JP2006326947A - Transparent hollow plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent hollow plate which has a good heat insulating action, suppresses the occurrence of bedewing and clouding, has impact resistance, and is excellent in fluoroscopy properties. <P>SOLUTION: In the hollow plate, two amorphous polyethylene terephthalate plates 1 and 1 are piled in parallel with a space formed between them, and its four rims are welded to form a hollow layer 3. In the transparent hollow plate P1, the total light transmittance of a part forming the hollow layer 3 of the plate is at least 40%, and the haze of the part is 3% or below. The bedewing and clouding of the plate can be prevented by the heat insulating action of the hollow layer 3. The impact resistance strength is large since the amorphous polyethylene terephthalate plates 1 and 1 are used. Since the total light transmittance of the part forming the hollow layer 3 is at least 40%, and the haze of the part is 3% or below, the plate is good in transparency and excellent in fluoroscopy properties. Vent holes connected to the hollow layer can be formed in at least two places of the welded four rims. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transparent hollow plate that is suitably used as a material for a viewing window of a cold insulation facility, for example.

  In general, the cold insulation equipment insulates using a heat insulating material having a sandwich structure in which a foam such as polyurethane is sandwiched between metal foils such as aluminum, thereby enhancing the cold insulation effect. In such a cold insulation facility, a viewing window is provided to look inside, and a synthetic resin plate or the like is often used as a material for the viewing window. However, a viewing window made of a synthetic resin plate has a problem that condensation and fogging are likely to occur because of its little heat insulating effect.

On the other hand, as a transparent plate having a heat insulating action, for example, a multilayer in which a heat insulating space is formed between the transparent glass plates by interposing an interval holding material between the four peripheral edges of the two transparent glass plates and bonding and sealing with an adhesive. A transparent plate is known (Patent Document 1). This multi-layer transparent plate is used for transparent doors in frozen showcases, but the transparent glass plate is inferior in impact resistance, so there is a risk of cracking when subjected to an impact, and the moisture in the heat insulation space In order to prevent the fogging caused, it is necessary to hold the desiccant in the interval holding frame, and there is a problem that it is difficult to replace the desiccant.
Japanese Patent No. 2804536

  The present invention has been made in view of the above problems, and provides a transparent hollow plate that has excellent heat insulation, is resistant to condensation and fogging, has impact resistance, is lightweight, and has excellent transparency. It is a problem to be solved.

  In order to solve the above-mentioned problems, the transparent hollow plate of the present invention is a hollow plate in which two amorphous polyethylene terephthalate plates are stacked in parallel at intervals, and the four peripheral edges are welded to form a hollow layer, The portion of the plate where the hollow layer is formed has a total light transmittance of 40% or more and a haze of 3% or less.

  In the transparent hollow plate of the present invention, air holes that communicate with the hollow layer may be formed in at least two positions of the four welded peripheral edges. Moreover, you may form in the hollow layer the reinforcement part connected and supported by a part of two amorphous polyethylene terephthalate board spaced apart.

  In the transparent hollow plate of the present invention, a hollow layer is formed on the inner sides of the four welded peripheral edges, and this hollow layer exerts a heat insulating action, so that, for example, peeping in a cold insulation facility, a cold insulation line for food production, a cold insulation vehicle, an air conditioning facility, etc. Even when used for windows or the like, condensation or fogging hardly occurs on the surface of the polyethylene terephthalate plate. In addition, since the amorphous polyethylene terephthalate plate has good impact resistance and its four peripheral edges are welded, the transparent hollow plate of the present invention has high impact resistance strength and rigidity, and external impact Even if it receives force, it is hard to break. Moreover, since the transparent hollow plate of the present invention has a total light transmittance of 40% or more and a haze of 3% or less at the portion where the hollow layer is formed, the transparency is good and the transparency is excellent. It is suitable as a material plate.

  In addition, the transparent hollow plate in which the air holes leading to the hollow layer are formed in at least two places on the four peripheral edges is one air hole when the water in the hollow layer is cooled and the inner surface of the polyethylene terephthalate plate is clouded. Then, the air on the inner surface of the polyethylene terephthalate plate can be easily removed by supplying air into the hollow layer and exhausting it from the other vent hole.

  In addition, a transparent hollow plate in which a reinforcing part that supports and supports a part of two amorphous polyethylene terephthalate plates spaced apart from each other is formed in a hollow layer is not recessed even if the hollow layer has a large area. There is nothing to do. In particular, even if a thin polyethylene terephthalate plate is used, the strength and rigidity of the hollow layer can be maintained by the reinforcing portion, so that the weight can be reduced.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view of a transparent hollow plate according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the transparent hollow plate.

  This transparent hollow plate P1 includes two layers of amorphous polyethylene terephthalate plates 1 and 1 stacked in parallel at an interval in the vertical direction, and a band plate made of the same amorphous polyethylene terephthalate in the four peripheral spaces. The hollow layer 3 is formed on the inner side of the four peripheral edges by welding and integrating with the spacer 2 in between.

  The polyethylene terephthalate plate 1 needs to use an amorphous material having good impact resistance and transparency, and a typical example of such an amorphous polyethylene terephthalate plate is polyethylene. Examples include polyethylene terephthalate plates in which 10-70% of the ethylene glycol component in terephthalate is replaced with 1,4-cyclohexanedimethanol (for example, a plate obtained by extruding an amorphous polyethylene terephthalate resin “SPECAR” manufactured by Eastman Chemical Co., Ltd.). . This amorphous polyethylene terephthalate plate has higher impact strength than polymethylmethacrylate plate, does not contain harmful chlorine like polyvinyl chloride plate, has transparency comparable to polycarbonate plate, There are advantages such as a melting point lower than that of a polycarbonate plate and easy high-frequency welding, and it is optimal as a material plate for a transparent hollow plate.

  In order for the transparent hollow plate P1 to have good transparency and excellent transparency, the total light transmittance of the portion where the hollow layer 3 is formed is 40% or more, the haze is 3% or less, preferably 70% each. % To 1% or less. To that end, the total thickness of the two polyethylene terephthalate plates 1 and 1 needs to be 20 mm or less. When the total thickness is further reduced, the total light transmittance is further increased, the haze is further decreased, and the transparency and transparency are further improved. The thickness of the polyethylene terephthalate plate 1 is preferably at least 1 mm. Since the preferable total light transmittance of the portion where the hollow layer 3 is formed is 70% or more and the preferable haze is 1% or less, the preferable total thickness of the polyethylene terephthalate plates 1 and 1 is 10 mm or less, and the more preferable total thickness is 8 mm or less. is there.

  In this embodiment, the two polyethylene terephthalate plates 1 and 1 have the same thickness, but needless to say, they may have different thicknesses. Further, the size of the polyethylene terephthalate plates 1 and 1 may be a size suitable for the use of the transparent hollow plate P1, and is about 100 × 100 cm, for example. In the case of a peep window or the like of a cold insulation line for food production that is a specific application, one side may be usually about 10 cm in size.

  The strip-like spacer 2 is sandwiched between the four peripheral edges to secure the hollow layer 3 between the two polyethylene terephthalate plates 1, 1, and is the same amorphous as the polyethylene terephthalate plate 1. A spacer made of polyethylene terephthalate is used. The thickness of the hollow layer 3 is preferably 2 to 10 mm in consideration of the heat insulating effect. Therefore, it is preferable to use a spacer 2 having a thickness of 2 to 10 mm.

  For the four-round welding of the two polyethylene terephthalate plates 1 and 1, any of the known welding methods such as high-frequency welding, ultrasonic welding, and heat welding can be employed. High frequency welding having the advantage of being able to weld a polyethylene terephthalate plate is most preferably employed. In addition, when welding the polyethylene terephthalate plates 1, 1, it is preferable to carry out in an environmental state where moisture is reduced. As a result, moisture in the hollow layer 3 can be reduced. It is possible to effectively prevent the occurrence of condensation and clouding.

When the transparent hollow plate P1 having the above-described configuration is attached to, for example, a metal window frame of the observation window of the cold insulation facility, heat absorption from the observation window is prevented by the heat insulating action of the hollow layer 3, and the polyethylene terephthalate plate 1 Condensation and fogging on the surface are prevented. Since the total light transmittance of the portion where the hollow layer 3 on the inner periphery of the four peripheral edges is 40% or more and the haze is 3% or less, the transparency is good and the transparency is excellent, the transparent hollow plate of this viewing window The inside of the facility can be clearly seen through P1. Moreover, since the transparent hollow plate P1 uses the amorphous polyethylene terephthalate plate 1 having high impact resistance and other mechanical strength, there is no fear of being easily damaged even when receiving an impact force from the outside. .
And since the four peripheral edges have a triple structure of the polyethylene terephthalate plates 1 and 1 and the spacer 2, they have rigidity, do not bend, can be drilled, and other members It is easy to mount on.

  In addition, although the hollow layer 3 was ensured by using the spacer 2 in the said embodiment, you may ensure in any other forms. For example, using a deformed plate material that has a recess formed in the center by performing secondary processing such as vacuum forming on a polyethylene terephthalate plate, and then welding the four peripheral edges after overlapping the recessed portions of the two deformed plate materials facing each other Alternatively, it can be ensured by, for example, superposing and welding the concave portion of the deformed plate material on the flat plate surface. Furthermore, the strength and rigidity of the hollow layer may be increased by partially connecting and supporting the upper and lower amorphous polyethylene terephthalate plates 1 and 1 with a reinforcing portion shown in FIG.

  Furthermore, by adding pigments or dyes to the polyethylene terephthalate plate and blocking the wavelength of 300 nm or less, preferably 500 nm or less to prevent insects from flying, there is no risk of insects being mixed into food. be able to. In this case, the total light transmittance is 40 to 60%, and the haze is about 0.2 to 1.0%. In addition, antibacterial agents such as copper and silver can be added to impart an antibacterial action, or an antifungal agent can be added to prevent generation of wrinkles even if condensation occurs. In addition, an antistatic layer containing a conductive material is formed on the surface to provide an antistatic function to prevent dust adhesion, or an infrared absorber is added to absorb heat rays, thereby increasing the indoor temperature. Can be efficiently prevented.

  FIG. 3 is a plan view of a transparent hollow plate according to another embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line ABCD of FIG.

  This transparent hollow plate P2 is formed with two vent holes 4 and 4 passing through the spacer 2 at the four peripheral edges of two polyethylene terephthalate plates 1 and 1 welded with the spacer 2 interposed therebetween. In addition, an appropriate number of tap holes 5 are formed on the four peripheral edges so that they can be easily screwed. One of the vent holes 4 and 4 is used as an air supply hole and the other is used as an exhaust hole. Air supplied from one vent hole flows uniformly through the hollow layer 3 and is exhausted from the other vent hole. As shown in the figure, the two air holes 4 and 4 are formed at two locations separated in a substantially diagonal direction. In the normal state, the vent hole 4 is closed with a stopper (not shown) or the like so as to prevent air from flowing and to exhibit heat insulation performance. In addition, the vent holes 4 may be formed at three or more locations on the four peripheral edges.

  Since the other structure of this transparent hollow plate P2 is the same as that of the transparent hollow plate P1 mentioned above, it attaches | subjects the same code | symbol to the corresponding member in FIG. 3, FIG. 4, and abbreviate | omits description.

  Such a transparent hollow plate P2 has a function such as a plug when the moisture in the hollow layer 3 is cooled and the inner surface of the polyethylene terephthalate plate 1 is clouded in addition to the same effect as the transparent hollow plate P1 described above. Are removed, the vent holes 4 and 4 are opened, air is supplied from the one vent hole 4 into the hollow layer 3 and exhausted from the other vent hole 4, so that the inner surface of the polyethylene terephthalate plate 1 can be easily fogged. It also has the effect that it can be removed.

  FIG. 5 is a partially broken perspective view of a transparent hollow plate according to still another embodiment of the present invention.

  The transparent hollow plate P3 is provided with a plurality of reinforcing portions 6 that support and support the upper and lower two amorphous polyethylene terephthalate plates 1 and 1 inside the hollow layer 3. As the reinforcing portion 6, a synthetic resin piece that can be welded to the upper and lower polyethylene terephthalate plates 1 and 1 without impairing the transparency and transparency of the hollow plate P3 is used. Strips and blocks are preferably used. These reinforcing members 6 are arranged with a gap therebetween, so that air supplied from one vent hole 4 flows through the hollow layer 3 through the gap between the reinforcing members 6, and the other vent hole 4. It is preferable that the air is exhausted from the air.

  Since the other structure of this transparent hollow plate P3 is the same as that of the transparent hollow plate P2 mentioned above, it attaches | subjects the same code | symbol to the corresponding member in FIG. 5, and abbreviate | omits description.

  Since such a transparent hollow plate P3 is improved in strength and rigidity by the reinforcing portion 6 in addition to the above-described effects of the transparent hollow plate P2, the upper and lower polyethylene terephthalate plates 1 can be used even if the hollow layer 3 has a large area. , 1 does not dent, and even if thin polyethylene terephthalate plates 1, 1 are used, the strength and rigidity are maintained by the reinforcing portion 6, so that the weight can be reduced.

  FIG. 6 is a partially broken plan view of a transparent hollow plate according to still another embodiment of the present invention.

  The transparent hollow plate P4 accommodates a breathable long bag 7 filled with a desiccant in the hollow layer 3, and draws out a take-out guide string 7a at one end of the long bag 7 from one vent hole 4 to the outside. In this state, a plastic screw plug 8 is screwed into the vent hole 4, and a similar screw plug 8 is screwed into the other vent hole 4.

  Since the other structure of this transparent hollow plate P4 is the same as that of the transparent hollow plate P2 mentioned above, it attaches | subjects the same code | symbol to the corresponding member in FIG. 6, and abbreviate | omits description.

  In such a transparent hollow plate P4, in addition to the effect of the transparent hollow plate P2 described above, the moisture in the hollow layer 3 is absorbed by the desiccant filled in the long bag 7, so that the upper and lower polyethylene terephthalate plates There is almost no clouding on the inner surface of the 1,1. When the desiccant becomes old, the screw plug 8 of one of the vent holes 4 is removed, the long bag 7 is pulled out by holding the take-out guide string 7a, and replaced with a long bag 7 filled with a new desiccant. You can also Instead of housing the long bag 7 in the hollow layer 3, the screw plug 8 is removed, and the air in the hollow layer 3 is replaced by supplying a low thermal conductivity gas containing no dry air or moisture from the vent hole 4. Then, the screw plug 8 may be screwed in and sealed to prevent fogging of the inner surface.

It is a top view of the transparent hollow plate which concerns on one Embodiment of this invention. It is sectional drawing of the transparent hollow plate. It is a top view of the transparent hollow plate which concerns on other embodiment of this invention. FIG. 4 is a cross-sectional view taken along the line A-B-C-D in FIG. 3. It is a partial fracture perspective view of the transparent hollow plate concerning other embodiments of the present invention. It is a partially broken top view of the transparent hollow plate which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Amorphous polyethylene terephthalate plate 2 Strip plate-shaped spacer 3 Hollow layer 4 Vent hole 6 Reinforcement part P1, P2, P3, P4 Transparent hollow plate

Claims (3)

  A hollow plate in which two layers of amorphous polyethylene terephthalate plates are stacked in parallel at intervals and the four peripheral edges are welded to form a hollow layer, and the total light transmittance of the portion where the hollow layer is formed is 40 % Transparent hollow plate with a haze of 3% or less.   2. The transparent hollow plate according to claim 1, wherein vent holes leading to the hollow layer are formed in at least two positions of the four welded peripheral edges.   The transparent hollow plate according to claim 1 or 2, wherein a reinforcing portion is formed in the hollow layer to be connected to and supported by a part of two amorphous polyethylene terephthalate plates spaced apart from each other.

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