JP2019119767A - Adhesive and adhesive tape - Google Patents

Abstract

To provide an adhesive that achieves both alcohol resistance and impact resistance, and an adhesive tape having the adhesive as an adhesive layer.SOLUTION: An adhesive contains a (meth) acrylate copolymer with a content of a constitutional unit derived from fluorine-containing (meth) acrylate being 30 to 70 wt%, and a compound represented by general formula (1) with a boiling point of 160°C or more. In the general formula (1), m is an integer of 1 or greater; n is an integer of 1 or more and 10 or less; and Rand Reach represent a hydrocarbon group having 1 or more and 10 or less carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a pressure sensitive adhesive and a pressure sensitive adhesive tape.

  2. Description of the Related Art Conventionally, adhesive tapes have been widely used in fixing components in electronic devices. Specifically, for example, an adhesive tape is used to bond a cover panel for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to bond a touch panel module and a display panel module. ing. The pressure-sensitive adhesive tape used for fixing such electronic device parts has, for example, a pressure-sensitive adhesive layer containing an acrylic pressure-sensitive adhesive, etc., and in addition to high tackiness, heat resistance according to the environment of the part used. Functions such as thermal conductivity and impact resistance are required (for example, Patent Documents 1 to 3).

Unexamined-Japanese-Patent No. 2015-052050 JP, 2015-021067, A JP, 2015-120876, A

  Especially in recent years, portable electronic devices have become widespread. These portable electronic devices are expected to be impacted by falling or to touch alcoholic beverages and the like. For this reason, the adhesive tape for fixing parts is desired to have impact resistance and performance (alcohol resistance) in which adhesion is not deteriorated by alcohol.

  In order to improve the alcohol resistance, it is conceivable to improve the strength of the pressure-sensitive adhesive layer when an alcoholic beverage or the like adheres to the pressure-sensitive adhesive tape. On the other hand, in order to improve impact resistance, it is conceivable to improve the flexibility of the pressure-sensitive adhesive layer. The inventors thus found that alcohol resistance and impact resistance have a trade-off relationship.

  In view of the above-mentioned subject, an object of the present invention is to provide an adhesive which makes alcohol tolerance and impact resistance compatible. Another object of the present invention is to provide a pressure-sensitive adhesive tape having the above-mentioned pressure-sensitive adhesive as a pressure-sensitive adhesive layer.

MEANS TO SOLVE THE PROBLEM As a result of examining as a result of solving the said subject, the present inventors are alcohol by containing the (meth) acrylate copolymer and the specific compound which have a structural unit originating in fluorine-containing (meth) acrylate. It has been found that a pressure-sensitive adhesive having both resistance and impact resistance can be obtained, and the present invention has been completed.
In addition, "alcohol" in the present specification means one having a lower alcohol having 4 or less carbon atoms as a single component, or a mixture thereof. As long as a lower alcohol having 4 or less carbon atoms or a mixture thereof is used as the main component (content is 50% by weight or more), water, other solvents such as alcohol having a higher carbon number, additives, etc. may be included.

  That is, according to the first aspect of the present invention, there is provided a (meth) acrylate copolymer having a content of 30 to 70% by weight of a constituent unit derived from fluorine-containing (meth) acrylate, and the following general formula (boiling point is 160 ° C. or more) It is an adhesive containing the compound represented by 1).

In general formula (1), m represents an integer of 1 or more, n represents an integer of 1 to 10, and R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms.

  In the second invention, a (meth) acrylate copolymer having a content of 30 to 70% by weight of a constituent unit derived from fluorine-containing (meth) acrylate, and a dicarboxylic acid ester or diol having a boiling point of 160 ° C. or higher It is an adhesive containing an ester.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive which makes alcohol resistance and impact resistance compatible can be provided. Further, according to the present invention, it is possible to provide a pressure-sensitive adhesive tape having the above-mentioned pressure-sensitive adhesive as a pressure-sensitive adhesive layer.

It is a schematic diagram explaining the drop impact test of a double-sided adhesive tape.

  The adhesive concerning the 1st and 2nd this invention contains the (meth) acrylate copolymer whose content of the structural unit originating in fluorine-containing (meth) acrylate is 30 to 70 weight%. By containing the (meth) acrylate copolymer, the pressure-sensitive adhesive according to the first and second aspects of the present invention maintains the adhesion of the pressure-sensitive adhesive even when an alcoholic beverage or the like adheres to the pressure-sensitive adhesive. be able to.

The fluorine-containing (meth) acrylate is not particularly limited. For example, 2,2,2-trifluoroethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- ( Perfluorobutyl) ethyl (meth) acrylate, 3-perfluorobutyl-2-hydroxypropyl (meth) acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth) acrylate, 3- (perfluoro-3-methylbutyl) -2-hydroxypropyl (meth) acrylate, 1H, 1H, 3H-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 7H-dodecafluoroheptyl (meth) Acrylate, 1H-1- (trifluoro) (Tyl) trifluoroethyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl (meth) acrylate, 1,2,2,2-tetrafluoro-1- (trifluoromethyl) ethyl (meth) acrylate etc Be
Among them, 2- (perfluorohexyl) ethyl acrylate (13F) and 2,2,2-trifluoroethyl acrylate (3F) are preferable because of their high alcohol resistance. These fluorine-containing (meth) acrylates may be used alone or in combination of two or more.
In the present specification, “(meth) acrylate” means acrylate or methacrylate. From the viewpoint of lowering the glass transition temperature of the (meth) acrylate copolymer and adjusting the adhesive strength, acrylate is preferred.

  The content of the constituent unit derived from the fluorine-containing (meth) acrylate is 30% by weight or more and 70% by mass or less in 100% by weight of all the constituent units of the (meth) acrylate copolymer. When the content is 30% by weight or more, the penetration of alcohol into the molecular chain of the (meth) acrylate copolymer is suppressed by the high water and oil repellency of fluorine itself and the dense packing of fluorine atoms. Be For this reason, it is thought that the swelling rate with respect to the alcohol of the said (meth) acrylate copolymer becomes low, and the alcohol tolerance of an adhesive improves. When the content is 70% by weight or less, the pressure-sensitive adhesive does not become too hard, and sufficient tackiness can be maintained, and sufficient initial adhesion can be exhibited. It is also excellent in impact resistance. The lower limit of the content is preferably 40% by weight, the upper limit is preferably 60% by weight, and the lower limit is more preferably 50% by weight.

  The (meth) acrylate copolymer preferably further has a structural unit derived from an alkyl (meth) acrylate having an alkyl group having 6 or more carbon atoms. The adhesive obtained is excellent in alcohol tolerance because the (meth) acrylate copolymer contains the structural unit derived from the alkyl (meth) acrylate which has the said C6 or more alkyl group.

  The alkyl (meth) acrylate having an alkyl group having 6 or more carbon atoms is not particularly limited. For example, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, isostearyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, decyl (meth) ) Acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate and the like. Among them, 2-ethylhexyl (meth) acrylate or octyl (meth) acrylate is preferable because it can exhibit suitable adhesive strength. These alkyl (meth) acrylates having an alkyl group having 6 or more carbon atoms may be used alone or in combination of two or more.

  The content of the structural unit derived from the alkyl (meth) acrylate having an alkyl group having a carbon number of 6 or more is preferably 20% by weight with a preferable lower limit in 100% by weight of the total structural units of the (meth) acrylate copolymer. The preferred upper limit is 50% by weight. When the content is 20% by weight or more, the pressure-sensitive adhesive does not become too hard and can be deformed when a peeling force is applied, so that sufficient adhesive force can be exhibited. When the content is 50% by weight or less, the pressure-sensitive adhesive does not become too soft, and sufficient cohesion can be maintained, and sufficient cohesion can be exhibited. A more preferable upper limit of the content is 45% by weight.

  The (meth) acrylate copolymer preferably further contains a structural unit derived from an alkyl (meth) acrylate having an alkyl group having 2 or less carbon atoms. When the (meth) acrylate copolymer contains a constituent unit derived from an alkyl (meth) acrylate having an alkyl group having a carbon number of 2 or less, entanglement between polymers is increased, and adhesion of the pressure-sensitive adhesive Improves cohesion and cohesion. As a result, the pressure-sensitive adhesive becomes difficult to peel off, and the alcohol resistance is improved. Furthermore, the resistance of the pressure-sensitive adhesive to oleic acid is also enhanced by the (meth) acrylate copolymer containing a structural unit derived from an alkyl (meth) acrylate having an alkyl group having 2 or less carbon atoms. You can also. Thus, the pressure-sensitive adhesive can have both alcohol resistance and resistance to sebum containing oleic acid as a main component. As a result, even when sebum or the like adheres to the adhesive, the adhesive strength of the adhesive can be maintained.

  The alkyl (meth) acrylate having an alkyl group having 2 or less carbon atoms is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate and the like can be mentioned. Among them, ethyl acrylate is preferred because the obtained adhesive does not become too hard, can maintain sufficient tackiness, can exhibit sufficient initial adhesion, and is excellent in resistance to oleic acid. And methyl acrylate are preferred.

  The content of the structural unit derived from the alkyl (meth) acrylate having an alkyl group having a carbon number of 2 or less is preferably 10% by weight, with respect to 100% by weight of all the structural units of the (meth) acrylate copolymer. The preferred upper limit is 40% by weight. When the content is in the above range, the polarity of the (meth) acrylate copolymer can be prevented from becoming too high. This suppresses the infiltration of oleic acid into the resulting adhesive and improves the resistance to oleic acid. The more preferable lower limit of the content is 15% by weight, and the more preferable upper limit is 30% by weight.

  The (meth) acrylate copolymer preferably further contains a structural unit derived from a monomer having a polar functional group. By incorporating a structural unit derived from a monomer having a polar functional group into the (meth) acrylate copolymer, the cohesion of the obtained pressure-sensitive adhesive can be enhanced, and the adhesion can be enhanced.

The polar functional group has reactivity such as crosslinking reaction, and is preferably at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and an epoxy group. Among these, a hydroxyl group or a carboxyl group is more preferable because it can contribute to the improvement of the adhesive strength.
As a monomer which has the said hydroxyl group, the (meth) acrylate which has hydroxyl groups, such as 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate, is mentioned, for example.
As a monomer which has the said carboxyl group, (meth) acrylic acid is mentioned, for example.
As a monomer which has the said epoxy group, glycidyl (meth) acrylate is mentioned, for example.
These monomers having a polar functional group may be used alone or in combination of two or more.

  The content of the structural unit derived from the polar functional group-containing monomer is not particularly limited, but the preferable lower limit is 0.1% by weight and the preferable upper limit is 100% by weight of the total structural units of the (meth) acrylate copolymer. It is 5% by weight. When the content is in the above range, the cohesive strength of the obtained pressure-sensitive adhesive can be further enhanced. Moreover, it becomes easy to adjust the gel fraction and swelling rate of the adhesive layer formed from an adhesive.

  The (meth) acrylate copolymer may further contain a structural unit derived from another monomer, as long as the effects of the present invention are not impaired. As such a monomer, for example, propyl acrylate, butyl acrylate, benzyl acrylate, phenoxyethyl acrylate, vinyl acetate, acrylonitrile and the like can be mentioned.

The lower limit of the weight average molecular weight of the (meth) acrylate copolymer is preferably 300,000, and the upper limit is preferably 1.5 million. When the weight average molecular weight of the (meth) acrylate copolymer is 300,000 or more, the cohesion of the obtained adhesive is improved, and the alcohol resistance is improved. If the weight average molecular weight of the (meth) acrylate copolymer is not more than 1,500,000, the adhesive strength at the interface between the obtained adhesive and the adherend will be high, and the alcohol resistance of the adhesive will be improved. A more preferable lower limit of the above weight average molecular weight is 400,000, and a more preferable upper limit is 1.2 million, a further more preferable lower limit is 500,000, and a still more preferable upper limit is 1.1 million.
In addition, a weight average molecular weight can be adjusted with superposition | polymerization conditions (For example, the kind or quantity of a polymerization initiator, superposition | polymerization temperature, monomer concentration etc.).

  In the present specification, the weight average molecular weight (Mw) means a value measured as a polystyrene equivalent molecular weight by gel permeation chromatography (GPC) method. Specifically, the measurement sample is diluted 50 times with tetrahydrofuran (THF), and the sample filtered with a filter is used to measure as a polystyrene equivalent molecular weight by the GPC method. As a column used for GPC method, 2690 Separations Model (made by Waters) etc. can be used, for example.

  In order to synthesize the above (meth) acrylate copolymer, the monomer from which the above constituent unit is derived may be polymerized in the presence of a polymerization initiator. The polymerization method is not particularly limited, and conventionally known methods can be used. For example, solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization and the like can be mentioned. Among them, solution polymerization is preferable because the synthesis is simple. Further, particularly when the content of the structural unit derived from acrylonitrile is increased, emulsion polymerization is preferred.

  When solution polymerization is used as the polymerization method, examples of the reaction solvent include ethyl acetate, toluene, methyl ethyl ketone, methyl sulfoxide, ethanol, acetone, diethyl ether and the like. These reaction solvents may be used alone or in combination of two or more.

It does not restrict | limit especially as said polymerization initiator, A radical polymerization initiator, an anionic polymerization initiator, a cationic polymerization initiator etc. can be used. Among them, a radical polymerization initiator can be suitably used.
As said radical polymerization initiator, an organic peroxide, an azo compound, etc. are mentioned, for example. Examples of the organic peroxide include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, and 2,5. -Dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Isobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy laurate and the like can be mentioned. Examples of the azo compound include azobisisobutyronitrile, azobiscyclohexanecarbonitrile and the like.
These polymerization initiators may be used alone or in combination of two or more.

  The pressure-sensitive adhesive according to the first aspect of the present invention contains a compound represented by the following general formula (1) having a boiling point of 160 ° C. or more. By containing the compound represented by following General formula (1), the impact resistance of the adhesive obtained can be improved. In addition, the alcohol resistance of the obtained adhesive is also improved. By containing the compound represented by following General formula (1), since the softness | flexibility of the obtained adhesive improves, it is thought that impact resistance improves.

In general formula (1), m represents an integer of 1 or more, n represents an integer of 1 to 10, and R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms.

  The boiling point of the compound represented by the above general formula (1) is 160 ° C. or more. By using a compound having a boiling point of 160 ° C. or more, the compound represented by the above general formula (1) is less likely to volatilize, even after passing through a pressure-sensitive adhesive tape production step (particularly, a step of drying the pressure-sensitive adhesive solution). Thereby, the compound represented by the said General formula (1) can be stably contained in an adhesive layer. The preferable lower limit of the boiling point of the compound represented by the above general formula (1) is 180 ° C., and the more preferable lower limit is 200 ° C.

In the repeating unit (C _m H _{2 m 2} O) of the compound represented by the above general formula (1), m is an integer of 1 or more. m can be optionally set such that the boiling point of the compound represented by the above general formula (1) is 160 ° C. or higher.

  In the compound represented by the above general formula (1), the number n of repeating units is an integer of 1 or more and 10 or less. When the number n of repeating units is an integer of 10 or less, the compatibility of the compound represented by the general formula (1) with the (meth) acrylate copolymer is improved. Moreover, the affinity with respect to water or alcohol of the compound represented by the said General formula (1) can be suppressed, and the alcohol tolerance of an adhesive improves. The preferable upper limit of the number n of repeating units is six.

In the compound represented by the general formula (1), the substituents R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group may be linear or branched.
By having a hydrocarbon group having a carbon number within the above range, the compatibility of the compound represented by the above general formula (1) with the above (meth) acrylate copolymer is improved.

  As the compound represented by the above general formula (1), for example, diethylene glycol dimethyl ether (diglyme), diethylene glycol diethyl ether, triethylene glycol dimethyl ether (triglyme) and tetraethylene glycol dimethyl ether (tetraglyme) can be suitably used.

The content of the compound represented by the general formula (1) is preferably 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the (meth) acrylate copolymer. The impact resistance of the obtained adhesive improves more because the said content is 5 weight part or more.
From the viewpoint of compatibility with the (meth) acrylate copolymer, the content is preferably 30 parts by weight or less. The more preferable lower limit of the content is 10 parts by weight, and the more preferable upper limit is 20 parts by weight.

  The adhesive according to the second invention contains a dicarboxylic acid ester or diol ester having a boiling point of 160 ° C. or higher. The impact resistance of the obtained adhesive can be improved by containing the said dicarboxylic acid ester or diol ester. In addition, the alcohol resistance of the obtained adhesive is further improved. By containing the above-mentioned dicarboxylic acid ester or diol ester, it is considered that the impact resistance is improved since the flexibility of the obtained pressure-sensitive adhesive is improved.

  The boiling point of the dicarboxylic acid ester or diol ester is 160 ° C. or more. By using a dicarboxylic acid ester or diol ester having a boiling point of 160 ° C. or more, the dicarboxylic acid ester or diol ester is less likely to volatilize even after passing through a pressure-sensitive adhesive tape production process (in particular, a drying process of the pressure-sensitive adhesive solution). Thereby, the said dicarboxylic acid ester or diol ester can be stably contained in an adhesive layer. The preferable lower limit of the boiling point is 180 ° C., and the more preferable lower limit is 200 ° C.

  It is preferable that the said dicarboxylic acid ester is a compound represented by following General formula (2-1) or (2-2).

R ¹ , R ² and R ^{3 in the} general formula (2-1) each represent a hydrocarbon group having 1 to 10 carbon atoms.

R ¹ and R ² in the general formula (2-2) each represent a hydrocarbon group having 1 to 10 carbon atoms, Ar represents an aromatic hydrocarbon group, and the bonding position of the aromatic hydrocarbon group is particularly preferably It is not restricted.

The diol ester is preferably a compound represented by the following general formula (2-3), (2-4) or (2-5). Especially, it is more preferable that it is a compound represented by following General formula (2-3) from a compatible viewpoint with respect to the said (meth) acrylate copolymer.

In General Formula (2-3), m represents an integer of 1 or more, n represents an integer of 1 to 10, and R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms.

R ¹ , R ² and R ^{3 in the} general formula (2-4) each represent a hydrocarbon group having 1 to 10 carbon atoms.

一般式（２−５）中Ｒ^１、Ｒ^２はそれぞれ炭素数が１以上１０以下の炭化水素基を表し、Ａｒは芳香族炭化水素基を表し、該芳香族炭化水素基の結合位置は特に制限されない。

In the general formula (2-5), R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms, Ar represents an aromatic hydrocarbon group, and the bonding position of the aromatic hydrocarbon group is particularly preferably It is not restricted.

The substituents R ¹ and R ² in the compounds represented by the general formulas (2-1) to (2-5) each represent a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group may be linear or branched.
By having a hydrocarbon group having a carbon number within the above range, the compatibility of the compounds represented by the general formulas (2-1) to (2-5) with the (meth) acrylate copolymer is improved.

The substituent R ³ in the compound represented by the above general formula (2-1) or (2-4) represents a hydrocarbon group having 1 to 10 carbon atoms (e.g., an alkenyl group or the like). The hydrocarbon group may be linear or branched.
By having a hydrocarbon group having a carbon number within the above range, the compatibility of the compound represented by the above general formula (2-1) or (2-4) with the above (meth) acrylate copolymer is improved.

The substituent Ar in the compound represented by the above general formula (2-2) or (2-5) represents an aromatic hydrocarbon group, and the bonding position of the aromatic hydrocarbon group is not particularly limited.
As such an aromatic hydrocarbon group, benzene, naphthalene, anthracene, phenanthrene etc. can be mentioned.

In the repeating unit of the compound represented by the general formula _{(2-3) (C m H 2m} O), m is an integer of 1 or more. m can be optionally set such that the boiling point of the compound represented by the above general formula (2-3) is 160 ° C. or higher.

  In the compounds represented by the above general formula (2-3), the number n of repeating units is an integer of 1 or more and 10 or less. When the number n of repeating units is 10 or less, the compatibility of the compound represented by the general formula (2-3) with the (meth) acrylate copolymer is improved. Moreover, the affinity with respect to water or alcohol of the compound represented by the said General formula (2-3) can be suppressed, and the alcohol tolerance of an adhesive improves. The preferable upper limit of the number n of repeating units is six.

As a compound represented by the said General formula (2-1), the dioctyl adipate is mentioned, for example. Examples of the compound represented by the above general formula (2-2) include dioctyl phthalate and diethyl phthalate.
Examples of the compound represented by the above general formula (2-3) include triethylene glycol di (2-ethylhexanoate). As a compound represented by the said General formula (2-4), a butanediol diacrylate is mentioned, for example. As a compound represented by the said General formula (2-5), benzenediol dioctyl and benzenediol diethyl are mentioned, for example.

The content of the dicarboxylic acid ester or diol ester is preferably 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the (meth) acrylate copolymer. The impact resistance of the obtained adhesive improves more because the said content is 5 weight part or more.
From the viewpoint of compatibility with the (meth) acrylate copolymer, the content is preferably 30 parts by weight or less. The more preferable lower limit of the content is 10 parts by weight, and the more preferable upper limit is 20 parts by weight.

  The pressure-sensitive adhesive according to the first and second aspects of the present invention preferably contains a crosslinking agent. By containing the said crosslinking agent, the polar functional group of the structural unit derived from the monomer which has the said polar functional group can be bridge | crosslinked, and a crosslinked structure can be comprised. This makes it easy to adjust the gel fraction and the swelling ratio of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive.

The said crosslinking agent is not specifically limited, For example, an isocyanate type crosslinking agent, an aziridine type crosslinking agent, an epoxy type crosslinking agent, a metal chelate type crosslinking agent etc. are mentioned. Among these, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferable because the bond formed after the crosslinking reaction is polarized, and the adhesive layer easily interacts with various adherends and the interfacial adhesion becomes strong. And isocyanate type crosslinking agents are more preferable.
The content of the crosslinking agent is not particularly limited, but the preferable lower limit is 0.001 parts by weight, the preferable upper limit is 20 parts by weight, and the more preferable lower limit is 0.005 parts by weight with respect to 100 parts by weight of the (meth) acrylate copolymer. The upper limit is preferably 10 parts by weight, more preferably 0.01 parts by weight, and still more preferably 5 parts by weight.

  The pressure-sensitive adhesive according to the first and second aspects of the present invention preferably contains a silane coupling agent. By containing a silane coupling agent, the adhesive strength at the interface between the pressure-sensitive adhesive and the adherend can be enhanced.

  The said silane coupling agent is not specifically limited. For example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane Silane, 3-aminopropyltrimethylmethoxysilane, N- (2-aminoethyl) 3-aminopropyltriethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-mercapto B pills trimethoxysilane, 3-mercaptopropyl triethoxy silane, mercaptopropyl butyl trimethoxy silane, 3-mercaptopropyl methyl dimethoxy silane, and the like. Among them, 3-glycidoxypropyltrimethoxysilane is preferable.

  The preferable lower limit of the content of the silane coupling agent is 0.1 parts by weight and the preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the (meth) acrylate copolymer. When the content is 0.1 parts by weight or more, the adhesive strength at the interface between the obtained pressure-sensitive adhesive and the adherend becomes high, and the alcohol resistance of the obtained pressure-sensitive adhesive is improved. When the content is 5 parts by weight or less, the adhesive residue when the pressure-sensitive adhesive is peeled can be suppressed, and the reworkability when formed into a pressure-sensitive adhesive tape is improved. A more preferable lower limit of the content is 0.5 parts by weight, a more preferable upper limit is 4 parts by weight, a more preferable lower limit is 1 part by weight, and a still more preferable upper limit is 3 parts by weight.

  The pressure-sensitive adhesive according to the first and second aspects of the present invention is, if necessary, an emulsifier, a softener, a filler, a pigment, an additive such as a dye, a tackifier such as a rosin resin or a terpene resin, and the like. You may contain resin etc.

The gel fraction of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive according to the first and second inventions is preferably 5% by weight or more and 70% by weight or less. When the gel fraction is 5% by weight or more, the cohesion of the pressure-sensitive adhesive layer is improved, and the alcohol resistance is improved. If the gel fraction is 70% by weight or less, the adhesive strength at the interface between the pressure-sensitive adhesive layer and the adherend is high, and the alcohol resistance of the pressure-sensitive adhesive layer is improved. In addition, since the pressure-sensitive adhesive layer does not become too hard and can be deformed when the peeling force is applied, sufficient initial adhesive strength can be exhibited. The lower limit of the gel fraction is more preferably 10% by weight, more preferably 55% by weight, still more preferably 25% by weight, still more preferably 40% by weight, particularly preferably 30% by weight. . The gel fraction can be adjusted, for example, by changing the content of the crosslinking agent, the introduction amount of a monomer having a functional group having reactivity such as crosslinking reaction in the (meth) acrylate copolymer, and the like.
In addition, with "gel fraction" in this specification, it immerses in ethyl acetate with respect to the weight of the adhesive tape which has an adhesive layer containing the adhesive before immersing in ethyl acetate like following formula (1) It is the value which represented the ratio of the weight of the adhesive tape which has an adhesive layer containing the adhesive after drying with a percentage.
Gel fraction (% by weight) = 100 × (W ₂ −W ₀ ) / (W ₁ −W ₀ ) (1)
(W ₀ : Weight of substrate, W ₁ : Weight of adhesive tape having adhesive layer containing an adhesive before immersion in ethyl acetate, W ₂ : Adhesive layer containing an adhesive after immersion in ethyl acetate, and drying With adhesive tape weight)

The pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive according to the first and second inventions is immersed in a mixed solution of 75% by weight of ethanol and 25% by weight of water for 24 hours under the conditions of 60.degree. C. and 90% humidity. The swelling ratio is preferably 100% by weight or more and 150% by weight or less. If the said swelling ratio is 100 weight% or more, it means that there is no elution of the adhesive component to the said liquid mixture, and the alcohol tolerance of an adhesive improves. If the said swelling rate is 150 weight% or less, the alcohol tolerance of an adhesive will improve. The upper limit of the swelling ratio is more preferably 140% by weight, and still more preferably 130% by weight.
In addition, "swelling rate" in the present specification is a value represented by the following formula (2). That is, “swelling ratio” means 75% by weight of ethanol and 25% by weight of a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive before being immersed in a mixture of 75% by weight of ethanol and 25% by weight of water. It is the value which represented the ratio of the weight of the adhesive tape which has an adhesive layer containing the adhesive after immersing in the liquid mixture with weight% and drying it as a percentage. When there is elution of the pressure-sensitive adhesive component into the mixture, the swelling ratio is less than 100% by weight.
Swelling ratio (% by weight) = 100 × (W ₅ −W ₃ ) / (W ₄ −W ₃ ) (2)
(W _3: the weight of the base material, W _4: weight of the pressure-sensitive tape having an adhesive layer containing a pressure-sensitive adhesive prior to mixing liquid immersion of ethanol 75% and 25% by weight of water, W _5: Ethanol 75 wt% Of mixed solution of water and 25% by weight of water, weight of adhesive tape having adhesive layer containing adhesive after drying

A pressure-sensitive adhesive tape having the pressure-sensitive adhesive according to the first or second invention as a pressure-sensitive adhesive layer on at least one side is also one of the present invention.
The thickness of the pressure-sensitive adhesive layer is not particularly limited, but a preferable lower limit is 5 μm and a preferable upper limit is 100 μm. When the thickness of the pressure-sensitive adhesive layer is 5 μm or more, the adhesion of the pressure-sensitive adhesive tape is improved. When the thickness of the pressure-sensitive adhesive layer is 100 μm or less, the processability of the pressure-sensitive adhesive tape is improved.

  The pressure-sensitive adhesive tape according to the present invention may be a support type having a substrate, as long as the pressure-sensitive adhesive layer is provided on at least one surface, or may be a non-support type having no substrate. . In the case of the support type, the pressure-sensitive adhesive layer may be formed on one side of the substrate, or the pressure-sensitive adhesive layer may be formed on both sides.

The said base material is not specifically limited, For example, polyester-based resin films, such as polyolefin resin films, such as a polyethylene film and a polypropylene film, and a PET film, are mentioned. Moreover, polyolefin foam sheets, such as an ethylene-vinyl acetate copolymer film, a polyvinyl chloride-type resin film, a polyurethane-type resin film, a polyethylene foam sheet, a polypropylene foam sheet, a polyurethane foam sheet etc. are mentioned. Among them, PET film is preferable. Also, from the viewpoint of impact resistance, a polyolefin foam sheet is preferred.
In addition, as the above-mentioned substrate, a substrate printed black for preventing light transmission, a substrate printed white for improving light reflectivity, a substrate vapor-deposited with metal, etc. can be used.

  The thickness of the substrate is not particularly limited, but the preferable lower limit is 50 μm, and the preferable upper limit is 400 μm. When the thickness of the substrate is 50 μm or more, the impact resistance of the pressure-sensitive adhesive tape is improved. If the thickness of the said base material is 400 micrometers or less, it will become an adhesive tape suitable for the use which fixes the components of an electronic device.

The manufacturing method of the adhesive tape which concerns on this invention is not specifically limited, For example, when the adhesive tape which concerns on this invention is a double-sided adhesive tape which has a base material, the following methods are mentioned.
First, a solvent is added to the (meth) acrylate copolymer, the compound or dicarboxylic acid ester or diol ester represented by the above general formula (1), and, if necessary, additives, etc. to prepare a solution of the adhesive a. Do. The solution of the pressure-sensitive adhesive a is applied to the surface of the substrate, and the solvent in the solution is completely removed by drying to form a pressure-sensitive adhesive layer a. Next, a release film is superimposed on the formed pressure-sensitive adhesive layer a with the release-treated surface of the release film facing the pressure-sensitive adhesive layer a.
Then, a release film different from the above release film is prepared, a solution of the adhesive b is applied to the release treated surface of the release film, and the solvent in the solution is completely removed by drying. The laminated film in which the adhesive layer b was formed in the surface of a type | mold film is produced. The resulting laminated film is superimposed on the back surface of the substrate on which the pressure-sensitive adhesive layer a is formed, in a state where the pressure-sensitive adhesive layer b faces the back surface of the substrate, to prepare a laminate. Then, by pressing the above laminate with a rubber roller or the like, it is possible to obtain a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on both sides of the substrate and having the surface of the pressure-sensitive adhesive layer covered with a release film.

  As another manufacturing method, two sets of laminated films are produced in the same manner, and these laminated films are superposed on each of both sides of the substrate in a state where the pressure-sensitive adhesive layer of the laminated film is opposed to the substrate A laminate can be produced, and this laminate can be pressed by a rubber roller or the like. By this, it has an adhesive layer on both sides of a substrate, and the surface of an adhesive layer may obtain the adhesive tape covered with the mold release film.

  The use of the adhesive tape according to the present invention is not particularly limited, but because it is excellent in alcohol resistance and impact resistance, it has many opportunities to touch alcoholic beverages and the like, and it fixes parts of electronic devices used routinely. Can be used particularly preferably. Specifically, the adhesive tape according to the present invention may be preferably used to fix a touch panel portion of a portable electronic device such as a smartphone or a tablet terminal or to fix a display panel portion of an on-vehicle electronic device such as a car navigation system. it can.

  The shape of the pressure-sensitive adhesive tape according to the present invention is not particularly limited, and may be rectangular or the like. However, since it is suitable for fixing a touch panel portion or a display panel portion as described above, a frame shape is preferable. In addition, the pressure-sensitive adhesive tape according to the present invention is excellent in alcohol resistance, and can maintain its adhesive strength even when a disinfectant, a washing solution, an alcoholic beverage, or the like is attached. it can.

  The present invention will be described in more detail by way of the following examples, but the present invention is not limited to these examples.

Example 1
(1) Production of (Meth) Acrylate Copolymer Ethyl acetate was added as a polymerization solvent into the reaction vessel, and after bubbling with nitrogen, the reaction vessel was heated while refluxing nitrogen to start refluxing. Subsequently, a polymerization initiator solution in which 0.1 part by weight of azobisisobutyronitrile was diluted 10-fold with ethyl acetate as a polymerization initiator was charged into the reaction vessel. Subsequently, 48 parts by weight of 2- (perfluorohexyl) ethyl acrylate (13F), 34 parts by weight of 2-ethylhexyl acrylate (2EHA), 15 parts by weight of methyl acrylate (MA), 3 parts by weight of acrylic acid (AAc) for 2 hours It was added dropwise over time. After completion of the dropwise addition, a polymerization initiator solution in which 0.1 part by weight of azobisisobutyronitrile is diluted 10-fold with ethyl acetate as a polymerization initiator is again introduced into the reaction vessel, and the polymerization reaction is carried out for 4 hours. An acrylate copolymer-containing solution was obtained.

(2) Production of adhesive tape Triglyme (boiling point 216) as a compound represented by the general formula (1) with respect to 100 parts by weight of the (meth) acrylate copolymer in the obtained (meth) acrylate copolymer-containing solution 5 parts by weight were added. Furthermore, 1.5 parts by weight (solid component ratio) of Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent (3 parts by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent) and an adhesive solution Prepared. The pressure-sensitive adhesive solution is coated on a 75 μm-thick release-treated PET film so that the thickness of the pressure-sensitive adhesive layer after drying is 35 μm, and then dried at 110 ° C. for 5 minutes to form a pressure-sensitive adhesive layer. The Two pressure-sensitive adhesive layers were prepared, and both sides of 50 μm thick as a substrate were transferred onto both sides of a corona-treated PET film, respectively, and aged at 40 ° C. for 48 hours to obtain a double-sided pressure-sensitive adhesive tape.

(3) Measurement of Gel Fraction The obtained double-sided pressure-sensitive adhesive tape was cut into a 20 mm × 40 mm flat rectangular shape to prepare a test piece, and the weight was measured. After immersing the test piece in ethyl acetate at 23 ° C. for 24 hours, the test piece was removed from ethyl acetate and dried at 110 ° C. for 1 hour. The weight of the test piece after drying was measured, and the gel fraction was calculated using the following formula (1).
Gel fraction (% by weight) = 100 × (W ₂ −W ₀ ) / (W ₁ −W ₀ ) (1)
(W ₀ : Weight of base material, W ₁ : Weight of test piece before immersion in ethyl acetate, W ₂ : Weight of test piece after immersion in ethyl acetate, dried)

(Examples 2 to 18, Comparative Examples 1 to 5)
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the monomer composition and the type and amount of the additive were changed as described in Table 1 or 2. In addition, the compound of Table 1 or 2 used the following.
3F: 2,2,2-trifluoroethyl acrylate BA: butyl acrylate monoglyme: ethylene glycol dimethyl ether, boiling point 85.2 ° C.
Diglyme: compound represented by the general formula (1), boiling point 162 ° C.
Tetraglyme: compound represented by the general formula (1), boiling point 276 ° C.
Triethylene glycol di (2-ethylhexanoate): diol ester (compound represented by general formula (2-3)), boiling point 344 ° C.
Dioctyl adipate: Dicarboxylic acid ester (compound represented by the general formula (2-1)), boiling point 335 ° C.
Dioctyl phthalate: Dicarboxylic acid ester (compound represented by the general formula (2-2)), boiling point 385 ° C.
Dibutyl phthalate: Dicarboxylic acid ester (compound represented by the general formula (2-2)), boiling point 340 ° C.

Evaluation The following evaluation was performed about the double-sided adhesive tape obtained by the Example and the comparative example. The results are shown in Table 1 or 2.

(1) 180 ° peel adhesion (180 ° peel test)
The obtained double-sided pressure-sensitive adhesive tape was cut into a 5 mm wide strip to prepare a test piece, and the release film on one side was peeled and removed to expose the pressure-sensitive adhesive layer. After placing this test piece on a stainless steel plate with the adhesive layer facing the stainless steel plate, the test piece and the stainless steel are reciprocated by moving a 2 kg rubber roller once at a speed of 300 mm / min on the test piece. I stuck it to the board. Thereafter, it was allowed to stand at 23 ° C. for 24 hours to prepare a test sample.
According to JIS Z0237, a tensile test in the direction of 180 ° was performed at a peeling speed of 300 mm / min, and 180 ° peeling was performed to measure adhesion (N / mm) (before immersion in IPA / aqueous solution). Thereafter, the test sample was immersed in a bath of a mixture (alcohol) of 75% by weight of IPA and 25% by weight of water at a temperature of 60 ° C. and a humidity of 90% for 24 hours. After taking it out, the adhered liquid was lightly wiped off and allowed to stand for 24 hours. Thereafter, the 180 ° peel adhesion (N / mm) was measured in the same manner as the 180 ° peel adhesion (N / mm) (before IPA / water solution immersion). The 180 ° peel adhesion after immersion of the IPA / water solution was evaluated as follows from the residual adhesion ratio (%) obtained by dividing the 180 ° peel adhesion before immersion by the 180 ° peel adhesion.
:: residual adhesion ratio 80% or more ○: residual adhesion ratio 60% or more, less than 80% Δ: residual adhesion ratio 50% or more, less than 60% ×: residual adhesion ratio less than 50%

(2) Evaluation of impact resistance (drop impact test)
The schematic diagram of the drop impact test of the double-sided adhesive tape obtained by the Example and the comparative example in FIG. 1 is shown. The obtained double-sided pressure-sensitive adhesive tape was punched into an outer diameter of 46 mm, a length of 61 mm, an inner diameter of 42 mm, and a length of 57 mm to prepare a frame-shaped test piece of 2 mm in width. Next, as shown in FIG. 1 (a), the square hole of the test piece 1 in which the release film was peeled off from a polycarbonate plate 3 of 2 mm thickness with a square hole of 38 mm wide and 50 mm long at the center It stuck so that it was located in the center. Thereafter, a polycarbonate plate 2 having a width of 55 mm, a length of 65 mm, and a thickness of 1 mm was pasted from the upper surface of the test piece 1 so that the test piece 1 was positioned approximately at the center, and the test device was assembled. Thereafter, a pressure of 5 kgf was applied for 10 seconds from the side of the polycarbonate plate located on the upper surface of the test device, and the polycarbonate plates and the test pieces located above and below were pressure-bonded to each other.

As shown in FIG. 1 (b), the manufactured test device was turned over and fixed to a support, and an iron ball 4 with a weight of 300 g passing through the square hole was dropped so as to pass through the square hole. The height at which the iron balls were dropped was gradually increased, and the height at which the iron balls dropped when the test piece and the polycarbonate plate were peeled off by the impact applied by the drop of the iron balls was measured.
Based on the obtained measured values, the drop impact resistance was determined according to the following criteria.
:: height of iron ball at peeling is 55 cm or more ○: height of iron ball at peeling is 50 cm or more, less than 55 cm ×: height of iron ball at peeling is less than 50 cm

ADVANTAGE OF THE INVENTION According to this invention, the adhesive which makes alcohol resistance and impact resistance compatible can be provided. Further, according to the present invention, it is possible to provide a pressure-sensitive adhesive tape having the above-mentioned pressure-sensitive adhesive as a pressure-sensitive adhesive layer.

1 Double-sided adhesive tape test piece (frame shape)
2 Polycarbonate board 3 Polycarbonate board 4 Iron ball

Claims (5)

(Meth) acrylate copolymer having a content of 30 to 70% by weight of a constituent unit derived from fluorine-containing (meth) acrylate, and a compound represented by the following general formula (1) having a boiling point of 160 ° C. or more An adhesive characterized in that it contains

In general formula (1), m represents an integer of 1 or more, n represents an integer of 1 to 10, and R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms.   Containing a (meth) acrylate copolymer having a content of 30 to 70% by weight of a constituent unit derived from fluorine-containing (meth) acrylate, and a dicarboxylic acid ester or diol ester having a boiling point of 160 ° C. or higher Characteristic adhesive. The dicarboxylic acid ester is a compound represented by the following general formula (2-1) or (2-2), and the diol ester is a compound represented by the following general formula (2-3), (2-4) or (2-5) The pressure-sensitive adhesive according to claim 2, which is a compound represented by

R ¹ , R ² and R ^{3 in the} general formula (2-1) each represent a hydrocarbon group having 1 to 10 carbon atoms.

R ¹ and R ² in the general formula (2-2) each represent a hydrocarbon group having 1 to 10 carbon atoms, Ar represents an aromatic hydrocarbon group, and the bonding position of the aromatic hydrocarbon group is particularly preferably It is not restricted.

In General Formula (2-3), m represents an integer of 1 or more, n represents an integer of 1 to 10, and R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms.

R ¹ , R ² and R ^{3 in the} general formula (2-4) each represent a hydrocarbon group having 1 to 10 carbon atoms.

In the general formula (2-5), R ¹ and R ² each represent a hydrocarbon group having 1 to 10 carbon atoms, Ar represents an aromatic hydrocarbon group, and the bonding position of the aromatic hydrocarbon group is particularly preferably It is not restricted.   The said (meth) acrylate copolymer is a copolymer which has a structural unit derived from the alkyl (meth) acrylate which further has a C6 or more alkyl group, The claim is any 1-3 as described in any one of Claims 1-3. Adhesive.   The adhesive tape which has an adhesive as described in any one of Claims 1-4 as an adhesive layer in at least one surface.

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