JP2570020B2 - Mixing method of polyurethane forming components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTIONFor polyurethane production
Polyol component and isocyanate component as main components
And coloring components, catalyst components, etc.Is dispersed in the polyol component
BecomeIn a method of mixing with at least one secondary component
In particular, the present invention relates to improvements in the method of controlling the temperature of secondary components.
It is.

[0002]

2. Description of the Related Art Conventionally, it is a main component for producing polyurethane.
In mixing the polyol component and the isocyanate component , these main components are supplied from the respective storage containers to the mixing head through a pump and a supply path of a circulation path, and discharged from the nozzle of the mixing head into the mixing chamber to collide with each other. By doing that. When the mixing is stopped, each main component is circulated in a loop of a storage container → a pump → a supply path of a circulation path → a mixing head → a circulation path of a circulation path → a storage container. By the way, when the temperature of these main components changes due to the change of the outside air temperature, the viscosity also changes, while the discharge pressure and the opening of the orifice of the nozzle are constant, so that the discharge amount to the mixing chamber changes. Therefore,
Conventionally, a heating device is provided in the storage container of each main component, and the main component stored in the storage container is heated to maintain the temperature at the time of discharging to the mixing chamber substantially constant. This is because each main component circulates in the loop, so that a temperature change in the course of passing through the circulation path is small.

[0003] In addition, it is often the case that at least one type of secondary component such as a coloring component is added to the at least two types of main components and mixed. The mixing of the secondary components is performed by supplying the mixture from the storage container to the mixing head through a pump and a one-way path, and simultaneously discharging the mixture from the sub-discharge holes of the mixing head into the mixing chamber of the main component. The one-way path is used so that the secondary component can be easily exchanged with another secondary component according to color switching or the like. In general, this secondary component has a very large temperature dependence of viscosity, and particularly when the temperature is lowered by the outside air temperature, the viscosity sharply increases, while the discharge pressure and the orifice area of the sub-discharge hole are constant. The amount of discharge into the mixing chamber decreases rapidly. For this reason, the mixing ratio goes out of order, causing problems such as variations in color density. Therefore, conventionally, a heating device is provided in a storage container for a secondary component as in the case of the main component, and the secondary component stored in the storage container is heated.

[0004]

However, only by heating the secondary components stored in the storage container, the secondary components may be heated by the outside air while passing through a one-way path having a length of 2 to 10 m. Because of the cooling, the temperature at the time of discharging to the mixing chamber becomes lower than the desired temperature. For this reason, it is difficult to keep the viscosity of the secondary component at the best, and the ejection amount is slightly changed to deviate from the desired mixing ratio, and it is not possible to completely eliminate the problems such as the variation in the color density. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and maintain the ejection amount substantially constant while maintaining the best viscosity of the secondary component, thereby maintaining a desired mixing ratio, such as a variation in color density. It is an object of the present invention to provide a method for mixing components for producing polyurethane, which can completely solve the problem of the above.

[0005]

In order to achieve the above-mentioned object, the present invention provides a method for preparing a polyol component as a main component and isolating the polyol component.
The cyanate component is supplied from each storage container to the mixing chamber of the mixing head through the supply path of the circulation path, and the coloring component, the catalyst component, etc. are dispersed in the polyol component.
At least one additional component is supplied from the storage container to the mixing chamber through a one-way path that does not form a circulation loop, and the polyol component and the isocyanate are mixed in the mixing chamber.
Polyurethane raw which mixes nate component and secondary component
In the method for mixing the components, the means for heating the secondary component passing through the one-way path in the one-way path to maintain the temperature of the secondary component discharged to the mixing chamber substantially constant. Has been adopted.

Here, a polyol component is used as a secondary component .
Examples of the component to be dispersed in the component include a coloring component and a catalyst component. In order to heat the secondary component passing through the one-way path, a method of indirectly heating the internal secondary component from the outer periphery of the one-way path, a method of directly heating the internal secondary component, There is. Examples of the heating means include an electric heater such as a heating wire heater and a ceramic heater, and a tube for circulating hot water. These heating means may be provided on the entire length of the one-way path, or may be provided on a part thereof. When it is provided in a part, the tip of the one-way path is preferable. In addition, it is only necessary to heat the secondary components passing through the one-way path, but it is also possible to add heating to the secondary components stored in the storage container. The heating temperature is determined according to the type of the secondary component (component, temperature dependency of viscosity, etc.) and the outside air temperature, and is 35 to 40 ° C. which is around the maximum temperature of the outside air temperature.
Is common.

[0007]

According to the present invention, by heating the secondary component passing through the one-way path, the secondary component is prevented from being cooled by the outside air temperature on the way to the one-way path, or is cooled. Even so, since the temperature is increased by that amount, the temperature of the secondary component discharged into the mixing chamber is maintained substantially constant. Therefore, the best viscosity of the secondary component is maintained, and the discharge amount is maintained substantially constant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a method for mixing a synthetic resin component for producing polyurethane will be described with reference to the drawings. As shown in FIG. 1, in a mixing head 1 used in this method, a head body 4 is attached to a cylinder 2 via a body flange 3, and a through hole 5 is formed at the center of each of the body flange 3 and the head body 4. Is formed. A spool 6 is slidably inserted into the through hole 5, and a proximal end thereof is connected to a piston 7 of the cylinder 2. The front half of the spool 6 has a pair of long grooves 8.
Each of the grooves 8 is fitted with a tip of a detent pin (not shown) screwed to the head body 4. As the piston 7 reciprocates, the spool 6 is slid between the forward position shown in FIG. 1 and the retracted position shown in FIG. You.

A pair of cylindrical nozzles 10 are provided opposite to each other inside the head body 4 at a position where the spool 6 passes, and each of the nozzles 10 has a tapered orifice communicating with the mixing chamber 9. Have been. A nozzle holder 11 for holding and holding each nozzle 10 is mounted on the outer surface of the head body 4, and a supply hole 12 communicating with the nozzle 10 is formed inside the nozzle holder 11. A needle 13 is inserted into the nozzle holder 11 and the nozzle 10, and the tip of the needle 13 adjusts the opening degree of the orifice of the nozzle 10. On the other hand, the head body 4 behind the nozzle 10
Is formed with a return hole 14, the inner end of which is connected to the long groove 8 of the spool 6.

A sub-discharge hole 15 is formed in the center of the front half of the spool 6, the front end of which is open at the front end face of the spool 6, and the rear end is open at the side wall of the spool 6. On the side wall of the body flange 3, there is formed an introduction hole 16 communicating with the rear end opening of the sub discharge hole 15 of the spool 6 only when the spool 6 is retracted.

Subsequently, in the first and second storage containers 17 disposed in the vicinity of the mixing head 1 having the above structure, a polyol component A and an isocyanate component B as first and second main components, respectively, are stored. Have been. The outlet 18 of each storage container 17 and the supply hole 12 of the mixing head 1 are connected to the supply hose 2 near the outlet 18 via a pump 23.
1, the return hole 14 of the mixing head 1 and the return port 19 of each storage container 17 are connected by a return hose 22. Therefore, the storage container 17 → the pump 23
→ supply hose 21 → mixing head 1 (supply hole 12 →
Nozzle 10 → long groove 8 → reflux hole 14) → reflux hose 22 →
A circulation path 20 composed of a loop of the storage container 17 is formed. Further, each storage container 17 is provided with a known heating device 24 for heating the stored polyol component A and isocyanate component B to maintain their temperatures substantially constant.

A coloring component C as a secondary component is stored in the third storage container 25. The coloring component C is obtained by dispersing a pigment component in a polyol component. A pump 27 is connected to an outlet 26 of the third storage container 25, and a one-way hose 28 is connected to the pump 27 as a one-way path having flexibility. A connection member 29 is provided that is detachably connected to the hole 16. By reconnecting the connecting member 29 to the connecting member of the one-way hose that passes the coloring component of another color, the color can be easily switched. The third storage container 25 is provided with a known heating device 30 that heats the stored coloring component C and maintains the temperature at a substantially constant temperature.

Further, a tape-shaped electric heater 31 is wound around the entire length of the outer peripheral surface of the one-way hose 28 in a dense or coarse spiral shape, and a heat insulating material 3 is provided on the outer peripheral surface of the electric heater 31.
2 are applied. A temperature sensor 33 for detecting the temperature of the surface of the hose is provided at the tip of the one-way hose 28. The amount of heat generated by the electric heater 31 is controlled based on the information from the temperature sensor 33, so that the mixing head is controlled. A control device 34 for maintaining the temperature of the coloring component C discharged into one mixing chamber 9 substantially constant is provided.

When the spool 6 moves forward as shown in FIG. 1, since the long groove 8 of the spool 6 is located at the orifice of the nozzle 10 and the opening of the recirculation hole 14, the polyol component A and the isocyanate component B pass through the circulation path 20. Circulate. The polyol component A and the isocyanate component B
Is heated by the heating device 24 in the storage container 17 and its temperature is maintained substantially constant. Further, since the rear end opening of the sub-discharge hole 15 of the spool 6 is separated from the introduction hole 16 and does not communicate with it, the coloring component C stops at the introduction hole 16. This coloring component C is first heated by the heating device 30 in the storage container 25, and then, the phenomenon of being cooled by the outside air temperature in the middle of the one-way hose 28 is prevented by the electric heater 31. Not only that, the temperature of the stopped distal end is also maintained substantially constant.

Next, at the time of retreat of the spool 6 shown in FIG. 2, a mixing chamber 9 is formed in the through hole 5 in front of the spool 6, and since this mixing chamber 9 is located at the opening of the orifice of the nozzle 10, The polyol component A and the isocyanate component B are respectively discharged from the orifices of the nozzle 10, collide with each other, and are mixed. Since the rear end opening of the sub-discharge hole 15 of the spool 6 coincides with and communicates with the introduction hole 16, the coloring component C is simultaneously discharged from the front end opening of the sub-discharge hole 15 toward the collision mixing section of the mixing chamber 9. And mixed together. At this time, the coloring component C discharged into the mixing chamber 9
Since the pressure is maintained substantially constant by the electric heater 31 from the start of the discharge, the best viscosity is maintained and the discharge amount is maintained substantially constant. Accordingly, a desired mixing ratio can be maintained, and problems such as variations in color density can be completely eliminated.

It should be noted that the present invention is not limited to the configuration of the above-described embodiment, but may be embodied with the following modifications without departing from the spirit of the invention. (1) Two or more one-way hoses 28 each having an electric heater 31 are connected to the connection member 29, and these are switched by a valve. (2) Fixing the heating value of the electric heater 31 to an optimum value, and omitting or simplifying the temperature sensor 33 and the control device 34. (3) The electric heater 31 is provided on substantially the entire length of the one-way hose 28, and if the heating performance is sufficient, the heating device 30 in the storage container 30 for the coloring component C can be omitted or simplified.

[0017]

EFFECT OF THE INVENTION Mixing of the polyurethane-forming components of the present invention
The method, as described above, is easy to cool secondary components on the way
Despite using a one-way road, a secondary
By heating the next component in the one-way path, mixing
Keep the temperature of the secondary components discharged into the joint room approximately constant.
Which is configured urchin, the minor component while maintaining the best viscosity can maintain its ejection amount substantially constant with by <br/> of variations in color density to maintain the desired mixing ratio This has an excellent effect that the problem can be completely solved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a state where a spool is advanced in an embodiment embodying the present invention.

FIG. 2 is a schematic explanatory view showing a state in which the spool is retracted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mixing head 9 Mixing chamber 17 First and second storage containers 20 Circulation path 21 Supply hose as supply path 25 Third storage container 28 One-way hose as one-way path 31 Electric heater 32 Heat insulator 33 Temperature sensor 34 Control Apparatus A polyol component B isocyanate component C coloring component

Claims (1)

(57) [Claims] 1. A polyol component as a main component and an isocyanate
The anate component is supplied from each storage container to the mixing chamber of the mixing head through the supply path of the circulation path, and the coloring component, the catalyst component, etc. are dispersed in the polyol component.
At least one secondary component is supplied from the storage container to the mixing chamber through a one-way path that does not form a circulation loop, and the polyol component and the isocyanate are mixed in the mixing chamber.
Polyurethane formation by mixing the heat component and secondary components
In the method of mixing the component, the temperature of the secondary component discharged into the mixing chamber is maintained substantially constant by heating the secondary component passing through the one-way path in the one-way path. Polyurethane characterized by doing
A method for mixing the components for production .