JPS5844321Y2 - steel tape measure - Google Patents

Description

[Detailed description of the invention] The present invention relates to a steel tape measure that has clear and easy to read scales without the need for primer treatment when painting and marking the surface of the steel strip. In order to obtain a steel tape measure that does not peel off, a thermosetting resin coating is baked onto the surface of a tape measure steel strip, which has scales, numbers, etc. printed on the surface of the coating, and also has scales and numbers printed on the surface of the copper strip. A powder coated film of polyamide resin with a smooth surface and a transparent surface fixed in an amorphous state with a substantially uniform thickness is pressed onto the copper body, and the copper body is covered with the polyamide resin.

Steel tape measures must have clear and easy-to-read scales, and be able to withstand long-term use without easily peeling off. However, conventional steel tape measures meet all of the above requirements, as shown below. None of them were satisfactory, and eventually the lack of one of the necessary conditions would reduce the product's value.

For example, when the scale of a tape measure is coated with acrylic resin, the scale is clear and easy to read, but the coating film cannot be formed sufficiently thick or The disadvantage of relatively easy cracking and peeling was unavoidable, and if the surface of a hardened steel body for a tape measure was coated in advance with polyamide resin, then scales, numbers, etc. were printed on the surface. It was easy for the scale to break or disappear.

Furthermore, if the scale surface of the tape measure is coated with extrusion-molded polyamide resin, the scale will not peel off easily, but due to extrusion molding, wrinkles will form on the surface of the tape measure, making the scale unclear and difficult to read. occured.

In addition, conventionally, in order to fuse polyamide onto acrylic paint, it was necessary to prepare a resin that has good compatibility with the acrylic paint and apply it onto the acrylic paint, and Primer treatment was also required when electrocoating.

In other words, since primer treatment uses a brown epoxy resin, electrostatic A problem arises in that it is not possible to perform a primer treatment after painting, and this has hitherto been one of the bottlenecks in manufacturing.

The present invention relates to a steel tape measure developed in view of the above circumstances, and one embodiment of the present invention will be described below with reference to the drawings.

After degreasing and cleaning the baked steel strip 1, which is the material of the steel tape measure, a thermosetting resin paint, such as a white or yellow paint made of thermosetting acrylic acid resin or melamine resin, is applied and baked to form a base coating film 2. Form.

Next, the scale 3, numbers, symbols, etc. are printed on the surface of the base coating film 20 using printing ink, and this is baked, and then a powder of transparent thermoplastic resin, such as polyamide 11 resin, is coated with an electrostatic coating machine. A layer thickness of 50 to 200 μm is applied and the powder is melted using a high-frequency induction heater.

After melting, the polyamide 1 is introduced into a water tank in the molten state.
1 Rapidly cooling within 2 to 3 seconds from a temperature slightly higher than the resin's melting temperature of 186°C to room temperature, preventing crystallization inside the resin that occurs during slow cooling, and fixing it in an amorphous state. to improve adhesion with the base coating film 2.

Further, during rapid cooling, the polyamide resin is rolled by passing between a pair of upper and lower rotating rolls for a very short time (0.5 to 1.5 seconds) before it is sufficiently cooled and solidified.

In addition to cooling the powder coating film melted in the water tank as described above, it is also possible to cool the powder coat with air as appropriate and then provide a cooling means on the roll to perform rapid cooling and roll peeling at the same time.

By doing this, not only can the adhesion of the polyamide 11 resin to the base coating film 2 be further improved, but also the molten polyamide resin placed on the steel strip 1 is caused to adhere to the corners of the copper strip due to surface tension. By pressing the adhered parts to form a curved surface, both the upper and lower surfaces are smoothed, and the coatings 4' and 4' on both edges of the tape measure are thickened and adhered uniformly to the surface of the copper strip. be able to.

Therefore, according to the present invention, it is possible to obtain a tape measure having a thick coating 4' that is durable even when the edges are rubbed against a concrete surface or the like.

As described above, the tape measure of the present invention has scales 3, numbers, etc. printed on the surface of the hardened steel strip 1 for measuring tapes, which is coated with a thermosetting resin coating 2 suitable for coloring the tape measure. Then, on the entire circumferential surface of the hardened steel strip 1, a powder coated film 4°4' of polyamide resin with a smooth and transparent surface fixed in an amorphous state with a substantially uniform thickness is pressed, and the polyamide resin is Because it is covered with a copper band, the surface of the tape measure is uniformly protected by the action of these coatings 4 and 4' with a strong transparent material with good adhesion, and the scales etc. are not peeled off or worn out. There is almost no falling off, and the scale etc. are clear and extremely easy to read.It has functions and effects that cannot be achieved with a traditional tape measure, and there is no need for primer treatment as in the past.

That is, in the tape measure of the present invention, the powder coating film, which is fixed in an amorphous state of electrostatically coated polyamide resin powder, is applied onto a thermosetting resin paint such as a thermosetting acrylic acid resin paint. Because it is crimped, primer treatment after electrostatic painting is not necessary in any case, and the problem that has hitherto been a bottleneck in manufacturing can be solved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is an enlarged longitudinal sectional side view of a tape measure, FIG. 2 is an enlarged lateral sectional side view of a tape measure,
FIG. 3 is an enlarged cross-sectional side view of the tape measure when rolled during rapid cooling. In the drawing, code 1... Hardened steel strip for tape measure, 2...
...Base coating, 3...Scale, 4.4'...
...Powder coating transparent film.

Claims (1)

[Scope of utility model registration request] A thermosetting resin coating suitable for coloring a tape measure is baked onto the surface of a steel strip for measuring tapes, and scales, numbers, etc. are printed on the surface of the steel strip. A steel tape measure covered with a smooth, transparent polyamide resin powder coating that is fixed in a crystalline state.