JP2002348334A - Polypropylene resin composition, method for producing the same, and foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin composition which can be melted to have high viscosity and melt tension and is suitable for producing a foam sheet being excellent in secondary processing. SOLUTION: The composition comprises being produced by a multi-step polymerization process, the first step of which produces a propylene polymer followed by the second step producing an ethylene polymer, wherein the propylene polymer is contained by 85-99 wt.% in the composition and has a limiting viscosity [η] of 3.0-12 (dl/g); and the ethylene polymer is contained by 1-15 wt.% in the composition and has a limiting viscosity of 5.0-100 (dl/g). The composition can be melted and kneaded to give an improved composition being better in secondary processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polypropylene resin composition having improved melting properties, a method for producing the same, and a foam formed from the composition.

[0002]

BACKGROUND OF THE INVENTION In general, a foam made of a thermoplastic resin is lightweight and has heat insulating properties, and has good buffering properties against external stress. Widely used as such. Above all, in the field of trays for fresh foods and processed foods or containers for cup ramen, polystyrene foams have conventionally been used, but from the viewpoint of environmental protection and the like, there has been a demand for foams using other resins. Is growing. Polyolefin resin foams, especially polypropylene foams, have good chemical resistance, impact resistance and heat resistance, are excellent in food hygiene, and are easy to incinerate waste. For reasons
Prospects for use as trays for fresh foods and processed foods are promising and studies have begun.

However, since the polypropylene resin is crystalline, the viscosity and the melt tension at the time of melting are low, and the viscosity is not easily increased sharply at the time of elongation deformation. Therefore, even if foaming is performed, since the expansion ratio is low and the cells are easily broken,
It has been difficult to produce a low-density foam having high closed-cell properties, excellent appearance, and excellent secondary workability. further,
It has also been pointed out that when a foamed sheet is heated and softened and subjected to secondary processing such as vacuum forming, the sheet tends to draw down (hang down).

Therefore, for example, Japanese Patent Application Laid-Open No. Sho 61-152754
As disclosed in Japanese Patent Application Laid-Open Publication No. H11-107, an attempt has been made to increase the melt tension of a resin by adding a crosslinking aid to a polypropylene resin together with a foaming agent to crosslink polypropylene molecules. However, this method is still insufficient to increase the melt tension and increase the viscosity at the time of elongation deformation, and odor is generated from the remaining crosslinking aid. Did not.

A method of blending a polypropylene resin with polyethylene to form a foam is disclosed in JP-B-44-25.
No. 74, for example. However, even by this method, the effect of increasing the melt tension of the polypropylene resin is not sufficient, and it is difficult to produce a foam having excellent secondary workability.

[0006] Further, Japanese Patent Application Laid-Open No. 10-292069 discloses that at the stage of prepolymerization at the time of catalyst preparation, ultrahigh molecular weight polyethylene is first produced in an amount of 5% by weight or less, and then the main polymerization of propylene is carried out. A method is described in which a radical initiator is added to the obtained polypropylene resin and melt-kneaded. Even if the melt tension of the polypropylene resin is improved by this method, it is still difficult to obtain a resin having characteristics suitable for foam molding.

In this method, since the high-molecular-weight polyethylene is produced at the stage of pre-polymerization at the time of preparing the polymerization catalyst, there is a natural upper limit on the amount of the produced polyethylene. Can not. Furthermore, since the preliminary polymerization is usually performed in a catalyst preparation step which is a separate step from the main polymerization of propylene, the whole polypropylene production step may be complicated.

[0008]

Therefore, the first aspect of the present invention
An object of the present invention is to provide a polypropylene resin composition having a high viscosity at the time of melting and a high melt tension. A second object of the present invention is to provide a polypropylene resin composition having excellent foam moldability and suitable for producing a foam having high rigidity and a closed cell ratio. Third of the present invention
An object of the present invention is to provide a polypropylene resin composition which is excellent in secondary moldability and suitable for producing a foam having good food hygiene. A fourth object of the present invention is to provide a method for producing such a polypropylene resin composition. It is a further object of the present invention to provide a foam formed from such a polypropylene resin composition and having excellent secondary moldability.

[0009]

That is, the present invention relates to a composition obtained by producing a propylene polymer in a first step and subsequently producing an ethylene polymer in a second step,
The intrinsic viscosity [η] of the propylene polymer contained in the composition at 85 to 99% by weight is 3.0 to 12 (dl / g), and the ethylene polymer contained at 1 to 15% by weight in the composition is The present invention relates to a polypropylene resin composition having an intrinsic viscosity [η] of 15 to 100 (dl / g).

In the second invention, the intrinsic viscosity [η] in the first stage is
To produce a propylene polymer having a limiting viscosity [η] in the presence of the propylene polymer containing a catalyst whose polymerization activity is retained in the subsequent second step. Produces an ethylene polymer of 15 to 100 (dl / g), the propylene polymer occupying 85 to 99% by weight in the obtained composition and the ethylene polymer being 1 to 1
The present invention relates to a method for producing a polypropylene resin composition of 5% by weight. In the second step, the polymerization of ethylene is carried out in the presence of propylene, and the propylene unit content in the ethylene polymer produced there may be 0.1 to 15% by weight.

In this production method, the first step employs a method in which propylene is polymerized under a condition using propylene as a solvent, and the second step adopts a method in which ethylene is polymerized under a gas phase condition. Is also good.

According to a third aspect of the present invention, after a resin composition is produced by the above-described method, the composition further has a specific energy of 0.2.
The present invention relates to a method for producing a polypropylene resin composition in which a melt-kneading operation is performed under a condition of 5 (kw / kg) or more.
This melt-kneading operation is preferably performed in the co-presence of an organic peroxide.
2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexyne-3 is preferred.

Further, the present invention relates to a foam which is formed into a sheet from the above-mentioned polypropylene resin composition or the polypropylene resin composition produced by the above-mentioned method, and which contains closed cells in the sheet. This foam has excellent subsequent moldability.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Next, the polypropylene resin composition according to the present invention, a method for producing the same, and a foam produced from the resin composition will be specifically described.

Polypropylene Resin Composition (1) The polypropylene resin composition of the present invention is prepared by first using a multistage polymerization apparatus combining at least two or more polymerization vessels and using the same polymerization catalyst in the first stage. In the second step, an ethylene polymer is produced, and the composition of at least two or more polymers thus obtained is obtained.

The feature of this composition is that the amount of the propylene polymer produced in the first stage and the amount of the ethylene polymer produced in the second stage are determined by the required amount of each component constituting the composition. It can be freely controlled to quantity. In the present invention, the mixing ratio of each component in the composition is such that the propylene polymer is 85 to 99% by weight, preferably 90 to 9% by weight.
It is desirable that the content of ethylene polymer is in the range of 1 to 15% by weight, preferably 3 to 10% by weight. When in such a range, the composition has a high viscosity at the time of melting and exhibits a high melt tension.

The propylene polymer as the main component of the composition may be a homopolymer of propylene, or propylene and other carbon atoms having 2 to 20, preferably 2 carbon atoms.
It may be a copolymer with 10 to 10 α-olefins.
Here, examples of the α-olefin include ethylene, 1-
Butene, 1-pentene, 1-hexene, 4-methyl-1
Examples thereof include -pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene, with ethylene being preferred. These α-olefins may form a random copolymer with propylene, or may form a block copolymer.

The propylene polymer is preferably a propylene homopolymer, but in the case of a copolymer of propylene and an α-olefin, the structural unit derived from the α-olefin is 5 mol / mol in the propylene polymer. %, Preferably not more than 2 mol%.

Such a propylene polymer has an intrinsic viscosity [η] of 3.0 to 12 (dl / g), preferably 3.4 to 12 (dl / g), and more preferably 5 to 11 (dl / g).
(Dl / g). When the value of the intrinsic viscosity [η] is in the above range, the viscosity when the composition is melted is high, and the composition has a high melt tension. Here, the intrinsic viscosity [η] is
It is a value measured at 135 ° C. in a tetralin solvent.

The ethylene polymer as a subcomponent of the resin composition may be a homopolymer of ethylene, or ethylene and α having 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms.
-It may be a copolymer with an olefin. Where α
-Examples of olefins include propylene, 1-butene,
1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1
-Eicosene, etc., of which propylene is preferred. These α-olefins may form a random copolymer with ethylene,
A block copolymer may be formed. When a copolymer, a structural unit derived from an α-olefin,
It is desirable that the content is 10 mol% or less, preferably 5 mol% or less in the ethylene polymer. In particular,
When the α-olefin is propylene, the propylene unit content is 0.1 to 15% by weight, preferably 0.1 to 2%.
% By weight is desirable.

Further, the ethylene polymer may contain a small amount of a C4-20 diene component as a comonomer. Examples are 1,3-butadiene, 1,3-
Pentadiene, 1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-
1,4-hexadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl- 1,6-octadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 6-methyl- 1,6-decadiene, 7-methyl-1,6-decadiene, 6-methyl-
1,6-undecadiene, 1,7-octadiene, 1,
Mention may be made of 9-decadiene, isoprene, ethylidene norbornene, vinylnorbornene and dicyclopentadiene. The constituent units derived from these diene components are desirably adjusted to 2 mol% or less, preferably 1% mol or less in the ethylene polymer.

Such an ethylene polymer has an intrinsic viscosity [η] of 15 to 100 (dl / g), preferably 1 to 100 (dl / g).
5 to 60 (dl / g), more preferably 15 to 35 (d
1 / g). Use of an ethylene polymer having an intrinsic viscosity [η] within the above range increases the melt viscosity of the composition and gives a high melt tension. Here, the intrinsic viscosity [η] is a value calculated from the intrinsic viscosity of the resin composition, the intrinsic viscosity of the propylene polymer, and the ratio of the ethylene polymer in the composition.

That is, the intrinsic viscosity of the ethylene polymer is calculated from the following equation. [Η] ₃ = ｛[η] _2- [η] ₁ × (100-α) / 1
00｝ × (100 / α) where [η] ₁ is the intrinsic viscosity of the propylene polymer (d
1 / g) [η] ₂ was obtained by heating the resin composition in a tetralin solvent at 135 ° C.
The intrinsic viscosity (dl / g) [η] of the intrinsic viscosity measured in ( ₃ ) is the intrinsic viscosity (dl / g) of the ethylene polymer, and α is the ratio (% by weight) of the ethylene polymer in the resin composition. .

When the propylene polymer and the ethylene polymer are in the above-mentioned composition range, and each polymer is in the above-mentioned intrinsic viscosity range, the resin composition composed of the propylene polymer and the ethylene polymer becomes Extrusion, hollow molding,
It is suitable for injection molding and the like, and can produce various molded products satisfactorily. In addition, when a melt-kneading operation is added to the resin composition, the uniformity increases, and the moldability can be further improved.

In particular, the polypropylene resin composition comprises:
Since the melt tension and the melt flow rate have high values, and the viscosity rise during elongation deformation is sharp, it shows good foam moldability, contains closed cells, and has a good appearance. Suitable for manufacturing. Also, when melt-mixed with an organic peroxide to be described later, a foamed sheet having less appearance of a gel component and a good appearance can be obtained. Further, even when the foamed sheet is applied to secondary molding such as vacuum molding, the heated foamed sheet hardly causes a drawdown, and can be formed into a good tray or container with good production efficiency.

Polypropylene resin composition (2) The above-mentioned polypropylene resin composition may be mixed with other resinous or rubbery polymers or various additives or compounding agents, if necessary, without impairing the object of the present invention. Can be mixed in a range.

The first preferred compounding agent is a polypropylene produced separately from the polypropylene resin produced by the above-mentioned multi-stage polymerization method, which may be a propylene homopolymer or a mixture of propylene and an α-olefin. May be used. As the α-olefin, the number of carbon atoms other than propylene is 2 to 20, preferably 2 to
Ten olefins are desirable, and the content of structural units derived from α-olefins may be contained in polypropylene at a ratio of 5% or less, preferably 2% or less.

When such a polypropylene is compounded, the polypropylene resin composition is 1 to 99, preferably 50 to 99, more preferably 80 to 95% by weight, and the polypropylene is 1 to 99, preferably 1 to 50, More preferably, the range is 5 to 20% by weight. Thereby, the moldability and appearance of the foam sheet described later are favorably improved.

Examples of the second compoundable resinous or rubbery polymer include the following polymers. The compounding amount is usually 25% by weight or less, preferably 10% by weight or less.
% By weight or less.

(1) Polyethylene, poly 1-butene, polyisobutene, poly 1-pentene, poly 4-methyl-1
-Poly alpha-olefins such as pentene (2) Ethylene propylene copolymer, ethylene 1-
Α-olefin copolymers such as butene copolymer, propylene / 1-butene copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer

(3) Ethylene / vinyl chloride copolymer, ethylene / vinylidene chloride copolymer, ethylene / acrylonitrile copolymer, ethylene / methacrylonitrile copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylamide copolymer Polymer, ethylene / methacrylamide copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / maleic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate Polymer, ethylene-methyl methacrylate copolymer, ethylene-maleic anhydride copolymer, ethylene-metal acrylate copolymer, ethylene-methacrylic acid metal salt copolymer, ethylene-styrene copolymer, ethylene Methylstyrene copolymer, ethylene / divinylbenzene copolymer, etc. Styrene-vinyl monomer copolymer

(4) polyisobutene, polybutadiene,
Diene copolymers such as polyisoprene, styrene / butadiene random copolymer, styrene / butadiene / styrene block copolymer, hydride of styrene / butadiene random copolymer, and hydride of styrene / butadiene / styrene block copolymer (5) Polymer alloys such as acrylonitrile / butadiene / styrene resin and methyl methacrylate / butadiene / styrene resin

(6) Vinyl monomer polymers such as polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl acetate, polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, etc. (7) Copolymer of vinyl chloride and acrylonitrile Copolymer, vinyl monomer copolymer such as vinyl chloride / vinyl acetate copolymer, acrylonitrile / styrene copolymer, methyl methacrylate / styrene copolymer

Further, the polypropylene resin composition may further contain an antioxidant, an ultraviolet absorber, a metal soap, a hydrochloric acid absorber, a nucleating agent, a lubricant, a plasticizer, a filler, a reinforcing agent, a pigment, a dye, Stabilizers and additives such as flame retardants and antistatic agents can be mixed within a range that does not impair the object of the present invention.

As described above, a mixture of polypropylene, a resinous or rubbery polymer, or a compounding agent such as a stabilizer or an additive further added to the above-mentioned polypropylene resin composition can be obtained by a dry blending method or a melt blending method. By adopting the resin composition, a uniformly mixed resin composition can be obtained.

Method for Producing Resin Composition (1) The method for producing a polypropylene resin composition according to the present invention uses a multi-stage polymerization apparatus in which at least two or more polymerization vessels are combined. This is a method in which the polymerization is carried out in the presence of an olefin stereoregular polymerization catalyst, and then the polymerization of ethylene in the second step is carried out in the presence of a propylene polymer containing a catalyst having a polymerization activity. Thus, by incorporating an ethylene polymerization process into a series of propylene polymerization processes, a target resin composition can be efficiently produced.

In the first stage, first, a polymerization catalyst is supplied to the first polymerization reactor, propylene is supplied as a monomer, and other α-olefins are supplied if necessary, so that homopolymerization of propylene or propylene and α-olefin Is carried out. In the second stage, first, the propylene polymer produced in the first stage is transferred to a second polymerization reactor together with a polymerization catalyst. At that time, the operation is performed so that the catalyst does not deactivate the polymerization activity. Ethylene is supplied to the second polymerization vessel, and if necessary, other α-olefins are also supplied to perform homopolymerization of ethylene or copolymerization of ethylene and α-olefin. The amount of the propylene polymer produced in the first stage and the amount of the ethylene polymer produced in the second stage are 85 to 99% by weight, preferably 90 to 97% by weight of the propylene polymer in the composition,
1 to 15% by weight of ethylene polymer, preferably 3 to 10%
Adjust so that it becomes% by weight.

In the present invention, a propylene polymer is produced in the first stage using a multistage polymerization apparatus, an ethylene polymer is produced in the second stage, and the propylene polymer and the ethylene polymer are finally contained. It is important to produce a resin composition. The polymerization catalyst may be preliminarily polymerized with propylene or ethylene.However, in the production method in which main polymerization of propylene is performed thereafter, the amount and molecular weight of the ethylene polymer to be adjusted according to the target physical properties of the composition. Is difficult, so the melt viscosity and melt tension are high,
It is also difficult to obtain a resin composition having good moldability.

When the molecular weight of the propylene polymer produced in the first step and the molecular weight of the ethylene polymer produced in the second step are expressed in terms of intrinsic viscosity, the intrinsic viscosity [η] of the propylene polymer is as follows: 3.0 to 12 (dl / g), preferably 3.4 to 12 (dl / g), more preferably 5 to 12 (dl / g)
１１11 (dl / g). The ethylene polymer has an intrinsic viscosity [η] of 15 to 100 (dl / g), preferably 15 to 60 (dl / g), more preferably 15 to 60 (dl / g).
35 (dl / g). Although a molecular weight regulator such as hydrogen can be added to the polymerization system, in the present invention, since both the propylene polymer and the ethylene polymer are high molecular weight polymers, it is not particularly necessary to supply hydrogen.

In the case of the slurry polymerization method, the polymerization temperature is as follows:
Usually -50 to 100 ° C, preferably 0 to 90 ° C, and in the case of solution polymerization, usually 0 to 250 ° C, preferably 20 to 250 ° C.
200 ° C, in the case of a gas phase polymerization method, usually 0 to 120 ° C,
Preferably, it is 20 to 100 ° C. The polymerization pressure is usually from normal pressure to 100 (kg / cm ² ), preferably from normal pressure to 50 (kg / cm ² ), and the polymerization reaction is performed in any of a batch system, a semi-continuous system, and a continuous system. But you can do it.

As an example of a preferred production method, the first step is a method in which propylene is polymerized under the conditions of so-called bulk polymerization using propylene as a solvent, and the second step is a method in which ethylene is polymerized under gas phase conditions. Can be.
If unreacted propylene is removed from the propylene polymer produced in the first step under an inert atmosphere, the catalyst contained in the propylene polymer is supplied to the second step while maintaining the polymerization activity. Can be. In addition, by adjusting the content of unreacted propylene in the propylene polymer to be transferred to the second step, an ethylene / propylene copolymer having an adjusted propylene content can be produced in the second step. As described above, the production of the ethylene polymer in the second step may be performed in the presence of propylene, and the propylene unit content in the produced ethylene polymer is 0.1 to 15% by weight, preferably 0 to 15% by weight. .1 to 2% by weight
Is desirable.

The usable olefin stereoregular polymerization catalyst may be a Ziegler-Natta catalyst or a metallocene catalyst. Next, as an example of the catalyst system, (a) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, (b)
A catalyst system composed of an organoaluminum compound and (c) an electron donor will be described. When preparing the catalyst, if necessary, the catalyst may be brought into contact with a small amount of propylene or ethylene in advance to carry out preliminary polymerization of propylene or ethylene.

The magnesium component may be a compound having a reducing ability or a compound having no reducing ability. Examples of the compound having a reducing ability include a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond. Specific examples thereof include the following compounds. Further, they may be used in the form of a complex compound with an organoaluminum compound.

(1) Alkyl magnesium compounds such as dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, diamyl magnesium, dihexyl magnesium, didecyl magnesium, ethyl butyl magnesium, butyl ethoxy magnesium, etc. (2) ethyl magnesium chloride, propyl Alkyl magnesium halide compounds such as magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, and amyl magnesium chloride (3) Magnesium hydride compounds such as butyl magnesium hydride

The following compounds can be mentioned as specific examples of the magnesium compound having no reducing property. They may be synthesized in advance or from a magnesium compound having no reducing ability during the preparation of the solid catalyst component. (1) Magnesium halide compounds such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride (2) Alkoxy magnesium halides such as methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy magnesium chloride, and octoxy magnesium chloride Compound (3) Allyloxymagnesium halide compounds such as phenoxymagnesium chloride and methylphenoxymagnesium chloride

(4) Alkoxymagnesium compounds such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium and 2-ethylhexoxymagnesium (5) Allyloxymagnesium compounds such as phenoxymagnesium and dimethylphenoxymagnesium (6) ) Magnesium carboxylate such as magnesium laurate and magnesium stearate

Among these magnesium compounds, magnesium compounds having no reducibility are preferable, magnesium compounds containing halogen are more preferable, and magnesium chloride, alkoxymagnesium chloride and allyloxymagnesium chloride are particularly preferable.

Examples of the titanium component include a tetravalent titanium compound represented by the following formula. Ti (OR) _n X _4-n (wherein, R is a hydrocarbon group, X is a halogen atom, and n is a numerical value of 0 ≦ n ≦ 4)

Examples of such a titanium compound are shown below.
Compounds can be mentioned. (1) TiCl₄, TiBr₄, TiI₄Etc. Tetraha
Titanium logen compounds (2) Ti (OCH₃) Cl₃, Ti (OC₂H₅) C
l₃, Ti (On-C ₄H₉) Cl₃, Ti (OC₂
H₅) Br₃, Ti (O-iso-C₄H₉) Br₃etc
(3) Ti (OCH₃)₂Cl₂, Ti (OC₂H₅)
₂Cl₂, Ti (On-C₄H₉)₂Cl₂, Ti
(OC₂H₅)₂Br₂Dialkoxy such as
Titanium compound

(4) Ti (OCH₃)₃Cl, Ti (O
C₂H₅)₃Cl, Ti (On-C ₄H₉)₃Cl,
Ti (OC₂H₅)₃Monohalogenated trials such as Br
Koxy titanium compound (5) Ti (OCH₃)₄, Ti (OC₂H₅)₄, T
i (On-C₄H₉) ₄, Ti (O-iso-C₄H
₉)₄, Ti (O-2-ethylhexyl)₄Etc tetra
Alkoxy titanium compound

Examples of the electron donor that can be used in preparing the solid catalyst component include alcohols, phenols, ketones, aldehydes, carboxylic acids, organic acid halides, esters of organic or inorganic acids, ethers, acid amides, and the like. Acid anhydride, ammonia, amine, nitrile, isocyanate,
Examples include a nitrogen-containing cyclic compound and an oxygen-containing cyclic compound. Of these, carboxylic acids, carboxylic anhydrides, carboxylic esters, carboxylic halides, alcohols, and ethers are preferably used, and specific examples thereof will be given below.

(1) Alcohols: methanol, ethanol, propanol, butanol, pentanol, hexanol, 2-ethylhexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol C1-C18 alcohols, such as isopropylbenzyl alcohol; and C1-C18 halogen-containing alcohols, such as trichloromethanol, trichloroethanol, and trichlorohexanol.

(2) Phenols: phenols having 6 to 20 carbon atoms which may have a lower alkyl group as a substituent, such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol and naphthol. Kind

(3) Ketones: C3 to C15 ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone and benzoquinone.

(4) Aldehydes: acetaldehyde,
C2-15 aldehydes such as propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, naphthaldehyde

(5) Carboxylic acids: aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, pivalic acid, acrylic acid, methacrylic acid, crotonic acid; malonic acid, succinic acid Acid, glutaric acid,
Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, maleic acid and fumaric acid; aliphatic oxycarboxylic acids such as tartaric acid; cyclohexanemonocarboxylic acid, cyclohexenemonocarboxylic acid, cis-1,2-cyclohexanedicarboxylic acid, cis-4 Alicyclic carboxylic acids such as -methylcyclohexene-1,2-dicarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, anisic acid, p-tert-butylbenzoic acid, naphthoic acid, and cinnamic acid; Phthalic acid, isophthalic acid, terephthalic acid, naphthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, pyromellitic acid, and anhydrides of aromatic polycarboxylic carboxylic acids such as melitic acid include the anhydrides of the carboxylic acids Can be used.

(6) Organic acid halides: acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride and anisic acid chloride

(7) Esters of organic or inorganic acids:
Methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate,
Ethyl crotonate, ethyl cyclohexanecarboxylate,
Dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n
-Butyl phthalate, diisobutyl phthalate, di-n
-Amyl phthalate, diisoamyl phthalate, ethyl-n-butyl phthalate, ethyl isobutyl phthalate, ethyl-n-propyl phthalate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, Phenyl benzoate, benzyl benzoate, methyl toluate,
Ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxy benzoate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, ethyl carbonate, etc.
30 organic or inorganic acid esters

(8) Ethers: methyl ether, ethyl ether, isopropyl ether, butyl ether,
Amyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, diisoamyl ether, dineopentyl ether, dihexyl ether, dioctyl ether,
Methyl butyl ether, methyl isoamyl ether, ethyl isobutyl ether, 2,2-diisobutyl-1,
3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-bis (cyclohexylmethyl) -1,3-dimethoxypropane, 2-isopropyl-2-3,7-dimethyloctyl- 1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2-isopropyl-
2-cyclohexylmethyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-
Dimethoxypropane, 2,2-diisopropyl-1,3
-Dimethoxypropane, 2,2-dipropyl-1,3-
Dimethoxypropane, 2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2-heptyl -2-pentyl-1,3-dimethoxypropane

Next, several examples of a specific method for producing a solid catalyst component will be described. (1) A method in which a solution comprising a magnesium compound, an electron donor, and a hydrocarbon solvent is contact-reacted with an organometallic compound to precipitate a solid, or a contact reaction is performed with a titanium compound while the solid is precipitated. (2) A method in which a complex comprising a magnesium compound and an electron donor is contact-reacted with an organometallic compound, and then a titanium compound is contact-reacted.

(3) A method in which a contact product of an inorganic carrier and an organic magnesium compound is contacted with a titanium compound and preferably an electron donor. At this time, the contact product may be brought into contact with a halogen-containing compound and / or an organometallic compound in advance. (4) An inorganic or organic carrier carrying a magnesium compound is obtained from a mixture of a solution containing a magnesium compound, an electron donor, and possibly a hydrocarbon solvent, and an inorganic or organic carrier, and then contacted with a titanium compound. How to let.

(5) A method of obtaining a solid catalyst component carrying magnesium and titanium by contacting a solution containing a magnesium compound, a titanium compound, an electron donor, and possibly a hydrocarbon solvent with an inorganic or organic carrier. (6) A method of contacting a liquid state organomagnesium compound with a halogen-containing titanium compound. At this time, the electron donor is used once.

(7) A method of contacting a liquid state organomagnesium compound with a halogen-containing compound and then contacting the titanium compound. At this time, the electron donor is used once. (8) A method in which an alkoxy group-containing magnesium compound is contacted with a halogen-containing titanium compound. At this time, the electron donor is used once.

(9) A method comprising contacting a complex comprising an alkoxy group-containing magnesium compound and an electron donor with a titanium compound. (10) A method comprising bringing a complex comprising an alkoxy group-containing magnesium compound and an electron donor into contact with an organometallic compound and then contacting the complex with a titanium compound.

(11) A method of contacting and reacting a magnesium compound, an electron donor, and a titanium compound in an arbitrary order. In this reaction, each component may be pretreated with an electron donor and / or a reaction auxiliary such as an organometallic compound or a halogen-containing silicon compound. In this method, it is preferable to use the electron donor at least once. (12) A method in which a liquid magnesium compound having no reducing ability and a liquid titanium compound are reacted preferably in the presence of an electron donor to precipitate a solid magnesium-titanium composite.

In preparing the solid catalyst component, 0.01 to 5 mol of the electron donor is used per 1 mol of the magnesium compound.
It is preferably used in an amount of 0.1 to 1 mol, and the titanium compound is used in an amount of 0.01 to 1000 mol, preferably 0.1 to 20 mol.
Used in an amount of 0 mol. The halogen / titanium (atomic ratio) is about 2 to 200, preferably about 4 to 100, and the electron donor / titanium (molar ratio) is about 0.01 to 10
0, preferably about 0.2-10, magnesium /
Titanium (atomic ratio) is about 1-100, preferably about 2-5
Desirably, it is 0.

Such a solid catalyst component is used alone.
But can be made of porous materials such as inorganic oxides and organic polymers.
It is also possible to use it supported on a porous substance. Used
The porous inorganic oxide to be used is SiO 2₂, Al
₂O₃, MgO, TiO₂, ZrO ₂, SiO₂-Al
₂O₃Composite oxide, MgO-Al₂O₃Composite oxide, M
gO-SiO₂-Al₂O₃Complex oxides and the like
You.

Examples of the porous organic polymer include polystyrene, styrene-divinylbenzene copolymer, and styrene-
N, N′-alkylene dimethacrylamide copolymer, styrene-ethylene glycol dimethyl methacrylate copolymer, polyethyl acrylate, methyl acrylate-divinyl benzene copolymer, ethyl acrylate-divinyl benzene copolymer, Polymethyl methacrylate, methyl methacrylate-divinyl benzene copolymer, polyethylene glycol methyl methacrylate, polyacrylonitrile, acrylonitrile-divinyl benzene copolymer, polyvinyl chloride, polyvinyl pyrrolidine, polyvinyl pyridine, ethyl vinyl benzene-divinyl benzene Polymers, polyethylene, ethylene-methyl acrylate copolymer, polystyrene such as polypropylene, polyacrylate, polyacrylonitrile, polyvinyl chloride, poly Olefin polymers can be mentioned. Among these porous substances, SiO ₂ ,
Al ₂ O ₃ and a styrene-divinylbenzene copolymer are preferably used.

The organoaluminum compound used together with the solid catalyst component has at least one Al-carbon bond in the molecule. Next, a typical example is shown by a general formula. R ¹ _m AlY _3-m R ² R ³ Al—O—Al R ⁴ R ⁵ (where R ^{1 to} R ⁵ are hydrocarbon groups having 1 to 8 carbon atoms, and they are the same as each other. Y represents a halogen, hydrogen or an alkoxy group, and m is a number represented by 2 ≦ m ≦ 3.)

Specific examples of the organoaluminum compound include trialkylaluminums such as triethylaluminum, triisobutylaluminum and trihexylaluminum, dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride, and mixtures of triethylaluminum and diethylaluminumchloride. And a mixture of a trialkylaluminum and a dialkylaluminum halide, and an alkylalumoxane such as tetraethyldialumoxane and tetrabutyldialumoxane.

Among these organoaluminum compounds, trialkylaluminum, a mixture of a trialkylaluminum and a dialkylaluminum halide, and an alkylalumoxane are preferable, and especially a mixture of triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride,
Alternatively, tetraethyl dialumoxane is preferred.

Specific examples of the electron donor used together with the solid catalyst component and the organoaluminum compound include the following compounds. (1) Compound containing nitrogen atom: 2,2,6,6-tetramethylpiperidine, 2,6-dimethylpiperidine, 2,
6-diethylpiperidine, 2,6-diisopropylpiperidine, 2,6-diisobutyl-4-methylpiperidine, 1,2,2,6,6-pentamethylpiperidine,
2,2,5,5-tetramethylpyrrolidine, 2,5-dimethylpyrrolidine, 2,5-diethylpyrrolidine, 2,
5-diisopropylpyrrolidine, 1,2,2,5,5-
Pentamethylpyrrolidine, 2,2,5-trimethylpyrrolidine, 2-methylpyridine, 3-methylpyridine,
-Methylpyridine, 2,6-diisopropylpyridine,
2,6-diisobutylpyridine, 1,2,4-trimethylpiperidine, 2,5-dimethylpiperidine, methyl nicotinate, ethyl nicotinate, nicotinamide, benzoamide, 2-methylpyrrole, 2,5-dimethylpyrrole , Imidazole, toluic acid amide, benzonitrile, acetonitrile, aniline, paratoluidine, orthotoluidine, metatoluidine, triethylamine,
Diethylamine, dibutylamine, tetramethylenediamine, tributylamine.

(2) Compounds containing a sulfur atom: thiophenol, thiophene, ethyl 2-thiophenecarboxylate, ethyl 3-thiophenecarboxylate, 2-methylthiophene, methylmercaptan, ethylmercaptan, isopropylmercaptan, butylmercaptan, diethylthioether , Diphenylthioether, methylbenzenesulfonate, methylsulfite, ethylsulfite.

(3) Compounds containing an oxygen atom: tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2-ethyltetrahydrofuran,
2,2,5,5-tetraethyltetrahydrofuran,
2,2,5,5-tetramethyltetrahydrofuran,
2,2,6,6-tetraethyltetrahydropyran,
2,2,6,6-tetramethyltetrahydropyran, dioxane, dimethyl ether, diethyl ether, dibutyl ether diisoamyl ether, diphenyl ether, anisole, acetophenone, acetone, methyl ethyl ketone, acetyl acetone, o-tolyl-t-butyl ketone, methyl-2, 6-di-t-butylphenyl ketone, 2-ethyl furarate, isoamyl 2-furate,
2-methyl furarate, propyl 2-furarate.

[0075] (4) an organic silicon compound: formula R _n Si (OR _') is preferably a compound represented by _4-n, the following specific examples. (Where R and R ′ are hydrocarbon groups, and n is 0 <n <
It is a numerical value of 4. )

Trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-tolyldimethoxysilane, bism-tolyldimethoxy Silane,
Bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, bisethylphenyldimethoxysilane,
Ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, Methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, n-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane , Ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyl tris (β-methoxyethoxy silane), vinyl triacetoxy silane, Methyl tetraethoxy disiloxane.

The organoaluminum compound has a molar ratio per mole of Ti atoms in the solid catalyst component of from 5 to 1000, and the electron donor has a molar ratio per mole of the organoaluminum compound of from 0.002 to 0.5. It is preferable that

Method for Producing Resin Composition (2) The polypropylene resin composition produced by the method described above is
Further, the composition has a specific energy of 0.25 (kw / k).
g) By performing a melt-kneading operation under the conditions described above, a resin composition having a higher melt tension can be modified.

The melt-kneading operation is performed by a kneader such as a co-kneader, a Banbury mixer, a Brabender, a single-screw extruder, a twin-screw extruder, a horizontal stirrer such as a twin-screw multi-disc device, or a double helical ribbon stirrer. It can be performed using a vertical stirrer or the like.

At the time of the melt kneading, the kneader or the stirrer and the kneading conditions are selected so that the specific energy applied to the molten resin is 0.25 (kw / kg) or more. Kneading with a twin-screw extruder is preferable because a sufficient kneading effect can be obtained and the productivity is excellent. As the kneading conditions, the heating temperature is 170 to 250.
° C, preferably 180-220 ° C, and the melt-kneading time is 1
0 to 5 minutes, preferably 30 to 60 seconds is desirable.
In addition, in order to sufficiently uniformly mix the respective materials, the above-described melt-kneading operation may be repeated a plurality of times.

Here, the specific energy applied to the molten resin is:
It can be obtained from the following equation. Specific energy = (W−W ₀ ) / Q W: power consumption (kw / h) when the extruder is run idle
r) W ₀ : power consumption when melting and kneading the resin composition in the extruder (kw / hr) Q: extrusion rate of the resin composition (kg / hr)

When the melt kneading operation is performed by adding an organic peroxide to the resin composition, the effect of increasing the melt tension can be further enhanced. At that time, if the kneading operation is performed under the condition that the organic peroxide is almost completely decomposed, a weakly crosslinked polypropylene resin composition can be obtained, and the property of the resin is hardly further changed in the subsequent molding step. Absent.

The usable organic peroxide is represented by the following general formula. R ¹ —O—R ² Here, R ¹ and R ² are a hydrocarbon group having 1 to 30 carbon atoms, and in the hydrocarbon group, an oxygen atom, a halogen atom, a nitrogen atom, a sulfur atom, It may contain a silicon atom, and R ¹ and R ² may be the same or different.

Next, specific examples of R ¹ and R ^{2 will be described} .
In addition, i is iso, t is tertiary, z is cis,
c means cyclic.

(1) Chain saturated hydrocarbon group: CH ₃ , C _{2
H 5, C 3 H 7,} i-C 3 H 7, C 4 H 9, i-C 4 H
_{9, t-C 4 H 9} , C 2 H 5 CH (CH 3), C 5 H
_{11, (CH 3) 3 CCH} 2, C 6 H 13, (CH 3)
₂ CHCH ₂ CH (CH ₃ ), C ₇ H ₁₅ , C
_{8 H 17, C 4 H 9} (C 2 H 5) CH 2, C 6 H 13 C
H (CH ₃ ), C ₁₂ H ₂₅ , C ₁₃ H ₂₇ , C ₁₄ H
₂₉ , C ₁₅ H ₃₁ , C ₁₈ H ₃₇ , stearyl group

(2) cyclic saturated hydrocarbon group: 4-tC _{4
H 9 -c-C 6 H 10} , c-C 6 H 11, c-C 6 H
_{11 CH 2, 2-i-} C 3 H 7 -5-CH 3 -c-C 6
H ₉ , c-C ₁₂ H ₂₃

(3) Aromatic hydrocarbon group: C ₆ H ₅ , C _{6
H 5 CH 2, 2-CH} 3 -C 6 H 4, 3-CH 3 -C 6
_{H 4, 4-CH 3 -C} 6 H 4, 2-i-C 3 H 7 -C 6
_{H 4, 3-t-C} 4 H 9 -C 6 H 5, 4-t-C 4 H 9
-C ₆ H _4, 3,4- di _-CH 3 _-C 6 _H 3, 3,5-
Di _{-CH 3 -C 6 H 3, 3} -CH 3 -5-i-C 3 H 7
—C ₆ H ₃ , 2-C ₂ H ₅ CH (CH ₃ ) —C ₆ H ₄ ,
1-naphthyl group, 9-florenyl group

(4) Chain unsaturated hydrocarbon group: H ₂ C ＝ C
HCH ₂ , H ₂ C ＝ C (CH ₃ ), H ₂ C ＝ C (C
_{H 3) CH 2, H 2} C = CH-i-C 3 H 6, z-C 8
H ₁₇ CH = CH (CH ₂ ) ₈

(5) Oxygen-containing chain hydrocarbon group: C ₂ H ₅
OCH ₂ CH ₂ , CH ₃ OCH ₂ CH ₂ , CH ₃ OCH
₂ CH (CH ₃ ), CH ₃ OC (CH ₃ ) ₂ CH ₂ CH
₂ , CH ₃ OCH ₂ CH ₂ , C ₃ H ₇ OCH ₂ CH ₂ ,
C ₄ H ₉ OCH ₂ CH ₂ , CH ₃ CH (OCH ₃ ) CH
₂ CH ₂

(6) Oxygen-containing aromatic hydrocarbon group: 4-C
H ₃ O—C ₆ H ₄ , 2-iC ₃ H ₇ —O—C ₆ H ₄ ,
C ₆ H ₅ OCH ₂ CH ₂

(7) Halogenated hydrocarbon group: Cl ₃ C,
Cl ₃ CCH ₂ , Cl ₃ CC (CH ₃ ) ₂ , ClC
_{H 2, ClCH 2 CH 2,} CH 3 CH (Cl), C 2 H
₅ CH (Cl) CH ₂ , C ₆ H ₅ CH (Cl) CH ₂ ,
_{2-Cl-c-C 6} H 10, 2,4,5- tri -Cl-
C ₆ H ₂ , BrCH ₂ CH ₂ , Br ₃ CCH ₂

(8) Other hydrocarbon groups: 4-NO _{2-
C 6 H 4 CH 2, 4-} [C 6 H 5 -N = N] -C 6 H 4
CH ₂ , CH ₃ SO ₂ CH ₂ CH ₂ , [C ₂ H ₅ OC
_{(O)] 2 CH (CH} 2), 2- oxo-1,3-dioxane _{-4-CH 2, Cl 3 Si} (CH 2) 3

Among these R ¹ and R ² ,
A linear or branched alkyl group having 1 to 20 carbon atoms, or a chain unsaturated hydrocarbon group is preferred.

Preferred specific compounds are 2,5
-Dimethyl-2,5-di {(t-butylperoxy) hexane, 2,5-dimethyl-2,5-di} (t-butylperoxy) hexyne-3 and the like. In particular, 2,5-dimethyl-2,5-di {(t-butylperoxy) hexane is preferable because of its excellent crosslinking effect.

The organic peroxide is added in an amount of 0.01 to 1 part by weight, preferably 0.04 to 0.5 part by weight, more preferably 0.05 to 0.1 part by weight, based on 100 parts by weight of the polypropylene resin composition. 2 parts by weight. Within this range, a high modifying effect of the resin composition can be obtained, and there is little possibility that a gel component is generated.

The above-mentioned organic peroxide is added to the resin composition.
If necessary, other additives are added, and first dry-blended uniformly using a ribbon blender, a tumbler blender, a Henschel blender or the like, and then the above-described melt-kneading operation is added. Since the resin composition thus obtained has high melt viscosity and melt tension, it is excellent in foam moldability and subsequent secondary workability,
Further, there is almost no discoloration or odor derived from the decomposition product of peroxide, and the food hygiene is good.

When the resin composition is melt-kneaded in the presence of an organic peroxide, vinyl monomers can coexist. Examples of such vinyl monomers include the following compounds.

(1) Vinyl chloride, vinylidene chloride, styrene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl acetate, acrylic acid, methacrylic acid, maleic acid, maleic anhydride (2) Metals of acrylic acid and methacrylic acid salt

(3) Acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, glycyl acrylate, etc. (4) Methyl methacrylate, ethyl methacrylate, methacrylic acid Butyl, 2-ethylhexyl methacrylate,
Methacrylates such as stearyl methacrylate and glycyl methacrylate

Foamed body The foamed body according to the present invention contains closed cells produced by subjecting the above-mentioned polypropylene resin composition or the polypropylene resin composition obtained by the above-mentioned production method to foam molding into a sheet. And has excellent heat resistance.

Such a foam is produced by adding a foaming agent to a polypropylene resin composition and extruding it. As the foaming agent, any of a gaseous foaming agent, a volatile foaming agent and a decomposition foaming agent can be used, and these foaming agents may be used alone or in combination of two or more. May be used. The foaming agent can be previously compounded in the composition, or can be compounded by providing an injection port in a cylinder of an extruder and supplying the foaming agent therefrom. Next, each foaming agent will be described.

(1) Gaseous foaming agent A gaseous foaming agent is injected from a cylinder of an extruder, dispersed and dissolved in a composition in a molten state, and then the pressure is released when the composition is extruded from a die. And thus function as a foaming agent for the composition. For example, carbon dioxide, nitrogen, argon and the like can be mentioned.

(2) Volatile foaming agent Like the gaseous foaming agent, the volatile foaming agent is injected from the cylinder of the extruder to be absorbed or dissolved in the molten composition and then evaporated when extruded from the die. It is a substance that functions as a foaming agent. Next, specific examples will be given.

(1) Low-boiling aliphatic hydrocarbons such as propane, butane, pentane, neopentane, hexane, isohexane and heptane (2) Alicyclic hydrocarbons such as cyclobutane, cyclopentane and cyclohexane

(3) Chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, dichloromethane, dichlorofluoromethane, dichlorodifluoromethane, trichlorofluoromethane, chloromethane, chloroethane, dichlorotrifluoroethane, dichlorofluoroethane, chlorodifluoroethane , Dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, tetrachlorodifluoroethane, chloropentafluoroethane, halogenated hydrocarbons such as perfluorocyclobutane

(3) Decomposition type foaming agent The decomposition type foaming agent is supplied to an extruder after being previously blended with the composition, and the foaming agent is decomposed under the cylinder temperature condition of the extruder, and carbon dioxide gas, nitrogen gas, etc. It is a compound that generates gas. An inorganic foaming agent may be used, or an organic foaming agent may be used.Citric acid that promotes gas generation, or an organic acid such as sodium citrate or an organic acid salt may be added in combination. Good. Specific examples of the decomposition type foaming agent include the following compounds.

(A) Inorganic foaming agent: sodium bicarbonate,
Sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite

(B) Organic blowing agents: (1) N-nitroso compounds such as N, N'-dinitrosoterephthalamide, N, N'-dinitrosopentamethylenetetramine (2) azodicarbonamide, azobisiso Azo compounds such as butyronitrile, azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate (3) benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p, p'-oxybis (benzenesulfenyl hydrazide), diphenylsulfone-
Sulfonyl hydrazide compounds such as 3,3'-disulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide and p-toluenesulfonyl azide.

The amount of the foaming agent to be added is selected in consideration of the amount of gas generated from the foaming agent, the desired expansion ratio, and the like, depending on the desired properties of the foamed article. Usually, 0.1 to 10 parts by weight based on 100 parts by weight of the polypropylene resin composition,
Preferably, 0.5 to 5 parts by weight is desirable. When it is within this range, a foam molded article having a more uniform cell diameter can be obtained.

In order to control the cell diameter of the foam to an appropriate size, a foam nucleating agent such as talc may be used as needed. The amount of the foaming nucleating agent is usually 0.00.0 parts by weight based on 100 parts by weight of the polypropylene resin composition.
1-2 parts by weight are preferred.

When a decomposable foaming agent is used, both the polypropylene resin composition and the foaming agent are supplied to an extruder, and the foaming agent is thermally decomposed while melting and kneading the resin composition at an appropriate temperature to form a foaming agent. Gas is generated. Then
When the molten polypropylene resin composition containing this gas is discharged from a die, a foam can be produced. The melt-kneading temperature and the melt-kneading time may be appropriately selected depending on the foaming agent used and the kneading conditions.
The temperature is preferably 170 to 300 ° C., and the time is preferably 1 to 60 minutes.

When a volatile foaming agent or a gaseous foaming agent is used, the polypropylene resin composition is melted in an extruder, the foaming agent is pressed into the extruder, and the resin composition in a molten state is maintained at a high pressure. And extrude from a die.
The melt-kneading temperature and the melt-kneading time may be appropriately selected depending on the foaming agent to be used and the kneading conditions, and vary depending on the type of the resin.

Regardless of which foaming agent is used, the resin composition melted in the extruder can be formed into a sheet-like foam having independent foam cells by discharging it from a T-die or a circular die. When discharged from a circular die, the extruded cylindrical sheet is cut into one or more pieces and wound up as a smooth sheet.

The foam according to the present invention has an expansion ratio of 1.
3-10 fold, preferably a 1.6 to 6 times, the density of the foam is 0.09~0.6 (g / ^cm 3), preferably 0.15~0.3 (g / cm ³ ) Is desirable. Such a foam is excellent in lightness, heat insulation, cushioning against external stress, and compressive strength. Further, the closed cell rate is desirably 50% or more, preferably 70% or more. When the closed cell rate is in such a range, the cushioning property against external force is good, and the compressive strength is excellent.

This sheet-like foam can then be formed into a tray or container shape by secondary forming such as vacuum forming or compressed air forming. At this time, the heated sheet-like material is difficult to draw down, so The productivity of the next molded article is high and gives a good shape. The secondary molded foam is lightweight, has high rigidity, is excellent in chemical resistance and food hygiene, is well-shaped, and has a beautiful appearance, so packaging materials for fresh foods and processed foods, In particular, it can be used for cup ramen and ice cream containers, fish and meat trays, and the like.

[0116]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 (Preparation of Solid Titanium Catalyst Component) 7.14 g of anhydrous magnesium chloride, 37 ml of decane, and 35.1 ml of 2-ethylhexyl alcohol were heated and reacted at 130 ° C. for 2 hours to form a homogeneous solution. . Thereafter, 1.67 g of phthalic anhydride was added to the solution, and the mixture was further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in the homogeneous solution. After cooling the obtained homogeneous solution to room temperature,
Was dripped over 1 hour into 200 ml of titanium tetrachloride held in the above. Thereafter, the temperature of the mixed solution was raised to 110 ° C. over 4 hours. When the temperature reached 110 ° C., 4.0 ml of isobutyl phthalate was added, and stirring was further continued for 2 hours. After completion of the reaction, a solid portion was collected by hot filtration, and the solid portion was resuspended in 275 ml of titanium tetrachloride. Thereafter, a heating reaction was performed again at 110 ° C. for 2 hours.
After completion of the reaction, a solid portion was collected again by hot filtration, and
Washing was sufficiently performed using decane and hexane at 0 ° C. until no free titanium compound was detected in the washing solution. A solid titanium catalyst component in the form of spherical particles was obtained.

(Preparation of polymerization catalyst) Under a nitrogen atmosphere, 4 l of heptane, 0.15 mol of triethylaluminum, 0.03 mol of dicyclopentyldimethoxysilane, and 0.03 mol of the solid titanium catalyst component were placed in a 7 l polymerization vessel equipped with a stirrer under a nitrogen atmosphere. 37 g were fed. Thereafter, 60 Nl of propylene was supplied to perform prepolymerization of propylene. The resulting polymerization catalyst contained a ratio of polypropylene to solid titanium catalyst component of 3: 1.

(First Step: Polymerization of Propylene) Content 6
200 l of a polymerization tank equipped with a stirrer was replaced with nitrogen, 200 l of liquid propylene was supplied, and the temperature was raised to 70 ° C. Next, the polymerization catalyst was added in an amount of 2.5 (g / g) per solid titanium catalyst component.
h), 0.1 (mol / h) of triethylaluminum,
And dicyclopentyldimethoxysilane at 0.02
(Mol / h). In addition, liquid propylene was supplied at 73 (kg / h). The produced polypropylene and unreacted propylene were continuously discharged in order to adjust the liquid level in the polymerization tank to keep 200 l.

The polypropylene discharged from the polymerization tank was
Separated from unreacted propylene using a bag filter,
The unreacted propylene remaining in the polypropylene powder introduced into the dryer was removed by nitrogen gas. The polypropylene produced here was 22 (kg / h) and had an intrinsic viscosity [η] of 10.0 (dl / g).

(Second Step: Polymerization of Ethylene) Then, the above-mentioned polypropylene powder was introduced into a polymerization tank having a content of 170 l, and ethylene gas was supplied at 1.0 (Nm ³ / h) and nitrogen gas was supplied at 15 (Nm ³ / h). h), and a gas phase polymerization of ethylene was carried out under the conditions of a polymerization temperature of 40 ° C., a polymerization pressure of 1.6 (kg / cm ² G) and a residence time of 3 hours.

The produced amount of the polymer composition was 23
(Kg / h) and its intrinsic viscosity [η] is 10.3 (dl)
/ G) and the ethylene unit content was 5.6% by weight. From the intrinsic viscosities [η] of the polypropylene obtained in the first step and the polymer composition obtained in the second step, the intrinsic viscosity [η] of the polyethylene produced in the second step is 20 (d)
1 / g). The production conditions and production results are shown in Table 1.

(Examples 2 to 3) In Example 1, instead of continuously supplying ethylene and nitrogen in predetermined amounts in the second stage, ethylene, propylene and nitrogen were continuously supplied in predetermined amounts shown in Table 1. The procedure was performed in the same manner as in Example 1 except that The polymerization results are also shown in Table 1. The ethylene content was measured by an infrared absorption spectrum.

(Reference Examples 1 and 2) A resin composition was produced in the same manner as in Example 1 except that the polymerization conditions in the second stage were changed as shown in Table 2, and the other conditions were the same. .
Table 2 shows the production results.

[0125]

[Table 1] (Note) PP: propylene polymer PE: ethylene polymer

[0126]

[Table 2]

Example 4 100 parts by weight of the resin composition prepared in Example 1 was added to 2,5-dimethyl-2,5-di (t-
0.08 parts by weight of butylperoxy) hexane was added,
Same-direction fully meshing twin screw extruder (Technobel Co., Ltd., KZW25-30MG type, screw diameter 31mm)
(φ, L / D = 30) and melt-kneaded under the conditions of a resin temperature of 210 ° C. and a screw rotation speed of 200 rpm (average residence time: 30 seconds) to obtain pellets of a modified polypropylene resin composition. The melt flow rate (MFR) and melt tension (MT) of the modified polypropylene resin composition pellets were measured, and the results are shown in Table 3.

The MFR and MT were measured by the following test methods. (1) MFR: 23 according to ASTM D-1238
It was measured under the conditions of 0 ° C. and a load of 2.16 kg. (2) MT: Orifice (L = 8.00 m) using a melt tension measuring device (manufactured by Toyo Seiki Seisaku-sho, Ltd.)
m, D = 2.095 mm), set temperature: 230 ° C., piston descending speed 30 (mm / min), winding speed 4 (mm /
), The winding load (g) of the pulley with the load cell detector was measured.

(Embodiment 5) In Embodiment 4, Embodiment 1
In the same manner as in Example 4 except that the resin composition obtained in Example 2 was used instead of the resin composition obtained in Example 4, a modified polypropylene resin composition was obtained. Table 3 shows the measurement results of the physical properties.

(Embodiment 6) In Embodiment 4, Embodiment 1
In the same manner as in Example 4 except that the resin composition obtained in Example 3 was used instead of the resin composition obtained in Example 4, a modified polypropylene resin composition was obtained. Table 3 shows the measurement results of the physical properties.

(Reference Example 3) In Embodiment 4, Embodiment 1
In the same manner as in Example 4 except that the resin composition obtained in Reference Example 1 was used in place of the resin composition obtained in Example 4, a modified polypropylene resin composition was obtained. Table 3 shows the measurement results of the physical properties.

(Reference Example 4)
In the same manner as in Example 4 except that the resin composition obtained in Reference Example 2 was used in place of the resin composition obtained in Example 4, a modified polypropylene resin composition was obtained. Table 3 shows the measurement results of the physical properties.

[0133]

[Table 3]

Example 7 100 parts by weight of pellets of the polypropylene resin composition produced in Example 4 were mixed with a blowing agent masterbatch (a product of Dainichi Seika Co., Ltd., trade name: PE-RM).
(410EN, sodium bicarbonate / citric acid blended product) 3 parts by weight was added and mixed for 3 minutes using a tumbler blender.

This mixture was mixed with a 65 mm single screw extruder (L / D
= 28). At the tip of the extruder, a circular die of 80 mmφ and a mandrel of 190 mmφ are provided. The resin was extruded from the die under the condition of a swelling ratio of 2.4 to form a 0.8 mm thick annular foam sheet. One corner of the annular foam sheet was cut open and taken out as a smooth sheet by a take-off machine. The expansion ratio, appearance, cell shape, strain hardening property, drawdown property, and secondary moldability (vacuum moldability) of the obtained foamed sheet were evaluated. The results are shown in Table 4.

The measurement and evaluation of physical properties were performed by the following methods. (1) Expansion ratio: The apparent density (D) was calculated from the weight and the volume obtained by the submerged method, and the true specific gravity (0.90) was divided by the apparent density (D). That is, expansion ratio = 0.90 / D

(2) Appearance of the sheet: Visually evaluated according to the following evaluation criteria in four stages of ◎ to ○ to △ to ×. ：: No unfoamed portion, unevenness and corrugate are observed. ×: Unfoamed portions, irregularities, corrugates are seen.

(3) Cell shape: SE section of foamed sheet
M observation, taking into account the presence or absence of closed cells and continuity,
The evaluation was made in four stages of Δ to ×.

(5) Strain hardening property: using a Meissner-type Melten Rheometer (manufactured by Toyo Seiki Co., Ltd.) with a diameter of 5 mm.
A 300 mm long cylindrical strand was prepared, which was then immersed and melted in silicone oil at 180 ° C. After 5 minutes, the sheet was sandwiched between tension rolls with a load cell having a fixed chuck distance of 130 mm, and the strain rate was 0.1%.
The strand was subjected to elongation deformation under the condition of a rotation speed of sec- ¹ , and the elongation viscosity was measured. At the time of this measurement, the tension value detected by the load cell with respect to the elapsed time was plotted on a graph, and the tension at the yield point (YT) and the tension at the break point (BT) were measured from the graph. The value of BT / YT was calculated from the value and used as an index of strain hardening.

(4) Drawdown property: 50 mm in diameter
Using a mold capable of simultaneously vacuum forming three cups having a depth of 30 mm, 40 mm, and 50 mm, the sheet was heated to 160 ° C.
When the sheet was heated for 1 minute and vacuum formed, the hanging distance (mm) of the sheet was measured by infrared rays. From the results, the quality of the drawdown property was evaluated in three stages of ○ to △ to ×.

(6) Secondary formability: Using a mold capable of simultaneously vacuum forming three cups having a diameter of 50 mm and a depth of 30 mm, 40 mm, and 50 mm, the sheet was heated at 160 ° C. for 2 hours.
After heating for minutes, vacuum forming was performed, and the secondary formability was evaluated from the shape and appearance of the formed cup. (A) The shape of the cup was visually observed and determined to be extremely good (）), good (○), and bad (x). (B) The appearance of the cup was visually observed for surface conditions, uneven wall thickness of the cup wall surface, breakage of the wall surface, and the like. .

(Embodiment 8) In Embodiment 7, Embodiment 4
A vacuum molded article was obtained in the same manner as in Example 7, except that the resin composition obtained in Example 5 was used instead of the resin composition obtained in Example 5. Table 4 shows the measurement results of the physical properties.

(Embodiment 9) Embodiment 7 is different from Embodiment 7 in Embodiment 4.
A vacuum molded product was obtained in the same manner as in Example 7, except that the resin composition obtained in Example 6 was used instead of the resin composition obtained in Example 6. Table 4 shows the measurement results of the physical properties.

(Comparative Example 1) In Example 7, Example 4
A vacuum molded product was obtained in the same manner as in Example 7, except that the resin composition obtained in Reference Example 3 was used in place of the resin composition obtained in. Table 4 shows the measurement results of the physical properties.

(Comparative Example 2) In Example 7, Example 4
A vacuum molded product was obtained in the same manner as in Example 7, except that the resin composition obtained in Reference Example 4 was used in place of the resin composition obtained in Example 4. Table 4 shows the measurement results of the physical properties.

[0146]

[Table 4]

[0147]

The polypropylene resin composition of the present invention contains a high melt viscosity and a high melt tension because it contains a high molecular weight propylene polymer and a high molecular weight ethylene polymer. The viscosity rises sharply during deformation. Such a resin composition is suitable for foam molding, and can produce a foamed sheet having high rigidity and a closed cell rate. Further, according to the method for producing a polypropylene resin composition of the present invention, a polypropylene resin composition having the above-described physical properties can be produced with high productivity.

Further, the foamed sheet molded from the above-mentioned resin composition hardly causes drawdown in the heating step at the time of secondary molding such as vacuum molding. Therefore, it is suitable as a sheet for efficiently producing secondary molded products such as cups and trays having good appearance, heat resistance, and excellent food hygiene.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/10 ZAB C08L 23/10 ZAB // (C08L 23/10 23:04) C08L 23:04 (72 ) Inventor Mikio Hashimoto 580-30 Nagaura, Sodegaura City, Chiba Prefecture Within Grand Polymer Co., Ltd. (72) Inventor Naoya Akiyama 580-30 Nagaura Sodegaura City, Chiba Prefecture Within Grand Polymer Co., Ltd. 580-30 Ichi-Nagaura Inside Grand Polymer Co., Ltd. (72) Inventor Yoichi Wakita 580-30 Nagaura Sodegaura-shi, Chiba Pref. Inside Grand Polymer Co., Ltd. F term (reference) 4F074 AA17 AA24 AA25A AB05 BA01 BA02 BA03 BA04 BA05 BA12 BA13 BA14 BA17 BA18 BA31 BA32 BA33 BA36 BA37 BA39 BA40 BA42 BA43 BA44 BA45 BA47 BA53 BA54 BA55 BA56 BA57 BA58 BA59 CA22 DA02 DA32 DA33 D A34 DA59 4J002 BB032 BB042 BB121 BB141 BB152 EK006 EK036 FD320 GG01 GL00 4J011 PA64 4J026 AA13 BA02 DA02 DB01 GA02

Claims (12)

[Claims] 1. A composition obtained by producing a propylene polymer in a first step and subsequently producing an ethylene polymer in a second step, wherein the composition comprises 85 to 99% by weight of propylene polymer. The intrinsic viscosity [η] of the coalesce is 3.0 to 12 (d
1 / g), and the intrinsic viscosity [η] of the ethylene polymer contained in the composition in the range of 1 to 15% by weight is 15 to 100.
(Dl / g). 2. The polypropylene resin composition according to claim 1, wherein the propylene polymer is a propylene homopolymer. 3. The polypropylene resin composition according to claim 1, wherein the ethylene polymer is an ethylene homopolymer. 4. The polypropylene resin composition according to claim 1, wherein said ethylene polymer is an ethylene / propylene copolymer having a propylene unit content of 0.1 to 15% by weight. 5. In the first step, the intrinsic viscosity [η] is 3.0 to 12
(Dl / g) in the presence of the propylene polymer containing a catalyst whose polymerization activity is retained in the subsequent second step, with an intrinsic viscosity [η] of 15
~ 100 (dl / g) ethylene polymer is produced, the propylene polymer occupying 85 to 99% by weight in the obtained composition and the ethylene polymer is 1 to 15% by weight. A method for producing a polypropylene resin composition. 6. The second step is characterized in that the polymerization of ethylene is carried out in the presence of propylene, and the propylene unit content in the ethylene polymer produced therefrom is 0.1 to 15% by weight. A method for producing the polypropylene resin composition according to claim 5. 7. The method according to claim 5, wherein the first step polymerizes propylene under a condition in which propylene is used as a solvent, and the second step polymerizes ethylene under a gas phase condition. Or the method for producing a polypropylene resin composition according to item 6. 8. After the resin composition is produced by the method according to any one of claims 5 to 7, the composition is further melt-mixed under the condition that the specific energy becomes 0.25 (kw / kg) or more. A method for producing a polypropylene resin composition, comprising adding a kneading operation. 9. The method for producing a polypropylene resin composition according to claim 8, wherein the melt-kneading operation is performed in the presence of an organic peroxide. 10. The organic peroxide as claimed in claim 1, wherein the organic peroxide is 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3. 10. The method according to claim 9, wherein
The method for producing a polypropylene resin composition according to the above. 11. A polypropylene resin foam which is formed into a sheet from the polypropylene resin composition according to any one of claims 1 to 4, and contains closed cells therein. 12. A polypropylene resin foam which is formed in a sheet from the polypropylene resin composition produced by the method according to any one of claims 5 to 10, and contains closed cells therein. .