JP3498156B2 - Pressure sensitive adhesive composition for liquid crystal device and liquid crystal device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive composition for a liquid crystal element or a liquid crystal display device (hereinafter, sometimes simply referred to as “liquid crystal element”) and the pressure-sensitive adhesive composition. The present invention relates to a manufactured liquid crystal element. More specifically, the present invention is peelable at the time of manufacturing a liquid crystal display device,
The present invention relates to a pressure-sensitive adhesive composition for a liquid crystal element that has excellent durability under high temperature and high humidity conditions, and a liquid crystal element manufactured using the pressure-sensitive adhesive composition.

[0002]

BACKGROUND OF THE INVENTION A liquid crystal element is composed of two substrates having transparent electrodes arranged on the surface in contact with liquid crystal, a liquid crystal material filled between the two substrates, and outer surfaces of the two substrates. Or a laminated plate of a polarizing plate and a retardation plate.

In such a liquid crystal element, a polarizing plate or a laminated plate of a polarizing plate and a retardation plate is attached to the surface of a substrate by using a pressure sensitive adhesive. An acrylic resin is often used as a pressure-sensitive adhesive used for attaching such a polarizing plate or a laminated plate of a polarizing plate and a retardation plate to the surface of a substrate.

In recent years, the liquid crystal element has been used in a remarkably wide range of applications such as a display unit of a desk-top electronic computer, a display panel of a personal computer, a liquid crystal display device mounted on a vehicle, and a screen of a television, and thus the application is expanded. Accordingly, the usage environment of liquid crystal elements has become extremely severe. Accordingly, it is desirable that the adhesive strength between the polarizing plate or the laminated plate of the polarizing plate and the retardation plate and the glass is high so as to withstand such use conditions, and that the high adhesive strength does not fluctuate for a long period of time. From this point of view, an acrylic resin adhesive is used.

By the way, in the process of manufacturing a liquid crystal element using such an adhesive, when a problem occurs in bonding the polarizing plate or the laminated plate of the polarizing plate and the retardation plate,
It is necessary to peel off the polarizing plate or the laminated plate of the polarizing plate and the retardation plate, and reattach the polarizing plate or the laminated plate of the polarizing plate and the retardation plate to manufacture a liquid crystal element. That is,
Compared with a polarizing plate or a laminated plate of a polarizing plate and a retardation plate, the liquid crystal cell and the liquid crystal material filled in the cell are extremely expensive, and thus the polarizing plate or the polarizing plate and the retardation plate are Since the liquid crystal material and the cell itself filled with the liquid crystal material often have no problem even if the laminated plate is poorly adhered, reattach the polarizing plate or the laminated plate of the polarizing plate and the retardation plate. If so, good liquid crystal performance is exhibited.

However, since the environment in which the liquid crystal element is used has become considerably severe as described above, the adhesive strength of the adhesive for adhering the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is also extremely high. A polarizing plate or a laminated plate of a polarizing plate and a retardation film, which is pasted with an acrylic resin adhesive that has been conventionally used, has a high adhesive strength, and therefore, a glass substrate is used when peeling. In many cases, it cannot be used as a liquid crystal element because it is damaged or the width of the gap filled with the liquid crystal material changes. Further, even if the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is peeled off, the adhesive remains on the glass substrate, and in fact, a new polarizing plate or the laminated plate of the polarizing plate and the retardation plate is attached. There is a problem that you cannot wear it.

Considering the current state of use of liquid crystal elements, in which such an adhesive agent for a liquid crystal element is exposed to high temperature and high humidity conditions such as when it is used for a vehicle-mounted liquid crystal element, an adhesive agent for a liquid crystal element is Even when used under such high temperature and high humidity conditions, the property (durability) of preventing foaming or peeling of the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is required.

As described above, the pressure-sensitive adhesive used for sticking the polarizing plate or the laminated plate of the polarizing plate and the retardation plate to the glass substrate of the liquid crystal element can maintain stable adhesive strength for a long period of time. That is, there is a contradictory characteristic that the polarizing plate or the laminated plate of the polarizing plate and the retardation plate can be easily peeled off without damaging the liquid crystal element when peeling.

[0009]

An object of the present invention is to provide a pressure-sensitive adhesive composition which is particularly suitable for adhering a glass substrate and a polarizing plate or a glass substrate and a laminated plate of a polarizing plate and a retardation plate. I am trying.

More specifically, the present invention surely adheres a polarizing plate or a laminated plate of a polarizing plate and a retardation plate to a glass substrate which constitutes a liquid crystal element with appropriate strength, and at the same time, the polarizing plate or polarizing plate is manufactured in a manufacturing process. When it becomes necessary to peel off the laminated plate of the plate and the retardation plate, it can be peeled without damaging the liquid crystal cell such as the glass substrate, and the adhesive remains on the glass substrate. It is an object of the present invention to provide a pressure-sensitive adhesive composition for liquid crystal devices, which is difficult to use.

It is another object of the present invention to provide a liquid crystal device in which a polarizing plate or a laminated plate of a polarizing plate and a retardation film is adhered on a glass substrate with the adhesive composition as described above. .

[0012]

SUMMARY OF THE INVENTION The pressure-sensitive adhesive composition for a liquid crystal device of the present invention comprises an acrylic polymer, an alkoxy group represented by the following formula [ I ] having a hydrocarbon group and an alkoxy group as a functional group. Acrylic polymer 10 comprising a silane compound
0 parts by weight of the alkoxysilane compound was added to 0.0
It is characterized in that it is contained in an amount of 1 to 4 parts by weight.

[Chemical 1] However, in the above formula [ I ], R ¹ is a hydrogen atom or carbon.
It is an alkyl group having 1 to 2 elementary atoms, and R ² is the number of carbon atoms.
3 to 15 aliphatic hydrocarbon group or 6 to 15 carbon atoms
Is an aromatic hydrocarbon group, and R ³ has 1 to 3 carbon atoms.
Represents an alkyl group, n is an integer of 0 to 2, m is 1 to 3
It is an integer and has a relationship of 1 ≦ n + m ≦ 3.

Further, in the liquid crystal device of the present invention, liquid crystal is filled in a gap formed by two substrates in which a polarizing plate or a laminated plate of a polarizing plate and a retardation plate is arranged on the surface of the substrate. In a liquid crystal element, a polarizing plate or a laminated plate of a polarizing plate and a retardation plate has an acrylic polymer, a hydrocarbon group and an alkoxy group as a functional group on the surface of the substrate.
A pressure-sensitive adhesive composition comprising an alkoxysilane compound represented by the above formula [ I ] and containing the alkoxysilane compound in an amount of 0.01 to 4 parts by weight relative to 100 parts by weight of the acrylic polymer. It is characterized by being attached by.

The pressure-sensitive adhesive composition for a liquid crystal device of the present invention has a specific alkoxysilane compound having an unfunctionalized hydrocarbon group, an alkoxy group as a functional group, and no other functional group. The adhesive composition of the present invention contains a substrate and a polarizing plate or a laminated plate of a polarizing plate and a retardation film, and the liquid crystal element is actually used in a liquid crystal element. It is possible to bond with necessary and sufficient adhesive strength required in the environment. Moreover, the adhesive strength does not become excessively high due to heating in the liquid crystal element manufacturing process. Therefore, when adhesion failure occurs in the manufacturing process of the liquid crystal element, the polarizing plate or the laminated plate of the polarizing plate and the retardation plate can be easily peeled from the glass substrate from the substrate. It is difficult for the adhesive to remain.

Further, JP-A-57-195208 discloses an invention of a pressure-sensitive adhesive type polarizing plate having a layer composed of a mixture containing an organosilicon monomer having a functional group.

Here, the silicon monomer having a functional group has an unsaturated group such as a vinyl group, an allyl group or an acryloxy group or an amino group, a glycidyl group or a cyclic glycidyl group in one molecule. In addition, hydrogen atom, halogen atom,
The pressure-sensitive adhesive composition for a liquid crystal device of the present invention is described as having an alkoxy group such as a hydroxy group, a methoxy group and an ethoxy group and having two or more different functional groups in its molecule. Has only an alkoxy group as a functional group and does not have any other functional group, and thus has excellent removability, and a composition containing an organosilicon monomer having another functional group will be described later. As shown in Comparative Example 2 above, the removability is not good.

The pressure-sensitive adhesive composition of the present invention has the characteristic that it can be peeled off in the manufacturing process of a liquid crystal element as described above, but is harsh under high temperature and high humidity conditions. Adhesion such as swelling or peeling to the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is shown even if the liquid crystal element is used under the conditions, even if the liquid crystal element is used under such conditions. Less likely to cause defects.

A liquid crystal device to which a polarizing plate or a laminated plate of a polarizing plate and a retardation plate is attached with the adhesive composition of the present invention is a laminated body of a transparent substrate and a polarizing plate or a polarizing plate and a retardation plate. The adhesion to the plate is good, and the adhered state of the two is stable for a long period of time. Therefore, the liquid crystal device of the present invention can maintain excellent optical characteristics for a long period of time.

[0019]

DETAILED DESCRIPTION OF THE INVENTION The pressure-sensitive adhesive composition for a liquid crystal element and the liquid crystal element of the present invention will be specifically described.

The pressure-sensitive adhesive composition for liquid crystal elements of the present invention comprises
It is composed of an acrylic polymer, which is the main component of the adhesive, and an alkoxysilane compound having a hydrocarbon group and an alkoxy group as a functional group.

The acrylic polymer has a pressure-sensitive adhesive property, and is usually a (co) polymer formed from an acrylic monomer such as (meth) acrylic acid ester or a functional group-containing acrylic monomer. used.

Examples of the (meth) acrylic acid ester used here include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate. , Lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate. It can be used alone or in combination. The acrylic polymer used in the present invention has the repeating unit derived from the (meth) acrylic acid ester in an amount of usually 60 to 99% by weight, preferably 80 to 98% by weight.

Further, examples of the functional group-containing acrylic monomer include acrylic acid, methacrylic acid, β-carboxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, chloro-2- Hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate,
Examples thereof include dimethylaminoethyl (meth) acrylate and glycidyl (meth) acrylate.
It can be used alone or in combination. The acrylic polymer used in the present invention has a repeating unit derived from the above functional group-containing acrylic monomer in an amount of usually 1 to 20% by weight, preferably 2 to 10% by weight.

The acrylic polymer used in the present invention may have a repeating unit derived from a monomer other than the above-mentioned (meth) acrylic acid ester and the functional group-containing acrylic monomer. For example,
Examples thereof include a repeating unit derived from a styrene-based monomer and a repeating unit derived from a vinyl-based monomer.

Specific examples of the styrene-based monomer include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene. Alkyl styrene; halogenated styrene such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene and iodostyrene; and nitrostyrene, acetylstyrene and methoxystyrene.

Examples of vinyl monomers include vinylpyridine, vinylpyrrolidone, vinylcarbazole, divinylbenzene, vinyl acetate and acrylonitrile; conjugated diene monomers such as butadiene, isoprene and chloroprene; halogens such as vinyl chloride and vinyl bromide. Vinyl halide; vinylidene halide such as vinylidene chloride and the like can be mentioned.

These monomers can be used alone or in combination. The repeating unit derived from the above-mentioned other monomer in the acrylic polymer used in the present invention is usually 0 to 20% by weight, preferably 0.
It is contained in an amount of 10 to 10% by weight.

The acrylic polymer used in the present invention is prepared, for example, by introducing the above-mentioned monomers into a reaction solvent and replacing the air in the reaction system with an inert gas such as nitrogen gas, and then reacting the mixture if necessary. It can be produced by heating and stirring to cause a polymerization reaction in the presence of an initiator.

As the reaction solvent used here, an organic solvent is used, and specifically, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as n-hexane, ethyl acetate and butyl acetate. And the like, aliphatic alcohols such as n-propyl alcohol and iso-propyl alcohol, and ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

When a reaction initiator is used, for example, azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide and the like can be used.

The reaction temperature of the above polymerization reaction is usually 50 to
90 ° C, the reaction time is usually 2 to 20 hours, preferably 4
~ 12 hours. In the reaction as described above, the monomer can be added in an amount corresponding to the amount of each repeating unit in the acrylic polymer to be obtained.

The reaction solvent is a total amount of monomers of 100.
It is used in an amount of 50 to 300 parts by weight with respect to parts by weight.
Further, the reaction initiator is usually used in an amount of 0.01 to 10 parts by weight.

By carrying out the reaction as described above, the acrylic polymer used in the present invention is obtained as a solution or a dispersion liquid in which the reaction solvent contains the (co) polymer in an amount of 25 to 70% by weight. In the present invention, after removing the solvent from this dispersion, the obtained acrylic polymer may be blended with other components. However, in the present invention, it is preferable to mix the acrylic polymer and other components in a state of being dispersed in the reaction solvent without removing the reaction solvent obtained as described above. Generally, the acrylic polymer obtained as described above is stably dispersed in the reaction solvent, and by using such a dispersion as it is, the respective components can be uniformly mixed.

The acrylic polymer used in the present invention is usually 100,000 to 15,000,000, preferably 3
It has a weight average molecular weight of 00000-800000. In addition, you may mix | blend other components, such as an inorganic filler, with this acrylic polymer within the range which does not impair the objective of this invention.

The pressure-sensitive adhesive composition for liquid crystal elements of the present invention comprises
It comprises the above acrylic polymer and an alkoxysilane compound having a hydrocarbon group and an alkoxy group which is a functional group.

The alkoxysilane compound used in the present invention has only an alkoxy group as a functional group and does not have any other functional group. The other groups constituting this alkoxysilane compound are hydrocarbon groups having no functionality.

Such an alkoxysilane compound can be represented by the following formula [I].

[0038]

[Chemical 2]

However, in the above formula [I], R ¹ represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R ^1
2 represents a hydrocarbon group having ³ to 15 carbon atoms, R ³ is
It represents an alkyl group having 1 to 3 carbon atoms. This R ¹ may not be present.

R ² may be an aliphatic hydrocarbon group having 3 to 15 carbon atoms or an aromatic hydrocarbon group having 6 to 15 carbon atoms. Then, in the above formula [I], n is an integer of 0 to 2, m is an integer of 1 to 3, and has a relationship of 1 ≦ n + m ≦ 3.

In the above formula [I], when the number of carbon atoms of R ² exceeds 15, the solubility of the alkoxysilane compound in an acrylic polymer may be lowered. Further, if the number of carbon atoms of R ² is less than 3, the releasability at the time of manufacturing the liquid crystal element and the durability under high temperature and high humidity conditions, which are the objects of the present invention, may not be sufficiently exhibited. In particular, an alkoxysilane compound in which the number of carbon atoms of R ² is within the range of 3 to 10 is particularly preferable because it has a good affinity for an acrylic polymer.

To the acrylic polymer which is the adhesive component,
By blending an alkoxysilane compound having a hydrocarbon group and an alkoxy group which is a functional group and having no other functional group as described above, necessary and sufficient adhesive strength can be secured. In particular, in the formula [I], an alkoxysilane compound having an alkoxy group having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms of R ³ forming an alkoxy group is preferable. In this case, R ¹ in the formula [I] is Is absent or is an alkyl group having 1 to 2 carbon atoms, and R ² is preferably an alkyl group or aryl group having 3 to 10 carbon atoms.

Specifically, the pressure-sensitive adhesive composition of the present invention can be used as a substrate, by using an alkoxysilane compound having the above-mentioned hydrocarbon group and an alkoxy group as a functional group.
In particular, the glass substrate and the polarizing plate or the laminated plate of the polarizing plate and the retardation plate can be bonded with an adhesive strength of about 200 to 2000 g / 25 mm as measured by the method specified in JIS described later. Further, the pressure-sensitive adhesive composition of the present invention, the polarizing plate or a laminated plate of the polarizing plate and the retardation plate is processed by adhesion,
Even if the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is adhered to the surface of the glass substrate and then peeled off, the adhesive component does not remain on the surface of the glass substrate, and the adhesive does not remain on the surface of the glass substrate. It is removed together with the laminated plate with the phase difference plate.

Preferred examples of the above-mentioned alkoxysilane compounds are shown below.

[0045]

[Chemical 3]

The pressure-sensitive adhesive composition for liquid crystal elements of the present invention comprises
It is necessary to contain the above alkoxysilane compound in an amount of 0.01 to 4 parts by weight, more preferably 0.0 to 100 parts by weight of the acrylic polymer.
It is contained in an amount of 5 to 2 parts by weight. If the amount of the alkoxysilane compound deviates from the above range, the initial adhesive strength is too low and peeling occurs, and if it deviates from the above range, the adhesive strength after heating becomes too high. If a defect occurs in the manufacturing process and the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is peeled off, the liquid crystal cell may be damaged, or adhesive residue on the substrate surface is likely to occur.

In the adhesive composition of the present invention, the above alkoxysilane compound may be used alone,
You may use it in combination. In the pressure-sensitive adhesive composition for a liquid crystal device of the present invention, since the alkoxysilane compound and the acrylic polymer interact with each other, the acrylic polymer and the alkoxysilane compound are usually separately packaged, stored and transported. It Immediately before use, both are mixed and used in an amount within the above range.

The pressure-sensitive adhesive composition for liquid crystal elements of the present invention comprises
Although the above-mentioned acrylic polymer and alkoxysilane compound are contained as the essential components, other components may be contained if necessary.

Examples of other components that can be incorporated into the pressure-sensitive adhesive composition for liquid crystal elements of the present invention include tackifiers, plasticizers, crosslinking agents and dyes.
As the above-mentioned other components, already known components can be blended alone or in combination.

In the liquid crystal device of the present invention, a polarizing plate or a laminated plate of a polarizing plate and a retardation plate is adhered on a substrate using the pressure sensitive adhesive composition for a liquid crystal device described above. FIG. 1 schematically shows a cross section of the liquid crystal element of the present invention.

As shown in FIG. 1, the liquid crystal element 1 of the present invention.
Has two substrates 2 and 2 and a liquid crystal 3 filled in a gap formed by the two substrates 2 and 2. This substrate is made of glass or transparent synthetic resin.
The thickness of this substrate is usually 0.01 to 2.0 mm. In the present invention, a glass substrate is particularly preferable as this substrate.

Transparent electrodes 4 and 4 are formed on the surfaces of the two substrates 2 and 2 in contact with the liquid crystal material 3. The transparent electrode is usually made of ITO or the like. The thickness of this transparent electrode is typically 100-2000 Angstroms.
A liquid crystal alignment film (not shown) may be further formed on the transparent electrodes 4, 4. This liquid crystal alignment film can be formed by rubbing a polyimide resin.

The substrate on which the transparent electrode and the liquid crystal alignment film are formed on one surface as described above is arranged so that the transparent electrodes 4 face each other and form a constant gap. Transparent electrode 4,
The fixed gap formed between the four is usually formed by using the spacer 5. As the spacer 5, for example, inorganic particles, inorganic fibers, resin particles, or a resin film formed in a predetermined pattern (for example, comb shape) can be used. The spacer may also serve as the liquid crystal alignment film.

The width of the gap thus formed is usually 1
10 to 10 μm. The two transparent substrates arranged with a gap as described above are usually bonded by sealing the periphery 6 with a sealing material. As the sealing material 6, an epoxy resin, a silicone resin, or the like can be used.

The liquid crystal 3 is filled in the gap formed as described above. As the liquid crystal 3 filled here, a Schiff base liquid crystal compound, an azoxy liquid crystal compound,
Examples thereof include benzoic acid ester liquid crystal compounds, cyclohexylcarboxylic acid ester liquid crystal compounds, phenyl liquid crystal compounds, terphenol liquid crystal compounds, cyclohexyl liquid crystal compounds, and pyrimidine liquid crystal compounds. These liquid crystal compounds can be used alone or in combination.

The liquid crystal element has the above-mentioned constitution, and the liquid crystal element of the present invention uses a specific adhesive composition on the outer surface of the above-mentioned substrate to form a polarizing plate or a phase difference with the polarizing plate. Laminated boards 7, 7'with boards are attached.

The polarizing plate used here is, for example, a polyester film, a polyvinyl alcohol resin film,
It can be manufactured by dyeing a resin film such as a polyvinyl butyral resin film with iodine or a dichroic dye, stretching it uniaxially, and laminating a protective film such as a triacetate film from both sides.

The polarizing plate or the laminated plates 7 and 7'of the polarizing plate and the retardation plate are attached to the surface of the substrate 2 as follows.
First, a laminated plate 7 or 7'of a polarizing plate or a polarizing plate and a retardation plate
A polarizing plate or a laminated plate of the polarizing plate and the retardation plate is adhered to the surface of the polarizing plate or the laminated plate of the polarizing plate and the retardation plate by using the pressure-sensitive adhesive composition for liquid crystal element described above. Then, the adhesive layers 8 and 8 are formed. The thickness of the adhesive layers 8, 8 thus formed is usually 10 to 50 μm, preferably 15 to 40 μm. By forming the adhesive layer with the above thickness, the substrate and the polarizing plate, or the substrate and the laminated plate of the polarizing plate and the retardation plate can be bonded with necessary and sufficient adhesive strength. At the same time, the adhesive layers 8 and 8 are transparent, and the optical characteristics of the liquid crystal element are not deteriorated by the adhesive layers.

The polarizing plate on which the adhesive layer 8 is thus formed or the laminated plate of the polarizing plate and the retardation plate is pressure-bonded to the outer surface of the substrate 2. If necessary, heating can be performed during this pressure bonding. By pressure-bonding in this manner, a pressure-sensitive adhesive composition for a liquid crystal device, which is composed of an alkoxysilane compound and an acrylic polymer, and the surface of a substrate and the surface of a polarizing plate (or the surface of a laminated plate composed of a polarizing plate and a retardation plate). Adhesive strength of suitable strength is developed between and. The time required for this pressure bonding is, for example, 10 to 30 at 50 ° C. and 5 atm.
It's about a minute.

As described above, by using the pressure-sensitive adhesive composition for liquid crystal elements of the present invention, the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is adhered to the surface of the substrate with a suitable adhesive force. It becomes difficult for a gap to occur between the substrate and the polarizing plate, or between the substrate and the laminated plate of the polarizing plate and the retardation plate. Further, even if the polarizing plate or the laminated plate of the polarizing plate and the retardation plate is peeled from the glass substrate, the adhesive does not remain on the glass substrate surface, and the glass substrate or the liquid crystal cell is damaged during the peeling. There is nothing to do.

Further, in the liquid crystal element of the present invention, the substrate and the polarizing plate or the laminated plate of the polarizing plate and the retardation plate are stably bonded for a long period of time, so that the substrate and the polarizing plate or the substrate and the polarizing plate are adhered to each other. It is possible to effectively prevent the performance of the liquid crystal element from being deteriorated due to poor adhesion between the retardation plate and the laminated plate.

[0062]

The pressure-sensitive adhesive composition for a liquid crystal device of the present invention contains an acrylic polymer as an adhesive main component and an alkoxysilane compound having a hydrocarbon group and an alkoxy group as a functional group. By using this adhesive, the substrate and the polarizing plate or the laminated plate of the polarizing plate and the retardation plate are bonded with a necessary and sufficient adhesive strength for use in an environment where the liquid crystal element is actually used. be able to.

For example, at 60 ° C. and 90%, peeling occurs when a normal pressure-sensitive adhesive is used, but since the adhesive composition of the present invention contains an alkoxysilane compound, peeling does not occur.

In addition, when this adhesive strength causes a problem in the adhesion in the liquid crystal element manufacturing process, it can be peeled off without leaving the adhesive component on the substrate. Alternatively, the liquid crystal cell is rarely damaged.

As described above, the pressure-sensitive adhesive composition for a liquid crystal device of the present invention is swellable or peeled off when the liquid crystal device is used under high temperature and high humidity conditions although it can be peeled off in the manufacturing process. Is less likely to occur, and by using this adhesive, the liquid crystal element can be used for a long time under severe conditions.

In addition, the liquid crystal element of the present invention has good adhesion between the glass substrate and the polarizing plate or the laminated plate of the polarizing plate and the retardation plate, and the adhesion state of both is stable for a long period of time. Therefore, in the liquid crystal device of the present invention, excellent optical characteristics are maintained for a long period of time.

[0067]

The present invention will be described in more detail below with reference to examples of the present invention, but the present invention should not be construed as limited by these examples.

[0068]

Example 1 25 parts by weight of 2-ethylhexyl acrylate, 43 parts by weight of n-butyl acrylate, 3 parts by weight of styrene, 20 parts by weight of ethyl acrylate, 7 parts by weight of acrylic acid, 2 parts by weight of 2-hydroxyethyl acrylate, acetic acid. 100 parts by weight of ethyl and 0.2 parts by weight of azobisisobutyronitrile were placed in a reactor, the air in the reactor was replaced with nitrogen gas, and the reaction solution was stirred at 63 ° C. in a nitrogen atmosphere. The temperature was raised to 2, and the reaction was performed for 2 hours. Separately, 10 parts by weight of ethyl acetate was added with 0.05 of azobisisobutyronitrile.
A solution in which part by weight was dissolved was prepared. 10 parts by weight of the solution of azobisisobutyronitrile thus prepared was added to 63 parts of
It was added dropwise to the reaction solution heated to 0 ° C over 2 hours.

Further, the temperature of this reaction solution was raised to 72 ° C., and 10 parts by weight of a solution of azobisisobutyronitrile prepared in the same manner as above was added dropwise over 4 hours. 220 parts by weight of an ethyl acetate solution of an acrylic polymer was obtained by operating as described above and polymerizing for a total of 8 hours.
The concentration of the acrylic polymer in this ethyl acetate solution is 45% by weight.

[0070] The reaction mixture 220 parts by weight of the and n- hexyl triethoxysilane 1 part by weight of the formula described above (corresponding to 100 parts by weight of the acrylic polymer) [A], a polyisocyanate compound as a crosslinking agent (trade Name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) and 2 parts by weight were added and well stirred to obtain an adhesive composition of the present invention.

The adhesive composition obtained as described above was applied to a polyester release film and then dried (adhesive composition dry coating thickness 25 μm). Then, the adhesive composition applied on the release film was coated with a thickness of
After transfer onto a 20 mm polarizing plate and aging for 7 days at a temperature of 23 ° C. and a humidity of 65%, the polarizing plate and the glass substrate are held at a temperature of 50 ° C. and a pressure of 5 kg / cm ² for 20 minutes. Glued.

Regarding the adhesive force between the polarizing plate thus adhered and the glass substrate, JIS-Z-0237 and JIS-Z-
According to 0238, the initial adhesive strength (adhesive strength after leaving at 23 ° C. for 1 hour) was measured. Furthermore, the sample prepared in the same manner was left at 80 ° C. for 10 hours, then allowed to cool to 23 ° C., and left at this temperature for 1 hour, and the adhesive strength was measured. The smaller the difference in adhesive strength between the two is, the better the removability is, and it is preferable that the difference in adhesive strength is small. Furthermore, when measuring the above-mentioned adhesive strength, the residual property (adhesive residue) of the adhesive on the surface of the glass substrate was visually observed and evaluated.

Further, 20 samples prepared in the same manner were used.
Cut into 30 cm ² and adhere under the above conditions, 100 ℃
× 500 hours and 60 ° C 90% RH × 500 hours After the standing condition, the occurrence of foaming and peeling was visually observed and evaluated.

The results are shown in Table 1. The liquid crystal device in which the polarizing plate prepared as described above was attached to the surface showed good characteristics.

[0075]

In Example 2 Example 1, wherein instead of being represented by [A] n-hexyl triethoxysilane, the foregoing formula [B]
An adhesive composition of the present invention was obtained in the same manner except that 0.1 part by weight of n-decyltrimethoxysilane represented by

Using the adhesive composition produced as described above, its characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0077]

[Example 3] In Example 1, n- represented by the formula [A]
Instead of hexyltriethoxysilane, except for using 0.5 part by weight of diphenyl dimethoxy silane represented by the formula [C] described above to obtain an adhesive composition to the present invention in the same manner.

Using the adhesive composition produced as described above, its characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0079]

[Example 4] In Example 1, n- represented by the formula [A]
Instead of hexyltriethoxysilane, methylphenyl dimethoxysilane 0.5 represented by the formula [D] described above
An adhesive composition of the present invention was obtained in the same manner except that parts by weight were used.

Using the adhesive composition produced as described above, its characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0081]

Comparative Example 1 An adhesive composition was obtained in the same manner as in Example 1 except that the alkoxysilane compound represented by the formula [A] was not used.

Using the adhesive composition produced as described above, its characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0083]

[Comparative Example 2] In Example 1, n- represented by the formula [A]
Without using hexyl triethoxysilane, equation [E]
An adhesive composition was obtained in the same manner except that 0.2 part by weight of the silane coupling agent represented by

[0084]

[Chemical 4]

Using the adhesive composition produced as described above, its characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0086]

[Table 1]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a liquid crystal element of the present invention.

[Explanation of symbols]

1 ... Liquid crystal element 2 ... Substrate 3 ... Liquid crystal material 4 ... Transparent electrode 5 ... Spacer 6 ... Sealing material 7, 7 '... Polarizing plate Laminated plate with phase difference plate 8 ... Adhesive layer

─────────────────────────────────────────────────── ─── Continued Front Page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09J 133/04-133/14 G02F 1/1335 510-1/13363

Claims (2)

(57) [Claims] 1. An acrylic polymer represented by the following formula [ I ] having a hydrocarbon group and an alkoxy group as a functional group.
A pressure-sensitive adhesive composition for a liquid crystal device, comprising the alkoxysilane compound in an amount of 0.01 to 4 parts by weight with respect to 100 parts by weight of the acrylic polymer. ; [Chemical 1] [ However, in the above formula [ I ], R ¹ is a hydrogen atom or
It is an alkyl group having 1 to 2 carbon atoms, and R ² is a carbon atom.
Aliphatic hydrocarbon group having 3 to 15 carbon atoms or 6 to 1 carbon atoms
5 is an aromatic hydrocarbon group of 5 and R ³ is 1 to 1 carbon atoms.
3 represents an alkyl group, n is an integer of 0 to 2, and m is 1 to 3.
Which is an integer of 1 and has a relationship of 1 ≦ n + m ≦ 3
]]. 2. A liquid crystal device in which a liquid crystal is filled in a gap formed by two substrates in which a polarizing plate or a laminated plate of a polarizing plate and a retardation plate is arranged on the surface of the substrate. on the surface, the laminate of the polarizing plate or the polarizing plate and the retardation plate, the following equation having the alkoxy group and an acrylic polymer, a hydrocarbon group and a functional group
A pressure-sensitive adhesive composition comprising an alkoxysilane compound represented by [ I ] and containing the alkoxysilane compound in an amount of 0.01 to 4 parts by weight based on 100 parts by weight of the acrylic polymer. a liquid crystal element, characterized in that it is attached; embedded image [In the above formula [I], R ¹ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R ² is an aliphatic hydrocarbon group having 3 to 15 carbon atoms or 6 to 1 carbon atoms.
5 is an aromatic hydrocarbon group of 5 and R ³ is 1 to 1 carbon atoms.
3 represents an alkyl group, n is an integer of 0 to 2, and m is 1 to 3.
And has a relationship of 1 ≦ n + m ≦ 3].