JP3395159B2 - Polypropylene composition - 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, and more particularly to a polypropylene composition having excellent transparency, rigidity and impact resistance.

[0002]

Polypropylene has been widely used for sheets, bottles, cases, pipes and various industrial parts, but since it is crystalline, light scatters in molded articles.
The transparency was not satisfactory. In order to solve this, conventionally, modification has been carried out by blending a carboxylic acid or the like, but the compatibility with the resin is poor, and
The resulting composition has low rigidity, which is not preferable.

Further, various nucleating agents or Mg and Mg
_4.5 Al ₂ (OH) ₁₃ CO ₃ · nH ₂ O is also used in combination with hydrotalcite as shown, but the transparency, impact resistance and rigidity are still insufficient. Further, it has been desired to improve these physical properties.

[0004]

SUMMARY OF THE INVENTION From the above background, it is an object of the present invention to provide a polypropylene composition having excellent transparency, rigidity and impact resistance.

[0005]

[Means for Solving the Problems] The present inventors have made extensive studies in order to solve such drawbacks. as a result,
It has been found that the above problems can be solved by blending polypropylene with hydrotalcite containing a zinc element, and the present invention has been proposed.

That is, the present invention relates to (a) polypropylene
100 parts by weight (b) Carboxylic acid metal salt-based compound, aromatic phosphoric acid metal salt
Compounds and dibenzylidene sorbitol compounds
Hydrotalcite containing 0.01 to 1.0 parts by weight of a selected nucleating agent (c) zinc element
It is a polypropylene composition comprising 0.01 to 0.5 parts by weight.

In the present invention, as the polypropylene as the component (a), known polypropylenes can be used without any limitation. Specifically, it may be a homopolymer of propylene or a copolymer of propylene and another α-olefin. Examples of the α-olefin other than propylene include ethylene, 1-butene, 1-pentene, 4-methylpentene-1 and the like. The polypropylene most preferably used in the present invention includes propylene homopolymer, propylene / ethylene copolymer, and propylene /
It is an ethylene / 1-butene copolymer. Considering the rigidity of the resulting polypropylene composition, the propylene
The ethylene content of the ethylene copolymer is 0.1 to 8 mol%, preferably 0.1 to 5 mol%, while the ethylene content of the propylene / ethylene / 1-butene copolymer is 0.1. 8 mol% and 1-butene content is 0.1-6
It is preferably mol%. Further, in the present invention, in addition to these polypropylenes, other resins such as polyethylene, poly-1-butene, poly-1-pentene, poly-4-methylpentene-1 may be mixed and used. At this time, the other resin is 1 to 4 with respect to 100 parts by weight of polypropylene.
It is preferable to add 0 part by weight.

In the present invention, such polypropylene may be obtained by any method.
In general, a Ziegler-Nutter type stereospecific catalyst, a magnesium chloride-supported titanium-containing catalyst or a titanium trichloride-modified stereospecific catalyst and a co-catalyst such as triethylaluminum or diethylaluminum are used as propylene or other α-olefin. Those obtained by polymerizing in addition to the mixture with are preferable.

The polymerization method may be either one in the gas phase or in the liquid phase. Further, it may be polymerized in an inert liquid or an inert solvent for the catalyst. In addition to such polymerization by batch,
It may be produced by multistage polymerization. In such multi-stage polymerization, a gas phase alone or a liquid phase alone may be prepared, or a combination of a liquid phase polymerization step and a gas phase polymerization step may be prepared. It may be one whose molecular weight is adjusted by introducing hydrogen during the polymerization, or one whose polymer obtained is degraded by a molecular weight modifier such as an organic peroxide.

In the present invention, the flowability of polypropylene is not particularly limited, but in consideration of moldability, rigidity and impact resistance, melt flow rate (hereinafter, referred to as MFR).
Preferably about 0.1 to 80 g / 10 min. Where this melt flow rate is the cylinder
-Value at 230 ° C.

The nucleating agent which is the component (b) in the present invention is specifically aluminum benzoate, potassium benzoate, sodium benzoate, lithium benzoate, Al-.
p-butylbenzoate, sodium β-naphthoate,
Carboxylic acid metal salt compounds such as sodium cyclohexanecarboxylate and sodium cyclopentanecarboxylate;
Bis (4-t-butylphenyl) phosphoric acid sodium salt,
Lithium bis (4-t-butylphenyl) phosphate, aluminum bis (4-t-butylphenyl) phosphate,
2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid sodium salt, 2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid lithium salt, 2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid aluminum salt, 2,2′- methyle
Down - bis (4,6-di -t- butyl phenyl) phosphate salt, 2,2'-ethylidene - bis (4,6-di -t- butyl phenyl) sodium phosphate, 2,2 '
-Ethylidene-bis (4,6-di-t-butylphenyl) phosphate lithium salt , 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate aluminum salt, bis (4- Aromatic metal phosphate-based compounds such as t-butylphenyl) calcium phosphate; dibenzylidene sorbitol, 1,3,2,4-di (methylbenzylidene) sorbitol, 1,3,2,4-di (ethylbenzylidene) Sorbitol, 1,3,2,4-di (butylbenzylidene) sorbitol, 1,3,2,4-di (methoxybenzylidene) sorbitol, 1,3,2,4-di (ethoxybenzylidene) sorbitol, 1,3 -Dibenzylidene such as chlorobenzylidene sorbitol , 2,4-methylbenzylidene sorbitol, mono (methyl) dibenzylidene sorbitol Densorbitol compounds, etc.
Is mentioned. Of these, it is most preferable to use a dibenzylidene sorbitol compound.

In the present invention, the blending amount of the nucleating agent is
0.01 to 100 parts by weight of the olefin polymer
It is 1.0 part by weight. Among these, 0.03-0.7 weight part is preferable. That is, when the amount of the nucleating agent is less than 0.01 part by weight, the transparency is insufficiently expressed, and when it exceeds 1.0 part by weight, the transparency is sufficiently expressed but the effect reaches a ceiling and the economy is reduced. It becomes untargetable. The nucleating agents may be used alone or in combination of two or more.

In the present invention, in addition to the polypropylene component and the nucleating agent component, hydrotalcite containing a zinc element is added as the component (c). Thereby, the nucleating agent and the compound act synergistically, and the polypropylene composition of the present invention is
In addition to transparency, rigidity and impact resistance are extremely good. It is a compound similar to the compound, Mg _{4. 5}
With a normal hydrotalcite compound having no zinc in the molecule such as Al ₂ (OH) ₁₃ CO ₃ .nH ₂ O, the improvement in physical properties as good as that of the present invention is not recognized.

In the present invention, as the hydrotalcite containing the zinc element, hydrotalcite which is a basic carbonate mineral and contains the zinc element in the molecule can be used without any limitation. Specifically, Mg _m ZnAl _{n
(OH) p (CO 3)} q · sH 2 O ( where, m is 0.1 to 4
It is preferably a number of 1 to 3, n is a number of 0.1 to 6, preferably 1 to 6, and p is 0.1 to 36, preferably 1 to
14), q is 0.1-3, preferably 1-3, and s is 0-10, preferably 0-3). Of these, Mg ₃
It is most preferable to use one represented by ZnAl ₂ (OH) ₁₂ CO ₃ sH ₂ O (where s is the same as above). An example of such hydrotalcite is Mg ₃
ZnAl ₂ (OH) ₁₂ CO ₃ · H ₂ O, Mg ₃ ZnAl
_{2 (OH) 12 CO 3 ·} 2H 2 O , and the like.

In the present invention, the blending amount of the above-mentioned hydrotalcite containing elemental zinc is 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the olefin polymer. Among these, 0.02-0.4 weight part is preferable. That is, if the compounding amount of the compound is less than 0.01, the expression of transparency is insufficient, and if it exceeds 1.0 part by weight, the expression of transparency is sufficient but the effect reaches a ceiling and the economy is reduced. It becomes untargetable. In addition, even if only one kind of this compound is used,
You may use together 1 or more types.

In the present invention, the above-mentioned respective components can be blended by any ordinary method which is carried out by mixing resins without any limitation. For example, a method of adding the components (b) and (c) to the powder or pellet-shaped component (a), mixing them with a tumbler, a Henschel mixer, etc., and then melt-kneading them with an extruder to form pellets, etc. It is suitable.
The order of addition of each component is not particularly limited, and the components may be mixed in an order different from the above method. In addition, make a masterbatch that concentrates each component in high concentration,
It can also be used as a mixture.

Various additives may be appropriately added to the composition of the present invention as long as the effects of the invention are not impaired. Specifically, phenol-based, organic phosphite-based, phosphorous-based organic phosphorus-based, thioether-based antioxidants, hindered amine-based heat stabilizers, benzophenone-based, benzotriazole-based, benzoate-based UV absorbers, etc. Nonionic, cationic, anionic antistatic agents; bisamide-based, wax-based, organometallic salt-based dispersants; alkaline earth salt carboxylate-based chlorine scavengers; amide-based, wax-based , Organometallic salt-based and ester-based lubricants; oxide-based decomposing agents; hydrazine-based, amine-based metal deactivators; organic pigments; inorganic pigments;
Foaming agents; flame retardants; inorganic fillers such as mica, wollastonite, calcium carbonate, glass; organic fillers and the like.

[0018]

The polypropylene composition of the present invention has excellent rigidity and impact resistance, and also has extremely good transparency. Furthermore, the transparency is not hazy, and the transparency has a refreshing feeling. In the present invention, the mechanism by which such good properties such as transparency, rigidity, and impact resistance are expressed is not clear, but the familiarity of hydrotalcite containing the above zinc element to the nucleating agent is not clear. It is presumed that a good effect can be obtained by the synergistic effect of these.

Therefore, the polypropylene composition of the present invention includes various molded articles such as films, sheets, bottles, cases, pipes and industrial parts, specifically, clothes cases, food containers, disposable syringes, needle covers. , Infusion packs, blood packs, tails, stationery binders, wrapping films, cassette cases, liquid bottles, retort packs, fibers, yarns, and other molded articles that require transparency can be extremely usefully used.

[0020]

EXAMPLES In order to more clearly explain the present invention, examples and comparative examples will be described below, but the present invention is not limited to these examples.

In the examples, various physical properties were measured by the following methods.

(1) Haze The measurement was performed according to JIS K7105.

(2) Flexural modulus The measurement was performed according to JIS K7203.

(3) Izod impact value The measurement was performed according to JIS K7110.

(4) Permeability When a product is seen through a flat plate-shaped molded product, it is possible to see through without a feeling of haze. Those that could not be improved were evaluated as x.

Examples 1 to 5 0.04 parts by weight of a hindered phenol antioxidant as an antioxidant and 100% by weight of a polypropylene homopolymer having an MFR of 10 g / 10 min at 230 ° C. and a heat stabilizer. Phosphide antioxidant 0.04
% By weight and 1.3, 2.4 of the blending amount shown in Table 1.
Di (p-methylbenzylidene) sorbitol (Shin Nippon Rika Co., Ltd., Gelol MD) and Mg ₃ ZnAl ₂ (O
H) ₁₂ CO ₃ .H ₂ O (Kyowa Chemical Industry Co., Ltd., ZHT-
4A) was blended and thoroughly mixed by stirring with a 20 L Henschel mixer. After that, melt kneading was performed with an extruder heated to 230 ° C., and strand cutting was performed to obtain a target polypropylene composition . Then, a flat molded article of 100 × 50 × 1 mmt was obtained with an injection molding machine. still,
The mold used at the time of molding was a mirror-finished mold by buffing. The haze and the
And transparency were measured. Also, the above polypropylene group
Regarding the flexural modulus and Izod impact value of the product,
The measurement was performed by the method shown. The results are shown in Table 1.

Comparative Examples 1 to 4 In Example 2, 1.3,2.4-di (p-methylbenzylidene) sorbitol or Mg ₃ ZnAl ₂ (O
H) ₁₂ CO ₃ · H ₂ O is not blended, or instead of this, Mg
_A polypropylene composition was obtained by the same method as in Example 2 except that 0.3 parts by weight of _4.5 Al ₂ (OH) ₁₃ CO ₃ .3.5H ₂ O or calcium stearate was used. About this polypropylene composition, Example 2 and
Similarly flexural modulus, Izod impact value, haze and perspective
The sex was measured. The results are shown in Table 1.

Example 6 Ethylene content 4.0 mol%, MFR 10 g / 10 m
A polypropylene composition was obtained by the same method as in Example 2 except that in propylene ethylene random copolymer was used as the resin component. This polypropylene composition
And flexural modulus and Izod impact as in Example 2.
The values, haze and transparency were measured. The results are shown in Table 1.

Examples 7 to 9 In Example 2, 1.3,2.4-di (p-methylbenzylidene) sorbitol or Mg ₃ ZnAl ₂ (O
H) A polypropylene composition was obtained by the same method as in Example 2 except that the various compounds shown in Table 1 were blended in place of ₁₂ CO ₃ .H 2 O. For this polypropylene composition,
Bending elastic modulus, Izod impact value, and Hay as in Example 2.
And the transparency were measured. The results are shown in Table 1.

[0030]

[Table 1]

Claims (2)

(57) [Claims] 1. (a) Polypropylene
100 parts by weight (b) Carboxylic acid metal salt-based compound, aromatic phosphoric acid metal salt
Compounds and dibenzylidene sorbitol compounds
Hydrotalcite containing 0.01 to 1.0 parts by weight of a selected nucleating agent (c) zinc element
A polypropylene composition comprising 0.01 to 0.5 parts by weight. 2. The metal carboxylate compound is Al
-P-butyl benzoate, wherein the aromatic gold phosphate is
The group salt compound is 2,2'-methylene-bis (4,6-
Di-t-butylphenyl) aluminum phosphate and 2,
2'-methylene-bis (4,6-di-t-butylphenyi
2.) Polypro according to claim 1, which is sodium phosphate.
Pyrene composition.