JP6677833B2 - Cushion material for heat press - Google Patents

Description

  The present invention relates to a hot-press cushion material used between a hot press machine and an object to be pressed.

  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, in order to uniformly apply heat and pressure to the object to be pressed, a flat plate made of a cushion material for hot pressing and a mirror plate made of a stainless steel plate are interposed between the hot pressing plate and the object to be pressed. Be placed. 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 hot press board.

  The members used for the surface layer of the hot-press cushioning material include, in addition to the cushioning properties of the hot-pressing cushioning material, airtightness when suctioned and conveyed by an automatic laminating apparatus or the like, a hot-pressing plate after hot pressing. And properties such as releasability from the mirror surface plate and the like. 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 with 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. There is a problem that sticking occurs and the releasability from a hot press board or the like deteriorates. Further, when used repeatedly, as shown in FIG. 4 (b), the unevenness is crushed and the surface roughness is further reduced, so that it cannot be peeled off due to vacuum adhesion with a hot press plate or a mirror surface plate. There's a problem.

  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, and provides 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. The purpose is to provide.

  In order to solve the above problems, the cushioning material for hot pressing according to the present invention is a cushioning material for hot pressing used to be interposed between a hot press board and a pressing object, and has at least two rubber layers. A laminated body in which an intermediate layer composed of multiple woven cloths interposed between the rubber layers, and a laminated body laminated on the surface of the laminated body, and having a heat-resistant fiber member as a base material, forming irregularities on the surface A heat-resistant resin is impregnated into the interior of the fibrous member, and adheres to the surface of the woven fabric or knit with a thickness that does not cover the irregularities. It is characterized by having.

  According to the cushioning material for hot press of the present invention, the surface layer is made of a woven fabric or a knitted fabric having irregularities formed on the surface thereof based on the heat-resistant fiber member, and the heat-resistant resin is impregnated inside the fiber member. And adheres to the surface of the woven or knitted fabric with such a thickness as not to cover the unevenness of the surface. Due to this, the entire surface layer is not covered with the heat-resistant resin, and since there are many gaps in the surface layer, the surface roughness of the surface layer increases, and the releasability from a press plate or the like is improved. be able to. In addition, even after repeatedly using the cushioning material for hot press, since the unevenness of the surface layer is not easily lost, the releasability from the press plate or the like can be maintained favorably. 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 used by being interposed between a hot press board and an object to be pressed, wherein at least two rubber layers and the rubber layers An intermediate layer consisting of multiple woven cloths interposed therebetween, and a laminated body in which a laminate is laminated, and a heat-resistant fiber member is used as a base material, and a woven fabric or a knitted fabric that forms irregularities on the surface is laminated on the surface of the laminate. Wherein the heat-resistant resin is impregnated into the interior of the fibrous member and adheres to the surface of the woven fabric or knit with such a thickness as not to cover the irregularities. Alternatively, the porosity of the knitted fabric is 10 to 80%, and the impregnation amount of the heat-resistant resin is 100 to 200 g / m ² .

According to the cushioning material for hot press of the present invention, the porosity of a woven fabric or a knitted fabric based on the heat-resistant fiber member constituting the surface layer is adjusted to such an extent that irregularities are formed on the surface, and the heat resistance is improved. The amount of the resin impregnated is adjusted so that it is impregnated into the interior of the fiber member and adheres to the surface of the woven or knitted fabric with such a small thickness that does not cover the surface irregularities. Due to this, the entire surface layer is not covered with the heat-resistant resin, and since there are many gaps in the surface layer, the surface roughness of the surface layer increases, and the releasability from a press plate or the like is improved. be able to. In addition, even after repeatedly using the cushioning material for hot press, since the unevenness of the surface layer is not easily lost, the releasability from the press plate or the like can be maintained favorably. 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.
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-described cushioning material for hot press, the weaving density of the woven fabric or the knitted fabric is 10 to 30 yarns / cm for both the warp and the weft, and the fiber warp of the heat-resistant fiber member constituting the woven fabric or the knitted fabric is , 300 to 600 μm.
Since the porosity of a woven fabric or a knitted fabric changes depending on the woven density or the fiber diameter of the woven fabric or the knitted fabric, the woven density of the woven fabric or the knitted fabric is set to 10 to 30 yarns / cm for both the warp and the weft, and By adjusting the fiber diameter of the heat-resistant fiber member constituting the knitted fabric to 300 to 600 μm, the porosity of the woven fabric or the knitted fabric based on the heat-resistant fiber member constituting the surface layer is adjusted to 10 to 80%. can do.

In the cushioning material for hot press, the rubber layer may have a rubber hardness of 65 to 85 degrees.
By reducing the rubber hardness of the rubber layer, the rubber of the rubber layer easily penetrates into the gaps between the surface layers due to the anchor effect, and the airtightness can be secured by blocking the ventilation.

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 hardness of the cushioning material for hot press may be 90 degrees or less.
By setting the hardness of the entire hot-press cushion material to 90 degrees or less, the flexibility of the hot-press cushion material is provided, and it is possible to prevent the object to be pressed from warping.

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 the arithmetic average roughness Ra of 20 μm or more, the releasability from a press board 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 be Ra 20 or more and Ra 60 μm or less, and more preferably Ra 50 μm or less, it is possible to achieve both the peeling property and the suction conveyance property. 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.

  As described in the above description, according to the present invention, there is provided a cushioning material for hot press, which can be suctioned and conveyed, has good releasability from a press board or the like, and does not cause warpage of a press object. can do.

It is a key map explaining the hot press using the cushioning material for hot press concerning this embodiment. It is sectional drawing which shows the cushioning material for hot press which concerns on this embodiment. It is sectional drawing which shows the surface layer of the cushioning material for hot press which concerns on this embodiment, (a) shows the state before a press, (b) shows the state after using repeatedly for a press. It is sectional drawing which shows the surface layer of the cushioning material for hot press which concerns on a prior art, (a) shows the state before pressing, (b) shows the state after using repeatedly for a 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 an object to be pressed 21 is press-formed by a hot press board 20 using the hot-press cushion material 1 according to the present embodiment is shown.

  As shown in FIG. 1, two flat cushion members 1 are arranged between two hot press boards 20, and further, a press is performed between the two cushion members 1 via a stainless steel plate 22. An object 21 is arranged. That is, the cushion material 1 and the stainless steel plate 22 are interposed between the two hot press boards 20 and the press target 21, respectively. In this state, heat and pressure are applied by the hot press board 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 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 cushion material 1 is formed by laminating a rubber layer 4, an intermediate layer 5, and a surface layer 6. The cushioning material 1 according to the present embodiment includes a laminate 2 in which three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4 are laminated, and the surface of the laminate 2 (that is, And two surface layers 6 laminated on the intermediate layer 5 of the rubber layer 4 of the laminate 2 on the side opposite to the intermediate layer 5).

  That is, the cushioning material 1 is obtained by laminating 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 is. 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. The rubber hardness (JIS A) of the rubber composition is preferably from 65 to 85 degrees. By setting the rubber hardness of the rubber layer 4 to a relatively small value of 65 to 85 degrees, the rubber of the rubber layer 4 easily permeates into the gaps of the surface layer 6 due to the anchor effect, and shuts off ventilation to secure airtightness. Because you can do it. Examples of the type of the fluororubber include a fluoroacrylate polymer, a vinylidene fluoride copolymer, a fluorosilicon rubber, a fluoropolyester rubber, and the like.

  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.

  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 such a 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 made of a woven fabric 60 having a heat-resistant fiber member as a base material. In addition, in this embodiment, although the surface layer 6 is comprised by the woven fabric 60, it is not restricted to it, The surface layer 6 may be comprised by the knitted fabric which uses a heat resistant fiber member as a base material. 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 the surface of the surface layer 6 has irregularities. 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 (warp yarn 61 and weft yarn 62) becomes too dense, the surface roughness of the surface layer 6 is small, and the hardness of the cushion material 1 is small. From the viewpoint of the releasability and flexibility of the cushion material 1, which is not preferable. On the other hand, if the predetermined porosity of the woven fabric 60 is too large, a large gap is formed between the woven yarns, and the air permeability of the cushion material 1 increases, which is not preferable from the viewpoint of suction conveyance. 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 varies depending on the fiber diameter and the weaving density, the woven fabric 60 has a predetermined porosity so that the warp 61 and the weft 62 are heat-resistant fiber members having a predetermined fiber diameter. Are woven at a predetermined weave density. Here, if the fiber diameter is too large, the space between the yarns becomes too dense and the porosity decreases. If the fiber 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 predetermined fiber diameter is 300 to 600 μm. The predetermined weaving density is, for example, 10 to 30 yarns / cm 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 fabric 60. By forming the surface layer 6 of the cushion material 1 with the woven fabric 60 having a heat-resistant fiber member as a base material, the surface of the cushion material 1 is hardly damaged, so that it can be pressed uniformly. Particularly, as the heat-resistant fiber member serving as the base material of the woven fabric 60, glass fiber having excellent heat resistance, high strength, and high elasticity is preferable. When glass fiber is used for the heat-resistant fiber member serving as the base material of the woven fabric 60, the cushion material 1 to be molded has a certain degree of hardness. Also, it does not hang down by its own weight and does not drop from the suction / conveyance device, and the adhesive strength between the glass fiber and the heat-resistant resin is not weak as when using other heat-resistant fibers such as aramid fiber, and it adheres even at high temperatures. Because of the strong force, it can be used up to 260 ° C (it is assumed to be used in the range of 180 to 240 ° C in the present invention). Also, even in a high-temperature hot press, fibers are not deteriorated and fluff is generated. There is an advantage that it does not.

  The woven 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 melanin resin, a fluororesin, an unsaturated polyester resin, a silicone resin, a polyimide resin, a thermosetting acrylic resin, a furan resin, a urea resin, and a diallyl phthalate resin. , A blend system or a copolymer. Among them, a fluororesin having good heat resistance and low compression set is most preferable.

As shown in FIG. 3A, the heat-resistant resin 63 is impregnated into the yarns 61 and 62 of the woven fabric 60 and does not cover the irregularities formed on the surface of the woven fabric 60 ( Impregnation is performed at a predetermined impregnation amount so as to adhere thinly (to the extent that unevenness is maintained). Here, if the impregnation amount of the heat-resistant resin 63 is too small, impregnation into the interior of 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 air permeability of the cushion material 1 is insufficient. If it is too large, the irregularities formed on the surface of the woven fabric 60 will be crushed, and the surface roughness of the surface of the surface layer 6 will be small. Of the cushion material 1 is not preferable from the viewpoint of the releasability and flexibility of the cushion material 1. Therefore, the predetermined impregnation amount is an amount that impregnates the interior of the yarns 61 and 62 constituting the woven fabric 60 and does not cover the irregularities formed on the surface of the woven fabric 60, but adheres thinly enough to maintain the irregularities ( That is, as shown in FIG. 4A, the entire surface including the unevenness existing on the surface of the woven fabric 60 is not covered with the heat-resistant resin 63, but becomes the state shown in FIG. 3A. Volume). Specifically, the predetermined impregnation amount is, for example, 100 to 200 g / m ² .

  The impregnation of the woven fabric 60 with the heat-resistant resin 63 can be performed by a known method such as blade coating, knife coating, cast coating, or the like.

[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, a laminate 2 is formed by alternately laminating three rubber sheets as the rubber layers 4 and two multi-woven cloths as the intermediate layer 5 so that the rubber sheets are on the outside. Next, the surface of the laminate 2 is sandwiched between two woven fabrics 60 impregnated with a heat-resistant resin to be the surface layer 6, and press vulcanized under the conditions of a temperature of 150 to 180 ° C. and a press time of 10 to 40 minutes. And integrate them. Then, the cushion material 1 is cut into a size suitable for a predetermined hot press board.

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

  As described above, according to the cushioning material for hot press 1 according to the present embodiment, the porosity of the woven fabric 60 based on the heat-resistant fiber member constituting the surface layer 6 is reduced, and irregularities are formed on the surface. At the same time, the impregnation amount of the heat-resistant resin is adjusted to such an extent that the warp 61 and the weft 62 constituting the woven fabric 60 are attached to the inside and the surface of the woven fabric 60 so that there are many gaps in the surface layer 6. (See FIG. 3A). Thereby, since the entire surface layer 6 is not covered with the heat-resistant resin, the surface roughness of the surface layer 6 is increased, and the releasability from the press plate or the like can be improved. In addition, even after repeatedly using the hot-press cushion material 1, as shown in FIG. 3B, since the unevenness of the surface layer 6 is hard to disappear, it is possible to maintain good releasability from a press plate or the like. it can. 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 small, and the surface layer 6 has flexibility, so that Warpage can be prevented from occurring.

(Cushion material for hot press)
In the example, as the cushioning material 1 according to the present embodiment shown in FIG. 2, a laminated body 2 in which three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4 are laminated. And a cushion material 1 composed of two surface layers 6 laminated on the surface of the laminate 2.

  As the rubber composition used for the rubber layer 4, a fluororubber composition was used. Further, a double-fold glass cloth was used as the multi-woven cloth used in the mid layer 5. As the woven fabric 60 impregnated with the heat-resistant resin 63 used for the surface layer 6, a PTFE-impregnated glass cloth was used. Here, the PTFE-impregnated glass cloth is a glass cloth obtained by impregnating a glass fiber with a fluororesin. Since it is a glass fiber, it has excellent heat resistance, high strength and high elasticity, and since it is impregnated with a fluororesin, the surface layer 6 having excellent heat resistance and low compression set can be formed. In this example, a plurality of types of glass cloths having different fiber diameters, weaving densities, and PTFE impregnation amounts were used as the surface layer 6. These were laminated and left in a normal press vulcanizer at a temperature of 170 ° C. for 12 minutes under no pressure to crosslink the rubber material. Thereafter, the surface pressure was increased to 1.6 MPa at the same temperature, and these were vulcanized for 12 minutes, and Examples 1 to 6 and Comparative Examples in which a plurality of types of glass cloths having different weaving densities and PTFE impregnation amounts were used as the surface layer 6. Cushion materials 1 of Examples 1 to 9 were produced.

Then, for the cushion material 1 of the example and the comparative example, the fiber diameter, the weave 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 fiber diameter of the glass cloth was determined by taking a photograph of the glass fiber from one glass cloth, calculating the fiber diameter of one glass fiber from the average of the short diameter and the long diameter, and calculating the calculated fiber diameter of the ten fibers. The average value was calculated from. The weave density of the glass cloth was determined by measuring the weave 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 cm. 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 can be measured using a surface texture measuring device (SURF manufactured by Mitutoyo Corporation).
Using a TEST500, standard stylus model number 996133), the surface layer 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. . Table 1 shows the measurement results of the woven 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 cushion materials 1 of the examples and the comparative examples.

  Then, for each of the cushion materials 1 of the example and the comparative example, the porosity of the glass cloth excluding PTFE was determined. Table 1 shows the calculation results of the porosity of the glass cloth for the cushioning materials 1 of the examples and the comparative examples. 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 the glass cloth alone and the calculated weight in the case of the porosity of 0%, and the porosity is determined therefrom.

  In addition, the airtightness (air permeability) and hardness of the cushioning material 1 were measured for the cushioning materials 1 of the example and the comparative example. Here, the air permeability of the cushion material 1 was measured by a Frazier tester by a method based on JIS R 3420 (2006). The hardness of the cushion material 1 was measured with a type A hardness meter. Table 1 shows the measurement results of the air permeability and the hardness of the cushion materials 1 of the examples and the comparative examples.

[Evaluation test of suction conveyance property, peeling property and flexibility]
Next, with respect to the cushion materials 1 of the example and the comparative example, an evaluation test for evaluating the suction conveyance property, the peeling property, and the flexibility was respectively performed.

(Evaluation test of suction transferability)
In the evaluation test of the suction conveyance property, each cushion material 1 of the example and the comparative example is suction-conveyed by an automatic laminating device (a device for sucking and conveying the cushion material with a suction pad and laminating the cushion material), and the like. The suction transportability was evaluated based on whether or not the sample did not fall. Evaluation of the suction conveyance property was performed 5 times for each cushion material. When all 5 times were conveyed during suction conveyance, ◎, when conveyance was not possible within 5 times, ○, 5 times In the case where the sheet could not be conveyed even once, the judgment was made in three stages of x.

(Releasability evaluation test)
In the peelability evaluation test, the sample of each cushion material 1 of the example and the comparative example was sandwiched between stainless steel plates, pressed to 4 MPa using a vacuum press tester, and then heated to 230 ° C. for 1 hour. After heating and holding at 230 ° C. for 1 hour, cooling to 50 ° C. over 30 minutes, and reducing the pressure to 0 MPa as one cycle, when this step is repeated 100 cycles, does the cushion material 1 peel off? The releasability was evaluated based on whether or not. The releasability was evaluated on a three-point scale. If the cushion material 1 was not adhered to the hot press platen 20. If the cushion material 1 could be peeled off by hand even if it was adhered to a stainless steel plate, the cushion material 1 was evaluated. Was evaluated as × when the sample was adhered to the stainless steel plate and could not be peeled off manually.

(Flexibility evaluation test)
In the evaluation test of flexibility, the presence or absence of warpage of the press target is evaluated based on whether or not the press target is warped when each of the cushion materials 1 of the examples and the comparative examples is used. Flexibility was evaluated based on the degree of warpage of the object. The flexibility is evaluated in three stages. If the object to be pressed does not warp, the object to be pressed is warped. If the degree of warpage is small, the object to be pressed is warped. If the degree of is large, it was evaluated as x.

  Table 1 shows the evaluation results of the suction-conveying property, the peeling property, the flexibility, and the warpage of the press target for the cushion materials 1 of the examples and the comparative examples.

Based on the results in Table 1, the relationship between the air permeability of the cushion material 1 and the suction conveyance property was examined. As a result, Example 1 in which the minimum fiber diameter of the glass cloth was 300 μm or more, or the weave density of the glass cloth was 10 yarns / cm or more for both warp and weft, and the PTFE impregnation amount was 100 g / m ² or more. The cushion materials 1 of Comparative Examples 6 to 6 and Comparative Examples 3, 6, 7, and 9 had almost no air permeability of 1.0 cm ³ / cm ² · s or less and were excellent in airtightness, so that suction conveyance was possible. . However, the cushion material 1 of Comparative Examples 1 and ² in which the PTFE impregnation amount is less than 100 g / m ² and the cushion material 1 of Comparative Example 4 in which the weaving density of the glass cloth is less than 10 yarns / cm for both the warp and the weft. In addition, the cushion material 1 of Comparative Example 8 in which the minimum value of the fiber diameter of the glass cloth was less than 300 μm had high air permeability and low airtightness, and thus could not be conveyed by suction. This is because the weave density of the glass cloth used for the cushioning material 1 of Comparative Example 4 is as low as less than 10 yarns / cm for both the warp and the weft, and the fiber diameter of the glass cloth used for the cushioning material 1 of Comparative Example 8 is 300 μm. It is considered that a large gap is formed between the yarns because the porosity is as small as less than 80% and the porosity is more than 80%. The cushion materials 1 of Comparative Example 1 and Comparative Example 2 have a porosity of 80% or less, but have 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 considered that the adhesion was insufficient. Although the cushion material 1 of Comparative Example 5 had a PTFE impregnation amount of less than 100 g / m ² , it had high airtightness, no air permeability, and was able to be conveyed by suction. This is because even if the cushion material 1 of Comparative Example 5 had a small PTFE impregnation amount of less than 100 g / m ² and the impregnation inside the woven yarn and the adhesion of the surface of the woven fabric were insufficient, the cushion material 1 of Comparative Example 5 was insufficient. It is considered that the weave density of the glass cloth used for the cushion material 1 is as large as 50 yarns / cm or more for both the warp and the weft, and the space between the woven fabrics is dense.

  Further, based on the results in Table 1, the relationship between the surface roughness Ra of the surface layer 6 and the suction conveyance property was examined. As a result, the cushion materials 1 of Examples 1 to 6 and Comparative Examples 3, 5, 6, 7, and 9 having a surface roughness Ra of 60 μm or less could be suction-conveyed. In particular, Examples 5 and 6 and Comparative Examples 3, 5, 6, 7, and 9 having a surface roughness Ra of 50 μm or less were able to be suction-conveyed five times, and were evaluated as ◎. It is considered that when the surface roughness Ra is 60 μm or less, high airtightness is sufficiently ensured between the surface layer of the cushion material 1 and the automatic laminating apparatus. However, the cushion materials 1 of Comparative Examples 1, 2, 4, and 8 having a surface roughness Ra larger than 60 μm could not be conveyed by suction. This is because the cushion material 1 of Comparative Examples 1, 2, 4, and 8 had a surface roughness Ra of more than 60 μm and low airtightness, so that the surface layer of the cushion material 1 could not be sucked by the automatic laminating apparatus. it is conceivable that.

Further, based on the results in Table 1, the relationship between the surface roughness Ra of the surface layer 6 and the releasability was examined. As a result, the porosity of the glass cloth is 10% or more (that is, the maximum fiber diameter of the glass cloth is 600 μm or less, or the weave density of the glass cloth is 30 yarns / cm or less for both warp and weft), and PTFE is used. The cushion materials 1 of Examples 1 to 6 and Comparative Examples 1, 2, 4, and 8 having an impregnation amount of 200 g / m ² or less and a surface roughness Ra of 20 μm or more adhere to the stainless steel plate even when repeatedly used for 100 cycles. Did not. However, the cushion material 1 of Comparative Example 3 in which the PTFE impregnation amount was more than 200 g / m ^2, the cushion material 1 of Comparative Examples 5, 6, and 7 in which the weaving density of the glass cloth was more than 30 yarns / cm for both the warp and the weft, and the glass cloth The cushion material 1 of Comparative Example 9 having a maximum fiber diameter of more than 600 μm had a surface roughness Ra of less than 20 μm and adhered to the stainless steel plate without having 100 cycles. The cushion materials 1 of Comparative Examples 3, 6, 7, and 9 were completely adhered to the stainless steel plate and could not be peeled off. On the other hand, the cushion material 1 of Comparative Example 5 was adhered to the stainless steel plate, but could be peeled off by pulling with a force, and was evaluated as Δ. This is because the woven density of the glass cloth used for the cushion material 1 of Comparative Examples 5, 6, and 7 is more than 30 yarns / cm for both the warp and the weft, and the fiber of the glass cloth used for the cushion material 1 of Comparative Example 9 Since the diameter is larger than 600 μm and the porosity is as small as less than 10%, it is considered that the space between the yarns is too dense. The cushion material 1 of Comparative Example 3 had a porosity of 10% or more, but had a surface roughness Ra of less than 20 μm, and was adhered to the stainless steel plate. This is presumably because the PTFE impregnated amount of the glass cloth used for the cushion material 1 of Comparative Example 3 was more than 200 g / m ² , and the irregularities formed on the surface of the woven fabric 60 were crushed.

Further, based on the results in Table 1, the relationship between the hardness of the cushion material 1 and the flexibility of the cushion material 1 and the presence or absence of warpage of the pressed object were examined. As a result, the porosity of the glass cloth is 10% or more (that is, the maximum fiber diameter of the glass cloth is 600 μm or less, or the weave density of the glass cloth is 30 yarns / cm or less for both the warp and the weft, and the PTFE impregnation is performed). The hardness of the cushion material 1 of the examples 1 to 6 and the comparative examples 1, 2, 4, and 8 having an amount of 200 g / m ² or less is 90 degrees or less, and even if the cushion material 1 is used for pressing. No warping was observed in the pressed object, indicating high flexibility.However, the cushioning material 1 of Comparative Examples 5, 6, and 7 in which the weave density of the glass cloth was more than 30 fibers / cm, and the impregnation amount of PTFE was lower. cushion member 1 of 200 g / m ² more than in Comparative example 3 and 7, the maximum value of the hardness of the cushion member 1 of 600μm greater than comparative example 9 having a fiber diameter of the glass cloth is greater than 90 degrees, using the cushion material 1 When the pressing was performed, the object to be pressed was warped and the flexibility was low, and when the cushioning materials 1 of Comparative Examples 5 and 9 were used, the object to be pressed was warped. However, since the warpage was smaller than the case where the cushioning materials 1 of Comparative Examples 3, 6, and 7 were used, the flexibility was evaluated as 。. Since the weaving density of the glass cloth used is more than 30 yarns / cm for both the warp and the weft, and the fiber diameter used for the cushioning material 1 of Comparative Example 9 is larger than 600 μm and the porosity is less than 10%, It is considered that the space between the yarns of the glass cloth is too dense, and the cushion material 1 of Comparative Example 3 has a porosity of 10% or more, but has a PTFE impregnation amount of more than 200 g / m ² , Woven fabric 60 itself becomes PTFE Ri is considered that has become hard.

  In addition, when each sample of the cushioning material 1 of the example and the comparative example was used, it was confirmed whether or not there was any change in appearance, physical properties, etc. of the object to be pressed other than warping, but no difference was found.

[Consideration of evaluation test of suction conveyance property, peeling property and flexibility]
From the above-described evaluation tests of the suction conveyance property, the peeling property, and the flexibility, the following has become clear.

From the results of the evaluation test of the suction conveyance property, the minimum value of the fiber diameter of the glass cloth was 300 μm or more, or the weave density was 10 yarns / cm or more for both warp and weft, and the PTFE impregnation amount was 100 g / m ² or more. The air permeability of the cushion material 1 was 1.0 cm ³ / cm ² · s or less, and it was confirmed that the cushion material 1 was excellent in 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.

  From the results of the evaluation test of the suction conveyance property, it was confirmed that when the surface roughness Ra of the surface layer 6 was 60 μm or less, the suction conveyance property was excellent. Furthermore, it was confirmed that when the surface roughness Ra of the surface layer 6 was 50 μm or less, it was particularly excellent in suction conveyance properties.

In addition, from the results of the peelability evaluation test, the maximum fiber diameter of the glass cloth was 600 μm or less, or the weave density of the glass cloth was 30 yarns / cm or less for both the warp and the weft, and the PTFE impregnation amount was 200 g / cm 2. The surface roughness Ra of the surface layer 6 of the cushion material 1 of m ² or less was 20 μm or more, and it was confirmed that the cushion material 1 was excellent in releasability. Further, it was confirmed that when the porosity of the glass cloth was less than 10%, the releasability was not satisfied.

Furthermore, from the results of the evaluation test of flexibility, the maximum value of the fiber diameter of the glass cloth is 600 μm or less, or the weave density of the glass cloth is 30 yarns / cm or less for both the warp and the weft, and the PTFE impregnation amount is 200 g / cm 2. It was confirmed that the cushion material 1 having a m ² or less had a hardness of 90 degrees or less, the warp was not observed in the object to be pressed, and the flexibility was high. In addition, it was confirmed that when the porosity of the glass cloth was less than 10%, the press target was warped.

As described above, in order to be able to carry by suction, to have good releasability from a press board or the like, and not to cause warpage of the object to be pressed, the air permeability of the cushion material 1 must be 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 cushion material 1 may be formed so that the hardness of the cushion material 1 is 90 degrees or less. Therefore, the porosity of the glass cloth is 10 to 80% (that is, the fiber diameter of the glass cloth is 300 to 600 μm, and the weave density of the glass cloth is 10 to 30 yarns / cm for both the warp and the weft), and It became clear that the cushion material 1 should be formed so that the PTFE impregnation amount is 100 to 200 g / m ² .

[Evaluation Test of Suction Conveyability and Peelability when Surface Roughness Ra is Changed]
Furthermore, four types of cushion materials 1 of Examples 7 to 10 were produced by experimentally changing the surface roughness Ra of the surface layer 6 in Example 1 with reference to the cushion material 1 of Example 1. Then, the correlation between the surface roughness Ra of the surface layer 6 and the suction conveyance property was verified for the cushion materials 1 of Example 1 and Examples 7 to 10. For the cushioning material 1 of Examples 7 to 10, first, the same pressing time was applied to the same glass cloth as that used as the surface layer 6 of Example 1 by changing the pressing time of being pressed between the press plates. Four types of glass cloths having different roughnesses 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 of Example 1. Thereafter, cushion materials 1 of Examples 7 to 10 were produced in the same manner as in Example 1 using the four types of glass cloths as surface layers 6. The surface roughness of the surface layer 6 of the cushioning material 1 of each of Examples 7 to 10 was measured using a surface texture measuring device (SURF TEST500 manufactured by Mitutoyo Corporation, standard stylus model number 996133) after the cushioning material 1 was manufactured. The surface layer 6 was scanned in the warp direction at a speed of 2 mm / s to measure a range of 40 mm, 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, and the suction of the simple suction device is performed so that the vacuum gauge becomes 0.02 MPa. Adjusted the power. Subsequently, a simple suction test of each cushion material 1 of Example 1 and Examples 7 to 10 was performed, and the value of a vacuum gauge was recorded and used as an index of the suction force.

  Then, as an evaluation test of the suction conveyance property, each of the cushion materials 1 of Example 1 and Examples 7 to 10 is suctioned and conveyed by an automatic laminating device (a device for sucking and conveying the cushioning material with a suction pad and laminating). Then, the suction conveyance property was evaluated based on whether the cushion material 1 did not fall. Evaluation of the suction conveyance property was performed 5 times for each cushion material. When all 5 times were conveyed during suction conveyance, ◎, when conveyance was not possible within 5 times, ○, 5 times In the case where the sheet could not be conveyed even once, the judgment was made in three stages of x.

(Releasability evaluation test)
In the peelability evaluation test, the sample of each cushion material 1 of Example 1 and Examples 7 to 10 was sandwiched between stainless steel plates, and pressed to 4 MPa using a vacuum press tester, and then taken for 1 hour. When the temperature was raised to 230 ° C., the temperature was maintained at 230 ° C. for 1 hour, the temperature was reduced to 50 ° C. over 30 minutes, and the pressure was reduced to 0 MPa as one cycle. The peelability was evaluated based on whether or not the film was peeled. The releasability was evaluated on a three-point scale. If the cushion material 1 was not adhered to the hot press platen 20. If the cushion material 1 could be peeled off by hand even if it was adhered to a stainless steel plate, the cushion material 1 was evaluated. Was evaluated as × when the sample was adhered to the stainless steel plate and could not be peeled off manually.

  Table 2 shows the results of the simple suction test, the suction conveyance property, and the evaluation of the releasability of the cushioning materials 1 of Example 1 and Examples 7 to 10.

  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, Examples 9 and 10 in which the surface roughness Ra was 50 μm or less had better suction-conveying properties than Examples 1, 7, and 8 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 and the releasability when the surface roughness Ra of the surface layer 6 was changed was examined. As a result, Examples 7 to 10 in which the surface roughness Ra was 20 μm or more had excellent releasability as in Example 1.

[Consideration on evaluation test of suction transferability and peelability when surface roughness Ra is changed]
From the evaluation test of the suction conveyance property and the peeling property when the surface roughness Ra of the surface layer 6 was changed, the following became clear.

  From the results of the releasability evaluation test, it was confirmed that when the surface roughness Ra of the surface layer 6 was 20 μm or more, there was no problem with the releasability, similarly to the results of the releasability evaluation test shown in Table 1 above. .

  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 more preferably 20 to 60 μm, and in particular, the surface roughness Ra of the surface layer 6 is more preferably 20 to 50 μm in order to achieve both the releasability and the suction conveyance property. Range.

  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 suctioned and conveyed, has good releasability from a press board or the like, and does not cause warpage of an object to be pressed.

DESCRIPTION OF SYMBOLS 1 Hot press cushion material 2 Laminated body 4 Rubber layer 5 Intermediate layer 6 Surface layer 60 Textile material 61 Warp 62 Weft

Claims (5)

A hot-press cushion material used by being interposed between a hot-pressing machine and a pressing object,
A laminate in which at least two rubber layers and an intermediate layer made of a multi-woven cloth interposed between the rubber layers,
Laminated on the surface of the laminate, a heat-resistant fiber member as a base material, comprising a surface layer of a woven or knitted fabric having irregularities formed by the heat-resistant fiber member on the surface,
A heat-resistant resin is impregnated into the interior of the heat-resistant fiber member, and does not cover the irregularities, but is attached to the surface of the woven fabric or knit thin enough to retain the irregularities,
The amount of the heat-resistant resin impregnated into the heat-resistant fiber member is 100 to 200 g / m ² , and the woven density of the woven fabric or knitted fabric is 10 to 30 yarns / cm for both the warp and the weft. A hot-press cushion material, wherein the hardness of the entire hot-press cushion material is 90 degrees or less.   The cushioning material for hot press according to claim 1, wherein the surface roughness of the surface layer is an arithmetic average roughness Ra of 20 µm or more and Ra of 50 µm or less. The hot-press cushion material according to claim 1 or ² , wherein the entire air-permeability of the hot-press cushion material is 1.0 cm ³ / cm ² · s or less.   The cushioning material for hot press according to any one of claims 1 to 3, wherein the heat resistant fiber member is a glass fiber.   The cushioning material for hot press according to any one of claims 1 to 4, wherein the heat resistant resin is a fluororesin.

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