JPH0436302A - Preparation of chlorinated polyolefin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing a chlorinated polyolefin having excellent corrosion resistance.

[Prior art and problems to be solved by the invention] 55 to 75% chlorinated polyolefins have long been known to be useful as raw materials for heavy-duty anti-corrosion paints, and are mainly chlorinated in chlorinated solvents and then It has been manufactured by processing methods such as steam distillation, direct spraying, and solvent conversion. Since such chlorinated products are uniformly chlorinated, they are characterized by being uniformly dissolved in organic solvents.

However, in recent years, the use of chlorinated solvents has been restricted due to global environmental issues, and chlorination in an aqueous medium is being considered as an alternative in the production of chlorinated polyolefins.

A method of chlorinating a polyolefin in an aqueous dispersion state or an emulsion state in an aqueous medium is known. When polyolefin is chlorinated to a chlorine concentration of about 20 to 50% in order to convert the crystalline state of rubbery polyolefin,
Chlorination is carried out in an aqueous dispersion system, using anti-aggregation agents such as various surfactants, and strictly regulating the melting point and reaction temperature of the polyolefin (Japanese Patent Publication No. 1983-
60403, JP-A-63-128005, etc.).

A method is also known in which polyolefin with a molecular weight of 15,000 or more is made into fine particles and chlorinated in an aqueous suspension (
(Japanese Patent Publication No. 40-15660), this chlorinated product does not dissolve uniformly in ordinary organic solvents, making it difficult to use as a heavy-duty anticorrosive paint.

On the other hand, polymer polyolefin and oxidized polyolefin wax were melt-mixed, poured into an alkaline aqueous solution, and finely powdered into spherical particles.
The following method of chlorination has also been proposed (Special Public Interest Publication No. 58
-12883), this chlorinated product is insoluble in toluene, which is a common organic solvent.

As described above, by the conventional method of chlorinating polyolefin in an aqueous medium, it has not been possible to efficiently obtain a chlorinated polyolefin suitable as a raw material for a paint.

An object of the present invention is to provide a method for uniformly chlorinating a highly chlorinated polyolefin soluble in an organic solvent, which can be used as a heavy-duty anti-corrosion paint, in an aqueous medium without fear of particle aggregation. .

[Means for Solving the Problems] The method for producing a chlorinated polyolefin of the present invention is to produce a fine particulate low molecular weight polyolefin having a molecular weight of 500 to 15,000, a softening point of 85 to 140°C, and an average particle size of 0.1 to 200μ. is dispersed in water and chlorinated at a temperature of 0 to 50°C to a chlorine concentration of 55 to 75%.

The raw material polyolefin used in the present invention includes homopolymers or copolymers of olefinically unsaturated hydrocarbons. The above homopolymers include ethylene, propylene, butene-1, methylpentene-1, hexene-1,
There are homopolymers of monomers such as 1 and octene-1.

Examples of the copolymers include copolymers of these seven monomers, such as ethylene-propylene copolymers, or copolymers of these monomers with unsaturated carboxylic acid esters, vinyl acetate, and the like. Furthermore, copolymers modified by air oxidation of the above copolymers, maleic acid, maleic anhydride,
A copolymer modified with an acid such as itaconic acid can also be used.

The molecular weight of the raw material polyolefin of the present invention is 500 to 150
00, preferably 1000 to 7000, if the molecular weight is too low, initial fusion tends to occur during chlorination in an aqueous medium. If the molecular weight is too high, agglomeration tends to occur when it becomes a highly chlorinated product. All chlorinated products are unsuitable as raw materials for paints.

The softening point of the raw material polyolefin of the present invention is 85 to 140°C
It is. When the temperature is lower than 85°C, fusion tends to occur during chlorination in an aqueous medium. If the temperature exceeds 140°C, the chlorinated product becomes brittle and is not suitable for paints.

The average particle diameter of the raw material polyolefin of the present invention is 0.1 to 2
It is 00μ. If it is less than 0.1μ, as chlorination progresses, the whole becomes jelly-like and coagulates into agglomerates.

When it exceeds 200μ, only chlorination of the particle surface progresses,
The entire process becomes non-uniform, resulting in a chlorinated product that is not uniformly soluble in organic solvents.

Examples of methods for making the raw material polyolefin of the present invention into fine particles include a mechanical pulverization method, a solvent precipitation method, and a melt quenching method. In addition, it may be produced by emulsion polymerization or suspension polymerization and solidified in a fine particle state.

In the present invention, the above raw material polyolefin is dispersed in water and chlorinated. At this time, the raw material polyolefin concentration in the aqueous phase is less than 30% by weight (preferably less than 10% by weight, more preferably 5% by weight). It is desirable to adjust it so that it is less than Furthermore, upon dispersion into the aqueous phase,
Suspension stabilizers such as polyoxyethylene polyoxypropylene condensate, polyoxyalkylene alkyl ether, polyoxyalkylene nonylphenyl ether, solhitan fatty acid ester, and Nonionic surfactants such as oxyalkylene sorbitan fatty acid esters and polyoxyalkylene glycerin fatty acid esters (preferably those with a B of 11 or more), higher alcohol sulfates, alkylbenzene sulfonates, alkyl phosphate salts, polyoxyalkylene alkyl sulfates Anionic surfactants such as , dialkyl sulfosuccinates can be used.

The amount of the suspension stabilizer used is 0.1 to 7 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the raw material polyolefin. If it is less than 0.1 part by weight, the stability of the suspension will be poor, and if it exceeds 7 parts by weight, it will adversely affect the chlorination in the subsequent step, causing particles to aggregate or forming a non-uniform chlorinated product, which is not preferable.

The chlorination of the present invention is carried out at a chlorination temperature of 0 to 50°C, 0°C.
If it is less than 50°C, problems such as freezing of the medium will occur, and if it exceeds 50°C, fusion of the polymer will occur during moderate chlorine addition.

The chlorination of the present invention is carried out until the chlorine concentration of the chlorinated product is 55 to 75%. If it is less than 55%, even if it is uniformly chlorinated, it will have poor solubility in organic solvents such as toluene or xylene, making it impossible to obtain a homogeneous solution, and if it exceeds 75%, the chlorinated substance itself will dissolve into the organic solvent. Becomes insoluble.

In the chlorination of the present invention, chlorine can be effectively utilized by using a radical initiator or by performing it under ultraviolet irradiation. Further, the supply of chlorine may be either a feed type or a closed type, and may be under normal pressure or under pressure.

[Effects of the invention] The chlorinated polyolefin obtained by the production method of the present invention has
It dissolves uniformly in organic solvents and is extremely useful as a raw material for heavy duty anticorrosion paints.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Molecular weight 3000, density 0.93g/cr1 by viscosity method
, Softening point 114℃ (JIS K-2207), Acid value 1
．． θ■KOH/g1 Polyethylene 3 with average particle size 30μ
5g, sodium stearate 0.35g, water 658g,
A cylindrical reaction tank with a capacity of 1 liter, equipped with a stirrer, a thermometer, a chlorine feed nozzle, and capable of being irradiated with ultraviolet rays from the outside using a mercury lamp was installed, and chlorine gas was supplied at a rate of 50 g/hour while stirring at a temperature of 20°C. I blew it in.

After chlorination in this manner for 6 hours, the particles were separated by filtration, washed with water and dried under reduced pressure at 50°C.

No fusion of particles was observed during the reaction, and the product remained particulate even after filtration and drying. The chlorine concentration of the dried chlorinated product was 68%, and a 20% toluene solution of this product and a film obtained by applying the same solution to glass and drying were also uniformly transparent.

Example 2 Molecular weight 1500, density 0.93 g/d by viscosity method
, Softening point 108℃ (JIS K-2207), Acid value 1
5.8 ■KOH/g, average particle size 80 μ, ethylene/propylene molar ratio = 9515 35 g of ethylene propylene copolymer 1 sodium stearate 0.35 g, water 658 g, volume IIl, stirrer, temperature The reactor was placed in a cylindrical reaction tank equipped with a chlorine feed nozzle and capable of being irradiated with ultraviolet rays from the outside using a mercury lamp, and chlorine gas was blown into the reactor at a rate of 50 g/hour while stirring at a temperature of 25°C.

After chlorination in this manner for 6 hours, the particles were separated by filtration, washed with water and dried under reduced pressure at 50°C.

No fusion of particles was observed during the reaction, and the product remained particulate even after filtration and drying. The chlorine concentration of the dried chlorinated product was 62%, and a 20% toluene solution of this product and a film obtained by applying the same solution to glass and drying were also uniformly transparent.

Example 3 Molecular weight 3500, density 0.93 g/c by viscosity method
Fl! , Softening point 102℃ (JIS K-2207),
Acid value 15.8■KO! (7g, 35g of maleic anhydride-modified oxidized polyethylene with an average particle size of 80μ, nonionic surfactant Adekanol NP-900 (ethylene oxide/propylene oxide block copolymer, HL
B=19) 0.7g, water 658@! , the volume is 1! in,
The reactor was placed in a cylindrical reaction tank equipped with a stirrer, a thermometer, and a chlorine feed nozzle and capable of being irradiated with ultraviolet rays from the outside using a mercury lamp, and chlorine gas was blown into the reactor at a rate of 50 g/hour while stirring at a temperature of 40°C.

After 5 hours of chlorination in this manner, the particles were separated by filtration, washed with water and dried under reduced pressure at 50°C.

No fusion of particles was observed during the reaction, and the product remained particulate even after filtration and drying. The chlorine concentration of the dried chlorinated product was 65%, and a toluene solution of this product and a film obtained by applying a solid liquid to glass and drying it were also uniformly transparent.

Comparative Example 1 Molecular weight by viscosity method: 3000, density: 0.93 g/d, softening point: 114°C (JIS K-2207), acid value: 1.0
■KOH/g, polyethylene 35 with average particle size 400μ
g, 0.35 g of sodium stearate, and 658 g of water were charged into a cylindrical reaction tank having a volume of IIl, equipped with a stirrer, a thermometer, and a chlorine feed nozzle, and capable of being irradiated with ultraviolet rays from the outside using a mercury lamp. While stirring at 0.degree. C., chlorine gas was blown in at a rate of 50 g/hour.

After 1 hour of chlorine feed, the system became a large lump. A portion of this sample was washed with water and dried under reduced pressure at 50° C. The chlorine concentration of the sample was 25%, and the 20% toluene solution was cloudy and non-uniform.

Next, a paint was prepared using the following formulation using the chlorinated polyolefin of the present invention obtained in Examples 1 to 3, and applied to a mild steel plate under the following coating and drying conditions.The physical properties were evaluated.The results are as follows. It is shown in Table 1.

For comparison, chlorinated polyethylene (ADEKAPREN CB-505: molecular weight 2000, density 0.93 g/cd, softening point 114°C (J
IS-2207), acid value 1. Table 1 also shows the results of a similar evaluation using θ■KOH/g, chlorine concentration 64%).

<Paint formulation> Application and drying conditions> ■5PCC-3B (JIS G-3141) mild steel plate used (0.6 x 50 x t5o; "280 grind Wj)
■M board cleaning; Chloroform and toluene cleaning ■Coating;
Baa Kota-050 (0,05 kaku) ■Drying; 48
Hr room temperature setting = +60℃
Spontaneous) January 30, 1991 1. Indication of the case Japanese Patent Application No. 2-143502 2. Name of the invention Process for producing chlorinated polyolefin 3. Person making the amendment Relationship to the case Patent applicant Asahi Denka Kogyo Co., Ltd. 4. Agent (1) Page 2 of the specification, lines 9-10 “Chlorine concentration 20-50%”
"Chlorine content 20-50% (by weight, same below)"
Corrected.

(1) Page 3, line 4, page 4, line 2, page 7, line 10, page 9, lines 2-3
line, last line of page 9 to line 1 on page 10, line 2 to 1 from the bottom of page 10, 1
“Chlorine concentration” on page 1, line 15, and page 12, line 6, were corrected to “chlorine content”.

Claims and details of the invention 2 of the specification subject to 5° amendment, Claims Molecular weight is 500 to 15,000, Softening point is 85 to 140
Production of a chlorinated polyolefin characterized by dispersing fine particulate low molecular weight polyolefin with an average particle size of 0.1 to 200 μ in water at 0 to 50 °C, and chlorinating it to 1155 to 7511% chlorine. Method.

Claims (1)

[Claims] Molecular weight 500-15000, softening point 85-140℃
A method for producing a chlorinated polyolefin, characterized in that fine particulate low molecular weight polyolefin with an average particle diameter of 0.1 to 200 μ is dispersed in water and chlorinated at 0 to 50° C. to a chlorine concentration of 55 to 75%. .