Ventilation member and member supply assembly

Abstract

This ventilation member comprises: a porous film comprising a fluorine-free thermoplastic resin as a main component; and an adhesive layer bonded to the porous film. In the adhesive layer, the content ratio of a specific component having an HSP value for which the absolute value of the difference from the HSP value of the thermoplastic resin is 8.5 MPa0.5 or less is less than 0.1 wt%. The member supply assembly comprises: a ventilation member disposed on a face of a target, the face having an opening; and a base material sheet having the ventilation member disposed on a surface thereof. The porous film has a shape such that the film covers the opening when disposed on the face.

Description

Ventilation member and member supply assembly

[0001] The present invention relates to a ventilation member and a member supply assembly.

[0002] Porous films made of fluororesin are used in a variety of applications, including filters, sound-transmitting membranes, ventilation membranes, and diaphragms. For these applications, porous films that do not contain fluorine have also been proposed.

[0003] For example, Patent Document 1 discloses an olefin resin microporous biaxially oriented film having micropores and containing an olefin resin, wherein the puncture strength is 0.7 N or higher and the air permeability is 75 to 400 s / 100 mL.

[0004] Japanese Patent Publication No. 2017-095576

[0005] Porous films used to ensure ventilation through openings in device housings and the like while preventing the passage of foreign matter are sometimes provided as ventilation members to which an adhesive layer is bonded. According to the inventors' research, ventilation members comprising a fluorine-free porous film and an adhesive layer bonded to the porous film may experience a decrease in breathability after prolonged use, indicating room for improvement.

[0006] Therefore, the present invention aims to provide a ventilation member and a member supply assembly suitable for suppressing a decrease in breathability.

[0007] The present invention comprises a porous film mainly composed of a fluorine-free thermoplastic resin, and an adhesive layer bonded to the porous film, wherein the difference between the HSP value of the adhesive layer and the HSP value of the thermoplastic resin is 8.5 MPa in absolute value. 0.5 The present invention provides a breathable member in which the content of a specific component having the following HSP value is less than 0.1% by weight.

[0008] In another aspect, the present invention provides a member supply assembly including a ventilation member disposed on the surface of an object having a surface with an opening, and a base material sheet on which the ventilation member is disposed, wherein the ventilation member is the ventilation member of the present invention, and the porous film has a shape that covers the opening when disposed on the surface.

[0009] According to the present invention, it is possible to provide a ventilation member and a member supply assembly suitable for suppressing a decrease in air permeability.

[0010] FIG. 1 is a cross-sectional view schematically showing an example of the ventilation member of the present invention. FIG. 2 is a cross-sectional view schematically showing Modification 1 of the ventilation member. FIG. 3 is a cross-sectional view schematically showing an example of the porous film. FIG. 4 is a cross-sectional view schematically showing an example of the film member. FIG. 5 is a cross-sectional view schematically showing Modification 2 of the ventilation member. FIG. 6 is a cross-sectional view schematically showing Modification 3 of the ventilation member. FIG. 7 is a cross-sectional view schematically showing Modification 4 of the ventilation member. FIG. 8 is a cross-sectional view schematically showing Modification 5 of the ventilation member. FIG. 9 is a cross-sectional view schematically showing an example of the member supply assembly of the present invention. FIG. 10 is a cross-sectional view schematically showing Modification 1 of the member supply assembly. FIG. 11 is a cross-sectional view schematically showing Modification 2 of the member supply assembly. FIG. 12 is a cross-sectional view schematically showing a sample body for evaluating the air permeability of the porous film using a measuring jig. FIG. 13 is a diagram explaining the change over time of the porous film when a durability test is performed on a conventional ventilation member. FIG. 14A is a diagram showing the result of observing region A in the cross-section of the ventilation member of Example 1 after 500 hours from the start of the durability test by SEM. FIG. 14B is a diagram showing the result of observing region B in the cross-section of the ventilation member of Example 1 after 500 hours from the start of the durability test by SEM. FIG. 15A is a diagram showing the result of observing region A in the cross-section of the ventilation member of Comparative Example 1 after 500 hours from the start of the durability test by SEM. FIG. 15B is a diagram showing the result of observing region B in the cross-section of the ventilation member of Comparative Example 1 after 500 hours from the start of the durability test by SEM.

[0011] The ventilation member according to the first aspect of the present invention includes a porous film containing a fluorine-free thermoplastic resin as a main component, and an adhesive layer bonded to the porous film, and the difference between the HSP value of the thermoplastic resin in the adhesive layer is 8.5 MPa in absolute value. 0.5 The content ratio of a specific component having the following HSP value is less than 0.1% by weight.

[0012] In the second aspect of the present invention, for example, in the ventilation member according to the first aspect, the adhesive layer contains at least one selected from the group consisting of terpene-based tackifiers and acrylic oligomers.

[0013] In the third aspect of the present invention, for example, in the ventilation member according to the first or second aspect, the adhesive layer includes a first adhesive layer bonded to the first main surface of the porous film and a second adhesive layer bonded to the second main surface of the porous film.

[0014] In the fourth aspect of the present invention, for example, in the ventilation member according to any one of the first to third aspects, the porous film has a ventilation region to which the adhesive layer is not bonded, and the area of the ventilation region is 40 mm 2 or less.

[0015] In the fifth aspect of the present invention, for example, in the ventilation member according to any one of the first to fourth aspects, the thermoplastic resin includes at least one selected from the group consisting of polyolefin resins, polyester resins, and polyimide resins.

[0016] In the sixth aspect of the present invention, for example, in the ventilation member according to any one of the first to fifth aspects, the thermoplastic resin includes at least one selected from the group consisting of polyolefin resins and polyester resins.

[0017] In the seventh aspect of the present invention, for example, in the ventilation member according to any one of the first to sixth aspects, the thermoplastic resin includes a polyolefin resin.

[0018] In the eighth aspect of the present invention, for example, in the ventilation member according to any one of the first to seventh aspects, the porous film is a stretched film.

[0019] In the ninth aspect of the present invention, for example, the ventilation member according to any one of the first to eighth aspects further comprises a ventilation support material laminated on the porous film.

[0020] A component supply assembly according to a tenth aspect of the present invention comprises a ventilation member disposed on the surface of an object having an opening, and a base sheet on which the ventilation member is disposed, wherein the ventilation member is a ventilation member according to any one of the first to ninth aspects, and the porous film has a shape that covers the opening when disposed on the surface.

[0021] Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiments.

[0022] [Ventilation Member] An example of the ventilation member of the present invention is shown in Figure 1. The ventilation member 4 (4A) in Figure 1 comprises a porous film 1 mainly composed of a thermoplastic resin that does not contain fluorine, and an adhesive layer 5 bonded to the porous film 1.

[0023] In this specification, "adhesive" means "adhesion" or "bonding." For example, "adhesive layer" means "adhesion layer" or "bonding layer."

[0024] In this specification, "pressure-sensitive adhesive" refers to a type of adhesion as defined in JIS (Japanese Industrial Standards), specifically a temporary adhesive that can bond with only slight pressure. It also possesses cohesive force and elasticity, meaning it can bond strongly while also being able to be peeled from hard, smooth surfaces. The adhesive is a soft solid and does not change state like a conventional adhesive. Because the adhesive wets the substrate and resists peeling, it can instantly exert practical adhesive strength when substrates are joined together. In other words, the adhesive combines the properties of a liquid (fluidity) to wet the substrate and the properties of a solid (cohesive force) to resist peeling. Since the adhesive is a soft solid, applying pressure or allowing time to pass gradually increases the contact area with the substrate. Because it can maintain this softness for a long time, it has the property of being removable when desired.

[0025] In this specification, "adhesive" refers to the property of bonding and integrating surfaces of the same or different types of solids, as defined in JIS (Japanese Industrial Standards). When bonding adherends together, adhesives are fluid substances that wet and conform to the adherends. Subsequently, they change into a solid through heating or chemical reactions, forming a strong bond at the interface between the adherends and exhibiting resistance to peeling. In other words, adhesives wet with a fluid substance and bond as a solid.

[0026] The ventilation member 4 (4A) in Figure 1 comprises a porous film 1, which has breathability in the thickness direction and prevents the passage of foreign matter in that direction. The ventilation member 4 is, for example, placed on the surface of an object having an opening, and is a member that ensures ventilation through the opening while preventing the passage of foreign matter through the opening. In this case, the ventilation member 4 is usually placed such that the porous film 1 covers the opening of the object.

[0027] The ventilation member 4 (4A) comprises an adhesive layer 5 positioned on one of the main surfaces of the porous film 1. The porous film 1 and the adhesive layer 5 are directly joined. The ventilation member 4A can be positioned on the surface of an object via the adhesive layer 5. In the example shown in Figure 1, the adhesive layer 5 is joined to the first main surface 1a of the porous film 1. However, the adhesive layer 5 may also be joined to the second main surface 1b of the porous film 1.

[0028] A modified example of the ventilation member 4 of this embodiment is shown in Figure 2. The ventilation member 4 (4B) in Figure 2 has the same configuration as the ventilation member 4A in Figure 1, except that it further comprises an adhesive layer 5 (5B) located on the other main surface side of the porous film 1. The porous film 1 is sandwiched between the pair of adhesive layers 5 (5A, 5B).

[0029] As shown in Figure 2, the adhesive layer 5 may include a first adhesive layer 5A bonded to the first main surface 1a of the porous film 1 and a second adhesive layer 5B bonded to the second main surface 1b of the porous film 1.

[0030] In this embodiment, the air permeability A is expressed as the Gurley number of the porous film 1 72 hours after the start of the durability test in an atmosphere of 65°C and 95% RH. 72 The air permeability is defined as the Gurley number of porous film 1 500 hours after the start of the above durability test, and air permeability A is expressed in this way. 500 This is defined as follows. In this case, the ventilation member 4 is {(Air permeability A 500 - Air permeability A 72 ) / Air permeability A 72 The rate of decrease in air permeability R, expressed as} × 100, can be 5% or less. A ventilation member 4 in which the rate of decrease in air permeability R is kept to 5% or less is suitable for suppressing a decrease in air permeability.

[0031] The upper limit of the air permeability reduction rate R may be 4.5% or less, and may also be 4% or less.

[0032] In this specification, "Gurley number" refers to the air permeability resistance (air permeability expressed in Gurley number) measured in accordance with the Wang Ken method of testing as defined in JIS P8117:2009. As the Wang Ken method testing machine, for example, a digital Wang Ken air permeability tester manufactured by Asahi Seiko Co., Ltd. can be used.

[0033] Even if the size of porous film 1 is less than the recommended dimensions (50 mm x 50 mm) for the test specimen of the Wang Ken testing machine method, it is possible to evaluate the air permeability resistance (air permeability expressed in Gurley numbers) in accordance with the Wang Ken testing machine method by using a measuring jig.

[0034] Figure 12 is a schematic cross-sectional view showing a sample body for evaluating the air permeability of the porous film 1 using a measuring jig. The sample body in Figure 12 includes the air permeability member 4 (4B) shown in Figure 2. In this embodiment, as shown in Figure 12, the air permeability of the porous film 1 is evaluated with respect to the air permeability member 4 (4B) shown in Figure 2.

[0035] The measuring jig has a shape and size that can be placed in the air permeability measuring section of the Ono testing machine, and has a thickness and material that do not deform under the differential pressure applied to the test piece during the measurement of air permeability resistance. An example of the measuring jig is a disc 51 made of SUS (stainless steel) with a thickness of 2 mm and a diameter of 47 mm. A through-hole having an opening 51a with a size smaller than the film to be evaluated is provided at the center in the plane of the measuring jig. The cross-section of the through-hole is typically circular, and the diameter is such that the opening 51a of the through-hole is completely covered by the film to be evaluated. The diameter of the through-hole is 1 mm. Next, the ventilation member 4 is fixed to one surface of the measuring jig so that the porous film 1 to be evaluated covers the opening 51a. The fixing is such that only the opening 51a and the effective test section of the porous film 1 to be evaluated (the portion overlapping the opening 51a when viewed from a direction perpendicular to the main surface of the porous film 1) allow air to pass through during the measurement of air permeability resistance, and the fixing portion does not impede the passage of air in the effective test section of the porous film 1. For fixing the ventilation member 4, an adhesive layer 5 is used. As the adhesive layer 5, for example, a double-sided adhesive tape with a ventilation hole having a shape matching the shape of the opening punched at the center can be used. The double-sided adhesive tape has, for example, an annular shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm. The double-sided adhesive tape may be arranged between the measuring jig and the porous film 1 so that the circumference of the ventilation hole and the circumference of the opening 51a coincide. Next, the measuring jig with the ventilation member 4 fixed is set in the air permeability measuring section of the Ono testing machine so that the fixed surface of the porous film 1 is on the downstream side of the air flow during the measurement, and a test is carried out by the Ono testing machine method, and the air permeability resistance indication value t shown by the testing machine is recorded. Next, the recorded air permeability resistance indication value t is converted by the formula t 2 = {t × (area of the effective test section of the porous film 1 [cm K ) / 6.452 [cm K ), and the obtained converted value t 2 is obtained 2 KThis can be expressed as the air permeability, represented by the Gurley number of the porous film 1 measured in accordance with the Wang-Lan testing machine method. It has been confirmed that the air permeability resistance measured without using a measuring jig for a porous film 1 that meets the recommended dimensions of the Wang-Lan testing machine method (50 mm x 50 mm) agrees well with the air permeability resistance measured using a measuring jig after the porous film 1 has been cut into small pieces, meaning that the use of a measuring jig does not substantially affect the measured value of air permeability resistance.

[0036] The durability test can be performed by placing the sample shown in Figure 12 in a constant temperature and humidity chamber set to a furnace temperature of 65°C and relative humidity of 95 RH%. For example, a constant temperature and humidity chamber manufactured by Espec can be used. 72 hours after the start of the durability test, the air permeability A of the porous film 1 is measured using the method described above. 72 The air permeability A of the porous film 1 is evaluated 500 hours after the start of the durability test using the method described above. 500 Evaluate.

[0037] The air permeability A0 of the porous film 1 in its initial state before the start of the above durability test, expressed by the Gurley number, is, for example, 500 seconds / 100 mL or less. The upper limit of air permeability A0 may be 400 seconds / 100 mL or less, 300 seconds / 100 mL or less, 200 seconds / 100 mL or less, 150 seconds / 100 mL or less, and even 110 seconds / 100 mL or less. The lower limit of air permeability A0 is, for example, 0.1 seconds / 100 mL or more. The lower limit of air permeability A0 may be 1 second / 100 mL or more, 5 seconds / 100 mL or more, 10 seconds / 100 mL or more, and even 15 seconds / 100 mL or more.

[0038] Air permeability A, expressed by the Gurley number of porous film 1. 72 For example, it is 500 seconds / 100 mL or less. Air permeability A 72 The upper limit may be 400 seconds / 100 mL or less, 300 seconds / 100 mL or less, 200 seconds / 100 mL or less, 150 seconds / 100 mL or less, and even 120 seconds / 100 mL or less. Air permeability A 72 The lower limit is, for example, 0.1 seconds / 100 mL or more. Air permeability A 72The lower limit may be 1 second / 100 mL or more, 5 seconds / 100 mL or more, 10 seconds / 100 mL or more, or even 15 seconds / 100 mL or more.

[0039] Air permeability A, expressed by the Gurley number of porous film 1. 500 For example, it is 500 seconds / 100 mL or less. Air permeability A 500 The upper limit may be 400 seconds / 100 mL or less, 300 seconds / 100 mL or less, 200 seconds / 100 mL or less, 150 seconds / 100 mL or less, and even 120 seconds / 100 mL or less. Air permeability A 500 The lower limit is, for example, 0.1 seconds / 100 mL or more. Air permeability A 500 The lower limit may be 1 second / 100 mL or more, 5 seconds / 100 mL or more, 10 seconds / 100 mL or more, or even 15 seconds / 100 mL or more.

[0040] Figure 13 illustrates the change over time of the porous film 71 when the above durability test is performed on a conventional ventilation member 70. The ventilation member 70 comprises a porous film 71 mainly composed of a thermoplastic resin that does not contain fluorine, and adhesive layers 75 bonded to both main surfaces of the porous film 71. The inventors have discovered a new problem with the conventional ventilation member 70: the air permeability of the porous film 71 decreases after the above durability test. According to the inventors' investigation, in the conventional ventilation member 70, as time passes from the start of the above durability test, a specific component SI contained in the adhesive layer 75 penetrates in the thickness direction of the porous film 71 (Figure 13 (A) to (B)). Furthermore, the specific component SI penetrates in the film surface direction of the porous film 71, for example, after 500 hours (Figure 13 (C)). The decrease in air permeability of the porous film 71 due to the above durability test is thought to be caused by a decrease in the area of ​​the ventilation region (the region corresponding to the effective test area) 711 of the porous film 71. In the example shown in Figure 13, adhesive layers 75 are bonded to both main surfaces of the porous film 71. However, the reduction in the area of ​​the breathable region 711 of the porous film 71 due to the durability test can also occur when the adhesive layer 75 is bonded to only one main surface of the porous film 71.

[0041] In contrast, in the ventilation member 4 of this embodiment, {(Ventilation degree A500 - Air permeability A 72 ) / Air permeability A 72 The rate of decrease in air permeability R, expressed as} × 100, can be 5% or less. This indicates that, in the air permeability member 4 of this embodiment, even after a long period of time has elapsed since the start of the durability test, there is almost no penetration of the specific component SI into the porous film 1.

[0042] In this embodiment, the difference between the HSP value of the specific component SI and the HSP value of the thermoplastic resin is 8.5 MPa in absolute value. 0.5 The following applies: In the breathable member 4 of this embodiment, the adhesive layer 5 substantially does not contain the specific component SI. In other words, the difference between the HSP value of the thermoplastic resin in the adhesive layer 5 and the specific component SI is 8.5 MPa in absolute value. 0.5 The content of specific component SI having the following HSP value is less than 0.1% by weight. If the adhesive layer 5 substantially does not contain specific component SI which has relatively high compatibility with thermoplastic resin, penetration of specific component SI into the porous film 1 is unlikely to occur even after a long time has passed since the start of the durability test. As a result, the decrease in the air permeability of the breathable member 4 is suppressed.

[0043] In this specification, "HSP value" refers to the Hansen solubility parameter (δ). The Hansen solubility parameter (δ) is defined by a three-dimensional parameter (δD, δP, δH) and is expressed by the following equation (1).

[0044] δ 2 = (δD) 2 + (δP) 2 + (δH) 2 ... (1)

[0045] In equation (1), δD represents the London dispersion term, δP represents the polarity term, and δH represents the hydrogen bonding term. The HSP values ​​of the specific component SI and the thermoplastic resin in the ventilation member 4 can be determined, for example, by the Hansen solubility sphere method or the molecular group contribution method. In the Hansen solubility sphere method, affinity evaluation is performed between the target substance and several solvents with known HSP values, and the solvents are divided into good solvents and poor solvents. Next, the HSP values ​​of these solvents are plotted on a three-dimensional graph with δD, δP, and δH as axes. A sphere with the smallest radius (Hansen sphere) is created where the HSP values ​​of the good solvents are inside the sphere and the HSP values ​​of the poor solvents are outside the sphere, and the center of this sphere is calculated as the HSP value of the target substance. In the molecular group contribution method, the structure of each constituent unit in the target substance is input using smiles (simplified molecular input line entry system) notation, and the HSP value for each unit is calculated. In either method, the Hansen Solubility Parameter in Practice (HSPiP) software can be used to calculate the HSP value.

[0046] The lower limit of the difference between the HSP value of a specific component SI and the HSP value of the thermoplastic resin is, for example, 1.0 MPa in absolute value. 0.5 That's all.

[0047] The adhesive comprising the adhesive layer 5 includes, for example, a base polymer, a tackifier, and a crosslinking agent. The specific component SI may be a rosin-based resin that can be used as a tackifier in general. Examples of rosin-based resins include rosin esters. Examples of rosin esters include unmodified rosin esters obtained by esterifying unmodified rosin with alcohols, modified rosin esters obtained by esterifying modified rosin with alcohols, and unsaturated fatty acid modified rosin esters obtained by modifying unmodified rosin esters or modified rosin esters with unsaturated fatty acids.

[0048] Methods for confirming that the content of the specific component SI in the adhesive layer 5 of the breathable member 4 is less than 0.1% by weight include, for example, infrared absorption spectroscopy (IR), nuclear magnetic resonance analysis (NMR), gel permeation chromatography (GPC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The content of the specific component SI in the adhesive layer 5 being less than 0.1% by weight may also be confirmed by MALDI-TOF-MS. The content of the specific component SI in the adhesive layer 5 being less than 0.1% by weight may also be confirmed by two or more methods selected from the above methods.

[0049] In the breathable member 4 of this embodiment, it is preferable that the adhesive layer 5 is substantially free of rosin ester. In other words, it is preferable that the rosin ester content in the adhesive layer 5 is less than 0.1% by weight. For example, the difference between the HSP value of rosin ester and the HSP value of polymethylpentene (PMP) resin is 8.5 MPa in absolute value. 0.5 The following is true: If the adhesive layer 5 substantially does not contain rosin ester, which has relatively high compatibility with thermoplastic resin, penetration of rosin ester into the porous film 1 is unlikely to occur even after a long period of time has elapsed since the start of the durability test. As a result, the decrease in the permeability of the permeable member 4 is suppressed. Examples of rosin ester include those exemplified above.

[0050] Methods for confirming that the rosin ester content in the adhesive layer 5 of the breathable member 4 is less than 0.1% by weight include, for example, infrared absorption spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The fact that the rosin ester content in the adhesive layer 5 is less than 0.1% by weight may also be confirmed by MALDI-TOF-MS. The fact that the rosin ester content in the adhesive layer 5 is less than 0.1% by weight may also be confirmed by two or more methods selected from the above methods.

[0051] The adhesive constituting the adhesive layer 5 can be any suitable adhesive, as long as it does not impair the effects of the present invention. Such an adhesive is preferably at least one selected from the group consisting of acrylic adhesives, urethane adhesives, and silicone adhesives, and is preferably an acrylic adhesive. The adhesive constituting the adhesive layer 5 may also be an acrylic adhesive.

[0052] Below, we will describe acrylic adhesives as a typical example of the adhesives that make up the adhesive layer 5.

[0053] Acrylic adhesives are formed from acrylic adhesive compositions. Acrylic adhesives can thus be defined as being formed from acrylic adhesive compositions. This is because, since acrylic adhesives are formed when acrylic adhesive compositions undergo crosslinking reactions such as heating or ultraviolet irradiation, it is impossible and impractical to directly identify acrylic adhesives by their structure. Therefore, the definition "formed from acrylic adhesive compositions" appropriately identifies acrylic adhesives as a "substance."

[0054] The acrylic adhesive composition preferably comprises an acrylic polymer and a crosslinking agent. The acrylic polymer may be referred to as a so-called base polymer in the field of acrylic adhesives. There may be only one type of acrylic polymer or two or more types.

[0055] The content of acrylic polymer in the acrylic adhesive composition is preferably 60% to 99.9% by weight, more preferably 65% ​​to 99.9% by weight, even more preferably 70% to 99.9% by weight, particularly preferably 75% to 99.9% by weight, and most preferably 80% to 99.9% by weight, based on solid content.

[0056] The weight-average molecular weight (Mw) of the acrylic polymer is preferably 100,000 to 2,500,000, more preferably 200,000 to 2,000,000, even more preferably 300,000 to 1,800,000, and particularly preferably 400,000 to 1,500,000, in order to better exhibit the effects of the present invention.

[0057] As the acrylic polymer, any suitable acrylic polymer can be used as long as it does not impair the effects of the present invention. Preferably, such an acrylic polymer is formed by polymerization from a composition (M) comprising an alkyl (meth)acrylate (component a) having 4 to 12 carbon atoms in the alkyl group of the alkyl ester portion, and at least one (component b) selected from the group consisting of (meth)acrylate esters and (meth)acrylic acid having an OH group. Component a and component b may each be independent of one type or two or more types.

[0058] Examples of alkyl (meth)acrylate esters having 4 to 12 carbon atoms in the alkyl group of the alkyl ester portion include n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Among these, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n-octyl (meth)acrylate are preferred in terms of being able to better express the effects of the present invention, and more preferably n-butyl acrylate and 2-ethylhexyl acrylate.

[0059] Examples of (meth)acrylic acid esters having an OH group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Among these, hydroxyethyl (meth)acrylate and hydroxybutyl (meth)acrylate are preferred, and hydroxyethyl acrylate is preferred, in terms of being able to better express the effects of the present invention.

[0060] As the (meth)acrylic acid, acrylic acid is preferred in that it can better exhibit the effects of the present invention.

[0061] Composition (M) may contain copolymerizable monomers other than components a and b. The copolymerizable monomer may be one type or two or more types. Such copolymerizable monomers include, for example, carboxyl group-containing monomers such as itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and their acid anhydrides (e.g., acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride) (excluding (meth)acrylic acid); amide group-containing monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, and N-hydroxyethyl(meth)acrylamide; amino group-containing monomers such as (meth)acrylate aminoethyl, (meth)acrylate dimethylaminoethyl, and (meth)acrylate t-butylaminoethyl; epoxy group-containing monomers such as (meth)acrylate glycidyl and (meth)acrylate methylglycidyl; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, (meth)acryloylmorpholine, N-vinylpiperidone, N - Heterocyclic monomers such as vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, vinyloxazole; sulfonic acid group-containing monomers such as sodium vinylsulfonate; phosphate group-containing monomers such as 2-hydroxyethylacryloylphosphate; imide group-containing monomers such as cyclohexylmaleimide, isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; cyclopentyl(meth) (meth)acrylic acid esters having alicyclic hydrocarbon groups such as acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; aromatic ring-containing (meth)acrylates such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxybenzyl (meth)acrylate (e.g., m-phenoxybenzyl (meth)acrylate), thiophenoxybenzyl (meth)acrylate, and benzylbenzyl (meth)acrylate;Examples include (meth)acrylate alkoxyalkyl esters such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; olefins and dienes such as ethylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ethers; and vinyl chloride.

[0062] Polyfunctional monomers can also be used as copolymerizable monomers. A polyfunctional monomer is a monomer having two or more ethylenically unsaturated groups in one molecule. Any suitable ethylenically unsaturated group can be used as the ethylenically unsaturated group, as long as it does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radical polymerizable functional groups such as vinyl groups, propenyl groups, isopropenyl groups, vinyl ether groups (vinyloxy groups), and allyl ether groups (allyloxy groups). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, and the like. Such polyfunctional monomers may be present in single-component form or in two or more forms.

[0063] The content of the alkyl (meth)acrylate (component a) in which the alkyl group of the alkyl ester portion has 4 to 12 carbon atoms is preferably 30% by weight or more, more preferably 35% to 99% by weight, even more preferably 40% to 98% by weight, and particularly preferably 50% to 95% by weight, relative to the total amount (100% by weight) of the monomer components constituting the acrylic polymer, in order to better express the effects of the present invention.

[0064] The content of at least one (component b) selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid is preferably 1% by weight or more, more preferably 1% to 30% by weight, even more preferably 2% to 20% by weight, and particularly preferably 3% to 10% by weight, relative to the total amount of monomer components constituting the acrylic polymer (100% by weight), in order to better express the effects of the present invention.

[0065] Composition (M) may contain any other suitable components as long as they do not impair the effects of the present invention. Examples of such other components include polymerization initiators, chain transfer agents, solvents, etc. The content of these other components may be any suitable amount as long as they do not impair the effects of the present invention.

[0066] Depending on the type of polymerization reaction, the polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator (photoinitiator). There may be only one polymerization initiator or two or more.

[0067] Thermal polymerization initiators can preferably be used when obtaining acrylic polymers by solution polymerization. Examples of such thermal polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionic acid)dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, and 2,2'-azobis[2-(5-methyl-2-imidazoline-2-yl)p Azo initiators such as ropanedihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethylene isobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.); persulfates such as potassium persulfate and ammonium persulfate, di(2-ethylhexyl)peroxydicarbonate, Examples include peroxide initiators such as di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butylhydroperoxide, and hydrogen peroxide; redox initiators combining peroxides with reducing agents, such as combinations of persulfates and sodium bisulfite, and combinations of peroxides and sodium ascorbate; substituted ethane initiators such as phenyl-substituted ethane; and aromatic carbonyl compounds.

[0068] Photopolymerization initiators can preferably be used when obtaining acrylic polymers by active energy ray polymerization. Examples of photopolymerization initiators include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.

[0069] Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone. Examples of α-ketol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. An example of an aromatic sulfonyl chloride-based photopolymerization initiator is 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzyl-based photopolymerization initiators include benzyl. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzyldimethylketal. Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0070] The amount of polymerization initiator used can be set to any appropriate amount, as long as it does not impair the effects of the present invention.

[0071] The acrylic adhesive composition may contain a crosslinking agent. By using a crosslinking agent, the cohesive force of the acrylic adhesive can be improved, and the effects of the present invention can be further exhibited. There may be only one type of crosslinking agent, or there may be two or more types.

[0072] Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, silicone-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, silane-based crosslinking agents, alkyl etherified melamine-based crosslinking agents, metal chelate-based crosslinking agents, and peroxides. Preferably, the crosslinking agent is at least one selected from the group consisting of isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and peroxides (component c).

[0073] The isocyanate crosslinking agent can be a compound having two or more isocyanate groups (including isocyanate-regenerating polar groups in which the isocyanate groups are temporarily protected by a blocking agent or quantification, etc.) in one molecule. Examples of isocyanate crosslinking agents include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate.

[0074] Examples of isocyanate crosslinking agents include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; and isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adducts (e.g., Coronate L, manufactured by Tosoh Corporation), trimethylolpropane / hexamethylene diisocyanate trimer adducts (e.g., Coronate HL, manufactured by Tosoh Corporation), and isocyanurate derivatives of hexamethylene diisocyanate (e.g., Coronate HX, manufactured by Tosoh Corporation). Examples include: trimethylolpropane adducts of xylylene diisocyanate (e.g., Takenate D110N, manufactured by Mitsui Chemicals), trimethylolpropane adducts of xylylene diisocyanate (e.g., Takenate D120N, manufactured by Mitsui Chemicals), trimethylolpropane adducts of isophorone diisocyanate (e.g., Takenate D140N, manufactured by Mitsui Chemicals), trimethylolpropane adducts of hexamethylene diisocyanate (e.g., Takenate D160N, manufactured by Mitsui Chemicals), trimethylolpropane adducts of tolylene diisocyanate (e.g., Takenate D101E, manufactured by Mitsui Chemicals); polyether polyisocyanates, polyester polyisocyanates, and adducts thereof with various polyols; and polyfunctionalized polyisocyanates with isocyanurate bonds, biuret bonds, allophanate bonds, etc. Among these, aromatic isocyanates and alicyclic isocyanates are preferred because they can achieve a good balance between deformability and cohesiveness.

[0075] As epoxy crosslinking agents, polyfunctional epoxy compounds having two or more epoxy groups in one molecule can be used. Examples of epoxy crosslinking agents include N,N,N',N'-tetraglycidyl-m-xylenediline, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and sorbitol polyglycidyl ether. Examples of epoxy crosslinking agents include tel, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate ester, diglycidyl o-phthalate ester, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of commercially available epoxy crosslinking agents include "Tetrad C" and "Tetrad X" manufactured by Mitsubishi Gas Chemical Company.

[0076] Examples of peroxides include dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, di-t-butyl peroxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy Examples include neodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, t-butyl peroxyisobutyrate, 1,1-di(t-hexyl peroxy)cyclohexane, 1,1-di(t-butyl peroxy)cyclohexane, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyisopropyl carbonate, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxy-2-hexanoate, t-butyl peroxypivalate, and t-hexyl peroxypivalate. Examples of commercially available peroxides include the "Nipper BMT" series and the "Nipper BW" series manufactured by Nippon Oil & Fats Co., Ltd.

[0077] The amount of crosslinking agent in the acrylic adhesive composition can be any appropriate amount, as long as it does not impair the effects of the present invention. For example, in order to better express the effects of the present invention, the amount is preferably 0.01 to 20 parts by weight, more preferably 0.01 to 18 parts by weight, even more preferably 0.01 to 15 parts by weight, and particularly preferably 0.05 to 10 parts by weight, relative to the solid content (100 parts by weight) of the acrylic polymer.

[0078] The acrylic adhesive composition may contain any other suitable components as long as they do not impair the effects of the present invention. Examples of such other components include polymer components other than acrylic polymers, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, ultraviolet absorbers, antioxidants, light stabilizers, nucleating agents, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, and the like.

[0079] In this embodiment, the adhesive constituting the adhesive layer 5 includes a tackifier. Examples of tackifiers include terpene-based tackifiers, acrylic oligomers, and hydrocarbon-based tackifiers. The tackifier may include at least one selected from the group consisting of terpene-based tackifiers and acrylic oligomers. Such tackifiers can be used individually or in combination of two or more.

[0080] Examples of terpene-based tackifiers include terpene resins such as α-pinene polymers, β-pinene polymers, and dipentene polymers; and modified terpene resins obtained by modifying these terpene resins (phenol modification, aromatic modification, hydrogenation modification, hydrocarbon modification, etc.). An example of the above-mentioned modified terpene resin is terpene phenol resin.

[0081] Terpene phenol resins refer to polymers containing terpene and phenol residues, and the concept encompasses both copolymers of terpenes and phenol compounds (terpene-phenol copolymer resins) and homopolymers or copolymers of terpenes modified with phenol (phenol-modified terpene resins). Specific examples of terpenes that constitute such terpene phenol resins include monoterpenes such as α-pinene, β-pinene, and limonene (including d-isomers, l-isomers, and d / l-isomers (dipentene)). Hydrogenated terpene phenol resins refer to hydrogenated terpene phenol resins having a structure obtained by hydrogenating such terpene phenol resins. They are sometimes also called hydrogenated terpene phenol resins.

[0082] Examples of hydrocarbon-based tackifying resins include aliphatic (C5) petroleum resins, aromatic (C9) petroleum resins, aliphatic / aromatic copolymer (C5 / C9) petroleum resins, hydrogenated versions thereof (e.g., alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins), various modified versions thereof (e.g., maleic anhydride modified versions), coumarone resins, coumarone indene resins, and other hydrocarbon-based resins.

[0083] The acrylic oligomer preferably has a Tg of about 0°C to about 300°C, more preferably about 20°C to about 300°C, and more preferably about 40°C to about 300°C. By having a Tg within the above range, the adhesive strength can be suitably improved. In some preferred embodiments, from the viewpoint of adhesive cohesiveness, the Tg of the acrylic oligomer is about 30°C or higher, more preferably about 50°C or higher (for example, about 60°C or higher), and from the viewpoint of adhesion, it is preferably about 200°C or lower, more preferably about 150°C or lower, and even more preferably about 100°C or lower (for example, approximately 80°C or lower).

[0084] In this specification, Tg of an acrylic oligomer refers to the Tg determined by Fox's formula based on the composition of the monomer components. Fox's formula is a relationship between the Tg of a copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as shown below.

[0085] 1 / Tg=Σ(Wi / Tgi)

[0086] In the above Fox formula, Tg represents the glass transition temperature of the copolymer (unit: K), Wi represents the weight fraction of monomer i in the copolymer (weight-based copolymerization ratio), and Tgi represents the glass transition temperature of the monomer i homopolymer (unit: K). The Tg of the homopolymer used to calculate Tg is the same as that explained for the homopolymer Tg of acrylic polymer monomers.

[0087] The weight-average molecular weight (Mw) of the acrylic oligomer is typically about 1,000 or more and less than 30,000, preferably about 1,500 or more and less than 20,000, and more preferably about 2,000 or more and less than 10,000. Having Mw within this range is preferable because it provides good adhesion. In some preferred embodiments, the Mw of the acrylic oligomer is about 2,500 or more (e.g., about 3,000 or more), and from the viewpoint of adhesion, it is preferably about 7,000 or less, more preferably about 5,000 or less (e.g., about 4,500 or less, typically about 4,000 or less). The Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and determined as a value equivalent to standard polystyrene. Specifically, it is measured using a Tosoh HPLC-8020 with two TSKgelGMH-H(20) columns at a flow rate of about 0.5 mL / min in tetrahydrofuran solvent.

[0088] Examples of monomers that make up acrylic oligomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate. Examples of (meth)acrylates include alkyl (meth)acrylates such as acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate; esters of (meth)acrylic acid with alicyclic alcohols (alicyclic hydrocarbon group-containing (meth)acrylates) such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; and (meth)acrylates obtained from terpene compound derivative alcohols. Such (meth)acrylates can be used individually or in combination of two or more.

[0089] From the viewpoint of further improving the adhesion of the adhesive layer 5, it is preferable that the acrylic oligomer contains relatively bulky acrylic monomers as monomer units, such as alkyl(meth)acrylates having a branched alkyl group structure, like isobutyl(meth)acrylate and t-butyl(meth)acrylate; esters of (meth)acrylic acid and alicyclic alcohols (alicyclic hydrocarbon group-containing (meth)acrylates), like cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, and dicyclopentanyl(meth)acrylate; aryl(meth)acrylates having a cyclic structure, like phenyl(meth)acrylate and benzyl(meth)acrylate. Furthermore, when ultraviolet light is used during the synthesis of acrylic oligomers or during the preparation of the adhesive layer 5, saturated bonds are preferred because they are less likely to inhibit polymerization. Alkyl (meth)acrylates with branched alkyl groups, or esters with alicyclic alcohols (alicyclic hydrocarbon group-containing (meth)acrylates), can be suitably used as monomers constituting the acrylic oligomers. Note that the above-mentioned branched-chain alkyl (meth)acrylates, alicyclic hydrocarbon group (meth)acrylates, and aryl (meth)acrylates all correspond to (meth)acrylate monomers in the technology disclosed herein. The alicyclic hydrocarbon group may be saturated or unsaturated.

[0090] The proportion of (meth)acrylate monomers (e.g., alicyclic hydrocarbon group-containing (meth)acrylates) in the total monomer components constituting the acrylic oligomer is typically greater than 50% by weight, preferably 60% by weight or more, and more preferably 70% by weight or more (e.g., 80% by weight or more, and even more than 90% by weight or more). In some preferred embodiments, the acrylic oligomer has a monomer composition consisting substantially only of (meth)acrylate monomers.

[0091] In addition to the (meth)acrylate monomers mentioned above, functional group-containing monomers can be used as constituent monomer components of acrylic oligomers. Preferred examples of the functional group-containing monomers include monomers having nitrogen atom-containing rings (typically nitrogen atom-containing heterocycles) such as N-vinyl-2-pyrrolidone and N-acryloylmorpholine; amino group-containing monomers such as N,N-dimethylaminoethyl (meth)acrylate; amide group-containing monomers such as N,N-diethyl (meth)acrylamide; carboxyl group-containing monomers such as AA and MAA; and hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate. These functional group-containing monomers can be used individually or in combination of two or more. Among these, carboxyl group-containing monomers are preferred, and AA is particularly preferred.

[0092] When all monomer components constituting an acrylic oligomer include functional group-containing monomers, the proportion of functional group-containing monomers (for example, carboxyl group-containing monomers such as AA) in the total monomer components is appropriately approximately 1% by weight or more, preferably 2% by weight or more, more preferably 3% by weight or more, and appropriately approximately 15% by weight or less, preferably 10% by weight or less, and more preferably 7% by weight or less.

[0093] Acrylic oligomers can be formed by polymerizing their constituent monomer components. The polymerization method and polymerization mode are not particularly limited, and various conventionally known polymerization methods (e.g., solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be employed in appropriate manner. The types of polymerization initiators that can be used as needed (e.g., azo polymerization initiators such as AIBN) are generally as exemplified in the synthesis of acrylic polymers, and the amount of polymerization initiator and the amount of chain transfer agent such as n-dodecyl mercaptan used optionally are appropriately set based on common technical knowledge to achieve the desired molecular weight, so a detailed explanation is omitted here.

[0094] From the above viewpoint, suitable acrylic oligomers include, for example, homopolymers of dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), 1-adamantyl methacrylate (ADMA), and 1-adamantyl acrylate (ADA), as well as copolymers of CHMA and isobutyl methacrylate (IBMA), copolymers of CHMA and IBXMA, copolymers of CHMA and acryloylmorpholine (ACMO), copolymers of CHMA and diethylacrylamide (DEAA), copolymers of CHMA and AA, copolymers of ADA and methyl methacrylate (MMA), copolymers of DCPMA and IBXMA, copolymers of DCPMA and MMA, and the like.

[0095] When the adhesive layer 5 contains an acrylic oligomer, the amount is not particularly limited, but it is appropriate to have at least 0.1 parts by weight (for example, 1 part by weight or more) per 100 parts by weight of the acrylic polymer. From the viewpoint of better exhibiting the effects of the acrylic oligomer, in some embodiments, the amount of the acrylic oligomer is approximately 3 parts by weight or more, may be approximately 5 parts by weight or more, may be approximately 10 parts by weight or more, or may be approximately 12 parts by weight or more. Furthermore, from the viewpoint of compatibility with the acrylic polymer, it is appropriate to have an amount of the acrylic oligomer less than 50 parts by weight (for example, less than 40 parts by weight) per 100 parts by weight of the acrylic polymer, preferably less than 30 parts by weight, more preferably approximately 25 parts by weight or less, and even more preferably approximately 20 parts by weight or less. In some embodiments, the amount of the acrylic oligomer may be 10 parts by weight or less, may be 5 parts by weight or less, or may be 1 part by weight or less (for example, less than 1 part by weight) per 100 parts by weight of the acrylic polymer. The adhesive layer 5 may be substantially free of acrylic oligomers.

[0096] In some embodiments, the adhesive layer 5 may contain one or more of the above-mentioned tackifying resins and one or more of acrylic oligomers. C of the acrylic oligomer content in the adhesive layer 5 O [weight] Percentage of tackifying resin content C T [weight %] ratio (C T / C O ) is not particularly limited. In some embodiments, the above (C T / C O The ratio (C) is appropriate to be 0.1 or more on a weight basis, preferably 0.5 or more, may be 1 or more (e.g., greater than 1), may be 2 or more, may be 3 or more, or may be 4 or more. T / C O The larger the (C) is, the easier it is to obtain the tackifying effect of the resin. Also, in some embodiments, the above (C) T / C O The ratio of ) is appropriately set to, for example, 10 or less by weight, preferably 8 or less, but may also be 6 or less, or even 5 or less. This allows the desired effects of using the acrylic oligomer to be exhibited.

[0097] The total amount of acrylic polymer and tackifier in the adhesive layer 5 is appropriately set to allow the effects of the disclosed technology to be exhibited and is not limited to a specific range. In some preferred embodiments, the total amount of acrylic polymer and tackifier in the adhesive layer 5 is suitable to account for more than 50% by weight of the adhesive layer 5, preferably about 70% by weight or more, more preferably about 90% by weight or more, and even more preferably 95% by weight or more (for example, 95% by weight or more and 100% by weight or less than 100% by weight), and may be 98% by weight or more.

[0098] It is preferable that the tackifier is substantially free of the specific component SI. In other words, it is preferable that the content of the specific component SI in the tackifier is less than 0.1% by weight.

[0099] The tackifier preferably contains substantially no rosin ester. In other words, the rosin ester content in the tackifier is preferably less than 0.1% by weight.

[0100] As shown in Figures 1 and 2, the outer circumference of the porous film 1 and the outer circumference of the adhesive layer 5 coincide when viewed perpendicular to the main surface of the porous film 1. Furthermore, the shape of the adhesive layer 5 corresponds to the peripheral edge of the porous film 1 when viewed perpendicular to the main surface of the porous film 1. As shown in Figures 1 and 2, the areas of the porous film 1 where the adhesive layer 5 is not bonded can be designated as the ventilation area 11 of the ventilation member 4A. The ventilation area 11 is surrounded by the area where the porous film 1 and the adhesive layer 5 are bonded (bonding area). However, the shape of the adhesive layer 5 is not limited to the examples in Figures 1 and 2.

[0101] The area of ​​the ventilation region 11 is, for example, 40 mm². 2 The following applies: A ventilation member 4 whose ventilation area 11 falls within this range is suitable for placement on objects having small-diameter openings, for example. Examples of objects having small-diameter openings include wearable devices such as smartwatches and wristbands; and information and communication devices such as mobile phones, smartphones, and tablets.

[0102] The upper limit of the area of ​​the ventilation region 11 is 30 mm 2 Below, 20mm 2 Below, another 10mm 2 The following is also possible: The lower limit of the area of ​​the ventilation region 11 is, for example, 0.008 mm. 2 That concludes the explanation. However, the area of ​​the ventilation region 11 may be larger depending on the type of object on which the ventilation member 4 is placed.

[0103] The thickness of the adhesive layer 5 is preferably 200 μm or less. For example, in the example shown in Figure 2, the thickness of the first adhesive layer 5A and the thickness of the second adhesive layer 5B are preferably both 200 μm or less.

[0104] The upper limit of the thickness of the adhesive layer 5 may be 190 μm or less, 180 μm or less, or even 170 μm or less. The lower limit of the thickness of the adhesive layer 5 is, for example, 1 μm or more. The lower limit of the thickness of the adhesive layer 5 may be 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or even 50 μm or more.

[0105] The thickness of the adhesive layer 5 can be determined, for example, by measuring the thickness at any five points on the adhesive layer 5 of the ventilation member 4 using a dial gauge and taking the average of these measurements. Alternatively, the thickness of the adhesive layer 5 can be determined by measuring the thickness at any five points on the adhesive layer 5 in the SEM image of the cross-section of the ventilation member 4 and taking the average of these measurements.

[0106] In the example shown in Figure 2, the thickness of the ventilation member 4 (4B) is preferably, for example, 300 μm or less. When the thickness is within the above numerical range, a ventilation member 4 suitable for suppressing a decrease in air permeability is easily obtained. In this specification, "thickness of the ventilation member 4" means the thickness including the adhesive layer 5.

[0107] The thickness of the ventilation member 4 can be determined by measuring the thickness at any five points on the ventilation member 4 using, for example, a dial gauge, and taking the average of these measurements. Alternatively, the thickness of the ventilation member 4 can be determined by measuring the thickness at any five points in the SEM image of the cross-section of the ventilation member 4 and taking the average of these measurements. However, all five arbitrary points must include the adhesive layer 5.

[0108] The upper limit of the thickness of the ventilation member 4 (4B) may be 290 μm or less, 270 μm or less, or even 250 μm or less. The lower limit of the thickness of the ventilation member 4 (4B) is, for example, 10 μm or more. The lower limit of the thickness of the ventilation member 4 (4B) may be 25 μm or more, 50 μm or more, 75 μm or more, or even 100 μm or more.

[0109] (Porous Film) Figure 3 is a schematic cross-sectional view showing an example of the porous film 1. As described above, the porous film 1 mainly contains a thermoplastic resin that does not contain fluorine. Here, "main component" means the component that is present in the most abundant amount by weight in the porous film 1. By containing a thermoplastic resin as the main component, the porous film 1 can be bonded to the housing of a smartwatch, etc., by heat fusion without using adhesives or other adhesives.

[0110] Examples of fluorine-free thermoplastic resins include polyolefin resins, polyester resins, and polyimide resins. A fluorine-free thermoplastic resin may contain at least one selected from the group consisting of polyolefin resins, polyester resins, and polyimide resins.

[0111] The fluorine-free thermoplastic resin may contain at least one selected from the group consisting of polyolefin resins and polyester resins. If the thermoplastic resin is a polyolefin resin or a polyester resin, a breathable member 4 suitable for suppressing a decrease in breathability is easily obtained.

[0112] The thermoplastic resin that does not contain fluorine may also contain polyolefin resin. The thermoplastic resin that does not contain fluorine may also be a polyolefin resin. If the thermoplastic resin is a polyolefin resin, it is easier to obtain a breathable member 4 that is suitable for suppressing a decrease in breathability.

[0113] Examples of polyolefin resins include polyethylene (PE) resin, polymethylpentene (PMP) resin, and polypropylene (PP) resin.

[0114] Polyolefin resin may also be polyethylene (PE) resin.

[0115] The polyolefin resin may also be polymethylpentene (PMP) resin. Polymethylpentene resin is a homopolymer or copolymer of poly(4-methylpentene-1) resin, poly(3-methylpentene-1) resin, etc. Copolymers include random copolymers and block copolymers. From the viewpoint of heat resistance and moldability, a homopolymer of poly(4-methylpentene-1) resin is preferred.

[0116] The polyolefin resin may also be poly(4-methylpentene-1) resin. Poly(4-methylpentene-1) resin means a homopolymer of 4-methylpentene-1, or a copolymer of 4-methylpentene-1 and at least one type of α-olefin. The composition ratio of 4-methylpentene-1 to α-olefin contained in the copolymer can be adjusted within a range of melting points of 180°C or higher.

[0117] The thermoplastic resin that does not contain fluorine may also contain polyester resin. Even if the thermoplastic resin is polyester resin, a breathable member 4 suitable for suppressing a decrease in breathability can be obtained.

[0118] Examples of polyester resins include polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polybutylene terephthalate (PBT) resin, polybutylene naphthalate (PBN) resin, polyethylene furanoate (PEF) resin, and polytrimethylene terephthalate resin.

[0119] The polyester resin may also be polyethylene terephthalate (PET) resin.

[0120] The thermoplastic resin that does not contain fluorine may also contain polyimide (PI) resin. The thermoplastic resin that does not contain fluorine may also be polyimide resin. Even if the thermoplastic resin is polyimide resin, a breathable member 4 suitable for suppressing a decrease in breathability can be obtained.

[0121] The fluorine-free thermoplastic resin may be a thermoplastic resin with a melting point of 180°C or higher and 300°C or lower. If the melting point of the thermoplastic resin is 180°C or higher, sufficient heat resistance can be ensured in the porous film 1. If the melting point of the thermoplastic resin is 300°C or lower, the porous film 1 can be manufactured, for example, by melt molding.

[0122] The melting point of the thermoplastic resin may be 200°C or higher and 280°C or lower, and may be 220°C or higher and 260°C or lower.

[0123] The porous film 1 may contain additives other than thermoplastic resin, such as plasticizers and antioxidants.

[0124] The porous film 1 is in the form of a film or a sheet. The thickness of the porous film 1 is preferably 500 μm or less. When the thickness is within the above numerical range, a breathable member 4 suitable for suppressing a decrease in breathability is easily obtained.

[0125] The thickness of the porous film 1 can be determined by measuring the thickness at any five points on the porous film 1 using, for example, a dial gauge, and taking the average of these measurements. Alternatively, the thickness of the porous film 1 can be determined by measuring the thickness at any five points in the SEM image of the cross-section of the porous film 1 and taking the average of these measurements.

[0126] The upper limit of the thickness of the porous film 1 may be 400 μm or less, 300 μm or less, 200 μm or less, or even 100 μm or less. The lower limit of the thickness of the porous film 1 is, for example, 1 μm or more. The lower limit of the thickness of the porous film 1 may be 2 μm or more, 3 μm or more, 4 μm or more, or even 5 μm or more.

[0127] The porous film 1 may be a stretched film. If the porous film 1 is a stretched film, it is easier to control properties such as air permeability and sound permeability. The stretched film may be a biaxially oriented film or a uniaxially oriented film.

[0128] At least one main surface of the porous film 1 may be subjected to a surface modification treatment other than liquid-repellent treatment. Examples of surface modification treatments include chemical treatment, sputter etching, and plasma treatment. In the areas where the surface modification treatment has been applied, the bonding properties of the porous film 1 are improved.

[0129] (Film Member) The ventilation member 4 may further include a breathable support material 3 laminated on the porous film 1. Hereinafter, the laminate of the porous film 1 and the breathable support material 3 will be referred to as the film member 2. In the example of Figure 1, the ventilation member 4 (4A) may include the film member 2 instead of the porous film 1.

[0130] Figure 4 is a schematic cross-sectional view showing an example of the film member 2. The breathable support material 3 improves the strength and handling of the film member 2.

[0131] The breathable support material 3 typically has higher breathability in the thickness direction compared to the porous film 1. Examples of breathable support material 3 include woven fabrics, nonwoven fabrics, nets, and meshes. Examples of materials constituting the breathable support material 3 include polyester such as polyethylene terephthalate (PET), polyolefins such as polyethylene (PE) and polypropylene (PP), and aramid resins. The shape of the breathable support material 3 may be the same as or different from the shape of the porous film 1 when viewed perpendicular to the main surface of the film member 2. The breathable support material 3 may have a peripheral edge that corresponds to the peripheral edge of the porous film 1 when viewed perpendicular to the main surface of the film member 2.

[0132] The film member 2 in Figure 4 includes one breathable support member 3 arranged on one main surface of the porous film 1. In the example shown in Figure 4, the breathable support member 3 is arranged on one main surface (the second main surface 1b). However, the breathable support member 3 may also be arranged on the other main surface (the first main surface 1a). The film member 2 may include two or more breathable support members 3. In the film member 2, the breathable support members 3 may be arranged on both surfaces of the porous film 1. The porous film 1 and the breathable support member 3 may be joined by welding such as heat welding and ultrasonic welding, or by adhesives or other adhesives.

[0133] The film member 2 may include any other layers and / or members besides those described above.

[0134] The thickness of the film member 2 is, for example, 1 to 300 μm. The thickness of the film member 2 may also be 50 to 200 μm.

[0135] The basis weight of the film material 2 is, for example, 1.0 to 200.0 g / m². 2 The basis weight of film member 2 is 10.0 to 100.0 g / m². 2 That's fine.

[0136] The film member 2 may have the same properties as the porous film 1, such as breathability and sound permeability.

[0137] The film member 2 may be treated with a liquid-repellent treatment and / or a coloring treatment.

[0138] A modified example 2 of the ventilation member 4 of this embodiment is shown in Figure 5. The ventilation member 4 (4C) in Figure 5 further comprises a base material layer 6 arranged on one main surface side of the porous film 1, and the porous film 1 and the adhesive layer 5 are joined via the base material layer 6, except that it has the same configuration as the ventilation member 4A in Figure 1. The base material layer 6 improves the strength and handling of the ventilation member 4 and suppresses damage to the porous film 1 during handling or placement on an object.

[0139] Examples of materials constituting the base layer 6 include polyolefins such as PE and PP, polyesters such as PET, silicone resins, polycarbonates, polyimides, polyamide-imides, polyphenylene sulfide, polyetheretherketone (PEEK), polyvinyl chloride, fluororesins, and metals such as aluminum and stainless steel. Examples of fluororesins include PTFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer (ETFE). However, the materials constituting the base layer 6 are not limited to the above examples.

[0140] As shown in Figure 5, the outer periphery of the porous film 1 and the outer periphery of the base layer 6 coincide when viewed perpendicular to the main surface of the porous film 1. Furthermore, the shape of the base layer 6 corresponds to the peripheral edge of the porous film 1 when viewed perpendicular to the main surface of the porous film 1. The area of ​​the porous film 1 where the base layer 6 is not bonded can be used as the ventilation area 11 of the ventilation member 4C. However, the shape of the base layer 6 is not limited to the example in Figure 5.

[0141] The porous film 1 and the base layer 6 may be joined by an adhesive or bonding agent. The porous film 1 and the base layer 6 may be joined by welding such as heat welding and ultrasonic welding. The porous film 1 and the base layer 6 may be joined by an adhesive layer. The adhesive layer may have the same structure as the adhesive layer 5. The base layer 6 may be a single-sided adhesive tape or a double-sided adhesive tape.

[0142] A modified example 3 of the ventilation member 4 of this embodiment is shown in Figure 6. The ventilation member 4 (4D) in Figure 6 has the same configuration as the ventilation member 4C in Figure 5, except that it further comprises a base material layer 6 (6B) arranged on the other main surface side of the porous film 1. The porous film 1 is sandwiched between a pair of base material layers 6 (6A, 6B). This sandwiching structure further improves the strength and handling of the ventilation member 4.

[0143] As shown in Figure 6, the base layer 6 may include a first base layer 6A bonded to one main surface (first main surface 1a) of the porous film 1 and a second base layer 6B bonded to the other main surface (second main surface 1b) of the porous film 1.

[0144] A modified example 4 of the ventilation member 4 of this embodiment is shown in Figure 7. The ventilation member 4 (4E) in Figure 7 has the same configuration as the ventilation member 4B in Figure 2, except that it further includes a release liner 7 and the porous film 1 and the release liner 7 are joined via an adhesive layer 5 (5B).

[0145] As shown in Figure 7, the ventilation member 4 (4E) further comprises a peel-off liner 7, and a second adhesive layer 5B may be placed between the peel-off liner 7 and the porous film 1, with the second adhesive layer 5B being bonded to the peel-off liner 7.

[0146] The peel-off liner 7 has tabs that protrude outward from the outer circumference of the porous film 1 when viewed perpendicular to the main surface of the porous film 1. The ventilation member 4E can be handled and placed on the surface of an object by gripping the tabs. The peel-off liner 7 is usually removed when the ventilation member 4E is used. The peel-off liner 7 may be made of a material similar to the material that constitutes the base layer 6, for example.

[0147] A modified example 5 of the ventilation member 4 of this embodiment is shown in Figure 8. The ventilation member 4 (4F) in Figure 8 further comprises an adhesive layer 5 (5B) and a release liner 7, and has the same configuration as the ventilation member 4D in Figure 6, except that the base layer 6 (6B) and the release liner 7 are joined via the adhesive layer 5 (5B).

[0148] (Method for manufacturing the ventilation member) The ventilation member 4 described above can be manufactured by bonding an adhesive layer 5 to one or both main surfaces of the porous film 1. The porous film 1 can be manufactured, for example, by the following method.

[0149] A method for producing the porous film 1 includes, for example, kneading a composition containing a fluorine-free thermoplastic resin and a plasticizer using a twin-screw extruder, then extruding the kneaded mixture (step S1), obtaining a molded body while cooling the extruded mixture (step S2), stretching the molded body to obtain a sheet (step S3), and removing the plasticizer from the sheet (step S4).

[0150] Steps S1 and S2 correspond to the process of producing a precursor for the porous film 1. Steps S3 and S4 correspond to the process of growing the porous structure.

[0151] Step S1 is carried out, for example, at a temperature of 50 to 300°C.

[0152] As a fluorine-free thermoplastic resin, for example, polymethylpentene resin can be used.

[0153] The composition containing the thermoplastic resin and plasticizer may also contain other resins, such as polyethylene, polypropylene, poly-1-butene, and cyclic polyolefins, to the extent that they do not affect the properties of the porous film 1.

[0154] A plasticizer is a non-volatile solvent that, when mixed with a thermoplastic resin such as polymethylpentene resin, forms a mixture above the melting point of the resin, and exhibits thermally induced phase separation when the mixture is cooled. The form of the plasticizer may be liquid or solid at room temperature. The plasticizer may be used alone or in a mixture of two or more plasticizers. For example, such a plasticizer may have a kinematic viscosity of 50 to 150 mmHg at 40°C. 2 The / s option is available.

[0155] The mixing ratio of the thermoplastic resin and the plasticizer is set so that a uniform kneaded product can be obtained in step S1 and a molded article can be formed in step S2. Specifically, the weight ratio of the thermoplastic resin in the mixture containing the thermoplastic resin and the plasticizer is, for example, 20% by weight or more and 80% by weight or less, preferably 30% by weight or more and 70% by weight. By having a weight ratio of 20% by weight or more of the thermoplastic resin, it is avoided that the viscosity of the mixture will decrease too much. By having a weight ratio of 80% by weight or less of the thermoplastic resin, a good porous structure is easily obtained.

[0156] The composition containing the thermoplastic resin and plasticizer may further contain additives such as antioxidants, nucleating agents, antistatic agents, flame retardants, lubricants, ultraviolet absorbers, colorants, and inorganic fillers for strength improvement, depending on the purpose.

[0157] In step S2, for example, the kneaded material is stretched while being cooled using metal rolls with a controlled surface temperature to obtain a sheet-like molded body. There may be multiple metal rolls. The sheet-like molded body may be formed while being cooled by passing it through multiple metal rolls.

[0158] In step S3, the molded body is stretched at least once in the longitudinal direction and at least once in the transverse direction. Step S3 is carried out, for example, using a longitudinal stretcher and a transverse stretcher. Step S3 may also be carried out using a biaxial stretcher. The molded body may be biaxially stretched sequentially or simultaneously. For example, the transverse stretching may be carried out after the longitudinal stretching. As a result of step S3, pores are generated in the molded body.

[0159] The stretching temperature may be 20°C to 240°C, 50°C to 230°C, or even 100°C to 220°C for both longitudinal and transverse stretching.

[0160] The stretching ratio may be 2.0 to 10.0 times, 2.0 to 8.0 times, or even 2.0 to 5.0 times, in the uniaxial direction of the longitudinal and / or transverse direction.

[0161] The strain rate during stretching may be 1% / second to 10% / second, 1% / second to 8% / second, or even 1% / second to 5% / second in the longitudinal and / or transverse directions. When the strain rate is within the above numerical range, a porous membrane exhibiting good air permeability is obtained.

[0162] In step S4, for example, the plasticizer is extracted and removed from the sheet using an extraction solvent. This yields a porous film 1.

[0163] As the extraction solvent, a solvent that is a poor solvent for thermoplastic resins such as polymethylpentene resin, but a good solvent for plasticizers, and whose boiling point is lower than the melting point of the porous film 1 is preferably used. Examples of such extraction solvents include hydrocarbons such as n-hexane and cyclohexane; halogenated hydrocarbons such as methylene chloride and 1,1,1-trichloroethane; alcohols such as ethanol and isopropanol; ethers such as diethyl ether and tetrahydrofuran; and ketones such as acetone and 2-butanone. Considering safety, alcohols and ketones are preferably used. Methyl ethyl ketone (MEK) may also be used as the extraction solvent.

[0164] Between step S3 and step S4, heat setting may be performed on the sheet. Heat setting can be performed, for example, using a hot air circulating oven. By performing heat setting, the thermal shrinkage of the sheet after stretching can be reduced. The heat setting temperature is, for example, 50°C to 240°C. The heat setting temperature may also be 100°C to 230°C, or even 150°C to 220°C.

[0165] After step S3, between steps S3 and S4, or both after step S3 and after S4, a heat setting process may be performed. Methods for heat setting include fixing the width direction with a tenter and continuously passing the material through the heat treatment furnace, applying appropriate tension and continuously passing the material through the heat treatment furnace without fixing the width direction, or winding the material onto a roll and feeding it into the heat treatment furnace in batches.

[0166] [Component Supply Assembly] The ventilation member 4 can be supplied, for example, by a component supply assembly. An example of a component supply assembly, which is a method of supplying the ventilation member 4, is shown in Figure 9. The component supply assembly 20 (20A) in Figure 9 comprises a ventilation member 4 (4A) which is placed on the surface of an object having an opening, and a base sheet 9 on which the ventilation member 4 (4A) is placed. The component supply assembly 20A includes a ventilation member 4A as the ventilation member 4. The ventilation member 4A comprises a porous film 1 which has a shape that covers the opening when placed on the surface of an object, and an adhesive layer 5 which is bonded to the porous film 1.

[0167] The ventilation member 4 (4A) is placed on the base sheet 9 via an adhesive layer 5. The member supply assembly 20 (20A) allows for efficient supply of the ventilation member 4 to, for example, a process of placing it on the surface of an object.

[0168] The ventilation member 4 may be placed on the base sheet 9 via an adhesive layer provided on the surface on which the ventilation member 4 is placed. The adhesive layer on the placement surface is preferably weakly adhesive.

[0169] Although not shown in the diagram, a plurality of ventilation members 4 may be arranged on the surface of the base sheet 9.

[0170] Examples of materials constituting the base sheet 9 include paper, metal, resin, and composite materials thereof. Examples of metals include stainless steel and aluminum. Examples of resins include polyester such as PET, and polyolefins such as PE and PP. However, the materials constituting the base sheet 9 are not limited to the above examples. The base sheet 9 may be in the form of a single sheet or a strip. If the base sheet 9 is in the form of a strip, the component supply assembly 20 may be wound to form a wound body.

[0171] Examples of objects on which the ventilation member 4 is placed include the housings of electronic devices and the housings of vehicle electrical components. The ventilation member 4 can be placed on the outer and / or inner surfaces of the housing. In this case, the opening may be a ventilation opening and / or sound vent provided in the housing. Examples of electronic devices include wearable devices such as smartwatches and wristbands; various cameras including action cameras and security cameras; information and communication devices such as mobile phones, smartphones and tablets; virtual reality (VR) devices; augmented reality (AR) devices; and sensor devices. Examples of vehicle electrical components include lamps and ECUs. However, the objects are not limited to the above examples.

[0172] Foreign matter whose passage is prevented by the arrangement of the ventilation member 4 includes, for example, particles such as dust and liquid water such as water droplets.

[0173] A modified example of the component supply assembly 20 of this embodiment is shown in Figure 10. The component supply assembly 20 (20B) in Figure 10 has the same configuration as the component supply assembly 20A in Figure 9, except that it is equipped with the ventilation member 4E shown in Figure 7 as the ventilation member 4.

[0174] A modified example 2 of the component supply assembly 20 of this embodiment is shown in Figure 11. The component supply assembly 20 (20C) in Figure 11 has the same configuration as the component supply assembly 20A in Figure 9, except that it is equipped with the ventilation member 4F shown in Figure 8 as the ventilation member 4.

[0175] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to the examples and comparative examples shown below.

[0176] [Preparation of Porous Film] (Porous Film A) Poly(4-methylpentene-1) resin (manufactured by Mitsui Chemicals, RT18) was used as the thermoplastic resin that does not contain fluorine. As a plasticizer, a resin with a kinematic viscosity of 110 mm at 40°C was used. 2 Liquid paraffin (MORESCO) with a concentration of 1 / s was used. Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (BASF Japan) was used as an antioxidant. A mixture was obtained by mixing 50.0% by weight of thermoplastic resin, 49.8% by weight of plasticizer, and 0.2% by weight of antioxidant. The mixture was kneaded using a twin-screw extruder (TEX25αIII, Japan Steel Works, Ltd.), and then the kneaded material was extruded onto metal rolls whose surface temperature was controlled by a hanger coat die. The extrusion was carried out with the extruder cylinder temperature of the twin-screw extruder set to 235°C. Next, a sheet-like molded body was obtained by stretching the extruded kneaded material while cooling it using metal rolls. Next, the molded body was stretched in the longitudinal direction using a longitudinal stretcher under conditions of a stretching temperature of 100°C and a stretching ratio of 2 times (longitudinal direction). Next, the molded body was stretched transversely using a transverse stretcher under the conditions of a stretching temperature of 100°C and a stretching ratio of 2x (transverse direction). The strain rate during stretching was 1% / second (0.655 mm / second) in both the longitudinal and transverse directions. This yielded a sheet. Longitudinal stretching was performed 5 minutes after the molded body was placed in the furnace set to the stretching temperature. Finally, using methyl ethyl ketone (MEK) as the extraction solvent, the sheet was immersed in MEK at room temperature for 2 minutes to perform an extraction operation. This removed the plasticizer from the sheet. The extraction operation was performed with the sheet fixed to a stainless steel frame to suppress shrinkage. The porous film obtained in this way was designated as porous film A.

[0177] (Porous Film B) As a thermoplastic resin that does not contain fluorine, soluble polyimide (KPI-MX300F, manufactured by Kawamura Sangyo Co., Ltd.) was used. 10 g of soluble polyimide was dissolved in 70 g of 1-methyl-2-pyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd.) to obtain a solution. Then, 20 g of polyethylene glycol 200 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the solution and stirred uniformly to obtain a PI solution. The PI solution was coated onto a PTFE porous membrane (TEMISH®, manufactured by Nitto Denko Corporation) as a substrate to a thickness of 50 μm using an applicator to obtain a coating film. Next, the coating film was left to stand for 10 minutes inside a constant temperature and humidity chamber adjusted to a temperature of 10°C and a relative humidity of 70% to promote phase separation. Next, the coating film was immersed in a 30°C water bath for 10 minutes to perform solvent extraction. Next, the coating was fixed to a square-shaped member with sides measuring 10 cm in plan view, and dried at 80°C for 10 minutes. After that, the coating was dried at 250°C for 2 minutes. This formed a porous film on the substrate. The porous film was peeled off the substrate. The porous film obtained in this way was designated as porous film B.

[0178] (Porous Film C) A polyethylene terephthalate (PET) non-porous sheet (manufactured by Toray Industries, Ltd., Lumirror: 50 μm thick) was used as the base sheet for a porous film mainly composed of a thermoplastic resin that does not contain fluorine. Next, straight holes were formed in the base sheet by ion beam irradiation and etching. The diameter of the obtained straight holes was 1.0 μm, and the porosity of the sheet after the formation of the straight holes was 4.7%. The ion species of the ion beam used for ion beam irradiation was Xe, the acceleration voltage was 560 MeV, and the irradiation density was 6.0 × 10⁻⁶ 6 ion / cm 2 The vacuum level is 10 -3 The pressure was on the order of Pa. The etching solution used was a 0.5 M NaOH solution at approximately 60°C. The porous film obtained in this way was designated as porous film C.

[0179] (Porous Film D) As a thermoplastic resin that does not contain fluorine, polyethylene (PE) resin (GUR4150, manufactured by Celanese) was used. Using a longitudinal stretcher, the sheet-like molded body was stretched longitudinally under the conditions of a stretching temperature of 90°C and a stretching ratio of 6 times (longitudinal direction). Next, using a transverse stretcher, the sheet-like molded body was stretched transversely under the conditions of a stretching temperature of 105°C and a stretching ratio of 9 times (transverse direction). A porous film was obtained by the same method as porous film A, excluding these steps. The porous film obtained in this way was designated as porous film D.

[0180] [Preparation of the adhesive] (Acrylic polymer A1) 95 parts by weight of n-butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) as monomer components, along with 233 parts by weight of ethyl acetate as a polymerization solvent, were placed inside a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel. The mixture was stirred for 2 hours while introducing nitrogen gas. After removing oxygen from the polymerization system in this manner, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added, and polymerization was carried out at 60°C for 8 hours. This yielded a solution of acrylic polymer A1. The weight-average molecular weight (Mw) of acrylic polymer A1 in the solution was approximately 70 × 10⁻⁶. 4 That was the case.

[0181] (Acrylic Polymer A2) 80 parts by weight of 2-ethylhexyl acrylate (2EHA), 20 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 5 parts by weight of 2-hydroxyethyl acrylate (HEA) as monomer components, along with 200 parts by weight of ethyl acetate as a polymerization solvent, were placed in a separable flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen from the polymerization system in this manner, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added, and polymerization was carried out at 63°C for 10 hours. Subsequently, toluene was added to obtain acrylic polymer A2 with a solid content of 30% by weight.

[0182] (Acrylic polymer A3) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel, 100 parts by weight of n-butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) as monomer components, 0.2 parts by weight of benzoyl peroxide as a polymerization initiator, and 230 parts by weight of toluene as a polymerization solvent were added and mixed to obtain a mixture. Then, nitrogen gas was introduced while gently stirring the mixture, and polymerization was carried out for about 6 hours while maintaining the liquid temperature at around 60°C. This obtained a solution of acrylic polymer A3. The weight-average molecular weight (Mw) of acrylic polymer A3 in the solution was 55 × 10⁻⁶. 4 That was the case.

[0183] (Acrylic Polymer A4) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel, 80 parts by weight of butyl acrylate (BA), 20 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid (AA), 5 parts by weight of vinyl acetate, and 0.1 parts by weight of 2-hydroxyethyl acrylate (HEA) as monomer components, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 69 parts by weight of toluene and 163 parts by weight of ethyl acetate as polymerization solvents were added and mixed to obtain a mixture. Then, polymerization was carried out at 60°C for 6 hours while introducing nitrogen gas. This obtained a solution of acrylic polymer A4.

[0184] [Preparation of Tackifier] (Acrylic Oligomer B1) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel, 95 parts by weight of cyclohexyl methacrylate (CHMA) and 5 parts by weight of acrylic acid (AA) as monomer components, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 230 parts by weight of toluene as a polymerization solvent were added, and the mixture was stirred for 1 hour while introducing nitrogen gas. After removing oxygen from the polymerization system in this way, the temperature was raised to 85°C and polymerization was carried out for 5 hours. This yielded acrylic oligomer B1 with a solid content of 50% by weight. The weight-average molecular weight (Mw) of the obtained acrylic oligomer B1 was 3600.

[0185] (Acrylic Oligomer B2) 40 parts by weight of dicyclopentanyl methacrylate (DCPMA) (manufactured by Hitachi Chemical Co., Ltd., FA-513M) and 60 parts by weight of methyl methacrylate as monomer components, 3.0 parts by weight of α-thioglycerol as a chain transfer agent, and 100 parts by weight of toluene as a polymerization solvent were placed in a four-necked flask and mixed to obtain a mixture. The mixture was stirred at 70°C for 1 hour under a nitrogen atmosphere, then 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added, and the mixture was reacted at 70°C for 2 hours, followed by a reaction at 80°C for 2 hours to obtain a reaction solution. The reaction solution was left to stand under a temperature atmosphere of 130°C, and toluene, chain transfer agent, and unreacted monomers were removed by drying. This obtained solid acrylic oligomer B2. The weight-average molecular weight (Mw) of the obtained acrylic oligomer B2 was 2700.

[0186] [Example 1] As the porous film for Example 1, porous film A was used. 100 parts by weight of acrylic polymer A1 was mixed with 25 parts by weight of acrylic oligomer B1, 1 part by weight of isocyanate crosslinking agent, and 0.075 parts by weight of epoxy crosslinking agent, and the mixture was stirred. This prepared adhesive composition α1. "Coronate L" manufactured by Nippon Polyurethane Industries Co., Ltd. was used as the isocyanate crosslinking agent. "TETRAD-C (1,3-bis(N,N-diglycidylaminomethyl)cyclohexane)" manufactured by Mitsubishi Gas Chemical Company, Ltd. was used as the epoxy crosslinking agent. Using adhesive composition α1, an adhesive layer with a thickness of 44 μm was formed on both sides of a PET film substrate (Toray Industries, Ltd., Lumirror: thickness 12 μm). In this way, the double-sided adhesive sheet with substrate of Example 1 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of a porous film A that had been punched out in a circular shape with a diameter of 5.8 mm. This resulted in the ventilation member of Example 1. The ventilation member of Example 1 had the configuration of ventilation member 4B shown in Figure 2.

[0187] [Example 2] In Example 2, porous film A was used as the porous film. Using the adhesive composition α1 prepared in Example 1, an adhesive layer with a thickness of 50 μm was formed on both sides of a polyethylene foam (thickness 100 μm). In this way, a double-sided adhesive sheet with a substrate of Example 2 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film A, which had been punched out in a circular shape with a diameter of 5.8 mm. This obtained the breathable member of Example 2. The breathable member of Example 2 had the form of breathable member 4B in Figure 2.

[0188] [Example 3] Porous film A was used as the porous film for Example 3. 100 parts by weight of acrylic polymer A2 was mixed with 10 parts by weight of acrylic oligomer B2, 0.5 parts by weight of isocyanate crosslinking agent, and 0.3 parts by weight of silane coupling agent, and the mixture was stirred. This prepared adhesive composition α2. Mitsui Chemicals' "Takenate D-110N" was used as the isocyanate crosslinking agent. Shin-Etsu Chemical Co., Ltd.'s "KBM-403" was used as the silane coupling agent. Adhesive composition α2 was applied to the peeled surface of a polyethylene terephthalate (PET) separator (Mitsubishi Plastics, MRF75) whose surface had been peeled, so that the thickness after drying was 100 μm, forming a coating film. The coating film was heated at 60°C for 3 minutes under normal pressure, and then heated at 155°C for 4 minutes to dry. The dried coating film was aged at 50°C for 72 hours. In this way, the substrate-less double-sided adhesive sheet of Example 3 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of a porous film A that had been punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Example 3. The ventilation member of Example 3 had the configuration of ventilation member 4B in Figure 2.

[0189] [Example 4] As the porous film for Example 4, porous film A was used. To 100 parts by weight of acrylic polymer A1, 20 parts by weight of terpene phenol resin C1 (Yamaha Chemical Co., Ltd., YS Polystar S145) as a tackifier, 2.0 parts by weight of isocyanate crosslinking agent and 0.075 parts by weight of epoxy crosslinking agent were added and stirred. This prepared adhesive composition β1. The isocyanate crosslinking agent and epoxy crosslinking agent were the same as those used in Example 1. Using adhesive composition β1, an adhesive layer with a thickness of 14 μm was formed on both sides of a PET film substrate (Toray Industries, Inc., Lumirror: thickness 12 μm). In this way, a double-sided adhesive sheet with a substrate of Example 4 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film A, which had been punched out in a circular shape with a diameter of 5.8 mm. This obtained the breathable member of Example 4. The ventilation member of Example 4 had the configuration of ventilation member 4B in Figure 2.

[0190] [Example 5] Porous film A was used as the porous film for Example 5. 100 parts by weight of acrylic polymer A3 was mixed with 20 parts by weight of terpene phenol resin C2 (Yamaha Chemical Co., Ltd., YS Polystar K125) as a tackifier, 2.0 parts by weight of isocyanate crosslinking agent, and 0.075 parts by weight of epoxy crosslinking agent, and stirred. This prepared adhesive composition β2. The isocyanate crosslinking agent and epoxy crosslinking agent were the same as those used in Example 1. Using adhesive composition β2, an adhesive layer with a thickness of 35 μm was formed on both sides of a polyethylene foam (thickness 100 μm). In this way, the substrate-attached double-sided adhesive sheet of Example 5 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film A, which had been punched out in a circular shape with a diameter of 5.8 mm. This obtained the breathable member of Example 5. The ventilation member in Example 5 had the configuration of ventilation member 4B in Figure 2.

[0191] [Example 6] In Example 6, porous film B was used as the porous film. The double-sided adhesive sheet with a substrate from Example 1, which was made using adhesive composition α1, was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film B, which was punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Example 6. The ventilation member of Example 6 had the configuration of ventilation member 4B in Figure 2.

[0192] [Example 7] As the porous film of Example 6, porous film C was used. The double-sided adhesive sheet with a substrate of Example 1, which was made using adhesive composition α1, was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film C, which was punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Example 7. The ventilation member of Example 7 had the configuration of ventilation member 4B in Figure 2.

[0193] [Example 8] As the porous film of Example 6, porous film D was used. The double-sided adhesive sheet with a substrate of Example 1, which was made using adhesive composition α1, was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film D, which was punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Example 8. The ventilation member of Example 8 had the configuration of ventilation member 4B in Figure 2.

[0194] [Comparative Example 1] As the porous film for Comparative Example 1, porous film A was used. To 100 parts by weight of acrylic polymer A4, 30 parts by weight of rosin ester D1 (Harima Chemicals, Haritack PCJ), rosin ester D2 (Harima Chemicals, Haritack SE10), rosin ester D3 (Guangxi Wuzhou Rissei Forestry Chemical Co., Ltd., MHDR), and terpene phenol resin C3 (Arakawa Chemical Industries, Tamanol 803L) were added as tackifiers, along with 1.5 parts by weight (in terms of solid content) of isocyanate crosslinking agent, and the mixture was stirred. This prepared adhesive composition γ1. The isocyanate crosslinking agent was the same as that used in Example 1. Using adhesive composition γ1, an adhesive layer with a thickness of 50 μm was formed on both sides of a polyethylene foam (thickness 100 μm). The rosin ester content in the adhesive layer was at least 0.1% by weight. In this way, a double-sided adhesive sheet with a substrate was obtained for Comparative Example 1. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of a porous film A that had been punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member for Comparative Example 1. The ventilation member for Comparative Example 1 had the configuration of ventilation member 4B in Figure 2.

[0195] [Comparative Example 2] As the porous film for Comparative Example 2, porous film A was used. To 100 parts by weight of acrylic polymer A4, 30 parts by weight of rosin ester D1 (Harima Chemicals, Haritack PCJ) and rosin ester D2 (Harima Chemicals, Haritack SE10) as tackifiers, 25 parts by weight of acrylic oligomer B1, and 1.5 parts by weight (in terms of solid content) of isocyanate crosslinking agent were added and stirred. This prepared adhesive composition γ2. The same isocyanate crosslinking agent used in Example 1 was used. Using adhesive composition γ2, an adhesive layer with a thickness of 50 μm was formed on both sides of a polyethylene foam (thickness 100 μm). The rosin ester content in the adhesive layer was at least 0.1% by weight. In this way, a double-sided adhesive sheet with a substrate of Comparative Example 2 was obtained. This double-sided adhesive sheet was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of a porous film A that had been punched out in a circular shape with a diameter of 5.8 mm. This resulted in the ventilation member of Comparative Example 2. The ventilation member of Comparative Example 2 had the configuration of ventilation member 4B in Figure 2.

[0196] [Comparative Example 3] As the porous film for Comparative Example 3, porous film C was used. The double-sided adhesive sheet with a substrate of Comparative Example 1, which was prepared using adhesive composition γ1, was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film C, which was punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Comparative Example 3. The ventilation member of Comparative Example 3 had the configuration of ventilation member 4B in Figure 2.

[0197] [Comparative Example 4] As the porous film for Comparative Example 4, porous film D was used. The double-sided adhesive sheet with a substrate of Comparative Example 1, which was prepared using adhesive composition γ1, was processed into a ring shape with an outer diameter of 5.8 mm and an inner diameter of 1.6 mm, and bonded to each of the main surfaces of porous film D, which was punched out in a circular shape with a diameter of 5.8 mm. This obtained the ventilation member of Comparative Example 4. The ventilation member of Comparative Example 4 had the configuration of ventilation member 4B in Figure 2.

[0198] Using the method described above, the thickness of the porous film and the thickness of the ventilation members of Examples 1 to 8 and Comparative Examples 1 to 4 were measured. The manufacturing conditions for the ventilation members of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1.

[0199]

[0200] Using the method described above, the air permeability A0 of the porous film in the initial state before the start of the durability test and the air permeability A0 of the porous film 72 hours after the start of the durability test were determined for the breathable members of Examples 1 to 8 and Comparative Examples 1 to 4. 72 , and the air permeability A of the porous film 500 hours after the start of the durability test. 500 The following was measured: Air permeability A 72 and ventilation degree A 500 From, {(Air permeability A 500 - Air permeability A 72 ) / Air permeability A 72 The air permeability reduction rate R, expressed as} × 100, was calculated. The results are shown in Table 2.

[0201]

[0202] Figure 14A shows the results of SEM observation (5000x magnification) of region A in the cross-section of the ventilation member of Example 1 500 hours after the start of the durability test. Figure 14B shows the results of SEM observation (5000x magnification) of region B in the cross-section of the ventilation member of Example 1 500 hours after the start of the durability test. Figure 15A shows the results of SEM observation (5000x magnification) of region A in the cross-section of the ventilation member of Comparative Example 1 500 hours after the start of the durability test. Figure 15B shows the results of SEM observation (5000x magnification) of region B in the cross-section of the ventilation member of Comparative Example 1 500 hours after the start of the durability test. The positions of region A and region B are as shown in Figure 12.

[0203] As can be seen from the results in Table 2, the ventilation members of Examples 1 to 8 had a ventilation rate reduction R of 5% or less, and the decrease in ventilation was suppressed compared to the ventilation members of Comparative Examples 1 to 4.

[0204] Next, using the method described above, the difference (absolute value) between the HSP value of the tackifier contained in the adhesive layer and the HSP value of the thermoplastic resin (PMP, PE, PET, PI) was determined for the breathable members of Examples 1-4, 6-8 and Comparative Examples 1-4. The results are shown in Table 3. All units in Table 3 are (MPa). 0.5 )

[0205]

[0206] As shown in Table 1, the breathable members of Examples 1 to 8 did not contain rosin ester in the adhesive layer. The breathable members of Comparative Examples 1 to 4 contained at least 0.1% by weight of rosin ester in the adhesive layer. As can be seen from the SEM observation images in Figures 14A to 15B, in the breathable member of Example 1, no penetration of the components contained in the tackifier into the porous film was observed in either region A or B after 500 hours from the start of the durability test. In contrast, in the breathable member of Comparative Example 1, penetration of the components contained in the tackifier into the porous film was particularly pronounced in region A, which is closer to the adhesive layer. From these results, it is considered that in the breathable members of Comparative Examples 1 to 4, as time progressed from the start of the durability test, the rosin ester contained in the adhesive layer penetrated in the thickness direction of the porous film.

[0207] From a comparison of Table 2 and Table 3, the difference between the HSP value of the tackifier contained in the adhesive layer and the HSP value of the thermoplastic resin is 8.5 MPa in absolute value. 0.5 It was found that the absence of the following tackifiers tends to suppress the decrease in air permeability. This tendency was particularly pronounced when the thermoplastic resin included at least one selected from the group consisting of polyolefin resins and polyester resins.

[0208] From the above results, it can be understood that the ventilation members of Examples 1 to 8 are suitable for suppressing a decrease in air permeability.

[0209] The technology of the present invention can be applied, for example, to waterproof and breathable membranes, waterproof and sound-permeable membranes, separators for energy storage devices, and the like.

Claims

1. A porous film comprising a thermoplastic resin that does not contain fluorine as its main component, and an adhesive layer bonded to the porous film, wherein the difference between the HSP value of the adhesive layer and the HSP value of the thermoplastic resin is 8.5 MPa in absolute value. 0.5 A breathable material in which the content of a specific component having the following HSP value is less than 0.1% by weight.

2. The breathable member according to claim 1, wherein the adhesive layer comprises at least one selected from the group consisting of terpene-based tackifiers and acrylic oligomers.

3. The breathable member according to claim 1, wherein the adhesive layer comprises a first adhesive layer bonded to a first main surface of the porous film and a second adhesive layer bonded to a second main surface of the porous film.

4. The porous film has a breathable region where the adhesive layer is not bonded, and the area of ​​the breathable region is 40 mm². 2 The ventilation member according to claim 1, which is as follows:

5. The breathable member according to claim 1, wherein the thermoplastic resin comprises at least one selected from the group consisting of polyolefin resin, polyester resin, and polyimide resin.

6. The breathable member according to claim 1, wherein the thermoplastic resin comprises at least one selected from the group consisting of polyolefin resins and polyester resins.

7. The ventilation member according to claim 1, wherein the thermoplastic resin includes a polyolefin resin.

8. The breathable member according to claim 1, wherein the porous film is a stretched film.

9. The ventilation member according to claim 1, further comprising a breathable support material laminated on the porous film.

10. A component supply assembly comprising a ventilation member disposed on the surface of an object having an opening, and a base sheet on which the ventilation member is disposed, wherein the ventilation member is the ventilation member described in claim 1, and the porous film has a shape that covers the opening when disposed on the surface.

Images