JPS58136640A - Polyolefin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent moldability and does not undergo discoloration, by blending a uniform mixture of a higher fatty acid and its metal salt selected from Group IIa or IIb metals, with a polyolefin. CONSTITUTION:A polyolefin compsn. is obtd. by blending a uniform mixture consisting of a higher fatty acid such as lauric acid or palmitic acid and its metal salt selected from Group IIa and IIb metals such as calcium laurate or barium palmitate, with a polyolefin such as PE. Even when this compsn. is molded into a thin film by inflation, the film little suffers bursting at its expanded part and a stable continuous operation is possible. Even when a high- speed melt spinning is conducted to produce a monofilament, thread breakage does not occur. With regard to the possibility of discoloration caused of zinc salt of a higher fatty acid, a sufficient discoloration preventing effect can be obtd. by using a powdered higher fatty acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyolefin compositions. More specifically, the present invention relates to a polyolefin composition with excellent moldability and no coloring.

"Polyethylene produced by Ziegler catalyst,"
It is a well-known technique to blend higher fatty acid metal salts into polyolefin materials such as polypropylene for the purpose of imparting rust prevention properties and increasing the 1:1 diameter during bath melt extrusion. Calcium stearate is commonly used for pigeons. By the way, polyethylene made by blending @salt with alkaline earth gold of higher fatty acid represented by calcium stearate can be formed into a film, especially a thinner film, by melt extrusion method, inflation coloring method, etc. Produced by blow molding method.

When molded, etc., the appearance of a molded film or molded article was produced there. In addition to the formation of aggregates, when a film is inflation-molded, the presence of such aggregates causes it to expand under air pressure and form a stable cylindrical group. A serious problem was observed in that the expanded portions to be formed would tear apart, making it impossible to consistently and stably produce thin tin films. Furthermore, in the case of 1i lead salt, when it is used in combination with a 7 er/- yarn stabilizer, there is a drawback that the hue becomes dark 1.

As a result of various studies on polio and reflexine compositions that can maintain a good discharge rate during bath melt extrusion without causing any disadvantages, the present inventors found that polyolefins contain higher fatty acids and their periodic rules 12ffa, IIb. It has now been found that formulations of homogeneous mixtures of group metal salts can achieve the desired objectives.

The polyolefin to be modified is polyethylene, polypropylene, poly(4-methyl-!-pentene), etc., preferably polyethylene, especially for the production of ultrathin films by inflation molding, whose melt index (190 °C) about 0.02 to 0, o5.
15 degrees Fh O, 95~0.969Atl (D
Mo is preferable.

Periodic table Era, Hb group metal salts and compounds *#! Examples of the higher fatty acids used in the form include higher fatty acids having 10 or more carbon atoms, preferably 14 to 24 carbon atoms, such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid. Examples include. la.

Examples of the lb group metal salts include calcium salts, barium salts, Tk lead salts, and magnesium salts of these higher fatty acids, such as stearin 1'#, calcium, barium stearate, submersal stearate, and magnesium stearate. , carunium palmitate, magnesium valmitate, barium palmitate, etc. are used, and calcium salts such as calcium stearate are particularly preferred.

When only these higher fatty acid gold-14 salts are blended into polyolefin and the resulting granules are molded, aggregates of higher fatty acid metal salts are likely to be formed in the molded product, and the formation of aggregates depends on the blending ratio. Most likely first place.

However, with respect to this higher fatty acid gold #11 weir, it is preferable to mix llili grade fatty trowel at a ratio of about 0.1 to 400%, preferably about 1 to 100%, more preferably about 5 to 30%. If the mixing ratio is below, the formation of aggregates cannot be suppressed, while if the mixing ratio is higher than this, the rust prevention properties of the gold salt will be reduced, and the working environment will be deteriorated such as a bad odor will be observed during molding). However, the weight is about 0.
When blended and granulated, it not only exhibits good moldability and anticorrosion properties, but also reduces the amount of higher fatty acid metal salts in the articles molded from it. Aggregate formation is also effectively suppressed.

This inhibitory effect on aggregate formation is due to the presence of higher fats and their gold
It largely depends on the state of mixing with I4 salt, and the more uniform the state of mixing, the greater the suppressing effect. Therefore, both are used in a uniformly mixed state in advance, and their mixing can be done by tri-blending using a tumbler mixer, Hensier mixer, etc., or by melt-mixing this tri-blend while stirring, and then cooling it. A more uniform mixed state is formed in this order. In addition to these methods, particularly preferred methods include adding a smaller equivalent amount of metal hydroxide or oxide to the higher fatty acid, neutralizing it in a molten bag, and pulverizing it, or adding it to the higher fatty acid in a solvent such as alcohol. Examples include a method of neutralizing with water and removing the solvent.

In this way, the polyolefin composition blended with a homogeneous mixture of higher fatty acids and their gold moulds, maintains a good discharge rate during melt extrusion, and improves F& shape properties and non-coloring properties. Regarding moldability, higher fatty acid metal salts deteriorate the appearance of molded products such as films and bottles. ! The formation of a monofilament film is effectively suppressed, and even when a thin film is formed by the inflation molding method, there is almost no rupture of the expanded part, and stable continuous operation is therefore possible. Even when performing high-speed melt spinning such as
This effectively solves problems such as V-forming, which causes yarn breakage, and the inability to improve yarn strength because the stretching ratio cannot be increased too much. Furthermore, regarding the coloring property seen in the case of higher fatty acid zinc salts, a sufficient coloring prevention effect can be seen even if higher fatty acids are mixed with the higher fatty acids in powder form.

Next, the present invention will be explained with reference to examples.

Examples 1 to 5, Comparative Examples 1 to 5 Polyethylene powder (melt index 0.045) produced by polymerization using a highly active Ziegler catalyst without going through a catalyst removal step, 3- as an antioxidant
(4-hydroxy-3,5-di-tert-butylphenyl)
0.05% by weight of 2-methylheptyl ester of propionic acid (relative to polyethylene, the same applies hereinafter), phosphorus stabilizer (product of Adeka Argus, Mark 32910.1% by weight, and stearic acid and its metals shown in the coating below) The salt mixture was mixed under a nitrogen atmosphere using a Henschel mixer heated to 80 to 100°C, and then granulated into pellets using an extruder at a resin temperature of 260°C.

Feed the Kono granulated pellets to the inflation molding machine,
After being melted in a cylinder, it was extruded into a tube from a ring-shaped three-line spiral die. One end of this tube
After closing it through two pinch rolls, blow air to expand it to a predetermined size, adjust the take-up speed, and wind up a tubular film with a thickness of 6 μm (10 μm for Comparative Example 1). Ta. Then, such operations were performed continuously for two days.

〔Molding condition〕

Molding machine: Modern 150 inflation molding machine (cylinder inner diameter 50W1 screw metering L/D
-26, die 3-row spiral method 75 cod diameter x 1.2
．． 5) Blow amplifier ratio: 5 □ Temperature (resin temperature): 21s℃ [Measurement method] Measured with a pressure gauge attached to the joint between the resin pressure crab die and the cylinder (uses as a guide for moldability) Extrusion jil
: Film winding per unit time Overlap protection: The inflation molding machine was disassembled and each part of the cylinder, die, and screw was inspected and the presence or absence of reddish-brown rust was observed. Stability during completion: Film molding The color of the film is judged to be good when the swelling part is constantly monitored and the swelling part is formed stably without any abnormality for 2 days.The film is judged to be good if it is translucent white when visually inspected under sunlight. Appearance: Judgment was made by monitoring the film during molding just before the winding machine (Put is a foreign substance thought to be a stearate metal salt aggregate).

Powder mixture B of A stearic acid metal salt and stearic acid: The above powder mixture (A) is heated to about 100 ° C., stirred in a state in which stearic acid is molten, and then cooled and pulverized. Apply several times 0: Calcium hydroxide is melted with an excess equivalent ratio of stearic acid, a part of the stearic acid is neutralized, and then pulverized. Procedure correction 4f (voluntary) 1. Case indication Patent Application No. 18456, filed in 1982. 2. Name of the invention: Polyoleain composition & person making the amendment. Relationship to the case. Name of patent applicant (588) Mitsui Petrochemical Industries, Ltd. 4. Address of agent: Minato-ku, Tokyo. Shiba Daimon 1-2-7 Ato Building 5
Correct issue 01.

Claims (1)

[Claims] 1. A polyolefin composition comprising a polyolefin blended with a homogeneous mixture of a higher fatty acid and its metal salt from groups 1a and lb of the periodic table. 2. The polyolefin composition according to claim FHJ, item 1, wherein the polyolefin is polyethylene. 3. The polyolefin composition according to claim 1, wherein the metal salt of higher fatty acid is a calcium salt. 4. The polyolefin composition according to claim 1, which is used for extrusion molding. 5. The polyolefin composition according to claim 14, which is used for inflation molding.