TW202223043A - Pressure-sensitive adhesive composition, pressure-sensitive adhesive layer, and pressure-sensitive adhesive sheet - Google Patents

Abstract

Provided are: a pressure-sensitive adhesive composition which can form pressure-sensitive adhesive layers low in permittivity and dielectric loss in a high-frequency band and suitable for bonding members for constituting millimeter-wave antennas; and a pressure-sensitive adhesive sheet. A pressure-sensitive adhesive composition according to a first aspect of the present invention has a permittivity at 28-GHz frequency of 2-5 and a dielectric loss at 28-GHz frequency of 0.0001-0.05. A pressure-sensitive adhesive composition according to a second aspect of the present invention has a permittivity at 60-GHz frequency of 2-5 and a dielectric loss at 60-GHz frequency of 0.0001-0.05.

Description

Adhesive composition, adhesive layer, and adhesive sheet

The present invention relates to an adhesive composition, an adhesive layer, and an adhesive sheet. More specifically, the present invention relates to an adhesive composition, an adhesive layer, and an adhesive sheet suitable for bonding a constituent member of a millimeter-wave antenna.

In recent years, the high-speed and large-capacity communication of portable communication devices such as smartphones has been developed year by year, and it is expected that the fifth generation (5G), which is the next-generation ultra-high-speed data communication standard, will be compared with the fourth generation (4G). It can achieve 100 times the ultra-high-speed/large-capacity communication, 1/10 the low latency, and more than 10 times the number of simultaneous connections.

In order to realize the above-mentioned ultra-high-speed/large-capacity communication, low latency, and multiple simultaneous connections under 5G, electromagnetic waves with a frequency exceeding 24 GHz called millimeter waves are used. Send a lot of information.

On the other hand, compared with the frequency band used by 4G, millimeter waves are easily attenuated due to resonant absorption with rain, oxygen in the air, water molecules, etc., have strong linearity, and are easy to reflect. The antenna used (hereinafter sometimes referred to as "millimeter-wave antenna") requires an antenna gain higher than that of the previous 4G communication.

Patent Document 1 discloses a configuration in which a cover member is laminated on a base material provided with an antenna element as a millimeter-wave antenna mounted on a portable communication device such as a smartphone, and the base material and the cover member are laminated. Use adhesive when attaching. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2019-186942

[Problems to be Solved by Invention]

For components constituting millimeter-wave antennas, it is known that the dielectric loss of the material will reduce the millimeter-wave. In order not to reduce the antenna gain, the millimeter-wave is also required to have a low dielectric constant in high frequency bands, especially low dielectric loss. characteristics. The adhesive used for lamination of the components constituting the millimeter-wave antenna also requires the characteristics of low dielectric constant and low dielectric loss in high frequency bands.

The present invention was conceived based on the above-mentioned circumstances, and an object of the present invention is to provide an adhesive layer that can be formed in a high frequency band with low dielectric constant and dielectric loss, and is suitable for bonding to a member constituting a millimeter-wave antenna The adhesive composition. In addition, another object of the present invention is to provide an adhesive layer with low dielectric constant and dielectric loss in a high frequency band, which is suitable for attaching to a member constituting a millimeter-wave antenna. In addition, another object of the present invention is to provide an adhesive sheet having a low dielectric constant and dielectric loss in a high frequency band and suitable for bonding an adhesive layer to a member constituting a millimeter-wave antenna. [Technical means to solve problems]

The first aspect of the present invention provides an adhesive composition having a dielectric constant of 2-5 at a frequency of 28 GHz and a dielectric loss of 0.0001-0.05 at a frequency of 28 GHz.

In the adhesive composition of the first aspect of the present invention, the dielectric constant at a frequency of 28 GHz is 2 to 5, so that the adhesive composition of the first aspect of the present invention can be used to improve the adhesion of the constituent members. The antenna gain of the millimeter-wave antenna is better.

In the adhesive composition of the first aspect of the present invention, the dielectric loss at a frequency of 28 GHz is 0.0001 to 0.05, which can improve the adhesion of the adhesive composition using the adhesive composition of the first aspect of the present invention. The antenna gain of the millimeter-wave antenna is better.

In the adhesive composition of the first aspect of the present invention, the dielectric constant at a frequency of 60 GHz is preferably 2-5. This configuration is preferable in that the antenna gain of the millimeter-wave antenna to which the constituent member is attached using the adhesive composition of the first aspect of the present invention can be improved.

In the adhesive composition of the first aspect of the present invention, the dielectric loss at a frequency of 60 GHz is preferably 0.0001-0.05. This configuration is preferable in that the antenna gain of the millimeter-wave antenna to which the constituent member is attached using the adhesive composition of the first aspect of the present invention can be improved.

The second aspect of the present invention provides an adhesive composition with a dielectric constant of 2-5 at a frequency of 60 GHz and a dielectric loss of 0.0001-0.05 at a frequency of 60 GHz.

In the adhesive composition of the second aspect of the present invention, the dielectric constant of 2 to 5 at a frequency of 60 GHz can improve the adhesion of the adhesive composition of the second aspect of the present invention to the structural member. The antenna gain of the millimeter-wave antenna is better.

In the adhesive composition of the second aspect of the present invention, the dielectric loss at a frequency of 60 GHz is 0.0001 to 0.05, which can improve the adhesion of the adhesive composition of the second aspect of the present invention to the structural member. The antenna gain of the millimeter-wave antenna is better.

Furthermore, a third aspect of the present invention provides an adhesive layer formed by the adhesive composition of the first aspect of the present invention or the adhesive composition of the second aspect of the present invention. Moreover, the 4th aspect of this invention provides the adhesive sheet which has the adhesive bond layer of the 3rd aspect of this invention. Since the adhesive layer of the third aspect of the present invention is formed from the adhesive composition of the first aspect of the present invention or the adhesive composition of the second aspect of the present invention, it can be used at high frequencies such as 28 GHz and 60 GHz. The dielectric constant and dielectric loss are reduced in the frequency band. Therefore, by using the adhesive sheet of the fourth aspect of the present invention having the adhesive layer of the third aspect of the present invention for lamination of members constituting the millimeter-wave antenna, the antenna gain of the millimeter-wave antenna can be improved and the better.

In addition, a fifth aspect of the present invention provides a millimeter-wave antenna comprising at least the adhesive sheet and substrate of the fourth aspect of the present invention, wherein the substrate has an antenna element on at least one side, and the substrate has the antenna. The above-mentioned adhesive sheet is attached to one side of the component. In the millimeter-wave antenna of the fifth aspect of the present invention, since the antenna element mounted on the substrate is attached by the adhesive sheet of the fourth aspect of the present invention, the radiation loss of the received millimeter-wave can be suppressed to a relatively low level. low, which can improve the antenna gain of the millimeter-wave antenna of the fifth aspect of the present invention. [Effect of invention]

The adhesive composition and the adhesive layer of the present invention exhibit lower dielectric constant and dielectric loss in the high frequency band of millimeter waves, and can suppress the radiation loss of millimeter waves to a lower level. Therefore, by bonding the constituent members of the millimeter-wave antenna using the adhesive sheet of the present invention, a millimeter-wave antenna exhibiting high antenna gain can be efficiently manufactured.

[1. Adhesive composition] The adhesive composition of the first aspect of the present invention only needs to have a dielectric constant of 2 to 5 at a frequency of 28 GHz, and a dielectric loss of 0.0001 to 0.05 at a frequency of 28 GHz, and is not particularly limited in other aspects. . The adhesive composition of the second aspect of the present invention only needs to have a dielectric constant of 2 to 5 at a frequency of 60 GHz and a dielectric loss of 0.0001 to 0.05 at a frequency of 60 GHz, and is not particularly limited in other aspects. . The adhesive layer of the third aspect of the present invention may be formed by the adhesive composition of the first aspect of the present invention or the adhesive composition of the second aspect of the present invention, and is not particularly limited in other respects. The pressure-sensitive adhesive sheet of the fourth aspect of the present invention is not particularly limited in other respects as long as it has the pressure-sensitive adhesive layer of the third aspect of the present invention. In this specification, the adhesive composition of the first aspect of the present invention and the adhesive composition of the second aspect of the present invention are collectively referred to as "the adhesive composition of the present invention" for short. In addition, there is a case where the adhesive layer of the third aspect of the present invention is simply referred to as "the adhesive layer of the present invention". In addition, there is a case where the adhesive sheet of the fourth aspect of the present invention is simply referred to as "the adhesive sheet of the present invention".

The adhesive composition of the present invention can have any form, for example, solvent type, emulsion type, hot melt type (hot melt type), solvent-free type (active energy ray hardening type, such as monomer mixture, or monomer type) mixture and some of its polymers, etc.), etc.

As mentioned above, the adhesive composition of the present invention may be in a solvent type, or may contain an organic solvent. The organic solvent is not particularly limited as long as it is an organic compound used as a solvent, and examples thereof include hydrocarbon-based solvents such as cyclohexane, hexane, heptane, and methylcyclohexane; aromatics such as toluene and xylene. family solvents; ester solvents such as butyl acetate, ethyl acetate, methyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone; methanol, ethanol, propanol, butanol, isobutyl ketone, etc. Alcohol-based solvents such as propanol, etc. In addition, the above-mentioned organic solvent may be a mixed solvent containing two or more kinds of organic solvents.

The dielectric constant of the adhesive composition of the first aspect of the present invention is controlled to be low at 28 GHz, which can suppress the radiation loss of millimeter waves. The frequency of the adhesive composition of the first aspect of the present invention is 5 or less, preferably 4.5 or less, more preferably 4 or less, still more preferably 3.5 or less, and may be 3.4 or less, 3.3 or less, 3.2 or less, or 3.1 below, below 3.0, or below 2.9. The lower limit value of the dielectric constant at a frequency of 28 GHz is not particularly limited, but is preferably 2 or more, and may be 2.1 or more, or 2.2 or more. Furthermore, the adhesive composition of the second aspect of the present invention preferably has a dielectric constant within the above-mentioned range at a frequency of 28 GHz.

The dielectric constant of the adhesive composition of the present invention at 28 GHz can be adjusted by adjusting the type of the base polymer, the monomer composition, the type or content of additives, etc. that constitute the adhesive composition. In this specification, the dielectric constant is measured by the method described in the examples disclosed below. Furthermore, the “relative permittivity” is the value obtained by dividing the “dielectric constant” by the “dielectric constant of a vacuum”, but since the “dielectric constant of a vacuum” is 1, in this specification, the “dielectric constant” is referred to as “dielectric constant”. "Constant" and "relative permittivity" are treated as having the same meaning.

The dielectric loss of the adhesive composition of the first aspect of the present invention is controlled to be low at 28 GHz, which can suppress the radiation loss of millimeter waves. The dielectric loss of the adhesive composition of the first aspect of the present invention at a frequency of 28 GHz is 0.05 or less, preferably 0.045 or less, more preferably 0.04 or less, more preferably 0.035 or less, and still more preferably 0.03 or less , more preferably 0.025 or less, and still more preferably 0.02 or less. The lower limit value of the dielectric loss at a frequency of 28 GHz is not particularly limited, but is preferably 0.0001 or more, and may be 0.0005 or more, or 0.001 or more. In addition, the adhesive composition of the second aspect of the present invention preferably has a dielectric loss in the above-mentioned range at a frequency of 28 GHz.

The dielectric loss of the adhesive composition of the present invention at 28 GHz can be adjusted by adjusting the type of the base polymer, the monomer composition, the type or content of additives, etc. that constitute the adhesive composition. In this specification, the dielectric loss is measured by the method described in the examples disclosed below.

The dielectric constant of the second adhesive composition of the present invention is controlled to be low at 60 GHz, which can suppress radiation loss of millimeter waves. The dielectric constant of the second adhesive composition of the present invention at a frequency of 60 GHz is 5 or less, preferably 4.5 or less, more preferably 4 or less, further preferably 3.5 or less, and may also be 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, or 2.9 or less. The lower limit value of the dielectric constant at a frequency of 60 GHz is not particularly limited, but is preferably 2 or more, and may be 2.1 or more, or 2.2 or more. Furthermore, the adhesive composition of the first aspect of the present invention preferably has a dielectric constant within the above-mentioned range at a frequency of 60 GHz.

The dielectric constant of the adhesive composition of the present invention at 60 GHz can be adjusted by adjusting the type of the base polymer, the composition of monomers, the type or content of additives, etc. that constitute the adhesive composition.

The dielectric loss of the second adhesive composition of the present invention at 60 GHz is controlled to be low, and the radiation loss of millimeter waves can be suppressed. The dielectric loss of the adhesive composition of the second aspect of the present invention at a frequency of 60 GHz is 0.05 or less, preferably 0.045 or less, more preferably 0.04 or less, more preferably 0.035 or less, and still more preferably 0.03 or less Furthermore, it is more preferably 0.025 or less, particularly preferably 0.02 or less, and may be 0.019 or less, 0.018 or less, 0.017 or less, 0.016 or less, 0.015 or less, 0.014 or less, 0.013 or less, or 0.012 or less. The lower limit value of the dielectric loss at a frequency of 60 GHz is not particularly limited, but is preferably 0.0001 or more, and may be 0.0005 or more, or 0.001 or more. Furthermore, the adhesive composition of the first aspect of the present invention preferably has a dielectric loss in the above-mentioned range at a frequency of 60 GHz.

The dielectric loss of the adhesive composition of the present invention at 60 GHz can be adjusted by adjusting the type of the base polymer, the monomer composition, the type or content of additives, etc. which constitute the adhesive composition.

The base polymer constituting the adhesive composition of the present invention is not particularly limited, and examples thereof include acrylic polymers, rubber-based adhesive compositions (natural rubber-based adhesive composition or synthetic rubber-based adhesive composition, etc.) as a base polymer containing a rubber-based polymer, a polysiloxane-based adhesive composition as a base polymer containing a polysiloxane-based polymer, Polyester-based polymer contained in polyester-based adhesive composition as base polymer, urethane-based polymer contained in urethane-based adhesive composition as base polymer, and polyamide-based polymer The polyamide-based polymer contained in the adhesive composition as the base polymer, and the epoxy-based adhesive composition contained as the base polymer The epoxy-based polymer and vinyl alkyl ether-based adhesive composition contained as the base The vinyl alkyl ether-based polymer contained in the polymer, the fluorine-based polymer contained in the fluorine-based adhesive composition as the base polymer, and the like. Among them, the above-mentioned base polymer is preferably an acrylic polymer or a rubber-based polymer in terms of controlling the dielectric constant and dielectric loss in a high frequency band to be low, transparency, weather resistance, adhesion reliability, etc. thing. That is, the adhesive composition of the present invention is preferably an acrylic adhesive composition containing the below-described acrylic polymer as a base polymer, and a rubber-based adhesive composition containing the below-described rubber-based polymer as a base polymer agent composition. In addition, a base polymer can be used individually or in combination of 2 or more types.

In this specification, "base polymer" refers to the main component of the polymer components contained in the adhesive composition (the component with the largest compounding ratio. The same below), typically refers to more than 50 weight of the above polymer components % ratio of ingredients. In addition, in this specification, when referring to a "base polymer", "a mixture of monomer components constituting a base polymer or a partial polymer of a mixture of monomer components constituting a base polymer" is included. In this specification, the above-mentioned "mixture of monomer components" includes the case of including a single monomer component and the case of including two or more monomer components. In addition, the above-mentioned "partial polymer of a mixture of monomer components" means a composition in which one or two or more of the monomer components constituting the above-mentioned "mixture of monomer components" are partially polymerized.

The content of the above-mentioned base polymer in the adhesive composition of the present invention is not particularly limited, but is preferably 75% by weight or more (eg, 75-99.9% by weight), more preferably 85% by weight or more (eg, 85-99.9% by weight) ).

The adhesive composition of the present invention preferably does not contain or substantially does not contain acidic group-containing monomers (eg, carboxyl group-containing monomers, sulfo group-containing monomers, phosphoric acid group-containing monomers, etc.). This configuration is preferable in that an excellent anticorrosion effect for antenna elements or wirings can be obtained. Furthermore, the content of the acid group-containing monomer is preferably 0.05 wt % or less (eg, 0 to 0.05 wt %), more preferably 0.01 wt % or less (eg, 0 to 0.01 wt %) with respect to the total amount of the adhesive composition. %), and more preferably 0.001% by weight or less (for example, 0 to 0.001% by weight) can be considered to be substantially not contained.

[1-1. Acrylic polymer (A)] The adhesive composition of the present invention is preferably an acrylic adhesive composition containing an acrylic polymer as a main component. In this specification, the acrylic polymer contained in the acrylic adhesive composition as a base polymer may be referred to as "acrylic polymer (A)". The specific content of the acrylic polymer (A) is not particularly limited, but is preferably 75% by weight or more (for example, 75 to 99.9% by weight relative to the total amount (total weight, 100% by weight) of the adhesive composition of the present invention. ), more preferably 85% by weight or more (eg, 85 to 99.9% by weight).

The adhesive composition containing the acrylic polymer (A) as a main component is not particularly limited, for example, a composition containing the acrylic polymer (A) as an essential component; A) a mixture of monomer components (sometimes referred to as "monomer mixture") or a partial polymer thereof as a composition of essential components, etc. Although not particularly limited, examples of the former include so-called solvent-type and water-dispersed compositions (emulsion-type compositions), and examples of the latter include so-called active energy ray-curable compositions. Furthermore, the above-mentioned adhesive composition may optionally contain other additives.

The above-mentioned "monomer mixture" includes the case of containing a single monomer component and the case of containing two or more types of monomer components. In addition, the above-mentioned "partial polymer" means a composition in which one or two or more of the constituent components of the above-mentioned monomer mixture are partially polymerized. Among them, the above-mentioned adhesive composition is preferably a composition containing a monomer mixture or a partial polymer thereof as an essential component.

The above-mentioned monomer components may be macromonomers. A macromonomer system is a high molecular weight monomer obtained by polymerizing a plurality of the above-mentioned monomer components. In the case of using a macromonomer, structural units derived from monomer components constituting the macromonomer exist continuously to some extent in the base polymer. Therefore, by using a macromonomer, the higher-order structure derived from the macromonomer can be introduced into the base polymer, and the properties required as an adhesive (adhesion force, cohesion force, step followability, etc.) can be easily adjusted. . The weight-average molecular weight of the aforementioned macromonomer is preferably 3,000-35,000, more preferably 4,000-30,000, further preferably 5,000-25,000, particularly preferably 6,000-20,000.

The acrylic polymer (A) is a polymer (polymer) containing an acrylic monomer as a necessary monomer unit (monomer unit). In other words, the acrylic polymer (A) is a polymer containing a structural unit derived from an acrylic monomer as a structural unit. That is, the acrylic polymer (A) is a polymer composed (formed) with an acrylic monomer as an essential monomer component.

The acrylic polymer (A) preferably contains an alkyl (meth)acrylate having a linear or branched alkyl group (hereinafter sometimes abbreviated as "alkyl (meth)acrylate") as essential A polymer of monomeric units. In addition, in this specification, "(meth)acryl group" means either one or both of "acryl group" and "methacryl group", and the other is the same.

The acrylic polymer (A) is preferably an alkyl (meth)acrylate having a branched alkyl group having 10 to 24 carbon atoms as a monomer unit (hereinafter sometimes referred to as "(meth)acrylic acid) A polymer of alkyl ester (A1)") and/or methacrylate (hereinafter sometimes referred to as "methacrylate (A2)") having a hydrocarbon group having a carbon number of 6 or more. That is, the above-mentioned acrylic polymer (A) is preferably an alkyl (meth)acrylate containing a long-chain branched alkyl group such as an alkyl (meth)acrylate (A1), Or obtained by polymerizing the monomer component of methacrylate having a long-chain hydrocarbon group such as methacrylate (A2). Through the action of the above-mentioned long-chain branched alkyl group or the above-mentioned long-chain hydrocarbon group and methacrylic acid group, the adhesive composition with low dielectric constant and low dielectric loss can be realized in high frequency band. In the case of a substrate with a millimeter-wave antenna, since the adhesive layer formed by the adhesive composition also has a low dielectric constant and low dielectric loss in a high frequency band, the radiation loss of the millimeter-wave can be suppressed. In addition, (meth)acrylate (A1) and methacrylate (A2) may contain the compound corresponding to any of these, respectively.

In order to reduce the dielectric constant and dielectric loss in the high frequency band, according to the Clausius-Mossotti equation, it is considered that the dipole moment of the molecule can be reduced and the molar volume can be increased. In the case where the base polymer serving as the main component in the adhesive composition of the present invention is the acrylic polymer (A), if the alkyl (meth)acrylate (A1) is used as the main monomer unit, it is considered that Due to the long-chain branched alkyl group, in the adhesive layer obtained from the adhesive composition of the present invention, the molar volume is increased, and the alkyl group has a branched chain, whereby the dipole moment is reduced. As described above, it is considered that an adhesive composition having a balance of both, such as an increase in molar volume and a decrease in dipole moment, is suitable for (meth)acrylic acid using a branched alkyl group having a carbon number of 10 to 24 as the alkyl group. It works in the case of the alkyl ester (A1).

Moreover, when the base polymer as the main component in the adhesive composition of the present invention is the acrylic polymer (A), if methacrylate (A2) is used as the main monomer unit, it is considered that relative to The polarization of the alkyl acrylate tends to be the acrylic group of the side chain, and the methacrylic group in the methacrylate (A2) has an α-methyl group, the polarization near the main chain is reduced, and the result is a dielectric Losses are reduced. In addition, it is considered that the hydrophobicity of the methacrylic base is higher than that of the acrylic base, whereby deterioration of dielectric loss due to moisture absorption can be suppressed.

The Tg of the homopolymer of the alkyl (meth)acrylate (A1) (alkyl (meth)acrylate having a branched alkyl group having 10 to 24 carbon atoms) is preferably -80 to 0°C, More preferably, it is -70--10 degreeC. If the Tg of the homopolymer is -80°C or higher, the elastic modulus of the adhesive layer at room temperature can be suppressed from being excessively lowered. If the Tg of the homopolymer is 0° C. or lower, an appropriate adhesive force can be secured. The Tg of the homopolymer is the value measured by a differential scanning calorimeter (DSC). In addition, the branched alkyl group has a carbon number of 10 to 24 from the viewpoint of satisfying the dielectric constant, dielectric loss and moderate elastic modulus in high frequency bands, and can be prepared by the acrylic polymer (A) As the production method, the alkyl (meth)acrylate having an alkyl group is appropriately selected. For example, when the (meth)acrylic polymer (A) is produced by solution polymerization or the like, the alkyl group is more preferably carbon number 10 to 18, more preferably carbon number 10 to 16, more preferably It has 10 to 14 carbon atoms. When the acrylic polymer (A) is produced by radiation polymerization or the like, the alkyl group is more preferably carbon number 12-18, more preferably carbon number 14-18. Furthermore, even if the Tg of the homopolymer of alkyl (meth)acrylate is -80 to 0°C, if the alkyl group is straight chain or the number of carbon atoms is 9 or less, the adhesive composition will be reduced in high frequency band. The effect of increasing the dielectric constant and reducing the dielectric loss is also small.

Examples of the alkyl (meth)acrylate (A1) include isodecyl acrylate (10 carbon atoms, Tg of homopolymer = -60°C, hereinafter abbreviated as Tg), isodecyl methacrylate (carbon number 10, Tg=-41℃), isomyristyl acrylate (carbon number 14, Tg=-56℃), isostearyl acrylate (carbon number 18, Tg=-18℃), 2-propylheptyl acrylate esters, isoundecyl acrylate, isododecyl acrylate, isotridecyl acrylate, isopentadecyl acrylate, isohexadecyl acrylate, isoheptadecyl acrylate, and the methacrylate-based monomers exemplified above. Alkyl (meth)acrylate (A1) may be used alone or in combination of two or more.

In addition, among the above-mentioned branched alkyl groups having 10 to 24 carbon atoms, those having branched alkyl groups such as tertiary butyl groups at the end of the ester group are considered to be particularly capable of increasing the molar volume and decreasing the dipole moment. . Adhesive compositions with a balance of both are preferred in this respect. Moreover, it is also preferable at the point which is excellent in the compatibility of the said acrylic polymer (A) and the additive mentioned later. The branched alkyl group at the end of the ester group is preferably a branched alkyl group having 4 to 6 carbon atoms such as tert-butyl, neopentyl, and tert-butyl, and more preferably Tributyl. As a preferable example of the alkyl (meth)acrylate (A1) which has a tertiary butyl group at the terminal of an ester group, the isostearyl acrylate represented by the following formula is mentioned. [hua 1]

In addition, as the alkyl (meth)acrylate (A1), compared with the alkyl methacrylate, the molar volume is increased and the dipole moment is decreased by the increase in the molar volume and the decrease in the dipole moment. It is preferable in terms of the effect of lowering the dielectric constant and lowering the dielectric loss in the high frequency band. On the other hand, the acrylic acid alkyl ester is preferable in that the polymerization time of the acrylic polymer (A) can be shortened and the productivity can be improved compared with the methacrylic acid alkyl ester. In particular, when the above-mentioned acrylic polymer (A) is cured by radiation polymerization, alkyl acrylate is suitable.

The content (ratio) of the above-mentioned alkyl (meth)acrylate (A1) in all monomer units of the acrylic polymer (A) (the total amount of monomer components constituting the acrylic polymer (A)) is not particularly Limited to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A), preferably 3 to 60% by weight, more preferably 5 to 55% by weight, and still more preferably 10 to 50% by weight %. It is preferable to use 3 wt % or more for low dielectric constant and low dielectric loss in high frequency band, and it is preferable to use 60 wt % or less for the maintenance of adhesive force and step followability.

The methacrylate (A2) has a hydrocarbon group having 6 or more carbon atoms in the ester moiety. Examples of the hydrocarbon group having 6 or more carbon atoms in the methacrylate (A2) include an aliphatic group, an alicyclic group-containing group, and an aromatic ring-containing group. As said aliphatic group, a linear or branched aliphatic group is mentioned.

When the hydrocarbon group having 6 or more carbon atoms is an aliphatic group, the number of carbon atoms in the hydrocarbon group is preferably 8 or more, more preferably 9 or more, and still more preferably 10 or more. The number of carbon atoms in the hydrocarbon group is preferably 22 or less, more preferably 20 or less, and still more preferably 16 or less.

Examples of the methacrylate (A2) in which the hydrocarbon group having 6 or more carbon atoms in the methacrylate (A2) is an aliphatic group include, for example, hexyl methacrylate, heptyl methacrylate, and methacrylic acid. Octyl, 2-ethylhexyl methacrylate, isooctyl methacrylate, nonyl methacrylate, isononyl methacrylate, decyl methacrylate, isodecyl methacrylate, ten methacrylate Monoalkyl esters, lauryl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, cetyl methacrylate, methacrylic acid Heptadecyl ester, octadecyl methacrylate, isostearyl methacrylate, stearyl methacrylate, nonadecyl methacrylate, eicosyl methacrylate and other methyl esters Alkyl Acrylate. Among them, lauryl methacrylate, tridecyl methacrylate, and isodecyl methacrylate are preferred.

When the hydrocarbon group having 6 or more carbon atoms is a group containing an alicyclic ring, the number of carbon atoms in the hydrocarbon group is preferably 8 or more, more preferably 10 or more. The number of carbon atoms in the hydrocarbon group is preferably 22 or less, more preferably 16 or less.

The above-mentioned hydrocarbon group having 6 or more carbon atoms in the methacrylate (A2) is a methacrylate (A2) containing an alicyclic group, for example, those having a cycloalkane ring (cyclopentane ring, cyclohexane ring) Cycloalkyl methacrylate of ring, cycloheptane ring, cyclooctane ring, etc.), having a bicyclic hydrocarbon ring (pinane ring, pinene ring, alkane ring, noralkane ring, noralkene ring methacrylates, etc.), methyl groups having aliphatic hydrocarbon rings with three or more rings (dicyclopentane, dicyclopentene, adamantane, tricyclopentane, tricyclopentene, etc.) Acrylate etc.

As said cycloalkyl methacrylate, for example, cyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, cycloheptyl methacrylate, and cyclooctyl methacrylate may be mentioned. esters, etc. As a methacrylate which has the said bicyclic hydrocarbon ring, alkyl methacrylates, such as methacrylate, methacrylate, and iso-xyl methacrylate, are mentioned, for example. As the methacrylate having the above-mentioned hydrocarbon ring having three or more rings, for example, dicyclopentyl methacrylate, dicyclopentyloxyethyl methacrylate, tricyclopentyl methacrylate, methacrylic acid may be mentioned. Alkyl methacrylates such as 1-adamantyl ester, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, etc.

When the hydrocarbon group having 6 or more carbon atoms is a group containing an aromatic ring, the number of carbon atoms in the hydrocarbon group is preferably 6-14, more preferably 6-10.

As the methacrylate (A2) in which the hydrocarbon group having 6 or more carbon atoms in the methacrylate (A2) is a group containing an aromatic ring, for example, an aromatic carbocyclic ring (for example, a monocyclic carbon such as a benzene ring) may be mentioned. ring, or condensed carbocyclic ring such as naphthalene ring, etc.), specifically, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, 6-(1,1' methacrylate) - Methacrylates such as biphenyl-4-yloxy)hexyl ester.

The methacrylate (A2) may have a (poly)oxyalkylene chain. In the case of having a (poly)oxyalkylene chain, it is preferable that the above-mentioned hydrocarbon group having 6 or more carbon atoms is the terminal of the ester moiety present in the methacrylate (A2). The number of oxygen atoms in the (poly)oxyalkylene chain (that is, the number of repetitions of the oxyalkylene group) is preferably 1-10, more preferably 1-3. The hydrocarbon group having 6 or more carbon atoms at the terminal may be any of an aliphatic group, an alicyclic group, and an aromatic group, preferably an alicyclic group or an aromatic group.

As a methacrylate (A2) which has a (poly)oxyalkylene chain and the said C6 or more hydrocarbon group, 2-phenoxyethyl methacrylate etc. are mentioned, for example.

The content (ratio) of the above-mentioned methacrylate (A2) in all the monomer units of the acrylic polymer (A) (the total amount of the monomer components constituting the acrylic polymer (A)) is not particularly limited, and relative to the The total amount (100% by weight) of the monomer components constituting the acrylic polymer (A) is preferably 10% by weight or more (for example, 10 to 99.9% by weight), more preferably 15% by weight or more (for example, 15 to 99.7% by weight) ), and more preferably 20% by weight or more (for example, 20 to 99.5% by weight). It is preferable to use 15 wt % or more in terms of low dielectric constant and low dielectric loss in high frequency bands. It is preferable to use 99.9% by weight or less in order to maintain the adhesion and step followability.

The above-mentioned alkyl (meth)acrylate (A1) and the above-mentioned methacrylate (A2) in the total monomer units of the acrylic polymer (A) (the total amount of the monomer components constituting the acrylic polymer (A)) ) of the total content (ratio) is not particularly limited, but is preferably 3 to 99.9 wt %, more preferably 5 to 99.7 wt % with respect to the total amount (100 wt %) of the monomer components constituting the acrylic polymer (A). % by weight, more preferably 10 to 99.5% by weight. It is preferable to use 3 wt % or more in terms of low dielectric constant and dielectric loss in high frequency bands, and 99.9 wt % or less is preferable in terms of maintaining adhesion and step followability.

Acrylic polymer (A) may contain (meth)acrylic acid alkyl ester (A1) and/or methacrylic acid ester (A2) in addition to, or substituted (meth)acrylic acid alkyl ester (A1) and/or methyl acrylate acrylic acid ester (A2), and contains (meth)acrylic acid alkyl ester other than (meth)acrylic acid alkyl ester (A1) and methacrylic acid ester (A2) (hereinafter sometimes referred to as "(meth)acrylic acid) Alkyl ester (B)") as a monomer component. By containing the alkyl (meth)acrylate (B), the Tg of the acrylic polymer (A) itself can be adjusted, the cohesive force and the adhesive force of the adhesive layer formed by the adhesive composition of the present invention can be adjusted, and the , which can improve stress relaxation and step follow-up.

Examples of the above-mentioned alkyl (meth)acrylate (B) include alkyl acrylates having a linear alkyl group having 1 to 24 carbon atoms, and alkyl acrylates having a branched chain having 3 to 9 carbon atoms. Alkyl acrylate having an alkyl group, alkyl methacrylate having a straight-chain alkyl group having 1 to 5 carbon atoms, and alkyl methacrylate having a branched alkyl group having a carbon number of 3 to 5 Esters, from the viewpoint of realizing low dielectric constant and low dielectric loss in high frequency bands of the adhesive composition of the present invention, are preferably acrylic acid having a linear alkyl group having 10 to 24 carbon atoms Alkyl esters. Alkyl (meth)acrylate (B) may be used alone or in combination of two or more.

Examples of the above-mentioned alkyl acrylate having a linear alkyl group having 1 to 24 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate (n-butyl acrylate), and amyl acrylate. ester, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, Pentadecyl acrylate, hexadecyl acrylate, heptadecyl acrylate, octadecyl acrylate, nonadecyl acrylate, eicosyl acrylate, etc.

Examples of the alkyl acrylate having a branched alkyl group having 3 to 9 carbon atoms include isopropyl acrylate, isobutyl acrylate, 2-butyl acrylate, 3-butyl acrylate, and isoamyl acrylate. ester, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, etc.

Examples of the alkyl methacrylate having a linear alkyl group having 1 to 5 carbon atoms include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. ester (n-butyl methacrylate), amyl methacrylate, etc. Examples of the alkyl methacrylate having a branched alkyl group having 3 to 5 carbon atoms include isopropyl methacrylate, isobutyl methacrylate, second butyl methacrylate, Tertiary butyl methacrylate, isoamyl methacrylate, etc.

The Tg of the homopolymer of the alkyl (meth)acrylate (B) is not particularly limited, but is preferably -100°C or higher (for example, -100 to 150°C), more preferably -90 to 140°C, and still more preferably It is -90～120℃. Moreover, the Tg of the said homopolymer may be -30 degrees C or less, and may be -40 degrees C or less. If the Tg of the homopolymer is -100° C. or higher, the elastic modulus of the adhesive layer at room temperature can be suppressed from being excessively lowered. By mixing the alkyl (meth)acrylate (B) with a high homopolymer Tg with the acrylic polymer (A), the cohesive force and adhesive force of the adhesive layer can be adjusted, and stress can be appropriately imparted Ease or step following.

Among them, the alkyl (meth)acrylate (B) preferably has a branched chain having 6 to 9 carbon atoms in terms of improving the stress relaxation properties of the adhesive layer and adjusting the step followability. The alkyl acrylate of the alkyl group is more preferably an alkyl acrylate having a branched alkyl group with a carbon number of 7 to 9, especially 2-ethylhexyl acrylate (branched chain with a carbon number of 8). alkyl, Tg=-70°C). In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss in high frequency bands, alkyl acrylates having a linear alkyl group having 8 to 24 carbon atoms in the alkyl group are preferred, More preferably, it is an alkyl acrylate having a linear alkyl group having an alkyl group of 10 to 24 carbon atoms, and particularly preferably lauryl acrylate (a linear alkyl group having 12 carbon atoms, Tg=-50°C).

In addition, as the alkyl (meth)acrylate (B), compared with the alkyl acrylate, the molar volume is increased and the dipole moment is decreased by the increase in the molar volume and the decrease in the dipole moment. It is preferable in terms of the effect of lowering the dielectric constant and lowering the dielectric loss in the frequency band. On the other hand, the acrylic acid alkyl ester is preferable in that the polymerization time of the acrylic polymer (A) can be shortened and the productivity can be improved compared with the methacrylic acid alkyl ester. In particular, when the above-mentioned acrylic polymer (A) is cured by radiation polymerization, alkyl acrylate is suitable.

The content (ratio) of the above-mentioned alkyl (meth)acrylate (B) in all the monomer units of the acrylic polymer (A) (the total amount of monomer components constituting the acrylic polymer (A)) is not particularly It is limited to preferably 1% by weight or more (for example, 1 to 95% by weight), more preferably 3 to 93% by weight, relative to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A), and further It is preferably 10 to 90% by weight, particularly preferably 20 to 85% by weight. It is preferable to use 1 wt % or more in terms of adhesive force, step followability, low dielectric constant in high frequency band (28 to 60 GHz), and low dielectric loss.

Alkyl acrylate ( More preferably, it is the sum of alkyl acrylate having a straight-chain alkyl group having an alkyl group of 10 to 24 carbon atoms) and alkyl methacrylate having a straight-chain alkyl group having a carbon number of 1 to 5 The content (ratio) is not particularly limited, but is preferably 0.1% by weight or more (for example, 0.1 to 97% by weight) relative to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A), more preferably It is 1-95 weight%, More preferably, it is 3-90 weight%, More preferably, it is 10-80 weight%, More preferably, it is 15-75 weight%, Especially preferably, it is 20-70 weight%. It is preferable to use 0.1 wt% or more in terms of low dielectric constant and low dielectric loss in high frequency band (28 to 60 GHz).

The above-mentioned alkyl acrylate having a branched alkyl group having 3 to 9 carbon atoms in all monomer units of the acrylic polymer (A) (the total amount of monomer components constituting the acrylic polymer (A)) (Preferably, the alkyl acrylate having a branched alkyl group having a carbon number of 6 to 9) and the total content of the alkyl methacrylate having a branched alkyl group having a carbon number of 3 to 5 (Ratio) is not particularly limited, but is preferably 0.1% by weight or more (for example, 0.1 to 80% by weight), more preferably 1, with respect to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A). -70 wt%, more preferably 3 to 60 wt%, still more preferably 10 to 60 wt%, particularly preferably 20 to 50 wt%. It is preferable to use 0.1% by weight or more in terms of adhesive force and step followability.

In the acrylic polymer (A), as monomer units, other than the above-mentioned alkyl (meth)acrylate (A1), the above-mentioned methacrylate (A2), and the above-mentioned alkyl (meth)acrylate (B) , and may also contain copolymerizable monomers (comonomers). That is, the acrylic polymer (A) may contain a copolymerizable monomer as a constituent monomer component. In addition, a comonomer can be used individually or in combination of 2 or more types.

As said copolymerizable monomer, the monomer containing a hydroxyl group is mentioned. When the acrylic polymer (A) contains a hydroxyl group-containing monomer as a monomer unit, it is easy to polymerize the monomer components constituting the polymer, and it is easy to obtain a good cohesive force. Therefore, it is easy to obtain strong adhesiveness, and it is easy to increase the gel fraction to obtain excellent resistance to foaming and peeling. Furthermore, it is easy to suppress the whitening of the adhesive sheet that occurs in a high-humidity environment. On the other hand, when the acrylic polymer (A) contains a large amount of a hydroxyl group-containing monomer as a monomer unit, the dielectric constant and dielectric loss in a high frequency band tend to increase.

The content (ratio) of the above-mentioned hydroxyl group-containing monomer with respect to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A) is not particularly limited. When the amount of the hydroxyl group-containing monomer is a certain value or more, adhesion reliability such as adhesiveness and foaming peeling resistance can be easily obtained due to the cohesive force. The content of the hydroxyl group-containing monomer is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, still more preferably 0.1% by weight or more, still more preferably 0.5% by weight or more, and particularly preferably 1% by weight or more. In addition, the content of the above-mentioned hydroxyl group-containing monomer is preferably 30 wt % or less, more preferably 25 wt % or less, and still more preferably 30 wt % or less, in terms of realizing low dielectric constant and low dielectric loss in high frequency bands. 20% by weight or less, particularly preferably 15% by weight or less. Moreover, in some embodiment of this invention, the said acrylic polymer (A) may not contain the monomer containing a hydroxyl group.

Furthermore, as said copolymerizable monomer, the monomer containing a nitrogen atom is mentioned. When the acrylic polymer (A) contains a nitrogen atom-containing monomer as a monomer unit, an appropriate cohesive force is easily obtained. Therefore, it is easy to increase the 180° (degree) peel adhesion force to the glass plate and the 180° peel adhesion force to the acrylic resin plate to obtain strong adhesion, and it is easy to increase the gel fraction to obtain excellent hair resistance. Foam peelability. Furthermore, the adhesive layer is easy to obtain moderate flexibility, and it is easy to adjust the 300% tensile residual stress within a specific range, so that excellent stress relaxation and excellent step followability are obtained. Furthermore, the rust inhibitor disclosed below is selective with respect to the solubility of the monomer, for example, the benzotriazole-based compound, which is one of the rust inhibitors, has good solubility for the monomer containing nitrogen atom.

When the above-mentioned acrylic polymer (A) contains the above-mentioned nitrogen atom-containing monomer as a monomer component constituting the polymer, among the above-mentioned all monomer components (100% by weight) constituting the acrylic polymer (A) The ratio of the nitrogen atom-containing monomer is not particularly limited, but is preferably 1% by weight or more, more preferably 3% by weight or more, and still more preferably 5% by weight or more. If the said ratio is 1 weight% or more, it is preferable from a viewpoint that favorable cohesion force is easy to be obtained, and the adhesion reliability at high temperature is easy to be obtained. Furthermore, the suppression and durability of cloudiness in a high-humidity environment can be further improved, and higher bonding reliability with respect to the adherend can be obtained, which is preferable. In addition, the ratio of the above-mentioned nitrogen atom-containing monomer is preferably 30% by weight or less, more preferably 25% by weight, in terms of obtaining an adhesive layer having moderate flexibility and obtaining an adhesive layer having excellent transparency. % by weight or less, more preferably 20% by weight or less, still more preferably 15% by weight or less, particularly preferably 10% by weight or less.

Furthermore, as said copolymerizable monomer, the monomer containing an alicyclic structure can be mentioned. When the acrylic polymer (A) contains an alicyclic structure-containing monomer as a monomer unit, it is easy to obtain an appropriate cohesive force. Therefore, it is easy to increase the 180° (degree) peel adhesion force to the glass plate and the 180° peel adhesion force to the acrylic resin plate to obtain strong adhesion, and it is easy to increase the gel fraction to obtain excellent hair resistance. Foam peelability. Furthermore, the adhesive layer is easy to obtain moderate flexibility, and it is easy to adjust the 300% tensile residual stress within a specific range, so that excellent stress relaxation and excellent step followability are obtained.

When the above-mentioned acrylic polymer (A) contains the above-mentioned alicyclic structure-containing monomer as a monomer component constituting the polymer, in the total monomer components (100% by weight) constituting the above-mentioned acrylic polymer (A) The ratio of the above-mentioned alicyclic structure-containing monomer is not particularly limited, but from the viewpoint of improving durability and obtaining high bonding reliability, it is preferably 1% by weight or more, more preferably 5% by weight or more, and further Preferably it is 10 weight% or more. In addition, the ratio of the above-mentioned alicyclic structure-containing monomer is preferably 50 wt % or less, more preferably 45 wt % or less, and still more preferably 40 wt %, in terms of obtaining an adhesive layer having moderate flexibility. % or less, more preferably 30 wt % or less, still more preferably 25 wt % or less, particularly preferably 20 wt % or less. Moreover, in some embodiment of this invention, the said acrylic polymer (A) may not contain the monomer containing an alicyclic structure.

The said acrylic polymer (A) can be obtained by polymerizing the said monomer unit (monomer component) by a well-known or usual polymerization method. As a polymerization method of the said acrylic polymer (A), a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a polymerization method by active energy ray irradiation (active energy ray polymerization method) etc. are mentioned, for example. Among them, in terms of transparency, water resistance, cost, and the like of the adhesive layer, a solution polymerization method and an active energy ray polymerization method are preferred, and an active energy ray polymerization method is more preferred.

Examples of active energy rays to be irradiated during the above-mentioned active energy ray polymerization (photopolymerization) include ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, and ultraviolet rays, and ultraviolet rays are particularly preferred. . In addition, the irradiation energy, irradiation time, irradiation method, etc. of the active energy rays are not particularly limited, as long as the photopolymerization initiator can be activated to cause the reaction of the monomer components.

In the polymerization of the above-mentioned acrylic polymer (A), various common solvents can be used. Examples of such solvents include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as hexane; organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, a solvent can be used individually or in combination of 2 or more types.

Moreover, at the time of superposition|polymerization of the said acrylic polymer (A), a polymerization initiator, such as a thermal polymerization initiator and a photoinitiator (photoinitiator), can be used according to the kind of polymerization reaction. In addition, a polymerization initiator can be used individually or in combination of 2 or more types.

系光聚合起始劑等。再者，光聚合起始劑可單獨使用或組合使用2種以上。It does not specifically limit as said photoinitiator, For example, benzoin ether type photoinitiator, acetophenone type photoinitiator, α-ketol type photoinitiator, aromatic Sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzophenone-based photopolymerization initiator, condensate Ketone-based photopolymerization initiator, 9-oxysulfur 𠮿

It is a photopolymerization initiator, etc. In addition, a photopolymerization initiator can be used individually or in combination of 2 or more types.

系光聚合起始劑，例如可例舉：9-氧硫𠮿

、2-氯-9-氧硫𠮿

、2-甲基-9-氧硫𠮿

、2,4-二甲基-9-氧硫𠮿

、異丙基-9-氧硫𠮿

、2,4-二異丙基-9-氧硫𠮿

、十二烷基-9-氧硫𠮿

等。As said benzoin ether-based photopolymerization initiator, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2- Diphenylethane-1-one, anisole, etc. As the above-mentioned acetophenone-based photopolymerization initiator, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxy ring Hexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-(tert-butyl)dichloroacetophenone, etc. As the above-mentioned α-ketoalcohol-based photopolymerization initiator, for example, 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropane may be mentioned. -1-keto, etc. As said aromatic sulfonyl chloride-based photopolymerization initiator, 2-naphthalenesulfonyl chloride etc. are mentioned, for example. As said photoactive oxime type|system|group photoinitiator, 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime etc. are mentioned, for example. As said benzoin type photopolymerization initiator, benzoin etc. are mentioned, for example. As the above-mentioned benzil-based photopolymerization initiator, for example, benzil and the like may be mentioned. As the above-mentioned benzophenone-based photopolymerization initiator, for example, benzophenone, benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyethylene benzophenone, α-hydroxycyclohexyl phenyl ketone, etc. As said ketal type photopolymerization initiator, benzalkonium dimethyl ketal etc. are mentioned, for example. As the above-mentioned 9-oxosulfur 𠮿

It is a photopolymerization initiator, for example, 9-oxysulfur 𠮿

, 2-chloro-9-oxysulfur

, 2-methyl-9-oxothio

, 2,4-dimethyl-9-oxothio

, isopropyl-9-oxothioate

, 2,4-diisopropyl-9-oxothio

, dodecyl-9-oxysulfur

Wait.

The usage amount of the above-mentioned photopolymerization initiator is not particularly limited. It is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.5 part by weight.

Further, the thermal polymerization initiator is not particularly limited, and examples thereof include azo-based polymerization initiators, peroxide-based polymerization initiators (for example, dibenzyl peroxide, maleic peroxide, etc.) acid tert-butyl ester, etc.), redox-based polymerization initiators, and the like. Among them, the azo-based polymerization initiator disclosed in Japanese Patent Laid-Open No. 2002-69411 is preferable. As the above-mentioned azo-based polymerization initiator, 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as "AIBN"), 2,2'-azobis-2-methylbutyronitrile, Nitrile (hereinafter sometimes referred to as "AMBN"), 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, and the like.

The usage amount of the above-mentioned thermal polymerization initiator is not particularly limited. ) of the total amount of monomer components) 100 parts by weight, preferably 0.05 to 0.5 parts by weight, more preferably 0.1 to 0.3 parts by weight.

[1-2. Carboxyl group-containing monomer, etc.] When the adhesive composition of the present invention contains the acrylic polymer (A) as the base polymer, as the monomer component constituting the acrylic polymer (A), a carboxyl group-containing monomer may be contained, and a substantial amount is preferred. It does not contain carboxyl-containing monomers. In addition, "substantially not containing" means that it does not voluntarily mix unless it is unavoidably mixed. In addition, the carboxyl group-containing monomer means a monomer having at least one carboxyl group in the molecule. From the viewpoint of obtaining a more excellent anti-corrosion effect, specifically, the content of the carboxyl group-containing monomer is preferably 0.05 with respect to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A). % by weight or less (for example, 0 to 0.05 wt %), more preferably 0.01 wt % or less (for example, 0 to 0.01 wt %), and still more preferably 0.001 wt % or less (for example, 0 to 0.001 wt %) Essentially does not contain. In addition, as said carboxyl group-containing monomer, (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, etc. are mentioned, for example. Moreover, the monomer containing an acid anhydride group, such as maleic anhydride and itaconic anhydride, is also contained in the said carboxyl group-containing monomer, for example. Moreover, for example, the derivative|guide_body couple|bonded with esters, such as itonic acid, may be sufficient.

When the adhesive composition of the present invention contains the acrylic polymer (A) as a base polymer, it is preferable to use the acrylic polymer (A) as the constituent acrylic polymer from the viewpoint of obtaining a more excellent anticorrosion effect. The monomer component does not substantially contain a carboxyl group-containing monomer, but also does not substantially contain an acidic group other than a carboxyl group (sulfo group, phosphoric acid group, etc.) as a monomer component constituting the acrylic polymer (A). of the monomer. That is, it is preferable that the acrylic polymer (A) does not substantially contain any of a carboxyl group-containing monomer and a monomer having another acidic group as a constituent monomer component. Specifically, the total amount of the carboxyl group-containing monomers and monomers having other acidic groups as the monomer components constituting the acrylic polymer (A) is relative to the total amount of the monomer components constituting the acrylic polymer (A) (100% by weight), preferably 0.05% by weight or less (for example, 0 to 0.05% by weight), more preferably 0.01% by weight or less (for example, 0 to 0.01% by weight), and still more preferably 0.001% by weight or less (for example, , 0 to 0.001% by weight) can be considered to be substantially not contained.

Furthermore, from the same viewpoint, the adhesive composition of the present invention preferably contains no or substantially no acid group-containing monomer as a monomer component constituting a polymer other than the acrylic polymer (A). body. For example, it is preferable that the carboxyl group-containing monomer is not substantially contained. In addition, the meaning of "substantially not containing", the preferable degree, the monomer which has an acidic group other than a carboxyl group, etc. are the same as the case of the monomer component which comprises an acrylic polymer (A).

[1-3. Monomers containing basic groups] Furthermore, when the adhesive composition of the present invention contains the acrylic polymer (A) as a base polymer, it is preferable that the monomer component constituting the acrylic polymer (A) does not contain or substantially does not contain the acrylic polymer (A). Contains basic group-containing monomers. Moreover, it is also preferable that the monomer component constituting polymers other than the acrylic polymer (A) does not substantially contain a basic group-containing monomer, even if it is not a monomer component constituting various polymers When it is preferable that the said adhesive layer does not contain the monomer containing a basic group substantially, it is the same as the case of the monomer containing a carboxyl group. In addition, the meaning of "substantially does not contain", the preferable degree, etc. are also the same.

[1-4. Hydroxyl-containing monomer] The hydroxyl group-containing monomer means a monomer having at least one hydroxyl group in the molecule. Moreover, the monomer which has at least one hydroxyl group in a molecule|numerator and has at least one carboxyl group in a molecule|numerator is a monomer containing a carboxyl group, and is not a monomer containing a hydroxyl group. Although it does not specifically limit as said hydroxyl group-containing monomer, Specifically, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, -Hydroxybutyl, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, (meth)acrylate ) Hydroxydecyl acrylate, hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl) (meth)acrylate and other hydroxyl-containing (meth)acrylates; vinyl alcohol, allyl alcohol, etc. Among them, as the above-mentioned hydroxyl group-containing monomer, from the viewpoint of easily obtaining good cohesive force and easily obtaining adhesion reliability at high temperature, hydroxyl group-containing (meth)acrylates are preferred, and 2-acrylic acid is more preferred. Hydroxyethyl ester (HEA), 2-hydroxypropyl (meth)acrylate (HPA), 4-hydroxybutyl acrylate (4HBA). Furthermore, the hydroxyl group-containing monomer may be used alone or in combination of two or more.

[1-5. Monomers containing nitrogen atoms] The nitrogen atom-containing monomer means a monomer having at least one nitrogen atom in the molecule (in 1 molecule). However, the above-mentioned hydroxyl-containing monomer does not include the above-mentioned nitrogen atom-containing monomer. That is, in this specification, the monomer containing a nitrogen atom includes the monomer which has a hydroxyl group and a nitrogen atom in a molecule|numerator. Moreover, the monomer which has at least one nitrogen atom in a molecule|numerator and has at least one carboxyl group in a molecule|numerator is a monomer containing a carboxyl group, and is not a monomer containing a nitrogen atom.

As the above-mentioned nitrogen atom-containing monomer, N-vinyl cyclic amides, (meth)acrylamides and the like are preferred from the viewpoint of improving the foaming and peeling resistance. In addition, the monomer containing a nitrogen atom can be used individually or in combination of 2 or more types.

(式(1)中，R ¹表示二價之有機基) The N-vinyl cyclic amide is preferably an N-vinyl cyclic amide represented by the following formula (1) from the viewpoint of easily obtaining a good cohesive force and easily obtaining adhesion reliability at high temperature as the N-vinyl cyclic amide amide. [hua 2]

(In formula (1), R ¹ represents a divalent organic group)

R ¹ in the above formula (1) is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (for example, an alkylene group having 3 to 5 carbon atoms, etc. ).

The N-vinyl cyclic amide represented by the above formula (1) is preferably N-vinyl- 2-Pyrrolidone (NVP), N-vinyl-2-piperidinone, N-vinyl-2-caprolactamide, N,N-dimethyl(meth)acrylamide, N,N -Diethyl(meth)acrylamide, N-vinyl-3-morpholinone, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-morpholinone Diketones, etc., more preferably N-vinyl-2-pyrrolidone, N-vinyl-2-caprolactamide, N,N-dimethyl(meth)acrylamide, N,N-diketone Ethyl(meth)acrylamide, more preferably N-vinyl-2-pyrrolidone.

As said (meth)acrylamides, for example: (meth)acrylamides, N-alkyl (meth)acrylamides, N,N-dialkyl (meth)acrylamides Wait. As said N-alkyl (meth)acrylamide, for example, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-n-butyl ( Methyl) acrylamide, N-octyl acrylamide, etc. Furthermore, the above-mentioned N-alkyl(meth)acrylamide also includes, for example, dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, and dimethylaminopropyl (meth)acrylamide having an amine group based on (meth)acrylamide. As said N,N-dialkyl (meth)acrylamide, for example: N,N- dimethyl (meth)acrylamide, N,N- diethyl (meth)acrylamide Amine, N,N-Dipropyl(meth)acrylamide, N,N-Diisopropyl(meth)acrylamide, N,N-Di-n-butyl(meth)acrylamide, N , N-di-tert-butyl (meth) acrylamide and so on.

In addition, the above-mentioned (meth)acrylamides include, for example, various N-hydroxyalkyl(meth)acrylamides. As said N-hydroxyalkyl(meth)acrylamide, for example, N-methylol(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide , N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide amine, N-methyl-N-2-hydroxyethyl (meth)acrylamide, etc.

In addition, the above-mentioned (meth)acrylamides include, for example, various N-alkoxyalkyl(meth)acrylamides. As said N-alkoxyalkyl (meth)acrylamide, for example: N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide Amines etc.

Moreover, as a nitrogen atom-containing monomer other than the said N-vinyl cyclic amides and the said (meth)acrylamides, for example, aminoethyl (meth)acrylate, (methyl) Amine group-containing monomers such as dimethylaminoethyl acrylate, dimethylaminopropyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; acrylonitrile, methacrylonitrile, etc. Monomers of cyano groups; (meth)acryloylmorpholine, N-vinylpiperidine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyridine, N-vinylmorpholine, N-vinyl - vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyrrolidone, (meth)acryloylpyrrolidone, (Meth) acryl pyrrolidine, (meth) acryl piperidine, N-methyl vinyl pyrrolidone and other heterocyclic monomers; N-cyclohexyl maleimide, N-iso Maleimide monomers such as propylmaleimide, N-laurylmaleimide, N-phenylmaleimide, N-methyliconimide, N-ethyl Iconimide, N-butyl Iconimide, N-Octyl Iconimide, N-2-Ethylhexyl Iconimide, N-Lauryl Iconimide, Iconimide-based monomers such as N-cyclohexyliconimide, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6- Butadiimide-based monomers such as oxyhexamethylene butanediimide, N-(meth)acryloyl-8-oxyoctamethylene butanediimide, etc., containing imide groups monomers; 2-(meth)acryloyloxyethyl isocyanate and other monomers containing isocyanate groups, etc.

[1-6. Monomer containing alicyclic structure] The alicyclic structure-containing monomer refers to a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group, and having an alicyclic structure (but equivalent to methacrylate ( A2) is excluded). For example, an alkyl (meth)acrylate having a cycloalkyl group is included in the above-mentioned alicyclic structure-containing monomer. However, monomers having at least one alicyclic structure in the molecule and at least one carboxyl group in the molecule are carboxyl group-containing monomers, not alicyclic structure-containing monomers. In addition, the monomer containing an alicyclic structure can be used individually or in combination of 2 or more types.

The alicyclic structure in the above-mentioned alicyclic structure-containing monomer is a cyclic hydrocarbon structure, preferably carbon number 5 or more, more preferably carbon number 6-24, more preferably carbon number 6-15, particularly preferably The carbon number is 6-10.

[化4]

[化5]

As the monomer containing the alicyclic structure, for example, cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl acrylate, acrylic acid 3, 3,5-trimethylcyclohexyl acrylate, cycloheptyl acrylate, cyclooctyl acrylate, isocyanyl acrylate, dicyclopentyl acrylate, HPMPA represented by the following formula (2), and the following formula (3) (meth)acrylic monomers, such as TMA-2 represented, and HCPA represented by following formula (4). In addition, in the following formula (4), the bonding position of the cyclohexyl ring connected by a line and the structural formula in the parentheses is not particularly limited. Among these, isocyanic acid acrylate, cyclohexyl acrylate, and 3,3,5-trimethylcyclohexyl acrylate are preferred. [hua 3]

[hua 4]

[hua 5]

[1-7. Other comonomers] As the copolymerizable monomer in the acrylic polymer (A), in addition to the above-mentioned nitrogen atom-containing monomer, hydroxyl group-containing monomer, and alicyclic structure-containing monomer, for example, alkyl (meth)acrylates may be mentioned. Oxyalkyl esters [for example, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, (meth)acrylate base) 3-methoxypropyl acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 4-ethoxybutyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, etc.]; epoxy group-containing monomers [eg, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate esters, etc.]; sulfonic acid group-containing monomers [for example, sodium vinylsulfonate, etc.]; phosphoric acid group-containing monomers; (meth)acrylates with aromatic hydrocarbon groups (but equivalent to methacrylates (A2 )) [for example, phenyl acrylate, phenoxyethyl acrylate, benzyl acrylate, etc.]; vinyl esters [for example, vinyl acetate, vinyl propionate, etc.]; aromatic vinyl compounds [for example, benzene ethylene, vinyltoluene, etc.]; olefins or dienes [eg, ethylene, propylene, butadiene, isoprene, isobutylene, etc.]; vinyl ethers [eg, vinyl alkyl ether, etc.]; vinyl chloride ; All carbons of the repeating units of the main chain have side chain substituted methylene compounds, etc.

Furthermore, as a copolymerizable monomer in the said acrylic polymer (A), a polyfunctional monomer can also be mentioned. The multifunctional monomer functions as a crosslinking component. As said polyfunctional monomer, for example, hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, ( Poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate , trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, divinylbenzene, cyclic Oxyacrylates, polyester acrylates, urethane acrylates, etc. In addition, a polyfunctional monomer can be used individually or in combination of 2 or more types.

The content (ratio) of the above-mentioned polyfunctional monomer in all the monomer units of the acrylic polymer (A) is not particularly limited, and is based on the total amount (100% by weight) of the monomer components constituting the acrylic polymer (A). ), preferably 0.5% by weight or less (for example, 0 to 0.5% by weight), more preferably 0 to 0.35% by weight, still more preferably 0 to 0.2% by weight. If the content of the polyfunctional monomer is 0.5% by weight or less, the adhesive layer has a moderate cohesive force, and it is easy to improve the adhesive force or the level difference absorption, which is preferable. Furthermore, when a cross-linking agent is used, the polyfunctional monomer may not be used. When the cross-linking agent is not used, the content of the polyfunctional monomer is preferably 0.001-0.5 wt %, more preferably 0.001- 0.35% by weight, more preferably 0.002 to 0.2% by weight.

The weight average molecular weight (Mw) of the acrylic polymer (A) is preferably 100,000 to 5,000,000, more preferably 500,000 to 4,000,000, and still more preferably 750,000 to 3,000,000. The structure in which the weight average molecular weight of the acrylic polymer (A) is 100,000 or more is preferable in terms of improving the adhesive force or retention properties, and improving the resistance to foaming and peeling. On the other hand, the weight-average molecular weight of the acrylic polymer (A) is preferably 5,000,000 or less in that it is easy to improve the adhesive force and improve the foaming peeling resistance.

The weight average molecular weight (Mw) of the said acrylic polymer (A) can be calculated|required by polystyrene conversion by GPC (Gel Permeation Chromatography) method. For example, the measurement can be performed under the following conditions using a high-speed GPC apparatus "HPLC-8120GPC" manufactured by Tosoh Co., Ltd. Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000 Solvent: Tetrahydrofuran Flow rate: 0.6 ml/min

Although the glass transition temperature (Tg) of the said acrylic polymer (A) is not specifically limited, -70-100 degreeC is preferable, -65-50 degreeC is more preferable, -60-10 degreeC is still more preferable. When the glass transition temperature of the acrylic polymer (A) is -70°C or higher, it is easy to improve the cohesive force and improve the resistance to foaming and peeling, which is preferable. In addition, when the glass transition temperature of the acrylic polymer (A) is 100° C. or lower, the adhesive layer has moderate flexibility, and it is easy to obtain good adhesive force or good level difference absorption, and it is easy to obtain excellent adhesion reliability. , so it is better.

The glass transition temperature (Tg) of the said acrylic polymer (A) is the glass transition temperature (theoretical value) represented by the following formula of FOX. 1/Tg=W ₁ /Tg ₁ +W ₂ /Tg ₂ +・・・+W _n /Tg _n In the above formula, Tg represents the glass transition temperature (unit: K) of the acrylic polymer (A), and Tg _i represents the single The glass transition temperature (unit: K) when the monomer _i is formed into a homopolymer, and Wi represents the weight fraction in the total amount of the monomer components of the monomer i (i=1, 2, ... n). As Tg of the homopolymer of the monomer which comprises the said acrylic polymer (A), the following value can be employ|adopted. 2-ethylhexyl acrylate-70℃ n-hexyl acrylate-65℃ n-octyl acrylate-65℃ isononyl acrylate-60℃ n-nonyl acrylate-58℃ n-butyl acrylate-55℃ ethyl acrylate-20℃ Lauryl acrylate 0℃ 2-ethylhexyl methacrylate-10℃ Methyl acrylate 8℃ N-butyl methacrylate 20℃ Methyl methacrylate 105℃ Lauryl methacrylate-65℃ Isodecyl methacrylate Ester-41℃ Cyclohexyl methacrylate 66℃ Isoyl methacrylate 173℃ Dicyclopentyl methacrylate 175℃ 2-phenoxyethyl methacrylate 5℃ Benzyl methacrylate 54℃ Methyl 2-(2-methoxyethoxy)ethyl methacrylate-3℃ 2-hydroxyethyl methacrylate 55℃ Acrylic acid 106℃ Methacrylic acid 228℃ N-vinylpyrrolidone 86℃ Vinyl acetate 32 ℃ Styrene 100℃

In addition, the value described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be used as the Tg of the homopolymer of the monomer not described above. Furthermore, as the Tg of the homopolymer of the monomer not described in the above-mentioned document, the value obtained by the above-mentioned measurement method (the peak top temperature of tan δ obtained by the viscoelasticity test) can be used.

[1-8. Acrylic polymer (B)] When the adhesive composition of the present invention contains an acrylic polymer (A) as a base polymer, the adhesive composition preferably contains the acrylic polymer (A) and has a weight average molecular weight of 1,000 to 30,000. Acrylic polymer (B). When the acrylic polymer (B) is contained, the adhesiveness to the adherend at the interface in the adhesive sheet is improved, so that strong adhesiveness is easily obtained, and excellent foaming and peeling resistance is easily obtained. In addition, in this specification, "the acrylic polymer (B) whose weight average molecular weight is 1,000-30,000" may be abbreviated as "acrylic polymer (B)".

As the above-mentioned acrylic polymer (B), preferably, an acrylic polymer composed of a (meth)acrylate having a cyclic structure in the molecule as an essential monomer component, more preferably a molecular An acrylic polymer composed of a (meth)acrylate having a cyclic structure and an alkyl (meth)acrylate having a linear or branched alkyl group as essential monomer components. That is, as said acrylic polymer (B), the acrylic polymer containing the (meth)acrylate which has a cyclic structure in a molecule|numerator as a monomer unit is preferably mentioned, The (meth)acrylate of a cyclic structure and the acrylic polymer having a linear or branched alkyl (meth)acrylate as a monomer unit.

The cyclic structure (ring) of the (meth)acrylate having a cyclic structure in the molecule (in one molecule) (hereinafter sometimes referred to as "ring-containing (meth)acrylate") may be an aromatic ring , any of the non-aromatic rings is not particularly limited. As said aromatic ring, an aromatic carbocyclic ring [for example, a monocyclic carbocyclic ring, such as a benzene ring, or a condensed carbocyclic ring, such as a naphthalene ring, etc.], various aromatic heterocyclic rings, etc. are mentioned, for example. As said non-aromatic ring, for example, non-aromatic alicyclic ring (non-aromatic alicyclic ring) [for example, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, Cycloalkane rings such as alkane rings; cycloalkene rings such as cyclohexene rings, etc.], non-aromatic bridged rings [for example, pinane rings, pinene rings, alkane rings, noralkane rings, noralkene rings, etc. bicyclic hydrocarbon rings; aliphatic hydrocarbon rings with three or more rings (bridged hydrocarbon rings) among the adamantane rings, etc.], non-aromatic heterocycles [for example, epoxy rings, oxolane rings, oxetane ring, etc.] etc.

Examples of the aliphatic hydrocarbon rings having three or more rings (bridged hydrocarbon rings having three or more rings) include, for example, a dicyclopentyl group represented by the following formula (5a), and a dicyclopentyl group represented by the following formula (5b), for example. A cyclopentenyl group, an adamantyl group represented by the following formula (5c), a tricyclopentenyl group represented by the following formula (5d), a tricyclopentenyl group represented by the following formula (5e), and the like. [hua 6]

That is, as the above-mentioned ring-containing (meth)acrylate, for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and (meth)acrylate may, for example, be mentioned. Cycloalkyl (meth)acrylates such as cyclooctyl acrylate; (meth)acrylates having bicyclic aliphatic hydrocarbon rings such as iso(meth)acrylates; dicyclopentane (meth)acrylates ester, dicyclopentyloxyethyl (meth)acrylate, tricyclopentyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate (Meth)acrylates having aliphatic hydrocarbon rings of three or more rings, such as alkyl esters and 2-ethyl-2-adamantyl (meth)acrylates; (meth)acrylates such as phenyl (meth)acrylates Aryl acrylate, aryloxyalkyl (meth)acrylate such as phenoxyethyl (meth)acrylate, arylalkyl (meth)acrylate such as benzyl (meth)acrylate, etc. have aromatic (meth)acrylate of sexual ring, etc. Among them, as the above-mentioned ring-containing (meth)acrylate, a non-aromatic ring-containing (meth)acrylate is particularly preferred, and cyclohexyl acrylate (CHA), cyclohexyl methacrylate ( CHMA), dicyclopentyl acrylate (DCPA), dicyclopentyl methacrylate (DCPMA), and more preferably dicyclopentyl acrylate (DCPA) and dicyclopentyl methacrylate (DCPMA). In addition, a ring-containing (meth)acrylate can be used individually or in combination of 2 or more types.

Among the above-mentioned non-aromatic ring-containing (meth)acrylates, in the case of using (meth)acrylates having an aliphatic hydrocarbon ring having three or more rings (especially a bridged hydrocarbon ring having three or more rings), In particular, it is preferable that polymerization inhibition is not easily caused. In addition, when using a dicyclopentyl group represented by the above formula (5a) without an unsaturated bond, an adamantyl group represented by the above formula (5c), and a tricyclopentyl group represented by the above formula (5d) ( In the case of meth)acrylate, the resistance to foaming and peeling can be further improved, and further, the adhesiveness to a low-polarity adherend such as polyethylene or polypropylene can be remarkably improved.

The content (ratio) of the above-mentioned ring-containing (meth)acrylate in all monomer units of the acrylic polymer (B) (the total amount of monomer components constituting the acrylic polymer (B)) is not particularly limited, It is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, with respect to the total amount (100% by weight) of the monomer components constituting the acrylic polymer (B). When content of the said ring-containing (meth)acrylate is 10 weight% or more, it is easy to improve foaming peeling resistance, and it is preferable. In addition, when the content is 90% by weight or less, the adhesive layer has moderate flexibility, and it is easy to improve the adhesive force, the level difference absorption, and the like, which is preferable.

Moreover, as the monomeric unit of the acrylic polymer (B), the (meth)acrylic acid alkyl ester having the above-mentioned linear or branched alkyl group includes, for example, methyl (meth)acrylate, Ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate ester, tert-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, (meth)acrylic acid Octyl ester, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, ( Isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate ester, pentadecyl (meth)acrylate, cetyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, (meth)acrylate The carbon number of the alkyl group, such as nonadecyl acrylate and eicosyl (meth)acrylate, is an alkyl (meth)acrylate having 1 to 20 carbon atoms, and the like. Among them, methyl methacrylate (MMA) is preferable in that the compatibility with the acrylic polymer (A) becomes favorable. In addition, the said alkyl (meth)acrylate can be used individually or in combination of 2 or more types.

Among the total monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)), the above-mentioned alkyl (meth)acrylate having a linear or branched alkyl group The content (ratio) is not particularly limited, but from the point of view of resistance to foaming and peeling, it is preferably 10% by weight or more ( For example, 10 to 90% by weight), more preferably 20 to 80% by weight, still more preferably 20 to 60% by weight. When the content is 10% by weight or more, it is particularly easy to improve the adhesive force to the adherend made of acrylic resin or polycarbonate, which is preferable.

As the monomer unit of the acrylic polymer (B), in addition to the above-mentioned ring-containing (meth)acrylate and (meth)acrylate alkyl having a linear or branched alkyl group, optionally Monomers (comonomers) copolymerized with these monomers. In addition, the content (ratio) of the above-mentioned copolymerizable monomer in all the monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)) is not particularly limited, and relative to The total amount (100% by weight) of the monomer components constituting the acrylic polymer (B) is preferably 49.9% by weight or less (for example, 0 to 49.9% by weight), more preferably 30% by weight or less. Moreover, a comonomer can be used individually or in combination of 2 or more types.

About the said comonomer (the said comonomer which comprises acrylic polymer (B)) which is the monomer unit of acrylic polymer (B), (meth)acrylic acid alkoxyalkane is mentioned, for example: base ester [eg, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, (meth)acrylic acid 3-methoxypropyl, (meth)acrylate 3-ethoxypropyl, (meth)acrylate 4-methoxybutyl, (meth)acrylate 4-ethoxybutyl, etc.]; containing Monomers of hydroxyl [for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate) [ For example, (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)propylene amide, N-butoxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, etc.]; amine group-containing monomers [for example, (meth)acrylate aminoethyl esters, dimethylaminoethyl (meth)acrylate, tert-butylaminoethyl (meth)acrylate, etc.]; cyano group-containing monomers [for example, acrylonitrile, methacrylonitrile, etc.]; containing Monomers containing sulfonic acid groups [for example, sodium vinylsulfonate, etc.]; monomers containing phosphoric acid groups [for example, 2-hydroxyethyl acryl phosphate, etc.]; monomers containing isocyanate groups [for example, isocyanato group 2-methacryloyloxyethyl cyanate, etc.], monomers containing imide groups [cyclohexylmaleimide, isopropylmaleimide, etc.], etc.

As described above, the acrylic polymer (B) preferably contains (meth)acrylic acid ester having a cyclic structure in the molecule and (meth)acrylic acid alkyl ester having a linear or branched alkyl group as a single Acrylic polymers of monomer units. Among them, an acrylic polymer containing a ring-containing (meth)acrylate and the above-mentioned (meth)acrylate having a linear or branched alkyl group as monomer units is preferable. In the above-mentioned acrylic polymer containing a ring-containing (meth)acrylate and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group as monomer units, relative to the constituent acrylic polymer The amount of the ring-containing (meth)acrylate in the total monomer component (100% by weight) of (B) is not particularly limited, but is preferably 10 to 90% by weight, more preferably 20 to 80% by weight. In addition, the content of the alkyl (meth)acrylate having a linear or branched alkyl group is not particularly limited, but is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and still more preferably 20 to 60% by weight.

Furthermore, as a particularly preferable specific structure of the acrylic polymer (B), (1) a ring selected from the group consisting of dicyclopentyl acrylate, dicyclopentyl methacrylate, cyclohexyl acrylate, and methacrylic acid can be mentioned. At least one monomer in the group consisting of hexyl ester, and (2) an acrylic polymer having methyl methacrylate as a monomer unit. (1) Dicyclopentyl acrylate, dicyclopentyl methacrylate, cyclohexyl acrylate among all monomer units of acrylic polymer (B) in the above-mentioned particularly preferred acrylic polymer (B) The content of ester and cyclohexyl methacrylate (in the case of containing two or more kinds, the total amount of these) is higher than the total amount (100% by weight) of the monomer components constituting the acrylic polymer (B). It is preferably 30 to 70% by weight, and (2) the content of methyl methacrylate is preferably 30 to 70% by weight. However, the said acrylic polymer (B) is not limited to the said specific structure.

The acrylic polymer (B) can be obtained by polymerizing the above-mentioned monomer components by a known or conventional polymerization method. As a polymerization method of the said acrylic polymer (B), a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a polymerization method by active energy ray irradiation (active energy ray polymerization method) etc. are mentioned, for example. Among them, the block polymerization method and the solution polymerization method are preferable, and the solution polymerization method is more preferable.

In the polymerization of the acrylic polymer (B), various common solvents can be used. Examples of the solvent include: esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane, methylcyclohexane and the like Alkane and other alicyclic hydrocarbons; methyl ethyl ketone, methyl isobutyl ketone and other ketones and other organic solvents. In addition, such a solvent can be used individually or in combination of 2 or more types.

Furthermore, at the time of superposing|polymerizing an acrylic polymer (B), a well-known or usual polymerization initiator (for example, a thermal polymerization initiator, a photopolymerization initiator, etc.) can be used. In addition, a polymerization initiator can be used individually or in combination of 2 or more types.

As a thermal polymerization initiator, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile (AMBN), 2,2' -Azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis(4-methoxy-2,4 -Dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2 '-Azobis(2,4,4-trimethylpentane) and other azo initiators; benzyl peroxide, tertiary butyl hydroperoxide, di-tertiary butyl peroxide, peroxide tert-butyl benzoate, dicumyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis A peroxide-based initiator such as (tert-butylperoxy)cyclododecane and the like. Furthermore, in the case of performing solution polymerization, it is preferable to use an oil-soluble polymerization initiator. Moreover, a thermal polymerization initiator can be used individually or in combination of 2 or more types.

The usage-amount of the said thermal polymerization initiator is not specifically limited, For example, it is 100 weight with respect to all monomeric units of acrylic polymer (B) (total amount of monomer components constituting acrylic polymer (B)) part is 0.1 to 15 parts by weight.

In addition, the photopolymerization initiator is not particularly limited, and for example, the same photopolymerization initiator as the photopolymerization initiator used in the polymerization of the acrylic polymer (A) mentioned above can be mentioned. agent. The usage-amount of the said photoinitiator is not specifically limited, It can select suitably.

At the time of superposition|polymerization of the said acrylic polymer (B), in order to adjust a molecular weight (specifically, to adjust a weight average molecular weight to 1000-30000), a chain transfer agent can be used. As said chain transfer agent, 2-mercaptoethanol, alpha-thioglycerol, 2, 3- dimercapto- 1-propanol, octyl mercaptan, tertiary nonyl mercaptan, dodecyl, for example, can be mentioned. Thiol (lauryl mercaptan), tri-dodecyl mercaptan, glycidyl mercaptan, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate , butyl thioglycolate, tert-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, sulfur Dodecyl glycolate, thioglycolic acid ester of ethylene glycol, thioglycolic acid ester of neopentyl glycol, thioglycolic acid ester of pentaerythritol, α-methylstyrene dimer, etc. Among them, from the viewpoint of suppressing whitening of the adhesive sheet due to humidification, α-thioglycerol and methyl thioglycolate are preferred, and α-thioglycerol is particularly preferred. In addition, a chain transfer agent can be used individually or in combination of 2 or more types.

The content (amount of use) of the above chain transfer agent is not particularly limited, but is more than 0.1-20 weight part is preferable, 0.2-15 weight part is more preferable, 0.3-10 weight part is still more preferable, 0.5-5 weight part is still more preferable, 0.75-3 weight part is especially preferable. By making the content (amount of use) of the chain transfer agent in the above-mentioned range, an acrylic polymer whose weight average molecular weight is controlled to be 1,000 to 30,000 can be easily obtained.

The weight average molecular weight (Mw) of the acrylic polymer (B) is 1,000-30,000, preferably 1,000-20,000, more preferably 1,500-10,000, still more preferably 2,000-8,000, particularly preferably 4,000-6,000. Since the weight-average molecular weight of the acrylic polymer (B) is 1,000 or more, the adhesive force and the holding properties are improved, and the foaming and peeling resistance is improved. On the other hand, since the weight-average molecular weight of the acrylic polymer (B) is 30,000 or less, the adhesive force is easily improved, and the foaming and peeling resistance is improved.

The weight average molecular weight (Mw) of the said acrylic polymer (B) can be calculated|required by polystyrene conversion by GPC method. For example, the measurement can be performed under the following conditions using a high-speed GPC apparatus "HPLC-8120GPC" manufactured by Tosoh Co., Ltd. Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000 Solvent: Tetrahydrofuran Flow rate: 0.6 ml/min

The glass transition temperature (Tg) of the acrylic polymer (B) is not particularly limited, but is preferably 20 to 300°C, more preferably 30 to 250°C, more preferably 40 to 200°C, and still more preferably 50 ~150°C, more preferably 60 to 120°C, still more preferably 70 to 100°C, particularly preferably 80 to 90°C. When the glass transition temperature of the acrylic polymer (B) is 20° C. or higher, it is easy to improve the foaming peeling resistance, which is preferable. In addition, if the glass transition temperature of the acrylic polymer (B) is 300° C. or lower, the adhesive layer has moderate flexibility, and it is easy to obtain good adhesive force or good level difference absorption, and it is easy to obtain excellent adhesion reliability. , so it is better.

The glass transition temperature (Tg) of the said acrylic polymer (B) is the glass transition temperature (theoretical value) represented by the formula of the said FOX. As Tg of the homopolymer of the monomer which comprises the said acrylic polymer (B), the value described in the following Table 1 can be employ|adopted. In addition, as Tg of the homopolymer of the monomer not described in Table 1, the numerical value described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be used. Furthermore, as the Tg of the homopolymer of the monomer not described in the above-mentioned document, the value obtained by the above-mentioned measurement method (the peak top temperature of tan δ obtained by the viscoelasticity test) can be used.

[Table 1] Table 1 composition Tg[℃] Homopolymer Methyl Methacrylate (MMA) 105 Dicyclopentyl methacrylate (DCPMA) 175 Dicyclopentyl acrylate (DCPA) 120 Isoyl methacrylate (IBXMA) 173 Isoyl Acrylate (IBXA) 97 Cyclohexyl Methacrylate (CHMA) 66 1-Adamantyl methacrylate (ADMA) 250 1-Adamantyl Acrylate (ADA) 153 Copolymer DCPMA/MMA=60/40 144 Furthermore, the copolymer of "DCPMA/MMA=60/40" in Table 1 means a copolymer of 60 parts by weight of DCPMA and 40 parts by weight of MMA.

When the adhesive composition of the present invention contains the acrylic polymers (A) and (B), the content of the acrylic polymer (B) is not particularly limited, and is based on 100 parts by weight of the above acrylic polymer (A). , preferably 1 to 30 parts by weight, more preferably 2 to 20 parts by weight, still more preferably 2 to 10 parts by weight, still more preferably 2 to 5 parts by weight. That is, the content of the acrylic polymer (B) in the above-mentioned adhesive composition is not particularly limited, but is preferably 1 to 30 parts by weight relative to 100 parts by weight of all monomer units of the above-mentioned acrylic polymer (A) , more preferably 2 to 20 parts by weight, still more preferably 2 to 10 parts by weight, still more preferably 2 to 5 parts by weight. The content of the acrylic polymer (B) in the adhesive composition of the present invention is not particularly limited, for example, relative to 100 parts by weight of the monomer mixture, preferably 1-30 parts by weight, more preferably 2-20 parts by weight The weight part is more preferably 2 to 10 parts by weight, still more preferably 2 to 5 parts by weight. When the content of the acrylic polymer (B) is 1 part by weight or more, excellent adhesiveness and excellent foaming peeling resistance are easily obtained, which is preferable. Moreover, when content of an acrylic polymer (B) is 30 weight part or less, it is easy to obtain excellent transparency and adhesive reliability, and it is preferable.

It does not specifically limit as a manufacturing method of the said adhesive composition containing an acrylic polymer (A) and (B). For example, if necessary, in the mixture of the monomer components constituting the acrylic polymer (A) or the partial polymer of the mixture of the monomer components constituting the acrylic polymer (A) (monomers constituting the acrylic polymer (A) An acrylic polymer (B), an additive, etc. are added to a mixture or its partial polymer), and it mixes, and the said adhesive composition is produced by this.

[1-9. Rubber-based polymer] As another preferred embodiment of the adhesive composition of the present invention, a rubber-based adhesive composition containing a rubber-based polymer as a main component can be exemplified. Examples of the rubber-based polymer include: natural rubber; styrene butadiene rubber (SBR); polyisoprene (PIP); polyisobutylene (PIB); Butene-based polymers with formula- or trans-2-butene) and/or 2-methylpropene (isobutylene) as main monomers; A-B-A type block copolymer rubbers and their hydrogenated products, such as styrene-butyl Diene-styrene block copolymer rubber (SBS), styrene-isoprene-styrene block copolymer rubber (SIS), styrene-isobutylene-styrene block copolymer rubber (SIBS), benzene Ethylene-ethylene/isoprene-styrene block copolymer rubber (SVIS), styrene-ethylene-butylene-styrene block copolymer rubber (SEBS) as hydride of SBS, hydride as SIS Various rubber-based polymers such as styrene-ethylene-propylene-styrene block copolymer rubber (SEPS). These rubber-based polymers may be used alone or in combination of two or more.

The adhesive composition of the present invention may contain inorganic fine particles, organic fine particles, and base polymers in addition to the above-mentioned base polymer from the viewpoint of further lowering the dielectric constant and lowering the dielectric loss in the high frequency band. These polymer materials may be contained alone or in combination of two or more. As the inorganic fine particles and organic fine particles, those exhibiting insulating properties (insulating fillers) are preferred from the viewpoint of lowering the dielectric constant and lowering the dielectric loss in the high frequency band.

[1-10. Inorganic fine particles] The inorganic fine particles that can be formulated in the adhesive composition of the present invention are not particularly limited, and examples thereof include metal oxides such as silicon dioxide, aluminum oxide, zirconium oxide, and titanium oxide; aluminum borate, aluminum hydroxide, etc. Metal salts, minerals such as mica, inorganic fine particles having a hollow structure such as hollow nano-silica, etc., may be used alone or in combination of two or more.

The above-mentioned inorganic fine particles are preferably those subjected to surface treatment from the viewpoint of dispersibility in the base polymer. As a surface treatment agent, a well-known or conventional thing can be used without limitation, For example, a silane coupling agent, a titanium coupling agent, an organic acid, a polyol, a polysiloxane, etc. are mentioned, Preferably it is a silane coupling agent. As a silane coupling agent, vinyltrimethoxysilane, vinyltriethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethylsilane may, for example, be mentioned. Oxysilane, methylvinyldiethoxysilane, vinyltris(2-methoxy)silane, vinyltriacetoxysilane, 2-methacryloyloxyethyltriethoxysilane , 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxy-propylmethyldimethoxysilane , Triethoxyphenylsilane, trimethoxyphenylsilane, dimethoxydiphenylsilane, methyldiethoxyphenylsilane, dimethoxymethylphenylsilane, etc.

The particle size (D50) of the above-mentioned inorganic fine particles is not particularly limited, but is preferably 1 to 100 from the viewpoints of low dielectric constant, low dielectric loss, and transparency of the adhesive composition in high frequency bands. nm, more preferably 5 to 80 nm, still more preferably 10 to 50 nm. In addition, the above-mentioned central particle diameter means the particle diameter (median diameter) at 50% of the cumulative value in the particle size distribution measured by the laser diffraction/scattering method.

When the adhesive composition of the present invention contains inorganic fine particles, the content thereof is not particularly limited, and is considered from the viewpoints of low dielectric constant, low dielectric loss, and transparency of the adhesive composition in high frequency bands. In other words, relative to the base polymer (100 parts by weight), it is usually 0.01 to 30 parts by weight, preferably 0.05 to 25 parts by weight, more preferably 0.1 to 20 parts by weight, further preferably 0.15 to 10 parts by weight, especially It is preferably 0.2 to 5 parts by weight.

[1-11. Organic Microparticles] There are no particular limitations on the organic fine particles that can be formulated in the adhesive composition of the present invention, and examples thereof include styrene-based resins, acrylic-based resins, polysiloxane-based resins, acrylic-styrene-based resins, vinyl chloride resin, vinylidene chloride-based resin, amide-based resin, urethane-based resin, phenol-based resin, styrene-conjugated diene-based resin, acrylic-conjugated diene-based resin, olefin-based resin, Polymers such as fluorine-based resins; or microparticles comprising cross-linked products of these polymers; and micro-particles formed by these polymers/polymer cross-linked bodies to have a hollow structure, etc., these can be used alone Or use two or more in combination.

The particle diameter (D50) of the above-mentioned organic fine particles is not particularly limited, but is preferably 1 to 100 from the viewpoints of low dielectric constant, low dielectric loss, and transparency of the adhesive composition in high frequency bands. nm, more preferably 5 to 80 nm, still more preferably 10 to 50 nm. In addition, the above-mentioned central particle diameter means the particle diameter (median diameter) at 50% of the cumulative value in the particle size distribution measured by the laser diffraction/scattering method.

When the adhesive composition of the present invention contains organic fine particles, the content thereof is not particularly limited, and is considered from the viewpoints of low dielectric constant, low dielectric loss, and transparency of the adhesive composition in high frequency bands. In other words, relative to the base polymer (100 parts by weight), it is usually 0.01 to 30 parts by weight, preferably 0.05 to 25 parts by weight, more preferably 0.1 to 20 parts by weight, further preferably 0.15 to 10 parts by weight, especially It is preferably 0.2 to 5 parts by weight.

[1-12. Polymer material] The polymer material that can be formulated in the adhesive composition of the present invention is not particularly limited, but preferably one with low dielectric constant and low dielectric loss and compatibility with the base polymer, such as: Fluorine resin, fluorine rubber, polyethylene, polypropylene, polystyrene, polycarbonate, nor-ene resin or addition copolymerization resin with olefins, polyphenylene ether, bismaleimide-tris - Resins, polyetherimide, polyimide, polyetheretherketone (PEEK), liquid crystal polymers, rubber-elastomers, hydrogenated polyolefin resins, terpenes, isoprene, terpene phenol resins, aromatics As for the group-modified terpene resin and these hydrogenated resins, these can be used alone or in combination of two or more.

When the adhesive composition of the present invention contains a polymer material, its content is not particularly limited, from the viewpoints of low dielectric constant, low dielectric loss, and transparency of the adhesive composition in high frequency bands For the base polymer (100 parts by weight), it is usually 0.01 to 50 parts by weight, preferably 0.05 to 40 parts by weight, more preferably 0.1 to 30 parts by weight, and still more preferably 0.15 to 20 parts by weight, 0.2-10 weight part is especially preferable.

[1-13. Rust inhibitor] The adhesive composition of the present invention preferably further contains a rust inhibitor. When a rust inhibitor is contained in the adhesive layer, it is preferable in that an excellent anticorrosion effect for antenna elements and metal wiring can be obtained.

Rust inhibitors are compounds that prevent rust or corrosion of metals. Although it does not specifically limit as a rust inhibitor, For example, an amine compound, a benzotriazole type compound, a nitrite, etc. are mentioned. In addition, ammonium benzoate, ammonium phthalate, ammonium stearate, ammonium palmitate, ammonium oleate, ammonium carbonate, dicyclohexylamine benzoate, urea, urotropine (urotropin), thiourea, phenyl carbamate, cyclohexylammonium N-cyclohexylcarbamate (CHC), etc. In addition, a rust inhibitor can be used individually or in combination of 2 or more types.

Examples of the above-mentioned amine compounds include hydroxyl-containing amine compounds such as 2-amino-2-methyl-1-propanol, monoethanolamine, monoisopropanolamine, diethylethanolamine, ammonia, or ammonia water; Cyclic amines such as cyclohexylamine; cyclic alkylamine compounds such as cyclohexylamine; linear alkylamines such as 3-methoxypropylamine, etc. Moreover, as a nitrite, dicyclohexylammonium nitrite (DICHAN), diisopropylammonium nitrite (DIPAN), sodium nitrite, potassium nitrite, calcium nitrite, etc. are mentioned, for example.

The content of the rust inhibitor is not particularly limited, but is preferably 0.02 to 15 parts by weight relative to 100 parts by weight of the base polymer. When the said content is 0.02 weight part or more, favorable corrosion prevention performance is easy to be obtained, and it is preferable. On the other hand, when the said content is less than 15 weight part, it is easy to ensure transparency, and it is easy to ensure adhesion reliability, such as foaming peeling resistance, and it is preferable.

Among them, the above-mentioned rust inhibitor is preferably a benzotriazole-based compound in terms of compatibility and transparency with respect to the base polymer. In particular, the above-mentioned rust inhibitor is preferably benzotrian in terms of good balance and high level of properties of adhesion reliability, transparency, and corrosion resistance, and excellent appearance can be obtained. azole compounds.

The content of the benzotriazole-based compound is not particularly limited, but is preferably 0.02 to 3 parts by weight, more preferably 0.02 to 2.5 parts by weight, and still more preferably 0.02 to 2 parts by weight relative to 100 parts by weight of the base polymer. Since the amount of the benzotriazole-based compound is below a certain level, adhesion reliability such as resistance to foaming and peeling can be surely ensured, and an increase in the haze of the adhesive sheet can also be surely prevented.

(其中，於上述式(6)中，R ²及R ³相同或不同，R ²為苯環上之取代基，表示碳數1～6之烷基、碳數1～6之烷氧基、碳數6～14之芳基、胺基、單或二C _1-10烷基胺基、胺基-C _1-6烷基、單或二C _1-10烷基胺基-C _1-6烷基、巰基、碳數1～6之烷氧基羰基、或碳數1～6之烷氧基等取代基，n為0～4之整數，於n為2以上之情形時，n個R ²可相同，亦可不同，R ³表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基、碳數6～14之芳基、胺基、單或二C _1-10烷基胺基、胺基-C _1-6烷基、單或二C _1-10烷基胺基-C _1-6烷基、巰基、碳數1～12之烷氧基羰基、或碳數1～12之烷氧基等取代基) The above-mentioned benzotriazole-based compound is not particularly limited as long as it is a compound having a benzotriazole skeleton, and from the viewpoint of obtaining a more excellent anti-corrosion effect, it is preferably a compound having the following formula (6) represented structure. [hua 7]

(wherein, in the above formula (6), R ² and R ³ are the same or different, and R ² is a substituent on the benzene ring, representing an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, Aryl, amine group, mono- or di-C _1-10 alkyl amine group, amino-C _1-6 alkyl group, mono- or di-C _1-10 alkyl amine group-C _1-6 with carbon number of 6-14 Substituents such as alkyl group, mercapto group, alkoxycarbonyl group having 1 to 6 carbon atoms, or alkoxy group having 1 to 6 carbon atoms, n is an integer of 0 to 4, and when n is 2 or more, n R ² may be the same or different, and R ³ represents a hydrogen atom, an alkyl group with 1 to 12 carbon atoms, an alkoxy group with a carbon number of 1 to 12, an aryl group with 6 to 14 carbon atoms, an amine group, a single or two C _{1 -10} alkylamino group, amino group-C _1-6 alkyl group, mono- or di-C _1-10 alkylamino group-C _1-6 alkyl group, mercapto group, alkoxycarbonyl group with 1 to 12 carbon atoms, or Substituents such as alkoxy with 1 to 12 carbon atoms)

From the viewpoint of obtaining a more excellent anti-corrosion effect, R ² is preferably an alkyl group having 1 to 3 carbon atoms, an alkoxycarbonyl group, or the like, and more preferably a methyl group or the like. Moreover, n is preferably 0 or 1. From the same viewpoint, R ³ is preferably a hydrogen atom, a mono- or di-C _1-10 alkylamino-C _1-6 alkyl group, or the like, more preferably a hydrogen atom, a di-C _1-8 alkyl group Amino C _1-4 alkyl, etc.

[1-14. Silane coupling agent] The adhesive composition of the present invention preferably further contains a silane coupling agent. When a silane coupling agent is contained in an adhesive bond layer, it is preferable at the point which is easy to obtain the excellent adhesion|attachment to glass (especially excellent adhesion reliability to glass under high temperature and high humidity).

It does not specifically limit as said silane coupling agent, However, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane may, for example, be mentioned. Silane, N-phenyl-aminopropyltrimethoxysilane, etc. Among them, γ-glycidoxypropyltrimethoxysilane is preferable. Furthermore, as said silane coupling agent, a commercial item, such as a brand name "KBM-403" (made by Shin-Etsu Chemical Co., Ltd.), can also be mentioned, for example. In addition, a silane coupling agent can be used individually or in combination of 2 or more types.

The content of the above-mentioned silane coupling agent is not particularly limited, but from the viewpoint of improving the bonding reliability to glass, it is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 part by weight with respect to 100 parts by weight of the base polymer .

[1-15. Cross-linking agent] The adhesive composition of the present invention preferably further contains a crosslinking agent. When a crosslinking agent is contained in the adhesive composition, the base polymer is crosslinked to increase the gel fraction, and it becomes easy to improve the foaming and peeling resistance. For example, since the acrylic polymer can be crosslinked and the control of the gel fraction can be easily increased, the resistance to foaming and peeling can be easily improved. As the above-mentioned crosslinking agent, for example, in addition to a cyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, and a peroxide-based crosslinking agent, a urea-based crosslinking agent, a metal alkane, Oxide-based cross-linking agent, metal chelate-based cross-linking agent, metal salt-based cross-linking agent, carbodiimide-based cross-linking agent, oxazoline-based cross-linking agent, aziridine-based cross-linking agent, amine Department of cross-linking agents, etc. Among them, when the above-mentioned adhesive layer is an adhesive composition containing an acrylic polymer as a base polymer, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, an epoxy-based A crosslinking agent, more preferably an isocyanate-based crosslinking agent. In addition, a crosslinking agent can be used individually or in combination of 2 or more types.

As said isocyanate type crosslinking agent (polyfunctional isocyanate compound), 1, 2- ethylidene diisocyanate, 1, 4- butylene diisocyanate, 1, 6- hexamethylene diisocyanate etc. are mentioned, for example Lower aliphatic polyisocyanates; cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylene diisocyanate and other cycloaliphatic polyisocyanates; 2,4-toluene diisocyanate Aromatic polyisocyanates such as isocyanates, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate, and the like. Moreover, as said isocyanate type crosslinking agent, for example, a trimethylolpropane/toluene diisocyanate adduct [Nippon Polyurethane Industry Co., Ltd. make, brand name "Coronate L"], trimethylolpropane can also be mentioned, for example. / Hexamethylene diisocyanate adduct [manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"], trimethylolpropane/xylylene diisocyanate adduct [manufactured by Mitsui Chemicals Co., Ltd., Commercial products such as the brand name "Takenate D-110N"].

As the epoxy-based crosslinking agent (polyfunctional epoxy compound), for example, N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1, 3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, Propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan Anhydrous sugar polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl tris(2-hydroxyethyl)isocyanurate , Resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Moreover, as said epoxy-type crosslinking agent, a Mitsubishi Gas Chemical Co., Ltd. make, brand name "Tetrad C" etc. are also mentioned, for example.

The content of the crosslinking agent in the above-mentioned adhesive composition is not particularly limited. For example, when the above-mentioned adhesive composition contains an acrylic polymer as a base polymer, with respect to 100 parts by weight of the acrylic polymer, Preferably it is 0.001-10 weight part, More preferably, it is 0.01-5 weight part. When the content of the crosslinking agent is 0.001 part by weight or more, it is easy to improve the resistance to foaming and peeling, which is preferable. On the other hand, if the content of the crosslinking agent is 10 parts by weight or less, the adhesive layer has moderate flexibility, and it is easy to improve the adhesive force, which is preferable.

[1-16. Additives] The adhesive composition of the present invention may contain antioxidants, cross-linking accelerators, adhesion-imparting resins (rosin derivatives, polyterpene resins, oil-soluble phenols, etc.), anti-oxidants, etc. Well-known additives such as aging agents, colorants (pigments or dyes, etc.), ultraviolet absorbers, chain transfer agents, plasticizers, softeners, surfactants, and antistatic agents. In addition, such an additive can be used individually or in combination of 2 or more types.

When the adhesive composition of the present invention contains an adhesion-imparting agent, the content thereof is preferably 0.01 part by weight or more with respect to 100 parts by weight of the base polymer from the viewpoint of imparting moderate adhesiveness, more preferably to be 0.05 part by weight or less. Moreover, from a viewpoint of preventing the peeling strength from becoming too high, it is preferable to set it as 50 weight part or less with respect to 100 weight part of base polymers, and it is more preferable to set it as 40 weight part or less. Also, in some aspects, when the adhesive force can be effectively controlled by the composition of the base polymer or Tg, the gel fraction of the adhesive, etc., it can also be compared without the use of an adhesive imparting agent. Well implemented.

[2. Adhesive layer] [2-1. Dielectric constant and dielectric loss of adhesive layer] The adhesive layer of the present invention is formed by the adhesive composition of the present invention, so it exhibits low dielectric constant and low dielectric loss under the millimeter wave of high frequency band (28-60 GHz). That is, the adhesive layer of the present invention can suppress radiation loss of millimeter waves.

The dielectric constant of the adhesive layer of the present invention at a frequency of 28 GHz is preferably 5 or less, more preferably 4.5 or less, still more preferably 4 or less, still more preferably 3.5 or less, and may also be 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, or 2.9 or less. The lower limit value of the dielectric constant at a frequency of 28 GHz is not particularly limited, but is preferably 2 or more, and may be 2.1 or more, or 2.2 or more.

The dielectric constant of the adhesive layer of the present invention at 28 GHz can be adjusted by adjusting the type of the base polymer, the composition of monomers, and the amount of additives constituting the adhesive composition for forming the adhesive layer. The type or content can be adjusted.

The dielectric loss of the adhesive layer of the present invention is controlled to be low at 28 GHz, and the radiation loss of millimeter waves can be suppressed. The dielectric loss of the adhesive layer of the present invention at a frequency of 28 GHz is preferably 0.05 or less, more preferably 0.045 or less, more preferably 0.04 or less, more preferably 0.035 or less, still more preferably 0.03 or less, and still more Preferably, it is 0.025 or less, and more preferably, it is 0.02 or less. The lower limit value of the dielectric loss at a frequency of 28 GHz is not particularly limited, but is preferably 0.0001 or more, and may be 0.0005 or more, or 0.001 or more.

The dielectric loss at 28 GHz of the adhesive layer of the present invention can be adjusted by adjusting the type of the base polymer, the composition of monomers, and the amount of additives constituting the adhesive composition for forming the adhesive layer. The type or content can be adjusted.

The adhesive layer of the present invention is preferably controlled to have a low dielectric constant at 60 GHz, which is preferable in terms of suppressing radiation loss of millimeter waves. The dielectric constant of the adhesive layer of the present invention at a frequency of 60 GHz is not particularly limited, but is preferably 5 or less, more preferably 4.5 or less, still more preferably 4 or less, still more preferably 3.5 or less, and may also be 3.4 below, below 3.3, below 3.2, below 3.1, below 3.0, or below 2.9. The lower limit value of the dielectric constant at a frequency of 60 GHz is not particularly limited, but is preferably 2 or more, and may be 2.1 or more, or 2.2 or more.

The dielectric constant of the adhesive layer of the present invention at 60 GHz can be adjusted by adjusting the type of the base polymer, the composition of monomers, and the amount of additives constituting the adhesive composition for forming the adhesive layer. The type or content can be adjusted.

In the adhesive layer of the present invention, the dielectric loss at 60 GHz is preferably controlled to be low, and the radiation loss of the millimeter wave can be suppressed. The dielectric loss of the adhesive layer of the present invention at a frequency of 60 GHz is not particularly limited, and is preferably 0.05 or less, more preferably 0.045 or less, more preferably 0.04 or less, more preferably 0.035 or less, and still more preferably 0.03 or less, more preferably 0.025 or less, particularly preferably 0.02 or less, and may be 0.019 or less, 0.018 or less, 0.017 or less, 0.016 or less, 0.015 or less, 0.014 or less, 0.013 or less, or 0.012 or less. The lower limit value of the dielectric loss at a frequency of 60 GHz is not particularly limited, but is preferably 0.0001 or more, and may be 0.0005 or more, or 0.001 or more.

The dielectric loss at 60 GHz of the adhesive layer of the present invention can be adjusted by adjusting the type of the base polymer, the composition of monomers, and the amount of additives constituting the adhesive composition for forming the adhesive layer. The type or content can be adjusted.

[2-2. Haze and total light transmittance of the adhesive layer] The adhesive layer of the present invention is transparent or has transparency. Therefore, the visibility and appearance through the above-mentioned adhesive layer are excellent. Thus, the adhesive layer of the present invention can be suitably used for optical applications.

The haze (according to JIS K7136) of the adhesive layer of the present invention is not particularly limited, but is preferably 1.2% or less, more preferably 1.1% or less, still more preferably 1.0% or less, still more preferably 0.9% or less, especially Preferably it is 0.8% or less. If the haze is 1.2% or less, excellent transparency or excellent appearance can be obtained, which is preferable. Furthermore, regarding the above-mentioned haze, for example, an adhesive layer (thickness: 100 μm) can be prepared, and after standing at a normal state (23° C., 50% RH) for at least 24 hours, it can be attached to a glass slide (e.g. A total light transmittance of 91.8% and a haze of 0.4%) were measured using a haze meter (manufactured by Murakami Color Technology Laboratory Co., Ltd., trade name "HM-150") using the obtained sample as a sample.

The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the adhesive layer of the present invention is not particularly limited, but is preferably 85% or more, more preferably 88% or more, and more preferably 89% or more, More preferably, it is 90% or more, more preferably 91% or more, and still more preferably 92% or more. If the total light transmittance is 85% or more, excellent transparency or excellent appearance can be obtained, which is preferable. Furthermore, regarding the above-mentioned total light transmittance, for example, an adhesive layer (thickness: 100 μm) can be formed, and after it is allowed to stand for at least 24 hours under normal conditions (23° C., 50% RH), in the case of having an isolation film When peeling it off, attach it to a glass slide (for example, one with a total light transmittance of 91.8% and a haze of 0.4%), using the obtained sample as a sample, using a hazemeter (Murakami Color Institute Co., Ltd. manufacture, trade name "HM-150") was measured.

The haze and total light transmittance of the adhesive layer of the present invention can be adjusted by adjusting the type of the base polymer, the monomer composition, and the type of additives constituting the adhesive composition for forming the adhesive layer. or content, etc.

[2-3. Gel fraction of adhesive layer] The gel fraction (ratio of insoluble components) of the adhesive layer of the present invention is not particularly limited, but is preferably 30 to 95%, more preferably 35 to 90%, still more preferably 40 to 85%, and still more 45 to 80%, preferably 50 to 75%. If the gel fraction is 30% or more, the cohesive force of the adhesive layer is improved, dents are not easily generated due to handling, and foaming or peeling at the interface with the adherend in a high-temperature environment is suppressed, and excellent results are easily obtained. It has better resistance to foaming and peeling. Furthermore, when the gel fraction is 95% or less, moderate flexibility can be obtained, adhesiveness and step followability are further improved, and foreign matter is not easily absorbed, which is preferable.

(gel fraction) Specifically, the said gel fraction (ratio of a solvent-insoluble component) is a value calculated by the following "measurement method of gel fraction", for example.

The adhesive layer collected from the self-adhesive sheet: about 0.1 g, wrapped in a porous tetrafluoroethylene sheet (trade name "NTF1122", manufactured by Nitto Denko Co., Ltd.) with an average pore diameter of 0.2 μm, tied with a kite string, and measured. The weight at this time was made into the weight (Z) before immersion. Furthermore, the weight before dipping is the total weight of the adhesive layer (the adhesive layer collected above), the tetrafluoroethylene sheet, and the kite string. In addition, the total weight of the tetrafluoroethylene sheet and the kite string was also measured in advance, and this weight was taken as the weight (Y) of the packaging bag. Then, the adhesive layer wrapped with tetrafluoroethylene sheet and bundled with kite string (referred to as "sample") was placed in a 50 ml container filled with ethyl acetate or toluene, and left to stand at 23° C. for 7 days. Then, the sample (after treatment with ethyl acetate or toluene) was taken out from the container, transferred to an aluminum beaker, dried in a dryer at 130° C. for 2 hours to remove ethyl acetate or toluene, and then the weight was measured to give This weight was taken as the weight after immersion (X). Then, the gel fraction was calculated according to the following formula. Gel fraction [% (weight %)]=(X-Y)/(Y-Z)×100

Furthermore, the gel fraction can be determined by, for example, the monomer composition, the weight average molecular weight, and the amount of the crosslinking agent used in the base polymer (eg, acrylic polymer, etc.) of the adhesive composition used to form the adhesive layer. Addition amount), the type or usage amount of other additives, etc.

[2-4. Storage elastic modulus of adhesive layer] The storage elastic modulus of the adhesive layer of the present invention at 25°C is not particularly limited, and is preferably 0.01 MPa or more, more preferably 0.02 MPa or more, further preferably 0.03 MPa or more, and further preferably 0.04 MPa or more, More preferably, it is 0.05 MPa or more, and particularly preferably 0.1 MPa or more. When the storage elastic modulus is 0.01 MPa or more, dents are not easily generated due to handling, and good adhesion reliability is easily obtained, which is preferable. In addition, from the viewpoint of step followability and foreign matter absorption, the storage elastic modulus of the adhesive layer at 25°C is preferably 5 MPa or less, more preferably 4.5 MPa or less, and still more preferably 4.0 MPa or less , more preferably 3.5 MPa or less, still more preferably 3.0 MPa or less, still more preferably 2.5 MPa or less, particularly preferably 2.0 MPa or less. The storage elastic modulus of the adhesive layer is obtained when the dynamic viscoelasticity is measured at a frequency of 1 Hz. The above-mentioned storage elastic modulus is the real part of the shear elastic modulus expressed as a complex number, and can be converted into tensile elastic modulus, etc. in consideration of the Poisson's ratio of the sample.

The storage elastic modulus of the adhesive layer of the present invention can be determined by the monomer composition of the base polymer (acrylic polymer), the weight average molecular weight, the use amount (addition amount) of the crosslinking agent, and the type or use amount of other additives. etc. to control.

[2-5. 300% tensile residual stress of the adhesive layer] The 300% tensile residual stress of the adhesive layer of the present invention is not particularly limited, but is preferably 2 to 24 N/cm ² , more preferably 2.5 to 2.5 20 N/cm ² , more preferably 3 to 16 N/cm ² . When the above-mentioned 300% tensile residual stress is 2 N/cm ² or more, good foaming peeling resistance can be easily obtained, which is preferable. In addition, when the 300% tensile residual stress is 24 N/cm ² or less, good stress relaxation properties can be obtained, and good step followability can be easily obtained, which is preferable.

If the adhesive sheet of the present invention has the above-mentioned adhesive layer in which the 300% tensile residual stress is within a specific range, it is easy to obtain excellent stress relaxation properties and to exhibit excellent step followability. For example, it can also follow a relatively large level difference (for example, a level difference with a height of about 45 μm, especially a level difference with a height of 20 to 50 μm).

The above-mentioned 300% tensile residual stress is the following value (N/cm ² ): in an environment of 23°C and 50% RH, the adhesive layer is stretched along the length direction to an elongation (strain) of 300%, and the elongation is maintained. The tensile load applied to the adhesive layer after 300 seconds from the end of stretching was obtained, and the tensile load was divided by the initial cross-sectional area of the adhesive layer (the cross-sectional area before stretching). Furthermore, the initial elongation of the adhesive layer was 100%.

The 300% tensile residual stress of the adhesive layer of the present invention can be determined by the monomer composition of the base polymer (acrylic polymer), the weight average molecular weight, the use amount (addition amount) of the crosslinking agent, the type of other additives or Control the usage, etc.

[2-6. Thickness of adhesive layer] The thickness of the adhesive layer of the present invention is not particularly limited, and is preferably 10-500 μm, more preferably 11-400 μm, further preferably 12-350 μm, particularly preferably 12-300 μm. When the thickness is more than a certain level, step followability and adhesion reliability are improved, which is preferable. Moreover, when the thickness is below a certain level, foreign matter during handling is difficult to absorb, and the manufacturability is particularly excellent, which is preferable.

[2-7. Manufacturing method of adhesive layer] It does not specifically limit as the manufacturing method of the said adhesive layer, For example, apply (coat) the said adhesive composition on a base material or a release liner, and dry, harden, or dry and harden as needed. . Hardening can be performed by irradiation of active energy rays, heating and drying, or the like.

In addition, the coating (coating) of the said adhesive composition can also use a well-known coating method. For example, a gravure roll coater, a reverse roll coater, a touch roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a notch roll coater can be used , Direct coating machine and other coating machines.

[3. Adhesive sheet] The pressure-sensitive adhesive sheet of the present invention is not particularly limited in other respects as long as it has the pressure-sensitive adhesive layer of the present invention.

The adhesive sheet of the present invention may be a double-sided adhesive sheet in which both sides become the surface of the adhesive layer, or a single-sided adhesive sheet in which only one side becomes the surface of the adhesive layer. Among them, a double-sided adhesive sheet is preferable from the viewpoint of bonding two members to each other. Furthermore, in this specification, when referring to the "adhesive sheet", a belt-shaped one, that is, an "adhesive tape" is also included. In addition, in this specification, the surface of an adhesive layer may be called "adhesion surface".

The adhesive sheet of the present invention may be provided with a release film (release liner) on the adhesive surface before use.

The adhesive sheet of the present invention may be an adhesive sheet without a base material (base material layer), that is, a so-called "base material-free type" (hereinafter sometimes referred to as a "base material-free adhesive sheet"), or may be It is a type of adhesive sheet with a base material (hereinafter sometimes referred to as "adhesive sheet with base material"). Examples of the above-mentioned base-free pressure-sensitive adhesive sheet include a double-sided pressure-sensitive adhesive sheet composed of only the above-mentioned pressure-sensitive adhesive layer, or a double-sided pressure-sensitive adhesive layer including the above-mentioned pressure-sensitive adhesive layer and other than the above-mentioned pressure-sensitive adhesive layer (sometimes referred to as the pressure-sensitive adhesive layer). "Other adhesive layer") double-sided adhesive sheet, etc. On the other hand, as an adhesive sheet with a base material, the adhesive sheet etc. which have the said adhesive bond layer on at least one side of a base material are mentioned. Among them, an adhesive sheet without a substrate (a double-sided adhesive sheet without a substrate) is preferable, and a double-sided adhesive sheet without a substrate composed of only the above-mentioned adhesive layer is more preferable. Moreover, it is also preferable that it is an adhesive sheet (double-sided adhesive sheet with a base material) which has the said adhesive bond layer on both surfaces of a base material. The adhesive layers on both sides of the above-mentioned double-sided adhesive sheet with base material can be the adhesive layers of the present invention, or one can be the adhesive layer of the present invention and the other can be other adhesive layers. In addition, the above-mentioned "substrate (substrate layer)" does not contain a release film that is peeled off when the adhesive sheet is used (attached).

When the adhesive sheet of the present invention is an adhesive sheet with a base material, radiation loss of millimeter waves caused by the base material will occur, so it is preferably an adhesive sheet without a base material. However, when the base material includes materials with low dielectric constant and low dielectric loss, it can also be an adhesive sheet attached to the base material.

[3-1. 180° peeling force of adhesive sheet] The 180° peel adhesion of the adhesive sheet of the present invention to the glass plate at a tensile speed of 300 mm/min (especially the 180° peel adhesion of the adhesive surface provided by the adhesive layer of the present invention to the glass plate) and It is not particularly limited, but from the viewpoint that the higher the adhesive force, the more sufficient adhesion to the antenna element can be obtained, it is preferably 3 N/20 mm or more, more preferably 3.5 N/20 mm or more, and more preferably 4 N /20 mm or more, more preferably 5 N/20 mm, more preferably 6 N/20 mm or more, more preferably 7 N/20 mm or more, more preferably 8 N/20 mm or more, and more Preferably it is 9 N/20 mm or more, more preferably 10 N/20 mm or more. When the 180° peel adhesion force of the adhesive sheet of the present invention to a glass plate at a tensile speed of 300 mm/min is a certain value or more, it is more excellent in the adhesion to glass and the suppression of bulging in the level difference. Furthermore, the upper limit of the 180° peel adhesion force of the adhesive sheet of the present invention is not particularly limited with respect to the tensile speed of the glass plate at 300 mm/min. For example, it is preferably 30 N/20 mm or less, more preferably It is 25 N/20 mm or less, more preferably 22 N/20 mm or less, particularly preferably 20 N/20 mm or less, and may be 19 N/20 mm or less, 18 N/20 mm or less, 17 N/20 mm or less, 16 N/20 mm or less, 15 N/20 mm or less, 14 N/20 mm or less, 13 N/20 mm or less, 12 N/20 mm or less, or 11 N/20 mm or less. The 180° peel adhesion force at a tensile speed of 300 mm/min for a glass plate can be obtained by the following measuring method of 180° peel adhesion force.

Although it does not specifically limit as said glass plate, For example, a brand name "soda lime glass #0050" (made by Matsunami Glass Co., Ltd.) can be mentioned. Moreover, alkali-free glass, chemically strengthened glass, etc. can also be mentioned.

(Measurement method of 180° peel adhesion) The adhesive surface of the adhesive sheet was attached to the body to be adhered, and it was crimped under the conditions of crimping with a 2 kg roller and one round trip, and aged at 23°C and 50% RH for 30 minutes. After aging, in accordance with JIS Z 0237, under the conditions of 23°C, 50% RH, under the conditions of a tensile speed of 300 mm/min and a peeling angle of 180°, the adhesive sheet was peeled off from the adherend, and the 180° peeling adhesion was measured. force (N/20 mm).

The 180° peeling adhesive force of the adhesive sheet of the present invention can be determined by the monomer composition of the base polymer (acrylic polymer), the weight average molecular weight, the use amount (addition amount) of the crosslinking agent, the type or use of other additives quantity etc. to be controlled.

[3-2. Thickness of adhesive sheet] The thickness (total thickness) of the adhesive sheet of the present invention is not particularly limited, but is preferably 10-500 μm, more preferably 11-400 μm, still more preferably 12-350 μm, more preferably 12-300 μm. When the thickness is more than a certain level, peeling is less likely to occur at the level difference portion, which is preferable. Moreover, it is preferable that it is easy to maintain the outstanding external appearance at the time of manufacture when the thickness is below a certain level. Furthermore, the thickness of the adhesive sheet of the present invention does not include the thickness of the release film.

[3-3. Haze and total light transmittance of the adhesive sheet] The haze (according to JIS K7136) of the adhesive sheet of the present invention is not particularly limited, but is preferably 1.2% or less, more preferably 1.1% or less, still more preferably 1.0% or less, further preferably 0.9% or less, especially Preferably it is 0.8% or less. If the haze is 1.2% or less, excellent transparency or excellent appearance can be obtained, which is preferable. Furthermore, regarding the above-mentioned haze, for example, the adhesive sheet can be left to stand for at least 24 hours under normal conditions (23° C., 50% RH), then peeled off when there is a separator, and attached to a glass slide ( For example, with a total light transmittance of 91.8% and a haze of 0.4%), a haze meter (manufactured by Murakami Color Technology Laboratory Co., Ltd., trade name "HM-150") was used as a sample for measurement. .

The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the adhesive sheet of the present invention is not particularly limited, but is preferably 85% or more, more preferably 88% or more, and further preferably 89% or more, More preferably, it is 90% or more, more preferably 91% or more, and still more preferably 92% or more. If the total light transmittance is 85% or more, excellent transparency or excellent appearance can be obtained, which is preferable. Furthermore, regarding the above-mentioned total light transmittance, for example, the adhesive sheet can be left standing for at least 24 hours under normal conditions (23° C., 50% RH), then peeled off when there is a separator, and attached to a glass slide. A sheet (for example, one with a total light transmittance of 91.8% and a haze of 0.4%) was used as a sample, and a hazemeter (manufactured by Murakami Color Institute Co., Ltd., trade name "HM-150") was used. to measure.

The haze and total light transmittance of the adhesive sheet of the present invention can be adjusted by adjusting the type of base polymer, the composition of monomers, the type or content of additives, and the type of substrates constituting the adhesive composition for forming the adhesive layer. or thickness, etc.

[3-4. Manufacturing method of adhesive sheet] The adhesive sheet of the present invention is not particularly limited, and is preferably produced according to a known or conventional production method. For example, when the adhesive sheet of the present invention is an adhesive sheet without a base material, it can be obtained by forming the above-mentioned adhesive layer on the release film by the above-mentioned method. In addition, when the adhesive sheet of the present invention is an adhesive sheet with a base material, it can be obtained by directly forming the above-mentioned adhesive layer on the surface of the base material (direct printing method), or by temporarily placing the adhesive layer on the surface of the base material. After the above-mentioned adhesive layer is formed on the separator, it is transferred (bonded) to the base material, whereby the above-mentioned pressure-sensitive adhesive layer is provided on the base material to obtain (transfer method).

[3-5. Other layers of adhesive sheet] The adhesive sheet of the present invention may have other layers in addition to the above-mentioned adhesive layer. Examples of other layers include other adhesive layers (adhesive layers other than the above-mentioned adhesive layers (adhesive layers other than the adhesive layers formed by the adhesive composition of the present invention)), intermediate layers, lower layers coating etc. Furthermore, the adhesive sheet of the present invention may have two or more other layers.

[3-6. Base material for adhesive sheet] The base material in the case where the adhesive sheet of the present invention is an adhesive sheet with a base material is not particularly limited, for example, various kinds of plastic films, anti-reflection (AR) films, polarizing plates, retardation plates, etc. optical film. As a material of the said plastic film etc., for example, polyester resins, such as polyethylene terephthalate (PET), (meth)acrylic resins, such as polymethyl methacrylate (PMMA), polycarbonate, etc. Ester, triacetyl cellulose (TAC), polyamide, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, ethylene-propylene copolymer, trade name "ARTON (cyclic Cyclic olefin-based polymers, manufactured by JSR Co., Ltd.)", trade names "ZEONOR (cyclic olefin-based polymers, manufactured by Nippon Zeon Co., Ltd.)" and other cyclic olefin-based polymers, fluorine-based polymers and other plastic materials. Furthermore, these plastic materials may be used alone or in combination of two or more. In addition, a hard coat layer, an anti-adhesion layer, an anti-reflection layer, an anti-static layer, an easy-bonding layer, a moisture-proof layer and the like can be appropriately formed on one or both sides of the above-mentioned substrate. A surface treatment layer with multiple functions. In addition, the above-mentioned "base material" is a part attached to the to-be-adhered body together with the adhesive layer when the pressure-sensitive adhesive sheet is attached to the to-be-adhered body. The release film (release liner) that is peeled off when the adhesive sheet is used (attached) is not included in the "substrate".

The above-mentioned base material is preferably transparent. The total light transmittance (according to JIS K7361-1) of the above-mentioned base material in the visible light wavelength region is not particularly limited, but is preferably 85% or more, more preferably 88% or more. Moreover, the haze of the above-mentioned base material (according to JIS K7136) is not particularly limited, but is preferably 1.2% or less, more preferably 1.1% or less, still more preferably 1.0% or less, still more preferably 0.9% or less, particularly preferably 0.8% or less. As such a transparent base material, non-alignment films, such as a PET film, a brand name "ARTON", a brand name "ZEONOR", etc. are mentioned, for example. In particular, the properties of the non-aligned film do not depend on the direction of the millimeter-wave electric field, which is preferable.

The thickness of the said base material is not specifically limited, For example, it is preferable that it is 12-500 micrometers. In addition, the said base material may have any form of a single layer and a multilayer. In addition, known and conventional surface treatments such as physical treatments such as corona discharge treatment, plasma treatment, and electron beam treatment, and chemical treatments such as primer treatment can be appropriately performed on the surface of the above-mentioned base material.

[3-7. Release film for adhesive sheet] The adhesive sheet of the present invention may be provided with a release film (release liner) on the adhesive surface before use. Furthermore, when the adhesive sheet of the present invention is a double-sided adhesive sheet, each adhesive surface can be protected by two separate sheets of release film, or can be wound by using a piece of release film that becomes a peeling side on both sides. Protected in roll form. The separator is used as a protective material for the adhesive layer, and peels off when it is attached to the adherend. Moreover, in the case where the adhesive sheet of the present invention is an adhesive sheet without a base material, the release film also functions as a support for the adhesive layer. In addition, it is not always necessary to provide a separator.

As said separator, a conventional release paper etc. can be used, and it does not specifically limit. For example, a base material having a release treatment layer, a low-adhesion base material containing a fluoropolymer, or a low-adhesion base material containing a non-polar polymer can be mentioned. As the base material having the above-mentioned release treatment layer, for example, a plastic film, paper, etc., which are surface-treated with release treatment agents such as polysiloxane-based, long-chain alkyl-based, fluorine-based, and molybdenum sulfide, can be exemplified. Examples of the fluorine-based polymer in the above-mentioned fluoropolymer-containing low-adhesion base material include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and tetrafluoroethylene-hexafluoroethylene. Fluoropropylene copolymer, chlorofluorovinylidene fluoride copolymer, etc. Moreover, as said nonpolar polymer, for example, olefin resins (for example, polyethylene, polypropylene, etc.) etc. are mentioned, polyester type base material (polyethylene terephthalate base material, polyethylene naphthalate-based substrates, polybutylene terephthalate-based substrates, etc.) and the like. Furthermore, the isolation film can be formed by a known or conventional method. Moreover, the thickness etc. of a separator are not specifically limited, either.

[3-8. Application of adhesive sheet, etc.] Since the adhesive sheet of the present invention has the adhesive layer of the present invention, it is excellent in adhesiveness and foaming and peeling resistance, and further, it is excellent in stress relaxation property and excellent in step followability. Therefore, the adhesion reliability, especially the adhesion reliability at high temperature, is excellent. Moreover, it is excellent in appearance.

Therefore, the adhesive sheet of the present invention is useful for laminating members whose interfaces are likely to foam at high temperatures. For example, polymethyl methacrylate resin (PMMA) may contain unreacted monomers, and it is easy to generate foaming caused by foreign matter at high temperature. In addition, polycarbonate (PC) is prone to outgassing of water and carbon dioxide at high temperatures. Since the adhesive sheet of the present invention is excellent in foaming and peeling resistance, it is also useful for a plastic adherend containing such a resin.

Moreover, the adhesive sheet of this invention is useful not only for the to-be-adhered body with a small linear expansion coefficient, but also for the to-be-adhered body with a large linear expansion coefficient. In addition, it does not specifically limit as a to-be-adhered body with a small linear expansion coefficient, For example, a glass plate (linear expansion coefficient: 0.3×10 ^-5 to 0.8×10 ^-5 /°C), polyparaphenylene An ethylene diformate base material (PET film, linear expansion coefficient: 1.5×10 ^-5 to 2×10 ^-5 /°C) and the like. In addition, as the adherend having a large linear expansion coefficient, it is not particularly limited, for example, a resin substrate having a large linear expansion coefficient can be exemplified, and more specifically, a polycarbonate resin substrate (PC , linear expansion coefficient: 7×10 ^-5 ～8×10 ^-5 /℃), polymethyl methacrylate resin substrate (PMMA, linear expansion coefficient: 7×10 ^-5 ～8×10 ^-5 /℃) , Cycloolefin polymer substrate (COP, coefficient of linear expansion: 6×10 ^-5 to 7×10 ^-5 /°C), trade name "ZEONOR" (manufactured by Nippon Zeon Co., Ltd.), trade name "ARTON" (JSR Co., Ltd.), etc.

The adhesive sheet of the present invention is useful for bonding an adherend with a small coefficient of linear expansion and an adherend with a large coefficient of linear expansion. Specifically, the adhesive sheet of the present invention can be preferably used for laminating glass substrates (eg, glass plates, chemically strengthened glass, glass lenses, etc.) and the above-mentioned resin substrates with large linear expansion coefficients.

As described above, the adhesive sheet of the present invention is useful for bonding between adherends of various materials, especially for bonding a glass adherend and a plastic adherend. Furthermore, the plastic bonded body can also be an optical film such as a plastic film with an ITO (indium and tin oxide) layer on the surface.

Furthermore, the adhesive sheet of the present invention is useful not only for an adherend having a smooth surface, but also for an adherend having a level difference on the surface. In particular, in the adhesive sheet of the present invention, even if at least one of the glass substrate and the resin substrate with the larger coefficient of linear expansion has a level difference on the surface, the glass substrate and the resin substrate with the larger coefficient of linear expansion are It is also useful for material bonding.

The adhesive sheet of the present invention can be preferably used in the manufacture of portable electronic devices. As the above-mentioned portable electronic equipment, for example, a mobile phone, a PHS (Personal Handy-phone System), a smart phone, a tablet (tablet computer), a mobile computer (mobile PC), a portable information device can be mentioned. Terminals (PDA), electronic notebooks, portable broadcast receivers such as portable TVs or portable radios, portable game consoles, portable audio-visual players, portable DVD (Digital Versatile Disc, Digital Versatile Disc) playback cameras, digital cameras and other cameras, camcorder-type camcorders, etc.

The adhesive sheet of the present invention can be preferably used, for example, for attaching components or modules constituting a portable electronic machine to each other, or for fixing components or modules constituting a portable electronic machine on a casing. More specifically, it can be exemplified: the cover glass or lens (especially the glass lens) is attached to the touch panel or the touch sensor, the antenna module, the cover glass or the lens (especially the glass lens) is attached to the case Fixing on the body, Fixing the display panel on the casing, Fixing the antenna module on the casing, Fixing the input device such as a sheet keyboard or touch panel on the casing, Protecting the information display panel Lamination with the casing, lamination of the casings with each other, lamination of the casing and decorative sheets, fixing or lamination of various components or modules constituting a portable electronic machine, etc. Furthermore, in this specification, the display panel refers to a structure including at least a lens (especially a glass lens) and a touch panel. In addition, the lens in this specification includes the concept of both a transparent body which exhibits the refraction effect of light and a transparent body which does not have the refraction effect of light. That is, the lens in this specification also includes a simple window panel that does not have a refraction effect.

Furthermore, the adhesive sheet of the present invention can be preferably used for optical applications. That is, the adhesive sheet of the present invention is preferably an optical adhesive sheet used for optical applications. More specifically, for example, it is preferably used for the purpose of bonding an optical member (for optical member bonding), or the production use of a product (optical product) using the above-mentioned optical member.

[3-9. Optical components] Examples of the optical member include an optical member including at least the adhesive sheet of the present invention and a substrate, and the substrate is provided with metal electrodes and wirings (for example, copper, silver, ITO wiring, etc.) on at least one side, and the substrate has the above-mentioned The adhesive layer of the present invention is adhered to one side of the metal electrode and the wiring. Furthermore, the above-mentioned adhesive sheet may be provided with a separator on the adhesive surface before use, and the above-mentioned adhesive sheet in the above-mentioned optical member is an adhesive sheet at the time of use, and therefore does not have a separator.

Furthermore, it is preferable that the said optical member has the said adhesive layer on the side opposite to the side which has the said metal electrode and the wiring of the said board|substrate, and it is more preferable that it has the said board|substrate on the side opposite to the side which has the said metal electrode and the wiring. The above-mentioned adhesive layer is attached thereon.

The material constituting the above-mentioned metal electrodes and wirings is not particularly limited, and examples thereof include titanium, silicon, niobium, indium, zinc, tin, gold, silver, copper, aluminum, cobalt, chromium, nickel, lead, iron, Palladium, platinum, tungsten, zirconium, tantalum, hafnium and other metals; ITO (indium and tin oxide), zinc oxide, tin oxide and other metal oxides. Furthermore, two or more kinds of these metals, metal oxides, or alloys containing these metals as a main component can also be exemplified. Among them, gold, silver, copper, and ITO are preferred in terms of conductivity, silver, copper, and ITO are more preferred in terms of conductivity and cost, and even more preferred in terms of transparency for ITO. That is, it is preferable that the said metal electrode and wiring are silver, copper, or ITO wiring, and it is especially preferable that it is ITO wiring. Furthermore, the same applies to the materials constituting the millimeter-wave antenna elements described below. The above-mentioned metal electrodes and wirings can be blackened by forming a film of nitride, oxide, sulfide, etc. of the metal by concealing the electrodes and/or wiring in order to prevent the reduction of visibility caused by the reflection of the metal. deal with.

Optical member refers to a material having optical properties (for example, polarization, light refraction, light scattering, light reflectivity, light transmittance, light absorption, light diffraction, optical rotation, visibility, electromagnetic wave transmittance, etc.). member. The substrate constituting the above-mentioned optical member is not particularly limited, and for example, a display device (image display device), a device (optical device) such as an input device, a substrate for an antenna module, or a substrate used for these devices may be mentioned. For example, polarizing plates, wavelength plates, retardation plates, optical compensation films, brightness enhancement films, light guide plates, reflective films, anti-reflection films, antenna substrates, hard coating films (for at least one side of plastic films such as PET films) Hard coating film), transparent conductive film (for example, plastic film with ITO layer on the surface (preferably ITO film such as PET-ITO, polycarbonate, cycloolefin polymer, etc.), etc.), design film, decoration Glass substrates such as film, surface protection plate, lens, lens, color filter, transparent substrate (glass sensor, glass display panel (LCD (liquid crystal display), etc.), glass plate with transparent electrodes, etc. etc.), or a substrate in which these are further laminated (these are sometimes collectively referred to as "functional films"), and the like. In addition, these films may have a metal nanowire layer, a conductive polymer layer, or the like. In addition, thin metal lines may be mesh-printed on these films. Moreover, these films may have an antenna element. In addition, the above-mentioned "plate" and "film" include forms such as plate shape, film shape, and sheet shape, respectively. For example, "polarizing film" includes "polarizing plate" and "polarizing sheet". In addition, "film" includes a film sensor and the like. The above-mentioned metal thin wires are concealed in order to prevent the reduction of visibility caused by the reflection of the metal, and for this purpose, a blackening treatment can be performed by forming a film such as nitride, oxide, or sulfide of the metal.

As said display apparatus, a liquid crystal display apparatus, an organic EL (electroluminescence) display apparatus, a PDP (plasma display panel), an electronic paper etc. are mentioned, for example. Moreover, as said input device, a touch panel etc. are mentioned. Moreover, as an antenna module, the millimeter-wave antenna etc. which are disclosed below can be mentioned.

The substrate constituting the optical member is not particularly limited, and examples thereof include substrates including glass, acrylic resin, polycarbonate, polyethylene terephthalate, cycloolefin polymer, metal thin film, and the like (for example, Sheet-like or film-like, plate-like substrates, etc.) Furthermore, the "optical member" in the present invention is as described above, and also includes a member (design film, decorative film, surface protection film, etc.) that maintains the visibility of the display device or the input device and plays a role of decoration or protection.

If the adhesive sheet of the present invention is an adhesive sheet with a base material, and the above-mentioned adhesive sheet constitutes a member having optical properties, the above-mentioned base material can be regarded as the above-mentioned substrate, and the above-mentioned optical member can also be regarded as the above-mentioned adhesive sheet of the present invention. material.

When the adhesive sheet of the present invention is a substrate-attached adhesive sheet and the above-mentioned functional film is used as the above-mentioned substrate, the adhesive sheet of the present invention can also be used as at least one side of the functional film An "adhesive-type functional film" having the above-mentioned adhesive layer.

[3-10. Millimeter wave antenna] The adhesive sheet of the present invention has an adhesive layer (the adhesive layer of the present invention) with low dielectric constant and low dielectric loss in high frequency bands such as millimeter waves, so that radiation loss of millimeter waves can be suppressed. Therefore, the adhesive sheet of the present invention is useful for bonding a member constituting an antenna for millimeter wave communication (millimeter wave antenna). In this specification, "millimeter wave communication" means communication in the frequency band of 20 GHz to 300 GHz.

As a member constituting a millimeter wave antenna, a substrate (hereinafter sometimes referred to as a "millimeter wave antenna") including an antenna element (hereinafter sometimes referred to as a "millimeter wave antenna element") for transmitting and receiving millimeter waves on at least one side can be mentioned. substrate").

As the millimeter wave antenna substrate, the plastic film used as the base material of the above-mentioned adhesive sheet can be exemplified. From the viewpoint of suppressing the radiation loss of the millimeter wave, a material with low dielectric constant and low dielectric loss is preferable, especially Cyclic olefin-based polymers such as trade name "ARTON (cyclic olefin-based polymer, manufactured by JSR Co., Ltd.)" and trade name "ZEONOR (cyclic olefin-based polymer, manufactured by Nippon Zeon Co., Ltd.)" are preferable.

The dielectric constant of the millimeter wave antenna substrate at 28 GHz and/or 60 GHz is preferably 2.0 to 5.0, more preferably 2.1 to 4.5, and still more preferably 2.2 to 4.0 from the viewpoint of suppressing the radiation loss of the millimeter wave. , more preferably 2.2-3.5, still more preferably 2.2-3.4, still more preferably 2.2-3.3, still more preferably 2.2-3.2, still more preferably 2.2-3.1, particularly preferably 2.2-3.0. In addition, the dielectric loss of the millimeter-wave antenna substrate at 28 GHz and/or 60 GHz is preferably 0.0001 to 0.05, more preferably 0.001 to 0.02, and still more preferably 0.002 from the viewpoint of suppressing the radiation loss of the millimeter wave. ~0.019, more preferably 0.003~0.018, still more preferably 0.004~0.017, still more preferably 0.005~0.016, still more preferably 0.006~0.015, still more preferably 0.007~0.014, still more preferably 0.008~0.013 , more preferably 0.009 to 0.012, particularly preferably 0.01 to 0.011.

The millimeter-wave antenna substrate is preferably transparent. The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the millimeter-wave antenna substrate is not particularly limited, preferably 85% or more, more preferably 88% or more, more preferably 89% or more, and more It is preferably 90% or more, more preferably 91% or more, and particularly preferably 92% or more. In addition, the haze of the millimeter-wave antenna substrate (according to JIS K7136) is not particularly limited, but is preferably 1.2% or less, more preferably 1.1% or less, more preferably 1.0% or less, further preferably 0.9% or less, especially Preferably it is 0.8% or less.

The thickness of the millimeter-wave antenna substrate is preferably 5 to 250 μm from the viewpoint of mounting the millimeter-wave antenna element and suppressing radiation loss of the millimeter-wave. Furthermore, the millimeter-wave antenna substrate may have either a single-layer or a multi-layer form. The surface of the millimeter-wave antenna substrate can be appropriately subjected to known and conventional surface treatments such as physical treatments such as corona discharge treatment and plasma treatment, chemical treatments such as primer treatment, and coating layers such as hard coat layers.

The millimeter-wave antenna element included in the millimeter-wave antenna substrate is not particularly limited as long as it can transmit and receive millimeter waves. From the viewpoint of efficiently receiving millimeter waves by portable communication devices such as smartphones, phase can be preferably used. array antenna. A phased array antenna is an antenna that arranges a plurality of antenna elements in an array, and controls the phase of each antenna element, thereby transmitting and receiving in the desired direction. That is, the phased array antenna can transmit or receive radio waves in a desired direction by electronically controlling the phase of each antenna element (beam steering) regardless of the direction of the antenna.

As the millimeter-wave antenna element, known antennas can be used without particular limitation, and examples include loop antenna structures, patch antenna structures, stacked patch antenna structures, patch antenna structures having parasitic elements, Inverted-F Antenna Structure, Slot Antenna Structure, Flat Inverted-F Antenna Structure, Monopole, Dipole, Helical Antenna Structure, Yagi (Yagi-Uda) Antenna Structure, Surface Area Body Waveguide Structure, Antenna elements of resonant elements formed by mixing designs etc. For different combinations of frequency bands, different types of millimeter-wave antenna elements can be used. From the viewpoint of efficiently receiving millimeter waves by a portable communication device such as a smartphone, a phased array antenna in which patch antenna elements are arranged in an array shape is preferable.

The material constituting the millimeter wave antenna element is not particularly limited, and examples thereof include titanium, silicon, niobium, indium, zinc, tin, gold, silver, copper, aluminum, cobalt, chromium, nickel, lead, iron, palladium, and platinum. , tungsten, zirconium, tantalum, hafnium and other metals; ITO (indium and tin oxide), zinc oxide, tin oxide and other metal oxides. Furthermore, what contains 2 or more types of these metals or metal oxides, or the alloy which has these metals as a main component can also be mentioned. Among them, silver, copper, and ITO are preferable from the viewpoint of electrical conductivity, and ITO is more preferable from the viewpoint of transparency and visibility. That is, it is particularly preferable that the above-mentioned millimeter wave antenna element contains ITO. In addition, when the antenna element contains metals such as silver and copper, the antenna element is concealed in order to prevent the reduction of visibility caused by the reflection of the metal. Blackening treatment is carried out on the film such as material.

In addition, the millimeter-wave antenna substrate may also include a transmission line path for transmitting the signals transmitted and received by the millimeter-wave antenna element to the transceiver circuit. Transmission line paths may include coaxial cable paths, microstrip transmission lines, stripline transmission lines, edge-bonded microstrip transmission lines, edge-bonded stripline transmission lines, waveguide structures (eg, coplanar waveguides or grounded ones) for transmitting signals in the millimeter-wave band. Coplanar waveguide), transmission lines formed by combinations of these types of transmission lines, etc. The material constituting the transmission line path is also not particularly limited, and the material constituting the millimeter wave antenna element can be used.

As a member constituting the millimeter-wave antenna, a cover member that is laminated on the millimeter-wave antenna substrate in order to protect the millimeter-wave antenna element arranged on the millimeter-wave antenna substrate can be mentioned. It does not specifically limit as a cover member, For example, optical films, such as glass and a plastic film, can be used. Examples of materials such as plastic films include polyester resins such as polyethylene terephthalate (PET), (meth)acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate, Triacetyl cellulose (TAC), polyamide, polyarylate, polyimide, transparent polyimide, polyvinyl chloride, polyvinyl acetate, fluorine-based resin, polyethylene, polypropylene, ethylene-propylene copolymer products, cyclic olefin polymers such as trade names "ARTON (cyclic olefin polymer, manufactured by JSR Co., Ltd.)", trade name "ZEONOR (cyclic olefin polymer, manufactured by Nippon Zeon Co., Ltd.)", etc. plastic material. Furthermore, these plastic materials may be used alone or in combination of two or more.

From the viewpoint of suppressing radiation loss of millimeter waves, the dielectric constant of the cover member at 28 GHz and or 60 GHz is preferably 2.0 to 5.0, more preferably 2.1 to 4.5, further preferably 2.2 to 4.0, More preferably, it is 2.2-3.5, More preferably, it is 2.2-3.4, More preferably, it is 2.2-3.3, More preferably, it is 2.2-3.2, More preferably, it is 2.2-3.1, More preferably, it is 2.2-3.0. In addition, the dielectric loss of the cover member at 28 GHz and or 60 GHz is preferably 0.0001-0.05, more preferably 0.001-0.02, still more preferably 0.002- 0.019, more preferably 0.003-0.018, more preferably 0.004-0.017, more preferably 0.005-0.016, more preferably 0.006-0.015, more preferably 0.007-0.014, and more preferably 0.008-0.013, More preferably, it is 0.009-0.012, More preferably, it is 0.01-0.011.

The above-mentioned cover member is preferably transparent. The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the cover member is not particularly limited, but is preferably 85% or more, more preferably 88% or more, more preferably 89% or more, and more preferably It is 90% or more, more preferably 91% or more, particularly preferably 92% or more. Moreover, the haze of the cover member (according to JIS K7136) is not particularly limited, but is preferably 1.2% or less, more preferably 1.1% or less, still more preferably 1.0% or less, still more preferably 0.9% or less, particularly preferably 0.8% or less.

The thickness of the cover member is preferably 0.025 to 1.5 mm from the viewpoint of suppressing radiation loss of millimeter waves. Furthermore, the cover member may have either a single-layer or a multi-layer form. The surface of the cover member may be appropriately subjected to known and conventional surface treatments such as physical treatments such as corona discharge treatment and plasma treatment, chemical treatments such as primer treatment, and coating layers such as hard coat layers.

The adhesive sheet of the present invention can be preferably used for the manufacture of millimeter-wave antennas used in portable communication equipment. As said portable communication apparatus, a mobile phone, a PHS, a smart phone, a tablet (tablet PC), a mobile computer (mobile PC), a portable information terminal (PDA), etc. are mentioned, for example.

The millimeter-wave antenna may have components other than the above-mentioned millimeter-wave antenna substrate, cover member, and adhesive sheet, for example, a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a brightness enhancement film, a light guide plate, a Anti-reflection film, hard coat film, transparent conductive film, design film, decorative film, surface protection plate, lens, lens, color filter, transparent substrate, or image display panel (such as liquid crystal display panel, organic EL panel, plasma display panel, etc.), etc. The image display panel may have a touch sensor.

The millimeter-wave antenna can be arranged at any position of the portable communication device, and specifically, it can be arranged on the front, back, and side surfaces of the portable communication device. Furthermore, the front surface of the portable communication device is the surface facing the user when the user uses the portable communication device. For example, the surface with the display panel corresponds to the front, and the casing corresponds to the back and side surfaces. Furthermore, the display panel refers to a structure including at least a lens (especially a glass lens) and a touch panel.

The size (range) of the millimeter-wave antenna is also not limited, and it may be formed on the entire surface of each surface of the portable communication device, or may be arranged on a part of it. In addition, the shape of the millimeter-wave antenna is not particularly limited, and may be, for example, a square, a circle, or a wire shape. Moreover, you may arrange|position in a frame shape. Furthermore, the number of millimeter-wave antennas arranged in the portable communication device is not limited, and it may be one, or a plurality of antennas may be arranged at arbitrary positions. When configuring a plurality of mmWave antennas, the sizes (ranges) may be the same or different. In order to improve visibility, a dummy pattern without a millimeter-wave antenna may be placed on a portion of a portable communication device where a millimeter-wave antenna is not placed.

The millimeter-wave antenna of the fifth aspect of the present invention is a millimeter-wave antenna having at least the above-mentioned adhesive sheet and substrate, as long as the above-mentioned substrate has an antenna element (millimeter-wave antenna element) on one side, and the above-mentioned substrate (millimeter-wave antenna substrate) ), the above-mentioned adhesive sheet may be adhered to the surface on the side having the above-mentioned antenna element, and is not particularly limited in other respects. Furthermore, the above-mentioned adhesive sheet in the millimeter-wave antenna of the present invention is an adhesive sheet at the time of use, and therefore does not have an isolation film.

As the millimeter-wave antenna, it is preferable to attach the millimeter-wave antenna substrate to other optical members (it is not necessary to have the above-mentioned adhesive sheet, but it is preferable to have it from the viewpoint of further suppressing the radiation loss of the millimeter-wave). constituted form. In addition, the above-mentioned other optical members may be singular or plural.

The aspect of bonding the millimeter-wave antenna of the present invention and the above-mentioned other optical members in the case of the above aspects is not particularly limited, for example: (1) The adhesive sheet of the present invention is used to attach the A state in which the millimeter-wave antenna substrate is bonded to the above-mentioned other optical members; (2) A state in which the adhesive sheet of the present invention, which includes or constitutes the millimeter-wave antenna substrate, is bonded to the above-mentioned other optical members; (3) Through the present invention The state of attaching the millimeter-wave antenna substrate to the member other than the millimeter-wave antenna substrate with the adhesive tape; (4) the adhesive tape of the present invention including or constituting the millimeter-wave antenna substrate is attached to the member other than the millimeter-wave antenna substrate. form, etc. Furthermore, in the aspect (2) above, the adhesive sheet of the present invention is preferably a double-sided adhesive sheet whose base material is a millimeter-wave antenna substrate.

Next, a preferred embodiment of the millimeter-wave antenna of the present invention will be described with reference to the drawings. FIG. 1 shows a millimeter-wave antenna 1A. The millimeter-wave antenna 1A is a millimeter-wave antenna having at least an adhesive sheet 10 and a substrate serving as a millimeter-wave antenna substrate 11. The millimeter-wave antenna substrate 11 has a millimeter-wave antenna element 2 on one side. The adhesive sheet 10 is attached to the side of the millimeter-wave antenna substrate 11 having the millimeter-wave antenna element 2 .

FIG. 2 shows the millimeter-wave antenna 1B having the cover member 12 , the adhesive sheet 10 , and the millimeter-wave antenna substrate 11 in a state of being connected to each other in this order. The millimeter-wave antenna substrate 11 is provided with the millimeter-wave antenna element 2 on the side of the adhesive sheet 10 , and the adhesive sheet 10 is attached to the side of the millimeter-wave antenna substrate 11 with the millimeter-wave antenna element 2 . The cover member 12 is preferably glass, the millimeter-wave antenna substrate 11 is preferably COP in terms of low dielectric constant and low dielectric loss, and the millimeter-wave antenna element 2 is preferably copper, silver, or ITO.

3 shows the millimeter-wave antenna 1C, which includes a cover member 12 , an adhesive sheet 10 a , a millimeter-wave antenna substrate 11 , an adhesive sheet 10 b , and an image display panel 13 in a connected state in order. The millimeter-wave antenna substrate 11 is provided with the millimeter-wave antenna element 2 on the side of the adhesive sheet 10 a, and the adhesive sheet 10 a is attached to the side of the millimeter-wave antenna substrate 11 on the side with the millimeter-wave antenna element 2 . The cover member 12 is preferably glass. In terms of low dielectric constant and low dielectric loss, the millimeter-wave antenna substrate 11 is preferably COP. In terms of transparency and visibility, the millimeter-wave antenna element 2 It is preferably ITO or silver or copper which has been blackened with a film such as nitride, oxide, sulfide, etc. The adhesive sheet 10b may or may not be the adhesive sheet of the present invention, and is preferably the adhesive sheet of the present invention. The image display panel 13 may also have a touch sensor (not shown).

In the millimeter-wave antennas 1A to 1C of FIGS. 1 to 3 , the adhesive sheets 10 , 10 a , and preferably the adhesive sheet 10 b include the adhesive layer of the present invention with low dielectric constant and low dielectric loss in high frequency bands. , so the radiation loss of the millimeter wave can be suppressed, and the millimeter wave communication can be carried out efficiently. In addition, since millimeter wave communication can be performed efficiently, the antenna area can be reduced in size, and the antenna can be miniaturized. Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited by these examples at all.

[Example 1] 43 parts by weight of 2-ethylhexyl acrylate (2EHA), 43 parts by weight of isostearyl acrylate (ISTA), 12 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 4-hydroxy acrylate 0.035 parts by weight of a photopolymerization initiator (trade name "Irgacure 184", manufactured by BASF), and a photopolymerization initiator (trade name "Irgacure 651", BASF) were prepared in 1 part by weight of the monomer mixture of butyl ester (4HBA). Company) 0.035 parts by weight, irradiated with ultraviolet light until the viscosity (BH viscometer No.5 rotor, 10 rpm, measurement temperature 30 ° C) reached about 20 Pa s, and obtained a prepolymer in which a part of the above monomer components have been polymerized combination. Next, 0.075 parts by weight of hexanediol diacrylate (HDDA) and 0.3 parts by weight of a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd.) were added to 100 parts by weight of the prepolymer composition. parts and mixed to obtain an adhesive composition (pre-hardening composition).

The above-mentioned adhesive composition was coated on a polyethylene terephthalate (PET) release film (trade name "MRF50", manufactured by Mitsubishi Chemical Co., Ltd.) so that the final thickness (thickness of the adhesive layer) was 25 μm. ) to form a coating layer (adhesive composition layer). Next, a PET separator (trade name "MRF38", manufactured by Mitsubishi Chemical Co., Ltd.) was placed on the above-mentioned coating layer, and the coating layer was covered to block oxygen. Then, a laminate of MRF50/coating layer (adhesive composition layer)/MRF38 was obtained. Next, ultraviolet rays with an illuminance of 5 mW/cm ² were irradiated from the upper surface (MRF38 side) of the laminate with a black light lamp (manufactured by Toshiba Corporation) for 300 seconds to this laminate. Furthermore, the drying process was performed for 2 minutes with a 90 degreeC dryer, and the residual monomer was volatilized. Then, a substrate-free double-sided adhesive sheet composed of only the adhesive layer and both sides of the adhesive layer being protected by the release film was obtained.

[Example 2] Except for the use of 25 parts by weight of 2-ethylhexyl acrylate (2EHA), 62 parts by weight of lauryl acrylate (LA), 8 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 4-hydroxybutyl acrylate A double-sided adhesive sheet without a substrate was obtained in the same manner as in Example 1, except that the monomer mixture of 5 parts by weight of ester (4HBA) was used to obtain the prepolymer composition.

[Example 3] 100 parts by weight of polyisobutylene (trade name "OPPANOL N80", Mw: 1,050,000, Mn: 440,000, Mw/Mn: 2.4, manufactured by BASF Corporation) and fully hydrogenated terpene phenol (softening point: 135° C., Hydroxyl value: 22 parts by weight of fully hydrogenated terpene phenol of 160 was prepared in toluene to prepare an adhesive composition (solution) with a solid content of 13% by weight. The obtained adhesive composition (solution) was coated on a PET separator (trade name "MRF50", manufactured by Mitsubishi Chemical Co., Ltd.) so that the final thickness (thickness of the adhesive layer) was 50 μm to form Coating layer (adhesive composition layer). Then, the coating layer was dried at 130° C. for 5 minutes to form an adhesive layer, and an adhesive sheet with a thickness of the adhesive layer of 50 μm was produced. Moreover, a PET separator (trade name "MRF38", manufactured by Mitsubishi Chemical Co., Ltd.) was attached to the adhesive surface of the adhesive sheet so that the peeling-treated surface was in contact with the above-mentioned adhesive layer. A double-sided adhesive sheet without a substrate with both sides of the adhesive layer protected by a release film is obtained.

[Example 4] 100 parts by weight and 300 parts by weight of polystyrene-poly(ethylene/propylene)-polystyrene block copolymer rubber (SEPS: "Septon 2063" manufactured by KURARAY, styrene content: 13%) as an adhesive composition parts of toluene were mixed to prepare an adhesive composition. After drying, the above-mentioned adhesive composition was applied to the peeling-treated surface of a PET separator (trade name "MRF50", manufactured by Mitsubishi Chemical Co., Ltd.) so that the thickness after drying was 20 μm, and the solvent was removed by heating at 130° C. for 5 minutes. And make the adhesive sheet. Moreover, a PET separator (trade name "MRF38", manufactured by Mitsubishi Chemical Co., Ltd.) was attached to the adhesive surface of the adhesive sheet so that the peeling-treated surface was in contact with the above-mentioned adhesive layer. A double-sided adhesive sheet without a substrate with both sides of the adhesive layer protected by a release film is obtained.

[Comparative Example 1] Except using 65 parts by weight of butyl acrylate (BA), 13 parts by weight of cyclohexyl acrylate (CHA), 7 parts by weight of 2-hydroxyethyl acrylate (HEA), and 30 parts by weight of 4-hydroxybutyl acrylate (4HBA) A double-sided adhesive sheet without a substrate was obtained in the same manner as in Example 1 except that the prepolymer composition was obtained from the monomer mixture.

[Examples 5 to 42] The mixture of the monomer components shown in Table 2 and 2,2' as a thermal polymerization initiator were put into a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirring device so that the monomer components were 70% by weight. -0.2 parts by weight of azobisisobutyronitrile (AIBN), and ethyl acetate as a polymerization solvent, nitrogen gas was introduced, and nitrogen replacement was performed for about 1 hour while stirring. Then, the reaction container was heated to 70 degreeC, and it was made to react for 6 hours. Furthermore, the reaction container was heated to 80 degreeC, and it was made to react for 3 hours, and the (meth)acrylic-type polymer of the weight average molecular weight (Mw) 400,000 was obtained. To this (meth)acrylic polymer solution (solid content 100 parts by weight) was added as an isocyanate-based crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Co., Ltd., solid content concentration 100% by weight) 0.1 part by weight based on solid content, 0.01 part by weight of dioctyltin dilaurate (trade name "Enbilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) as a crosslinking accelerator, and 0.01 part by weight as a crosslinking accelerator 5 parts by weight of acetone acetone as the retarder was mixed uniformly to prepare the adhesive composition of this example.

The above adhesive composition was coated on a polyethylene terephthalate (PET) release film (trade name "MRF38", Mitsubishi Chemical Co., Ltd. manufacturing) to form a coating layer (adhesive composition layer). Then, the drying process was performed for 120 minutes with a dryer at 130° C. to volatilize the solvent and residual monomers. Furthermore, a PET separator (trade name "MRE38", manufactured by Mitsubishi Chemical Co., Ltd.) was placed on the above-mentioned coating layer to obtain a substrate-free film composed of only an adhesive layer and both sides of the adhesive layer were protected by the separator. Double-sided adhesive sheet.

The unit of the numerical value shown in Table 2 is "weight part". In addition, each monomer component shown in Table 2 is as follows. LMA: lauryl methacrylate LA: lauryl acrylate 2-EHA: 2-ethylhexyl acrylate i-NA: isononyl acrylate L-7MA: C _12-13 alkyl methacrylate IDMA: methacrylic acid Isodecyl ester HEMA: 2-hydroxyethyl methacrylate MMA: methyl methacrylate MMA-macromonomer: methyl methacrylate macromonomer CHMA: cyclohexyl methacrylate IBXMA: iso-yl methacrylate Ester MAA: methacrylate NVP: N-vinylpyrrolidone PHE-1G: 2-phenoxyethyl methacrylate BzMA: benzyl methacrylate M-20G: 2-(2-methoxy methacrylate) ethoxy) ethyl ester

[Table 2] (Table 2) Monomer components LMA LA 2-EHA i-NA L-7MA IDMA HEMA MMA MMA - Giant Monomer CHMA IBXMA DCPMA MAA NVP PHE-1G BzMA M-20G Example 5 - - - - 99 - 1 - - - - - - - - - - Example 6 99 - - - - - 1 - - - - - - - - - - Example 7 - - - - - 99 1 - - - - - - - - - - Example 8 86 - - - - - 1 13 - - - - - - - - - Example 9 86 - - - - - 1 - 13 - - - - - - - - Example 10 98.9 - - - - - 0.1 - - - - - 1 - - - - Example 11 96.9 - - - - - 0.1 - - - - - 3 - - - - Example 12 94.9 - - - - - 0.1 - - - - - 5 - - - - Example 13 94.9 - - - - - 0.1 - - - - - - 5 - - - Example 14 86 - - - - - 1 - - 13 - - - - - - - Example 15 79 - - - - - 1 - - 20 - - - - - - - Example 16 66 - - - - - 1 - - 33 - - - - - - - Example 17 50 - - - - - 1 - - 49 - - - - - - - Example 18 86 - - - - - 1 - - - 13 - - - - - - Example 19 79 - - - - - 1 - - - 20 - - - - - - Example 20 66 - - - - - 1 - - - 33 - - - - - - Example 21 86 - - - - - 1 - - - - 13 - - - - - Example 22 79 - - - - - 1 - - - - 20 - - - - - Example 23 66 - - - - - 1 - - - - 33 - - - - - Example 24 86 - - - - - 1 - - - - - - - - 13 - Example 25 79 - - - - - 1 - - - - - - - - 20 - Example 26 86 - - - - - 1 - - - - - - - 13 - - Example 27 79 - - - - - 1 - - - - - - - 20 - - Example 28 86 - - - - - 1 - - - - - - - - - 13 Example 29 95 - - - - - 5 - - - - - - - - - - Example 30 90 - - - - - 10 - - - - - - - - - - Example 31 80 - - - - - 20 - - - - - - - - - - Example 32 84.5 - 14.5 - - - 1 - - - - - - - - - - Example 33 79.5 - 19.5 - - - 1 - - - - - - - - - - Example 34 74.5 - 24.5 - - - 1 - - - - - - - - - - Example 35 49.5 - 49.5 - - - 1 - - - - - - - - - - Example 36 24.5 - 74.5 - - - 1 - - - - - - - - - - Example 37 74.5 24.5 - - - - 1 - - - - - - - - - - Example 38 74.5 - - 24.5 - - 1 - - - - - - - - - - Example 39 36 - 50 - - - 1 - - 13 - - - - - - - Example 40 50 - - - - 39 1 - - 10 - - - - - - - Example 41 44.5 - - - - 44.5 1 - - 10 - - - - - - - Example 42 - - - - 89 1 - - 10 - - - - - - -

[Characteristic evaluation] The following measurements or evaluations were performed on the double-sided adhesive sheets without substrates of Examples and Comparative Examples. The evaluation results are shown in Table 3 and Table 4.

(1) Evaluation of dielectric constant and dielectric loss The adhesive layer alone (the one obtained by peeling off the polysiloxane-treated PET separator from the double-sided adhesive sheet) obtained in Examples or Comparative Examples was measured by the following apparatus at frequencies of 28 GHz and 60 Dielectric constant and dielectric loss at GHz. Measurements were performed on a circle with a diameter of 8 cm in the case of 28 GHz, and a circle with a diameter of 4 cm in the case of 60 GHz. Three samples were prepared from each specimen, and the average value of the measured values of the three samples was used as the relative permittivity and dielectric loss. Measurement method: Open resonator method JIS R1660-2 Device: Interferometric resonator method dielectric constant measurement system manufactured by KEYCOM Co., Ltd. Measurement environment: 23±1℃, 52±1%RH

(2) Total light transmittance and haze One of the separators was peeled off from the double-sided adhesive sheet, and the double-sided adhesive sheet was attached to a glass slide (manufactured by Songnami Glass Industrial Co., Ltd., "White Grinding No. 1", thickness 0.8-1.0 mm, full light transmittance of 92% and haze of 0.2%), and then peeled off the other separator to prepare a test piece having a layered structure of a double-sided adhesive sheet (adhesive layer)/glass slide. The total light transmittance and haze. Three samples were prepared from each specimen, and the average value of the measured values of the three samples was used as the total light transmittance and haze in the visible light region.

(3) Send and receive characteristics The transmission and reception characteristics of the adhesive layer obtained in the example or the comparative example (the one obtained by peeling off the polysiloxane-treated PET separator from the double-sided adhesive sheet) were obtained by using the square microstrip antenna shown in FIG. 4 . (Refer to Chapter 5, "Planar Antennas", 4 Group 2, Series 2, Institute of Electronic Communication and Information, URL: http://www.ieice hbkb.org/files/04/04gun_02hen_05.pdf) for evaluation. Specifically, a COP substrate (trade name: ZEONOR, manufactured by Nippon Zeon Co., Ltd.) having a thickness of 100 μm as the antenna substrate 44 was formed on the surface of the millimeter-wave patch antenna 43 , the shape shown in FIG. 4 , and the An antenna film 46 with a copper ground layer 45 having a thickness of 1 μm is formed on the backside. The dimensions of the millimeter-wave patch antenna 43 were adjusted so as to be optimal when laminated with the adhesives of the examples and comparative examples (vertical A: 2.8 to 3.2 mm, horizontal B: 4.13 mm). The adhesive layer 42 of each embodiment and the comparative example is attached to the side of the patch antenna 43 of the above-mentioned antenna film 46 to avoid the entry of air bubbles or foreign matter, and is then attached to a chemically strengthened glass (Corning company) with a thickness of 0.7 mm as the cover glass 41. manufacturing), and the antenna laminate 4 of the cover glass 41/adhesive layer 42/antenna film 46 was manufactured. The transmission and reception characteristics in the frequency band of 30 GHz were evaluated by supplying power from the microstrip line 43a of the millimeter-wave patch antenna 43 connected to the various antenna laminates 4, compared with the case where no adhesive layer was used (in The cover glass 41 is close to the gain (5.7 dB) of the antenna film 46, and the gain (5.7 dB) is set as 0, and the decrease (deterioration) is set as ×.

[table 3] (table 3) 28GHz 60GHz transparency Receive characteristics Dielectric constant Dielectric loss Dielectric constant Dielectric loss total light transmittance haze Example 1 2.41 0.022 2.33 0.011 92.3 0.24 〇 Example 2 2.67 0.049 2.61 0.020 92.5 0.26 〇 Example 3 2.84 0.002 2.38 0.001 92.1 0.30 〇 Example 4 2.36 0.001 2.22 0.001 91.9 0.32 〇 Comparative Example 1 2.90 0.175 2.75 0.058 92.3 0.24 × Example 5 2.27 0.004 2.39 0.001 93.0 0.20 〇 Example 6 2.32 0.005 2.33 0.003 93.0 0.30 〇 Example 7 2.41 0.006 2.44 0.004 92.8 0.40 〇 Example 8 2.47 0.004 2.12 0.003 92.8 0.60 〇 Example 9 2.30 0.006 2.47 0.004 92.6 1.20 〇 Example 10 2.24 0.003 2.44 0.002 92.9 0.20 〇 Example 11 2.69 0.004 2.66 0.004 92.7 0.60 〇 Example 12 2.26 0.003 2.66 0.002 92.8 0.80 〇 Example 13 2.31 0.005 2.23 0.003 92.8 0.30 〇 Example 14 2.18 0.005 2.13 0.003 92.4 0.40 〇 Example 15 2.26 0.004 2.44 0.003 92.8 0.50 〇 Example 16 2.46 0.004 2.49 0.002 92.6 0.70 〇 Example 17 2.34 0.004 2.48 0.003 92.5 0.88 〇 Example 18 2.55 0.004 2.35 0.002 92.8 0.30 〇 Example 19 2.38 0.003 2.34 0.003 92.7 0.50 〇 Example 20 2.35 0.003 2.89 0.002 92.7 0.20 〇

[Table 4] (Table 4) 28GHz 60GHz transparency Receive characteristics Dielectric constant Dielectric loss Dielectric constant Dielectric loss total light transmittance haze Example 21 2.32 0.003 2.19 0.004 92.8 0.40 〇 Example 22 2.56 0.004 2.24 0.002 92.7 0.50 〇 Example 23 2.63 0.003 2.49 0.003 92.6 0.80 〇 Example 24 2.33 0.004 2.28 0.003 92.7 0.30 〇 Example 25 2.30 0.005 2.32 0.004 92.6 0.40 〇 Example 26 2.52 0.005 2.37 0.004 92.7 0.30 〇 Example 27 2.59 0.007 3.29 0.003 92.7 0.40 〇 Example 28 2.54 0.029 2.19 0.016 92.8 0.30 〇 Example 29 2.26 0.008 2.22 0.003 92.8 0.50 〇 Example 30 2.26 0.013 2.26 0.009 92.8 0.70 〇 Example 31 2.30 0.019 2.64 0.008 92.7 0.10 〇 Example 32 2.31 0.006 2.28 0.004 92.8 0.20 〇 Example 33 2.49 0.007 2.47 0.006 92.8 0.10 〇 Example 34 2.46 0.007 2.39 0.004 92.9 0.40 〇 Example 35 2.25 0.012 2.19 0.008 93.0 0.60 〇 Example 36 2.38 0.019 2.44 0.011 92.9 0.10 〇 Example 37 2.29 0.006 2.18 0.004 92.9 0.10 〇 Example 38 2.45 0.007 2.21 0.004 92.9 0.20 〇 Example 39 2.50 0.012 2.47 0.008 92.8 0.20 〇 Example 40 2.69 0.004 2.58 0.002 92.7 0.40 〇 Example 41 2.61 0.004 2.51 0.004 92.7 0.40 〇 Example 42 2.50 0.005 2.44 0.005 92.7 0.50 〇

Variations of the present invention are noted below. [Note 1] An adhesive composition having a dielectric constant of 2 to 5 at a frequency of 28 GHz, The dielectric loss at a frequency of 28 GHz is 0.0001 to 0.05. [Note 2] The adhesive composition as described in Note 1, whose dielectric constant at a frequency of 60 GHz is 2 to 5, The dielectric loss at a frequency of 60 GHz is 0.0001 to 0.05. [Note 3] An adhesive composition having a dielectric constant of 2 to 5 at a frequency of 60 GHz, The dielectric loss at a frequency of 60 GHz is 0.0001 to 0.05. [Note 4] An adhesive layer formed from the adhesive composition according to any one of Notes 1 to 3. [Note 5] An adhesive sheet having the adhesive layer as described in Note 4. [Note 6] A millimeter-wave antenna comprising at least the adhesive sheet and a substrate as described in Note 5, and the substrate has an antenna element on at least one side, and the substrate has the antenna element on the side on the side The above-mentioned adhesive sheet is attached.

1A: mmWave antenna 1B: mmWave antenna 1C: mmWave antenna 2: mmWave antenna elements 4: Antenna laminated body 10: Adhesive sheet 10a: Adhesive sheet 10b: Adhesive sheet 11: mmWave antenna substrate 12: Cover member 13: Image display panel 41: Cover glass 42: Adhesive layer 43: Patch Antennas for Millimeter Waves 43a: Microstrip line 44: Antenna substrate 45: Copper ground plane 46: Antenna film

FIG. 1 is a schematic view (sectional view) showing an embodiment of the millimeter wave antenna of the present invention. FIG. 2 is a schematic view (sectional view) showing an embodiment of the millimeter wave antenna of the present invention. FIG. 3 is a schematic diagram (cross-sectional view) showing an embodiment of the millimeter-wave antenna of the present invention. FIG. 4 is a schematic view (sectional view) showing an antenna laminate used for evaluation of transmission and reception characteristics. Fig. 4(a) is a side sectional view, and Fig. 4(b) is a top projection view.

Claims (6)

An adhesive composition having a dielectric constant of 2 to 5 at a frequency of 28 GHz, The dielectric loss at a frequency of 28 GHz is 0.0001 to 0.05. As claimed in the adhesive composition of claim 1, its dielectric constant at a frequency of 60 GHz is 2 to 5, The dielectric loss at a frequency of 60 GHz is 0.0001 to 0.05. An adhesive composition having a dielectric constant of 2 to 5 at a frequency of 60 GHz, The dielectric loss at a frequency of 60 GHz is 0.0001 to 0.05. An adhesive layer formed by the adhesive composition according to any one of claims 1 to 3. An adhesive sheet having the adhesive layer as claimed in claim 4. A millimeter-wave antenna, which at least has the adhesive sheet and substrate as claimed in claim 5, and the substrate is provided with an antenna element on at least one side, and the adhesive is attached to the side of the substrate with the antenna element. Sheet.

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