JP3814140B2 - Plastic sheet manufacturing equipment and manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic sheet manufacturing apparatus and a manufacturing method particularly suitable for manufacturing a plastic sheet having a large size by using a template polymerization method.
[Prior art]
[0002]
A method for producing a methacrylic resin plate by polymerizing a methyl methacrylate monomer or a liquid composition (usually called syrup) containing a methyl methacrylate monomer and a polymer thereof between two molds is described in the following. It is well known as legal or cast polymerization. As the mold, a glass plate or a stainless plate is mainly used.
[0003]
In the mold polymerization method, as shown in FIG. 3, a sealing material 53 serving as a mold is disposed between the upper plate 50 and the lower plate 51 which are molds to form a polymerization molding cell 54. In order to encapsulate the molding material 52 and further regulate the thickness of the molded sheet obtained, it is conveyed to the polymerization process with a number of clamps 55 fitted around the periphery of the cell 54 and heated in an air bath or water bath. Thus, a plastic sheet such as a methacrylic resin plate is obtained.
[0004]
[Problems to be solved by the invention]
When the size of the plastic sheet to be manufactured is large (for example, a sheet having a side of about 10 m), a large polymerization molding cell 54 is prepared, the molding material 52 is enclosed in the cell, and conveyed to the polymerization process. Since it is necessary to heat and polymerize in the inside, handling such as transportation is very difficult, and a large-sized hot air furnace or the like is required for the polymerization process, resulting in a huge equipment cost.
Further, when the polymerization molding cell 54 encapsulating the molding material 52 is heated and polymerized in an air bath, the thickness distribution of the molding sheet increases as the size of the molding sheet to be manufactured increases and the sheet thickness increases. There's a problem.
[0005]
Accordingly, an object of the present invention, even at a large plastic sheet size, can be easily manufactured without requiring a large equipment, and Ru can be reduced thickness distribution difference sheet plastic It is to provide a sheet manufacturing apparatus and a manufacturing method.
[0006]
[Means for Solving the Problems]
An apparatus for producing a plastic sheet of the present invention for solving the above-described problem is a mold comprising a pair of heat transfer plates facing each other with a predetermined gap in order to enclose a monomer or a liquid composition containing a monomer, A plurality of heat pipes that are disposed on a non-wetted surface of the heat transfer plate and through which a heat medium flows , and the pair of heat transfer plates are respectively held by a plurality of jack bolts on a reinforcing frame; One end is attached to the reinforcing frame so as to be able to move forward and backward from the reinforcing frame, and the other end is provided with a flange portion, and the flange portion is slidable in the vertical and horizontal directions along the surface of the heat transfer plate. A locked portion to be locked is provided on a non-wetted surface of the heat transfer plate .
[0007]
Thus, according to the present invention, a plurality of heat pipes are provided on the non-wetted surfaces of a pair of heat transfer plates serving as a mold, and the heat medium flows through the heat pipes. The liquid transmitted from the heat pipe to the heat transfer plate and sealed with the heat between the pair of heat transfer plates can be heated and polymerized.
[0008]
Further, according to this onset bright, the pair of heat transfer plates, is held by a plurality of jack bolt each reinforcing frame, the jack bolt has one end freely advance and return from the reinforcing frame to the reinforcing frame A non-liquid contact surface of the heat transfer plate is attached to the other end, and a flange portion is provided on the other end, and the flange portion is slidably locked in the vertical and horizontal directions along the surface of the heat transfer plate. Provided . As a result, the horizontality and flatness of the heat transfer plate can be adjusted by operating jack bolts, and the deflection of the heat transfer plate can also be corrected, so that the thickness distribution of the manufactured sheet is made uniform. can do.
[0009]
Furthermore, the method for producing a plastic sheet according to the present invention performs template polymerization of a monomer or a liquid composition containing the monomer using the production apparatus described above. More particularly, the method of the present invention, after the leveling of the pair of heat transfer plate as a template to operate the jack bolt, a monomer or monomer pair of heat transfer liquid composition comprising A template of a liquid composition containing the monomer or the monomer is heated by flowing a heating medium in a heat pipe attached to the non-wetted surface of the heat transfer plate and heating the heat transfer plate. It is characterized by performing.
Thus, a large plastic sheet can be produced easily and with a small thickness distribution difference without requiring a large facility as in the case of an air bath or a water bath.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows a part of a plastic sheet molding cell according to this embodiment. In other words, this molding cell has a pair of heat transfer plates 1 and 2 (in the following description, sometimes referred to as an upper plate 1 and a lower plate 2) as a mold, and a predetermined mold for enclosing a liquid molding material. It is opposed with a gap C. An elastic sealing material 3 is provided on the opposite liquid contact surface peripheral portions of the heat transfer plates 1 and 2 to form a mold and to regulate the thickness of molding. A plurality of heat pipes 4 and 5 are arranged at predetermined intervals on the non-wetted surfaces of the heat transfer plates 1 and 2.
[0011]
Examples of the heat transfer plates 1 and 2 include plate materials that have high thermal conductivity, have a flat surface, do not cause contamination of the resin sheet, and are available in a sufficiently large size. Examples of such a plate material include a stainless plate, an aluminum plate, a copper plate and the like, and it is particularly preferable to use a stainless plate. The liquid contact surfaces of the heat transfer plates 1 and 2 are mirror-finished in order to improve releasability from the molded plastic sheet.
[0012]
As the liquid molding material, a monomer capable of bulk polymerization or a syrup containing the monomer and a polymer thereof, and a liquid composition obtained by adding a polymerization initiator to the syrup are used. A typical example of the monomer is methyl methacrylate, but in addition, (meth) acrylic acid-based resin, acrylic resin containing methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, styrene, etc. as comonomers. Resin monomers capable of bulk polymerization such as impact-resistant (meth) acrylic acid-based resins and polystyrene-based resins containing diene rubbers can also be used.
The elastic sealing material 3 serves as a mold and is made of polyvinyl chloride, polyester or the like.
[0013]
As the heat pipes 4 and 5, as shown in FIG. 1, the use of a square heat pipe having a square cross section increases the contact area with the heat transfer plates 1 and 2, so that heat exchange can be performed efficiently. preferable. As the material of the heat pipes 4 and 5, it is preferable to use a material having high thermal conductivity, and examples thereof include stainless steel, aluminum, copper and the like, and copper is particularly preferable.
[0014]
In order to perform heat exchange with high efficiency, the heat pipes 4 and 5 are preferably attached in close contact with the non-wetted surfaces of the heat transfer plates 1 and 2, respectively. For this reason, the heat pipes 4 and 5 are bonded to the non-wetted surfaces of the heat transfer plates 1 and 2 with a heat conductive adhesive. As the heat conductive adhesive, for example, a mixture of about 10 to 90% by weight of a heat conductive material such as graphite and stainless steel with a thermosetting resin such as an epoxy resin can be used.
[0015]
The heat conductive adhesive is uniformly applied with a trowel, a spatula or the like on the back surface of the heat pipes 4 and 5 and / or the entire non-wetted surface of the heat transfer plates 1 and 2 and cured. At this time, the thickness of the adhesive layer interposed between the heat pipes 4 and 5 and the heat transfer plates 1 and 2 should be about 2 mm or less, preferably 1 mm or less, and the thickness is larger than this. As a result, the heat exchange efficiency may be reduced.
As the heat medium flowing in the heat pipes 4 and 5, for example, warm water, high-boiling organic solvents, or mixtures thereof can be used, and it is particularly preferable to use warm water that is easy to handle. In the case of warm water, when high temperature of 100 ° C. or higher is required, pressurize and use.
[0016]
As shown in FIG. 2, the heat transfer plates 1 and 2 are held on the reinforcing frames 6 and 7 by jack bolts 8 and 9. That is, in the case of the upper plate 1 of the heat transfer plate, as shown in FIG. 2A, one end of the jack bolt 8 is inserted through the insertion hole 10 provided in the reinforcing frame 6 and the tip is screwed with the nut 12. To do. On the other hand, a flange portion 14 is integrally attached to the other end of the jack bolt 8, and this flange portion 14 is locked to a locked portion 16 provided on the non-wetted surface of the heat transfer plate 1. As a result, the heat transfer plate 1 is suspended from the reinforcement frame 6 by the jack bolts 8.
In the case of the heat transfer plate 2, as shown in FIG. 2 (b), one end of the jack bolt 9 is screwed into the screw hole 11 provided in the reinforcing frame 7, and the tip is screwed into the nut 13. Thus, the frame 7 is fixed. On the other hand, a flange portion 15 is integrally attached to the other end of the jack bolt 9, and the heat transfer plate 2 is attached to the jack bolt 9 by the flange portion 15 coming into contact with the non-wetted surface of the heat transfer plate 2. Retained.
[0017]
The heat transfer plates 1 and 2 are respectively held by jack bolts 8 and 9 arranged at a plurality of positions, for example, in the vertical and horizontal directions of the non-wetted surface. Then, by rotating the nuts 12 and 13 and the jack bolts 8 and 9 screwed to the jack bolts 8 and 9 to move the jack bolts 8 and 9 forward or backward, the horizontality and flatness of the heat transfer plates 1 and 2 are increased. Adjust. The holding positions of the heat transfer plates 1 and 2 by the jack bolts 8 and 9 may be at least near the four corners of the heat transfer plates 1 and 2, but in order to correct the deflection of the heat transfer plates 1 and 2, In this way, it is preferable to dispose a plurality of them at predetermined intervals in the vertical and horizontal directions of the non-wetted surface.
[0018]
The locked portions 16 and 17 are provided with slits 18 and 19 at the center, and the main bodies of the jack bolts 8 and 9 are inserted through the slits 18 and 19. In the upper plate 1 of the heat transfer plate, the flange portion 14 abuts on the inner edge of the slit 18 to hold the upper plate 1. On the other hand, in the lower plate 2, the flange portion 15 directly supports the lower plate 2, but not all the flange portions 15 may be in contact with the lower plate 2. For example, for adjusting the strain, the lower plate 2 is supported by the jack bolt 9 near the end, and the flange portion 15 of the jack bolt 9 at the center is locked to the inner edge of the slit 19 of the locked portion 17, The lower plate 2 may be pulled.
In any case, a gap is formed between the slits 18 and 19 and the main body of the jack bolts 8 and 9 and between the inner side walls of the locked portions 16 and 17 and the flange portions 14 and 15. The heat transfer plates 1 and 2 are slidable with respect to the jack bolts 8 and 9 in the vertical direction and the horizontal direction along the surface of the heat transfer plates 1 and 2 (x and y directions in FIG. 2 (b)). (However, the y direction is a direction along the longitudinal direction of the slits 18 and 19). For this reason, even if a thermal expansion difference arises between the heat-transfer plates 1 and 2 and the reinforcement frames 6 and 7, this expansion difference can be escaped.
[0019]
Further, since the jack bolt 8 is only inserted through the insertion hole 10 of the reinforcing frame 6, the molding material sandwiched between the upper plate 1 and the lower plate 2 is liquid-expanded during the heat polymerization and the upper plate 1. Since the jack bolt 8 is also lifted along with this, the liquid expansion can be escaped.
The gap between the upper plate 1 and the lower plate 2, and thus the thickness distribution of the manufactured sheet, is adjusted by moving the jack bolts 8 and 9 forward or backward relative to the fixed frames 6 and 7.
[0020]
Next, a method for producing a plastic sheet by mold polymerization using the production apparatus of the present invention will be described. First, after the heat transfer plates 1 and 2 are leveled as described above, the sealing material 3 serving as a mold is attached to the periphery of the liquid contact surface of the lower plate 2, and the upper plate 1 is placed on the sealing material 3. After that, a monomer as a raw material or a liquid composition containing the monomer is injected into the sealing material 3. In this state, the upper plate 1 and the lower plate 2 are heated through a heat medium in the heat pipes 4 and 5 attached to the upper plate 1 and the lower plate 2 to mold and polymerize a monomer or a liquid composition containing the monomer. I do. The polymerization temperature is usually 50 to 90 ° C, preferably 60 to 80 ° C. The polymerization time is usually 30 to 60 hours. After the polymerization, heat treatment at about 110 to 130 ° C. may be performed as necessary.
[0021]
Since the thermal expansion difference and liquid expansion between the heat transfer plates 1 and 2 and the reinforcing frames 6 and 7 generated in the polymerization process are corrected as described above, the heat transfer plates 1 and 2 are bent or deformed. Therefore, a sheet with high dimensional accuracy can be obtained.
[0022]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0023]
As the heat transfer plates 1 and 2 serving as the molds of the examples, stainless steel plates (SUS304) having a length of 9200 mm, a width of 3900 mm, and a thickness of 20 mm were used. On the non-wetted surfaces of the heat transfer plates 1 and 2, rectangular copper heat pipes 4 and 5 (thickness 2 mm, external dimensions: 11 mm long × 30 mm wide × 3900 mm long) as shown in FIG. 96 were attached respectively. The heat pipe was attached with a highly heat conductive adhesive ("Thermocon R" manufactured by NICHIAS). The thickness of this adhesive layer was about 0.5 mm. Then, as shown in FIG. 2, the heat transfer plates 1 and 2 were held and held on the reinforcing frame by 171 jack bolts 8 and 9 arranged at equal intervals on the non-wetted surface.
The heat transfer plates 1 and 2 are leveled with the jack bolts 8 and 9, the seal material 3 as a mold is attached to the periphery of the wetted surface of the lower plate 2, and the upper plate 1 is placed on the upper plate 1. After that, a liquid composition in which a polymerization initiator was added to methyl methacrylate was injected and sealed with heat transfer plates 1 and 2. Then, pressurized hot water was allowed to flow as a heat medium in the heat pipes 4 and 5 and polymerization was performed at 50 to 120 ° C. for 40 hours to obtain an acrylic sheet having a length of 8500 mm, a width of 3500 mm, and a thickness of 34 mm. The obtained acrylic sheet had a maximum thickness of 36 mm and a minimum value of 32 mm in one sheet, and the difference in thickness distribution was small.
[0024]
【The invention's effect】
According to the manufacturing apparatus and the manufacturing method of the present invention, the heat transfer plate is heated by the heat of the heat medium flowing in the heat pipe, and the liquid composition containing the monomer or the monomer enclosed between the pair of heat transfer plates Since the product is polymerized, there is an effect that even a large plastic sheet can be easily manufactured without requiring a large facility.
Further, in the present invention, the pair of heat transfer plates are respectively held on the reinforcing frame by a plurality of jack bolts , and one end of the jack bolt is attached to the reinforcing frame so as to be able to advance and retract from the reinforcing frame, and the other end is attached to the other end. A flange portion is provided, and a hooked portion is provided on the non-wetted surface of the heat transfer plate so that the flange portion is slidably locked in the vertical and horizontal directions along the surface of the heat transfer plate. Since the levelness and flatness of the plate can be adjusted by operating jack bolts, and the deflection of the heat transfer plate can also be corrected, the thickness distribution of the manufactured sheet can be made uniform.
[Brief description of the drawings]
FIG. 1 is a partially broken perspective view showing a plastic sheet manufacturing apparatus according to an embodiment of the present invention.
FIGS. 2A and 2B are schematic sectional views showing holding structures for an upper plate and a lower plate, respectively. FIG. 3 is a partially broken perspective view showing a normal plastic sheet molding cell.
[Explanation of symbols]
1 Heat transfer plate (upper plate)
2 Heat transfer plate (lower plate)
3 Sealing material 4 Heat pipe 5 Heat pipe 6 Reinforcement frame 7 Reinforcement frame 8 Jack bolt 9 Jack bolt

Claims (6)

A mold composed of a pair of heat transfer plates facing each other with a predetermined gap to enclose a monomer or a liquid composition containing a monomer, and a heat medium flows on a non-wetted surface of the heat transfer plate A plurality of heat pipes, and the pair of heat transfer plates are respectively held by a plurality of jack bolts on a reinforcing frame, and one end of the jack bolt is attached to the reinforcing frame so as to be movable forward and backward from the reinforcing frame. In addition, a flange portion is provided at the other end, and the flange portion is slidably locked in the longitudinal direction and the lateral direction along the surface of the heat transfer plate. provided apparatus for producing a plastic sheet.   The manufacturing apparatus according to claim 1, wherein the heat transfer plate is a stainless steel plate.   The manufacturing apparatus according to claim 1, wherein the heat pipe is a square heat pipe having a square cross section.   The manufacturing apparatus according to claim 1, wherein the heat pipe is bonded to a non-wetted surface of the heat transfer plate with a heat conductive adhesive. The manufacturing apparatus according to any one of claims 1 to 4, wherein the pair of heat transfer plates are held by jack bolts arranged in a plurality in a vertical direction and a horizontal direction of a non-wetted surface , respectively. In the manufacturing apparatus in any one of Claims 1-5, after operating a jack bolt and leveling a pair of heat exchanger plate used as a casting_mold | template, the liquid composition containing a monomer or a monomer is used. enclosed in the pair of heat transfer plates, this plurality of heat pipe attached to non-wetted surface of the heat transfer plate by supplying a heating medium to heat the heat transfer plate comprises the monomer or monomers A method for producing a plastic sheet, comprising performing template polymerization of a liquid composition.

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