JP2013173364A - Method and device for manufacturing sheet having fine shape transferred thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a sheet having fine shapes transferred thereon used for imprinting the fine shapes of texture of an imprint mold on at least one face of a sheet-like material, in which, without causing transfer defects, trapped air between the imprint mold and the sheet-like material is removed out of the imprinting surface upon forming, even in the case when the imprinting process is carried out at least one face of the sheet-like material with a large area, and a sheet having a surface on which the fine texture are desirably formed, is manufactured with high efficiency.SOLUTION: A method for manufacturing a sheet having a fine shape transferred thereon comprises the steps of: placing a sheet-like material 5 between an imprint mold 8 having an imprinting surface provided with the fine shapes of texture and an intermediate base 6; and pressing the imprint mold and the intermediate base in a direction toward the sheet-like material by a pair of pressing plates so that the fine shapes of texture are imprinted on the sheet-like material.The sheet-like material is pressed such that, when pressing force of the pressing plates is maximized, a portion where the imprinting pressure has a minimum value is not present in the imprinting surface.

Description

  The present invention relates to an apparatus for manufacturing a sheet having a fine three-dimensional shape on a surface onto which a fine shape is transferred.

  As a method of forming a three-dimensional shape such as fine irregularities on the surface of a resin sheet or the like, the resin sheet and an imprint mold having fine irregularities are heated and pressed to form the three-dimensional shape of the irregularities. There is known a method of transferring the toner. However, this method has a problem in that air is caught between the resin sheet and the imprint mold, and a fine three-dimensional shape is not completely transferred, resulting in a transfer failure.

  As a means for preventing this, a method is known in which a shaping surface is placed in a chamber, the shaping surface is evacuated, and shaping is performed. (Patent Document 2) However, in Patent Document 2, it is difficult to apply to a manufacturing method in which a roll-shaped continuous resin sheet is fed from an unwinding device into a shaping device. It takes a long time, and the cycle time becomes long, and there is a problem that the productivity is deteriorated.

As another method for preventing air jamming, other than Patent Document 2, the transfer plate is bent so as to protrude with respect to the resin plate by a holding member using springs having different repulsive forces at the start of contact of the pressure plate. A method is known in which molding is performed while excluding air from the vicinity of the center of the transfer surface (see Patent Document 3). However, in Patent Document 3, the holding member is installed in the non-transfer portion of the transfer plate for the purpose of making the pressure on the transfer surface uniform when the press pressure is maximized. In this configuration, when the transfer surface becomes a large area, the gap between the holding members is widened, so that the transfer surface is slackened, and there is a problem in that the slack portion causes air jamming during molding. Furthermore, since the elastic force difference is provided in the holding member, it is predicted that there is a pressure distribution on the transfer surface and there is a minimum pressure portion in the holding member gap. For this reason, there is a problem that a part of the air bitten in the slack portion remains in the minimum pressure portion, resulting in transfer failure. Even if some of the entrained air is excluded at the time of molding, the pressure distribution that actively eliminates air is not given to the shaping surface, so it is necessary to press for a long time to eliminate air , There is a problem that the cycle time becomes long and the productivity deteriorates.
JP 2005-199455 A JP-A-5-060920 JP 2006-035573 A

  In view of the above-described points, the object of the present invention is to form a sheet-shaped substrate having a large area in a method for producing a fine-shaped transfer sheet in which a fine uneven shape of an imprint mold is formed on the surface of a sheet-shaped substrate. Even in the case, the air entrained between the imprint mold and the sheet-like base material is excluded from the shaping surface during molding, and transfer irregularities are not generated, and the desired fine uneven shape is formed on the surface. It is to provide a production apparatus for producing a sheet with high efficiency.

(1) A method for producing a fine shape transfer sheet that achieves the above-described object comprises the following methods.
-A sheet-like base material is installed between an imprint mold having a shaping surface having a fine concavo-convex shape and an intermediate base material, and the imprint mold and the intermediate base material are connected to the sheet-like base by a pair of pressure plates. A method for producing a fine shape transfer sheet, in which a fine uneven shape is formed on the surface of the sheet-like substrate by pressing in the material direction,
When the pressing force of the pressure plate becomes maximum, there is a shaping pressure difference in the shaping surface, and there is a maximum shaping pressure portion in the shaping surface, and the shaping pressure is A method for producing a fine shape transfer sheet, in which a portion having a minimum value is pressurized so that it does not exist in the shaping surface.

Moreover, the manufacturing method of a fine shape transfer sheet preferably also performs the following method.
-The concave and convex shapes of the imprint mold are a plurality of grooves arranged in parallel, and when the pressing force of the pressure plate is maximized, there is a shaping pressure difference along the longitudinal direction of the grooves. Pressurizing so that there is no portion where the maximum shaping pressure portion exists and the shaping pressure takes a minimum value,
-Pressurizing so that the absolute value of the shaping pressure gradient monotonously increases along the direction in which the shaping pressure decreases from the maximum shaping pressure portion;
The intermediate substrate has cushioning properties,
The compression elastic modulus of the intermediate base material when the pressure applied to the pressure plate reaches a maximum is 0.1 MPa to 200 MPa over the entire shaping surface, and the sheet-like base material and the inboard before shaping Heating the print mold.

(2) The 1st imprint mold which achieves the objective mentioned above consists of the following structures.
A plate-shaped imprint mold for transferring a fine uneven shape to a sheet-like substrate, having a fine uneven shape shaping surface, having a thickness change in the shaping surface, and in the shaping surface An imprint mold having a maximum thickness portion and having no minimum thickness within the shaping surface.

The first imprint mold preferably also has the following configuration: a plurality of grooves in which the concave and convex shapes of the fine unevenness are arranged in parallel, and the thickness change is along the longitudinal direction of the grooves Being
The absolute value of the amount of change in thickness per unit length of the imprint mold is monotonically increasing from the maximum thickness portion along a thickness gradient.

(3) The 2nd imprint mold which achieves the objective mentioned above consists of the following structures.
A plate-shaped imprint mold for transferring a fine uneven shape to a sheet-like substrate, having a fine uneven shape shaped surface, the entire imprint mold being curved, and the center of curvature of the curve being the center of curvature Imprint mold that exists on the opposite side of the shaping surface.

(4) The first fine shape transfer sheet manufacturing apparatus that achieves the above-described object has the following configuration.
・ Imprint mold,
An intermediate substrate;
A pair of pressure plates arranged to sandwich the imprint mold and the intermediate substrate from both sides; and
An apparatus for producing a fine shape transfer sheet, comprising at least a pressing means for pressing the imprint mold, the intermediate substrate, and the pair of pressing plates.

(5) The second fine shape transfer sheet manufacturing apparatus of the present invention that achieves the above-described object has the following configuration.
An imprint mold having a shaping surface composed of fine irregularities;
An intermediate substrate;
A pair of pressure plates arranged to sandwich the imprint mold and the intermediate substrate from both sides; and
A pressurizing means for pressurizing the imprint mold, the intermediate substrate and the pair of pressure plates;
And at least a convex plate installed on the surface on the pressure direction side of at least one pressure plate of the pair of pressure plates,
An apparatus for manufacturing a fine shape transfer sheet, wherein the plate has a thickness distribution, has a maximum thickness portion in the plane of the plate, and does not have a portion having a minimum thickness in the plane.

The second fine shape transfer sheet manufacturing apparatus of the present invention preferably also has the following configuration.
-The concave and convex shapes of the imprint mold are a plurality of grooves arranged in parallel, and the plate is installed so that the thickness change of the plate is along the longitudinal direction of the grooves.
The absolute value of the amount of change in thickness per unit length of the plate is monotonously increasing along the thickness gradient from the maximum thickness portion;
The imprint mold is gripped in close contact with the plate, and the shaping surface of the imprint mold has the same curved profile as the plate.

In addition, the first and second fine shape transfer sheet manufacturing apparatuses of the present invention preferably also have the following configuration.
The intermediate substrate has cushioning properties,
The intermediate base material having cushioning properties is (a) a polymer material having bubbles inside, (b) a composite material in which a rubber layer and a fiber layer are laminated, and (c) a composite in which the fiber layer is impregnated with rubber. Consisting of at least one selected from the group consisting of materials,
The intermediate base material has a compression elastic modulus of 0.1 MPa to 200 MPa over the entire shaping surface when the pressing force on the shaping surface becomes maximum.
A means for heating the sheet-like base material and the imprint mold is provided.

  According to the apparatus for producing a fine concavo-convex shape transfer sheet of the present invention, residual air entrained between a sheet-like substrate and an imprint mold is applied during forming by utilizing a forming pressure difference in the forming surface. By eliminating out of the form surface, air-engagement failure is eliminated, and a uniform and highly accurate transfer molding state can be obtained.

  By curving the shaping surface of the imprint mold by the imprint mold, a desired pressure distribution can be easily obtained, air-engagement failure can be eliminated, and productivity can be improved.

  Hereinafter, the manufacturing method and manufacturing apparatus of the fine shape transfer sheet will be described in more detail with reference to the drawings.

  The method for producing a fine shape transfer sheet is a method in which a sheet-like base material is installed between an imprint mold having a shaping surface having a fine concavo-convex shape and an intermediate base material, and the imprint mold and the intermediate member are formed by a pair of pressure plates. A method for producing a fine shape transfer sheet, wherein the fine uneven shape is formed on the surface of the sheet-like base material by pressurizing the base material in the direction of the sheet-like base material, and the pressure applied to the entire shaping surface When the pressure reaches the maximum, there is a shaping pressure difference in the shaping surface, a maximum shaping pressure part exists in a part of the shaping surface, and the shaping pressure takes a minimum value. It is a manufacturing method characterized by pressurizing so that a part may not exist in the shaping surface.

  Here, “when the applied pressure is maximized” refers to the time when the pressing force of the press machine that forms the sheet-like substrate on the imprint mold by the pair of pressure plates is maximized.

  The “part of the shaping surface” may be not only one point in the shaping surface but also a continuous linear shape.

  Further, the “fine concavo-convex shape” means a shape in which a convex shape having a height of 10 nm to 1 mm is periodically repeated with a convex shape having a pitch of 10 μm to 1 mm, more preferably 1 μm to 100 μm in height. For example, a plurality of triangular grooves extending linearly as shown in FIG. 1 are arranged in stripes. FIG. 1 shows a groove having a triangular cross section. However, the groove is not limited to a triangular shape, and a semicircular shape or a semielliptical shape can also be used in the present invention. Furthermore, the groove does not have to be a straight line, and may be a curved stripe pattern. The “fine concavo-convex shape” includes a shape having a two-dimensional pattern represented by an embossed shape as shown in FIG. Although FIG. 2 shows an embossed shape having a semicircular convex shape, other convex shapes such as a cone and a rectangular parallelepiped can also be used in the present invention.

Further, “the shaping pressure takes a minimum value” means that when the shaping surface is divided into a grid with a side length of 10 mm, the average shaping pressure in an arbitrary grid is P, and the grid touches this grid. when One of the lattice of the average imprinting pressure and P ₁ to P _8, respectively, all P ≦ P _X refers that holds for x (here x is a natural number of 1-8.). In other words, the "site of imprinting pressure takes the minimum value is not present in the vehicle surface", is that the grating as P ≦ P _X is satisfied is not present in the vehicle surface for all x. In other words, there is at least one adjacent lattice satisfying the average shaping pressure P _X <P for all the lattices in the shaping surface. If the shaping pressure distribution measured at intervals of 10 mm does not take a minimum value, the object of the present invention can be sufficiently achieved.

  Next, the example of the suitable shaping pressure distribution of this invention is shown in FIG. A broken line a shown in the figure is a line in the shaping surface, and has a maximum shaping pressure portion on this line. Further, the shaping pressure monotonously decreases from the maximum shaping pressure portion along the x direction without taking a minimum value. FIG. 4 shows another example of the shaping pressure distribution suitable for the present invention. In FIG. 4, there is a maximum pressure portion along one end b in the x direction of the shaping surface, and the shaping pressure takes a minimum value from the maximum shaping pressure portion toward the other end along the x direction. It is decreasing monotonically without. By providing such a shaping pressure gradient, even when air biting occurs during shaping, the air moves to the side where the shaping pressure is low due to the shaping pressure difference around the air. That is, in the case of FIG. 1, the remaining air is discharged along the shaping pressure gradient from the broken line a along the x-axis direction and in FIG. 2 from one end to the other end of the shaping surface in the x-axis direction. Further, this discharge force increases in proportion to the shaping pressure difference around the air. If there is a minimum value of pressure in the shaping surface, this location becomes an air reservoir and causes transfer failure.

As shown in FIG. 1, in particular, when using an imprint mold in which the concave and convex shape is a groove extending in parallel in a straight line or curved line, and a plurality of grooves are arranged in parallel in a stripe shape, In addition to the fact that there is no minimum value in the shaping surface, there is a shaping pressure difference along the longitudinal direction of the groove, there is a maximum shaping pressure section, and the shaping pressure is minimal. It is preferable to pressurize so as not to have a value. This is because the air trapped in the groove and the sheet-like base material is difficult to move to other grooves by jumping over the convex part of the fine uneven shape, so forming the shaping pressure distribution along the groove and eliminating the air This is because it is efficient. In this case, “having the minimum value of the shaping pressure along the longitudinal direction of the groove” means that the 10 mm square lattice is divided so as to be aligned along the longitudinal direction of the groove, and the average shaping pressure of an arbitrary lattice is determined. P, when the average pressure of two lattices adjacent to the lattice along the longitudinal direction of the groove is defined as P ₁ and P ₂ , P ≦ P ₁ and P ≦ P ₂ are satisfied. In other words, “no minimum value of the shaping pressure along the longitudinal direction of the groove” means that there is no lattice along the longitudinal direction of the groove that satisfies P ≦ P ₁ and P ≦ P _2. is there. In other words, there is at least one adjacent lattice satisfying P ₁ <P or P ₂ <P for all lattices along the longitudinal direction of the groove.

  Furthermore, it is preferable that the absolute value of the change amount of the shaping pressure is monotonously increased along the shaping pressure gradient from the maximum shaping pressure portion when the pressing force of the pressure plate becomes maximum. FIG. 5 shows a view of the shaping surface pressure distribution from the front direction (the negative direction of the y-axis) in FIG. 3, and FIG. 6 shows the shaping pressure change amount from the maximum shaping pressure portion along the shaping pressure gradient. The figure which looked at the example of the pressure distribution which has the area | region c where the absolute value of is not increasing monotonously from the same direction is shown. FIG. 5 shows a more preferable shaping pressure distribution in the present invention. Specifically, a parabola, a circular arc, a catenary curve, or the like can be used, but not limited to these, the maximum shaping pressure portion changes to the shaping pressure gradient. It is only necessary to have a profile in which the absolute value of the shaping pressure change amount increases monotonously along the line.

  In FIG. 5, since the shaping pressure gradient becomes steep from the shaping pressure maximum portion at the center of the shaping surface toward the end portion, the discharge force increases as the air moves to the end portion. As a result, the air discharge speed increases toward the end of the shaping surface, and air can be sufficiently eliminated even with a short pressurization. That is, the molding cycle can be accelerated, leading to an improvement in productivity.

  If the amount of change in the shaping pressure along the shaping pressure gradient decreases monotonously as in the area c in FIG. 6, the shaping pressure gradient becomes gentle in this area. The difference becomes smaller and the discharge power decreases. Even in this case, air can be discharged. However, since it takes time to discharge air, it is preferable that the shaping pressure distribution shown in FIG.

  The shaping pressure distribution suitable for the present invention described above is that the imprint mold has a curved profile that is convex on the shaping surface side, and is imprinted with the sheet-like substrate via the intermediate substrate by the pressure plate. It can be obtained by pressing the print mold. First, a specific method for giving a curved profile to the shaping surface is shown in FIGS.

FIG. 7 shows an example of an imprint mold having a thickness distribution. The thickness of the imprint mold is set so that the maximum value of the thickness is obtained in a part of the shaping surface and the minimum value of the thickness is not present in the shaping surface. More preferably, the absolute value of the amount of change in thickness per unit length of the imprint mold is set so as to monotonously increase from the maximum thickness portion along the thickness gradient. By providing such a thickness distribution and giving a curved profile to the shaping surface, a pressure distribution suitable for the present invention described above can be obtained during shaping. Here, “having a minimum value of thickness” means that when the shaped surface is divided into a lattice shape with a side length of 10 mm, the average thickness in an arbitrary lattice is T, and the eight lattices in contact with the lattice are When the average thickness is T _{1 to} T _8, it means that T ≦ T _X is satisfied for all x (where x is a natural number of 1 to 8). That is, the "no minimum value in thickness within the shaping surface", is that the grating as T ≦ T _X is satisfied is not present in the vehicle surface for all x. In other words, there is at least one adjacent lattice that satisfies the average thickness T _X <T for all the lattices in the shaping surface. The thickness difference between the maximum thickness portion and the minimum thickness portion is preferably in the range of 1 μm to 500 μm, more preferably 1 μm to 200 μm. If the thickness difference is less than 1 μm, a sufficient shaping pressure gradient cannot be obtained during shaping, and air may not be discharged. On the other hand, when the thickness difference is larger than 500 μm, a transfer failure may occur because a sufficient molding pressure is not applied to a thin portion.

  A method for manufacturing the imprint mold shown in FIG. 7 will be described. First, in order to give a desired curved profile to the shaping surface side of the molding material described later, curved surface data is input to an NC processing machine capable of three-dimensional processing. Next, using a cutting tool having the same shape as the cross-section of the fine concavo-convex shape, the fine concavo-convex shape is imparted to the shaped surface by cutting with the NC processing machine along the profile.

  In FIG. 7, the curved profile is given only to the shaping surface, but the curved profile may be given to the opposite surface of the shaping surface or both. In this case, the profile of the forming surface opposite surface is first processed by the NC processing machine described above, and then the mold material is set on the stage of the NC processing machine via a jig so that the forming surface can be processed. The shaped surface may be processed into a curved shape and a fine concavo-convex shape by an NC processing machine by the method described above. The jig is used because the opposite side of the shaped surface that has already been processed is a curved surface and cannot be directly installed on the stage of the NC processing machine with the surface as the processing reference.

  FIG. 8 shows an example of an imprint mold in which an imprint mold having a constant thickness is curved so that the center of curvature exists on the side opposite to the shaping surface, and the shaping surface has a curved profile. When using this imprint mold to form a fine uneven shape on a sheet-like substrate, the imprint mold that is curved when pressure is applied becomes a flat plate, and there is a repulsive force that tries to return to the original curved shape. The desired pressure distribution is obtained by this repulsive force. The curvature radius is preferably 120 m to 60000 m, more preferably 300 m to 60000 m. If the radius of curvature is less than 120 m, the shaping pressure necessary for molding cannot be obtained over the entire shaping surface, which may result in transfer failure. If the radius of curvature is larger than 60000 m, a shaping pressure gradient sufficient to discharge air may not be obtained.

  The imprint mold shown in FIG. 8 can be manufactured by using an NC processing machine and a machining tool having the same shape as the cross section of the fine uneven shape, like the imprint mold having the thickness distribution shown in FIG.

  FIG. 9 is a view showing an example in which an imprint mold is placed on a plate 7 having a thickness distribution and the imprint mold opposite surface of the imprint mold is closely attached to the plate 7. This plate takes a maximum value of the thickness in a part of the surface and does not have a minimum value of the thickness in the surface. More preferably, the absolute value of the amount of change in thickness is monotonously increased along the thickness gradient from the maximum thickness portion. The surface opposite to the shaping surface of the imprint mold is brought into close contact with and gripped on the plate, thereby giving the imprint mold shaping surface a curved profile. Here, “having no minimum value of thickness in the plane” has the same meaning as “having no minimum value of thickness in the shaping surface” in the above-described imprint mold. The thickness difference between the maximum thickness portion and the minimum thickness portion of the plate is preferably in the range of 1 μm to 500 μm, more preferably 1 μm to 200 μm. When the thickness difference is smaller than 1 μm, a sufficient shaping pressure gradient cannot be obtained, and air may not be discharged. On the other hand, when the thickness difference is larger than 500 μm, a transfer failure may occur because a sufficient forming pressure is not applied to a thin portion. The plate does not necessarily have to be installed on the surface opposite to the imprint mold surface, but it can be formed on the sheet-like substrate side of the pressure plate opposite the pressure plate on which the imprint mold is installed. As long as a desired shaping pressure distribution can be given to the surface, it may be installed anywhere.

  The imprint mold material described above may be any material that can provide the desired strength during pressing, pattern processing accuracy, and sheet releasability. For example, metallic materials including stainless steel, nickel, copper, etc., silicone, glass Ceramics, resins, or their surfaces coated with an organic film for improving releasability are preferably used. The fine pattern of the imprint mold is formed corresponding to a fine uneven pattern desired to be applied to the sheet surface.

  In addition, the manufacturing method of the fine shape transfer sheet forms a curved profile on the shaping surface, presses the imprint mold and the sheet-like substrate using a pair of pressure plates, and forms the intermediate substrate when shaping. It is indispensable. Without an intermediate substrate, the forming pressure is applied only to the apex of the curve, so that not only a desired forming pressure distribution can be obtained but also a transfer failure occurs. In order to prevent this, an intermediate base material is installed, and the intermediate base material is deformed during pressing to disperse the pressing force over the entire shaping surface, thereby obtaining the shaping pressure distribution suitable for the present invention described above.

  Moreover, it is more preferable that the intermediate substrate has cushioning properties. Here, “having cushioning properties” means that when the applied pressure is maximized, it can be deformed following the curved shape of the shaping surface of the imprint mold, and the imprint mold, sheet-like substrate, intermediate substrate itself It means that it has elasticity and flexibility that can absorb the thickness unevenness and can generate a repulsive force according to the amount of deformation. Due to the elasticity and flexibility, the imprint mold and the sheet-like substrate can be brought into contact with no gap, and the intermediate substrate and the sheet-like substrate can also be brought into contact with no gap. Furthermore, from the viewpoint of productivity, those that do not change in rebound characteristics even when used repeatedly are preferable.

  FIG. 10 shows an example of using an intermediate base material suitable for the present invention. 10, 3 is an upper pressure plate, 4 is a lower pressure plate, 5 is a sheet-like base material, 6 is an intermediate base material, 8 is an imprint mold, 8a is an imprint mold shaping surface, and FIG. ) Shows a state before shaping, and FIG. 10B shows a state during shaping. The intermediate base material 6 in a flat plate state before pressurization is deformed according to the curved profile of the imprint mold shaping surface 8a during pressurization. In particular, when the intermediate base material has cushioning properties, the intermediate base material easily deforms following the curved shape of the shaping surface of the imprint mold. The shaping pressure is determined by the relationship between the deformation amount of the intermediate base material 6 and the compression elastic modulus, and the shaping pressure is larger as the deformation amount is larger. In the state during shaping shown in FIG. 10 (b), the deformation amount of the intermediate base material 6 is maximized at the central portion of the imprint mold shaping surface 8a and decreases toward the end portion. This indicates that the shaping pressure is maximized at the center of the shaping surface, and the shaping pressure is monotonically decreasing toward the end.

  Furthermore, since the absolute value of the thickness change amount of the shaping surface of the imprint mold shaping surface 8a is set so as to increase monotonically along the shaping gradient from the maximum thickness portion, the amount of change in the shaping pressure Is also monotonously decreasing from the maximum shaping pressure portion along the shaping pressure gradient, and the shaping pressure distribution suitable for the present invention described above is realized.

  The compression modulus of the intermediate base material is preferably 0.1 MPa to 200 MPa, more preferably 0.1 MPa to 50 MPa. If the compression modulus is lower than 0.1 MPa, the shaping pressure difference in the shaping surface becomes small, and air may not be excluded. Further, the time required for the removal becomes longer, and the productivity is deteriorated. Further, if the compression elastic modulus is larger than 200 MPa, the forming pressure difference in the forming surface becomes too large, so that a sufficient forming pressure cannot be obtained at a portion where the forming pressure is low, resulting in transfer failure. is there.

  The thickness of the intermediate substrate is preferably in the range of 0.1 mm to 50 mm, more preferably 0.3 mm to 30 mm. If the thickness is less than 0.1 mm, the amount of deformation of the intermediate substrate becomes small, the cushioning property becomes poor, the curved profile of the imprint mold cannot be sufficiently followed, and transfer failure may occur. Further, if the thickness is greater than 50 mm, the amount of compressive deformation of the intermediate base material is large at the time of pressurization, and it is necessary to extend the stroke distance of the press, which is inefficient due to an increase in equipment cost and a decrease in manufacturing cycle. .

  Specifically, the intermediate base material having such characteristics is natural rubber, isoprene rubber, styrene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, silicone rubber, fluorine rubber, ethylene propylene rubber, urethane rubber, nitrile rubber. Rubbers such as butyl rubber are preferred. Furthermore, a polymer material having sufficient heat resistance at the (glass transition point + 50 ° C.) of the sheet-like substrate is preferable. Specifically, silicone rubber and fluororubber are more preferable.

  Furthermore, since the intermediate base material has the cushioning property described above, it is preferable that the intermediate base material be accompanied by a volume change when deformed under stress. This is because when the shaping surface has a large area, when the intermediate substrate compressively deforms along the curved shape of the imprint mold, there is no place for the volume of deformation, and as a result, the apparent elastic modulus This is because it becomes very large and it becomes difficult to follow the curved shape. For this reason, it is preferable that the intermediate substrate has volume changeability. As a method for imparting volume changeability to the intermediate substrate, (a) a polymer material having bubbles inside such as sponge, preferably the polymer is made of resin or rubber, (b) volume change with rubber A composite material obtained by laminating layers, (c) a composite material obtained by impregnating a volume change layer with rubber, and the like can be preferably used. In addition, any combination of the above (a) to (c) can be suitably used in the present invention. As the volume change layer, a knitted or woven fiber, a non-woven fabric or the like, or a laminate of these can be suitably used. When the intermediate substrate is composed of these members, preferred cushioning properties can be easily obtained.

  However, when these rubber materials and rubber composites are directly used as an intermediate base material, the friction coefficient with the sheet-like base material is large, and the slipperiness may be deteriorated. In this state, if slack occurs in the sheet-like base material or intermediate base material before molding, even if molding pressure is applied, this slack is not eliminated due to friction between the intermediate base material and the sheet-like base material, It causes transfer unevenness. In order to prevent this, embossing is performed on the intermediate base material, the contact area with the sheet-like base material is lowered, the friction coefficient is lowered, and the sheet has good slipperiness with the sheet-like base material such as fluororesin and polyester resin. Is preferably installed on the surface of the intermediate substrate facing the sheet-like substrate. Furthermore, the intermediate substrate does not need to be one type, and the above rubbers, fluororesins, polyester resins, and the like can be used in any combination.

  There are a method of pressing the pressure-sensitive paper and a method of pressing a sheet that is plastically deformed according to the pressure and measuring the thickness change after pressing to confirm the shaping pressure distribution obtained by the above configuration.

  The above-described specific method of the present invention can be performed by the apparatus for producing a fine shape transfer sheet of the present invention described below. That is, the imprint mold of the present invention, / intermediate base material, / a pair of pressure plates arranged so as to sandwich the imprint mold and the intermediate base material from both sides, the imprint mold, An apparatus for producing a fine shape transfer sheet comprising at least an intermediate substrate and a pressing means for pressing the pair of pressing plates.

  In addition, another specific method of the present invention described above can be performed by the apparatus for manufacturing a fine shape transfer sheet of the present invention described below. That is, an imprint mold having a shaping surface of fine unevenness, / an intermediate substrate, / a pressure plate arranged so as to sandwich the imprint mold and the intermediate substrate from both sides, A press mold that pressurizes the print mold, the intermediate substrate, and the pair of pressure plates; and / or a convex plate that is disposed on a surface on the pressure direction side of at least one pressure plate of the pair of pressure plates. An apparatus for producing a fine shape transfer sheet comprising at least the plate, having a thickness distribution, having a maximum thickness portion in the plane of the plate, and no portion having a minimum thickness in the plane.

  FIG. 11 is a schematic front view showing an example of an embodiment of the apparatus for producing a fine shape transfer sheet of the present invention suitably used for carrying out the method for producing a fine shape transfer sheet.

  FIG. 11A shows a manufacturing apparatus for a fine shape transfer sheet in which a thickness distribution is given to the imprint mold to give a curved shape to the shaping surface, and FIG. 11B shows a plate to which the thickness distribution is given is installed on the pressure plate. By this, it is the manufacturing apparatus of the fine shape transfer sheet which provided the curved shape to the shaping surface of the imprint mold. In FIG. 11, 1 is a fine shape transfer sheet manufacturing apparatus, 2 is a press apparatus, 3 is an upper pressure plate, 4 is a lower pressure plate, 5 is a sheet-like base material, 6 is an intermediate base material, 7 is a plate, and 8 is an in-plate. A print mold shaping surface 8a is an imprint mold shaping surface.

  In FIG. 11B, a plate having a thickness distribution is placed between the imprint mold and the lower pressure plate. However, if the desired shaping pressure distribution described above can be applied to the shaping surface, the upper pressure plate It may be installed between the intermediate substrate and the like.

  The press is connected to a hydraulic pump (not shown) and an oil tank. The hydraulic pump controls the up / down operation of the upper pressurizing plate 3 and the applied pressure. In this embodiment, a hydraulic press cylinder is applied, but any mechanism can be used as long as it can control the applied pressure.

  The press pressure range is preferably controllable in the range of 0.1 MPa to 20 MPa, more preferably 1 MPa and in the range of 10 MPa. When the pressing pressure is less than 0.1 MPa, a pressure sufficient to transfer the fine uneven shape may not be obtained. If the press pressure is greater than 20 MPa, the facilities will be excessive and productivity will deteriorate.

Further, the imprint mold used in the present invention is provided with a heat medium circuit for temperature control, and a heat medium or a refrigerant is supplied from a heat medium temperature control pump not shown in the drawing, and the imprint mold is heated. And cooling is possible. The heating medium preferably has a Reynolds number in the tube of 1.0 × 10 ^{4 to} 12 × 10 ⁴ so that water heated to 100 ° C. or higher can be circulated to efficiently transfer heat.

  The sheet-like substrate applied to the method and the apparatus preferably has a glass transition temperature Tg of 40 to 180 ° C, more preferably 50 to 160 ° C, and most preferably 50 to 120 ° C. This is a sheet mainly composed of a plastic resin. When the glass transition temperature Tg is lower than 40 ° C., the heat resistance of the molded product is lowered, and the shape changes with time. Further, if Tg exceeds 180 ° C., the molding temperature must be increased, resulting in inefficiency in energy, and volume fluctuation during heating and cooling of the sheet increases, and the sheet bites into the imprint mold. However, even if it can be released, it is not preferable because the transfer accuracy of the pattern may be reduced or the pattern may be partially broken to cause a defect.

  Specifically, the sheet-like base material mainly composed of the thermoplastic resin applied to the present invention is preferably a polyester-based resin such as polyethylene terephthalate, polyethylene-2, 6-naphthalate, polypropylene terephthalate, polybutylene terephthalate, or polyethylene. Polyolefin resins such as polystyrene, polypropylene, polyisobutylene, polybutene, polymethylpentene, polyamide resins, polyimide resins, polyether resins, polyester amide resins, polyether ester resins, acrylic resins, polyurethane resins, It is made of polycarbonate resin or polyvinyl chloride resin. Among these, there are various types of monomers to be copolymerized, and it is easy to adjust the physical properties of the materials, and in particular, polyester resins, polyolefin resins, polyamide resins, acrylic resins, or mixtures thereof. It is preferable that it is mainly formed from a thermoplastic resin selected from the above, and it is more preferable that the above-mentioned thermoplastic resin comprises 50% by weight or more.

  The sheet-like base material applied to the present invention may be a sheet made of the above-mentioned resin alone or a laminate made of a plurality of resin layers. In this case, compared with a single sheet, surface characteristics such as slipperiness and friction resistance, mechanical strength, and heat resistance can be imparted. Thus, when it is a laminate composed of a plurality of resin layers, it is preferable that the entire sheet satisfies the above-mentioned requirements, but even if the entire sheet does not satisfy the above-mentioned requirements, there is a layer that satisfies at least the above-mentioned requirements. If it is formed on the surface layer, the surface can be easily formed.

  Moreover, as preferable thickness (thickness, film thickness) of the sheet-like base material applied to this invention, if the sheet | seat wound by roll shape is shape | molded intermittently, it is the range of 0.01-1 mm. It is preferable. If the thickness is less than 0.01 mm, the thickness is not sufficient for molding. If the thickness exceeds 1 mm, the sheet is generally difficult to convey due to the rigidity of the sheet. In addition, if the sheet is formed intermittently, the thickness is 0.3 mm or more, more preferably 1 mm or more in order to suppress the deflection during conveyance.

  FIG. 12 is a schematic front view schematically showing a state when the pressure applied to the pressure plate becomes maximum using the apparatus for manufacturing a fine shape transfer sheet of the present invention shown in FIG. As described above, the intermediate base material is deformed during shaping according to the curved profile of the imprint mold shaping surface, whereby a desired shaping pressure distribution is obtained.

  The method and apparatus for forming the thermoplastic resin as a sheet-like base material by heating the imprint mold and the sheet-like base material have been described above, but the present invention is a known photocurable resin sheet-like base material. The present invention can also be applied to a manufacturing method and a manufacturing apparatus for a fine shape transfer sheet.

  Hereinafter, the specific configuration and effects of the method and the apparatus will be described based on examples.

  In the following examples, a fine shape transfer sheet was manufactured by applying a fine shape with an imprint mold, a pressing device, and processing conditions having the specifications shown in (1) to (10). .

[Example 1]
(1) Imprint mold size: 500 mm (sheet width direction) x 800 mm (sheet running direction) x 30 mm (thickness)
(2) Imprint mold material: Copper (3) Fine shape of imprint mold shaping surface: groove having a pitch of 50 μm, a convex width of 25 μm, and a convex part height of 50 μm and a semi-elliptical cross section when viewed from the sheet running direction Then, the groove was used in a stripe shape.
(4) Press device: It can pressurize up to 3000 kN, and pressurization is performed by a hydraulic pump.
(5) Temperature control: Imprint mold is provided with a temperature control heat medium path, heated by water at 125 ° C., cooled by water at 50 ° C. (6) Sheet-like substrate: made of polyethylene terephthalate, thickness of 120 μm The width is 520 mm.
(7) Intermediate base material: A smooth film made of silicon rubber having a thickness of 300 μm and a polyester-based resin having a thickness of 200 μm was superposed and adhered to the upper pressure plate. At this time, they were superposed in the order in which the smooth film was in contact with the sheet-like substrate.
(8) Imprint mold installation method: A convex plate shown in FIG. 13 (a) was installed under the imprint mold, and the opposite side of the imprint mold surface was fixed to the plate.
(9) A film whose amount of plastic deformation changes according to pressure was pressed, and the thickness of the film after pressing was measured at intervals of 10 mm. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the pressure distribution in the longitudinal direction of the groove was examined, the pressure distribution shown in FIG. 13B was obtained. That is, there was a maximum pressure portion at the center of the shaping surface, and there was no minimum pressure within the shaping surface, but the amount of pressure decrease along the pressure gradient did not increase monotonically.
(10) Using the above apparatus, molding was performed as follows. A resin sheet is placed on the imprint mold in advance. Next, temperature-controlled water is passed through the imprint mold and heated until the imprint mold temperature reaches 105 ° C., and then the upper pressure plate attached with the intermediate substrate is lowered to start sheet pressing. The press was performed at 1700 kN for 3 seconds. During the press, the flow of temperature-controlled water is stopped. Then, cooling water is poured into the imprint mold while the press is continued. When the imprint mold temperature reaches 70 ° C., the cooling is stopped and the press is released. Thereafter, the sheet is released from the imprint mold.
The above operation was repeated to produce 10 molded sheets. As a result of visual evaluation of the molding surface, good transfer was obtained in an area of 95% of the molding surface, but slight air biting and transfer failure occurred in an area of 5%.

[Example 2]
Ten molded sheets were prepared in the same manner as in Example 1 except that the pressing time with the pressure plate was 15 seconds. As a result of visual evaluation of the molding surface, there was obtained a molding sheet that was uniformly transferred without air entrainment or transfer failure.

Example 3
(1) Imprint mold size: Same as Example 1.
(2) Imprint mold material: the same as in Example 1.
(3) Fine shape: same as Example 1.
(4) Press device: same as Example 1.
(5) Temperature control: Same as Example 1.
(6) Sheet-like substrate: the same as in Example 1.
(7) Intermediate substrate: the same as in Example 1.
(8) Imprint mold installation method: A convex plate having a parabolic surface was installed under the imprint mold, and the imprint mold non-shaped surface was adhered to the plate and fixed.
(9) A film whose amount of plastic deformation changes according to pressure was pressed, and the thickness of the film after pressing was measured at intervals of 10 mm. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the pressure distribution in the longitudinal direction of the groove was investigated, the pressure distribution shown in FIG. 5 was obtained. That is, there is a maximum pressure portion at the center of the shaping surface, there is no minimum pressure portion in the shaping surface, and the amount of pressure decrease along the pressure gradient increases monotonously.
(10) Using the above apparatus, molding was performed under the same processing conditions as in Example 1.
The above operation was repeated to produce 10 molded sheets. As a result of visual evaluation of the molding surface, there was obtained a molding sheet that was uniformly transferred without air entrainment or transfer failure.

Example 4
(1) Imprint mold size: Same as Example 1.
(2) Imprint mold material: the same as in Example 1.
(3) Fine shape: a groove having a pitch of 25 μm, a convex portion height of 12.5 μm, and a cross section when viewed from the sheet running direction is a right-angled isosceles triangle, and the groove has a stripe shape.
(4) Press device: Same as Example 1.
(5) Temperature control: Same as Example 1.
(6) Sheet-like substrate: made of polyethylene terephthalate, having a thickness of 100 μm and a width of 520 mm.
(7) Intermediate base material: An ethylene propylene rubber having a thickness of 5 mm and a fluororesin (FEP) having a thickness of 200 μm bonded together were attached to the upper pressure plate. At this time, the fluororesin was superposed in the order in which it comes into contact with the sheet-like substrate.
(8) Imprint mold installation method: A convex plate having a parabolic surface was installed under the imprint mold, and the imprint mold non-shaped surface was adhered to the plate and fixed.
(9) A film whose amount of plastic deformation changes according to pressure was pressed, and the thickness of the film after pressing was measured at intervals of 10 mm. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the pressure distribution in the longitudinal direction of the groove was investigated, the pressure distribution shown in FIG. 5 was obtained. That is, there is a maximum pressure portion at the center of the shaping surface, there is no minimum pressure portion in the shaping surface, and the amount of pressure decrease along the pressure gradient increases monotonously.
(10) Using the above apparatus, molding was performed under the same processing conditions as in Example 1.
The above operation was repeated to produce 10 molded sheets. As a result of visual evaluation of the molding surface, there was obtained a molding sheet that was uniformly transferred without air entrainment or transfer failure.

Example 5
(1) Imprint mold size: Same as Example 1.
(2) Imprint mold material: the same as in Example 1.
(3) Fine shape: same as Example 4 (4) Press device: same as Example 1.
(5) Temperature control: Same as Example 1.
(6) Sheet-like base material: same as Example 4. (7) Intermediate base material: A fluororesin was laminated on a cushion material having a thickness of 2 mm in which a heat-resistant nylon woven fabric was impregnated with fluoro rubber. At this time, the fluororesin was superposed in the order in which it comes into contact with the sheet-like substrate.
(8) Imprint mold installation method: A convex plate having a parabolic surface was installed under the imprint mold, and the imprint mold non-shaped surface was adhered to the plate and fixed.
(9) A film whose amount of plastic deformation changes according to pressure was pressed, and the thickness of the film after pressing was measured at intervals of 10 mm. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the pressure distribution in the longitudinal direction of the groove was investigated, the pressure distribution shown in FIG. 5 was obtained. That is, there is a maximum pressure portion at the center of the shaping surface, there is no minimum pressure portion in the shaping surface, and the amount of pressure decrease along the pressure gradient increases monotonously.
(10) Using the above apparatus, molding was performed under the same processing conditions as in Example 1.
The above operation was repeated to produce 10 molded sheets. As a result of visual evaluation of the molding surface, there was obtained a molding sheet that was uniformly transferred without air entrainment or transfer failure.

  The results of Examples 1 to 5 are shown in Table 1. In the pressure distributions of Examples 1 and 2, the air could not be sufficiently discharged in the press time of 3 seconds. However, if the press time was extended to 15 seconds in Example 2, the air was completely discharged and uniform molding was performed. Became possible. This is because it takes time to completely discharge air because the air discharge speed decreases at the portion where the amount of change in pressure is reduced. In the pressure distributions of Examples 3 to 5, the amount of change in pressure along the pressure gradient is monotonically increasing, so the air discharge speed is increased, and the air that has been caught in the press time of 3 seconds is completely discharged. I was able to.

[Comparative Example 1]
Using the same apparatus as the apparatus of Example 3, except that the imprint mold was installed directly on the lower pressure plate without using a plate, and 10 molded sheets were created under the same conditions as in Example 3. Forming defects due to air biting occurred in all sheets. A film whose plastic deformation amount changes according to the pressure was pressed. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the thickness of the film after pressing in the longitudinal direction of the groove was measured at intervals of 10 mm and the pressure distribution was investigated, the pressure distribution shown in FIG. 14 was obtained, and there was no pressure gradient on the shaping surface during molding. For this reason, the cause of the molding failure is that the entrained air is not excluded.

[Comparative Example 2]
Using the same apparatus as the apparatus of Example 3, however, the imprint mold has a columnar rubber having a different height on the lower side outside the shaping surface to project the center of the shaping surface, It fixed to the lower pressurization plate so that it might press sequentially from the center part of a shaping surface at the time of a press start. Ten molded sheets were produced with this apparatus under the same conditions as in Example 3. However, molding defects occurred due to air biting in all the sheets. A film whose amount of plastic deformation changes according to the pressure was pressed, and the thickness of the film after pressing was measured at intervals of 10 mm. Measurement was performed such that a grid with a side of 10 mm was aligned in the direction (hereinafter referred to as the longitudinal direction of the groove) that was the longitudinal direction of the groove on the imprint mold shaping surface during pressing. When the pressure distribution in the longitudinal direction of the groove was investigated, the pressure distribution shown in FIG. 15 was obtained, and the pressure had a minimum value in the rubber gap. The cause of defective molding is that the trapped air remains in the minimum pressure part.

FIG. 1 is a schematic view schematically illustrating an imprint mold having a fine shape in a stripe shape, in one embodiment of the fine shape transfer imprint mold according to the present invention. FIG. 2 is a schematic diagram schematically illustrating an imprint mold in which fine shapes are two-dimensionally arranged in one embodiment of the fine shape transfer imprint mold according to the present invention. FIG. 3 shows a model of a pressure distribution having a maximum pressure on the x-axis center line of the shaping surface and no minimum pressure in the shaping surface, in one embodiment of the fine shape transfer sheet method according to the present invention. FIG. FIG. 4 shows a pressure distribution having a maximum pressure on the x-axis one end line of the shaping surface and no minimum pressure in the shaping surface in one embodiment of the fine shape transfer sheet method according to the present invention. It is the schematic shown as a model. FIG. 5 is a schematic diagram illustrating the front view of FIG. 3. FIG. 6 is a schematic diagram schematically showing an example in which the pressure change amount does not monotonously increase according to the pressure gradient. FIG. 7 is a schematic diagram schematically illustrating an embodiment of a fine shape transfer imprint mold according to the present invention in which the imprint mold has a thickness distribution. FIG. 8 is a schematic view schematically illustrating a curved shape of an imprint mold in one embodiment of the fine shape transfer imprint mold according to the present invention. FIG. 9 is a schematic diagram schematically illustrating one embodiment of the fine shape transfer method according to the present invention in which a convex plate having a thickness distribution is placed on the side opposite to the shaping surface of the imprint mold. . FIG. 10 is a front view schematically explaining the deformation of the intermediate substrate in one embodiment of the fine shape transfer method according to the present invention. FIG. 11 is a schematic front view schematically showing an embodiment of the apparatus for producing a fine shape transfer sheet according to the present invention. FIG. 12 is a schematic front view schematically illustrating the state when the applied pressure on the shaping surface becomes maximum in FIG. 11. FIG. 13 is a schematic front view schematically showing the mold installation state used in Examples 1 and 2. FIG. 14 is a schematic diagram schematically showing the pressure distribution of Comparative Example 1. FIG. 15 is a schematic diagram schematically showing the pressure distribution of Comparative Example 2.

1: Fine shape transfer sheet manufacturing device 2: Press device 3: Upper pressure plate 4: Lower pressure plate 5: Sheet substrate 6: Intermediate substrate 7: Plate 8: Imprint mold 8a: Imprint mold shaping surface

Claims (8)

An imprint mold having a shaping surface composed of fine irregularities;
A pair of pressure plates disposed so as to sandwich the intermediate substrate, the imprint mold, and the intermediate substrate from both sides;
A pressurizing means for pressurizing the imprint mold, the intermediate substrate and the pair of pressure plates;
And at least a convex plate installed on the surface on the pressure direction side of at least one pressure plate of the pair of pressure plates,
An apparatus for manufacturing a fine shape transfer sheet, wherein the plate has a thickness distribution, has a maximum thickness portion in the plane of the plate, and does not have a portion having a minimum thickness in the plane.   2. The fine according to claim 1, wherein the concave and convex shapes of the imprint mold are a plurality of grooves arranged in parallel, and the plate is installed so that a thickness change of the plate is along a longitudinal direction of the grooves. Shape transfer sheet manufacturing equipment.   The apparatus for producing a fine shape transfer sheet according to claim 1 or 2, wherein an absolute value of a thickness change amount per unit length of the plate monotonously increases along a thickness gradient from the maximum thickness portion.   The fine shape transfer sheet according to any one of claims 1 to 3, wherein the imprint mold is held in close contact with the plate, and the shaping surface of the imprint mold has the same curved profile as the plate. manufacturing device.   The apparatus for producing a fine shape transfer sheet according to any one of claims 1 to 4, wherein the intermediate substrate has cushioning properties.   The intermediate base material having cushioning properties is (a) a polymer material having bubbles inside, (b) a composite material in which a rubber layer and a fiber layer are laminated, and (c) a composite material in which a rubber layer is impregnated with rubber. The apparatus for producing a fine shape transfer sheet according to claim 5, comprising at least one selected from the group consisting of:   The intermediate substrate according to any one of claims 1 to 6, wherein the compression elastic modulus is 0.1 MPa to 200 MPa over the entire shaping surface when the pressing force of the shaping surface becomes maximum. Manufacturing equipment for fine shape transfer sheet.   The manufacturing apparatus of the fine shape transfer sheet in any one of Claims 1-7 provided with the means to heat a sheet-like base material and the said imprint mold.

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