JPH067946B2 - Spray elastomer coating construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present application relates to a coating method using a polyurethane elastomer, and in particular, the elastomer can be easily adapted to changes in a narrow place or a small-scale coating object due to complicated conditions. It is expected that the quality of raw materials will be kept as much as possible without deterioration, simple and economical equipment without ideal heavy equipment and obtained under ideal conditions, which is not inferior to the results of the actual laboratory. Related to possible construction methods.

<Prior Art> Conventionally, a raw material liquid for an elastomer is supplied by a drum can. Since the object to be coated is not generally uniform, and the space is small and the target for small-scale coating is uncertain, in order to supply the raw materials to the spray gun for spraying (spraying machine), a drum pump is used to suck the material in an oven. Was used by inserting. Therefore, it was not possible to prevent deterioration due to moisture absorption of the raw material due to contact with air. If the coating elastomer needs to be colored, take the solution B into another container, add the coloring material, stir and mix, and then transfer it to the raw material liquid drum and circulate the solution with other additives while heating. It was stirring.
Thus, the adjusted liquids B and A were heated to a predetermined temperature and sent to a spray gun to be reacted while being sprayed for coating. According to such a conventional technique, CO ₁ generated by the reaction of the raw material isocyanate by the humidity of the sucked air is mixed into the elastomer to form bubbles, and the bubbles are entrained during the mixing of the raw materials to obtain the mechanical strength of the product. Brought about a decline. If the isocyanate is decomposed, the molar ratio between the raw materials is disturbed, which causes a deterioration in quality. In addition, if a low-speed agitation that does not involve air bubbles is performed as in conventional colorant mixing, part of the colorant will settle,
There was a problem that color unevenness occurred in the product.

<Problems to be Solved by the Invention> a) Deterioration of liquid A due to moisture contained in sucked air, moisture in air contacted during handling, and foaming due to CO ₂ generated thereby, change in molar ratio Quality degradation due to.

B) Incorporation of air bubbles in liquids A and B.

C) Non-uniformity of the elastomer coating surface and / or occurrence of color unevenness.

D) A container of highly toxic isocyanate and cleaning treatment after use.

(E) Ideally, heavy equipment can be easily considered for large-scale painting objects in a wide area, but it is a problem to achieve the purpose with light equipment for small-scale painting work in a small area.

<Means for Solving the Problem> If heavy equipment is allowed in the invention like this application, it is possible by a combination of conventional techniques based on the knowledge in the laboratory. This kind of heavy equipment is not possible. The present invention has been achieved as a result of intensive research so that the above problems can be satisfied with light equipment and at low cost.

A) The raw material liquids A and B are used as they are for the transportation container drums, and no special container is provided for mixing the coloring material. A drum can for transporting liquid B is used, and the stirrer can be detachably and airtightly attached to the hole in the lid, and the wings of the stirrer can be shrunk in the axial direction of the rotating shaft depending on the size of the hole. Size so that it can pass through. By rotating the structure of the stirrer's wings, the resistance of the liquid causes it to open up to a position perpendicular to the axis of rotation, or it opens manually. Also, the position of the feather in the liquid should be changeable. A constant speed motor is used to keep the stirring constant regardless of the change in the amount of liquid to prevent bubbles from being trapped.

B) CO ₂ due to decomposition caused during the reaction by mixing with the liquid A by the water contained in the air sucked into the drum can after the raw material liquid in the drum can is sent to the spraying machine by the drum pump
To prevent the occurrence of air, replace it with dry air or nitrogen.

C) Even if the liquid level of liquid B drops due to use, keep stirring constant so that air bubbles are not entrained.

D) Adjustment of other temperatures is performed by known means.

E) Regarding the raw materials used and the production conditions, the present invention is the addition of the invention by the method for producing a polyurethane-polyurea elastomer disclosed in Japanese Patent Application Laid-Open No. 61-247721 by the same applicant as this application. It is a target.

<Operation> Even if the liquid surface of the drum can changes, the raw material transport drum can be stirred so as to maintain a constant speed rotation and prevent air bubbles from being entrapped, and air that comes into contact with the liquid can be provided with a drying means. Equipment keeps the quality of raw materials.

Example The present application has carried out a method for producing a spray elastomer completed under conditions where ideal conditions can be easily achieved in a laboratory, with the lightest possible equipment, and has the same effect as obtained in the laboratory. This will be shown by Examples and Comparative Examples. The raw materials, their compounding ratios, and temperature conditions were the same.

Comparative Example (Prior Art) A drum can of a raw material liquid transport container was used, and an additive mixture was taken in a separate container. The additive was left open, mixed with the additive, transferred to a drum can, and stirred by circulating the liquid. No consideration was given to the drying of the air in contact with the liquid.

<Example> The process for producing an elastomer and the coating method required for carrying out the spray elastomer coating method of the present invention will be described with reference to FIG.

In the figure, reference numeral (hereinafter omitted) 1 is a drum for transporting the liquid B. In order to insert the stirrer 5 into the liquid through the hole of this lid, the wings are shrunk and the liquid is passed through. Inside, the structure is such that the stirrer blade opens until it becomes perpendicular to the shaft due to the resistance of the liquid due to the rotation of the shaft of the stirrer. The structure may be manually opened. The stirring is performed by the constant speed motor 4. 2 is a drum can container for the liquid A, which is equipped with dryers 13 and 23 like the drum can for the liquid B, and dries the air that enters the drum can as the liquid is used. Prevent alteration. Both liquids are heated by the pumps 12 and 22 by the heater 1
It circulates through 1, 21. Both liquids that have been heated to an appropriate temperature are sent to the coating construction site by a flexible pipe that can withstand the liquids, and both liquids react with a spray gun to become elastomers, which are discharged in the spraying direction 6 and the surface of the object to be coated is coated. The raw material liquids left by the spray gun are returned by the liquid return pipes. The solution is to solve the problem by making the liquid transportation pipe flexible and making it long even if the painting site is a small place or even a small one.

In the invention of the present application, a drum can for liquid transportation is used, and a specific agitator 5, dryers 13 and 23, and a liquid circulation pump 1 are used.
2, 22 were attached to the holes of the lids of the respective drums in an airtight manner and detachably.

Next, Table 1 shows the comparison of the quality of the products of the laboratory, the present invention, and the conventional methods 1, 2, and 3 as follows.

EFFECTS OF THE INVENTION By the light equipment according to the present invention, the same effects as those of the laboratory having the ideal equipment were obtained. The chance of contact with the highly toxic liquid A was reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating the process of manufacturing the spray elastomer of the present invention and the method of coating. 1 ... B liquid can, 2 ... A liquid can, 11,21
... Heater, 12, 22 ... Pump, 3 ... Spray gun, 4 ... Motor, 5 ... Stirring machine, 6 ... Spraying direction, 13, 23 ... Dryer, 14, 24 ... Liquid circulation pump , 15, 25 ... Liquid sending pipe, 16, 26 ... Liquid returning pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Open 61-95487 (JP, U) Open 57-111371 (JP, U) Open 53-77408 (JP, U)

Claims (4)

[Claims] 1. An isocyanate (MDI) A liquid, a polyether B liquid, and an additive consisting of a catalyst, a pigment, and plasticity.
When C is applied to the surface of an object to be coated at the construction site, the raw material is treated as it is in the drum of the transport container, so that even if the liquid level in the transport container of liquid B changes. An agitator that keeps rotating at a constant speed, an air-moisture preventive device is installed at the air inlets of both liquid containers to maintain the uniformity of the liquid, and to contact it during the handling of the humidity and / or liquid of the inhaled air due to the liquid loss associated with the use of the liquid A spray elastomer coating method characterized by reacting both liquids while preventing deterioration and air bubbles from entering due to air humidity. 2. A stirring method for preventing the inclusion of air bubbles and for maintaining the reaction solution uniformly, in the solution B, the resistance of the solution responds to the rotation in the solution B to open the stirring blades to stir the solution, and the hole in the lid of the drum can. The construction method according to item 1, wherein when it is put in and taken out, it can be freely withdrawn and put in and cannot be opened beyond a right angle with respect to the rotating shaft. 3. The construction method according to claim 1, wherein the stirring method for maintaining constant speed rotation despite the change of the liquid level is by a constant speed motor. 4. The construction method according to claim 1, wherein the method for preventing moisture from the liquid is a method using a dry gas that has passed through a desiccant.