JPH0796801B2 - Metal grating and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is widely used for applications such as groove lids and water collecting basins, and is made of metal such as steel, casting, cast iron, stainless steel, and the like. The object of the invention is to provide a sound-proof / vibration-proof and anti-slip performance with a coating film coated on the surface of the metal material.

[Conventional technology]

FIG. 2 exemplifies a grating 1 to which the present invention is applied. Left and right vertical plates or L-shaped side frames 2.2 are welded to both side frames 2.2 at equal intervals in the front-rear longitudinal direction. A number of flat bars 3 and these flat bars 3
And a twist bar 4 welded in the longitudinal direction across the upper surfaces of the above.

On the other hand, a non-slip paint containing an aggregate is known, and it is known that the anti-slip coating film is formed by applying the paint to the surface of steel stairs or the like.

[Problems to be Solved by the Invention]

Therefore, even in the case of grating, it is conceivable to coat the outer surface with a non-slip paint. However, in the case of grating, there are problems of slip resistance and particularly soundproofness in a wet state of lubrication. When the vehicle passes over the groove 5 on the road with the grating 1 laid, a considerable metallic rattling sound is produced. This rattling sound also reverberates in the concrete groove, and noise countermeasures are essential.

Therefore, it has been proposed to attach a separate rubber sheet material or the like between the contact surfaces of the groove 5 and the grating 1, but it is expensive because the rubber sheet material is separately prepared, and it is troublesome to lay and troublesome. is there.

It is an object of the present invention to obtain a grating in which the coating film has soundproof performance and antislip performance at the time of applying a paint finish for rust prevention, design coloring, etc., paying attention to such circumstances.

[Means for Solving the Problems]

As shown in FIG. 1, the grating of the present invention comprises a synthetic rubber varnish of 20 to 70% by weight and an average particle diameter of 0.02 to 3.0 mm.
The coating material containing 5 to 80% by weight of the aggregate 7 is coated on the entire outer surface of the metallic grating to form the coating film 6. Therefore, the coating film surface 6a of the coating film 6 is uneven due to the interposition of the aggregate 7.

If only the anti-slip performance is to be obtained, it is sufficient to form the coating film 6 only on the outer surface on the upper side of the grating 1, but this does not provide soundproof performance on the contact surface with the groove 5 and the contact surface between the gratings. Therefore, it should be noted that the coating film 6 is formed on the entire outer surfaces of the metal materials 2, 3, and 4 that form the grating. Therefore, in the method of the present invention, a coating material containing the above-mentioned synthetic rubber-based varnish and an aggregate is prepared, and grating is dipped in this coating material bath to coat the entire outer surface with the coating film. The thickness of the coating after drying is 0.3 to 1.5 m
m, generally set to around 1.0 mm. Although the immersion coating method is advantageous in terms of productivity, it may be a spraying method or a roller coating method, and the drying method may be either forced drying or natural drying.

As synthetic rubber, in addition to nitrile rubber, acrylic rubber,
Examples include urethane rubber, butyl rubber, butadiene rubber, and styrene butadiene rubber. In this respect, in the case of galvanized steel grating, the adhesion of the coating material to the surface thereof is generally poor. Therefore, in the conventional coating method for such steel grating, as a pretreatment, a primer coating film with good adhesion such as a wash primer is formed, or a chemical conversion treatment is performed before the coating. Also in the present invention, any synthetic rubber can be used as long as such pretreatment is carried out. Further, in the case of a steel grating which is not galvanized, styrene-butadiene rubber can be used alone.

Further, in the case of galvanized steel grating, it is optimal to add a phenolic resin to the nitrile rubber in order to obtain good adhesion and a tough coating film while omitting the pretreatment. That is, the above aggregate is mixed with a synthetic rubber varnish containing 50 to 150 parts by weight of a phenol resin with respect to 100 parts by weight of nitrile rubber, in the above-mentioned proportion. Instead of the phenol resin, a resin compatible with the synthetic rubber such as an epoxy resin and a coumarone resin may be used.

If the content of the synthetic rubber varnish is less than 20% by weight, the soundproofing effect is reduced, and if it exceeds 70% by weight, the slip resistance is poor and the hardness of the coating film cannot be maintained.

The aggregate 7 improves the wear resistance of the coating film 6 and finishes the coating film surface in a concavo-convex shape to ensure slip resistance in a wet state wet with rain. Such aggregates include silica sand, ceramic sand,
Hard and acute-angled materials such as silicon carbide and corundum, hard spherical materials such as alumina, glass beads and resin powder, lightweight hollow materials such as silica balloons and glass balloons,
Use rubber chips such as urethane chips and elastic ones such as resin powder that have an average particle size of 0.02 to 3.0 mm. Of these, particularly hard aggregates having a small particle size improve the wear resistance of the coating film, and aggregates having a large particle size improve the slip resistance of the coating film. Therefore, the aggregate may be used alone, but preferably, the hard aggregates are mixed with each other having a large or small particle size, and the hard and sharp aggregates such as silica sand and the hollow and lightweight large aggregates such as silica balloons are preferable. It is possible to mix an aggregate having a particle size, or a hard aggregate as described above and an elastic aggregate such as a rubber chip.

If the mixing ratio of the aggregate in the coating film is less than 5% by weight, the anti-slip property cannot be achieved, and the unevenness of the coating film surface becomes uneven, which is not aesthetically preferable. If the inorganic aggregate also exceeds 80% by weight, the fluidity of the coating becomes poor, making it difficult to apply a coating method such as dipping to a complex-shaped grating, and it becomes impossible to maintain the strength of the coating. Therefore, the mixing ratio of the aggregate is set to 5 to 80% by weight. For lightweight aggregates such as urethane foam, workability is similarly deteriorated if it exceeds 30% by weight.

That is, the composition of the paint to be adjusted is 20 to 70% by weight of synthetic rubber varnish (6 to 20% as solid content), preferably 30 to 40% by weight (9 to 12% as solid content), 5 to 80% by weight of aggregate. %, 1 to 30% by weight of pigment, 0 to 10% by weight of solvent, and 0 to 5% by weight of auxiliaries such as stabilizer, anti-precipitation agent, dispersant and defoaming agent.

Examples of the pigment include titanium oxide, red iron oxide, chromium oxide,
Examples include inorganic pigments such as chrome yellow, carbon black and iron oxide green, and azo-based and phthalocyanine-based inorganic pigments.

〔The invention's effect〕

According to the present invention, since the entire outer surface of the metallic grating is coated with the coating film by the dip coating method or the like, the grating and the concrete groove and the gratings are always in contact with each other through the coating film in the installed state. Moreover, since the coating film is made of rubber, it exerts a rich vibration and soundproofing effect, and unevenness of the coating film surface due to the interposition of aggregates also works effectively. Therefore, a high-pitched metallic sound is not produced even when the vehicle passes, and the amplification of rattling sound in the groove is effectively suppressed.
It is advantageous for preventing noise generation.

The aggregate improves the abrasion resistance of the coating, especially when it is an inorganic aggregate. Moreover, when the nitrile rubber and the phenol resin are used in combination, the adhesion of the coating film can be well ensured without pretreatment of the galvanized steel grating, and a tough coating film can be obtained. Suitable for coating. Furthermore, since the amount of aggregates mixed is set to 5 to 80% by weight, the surface of the coating film is finished as uneven as possible, and the uneven surface becomes a coating film with a high friction coefficient. There is. Therefore, not to mention the anti-slip function in the dry state of the coating film, effective and reliable anti-slip performance is exhibited even in the wet state in the rain, and the slip prevention of the vehicle and the runner can be excellently achieved.

Further, according to the grating of the present invention, not only enhance the design effect by providing a colored coating film on the entire outer surface, such as a coating film of green, for example, to provide a color scheme that matches the lawn of the park or gutter,
The anticorrosion effect on the entire outer surface is enhanced

Example 1 A synthetic rubber-based varnish containing 100 parts by weight of a phenol resin with respect to 100 parts by weight of nitrile rubber, an inorganic aggregate containing silica sand, silicon carbide, ceramic sand, etc. having a particle size distribution of several types, and a green pigment. A coating material of the following composition consisting of (iron oxide green and silica powder as an extender pigment), a solvent (methyl ethyl ketone), and auxiliary agents such as a precipitation inhibitor and a dispersant, has a viscosity of 25500 CPS (B-type viscometer at 20 ° C). Adjust to. It consists of the side frame 2, flat bar 3 and twist bar 4 described above, and has a height of 4 cm, a width of 30 cm, a total length of 100 cm,
A steel grating 1 having a total weight of 11 kg as shown in FIG. 2 was prepared, and the grating 1 was dipped in the adjusted coating material bath and then pulled up and dried at a temperature of 80 ° C. for 10 minutes to prepare each metal material 2.3. -A coating film 6 having a thickness of 1.0 mm was formed on the entire outer surface of 4. In FIG. 1, the coating surface of coating 6
6a is formed in an uneven shape by interposing the aggregate 7.

Composition of coating material% by weight Synthetic rubber varnish 33.5 Inorganic aggregate 45.0 Pigment 15.5 Solvent 5.3 Auxiliary agent 0.7 Particle size distribution of said aggregate mm% 0.5 or more ... 16.2 0.3 to less than 0.5 ... 43.5 0.3 or less ... ..... 40.3 [Example 2] The same as Example 1 except that the composition of the coating material was changed as follows.

Composition of coating material wt% Synthetic rubber varnish 48.7 Inorganic aggregate 20.0 Pigment 22.6 Solvent 7.7 Auxiliary agent 1.0 [Comparative example] As a comparative example, a conventional uncoated grating in which the coating film 6 is not coated is prepared.

The coating film 6 of the grating obtained in Examples 1 and 2 passed the DuPont impact test (1/3 ″ · 1 kg · 50 cm) and was immersed in tap water and 4% saline solution for 1 month without any abnormality. 5%
No problem after soaking in hydrochloric acid for 7 days, no problem after soaking in rust preventive oil and gasoline for 1 month each, and taper type
The amount of wear in the wear test of CS-17 (1 kg, 1000 times) was 8 mg, and it was durable in all of impact resistance, water resistance, oil resistance, and wear resistance.

Soundproofing Test A soundproofing test was performed to confirm whether the soundproofing performance of the grating according to each example of the present invention was significantly improved as compared with the unpainted grating (comparative example).

Therefore, in a reverberation room (temperature 14.5 ° C, humidity 62%) of an irregular pentagonal flat wall (300 mm thick reinforced concrete construction), each grating 1 was first hung as shown in Fig. 3, and steel with a diameter of 50 mm was placed in the center. The impact sound generated when the ball 10 was hit was observed.

Next, as shown in FIG. 4, each grating 1 is placed on the concrete groove 5 in the reverberation room, and 200 mm
The impact sound was observed when a steel ball 10 with a diameter of 50 mm was dropped from the height to the center of the grating.

Further, as shown in FIG. 5, a steel ball 10 having a diameter of 50 mm is placed in one corner of each grating 1 in the same reverberation room, the grating is floated obliquely, and when the steel ball 10 is quickly removed, the grating falls and the concrete I heard the impact sound that hits the table 11.

A digital frequency analyzer (BK
・ Type2131) measurement, in order
The results shown in the sound characteristic curves of FIGS.

As shown in the test results, the impact sound of the unpainted grating (comparative example) produces a metallic sound that is offensive to the ears. On the other hand, in each grating according to Examples 1 and 2 of the present invention, a soft impact sound was generated. In the frequency range of several thousand Hz, which is sensitive to human ears, the improvement of each grating of Examples 1 and 2 was found to be 10 to 30 decibels lower than that of the comparative example.

Anti-slip test Each of the gratings of Examples 1 and 2 and Comparative Example was subjected to an anti-slip test under the same conditions described below, and the results shown in Table 1 below were obtained. This data value is the friction coefficient, and point A is each grating 1 as shown in FIG.
The flat upper surface of the side frame 2 and the point B in FIG. 2 indicate the coefficient of friction in the arrow direction with respect to the flat upper surface of the flat bar 3. Further, the dry state means that the test portion for grating is in a dry state, and the wet state means that the test portion for grating is wet and wet.

It is said that a sliding friction coefficient of 0.5 or more is desirable to prevent slippage of the rider. However, as is clear from Table 1 above, in the dry state, the gratings according to Examples 1 and 2 of the present invention did not differ from the unpainted grating of the comparative example, and both values were considered to be safe. . In particular, when wetted with water, the friction coefficient was extremely reduced in the comparative example, whereas the friction coefficient of Examples 1 and 2 was extremely slightly decreased, and the anti-slip performance was 12 even in the wet condition in the rain. It turned out that it was secured in minutes.

In addition, regarding the test grating obtained in the same manner as in Example 1 except that the mixing amount of the inorganic aggregate in Example 1 was changed to 30% by weight, 55% by weight and 80% by weight, similarly, at the point B When a slip resistance test was conducted, the results shown in Table 2 below were obtained. Also, the test grating obtained in the same manner as in Example 1 except that the inorganic aggregate of Example 1 was replaced with urethane foam chips and the mixing amount was changed to 10% by weight and 20% by weight, respectively. When a slip resistance test was performed at point B, the results shown in Table 3 below were obtained. From these test results as well, it was found that the fluidity of the adjusting coating material and the uniform unevenness on the coating film surface were ensured and that the coating material had good slip resistance.

Conditions for Anti-Slip Test In this anti-slip test, as shown in FIG. 9, a swing motor 12, a measuring carriage 13, a measuring wheel 14, a measuring motor 15, a moving wheel are used.
16, load cell 17, recorder 18, measuring circuit 19, self-propelled motor
A slip tester composed of 20 and a driving wheel 21 is used. When the measuring wheel 14 rotated by the motor 15 contacts the grating 1, the torque T (kg
.Cm) was divided by the torque W.times.r of the vertical load W (kg) applied to the measuring wheel 14 (kg.cm.r is the radius of the wheel) to obtain the friction coefficient f = T / W.times.r.

The test data is recorded at room temperature 22.5 ° C. after 20 seconds from the start of the test, and the test in the wet state of the grating surface starts the test in the dry state of the grating surface. The contacting grating surface was sufficiently wet with water, and the sliding resistance in the wet state was measured for 30 seconds.

[Brief description of drawings]

FIG. 1 is a sectional view of the main part of the grating including the coating film,
FIG. 1 is a perspective view illustrating a laid state of grating, which is an object of the present invention. FIG. 3, FIG. 4 and FIG. 5 are schematic explanatory views showing soundproof test conditions. FIG. 6, FIG. 7 and FIG. 8 are characteristic curve diagrams of generated sound showing the results of three types of soundproofing tests in order. FIG. 9 is a schematic explanatory view showing a slip tester. 1 ... Grating, 2 ... Side frame, 3 ... Flat bar, 4 ... Twist bar, 6 ... Coating film, 7 ... Aggregate.

Claims (3)

[Claims] 1. A coating material containing 20 to 70% by weight of a synthetic rubber varnish and 5 to 80% by weight of an aggregate having an average particle size of 0.02 to 3.0 mm.
A metal grating whose coating material contains the entire outer surface. 2. A synthetic rubber-based varnish containing 50 to 150 parts by weight of a phenol resin in an amount of 20 to 70% by weight, and an aggregate having an average particle size of 0.02 to 3.0 mm in an amount of 5 parts by weight based on 100 parts by weight of nitrile rubber. Metallic coating with coating material containing ~ 80% by weight on all outer surfaces. 3. A synthetic rubber varnish in the coating material is 20 to 70% by weight, and an aggregate having an average particle size of 0.02 to 3.0 mm is 5 to 80% by weight.
The coating material contained in the range of 1 is adjusted, and the coating is formed by immersing the coating in the coating material bath to form a coating film on the entire outer surface.