JPH0987404A - Molding - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To maintain a gas barrier property, and to prevent a peeling between a gas barrier layer and a thermoplastic norbornene-based resin molded product even at a high temperature and to maintain a high adhesiveness. To provide. SOLUTION: A partially saponified product of polyvinyl acetate and / or polyvinyl acetate is formed on the surface of a molded article made of a thermoplastic norbornene resin.
Alternatively, a molded article obtained by laminating a gas barrier layer made of a partially saponified ethylene-vinyl acetate copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded product made of a thermoplastic norbornene-based resin, on the surface of which a gas barrier layer excellent in adhesion and capable of suppressing water absorption is laminated.

[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 low gas permeability and water vapor permeability is particularly required.

On the other hand, conventionally, there has been known a technique of laminating a gas barrier film on the surface of a resin molded article in order to reduce the gas permeability and the water vapor permeability of the molded article. 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 thermal deformation temperature such as a thermoplastic norbornene resin is often used in a high temperature environment. In that case, a thermoplastic norbornene resin molded product obtained by laminating a gas barrier layer made of the above resin is used. When the above is used, the adhesion between the gas barrier layer and the molded article is lowered, and gas and water vapor easily enter between the layers, which causes deterioration of the molded article. In addition, when used for liquid crystal display applications, there are many problems that cause deterioration of the enclosed liquid crystal.

[0004]

DISCLOSURE OF THE INVENTION According to the present invention, while maintaining the gas barrier property of the above resin, peeling does not occur between the gas barrier layer and the thermoplastic norbornene-based resin molded product even at high temperature, and high adhesiveness is obtained. The object is to provide a molded product that can be maintained.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, a gas barrier comprising a partially saponified product of polyvinyl acetate and / or a partially saponified product of an ethylene-vinyl acetate copolymer is formed on the surface of a molded article composed of a thermoplastic norbornene resin. The present invention provides a molded article formed by stacking layers.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION 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 includes a norbornane skeleton represented by any of 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 have sufficient strength. , Its weight average molecular weight is 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-A-62-252406, JP-A-62-252406
-252407, JP-A-2-133413, JP-A-63-145324, JP-A-63-2.
Resins described in JP-B No. 64626, JP-A No. 1-240517, JP-B No. 57-8815 and the like can be mentioned.

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

[0010]

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(In the formula, A to D are the same as above.) In the tetracyclododecene derivative represented by the general formula (V), it is possible that A, B, C and D contain a polar group.
It is preferable in terms of heat resistance and adhesion to the gas barrier layer. Further, the polar group - (CH _{2) n} COOR (where
It is preferable that R is a hydrocarbon group having 1 to 20 carbon atoms and n is a group represented by 0 to 10) because the hydrogenated polymer obtained has a high glass transition temperature. . In particular, the - (CH ₂₎ a polar substituent represented by _n COOR is one is preferably contained per molecule of the tetracyclododecene derivatives of general formula (V).

In the above general formula, R has 1 to 20 carbon atoms.
However, it is preferable that the larger the number of carbon atoms, the lower the hygroscopicity of the hydrogenated polymer obtained, but the number of carbon atoms is 1 in terms of the balance with the glass transition temperature of the hydrogenated polymer obtained. It is preferably a chain alkyl group having 4 to 4 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. Furthermore, since 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 hygroscopicity. preferable. In particular, the general formula (V) in which this substituent is a methyl group or an ethyl group
The tetracyclododecene derivative of is preferable because of its easy synthesis. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 1 ^7,10] dodeca-8-ene are preferred.

These tetracyclododecene derivatives or a mixture of unsaturated cyclic compounds copolymerizable therewith are disclosed, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, right lower column. The thermoplastic norbornene-based resin used in the present invention can be obtained by metathesis polymerization and hydrogenation by the method described in line 6. Further, the hydrogenated polymer (thermoplastic norbornene-based resin)
, Softening temperature above 90 ℃, glass transition temperature 100 ℃
The above is preferable in terms 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,
Excellent stability against heat and light.

The hydrogenated polymer used as the thermoplastic resin having a norbornane skeleton (thermoplastic norbornene-based resin) of the present invention is a hydrogenated polymer from the viewpoint of preventing the occurrence of defects such as skin roughness 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 thus obtained thermoplastic norbornene-based resin measured by ASTM D1003 is 85% or more, preferably 90%.
Or more, and more preferably 92% or more.

In addition to the above, the thermoplastic norbornene-based resin used in the present invention may optionally contain known antioxidants such as 2,6-di-t-butyl-4-methylphenol and 2,2'-dioxy. -3,3'-di-t-butyl-5,5'-dimethylphenylmethane, tetrakis [methylene-3- (3,5-di-t-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-t-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) octylphosphite can be added. The amount of these antioxidants 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. When the amount of the antioxidant used is too small, the effect of improving the durability is insufficient, while when it is too large, problems such as bleeding from the molding surface and a decrease in transparency occur. Absent.

In the thermoplastic norbornene resin used in the present invention, in addition to the above-mentioned antioxidant, if necessary, an ultraviolet absorber such as pt-butylphenyl salicylate, 2,2 is used. ′ -Dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone, 2-
(2'-dihydroxy-4'-m-octoxyphenyl) benzotriazole; inorganic fillers such as calcium carbonate, carbon fiber, metal oxides; stabilizers, antistatic agents, dyes, pigments, flame retardants, impact resistance Improving elastomers and the like can be added. Further, additives such as a lubricant may be added for the purpose of improving processability. 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, etc. can be used.

Next, the gas barrier layer used in the molded article of the present invention is a partially saponified product of polyvinyl acetate (PVAc) and / or a partially saponified product of ethylene-vinyl acetate copolymer (EVA). Here, polyvinyl alcohol (PVA), which is a completely saponified product of polyvinyl acetate, and ethylene-vinyl alcohol copolymer (EVOH), which is a completely saponified product of ethylene-vinyl acetate copolymer, have high gas barrier properties. Widely used as a gas barrier layer, but poor in adhesion to other materials. For this reason, there is a problem that a gas or water vapor penetrates into the molded product to deteriorate the molded product and the gas barrier layer peels off from the molded product during long-term use at high temperature. Furthermore, when the molded article of the present invention is used for liquid crystal display applications,
Gas or water vapor that has entered between the gas barrier layer and the thermoplastic norbornene-based molded product may deteriorate the enclosed liquid crystal. On the other hand, among PVAc saponified products and EVA 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 rate increases.

Therefore, in order to balance the gas barrier performance of the gas barrier layer and the adhesion to the molded product, PVA
It is desirable to specify the degree of saponification of saponified c or EVA. The degree of saponification of PVAc is 90% to 99.8%, preferably 95% to 99.5%.
Range. In the case of EVA, the saponification degree is 80% to 99.5%, preferably 90% to 99%, per vinyl acetate unit, although it depends on the content of vinyl acetate units in the copolymer. . 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 saponification of PVAc or EVA should be performed within the range that does not impair the moisture resistance and heat resistance. It is preferable to suppress and increase the vinyl acetate residue.
The content of vinyl acetate units in the partially saponified EVA is 5% or more, more preferably 10% or more. When the content of the vinyl acetate unit is less than 5%, the copolymer obtained has a property close to that of ethylene, resulting in poor adhesion to a thermoplastic norbornene-based molded product.

Such PVAc and EVA 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 saponification method of PVAc or EVA is not particularly limited, and a usual alkali hydrolysis method can be used. In addition, commercially available PVAc and EVA
Alternatively, a partially saponified product may be used. Further, in the present invention, the PVAc partially saponified product or EVA partially saponified product used as the gas barrier layer may be further acetalized.

When the molded article of the present invention is used for optical applications, the transparency of the gas barrier layer is preferably high in order not to impair its transparency as much as possible. For example, PVA
As the degree of crystallinity of the gas barrier layer made of c partially saponified material or EVA partially saponified material becomes higher, the gas barrier property becomes higher, but the transparency lowers, so that the range of use as an optical use becomes limited. The thickness of the gas barrier layer in the molded article of the present invention is 0.5 μm or more, more preferably 10 to 30 in order to sufficiently exert the gas barrier effect.
It is preferably in the range of 0 μm.

The form for obtaining the molded product of the present invention is not particularly limited, but the thermoplastic norbornene-based resin molded product and the gas barrier layer may be directly laminated, or the gas barrier layer may be another polymer layer or an adhesive layer. It can also be laminated with a thermoplastic norbornene-based resin molded product via the above. The gas barrier layer may be used as a single layer or may have a multi-layer structure using both a PVAc partially saponified product and an EVA partially saponified product. In particular, when the molded article of the present invention is used for applications where moisture resistance is strictly required, EVA is used as a gas barrier layer.
It preferably contains a layer of partially saponified material.

As a method for producing a molded article, a thermoplastic norbornene resin and a PVAc partially saponified product or EV are used.
A partial saponified product is separately charged into a plurality of extruders and coextruded to form a film, a fiber or a sheet, and a PVAc partial saponified product or EVA partial saponified product melted by the extruder is coated. To a pre-manufactured fiber by a coating nozzle, a method for coating a PVAc partially saponified or EVA partially saponified solution on a thermoplastic norbornene-based resin molded product by a casting method or a coating method, and a thermoplastic norbornene-based resin. Partially saponified PVAc or EVA for resin molding
A method of laminating a film made of a partially saponified product via an adhesive layer can be used. Here, the molded article made of the thermoplastic norbornene resin is a known molding method,
For example, a desired molded product can be obtained by a method such as injection molding, extrusion molding or compression molding.

The molded articles of the present invention can be used as liquid crystal display films, 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.

The preferred embodiment of the present invention is as follows. A molded product in which the thermoplastic norbornene-based resin is a hydrogenated polymer. When the gas barrier layer is a partially saponified product of polyvinyl acetate, its saponification degree is 90% to 99.8%, and when it is a partially saponified product of an ethylene-vinyl acetate copolymer, its saponification degree is 80% to 99%. Molded product in which the form is a sheet, film, fiber, lens, or 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. The various measurements in the examples were carried out as follows.

Oxygen gas permeability According to ASTM D3985, measurement was carried out under the conditions of 20 ° C. and 80% relative humidity. Water vapor permeability According to JIS Z0208, it was measured under the conditions of 40 ° C. and 90% relative humidity. 1 mm x 1 mm grid 10 on the gas barrier layer of the film-adhesive molded product
Zero pieces were cut with a cutter, 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-en 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 were mixed. 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.

A mixed solvent of 1/8 (weight ratio) of 1,2-dimethoxyethane and cyclohexane was added to the obtained polymer solution to make the polymer / solvent 1/10 (weight ratio), and then tri 20 g of ethanolamine was added and stirred for 10 minutes. To this polymerization solution, add 500 g of methanol and
Stir for 0 minutes and let stand. Except for the upper layer, which is separated into two layers,
Methanol was added again, and the mixture was stirred and left standing, and then the upper layer was removed.
The same operation was 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%.

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

Example 1 Thermoplastic norbornene-based resin obtained in Reference Example 1 and partially saponified EVA (ethylene content: 35 mol%, saponification degree: 9)
5 mol%) was co-extruded by separate extruders to obtain a laminate in which a layer made of EVA partially saponified product 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 the thermoplastic norbornene-based resin was 100 μm, and the layer portion made of the partially saponified EVA was 15 μm. This molded product was evaluated for oxygen gas permeability, water vapor permeability, and film adhesion. Table 1 shows the evaluation results.

Example 2 A molded article was obtained in the same manner as in Example 1 except that the EVA partially saponified product 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 Instead of the partially saponified EVA, the ethylene content was 35 m.
A molded article was obtained in the same manner as in Example 1 except that the completely saponified EVA (ethylene-vinyl alcohol copolymer) having an ol% and 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

[0033]

[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, the molded product (Comparative Example 1) using the ethylene-vinyl alcohol copolymer, which is a completely saponified product of EVA, in the gas barrier layer has excellent gas barrier properties, but is significantly inferior in film adhesion. .

Example 3 Instead of EVA partially saponified product, polyvinyl acetate (PV
A molded article was obtained in the same manner as in Example 1 except that Ac) partially saponified product (saponification degree: 99 mol%) was used. This molded product was evaluated for oxygen gas permeability, water vapor permeability, and film adhesion. Table 2 shows the evaluation results.

Example 4 A molded article was obtained in the same manner as in Example 1 except that the partially saponified PVAc material had a saponification degree 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 2 Instead of the PVAc partially saponified product, the saponification degree was 100 mo.
1% fully saponified PVAc (polyvinyl alcohol)
A molded product was obtained in the same manner as in Example 1 except that was used.
This molded product was evaluated in the same manner as in Example 1.
Table 2 shows the evaluation results.

[0038]

[Table 2]

As is clear from Table 2, the molded articles of Examples 3 and 4 are excellent in gas barrier property and also in film adhesion. On the other hand, the molded product (Comparative Example 2) using polyvinyl alcohol, which is a completely saponified product of PVAc, in the gas barrier layer is excellent in gas barrier property, but largely inferior in film adhesion.

[0040]

EFFECTS OF THE INVENTION The molded product of the present invention comprises a molded product made of a thermoplastic norbornene resin and a PV as a gas barrier layer.
It is a laminate of partially saponified Ac and / or partially saponified EVA, and has excellent film adhesion between layers while maintaining a high gas barrier property. Therefore, it can be suitably used for applications such as liquid crystal display applications where high transparency, heat resistance and gas barrier properties are required at the same time.

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Claims (1)

[Claims] 1. A partially saponified product of polyvinyl acetate and / or polyvinyl acetate on the surface of a molded article made of a thermoplastic norbornene resin.
Alternatively, a molded article obtained by laminating a gas barrier layer made of a partially saponified ethylene-vinyl acetate copolymer.