JPH04331208A - Production of chlorinated polyolefin - Google Patents

Abstract

PURPOSE:To chlorinate selectively a polyolefin by dissolving the polyolefin in tetrachloroethylene and chlorinating it with chlorine in the presence of a specified amine, a free radical catalyst, etc. CONSTITUTION:At least one member selected from among an alkylamine, an alkanolamide and a nitrogenous heterocyclic amine (e.g. triethylamine or monoethanolamine) and a polyolefin (e.g. polypropylene) are dissolved in tetrachloroethylene at a temperature above the dissolution temperature. Chlorine is fed to the solution in the presence of a free radical catalyst (e.g. benzoyl peroxide) and/or under irradiation. In this way, the polyl olefin can be selectively chlorinated without chlorinating the tetrachloroethylene. The amine used can be replaced by a thiocyanate, a cyclic urea or a cyclic thiourea (e.g. 1,3- dimethyl-2-imidazolinedinone).

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for producing chlorinated polyolefins used as primers, paint vehicles, coating agents, adhesives, binders for printing inks, etc. in coating polyolefin materials. Production of industrially practical and simple chlorinated polyolefin without the risk of ozone layer depletion using tetrachlorethylene without using the previously used carbon tetrachloride solvent that has the risk of ozone layer depletion. It is about law.

0002

BACKGROUND OF THE INVENTION There are many conventional methods for chlorinating polyolefins. As an industrially useful method,

[
A method of chlorinating polyolefin by heating and dissolving it in an organic solvent such as carbon tetrachloride (referred to as an organic solvent method).

[0004] A method of dissolving polyolefin in a small amount of organic solvent and dispersing it in water, or directly dispersing fine particles of polyolefin in water for chlorination (referred to as water suspension method). (USP3281384, Japanese Patent Publication No. 47-1378
No. 0)

A method for producing an α-olefin polymer by reacting a dry powder or granular solid with gaseous chlorine (solvent-free method). (DP.2262535, Special Publication No. 37-6641).

[0006]

[Problems to be Solved by the Invention] Chlorinated polyolefins used in the various applications mentioned above are effective with a relatively low chlorine content of 10-50%, and in these applications, it is possible to improve the uniformity of polyolefins. It is necessary to uniformly and more easily dissolve the compound in a solvent by chlorination, and in this respect, the organic solvent method is the most advantageous method among the above-mentioned methods.

Organic solvents used in the chlorination reaction in the organic solvent method include carbon tetrachloride, halogenated lower aliphatic hydrocarbons such as chloroform, tetrachloroethylene, and methylchloroform, and halogenated aromatic hydrocarbons such as chlorobenzene. There is. Among these, only carbon tetrachloride is essentially inert to chlorine, and the others react with chlorine through substitution reactions and addition reactions. From this point of view, carbon tetrachloride is mostly used industrially. However, because carbon tetrachloride threatens to destroy the ozone layer surrounding the earth, it will be regulated internationally and will no longer be able to be used industrially. There are several examples of using tetrachlorethylene as a solvent in addition to carbon tetrachloride. (For example, USP
．． 2313499, BP. 826495, special public service 1977
-2279. ) However, these have not been put into practical use industrially. The reason for this is that when a solvent inert to chlorine, such as carbon tetrachloride, is used as a solvent for chlorinating polyolefin, usually after the chlorination of the chlorinated polyolefin is completed, steam distillation, drum dryer, extrusion, etc. The solvent used during chlorination is removed by a method such as a chlorination process, and the product is used as a solid product or dissolved in a solvent such as toluene, xylene, or solvent naphtha. Furthermore, the solvent used during chlorination can be recovered and reused without any special process.

However, when tetrachlorethylene is used as a solvent during chlorination of polyolefin, in the conventional chlorination method, chlorination of the solvent tetrachlorethylene occurs as well as chlorination of the polyolefin, and mainly hexachloroethane is chlorinated. Produce in large quantities. This hexachloroethane has a melting point of 187°C, sublimes, and has a strong naphthalene odor. Therefore, when recovering and using tetrachlorethylene, it is necessary to at least distill it and reuse it. Furthermore, if hexachloroethane remains in a chlorinated polyolefin product, it will cause environmental problems such as odor for the user, and it will also have an adverse effect on the physical properties of the chlorinated polyolefin. There is a problem that a removal step is required and the cost is high.

In view of the above, the present invention is an industrially practical method in which when tetrachlorethylene is used as a solvent during chlorination of polyolefin, chlorination of etrachlorethylene hardly occurs and only polyolefin is chlorinated. The object of the present invention is to provide a method for producing chlorinated polyolefin using a simple method.

0010

[Means for Solving the Problems] The first aspect of the present invention is to dissolve a polyolefin in tetrachlorethylene at a temperature higher than its dissolution temperature in the presence of one or more of alkylamines, alkanolamines, and nitrogen-containing heterocyclic amines. This is the production of chlorinated polyolefin in which only the polyolefin is chlorinated while preventing the chlorination of tetrachlorethylene by dissolving it and then introducing chlorine in the presence of a radical catalyst or under light irradiation. 2 is a method for producing a chlorinated polyolein according to the first invention, in which thiocyanates are used in place of the alkylamines, alkanolamines, and nitrogen-containing heterocyclic amines; General formula in place of alkylamines, alkanolamines and nitrogen-containing heterocyclic amines

It is represented by [Chemical formula 2]. (The general formula

(In Formula 2, R1 and R2 are alkyl groups, X is an oxygen or sulfur atom, and n is an integer of 2 to 3). The present invention relates to a method for producing a chlorinated polyolefin according to the first invention using a cyclic urea or a cyclic thiourea.

[0011]

[Chemical 2]

The polyolefins of the present invention include polypropylene, polyethylene, ethylene copolymers such as ethylene-propylene copolymers and ethylene-vinyl acetate copolymers, polypropylene-butene copolymers, polyisobutylene, natural rubber, olefin rubber, etc. It is.

The radical catalyst used in the present invention is a conventional radical generating substance such as benzoyl peroxide,
Organic peroxides such as dialkyl peroxide, ketone peroxide, peroxy ester, dialkyl peroxide, and percarbonate; azo compounds such as azonitrile compounds, azoamideine compounds, cycloazoamideine compounds, azoamide compounds, and alkylazo compounds; There are compounds etc. Further, it is necessary to select one type or a mixture of two or more of these radical catalysts, or a combination of them and a photocatalyst, taking into consideration the reaction temperature and reaction time. The amount of radical catalyst used is 0.05 to 10% by weight based on the polyolefin used. If it is less than 0.05% by weight, there is no effect, and if it is used in excess of 10% by weight, the effect is equivalent to the amount used. cannot be obtained. The photocatalyst used in the present invention may be used alone or in combination with a radical catalyst using light such as natural light, a fluorescent lamp, a chemical lamp, or a UV lamp. The amines used in the present invention include alkyl amines such as triethylamine and diisopropylamine, piperidine, N-methylpiperidine, piperazine, pyridine,
These include nitrogen-containing heterocyclic amines such as N-methylpyrrole, 2-pyrrolidone and morpholine, and alkanolamines such as monoethanolamine and isopropanolamine. The thiocyanates used in the present invention include ammonium thiocyanate and sodium thiocyanate. The cyclic ureas and cyclic thioureas used in the present invention are as described above.

[chemical 2
Cyclic urea and thiourea represented by the general formula shown in the formula, such as 1,3-dimethyl-2-imidazolidinone, 1
-Methyl-3-ethyl-2-imidazolidinone, 1,3
-imidazolidine-2-thione, tetrahalide-1,
3-dimethyl-2pyridinone and the like.

The above-mentioned amines, thiocyanates, cyclic ureas, and cyclic thioureas act as catalysts in the chlorination of polyolefins, and have the effect of suppressing the chlorine addition reaction to tetrachlorethylene. The amount of these used is 5 ppm to 1% by weight, preferably 20% by weight based on the entire reaction solution.
ppm to 1000 ppm. If it is less than 5 ppm, the effect is poor, and if it is used in excess of 1% by weight, the effect corresponding to the amount used cannot be obtained, and on the contrary, it may cause coloring of the reaction solution and a decrease in the reactivity of chlorine with respect to polyolefin. The melting temperature of the polyolefin in the present invention is preferably higher than the melting temperature of the polyolefin used, and especially crystalline polyolefins are desirably melted at a temperature of at least 10° C. or higher than the melting temperature. If chlorine is passed in a state where the polyolefin is not sufficiently dissolved, the reactivity of chlorine with respect to the polyolefin will be reduced, resulting in a non-uniform chlorination reaction. For example, in the case of isotactic polypropylene whose dissolution temperature in tetrachlorethylene is about 104°C, it is desirable to heat and stir under reflux (122°C) for 1 hour.

[0015] The reaction temperature in the present invention is desirably carried out at a temperature higher than the melting temperature of the polyolefin used, usually from 40 to 140°C. At 140°C or higher, chlorine added to the polyolefin is separated by a dehydrochloric acid reaction, resulting in discoloration and chlorine. Reactivity decreases significantly. In addition, as the chlorination progresses, the dissolution temperature of the chlorinated polyolefin that is produced decreases, so it is possible to gradually lower the reaction temperature as the chlorination progresses, or to perform chlorination by lowering the reaction temperature in stages. be.

[0016]

【Example】

Example 1 105.3 parts by weight of isotactic polypropylene (number average molecular weight 15,000) and 0.3 parts by weight of isotactic polypropylene (number average molecular weight 15,000).
05 parts by weight of ammonium thiocyanate to 947.3 parts by weight
parts by weight of tetrachlorethylene. 12 under reflux
The mixture was strongly stirred at 2° C. for 1 hour to sufficiently dissolve the isotactic polypropylene. Lower the solution temperature to 105 °C,
4.2 parts by weight of t-butyl-peroxybenzoate were added and 135.2 parts by weight of chlorine gas were introduced at a rate of 0.6 parts by weight/min. After introducing a predetermined amount of chlorine gas, a ripening reaction was performed at the same temperature for 5 minutes, and the mixture was cooled to room temperature. Gas chromatographic analysis of the obtained tetrachloroethylene solution of chlorinated polypropylene (chlorine content: 36.7% by weight) revealed that the amount of hexachloroethane produced was 0.0 part by weight.

[0017]

Example 2 Chlorination was carried out in exactly the same manner as in Example 1 except that 0.05 parts by weight of ammonium thiocyanate was replaced with 0.08 parts by weight of 1,3-dimethyl-2-imidazolidinone. The obtained chlorinated polypropylene (chlorine content 36
．． As a result of gas chromatographic analysis of a 3% by weight tetrachlorethylene solution, the amount of hexachloroethane produced was 0.0 part by weight.

[0018]

Example 3 Chlorination was carried out in the same manner as in Example 1 except that 0.05 parts by weight of ammonium thiocyanate was replaced with 0.08 parts by weight of monoethanolamine. The obtained chlorinated polypropylene (chlorine content 36.7% by weight)
) was subjected to gas chromatography analysis, and the amount of hexachloroethane produced was 0.0 parts by weight.

[0019]

[Comparative example]

[Comparative Example 1] Chlorination was carried out in exactly the same manner as in Example 1 except that ammonium thiocyanate was not added. Gas chromatographic analysis of the obtained tetrachlorethylene solution of chlorinated polypropylene (chlorine content: 35.9% by weight) revealed that the amount of hexachloroethane produced was 2.6 parts by weight.

[0020]

【Example】

Example 4 105.3 parts by weight of isotactic polypropylene (number average molecular weight 15,000) and 0.3 parts by weight of isotactic polypropylene (number average molecular weight 15,000).
0.8 parts by weight of monoethanolamine were added to 947.5 parts by weight of tetrachlorethylene. Under reflux 122
The mixture was strongly stirred at ℃ for 1 hour to sufficiently dissolve the isotactic polypropylene. Lower the solution temperature to 115°C, 1.
Add 1 part by weight of dicumyl peroxide, and add 0.3 parts by weight of dicumyl peroxide.
135.2 parts by weight of chlorine gas were introduced at a rate of parts by weight/min. After introducing a predetermined amount of chlorine gas, a ripening reaction was carried out at the same temperature for 5 minutes, and the mixture was cooled to room temperature. Gas chromatographic analysis of the resulting tetrachlorethylene solution of chlorinated polypropylene (chlorine content: 37.0% by weight) revealed that the amount of hexachloroethane produced was 0.0 part by weight.

[0021]

[Comparative example]

Comparative Example 2 Chlorination was carried out in the same manner as in Example 4 except that monoethanolamine was not added. Obtained chlorinated polypropylene (chlorine content 36.6% by weight)
As a result of gas chromatographic analysis of the tetrachlorethylene solution, the amount of hexachloroethane produced was 5.
．． It was 4 parts by weight.

As is clear from the above, when comparing Examples 1 and 2 with Comparative Example 1 regarding the amount of hexachloroethane produced by chlorinating tetrachlorethylene, ammonium thiocyanate, 1,3
-Dimethyl-2-imidazolidinone clearly has an effect of addition, and from the comparison of Example 3 and Comparative Example 1 and the comparison of Example 4 and Comparative Example 2, it is clear that monoethanolamine has an effect of addition. It also clearly prevents chlorination of tetrachlorethylene.

[0023]

[Effects of the Invention] The effects of the present invention can be summarized as follows.

Conventionally, when polyolefin was chlorinated using tetrachlorethylene as a solvent, chlorination of tetrachlorethylene occurred along with chlorination of polyolefin.
Mainly hexachloroethane is produced. The present invention is capable of chlorinating tetrachlorethylene by containing one or more of alkylamines, alkanolamines, nitrogen-containing heterocyclic amines, thiocyanates, cyclic ureas, or cyclic thioureas. It is possible to uniformly chlorinate only the polyolefin.

The present invention hardly generates hexachloroethane, which is a chlorinated product of tetrachlorethylene, and unlike conventional methods, the recovered tetrachlorethylene can be reused without distillation, and hexachloroethane This is a simple and industrially practical method for producing chlorinated polyolefins, as there is no need for a step to remove .

Due to its uniform solubility in solvents, the chlorinated polyolefin obtained in the present invention can be used as a primer in coating polyolefin materials, as a paint vehicle, as a coating agent, as an adhesive, and as a printing ink. Used for binders, etc.

Claims (3)

[Claims] Claim 1: A polyolefin is dissolved in tetrachlorethylene at a temperature higher than its dissolution temperature in the presence of one or more of alkylamines, alkanolamines, or nitrogen-containing heterocyclic amines, and then irradiated with light under a radical catalyst. A method for producing a chlorinated polyolefin, which comprises suppressing the chlorination of tetrachlorethylene and chlorinating only the polyolefin by introducing chlorine under the conditions or under the combined use of a radical catalyst and light irradiation. 2. The method for producing a chlorinated polyolefin according to claim 1, wherein a thiocyanate is used in place of the alkylamines, alkanolamines or nitrogen-containing heterocyclic amines. 3. The chlorine according to claim 1, wherein a cyclic urea or a cyclic thiourea represented by the general formula [Chemical formula 1] is used instead of the alkylamines, alkanolamines or nitrogen-containing heterocyclic amines. Method for producing chemically modified polyolefins. In addition, in the general formula [Formula 1], R1 and R2 are lower alkyl groups,
X represents an oxygen or sulfur atom, and n represents an integer of 2 to 3. [Chemical formula 1]