JPH0369808A - Anticorrosion method for bolt and nut and and protective cap - Google Patents

Abstract

PURPOSE:To make it possible that bolt and nut do not burn, to increase work efficiency, and to prevent drop of them by wrapping a projection section of bolt and nut with a protective cap made of glass fiber which is filled with anticorrosive in the inside, provided with a scale-shaped mica film on the surface, and the net structure and whose inside can be seen. CONSTITUTION:Anticorrosive 22 such as non-dry ceiling agent is filled in the inside of caps 14, 16 which are made of nonflammable, durable, and transparent glass fiber and wrap projection sections of a bolt 2 and nut 4 at an adequate space from the side, upper section, and lower section. The caps 14, 16 have the net structure made of glass fiber and scale-shaped mica film 17 on the surface..The bolt and nut, therefore, have resistance against fire, are light weight, can be handled with case, provide high work efficiency, and do not drop readily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for preventing corrosion of pollutants and nuts, and a protective cap used therein.

[Prior art and problems to be solved by the invention] Conventionally,
2. Description of the Related Art When constructing various structures such as concrete structures and steel structures, bolts and nuts are widely used to connect members.

Therefore, particularly in the case of outdoor structures, the bolts and nuts are exposed to the outside air, and if left as is, corrosion will progress over a long period of time, causing a problem in that the predetermined bonding strength will be lost. For this reason, in order to prevent corrosion of bolts and nuts, it has been conventional practice to apply anti-corrosion coating to the protruding parts (exposed parts).

However, since bolts and nuts have complicated shapes, the coating work efficiency is not good, and the coating tends to be thinner at corners, reducing anticorrosion performance. Furthermore, since it is difficult to form such a thick coating film with painting, long-term corrosion protection cannot be expected.

Therefore, in order to provide a thick anti-corrosion layer to the protruding parts of bolts and nuts, a protective cap with a shape corresponding to the protruding parts of the bolts and nuts is prepared, and the cap is filled with anti-corrosion.
A method has been proposed in which the cap is placed over the bolt/nut protrusion after being accommodated, the anticorrosive material is hardened in this state, and the cap is left attached as is.

However, conventional caps are made of metal such as aluminum or stainless steel and are opaque, so even if a void is created inside the cap when the cap is placed over the protruding part of a bolt or nut and the cap is filled with anti-corrosive material, the void remains. could not be confirmed, and therefore a good anticorrosion layer could not be formed in some cases.

Furthermore, because this method leaves the cap attached as is, conventional metal caps have a relatively large weight, so there is a risk that they may fall off after a long period of time due to shrinkage of the anti-corrosive material or vibrations transmitted from the structure. Yes, vibration is particularly noticeable when the structure is related to transportation (for example, structures attached to railways, subways, and roads).
Falling caps create a danger to traffic.

Therefore, caps made of plastic such as polypropylene are used instead of metal caps, but when the cap is made of plastic, there is a problem that it is easily flammable and dangerous in the event of a fire.

Therefore, in view of the above-mentioned problems of the prior art, the present invention provides a structure that does not burn in the event of a fire, has high work efficiency, is difficult to prevent the protective cap from falling off, is safe even if it falls, and has a sufficiently thick anti-corrosion coating. It is an object of the present invention to provide a method for preventing corrosion of bolts and nuts, and a protective cap used in the method for preventing corrosion of bolts and nuts.

[Means for Solving the Problems] According to the present invention, the above object is to cover the protruding portions of bolts and/or nuts connected to a structure from the structure with a film-like coating made of scaly mica. The protrusion is covered with a glass fiber protective cap having a transparent mesh structure on the surface, and the protrusion is covered by filling the cap with anticorrosive material in advance. , a corrosion prevention method for bolts and nuts.

Further, according to the present invention, the above object is to provide a protective cap made of glass fiber that covers the protruding portion of a bolt and/or nut connected to a structure from the structure through an anticorrosive layer. A protective cap is characterized in that it has a mesh structure that allows the interior to be seen through, and is coated with a film-like coating made of scaly mica on its surface.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are schematic process diagrams showing an embodiment of the method of the present invention.

In these figures, 2 is a bolt, 4 is a nut, and 6 and 8 are concrete plates that are structural members connected by these bolts and nuts. 10 is a washer placed between the head of the bolt 2 and the concrete plate 6 during this connection, and 12 is a washer placed between the nut 4 and the concrete plate 8 during the above connection. 14 is a protective cap for the protrusion on the bolt head side used in carrying out the method of the present invention, and 16 is a protective cap for the protrusion on the bolt/nut fitting side used in carrying out the method of the present invention.

The cap 14 is made of a mesh structure, which will be described later, and has a shape that allows it to cover the bolt head protrusion from the sides and top with an appropriate distance (for example, a minimum of 2 mm).

A film-like coating 17 made of scaly mica, which will be described later, is applied to the surface of the mesh structure.

In addition, the cap 16 is arranged such that the protrusion on the bolt/nut fitting side is set at an appropriate distance from the side and lower part (for example, at least 2 mm).
) consists of a mesh structure having a shape that can be covered with. A film-like coating 17 made of scaly mica, which will be described later, is applied to the surface of the mesh structure.

First, as shown in FIG. 1(a), the concrete plates 6 and 8 are connected using bolts 2, nuts 4, and washers 10.12, and the cap 14 for the bolt head side protrusion and the bolt/nut fitting side are A cap 16 for the protrusion is prepared.

In addition, anti-corrosive material 2 is placed inside the cap 14 and the cap 16 in advance.
Fill it with 2. It is desirable that the amount of anti-corrosion agent filled is slightly larger than the amount that can completely fill the cavity when the bolt or nut is covered with the cap.

Next, as shown in FIG. 1(b), the bolt head side protrusion is covered with the cap 14 from above, and the bolt/nut fitting side protrusion is covered with the cap 16 from below. Leave in this state to allow the anticorrosion to harden naturally.

Incidentally, the caps 14 and 16 of the present invention have a mesh structure and the inside can be seen through, so that the state of filling of the anticorrosive material can be visually checked, and it is possible to check for any remaining in the void, and take appropriate measures.

As the corrosion protection material 22, conventionally used materials such as epoxy resin-amide sealants, polyisocyanate-polyol sealants, non-drying oil sealants, etc. can be used. In addition, in order to prevent it from falling off due to external forces such as vibrations after curing and to make it flame retardant, it is necessary to use organic-inorganic materials that have appropriate flexibility and a relatively low specific gravity (for example, 1.4 or less). Preferably, anticorrosion-based or inorganic anticorrosive agents include those having the following formulations.

(1) (a) Acrylic emulsion resin and/or aliphatic polyamine curing agent...5 to 50 parts by weight (solid content equivalent), (2) Cement...20 to 70 parts by weight, etc.)...5 ~40 parts by weight, and (4) 0.5 to 3 parts by weight of a fibrous material (for example, glass fiber with a length of 2 to 20 mm), and further contains rust preventive pigments, extender pigments, and additives as necessary. An anticorrosive material with a viscosity of 20 to 1,000 boids, which is made by adding water to a mixture of the following.

Next, the protective cap of the present invention as described above will be explained in more detail.

The protective cap is made of glass fiber because it is nonflammable, durable, and transparent. Further, the protective cap has a mesh structure having eyes large enough to allow the inside to be seen through.

For example, the thickness of the protective cap is preferably 0°1-3
The roughness of the mesh is preferably about 20 to 20 mm.
It is about 0 meshes. There is no particular restriction on the form of the mesh, and examples include those shown in FIGS. 2(a) to 2(C). FIG. 2(a) is a plain weave net, FIG. 2(b) is a twill weave net, and FIG. 2(c) is a tatami edge net. Furthermore, a mesh nonwoven fabric or the like can also be used.

The protective cap of the present invention has appropriate strength so as not to deform when the anticorrosive material is filled inside the cap.
In addition, in order to prevent the anti-corrosion solvent etc. from protruding through the cap mesh, it is non-flammable and has a color or transparency that allows the inside to be seen through, and is made of scaly mica that is difficult to soften in order to have a blocking effect. A film-like coating 17 is applied.

Note that the film-like coating can be applied to the inside, outside, or both sides of the cap. In order to reduce the gloss of the cap (and thus reduce operator fatigue), it is desirable to apply it on the inside.The thickness of the film-like coating is suitably about 40 to 300 μm.

Next, a method for applying a film-like coating will be explained.

Scale-like mica powder with a diameter of about 0.1 to 2 mm and an aspect ratio of 100 or more, preferably 200 or more is dispersed in water and then continuously formed to form a film-like film of aggregated mica, which is then bonded to an inorganic adhesive. It can be applied by laminating and adhering it to a glass fiber cloth via. In this way, the cap of the present invention is formed using a glass fiber cloth coated with a film-like coating made of scaly mica.

The flaky mica may be either natural mica or synthetic mica, but synthetic M mica is preferable because it has better transparency, flexibility, and heat resistance.

For example, synthetic mica is represented by the following general formula.

Xo,s ,, + Yz ,,s Z40 +oFz
[However, X is Na", K", Rb", Ca"B
a” or Sr”, Y is M g t +F e”,
N i ”, Mn”, A I ”°, Fe”
+ or Li3, Z is (A l ”, S L ”)
.

A particularly preferred synthetic mica is KMga (AtS i *
O+. ) Fluorine phlogopite denoted by F2, KMg2. s
They are fluorine potassium tetrasilicon mica represented by (S i40+o)Fa, and taeniolite represented by KMga Li (Si40va)F2.

The inorganic adhesives include silicate adhesives such as sodium silicate, potassium silicate, and lithium silicate, silica sol adhesives, alumina sol adhesives, and aluminum phosphates such as dibasic aluminum phosphate. Typical examples include aluminum phosphate adhesives, but aluminum phosphate adhesives consisting of dibasic aluminum phosphate and a magnesium oxide hardener are particularly excellent in terms of adhesiveness, transparency, flexibility, etc. It is preferable because there is.

It is desirable to form a film-like film made of scaly mica using the method described above, since the mica overlaps homogeneously and prevents the anticorrosion from leaking from the protective cap.
It is also possible to form a film-like coating by applying an inorganic paint containing scaly mica. In the case of an inorganic paint, the diameter of the scaly mica is preferably from several tens of micrometers to several hundred micrometers.

[Effects of the Invention J According to the present invention as described above, since a protective cap made of glass fiber with a mesh structure on the surface of which is coated with a specific non-combustible film is used, there is no danger of fire and the cap is It is light and easy to handle, has good workability, and is difficult to fall off, so even if it falls, there is little danger. In addition, since the inside of the protective cap can be seen through, the filling state of the anticorrosive material can be visually checked, and it is possible to check for any remaining in the void.

2: Bolt, 4: Natsu, 6.8: Concrete board, 10.12: Washer, 14.16: Protective cap, 17: Film-like film, 22: Anti-corrosion.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are schematic process diagrams showing an embodiment of the method of the present invention. FIGS. 2(a) to 2(c) are views showing the form of the mesh of the cap of the present invention.

Claims (2)

[Claims] (1) The protruding parts of the bolts and/or nuts connected to the structure are covered with a glass fiber protective cap that has a transparent network structure and whose surface is coated with a film-like coating made of scaly mica. A method for preventing corrosion of bolts and nuts, characterized in that the protrusions are covered by encasing the protrusions and the cap is filled with an anticorrosive material in advance. (2) A protective cap made of glass fiber that covers the protrusion of a bolt and/or nut connected to a structure from the structure via an anticorrosive layer, and has a mesh structure that allows the inside to be seen through. A protective cap characterized in that the surface thereof is coated with a film-like coating made of scaly mica.