JPH06255053A - Thermoplastic resin sheet for molding and molded body - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin sheet that has low adhesiveness in thermoforming and thus corresponds to various molding forms with a wide range of molding temperatures, a good uniformity in the molded item obtained, and a fine sliding property in the molded item, and is not susceptible to flaws at least, one of the layers being amorphous polyolefine in a thermoplastic resin sheet having a plurality of layers. CONSTITUTION:One layer of a thermoplastic sheet having at least two layers is made of amorphous polyolefine of norbornene resin. When the amorphous polyolefine layer is A, and the thermoplastic resin layer to be laminated is made B, a two-layered structure of A/B is available, and a three-layered structure of B/A/B is also available, and when the thermoplastic resin layer except A, B is made C, a multi-layered structure of B/A/C, and C/B/A/B/C are still available, and the amorphous polyolefine layer itself can exist by two layers or more therein. The molding temperature of a molded body for thermoforming a thermoplastic resin sheet is a glass transition temperature or higher of the amorphous polyolefine, or a melting point or glass transition temperature or lower of the thermoplastic resin to be laminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin sheet having excellent moldability and a molded product thereof. In particular, the present invention relates to a thermoplastic resin sheet for molding which is excellent in transparency and moisture resistance and a molded product thereof.

[0002]

2. Description of the Related Art Various attempts have hitherto been made in attempts to thermoform a thermoplastic resin sheet and use it as a container for food or the like. Among them, polyester, polyolefin, polycarbonate, polystyrene, polyvinyl chloride, etc. are actually used. It is used. For example, in the case of polyester, JP-A-47-391 and JP-A-51-38335 are used.
JP-B-62-1909 propose to thermoform unstretched polyethylene terephthalate, the copolymer and the blend. In addition, Japanese Examined Japanese Patent Publication 59-514
No. 07 proposes to use a low orientation polyester sheet for molding.

However, although the polyester sheet is excellent in transparency, it has a poor water vapor barrier property.
It could not be used for packaging medicines that require moisture resistance.

Polyolefin and polyvinyl chloride are relatively excellent in moisture resistance as compared with polyester, but they are still insufficient. For example, in the case of polyvinyl chloride sheets, secondary packaging is carried out, and resin with high resin price is used. It is obliged to stack vinylidene chloride.

[0005] In addition, polypropylene is used as a polyolefin sheet in particular, but in order to impart a water vapor barrier property, the surface thereof is subjected to chlorination treatment, or glass fiber or an inorganic compound which is difficult to pass water vapor is added. In Japanese Patent Publication No. 3-4029, a composite film in which a petroleum resin is mixed with polypropylene is proposed.

[0006]

However, the laminated sheet of polyvinyl chloride and polyvinylidene chloride is very expensive and has a problem that toxic gas is generated during incineration. In addition, each of the polypropylene sheets has a drawback that not only the water vapor barrier property is insufficient, but also the transparency, durability, mechanical properties, and productivity are deteriorated.

Polymers represented by norbornene-based polymers and dicyclopentadiene polymers have been proposed as amorphous polyolefins (see, for example, Japanese Patent Laid-Open Publication No. Sho 6).
0-26024, JP-A-60-168708, JP-A-6
1-115912, JP-A-61-120816, JP-A-63-218727, and JP-A-63-234201), these polymers are very excellent in transparency and moisture resistance, but the polymers are amorphous. When this sheet is subjected to thermoforming, the sheet is apt to be fused to the mold, and the appearance of the molded product is deteriorated, and in severe cases, the sheet may be fused to the mold and molding cannot be performed.

The present invention relates to a thermoplastic resin sheet which is excellent in water vapor barrier property and transparency, has no fusion property with a mold and can be molded in a wide temperature range, and a molded product using the same. .

[0009]

The present invention has the following constitution in order to solve such problems. A thermoplastic resin sheet having at least two layers, at least one layer of which is an amorphous polyolefin, and a thermoplastic resin sheet for molding, which is a glass of amorphous polyolefin. It is a molded product formed by thermoforming at a transition temperature or higher.

Here, the amorphous polyolefin is generally one in which the crystal melting point is difficult to be observed by thermal measurement, and a typical example of the amorphous polyolefin in the present invention is a hydride of dicyclopentadiene, One or more selected from a hydride of a copolymer of dicyclopentadiene and ethylene, a hydride of a copolymer of a reaction product of dicyclopentadiene and ethylene, and a norbornene-based polymer. This norbornene-based resin is preferable as the amorphous polyolefin, but a specific example thereof will be described below.

The norbornene-based resin referred to in the present invention has the general formula (1)

[Chemical 1] (However, in the formula, R ₁ and R ₂ may be the same or different from each other with respect to hydrogen, a hydrocarbon residue or a polar group such as halogen, ester, nitrile and pyridyl.
₁ and R ₂ may form a ring with each other. n is a positive integer and q is 0 or a positive integer. )

And / or general formula (2)

[Chemical 2] (However, in the formula, R ₃ and R ₄ may be the same or different from each other, and may be a hydrogen, a hydrocarbon residue, or a polar group such as halogen, ester, nitrile, and pyridyl.
₃ and R ₄ may form a ring with each other. l and m are positive integers, and p is 0 or a positive integer. The polymer which has a structural unit represented by these can be mentioned.

The polymer having the constitutional unit represented by the general formula (1) includes, for example, norbornene and its alkyl- and / or alkylidene-substituted compounds such as 5-methyl-2-norbornene, 5, and 5 as monomers. 6
-Dicyclopentadiene such as dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene,
2,3-dihydrodicyclopentadiene, alkyl substitution products thereof such as methyl, ethyl, propyl and butyl, and dimethanooctahydronaphthalene substitution products of polar group such as halogen, alkyl and / or alkylidene substitution products thereof, halogen and the like. A substituted polar group of, for example, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5
6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4: 5,8-dimethano-1,4,4a, 5
6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4: 5,8-dimethano-1,4,4a,
5,6,7,8,8a-octahydronaphthalene, 6-
Chloro-1,4: 5,8-dimethano-1,4,4a,
5,6,7,8,8a-octahydronaphthalene, 6-
Cyano-1,4: 5,8-dimethano-1,4,4a,
5,6,7,8,8a-octahydronaphthalene, 6-
Pyridyl-1,4: 5,8-dimethano-1,4,4a,
5,6,7,8,8a-octahydronaphthalene, 6-
Methoxycarbonyl-1,4: 5,8-dimethano-1,
3,4,4a, 5,6,7,8,8a-octahydronaphthalene and other cyclopentadiene trimers, for example,
4,9: 5,8-dimethano-3a, 4,4a, 5,8,
8a, 9,9a-octahydro-1H-benzoindene, 4,11: 5,10: 6,9-trimethano-3a,
4,4a, 5,5a, 6,9,9a, 10,10a, 1
1,1a-dodecahydro-1H-cyclopentaanthracene and the like are used by one kind or two or more kinds, and a ring-opening polymer obtained by polymerization by a known ring-opening polymerization method is hydrogenated by a usual hydrogenation method. It is a polymer produced.

The polymer having the structural unit represented by the general formula (2) is a polymer obtained by addition-copolymerizing ethylene with one or more of the norbornene-based monomers as described above as a monomer by a known method. And / or hydrogenated products thereof, both of which are saturated polymers.

Further, the norbornene-based polymer is prepared by allowing α-olefins such as 1-butene, 1-pentene and 1-hexene to be present as a molecular weight regulator in the production steps of the general formulas (1) and (2). Alternatively, it may be a polymer copolymerized by adding other monomer components such as cycloolefin such as cyclopropene, cyclobutene, cyclopentene, cycloheptene, cyclooctene, 5,6-dihydrocyclopentadiene as a minor component. .

From the viewpoint of heat resistance, these polymers have a glass transition temperature of 70 ° C. or higher, preferably 80 to 15
It is 0 ° C. The molecular weight range is such that the number average molecular weight measured by GPC (gel permeation chromatography) analysis using cyclohexane as a solvent is 10,000 to 10
10,000, preferably 20,000 to 50,000. When the unsaturated bond remaining in the molecular chain is saturated by hydrogenation, the hydrogenation rate is 90% or more, preferably 95% or more, and particularly preferably 99% or more. By being a saturated polymer, weathering resistance and light resistance are improved.

The amorphous polyolefin of the present invention may be used alone or in combination of two or more. or,
You may blend the same kind but different thing in molecular weight.

The amorphous polyolefin of the present invention may be added with an antioxidant, an antistatic agent, a lubricant, a surfactant, an ultraviolet absorber or the like.

The thermoplastic resin sheet of the present invention is characterized by having at least a two-layer structure. That is, when the amorphous polyolefin layer is the A layer and the thermoplastic resin layer laminated thereon is the B layer, a two-layer structure of A / B may be used.
It may be a three-layer structure. When the thermoplastic resin layer other than A and B is the C layer, it may have a structure of B / A / C, or may have a multilayer structure of C / B / A / B / C. Also, the amorphous polyolefin layer itself may be present in two or more layers. Particularly in the case of the thermoplastic resin sheet of the present invention, in order to prevent fusion to the metal mold during thermoforming, B / A / B
A layered structure is preferred.

The lamination ratio is preferably in the range of 1 to 99% of the thickness of the amorphous polyolefin layer with respect to the total thickness of the sheet, but 50 to 99% is more preferable in that the steam barrier property of the sheet can be maintained. preferable.

Examples of the thermoplastic resin laminated on the amorphous polyolefin in the present invention include polyolefin, polyvinyl and polyvinylidene, polyether, polyester, polycarbonate and polyamide.

More specifically, polyolefin: polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, polystyrene, etc. and their copolymers.

Polyvinyl and polyvinyl: polyvinyl chloride, polyvinyl alcohol, polybutyl acrylate,
Polymethylmethacrylate, polyvinylidene chloride, polyvinylidene fluoride, polyacrylonitrile, polyvinyl methyl ketone, etc. and their copolymers

Polyether: polymethylene oxide,
Polyethylene oxide, polyoxacyclobutane, polytetrahydrofuran, polyhexamethylene oxide, polypropylene oxide, poly-p-phenylene oxide, etc. and their copolymers

Polyesters: polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly-ε-caprolactone, polyhexamethylene terephthalate, polyethylene adipate, polyethylene sebacate, poly-1,4-cyclohexylene dimethylene terephthalate, and the like. Polymer

Polyamide: Nylon 6, Nylon 6,
10, nylon 6,6, nylon 6,12, nylon 1
1, nylon 12 etc.

Others: Resins such as polycarbonate, polyphenylene sulfide, polyether sulfone, polysulfone, polyarylate and the like can be mentioned. Furthermore, amorphous polyolefin itself having a high glass transition temperature may be laminated.

In the present invention, the glass transition temperature of the amorphous polyolefin is preferably 70 ° C. or higher. Therefore, the molding temperature of the sheet is desired to be 70 ° C. or higher. Therefore, if the thermoplastic resin to be laminated is a crystalline polymer, its melting point is 80 ° C. in order to prevent the sheet from being fused to the metal during molding.
Or more, preferably 90 ° C. to 240 ° C., and further 10
0 degreeC-230 degreeC is preferable. On the contrary, if the melting point is too high, the molding tension of the sheet increases, resulting in defective molding. Further, when the thermoplastic resin to be laminated has a low crystallinity or is amorphous, the glass transition temperature of the resin is 80 ° C. or higher,
It is preferably 90 ° C. or higher.

Preferred thermoplastic resins in the present invention include polypropylene, polyethylene / propylene copolymer, polystyrene, poly-4-methylpentene-1,
Examples include polybutylene terephthalate and polycarbonate.

In the present invention, an antistatic agent, an organic or inorganic slip agent, a heat stabilizer, and
Additives such as antioxidants, crystal nucleating agents, weathering agents, UV absorbers and pigments can be used according to the purpose.

The thickness of the thermoplastic resin sheet for molding of the present invention should be set according to the application, but is usually 50 to 50.
It is in the range of 2000 μm.

Next, a method for producing the sheet of the present invention will be described.

The amorphous polyolefin is preferably melted by supplying it to an extruder after adjusting the content of low molecular weight components having a molecular weight of less than 500, such as water, gas, volatile matter, and decomposition products, to 0.05% by weight or less. To do. As a method of removing the low molecular weight material, there is a method of preferably using a vacuum dryer at a temperature not higher than the glass transition temperature, or a method of using a vent type twin-screw extruder as an extruder and removing it at the time of melting.

The amorphous polyolefin is preferably co-extruded with another molten thermoplastic resin at the feed block portion or the die portion at the time of melting. When a laminated sheet is obtained, it may be carried out by an extrusion laminating method or a dry laminating method in addition to the coextrusion method.
It is more preferable because it is possible to eliminate the defects of the spinneret that normally occur during extrusion, the defects of scratches during stretching, and the surface defects such as dust adhesion. Particularly in the case of amorphous polyolefin, oxidative decomposition is likely to occur, so that “polymer resin” that is oxidatively decomposed in the polymer is likely to adhere to the vicinity of the lip of the spinneret, which tends to deteriorate the flatness of the spinneret and the film. Can be said to be more effective.

The molten sheet extruded from the die is solidified on a rotating cooling roll. At that time, a method of applying an electrostatic charge to the molten film to bring it into close contact with a cooling roll, a method of polishing between two cooling rolls, a calendar method,
An air knife method, an air chamber method, etc. can be used. Among these, the electrostatic charge adhesion method and the polishing method are preferable from the viewpoint of improving the flatness of the sheet.

The obtained sheet may be used as it is, but may be further stretched, heat-treated or the like, or may be subjected to coating, corona discharge treatment, discharge treatment such as plasma treatment. Further, the sheet of the present invention is embossed,
Surface roughening treatment such as sand mat processing or satin finishing may be performed.

Next, when the molding sheet of the present invention is molded, the molding method is not particularly limited, and various known molding methods such as vacuum molding, pressure molding and plaque assist molding can be used.

The molded product obtained by thermoforming the sheet of the present invention has a molding temperature of not less than the glass transition temperature of the amorphous polyolefin, preferably not less than the glass transition temperature of the amorphous polyolefin + 5 ° C., and is a laminated thermoplastic resin. It is preferably below the melting point or glass transition temperature. If the molding temperature is too low, molding will be defective and problems such as cracks will occur. On the other hand, if the molding temperature is too high, the transparency may be reduced due to adhesion or uneven thickness may occur.

Since the sheet of the present invention is excellent in thermoformability and heat resistance, it can be applied to various forming methods such as vacuum forming, pressure forming and plaque assist forming. Particularly, it is preferable for PTP molding which requires continuous moldability.

[0040]

[Method of evaluating physical properties]

(1) Water vapor transmission rate According to JIS-Z-0208, it is a value measured at 40 ° C. and 90% RH and expressed in g / m ² · day / 250 μm unit.

(2) 100 μm converted haze (H10
0) Measured according to JIS-K-6714 and determined by the following formula.

H100 (%) = H × 100 / d However, H is the measured value of haze (%), and d is the sheet thickness (μm) of the haze measurement part.

(3) Melting point (Tm), glass transition temperature (T
g), cold crystallization temperature (Tcc) Determined using a differential scanning calorimeter DSC2 (manufactured by Perkin Elmer).

The measurement was carried out by melting and holding 10 mg of the sample under a nitrogen stream at 280 ° C. for 5 minutes, and then cooling with liquid nitrogen.

When the sample thus obtained was heated at a heating rate of 10 ° C./min, the change in specific heat due to the transition from the glass state to the rubber state was read, and this temperature was determined as the glass transition temperature. (Tg). The exothermic peak temperature associated with crystallization was defined as the cold crystallization temperature (Tcc), and the endothermic peak temperature associated with crystal melting was defined as the melting point (Tm).

(4) Moldability Molding was carried out using a PTP molding machine manufactured by CKD. The moldability was judged by rank A: uniform molding without uneven thickness is possible Rank B: moldable with uneven thickness Rank C: mold cannot be formed due to mold blocking or cracking.

The transparency of the pocket portion after molding was evaluated by the following ranks.

Rank A: Good transparency Rank B: Poor transparency but practically usable Rank C: Remarkably poor transparency and cannot be used.

[0049]

EXAMPLES Examples will be shown below to facilitate understanding of the effects of the present invention.

Example 1 As an amorphous polyolefin, Mitsui Petrochemical Industry Co., Ltd.
"Apel" APL6509 (glass transition temperature 80 ℃)
Was used. In addition, polystyrene (“Stylon” 666, manufactured by Asahi Kasei Corporation, glass transition temperature 105 ° C.) was used as the laminated polymer. The amorphous polyolefin was dried at 65 ° C. and the polystyrene at 85 ° C. in a vacuum dryer for about 10 hours, respectively, and immediately put into separate extruders and melted. Each molten polymer is
Polystyrene / amorphous polyolefin / polystyrene in a known composite feed adapter (stacking ratio 5/90 /
After uniformly laminating 3 layers of 5), co-extruded from a T-type die, and air-knife method, it was brought into close contact with a mirror surface chrome-plating roll having a surface temperature of 70 ° C. to be cooled and solidified to have a thickness of 250 μm.
Got a sheet of.

Example 2 As an amorphous polyolefin, "Z" manufactured by Nippon Zeon Co., Ltd. was used.
EONEX "TD-001 (glass transition temperature 104 ° C)
Ethylene / propylene copolymer (FL-421 manufactured by Sumitomo Chemical Co., Ltd., melting point 130)
C) was used. 80 for amorphous polyolefins
After preliminary drying for about 12 hours in a hot air oven at ℃, each pellet was put into a separate extruder and melted. The polymer was laminated in three layers (ethylene / propylene copolymer in the outer layer and amorphous polyolefin in the inner layer (lamination ratio: 5/90/5)) to obtain a sheet having a thickness of 250 μm in the same manner as in Example 1.

Example 3 As an amorphous polyolefin, Mitsui Petrochemical Industry Co., Ltd.
"Apel" APL6509 (glass transition temperature 80 ℃)
Was used. Polypropylene (EA130-1, Showa Denko KK, melting point 165 ° C.) was used as the laminated polymer. The amorphous polyolefin was dried in the same manner as in Example 1, and then each pellet was put into a separate extruder and melted. The polymer was laminated in three layers with polypropylene in the outer layer and amorphous polyolefin in the inner layer (lamination ratio 5/90/5), and the thickness was 250 μm as in Example 1.
m sheets were obtained.

Comparative Example 1 Amorphous polyolefin "APEL" APL6509 manufactured by Mitsui Petrochemical Co., Ltd. was extruded in a single layer to give a thickness of 250.
A sheet of μm was obtained.

Comparative Example 2 Amorphous polyolefin "ZE" manufactured by Nippon Zeon Co., Ltd.
ONEX "TD-001 is extruded in a single layer, thickness 250μ
m sheets were obtained.

Comparative Example 3 The same polypropylene as in Example 3 was used, and the thickness was 250 μm.
m sheets were obtained.

[0056]

[Table 1] In Comparative Example 3, the moldability and transparency had no practical problems, but the water vapor barrier property was insufficient. On the other hand, in Comparative Examples 1 and 2, the water vapor barrier property was excellent, but the moldability was poor, and the transparency was slightly lowered due to the effect of adhesion to the mold.

In Examples 1 to 3, water vapor barrier properties,
It was excellent in both moldability and transparency and was useful as a PTP molded product.

[0058]

EFFECTS OF THE INVENTION A sheet obtained by laminating a thermoplastic resin on an amorphous polyolefin and a molded product thereof have the following effects.

(1) Adhesiveness at the time of thermoforming is low and various molding methods can be applied.

(2) The molding temperature range is wide, and the uniformity of the obtained molded product is excellent.

(3) The slipperiness of the molded product is excellent and scratches are unlikely to occur.

Claims (6)

[Claims] 1. A thermoplastic resin sheet having at least two layers, wherein at least one layer is an amorphous polyolefin. 2. The thermoplastic resin sheet for molding according to claim 1, wherein a thermoplastic resin layer is laminated on at least one surface of the amorphous polyolefin layer. 3. The thermoplastic resin sheet for molding according to claim 1, wherein the amorphous polyolefin is a norbornene-based resin. 4. The thermoplastic resin for molding according to claim 1, wherein the thermoplastic resin laminated with the amorphous polyolefin is a crystalline polymer having a melting point of 80 ° C. or higher. Sheet. 5. The molding thermoplastic resin sheet according to claim 1, wherein the thermoplastic resin laminated with the amorphous polyolefin has a glass transition temperature of 70 ° C. or higher. . 6. A molded product obtained by thermoforming the thermoplastic resin sheet for molding according to claim 1 at a temperature not lower than the glass transition temperature of the amorphous polyolefin.