JPS5936149A - Manufacture of highly impact-resistant polypropylene composition - Google Patents

Abstract

PURPOSE:To obtain titled composition in a simple way, by blending, under specific condition in a high-speed mixer a combination of a polypropylene resin and talc of specific particle size. CONSTITUTION:(A) a polypropylene resin such as propylene homopolymer, propylene-ethylene block copolymer with an ethylene content of 1-30wt%, etc. and (B) 10-50wt% based on the whole composition, of talc with an average particle size of 5-20mu are blended in a high-speed mixer at a revolution of 1,000- 3,000rpm for >=10min (normally, <30min) with the temperature of the content of 100-150 deg.C thus obtaining the objective composition. Said polypropylene resin may be either of powder or pellet form; however, for the effective grinding of the talc in a short time, combination of both forms being preferable; in particular, it is recommended that the powdered form account for 40-60wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making high impact polypropylene compositions. More specifically, the present invention relates to a method for producing the composition, which comprises mixing talc of a specific particle size and a polypropylene resin in a high-speed mixer under certain conditions.

A method is known for improving the rigidity, dimensional stability, flame retardance, heat resistance, printability, paintability, etc. of a composition obtained by mixing talc, which is a type of inorganic optical fiber, with polypropylene. Among these physical properties, -'l:j4 in rigidity
! In order to improve impact resistance, there is a method of blending talc into polypropylene by adjusting the particle size distribution of the talc used. For example, JP-A-56-928
No. 56 or No. 54-39456 uses ultrafine talc particles of 1 micron or less, but it is difficult to manufacture such fine powder talc, and a composition in which it is blended with polypropylene warps. Molding defects are likely to occur. A glimpse,
There is also the idea of limiting not only the particle size of talc but also its shape, that is, its aspect ratio (4?, Kaikai 54-1079
No. 48, but vinyl chloride resin composition). However, in this case, a decrease in melt fluidity during processing is likely to occur. Furthermore, a method is known in which not only the particle size of talc is set to 0.5 to 10 μm, but also other soft resin components are used in combination (Japanese Patent Application Laid-open No. 55-34271), but this method warps and reduces rigidity. It may decrease. JP-A No. 57-8235 was recently introduced as a technique that solved the problems of the prior art to the degree of a monk. This invention attempts to overcome the drawbacks of the prior art by regulating the particle size distribution of the talc used in three stages, that is, in three particle size ranges. limited to copolymers, and
Furthermore, since the particle size distribution of the talc used is limited to relatively narrow ranges of 10 microns or less, 5 microns or less, and 1 micron, it is not economical to prepare such talc only by pulverization.

In view of the above-mentioned drawbacks of the prior art, the present inventors have arrived at a method for producing a polypropylene composition with particularly improved impact resistance using commonly used talc (powder) and homopolypropylene resin. I researched as much as possible. As a result, talc with an average particle size of 5μ to 20μ and homopolyzolopyrene l1f
l! The present invention was constructed based on the knowledge that the above manufacturing method can be realized by mixing (powder or pellets) under certain conditions with a high-speed mixer.

As is clear from the above description, an object of the present invention is to provide a simple method for producing a highly impact-resistant polypropylene resin composition using a talc blend.

The present invention has the following configurations (1) and (2).

(1) 10 to 50% by weight of talc with an average particle size of 5 μ to 20 μ to the entire composition is mixed with polypropylene resin, mixed for 10 minutes or more in a high-speed mixer, heated, and mixed. 1. A method for producing a high impact resistant polypropylene composition, which comprises raising the maximum temperature of the composition to 150° C. or more, ioo° C. or higher.

(2) Item (1) above, wherein the polypropylene resin is a propylene homopolymer or a nopropylene-ethylene block copolymer with an ethylene content of 1 to 30 units (fc)
Manufacturing method described in Section.

(3) The manufacturing method according to item (1) above, in which polypropylene powder and polypropylene pellets are used in combination as the polypropylene resin.

The talc used in the present invention is a powder with an average particle size of 5 to 20 microns, typically 10 microns. Talc or hydrated magnesium silicate has the structural formula (OH)sMg+28i+5o-
It is a crystalline mineral with a remarkable layered structure, and it is known that its aspect ratio becomes thicker when it is finely pulverized. However, in the present invention, talc is mixed with polypropylene resin (powder and/or pellets) in a high-speed mixer without being pulverized. The amount used is 10 to 50% by weight, based on the high impact polypropylene composition according to the invention. If the amount is less than 10% by weight (hereinafter all references mean % by weight), pulverization in the high-speed mixer according to the method of the present invention will be practically insufficient, so that the resulting composition will not have sufficient impact resistance. is not obtained. Furthermore, if the number exceeds 50 inches, the pulverization becomes insufficient and the same result occurs.

The polypropylene resin used in the present invention is not only a propylene homopolymer but also a crystal [i combination] of propylene and other α-olefins, such as ethylene, and has an ethylene content of 1
You can also use ~roochi. As for the ethylene propylene copolymer, a block copolymer is easier to use than a random copolymer, and excellent results can be obtained.

The form of the polypropylene resin can be either powder or pellets, but in order to effectively grind the talc in a short time by mixing the raw materials for the composition of the present invention in a high-speed mixer, it is usually a combination of powder and pellets. Combination use is recommended. The ratio of combined use varies depending on the mixing ratio of talc and polypropylene resin and the type of talc (powder) (place of origin and particle size), but the ratio of powder/(Konaji Beret) is 20 to 80.
It is preferably 40 to 60%.

The mixing of talc and polypropylene resin in the present invention is carried out as follows. That is, both the raw materials in a predetermined amount and in a predetermined ratio are charged into a high-speed mixer at one time or in several batches. A high-speed mixer is a device that uses high-speed mechanical stirring of powder or granular raw materials and has the ability to adjust the internal temperature within a certain temperature range (for example, room temperature to 150°C). ) is also one of them. If there is a risk that the content may rise in temperature due to frictional heat due to strong stirring and cause fusion thermal decomposition, etc., the temperature of the content can be maintained within a certain temperature range by cooling the jacket part. .

The mixing conditions for the composition raw materials according to the present invention in a high-speed mixer are as follows: The temperature of the contents is 100 to 150°C, and the stirring time is 10°C.
It is usually within 30 minutes.

The rotation speed of the stirrer varies depending on the specifications of each mixer, but it is 700 to 700. ! +50Orpm 'IH or 1oo
o −3ooo rpm. If the above-mentioned mixing temperature is less than 100 ° C. or the above-mentioned stirring time is less than 10 minutes, the degree of grinding of Merck in the composition is likely to be insufficient,
Favorable physical properties of the composition cannot be obtained. On the other hand, if the temperature is 1
If the temperature exceeds 50°C, local fusion of the polypropylene resin occurs and warping occurs, reducing the talc crushing effect. Stirring times exceeding 3 minutes usually do not improve the physical properties of the composition and result in a loss of power.

The composition of the present invention produced as described above may be used as it is for producing various shaped products, but it may be used to produce uniform pellets using a pelletizer and then used for various processing. It is preferable to use it because it is easier to use (and there is no possibility that the polypropylene resin part and the talc part in the composition will separate).

Since the method of the present invention significantly improves the physical properties of the composition (when a molded article is manufactured from it) at a rate that is easy to manufacture, it is possible to effectively incorporate talc into the polypropylene composition,
Unlike known methods, there is no need to separately use fine talc.

The present invention will be explained below with reference to Examples. The talc and polypropylene resins (powder and pellets) used for each experimental side, comparative side, and reference side are as follows.

A. Variety of talc (product name and particle size): (Average particle size) (Manufacturer or distributor and grade name) 10 μ I, Hayashi Kasei ■ FTH Mouth, Fuji Talc ■ PKP-80 ..., Matsuzai Sangyo ■ P-2 Pharmacopoeia 5μ I, Hayashi aJH Micro White 5000A
Mouth, Fuji Talc @ LM8-100 Ha, Matsuzai Sangyo■ /-71 filler t7. D82μ
A, Hayashi Kasei ■ Micro White 5ooos, Japan Talc ■ Micro Ace P-6 Ha, Fuji Talc ■ : [, MS-2QQB, MFR of polypropylene
, Shape and (Product Name) (MFR) (Formation) (Manufacturer and Grade Name) 8.0 Berrett I, Chisso ■ K70191 Powder Mouth, I
Raw material powder for soil 2.5 Good, Chisso ■
Comparative Example 1 of ethylene propylene block copolymer containing 11-0% ethylene (sample Nα1) High-speed mixer with a capacity of 20 t (manufactured by Mitsui Miike Seisakusho, Hexiel) mixer FM20J3 type), talc 1.41C4 (2 (3% by weight)) with an average particle size of 10μ and polypropylene with MFR 8.0 (20% homopolymer powder and pellet 6
0chi) Add 5.6 ounces (80% by weight) and stir for 6 minutes (30% by weight).
00 rpm) to bring the final temperature (maximum temperature reached) of the mixture to 50°C. The mixture was stopped and the mixture was taken out, and test pieces were prepared according to the above-mentioned test method, and the physical properties were measured.

The test piece of this example has inferior DuPont impact strength compared to that of Reference Example 1 below.

Reference Example 1 (Sample Nl12) It was carried out in the same manner as Comparative Example 1 except that talc with an average particle size of 2 μm was used.

Example 1 (Sample Nα6) It was carried out in the same manner as Comparative Example 1 except that the stirring time with the high-speed mixer was 20 minutes and the maximum temperature reached was 130°C.

The test piece of this example had physical properties equivalent to or better than those of Reference Example 1, suggesting that effective pulverization of talc was performed during stirring.

Comparative Example 2 (Sample Na4) Same as Comparative Example 1 except that 20% of ethylene propylene block copolymer (Ethyl v > Contains Ji; 11.0% by weight) powder and 60 ml of pellets were used instead of polypropylene powder. carried out. The test piece of this example was inferior to the first reference example 2 in all measured physical properties, and in particular, the DuPont impact strength was significantly inferior.

Reference Example 2 The same procedure as Comparative Example 2 was carried out except that talc with an average particle size of 2 μm was used.

Example 2 Comparative Example 2 was carried out in the same manner as in Comparative Example 2, except that the stirring time with the high-speed mixer was 20 minutes and the maximum temperature reached was 100°C. The test piece of this example had physical properties equivalent to or better than those of Reference Example 2, suggesting that effective pulverization of talc was performed during stirring.

Example 6 Talc 5.0ky (20% by weight) with an average particle size of 10μ and propylene ethylene copolymer (M:PR2,5) were placed in a high-speed mixer (manufactured by Mitsui Miike Seisakusho ■, Henschel Mixer FM75C type) with a capacity of 75 tons. Ethylene content 11) Powder 20
A total of 20.0 kg (80% by weight) of 60% (chi and pellets) was added and mixed for 20 minutes (164 rpm) to bring the final temperature (maximum temperature) of the mixture to 155°C. The mixture was stopped and the mixture was taken out, and test pieces were prepared according to the above-mentioned test method, and the physical properties were measured. The test piece of this example exceeds all physical properties measured compared to those of Reference Example B below.

For reference, instead of talc with an average particle size of 10μ, use <2μ talc 5
．． The same procedure as in Example 6 was carried out except that Okg (20'M amount %) was used and mixed for 1.6 minutes so that the final temperature (maximum temperature reached) of the mixture was 50°C.

Comparative Example 5 Instead of talc with an average particle size of 10 μm, the same talc 5 with an average particle size of 5 μm was used.
．． The same procedure as Example 6 was carried out except that Okugu (20% by weight) was used and mixed for 6 minutes to bring the final temperature (maximum temperature reached) of the mixture to 50°C. The test piece of this example has all the measured physical properties significantly lower than those of Example 6, and even if 5μ of talc is used, the above-mentioned level of mixing cannot effectively crush the talc. indicates that it has not been carried out.

Comparative Example 4 The same procedure as in Example 6 was carried out except that the mixing time of Merck and propylene ethylene copolymer was 6 minutes and the final temperature (maximum temperature reached) was 50°C.

The physical properties of the test piece of this example were not only significantly lower than those of Example 3, but were also much worse than those of Comparative Example 6. From the above results, it can be seen that when 10μ talc is used, the talc is ground even more insufficiently during mixing than when 5μ talc is used.

Comparative Example 5 In the same high-speed mixer as in Example 1, 10 kg (40% by weight) of talc with an average particle size of 10 μm and VFR were added.

2.5 propylene ethylene copolymer (ethylene containing i1
1.0%) 20 ky powder and 40 % pellets 15 ky (
60% by weight) and mixed for 6 minutes until the final temperature (maximum temperature reached) of the mixture was 50°C.

The mixture was stopped and the mixture was taken out, and test pieces were prepared according to the above-mentioned test method, and the physical properties were measured. The test piece of this example was inferior in all physical properties measured when compared with the test piece of Example 4, which was prepared in Example 4.

Example 4 Comparative Example 5 was carried out in the same manner as in Comparative Example 5, except that the mixing time was 20 minutes and the final temperature (maximum temperature reached) of the mixture was 130°C. The physical properties of the test piece of this example are rather superior to those of the following Reference Example 4, which uses talc with an average particle size of 2 μm, and the physical properties of the test piece of this example are rather superior to those of the following Reference Example 4, which uses talc with an average particle size of 2 μm. This suggests that crushing was performed more effectively.

Reference Example 4 Comparative Example 5 was carried out in the same manner as in Comparative Example 5 except that 2 μm talc was used on top of talc having an average particle size of 10 μm.

Reference example 5 High-speed mixer C with a capacity of 500 mm manufactured by Yoda Seisakusho ■.

Super mixer 5NG-, 500 type) with an average particle size of 2μ
Talc? Propylene-terene copolymer with +Okg (2u weight%) and MFR3.0 (technical content 11.0%)
) 20% powder and 6G pellets (80% by weight) were added and mixed for L minutes (720 rpm) to bring the final temperature (maximum temperature) of the mixture to 50°C. Stop, remove the mixture, and prepare test pieces according to the test method described above.
The test piece of this example had a high mixing ratio of copolymer, so the flexural modulus was inferior to that of Reference Example 4, but the DuPont impact strength was , is outstanding.

Example 5 Talc with a particle size of 2 μm: Instead, 10 μm of talc was used, and the mixing time (2 minutes) was 125·T, y, , L, :, 1.21
2; External procedure 1 was carried out in the same manner as in Reference Example 5. Test piece 1 of this example
Tetsu;βte7Y, 1 constant 1. 8- The physical properties exceed all of those of Reference Example 5, and the crushing power of talc obtained by the above-mentioned mixing.

It is done effectively, loko, -ra j (7).

Example 6 The mixing ratio of talc and copolymer was 40'% (weight) of the former,
The latter consists of 20 g of powder and 60 g of 4% dissection (by weight)
The same procedure as in Example 5 was carried out except for the following. It is appropriate to compare the results of this example with Example 4 in terms of the mixing ratio. Then, the physical properties of the test piece are almost the same as those of Example 4, and even if the capacity of the mixer (and stirring speed) is different, if the grinding time and final temperature are the same, almost the same results can be obtained. It is clear that

Claims (3)

[Claims] (1) 10 to 50% by weight of talc with an average particle size of 5 μ to 20 μ to the entire composition is mixed with polypropylene resin, mixed for 10 minutes or more with a high-speed mixer, and heated to form a composition at the time of mixing. A method for producing a high impact resistant polypropylene composition, characterized by bringing the maximum temperature of the material to 100°C or more and 150°C or less. (2) The manufacturing method according to claim (1), wherein the polypropylene resin is a propylene homopolymer or a propylene-ethylene block copolymer having an ethylene content of 1 to 60% (by weight). (3) Claim No. 3 (2) in which polypropylene powder and polypropylene pellets are used together as the polypropylene resin (
The manufacturing method described in section 1).