JPH0420509A - Production of thermal decomposition wax - Google Patents

Abstract

PURPOSE:To obtain a thermal decomposition wax having a good hue and a low foreign matter content by a continuous stable long-term operation by thermally decomposing an olefin polymer in the presence of a higher fatty acid and/or a hydrochloric acid absorber. CONSTITUTION:A high-quality thermal decomposition wax is obtained by thermally decomposing an olefin polymer (e.g. polyethylene or polypropylene) in the presence of a higher fatty acid and/or a hydrochloric acid absorber. Examples of the higher fatty acids used include palmitic acid and stearic acid. As the hydrochloric acid absorber, a metal salt of a higher fatty acid (e.g. sodium stearate), hydrotalcite, calcium oxide or the like can be used. It is also possible to add optionally a heat stabilizer (e.g. 2,6-di-t-butyl-4-methylphenol), a surfactant, a lubricant, etc.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for producing pyrolytic wax, and in particular, the production of pyrolytic wax of high quality with good hue and low content of foreign substances by continuous operation for a long period of time. This invention relates to a method for producing pyrolytic wax that can be stably produced.

<Prior art> Conventionally, low molecular weight polyolefins such as polyethylene and polypropylene have been used as waxes as pigment dispersants, rubber processing aids, resin processing aids, additives for inks or paints,
It is used in a wide range of applications, including textile treatment agents and toners for electrostatic copying. In recent years, the demand for waxes for these uses has been increasing, and demands for higher quality waxes have become increasingly strict.

By the way, methods for obtaining low molecular weight polyolefins include methods by telomerization of olefins, methods for thermally degrading high molecular weight polymers, and methods for separating and purifying low molecular weight polymers produced as by-products in the production of high molecular weight polymers. and so on. Among these, the method using thermal degradation is known as an economical method.

<Problems to be Solved by the Invention> However, in the method using thermal degradation, the reaction conditions are generally severe, so the resulting low molecular weight polyolefin has poor hue due to thermal history, and thermal degradation occurs in the reactor. It has a tendency to generate foreign matter, which may make continuous production difficult. In order to solve these problems, a method has been proposed in which thermal decomposition is carried out in the presence of an inert gas containing water vapor. (Tokuko Showa 4
(Japanese Patent No. 3-9368) However, this method has significant restrictions in preventing corrosion of the equipment and selecting materials for the equipment, and the reaction operation is complicated, which may pose a practical problem.

Therefore, the purpose of the present invention is to provide high-quality thermal decomposition with a good hue and a low content of foreign substances because the generation of heat-degraded foreign substances in the reactor is suppressed by a simple method with few practical restrictions. It is an object of the present invention to provide a method capable of stably producing wax over a long period of time by continuous operation.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a method for producing a pyrolytic wax that includes a step of pyrolyzing an olefin polymer in the presence of a higher fatty acid and/or a hydrochloric acid absorbent. The present invention provides a method.

Hereinafter, the method for producing pyrolytic wax of the present invention will be explained in detail.

Examples of the olefin polymer that is a starting material in the method of the present invention include a homopolymer of α-olefin, a copolymer of at least two α-olefins, or a copolymer of α-olefin and the α-olefin. Examples include copolymers with other polymerizable polymers.

Examples of the α-olefin include ethylene, propylene, 1-butene, isobutyne, 1-pentene, 2-
Methyl-1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-
Pentene, 1-heptene, 1-octene, 1-decene,
1-dodecene, 1-tetradecene, 1 hexadecene, 1
-octadecene, 1-icosene, etc.

Other monomers copolymerizable with these α-olefins include, for example, acrylic acid, acrylic esters, methacrylic acid, methacrylic esters, vinyl acetate,
Examples include polybasic unsaturated carboxylic acids such as maleic acid, anhydrides thereof, and esters thereof. These may be used alone or in combination of two or more.

In particular, the method of the present invention uses homopolymers of α-olefins such as polyethylene, polypropylene, poly-1-butene, and poly-4-methyl-1-pentene, or copolymers mainly composed of these α-olefins. It is useful for pyrolysis to produce pyrolytic waxes composed of low molecular weight polymers.

In the method of the present invention, the olefin polymer is thermally decomposed in the presence of a higher fatty acid and/or a hydrochloric acid absorbent.

Examples of higher fatty acids used include capric acid,
Examples include those having 10 or more carbon atoms, such as lauric acid, misostic acid, palmitic acid, stearic acid, oleic acid, 12-hydroxystearic acid, ricinoleic acid, araxic acid, behenic acid, and montanic acid.

Examples of the hydrochloric acid absorbent include metal salts of higher fatty acids, epoxidized products of higher fatty acid esters, pyrotalcite, and calcium oxide.

Specific examples of metal salts of higher fatty acids include the metal salts of higher fatty acids listed above, and examples of metals include lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, cadmium,
Examples include aluminum, tin, and lead.

Further, specific examples of epoxidized products of higher fatty acid esters include epoxidized products of octyl stearate.

In the method of the present invention, even if one of these higher fatty acids or hydrochloric acid absorbents is used alone, it can exceed 2f! A combination of the above may also be used.

Among these, preferred higher fatty acids are stearic acid, balmitic acid, and 12-hydroxystearic acid, and preferred hydrochloric acid absorbents are calcium stearate, aluminum stearate, and magnesium stearate.

In the method of the present invention, the amount of higher fatty acid and/or hydrochloric acid absorbent used is usually about 0.001 to 1 part by weight, preferably 0.01 to 0 parts by weight, based on 100 parts by weight of the olefin polymer. The amount is about .5 parts by weight.

In addition, in the method of the present invention, heat stabilizers, weather stabilizers,
Surfactants, lubricants, nucleating agents, antiblocking agents, etc. can be used.

Examples of the heat stabilizer used include phenol stabilizers, organic phosphorus stabilizers, and the like.

Specific examples of phenolic stabilizers include 26-di-t-
Butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,6-cyclohexyl-4-methylphenol, 2,6-dibutyl-4-methylphenol
-Ethylphenol, 2,6-di-t-amyl-4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n
-Octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-
4-ethyl-6-t-hexylphenol, 2-cyclohexyl-4-n-butyl 6-itubrobylphenol, di-α tocopherol, t-butylhydroquinone,
2.2'-methylenebis(4-methyl-6-t-butylphenol), 4.4'-butylidenebis(3-methyl-6-t-butylphenol), 4.4'-thiobis(3-methyl6-t- butylphenol), 2.2'
-thiobis(4-methyl-6-t-butylphenol),
4.4'-methylenebis(2,6-di-t-butylphenol), 2.2'-methylenebis[6-(1-methylcyclohexyl)p-cresol], 2.2'-ethylidenebis(2,4-di-t-butylphenol), -t-butylphenol),
2.2'-Butylidenebis(2-t-butyl-4-methylphenol), i,1.3-tris(2-methyl-4
-Hydroxy-5-t-butylphenyl)butane, triethylene glycol-bis[3-(3-t-butyl-5
-methyl-4-hydroxyphenyl)propionate]
, i, 6-hexanethiol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thiodiethylenebis[3-(3,5-di-t- -butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylene his (3,5-sheet t
-butyl-4-hydroxyhydroxycinnamite), 3.
5-di-t-butyl-4 hydroxyhenzyl phosphonate ethyl ester, 1,3.5-1-lis(2,6
-Simethyl-3-hydroxy-4-t-butylhensyl)in cyanurate, 1,3. ．． 5-tris [(3,5
-di-t-butyl-4-hydroxyphenyl)propionyloxyethylcoin cyanurate, tris(4-t
-butyl-2,6-simethyl-3-hydroxyhensyl)in cyanurate, 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-cyt-butylanilino)-1,3, 5-triazine, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate comethane, bis(3,5-di-t-
butyl-4-hydroxybenzyl ethyl phosphonate) calcium, bis(3,5-di-t-butyl-4-hydroxybenzyl ethyl phosphonate) nickel, bis[3,
3-bis(3-t-4-hydroxyphenyl)butyric acidocoglycol ester, N,N'-bis[(
3,5-di-7-butyl-4-hydroxyphenyl)propionylcohytrazine, 2,2'-oxamide bis[
Ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'methylenebis(4-methyl-6-t-butylphenol)terephthalate, 1,3,5-trimethyl- 2,4,6-tris(
3,5-di-t-butyl-4-hydroxybenzyl)benzene, 3,9-bis[1,1-dimethyl-2-((3
-t-butyl-4-hydroxy-5-methylphenyl)
propionyloxy)ethyl2.4,8.10-tetraoxaspiro[5,5]undecane, 2.2-bis[4-(2-(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl) oxy))ethoxyphenylcopropane, or β-(3,5-di-t-butyl-4
-hydroxyphenyl) propionic acid alkyl esters. Among these, 2,6-di-t-butyl-4-methylphenol, tetrakis[methylene-3-(3,□5-di-t-butyl-4-hydroxyphenyl)propionate comethane, or β-(
Preferred is n-octadecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, which is a 3,5-di-t-butyl-4-hydroxyphenyl)propionic acid alkyl ester.

Specific examples of organic phosphorus stabilizers include trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl-diphenyl phosphite, and tris(
2,4-di-t-butylphenyl) phosphite, triphenyl phosphite, tris(butoxyethyl) phosphite, tris(nonylphenyl) phosphite,
Distearylpentaerythritol diphosphite, tetra(tridecyl)1.1.3-)-lis(2-methyl-5-t-butyl-4-hydroxyphenyl)butane diphosphite, tetra(C12-CI5 mixed alkyl)
-4,4'-isopropylidene diphenyl diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-t-butylphenol) diphosphite, tris(3,5-di-t-butyl-4 -hydroxyphenyl) phosphite, tris(mono-dimixed nonylphenyl) phosphite, hydrogenated -4,4'-isopropylidene diphenol polyphosphite, bis(octylphenyl) bis[4,4'-butylidene bis(
3-methyl-6-t-butylphenol) ・1,6
-Hexanediol diphosphite, phenyl 4.4
'-isopropylidene diphenol pentaerythritol diphosphite, tris [4,4'-isopropylidene bis(2-t-butylphenol) cophosphite, phenyl diisodecyl phosphite, di(nonylphenyl) pentaerythritol diphosphite, tris (1,3-di-stearoyloxyisopropyl)phosphite, 4,4'-isopropylidene bis(2-t-
butylphenol) di(nonylphenyl) phosphite, 9.10-di-hydro-9-oxa-9-oxa-
Examples include 10-phosphaphenanthrene-10-oxide and bis(dialkylphenyl)pentaerythritol diphosphite esters.

The bis(dialkylphenyl)pentaerythritol diphosphite esters include spiro-type and cage-type ones.

Usually, such phosphite esters are often used as a mixture of isomers represented by the above formula for economic reasons in the production method.

Here, in the above formulas (1) and (2), RI
R2 is an alkyl group having 1 to 9 carbon atoms, preferably a branched alkyl group, particularly preferably a t-butyl group. Furthermore, R1 in the phenyl group. The substitution position of R2 is particularly preferably at the 2,4,6 position.

Specific examples of these bis(dialkylphenyl)pentaerythritol diphosphite esters include bis(dialkylphenyl)pentaerythritol diphosphite esters.
2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-t-butyl-4
-methylphenyl)pentaerythritol diphosphite.

In addition, as an organic phosphorus stabilizer, a phosphonite having a structure in which carbon and phosphorus are directly bonded, such as tetrakis(2,4-di-t-butylphenyl)-4,4'-
Also included are biphenylene diphosphonite and the like.

Among the above organophosphorus stabilizers, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)44'-bipheni Range phosphonites are preferred.

In the present invention, when the heat-resistant stabilizer is used, the phenolic stabilizer and organic phosphorus stabilizer may be used alone or in combination of two or more.

When using this heat stabilizer, the amount used is usually
1 part by weight of the higher fatty acid and/or hydrochloric acid absorbent.
About 0.1 to 30 parts by weight, preferably 0.5 to 1
0 parts by weight.

In the method of the present invention, the method of supplying these higher fatty acids and/or hydrochloric acid absorbents and additives used as necessary to the thermal decomposition reaction of the olefin polymer is not particularly limited. A method in which the olefin polymer is kneaded in advance when pelletizing it; a method in which the raw olefin polymer is added to the raw material simultaneously, batchwise or continuously, when the raw olefin polymer is supplied to the reactor; A method of supplying to the reactor completely separately from coalescence: A method of supplying a commercially available raw material olefin polymer with these higher fatty acids and/or hydrochloric acid absorbents, additives, etc. mixed in advance. Good too.

The method of the present invention involves subjecting an olefin polymer to a thermal decomposition reaction in the presence of the higher fatty acid and/or hydrochloric acid absorbent and, if necessary, using additives such as a heat stabilizer. This is a method to obtain decomposed wax.

The reactor used may be any device such as a tubular pyrolysis device or a tank-type pyrolysis device.

As a tubular pyrolysis device, a double-tube type consisting of an inner tube through which the reaction mixture flows and an outer tube through which the heating medium flows;
It may be of any type, such as a multi-tube type having a plurality of reaction tubes through which the reaction mixture flows, as long as it efficiently heats the reaction mixture flowing inside and thermally decomposes the olefin polymer. good.

The seed type pyrolyzer is usually equipped with a stirrer and a heating jacket, but may also be equipped with an external circulation pump and a heat exchanger to further enhance the effects of stirring and heat transfer.

The number of stages of the device may be one stage or multiple stages, and
The operating method may be either a batch method or a continuous method.

The material of the apparatus, particularly the material of the surface that comes into contact with the reaction mixture, is preferably carbon steel, chrome steel, chrome-nickel cap, or high nickel steel such as Incoronium Hastelloy or Inconel.

Heating of these pyrolyzers is not limited, and any method such as heating with an electric heater, low frequency induction heating, or heating with a molten salt heating medium may be used.

To supply the raw material olefin polymer to the pyrolysis machine, an extruder is connected to the raw material inlet of the pyrolysis machine, and the raw material olefin polymer is melted in advance by the extruder and then supplied to the pyrolysis machine. This is preferable because it can be adapted to various raw material polymers having different physical properties and can be smoothly supplied, and the thermal decomposition reaction can be carried out efficiently.

Furthermore, the atmosphere of the supply route of the raw material olefin polymer,
Furthermore, it is effective to make the reaction atmosphere in the pyrolysis reactor an inert gas atmosphere in order to improve the quality of the pyrolysis wax obtained.

The reaction conditions in the thermal decomposer may be appropriately selected depending on the type and molecular weight of the raw material olefin polymer, the desired molecular weight of the thermally decomposed wax, and the like. For example, the reaction temperature is usually about 300 to 450°C, especially about 36°C.
The temperature is preferably about 0 to 430°C. The reaction pressure is usually
It is about 5 Torr ~ 50 kg / cm2 G,
Particularly preferably 500 Torr to 1.8 kg/cm2
It is about G. In addition, the reaction time is usually 10 minutes to 5 minutes.
The time is preferably about 30 minutes to 3 hours.

<Example> Hereinafter, the present invention will be specifically explained by giving examples and comparative examples of the present invention.

(Examples 1 to 3, Comparative Example 1) According to the apparatus shown in FIG. , the extruder 1 was supplied through the supply port 11, passed through the distribution channel 12, and continuously supplied to the tubular pyrolysis machine 3 equipped with the heating device 2, and pyrolyzed wax was manufactured continuously for 9 days according to the following conditions. I did it.

In addition, in Comparative Example 1, operation was stopped on the second day.

Extruder screw diameter: 39.85mm Cylinder diameter: 40. Omm Extruder temperature (temperature at presser outlet = 300°C Extrusion rate: 10,5 kg/hr Tubular pyrolyzer reaction tube diameter: 50mm Heating temperature: 402°C Internal pressure normal pressure residence time: 33m1n (raw material supply amount Standard) Next, the continuously obtained reaction mixture was subjected to gas-liquid separation to remove volatile components to produce pyrolytic wax, and samples were taken every day of operation.

The hue and foreign matter content of the pyrolytic wax samples obtained for each number of operating days were measured according to the following method. The results are shown in Table 1.

Powder hue: A sample was pulverized into a powder with an average particle size of about 300 mm, and the hue of the obtained powder was measured using a Hunter Lab color difference meter.

Melting color: The sample was melted at 180° C. and the color of the melted sample was compared with a Hazen if colorimetric solution using a colorimetric tube.

The content of foreign substances was determined indirectly by the value obtained by measuring the hue of the powder.
As the amount of foreign matter increases, the whiteness decreases and the L value decreases.

<Effects of the Invention> According to the method of the present invention, a pyrolyzed wax of high quality in terms of hue, content of foreign substances, etc. can be obtained by thermally decomposing an olefin polymer, and furthermore, this high quality pyrolyzed wax can be obtained by thermally decomposing an olefin polymer. It has great practical industrial value because it allows production to be carried out stably for a long period of time in continuous operation.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating an apparatus used in an example of the present invention and a comparative example. Description of signals 1... Extruder, 2... Heating device, 3... Tubular pyrolyzer, 11... Supply port, 12... Distribution route

Claims (1)

[Claims] A method for producing a pyrolytic wax comprising the step of pyrolyzing an olefin polymer in the presence of a higher fatty acid and/or a hydrochloric acid absorbent.