JP3259609B2 - Molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article comprising a molded article made of a thermoplastic norbornene resin and a gas barrier layer having excellent adhesion and low water absorption laminated on the surface of the molded article.

[0002]

2. Description of the Related Art Thermoplastic norbornene resins are used in various applications as excellent optical resins having a high glass transition temperature (high heat resistance), low water absorption and a small photoelastic coefficient. However, among these optical applications, when used as a transparent conductive film of a liquid crystal display,
In order to suppress the deterioration of the enclosed liquid crystal due to oxygen and water vapor, a film substrate having particularly low gas permeability and water vapor permeability is required.

On the other hand, a technique of laminating a gas barrier film on the surface of a resin molded product in order to lower the gas permeability and water vapor permeability of the resin molded product has been known. As such a gas barrier film, resins such as ethylene-vinyl alcohol copolymer (EVOH) and polyvinylidene chloride are known. However, a resin having a high heat deformation temperature, such as a thermoplastic norbornene-based resin, is often used in a high-temperature environment. In this case, a thermoplastic norbornene-based resin molded product in which a gas barrier layer made of the above resin is laminated. When using, the adhesion between the gas barrier layer and the molded article is reduced, and gas or water vapor easily enters between the layers, thereby causing deterioration of the molded article. Also, when used for liquid crystal display applications, there are many problems that cause deterioration of the encapsulated liquid crystal.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a high adhesion can be obtained without delamination between a gas barrier layer and a thermoplastic norbornene resin molded product even at high temperatures, while maintaining the gas barrier properties of the resin. It is an object to provide a molded article that can be maintained.

[0005]

The present invention relates to a thermoplastic norbornene resin (provided that the glass transition temperature is 145 ° C. or lower).
The molded article surface made of excluding resin lower), ethylene -
An object of the present invention is to provide a molded product obtained by laminating a gas barrier layer composed of a partially saponified vinyl acetate copolymer .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermoplastic norbornene resin used in the molded article of the present invention has a norbornane skeleton in its repeating unit. For example, the thermoplastic resin contains a norbornane skeleton represented by the general formulas (I) to (IV).

[0007]

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(In the formula, A, B, C and D represent a hydrogen atom or a monovalent organic group.) The thermoplastic resin having a norbornane skeleton used in the present invention is required to obtain sufficient strength. Having a weight average molecular weight of 5,000 to 1,000,000, preferably 8,000 to 20
It is ten thousand. Examples of the thermoplastic resin having a norbornane skeleton that can be used in the present invention include, for example, JP-A-60-168708 and JP-A-62-25240.
No. 6, Japanese Patent Application Laid-Open No. 62-252407,
-133413, JP-A-63-145324, JP-A-63-264626, JP-A-1-24
No. 0517, Japanese Patent Publication No. 57-8815, and the like.

Specific examples of the thermoplastic norbornene resin include at least one tetracyclododecene derivative represented by the following general formula (V) or an unsaturated cyclic compound copolymerizable with the tetracyclododecene: And a hydrogenated polymer obtained by hydrogenating a polymer obtained by metathesis polymerization.

[0010]

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(Wherein A to D are the same as above.) In the tetracyclododecene derivative represented by the above general formula (V), A, B, C and D each include a polar group, It is preferable from the viewpoint of heat resistance and adhesion to the gas barrier layer. Further, this polar group is-(CH ₂ ) _n COOR
(Where R is a hydrocarbon group having 1 to 20 carbon atoms, and n is 0 to
(Showing an integer of 10) is preferable because the resulting hydrogenated polymer has a high glass transition temperature. In particular, it is preferable that one polar substituent represented by — (CH ₂ ) _n COOR is contained in one molecule of the tetracyclododecene derivative of the general formula (V).

In the above general formula, R has 1 to 20 carbon atoms.
Is preferred in that the greater the number of carbon atoms, the lower the hygroscopicity of the obtained hydrogenated polymer becomes. However, from the viewpoint of the balance with the glass transition temperature of the obtained hydrogenated polymer, the number of carbon atoms is 1 It is preferably a chain alkyl group having 4 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms, particularly preferably a methyl group, an ethyl group or a cyclohexyl group. Further, the tetracyclododecene derivative of the general formula (V) in which a hydrocarbon group having 1 to 10 carbon atoms is simultaneously bonded as a substituent to the carbon atom to which the carboxylic acid ester group is bonded, reduces the hygroscopicity. preferable. In particular, the general formula (V) in which this substituent is a methyl group or an ethyl group
The tetracyclododecene derivative is preferred because of its easy synthesis. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 1 ^7,10 ] dodec-8-ene is preferred.

These tetracyclododecene derivatives or mixtures of unsaturated cyclic compounds copolymerizable therewith are described, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, lower right column, The thermoplastic norbornene resin used in the present invention can be obtained by metathesis polymerization and hydrogenation by the method described in line 6. Further, the above hydrogenated polymer (thermoplastic norbornene resin)
Has a softening temperature of 90 ° C. or higher and a glass transition temperature of 145 ° C.
Exceed is preferred from the viewpoint of heat resistance. The hydrogenation rate of the hydrogenated polymer is at least 50%, preferably at least 90%, more preferably at least 98%, as measured by 60 MHz, ¹ H-NMR. The higher the hydrogenation rate, the better the stability to heat and light.

The hydrogenated polymer used as the thermoplastic resin having a norbornane skeleton (thermoplastic norbornene-based resin) of the present invention is prepared from the viewpoint of preventing the occurrence of defects such as rough skin on the surface of a molded product. The gel content in the polymer is preferably 5% by weight or less, more preferably 1% by weight. The total light transmittance of the thermoplastic norbornene-based resin thus obtained measured by ASTM D1003 is 85% or more, preferably 90%.
Above, more preferably 92% or more.

In addition, the thermoplastic norbornene resin used in the present invention may contain a known antioxidant such as 2,6-di-t-butyl-4-methylphenol and 2,2'-dioxy, if necessary. -3,3'-Di-tert-butyl-5,5'-dimethylphenylmethane, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,1 , 3-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6
-Tris (3,5-di-t-butyl-4-hydroxybenzyl-benzene, stearyl-β- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate,
2,2'-dioxy-3,3'-di-tert-butyl-5,
5'-diethylphenylmethane, 3,9-bis [1,1
-Dimethyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl], 2,4,8,10-tetraoxospiro [5,5]
Undecane, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2 6
-Di-t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite can be added. The amount of these antioxidants to be added is usually 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the thermoplastic norbornene resin. If the amount of the antioxidant is too small, the effect of improving the durability is insufficient, while if it is too large, problems such as bleeding from the molding surface or decreasing the transparency are preferable. Absent.

The thermoplastic norbornene resin used in the present invention may contain, in addition to the above-mentioned antioxidants, an ultraviolet absorber, if necessary, such as pt-butylphenylsalicylate, 2,2. '-Dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone, 2-
(2'-dihydroxy-4'-m-octoxyphenyl) benzotriazole; inorganic filler such as calcium carbonate, carbon fiber, metal oxide; stabilizer, antistatic agent, dye, pigment, flame retardant, impact resistance An elastomer for improvement or the like can be added. In addition, additives such as a lubricant can be added for the purpose of improving workability. Furthermore, when casting the above resin to form a cast film, a leveling agent can be added. As the leveling agent, for example, a fluorine-based nonionic surfactant, a special acrylic resin-based leveling agent, a silicone-based leveling agent, or the like can be used.

Next, the gas barrier layer used in the molded article of the present invention is made of a part of ethylene-vinyl acetate copolymer (EVA).
It is saponified . Here, ethylene-vinyl acetate copolymer
Ethylene-vinyl alcohol copolymer (EVOH), which is a completely saponified body, has been widely used as a gas barrier layer because of its high gas barrier properties, but has poor adhesion to other materials. For this reason, there is a problem in that the gas or water vapor invades between the molded product and the molded product is deteriorated during long-time use at a high temperature, and the gas barrier layer is separated from the molded product. Furthermore, when the molded article of the present invention is used for liquid crystal display applications, the encapsulated liquid crystal may be deteriorated by gas or water vapor that has entered between the gas barrier layer and the thermoplastic norbornene-based molded article. Meanwhile, EVA
Among the saponified products , those having a low saponification degree cannot be used as a gas barrier layer because the heat distortion temperature is low and the water absorption increases.

Therefore, in order to balance the gas barrier performance of the gas barrier layer with the adhesion to the molded product, EVA
It is desirable to specify the degree of saponification of the saponified product . In the case of EVA , the degree varies depending on the content of vinyl acetate units in the copolymer.
Degree of saponification 80% to 99.5%, preferably 90% to 99%
% Range. In particular, when the thermoplastic norbornene-based resin does not have a polar group, it is necessary to increase the adhesion of the gas barrier layer, so that saponification of EVA is suppressed within a range that does not impair moisture resistance and heat resistance. It is preferable to increase the number of vinyl acetate residues. The content of vinyl acetate units in the partially saponified EVA is at least 5%, more preferably at least 10%. When the content of the vinyl acetate unit is less than 5%, the obtained copolymer has a property close to that of ethylene and has poor adhesion to a thermoplastic norbornene-based molded article.

Such an EVA can be produced by a conventionally known polymerization method, and includes a high pressure radical polymerization method,
It can be obtained by a method such as a medium pressure solution polymerization method. Also, the saponification method of EVA is not particularly limited, and a normal alkali hydrolysis method can be used. Alternatively, a commercially available partially saponified EVA may be used. Further, in the present invention, the partially saponified EVA used as the gas barrier layer may be further acetalized.

When the molded article of the present invention is used for optical applications, it is preferable that the transparency of the gas barrier layer is high so as not to impair the transparency. For example, EVA
As the degree of crystallinity of the gas barrier layer made of partially saponified material increases, the gas barrier property also increases, but the transparency is reduced, so that the range of applications for optical applications is limited. The thickness of the gas barrier layer in the molded article of the present invention is preferably 0.5 μm or more, more preferably in the range of 10 to 300 μm in order to sufficiently provide the gas barrier effect.

The form for obtaining the molded article of the present invention is not particularly limited, but the thermoplastic norbornene-based resin molded article and the gas barrier layer can be directly laminated, or the gas barrier layer can be replaced with another polymer layer or an adhesive layer. Can also be laminated with a thermoplastic norbornene-based resin molded product. The gas barrier layer may be used as a single layer, or may have a multilayer structure using partially saponified EVA . In particular, the molded article of the present invention
Is a layer composed of partially saponified EVA as a gas barrier layer
It is suitable for applications where moisture resistance is strictly required.
New

Examples of the method for producing a molded article include a method in which a thermoplastic norbornene resin and a partially saponified EVA are separately charged into a plurality of extruders and co-extruded, and laminated into a film, fiber or sheet. the EVA partially saponified melted in an extruder and fed to the coating apparatus, a method of coating a prefabricated fiber coated nozzle, EVA portion Ke to the thermoplastic norbornene resin molded product
Method for coating a down product solution by a casting method or a coating method, EVA portion thermoplastic norbornene-based resin molded article
For example, a method of laminating a film made of a saponified product via an adhesive layer can be used. Here, the molded article made of the thermoplastic norbornene resin can be formed into a desired molded article by a known molding method, for example, a method such as injection molding, extrusion molding, or compression molding.

The molded article of the present invention can be used for films for liquid crystal displays, optical fibers, lenses for automobile lamps, various lenses such as lenses for movie lights, containers for pharmaceuticals, medical instruments, food packaging materials and the like. Can be used.

A preferred embodiment of the present invention is as follows. A molded article in which the thermoplastic norbornene resin is a hydrogenated polymer. If the gas barrier layer is ethylene-vinyl acetate
Consisting of partially saponified copolymers having a degree of saponification of 8
A molded article, wherein the molded article form is a sheet, a film, a fiber, a lens, or a container, which is 0% to 99.5%.

[0025]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by this. In addition,
In Examples, parts and% are based on weight unless otherwise specified. In addition, various measurements in the examples were performed as follows.

The oxygen gas permeability was measured under the conditions of 20 ° C. and 80% relative humidity according to ASTM D3985. The water vapor permeability was measured under the conditions of 40 ° C. and 90% relative humidity according to JIS Z0208. 1 mm × 1 mm square 10 in the gas barrier layer of the film adhesion molded product
0 pieces were cut with a cutter, and a cellophane tape peeling test was performed, and the adhesion was evaluated according to the following evaluation criteria. ：: The number of peeled eyes is 0 Δ: The number of peeled eyes is 1 to 10 ×: The number of peeled eyes exceeds 10

Reference Example 1 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodeca-3-ene 10
2. A toluene solution of 0 g, 60 g of 1,2-dimethoxyethane, 240 g of cyclohexane, 9 g of 1-hexene, and 0.96 mol / l of diethylaluminum chloride.
4 ml was added to an autoclave having a volume of 1 liter. On the other hand, in another flask, 0.1 kg of tungsten hexachloride was added.
20 ml of a 05 mol / l 1,2-dimethoxyethane solution
And 10 ml of a 0.1 mol / l 1,2-dimethoxyethane solution of paraaldehyde. This mixed solution 4.9
ml was added to the mixture in the autoclave. After sealing, the mixture was heated to 80 ° C. and stirred for 4 hours.

To the obtained polymer solution, a mixed solvent of 2/8 (weight ratio) of 1,2-dimethoxyethane and cyclohexane was added to reduce the polymer / solvent ratio to 1/10 (weight ratio). 20 g of ethanolamine was added and stirred for 10 minutes. To this polymerization solution, 500 g of methanol was added, and 3
The mixture was stirred for 0 minutes and allowed to stand. Except for the upper layer which is separated into two layers,
Methanol was added again, and the mixture was stirred and allowed to stand, and then the upper layer was removed.
The same operation was further repeated twice, and the obtained lower layer was appropriately diluted with cyclohexane and 1,2-dimethoxyethane to obtain a cyclohexane-1,2-dimethoxyethane solution having a polymer concentration of 10%.

To this solution, 20 g of palladium / silica magnesia [manufactured by Nikki Chemical Co., Ltd., palladium amount = 5%]
And a hydrogen pressure of 40 kg / cm ^{2 in} an autoclave.
After reaction at 165 ° C. for 4 hours, the hydrogenation catalyst was removed by filtration to obtain a hydrogenated polymer solution. Further, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4), an antioxidant, was added to this hydrogenated polymer solution.
-Hydroxyphenyl) propionate] was added to the hydrogenated polymer in an amount of 0.1%, and the solvent was removed at 380 ° C under reduced pressure. Next, the molten resin was pelletized by an extruder under an atmosphere of nitrogen, and the weight average molecular weight was 7.0.
× 10 ⁴ , hydrogenation ratio 99.5%, glass transition temperature 168 ° C
Was obtained.

Example 1 The thermoplastic norbornene resin obtained in Reference Example 1 and a partially saponified EVA (ethylene content 35 mol%, saponification degree 9
(5 mol%) were co-extruded with separate extruders to obtain a laminate in which a layer composed of a partially saponified EVA was laminated on one surface of a thermoplastic norbornene-based resin molded product. When the thickness of this molded product was measured, the thickness of the layer portion of the thermoplastic norbornene-based resin was 100 μm, and the thickness of the layer portion of the EVA partially saponified product was 15 μm. This molded article was evaluated for oxygen gas permeability, water vapor permeability, and film adhesion. Table 1 shows the evaluation results.

Example 2 A molded product was obtained in the same manner as in Example 1, except that the partially saponified EVA had an ethylene content of 40 mol% and a saponification degree of 99 mol%. This molded product was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

Comparative Example 1 An ethylene content of 35 m was used in place of the partially saponified EVA.
ol%, a molded product was obtained in the same manner as in Example 1, except that a completely saponified product of EVA (ethylene-vinyl alcohol copolymer) having a saponification degree of 100 mol% was used. This molded product was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.
Shown in

[0032]

[Table 1]

As is clear from Table 1, the molded articles of Examples 1 and 2 have sufficiently low oxygen gas permeability and water vapor permeability, excellent gas barrier properties, and excellent film adhesion. is there. On the other hand, a molded article using the ethylene-vinyl alcohol copolymer which is a completely saponified product of EVA for the gas barrier layer (Comparative Example 1) is excellent in gas barrier properties, but significantly inferior in film adhesion . .

[0034]

The molded article of the present invention is an EV having a gas barrier layer on a molded article made of thermoplastic norbornene resin.
It is obtained by laminating partially saponified A , and has excellent film adhesion between layers while maintaining high gas barrier properties. Therefore, it can be suitably used for applications requiring high transparency, heat resistance, and gas barrier properties at the same time, such as liquid crystal display applications.

Claims (1)

(57) [Claims] Claims: 1. A thermoplastic norbornene-based resin (provided that
Except for resins having a glass transition temperature of 145 ° C or lower) , a part of ethylene-vinyl acetate copolymer
A molded product obtained by laminating a gas barrier layer composed of a saponified material .