JP2650622B2 - Polypropylene composition and sheet comprising the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene composition excellent in transparency, rigidity and moisture resistance, and a sheet comprising the same.

[0002]

2. Description of the Related Art Conventionally, polyvinyl chloride, polystyrene and the like have been used as highly transparent sheet materials, but in recent years, polypropylene sheets have been widely used instead of these. Polypropylene has lower moisture permeability than polyvinyl chloride and polystyrene sheets, and is used for packaging tablets, capsules, foods, and the like of pharmaceuticals. Press-through pack packaging (hereinafter abbreviated as PTP), which is a type of this packaging material, has favorable physical properties, but has poor transparency, and has a narrow processing temperature range during vacuum and pressure forming. Had the disadvantage of saying Therefore, at present, a PVC sheet is mainly used for this purpose.
However, moisture-sensitive chemicals such as aspirin and antibiotics cannot be used unless multi-layered with polyvinylidene chloride, which has low moisture permeability, because the moisture permeability is too large, resulting in a significant increase in cost. I was

[0003]

As described above, P
In the TP field, there has been a problem that a sheet made of a conventional polypropylene composition has poor transparency and rigidity, and a vinyl chloride sheet has poor moisture resistance. SUMMARY OF THE INVENTION An object of the present invention is to provide a polypropylene composition and a sheet comprising the polypropylene composition in which these problems are improved.

[0004]

According to the present invention, a composition comprising 70 to 95 parts by weight of a polypropylene (A) and 30 to 5 parts by weight of an aliphatic or alicyclic petroleum resin (B) is prepared. In the presence, the following compound, talc (C), organic carboxylate and its metal salt (D), organic phosphate metal salt (E), polyvinylcycloalkane (F) and General formula,

[0005]

Embedded image (Wherein, R is any one of alkyl having 1 to 8 carbons, halogen, and alkoxy having 1 to 4 carbons and may be different in the same compound. M and n are each independently 0-
It can take an integer of 3. A) selected from dibenzylidene sorbitol derivatives (G) represented by the formula (G) in an amount of from 0.5 ppm to 10,000 ppm by weight,
A polypropylene composition characterized by being blended and a sheet comprising the same. Here, the polypropylene may be decomposed by peroxide before being mixed with the aliphatic or alicyclic petroleum resin, or may be decomposed after being mixed. As described above, by blending a petroleum resin with polypropylene and performing peroxide decomposition, a sheet composition having even more excellent transparency can be obtained.

The polypropylene used in the present invention is a homopolypropylene, a random copolymer of propylene with an α-olefin such as ethylene, butene-1 or the like. Above all, MI = 4 g / 10 min. The following homopolypropylene is preferable from the viewpoint of balance between transparency and moisture resistance. Further, as a petroleum resin used in the present invention, a molecular weight of 500-500 described in JP-A-51-91955 is used.
Aliphatic or alicyclic petroleum resins having a 5,000 and a softening point of 50-170 ° C. The preferred proportions of the resin components are 95-70 parts by weight of polypropylene and 5-3 of petroleum resin.
0 parts by weight, more preferably polypropylene 9
0-80 parts by weight and 10-20 parts by weight of petroleum resin. When the amount of the petroleum resin is less than 5 parts by weight, the effect of improving the transparency is small, and when the amount is more than 30 parts by weight, the obtained sheet becomes brittle, which is not preferable.

The types of nucleating agents used in the present invention include, for example, the following. That is, sodium benzoate, para-tert-butyl aluminum benzoate (Pt
-Butyl benzoic acid aluminum salt), sodium tertiary butyl phosphate (sodium Pt-butyl phosphate), talc, dibenzylidene sorbitol or a derivative thereof, among which aluminum benzoate and para tertiary butyl phosphorus Acid sodium salts are preferably used.
The addition amount of these nucleating agents is preferably 0.01 to 1 part by weight, and more preferably 0.02 to 0.3 part by weight.

[0008] Examples of polyvinylcycloalkanes include:
There are polyvinylcyclopentane, polyvinylcyclohexane, polyvinylnorbornane and the like, and among them, polyvinylcyclohexane is particularly preferably used. Polyvinylcyclohexane is effective at a very low concentration of 0.00005 parts by weight or more, and exhibits excellent effects in terms of hygroscopicity and no migration to contents. The method for producing polyvinylcycloalkane is as follows:
This is disclosed in JP-A-60-139710. That is, the polyvinylcycloalkane used in the present invention is:
After polymerizing vinylcycloalkane using a Ziegler-Natta catalyst or the like, or after polymerizing vinylcycloalkane in the first stage, propylene was copolymerized alone or with another α-olefin in the second stage. The first stage and the second stage may be performed in reverse order.

The organic peroxide used in the present invention is not particularly limited, but it must be industrially easy to handle and effective. That is, the half-life is 15
Those at 0 ° C. for 0.5 minutes or more are preferred. For example, 2,5
-Dimethyl-2,5-di (t-butyl-peroxy) hexane, 1,1-bis (t-butyl-peroxy) 3,
3,5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, t-butylpa-3,
3,5-trimethylhexanoate, 1,3-bis (2
-T-butylperoxyisopropyl) benzene and the like. The amount of the organic peroxide to be added is appropriately determined depending on the starting materials, the MI of the target composition, the organic peroxide decomposition temperature, time, and the like.

The peroxide decomposition of polypropylene is carried out by a known method. For example, the heat treatment is performed by heating a mixture of polypropylene and an organic peroxide using a Banbury mixer, a roll, an extruder, or the like. Economically, a continuous extruder is desirable. At this time, if necessary, other components such as a petroleum resin and a nucleating agent may be simultaneously added. Still other additional components are antioxidants, lubricants, antistatic agents,
You may mix a pigment etc. The peroxide decomposition may be performed at any stage of the process for producing the composition. That is, only polypropylene may be peroxide-decomposed in advance, or after mixing with petroleum resin or after mixing with petroleum resin and other components. The molecular weight distribution Mw / Mn of the peroxide-decomposed polypropylene is not particularly limited, but is preferably 5.0 or less. Here, Mw / Mn is determined by the following method. Equipment Waters GPC 150 type Column Shodex80M / S 3 pieces Measurement temperature 140 ° C Solvent Using o-dichlorobenzene, 14 kinds of monodisperse polystyrene (standard product manufactured by Toyo Soda,
Mw = 500 to 6.77 × 10 ⁶ ) to determine a calibration curve.

The method of processing the composition thus obtained into a sheet is usually carried out by a T-die method. The sheet usually has a thickness of 0.1-3 mm, especially PTP
In many cases, the thickness is 0.1-0.3 mm. The MI of the obtained sheet is 0.5-10 g / 1.
0 min. And more preferably 1-6 g / 10 min.
Is preferred. That is, 0.5 g / 10 min. Below, the surface roughness of the sheet is large, the transparency becomes poor, and 10 g
/ 10 min. This is because the sheet becomes brittle above.

[0012]

The following examples and comparative examples are given, but the present invention is not limited by these examples. The methods for measuring physical properties in Examples and Comparative Examples are as follows. (1) Melt index (MI) JIS-K-67
58 (2) Tensile Young's Modulus JIS-D-7113 (3) All Haze ASTM-D-1003 (4) External Haze ASTM-D-1003, specifically, immersing the obtained sheet in dimethyl phthalate To obtain an internal haze from which the influence of rough skin is removed. A value obtained by subtracting this from all the haze indicates an external haze, that is, a state of rough skin. Outer Haze = All Haze−Inner Haze (5) Permeability ASTM-E-96

Reference Example-1 MI = 0.5 g / 10 min. Homopolypropylene 8
5 parts by weight of petroleum resin Alcon P125 (Arakawa Chemical) 1
5 parts by weight, 0.04 part by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (Perhexa 25B, manufactured by NOF Corporation), 0.001 part by weight of di-t-butyl-p-cresol Part, tetrakis [methylene-3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate] 0.001 part by weight of methane and 0.0005 part by weight of calcium stearate are blended, and mixed with a Henschel mixer at room temperature at 250 rpm for 3 minutes.
The composition was obtained by pelletizing at 65 ° C. using an extruder having a diameter of 65 mm. This composition was set at a set temperature of 280 ° C.
Extrusion sheeting was performed using an extruder with a diameter of m.
A 25 mm sheet was obtained. At this time, the temperature of the chill roll is 3
5 ° C.

Example 1 0.1 parts by weight of aluminum benzoate were simultaneously added to the composition of Reference Example 1 to obtain a composition and a sheet under the same conditions as in Reference Example 1. Table 1 shows the physical properties of the obtained sheet. Good transparency, rigidity and moisture resistance were obtained.

Example-2 MI = 0.5 g / 10 min. Homopolypropylene 8
5 parts by weight of petroleum resin Alcon P125 (Arakawa Chemical) 1
5 parts by weight, a polypropylene containing polyvinylcyclohexane obtained by the method of JP-A-60-139710 as a nucleating agent is 0.01 part by weight as polyvinylcyclohexane, and 1,3-bis (2 0.02 parts by weight of -t-butylperoxyisopropyl) benzene (TY-13, manufactured by Sanken Kako) was added,
Other compositions, mixing and extrusion conditions were the same as in Reference Example 1 to obtain a composition and a sheet. Table 1 shows the physical properties of the obtained sheet. Good transparency, rigidity and moisture resistance were obtained.

Example 3 The procedure of Example 2 was repeated except that 1,3-bis (2-t-butylperoxyisopropyl) benzene (TY-13, manufactured by Sanken Kako) was used in an amount of 0.04 parts by weight. A composition and a sheet were obtained in the same composition as in Example 2, and under the same extrusion conditions as in Reference Example 1. Table 1 shows the physical properties of the obtained sheet. Good transparency, rigidity and moisture resistance were obtained.

Example-4 MI = 1 g / 10 min. 15 parts by weight of petroleum resin Alcon P125 (manufactured by Arakawa Chemical) is mixed with 85 parts by weight of
0.02 parts by weight of 2,5-di (t-butylperoxy) hexane (Perhexa 25B, manufactured by NOF Corporation) and 1,3,2,4- (p-methyldibenzylidene) sorbitol (Gerol MD as a nucleating agent) , Nippon Rika Co., Ltd.), a composition and a sheet were obtained in the same manner as in Reference Example 1 except for the other components, mixing and extrusion conditions. Table 1 shows the physical properties of the obtained sheet. Transparency as shown in Table 1,
Good moisture-proof properties were obtained.

Example-5 MI = 1 g / 10 min. 15 parts by weight of petroleum resin Alcon P125 (manufactured by Arakawa Chemical) is blended with 85 parts by weight of homopolypropylene, and sodium tertiary butyl phosphate (NA-10 manufactured by Adeka Argas Chemical) 0.1 as a nucleating agent
Parts by weight, other components and mixing, extrusion conditions,
A composition and a sheet were obtained in the same manner as in Example-4. Table 1 shows the physical properties of the obtained sheet. Good transparency and moisture-proof properties were obtained.

Comparative Examples 1-3: MI = 1 g / 10 min. Homopolypropylene 97 ~
65 parts by weight of petroleum resin Alcon P125 (Arakawa Chemical)
A composition and a sheet were obtained in the same manner as in Reference Example 1, except that 3 to 35 parts by weight were added and the nucleating agent and the organic peroxide were not added. Table 1 shows the physical properties of the obtained sheet. The balance between transparency and moisture resistance is poor.

Comparative Examples -4 to 10 Without the use of an organic peroxide, MI of homopolypropylene,
A composition and a sheet were obtained in the same manner as in Reference Example 1, except that the types and amounts of the petroleum resin and the nucleating agent were changed. Table 1 shows the physical properties of the obtained sheet. These have good rigidity and moisture resistance, but are inferior in transparency as compared with Examples-1 to 5 in which peroxide decomposition is performed.

[0021]

[Table 1]

[0022]

The composition of the present invention and the sheet comprising the composition obtained as described above are excellent in transparency, rigidity and moisture resistance and can be applied to various uses.

──────────────────────────────────────────────────の Continuing on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C08K 5/09 KEP C08K 5/09 KEP 5/098 5/098 5/14 KES 5/14 KES / / (C08L 23/10 57:02)

Claims (4)

(57) [Claims] 1. A polypropylene composition obtained by thermally decomposing a composition comprising 70 to 95 parts by weight of a polypropylene (A) and 30 to 5 parts by weight of an aliphatic or alicyclic petroleum resin (B) in the presence of an organic peroxide. Talc (C), an organic carboxylate and its metal salt (D), an organic metal phosphate (E), a polyvinylcycloalkane (F), and a general formula (Wherein, R is any one of alkyl having 1 to 8 carbons, halogen, and alkoxy having 1 to 4 carbons and may be different in the same compound. M and n are each independently 0-
It can take an integer of 3. ), One or more selected from dibenzylidene sorbitol derivatives (G), from 0.5 ppm to 10,000 ppm by weight,
A polypropylene composition characterized by being blended. 2. The polypropylene composition according to claim 1, wherein the compound (D) is pt-butyl benzoic acid aluminum salt. 3. The polypropylene composition according to claim 1, wherein the compound (E) is pt-butyl phosphate sodium salt. 4. The polypropylene composition according to claim 1, wherein the compound (F) is polyvinylcyclohexane.