JPWO2008047402A1 - Sheet elastic body - Google Patents

Abstract

Provided is a sheet-like elastic body that can have both good sealing properties due to flexibility and elasticity and scratch resistance. In the sheet-like elastic body comprising the required sheet-like elastic foamed substrate 12, the entire one surface 12a in the thickness direction of the sheet-like elastic foamed substrate 12 is covered with the required resin composition R, and the surface layer of the surface 12a The resin composition R is present in the cell 28 defined by the foam skeleton 13 constituting the sheet-like elastic foam substrate 12, and the sheet-like elastic foam substrate 12 and the composition are formed on the surface layer portion of the surface 12a. The resin composition existence area | region 14 with which R was integrated is formed.

Description

  The present invention relates to a sheet-like elastic body, and more particularly to a sheet-like elastic body suitably used as a sealing material such as a gasket or packing for electronic equipment, precision equipment and the like.

For example, devices such as a liquid crystal display unit are arranged in a display or the like in a general household appliance, a mobile phone, or a portable information terminal so as to face the outside of the housing. In such a device, for example, a seal member is interposed between the casing and the peripheral edge of the casing to prevent dust prevention, light leakage of the backlight, rattling, and the like. As such a seal member, as described in Patent Document 1, a polyurethane foam that is easily deformed under a low load and integrally formed with a film material on one side has been reported.
JP 2001-100216 A

By the way, with the improvement in function and weight reduction required for recent cellular phones and the like, the above-mentioned required characteristics for the seal member have also been advanced. This has been achieved by improving the functions of the ICs used, increasing the degree of member integration by unifying the IC sizes, saving space by introducing large-scale LSIs, and multi-layered substrates. When a large number of parts are integrated in this way, the structure and the fitting structure of the housing become complicated. In order to cope with this, as described in Patent Document 2, a sealing member has been devised that ensures a sufficient sealing performance in a wide compression rate range at the same thickness.
JP 2005-227392 A

  However, in the invention described in Patent Document 2, while the sealing property is good, the scratch resistance is low due to the flexibility. For this reason, if the handling is rough, there is a problem that the seal member is easily damaged. This damage causes a secondary problem in which the sealing performance is deteriorated and peeling pieces from the damaged seal member remain on the liquid crystal screen, for example, to lower the commercial value.

  In view of the problems inherent in the sheet-like elastic body according to the prior art, the present invention has been proposed to suitably solve these problems, and has excellent sealing properties due to flexibility and elasticity, and scratch resistance. It aims at providing the sheet-like elastic body which can have both nature.

In order to overcome the above-mentioned problems and achieve the intended object, the sheet-like elastic body of the present invention is a sheet-like elastic body comprising a sheet-like elastic foam substrate,
The entire one surface in the thickness direction of the sheet-like elastic foam substrate is covered with a resin composition,
In the surface layer portion of the surface, the resin composition is present in a cell defined by a foam skeleton constituting the sheet-like elastic foam substrate,
Thus, the gist is that a resin composition existing region in which the sheet-like elastic foam base and the resin composition are integrated is formed in the surface layer portion.

  Therefore, according to the invention which concerns on Claim 1, while maintaining low hardness under high compression, while exhibiting suitable sealing performance under a wide compression state, scratch resistance can be expressed.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the resin composition existence region is that the resin composition and the foam skeleton are fused at a contact site.
Therefore, according to the invention which concerns on Claim 2, while maintaining low hardness even under high compression, while exhibiting suitable sealing performance under a wide compression state, scratch resistance can be expressed.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the resin composition existing region is formed of (1) stainless steel as the material of the contact pressing body based on JIS K 7218, and (2) The gist is that the load is 1.2 kg, and (3) it has a resistance of 10 revolutions or more in an evaluation performed under the condition of 43 revolutions / minute.
Therefore, according to the invention of claim 3, sufficient scratch resistance is ensured.

In order to overcome the above-mentioned problems and achieve the intended object, a sheet-like elastic body according to another invention of the present application is a sheet-like elastic body provided with a sheet-like elastic foam substrate,
The sheet-like elastic foam substrate has a 50% compressive load of 0.025 MPa or less and a 75% compressive load of 0.40 MPa or less.
The entire one surface in the thickness direction of the sheet-like elastic foam substrate is covered with a resin composition,
As a result, the sheet-like elastic foam substrate and the resin composition are integrated with the surface layer portion of the surface. Based on JIS K 7218, the material of the contact pressing body is (1) stainless steel, and (2) the load is The gist is that a resin composition existence region having a resistance of 10 revolutions or more is formed in an evaluation carried out under the condition of 1.2 kg and (3) revolutions of 43 revolutions / minute.

  Therefore, according to the invention which concerns on Claim 4, while maintaining low hardness also under high compression, while exhibiting suitable sealing performance under a wide compression state, scratch resistance can be expressed.

The gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4, the thickness of the resin composition existing region is in the range of 1 to 25 μm.
Therefore, according to the invention which concerns on Claim 5, the maintenance of the low hardness under high compression and sufficient expression of scratch resistance are ensured.

The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the tensile strength of the resin composition according to JIS K 6251 is in the range of 1.0 to 80 MPa. Is the gist.
Therefore, according to the invention which concerns on Claim 6, expression of sufficient scratch resistance is ensured.

The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the elongation defined in JIS K 6251 in the substance constituting the resin composition existing region is the sheet-like elastic foam substrate. It is summarized that the elongation is not less than the elongation specified in JIS K 6251.
Therefore, according to the invention which concerns on Claim 7, sufficient scratch resistance is ensured.

  As described above, according to the sheet-like elastic body according to the present invention, a sheet-like elastic body that maintains a low hardness under high compression and has sufficient scratch resistance can be produced.

It is sectional drawing which shows the internal structure of the sheet-like elastic body which concerns on the suitable Example of this invention. It is process drawing which shows the manufacturing method of the sheet-like elastic body which concerns on an Example. It is the schematic which shows an example of the manufacturing apparatus of the sheet-like elastic body which concerns on an Example. It is sectional drawing which shows the film for resin composition transfer which concerns on an Example. It is sectional drawing which shows the film for resin composition transfer which a resin composition presence area | region consists of two layers. The state diagram which shows roughly the state in each process, such as an elastic foam base material, a sheet-like elastic foam base, a resin composition existence region, and a substrate film, used when manufacturing a sheet-like elastic body concerning an example It is. It is sectional drawing which shows the internal structure of the sheet-like elastic body which concerns on the example of a change. It is the schematic which shows the manufacturing apparatus of the sheet-like elastic body which concerns on the example of a change. It is the schematic which shows the manufacturing apparatus of the sheet-like elastic body which concerns on another modification. It is a whole schematic diagram which shows the test apparatus used for evaluation of scratch resistance implemented in Experiments 1-3.

  Next, the sheet-like elastic body according to the present invention will be described below with reference to the accompanying drawings by way of preferred examples. The inventor of the present application presents a resin composition in which the base and the required resin composition are integrated on the surface layer portion of one surface of the sheet-like elastic foam base capable of ensuring a sufficient sealing performance with a small thickness. It has been found that by forming the region, it is possible to obtain a sheet-like elastic body that does not inhibit the physical properties of the substrate and achieves the required scratch resistance. This sheet-like elastic body is suitably used for a housing fitting portion of a mobile phone or the like, and prevents the product value from being lowered due to improvement in sealing performance and handling performance and damage. Here, the physical properties of the sheet-like elastic foamed substrate include (A) 50% compression load (hereinafter referred to as 50% CLD) and 75% compression load (hereinafter referred to as 75% CLD), which are not more than a certain value, respectively. Or (B) Density set to a certain value or less. These (A) and (B) are both indices for achieving low hardness under high compression conditions in the present invention. One surface refers to a surface on the side that receives rubbing or the like due to fitting of the housing or the like. Further, “the resin composition is present in the cell” in the present invention refers to a state in which the resin composition has entered at least part of the cell. The phrase “the resin composition and the foam skeleton are fused at the contact site” refers to a state in which the resin composition and the foam skeleton are mixed and integrated by eliminating the boundary due to compatibility.

  The evaluation of the scratch resistance of the present invention is basically performed based on JIS K 7218. In this evaluation, (1) the material of the contact pressing body is stainless steel, (2) the load is 1.2 kg, and (3) the rotation speed is 43 rotations / minute (details will be described later [0027]: It is called evaluation condition). In this evaluation, having durability means a state in which there is no visible scratch on the side where the resin composition existence region of the sheet-like elastic body is formed at the end of the constant rotation performed under the evaluation conditions. In the present invention, from the knowledge obtained from Experiment 1 (described later), the boundary for judging the scratch resistance is 10 rotations under the evaluation conditions. That is, if there is no problem with the sheet-like elastic body that is the evaluation object after 10 revolutions, it is determined that the sheet-like elastic body has scratch resistance.

  As shown in FIG. 1, the sheet-like elastic body 10 according to the embodiment is formed on (a) a sheet-like elastic foam base (hereinafter simply referred to as a base) 12 and a surface layer portion on one surface 12a of the base 12. (b) Basically composed of a resin composition existing region 14 and (c) a base film 18 laminated on the other surface (back surface) of the base 12 opposite to the resin composition existing region 14. The Here, (a) the substrate 12 achieves the required flexibility and sealing properties, and (b) the resin composition existing region 14 is composed of the foam skeleton 13 and the resin composition (hereinafter simply referred to as composition) that define the cells 28. In the region where R is integrated, the required scratch resistance is expressed, and (c) the base film 18 plays a role of improving the structural strength of the sheet-like elastic body 10. The integration of the foam skeleton 13 and the composition R means that the composition R exists in (enters) the cell 28 and is fused at the contact site with the foam skeleton 13 that defines the cell 28. Refers to the state. Here, the composition R only enters the cell 28 and includes the state where the foam skeleton 13 and the composition R are not fused. The composition R is partially in the cell 28 in the surface layer portion of the surface 12a.

  The substrate 12 is preferably manufactured on the basis of a known mechanical floss method. That is, an elastic foam base material (hereinafter simply referred to as a raw material) M in which a predetermined amount of foaming gas is mixed with a resin raw material composed of polyol and isocyanate as main raw materials and a foam stabilizer as a secondary raw material, It is manufactured by continuously supplying onto the base film 18 also used as a transfer medium in (described later) and controlling the thickness. The mechanical floss method is described in detail in, for example, Japanese Patent Publication No. 53-8735. In the present embodiment, the foam has a semi-self foam structure. The substrate 12 is a known substance that has less material and gas generation and has flexibility, followability to a curved surface, etc. so as to maintain functions such as dust prevention and light leakage prevention over a long period of time. For example, a foam of a synthetic resin is suitable. Specific examples include foams made of various resins such as urethane, polystyrene, silicone, acrylic, and polyvinyl chloride, or various rubbers such as NBR, SBR, EPDM, and EPM.

The density of the substrate 12 is in the range of 50 to 250 kg / m ³ . By setting it as this range, even if the resin composition existence area | region 14 is formed in the surface layer part in the surface 12a, sufficiently low hardness can be maintained in a high compression state. When this value exceeds 250 kg / m ³ , the hardness becomes high and the sealing performance deteriorates. The lower limit of density varies depending on the production method (described later). When the base 12 is manufactured by the mechanical floss method, 100 kg / m ³ is the lower limit. If it is less than 100 kg / m ³ , the foaming gas is not uniformly mixed with the resin raw material, and the bubbles forming the cells 28 are not stably maintained, causing problems such as cell roughening and voids. This is because sex expression is inhibited. When the mechanical floss method and the chemical foaming method are used in combination, 50 kg / m ³ is the lower limit. However, if it is less than 50 kg / m ³ , the bubbles forming the cells 28 are not stably maintained. The thickness of the substrate 12 is preferably in the range of 0.3 to 5.0 mm. This lower limit is a numerical value for ensuring sufficient sealing performance under high compression. On the other hand, the upper limit is a numerical value empirically derived from use in a device that requires space saving, such as a mobile phone.

  The properties of the sheet-like elastic body achieved by this density and thickness can be expressed by 50% CLD and 75% CLD. In this case, the numerical values are 0.025 MPa or less and 0.40 MPa or less, respectively. 50% CLD and 75% CLD are the load required when applying physical compression of 50% and 75%, respectively, that is, the sheet-like elastic body 10 when applying physical compression of 50% and 75%, respectively. Represents the hardness. When this exceeds the above-mentioned value, it is too hard and the flexibility with respect to physical compression is inferior, and sufficient sealing performance cannot be achieved. Furthermore, the load applied to the housing is increased, and there is a possibility that the housing or the like may be distorted, cracked, chipped, or other physical defects during use. This hardness is basically a numerical value of the base 12. However, in the present invention, the resin composition existing region 14 is formed in the surface layer portion on the surface 12a, and the composition R and the base 12 are integrated to form an inseparable structure. Is the same.

  In addition, the diameter of the cell 28 of the substrate 12 is set to 500 μm or less, preferably 300 μm or less in order for the sheet-like elastic body 10 to exhibit suitable sealing properties. When this value exceeds 500 μm, the dustproof property and the light shielding property are lowered. In particular, in order to achieve the performance required for recent precision instruments without excess or deficiency, 300 μm or less is preferable. That is, in the case of 300 to 500 μm, although there is no problem in dust resistance, a slight light leakage may occur depending on the light source intensity. Moreover, since the sheet-like elastic body 10 according to the present embodiment is manufactured mainly by the mechanical floss method, a skin layer is provided on the surface unless post-processing or the like is performed. This is preferable from the viewpoint of improving the sealing property because it can structurally improve the adhesion to the object to be sealed.

The raw material M of the base 12 constituting the sheet-like elastic body 10 having such physical properties basically conforms to the contents described in Japanese Patent Publication No. 53-8735. And in order to make density etc. into the above-mentioned range, the mixing ratio of the foaming gas with respect to 100 parts by volume of the resin raw material consisting of polyol and isocyanate as the main raw material and foam stabilizer as the auxiliary raw material is set to 300% by volume or more. . If this is less than 300% by volume, the density of the sheet-like elastic body 10 does not become 250 kg / m ³ or less, and the sealing performance when a high compressibility is obtained cannot be ensured. When a chemical foaming method is used in combination, a foaming agent, a surfactant, a catalyst for delaying the curing of the substrate 12 under control, and the like are further used as auxiliary materials.

  The resin composition existing region 14 is basically a region where the composition R enters and is integrated into the cell 28 (void) in the surface layer portion of the surface 12a of the substrate 12, or the composition R enters the foam skeleton due to compatibility. This is a region where the boundary with 13 disappears and is integrated (see FIG. 1). By this fusion, the composition R forms a resin composition existing region 14 that is inseparable from the base 12 and exists as a single layer. Therefore, the presence of the resin composition existing region 14 does not deteriorate the physical properties related to the flexibility of the substrate 12.

  As the composition R, a required resin, preferably a material similar to that of the substrate 12, such as a urethane resin, is used. In addition, known substances such as resins such as acrylic, polyester, vinyl, epoxy, polyamide, and polystyrene, or various synthetic rubbers may be used singly or in combination. And the composition R is calculated | required that the tensile strength based on JISK6251 is the range of 1.0-80 Mpa. Thereby, the softness | flexibility of the sheet-like elastic body 10 which concerns on this invention, and the scratch resistance of the surface 12a are ensured. That is, when the tensile strength is less than 1.0 MPa, scratch resistance is not satisfied. On the other hand, if it exceeds 80 MPa, the flexibility of the sheet-like elastic body 10 as a whole deteriorates. Further, a substance having an elongation larger than the elongation of the substrate 12 (JIS K 6251) and having high compatibility with the material of the substrate 12 is preferably selected. The elongation is 50% or more, preferably 100% or more, compared to the material of the substrate 12 described above. Regarding the compatibility, it is preferable that the difference between the solubility parameters is 1.0 or less. By using such a resin or the like as a material, the following effects can be obtained. That is, at the time of manufacturing (α), the familiarity when forming the resin composition existence region 14 on the base 12 is improved to facilitate the fusion. Further, when (β) is used, the integral holding property (following property) of the resin composition existence region 14 to the base 12 is ensured.

  Further, the composition R is required to exhibit plastic flow when the sheet-like elastic body 10 is manufactured (heated) or the like. Here, the plastic flow refers to a flow in which each molecule constituting the polymer composition R enters only the surface layer portion of the surface 12a at a temperature equal to or higher than the glass transition point. A distinction is made between the state of plastic flow and the state of flow that occurs above the melting temperature. That is, the composition R that is not in a plastic flow state and remains in a glass state even when heated is not suitable because it does not enter the cell 28. In addition, the composition R that becomes a fluid state at a temperature equal to or higher than the melting temperature and has a low viscosity penetrates the entire substrate 12. For this reason, the composition R is not so preferable because the resin composition existence region 14 cannot be formed in the surface layer portion of the surface 12a and the physical properties such as the hardness of the sheet-like elastic body 10 are deteriorated. As the composition R that plastically flows as described above, for example, it is not completely melted by heating when producing a cross-linked resin that exhibits a certain fluidity without being melted by heat or a sheet-like elastic body 10. Thermoplastic resins are preferred. Production of a sheet-like elastic body 10 in which the composition R is integrated with the surface layer portion of the surface 12a without producing a plastic flow state and adversely affecting the physical properties of the substrate 12 by using a substance that achieves this condition. Can do.

  The resin composition existence region 14 has a thickness in the range of 1 to 25 μm, preferably 2 to 20 μm, and more preferably 3 to 10 μm. Here, the thickness is the thickness of the portion where the substrate 12 and the composition R are integrated, and represents the depth from the surface 12a to the position where the composition R exists (D in FIG. 1 or FIG. 7). reference). If the thickness is less than 1 μm, sufficient scratch resistance cannot be obtained, while if it exceeds 25 μm, the sealing property and cushioning property of the sheet-like elastic body 10 itself are impaired. This numerical range of thickness is derived based on knowledge obtained from Experiment 1 described later. That is, in the range of 3 to 10 μm, there is no problem in scratch resistance at the end of 100 rotations under the evaluation conditions, and the followability is good. Further, in the range of 2 to 3 μm or 10 to 20 μm, 30 rotations under evaluation conditions (the rotation that becomes the boundary region in the conventional sheet-like elastic body 10 in which the resin composition existence region 14 is not provided and a small scratch of less than 5 mm is confirmed) Number) At the end, there was no problem in scratch resistance, and there was no problem in followability.

  In the present invention, the scratch resistance required for the resin composition existing region 14 is evaluated under the required evaluation conditions. This evaluation condition is derived from the experimental result of the conventional sheet-like elastic body 10 in Experiment 1 (described later), and has the accuracy to determine the limit under actual use. Specifically, physical contact with the sealed member is expected due to external factors such as vibration and dropping, or product configuration when actually used as a sealing member (during product assembly or after assembly). This is a condition in which the situation can be taken into consideration and the contents that can be qualitatively and quantitatively evaluated under more severe conditions can be reproduced. That is, if there is no problem with this evaluation condition, it can be assumed that there is no problem even under actual use.

  The base film 18 is a member that is integrally laminated on the base 12 in order to improve the structural strength of the sheet-like elastic body 10. As described in the manufacturing method (described later), it also serves as a transfer medium for the raw material M. Therefore, the material of the base film 18 has a low thermal shrinkage, such as polyethylene terephthalate (PET), which has physical strength capable of resisting the tension applied at the time of manufacture and resistance to heat that causes the raw material M to react and cure. Use of various resins is preferable. In addition, the details conform to the contents described in [Patent Document 2].

(About manufacturing equipment and manufacturing method)
Next, the manufacturing apparatus of the sheet-like elastic body according to this embodiment and the manufacturing method using the apparatus will be described. The raw material M and the resin composition transfer film (hereinafter simply referred to as a transfer film) 20 (described later) are prepared. The sheet-like elastic body 10 is basically manufactured through the raw material preparation step S1, the raw material supply / resin composition application step S2, the heating step S3, the transfer film removal step S4 and the final step S5 shown in FIG. Manufactured by the device 30. The manufacturing apparatus 30 continuously performs the steps S2 to S5 described above, and the raw material preparation step S1 is separately performed in the mixing unit 31. Note that the raw material preparation step S1 is a step of preparing the transfer film 20 by preparing the raw material M of the substrate 12 by an appropriate conventionally known method. The details of the preparation of the raw material M and the detailed description of the manufacturing apparatus 30 conform to [Patent Document 2], and are therefore omitted.

(About film for resin composition transfer)
The transfer film 20 prepared in advance has a structure shown in FIG. In this embodiment, the layered material 15 is formed on the prepared transfer film 22 via the applied release agent 17. The layered product 15 is a composition R having a required thickness by a known gravure coater or the like. The coater to be used is appropriately selected depending on various conditions such as the thickness of the layered product 15 and the viscosity of the composition R. Here, the release agent 17 enhances the peelability of the layered product 15 from the transfer film 22. For example, known substances such as silicone, polyolefin, melamine, epoxy, ethylene-vinyl acetate-based or vinyl chloride-vinyl acetate-based resins or polyacetal are appropriately selected in the form of a simple substance or a mixture of several kinds. The transfer film 22 has physical strength capable of resisting tension due to a resin composition existing region application mechanism (hereinafter simply referred to as application mechanism) 35 and resistance to heat that causes the raw material M to react and cure. Various resins having a smooth surface and small thermal shrinkage such as PET are preferably used.

  In this embodiment, the layered product 15 is a single layer, but the present invention is not limited to this. As shown in FIG. 5, a second layered product 15b having a required thickness is formed from the second composition R2 on the transfer film 22 provided with the release agent 17, and the first composition is formed thereon. It is good also as a multilayer which provided R1 and formed the 1st layered product 15a of required thickness. In this case, by adopting a material that is compatible with both the base 12 and the second layer 15b as the material of the first layer 15a, the respective materials of the base 12 and the second layer 15b that do not contact with the base 12 are used. As such, substances that are not familiar to each other can be selected. For example, (a) an acrylic resin having scratch resistance as a material for the second layered material 15b on the outside and having, for example, gloss, (b) a polyurethane foam having excellent flexibility as a material for the substrate 12 is used. When used, a material having compatibility with both of them, such as urethane, acrylic, polyester, polyamide or various synthetic rubbers, is preferably employed as the first layered material 15a. In this case, the sheet-like elastic body 10 having suitable flexibility, scratch resistance and surface gloss can be obtained. Of course, the layered product 15 may have a structure of three or more layers as necessary.

  Further, when the layered product 15 has two or more layers, a material F (hereinafter referred to as a functional material) F that exhibits a required function can be mixed with the composition R, and this function can be imparted to the sheet-like elastic body 10. . This uses the composition R as a binder and imparts a specific function. Specifically, the second layered product 15b is formed from the second composition R2 mixed with the functional substance F on the transfer film 22 via the release agent 17, and the first composition is further formed thereon. This is done by forming the first layered product 15a only from the product R1 (see FIG. 5).

  By the way, the mixing of the functional substance F does not affect the surface physical properties such as scratch resistance, but deteriorates the volume physical properties such as tensile strength. For this reason, when the layered product 15 is a single layer, it is difficult to apply, and there is a problem that the layered product 15 is partially peeled from the transfer film 22 even when it is lightly contacted by an operator. This problem is particularly fatal in a state where the thickness is thin (25 μm or less) and the substance is not substantially bonded to another substance via the release agent 17 (see FIG. 4). However, if the layered product 15 has two or more layers, a so-called anchor effect appears between the first layered product 15a and the second layered product 15b, and this problem can be avoided. The same effect can be obtained when the functional substance F is mixed with either the first composition R1 or the second composition R2.

  The transfer film 20 shown in FIG. 4 and FIG. 5 is used in a form in which the upper and lower sides are interchanged when the film is applied to the raw material M by the manufacturing apparatus 30. In FIG. 5, the second layered material 15b mixed with the functional substance F is located on the transfer film 22 side, but the present invention is not limited to this. That is, the functional material F may be mixed with the first composition R1 to form the first layered product 15a containing the functional material F, and this may be covered and protected with the second layered product 15b. . In this case, not only the anchor effect but also a direct protective action by covering is added. Thus, when making the layered material 15 into a multilayer, it is preferable that thickness is 1 micrometer or more in consideration of the bondability etc. of both layers. When this value is less than 1 μm, the above-described anchor effect and covering protection effect are insufficient. The functions imparted by the functional substance F include all the characteristics imparted by substances such as known powders that can be mixed with the binder, such as coloring, hygroscopicity, conductivity, or electromagnetic shielding properties. . Further, since the first layered product 15a and the second layered product 15b formed as a multilayer are integrated with each other by heating, the resin composition existence region 14 is formed in the same manner as the single layered product 15.

  The manufacturing apparatus 30 shown in FIG. 3 basically conforms to the manufacturing apparatus described in [Patent Document 2]. That is, a roll mechanism 32 (supply roll 32a and product recovery roll 32b) for driving the base film 18, a discharge nozzle 34 for supplying the raw material M onto the film 18, and a product thickness control for setting the raw material M to a predetermined thickness downstream thereof. It comprises means 36 and this downstream heating means 38. As shown in FIG. 6A, the discharge nozzle 34 supplies the raw material M onto the base film 18 under control, and one end thereof is connected to the mixing unit 31 that performs the raw material preparation step S1. As shown in FIG. 6B, the product thickness control means 36 functions as a roll that gives the raw material M the required thickness and also applies the transfer film 20 to the raw material M in a stacked manner under pressure. Note that various blades may be employed as the product thickness control means 36 to be independent of the applying mechanism 35. A supply roll 35a and a transfer film collection roll 35b for driving the transfer film 20 for applying the layered material 15 to the upper side of the raw material M are disposed upstream and downstream of the product thickness control means 36, respectively. A mechanism 35 is configured. The applying mechanism 35 is a mechanism that supplies the production line while applying tension to the transfer film 20 and collects only the transfer film 22. Here, the wound transfer film 20 is sent out from the supply roll 35a under control. By passing through this portion, the raw material supply / resin composition application step S2 is completed, and after passing through the transfer film collection roll 35b located on the downstream side of the heating means 38, the transfer film removal step S4 (see FIG. 6C). ) Is completed.

  In the heating means 38, the raw material M is heated under reaction to be reacted and cured to form the substrate 12, and the resin composition existence region 14 in which the layered product 15 (composition R) and the substrate 12 are integrated is formed. Is done. Here, the integration of the layered product 15 and the substrate 12 is very strong due to the change of the layered product 15 itself into a plastic flow state, the adhesion effect, and the reaction / curing of the raw material M. In addition, the base film 18 is firmly bonded to the substrate 12 and integrally laminated by an adhesive effect by reaction and curing of the raw material M by heating. The heating temperature by the heating means 38 is set to a temperature range in which the layered product 15 changes to a plastic flow state. Specifically, the raw material M is heated to about 150 to 200 ° C., which can be reacted and cured. The heating step S3 is completed by passing through the heating means 38.

  The final step S5 is a step of obtaining a long object of the sheet-like elastic body 10 basically through the steps S1 to S4 so far. If necessary, the final product is punched into a predetermined sealing material shape and further subjected to final inspection and the like. The sheet-like elastic body 10 may be shipped in a form of being wound and collected by the product collection roll 32b while performing the final inspection. In this case, the sheet-like elastic body 10 is continuously manufactured as a long object, and the manufacturing cost can be greatly reduced. In the production of the sheet-like elastic body 10, an adhesive having a melting point of 60 to 150 ° C., such as a hot melt type such as polyvinyl chloride, polyvinyl acetate, polyolefin or acrylic resin, is provided on the raw material M side of the transfer film 20. May be applied by known means such as spray coating. Since this adhesive is cured through the heating step S3, the integration of the substrate 12 and the layered product 15 (composition R) can be further strengthened. Here, when the melting point is less than 60 ° C., for example, there is a risk of causing adverse effects such as blocking in high temperature production such as in summer. On the other hand, when it exceeds 150 ° C., it does not melt in the heating step S3, and a sufficient adhesive effect cannot be expected. Moreover, you may utilize the product which uses the base | substrate 12 manufactured previously or marketed as the base | substrate 12. FIG.

  In addition, the mechanical floss method and the chemical foaming method described above can be used in combination. In this case, a chemical foaming agent is used as an auxiliary material for the material M. The (chemical) foaming agent is water in particular, and a surfactant or catalyst suitable for the foaming agent may be used in combination with various auxiliary materials suitable for the conventional mechanical froth method. In particular, it is preferable to control the curing reaction of the raw material M by selecting a catalyst, and it is used at 0.1 to 8% by weight of the total amount of the main raw material in the raw material M. In addition, azo compounds, substituted hydrazines, semicarbazides, triazoles, benzoxazines or sodium carbonate / citric acid mixtures are used as (chemical) blowing agents. The amount of the foaming agent is adjusted according to the drug and the desired foam density, and is usually 0.1 to 10% by weight of the total amount of the main raw material in the raw material M. One or several physical foaming agents may be used in combination with the aforementioned (chemical) foaming agent. Examples of the physical foaming agent include fluorocarbons, fluoroethers, hydrocarbons such as pentane, ethers and esters. Further, materials containing partially halogenated hydrocarbons, ethers or esters are also included. A typical physical blowing agent has a boiling point of -50 to 100 ° C. The physical foaming agent is used in an amount sufficient to give the obtained foam a desired bulk density, usually 5 to 50% by weight of the total amount of the main raw material in the raw material M. In one embodiment, water ((chemical) blowing agent) is used with one or more physical blowing agents.

  Catalysts include bismuth, lead, tin, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese or zirconium organic acid salts, inorganic acid salts or Organometallic derivatives, phosphines, tertiary organic amines and the like can be mentioned. In particular, iron (metal) acetylacetonate (FeAA) is preferred because of its stability, good catalytic activity and nontoxicity. By adding acetylacetone (2,4-pentanedione) to this FeAA, it is possible to provide an effect of avoiding early curing at a low temperature and a high catalytic effect at the time of heating by the heating means 38. Here, the weight ratio of FeAA to acetylacetone is 2: 1, and the amount of catalyst present in the reactive composition is 0.03 to 3.0% by weight based on the weight of the active hydrogen-containing component. A surfactant such as an organic silicone surfactant may be used for the purpose of stabilizing the raw material M (substrate 12) before curing. The preferred molar ratio of silicate units to trimethylsiloxy units is 0.8: 1 to 2.2: 1. In addition, conventional organic polysiloxane-polyoxyalkylene block copolymers can be used. In addition, fillers (alumina trihydrate, silica, talc, calcium carbonate, clay, magnesium hydroxide, etc.), dyes, pigments (eg titanium dioxide and iron oxide), antioxidants, antiozonants, flame retardants, UV Any commonly used additive such as a stabilizer, conductive filler, conductive polymer, etc. may be added to the raw material M.

(Change example)
In the embodiment described above, the base film 18 is laminated on the sheet-like elastic body 10 to improve the structural strength and improve the handleability of the product. However, this does not exist in the present invention, and specifically, it may be a form like a sheet-like elastic body 24 shown in FIG. The sheet-like elastic body 24 is manufactured by, for example, a manufacturing apparatus 50 shown in FIG. The manufacturing apparatus 50 has the same structure as the manufacturing apparatus 30 except that the roll mechanism 32 includes a supply roll 32a, a product recovery roll 32b, and a base film recovery roll 32c. Further, the recovered base film 18 may be reused.

(Another change example)
In addition, the sheet-like elastic body 24 may be manufactured by using the manufacturing apparatus 60 shown in FIG. 9 to reverse the positions of the base film 18 and the transfer film 20 in the manufacturing apparatus 30. In this case, the surface protective film 19 is used in place of the transfer film 20 in order to form the sheet by controlling the thickness while pressing the raw material M from above to prevent surface roughness. Further, the transfer film 20 is wound around the supply roll 32a provided in the roll mechanism 32, and the base film recovery roll 32c is used as a transfer film recovery roll. Further, a surface protection film roll mechanism 37 for supplying the surface protection film 19 by the supply roll 37a and recovering the surface protection film 19 by the surface protection film recovery roll 37b on the downstream side of the heating means 38 is disposed instead of the applying mechanism 35. The That is, the raw material M is molded in a state of being sandwiched from above and below by the transfer film 20 as a transfer medium and the surface protection film 16. The transfer film 22 may be collected and reused.

  In addition, in the case of manufacturing a sheet-like elastic body using both the mechanical floss method and the chemical foaming method according to this example of another modification, by using the surface protective film 19, the above-described raw material M is pressed from above. In addition to preventing surface roughness, it is possible to more efficiently lower the density of the sheet-like elastic body by preventing gas scattering caused by the chemical foaming method. In each example described above, the sheet-like elastic bodies 10 and 24 are continuously manufactured, but the present invention is not limited to this. For example, the transfer film 20 or the base film 18 having a length of about 5 m may be used, and the supply of the raw material M and the heating may be performed batchwise.

(Experimental example)
Below, the experiment example evaluated about the scratch resistance etc. about the sheet-like elastic body which concerns on this invention is shown.

(Experiment 1) Scratch resistance in a sheet-like elastic body A sheet-like elastic body (manufacturing method is described below) consisting only of a sheet-like elastic foam substrate according to each of measurement examples 1 to 7 having the physical properties shown in Table 1 below. This was prepared and processed into a circular sheet-like test piece S of φ50 × 1.0 mm. Then, the test piece S is installed in a test apparatus 80 as shown in FIG. 10, and based on JIS K 7218 (JIS K 7218 quasi-base), (1) the material of the contact pressing body 82 is stainless steel, 2) The scratch property was evaluated under the conditions of a load of 1.2 kg, (3) a rotation speed of 43 rotations / minute (rotation speed 50 mm / sec) or a rotation speed of 86 rotations / minute (rotation speed 100 mm / sec). . The scratch property was evaluated by removing the test piece S from the test apparatus 80 after performing rotation in increments of 10 to 10 to 100, and visually confirming the appearance, ○: no scratch, Δ: small scratch (5 mm Less than) and x: Evaluation was made in three stages: scratch (5 mm or more). The materials used are as follows. The rotational speed represents a speed at which a point arbitrarily set on the outer edge of the test piece S moves by a rotational motion.

(Method for producing sheet-like elastic body (sheet-like elastic foam substrate))
・ Symbol A series and B (by mechanical floss method)
100 parts of general-purpose polyether polyol, 3 parts of crosslinking agent (1,4 butanol), 20 parts of thickener (aluminum hydroxide), 0.1 part of metal catalyst (stannas octoate), foam stabilizer (trade name SZ A mixture is obtained from 5.0 parts of 1940 (silicone: Toray Dow). The mixture was then subjected to a foaming gas calculated to obtain the desired density under the condition of 0.1 NL / sec, and a polyisocyanate (crude MDI, which was set to have an isocyanate index of 0.9 to 1.1). NCO content: 31%) is mixed to obtain an elastic foam substrate material. And according to the manufacturing method mentioned above, the sheet-like elastic body was manufactured from the elastic foam base material.
Symbols C and D (by mechanical floss method + chemical foaming method)
Basically, it is the same as the mechanical floss method of the above-mentioned symbol A series and B, but 0.5 parts of water as a foaming agent is further used as a raw material (the required amount of foaming gas is added to the mixture of the symbol A series). A mixture of water and water is represented by symbol C, and a material obtained by adding water to symbol B is represented by symbol D).

(Result of Experiment 1)
The results are shown in the following Table 2 ((a) is 43 revolutions / minute, (b) is 86 revolutions / minute). From Table 2, in the sheet-like elastic foam substrate to which the resin composition existing region is not given, even when the hardness of the material is increased with a high density or the like, the scratch resistance of 30 rotations or more under the evaluation conditions is It could not be expressed. In the test piece S of 240 kg / ^{m 3} to be 250 kg / ^{m 3} or less is a density range of the present invention (measurement examples 2 and 5), has failed to check 20 rotates more scratch resistant.

On the other hand, in the materials of Measurement Examples 1 to 4, no problem has occurred in the usage as a sealing member of a mobile phone or the like, and in the material of Measurement Example 5, depending on the physical contact with the member to be sealed. Some damage was confirmed. That is, in the current use as a seal member, it is necessary to develop scratch resistance that can withstand a rotation speed of 10 rotations or more, and preferably scratch resistance that can withstand a rotation speed of 30 rotations or more. It was confirmed. In Table 2, as the result of the rotational speed of 43 or 86 rotations / minute, all results were “x” at 50 rotations or more, and therefore, 50 to 100 rotations are collectively shown.

(Experiment 2) Integral retainability (followability) by materials From the materials of Measurement Example 3 and Measurement Example 6 described in Experiment 1, the sheet-like elastic foam substrates of Measurement Example A ″ and Measurement Example C are respectively used. Eight pieces were produced respectively. And the measurement example A '' which formed the resin composition existence area | region with a thickness of 4 micrometers using the resin composition which consists of each raw material provided with each physical property (aj) shown in following Table 3 on it. -A to j and measurement examples Ca to j The sheet-like elastic bodies were produced one by one (20 sheets in total). Each sheet-like elastic body thus produced was subjected to the test described below to confirm and evaluate the integral retention (followability). In addition, the manufacturing method of the sheet-like elastic body followed the above-mentioned Example.

(Evaluation of integral retention (followability))
Using a φ10 round bar, the sheet-like elastic body was pressed from the side of the resin composition existing region so as to be recessed by 0.5 mm with 50% compression, and the occurrence of wrinkles during this pressing was visually confirmed. The visual results were evaluated in four stages: ◎: no wrinkles, ◯: wrinkles of less than 5 mm, Δ: wrinkles of 5-10 mm, and x: wrinkles of 10 mm or more. In this evaluation, when the integral holding property of the resin composition existing area is high, the resin composition existing area is closely deformed with respect to the deformation of the sheet-like elastic foamed substrate, and there is a geometric distortion on the outside. If it is not manifested or is low, the resin composition existing area cannot correspond to the deformation of the sheet-like elastic foamed substrate, and is an evaluation method utilizing the fact that a geometric distortion appears outside.

(Result of Experiment 2)
Table 4 (a) below shows the results of the measurement example A ″ system, and Table 4 (b) shows the results of the measurement example C system. From Table 4, it was confirmed that the resin composition existing region made of a material having low elongation has poor integral retention (followability).

(Experiment 3) Scratch resistance and integral retention (followability) depending on the thickness of the resin composition existing region From the material of Measurement Example 3 according to Experiment 1, 20 A ″ -based elastic foamed substrates were produced. Then, 20 sheets of C-based sheet-like elastic foam substrate were prepared from the material of Measurement Example 6. On top of that, the thicknesses shown in Tables 5 and 6 are also used, using materials having physical properties (a to j: 10 types) shown in Table 5 (A ″ series) and Table 6 (C series) below. Sheets according to Examples A ″ -1 to 16 and Comparative Examples A ″ -1 to 4, and Examples C-1 to 16 and Comparative Examples C-1 to C-4, to which the resin composition existing region was provided. A single elastic body was prepared (40 sheets in total). For the produced sheet-like elastic bodies according to the examples and comparative examples, the scratch resistance (rotation speed: 43 rotations / minute (partial rotation speed: 86 rotations)) performed in Experiment 1 and Experiment 2 were performed. We confirmed and evaluated the integrated retention (followability). In addition, the manufacturing method of a sheet-like elastic body followed the above-mentioned Example similarly to Experiment 2.

(Result of Experiment 3)
The results are shown in Tables 5 and 6 above. From Table 5 and Table 6, in any material sheet-like elastic foamed substrate, by setting the thickness of the resin composition existing region to 1 μm or more, it is possible to achieve 10 rotations or more in the evaluation condition and 25 μm or less. Thus, it was confirmed that good followability was developed. Further, by setting the thickness of the resin composition existing region to 2 μm or more, it was confirmed that the scratch resistance suitable for 30 rotations exceeded the scratch resistance level of the seal member suitably used at present. . Furthermore, by setting the thickness of the resin composition existing region to 3 μm or more, scratch resistance was confirmed even for 100 revolutions. In addition, for 3 μm, scratch resistance was confirmed even under the condition of the rotational speed of 86 revolutions / minute. Show it). Regarding the followability, “◎” was confirmed at 10 μm or less, and it was confirmed that the sheet-like elastic foamed substrate and the resin composition existing region were bonded with very high adhesion. In Comparative Examples A ″ -2 and 3 and Comparative Examples C-2 and 3, the thickness of the resin composition existing region is 3 μm. It was confirmed that there was a problem in (trackability).

The thickness of the resin composition existing region is fixed to 3 μm, each of the sheet-like elastic foam bases from the material of Measurement Example 1 in Experiment 1 and each of the sheet-like elastic foam bases from the material of Measurement Example 2, Three sheet-like elastic foam substrates were prepared from the material of Measurement Example 4, three sheet-like elastic foam substrates were prepared from the material of Measurement Example 5, and one sheet-like elastic foam substrate was prepared from the material of Measurement Example 7. Further, as shown in Table 7 below, a sheet-like elastic body provided with a resin composition existence region using each material having each physical property (ac: three types (measurement example 7 is only a)). Were produced one by one (13 sheets in total). Each of the produced sheet-like elastic bodies was observed and evaluated for scratch resistance (number of rotations 43 and 86 rotations / minute) and followability. As a result, in the sheet-like elastic bodies according to Measurement Example 5 and Measurement Example 7, no problems other than the scratch resistance exceeding the limit when the rotation speed exceeded 100 could not be confirmed.

Claims (7)

In a sheet-like elastic body comprising a sheet-like elastic foam substrate (12),
The entire one surface (12a) in the thickness direction of the sheet-like elastic foam substrate (12) is covered with the resin composition (R),
In the surface layer portion of the surface (12a), the resin composition (R) is present in the cell (28) defined by the foam skeleton (13) constituting the sheet-like elastic foam substrate (12),
Thus, the sheet-like elastic body is characterized in that a resin composition existence region (14) in which the sheet-like elastic foam substrate (12) and the resin composition (R) are integrated is formed on the surface layer portion. .   The sheet-shaped elastic body according to claim 1, wherein the resin composition existence region (14) is a fusion of the resin composition (R) and the foam skeleton (13) at a contact site.   Based on JIS K 7218, the resin composition existing area (14) is made of (1) stainless steel, (2) load of 1.2 kg, and (3) 43 rpm / The sheet-like elastic body according to claim 1 or 2, wherein the sheet-like elastic body has a resistance of 10 rotations or more in an evaluation carried out under the condition of minutes. In a sheet-like elastic body comprising a sheet-like elastic foam substrate (12),
The sheet-like elastic foam substrate (12) has a 50% compression load of 0.025 MPa or less and a 75% compression load of 0.40 MPa or less,
The entire one surface (12a) in the thickness direction of the sheet-like elastic foam substrate (12) is covered with the resin composition (R),
As a result, the sheet-like elastic foam substrate (12) and the resin composition (R) are integrated with the surface layer portion of the surface (12a), and the material of the contact pressing body is (1) stainless steel based on JIS K 7218. And (2) a load of 1.2 kg, and (3) a resin composition existence region (14) having a resistance of 10 revolutions or more formed in an evaluation performed under the condition of 43 revolutions / minute. A sheet-like elastic body characterized by being made.   The sheet-like elastic body according to any one of claims 1 to 4, wherein a thickness of the resin composition existence region (14) is in a range of 1 to 25 µm.   The sheet-like elastic body according to any one of claims 1 to 5, wherein the resin composition (R) has a tensile strength according to JIS K 6251 in a range of 1.0 to 80 MPa.   The elongation defined in JIS K 6251 in the material forming the resin composition existing region (14) is greater than or equal to the elongation defined in JIS K 6251 of the sheet-like elastic foam substrate (12). The sheet-like elastic body according to any one of 6.

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