KR20140058748A - Method for producing peroxide masterbatch composition and reforming polypropylene using thereof - Google Patents

Abstract

The present invention relates to a technology for producing peroxide masterbatches and to a method for reforming polypropylene using the same. According to the present invention, a masterbatch composition is provided which allows for easy reforming so as to exhibit melting characteristics desired by an end user, and which enables a safer and more reliable reforming of polypropylene. A method for reforming polypropylene using the composition is also provided.

Description

TECHNICAL FIELD The present invention relates to a peroxide masterbatch production technology and a polypropylene reforming method using the peroxide masterbatch composition and reforming polypropylene using thereof,

The present invention relates to a peroxide master batch production technique and a polypropylene reforming method using the same.

Polypropylene is a relatively recently developed high quality resin that has been in production since the late 1950s and occupies an important position among the various resins developed to date. Demand for polypropylene has been on the rise ever since. Propylene, a monomer of polypropylene, is produced with ethylene in the decomposition of naphtha in petrochemical plants. It is easily synthesized by making a chitin catalyst (typically a complex salt of titanium trichloride and diethyl aluminum chloride) in a nucleic acid, and passing propylene through it at about 70 ° C and 5 atm. Has an isotactic structure, and therefore the methyl groups are aligned in the same direction as the structural formula. The melting point is 165 and continuous use under load (load) is possible at 110. The density is 0.9 to 0.91, and the degree of crystallinity is large, but after molding, it drops to 70% or less. Its electrical properties are excellent because it consists of only carbon and hydrogen, and it is comparable to polyethylene. Polypropylene is one of the four generic resins together with polyethylene, PVC, and polystyrene, and the weight of the thermoplastic resin is 24%. It is also advantageous in terms of cost and environment. Applications include packaging films, stretching tapes, textiles, clothing, carpets, pipes, daily necessities, toys, industrial parts, and containers. Peroxide is often used in the production of polypropylene. Modification of the polymer chain into peroxides improves the melting properties of the polypropylene. Peroxides can lower the viscosity of the polymer and control the melt properties during the process. This means that through selective chain cleavage, a narrower molecular weight distribution, molecular weight, and lower melting point can be achieved. These properties are indicated by the Melt Flow Index (MFI). This index represents the amount of polypropylene discharged per unit time (10 minutes) through a nozzle having a specific diameter of a specific temperature condition. However, if the melt index (MFR) required for radiation extrusion of polypropylene is not satisfied, a screen clogging phenomenon may occur due to an increase in the pressure of the spinning extruder. In addition, when various grades according to MFR0 are produced after the PP polymerization production, if they react with hydrocarbons, which are leftover catalyst remaining unreacted during extrusion processing, there is a risk of explosion at a temperature of 80 degrees or higher MASTER BATCH is used for the purpose of avoiding such a danger in the summer season. Polypropylene has a characteristic that the melt tension is rapidly lowered from the melting point due to the weak melt strength due to the linear chain structure, It is difficult to form a fine cell due to breakage in the wall, resulting in lower expansion ratio and compressive strength, resulting in deterioration of mechanical properties, and therefore, unsatisfactory moldability can not be obtained compared with other plastic compositions. Modification of polypropylene which is easy to modify so that it can be represented and safer and more reliable This law is required.

Korean Published Patent 2009-0135247

Under the above-mentioned technical background, the present inventors have made intensive efforts to accomplish the present invention. Accordingly, it is an object of the present invention to provide a master batch composition for modifying polypropylene which is easy to modify so that end users can exhibit a desired melting characteristic, and safer and more reliable. It is another object of the present invention to provide a process for modifying polypropylene using the masterbatch composition.

According to one aspect of the present invention, there is provided a composition comprising: A) from 70% to 99% by weight of a polypropylene component; B) 1% to 20% by weight of 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane; And C) 0.1% to 10% by weight of an additive may be provided.

In one embodiment, the polypropylene may be at least one selected from the group consisting of propylene homopolymers, random copolymers, and terpolymers.

In one embodiment, the additive may be a phosphate based antioxidant.

According to another aspect of the present invention, there is provided a process for producing a polyurethane foam, comprising the steps of: injecting components A), B) and C) into an extruder; Heating and extruding at 100 to 200 ° C to prepare a master batch with granules or pellets; And a step of mixing and heating the polypropylene and the extruded master batch to crosslink them, may be provided.

In one embodiment, the modification may be to change the melt index (MFR) of the polypropylene within the range of 12 to 1800 to vary the physical properties of the polypropylene within the error range of the target MI of 1 to 5 wt% .

According to the present invention, it is possible to provide a master batch composition for modification of polypropylene which is easy to modify and safer and more reliable so that end users can exhibit the desired melting characteristics. The master batch according to the present invention has a physical form in the form of a solid pellet, which can improve storage stability and dispersibility during processing, as well as improve product performance and free from fire and explosion when the external temperature rises at a high temperature. According to the present invention, a method for modifying polypropylene using the same can be provided.

1 is a modification of the conventional polypropylene reforming process (above) and modification of the polypropylene using the master batch composition according to the present invention (below).
2 is a graph showing the MI change of polypropylene produced according to one embodiment of the present invention.
3 is a graph showing the molecular weight distribution of polypropylene prepared according to one embodiment of the present invention.
4 is a graph showing the molecular weight distribution of polypropylene prepared according to one embodiment of the present invention.
5 is a graph showing the molecular weight distribution of polypropylene prepared according to one embodiment of the present invention.
6 is an electron micrograph of a polypropylene nonwoven fabric produced according to one embodiment of the present invention and a comparative example.

Hereinafter, the present invention will be described in more detail.

The terms used above and hereinafter may be defined as follows:

The term "master batch" refers to a product obtained by mixing a compounding agent with a compounding agent at a higher concentration than the prescription in the step of mixing the compounding agent with the raw rubber. The compounding agent can be incorporated into the rubber to accurately meter each compounding agent, And it is possible to prevent scattering during operation. Means a material used for improving the dispersion of the pigment during plastic molding processing. The term "extruder" is used to refer to extruding and molding extruded rubber or synthetic resin tubing, rod members of various cross-sectional shapes, plate members, shape members, Machine. A part of the raw material supplied to the feeding zone through the rotation of the screw is started to be broken due to friction and impact and starts to be melted by the frictional heat and the heating heat at this time The molten resin is completely melted by reaching the melting zone, and the resin having a uniform viscosity is extruded from the mixing zone. Polypropylene has good oil resistance and excellent heat resistance up to 100 ℃. Especially, because it has excellent mechanical properties, secondary molding and recycling are possible, it is used in wide range of automobile, electric and electronic parts. However, since the polypropylene has a characteristic that the melt tension is rapidly lowered from the point of melting due to the weak melt strength due to the linear chain structure, breakage occurs in the cell wall at the time of foaming and formation of the fine cells is difficult, The compressive strength is lowered and the mechanical properties are lowered, so that satisfactory moldability is not obtained compared with other plastic compositions.

For this reason, various methods for increasing the melt strength of polypropylene have been proposed. First, by irradiating the polyolefin with an electron beam to introduce a long chain branch, the attraction between the polymer chains in the processing step is reduced, In applications requiring easy flow characteristics and requiring dimensional stability, such as large blowing, long side branches increase the melt strength through physical bridging with the adjacent chains, resulting in high melt tension A method of using the above method has been used. As a method of producing a polypropylene having a high melt strength by introducing such a long side branch, radicals are formed mainly on a polypropylene through a polymerization reactor through an electron beam or a reaction extrusion method, Was used. Secondly, there is a method of physically blending polypropylene having a very high molecular weight. In this case, there is a problem that the melt index is very low and the processability is degraded. In addition, both of the two methods have a disadvantage in that the polypropylene is polymerized by polymerization, and then the functionalities are imparted through post-processing such as electron beam crosslinking and blending, resulting in high manufacturing cost and difficult commercialization.

Referring to FIG. 1 of the present invention, a schematic diagram of a conventional polypropylene reforming process (above) and a reforming process of polypropylene using the master batch composition according to the present invention (below) are shown.

The conventional method shows that a polypropylene having a desired MI (melt index) is prepared in advance and put into an extruder.

Alternatively, the modification of the polypropylene according to the present invention can be accomplished by mixing the polypropylene with the master batch composition and introducing the mixture into a desired MI during the extrusion process.

According to one aspect of the present invention, there is provided a composition comprising: A) from 70% to 99% by weight of a polypropylene component; B) 1% to 20% by weight of 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane; And C) 0.1% to 10% by weight of an additive may be provided.

At this time, the additive may be a UV stabilizer, a pigment, a flame retardant, an antistatic agent and the like within an appropriate range that does not impair the effect of the present invention.

The use of the masterbatch composition according to the invention provides: 1) good processability and dispersibility; 2) reduced manufacturing costs of meltblown nonwoven and SM (M) S composites; 3) Final MFI (12 ~ 1800 range: target value can be changed according to user's requirement); 4) High safety - Explosion and fire prevention of petrochemical plant (the explosion fire incident occurred in PP polymerization plant of petrochemical complex in Yeosu Daesan Ulsan for 20 years) is as follows.

The technical feature of the present invention is that the DTBPH peroxide 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane does not react with propylene in the masterbatch manufacturing process and the end user does not react with the final polypropylene product The master batch according to the present invention is added to the process and mixed with propylene to cause a control rheological phenomenon, and the main chain is boiled due to the chain vis-breaking phenomenon, so that the MFI (or MFR) . In addition, in the case of polyethylene (PE) and EVA (EVA), graft (cross-linking) reaction opposite to PP proceeds and is also used in the production of adhesive resin (TIE RESIN). Thus, the masterbatch composition according to the invention can be used to easily adjust the melt index of polyethylene or polypropylene in the range of 12 to 1800 MFI. So that polypropylene having a high melt index can be manufactured with high reliability so that an end user can more easily inject polypropylene. Thus, the use of the masterbatch composition according to the invention makes polypropylene very easy to process. When using the master batch according to the present invention, it is possible to secure high safety in the production of polypropylene. If the unreacted catalyst reacts with hydrocarbons, there is a risk of explosion at temperatures above 80 degrees Celsius. However, the masterbatch according to the present invention does not leave unreacted peroxides which are not participating in the crosslinking reaction, so there is no risk of side reaction with the hydrocarbon and explosion.

In addition, when the melt index (MFR) required for spinning of polypropylene can not be met, a screen clogging phenomenon may occur due to an increase in the pressure of the spinning extruder. Therefore, the above- It also results in securing.

According to one embodiment, the polypropylene may be at least one selected from the group consisting of propylene homopolymers, random copolymers and terpolymers. According to one embodiment, the additive may be a phosphate based antioxidant. The phosphate-based antioxidant may be ALKANOX, ULTRANOX, WESTON, POLYGARD, SONGNOX or the like, but is not limited thereto.

According to another aspect of the present invention, there can be provided a peroxide masterbatch production method and a reforming method of polypropylene, comprising the following steps.

A) from 70% to 99% by weight of a polypropylene component; B) 1% to 20% by weight of 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane; And C) 0.1% to 10% by weight of additives

Injecting components A), B) and C) into an extruder; Heating and extruding at 100 to 200 ° C to form granules or pellets to prepare a master batch; And mixing and heating the polypropylene and the extruded master batch to crosslink them.

In one embodiment, the modification may be to change the melt index (MFR) of the polypropylene to within the range of 1 to 5% of the target MI within a range of 12 to 1800.

A feature of the present invention is that the end user can very easily extrude a polypropylene resin having a melt index in a wide range as desired. Particularly, when using the master batch, it is possible to obtain a resin of very uniform quality and to secure a highly reliable resin having an MI range of 1 to 5%. These advantages are well illustrated in the following examples.

 Preparation of Masterbatches: Preparation Examples 1 to 4:

As shown in Table 1 below, polypropylene; 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane; And a phosphate-based antioxidant ALKANOX (OR SONGNOX 168) were put into an extruder. Thereafter, the mixture was heated and extruded at 100 to 200 DEG C and molded into granules or pellets to prepare a master batch (MB).

(Unit: wt%) Production Example 1 Production Example 2 Production Example 3 Production Example 4 Polypropylene 97.5 94 89.5 79.5 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane 2 5.5 10 20 Phosphate-based antioxidant 0.5 0.5 0.5 0.5

Modification and characterization of polypropylene

Example 1

A mast batch (referred to as peroxides MB in the following table) prepared in the same manner as in Preparation Example 2 was used for the polypropylene modification. The properties of the polypropylene according to the content of the masterbatch according to the invention were determined as follows.

Melt Index
(g / 10 min) Number average molecular weight Weight average molecular weight Polydispersity (P.I) Base polypropylene (1st generation) 150 15700 82900 5.28 Peroxid MB 5.5% concentration (wt%) 0 192 12600 74200 5.89 1.0 473 12200 55400 4.54 1.5 669 8250 49300 5.98 2.0 786 8150 46200 5.67 2.5 1002 7540 42200 5.60 3.0 1120 7620 41300 5.42 3.5 1355 7580 39900 5.26

At this time, the melt index MFI and the molecular weight distribution (MWD) were measured at 285 DEG C (geotfert single, L / D = 25 F / F screw)

MFI data were measured with 1 mm orifice MFI and converted to 2.095 mm MFI. (1 mM MFI * 19.6 + k)

As shown in Table 2, when the master batch according to the present invention is added while increasing the concentration of peroxides, the melt index is also linearly increased, i.e., linearly increasing. These results are shown in FIG. 2 as a graph (see the graph with MI = 130).

3 shows a molecular weight distribution curve obtained by measuring the molecular weight distribution by the concentration of peroxide. Referring to the graph of FIG. 3, it can be seen that the molecular weight distribution of the polypropylene according to the present invention is uniformly formed in a very narrow section.

Since the increase in peroxidic concentration and the increase in MI due to increased master batches indicate a pattern that maintains a linearity, the end user using it can predict the final MI of the polypropylene and therefore, without failure of the process There is an advantage that desired polypropylene can be easily obtained. In addition, a reliable polypropylene having a narrow molecular weight distribution can be produced.

Example 2

The properties of the polypropylene were measured in the same manner as in Example 1.

Melt Index
(g / 10 min) Number average molecular weight Weight average molecular weight Polydispersity (P.I) Base polypropylene (1st generation) 165 10300 78300 7.60 Peroxid MB 5.5% concentration (wt%) 0 200 8560 73800 8.62 1.0 568 7320 50100 6.84 1.5 724 9010 49500 5.49 2.0 997 9610 43300 4.51 2.5 1134 6890 38200 5.54 3.0 1426 6800 39100 5.75 3.5 1699 6640 34300 5.17

As shown in Table 3, when the masterbatch according to the present invention is added while increasing the concentration of peroxides, the melt index according to the present invention increases linearly, i.e., linearly. Referring to FIG. 4, it can be seen that the molecular weight distribution of the polypropylene according to the present invention is uniformly formed in a very narrow section.

Example 3

Melt Index
(g / 10 min) Number average molecular weight Weight average molecular weight Polydispersity (P.I) Base polypropylene (1st generation) 193 10200 73800 7.24 Peroxid MB 5.5% concentration (wt%) 0 216 10200 71200 6.98 1.0 610 9050 51100 5.65 1.5 884 8120 39600 4.88 2.0 1080 7530 41600 5.52 2.5 1237 8210 40200 4.90 3.0 1531 7080 38000 5.37 3.5 1962 7840 35900 4.58

As shown in Table 4, when the masterbatch according to the present invention is added while increasing the concentration of peroxides, the melt index according to the present invention increases linearly, i.e., linearly. Referring to FIG. 5, it can be seen that the molecular weight distribution of the polypropylene according to the present invention is uniformly formed in a very narrow section.

Example 4

Polypropylene having a melt index (MI) of about 34 to 38 g / 10 min and 1.0 wt% of "IRGATEC CR76 " Further, 6 parts by weight of a master batch containing phthalocyanine blue, which is a pigment, was added to an extruder having a heating part of 5 ea, and the temperature of the feed parts as the initial two areas was set to 265 DEG C and the temperature of the other molten part and kneading part was set to 295 DEG C Fiber spun at 1 wt% of the weight of the nonwoven fabric and laminated on a porous conveyor belt to obtain a spunbond nonwoven fabric having a five-layer structure of long-span SSMMS with a combination of spunbond and meltblown having a basis weight of 50 gsm /.

Example 5

In the same manner as in Example 4, 1.2 wt% of "IRGATEC CR76" manufactured by Shiba Co., Ltd. was added and melt-spun to 10 wt% of the weight of the nonwoven fabric to obtain a long-spun spunbond nonwoven fabric.

Example 6

In the same manner as in Example 5, 1.5 wt% of "IRGATEC CR76" manufactured by Shiba Chemical Co., Ltd. was added and melt-spun to 10 wt% of the weight of the nonwoven fabric to obtain a long-spun spunbond nonwoven fabric.

Comparative Example 1

6 wt% of a masterbatch having a high concentration of polypropylene having a melt index (MI) of about 900 1100 g / 10 min and a pigment phthalocyanine blue was charged into an extruder having a heating portion of 5 ea, and the temperature of the initial two feeding portions was 180 ° C., The temperature of the part and the kneading part was set at 285 캜 and melt-spinned to 10 wt% of the weight of the nonwoven fabric, and the resultant was made into a fiber and laminated on a porous conveyor belt to form a five layer of SSMMS with a combination of spunbond and meltblown having a basis weight of 50 gsm / Structure spunbonded nonwoven fabric. 6 shows electron micrographs of the meltblown polypropylene nonwoven fabric (upper side) produced according to Example 4 of the present invention and the nonwoven fabric prepared according to Comparative Example 1. Referring to this, it can be seen that the fiber structure of the nonwoven fabric according to the present invention is cleaner and exhibits excellent surface characteristics. The melt index of the polypropylene can be increased by using the master batch according to the present invention. The present invention can realize the increase of the melt index to the same extent as uniformity in the polypropylene resin without any danger such as explosion.

As a result, according to the present invention, there can be provided a master batch composition for modifying a polypropylene which is easy to modify so that an end user can exhibit desired melting characteristics, safer and reliable, and a method for modifying polypropylene using the same.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do.

Claims (5)

Masterbatch composition (wt%) comprising the following components:
A) from 70% to 99% by weight of a polypropylene component;
B) 1% to 20% by weight of 2,5-dimethyl 2,5-di (tert-butylperoxy) hexane; And
C) 0.1% to 10% by weight of an additive. The masterbatch composition according to claim 1, wherein the polypropylene is at least one selected from the group consisting of a propylene homopolymer, a random copolymer and a terpolymer. The masterbatch composition of claim 1, wherein the additive is a phosphate based antioxidant. A process for modifying polypropylene comprising the steps of:
(A), (B) and (C) into an extruder;
Heating and extruding at 100 to 200 DEG C to prepare a master batch with granules or pellets; And
Mixing and heating the polypropylene and the extruded master batch to crosslink them. 5. The polypropylene according to claim 4, wherein the modification is to change the physical properties of the polypropylene to within a range of 1 to 5% by weight of the target MI in the range of 12 to 1800 in melt index (MFR) Modification method of propylene.

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