JPH0361683B2 - - Google Patents

Description

[Detailed description of the invention]

[] Object of the Invention The present invention relates to a novel method for producing polyethylene. More specifically, the chlorine content of the special ethylene and α-olefin copolymer is 20 to 55% by weight.
, and the Mooney viscosity at a temperature of 100°C is 10
In producing chlorinated polyethylene in an aqueous suspension state, which has a peak attributable to amorphous matter with a Black angle 2θ of 8 to 15 degrees by X-ray wide-angle diffraction, the second step is the first step. chlorination at a temperature higher than the chlorination temperature in the second stage, but lower than the melting point of the copolymer of ethylene and α-olefin used, and then a third stage at a temperature higher than the chlorination temperature in the second stage. The present invention relates to a method for producing chlorinated polyethylene, which is characterized by chlorination at a low temperature, and its purpose is to provide chlorinated polyethylene that has excellent processability. [] Background of the Invention Chlorinated polyethylene, which is currently industrially produced and used in a wide range of fields, is obtained by chlorinating crystalline ethylene polymers, and has excellent weather resistance, It has excellent flame resistance, chemical resistance and heat aging resistance, and also has an extremely good filler mixing capacity. In particular, chlorinated polyethylene, which has a relatively large molecular weight, has a considerable mechanical strength even when unvulcanized, and therefore has a wide range of applications. In order to take advantage of these favorable properties, research has been widely conducted on the use of chlorinated polyethylene in various fields. However, when this chlorinated polyethylene is molded and used for various purposes, it has a high Mooney viscosity and poor processability. There were natural restrictions on its use. [] Structure of the Invention Based on the above, the present inventors have conducted various searches to obtain chlorinated polyethylene with excellent processability without losing the properties of chlorinated polyethylene, and as a result, they have found that the density is 0.905 to 0.940 g. / ^cm3 , and the melting point is 106~
The temperature is 130℃, and the melt index (JIS K-
According to 6760 the temperature is 180℃ and the load is 2.16
Measured under Kg conditions, hereinafter referred to as "MI") is 0.01~
100 g/10 minutes, and the number of side chain alkyl groups having 1 to 10 carbon atoms is substantially 3 per 1000 main chain carbon atoms.
~35 Copolymers of ethylene and alpha-olefins have a chlorine content of 20-55% by weight and a Mooney viscosity of 10 in a small rotor at a temperature of 100°C.
In producing chlorinated polyethylene in an aqueous suspension state, which has a peak attributable to amorphous matter with a Black angle 2θ of 8 to 15 degrees by X-ray wide-angle diffraction method, (A) First step 20 to 60% of the total chlorination amount is chlorinated at a temperature at least 10°C lower than the melting point of the copolymer of ethylene and α-olefin used in the production of chlorinated polyethylene, and then (B) in the second step. The temperature is 5°C higher than the degree of chlorination in the first step, but 5°C higher than the melting point of the copolymer of ethylene and α-olefin.
chlorination at a temperature ~15°C lower (C) by chlorinating at least 10% of the total chlorination amount in the third stage at a temperature between 5 and 15°C lower than the chlorination temperature in the second stage; The present invention was achieved by discovering that a uniform chlorination reaction can be carried out without agglomeration. [] Effects of the Invention The production method of the present invention exhibits the effect that there is no agglomeration between particles during the reaction, and the chlorination reaction proceeds uniformly. Furthermore, the chlorinated polyethylene thus obtained has the following characteristics. (1) Low Mooney viscosity. (2) It has excellent workability, so it is easy to work with. (3) Good mechanical strength. (4) Excellent weather resistance, flame resistance, and heat resistance. (5) Good fluidity. (6) Sticking (blocking) between particles is less likely to occur during storage. As described above, since the chlorinated polyethylene obtained by the production method of the present invention has excellent characteristics, it can be used in a wide variety of fields. Typical uses are shown below. (1) Parts of complex electrical equipment, mechanical parts (2) Solvent-type adhesive [] Detailed description of the invention (A) Raw material polyethylene The density of polyethylene, which is the raw material for the chlorinated polyethylene of the present invention, is 0.905 to 0.940 g. /cm, preferably 0.905 to 0.930g/ ^cm3 , especially 0.910g/cm3
~0.930 g/cm ³ is suitable. Density is 0.905g/
When chlorinated polyethylene is produced using polyethylene of cm ³ or less, not only does the mechanical strength of the chlorinated polyethylene decrease significantly, but
The product is sticky and cannot be obtained in good quality. On the other hand, when polyethylene of 0.940 g/cm ³ or more is used, the resulting chlorinated polyethylene has a high Mooney viscosity and poor fluidity, which limits its range of use. In addition, the melting point of the raw material polyethylene is 106 to 130℃, and especially
A temperature of 108 to 123°C is desirable. When polyethylene with a melting point of 106° C. or lower is chlorinated, the resulting chlorinated polyethylene has poor reaction efficiency during production and is subject to severe agglomeration between particles. On the other hand, when polyethylene with a temperature of 130° C. or higher is used, the resulting chlorinated polyethylene has a high Mooney viscosity and poor fluidity, resulting in poor workability during processing.
Furthermore, the MI of this polyethylene is 0.01~100
g/10 minutes, particularly preferably 0.1 to 20 g/10 minutes. When chlorinated polyethylene is produced using polyethylene with an MI of 0.01 g/10 minutes or less,
The chlorinated polyethylene has very good mechanical strength, but on the other hand, it has a high Mooney viscosity and poor fluidity, so it has poor workability during processing. On the other hand, when 100 g/10 minutes or more of polyethylene is used, the resulting chlorinated polyethylene not only has poor reaction efficiency during production, but also has significantly reduced mechanical strength. On top of that,
Due to its low Mooney viscosity, it becomes extremely sticky during processing. In addition, the side chain of polyethylene used as a raw material is essentially an alkyl group having 1 to 10 carbon atoms, and the number of alkyl groups in the side chain is 3 to 35 per 1000 carbon atoms in the main chain, Generally 6~
There are 30 pieces. If the number of alkyl groups in the side chain is less than 3 per 1000 carbon atoms in the main chain, the reaction efficiency during the chlorination reaction will be poor. On the other hand, if the number of alkyl groups in the side chain is 35 or more, it is difficult to obtain powdered raw material polyethylene, and the chlorination reaction cannot be carried out uniformly when producing chlorinated polyethylene. This polyethylene is a so-called Ziegler catalyst obtained from a transition metal compound (e.g., titanium tetrachloride) as the main catalyst and an organometallic compound (e.g., an alkyl aluminum compound) as a co-catalyst or a chromium oxide supported on a carrier. Phillips
In the presence of a catalyst, ethylene and carbon number at most 12
It can be obtained by copolymerizing with α-olefin. Representative examples of this α-olefin include propylene, butene-1, hexene-1,
Mention may be made of octene-1 and 4-methylpentene-1. (B) First stage chlorination The first to third stage chlorination is carried out in aqueous suspension. To carry out the chlorination in the form of an aqueous suspension, the above-mentioned copolymer of ethylene and α-olefin in the form of particles or powder is suspended in an aqueous medium. In order to maintain this aqueous suspension state, it is preferable to add a small amount of emulsifier or suspending agent. At this time, radical generators such as benzoyl peroxide, azobisisobutyronitrile and hydrogen peroxide, antifoaming agents such as light silicone oil, and other additives may be added as necessary. In the first stage, the chlorination is carried out at a temperature at least 10 DEG C. below the melting point of the copolymer of ethylene and alpha-olefin used. In particular, it is preferable to carry out the chlorination at a temperature 20 to 40°C lower than the melting point of the copolymer. When chlorination is carried out at a temperature 10°C or more lower than the melting point of the copolymer, no agglomeration of particles occurs during the reaction, and the subsequent second stage chlorination can be easily carried out. On the other hand, when chlorination is carried out at a low temperature of 10°C or less, particle agglomeration tends to occur during the reaction, making it difficult to continue the reaction, and the resulting product is also non-uniform. It has a chlorination degree distribution. In addition, in this first stage, the total amount of chlorination is
20-60% chlorination is required (e.g.
When producing the chlorinated polyethylene of the invention with a chlorine content of 30% by weight, in this first step a chlorinated polyethylene with a chlorine content of 8 to 20% by weight must be produced), in particular 30 to 20% by weight).
60% chlorination is preferred. If less than 20% of the total chlorination amount is chlorinated at this stage, agglomeration of particles is likely to occur during the subsequent second stage chlorination reaction. On the other hand, if chlorination is carried out by more than 60%, the chlorination will proceed unevenly and the resulting product will have poor heat resistance and processability. After carrying out the chlorination in the first stage in this manner, the chlorinated polyethylene of the present invention can be produced by carrying out the chlorination in the second stage under the following conditions. In transitioning from the first stage chlorination to the second stage chlorination, the second stage chlorination may be carried out by changing the conditions in the reactor used in the first stage chlorination, or the second stage chlorination may be carried out in advance. The aqueous suspension containing the chlorinated polyethylene produced by the first stage chlorination may be transferred to another reactor controlled to the conditions of the second stage chlorination. (C) Second-stage chlorination The second-stage chlorination temperature is 5°C or more higher than the first-stage chlorination temperature, but 5°C higher than the melting point of the copolymer of ethylene and α-olefin used. This can be accomplished by carrying out the remaining chlorination at a temperature ~15°C lower. In particular, the temperature is at least 10°C higher than the chlorination temperature in the first stage, but 5 to 10°C higher than the melting point of the copolymer.
It is desirable to carry out the test at a temperature as low as ℃. If the second stage chlorination is carried out at a temperature lower than the melting point of the copolymer by 5° C. or less, uniform chlorination will not occur and the processability and heat resistance of the resulting chlorinated polyethylene will be poor. On the other hand, when carried out at a temperature 15°C or more lower than the melting point of the copolymer used,
The resulting product has a non-uniform chlorination degree distribution and has poor processability and heat resistance. In addition, it is desirable to chlorinate 40 to 85% of the total chlorination amount in the first stage and this second stage, and it is particularly preferable to chlorinate 45 to 85% of the total chlorination amount. (D) Third stage chlorination The second stage chlorination can be achieved by chlorinating at a temperature 5 to 20°C lower than the second stage chlorination temperature. In particular, it is desirable to carry out the chlorination at a temperature 8 to 15°C lower than the second stage chlorination temperature. If the third stage chlorination is carried out at a temperature 5° C. or more lower than the second stage chlorination temperature, the product is susceptible to blocking during storage. on the other hand,
If the chlorination temperature is 20°C or more lower than the second stage chlorination temperature, the chlorination will proceed unevenly and the resulting product will have poor heat resistance and processability. In this third stage, it is necessary to chlorinate at least 10% of the total chlorination amount. In particular, it is preferable to chlorinate 15% or more of the total chlorination amount. If less than 10% of the total chlorination amount is chlorinated at this stage, the resulting product will be susceptible to blocking during storage. In the above-mentioned first to third stage chlorination, chlorine can be used alone in gaseous form or diluted with an appropriate inert gas. In this case, the chlorine introduction pressure is usually 5 kg/cm ² or less. The progress of chlorination can be determined by measuring the weight loss of the supplied chlorine, but the degree of chlorination can also be determined by measuring the amount of chlorine hydrogen produced. The chlorinated polyethylene thus obtained can be washed with water to remove attached hydrochloric acid, emulsifier, etc., and then dried to produce the chlorinated polyethylene of the present invention. (E) Physical properties, mechanical properties, etc. of chlorinated polyethylene The chlorine content of the chlorinated polyethylene thus obtained is 20 to 55% by weight (preferably 25% by weight).
~50% by weight, preferably 25-45% by weight). The chlorine content of this chlorinated polyethylene is 20
Below % by weight, there are problems in recovering and purifying the resulting chlorinated polyethylene. Moreover, it has poor flame resistance. On the other hand, if the amount is 55% by weight or more, the resulting chlorinated polyethylene is unfavorably degraded in thermal stability and heat resistance. Furthermore, the flow rate of the chlorinated polyethylene of the present invention (according to JIS K-6760)
(Measured under conditions of 21.6Kg and salinity of 180℃) is
Generally 1 to 100g/10 minutes, especially 5
~80g/10 minutes is preferable. The Mooney viscosity of the chlorinated polyethylene obtained as described above is 10 to 60 points in a small rotor at a temperature of 100°C. Also,
It has the following features due to the X-ray wide-angle diffraction method. FIG. 1 shows the obtained X-ray wide-angle diffraction pattern. X
Cu-Ka radiation (wavelength 1.54 Å) was used as a radiation source (transmission method). When the obtained diffraction curve is blotted at 2θ, for the chlorinated polyethylene obtained in Example 1, a diffraction peak due to amorphousness is observed near a Bratz angle 2θ of 12°, as shown by the dotted line b in Figure 1. shows. This peak value 2θ varies depending on the degree of chlorination of the obtained chlorinated polyethylene, but when the chlorine content is in the range of 20 to 55% by weight,
2θ is in the range of 8 to 15°. Further, the solid line a in FIG. 1 shows the diffraction pattern of polyethylene used as a raw material in Example 1.
Polyethylene crystal diffraction surface has 2θ of 21℃ (110)
The (200) plane is seen at 2θ of 24°, and an amorphous peak due to amorphousness is observed near 2θ of 19°.
As is clear from the chlorination of polyethylene, the 2θ due to amorphousness shifts from 19° to 8-15° (12° in Example 1). Typical properties of the chlorinated polyethylene of the present invention are shown below. The density is 1.10-1.30 g/ ^cm3 . Also, JIS
In the tensile test measured according to K-6301, the tensile strength at break is 5 to 100 g/cm ³ and the tensile elongation at break is 800 to 2500%. Furthermore, the hardness (Shoer A) is 30 to 60, and the volume resistivity (measured according to ASTM D-254) is 1.0 × 10 ¹³ to
It is 9.9×10 ¹⁴ Ω・cm. (F) Processing and molding method When processing and molding the chlorinated polyethylene of the present invention, lubricants, colorants, antistatic agents, fillers, oxygen, light and heat, which are generally added to chlorinated polyethylene, are used. Additives such as stabilizers may also be included. In addition, commonly used chlorinated polyethylene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, binary or tertiary copolymer rubber containing ethylene and propylene as main components, chloroprene rubber, chlorosulfonate rubber, etc. Rubber-like products such as polyethylene rubber, butadiene homopolymer rubber, and natural rubber, as well as polyvinyl chloride, olefin resins based on ethylene and/or propylene, and methyl methacrylate resins based on methyl methacrylate. , acrylonitrile-styrene copolymer resin and a resinous material such as a graft polymer obtained by graft polymerizing at least one of a vinyl compound such as styrene, acrylonitrile, and methyl methacrylate to the rubbery material may be blended. good. When producing these compositions, the blending (mixing) method may be to use mixers commonly used in the art, such as open rolls, dry blenders, Banbury mixers, and kneaders. Among these mixing methods, in order to obtain a more uniform composition, two or more of these mixing methods may be applied (for example, after mixing with a dry blender, the mixture may be mixed using an oven roll. how to). Among these mixing methods,
To mix chlorinated polyethylene and rubbery material, the mixing temperature is 30-120℃, usually 50-100℃
It is ℃. In particular, during mixing, rubber-like materials generate heat due to cohesive force, so the mixing temperature is set at 150°C.
It is desirable to control the temperature below ℃. In addition, to mix chlorinated polyethylene and resinous material,
It is preferably carried out at a temperature above the temperature at which they melt, but below 180°C. The chlorinated polyethylene of the present invention and compositions thereof can be manufactured using molding machines such as extrusion molding machines, injection molding machines, compression molding machines, compression molding machines, and calender molding machines that are commonly used in the general rubber industry and resin industry. It is then molded into a desired shape and used. In addition, when molding only chlorinated polyethylene, the molding temperature is 70~
130°C, generally 90-120°C. [] Examples and Comparative Examples The present invention will be explained in more detail below using Examples. In addition, in the examples and comparative examples, the tensile test was conducted in accordance with JIS K-6301, and the tensile speed was 500 mm/
Measurements were made under the following conditions (JIS No. 3 dumbbells were used). The hardness was determined using LIS hardness (Short A), and the test piece was measured using a hardness meter using three JIS No. 3 dumbbells stacked on top of each other in accordance with JIS K-6301. Furthermore, Mooney viscosity is JIS K-
The 4-minute value was measured using a small rotor at a temperature of 100°C and a preheat of 1 minute according to 6301. Furthermore, the flow rate (hereinafter referred to as "FR") was measured according to JIS K-6760 at a temperature of 180° C. and a load of 2.16 kg. Example 1 880 in a 100 glass-lined autoclave
of water, 80 g of sodium laurate, and an ethylene-butene-1 copolymer (density:
0.921g/cm ³ , number of alkyl groups per 1000 carbon atoms in the main chain: 6, MI 2.0g/10min, melting point 120
10 kg of copolymer was charged and chlorinated with stirring in a temperature range of 50 to 100°C until the chlorine content of the copolymer reached 20.2% by weight (first stage chlorination).
Then, the reaction system was heated and chlorinated in a temperature range of 110 to 115°C until the chlorine content reached 32.0% by weight (second stage chlorination). Next, the reaction system is cooled and chlorinated in a temperature range of 100 to 105°C until the chlorine content reaches 40.3% by weight (third stage chlorination) to produce chlorinated polyethylene [hereinafter referred to as "CPE(A)"]. was manufactured. Example 2 Ethylene-butene-1 used in Example 1
Instead of a copolymer, an ethylene-butene-1 copolymer with a melting point of 118°C (MI 20 g/10 min, number of alkyl groups per 1000 carbon atoms in the main chain: 7,
The first step of chlorination was carried out under the same conditions as in Example 1, except that the density was 0.922 g/cm ³ ). Then, the chlorine content in the temperature range of 108-113℃
It was chlorinated to 31.2% by weight (second stage chlorination). Furthermore, chlorination was carried out in the same temperature range as in the third stage chlorination of Example 1 to produce chlorinated polyethylene (hereinafter referred to as "CPE(B)") having a chlorine content of 41.1% by weight. Comparative Example 1 Ethylene-butene used in Example 1
1 copolymer, an ethylene-butene-1 copolymer (density 0.945 g/cm ³ ,
Example 1 except that HLMI 5.0g/10min) was used.
The first stage of chlorination was carried out in the same manner as (degree of chlorination).
20.2% by weight). Next, chlorination was carried out in the temperature range of 120 to 125°C to produce chlorinated polyethylene with a chlorine content of 32.0% by weight, and then chlorination was carried out in the same temperature range as the third stage chlorination in Example 1 to produce chlorine-containing polyethylene. Chlorinated polyethylene (hereinafter referred to as "CPE(C)") with a percentage of 40.2% by weight was produced. Comparative Example 2 Ethylene-butene-1 used in Comparative Example 1
Instead of the copolymer, ethylene-butene-1 has a melting point of 121°C and a density of 0.952 g/ ^cm3 .
In addition to using copolymer (MI1.0g/10min),
The first to third stages of chlorination were carried out under the same conditions as in Comparative Example 1 to produce chlorinated polyethylene (hereinafter referred to as "CPE(D)") with a chlorine content of 39.5% by weight. Example 3 Ethylene-butene used in Example 1
1 copolymer was subjected to first-stage chlorination under the same conditions as in the first-stage chlorination of Example 1 until the chlorine content reached 21.3% by weight. Then, chlorination was carried out in the same manner as in the second stage chlorination of Example 1 to produce chlorinated polyethylene having a chlorine content of 31.9% by weight. Then,
Chlorinated polyethylene (hereinafter referred to as "CPE(E)") having a chlorine content of 36.3% by weight was produced by chlorination in the same temperature range as the third stage chlorination in Example 1. Comparative Examples 3 to 8 Example 1 Ethylene-butene-1 used in
The copolymer was chlorinated in the temperature range shown in Table 1 until the chlorine content was shown in Table 1, and each first stage chlorination was carried out. Next, each of the chlorinated polyethylenes obtained in this way was immediately chlorinated in the temperature range shown in Table 1 (second stage chlorination) to produce chlorinated polyethylene having the chlorine content shown in Table 1. was manufactured. Then, chlorination was carried out in the temperature range shown in Table 1 (third stage chlorination) to produce chlorinated polyethylene having the chlorine content shown in Table 1.

[Table] Note that in the third stage chlorination of Comparative Example 3, agglomeration occurred, and in the third stage chlorination of Comparative Example 4, the chlorination was non-uniform. In addition, agglomeration occurred in the second stage chlorination of Comparative Example 5, and Comparative Example 6
In the first stage chlorination of and 7, the chlorination was non-uniform and agglomeration occurred in the second stage. Furthermore, in the second stage chlorination of Comparative Example 8, the chlorination was non-uniform. In addition, heat resistance and processability were poor. The physical properties of each of the chlorinated polyethylenes obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were measured. The results are shown in Table 2.

【table】 [Brief explanation of drawings]

FIG. 1 is a wide-angle X-ray view. In FIG. 1, the dotted line b is an X-ray wide-angle diffraction graph of the chlorinated polyethylene [CPE(A)] obtained in Example 1.
Further, solid line a is an X-ray wide-angle diffraction graph of the ethylene-butene-1 copolymer used as a raw material in Example 1. In FIG. 1, the vertical axis is intensity, and the horizontal axis is 2θ (black angle).

Claims (1)

[Claims] 1. Density is 0.905 to 0.940 g/cm ³ and melting point is
106-130℃, melt index 0.01
〜100g/10min, and the number of carbon atoms is essentially 1 to 10.
The copolymer of ethylene and α-olefin in which the number of side chain alkyl groups is 3 to 35 per 1000 carbon atoms in the main chain has a chlorine content of 20 to 55% by weight, and the Mooney viscosity at a temperature of 100°C is with small rotor
In producing an aqueous suspension of chlorinated polyethylene, which has a peak of 10 to 60 points and a black angle 2θ of 8 to 15 degrees by X-ray wide-angle diffraction, including a peak due to amorphous crystals, (A ) In the first step, 20 to 60% of the total chlorination amount is chlorinated at a temperature at least 10°C lower than the melting point of the copolymer of ethylene and α-olefin used in the production of chlorinated polyethylene, and then (B) In the second step, chlorination is carried out at a temperature that is 5° C. or more higher than the chlorination temperature in the first step, but 5 to 15° C. lower than the melting point of the copolymer of ethylene and α-olefin, C) A method for producing chlorinated polyethylene, characterized in that in the third step, at least 10% of the total chlorination amount is chlorinated at a temperature 5 to 20° C. lower than the chlorination temperature in the second step.