JP2020157735A - Adhesive material - Google Patents

Abstract

To provide a molding that exhibits excellent adhesion on a water wet surface and in underwater use as well as in the air, and an adhesive material comprising the molding.SOLUTION: A molding contains a fiber structure having fibers of a columnar structure oriented in lengthwise direction with a number density of 103-1011/mm2, and a resin layer containing at least one resin selected from the group consisting of thermoplastic resin, thermosetting resin, and photocurable resin.SELECTED DRAWING: None

Description

The present invention relates to a molded product containing a fiber structure and a resin layer. The molded product of the present invention is particularly useful as an adhesive material.

Conventionally, as an adhesive tape for sticking to human skin such as medical use, an adhesive tape in which a rubber-based or acrylic-based adhesive is applied to a support such as cloth, Japanese paper, plastic film, or non-woven fabric is widely supplied. Has been done. The adhesive used for these adhesive tapes is appropriately selected from the viewpoints of flexibility, strength, texture, transparency, adhesion to the adherend surface, interaction with the drug, and the like. The rubber-based or acrylic-based adhesive may cause problems such as deterioration over time and skin irritation.

On the other hand, a soft resin or gel having an ability to adhere to an adherend surface (hereinafter referred to as self-adhesiveness) even if it does not contain an adhesive is known as an application for adhering to human skin or the like.
For example, Patent Gazette 1 discloses a substance that consists essentially of a sticky polyurethane gel, contains both a polyurethane residue and an acrylate residue, and is suitable for use on the skin. Since these substances have shape stability by themselves, they can be attached to an adherend surface such as skin without having a support such as a non-woven fabric or a film.

Further, Patent Document 2 is characterized in that a higher monoalcohol is used as a tackifier as a part of a polyol and a polyol which are main components having a functional group number of 2.4 to 3 and a molecular weight of 3,000 to 6,000. A composition for a soft resin having an adhesiveness having a rubber hardness of 30 or less and a soft resin are disclosed. Since such a soft resin has self-adhesiveness and shape stability by itself, it can be attached to the skin of a human body or the like without using an adhesive.

On the other hand, as a novel adhesive, it is known that a columnar fiber structure having a fine diameter exhibits adhesive properties. Since the fiber structure has micro-order and nano-order diameters, it has been clarified that it follows the surface irregularities of the adherend and develops adhesive force by van der Waals force. For example, Patent Document 3 discloses an adhesive member using a fibrous columnar structure aggregate composed of carbon nanotubes and having a plurality of diameters.

Japanese Unexamined Patent Publication No. 63-225679 Japanese Patent No. 3914373 Japanese Patent No. 4472785

However, considering the application of sticking to the skin of the human body, there are problems such as resistance to sweating and stuffiness due to sticking for a long time, resistance to deterioration of adhesive strength due to getting wet, and resistance to underwater use (for example, bath and shower). Has not been resolved yet.
That is, the adhesive material disclosed in Patent Documents 1 to 3 is actually attached to the skin for a long period of time, or when the adhesive strength is lowered when the adhesive material is attached to the skin and a shower or a bath is taken. There is still room for improvement when using it.

In addition, there has been a demand for affixing to an adherend surface having an extremely high water content, such as a curing tape on a concrete surface that has just been placed. That is, since the concrete surface that has just been placed has a high water content and is constantly dehydrated, it is difficult to firmly adhere and fix the conventional adhesive tape. Therefore, there is a demand for the development of an adhesive tape or the like that can be attached to an adherend surface having an extremely high water content.

In view of the above circumstances, it is an object of the present invention to provide a molded product that exhibits excellent adhesive strength not only in the air but also on a wet surface and in water, and an adhesive material using the molded product. ..

As a result of diligent studies, the present inventors have a fiber structure having a number density of 10 ³ to 10 ¹¹ lines / mm ² and having columnar structure fibers oriented in the length direction, a thermoplastic resin, and a thermosetting resin. , And a resin layer containing one or more resins selected from the group consisting of photocurable resins, and a molded product containing the above-mentioned problems were found to be able to solve the above problems, and the present invention was completed.

That is, the present invention is as follows.
[1]
A fiber structure having a fiber density of 10 ³ to ¹¹ fibers / mm ² and having columnar fibers oriented in the length direction,
A resin layer containing one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins.
Mold containing.
[2]
The molded product according to the above [1], wherein the length of the fiber having a columnar structure oriented in the length direction is 10 μm or more and 1000 μm or less.
[3]
The fiber structure is formed of a resin composition containing at least one resin selected from the group consisting of a thermoplastic resin having a tensile elastic modulus of 200 MPa or more, a thermosetting resin, and a photocurable resin. The molded product according to the above [1] or [2].
[4]
The molded product [5] according to the above [1] or [2], wherein the fiber structure has fibers formed from carbon nanotubes.
The molded product according to any one of [1] to [4] above, wherein the hardness (shore A) of the resin contained in the resin layer is 80 or less.
[6]
The molded product according to any one of [1] to [5] above, wherein the thickness of the resin layer is 0 μm or more and 200 μm or less with respect to the length of the fiber having a columnar structure oriented in the length direction.
[7]
The molded product according to any one of [1] to [6] above, wherein the adhesive force to glass in the air is 5 N / cm ² or more, and the adhesive force to glass in water is 5 N / cm ² or more. ..
[8]
An adhesive material containing the molded product according to any one of the above [1] to [7].

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a molded product that exhibits excellent adhesive strength not only in the air but also on a wet surface and in water, and an adhesive material using the molded product.

The schematic cross-sectional view of the molded article in this embodiment is shown.

Hereinafter, a mode for carrying out the present invention (hereinafter, also referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the present embodiment, and can be variously modified and implemented within the scope of the gist thereof.

The molded body of this embodiment is
A fiber structure having a fiber density of 10 ³ to ¹¹ fibers / mm ² and having columnar fibers oriented in the length direction,
Includes a resin layer containing one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins.

FIG. 1 shows a schematic cross-sectional view of the molded body 10 in the present embodiment. The molded body 10 includes at least a fiber structure 2 and a resin layer 1. The fibers 2a contained in the fiber structure are oriented in the length direction L, and the fibers 2a of the fiber structure are fixed to the resin layer 1. The fibers are preferably oriented substantially perpendicular to the resin layer. 3 indicates an adhesive surface.

As shown in FIG. 1, the term "fiber structure" as used herein means not only a structure containing columnar fibers 2a and 2b made of the same material as the fibers, but also the columnar fibers. When directly fixed to the resin layer, the fiber structure shows only columnar fibers.

[Fiber structure]
The molded product of the present embodiment has a fiber structure having a number density of 10 ³ to 10 ¹¹ fibers / mm ² and having columnar structure fibers oriented in the length direction (hereinafter, also simply referred to as “fibers”). Including.

The density of the columnar fibers oriented in the length direction is 10 ³ to 10 ¹¹ fibers / mm ² , preferably 10 ⁴ to ¹⁰ 10 fibers / mm ² , and more preferably 10 ⁵ to 10 ⁹ fibers / mm ^2. It is mm ² , and more preferably 10 ⁶ to ⁸ pieces / mm ² . If the number density is less than 10 ³ lines / mm ² , the adhesive strength of the molded product becomes insufficient, and if it exceeds 10 ¹¹ lines / mm ² , the resin is hard to infiltrate and it becomes difficult to form a resin layer.
Here, the fiber number density can be measured according to the method described in the examples.

The cross section of the fiber shape may have any suitable shape, and examples thereof include a substantially circular shape, an elliptical shape, and an n-side polygon (n is an integer of 3 or more). Further, the fiber may be hollow or may be a filling material.

The length of the fiber is not particularly limited, but is preferably 10 μm or more and 1000 μm or less, more preferably 20 μm or more and 700 μm or less, and further preferably 20 μm or more and 500 μm or less. When the length of the fiber is 10 μm or more, the adhesive strength tends to be further improved, and when the fiber length is 1000 μm or less, the adhesive state tends to be easily maintained.
Here, the fiber length can be measured according to the method described in the examples.

The material of the fiber structure is not particularly limited, and for example, metals such as aluminum and iron; inorganic materials such as silicon; carbon materials such as carbon nanofibers and carbon nanotubes; general-purpose plastics, engineering plastics, super engineering plastics and the like. Resin; etc. Specific examples of the resin include polystyrene, polyimide, polyethylene, polypropylene, polybutadiene, polyethylene terephthalate, acetyl cellulose, polycarbonate, polyamide and the like. As for various physical properties such as the molecular weight of the resin, any appropriate physical property can be adopted as long as the problem of the present invention can be solved.

In the present embodiment, the fiber structure having columnar structures oriented in the length direction includes one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins. It is formed from a resin composition, and the tensile elastic modulus of these resins is preferably 200 MPa or more. When the tensile elastic modulus of the resin forming the fiber structure is 200 MPa or more, the structure of the fiber structure can be maintained even after bonding, and the bonded state tends to be easily maintained.
Here, the tensile elastic modulus of the resin can be measured according to the method described in the examples.

Examples of the thermoplastic resin forming the fiber structure include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polymethylmethacrylate, polystyrene, styrene-acrylonitrile copolymer, polybutadiene, polycarbonate, polyamide, polyacetal, and polyimide. From the viewpoint of adhesive strength, polyethylene, polystyrene, styrene-acrylonitrile copolymer, polycarbonate and polybutadiene are preferable, and polystyrene and styrene-acrylonitrile copolymer are more preferable.
Examples of the thermosetting resin forming the fiber structure include phenol resin, melamine resin, epoxy resin, polyurethane, silicone resin and the like.
Examples of the photocurable resin forming the fiber structure include acrylate resin, epoxy acrylate resin, urethane acrylate resin, and ester acrylate resin. From the viewpoint of adhesive strength, acrylate resin and urethane resin are preferable. It is an acrylate resin, more preferably an acrylate resin.

Further, from the viewpoint of imparting conductivity, the fiber structure preferably has fibers made of carbon nanotubes.

Further, the resin composition forming the fiber structure may contain other components other than the above-mentioned resin. Examples of other components include antioxidants, light stabilizers, inorganic fillers, flame retardants, carbon-based fillers, metal-based fillers, and the like.

[Resin layer]
The molded product of the present embodiment is one or more resins selected from the group consisting of a fiber structure having columnar fibers oriented in the length direction, a thermoplastic resin, a thermosetting resin, and a photocurable resin. It has at least a resin layer containing. That is, as shown in FIG. 1 described above, the molded body includes a resin layer and a fiber structure, and the fiber structure is fixed to the resin layer.

The resin forming the resin layer of the present embodiment preferably has a hardness (shore A) of 80 or less. When the hardness (shore A) of the resin forming the resin layer is 80 or less, the adhesive force in water tends to increase. The hardness (shore A) of the resin is more preferably 60 or less, still more preferably 50 or less.
Here, the hardness (share A) of the resin can be measured according to the method described in the examples.

The resin layer contains one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins. Here, the thermoplastic resin, the thermosetting resin, and the photocurable resin are not particularly limited, and examples thereof include the same resins listed as the resins for forming the fiber structure described above. Among them, from the viewpoint of impregnating the fiber structure with the resin, thermoplastic polyurethane, photocurable acrylic resin, thermosetting silicone elastomer and the like are preferable, and photocurable acrylic resin and thermosetting silicone elastomer are more preferable, and thermosetting is thermosetting. Sexic silicone elastomers are more preferred.

Further, the resin layer may contain other components other than the resin, and the other components are, for example, the same as the other components contained in the resin composition forming the fiber structure described above. Can be mentioned.

The thickness of the resin layer is preferably 0 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and 25 μm or more and 120 μm or less with respect to the length of the fiber having a columnar structure oriented in the length direction. Is even more preferable.
When the thickness of the resin layer is 0 μm or more and 200 μm or less with respect to the length of the columnar structure fibers oriented in the length direction, the adhesive force tends to increase.
Here, the thickness of the resin layer can be measured according to the method described in the examples.

[Molded product]
In the molded product of the present embodiment, the above-mentioned columnar structure fibers oriented in the length direction are fixed to the resin layer in a specific density range, and as compared with the conventional molded product, only in the atmosphere. However, it exhibits excellent adhesive strength even on wet surfaces and underwater use.

In order to make the adhesive force of the molded product of the present embodiment more sufficient in the air and water, the adhesive force to the glass in the air is 5 N / cm ² or more, and the adhesive force to the glass in water is 5 N / cm ² . The adhesive strength is preferably 5 N / cm ² or more. The adhesive force to glass in the atmosphere is more preferably 10 N / cm ² or more, and further preferably 15 N / cm ² or more. Further, the adhesive force to the glass in water is more preferably 8 N / cm ² or more, and further preferably 10 N / cm ² or more.
Here, the adhesive force to the glass in air and water can be measured according to the method described in the examples.

[Adhesive member]
Since the molded product of the present embodiment has excellent adhesive strength in air and water, it can be particularly preferably used as an adhesive member. The pressure-sensitive adhesive member of the present embodiment is preferably a molded product including the fiber structure and the resin layer of the present embodiment, further provided with a base material. Specific examples of the adhesive member include an adhesive sheet and an adhesive film.

Examples of the base material of the adhesive member include quartz glass, silicon (silicon wafer, etc.), engineering plastic, super engineering plastic, and the like. Specific examples of engineering plastics and super engineering plastics include polyimide, polyethylene, polyethylene terephthalate, acetyl cellulose, polycarbonate, polypropylene, and polyamide. As for various physical properties such as molecular weight, any appropriate physical property can be adopted as long as the object of the present invention can be achieved.

The thickness of the base material can be set to any suitable value depending on the purpose. For example, in the case of a silicon substrate, it is preferably 100 to 10000 μm, more preferably 100 to 5000 μm, and further preferably 100 to 2000 μm. For example, in the case of a polypropylene substrate, it is preferably 1 to 1000 μm, more preferably 1 to 500 μm, and further preferably 5 to 100 μm.

The surface of the substrate is chemically treated with conventional surface treatments such as chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, etc. in order to improve adhesion and retention with adjacent layers. Alternatively, a physical treatment or a coating treatment with an undercoating agent (for example, the above-mentioned adhesive substance) may be applied.

The base material may be a single layer or a multilayer body.

When the molded product of the present embodiment is fixed to the base material, any suitable method can be adopted as the method. For example, the resin layer used for manufacturing the molded product may be used as it is as a base material. Further, an adhesive layer may be provided on the base material and fixed. Further, when the base material is a thermosetting resin, a thin film may be prepared in a state before the reaction, one end of the fiber may be pressure-bonded to the thin film layer, and then a curing treatment may be performed to fix the fiber. When the base material is a thermoplastic resin, metal, or the like, one end of the molded product may be crimped in a molten state, and then cooled to room temperature to be fixed.

[Manufacturing method of molded product]
Any suitable method can be adopted as the method for producing the molded product of the present embodiment. When the fibers contained in the molded product of the present embodiment are formed from the resin composition, a transfer method or the like for transferring this structure can be used by using a mold having an inverted structure corresponding to the columnar structure of the fibers. Specifically, a method of transferring a fine concavo-convex structure to a thermoplastic, thermosetting or photocurable resin using a mold such as anodized alumina can be used.

As a specific method, for example, the mold and the transparent base material are opposed to each other, and the resin composition is filled and arranged between them. At this time, the surface of the mold on which the fine concavo-convex structure is formed, that is, the surface of the mold is made to face the transparent base material. Then, the filled resin composition is irradiated with active energy rays (heat rays such as visible light, ultraviolet rays, electron rays, plasma, infrared rays, etc.) through a transparent base material by, for example, a high-pressure mercury lamp or a metal halide lamp, or heated. The resin composition is cured, and then the mold is peeled off or dissolved. At this time, if necessary, the active energy rays may be irradiated or heated again after peeling or melting.

Alternatively, a solid uncured resin composition is coated on a transparent base material, a roll-shaped mold is pressed against the resin composition to transfer the fine concavo-convex structure, and then the uncured resin composition is transferred. A fiber structure having fibers having a columnar structure can also be obtained by a method of curing the resin composition by irradiating the resin composition with active energy rays or heating it.

The order of the curing reaction of the resin composition and the peeling of the mold may be any order as long as the fine concavo-convex structure can be transferred as a result. For example, the mold is peeled after the resin composition is completely cured. A method of peeling the mold at a stage where the resin composition is cured to some extent and a method of further curing may be selected and used.

When filling and arranging the resin composition between the mold and the transparent base material, a method of applying the resin composition to the transparent base material or the mold by, for example, a roller coating method, a bar coating method, an air knife coating method, or the like. Can be mentioned. At that time, a thickener, a solvent, or the like may be added or the temperature of the resin composition may be adjusted so that the resin composition has an appropriate viscosity.

The material of the transparent base material is not particularly limited, and examples thereof include inorganic materials such as glass, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polymethacrylate resins, polycarbonate resins, vinyl chloride resins, ABS resins, and styrene resins. ..

Next, the molded product of the present embodiment can be obtained by peeling off the transparent base material from the obtained fiber structure and then laminating a resin layer on one side of the fiber structure. The method for laminating the resin layer is not particularly limited, and for example, a method such as spin coating, slit coating, blade coating, or press molding can be used.

Further, as a method for producing a molded product when carbon nanotubes are used as the fibers of the present embodiment, for example, the method described in Patent No. 447278 can be adopted.

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. The methods for measuring and evaluating various physical properties in Examples and Comparative Examples are as follows.

(Evaluation of adhesive strength)
The prepared molded product was fixed to a styrene square case with a double-sided adhesive tape, and the adhesive strength in air and water was measured using a tensile tester (digital force gauge, MX2-500N, IMADA). At this time, a 10φ glass plate washed by ultraviolet ozone treatment was used as the adhesive indenter, the indenter was brought close to the indenter at a speed of 30 mm / min, stopped when a force of 5 N was applied, and compressed for 50 seconds. After that, the absolute value of the minimum value when pulled at 10 mm / min was defined as the adhesive force (N), and the adhesive force per unit area (N / cm ² ) was calculated by dividing by the cross-sectional area. Pure water was used for the test in water, and after adding pure water until the molded product was immersed, evaluation was performed under the same conditions as in the atmosphere.

(Measurement of fiber length and resin layer thickness)
The prepared molded body was cut by hand, and the cross section thereof was observed with a field emission scanning electron microscope (JSM-7800F, JEOL Ltd.) to measure the length of the fiber and the thickness of the resin layer.

(Density of number of fibers)
The density of the number of fibers was measured by observing the surface of the molded body before introducing the resin layer with a field emission scanning electron microscope.

(Tensile modulus)
The tensile modulus was measured under the condition of 23 ° C. according to JIS K 7161.

(Share A hardness)
The Shore A hardness of the resin layer alone was measured under the condition of 23 ° C. according to JIS K 6253.

[Example 1]
Polystyrene (tensile elastic modulus 3000 MPa, JISK7161) was dissolved in chloroform to prepare a 100 g / L solution. 1.2 mL of the prepared chloroform solution was applied onto a 4 cm square glass substrate and dried to prepare a polystyrene thin film. Then, 50 μm thick anodized alumina having pores of 200 nm was placed on a polystyrene thin film, and heat pressing was performed at 180 ° C. for 7 minutes at a pressure of 5 MPa. After the hot pressing, the anodic oxide alumina was dissolved by immersing it in a 1 M aqueous sodium hydroxide solution for 1 hour to prepare a polystyrene fiber structure. After peeling the produced fiber structure from the glass substrate and adhering it to one side of the double-sided adhesive tape, a thermosetting silicone elastomer (thermosetting Shore A hardness 43) is applied to the fiber structure and spun at 5000 rpm for 1 minute. Coated (spin coater: 1HD7, MIKASA SPINCOATER). After spin coating, the silicone elastomer was thermally crosslinked at 70 ° C. for 12 hours to prepare a film-shaped molded product 1.
Result of adhesion was measured, 10 N / cm ² in the atmosphere, in water was 10 N / cm ^2. At this time, the length of the fiber was 35 μm, and the thickness of the resin layer-the length of the fiber was 1 μm.
Table 1 shows various physical properties and evaluation results of the molded product.

[Example 2]
A film-shaped molded product 2 was produced in the same manner as in Example 1 except that the rotation speed of the spin coat was adjusted.
Result of adhesion was measured, 12N / cm ² in the atmosphere, in water was 11N / cm ^2. At this time, the length of the fiber was 30 μm, and the thickness of the resin layer-the length of the fiber was 24 μm.

[Example 3]
A film-shaped molded product 3 was produced in the same manner as in Example 1 except that the rotation speed of the spin coat was adjusted.
Result of adhesion was measured, in the atmosphere 16N / cm ^2, in water was 11N / cm ^2. At this time, the length of the fiber was 53 μm, and the thickness of the resin layer-the length of the fiber was 59 μm.

[Example 4]
A film-shaped molded product 4 was produced in the same manner as in Example 1 except that the rotation speed of the spin coat was adjusted.
Result of adhesion was measured, in the atmosphere 10 N / cm ^2, in water was 8N / cm ^2. At this time, the length of the fiber was 21 μm, and the thickness of the resin layer-the length of the fiber was 90 μm.

[Example 5]
A film-shaped molded product 5 was produced in the same manner as in Example 1 except that the rotation speed of the spin coat was adjusted.
Result of adhesion was measured, 5N / cm ² in the atmosphere, in water was 5N / cm ^2. At this time, the length of the fiber was 17 μm, and the thickness of the resin layer-the length of the fiber was 133 μm.

[Comparative Example 1]
A film-shaped molded product 6 was produced in the same manner as in Example 1 except that the resin layer was not formed.
Result of adhesion was measured, in the atmosphere 0N / cm ^2, in water under was 0N / cm ^2.

[Comparative Example 2]
A film-shaped molded product 7 made of a thermosetting silicone elastomer having a thickness of 1500 μm was produced without using a fiber structure.
Result of adhesion was measured, 4N / cm ² in the atmosphere, in water under was 2N / cm ^2.

As shown in the above table, the molded articles of Examples 1 to 5 exhibited excellent adhesive strength not only in the air but also in water.

The present invention has industrial applicability as a molded product that exhibits excellent adhesive strength not only in the air but also on a wet surface and in water, and as an adhesive material using the molded product.

Claims (8)

A fiber structure having a fiber density of 10 ³ to ¹¹ fibers / mm ² and having columnar fibers oriented in the length direction,
A resin layer containing one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins.
Mold containing. The molded product according to claim 1, wherein the length of the fiber having a columnar structure oriented in the length direction is 10 μm or more and 1000 μm or less. The fiber structure is formed of a resin composition containing at least one resin selected from the group consisting of a thermoplastic resin having a tensile elastic modulus of 200 MPa or more, a thermosetting resin, and a photocurable resin. The molded product according to claim 1 or 2. The molded product according to claim 1 or 2, wherein the fiber structure has fibers formed from carbon nanotubes. The molded product according to any one of claims 1 to 4, wherein the hardness (shore A) of the resin contained in the resin layer is 80 or less. The molded product according to any one of claims 1 to 5, wherein the thickness of the resin layer is 0 μm or more and 200 μm or less with respect to the length of the fiber having a columnar structure oriented in the length direction. The molded product according to any one of claims 1 to 6, wherein the adhesive force to glass in the atmosphere is 5 N / cm ² or more, and the adhesive force to glass in water is 5 N / cm ² or more. An adhesive material comprising the molded product according to any one of claims 1 to 7.

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