JP2757210B2 - Chlorinated polyethylene and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel chlorinated polyethylene and a method for producing the same.

More specifically, the present invention relates to a novel chlorinated polyethylene having excellent heat-resistant mechanical strength and dynamic fatigue resistance, and a method for producing the same.

(Prior art) Chlorinated polyethylene obtained by chlorinating polyethylene is required to have excellent performance in weather resistance, ozone resistance, flame resistance, oil resistance, mechanical strength, and light color, such as rubber hose and rubber packing. , Rubber belt, rubber cable, rubber gasket, rubber roofing, etc.

However, conventionally known chlorinated polyethylene is inferior in heat-resistant mechanical strength, for example, tensile strength and tear strength at high temperatures of 100 ° C. or higher, and also has poor dynamic fatigue resistance, for example, bending crack resistance. I have. For this reason, in the molding of chlorinated polyethylene, a compounding agent for rubber of chlorinated polyethylene, for example, a reinforcing agent, a bulking agent, a softening agent, a physical aid, a vulcanizing agent, a vulcanization accelerator, using a rubber kneader A method has been adopted in which the kneaded mixture is molded and vulcanized at a high temperature of 100 ° C. or higher using an injection molding machine, and then the molded vulcanized material is removed from the mold of the injection molding machine with a considerable force. At that time, the molded vulcanizate is crushed, and the yield of the product is poor. In order to avoid destruction of the molded vulcanizate, the mold of the injection molding machine must be cooled and removed, and the mold must be heated to a high temperature again in performing the molding vulcanization. It is not very economical in terms of energy consumption and molding vulcanization efficiency. In addition, the molded vulcanized chlorinated polyethylene has inferior heat and mechanical strength, and thus its use in rubber hoses, rubber cables, rubber gaskets, and the like used at high temperatures is limited. Further, chlorinated polyethylene is used in fields requiring dynamic fatigue resistance such as rubber belts, but rubber belts used in automobiles and the like are required to have more excellent dynamic fatigue resistance from the viewpoint of safety.
Conventionally, chlorinated polyethylene does not have excellent dynamic fatigue resistance enough to be used for rubber belts of automobiles and the like, and at present, the range of use of chlorinated polyethylene in this field is limited.

Therefore, development of chlorinated polyethylene excellent in the above-mentioned problems of heat resistance mechanical strength and dynamic fatigue resistance is required.

(Problems to be Solved by the Invention) The present inventors have completed the present invention as a result of intensive studies in order to solve these problems of chlorinated polyethylene.

That is, to solve the above problems, a specific high-density polyethylene is chlorinated in an inert organic solvent under specific conditions, and a novel chlorinated polyethylene having a specific molecular weight distribution (MW / MN) and Mooney viscosity is used. I know that it will be achieved. This new chlorinated polyethylene improves energy consumption and molding vulcanization efficiency in the vulcanization of conventionally used chlorinated polyethylene, and is used in applications where heat-resistant mechanical strength is required. In addition to being able to be used, it has excellent dynamic fatigue resistance not found in conventional chlorinated polyethylene.

(Means for Solving the Invention) That is, the present invention has a chlorine content of 30 to 40% by weight, a molecular weight distribution (MW / MN) of 4.0 or less, and a Mooney viscosity at 100 ° C of 80 to 130, And a novel chlorinated polyethylene that is soluble in benzene, and has a melt index of 0.1 to 6.0 g /
High-density polyethylene having a molecular weight distribution (MW / MN) of 7.0 or less for 10 minutes is chlorinated in an inert organic solvent at 95 to 130 ° C. The present invention provides a novel method for producing a benzene-soluble chlorinated polyethylene having a distribution (MW / MN) of 4.0 or less, a Mooney viscosity at 100 ° C of 80 to 130, and being soluble in benzene.

 Hereinafter, the present invention will be described in detail.

The high-density polyethylene, which is a raw material of the chlorinated polyethylene of the present invention, refers to a Ziegler catalyst comprising a transition metal compound belonging to Groups IV to VIII of the periodic table and an organic metal compound belonging to I to III. A high-density polyethylene obtained by homopolymerizing ethylene under the condition of a temperature of 100 ° C. or less and a pressure of 20 kg / cm ² or less in an aromatic hydrocarbon and having a density measured by JIS K 6760 in the range of 0.941 to 0.965. Point. What is important in the present invention is that the polyethylene which is the raw material of the chlorinated polyethylene is a homopolymer of ethylene, and ethylene and butene-1, propylene and pentene-
The present invention cannot be achieved with a polyethylene copolymer comprising a copolymer with 1,4-methylpentene-1 or the like.

The high-density polyethylene used in the present invention is JIS K
The melt index measured by the 7210 (190 ° C., load 2.120 kg) is 0.1 to 6.0 g / 10 min, especially 0.5 to 3 g /
10 minutes is preferred. Melt index is 0.1g / 10
Chlorinated polyethylene made from high-density polyethylene of less than 1 minute has a Mooney viscosity at 100 ° C exceeding 130, which makes it difficult not only to knead with the rubber compounding agent, but also to mold the kneaded material. In vulcanization, the flow in the mold is inferior, and a satisfactory molded vulcanizate cannot be obtained. A chlorinated polyethylene using a high-density polyethylene exceeding 6.0 g / 10 minutes has a Mooney viscosity as low as less than 80, and the resulting vulcanizate has poor heat-resistant mechanical strength, which is not preferable.

As the high-density polyethylene used in the present invention, a high-density polyethylene having a molecular weight distribution (MW / MN) of 7.0 or less as measured by gel permeation chromatography is used. Preferably, it exhibits extremely excellent thermal mechanical strength and dynamic fatigue resistance at 6.0 or less. If the molecular weight distribution (MW / MN) exceeds 7.0, not only is the heat-resistant mechanical strength and dynamic fatigue resistance lowered, but also a molded product having poor fluidity in extrusion molding or the like cannot be obtained. Molecular weight distribution (MW / MN) of high density polyethylene referred to in the present invention
Is measured by the same gel permeation chromatography method as the molecular weight distribution (MW / MN) of chlorinated polyethylene, but the absolute value is different due to different measurement conditions as described later. The molecular weight distribution (MW / M
N) is defined by the following equation.

The inert organic solvent for dissolving and chlorinating high-density polyethylene according to the present invention is an organic solvent that is inert in a reaction for chlorinating high-density polyethylene, such as carbon tetrachloride, chloroform, dichloromethane, and the like. Ethane tetrachloride, ethane trichloride, tetrachloroethylene, trichloroethylene, monochlorobenzene, orthodichlorobenzene, benzene, etc., among them, considering the danger of fire and explosion during production and the danger to the human body , Carbon tetrachloride is preferred.

Chlorination of high-density polyethylene requires 5
High-density polyethylene dissolved in 〜20% by weight is chlorinated in a dissolving tank with chlorine gas, sulfurous acid gas or sulfuryl chloride. As the catalyst, an azo radical initiator, an organic peroxide, or ultraviolet light, for example, α, α-azobisisobutylnitrile, azobiscyclohexanecarbonitrile, benzoyl peroxide, acetyl peroxide, or the like is used. The chlorination temperature is performed in a temperature range of 95 to 130 ° C. If the temperature is lower than 95 ° C., the obtained chlorinated polyethylene has a structure having a portion insoluble in benzene, and the obtained vulcanized product is hard and loses rubber elasticity, and thus has poor dynamic fatigue resistance, which is not preferable. The structure, properties and physical properties of the chlorinated polyethylene obtained by chlorinating above 130 ° C are the same as those in the range of 95 to 130 ° C, but 130 ° C
Chlorination beyond this is disadvantageous in terms of energy consumption in production. And after chlorination, remove the acid components such as hydrogen chloride remaining in the inert organic solvent, then the obtained chlorinated polyethylene from the inert organic solvent, steam distillation method,
Separation and drying are performed by a drum drying method or an extrusion drying method to obtain a solid chlorinated polyethylene.

The chlorine content of the chlorinated polyethylene of the present invention is in the range of 30 to 40% by weight, preferably in the range of 33 to 38% by weight,
Shows excellent heat and mechanical strength and dynamic fatigue resistance. When the content is less than 30% by weight, the dynamic fatigue resistance is inferior, and when the chlorine content exceeds 40% by weight, the heat resistance mechanical strength and the cold resistance are inferior, which is not preferable.

Of particular interest in the chlorinated polyethylene for the purpose of the present invention is the molecular weight distribution (MW / Mw) of the chlorinated polyethylene measured by gel permeation chromatography.
N) is 4.0 or less. Preferably, at 3.5 or less, extremely excellent heat-resistant mechanical strength and dynamic fatigue resistance are exhibited. A chlorinated polyethylene having a molecular weight distribution (MW / MN) of more than 4.0 is inferior in heat-resistant mechanical strength and dynamic fatigue resistance, and at the same time, has poor fluidity in extrusion molding and the like, so that a satisfactory molded product cannot be obtained.

The chlorinated polyethylene of the present invention has a Mooney viscosity (ML1 + 4) at 100 ° C. measured by JIS K 6300.
It is in the range of 80-130. Mooney viscosity at 100 ° C is 80
If it is less than 130, the heat-resistant mechanical strength is inferior. If it exceeds 130, not only the kneading operation becomes difficult, but also the flow in the mold during molding vulcanization is inferior.

The chlorinated polyethylene soluble in benzene according to the present invention refers to a chlorinated polyethylene having no unextracted residue in benzene as measured with a Harris cage made of a 100-mesh stainless steel wire mesh according to JIS K 6388. Unextracted residues of benzene in the chlorinated polyethylene are not preferable because of poor heat-resistant mechanical strength and dynamic fatigue resistance. Generally, commercially available chlorinated polyethylene is obtained by suspending polyethylene powder in water and blowing chlorine gas into the chlorinated polyethylene, and benzene, which is considered to be polyethylene crystals, has an unextracted residue. The chlorinated polyethylene is, for example, toluene,
Organic solvents such as xylene, methyl ethyl ketone, ethyl acetate, propyl acetate, chloroform, carbon tetrachloride, and trichloroethane also have unextracted residues. The feature of the present invention is that high-density polyethylene is dissolved in an inert organic solvent and chlorinated, and the obtained chlorinated polyethylene is soluble in the organic solvent at normal temperature and normal pressure. No unextracted residue.

The chlorinated polyethylene of the present invention is formed and vulcanized by adding and kneading a vulcanizing agent, a vulcanization accelerator, a reinforcing agent, a filler, a plasticizer, a softening agent, an antioxidant, etc. in the same manner as conventional chlorinated polyethylene. Used by

(Examples) Hereinafter, the present invention will be described based on examples, but the present invention is not limited by these examples.

In addition, the measurement of the physical property value was performed based on the following measuring method.

<Measurement method> Melt index: JIS K 7210 Molecular weight distribution of high-density polyethylene: Gel permeation chromatography Z, measurement conditions are as follows Model: Waters GPC / 1500 Column: Tosoh GMH Two HT XLs are connected. One solvent: Ortho-dichlorobenzene Flow rate: 1.0 ml / min Temperature: 140 ° C Sample concentration: 0.1% by weight Detection method: RI method Calibration curve: manufactured by Tosoh Corporation According to standard polystyrene. In addition, it is based on the polystyrene SRM1482, 1483, and 1484 of the test solution BS.

Calculation of molecular weight distribution: The molecular weight obtained by standard polystyrene was taken as a Q factor of 17.7, and the molecular weight was obtained by multiplying the polyethylene molecular weight by 0.428.

Chlorine content: Combustion method Molecular weight distribution of chlorinated polyethylene: Gel permeation chromatography, measurement conditions as follows Model: HLC802A manufactured by Tosoh Co., Ltd. Column: GXL6 manufactured by Tosoh Co., Ltd. Solvent: tetrahydrofuran Flow rate: 1.2 ml / min Pressure: 44 to 45 Kg / cm ² Temperature: 38 ° C Sample concentration: 0.01% by weight Detection method: RI method Calibration curve: Using standard polystyrene manufactured by Tosoh Corporation .

Calculation of molecular weight distribution: Standard polystyrene itself was used.

Mooney viscosity: JIS K 6300 Vulcanized material properties: JIS K 6301 Unextracted benzene residue: JIS K 6388 Example-1 A 100 liter glass-lined autoclave has a melt index of 1.7 g / 10 min and a molecular weight distribution (MW / MN) takes 5 kg of high-density polyethylene with 5.5, then 65 kg of carbon tetrachloride and α, α-azobisisobutylnitrile
After charging 0.01 kg, the temperature was raised to 100 ° C. under pressure. At an autoclave gauge pressure of 2.5 kg / cm ² ,
Blowing was performed from the lower part of the autoclave at a rate of 0 liter / minute, and chlorination was performed until the chlorine content of the chlorinated polyethylene reached a target value of 36% by weight. Nitrogen gas was blown under normal pressure in order to remove acid components such as hydrochloric acid contained in a solution of chlorinated polyethylene in carbon tetrachloride. Next, carbon tetrachloride and chlorinated polyethylene were separated by a drum dryer having a surface temperature of 145 ° C. The resulting chlorinated polyethylene was a white solid. Table 1 shows the results of the analysis test of the solid.

The obtained chlorinated polyethylene was kneaded with the following components using an 8-inch roll manufactured by Toyo Seiki Seisaku-sho, Ltd., and subjected to vulcanization for 40 minutes using a compression vulcanizer having a mold temperature of 160 ° C. Was performed. The molded vulcanizate was tested for physical properties.
Table 1 shows the measurement results.

Example 2 A chlorinated polyethylene was obtained in the same manner as in Example 1 except that the temperature was increased from 100 ° C. under pressure to 110 ° C. Table 1 shows the results of the analytical tests performed on the obtained chlorinated polyethylene in the same manner as in Example 1 and the results of the physical property tests of the molded vulcanizates.

Example-3 In Example-1, the melt index was 1.7 g / 10.
Example except that the high-density polyethylene having a molecular weight distribution (MW / MN) of 5.5 was changed to a high-density polyethylene having a melt index of 1.1 g / 10 min and a molecular weight distribution (MW / MN) of 5.7. In the same manner as in Example 1, chlorinated polyethylene was obtained. Table 1 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Example-4 In Example-1, the melt index was 1.7 g / 10.
Example, except that the high-density polyethylene having a molecular weight distribution (MW / MN) of 5.5 was changed to a high-density polyethylene having a melt index of 1.8 g / 10 min and a molecular weight distribution (MW / MN) of 5.3. In the same manner as in Example 1, chlorinated polyethylene was obtained. Table 1 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Example 5 A chlorinated polyethylene was prepared in the same manner as in Example 1 except that the target value of the chlorine content of the chlorinated polyethylene was changed to 36% by weight, and the target value of the chlorine content of the chlorinated polyethylene was changed to 38% by weight. I got Table 1 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Example 6 A chlorinated polyethylene was prepared in the same manner as in Example 1 except that the target value of the chlorine content of the chlorinated polyethylene, 36% by weight, was changed to 34% by weight of the target value of the chlorine content of the chlorinated polyethylene. I got Table 1 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Example -7 In Example 1, the melt index was 1.7 g / 10.
And the target value of chlorine content of high-density polyethylene and chlorinated polyethylene having a molecular weight distribution (MW / MN) of 5.5.
Example 1 except that the melt index was changed to the target value of 38% by weight for the melt content of 4.0 g / 10 min and the molecular weight distribution (MW / MN) of 5.3 for the high-density polyethylene and the chlorinated polyethylene having a 5.3 molecular weight distribution. In the same manner, chlorinated polyethylene was obtained. Table 1 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example-1 A chlorinated polyethylene was obtained in the same manner as in Example 1 except that the temperature was increased from 110 ° C under pressure to 93 ° C. Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example-2 In Example 1, the melt index was 1.7 g / 10.
Example, except that the high-density polyethylene having a molecular weight distribution (MW / MN) of 5.5 was changed to a high-density polyethylene having a melt index of 1.0 g / 10 minutes and a molecular weight distribution (MW / MN) of 7.7. In the same manner as in Example 1, chlorinated polyethylene was obtained. Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example-3 In Example 1, the melt index was 1.7 g / 10.
Example, except that the high-density polyethylene having a molecular weight distribution (MW / MN) of 5.5 was changed to a high-density polyethylene having a melt index of 0.9 g / 10 min and a molecular weight distribution (MW / MN) of 8.6. In the same manner as in Example 1, chlorinated polyethylene was obtained. Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example 4 A chlorinated polyethylene was prepared in the same manner as in Example 1 except that the target value of the chlorine content of the chlorinated polyethylene was changed to 36% by weight, and the target value of the chlorine content of the chlorinated polyethylene was changed to 43% by weight. I got Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example-5 A chlorinated polyethylene was prepared in the same manner as in Example 1, except that the target value of the chlorine content of the chlorinated polyethylene was changed to 36% by weight, and the target value of the chlorine content of the chlorinated polyethylene was changed to 28% by weight. I got Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example-6 In Example 1, the melt index was 1.7 g / 10.
Example except that the high-density polyethylene having a molecular weight distribution (MW / MN) of 5.5 was changed to a high-density polyethylene having a melt index of 14.5 g / 10 min and a molecular weight distribution (MW / MN) of 4.8. In the same manner as in Example 1, chlorinated polyethylene was obtained. Table 2 shows the results of the analysis test and the physical property test of the molded vulcanizate of the obtained chlorinated polyethylene in the same manner as in Example 1.

Comparative Example -7 An analysis test and a physical property test of a molded vulcanized product of a commercially available chlorinated polyethylene, Daisorac H-135, manufactured by Daiso Corporation were performed in the same manner as in Example 1. Table 2 shows the results.

Comparative Example-8 An analysis test and a physical property test of a molded vulcanizate of a commercially available chlorinated polyethylene, Daisorac MR-104, manufactured by Daiso Corporation were performed in the same manner as in Example-1. Table 2 shows the results.

As described above, the examples shown in Table 1 are compared with the comparative examples shown in Table 2, and it is clear that the examples are novel chlorinated polyethylenes having excellent heat-resistant mechanical strength and dynamic fatigue resistance.

(Effect of the Invention) From the above description, in the chlorinated polyethylene of the present invention and the method for producing the same, the melt index is 0.1 to 6.0 g / 10.
And the chlorine content obtained by chlorinating high-density polyethylene having a molecular weight distribution (MW / MN) of 7.0 or less in an inert organic solvent at 95 to 130 ° C. is 30 to 40% by weight, and the molecular weight distribution is (MW / MN) is 4.0 or less, the Mooney viscosity at 100 ° C. is 80 to 130, and the chlorinated polyethylene soluble in benzene is a novel chlorinated polyethylene.

It can also be seen that the new chlorinated polyethylene has excellent heat and mechanical strength and dynamic fatigue resistance.

Claims (2)

(57) [Claims] (1) a chlorine content of 30 to 40% by weight and a molecular weight distribution (MW
/ MN) is 4.0 or less and the Mooney viscosity at 100 ° C is 8
Chlorinated polyethylene which is 0 to 130 and soluble in benzene. 2. A high-density polyethylene having a melt index of 0.1 to 6.0 g / 10 minutes and a molecular weight distribution (MW / MN) of 7.0 or less is chlorinated in an inert organic solvent at 95 to 130 ° C. Production of chlorinated polyethylene with a chlorine content of 30-40% by weight, a molecular weight distribution (MW / MN) of 4.0 or less, a Mooney viscosity at 100 ° C of 80-130, and soluble in benzene Law.