JP4294850B2 - Reaction injection molding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reaction injection molding apparatus, and more particularly to a reaction injection molding apparatus such as polyurethane foam, in which two components that react with each other are used as raw materials, injected at a high pressure, and injected into a mold while reacting.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, it has been widely practiced to form a foamed molded article such as polyurethane foam by RIM molding in which an isocyanate component and a polyol component are used as raw materials and injected into a mold while being injected and reacted at a high pressure.
[0003]
In recent years, the use of chlorofluorocarbons and alternative chlorofluorocarbons, which are responsible for the destruction of the ozone layer, has been completely abolished. Various proposals have been made to use an inert gas.
[0004]
[Problems to be solved by the invention]
However, in the examination up to now, it takes a considerable amount of time to dissolve carbon dioxide in the raw material, and even if RIM molding is performed, it is not easy to reduce the cell diameter of the foam molded body to 100 μm or less, for example. However, there is a strong demand for the development of a RIM molding apparatus that can practically form a microcellular foam molded article having a cell diameter of 100 μm or less.
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to easily and quickly form a microcellular foam molded article having a small cell diameter using an inert fluid such as carbon dioxide or nitrogen. It is an object of the present invention to provide a reaction injection molding apparatus that can be molded by the above method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a reaction injection molding apparatus, comprising: a raw material quantifying means for quantifying a raw material; an inert fluid quantifying means for quantifying an inert fluid; and the raw material quantifying means. The premixing means for continuously premixing the raw material quantified by the above and the inert fluid quantified by the inert fluid quantifying means at a mixing pressure of 10 to 30 MPa, the raw material preliminarily mixed by the premixing means and the inert In the fluid mixture, the mixture of the raw material and the inert fluid is pressurized at 5 to 30 MPa and heated at 30 to 100 ° C. to dissolve the inert fluid continuously and substantially completely in the raw material. And a mixing injection means for injecting the raw material at a high pressure and injecting it into the mold while reacting.
[0007]
According to such a configuration, the raw material is quantified by the raw material quantification means, and the inert fluid is quantified by the inert fluid quantification means, and they are continuously continuously at a constant rate at a mixing pressure of 10 to 30 MPa by the premixing means. After the preliminary mixing, the inert fluid is continuously and substantially completely dissolved in the raw material by the dissolving means. Thereafter, the raw material in which the inert fluid is dissolved is injected at a high pressure by the mixing and injecting means, and injected into the mold while reacting, whereby RIM molding is performed.
[0008]
Therefore, the inert fluid is continuously mixed and dissolved in the raw material at a constant ratio and substantially completely dissolved , and the reaction injection molding is performed in this state. It can be molded in a short time.
[0010]
Moreover, according to such a structure, the mixture of the raw material and the inert fluid premixed at a certain ratio is pressurized at 5-30 MPa and heated at 30-100 ° C. by the dissolving means. Therefore, the inert fluid is substantially completely dissolved in the raw material, and a microcellular foamed molded article having a small cell diameter can be molded well.
[0011]
The invention described in claim 2 is characterized in that, in the invention described in claim 1 , a pre-loadable mold is further provided.
[0012]
According to such a configuration, after the raw material in which the inert fluid is dissolved is injected at a high pressure and injected into the mold while being reacted, the expansion speed of the inert fluid is suppressed by the preload of the mold, Finer cells can be formed to form a microcellular foamed product having a smaller cell diameter.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram showing an embodiment of a reaction injection molding apparatus of the present invention.
[0014]
In FIG. 1, this reaction injection molding apparatus 1 is a RIM molding apparatus for molding a microcellular polyurethane foam, which is an isocyanate supply unit 2 for supplying an isocyanate component, and a polyol supply unit for supplying a polyol component. 3. A mixing head 4 and a mold 5 are provided as mixing injection means.
[0015]
The isocyanate supply unit 2 and the polyol supply unit 3 have almost the same apparatus configuration, and are raw material tanks 6 and 7, raw material quantitative supply pumps 8 and 9 as raw material quantitative means, inert fluid tanks 10 and 11, inert gas Inert fluid metering supply pumps 12 and 13 as fluid metering means, premixing units 14 and 15 as premixing means, and high-pressure heaters 16 and 17 as melting means are provided.
[0016]
The raw material tanks 6 and 7 store raw materials, and more specifically, the raw material tank 6 stores isocyanate components such as polyisocyanate compounds as raw materials. Contains a polyol component such as a polyol compound as a raw material.
[0017]
Each raw material constant supply pump 8 and 9 is connected to the downstream side of each raw material tank 6 and 7, respectively, and each raw material, that is, an isocyanate component and a polyol component is respectively supplied in a predetermined amount and a predetermined pressure to each premixing unit. 14 and 15 for transportation.
[0018]
Further, inert fluids such as carbon dioxide and nitrogen are stored in the inert fluid tanks 10 and 11, respectively, and the amounts of the inert fluids connected to the downstream sides of the inert fluid tanks 10 and 11, respectively. The supply pumps 12 and 13 are configured to transport the inert fluid in the inert fluid tanks 10 and 11 to the premixing units 14 and 15 at a predetermined amount and a predetermined pressure.
[0019]
The preliminary mixing units 14 and 15 are connected to the raw material constant supply pumps 8 and 9 and downstream of the inert fluid constant supply pumps 12 and 13, respectively. The raw material supplied from 8 and 9 and the inert fluid supplied from each inert fluid metering pump 12 and 13 are continuously premixed. More specifically, in each of the preliminary mixing units 14 and 15, the raw material supplied from the raw material constant supply pumps 8 and 9 at a predetermined pressure and the inert fluid fixed supply pumps 12 and 13 are supplied at a predetermined pressure. The inert fluid is physically collided at a predetermined ratio determined in each case and continuously premixed.
[0020]
The high-pressure heaters 16 and 17 are connected to the downstream sides of the preliminary mixing units 14 and 15, respectively. In the mixture of the raw material and the inert fluid preliminarily mixed in the mixing units 14 and 15, the raw material The inert fluid is continuously dissolved. More specifically, each of the high-pressure heaters 16 and 17 is provided with a heater around the pressure-resistant piping, and the mixture of the raw material and the inert fluid is passed through the pressure-resistant piping and pressurized as it is (holding pressure). ) While being heated with a heater as necessary, the inert fluid is continuously dissolved in the raw material.
[0021]
The mixing head 4 is connected to the high-pressure heaters 16 and 17 on the downstream side of the high-pressure heaters 16 and 17, and the raw materials in which the inert fluid is dissolved in the high-pressure heaters 16 and 17 are connected. They are mixed, injected at high pressure, and injected into the mold 5 while reacting.
[0022]
Further, a pressurizing cylinder 18 such as a nitrogen cylinder is connected to the mold 5 as a pressurizing means, and is configured so that the inside of the cavity can be preloaded before RIM molding. The mold 5 is provided with a heater (not shown) and an adjustment valve for gas venting (not shown) for releasing gas generated by foaming to the outside.
[0023]
Next, a method for molding a microcellular polyurethane foam using the reaction injection molding apparatus 1 configured as described above will be described.
[0024]
First, the process in the isocyanate supply unit 2 will be described. In the isocyanate supply unit 2, first, the isocyanate component stored in the raw material tank 6 is supplied to the premixing unit 14 by the raw material fixed supply pump 8, for example, at a pressure of 10 to 30 MPa, and at the same time, inactive. The inert fluid stored in the fluid tank 10 is supplied to the preliminary mixing unit 14 by the inert fluid metering supply pump 12 at a pressure of 10 to 30 MPa, for example. As a result, the isocyanate component and the inert fluid are supplied to the premixing unit 14 at a high pressure, so that they are satisfactorily mixed by collision. The supply amount of the raw material and the inert fluid is adjusted to be 0.05 to 20% by weight with respect to the whole raw material in the total of the supply amount of the inert fluid supplied to the polyol component described later, mixture pressure in the pre-mixing unit 14, adjusted to be 10 to 30 MPa.
[0025]
After the isocyanate component and the inert fluid thus supplied are continuously premixed in the premixing unit 14, the mixture of the isocyanate component and the inert fluid is then pressurized at 5 to 30 MPa in the high-pressure heater 16. (holding pressure), and, by heating at 30 to 100 ° C., continuously the inert fluid in the isocyanate component, substantially completely dissolved. Conditions for dissolving the inert fluid in the isocyanate component, an inert fluid in the isocyanate component as long as it can be substantive completely dissolved, it may be appropriately adjusted depending on the purposes and applications, for example, , 1-500 seconds der Rukoto is preferable.
[0026]
Next, the process in the polyol supply unit 3 will be described. In the polyol supply unit 3, first, the polyol component stored in the raw material tank 7 is supplied to the premixing unit 15 by the raw material fixed supply pump 9 at a pressure of, for example, 10 to 30 MPa, and at the same time, inactive. The inert fluid stored in the fluid tank 11 is supplied to the preliminary mixing unit 15 by the inert fluid constant supply pump 13 at a pressure of 10 to 30 MPa, for example. As a result, the polyol component and the inert fluid are supplied to the premixing unit 15 at high pressure, so that they are satisfactorily mixed by collision. The supply amount of the inert fluid is adjusted to be 0.05 to 20% by weight with respect to the whole raw material in the total of the supply amount of the inert fluid supplied to the isocyanate component described above, and premixing is performed. mixture pressure in the unit 15, adjusted to be 10 to 30 MPa.
[0027]
After the polyol component and the inert fluid supplied in this manner are continuously premixed in the premixing unit 15, the mixture of the polyol component and the inert fluid is then pressurized at 5 to 30 MPa in the high-pressure heater 17. (holding pressure), and, by heating at 30 to 100 ° C., continuously the inert fluid in the polyol component, substantially completely dissolved. Conditions for dissolving the inert fluid in the polyol component, an inert fluid in the polyol component, as long as it can be substantive completely dissolved, it may be appropriately adjusted depending on the purposes and applications, for example, , 1-500 seconds der Rukoto is preferable.
[0028]
Then, the isocyanate component in which the inert fluid is dissolved in the high-pressure heater 16 and the polyol component in which the inert fluid is dissolved in the high-pressure heater 17 are mixed in the mixing head 4 and injected and reacted at high pressure. While injecting into the mold 5. The reaction mixing pressure in the mixing head 4 is preferably 10 to 250 MPa. Further, the reaction equivalent ratio of the isocyanate component and the polyol component (isocyanate active group: polyol active group) may be appropriately selected depending on the conditions.
[0029]
The mold 5 is preferably pre-pressurized at 1 to 15 MPa by the pressure cylinder 18 and further kept constant at 20 to 150 ° C. By preloading, the expansion speed of the inert fluid can be suppressed and fine cells can be formed.
[0030]
And after completion | finish of reaction, a microcellular polyurethane foam can be obtained by decompressing the metal mold | die 5 to normal temperature and opening a mold. The microcellular polyurethane foam thus obtained has a fine cell diameter of 100 μm or less, preferably 30 μm, and can be used effectively in various fields.
[0031]
Thus, in the polyurethane foam reaction injection molding apparatus 1 of this embodiment, in the isocyanate supply unit 2, the isocyanate component is quantitatively supplied by the raw material fixed supply pump 8, and the inert fluid is fixed by the inert fluid fixed supply pump 12. After the isocyanate component and the inert fluid are continuously premixed by the premixing unit 14 at a constant ratio, the inert fluid is continuously dissolved in the isocyanate component by the high-pressure heater 16. The In the polyol supply unit 3, the polyol component is quantitatively supplied by the raw material quantitative supply pump 9, and the inert fluid is quantitatively supplied by the inert fluid quantitative supply pump 13. The polyol component and the inert fluid are always constant. After being continuously premixed by the premixing unit 15 at a ratio, the inert fluid is continuously dissolved in the polyol component by the high-pressure heater 17. The isocyanate component and the polyol component in which the inert fluid is dissolved are injected at a high pressure by the mixing head 4 and injected into the mold while reacting, whereby RIM molding is performed.
[0032]
Therefore, the inert fluid is always mixed and dissolved in the isocyanate component and the polyol component at a constant rate, and the reaction injection molding is performed in that state. Therefore, the microcellular polyurethane foam having a small cell diameter can be easily and quickly formed. Can be molded.
[0033]
In each of the high-pressure heaters 16 and 17, a mixture of each isocyanate component or polyol component and an inert fluid premixed at a certain ratio is pressurized and / or heated, so that each isocyanate component or polyol The inert fluid is sufficiently dissolved in the components, whereby a microcellular polyurethane foam having a small cell diameter can be well formed.
[0035]
Further, in the polyurethane foam reaction injection molding apparatus 1 of this embodiment, since the mold 5 is pre-pressurized, the expansion speed of the inert fluid in the cavity is suppressed, and finer cells are formed. A microcellular polyurethane foam having a small diameter can be formed.
[0036]
Note that in the polyurethane foam reaction injection molding apparatus 1 of this embodiment, the inert fluid used is carbon dioxide or nitrogen which is an inert gas at room temperature and normal pressure. It may be in liquid form, and after being quantitatively supplied by inert fluid constant supply pumps 12 and 13 and continuously premixed by premixing units 14 and 15, it becomes a high-temperature high-pressure state or a supercritical state. It is preferable that the conditions are set as described above.
[0037]
Further, in the polyurethane foam reaction injection molding apparatus 1 of this embodiment, the isocyanate supply unit 2 and the polyol supply unit 3 have substantially the same apparatus configuration, and the raw material metering supply pumps 8 and 9 and the inert fluid are provided in both of them. The fixed amount supply pumps 12 and 13, the premixing units 14 and 15, and the high-pressure heaters 16 and 17 are provided. However, depending on the purpose and application, only one of the isocyanate supply unit 2 and the polyol supply unit 3 can supply these raw materials. The fixed amount supply pumps 8 and 9, the inert fluid fixed amount supply pumps 12 and 13, the premixing units 14 and 15, and the high pressure heaters 16 and 17 may be provided.
[0038]
Such a polyurethane foam reaction injection molding apparatus 1 can be applied to any of rigid, semi-rigid and soft polyurethane foams.
[0039]
Furthermore, in the above description, the example in which the reaction injection molding apparatus of the present invention is applied to the production of a microcellular polyurethane foam is shown. However, the reaction injection molding apparatus of the present invention is not limited to this, and reacts two components. Can be widely applied, for example, polyamide resin foam molded body, dicyclopentadiene resin foam molded body, unsaturated polyester resin foam molded body, acrylamate resin foam molded body, The present invention can also be applied to an epoxy resin foam molded body.
[0040]
【The invention's effect】
As described above, according to the invention described in claim 1, the inert fluid is always continuously mixed and dissolved in the raw material at a constant ratio, and substantially completely dissolved in the raw material. Therefore, a microcellular foamed molded product having a small cell diameter can be molded easily and in a short time.
[0041]
In addition, according to the first aspect of the present invention, the inert fluid can be substantially completely dissolved in the raw material, and a microcellular foamed molded article having a small cell diameter can be molded satisfactorily.
[0042]
According to the second aspect of the present invention, it is possible to form a microcellular foamed molded article having a smaller cell diameter by forming finer cells by preloading the mold.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a reaction injection molding apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reaction injection molding apparatus 2 Isocyanate supply unit 3 Polyol supply unit 4 Mixing head 5 Mold 6, 7 Raw material tank 8, 9 Raw material fixed supply pump 10, 11 Inactive fluid tank 12, 13 Inactive fluid fixed supply pump 14, 15 Premixing unit 16, 17 High pressure heater

Claims (2)

A raw material quantification means for quantifying the raw material;
An inert fluid quantification means for quantifying the inert fluid;
Premixing means for continuously premixing the raw material quantified by the raw material quantification means and the inert fluid quantified by the inert fluid quantification means at a mixing pressure of 10 to 30 MPa ;
In the mixture of the raw material and the inert fluid premixed by the premixing means, the mixture of the raw material and the inert fluid is pressurized at 5 to 30 MPa and heated at 30 to 100 ° C., and the inert fluid is continuously supplied to the raw material. A dissolution means for substantially complete dissolution ;
A reaction injection molding apparatus comprising: mixing injection means for injecting a raw material at a high pressure and injecting it into a mold while reacting.   The reaction injection molding apparatus according to claim 1, further comprising a preloadable mold.

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