Bolt rust prevention device

Abstract

To provide a rust prevention device for a bolt that effectively prevents rusting of a part of the bolt exposed to the atmosphere. [Solution] The bolt rust prevention device 10 comprises an acrylic resin cap 12 that covers the entire portion of the bolt exposed to the atmosphere from the structure, an attachment means 14 for attaching the cap to the structure, and an oil gel 16 that is filled into the space formed by the cap and the structure, the oil gel containing chain polyurethane and paraffin-based oil.

Description

[Technical Field]

[0001] The present invention generally relates to a rust prevention device for bolts. In this invention, the term "bolt" includes a bolt head, a bolt shank, and a nut threaded onto the bolt shank. [Background technology]

[0002] In order to prevent the formation of rust on the bolts, it is known to cover the portions of the bolts that are exposed to the atmosphere with caps. Summary of the Invention [Problem to be solved by the invention]

[0003] However, the capping method creates a gap between the bolt and the inside of the cap, which can lead to condensation due to fluctuations in outside temperature, causing water droplets to adhere to the bolt, making it difficult to effectively prevent rust.

[0004] The present invention provides a novel bolt rust prevention device to solve the above problems. [Means for solving the problem]

[0005] In this invention, an oil gel developed by the inventor of the present invention is used (see Japanese Patent No. 6162911).

[0006] The oil gel disclosed in Japanese Patent No. 6162911 contains a linear polyurethane (A) and a paraffin-based oil (B), the linear polyurethane (A) being a linear polyurethane (A1) formed by polymerization of a linear diol (x) and a diisocyanate (y), the linear diol (x) being a compound in which two hydrogen atoms of a linear saturated hydrocarbon compound have been substituted with hydroxyl groups, the diisocyanate (y) being a compound in which two hydrogen atoms of a saturated hydrocarbon compound have been substituted with isocyanate groups, the paraffin-based oil (B) having a kinematic viscosity at 40°C of 20 mm 2 / s or more 100mm 2 / s or less paraffinic oil (B1), and the linear polyurethane (A1) is contained in an amount of 10% by mass or more and 50% by mass or less based on the total amount of the linear polyurethane (A1) and the paraffinic oil (B1).

[0007] Preferably, the linear polyurethane (A1) is contained in a proportion of 20% by mass or more and 40% by mass or less with respect to the total amount of the linear polyurethane (A1) and the paraffinic oil (B1). Also, preferably, the linear diol (x) is a hydrogenated polyisoprene diol (x1). Also, preferably, the number average molecular weight of the linear diol (x) is 1,000 or more and 5,000 or less. Also, preferably, the diisocyanate (y) is a diisocyanate (y1) in which two hydrogen atoms of an alicyclic saturated hydrocarbon compound are substituted with isocyanate groups. Also, preferably, the diisocyanate (y1) is norbornane diisocyanate (y1a). Also, preferably, the paraffinic oil (B) has a kinematic viscosity at 40°C of 85 mm 2 / s or more 95mm 2 / s or less paraffinic oil (B1a).

[0008] The oil gel is also made of a chain diol (x) in which two hydrogen atoms of a chain saturated hydrocarbon compound are substituted with hydroxyl groups, and a kinematic viscosity at 40°C of 20mm 2 / s or more 100mm 2 The first liquid contains a paraffinic oil (B1) with a kinematic viscosity of 20 mm / s or less, and a diisocyanate (y) in which two hydrogen atoms of a saturated hydrocarbon compound are substituted with an isocyanate group. 2 / s or more 100mm 2When the first liquid and the second liquid are mixed, the chain diol (x) in the first liquid and the diisocyanate (y) in the second liquid polymerize to form a chain polyurethane (A1), and the first liquid and the second liquid contain the chain diol (x), the diisocyanate (y), and the paraffin oil (B1) so that the chain polyurethane (A1) is formed in an amount of 10% by mass to 50% by mass based on the total amount of the chain polyurethane (A1), the paraffin oil (B1) contained in the first liquid, and the paraffin oil (B1) contained in the second liquid. The oil gel is also used as a pressure-resistant material for protecting electronic devices.

[0009] The rust prevention device for bolts described in claim 1 of the present application comprises an acrylic resin cap that covers the entire portion of the bolt that is exposed to the atmosphere from a structure, mounting means for mounting the cap to the structure, and an oil gel that fills a space formed by the cap and the structure, the oil gel containing a chain polyurethane (A) and a paraffin oil (B), the chain polyurethane (A) being a chain polyurethane (A1) formed by polymerization of a chain diol (x) and a diisocyanate (y), the chain diol (x) being a compound in which two hydrogen atoms of a chain saturated hydrocarbon compound are substituted with hydroxyl groups, the diisocyanate (y) being a compound in which two hydrogen atoms of a saturated hydrocarbon compound are substituted with isocyanate groups, the paraffin oil (B) having a kinematic viscosity at 40°C of 20 mm 2 / s or more 100mm 2 / s or less paraffinic oil (B1), and the linear polyurethane (A1) is contained in an amount of 10% by mass or more and 50% by mass or less based on the total amount of the linear polyurethane (A1) and the paraffinic oil (B1).

[0010] The rust prevention device for bolts described in claim 2 of the present invention is the rust prevention device described in claim 1, characterized in that the attachment means is a double-sided tape. [Effects of the Invention]

[0011] According to the bolt rust prevention device of the present invention, the bolt to be rust-prevented is covered with a special oil gel, preventing liquids such as moisture and water vapor from penetrating the space between the inner surface of the cap and the structure, thereby effectively preventing rust. The oil gel used in the present invention has been confirmed to function without problems in terms of weather resistance and corrosion resistance, even when used in coastal areas. Furthermore, because the oil gel used in the present invention is transparent, the rust condition of the bolt to be rust-prevented can be easily observed. Furthermore, the cap is made of acrylic resin, which has excellent transparency, making it easy to monitor the rust condition of the bolt to be rust-prevented. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall view showing a preferred embodiment of a bolt rust prevention device according to the present invention; [Figure 2] 2(a) is a cross-sectional view of the rust prevention device of FIG. 1, and FIG. 2(b) is a plan view of the rust prevention device of FIG. [Figure 3] FIG. 10 is a cross-sectional view showing another embodiment of the cap of the rust prevention device. [Figure 4] Figure 4(a) is a cross-sectional view showing yet another form of the cap of the rust prevention device, Figure 4(b) is a plan view of the cap of Figure 4(a), and Figure 4(c) is a cross-sectional view showing another form of the cap of the rust prevention device. [Figure 5] 10A and 10B are diagrams showing an example of a method for injecting oil gel into a cap. [Figure 6] FIG. 10 is a diagram showing another mode of use of the rust prevention device. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, a bolt rust prevention device according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is an overall view of the bolt rust prevention device according to a preferred embodiment of the present invention, Figure 2(a) is a cross-sectional view of the bolt rust prevention device of Figure 1, and Figure 2(b) is a plan view of the bolt rust prevention device of Figure 1. Figures 1 and 2 show an example of rust prevention for a bolt shank exposed to the atmosphere from a structure and a nut threaded onto the bolt shank.

[0014] The bolt rust prevention device generally designated by reference numeral 10 in Figures 1 and 2(a) includes a cap 12 that covers the entire exposed portion of the bolt and nut structure to be rust-prevented.

[0015] The cap 12 is made of acrylic resin. It is preferable that the cap 12 is transparent so that the rust state of the bolt can be easily monitored, and acrylic resin is used because it has good transparency.

[0016] The cap 12 shown in FIGS. 1 and 2 has a cylindrical side wall 12a, a top wall 12b that closes the top, and an open bottom 12c.

[0017] The cap 12 may have a rounded top wall 12b as shown in Fig. 3. Alternatively, the cap 12 may have a shape other than those shown in Figs. 1 to 3, as long as it can cover the entire exposed portions of the bolt and nut.

[0018] The cap 12 is attached to the structure with double-sided tape 14. In order to maintain the airtightness of the space inside the cap 12, it is preferable to use an airtight double-sided tape 14 (for example, VHB tape from 3M).

[0019] In the above example, the means for attaching the cap 12 to the structure is the double-sided tape 14, but other suitable attachment means (for example, fasteners such as screws) may also be used.

[0020] To facilitate attachment of the cap 12 to a structure, a flange 12d may be provided on the bottom of the side wall 12a of the cap 12 (see FIGS. 4(a) and 4(b)). Alternatively, for example, as shown in FIG. 4(c), a protrusion 12a1 may be provided near the bottom of the outer surface of the side wall 12a of the cap 12, and the protrusion 12a1 may be configured to snap into a recess 12d1 provided on the inner surface of the flange 12d, or the cap 12 may be configured to be attached to a structure in any other appropriate manner.

[0021] The space formed by the cap 12 and the structure is filled with an oil gel 16.

[0022] Oil gel 16 is an oil gel containing linear polyurethane (A) and paraffinic oil (B). It is presumed that the oil gel is formed due to the similarity in molecular structure between the linear saturated hydrocarbon compound contained in the paraffinic oil (B) and the linear polyurethane (A). Unlike ordinary oil gels in which oil is held in the gaps of a three-dimensional network structure, oil gel 16 is presumed to be formed by the linear portions of the linear saturated hydrocarbon compound contained in the paraffinic oil (B) and the linear portions of the linear polyurethane (A) loosely bonding together through hydrophobic interactions.

[0023] The oil gel 16 is highly flexible because the chain saturated hydrocarbon compounds contained in the paraffin oil (B) and the chain polyurethane (A) are weakly bonded together. Furthermore, when a strong force is applied to the oil gel 16, the bonds between the chain saturated hydrocarbon compounds and the chain polyurethane are broken, allowing each molecule to move freely. Therefore, despite having a fixed shape, the oil gel 16 behaves similarly to an incompressible fluid such as insulating oil. Therefore, even if high water pressure is applied to the oil gel 16, it has the effect of dispersing and balancing the water pressure throughout the oil gel 16 (hydraulic pressure balancing effect).

[0024] The oil gel 16 exhibits excellent pressure resistance due to this hydraulic pressure balancing effect. In other words, even if high water pressure or pressure shock acts on the oil gel 16, the pressure can be transmitted evenly to each part of the various devices, thereby effectively preventing physical damage to the various devices and allowing them to operate normally.

[0025] In addition, the oil gel 16 has the shape-retaining property to maintain its shape, so there is no need for a protective coating or oil-tight structure to cover various devices. Furthermore, the oil gel 16 is highly flexible and can be peeled off even after hardening, allowing for maintenance of various devices.

[0026] The oil gel 16 in this invention is a dispersion system with paraffin oil (B) as the dispersion medium and linear polyurethane (A) as the dispersoid, and exhibits properties intermediate between a liquid and a solid. Therefore, the oil gel 16 in this specification does not include liquids or rubber-like materials (elastic bodies).

[0027] The chain polyurethane (A), which is one component of the oil gel 16, is a chain polyurethane (A1) formed by polymerization of a chain diol (x) and a diisocyanate (y). A polyurethane with a chain structure is formed by polymerizing di-substituted compounds, namely, the chain diol (x) and the diisocyanate (y).

[0028] The chain diol (x) is a compound in which two hydrogen atoms of a chain saturated hydrocarbon compound are substituted with hydroxyl groups. Among the chain diols, a chain diol having a structure in which two hydrogen atoms bonded to carbon atoms located at both ends of a chain saturated hydrocarbon compound are substituted with hydroxyl groups (chain diol with both ends) is preferred.

[0029] The chain diol (x) is preferably a hydrogenated polyisoprene diol (x1). Since the hydrogenated polyisoprene diol has a polyolefin chain, it is thought that an oil gel is formed due to hydrophobic interactions with the chain saturated hydrocarbon compounds in the paraffin-based oil. In addition, since the hydrogenated polyisoprene diol (x1) does not contain a carbon-carbon double bond, the polyurethane obtained by polymerization is less likely to become rubbery (elastomerized), which is advantageous in that a soft oil gel can be formed.

[0030] The hydrogenated polyisoprene diol (x1) is preferably a hydrogenated polyisoprene diol having a hydroxyl group content of 0.80 mol / kg or more and 1.0 mol / kg or less. Furthermore, the hydrogenated polyisoprene diol (x1) is preferably a hydrogenated polyisoprene diol having a bromine number of 1 g / 100 g or more and 10 g / 100 g or less. The hydroxyl group content means a value measured in accordance with the measurement method described in JIS K1557, and the bromine number means a value measured in accordance with the measurement method described in JIS K0070.

[0031] The number average molecular weight of the chain diol (x) is preferably 1,000 or more and 5,000 or less, and more preferably 2,000 or more and 3,000 or less. This number average molecular weight means a value measured in accordance with the method described in ASTM D2503.

[0032] When the number average molecular weight of the chain diol (x) is in the above range, the kinematic viscosity at 40°C is 20 mm 2 / s or more 100mm 2 It is believed that the structure (chain length) of the chain saturated hydrocarbon compound, which is the main component of the paraffinic oil (B1) having an average molecular weight of 1,000 or less, and the chain portion of the chain polyurethane (A1) are similar to each other, making it easier to exert hydrophobic interactions. The paraffinic oil (B1) is mainly composed of a chain saturated hydrocarbon compound having an average molecular weight of 1,000 or less. In order to approximate the number average molecular weight of the carbon chain of this chain saturated hydrocarbon compound, it is preferable to set the number average molecular weight of the chain diol (x) within the above range.

[0033] Diisocyanate (y) is a compound in which two hydrogen atoms of a saturated hydrocarbon compound are substituted with isocyanate groups. Diisocyanate (y) is preferably diisocyanate (y1) in which two hydrogen atoms of an alicyclic saturated hydrocarbon compound are substituted with isocyanate groups.

[0034] Furthermore, the diisocyanate (y1) is preferably norbornane diisocyanate (y1a). The polyurethane formed by polymerization of norbornane diisocyanate (y1a) with the chain diol (x) exhibits high transparency both visually and electromagnetically, and can transmit infrared light, visible light, and ultraviolet light with almost no loss. The norbornane diisocyanate (y1a) may be 2,5-norbornane diisocyanate or 2,6-norbornane diisocyanate.

[0035] When forming the polyurethane (A1) by polymerization, it is preferable to react the chain diol (x) and the diisocyanate (y) in equimolar amounts.

[0036] The paraffinic oil (B) means an oil (for example, paraffinic process oil) whose main component is paraffin (a chain saturated hydrocarbon compound). The paraffinic oil (B) has a kinematic viscosity of 20 mm at 40°C. 2 / s or more 100mm 2 Particularly, the kinematic viscosity at 40°C is 85mm / s or less. 2 / s or more 95mm 2 The kinematic viscosity at 40°C is a value measured in accordance with the measurement method described in JIS K2283. The kinematic viscosity of paraffinic oil is correlated with the molecular weight (which can be considered as the chain length of the carbon chain) of the chain saturated hydrocarbon compound that is the main component. In addition, when the kinematic viscosity at 40°C is 100 mm 2By using a paraffinic oil (B1) having a number average molecular weight of 1,000 to 5,000, an oil gel with excellent pressure resistance is formed, particularly with a linear polyurethane having a linear diol unit with a number average molecular weight of 1,000 to 5,000. Furthermore, when obtaining an oil gel by a two-component mixing method, mixing can be easily performed at room temperature (15°C to 45°C) without using a stirring device such as a stirrer.

[0037] The weight average molecular weight of the paraffinic oil (B) is preferably from 265 to 1060, and more preferably from 430 to 630. This weight average molecular weight refers to a value determined by gel permeation chromatography (GPC) in terms of polystyrene using monodisperse polystyrene as a standard.

[0038] In the oil gel 16, the chain polyurethane (A1) is contained in a proportion of 10% by mass or more and 50% by mass or less relative to the total amount of the chain polyurethane (A1) and the paraffin-based oil (B1). By setting the proportion within the above range, an oil gel with excellent pressure resistance and waterproof properties can be formed. In order to further improve the pressure resistance and waterproof properties, it is preferable that the chain polyurethane (A1) is contained in a proportion of 20% by mass or more and 40% by mass or less relative to the total amount of the chain polyurethane (A1) and the paraffin-based oil (B1).

[0039] The oil gel 16 can be produced by a so-called two-liquid mixing method. For example, it is produced using an oil gel former that combines a first liquid containing a chain diol (x) and a paraffinic oil (B1) with a second liquid containing a diisocyanate (y) and a paraffinic oil (B1). When the first liquid and the second liquid are mixed, the chain diol (x) in the first liquid and the diisocyanate (y) in the second liquid polymerize to form a chain polyurethane (A1).

[0040] In this oil gel former, the first and second liquids may contain the chain diol (x), diisocyanate (y), and paraffinic oil (B1) so that the chain polyurethane (A1) is formed in an amount of 10% by mass to 50% by mass based on the total amount of the chain polyurethane (A1), the paraffinic oil (B1) contained in the first liquid, and the paraffinic oil (B1) contained in the second liquid. A known reaction catalyst (for example, an organotin compound such as dibutyltin dilaurate) may be added to the first liquid to promote polymerization (and thus gelation).

[0041] The specific details of the chain-terminated diol (x), diisocyanate (y), and paraffin-based oil (B) are as described above. The first and second liquids can be mixed even at room temperature (15°C to 45°C) (without heating such as in a water bath), and a chain-like polyurethane (A) is formed by a polymerization reaction. This allows for the production of an oil gel 16 formed from the chain-like polyurethane (A) and the paraffin-based oil (B).

[0042] The mixing method is not particularly limited. For example, the first liquid and the second liquid are measured, placed in a plastic bag with a zipper, and mixed inside the plastic bag. When mixing, it is preferable to place the second liquid and then the first liquid in the plastic bag in this order and mix them.

[0043] The mixing temperature is not particularly limited. However, it is necessary that the temperature be such that the first liquid and the second liquid are sufficiently compatible and mixed. Specifically, the mixing temperature is preferably 15°C or higher and 45°C or lower, and more preferably 15°C or higher and 25°C or lower.

[0044] As time passes, the reaction between the chain diol (x) and diisocyanate (y) progresses in the mixed solution of the first and second solutions, causing it to gel. It takes about 3 hours for the mixed solution to gel to the point where it does not leak, and about 24 hours for it to gel completely.

[0045] The space within the cap 12 is filled with oil gel 16, for example, as follows: The cap 12, which has an oil gel injection hole 12b1 formed in the top wall 12b, is attached to the structure so as to cover the entire exposed portion of the bolt to be rust-proofed (see FIG. 5). Then, the first liquid and the second liquid are mixed to form oil gel 16, and the oil gel 16 is injected through the oil gel injection hole 12b1 using a syringe (not shown). Once the space is filled with oil gel 16, the injection is stopped.

[0046] Alternatively, the first liquid and the second liquid may be mixed to form an oil gel 16, the oil gel 16 may be filled into the cap 12, and then the cap 12 may be attached to the structure so as to cover the entire exposed portion of the bolt to be rust-proofed.

[0047] Alternatively, the cap 12 may be pre-filled with an oil gel 16 of suitable consistency (for example, similar to miso paste) and the opening 12c may be sealed with a seal (not shown). When in use, the seal may be removed and the cap 12 may be attached to the structure so as to cover the entire exposed portion of the bolt.

[0048] In any of the above methods, it is expected that a small amount of the filled oil gel 16 will leak from the cap 12. In such a case, the leaked oil gel 16 is removed using an appropriate tool such as a scraper.

[0049] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the utility model registration claims, and it goes without saying that these modifications are also included within the scope of the present invention.

[0050] For example, the above embodiment has been described in relation to an example of rust prevention for a bolt shank exposed to the outside of a structure and a nut threaded onto the bolt shank, but as shown in Figure 6, it may also be used to rust prevention for a bolt head exposed to the outside of a structure. [Explanation of symbols]

[0051] 10-volt rust preventative 12 Caps 12a Peripheral wall 12a1 protrusion 12b Top wall 12b1 Oil gel injection hole 12c aperture 12d flange 12d1 recess 14 Double-sided tape (mounting means) 16 Oil Gel

Claims

1. A rust prevention device for bolts, an acrylic resin cap that covers the entire exposed portion of the bolt structure to the atmosphere; attachment means for attaching the cap to the structure; an oil gel filled in a space formed by the cap and the structure; The oil gel contains a linear polyurethane (A) and a paraffinic oil (B), the linear polyurethane (A) is a linear polyurethane (A1) formed by polymerization of a linear diol (x) and a diisocyanate (y), the linear diol (x) is a compound in which two hydrogen atoms of a linear saturated hydrocarbon compound are substituted with hydroxyl groups, the diisocyanate (y) is a compound in which two hydrogen atoms of a saturated hydrocarbon compound are substituted with isocyanate groups, the paraffinic oil (B) has a kinematic viscosity at 40°C of 20 mm ２ / s or more 100mm ２ / s or less, and the linear polyurethane (A1) is contained in an amount of 10% by mass or more and 50% by mass or less based on the total amount of the linear polyurethane (A1) and the paraffinic oil (B1). A rust prevention device characterized by:

2. 2. The rust prevention device according to claim 1, wherein the attachment means is a double-sided tape.

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