JP2009275123A - Modified polyproylene based resin composition, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress generation of odor and generation of a hue problem in a molded article caused by addition of an organic peroxide when melting tension is enhanced by the organic peroxide, and to improve various kinds of moldabilities as much as possible by sufficiently attaining enhancement of the melting tension in a polypropylene based resin material. <P>SOLUTION: The modified polypropylene based resin composition is constituted of 50-97 wt.% of component (A) and 50-3 wt.% of component (B) and obtained by adding 0.1-3 pts.wt. of a peroxy dicarbonate having a temperature of 50-80°C giving 1 hour as a half life period to 100 pts.wt. of the polypropylene based resin composition (C) having physical properties of C-1 and C-2 and melting/kneading the mixture at 160-270°C. Component (A): a propylene homopolymer having an MFRa (at 2.16 kg load at 230°C) of 1-1,000 g/10 min or a propylene based copolymer having an olefin content other than propylene of 1 wt.% or less. Component (B): a propylene homopolymer having an MFRb of 0.1 g/10 min or less or a propylene based copolymer having an olefin content other than propylene of 15 wt.% or less. C-1: an MFRc of the composition (C) is 0.1-20 g/10 min C-2: melting tension (MTc) at 230°C and the MFRc of the composition (C) satisfy the relationship of the equation: log (MTc)>-0.9×log (MFRc)+0.6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a modified polypropylene resin composition and a method for producing the same, and specifically, a polypropylene resin composition having high melt tension and excellent moldability, and a specific polypropylene resin composition are specified. It relates to the manufacturing method by treating with peroxide.

A plastic material that is heavily used as an industrial basic material is widely used by being formed into a desired article in various technical fields because of its ease of molding.
Among polyolefin resins, which are the main materials among plastic materials, polypropylene resins are excellent in mechanical properties, processability, physical properties, chemical properties, economy, adaptability to environmental problems, etc. However, as one of the few disadvantages, the melt tension related to moldability is generally low, and the moldability is improved by extrusion molding, vacuum molding, inflation molding, foam molding and other molding methods. Inferior cases are derived.

  Specifically, for example, in extrusion molding, it is difficult to perform high-speed molding, and it is difficult to obtain a large-sized extruded product. When vacuum forming using a sheet, it is difficult to obtain a large-sized molded product. Drawing is also difficult, and when forming a film by the inflation molding method, bubbles tend to be unstable, and foam molding tends not to make foaming at a high foaming rate, and the foam cell size tends to be non-uniform Difficult to avoid. In addition, there is a problem that high-speed productivity is not sufficiently achieved in various molding methods.

Thus, in order to cope with such problems in the polypropylene resin material, various methods have been proposed to improve the melt tension of the polypropylene resin and improve the moldability and high-speed productivity. Melt tension can be improved by partially crosslinking the polypropylene resin or causing long-chain branching.
For this purpose, for example, a method in which an organic peroxide and a crosslinking aid are reacted with polypropylene in a molten state (see Patent Document 1), a peroxide having a low decomposition temperature is reacted with semicrystalline polypropylene in the absence of oxygen. Thus, a method for producing a polypropylene having free-end long-chain branching and containing no gel (see Patent Document 2) is disclosed. In addition, a method for generating long-chain branches in polypropylene by high-energy ionizing radiation has also been proposed (see Patent Document 3), but any of these methods uses an organic peroxide or radiation on a polymer chain. A radical is generated in this, and this reacts to cause a long chain branching in the polymer chain, thereby improving the melt tension. In these methods, the method using an organic peroxide is industrially superior to the method of irradiating high-energy ionizing radiation in that an expensive facility is unnecessary.
Recently, it has been known that peroxydicarbonates are effective for improving the melt tension of polypropylene, and a polypropylene having a high melt tension modified with di-2-ethylhexyl peroxydicarbonate has been disclosed. (Refer patent document 4), The method of obtaining the polypropylene resin which has high melt tension by reaction at the temperature of 150-300 degreeC using various peroxydicarbonates is also proposed (refer patent document 5). ).

Furthermore, the polypropylene resin is defined from another viewpoint, and the melt tension (MT) and the melt flow ratio (MI) are defined by specific parameter formulas as a composition that has a good balance between melt tension and fluidity. A composition of a modified polypropylene resin containing a polar group and a silane coupling agent is also disclosed (see Patent Document 6).
Furthermore, instead of improving the melt tension of the polypropylene resin itself, a technique for improving the melt tension of the polypropylene resin in the embodiment of the resin composition has also been proposed. ) In the composition of polymer, propylene homopolymer and ethylene-propylene copolymer, the melt flow rate ratio, the intrinsic viscosity ratio and the weight ratio are defined, the melt properties are high, and the physical properties of the molded article are excellent. A propylene (co) polymer polymerization method using a transition metal catalyst, a propylene prepolymerization step, an ethylene / olefin random copolymer prepolymerization step, and an ethylene Manufactured by polymerization process including pre-polymerization process, high melt tension and excellent moldability Such as an olefin polymer composition (see Patent Document 8) have been disclosed.

Similar to the polypropylene resin composition described above, proposals have been made to improve the melt tension of a polypropylene block copolymer or polypropylene resin by a method not using an organic peroxide or high-energy ionizing radiation (Patent Literature). 9 and 10), Patent Document 9 includes a high molecular weight polypropylene, a low molecular weight polypropylene and an ethylene / α-olefin copolymer whose intrinsic viscosity is defined, and a 23 ° C. paraxylene soluble component amount, a molecular weight distribution, and the like. It is said that a polypropylene block copolymer having a specified is excellent in moldability with high melt tension.
In Patent Document 10, the MFR is 10 to 1,000 g / 10 min. A propylene homopolymer having a olefin content of 50 to 90% by weight, and a weight average molecular weight of 500,000 to 10 million and an olefin content other than propylene of 1 to 15%. A resin composition comprising 50% to 10% by weight of a propylene copolymer and satisfying specific physical properties such as the relationship between melt tension and MFR and the longest relaxation time has high melt tension, and blow molding and foam molding. In addition, it is considered excellent as a raw material for extrusion molding and the like.

  As outlined above, in the polypropylene resin material, various various methods for improving the melt tension and improving the moldability have been disclosed so far. There is a problem of odor generation and hue deterioration in the molded product due to the addition of peroxide. The radiation irradiation method increases the equipment cost of the manufacturing process, and the method that does not use organic peroxide or radiation irradiation is the manufacturing cost. Is relatively inexpensive and excellent in food hygiene without problems of odor and hue, but the improvement in melt tension is generally not sufficient, and further improvement in moldability is required.

JP 59-93711 A (see claims and lower left column on page 1) JP-A-2-298536 (refer to the claims) JP 62-121704 A (see claim 5) Japanese Patent Laid-Open No. 6-157666 (refer to claim 4 of claims) WO99 / 27007 publication (see claims 1 and 7 on page 18) JP 2004-99632 A (see summary) No. 98-46677 (see summary) JP 2008-37908 A (see summary) JP 2000-290333 A (see abstract) JP 2001-335666 A (see abstract)

As outlined in the background art, in a polypropylene resin material, various methods have been studied and various methods have been disclosed so far in order to improve melt tension and improve moldability. In the method using organic oxide, there is a problem of odor generation and hue deterioration in the molded product due to the addition of organic peroxide, and the radiation irradiation method increases the equipment cost of the manufacturing process, and organic peroxide and radiation In methods that do not use irradiation, the melt tension improvement is generally not sufficient.
Therefore, the present invention suppresses the generation of odors and hue problems in molded products due to the addition of organic peroxides in polypropylene resin materials, and sufficiently improves the melt tension without increasing the manufacturing equipment costs. Therefore, it is an object of the present invention to improve various moldability as much as possible.

  In order to solve this problem, the present inventors have considered from various viewpoints based on various improved methods that have been disclosed in the past, and the improvement of the melt tension by organic peroxide is the most effective method. In addition, since the production cost is low, this method seeks an improved method that can increase melt tension more efficiently and suppress the occurrence of odor generation and hue problems in molded products as much as possible. In the process of verification considering the type of resin material, composition of the composition or selection of organic peroxide and its usage, peroxydicarbonate was selected as the organic peroxide, and a specific melt flow rate ( If a polypropylene-based composition component having an MFR) relationship is adopted, a specific composition and MFR are provided as the composition, and the relationship between the melt tension and the MFR is specified and defined, the above And found that can make solving the problems has led to the creation of the present invention as a result.

Thus, in the present invention, the melt flow rate at 230 ° C. and 2.16 kg load (hereinafter abbreviated as “MFR”; the measurement conditions are the same hereinafter) is 1 to 1,000 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less, and an MFR of 0.1 g / 10 min. A propylene homopolymer or a propylene-based copolymer having an olefin content other than propylene of 15% by weight or less is selected as a composition component, the component amount ratio thereof is also specified, and physical properties in the composition are MFR and By defining the numerical relationship between MFR and melt tension, selecting peroxydicarbonate having a temperature of 50 to 80 ° C. as a half-life as an organic peroxide and melting and kneading at 160 to 270 ° C. The main component of the invention is to modify the polypropylene resin composition.
Here, the component amount ratio of the composition is (50 to 97) / (50 to 3)% by weight, 0.1 to 3 parts by weight of a peroxide is added to 100 parts by weight of the composition, and the MFR of the composition is 0.1-20 g / 10 min. The numerical relationship between the MFRc and the melt tension (MTc) is defined by the following equation (1).
log (MTc)> − 0.9 × log (MFRc) +0.6 (Expression 1)

  An embodiment of the present invention is a modified polypropylene resin composition in which another thermoplastic resin component (E) is further added to the modified polypropylene resin composition, and the resin composition The product (C) is obtained by a multi-stage polymerization method in which the component (A) and the component (B) are continuously produced. The peroxydicarbonate is dicetyl peroxydicarbonate, and is further modified. And a molded product obtained by molding a polypropylene resin composition.

As described above in paragraph 0011, the present invention is composed of a component material having a specific MFR, has a specific component ratio and MFR, and a polypropylene resin composition in which the relationship between melt tension and MFR is defined by a mathematical formula Since the product is composed of the novel requirements of melting and kneading a specific organic oxide under specific conditions, in the polypropylene resin material of the present invention, (i) due to organic peroxide The treatment can be performed efficiently, and odor generation and hue problem derivation in the molded product due to the addition of the organic peroxide can be suppressed, and (ii) it is suitable for use in food packaging materials, (Iii) The production cost is low without increasing the equipment cost of the manufacturing process, and (iv) the effect of the invention is to improve the various moldability as much as possible by sufficiently improving the melt tension. Those having features of the invention.
And, it can be said that such a novel configuration and special features by the present invention are not insignificant even if each patent document and other patent documents mentioned above in the background art are scrutinized.

  In the above, the background of the creation of the present invention, the configuration of the invention, and the features of the operation and effects, etc. have been described generally. Therefore, in order to give an overview of the entire present invention, the entire configuration of the present invention is clearly described. When it describes, this invention consists of the following invention unit group, Comprising: The thing of [1] and [3] is a basic invention, and other invention is invention as an embodiment. (The invention unit group as a whole is collectively referred to as “the present invention”.)

[1] Basically composed of 50 to 97% by weight of the following component (A) and 50 to 3% by weight of (B) (provided that the total of components (A) and (B) is 100% by weight) Peroxydicarbonate 0.1 which is a temperature of 50 to 80 ° C. giving a half-life to 100 parts by weight of a polypropylene resin composition (C) having the following physical properties of C-1 and C-2 A modified polypropylene resin composition (D) obtained by adding ~ 3 parts by weight and melt-kneading at 160 ~ 270 ° C.
Component (A): Melt flow rate (MFRa) at 230 ° C. and 2.16 kg load is 1 to 1,000 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less (provided that the total of monomer units constituting the component (A) is 100% by weight)
Component (B): Melt flow rate (MFRb) at 230 ° C. and 2.16 kg load is 0.1 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 15% by weight or less (provided that the total of the monomer units constituting the component (B) is 100% by weight)
C-1: MFRc of the composition (C) at 230 ° C. and 2.16 kg load is 0.1 to 20 g / 10 min.
C-2: The melt tension (MTc) at 230 ° C. of the composition (C) and MFRc at 230 ° C. and 2.16 kg load satisfy the relationship of the following formula 1 log (MTc)> − 0.9 × log ( MFRc) +0.6 (Formula 1)
[2] A modified polypropylene resin composition (D) in which another thermoplastic resin component (E) is further blended with the modified polypropylene resin composition in [1].

[3] Basically composed of 50 to 97% by weight of the following component (A) and 50 to 3% by weight of (B) (provided that the total of components (A) and (B) is 100% by weight) Peroxydicarbonate 0.1 which is a temperature of 50 to 80 ° C. giving a half-life to 100 parts by weight of a polypropylene resin composition (C) having the following physical properties of C-1 and C-2 A method for producing a modified polypropylene-based resin composition (D), which comprises adding 3 parts by weight and melt-kneading at 160-270 ° C.
Component (A): Melt flow rate (MFRa) at 230 ° C. and 2.16 kg load is 1 to 1,000 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less (provided that the total of monomer units constituting the component (A) is 100% by weight)
Component (B): Melt flow rate (MFRb) at 230 ° C. and 2.16 kg load is 0.1 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 15% by weight or less (provided that the total of the monomer units constituting the component (B) is 100% by weight)
C-1: MFRc of the composition (C) at 230 ° C. and 2.16 kg load is 0.1 to 20 g / 10 min.
C-2: The melt tension (MTc) at 230 ° C. of the composition (C) and MFRc at 230 ° C. and 2.16 kg load satisfy the relationship of the following formula 1 log (MTc)> − 0.9 × log ( MFRc) +0.6 (Formula 1)
[4] The modified polypropylene according to [3], wherein the resin composition (C) is obtained by a multistage polymerization method in which the component (A) and the component (B) are continuously produced. For producing a resin-based resin composition (D).
[5] The method for producing a modified polypropylene resin composition (D) according to [3] or [4], wherein the peroxydicarbonate is dicetyl peroxydicarbonate.

  [6] A molded product obtained by molding the modified polypropylene resin composition (D) in [1] or [2].

  According to the present invention, when a polypropylene resin composition is modified with an organic peroxide, the treatment with the organic peroxide can be performed efficiently, and a smaller amount of organic peroxide is added than before. Therefore, it is possible to suppress the generation of odors and hue problems in molded products, which makes it suitable for use in food packaging materials, reduces production costs without increasing production equipment costs, and reduces melt tension. It is possible to improve the various moldability as much as possible by sufficiently improving and exhibiting the remarkable effect of the invention that it is excellent as a raw material for various molding methods such as blow molding, foam molding, extrusion molding and vacuum molding.

In the following, in order to describe the invention group in the present invention in detail, embodiments of the invention will be described in detail.
1. Configuration of Modified Polypropylene Resin Composition (D) (1) Basic Features The modified polypropylene resin composition (D) of the present invention comprises a component (A) and a component having specific MFR properties A specific organic peroxide is added to a specific MFR and a polypropylene resin composition (C) having a numerical relationship between MFR and melt tension, which is blended at a specific composition ratio, and melt kneaded. The modified resin composition has a high melt tension and improves the moldability of each molding method.

(2) Component (A)
A component (A) is a main component in the component which comprises a polypropylene resin composition (C), and the ratio for which it accounts in a resin composition (C) is 50 to 97 weight%.
Component (A) is a propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less (provided that the total of monomer units constituting component (A) is 100% by weight) .
Examples of olefins other than propylene include α-olefins having 2 to 20 carbon atoms, such as ethylene, 1-butene, 1-hexene, 4-methyl-pentene-1, 1-octene, and 1-decene. .
Component (A) is the main component of the resin composition (C). From the viewpoint of heat resistance of the resin composition obtained after modification, the content of olefins other than propylene is 1% by weight or less, preferably a propylene homopolymer. It is.

  The MFR of the component (A) at 230 ° C. and a load of 2.16 kg is 1 to 1,000 g / 10 min. It is said. Preferably, 3 to 300 g / 10 min. And more preferably 5 to 100 g / 10 min. It is. 1 to 1,000 g / 10 min. Those outside the above range are not suitable for various moldings such as blow molding, foam molding, extrusion molding and vacuum molding because the fluidity of the modified composition (D) is too low or too high.

  As the component (A), the polymer component having the above MFR may be used alone, or a mixture of a plurality of polymer components may be used. However, in the case of a mixture of a plurality of components, the MFR of each component is 1-1000 g / 10 min. It is necessary to have a range of When a plurality of polymer components are used, those obtained by mixing the components by mixing in solution or melt kneading may be used, or they may be obtained by using a multistage polymerization method.

(3) Component (B)
The component (B) is a subcomponent in the polypropylene resin composition (C), and the proportion of the component (B) in the resin composition (C) is 50 to 3% by weight.
Component (B) is a propylene homopolymer or a propylene-based copolymer having an olefin content other than propylene of 15% by weight or less (provided that the total of monomer units constituting component (B) is 100% by weight) .
Identification of the comonomer content in the components (A) and (B) can be performed by a conventionally known infrared absorption spectrum measurement, ¹³ C-NMR measurement or the like.
Examples of olefins other than propylene include α-olefins having 2 to 20 carbon atoms, such as ethylene, 1-butene, 1-hexene, 4-methyl-pentene-1, 1-octene, and 1-decene. . Of these, ethylene is preferred.
Depending on the comonomer content, there is a difference in the effect of modification with an organic peroxide, preferably 0.5 to 10% by weight, more preferably 1 to 7% by weight. When the comonomer content exceeds 15% by weight, the affinity with the component (A) deteriorates, and the effect of improving the melt tension decreases.

  The MFR of the component (B) at 230 ° C. and a load of 2.16 kg is 0.1 g / 10 min. It is as follows. MFR is 0.1 g / 10 min. In the case of a material exceeding 1, the effect of improving the melt tension becomes insufficient.

  As the component (B), the polymer component having the above MFR may be used alone, or a mixture of a plurality of polymer components may be used. However, in the case of a mixture of a plurality of components, the MFR of each component is 0.1 g / 10 min. It is necessary to have the following ranges: When a plurality of polymer components are used, those obtained by mixing the components by mixing in solution or melt kneading may be used, or they may be obtained by using a multistage polymerization method.

(4) Production of Component (A) and Component (B) As a catalyst system in the polymerization for obtaining component (A) and component (B), a Ziegler system mainly composed of a titanium-containing solid catalyst component and an organoaluminum compound. A catalyst or a metallocene-based transition metal compound having at least one π-electron conjugated ligand can be used.

The titanium-containing solid catalyst component is selected from a known supported catalyst component obtained by contacting a solid magnesium compound with titanium tetrahalide and an electron donating compound, or a known catalyst component containing titanium trichloride as a main component. .
The aluminum compound of the promoter is represented by the general formula AlR _n X _3-n (wherein R represents a hydrocarbon group having 2 to 10 carbon atoms, and n represents a number of 3 ≧ n> 1.5). The When the titanium-containing solid catalyst component is a carrier-supported catalyst component containing a solid magnesium compound, it is preferable to use AlR ₃ or a mixture of AlR ₃ and AlR ₂ X, with titanium trichloride or titanium trichloride being the main component. When the catalyst component is included as a component, it is preferable to use AlR ₂ X. Furthermore, in the present invention, a known electron donating compound can be used as the third component in addition to the above catalyst and cocatalyst components.

As the metallocene compound, aluminoxanes may be used as a co-catalyst, or may be used by being supported on silica or clay mineral.
Specific examples of the metallocene catalyst include the catalysts described in JP-A-8-85707, JP-A-8-183814, and JP-A-8-208733.

  The polymerization reaction for obtaining the polypropylene resin of component (A) and component (B) can be carried out in the absence or presence of an inert solvent such as hexane or heptane, that is, in the presence of liquid propylene or in gas phase propylene. Can be done.

(5) Resin composition (C)
In the resin composition (C) of the present invention, the component (A) is 50 to 97% by weight, and the component (B) is 50 to 3% by weight (provided that the total of the components (A) and (B) is 100% by weight) And a resin composition having the following physical properties of C-1 and C-2.
In addition, the mixing | blending of the other resin component (E) can also be performed. Further, “basically configured” means “consisting only of component (A) and component (B) or including other components”.
C-1: The melt flow rate (MFRc) of the composition (C) at 230 ° C. and a load of 2.16 kg is 0.1 to 20 g / 10 min.
C-2: The melt tension (MTc) at 230 ° C. of the composition (C) and the MFRc at a load of 2.16 kg at 230 ° C. satisfy the relationship of the following formula: log (MTc)> − 0.9 × log (MFRc) +0.6 (Expression 1)

Conventionally, it has been known that the MT value of a polypropylene resin has a correlation with MFR. Generally, the lower the MFR, the higher the MT. Since this relationship also applies to ordinary polypropylene resins that are not modified (not cross-linked and modified), various relational expressions have been proposed in the prior art as definitions of high melt tension.
For example, in Japanese Patent Application Laid-Open No. 2003-25425, as a definition of polypropylene having a high melt tension,
log (MS)> − 0.61 × log (MFR) +0.82 (230 ° C.)
A relational expression is proposed. Here, MS is synonymous with MT.
JP-A-2003-64193 discloses a definition of polypropylene having a high melt tension,
11.32 × MFR ^−0.7854 ≦ MT (230 ° C.)
A relational expression is proposed.
Furthermore, in Japanese Patent Application Laid-Open No. 2003-94504, as a definition of polypropylene having a high melt tension,
MT ≧ 7.52 × MFR ^−0.576
A relational expression is proposed. Here, MT is measured at 190 ° C., and MFR is measured at 230 ° C.
In both cases, when MT is plotted logarithmically with respect to MFR, the region is divided by a straight line having a certain negative slope, and in a certain MFR, the one having a value above the straight line is the high melt tension. It is what.

  Since the coefficients and indices of these mathematical formulas change depending on the measurement conditions such as the measurement temperature and the die to be used, in the present invention, referring to these prior arts, based on the MFR and MT data obtained in the experiment, Equation 1 is experimentally defined to determine whether the melt tension is high or low. That is, when Formula 1 is satisfied, it is determined that the melt tension is higher than that of a general polypropylene resin, and when it is not satisfied, it is determined that the melt tension is low (similar to a general polypropylene resin).

When the MFRc of the resin composition (C) is out of the above range (0.1 to 20 g / 10 min.), The fluidity is too low or too high, and various types such as blow molding, foam molding, extrusion molding, vacuum molding, etc. Not suitable for molding. Preferably 0.5 to 15 g / 10 min. More preferably, it is 1-10 g / 10min. Range.
Since the resin composition (C) contains a component (B) which imparts melt tension therein and has an effect of improving the reforming effect at the time of reforming with an organic peroxide, the resin composition (C) is more than a normal polypropylene resin. It is characterized by high melt tension. Therefore, the resin composition (C) needs to satisfy the relationship of the above (Formula 1), and preferably satisfies the following (Formula 2).
log (MTc)> − 0.9 × log (MFRc) +0.7 (Expression 2)
Here, the melt tension was measured at a temperature of 230 ° C., a die L / D = 40/2 mm, and a piston speed of 20 mm / min. -Pick-up speed 4.0m / min. It shall be measured at

2. Production of Resin Composition (C) The resin composition (C) is a composition (mixture) having a specific ratio of the component (A) and the component (B), and the production method thereof includes the component (A) polymerized in advance. And component (B) in a solution state, melt kneading, or batch production of component (A) and component (B) by a multi-stage polymerization method. The most preferable production method is a multistage polymerization method because MFR is greatly separated.

In the multistage polymerization method, the polymerization reaction can be carried out batchwise using one polymerization tank, or can be carried out continuously by connecting two or more polymerization tanks in series.
The order of polymerization is not particularly limited, but it is general that component (A) is first polymerized and then component (B) is polymerized. Therefore, the polymerization is preferably performed in two stages, and may be additionally performed in three or four stages in which polymerization is performed. For example, the component (A) may be polymerized in a plurality of stages, and the component (B) may be polymerized in a plurality of stages. However, at this time, each of the components constituting the component (A) and the component (B) satisfies the various characteristics of the component (A) and the component (B) described above.

  The equivalent component of component (A) or the equivalent component of component (B) can be further added to the resin composition comprising a part of component (A) and component (B) obtained by multistage polymerization by other methods. . For example, a part of the component (A) and the component (B) are produced by a multistage polymerization method, and the remainder of the equivalent component of the component (A) is added by various methods, or the components (A) and (B) A part can be produced by a multistage polymerization method, and the remainder of the component (B) equivalent component can be added by various methods. Further, a composition (C) can be prepared by mixing a plurality of polymers obtained by multistage polymerization containing the components (A) and (B). In any method, each of the components corresponding to the component (A) and the component (B) has a predetermined property, and the final blending ratio may be in a predetermined range.

  The catalyst is generally added before the polymerization in the first stage, but it does not necessarily exclude replenishing the catalyst in the subsequent stage, but in order to obtain characteristics that cannot be obtained by blending the resin. In this case, the catalyst is preferably added exclusively in the first stage.

In the step (1) for obtaining the component (A), propylene or propylene and a small amount of other olefin are polymerized in the presence of hydrogen. The supply of hydrogen is performed when the MFR of the polymer obtained in the step (1) is 1 to 1,000 g / 10 min. It is controlled to be in the range. In general, the hydrogen concentration (in the case of slurry polymerization, the concentration in the gas phase part, in the polymerization in liquid propylene or in the gas phase method indicates the content in the monomer) is added in an amount of 1 to 50 mol%, preferably 3 to 30 mol%.
Other olefins copolymerized with propylene can be added intermittently or can be fed continuously with propylene.
The polymerization temperature in step (1) is generally 40 to 90 ° C., and 50 to 97% by weight, preferably 60 to 95% by weight of the total polymerization amount is produced.

Step (2) for obtaining the component (B) is polymerization for obtaining a high molecular weight component, and the polymerization is allowed to proceed in a substantially hydrogen-free state with a hydrogen concentration of 0.1 mol% or less.
The MFR of the polymer obtained in the step (2) is 0.1 g / 10 min. It is as follows.
As a method for determining the MFR of component (B) at the time of multistage polymerization, a small amount is extracted in advance at the end of polymerization of component (A), and the MFR of component (A) is measured. It is calculated by the logarithmic additivity rule (Formula 3 below) from the MFRc of C) and the ratio of the components (A) and (B) in the composition (C).
log (MFRc) = {(component (A) wt%) × log (component (A) MFR) + (component (B) wt%) × log (component (B) MFR)} / 100 Formula 3)

The polymerization temperature is usually 40 to 90 ° C, preferably 50 to 80 ° C. The polymer obtained in step (2) is 3 to 50% by weight, preferably 5 to 40% by weight of the total polymer.
As a method for determining the MFR of the component (B) by other means, the weight average molecular weight of the component (B) is calculated using the GPC method, and the relational expression between the known weight average molecular weight and MFR is calculated based on this numerical value. There is a method for converting to MFR. Specifically, both the polymer obtained in step (1) and the final polymer are compared by GPC measurement of component (A) and component (C), and the difference between steps (1) and (2) From the polymerization ratio, the weight average molecular weight of the component (B) can be calculated.
Based on the data of “Polymer Handbook 4th. Ed. (John Wiley & Sons, Inc. (1999)”, the relational expression between the weight average molecular weight and MFR is, for example, log (MFR) = − 4.255 × log (Mw ) +23.27, the MFR of 0.1 g / 10 min. Or less means that the weight average molecular weight is about 506,000 or more.

3. Organic peroxide (1) basic setting The organic peroxide used in the present invention is peroxydicarbonate, which is a specific organic peroxide.
The peroxydicarbonate in the present invention is represented by the general formula R ¹ —O—CO—O—O—CO—O—R ² (where R ¹ and R ² represent a substituent composed of carbon, oxygen, and hydrogen). ) Structure.

(2) Identification of peroxydicarbonate It is known that it is efficient to use peroxydicarbonate that decomposes at a relatively low temperature in order to improve melt tension in polypropylene, that is, to cause long-chain branching. In addition, in the present invention, the half-life is 1 hour in order to efficiently perform the treatment with the organic peroxide and to suppress the generation of odor and the hue problem in the molded product due to the addition of the organic peroxide. The peroxydicarbonate having a temperature (1 hour half-life temperature) in the range of 50 to 80 ° C. is used.
Here, the upper limit of the half-life temperature is set because long chain branching can be introduced more efficiently when the relatively low temperature decomposition type is used, and the lower limit is practically dangerous if the low temperature decomposition type is more than this. It was set for a reason.

  Examples of preferred peroxydicarbonates include dicetyl peroxydicarbonate (1 hour half-life decomposition temperature 65 ° C), dimyristyl peroxydicarbonate (65 ° C), di-2-ethylhexyl peroxydicarbonate (same as above). 60 ° C), di-3-methoxybutyl peroxydicarbonate (57 ° C), bis (4-t-butylcyclohexyl) peroxydicarbonate (60 ° C), diisopropylperoxydicarbonate (61 ° C), Di-n-propyl peroxydicarbonate (at 58 ° C.), di-sec-butyl peroxydicarbonate (at 57 ° C.), di-2-ethoxyethyl peroxydicarbonate (at 59 ° C.), dimethoxybutyl peroxy Dicarbonate (64 ° C), di (3-methyl-3-methoxybutyl Such as peroxydicarbonate (the 65 ° C.) and the like.

“Polym. Eng. Sci. 44, 973 (2004)” discloses the results of using various peroxydicarbonates for the production of long-chain branches of polypropylene, according to which R ¹ and R ² are disclosed. Those having a long substituent group generate a long chain branch more efficiently. Accordingly, it is preferable to use dicetyl peroxydicarbonate among the above as peroxydicarbonate.

(3) Amount of addition In the present invention, 0.1 to 3 parts by weight of peroxydicarbonate is added to 100 parts by weight of the resin composition (C), and the melt tension is improved by melt-kneading at 160 to 270 ° C. A modified resin composition is obtained. The addition amount of peroxydicarbonate is preferably 0.3 to 2 parts by weight, more preferably 0.5 to 1.5 parts by weight.
When the amount is less than 0.1 to 3 parts by weight, the effect of improving the melt tension is small, and when it exceeds the range, the melt tension is improved, but the odor and hue are not preferable. Adding a large amount of organic peroxide is disadvantageous in terms of cost.

4). Modification Method by Melt-Kneading (1) Basic Method In order to produce the modified polypropylene resin composition (D) of the present invention, the resin composition (C) and the organic peroxide, and further necessary Accordingly, a crosslinking aid and various additives are mixed and melt-kneaded at a temperature of 160 to 270 ° C.
For mixing the organic peroxide, the crosslinking aid and various additives, a conventionally known mixer such as a ribbon blender, a tumbler mixer, a Henschel mixer, or the like can be used.

(2) Melt kneading For melt kneading, a single screw extruder, a twin screw extruder, a Banbury mixer, a roll mixer, a Brabender plastograph, a kneader, or the like can be used. From the viewpoint of productivity, it is preferable to use a single screw extruder or a twin screw extruder.
The temperature at the melt kneading is 160 to 270 ° C. If the temperature is lower than this, melt kneading cannot be performed, and if the temperature is higher than this, the reaction temperature is too high and the molecular cleavage reaction is superior to the generation of long chain branching, and the effect of modifying the melt tension becomes insufficient. Preferably it is 170-250 degreeC, More preferably, it is the range of 180-230 degreeC.

5. Compounding Agent (1) Crosslinking Auxiliary In the present invention, as the crosslinking aid, which is a compounding agent used when modifying the resin composition (C), typical examples are butadiene, isoprene and divinylbenzene. An organic compound having a plurality of unsaturated bonds in one molecule is used. More detailed examples are described in WO99 / 27007 (PTL 5).
As a general compounding amount of the crosslinking aid, the upper limit is 10 times the molar equivalent of the organic peroxide to be added.

(2) Additive In the present invention, the additive, which is a compounding agent used in combination when modifying the resin composition (C), includes the modified polyolefin resin composition ( In order to add further performance to D), various additives listed below which are generally used for polyolefin additives can be used.
Nucleating agents, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, neutralizers, light stabilizers, UV absorbers, lubricants, antistatic agents, metal deactivators, fillers, antibacterial agents Various additives such as an agent, an antifungal agent, an optical brightener, a colorant, a plasticizer, and a foaming agent can be added. In general, the amount of these additives is 0.0001 to 3 parts by weight, preferably 0.001 to 1 part by weight, based on 100 parts by weight of the resin.
In particular, the phenolic antioxidant should be added simultaneously with the addition of the organic peroxide from the viewpoint of the thermal stability during melt-kneading and the temporal stability of the modified polypropylene resin composition (D). Is preferred.

6). Characteristics in Modified Polypropylene Resin Composition (D) (1) Basic Characteristics The modified polypropylene resin composition (D) with improved melt tension obtained by the method of the present invention has a temperature of 230 ° C. -Melt flow rate (MFRd) at a load of 2.16 kg is usually 0.1 to 20 g / 10 min. It becomes. When MFRd falls within this range, it is suitable for various moldings such as blow molding, foam molding, extrusion molding, and vacuum molding.
MFRd is preferably 0.5 to 15 g / 10 min. More preferably, it is 1-10 g / 10min. Range.
In addition, the modified polypropylene resin composition (D) has a better balance of melt tension (MT) in the MFR match than the ordinary polypropylene resin or the polypropylene resin composition (C) of the present invention. Usually, the following (formula 4) is satisfied.
log (MTd)> − 0.8 × log (MFRd) +0.9 (Expression 4)

(2) Quantitative evaluation of the degree of modification with respect to the added amount of organic peroxide The basic requirement disclosed in the present invention is to modify a resin composition (C) having specific properties with a specific peroxydicarbonate. Thus, this is a technique for obtaining a modified resin composition having a sufficient melt tension with a smaller amount of organic peroxide than conventional. Thereby, it is possible to suppress the generation of odor and the problem of hue in the molded product by adding the organic peroxide.
In order to quantitatively evaluate the degree of reforming, the following (formula 5) is defined in terms of the amount of MFR and organic peroxide before and after the reforming.
{Log (MFR2) −log (MFR1)} / wPOX ≦ {0.7 × log (MFR1) −0.8}
However, when 0.1 ≦ MFR1 ≦ 10 (log (MFR2) −log (MFR1)) / wPOX ≦ −0.1
However, when 10 ≦ MFR1 ≦ 20 (Formula 5)

Considering the above formula, the MFR generally decreases by reacting an organic peroxide with a polypropylene resin to form a long chain branch. Therefore, a value obtained by subtracting the logarithm of MFR (MFR1) of the resin before modification from the logarithm of MFR (MFR2) after modification {log (MFR2) -log (MFR1)} is usually smaller than 0. The change in MFR of the amount of organic peroxide (parts by weight; wPOX) (balance) depends on the MFR of the resin before the modification, so the change in MFR per unit amount of organic peroxide (formula The right side of (Formula 5) was experimentally determined as a function of the resin before modification. That is, (Equation 5) represents the rate of change in MFR per unit amount of organic peroxide added. If the left side is lower than the right side, long chain branching is generated more efficiently and MFR is It can be understood that it decreases, that is, the reforming efficiency is high.
Since the resin composition (C) used in the present invention contains a very high molecular weight component (B), the production efficiency of long chain branching is high in proportion to the amount of organic peroxide added. The degree of improvement in melt tension when producing a post-quality polypropylene resin composition (D) is large.

7). Addition of other resin component (E) The modified polypropylene resin composition (D) can be used by itself. Moreover, you may add and use other resin (E) for the modified polypropylene resin composition (D).
For example, in the case of polyolefin, various polyethylenes, ethylene elastomers, other olefin elastomers, various α-olefin polymers having 4 or more carbon atoms, ethylene-diene monomer copolymers, acid-modified polyolefins and the like can be mentioned. Examples of resins other than polyolefin include polydiene (co) polymers, styrene elastomers, acrylic acid copolymers, methacrylic acid copolymers, ABS resins, petroleum resins, vinyl chloride resins, polycarbonates, and various ionomers. It is done.
These addition amounts are generally 1 part by weight or more and less than 100 parts by weight with respect to 100 parts by weight of the modified polypropylene resin composition (D). As a method for adding these resins, for example, mechanical kneading in a molten state using a single or twin screw extruder or a Brabender is preferably used.

In order to describe the present invention more specifically, preferred examples and comparative examples corresponding thereto are described below. These controls then demonstrate the rationality and significance of the configuration of the present invention and its superiority over the prior art.
The measuring method of various physical properties and the manufacturing method of the modified polypropylene resin in the following examples and comparative examples are as follows.

(1) Measurement method i) Melt flow rate (MFR)
According to JIS K7210 A method and condition M, it measured on condition of the following.
Test temperature: 230 ° C. Nominal load: 2.16 kg Die shape: 2.095 mm in diameter and 8.000 mm in length
ii) Melt tension (MT)
The load (g) applied at the time of taking a constant value of 4 m / min, measured under the following conditions using a Capillograph type 1C (barrel inner diameter 9.5 mm) manufactured by Toyo Seiki Seisakusho, is defined as MT.
Temperature: 230 ° C. Orifice: (L / D = 40 mm / 2 mm) Piston speed: 20 mm / min Distance from die outlet to load measurement position: 40 cm

(2) Production of Compositions 1 to 9 and Composition 11 (Resin Composition (C)) Using an Mg-supported titanium-based catalyst, various polymerization conditions were used in accordance with the method described in JP-A No. 2001-335666. The resin composition (C) comprising the component (A) and the component (B) was obtained by a multistage polymerization method. The characteristics of the components (A) and (B) and the obtained resin composition (C) are shown in Table 1. The MFR of the component (B) is calculated by the logarithmic addition rule from the MFR measurement of the component (A) extracted during the polymerization and the MFR of the composition (C). In addition, all the components (A) of these compositions are homo PP.

[Example 1]
1 part by weight of dicetyl peroxydicarbonate (trade name: Perkadox 24L, manufactured by Kayaku Akzo Co., Ltd.) with respect to 100 parts by weight of the composition 1 shown in Table 1, tetrakis {methylene-3- ( 3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate} methane (trade name: Irganox 1010, manufactured by Ciba Specialty Chemicals) 1,000 ppm was added and mixed well at room temperature. This was kneaded by a biaxial kneader having a screw diameter of 15 mm under the following conditions to obtain a modified polypropylene resin composition (D). Table 2 shows the physical properties of the modified polypropylene resin composition (D).

Extruder: KZW-15-45MG twin screw extruder manufactured by Technobel Co., Ltd. Screw: 15 mm in diameter, L / D = 45 Extruder set temperature: (from below the hopper) 60, 140, 180, 190, 190, 190 ° C. (die) Screw Number of revolutions: 300 rpm Discharge amount: Adjusted to about 1.5 kg / h with a screw feeder Die: 3 mm diameter, 2 strand die holes

[Examples 2 to 10]
The same procedure as in Example 1 was conducted except that the composition (C) used and the amount of peroxide added were changed as shown in Table 2. Table 2 shows the physical properties of the modified polypropylene resin composition (D).

[Comparative Example 1]
The same procedure as in Example 1 was carried out except that a commercially available homopolypropylene obtained by single-stage polymerization using an Mg-supported titanium-based catalyst (hereinafter referred to as composition 10) was used instead of composition (C). It was. The properties of the resin before modification are shown in Table 1, and the physical properties of the modified resin composition are shown in Table 3.

[Comparative Example 2]
It carried out similarly to the comparative example 1 except having changed the addition amount of the organic peroxide as shown in Table 3. The properties of the resin before modification are shown in Table 1, and the physical properties of the modified resin composition are shown in Table 3.

[Comparative Example 3]
Instead of the composition (C), a mixture of two commercially available homopolypropylenes having different MFRs obtained by single-stage polymerization using an Mg-supported titanium-based catalyst (this composition is referred to as composition 11). The same procedure as in Example 1 was performed except that it was used. The properties of the resin before modification are shown in Table 1, and the physical properties of the modified resin composition are shown in Table 3.

[Consideration by contrast between Example and Comparative Example]
Considering each of the above Examples and Comparative Examples in contrast, in each Example of the present invention, the specific composition ratio, the comonomer amount and the specific MFR are satisfied, and the relationship between MFR and MT. The resin composition satisfying the formula (formula (1)) is melt-kneaded by adding a specific organic peroxide, so that the melt tension is remarkably improved and the reforming efficiency per added amount of organic peroxide It is clear that there is an improvement.

Specifically, since Examples 1 to 5 and 8 (Compositions 1 to 4 and 7) include a high molecular weight component having an MFR of less than 0.1 as the component (B), the formula 1 is satisfied. , Which has a high MT-MFR balance as compared with commercially available polypropylenes such as Comparative Examples 1 and 2 (Composition 10), and is apparent as a result of the determination according to (Equation 5) in Examples 1 to 5 and 8 Thus, reforming can be achieved efficiently with a smaller amount of organic peroxide.
If attention is paid only to the MT of the modified resin, as seen in the comparison between Examples 6, 7, 9, 10 and Comparative Examples 1 and 3, the MT of the comparative example is larger. In reality, the superiority of the technology of the present invention is the efficiency of modification in proportion to the amount of peroxide added, so whether or not (Equation 5) is satisfied is a significant index. That is, in Examples 6, 7, 9, and 10, the MFR before the modification is larger than that of Comparative Examples 1 and 3, and the MFR of the resin before the modification is large, it is difficult to obtain the modification effect. The effect of obtaining the same MT with the same amount of peroxide is exhibited.

  Further, as seen in Comparative Examples 1 and 2, even when a commercially available polypropylene that does not contain a high molecular weight component (B) such as the composition 10 in a predetermined amount is modified, As is apparent, efficient melt tension improvement has not been achieved. Comparative Example 3 (Composition 11) contains the high molecular weight component (B), but its MFR is larger than 0.1, so that the MT-MFR balance of the composition 11 does not satisfy (Equation 1). As is clear from the determination of (Equation 5) in Example 3, efficient improvement of the melt tension has not been achieved.

The rationality and significance of the configuration of the present invention and the superiority over the prior art are clearly demonstrated by the comparison and discussion of the above examples and comparative examples.

Claims (6)

The following component (A) is basically composed of 50 to 97% by weight and (B) is 50 to 3% by weight (provided that the total of components (A) and (B) is 100% by weight), Peroxydicarbonate 0.1 to 3 weights with a temperature of 50 to 80 ° C. giving a half-life to 100 parts by weight of polypropylene resin composition (C) having physical properties of C-1 and C-2 A modified polypropylene resin composition (D) obtained by adding a part and melt-kneading at 160 to 270 ° C.
Component (A): Melt flow rate (MFRa) at 230 ° C. and 2.16 kg load is 1 to 1,000 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less (provided that the total of monomer units constituting the component (A) is 100% by weight)
Component (B): Melt flow rate (MFRb) at 230 ° C. and 2.16 kg load is 0.1 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 15% by weight or less (provided that the total of monomer units constituting the component (B) is 100% by weight)
C-1: MFRc of the composition (C) at 230 ° C. and 2.16 kg load is 0.1 to 20 g / 10 min.
C-2: The melt tension (MTc) at 230 ° C. of the composition (C) and MFRc at 230 ° C. and 2.16 kg load satisfy the relationship of the following formula 1 log (MTc)> − 0.9 × log ( MFRc) +0.6 (Formula 1) The modified polypropylene resin composition (D) which mix | blends another thermoplastic resin component (E) with the modified polypropylene resin composition of Claim 1. The following component (A) is basically composed of 50 to 97% by weight and (B) is 50 to 3% by weight (provided that the total of components (A) and (B) is 100% by weight), Peroxydicarbonate 0.1 to 3 weights at a temperature of 50 to 80 ° C. giving a half-life to 100 parts by weight of the polypropylene resin composition (C) having physical properties of C-1 and C-2 A method for producing a modified polypropylene-based resin composition (D), comprising adding a part and melt-kneading at 160 to 270 ° C.
Component (A): Melt flow rate (MFRa) at 230 ° C. and 2.16 kg load is 1 to 1,000 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 1% by weight or less (provided that the total of monomer units constituting the component (A) is 100% by weight)
Component (B): Melt flow rate (MFRb) at 230 ° C. and 2.16 kg load is 0.1 g / 10 min. A propylene homopolymer or a propylene copolymer having an olefin content other than propylene of 15% by weight or less (provided that the total of the monomer units constituting the component (B) is 100% by weight)
C-1: MFRc of the composition (C) at 230 ° C. and 2.16 kg load is 0.1 to 20 g / 10 min.
C-2: The melt tension (MTc) at 230 ° C. of the composition (C) and MFRc at 230 ° C. and 2.16 kg load satisfy the relationship of the following formula 1 log (MTc)> − 0.9 × log ( MFRc) +0.6 (Formula 1) 4. The modified polypropylene system according to claim 3, wherein the resin composition (C) is obtained by a multistage polymerization method in which the component (A) and the component (B) are continuously produced. The manufacturing method of a resin composition (D). The method for producing a modified polypropylene resin composition (D) according to claim 3 or 4, wherein the peroxydicarbonate is dicetyl peroxydicarbonate. A molded product obtained by molding the modified polypropylene resin composition (D) according to claim 1 or 2.