JPH0629298B2 - Vinyl chloride copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vinyl chloride copolymer having excellent antistatic properties.

(Prior Art) Vinyl chloride-based copolymers are widely used as various molded products, sheets and films because they are inexpensive, have good moldability, and have excellent properties. However, molded products of vinyl chloride-based copolymers are easily charged with electricity, which causes various obstacles. In order to prevent such electrification, it has been attempted to impart conductivity to the vinyl chloride copolymer.

As the vinyl chloride-based copolymer having conductivity, there are a copolymer prepared by blending a surfactant, carbon black, metal powder, conductive fibers and the like, and a copolymer coated with a surfactant on the surface. However, since the surfactant easily bleeds and falls off the surface of the molded body, the antistatic effect is not maintained. Although the antistatic effect is maintained by adding carbon black, metal powder, conductive fibers, etc., it is necessary to add a large amount of these conductive substances in order to obtain the desired conductivity. Therefore, it becomes expensive. A vinyl chloride-based copolymer having a noble metal or metal oxide adhered to its surface by vapor deposition, sputtering, etc., has an excellent antistatic effect, but is expensive and has low productivity.

In order to solve these drawbacks, carbon black,
There is a vinyl chloride-based copolymer in which a conductive coating material in which a conductive material such as metal powder is dispersed is used and which is coated on the surface. Although this copolymer is inexpensive and exhibits an excellent antistatic effect, the conductive material is different from the resin, and therefore bleeding and dropping may occur.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a vinyl chloride-based copolymer which is inexpensive and has excellent antistatic properties. Especially.

(Means for Solving Problems) In the present invention, by incorporating a monomer unit having conductivity into the skeleton of a vinyl chloride-based copolymer, bleeding or dropping does not occur and the antistatic property can be significantly improved. It was completed based on the knowledge of the inventor.

The vinyl chloride-based copolymer of the present invention comprises (1) a vinyl chloride unit, (2) a substituted ammonio group-containing (meth) acrylic acid derivative unit represented by the formula (I), and (3) (II) a formula. (Meth) acrylic acid polyalkylene oxide ester unit, which achieves the above object.

Here, R ₁ and R ₇ are the same or different and each is a hydrogen atom or a methyl group, R ₂ is —O— or —NH—, and R ₃ is an alkylene group having 2 to 6 carbon atoms or a hydroxyl group-containing alkylene group. , R ₄ , R ₅ and R ₆ are the same or different and have 1 carbon atom
Is an alkyl group of 6 to 6, R ₈ is a polyoxyalkylene group having a degree of polymerization of 2 to 23, X is halogen, and Y is a hydrogen atom or an aliphatic or aromatic hydrocarbon group having 1 to 6 carbon atoms.

The vinyl chloride unit is contained in the range of 50 to 96% by weight, preferably 74 to 93% by weight. When it is less than 50% by weight, the properties as a vinyl chloride copolymer are lost. If it exceeds 96% by weight, the desired antistatic property cannot be obtained. The substituted ammonio group-containing (meth) acrylic acid derivative unit represented by the formula (I) is contained in the range of 1 to 10% by weight, preferably 2 to 6% by weight. If it is less than 1% by weight, the desired antistatic property cannot be obtained. When it exceeds 10% by weight, properties such as thermal stability as a vinyl chloride copolymer are lost.
The (meth) acrylic acid polyalkylene oxide unit represented by the formula (II) is 3 to 40% by weight, preferably 5 to 20% by weight.
It is contained in the range of. If it is less than 3% by weight, the desired antistatic property cannot be obtained. When it exceeds 40% by weight, properties such as thermal stability as a vinyl chloride copolymer are lost.

Examples of the substituted ammonio group-containing (meth) acrylic acid derivative represented by the formula (I) include 2-hydroxy-3-acryloyloxypropyltrimethylammonium chloride, 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride and acryloyloxy. There are ethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride, and 3-methacrylamidopropyltrimethylammonium chloride.

Examples of the (meth) acrylic acid polyalkylene oxide ester represented by the formula (II) include polypropylene glycol methacrylate, polyethylene glycol methacrylate, polyethylene glycol polypropylene glycol methacrylate, polyethylene glycol polybutylene glycol methacrylate, methoxy polyethylene glycol methacrylate, and methoxy polyethylene glycol. There are acrylate, phenoxy polyethylene glycol acrylate, and butoxydiethylene glycol acrylate.

The vinyl chloride-based copolymer of the present invention may contain other monomer units copolymerizable with vinyl chloride within a range that does not impair the antistatic property. Examples of the monomer include olefins such as ethylene and propylene, vinyl acetates such as vinyl acetate and vinyl propionate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth). There are non-functional (meth) acrylates such as acrylate and lauryl (meth) acrylate, and vinylidene chloride. Such monomer units are the Tg of the copolymer,
It is included to improve viscosity and solubility.

As a method for synthesizing the copolymer, any known polymerization method can be used, and examples thereof include an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a precipitation polymerization method. As a medium of the precipitation polymerization method,
Lower alcohols, especially methanol, are preferred due to their low cost. In the precipitation polymerization method, the copolymer is obtained as a fine powder, which facilitates molding. Polymerization temperature is 35-70 ℃
The range is.

The vinyl chloride-based copolymer of the present invention has good solubility in organic solvents. Examples of the soluble solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, chlorinated solvents such as ethylene dichloride and chloromethane, tetrahydrofuran, dimethylformamide, There are polar solvents such as dimethylsulfoxide.

(Examples) The present invention will be described below with reference to Examples.

Example 1 An autoclave with a stainless steel stirrer having an internal volume of 20 was charged with 6 kg of methanol and 50 g of α-cumylperoxy neodecanoate (Parkmill ND, manufactured by NOF CORPORATION) as a polymerization initiator. After exhausting the autoclave for 5 minutes with an aspirator, vinyl chloride monomer 3.1k
g was added.

Evacuate the 3 stainless steel containers (additional containers) that can be hung, and add tetraethylene glycol monomethacrylate 20
After 0 g, 50 g of methacryloyloxyethyltrimethylammonium chloride and 1 kg of methanol were charged by suction, 1.65 kg of vinyl chloride monomer was injected under pressure. This addition container was shaken, the contents were mixed and dissolved in methanol, then hung on a spring balance, the flexible tube was attached to the valve at the bottom of the container, and it was connected to the addition nozzle of the polymerization reactor. .

The stirrer of the autoclave was rotated at 250 rpm and warm water was passed through the jacket to raise the temperature to 43 ° C. The polymerization reaction started at 43 ° C. At this point, the valve of the addition container was opened, and 47 g of a methanol solution of the monomer was added. Then, according to the progress of the polymerization reaction, 63 g 14 times every 5 minutes,
The addition was repeated by dividing 59 g 8 times and 53 g 22 times. Five minutes after the addition was completed, the autoclave was cooled to 25 ° C. to stop the polymerization reaction. The internal pressure of the autoclave was 2.5 kg / cm ² G at the start of the reaction and 2.0 kg / cm ² G at the end of the reaction.

After the polymerization reaction was completed, unreacted vinyl chloride monomer was released into the atmosphere. Further, nitrogen gas was passed through the autoclave to completely remove the vinyl chloride monomer, and then the methanol slurry of the copolymer was taken out and filtered. The filtrate was vacuum dried at 50 ° C. for 24 hours to obtain 1.53 kg of a white powdery granular copolymer. The copolymer contains 87.9% by weight of vinyl chloride units, 9.7% by weight of tetraethylene glycol monomethacrylate units, and 2. units of methacryloyloxyethyl trimethylammonium chloride units.
It was contained at 4% by weight. The average degree of polymerization of the copolymer was 450.

The copolymer was dissolved in a methyl isobutyl ketone / toluene mixed solvent (weight ratio 1/1) to obtain a 10 wt% concentration solution. Pour 150 g of this solution into a glass plate (32 cm x 32 cm),
After drying at room temperature for about 24 hours, it was further dried under reduced pressure at 50 ° C. for 48 hours to prepare a casting film having a thickness of about 100 μm. The surface resistivity, volume resistivity, and thermal stability of this film were measured as follows.

Surface resistivity and volume resistivity; after casting film is left at 20 ° C, 60% RH for 3-4 hours, HIGH MEG
Using OHM METER TR-8601 (manufactured by Takeda Riken), JIS C
The resistance value was measured by -2318.

Thermal stability: The casting film was placed in a gear oven at 150 ° C, and the thermal stability was evaluated by measuring the time until blackening.

In addition, the solubility of the copolymer in organic solvents depends on the copolymer's methyl isobutyl ketone / toluene mixed solvent (weight ratio).
When it was dissolved in 1/1) at 20% by weight, it was completely dissolved to form a transparent solution, and if this solution was used to make a uniform and transparent casting film, the solubility was considered good. If the above conditions were not satisfied, the solubility was evaluated as poor.

The results of these measurements are shown in the table below.

Example 2 Same as Example 1 except that the vinyl chloride unit in the copolymer was 86.8% by weight, the tetraethylene glycol monomethacrylate unit was 9.5% by weight, and the methacryloyloxyethyltrimethylammonium chloride unit was 3.7% by weight. And a copolymer was synthesized. The average degree of polymerization of the copolymer was 430. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Example 3 Methoxytetraethylene glycol monomethacrylate was used in place of tetraethylene glycol monomethacrylate, 88.8% by weight of vinyl chloride units, 8.9% by weight of methoxytetraethylene glycol monomethacrylate units, and methacryloyloxyethyltrimethyl in the copolymer. A copolymer was synthesized in the same manner as in Example 1 except that the ammonium chloride unit was 2.3% by weight. The average degree of polymerization of the copolymer was 450. The solubility of the copolymer was measured by the same method as in Example 1.
Using this copolymer, a casting film was prepared in the same manner as in Example 1, and its surface resistivity,
Volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Example 4 Using diethylene glycol monomethacrylate instead of tetraethylene glycol monomethacrylate, 87.4 wt% vinyl chloride units, 10.1 wt% diethylene glycol monomethacrylate units and 2.5 wt% methacryloyloxyethyltrimethylammonium chloride units in the copolymer. A copolymer was synthesized in the same manner as in Example 1 except that the percentage was changed. The average degree of polymerization of the copolymer was 440. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Example 5 Substituting octaethylene glycol monomethacrylate for tetraethylene glycol monomethacrylate,
The copolymer was prepared in the same manner as in Example 1 except that the vinyl chloride unit in the copolymer was 87.2% by weight, the octaethylene glycol monomethacrylate unit was 10.5% by weight, and the methacryloyloxyethyltrimethylammonium chloride unit was 2.3% by weight. A polymer was synthesized. The average degree of polymerization of the copolymer was 410. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Example 6 Using trimethyl-3-methacrylamido-propylammonium chloride instead of methacryloyloxyethyltrimethylammonium chloride, 87.3% by weight of vinyl chloride units, 10.2% by weight of tetraethylene glycol monomethacrylate units in the copolymer, and A copolymer was synthesized in the same manner as in Example 1 except that trimethyl-3-methacrylamido-propylammonium chloride was 2.5% by weight. The average degree of polymerization of the copolymer was 420. The solubility of the copolymer is shown in Example 1.
It measured by the method similar to. Using this copolymer,
A casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability of the casting film were measured. The results of these measurements are shown in the table below.

Comparative Example 1 Without using tetraethylene glycol monomethacrylate, vinyl chloride units in the copolymer were 81.9% by weight,
Example 1 except that the methacryloyloxyethyltrimethylammonium chloride unit was 18.1% by weight.
A copolymer was synthesized in the same manner as in. The average degree of polymerization of the copolymer was 180. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Comparative Example 2 88.9% by weight of vinyl chloride units in the copolymer was used without using tetraethylene glycol monomethacrylate.
Example 1 except that the methacryloyloxyethyl trimethyl ammonium chloride unit was 11.1% by weight.
A copolymer was synthesized in the same manner as in. The average degree of polymerization of the copolymer was 250. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Comparative Example 3 Using 2-hydroxypropyl acrylate instead of tetraethylene glycol monomethacrylate, vinyl chloride units in the copolymer were 79.5% by weight, 2-hydroxypropyl acrylate units were 18.1% by weight, and methacryloyloxyethyltrimethylammonium chloride. A copolymer was synthesized in the same manner as in Example 1 except that the content was 2.4% by weight. The average degree of polymerization of the copolymer is 350
Met. The solubility of the copolymer was measured by the same method as in Example 1. Using this copolymer, a casting film was prepared in the same manner as in Example 1, and the surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

Comparative Example 4 A copolymer was prepared in the same manner as in Example 1 except that methacryloyloxyethyltrimethylammonium chloride was not used and the vinyl chloride unit and the tetraethylene glycol monomethacrylate unit in the copolymer were 90.0% by weight and 10.0% by weight, respectively. A polymer was synthesized. The average degree of polymerization of the copolymer was 400. The solubility of the copolymer was measured by the same method as in Example 1. Example 1 using this copolymer
Make a casting film by the same method as
The surface resistivity, volume resistivity and thermal stability were measured. The results of these measurements are shown in the table below.

As is clear from Examples and Comparative Examples, the vinyl chloride-based copolymer of the present invention has a low volume resistivity value and a surface resistivity value and is excellent in conductivity. Therefore, the antistatic property is high. It also has good thermal stability and solubility in organic solvents. The vinyl chloride copolymer having no (meth) acrylic acid polyalkylene oxide ester unit represented by the formula (II) lacks solubility and thermal stability. A vinyl chloride-based copolymer having no substituted ammonio group-containing (meth) acrylic acid derivative unit represented by the formula (I) has a high volume resistivity value and a high surface resistivity value and lacks conductivity. Therefore, the antistatic property is not sufficiently achieved. A copolymer containing a 2-hydroxypropyl acrylate unit in place of the (meth) acrylic acid polyalkylene oxide ester unit represented by the formula (II) also lacks conductivity and has a small antistatic effect.

(Effect of the Invention) The vinyl chloride-based copolymer of the present invention is inexpensive and has excellent antistatic properties. The antistatic property can be maintained for a long time. Moreover, it has good thermal stability, solubility, and moldability. Therefore, the copolymer of the present invention can be effectively used for a conductive sheet, a conductive coating material, a conductive treatment material, an antistatic material and the like.

Claims (6)

[Claims] 1. A vinyl chloride unit (1), a substituted ammonio group-containing (meth) represented by the formula (2) (I).
A vinyl chloride copolymer having an acrylic acid derivative unit and a (meth) acrylic acid polyalkylene oxide ester unit represented by the formula (3) (II). Here, R ₁ and R ₇ are the same or different and each is a hydrogen atom or a methyl group, R ₂ is —O— or —NH—, and R ₃ is an alkylene group having 2 to 6 carbon atoms or a hydroxyl group-containing alkylene group. , R ₄ , R ₅ and R ₆ are the same or different and have 1 carbon atom
Is an alkyl group of 6 to 6, R ₈ is a polyoxyalkylene group having a degree of polymerization of 2 to 23, X is a halogen, and Y is a hydrogen atom or an aliphatic or aromatic hydrocarbon group having 1 to 6 carbon atoms. 2. The vinyl chloride-based copolymer according to claim 1, wherein the vinyl chloride unit is contained in the range of 50 to 96% by weight. 3. The vinyl chloride copolymer according to claim 1, wherein the substituted ammonio group-containing (meth) acrylic acid derivative unit is contained in the range of 1 to 10% by weight. 4. The vinyl chloride copolymer according to claim 1, wherein the poly (meth) acrylic acid polyalkylene oxide ester unit is contained in the range of 3 to 40% by weight. 5. The substituted ammonio group-containing (meth) acrylic acid derivative is 2-hydroxy-3-acryloyloxypropyltrimethylammonium chloride, 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride. The vinyl chloride-based copolymer according to claim 1, which is at least one of :, methacryloyloxyethyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride and 3-methacrylamidopropyltrimethylammonium chloride. 6. The (meth) acrylic acid polyalkylene oxide ester is polypropylene glycol methacrylate, polyethylene glycol methacrylate, polyethylene glycol polypropylene glycol methacrylate, polyethylene glycol polybutylene glycol methacrylate, methoxy polyethylene glycol methacrylate, methoxy polyethylene glycol acrylate, phenoxy polyethylene. The vinyl chloride copolymer according to claim 1, which is at least one of glycol acrylate and butoxydiethylene glycol acrylate.