JPH08109227A - Production of modified propylene polymer and modified propylene polymer composition - Google Patents

Abstract

PURPOSE: To obtain a modified propylene polymer excellent in transparency, mechanical strengths (rigidity) and extrudability by using a specified extruder having a specified ratio of the length of the screw to the bore diameter. CONSTITUTION: A process for producing a modified propylene polymer by polymerizing a vinyl monomer by kneading a propylene polymer and the vinyl monomer at a temperature higher than the kneading temperature, which comprises premixing the propylene polymer with the vinyl monomer and using a corotating twin-screw extruder having a ratio of the length of the screw to the bore diameter of 30 or above. It is preferable that the extruder is one which can provide a residence time of 1min or longer. It is desirable that the propylene polymer used is a powdery one having a specific surface area of 0.1m<2> /g or above. It is desirable that the vinyl monomer predominantly consists of an aromatic vinyl monomer. In the premixing, a free-radical polymerization initiator is optionally used. The amount of the vinyl monomer used is desirably 5wt.% or above.

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-based polymer which is capable of increasing the amount of modification with a vinyl monomer and is excellent in transparency, rigidity and extrusion moldability, and particularly in food packaging, It is intended to provide a modified propylene-based polymer composition which is useful as a material for containers and the like and is excellent in rigidity, transparency and moisture permeability.

[0002]

2. Description of the Related Art Polypropylene is low in cost and excellent in mechanical strength, heat resistance, oil resistance, electric characteristics, etc.
Widely used for various purposes such as films, fibers, and molded products.

However, polypropylene is
It is inferior to other vinyl polymers, especially polystyrene, in terms of sheet processability and surface characteristics. For example, in the field of packaging containers, polypropylene has a lower rigidity than polystyrene and has a drawback that sheet processing is difficult. However, on the other hand, it has advantages such as superior heat resistance, oil resistance, and moisture resistance to polystyrene. Therefore, if a molding material having a good balance between the advantages of polypropylene and the advantages of polystyrene can be made, it is expected that it will be possible to use it in the fields of application that were previously unusable.

Therefore, it has been attempted to blend polypropylene with polypropylene or polymerize styrene in the presence of a propylene polymer. JP-A-59-217
Japanese Patent No. 742 discloses a modified polypropylene obtained by polymerizing a styrene monomer in an aqueous suspension system in the presence of a propylene polymer. Further, in JP-A-4-213313, a modified polypropylene obtained by activating a granular propylene-based polymer with a peroxide and then 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.

However, since polypropylene and polystyrene are incompatible with each other and the interfacial adhesion between the two resins is poor if they are simply blended, the polystyrene part is insufficiently dispersed and phase separation occurs, resulting in a molded product. Mechanical properties such as transparency, rigidity, and impact resistance are unsatisfactory and are not practical. When the styrene monomer is polymerized in an aqueous suspension system or solid phase system in the presence of a granular propylene polymer, the steps such as blocking prevention, polymerization temperature control, and product drying are complicated. Then, there was a problem in industrialization as a general-purpose polymer.

As described above, the introduction of the styrene-based polymer into the propylene-based polymer by the conventional method has the following effects on the polymer performance.
Or it was not satisfactory in manufacturing. This is due to the insufficient dispersion of polystyrene in the propylene polymer. And in order to sufficiently disperse polystyrene, the presence of a graft polymer of a propylene-based polymer and polystyrene is desirable, but polypropylene is
In the first place, since it is a highly crystalline material, first, it has a high melting point, and then it does not dissolve in the styrene-based monomer.
It is thought that this is because it is difficult to form a graft polymer.

[0007]

However, the object of the present invention is to solve various drawbacks in the prior art, and in particular, it is excellent in transparency, mechanical strength (rigidity) and extrusion molding processability, and is extremely practical. It is intended to provide a method for producing a modified propylene polymer and a composition.

[0008] Therefore, the present inventors have focused on the problems to be solved by the invention as described above in order to solve the drawbacks in the conventional method as described above, that is, the transparency, the mechanical strength and the moldability. As a result of repeated intensive research, various properties were previously obtained by polymerizing the aromatic vinyl monomer in the presence of a propylene polymer in a molten state in an extruder or the like. We have filed an application, finding that an excellent graft polymer can be obtained. (JP-A-4-359910, JP-A-5-155947)
(Japanese Patent Laid-Open No. 5-239158)

However, as a result of further investigation, as a method for carrying out melt-kneading polymerization in these extruders, when the extruder is a single-screw extruder, a propylene-based polymer mixture prepared by premixing a liquid vinyl monomer is preliminarily mixed. When feeding to the extruder, the screw slips and it is difficult to bite into the extruder,
It was found that the dispersion particle size of the graft polymer component in polypropylene becomes large and the physical properties such as transparency are inferior because the mixing and dispersing power is insufficient.

Further, not only when the extruder is a different-direction twin-screw extruder, but also in the same-direction twin-screw extruder, if the residence time is less than 1 minute, the polymerization reaction time is short and the vinyl monomer is short. The reaction rate is low, the modified propylene polymer becomes non-uniform and the transparency is insufficient, and it is not possible to increase the vinyl polymer content in the modified propylene polymer to increase the rigidity. It was

Further, even if the same-direction type twin-screw extruder is used, the propylene polymer is supplied and the polymer is melted, and then the vinyl monomer is injected into the molten polymer from the middle of the extruder by a liquid injection pump to melt-knead. In the case of the polymerization method, it was found that the modified propylene-based polymer obtained had insufficient compatibility and poor transparency, and fish eyes were likely to occur.

The present invention is a method for producing a modified propylene-based polymer having excellent transparency and rigidity, which is excellent in extrusion moldability, and is particularly excellent in rigidity, transparency and moisture permeability, which is useful as a material for food packaging, containers and the like. A propylene-based polymer composition is intended.

[0013]

Means for Solving the Problems As a result of detailed research, the inventors of the present invention preliminarily mixed a propylene-based polymer and a vinyl-based monomer when producing the modified propylene-based polymer, The ratio of the screw length (L) to the bore diameter (D) is 30.
By using the same-direction twin-screw extruder that is the above, by melt-kneading polymerization reaction of the propylene-based polymer and the vinyl-based monomer mixture, the polymer conversion rate and graft rate of the vinyl monomer is high, and the transparency is high. The inventors have found that the excellent balance of physical properties with excellent rigidity and extrudability is excellent, and have completed the present invention.

That is, the present invention is a method for producing a modified propylene-based polymer in which a vinyl-based monomer is polymerized by kneading at a melting temperature or higher to premix the propylene-based polymer and the vinyl-based monomer. However, a method for producing a modified propylene-based polymer, preferably a screw, which uses a co-directional twin-screw extruder having a ratio of the length (L) of the screw to the diameter (D) of 30 or more. Length (L) and diameter (D)
Is 40 to 70, preferably, the mixture is used in the same direction twin-screw extruder having a residence time of 1 minute or more, preferably a residence time of 3 minutes to 10 minutes, preferably Is a unidirectional twin-screw extruder, preferably a vinyl-based monomer containing aromatic vinyl as a main component, and if necessary radical-polymerized with respect to a granular propylene-based polymer having a specific surface area of 0.1 m ² / g or more. A method for producing a modified propylene-based polymer, which comprises adding an initiator and premixing the mixture, and (a) using a co-directional twin-screw extruder having a residence time of 1 minute or more, (b) Granular propylene-based polymer having a specific surface area of 0.1 m ² / g or more, (c) vinyl-based monomer containing an aromatic vinyl monomer as a main component 5% by weight or more (with the propylene-based polymer). (In total weight) and (d) radical polymerization initiator are mixed and A modified propylene polymer composition obtained by substantially impregnating a body with a vinyl monomer and a radical polymerization initiator, and then melt-kneading the mixture to polymerize the vinyl monomer. Provide things.

(Structure) FIG. 1 is a schematic view of a co-directional twin-screw extruder used in carrying out the present invention. The same-direction twin-screw extruder is an extruder in which the ratio of the screw length (L) to the bore diameter (D) is 30 or more, preferably 35 or more, more preferably 40 to 70, and Has a residence time of 1 minute or more, more preferably 3 minutes to 10
Minutes.

The same-direction type twin-screw extruder has a metering feeder 1, a liquid injection pump 3, a vacuum line 4, a motor 5, a gear box 6, cylinders C1 to C12, as shown in FIG.
It consists of a die D and the screw is a segment system. Further, by providing the screw with a kneading disk portion or a reverse flight portion, the mixing and dispersing ability can be improved and the residence time can be further lengthened.

The same-direction twin-screw extruder has more stable feed capability and longer residence time than the single-screw extruder and different-direction twin-screw extruder. It is suitable for the production of the modified propylene-based polymer of the present invention because it has a good turning-back effect, good surface renewal property, and excellent volatilization performance and self-cleaning property. The same-direction twin-screw extruder has a screw diameter (D) of 20 mm to 400 mm, but those having an L / D of less than 30 have a shorter residence time and thus have a vinyl monomer reaction rate. Is low, an inhomogeneous modified propylene polymer having low transparency is produced, and the extrusion amount becomes unstable, so that the extrusion moldability is deteriorated, which is not preferable.

There are two-thread type and three-thread type screw, and the meshing of the two screws can be a complete meshing type and a partial or non-meshing type. Any of them can be used.

The vacuum line 4 is used for removing unreacted monomers and the like.

The vinyl monomer used in the present invention is required to be mixed and pre-mixed before the propylene polymer is melted in order to obtain a homogeneous modified propylene polymer having excellent compatibility. Yes, the pre-mixture is fed through the metering feeder from the feed port farthest from the exit of the extruder, or only the propylene-based polymer is charged through the metering feeder, and the vinyl monomer is the unmelted propylene-based polymer. It can be pumped from the 3rd supply port.

In the extruder of the present invention, as an auxiliary equipment, a metering feeder for quantitatively supplying raw materials to the extruder, a liquid injection pump for adding a post-addition vinyl monomer and an azeotropic agent, an inert gas. Inert gas supply device for carrying out kneading polymerization in an atmosphere, vent port and vacuum pump for removing residual monomers and decomposition by-products after polymerization, for cooling and pelletizing the modified propylene polymer The water tank and the cutter, or a pelletizer in which they are integrated, etc. are required, and a viscosity measurement or composition analyzer for quality control may be installed.

The melt-kneading temperature in the extruder is preferably 1
It is performed at 70 to 230 ° C.

The powdery and granular propylene-based polymer used in the present invention is a homopolymer of propylene and a copolymer containing propylene as a main component with other olefins or ethylenically unsaturated monomers (both are , Which is a copolymer comprising propylene in an amount of 75% by weight or more.), Which may be polymerized by any catalyst system such as Ziegler-Natta catalyst or Kaminsky catalyst.
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. It is also possible to use a mixture of two or more of these propylene-based polymers. If the crystallinity of the propylene-based polymer is low or the copolymerization ratio is high, the propylene-based polymer is easily dissolved in the vinyl monomer, the preliminary mixture becomes sticky and lumpy, and it is difficult to supply it to an extruder or the like, which is not preferable.

The propylene-based polymer is powdery,
The particles are fine, and the particle size is preferably 50 to 1000.
When μ is large and the particle size is large, it is desirable to be porous. Further, it does not dissolve in the vinyl monomer and has a large specific surface area for adsorbing them, and preferably has a specific surface area of 0.
It is 1 m ² / g or more, more preferably 0.2 m ² / g or more. If the specific surface area is less than 0.1 m ² / g, the modified propylene polymer tends to become non-uniform, resulting in poor transparency and rigidity, which is not preferable. A powdery granular propylene-based polymer having a large specific surface area is produced by a polypropylene manufacturer such as Idemitsu Petrochemical. As a propylene-based polymer having a particularly large specific surface area, for example, Acurel PP manufactured by AKZO (Netherlands) or HIMONT's (Italy) spheripol PP etc. are mentioned.

Further, in the present invention, other powdery polymers may be used within a range that does not impair the properties of the powdery and granular propylene-based polymer. However, since a radically crosslinkable powdery polymer such as polyethylene causes an increase in kneading torque due to reticulation during melt-kneading, it is preferably half or less than the raw material polypropylene.

The vinyl-based monomer to be impregnated in the powdery or granular propylene-based polymer in the present invention is a liquid at room temperature, contains an aromatic vinyl monomer as a main component, and contains another vinyl monomer. You may have. Examples of the aromatic vinyl monomer include styrene, methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene, and bromostyrene, which may be used alone or in combination. 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 during melt-kneading polymerization, and improving mechanical properties such as rigidity.

In addition to the aromatic vinyl monomer as the main component, other vinyl monomers copolymerizable with the aromatic vinyl monomer, such as acrylonitrile, can be used as the vinyl monomer. Vinyl cyanide; various vinyl esters such as vinyl acetate; acrylic acid or methacrylic acid or their alkyl esters or glycidyl esters, and further maleic acid may be used in combination.

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

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

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

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

The vinyl monomer containing an oxazoline group includes 2-vinyl-2-oxazoline and 2-vinyl-4-.
There are methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-oxazoline and the like.

The amount of the vinyl-based monomer used is 5% by weight or more in the total weight with the powdery propylene-based polymer,
It is preferably 5 to 50% by weight. The amount of aromatic vinyl in the vinyl monomer is 50% by weight or more, preferably 80% by weight.
It is more than weight%. The amount of the aromatic vinyl monomer is larger than the addition amount when other vinyl monomers are used in combination, preferably 1 to 5 times, in order to prevent the modified propylene polymer from having a low molecular weight. Is preferred. It should be noted that monomers other than aromatic vinyl should be used to the extent that the resulting modified propylene-based polymer does not have a large adverse effect on the molecular weight reduction, tackiness, hygroscopicity, mechanical properties and the like.

As the above-mentioned radical polymerization initiator, due to the features of the present invention, it is easily dissolved in aromatic vinyl, and since the polymerization is carried out at the melt-kneading temperature of the propylene-based polymer, the half-life of 1 minute. The decomposition temperature to obtain
It is above, and preferably 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 and 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 in the range of 0.1 to 10 parts by weight, and particularly preferably, with respect to 100 parts by weight of the vinyl monomer.
A range of 1 to 5 parts by weight is suitable.

Further, since polypropylene has a radical disintegration property greatly different from that of polyethylene,
In carrying out graft polymerization, it is desirable to add a so-called stabilizer. However, it goes without saying that it is necessary to consider the kind and addition amount so as not to interfere with the polymerization of the vinyl-based monomer in use.

Only particularly representative examples of this type of stabilizer are listed: pentaerythrityl-tetrakis ((di-tert-butyl-hydroxyphenyl) propionate), ocdecyl (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 metallic soaps such as zinc stearate or calcium stearate; Alternatively, there are various antacid adsorbents such as magnesium oxide or hydrotalcite.

The amount of the stabilizer used is usually 0.0 with respect to 100 parts by weight of the powdery propylene polymer.
Within the range of 1 to 1 part by weight, preferably 0.05 to
A range of 0.5 parts by weight is suitable.

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

In the present invention, the vinyl monomer and the radical polymerization initiator are substantially impregnated in the powdery propylene polymer. This impregnation is carried out under the conditions of temperature and time at which the vinyl monomer does not polymerize, and when the radical polymerization initiator is used in combination, the impregnation is carried out under the conditions of temperature and time so that the decomposition thereof does not substantially occur. Need to be
Therefore, it is necessary to add the vinyl monomer before the supply port farthest from the exit of the same-direction twin-screw extruder or the propylene-based polymer is melted.

The premixing of the vinyl monomer with the propylene polymer in the present invention is carried out at a mixing temperature of 100 ° C. or lower, preferably in the range of 80 to 20 ° C. to prevent volatilization of the vinyl monomer. For the purpose of stirring, the range of 50 to 20 ° C. is more suitable, and the mixing time is preferably 5 minutes or more, more preferably 10 to 60 minutes. In addition, during such premixing, it is preferable to perform mixing in a closed system using a mixer, such as a Henschel mixer, or in a conveying zone before the compression zone where the propylene polymer is unmelted in the extruder. It is preferable to premix them in an atmosphere of an inert gas such as nitrogen.

In the present invention, when a vinyl monomer is usually polymerized in the presence of a radical initiator, the propylene polymer in a molten state is sufficiently contacted with the vinyl monomer to be mixed. A polymer (graft polymer) in which a polymer derived from a vinyl monomer is grafted onto a propylene polymer may be produced. Unlike ethylene-based polymers, propylene-based polymers are usually radical-disintegrating polymers. Therefore, if they are simply melt-heated, molecular cleavage tends to occur, but in the presence of vinyl-based monomers containing aromatic vinyl, etc. On the contrary, by carrying out the melting and heating with, the graft reaction is likely to occur while preventing reticulation.

The obtained modified propylene-based polymer, which is composed of a propylene-based polymer component and an aromatic vinyl-based polymer component, is homogeneous and, as it is, as a molded article or pellet. Can be taken out as.

Thus, the modified propylene-based polymer itself is a thermoplastic resin having excellent heat resistance, rigidity, moisture resistance and surface property, and therefore, it can be used for food packaging, containers, various housings, etc. It can be used for various purposes. further,
Since the modified propylene-based polymer is composed of polar and non-polar parts, it can be used as a compatibility improver of various polymers (polymers or resins) or with an inorganic filler (inorganic filler). It is also excellent as a compatibility improver with other agents.

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, organic / inorganic. Pigments, dyes, etc. can be added. These additives may be mixed in advance with the powdery propylene-based polymer as long as the effects of the present invention are not impaired, and when the powdery propylene-based polymer impregnated with the vinyl-based polymer is melt-kneaded. May be added to.

[0048]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, all parts and% are by weight unless otherwise specified.

(Example 1) In a 75 liter Henschel mixer, "Idemitsu Polypropylene" having a specific surface area of 0.24 m ² / g was obtained.
E-100G "[powder granulated polypropylene manufactured by Idemitsu Petrochemical Co., Ltd.] 10,000 parts," Irganox 101 "
0 "(stabilizer made by Ciba-Geigy, Switzerland)
10 parts of "Phosphite 168" (stabilizer manufactured by Ciba Geigy) and 5 parts of calcium stearate were weighed and mixed for 2 minutes at room temperature. This is "PP with stabilizer
-1 ". 1000 parts of styrene with "Perhexin
25B ”[polymerization initiator manufactured by NOF CORPORATION] was mixed with 10 parts of the powdered“ stabilizer blended PP-1 ”.
Add to 9000 parts and add 4 to the above Henschel mixer.
The mixture was impregnated at 0 ° C. for 30 minutes.

Next, with a screw diameter of 44 mm, L / D
No. 42 (consisting of 12 blocks, each block can be provided with a supply port) A constant-direction twin-screw extruder (TEX44XCT manufactured by Japan Steel Works, Ltd.) with a cylinder temperature of 180 ° C. Part 1
60 ° C.) and the die temperature was set to 200 ° C., the mixture was fed to the extruder at a rate of 2000 parts per hour, and melt-kneaded at a speed of 150 rpm to polymerize styrene. Then, the modified propylene-based polymer was obtained and taken out as pellets. The extruded strand had a smooth surface, was transparent, and had no pulsation. The residence time in the extruder was 3 minutes and 15 seconds. Using the IS50AM injection molding machine manufactured by Toshiba Machine Co., Ltd., the obtained pellets were used to prepare test pieces (test pieces) under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

Further, the above pellets were analyzed by infrared spectroscopic analysis to obtain 700 cm ^-1 (attributable to styrene) and 13
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 polymerization rate of styrene. Furthermore, in order to judge the presence or absence of polystyrene graft, polypropylene is not dissolved, but polystyrene is dissolved in tetrahydrofuran as a solvent, pellets are placed, and Soxhlet extraction is performed under reflux to remove residual styrene moieties in the pellets. The graft rate was also measured from the rate. The above measurement results are shown in Table 1.

The polymerization rate was 95% or more so that the monomer recovery treatment was not particularly required, and the rigidity rate was 20 more than that of the single polypropylene (unmodified polypropylene). It is known that the target value to be increased by more than 100% was achieved and the rigidity was improved. In addition, transparency is also acceptable as a packaging material.
The transmittance was 5% or more, and the heat deformability was 130 ° C. or more, which is required for a microwave oven reheating container. The moisture permeability was almost the same as that of the single polypropylene and, of course, far better than that of polystyrene.

(Comparative Example 1) In Example 1, the screw diameter was replaced by the same-direction twin-screw extruder (TEX44XCT manufactured by Japan Steel Works, Ltd.) with a constant-volume feeder having a screw diameter of 44 mm and an L / D of 42. Is 44 mm, but L /
Modified propylene system by melt-kneading and polymerizing styrene in exactly the same manner as in Example 1 except that the same-direction twin-screw extruder (TEX44XCT manufactured by Japan Steel Works, Ltd.) with a quantitative feeder having D = 21 was used. The polymer was removed as pellets. The residence time in the extruder was 45 seconds. Using the obtained pellets, an injection molding machine was used in the same manner as in Example 1 to prepare a test piece (test piece) under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

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.
The measurement results are shown in Table 1.

The polymerization rate of the obtained polymer is less than 90%,
The graft ratio was also less than 20%. In addition, the transparency required for the packaging material was also less than 65%. Perhaps because of this, the blown film had more fish eyes than the ones of Examples 1 to 5, and even if it has rigidity,
Compared to the single polypropylene, it had only a 10% or less improvement effect.

(Comparative Example 2) In Example 1, the screw diameter was replaced by the same-direction twin-screw extruder (TEX44XCT manufactured by Japan Steel Works, Ltd.) with a constant diameter feeder having a screw diameter of 44 mm and an L / D of 42. Is 30 mm and L / D
No. 28 was used, and a compound was supplied from the feeder section of the extruder in the same manner as in Example 1 except that a melt-kneading polymerization was performed. Because the screw did not slip into the propylene-based polymer blend in the feeder part, probably because it contained, the melt mixing was abandoned and stopped without stopping.

(Comparative Example 3) 9000 parts of "stabilizer blended PP-1" containing no styrene used in Example 1 were set under the same temperature conditions as in Example 1 and the screw diameter was 44.
It is supplied to a same-direction twin-screw extruder (TEX44XCT manufactured by Japan Steel Works, Ltd.) with a constant-volume feeder having a L / D of 42 in mm at a speed of 18,000 parts per hour by a constant-volume feeder, and melt-kneaded at a speed of 150 rotations. Meanwhile, styrene mixed with 1% of "Perhexin 25B" [product of NOF CORPORATION] was injected into the molten propylene-based polymer from the sixth supply port from the exit of the extruder. At a rate of 200 parts per hour. Melt kneading was carried out in the same manner as in Example 1 to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The extruded strand was inferior in surface smoothness and was whitish and translucent. Using the obtained pellets, an injection molding machine was used in the same manner as in Example 1 to prepare a test piece (test piece) under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

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.
The measurement results are shown in Table 1.

The polymer obtained had a degree of polymerization of less than 90% and a degree of grafting of less than 20%. In addition, the transparency required for the packaging material was also less than 65%.
Probably because of this, the blown film was prepared in Examples 1-5
There were more fish eyes compared to the above, and even if it is rigid, it is less than 10% compared to single polypropylene,
There was only a slight improvement effect.

(Comparative Example 4) Instead of 9000 parts of "Stabilizer blended PP-1" used in Example 1, "Tokuyama Polypro MS230" having a specific surface area of less than 0.01 m ² / g [manufactured by Tokuyama Soda Co., Ltd., Pelletized polypropylene] was mixed in the same manner as in Example 1 except that the same amount was used.
25B "[Nippon Oil & Fats Co., Ltd. product] mixed with 30 parts was added to the above pelletized polypropylene compound, and it was tried to mix at 40 ° C for 30 minutes. Since it did not absorb, styrene and the like began to separate and begin to be washed away, so the mixing was abandoned and stopped.

(Example 2) 9000 parts of "Stabilizer blended PP-1" and 1000 parts of styrene used in Example 1 were used instead of 30 parts of "Perhexin 25B" (polymerization initiator manufactured by NOF Corporation). "Stabilizer blended PP-1" 800
"Perhexin 25B" on 0 part and styrene 2000 parts
Melt kneading was carried out in the same manner as in Example 1 except that 30 parts of [polymerization initiator manufactured by NOF CORPORATION] was used to polymerize styrene, and the modified propylene polymer was taken out as pellets. Using the obtained pellets, an injection molding machine was used in the same manner as in Example 1 to prepare a test piece (test piece) under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

Then, with respect to the blend, modified propylene polymers were obtained in the same manner as in Example 1 and analyzed and measured for various physical properties. The measurement results are summarized in Table 1.

The modified propylene polymer obtained had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

Example 3 Instead of preliminarily mixing 30 parts of "Perhexin 25B" (polymerization initiator manufactured by NOF CORPORATION) with 9000 parts of "PP-1 containing stabilizer" and 1000 parts of styrene in Example 1. In the same-direction twin-screw extruder (TEX) with a constant-volume feeder having a screw diameter of 44 mm and an L / D of 42 set under the same temperature conditions as in Example 1.
44XCT manufactured by Japan Steel Works, Ltd.) at a speed of 18,000 parts per hour by a quantitative feeder, and while melt-kneading at a speed of 150 rotations, mix 3% of "Perhexin 25B" [product of NOF CORPORATION]. Styrene was injected by a liquid injection pump at a rate of 2000 parts per hour from the second supply port from the farthest from the extruder outlet. Melt kneading was carried out in the same manner as in Example 1 to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The obtained pellets were treated with an injection molding machine in the same manner as in Example 1,
A test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

The compound 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.
The measurement results are shown in Table 2.

The modified propylene polymer obtained had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

Example 4 Instead of 9000 parts of "Stabilizer blended PP-1" and 1000 parts of styrene used in Example 1, 9000 parts of "Stabilizer blended PP-1", 700 parts of styrene and 300 parts of glycidyl methacrylate. Melt kneading was carried out in the same manner as in Example 1 except that was used to polymerize styrene, and the modified propylene polymer was taken out as pellets. Using the obtained pellets, an injection molding machine was used in the same manner as in Example 1 to prepare a test piece (test piece) under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

Then, a modified propylene polymer was obtained in the same manner as in Example 1 with respect to the compound, and the modified propylene polymer was analyzed and various physical properties were measured. The measurement results are shown together in Table 2.

The obtained modified propylene polymer had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

(Embodiment 5) A 75 liter Henschel mixer having a specific surface area of 0.20 m ² / g "HYPOL J34"
0P "[powdered-granular block polypropylene manufactured by Mitsui Petrochemical Co., Ltd.], 10000 parts," Irganox 101
0 "(stabilizer made by Ciba-Geigy, Switzerland)
10 parts of "Phosphite 168" (stabilizer manufactured by Ciba Geigy) and 5 parts of calcium stearate were weighed and mixed for 2 minutes at room temperature. This is "PP with stabilizer
-2 ". In Example 1, "PP-
1 "9000 parts and styrene 1000 parts and" Perhexin 25B "[polymerization initiator manufactured by NOF CORPORATION] 10 parts instead of" Stabilizer blended PP-1 "9400 parts, styrene 500 parts and maleic anhydride 100 parts and Except for using 18 parts of "Perhexin 25B" [polymerization initiator manufactured by NOF CORPORATION], styrene was polymerized by melt-kneading in the same manner as in Example 1 to take out the modified propylene polymer as pellets. . The extruded strand had a low melt viscosity and was difficult to be fused and pelletized. The obtained pellets were heated to a resin temperature of 230 by using an injection molding machine in the same manner as in Example 1.
A test piece (test piece) was prepared under the condition of ° C. Various physical properties of this test piece were measured and evaluated.

Then, with respect to the blend, modified propylene polymers were obtained in the same manner as in Example 1 and analyzed and measured for various physical properties. The measurement results are shown together in Table 2.

The obtained modified propylene polymer had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. Was

(Comparative Example 5) In the production of the modified propylene polymer in Example 4, 9000 parts of "Stabilizer blended PP-1" and 300 parts of glycidyl methacrylate were used as they were except that 700 parts of styrene was not added, and Perhexin 25B was used. Example 1 except 18 parts (manufactured by Nippon Oil & Fats Co., Ltd.)
Melt kneading and kneading and melt polymerization were carried out in exactly the same manner as above, and the modified propylene polymer was taken out as pellets. The obtained pellets were treated with an injection molding machine in the same manner as in Example 1,
A test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. Various physical properties of this test piece were measured and evaluated.

Then, with respect to the blend, modified propylene-based polymers were obtained in the same manner as in Example 1, and the analysis and the measurement of various physical properties of them were carried out. The measurement results are shown together in Table 2.

The modified propylene polymer obtained had a polymerization rate of 90% or less. Rigidity was also 10% or more lower than that of polypropylene alone. The transparency was 65% or more, which was acceptable as a packaging material.
The thermal deformability was also 130 ° C. or lower, which is required for a microwave oven reheating container.

[0076]

[Table 1]

[0077]

[Table 2] << Footnote in Table 1 >> In the table, "PP" is an abbreviation for "polypropylene" and "S" is an abbreviation for "styrene".

The "S charge ratio" is "%" in the weight sum of styrene and polypropylene.

Further, as a method for evaluating various physical properties,
It is as follows. Specific surface area: The measurement was performed using a monosorb (surface area measuring device: Yuasa Ionics Inc.).

Thermal Deformability: Measured according to JIS K-720
In conformity with No. 2, the Vicat temperature (° C.) was displayed, and the load was 1 kg. Rigidity ... The measurement was performed according to JIS K-7203, and it was displayed in (10 ⁴ kg / cm ² ).

Transparency: 300 produced by hot pressing
A μm-thick sheet was measured with a haze meter and expressed as (%). Extrudability: The degree of trouble in the extruder was evaluated.

◯: No problem, Δ: Some problem, ×: Problem

[0083]

The production method of the present invention is a method for producing a modified propylene-based polymer in which a vinyl-based monomer is polymerized by kneading at a melting temperature or higher to obtain a propylene-based polymer and a vinyl-based monomer. The amount of modification with vinyl monomer can be increased by pre-mixing and using a co-directional twin-screw extruder having a ratio of screw length (L) to bore diameter (D) of 30 or more. Moreover, the reaction extrusion moldability in an extruder or the like is excellent, and the modified propylene polymer obtained is also excellent in compatibility. Therefore, it is particularly excellent in transparency, rigidity and moisture resistance, which is extremely practical. It is possible to provide a thermoplastic molding material that is useful as a material for packaging containers having high properties.

[0084]

[Brief description of drawings]

FIG. 1 is a cross-sectional flow sheet of a twin-screw extruder used in the present invention (L / D = 42, a cylinder is composed of 12 blocks, but a screw is not shown in cross section).

[0000]

[Explanation of symbols]

 1: Metering feeder, 2, 3: Liquid injection pump, 4: Vacuum line, 5: Motor (M) 6: Gear box (GB), C1 to C12: Cylinder block, D: Die

Claims (9)

[Claims] 1. A method for producing a modified propylene-based polymer, which comprises kneading at a melting temperature or higher to polymerize a vinyl-based monomer, wherein a propylene-based polymer and a vinyl-based monomer are premixed, The ratio of length (L) and diameter (D) is 3
A method for producing a modified propylene-based polymer, which comprises using a same-direction twin-screw extruder having a number of 0 or more. 2. The modified propylene-based polymer according to claim 1, wherein the twin-screw extruder of the same direction has a ratio of a screw length (L) to a bore diameter (D) of 40 to 70. Manufacturing method. 3. The residence time in the same-direction twin-screw extruder is 1
The method for producing a modified propylene-based polymer according to claim 1, wherein the amount is at least minutes. 4. The method for producing a modified propylene-based polymer according to claim 1, wherein the residence time is 3 minutes to 10 minutes. 5. The propylene-based polymer has a specific surface area of 0.1 m.
^A method for producing a modified propylene-based polymer, which is a powdery or granular propylene-based polymer of ² / g or more. 6. The propylene-based polymer has a specific surface area of 0.2 m.
^The method for producing a modified propylene-based polymer according to claim 1, which is a powdery or granular propylene-based polymer of ² / g or more. 7. The method for producing a modified propylene polymer according to claim 1, wherein the vinyl monomer is an aromatic vinyl monomer. 8. The modified propylene-based polymer according to claim 1, wherein the vinyl-based monomer comprises an aromatic vinyl monomer and another vinyl monomer in an amount equal to or less than that of the aromatic vinyl monomer. Manufacturing method. 9. (a) Using a twin-screw extruder of the same direction in which the ratio of the length (L) of the screw to the diameter (D) is 30 or more, (b) the specific surface area is 0.1 m ² / Granular propylene-based polymer of g or more, (c) vinyl-based monomer containing aromatic vinyl monomer as a main component 5% by weight or more (in total weight with the propylene-based polymer), and (d) It is obtained by mixing a radical polymerization initiator and substantially impregnating the polymer with a vinyl-based monomer and a radical polymerization initiator, and then melt-kneading to polymerize the vinyl-based monomer. A characteristic modified propylene polymer composition.