JPH09255939A - Heat-resistant antistatic agent and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an antistatic agent having improved heat resistance by adding a salt of an alkali metal with a metal fluoride to a quat. ammonium-salt- group-containing polymer quaternized with a quaternizing agent to effect a counter ion exchange reaction. SOLUTION: A salt of an alkali metal with a monovalent metal fluoride (e.g.BF4 <-> , PF6 <-> ,AsF6 <-> or SbF6 <1> ) is added to a polymer having ammonium salt groups quaternized with a quaternizing agent to effect an counter ion exchange reaction to obtain a polymer having quat. ammonium salt groups the counter ions of which are BF4 <-> , PF6 <-> , AsF6 <-> or SbF6 <-> . The obtained polymer can be used as a heat-resistant antistatic agent for thermoplastic resins injection-molded at high temperatures.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat resistant antistatic agent and a method for producing the same. The heat-resistant antistatic agent of the present invention has good heat resistance and can be used as a permanent antistatic agent for various thermoplastic resins.

[0002]

2. Description of the Related Art Conventionally, polymers having a quaternary ammonium salt group have been known as effective permanent antistatic agents for thermoplastic resins. For example, JP-B-49-16033.
As described in JP-A-63-54466 and JP-A-63-54466, produced by reacting a corresponding amino group with a quaternizing agent such as an alkyl halide, a sulfonic acid ester, an alkyl phosphoric acid or an alkyl sulfuric acid. Has been done. Among these, quaternizing agents of sulfonic acid esters or alkylsulfates have been considered to be particularly preferable from the viewpoint of heat resistance.

[0003]

However, even those polymers having a quaternary ammonium salt group have practically insufficient heat resistance, and when used as an antistatic agent for thermoplastic resins having a high molding temperature, they are Generation of gas and coloration due to thermal decomposition of primary ammonium bases are problems.

[0004]

Means for Solving the Problems The present inventors have made extensive studies in view of the above-mentioned current situation. As a result, it is known that quaternary ammonium salts are gradually decomposed by heating counterions and water as a nucleophile to attack substituents when heated, and further, for example, quaternary ammonium salts such as benzyl ammonium salts. It has been reported that the properties of cationic polymerization as a thermal latent polymerization initiator are strongly dependent on the nucleophilicity of the counterion (for example, Journal of Polymer Science, Part C: Polymer Letter Edition (Jo
urnalof Polymer Science, Part C: Polymer Letter Ed
ittion), 26, 453, 1988),
Converting the counterion of a quaternary ammonium salt into a stable, less nucleophilic ion suggesting that the nucleophilicity of the counterion significantly affects the thermal decomposition behavior of the quaternary ammonium salt. It was considered that the heat resistance of the polymer having a quaternary ammonium salt group can be improved by the above.

Since it has been already known that quaternary ammonium salts such as benzylammonium chloride can easily convert counterions with metal fluoride alkali metal salts, quaternary ammonium salts can be utilized by utilizing this counterion conversion. When the counterion of ammonium base is converted to a stable monovalent metal fluoride ion with low nucleophilicity, a polymer having a stable nucleophilic quaternary ammonium base with low nucleophilicity is obtained. According to the polymer having an ammonium base, the heat resistance is improved while maintaining the antistatic property permanently, and the so-called silver is generated due to coloring or gas generation of the thermoplastic resin composition due to thermal decomposition during molding. It has been found that can suppress. The present invention has been completed based on this new finding.

That is, the present invention is a heat-resistant antistatic agent containing a polymer having a quaternary ammonium salt group, wherein the counter ion of the quaternary ammonium salt group is a monovalent metal fluoride ion. A heat-resistant antistatic agent, and a polymer having a quaternary ammonium salt group quaternized with a quaternizing agent, a metal fluoride alkali metal salt is added to carry out counterion exchange. The present invention relates to a method for producing an antistatic agent.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer of the present invention having a quaternary ammonium salt group whose counter ion is converted by a metal fluoride alkali metal salt is a quaternary ammonium salt quaternized with a quaternizing agent. There is no particular limitation as long as it is a polymer into which a base has been introduced. In general, such a polymer having a quaternary ammonium salt group is obtained by quaternizing a polymer having an amino group corresponding to the quaternary ammonium salt group with a quaternizing agent or quaternizing a vinyl monomer having a corresponding amino group. A vinyl monomer having a quaternary ammonium salt group quaternized with an agent can be produced by homopolymerization or copolymerization with another vinyl monomer.

The amino group corresponding to the quaternary ammonium salt group is, for example,

General formula (1):-(CH ₂ ) _n -NR ¹ R ²

(In the formula, n represents an integer of 2 to 4, R ¹ ,
R ^2's each independently represent an alkyl group having 1 to 9 carbon atoms or a hydroxyalkyl group). As a specific example of such a vinyl monomer having an amino group, dimethylaminoethyl (meth) acrylate {here, (meth) acrylate means acrylate or methacrylate. Hereinafter, (meta) has the same meaning. }, Diethylaminoethyl (meth) acrylate,
Dimethylaminopropyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, dihydroxyethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethyl Aminopropyl (meta)
Acrylamide etc. can be mentioned.

Further, the quaternary ammonium salt group introduced into the monomer or polymer is obtained by quaternizing the amino group with a quaternizing agent.

[0012] Formula _{(2) :-( CH 2) n} -N + R 1 R 2 R 3 Y -

(Where n, R ¹ and R ² are the same as above, R
³ represents a benzyl group which may have an alkyl group having 1 to 9 carbon atoms or an alkyl group having 1 to 9 carbon atoms, and Y represents RS
It is represented by O ₃ , ROSO ₃ or a halogen atom (wherein R represents an alkyl group having 1 to 20 carbon atoms or a phenyl group which may have an alkyl group having 1 to 20 carbon atoms).

For the quaternization of the amino group with a quaternizing agent, a known method can be adopted. Usually, it can be carried out by adding a quaternizing agent in an equimolar amount or more to the amino group to the vinyl monomer or polymer solution.
The temperature during the quaternization reaction is about 90 ° C. or lower, and particularly when quaternizing a vinyl monomer is preferably about 30 ° C. or lower, and the reaction time is about 1 to 4 hours. The solvent for the quaternization is not particularly limited as long as it can dissolve both the monomer or polymer having the corresponding amino group and the monomer or polymer having the quaternized quaternary ammonium salt group. For example, low boiling point polar solvents such as acetone and tetrahydrofuran, glycol ethers such as ethylene glycol monoethyl ether and diethylene glycol monoethyl ether, N, N
Examples thereof include amide compounds such as dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone, and polar solvents such as dimethylsulfoxide. These solvents can be used alone or in combination. In addition, if necessary, a solvent insoluble in the monomer or polymer having a quaternary ammonium salt group may be mixed and used within a range that does not impair the solubility of the solvent having good solubility.

Specific examples of the quaternizing agent include alkylsulfates such as dimethylsulfate, diethylsulfate and dipropylsulfate,
Examples thereof include sulfonic acid esters such as methyl p-toluenesulfonate and methyl benzenesulfonate, and alkyl halides such as alkyl chloride, alkyl bromide and benzyl chloride.

Further, the vinyl monomer having an amino group or another vinyl monomer copolymerized with the vinyl monomer having a quaternary ammonium salt group can be appropriately selected and used to improve various physical properties, and is a copolymer. If there are no restrictions. For example, aromatic vinyl compounds such as styrene, α-methylstyrene, bromostyrene, vinyl cyanide compounds such as (meth) acrylonitrile, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, 2 -(Meth) such as hydroxyethyl (meth) acrylate
Acrylic esters, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide and other (meth) acrylamides and vinyl acetate, vinyl propionate and other vinyls. Examples thereof include esters. These vinyl monomers can be used alone or in combination.

The copolymer composition of the polymer having a quaternary ammonium salt group is not particularly limited and can be arbitrarily set in consideration of the performance in the final use. It is preferable that the ratio of the vinyl monomer having an amino group is 5 mol% or more of all vinyl monomers for use in the permanent antistatic agent.

The method of homopolymerizing the vinyl monomer having a quaternary ammonium salt group quaternized with the amino group or the quaternizing agent or copolymerizing the vinyl monomer with another vinyl monomer is not particularly limited, and a commonly known method is used. The method of can be used. That is, solution polymerization or the like can be carried out at a reaction temperature of about 30 to 100 ° C in the presence of a radical polymerization initiator and a chain transfer agent. In addition, the concentration of the whole monomer at the time of polymerization or copolymerization is usually about 10 to 90% by weight,
It is preferably carried out in the range of 20 to 80% by weight. Also,
The weight average molecular weight of the obtained polymer is 1000 to 500.
It is preferably 000. When the weight average molecular weight is too low, not only permanent antistatic property cannot be obtained, but also heat resistance decreases, which is not preferable.

The method of exchanging the counter ion of the polymer having a quaternary ammonium salt group quaternized with a quaternizing agent for a monovalent metal fluoride ion is not particularly limited, and a known method can be adopted. it can. Usually, a solution of the polymer having a quaternary ammonium salt group (the counter ion is usually RSO ₄ ⁻ , RSO ₃ ^−, or a halogen ion) obtained as described above in water or a water-soluble solvent is added with a metal fluoride. It can be carried out by dropping and mixing an aqueous solution of an alkali metal salt of a halide.

Upon counterion exchange, an aqueous solution of a polymer having a quaternary ammonium salt group is prepared by reprecipitating the polymer having a quaternary ammonium salt group or separating the polymer as a solid by removing the solvent under heating or reduced pressure. It can be carried out by a method of dissolving in water or a method of adding water after quaternization in a water-soluble solvent. Here, the concentration of the polymer solution is 50% by weight or less, preferably 20% by weight or less. If the concentration is too high, the solution viscosity becomes high and the mixing operation becomes difficult, which is not preferable.
In addition, in order to remove the solvent and obtain a polymer having a quaternary ammonium salt group, it is desirable that the temperature at the time of removing the solvent be as low as possible. Therefore, polyalkylene oxides such as polyethylene glycol, polypropylene glycol, and polyethylene glycol-polypropylene glycol block copolymer can be added for the purpose of reducing the viscosity at the time of melting. The amount of such an additive to be used can be arbitrarily set in consideration of the viscosity and fluidity at the time of melting, but is usually 50% by weight or less, preferably about 10 to 50% by weight based on the polymer.

On the other hand, the concentration of the aqueous solution of the metal fluoride alkali metal salt mixed with the aqueous solution of the polymer having a quaternary ammonium salt group is usually adjusted to 50% by weight or less, preferably 20% by weight or less. The metal fluorinated alkali metal salts include SbF ⁶⁻ , AsF ⁶⁻ , PF ⁶⁻ , BF ^4−.
Can be used. Examples of alkali metals include lithium, potassium and sodium. The amount of the metal fluoride alkali metal salt used for counter ion exchange is 50 equivalent% with respect to the counter ion (RSO ₄ ⁻ , RSO ₃ ⁻ or halogen ion) in the polymer having the quaternary ammonium salt group. Or more, preferably 100 equivalent% or more. When the amount used is less than 50 equivalent%, the counterion conversion rate is less than 50%, and heat resistance is not improved, which is not preferable. The upper limit of the amount used is not particularly limited, but when an excessive amount is used, it may be performed within a practical range.

The counterion exchange can be carried out in an aqueous solution as described above, and in addition to the polymer having a quaternary ammonium salt group quaternized with the quaternizing agent and the counterion of the present invention, a metal fluoride ion. In consideration of the solubility of the polymer having a quaternary ammonium salt group converted into, it can be carried out in a water-soluble solvent such as methanol, acetone, dimethylsulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide. The concentration of the polymer solution at that time is 50% by weight or less, preferably 20% by weight or less. If the concentration is too high, the solution viscosity becomes high and the mixing operation becomes difficult, which is not preferable.

The temperature during the counterion exchange reaction is not particularly limited as long as it is not higher than the boiling point of the solvent, but is usually room temperature. The reaction time is about 1 to 4 hours.

The polymer having a quaternary ammonium salt group whose counter ion is a monovalent metal fluoride ion, which has undergone counter ion exchange in this way, can be separated from water as a water-insoluble substance after the reaction. . When the counterion exchange is carried out under a uniform condition using a suitable water-soluble solvent, the reaction solution is put into a precipitation solvent such as a large excess of water, or the solvent is removed under reduced pressure by heating. By the method or the like, a polymer having a quaternary ammonium salt group whose counter ion is a monovalent metal fluoride ion can be obtained as a solid.

The polymer having a quaternary ammonium salt group whose counter ion is a monovalent metal fluoride ion obtained by the present invention can be used as a permanent antistatic agent for various thermoplastic resins. As the thermoplastic resin, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, polymethylmethacrylate, polystyrene,
Styrene-acrylonitrile copolymer, styrene- (meth) acrylic acid ester copolymer, ABS resin, polyoxymethylene, polyacetal, polyphenylene ether, PPS resin, polycaprolactam, polycaprolactone, nylon 66, polysulfone, polyester,
Examples thereof include polyester-polyether block copolymers, polyimides, polycarbonates, polyether ether ketones and polyurethane elastomers. Among these thermoplastic resins, polystyrene, styrene-acrylonitrile copolymer, ABS resin, polyvinyl chloride,
It is preferable as a permanent antistatic agent such as polycarbonate.
The amount of the permanent antistatic agent using the polymer having a quaternary ammonium salt group of the present invention added to these thermoplastic resins is usually about 0.5 to 30% by weight, preferably 1 to 15% by weight. .

[0026]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to suppress thermal decomposition of a polymer having a quaternary ammonium salt group due to a nucleophilic attack of a counter ion, and as an antistatic agent for a thermoplastic resin which is injection-molded at a high temperature. It is possible to use polymers with quaternary ammonium bases.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. The processing conditions and the physical property evaluation conditions are shown below.

Example 1 (1) Production of Polymer Having Amino Group 100 g of styrene, 87 g of N, N-dimethylaminoethyl methacrylate, 63.3 g of xylene and 1 g of azobisisobutyronitrile were added to a stirrer, a nitrogen introducing tube, Place in a 2 L reaction vessel fitted with a thermometer and reflux condenser. These were stirred and dissolved, and then heated to 85 ° C. over 1 hour while passing nitrogen gas, and polymerized for 2 hours while maintaining this temperature. Furthermore, 100 g of styrene, N, N
-A mixed solution of 87 g of dimethylaminoethyl methacrylate, 63.3 g of xylene and 1 g of azobisisobutyronitrile was added dropwise over 2 hours, followed by polymerization for 3 hours to obtain a polymer having an amino group. The weight average molecular weight of this polymer was 46,000 in terms of polystyrene.

(2) Production of Polymer Having Quaternary Ammonium Base Next, N, N was added to the obtained polymer having an amino group.
-After adding 110 g of dimethylacetamide for dilution,
A mixture of 170.7 g of diethyl sulfate, 110 g of polyethylene glycol (average molecular weight 200) and 55 g of polyethylene glycol (average molecular weight 6000) was added dropwise over 1 hour to carry out quaternization. Continue to 220 ℃
The mixture was gradually heated up to 50 mmHg and decompressed to 50 mmHg to remove xylene and N, N-dimethylacetamide.

(3) Counterion exchange reaction of the polymer having a quaternary ammonium salt group The polymer 100 having a quaternary ammonium salt group obtained
Into a 3 L reaction vessel equipped with a stirrer, a thermometer and a dropping funnel, 900 g of ion-exchanged water was stirred and dissolved at room temperature. Subsequently, 685.2 g of a 5 wt% sodium tetrafluoroboron salt aqueous solution (200 equivalent% to the quaternary ammonium base) was added dropwise over 2 hours and stirred.
The resulting water-insoluble polymer was separated, washed with water, and dried to obtain 70 g of a polymer having a quaternary ammonium salt group whose counter ion was BF ₄ ⁻ ion. ¹³ C-NMR of the obtained polymer (solvent: DMSO-d ₆ , CH ₃ CH
₂ SO ₄ ^- signals (15.1ppm, 61.2pp
It was confirmed from the fact that only m) disappeared), the conversion of counterions proceeded quantitatively.

Example 2 Similar to Example 1 (3) except that 1048 g of a 5 wt% hexafluorophosphoric sodium salt aqueous solution was used in place of the 5 wt% tetrafluoroboron sodium salt aqueous solution. how do counterion exchange of the counterion is PF ₆ ^- to obtain a polymer 78.2g having quaternary ammonium bases are ions. ^{13 of the} obtained polymer
C-NMR _{(solvent: DMSO-d 6, CH 3} CH 2 SO
₄ ^- from the signal (15.1ppm, 61.2ppm) only disappearance) of conversion of counter ions it was confirmed that proceeded quantitatively.

Example 3 Example 1 (3) except that 1614.3 g of a 5 wt% hexafluoroantimony sodium salt aqueous solution was used in place of the 5 wt% tetrafluoroboron sodium salt aqueous solution in Example 1 (3). Counter ion exchange was carried out in the same manner as in, to obtain 91 g of a polymer having a quaternary ammonium salt group whose counter ion was SbF ₆ ⁻ ion. ¹³ C-NMR (solvent: DMSO-d ₆ , CH ₃ C
H ₂ SO ₄ ⁻ signal (15.1 ppm, 61.2 pp
It was confirmed from the fact that only m) disappeared), the conversion of counterions proceeded quantitatively.

Example 4 Example 1 (3) except that 1322.3 g of a 5% by weight sodium hexafluoroarsenic salt solution was used in place of the 5% by weight sodium tetrafluoroborate salt solution in Example 1 (3). Counter ion exchange was carried out in the same manner as in, to obtain 85.9 g of a polymer having a quaternary ammonium salt group whose counter ion was SbF ₆ ⁻ ion. ¹³ C-NMR (solvent: DMSO-d ₆ , CH ₃ C
H ₂ SO ₄ ⁻ signal (15.1 ppm, 61.2 pp
It was confirmed from the fact that only m) disappeared), the conversion of counterions proceeded quantitatively.

Example 5 (1) Production of polymer having amino group N, N-dimethylaminoethyl methacrylate 180
g, N, N-dimethylacetamide 180 g and azobisisobutyronitrile 3 g, a stirrer, a nitrogen inlet tube,
Place in a 2 L reaction vessel fitted with a thermometer and reflux condenser. These were stirred and dissolved, then heated to 80 ° C. over 1 hour while passing nitrogen gas, and polymerized for 6 hours while maintaining this temperature. Further, 180 g of N, N-dimethylaminoethyl methacrylate, 180 g of N, N-dimethylacetamide and azobisisobutyronitrile 3
The mixed liquid of g was added dropwise over 2 hours, and then polymerization was performed for 6 hours to obtain a polymer having an amino group.
The weight average molecular weight of this polymer was 64,000.

(2) Production of Polymer Having Quaternary Ammonium Base Next, 353.1 g of diethyl sulfuric acid was added dropwise to the obtained polymer having an amino group over 1 hour for quaternization.

(3) Counterion exchange reaction of a polymer having a quaternary ammonium salt group: After further diluting by adding 720 g of methanol, 943 g of a 40 wt% tetrafluoroboron sodium salt aqueous solution
(150 eq% of quaternary ammonium salt base) was added dropwise at room temperature over 2 hours with stirring. Ion-exchanged water 20
0 g was added with stirring to insolubilize the polymer and separate. Separated polymer is deionized water (20% by weight)
- counterion by reprecipitation with a mixed solvent / methanol (precipitating solvent) system acetone (80 wt%) of BF ₄ ^-
Polymer 6 with quaternary ammonium base as ion
70.8 g was obtained. ¹³ C-NMR of the obtained polymer
_{(Solvent: DMSO-d 6, CH 3} CH 2 SO 4 - signals (15.1ppm, 61.2ppm) disappear only) from the conversion of counter ions was confirmed that proceeded quantitatively.

Comparative Example 1 100 g of the polymer having the quaternary ammonium salt group obtained in Example 1 (2) was dissolved in 100 g of methanol and poured into a large excess of tetrahydrofuran to separate the insoluble polymer, which was washed with tetrahydrofuran. Then, it was dried to obtain 74.8 g of a polymer having a quaternary ammonium salt group whose counter ion was CH ₃ CH ₂ SO ₄ ⁻ ion.

The following tests were carried out on the polymers having a quaternary ammonium salt group obtained in Examples and Comparative Examples. The evaluation results are shown in Table 1.

(Heat resistance) 200 ° C. to 270 ° C. and 200 ° C. by a thermal analyzer (TG-DTA2000G, manufactured by Mac Science, nitrogen atmosphere, temperature rising rate 5 ° C./min)
The weight loss rate at ~ 300 ° C was measured.

(Surface resistance value) The polymer solution adjusted to 20% by weight was applied onto a glass plate and dried to obtain a film. The obtained film was dried at 25 ° C and 50R. H. % (Humidity) for 24 hours, and the surface resistance value after 1 minute at an applied voltage of 500 V was measured (TR8 manufactured by Advantest).
601).

(Discoloration) The above humidity-conditioned film was treated with 300
It was treated at 0 ° C. for 2 minutes and the state of discoloration was observed. ○: No coloring △: Slightly colored ×: Significant coloring

[0042]

[Table 1]

Claims (3)

[Claims] 1. A heat-resistant antistatic agent containing a polymer having a quaternary ammonium salt group, wherein the counter ion of the quaternary ammonium salt group is a monovalent metal fluoride ion. Preventive agent. 2. The heat resistant antistatic agent according to claim 1, wherein the monovalent metal fluoride ion of the counter ion is BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ or SbF ₆ ⁻ . 3. The counterion exchange is performed by adding a metal fluoride alkali metal salt to a polymer having a quaternary ammonium salt group quaternized with a quaternizing agent to carry out counterion exchange. Process for producing heat resistant antistatic agent.