KR20100114460A - Ultraviolet curing adhesive composition - Google Patents

Abstract

The present invention provides a compound having a (meth) acrylic polymer (component A), a carboxylic acid having a polymerizable unsaturated group (component B), a photopolymerization initiator (component C), a silane coupling agent (component D), and another polymerizable unsaturated group ( Component E), component A contains 0.5 to 20 mmol of (meth) acryloyl-based functional groups per 100 g of polymer in the side chain, a glass transition temperature of -55 ° C to 0 ° C, and a weight average molecular weight of 200,000 to 100 It is a polymer in a million range, C component is an acylphosphine oxide type photoinitiator, D component is a silane compound which has an epoxy-type functional group, and contains A component, B component, C component, D component, and E component in predetermined ratio. It provides an ultraviolet curable pressure-sensitive adhesive composition.

Description

UV curable adhesive composition {ULTRAVIOLET CURING ADHESIVE COMPOSITION}

The present invention relates to an ultraviolet curable pressure-sensitive adhesive composition in which the adhesive force is expressed by ultraviolet irradiation.

In recent years, electronic image display devices (electronic displays) such as plasma displays and liquid crystal displays have become widespread. In a plasma display, it is necessary to bond an antireflection film for improving visibility to the display surface, and also for a liquid crystal display, it is necessary to bond a polarizing plate or another functional film to the surface or the inner surface of the display. have. The use of the adhesive using a (meth) acrylic-type polymer is increasing rapidly in the use which makes these functional films stick.

Conventionally, in the use which adheres a functional film, the adhesive made by melt | dissolving a (meth) acrylic-type polymer in an organic solvent is made into a main body, and expresses adhesive force by adding and heating a heat crosslinking agent before use with respect to this main body. The so-called thermosetting adhesive has been used (see Patent Documents 1 and 2). Such a thermosetting adhesive is heat-treated by adding a thermal crosslinking agent to a main body, coating the surface of a functional film, and the like, heating the solvent powder contained in the main body by heating, and curing the mixture under normal temperature or heating conditions for several days. The crosslinking agent causes a crosslinking reaction to exhibit stable adhesion performance.

For example, Patent Literature 1 uses an alkyl (meth) acrylate and an unsaturated carboxylic acid as a monomer unit, and a weight average molecular weight of 500,000 or more acrylic polymer (A), an alkyl (meth) acrylate and an unsaturated carboxylic acid are monomer units. The pressure-sensitive adhesive composition for optical members comprising an acrylic polymer (B) having a weight average molecular weight of 0.2 to 50,000, a silane coupling agent, and a thermal crosslinking agent having a greater carboxylic acid equivalent than the acrylic polymer (A) is disclosed. . Further, Patent Document 1 discloses that the pressure-sensitive adhesive composition is produced in a state containing a solvent, and dried and crosslinked at 110 ° C. for 5 minutes to form an pressure-sensitive adhesive layer, followed by curing at a high temperature of 50 ° C. for 24 hours. An example of obtaining an optical member is disclosed.

In addition, Patent Document 2 discloses an active energy ray-curable pressure-sensitive adhesive composition for an optical laminate containing an ethylenically unsaturated group-containing acrylic resin, a photopolymerization initiator, and a silane compound. In addition, Patent Document 2 discloses that it is preferable to use a thermal crosslinking agent after diluting with a solvent so that the pressure-sensitive adhesive composition has a concentration of 10 to 20% by mass, and an example of performing long-term curing of 4 days at a high temperature of 40 ° C is given. Is disclosed.

Although such thermosetting adhesives have advantages such as good adhesiveness, high durability, high coating accuracy, and the like, the problem was that such curing (aging) was required. That is, since the product cannot be used immediately and requires a period and a place for curing, the problem remains in that the handling of the product is not only complicated, but also a storage cost is incurred.

Therefore, the ultraviolet curing adhesive which does not require high temperature and long-term curing by using the UV curing component which has a polymerizable unsaturated group is proposed. For example, the ultraviolet curable resin composition which has the acryl copolymer of a predetermined weight average molecular weight, the monomer which has two unsaturated double bonds in a molecule | numerator, has the alkylene glycol chain in a molecule | numerator, and a photoinitiator is proposed (patent document) 3).

Moreover, the ultraviolet curable adhesive composition which consists of a reactive polymer (A) in which a double bond was introduced, the (meth) acrylic acid ester monomer (B), the monofunctional monomer (C) copolymerizable with (B), a photoinitiator, etc. (D) It is proposed (refer patent document 4).

Moreover, this inventor also contains the monomer which has a reactive polymer, a photoinitiator, and a polymerizable double bond, The said reactive polymer contains the repeating unit derived from a (meth) acrylic-type monomer in a main chain, and a (meth) acryloyl-type functional group in a side chain. The ultraviolet curable adhesive composition which is the modified (meth) acrylic-type polymer which has the thing was proposed (refer patent document 5).

Japanese Patent Laid-Open No. 2004-263165 Japanese Patent Laid-Open No. 2006-316231 Japanese Patent Laid-Open No. 2006-312664 Japanese Patent Laid-Open No. 2001-64593 Japanese Patent Laid-Open No. 2006-282805

In the ultraviolet curable pressure-sensitive adhesive compositions described in Patent Literatures 3 to 5, when the ultraviolet ray is irradiated, a photopolymerization initiator acts, and the adhesive force is expressed by the progress of the polymerization reaction of the polymerizable monomer or the reactive polymer. Therefore, there is an advantage that the adhesive force can be expressed almost simultaneously with the ultraviolet irradiation without heating in the expression of the adhesive force. Moreover, since a thermal crosslinking agent is not contained in an adhesive, it has the outstanding characteristic which a thermosetting adhesive does not require a curing period in manufacture of an adhesive (no curing).

However, the ultraviolet curable pressure sensitive adhesive tends to be inferior in optical durability and re-peelability compared with the thermosetting pressure sensitive adhesive, and the coating suitability at high speed, the ultraviolet curability under an air atmosphere, and the like have not been sufficiently satisfied. In particular, the pressure-sensitive adhesive used for bonding a functional film to an electronic display is further improved in technological level, such as improvement in productivity (coating speed), improvement in coating accuracy, and thinning of the pressure-sensitive adhesive layer due to thinning of the product. It was required, and there was still a problem to be solved.

This invention is made | formed in order to solve the subject of the prior art mentioned above, Taking advantage of the ultraviolet curable adhesive which hardening is unnecessary, it is excellent in ultraviolet curability in an air atmosphere, and is excellent in optical durability, repeelability, and productivity ( It is to provide an ultraviolet curable pressure-sensitive adhesive composition having a performance comparable to a thermosetting pressure-sensitive adhesive in terms of coating speed) and coating aptitude (coating accuracy, thinning of the pressure-sensitive adhesive layer, etc.).

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to solve the subject of the prior art mentioned above, and, as a result, polymerizable properties, such as a crosslinkable (meth) acrylic-type polymer and (meth) acrylic acid, in which a polymeric (meth) acryloyl group was introduce | transduced into the side chain. The present invention was found to be solved by using a polymerizable carboxylic acid having an unsaturated group, an acylphosphine oxide photopolymerization initiator, and a silane coupling agent having an epoxy functional group at a predetermined composition ratio. Specifically, the following ultraviolet curable pressure-sensitive adhesive composition is provided by the present invention.

[1] at least one of (meth) acrylic polymer (component A), carboxylic acid having a polymerizable unsaturated group and an oligomer thereof (component B), a photopolymerization initiator (component C), a silane coupling agent (component D) and the above-mentioned A A component (component E) having a polymerizable unsaturated group other than the component and the B component as a constituent component, wherein the component A contains a repeating unit derived from a (meth) acrylic monomer in the main chain, It has a (meth) acryloyl-type functional group containing one frame | skeleton, contains 0.5-20 mmol of said (meth) acryloyl-type functional groups per 100g of polymers, and glass transition temperature (Tg) is -55 degreeC-0 degreeC, and weight A crosslinkable (meth) acrylic polymer having an average molecular weight (Mw) in the range of 200,000 to 1 million, C component is an acylphosphine oxide photopolymerization initiator, D component is a silane coupling agent having an epoxy functional group, A sex When the total amount of minutes and the B component is 100 parts by mass, 80 to 99.5 parts by mass of the A component, 0.5 to 20 parts by mass of the B component, 0.05 to 3 parts by mass of the C component, and 0.1 to the D component The ultraviolet curable pressure-sensitive adhesive composition containing 5 parts by mass to 5 parts by mass of the E component.

[2] The above-mentioned [1], wherein the component A is a crosslinkable (meth) acrylic polymer having an alkoxysilyl functional group containing an alkoxysilyl skeleton in its side chain and containing 0.04 to 4 mmol of the alkoxysilyl functional group per 100 g of the polymer. The ultraviolet curable adhesive composition of description.

[3] The component E is 0.5 when the component E is a polyfunctional oligomer having two or more (meth) acryloyl functional groups per molecule, and the total amount of the component A and the component B is 100 parts by mass. The ultraviolet curable adhesive composition as described in said [1] or [2] containing 20 mass parts.

[4] The ultraviolet curable pressure-sensitive adhesive composition according to the above [3], wherein the E component is a polyfunctional oligomer having an aliphatic polyester as a basic skeleton and a weight average molecular weight (Mw) in a range of 1000 to 10,000.

[5] The ultraviolet curable pressure-sensitive adhesive composition according to the above [3], wherein the E component is a polyfunctional oligomer having a bisphenol as a basic skeleton and a weight average molecular weight (Mw) in a range of 400 to 2,000.

[6] The ultraviolet curable pressure-sensitive adhesive composition according to the above [1] or [2], which contains a benzophenone-based compound having a λ _maximum in a wavelength range of 350 to 400 nm as a ultraviolet absorber (F component).

[7] The ultraviolet curable pressure-sensitive adhesive composition according to the above [1] or [2], wherein the C component is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

The ultraviolet curable pressure-sensitive adhesive composition of the present invention does not require curing, and is excellent in ultraviolet curability under an air atmosphere, in terms of optical durability, re-peelability, productivity (coating speed), coating aptitude (coating accuracy, thinning of the pressure-sensitive adhesive layer, etc.). It has the performance comparable to a thermosetting adhesive.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the ultraviolet curable adhesive composition of this invention is demonstrated concretely. However, this invention includes all embodiment provided with the specific matter of this invention, and is not limited to embodiment shown below.

[1] definitions, etc .:

When referring to "(meth) acrylic polymer" in the following description, the repeating unit (henceforth "the repeating unit derived from monomer X") may be simply described as "X unit" in a main chain in a main chain. It means the polymer containing).

In addition, when referring to a "main chain" with respect to a polymer (including an oligomer), it means the carbon chain which has the most carbon number in the said polymer. On the other hand, the term "side chain" shall mean a carbon chain having fewer carbon atoms than the main chain branched from the polymer main chain (carbon chain with the highest carbon number).

In addition, a "polymerizable unsaturated group" means an unsaturated bond which has a polymerizability, ie, a polymerizable double bond, such as a vinyl group, and a polymerizable triple bond, such as an acetylene group. As long as these unsaturated bonds have polymerizability, the structure is not specifically limited. For example, like cyclohexenyl group, it may comprise a part of cyclic structure.

[2] The composition of the present invention:

The ultraviolet curable adhesive composition of this invention is a (meth) acrylic-type polymer (component A), the carboxylic acid which has a polymerizable unsaturated group, and its oligomers, at least 1 type (component B), a photoinitiator (component C), and a silane coupling agent (D Component) and the compound (E component) which has a polymerizable unsaturated group other than the said A component and the said B component as an constituent component. Hereinafter, it demonstrates for every component.

[2-1] (meth) acrylic polymer (component A):

"(Meth) acrylic-type polymer" is a polymer containing the repeating unit derived from a (meth) acrylic-type monomer in a main chain. The adhesive composition of this invention uses the "crosslinkable (meth) acrylic-type polymer" which has a reactive functional group which can be bridge | crosslinked to a side chain as "(meth) acrylic-type polymer".

[2-1A] Backbone:

The repeating unit derived from a (meth) acrylic-type monomer is contained in the principal chain of a "crosslinkable (meth) acrylic-type polymer".

In general, "(meth) acrylic monomer" means acrylic acid, methacrylic acid or salts or esters thereof. Specifically, (meth) acrylates, such as ammonium (meth) acrylate, sodium (meth) acrylate, and potassium (meth) acrylate, other than acrylic acid and methacrylic acid; Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, i-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl ( (Meth) acrylic acid esters such as meth) acrylate, lauryl (meth) acrylate and cyclohexyl (meth) acrylate; Hydroxyl-containing (meth), such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate Acrylic esters etc. are mentioned.

It is preferable that A component contains the repeating unit derived from (meth) acrylic acid ester among the said (meth) acrylic-type monomer, and it is more preferable to include the repeating unit derived from ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate. It is preferable to include a repeating unit derived from ethyl acrylate or butyl acrylate, and more preferably to include a repeating unit derived from ethyl acrylate. It is because it becomes possible to exhibit favorable adhesive characteristics by including these repeating units.

In addition, the component A may be a homopolymer in which the main chain contains only one (meth) acrylic monomer unit, or may be a copolymer including two or more (meth) acrylic monomer units. However, when it is set as an adhesive and adhesive, it is preferable that it is a copolymer containing 2 or more types of (meth) acrylic-type monomer units because it is easy to adjust the physical property of the coating film (adhesive layer) precisely. In that case, it is especially preferable to include the repeating unit derived from ethyl acrylate and butyl acrylate.

In addition, it is sufficient for A component to contain a (meth) acrylic-type monomer unit, and does not require that every repeating unit is a (meth) acrylic-type monomer unit. That is, as long as the effect of this invention is not impaired, you may include monomeric units other than a (meth) acrylic-type monomer (it may describe as "other monomeric unit").

Although there is no restriction | limiting in particular about the kind of "monomers other than a (meth) acrylic-type monomer", For example, the monomer which has a polymerizable unsaturated bond can be used. Specifically, (meth) acrylamides, such as (meth) acrylamide; (Meth) acrylonitrile, such as (meth) acrylonitrile; Aromatic vinyls such as styrene and α-methylstyrene; Unsaturated carboxylic acids such as vinyl carboxylates such as vinyl acetate and vinyl propionate, maleic anhydride, itaconic acid and fumaric acid; N-vinyl lactams, such as N-vinylpyrrolidone and N-vinyl caprolactam, etc. are mentioned.

It is preferable that A component contains the repeating unit derived from (meth) acrylonitrile, especially an acrylonitrile among the said "monomers other than a (meth) acrylic-type monomer." By including these repeating units, the cohesion force of an adhesive can be improved and re-peelability can be improved.

In the (meth) acrylic monomer unit of component A, the content rate of the (meth) acrylic monomer unit is preferably 50 mass% or more when the total of monomer units constituting the main chain of the (meth) acrylic polymer is 100 mass%. And it is more preferable that it is 60 mass% or more, and it is especially preferable that it is 70 mass% or more. Especially, it is preferable that all the principal chains are comprised by the (meth) acrylic-type monomer unit. Since the adhesive characteristic tends to fall that the content rate of a (meth) acrylic-type monomer unit is less than 50 mass%, it is unpreferable.

As a specific composition in the case of containing monomers other than a (meth) acrylic-type monomer, the (meth) acrylic-type polymer which has a (meth) acrylic acid ester unit and an acrylonitrile unit is preferable. Especially, when the sum total of the monomeric units which comprise the main chain of a (meth) acrylic-type polymer is 100 mass%, 70-98.9 mass% of (meth) acrylic acid ester units, 1-20 mass% of acrylonitrile units, Particularly preferred is a (meth) acrylic polymer containing 0.1 to 10% by mass of other monomer units.

[2-1B] Side Chain:

The side chain of "crosslinkable (meth) acrylic-type polymer" has a crosslinkable reactive functional group. By having the reactive functional group which can be bridge | crosslinked to a side chain, A component is bridge | crosslinked as well as other polymerization components (for example, B component mentioned later, E component etc.) which A component differs by ultraviolet irradiation. Therefore, the concentration of the gel powder of the pressure-sensitive adhesive layer to be formed can be increased, and the pressure-sensitive adhesive layer having excellent adhesion performance and high strength and durability (especially optical and moist heat resistance) can be formed.

The "crosslinkable (meth) acrylic polymer" is a crosslinkable reactive functional group and has a (meth) acryloyl functional group containing at least a (meth) acryloyl skeleton in the side chain. In other words, what modified and introduce | transduced the (meth) acryloyl-type functional group by chemical formula with respect to the (meth) acrylic-type polymer used as a basic skeleton can be used.

In this specification, when referring to "functional group containing a (meth) acryloyl skeleton", the functional group containing the "acryloyl skeleton" shown by following formula (1) or the "methacryloyl skeleton" shown by following formula (2) It also means that all or part of the hydrogen atoms constituting the acryloyl skeleton and the methacryloyl skeleton are substituted with other atoms or functional groups. In this specification, these functional groups may be called "(meth) acryloyl-type functional group."

As a typical example, an acryloyl group, a methacryloyl group, etc. are mentioned, for example. The acryloyl group is preferable at the point which can provide the outstanding polymerizability (and further ultraviolet curability), and the methacryloyl group is preferable at the point which is high in safety compared with the acryloyl group.

In addition, the (meth) acryloyl-based functional group does not need to be a functional group having a structure in which the acryloyl skeleton or the methacryloyl skeleton can be directly bonded to the main chain. It may also be a functional group having a structure capable of being bonded to the main chain indirectly through a ruler or a functional group (for example, acryloyloxy group or the like).

The content of the (meth) acryloyl functional group also varies depending on the structure of the main chain, the weight average molecular weight, the glass transition temperature, the adhesive physical properties, and the like. However, it is necessary to contain 0.5-20 mmol of (meth) acryloyl-type functional groups per 100g of polymers, It is preferable to contain 0.5-15 mmol, It is especially preferable to contain 0.5-10 mmol. For example, if it is a crosslinkable (meth) acrylic-type polymer whose weight average molecular weight is 420,000, it is preferable to have 2.1-84 (meth) acryloyl-type functional groups per polymer, and it is more preferable to have 2.1-63. It is especially preferable to have 2.1 to 42 pieces.

If the content of the (meth) acryloyl functional group is less than 0.5 mmol / 100 g, the gel content cannot be sufficiently increased, and the strength of the pressure-sensitive adhesive layer may be insufficient. In this case, 1) When the film product etc. which coated the adhesive composition were wound in roll shape, the adhesive composition is pressed and broken by the weight of the film product itself, and the adhesive composition is formed from the end or side edge of the roll. There is a fear that this looming problem will occur. Moreover, 2) the embossing film in which the unevenness | corrugation was formed may be used as a protective film, such as a film product which coated the adhesive composition in recent years, and there exists a possibility of causing the problem that the embossed pressed trace generate | occur | produces in the said film product etc .. In order to solve such a problem, it is preferable to make content into 0.5 mmol / 100 g or more. However, when it exceeds 20 mmol / 100 g, there exists a possibility that the moisture heat resistance of an adhesive may fall.

It is also preferable that the side chain of a "crosslinkable (meth) acrylic-type polymer" has an alkoxysilyl-type functional group containing the alkoxysilyl frame | skeleton shown in following formula (3) in addition to a (meth) acryloyl-type functional group as a reactive functional group.

(Wherein R represents an alkyl group which may be substituted.)

The polymer which has an alkoxysilyl functional group in a side chain is excellent in durability, especially heat resistance and heat and moisture resistance, when a glass material is used as a to-be-adhered body. Specifically, it exhibits excellent adhesion even under high temperature conditions or under high temperature and high humidity conditions, and is characterized by excellent adhesion characteristics. Moreover, by performing these modifications, even if the amount of B components is small, the adhesive composition which hardly reduces adhesiveness even under heat-resistant and moisture-resistant heat conditions can be obtained.

In the present specification, the term "alkoxysilyl skeleton" means a skeleton in which at least one alkoxy group is bonded to a silicon atom, as shown in the above formula (3). Therefore, the "functional group containing an alkoxysilyl skeleton" includes functional groups having a silicon atom in which any group other than an alkoxy group or a functional group other than the alkoxy group is bonded. In this specification, these functional groups may be called "alkoxysilyl-type functional groups."

Specifically, a trialkoxy silyl group, a dialkoxy silyl group, a monoalkoxy silyl group, etc. are mentioned. Especially, a trialkoxy silyl group is especially preferable because it can introduce | transduce using the trialkoxysilane derivative which is comparatively easy to obtain.

In addition, the alkoxysilyl functional group does not need to be a functional group having a structure in which the alkoxysilyl skeleton can be directly bonded to the main chain, and may be a functional group having a structure in which the alkoxysilyl skeleton can be indirectly bonded through any atom or functional group ( For example, a trialkoxy silyl alkyl group.

The preferable content of the alkoxysilyl functional group also varies depending on the structure of the main chain, the weight average molecular weight, the glass transition temperature, and the like. However, it is preferable to contain 0.04-4 mmol of alkoxysilyl-type functional groups per 100 g of polymers, It is more preferable to contain 0.04-2 mmol, It is especially preferable to contain 0.04-1 mmol. For example, if it is a crosslinkable (meth) acrylic-type polymer whose weight average molecular weight is 420,000, it is preferable to have 0.17-17 pieces of alkoxysilyl-type functional groups per polymer, It is more preferable to have 0.17-8.5 pieces, 0.17 It is especially preferable to have from 4.2 pieces.

When the content of the alkoxysilyl functional group is less than 0.04 mmol / 100 g, the effect of modification by the alkoxysilyl functional group (specifically, the effect of durability, in particular, excellent in heat resistance and moisture heat resistance when using a glass material as an adherend) There is a fear that it will not be obtained sufficiently. On the other hand, when it exceeds 4 mmol / 100 g, although it also changes according to a polymer composition etc., there exists a tendency which raises the viscosity of a polymer with time.

Although the manufacturing method of a crosslinkable (meth) acrylic-type polymer is not specifically limited, For example, about the (meth) acrylic-type polymer used as a basic skeleton, a (meth) acryloyl-type functional group and an alkoxy silyl-type functional group are introduce | transduced by chemical formula. It can manufacture by a method (chemical modification method).

As a specific example of a chemical modification method, the (meth) acrylic-type polymer which has a hydroxyl group is made into a base polymer, for example, and the (meth) acrylic-type compound which has an isocyanate group, and the alkoxysilane type compound which has an isocyanate group directly in the hydroxyl group of this base polymer is directly. The method of introducing a (meth) acryloyl-type functional group and the alkoxy silyl-type functional group by combining is mentioned (direct bonding method).

"(Meth) acrylic-type polymer which has a hydroxyl group" can be obtained by copolymerizing hydroxyl-containing (meth) acrylic acid esters, such as 2-hydroxyethyl acrylate, and another (meth) acrylic-type monomer. As the "(meth) acrylic compound having an isocyanate group", for example, 2-methacryloyloxyethyl isocyanate (trade name: Carens MOI, manufactured by Showa Denko) and 2-acryloyloxyethyl isocyanate (trade name: Ka Lens AOI, the Showa Denko company make, 2- (2-methacryloyloxyethyloxy) ethyl isocyanate (brand name: Carens MOIEG, the Showa Denko company make), etc. are mentioned. On the other hand, as an alkoxysilane type compound which has an isocyanate group, 3-isocyanate propyl triethoxysilane (brand name: KBE-9007, the Shin-Etsu Chemical Co., Ltd. product) etc. are mentioned, for example.

Moreover, as a chemical modification method, a polyfunctional compound, such as a polyisocyanate compound, is bonded to the hydroxyl group of a base polymer, and indirectly couple | bonds the (meth) acrylic-type compound which has a hydroxyl group, or the alkoxysilane type compound which has a hydroxyl group through this polyfunctional compound. The method of introducing a (meth) acryloyl-type functional group and the alkoxy silyl-type functional group can also be employ | adopted (indirect coupling method).

As a "polyisocyanate compound", methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), isophorone diisocyanate (IPDI), etc. are mentioned, for example. As a "(meth) acrylic-type compound which has a hydroxyl group", the hydroxyl group containing (meth) acrylic acid ester etc. which were mentioned above are mentioned. As "an alkoxysilane type compound which has a hydroxyl group", 3-hydroxypropyl triethoxysilane etc. are mentioned, for example.

The manufacturing method of a base polymer is not specifically limited, Conventionally well-known methods, such as solution polymerization, suspension polymerization, and block polymerization, can be used. For example, when using solution polymerization, the polymerization initiator is made into the ethylenically unsaturated monomer mixture which consists of a (meth) acrylic-ester type monomer component and the ethylenically unsaturated monomer component copolymerizable with this as needed, in an appropriate solvent, such as an organic solvent. Is added and polymerized by a method of heating and stirring under a nitrogen stream.

As the base polymer, a commercially available acrylic copolymer can also be used. For example, brand name: Paracron AW4500H (solid content: 40%, Mw: 320,000, Tg: -8 degreeC, toluene solvent, Negami Kogyo Co., Ltd.) and brand name: Paraclon AS3000E (solid content: 30%, Mw: 65) However, Tg: -36 degreeC, a toluene solvent, Negami Kogyo Co., Ltd.) etc. can be used.

As a manufacturing method of a crosslinkable (meth) acrylic-type polymer, about an alkoxysilyl-type group, it inserts into the skeleton of a base polymer by copolymerizing the monomer which has an alkoxysilyl-type group with another monomer, and about a (meth) acryloyl-type group, The method introduce | transduced by the chemical formula into the base polymer in which the alkoxy silyl-type functional group was inserted is mentioned (polymerization method).

When explaining the polymerization method more specifically, the monomer mixture containing a (meth) acrylic monomer, the monomer which has a hydroxyl group, and the monomer which has an alkoxysilyl-type functional group is polymerized, and the 1st which has the said alkoxysilyl-type functional group and hydroxyl group in a side chain is described. A modified (meth) acrylic polymer is obtained, the first modified (meth) acrylic polymer is used as a base polymer, and a (meth) acryloyl functional group is introduced by a chemical formula into the hydroxyl group of the base polymer to obtain a second crosslinkability (meth A method of obtaining an acrylic polymer.

Examples of the "monomer having an alkoxysilyl functional group" include methacryloyloxytrialkoxysilane, acryloyloxytrialkoxysilane, vinyltrialkoxysilane, and the like. Especially, since the reactivity at the time of superposition | polymerization is high, it is preferable to use methacryloyloxy trialkoxysilane or acryloyloxy trialkoxysilane, and it is especially preferable to use acryloyloxy trialkoxysilane.

[2-1C] Average Molecular Weight:

A component has the weight average molecular weight (Mw) in the range of 200,000-1 million. If the weight average molecular weight is less than 200,000, it is not preferable because the residue on the adherend increases when the adhesive is used, which tends to contaminate the adherend. On the other hand, when it exceeds 1 million, miscibility with a solvent and a monomer becomes poor, the adhesion loss at the time of composition manufacture increases, and when coating an adhesive, there exists a possibility that a problem, such as deterioration of handling of a coating liquid, a fall of coating property, may arise. have. More specifically, a coating root may occur in a film to be coated or the like, or the coating solution may increase like a thread. It is not preferable that the coating liquid increases like a yarn because the viscosity of the coating liquid is increased by the rotation of the coating roll.

In order to acquire the said effect more reliably, it is further more preferable that it is in the range of 250,000-80,000, and it is especially preferable that it is in the range of 400,000-60,000.

The weight average molecular weight is a polymerization condition at the time of polymerizing the (meth) acrylic polymer which becomes a main chain, for example, the kind and quantity of a polymerization initiator, the kind and quantity of a chain transfer agent, the kind and quantity of a solvent, reaction temperature, reaction time, etc. By controlling appropriately, it can adjust within the said range. Moreover, what has a desired weight average molecular weight can be suitably selected from the commercially available (meth) acrylic-type polymer, and this can also be modified.

In addition, when it says "a weight average molecular weight" in this specification, it shall mean the weight average molecular weight of polystyrene conversion measured by the GPC method (Gel Permeation Chromatography Method (GPC method)).

Specifically, it is preferable to melt | dissolve in tetrahydrofuran (THF) so that solid content of each sample may be 0.025%, and to measure this solution on the following conditions. (1) a GPC measuring device; High speed GPC apparatus HLC-8820 (trade name, manufactured by Tosoh Corporation), (2) column; TSK-GEL series (brand name, the Tosoh Corporation make), (3) mobile phase; THF, (4) flow rate; 1 ml / min, (5) column temperature; 40 ° C., (6) detector; RI, UV, (7) equivalent; polystyrene.

[2-1D] glass transition temperature (Tg):

A component is the thing whose glass transition temperature (Tg) is in the range of -55-0 degreeC. By carrying out glass transition temperature in this range, when it is set as an adhesive, appropriate adhesive performance will be expressed. When glass transition temperature exceeds 0 degreeC, since adhesive strength falls when it is set as an adhesive, or there exists a tendency for coating property to fall with the fall of miscibility with a solvent, it is unpreferable. On the other hand, if it is less than -55 deg. C, it is not preferable because the residue on the adherend increases when the adhesive is used, which tends to contaminate the adherend. In order to acquire these effects more reliably, it is preferable that it is in the range of -40--10 degreeC, and it is still more preferable that it is in the range of -30--20 degreeC.

Glass transition temperature can be adjusted in the said range by suitably controlling the kind and ratio of the repeating unit which comprises the (meth) acrylic-type polymer used as a principal chain. Since the monomer M _1, M _2, and and and M _n the glass transition temperature (theoretical value) of the polymer P is composed of a repeating unit, the formula of Fox derived from it can be calculated from (Equation 1), the mathematics The type and ratio of repeating units can be adjusted with reference to the formula.

[Equation 1]

1 / TgP = r ₁ / TgM ₁ + r ₂ / TgM _{2 ...} + r _n / TgM _n

(TgP: glass transition temperature (K) of polymer P, TgM ₁ : glass transition temperature (K) of homopolymer of monomer M ₁ , TgM ₂ : glass transition temperature (K) of homopolymer of monomer M ₂ , TgM _n : glass transition temperature (K) of homopolymer of monomer M _n , r ₁ : mass fraction of monomer M ₁ unit in polymer P, r ₂ : mass fraction of monomer M ₂ unit in polymer P, r _n : polymer Mass fraction of monomeric M _n units at P)

More specifically, since the crosslinkable (meth) acrylic polymer constituting the component A has a relatively low glass transition temperature of -55 to 0 ° C, a monomer having a relatively low glass transition temperature of the homopolymer during polymerization, eg For example, the homopolymer is free of the monomer mixture containing butyl acrylate (Tg: -55 deg. C), ethyl acrylate (Tg: -24 deg. C), 2-ethylhexyl acrylate (Tg: -85 deg. C) as a main component. A polymer having a desired glass transition temperature can be obtained by appropriately adding and polymerizing a monomer having a relatively high transition temperature such as methyl methacrylate (Tg: 105 ° C), styrene (Tg: 100 ° C) and the like. Moreover, what has a desired glass transition temperature can be suitably selected from the commercially available (meth) acrylic-type polymer, and this can also be modified.

In addition, when referring to "glass transition temperature" in this specification, it means the glass transition temperature measured based on JISK7121 (transition temperature measuring method of plastic).

[2-1E] Content:

Although content of the crosslinkable (meth) acrylic-type polymer which comprises A component differs also by the structure of the polymer of A component, the kind of to-be-adhered body, required adhesive characteristics, etc., when the total amount of A component and B component is 100 mass parts, It is necessary to set it as 80-99.5 mass parts. When content is less than 80 mass parts, since adhesive force tends to fall, it is not preferable. On the other hand, when it exceeds 99.5 mass parts, since durability of an adhesion layer tends to fall by lack of cohesion force, it is unpreferable.

In order to acquire the said effect more reliably, it is preferable to make content of A component into 85-99.5 mass parts, and it is more preferable to set it as 90-99.5 mass parts.

[2-2] Carboxylic acids (component B) having a polymerizable unsaturated group:

The composition of this invention contains at least 1 type (component B) of the carboxylic acid which has a polymeric unsaturated group, and its oligomer. By containing the component B, the ultraviolet curability is not impaired even in the presence of oxygen, the film strength and adhesion to the substrate are improved, and the adhesive composition is less likely to be deteriorated even under heat and moisture resistant conditions without using a heat crosslinking agent. Can be obtained. That is, curing is unnecessary for the expression of adhesive properties.

The "carboxylic acid having a polymerizable unsaturated group" means a carboxylic acid having a polymerizable double bond or a polymerizable triple bond. So-called unsaturated carboxylic acids, and more specifically, (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, cinnamic acid, and the like. Can be.

"Oligomer of the carboxylic acid which has a polymerizable unsaturated group" means that the weight average molecular weight is 10,000 or less as a polymer of the said carboxylic acid. For example, in addition to an acrylic acid dimer, the thing of the weight average molecular weight as 10,000 acrylic acid polymer is mentioned.

Although content of B component differs also with the structure of the polymer of A component, the kind of to-be-adhered body, required adhesion characteristics, etc., when making the total amount of A component and B component 100 mass parts, it is necessary to set it as 0.5-20 mass parts. When content is less than 0.5 mass part, there exists a tendency for the adhesive durability of an adhesion layer and optical durability to fall. On the other hand, when it exceeds 20 mass parts, there exists a tendency for the pool residue at the time of re-peeling to increase. In order to acquire the said effect more reliably, it is preferable to make content of B component into 0.5-15 mass parts, and it is more preferable to set it as 0.5-10 mass parts.

[2-3] Photopolymerization Initiator (C Component):

The composition of this invention contains a photoinitiator (component C) as a structural component. When added to a polymerization system, a photoinitiator means the additive which has the effect | action which causes a polymerization reaction by light irradiation. That is, the component C causes the polymerization reaction of the component A and the component B by the irradiation of ultraviolet rays, and contributes to the formation of the polymer derived from the component B, the crosslinked product of the component A and component B, and the crosslinked product of the components A. By such a property, the adhesive layer with high strength can be formed.

As a photoinitiator, photoinitiators, such as (alpha)-hydroxyacetophenone (brand name: Irgacure 184, Ciba Specialty Chemicals make), (alpha)-aminoacetophenone, a benzoin type compound, are known, for example. However, in the composition of this invention, an acyl phosphine oxide type compound is contained as a photoinitiator. This is because when the acyl phosphine oxide compound is contained, the color tone deterioration (yellowing) of the pressure-sensitive adhesive layer can be suppressed to an extremely slight level, and an adhesive excellent in optical characteristics and durability can be formed. In addition, when using the adhesive composition of this invention for the use etc. which bond a functional film to an electronic display, a ultraviolet absorber (F component) may be contained, In such a case, in the case of wavelength range different from the absorption wavelength of F component, It is because it is preferable to use the photoinitiator which causes the polymerization reaction of B component by ultraviolet-ray.

Generally, the absorption wavelength of a ultraviolet absorber is known as the area | region of about 250-380 nm. Therefore, the acylphosphine oxide type compound which causes a polymerization reaction by ultraviolet irradiation of wavelength 380 nm or more can be used preferably.

Moreover, as a photoinitiator which causes a polymerization reaction by ultraviolet irradiation of wavelength 380 nm or more, 2-benzyl-2- dimethylamino-1- (4-morpholinophenyl) -butanone-1 (brand name: Irgacure 369) (Alpha)-aminoalkyl phenone type compounds, such as the Ciba Specialty Chemicals company), etc. are also exist. However, when photoinitiators other than an acyl phosphine oxide type compound are used, UV-curable fall and yellowing of an adhesion layer generate | occur | produce.

An "acyl phosphine oxide type compound" is a compound which has an acyl phosphine oxide structure (refer Formula 4 below). That is, as long as it has an acyl phosphine oxide structure represented by following formula (4) in a part of the structure, it is contained in the "acyl phosphine oxide type compound" which is said to this invention in spite of the structure of another part. Therefore, among such various substances, an optimal substance can be appropriately selected according to the required performance (ultraviolet curability, color, etc.) as the resin composition and can be used as the C component.

(Wherein R represents an alkyl group which may be substituted or an aryl group which may be substituted.)

As an "acyl phosphine oxide type compound", for example, bis (2, 4, 6-trimethyl benzoyl)-phenyl phosphine oxide (brand name: Irgacure 819, the Ciba specialty chemicals company make), bis (2, 6-, Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (trade name: CGL403, manufactured by Ciba Specialty Chemicals Co., Ltd.), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name: Lucirin TPO, BASF Corporation) etc. are mentioned. Among them, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is particularly preferable because of excellent curing properties and little change in color tone of the coating film.

In addition, a high molecular compound is contained in an "acyl phosphine oxide type compound." That is, the polymer photoinitiator which the acyl phosphine oxide structure was introduce | transduced in a high molecular compound can also be used as C component. This polymer photoinitiator contains not only a so-called polymer (weight average molecular weight is about 50,000 or more) but also a so-called oligomer (weight average molecular weight is about 500 to 50,000). Such polymer photopolymerization initiator is required to have at least an acylphosphine oxide structure, but may also have a structure of another photopolymerization initiator. For example, what has a structure of another photoinitiator called a benzoin structure, a hydroxyacetophenone structure, an amino acetophenone structure, or a benzophenone structure in addition to an acyl phosphine oxide structure is mentioned.

Although content of C component differs also with the structure of the polymer of A component, the kind of to-be-adhered body, required adhesion characteristic, etc., when the total amount of A component and B component is 100 mass parts, you may be 0.05-3 mass parts. When content is less than 0.05 mass part, since an adhesive may not be hardened | cured or hardening may become inadequate, it is not preferable. On the other hand, when it exceeds 3 mass parts, since an adhesive may yellow, it is not preferable. In order to acquire the said effect more reliably, it is preferable to make content of C component into 0.1-1 mass part, and it is more preferable to set it as 0.1-0.5 mass part.

Moreover, acylphosphine oxide type photoinitiators are easy to be inhibited by oxygen, and it was difficult to use practically unless the conditions except oxygen, such as lamination processing, were excluded. The present inventors found that ultraviolet curing by an acylphosphine oxide type photoinitiator proceeds rapidly by coexisting B component (carboxylic acids having a polymerizable unsaturated group such as acrylic acid). Accordingly, under the air, ultraviolet curing with a small amount of photopolymerization initiator is enabled, thereby enabling the expression of adhesion performance by an acylphosphine oxide photopolymerization initiator. In the pressure-sensitive adhesive composition of the present invention, by dramatically reducing the amount of the initiator compared with the conventional ultraviolet curable pressure-sensitive adhesive, the amount of the residual initiator and the low molecular weight polymer can be reduced to improve the optical properties of the pressure-sensitive adhesive.

[2-4] Silane Coupling Agent (Component D):

The composition of this invention contains a silane coupling agent (component D) as a structural component. By mix | blending D component, favorable adhesiveness can be exhibited in the bonding use with adherends, such as glass. Moreover, by containing D component, even if there is little quantity of B component, the adhesive composition which hardly falls adhesive property under heat-resistant and moisture-resistant heat conditions can be obtained.

As D component, what is generally called a "silane coupling agent" can be used widely. Usually, as a silane coupling agent, the silane compound which has reactive functional groups, such as a glycidoxy group, a methacryloxy group, and an acryloxy group, is used. However, in the adhesive composition of this invention, the silane coupling agent which has an epoxy-type functional group is used as D component. "Epoxy functional group" means the functional group which has an epoxy ring, For example, glycidoxy group etc. are mentioned. The silane coupling agent which has an epoxy-type functional group is preferable at the point which can improve adhesiveness to glass substrates, such as a front plate of a plasma display.

As a specific compound, (gamma)-glycidoxy propyl trimethoxysilane (brand name: KBM-403 (made by Shin-Etsu Chemical Co., Ltd.), etc.), (gamma)-glycidoxy propyl triethoxysilane (brand name: KBE-403 (new product) And alkyl alkoxysilanes having glycidoxy groups such as γ-glycidoxypropylmethyldimethoxysilane. These silane coupling agents may be used individually by 1 type, and may be used in combination of 2 or more type.

Although content of D component changes with the structure of the polymer of A component, the kind of to-be-adhered body, required adhesion characteristic, etc., when the total amount of A component and B component is 100 mass parts, it is preferable to set it as 0.1-5 mass parts. . When content is less than 0.1 mass part, adhesiveness may become inadequate in the bonding use with adherends, such as glass. On the other hand, when it exceeds 5 mass parts, there exists a possibility that pool residue may arise at the time of re-peeling. In order to acquire the said effect more reliably, it is preferable to make content of D component into 0.5-2 mass parts.

[2-5] A compound (component E) having a polymerizable unsaturated group other than component A and component B:

In addition to the said component, the composition of this invention may further contain the compound (component E) which has a polymerizable unsaturated group other than the said A component and the said B component as a structural component.

In addition, a "compound" is a concept containing the substance which has a polymerizable unsaturated bond widely. That is, as long as it has a polymerizable unsaturated bond, the chemical structure is not specifically limited, A monomer may be sufficient and an oligomer may be sufficient as it.

As a monomer which has a polymerizable unsaturated group, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i -Butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, i-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) (Meth) acrylic acid esters such as acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate and tetrahydrofurfuryl acrylate; Hydroxyl-containing (meth) acrylic acid esters, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl acrylate ; 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, etc. Polyfunctional acrylates; Vinyl carboxylates such as vinyl acetate and vinyl propionate; Aromatic vinyl, such as styrene and (alpha) -methylstyrene, etc. are mentioned.

However, the monomer which has a polymerizable unsaturated group might fall ultraviolet curability or yellow an adhesive composition under the conditions which reduced the quantity of a photoinitiator like this invention. Therefore, in the adhesive composition of this invention, it is preferable to use the polyfunctional oligomer which has two or more (meth) acryloyl-type functional groups per molecule as E component. By using a polyfunctional oligomer as a component, the effect that the crosslinking of an adhesive component is accelerated | stimulated is also exhibited.

Although there is no restriction | limiting in particular about a specific structure, The monomer which has polymerizable unsaturated bonds, such as (meth) acrylic acid ester, in polymers, such as polyester polyol, polypropylene glycol, an aliphatic polyester, and a bisphenol-type epoxy resin which becomes a basic skeleton, Combined urethane acrylates and the like. Although it also depends on the required performance of an adhesive, it is preferable to use the urethane acrylate and bisphenol-type epoxy acrylate of an aliphatic polyester frame | skeleton for the reason of compatibility with other components, and adjustment of the adhesive force after hardening.

As a polyfunctional acrylate, For example, Lighttech PSA805 (brand name, Kyoeisha Chemical Co., Ltd., basic skeleton: polyester polyol), NK oligo UA-340P (brand name, Shin-Nakamura Chemical Co., Ltd. make, basic skeleton: Polypropylene glycol), EB270 (brand name, Daicel Cytec Co., Ltd., basic skeleton: aliphatic polyester), CN-965 (brand name, Nippon Kayaku Co., Ltd., basic skeleton: aliphatic polyester), lipoxy VR-77 (brand name) , Showa Chemical Industries, Ltd., basic skeleton: bisphenol-based epoxy resin) and the like are commercially available. In addition, biscoat # 300 (a brand name, the product made by Osaka Yuki Chemical Co., Ltd., basic skeleton: pentaerythritol) etc. are marketed. However, according to the required performance, a compound having a desired structure may be appropriately synthesized and used.

Among these, a polyfunctional oligomer having an aliphatic polyester as a basic skeleton, having two or more (meth) acryloyl functional groups per molecule, and having a weight average molecular weight (Mw) in the range of 1,000 to 10,000 (for example, the EB270) Or the like) or a bifunctional oligomer having a bisphenol-based epoxy resin as a basic skeleton and having two or more of the above-mentioned (meth) acryloyl functional groups per molecule, and having a weight average molecular weight (Mw) in the range of 400 to 2000 (for example, , Epoxy VR-77, etc.) is preferable.

E component may be used individually by 1 type in the said compound, and may be used in combination of 2 or more type.

The content of the component E varies depending on the structure of the polymer of the component A, the type of adherend, the required adhesive properties, and the like. . When using the said polyfunctional oligomer especially as an E component, it is preferable to contain 0.5-20 mass parts of this polyfunctional oligomer. When content of a polyfunctional oligomer is less than 0.5 mass part, adjustment of adhesive strength may become difficult. On the other hand, when it exceeds 20 mass parts, there exists a tendency for adhesive force to fall remarkably. In order to acquire the said effect more reliably, it is preferable to make content of a polyfunctional oligomer into 0.5-15 mass parts, and it is more preferable to set it as 0.5-10 mass parts.

[2-6] UV absorbers (component F):

The composition of this invention may contain a ultraviolet absorber (F component) other than the said component. By blending the F component, it shields the ultraviolet rays having a strong chemical action and suppresses the oxidation (deterioration), or the deterioration (discoloration, fading, embrittlement, etc.) due to the oxidation or deterioration of substances present in the lower layer side than the adhesive layer or the decomposition of organic substances. The preferable effect to be exhibited (hereinafter, it may describe as "ultraviolet ray shielding property").

As an F component, it is preferable to contain the benzophenone type compound which has a (lambda) _maximum in the wavelength range of 350-400 nm. A "benzophenone type compound" is a compound which has a benzophenone skeleton shown by following formula (5). That is, as long as it has a benzophenone frame | skeleton represented by following formula (5) in a part of the structure, it is contained in the "benzophenone type compound" which is said to this invention in spite of the structure of another part. Therefore, among such various substances, an optimal substance can be appropriately selected according to the required performance (ultraviolet curability, color, etc.) as the resin composition and can be used as the F component.

However, in the composition of this invention, it is preferable that the absorption spectrum pattern of C component and F component does not match, in order to impart ultraviolet-ray shielding property, without impairing the action of a photoinitiator (C component). In the composition of this invention, it is preferable to use what has an absorption wavelength range in the range of 200-440 nm as C component, and what has an absorption wavelength range in the range of 200-415 nm as F component.

In other words, as component F, it is preferable to use that λ _max is in the λ _max with different wavelength ranges of the C component. For example, in the case of using those having a λ _max in the range of 240 to 250 nm as component C, of 280 to 300 nm as is preferred, and component C using an ultraviolet absorber having a λ _max in the range of 280 to 300 nm When using the thing which has a lambda _maximum in a range, it is preferable to use the ultraviolet absorber which has a lambda _maximum in the range of 310-330 nm, and when using the thing which has a lambda _maximum in the range of 380-410 nm as C component, it is 340. Preference is given to using ultraviolet absorbers having a λ _max in the range from 380 nm.

As a photoinitiator in which an absorption wavelength range exists in the range of 200-440 nm, For example, (alpha) -hydroxy acetophenone (brand name: Irgacure 184, the Ciba specialty chemicals company), (alpha)-amino acetophenone, a benzoin type compound, And acylphosphine oxide compounds (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and the like).

On the other hand, as an ultraviolet absorber whose absorption wavelength range is in the range of 200-415 nm (namely, the ultraviolet absorber which has a lambda _maximum in the wavelength range of 280-380 nm), for example, 2,2 ', 4,4'-tetra Hydroxybenzophenone (trade name: Dynesorb P-6, manufactured by Daiwa Kasei Co., Ltd.), 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (brand name: Sisov 107, manufactured by Cipro Kasei Co., Ltd.) And 2,4-dihydroxy benzophenone (trade name: Sisov 100, manufactured by Cipro Kasei).

Therefore, in the composition of this invention, it is preferable to use combining the said photoinitiator and the said ultraviolet absorber. Among them, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2,2'-dihydroxy-4,4'-dimethine are difficult to cause deterioration in color tone (yellowing) and the optical properties are good. Combinations of oxybenzophenones are preferred.

Although content of F component changes with kinds, quantities, etc. of C component, when making the total amount of A component and B component into 100 mass parts, it is preferable to set it as 0.1-15 mass parts. When content is less than 0.1 mass part, there exists a possibility that the ultraviolet blocking effect may become inadequate. On the other hand, when it exceeds 15 mass parts, an adhesive may not be cured or hardening may become inadequate. In order to acquire the said effect more reliably, it is preferable to make content of F component into 0.5-10 mass parts, and it is more preferable to use 1-5 mass parts.

[2-7] Solvents:

The composition of this invention may contain a solvent as a component. By containing a solvent, coating property can be improved and the problem that a nonuniformity is easy to produce at the time of coating can be prevented effectively.

The kind of solvent is not specifically limited, It can select suitably in consideration of miscibility with another component. For example, Aromatic solvents, such as toluene and xylene; Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and 2-methyl-5-hexanone; Ester solvents such as ethyl acetate, butyl acetate and ethyl lactate; Halogen solvents such as methyl chloride, dichloromethane and dichloroethane; Alcohol solvents such as ethanol and isopropanol; Glycol ether solvents such as ethylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol-n-propyl ether, propylene glycol methyl ether acetate, cellosolve acetate, methyl cellosolve, ethyl cellosolve, n-butyl cellosolve and cellosolves such as i-butyl cellosolve and n-propyl cellosolve.

Among the above solvents, it is preferable to use methyl ethyl ketone and ethyl acetate, and it is particularly preferable to use methyl ethyl ketone because it is easy to reduce the residual solvent concentration. These solvents may be used alone, or may be used in combination of two or more thereof.

Although content of a solvent changes also with the structure of the polymer of A component, the kind of to-be-adhered body, required adhesive characteristics, etc., it is preferable to contain a solvent so that solid content concentration of an adhesive composition may be in the range of 20-50 mass%. When solid content concentration of an adhesive composition is less than 20 mass%, adjustment of coating film thickness may become difficult. On the other hand, when solid content concentration exceeds 50 mass%, the viscosity of a composition may become high and coatability may fall.

In addition, content of a solvent can be adjusted based on the viscosity of a composition. Specifically, the amount of the solvent is adjusted so that the viscosity (25 ° C) of the composition is 100 to 5000 mPa · s, preferably 300 to 2000 mPa · s. However, a solvent is not limited to what is added at the time of the viscosity adjustment of such a composition. For example, when component A is polymerized by solution and it is made to use for manufacture of a composition, without distilling a solvent off, the solvent of a polymerization component of A component is also contained.

[2-8] Other additives:

In addition to the components described above, the composition of the present invention includes an anti-aging agent, an antifoaming agent, a leveling agent, an adhesion imparting agent, a tackifier, a light stabilizer, an antistatic agent, a surfactant, a storage stabilizer, a thermal polymerization inhibitor, a plasticizer, and a wettability improving agent. The additive which may be added to an adhesive composition etc. can also be mix | blended as needed. Content of these additives can be suitably determined in the range which does not impair the objective of the composition of this invention.

In addition, the composition of the present invention does not require the addition of a thermal crosslinking agent, unlike the conventional one. By not using a thermal crosslinking agent, the operation and curing of necessary two-liquid mixing are unnecessary in a two-component solvent-based adhesive (non-producing).

A "thermal crosslinking agent" means a substance which accelerates a crosslinking reaction by heating and expresses adhesive physical properties. However, in the composition of the present invention, the adhesive physical properties can be expressed without using these thermal crosslinking agents. Hereinafter, the thermal crosslinking agent used by a two-component solvent adhesive is mentioned for reference.

Bisphenol A epichlorohydrin type epoxy resin; Ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylol propane triglycidyl ether, sorbitol Epoxy-based compounds such as polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, and diglycerol polyglycidyl ether; Tetramethylol Methane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, N, N'-diphenylmethane-4,4'-bis (1-aziri Aziridine-based compounds such as dinecarboxyamide) and N, N'-hexamethylene-1,6-bis (1-aziridinecarboxyamide);

Melamine type compounds, such as hexamethoxy methyl melamine, hexaethoxy methyl melamine, hexapropoxy methyl melamine, hexabutoxy methyl melamine, hexapentyloxy methyl melamine, hexahexyloxy methyl melamine, and melamine resin; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4-diisocyanate, Isophorone diisocyanate, 1, 3-bis (isocyanate methyl) cyclohexane, tetramethyl xylylene diisocyanate, 1, 5- naphthalene diisocyanate, tolylene diisocyanate adduct of trimethylol propane, xylylene diisocyanate of trimethylol propane Isocyanates such as adducts, diphenylmethane-4,4-diisocyanate adducts of trimethylolpropane, isophorone diisocyanate adducts of trimethylolpropane, triphenylmethanetriisocyanate, methylenebis (4-phenylmethane) triisocyanate System compounds;

Aldehyde compounds such as glyoxal, malondialdehyde, succinic aldehyde, maledialdehyde, glutaraldehyde, formaldehyde, acetaldehyde and benzaldehyde; Amine compounds such as hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resins, and polyamides; And metal chelate compounds in which acetylacetone, acetoacetyl ester, and the like are coordinated with metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium.

[3] manufacturing method:

The composition of this invention can be obtained by mixing A component, B component, C component, D component, E component, F component, a solvent, and other additive as needed at a predetermined ratio.

[4] how to use:

The composition of this invention can be coated as it is. For example, after coating on the surface of a to-be-adhered body by conventionally well-known coating apparatuses, such as an applicator, an organic solvent is removed by drying, and then an adhesive coating film is irradiated by irradiating the ultraviolet-ray according to the kind of C component (photoinitiator). Can be formed.

Examples of the adherend to which the composition of the present invention can be applied include polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polysulfone, polymethyl methacrylate, polystyrene, polybutadiene, ABS resin, AS Thermoplastic resins such as resin, AES resin, polyimide resin, aliphatic polyamide resin (trade name: nylon), cellulose, nitrocellulose, triacetyl cellulose; Thermosetting resins such as phenol formaldehyde resin, cresol formaldehyde resin, melamine resin and urea resin; Inorganic materials, such as glass, a ceramic, and a metal, etc. are mentioned. In addition, the to-be-adhered body can also use the thing by which surface treatment was performed according to a use.

The adhesive force of the composition of this invention expresses by irradiation of an ultraviolet-ray. Although there is no restriction | limiting in particular about the wavelength of an ultraviolet-ray, It is preferable to irradiate the ultraviolet-ray whose wavelength is 200-400 nm. As a specific example of a light source, an ultra high pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a high power metal halide lamp, etc. are mentioned, for example. There is no restriction | limiting in particular also about ultraviolet irradiation conditions, Although it is not limited, It is preferable to set it as 100-600 mW / cm <^2> (20-150 mJ / cm <^2> ) in the case of a high pressure mercury lamp.

As adhesive strength, about 20-25 N / 25mm is preferable similarly to the conventional thermosetting type, but low adhesive force is calculated | required with the recent large-sized panelization. In that case, 20 N / 25 mm or less is preferable, and especially 15 N / 25 mm or less is especially preferable. This adhesive strength can be adjusted with the kind and quantity of E component other than content of the weight average molecular weight (Mw) of A component, glass transition temperature (Tg), and (meth) acryloyl group-alkoxysilyl group.

<Examples>

Hereinafter, the ultraviolet curable adhesive composition of this invention is demonstrated further more concretely using an Example. However, these Examples are only showing some embodiments of the present invention. Accordingly, the present invention should not be construed as being limited to these Examples.

[1] base polymer synthesis of component A:

First, the (meth) acrylic-type polymer used as A component base polymer was manufactured.

(Reference Example 1)

67 parts by mass of ethyl acrylate, 10 parts by mass of acrylonitrile, 23 parts by mass of 2-hydroxyethyl methacrylate and methyl ethyl ketone in a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer. 233 parts by mass were added and heated under a nitrogen stream to start heating reflux. Subsequently, 0.1 mass part of 2,2'- azobisisobutyronitrile (henceforth "AIBN") is added as a polymerization initiator, and it reacts at 90 degreeC for 5 hours, (meth) acrylic-type polymer (P-1) solution (The weight average molecular weight 19.8 million, the glass transition temperature of 0 degreeC, solid content concentration 30 mass%, and the viscosity 600 mPa * s / 25 degreeC) were obtained.

(Reference Example 2)

87 mass parts of ethyl acrylate, 3.5 mass parts of acrylonitrile, 9.5 mass parts of 2-hydroxyethyl acrylate, and methyl ethyl ketone 233 in a four-necked round bottom flask equipped with a reflux cooler, a stirrer, a nitrogen gas inlet, and a thermometer. A mass part was charged and heated under nitrogen stream to start heating reflux. Then, 0.03 mass part of AIBN is added as a polymerization initiator, and it is made to react at 80 degreeC for 6 hours, (meth) acrylic-type polymer (P-2) solution (weight average molecular weight 27.40,000, glass transition temperature -20 degreeC, solid content concentration 30 mass%). And viscosity 400 mPa · s / 25 ° C.) were obtained.

(Reference Example 3)

300 mass parts of water was put into the four neck round bottom flask provided with the reflux condenser, the stirrer, the nitrogen gas inlet, and the thermometer, and 0.7 mass parts of polyvinyl alcohol were stirred and dissolved as a dispersion stabilizer. In this solution, 13.4 parts by mass of AIBN was added as a monomer mixture consisting of 33.4 parts by mass of ethyl acrylate, 50 parts by mass of butyl acrylate, 3 parts by mass of methyl methacrylate, and 13.6 parts by mass of 2-hydroxyethyl methacrylate, and a polymerization initiator. To prepare a suspension. This suspension was heated under nitrogen stream to initiate heating reflux. After reacting at 80 DEG C for 4 hours, the reaction product was separated into solid and liquid, and then sufficiently washed with water, dried at 70 DEG C for 12 hours using a drier to obtain a (meth) acrylic polymer (P-3) as a solid resin (weight average molecular weight). 42.3 million, glass transition temperature -30 ° C).

(Reference Example 4)

300 mass parts of water was put into the four neck round bottom flask provided with the reflux condenser, the stirrer, the nitrogen gas inlet, and the thermometer, and 0.4 mass parts of polyvinyl alcohol were melt | dissolved as a dispersion stabilizer. 0.5 mass part of AIBN was collectively put into this melt | dissolution liquid as a monomer mixture which consists of 54.4 mass parts of ethyl acrylates, 29 mass parts of butyl acrylates, 3 mass parts of methyl methacrylates, and 13.6 mass parts of 2-hydroxyethyl acrylates, and a polymerization initiator. , Suspension was prepared. This suspension was heated under nitrogen stream to initiate heating reflux. After reacting at 80 ° C for 6 hours, the reaction product was solid-liquid separated, sufficiently washed with water, and then dried at 70 ° C for 12 hours using a drier to obtain a (meth) acrylic polymer (P-4) as a solid resin (weight average molecular weight). 60.3 million and glass transition temperature -30 degreeC).

(Reference Example 5)

Into a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer, 97 parts by mass of butyl acrylate, 3 parts by mass of 2-hydroxyethyl acrylate, and 233 parts by mass of methyl ethyl ketone were added. Heating under airflow initiates heating reflux. Then, 0.5 mass part of AIBN is added as a polymerization initiator, and it is made to react at 80 degreeC for 6 hours, (meth) acrylic-type polymer (P-5) solution (weight average molecular weight 79.80,000, glass transition temperature -55 degreeC, solid content concentration 30 mass%). And viscosity 4500 mPa · s / 25 ° C).

(Reference Example 6)

In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer, 70 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of acrylonitrile, 15 parts by mass of 2 hydroxyethyl methacrylate, and 400 mass parts of methyl ethyl ketones were thrown in, and it heated under nitrogen stream and started heating reflux. Then, 0.01 mass part of AIBN is added as a polymerization initiator, and it is made to react at 80 degreeC for 8 hours, (meth) acrylic-type polymer (P-6) solution (weight average molecular weight 152.30,000, glass transition temperature -55 degreeC, 20 mass% of solid content concentration). And the viscosity 8000 mPa * s (25 degreeC) were obtained.

(Reference Example 7)

A commercially available acrylic copolymer (brand name: Alphon UH2000, 100 mass% of solid content, the weight average molecular weight 1.1 million, glass transition temperature -55 degreeC, the product made from Toagosei Co., Ltd.) was made into the polymer (P-7).

(Reference Example 8)

100 parts by mass of toluene was added to a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer, followed by 97.5 parts by mass of 2-ethylhexyl acrylate, 1.5 parts by mass of 2-hydroxyethyl acrylate, A (meth) acrylic polymer (P-8) solution was obtained by reacting a mixed solution of 1 part by mass of acrylic acid and 2 parts by mass of AIBN over 2 hours under a stream of nitrogen at 8 ° C. for 8 hours (weight average molecular weight 48.60,000, glass transition Temperature -83 ° C, solid content concentration 50% by mass, viscosity 7400 mpas / 25 ° C).

(Reference Example 9)

5 mass parts of acrylic acid, 95 mass parts of butyl acrylate and 80 mass parts of ethyl acetate, 40 mass parts of acetone, AIBN 0.03 mass as a polymerization initiator in a four-necked round bottom flask equipped with a reflux cooler, a stirrer, a nitrogen gas inlet, and a thermometer. Was added, and the mixture was diluted with ethyl acetate at a reflux temperature of nitrogen for 3 hours, and then diluted with ethyl acetate (meth) acrylic polymer (P-9) solution (weight average molecular weight 183.60,000, glass transition temperature -50 ° C, solid content concentration 16). Mass%, viscosity 9000 mPa · s / 25 ° C).

[2] Synthesis of Crosslinkable (meth) acrylic Polymer (Component A):

Next, a reactive sensitizer was introduced to the base polymer to obtain a crosslinkable (meth) acrylic polymer (A-1).

(Reference Example 10)

0.05 part by mass of dibutyltin laurate and 0.3 part by mass of the (meth) acrylic polymer (P-1) solution synthesized in Reference Example 1 with respect to 100 parts by mass (in terms of solids) of the (meth) acrylic polymer (P-1). -Methacryloyloxyethyl isocyanate (brand name: Carens MOI, Showa Denko Co., Ltd.) was put in, and it was made to react at 50 degreeC for 8 hours. The completion | finish of reaction was confirmed by the loss | disappearance of the isocyanate group by the appropriate analysis of the reaction liquid. Thereby, a (meth) acryloyl group is introduce | transduced into an acryl-type polymer (P-1), and it is a crosslinkable (meth) acrylic-type polymer (A-1) solution (weight average molecular weight 19.9 million, glass transition temperature 0 degreeC, solid content concentration 30). Mass%, viscosity 600 mPa * s / 25 ° C).

(Reference Examples 11 to 23)

Crosslinkable (meth) acrylic polymers (A-2) to (A-10) in the same manner as in Reference Example 8, except that the type and amount of the (meth) acrylic compound having an isocyanate group and the base polymer were changed. , (A-12) to (A-15) were obtained. Table 1, Table 3, Table 5 and Table 7 shows the charge ratio thereof.

(Reference Example 24)

The (meth) acrylic polymer (P-3) synthesized in Reference Example 3 was dissolved in 233 parts by mass of methyl ethyl ketone to obtain a (meth) acrylic polymer solution (solid content concentration of 30% by mass). 0.05 parts by mass of dibutyltin laurate, 0.25 parts by mass of 2-acryloyloxyethyl isocyanate (trade name: Carens AOI, manufactured by Showa Denko) and alkoxysilane based on 100 parts by mass of the (meth) acrylic polymer (in terms of solid content). 0.1 mass part of system compounds (3-isocyanate propyl triethoxysilane, brand name: KBE-9007, the Shin-Etsu Chemical Co., Ltd. product) were thrown in, and it was made to react at 50 degreeC for 8 hours. The reaction was complete | finished when the loss | disappearance of the isocyanate group was confirmed by the appropriate analysis of the reaction liquid, and the crosslinkable (meth) acrylic-type polymer (A-11) solution was obtained (weight average molecular weight 42.5 million, glass transition temperature -30 degreeC). , Viscosity 500 mPa · s / 25 ° C.).

(Reference Example 25)

To the (meth) acrylic polymer (P-8) solution synthesized in Reference Example 8, 2 parts by mass of 2-methacryloyloxyethyl isocyanate (Showa Denko Co., Ltd. Carens MOI), 0.04 parts by mass of hydroquinone and dibutyltin 0.04 mass part of laurates were added, and the modification reaction was performed for 8 hours at the same temperature. Subsequently, toluene was distilled off and the crosslinkable (meth) acrylic-type polymer (A-16) was obtained by making residual solvent 1% or less (weight average molecular weight 49.3 million, glass transition temperature -83 degreeC).

(Reference Example 26)

50 mass parts of ethyl acetate / 50 mass parts of toluene with respect to 100 mass parts (solid content conversion) of the (meth) acrylic-type polymer (P-9) in the (meth) acrylic-type polymer (P-9) solution synthesize | combined by the reference example 9, 0.08 mass part of dibutyltin dilaurylates and 5.4 mass part of 2-methacryloyloxyethyl isocyanate were thrown in, and it was made to react at 65 degreeC for 8 hours. Finally, the reaction solution was diluted with toluene to obtain a crosslinkable (meth) acrylic polymer (A-17) solution (weight average molecular weight 185.30,000, glass transition temperature -50 ° C, solid content concentration 13 mass%, viscosity 9500 mPas / s). 25 ° C.).

In addition, the quality of A component was evaluated with the following method.

[Weight Average Molecular Weight]

The weight average molecular weight of polystyrene conversion of the polymer was measured by GPC method.

[Glass transition temperature]

The glass transition temperature of the polymer was measured according to JIS K7121 (transition temperature measuring method of plastic).

[Methacryloyl Group Content, Triethoxysilyl Group Content]

The methacryloyl group content and triethoxysilyl group content of the polymer were quantified by an acid base titration method. Specifically, the obtained polymer is mixed with di-butylamine (DBA), the unreacted isocyanate group of the (meth) acrylic compound or the alkoxysilane compound is reacted with DBA to quantify the amount of DBA consumed by reverse titration with hydrochloric acid. It was.

[Production of Ultraviolet Curable Adhesive Composition]

(Example 1)

7 mass parts of acrylic acid (component B-1) with respect to 93 mass parts of solid content in the crosslinkable (meth) acrylic-type polymer (component A-1) solution (solid content 30 mass%) of the reference example 10, 2,4,6-trimethyl Benzoyl-diphenylphosphine oxide (C-1 component, brand name: Lucirin TPO, BASF Corporation) 0.5 mass part, 3-glycidoxy propyl trimethoxysilane (component D-1, brand name: KBM-403, shin 1 mass part of Saga Chemical Co., Ltd. product) was mixed, and the ultraviolet curable adhesive composition was manufactured.

(Examples 2 to 27, Comparative Examples 1 to 23)

Except having changed the kind and quantity of each component into the composition shown in Table 1-12 using A component (A-1-A-15 component) synthesize | combined in the reference examples 10-26, In the same manner, an ultraviolet curable pressure-sensitive adhesive composition was prepared. In addition, the following were used as each component.

<Component B>

B-1: acrylic acid (manufactured by Osaka Yuki Kogyo Co., Ltd.)

B-2: acrylic acid dimer (brand name: bipolymer β-CEA-J, manufactured by Rhodia Lysa)

<C component>

C-1: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (brand name: Lucirin TPO, manufactured by BASF Corporation)

C-2: of oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester Mixture (trade name: Irgacure 754, manufactured by Ciba Specialty Chemicals)

C-3: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (trade name: Irgacure 907, manufactured by Ciba Specialty Chemicals, Inc.)

C-4: 2,2-dimethoxy-1,2-diphenylethan-1-one (brand name: Irgacure 651, the Ciba specialty chemicals company make)

C-5: 1-hydroxy cyclohexyl phenyl- ketone (brand name: Irgacure 184, the Ciba specialty chemicals company make)

<D component>

D-1: 3-glycidoxypropyl trimethoxysilane (brand name: KBM-403, Shin-Etsu Chemical Co., Ltd. make)

D-2: 3-glycidoxy propyl triethoxysilane (brand name: KBE-403, Shin-Etsu Chemical Co., Ltd. make)

D-3: N-2 (aminoethyl) 3-aminopropyl trimethoxysilane (brand name: KBM-603, Shin-Etsu Chemical Co., Ltd. make)

D-4: 3-mercaptopropyl trimethoxysilane (brand name: KBM-803, Shin-Etsu Chemical Co., Ltd. make)

<E component>

E-1: aliphatic polyester backbone urethane acrylate (trade name: EB270, manufactured by Daicel Cytec Co., Ltd.)

E-2: Bisphenol-type epoxy resin skeletal urethane acrylate (brand name: Repoxy VR-77, the Showa Kobunshi company make)

E-3: 2-ethylhexyl acrylate

E-4: 1, 6-hexanediol diacrylate (brand name: NK ester A-HD, Shin-Nakamura Chemical Co., Ltd. make)

<F component>

F-1: 2,2 ', 4,4'-tetrahydroxy benzophenone (brand name: Dynesorb P-6, the Daiwa Kasei Co., Ltd. make)

<Heat cross-linking>

Polyisocyanate (brand name: Colonate L, Nippon Polyurethane Co., Ltd. make)

<Solvent>

Methyl ethyl ketone (manufactured by Kishida Chemical Industries, Ltd.)

Toluene (made by Kishida Chemical Industries, Ltd.)

Ethyl acetate (manufactured by Kishida Chemical Industries, Ltd.)

Acetone (manufactured by Kishida Chemical Industries, Ltd.)

In addition, the quality of the ultraviolet curable adhesive composition was evaluated by the following method.

[Handling (property like thread of liquid)]

The composition of evaluation was made into the coating liquid of 30 mass% of solid content concentration, the coating liquid was affixed on the glass rod, and the visual observation evaluated the state when a coating liquid falls from the glass rod. When the coating liquid falls from the glass rod, the glass rod and the coating liquid are completely separated, and when the liquid is dropped into the droplet state, "◎" (good), the glass rod and the coating liquid are not completely separated, and the seal is turned off. When it fell, it evaluated by "x" (defect).

[Corporate Potency]

The composition to be evaluated is used as a coating liquid having a solid content concentration of 30%, and the coating liquid is applied to a silicone treated surface of a 38 μm-thick PET film (peel film) subjected to silicone treatment on one side by an applicator, and at 80 ° C. After drying for 2 minutes, ultraviolet rays were irradiated under the conditions of 500 mW / cm ² and 80 mJ / cm ² , and the coating film was UV cured to form an adhesive layer. Thereafter, the pressure-sensitive adhesive layer of the release film is bonded to the PET film (100 μm in thickness, 91% of total light transmittance, 0.3 ha. Or less, referred to as “substrate film”) serving as a base material, to the surface of the base film. An adhesive layer having a thickness of 15 mm was formed. In addition, the said ultraviolet-ray irradiation was performed by the high pressure mercury lamp. Ultraviolet light with a wavelength of 200 to 400 nm is irradiated with a high pressure mercury lamp.

Evaluation of coating property confirmed the presence or absence of coating root when coating liquid was apply | coated to the surface of the said release film by the applicator. Specifically, the gap width of the applicator was adjusted so that the thickness of the coating film was 15 µm, and the coating was performed at 20 m / min. The number of coating roots generated at that time was evaluated by the number of occurrences per coating width of 15 cm. In the case of zero coating roots, "◎" (very good) was evaluated as "(circle)" in one case and "x" (poor) in two or more cases.

[Gel powder]:

The gel powder of the composition to be evaluated was weighed by the Soxhlet extraction method. Specifically, Soxhlet extraction using tetrahydrofuran as a solvent was performed for 8 hours, and the mass% of the insoluble content remaining without extraction was expressed as a gel powder (mass%). When the gel content was 60 mass% or more, "◎" (very good), 55 mass% or more, and less than 60 mass% were judged as "(circle)" (good), and less than 55 mass% as "x" (poor). When the gel content is 55% by mass or more, the pressure-sensitive adhesive is not pushed out when the pressure-sensitive adhesive film is wound, and no pressed trace by protective films such as an embossing film is generated.

[Production of Adhesive Film]

The solution (solid content concentration 30%) of the ultraviolet curable adhesive composition of an Example and a comparative example was apply | coated to the silicone process surface of the said peeling film, it dried at 80 degreeC for 2 minutes, and irradiated with ultraviolet-ray by a high pressure mercury lamp (UV irradiation condition: 500 mW / cm ² , 80 mJ / cm ² ) and a pressure-sensitive adhesive layer having a thickness of 15 μm were formed. Next, the adhesive layer of the said release film was bonded to the said base film, and the base film (adhesive film) in which the adhesive layer was formed was obtained by peeling the said release film.

However, about the comparative example 21-1, it apply | coated to the siliconization surface of the said peeling film as it is, without diluting the ultraviolet curable adhesive composition (solid content concentration 100%) of the comparative example 21-1 with a solvent, and bonding the said base film. It was made into a laminate state, the pressure-sensitive adhesive layer was adjusted to a thickness of 20 μm, and ultraviolet rays were irradiated with a high pressure mercury lamp (UV irradiation conditions: 500 mW / cm ² and 80 mJ / cm ² ). Then, the base film (adhesive film) in which the adhesive layer was formed was obtained by peeling the said peeling film.

In addition, about the comparative example 21-2, it applies to the silicone process surface of the said peeling film as it is, without diluting the ultraviolet curable adhesive composition (solid content concentration 100%) of the comparative example 21-2 with a solvent, and irradiating an ultraviolet-ray with a high pressure mercury lamp. Irradiation (UV irradiation conditions: 500 mW / cm ² , 80 mJ / cm ² ) to form a pressure-sensitive adhesive layer of 20 μm thick. Next, the adhesive layer of the said release film was bonded to the said base film, and the base film (adhesive film) in which the adhesive layer was formed was obtained by peeling the said release film.

In addition, about the comparative example 22-1, the solution (solid content concentration 30%) of the ultraviolet curable adhesive composition of the comparative example 22-1 was apply | coated to the silicone process surface of the said peeling film, it heated at 90 degreeC for 3 minutes, and 20 micrometers in thickness. Pressure-sensitive adhesive layer was formed. Subsequently, after the adhesive layer of the said peeling film was bonded to the said base film to make a laminated state, ultraviolet irradiation was performed with the high pressure mercury lamp. It cured under 40 degreeC and dry conditions for 4 days, the said peeling film was peeled off, and the base film (adhesive film) in which the adhesive layer was formed was obtained.

Moreover, about Comparative Examples 22-2 and 22-3, after irradiating the adhesive layer of the said peeling film to ultraviolet-ray, it is bonded to the said base film, and the base film in which the adhesive layer was formed by peeling the said peeling film (adhesive film) Got. In addition, the curing was not performed.

In addition, about the comparative example 23-1, the solution (solid content concentration 30%) of the thermosetting adhesive composition of the comparative example 23-1 was apply | coated to the siliconization surface of the said peeling film, it heated at 90 degreeC for 3 minutes, and 20 micrometers in thickness. Pressure-sensitive adhesive layer was formed. Next, after bonding the adhesive layer of the said peeling film to the said base film, the said peeling film was peeled off without hardening, and the base film (adhesive film) in which the adhesive layer was formed was obtained. This adhesive film was bonded to alkali glass. About Comparative Example 23-2, an adhesive film was obtained in the same manner as in Comparative Example 23-1, except that curing was performed for 4 days under 40 ° C and dry conditions.

[Adhesiveness]

Except for Comparative Examples 21-1 to 21-2, 22-1 to 22-3, and 23-1 to 23-2, a coating film having a thickness of 15 μm was formed on the surface of the base film in the same manner as in the evaluation of the coating property. (Adhesive layer) was formed.

Thereafter, with no curing (specifically, after 2 hours of coating film formation), the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. After this laminated body was formed, the adhesive force (initial adhesive force) of the said adhesive film and alkali glass in the time point which passed 1 hour was measured by the 180 degree peel test as described in JISZ0237 (adhesive tape and adhesive sheet test method). In addition, the pool residue of the alkali glass surface at this time was visually evaluated.

"◎" (very good) that initial adhesive force is more than 5N / 25mm, 15N / 25mm or less, 3N / 25mm or more and less than 5N / 25mm and more than 15N / 25mm 20N / 25mm "(Circle)" (good), more than 20N / 25mm to be less than 30N / 25mm to be less than "△" (slightly defective), less than 3N / 25mm and less than 30N / 25mm Poor). Regarding the pool residue, "(circle)" (good) and the case where the pool residue was confirmed by the naked eye were made into "x" (bad) when the pool residue was not visually recognized at all.

[Heat resistance]

In the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. This laminated body was exposed to 1000 hours on condition of high temperature (80 degreeC), and the adhesive force of the said adhesive film and alkali glass after that was measured by the 180 degree peel test as described in JISZ0237 (adhesive tape and adhesive sheet test method). . In addition, the pool residue of the alkali glass surface at this time was visually evaluated.

Adhesive force T ₁ and the post-exposed under normal conditions in the evaluation of the adhesive, the adhesive retention rate R ₁ is calculated to from the adhesion T ₂ by the equation (2) post-exposed under a high temperature condition, "the case in the range of 100 to 200% (Circle) (good), the case below 100%, and the case above 200% were evaluated by "x" (poor). In addition, about pool residue, the case where pool residue was not visually recognized was evaluated as "(◎)" (good), and the case where pool residue was confirmed visually was "x" (defect).

[Equation 2]

R ₁ = (T ₂ / T ₁ ) × 100

(However, T ₁ : initial adhesive strength in normal state (N / 25 mm), T ₂ : adhesive strength after exposure under high temperature conditions (N / 25 mm), R ₁ : adhesion retention rate (%))

[Moisture heat resistance]

In the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. This laminated body was exposed to high temperature and high humidity (temperature: 60 degreeC, humidity: 90%) for 1000 hours, and the adhesive force of the said adhesive film and alkali glass after that was JIS Z0237 (adhesive tape and adhesive sheet test method). It was measured by the 180 ° peel test described in.

Adhesive force T ₁ and the post-exposed under normal conditions in the evaluation of the adhesiveness, high temperature and when the adhesive holding ratio R ₂ is in the range of 100 to 200% calculated by the following equation (3) from the adhesive force T ₃ after exposed under high humidity conditions Was evaluated as "x" (good), less than 100% and more than 200% as "x" (defect). In addition, about pool residue, the case where pool residue was not visually recognized was evaluated as "(◎)" (good), and the case where pool residue was confirmed visually was "x" (defect).

&Quot; (3) &quot;

R ₂ = (T ₃ / T ₁ ) × 100

(However, T ₁ : initial adhesive strength in normal state (N / 25 mm), T ₃ : adhesive strength after exposure under high temperature and high humidity conditions (N / 25 mm), T ₂ (N / 25 mm), R ₂ : Adhesion retention rate (%)

[Color difference]

In the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. The color difference (b *) of this laminated body at 25 degreeC was measured with the color difference meter (brand name: Spectrophotometer SQ-2000, the Nippon Denshoku Kogyo Co., Ltd.) (Hereinafter, it may describe as "initial-color difference".) ). An initial color difference (b *) of 0.3 or less was evaluated as "(circle)" (very good), more than 0.3 and "0.5" (good), and more than 0.5 as "x" (bad). However, about the composition of Example 27 which mix | blended the ultraviolet absorber, since the ultraviolet absorber itself is yellow and the color difference index differs, it is "◎" that the initial color difference (b *) is 1 or less, " X ".

In addition, the color difference was measured by the same method also about the laminated body after a heat resistance test, and the laminated body after a heat-and-moisture resistance test (Hereinafter, it may describe as "durable color difference."). About endurance color difference (b *), the difference with an initial color difference is less than 0.1, "◎" (very good), 0.1 or more and 0.2 or less evaluate that "(circle)" (good) and the thing exceeding 0.2 as "x" (poor). It was.

[Total Light Transmittance]

In the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. The total light transmittance at 25 degrees C of this laminated body was measured by the turbidimeter (brand name: haze meter HM-150, Murakami Shikisai Kijutsu Co., Ltd. make) (hereinafter, it may describe as "initial total light transmittance"). has exist). The initial total light transmittance of 90% or more was evaluated as "(circle)" (very good) and 88% or more as "(circle)" (good) and less than 88% as "x" (bad).

In addition, the total light transmittance was measured by the same method also about the laminated body after a heat resistance test, and the laminated body after a wet-heat resistance test (it may describe as "durable total light transmittance" hereafter). About the durable total light transmittance, it is "◎" (very good) that the difference with initial stage total light transmittance is less than 1%, "○" (good) and that exceeding 2 "X" (defect) Was evaluated.

[Haze]

In the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to an alkali glass (general hard glass) to form a laminate. The haze at 25 degrees C of this laminated body was measured with the turbidity meter (brand name: haze meter HM-150, Murakami Shikisai Kijutsu Co., Ltd. make). (Hereinafter, it may describe as "initial haze."). About initial stage haze, what was 1.0 or less was evaluated as "(circle)" (very good), the thing exceeding 1.0 and the thing below 2.0 as "(circle)" (good), and exceeding 2.0 as "x" (poor).

In addition, the haze was measured by the same method also about the laminated body after a heat resistance test, and the laminated body after a heat-and-moisture resistance test (Hereinafter, it may describe as "durable haze."). About the durability haze, the thing with "(circle)" (good) and the thing exceeding 0.3 and "0.3" (good) and the thing exceeding 0.3 were evaluated as "x" (defect) that the difference with initial stage haze was less than 0.1.

[UV protection]

About the composition obtained in Example 27, UV blocking property was evaluated by the following method. First, in the same manner as in the above evaluation of the adhesiveness, the base film (adhesive film) on which the pressure-sensitive adhesive layer was formed was bonded to alkali glass (general hard glass) to form a laminate. Thereafter, a spectral spectrum at a wavelength of 300 to 800 nm was measured using an ultraviolet visible spectrophotometer (trade name: U-best V-570, manufactured by Nippon Bunker Co., Ltd.), and the ultraviolet ray transmittance (`` UV Barrier properties ”). The case where the ultraviolet ray transmittance of wavelength 380 nm or less is 5% or less was evaluated as "(circle)" (good) and the case exceeding 5% as "x" (poor).

(evaluation)

The pressure-sensitive adhesive compositions of Examples 1 to 27 do not perform laminate protection under air, but also exhibit adhesiveness without curing, and are excellent in handling, coating properties, gel powder, adhesive properties, optical properties, and paste residue (re-peelability). Indicated. The pressure-sensitive adhesive composition of Example 27 also showed good UV blocking properties.

Among these pressure-sensitive adhesive compositions, the weight average molecular weight of component A is 400,000 to 600,000, the content of component A is 90 to 99.5 parts by mass, the amount of component B is 0.5 to 10 parts by mass, and the amount of component C is 0.05 to 0.5 parts by mass. The pressure-sensitive adhesive compositions of Examples 3, 4, 6, 8, 9, and 10 satisfying the range have good results in curing properties under air, initial adhesive strength of about 15 N / 25 mm, adhesive strength under heat and moisture resistant heat conditions, and optical properties. Indicated.

In addition, in the adhesive composition containing E component, the weight average molecular weight of A component is 400,000-60,000, content of A component is 90-99.5 mass parts, and the amount of (meth) acryloyl functional groups is 0.6-10.6 mmol / 100 g, the amount of the component B is 0.5 to 10 parts by mass, and Examples 12, 13, 14, 16, 17, 23, 25, and 26 using the E-1 component and / or the E-2 component as the E component are 5 to The initial adhesive force of 15 N / 25 mm was shown, and the favorable result was shown to the adhesive force and optical characteristic under heat-resistant and moisture-resistant heat conditions.

In particular, the pressure-sensitive adhesive compositions of Examples 4, 8, 13, 14, 16, 21, 23, and 25 exhibit excellent adhesive properties including low adhesion of about 5 to 15 N / 25 mm, optical properties, gel powder, Very good results were obtained throughout evaluation items such as coatability.

By addition of component B, it becomes possible to use an acylphosphine oxide type initiator under air, and the usage-amount can be reduced. The pressure-sensitive adhesive composition of Examples 3 to 5, 7 to 10, 12 to 14, 16 to 18, 20 to 21, 23 to 27 using an acylphosphine oxide-based initiator and reducing the amount of use thereof has optical properties, in particular, color difference Not only can the initial color difference be suppressed to a low value, but also the color difference value after the endurance has shown a very good result that it shows an equivalent value with little change from the initial value.

On the other hand, the pressure-sensitive adhesive composition of Comparative Example 1 exhibited a poor coating property because the molecular weight of the A component was too large and the viscosity and viscosity were high. In Comparative Example 2, since the molecular weight of the component A was too small, the gel content was low (that is, the film strength after UV curing was poor), and the pool residue (repeelability) was poor.

Since the content of the B component or the C component is out of the range of the present invention, the adhesive compositions of Comparative Examples 3 to 6 exhibited poor adhesive physical properties and poor optical properties when cured under air. In addition, since the adhesive composition of Comparative Examples 7-10 used the photoinitiator which is not an acylphosphine oxide type as a C component, the optical characteristic showed the poor result.

In the pressure-sensitive adhesive compositions of Comparative Examples 11 to 14, the content of the (meth) acryloyl functional group of the A component was out of the range of the present invention, resulting in poor adhesive properties, optical properties, and gel powder (film strength).

Since the pressure-sensitive adhesive composition of Comparative Examples 15 to 17 is out of the range of the present invention, the pressure-sensitive adhesive properties showed poor results. Moreover, when the A component and D component which have a (meth) acryloyl-type functional group are not used together from the comparison of the adhesive composition of Comparative Examples 13-14, the adhesive holding force on the heat-and-moisture-resistant conditions showed the bad result.

Since the adhesive composition of Comparative Examples 18-19 is a silane coupling agent which D component does not have an epoxy type functional group, the adhesive physical property showed the bad result. In addition, the pressure-sensitive adhesive composition of Comparative Example 20 exhibited poor adhesive physical properties because the content of the E component was out of the range of the present invention.

In the pressure-sensitive adhesive compositions of Comparative Examples 21-1 and 21-2, an acrylate ester monomer was used as the E component, and the amount thereof was also out of the range of the present invention, resulting in poor coatability and optical properties.

Since the pressure-sensitive adhesive composition of Comparative Example 22-2 was used as a curing agent using a heat crosslinking agent, the adhesive physical properties showed poor results. Since the adhesive composition of the comparative example 22-1 used the heat crosslinking agent and hardened | cured under laminate protection, it was comparatively favorable about adhesive physical property and optical characteristics. However, since the weight average molecular weight of A component was large, the result of poor handling and coatability was shown. In addition, similarly to the pressure-sensitive adhesive composition of Comparative Example 22-3, in the same composition as Comparative Examples 22-1 and 22-2, and when the thermal crosslinking agent was not blended, the adhesive physical properties and the optical properties were poor.

In addition, although the adhesive composition of Comparative Example 23-2 used the thermal crosslinking agent and favorable adhesive physical property was obtained, curing for 40 days and 4 days was needed. That is, when the curing was not performed, as shown in Comparative Example 23-1, both the adhesive properties and the optical properties showed poor results.

The ultraviolet curable pressure-sensitive adhesive composition of the present invention can be suitably used in applications such as electronic materials and optical materials, in particular in the application of functional films such as antireflective films to surfaces such as plasma displays (PDPs) and liquid crystal displays (LCDs). Can be.

Claims (7)

At least one of (meth) acrylic polymer (component A), carboxylic acid having a polymerizable unsaturated group and an oligomer thereof (component B), a photopolymerization initiator (component C), a silane coupling agent (component D), and the component A and the above It includes the compound (component E) which has a polymerizable unsaturated group other than B component as a structural component,
The said A component has a (meth) acryloyl-type functional group which contains the repeating unit derived from a (meth) acrylic-type monomer in a main chain, and contains a (meth) acryloyl skeleton in a side chain, and said (meth) acryl per 100g of polymers It is a crosslinkable (meth) acrylic-type polymer which contains 0.5-20 mmol of royl-type functional groups, glass transition temperature (Tg) is -55 degreeC-0 degreeC, and a weight average molecular weight (Mw) exists in the range of 200,000-1 million,
The C component is an acylphosphine oxide photopolymerization initiator,
The said D component is a silane coupling agent which has an epoxy-type functional group,
When the total amount of the A component and the B component is 100 parts by mass, 80 to 99.5 parts by mass of the A component, 0.5 to 20 parts by mass of the B component, 0.05 to 3 parts by mass of the C component, and D component UV curable pressure-sensitive adhesive composition containing 0.1 to 5 parts by mass, and 0 to 20 parts by mass of the E component. The ultraviolet light according to claim 1, wherein the component A has an alkoxysilyl functional group containing an alkoxysilyl skeleton in the side chain and is a crosslinkable (meth) acrylic polymer containing 0.04 to 4 mmol of the alkoxysilyl functional group per 100 g of the polymer. Curable adhesive composition. The said E component is a polyfunctional oligomer of Claim 1 or 2 which has 2 or more of the said (meth) acryloyl-type functional groups per molecule,
The ultraviolet curable adhesive composition containing 0.5-20 mass parts of said E components, when the total amount of the said A component and the said B component is 100 mass parts. The ultraviolet curable adhesive composition of Claim 3 whose said E component is a polyfunctional oligomer whose aliphatic polyester is a basic skeleton, and whose weight average molecular weight (Mw) exists in the range of 1000-10,000. The ultraviolet curable adhesive composition of Claim 3 whose said E component is a polyfunctional oligomer which has a bisphenol-type epoxy resin as a basic skeleton, and has a weight average molecular weight (Mw) in the range of 400-2000. The ultraviolet curable pressure-sensitive adhesive composition according to claim 1 or 2, wherein the ultraviolet curable pressure-sensitive adhesive composition contains a benzophenone-based compound having a lambda _maximum in a wavelength region of 350 to 400 nm as an ultraviolet absorber (F component). The ultraviolet curable pressure-sensitive adhesive composition according to claim 1 or 2, wherein the C component is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.