JP2000143933A - Polypropylene-based composition for calendering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polypropylene-based composition inexpensive, excellent in calendering and comparable to soft and semihard polyvinyl chloride, and to obtain a polypropylene-based film and sheet using the composition. SOLUTION: This polypropylene-based composition for calendering comprises a propylene-based block copolymer component comprising a crystalline polypropylene and a copolymer of propylene and αolefin. An intrinsic viscosity [η]RC of the copolymer of the block copolymer component is <=6.5 dl/g, an intrinsic viscosity ratio [η]RC/[η]PP between the copolymer and crystalline polypropylene is 0.5 to 3.0, and the product ([η]RC/[η]PP)×(WPP/WRC) of the ratio of [η]RC/[η]PP and weight ratio WPP/WRC of the crystalline polypropylene to the copolymer is 0.2 to 7.0. The melt flow rate is 0.1 g/10 min. to 3.5 g/10 min. (230 deg.C, 21.18 N). The width of process temperature Δt in calendering is >=30 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene composition, a film and a sheet using the same, and more particularly to a polypropylene composition to which calendering, which is a method for processing soft and semi-rigid polyvinyl chloride, can be applied. Composition,
And films and sheets obtained by calendering.

[0002]

2. Description of the Related Art Soft and semi-rigid polyvinyl chloride is processed into various films or sheets by a calendering method having a high yield and extremely high productivity due to its proper processing, and is used as a building material, furniture, home appliances, stationery and automobile. It has been used for leather such as interior materials and decorative films or sheets. However, in recent years, various alternatives have been studied since they may become a source of hydrogen chloride during incineration.
A polypropylene composition that does not generate toxic gas even when incinerated is regarded as promising as an alternative resin for soft / semi-hard vinyl chloride.

However, polypropylene is unsuitable for a calendering method which has a high yield and a remarkably high productivity because of its melt viscosity property, and cannot be calendered because it causes sticking even in a calendering machine. In order to solve these problems, it has been conventionally performed to add a large amount of an inorganic filler to polypropylene to impart surface activity to a calender roll to impart calendering workability. However, with this method,
Addition of inorganic fillers increases rigidity, making it not only impossible to use in soft or semi-rigid fields, but also not being able to obtain transparency or causing whitening when folding sheets or films, leather, decoration It could not be used in the field of films and sheets for automobiles.

On the other hand, in order to impart calenderability to polypropylene without blending an inorganic filler, ethylene-polyethylene having a specific melt index and a specific molecular weight distribution is used.
A resin composition containing an α-olefin copolymer, an ethylene-α-olefin copolymer rubber, and polypropylene is disclosed in JP-A-51-97649. The olefin copolymer is blended in a large amount so that calendering properties can be imparted, and there is a problem that not only softening is excessive but also heat resistance of polypropylene is sacrificed.

Also, the present applicants have argued that they can be sufficiently used as a soft / semi-hard polyvinyl chloride substitute resin.
JP-A-8-27238, WO97 / 19135 and JP-A-10-316810 propose a propylene-based block copolymer excellent in transparency and whitening resistance.

[0006]

However, although the propylene-based block copolymer proposed by the present applicant has excellent characteristics as described above, the film or sheet is produced using a calendering machine. When the film was formed, the workability for calendering was not sufficient, and it was found that there was room for improvement. The present invention has been made in view of such problems of the prior art, and it is an object of the present invention to provide a low-cost, excellent calendering processability and a polypropylene-based composition comparable to soft / semi-rigid polyvinyl chloride. Articles, polypropylene-based films and sheets.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that the above object can be achieved by using a propylene-based block copolymer having a specific composition. Thus, the present invention has been completed.

That is, the polypropylene composition of the present invention is a polypropylene composition for calendering comprising a propylene block copolymer component containing a copolymer of crystalline polypropylene and a propylene-α-olefin, The intrinsic viscosity [η] _RC of the copolymer in the block copolymer component is 6.5 dl / g or less, and the intrinsic viscosity ratio [η] _RC / [η] _{PP of the} copolymer and the crystalline polypropylene is 0.5 to less. At 3.0, the product of this intrinsic viscosity ratio [η] _RC / [η] _PP and their weight ratio W _PP / W _RC ([η] _RC / [η] _PP ) × (W _PP / W _RC ) Is 0.2
~ 7.0, and the melt flow rate is 0.1 g / 10
min to 3.5 g / 10 min (230 ° C, 21.18
N).

Further, the polypropylene film of the present invention is obtained by calendering the above-mentioned polypropylene composition, and the polypropylene sheet of the present invention comprises the above-mentioned polypropylene composition. It is characterized by being obtained by calendering.

[0010]

Although the details of the polypropylene composition of the present invention exhibiting excellent properties, especially exhibiting calenderability, are not always clear, it is presumed as follows at present. That is, the polypropylene composition of the specific composition of the present invention has a viscosity ratio and weight of the crystalline polypropylene and the propylene-α-olefin copolymer within a specific range, and the fluidity of the polypropylene composition, that is, the MFR is specific. Within this range, the balance between the melt fluidity of the copolymer component and the crystalline polypropylene is appropriate for calendering, and the entire polypropylene composition can be used in a wide range of processing temperatures required for calendering. It is considered that the adhesiveness does not appear over the entire range. Further, the polypropylene composition in the specific range according to the present invention also has physical properties such as whitening resistance, which are almost equal to those of the soft / semi-hard polyvinyl chloride resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the polypropylene composition of the present invention will be described in detail. As described above, the polypropylene-based composition of the present invention contains a propylene-based block copolymer component, and the block copolymer component is a crystalline polypropylene that is a crystalline component of a propylene homopolymer or a propylene-α-olefin. And a propylene-α-olefin copolymer.

Here, as the propylene homopolymer in the crystalline polypropylene of the block copolymer component, a high crystallinity (stereoregularity) having an isotactic pentad fraction P of 0.95 or more, particularly 0.955 or more, is used. ) It is preferred to use polypropylene. The isotactic pentad fraction P affects the heat resistance of the propylene-based block copolymer component, and further, the mechanical properties such as the heat resistance of the present composition. Becomes larger. Further, as the crystalline polypropylene, a propylene-α-olefin random copolymer having a propylene content of 90 to 99% by weight based on the weight of the propylene homopolymer or the crystalline polypropylene can be preferably used.

On the other hand, as the propylene-α-olefin copolymer, an ethylene-propylene random copolymer containing 20 to 55% by weight, preferably 25 to 50% by weight of ethylene polymerization units based on the whole copolymer is preferably used. Can be. The amount of ethylene polymerized units affects the stiffness and impact resistance of the block copolymer component, especially the impact resistance at low temperatures. The larger the amount, the better the impact resistance. Since the dispersibility in the functional polypropylene may be affected and the mechanical properties such as the tear strength of the present composition may be reduced, it is preferable to adjust the composition to the above range.

In the above copolymer, the intrinsic viscosity [η] _RC measured in tetralin at 135 ° C. is 6.5 dl /
g and the intrinsic viscosity ratio [η] of crystalline polypropylene to intrinsic viscosity [η] _PP measured under the same conditions [η] _RC /
[Η] _PP is 0.5 to 3.0. At this time, since the intrinsic viscosity [eta] _RC of the copolymer can not be measured directly, an intrinsic viscosity [eta] _PP and propylene block copolymer component overall intrinsic viscosity directly measurable crystalline polypropylene [eta]
_{From WHOLE} and copolymer content W _RC (% by weight),
It is calculated based on the following equation. _{[Η] RC = {[η} ] WHOLE - (1-W RC / 100) [η] PP} / (W RC / 100) ...

The intrinsic viscosity [η] _RC of the copolymer affects mechanical properties such as film forming property and flexibility of the present composition, and the intrinsic viscosity ratio [η] _RC / [η] _PP is determined by the crystallinity of the copolymer. Affects dispersibility in polypropylene. Intrinsic viscosity [η] _RC
The larger the value is, the more the mechanical properties are improved, but the rigidity of the propylene-based block copolymer is increased, and the flexibility of the present composition is impaired. On the other hand, if the intrinsic viscosity ratio [η] _RC / [η] _PP is too large or too small, the impact resistance at low temperature is insufficient, and if too large, the effect of improving the molding shrinkage decreases. It is necessary to control [η] _RC and intrinsic viscosity ratio [η] _RC / [η] _PP within the above ranges.

In the present composition, the weight ratio W _PP / W _RC between the crystalline polypropylene and the copolymer is calculated by multiplying the above-mentioned intrinsic viscosity ratio of both components by ([η] _RC / [η] _PP ) × (W _PP /
W _RC) takes a value such as to satisfy the 0.2 to 7.0. The product of the polymer component ratio and the intrinsic viscosity ratio is an index that indicates the molding shrinkage of the block copolymer component, and thus the molding shrinkage of the present composition.When the value decreases, the molding shrinkage ratio is improved. Heat resistance and rigidity are greatly reduced. On the other hand, if it is too large, the desired effect of improving the molding shrinkage cannot be obtained.

The polypropylene composition of the present invention has a melt flow rate (MFR) of 0.1 to 3.5 g /
10 minutes. When the MFR is less than 0.1 g / 10 min, the processing temperature range during calendering is widened, but the processing temperature itself is too high, and the calendering of the steam heating method conventionally used for soft and semi-rigid polyvinyl chloride is used. In the machine, the surface transfer becomes worse, so that a molded article having good appearance cannot be obtained. 3.5g / 10min
If it exceeds, the processing temperature width becomes too narrow, and sticking to the calender roll occurs, making it impossible to form a film.

The specific composition of the above block copolymer component is 15 to 15 with respect to the entire copolymer component.
50% by weight, preferably 20 to 40% by weight of copolymer and 85 to 50% by weight, preferably 80 to 60% by weight of crystalline polypropylene. The block copolymer component preferably has a narrow-dispersion molecular weight distribution with a Q value (Mw / Mn) of 5 or less, preferably 4.5 or less. If the molecular weight distribution increases so that the Q value exceeds 5, the gloss of the composition may decrease, which is not preferable.

As described above, the composition of the present invention is a polypropylene composition containing the propylene-based block copolymer component described above, and the composition has physical properties comparable to polyvinyl chloride. Furthermore, unlike conventional polypropylene resins, they do not exhibit tackiness in a wide processing temperature range and can be subjected to calendering.

The present inventors have examined the possibility of application to such a calendering process, and found that the following processing temperature range Δt (° C.) = Adhesion occurrence temperature−surface transfer failure temperature ... (where “adhesion occurrence temperature” "Is the temperature at which the paper could not be peeled off due to sticking to the roll in the calendering machine." The surface transfer failure temperature "means that the molten sheet on the roll was observed and the sheet surface did not become a smooth mirror surface. It was found that the applicability to calendering can be determined by measuring the processing temperature width Δt represented by (indicating the temperature at which the transfer state became defective). The polypropylene composition of the present invention has a Δt of 30 ° C. or more, preferably 35 ° C.
This is relatively large as described above, and is excellent in such calendering workability.

In the above formula, the temperature at which sticking occurs is typically 210 to 250 ° C., and the surface transfer failure temperature is typically 160 to 180 ° C. Further, when the processing temperature width Δt is 30
If the temperature is lower than ℃, the steam heating type calendering machine conventionally used for soft and semi-rigid polyvinyl chloride is not preferable because the temperature controllable width is narrow and the calendering machine becomes difficult to control the temperature. . Note that, for reference, Δt of polyvinyl chloride is 40 ° C. or more, which also indicates that the polypropylene composition of the present invention has a calendering property comparable to polyvinyl chloride.

The polypropylene composition of the present invention contains the above-mentioned propylene block copolymer as an essential component. However, as long as the calenderability intended by the present invention is not impaired, various additions may be made. An agent can be compounded. As an example of such an additive, a lubricant generally used for calendering can be cited to assist workability during calendering.

When the polypropylene composition of the present invention is calender-molded, the lubricant imparts fluidity to the melt while maintaining a certain degree of compatibility with the molten polypropylene composition. It functions to prevent sticking and facilitate processing. The lubricant is
It may be blended in advance with the present polypropylene composition, or may be blended with the present polypropylene composition during calendering. In addition, the compounding quantity of a lubricant is not specifically limited, However, 0.01 to 5 weight part is typically suitable with respect to 100 weight part of this polypropylene type composition. If the amount is too large, plate-out to a calender roll may occur, and this may be transferred to a molded product to deteriorate the appearance.

The lubricant is not particularly limited as long as it fulfills the above-mentioned functions, but may be a higher paraffinic hydrocarbon, a higher alcohol, or a higher fatty acid-based material such as a higher fatty acid, a higher fatty acid metal salt, a fatty acid amide, or the like. Lower alkyl esters of higher fatty acids can be mentioned,
As raw materials, aliphatic monohydric alcohols (lower alcohols), aliphatic polyhydric alcohols (polyols), and esters of fatty acids and polyglycols can also be used. Further, a composite lubricant containing aromatic carboxylic acid phthalic diamide, phthalic ester, silicone (silicon resin), natural and synthetic rosin, and any mixture of the above materials may be used.

Specifically, paraffin wax, polyethylene wax, montan wax, magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, stearic amide, oleic amide, lauric amide, ethylene bisstearamide, Ethylenebislauroamide, stearooleamide, stearyl alcohol, palmityl alcohol, oleyl alcohol, lauryl alcohol, butyl stearate, hydrogenated castor oil, ethylene glycol monostearate, glycerin distearate, ethylene oxide-propylene oxide copolymer, bis (2-ethylhexyl) phthalate, xylylenediamine aliphatic carboxylic acid amide (particularly “Nylon MXD6” (trade name)), polydimethyl Rokisan like and it is preferable to use any mixture thereof.

Next, the polypropylene film and sheet of the present invention will be described. The film and sheet of the present invention can be obtained by calendering the above-mentioned polypropylene-based composition of the present invention as a raw material. In this specification, a calendered product having a thickness of 30 to 100 μm is referred to as a film, and a product having a thickness of 0.1 to 5 mm is referred to as a sheet. This sheet and film
Due to the characteristics of the specific propylene-based block copolymer component, which is an essential component, it has excellent transparency and whitening resistance, good flexural modulus, and physical properties equivalent to polyvinyl chloride.

From the above characteristics, the films and sheets of the present invention are useful as substitutes for polyvinyl chloride films and sheets, and are not particularly limited.
Specific applications of the film and sheet include building paper, furniture and home appliances, decorative paper and wallpaper,
Examples include various coating materials, various leathers such as an automobile interior skin, and stationery such as a case.

Next, a method for producing the present composition will be described. First, the propylene-based block copolymer component, which is a component of the present composition, may be produced by any method as long as the intrinsic viscosity, the viscosity ratio and the product of the viscosity ratio and the weight ratio can be realized. Polymerization of crystalline polypropylene in the gas phase in the presence of a stereoregular catalyst containing a titanium-containing solid catalyst component (A) of a diameter and an organoaluminum compound (B) and, if necessary, an organosilicate compound (C) (First polymerization step), and then copolymerization of the propylene-α-olefin copolymer (second polymerization step),
It is preferably manufactured.

Here, the titanium-containing solid catalyst (A) in the stereoregular catalyst can be used without a carrier, but is used by being supported on an inorganic carrier such as a magnesium compound, a silica compound and alumina or an organic carrier such as polystyrene. Well,
Furthermore, it is also possible to use those obtained by reacting and adding an electron donating compound such as ethers or esters.

As a specific example, an alcohol solution of a magnesium compound is sprayed to obtain a solid component composed of an alcohol adduct of a magnesium compound, the solid component is partially dried, and then the dried solid component is converted to a titanium halide and an electron donor. Dissolving a titanium-containing fixed catalyst (JP-A-3-119003) and a magnesium compound in a solution of tetrahydrofuran / alcohol / electron donor and precipitating with TiCl ₄ alone or in combination with an electron donor And a titanium-containing solid catalyst obtained by treating the magnesium support thus treated with a titanium halide and an electron donating compound (JP-A-4-103604).

The titanium-containing solid catalyst (A) has an average particle size of 25 to 300 μm, preferably 30 to 1 μm.
It is preferable to use one having a thickness of 50 μm. Average particle size is 25μm
If it is less than 1, the fluidity of the obtained block copolymer powder is significantly impaired, and adheres to the walls of the polymerization vessel, stirring blades, etc. to contaminate the polymerization system, and it is difficult to transport the powder discharged from the polymerization vessel. And thus hinder stable operation, which is not preferable.

Further, the titanium-containing solid catalyst (A) preferably has a uniformity of 2.0 or less in a normal distribution, and if the uniformity exceeds 2.0, the powder flowability of the obtained block copolymer will be high. , And continuous stable operation may be difficult, which is not preferable.

As the organic aluminum compound (B),
The following general formula: R ¹ _m AlX _3-m (wherein R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, and m is a positive number satisfying 3 ≧ m ≧ 1). It is preferred to use the compounds represented.

Specific examples of the organoaluminum compound (B) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum and tri-aluminum.
n-butylaluminum, tri-i-butylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum sesquichloride, di-n-propylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum iodide and ethoxydiethyl Aluminum and the like,
Triethyl aluminum can be preferably used. These organoaluminum compounds can be used alone or in combination of two or more.

[0035] As the organic silicon compound (C), the general formula ^{_{R 2 X R 3 Y Si (}} OR 4) Z (R 2 and R ₄ in the formula is a hydrocarbon group, R ³ is a hydrocarbon group or a hetero X represents a hydrocarbon group containing an atom, and X, Y and Z represent 0 ≦ X ≦ 2, 1 ≦ Y ≦ 3, 1 ≦ Z ≦ 3 and X + Y + Z =
4 is satisfied. ) Is preferred.

Specific examples of the organosilicon compound (C) include methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, phenylmethyldimethoxysilane, t-butyltrimethoxysilane, and t-butyltriethoxysilane. Silane, phenyltriethoxysilane, methylethyldimethoxysilane, methylphenyldiethoxysilane, dimethyldimethoxysilane,
Dimethyldiethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, di-t-butyldimethoxysilane, diphenyldimethoxysilane, trimethylmethoxysilane, cyclohexylmethyldimethoxysilane or trimethylethoxysilane and any mixture thereof can be mentioned. Dimethoxysilane, diisopropyldimethoxysilane, di-t
-Butyldimethoxysilane, cyclohexylmethyldimethoxysilane and diphenyldimethoxysilane can be preferably used.

In the production of the block copolymer component,
The stereoregular catalyst containing the titanium-containing solid catalyst component (A), the organoaluminum compound (B) and, if necessary, the organosilicate compound (C) is mixed with the crystalline polypropylene in the first polymerization step. In this case, it is preferable to use the titanium-containing solid catalyst (A) in a state of being preactivated by reacting an α-olefin in advance.

The preliminary activation treatment of the titanium-containing solid catalyst (A) is performed using an organoaluminum compound (B ′).
As the compound (B ′), the above-mentioned organoaluminum compound (B) can be used. In this case, the compound (B ′) may be the same or different from the organoaluminum compound (B) used in the subsequent main polymerization, but the same compound may be used and the compound (B) may be used. ') And (B) are preferably triethylaluminum.

In the preactivation treatment, the amount of the organoaluminum compound (B ') used is not particularly limited, but is usually 0.1 to 1 mol of titanium atom in the titanium-containing solid catalyst (A). It is preferable to use 1 to 40 moles, preferably 0.3 to 20 moles. Under such a usage amount, 0.1 to 100 moles per 1 g of the catalyst (A) is used.
g, preferably 0.5 to 50 g of α-olefin in 10
The reaction is performed at -80 ° C for 10 minutes to 48 hours to complete the pre-activation treatment.

In the above-mentioned preliminary activation processing,
If necessary, the organosilicon compound (C ′) can be used, and as the compound (C ′), the above-mentioned organosilicon compound (C) can be used. In this case, the compound (C ′) may be the same or different from the organosilicon compound (C) used in the subsequent main polymerization, and may be 0.01 to 1 mol of the organoaluminum compound in advance. It is used in a proportion of 10 to 10 mol, preferably 0.05 to 5 mol. As the organosilicon compound (C ′), diisobutyldimethoxysilane, diisopropyldimethoxysilane, di-t-butyldimethoxysilane, cyclohexylmethyldimethoxysilane, and diphenyldimethoxysilane can be suitably used.

The olefins used in the preactivation treatment include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-decene.
Dodecene, 1-tetradecene, 1-hexadecene, 1-
Examples include octadecene, 1-eicosene, 4-methyl-1-pentene or 3-methyl-1-pentene and any mixtures thereof. It is also possible to use a molecular weight regulator such as hydrogen for controlling the molecular weight of the polymer during the polymerization.

In the preactivation treatment, an inert solvent is used. As the inert solvent, a solvent which does not significantly affect the polymerization reaction, for example, hexane, heptane, octane, decane, dodecane, liquid paraffin And the like, and a silicone oil having a structure of liquid saturated hydrocarbon or dimethylpolysiloxane. These solvents can be used alone or in combination of two or more. When such an inert solvent is used, it is desirable to remove impurities such as water and sulfur compounds that adversely affect the polymerization.

As described above, in the production of the block copolymer component in the polypropylene composition of the present invention, a first polymerization step of polymerizing crystalline polypropylene in a gas phase in the presence of the above-mentioned stereoregular catalyst is included. And a second polymerization step of copolymerizing a propylene-α-olefin copolymer. Here, the first polymerization step is not limited to gas phase polymerization, and slurry polymerization or bulk polymerization may be performed. However, the second polymerization step performed subsequently to this step may be gas phase polymerization. From the viewpoint of being preferable, it is preferable that the first polymerization step is also a gas phase polymerization. In addition, if slurry polymerization or bulk polymerization is adopted as the second polymerization step, the copolymer is eluted in the solution, and it may be difficult to continue stable operation, which is not preferable.

The polymerization conditions of the crystalline polypropylene in the first polymerization step vary depending on the polymerization mode to be employed. In the case of the gas phase polymerization method, a certain amount of polypropylene powder is used as a dispersant while mixing and stirring in a polymerization vessel. In the presence of a pre-activated stereoregular catalyst containing a titanium-containing catalyst and the like, the polymerization temperature is set to 20 to 120 ° C, preferably 40
To 100 ° C., the polymerization pressure is controlled to atmospheric pressure to 9.9 MPa, preferably 0.59 to 5.0 MPa, and propylene and α-olefins other than propylene are supplied as necessary,
The crystalline polypropylene is polymerized.

At this time, the ratio of the organoaluminum compound (B) and the titanium-containing solid catalyst (A) used was such that Al / Ti =
The molar ratio is preferably 1 to 500, and more preferably 10 to 30. In this case, the number of moles of the titanium-containing solid catalyst component (A) substantially indicates the number of grams of Ti in the titanium-containing solid catalyst component (A).

The ratio of the organosilicon compound (C) to the organoaluminum (B) is usually B / C = 1 to 10 (molar ratio), preferably 1.5 to 8. If the B / C molar ratio exceeds 10, the crystallinity of the crystalline polypropylene may be reduced, and the rigidity of the obtained block copolymer component may be insufficient. On the other hand, when the B / C molar ratio is less than 1, the polymerization activity is remarkably reduced, and the productivity may be reduced.

For controlling the molecular weight of the crystalline polypropylene component, a molecular weight regulator such as hydrogen can be used at the time of polymerization. In this case, the intrinsic viscosity of the crystalline polypropylene component satisfies the above-mentioned predetermined range of the present invention. It should be done as follows. After polymerizing the crystalline polypropylene, a part of the produced powder was extracted, and the intrinsic viscosity, MFR, the amount of the xylene-soluble component at 20 ° C. and the isotactic fraction (P) were measured, and the polymerization yield per unit weight of the catalyst was measured. It is preferable to perform measurement and check the properties of the crystalline polypropylene.

Next, following the above-mentioned first polymerization step, a second polymerization step for producing a propylene-α-olefin copolymer is carried out. The polymerization temperature in this second polymerization step is preferably 20 to 120 ° C. Is 40 to 100 ° C., and the polymerization pressure is atmospheric pressure to 9.9 MPa, preferably 0.59 to
The pressure is controlled to 5.0 MPa, and under such conditions, an α-olefin, for example, a mixed monomer of ethylene and propylene is copolymerized. The ethylene unit content in the obtained copolymer is controlled by controlling the gas molar ratio between the ethylene monomer and the propylene monomer in the comonomer gas.
Although it can be adjusted, it is preferable to be 22 to 55% by weight.

The weight of the copolymer with respect to the weight of the crystalline polypropylene can be controlled by adjusting the polymerization time or by using a polymerization activity regulator for a catalyst such as carbon monoxide or hydrogen sulfide. However, in the present invention,
Preferably, the weight of the copolymer is adjusted to 22 to 60% by weight. Further, the intrinsic viscosity of the copolymer is:
The addition of a molecular weight modifier such as hydrogen during the polymerization of the copolymer may be adjusted within the predetermined range of the present invention. The supply of hydrogen depends on the Q of the obtained block copolymer component.
This is performed so that the value (Mw / Mn) falls within the predetermined range of the present invention.

The polymerization system may be any of a batch system, a semi-continuous system and a continuous system, but it is preferable to employ a continuous polymerization system from an industrial viewpoint.

After the completion of the second polymerization step, if the monomer is removed from the polymerization system, a particulate polymer which is a propylene-based block copolymer component is obtained. Such a particulate polymer has an intrinsic viscosity, a 20 ° C. xylene-soluble component amount, Q
It is used for measuring the value and the ethylene content, and for measuring the polymerization yield per unit weight of the catalyst, and can be used for quality control of the polypropylene composition of the present invention.

The propylene-based composition of the present invention is prepared by adding the propylene-based block copolymer component obtained as described above and, if necessary, various additives such as a heat stabilizer, a neutralizing agent, and a light stabilizer. And the mixture is stirred and mixed, and the obtained mixture is further melt-kneaded to obtain a mixture. At this time, typically, stirring and mixing can be performed by various stirring mixers such as a Henschel mixer, and melt-kneading can be performed by various extruders, and the present polypropylene-based composition is usually obtained in the form of pellets.

The polypropylene composition thus obtained is particularly suitable for use in calendering and is used as a raw material for calendered articles having various shapes. At the time of such calendering, various additives such as the above-mentioned lubricant, antioxidant, neutralizing agent, antistatic agent and weathering agent, which are conventionally known in calendering, are added to the present polypropylene-based composition as required. It is possible to add.

In producing the polypropylene film and sheet of the present invention, the polypropylene composition of the present invention has physical properties comparable to polyvinyl chloride. The calender molding machine used for polyvinyl chloride can be used as it is, and film formation may be performed using such a calender molding machine.

As described above, the calendering machine may be any calendering machine usually used for polyvinyl chloride as described above.
A roll provided with a mixing roll, a warming roll, an extruder, a calender roll, a cooling roll, a trimming cutter, masking, a fixed-size cutter, and a winding machine (calender forming machine) is preferable. The calendering machine has a series type, an inclined type, and an L type depending on the type of roll arrangement.
Although there are forms such as a shape, an inverted L shape, a Z shape, and an inclined Z shape, any type of calendering machine can be suitably used in the present invention. As described above, according to the present invention, the existing equipment for polyvinyl chloride can be used as it is, and it is possible to realize low-cost and resource-saving calendar processing without requiring special equipment.

In the above calender molding, the resin temperature, that is, the temperature of the present polypropylene-based composition is 160
It is preferable that the temperature be set to 250 ° C., whereby a film or a sheet having excellent appearance and moldability can be reliably obtained. When the resin temperature is 160 ° C. or higher, the present polypropylene-based composition is sufficiently melted, and the surface of the obtained sheet or the like does not become shark skin-like, and a good appearance is obtained. Meanwhile, 2
When the temperature is 50 ° C. or lower, thermal deterioration of the present polypropylene composition hardly occurs, the melt tension of a sheet or the like can be maintained, and good moldability can be easily achieved.

Further, the temperature of the cooling roll is preferably 5 to 130 ° C. in order to surely obtain an excellent appearance.
By setting the temperature of the cooling roll to 5 ° C. or higher, dew condensation on this roll can be prevented, and a good appearance can be obtained by avoiding the formation of a spot-like pattern on the surface of a sheet or the like. Also, 1
When the temperature is 30 ° C. or lower, the sheet or the like can be sufficiently cooled, and a good appearance can be obtained. In addition, it is preferable to provide several cooling rolls provided after the calender roll, whereby the resin can be gradually cooled in a stepwise manner, so that the adhesion of the resin can be effectively prevented.

The calendering speed is preferably 0.1 to 150 m / min in order to realize excellent productivity. When the molding speed is 0.1 m / min or less, the production amount per hour of a sheet or the like can be increased, a sheet or the like having a uniform thickness can be easily obtained, and the defective rate can be reduced. Meanwhile, 1
When the speed is 50 m / min or less, the sheet and the like can be sufficiently cooled, so that a good appearance is easily obtained.

[0059]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, the following performance evaluation was performed at the time of calendering and the obtained sheet in each example, and the obtained results are shown in Table 1.

(Intrinsic viscosity [η]: dl / g) Using tetralin (tetrahydronaphthalene) as a solvent, 135
It measured using the automatic viscosity measuring device (AVS2 type, the product made by Mitsui Toatsu Chemicals, Inc.) under the temperature condition of ° C.

(Ethylene unit content C2, RC-Se
g: wt%) It was measured by an infrared absorption spectrum method.

(Haze) Using a 150 μm thick sheet prepared by two rolls as described below,
03.

(Bleaching Resistance) As described later, a sheet having a thickness of 150 μm prepared with two rolls was
(4) Bending was performed, and the whitening state was visually observed. Table 1
The evaluation is based on the following criteria. In this specification,
◎, △, and Δ were judged to be good. A: No whitening. …: Light whitening is observed. Δ: Whitening is observed, but whitening disappears when folded. ×: Strong whitening, whitening does not disappear even when folded.

(Flexural modulus MPa) The polypropylene composition of each example was injection molded at a set temperature of 230 ° C.
It was measured according to K7203.

(Calendar workability [working temperature range Δt])
As a sample device, two rolls [roll size 200 mm
φ × 500 mm, rotational speed: front roll 12 rpm / rear roll 14 rpm, kneading for 10 minutes (manufactured by Nishimura Koki Co., Ltd.)]. Finished sheet thickness 150μm with roll gap
The pellets of the polypropylene-based composition obtained in each of the following examples were melt-kneaded while being wound around the above-mentioned roll, and after 10 minutes, the sheet kneaded was sampled. At the time of sampling, the temperature at which the molten resin adhered to the roll and became unremovable was regarded as the temperature at which adhesion occurred, and was determined as the upper limit temperature for calendering. In addition, the pellets of each example were melt-kneaded while being wound around a roll, and after 10 minutes, the molten sheet on the roll was observed. It was determined to be the defective temperature and the lower limit temperature for calendering.
Further, the temperature width between the above-mentioned surface transfer temperature and the temperature at which the sticking occurred was defined as a processing temperature width Δt at which calendering was possible.

The propylene-based block copolymer components used in the following Examples and Comparative Examples were obtained by the following production methods, employing the formulations shown in Table 1.

1) Preparation of titanium-containing solid catalyst component a) Titanium-containing solid catalyst component (I) An anhydrous MgCl 2 was placed in a SUS autoclave purged with nitrogen.
₂ 95.3 g, ingress of dry EtOH352ml, the mixture was dissolved by heating to 105 ° C. under stirring. After stirring for 1 hour, the solution was heated to 105 ° C. under pressurized nitrogen (1.
1 MPa) and inserted into the fluid spray nozzle. On this occasion,
The flow rate of the nitrogen gas was 38 l / min, liquid nitrogen for cooling was introduced into the spray tower, and the temperature in the tower was maintained at -15 ° C. The product was collected in cold hexane introduced into the bottom of the column to obtain 256 g of the product. Analysis of this product showed that it had the same composition as the starting solution, MgCl ₂ .6EtOH.
Met.

The product obtained is sieved and 45 to 21
205 g of a spherical carrier having a particle size of 2 μm were obtained. The resulting carrier was cooled to room temperature under nitrogen at a flow rate of 3 l / min at room temperature for 1 hour.
Air dried for 81 hours, and the composition was MgCl ₂ 1.7 EtO
A dry carrier, H, was obtained. 20 g of this dry carrier, 160 ml of titanium tetrachloride and purified 1,2-dichloroethane 24
0 ml into a glass flask, mix and mix under stirring.
After heating to 100 ° C., 6.8 ml of diisobutyl phthalate was added, the mixture was further heated at 100 ° C. for 2 hours, the liquid phase was removed by decantation, and titanium tetrachloride 160
and purified 320 ml of 1,2-dichloroethane. Next, after heating and holding at 100 ° C. for 1 hour, the resultant was washed with purified hexane and dried, and then the titanium-containing solid catalyst component I-
1 was obtained. The average particle size of the obtained titanium-containing solid catalyst component (I) was 115 μm, and the analysis value was Mg;
9.5% by weight, Ti: 1.6% by weight, Cl: 59.0% by weight, diisobutyl phthalate: 4.5% by weight.

2) Pre-Activation Treatment of Titanium-Containing Solid Catalyst Component (I) After replacing a SUS reactor with an internal volume of 15 l with inclined blades with nitrogen gas, saturation at 40 ° C. with a kinematic viscosity of 7.3 cSt was performed. 8.3 l of hydrocarbon solvent (CRYSTOL-52, manufactured by Esso Oil Co., Ltd.), 525 m of triethylaluminum
mol, diisopropyldimethoxysilane 80mmo
l, 700 g of the titanium-containing solid catalyst component obtained as described above was added at room temperature, heated to 40 ° C., and then reacted at a propylene partial pressure of 0.15 MPa for 7 hours to perform a preactivation treatment. As a result of the analysis, 3.0 g of propylene was reacted per 1 g of the titanium-containing solid catalyst component.

3) First polymerization step In FIG. 1, a horizontal polymerization vessel 1 having a stirring blade (L / D
= 6, inner volume 100 l), 0.5 g / hr of the pre-activated titanium-containing solid catalyst component, triethylaluminum as organoaluminum compound (II),
And diisopropyldimethoxysilane as the organosilicon compound (III) was continuously supplied. Then, the reaction temperature is 70 ° C., the reaction pressure is 2.5 MPa, and the stirring speed is 40 rpm.
m is maintained, and hydrogen gas is continuously supplied from the circulation pipe 2 to adjust the molecular weight of the crystalline polypropylene component. The intrinsic viscosity of the polymer was controlled.

The heat of reaction was removed by the heat of vaporization of the raw material liquid propylene supplied from the pipe 3. The unreacted gas discharged from the polymerization reactor was cooled and condensed outside the reactor system through the pipe 4 and returned to the polymerization reactor 1. The crystalline polypropylene component obtained in the present polymerization vessel was continuously withdrawn from the polymerization vessel 1 through the pipe 5 so that the polymer holding level was 50% by volume of the reaction vessel.
0. At this time, a part of the crystalline polypropylene component was intermittently extracted from the pipe 5 to obtain a sample for which the intrinsic viscosity and the polymer yield per unit weight of the catalyst were determined. The polymer yield per unit weight of the catalyst was calculated from the Mg content in the polymer measured by high frequency inductively coupled plasma emission spectroscopy (ICP method).

4) Second Polymerization Step The crystalline polypropylene component and ethylene gas from the first polymerization step are introduced into the horizontal polymerization vessel 10 (L / D = 6, internal volume 100 l) having stirring blades. Than,
In addition, liquid propylene is continuously supplied from the raw material propylene pipe 6, and the stirring temperature is 40 rpm, the temperature is 60 ° C.,
The ethylene unit content in the copolymer component was adjusted under the conditions of a pressure of 2.1 MPa and a molar ratio of ethylene / propylene in the gas phase. Carbon monoxide as a polymerization activity inhibitor was supplied from a pipe 7 to adjust the polymerization amount of the copolymer component, and hydrogen was similarly supplied from the pipe 7 to adjust the molecular weight of the copolymer component.

The reaction heat was removed by the heat of vaporization of the raw material liquid propylene supplied from the pipe 6. The unreacted gas discharged from the polymerization vessel was cooled and condensed outside the reactor system through the pipe 8, and was returned to the present copolymerization step. The propylene-based block copolymer produced in the copolymerization step was withdrawn from the polymerization vessel 10 via the pipe 9 so that the level of the retained polymer was 50% by volume of the reaction volume. The production rate of the propylene-based block copolymer composition was 8 to 12 kg / hr.
The extracted propylene-based block copolymer composition was subjected to measurement of the intrinsic viscosity, the yield of the polymer per unit weight of the catalyst, and the infrared measurement of ethylene in the copolymer component after removing the monomer.

According to the above procedure, the powdery prop
A len-based block copolymer component was obtained. Note that this block
Ethylene-propylene copolymer in copolymer component
-Intrinsic viscosity [η]_RC, Copolymer and propylene homopo
Intrinsic viscosity ratio with limer [η] _RC/ [Η]_PP, And these
Weight ratio W_PP/ W_RC([Η]_RC/ [Η]_PP) × (W
_PP/ W_RC) Are the values shown in Table 1.

(Examples 1 to 6, Comparative Examples 1 to 5) 100 parts by weight of the propylene-based block copolymer component powder obtained as described above were added to 2,6, a phenol-based heat stabilizer. -Di-t-butyl-p-cresol 0.1
Parts by weight, and a neutralizing agent calcium stearate 0.1
The parts by weight were put into a high-speed stirrer (Henschel mixer: trade name) and stirred for 2 minutes to obtain a mixture. After a while
This mixture was melt-kneaded at 200 ° C. with an extruder having a diameter of 40 mm and extruded to obtain pellets of the polypropylene composition used in each example. Each of the above-described evaluations was performed using the obtained pellets, and the obtained results are shown in Table 1.

In Table 1, “PP” is crystalline polypropylene, “RC” is propylene-ethylene copolymer,
“T-MFR”, “PP-MFR” and “RC-MF”
R "represents the entire polypropylene composition of each example, P
Means the MFR of P and RC. Also, “T-C2”,
“PP-C2” and “RC-C2” respectively mean the entire polypropylene composition of each example, the ethylene component content in PP and RC, and “RC-Seg” means the total propylene composition of each example. Means RC content.

[0077]

[Table 1]

From Table 1, it is found that a propylene block copolymer component containing a copolymer of crystalline polypropylene and a propylene-α-olefin is contained, the intrinsic viscosity [η] _{RC of} the copolymer in this block copolymer component, the copolymer and the crystal. Intrinsic viscosity ratio with conductive polypropylene [η] _RC /
[Η] _PP , the product of this intrinsic viscosity ratio and these weight ratios ([η] _RC / [η] _PP ) × (W _PP / W _RC ) and the MFR of the block copolymer component of the present invention The polypropylene-based compositions of Examples 1 to 6 in the predetermined range have good calenderability, and have transparency equivalent to that of soft / semi-hard polyvinyl chloride, that is, low haze value and whitening resistance. It can be seen that they have the properties and flexibility.

From Comparative Examples 1, 2 and 3, [η] _RC , [η] _RC / [η] _PP , ([η] _RC /
Even if [η] _PP ) × (W _PP / W _RC ) falls within the predetermined range of the present invention, the block copolymer component has an MFR of 0.1 g / m 2.
When it is out of the range of in to 3.5 g / min, the processing temperature width Δt becomes 20 ° C. or less, which indicates that it is not suitable for calendering. As in Comparative Example 4, even if the MFR of the block copolymer component is within the predetermined range of the present invention, [η] _RC , [η] _RC / [η] _PP , ([η]
_{When RC} / [η] _PP ) × (W _PP / W _RC ) is out of the predetermined range of the present invention, the processing temperature width Δt is relatively wide, but the calendering processability is not sufficient, and the process is difficult. It can be seen that the whitening property is also poor. Further, in Comparative Example 5, the polypropylene-based composition was crystalline polypropylene and propylene-
This is an example that does not contain a propylene block copolymer component containing a copolymer of α-olefin, in this case,
It is clear that the processing temperature width Δt is narrow.

[0080]

As described above, according to the present invention, since a propylene block copolymer having a specific composition is used, the calendering processability is excellent at a low cost, and the soft / semi-hard polyvinyl chloride is used. And a polypropylene-based composition, a polypropylene-based film and a sheet comparable to the above. That is, since the polypropylene-based composition of the present invention has the same physical properties as polyvinyl chloride and can be substituted as it is, according to the present invention, existing polyvinyl chloride equipment can be used as it is. This makes it possible to realize low-cost and resource-saving calendar processing without requiring special equipment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a polymerization system of a polypropylene composition.

[Explanation of symbols]

 1,10 Polymerizer 2 Circulation piping 3,6 Raw propylene piping 4,8 Unreacted gas piping 5,9 Polymer extraction piping

Claims (7)

[Claims] 1. Crystalline polypropylene and propylene-α
A polypropylene composition for calendering, comprising a propylene block copolymer component containing an olefin copolymer, wherein the intrinsic viscosity [η] _RC of the copolymer in the block copolymer component is 6.5 dl / g. Hereinafter, the intrinsic viscosity ratio [η] _RC / of the copolymer and the crystalline polypropylene will be described.
[Η] _PP is 0.5-3.0, and this intrinsic viscosity ratio [η] _RC
/ [Η] _PP and the product of these weight ratios W _PP / W _RC ([η]
_RC / [η] _PP ) × (W _PP / W _RC ) is 0.2 to 7.0, and the melt flow rate is 0.1 g / 10 min to 3.5 g.
/ 10 min (230 ° C., 21.18 N), a polypropylene-based composition for calendering. 2. A processing temperature range Δ during calendering.
2. The polypropylene composition according to claim 1, wherein t is 30 ° C. or higher. 3. The crystalline polypropylene in the block copolymer component is a propylene homopolymer or a propylene-α-olefin random copolymer having a propylene content of 90 to 99% by weight based on the weight of the crystalline polypropylene. The polypropylene-based composition according to claim 1, wherein: 4. The propylene block copolymer according to claim 1, wherein the propylene-α-olefin copolymer contains 20 to 55% by weight of ethylene polymerized units based on the weight of the copolymer. Or 1
A polypropylene-based composition according to any one of the first to third aspects. 5. The propylene-α-olefin copolymer in the propylene-based block copolymer has a propylene-based block copolymer component content of 15% by weight.
The polypropylene-based composition according to any one of claims 1 to 4, characterized in that it contains コ ポ リ マ ー 50% by weight of the copolymer. 6. A polypropylene film obtained by calendering the polypropylene composition according to any one of claims 1 to 5. 7. A polypropylene sheet obtained by calendering the polypropylene composition according to any one of claims 1 to 5.