JP2002127315A - Molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded article maintaining a gas barrier property, preventing a release between a gas barrier layer and a thermoplastic norbornen resin molded article under a high temperature, and capable of maintaining a high adhesive property. SOLUTION: The molded article is obtained by laminating the gas barrier layer made of a partially saponified polyvinyl acetate on a surface of the molded article made of the thermoplastic norbornen resin.

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]

SUMMARY OF THE INVENTION The present invention provides a molded article comprising a molded article made of a thermoplastic norbornene resin and a gas barrier layer composed of a partially saponified polyvinyl acetate laminated on the surface of the molded article. is there.

[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. Has a weight average molecular weight of 5,000 to 100.
10,000, preferably 8,000 to 200,000. Examples of the thermoplastic resin having a norbornane skeleton that can be used in the present invention include, for example, JP-A-60-168708.
JP, JP-A-62-252406, JP-A-62-252406
-252407, JP-A-2-133413, JP-A-63-145324, JP-A-63-2
Examples of the resin include resins described in JP-A-64626, JP-A-1-240517, and JP-B-57-8815.

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, and 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 100 ° C.
The above is preferable from the viewpoint of heat resistance. The hydrogenation rate of the hydrogenated polymer is 50% or more, preferably 90% or more, more preferably 98% or more, as measured by 60 MHz, 1H-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 generally 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 a partially saponified polyvinyl acetate (PVAc). Here, polyvinyl alcohol (PVA), which is a completely saponified product of polyvinyl acetate, is widely used as a gas barrier layer because it has 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. On the other hand, among the saponified PVAc, those having a low degree of saponification cannot be used as a gas barrier layer because the heat distortion temperature is low and the water absorption is increased.

Therefore, in order to balance the gas barrier performance of the gas barrier layer with the adhesion to the molded article, PVA must be used.
It is desirable to identify the saponified product. The degree is
In the case of PVAc, the degree of saponification is in the range of 90% to 99.8%, preferably 95% to 99.5%. In particular, when the thermoplastic norbornene-based resin does not have a polar group, it is necessary to increase the adhesiveness of the gas barrier layer, so that saponification of PVAc 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.

Such PVAc can be produced by a conventionally known polymerization method, and can be obtained by a method such as a high pressure radical polymerization method or a medium pressure solution polymerization method. The method for saponifying PVAc is not particularly limited, and a normal alkali hydrolysis method can be used. A commercially available partially saponified PVAc may be used. Further, in the present invention, the partially saponified PVAc 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, PVA
As the degree of crystallinity of the gas barrier layer composed of c-partially saponified compound 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 PVAc.

As a method for producing a molded article, a thermoplastic norbornene resin and a partially saponified PVAc are separately charged into a plurality of extruders and coextruded to form a film,
A method of laminating into a fiber or a sheet, supplying a partially saponified PVAc melted by an extruder to a coating apparatus,
A method of coating fibers previously manufactured with a coating nozzle, a method of coating a thermoplastic norbornene-based resin molded article with a PVAc partially saponified solution by a casting method or a coating method, and a method of coating a thermoplastic norbornene-based resin molded article with PV.
A method of laminating a film composed of partially saponified Ac 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. The gas barrier layer is a partially saponified polyvinyl acetate,
A molded article having a saponification degree of 90% to 99.8%, wherein the form is a sheet, a film, a fiber, a lens, or a container.

[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
0 g, 1,2-dimethoxyethane 60 g, cyclohexa
240 g, 1-hexene 9 g, and diethylaluminum
2. A solution of 0.96 mol / l toluene chloride in toluene.
Add 4 ml to the 1 liter autoclave
Was. 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
Of 0.1 mol / l of 1,2-dimethoxy with paraaldehyde
10 ml of cyethane solution was mixed. This mixed solution 4.9
ml was added to the mixture in the autoclave. Dense
After stoppering, 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 partially saponified polyvinyl acetate (PVAc) (degree of saponification: 99 mol)
%) Were co-extruded with separate extruders to obtain a laminate in which a layer made of partially saponified PVAc was laminated on one surface of a thermoplastic norbornene-based resin molded product. When the thickness of this molded product was measured, the layer portion made of a thermoplastic norbornene-based resin was 100 μm, and the layer portion made of a partially saponified PVAc 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 PVAc had a degree of saponification of 99.7 mol%.
This molded product was evaluated in the same manner as in Example 1.
Table 2 shows the evaluation results.

Comparative Example 1 In place of the partially saponified PVAc, the degree of saponification was 100 mol.
1% PVAc completely saponified (polyvinyl alcohol)
A molded article was obtained in the same manner as in Example 1 except that
This molded product was evaluated in the same manner as in Example 1.
Table 1 shows the evaluation results.

[0033]

[Table 1]

As apparent from Table 1, the molded articles of Examples 1 and 2 have excellent gas barrier properties and also excellent film adhesion. On the other hand, a molded article using the polyvinyl alcohol, which is a completely saponified PVAc, in the gas barrier layer (Comparative Example 1) is excellent in gas barrier properties, but significantly inferior in film adhesion.

[0035]

According to the present invention, a molded article made of a thermoplastic norbornene resin is used as a gas barrier layer on a molded article made of a thermoplastic norbornene resin.
It is obtained by laminating partially saponified materials of Ac, 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)

[Claims] 1. A molded product obtained by laminating a gas barrier layer composed of a partially saponified polyvinyl acetate on the surface of a molded product composed of a thermoplastic norbornene resin.