JPH048536A - Synthetic resin tube and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a synthetic resin tube which can be easily introduced into an object and is highly resistant against chemicals by laminating the synthetic resin-coated film with a single layer or two layers or more and forming fine protrusions on the outermost layer surface. CONSTITUTION:A synthetic resin tube 1 consists of an inner layer 2 and an outer layer 3, on the external surface of which numerous fine protrusions 4... with a height of 0.01mum to 20mum are formed. The inner layer 2 and the outer layer 3 are made of synthetic resin such as polyimide, polyamideimide or polyesterimide. The inner layer 2 and the outer layer 3 of the tube 1 can be made of one kind of synthetic resin or any other kinds of choice, for example, polyimide for the inner layer 2 and polyamideimide for the outer layer 3. Thus the tube which is highly heat-resistant and also highly abrasion-resistant can be obtained. As fine protrusions are formed on the outer layer 3 surface, the tube 1 can be smoothly introduced into an object, for example, another synthetic resin tube. In addition, and type of tube having mechanical, thermal or electric properties can be obtained freely at any time by selecting synthetic resin-coated films.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a relatively small diameter synthetic resin tube used for various purposes such as medical equipment, analytical equipment, and electrical equipment, and a synthetic resin tube made of this synthetic resin. The present invention relates to a method of manufacturing a tube.

[Conventional technology]

Conventionally, a method for manufacturing this type of synthetic resin tube is disclosed in Japanese Patent Publication No. 56-44809.

The method for manufacturing this synthetic resin tube is to form a heat-adhesive resin film on a metal linear body, apply a heat-resistant resin paint on top of this, and then bake it to form a film. The resin film is stretched to at least the yield point of the metal linear body or higher to cause the resin film to lose its adhesion to the linear body, and then the metal linear body is pulled out.

[Problem to be solved by the invention]

However, this manufacturing method has the disadvantage that it is difficult to draw out the metal wire smoothly when the metal wire is combined with a resin film that has good adhesion.
Furthermore, even if the tube can be pulled out, distortion remains in the synthetic resin tube, which is disadvantageous in that it must be heated to eliminate the distortion.

For this reason, in the above-mentioned prior invention, a mold release agent such as noricorn oil is applied in advance to the surface of the metal linear body.

However, with a metal linear body coated with a mold release agent, it is difficult to apply the paint evenly when applying the synthetic resin paint in the next process. A problem arises in which the tube cannot be obtained.

Moreover, the synthetic resin tube obtained by such a manufacturing method has a smooth outer surface. Therefore, when inserting this tube into an object or a hole, if the inner surface of the object is smooth, the surfaces of the two stick to each other, and the tube cannot be inserted smoothly.

Furthermore, in this method of manufacturing synthetic resin tubes using repeated coating and baking methods, the outermost layer of the coating film is usually only subjected to one heat cycle, and the degree of hardening is lower than that of the inner coating film, resulting in its hardening. As a result, the chemical resistance and solvent resistance were poor, and there were disadvantages in that the outermost layer or a layer close to it would dissolve or swell.

The present invention was made to solve the above problems, and an object of the present invention is to provide a synthetic resin tube that can be easily inserted into an object and has excellent chemical resistance.

[Means to solve the problem]

In this invention, a paint made of silicone resin and inorganic powder is applied onto a metal linear body and baked to form a primary coating, and then one or more synthetic resin coatings are applied once on the primary coating. After applying and baking the above to form a secondary coating film to obtain a coated linear body, applying external stress to this coated linear body causes the resin coating to lose its adhesion to the linear body. Then, the resin coating is turned over from one end of the metal linear body, and the resin coating is applied from the metal linear body so that the turned resin coating is covered over the uncoated linear body. By peeling off, a synthetic resin tube having fine protrusions on the outermost layer surface is obtained, thereby solving the above problem.

The present invention will be explained in detail below.

FIG. 1 shows an example of a synthetic resin tube according to the present invention, and reference numeral 1 in the figure indicates the synthetic resin tube (hereinafter simply abbreviated as tube) according to the present invention. This tube 1 has a two-layer structure consisting of an inner layer 2 and an outer layer 3.

The inner layer 2 soil is provided with an outer layer 3, and the outer layer 3
Countless fine protrusions 4 with a protrusion height of 0.001 μm to 20 μm are formed on the outer surface.

These inner layer 2 and outer layer 3 are made of synthetic resin such as polyimide, polyamideimide, polyesterimide, polyesteramideimide, polyester, polyurethane, polyhinyl formal, polyvinyl butyral, polyethylene terephthalate, phenokino, polysulfone, and the like.

In addition, although the tube l in this example has a double layer structure consisting of an inner layer 2 and an outer layer 3, it may naturally have a single layer structure made of one type of synthetic resin, or it may have a double layer structure made of one type of synthetic resin. For example, by constructing an inner layer 2 made of polyimide and an outer layer 3 made of polyamideimide, a tube with excellent heat resistance and abrasion resistance can be obtained. The type and number of layers can be changed as appropriate.

Furthermore, it is also possible to color each layer depending on the intended use of the tube 1. At this time, a coloring agent such as a dye or a pigment can be used for coloring.

These coloring agents may be dispersed throughout the tube 1, but the coloring agents are dispersed only in a portion of the tube, i.e., ■ the outermost layer of the tube, ■ the middle layer of the tube, and ■ the innermost layer of the tube. It may be colored without adding a coloring agent.

Next, a method for manufacturing such a tube I will be explained.

First, a metal wire body made of metal such as copper, aluminum, gold, or silver is prepared. The metal wire body is not limited to a circular cross-sectional shape, but may have a square, rectangular, hexagonal, triangular, or elliptical cross-sectional shape.

Next, a paint made of silicone resin and inorganic powder is applied to the surface of this metal linear body and baked using an enamel baking oven or the like to form a primary coating film. The nolicone resin here is not particularly limited, but methylsilicone, phenylmethylsilicone, phenylnolicone, etc. can be used, and those with an elongation rate after baking of at least 30% are preferred. In addition, as inorganic powders, calcium carbonate, silica, calc, clay, titanium oxide, gypsum, mica, iron oxide, diatomaceous earth, volcanic ash, etc. are used, and the particle size is in the range of 0.01 to 20 μm. To be elected. Further, the ratio of silicone resin and inorganic powder in the paint is about 10 to 1000 parts by weight of inorganic powder per 100 parts by weight of noricorn resin. moreover,
This paint contains aromatic hydrocarbons such as toluene, kiln, and ethylbenzene, as well as polyhydric alcohol derivatives such as diethylene glycol monoethyl ether,
A polar solvent such as benol alcohol or N-methyl-pyrrolidone may be added. This polar solvent is blended so that it can be uniformly dispersed in the paint without causing agglomeration, precipitation, or gelation due to inorganic powder or moisture absorption. The solid content of the silicone resin and inorganic powder in this paint is approximately 30 to 80%.

This paint is applied to the metal linear body using an ordinary enamel coating die or the like. The thickness of the primary coating film after baking is preferably about 10 to 30 μm. and,
Therefore, on the outer surface of this primary coating film, fine irregularities are formed due to the presence of the inorganic powder and the polar solvent, and the surface is made non-adhesive or difficult to adhere to due to the noricorn resin.

Next, a synthetic resin paint is applied onto this primary coating and baked to form a secondary coating. The synthetic resin paint used here is one made of synthetic resins such as polyimide, polyamideimide, polyesterimide, polyesteramideimide, polyester, polyurethane, polyvinyl formal, polyvinyl butyral, polyethylene terephthalate, phenokino, polysulfone, and the like. The formation of this secondary coating film is performed by repeatedly applying and baking the synthetic resin paint one or more times to obtain the desired thickness. A resin paint can also be used. The synthetic resin paint is similarly applied using an enamel coating die, and an enamel baking furnace is used for baking.

In this way, a coated linear body having a resin coating consisting of a primary coating film and a secondary coating film is obtained.

Next, external stress is applied to this coated linear body to reduce the adhesion between the primary coating film and the secondary coating film. As means for applying external stress, means such as bending the coated linear body or rubbing the end with sandpaper can be used.
Although not particularly limited, it is convenient to use a straightener or the like that is used to correct small bends in conductive wires.

Due to the application of this external stress, since the surface of the primary coating film is non-adhesive or has poor adhesion, the adhesion between the primary coating film and the secondary coating film is considerably reduced.

Next, cut the secondary coating film of the coated linear body whose adhesion between the primary coating film and the secondary coating film has been reduced at predetermined lengths in the circumferential direction, and apply the secondary coating film. After cutting the metal wire, as shown in FIG. The secondary coating film 7 is peeled off in a tube shape so as to cover it on top of 5.

The reason why the secondary coating film 7 can be easily peeled off from the primary coating film 6 to form the tube l in this way is that the secondary coating film 7 and the primary coating film 6 are separated in the previous step. This is because the adhesion between them is reduced.

According to such a manufacturing method, only elongation acts on the resulting tube, that is, the secondary coating film, so that there is no distortion in the tube. Furthermore, the surface of the secondary coating film on which the fine irregularities on the surface of the primary coating film are transferred and minute protrusions are formed is turned over to become the outermost layer, resulting in a tube having minute protrusions on the outer surface. Furthermore, since a primary coating film is formed between the metal linear body and the secondary coating film that becomes the tube,
There is no possibility of metal powder adhering to the inner surface of the tube. In addition, the fine irregularities on the surface of the primary coating improve the wettability of the synthetic resin paint that will become the secondary coating, resulting in a secondary coating, ie, a tube, with a uniform thickness.

Furthermore, a primary coating film is attached to the metal linear body,
Since it is not given much stretch, it is possible to reuse it repeatedly as it is. In addition, when a tube is formed, the coating film closest to the metal linear object becomes the outer layer of the tube, and the coating film that has been baked the most times and has a high degree of hardening becomes the outermost layer, so the tube should have high chemical resistance. I can do it.

Furthermore, before the coating film is peeled off from the metal linear body 5, the outer surface of the outermost coating film is rubbed with sandpaper to form fine protrusions 4 on the outer surface. By turning the coating over and peeling it off, it is possible to obtain a tube 1 having minute protrusions 4 on the surface of not only the outermost layer but also the innermost layer, as shown in FIG. With such a tube 1, not only can the tube 1 be easily inserted into an object, but also an object can be easily inserted into the tube 1.

〔Effect of the invention〕

As explained above, the synthetic resin tube of the present invention has a laminated structure in which one or more layers of synthetic resin coating are laminated, and fine protrusions are formed on the outermost layer surface. When inserting a synthetic resin tube into an object, for example, into another synthetic resin tube, it can be inserted extremely smoothly. Further, by selecting a synthetic resin coating film, one having a wide range of properties (mechanical properties, thermal properties, electrical properties, etc.) can be obtained as appropriate.

In addition, the method for manufacturing a synthetic resin tube of the present invention involves coating a metal linear body with a paint made of silicone resin and inorganic powder and baking it to form a primary coating film. Apply one or more types of synthetic resin paint one or more times,
After baking and forming a secondary coating film to obtain a coated linear body,
By applying external stress to this coated wire body, the adhesion of the resin coating film to the wire body is lost, and then this resin coating film is turned over from one end, and the uncoated wire is removed. Since it is obtained by peeling off the resin coating film from the metal linear body by covering the resin coating film upside down on the shaped body, the thickness is uniform and there is no residual distortion.
It is possible to obtain a highly chemical-resistant synthetic resin tube that is free from adhesion of foreign matter such as metal powder and has fine protrusions formed on its outer surface.

[Brief explanation of drawings]

1 and 3 are both schematic cross-sectional views showing an example of the synthetic resin tube of the present invention, and FIG. 2 is a schematic view showing one step of the method for manufacturing the synthetic resin tube of the present invention. !・Synthetic resin tube, 2...inner layer, 3...outer layer, 4
・Minute protrusions, 5. Metal linear body, 6.. Primary coating film, 7-.
・Secondary coating film. Figure 3

Claims (2)

[Claims] (1) A synthetic resin tube having a laminated structure in which one or more synthetic resin coating layers are laminated, and having fine protrusions formed on the outermost layer surface. (2) After coating a metal linear body with a paint made of silicone resin and inorganic powder and baking it to form a primary coating film, one or more synthetic resin paints are applied one or more times on this primary coating film. After coating and baking to form a secondary coating film to obtain a coated linear body, external stress is applied to the coated linear body to cause the resin coating to lose its adhesion to the linear body. Then, the resin coating is turned over from one end, and the resin coating is peeled off from the metal linear body by covering the turned over resin coating on the linear body that is still covered with the coating. A method for manufacturing synthetic resin tubes characterized by: