JP2005002184A - Method for producing polyolefin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyolefin composition, with which a plurality of liquid additives are simply and accurately added by using the same equipment in producing the polyolefin composition by melting and kneading a powdery polyolefin with the additives. <P>SOLUTION: The method for producing the polyolefin composition by melting and kneading the powdery polyolefin with the plurality of the additives comprises premixing the plurality of the additives having ≤90°C melting points and melting them to give a uniform liquid and feeding the liquid by using the same metering pump. In the production method, the powdery polyolefin is one selected from homopolypropylene, an ethylene-propylene block copolymer, an ethylene-propylene random copolymer and a propylene-butene-1 copolymer as the concrete example. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyolefin composition. More specifically, the present invention relates to a method for producing a polyolefin composition using a simple addition method in which a plurality of additives are mixed and melted in advance in a method for producing a polyolefin composition by melting and kneading powdered polyolefin together with additives. It is.
[0002]
[Prior art]
The raw materials for resin products and the like are usually produced as a polyolefin composition in the form of pellets by melting and kneading together with powdered polyolefin and talc, an antioxidant, a lubricant, an antistatic agent, an antifungal agent, a neutralizing agent and the like. The physical properties of these additives range from powders to liquids at room temperature to those in the middle of them. Depending on the addition conditions, it is difficult to add at the same time, and the addition amount is small, so the quantitative properties are low. Not only is it bad and the operation is complicated, but it is also difficult to install a large number of facilities for each additive. A method of adding was desired.
[0003]
Conventionally, as a method of adding such a plurality of additives, a granular additive continuous mixing apparatus (see Patent Document 1) in which granular materials are uniformly and continuously mixed and added, or a solid additive and crystallinity are added. A method is described in which polypropylene is introduced into a mixer and mixed, and then a liquid additive is mixed (see Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 5-115764 (pages 2 to 3)
[Patent Document 2]
JP-A-8-165383 (page 2 to page 4)
[0005]
[Problems to be solved by the invention]
In such a situation, the problem to be solved by the present invention is to add a plurality of additives simply and accurately using the same equipment when a polyolefin composition is produced by melt-kneading powder polyolefin together with additives. The object is to provide a method for producing a polyolefin composition.
[0006]
[Means for Solving the Problems]
That is, the present invention is a method for producing a polyolefin composition by melting and kneading a powdered polyolefin and a plurality of additives, and after mixing and melting a plurality of additives having a melting point of 90 ° C. or less in advance to obtain a uniform liquid, The present invention relates to a method for producing a polyolefin composition, wherein the polyolefin composition is supplied using the same metering pump. The present invention is applicable to a method for producing a polyolefin composition in which the powdered polyolefin is one selected from homopolypropylene, ethylene propylene block copolymer, ethylene propylene random copolymer, and propylene butene-1 copolymer. It is another aspect.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the powdered polyolefin is a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, and usually has an average particle diameter of 300 μm to 1500 μm. Examples thereof include homopolypropylene, ethylene-propylene block copolymer, ethylene-propylene random copolymer, and propylene-butene-1 copolymer.
[0008]
In the present invention, the additives are not only elastomers and talc, but also antioxidants, lubricants, UV inhibitors, antistatic agents, antiblocking agents, nucleating agents, which are added to impart various properties necessary for the polyolefin composition. It is an additive such as an agent.
[0009]
Elastomer is a copolymer of ethylene and α-olefin, such as ethylene-octene, ethylene-hexene, ethylene-pentene, ethylene-butene, ethylene-propylene copolymer, mainly improving the impact resistance of polyolefin compositions. An appropriate copolymer is selected for improving physical properties according to applications such as imparting softness and improving appearance. Talc is an additive mainly added for the purpose of improving the rigidity of the polyolefin composition, mainly composed of silicon dioxide and magnesium oxide.
[0010]
Examples of the additives include those added to impart various properties necessary for the polyolefin composition, such as antioxidants, lubricants, UV inhibitors, antistatic agents, antiblocking agents, and nucleating agents as described above. The For example, as an antioxidant, 2,6-di-tertiary butyl-4-methylphenol, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate ] Methane, octazyl 3- (3'-5'ditetrabutyl-4-hydroxyphenyl) propionate, tris (2,4-di-t-butylphenyl) phosphite, pentaerythrityl-tetrakis [3- (3,5- Di-t-butyl-4-hydroxyphenyl) propionate, dl-α-tocopherol, dimyristyl-3,3′-thiodipropionate, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, Tris (2,4-di-t-butylphenyl) phosphite, 3,9-bis [2- (3- (3-t-butyl) 4-hydroxy-5-methylphenyl) propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] un, 6- [3- (3-butyl-4 -Hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-t-butyldibenz [d, f] [1,3,2] dioxaphosphine and the like.
[0011]
Examples of the lubricant include erucic acid amide, oleic acid amide, ethylene bisstearyl alumide, erucyl amide, dimethylpolysiloxane and the like.
[0012]
Examples of UV inhibitors include 2,4-di-t-butylphenyl-3 ′, 5 ′, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, tetrakis (1,2,2, 6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate and the like.
[0013]
Examples of the antistatic agent include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, polyoxyethylene alkylamine mixed compositions, nonionic surfactants, polyoxyethylene alkylamine / higher alcohol mixtures, and the like.
[0014]
Examples of the anti-blocking agent include calcium carbonate, silicon dioxide, polymethylsilsesquioxane, aluminum silicate salt, and a crosslinked polymethyl methacrylate.
[0015]
As the nucleating agent, bis [4- (1,1-dimethylethyl) benzoate-0] hydroxyaluminum, dibenzylidene sorbitol, 2,2′-methylenebis (4,6-di-t-butylphenyl) sodium phosphate And phosphate ester compounds.
[0016]
Examples of the neutralizing agent include calcium stearate, magnesium stearate, basic aluminum / magnesium carbonate, calcium hydroxide, and other talc.
[0017]
Most of these additives are solid at room temperature, and the melting point ranges from about −40 ° C. to about 1500 ° C. talc in a very wide range. Therefore, when supplying a polyolefin composition together with a powdered polyolefin to produce a polyolefin composition, if these several types of additives are mixed with the polyolefin and supplied to the kneading granulator, the temperature of the kneading granulator is reduced. For this reason, certain additives may be in a semi-molten state, and the sticky additive may not be smoothly fed with other additives, resulting in a non-uniform polyolefin composition. Therefore, several types of additives with a melting point of 90 ° C. or lower are mixed in advance to form a molten state, and a plurality of additives can be added using a single facility by adding them with a metering pump. A polyolefin composition in which additives are uniformly mixed can be obtained.
[0018]
Among the additives exemplified above, those having a melting point of 90 ° C. or lower include 2,6-ditertiary butyl-4-methylphenol and octazyl 3- (3′-5′ditetrabutyl-4-hydroxyphenyl) propionate. , Dl-α-tocopherol, dimyristyl-3,3′-thiodipropionate, erucic acid amide, oleic acid amide, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, tetrakis (1, 2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, polyhydric alcohol fatty acid ester such as glycerin fatty acid ester, polyoxyethylene alkylamine mixed composition, nonionic system Surfactants, antioxidants such as polyoxyethylene alkylamine / higher alcohol mixtures, UV Agents, antistatic agents and the like.
[0019]
Hereinafter, it demonstrates with the flowchart (FIG. 1) which showed an example of the manufacturing method of the polyolefin composition by this invention. A powdered polyolefin from the hopper 1 and a solid additive such as an antioxidant, an antiblocking agent, and a nucleating agent having a melting point higher than 90 ° C. from the hopper 2 are weighed in a meter 3 and charged into the mixing hopper 4. The hopper 5 is charged with an additive having a melting point of 90 ° C. or less in a specified amount ratio, and the mixing tank 6 is heated to 60 to 90 ° C. with steam 7 and melted and mixed to obtain a uniform liquid mixture. . In the mixing hopper 4, the powders supplied from the hopper 1 and the hopper 2 are mixed and supplied to the kneading granulator 9. On the other hand, a predetermined amount of the additive having a melting point of 90 ° C. or less which has been melted and mixed into a uniform liquid mixture is supplied to the kneading granulator 9 by the metering pump 8. The melt-kneaded polyolefin composition is granulated into pellets, sent to the pellet silo 11 via the shifter 10, and shipped as a product.
[0020]
【Example】
The present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
Example 1
As shown in FIG. 1, powder polypropylene is used for the hopper 1, and powders of antioxidant, antiblocking agent and nucleating agent having a melting point higher than 90 ° C. are measured for the hopper 2 with a measuring device 3. It was thrown into. On the other hand, oleic acid amide and polyoxyethylene alkylamine / higher alcohol mixture, which are additives having a melting point of 90 ° C. or less, are charged into the mixing tank 6 from the hopper 5 so as to have a ratio of 1: 3. The mixture was melted and mixed. The mixture became a uniform liquid mixture and was not separated even after standing for a long time.
A mixture of powdered polypropylene, antioxidant, antiblocking agent, and nucleating agent is mixed from the mixing hopper 4 while a uniform liquid of an oleic acid amide and polyoxyethylene alkylamine / higher alcohol mixture which are additives having a melting point of 90 ° C. or lower. The mixture was supplied to the kneading granulator 9 with the metering pump 8 to produce a polypropylene composition. As a result of analyzing the additive of the produced polypropylene composition, oleic acid amide is 0.097%, polyoxyethylene alkylamine / higher alcohol mixture is 0.31%, and a plurality of liquid additives are mixed uniformly. Thus, it was confirmed that it was put into a kneading granulator.
[0021]
【The invention's effect】
According to the present invention, when a polyolefin composition is produced by melt-kneading a powdered polyolefin together with an additive, a plurality of liquid additives can be easily and accurately added using the same equipment. It became possible to provide a method.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an example of a manufacturing method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hopper 2 ... Hopper 3 ... Metering device 4 ... Mixing hopper 5 ... Hopper 6 ... Mixing tank 7 ... Steam 8 ... Metering pump 9 ... Kneading granulator 10 ... Shifter 11 ... Pellet silo

Claims (2)

In a method for producing a polyolefin composition by melting and kneading powdered polyolefin and a plurality of additives, a plurality of additives having a melting point of 90 ° C. or lower are mixed and melted in advance to form a uniform liquid, and then the same metering pump is used. A method for producing a polyolefin composition. The method for producing a polyolefin composition according to claim 1, wherein the powdered polyolefin is one selected from a homopolypropylene, an ethylene propylene block copolymer, an ethylene propylene random copolymer, and a propylene butene-1 copolymer. .

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