JP5548495B2 - Method for producing polypropylene modified resin, polypropylene modified resin - Google Patents

Description

  The present invention relates to a method for producing a polypropylene-based modified resin in which a polypropylene-based modified resin having a higher melt tension than that of the polypropylene-based resin is produced by modifying the polypropylene-based resin, and a polypropylene-based modified resin.

Conventionally, polypropylene resins have been used as raw materials for various molded products because of their excellent mechanical properties and chemical resistance.
In the case of producing a molded product using this polypropylene resin, extrusion molding, blow molding, foam molding, etc. are generally performed. However, since polypropylene resin generally has crystallinity. In some cases, the viscosity and melt tension at the time of melting are low, and a molded product having a desired property cannot be obtained even if highly accurate conditions are set when performing the molding as described above.
For example, when extrusion foaming is performed to produce a foam molded product, foam breakage due to insufficient tension of the cell membrane occurs during extrusion foaming, making it difficult to obtain a foam molded product having a dense foamed state. It has become.

In order to solve such problems, attempts have been made to improve the melt characteristics by modifying polypropylene resins.
For example, in Patent Document 1 below, a polypropylene resin is subjected to radiation cross-linking in a gas atmosphere adjusted to a specific oxygen concentration, so that the viscosity and tension at the time of melting are higher than those of the polypropylene resin before irradiation. A method of making a resin is described.
However, the invention described in this patent document has a problem that it is difficult to easily obtain a polypropylene-based modified resin because of the large equipment required to use radiation.

On the other hand, various studies have been made on chemical cross-linking with organic peroxides. In Patent Document 2 below, a polypropylene resin having a predetermined melt mass flow rate value and a specific organic peroxide are melt-kneaded. Thus, it is described that a polypropylene-based modified resin is produced.
Patent Document 3 below describes that a polypropylene-based modified resin is prepared by adding a component such as fumaric acid or maleic acid to a polypropylene-based resin and melt-kneading it with an organic peroxide.
In the inventions described in these patent documents, since the polypropylene-based modified resin is produced by melt-kneading, it can be said that the production method is simpler than the method using radiation.
However, as in the invention described in Patent Document 2, it is difficult to effectively cause the organic peroxide to improve the melt tension simply by melt-kneading the polypropylene resin and the organic peroxide. It may be difficult to obtain an effect of improving the melt tension commensurate with the amount of organic peroxide added.
On the other hand, although the invention described in Patent Document 3 is easier to improve the melt tension than the invention described in Patent Document 2, this is an effect of components such as fumaric acid and maleic acid, and is a polypropylene-based modified resin using an organic peroxide. However, the crosslinking efficiency itself is not improved.
Further, since the above-described components are essential in the invention described in Patent Document 2, there is also a problem that extra labor is easily generated in the man-hours related to blending and kneading.

As described above, conventionally, it has been difficult to effectively cause the crosslinking of the polypropylene resin with the organic peroxide to improve the melt tension, and it is possible to efficiently obtain a polypropylene-based modified resin having a high melt tension. It has become difficult.
In addition, this has the problem that it is difficult to obtain a polypropylene-based modified resin that can be easily produced while having a high melt tension.

Japanese Patent Laid-Open No. 62-121704 Japanese Patent No. 4267187 Japanese Patent No. 4010141

  In view of the above problems, the present invention provides a method for efficiently obtaining a polypropylene-based modified resin having a high melt tension, and thus can be easily produced while having a high melt tension. An object is to provide a polypropylene-based modified resin.

The present invention has been made to solve the above-mentioned problems, and the present invention relating to a method for producing a polypropylene-based modified resin includes a copolymer of ethylene and propylene, an α-olefin having 4 to 10 carbon atoms and propylene. And resin particles having an average particle size of 0.1 mm or more and 2.0 mm or less and dicetyl obtained by pulverizing pellets made of a polypropylene resin composed of at least one of homopolypropylene and homopolypropylene Peroxydicarbonate consisting of at least one of peroxydicarbonate and dimyristyl peroxydicarbonate, the peroxydicarbonate is 0.5 parts by mass or more and 3.0 parts by mass with respect to 100 parts by mass of the polypropylene resin. Supply to the extruder at the following ratio, melt knead, and has a higher melt tension than the polypropylene resin It is characterized by the production of polypropylene modified resin.

The present invention relating to a polypropylene-based modified resin is a polypropylene-based modified resin that has been modified so that the polypropylene-based resin is crosslinked with peroxydicarbonate to have a higher melt tension than the polypropylene-based resin. It is obtained by pulverizing pellets made of a polypropylene resin composed of one or more of ethylene-propylene copolymer, copolymer of α-olefin having 4 to 10 carbon atoms and propylene, and homopolypropylene. The resin particles having an average particle diameter of 0.1 mm to 2.0 mm and peroxydicarbonate composed of at least one of dicetyl peroxydicarbonate and dimyristyl peroxydicarbonate are contained in 100 parts by mass of the polypropylene resin. On the other hand, the peroxydicarbonate is 0.5 parts by mass or more and 3.0 quality. Parts are fed into the extruder at a rate to become less, it is reformed said modified by being melt-kneaded in the extrusion machine is characterized in that it has a more melt tension 3cN at 230 ° C..

Polypropylene-based resins are generally commercially available in the form of pellet-shaped particles having a diameter of about 3 to 5 mm. However, when supplying resin pellets of such a size to an extruder or the like and melt-kneading them, Since the heat capacity of each grain is large, the state in which the remainder remains undissolved even if a part is melted is continued in the extruder for a certain period of time.
On the other hand, peroxydicarbonate is cleaved when the temperature of the resin rises to some extent to generate radicals. Therefore, generally commercially available polypropylene resin pellets and peroxydicarbonate are simply melt-kneaded. If only this is done, radicals are likely to be generated in the state where a part of the pellets remains undissolved, and the crosslinking efficiency may not be sufficient.

In the present invention, since resin particles having an average particle diameter of 0.1 mm or more and 2.0 mm or less, which is smaller than conventional resin pellets, are used, the whole is easily brought to a uniform temperature, and uneven melting of the resin particles is eliminated. This can prevent the problem that the activity of peroxydicarbonate increases before acting on the crosslinking reaction sufficiently.
Therefore, a high melt tension polypropylene-based modified resin can be obtained efficiently.

Embodiments of the present invention will be described.
In producing the polypropylene-based modified resin of the present invention, a) polypropylene-based resin particles and b) peroxydicarbonate are used as starting materials.
In addition, the polypropylene-based modified resin of the present invention can appropriately contain various c) additives other than the above components.
In addition, the polypropylene-based modified resin of the present invention employs a method of melt-kneading an admixture containing the above-mentioned substances, and is usually melt-kneaded by an extruder and used as a raw material for foam molded products. It can be made in a state having a melt tension of 3 cN or more (at 230 ° C.) suitable as

  First, the starting material that constitutes the polypropylene-based modified resin of the present invention will be described.

a) Polypropylene resin The polypropylene resin is not particularly limited, and examples thereof include homopolypropylene, copolymers of propylene and other olefins, and the like to constitute the polypropylene-based modified resin of the present embodiment. As the component, a copolymer of propylene and another olefin is preferable.
The copolymer of propylene and another olefin may be either a random copolymer or a block copolymer, but is preferably a block copolymer because of excellent heat resistance.
In addition, as other olefin which comprises a copolymer with propylene, for example, in addition to ethylene, 1-butene, 1-pentene, 4-methyl 1-pentene, 1-hexene, 1-octene, 1-nonene And α-olefins having 4 to 10 carbon atoms such as 1-decene.

The polypropylene resin has a melt mass flow rate (MFR) of 0.2 g / 10 min or more and 15 g / min when tested at a test temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210: 1999 method B. The thing of 10 minutes or less is preferable.
The reason why the MFR of the polypropylene resin is preferably within such a range is that if the MFR is lower than the lower limit value, there is a possibility that an excessive load may be generated on an apparatus used for melt kneading such as an extruder. On the other hand, when the MFR is high, since the melt tension is usually low, if a polypropylene resin having an MFR exceeding the upper limit is used, it becomes difficult to impart the intended melt tension to the polypropylene modified resin. It is.
From such a viewpoint, the MFR of the polypropylene resin is preferably 0.3 g / 10 min or more and 10 g / 10 min or less, and particularly preferably 0.5 g / 10 min or more and 5 g / 10 min or less.

In addition, such a polypropylene-type resin can be contained in the said mixture individually or in mixture of multiple types.
Among these, when using 2 or more types of polypropylene resin, the value computed by the ratio (mass fraction) of the whole can be made into said MFR.
For example, when the polypropylene resin used is a mixture of n types, the MFR of the polypropylene resin is measured by the above measuring method, and the obtained MFR value is calculated as the MFR of the first polypropylene resin. “MFR1”, the first polypropylene resin when the MFR of the second polypropylene resin is “MFR2”, and the melt mass flow rate of the nth polypropylene resin is “MFRn”. The mass fraction of the polypropylene resin is “C1”, the mass fraction of the second polypropylene resin is “C2”, and the mass fraction of the nth polypropylene resin is “Cn”. It is calculated by taking a geometric average as in the following formula.

MFR of polypropylene resin (g / 10min)
= (MFR1) ^C1 x (MFR2) ^C2 x ... x (MFRn) ^Cn
(However, C1 + C2 + ... Cn = 1)

Here, in this embodiment, it is important to use resin particles having an average particle diameter of 0.1 mm or more and 2.0 mm or less.
Since commercially available polypropylene resin pellets usually have a diameter of about 3 to 5 mm, in order to obtain resin particles having such an average particle diameter, mechanically by a pulverizer or the like. A method of pulverizing, a method of dissolving and dissolving a resin in a solvent and then spray drying, a method of cutting a strand extruded by an extruder with a pelletizer, or a method of granulating a resin extruded from an extruder with a hot cut facility Is mentioned.

In addition, although the method using an extruder can obtain resin particles having a uniform size, stress due to heat and shear is applied to the polypropylene resin.
Also, the method of spray drying after dissolving the resin in a solvent or the like is easy to obtain porous resin particles, although it takes time and effort to recover and regenerate the vaporized solvent. In the case of being supplied to the extruder in the form of powder, it becomes easy to adhere (adsorb) these to the surface.
That is, the resin particle which can suppress uneven distribution in the extruder of peroxydicarbonate can be obtained.
Furthermore, although the pulverization method tends to cause an increase in the particle size distribution as compared with a method using an extruder or a method using a solvent, the shape of the obtained resin particles is usually indefinite and a particle having a large specific surface area is obtained. This is advantageous for adhesion (adsorption) of peroxydicarbonate.
Moreover, it can be said that the pulverization method is excellent in that it does not require labor as in the case of using a solvent.

  As this pulverization method, a method such as a centrifugal pulverization method using a CUM type centrifugal mill that rotates a cutting blade or a freeze pulverization method in which resin pellets are pulverized at an extremely low temperature can be employed.

Note that it is important that the average particle diameter is in the range of 0.1 mm or more and 2.0 mm or less. If the average particle diameter is larger than 2 mm, melting unevenness occurs in the extruder and the par This is because it becomes difficult to maintain a balance between the decomposition rate of oxydicarbonate and the melting behavior of the polypropylene resin.
In addition, when the average particle size is less than 0.1 mm, the amount of input to the extruder is reduced because the bulk density is small although there is a low possibility of causing a problem from the viewpoint of the balance with the decomposition rate of peroxydicarbonate. This may reduce the productivity of the polypropylene-based modified resin.

In addition, the average particle diameter of the resin particles can be measured, for example, in the following manner.
Aperture 4.00 mm, Aperture 3.35 mm, Aperture 2.80 mm, Aperture 2.36 mm, Aperture 2.00 mm, Aperture 1.70 mm, Daily Aperture 1.40 mm, Aperture 1.18 mm, Aperture 1.00 mm, aperture 0.85 mm, aperture 0.71 mm, aperture 0.60 mm, aperture 0.50 mm, aperture 0.425 mm, aperture 0.355 mm, aperture 0.300 mm, aperture 0. Set JIS standard sieve with 250mm, 0.212mm aperture, and 0.180mm aperture on a low-tap type sieve shaker (made by Iida Seisakusho Co., Ltd.), classify about 50g of sample over 10 minutes, and sample on sieve mesh Measure the weight.
Next, an arithmetic average value of the mesh opening of each sieve and the mesh opening of the mesh having the next largest mesh after this mesh is obtained and used as the particle size value of the mesh.
In addition, in the case of a sieve having a mesh opening of 4.00 mm, the mesh opening of the JIS standard sieve having the next largest mesh opening is 4.75 mm. An arithmetic average value of 4.375 mm with an opening of 4.00 mm is taken as the particle size value.
The particle size value of the resin particles remaining on the sieve is determined for each sieve as described above, the mass of the resin particles remaining on the sieve is calculated for each sieve, and the mass of the resin particles remaining on each sieve is calculated. Divide by the total mass of the measurement sample to calculate the mass percentage.
And about each sieve, the mass percentage of the resin particle which remained on this sieve and all the sieves which have an opening smaller than the sieve is totaled, and let this value be a cumulative mass percentage.
Next, a graph with the horizontal axis as the particle size value and the vertical axis as the cumulative mass percentage is prepared, and the particle size value and cumulative mass percentage determined for each sieve are plotted on this graph as a set of data. Create an approximate curve connecting the two.
On the approximate curve, the particle diameter (median diameter) at which the cumulative mass percentage is 50% by mass is defined as the average particle diameter.

b) Peroxydicarbonate The peroxydicarbonate is an organic peroxide and acts as a cross-linking agent for polypropylene resins.
Specifically, diethyl peroxydicarbonate, dipropyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-n-butyl peroxydicarbonate, bismethoxybutyl peroxydicarbonate, bis-2-ethylhexyl peroxydicarbonate, Examples include dioctyl peroxydicarbonate, bis-t-butylcyclohexyl peroxydicarbonate, dimyristyl peroxydicarbonate, dicetyl peroxydicarbonate, among others bis-t-butylcyclohexyl peroxydicarbonate, dimyristyl peroxydicarbonate. Carbonate and dicetyl peroxydicarbonate are preferred because they have a high self-accelerating decomposition temperature (SADT) and are excellent in thermal stability and handling during storage.

In addition, the compounding quantity of this peroxydicarbonate and the said polypropylene resin is 0.5 to 3.0 mass parts with respect to 100 mass parts of the said polypropylene resin (in the case of multiple types, the total amount). The ratio is as follows.
The reason why the amount of peroxydicarbonate is within the above range is that if it is less than the above lower limit value, it becomes difficult to impart sufficient melt tension to the polypropylene-based modified resin, and the above upper limit. Even if it exceeds the value, the effect of improving the melt tension corresponding to the blending amount is not obtained, but the decomposed peroxydicarbonate causes problems of odor and fuming, and gelation occurs due to excessive reaction. It is because there is a possibility of doing.

In addition, when organic peroxides other than those based on peroxydicarbonate are used, it is easy to cause decomposition of the polypropylene resin at the time of melt kneading, and it is difficult to form a crosslinked structure effective for improving the melt tension. is there.
In addition, since crosslinking by organic peroxide is caused by a reaction in which the radical generated by thermal decomposition of the organic peroxide pulls out protons from the polymer, the radical generated by the organic peroxide is recombined to form a radical. May disappear, or the generated radicals may cut the molecular chain of the polypropylene resin and cause a decrease in molecular weight.
Moreover, if it reacts with another substance not intended, the crosslinking efficiency is extremely lowered, and there is a possibility that a good crosslinked structure cannot be imparted to the polypropylene-based modified resin.
Therefore, it is important to react with a crosslinking agent or the like faster than the generated radical causes a recombination reaction or the like to stabilize the generated radical and increase the crosslinking efficiency.

In such a point, the polypropylene-based modified resin according to the present embodiment is such that resin particles having an average particle size smaller than that of generally used polypropylene-based resin pellets are extruded together with a peroxydicarbonate-based organic peroxide. It is obtained by melt-kneading.
That is, in the method for producing a polypropylene-based modified resin according to the present embodiment, the entire polypropylene-based resin is uniformly melted before radicals are actively generated by the peroxydicarbonate-based organic peroxide. It can be formed in the extruder, and peroxydicarbonate can be prevented from being wasted or the polypropylene resin can be reduced in molecular weight.
For this reason, the polypropylene-based modified resin according to the present embodiment can be efficiently produced so as to have a high melt tension of 3 cN or more.

c) Additives In addition to the components a) and b), various additives can be included as starting materials for the polypropylene-based modified resin according to this embodiment.
This additive may be added when the components a) and b) are melt-kneaded, or the components a) and b) may be once melt-kneaded and then mixed again.
Specific examples of the additive include, but are not limited to, a weather resistance stabilizer, an antistatic agent, an antioxidant, a light stabilizer, a crystal nucleating agent, a pigment, a dye, a lubricant, a slipperiness, and an antiblocking property. Surfactants, inorganic fillers and higher fatty acids, higher fatty acid esters or higher fatty acid amides for the purpose of improving the dispersibility thereof.

  Next, a method for producing a polypropylene-based modified resin using these components to produce a polypropylene-based modified resin will be described.

  In the method for producing a polypropylene-based modified resin according to this embodiment, there is a method in which the above components are melt-kneaded using an extruder, and the above components are continuously supplied to the extruder and crosslinked in the extruder. A method of continuously discharging the polypropylene-based modified resin formed from the extruder while reacting to form a polypropylene-based modified resin can be employed.

Examples of the extruder include a single-screw extruder, a twin-screw extruder, and the like, and these can be used for producing a polypropylene-based modified resin as a single or a plurality of connected tandem types.
In particular, a twin screw extruder is suitable from the viewpoint of dispersibility and reactivity of other compounding agents with respect to the polypropylene resin as the base resin.
First, resin particles and peroxydicarbonate are introduced into this extruder at room temperature, and then heated by heat transfer from the inner wall of the cylinder, etc. as the inside of the extruder proceeds while being stirred by a screw. Will be.
At this time, if the particle size of the resin particles is large, the heat capacity of each particle is large, so even if a part of the particles is melted, the remaining portion is not sufficiently softened.
If it does so, it will be in the state in which resin (henceforth "the unmelted part") which is not completely melt | dissolved disperses in high temperature molten resin.
Thus, peroxydicarbonate actively generates radicals as the resin temperature of the molten resin rises, resulting in the generation of radicals in a state where the molten resin and unmelted components are mixed. .

When radicals are generated in this manner, excessive radicals are supplied to the molten resin that is likely to cause a crosslinking reaction. Compared to this, radical recombination is likely to occur.
At this time, the molten resin is brought into an effective state for improving the melt tension by a crosslinking reaction, but thereafter, the crosslinked polypropylene resin is diluted by an unmelted portion that has not been crosslinked.
That is, the effect of improving the melt tension is sufficiently achieved by the fact that a polypropylene resin that is not in a state capable of undergoing a crosslinking reaction at the radical generation peak is easily present, and that the crosslinking efficiency of the organic peroxide is not sufficient. It may not be demonstrated.

  On the other hand, by supplying resin particles adjusted to an average particle diameter of 0.1 mm or more and 2.0 mm or less to the extruder as described above, the whole tends to have a uniform temperature, and crosslinking occurs at the radical generation peak. The possibility of forming an unmelted portion that is not in a reactive state can be reduced.

Although not described in detail here, the temperature setting of the extruder and the average residence time in the extruder can be appropriately adjusted for the extrusion conditions such as the type of screw used and the rotation speed, and these conditions should be adjusted. Can adjust the melt tension of the polypropylene-based modified resin obtained to be 3 cN or more (at 230 ° C.).
When this polypropylene-based modified resin is used as a raw material for foam molded articles, the melt tension is preferably 3 cN or more, and more preferably 5 cN or more.
In addition, although it does not specifically limit about an upper limit, Usually, the melt tension of the polypropylene-type modified resin which concerns on this embodiment is 30 cN or less, and it is preferable to set it as 20 cN or less.

As described above, according to the present invention, a polypropylene-based modified resin having a high melt tension suitable for forming a foam-molded product can be obtained by a simple means of melt kneading with an extruder.
In the present embodiment, the case where a polypropylene-based modified resin is produced using polypropylene-based resin particles is exemplified, but the present invention is not limited to the above, and a resin that is a starting material for a polypropylene-based modified resin The particles may slightly contain a resin other than a polypropylene resin as long as the average particle diameter is 0.1 mm or more and 2.0 mm or less.
That is, as long as the resin particles have a polypropylene resin as a main component, there is no change in that the polypropylene modified resin can be efficiently produced even if a resin other than the polypropylene resin is contained.
For example, if a polyolefin resin having a high compatibility with a polypropylene resin such as a polyethylene resin is about 10% by mass or less, the same type of effect can be obtained even if the resin particle contains the resin. This is the intended scope of the invention.
Further, components such as fumaric acid and maleic acid as described in Patent Document 3 (Patent No. 4010141) are appropriately added, and polyfunctional unsaturated monomer components such as divinylbenzene and trimethylolpropane triacrylate are appropriately added. Thus, the melt tension may be further improved.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

Example 1
Polypropylene resin pellets (manufactured by Sun Allomer, homopolypropylene resin, trade name “PL500A”, average particle size 3.7 mm, MFR = 3.3 g / 10 min) are placed in a CUM type centrifugal mill (model: CUM150, manufactured by Mitsui Mining Co., Ltd.). The resulting mixture was pulverized to produce polypropylene resin particles having an average particle diameter of 0.7 mm.
Ribbon blender of the dicetyl peroxydicarbonate and the resin particles at a ratio of 0.5 parts by mass of dicetyl peroxydicarbonate with respect to 100 parts by mass of polypropylene resin particles having an average particle diameter of 0.7 mm. Is supplied to a twin screw extruder (L / D = 47) with a diameter of 30 mm, melted and kneaded in a twin screw extruder at a resin temperature of 200 ° C. and a rotation speed of 150 rpm, and attached to the tip. The polypropylene-based modified resin was extruded in a strand form from a die having a diameter of 4 mm, a land of 5 mm, and two holes, at a discharge rate of 5 kg / h.
Next, the strand-like polypropylene-based modified resin was passed through a 2 m long cooling water tank containing 30 ° C. water, cooled, and cut with a pelletizer to obtain a pellet made of the polypropylene-based modified resin.
Table 1 shows the results of measurement of melt tension using the pellets.
The melt tension was measured as follows.

(Measurement of melt tension)
A polypropylene-based modified resin serving as a sample was accommodated in a cylinder with an inner diameter of 15 mm arranged in the vertical direction of a twin bore capillary rheometer (Rheological 5000T) manufactured by Thiast, and heated at 230 ° C. for 5 minutes to be melted. Later, a piston was inserted from the upper part of the cylinder, and a capillary (die diameter: 2.095 mm, die length: provided at the lower end of the cylinder so that the extrusion speed was a constant speed of 0.0773 / s with the piston. The molten resin was extruded in a string shape from 8 mm, inflow angle: 90 degrees (conical), and then wound up using a winding roll.
At this time, the initial speed at the beginning of winding is 4 mm / s, the subsequent acceleration is 12 mm / s ² , the winding speed is gradually increased, and the winding speed when the tension observed by the tension detection pulley is drastically reduced is set. The breaking point speed was determined, and the maximum tension until the breaking point speed was observed was measured as the melt tension.

(Examples 2-3)
A polypropylene modified resin was prepared in the same manner as in Example 1 except that the amount of dicetyl peroxydicarbonate was changed as shown in Table 1, and the melt tension of the obtained polypropylene modified resin was measured. It was. The results are shown in Table 1.

(Example 4)
A polypropylene modified resin was prepared and obtained in the same manner as in Example 1 except that freeze pulverization was performed instead of the crushing method using a centrifugal mill and polypropylene resin particles having an average particle diameter of 0.2 mm were used. The melt tension of the polypropylene-based modified resin was measured. The results are shown in Table 1.

(Examples 5-7)
Except that the polypropylene resin single body was supplied to an extruder, extruded into a strand shape, repelletized by a pelletizer, and the average particle size shown in Table 1 was adopted instead of the crushing method by a centrifugal mill. A polypropylene-based modified resin was prepared in the same manner as in Example 1, and the melt tension of the obtained polypropylene-based modified resin was measured. The results are shown in Table 1.

(Example 8)
A polypropylene modified resin was prepared in the same manner as in Example 1 except that dimyristyl peroxydicarbonate was used instead of dicetyl peroxydicarbonate, and the melt tension of the obtained polypropylene modified resin was measured. went. The results are shown in Table 1.

Example 9
Polypropylene-based resin pellets were changed to the product name “PM500A” (homopolypropylene resin, MFR = 7.5 g / 10 min) instead of the product name “PL500A” manufactured by Sun Allomer Co., Ltd. A resin was prepared, and the melt tension of the obtained polypropylene-based modified resin was measured. The results are shown in Table 1.

(Comparative Example 1)
A polypropylene-based modified resin was produced in the same manner as in Example 1 except that the polypropylene-based resin pellets were used as they were without being pulverized or repelletized. The melt tension was measured. The results are shown in Table 2.

(Comparative Example 2)
A polypropylene modified resin was prepared in the same manner as in Example 1 except that the repellet size obtained by the pelletizer was set to the average particle size shown in Table 2, and the melt tension of the obtained polypropylene modified resin was obtained. Was measured. The results are shown in Table 2.

(Comparative Example 3)
A polypropylene-based modified resin was prepared in the same manner as in Example 1 except that the amount of dicetyl peroxydicarbonate was 0.2 parts by mass with respect to 100 parts by mass of the polypropylene-based resin particles. The melt tension of the modified resin was measured. The results are shown in Table 2.

(Comparative Example 4)
A polypropylene modified resin was prepared in the same manner as in Example 1 except that 0.3 part by mass of dicumyl peroxide was used instead of 0.5 part by mass of dicetyl peroxydicarbonate, and the resulting polypropylene modified The melt tension of the resin was measured. The results are shown in Table 2.

(Comparative Example 5)
A polypropylene resin pellet was produced by extruding a polypropylene resin pellet with an extruder in the same manner as in Example 1 except that dicetyl peroxydicarbonate was not added.
Table 2 shows the results of measurement of the melt tension of the obtained polypropylene resin pellets.

(Comparative Example 6)
Polypropylene resin pellets in the same manner as Comparative Example 5 except that the polypropylene resin pellets were replaced by the trade name “PL500A” manufactured by Sun Allomer Co., Ltd. and the trade name “PM600A” (homopolypropylene resin, MFR = 7.5 g / 10 min). Was made.
Table 2 shows the results of measurement of the melt tension of the obtained polypropylene resin pellets.

  Also from this table, it can be seen that according to the present invention, a high melt tension polypropylene-based modified resin can be produced efficiently.

Claims (3)

Obtained by pulverizing a pellet made of a copolymer of ethylene and propylene, a copolymer of α-olefin having 4 to 10 carbon atoms and propylene, and a polypropylene resin composed of one or more of homopolypropylene. The resin particles having an average particle diameter of 0.1 mm or more and 2.0 mm or less and peroxydicarbonate composed of at least one of dicetyl peroxydicarbonate and dimyristyl peroxydicarbonate, 100 parts by mass of the polypropylene resin In contrast, the peroxydicarbonate is supplied to an extruder at a ratio of 0.5 parts by mass or more and 3.0 parts by mass or less, melt-kneaded, and has a polypropylene modification having a higher melt tension than the polypropylene resin. A method for producing a polypropylene-based modified resin, which comprises producing a resin. Melt mass flow rate of the polypropylene resin 0.2 g / 10min or higher, The process according to claim 1 Symbol placement of polypropylene modified resin is 15 g / 10min or less. A polypropylene-based modified resin that has been modified so that the polypropylene-based resin is crosslinked with peroxydicarbonate to have a higher melt tension than the polypropylene-based resin,
Obtained by pulverizing a pellet made of a copolymer of ethylene and propylene, a copolymer of α-olefin having 4 to 10 carbon atoms and propylene, and a polypropylene resin composed of one or more of homopolypropylene. The resin particles having an average particle diameter of 0.1 mm or more and 2.0 mm or less and peroxydicarbonate composed of at least one of dicetyl peroxydicarbonate and dimyristyl peroxydicarbonate are 100 parts by mass of the polypropylene resin. The peroxydicarbonate is supplied to the extruder at a ratio of 0.5 parts by mass or more and 3.0 parts by mass or less, and is modified by being melt-kneaded in the extruder, 230 ° C. A polypropylene based modified resin characterized by having a melt tension of 3 cN or more.