KR101849781B1 - Adhesive composition - Google Patents

Abstract

(assignment)
There is provided an adhesive composition capable of easily peeling a cured product after application and curing from an object to be adhered.
(Solution)
The adhesive composition according to the present invention contains at least one (meth) acrylic monomer and a photopolymerization initiator of the following (1) or (2).
(1) a bifunctional (meth) acryl monomer having two (meth) acryloyl groups and having a polyalkylene oxide chain between two (meth) acryloyl groups and having two (meth) acryloyl groups The shortest number of atoms to be connected is 13 or more.
(2) an n-functional (meth) acryl monomer having n (meth) acryloyl groups (n is an integer of 3 or more), and has a polyalkylene oxide chain between any two (meth) acryloyl groups And the number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more.

Description

ADHESIVE COMPOSITION [0001]

The present invention relates to an adhesive composition which can be cured by ultraviolet irradiation or the like.

BACKGROUND ART In a liquid crystal display (LCD) such as a cellular phone, a transparent protective plate is formed on the front surface of an LCD module for the purpose of protecting it from external force. In recent years, a liquid crystal display with a touch panel has attracted attention. In this case, a touch panel is formed on the back surface of the protection plate.

Conventionally, for example, when a protective plate is bonded to an LCD module, it has been common practice to affix an adhesive film only to the peripheral edge portion of the coplanar surface of the protective plate, followed by bonding the protective plate to the LCD module. However, in such a bonding method, there is a problem that visibility is deteriorated due to a difference in refractive index between the protective plate and air, because an air layer is present in a central portion where no adhesive film exists. Therefore, in order to solve such a problem, an adhesive film is attached to the entire surface of the protective plate.

Further, a method of using a liquid adhesive composition which can be cured by ultraviolet irradiation or the like has been proposed (see Patent Documents 1 and 2, etc.) in order to lower the cost than the method of using an adhesive film. In the case of adhering a protective plate to the LCD module by this method, the adhesive composition is applied to the entire surface of the protective plate, then the protective plate is bonded to the LCD module, and the adhesive composition is cured by ultraviolet irradiation or the like.

Normally, after the protection plate is bonded to the LCD module in this way, inspection is performed on the bonding state. Then, when foreign matter or air enters the coplanar surface, or the position of the fusion is misaligned to cause a positional deviation, and when it is judged that the fusion is bad, the protective plate is separated from the LCD module, and the protective plate is again bonded.

Japanese Patent Application Laid-Open No. 63-281101 Japanese Laid-Open Patent Publication No. 2009-001655

However, in the case of using an adhesive composition in a sticking portion of a protective plate, there is a problem that a cured product of the adhesive composition remains on the separated protective plate, and peeling of the cured product is difficult. Therefore, the shield plate was discarded because it can not be reused. Here, if the cured product of the adhesive composition can be easily peeled off from the object to be adhered such as a protective plate, it can be considered that the object to be adhered such as a protective plate can be reused. Such an adhesive composition, .

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional circumstances, and an object of the present invention is to provide an adhesive composition capable of easily separating a cured product after application and curing from an object to be adhered.

The present inventors have conducted intensive studies to solve the above problems. As a result, it has been found that the above problems can be solved by containing a specific (meth) acrylic monomer in the adhesive composition, and the present invention has been accomplished.

That is, the adhesive composition according to the present invention contains at least one (meth) acrylic monomer of the following (1) or (2) and a photopolymerization initiator.

(1) a bifunctional (meth) acryl monomer having two (meth) acryloyl groups and having a polyalkylene oxide chain between two (meth) acryloyl groups and having two (meth) acryloyl groups The shortest number of atoms to be connected is 13 or more.

(2) an n-functional (meth) acryl monomer having n (meth) acryloyl groups (n is an integer of 3 or more), and has a polyalkylene oxide chain between any two (meth) acryloyl groups And the number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more.

In the present specification, the "number of the shortest atoms connecting two (meth) acryloyl groups" means the number of the (meth) acryloyl groups (CH ₂ ═C (CH ₃ ) -C (═O) - or CH ₂ = CH-C (= O) -) means the number of atoms to be connected when connected in the shortest path so that the number of atoms is minimized.

According to the present invention, it is possible to provide an adhesive composition capable of easily separating a cured product after application and curing from an object to be adhered.

This adhesive composition can be applied not only to bonding a protective plate to an LCD module in the liquid crystal display field but also to an adhesive tape used for back grinding a substrate such as a wafer in the semiconductor field (see, for example, JP-A-2005-174963 ) Or the like, which is easy to peel off.

&Quot; Adhesive composition &

The adhesive composition according to the present invention contains a specific (meth) acrylic monomer and a photopolymerization initiator. Hereinafter, each component contained in the adhesive composition will be described in detail.

≪ Specific (meth) acrylic monomer >

The adhesive composition according to the present invention contains at least one (meth) acrylic monomer selected from the following first (meth) acrylic monomers or second (meth) acrylic monomers described below.

First, the first (meth) acrylic monomer is a bifunctional (meth) acrylic monomer having two (meth) acryloyl groups and has a polyalkylene oxide chain between two (meth) acryloyl groups, The number of the shortest atoms connecting two (meth) acryloyl groups is 13 or more.

Generally, when a monofunctional (meth) acrylic monomer is used, a linear polymer is formed at the time of curing. Thus, for example, even if a cured product (cured film) is peeled off from an object to be adhered by using a cellophane tape, it is difficult to peel off because of its presupposition. In addition, when a common trifunctional or higher (meth) acrylic monomer is used, a dense network structure is formed at the time of curing. Thus, for example, even if a cured product is peeled from an object to be adhered by using a cellophane tape, it is difficult to peel off during peeling.

On the contrary, since the first (meth) acrylic monomer is bifunctional and the distance between the two (meth) acryloyl groups is long, a loose network structure is formed at the time of curing. Thereby, the cured product of the adhesive composition can be easily peeled off from the object to be adhered.

Each alkylene oxide group constituting the polyalkylene oxide chain may be represented by any one of -AO- and -OA- when the alkylene group is represented by A. [ The number of carbon atoms is preferably 2 to 6, more preferably 2 to 5. The polyalkylene oxide chain may contain alkylene oxide groups having different carbon numbers. The number of repeating alkylene oxide groups is preferably from 2 to 35, more preferably from 3 to 30, still more preferably from 3 to 20.

The upper limit of the number of the shortest atoms connecting two (meth) acryloyl groups is not particularly limited, but is about 110. The number of the shortest atoms is preferably from 13 to 101, more preferably from 15 to 90, and even more preferably from 20 to 70. When the number of the shortest atoms is 60 or more, the ratio of oxygen atoms to carbon atoms in all the atoms existing between the two (meth) acryloyl groups is preferably 50% or less, more preferably 35 to 45% desirable.

As the first (meth) acrylic monomer, for example, those represented by the following formula (I) can be used. However, also in this case, the number of the shortest atoms connecting two (meth) acryloyl groups is 13 or more.

[Chemical Formula 1]

In the formula (I), R ⁰ represents a hydrogen atom or a methyl group, R ¹ and R ² each independently represent a single bond or an alkylene group having 1 to 10 carbon atoms which may have a hydroxyl group, an ether bond or a urethane bond .

R ³ represents a single bond or a divalent organic group. The divalent organic group may be a chain or cyclic aliphatic group, an aromatic group, or a combination thereof, and may have a hydroxyl group, an ether bond, or a urethane bond.

Each X independently represents an alkylene oxide group having 2 to 6 carbon atoms. The carbon number of X may be different for each repeating unit.

m1 and m2 each independently represent an integer of 1 to 30; In addition, when the m1 = m2 = 1, R ³ becomes a single bond.

As the (meth) acrylic monomer represented by the above formula (I), for example, those represented by the following formulas (I-1) to (I-3) can be used.

(2)

In the formulas (I-1) to (I-3), R ⁰ has the same meaning as in formula (I), A represents an alkylene group having 2 to 6 carbon atoms, an alkylene oxide group (-AO-, The carbon number of A may be different for each repeating unit of OA-.

In the formula (I-1), m5 represents an integer of 2 to 15.

In the formula (I-2), m6 and m7 each independently represent an integer of 2 to 30, preferably an integer of 2 to 20.

In the formula (I-3), R ⁵ and R ⁶ each independently represent an alkylene group having 1 to 5 carbon atoms which may have a hydroxyl group or a urethane bond, and at least one of R ⁵ and R ⁶ is a hydroxyl group or a urethane bond And m8 represents an integer of 2 to 15.

Next, the second (meth) acrylic monomer is an n-functional (meth) acrylic monomer having n (n is an integer of 3 or more) as the (meth) acryloyl group, And the number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more.

As described above, when a common trifunctional or more (meth) acrylic monomer is used, a dense network structure is formed at the time of curing. Thus, for example, even if a cured product (cured film) is peeled from an object to be adhered by using a cellophane tape, it is difficult to peel off during peeling.

On the other hand, the second (meth) acrylic monomer has a long distance between any two (meth) acryloyl groups, so that a loose network structure is formed at the time of curing. Thereby, the cured product of the adhesive composition can be easily peeled off from the object to be adhered.

The number n of (meth) acryloyl groups is preferably from 3 to 4, more preferably 3.

Each alkylene oxide group constituting the polyalkylene oxide chain may be represented by any one of -AO- and -OA- when the alkylene group is represented by A. [ The number of carbon atoms is preferably 2 to 6, more preferably 2 to 5. The polyalkylene oxide chain may contain alkylene oxide groups having different carbon numbers. The number of alkylene oxide groups between any two (meth) acryloyl groups is preferably 2 to 20, more preferably 3 to 10.

The upper limit of the number of the shortest atoms connecting any two (meth) acryloyl groups is not particularly limited, but is about 60. The number of the shortest atom is preferably from 20 to 55, more preferably from 30 to 50.

As the second (meth) acrylic monomer, for example, those having n structures represented by the following formula (II) can be used. However, also in this case, the number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more.

(3)

In the formula (II), R ⁰ , R ¹ , R ² , R ³ , X, m 1 and m 2 have the same meanings as in the formula (I).

More specifically, as the (meth) acrylic monomer having n structures represented by the above formula (II), for example, those represented by the following formula (II-1) can be used.

[Chemical Formula 4]

In the formula (II-1), R ⁰ has the same meaning as in formula (I), A represents an alkylene group having 2 to 6 carbon atoms, and a repeating unit of an alkylene oxide group (-AO-, -OA-) The carbon number of each A may be different.

R ¹⁰ , R ¹¹ and R ¹² each independently represent a single bond or an alkylene group having 1 to 5 carbon atoms. It is preferable that any one of R ¹⁰ , R ¹¹ and R ¹² is a single bond and the remaining two are methylene groups.

m10, m11 and m12 each independently represent an integer of 2 to 10; Provided that the number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more.

Among the above-mentioned first and second (meth) acrylic monomers, from the viewpoint of coating properties, it is preferable that the liquid monomer is liquid at 25 占 폚.

It is preferable that the first and second (meth) acrylic monomers are selected so that the cured product has a modulus of elasticity of about 5 × 10 ⁶ Pa or less. By lowering the modulus of elasticity of the cured product as described above, the cured product is made flexible, and the workability is improved.

It is preferable that the first and second (meth) acrylic monomers are selected so that the cured product has an appropriate hardness. Specifically, it is preferable that the carbon atom (s) of the oxygen atom in all the atoms present between two (meth) acryloyl groups (between any two (meth) acryloyl groups in the case of the second (Meth) acrylic monomer having a proportion of 60% or less, preferably 30 to 55%, more preferably 30% or more and less than 55%, based on the total weight of the composition. In particular, when the above ratios are equivalent, it is preferable to select a methacryl monomer rather than an acrylic monomer, or to select a (meth) acrylic monomer having a hydroxyl group as a substituent other than an alkylene oxide chain.

When transparency is required for the cured product, it is preferable that the first and second (meth) acrylic monomers are selected so that the cured product becomes colorless and transparent.

When water resistance is required for the cured product, it is preferable that the first and second (meth) acrylic monomers have an alkylene oxide group having 3 or more carbon atoms. When the number of carbon atoms of the alkylene oxide group relative to the first (meth) acrylic monomer is 2, the number of repeating units is preferably 2 to 4.

The adhesive composition according to the present invention preferably contains at least one (meth) acrylic monomer of the first (meth) acrylic monomer or the second (meth) acrylic monomer in an amount of 35 to 99 mass% with respect to the total adhesive composition , More preferably from 44 to 98%, even more preferably from 50 to 98% by mass, particularly preferably from 65 to 98% by mass.

≪ Other polymerizable monomers >

The adhesive composition according to the present invention may contain a polymerizable monomer other than the first and second (meth) acrylic monomers as long as the effect of the present invention is not impaired. In particular, by containing a polymerizable monomer having a low Tg, the elastic modulus of the cured product can be lowered.

However, the content of the first and second (meth) acrylic monomers is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more based on the total amount of the monomers.

When the other polymerizable monomer is contained, the amount is preferably 0.5 to 70 mass%, more preferably 1 to 50 mass%, and even more preferably 1 to 40 mass% with respect to the total amount of the monomers.

Such other polymerizable monomers may be monofunctional or polyfunctional, but monofunctional is preferred. Examples of the monofunctional polymerizable monomer include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, (Meth) acrylates such as ethylene glycol monomethyl (meth) acrylate, propylene glycol mono (meth) acrylate and the like; alkylene glycol mono (Meth) acryloyloxy-2-hydroxypropyl phthalate, glycerin mono (meth) acrylate, and the like.

These polymerizable monomers may be used alone or in combination of two or more.

<Photopolymerization initiator>

The photopolymerization initiator is not particularly limited, and conventionally known photopolymerization initiators can be used. Specific examples thereof include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2- hydroxyethoxy) Methyl-1-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy- 2-methylpropane-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis (4-dimethylaminophenyl) (Methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino- 3-yl], 1- (O-acetyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2-methylbenzoyl) Trimethylbenzoyl) -phenylphosphine oxide, 4-benzoyl-4'-methyldimethylsulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, Butyl, 4-dimethylamino-2-ethyl Hexylbenzoic acid, 4-dimethylamino-2-isoamylbenzoic acid, benzyl- beta -methoxyethyl acetal, benzyldimethyl ketal, 1-phenyl-1,2-propanedioyl- 2- (o-ethoxycarbonyl) oxime, benzoyl benzoic acid methyl, 2,4-diethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thioxanthone, 1-chloro-4- propanedioxanthone, 2-ethyl anthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2-benzoanthraquinone, 2-methylthioxanthone, , 3-diphenylanthraquinone, azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzoimidal, 2-mercaptobenzoxazole, 2- mercaptobenzothiazole, 2- -Chlorophenyl) -4,5-di (m-methoxyphenyl) -imidazolyl dimer, benzophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, 4,4'-bis Diethylaminobenzophenone, 4,4'-dichlorobenzo Phenol, 3,3-dimethyl-4-methoxybenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, Benzoin butyl ether, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p- Butyl dichloroacetophenone, p-tert-butyldichloroacetophenone,?,? -Dichloro-4-phenoxyacetophenone, thioxanthone, 2-methylthioxanthone, 2- (9-acridinyl) heptane, 1,5-bis- (9-methoxybenzyl) heptane, isopropyl thioxanthone, dibenzosuberone, pentyl-4-dimethylaminobenzoate, -Acryidinyl) pentane, 1,3-bis- (9-acridinyl) propane, p-methoxytriazine, 2,4,6-tris (trichloromethyl) -4,6-bis ( (Trichloromethyl) -s-triazine, 2- [2- (5-methylfuran-2-yl) ethenyl] (Trichloromethyl) -s-triazine, 2- [2- (4-diethylamino-2-methylphenyl) ethenyl] -4,6 (Trichloromethyl) -s-triazine, 2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis 4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxystyryl) Bis (trichloromethyl) -s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy Phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4- methoxy) (3-bromo-4-methoxy) styrylphenyl-s-triazine, 2,4-bis- trichloromethyl-6- Azine, and the like.

These photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator is preferably 1 to 15 parts by mass, more preferably 2 to 10 parts by mass, and still more preferably 3 to 8 parts by mass with respect to 100 parts by mass of the monomer in the adhesive composition. By setting the ratio to the above range, it is possible to suppress the hardening failure.

<Cellulose Resin>

The adhesive composition according to the present invention may contain a cellulose resin within the range not impairing the effect of the present invention.

Examples of the cellulose-based resin include acylated cellulose in which a part or all of the hydroxyl groups of cellulose and cellulose are acylated. Examples of the acyl group include an acetyl group and a butyryl group. Of these cellulose-based resins, cellulose acetate butyrate (CAB) is particularly preferable.

The content of the cellulose-based resin is preferably 0 to 30 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the monomer in the adhesive composition. By setting the viscosity in the above range, the viscosity of the adhesive composition can be increased to about 100 to 100000 cP, so that the film thickness when the adhesive composition is applied can be increased.

&Lt; Other components &gt;

The adhesive composition according to the present invention preferably does not contain a solvent, but may contain a small amount of an organic solvent as long as the effect of the present invention is not impaired. In this case, the content of the organic solvent in the adhesive composition is preferably 20 mass% or less, more preferably 10 mass% or less.

Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n- Propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol mono (Poly) alkyl (meth) acrylate such as methyl ether, tripropylene glycol monoethyl ether, Glycol monoalkyl ethers such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like (Poly) alkylene glycol monoalkyl ether acetates such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran, etc., ethers such as methyl ethyl ketone, cyclohexanone, 2-heptanone and 3-heptanone; alkyl lactates such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate , Ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, Methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, Propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl formate, i-pentyl acetate, n-butyl propionate, ethyl butyrate , Other esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, n-butyl acetate, isopropyl lactate, Amines such as N-methylpyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide, and the like.

These organic solvents may be used alone or in combination of two or more.

The adhesive composition according to the present invention may contain a silane coupling agent, a polymerization inhibitor, a leveling agent, a surface lubricant, a defoamer, a light stabilizer, an antioxidant, a plasticizer, an antistatic agent, And may contain various additives.

The adhesive composition according to the present invention contains the above-mentioned &quot; specific (meth) acrylic monomer &quot; and &quot; photopolymerization initiator &quot; as main constituent components and, if necessary, <other polymerizable monomer>, & Of other components. Among them, the proportion of the components other than the solvent in the adhesive composition is preferably 70 to 100 mass% or more, more preferably 80 to 100 mass%, still more preferably 90 to 100 mass%.

«Adhesion method and peeling method»

In order to bond the objects to be adhered using the adhesive composition related to the present invention, at first, at least one of the surfaces of the object to be adhered is coated with a coating film of a coating film by using a coating device such as a roll coater, a spin coater, The adhesive composition is applied so that the thickness is 5 to 1000 mu m, preferably 10 to 500 mu m. Examples of the object to be adhered include a glass plate, an acrylic plate, and a polyethylene terephthalate (PET) film.

Subsequently, the objects to be adhered are bonded together, and an active energy ray such as an ultraviolet ray or a visible laser is irradiated to cure the coated film. The dose varies depending on the composition of the adhesive composition. For example, it is preferably about 100 to 2000 mJ / cm 2.

Here, when foreign matter or air enters the coplanar surface, or the position of fusion is wrong and causes a positional deviation, the objects to be adhered are removed first.

Subsequently, the cured product (cured film) of the adhesive composition remaining on the concave surface of the object to be adhered is peeled off. For example, the cured product can be easily peeled off by attaching a cellophane tape to the end of the cured product and removing the cellophane tape. The cured product can also be peeled off by immersing in water at room temperature (23 ° C) to 100 ° C for 10 seconds to 60 minutes.

Example

Hereinafter, the embodiments of the present invention will be described, but the scope of the present invention is not limited to these embodiments.

Among the polymerizable monomers used in the following examples, structural formulas other than UA4400 are shown below. UA4400 is a bifunctional acrylic monomer having a molecular weight of about 1300 and having an alkylene oxide chain of 5 carbon atoms.

Among these polymerizable monomers, PE-90, 200, 250, PP-1000, 500, 800, 50PEP-300 and 70PEP-350B were manufactured by Nitto Kasei, HO-MPP by Kyoeisha Chemical Co., -5700 is manufactured by Toa Synthetic Resin Co., and the remainder is manufactured by Shin Nakamura Chemical Industry Co., Ltd.

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

The photopolymerization initiator and the cellulose resin used in the following examples are as follows.

ㆍ Photopolymerization initiator

IR-907: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (IRGACURE 907, manufactured by Ciba Specialty Chemicals)

IR-184: 1-Hydroxy-cyclohexyl-phenyl-ketone ("IRGACURE 184", manufactured by Ciba Specialty Chemicals)

ㆍ Cellulosic resin

CAB1: cellulose acetate butyrate ("CAB-551-0.2", manufactured by Eastman Chemical Company)

CAB2: cellulose acetate butyrate ("CAB-381-0.5", manufactured by Eastman Chemical Company)

CAB3: cellulose acetate butyrate ("CAB-381-2", manufactured by Eastman Chemical Company)

&Lt; Examples 1 to 22, Comparative Examples 1 to 28 &gt;

The components described in Tables 1 to 6 were mixed to prepare an adhesive composition. The numbers in [] indicate the mass parts. For the polymerizable monomer, the number of the shortest atoms connecting the two (meth) acryloyl groups (in the case of bifunctional) or the number of the shortest atoms connecting the two (meth) acryloyl groups in the case of trifunctional or more, Are also shown in the table.

In addition, only the adhesive composition of Example 18 contained a cellulose resin, and the viscosity thereof was 1100 cP.

[Evaluation of reworkability]

The adhesive compositions of Examples 1 to 22 and Comparative Examples 1 to 28 were coated on a glass substrate using a screen printing machine to form a coating film having a thickness of 90 탆. Subsequently, a glass substrate was further laminated on the coated film, and ultraviolet rays were irradiated thereon at an irradiation dose of 500 to 2000 mJ / cm &lt; 2 &gt; to cure the coated film. Any composition or glass substrate could be bonded together. Thereafter, one of the glass substrates was removed. Then, when a cellophane tape (manufactured by Nikki Reflection) is attached to the cured film of the adhesive composition remaining on the glass substrate and the cured film is entirely peeled off when it is peeled off, the workability is good, And the reworkability was evaluated as poor. Also, it was evaluated that the one glass substrate could not be peeled off prior to peeling by the cellophane tape. The results are shown in Tables 1 to 6.

[Evaluation of hardening shrinkability]

The adhesive compositions of Examples 1 to 22 and Comparative Examples 1 to 28 were coated on a glass substrate using a screen printing machine to form a coating film having a thickness of 90 탆. Subsequently, a silicone-based releasing PET film (thin film) was laminated on the coating film, and ultraviolet rays were irradiated from the side of the releasing PET film at an irradiation dose of 500 to 2000 mJ / cm 2 to cure the coating film. In addition, evaluation was made that no curing shrinkage occurred in which the flexure occurred in the release PET film, and no hardening shrinkage in which no flexure occurred. The results are shown in Tables 1 to 6.

[Evaluation of hardness]

The hardness of the cured film was evaluated by the following three steps (1 is particularly preferable). The results are shown in Tables 1 to 6.

0: Hard

1: Soft and tender

2: Too soft

[Cross hatch test]

A glass substrate and a silicone type release PET film (thick film) were bonded to each other in the same manner as in the evaluation of the curing shrinkability, and the coating film was cured by irradiating ultraviolet rays from the releasing PET film side. Thereafter, the release PET film was peeled off. In addition, since the releasing PET film is used in this evaluation, the releasing PET film can be peeled off even when an adhesive composition which can not be peeled from the glass substrate in the above-described [evaluation of reworkability] is used. Then, using a cutter knife, 100 cross hatches (graduations) of 1 mm x 1 mm were formed on the cured film remaining on the glass substrate, and a cellophane tape (manufactured by Nichia Corporation) was stuck thereon and peeled off. Then, from the point where the number of scales separated from the glass substrate was large, it was evaluated from 0 point to 10 point. The results are shown in Tables 1 to 6. In addition, the score of the cross-hatch test is low from the viewpoint of reworkability.

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Comparative Example 1 A-DCP [100]
(Sensory number = 2
The shortest number of atoms = 9) IR-907
[8] - Bad has exist 0 0 point Comparative Example 2 701 [100]
(Sensory number = 2
The shortest number of atoms = 5) IR-907
[8] - Bad has exist 0 0 point Comparative Example 3 A-NOD-N [100]
(Sensory number = 2
The shortest number of atoms = 11) IR-907
[8] - Bad has exist 0 0 point Comparative Example 4 NOD-N [100]
(Sensory number = 2
The shortest number of atoms = 11) IR-907
[8] - Bad has exist 0 0 point Comparative Example 5 A-DOG [100]
(Sensory number = 2
The shortest number of atoms = 9) IR-907
[8] - Bad has exist 0 0 point Comparative Example 6 A-NPG [100]
(Sensory number = 2
The shortest number of atoms = 5) IR-907
[8] - Bad has exist 0 0 point Comparative Example 7 NPG [100]
(Sensory number = 2
The shortest number of atoms = 5) IR-907
[8] - Bad has exist 0 0 point Comparative Example 8 1G [100]
(Sensory number = 2
The shortest number of atoms = 4) IR-907
[8] - Bad has exist 0 0 point Comparative Example 9 2G [100]
(Sensory number = 2
The shortest number of atoms = 7) IR-907
[8] - Bad has exist 0 0 point Comparative Example 10 3G [100]
(Sensory number = 2
The shortest number of atoms = 10) IR-907
[8] - Bad has exist 0 0 point

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Example 1 4G [100]
(Sensory number = 2
The shortest number of atoms = 13) IR-907
[8] - Good has exist One 0 point Example 2 9PG [100]
(Sensory number = 2
The shortest number of atoms = 22) IR-907
[8] - Good none One 0 point Example 3 9G [100]
(Sensory number = 2
The shortest number of atoms = 28) IR-907
[8] - Good none One 0 point Example 4 14G [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-907
[8] - Good none One 0 point Example 5 A-400 [100]
(Sensory number = 2
The shortest number of atoms = 28) IR-907
[8] - Good has exist One 0 point Example 6 A-600 [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-907
[8] - Good none One 0 point Example 7 A-PTMG-65 [100]
(Sensory number = 2
The shortest number of atoms = 46) IR-907
[8] - Good has exist One 0 point Example 8 A-BPE-4 [100]
(Sensory number = 2
The shortest number of atoms = 23) IR-907
[8] - Good has exist 0 0 point Example 9 A-BPE-10 [100]
(Sensory number = 2
The shortest number of atoms = 41) IR-907
[8] - Good none One 0 point

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Example 10 A-BPE-20 [100]
(Sensory number = 2
The shortest number of atoms = 71) IR-907
[8] - Good none One 0 point Example 11 BPE-500 [100]
(Sensory number = 2
The shortest number of atoms = 41) IR-907
[8] - Good none One 0 point Example 12 BPE-1300N [100]
(Sensory number = 2
The shortest number of atoms = 71) IR-907
[8] - Good none One 0 point Example 13 EMA-5822 [100]
(Sensory number = 2
The shortest number of atoms = 22) IR-907
[8] - Good none One 0 point Example 14 EMA-5823 [100]
(Sensory number = 2
The shortest number of atoms = 37) IR-907
[8] - Good none One 0 point Example 15 EMA-5824 [100]
(Sensory number = 2
The shortest number of atoms = 49) IR-907
[8] - Good none One 0 point Example 16 1206PE [100]
(Sensory number = 2
The shortest number of atoms = 55) IR-184
[4] - Good none One 0 point Example 17 UA-4400 [100]
(Sensory number = 2
The shortest number of atoms = 29-85) IR-184
[4] - Good none One 0 point Example 18 14G [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-907
[8] CAB1
[4] Good none One 0 point

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Example 19 14G [60]
(Sensory number = 2
The shortest number of atoms = 43)
HO-MPP [40]
(Sensory number = 1) IR-184
[4] - Good has exist One 0 point Example 20 14G [75]
(Sensory number = 2
The shortest number of atoms = 43)
HO-MPP [25]
(Sensory number = 1) IR-184
[4] - Good has exist One 0 point Example 21 14G [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-184
[4] - Good has exist One 0 point

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Comparative Example 11 A-GLY-3E [100]
(Sensory number = 3
The shortest number of atoms = 10) IR-907
[4] - Bad has exist 0 0 point Comparative Example 12 A-GLY-9E [100]
(Sensory number = 3
The shortest number of atoms = 22) IR-907
[4] - Bad none 0 0 point Example 22 A-GLY-20E [100]
(Sensory number = 3
The shortest number of atoms = 45) IR-907
[4] - Good none 0 0 point Comparative Example 13 AD-TMP [100]
(Sensory number = 3
The shortest number of atoms = 9) IR-907
[4] - Bad none 0 0 point Comparative Example 14 A-DPH [100]
(Sensory number = 6
The shortest number of atoms = 9) IR-907
[4] - Bad none 0 0 point

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Comparative Example 15 AMP-10G [100]
(Sensory number = 1) IR-907
[8] - Bad has exist 2 10 points Comparative Example 16 PHE-1G [100]
(Sensory number = 1) IR-907
[8] - Bad has exist 0 0 point Comparative Example 17 M-20G [100]
(Sensory number = 1) IR-907
[4] - Bad none 2 0 point Comparative Example 18 M-40G [100]
(Sensory number = 1) IR-907
[4] - Bad none 2 0 point Comparative Example 19 M-90G [100]
(Sensory number = 1) IR-907
[4] - Bad none 2 0 point Comparative Example 20 PE-90 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 21 PE-200 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 22 PE-350 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 23 PP-1000 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 24 PP-500 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 25 PP-800 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 26 50PEP-300 [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 27 70PEP-350B [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points Comparative Example 28 HO-MPP [100]
(Sensory number = 1) IR-907
[4] - Bad none One 10 points

As can be seen from Tables 1 to 6, the cured products obtained by curing the adhesive compositions of Examples 1 to 22 containing the above-described first and second (meth) acrylic monomers as polymerizable monomers were all reworked It is possible to detach one of the glass substrates even if the glass substrates are adhered to each other, and the cured film itself remaining on the other glass substrate can be easily peeled off with the cellophane tape. This workability was also good in the case of further containing a cellulose resin (Example 18) or in the case of containing a monofunctional (meth) acrylic monomer (Examples 19 and 20).

On the other hand, the adhesive compositions of Comparative Examples 1 to 28, which contained only bifunctional or trifunctional (meth) acryl monomers having a short distance between (meth) acryloyl groups or only monofunctional (meth) acryl monomers as polymerizable monomers It was difficult to peel off all the cured products.

&Lt; Examples 23 to 33 &gt;

The components described in Table 7 below were mixed to prepare an adhesive composition. The numbers in [] indicate the mass parts. With respect to the polymerizable monomer, the shortest number of atoms connecting two (meth) acryloyl groups is also shown in the table. Further, evaluation of the reworkability was carried out in the same manner as in the evaluation of the reworkability described above, but it was confirmed that the adhesive compositions and the workability of Examples 23 to 33 were satisfactory.

[Evaluation of elastic modulus]

The adhesive compositions of Examples 23 to 33 were coated on a glass substrate using a screen printing machine to form a coating film having a thickness of 800 탆. Subsequently, a glass substrate was further laminated on the coated film, and ultraviolet rays were irradiated thereon at an irradiation dose of 500 to 2000 mJ / cm &lt; 2 &gt; to cure the coated film. Thereafter, one of the glass substrates was removed. Then, under the condition of applying a weight of 50 mN (± 10 mN) at a cycle of 0.01 Hz using TMA (thermomechanical analyzer, Seiko Instruments Inc.), the elastic modulus of the cured film of the adhesive composition remaining on the other glass substrate Were measured. The results are shown in Table 7.

[Evaluation of water resistance]

The adhesive compositions of Examples 23 to 29 were coated on a glass substrate using a screen printing machine to form a coating film having a thickness of 180 占 퐉. Subsequently, a glass substrate was further laminated on the coated film, and ultraviolet rays were irradiated thereon at an irradiation dose of 500 to 2000 mJ / cm &lt; 2 &gt; to cure the coated film. Thereafter, one of the glass substrates was removed. Then, the cured film of the adhesive composition remaining on the other glass substrate was immersed in an aqueous solution containing 0.02 mass% of KOH per glass substrate for 10 minutes, and the change of the film thickness was measured. Then, it was evaluated as? When the change in film thickness was less than 5%, and? When the change in film thickness was 5% or more before or after immersion in the aqueous solution. The results are shown in Table 7.

Polymerizable monomer Photopolymerization initiator Cellulose resin Modulus of elasticity (Pa) Water resistance Example 23 9PG [100]
(Sensory number = 2
The shortest number of atoms = 22) IR-907
[8] - 1.77 × 10 ⁶ ○
(0%) Example 24 12PG [100]
(Sensory number = 2
The shortest number of atoms = 37) IR-907
[8] - 4.26 × 10 ⁵ ○
(0%) Example 25 4G [100]
(Sensory number = 2
The shortest number of atoms = 13) IR-907
[8] - 4.31 × 10 ⁶ ○
(0.6%) Example 26 9G [100]
(Sensory number = 2
The shortest number of atoms = 28) IR-907
[8] - 9.71 × 10 ⁵ △
(5.1%) Example 27 14G [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-907
[8] - 5.52 × 10 ⁵ △
(5.6%) Example 28 1206PE [100]
(Sensory number = 2
The shortest number of atoms = 55) IR-907
[8] - 2.89 × 10 ⁵ ○
(0%) Example 29 A-PTMG-65 [100]
(Sensory number = 2
The shortest number of atoms = 46) IR-907
[8] - 4.0 × 10 ⁵ ○
(0%) Example 30 9PG [50]
(Sensory number = 2
The shortest number of atoms = 22)
M-90G [50]
(Sensory number = 1) IR-907
[8] CAB1
[10] 2.96 × 10 ⁵ - Example 31 9PG [67]
(Sensory number = 2
The shortest number of atoms = 22)
M-90G [33]
(Sensory number = 1) IR-907
[8] CAB1
[10] 5.26 × 10 ⁵ - Example 32 9PG [80]
(Sensory number = 2
The shortest number of atoms = 22)
M-90G [20]
(Sensory number = 1) IR-907
[8] CAB1
[10] 7.34 × 10 ⁵ - Example 33 9PG [100]
(Sensory number = 2
The shortest number of atoms = 22) IR-907
[8] CAB1
[10] 2.46 × 10 ⁶ -

As can be seen from Table 7, all of the cured products obtained by curing the adhesive compositions of Examples 23 to 33 had a low elastic modulus of 5 x 10 &lt; ⁶ &gt; Pa or less. In particular, as the distance between the two (meth) acryloyl groups became longer, the elastic modulus decreased. Further, when the monofunctional monomer, M-90G, was contained, the modulus of elasticity was lowered as the ratio increased.

As can be seen from Table 7, all of the cured products obtained by curing the adhesive compositions of Examples 23 to 29 were good in water resistance, but in Examples 23 to 24, 28 and 29 having an alkylene oxide group having 3 or more carbon atoms , And the adhesive composition of Example 25 in which the alkylene oxide group had 2 carbon atoms and the number of repetitions was 4 was excellent in water resistance.

&Lt; Examples 34 to 37 &gt;

The components shown in Table 8 below were mixed to prepare an adhesive composition. The numbers in [] indicate the mass parts. With respect to the polymerizable monomer, the shortest number of atoms connecting two (meth) acryloyl groups is also shown in the table.

[Evaluation of reworkability by water]

The adhesive compositions of Examples 34 to 37 were coated on a glass substrate using a screen printing machine to form a coating film having a thickness of 90 占 퐉. Subsequently, a glass substrate was further laminated on the coated film, and ultraviolet rays were irradiated thereon at an irradiation dose of 500 to 2000 mJ / cm &lt; 2 &gt; to cure the coated film. Thereafter, one of the glass substrates was removed. Then, the cured film of the adhesive composition remaining on the other glass substrate was immersed in water at 23 deg. C, 50 deg. C and 80 deg. C for each glass substrate, and the time (seconds) until the cured film was peeled off was measured. The results are shown in Table 8.

Polymerizable monomer Photopolymerization initiator Time to peel off (seconds) 80 ℃ 50 ℃ 23 ℃ Example 34 14G [60]
(Sensory number = 2
The shortest number of atoms = 43)
HO-MPP [40]
(Sensory number = 1) IR-907
[8] 60 160 1200 Example 35 A-PTMG-65 [50]
(Sensory number = 2
The shortest number of atoms = 46)
HO-MPP [50]
(Sensory number = 1) IR-907
[8] 85 300 3600 Example 36 A-PTMG-65 [67]
(Sensory number = 2
The shortest number of atoms = 46)
HO-MPP [33]
(Sensory number = 1) IR-907
[8] 50 280 3600 Example 37 A-PTMG-65 [100]
(Sensory number = 2
The shortest number of atoms = 46) IR-907
[8] 40 240 3600

As can be seen from Table 8, all of the cured products obtained by curing the adhesive compositions of Examples 33 to 36 could be peeled off by dipping in water, and the time until peeling became shorter as the temperature of water was higher. Further, the higher the proportion of the first (meth) acrylic monomer in the whole of the monomer, the shorter the time to peeling.

&Lt; Examples 38 to 40 and Comparative Example 29 &gt;

The components shown in Table 9 below were mixed to prepare an adhesive composition. The numbers in [] indicate the mass parts. With respect to the polymerizable monomer, the shortest number of atoms connecting two (meth) acryloyl groups is also shown in the table.

The adhesive compositions of Examples 38 to 40 and Comparative Example 29 were evaluated for reworkability, evaluation of hardening shrinkability, evaluation of hardness and cross hatch test in the same manner as described above. The results are shown in Table 9.

Polymerizable monomer Photopolymerization initiator Cellulose resin Re-workability Hardening shrinkage Hardness Cross hatch Example 38 14G [100]
(Sensory number = 2
The shortest number of atoms = 43) IR-907
[8] CAB2
[4]
Good none One 0 point Example 39 9PG [50]
(Sensory number = 2
The shortest number of atoms = 22)
M-40G [50]
(Sensory number = 1) IR-184
[2] CAB3
[11] Good none One 0 point Example 40 1206PE [50]
(Sensory number = 2
The shortest number of atoms = 55)
M-40G [50]
(Sensory number = 1) IR-184
[2] CAB3
[9] Good none One 0 point Comparative Example
29 AM-30G [20]
(Sensory number = 1)
M-5700 [80]
(Sensory number = 1) IR-184
[2] CAB3
[9] Bad has exist One 10 points

As can be seen from Table 9, all of the cured products obtained by curing the adhesive compositions of Examples 38 to 40 containing the above-mentioned first and second (meth) acrylic monomers as polymerizable monomers exhibited reworkability It is possible to detach one of the glass substrates even if the glass substrates are adhered to each other, and the cured film itself remaining on the other glass substrate can be easily peeled off with the cellophane tape. This reworkability was also good in the case where the content of the cellulose resin was increased and half of the polymerizable monomer was a monofunctional (meth) acrylic monomer (Examples 39 and 40).

On the other hand, it was difficult to peel a cured product obtained by curing the adhesive composition of Comparative Example 29 containing only a monofunctional (meth) acrylic monomer as a polymerizable monomer.

Claims (5)

An adhesive composition containing the (meth) acrylic monomer of the following (2) and a photopolymerization initiator and not containing a monofunctional (meth) acryl monomer having one (meth) acryloyl group.
(2) An n-functional (meth) acryl monomer having n (meth) acryloyl groups (n is an integer of 3 or more), and has a polyalkylene oxide chain between any two (meth) acryloyl groups The number of the shortest atoms connecting any two (meth) acryloyl groups is 23 or more, and n structures represented by the following formula (II).
(2)

(Wherein R ⁰ represents a hydrogen atom or a methyl group, R ¹ and R ² each independently represent a single bond or an alkylene group having 1 to 10 carbon atoms which may have a hydroxyl group, an ether bond or a urethane bond, R ³ represents a single bond or a divalent organic group, each X independently represents an alkylene oxide group having 2 to 6 carbon atoms, m1 and m2 each independently represent an integer of 1 to 30.) The method according to claim 1,
Wherein the content of the (meth) acrylic monomer (2) is 30% by mass or more based on the total amount of the monomers. delete delete 3. The method according to claim 1 or 2,
Further comprising a cellulose resin.