JP2021187938A - Double-sided adhesive tape, construction material having tape, and adhesive strength measuring method - Google Patents

Abstract

To provide a double-sided adhesive tape capable of preventing, when adhered onto an adherend (H1) containing a plasticizer and having thickness of 1 mm or more, a deterioration of feeling due to hardening of the adherend (H1) with time, and a curl of the adherend (H1) with time due to progress of the deterioration of feeling, and of suppressing a decrease in an adhesive force with time.SOLUTION: A double-sided adhesive tape includes: a configuration A to be used to bond an adherend containing a plasticizer and having thickness of 1 mm or more, the configuration including an adhesive layer (a1) on one side of a non air-permeable substrate and an adhesive layer (a2) on the other side of the non air-permeable substrate, with thickness of the adhesive layer (a1) within a prescribed range; or a configuration B including an adhesive layer (b1) on one side of an air-permeable substrate and an adhesive layer (b2) on the other side of the air-permeable substrate, with total thickness within a prescribed range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a double-sided adhesive tape that can be used for fixing a member containing a plasticizer. In particular, a plasticizer-containing soft sheet (hereinafter referred to as a plasticizer) having a thickness of 1 mm or more and an appropriate flexibility, which is used as a material for buildings such as houses, buildings, and facilities (hereinafter referred to as a building material). It relates to a double-sided adhesive tape used for fixing the contained soft sheet).

In buildings such as houses, buildings, and facilities, soft sheets containing plasticizers are used for interior materials such as flooring materials and wall materials that create living spaces, interior materials for housing equipment such as kitchens, bathrooms, and toilets, houses, buildings, etc. It is used as a member of various buildings for the purpose of exterior materials for waterproofing.

Conventionally, these plasticizer-containing soft sheets are used by being fixed to various members by an adhesive, heat fusion, screws or the like. However, these fixing methods have a problem that the work is complicated and the application is limited depending on the fixing place.

On the other hand, the fixing method using the double-sided adhesive tape is used as a simple fixing method because it can be fixed without being restricted by the fixing place by attaching the double-sided adhesive tape to the plasticizer-containing soft sheet in advance. However, the plasticizer contained in the plasticizer-containing soft sheet is transferred to the double-sided adhesive tape over time, the adhesive strength originally possessed by the double-sided adhesive tape is significantly reduced, and the plasticizer-containing soft sheet is peeled off. Problems are likely to occur.

In response to the above problems, for example, Patent Document 1 states that even if a vinyl chloride resin base material used for a decorative film or the like is coated or affixed to the substrate, the plasticizer in the vinyl chloride resin causes a decrease in adhesive strength over time. Acrylic adhesives that do not occur are disclosed.

Japanese Unexamined Patent Publication No. 5-043863

By the way, when the plasticizer is transferred from the plasticizer-containing soft sheet to the double-sided adhesive tape attached to the plasticizer-containing soft sheet, not only the adhesive strength of the above-mentioned double-sided adhesive tape is reduced, but also the plasticizer-containing soft sheet is plasticized. Problems occur due to a decrease in the amount of the drug. In particular, when the double-sided adhesive tape is attached to a plasticizer-containing soft sheet having a thickness of 1 mm or more, the present inventors tend to harden the plasticizer-containing soft sheet over time, and the texture is likely to deteriorate, and the texture is further reduced. We have found that there is a problem that the plasticizer-containing soft sheet curls over time.

Further, even in the double-sided adhesive tape using the acrylic pressure-sensitive adhesive disclosed in Patent Document 1, if the plasticizer-containing soft sheet has a thickness of 1 mm or more, an excessive amount of the plasticizer is transferred to the double-sided pressure-sensitive adhesive tape. The adhesive strength of the double-sided adhesive tape may be easily reduced, and there is a problem that the plasticizer-containing soft sheet and other members are easily peeled off over time when they are joined via the double-sided adhesive tape.

The present invention has been made in view of the above problems, and when the plasticizer is attached to an adherend (H1) having a thickness of 1 mm or more, the adherend (H1) becomes hard over time and winds. It prevents the adherend (H1) from curling over time due to a decrease in adhesion and further deterioration in texture, and further, an adhesive force due to excessive transfer of the plasticizer from the adherend (H1). It is an object of the present invention to provide a double-sided adhesive tape capable of suppressing a decrease.

Further, the present invention provides a building material with a tape using the above-mentioned double-sided adhesive tape, and further, the adhesive strength between the adherend (H1) containing a plasticizer and having a thickness of 1 mm or more and the double-sided adhesive tape. It is an object of the present invention to provide a measuring method.

As a result of diligent studies on the above problems, the present inventors have made the thickness of the pressure-sensitive adhesive layer or the total thickness of the double-sided pressure-sensitive adhesive tape according to the specifications of the double-sided adhesive tape in contact with an adherend containing a plasticizer of 1 mm or more. We have found that the above problem can be solved by setting the above range to a predetermined range, and have reached the present invention.

That is, the present invention is used for attaching an adherend containing a plasticizer and having a thickness of 1 mm or more, and has an adhesive layer (a1) on one surface of a non-permeable base material, and the above-mentioned non-permeable group. Configuration A having the pressure-sensitive adhesive layer (a2) on the other surface of the material and the thickness of the pressure-sensitive adhesive layer (a1) being 10 μm or more and 100 μm or less, or the pressure-sensitive adhesive layer on one surface side of the air-permeable substrate. A double-sided pressure-sensitive adhesive tape having (b1), having a pressure-sensitive adhesive layer (b2) on the other surface of the air-permeable base material, and having a structure B having a total thickness of 10 μm or more and 100 μm or less. offer.

The present invention also provides a building material with a tape, to which the above-mentioned double-sided adhesive tape is attached to a building material containing a plasticizer and having a thickness of 1 mm or more.

Further, in the present invention, the double-sided adhesive tape is attached to the adherend surface of an adherend containing a plasticizer and having a thickness of 1 mm or more, and one of the adherend and the double-sided adhesive tape is 90 ° to 180 °. Provided is an adhesive strength measuring method for measuring the adhesive strength of the double-sided adhesive tape to the adherend by tensile peeling at a tensile speed of 10 mm / min or less at a peeling angle.

According to the double-sided adhesive tape of the present invention, when the adhesive is attached to an adherend having a thickness of 1 mm or more containing a plasticizer, the texture of the adherend is deteriorated and curls are generated due to a decrease in the amount of the plasticizer. It is possible to suppress the decrease in adhesive force to the adherend with time due to the excessive transfer of the plasticizer.

It is a schematic sectional drawing which shows an example of the structure A of the double-sided adhesive tape of this invention. It is a schematic sectional drawing which shows an example of the structure B of the double-sided adhesive tape of this invention.

I. Double-sided adhesive tape The double-sided adhesive tape of the present invention is used for attaching an adherend containing a plasticizer and having a thickness of 1 mm or more, and has either the following configuration A or configuration B. That is, the configuration A of the double-sided adhesive tape of the present invention has the pressure-sensitive adhesive layer (a1) on one surface of the non-permeable base material, and the pressure-sensitive adhesive layer (a2) on the other surface of the non-permeable base material. The thickness of the pressure-sensitive adhesive layer (a1) is 10 μm or more and 100 μm or less. Further, the configuration B of the double-sided adhesive tape of the present invention has the pressure-sensitive adhesive layer (b1) on one surface side of the air-permeable base material, and the pressure-sensitive adhesive layer (b2) is provided on the other surface of the air-permeable base material. It has a total thickness of 10 μm or more and 100 μm or less.

In addition, in this specification, an adherend containing a plasticizer and having a thickness of 1 mm or more may be simply referred to as an adherend (H1). Further, another adherend attached to the surface opposite to the surface to which the adherend (H1) of the double-sided adhesive tape is attached may be simply referred to as an adherend (H2).

For example, when a double-sided adhesive tape is attached to an adherend containing a plasticizer (plasticizer-containing adherend) such as a vinyl chloride soft sheet, the plasticizer in the plasticizer-containing adherend becomes the plasticizer-containing adherend over time. It shifts to the double-sided adhesive tape that comes into contact with the plasticizer, and the amount of the plasticizer in the plasticizer-containing adherend is reduced. As a result, the plasticizer-containing adherend becomes hard over time and its texture deteriorates, and as the amount of the plasticizer decreases, it shrinks and curls. Further, when the plasticizer is transferred to the double-sided adhesive tape side, the adhesive strength decreases with time due to the plasticization of the double-sided adhesive tape, and the interface between the double-sided adhesive tape and the plasticizer-containing adherend, or the double-sided adhesive tape At the interface with other adherends bonded to the plasticizer-containing adherend via the double-sided adhesive tape, problems such as easy peeling occur.

The present inventors, etc., these defects are particularly remarkable when the adherend containing the plasticizer has a thickness of 1 mm or more even if the adhesive of the double-sided adhesive tape to be attached to the adherend is appropriately selected. It was found that it is likely to occur in.

As a result of diligent studies by the present inventors on the factors that cause the above-mentioned problems to occur remarkably in an adherend containing a plasticizer and having a thickness of 1 mm or more, the following inferences have been reached. When the adherend containing a plasticizer has a thickness of 1 mm or more, the amount of the plasticizer contained per unit area of the adherend is usually large in order to give a texture or the like. However, when the double-sided adhesive tape is attached to the adherend, the plasticizer in the adherend becomes plastic due to the difference in height between the plasticizer concentration in the adherend and the plasticizer concentration in the double-sided adhesive tape. It becomes easy to move to the double-sided adhesive tape side where the agent concentration is low. Here, the thicker the pressure-sensitive adhesive layer in contact with the adherend, the larger the amount of plasticizer that can be impregnated in the double-sided pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer is more flexible than the adhesive layer. Since the plasticizer is easily transferred, it is estimated that an excessive amount of the plasticizer is transferred from the adherend side to the double-sided adhesive tape side. As described above, due to the relationship between the thickness of the adherend containing the plasticizer and the thickness of the pressure-sensitive adhesive layer in contact with the adherend, an excessive amount of the plasticizer is transferred to the double-sided adhesive tape side, whereby the above-mentioned adhesion is performed. It is presumed that the amount of plasticizer in the body will decrease sharply, and the texture and curl will be more likely to occur. In addition, an excessive amount of plasticizer is transferred to the side of the double-sided adhesive tape and the concentration of the plasticizer in the double-sided adhesive tape becomes high, so that the plasticization of the double-sided adhesive tape is facilitated and the adhesive strength of the adhesive is increased over time. It is estimated that the amount will drop significantly.

Therefore, as a result of further diligent studies by the present inventors, in the case of a plasticizer-containing sheet having a thickness of 1 mm or more, the larger the thickness of the pressure-sensitive adhesive layer in contact with the plasticizer-containing sheet, the more the plasticizer-containing sheet is transferred to the double-sided pressure-sensitive adhesive tape. Although the transfer of the plasticizer is easily promoted, the amount of the plasticizer that can be impregnated in the double-sided adhesive tape is limited by keeping the thickness of the pressure-sensitive adhesive layer substantially in contact with the plasticizer-containing soft sheet within a predetermined range. Therefore, it has been found that the transfer of an excessive amount of the plasticizer to the pressure-sensitive adhesive layer can be suppressed and the above-mentioned problems can be suppressed, and the present invention has been made.

The double-sided adhesive tape of the present invention has a non-permeable base material (k1) or an air-permeable base material (k2) as a core, and the pressure-sensitive adhesive layer (a1) to be attached to an adherend (H1) containing a plasticizer. Or b1) and the adhesive layer (a2 or b2) on the side to be attached to the other adherend (H2) to be bonded to the adherend (H1) are laminated with the base material sandwiched between them. And. That is, when the non-permeable base material (k1) is used for the core, the thickness of the pressure-sensitive adhesive layer (a1) that is substantially in contact with the adherend (H1) is controlled within the range of 10 μm to 100 μm, while the thickness is controlled. When the air-permeable base material (k2) is used for the core, the pressure-sensitive adhesive and the plasticizer constituting the pressure-sensitive adhesive layer can penetrate into the air-permeable base material (k2), so that the adherend (H1) can be used. Provided is a double-sided adhesive tape that controls the thickness of the adhesive layers (total of b1 and b2) on both sides that are substantially in contact with each other, in other words, the total thickness of the double-sided adhesive tape within the range of 10 μm to 100 μm.

Hereinafter, the double-sided adhesive tape of the present invention will be described for each of the configurations A and B.

1. 1. Configuration A
The configuration A of the double-sided adhesive tape of the present invention has the pressure-sensitive adhesive layer (a1) on one surface of the non-permeable base material and the pressure-sensitive adhesive layer (a2) on the other surface of the non-permeable base material. The thickness of the pressure-sensitive adhesive layer (a1) is 10 μm or more and 100 μm or less.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration A of the double-sided adhesive tape of the present invention. As illustrated in FIG. 1, in the double-sided adhesive tape 10A of the configuration A, the adhesive layers (a1) and the adhesive layer (a2) on both sides do not substantially come into contact with each other due to the non-permeable base material (k1). Further, in the double-sided adhesive tape of the configuration A, it is the adhesive layer (a1) that comes into contact with the adherend (H1) having a thickness of 1 mm or more containing the plasticizer.

According to the double-sided adhesive tape of Configuration A, the plasticizer transferred from the adherend (H1) by the impermeable base material (k1) between the adhesive layer (a1) and the adhesive layer (a2) is It cannot pass through the non-permeable substrate (k1) and stays in the pressure-sensitive adhesive layer (a1). Therefore, by setting the thickness of the pressure-sensitive adhesive layer (a1) within a predetermined range, it is possible to suppress an excessive transfer amount of the plasticizer from the adherend (H1) to the pressure-sensitive adhesive layer (a1). Can be done. As a result, it is possible to prevent the texture of the adherend (H1) from being deteriorated and curled due to the decrease in the amount of the plasticizer in the adherend (H1), and to prevent the adherend (H1) from being peeled off due to the decrease in the adhesive force. can. Further, according to the double-sided adhesive tape of the configuration A, the plasticizer transferred from the adherend (H1) by the impermeable base material (k1) between the adhesive layer (a1) and the adhesive layer (a2). It is possible to prevent the agent from migrating to the pressure-sensitive adhesive layer (a2) side. As a result, when the other adherend (H2) is attached to the adhesive layer (a2) side of the double-sided adhesive tape of the configuration A, the other adherend (H2) is made of a material that easily penetrates the plasticizer. Even in certain cases, it is possible to suppress the promotion of the transfer of the plasticizer from the adherend (H1) by the other adherend (H2). As a result, it is possible to suppress a decrease in the texture and curl of the adherend (H1) due to the migration of the plasticizer, and a decrease in the adhesive strength of the double-sided adhesive tape, and the adherend (H1) and other adherends can be suppressed. The peeling of (H2) can be prevented.

<Adhesive layer (a1)>
In the configuration A, the pressure-sensitive adhesive layer (a1) is a layer provided on one surface of a non-permeable substrate. The pressure-sensitive adhesive layer (a1) is bonded to the adherend (H1) containing the plasticizer and having a thickness of 1 mm or more when the double-sided adhesive tape of Configuration A is attached. ..

In the configuration A, the pressure-sensitive adhesive layer (a1) may have a thickness of 10 μm or more and 100 μm or less, preferably 15 μm or more and 63 μm or less, more preferably 20 μm or more and 40 μm or less, and even more preferably 20 μm or more and 30 μm or less. Is. By setting the thickness of the pressure-sensitive adhesive layer (a1) within the above range, when the adherend (H1) is attached to the pressure-sensitive adhesive layer (a1), the adherend (H1) is transferred to the pressure-sensitive adhesive layer (a1). Suppresses the excessive transfer amount of the plasticizer, and reduces the amount of the plasticizer in the adherend (H1) to reduce the texture of the adherend (H1), generate curls, and the pressure-sensitive adhesive layer (a1). ), This is because the effect of suppressing the occurrence of peeling can be further enhanced.

Table In The thickness of the adhesive layer (a1) in the double-sided adhesive tape structure A, refers to the thickness from the contact surface between the impermeable substrate to the surface facing the said contact surface, reference numeral T ₁ of the in Figure 1 Refers to the length of the part to be made.

Further, when the thickness of the adherend (H1) having a thickness of 1 mm or more containing a plasticizer is set to 1, the thickness of the pressure-sensitive adhesive layer (a1) is 1 mm or more. The thickness of (H1) is preferably 0.002 times or more and 0.08 times or less, more preferably 0.004 times or more and 0.08 times or less, and 0.01 times or more and 0.07 times or less. It is more preferable to have. When the thickness of the adherend (H1) having a thickness of 1 mm or more containing the plasticizer and the thickness of the pressure-sensitive adhesive layer (a1) have the above relationship, the plasticizer that can be impregnated in the pressure-sensitive adhesive layer (a1). The amount can be reduced and the plasticization of the double-sided adhesive tape can be suppressed. As a result, while having sufficient adhesive strength with the adherend (H1), the texture of the adherend (H1) is deteriorated and curls are generated due to a decrease in the amount of the plasticizer in the adherend (H1). It can be effectively suppressed.

The pressure-sensitive adhesive layer (a1) preferably has a gel fraction of 1% by mass or more and 35% by mass. As a result, even when the plasticizer in the adherend (H1) is transferred to the pressure-sensitive adhesive layer (a1) when the adherend (H1) is attached to the pressure-sensitive adhesive layer (a1), over time. It is possible to effectively prevent the occurrence of peeling. Above all, the gel content of the pressure-sensitive adhesive layer (a1) is preferably 1% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 25% by mass or less, and 1% by mass or more and 15% by mass or less. This is more preferable in order to effectively prevent the occurrence of peeling over time even when the plasticizer is transferred to the pressure-sensitive adhesive layer (a1).

In the present specification, the gel fraction of the pressure-sensitive adhesive layer (a1) is composed of a pressure-sensitive adhesive layer (a1) excluding the pressure-sensitive adhesive layer (a2) of the double-sided pressure-sensitive adhesive tape of composition A and a non-permeable substrate. Using the test piece, the test piece whose mass of the pressure-sensitive adhesive layer (a1) was measured in advance was immersed in a mixed solvent of 70 parts by mass of toluene and 30 parts by mass of methanol adjusted to 23 ° C. for 72 hours, and then an ultrasonic device was used. After vibrating at a frequency of 40 kHz for 15 minutes in an atmosphere of 23 ° C., the weight of the adhesive layer (a1) remaining in the mixed solvent after drying was measured and calculated based on the following formula. Point to the value.

Gel fraction (% by mass) = {(mass of the pressure-sensitive adhesive layer (a) remaining in the mixed solvent) / (mass of the pressure-sensitive adhesive layer (a) before immersion)} × 100

The mass of the pressure-sensitive adhesive layer (a1) before immersion is a value obtained by subtracting the mass of the non-permeable base material from the mass of the test piece, in other words, the mass of the double-sided pressure-sensitive adhesive tape, and the non-permeable material used for its production. It refers to the value obtained by subtracting the mass of the base material and the mass of the pressure-sensitive adhesive layer (a2). Further, the mass of the remaining pressure-sensitive adhesive layer refers to a value obtained by subtracting the mass of the non-permeable substrate from the mass of the residue after drying. The test piece may be obtained by wiping off the pressure-sensitive adhesive layer (a2) from the double-sided pressure-sensitive adhesive tape of Configuration A with alcohol or the like, and the pressure-sensitive adhesive may be applied to one side of a non-permeable base material whose mass has been measured in advance. A predetermined amount of the pressure-sensitive adhesive constituting the layer (a1) may be applied.

The gel fraction calculated by using the mixed solvent and applying ultrasonic vibration does not correlate with the gel fraction with respect to the solvent of toluene alone, but the intermolecular and intramolecular hydrogen of the pressure-sensitive adhesive layer. It breaks the apparent bond due to binding, etc., and refers to the gel fraction caused by the cross-linking reaction of a cross-linking agent or the like.

The basis weight of the adhesive layer (a1) ^may be in the range of ^{10g / m 2 ~110g / m 2} , preferably in the range of ^{15g / m 2 ~73g / m 2} , more preferably 20g / ^m 2 in the range of to 50 g / ^{m 2,} more preferably in the range of ^{20 g} / m 2 to 40 g / ^{m 2.} By setting the basis weight of the pressure-sensitive adhesive layer (a1) within the above range, it is possible to have sufficient adhesive strength with the adherend (H1), and at the same time, the plasticizer in the adherend (H1). This is because it is possible to effectively suppress the decrease in the texture and curl of the adherend (H1) due to the decrease in the amount, and the decrease in the adhesive force with time due to the plasticization of the double-sided adhesive tape.

In the present specification, the basis weight of the pressure-sensitive adhesive layer (a1) represents the mass of the pressure-sensitive adhesive layer (a1) existing per ^{unit area (1 m 2) of the double-sided adhesive tape, and is based on the following formula.} The calculated value is shown.

Basis weight (g / m ² ) of the pressure-sensitive adhesive layer (a1) = (mass of the pressure-sensitive adhesive layer (a1)) / (area on one side of the double-sided adhesive tape of structure A)

The pressure-sensitive adhesive layer (a1) preferably has a storage elastic modulus in the range of 0.08 MPa to 0.12 MPa at 23 ° C. measured by a dynamic viscoelastic spectrum measured at a frequency of 1 Hz. When it is in the range of 08 MPa to 0.09 MPa, it is possible to impart excellent adhesive force at the initial stage of application to the adherend (H1), and it is possible to suppress a decrease in adhesive force with time due to migration of the plasticizer. It is more preferable to be able to do it.

Further, in the pressure-sensitive adhesive layer (a1), the ratio (tan δ) of the loss elasticity to the storage elasticity at 60 ° C. measured by the dynamic viscoelastic spectrum measured at a frequency of 1 Hz is 0.40 to 0.60. It is preferably within the range, and it is preferably within the range of 0.45 to 0.50 when the double-sided adhesive tape of Configuration A attached to the adherend (H1) is left in an environment of 60 ° C. The plasticizer that can migrate from the adherend (H1) over time is not unevenly distributed at the adhesive interface between the adherend (H1) and the pressure-sensitive adhesive layer (a1), and has excellent adhesive strength and cohesive strength over a long period of time. Double-sided adhesive tape is more preferred in that it can be retained.

Further, the pressure-sensitive adhesive layer (a1) has a ratio of loss elasticity (tan δ) to storage elasticity at 100 ° C. measured by a dynamic viscoelastic spectrum measured at a frequency of 1 Hz of 0.55 to 0.80. It is preferably within the range, and it is preferably within the range of 0.60 to 0.70 when the double-sided adhesive tape of the above configuration A attached to the adherend (H1) is left in an environment of 100 ° C. In addition, the plasticizer that can migrate from the adherend (H1) over time is not unevenly distributed at the adhesive interface between the adherend (H1) and the pressure-sensitive adhesive layer (a1), and has excellent adhesive strength and cohesive strength over a long period of time. It is more preferable in that it can be a double-sided adhesive tape that holds the above.

The ratio of the loss elastic modulus (tan δ) at each temperature refers to a value calculated based on the formula of tan δ = loss elastic modulus (Pa) / storage elastic modulus (Pa).

In the present specification, the storage elastic modulus of the pressure-sensitive adhesive layer (a1) at 23 ° C. and tan δ at 60 ° C. and 100 ° C. are referred to as viscoelasticity testers (manufactured by TA Instruments Japan, trade name: Using ARES-G2), the test piece was sandwiched between parallel disks, which are the measuring parts of the testing machine, and the storage elastic modulus measured at a frequency of 1 Hz under the temperature conditions of 23 ° C, 60 ° C or 100 ° C, and the storage elastic modulus. , Refers to the value calculated based on the above-mentioned storage elastic modulus and loss elastic modulus. As the test piece, a pressure-sensitive adhesive layer (a1) cut into a circle having a thickness of 2 mm and a diameter of 8 mm is used.

The double-sided adhesive tape of Configuration A having the storage elastic modulus at 23 ° C. within the above range and the pressure-sensitive adhesive layer (a1) having tan δ at 60 ° C. and 100 ° C. is caused by the repulsive force of the adherend (H1) and the like. The adherend (H1) caused by the transfer of the plasticizer from the adherend (H1) to the adhesive layer (a1) even when it is left in an environment of 100 ° C. or lower because it does not easily cause peeling. It is possible to effectively suppress the interface peeling between the adhesive layer (a1) and the pressure-sensitive adhesive layer (a1).

The pressure-sensitive adhesive layer (a1) can be formed by, for example, a pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, synthetic rubber-based pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and the like. Among them, the versatility is high, the double-sided adhesive tape can be manufactured at a relatively low cost, and the effect of the present invention by controlling the thickness of the adhesive layer (a1) with respect to the adherend (H1) is particularly easy to be exerted. It is preferable to use an acrylic pressure-sensitive adhesive.

As the acrylic pressure-sensitive adhesive, an acrylic polymer and, if necessary, a cross-linking agent, a tack-imparting resin and the like can be used, and among them, an acrylic polymer, a cross-linking agent and a tack-imparting resin are contained. It is preferable to use an acrylic pressure-sensitive adhesive to obtain a double-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer having excellent weather resistance and heat resistance.

In other words, the pressure-sensitive adhesive layer (a1) preferably contains an acrylic polymer, a cross-linking agent, and a tack-imparting resin, and the acrylic polymer is cross-linked in the pressure-sensitive adhesive layer (a1). Is preferable.

As the acrylic polymer, one obtained by polymerizing one or more kinds of monomer components including (meth) acrylic monomer and the like can be used. The acrylic polymer may be a homopolymer of one kind of monomer, or may be an acrylic copolymer obtained by polymerizing a combination of two or more kinds of monomers. Among them, an acrylic copolymer obtained by polymerizing one or more kinds of (meth) acrylic monomers in combination with one or more kinds of monomers other than the (meth) acrylic monomers is preferable.

Examples of the (meth) acrylic monomer include alkyl (meth) acrylates, and specifically, methyl (meth) acrylates, ethyl (meth) acrylates, n-butyl (meth) acrylates, and isobutyl (meth) acrylates. , T-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate (Meta) acrylate having an alkyl group having 1 to 14 carbon atoms can be used, and it is preferable to use (meth) acrylate having an alkyl group having 4 to 9 carbon atoms, and n-butyl acrylate is preferable. It is more preferable to use or 2-ethylhexyl acrylate alone or in combination.

The (meth) acrylic monomer is preferably used in the range of 80% by mass to 98.5% by mass, and 90% by mass to 98% by mass, based on the total amount of the monomer components constituting the acrylic polymer. It is more preferable to use it in the range of 5.5% by mass. In addition, even after the plasticizer has been transferred from the adherend (H1) to the adhesive layer (a1) over time, it has become familiar with the surface of the adherend (H1) from the initial stage of application and exhibits excellent adhesive strength. In order to obtain a double-sided adhesive tape in which the plasticizer is not unevenly distributed at the interface between the adherend (H1) and the adhesive layer (a1) and retains excellent adhesive strength and cohesive strength for a long period of time, the three-dimensional alkyl group described above can be obtained. It is preferable to use 60% by mass or more of n-butyl acrylate having 4 carbon atoms, which is less affected by damage, more preferably 80% by mass or more, and further preferably 90% by mass or more.

Further, as the acrylic polymer, it is preferable to use a highly polar monomer such as a highly polar vinyl monomer in addition to the above-mentioned (meth) acrylic monomer. That is, the pressure-sensitive adhesive layer (a1) preferably contains at least an acrylic copolymer having a structure (constituent unit) derived from the (meth) acrylic monomer and a structure (constituent unit) derived from the highly polar vinyl monomer. ..

As the highly polar vinyl monomer, for example, a hydroxyl group-containing vinyl monomer, a carboxyl group-containing vinyl monomer, a nitrogen-containing vinyl monomer having an amino group or an amide group, or the like may be used alone or in combination of two or more. Can be done.

The hydroxyl group-containing vinyl monomer can react with a cross-linking agent described later by the hydroxyl group. Examples of the hydroxyl group-containing vinyl monomer include hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate. (Meta) acrylic monomer having (meth) acrylic monomer can be mentioned.

The hydroxyl group-containing vinyl monomer is preferably used in the range of 0.05% by mass to 2.0% by mass, and 0.1% by mass to 0, based on the total amount of the monomer components constituting the acrylic polymer. It is more preferable to use it in the range of .5% by mass, and the range of 0.1% by mass to 0.2% by mass makes it easy to adjust the gel fraction of the pressure-sensitive adhesive layer (a1) to the above range. As a result, it adapts to the surface of the adherend (H1) from the initial stage of application, exhibits excellent adhesive strength, and when the plasticizer is transferred from the adherend (H1) to the pressure-sensitive adhesive layer over time, between the acrylic polymers. The cross-linked structure of the plasticizer does not hinder the fluidity of the plasticizer and can suppress the uneven distribution of the plasticizer at the adhesive interface with the adherend (H1). Adhesive tape can be obtained.

Examples of the nitrogen-containing vinyl monomer include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, acryloylmorpholine, dimethylaminoethylacrylate, N, N-dimethylacrylamide, N-isopropylacrylamide and the like.

The nitrogen-containing vinyl monomer is preferably in the range of 0.5% by mass to 20% by mass, and 0.8% by mass to 10% by mass, based on the total amount of the monomer components constituting the acrylic polymer. It is more preferably in the range of% by mass, and even more preferably in the range of 1.0% by mass to 2.5% by mass. Most preferably, it is in the range of 1.0% by mass to 1.9% by mass. By adjusting the structural ratio derived from the nitrogen-containing vinyl monomer constituting the acrylic polymer to the above range, the acrylic pressure-sensitive adhesive layer is appropriately softened, and from the initial stage of application to the surface of the adherend (H1). It is familiar and exhibits excellent adhesive strength, and even after the plasticizer is transferred from the adherend (H1) to the adhesive layer over time, the plasticizer is not unevenly distributed on the adhesive interface with the adherend (H1). It is possible to obtain a double-sided adhesive tape that retains excellent adhesive strength and cohesive strength for a long period of time.

Examples of the carboxyl group-containing vinyl monomer include carboxyl group-containing (meth) acrylics such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, (meth) acrylic acid dimer, crotonic acid, and ethylene oxide-modified amber acid acrylate. Examples include monomers. Of these, acrylic acid is preferable.

The carboxyl group-containing vinyl monomer is preferably used in the range of 0.2% by mass to 5% by mass, preferably 0.4% by mass, based on the total amount of the monomer components constituting the acrylic polymer. It is more preferable to use it in the range of ~ 3% by mass. Most preferably, it is used in the range of 1.5% by mass to 2.5% by mass. When the amount of the carboxyl group-containing vinyl monomer used is within the above range, excellent adhesive strength can be exhibited from the initial stage of application to a highly polar adherend (H1) such as a polyvinyl chloride resin. Further, since the carboxyl group is highly polar, if a large amount is present in the pressure-sensitive adhesive layer (a1), the pressure-sensitive adhesive layer (a1) is likely to be plasticized by the plasticizer transferred from the adherend (H1). There is. Therefore, when the carboxyl group-containing vinyl monomer is used within the range of the content shown above, the transfer of the plasticizer to the pressure-sensitive adhesive layer (a1) and the like is suppressed, and adhesion due to the influence of the plasticizer is suppressed. It is preferable because the decrease in force is small and the excellent adhesive force and cohesive force are maintained for a long period of time.

Examples of the highly polar vinyl monomer include vinyl acetate, a sulfonic acid group-containing monomer such as 2-acrylamide-2-methylpropanesulfonic acid, 2-methoxyethyl (meth) acrylate, and 2-. Other highly polar vinyl monomers such as terminal alkoxy-modified (meth) acrylates such as phenoxyethyl (meth) acrylates can be used.

The other highly polar vinyl monomer is preferably used in the range of 0.2% by mass to 5% by mass, and 0.4% by mass to 5% by mass, based on the total amount of the monomer components constituting the acrylic polymer. It is more preferable to use it within the range of 3% by mass. Most preferably, it is used in the range of 2.0% by mass to 3.0% by mass. When the amount of the other highly polar vinyl monomer used is within the above range, the adhesive force to the surface of a highly polar adherend (H1) such as a polyvinyl chloride resin is increased from the initial stage of application, and the above carboxyl group is used. Since it does not have as much polarity as the vinyl monomer having, it is difficult for the plasticizer to penetrate between the molecules of the acrylic polymer, and after the plasticizer is transferred from the adherend (H1) to the pressure-sensitive adhesive layer over time. However, it is possible to obtain a double-sided adhesive tape that retains excellent adhesive strength and cohesive strength for a long period of time.

The acrylic pressure-sensitive adhesive preferably contains an acrylic copolymer having a structure (constituent unit) derived from a carboxyl group-containing vinyl monomer. In other words, the acrylic copolymer contained in the acrylic pressure-sensitive adhesive preferably contains a carboxyl group-containing vinyl monomer as a monomer unit (monomer component) constituting the acrylic copolymer. Adhesion to a highly polar adherend (H1) such as polyvinyl chloride resin is good, deterioration of adhesive force due to the influence of the above plasticizer can be suppressed, and excellent adhesive force and cohesive force are maintained for a long period of time. Because it can be done.

Further, the acrylic pressure-sensitive adhesive preferably contains an acrylic copolymer having a structure (constituent unit) derived from a nitrogen-containing vinyl monomer. In other words, the acrylic copolymer contained in the acrylic pressure-sensitive adhesive preferably contains a nitrogen-containing vinyl monomer as a monomer unit (monomer component) constituting the acrylic copolymer. When the adherend (H1) is, for example, highly polar polyvinyl chloride, a plasticizer that easily penetrates between the molecules of the polyvinyl chloride is used in order to more effectively plasticize the polyvinyl chloride. Often. Examples of the plasticizer include those having an aromatic ring and an ester group in the molecule. A plasticizer having a structure that easily polarizes between the aromatic ring and an ester group or the like easily penetrates between the molecules of the polyvinyl chloride. Here, when the acrylic polymer in the pressure-sensitive adhesive layer (a1) has a carboxyl group, the carboxyl group has an extremely high polarity like the polyvinyl chloride, so that the plasticizer is contained in the pressure-sensitive adhesive layer. It becomes easy to penetrate into the molecule of the contained acrylic polymer. As a result, the amount of the plasticizer in the adherend (H1) is reduced, the texture and the like are impaired, and the adhesive layer is plasticized, so that the adhesive strength tends to decrease. On the other hand, by containing a nitrogen-containing vinyl monomer as a monomer component constituting the acrylic polymer, the polarity of the pressure-sensitive adhesive layer (a1) is lowered and the amount of the plasticizer from the adherend (H1) is excessive. It is possible to suppress the transition. As a result, it is possible to prevent the texture of the adherend (H1) from being deteriorated and curl, and the plasticizing of the pressure-sensitive adhesive layer (a1) by the plasticizer transferred from the adherend (H1) is more effective. The pressure-sensitive adhesive layer (a1) can maintain excellent adhesive strength for a long period of time.

In the acrylic polymer in the pressure-sensitive adhesive layer (a1), at least one of the carboxyl group-containing vinyl monomer and the nitrogen-containing vinyl monomer is used as a monomer unit (single amount) constituting the acrylic copolymer for the above-mentioned reason. It is preferable to have it in the body component). Above all, although the pressure-sensitive adhesive layer (a1) is thin, it exhibits good adhesion to a highly polar adherend (H1), and the plasticizer from the adherend (h1) to the pressure-sensitive adhesive layer (a1). It is more preferable to have both the carboxyl group-containing vinyl monomer and the nitrogen-containing vinyl monomer in the monomer unit (monomer component) constituting the acrylic copolymer because excessive migration can be suppressed.

The acrylic polymer can be produced by polymerizing the monomer component by a known method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method, and is produced by a solution polymerization method. It is preferable to improve the production efficiency of the double-sided adhesive tape and to reduce the production cost thereof.

The acrylic polymer preferably has a weight average molecular weight in the range of 300,000 to 1.5 million, and preferably has a weight average molecular weight in the range of 500,000 to 1,000,000.

In addition, in this specification, the said weight average molecular weight can be measured by a gel permeation chromatograph (GPC). More specifically, it can be obtained by measuring with the following GPC measuring conditions by the polystyrene conversion value using "SC8020" manufactured by Tosoh Corporation as a GPC measuring device.
(GPC measurement conditions)
-Sample concentration: 0.5% by mass (tetrahydrofuran solution)
-Sample injection amount: 100 μL
-Eluent: Tetrahydrofuran (THF)
・ Flow velocity: 1.0 mL / min
-Column temperature (measurement temperature): 40 ° C
-Column: "TSKgel GMHR-H" manufactured by Tosoh Corporation
・ Detector: Differential refractometer

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (a1) preferably contains a cross-linking agent in addition to the above-mentioned acrylic polymer. By forming the pressure-sensitive adhesive layer (a1) with the pressure-sensitive adhesive containing the cross-linking agent, the adhesive strength to the surface of the adherend (H1) is excellent from the initial stage of application, and the pressure-sensitive adhesive is attached to the adherend (H1) over time. Even after the plasticizer is transferred to the layer (a1), excellent adhesive strength and cohesive strength can be maintained for a long period of time.

As the cross-linking agent, for example, an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, a chelate-based cross-linking agent, an aziridine-based cross-linking agent, an oxazoline-based cross-linking agent and the like are used depending on the type of the cross-linking functional group of the acrylic polymer. Can be selected and used. The content of the cross-linking agent is preferably in the range of 0.3 parts by mass to 1.8 parts by mass, and in the range of 0.6 parts by mass to 1.3 parts by mass with respect to 100 parts by mass of the acrylic polymer. Is more preferable, and the range of 0.6 parts by mass to 0.9 parts by mass is most preferable. The content of the cross-linking agent can be appropriately selected and used so as to form the pressure-sensitive adhesive layer (a1) having the gel fraction described above.

The pressure-sensitive adhesive may contain a tack-imparting resin in order to further improve the adhesive strength of the double-sided pressure-sensitive adhesive tape. As the tackifying resin, rosin-based resin, terpene-based resin, petroleum resin such as aliphatic (C5 series) and aromatic (C9 series), styrene resin phenol resin, xylene resin, methacrylic resin and the like are used. can do. Among them, as the tackifier resin, it is preferable to use a rosin-based resin, and it is preferable to use a polymerized rosin-based resin. This is because the strength of the pressure-sensitive adhesive layer capable of resisting the force that the adherend (H1) such as the plasticizer-containing soft sheet tends to curl is developed, and peeling can be suppressed.

The tackifier resin is preferably used in the range of 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the acrylic polymer, and is preferably used in the range of 10 parts by mass to 30 parts by mass. It is more preferable because it can impart an excellent adhesive force at the initial stage of application to the body (H1) and can suppress a decrease in the adhesive force with time due to the transfer of the plasticizer.

<Non-breathable substrate>
In the configuration A, the non-permeable base material is a layer provided between the pressure-sensitive adhesive layer (a1) and the pressure-sensitive adhesive layer (a2) as the core of the double-sided adhesive tape. In the configuration A, since the pressure-sensitive adhesive layers (a1) and (a2) are formed on both sides of the non-permeable base material, the pressure-sensitive adhesive layer (a1) and the pressure-sensitive adhesive layer (a2) are substantially in contact with each other. There is nothing to do.

As the non-permeable substrate, one having a low affinity with a plasticizer and not permeated or impregnated with the pressure-sensitive adhesives of the pressure-sensitive adhesive layers (a1) and (a1) is used.

The non-breathable base material is a test piece obtained by laminating 10 non-breathable base materials, and the Gale-type air permeability measured according to JISP 8117 of the above test piece is larger than 10 seconds / 100 ml. It is preferably 60 seconds / 100 ml or more, and more preferably 60 minutes / 100 ml or more. This is because the non-permeable base material can prevent the plasticizer from migrating to the pressure-sensitive adhesive layer (a2) side by exhibiting the above-mentioned air permeability. The higher the Gale-type air permeability of the non-breathable substrate, the better, and the upper limit is not particularly limited, but the measurement limit time / 100 ml can be set, and for example, it can be set to less than 10,000 seconds / 100 ml.

The Gale-type air permeability of a non-permeable substrate is a permeability measured in accordance with JIS P8117 by stacking 10 non-permeable substrates and using the 10-layer substrate as a test piece. The measurement was performed when 10 non-permeable substrates were stacked and set in 50% RH at 23 ° C, and the time required for an inner cylinder having an inner diameter of 28.6 mm and a weight of 567 g to fall and 100 ml of air to pass through was measured. Measure the transit time of.

As the non-permeable substrate, a resin film, a resin foam, a high-density non-woven fabric or the like capable of exhibiting the above-mentioned air permeability can be used. Examples of the resin film include polyester films such as polyethylene terephthalate (PET) and polyolefin films such as polyethylene (PE) and polypropylene (PP).

Further, when stickability to a rough surface is required, a resin foam can be preferably used as the non-permeable base material. Examples of the resin foam include foams obtained by foaming a resin such as PE or PP. The resin foam may have a closed cell structure or an open cell structure, but is preferably a closed cell structure from the viewpoint of non-breathability.

If the double-sided adhesive tape needs to be cut by hand, the non-permeable base material includes a biaxially stretched film such as PP, PET, polystyrene (PS), and nylon, and a laterally uniaxially stretched film such as PE and PP. , A non-stretched film such as linear low density polyethylene (LLDPE), a resin film containing a fragile portion due to uneven processing, a film having a metal foil or a metal vapor deposited on it, and a film containing a barrier coat layer are preferably used. Specifically, Trefan YT42, Trefan YT62 (all manufactured by Toray Co., Ltd.), Tiafine TF110, Tiafine TF120 (all by Toyo Spinning Co., Ltd.), OPS film (Asahi Kasei Chemicals Co., Ltd.), Karariyan Y, Karariyan Y2 (all are manufactured by Toray Co., Ltd.) All of them include (Electrical Chemical Industry Co., Ltd.), LL-MTNST (Futamura Chemical Co., Ltd.) and the like.

The non-permeable substrate preferably does not contain a plasticizer from the viewpoint of transferability of the plasticizer. In the present specification, the fact that the base material does not contain a plasticizer means that the base material does not contain the plasticizer substantially or completely, and specifically, the content of the plasticizer in the base material is. It is less than 10% by mass, preferably 5% by mass or less, and more preferably 1% by mass or less. The base material is a general term for a non-permeable base material and an air permeable base material.

The thickness of the non-permeable substrate is not particularly limited as long as it can exhibit the above-mentioned air permeability and can support the pressure-sensitive adhesive layers (a1) and (a2), but is not particularly limited, for example, 2 μm. The range of ~ 1500 μm is preferable, and the range of 5 μm to 110 μm is preferable, and further 10 μm to 20 μm from the viewpoint of preventing the migration of the plasticizer, making the double-sided adhesive tape thinner, and making it easier to handle. It is preferably within the range of. When the non-permeable substrate is a foamed resin body, the thickness is preferably 100 μm or more, preferably 200 μm or more, from the viewpoint of preventing the migration of the plasticizer and improving the adhesiveness to the rough surface. More preferred.

<Adhesive layer (a2)>
In the configuration A, the pressure-sensitive adhesive layer (a2) is a layer provided on the surface opposite to the surface having the pressure-sensitive adhesive layer (a1) of the non-permeable substrate. The pressure-sensitive adhesive layer (a2) is attached to the other adherend (H2) when the adherend (H1) and the other adherend (H2) are joined via the double-sided adhesive tape of the configuration A. Will be combined.

In the configuration A, the thickness of the pressure-sensitive adhesive layer (a2) is not particularly limited as long as it can exhibit sufficient adhesive force to the adherend (H2), but is 10 μm or more and 100 μm or less. Can be done. Above all, the thickness of the pressure-sensitive adhesive layer (a2) is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 63 μm or less, more preferably 20 μm or more and 40 μm or less, and further preferably 20 μm or more and 30 μm or less. Similar to the pressure-sensitive adhesive layer (a1), the pressure-sensitive adhesive layer (a2) also has a predetermined thickness, so that another adherend (H2) attached to the pressure-sensitive adhesive layer (a2) contains a plasticizer and When the thickness is 1 mm or more, the plasticizer contained in the other adherend (H2) is transferred to the pressure-sensitive adhesive layer (a2), so that the texture of the other adherend (H2) is deteriorated. It is possible to suppress the generation of curl and the decrease in adhesive strength. This is because the deterioration of the adherend (H2) can be prevented, the interface peeling between the pressure-sensitive adhesive layer (a2) and the other adherend (H2) can be prevented, and the adhesive layer (H2) can be firmly bonded. ..

Further, when the other adherend (H2) is an adherend containing a plasticizer and having a thickness of 1 mm or more, the thickness of the other adherend (H2) to be attached to the pressure-sensitive adhesive layer (a2). When is 1, the thickness of the pressure-sensitive adhesive layer (a2) is preferably 0.002 times or more and 0.08 times or less, and 0.004 times or more and 0. It is more preferably 08 times or less, and more preferably 0.01 times or more and 0.07 times or less. This is because the thickness of the other adherend (H2) and the thickness of the pressure-sensitive adhesive layer (a2) have the above-mentioned relationship, so that the adhesiveness to the adherend (H2) can be easily ensured.

The pressure-sensitive adhesive layer (a2) may have the same composition as the pressure-sensitive adhesive layer (a1) or may have a different composition.

The pressure-sensitive adhesive layer (a2) can be formed by using, for example, an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or the like. Of these, an acrylic pressure-sensitive adhesive is preferable. The double-sided adhesive tape of configuration A can be manufactured at low cost, and the thickness of the adhesive layer (a2) is adjusted when the other adherend (H2) attached to the adhesive layer (a2) contains a plasticizer. By doing so, it is possible to suppress the deterioration of the texture and curl of the other adherend (H2) due to the migration of the plasticizer, the decrease of the adhesive force, and the peeling of the other adherend (H2). Because it becomes.

When the pressure-sensitive adhesive layer (a1) and the pressure-sensitive adhesive layer (a2) are each formed of an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive layer (a2) is an acrylic pressure-sensitive adhesive having the same composition as the pressure-sensitive adhesive layer (a1). It may be formed of an acrylic pressure-sensitive adhesive having a different composition. As the acrylic pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (a2), an acrylic polymer and, if necessary, a cross-linking agent, a tack-imparting resin and the like can be used, and the acrylic polymer and the cross-linking agent can be used. It is preferable to use an acrylic pressure-sensitive adhesive containing the pressure-sensitive adhesive and the pressure-sensitive adhesive resin in terms of excellent weather resistance and heat resistance. The details of the acrylic polymer, the cross-linking agent, and the tack-imparting resin contained in the acrylic pressure-sensitive adhesive are the same as the details of the acrylic polymer, the cross-linking agent, and the tack-imparting resin described in the above-mentioned pressure-sensitive adhesive layer (a1). Therefore, the description here is omitted.

The acrylic polymer in the pressure-sensitive adhesive layer (a2) has at least one of a carboxyl group-containing vinyl monomer and a nitrogen-containing vinyl monomer in a monomer unit (monomer component) constituting the acrylic copolymer. It is more preferable, and it is more preferable to have both the carboxyl group-containing vinyl monomer and the nitrogen-containing vinyl monomer in the monomer unit (monomer component) constituting the acrylic copolymer. The reason is as described in the pressure-sensitive adhesive layer (a1).

The gel fraction of the pressure-sensitive adhesive layer (a2) is not particularly limited, but is preferably 1% by mass or more and 35% by mass, more preferably 1% by mass or more and 25% by mass or less, and 1% by mass or more. It is more preferable that it is 15% by mass or less. When the adherend (H2) attached to the pressure-sensitive adhesive layer (a2) is an article containing a plasticizer and having a thickness of 1 mm or more, the plasticizer in the adherend (H2) is the pressure-sensitive adhesive layer (a2). ), It is possible to effectively prevent the occurrence of peeling over time.

In the present specification, the gel fraction of the pressure-sensitive adhesive layer (a2) is the gel content of the pressure-sensitive adhesive layer (a1) described above using a test piece composed of the pressure-sensitive adhesive layer (a2) and a non-permeable substrate. It can be measured by the same method as the rate measuring method.

The basis weight of the adhesive layer (a2) is not particularly ^limited, may be in the range of ^{10g / m 2 ~110g / m 2} , preferably in the range of ^15g / ^{m 2 ~73g} / m 2 , more preferably in the range of ^{20g / m 2 ~50g / m 2} , more preferably in the range of ^{20g / m 2 ~40g / m 2} . By setting the basis weight of the pressure-sensitive adhesive layer (a2) within the above range, it is possible to have sufficient adhesive strength with the adherend (H2), and the adherend (H2) has a thickness of 1 mm or more. In the case of an article containing a plasticizer having the above, it is possible to effectively suppress a decrease in the texture of the adherend (H2) and the generation of curl due to a decrease in the amount of the plasticizer in the adherend (H2).

In the present specification, the basis weight of the pressure-sensitive adhesive layer (a2) represents the mass of the pressure-sensitive adhesive layer (a2) existing per ^{unit area (1 m 2) of the double-sided adhesive tape, and is based on the following formula.} The calculated value is shown.

Basis weight (g / m ² ) of the pressure-sensitive adhesive layer (a2) = (mass of the pressure-sensitive adhesive layer (a2)) / (area on one side of the double-sided adhesive tape of structure A)

The ratio of the storage elastic modulus at 23 ° C. and the loss elastic modulus to the storage elastic modulus at the respective temperatures of 60 ° C. and 100 ° C. as measured by the dynamic elastic modulus of the pressure-sensitive adhesive layer (a2) measured at a frequency of 1 Hz. (Tanδ) is the same as the preferable range of the storage elastic modulus of the pressure-sensitive adhesive layer (a1) at 23 ° C. and the ratio of the loss elastic modulus to the storage elastic modulus at each temperature of 60 ° C. and 100 ° C. (tanδ). Can be.

The storage elastic modulus of the pressure-sensitive adhesive layer (a2) at 23 ° C. and the ratio of the loss elastic modulus to the storage elastic modulus at each of the temperatures of 60 ° C. and 100 ° C. (tan δ) are described in the above-mentioned section of the pressure-sensitive adhesive layer (a1). It can be measured by the method described in.

<Release liner>
In the double-sided adhesive tape of the configuration A, a release liner may be laminated on the surfaces of the pressure-sensitive adhesive layer (a1) and the pressure-sensitive adhesive layer (a2) opposite to the non-permeable base material side. Examples of the release liner include papers such as kraft paper, glassin paper and high-quality paper, resin films such as polyethylene and polypropylene (oriented polypropylene (OPP), cast polypropylene (CPP) and polyethylene terephthalate, and the papers and resins. It is possible to use a laminated paper on which a film is laminated, a paper obtained by sealing the above papers with clay or polyvinyl alcohol, or the like, which has one or both sides peeled off with a silicone resin or the like.

<Manufacturing method of double-sided adhesive tape of configuration A>
The double-sided adhesive tape having the configuration A is a step of forming the adhesive layer (a1) and the adhesive layer (a2), respectively, by applying the adhesive to the surface of the release liner and drying the tape, respectively. The pressure-sensitive adhesive layers (a1) and (a2) formed above can be produced by undergoing a step of transferring them to both sides of a non-permeable base material, respectively.

2. 2. Configuration B
The configuration B of the double-sided adhesive tape of the present invention has the pressure-sensitive adhesive layer (b1) on one side of the air-permeable base material, and has the pressure-sensitive adhesive layer (b2) on the other side of the air-permeable base material. The total thickness is 10 μm or more and 100 μm or less.

In the double-sided adhesive tape of configuration B, the pressure-sensitive adhesive layer (b1) and a part or all of the pressure-sensitive adhesive layer (b2) are usually impregnated with an air-permeable base material. FIG. 2 is a schematic cross-sectional view showing an example of the double-sided adhesive tape 10B of the configuration B, in which a part of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is impregnated into the air-permeable base material (k2), respectively. An example is shown.

In the double-sided adhesive tape of configuration B, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive are formed by impregnating a part or all of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) with the air-permeable base material (k2). It can be simulated that the layer (b2) is integrated. Therefore, what is substantially in contact with the adherend (H1) is the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) containing the air-permeable base material (k2), that is, the entire double-sided pressure-sensitive adhesive tape of composition B. Become. Therefore, when the plasticizer is attached to an adherend (H1) having a thickness of 1 mm or more, the adhesive layer (b1) of the double-sided adhesive tape of the configuration B and the adherend (H1) come into contact with each other. Also, the pressure-sensitive adhesive layer (b2) may come into contact with the adherend (H1).

Since the double-sided adhesive tape of configuration B has an air-permeable base material between the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2), the plasticizer transferred from the adherend (H1) is an air-permeable group. It allows the material to pass through and is diffused throughout the double-sided adhesive tape except the release liner. According to the double-sided adhesive tape of configuration B, when the total thickness is within a predetermined range, the amount of the plasticizer transferred from the adherend (H1) to the double-sided adhesive tape of configuration B is suppressed from becoming excessive. This makes it possible to suppress a decrease in the texture of the adherend (H1) and the occurrence of curl due to a decrease in the amount of the plasticizer. Further, according to the double-sided adhesive tape of the configuration B, it is possible to suppress a decrease in the adhesive force of the double-sided adhesive tape due to the transfer of an excessive amount of the plasticizer from the adherend (H1). Since the plasticizer is less likely to be unevenly distributed at the interface between the adherend (H1) and the double-sided adhesive tape of the configuration B, it is possible to prevent a decrease in the adhesive strength. Further, when another adherend (H2) is attached to the adherend (H1) facing the adherend (H1) via the double-sided adhesive tape of the configuration B, the double-sided adhesive between the other adherend (H2) and the configuration B is adhered. Since the plasticizer is less likely to be unevenly distributed at the interface with the tape, it is possible to prevent a decrease in the adhesive force, and it is possible to firmly bond the adherend (H1) and the adherend (H2).

The double-sided adhesive tape of Configuration B may have a total thickness of 10 μm or more and 100 μm or less, preferably 15 μm or more and 63 μm or less, more preferably 20 μm or more and 40 μm or less, and even more preferably 20 μm or more and 30 μm or less. By setting the total thickness of the double-sided adhesive tape of the configuration B within the above range, it is possible to suppress an excessive transfer amount of the plasticizer from the adherend (H1) to the double-sided adhesive tape, and to suppress the transfer amount of the plasticizer to the adherend (H1). This is because it is possible to further enhance the effect of suppressing the decrease in the texture of the adherend (H1) due to the decrease in the amount of the plasticizer in), the generation of curl, and the decrease in the adhesive force of the double-sided adhesive tape over time.

The total thickness of the double-sided adhesive tape structure B, refers to the thickness from one of the outermost surface of the double-sided adhesive tape structure B to the other of the outermost surface, the length of the portion represented by reference numeral T ₂ of the in Figure 2 As expected. When the release liner is provided on both sides of the double-sided adhesive tape of the configuration B, the total thickness of the double-sided adhesive tape of the configuration B does not include the thickness of the release liner.

Further, when the thickness of the adherend (H1) having a thickness of 1 mm or more containing a plasticizer is set to 1, the total thickness of the double-sided adhesive tape of the configuration B is 1 mm or more. The thickness of the body (H1) is preferably 0.002 times or more and 0.08 times or less, more preferably 0.004 times or more and 0.08 times or less, and 0.01 times or more and 0.07 times or less. Is more preferable. By having the above relationship between the thickness of the adherend (H1) having a thickness of 1 mm or more containing the plasticizer and the total thickness of the double-sided adhesive tape of the configuration B, the plasticizer that can be impregnated in the double-sided adhesive tape of the configuration B can be impregnated. The amount of the agent can be reduced, sufficient adhesive force with the adherend (H1) can be provided, deterioration of the adhesive force with time can be suppressed, and the amount of the plasticizer in the adherend (H1) is reduced. This is because it is possible to effectively suppress the deterioration of the texture of the adherend (H1) and the occurrence of curl.

The total basis weight of the double-sided adhesive tape configuration B ^is preferably in the range of ^{10g / m 2 ~130g / m 2} , among them preferably in the range of ^{15g / m 2 ~93g / m 2} , more preferably is in the range of ^{20g / m 2 ~70g / m 2} , more preferably in the range of ^{20g / m 2 ~60g / m 2} . By setting the total basis weight of the double-sided adhesive tape of Configuration B within the above range, the amount of the plasticizer in the adherend (H1) can be increased while maintaining sufficient adhesive strength with the adherend (H1). It is possible to effectively suppress the deterioration of the texture of the adherend (H1) and the occurrence of curl due to the decrease, and further, it becomes easy to secure the long-term adhesiveness to the adherend (H2).

In the present specification, the total basis weight of the double-sided adhesive tape of ^{the configuration B represents the mass of the entire double-sided adhesive tape of the configuration B existing per unit area (1 m 2} ) of the double-sided adhesive tape of the configuration B, and is represented by the following formula. The value calculated based on is shown. However, the mass of the entire double-sided adhesive tape does not include the mass of the release liner.

Total basis weight of double-sided adhesive tape of configuration B (g / m ² ) = (mass of double-sided adhesive tape of configuration B) / (area on one side of double-sided adhesive tape)

<Adhesive layer (b1) and adhesive layer (b2)>
The pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) in the configuration B are partially or wholly impregnated with an air-permeable base material.

It is preferable that the total gel fraction of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is 1% by mass or more and 35% by mass. Thereby, even when the plasticizer is transferred to the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2), it is possible to effectively prevent the occurrence of peeling over time. Above all, the total gel content of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is preferably in the range of 1% by mass to 30% by mass, and is preferably in the range of 1% by mass to 25% by mass. It is more preferable that the plasticizer is in the range of 1% by mass to 15% by mass, even when the plasticizer is transferred to the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2). It is more preferable to effectively prevent the occurrence of.

In the present specification, the total gel fraction of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is previously adhered to a mixed solvent of 70 parts by mass of toluene and 30 parts by mass of methanol adjusted to 23 ° C. The double-sided adhesive tape of composition B whose total mass of the agent layer (b1) and the adhesive layer (b2) was measured was immersed for 72 hours, and then using an ultrasonic device, 15 at a frequency of 40 kHz in an atmosphere of 23 ° C. After vibrating for a minute, the total mass of the adhesive layer (b1) and the adhesive layer (b2) remaining in the mixed solvent after drying is measured, and the value calculated based on the following formula is used.

Gel fraction (% by mass) = {(total mass of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) remaining in the mixed solvent) / (the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b1) before immersion) b2) Total mass)} × 100

The mass of the pressure-sensitive adhesive layer constituting the double-sided adhesive tape before immersion is a value obtained by subtracting the mass of the air-permeable base material used for manufacturing the double-sided adhesive tape from the mass of the double-sided adhesive tape. Further, the mass of the remaining pressure-sensitive adhesive layer refers to a value obtained by subtracting the mass of the air-permeable base material from the mass of the residual material after drying.

The gel fraction calculated by using the mixed solvent and applying ultrasonic vibration does not correlate with the gel fraction with respect to the solvent of toluene alone, but the intermolecular and intramolecular hydrogen of the pressure-sensitive adhesive layer. It breaks the apparent bond due to binding, etc., and refers to the gel fraction caused by the cross-linking reaction of a cross-linking agent or the like.

The pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) have a storage elastic modulus in the range of 0.08 MPa to 0.12 MPa at 23 ° C. measured by a dynamic viscoelastic spectrum measured at a frequency of 1 Hz. It is preferable that the pressure is in the range of 0.08 MPa to 0.09 MPa, which can impart excellent adhesive strength at the initial stage of application to the adherend (H1), and also have adhesive strength due to the transfer of the plasticizer. It is more preferable because it can suppress the decrease with time.

Further, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) have a ratio (tan δ) of the loss elastic modulus to the storage elastic modulus at 60 ° C. measured by the dynamic viscoelastic spectrum measured at a frequency of 1 Hz, respectively. It is preferably in the range of 0.40 to 0.60, and it is preferably in the range of 0.45 to 0.50 that the double-sided adhesive tape adhered to the adherend (H1) is placed in an environment of 60 ° C. The plasticizer that can migrate from the adherend (H1) over time when left underneath is not unevenly distributed at the adhesive interface with the adherend (H1), and retains excellent adhesive strength and cohesive strength for a long period of time. It is more preferable to obtain a double-sided adhesive tape.

Further, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) have a ratio (tan δ) of the loss elastic modulus to the storage elastic modulus at 100 ° C. measured by a dynamic viscoelastic spectrum measured at a frequency of 1 Hz, respectively. It is preferably in the range of 0.55 to 0.80, and it is preferably in the range of 0.60 to 0.70 that the double-sided adhesive tape adhered to the adherend (H1) is placed in an environment of 100 ° C. The plasticizer that can migrate from the adherend (H1) over time when left underneath is not unevenly distributed at the adhesive interface with the adherend (H1), and retains excellent adhesive strength and cohesive strength for a long period of time. It is more preferable to obtain a double-sided adhesive tape.

The ratio (tan δ) refers to a value calculated based on the formula tan δ = loss elastic modulus (Pa) / storage elastic modulus (Pa).

The storage elastic modulus of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) at 23 ° C. and tan δ at 60 ° C. and 100 ° C. are described in the section of "1. Configuration A <Adhesive layer (a1)>". It can be measured by the method described.

Since the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) each have a storage elastic modulus at 23 ° C. within the above range and a tan δ at 60 ° C. and 100 ° C., the double-sided adhesive tape can be used as an adherend ( It is unlikely to cause peeling due to the repulsive force of H1), and even when left in an environment of 100 ° C or lower, interface peeling due to the transfer of the plasticizer from the adherend (H1) is effective. Can be suppressed.

The pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) are preferably formed of a pressure-sensitive adhesive having the same composition. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, synthetic rubber-based pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and the like. Among them, the versatility is high, the double-sided adhesive tape can be manufactured at a relatively low cost, and the effect of the present invention can be obtained by controlling the total thickness of the double-sided adhesive tape including the adhesive layer (b1) and the adhesive layer (b2). Since it is particularly easy to play, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) are preferably formed of an acrylic pressure-sensitive adhesive having the same composition.

As the acrylic pressure-sensitive adhesive, an acrylic polymer and, if necessary, a cross-linking agent, a tack-imparting resin and the like can be used, and the acrylic polymer, the cross-linking agent and the tack-imparting resin and the like are contained. It is preferable to use an acrylic pressure-sensitive adhesive because it is excellent in weather resistance and heat resistance. The details of the acrylic pressure-sensitive adhesive and the acrylic polymer, cross-linking agent, and tack-imparting resin contained in the acrylic pressure-sensitive adhesive are described in the above section "1. Configuration A <Adhesive layer (a1)>". Since the details are the same as those of the acrylic polymer, the cross-linking agent, and the tackifier resin contained in the pressure-sensitive adhesive and the acrylic pressure-sensitive adhesive, the description thereof is omitted here.

Above all, the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) preferably contains an acrylic copolymer having a structure derived from a carboxyl group-containing vinyl monomer. Further, the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) preferably contains an acrylic copolymer having a structure derived from a nitrogen-containing vinyl monomer.

That is, in the acrylic polymer in the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2), at least one of the carboxyl group-containing vinyl monomer and the nitrogen-containing vinyl monomer is a monomer constituting the acrylic copolymer. It is preferable to have it in the unit (monomer component), and it is possible to have both the carboxyl group-containing vinyl monomer and the nitrogen-containing vinyl monomer in the monomer unit (monomer component) constituting the acrylic copolymer. More preferred. The acrylic copolymer in the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) has at least one of a carboxyl group-containing vinyl monomer and a nitrogen-containing vinyl monomer as a monomer unit constituting the acrylic copolymer. The effect of being included in the (monomer component) is as described in the above section "1. Configuration A <Adhesive layer (a1)>".

The thicknesses of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) can be set individually, and even if the thickness of the pressure-sensitive adhesive layer (b1) and the thickness of the pressure-sensitive adhesive layer (b2) are the same. Well, it can be different. The thickness of each of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is not particularly limited as long as the total thickness of the double-sided adhesive tape of the constitution B can be within a predetermined range, and is, for example, 5 μm. It can be 95 μm or less, more preferably 5 μm or more and 85 μm or less, further preferably 15 μm or more and 53 μm or less, and even more preferably 20 μm or more and 40 μm or less. While maintaining sufficient adhesive strength with the adherend (H1), the texture of the adherend (H1) is effectively reduced and curls are generated by reducing the amount of the plasticizer in the adherend (H1). This is because it can be suppressed and it becomes easy to secure long-term adhesiveness to the adherend (H2).

<Air-permeable substrate>
The air-permeable base material in the configuration B is a layer interposed between the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2).

The air-permeable substrate preferably has air permeability that allows the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) to pass through or be impregnated. Specifically, the air-permeable base material is a test piece obtained by laminating 10 air-permeable base materials, and the smaller the Gale-type air permeability measured in accordance with JIS P8117 of the test piece, the more breathable. As the air-permeable substrate, it is preferable to use a Gale-type air permeability of 10 seconds / 100 ml or less, and more preferably 7 seconds / 100 ml or less. It is particularly preferable to use one having a second / 100 ml or less. When the air-permeable base material exhibits the above-mentioned air permeability, the plasticizer transferred from the adherend (H1) in contact with one of the pressure-sensitive adhesive layers passes through the air-permeable base material, and the above-mentioned air-permeable base material is used. The plasticizer can be relatively uniformly dispersed in the entire double-sided adhesive tape including the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) formed on both sides of the above. Thereby, the amount of the plasticizer transferred from the adherend (H1) to the double-sided adhesive tape of the constitution B can be adjusted, and the interfacial peeling due to the uneven distribution of the plasticizer can be effectively suppressed. .. The lower limit of the Gale-type air permeability of the air-permeable substrate can be 0 seconds / 100 ml.

The Gale-type air permeability of the air-permeable base material is the same as the method for measuring the Gale-type air permeability of the air-permeable base material described in the section "1. Configuration A <Non-air-permeable base material>". Can be measured with.

The air-permeable substrate preferably has a thickness in the range of 10 μm to 50 μm, and more preferably in the range of 20 μm to 45 μm. By using an air-permeable base material having a thickness in the above range, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the air-permeable base material, and the total thickness of the double-sided adhesive tape is increased. The size can be adjusted so that the amount of the plasticizer transferred from the adherend (H1) does not become excessive. Further, since the plasticizer transferred from the adherend (H1) permeates the air-permeable substrate and is diffused into the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2), the pressure-sensitive adhesive layer (b1) Further, it is possible to suppress uneven distribution of the plasticizer at the interface between the pressure-sensitive adhesive layer (b2) and the adherend, and to obtain a double-sided pressure-sensitive adhesive tape that retains excellent adhesive strength and cohesive strength for a long period of time. Further, by using the air-permeable base material having a thickness in the above range, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the air-permeable base material, and the tension of the air-permeable base material is increased. It is possible to obtain a double-sided adhesive tape having improved strength and excellent handling workability in a cutting process and a pasting process.

As the air-permeable base material, it is preferable to use a non-woven fabric base material or a porous film base material because it is thin and it is easy to secure the air permeability in the above range. Specific examples of the air-permeable base material include a non-woven fabric base material, a woven fabric base material, a fiber woven fabric (mesh base material) composed of monofilament yarn, and the like, and have a high tensile elasticity even if the thickness is thin. It is preferable to use a non-woven fabric base material that is easy to obtain or a mesh base material that is easy to obtain high Gale type air permeability.

The air-permeable substrate preferably does not contain a plasticizer. The reason and the like are the same as the reason and the like described in the above section "1. Configuration A <non-permeable base material>".

As the material of the non-woven fabric base material, a known and commonly used non-woven fabric used as a non-woven fabric of double-sided adhesive tape can be used. Typical examples include hemp such as Manila hemp, cellulosic fiber such as rayon, regenerated cellulose and wood pulp, chemical fiber such as acetate fiber, polyester fiber, polyvinyl alcohol fiber and polyamide fiber, and a mixture thereof. Further, if necessary, viscose impregnation or impregnation treatment using a thermoplastic resin as a binder may be performed.

Further, for the purpose of improving the strength of the nonwoven fabric, it is preferable to add a known and commonly used reinforcing agent in the nonwoven fabric manufacturing process. As the strengthening agent, the internal addition strengthening agent or the external addition strengthening agent may be used alone or in combination. As the internal addition strengthening agent, polyacrylamide-based resin, urea-formaldehyde-based resin, melamine-formaldehyde-based resin, epoxy-polyamide-based resin and the like can be used. In particular, a polyamide amine / epichlorohydrin resin, which is an epoxy-polyamide resin, is preferable because it significantly increases the interlayer strength of the nonwoven fabric. The amount of the internal addition strengthening agent added is preferably in the range of 0.2% by mass to 1% by mass, more preferably in the range of 0.3% by mass to 0.5% by mass with respect to the nonwoven fabric. On the other hand, as the external strengthening agent, a thermoplastic resin such as starch; viscose, carboxymethyl cellulose, polyvinyl alcohol, and polyacrylamide can be used. Above all, it is preferable to use the above-mentioned internal addition strengthening agent in order to increase the interlayer strength of the nonwoven fabric base material.

The basis weight of the nonwoven fabric base material ^is preferably in the range of ^{5g / m 2 ~20g / m 2} , preferably in the range of ^{5g / m 2 ~15g / m 2} , 7g / m 2 ~ It is more preferably in the range of 12 g / m ^2. The density of the nonwoven fabric base ^material, it is preferably in ^the range of 0.2g / ^{m 3} ~0.3g / m 3 is in the range of 0.15g / ^{m 3} ~0.35g / m 3 Is more preferable. Within the basis weight range of the nonwoven fabric base material, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the nonwoven fabric base material and migrate from the adherend (a1). Since the plasticizing agent is allowed to pass through, uneven distribution of the plasticizing agent in the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) can be suppressed, and a double-sided adhesive tape having excellent adhesive strength and cohesive power for a long period of time can be obtained. be able to. Further, by using the nonwoven fabric base material having a basis weight, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the base material, and the tensile strength of the nonwoven fabric base material is improved. , It is possible to improve the handling workability in the cutting process and the pasting process. The basis weight of the air-permeable substrate other than the nonwoven fabric substrate can be the same as that within the range of the basis weight of the nonwoven fabric substrate described above.

The method for making a non-woven fabric base material is not particularly limited, but is obtained by a known wet method, and a circular net paper machine, a short net paper machine, a long net paper machine, an inclined short net paper machine, or the like was used. Various papermaking methods are used.

As the porous film base material, a mesh base material obtained by weaving known monofilament fibers such as polyester resin, amide resin, and polyarylate resin in a screen shape can be used. Above all, it is preferable to use a polyester resin having a high tensile elastic modulus and tensile strength as the monofilament. As the form of the mesh base material, a mesh base material having a thickness of 10 to 50 μm in which 80 to 300 monofilament yarns having a fiber diameter of 5 to 25 μm are woven alternately in MD and TD per inch is used. Preferably, it is a mesh base material having a thickness of 10 to 50 μm in which 100 to 200 monofilament yarns having a fiber diameter of 5 to 25 μm are woven alternately in MD and TD per inch. Within the fiber diameter range of the mesh base material, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the base material and migrate from the adherend (a1) to the plasticizer. In order to allow the agent to pass through, it is possible to suppress uneven distribution of the plasticizer in the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2), and obtain a double-sided pressure-sensitive adhesive tape that retains excellent adhesive strength and cohesive strength for a long period of time. Can be done. Further, by using the mesh base material having the above thickness, the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) impregnate the pores of the mesh base material, and the tensile strength of the mesh base material is improved. , It is possible to improve the handling workability in the cutting process and the pasting process.

The preferred range of the basis weight and density of the porous film substrate can be the same as the basis weight and density of the above-mentioned nonwoven fabric substrate.

<Release liner>
In the double-sided adhesive tape of the configuration B, a release liner may be laminated on the adhesive layer (b1) and the adhesive layer (b2), respectively. As the release liner, the material described in the section "1. Configuration A <release liner>" can be used.

<Manufacturing method of double-sided adhesive tape of configuration B>
The double-sided adhesive tape of configuration B is a step of forming the adhesive layer (b1) and the adhesive layer (b2), respectively, by applying the adhesive to the surface of the release liner and drying the tape, respectively. The pressure-sensitive adhesive layer formed above can be produced by transferring it to both sides of the air-permeable substrate.

3. 3. Applications The double-sided adhesive tape of the present invention is used for attaching an adherend (H1) containing a plasticizer and having a thickness of 1 mm or more. Specifically, the double-sided adhesive tape of the present invention is used for fixing a plasticizer-containing soft sheet having a thickness of 1 mm or more. Above all, the double-sided adhesive tape of the present invention is suitably used for joining applications of building materials. This is because a plasticizer-containing soft sheet having a thickness of 1 mm or more is often used as a building material, and a simple fixing method, maintenance of the appearance of the building material, and strong fixing are required.

An adherend (H1) having a thickness of 1 mm or more containing a plasticizer is given flexibility by adding a plasticizer to such an extent that it can be wound into a roll shape when the adherend is manufactured. , An adherend (plasticizer-containing soft sheet) having a thickness of 1 mm or more.

The adherend (H1) is formed of a composition containing a plasticizer and a resin component, specifically, a composition containing a plasticizer and polyvinyl chloride, and a composition containing a plasticizer and rubber. Can be mentioned. Above all, since the migration of the plasticizer is relatively easy to occur, the adherend (H1) is a member formed of a composition containing a plasticizer and a polyvinyl chloride resin, or a composite material containing the member. In particular, the double-sided adhesive tape of the present invention can be suitably used for a soft polyvinyl chloride sheet in which migration of a plasticizer is relatively easy to occur.

Examples of the plasticizer contained in the adherend (H1) include phthalates such as di2-ethylhexyl phthalate, diisononyl phthalate and diisodecyl phthalate, phosphate esters such as trioctyl phosphate, dioctyl adipate and adipine. Examples thereof include aliphatic nibasic acid esters such as diisononyl acid and diisodecyl adipate, trimellitic acid esters such as tri2ethylhexyl trimellitic acid, and epoxy plasticizers such as butyl epoxy stearate. The plasticizer may be used alone or in combination of two or more.

Above all, the adherend (H1) preferably contains a phthalate ester as the plasticizer, and among the phthalates, it preferably contains diisononyl phthalate. This is because, in particular, when the adherend (H1) is a polyvinyl chloride sheet containing polyvinyl chloride, the polyvinyl chloride sheet can be efficiently plasticized.

The content of the plasticizer is preferably in the range of 10% by mass to 50% by mass, and preferably in the range of 15% by mass to 30% by mass with respect to the mass of the adherend (H1). Is more preferable, and more preferably in the range of 20% by mass to 26% by mass. The adherend (H1) having a plasticizer content in the above range has sufficient flexibility even in a low temperature environment of about 5 ° C. or lower, and can exhibit flexibility in a wide temperature range. This is because the desired texture can be expressed.

The adherend (H1) may contain an inorganic filler such as calcium carbonate, talc, calcined clay, kaolin, aluminum hydroxide, and titanium oxide in order to impart appropriate impact resistance according to the intended use. The amount of the inorganic additive used is preferably in the range of 10% by mass to 60% by mass, preferably in the range of 20% by mass to 40% by mass, based on the amount of the resin component such as polyvinyl chloride and rubber. This makes it possible to achieve both excellent impact resistance and a sufficient level of flexibility.

Further, the adherend (H1) may contain an organic pigment for coloring. As the organic pigment, carbon black or the like can be used. The amount of the organic pigment used is in the range of 2% by mass to 10% by mass with respect to the mass of polyvinyl chloride or rubber, so that good impact resistance and flexibility can be maintained.

The adherend (H1) may be a member composed of one layer or a composite material composed of two or more layers. In the case of a composite material composed of two or more layers, the composite material may contain a member containing a plasticizer, and all the layers may contain the plasticizer, and the layer containing the plasticizer and the composite material. It may be combined with a layer containing no plasticizer. When a composite material composed of two or more layers is used as an adherend, when the plasticizer is transferred from the composite material to the pressure-sensitive adhesive layer, different shrinkages occur between the two layers constituting the composite material. The curl of the material is more likely to occur. In particular, the double-sided adhesive tape of the present invention can be suitably used for suppressing the generation of curl of a composite material composed of two or more layers. The composite material composed of two or more layers includes, for example, a mode in which two or more layers are laminated, and a mode in which one layer is included in another layer.

Examples of the layer containing no plasticizer include sheets, films, papers, woven fabrics and the like made of a resin containing no plasticizer such as an acrylic resin and an ethylene-vinyl acetate copolymer (EVA).

Further, the layer containing no plasticizer may have air permeability or may be non-permeable. When the layer containing no plasticizer has air permeability, the layer containing the plasticizer is the pressure-sensitive adhesive layer (a1) in the double-sided adhesive tape of the structure A or both sides of the structure B via the layer containing no plasticizer. By coming into contact with the pressure-sensitive adhesive layer (b1) or (b2) in the pressure-sensitive adhesive tape, the effect of controlling the amount of plasticizer transferred by using the double-sided pressure-sensitive adhesive tape of the present invention can be easily exerted. The air permeability when the layer containing no plasticizer has air permeability and the air permeability when it is non-breathable are the same as the air permeability of the above-mentioned air-permeable base material and non-breathable base material. can do.

The thickness of the adherend (H1) may be 1 mm or more, preferably in the range of 1 mm to 5 mm, more preferably in the range of 1.2 mm to 3 mm, and even more preferably in the range of 1.5 mm to 2 mm. .. This is because when the thickness of the adherend (H1) is within the above range, a large amount of the plasticizer can be contained, and the texture and flexibility can be exhibited. When the adherend (H1) is a composite material composed of two or more layers, the thickness of the adherend (H1) means the total thickness of the layers containing the plasticizer.

The hardness of the adherend (H1) is preferably 100 or less, preferably 30 or more and 100 or less, and more preferably 50 or more and 100 or less. Generally, the higher the content of the plasticizer, the lower the hardness of the adherend (H1) and the more flexible it becomes. Therefore, since the adherend (H1) has the above-mentioned hardness, a large amount of the plasticizer is contained, and the plasticizer is easily transferred by the double-sided adhesive tape. Therefore, plasticization by using the double-sided adhesive tape of the present invention. The effect of controlling the transfer amount of the agent becomes easier to be exerted. When the adherend (H1) is a composite material composed of two or more layers, the hardness of the adherend (H1) means the hardness of the layer containing the plasticizer.

The hardness of the adherend shall be a value measured by an ASTM D2240 compliant Type A durometer.

The adherend (H1) is formed into a sheet by, for example, a composition containing a plasticizer and a resin component melted at a high temperature and subjected to any film forming method such as T-die extrusion molding, calender molding, and inflation molding. can do.

The adherend (H1) may be an article containing a plasticizer and having a thickness of 1 mm or more. Among them, the article is preferably a building material, specifically, a floor material, a wallpaper, a bathroom tile material. , Rooftop waterproofing material, cushioning material, sound insulating material, packing member of window frame, water insulating material of garden and waterway, etc.

Further, the double-sided adhesive tape of the present invention is provided through the double-sided adhesive tape by attaching another adherend (H2) to the surface opposite to the surface to which the adherend (H1) is attached. The adherend (H1) and another adherend (H2) can be bonded. For example, by attaching a wallpaper having a vinyl chloride soft sheet having a thickness of 1 mm or more to a wall via the double-sided adhesive tape of the present invention, it is possible to suppress deterioration of the texture of the wallpaper and generation of curl over time. In addition, it is possible to suppress the decrease in adhesive strength over time and prevent the wallpaper from peeling off from the wall.

The other adherend (H2) may be a resin material having a thickness of 1 mm or more containing a plasticizer, a resin material containing no plasticizer, or a resin material containing a plasticizer but having a thickness of less than 1 mm. There may be. Further, the other adherend (H2) may be an inorganic substance such as a metal plate, concrete, or glass. The other adherends (H2) will be described later in the section “II. Building materials with tape”, and thus the description thereof will be omitted here.

When the other adherend (H2) is a resin material having a lower content of the plasticizer than the adherend (H1) or substantially no plasticizer, the adherend (H1) and the subject. It is preferable to use the double-sided adhesive tape of Configuration A for bonding with the body (H2). In the double-sided adhesive tape of configuration B, the plasticizer contained in the adherend (H1) permeates the air-permeable base material and migrates into the double-sided adhesive tape, and further penetrates into the adherend (H2). In some cases. In this case, the transfer of the plasticizer from the adherend (H1) is promoted, and there is a possibility that the texture of the adherend (H1) is lowered and curl is more likely to occur. On the other hand, in the case of the double-sided adhesive tape having the configuration A, the transfer of the plasticizer is hindered by the non-permeable substrate, so that the plasticizer from the adherend (H1) by another adherend (H2). It is possible to prevent the promotion of migration.

II. Building Material with Tape The building material of the present invention is a building material containing a plasticizer and having a thickness of 1 mm or more, to which the double-sided adhesive tape described in the above section "I. Double-sided adhesive tape" is attached.

According to the building material with tape of the present invention, a double-sided adhesive tape having either structure A or structure B described in the above section "I. Double-sided adhesive tape" is applied to a building material containing a plasticizer and having a thickness of 1 mm or more. When the building material is attached to a desired place via the above-mentioned double-sided adhesive tape, the amount of the plasticizer contained in the building material transferred to the double-sided adhesive tape is suppressed from becoming excessive. can do. As a result, it is possible to prevent the texture of the building material from being impaired over time and curl of the building material, and further to suppress the decrease in the adhesive strength of the double-sided adhesive tape over time, so that the building material can be attached from the bonding surface. It becomes possible to make it difficult to peel off over time.

The double-sided adhesive tape in the present invention has an adhesive layer (a1) on one surface of the non-permeable substrate, and has an adhesive layer (a2) on the other surface of the non-permeable substrate. The structure A in which the thickness of the pressure-sensitive adhesive layer (a1) is 10 μm or more and 100 μm or less, or the pressure-sensitive adhesive layer (b1) on one surface side of the air-permeable base material is provided on the other surface of the air-permeable base material. It has one of the configurations B, which has a pressure-sensitive adhesive layer (b2) and has a total thickness of 10 μm or more and 100 μm or less. When the double-sided adhesive tape in the present invention has the structure A, the building material containing the plasticizer and having a thickness of 1 mm or more is attached to the pressure-sensitive adhesive layer (a1) of the double-sided adhesive tape of the structure A. On the other hand, when the double-sided adhesive tape in the present invention has the structure B, the building material containing the plasticizer and having a thickness of 1 mm or more may be attached to the pressure-sensitive adhesive layer (b1) of the double-sided adhesive tape of the structure B. It may be attached to the pressure-sensitive adhesive layer (b2).

Since the double-sided adhesive tape in the present invention is the same as that described in the above section "I. Double-sided adhesive tape", the description thereof is omitted here.

The building material in the present invention may be any building material containing a plasticizer and having a thickness of 1 mm or more, and the article exemplified as a specific example of the adherend (H1) in the above section "I. Double-sided adhesive tape" is used. Can be mentioned. Specific examples thereof include flooring materials, wallpaper, bathroom tile materials, rooftop waterproofing materials, cushioning materials, sound insulating materials, window frame packing materials, and building materials such as water insulating materials for gardens and waterways.

The building material with tape of the present invention may have a building material containing a plasticizer having a thickness of 1 mm or more attached to at least one surface of the double-sided adhesive tape, and the other surface of the double-sided adhesive tape (the above-mentioned building material). On the surface opposite to the surface to which the is attached), another adherend may be attached, or the other adherend may not be attached and may have a release liner. Since the release liner has been described in the above section "I. Double-sided adhesive tape", the description thereof is omitted here.

The other adherend attached to the other surface of the double-sided adhesive tape may or may not contain a plasticizer. Examples of other adherends include a resin sheet containing a plasticizer, a resin sheet not containing a plasticizer, an adherend made of an inorganic substance such as a metal plate, concrete, and glass, and a fabric made of fibers and the like. ..

III. Adhesive Strength Measuring Method In the adhesive strength measuring method of the present invention, a double-sided adhesive tape is attached to an adherend surface of an adherend containing a plasticizer and having a thickness of 1 mm or more, and one of the adherend and the double-sided adhesive tape is attached. Is a method of measuring the adhesive strength of the double-sided adhesive tape to the adherend by tensile-peeling at a pulling speed of 10 mm / min or less at a peeling angle of 90 ° to 180 °.

Generally, as a method for measuring the adhesive strength of a double-sided adhesive tape, a method for measuring the adhesive strength by, for example, 90-degree peeling or 180-degree peeling is widely used. In these methods, the double-sided adhesive tape is usually pulled from the adherend by pulling the double-sided adhesive tape at a relatively high tensile speed of 300 mm / min at a peeling angle of 90 ° or 180 °, and the strength measured at that time is measured. It is defined as the adhesive strength of double-sided adhesive tape to the body.

However, when the present inventors try to measure the adhesive strength of the double-sided adhesive tape to an adherend (H1) containing a plasticizer and having a thickness of 1 mm or more, the adhesive strength of the double-sided adhesive tape is the same as that of the adherend (H1) at the above-mentioned tensile speed. It has been found that when the double-sided adhesive tape is peeled off, it is difficult to accurately measure the true adhesive strength of the double-sided adhesive tape due to the transfer of the plasticizer from the adherend (H1). The adherend (H1) has a large thickness and contains a large amount of plasticizer, and the plasticizer contained in the adherend (H1) changes over time depending on the thickness of the adhesive layer of the double-sided adhesive tape. If a large amount of the adhesive is transferred to the side, the adhesive strength of the double-sided adhesive tape tends to decrease in addition to the deterioration of the adherend (H1). The present inventors measured the adhesive strength of a bonded product having a double-sided adhesive tape attached to the adherend (H1) at a general tensile speed, and detected a decrease in the adhesive strength due to the transfer of the plasticizer. It was found that the adhesive strength of the double-sided adhesive tape may be measured at a larger value than it actually is, even though it is difficult to do so and the adherend (H1) is deteriorated due to a decrease in the amount of the plasticizer. .. That is, the degree of deterioration of the adherend (H1) due to the decrease in the amount of the plasticizer does not correlate with the adhesive strength of the double-sided adhesive tape plasticized due to the migration of the plasticizer, and the adherend (H1) does not correlate. It is difficult to accurately measure the true adhesive strength of the double-sided adhesive tape by bonding over time.

Therefore, as a result of studies by the present inventors, the plasticizer is formed by peeling the tape and the adherend at a tensile speed (peeling speed) of 90 ° to 180 ° when the tape is pulled at a peeling angle of 90 ° to 180 ° or less. It has been found that the true adhesive strength of the double-sided adhesive tape to an adherend having a thickness of 1 mm or more can be measured. That is, according to the measuring method of the present invention, it is possible to accurately detect the adhesive force of the double-sided adhesive tape over time, which correlates with the deterioration of the adherend (H1) due to the migration of the plasticizer. Further, even when it is difficult to confirm the deterioration of the adherend (H1) from the appearance, the degree of deterioration of the adherend (H1) can be predicted from the change with time of the adhesive force measured by the measuring method of the present invention. can do.

The adherend used in the adhesive strength measuring method of the present invention may be any adherend containing a plasticizer and having a thickness of 1 mm or more, as described above in "I. Double-sided adhesive tape" and "II. Building materials with tape". Since the same can be applied to the adherend (H1) described in the above section, the description thereof is omitted here.

The adherend (H1) used in the adhesive strength measuring method of the present invention preferably has a rectangular shape, and the size thereof is in the range of 20 mm ± 10 mm in width and 100 mm ± 50 mm in effective length. It is preferably inside. The effective length is the length excluding the fixed portion (grasping margin) when set in the testing machine.

The double-sided adhesive tape used in the adhesive strength measuring method of the present invention preferably has a rectangular shape, and its size is usually the same length and width as the adherend (H1) to be attached.

In the adhesive strength measuring method of the present invention, it is preferable that the adherend (H1) and the double-sided adhesive tape are each allowed to stand in a standard environment before being attached. In the present invention, the standard environment means an atmosphere having a temperature of 23 ° C. ± 1 ° C. and a relative humidity of 50% RH ± 10% RH. In addition, it is preferable that the time for standing in the standard environment is about one day.

When affixed to the adherend surface of the adherend (H1), a release liner is usually provided on the surface of the double-sided adhesive tape opposite to the surface in contact with the adherend (H1).

After attaching the double-sided adhesive tape to the adherend (H1), it is preferable to apply a load from the double-sided adhesive tape side. This is because the adhesive strength can be measured more accurately by sufficiently adhering the adherend surface of the adherend (H1) and the double-sided adhesive tape to secure the adhesive area. When pressurizing on a surface, the load is ^{preferably in the range of 3N / cm 2 to} 50N / cm ² , and when pressurizing with a roller, for example, a method of reciprocating a 2kg roller once may be mentioned.

When measuring the adhesive strength (initial adhesive strength) immediately after sticking, the time from sticking the double-sided adhesive tape to the adherend (H1) to the measurement is not particularly limited, but generally, the adherend (H1). It can be one minute after the double-sided adhesive tape is attached to. In addition, for the purpose of stabilizing the adhesion of the double-sided adhesive tape to the adherend (H1), after attaching the double-sided adhesive tape to the adherend (H1), leave it to stand for about 20 to 60 minutes in a standard environment. Can be measured from.

Further, the bonded body to which the double-sided adhesive tape is attached to the adherend (H1) is allowed to stand under the conditions specified for the temperature, humidity, and time, and then measured by the method described later under predetermined conditions. Adhesive strength can be measured at. It is preferable that the bonded body that has been allowed to stand in a predetermined environment is allowed to stand in a standard environment for a certain period of time in the same manner as in the measurement of the initial adhesive strength before the measurement.

For example, using the above-mentioned bonded body that has undergone an accelerated test in which it is allowed to stand for 7 days under a heating condition of 80 ° C., the adhesive strength over time after long-term storage of the double-sided adhesive tape to the adherend (H1) is measured by the measurement method described later. can do.

In the adhesive strength measuring method of the present invention, a bonded body in which a double-sided adhesive tape is attached to an adherend (H1) is used, and one of the adherend and the double-sided adhesive tape in the bonded body is 90 ° to 180 °. Peel off by pulling at a pulling speed of 10 mm / min or less at a peeling angle of °. At this time, the adherend (H1) may be fixed and the double-sided adhesive tape may be pulled and peeled off (peeled off), or the double-sided adhesive tape may be fixed and the adherend (H1) may be pulled and peeled off (pulled). (Peel off) is also good. Above all, it is preferable to fix the adherend (H1) and pull off the double-sided adhesive tape. When the adherend (H1) is pulled and peeled off, the bending stress of the adherend (H1) is applied, and the measured adhesive force may include the above bending stress, but the double-sided adhesive tape side is pulled and peeled off. By doing so, it is possible to eliminate the bending stress of the adherend (H1) in the adhesive force, and more accurate measurement becomes possible.

The tensile speed (peeling speed) at the time of peeling the adherend and the double-sided adhesive tape may be 10 mm / min or less, preferably 5 mm / min or less, and more preferably 3 mm / min or less. .. Further, the lower limit of the tensile speed may be 0.001 mm / min or more as long as the adhesive force can be measured. By setting the tensile speed to the above-mentioned predetermined value or less, it is possible to more accurately detect the adhesive force of the double-sided adhesive tape to the adherend (H1), particularly the adhesive force of the double-sided adhesive tape over time due to the transfer of the plasticizer. can.

The adhesive strength can be measured using a testing machine used for measuring general-purpose adhesive strength, and can be measured using, for example, a Tencilon tensile tester. The measurement can be performed by setting a sample in a testing machine according to a general-purpose adhesive force measuring method (JIS Z0237) and setting the tensile speed within a predetermined range specified in the present invention. For example, in the case where the adherend in the bonded body is fixed and the double-sided adhesive tape is tensile-peeled at a predetermined tensile speed at a peeling angle of 180 °, the measurement can be carried out by the following method. First, the double-sided adhesive tape is slightly peeled off from the adherend (H1) of the bonded body, and one end of the adherend (H1) is fixed to the lower chuck of the pulling device portion of the Tencilon tensile tester to adhere to both sides. The tape is fixed to the upper chuck of the pulling device section of the Tensyllon tensile tester for measurement. From this state, the upper chuck is pulled at a predetermined tensile speed. As a result, the double-sided adhesive tape fixed to the upper chuck at a peeling angle of 180 ° is pulled at a predetermined tensile speed and peeled from the adherend (H1). The value measured at this time can be the adhesive strength due to 180 ° peeling.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and any one having substantially the same structure as the technical idea described in the claims of the present disclosure and having the same effect and effect is the present invention. Included in the technical scope of the disclosure.

This will be specifically described below with reference to examples.

The base materials used as the core in the double-sided adhesive tapes of Examples and Comparative Examples are as follows. The air permeability of each base material is set by stacking 10 base materials in 50% RH at 23 ° C., and the time required for an inner cylinder having a diameter of 28.6 mm and a weight of 567 g to fall and 100 ml of air to pass through. It was measured. As a measuring device, a Gale type air permeability manufactured by Toyo Seiki Seisakusho, which complies with JIS P8117, was used. From the viewpoint of air permeability, the base material A was a non-permeable base material and the base material B was an air permeable base material.
-Base material A: Polyethylene terephthalate film with a thickness of 12 μm ("Emblet PET-12", double-sided corona-treated product, manufactured by Unitika Ltd.), Gale type air permeability 3600 seconds / 100 ml or more-Base material B: Non-woven fabric with a thickness of 45 μm (Nippon Paper Papylia "No. 1215", basis weight 17 g / m ² ), Gale type air permeability 0.2 seconds / 100 ml

The gel fraction of the pressure-sensitive adhesive layer in the double-sided adhesive tapes obtained in Examples and Comparative Examples was measured by the following method. The double-sided adhesive tapes obtained in the above Examples and Comparative Examples were cut into a size of 40 mm × 50 mm, the release liners on both sides were peeled off, the mass was measured, and then the mass of toluene was adjusted to 23 ° C. The test piece was immersed in a mixed solvent of 30 parts by mass and 30 parts by mass of methanol for 72 hours, and then using an ultrasonic device (manufactured by AS ONE Co., Ltd., trade name: US CLEANER US-5R) at a frequency of 40 kHz at 23 ° C. It was vibrated for 15 minutes. After the vibration, the residue remaining in the mixed solvent was dried for 1 hour using a dryer (105 ° C.), and the mass was measured, and the gel fraction was calculated based on the following formula.

Gel fraction (% by mass) = {(mass of the pressure-sensitive adhesive layer remaining in the mixed solvent) / (mass of the pressure-sensitive adhesive layer before immersion)} × 100

The mass of the pressure-sensitive adhesive layer before immersion refers to the value obtained by subtracting the mass of the base material used for its production from the mass of the double-sided pressure-sensitive adhesive tape. Further, the mass of the residual pressure-sensitive adhesive layer refers to a value obtained by subtracting the mass of the base material from the mass of the residual material after drying. In Examples 1 to 3 and Comparative Example 1, a test piece from which the adhesive layer on the opposite side to the adhesive layer to be measured was removed from the double-sided adhesive tape from which the release liners on both sides were peeled off was used. The gel fraction of each pressure-sensitive adhesive layer was measured, and the mass of the pressure-sensitive adhesive layer before immersion at this time was a value obtained by subtracting the mass of the base material from the mass of the test piece.

(Example 1)
(1-1) Preparation of acrylic pressure-sensitive adhesive In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and a thermometer, 93.4 parts by mass of butyl acrylate, 3 parts by mass of vinyl acetate, and acrylic acid 2. 5 parts by mass of N-vinyl-2-pyrrolidrin, 0.1 part by mass of 2-hydroxyethyl acrylate, and 0.2 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator. It was dissolved in 100 parts by mass of ethyl acetate and polymerized at 80 ° C. for 8 hours to obtain an acrylic copolymer solution having a weight average molecular weight of 700,000. In this solution, with respect to 100 parts by mass of the acrylic copolymer (solid content), 15 parts by mass of rosin ester resin A-100 (manufactured by Arakawa Chemical Industry Co., Ltd.) as a tackifier resin and polymerized rosin ester resin D -135 (manufactured by Arakawa Chemical Industry Co., Ltd.) was added in an amount of 15 parts by mass, diluted with toluene and mixed to obtain an acrylic pressure-sensitive adhesive composition (s) having a non-volatile content of 40% by mass.

0.52 parts by mass of an isocyanate-based cross-linking agent (Coronate L-45E, solid content 45% by mass) manufactured by Tosoh Corporation was added to 100 parts by mass of the acrylic pressure-sensitive adhesive composition (s) having a non-volatile content of 40% by mass. The acrylic pressure-sensitive adhesive (S) was prepared. The content of the cross-linking agent (solid content) with respect to 100 parts by mass of the acrylic polymer (solid content) was 0.76 parts by mass.

(1-2) Double-sided adhesive tape S-1
After stirring the acrylic adhesive (S) with a dissolver stirrer for 15 minutes, apply the acrylic adhesive (S') to ^{the release liner with a roll coater so that the basis weight after drying is 35 g / m 2.} Then, it was dried in a dryer at 85 ° C. for 3 minutes to obtain a pressure-sensitive adhesive layer having a thickness of 33 μm.

By the above method, two tapes A having the adhesive layer having a thickness of 33 μm formed on the release liner are prepared, and the adhesive layers of the tape A are laminated on both sides of the base material A and rolled. (SA-1010 manufactured by Tester Sangyo Co., Ltd., small tabletop test laminator) was passed at a speed of 1 m / min while applying a pressure of 0.4 MPa, and then cured in a dryer at 40 ° C. for 48 hours. A double-sided adhesive tape S-1 having a configuration A, in which the pressure-sensitive adhesive layer (a1) was provided on one surface of the material A and the pressure-sensitive adhesive layer (a2) was provided on the other surface, was obtained. The double-sided adhesive tape S-1 has a thickness of the pressure-sensitive adhesive layers (a1) and (a2) of 33 μm, respectively, and the gel content of the pressure-sensitive adhesive layers (a1) and (a2) is 10% by mass, respectively. The total thickness of the tape was 78 μm.

(Example 2)
An acrylic pressure-sensitive adhesive (S) was applied to the release liner with a roll coater so that the basis weight after drying was 71 g / m ² and the thickness after drying was 67 μm to form a pressure-sensitive adhesive layer, and tape B was obtained. ..

Using the tape B instead of the tape A, the pressure-sensitive adhesive layer of the tape B is laminated on both sides of the base material A, and one surface of the base material A is covered with the pressure-sensitive adhesive layer (a1) and the other. A double-sided adhesive tape S-2 having the configuration A was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive layer (a2) was provided on each surface. In the double-sided adhesive tape S-2, the thicknesses of the adhesive layers (a1) and (a2) are 67 μm, respectively, and the gel content of the adhesive layers (a1) and (a2) is 10% by mass, respectively. The total thickness of the tape was 146 μm.

(Example 3)
(3-1) Preparation of Acrylic Adhesive Agent (T) In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and a thermometer, 93.4 parts by mass of butyl acrylate, 3 parts by mass of methyl acrylate, and 2 acrylic acid. .3 parts by mass of N-isopropylacrylamide, 0.1 part by mass of 2-hydroxyethyl acrylate, 0.2 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator, and 100 parts by mass of ethyl acetate. It was dissolved in parts by mass and polymerized at 80 ° C. for 8 hours to obtain an acrylic copolymer solution having a weight average molecular weight of 800,000. In this solution, 15 parts by mass of rosin ester resin A-100 (manufactured by Arakawa Chemical Industry Co., Ltd.) and polymerized rosin ester resin D-135 (Arakawa Chemical Co., Ltd.) were added to 100 parts by mass of the acrylic copolymer solid content. (Manufactured by Kogyo Co., Ltd.) was added in an amount of 15 parts by mass, diluted and mixed with methyl ethyl ketone to obtain an acrylic pressure-sensitive adhesive composition (t) having a non-volatile content of 45% by mass.

1.24 parts by mass of an isocyanate-based cross-linking agent (Coronate L-45E, solid content 45% by mass) manufactured by Tosoh Corporation was added to 100 parts by mass of the acrylic pressure-sensitive adhesive composition (t) having a non-volatile content of 45% by mass. The acrylic pressure-sensitive adhesive (T) was prepared. The content of the cross-linking agent (solid content) with respect to 100 parts by mass of the acrylic polymer (solid content) was 1.61 parts by mass.

(3-2) Double-sided adhesive tape T-1
An acrylic pressure-sensitive adhesive (T) was applied to the release liner with a roll coater so that the basis weight after drying was 71 g / m ² and the thickness after drying was 67 μm to form a pressure-sensitive adhesive layer, and a tape C was obtained.

Using tape C instead of tape B, the adhesive layer of the tape C is laminated on both sides of the base material A, and one surface of the base material A is covered with the adhesive layer (a1) and the other surface. A double-sided adhesive tape T-1 having the configuration A was obtained in the same manner as in Example 2 except that the pressure-sensitive adhesive layer (a2) was provided on the surface. In the double-sided adhesive tape T-1, the thicknesses of the adhesive layers (a1) and (a2) are 67 μm, respectively, and the gel content of the adhesive layers (a1) and (a2) is 2% by mass, respectively, and the double-sided adhesive tape T-1 is double-sided adhesive. The total thickness of the tape was 146 μm.

(Example 4)
This was carried out except that the base material B was used instead of the base material A, and the adhesive layers of the tape A were laminated on both sides of the base material B and then passed through a roll heated to 100 ° C. A double-sided adhesive tape S-3 having a configuration B was obtained in the same manner as in Example 1. The double-sided adhesive tape S-3 has a total basis weight of the adhesive layers (b1) and (b2) of 70 g / m ² , and the double-sided adhesive tape S-3 has a total basis weight of 87 g / m ^2. The total gel content of the layers (b1) and (b2) was 10% by mass, and the total thickness of the double-sided adhesive tape was 76 μm.

(Comparative Example 1)
Acrylic adhesive (S) is applied to the release liner with a roll coater so that the basis weight after drying is 142 g / m ² and the thickness after drying is 134 μm to form an adhesive layer, and tape D is obtained. rice field.

Using the tape D instead of the tape A, two tapes D are laminated on both sides of the base material A, and one surface of the base material A is covered with an adhesive layer (a1) and the other. A double-sided adhesive tape S-4 having the configuration A was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive layer (a2) was provided on each surface. The double-sided adhesive tape S-4 has a thickness of the pressure-sensitive adhesive layers (a1) and (a2) of 134 μm, respectively, and the gel content of the pressure-sensitive adhesive layers (a1) and (a2) is 10% by mass, respectively. The total thickness of the tape was 280 μm.

(Comparative Example 2)
Instead of the base material A, the base material B was used as a base material for the core, and an operation was performed in which adhesive layers were laminated on both sides of the base material B and then passed through a roll heated to 100 ° C. A double-sided adhesive tape S-5 having a configuration B was obtained in the same manner as in Example 2 except for the above. The double-sided adhesive tape S-5 has a total basis weight of the adhesive layers (b1) and (b2) of 142 g / m ² , and the double-sided adhesive tape S-5 has a total basis weight of 159 g / m ^2. The total gel content of the layers (b1) and (b2) was 10% by mass, and the total thickness of the double-sided adhesive tape was 144 μm.

(Comparative Example 3)
Instead of the base material A, the base material B is used as the base material of the core, and the pressure-sensitive adhesive layer of the tape C obtained in Example 3 is laminated on both sides of the base material B, and then heated to 100 ° C. A double-sided adhesive tape T-2 having a structure of B was obtained in the same manner as in Example 3 except that the operation of passing the tape through the roll was performed. The double-sided adhesive tape T-2 has a total basis weight of the adhesive layers (b1) and (b2) of 142 g / m ² , and the double-sided adhesive tape T-2 has a total basis weight of 159 g / m ^2. The total gel content of the layers (b1) and (b2) was 2% by mass, and the total thickness of the double-sided adhesive tape was 144 μm.

[evaluation]
<Creation of adherend (H1)>
Polyvinyl chloride resin compound using 100 parts by mass of polyvinyl chloride (polymerization degree 1400), 34 parts by mass of diisononyl phthalate, 25 parts by mass of calcium carbonate, 3 parts by mass of carbon black, and 3 parts by mass of barium-zinc stabilizer. Was prepared. Using the obtained polyvinyl chloride resin compound, a polyvinyl chloride sheet having a thickness of 1.5 mm was obtained by calendar molding (processing temperature 170 ° C.). This polyvinyl chloride sheet was used as an adherend (H1-1).

<Evaluation 1. Initial adhesive force to an adherend (adhesive body (H)) containing a plasticizer and having a thickness of 1 mm or more>
A double-sided adhesive tape from which one of the release liners was removed was attached to a PET film having a thickness of 25 μm, and the test piece was cut so as to have a width of 20 mm and an effective length of 100 mm. The test piece was left in an atmosphere of 23 ° C. and 50% RH for 1 day. Further, the adherend (H1-1) to which the double-sided adhesive tape was not attached was cut into a width of 20 mm and a length of 100 mm, and left under the same conditions as the test piece.

After the test piece was left to stand, the test piece and the adherend (H1-1) were peeled off and removed from the other release liner of the test piece in an atmosphere of 23 ° C. and 50% RH. H1-1) was attached, the 2 kg roller was reciprocated once, and the mixture was allowed to stand in the same atmosphere for 60 minutes to adhere them to obtain a sample.

The test piece was slightly peeled off from the adherend (H1-1) of the sample, and one end of the adherend (H1-1) was fixed to the lower chuck of the pulling device portion of the Tencilon tensile tester. The test piece is fixed to the upper chuck of the pulling device of the Tensylon tensile tester, and the upper chuck is pulled at a speed of 3 mm / min and 300 mm / min to peel off the test piece at an angle of 180 ° and bond the test piece. The force (180 degree peel adhesive force) was measured.

Although not described in the table to be described later, the measurement of pulling at a speed of 3 mm / min is an example of the adhesive strength measuring method of the present invention, while the measurement of pulling at a speed of 300 mm / min is the present invention. This is a comparative example of the method for measuring the adhesive strength of. The same applies to evaluation 2.

<Evaluation 2. Adhesive strength to adherend (H1) after long-term storage (180 degree peel adhesive strength)>
In the same manner as the evaluation method of the initial adhesive strength of the evaluation 1, a double-sided adhesive tape from which one of the release liners was removed was attached to the PET film, and the test piece was cut so as to have a width of 20 mm and an effective length of 100 mm. did. The adherend (H1-1) cut to a width of 20 mm and a length of 100 mm is attached to the surface from which the release liner has been peeled off, and the 2 kg roller is reciprocated once and left in the same atmosphere for 60 minutes. They were glued together to give a sample. Then, the sample was left under the heating condition of 80 ° C. for 7 days, then taken out under the atmosphere of 23 ° C. and 50% RH, and left in the same atmosphere for 60 minutes.

The test piece is slightly peeled off from the adherend (H1-1) of the sample after being left in the above-mentioned environment, and one end of the adherend (H1-1) is attached to the pulling device portion of the Tencilon tensile tester. The test piece is fixed to the lower chuck, the test piece is fixed to the upper chuck of the pulling device portion of the Tensylon tensile tester, and the upper chuck is pulled at a speed of 3 mm / min and 300 mm / min to pull the test piece by 180 °. The adhesive force (180 degree peel adhesive force) was measured after peeling at the angle of.

<Evaluation 3. Adhesion with the adherend (H1) after the heating acceleration test>
The degree of adhesion when the test piece of the sample after being left in the heating environment of Evaluation 2 was peeled off from the adherend (H1-1) by hand was evaluated according to the following criteria.
[Evaluation criteria]
〇: No problem.
Δ: Poor adhesion is observed.
X: Adhesion is clearly insufficient. There is floating or peeling.

<Evaluation 4. Texture evaluation of the adherend (H1) after the heating acceleration test>
The texture of the adherend (H1-1) after the adhesive strength of Evaluation 2 was measured was evaluated according to the following criteria.
[Evaluation criteria]
⊚: The texture is almost the same as before being attached to the double-sided adhesive tape.
〇: The texture is slightly harder than before it is attached to the double-sided adhesive tape, but there is no problem in practical use.
X: It is clearly harder than before being attached to the double-sided adhesive tape, and there is a problem in practical use.

<Evaluation 5. Curl evaluation of adherend (H1) after heating acceleration test>
The curl of the adherend (H1-1) after the adhesive strength of Evaluation 2 was measured was evaluated according to the following criteria.
[Evaluation criteria]
⊚: Almost no curl is felt when standing on a flat surface.
〇: When left on a flat surface, curl is felt at the edges, but there is no problem in practical use.
X: When left on a flat surface, a curl that is noticeable and practically problematic is felt as a whole.

<Evaluation 6. Texture evaluation (SUS) of adherend (H1)>
A test piece was prepared in the same manner as in the method for evaluating the initial adhesive strength in Evaluation 1 above, except that a stainless steel (SUS) plate was used instead of the PET film. The test piece was attached to the adherend (H1-1) at 23 ° C. and a 50% RH atmosphere, and the 2 kg roller was reciprocated once and left in the same atmosphere for 60 minutes to adhere them to the sample. Got Then, the sample was left under a heating condition of 80 ° C. for 7 days, then taken out under a 23 ° C. and 50% RH atmosphere, and the texture of the adherend (H1-1) was evaluated according to the same criteria as in Evaluation 4.

<Evaluation 7. Texture evaluation of adherend (H1) (EVA sheet)>
The adherend is the same as the evaluation method of the above evaluation 6 except that the SUS plate is changed to an ethylene-vinyl acetate copolymer (EVA) sheet (“Light EVA sheet ND-307”, Light Kasei Kogyo Co., Ltd.). The texture of (H1-1) was evaluated according to the same criteria as in Evaluation 4.

The results of each evaluation are shown in the table. For Examples 1 to 3 and Comparative Example 1, the thickness of the adhesive layer (a1) was calculated when the thickness of the adherend (H1-1) was 1. Further, for Example 4 and Comparative Examples 2 to 3, the total thickness of the double-sided adhesive sheet was calculated when the thickness of the adherend (H1-1) obtained in Evaluation 1 was 1.

When the double-sided adhesive tapes of Examples 1 to 4 were attached to a polyvinyl chloride sheet having a thickness of 1 mm or more and a heating acceleration test was carried out, deterioration of the texture of the polyvinyl chloride sheet and generation of curl were suppressed. It was suggested (evaluation 4, 5).

On the other hand, when the double-sided adhesive tapes of Comparative Examples 1 to 3 were attached to a polyvinyl chloride sheet having a thickness of 1 mm or more and a heating acceleration test was conducted, it was confirmed that the texture of the polyvinyl chloride sheet was deteriorated and curl was generated. Was done. In Comparative Example 2 and Comparative Example 3, the thickness of each pressure-sensitive adhesive layer provided via the base material was 100 μm or less, but since the air-permeable base material was used, the total thickness of the double-sided adhesive tape was 100 μm or less. It can be said that both sides of the adhesive layer accumulate the plasticizer, which causes the texture of the polyvinyl chloride sheet to deteriorate and curl to occur.

Further, from Evaluation 6 and Evaluation 7, among the double-sided adhesive tapes of Examples, the double-sided adhesive tapes of Examples 1 to 3 using the base material A which is a non-permeable base material are the base materials which are the air-permeable base material. Compared with the double-sided adhesive tape of Example 4 using A, the EVA sheet is made of a material in which other adherends bonded to the polyvinyl chloride sheet via the double-sided adhesive tape are more likely to accept the plasticizer. However, it was suggested that the deterioration of the texture of the polyvinyl chloride sheet was suppressed. It is presumed that this is because the non-permeable substrate prevents the transfer of the plasticizer from the polyvinyl chloride sheet, and the EVA sheet suppresses the promotion of the transfer of the plasticizer.

Further, in the measurement of the adhesive strength in Evaluation 1 and Evaluation 2, when the adhesive strength was measured at a tensile speed of 300 mm / min, the bonding of the double-sided adhesive tape of Comparative Examples 1 to 3 and the polyvinyl chloride sheet was evaluated. Although 4 and evaluation 5 were "x", no decrease in adhesive strength was confirmed in evaluation 2, and there was no correlation between the deterioration of the properties of the polyvinyl chloride sheet due to the transfer of the plasticizer and the decrease in the adhesive strength of the double-sided adhesive tape. rice field. On the other hand, when measured at a tensile speed of 3 mm / min, the adhesive strength of Evaluation 2 is larger than the adhesive strength of Evaluation 1 in the bonding of the double-sided adhesive tape of Comparative Examples 1 to 3 and the polyvinyl chloride sheet. It was confirmed that the adhesive strength was reduced due to the effect of excessive migration of the plasticizer. This suggests that in the double-sided adhesive tape of the comparative example, excessive migration of the plasticizer occurs, resulting in deterioration of the polyvinyl chloride sheet and deterioration of the adhesive strength. Further, by measuring the adhesive strength by low-speed peeling, it was confirmed that the deterioration of the polyvinyl chloride sheet shown in the evaluations 4 and 5 was correlated with the decrease in the adhesive strength.

Similarly, when the adhesive strength was measured at a tensile speed of 3 mm / min with respect to the bonded body of the double-sided adhesive tape of Examples 1 to 4 and the polyvinyl chloride sheet, the adhesive strength of evaluation 2 was evaluated as 1. The rate of decrease was smaller than that of the equivalent or comparative examples, and the evaluations 4 and 5 were "◯" or "◎". From this, it was suggested that the double-sided adhesive tape of the present invention suppressed the deterioration of the polyvinyl chloride sheet and the decrease in the adhesive strength due to the excessive transfer of the plasticizer. In addition, it is estimated that the actual value of the adhesive strength of the double-sided adhesive tape was measured by measuring the adhesive strength at low speed peeling, and the excessive transfer of the plasticizer was suppressed, so that the properties and both sides of the polyvinyl chloride sheet were suppressed. A correlation with the adhesive strength of the adhesive tape was confirmed.

10A ... Double-sided adhesive tape of configuration A ... Double-sided adhesive tape of configuration B k1 ... Non-permeable base material k2 ... Air-permeable base material a1, a2, b1, b2 ... Adhesive layer

Claims (10)

Used for attaching adherends containing a plasticizer and having a thickness of 1 mm or more.
The pressure-sensitive adhesive layer (a1) is provided on one surface of the non-permeable substrate, the pressure-sensitive adhesive layer (a2) is provided on the other surface of the non-permeable substrate, and the thickness of the pressure-sensitive adhesive layer (a1). Configuration A in which is 10 μm or more and 100 μm or less, or
It has a pressure-sensitive adhesive layer (b1) on one side of the air-permeable base material, has a pressure-sensitive adhesive layer (b2) on the other side of the air-permeable base material, and has a total thickness of 10 μm or more and 100 μm or less. B,
Double-sided adhesive tape having any of the above configurations. The pressure-sensitive adhesive layer (a1) is formed of an acrylic pressure-sensitive adhesive, and the acrylic pressure-sensitive adhesive contains an acrylic copolymer having a structure derived from a carboxyl group-containing vinyl monomer.
The double-sided adhesive tape according to claim 1, wherein the gel content of the pressure-sensitive adhesive layer (a1) is 1% by mass or more and 35% by mass or less. The pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) are formed of an acrylic pressure-sensitive adhesive, and the acrylic pressure-sensitive adhesive contains an acrylic copolymer having a structure derived from a carboxyl group-containing vinyl monomer. ,
The double-sided adhesive tape according to claim 1 or 2, wherein the total gel fraction of the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) is 1% by mass or more and 30% by mass or less. The double-sided pressure-sensitive adhesive tape according to claim 2 or 3, wherein the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (a1) contains an acrylic copolymer having a structure derived from a nitrogen-containing vinyl monomer. Any of claims 2 to 4, wherein the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (b1) and the pressure-sensitive adhesive layer (b2) contains an acrylic copolymer having a structure derived from a nitrogen-containing vinyl monomer. The double-sided adhesive tape described in item 1. The double-sided adhesive tape according to any one of claims 1 to 5, wherein the adherend is a member formed of a composition containing a plasticizer and a polyvinyl chloride resin, or a composite material containing the member. The double-sided adhesive tape according to any one of claims 1 to 6, which is used for joining applications of building materials. A building material with a tape, wherein the double-sided adhesive tape according to any one of claims 1 to 7 is attached to a building material containing a plasticizer and having a thickness of 1 mm or more. A double-sided adhesive tape is attached to the adherend surface of the adherend containing the plasticizer and having a thickness of 1 mm or more.
One of the adherend and the double-sided adhesive tape is tensile-peeled at a peeling angle of 90 ° to 180 ° at a tensile speed of 10 mm / min or less, and the adhesive strength of the double-sided adhesive tape to the adherend is measured. Adhesive strength measurement method. The method for measuring adhesive strength according to claim 9, wherein the double-sided adhesive tape is tensilely peeled off.

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