JPH08113681A - Polypropylene resin composition and its production - Google Patents

Abstract

PURPOSE: To obtain a polypropylene resin composition excellent in transparency, flexibility, etc., by using a polypropylene and an elastomeric propylene/ethylene/α-olefin copolymer having a specified composition and specified properties as the constituents at a specified ratio. CONSTITUTION: This resin composition consists of 10-65 pts.wt. polypropylene (A), optionally copolymerized with at most 20wt.% ethylene and/or a-olefin and 90-35 pts.wt. elastomeric propylene/ethylene/α-olefin copolymer (B) which contains 20-80wt.% propylene, 10-45wt.% ethylene and 10-45wt.% a-olefin (the total content being 100wt.%) and whose crystalline component having a peak at 60-130 deg.C has a fusion enthalpy of at most 20j/g, as determined with a differential scanning calorimeter. The composition is effectively used in the fields of packaging materials, stationery, buildings, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition which is flexible and excellent in transparency and a method for producing the same, and the polypropylene resin composition of the present invention is effective in fields such as packaging materials and stationery. It is also available in a wide range of fields such as architecture, home appliances, and automobiles.

[0002]

As a polypropylene resin composition having excellent transparency, a composition containing propylene and a small amount of a copolymer of ethylene and an α-olefin such as butene is known. However, these are disclosed, for example, in JP-A-63-7504.
8, JP-A-63-97648, JP-A-62-11505
As shown in 0, the transparency is maintained by adding the nucleating agent, and the transparency of this substance itself cannot be said to be sufficient. In addition, nucleating agents are generally expensive and may cause odor.

Japanese Patent Laid-Open No. 1-306448 discloses a composition similar to the present invention, which comprises polypropylene and a propylene / ethylene / butene copolymer (hereinafter abbreviated as terpolymer). However, here too, a nucleating agent is an essential component in order to achieve good transparency. It is also described that even if an attempt is made to obtain a flexible composition as in the present invention by increasing the addition amount of the terpolymer, the transparency is lowered as a result.

Japanese Patent Laid-Open No. 64-55241 discloses a film using a composition of polypropylene and a terpolymer. Although the transparency of the composition as a film is not bad at all, it is still insufficient, and it is difficult to obtain a flexible material as in the present invention with the composition.

JP-A-4-266954 discloses a transparent film using a composition comprising 1) a propylene-α-olefin copolymer and 2) a copolymer containing propylene and ethylene and optionally an α-olefin. ing. However, it is difficult to obtain a flexible composition from the composition, and the copolymer 2) corresponding to the component b) of the present invention is used.
It is specified in (1) that those containing no α-olefin are preferable.

JP-A-4-283252 discloses a composition comprising 1) polypropylene, 2) a semi-crystalline copolymer of ethylene, propylene and α-olefin, and 3) a copolymer containing propylene and ethylene and α-olefin. Although a transparent film using is disclosed, its transparency and flexibility are not always sufficient.

JP-A-6-25489 also discloses a composition similar to the present invention, but this is a composition excellent in heat-sealing property, and no information about transparency is described.

[0008]

SUMMARY OF THE INVENTION It is an object to provide a composition having excellent flexibility and transparency as described above.

[0009]

The present inventors have unexpectedly found that a composition comprising a specific polypropylene and a copolymer elastomer having a specific composition and enthalpy of fusion is unexpectedly effective in solving the above problems. The present invention has been completed. That is, the object of the present invention is to provide component a) 10 to 65 parts by weight of polypropylene in which 20% by weight or less of ethylene and / or α-olefin may be copolymerized, and component b) propylene and ethylene and α-olefin. A composition comprising 90 to 35 parts by weight of a polymer elastomer, wherein the component b) has a propylene content of 2
More than 0% by weight and 80% by weight or less, with an ethylene content of 10
More than 45% by weight and α-olefin content is in the range of more than 10% by weight and 45% by weight or less (total content is 100% by weight), and measured by a differential scanning calorimeter, This can be solved by a polypropylene resin composition characterized in that the crystalline component having a peak in the range of 60 to 130 ° C has a melting enthalpy of 20 j / g or less.

The present invention will be described in detail below. Component a) of the invention is polypropylene which may be copolymerized with up to 20% by weight of ethylene and / or α-olefins. The α-olefin has a carbon number of 4 to 12, and may be linear or branched. Specific examples of such α-olefins include 1-butene, isobutene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3 -Methyl-1-pentene, 4-
Methyl-1-pentene, 1-octene, 1-nonene, 1
-Decene, 1-undecene, 1-dodecene and the like, and two or more of these may be used in combination. One of these
-Butene, 1-hexene, 1-octene, 3-methyl-
1-Pentene is preferable, and 1-butene is particularly preferable. When the content of ethylene and / or α-olefin is 20% by weight or more, the heat resistance of the composition is lowered, which is not preferable. It is preferably 15% by weight or less, more preferably 3% by weight or more and 12% by weight or less.

Component b) in the present invention is a copolymer elastomer of propylene with ethylene and α-olefins. The α-olefin has a carbon number of 4 to 12, and may be linear or branched. Specific examples of such α-olefins include 1-butene, isobutene, 1-pentene, 2-methyl-1-butene and 3-.
Methyl-1-butene, 1-hexene, 2-methyl-1-
Pentene, 3-methyl-1-pentene, 4-methyl-1
-Pentene, 1-octene, 1-nonene, 1-decene,
1-undecene, 1-dodecene and the like, and these may be used in combination of two or more kinds. 1-butene of these,
1-Hexene, 1-octene and 3-methyl-1-pentene are preferable, and 1-butene is particularly preferable.

The propylene content in component b) is more than 20% by weight and 80% by weight or less. If it is 20% by weight or less, the transparency of the polypropylene resin composition is insufficient, and if it exceeds 80% by weight, it is soft. Sex decreases. From the balance of transparency and flexibility, the propylene content in component b) is
30% to 70% by weight is preferable, 40% by weight
A range of ˜60% by weight is particularly preferred.

The ethylene content in component b) is 10% by weight
To less than 45% by weight, and if less than 10% by weight, flexibility decreases, and if more than 45% by weight, transparency decreases.
From the balance of transparency and flexibility, the ethylene content in component b) is preferably in the range of 15% by weight to 40% by weight.
The range of 0% to 35% by weight is particularly preferable. Component b)
The α-olefin content in the range is in the range of more than 10% by weight and 45% by weight or less. When it is less than 10% by weight, flexibility decreases, and when it exceeds 45% by weight, transparency decreases. From the balance of transparency and flexibility, the α-olefin content in component b) is preferably in the range of 15% by weight to 45% by weight,
A range of wt% to 40 wt% is particularly preferred. The total content of each of propylene, ethylene and α-olefin in the component b) is 100% by weight.

From the viewpoint of flexibility, it is preferable that the propylene content fb (% by weight) and the α-olefin content fo (% by weight) satisfy the following relationships, particularly in the composition range of the component b). 0.25≤fb / (fb + fo),
More preferably, 0.35≤fb / (fb + fo).

From the viewpoint of transparency, it is preferable that the propylene content fb (% by weight) and the α-olefin content fo (% by weight) satisfy the following relationships, particularly in the composition range of the component b). fb / (fb + fo) ≤0.75,
More preferably, fb / (fb + fo) ≤0.65.

Therefore, the range in which both flexibility and transparency are particularly excellent is in the following cases: 0.25≤fb / (fb + fo) ≤0.75 More preferably, the following relationship is satisfied. 0.35≤fb / (fb + fo) ≤0.65

In the component b) of the present invention, the melting enthalpy of the crystalline component having a peak in the range of 60 to 130 ° C., measured by a differential scanning calorimeter (dsc), is 20.
It should be j / g or less. Only by using an elastomer having such specific properties, a composition excellent in both flexibility and transparency can be obtained. A particularly preferable value is 10 j / g or less, and a most preferable range is 5 j / g or less. In measuring the enthalpy of fusion, it is necessary to measure only component b). This is because the melting peak of the component a) overlaps with that of the component b) and an accurate value may not be measured. In the case of a composition obtained by multistage polymerization, the measurement may be performed on a sample obtained by performing only the polymerization at the stage corresponding to the production of component b). However, when it is difficult to directly measure the melting enthalpy of the component b) or when the melting enthalpy of the component a) is known, the melting enthalpy ΔH of the component b) can be calculated according to the following formula. ΔH = (ΔHt −X · ΔHa) / (1-X) where ΔHt is the value of the enthalpy of fusion obtained by measuring the entire composition consisting of component a) and component b), and X is the component a ), ΔHa is the value of the enthalpy of fusion of component a). As the dsc, a commercially available device can be preferably used, and usually 20
The measurement is performed at a temperature rising rate of ° C / min.

As a result of the study conducted by the present inventors, the transparency of the composition is greatly influenced by the transparency of the component b) alone.
It has been found that the transparency of component b) is improved only in the above mentioned composition range. That is, in the component b) of the present invention, the haze value obtained by the method described below is preferably 30% or less. The value is more preferably 20% or less.

Next, the proportions of component a) and component b) in the polypropylene resin composition of the present invention will be described. The proportion of component a) in the present invention is in the range of 10 parts by weight to 65 parts by weight based on 100 parts by weight of the total of components a) and b). If the amount of component a) is less than 10 parts by weight, the heat resistance of the polypropylene resin composition will be reduced, and if it exceeds 65 parts by weight, the flexibility will be insufficient. A preferable range in terms of balance between heat resistance and flexibility is 20 to 60 parts by weight,
Particularly in the range of 30 parts by weight to 50 parts by weight, a composition having good flexibility can be obtained while maintaining heat resistance.

Another aspect of the present invention is a polypropylene-based resin composition obtained by adding 0.001 to 5 parts by weight of an organic peroxide to 100 parts by weight of the above components a) and b) and heat-treating. is there. This aspect has the following meaning. That is, in the polymerization of the components a) and b), by producing as high a molecular weight as possible, mutual adhesion of the powders is suppressed, and as a result, production obstacles such as line clogging can be easily avoided. Like
Therefore, it is a preferred method to produce a high molecular weight component a) and a component b) by polymerization, and then reduce the molecular weight to a desired molecular weight to impart fluidity.

In general, a composition such as the present invention containing a large amount of an ethylene / propylene copolymer elastomer or an elastomer similar to the ethylene / propylene copolymer elastomer often causes intermolecular crosslinking due to an organic peroxide, resulting in a decrease in fluidity. Therefore, the application of this method was possible only under very limited conditions. However, since the polypropylene resin composition of the present invention contains an elastomer similar to the ethylene / propylene copolymer elastomer, since an elastomer having a specific composition is used, this method can be preferably adopted. .

As the organic peroxide used here, commercially available products can be used, for example, dibenzoylperoxide.
Oxide, p-chlorobenzoylper-oxide, dicumylper-oxide, di-t-butylperoxide, t-butylcumylperoxide, 1,3-bis (t-butylperoxy) isopropylbenzene, 2,
5-bis (t-butylperoxy) -2,5-dimethylhexane, 2,5-bis (t-butylperoxy)-
2,5-dimethyl-3-hexyne, 1,1-bis (t-
Butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, and the like, and mixtures thereof. These may be diluted with a plasticizer or an inert substance such as calcium carbonate or white carbon. The compounding amount is 0.001 to 5 parts by weight based on 100 parts by weight in total of the components a) and b).
If it is less than 0.001 part by weight, the effect of the compounding is not seen, and if it exceeds 5 parts by weight, the effect is not further improved and problems such as coloring and generation of odor occur. The preferred range of blending is 0.005 to 2 parts by weight, and more preferably 0.01 to 0.5 parts by weight.

The method of heat treatment is as follows: component a) and component b)
It is preferable to blend an organic peroxide with and heat-treat dynamically with a kneader such as an extruder or a Banbury mixer. Further, a method of blending the component a) and the component b) with an organic peroxide and subjecting it to a static heat treatment as it is, or a method of subjecting it to a heat treatment with an organic peroxide in a solution is also possible. When blending the organic peroxide, a mixer such as a Henschel mixer or a tumbler mixer can be preferably used. A method of impregnating the composition with a solvent in which an organic peroxide is dissolved and then removing the solvent is also possible. Although the temperature of the heat treatment depends on the decomposition temperature of the organic peroxide used, it is generally between 50 ° C and 300 ° C.
It is preferably in the range of (t-50) ° C to (t + 70) ° C, more preferably (t-30) ° C to (t +), where t is the temperature at which the half-life of the organic peroxide used is 1 minute.
50) C. in the range.

The melting enthalpy of the crystalline component having a peak in the range of 60 to 130 ° C., measured by dsc of component b) in this mode, is preferably in the same range as in the above-mentioned mode, but in this mode transparency and flexibility are obtained. This is not only because of the good property, but also because the effect of blending an organic peroxide and heat treatment is extremely large, and the fluidity can be easily improved. The ratio of component a) and component b) in this mode is in the range of 10 parts by weight to 65 parts by weight based on 100 parts by weight of the total of components a) and b). If the amount of component a) is less than 10 parts by weight, the heat resistance of the polypropylene resin composition will be reduced, and if it exceeds 65 parts by weight, the flexibility will be insufficient. A preferable range in terms of balance between heat resistance and flexibility is 20 to 60 parts by weight, and particularly 30
In the range of 50 parts by weight to 50 parts by weight, a composition having good flexibility can be obtained while maintaining heat resistance.

The present invention may contain components such as fillers, softening agents and additives within the scope of the present invention. Examples of the filler include calcium carbonate, talc, silica, kaolin, clay, diatomaceous earth,
Examples thereof include calcium silicate, asbestos, mica, alumina, aluminum sulfate, barium sulfate, calcium sulfate, magnesium carbonate, carbon fiber, glass fiber, glass sphere, molybdenum sulfide, graphite, and shirasu balloon. Examples of the softening agent include commercially available process oil and the like. These may be added for the purpose of promoting plasticization or improving the fluidity of the resulting composition. These may be paraffin-based, naphthene-based, or aromatic-based, but paraffin-based ones are particularly preferable because of good color tone and weather resistance. The additives include heat resistance stabilizers, weather resistance stabilizers, colorants, antistatic agents, flame retardants, lubricants, slip agents, antiblocking agents and the like. As the heat resistance stabilizer, known compounds such as phenol type, phosphorus type and sulfur type can be used. As the colorant, carbon black, titanium white, zinc white, red iron oxide, azo compound,
Examples thereof include nitroso compounds and phthalocyanine compounds. Known antistatic agents, flame retardants, lubricants, slip agents, antiblocking agents and the like can be used. The composition of the present invention shows good transparency even if it does not contain a nucleating agent, but the use of a nucleating agent is not excluded.

The method for producing the polypropylene resin composition of the present invention will be described below. The polypropylene resin composition of the present invention may be prepared by mixing component a) and component b) and then mixing them (blending method), but it is particularly preferred that the polypropylene resin composition is prepared by multistage polymerization. It is one of the characteristics of the thermoplastic resin composition of the present invention that it can be produced by multistage polymerization, as described in the section of the polymerization catalyst described later. When it is produced by multistage polymerization, the component a)
And the component b) have good miscibility, and mechanical properties such as transparency and strength are remarkably improved as compared with the blending method.

The term "multistage polymerization" as used herein refers to the production of component a) and component b) in successive separate steps, for example, after the polymerization of component a), a further polymerization catalyst is added in the presence of component a). To polymerize component b) without doing so. The order of multi-stage polymerization is as follows: component a) or component b)
It is possible to polymerize either of the above first, but it is desirable to polymerize component a) followed by polymerization of component b). In general, a flexible composition often suffers from an obstacle due to flexibility such as line clogging due to mutual adhesion of powders in the manufacturing process. However, the polypropylene resin composition of the present invention can be manufactured by following the above procedure. It is possible to manufacture without such obstacles. Further, since the obtained powder is easy to handle, it can be directly used, for example, for forming a sheet or film without pelletizing.

There is no particular limitation on the number of stages of the multistage polymerization. For example, the component a) is polymerized in two stages and then the component b) is polymerized, or after the component a) is polymerized, the component b) is divided into two stages. It is also possible to carry out a total of three stages of polymerization. Each polymerization method in the multi-stage polymerization, solution polymerization or slurry polymerization performed in the liquid phase of the monomer in the presence or absence of an inert solvent,
Known methods such as gas phase polymerization performed in a gas phase monomer are possible. Of these, it is desirable to employ gas phase polymerization for component b). The use of gas phase polymerization enables production under mild polymerization conditions and facilitates the control of the content of component b). The polymerization temperature is generally in the range of 20 ° C to 100 ° C, preferably 40 ° C to 80 ° C.
The pressure is generally in the range of atmospheric pressure to 1000 psi in the liquid phase polymerization, and atmospheric pressure to 600 psi in the gas phase. An appropriate range of these conditions can be selected in consideration of the properties and productivity of the polypropylene resin composition to be obtained.

The polymerization catalyst used when producing the polypropylene resin composition of the present invention will be described. Known polymerization catalysts can be used as the polymerization catalyst in the present invention, which is unexpected in the following points. That is, in producing a polypropylene resin composition, a catalyst containing Ti as an essential component (hereinafter abbreviated as Ti catalyst) is often used. It is generally known that when a copolymer elastomer is obtained with such a Ti-based catalyst, its transparency is very low, and this tendency is particularly remarkable in a flexible elastomer containing an ethylene component. is there. However, the component b) of the present invention exhibits good transparency even when produced with a Ti-based catalyst, and as a result, the polypropylene-based resin composition of the present invention having good transparency and flexibility can be obtained. . This is one of the unexpected features of the present invention.

Further, since the component b) has the characteristics as described above, the polypropylene resin composition of the present invention can be prepared by blending the components a) and b) with different catalysts. Instead, it can be produced by multistage polymerization. That is, after the polypropylene of the component a) is produced by the Ti-based catalyst used for ordinary polypropylene production, the elastomer component b) having excellent transparency can be produced subsequently without using a new catalyst.

Examples of such Ti-based catalysts include those comprising a solid titanium catalyst component (A), an organoaluminum compound (B) and an electron donor catalyst component (C). The solid titanium catalyst component (A) is a highly active catalyst component containing magnesium, titanium, halogen and an electron donor as essential components. Such a solid titanium catalyst component (A) is prepared by contacting the following magnesium compound, titanium compound and electron donor. Examples of the titanium compound used for preparing the solid titanium catalyst component in the present invention include Ti
(OR) _n X _4-n (R is a hydrocarbon group, X is a halogen atom, and a tetravalent titanium compound represented by 0 <n <4) can be mentioned.

Specifically, TiCl ₄ , TiBr ₄ , T
Tetrahalogenated titanium such as iI ₄ , Ti (OCH ₃ )
_{Cl 3, Ti (OC 2 H} 5) Cl 3, Ti (n-OC 4
_{H 9) Cl 3, Ti (} iso-OC 4 H 9) Cl 3, T
i (OCH ₃ ) Br ₃ , Ti (OC ₂ H ₅ ) Br ₃ , T
i (n-OC ₄ H ₉ ) Br _{3 and} other trihalogenated alkoxy titanium, Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OC _{2
H 5) 2 Cl 2, Ti} (n-OC 4 H 9) 2 Cl 2, T
i (OCH ₃ ) ₂ Br ₂ , Ti (OC ₂ H ₅ ) ₂ Br
_{2, Ti (n-OC 4} H 9) such as ₂ Br ₂ dihalogenated dialkoxy _{titanium, Ti (OCH 3) 3 Cl} , Ti
(OC ₂ H ₅ ) ₃ Cl, Ti (n-OC ₄ H ₉ ) ₃ C
1, Ti (OCH ₃ ) ₃ Br, Ti (OC ₂ H ₅ ) ₃ B
monohalogenated trialkoxy titanium such as r, Ti (n-OC ₄ H ₉ ) ₃ Br, Ti (OCH ₃ ) ₄ , Ti (O
_{C 2 H 5) 4, Ti} (n-OC 4 H 9) 4, Ti (is
Examples thereof include tetraalkoxytitanium such as o-OC ₄ H ₉ ) ₄ . Among these, a halogen-containing titanium compound, particularly a titanium tetrahalide, is preferred. These titanium compounds may be used alone or in combination of two or more. Further, these titanium compounds may be diluted with a hydrocarbon compound or a halogenated hydrocarbon compound.

In the present invention, the solid titanium catalyst component (A)
Examples of the type of magnesium compound used in the preparation include a reducing magnesium compound and a non-reducing magnesium compound. Here, examples of the magnesium compound having a reducing property include a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond. Specific examples of such compounds include dimethyl magnesium, diethyl magnesium, dipropyl magnesium,
Dibutyl magnesium, dipentyl magnesium, dihexyl magnesium, didecyl magnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, pentyl magnesium chloride, hexyl magnesium chloride, ethyl magnesium ethoxide, butyl magnesium ethoxide, ethyl butyl magnesium, etc. Can be. These compounds can be used alone or in combination of two or more, and may form a complex compound with an organoaluminum compound described later. Examples of non-reducing magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide and magnesium iodide, alkoxy magnesium such as ethoxy magnesium, isopropoxy magnesium, butoxy magnesium, magnesium stearate and magnesium salts such as magnesium laurate. Can be mentioned.

Examples of the electron donor used for preparing the solid titanium catalyst component (A) include organic carboxylic acid esters and polyvalent carboxylic acid esters. Examples thereof include aliphatic polyhydric acids such as malonic acid, methyl malonic acid, succinic acid, methyl succinic acid, glutaric acid, itaconic acid, maleic acid, citraconic acid, 1,2-cyclohexanecarboxylic acid, tetrahydrophthalic acid, and nadic acid. Examples include alkyl and aryl esters of polyvalent carboxylic acids, and alkyl and aryl esters of aromatic polycarboxylic acids such as phthalic acid, naphthalenedicarboxylic acid, trimellitic acid, and furandicarboxylic acid. Specific examples of these include diethyl succinate, dibutyl succinate, diethyl methyl succinate,
α-Methylglutarate diisobutyl, diethyl malonate, diethyl methylmalonate, diethyl ethylmalonate, diethyl isopropylmalonate, diethyl butylmalonate, diethyl phenylmalonate, diethyl allylmalonate, diethyl diethylmalonate, diethyl diisobutylmalonate, Di-n-butyl malonate diethyl, diisobutyl maleate, diisooctyl maleate, diethyl butyl maleate, diisobutyl butyl maleate, diisopropyl β-methyl glutarate, dimethyl phthalate, diethyl phthalate, methyl ethyl phthalate, ethyl phthalate. n-butyl, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di2-ethylhexyl phthalate, di-n-heptyl phthalate, lid Didecyl acid salt, benzyl n-butyl phthalate, diphenyl phthalate, diethyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate,
Examples thereof include triethyl trimellitate and dibutyl trimellitate. Among these, phthalic acid, maleic acid, substituted malonic acid and an ester consisting of an alkyl group having 2 or more carbon atoms are preferable, and an ester consisting of phthalic acid and an alkyl group having 2 or more carbon atoms is particularly preferable.

The electron donors other than polyvalent carboxylic acid which can be used in preparing the solid titanium catalyst component (A) include alcohols, amines, amides, as described below.
Organosilicon compounds such as ethers, carboxylic acids, acid anhydrides, acid halides, esters, ketones, aldehydes, nitriles, phosphines, stibines, arsines, and alkoxysilanes, Periodic Table I ~ Group IV metal amides, salts and the like.

The organoaluminum compound (B) used in the present invention is a compound having at least one Al-carbon bond. Specifically, triethylaluminum, trialkylaluminums such as triisobutylaluminum, diethylaluminum chloride, dibutylaluminum chloride, dialkylaluminum halide such as diethylaluminum bromide, ethylaluminum sesquichloride, aluminum sesquichloride such as dibutylaluminum sesquichloride, ethyl Partially halogenated alkyl aluminum, such as aluminum dichloride, butyl aluminum dichloride, ethyl aluminum bromide, etc., such as diethyl aluminum hydride, dibutyl aluminum hydride, ethyl aluminum dihydride, propyl aluminum dihydride, butyl aluminum dihydride, etc. Alkyl aluminum, partially hydrogenated, diethyl Aluminum ethoxide, partially alkoxylated alkyl aluminum such as dibutyl aluminum ethoxide, (C
_{2 H 5) 2 Al-O} -Al (C 2 H 5) 2, (C 4 H
_{9) 2 Al-O-Al} (C 4 H 9) 2, (C 2 H 5) 2
_{Al-N (C 2 H 5} ) -Al (C 2 H 5) 2, an organic aluminum compound by combining a plurality of aluminum by a heteroatom such as methylaluminoxane, LiAl (C ₂ H
₅ ) ₄ , complex compounds with Group I metals such as LiAl (C ₇ H ₁₅ ) _{4 and the} like. Among these, trialkylaluminums and organoaluminum compounds in which a plurality of aluminums are bound by a hetero atom are particularly preferable.

As the electron donor catalyst component (C), alcohols, phenols, carboxylic acids, acid anhydrides, acid halides, esters, amides, aldehydes, ketones, ethers, amines, Examples thereof include nitriles and organic silicon compounds. Of these, esters such as methyl formate, ethyl acetate, methyl benzoate, ethyl benzoate and polyvalent carboxylic acid esters as described above,
Organosilicon compounds such as diphenyldiethoxysilane, dicyclohexyldimethoxysilane, methyl-t-butyldimethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane and phenyltrimethoxysilane are particularly preferred.

It is possible to carry out a prepolymerization in which the catalyst is contacted with a small amount of olefin prior to the polymerization of components a) and b) according to the invention. Prepolymerization is preferable in that the catalyst activity is improved and the obtained polypropylene resin composition becomes a powder having a property that is easy to handle. The prepolymerization is carried out by adding the catalyst and a small amount of olefin in a hydrocarbon solvent or in a liquid phase or a gas phase of olefin in an amount of 0.5 to 5% by weight of the catalyst.
It is carried out by contacting for a sufficient time so that a double amount of the polymer can be obtained. Here, for example, hexane or heptane can be used as the hydrocarbon solvent. The olefin may be the same as or different from the monomer used for the polymerization. Examples of such olefins include ethylene, propylene, 1-butene, 1-hexene and the like.

[0039]

The present invention is described in detail below with reference to examples, but the present invention is not limited to these examples without departing from the spirit of the invention. (Shore hardness) Measured according to ASTM D225. (Haze) Measured according to JIS K7105. (Measurement of amount of monomer in each component) Infrared spectroscopic analysis was performed. (Measurement of Melting Enthalpy) It was measured at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter DSC7 manufactured by Perkin Elmer.

Examples 1 to 6 1) Polymerization catalyst (Preparation of solid titanium catalyst component) A 200 ml three-necked flask equipped with a thermometer and a stirrer was sufficiently replaced with nitrogen,
Diethoxy magnesium 1.11 g (9.47 mmo
1), 10 ml of toluene and 0.46 ml (1.73 mmol) of di-n-butyl phthalate were charged, and 70 ° C
Stir for 2 hours. After that, it is cooled to room temperature and TiCl ₄ 5 is added.
0 ml is added dropwise from the dropping funnel over 1 hour. After the dropping is completed, the temperature is raised to 110 ° C. and the reaction is performed for 2 hours while stirring. After completion of the reaction, the mixture was cooled to room temperature, washed with 200 ml of n-hexane several times, and dried under reduced pressure at 50 to 60 ° C. for 20 to 30 minutes to obtain a solid titanium catalyst component. (Preparation of polymerization catalyst) To 10 mg of the solid titanium catalyst component prepared above, 1.5 mmol of triethylaluminum
And cyclohexylmethyldimethoxysilane 0.3m
Mol was added to prepare a catalyst.

2) Production of component a) 8 mol of propylene and 730 ml of hydrogen (volume at normal pressure) were introduced into an autoclave having an internal volume of 1.5 L equipped with a magnetic stirrer. After the internal temperature of the autoclave reached 70 ° C., ethylene and a catalyst were charged to start the polymerization, and the polymerization was performed for a predetermined time. The ethylene was continuously introduced so as to maintain the total pressure shown in Table 1.

3) Manufacture of component b) After carrying out the procedure described in the manufacture of component a) above, all the gas in the autoclave was removed and the autoclave was cooled to 30%.
It was cooled to a temperature below ° C. Butene and propylene were introduced into this autoclave, and the temperature was quickly raised to 50 ° C. After reaching 50 ° C., ethylene was continuously supplied to carry out polymerization so that a predetermined total pressure was obtained. After a lapse of a predetermined time, methanol was pressed into the autoclave to stop the polymerization. After removing all the gases, the intended polypropylene resin composition was obtained.

EXAMPLE 7 Propylene 6 mol and butene 2 in the production of component a)
It carried out like Example 1-6 except having used mol.

Example 8 The procedure of 1 to 6 was repeated except that 1-hexene was used in place of butene in the preparation of component b).

Examples 9-10 Examples 1-10 except that the preparation of component b) was carried out by the following method:
It carried out similarly to 6. After carrying out the procedure described for the production of component a) above, all the gas in the autoclave was removed. Gases of ethylene, propylene and butene were continuously supplied to the autoclave to carry out polymerization in a gas phase.

Example 11 No hydrogen was used in the preparation of component a),
A composition was prepared in the same manner as in Example 6. This composition 100
2,5-bis (t-butylperoxy) based on parts by weight
-2,5-Dimethylhexane (trade name Kayahexa AD,
Kayaku Akzo Co., Ltd.) (0.02 parts by weight) was blended, melt-kneaded with a single screw extruder at 200 ° C., and heat-treated.

Example 12 No hydrogen was used in the preparation of component a),
A composition was prepared in the same manner as in Example 9. This composition 100
2,5-bis (t-butylperoxy) based on parts by weight
-2,5-Dimethylhexane (trade name Kayahexa AD,
Kayaku Akzo Co., Ltd.) (0.02 parts by weight) was blended, melt-kneaded with a single screw extruder at 200 ° C., and heat-treated.

Comparative Examples 1 and 2 The procedure of Example 1 was repeated except that the production conditions of the component b) were changed to those shown in Table 1.

Comparative Example 3 The procedure of Example 1 was repeated except that the polymerization time of each component was changed to the time shown in Table 1.

Comparative Example 4 Component b) was prepared in the same manner as in Example 11 except that the conditions shown in Table 1 were changed.

The details of the production conditions are shown in Table 1, and the characteristics of the obtained polypropylene resin composition are shown in Table 2.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

According to the present invention, a polypropylene resin composition having flexibility and excellent transparency can be obtained by using an elastomer component having specific properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Ichizo Futagi, Oita City, Oita Prefecture, No. 2 Nakasu, Showa Denko K.K.

Claims (8)

[Claims] 1. Component a) 10 to 65 parts by weight of polypropylene which may be copolymerized with 20% by weight or less of ethylene and / or α-olefin, and component b) a copolymer of propylene and ethylene and α-olefin. A composition comprising 90 to 35 parts by weight of an elastomer, wherein the component b) has a propylene content of more than 20% by weight and 80% by weight or less, and an ethylene content of more than 10% by weight and 45% by weight or less α-olefin content. Is in the range of more than 10% by weight and 45% by weight or less (the total of the respective contents is 100% by weight), and melting of the crystalline component having a peak in the range of 60 to 130 ° C. measured by a differential scanning calorimeter. Enthalpy is 2
A polypropylene-based resin composition, which is 0 j / g or less. 2. The polypropylene resin composition according to claim 1, wherein the haze value of the component b) is 30% or less. 3. The polypropylene resin composition according to claim 1, wherein the component b) is produced by using a catalyst containing titanium as an essential component. 4. Component a) and component b) according to claim 1.
To 100 parts by weight in total, and 0.001 to 5 parts by weight of an organic peroxide c) is further added, and a heat treatment is performed on the polypropylene resin composition. 5. The polypropylene resin composition according to claim 4, wherein the haze value of the component b) is 30% or less. 6. The polypropylene resin composition according to claim 4, wherein the component b) is produced by using a catalyst containing titanium as an essential component. 7. The method according to claim 1, further comprising the step of producing the components a) and b) by multistage polymerization.
A method for producing the polypropylene resin composition according to any one of 1. 8. The method for producing a polypropylene resin composition according to claim 7, wherein the component b) is produced by gas phase polymerization.