JP2018075631A - Cushion material for hot press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cushion material for hot press which secures bending durability and can prevent delamination between a laminate and a surface layer while keeping cushion properties.SOLUTION: A cushion material 1 for hot press includes a laminate 2, a surface layer 6 and a sewing portion 10. The laminate 2 has an intermediate layer 5 which is interposed between three rubber layers 4 and a rubber layer 4 and is made of multiplex woven cloth laminated thereon. The cushion material 1 for hot press has the surface layer 6 laminated on both sides of the rubber layer 4 on the outermost side of the laminate 2. The surface layer 6 is made of woven fabrics and knitted fabrics made of a heat resistant fiber member. The surface layer 6 has a heat resistant resin. The sewing portion 10 is sewn along at least a part of the whole circumference of a peripheral edge portion 12 on the surface on both sides of the surface layer 6 laminated on the surface on both sides of the laminate 2 so as to pass through the laminate 2 and the surface layer 6 in a thickness direction where the laminate 2 and the surface layer 6 are laminated.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a hot press cushioning material used by being interposed between a hot press disk and a press object.

  In general, in the manufacturing process of a laminated board having a laminated structure, such as a copper clad laminated board, a flexible printed board, a printed board such as a laminated board, an IC card, a ceramic laminated board, a liquid crystal display board, etc. For this purpose, a hot press is performed. When performing hot pressing, in order to apply heat and pressure uniformly to the object to be pressed, a mirror plate made of a flat plate-like hot press cushioning material and a stainless steel plate is placed between the hot press machine and the object to be pressed. Be placed. Such a heat press cushion material is required to have cushioning properties, thermal conductivity, heat resistance and durability. Such a hot press cushioning material includes a rubber layer made of fluorine rubber, an intermediate layer made of a multi-woven cloth of heat-resistant fibers such as glass fibers and aromatic polyamide fibers, glass fibers and aromatic polyamide fibers, etc. In general, the surface layer of the fiber member is laminated. When manufacturing such a hot-press cushion material, usually, a rubber sheet as a rubber layer and a multi-woven cloth as an intermediate layer or a fiber member as a surface layer are laminated together and integrated by vulcanization. . Then, it cut | disconnects to the size suitable for a predetermined | prescribed hot press board.

  And the member used for the surface layer of the cushioning material for hot press has characteristics such as airtightness when sucked and conveyed by an automatic laminating apparatus, releasability from a hot press panel or mirror plate after hot pressing, etc. In addition to being demanded, a high cushioning property as a cushion material for hot press is demanded. Here, releasability means ease of removal from a mold such as a hot press panel or a mirror plate. Specifically, releasability represents a property that does not cause adhesion or seizure on the surface, and is also referred to as non-adhesiveness. As a cushioning material for such a hot press, for example, in Patent Document 1, a rubber layer of fluororubber with good heat resistance is formed on both surfaces of a glass fiber cloth as an intermediate layer, and an aramid fiber or the like is formed on the upper part. A cushion material for hot pressing in which a surface layer made of wholly aromatic fibers with good heat resistance is laminated is described. However, since the cushioning material for hot press described in Patent Document 1 has insufficient airtightness in the surface layer, there is a problem such as dropping when sucked and conveyed by an automatic laminating apparatus or the like, and further improvement is required. It was done.

  Therefore, Patent Document 2 discloses a cushion material for hot press that can be sucked and conveyed and has good releasability from a hot press board or the like. The cushion material for hot press described in Patent Document 2 has a heat-resistant fiber member as a base material, a surface layer made of woven or knitted fabric that forms irregularities on the surface, an intermediate layer made of multi-woven cloth, a surface layer and an intermediate A laminate in which a rubber layer composed of an unvulcanized rubber sheet interposed between layers or between intermediate layers is laminated by pressing and vulcanizing immediately before the crosslinking reaction starts. Yes. The heat-resistant resin is impregnated inside the yarn of the woven fabric or knitted fabric, and is attached to the surface of the woven fabric or knitted fabric so as not to cover the unevenness. With such a configuration, the cushioning material for hot press described in Patent Document 2 ensures suction conveyance properties and releasability from a hot press board and the like. Here, the adhesion between the intermediate layer and the surface layer is based on the thermocompression processing of the rubber layer interposed between the two layers, and the rubber layer is formed on the surface of the intermediate layer and the fine irregularities on the surface layer surface. Enters, cures and adheres. That is, the adhesion between the intermediate layer and the surface layer is an adhesion form in which the so-called anchor effect is dominant. However, when the hot press cushion material is sucked and conveyed by an automatic laminating apparatus or the like, when the hot press cushion material is conveyed in a lifted state by suction, the vicinity of the end portion of the hot press cushion material is easily bent. . Therefore, when the bending is repeated by continuous use such as suction conveyance, bending deformation in the vicinity of the end portion repeatedly occurs. The rubber layer cannot follow the deformation of the surface layer and the intermediate layer accompanying the bending deformation, the rubber layer is pulled out from the unevenness of the yarn, and the part where the rubber layer is pulled out expands to cause delamination. That is, if bending durability is not ensured, delamination occurs between the surface layer and the rubber layer of the laminate. In the surface layer, the heat-resistant resin penetrates into the inside of the yarn and the heat-resistant resin adheres to the surface of the yarn, so that the amount of the rubber layer entering is small, and the interlayer is between the surface layer and the laminate. Peeling easily occurs. In particular, when a heat-treated surface layer is used, peeling becomes easier. Therefore, as a countermeasure against delamination between the surface layer and the laminate, the rubber applied to the surface layer can be increased by increasing the pressing force during the preparation of the hot press cushioning material or by increasing the pressurization start time. The amount of entering the layer can be increased. However, this countermeasure has a problem in that the amount of the rubber layer entering the intermediate layer increases and the cushion amount decreases.

JP-A-6-305091 Japanese Patent Laying-Open No. 2015-127065

  The present invention solves the above-mentioned problems, and in addition to securing suction transportability and releasability with a hot press board, etc., while maintaining cushioning properties, it ensures bending durability and is laminated. It aims at providing the cushioning material for hot presses which can prevent delamination of a body and a surface layer.

  In order to solve the above-described problems, a hot press cushioning material according to the present invention is a hot press cushioning material used by being interposed between a hot press disk and a press object, and includes at least two rubber layers, And formed of a bulky multi-woven cloth interposed between the rubber layers, formed on the surface of the multi-woven cloth and formed into the irregularities into which the rubber of the rubber layer has penetrated, and formed inside the multi-woven cloth. A laminated body in which an intermediate layer having a gap is laminated, and a woven or knitted fabric having yarns made of heat-resistant fiber members, laminated on both surfaces of the outermost rubber layer of the laminated body. The surface layer having a heat-resistant resin, and the laminated body and the surface layer are laminated on the surfaces on both sides of the laminated body so as to penetrate the laminated body and the surface layer in a thickness direction in which the laminated body and the surface layer are laminated. The circumference of the surface on both sides of the surface layer Along at least a portion of the entire periphery of the part, the cushioning pad for hot pressing, characterized in that it comprises a stitching portion that is sewn in the sewing thread made of heat-resistant fiber material.

According to the cushion material for hot presses of the present invention, the laminate, the surface layer, and the sewing portion are provided. In the laminated body, at least two rubber layers and an intermediate layer made of a bulky multi-woven cloth interposed between the rubber layers are laminated. An intermediate | middle layer has the unevenness | corrugation in which the rubber | gum of the rubber layer infiltrated was formed in the surface of a multi-woven cloth, and the space | gap formed in the inside of a multi-woven cloth. The surface layer is laminated on both sides of the outermost rubber layer of the laminate. The surface layer is made of a woven fabric or a knitted fabric having yarns made of a heat resistant fiber member. The surface layer has a heat resistant resin. In addition, the sewing portion is formed so that all of the peripheral portions on the surfaces on both sides of the surface layer laminated on the surfaces on both sides of the laminate so as to penetrate the laminate and the surface layer in the thickness direction in which the laminate and the surface layer are laminated. It is sewn along at least part of the circumference. Thereby, each layer of a laminated body and a surface layer is stitched up firmly. And even if a part outside the peripheral part of the surface layer is peeled off from the laminate, the sewn part stitches the surface layer to the laminate at the peripheral part, so that the laminate and the surface layer are delaminated at the peripheral part. Does not occur. Therefore, expansion of delamination between the surface layer and the laminate can be prevented by the sewing portion. Further, when deformation due to bending occurs in the cushion material for hot press, each layer of the laminate and the surface layer is firmly stitched together, so that each layer follows the movement. Thereby, the rubber of the rubber layer does not come off from the irregularities of the intermediate layer and the surface layer, and the anchor effect of the rubber layer is maintained. Therefore, the bending durability of the hot press cushion material can be ensured. And delamination of a laminated body and a surface layer can be prevented. Furthermore, the sewing part is sewn with a sewing thread made of a heat-resistant fiber material. That is, since the sewing thread used for sewing has heat resistance, it does not deteriorate even in a use environment at a high temperature (for example, 200 ° C. or higher) for performing hot pressing. Therefore, the bending durability of the hot press cushioning material can be ensured over a long period of time, and delamination of the laminate and the surface layer can be prevented. Further, since the sewing thread used for sewing is a fiber material and is soft, it does not affect the pressure distribution in the sewing portion. Therefore, the cushioning properties of the hot press cushioning material can be maintained. From the above, it is possible to provide a cushioning material for hot pressing that maintains the cushioning properties while ensuring bending durability and prevents delamination between the laminate and the surface layer.
In addition, the surface of a surface layer is a surface of the direction orthogonal to the thickness direction of the surface layer laminated | stacked on a laminated body. The side surface of the surface layer is a surface in the thickness direction of the surface layer laminated on the laminate.

  In the above-mentioned cushioning material for hot press, it is preferable that the peripheral portion is a portion from 3 mm to 5 mm inward from the end of the surface of the surface layer.

In this configuration, the peripheral edge is a portion from 3 mm to 5 mm inward from the edge of the surface of the surface layer. Specifically, the peripheral edge is an elongated range delimited by a portion from 3 mm or more (W1) to 5 mm or less (W2) inward from the edge of the surface of the surface layer. The width W of the peripheral edge is a predetermined length (up to about 2 mm). A sewing portion that is sewn with a sewing thread is provided along the peripheral edge portion. Eventually, the sewing thread of the sewing part is provided at a sewing position (center position of the sewing thread) of 3 to 5 mm inward from the end of the surface of the surface layer.
Thereby, a laminated body and a surface layer can be sewn more reliably. And even if a part outside the peripheral part of the surface layer peels, the delamination of the laminate and the surface layer does not occur at the peripheral part because the sewing part stitches the surface layer to the laminated body at the peripheral part. . Therefore, expansion of delamination between the surface layer and the laminate can be further prevented by the sewing portion.

  In the heat press cushion material, it is preferable that the sewing portion is sewn along the entire periphery of the peripheral portion.

  In this configuration, the sewing portion is sewn along the entire circumference of the peripheral edge portion. Thereby, even if a part outside the peripheral part of the surface layer is peeled off, the sewing part in the peripheral part stitches the surface layer to the laminate along the entire periphery of the peripheral part. No delamination of the surface layer occurs. Therefore, expansion of delamination between the surface layer and the laminate can be further prevented by the sewing portion. Further, when deformation due to bending occurs in the cushioning material for hot press, each layer of the laminate and the surface layer is sewn more firmly, so that each layer follows the movement. Thereby, the rubber of the rubber layer does not come off from the irregularities of the intermediate layer and the surface layer, the anchor effect of the rubber layer is further maintained, and delamination of the laminate and the surface layer can be further prevented.

  In the heat press cushion material, the sewing thread is preferably para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber.

  In this configuration, the sewing thread is para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber. That is, the sewing thread is a heat-resistant fiber having high strength and high elasticity. As a result, the sewing thread has high strength, and the layers of the laminate and the surface layer can be firmly sewn without cutting the sewing thread. You can follow each movement. Therefore, the bending durability of the hot press cushion material can be ensured. And delamination of a laminated body and a surface layer can be prevented. Further, since the sewing thread is highly elastic and soft, it does not affect the pressure distribution at the sewing portion. Therefore, the cushioning properties of the hot press cushioning material can be maintained. Furthermore, since the sewing thread has heat resistance, it does not deteriorate even in a high temperature use environment where hot pressing is performed, and generation of fluff is extremely small.

  In the heat press cushioning material, the sewing thread has a tensile strength of 2530 cN or more, and a length of a seam that is a part of the sewing thread formed on the surface layer of the sewing portion is 1. It is preferable that it is 5-3.0 mm.

  In this configuration, the sewing thread has a tensile strength of 2530 cN or more. The length of the seam of the sewing thread is 1.5 to 3.0 mm. Here, the seam is a part of the sewing thread formed on the surface of the surface layer of the sewing portion. The length of the seam here does not mean the total length of a part of the sewing thread formed on the surface of the surface layer of the sewing portion, but is formed on the surface of the surface layer of the sewing portion. It means the length of each part of the sewing thread. Thereby, the sewing thread has moderately high strength and high elasticity. Moreover, each layer of a laminated body and a surface layer is sewn together firmly by the seam of moderate length. And when deformation | transformation by bending arises in the cushion material for hot presses, delamination can be reliably prevented at the bending location.

  In the cushion material for a hot press, the sewing thread preferably has a total fineness of 555 to 1332 dtex.

  In this configuration, the sewing thread has a total fineness of 555 to 1332 dtex. Thereby, since the sewing thread has an appropriate elasticity, the pressure does not concentrate on the sewing thread during hot pressing, and the pressure distribution of the sewing portion is not affected.

  In the heat press cushion material, the heat-resistant resin is impregnated inside the yarn, and the surface of the woven or knitted fabric is thin enough not to cover the unevenness formed on the surface by intersecting the yarn. It is preferable that it adheres to.

  In this configuration, the heat-resistant resin is impregnated into the inside of the yarn, and adheres to the surface of the woven or knitted fabric so as not to cover the unevenness formed on the surface by intersecting the yarn. As a result, the entire surface layer is not covered with a heat-resistant resin, and there are many gaps in the surface layer, so the surface layer has a large surface roughness and good releasability from a hot press machine, etc. Can be. In addition, since the unevenness | corrugation of a surface layer is hard to lose | disappear even after using the cushion material for hot presses repeatedly, mold release property with a hot press board etc. can be maintained favorable. In addition, the surface layer has a large surface roughness and there are many gaps in the surface layer. However, due to the anchor effect of the heat-resistant resin impregnated in the surface layer and the rubber layer laminated inside the surface layer, The rubber is infiltrated into the gap between the surface layers, the gap between the surface layers is closed and the ventilation is blocked, the airtightness can be increased, and suction conveyance is possible. Furthermore, since the amount of the heat-resistant resin is small, the hardness of the cushioning material for hot pressing is reduced, and the flexibility of the cushioning material for hot pressing is provided, so that the press object can be prevented from warping.

  As described in the above description, according to the present invention, there is provided a hot press cushioning material capable of securing bending durability and preventing delamination between the laminate and the surface layer while maintaining cushioning properties. Can be provided.

It is a conceptual diagram explaining the hot press using the cushion material for hot presses concerning this embodiment. It is sectional drawing which shows typically the cushion material for hot presses concerning this embodiment. It is sectional drawing which shows typically the surface layer of the cushion material for hot presses concerning this embodiment, (a) shows the state before a press, and (b) shows the state after using it for repeated press. It is a figure which shows typically the cushion material for hot presses concerning this embodiment, (a) is a top view, (b) is XX sectional drawing of (a).

Embodiments of the present invention will be described with reference to the drawings.
The cushioning material for hot pressing according to the present embodiment is a process for producing a laminated board having a laminated structure such as a copper-clad laminated board, a flexible printed board, a printed board such as a laminated board, an IC card, a ceramic laminated board, a liquid crystal display board, etc. Used in hot pressing for press molding or thermocompression bonding.

[Hot press]
First, based on FIG. 1, the hot press using the hot-press cushion material which concerns on this embodiment is demonstrated.

  As shown in FIG. 1, an example is shown in which a press object 21 is press-molded by a hot press disk 20 using the hot press cushioning material 1 according to the present embodiment.

  As shown in FIG. 1, two flat heat press cushion materials 1 are disposed between two heat press plates 20, and stainless steel is further interposed between the two heat press cushion materials 1. A press object 21 is arranged through the plate 22. That is, the hot press cushioning material 1 and the stainless steel plate 22 are interposed between the two hot press machines 20 and the press object 21, respectively. In this state, heat and pressure are applied by the hot press machine 20. The pressing conditions are, for example, a temperature of room temperature to 260 ° C., a pressing force of 0.5 to 100 MPa, and a pressing time of 1 to 3 hours. The cushioning material 1 for hot pressing is used for the purpose of uniformly applying pressure and heat to the object 21 to be pressed.

[Cushion material for heat press]
Next, based on FIG.2 and FIG.3, the hot press cushion material 1 which concerns on this embodiment is demonstrated.

  As shown in FIG. 2, the hot press cushioning material 1 is formed by laminating a rubber layer 4, an intermediate layer 5, and a surface layer 6. The hot-press cushion material 1 according to the present embodiment includes a laminate 2 and a surface layer 6. In the laminate 2, three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4 are laminated. Rubber layers 4 are disposed 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 cushion material 1 for hot press 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 of the paper surface shown in FIG. It has been done. The intermediate layer 5 and the rubber layer 4 are not limited to two layers and three layers, respectively. For example, the intermediate body 5 may be a single layer, and the laminate 2 may be configured by being interposed between two rubber layers 4. Alternatively, the intermediate body 5 may be composed of three layers, and the laminate 2 may be configured by interposing between the four rubber layers 4.

The rubber layer 4 is composed of a rubber composition. As the rubber component, fluorine rubber or silicon rubber excellent in heat resistance and low compression set can be used. If the compression set is small, the durability is improved. 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 value of 25 to 75 for the rubber layer 4 and controlling the fluidity of the rubber, the rubber of the rubber layer 4 penetrates into the gap of the surface layer 6 due to the anchor effect. It becomes easy to do, and airtightness can be cut off to ensure airtightness. Examples 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, 2 as a crosslinking agent 5-dimethyl-2,5-di (t-butylperoxy) -hexane-3, 1,3-bis (t-butylperoxy-isopropyl) benzene, 1,1-di-butylperoxy-3, Organic peroxide crosslinking agents such as 3,5-trimethylcyclohexane, polyol 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 fluororubbers such as amine crosslinking agents such as EPA) and hexamethylenediamine (HMDA) can be used.

  Moreover, when using a silicone rubber composition for the rubber layer 4, a well-known organic peroxide type crosslinking agent can be used as a crosslinking agent.

  Further, the rubber composition constituting the rubber layer 4 contains those used in ordinary rubber compounds such as fillers, plasticizers, stabilizers, processing aids, and colorants, as necessary. The Further, 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 cushion material for hot press 1 when not vulcanized, the average thickness per layer of the rubber layer 4, that is, the average thickness of one rubber sheet that becomes the rubber layer 4 before pressure lamination. Is preferably 4 to 10% of the thickness of the cushion material 1 for hot press. This is because 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 lowered. Further, if it exceeds 10%, the material cost increases, and the heat transfer property may be reduced by the increase in the total thickness of the hot press cushioning material 1.

  The mid layer 5 is composed of a multi-woven cloth. As the multi-woven cloth, there are a double woven cloth, a triple woven cloth, a quadruple woven cloth, and the like, and those woven with crimped yarns or those processed to be bulky in a cloth 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, the double woven cloth has a double woven structure in which two sets of upper and lower wefts are entangled with one set of warps.

  As the constituent yarn of the multi-woven cloth constituting the intermediate layer 5, glass fiber, carbon fiber, ceramic fiber, aramid fiber, PBO (polybenzobisoxazole) fiber, or the like is used. Preferably, inorganic fibers such as glass fiber, carbon fiber, and ceramic fiber are used. These have excellent heat resistance, high strength, and high elasticity. Therefore, it becomes possible to reinforce the rubber layer 4 made of the rubber composition.

  When glass fiber is used as the constituent yarn 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. As silane coupling agents, 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 composed of a fluororubber composition.

  As shown in FIGS. 3A and 3B, the surface layer 6 is composed of a woven fabric 60 woven with woven yarns (warp yarn 61 and weft yarn 62) made of a heat-resistant fiber member. That is, the fabric 60 has warps 61 and wefts 62. As shown in FIGS. 3A and 3B, the woven fabric 60 is woven so as to have a predetermined porosity to such an extent that irregularities exist on the surface of the surface layer 6. The porosity means the proportion of the space in the substance calculated from the difference between the actual volume and the apparent volume. Here, if the predetermined porosity of the fabric 60 is too small, the space between the woven yarns (warp yarn 61 and weft yarn 62) becomes too dense. When the space between the woven yarns becomes too dense, the surface roughness of the surface layer 6 is small, and the hardness of the cushioning material 1 for hot press is increased, which is preferable from the viewpoint of releasability and flexibility of the cushioning material 1 for hot press. Absent. On the other hand, if the predetermined porosity of the fabric 60 is too large, a large gap is formed between the woven yarns. If a large gap is formed between the woven yarns, the air permeability of the cushioning material 1 for hot press is increased, which is not preferable from the viewpoint of suction conveyance. Therefore, the predetermined porosity is such that irregularities are present on the surface of the surface layer 6, and is smaller than the porosity that creates a gap between the weaving yarns, and is too dense between the weaving yarns. Less weave density. Specifically, the predetermined porosity is, for example, 10 to 80%.

  Since the porosity of the fabric 60 changes depending on the diameter and weaving density of the woven yarn, the warp yarn 61 and the weft yarn 62 having a predetermined diameter have a predetermined weave so that the fabric 60 has a predetermined porosity. Woven with 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 woven yarn is too large, the space between the woven yarns becomes too dense and the porosity becomes small, and if it is too small, a gap is formed between the woven yarns and the porosity becomes large. On the other hand, if the weaving density is too large, the space between the yarns becomes too dense and the porosity becomes small, and if it is too small, a gap is formed between the weaving yarns and the porosity becomes large. Specifically, the diameter of the predetermined woven yarn is 300 to 600 μm. The predetermined weave density is, for example, 25 to 100 / 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 member that becomes the base material of the woven yarn (warp yarn 61 and weft yarn 62). Since the surface layer 6 of the heat press cushioning material 1 is composed of a woven fabric 60 woven with a woven yarn made of a heat-resistant fiber member, the surface of the heat press cushioning material 1 is not easily damaged, so that it is pressed uniformly. can do. In particular, a glass fiber having excellent heat resistance, high strength, and high elasticity is preferable as the heat resistant fiber member. When glass fiber is used for the heat-resistant fiber member, since the hot press cushion material 1 to be molded 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 drop from the suction conveyance device without sagging under its own weight. In addition, the adhesive strength between glass fiber and heat-resistant resin is not as weak as when other heat-resistant fibers such as aramid fiber are used, and the adhesive strength is strong even at high temperatures, so it can be used up to 260 ° C. In the invention, it is assumed that it is used in the range of 180 to 240 ° C.). Further, even in a high-temperature hot press, there is an advantage that fibers are not deteriorated and fluff is not generated.

  The fabric 60 is impregnated with a heat resistant resin 63. Examples of the heat resistant resin 63 include simple substances such as epoxy resin, phenol resin, melamine resin, fluorine resin, unsaturated polyester resin, silicone resin, polyimide resin, thermosetting acrylic resin, furan resin, urea resin, diallyl phthalate resin, and the like. , Blend systems or copolymers. Among these, a fluororesin having good heat resistance, low compression set, etc. is most preferable. The fabric 60 is made of a fabric such as plain weave, twill weave, and satin weave.

The heat resistant resin 63 is impregnated into the fabric 60 with a predetermined impregnation amount. As shown in FIG. 3A before pressing and FIG. 3B after repeated pressing, the predetermined amount of impregnation is inside the woven yarn (warp yarn 61, weft yarn 62) constituting the woven fabric 60. It is an amount that is impregnated and adheres thinly to the extent that the warp 61 and the weft 62 cross each other and do not cover the unevenness formed on the surface (the extent that the unevenness is retained). Note that the warp yarn 61 and the weft yarn 62 cross each other and adhere to an extent that does not cover the irregularities formed on the surface. The heat resistant resin 63 is attached to the warp yarn 61 and the weft yarn 62 at the portion where the warp yarn 61 and the weft yarn 62 intersect. It adheres to the surface of the warp 61 and the weft 62 along the shape. Here, if the impregnation amount of the heat resistant resin 63 is too small, the impregnation into the inside of the woven yarn and the adhesion of the surface of the woven fabric become insufficient, the airtightness of the surface layer 6 is insufficient, and the heat press cushioning material 1 The air permeability of the surface layer 6 is reduced, the surface roughness of the surface layer 6 is small, and the surface roughness of the surface layer 6 is small. The hardness of the cushioning material 1 for use is increased, which is not preferable from the viewpoint of mold release and flexibility of the cushioning material 1 for hot pressing. Therefore, the predetermined amount of impregnation is impregnated inside the woven yarn (warp yarn 61, weft yarn 62) constituting the woven fabric 60, and the warp yarn 61 and the weft yarn 62 intersect with each other to cover the unevenness formed on the surface. The amount is adjusted so as to be thin enough to hold. Specifically, the predetermined impregnation amount is, for example, 100 to 200 g / m ² . Further, 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, or cast coating.

As shown in FIG. 4, the hot press cushioning material 1 has a sewing portion 10. As shown in FIG. 4 (a), the sewing portion 10 is sewn with the sewing thread 11 along the entire circumference of the peripheral edge portion 12 on the surface on both sides of the surface layer 6 laminated on the surface on both sides of the laminate 2. Composed. The peripheral edge portion 12 is a portion inside the surface edge of the surface layer 6.
The peripheral edge portion 12 is a portion from the inner side of the surface layer 6 by a predetermined length W1 (3 mm or more) to the predetermined length W2 (5 mm or less) from the surface edge of the surface layer 6. It is preferably an elongated range that is delimited.
The predetermined length W of the peripheral edge portion 12 may be a value having a width or a single value. In the example of FIG. 4A, the peripheral edge 12 is a portion 3 to 5 mm inside from the end of the surface of the surface layer 6. In other words, the sewing thread 11 is provided at a sewing position (center position of the sewing thread) within a range of 3 to 5 mm inward from the end of the surface of the surface layer 6. Further, as shown in FIG. 4B, the sewing part 10 is sewn with a sewing thread 11 so as to penetrate the laminate 2 and the surface layer 6 in the thickness direction in which the laminate 2 and the surface layer 6 are laminated. Composed.

  The sewing thread 11 is made of a heat resistant fiber member. The sewing thread 11 is para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber. Further, the sewing thread 11 may be used after being impregnated and fired with a heat-resistant resin such as a fluororesin impregnated in the surface layer 6. The fibers constituting the sewing thread 11 are preferably 200 to 555 dtex. The sewing thread 11 may be used not only by one but also by bundling a plurality. The total fineness of the sewing thread 11 is preferably 555 to 1332 dtex. The tensile strength of the sewing thread 11 is preferably 2530 cN or more. Further, the stitches of the sewing thread 11 are preferably main sewing, double chain stitching, and overlock sewing. In the example of FIG. 4, the stitches of the sewing thread 11 are main stitches. The length L of the seam 11a of the sewing thread 11 is preferably about 1.5 to 3.0 mm. Here, the seam 11 a is a part of the sewing thread 11 formed on the surface of the surface layer 6 of the sewing portion 10. Here, the length of the seam 11a does not mean the total length of a part of the sewing thread 11 formed on the surface of the surface layer 6 of the sewing portion 10, but the length of the surface layer 6 of the sewing portion 10. This means the length of each part of a part of the sewing thread 11 formed on the surface.

[Method of manufacturing cushion material for hot press]
Next, the manufacturing method which manufactures the cushion material for hot presses concerning this embodiment is demonstrated.

  First, a laminate 2 is formed by alternately laminating three unvulcanized rubber sheets to be the rubber layer 4 and two multi-woven cloths to be the intermediate layer 5 so that the rubber sheet is on the outside. . Next, the fabric 60 impregnated with two heat resistant resins to be the surface layer 6 is laminated from both sides of the outer surface of the laminate 2 (that is, both sides of the outermost rubber sheet). The fabric 60 impregnated with two heat resistant resins to be the surface layer 6 is impregnated with a heat resistant resin and then preheated at a temperature of 360 to 430 ° C. And after heating (temperature 150-180 degreeC), after leaving for 0.2-15 minutes in a no-pressure state, immediately after the crosslinking reaction of the rubber layer 4 begins to act, surface pressure is maintained in the state which maintained temperature. Pressurize to 0.1-5.0 MPa, press vulcanize under the condition of press time 10 to 40 minutes, and integrate. And it cut | disconnects to the size suitable for a predetermined | prescribed hot press board. A shape having a size suitable for a predetermined hot press machine is, for example, a rectangle. Finally, the sewing part 10 is sewn with the sewing thread 11 of heat-resistant fibers along the entire circumference of the peripheral edge 12 on the surface on both sides of the surface layer 6 laminated on the surface on both sides of the laminate 2 with a sewing machine. Configure. As described above, the hot press cushioning material 1 according to the present embodiment is produced.

  In the hot-press cushion material 1 after vulcanization, the surface hardness of the hot-press cushion material 1 is preferably 81 to 87 degrees. The rubber layer 4 preferably has a hardness of 90 to 97 degrees. Moreover, it is preferable that the hardness of the surface layer 6 is 88-93 degree | times. Here, the hardness is a value measured by a type A hardness meter conforming to JIS K6253 (2012). As described above, the hardness of the surface layer 6 is made smaller than the hardness of the rubber layer 4, and the hardness of the surface of the cushioning material 1 for hot press is further reduced, so that the cushioning material 1 for hot pressing has an appropriate cushioning property. Can have.

  Further, in order to improve the compression set, after-curing may be performed at 200 to 250 ° C. for 30 minutes to 4 hours on the cushioning material 1 for hot press before being cut into a predetermined size.

  As described above, according to the hot press cushioning material 1 according to the present embodiment, the laminate 2, the surface layer 6, and the sewing portion 10 are provided. In the laminated body 2, at least two rubber layers 4 and an intermediate layer 5 made of a bulky multi-woven cloth interposed between the rubber layers 4 are laminated. The intermediate layer 5 has irregularities that are formed on the surface of the multi-woven cloth and into which the rubber of the rubber layer 4 has entered, and voids that are formed inside the multi-woven cloth. The surface layer 6 is laminated on both sides of the outermost rubber layer 4 of the laminate 2. The surface layer 6 is made of a woven fabric having yarns made of a heat resistant fiber member. Moreover, the surface layer 6 has a heat resistant resin. Further, the sewing part 10 has both sides of the surface layer 6 laminated on the surfaces on both sides of the laminate 2 so as to penetrate the laminate 2 and the surface layer 6 in the thickness direction in which the laminate 2 and the surface layer 6 are laminated. Is sewn along at least a part of the entire circumference of the peripheral edge portion 12 of the surface. Thereby, each layer of the laminated body 2 and the surface layer 6 is stitched firmly. And even if a part outside the peripheral edge portion 12 of the surface layer 6 is peeled off, the sewing portion 10 stitches the surface layer 6 to the laminated body 2 at the peripheral edge portion 12. And delamination of the surface layer 6 does not occur. Therefore, expansion of delamination between the surface layer 6 and the laminate 2 can be prevented by the sewing portion 10. Further, when deformation due to bending occurs in the cushioning material 1 for hot press, the layers 2 and the surface layer 6 are firmly sewn together, so that each layer follows the movement. Thereby, the rubber of the rubber layer 4 does not come out of the irregularities of the intermediate layer 5 and the surface layer 6, and the anchor effect of the rubber layer 4 is maintained. Therefore, the bending durability of the heat press cushioning material 1 can be ensured. And delamination of the laminated body 2 and the surface layer 6 can be prevented. Furthermore, the sewing part 10 is sewn with a sewing thread 11 made of a heat-resistant fiber material. That is, since the sewing thread 11 used for sewing has heat resistance, it does not deteriorate even in a use environment at a high temperature (for example, 200 ° C. or higher) at which hot pressing is performed. Therefore, the bending durability of the hot press cushioning material 1 can be ensured over a long period of time, and delamination of the laminate 2 and the surface layer 6 can be prevented. Further, since the sewing thread 11 used for sewing is a fiber material and is soft, it does not affect the pressure distribution of the sewing portion 10. Therefore, the cushioning properties of the hot press cushioning material 1 can be maintained. From the above, it is possible to provide the cushioning material 1 for hot press that maintains the cushioning property and ensures the bending durability and prevents the laminate 2 and the surface layer 6 from being delaminated.

  Further, the peripheral edge portion 12 is a portion inside the edge of the surface of the surface layer 6. Thereby, the laminated body 2 and the surface layer 6 can be sewn more reliably. And even if a part of the outer side of the peripheral portion of the surface layer 6 is peeled off, the sewing portion 10 stitches the surface layer 6 to the laminate 2 at the peripheral portion 12, so that at the peripheral portion 12, the laminate 2 and No delamination of the surface layer 6 occurs. Therefore, expansion of delamination between the surface layer 6 and the laminate 2 can be further prevented by the sewing portion 10.

  Further, the sewing portion 10 is sewn along the entire circumference of the peripheral edge portion 12. Thereby, even if a part of the outer side of the peripheral portion 12 of the surface layer 6 is peeled off, the sewing portion 10 stitches the surface layer 6 to the laminated body 2 at the peripheral portion 12. 2 and the surface layer 6 do not delaminate. Therefore, expansion of delamination between the surface layer 6 and the laminate 2 can be further prevented by the sewing portion 10. Further, when deformation due to bending occurs in the cushioning material 1 for hot press, the layers 2 and the surface layer 6 are stitched together more firmly, so that the layers follow each movement. Thereby, the rubber of the rubber layer 4 does not come off from the unevenness of the intermediate layer 5 and the surface layer 6, the anchor effect of the rubber layer 4 is further maintained, and the delamination of the laminate 2 and the surface layer 6 can be further prevented. it can.

  The sewing thread 11 is para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber. That is, the sewing thread 11 is a heat-resistant fiber having high strength and high elasticity. Thereby, the sewing thread 11 has high strength, and the layers 2 and the surface layer 6 can be firmly stitched together without the sewing thread 11 being cut. When the hot press cushioning material 1 is deformed by bending, Moreover, each layer can be made to follow each movement. Therefore, the bending durability of the heat press cushioning material 1 can be ensured. And delamination of the laminated body 2 and the surface layer 6 can be prevented. Further, since the sewing thread 11 is highly elastic and soft, the pressure distribution of the sewing portion 10 is not affected. Therefore, the cushioning properties of the hot press cushioning material 1 can be maintained. Furthermore, since the sewing thread 11 has heat resistance, it does not deteriorate even in a high temperature use environment where hot pressing is performed, and generation of feathers is extremely small.

  The sewing thread 11 has a tensile strength of 2530 cN or more. The length of the seam 11a of the sewing thread 11 is 1.5 to 3.0 mm. Thereby, the sewing thread 11 has moderately high strength and high elasticity. Moreover, each layer of the laminated body 2 and the surface layer 6 is firmly sewn together by the stitches 11a having an appropriate length. And when deformation | transformation by bending arises in the cushion material 1 for hot presses, delamination can be reliably prevented in a bending location.

  The sewing thread 11 has a total fineness of 555 to 1332 dtex. Thereby, since the sewing thread 11 has an appropriate elasticity, the pressure does not concentrate on the sewing thread 11 during hot press, and the pressure distribution of the sewing portion 10 is not affected.

  Further, the surface layer 6 is impregnated inside the warp 61 and the weft 62, and adheres to the surface of the woven fabric with such a thin thickness that the warp 61 and the weft 62 cross each other and do not cover the irregularities formed on the surface. A heat-resistant resin 63 is included. As a result, the gap formed by the warp yarn 61 and the weft yarn 62 intersecting the surface layer 6 is present without being covered with the heat-resistant resin, so that the surface roughness of the surface layer 6 increases, and the hot press machine It is possible to improve the releasability with the like. In addition, since the unevenness | corrugation of the surface layer 6 is hard to lose | disappear even after repeatedly using the cushion material 1 for hot presses, mold release property with a hot press board etc. can be maintained favorable. In addition, the surface layer has a large surface roughness and there are many gaps in the surface layer. However, due to the anchor effect of the heat-resistant resin impregnated in the surface layer and the rubber layer laminated inside the surface layer, The rubber is infiltrated into the gap between the surface layers, the gap between the surface layers is closed and the ventilation is blocked, the airtightness can be increased, and suction conveyance is possible. Furthermore, since the amount of the heat-resistant resin is small, the hardness of the cushioning material for hot pressing is reduced, and the flexibility of the cushioning material for hot pressing is provided, so that the press object can be prevented from warping.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment and an Example. The scope of the present invention is shown not only by the above description of the embodiments and examples but also by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, in the said embodiment, the sewing part 10 is sewn with the sewing thread | yarn 11 along the perimeter of the peripheral part 12 of the surface of the both sides of the surface layer 6 laminated | stacked on the surface of the both sides of the laminated body 2. . However, the sewing part 10 is sewn with the sewing thread 11 along a part (for example, two opposite sides) of the peripheral edge part 12 on the both surfaces of the surface layer 6 laminated on the both surfaces of the laminate 2. It may be configured.

  For example, in the above-described embodiment, the heat resistant resin 63 is formed of the woven yarn (warp yarn 61, warp yarn 61, warp 61, as shown in FIG. 3 (a) before pressing and FIG. 3 (b) after repeated use. Impregnated into the weft yarn 62) and impregnated with a predetermined content that adheres thinly to such an extent that the warp yarn 61 and the weft yarn 62 cross each other and do not cover the irregularities formed on the surface (the degree to retain the irregularities). . However, the heat resistant resin 63 does not have to be impregnated inside the woven yarn (warp yarn 61, weft yarn 62) constituting the fabric 60. Further, the heat resistant resin 63 may be impregnated to the extent that the warp 61 and the weft 62 intersect before and after pressing to cover the irregularities formed on the surface.

  Moreover, in the said embodiment, FIG. 4 is a schematic diagram, and ratio of the actual length of the horizontal direction of the hot press cushioning material 1, the vertical direction, and the thickness direction may differ from the thing of FIG. The same applies to the predetermined length W and the length L of the seam 11a described later.

[Cushion material for heat press]
First, materials used in the hot press cushioning materials of the examples, reference examples, and comparative examples will be described. In addition, the reference example was used in order to search the preferable range of an Example.
As an example, a reference example, and a comparative example, a laminate in which three rubber layers 4 and two intermediate layers 5 interposed between the rubber layers 4 are laminated between the two surface layers 6. The cushioning material 1 for hot press which arrange | positioned 2 was used.

  As the rubber composition used in the rubber layer 4, a polyol vulcanized fluororubber composition (Viton (registered trademark) V9006 manufactured by DuPont) was used. In addition, a double woven glass cloth (KS4325 manufactured by Nittobo) made of crimped fibers was used as the multi-woven cloth used in the intermediate layer 5. Further, PTFE impregnated glass cloth was used as the fabric 60 impregnated with the heat resistant resin 63 used in the surface layer 6. Here, the PTFE-impregnated glass cloth is a glass cloth obtained by impregnating a woven fabric (cloth) woven with woven yarns (warp yarn 61 and weft yarn 62) based on glass fibers with a fluororesin. Since the glass fiber is excellent in heat resistance, has high strength and high elasticity, and is impregnated with a fluororesin, the surface layer 6 excellent in heat resistance and low compression set can be formed.

  And in an Example, a reference example, and a comparative example, after heat-processing the textiles (glass cloth) impregnated with the heat resistant resin used as the surface layer 6 at the temperature of 405 degreeC beforehand, these rubber layers 4, the intermediate | middle layer 5, and After laminating the surface layer 6 and leaving it in a normal press vulcanizer at a temperature of 170 ° C. for 12 minutes in a non-pressurized state, the surface pressure was increased to 1.6 MPa at the same temperature and the press time was 12 minutes. Was press vulcanized. Then, the sewing part 10 is sewn with a sewing thread 11 of heat-resistant fibers along the entire circumference of the peripheral edge part 12 on the surface on both sides of the surface layer 6 laminated on the surface on both sides of the laminate 2 with a sewing machine. Configure. Thus, cushioning materials 1 for hot presses of Examples, Reference Examples and Comparative Examples were produced. In the examples, reference examples and comparative examples, the material of the sewing thread 11 used in the heat press cushioning material 1, the configuration and total fineness of the sewing thread 11, the tensile strength of the sewing thread 11, the seam 11a of the sewing thread 11, and the seam 11a of the sewing thread 11 The length and the sewing position (length from the surface end of the surface layer 6 to the inside) are changed. The material of the sewing thread 11, the configuration and total fineness of the sewing thread 11, the tensile strength of the sewing thread 11, the seam 11a of the sewing thread 11, and the length of the seam 11a of the sewing thread 11 Table 1 shows the sewing position (length from the surface end of the surface layer 6 to the inside).

A bending durability test, a pressure distribution evaluation test, and a press durability test were performed using the hot press cushion material 1 of the examples, reference examples, and comparative examples manufactured as described above.
In the bending durability test, the cushioning material for hot press 1 was cut into a rectangle having a size of 25 mm in length and 140 mm in width to prepare an evaluation sample. Further, in the bending durability test, the sewing portion 10 was formed by sewing along a part of the entire circumference of the peripheral edge portion 12 on the inner side by a predetermined length from the end of the surface of the surface layer 6. Specifically, the sewing portion 10 was formed by sewing along only two lateral sides of the peripheral edge portion 12.
In the pressure distribution evaluation test and the press durability test, the hot press cushion material 1 was cut into a rectangular shape with dimensions of 250 mm in length and 250 mm in width to prepare an evaluation sample. Further, in the pressure distribution evaluation test and the press durability test, the sewing portion 10 was formed by sewing along a part of the entire circumference of the peripheral edge portion 12 on the inner side of the predetermined length from the end of the surface of the surface layer 6. Specifically, the sewing portion 10 was formed by sewing along only two lateral sides of the peripheral edge portion 12.
In addition, 12 types of examples, 11 types of reference examples, and 1 type of evaluation samples were prepared, and a bending durability test, a pressure distribution evaluation test, and a press durability test were performed, respectively.

[Bending durability test]
In the bending durability test, the distance between the fixed gripper and the movable gripper of the dematcher bending tester was set to 75 mm, and the stroke was set to 40 mm. The evaluation sample was attached and bent 400 times. Then, at the end of the bending 200 times and after the completion of 400 times, the bending portion of the evaluation sample was observed, and the presence or absence of delamination between the laminate 2 and the surface layer 6 was confirmed. The evaluation in the bending endurance test was made into three grades: ○ when there was no delamination at the bent portion, delamination was observed at the bent portion, Δ when there was no practical problem as a product, and delamination at the bent portion The case was marked with x. Table 2 shows the evaluation results in the bending durability test of the evaluation samples of Examples, Reference Examples and Comparative Examples.

[Pressure distribution evaluation test]
In the pressure distribution evaluation test, a pressure measurement film for low pressure (size 270 mm) was sandwiched between 300 mm and 2 mm thick stainless steel plates, and an evaluation sample was stacked thereon. They were pressurized with a hydraulic hand press at a pressure of 3 MPa for 10 seconds. After pressurization, the pressure measurement film was taken out and the presence or absence of a sewing mark by the sewing unit 10 was confirmed. The evaluation in the pressure distribution evaluation test is made in three stages, ○ when there is no sewing trace on the pressure measurement film, sewing trace is recognized on the pressure measurement film, △ when there is no practical problem as a product, sewing on the pressure measurement film When there was a mark, it was set as x. Table 2 shows the evaluation results in the pressure distribution evaluation test of the evaluation samples of Examples, Reference Examples and Comparative Examples.

[Press durability test]
In the press durability test, the evaluation sample was continuously pressed 100 times under the following program conditions using a vacuum press. Under the program conditions, one cycle consists of pressurizing to 3 MPa, raising the temperature to 230 ° C. over 60 minutes, holding at 230 ° C. for 60 minutes, cooling to 50 ° C. over 30 minutes, and then reducing the pressure to 0 MPa. It was. This process was repeated 100 cycles. After pressing, it was confirmed whether there was any abnormality in the sewing portion 10 of the evaluation sample. The evaluation in the press durability test was made into three stages. The case where there was no scorching or melting of the thread in the sewing part 10 was observed, and the scoring or melting of the thread was slightly observed in the sewing part 10, but this was a practical problem as a product. The case where there was no △ was marked as Δ, and the case where the sewing part 10 was burned or melted was marked as x. Table 2 shows the evaluation results in the press durability test of the evaluation samples of Examples, Reference Examples and Comparative Examples.

[Examination of bending durability test]
Further, based on the results of the bending durability test in Table 2, the bending durability of the hot press cushioning material 1 was examined.
First, a case where the sewing position of the sewing thread 11 is 1.5 mm (Reference Example 5) and a case where the sewing position of the sewing thread 11 is 8 mm (Reference Example 6) are practically used as products at the bent portion. It was confirmed that there was no problem of delamination. From this, it can be inferred that the sewing position should be in the range of 3 to 5 mm in order to ensure the bending durability of the cushion material 1 for hot press and prevent delamination.
Next, it was confirmed that when the stitch length of the sewing thread 11 is 6 mm (Reference Examples 1, 2, 4, 7, and 8), delamination that does not cause a problem as a product occurs at the bent portion. Even if the length of the seam 11a of the sewing thread 11 is 6 mm or less, when the tensile strength of the sewing thread 11 is low (for example, Reference Example 10 (810 cN), Reference Example 11 (740 cN)), there is a practical problem as a product. It was confirmed that no delamination occurred. From this, in order to ensure the bending durability of the hot press cushioning material 1 and prevent delamination, the length of the seam 11a of the sewing thread 11 is in the range of 1.5 to 3 mm, and It can be inferred that the tensile strength of the sewing thread 11 may be 2530 cN.

[Examination of pressure distribution evaluation test]
Moreover, based on the result of the pressure distribution evaluation test of Table 2, the pressure distribution of the cushioning material 1 for hot press was examined. As a result, it was confirmed that when the total fineness of the sewing thread 11 exceeds 3000 dtex (Reference Examples 3, 4, and 9), a sewing mark having no practical problem as a product remains on the pressure film. From this, it can be inferred that the total fineness of the sewing thread 11 may be in the range of 555 to 1332 dtex in order to maintain the cushioning property of the heat press cushioning material 1.

[Examination of press durability test]
Moreover, based on the result of the press durability test of Table 2, the press durability of the cushion material 1 for hot press was examined. As a result, when the material of the sewing thread 11 is cotton (Reference Example 10) or polyester (Reference Example 11), the sewing part 10 may be slightly burnt or melted to the extent that there is no practical problem as a product. confirmed. On the other hand, in Examples 1 to 12 where the material of the sewing thread 11 was para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, and fluorine fiber, it was confirmed that there was no abnormality in the sewing part 10. Therefore, in order to ensure the bending durability of the heat press cushion material 1 over a long period of time, the material of the sewing thread 11 may be para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber. It can be inferred.

[Discussion]
From the above, in order for the hot press cushioning material 1 to maintain the cushioning property and to ensure the bending durability and prevent delamination between the laminate 2 and the surface layer 6, the sewing position is the surface layer surface. It has become clear that the range of 3 to 5 mm from the end to the inside is sufficient. Moreover, it became clear that the sewing thread 11 of the sewing part 10 should just be a para-aramid fiber, a polyarylate fiber, PBO fiber, PPS fiber, or a fluorine fiber. It has also been clarified that the sewing thread 11 of the sewing portion 10 has a tensile strength of 2530 cN or more and the length of the seam 11a may be 1.5 to 3.0 mm. Moreover, it became clear that the sewing thread 11 of the sewing part 10 should just have a total fineness of 555-1332 dtex.

  By using the present invention, it is possible to provide a cushioning material for hot press that can maintain the cushioning property, ensure the bending durability, and prevent delamination between the laminate and the surface layer.

DESCRIPTION OF SYMBOLS 1 Heat press cushion material 2 Laminated body 4 Rubber layer 5 Intermediate layer 6 Surface layer 10 Sewing part 11 Sewing thread 11a Seam 12 Peripheral part 20 Hot press board 60 Fabric 61 Warp 62 Weft 63 Heat resistant resin

Claims (7)

A hot press cushioning material used between a hot press machine and a press object,
The rubber layer is composed of at least two rubber layers and a bulky multi-woven cloth interposed between the rubber layers, and is formed on the surface of the multi-woven cloth so that the rubber of the rubber layer is infiltrated, and the multi-layer A laminate formed by laminating an intermediate layer having a void formed inside the woven cloth, and
Laminated on the surfaces of both sides of the rubber layer on the outermost side of the laminate, made of a woven fabric or a knitted fabric having a thread made of a heat resistant fiber member, and a surface layer having a heat resistant resin;
All of the peripheral portions of the surfaces on both sides of the surface layer laminated on the surfaces on both sides of the laminate so as to penetrate the laminate and the surface layer in the thickness direction in which the laminate and the surface layer are laminated. A sewing portion sewn with a sewing thread made of a heat-resistant fiber material along at least a part of the circumference;
A heat press cushioning material comprising:   The said peripheral part is a part from 3 mm or more to 5 mm or less inward from the edge of the surface of the said surface layer, The cushion material for hot presses of Claim 1 characterized by the above-mentioned.   The cushion material for hot press according to claim 1 or 2, wherein the sewing portion is sewn along the entire circumference of the peripheral portion.   The cushion for hot press according to any one of claims 1 to 3, wherein the sewing thread is para-aramid fiber, polyarylate fiber, PBO fiber, PPS fiber, or fluorine fiber. Wood.   The sewing thread has a tensile strength of 2530 cN or more, and the length of a seam that is a part of the sewing thread formed on the surface layer of the sewing portion is 1.5 to 3.0 mm. The cushioning material for hot press according to any one of claims 1 to 4, wherein:   The cushion material for hot press according to any one of claims 1 to 5, wherein the sewing thread has a total fineness of 555 to 1332 dtex.   The heat-resistant resin is impregnated in the inside of the yarn, and is attached to the surface of the woven or knitted fabric so as not to cover the unevenness formed on the surface by crossing the yarn. The cushion material for hot presses as described in any one of Claims 1-6.