polyorganohydrogensiloxane comprising (CH ₃ ) ₂ HSiO _1/2 and SiO _1/2 units, wherein the content of hydrogen atoms bonded to silicon atoms is 0.3 to 1.2% by weight of the molecular weight.

B. The following formula: (Where p is an integer of 2 to 100 and q is an integer of 0 to 100), wherein the content of the hydrogen atom bonded to the silicon atom is 0.5 to 1.6% by weight of the molecular weight. Polyorganohydrogensiloxane.

C. The following formula: (Where p is an integer of 1 to 100 and q is an integer of 0 to 100), wherein the content of the hydrogen atom bonded to the silicon atom is 0.5 to 1.6% by weight of the molecular weight. Polyorganohydrogensiloxane.

The amount of component (d) is such that the number of hydrogen atoms bonded to silicon atoms in component (c) is 0.5 to 4.0 per alkenyl group in component (c), Preferably, the amount is 1.0 to 3.0. If the number of hydrogen atoms is less than 0.5, curing of the composition will not proceed sufficiently, and the hardness of the cured product of the composition will be low. If it exceeds 4.0, the physical properties of the cured product of the composition will be low. descend.

On the other hand, as a curing catalyst for the addition reaction,
A catalyst that promotes an addition reaction between the alkenyl group of the component (c) and the hydrosilyl group of the component (d) is used, and examples thereof include platinum-based, rhodium-based, and palladium-based catalysts. In particular, platinum-based catalysts are preferably used,
Examples thereof include simple platinum, chloroplatinic acid, a platinum-olefin complex, a platinum-alcohol complex, and a platinum coordination compound.

In the case of such an addition-reaction-type liquid mixture, the uncrosslinked liquid silicone rubber undergoes a hydrosilylation reaction in the presence of a curing agent and a curing catalyst, which is crosslinked to cure into a rubbery state.

On the other hand, the coating liquid for crosslinking can be prepared by mixing an uncrosslinked liquid silicone rubber and / or silicone oil, and a curing agent and a curing catalyst which are not blended with the liquid mixture. . As the uncrosslinked liquid silicone rubber for preparing the coating liquid for crosslinking, those based on the liquid mixture can be used.

As the silicone oil, those having a functional group which reacts with the curing agent at a low temperature such as room temperature in the presence of a curing catalyst, and liquid polyorganosiloxanes having no functional group are used. Examples of the silicone oil composed of a liquid polyorganosiloxane having no functional group include polydimethylsiloxane or polymethylphenylsiloxane end-blocked by a trimethylsiloxy group.

Accordingly, as the uncrosslinked liquid silicone rubber or silicone oil, a curing agent or a curing catalyst used for preparing the crosslinkable coating liquid, a liquid admixture such as a condensation reaction type or an addition reaction type is used so as to be cured at a low temperature such as room temperature. An appropriate combination can be selected according to the curing mechanism of the product.

The amount of the curing agent used is generally 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the uncrosslinked liquid silicone rubber (and / or silicone oil). The amount of the curing catalyst used is generally 0.01 to 10 parts by weight per 100 parts by weight of the uncrosslinked liquid silicone rubber (and / or silicone oil). Rather than maintaining the appearance of the surface of the anticorrosion layer, the surface tension is 35 dyn / cm.
It is preferable to form the following anticorrosion layer.

In preparing the liquid mixture and the coating liquid for crosslinking, for example, a filler, a plasticizer, an antioxidant, a rust inhibitor, a fungicide, an antioxidant, an ultraviolet absorber, an ozone deterioration inhibitor,
Thickening agents or compounding agents such as thixotropic agents, pigments or coloring agents can be appropriately compounded as needed. The compounding amount is generally 1 to 90% by weight of the preparation.

The liquid mixture to be prepared preferably has such a viscosity that it does not drip when impregnated into a porous substrate. The viscosity of the cross-linking coating liquid is preferably about 0.01 to 1000 poise (25 ° C.) from the viewpoints of applicability and permeability to the room temperature cross-linkable coating material. Further, rather than forming a uniform anticorrosive layer with the applied amount of the cross-linking coating liquid as constant as possible, the applied amount can be determined by blending a pigment or colorant into the cross-linking coating liquid and by its color. It is preferable to do so.

The room temperature crosslinking type coating material can be obtained by impregnating a porous base material with a liquid mixture. The porous base material is a holding material for the liquid mixture, an auxiliary material for winding or bonding the room temperature cross-linkable coating material, a material for adjusting the thickness of the anticorrosion layer and a uniform material, and for alleviating impact and preventing damage. It functions as an anticorrosion layer protective material for preventing deterioration due to light blocking. Therefore, as the porous substrate, an appropriate material such as a woven fabric, a nonwoven fabric, or a felt made of various fibers can be used. The room temperature crosslinking type coating material can be formed into an appropriate form such as a tape, a sheet, a section, or the like.

The water-repellent anticorrosion layer of the present invention is formed by coating a room temperature crosslinkable coating material on a metal surface or an anticorrosion defect portion such as a defect portion of the anticorrosion layer by an appropriate method such as a winding method or a sticking method. The coating can be carried out by crosslinking the coating layer with a coating liquid for crosslinking. The crosslinking can proceed at a low temperature such as room temperature by combining the room temperature crosslinking type coating material and the coating liquid for crosslinking.

Therefore, the above-mentioned crosslinking is carried out by applying a coating liquid for crosslinking in advance on a metal surface or the like and then applying a room temperature crosslinking coating material thereon. Proceed with appropriate methods, such as a method of applying a coating on a metal surface, a method of applying a room temperature cross-linkable coating material to a metal surface and applying a coating solution for cross-linking to the coating layer, or a combination thereof. Can be. From the viewpoints of surface smoothness and freedom of coating application time of the room temperature cross-linkable coating material, it is preferable to apply a cross-linking coating solution after coating the room temperature cross-linkable coating material on a metal surface or the like. At the time of crosslinking, the rate of crosslinking can be increased by heating the coating layer of the room temperature crosslinking type coating material with a burner or the like.

Example 1 100 parts (parts by weight, hereinafter the same) of uncrosslinked liquid silicone rubber, 100 parts of white carbon (reinforcing agent), and 5 parts of tetraethoxysilane (curing agent) were kneaded with a planetary mixer, and the resulting mixture was polyester. Non-woven fabric (100 g / weight)
m ² ), roll it up into a roll
It was cut into a width to obtain a room temperature crosslinked type coating material having a basis weight of 1 kg / m ² .

On the other hand, uncrosslinked liquid silicone rubber 100
Parts, 30 parts of white carbon, 10 parts of aluminum powder (colorant), and 5 parts of dibutyltin dilaurate (curing catalyst) were kneaded with a planetary mixer to obtain a coloring type crosslinking coating liquid.

Next, the length of the above-mentioned room temperature crosslinking type coating material is 1
Cut a 50mm sample and cut it into a 100mm width and 1 length
50 mm and a thickness of 2 mm were adhered to a steel plate surface, and the above-mentioned coloring type crosslinking coating liquid was applied thereon at a rate of 100 g / m ² ,
C. for 24 hours to cure at room temperature to form a water-repellent anticorrosive layer. Make a grid-like cut in the water-repellent anticorrosion layer,
When the test was performed in accordance with JIS K 5400, the evaluation score (out of 10 points) was 10.

On the other hand, the above room temperature crosslinking type coating material is
To form a tape, which is wound on a steel pipe having a diameter of 100 mm at a wrapping rate of 55%, and then the above-mentioned coating solution for color-type crosslinking is applied thereon at a rate of 100 g / m ² , and at 23 ° C. It was kept at room temperature for 24 hours to form a water-repellent anticorrosive layer. At that time, 4 hours (23 hours) after the application of the coloring type crosslinking coating liquid.
C), the surface becomes tack-free, and the surface tension during tack-free is 27 dyn / cm (JIS K 6768).
Met.

The water-repellent anticorrosive layer was evaluated for watertightness, and good results were obtained. The water-repellent anticorrosive layer on the steel pipe was cut and forcibly peeled off, and the superposed portion was observed. The step portion of the portion was also securely filled, and the hole serving as the water channel was not formed at all.

Example 2 100 parts of uncrosslinked liquid silicone rubber, 100 parts of white carbon and 5 parts of dibutyltin dilaurate were kneaded with a planetary mixer, and the mixture was kneaded with a polyester nonwoven fabric (having a basis weight of 10%).
0 g / m ² ), and it is wound into a roll and
The sheet was cut to a width of 00 mm to obtain a room temperature crosslinking type coating material having a basis weight of 1 kg / m ² .

On the other hand, 100 parts of silicone oil, 30 parts of white carbon, 10 parts of aluminum powder (colorant),
Five parts of tetraethoxysilane were kneaded with a planetary mixer to obtain a coloring type crosslinking coating liquid.

A water-repellent anticorrosion layer was formed using the room temperature cross-linkable coating material and the colored cross-linking coating solution according to Example 1, and the characteristics thereof were examined. As a result, 10 points were obtained in a grid test, and 6 hours (23 ° C) after application of the coating solution for colored crosslinking
The surface became tack-free, and the surface tension during tack-free was 26 dyn / cm. Further, the watertightness was good, and no holes serving as water channels were formed.

[0055]

According to the present invention, a corrosion-resistant layer excellent in water repellency, corrosion resistance, heat resistance, uniformity of thickness and physical properties, and adhesion is provided. Can be easily and efficiently formed at a work site by low-temperature construction. Further, the formed anticorrosion layer is less likely to cause contamination, damage, wrinkles and floating, and is excellent in long-term durability of the anticorrosion effect.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B32B 25/20 B32B 25/20 C23F 11/00 C23F 11/00 B F16L 58/10 F16L 58/10 (72) Inventor Naoki Miwa Ibaraki, Osaka 1-1-2 Shimohozumi, Nichito Nitto Denko Corporation (72) Inventor Tetsuo Fujimoto 6-2-31 Roppongi, Minato-ku, Tokyo Toshiba Silicone Co., Ltd. (72) Inventor Shuji Chiba Roppongi, Minato-ku, Tokyo 6-2-3-1 Toshiba Silicone Co., Ltd. (56) References JP-A-2-48939 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35 / 00 B05D 7/24 302 C23F 11/00 F16L 58/10

Claims (5)

(57) [Claims] 1. A room temperature cross-linkable coating material obtained by impregnating a porous base material with a liquid mixture containing an uncrosslinked liquid silicone rubber as a main component and one of a curing agent and a curing catalyst on a metal surface or an anticorrosion defect. The coating was applied to form a coating layer, and the coating layer was cross-linked with a cross-linking coating liquid containing uncrosslinked liquid silicone rubber and / or silicone oil as a main component and containing the other of the above-mentioned curing agents or curing catalysts. A water repellent and anticorrosive layer characterized by the following. 2. The water-repellent anticorrosive layer according to claim 1, wherein the surface tension is 35 dyn / cm or less. 3. The water-repellent anticorrosion layer according to claim 1, which is formed by crosslinking a coating layer comprising a room-temperature crosslinking type coating material with a crosslinking coating solution containing a coloring agent. 4. A room temperature cross-linkable coating material obtained by impregnating a porous base material with a liquid mixture containing an uncrosslinked liquid silicone rubber as a main component and one of a curing agent and a curing catalyst; And / or a cross-linking coating liquid containing silicone oil as a main component and the other of the above-mentioned curing agent or curing catalyst. 5. The cross-linking coating solution contains a colorant.
The water repellent and anticorrosion treated material according to 1.