JP2006346979A - Synthetic resin sheet and method of stretch-forming synthetic resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed synthetic resin sheet in which the occurrence of the trace of the air hole of a hot plate in the printed surface of the printed synthetic resin sheet is prevented and the degradation of stretch forming properties is prevented in hot plate type vacuum pressure forming and a method of stretch-forming the synthetic resin sheet. <P>SOLUTION: In the hot plate type vacuum pressure forming, after the printed surface of the printed synthetic resin sheet 15 which is set on a stretch forming mold 11 is pressed to the hot plate 17 by pressurized air-pushing from the air hole 11a of the mold 11 and vacuum-suction from the air hole 17a of the hot plate and the sheet is heated, the stretch forming is carried out by high temperature pressurized air ejected form the air hole 17a of the hot plate 17 and the vacuum suction from the air hole 11a of the mold 11. The synthetic resin sheet is printed with an ink having hardness to prevent the occurrence of the trace of the air hole in the printed surface of the sheet and elongation characteristics to prevent the degradation of the stretch forming properties of the synthetic resin sheet and stretch-formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a three-dimensional dial of an automobile instrument panel, a three-dimensional control panel of an air conditioner, a three-dimensional dial such as a three-dimensional key of a cellular phone, or a general three-dimensional synthetic resin sheet drawing molded product. Printed with stretch properties that do not generate vent holes and do not reduce drawability, applied when manufacturing from printed synthetic resin sheets in hot plate type true pressure air forming The present invention relates to a synthetic resin sheet and a drawing method of the synthetic resin sheet.

  Conventionally, the instrument panels of automobiles, control panels of air conditioners and the like have been flat in many cases, but in recent years, three-dimensional shapes have become mainstream. These instrument panels and control panels are molded parts that require light transmission (translucency), and due to their multicolored shape and design, conventional two-color molding, three-color molding, and coating laser It becomes difficult to cope with processing, and the use of an in-mold method in which a printing sheet is inserted into a molding die and integrally molded (insert molding) is rapidly increasing.

  Furthermore, also in this in-mold method, in order to ensure a deep three-dimensional shape from the conventional method in which a flat printed sheet is insert-molded, a three-dimensional sheet material that has been formed in a required shape by drawing in advance is inserted. It is requested.

  In order to draw a flat printed sheet into such a three-dimensional sheet material, various processing methods such as vacuum forming, pressure forming, vacuum pressure forming, high pressure forming, and a matched metal method are performed.

  In any processing method, a printed flat sheet is formed into a three-dimensional solid sheet, and the properties required for the printed synthetic resin sheet material include heat resistance and uniform and good elongation (stretching). Gender) is required.

  FIG. 1 to FIG. 7 show drawing by hot plate type vacuum / pressure forming method, in which the shape of a mold is given to a printing sheet printed on the surface of a synthetic resin sheet.

  1 and 2, a mold unit 13 is configured in which a predetermined mold 11 is fixed in the mold frame 10 and a mold temperature control block 12 (see FIG. 2) is provided at the lower part of the mold frame 10. The guide holes 14, 14... Projecting in the upper four directions of the mold frame 10 are inserted into the guide holes 16, 16. Install on top.

  Next, as shown in FIG. 3, the upper surface of the printing sheet 15 is brought into contact with the hot plate 17 by raising the mold unit 13, and as shown in FIG. 4, vacuum suction is performed from a large number of vent holes 17a, 17a. The printing sheet 15 is pressure-bonded to the hot plate 17 by ejecting compressed air to the printing sheet 15 side from a large number of air holes 11a, 11a.

  Next, as shown in FIG. 5, high-temperature pressure air is ejected from the numerous air holes 17a, 17a,. By performing the suction, the printing sheet 15 is drawn according to the shape of the mold 11.

  Further, as shown in FIG. 6, in order to complete the mold opening of the mold 11 by lowering the mold unit 13, and to take out the draw-formed printing sheet 15, the air holes 11a, 11a,. The compressed air is ejected from the die 11 to the side of the drawn printing sheet, and the printing sheet 15 is detached from the mold 11, and then manually drawn from the guide pins 14, 14 ... of the mold frame 10, as shown in FIG. The printed sheet 15 is taken out.

  According to such a hot plate type vacuum / pressure forming method, the print sheet 15 is brought into direct contact with the heat-controlled hot plate 17 and the compressed air is ejected from the mold to uniformly and rapidly heat the print sheet. In addition, it is possible to press the surface of the sheet against the hot plate without unevenness by jetting the compressed air from the mold, and it is possible to reduce the draw-down that occurs when the sheet is softened, and there is less design position deviation due to drawing. Excellent reproducibility can be achieved.

  However, in the hot plate type vacuum / pressure forming method described above, the ink surface of the printing sheet heated by the hot plate 17 comes into contact with the countless air holes 17a, 17a. There is a problem in that air holes are generated on the printed sheet during spraying and vacuum suction by a hot plate, and conventionally, special measures such as attaching a protective film to the ink surface have been required.

  However, there is also a problem that pasting of the protective film impairs the stretchability of the printing sheet, that is, the drawability.

In Patent Document 1, when a synthetic resin sheet heated in hot plate vacuum pressure forming is pressed against a forming die by compressed air and drawn, the overcoat layer is coated on the surface of the synthetic resin sheet that faces the forming die. Although the flatness of the flat portion of the synthetic resin sheet is enhanced by forming the concave and convex portions, no mention is made of traces of the vent holes of the hot plate.
JP 2004-181639 A

  The present invention has been made to solve the above-described problems, and in hot plate vacuum / pressure forming, there is no generation of air hole traces on the printing surface of the printing sheet, and good forming is also possible in terms of drawability. It is an object of the present invention to provide a printed synthetic resin sheet that can be performed and a method for drawing the synthetic resin sheet.

  To achieve the above object, the synthetic resin sheet according to claim 1 of the present invention is set on a mold, and the printed synthetic resin sheet is pressure-bonded to a hot plate and vacuum suction from a vent hole of the hot plate The sheet is heated by pressing the pressure air from the mold vent hole, and then the sheet is drawn by high-temperature pressure air ejected from the hot plate vent hole and vacuum suction from the mold vent hole. In the hot plate type vacuum / pressure forming, the hot plate has a vent hole diameter of 0.2 mm to 0.7 mm, the high temperature compressed air ejected from the hot plate is 0.3 MPa to 1.5 MPa (gauge), and the hot plate temperature is 170 ° C. The uniaxial elongation when the sheet is stretched in the biaxial directions perpendicular to each other is 300% or less on average (300% elongation is defined as 10 mm length being 40 mm) or uniaxial. 2% on average when stretched only in the direction In the case where the above-described drawing is performed, the printed surface of the sheet has an ink film hardness of F or more when measured by (A) JIS K5600h method, and (B) the ink film is 160 When the elongation at break in the uniaxial direction of the ink film when stretched in the biaxial directions perpendicular to each other at 140 ° C. is 140% or more, the traceability of the synthetic resin sheet is reduced without generating air hole marks. The ink is formed of an ink having both the hardness and the elongation characteristic.

  If the hardness of the ink film is less than F, the air hole traces of the hot plate are likely to be generated, and the uniaxial breaking elongation of the ink film when the ink film is stretched in the biaxial directions orthogonal at 160 ° C. is 140. If it is less than%, the drawability of the synthetic resin sheet is restricted and it becomes difficult to obtain the required three-dimensional shape.

  Speaking of molding conditions, if the vent hole diameter of the hot plate is smaller than 0.2 mm, the ventilation resistance is large and the high-temperature pressure air is weakened. If it is larger than 0.7 mm, even if the ink is the above-mentioned ink, the air hole trace becomes remarkable and is not practical. The vent hole diameter is preferably 0.5 mm from both viewpoints.

  When the hot air pressure blown from the hot plate is less than 0.3 MPa, the pressing force with which the synthetic resin sheet is pressed against the mold is weak and the ridgeline of the squeeze is rounded. Although the formability is improved and the ridgeline is sharpened, the hot plate type vacuum pressure forming machine becomes expensive, and the running cost is increased and the overall cost is increased.

  The hot plate temperature needs to be 170 ° C. If it is 170 ° C. or lower, the traces of the air holes are hardly formed, but the drawability is deteriorated.

  If the part actually formed in the vacuum / pressure forming using a mold is developed on a flat surface, it can be considered that the synthetic resin sheet is stretched in two orthogonal directions. Of course, the linear portion having no spread is stretched only in the uniaxial direction.

  In this case, the vacuum / pressure forming is performed such that the elongation of the uniaxially stretched synthetic resin sheet is 2% or more, but the ink having the above-described elongation characteristics is not necessary for the vacuum / pressure forming of less than 2%. Even ordinary inks exhibit sufficient drawability.

  However, when the elongation of the synthetic resin sheet is less than 2%, the squeezing rate is too small to obtain a sufficient squeezing effect.

  Furthermore, if the elongation in the uniaxial direction when the synthetic resin sheet is stretched in the biaxial directions perpendicular to each other is larger than 300% on average, the synthetic resin sheet becomes thin by drawing and becomes unusable or breaks.

  The thickness of the synthetic resin sheet will be further described. When the uniaxial stretching ratio of the biaxial stretching is 300%, if the sheet thickness is 5 mm, the average sheet thickness is 0.31 mm due to drawing, and the sheet thickness is practical. At 2 mm, the average is 0.13 mm, and there are some that can be used depending on the application, but there are some that cannot be used depending on the application, and 300% stretching is the limit.

  However, this does not limit the thickness of the synthetic resin sheet, and can be arbitrarily set, such as 0.3 mm thickness and 0.2 mm thickness.

  In the case of a synthetic resin sheet, for example, in the case of a polycarbonate sheet, it has a breaking elongation of 600% in a uniaxial direction at the time of biaxial stretching, and the breaking elongation of 140% of the ink having the above elongation characteristics is about 1/4 of that. .

  However, when the uniaxial rupture elongation of biaxial stretching during ink film vacuum-pressure forming is only 30%, the rupture elongation of the polycarbonate sheet is greatly affected by 600%. The sheet breaks at an elongation of about 100% (even after drawing). (It is considered as a notch effect.)

  Of course, at this time, the ink film is broken before that, and the ink film printed on the entire surface exhibits a mesh pattern or a small island pattern. This is not the case with an ink having a breaking elongation of 140%.

  Further, in order to have a breaking elongation of 140% or more, the molecular weight must be large, and a two-component curable ink or an ultraviolet curable ink is suitable. However, some of the one-component inks exhibit 140% elongation when the molecular weight is increased, and the cross-linking like the two inks is not necessarily required.

  A large molecular weight also increases heat resistance and makes it difficult to mark the vent holes.

  The printed synthetic resin sheet according to claim 2 of the present invention is characterized in that, in claim 1, the ink is a two-component curable ink.

  Further, the printed synthetic resin sheet according to claim 3 of the present invention is the ink composition according to claim 1 or 2, comprising 5 to 30 parts by weight of polymer particles having an average particle diameter of 1 to 35 μ in 100 parts by weight of ink. It is characterized by being.

  The polymer particles are fine sphere particles, but the average particle size of the polymer fine sphere particles is defined as described above because of the hardness and the limit of drawability of the hot plate where no air hole traces are generated. Is.

  At the same time, it is also a result of considering the finish of the surface of the printing surface.

  If the diameter of the polymer microsphere particles is less than 1μ, the surface irregularities are fine and flat, and the matte finish does not reflect the light required for instrument panels of automobiles, etc., and the limit is 1 to 1 7μ. On the other hand, if the polymer fine sphere particles are larger than 35 μm, the surface irregularities become large and the mat finish becomes too rough and the appearance is impaired. The roughness limit is 27-35μ. The average particle diameter of both is 1 to 35 μm.

  If the average particle diameter of the polymer particles is less than 1 μm, it is convenient for drawability, but it is not preferable because traces of vent holes in the hot plate are easily generated. If the average particle diameter is larger than 35 μm, it is difficult to make a trace of the air hole in the hot plate, but the drawability is deteriorated.

  The polymer particle content affects the fluidity and adhesiveness of the ink, the vent hole trace of the hot plate and the drawability. When the average particle size is 1 to 35μ, the polymer particles are less than 5 parts by weight. In this case, the fluidity, adhesiveness, and drawability of the ink are good, but the vent hole traces of the hot plate are easily formed. Although the air hole trace of the hot plate contained in excess of 30 parts by weight is difficult to adhere, the fluidity, adhesion and drawability deteriorate.

  Furthermore, the printed synthetic resin sheet according to claim 4 of the present invention contains, in the ink according to claim 1 or 2, 10 to 20 parts by weight of polymer particles having an average particle diameter of 2 to 20 μ in 100 parts by weight of ink. It is characterized by that.

  The average particle size of 2 to 20μ is more preferable from the viewpoint of mat finish and drawability compared to 1 to 35 microns, and the content is defined as 10 to 20 in the same manner as when the average particle size is 1 to 35μ. It is defined in terms of ink fluidity, adhesiveness, drawability, and hot plate vent holes.

  The printed synthetic resin sheet according to claim 5 of the present invention is characterized in that the ink in claim 1 is an ultraviolet curable ink.

  The printed synthetic resin sheet according to claim 6 of the present invention contains 5 to 45 parts by weight of polymer particles having an average particle diameter of 1 to 35 μ in 100 parts by weight of ink in claim 5. It is characterized by.

  The reason why the average particle size is defined as 1 to 35 μm is the same as in claim 3. The reason why the content of the polymer particles is 5 to 45 parts by weight is the same reason as in claim 3, but in the case of the ultraviolet curable ink, the upper limit of the content is different from the two-component curable ink and is contained in a larger amount. Even if it contains 45 parts by weight, the fluidity, adhesion, and drawability do not deteriorate so much.

  Further, since it is contained in a large amount, there is a tendency that the air hole traces of the hot plate are hardly attached at a higher temperature.

  Further, the printed synthetic resin sheet according to claim 7 of the present invention contains the polymer particles having an average particle diameter of 2 to 20 μ in the ink according to claim 5 in 10 to 20 parts by weight in 100 parts by weight of the ink. It is characterized by. The reason for the definition of the average particle diameter and the content of the polymer particles is the same as that in claim 4.

  Furthermore, the method of drawing a printed synthetic resin sheet according to claim 8 of the present invention is a method of pressing a printed synthetic resin sheet set on a mold onto a hot plate and applying a vacuum from a vent hole of the hot plate. After the sheet is heated by suction and pressure air pressing from the mold vent hole, the synthetic resin sheet is removed by high-temperature pressure air ejected from the hot plate vent hole and vacuum suction from the mold vent hole. In hot plate vacuum / pressure forming, which is designed to be drawn, the hot plate has a vent hole diameter of 0.2 mm to 0.7 mm, the high temperature compressed air ejected from the hot plate is 0.3 MPa to 1.5 MPa (gauge), and the hot plate temperature Is equal to or higher than 170 ° C., and the uniaxial elongation when the synthetic resin sheet is stretched in the biaxial directions orthogonal to each other is 300% or less on average, or the elongation when it is stretched only in the uniaxial direction is 2% or more Before vacuum / pressure forming, The printing surface of the sheet is (A) the hardness of the ink film when measured by the JIS K5600 method is F or more, and (B) the ink film when the ink film is stretched in the biaxial direction orthogonal to 160 ° C. Synthetic resin formed by ink having both the hardness and the elongation characteristics, which has a uniaxial breaking elongation of 140% or more, does not generate a vent hole mark, and does not deteriorate the drawability of the sheet. The sheet is set on a mold, the sheet is pressed against a hot plate, the printed sheet is heated by vacuum suction from the vent hole of the hot plate and pressure air pressure from the vent hole of the mold, and then the heat The sheet is drawn by high-temperature pressure air ejected from a vent hole of the plate and vacuum suction from the vent hole of the mold.

  As the synthetic resin sheet, a polycarbonate resin sheet, a polyester resin sheet, a polyvinyl chloride resin sheet, or the like is used, but is not limited thereto.

  The polymer particles contained in the ink are preferably natural polymers such as powdered cellulose and powdered protein. In addition, synthetic resin powders such as poly (meth) acrylic acid ester (co) polymers, polyurethane resins, silicon resins, and tetrafluoroethylene resins can also be used. Further, these resin powders may be used in combination.

  The shape of the polymer particles is preferably spherical.

  The ink binder resin preferably has both flexibility and heat resistance so that the ink does not peel off from the printed synthetic resin sheet during drawing and cracks do not occur.

  Examples of such binder resins include polyester resins, polyurethane resins, (meth) acrylic ester resins, vinyl chloride resins, vinyl acetate copolymers, polycarbonate resins, urethane resins, and the like.

  The resin as the main material of the binder resin is preferably a crosslinkable one having a functional group, and the crosslinkable ink is generally effective for improving the heat resistance of the printed matter. Examples of the crosslinkable ink include two-component curable ink and ultraviolet curable ink.

  Examples of ink composition are as follows.

Polyester resin with OH period: 30 parts by weight Ketone solvent: 25 parts by weight Aromatic hydrocarbon solvent: 25 parts by weight Urethane resin powder: 15 parts by weight (fine spherical particles with a diameter of 2 to 20μ)
Additive ... 5 parts by weight Isocyanate-based crosslinking agent ... 5 parts by weight

  In the present invention, the printed synthetic resin sheet drawn as described above is trimmed into a desired shape and used as it is, and an in-mold method in which this is inserted into an injection mold and integrally molded There are some that are used.

  According to the present invention, the printed synthetic resin sheet formed by drawing with a hot plate type vacuum / pneumatic molding machine does not cause a hot plate vent hole mark on the printing surface, and the printed ink is formed on the synthetic resin sheet. There is no reduction in drawability. Therefore, it is possible to obtain a three-dimensional synthetic resin sheet that is beautiful and has a sharp ridgeline.

  The present invention will be described below with reference to the drawings.

  Printing is performed on one side of a polycarbonate sheet having a thickness of 0.5 mm with a two-part curable ink, and printing is performed on the opposite side with a normal one-part type ink (FIG. 8 (a)). For two-part curable inks, the scales and numbers of automobile speedometers, tachometers, fuel meters and thermometers were printed. With one-component ink, color printing required for the instrument was performed.

  The two-component curable ink is composed of a polyester resin having an OH group as a main ingredient and an aromatic hydrocarbon solvent, and an isocyanate-based crosslinking agent. The hardness of the ink film of the two-component curable ink at this time was F, and the elongation at break in the uniaxial direction of the ink film when stretched in the biaxial directions perpendicular to each other at 160 ° C. was 195%. The hardness of the ink film of a normal one-component ink was B, and the elongation at break in the uniaxial direction of the ink film when stretched in the biaxial directions perpendicular to each other at 160 ° C. was 45%. The printed polycarbonate sheet was set on a mold as shown in FIG. 2 so that the printing surface of the two-part curable ink of the polycarbonate sheet faced the hot plate of a hot plate type vacuum pressure forming machine. The outer shape of the mold frame is as shown in Fig. 1. The outer dimensions are 500mm in width, 250mm in depth, 80mm in height, and 5mm in depth of the surrounding standing wall. The dimensions of the mold are large equivalent to a speedometer or tachometer. The diameter of the circle was 100 mm, the diameter of the small circle corresponding to the fuel gauge or thermometer was 48 mm, and the depth of the mold corresponding to the drawing depth was 5 mm. The angle between the bottom surface and the standing wall in the mold was 24 degrees, the curvature radius of the bottom corner was 0.3 mm, and the curvature radius of the top corner was 0.9 mm.

  The temperature of the hot plate was 190 ° C, and the temperature of the mold was 65 ° C.

  Next, the mold is raised (FIG. 3), the polycarbonate sheet is brought into contact with the hot plate, 0.3 MPa (gauge) compressed air is ejected from the vent of the mold, and 0.09 MPa from the 0.5 mmΦ vent of the hot plate. (Gauge) is vacuumed and the sheet is pressed and heated to the hot plate (FIG. 4), and then 0.07 MPa (gauge) is vacuum sucked from the mold vent and 1.0 MPa (1.0 MPa ( Gage) was set at 300 ° C., and the sheet was drawn along the mold (FIG. 5).

  Next, the mold was lowered (FIG. 6), and the three-dimensional sheet was taken out (FIG. 7). There was almost no trace of vent holes in the hot plate on the surface of the surface of the automotive instrument plate of the resulting three-dimensional polycarbonate sheet, and the ridgeline of the aperture was also sharply formed.

  The average elongation in the direction parallel to the standing wall of the standing wall portion (drawing portion) (vertical uniaxial direction) was about 20%.

  The two-component curable ink of Example 1 was printed on a polycarbonate sheet having a thickness of 0.6 mm using an ink containing 20 parts by weight of fine spherical particles of polyurethane having an average particle diameter of 18 μm in 100 parts by weight of ink.

  The hardness of the ink film was F, and the elongation at break in the uniaxial direction of the ink film when the film was stretched in the biaxial directions perpendicular to each other at 160 ° C. was 170%.

  There was no printing on the opposite side of the sheet. 150mm wide, 60mm deep, 16mm deep on the bottom of a mold frame with a width of 250mm, a depth of 100mm, a depth of 80mm, and a surrounding vertical wall depth of 5mm, the radius of curvature of the corner between the bottom and vertical vertical walls, and between the vertical vertical walls Prepare a mold with 4mm, approximately rectangular parallelepiped holes with a radius of curvature of 1mm between the top surface and the standing wall, hot plate temperature 190 ° C, mold temperature 70 ° C, and the printing surface of the printing sheet is hot plate The sheet is set in a mold so as to face, 0.4 MPa (gauge) pressure air from the mold, and 0.07 MPa (gauge) vacuum suction of the hot plate, and the sheet is pressed and heated to the hot plate, and then from the hot plate Was drawn at a high pressure of 1.0 MPa (gauge) and vacuum suction of 0.07 MPa (gauge) from the mold.

  There was no trace of vent holes in the hot plate on the printed surface of the resulting three-dimensional polycarbonate sheet, and the ridge line of the aperture was also sharply formed.

  The average elongation in the direction parallel to the standing wall of the standing wall portion (drawing portion) (vertical uniaxial direction) was about 20%.

  Printing was performed on both sides of a polycarbonate sheet with a thickness of 1 mm using ordinary ink, and then printing was performed on both sides with a two-part curable ink (Fig. 8 (b)). The two-part curable ink contained 25 spheres of fine spherical particles having an average particle size of 22 μm in powdered cellulose in 100 parts by weight of the ink. The hardness of the ink film was HB, and the elongation at break in the uniaxial direction of the ink film when stretched in the biaxial direction orthogonal to 160 ° C. was 210%. 100mm wide, 100mm deep, 80mm high, surrounding standing wall depth of 25mm. The bottom of the mold frame is a rectangular parallelepiped with a width of 42mm, a depth of 17mm, and a height of 20mm. The angle between the top and the vertical wall of 17mm in length. The sheet was set in a mold having a convex portion with a radius of curvature of 7 mm, a curvature radius of one corner between the top surface and a standing wall having a length of 42 mm of 6 mm, and a curvature radius of the other corner of 9 mm. The hot plate temperature is 230 ° C, the mold temperature is 70 ° C, the pressure is 0.7 MPa (gauge) from the mold, and the vacuum suction from the hot plate is 0.09 MPa (gauge). Was drawn at 300 ° C. (setting) high-temperature pressure air 1.5 MPa (gauge) and vacuum suction 0.09 MPa (gauge) from the mold.

  The resulting three-dimensional polycarbonate sheet was molded with good appearance without any traces of vent holes in the hot plate. The average elongation in the uniaxial direction of the convex portion squeezed in the biaxial direction (average of the standing wall portion and the top surface portion) was 95%.

  Printing is performed in the same manner as in Example 1 except that the ultraviolet curable ink is used as the ink, the pressure surface from the mold is 0.5 MPa (gauge), with the printed surface of the ultraviolet curable ink in contact with the hot plate, The sheet is pressed and heated to the hot plate by vacuum suction of 0.07MPa (gauge) from the hot plate, and then drawn by 0.06MPa (gauge) vacuum suction from the mold and 1.2MPa (gauge) hot air from the hot plate. I did it. However, the temperature of the hot plate was 195 ° C., and the temperature of the mold was 70 ° C.

  The hardness of the ink film by the ultraviolet curable ink was H, and the uniaxial elongation when the film was stretched biaxially at 160 ° C. was 170%.

  The surface of the automobile instrument panel of the obtained three-dimensional polycarbonate sheet had no traces of vent holes in the hot plate, and the ridge line of the aperture was sharply formed.

  The same two-component curable ink (with polymer particles) as in Example 2 was used, and the design of the control plate of an automobile air conditioner was printed on one side of a polycarbonate sheet having a thickness of 0.4 mm so that it could be backlit. The other side was not printed.

  The hardness of the ink film was F, and the elongation at break in the uniaxial direction when the film was stretched in the biaxial direction perpendicular to each other at 160 ° C. was 170%.

  The mold used for drawing was of the following shape. It was a mold frame having a width and depth of 100 mm, a height of 80 mm, and a surrounding standing wall part having a depth of 10 mm, and having a drawing mold part having the following shape at the center of the bottom surface.

  In other words, there was a protrusion 3 mm high and 45 mm in diameter from the bottom of the mold frame, and then a top surface portion 3 mm high and 29 mm in inner diameter was formed on the circumference from the circumference. The top surface portion had a hole with an inner diameter of 29 mm and a depth of 6 mm. The portion that was not a hole and formed a taper had a very gentle curvature. The corner portion where the tapered portion and the vertical wall portion of the hole intersect had a curvature radius of 0.2 mm.

  The sheet is set in a mold so that the printing surface faces the hot plate, and the sheet is pressed and heated to the hot plate by vacuum suction of 0.2 MPa (gauge) from the mold and 0.05 MPa (gauge) from the hot plate. Then, 0.04 MPa (gauge) vacuum suction from the mold and 0.6 MPa (gauge) hot air from the hot plate were drawn.

  The hot plate temperature was 190 ° C., and the hot plate vent diameter was 0.6 mm.

  The design of the control plate of the air conditioner was installed corresponding to the tapered portion and drawn. The average elongation in the uniaxial direction of the outer and inner standing wall portions (drawing-formed portions) was 15%.

  The obtained three-dimensional sheet had a design in a ring part having a taper, there was no air hole trace in the hot plate, and the corner part was sharp. The sheet was trimmed with a press to obtain a donut-shaped ring having an outer diameter of 45 mm, a bottom hole of 25 mm, a height of 6 mm, and a ring portion having a width of 8 mm.

  The ring was mounted on an injection mold, the mold was closed, and a transparent molten polycarbonate resin was poured into the ring to perform in-mold molding.

  The obtained molded product was a three-dimensional ring having a printing design on the surface and capable of being backlit, and usable for an air conditioner control plate.

FIG. 2 is a perspective view showing a state in which a printed synthetic resin sheet (hereinafter abbreviated as a sheet) is installed on a mold in a hot plate type vacuum / pressure forming machine. It is sectional drawing which shows the state which installed the sheet | seat in the metal mold | die in a hot plate type vacuum pressure forming machine. FIG. 3 is a cross-sectional view showing a state in which the upper part of a sheet placed on a mold is in contact with a hot plate in a hot plate vacuum / pressure forming machine. In a hot plate type vacuum pressure forming machine, it is sectional drawing which shows the state by which the sheet | seat installed in the metal mold | die was crimped | bonded to the hot plate by the vacuum suction from a hot plate, and the pressure air from a metal mold | die. It is sectional drawing which shows the state which draw-draws the sheet | seat in a hot plate type vacuum pressure forming machine. It is sectional drawing which shows the state which is performing the mold opening after drawing a sheet | seat in a hot plate type vacuum pressure forming machine. It is a perspective view which shows the state which takes out the sheet | seat formed by drawing in the hot plate type vacuum pressure forming machine. (a), (b) is sectional drawing of the printed synthetic resin sheet by this invention.

Explanation of symbols

2… Synthetic resin sheet
3… Two-component curable ink
4 ... Normal ink
10 ... Mold frame
11 ... Mold
11a ... Mold vent
12 ... Mold temperature control block
13 ... Mold unit
14 ... Guide pin
15 ... printed synthetic resin sheet
16 ... Guide hole
17 ... Hot plate
17a ... Hot plate vent

Claims (8)

After the printed synthetic resin sheet set on the mold is pressure-bonded to the hot plate and heated by the vacuum suction from the vent hole of the hot plate and the compressed air pressing from the vent hole of the die, In hot plate type vacuum / pressure forming, the sheet is drawn by vacuum suction from the high temperature / pressure supplied from the vent of the hot plate and the vent of the mold,
・ The hot plate has a vent hole diameter of 0.2 mm to 0.7 mm. ・ The high-temperature pressure air blown from the hot plate is 0.3 MPa to 1.5 MPa (gauge). The hot plate temperature is 1700 ° C. or more. When drawing is performed such that the uniaxial elongation when stretching in the biaxial direction is 300% or less on average, or the elongation when stretching only in the uniaxial direction is 2% or more on the average, the printed surface of the sheet is A) The hardness of the ink film when measured by the JIS K5600 method is F or more. (B) The uniaxial rupture elongation of the ink film when the ink film is stretched in the biaxial directions orthogonal to each other at 160 ° C. It is formed of an ink having both the hardness and the elongation characteristics, which does not generate a vent hole mark and is not reduced in the drawability of the synthetic resin sheet by being 140% or more. Synthetic resin sheet.   2. The synthetic resin sheet according to claim 1, wherein the ink is a two-component curable ink.   3. The synthesis according to claim 1 or 2, wherein the ink contains 5 to 30 parts by weight of polymer particles having an average particle diameter of 1 to 35 μ in 100 parts by weight of the ink. Resin sheet.   3. The composition according to claim 1, wherein the ink contains 10 to 20 parts by weight of polymer particles having an average particle diameter of 2 to 20 μ in 100 parts by weight of the ink. Resin sheet.   2. The synthetic resin sheet according to claim 1, wherein the ink is an ultraviolet curable ink.   6. The synthetic resin sheet according to claim 5, wherein the ink contains 5 to 45 parts by weight of polymer particles having an average particle diameter of 1 to 35 microns in both 100 parts of ink.   6. The synthetic resin sheet according to claim 5, wherein 10 to 20 parts by weight of polymer particles having an average particle diameter of 2 to 20 μm are contained in 100 parts by weight of the ink. After the printed synthetic resin sheet set on the mold is pressure-bonded to the hot plate and heated by vacuum suction from the hot plate vent and pressure air pressure from the die vent, the above-mentioned In hot plate vacuum / pressure forming where the sheet is drawn by high-temperature pressure air ejected from the vent hole of the hot plate and vacuum suction from the vent hole of the mold. The vent hole diameter of the hot plate is 0.2 mm to 0.7 mm.・ High-temperature compressed air ejected from the hot plate is 0.3 MPa to 1.5 MPa (gauge) ・ Hot plate temperature is 170 ° C. or more ・ Elongation in the uniaxial direction when the sheet is stretched in the biaxial directions perpendicular to each other Of the ink film when the printing surface of the sheet is measured by (A) JIS K5600 method when drawing is performed such that the average elongation is 300% or less or the elongation when stretching only in the uniaxial direction is 2% or more Hardness is F or more (B) When the ink film is stretched in biaxial directions perpendicular to each other at 160 ° C., the elongation at break in the uniaxial direction of the ink film is 140% or more, so that no air hole marks are generated and the drawability of the sheet is improved. A synthetic resin sheet formed of an ink having both the hardness and the elongation property that does not decrease is set on a mold, and the sheet is pressed against a hot plate to vacuum suction and gold from the vent of the hot plate. After the printing sheet is heated by pressing the air pressure from the mold air hole, the sheet is drawn by high-temperature pressure air ejected from the air hole of the hot plate and vacuum suction from the air hole of the mold. A method for drawing a synthetic resin sheet.