JP6647964B2 - Cushion material for hot press and method for producing the same - Google Patents

Description

  The present invention relates to a cushioning material for hot press used between a press board and an object to be pressed, and a method for producing the same.

  In general, in the manufacturing process of a laminated board having a laminated structure, such as a printed circuit board such as a copper-clad laminate, a flexible printed board, and a layered laminate, an IC card, a ceramic laminate, and a liquid crystal display panel, press molding or thermocompression bonding is performed. A hot press is performed. When performing hot pressing, a flat plate-like cushion material for hot pressing and a mirror plate made of stainless steel plate are placed between the press platen and the pressing target to apply heat and pressure uniformly to the pressing target. Is done. Such a cushioning material for hot press is required to have cushioning properties, thermal conductivity, heat resistance and durability. Examples of such a hot-press cushion material include a rubber layer made of a fluororubber and the like, an intermediate layer made of a multi-woven cloth of heat-resistant fibers such as a glass fiber and an aromatic polyamide fiber, and a glass fiber and an aromatic polyamide fiber. In general, a surface layer composed of the above fibrous members is laminated. When producing such a cushioning material for hot press, usually, a rubber sheet serving as a rubber layer, a multi-woven cloth serving as an intermediate layer and a fiber member serving as a surface layer are combined and laminated, and integrated by vulcanization. . After that, it is cut into a size suitable for a predetermined press board.

  The material used for the surface layer of the cushioning material for hot pressing is required to have properties such as airtightness when suctioned and conveyed by an automatic laminating apparatus and the like, and releasability from a press plate or a mirror plate after hot pressing. As well as high cushioning properties as a hot press cushion material. Here, the releasability refers to ease of removal from a mold such as a press machine or a mirror plate. Specifically, the releasability refers to a property that does not cause sticking or seizure on the surface, and is also referred to as non-stickiness. As such a cushioning material for hot press, for example, in Patent Document 1, a rubber layer of fluorine rubber having good heat resistance is formed on both surfaces of a glass fiber cloth as an intermediate layer, and aramid fiber or the like is formed on the rubber layer. A hot-press cushion material in which a surface layer made of wholly aromatic fibers having good heat resistance is laminated is described. Patent Document 2 describes production of a hot-press cushion material in which a surface layer is coated with a release film containing a fluororesin. As shown in FIG. 4A, the cushioning material for hot press completely covers the fibers constituting the surface layer with the releasable coating film. It is possible.

  However, the cushioning material for hot press described in Patent Document 1 has insufficient airtightness of the surface layer, and thus has a problem such as dropping when suctioned and conveyed by an automatic laminating apparatus or the like. Had been.

  In addition, the cushioning material for hot press described in Patent Literature 2 is designed so that the unevenness such as the texture of the fiber member constituting the surface layer appears over the entire surface, and the surface does not have sink marks or dents. Although the amount of the applied release coating is adjusted, there is a problem that the surface roughness of the surface layer is reduced because the entire surface layer is completely covered with the release coating. is there. When a hot-press cushion material having a small surface roughness is used for the press, it is difficult for air to enter between the hot-press cushion material and the press platen, so that the hot-press cushion material adheres to the press plate or the like. As a result, there is a problem that the releasability from a press board or the like is deteriorated. The press board and the like include not only a press board and a mirror plate, but also those used in close contact with a cushioning material for hot pressing during hot pressing. In addition, when used repeatedly, as shown in FIG. 4 (b), the unevenness is crushed and the surface roughness is further reduced. is there.

  Further, in the case of a hot-press cushion material having a small surface roughness of the surface layer, the hardness of the hot-press cushion material is relatively high. Since the surface does not easily follow the object to be pressed, and the pressure is not easily applied evenly, there is a problem that the object to be pressed is likely to be warped. In particular, when the thickness of the object to be pressed is small, there is a problem that warpage is conspicuous and easily occurs.

JP-A-6-305091 JP-A-2004-344962

  The present invention is intended to solve the above-mentioned problems, is capable of suction conveyance, has good releasability from a press platen, and the like, and does not cause warpage of a press object. And a method for producing the same.

  In order to solve the above problems, the hot-press cushion material according to the present invention is a hot-press cushion material that is used by being interposed between a press board and an object to be pressed, and at least two rubber layers, An intermediate layer made of a bulky multi-woven cloth interposed between the rubber layers, and a laminated body in which a laminate or a woven or knitted fabric having a yarn made of a heat-resistant fiber member is formed, and an outermost side of the laminated body A surface layer laminated on both sides of the rubber layer, wherein the surface layer is impregnated inside the yarn, and is thin enough to not cover unevenness formed on the surface where the yarn intersects. Now, it has a heat-resistant resin attached to the surface of the woven or knitted fabric, and is preliminarily subjected to a heat treatment at a temperature of 360 to 430 ° C.

  According to the cushioning material for hot press of the present invention, the surface layer is made of a woven or knitted fabric having a yarn made of a heat-resistant fiber member. Further, the surface layer has a heat-resistant resin which is impregnated into the interior of the yarn and is attached to the surface of the woven or knitted fabric with such a thickness that the yarn does not intersect and cover the unevenness formed on the surface. The fact that the yarn intersects so as not to cover the unevenness formed on the surface by crossing means that the heat-resistant resin adheres to the surface of the yarn along the shape of the yarn at the portion where the yarn crosses. . Thereby, since the gap formed by the yarn intersecting the surface layer exists without being covered with the heat-resistant resin, the surface roughness of the surface layer increases, and the releasability from the press plate or the like is improved. Can be And even after repeatedly using the cushioning material for hot pressing, the unevenness formed on the surface of the surface layer due to the crossing of the threads is hard to disappear, so that the releasability from the press platen or the like can be maintained favorably. . The surface layer is previously subjected to a heat treatment at a temperature of 360 to 430 ° C. Thereby, by performing the heat treatment at a higher temperature than in the related art, it is possible to sufficiently remove a highly adhesive organic component such as a dispersant added when impregnating the surface layer with the heat resistant resin. At the same time, the crystallinity of the heat-resistant resin is increased, so that the surface of the surface layer can be formed harder, and the releasability from the press plate or the like can be more favorably maintained. In addition, the surface layer has a large surface roughness, and there are many gaps in the surface layer. However, the anchor effect of the heat-resistant resin impregnated in the surface layer and the rubber layer laminated on the inside of the surface layer causes the rubber layer to have a large thickness. The rubber penetrates into the gaps in the surface layer, and the gaps in the surface layer are closed to block the air flow, so that the airtightness can be increased, and the suction conveyance can be performed. Furthermore, since the weaving density is small and the amount of the heat-resistant resin is small, the hardness of the cushioning material for hot pressing is low, and the flexibility of the cushioning material for hot pressing is provided to prevent the warping of the pressing object. be able to.

  Alternatively, the hot-press cushion material according to the present invention is a hot-press cushion material that is used by being interposed between a press board and an object to be pressed, wherein at least two rubber layers and the rubber layers are provided. An intermediate layer consisting of a bulky multi-woven cloth interposed between the laminated body and a woven or knitted fabric having a yarn made of a heat-resistant fiber member, and both sides of the outermost rubber layer of the laminated body Wherein the surface layer is impregnated into the interior of the yarn, and the woven or knitted fabric has such a thickness that the yarn intersects and does not cover irregularities formed on the surface. And a melting curve measured by a differential scanning calorimeter at a heating rate of 10 ° C./min in a temperature range from 40 ° C. to 420 ° C. in a nitrogen atmosphere using a differential scanning calorimeter. Near the melting point of the resin Heat of fusion calculated from the melting peak temperature is at 4.0 mJ / mg or more, and a crystallinity, as measured with the surface by X-ray diffractometry is 80% or more.

  According to the cushioning material for hot press of the present invention, the surface layer is made of a woven or knitted fabric having a yarn made of a heat-resistant fiber member. Further, the surface layer has a heat-resistant resin which is impregnated into the interior of the yarn and is attached to the surface of the woven or knitted fabric with such a thickness that the yarn does not intersect and cover the unevenness formed on the surface. The fact that the yarn intersects so as not to cover the unevenness formed on the surface by crossing means that the heat-resistant resin adheres to the surface of the yarn along the shape of the yarn at the portion where the yarn crosses. . Thereby, since the gap formed by the yarn intersecting the surface layer exists without being covered with the heat-resistant resin, the surface roughness of the surface layer increases, and the releasability from the press plate or the like is improved. Can be And even after repeated use of the cushioning material for hot pressing, the unevenness formed on the surface of the surface layer due to the crossing of the threads is difficult to disappear, so that the releasability from the press plate or the like can be maintained favorably. . In addition, the surface layer has a heat of fusion of 4.0 mJ / mg or more calculated from a melting peak temperature appearing near the melting point of the heat-resistant resin, and the surface has a crystallinity of 80% as measured by an X-ray diffraction method. That is all. As a result, since the heat of fusion of the peak appearing near the melting point of the heat-resistant resin is high, the organic component having high adhesiveness is removed without remaining on the surface of the surface layer, and the crystallinity of the heat-resistant resin attached to the surface is removed. , The surface of the surface layer becomes hard. Therefore, the cushioning material for hot press does not stick to the press board or the like, and the releasability from the press board or the like is further improved. In addition, the surface layer has a large surface roughness, and there are many gaps in the surface layer. However, the anchor effect of the heat-resistant resin impregnated in the surface layer and the rubber layer laminated on the inside of the surface layer causes the rubber layer to have a large thickness. The rubber penetrates into the gaps in the surface layer, and the gaps in the surface layer are closed to block the air flow, so that the airtightness can be increased, and the suction conveyance can be performed. Further, since the weaving density is small and the amount of the heat-resistant resin is small, the hardness of the hot-press cushion material is small, and the flexibility of the hot-press cushion material is provided to prevent the press target from warping. be able to.

In the cushioning material for hot press, the surface layer may have a porosity of the woven or knitted fabric of 10 to 80% and an impregnation amount of the heat-resistant resin of 100 to 200 g / m ² .
The porosity of the woven or knitted fabric constituting the surface layer is 10 to 80%, and the impregnation amount of the heat-resistant resin is 100 to 200 g / m ^2. The porosity of the woven or knitted fabric having the yarn is adjusted to such an extent that irregularities are formed on the surface, and the impregnation amount of the heat-resistant resin is impregnated into the interior of the fiber member, and does not cover the irregularities on the surface. Can be adjusted to such an extent that it adheres to the surface of a woven or knitted fabric.
Here, the porosity means the ratio of the space in the substance calculated from the difference between the actual volume and the apparent volume.

In the above-mentioned cushioning material for hot press, the woven density of the warp and the weft of the woven fabric or the knitting density of the knitted fabric may be 25 to 100 yarns / in, and the warp of the yarn may be 300 to 600 µm.
The porosity of a woven or knitted fabric changes depending on the weaving density of the woven fabric or the knitting density of the knitted fabric and the diameter of the yarn. Therefore, by setting the weaving density of the warp and the weft of the woven fabric or the knitting density of the knitted fabric to 25 to 100 yarns / in and the warp of the yarn to 300 to 600 μm, the voids of the woven or knitted fabric constituting the surface layer The rate can be adjusted to 10-80%.

In the above cushioning material for hot press, the air permeability of the cushioning material for hot press may be 1.0 cm ³ / cm ² · s or less.
By setting the air permeability of the entire cushioning material for hot press to 1.0 cm ³ / cm ² · s or less, airtightness can be ensured and suction conveyance can be performed.

In the above cushioning material for hot press, the amount of deflection of the cushioning material for hot pressing may be 5 to 150 mm.
If the amount of deflection is less than 5 mm, the flexibility of the cushioning material for hot pressing is low, it is difficult to follow the pressing object, and warpage occurs. On the other hand, if the amount of deflection exceeds 150 mm, the flexibility is too high to allow suction conveyance. That is, the hot-press cushion material hangs down by its own weight and falls from the suction pad. Therefore, by setting the amount of deflection of the hot-press cushion material to 5 to 150 mm, it is possible to achieve both the flexibility of the hot-press cushion material (prevention of warpage of the press target) and the suction conveyance property.

In the cushioning material for hot press, the surface roughness of the surface layer may be an arithmetic average roughness Ra of 20 μm or more and Ra of 60 μm or less, more preferably Ra of 50 μm or less.
By setting the surface roughness of the surface layer to an arithmetic average roughness Ra of 20 μm or more, the releasability from a press plate or the like can be improved. And by setting the surface roughness of the surface layer to Ra 60 μm, more preferably Ra 50 μm or less, it is possible to secure the suction conveyance property. Therefore, by setting the surface roughness of the surface layer to Ra 20 or more and Ra 60 μm or less, more preferably Ra 50 μm or less, it is possible to achieve both release properties and suction conveyance properties. Arithmetic mean roughness Ra is defined in JIS B 0031.

In the cushioning material for hot press, the heat-resistant fiber member may be glass fiber.
Since the heat-resistant fiber member is glass fiber, a surface layer having excellent heat resistance, high strength, and high elasticity can be formed.

In the cushioning material for hot press, the heat-resistant resin may be a fluororesin.
Since the heat-resistant resin is a fluororesin, a surface layer having excellent heat resistance and low compression set can be formed.

The method for manufacturing a cushioning material for hot press of the present invention is the method for manufacturing a cushioning material for hot pressing, wherein the surface layer is formed by impregnating the woven or knitted fabric impregnated with the heat-resistant resin at a temperature of 360 to 430 ° C. It is formed by performing a heat treatment in advance at a temperature.
The surface layer is previously subjected to a heat treatment at a temperature of 360 to 430 ° C. Thereby, by performing the heat treatment at a higher temperature than in the related art, it is possible to sufficiently remove a highly adhesive organic component such as a dispersant added when impregnating the surface layer with the heat resistant resin. At the same time, the crystallinity of the heat-resistant resin is increased, so that the surface of the surface layer can be formed harder, and the releasability from the press plate or the like can be more favorably maintained. In addition, the surface layer has a large surface roughness, and there are many gaps in the surface layer. However, the anchor effect of the heat-resistant resin impregnated in the surface layer and the rubber layer laminated on the inside of the surface layer causes the rubber layer to have a large thickness. The rubber penetrates into the gaps in the surface layer, and the gaps in the surface layer are closed to block the air flow, so that the airtightness can be increased, and the suction conveyance can be performed. Furthermore, since the weaving density is small and the amount of the heat-resistant resin is small, the hardness of the cushioning material for hot pressing is low, and the flexibility of the cushioning material for hot pressing is provided to prevent the warping of the pressing object. be able to.

  As described in the above description, according to the present invention, a hot-press cushion material that can be suction-conveyed, has good releasability from a press platen and the like, and does not cause warpage of an object to be pressed, and The manufacturing method can be provided.

It is a mimetic diagram explaining a hot press using a cushioning material for hot press concerning this embodiment. It is a mimetic diagram showing the section of the cushioning material for hot press concerning this embodiment. It is a schematic diagram which shows the cross section of the surface layer of the cushioning material for hot press which concerns on this embodiment, (a) shows the state before press, and (b) shows the state after using repeatedly for press. It is a schematic diagram which shows the cross section of the surface layer of the cushioning material for hot press which concerns on a prior art, (a) shows the state before press, and (b) shows the state after using repeatedly for press.

An embodiment of the present invention will be described with reference to the drawings.
The cushioning material for hot pressing according to the present embodiment is used for manufacturing a laminated board having a laminated structure, such as a printed board such as a copper-clad laminate, a flexible printed board, and a layer laminate, an IC card, a ceramic laminate, and a liquid crystal display panel. Is used for press molding or hot pressing for thermocompression bonding.

[Heat press]
First, a hot press using the hot-press cushion material according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, an example in which a press target 21 is press-formed by a press platen 20 using the hot-press cushion material 1 according to the present embodiment is shown.

  As shown in FIG. 1, two flat hot-press cushion materials 1 are disposed between two press boards 20, and a stainless steel plate is interposed between the two hot-press cushion materials 1. The press object 21 is arranged via 22. That is, the hot-press cushion material 1 and the stainless steel plate 22 are interposed between the two press boards 20 and the press target 21, respectively. In this state, heat and pressure are applied by the press platen 20. The pressing conditions are, for example, a temperature of normal temperature to 260 ° C., a pressure of 0.5 to 100 MPa, and a pressing time of 1 to 3 hours. The hot-press cushion material 1 is used for the purpose of uniformly applying pressure and heat to the press target 21.

[Cushion material for hot press]
Next, the hot-press cushion material 1 according to the present embodiment will be described with reference to FIGS. 2 and 3.

  As shown in FIG. 2, the cushioning material 1 for hot press is formed by laminating a rubber layer 4, an intermediate layer 5, and a surface layer 6. The cushioning material for hot press 1 according to the present embodiment includes a laminate 2 and a surface layer 6. The laminate 2 includes three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4. Rubber layers 4 are arranged on both outermost sides of the laminate 2. The two surface layers 6 are laminated on both sides of the outermost rubber layer 4 of the laminate 2.

  That is, the cushioning material for hot press 1 is laminated in the order of the surface layer 6, the rubber layer 4, the intermediate layer 5, the rubber layer 4, the intermediate layer 5, the rubber layer 4, and the surface layer 6 in the vertical direction on the paper surface shown in FIG. It was done. The intermediate layer 5 and the rubber layer 4 are not limited to two layers and three layers, respectively. For example, the laminate 2 may be configured by using the intermediate layer 5 as one layer and interposing between the two rubber layers 4. Alternatively, the intermediate layer 5 may be formed into three layers, and may be interposed between the four rubber layers 4 to form the laminate 2.

The rubber layer 4 is composed of a rubber composition. As the rubber component, fluorine rubber or silicone rubber excellent in heat resistance and low compression set can be used. When the compression set is small, the durability is improved. Further, the rubber composition preferably has a minimum Mooney viscosity Vm value of 25 to 75 in an unvulcanized state. The minimum Mooney viscosity is measured with a Mooney viscometer. By using an unvulcanized rubber composition having a minimum Mooney viscosity Vm of 25 to 75 for the rubber layer 4 and controlling the fluidity of the rubber, the rubber is dammed near the surface of the intermediate layer 5 by the anchor effect, and A void inside the layer 5 can be secured, and cushioning properties can be secured. Moreover, the rubber | gum of the rubber layer 4 becomes easy to invade into the clearance gap of the surface layer 6 by an anchor effect, and it can block airflow and can secure airtightness. That is, when the unvulcanized rubber composition used for the rubber layer 4 has the minimum Mooney viscosity Vm value in the range of 25 to 75, both cushioning property and airtightness can be achieved. The unvulcanized rubber composition means a rubber composition in an unvulcanized state. When the unvulcanized rubber composition used for the rubber layer 4 has a minimum Mooney viscosity Vm value of less than 25, the fluidity of the rubber increases. For this reason, the rubber of the rubber layer 4 easily penetrates into the gap formed by the yarns of the surface layer 6 intersecting with each other, so that the ventilation can be blocked and the airtightness can be secured. On the other hand, rubber cannot be dammed in the vicinity of the surface of the intermediate layer 5, and it becomes impossible to secure a void inside the intermediate layer 5, and the cushioning property is reduced. When the minimum Mooney viscosity Vm value of the unvulcanized rubber composition used for the rubber layer 4 exceeds 75, the fluidity of the rubber decreases. Therefore, the rubber of the rubber layer 4 is appropriately infiltrated into the fine irregularities on the surface of the intermediate layer 5, and the rubber is dammed near the surface of the intermediate layer 5 by the anchor effect, thereby securing a space inside the intermediate layer 5. Can improve cushioning. On the other hand, it becomes difficult for the rubber of the rubber layer 4 to penetrate into the gap formed by the yarns of the surface layer 6 intersecting with each other, so that the air cannot be blocked and airtightness cannot be secured. In addition, the gap of the surface layer 6 means a gap formed by crossing woven yarns of the woven fabric 60 described later. Examples of the type of the fluorine rubber include a fluorine-containing acrylate polymer, a vinylidene fluoride copolymer, a fluorine-containing silicon rubber, and a fluorine-containing polyester rubber.
Here, the minimum Mooney viscosity Vm value is a value measured according to the standard of JIS K6300 (2013).

  When a fluororubber composition is used for the rubber layer 4, diacyl peroxide, peroxyester, diallyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 5-dimethyl-2,5-di (t-butylperoxy) -hexane-3,1.3-bis (t-butylperoxy-isopropyl) benzene, 1.1-di-butylperoxy-3, Organic peroxide-based crosslinking agents such as 3,5-trimethylcyclohexane, polyol-based crosslinking agents such as hexamethylene carbamate, N, N'-dicyanyldiene-1,6-hexadiamine, bisphenol AF, benzyltriphenylphosphonium chloride , And triethylenetetramine (TETA), triethylenepentamine (T Known crosslinking agents for fluorine rubber, such as amine-based crosslinking agents such as EPA) and hexamethylenediamine (HMDA), can be used.

  When a silicone rubber composition is used for the rubber layer 4, a known organic peroxide-based crosslinking agent can be used as the crosslinking agent.

  Further, the rubber composition constituting the rubber layer 4 contains, as necessary, those used in ordinary rubber compounds such as fillers, plasticizers, stabilizers, processing aids, and coloring agents. You. Furthermore, short fibers may be included in the rubber composition for rubber reinforcement. As the short fibers, heat-resistant fibers such as glass fibers, aramid fibers, and PBO (polybenzobisoxazole) fibers are used.

  Here, in the unvulcanized hot-press cushion material 1, the average thickness per rubber layer 4, that is, the average thickness of one rubber sheet to be the rubber layer 4 before pressure lamination. Is preferably 4 to 10% of the entire thickness of the cushioning material 1 for press. If it is less than 4%, the adhesive strength between the rubber layer 4 and the intermediate layer 5 (or the surface layer 6) may be reduced. On the other hand, if it exceeds 10%, the material cost increases, and the heat transferability may be reduced by the increase in the total thickness of the hot-press cushion material 1.

  The mid layer 5 is composed of a multi-woven cloth. Examples of the multi-woven cloth include a double-woven cloth, a triple-woven cloth, and a quadruple-woven cloth, and a cloth woven with crimped yarn or a cloth that is bulky in a cross state can be used.

  The multi-woven cloth is a woven fabric having a multilayer structure using a plurality of sets of wefts and warps. For example, a double-woven cloth has a double-woven structure in which two sets of upper and lower wefts are entangled with one set of warps. There are many voids inside the multi-woven cloth. Further, by crimping the constituent yarn or performing bulky processing in a cross state, the voids inside the cloth further increase. As described above, since the intermediate layer 5 has a structure in which many voids are present inside, the intermediate layer 5 has a high cushioning property and a function of preventing deformation when repeated pressing is performed.

  Glass fibers, carbon fibers, ceramic fibers, aramid fibers, PBO (polybenzobisoxazole) fibers, and the like are used as constituent yarns of the multi-woven cloth constituting the intermediate layer 5. Preferably, inorganic fibers such as glass fibers, carbon fibers, and ceramic fibers are used. These have excellent heat resistance, high strength and high elasticity. Therefore, the rubber layer 4 made of the rubber composition can be reinforced.

  When glass fibers are used as constituent yarns of the multi-woven cloth constituting the intermediate layer 5, the surface of the multi-woven cloth may be treated with a silane coupling agent. Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane , N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-aminoethyl-γ-aminopropyltrimethoxysilane (hydrochloride), γ-glycidoxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like can be used. By treating the surface of the multi-woven cloth with a silane coupling agent, the adhesion between the rubber layer 4 and the intermediate layer 5 is improved when the rubber layer 4 is made of a fluororubber composition.

  As shown in FIG. 3, the surface layer 6 is formed of a woven fabric 60 woven with woven yarns (warp 61 and weft 62) made of a heat-resistant fiber member. That is, the woven fabric 60 has the warp 61 and the weft 62. In addition, in this embodiment, although the surface layer 6 is comprised by the fabric 60, it is not restricted to it, The surface layer 6 may be comprised by the knitted fabric knitted with the thread | yarn which consists of a heat resistant fiber member. The woven fabric 60 is made of woven fabric such as plain weave, twill weave, and satin weave. Particularly, a twill weave is preferable from the viewpoint of stretchability and flexibility. The woven fabric 60 is woven so as to have a predetermined porosity to the extent that irregularities exist on the surface of the surface layer 6. The porosity means a ratio of a space in a substance calculated from a difference between an actual volume and an apparent volume. Here, if the predetermined porosity of the woven fabric 60 is too small, the space between the woven yarns (the warp yarns 61 and the weft yarns 62) becomes too dense. If the spaces between the yarns are too dense, the surface roughness of the surface layer 6 is small, and the hardness of the hot-press cushion material 1 is high, which is preferable from the viewpoint of the releasability and flexibility of the hot-press cushion material 1. Absent. On the other hand, if the predetermined porosity of the woven fabric 60 is too large, a large gap is formed between the yarns. If a large gap is formed between the yarns, the air permeability of the hot-press cushion material 1 increases, which is not preferable from the viewpoint of suction-conveyability. Therefore, the predetermined porosity is such that there are irregularities on the surface of the surface layer 6, is smaller than the porosity in which a gap is formed between the yarns, and the porosity is too dense between the yarns. Lower weave density. Specifically, the predetermined porosity is, for example, 10 to 80%.

  Since the porosity of the woven fabric 60 changes depending on the diameter and the weaving density of the woven yarn, the warp yarn 61 and the weft yarn 62 having a predetermined diameter are woven by a predetermined weaving so that the woven fabric 60 has a predetermined porosity. Woven in density. Here, the diameter of the woven yarn means the diameter of the yarn in a state where the filaments are bundled. If the diameter of the yarn is too large, the space between the yarns becomes too dense and the porosity decreases. If the diameter is too small, a gap is formed between the yarns and the porosity increases. On the other hand, if the weaving density is too high, the space between the yarns becomes too dense and the porosity decreases. If the weaving density is too low, a gap is formed between the yarns and the porosity increases. Specifically, the diameter of the predetermined woven yarn is 300 to 600 μm. The predetermined weaving density is, for example, 25 to 100 yarns / in for both the warp 61 and the weft 62.

  Glass fibers, carbon fibers, ceramic fibers, aramid fibers, PBO fibers, fluorine fibers, and the like are used as the heat-resistant fiber members serving as the base material of the woven yarns (warp yarns 61 and weft yarns 62). Since the surface layer 6 of the hot-press cushion material 1 is made of a woven fabric 60 woven with a woven yarn made of a heat-resistant fiber member, the surface of the hot-press cushion material 1 is hardly damaged, so that the pressing is performed uniformly. can do. In particular, as the heat-resistant fiber member, glass fiber having excellent heat resistance, high strength, and high elasticity is preferable. When glass fiber is used for the heat-resistant fiber member, since the molded hot-press cushion material 1 has a certain degree of hardness, even if the hot-press cushion material 1 is molded in a size of several meters × several meters, There is an advantage that it does not hang down due to its own weight and does not drop from the suction / transport device. Further, since the adhesive force between the glass fiber and the heat-resistant resin is not weak as in the case of using other heat-resistant fibers such as aramid fiber, and the adhesive force is strong even at a high temperature, it can be used up to 260 ° C. In the present invention, it is assumed that it is used in the range of 180 to 240 ° C). Further, there is an advantage that the fibers are not degraded even in a high-temperature hot press and no fluff is generated.

  Further, the fabric 60 is impregnated with a heat-resistant resin 63. Examples of the heat-resistant resin 63 include, for example, an epoxy resin, a phenol resin, a melamine resin, a fluororesin, an unsaturated polyester resin, a silicone resin, a polyimide resin, a thermosetting acrylic resin, a furan resin, a urea resin, a diallyl phthalate resin, and the like. , A blend system or a copolymer. Among them, a fluororesin having good heat resistance and low compression set is most preferable.

  The surface layer 6 appears near the melting point of the heat-resistant resin 63 in a melting curve measured by a differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min in a temperature range from 40 ° C. to 420 ° C. in a nitrogen atmosphere. The heat of fusion calculated from the melting peak temperature is 4.0 mJ / mg or more. The surface layer 6 is configured so that the degree of crystallinity on the surface thereof measured by the X-ray diffraction method is 80% or more. The degree of crystallinity is calculated by the following equation using, for example, the θ-2θ method of the X-ray diffraction method.

Crystallinity (%) = (crystalline scattering intensity / total scattering intensity) × 100
Here, total scattering intensity = crystalline scattering intensity + amorphous scattering intensity

The heat-resistant resin 63 impregnates the fabric 60 at a predetermined impregnation amount. As shown in FIG. 3 (a) before pressing and FIG. 3 (b) after repeatedly used in the pressing, the predetermined impregnation amount is defined as the amount of the impregnated yarn inside the woven fabric 60 (warp 61, weft 62). This is an amount that is impregnated and adheres so thinly that the warp 61 and the weft 62 intersect and do not cover the irregularities formed on the surface (to the extent that the irregularities are retained). In addition, when the warp 61 and the weft 62 intersect and adhere to such an extent that the unevenness formed on the surface is not covered, the heat-resistant resin 63 is used at the intersection of the warp 61 and the weft 62 to form the warp 61 and the weft 62. (See FIG. 3). Here, if the impregnation amount of the heat-resistant resin 63 is too small, impregnation inside the woven yarn and adhesion of the surface of the woven fabric become insufficient, the airtightness of the surface layer 6 is insufficient, and the cushioning material 1 for hot press is not used. If the air permeability is too large, it is not preferable from the viewpoint of the suction conveyance property. If the air permeability is too large, the warp yarn 61 and the weft yarn 62 intersect and the unevenness formed on the surface is crushed (see FIG. 4), and the surface layer 6, the surface roughness of the surface is small, and the hardness of the hot-press cushion material 1 is increased, which is not preferable from the viewpoint of the releasability and flexibility of the hot-press cushion material 1. Therefore, the predetermined impregnation amount is impregnated into the woven yarn (warp 61, weft 62) constituting the woven fabric 60, does not cover the unevenness formed on the surface of the woven fabric 60, and adheres thinly enough to maintain the unevenness. Adjusted to the quantity. Specifically, the predetermined impregnation amount is, for example, 100 to 200 g / m ² .

  Further, the impregnation of the heat-resistant resin 63 into the woven fabric 60 can be performed by using a known coating and dipping technique such as blade coating, knife coating, and cast coating. Here, the heat-resistant resin 63 is used for impregnation as a liquid dispersion (or an emulsion; hereinafter, abbreviated as “dispersion”) by dispersing a particulate heat-resistant resin in water. An organic component is added to the liquid dispersion as a dispersant (surfactant) in order to enhance the dispersion of the heat-resistant resin.

  The surface layer 6 is previously subjected to a heat treatment at a temperature of 360 to 430 ° C. That is, the surface layer 6 is subjected to a heat treatment at a temperature of 360 to 430 ° C. after the woven fabric 60 is impregnated with the heat-resistant resin 63. Specifically, after performing the heat treatment process of the textile 60, the surface layer 6 impregnates the textile 60 with the heat-resistant resin 63, the drying process of removing the moisture of the surface layer 6, and the organic component of the surface layer 6. It is formed by repeating a heat treatment step of removing, a baking step of fusing the heat-resistant resins 63 impregnated in the surface layer 6 together, and a cooling step of cooling the surface layer 6. Heat treatment is performed at a temperature of 430 ° C.

[Production method of cushioning material for hot press]
Next, a manufacturing method for manufacturing the cushioning material for hot press according to the present embodiment will be described.

  First, as described above, the woven fabric 60 impregnated with the two heat-resistant resins 63 to be the surface layer 6 is formed by performing a heat treatment in advance at a temperature of 360 to 430 ° C.

  Then, three unvulcanized rubber sheets to be the rubber layers 4 and two multi-woven cloths to be the intermediate layers 5 are alternately laminated so that the rubber sheets are on the outside, thereby forming the laminate 2. . Next, the laminate 2 is sandwiched from both sides of the surface (that is, both sides of the outermost rubber sheet) with a fabric 60 impregnated with two heat-resistant resins to be the surface layer 6. Then, under heating (temperature: 150 to 180 ° C.), after leaving for 0.2 to 15 minutes in a non-pressure state, immediately after the cross-linking reaction of the rubber layer 4 starts to work, the surface pressure is reduced while maintaining the temperature. It pressurizes to 0.1 to 5.0 MPa, press-vulcanizes under the conditions of a press time of 10 to 40 minutes, and integrates. Then, it is cut into a size suitable for a predetermined press board to produce the cushioning material 1 for hot pressing.

  In order to improve the compression set, after-cure may be performed on the hot-press cushion material 1 before cutting into a predetermined size at 200 to 250 ° C. for 30 minutes to 4 hours.

  As described above, according to the cushioning material 1 for hot press according to the present embodiment, the surface layer 6 is made of the woven or knitted fabric 60 having the woven yarn (warp 61 and weft 62) made of the heat-resistant fiber member. The surface layer 6 is made of a heat-resistant resin 63 impregnated into the interior of the woven yarn and attached to the surface of the woven or knitted fabric with such a thickness that the woven yarn crosses and does not cover irregularities formed on the surface. (See FIG. 3A). Thereby, since the gap formed by intersecting the woven yarn with the surface layer 6 is present without being covered with the heat-resistant resin 63, the surface roughness of the surface layer 6 is increased, and the gap between the surface layer 6 and the press platen is increased. Good moldability can be obtained. Then, even after repeated use of the cushioning material 1 for hot pressing, as shown in FIG. 3B, the unevenness formed on the surface of the surface layer 6 due to the intersecting of the woven yarns is difficult to disappear, so And the mold releasability can be favorably maintained.

  Further, the surface layer 6 is previously subjected to a heat treatment at a temperature of 360 to 430 ° C. Thereby, by performing the heat treatment at a higher temperature than in the related art, it is possible to sufficiently remove the highly adhesive organic components such as the dispersant added when the surface layer 6 is impregnated with the heat resistant resin 63. In addition, the crystallinity of the heat-resistant resin 63 can be increased, and the surface of the surface layer 6 can be formed harder, so that the releasability from the press platen or the like can be more favorably maintained.

  The surface layer 6 has a heat of fusion of 4.0 mJ / mg or more calculated from a melting peak temperature that appears near the melting point of the heat-resistant resin 63, and the crystallinity of the surface measured by an X-ray diffraction method is 80% or more. Thereby, since the heat of fusion of the peak appearing near the melting point of the heat-resistant resin 63 is high, the organic component having high adhesiveness is removed without remaining on the surface of the surface layer 6 and the heat-resistant resin 63 adhered to the surface is removed. Since the degree of crystallinity is high, the surface of the surface layer 6 becomes hard. Therefore, the hot-press cushion material 1 does not adhere to the press plate, and the releasability from the press plate is further improved.

The porosity of the woven or knitted fabric 60 constituting the surface layer 6 is 10 to 80%, and the impregnation amount of the heat-resistant resin 63 is 100 to 200 g / m ² . Thereby, the porosity of the woven or knitted fabric 60 having the woven yarn (warp 61 and weft 62) composed of the heat-resistant fiber member constituting the surface layer 6 is adjusted to such an extent that unevenness is formed on the surface. The impregnation amount of the resin 63 can be adjusted so as to be impregnated into the interior of the fiber member and adhere to the surface of the woven or knitted fabric 60 with such a small thickness that the surface irregularities are not covered.

  Further, although the surface layer 6 has a large surface roughness and many gaps are present in the surface layer 6, the anchor effect of the heat-resistant resin impregnated in the surface layer 6 and the rubber layer 4 laminated inside the surface layer 6 is obtained. Thereby, the rubber of the rubber layer 4 penetrates into the gaps of the surface layer 6, and the gaps of the surface layer 6 are closed to block the air flow, thereby increasing the airtightness and enabling the suction conveyance. Furthermore, since the weaving density of the woven fabric 60 used for the surface layer 6 is small and the amount of the heat-resistant resin is small, the hardness of the cushioning material for hot pressing is low, and the surface layer 6 has flexibility and warps the object to be pressed. Can be prevented from occurring.

  As described above, the embodiments of the present invention have been described based on the drawings. However, it should be considered that the specific configuration is not limited to these embodiments and examples. The scope of the present invention is defined not only by the description of the above-described embodiments and examples, but also by the appended claims, and further includes all modifications within the meaning and scope equivalent to the appended claims.

  In the present embodiment, the surface layer 6 is formed of the fabric 60, but is not limited thereto. The surface layer 6 may be composed of a knitted fabric knitted with a yarn made of a heat-resistant fiber member. In this case, the "woven yarn" in the above description corresponds to the "yarn". The knitted material constituting the surface layer 6 is formed such that the diameter of the yarn is 300 to 600 μm and the knitting density is 25 to 100 yarns / in.

  In the present embodiment, the hot-press cushion material 1 is disposed so as to be in close contact with the press platen 20 during hot-pressing, but is not limited thereto. For example, at the time of hot pressing, a mirror plate or the like may be arranged between the press board 20 and the hot-press cushion material 1. That is, the hot-press cushion material 1 may be arranged so as to be in close contact with a mirror plate or the like interposed between the press plates 20.

[Material for cushioning material for hot press]
In Examples and Comparative Examples, as the hot-press cushion material 1 according to the present embodiment shown in FIG. 2, three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4 are provided. The hot-press cushion material 1 composed of the laminated body 2 and the two surface layers 6 laminated on the surface of the laminated body 2 was used.

  As the unvulcanized rubber sheet used for the rubber layer 4, an unvulcanized rubber sheet having an average thickness of 0.2 mm made of a polyol cross-linked fluororubber composition (Viton (registered trademark) V9006 manufactured by DuPont) was used. A double-woven glass cloth (KS4325 manufactured by Nitto Bo) made of crimped fiber was used as the multi-woven cloth used in the mid layer 5. In addition, as the woven fabric 60 impregnated with the heat-resistant resin 63 used for the surface layer 6, a PTFE-impregnated glass cloth (satin weave) was used. Here, the PTFE-impregnated glass cloth is a glass cloth obtained by impregnating a woven fabric (cloth) woven with a woven yarn (warp 61 and weft 62) using glass fiber as a base material with a fluororesin. Since the glass fiber is excellent in heat resistance, high in strength and high in elasticity, and is impregnated with a fluororesin, the surface layer 6 excellent in heat resistance and low compression set can be formed. In this embodiment, a plurality of types of glass cloths having different diameters, weaving densities, and impregnation amounts of PTFE are used as the surface layer 6. The rubber layer 4, the intermediate layer 5 and the surface layer 6 are laminated and left in a normal press vulcanizer at a temperature of 170 ° C. for 12 minutes under no pressure, and the surface pressure is increased to 1.6 MPa at the same temperature. The cushioning material for hot pressing 1 of the example and the comparative example (2 m) was press-vulcanized under the condition of a press time of 12 minutes, and a plurality of types of glass cloths having different weaving densities and PTFE impregnation amounts were used as the surface layer 6. × 1 m).

[Evaluation test of suction conveyance property, releasability from press board, and flexibility when the diameter, weave density, and PTFE impregnation amount of the glass cloth of the surface layer are changed]
First, with respect to the cushioning material 1 for hot press of Comparative Examples 1 to 15, the suction conveyance property when the diameter, the weaving density, and the PTFE impregnation amount of the glass cloth of the surface layer 6 were changed, and the release from the press platen An evaluation test of the properties and flexibility was conducted. In the cushioning materials 1 for hot press of Comparative Examples 1 to 15, the heat treatment temperature at the time of PTFE impregnation of the PTFE-impregnated glass cloth used as the surface layer 6 was 350 ° C.

(Measurement test of surface layer)
With respect to the cushioning material 1 for hot pressing of Comparative Examples 1 to 15, the diameter, the weaving density, the PTFE impregnation amount, and the surface roughness Ra of the surface layer 6 of the glass cloth used for the surface layer 6 were measured. Here, the diameter of the weaving yarn of the glass cloth was calculated by taking a photograph of the glass fiber from one glass cloth, calculating the diameter of one glass weaving yarn from the average value of the short diameter and the long diameter, and calculating the diameter of the ten yarns. The average value was calculated from the diameter. The weaving density of the glass cloth was determined by measuring the weaving density of a sample having a side of 5 cm by a method in accordance with JIS L 1096, and calculating the value per unit inch (in). The PTFE impregnation amount of the glass cloth was measured by a weight change after heating at 650 ° C. using a simultaneous thermogravimetric differential analyzer. The surface roughness of the surface layer 6 was measured in a range of 40 mm at a speed of 2 mm / s by scanning the surface layer in the warp direction using a surface texture measuring device (SURF TEST500 manufactured by Mitutoyo Corporation, standard stylus model number 996133). The surface roughness Ra (arithmetic average roughness specified in JIS B 0031) was measured. Table 1 shows the measurement results of the weave density of the glass cloth used for the surface layer 6, the PTFE impregnation amount, and the surface roughness Ra of the surface layer 6 for the cushioning material 1 for hot press of Comparative Examples 1 to 15.

(Measurement test of cushioning material for hot press)
The porosity of the glass cloth without PTFE was determined for each of the cushioning materials 1 for hot pressing of Comparative Examples 1 to 15. Table 1 shows the calculation results of the porosity of the glass cloth for the cushioning material for hot press 1 of Comparative Examples 1 to 15. The porosity of the glass cloth was calculated according to the following procedure.
Cut out a sample of 10 cm on a side from the PTFE-impregnated glass cloth and measure the weight.
Calculate the weight of the glass cloth only from the difference between the measured weight and the PTFE impregnation amount.
-Multiply the area of the cut sample by the thickness to calculate the volume of the glass cloth.
-From the calculated volume of the glass cloth and the specific gravity of the glass fiber, calculate the weight when the porosity is 0%.
-The ratio occupied by the glass cloth is calculated from the calculated weight of only the glass cloth and the calculated weight in the case of the porosity of 0%, and the porosity is determined therefrom.

  The airtightness (air permeability) of the hot-press cushion material 1 of each of Comparative Examples 1 to 15 was measured. Here, the air permeability of the hot-press cushion material 1 was measured by a Frazier tester according to a method based on JIS R 3420 (2006). Table 1 shows the measurement results of the air permeability of the cushioning material for hot press 1 of the comparative example.

  Further, for the hot-press cushion material 1 of Comparative Examples 1 to 15, the total thickness of the hot-press cushion material 1 was measured. The average value of the total thickness of the cushioning material 1 for press was calculated from five points measured arbitrarily. Table 1 shows the measurement results of the total thickness of the cushioning material for hot press 1 of the comparative example.

  Further, with respect to the cushioning material for hot press 1 of Comparative Examples 1 to 15, the amount of deflection of the cushioning material for hot press 1 was measured. The amount of deflection was such that a 300 mm × 50 mm hot-press cushion material (test piece) was protruded by 250 mm, fixed with a presser plate, and the amount of sagging (flexure) of the protruding free end was measured. Table 1 shows the measurement results of the amount of deflection of the cushioning material for hot press 1 of the comparative example.

(Evaluation test of suction transferability, releasability from press board, flexibility)
Next, with respect to the cushioning material 1 for hot press of Comparative Examples 1 to 15, evaluation tests were performed to evaluate the suction conveyance property, the releasability from the press board, and the flexibility.

  In the evaluation test of the suction-conveying property, each of the cushioning materials 1 (2m × 1m) for each of the hot presses of Comparative Examples 1 to 15 is an automatic laminating device (a device for sucking and conveying the cushioning material for hot-pressing with a suction pad and laminating). ) And the like, and the suction conveyance property was evaluated based on whether the cushioning material for hot press 1 did not drop. In this evaluation, 20 suction pads were arranged side by side (except for the end (about 150 mm from the end) of the surface of the cushioning material 1 for hot press, and arranged at regular intervals) and sucked. Evaluation of the suction conveyance property was performed five times for each hot press cushion material. When all five times were conveyed during the suction conveyance, ◎, when the conveyance was not possible within five times, ○ In the case where no one of the five times was conveyed, it was judged in three stages of x.

  In the evaluation test of the releasability from the press plate, a 250 mm x 250 mm test piece was sandwiched between the press plates of a vacuum press tester and pressed to 4 MPa for each of the hot press cushion materials 1 of Comparative Examples 1 to 15. Then, the temperature was raised to 230 ° C. over 1 hour, held at 230 ° C. for 1 hour, cooled to 50 ° C. over 30 minutes, and then reduced to 0 MPa as one cycle, and this process was repeated 100 cycles. At that time, the releasability (100 cycles) from the press plate was evaluated based on whether the cushioning material for hot press 1 could be released without sticking to the press plate. The releasability (100 cycles) was evaluated on a three-point scale. If the hot-press cushion material 1 did not adhere to the press platen 20, the product was manually released even if the hot-press cushion material 1 adhered to the press plate 20. If it could be molded, it was evaluated as × if the hot-press cushion material 1 was stuck to the press platen 20 and could not be released manually. In addition, the releasability from the press plate (200 cycles) was evaluated based on whether or not the cushioning material 1 for hot press was released without sticking when the above process was repeated 200 cycles. The releasability (200 cycles) was evaluated in two stages, and was evaluated as ○ if the hot-press cushion material 1 did not adhere to the press platen 20 and × if the hot-press cushion material 1 adhered to the press plate 20. .

  In the evaluation test of flexibility, when each of the cushioning materials 1 for hot press of Comparative Examples 1 to 15 is used, the presence or absence of warpage of the press target is evaluated based on whether or not the press target is warped. The flexibility was evaluated based on the degree of warpage of the pressed object. The flexibility is evaluated in three stages. If the object to be pressed does not warp, ○, the object to be pressed is warped, and if the degree of warpage is small, the object to be pressed is warped, warping If the degree of is large, it was evaluated as x.

  Table 1 shows the evaluation results of the suction-conveying property, the releasability from the press platen, and the flexibility of the cushioning material 1 for hot press of Comparative Examples 1 to 15.

Based on the results in Table 1, the relationship between the air permeability, the amount of deflection, and the surface roughness of the hot-press cushion material 1 and the suction-conveying property was examined. As a result, the cushioning material 1 for hot press of Comparative Examples 1 to 6, 9, 11 to 13, and 15 having almost no air permeability of 1.0 cm ³ / cm ² · s or less can be suctioned and conveyed. Turned out to be high. On the other hand, the cushioning material 1 for hot press of Comparative Examples 7, 8, 10, and 14 having a permeability of more than 1.0 cm ³ / cm ² · s cannot be suctioned and conveyed, and is found to have low suction conveyance. Was. Further, it was found that the cushioning material for hot press 1 of Comparative Example 7, in which the amount of deflection was 150 mm or more, could not be conveyed by suction and had low suction conveyability. In addition, it was found that the cushioning material 1 for hot press of Comparative Examples 7, 8, 10, and 14 having a surface roughness Ra larger than 60 μm could not be conveyed by suction, and had low suction conveyability. Based on the results, the hot press cushion materials 1 of Comparative Examples 1 to 15 were examined. Then, the cushioning material 1 for hot pressing of Comparative Examples 1 to 6, 9, 11 to 13, and 15 has a minimum value of the diameter of the woven yarn of the glass cloth of 300 μm or more, or a woven density of the glass cloth of the warp and the weft. Both are at least 25 fibers / in, and the PTFE impregnation amount is at least 100 g / m ² , and it is considered that the impregnation into the inside of the woven yarn and the adhesion of the surface of the woven fabric are appropriate, and the airtightness is excellent. It is assumed that the air permeability is almost lost. In this specification, "the impregnation into the woven yarn and the adhesion of the surface of the woven fabric are appropriate" means that the heat-resistant resin 63 is impregnated into the woven yarn (the warp 61 and the weft 62), and Means that the woven yarns (the warp yarns 61 and the weft yarns 62) intersect and adhere to the surface of the woven fabric 60 with such a thickness as not to cover the unevenness formed on the surface. On the other hand, the cushioning material 1 for hot pressing of Comparative Examples 7 and 8 has a porosity of 80% or less, but has a small PTFE impregnation amount of less than 100 g / m ² , impregnating the inside of the woven yarn and the surface of the woven fabric. It is assumed that the adhesion is insufficient, the airtightness is low, the surface roughness Ra is too coarse, and the air permeability is high. The hot-press cushion material 1 of Comparative Example 10 had a low weave density of glass cloth of less than 25 yarns / in for both warp and weft, and the hot-press cushion material 1 of Comparative Example 14 had a weave of glass cloth. Since the diameter of the yarn is as small as less than 300 μm and the porosity is more than 80%, it is considered that a large gap is formed between the woven yarns, the airtightness is low, the surface roughness Ra is too coarse, and the airflow is low. Is likely to be higher. Furthermore, since the cushioning material 1 for hot press of Comparative Example 7 has a PTFE impregnation amount of 0 g / m ² , the amount of deflection of the cushioning material 1 for hot press is large, and the cushioning material 1 for hot press is largely bent. It is assumed that the surface layer 6 could not be sucked and held by the automatic laminating apparatus.

Further, based on the results in Table 1, the relationship between the surface roughness Ra of the surface layer 6 and the releasability (100 cycles) from the press plate was examined. As a result, the hot-press cushion materials 1 of Comparative Examples 1 to 8, 10, and 14 having a surface roughness Ra of 20 μm or more did not adhere to the press plate even after repeated use for 100 cycles, and the releasability from the press plate. (100 cycles) was found to be high. On the other hand, the cushioning material 1 for hot press of Comparative Examples 11 and 12 having a surface roughness Ra of 10 μm or more and less than 20 μm was stuck to the press plate, but could be peeled off when pulled with a force, and was evaluated as Δ. It was found that the releasability (100 cycles) from the press plate was not sufficiently high. In addition, the cushioning material 1 for hot press of Comparative Examples 9, 13, and 15 having a surface roughness Ra of less than 10 μm was completely stuck to the press plate and could not be peeled off. It was found that the releasability (100 cycles) was low. Based on the results, the hot press cushion materials 1 of Comparative Examples 1 to 15 were examined. Then, in the cushioning material 1 for hot pressing of Comparative Examples 1 to 8, 10, and 14, the porosity of the glass cloth is 10% or more (that is, the diameter of the maximum woven yarn of the glass cloth is 600 μm or less, or the glass cloth is And the PTFE impregnation amount is 200 g / m ² or less, and it is considered that the impregnation inside the woven yarn and the adhesion of the surface of the woven fabric are appropriate. It is assumed that the surface roughness Ra is rough and the releasability (100 cycles) from the press platen is high. On the other hand, in the cushioning material 1 for hot press of Comparative Examples 11 and 12, the weaving density of the glass cloth is more than 100 yarns / in for both the warp and the weft, and the porosity is as small as less than 10%. It is considered that the density is too high, the surface roughness Ra is high, and the releasability (100 cycles) from the press plate is not sufficiently high. Further, in the cushioning material for hot press 1 of Comparative Examples 9, 13, and 15, the PTFE impregnation amount of the glass cloth is more than 200 g / m ² , and the irregularities formed on the surface of the fabric 60 are crushed. It is assumed that the surface roughness Ra is too dense, and the releasability (100 cycles) from the press plate is low.

  Further, based on the results in Table 1, the relationship between the surface roughness Ra of the surface layer 6 and the releasability (200 cycles) from the press plate was examined. As a result, any of the cushioning materials for hot press 1 of Comparative Examples 1 to 15 stuck to the press plate without having 200 cycles. Based on the results, the hot press cushion materials 1 of Comparative Examples 1 to 15 were examined. Then, irrespective of the surface roughness Ra of the surface layer 6, any one of the cushioning materials for hot press 1 of Comparative Examples 1 to 15 has a heat treatment temperature at the time of PTFE impregnation of the PTFE-impregnated glass cloth used as the surface layer 6. This is probably because the temperature was 350 ° C. That is, since the heat treatment temperature at the time of PTFE impregnation of the PTFE-impregnated glass cloth used as the surface layer 6 is 350 ° C., the heat-resistant resin It is considered that organic components having high adhesiveness such as a dispersing agent added when impregnating with water could not be sufficiently removed.

Further, based on the results in Table 1, the relationship between the amount of deflection of the hot-press cushion material 1 and the flexibility of the hot-press cushion material 1 was examined. As a result, the hot-pressed cushion material 1 of Comparative Examples 1 to 8, 10, 11, and 14 in which the amount of deflection is 5 mm or more can be pressed even if the hot-pressed cushion material 1 is pressed. No warpage was observed, indicating that the flexibility was high. On the other hand, when the cushioning material 1 for hot pressing of Comparative Examples 9, 12, 13, and 15 in which the amount of deflection is less than 5 mm is pressed using the cushioning material 1 for hot pressing, the object to be pressed is warped. Was found, indicating that the flexibility was low. Based on the results, the hot press cushion materials 1 of Comparative Examples 1 to 15 were examined. Then, in the cushioning material 1 for hot pressing of Comparative Examples 1 to 8, 10, 11, and 14, the porosity of the glass cloth is 10% or more (that is, the maximum value of the diameter of the woven yarn of the glass cloth is 600 μm or less, or If the weave density of the glass cloth is 100 yarns / in or less for both the warp and the weft, and the PTFE impregnation amount is 200 g / m ² or less, the impregnation inside the woven yarn and the adhesion of the surface of the woven fabric are appropriate. It is conceivable that the object to be bent is appropriately bent at the time of pressing, so that the object to be pressed is not warped and the flexibility is high. On the other hand, the cushioning material for hot pressing 1 of Comparative Examples 9, 13, and 15 has a PTFE impregnation amount of more than 200 g / m ² , and the woven fabric 60 itself is considered to be hardened by PTFE which is a heat-resistant resin. Since it does not bend appropriately, it is assumed that the press object is warped and the flexibility is low. In the cushioning material 1 for hot pressing of Comparative Example 12, the weaving density of the glass cloth is more than 100 yarns / in, and it is considered that the space between the yarns is too dense, so that the fabric does not bend properly during pressing. Therefore, it is assumed that the press target is warped and the flexibility is low.

  In addition, when each sample of the cushioning material 1 for hot press of Comparative Examples 1 to 15 was used, it was confirmed whether or not there was any change in appearance and physical properties other than warping of the pressing object, but no difference was found. .

(Study on evaluation test of suction conveyance property, releasability from press board, flexibility)
From the above-described evaluation tests of the suction conveyance property, the releasability from the press platen, and the flexibility, the following became clear.

According to the results of the evaluation test of the suction conveyance property, the air permeability of the hot-press cushion material 1 is 1.0 cm ³ / cm ² · s or less, the deflection amount is 150 mm or less, and the surface roughness Ra is 60 μm or less. Then, it was confirmed that the sample was excellent in the suction conveyance property. In addition, it was confirmed that when the porosity of the glass cloth exceeded 80%, the glass cloth did not have suction transportability. For this purpose, the minimum value of the diameter of the woven yarn of the glass cloth of the cushion material 1 for hot pressing is 300 μm or more, or the weave density is 25 yarns / in or more for both the warp and the weft, and the PTFE impregnation amount is 100 g / in. It was confirmed that it was sufficient to be at least m ² .

Also, from the results of the evaluation test of the releasability from the press plate, if the surface roughness Ra of the surface layer 6 of the cushioning material for hot press 1 is 20 μm or more, the releasability from the press plate (100 cycles) is obtained. It was confirmed that it was excellent. Further, it was confirmed that when the porosity of the glass cloth was less than 10%, the releasability from the press plate (100 cycles) was not satisfied. For this purpose, the maximum value of the diameter of the woven yarn of the glass cloth of the cushioning material 1 for hot press is 600 μm or less, or the weave density of the glass cloth is 100 yarns / in or less for both the warp and the weft, and the PTFE impregnation amount is It was confirmed that 200 g / m ² or less was sufficient.

Further, from the result of the flexibility evaluation test, it was confirmed that if the deflection amount of the hot-press cushion material 1 was 5 mm or more, the object to be pressed was not warped and the flexibility was high. For this purpose, the maximum value of the diameter of the woven yarn of the glass cloth of the cushioning material 1 for hot press is 600 μm or less, or the weave density of the glass cloth is 100 yarns / in or less for both the warp and the weft, and the PTFE impregnation amount is It was confirmed that 200 g / m ² or less was sufficient.

As described above, in order to be able to perform suction conveyance, to have good releasability (100 cycles) from a press board or the like, and not to cause warpage of the object to be pressed, the air permeability of the hot-press cushion material 1 must be adjusted. 1.0 cm ³ / cm ² · s or less, the surface roughness Ra of the surface layer 6 is 20 μm or more and 60 μm or less, and the amount of deflection of the hot-press cushion material 1 is 5 to 150 mm. What is necessary is just to form the cushion material 1. Accordingly, the porosity of the glass cloth is 10 to 80% (that is, the diameter of the woven yarn of the glass cloth is 300 to 600 μm, and the woven density of the glass cloth is 25 to 100 yarns / in for both the warp and the weft), And it became clear that the cushioning material 1 for hot press should just be formed so that PTFE impregnation amount may be 100-200 g / m < ² >.

  However, in the cushioning material 1 for hot press of Comparative Examples 1 to 15 shown in Table 1, since the correlation between the surface roughness Ra and the suction conveyance property has not been sufficiently studied, the surface roughness Ra was changed in the following. Then, the correlation with the suction conveyance property is examined. In addition, none of the cushioning materials 1 for hot pressing of Comparative Examples 1 to 15 shown in Table 1 satisfy the releasability (200 cycles) from the press plate, so that the PTFE-impregnated glass used as the surface layer 6 will be described below. The correlation with the releasability (200 cycles) from the press plate is verified by changing the heat treatment temperature during the PTFE impregnation of the cloth.

[Evaluation Test of Suction Conveyability when Changing Surface Roughness Ra of Surface Layer]
Then, the correlation between the surface roughness Ra of the surface layer 6 and the suction conveyance property was verified for the cushioning material 1 for hot press of Comparative Example 1 and Comparative Examples 16 to 19. In addition, as for the cushioning material 1 for hot press of Comparative Examples 16 to 19, first, the press time for compressing the same glass cloth as that used as the surface layer 6 of Comparative Example 1 by sandwiching it between the press plates was changed. Thus, four types of glass cloths having different surface roughness were produced. The surface roughness of these four types of glass cloth was varied so that the surface roughness Ra of the surface layer 6 was smaller than that of the cushioning material 1 for hot pressing of Comparative Example 1. Thereafter, using the four types of glass cloth as the surface layer 6, the cushioning material 1 for hot press of Comparative Examples 16 to 19 was produced in the same manner as in Comparative Example 1. The surface roughness of the surface layer 6 of the hot-press cushion material 1 of Comparative Examples 16 to 19 was measured using a surface texture measuring device (SURF TEST500 manufactured by Mitutoyo Corporation, standard stylus model number) after the hot-press cushion material 1 was manufactured. Using 996133), the surface layer 6 was traced in the warp direction, a range of 40 mm was measured at a speed of 2 mm / s, and the surface roughness Ra (arithmetic average roughness specified in JIS B 0031) was measured.

(Evaluation test of suction transferability)
In order to easily evaluate the suction conveyance property, a simple suction test was performed using a simple suction device in which a suction pad (model PCG-30) for suction evaluation was attached to an aspirator (MDA-015 manufactured by ULVAC). . First, in order to clarify the standard of the suction force, the simple suction device is suctioned to a stainless steel flat plate having a surface roughness Ra of 5 μm or less so that the vacuum gauge becomes 0.02 MPa. Adjusted the power. Subsequently, a simple suction test was performed on each of the cushioning materials 1 for hot pressing of Comparative Example 1 and Comparative Examples 16 to 19, and the value of a vacuum gauge was recorded, which was used as an index of the suction force.

  Then, as an evaluation test of the suction conveyance property, each of the cushioning materials 1 for hot pressing of Comparative Example 1 and Comparative Examples 16 to 19 is transported and laminated by sucking the cushioning material for hot pressing with a suction pad. ) And the like, and the suction conveyance property was evaluated based on whether the hot-press cushion material 1 did not fall. Evaluation of the suction conveyance property was performed five times for each hot press cushion material. When all five times were conveyed during the suction conveyance, ◎, when the conveyance was not possible within five times, ○ In the case where no one of the five times was conveyed, it was judged in three stages of x.

(Evaluation test for releasability from press machine)
In addition to the correlation between the surface roughness Ra and the suction conveyance property, the correlation between the surface roughness Ra and the releasability of the press plate was also evaluated. In the evaluation test of the releasability with the press plate, a test piece of 250 mm × 250 mm was sandwiched between the press plates of a vacuum press tester for each of the cushioning materials 1 for hot press of Comparative Example 1 and Comparative Examples 16 to 19, After increasing the pressure to 4 MPa, the temperature is raised to 230 ° C. over 1 hour, maintained at 230 ° C. for 1 hour, cooled to 50 ° C. over 30 minutes, and reduced to 0 MPa as one cycle. Was repeated for 100 cycles, the releasability (100 cycles) from the press plate was evaluated based on whether the cushioning material for hot press 1 could be released without being stuck to the press plate. The evaluation of the releasability from the press board (100 cycles) was performed in three stages. If the hot-press cushion material 1 did not stick to the press board 20, the heat-resisting cushion material 1 stuck to the press board 20. When the mold release could be manually performed, the evaluation was evaluated as “△”. When the cushioning material for hot press 1 was stuck on the press platen 20 and could not be manually released, the evaluation was evaluated as “x”.

  Table 2 shows the results of the simple suction test, the suction conveyance property, and the releasability of the cushion material 1 of Comparative Example 1 and Comparative Examples 16 to 19 from the press platen.

  Based on the results in Table 2, the correlation between the surface roughness Ra of the surface layer 6 and the suction transferability when the surface roughness Ra of the surface layer 6 was changed was examined. As a result, Comparative Examples 18 and 19 in which the surface roughness Ra was 50 μm or less were more excellent in suction conveyance properties than Comparative Examples 1, 16 and 17 in which the surface roughness Ra was 50 μm to 60 μm.

  Further, based on the results in Table 2, the correlation between the surface roughness Ra of the surface layer 6 when the surface roughness Ra of the surface layer 6 was changed and the releasability from the press plate was examined. As a result, Comparative Examples 16 to 19 in which the surface roughness Ra was 20 μm or more were excellent in the releasability from the press plate, as in Comparative Example 1.

(Study on evaluation test of suction transferability and release property from press machine)
From the evaluation test of the suction conveyance property and the releasability of the press layer when the surface roughness Ra of the surface layer 6 was changed, the following became clear.

  When the surface roughness Ra of the surface layer 6 is set to 20 μm or more in the same manner as the result of the evaluation test of the releasability with the press plate shown in Table 1 from the result of the evaluation test of the releasability with the press plate, It was confirmed that there was no problem in the releasability from the press board.

  Further, from the result of the evaluation test of the suction conveyance property, it is found that the surface layer 6 has the suction conveyance property when the surface roughness Ra is 60 μm or less. Furthermore, by finishing the surface roughness Ra of the surface layer 6 to 50 μm or less, a high airtightness is sufficiently secured between the surface layer and the suction pad of the suction transfer device, and a stable suction transfer can be realized. It can be seen that it has a suction conveyance property.

  From the above, the surface roughness Ra of the surface layer 6 is 20 to 60 μm, especially the surface roughness Ra of the surface layer 6 is 20 to 50 μm in order to achieve both the releasability from the press plate and the suction conveyance property. It has been found that a certain range is a more preferable range.

  However, in the cushioning material 1 for hot press of Comparative Examples 16 to 19 shown in Table 2, since the releasability from the press plate was evaluated only in 100 cycles, the PTFE impregnation used as the surface layer 6 will be described below. The correlation between the heat treatment temperature during the PTFE impregnation of the glass cloth and the releasability (200 cycles) from the press plate is verified.

[Evaluation test of suction transferability, releasability from press plate, and flexibility when heat treatment temperature of surface layer is changed]
Further, with respect to the cushioning material 1 for hot pressing of Examples 1 to 3 and Comparative Example 1, the heat treatment temperature when the surface layer 6 was impregnated with a heat-resistant resin was changed to obtain a press plate such as a press plate. The correlation with the mold releasability (200 cycles) was verified. Therefore, based on the cushioning material 1 for hot press of Comparative Example 1, the three types of heat presses of Examples 1 to 3 in which the heat treatment temperature at the time of PTFE impregnation of the PTFE impregnated glass cloth used as the surface layer 6 was changed. Cushion material 1 was produced. The heat treatment temperature was 400 ° C. for the hot-press cushion material 1 of Example 1, 380 ° C. for the hot-press cushion material 1 of Example 2, and 360 ° C. for the hot-press cushion material 1 of Example 3. For comparison, a cushioning material 1 for hot pressing of Comparative Example 1 was also prepared. The heating temperature of the hot-press cushion material 1 of Comparative Example 1 is 350 ° C. as described above. In addition, an evaluation test of suction transportability and flexibility was also performed.

(Measurement test of surface layer)
About the glass cloth used as the surface layer 6 of the cushioning material 1 for hot press of Examples 1 to 3 and Comparative Example 1, the temperature was changed from 40 ° C. to 420 at a heating rate of 10 ° C./min under a nitrogen atmosphere by a differential scanning calorimeter (DSC). In a melting curve measured in a temperature range up to ° C., a heat of fusion calculated from a melting peak temperature appearing near the melting point of the heat-resistant resin 63 was measured. Further, with respect to the glass cloth used as the surface layer 6 of the hot-press cushion material 1 of Examples 1 to 3 and Comparative Example 1, the crystallinity of the surface measured by the X-ray diffraction method was calculated. As described above, the calculation is performed using, for example, the θ-2θ method of the X-ray diffraction method. Table 3 shows the measurement results of the heat of fusion and the crystallinity of each of the cushioning materials 1 for hot pressing of Examples 1 to 3 and Comparative Example 1.

(Measurement test of cushioning material for hot press)
The surface hardness, airtightness (air permeability), and the amount of deflection of the hot-press cushion material 1 of Examples 1 to 3 and Comparative Example 1 were measured, respectively. In addition, the diameter, weaving density, porosity, PTFE impregnation amount, and surface roughness of the surface layer 6 of the glass cloth used for the surface layer 6 of the cushioning material 1 for hot press in Examples 1 to 3 and Comparative Example 1 About Ra, it is the same as the measurement result of the cushioning material 1 for hot press of the comparative example 1 mentioned above, and the description was omitted. Table 3 shows the measurement results of the air permeability and the amount of deflection of the hot-press cushion material 1 of the hot-press cushion materials 1 of Examples 1 to 3 and Comparative Example 1.

(Evaluation test of suction transferability, releasability from press board, flexibility)
Next, each of the cushioning materials 1 for Examples 1 to 3 and Comparative Example 1 was subjected to an evaluation test for evaluating the releasability from a press board.

  In the evaluation test of the suction-conveying property, an automatic laminating device (a device for sucking and transporting the hot-press cushion material with a suction pad, and laminating each of the hot-press cushion materials 1 (2 mx 1 m) of the examples and comparative examples). ) And the like, and the suction conveyance property was evaluated based on whether the cushioning material for hot press 1 did not drop. Evaluation of the suction conveyance property was performed five times for each hot press cushion material. When all five times were conveyed during the suction conveyance, ◎, when the conveyance was not possible within five times, ○ In the case where no one of the five times was conveyed, it was judged in three stages of x.

  In the evaluation test of the releasability from the press plate, a 250 mm × 250 mm test piece was sandwiched between the press plates of a vacuum press tester and pressurized to 4 MPa for each hot press cushion material 1 of the example and the comparative example. After that, the temperature was raised to 230 ° C. over 1 hour, held at 230 ° C. for 1 hour, cooled to 50 ° C. over 30 minutes, and reduced to 0 MPa as one cycle, and this process was repeated 200 cycles. At that time, the releasability from the press plate was evaluated based on whether or not the cushioning material for hot press 1 was released without sticking. The evaluation of the releasability from the press board was performed in two stages. In the process of repeating 200 cycles, if the hot-press cushion material 1 was not stuck on the press board 20 even once, × if it was pasted even once.

  Incidentally, the evaluation test of the releasability with the press plate is the same as the evaluation test (200 times) of the releasability with the press plate performed on Comparative Examples 1 to 13 shown in Table 1 described above. That is, in the evaluation test (100 times) of the releasability with the press plate determined under the loose condition performed on the comparative examples 1 to 13 shown in Table 1 described above, Comparative Examples 1 to 8 and Comparative Examples 10 to 12 And 14 were hot or soft, but in the evaluation test (200 times) of releasability with a press board determined under severe conditions, This is to consider that has become ×. Therefore, in order to evaluate whether or not the heat treatment temperature of the PTFE-impregnated glass cloth used as the surface layer 6 at the time of the PTFE impregnation processing was set to 350 ° C. had a relationship with the releasability from the press platen, the surface layer 6 was used. An evaluation test (200 times) was performed on the cushioning material 1 for hot press of Examples 1 to 3 in which the heat treatment temperature during the PTFE impregnation of the PTFE-impregnated glass cloth used as the material was changed. And the releasability from the press board were evaluated.

  In the evaluation test of flexibility, when each of the cushioning materials for hot press 1 (2 m × 1 m) of the example and the comparative example is used, the warpage of the press target is determined based on whether the press target is warped. The presence or absence was evaluated, and the flexibility was evaluated based on the degree of warpage of the press target. The flexibility is evaluated in three stages. If the object to be pressed does not warp, ○, the object to be pressed is warped, and if the degree of warpage is small, the object to be pressed is warped, warping If the degree of is large, it was evaluated as x.

  Table 3 shows the evaluation results of the suction conveyance property, the releasability from the press platen, and the flexibility of the cushioning material 1 for hot press of Examples 1 to 3 and Comparative Example 1.

  Based on Table 3, a correlation was found between the heat treatment temperature during the PTFE impregnation processing, the crystallinity, and the heat of fusion. Specifically, the glass cloth of the cushioning material for hot pressing 1 of Example 1 in which the heat treatment temperature was 400 ° C. had the highest crystallinity of 86% and the heat of fusion energy of 5.60 mJ / mg. Further, the glass cloth of the cushioning material for hot pressing 1 of Example 2 in which the heat treatment temperature was 380 ° C. had a crystallinity of 84% and a heat of fusion of 4.42 mJ / mg. Further, the glass cloth of the cushioning material for hot press 1 of Example 3 in which the heat treatment temperature was 360 ° C. had a crystallinity of 81% and a heat of fusion of 4.13 mJ / mg. The cushioning material 1 for hot press of each of Examples 1 to 3 was excellent in all of the suction conveyance property, the releasability from the press board, and the flexibility. On the other hand, the glass cloth of the cushioning material for hot pressing 1 of Comparative Example 1, in which the heat treatment temperature was 350 ° C., had the lowest crystallinity of 74% and the heat of fusion of 3.86 mJ / mg. The cushioning material for hot press 1 of Comparative Example 1 had good suction-conveying properties, but had insufficient releasability from the press plate due to sticking to the press plate 20.

(Study on evaluation test of suction conveyance property, releasability from press board, flexibility)
From the above-described evaluation tests of the suction conveyance property, the releasability from the press platen, and the flexibility, the following became clear.

As described above, the air permeability of the hot-press cushion material 1 is 1.0 cm ³ / cm ² · s or less even when the heat treatment temperature of the surface layer is changed from the evaluation test of the suction conveyance property, even when the heat treatment temperature of the surface layer is changed. If the amount of deflection was 150 mm or less and the surface roughness Ra was 60 μm or less, it was confirmed that the sheet was excellent in suction conveyance properties. For this purpose, the minimum value of the diameter of the woven yarn of the glass cloth of the cushion material 1 for hot pressing is 300 μm or more, or the weave density is 25 yarns / in or more for both the warp and the weft, and the PTFE impregnation amount is 100 g / in. It was confirmed that it was sufficient to be at least m ² . Also, according to the flexibility evaluation test, even if the heat treatment temperature of the surface layer is changed, as described above, if the amount of deflection of the hot-press cushion material 1 is 5 mm or more, the object to be pressed is warped. Was not seen, and it was confirmed that the flexibility was high. For this purpose, the maximum value of the diameter of the woven yarn of the glass cloth of the cushioning material 1 for hot press is 600 μm or less, or the weave density of the glass cloth is 100 yarns / in or less for both the warp and the weft, and the PTFE impregnation amount is It was confirmed that 200 g / m ² or less was sufficient.

  From the result of the evaluation test of the releasability with the press plate, the cushioning material 1 for hot press using the glass cloth which has been subjected to the heat treatment in advance at the temperature of 360 to 430 ° C. as the surface layer 6 during the PTFE impregnation processing, It was confirmed that the releasability from the press machine was excellent. Thereby, by performing a heat treatment at a higher temperature than in the conventional case (350 ° C.), organic components having high adhesiveness such as a dispersant added when impregnating the surface layer 6 with PTFE are sufficiently removed. And the crystallinity of PTFE can be increased, the surface of the surface layer 6 can be formed harder, and the releasability from a press plate or the like can be maintained more favorably. Understand.

  Similarly, from the results of the evaluation test of the releasability with the press plate, the melting curve measured by a differential scanning calorimeter at a heating rate of 10 ° C./min in a temperature range from 40 ° C. to 420 ° C. under a nitrogen atmosphere. A glass having a heat of fusion of 4.0 mJ / mg or more calculated from a melting peak temperature appearing near the melting point of the heat-resistant resin, and a crystallinity of 80% or more as measured by X-ray diffraction on the surface. It was confirmed that the hot-press cushion material 1 using the cloth as the surface layer 6 was excellent in releasability from the press plate. Thereby, since the heat of fusion of the peak appearing near the melting point of PTFE is high, the organic component having high adhesiveness is removed without remaining on the surface of the surface layer 6, and the crystallinity of PTFE attached to the surface is high. It can be seen that the surface of the surface layer 6 becomes hard, the cushioning material for hot press 1 does not adhere to the press plate, and the releasability from the press plate is further improved.

  As described above, the embodiments of the present invention have been described based on the drawings. However, it should be considered that the specific configuration is not limited to these embodiments and examples. The scope of the present invention is defined not only by the description of the above-described embodiments and examples, but also by the appended claims, and further includes all modifications within the meaning and scope equivalent to the appended claims.

  By using the present invention, it is possible to provide a hot-press cushion material that can be suction-conveyed, has good releasability from a press board or the like, and does not cause warpage of an object to be pressed, and a method of manufacturing the same. it can.

DESCRIPTION OF SYMBOLS 1 Cushion material for hot press 2 Laminate 4 Rubber layer 5 Intermediate layer 6 Surface layer 60 Textile 61 Warp 62 Weft 63 Heat resistant resin

Claims (10)

A hot-press cushion material used by being interposed between a press board and a press target,
A laminate in which at least two rubber layers and an intermediate layer made of a multi-woven cloth interposed between the rubber layers,
A surface layer laminated on both sides of the outermost rubber layer of the laminate, comprising a woven or knitted fabric having a yarn made of a heat-resistant fiber member,
The surface layer has a heat-resistant resin impregnated inside the yarn and attached to the surface of the woven or knitted fabric with such a thickness that the yarn crosses and does not cover unevenness formed on the surface. A method for manufacturing a cushioning material for hot pressing,
The method for manufacturing a cushioning material for hot press, wherein the surface layer is formed by previously performing a heat treatment on the woven or knitted fabric impregnated with the heat-resistant resin at a temperature of 360 to 430 ° C. A hot-press cushion material used by being interposed between a press board and a press target,
A laminate in which at least two rubber layers and an intermediate layer made of a multi-woven cloth interposed between the rubber layers,
A surface layer laminated on both sides of the outermost rubber layer of the laminate, comprising a woven or knitted fabric having a yarn made of a heat-resistant fiber member,
The surface layer has a heat-resistant resin impregnated inside the yarn and attached to the surface of the woven or knitted fabric with such a thickness that the yarn crosses and does not cover unevenness formed on the surface. Further, in a melting curve measured at a heating rate of 10 ° C./min in a temperature range from 40 ° C. to 420 ° C. in a nitrogen atmosphere by a differential scanning calorimeter, the melting peak temperature appearing near the melting point of the heat-resistant resin is A cushioning material for hot pressing, wherein the calculated heat of fusion is 4.0 mJ / mg or more, and the crystallinity of the surface measured by an X-ray diffraction method is 80% or more. The hot press cushion according to claim ² , wherein the surface layer has a porosity of the woven or knitted fabric of 10 to 80% and an impregnation amount of the heat-resistant resin of 100 to 200 g / m2. Wood.   The hot press cushion according to claim 3, wherein the weaving density of the warp and the weft of the woven fabric or the knitting density of the knit is 25 to 100 yarns / in, and the diameter of the yarn is 300 to 600 m. Wood. The hot-press cushion material according to any one of claims 2 to 4, wherein the air permeability of the entire hot-press cushion material is 1.0 cm3 / cm2 · s or less. The hot-press cushion material according to any one of claims 2 to 5, wherein the deflection amount of the hot-press cushion material is 5 to 150 mm. The cushioning material for hot press according to any one of claims 2 to 6, wherein the surface roughness of the surface layer is an arithmetic average roughness Ra of 20 µm or more and Ra of 60 µm or less, more preferably Ra 50 µm or less. The cushioning material for hot press according to any one of claims 2 to 7, wherein the heat-resistant fiber member is a glass fiber. The cushioning material for hot press according to any one of claims 2 to 8, wherein the heat-resistant resin is a fluororesin. It is a manufacturing method of the cushioning material for hot press according to any one of claims 2 to 9,
The method for manufacturing a cushioning material for hot press, wherein the surface layer is formed by previously performing a heat treatment on the woven or knitted fabric impregnated with the heat-resistant resin at a temperature of 360 to 430 ° C.

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