JP2002348421A - Polypropylene resin composition and transparent sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin composition capable of providing a transparent sheet having a beautiful appearance and excellent in practical properties such as transparency, impact resistance, heat resistance and rigidity and sheet moldability, and also excellent in thermoformability of the sheet and the transparency after the thermoforming, and to provide a transparent sheet using the same and a multilayer transparent sheet using the transparent sheet for at least one layer. SOLUTION: The polypropylene resin composition comprises 100 pts.wt. of a resin component consisting of 60-99 pts.wt. of a polypropylene (A) and 1-40 pts.wt. of a polypropylene (B), each having properties described below, and 0.05-1.0 pts.wt. of a crystal nucleating agent containing a cyclic organic phosphate basic polyvalent metal salt. The polypropylene (A) is a propylene homopolymer or a propylene-α-olefin (including ethylene) random copolymer having a crystalline melting point (TmA) in the range of 150-170 deg.C, and the polypropylene (B) is a propylene-α-olefin (including ethylene) random copolymer having a crystalline melting point (TmB) lower than the crystalline melting point (TmA) of the polypropylene (A) by 5-50 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polypropylene resin composition and a transparent sheet using the same. More specifically, it is excellent in transparency, excellent in impact resistance, heat resistance and rigidity, it can finish the appearance beautifully without generating dirt or fogging of the take-off cooling roll during sheet forming, The present invention also relates to a polypropylene-based resin composition which provides a transparent sheet which does not lose excellent transparency even after thermoforming, and a transparent sheet using the same.

[0002]

2. Description of the Related Art A transparent sheet made of a polypropylene resin has excellent mechanical and thermal properties and excellent packaging suitability, and is therefore widely used as various packaging materials and decoration materials. Examples of the polypropylene include a propylene homopolymer, a binary or multi-component copolymer of propylene and another α-olefin (including ethylene, the same applies hereinafter),
A propylene-ethylene block copolymer composed of a propylene homopolymer portion and a propylene / ethylene copolymer portion is used, and is used in the above-mentioned applications suitable for the characteristics of each polymer.

However, when conventionally known polypropylene is processed into a transparent sheet, transparency is inferior to other materials such as vinyl chloride and polystyrene, and thermoforming when the sheet is subjected to secondary processing into a tray or the like. There was a drawback that the use was limited due to insufficient properties. Further, the sheet was insufficient in the balance between impact resistance, heat resistance and rigidity.

When a nucleating agent typified by a polyhydric alcohol derivative such as dibenzylidene sorbitol is added to improve transparency, a sublimate of the nucleating agent precipitates on a take-off cooling roll or the like during sheet formation. However, there is also a drawback that stains and fogging of the take-off cooling roll and the like are caused, and the precipitated crystal nucleating agent is transferred to the sheet to impair the appearance of the sheet or to contaminate the sheet.

Specifically, a transparent sheet using a propylene homopolymer is excellent in heat resistance and rigidity, but inferior in transparency and impact resistance, and is a binary random copolymer of propylene and another α-olefin. Alternatively, a transparent sheet using a multi-component random copolymer improves transparency and impact resistance, but is inferior in heat resistance and rigidity.

Further, a transparent sheet using a propylene-α-olefin random copolymer having a melt tension exceeding a certain value is excellent in thermoformability of the sheet, but inferior in transparency, and after thermoforming. There is a disadvantage that the transparency is further reduced.

As described above, it is impossible to obtain a transparent sheet having the above-mentioned physical properties with the conventional polypropylene.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent sheet which can satisfy all of transparency, impact resistance, heat resistance and rigidity in a practical sense. Further, such a transparent sheet can be provided, and the sheet appearance can be beautifully finished without causing dirt or fogging of a take-off cooling roll or the like due to a sublimate of a crystal nucleating agent during sheet forming. Another object of the present invention is to provide a polypropylene-based resin composition excellent in thermoformability of a sheet.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems.
A resin composition comprising a resin component consisting of polypropylene (B) having a crystal melting point in the range of 〜50 ° C. lower and a cyclic organic phosphate basic polyvalent metal salt as a crystal nucleating agent, preferably an alkali metal The present inventors have found that a transparent sheet having desired performance can be obtained by molding a resin composition containing a salt, thereby completing the present invention.

A first aspect of the present invention is that a resin component consisting of 60 to 99 parts by weight of a polypropylene (A) having the following properties and 1 to 40 parts by weight of a polypropylene (B) has a cyclic organic phosphate basic polysaccharide. It is composed of a polypropylene-based resin composition in which a crystal nucleating agent containing a valent metal salt is added in an amount of 0.05 to 1.0 part by weight based on 100 parts by weight of the resin component. Polypropylene (A): Crystal melting point (TmA) is 150-
A propylene homopolymer or a propylene-α-olefin random copolymer in the range of 170 ° C. Polypropylene (B): a propylene-α-olefin random copolymer having a crystalline melting point (TmB) lower by 5 to 50 ° C. than the crystalline melting point (TmA) of polypropylene (A).

In a preferred embodiment of the present invention, the polypropylene (A) has a melt flow rate of 0.1 to 10.0 g / mi.
This is the case for n. Another preferred embodiment of the present invention is a case where the polypropylene (A) has a melt tension of 0.1 to 15.0 cN. Another preferred embodiment of the present invention is the case where the crystalline melting point of polypropylene (A) is 155 to 165 ° C. In another preferred embodiment of the present invention, the polypropylene (B) has a melt flow rate of 0.1 to 10.0 g / mi.
n is the case of a propylene-α-olefin random copolymer.

Another preferred embodiment of the present invention is the case where the polypropylene (B) is a propylene-α-olefin random copolymer having a melt tension of 0.1 to 10.0 cN. Another preferred embodiment of the present invention is the case where the polypropylene (B) has a crystal melting point of 130 to 150 ° C. Another preferred embodiment of the present invention is a case where the nucleating agent is a nucleating agent containing a cyclic organic phosphate basic polyvalent metal salt and an alkali metal compound. The second aspect of the present invention is a transparent sheet comprising the above-mentioned polypropylene-based resin composition.
A third aspect of the present invention is a multilayer transparent sheet having at least one transparent sheet.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene (A) used in the polypropylene resin composition of the present invention is a propylene homopolymer or a propylene copolymer obtained by random copolymerizing propylene with one or more α-olefins other than propylene. α-olefin random copolymer, 150 to
It has a crystalline melting point (TmA) in the region of 170 ° C, preferably in the region of 155 to 165 ° C. Crystal melting point is 1
If the temperature is lower than 50 ° C., the obtained sheet tends to have insufficient rigidity, which is not preferable.

The crystal melting point of the polypropylene (A) affects properties such as impact resistance, heat resistance, rigidity and transparency of the obtained sheet. The crystal melting point decreases as the proportion of α-olefin other than propylene in the copolymer increases,
The resulting sheet has improved impact resistance and transparency, but has reduced heat resistance and rigidity. Conversely, the lower the proportion of α-olefins other than propylene in the copolymer, the higher the crystal melting point and the higher the heat resistance and rigidity of the sheet, but the lower the impact resistance and transparency.

[0015] The melt flow rate of the polypropylene (A) is preferably 0.1 to 10.0 g / 10 min, more preferably 0.1 to 4.0 g / 10 min. The melt tension of the polypropylene (A) is preferably 0.1 to 15.
0 cN, more preferably 0.5 to 5.0 cN. If the melt flow rate is less than 0.1 g / 10 min and the melt tension is greater than 15.0 cN, the transparency of the obtained sheet tends to decrease, and the melt flow rate becomes 10.0.
This is because if the melt tension is higher than g / 10 min and the melt tension is lower than 0.1 cN, the resulting sheet may have poor thermoformability during secondary processing.

Further, the polypropylene (A) has a crystal melting point of 155 to 165 ° C. and a melt flow rate of 0.1 to 4.1.
A particularly preferred embodiment is a propylene-ethylene random copolymer having a melt tension of 0 g / 10 min and a melt tension in the range of 0.5 to 5.0 cN. Crystal melting point is 165 ° C or less, melt flow rate is 0.1g / 10min or more,
When the melt tension is 5.0 cN or less, the region is particularly excellent in transparency and impact resistance.

Further, the crystal melting point is 155 ° C. or more, the melt flow rate is 4.0 g / 10 min or less, and the melt tension is 0.5.
When it is 5 cN or more, it is a region where rigidity, heat resistance and thermoformability are particularly excellent. Therefore, the above-mentioned range which is a range included in both the above-mentioned regions is particularly preferable.

The polypropylene (B) used in the polypropylene resin composition of the present invention comprises propylene and other α
-A propylene-α-olefin random copolymer obtained by random copolymerization with one or more olefins. The crystal melting point (TmB) is a region lower than the crystal melting point (TmA) of the polypropylene (A) by 5 to 50C, preferably 15 to 25C. Crystal melting point (TmB) of propylene-α-olefin random copolymer (B)
If the difference between the crystalline melting point (TmA) of the polypropylene and the polypropylene (A) is too large or too small, the balance of physical properties such as impact resistance, heat resistance, rigidity and transparency of the obtained sheet is lost. And affects the thermoforming cycle of the sheet. Further, if the difference between the two crystal melting points is too large, melt fracture may occur during sheet formation, which may impair the appearance of the sheet.

In the polypropylenes (A) and (B), α-olefins other than propylene copolymerized with propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, Examples thereof include 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 4-methyl-1-pentene, and 3-methyl-1-pentene. Propylene can be randomly copolymerized with one or more of these α-olefins. However, particularly preferred is a propylene-ethylene random copolymer.

The melt flow rate of the polypropylene (B) is preferably from 0.1 to 10.0 g / 10 min, more preferably from 0.1 to 5.0 g / 10 min. The melt tension of the polypropylene (B) is preferably 0.5 to 10.
0 cN, more preferably 0.5 to 5.0 cN. If the melt flow rate is less than 0.1 g / 10 min and the melt tension is greater than 10.0 cN, the transparency of the obtained sheet tends to decrease, and the transparency of the sheet after thermoforming tends to decrease. Rate is 10.0g
If the melt tension is higher than / 10 min and the melt tension is lower than 0.5 cN, the thermoformability of the obtained sheet tends to decrease.

Further, the polypropylene (B) is a propylene-ethylene random copolymer and has a crystal melting point of 1
30-150 ° C, melt flow rate 0.1-5.0g
/ 10 min, and a propylene-ethylene random copolymer having a melt tension in the range of 0.5 to 5.0 cN is particularly preferred. When the crystal melting point is 150 ° C. or less, the melt flow rate is 0.1 g / 10 min or more, and the melt tension is 5.0 cN or less, the region is particularly excellent in transparency and impact resistance.

Further, the crystal melting point is 130 ° C. or more, the melt flow rate is 5.0 g / 10 min or less, and the melt tension is 0.5.
When it is 5 cN or more, it is a region where rigidity, heat resistance and thermoformability are particularly excellent. Therefore, the above-mentioned range which is a range included in both the above-mentioned regions is particularly preferable. These polypropylenes (A) and polypropylenes (B) may be produced by any method as long as they have the properties specified in the present invention, and there is no particular limitation on the polymerization method, the type of catalyst, and the like.

The resin component constituting the resin composition of the present invention comprises 60 to 99 parts by weight of polypropylene (A) and 1 to 40 parts by weight of polypropylene (B). When the amount of the polypropylene (A) is less than 60 parts by weight, transparency and impact resistance are excellent, but rigidity and heat resistance are insufficient. Conversely, when the amount of the polypropylene (A) exceeds 99 parts by weight, the rigidity and heat resistance are excellent, but the transparency and impact resistance are poor.

The crystal nucleating agent used in the present invention is a compound containing a cyclic organic phosphate basic polyvalent metal salt as a main component. Examples of suitable metal atoms include aluminum, gallium, germanium, and titanium, with aluminum being particularly preferred.

Specifically, aluminum dihydroxy-
(4-t-butylphenyl) phosphate, aluminum hydroxy-bis (4-t-butylphenyl) phosphate, aluminum dihydroxy-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate Phosphate, aluminum dihydroxy-2,2'-methylene-bis (4-cumyl-6-t-butylphenyl) phosphate, aluminum hydroxy-bis [2,2'-methylene-bis (4,6-di-t- Butylphenyl) phosphate], aluminum hydroxy-
Bis [2,2'-methylene-bis (4-cumyl-6
-T-butylphenyl) phosphate], titanium dihydroxy-2,2'-methylene-bis (4,6-di-t-
Butylphenyl) phosphate, tindihydroxy-
2,2'-methylene-bis (4-cumyl-6-t-
Butylphenyl) phosphate, zirconium hydroxy-bis [2,2'-methylene-bis (4,6-di-t
-Butylphenyl) phosphate], aluminum dihydroxy-2,2'-methylene-bis (4-methylene-6-t-butylphenyl) phosphate, aluminum hydroxy-bis [2,2'-methylene-bis (4
-Methylene-6-t-butylphenyl) phosphate], aluminum dihydroxy-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, aluminum hydroxy-bis [2,2'- Ethylidene-bis (4,6-di-t-butylphenyl) phosphate].

As the crystal nucleating agent containing the above-mentioned cyclic organic phosphate ester basic polyvalent metal salt as a main component, a compound in which an alkali metal compound is blended is preferably used. A typical example of the alkali metal compound is an alkali metal carboxylate. Examples of the alkali metal include lithium, sodium, and potassium, and lithium is particularly preferable.
Examples of the carboxylic acids include aliphatic carboxylic acids such as acrylic acid, lauric acid, stearic acid, maleic acid, and citric acid; alicyclic carboxylic acids such as cyclopentanecarboxylic acid and cyclopentene carboxylic acid; and aromatic compounds such as benzoic acid and phthalic acid. Aromatic carboxylic acids can be exemplified, and among these, lauric acid is particularly preferred. One or more of the alkali metal compound and the cyclic organic phosphate basic multivalent metal salt can be blended, and the blending ratio is not particularly limited.

In the present invention, the compounding amount of the nucleating agent for 100 parts by weight of the resin component is preferably 0.05 to 1.0 part by weight. If the amount is less than 0.05 parts by weight,
The target performance such as transparency is not sufficient, and if it exceeds 1.0 parts by weight, it does not cause dirt or fogging of the take-off cooling roll at the time of sheet forming, but the effect of improving the performance such as transparency is low. It is saturated and not economical.

The resin composition of the present invention containing polypropylene (A), polypropylene (B) and a crystal nucleating agent as essential components includes known antioxidants, neutralizers, light stabilizers, and ultraviolet rays commonly used for polyolefins. Absorbent, inorganic filler,
Various additives such as an antiblocking agent, a lubricant, an antistatic agent, and a metal deactivator can be blended within a range that does not impair the purpose of the present invention.

Examples of the antioxidant include phenol-based antioxidants, phosphite-based antioxidants and thio-based antioxidants, and examples of the neutralizer include higher fatty acid salts such as calcium stearate and zinc stearate. Hindered amines, nickel complex compounds, benzotriazoles, as light stabilizers and ultraviolet absorbers,
Benzophenones can be exemplified.

Examples of the inorganic filler and the antiblocking agent include calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, and magnesium silicate. Examples of the lubricant include higher fatty acid amides such as stearic acid amide. Can be illustrated. Furthermore, examples of the antistatic agent include fatty acid partial esters such as glycerin fatty acid monoester, and examples of the metal deactivator include triazines, phosphones, epoxies, triazoles, hydrazides, oxamides, and the like.

The method of mixing the polypropylene (A) and the polypropylene (B) with the crystal nucleating agent and the above additives can be performed by using a high-speed stirring mixer such as a Henschel mixer (trade name), a ribbon blender or a tumbler mixer. And the like, followed by melt-kneading using an ordinary single-screw extruder or twin-screw extruder to form pellets.

The polypropylene resin composition of the present invention thus obtained can be molded into a transparent sheet by a method used in the production of ordinary polyolefin sheets such as extrusion molding, compression molding and casting. Any of the known and used molding methods can be employed. Among these, the extrusion molding method is preferred because of good productivity and transparency. Particularly preferably, an extruder, a feed block,
Using a T-die sheet forming machine equipped with a T-die, metal cooling roll, metal endless belt, guide roll, take-up roll, annealing roll, trimming cutter, masking, fixed size cutter, stacker, etc. This is an extrusion T-die method in which the molten resin extruded is drawn while being pressed between a metal cooling roll and a metal endless belt. The thickness of the transparent sheet of the present invention thus obtained is not particularly limited, but is usually 30 to
3,000 μm, preferably 100-500 μm
It is. If the thickness exceeds 3,000 μm, the internal haze increases and the transparency becomes poor.

The transparent sheet of the present invention can be used as a sheet constituting a multilayer transparent sheet. The multilayer transparent sheet referred to here is a sheet having at least one transparent sheet of the present invention and having a layer structure of two or more layers. Such a multilayer sheet can be manufactured by either a method of laminating sheets constituting each layer manufactured in advance, or a coextrusion film forming method using a resin constituting each layer. Further, such a multi-layer sheet, by selecting the resin constituting the tank other than the transparent sheet layer according to the present invention, transparency, while maintaining the effects of the present invention such as thermoformability, heat sealability, or Properties such as gas barrier properties can be imparted. The transparent sheet of the present invention can be not only an unstretched sheet but also a monolayer or biaxially stretched single-layer or multilayer sheet.

Various combinations can be considered for the layer constitution of the multilayer sheet of the present invention. For example, it is of course possible to combine a plurality of the polypropylene resin compositions of the present invention having different physical properties. However, when combined with a thermoplastic resin other than the resin composition of the present invention having a complementary relationship in physical properties with the resin composition of the present invention (hereinafter abbreviated as thermoplastic resin), a greater effect in practical use is obtained. Can be expected. Layers using thermoplastic resin / layers using the polypropylene resin composition of the present invention, two layers, layers using the polypropylene resin composition of the present invention / layers using the thermoplastic resin / different heat A layer using a thermoplastic resin, or a layer using the polypropylene resin composition of the present invention / a layer using a thermoplastic resin / a layer using the polypropylene resin composition of the present invention,
Examples thereof include two or three layers or three or three layers of a polypropylene-based resin transparent multilayer sheet.

The transparent sheet of the present invention has printability, paintability,
For the purpose of imparting metal vapor deposition properties and the like, surface treatment such as corona discharge treatment, flame treatment, or plasma treatment, which is usually employed industrially, is possible.

[0036]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The methods for measuring the physical properties of the polypropylene (A) and the polypropylene (B) used in Examples and Comparative Examples are shown below. a) Crystal melting point (unit: ° C.): DSC (differential scanning calorimeter)
The temperature was the temperature at which the melting peak appeared in the thermal behavior curve determined by the above. b) MFR (unit: g / 10 min): JIS K72
At a heating temperature of 230 ° C. and a load of 21.2 N according to
It was measured. c) Melt tension (unit: cN): A sample heated at 230 ° C. and melted by using a melt tension tester type 2 (manufactured by Toyo Seiki Seisaku-sho, Ltd.) from a 2.095 mm diameter nozzle at a speed of 20 mm / min. And extruded into the atmosphere at 23 ° C,
The tension at the time of pulling the obtained strand at a speed of 3.14 m / min was measured.

Next, the methods for producing the transparent sheets used in the examples and comparative examples will be described below. Examples 1 to 6, Comparative Examples 1 to 6 Resin component 1 composed of polypropylene (A) and polypropylene (B) having the compositions shown in Tables 1 and 2.
The crystal nucleating agent (trade name: ADK STAB NA2) containing, as a main component, a cyclic organic phosphate basic aluminum salt containing lithium laurate with respect to 00 parts by weight.
1. Asahi Denka Kogyo Co., Ltd.) or 0.3 parts by weight of a crystal nucleating agent having an alkyl-substituted dibenzylidene sorbitol as a main component (trade name: Gelol DH, manufactured by Shin Nippon Rika Co., Ltd.), a phenolic antioxidant Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (trade name: ADK STAB AO-60, manufactured by Asahi Denka Kogyo Co., Ltd.)
1 part by weight, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite which is a phosphite-based antioxidant (trade name: ADK STAB PEP-36, manufactured by Asahi Denka Kogyo Co., Ltd.) 0.1 parts by weight and calcium stearate as a neutralizing agent (trade name: calcium stearate, manufactured by NOF Corporation)
0.10 parts by weight were mixed and mixed at room temperature for 3 minutes with a high-speed stirring mixer (Note: Henschel mixer, trade name), and the obtained mixture was extruded using a 90 mm screw extrusion granulator. Granulation was performed at a resin temperature of 250 ° C.

Each of the obtained granulated products was screwed with a screw diameter of 90.
melted and plasticized at a resin temperature of 250 ° C. using a sheet extruder with a thickness of 2.5 mm, and extruded from a T-die (die width: 1200 mm, die lip interval: 0.6 mm) to reduce the surface temperature to 60 ° C.
A sheet having a thickness of 300 μm is continuously drawn at a speed of 15 m / min while being pressed between a mirror-finished metal cast roll controlled to a temperature of 20 ° C. and a mirror-finished metal endless belt whose surface temperature is controlled to 20 ° C. I got The punch impact strength, heat deformation temperature, Young's modulus, haze,
The degree of dirt and fogging of the take-off cooling roll during sheet forming was evaluated. The results are shown in Tables 1 and 2.

Next, the obtained sheet is placed in the opening 206.
mm x 131 mm, depth 16 mm, bottom 186 mm x 1
Vacuum pressure forming was performed using a 17 mm female (concave) forming die, and the sheet was evaluated for drawdown during vacuum pressure forming and haze at the bottom of the vacuum pressure formed product. Table 1 shows the results
And shown in Table 2.

These evaluation methods are as follows. a) Punching impact strength (unit: J): ASTM D781
The sheet cured at 23 ° C. was subjected to a punching impact test using a pendulum-type punching impact tester according to (1989). b) Heat deformation temperature (unit: ° C.): JIS K7207 (1
In accordance with 996), the sheet was subjected to a load of 0.45 MPa and a deflection of 260 μm was generated, and the heat distortion temperature was measured. c) Young's modulus (unit: MPa): a tensile speed of 5 mm / min using a tensile tester according to ASTM D882.
Was used to measure the 1% modulus when the sheet was pulled. d) Haze (unit:%): The haze of the sheet was measured using a haze meter according to ASTM D1003.

E) Degree of dirt and cloudiness of take-off cooling roll (unit: none): At the time of sheet forming, the degree of dirt and cloudiness of the take-off cooling roll and the like was visually confirmed for about one hour.
(○: Dirt, fogging, and no transfer to sheet occurred, ×:
F) Sheet appearance (unit: none): After forming the sheet, the surface appearance of the sheet after 48 hours has been visually observed, and dirt transfer such as a take-off cooling roll is performed. The trace of melt fracture was confirmed. (○: beautiful appearance, ×: remarkably impairs the appearance) g) Drawdown during vacuum and pressure forming (unit: mm): The amount of drawdown (the amount of sag) when the sheet is heated in the molding machine is measured by infrared rays It was measured with a sensor. h) Haze (unit;%) at the bottom of vacuum-pressed air molded product: AST
In accordance with MD1003, the haze of a test piece cut from the bottom of a vacuum-pressure molded article was measured.

Example 7 The resin composition used in Example 1 was used as the outermost layer, and an adhesive polyolefin (trade name: ADMER, manufactured by Mitsui Chemicals, Inc.)
Was used as a second layer, and an ethylene-vinyl alcohol copolymer (trade name: EVAL, manufactured by Kuraray Co., Ltd.) was used as a central layer to manufacture a multilayer sheet of three types and five layers. Using the obtained multilayer sheet, vacuum and pressure forming was performed in the same manner as in Example 1.
Table 1 shows the results of the evaluation of the obtained multilayer sheet and vacuum-pressure molded article.

[0043]

[Table 1]

[0044]

[Table 2]

From the data shown in the table, the haze value of the sheet raw material and the bottom of the vacuum pressure-pneumatic molded product is smaller in the example of the present invention than in the comparative example, and the transparency is maintained even after thermoforming. It excels in punch impact strength, which is an index of impact resistance, heat distortion temperature, which is an index of heat resistance, and Young's modulus, which is an index of stiffness. It is clear that the finish is beautiful, and the value of the drawdown at the time of vacuum pressure forming is small and the vacuum pressure forming is excellent.

[0046]

The polypropylene resin transparent sheet of the present invention satisfies all of the performances of transparency, impact resistance, heat resistance and rigidity in a practical sense, and is a polyvalent alcohol such as conventional dibenzylidene sorbitol. -The appearance of the sheet can be beautifully finished without causing dirt or fogging of a take-off cooling roll or the like at the time of sheet forming, which has occurred when using a crystal nucleating agent represented by a metal derivative. Further, it is a transparent sheet having a small drawdown at the time of thermoforming of the sheet and excellent in thermoformability, and also excellent in transparency after thermoforming. Therefore, foods that need thermoforming,
It can be widely used in fields such as cases and stationery mainly in the field of packaging materials such as pharmaceuticals. Specifically, it is suitably used for lid sheets, PTP sheets, blister pack sheets and the like for various side dish containers and lunch containers that can be used in a microwave oven.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA20 AA84 AC15 AH04 AH12 BA01 BB06 BC01 4F100 AK07A AK64A AK66A AL05A AR00B BA02 BA07 BA15 CA30A JA04A JA06A JA11A JJ03 JK01 JK10 JN01 JN0100JN01 BB01 BB01 BB01 BB01BC FD170 FD200 GG00 GL00

Claims (10)

[Claims] 1. A polypropylene (A) having the following properties: 60 to 99 parts by weight;
The resin component consisting of 40 parts by weight was mixed with a crystal nucleating agent containing a cyclic organic phosphate basic polyvalent metal salt.
A polypropylene-based resin composition in which 0.05 to 1.0 part by weight is blended with respect to 00 parts by weight; polypropylene (A): a crystalline melting point (TmA) of 150 to
Propylene homopolymer or propylene-α-olefin (including ethylene; the same applies hereinafter) in the range of 170 ° C.
Random copolymer, polypropylene (B): a propylene-α-olefin random copolymer having a crystal melting point (TmB) lower by 5 to 50 ° C. than the crystal melting point (TmA) of polypropylene (A). 2. The polypropylene resin composition according to claim 1, wherein the polypropylene (A) is a polypropylene having a melt flow rate of 0.1 to 10.0 g / 10 min. 3. The polypropylene (A) has a melt tension of 0.5.
The polypropylene-based resin composition according to claim 1, which is a polypropylene of 1 to 15.0 cN. 4. The polypropylene (A) has a crystalline melting point (T
The polypropylene resin composition according to any one of claims 1 to 3, wherein the polypropylene is a polypropylene having a mA of 155 to 165C. 5. Polypropylene (B) having a melt flow rate of 0.1 to 10.0 g / 10 min.
-The polypropylene resin composition according to any one of claims 1 to 4, which is an olefin random copolymer. 6. The polypropylene (B) has a melt tension of 0.5.
The polypropylene resin composition according to any one of claims 1 to 5, which is a propylene-α-olefin random copolymer having a viscosity of 5 to 10.0 cN. 7. The polypropylene (B) has a crystal melting point (T
The polypropylene resin composition according to any one of claims 1 to 6, wherein the polypropylene resin is a propylene-α-olefin random copolymer at a temperature of 130 to 150 ° C. 8. The polypropylene resin composition according to claim 7, wherein the nucleating agent is a nucleating agent containing a cyclic organic phosphate basic polyvalent metal salt and an alkali metal compound. 9. A transparent sheet comprising the polypropylene resin composition according to any one of claims 1 to 8. 10. A multilayer transparent sheet having at least one layer of the transparent sheet according to claim 9.