KR100330308B1 - Polypropylene resin composition having high melting tension - Google Patents

Abstract

The present invention relates to a polypropylene resin composition having a high melt tension, and more particularly, by adding an organic peroxide having a specific half-life temperature to the polypropylene can be prepared under the extrusion conditions of a general extruder and polypropylene, high melting It relates to a polypropylene resin composition having a tension.

Description

Polypropylene resin composition having high melting tension

The present invention relates to a polypropylene resin composition having a high melt tension, and more particularly, by adding an organic peroxide having a specific half-life temperature to the polypropylene can be prepared under the extrusion conditions of a general extruder and polypropylene, high melting It relates to a polypropylene resin composition having a tension.

Polypropylene resins have excellent molding processability and chemical resistance, are relatively excellent in tensile strength, flexural strength, rigidity, and the like, and are applied to various applications such as injection and extrusion. However, polypropylene has a disadvantage in that it is difficult to be applied to various molding processes such as a large vacuum / pressure molding process, a polypropylene foaming process, an extrusion coating molding process requiring high melt tension due to low melt tension.

In other words, the low melt tension of polypropylene is due to the linear chain structure. In the case of linear polypropylene, the strain hardening phenomenon is increased as the resistance of the melt increases when the polypropylene is stretched in the molten state. There is a weak point that it is difficult to apply to a variety of molding processes that require a certain amount of the melt tension is not (see Figure 1). For example, weaknesses such as cell structure instability in foam molding, sheet folding in edges in high-speed extrusion coating, sheet sag in hot press molding, and local thickness unevenness and flow instability in lamination molding Have.

On the other hand, low-density polyethylene resin has a long chain branch formed during the polymerization process, so that the chain structure has a nonlinear structure. This nonlinear structure serves as a hook when the long side chain is stretched in the molten state. By showing a very excellent melt tension and strain aging effect, due to this characteristic low density polyethylene is possible for a variety of molding methods in which the polypropylene shows a difficulty (see Fig. 1). However, in the case of low density polyethylene, the thickness of the product must be thicker than that of polypropylene in order to achieve the same rigidity as well as lower heat resistance than polypropylene. Have

Z-average molecular weight is another factor in determining the behavior at the time of stretching in such a high melt strength polypropylene material. In general, the Z-average molecular weight is often known to be related to the molding stability of the melt during melt processing. For general polypropylene resins currently in commercial production, the Z-average of 1,000,000 to 1,500,000 varies depending on the measuring device. The lower limit of the Z-average molecular weight, which is known to have a molecular weight and which can ensure melt stability, is not clearly defined, but a polypropylene having a high melt strength in which long side chains are introduced by a commercially available electron beam irradiation method. It is known to have a Z-average molecular weight of 2,000,000 or more. However, the Z-average molecular weight of 2,000,000 or more is a very difficult value to prepare with only catalyst and polymerization process techniques.

In summary, polypropylene resins with high melt strength

(1) strain aging of draw viscosity during draw behavior;

(2) high melt tension values; And

(3) It should have a Z-average molecular weight of 2,000,000 or more.

Therefore, in order to impart the above properties to polypropylene, studies have been conducted to nonlinearize the chains by binding the long side chains through appropriate decomposition and bonding reactions to the main chain of polypropylene. For example, the research that has been the most successful since the 1980s is the study of polypropylene of high melt strength with long side chains by decomposing the main chain by irradiating a certain amount of electron beams on polypropylene and combining the decomposed main chain back to the main chain. To provide propylene (US Patents 5368919, 5414027, 5541236, 5554668, 5591785, 5731362). However, this method is one of the manufacturing facilities, which requires the installation and operation costs of very expensive electron beam irradiation equipment, which has the disadvantage that the manufacturing cost of polypropylene resin increases significantly, which is one of the advantages of polypropylene, which is low cost There is a problem that you lose.

In addition, a method of introducing a long chain to polypropylene by reacting an organic peroxide with polypropylene under specific reaction conditions (US Pat. Nos. 5,416,169 and 4525257) has been developed. There is a problem that productivity is lowered by prolonging the manufacturing time due to the step by step on the batch. In addition, a method of increasing the melt tension of a polypropylene resin by blending a low density polyethylene resin having a relatively high melt tension (US Patent 4365044) has been developed, this method has the disadvantage that the heat resistance characteristics due to the degradation of the rigidity is lowered. In addition, the method of increasing the melt tension by using a crosslinking structure by crosslinking the polypropylene resin can be expected to improve the melting characteristics due to crosslinking, but molding due to the generation of gel (fish, eye-eye) in the molded product by crosslinking. There is a problem in that the poor value of the product as a film or fiber is very poor.

Therefore, the present inventors have conducted a study to solve the above problems, as a result of using the organic peroxide having a specific half-life temperature in the limited polypropylene type, there is no gel even in the extrusion conditions of the general extruder and polypropylene, high melt tension The present invention has been completed by knowing that a polypropylene resin having a strain thickening characteristic and a Z-weight average molecular weight of 2,000,000 or more in terms of over-stretch viscosity and excellent productivity and low manufacturing cost can be produced.

Accordingly, it is an object of the present invention to provide a polypropylene resin having a high melt tension.

The above and other objects of the present invention will become apparent to those skilled in the art from the construction and function of the following invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the change of general draw viscosity at the time of extending | stretching behavior in the polymeric material of the nonlinear structure which has a linear structure and long side chain.

2 is a graph showing melt tension values measured in Examples and Comparative Examples.

3 is a diagram showing the stretching behavior according to the stretching time measured in Examples and Comparative Examples.

In order to achieve the said objective, the polypropylene resin composition of this invention contains 0.01-2.0 weight part of following (B) components with respect to 100 weight part of following (A) components, It is characterized by the above-mentioned.

(A) A propylene homopolymer or a binary copolymer of propylene and 10 mol% or less of a C2-C10 alpha -olefin monomer, which satisfies the following conditions ① to ②:

① The weight average molecular weight is 300,000 g / mol or more

② Melt Index 0.1 ~ 3g / 10min (230 ℃)

(B) an organic peroxide having a half-life temperature of 80 ° C. or less based on a 10-hour half-life temperature.

Moreover, it is further characterized by containing the following (C) component in the quantity of 99 weight part or less with respect to 100 weight part of said (A) resin components.

(C) a binary copolymer of propylene with an α-olefin monomer having 2 to 10 carbon atoms, satisfying the following conditions ① to ②:

① The content of α-olefin monomer having 2 to 10 carbon atoms is 11 to 40 mol%

② Melt index 0.5 ~ 60g / 10min (230 ℃).

Each component is demonstrated concretely below.

In the polypropylene resin composition of the present invention, component (A) is a high molecular weight polypropylene in which decomposition and bonding reactions occur mainly, and the content of α-olefin having 2 to 10 carbon atoms is 0 to 10 mol%, and the melt index is 0.1 to It is 3 g / 10min (230 degreeC), and a weight average molecular weight is 300,000 g / mol or more, Preferably the weight average molecular weight is 500,000 g / mol or more. Although the kind of the C2-C10 alpha-olefin polymerized with propylene is not specifically limited, For example, butene-1, ethylene, 4-methyl- pentene-1, hexene-1, octene etc. are mentioned.

Component (B) is an organic peroxide that serves as a reaction initiator, and has an organic peroxide having a half-life temperature of 80 ° C. or lower, preferably 60 ° C. or lower for 10 hours. Diisobutyryl peroxide, t-amyl peroxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate [Di (4-tert-butylcyclohexyl) ) peroxy dicarbonate], di-2-ethylhexyl peroxydicarbonate, dibutyl peroxydicarbonate, di-isopropyl peroxydicarbonate, dicetyl peroxydicarbonate, Dimyristyl peroxy dicarbonate t-butyl peroxy neoheptanoate, t-amyl peroxy pivalate, t-butyl peroxy pivalate, t-butyl peroxy pivalate, dilauroyl peroxide, didecano Yl peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl Peroxy-2-ethylhexanoate, dibenzoyl peroxide, t-butyl peroxy-2-ethylhexano Acetate, t-butylperoxydiethyl acetate, t-butylperoxyisobutyrate, 1,4-di (t-butylperoxycarbo) cyclohexane, and the like.

In addition, the resin composition of the present invention has a high content of α-olefins having 2 to 10 carbon atoms in addition to the components (A) and (B), thereby reducing decomposition in the α-olefin region, and also causing a small amount of long-chain chain reaction to occur. C) It may further contain a component. (C) component has 11-40 mol% of C2-C10 alpha olefins, Preferably it is 15-40 mol%, and melt index is 0.5-60g / 10min (230 degreeC).

Hereinafter, the present invention will be described in more detail with reference to various examples.

First, the characteristic evaluation method of the various compositions used for the following Example and the comparative example is demonstrated.

(1) Melt Index:

It measured by ASTM D-1238 at 230 degreeC and 2.16 kgf.

(2) Melt tension value:

Measurements were made using a Leotens 71.97 instrument from Goeffert, Germany. The measurement method was measured by inserting a resin in a Brabender uniaxial extruder of Brabender, Germany, extruded at 200 ℃, 50RPM and mounting a rhetens under the die. Leotens is equipped with four wheels for stretching the resin, and the stretching speed is accelerated at the same rate. The measured value is shown in FIG. 2 as centinewton (cN).

(3) Elongation Viscosity:

It measured using the Melten rheometer of the Toyo Seiki Corporation of Japan. In the method, the sample was first extruded in an extruder, and five specimens having a length of 20 cm were taken and allowed to stand in an oil bath containing silicon oil at 180 ° C. for 10 minutes, and then the strain viscosity was measured at 0.05 sec ⁻¹ .

(4) Z-average molecular weight (Mz):

Z-average molecular weights were measured using Gel Chromatography (GPC) 150C from Waters, USA.

[Examples 1-3]

Polypropylene resin having a melt index of 0.5 g / 10 min (230 ° C., 2.16 kg) as a component (A), a weight average molecular weight of 500,000 g / mol, and an ethylene content of 6 mol%: dibenzoyl peroxide as (B) component The resin composition added in the amount shown in Table 1 was mixed by a Henschel mixer for 3 minutes. After the mixture was extruded by a twin-screw extruder at a temperature range of 190 ~ 250 ^o C, it cooled, and solidified to obtain a composition on the pellets. Physical properties of the obtained composition were measured by the above method, and the results are shown in Table 1 and FIG. 2. On the other hand, the drawing viscosity is measured in the Brabender equipped with a single screw in a cylindrical specimen (about 20cm in length) in the temperature range of 180-220 ℃, the drawing viscosity of Example 3 is shown in FIG.

Example 4

In Example 1 (A) and (B), an ethylene-propylene copolymer having an ethylene content of 38% as a component (C) and a melt index of 1 g / 10 min (230 ° C., 2.16 kg) is shown in Table 1 below. It was added in the amount described and the pellet composition was obtained by the same method as Example 1. Physical properties of the obtained composition were measured by the above method, and the results are shown in Table 1 and FIG. 2.

EXAMPLES 5-7

A pellet-like composition was obtained in the same manner except that di-isopropyl peroxy dicarbonate was added in the amount shown in Table 1 instead of the component (B) of Example 1. The physical properties of the obtained composition were measured by the above method, and the results are shown in Table 1. In addition, the extending | stretching viscosity of Example 5 measured by the method similar to Example 3 is shown in FIG.

Comparative Example 1

Component (A) of Example 1, i.e., polypropylene resin having a melt index of 0.5 g / 10 min (230 DEG C, 2.16 kg), a weight average molecular weight of 500,000 g / mol, and an ethylene content of 6 mol% It carried out by the same method and obtained the composition of a pellet form. The physical properties of the obtained composition were measured by the method described above, and the results of measuring the physical properties are shown in Tables 1, 2 and 3.

[Comparative Examples 2 ~ 3]

0.4 parts by weight of t-butyl peroxy isopropyl carbonate and bis (t-butylperoxy isopropyl) benzene were mixed with the component (A) of Example 1, instead of the component (B), in the same manner as in Example 1 After obtaining the composition of the phase, the physical properties were measured by the method described above, and the results of the physical properties are shown in Table 1 and FIG.

[Comparative Example 4]

Example (A) of Example 1 was mixed (15%) of LDPE for extrusion coating, which is a low density polyethylene resin having a melt index of 5 g / 10 minutes (190 ° C., 2.16 kg) and a density of 0.910 g / cm ³ . After obtaining a pellet-like composition by the same method as 1, the physical property was measured by the above-mentioned method, and the measurement result of the physical property is shown in Table 1 and FIG.

[Comparative Example 5]

The physical properties of the high melt strength polypropylene (Montel Co., Ltd .: PF-814) prepared by the electron beam irradiation method were measured by the above method, and the results of the measurement of the physical properties are shown in Table 1, FIG. 2 and FIG. 3.

Parts by weight Parts by weight Parts by weight Melt Index (g / min) Z-Average Molecular Weight (Mz) A C B-1 B-2 B-3 B-4 LDPE Example One 100 0.2 0.55 1,923,400 2 100 0.4 0.52 2,005,600 3 100 0.6 0.45 2,177,800 4 90 10 0.4 0.43 2,104,300 5 100 0.2 0.50 2,044,700 6 100 0.4 0.45 2,108,300 7 100 0.6 0.30 2,258,200 Comparative example One 100 0.58 1,297,400 2 100 0.4 18 589,243 3 100 0.4 72 211,230 4 85 15 0.7 1,327,400 5 100 3.0 2,520,000

Polypropylene resin composition having a high melt tension according to the present invention is not only excellent mechanical properties but low melt tension to advance to the area where the polypropylene is not used, as well as the overall thickness of the product due to the excellent rigidity of polypropylene The economical efficiency is excellent because

Claims (3)

0.01-2.0 weight part of following (B) components with respect to 100 weight part of following (A) components, The polypropylene resin composition which has high melt tension characterized by the above-mentioned. (A) A propylene homopolymer or a binary copolymer of propylene and 10 mol% or less of a C2-C10 alpha -olefin monomer, which satisfies the following conditions ① to ②: ① The weight average molecular weight is 300,000 g / mol or more ② Melt Index 0.1 ~ 3g / 10min (230 ℃) (B) an organic peroxide having a half-life temperature of 80 ° C. or less based on a 10-hour half-life temperature. The resin composition according to claim 1, further comprising (C) component in an amount of 99 parts by weight or less based on 100 parts by weight of the component (A); (C) a binary copolymer of propylene with an α-olefin monomer having 2 to 10 carbon atoms, satisfying the following conditions ① to ②: ① The content of α-olefin monomer having 2 to 10 carbon atoms is 11 to 40 mol% ② Melt index 0.5 ~ 60g / 10min (230 ℃) The organic peroxide as the component (B) according to claim 1 is diisobutyryl peroxide, t-amyl peroxyneodecanoate, di (4-t-butylcyclo Hexyl) peroxydicarbonate [Di (4-tert-butylcyclohexyl) peroxy dicarbonate], di-2-ethylhexyl peroxydicarbonate, dibutyl peroxydicarbonate, di-isopropylperoxydicarbonate, dicetyl peroxydicarbonate ], Dimyristyl peroxy dicarbonate, t-butyl peroxy neoheptanoate, t-amyl peroxy pivalate, t-butyl percarbonate Oxypibarate, dilauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutyl Peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, diben In yl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butylperoxydiethyl acetate, t-butylperoxyisobutyrate, 1,4-di (t-butylperoxycarbo) cyclohexane Polypropylene resin composition, characterized in that selected.