JP3010516B2 - Method for producing modified propylene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified propylene polymer, which is excellent in transparency, mechanical strength, and moldability, and particularly excellent in rigidity and moistureproofness useful as a material for food packaging and containers. It is intended to provide a method for producing a modified propylene-based polymer.

[0002]

2. Description of the Related Art Polypropylene is inexpensive and has excellent mechanical strength, heat resistance, oil resistance, and electrical properties.
It is widely used in various applications as films, fibers, molded products and the like.

[0003] However, polypropylene is rigid,
It is inferior to other vinyl polymers, especially polystyrene, in terms of sheet workability, surface properties, and the like. For example, in the field of packaging containers, polypropylene has drawbacks such as lower rigidity than polystyrene and difficulty in sheet processing.
On the other hand, however, it has advantages such as superiority to polystyrene in heat resistance, oil resistance and moisture resistance. Therefore, if a molding material having the advantages of polypropylene and the advantages of polystyrene in a well-balanced manner can be obtained, it is expected that it can be used in application fields that could not be used conventionally.

Attempts have been made to blend polypropylene with polystyrene or to polymerize styrene in the presence of a propylene polymer. JP-A-59-217
No. 742 discloses a modified polypropylene obtained by polymerizing a styrene monomer in an aqueous suspension in the presence of a propylene polymer. JP-A-4-213313 discloses a modified polypropylene obtained by activating a granular propylene-based polymer with a peroxide, adding a styrene-based monomer, and polymerizing the propylene-based polymer under a condition capable of maintaining the granularity by a solid phase system. Is disclosed.

[0005] However, polypropylene and polystyrene are incompatible with each other, and if they are simply blended, the interfacial adhesion between the two resins is poor, so that the polystyrene portion is insufficiently dispersed to cause phase separation, and the resulting molded article is transparent. The mechanical properties such as properties, rigidity and impact resistance are unsatisfactory and are not practical. In the case of polymerizing a styrene monomer in an aqueous suspension or solid phase in the presence of a powdery propylene polymer, the process is complicated, such as blocking, controlling the polymerization temperature, and drying the product. Therefore, there was a difficulty in industrialization as a general-purpose polymer.

As described above, introduction of a styrene-based polymer into a propylene-based polymer by a conventional method has a problem in terms of polymer performance.
Or it was not satisfactory in manufacturing. This is due to insufficient dispersion of polystyrene in the propylene-based polymer. And in order to sufficiently disperse polystyrene, although the presence of a graft polymer of a propylene-based polymer and polystyrene is desirable, polypropylene is
In the first place, since it is highly crystalline, first of all, it has a high melting point, and then it does not dissolve in the styrene monomer.
It is considered that the graft polymer is hardly formed.

[0007]

However, the problem to be solved by the present invention is to solve all of the drawbacks in the prior art, and it is extremely practical to have excellent transparency, mechanical strength and moldability. An object of the present invention is to provide a method for producing a modified propylene-based polymer having a high property.

Therefore, the present inventors have solved the above-mentioned conventional methods, namely, the problems to be solved by the above-mentioned invention in order to solve the problems of transparency, mechanical strength, moldability and the like. As a result of diligent and intensive studies, first, by polymerizing an aromatic vinyl monomer in the presence of a propylene polymer in a molten state, such as in an extruder A patent application has been filed on the finding that a graft polymer having excellent properties can be obtained and that it can be easily produced industrially. (Japanese Patent Application No. 3-136485, Japanese Patent Application No. 3-324533, Japanese Patent Application No. 3-324534)

As a result of further studies, the present inventors have found that, before producing the graft polymer, a propylene polymer is impregnated with a vinyl monomer mainly composed of aromatic vinyl beforehand. After that, it was found that, by performing a melt-kneading polymerization reaction, for the first time, excellent supply properties to a continuous kneader such as an extruder were achieved, and excellent physical properties were balanced with a high polymerization rate and a high grafting rate.

[0010]

That is, the present invention relates to a powdery propylene polymer (a) containing at least 5% by weight of a vinyl monomer (b) containing an aromatic vinyl as a main component. (In total weight with the propylene-based polymer (a)), a radical polymerization initiator is added if necessary, and the vinyl-based monomer (b) and the radical polymerization initiator (c) are added to the polymer (a). After substantially impregnating, a method for producing a modified propylene-based polymer, characterized by homogenously melt-kneading and polymerizing the vinyl-based monomer, preferably a vinyl-based monomer (b) or The angle of repose X of the powdery propylene polymer (a) impregnated with the monomer (b) and the radical polymerization initiator (c) is (X = 12.7 + 1.62 × amount of vinyl monomer + 105 × 1 / t + 567 × 1 / T) ≦ 70 were mixed so that a °, reforming, characterized in that the polymerization reaction of the vinyl monomer homogeneously kneaded Pro To provide a process for the preparation of alkylene polymer.

[0011]

The above-mentioned powdery propylene-based polymer used in carrying out the method of the present invention is a homopolymer of propylene and other olefins or ethylenically unsaturated monomers containing propylene as a main component. (All of which are copolymers containing 75% by weight or more of propylene), and specifically,
Isotactic polypropylene, crystalline propylene
Ethylene copolymer, crystalline propylene-butene copolymer, maleic anhydride-modified polypropylene, and the like are typical examples of the propylene-based polymer. Two or more of these propylene-based polymers can be used as a mixture. Preferably, a propylene homopolymer is used.

In the present invention, other powdery polymers can be used as long as the properties of the powdery propylene polymer are not impaired. However, a radically crosslinkable powdery polymer such as polyethylene is preferably reduced to a half or less since a kneading torque is increased by network formation during melt kneading.

The powdery propylene polymer used in the present invention preferably has a large particle surface area in order to facilitate impregnation with an aromatic vinyl monomer. From such a point, it is preferable that the polymer has a porous particle and an average particle diameter of 1 mm or less.

The vinyl-based monomer impregnated in the powdery propylene-based polymer in the present invention is a liquid at room temperature, contains aromatic vinyl as a main component, and contains other vinyl monomers. Is also good. Examples of the aromatic vinyl include styrene, methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, and the like, and are used alone or as a mixture. Such an aromatic vinyl monomer has an advantage of suppressing a decrease in the molecular weight of the propylene-based polymer, which is a problem in melt-kneading polymerization, and improving mechanical properties such as rigidity.

The above-mentioned vinyl monomer can be copolymerized with the aromatic vinyl in addition to the aromatic vinyl as a main component.
Other vinyl monomers, for example, various vinyl cyanides, such as acrylonitrile; various vinyl esters, such as vinyl acetate; acrylic acid or methacrylic acid or their alkyl esters or glycidyl esters; And maleic acid may be used in combination.

In particular, it is preferable to use an aromatic vinyl monomer in combination with a vinyl monomer having a functional group capable of forming a hydrogen bond in order to increase the polarity of the graft polymer and improve printability and adhesiveness. Examples of the polar functional group-containing vinyl monomer used in combination include a copolymerizable epoxy group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer, a carboxyl group-containing vinyl monomer, an oxazoline group-containing vinyl monomer, and a silanol. And a group-containing vinyl monomer. Preferably, it is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.

As the epoxy group-containing vinyl monomer, for example, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, methacryl glycidyl ether and the like can be mentioned, and these can be used alone or in combination. Glycidyl methacrylate is particularly preferred.

Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
-Hydroxybutyl methacrylate and the like can be used alone or as a mixture.

Examples of the silyl group-containing vinyl monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, vinyltris ( 2-methoxyethoxy) silane and the like may be used alone or as a mixture.

The carboxyl group-containing vinyl monomer includes, for example, acrylic acid, methacrylic acid, maleic anhydride, maleic acid and the like and their alkyl esters, and these can be used alone or as a mixture.

Examples of the oxazoline group-containing vinyl monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-oxazoline and the like.

The amount of the vinyl monomer used is 5% by weight or more based on the total weight with the powdery propylene polymer.
Preferably it is 5 to 30% by weight. The amount of aromatic vinyl in the vinyl monomer is 50% by weight or more, preferably 80% by weight.
% By weight, and most preferably 95% by weight or more. The amount of the aromatic vinyl is larger than the amount added, preferably 1 to 5 times, when other vinyl monomers are used in combination, in order to prevent the modified propylene-based polymer from having a low molecular weight. Is preferred. Incidentally, other monomers other than aromatic vinyl, lowering the molecular weight of the resulting modified propylene-based polymer,
It should be used to such an extent that adverse effects such as tackiness, hygroscopicity and mechanical properties are not increased.

The radical polymerization initiator described above is easily dissolved in aromatic vinyl because of the characteristics of the present invention, and has a half-life of one minute in order to carry out polymerization at the melting and kneading temperature of a propylene polymer. Decomposition temperature to obtain 130 ° C
The temperature is in the range of 175 to 250 ° C.

Among the radical polymerization initiators, particularly typical examples are t-butyl peroctate, dicumyl peroxide, tert-butyl perbenzoate, dimethyl-di (tert-butyl peroxy) hexane. , Bis (tert-butylperoxyisopropyl) benzene, dimethyl-di (tert-butylperoxy) hexyne, diisopropylbenzene hydroperoxide or cumene hydroperoxide.

The amount of the radical polymerization initiator used is preferably within a range of 0.1 to 10 parts by weight, particularly preferably 100 parts by weight of the vinyl monomer.
A range of 1 to 5 parts by weight is appropriate.

Furthermore, polypropylene has a radical disintegration property greatly different from that of polyethylene.
In performing the graft polymerization, it is desirable to add a so-called stabilizer. However, needless to say, it is necessary to consider the type and the amount of addition so as not to hinder the polymerization of the vinyl-based monomer.

As typical examples of this type of stabilizer, only typical ones are exemplified. Pentaerythrityl-tetrakis ((di-tert-butyl-hydroxyphenyl) propionate), octdecyl (di-tert-butyl-) Various hindered phenolic stabilizers, such as (hydroxyphenyl) propionate, thiobis (methyl t-butylphenol) or trimethyl-tris (di-tert-butylhydroxybenzyl) benzene;
Various phosphorus stabilizers, such as tetrakis (di-tert-butylphenyl) biphenylene phosphite or tris (di-tert-butylphenyl) phosphite; various metal soaps, such as zinc stearate or calcium stearate; Or various antacid adsorbents such as magnesium oxide or hydrotalcite.

The amount of the stabilizer to be used is usually 0.0 to 100 parts by weight of the powdery propylene polymer.
The range of 1 to 1 part by weight is preferably 0.05 to
A range of 0.5 parts by weight is appropriate.

Further, as an additive, a small amount of a solvent or water may be added for the purpose of diluting or degassing monomers or radical initiators.

In the present invention, the vinyl monomer and the radical polymerization initiator are substantially impregnated into the powdery propylene polymer. This impregnation is carried out at a temperature and time under which the vinyl monomer is not polymerized, and when a radical polymerization initiator is used in combination, at a temperature and time under which the decomposition does not substantially occur. Will be

The impregnation of the vinyl monomer and the radical polymerization initiator is preferably carried out so that the powdered propylene polymer impregnated with the vinyl monomer and the radical polymerization initiator have a repose angle X ゜ represented by the following formula. . A more preferable range of the angle of repose X ゜ is 35 to 60 °. (X = 12.7 + 1.62 × vinyl monomer amount + 105 × 1 / t + 567
× 1 / T) ≦ 70 ° (Amount of vinyl monomer: Numerical value of% by weight based on powdered propylene polymer t: impregnation time (minute), T: impregnation temperature (° C.))

In general, the angle of repose (spatula angle) is an index indicating the fluidity of a granular material in the powder industry, and a spatula is inserted into a sample powder so as to have a constant thickness.
Then, the spatula is pulled up and is indicated by the angle of the bottom side of the sample that has become a mountain shape (powder and industrial Vol9, No.
1, P61-72, 1977). It is usually measured at room temperature with a powder tester (manufactured by Hosokawa Micron Powder Engineering Laboratory).

The range of the angle of repose X in the present invention is obtained from an equation determined from the relationship among the amount of the vinyl monomer, the impregnation time and the impregnation temperature based on various experiments. When the angle of repose X is in the above range, the fluidity of the impregnated powdery propylene-based polymer is good, and it is also preferable from the viewpoint of supplying to the melt-kneading apparatus.

In the impregnation operation of the present invention, the impregnation temperature is preferably 100 ° C. or less, more preferably 80 to 20 ° C., and the impregnation time is preferably 5 minutes or more, and 10 to 60 minutes. Minutes are more appropriate.
In addition, the impregnation is preferably performed in a closed system using a mixer, for example, a Henschel mixer, or in an inert gas atmosphere such as nitrogen.

The vinyl-based monomer melt-kneading the powdery propylene polymer impregnated like, when polymerizing reacting the vinyl monomer is Toka various sealed containers, such as Bunbury, such as extruder It can be carried out using various continuous kneading machines capable of continuous production. In the case of so-called industrial production such as granulation as a melt kneading machine, it is preferable to use an extruder, and from the viewpoint that supply of raw materials and management of polymerization time are simple. It is more preferable to use a twin-screw extruder.

As a preferable method for producing a modified propylene polymer, a powdery propylene polymer impregnated with a vinyl monomer or the like is supplied to an extruder, and the propylene polymer is pressed under pressure.
It is preferable to use a method in which the propylene-based polymer is melted by heating to a temperature within a range of 50 to 250 ° C., the vinyl-based monomer is polymerized, and then discharged from a die.

At this time, the vinyl monomer is mixed with the propylene polymer in advance and sufficiently impregnated before being supplied to the extruder. The part may be supplied from a liquid feeder to a propylene-based polymer in a molten state.

When a radical polymerization initiator is used in combination, it is preferable to add it by dissolving it in a vinyl monomer in advance.
From the liquid-body feeder may be added to the vinyl monomer containing the propylene-based polymer in the molten state. When a stabilizer is used in combination, it is preferable to mix the stabilizer with the powdery propylene polymer in advance.

In the present invention, when a vinyl monomer normally undergoes a polymerization reaction in the presence of a radical initiator, the propylene polymer in a molten state is sufficiently brought into contact with and mixed with the vinyl monomer. In addition, a polymer (graft polymer) in which a polymer derived from a vinyl monomer is grafted on a propylene polymer may be produced. Normally, propylene-based polymers, unlike ethylene-based polymers, are radically disintegrating polymers, so if they are simply melt-heated, molecular breakage is likely to occur, but in the presence of vinyl monomers containing aromatic vinyl, etc. On the contrary, by performing the melting and heating, the graft reaction is easily caused while preventing the network from forming.

The resulting modified propylene-based polymer is composed of a propylene-based polymer component and mainly an aromatic vinyl-based polymer component, but is homogeneous and can be used as it is as a molded product or as a pellet. Can be taken out.

Thus, the modified propylene-based polymer itself is a thermoplastic resin having excellent heat resistance, rigidity, moisture-proofing properties, surface properties, and the like. Can be used for applications. further,
Since the modified propylene-based polymer is composed of polar and non-polar portions, it can be used as a compatibility improver for various polymers (polymers or resins) or as an inorganic filler (inorganic filler). ) Are also excellent as compatibility improvers.

The modified propylene polymer obtained in the present invention includes reinforcing fibers such as glass fiber, carbon fiber and Kevlar fiber, inorganic fillers such as calcium carbonate, silica, mica and aluminum hydroxide, and organic and inorganic materials. Pigments, dyes and the like can be added. These additives may be previously mixed with the powdery propylene polymer as long as the effects of the present invention are not impaired, or when the powdery propylene polymer impregnated with the vinyl polymer is melt-kneaded. May be added.

[0043]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, all parts and percentages are by weight unless otherwise specified.

(Example 1) In a Henschel mixer, "Hipole B20" having an average particle diameter of 660 microns (μm) was added.
0P "[powder polypropylene manufactured by Mitsui Petrochemical Industries, Ltd.], 880 parts," Irganox 1010 "
(Ciba-Geigy, Switzerland) 0.5 parts, Phosphite 168 (Ciba-Geigy).
5 parts and one part of calcium stearate were mixed.
120 parts of styrene mixed with 5.8 parts (0.02 mol) of "Perhexin 25B" (product of NOF Corporation) was added to the above-mentioned powdery polypropylene blend, and the mixture was heated at 50 ° C. Mix for 20 minutes.

The angle of repose X ° of the obtained composition was 48.7 ° from the above formula, and the angle of repose was measured by a powder tester to be 49 °, which was almost the same. This compound was smoothly supplied to an extruder and the like.

Next, the mixture was added to a barrel temperature of 200
C. (However, the feeder section is 180.degree. C.), and a 30 mm single-screw extruder (manufactured by Tanabe Iron Works Co., Ltd.) equipped with a quantitative feeder and the die temperature is set at 210.degree. A modified propylene polymer was obtained.

The obtained polymer was supplied to an extruder, extruded at a speed of 20 revolutions per minute, and taken out as pellets. The pellets obtained were transferred to IS5 manufactured by Toshiba Machine Co., Ltd.
Using a 0AM injection molding machine, a test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. Various physical properties of this specimen were measured and evaluated.

The above pellets were analyzed by infrared spectroscopy at 700 cm ^-1 (attributable to styrene) and 13 cm
The styrene content was measured from a calibration curve based on the ratio to 80 cm ^-1 (attributed to polypropylene), and the value was used to determine the degree of polymerization of styrene. Furthermore, in order to judge the presence or absence of polystyrene grafting, polypropylene does not dissolve, but polystyrene pellets are placed in tetrahydrofuran as a solvent that dissolves, and the mixture is subjected to Soxhlet extraction under reflux and the styrene portion in the pellets From the ratio, the graft ratio was also measured. Table 1 shows the above measurement results.

The degree of polymerization was 85% or more so that the monomer recovery treatment was not particularly required, and the degree of rigidity was 1% higher than that of the polypropylene alone (unmodified polypropylene). It is known that the target value that is to be increased by a certain percentage or more is achieved, and the rigidity is improved. Also,
Transparency is also acceptable as packaging material, 70%
The transmittance was above, and the heat-deformable one was 130 ° C. or higher, which is necessary for a container for reheating a microwave oven. The moisture permeability was almost the same as that of the polypropylene alone, and was, of course, much better than that of polystyrene.

(Comparative Example 1) Instead of using 120 parts of styrene and 5.8 parts of “Perhexin 25B” and mixing with a Henschel mixer, only the feeder section of an extruder was used, and the feeder section was used. At the same time as powdered polypropylene compound to styrene,
Mixing was attempted in the same manner as in Example 1 except that the addition (quantitative supply) of “Irganox 1010” and “Phosphite 168” was performed. However, the screw slipped in the feeder section of the extruder, and in order to prevent the compound from being bitten, the extrusion was abandoned and stopped without stopping.

Comparative Example 2 A control polypropylene was prepared in the same manner as in Example 1 except that the conditions for mixing the powdery polypropylene compound with a Henschel mixer were changed to 23 ° C. for 3 minutes. A formulation was obtained. The angle of repose X ° for this formulation is 91.8 ° from the above formula.
And it could not be measured with a powder tester.

The blend was melt-kneaded in an extruder in the same manner as in Example 1 to obtain a modified propylene polymer, which was analyzed and various physical properties were measured.
Table 1 shows the measurement results.

The polymerization rate of the obtained polymer was less than 85%, and the graft rate was also less than 20%. In addition, the transparency required for the packaging material was also less than 70%. For that reason, even with respect to rigidity, there was only a small improvement effect of less than 10% as compared with polypropylene alone.

(Examples 2 and 3) The conditions for mixing the powdery polypropylene compound with a Henschel mixer were as follows:
Except for 10 minutes at 80 ° C. and 60 minutes at 23 ° C., each formulation was obtained in the same manner as in Example 1.
Next, a modified propylene-based polymer was obtained for both blends in the same manner as in Example 1, and analyzed and measured for various physical properties. Table 1 shows the measurement results.

In each case, the angle of repose of the formulation was 49
° (49.7 ° above) and 58 ° (58.5 ° above)
And the conversion was 80% or more. The stiffness was also much improved to more than 10% of the polypropylene alone. Transparency is also acceptable as a packaging material, 70%
The transmittance was above, and in addition, the heat-deformable one was also required as a container for reheating microwave oven at 130 ° C.
That was all.

[0056]

[Table 1]

<< Footnote in Table 1 >>"PP" in the table is
It is an abbreviation of "polypropylene", and the unit of particle diameter is micron (μm).

"Styrene charge ratio" is "%" in the weight sum with polypropylene.

Further, as a method of evaluating various physical properties,
It is as follows. Angle of repose: The measurement was carried out using a powder tester (Hosokawa Micron) according to the same (degree) specification.

Thermal deformability: Measured according to JIS K-7202
In accordance with, the Vicat temperature is indicated by (° C),
The load was set at 1 kg. Rigidity ... Measurement was based on JIS K-7203.

(10 ⁴ kg / cm ² ) Transparency: A 300 μm thick sheet produced by hot pressing was measured with a haze meter (%).

(Example 4) As a powdery polypropylene compound, 800 parts of "Hypol B200P"
A mixture of 0.4 parts of "Irganox 1010", 0.4 parts of "Phosphite 168" and 0.8 parts of calcium stearate was added to 200 parts of styrene, and 9.7 of "Perhexin 25B" was added to 200 parts of styrene. Part (0.
03 mol) was added and mixed, and the conditions for mixing with a Henschel mixer were set to 70.
A target modified propylene-based polymer was obtained in the same manner as in Example 1 except that the temperature was changed to 20 ° C for 20 minutes. Analysis and measurement of various physical properties of this polymer were performed in the same manner as in Example 1. Table 2 summarizes the measurement results.

The angle of repose of the compound was 59 ° (the above expression 59.4).
゜), and the conversion was 85% or more. Further, the rigidity was improved to 10% or more of the polypropylene alone. Transparency is also acceptable as a packaging material,
It had a transmittance of 70% or more. In addition, the heat-deformable one was also required as a container for reheating a microwave oven.
° C or higher.

Example 5 A powdery polypropylene compound having an average particle diameter of 245 obtained by freeze-pulverization was used.
800 μm “Hypole B200P” (same as above)
To 0.4 parts of “Irganox 1010”, 0.4 parts of “Phosphite 168” and 0.8 parts of calcium stearate,
8. Add “Perhexin 25B” to 200 parts of styrene.
Same as Example 1 except that 7 parts (0.03 mol) were added and mixed, and the conditions for mixing with a Henschel mixer were changed to 50 ° C. for 30 minutes. Thus, the intended modified propylene-based polymer was obtained. Analysis and measurement of various physical properties of this polymer were performed in the same manner as in Example 1. Table 2 summarizes the measurement results.

The angle of repose of the compound was 59 ° (the above formula of 59.9).
゜), and the conversion was 85% or more. Further, the rigidity was improved to 10% or more of the polypropylene alone. Transparency is also acceptable as a packaging material,
It had a transmittance of 70% or more. In addition, the heat-deformable one was also required as a container for reheating a microwave oven.
° C or higher.

(Comparative Example 3) As a powdery polypropylene compound, 800 parts of "Hypol B200P" were added to 0.4 parts of "Irganox 1010", 0.4 parts of "phosphite 168" and 0.4 parts of calcium stearate. 8 parts, and 20 parts of styrene
To 9.7 parts (0.03 parts) of "perhexin 25B"
(Equivalent to mole)).
At the same time, the conditions for mixing with a Henschel mixer were set at 23 ° C.
In the same manner as in Example 1 except that the time was changed to 3 minutes, an attempt was made to supply a fixed amount of the powdery polypropylene compound to the feeder portion of the extruder. However, the screw slipped in the feeder section of the extruder, and the extrusion was stopped in order not to bite the compound.

(Example 6) As a powdery polypropylene compound, 890 parts of "Hypol B200P"
A mixture of 0.5 parts of “Irganox 1010”, 0.5 parts of “Phosphite 168” and 1 part of calcium stearate was mixed with 90 parts of styrene and 20 parts of glycidyl methacrylate to obtain “Perhexin 25”.
Example 1 except that 5.3 parts (0.02 mol) of "B" were added and mixed, and the conditions of mixing with a Henschel mixer were set to 50 ° C. for 20 minutes. Similarly, an intended extruded product, that is, a modified propylene-based polymer was obtained. Analysis and measurement of various physical properties of this polymer were performed in the same manner as in Example 1. Table 2 summarizes the measurement results.

The angle of repose of the blend was 47 ° (the formula 47.1).
゜), and the conversion was 85% or more. Further, the rigidity was improved to 10% or more of the polypropylene alone. Transparency is also acceptable as a packaging material,
It had a transmittance of 70% or more. In addition, the heat-deformable one was also required as a container for reheating a microwave oven.
° C or higher.

(Comparative Example 4) The same as Example 1 except that the sole polypropylene "Hypol B200" [manufactured by Mitsui Petrochemical Industry Co., Ltd.] was used instead of the powdery polypropylene compound. Then, a test piece was prepared. This test piece was also analyzed and measured for various physical properties in the same manner as in Example 1. Table 2 summarizes the measurement results.

Although the transparency and the thermal deformability of the molded product were good, the rigidity was much lower.

[0071]

[Table 2]

[0072]

According to the present invention, a powdery propylene polymer is substantially impregnated with a vinyl monomer mainly composed of aromatic vinyl, and then kneaded and melted to polymerize the vinyl monomer. By doing so, the resulting modified propylene-based polymer has good mechanical strength and moldability, etc., and is particularly excellent in transparency, rigidity, moisture-proofness, etc., and is extremely useful as a material for packaging containers. Can be provided.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-155413 (JP, A) JP-A-49-112945 (JP, A) JP-A-56-41213 (JP, A) JP-A 50-112 156542 (JP, A)

Claims (4)

(57) [Claims] (1) a powdery propylene polymer and (b) a vinyl monomer containing an aromatic vinyl monomer as a main component in an amount of 5% by weight or more (based on the total weight of the propylene polymer and the propylene polymer); )
After adding, the polymer (a) is substantially impregnated with the vinyl monomer (b), and then homogeneously melt-kneaded to obtain the vinyl monomer (b).
A method for producing a modified propylene-based polymer, comprising subjecting a modified propylene-based polymer to a polymerization reaction. 2. The modified propylene polymer according to claim 1, wherein the vinyl monomer (b) comprises aromatic vinyl and the same amount or less of another vinyl monomer. Manufacturing method. 3. A powdery propylene-based polymer, (b)
Vinyl monomer containing aromatic vinyl monomer as a main component 5
% By weight (based on the total weight with the propylene-based polymer) and (c) a radical polymerization initiator, and the polymer is substantially impregnated with a vinyl-based monomer and a radical polymerization initiator. A method for producing a modified propylene-based polymer, comprising homogeneously melt-kneading and polymerizing a vinyl-based monomer. 4. A repose of a vinyl monomer (b) containing an aromatic vinyl monomer as a main component or a powdery propylene polymer (a) impregnated with the vinyl monomer and a radical polymerization initiator. When the angle X is (X = 12.7 + 1.62 × amount of phenyl-based monomer + 105 × 1 / t + 567 × 1 / T) ≦ 70 ° (amount of vinyl-based monomer:% by weight based on powdery propylene-based polymer) The mixture is mixed so as to obtain a numerical value t: impregnation time (minute), T: impregnation temperature (° C.), and then homogeneously melt-kneaded to polymerize the vinyl monomer (b). 1 to
3. The method for producing a modified propylene-based polymer according to any one of 3.