JP3020555B2 - Method for producing pyrolytic wax - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a thermally decomposed wax, and in particular, to a high-quality thermally decomposed wax having a good hue and a small amount of foreign matter by continuous operation for a long period of time. The present invention relates to a method for producing a pyrolytic wax that can be produced stably.

<Prior art> Conventionally, low molecular weight products of polyolefins such as polyethylene and polypropylene are used as waxes as pigment dispersants, rubber processing aids, resin processing aids, additives for inks or paints, fiber treatment agents, electrostatic copying. It is used for a wide range of applications, such as toners for industrial use. The demand for waxes in these applications in recent years has tended to increase, and the demand for higher quality waxes has become more stringent.

By the way, as a method for obtaining a low molecular weight product of this polyolefin, a method by telomerization of olefin,
There are a method of thermally degrading a high molecular weight polymer, and a method of separating and purifying a low molecular weight polymer by-produced in the production of a high molecular weight polymer. Among these, the method by thermal degradation is known as an economical method.

<Problems to be Solved by the Invention> However, in the method by thermal degradation, generally, the reaction conditions are severe, so that the low molecular weight product of the obtained polyolefin has poor hue due to heat history and also has thermal degradation in the reactor. There is a tendency that foreign matter is likely to be generated, which may make continuous operation of production difficult. Therefore, in order to solve these problems, a method of performing thermal decomposition in the presence of an inert gas containing water vapor has been proposed. (Special Publication 43-93
However, in this method, there are great restrictions on the measures against corrosion of the apparatus and the selection of the material of the apparatus, and the reaction operation becomes complicated, which may be a practical problem.

Therefore, an object of the present invention is to provide a high-quality pyrolysis having a good hue and suppressing the generation of thermally degraded foreign substances in the reactor by a simple method with few practical restrictions and thus having a low foreign substance content. An object of the present invention is to provide a method capable of stably producing a 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 is to melt an olefin polymer in an extruder, and in a pyrolyzer connected to the extruder, in the presence of a hydrochloric acid absorbent, Or, in the presence of a hydrochloric acid absorbent and higher fatty acids, at a temperature of 360 to 430 ° C, for 30 minutes to
An object of the present invention is to provide a method for producing a thermally decomposed wax, which comprises a step of heating for 3 minutes to thermally decompose.

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

Examples of the olefin polymer as a starting material in the method of the present invention include, for example, an α-olefin homopolymer,
A copolymer of at least two or more α-olefins, a copolymer of an α-olefin and another monomer copolymerizable with the α-olefin, and the like can be given.

Examples of the α-olefin include ethylene, propylene, 1-butene, isobutene, 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 and the like.

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

In particular, the method of the present invention comprises a homopolymer of an α-olefin such as polyethylene, polypropylene, poly 1-butene, and poly 4-methyl-1-pentene, or a copolymer containing these α-olefins as a main component. It is useful for producing a thermally decomposed wax composed of a low molecular weight polymer by pyrolysis.

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

Examples of the higher fatty acids used include, for example, those having 10 carbon atoms such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, 12-hydroxystearic acid, ricinoleic acid, arachidic acid, behenic acid and montanic acid. The above are mentioned.

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

Specific examples of the metal salt of a higher fatty acid include the metal salts of the higher fatty acids described above. Examples of the metal include:
Examples include lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, cadmium, aluminum, tin, and lead.

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

In the method of the present invention, these higher fatty acids or hydrochloric acid absorbents may be used alone or in combination of two or more.

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

In the method of the present invention, the amount of the higher fatty acid and / or hydrochloric acid absorbent used is usually about 0.001 to 1 part by weight, preferably about 0.01 to 0.5 part by weight, based on 100 parts by weight of the olefin polymer. is there.

In the method of the present invention, a heat-resistant stabilizer, a weather-resistant stabilizer, a surfactant, a lubricant, a nucleating agent, an anti-blocking agent, and the like may be used, as long as the effects of the present invention are not impaired. it can.

Examples of the heat stabilizer to be used include a phenol stabilizer and an organic phosphorus stabilizer.

Specific examples of phenolic stabilizers include 2,6-di-t
-Butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,6-dicyclohexyl-
4-methylphenol, 2,6-diisopropyl-4-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-isopropylphenol, dl-
α-tocopherol, t-butylhydroquinone, 2,2 ′
-Methylenebis (4-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-
Butylphenol), 4,4'-thiobis (3-methyl-
6-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), 2,2'-butylidenebis (2-t
-Butyl-4-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, triethylene glycol-bis [3- (3
-T-butyl-5-methyl-4-hydroxyphenyl)
Propionate], 1,6-hexanediol-bis [3
-(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 2,2-thiodiethylenebis [3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide),
3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3 , 5-Tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tris (4-tert-butyl-2,6
-Dimethyl-3-hydroxybenzyl) isocyanurate, 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, tetrakis [ Methylene-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane, calcium bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate) calcium, bis (3,5-di-t-butyl-4-hydroxybenzylphosphon) Ethyl) nickel, bis [3,3-bis (3-t-4-hydroxyphenyl) butyric acid] glycol ester, N, N'-bis [(3,5-di-t-butyl-4-hydroxy Phenyl) propionyl] hydrazine, 2,2′-oxazamide 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) propionyloxydiethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 2,2-bis [4- (2- (3,5 −
Di-tert-butyl-4-hydroxyhydrocinnamoyloxy)) ethoxyphenyl] propane, or β-
(3,5-di-t-butyl-4-hydroxyphenyl) propionic acid alkyl esters and the like. Among these, 2,6-di-t-butyl-4-methylphenol, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, or β- (3 N-octadecyl-β- (3,5-di-t-butyl-4-alkyl-4-alkyl-5,5-di-tert-butyl-4-hydroxyphenyl) propionate
(Hydroxyphenyl) propionate is preferred.

Specific examples of the organic phosphorus stabilizer include trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl-diphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, triphenyl phosphite. Phyto, tris (butoxyethyl) phosphite, tris (nonylphenyl) phosphite, distearylpentaerythritol diphosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5
t- butyl-4-hydroxyphenyl) butane diphosphite, tetra (C ₁₂ -C ₁₅ mixed alkyl) -4,4'-isopropylidene diphenyl diphosphite, tetra (tridecyl) -4,4'-butylidene bis (3 -Methyl-6
-T-butylphenol) diphosphite, tris (3,
5-di-t-butyl-4-hydroxyphenyl) phosphite, tris (mono-di-mixed nonylphenyl) phosphite, hydrogenated-4,4'-isopropylidene diphenol polyphosphite, bis (octylphenyl). Bis [4,4'-butylidenebis (3-methyl-6-t-butylphenol)] • 1,6-hexanediol diphosphite, phenyl • 4,4′-isopropylidene diphenol / pentaerythritol diphosphite, Tris [Four,
4'-isopropylidenebis (2-t-butylphenol)] phosphite, phenyl diisodecyl phosphite, di (nonylphenyl) pentaerythritol diphosphite, tris (1,3-di-stearoyloxyisopropyl) phosphite, 4 4,4'-isopropylidenebis (2-t-butylphenol) di (nonylphenyl) phosphite, 9,10-di-hydro-9-oxa-9
-Oxa-10-phosphaphenanthrene-10-oxide or bis (dialkylphenyl) pentaerythritol diphosphite ester.

The bis (dialkylphenyl) pentaerythritol diphosphite esters include spiro type and cage type. Usually, for such a phosphite ester, a mixture of the isomers represented by the above formula is often used for economic reasons in the production method. Here, in the above formulas (1) and (2), R ¹ and R ² are an alkyl group having 1 to 9 carbon atoms, preferably a branched alkyl group, particularly preferably a t-butyl group. It is particularly preferable that the substitution positions of R ¹ and R ² in the phenyl group are at positions 2, 4, and 6.

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

Further, as an organic phosphorus-based stabilizer, a phosphonite having a structure in which carbon and phosphorus are directly bonded, for example, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite and the like are also included. No.

Among the above organic phosphorus stabilizers, bis (2,6-di-
T-butyl-4-methylphenyl) pentaerythritol diphosphite and tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite are preferred.

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

When this heat stabilizer is used, its amount is usually about 0.1 to 30 parts by weight, preferably about 0.5 to 10 parts by weight, per 1 part by weight of the higher fatty acid and / or hydrochloric acid absorbent. .

In the method of the present invention, these higher fatty acids and / or
Alternatively, the method of supplying the hydrochloric acid absorbent and, if necessary, the additives used for the thermal decomposition reaction of the olefin polymer is not particularly limited. For example, when the raw material olefin polymer is pelletized, it is kneaded in advance. A method of adding the raw material olefin polymer to the reactor at the same time as supplying the raw material olefin polymer to the reactor, or a method of supplying the raw material olefin polymer to the reactor completely separately from the raw material olefin polymer. A method of supplying a commercially available raw olefin polymer in a form in which these higher fatty acids and / or hydrochloric acid absorbents, additives and the like are previously blended.

In the method of the present invention, the olefin polymer is subjected to a thermal decomposition reaction in the presence of the higher fatty acid and / or the hydrochloric acid absorbent and, if necessary, using an additive such as a heat stabilizer. It is a method of obtaining wax.

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

Examples of the tubular pyrolysis apparatus include a single-tube type; a double-tube type including an inner tube through which a reaction mixture flows and an outer tube through which a heating medium flows; a multi-tube type having a plurality of reaction tubes through which a reaction mixture flows. Any type may be used as long as it efficiently heats the reaction mixture flowing therethrough to thermally decompose the olefin polymer.

The tank-type pyrolyzer is usually provided with a stirrer and a heating jacket, but may be provided with an external circulation pump and a heat exchanger in order to further enhance the effects of stirring and heat transfer.

The number of stages of the apparatus may be one or more, and the operation method may be any of a batch type and a continuous type.

Further, the material of the apparatus, particularly the material of the surface with which the reaction mixture comes into contact, is desirably carbon steel, chromium steel, chromium-nickel steel, or high nickel steel such as Incoloy, Hastelloy, or Inconel.

The heating of these pyrolyzers is not limited. For example, any method such as electric heater heating, low frequency induction heating, and heating with a molten salt heat medium may be used.

The feed of the raw olefin polymer to the pyrolyzer is performed by connecting an extruder to the raw material inlet of the pyrolyzer, melting the raw olefin polymer in advance with the extruder, and supplying it to the pyrolyzer. This is preferable in that it can be smoothly supplied to various raw material polymers having different physical properties, and the thermal decomposition reaction can be efficiently performed.

Further, if the atmosphere in the supply path of the raw olefin polymer and the reaction atmosphere in the pyrolysis reactor are inert gas atmospheres, it is effective in improving the quality of the obtained pyrolysis wax.

The reaction conditions in the pyrolyzer may be appropriately selected according to the type and molecular weight of the raw material olefin polymer, the desired molecular weight of the pyrolyzed wax, and the like. For example, the reaction temperature is preferably about 360 to 430 ° C. The reaction pressure is usually about 5 Torr to 50 kg / cm ² G, particularly preferably 500 T
It is about orr to 1.8 kg / cm ² G. The reaction time is about 30 minutes to 3 hours.

<Examples> Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples of the present invention.

(Examples 1 to 3, Comparative Example 1) According to the apparatus shown in Fig. 1, a raw material obtained by adding an additive having a composition shown in Table 1 to 100 parts by weight of polypropylene having an intrinsic viscosity [η] of 1.6 was used. It is supplied from the supply port 11 to the extruder 1, and is continuously supplied to the tubular pyrolyzer 3 equipped with the heating device 2 via the distribution path 12. The production of the pyrolyzed wax is continuously performed for 9 days under the following conditions. I did it. In addition,
In Comparative Example 1, the operation was stopped on the second day.

Extruder Screw diameter: 39.85mm Cylinder diameter: 40.0mm Extruder temperature (temperature at extruder outlet: 300 ° C) Extrusion speed: 10.5kg / hr Tubular pyrolyzer Reaction tube diameter: 50mm Heating temperature: 402 ° C Internal pressure : Normal pressure Residence time: 33 min (based on the amount of raw material supplied) Next, the reaction mixture obtained continuously was subjected to gas-liquid separation to remove volatile components, to produce a pyrolysis wax, and a sample was prepared every operating days. Collected.

The hue and foreign matter content of the pyrolyzed wax samples obtained on each of the operating days were measured according to the following methods. Table 1 shows the results.

Measurement of Hue Powder Hue: The sample was pulverized into powder having an average particle size of about 300 μm, and the hue of the obtained powder was measured with a Hunter Lab color difference meter.

Melt color: The sample was melted at 180 ° C., and the color of the melted sample was compared with a Hazen standard colorimetric liquid in a colorimetric tube.

Foreign matter content Indirectly determined from the L value obtained in the measurement of the powder hue.
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, an olefin polymer is thermally decomposed to obtain a high-quality pyrolyzed wax in terms of hue, foreign matter content, and the like. Since the production can be performed stably for a long time in continuous operation, the industrial practical value is great.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an apparatus used in Examples and Comparative Examples of the present invention. DESCRIPTION OF SYMBOLS 1… Extruder 2… Heating device 3… Tubular pyrolyzer 11… Supply port 12… Distribution channel

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hajime Inagaki 61-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Petrochemical Industry Co., Ltd. (56) References JP-B-43-9368 (JP, B1) (JP) B-151 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 8/50

Claims (1)

(57) [Claims] 1. An olefin polymer is melted in an extruder,
In a pyrolyzer connected to an extruder, in the presence of a hydrochloric acid absorbent or in the presence of a hydrochloric acid absorbent and higher fatty acids,
A method for producing a thermally decomposed wax, comprising a step of heating at a temperature of 0 to 430 ° C. for 30 to 3 minutes to thermally decompose.