JP3369336B2 - Method for producing low resistivity polycarbonate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low-resistivity polycarbonate, and more particularly to a method for producing a low-resistivity polycarbonate applied to various molded products such as electrical insulating parts.

[0002]

2. Description of the Related Art Conventionally, general formula:

[Chemical 5] [Wherein R _{1 to} R ₆ are hydrogen, a hydrocarbon group, a phenyl compound substituent or a halogen group, and n is an integer of 30 or more] is a typical example of a polycarbonate having excellent transparency. With respect to mechanical properties as well, it has a high impact strength and exhibits a high heat distortion temperature, so it is used as various molded products. In addition, because it has excellent electrical insulation properties, it is expanding its field of use as an electrical insulation component, but due to its excellent electrical insulation properties, it is easy to store electricity and electrostatic charging is a problem, so it can be used for precision electrical components. Making it difficult. Therefore, a low molecular type antistatic agent such as a surfactant is added to the polycarbonate, or a conductive filler such as a conductive carbon and / or a metal filler is mixed and dispersed to impart antistatic performance. ing.

[0003]

However, when a surfactant is mixed and dispersed, the antistatic performance depends on the hydrophilic group of the surfactant present on the surface of the molded article.
Surfactants that are water-soluble reduce their antistatic performance by washing with water and / or repeated rubbing. Further, although the amount of the surfactant transferred to the surface influences the antistatic performance, in the case of the polycarbonate (T _g = 150 ° C.) represented by the general formula [1] having a high glass transition temperature, it is almost the interface at room temperature. No surface migration of activator occurs. Further, although some of the surfactants themselves usually have good heat resistance, most of them cannot be effectively used 100% because decomposition and volatilization occur at a temperature lower than the molding processing temperature.

On the other hand, when the conductive filler is filled, a certain amount of addition is required to exhibit the antistatic performance, so that the melt viscosity is increased and the workability is significantly reduced. In addition, the physical properties (mechanical properties, etc.) of the material itself change and the transparency is lost.

The present invention provides a method for producing a low-resistivity polycarbonate having a permanent antistatic property for the purpose of solving such problems.

[0006]

Means for Solving the Problems and Actions / Effects The method for producing a low resistivity polycarbonate according to the present invention has the general formula:

[Chemical 6] [Wherein R _{1 to} R ₆ are hydrogen, a hydrocarbon group, a phenyl compound substituent or a halogen group, and n is an integer of 30 or more]

[Chemical 7] [In the formula, at least one of R _{7 to} R ₁₁ represents an alkylammonium salt substituent or a sulfonate substituent, and the others represent hydrogen, a hydrocarbon group, a hydroxyl group or a halogen group] Group carboxylic acids and general formulas:

[Chemical 8] [In the formula, at least one of R _{12 to} R ₁₉ represents an alkylammonium salt substituent or a sulfonate substituent, and the others represent hydrogen, a hydrocarbon group, a hydroxyl group or a halogen group] At least one carboxylic acid selected from the group consisting of ferulcarboxylic acids, and a general formula:

[Chemical 9] [Wherein R _{20 to} R ₂₄ are hydrogen, a hydrocarbon group or a halogen group] and at least one monovalent phenol compound represented by the formula is reacted in a molten state at a predetermined ratio.

For the polycarbonate represented by the general formula [1], for example, the monovalent aromatic carboxylic acid [2]
With the monovalent phenol compound [4],
The reaction for forming low resistivity polycarbonate is presumed to be based on the following reaction mechanism.

[0008]

[Chemical 10]

[0009]

[Chemical 11]

First, as shown in the formula (a), the polycarbonate [1] is cleaved with a monovalent aromatic carboxylic acid [2], and has a carboxyl group derived from the monovalent carboxylic acid [2] at the terminal. The product [A] and the product [B] having an active group derived from the carbonate bond of the polycarbonate [1] at the end are produced. Next, as shown in the formula (b), the monovalent phenol compound [4] and the product [B] are combined to produce the product [C].

In this way, polycarbonate [1]
It is considered that since the hydrophilic phenyl substituent derived from the alkylammonium salt or the sulfonate is introduced at the terminal of, the compound exhibits antistatic performance. Further, in the case of divalent diphenylcarboxylic acid [3], a hydrophilic phenyl substituent derived from an alkylammonium salt or a sulfonate is introduced at the terminal or the bond of polycarbonate [1], so that the antistatic property is similarly prevented. It is considered to show performance.

In this reaction, the monovalent phenol compound [4] is used in combination to react with the monovalent aromatic carboxylic acid [2] or divalent diphenylcarboxylic acid [3]. This is because the low-resistivity polycarbonate to be used causes problems such as discoloration and foaming during melting. Moreover, a polycarbonate having an antistatic property is not produced only by the monovalent phenol compound [4].

Molded products produced from the low-resistivity polycarbonate obtained by the production method of the present invention have a hydrophilic phenyl substituent that contributes to the antistatic performance uniformly on the surface as well as on the inside. And / or permanently possesses antistatic performance upon repeated rubbing. Further, since no conductive filler is added to this molded product, the mechanical properties and transparency peculiar to polycarbonate are maintained.

In the method for producing a polycarbonate of the present invention, the polycarbonate [1] is added to the polycarbonate in an amount of 0.01 to 30% by weight of the at least one carboxylic acid, and a molar ratio of a carboxyl group to the carboxylic acid. It is preferable to react with at least one monohydric phenol compound in an equivalent ratio of 1 or less.

When the content of the carboxylic acid is less than 0.01%, the reaction does not proceed sufficiently, so that a low-resistivity polycarbonate exhibiting antistatic performance is not produced, and when it exceeds 30%, the molecular weight of the polycarbonate is extremely reduced, This is because the desired low resistivity polycarbonate cannot be produced due to discoloration. Further, when the molar equivalent ratio of the phenol compound [4] exceeds 1, the phenol compound [4]
This is because the reaction between the monovalent aromatic carboxylic acid [2] or the divalent diphenylcarboxylic acid [3] and the polycarbonate [1] is hindered and the reaction does not proceed sufficiently.

In the production method of the present invention, as a method for producing the low resistivity polycarbonate in a melting reaction, for example, the polycarbonate [1] is melted at a predetermined temperature, and then a monovalent aromatic carboxylic acid [2] is used. And / or a method of adding or injecting a divalent diphenylcarboxylic acid [3] and a monovalent phenol compound [4],
The above-mentioned monovalent aromatic carboxylic acid [2] and / or divalent diphenylcarboxylic acid [3] and monovalent phenol compound [4] are added to and mixed with the pellets or powder of the polycarbonate [1] to obtain a master. There is a method of producing pellets or master powder and melting and reacting the produced one at a predetermined temperature, but any method may be used. In addition, in the present reaction, if the melting reaction time becomes long, it may cause burns or yellow stains. Therefore, the melting reaction time is preferably about 1 to 10 minutes.

The polycarbonate [1] used in the present invention is produced, for example, by using the following bisphenols by a phosgene method, a transesterification method or the like.

[Bisphenols] 2,2-bis (4-
Hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5dibromophenyl) propane, 2,2
-Bis (4-hydroxy-3,5-dichlorophenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 4,4'-dihydroxydiphenylmethane, 1-1 bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxy) Phenyl)
Cyclohexane, 4,4-dihydroxydiphenylmethylisobutylmethane, 2,2-bis (4-hydroxyphenyl) phenylethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) difluoromethane, bis (4-hydroxyphenyl) )
Such as dichloromethane. In addition, 2 of these bisphenols
More than one kind may be polymerized.

[Holgen Method] An interfacial polymerization method in which the alkaline aqueous solution of bisphenol is turbid in, for example, methylene chloride, and phosgene is blown into the turbid solution to promote the polymerization reaction of these bisphenol and phosgene.

[Transesterification Method] The above-mentioned bisphenol and diphenyl carbonate mixed at a predetermined mixing ratio are heated and melted without using a solvent, and the melted bisphenol and diphenyl carbonate are dephenolized under reduced pressure at high temperature. A method of polycondensation by a transesterification reaction accompanied by a reaction.

The monovalent aromatic carboxylic acid [2] used in the present invention includes 4-carboxyphenyltrimethylammonium iodide, 3-carboxyphenyltrimethylammonium iodide and 2-carboxyphenyltrimethylammonium iodide. , 1,2-sulfobenzoic acid sodium salt, 1,3-sulfobenzoic acid sodium salt, 1,4-sulfobenzoic acid sodium salt, and the like, and as the divalent diphenylcarboxylic acid [3], iodide 2,2 '-Dicarboxybiphenyl 3-trimethylammonium, 2,2'-dicarboxybiphenyl 4-trimethylammonium, 2,2'
-Dicarboxybiphenyl 5-trimethylammonium, 2,2'-dicarboxybiphenyl 6-trimethylammonium iodide, 1- (2,2'-dicarboxybiphenyl) iodide, 2- (trimethylammonium) ethane and the like. .

The monohydric phenol compound [4] used in the present invention includes p-tert-butylphenol, 4-ethylphenol, 4-bromophenol, 4-chlorophenol, 2-butylphenol and 4-propyl. Examples include phenol.

[0023]

EXAMPLES Next, specific examples of the method for producing a low resistivity polycarbonate according to the present invention will be described.

Example 1 A polycarbonate prepared by using 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 28,000 as a monomer raw material was melted at about 290 ° C., and a weight ratio to the melted polycarbonate was used. 0.05% 4-carboxyphenyltrimethylammonium iodide and 0.006% by weight (molar equivalent ratio of carboxyl groups: 0.1) of p-tert-butylphenol were added and reacted.

Example 2 A polycarbonate prepared by using 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 28,000 as a monomer raw material was melted at about 290 ° C., and a weight ratio to the melted polycarbonate was used. 5% 4-carboxyphenyltrimethylammonium iodide and 0.3% by weight ratio (molar equivalent ratio of carboxyl groups: 0.1) of p-tert-butylphenol were added and reacted.

(Example 3) A polycarbonate obtained by using 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 30,000 as a monomer raw material was melted at about 290 ° C, and a weight ratio to the melted polycarbonate was used. 10% 4-carboxyphenyltrimethylammonium iodide and 0.5% by weight ratio (molar equivalent ratio of carboxyl groups: 0.1) of p-tert-butylphenol were added and reacted.

Example 4 Polycarbonate having 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 25,000 as a monomer raw material was melted at about 290 ° C., and a weight ratio to the melted polycarbonate was used. 5% of iodide 2,2'-dicarboxybiphenyl-4
-Trimethylammonium and 0.4% by weight ratio (molar equivalent ratio of carboxyl groups: 0.1) of p-tert-butylphenol were added and reacted.

Example 5 Polycarbonate having 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 27,000 as a monomer raw material was melted at about 290 ° C., and a weight ratio to the melted polycarbonate was used. And 5% by weight of 4-carboxyphenyltrimethylammonium iodide and 5% by weight of 2,2′-dicarboxybiphenyl-4-trimethylammonium iodide and 0.6% by weight (molar equivalent ratio of carboxyl groups). : 0.1)
P-tert-butylphenol was added and reacted.

Example 6 A polycarbonate prepared from 2,2-bis (4-hydroxyphenyl) propane having a number average molecular weight of 27,000 as a monomer raw material was melted at about 290 ° C., and a weight ratio to the melted polycarbonate was used. Then, 30% of 4-carboxyphenyltrimethylammonium iodide and 3.8% by weight (molar equivalent ratio of carboxyl group: 0.1) of p-tert-butylphenol were added and reacted.

Comparative Example As a comparative example, the number average molecular weight was 2
2000 Polycarbonate using 2,2-bis (4-hydroxyphenyl) propane as a monomer raw material (standard P
C) was used.

[Measurement of Physical Properties] The low resistivity measurements of the polycarbonates according to the above-mentioned Examples and Comparative Examples were carried out in accordance with ASTM Test Method D257. Further, other mechanical properties were also measured according to the ASTM test method. On the other hand, the molecular weight after the reaction is evaluated by a method of converting from melt viscosity (Angew. Chem. 68, 633 (1956)), and all molecular weights are number average molecular weights. The results are shown in Table 1.

[0032]

[Table 1]

Claims (2)

(57) [Claims] 1. A general formula: [Wherein R _{1 to} R ₆ are hydrogen, a hydrocarbon group, a phenyl compound substituent or a halogen group, and n is an integer of 30 or more], and the polycarbonate is represented by the general formula: [In the formula, at least one of R _{7 to} R ₁₁ represents an alkylammonium salt substituent or a sulfonate substituent, and the others represent hydrogen, a hydrocarbon group, a hydroxyl group or a halogen group] Group carboxylic acids and general formula: [In the formula, at least one of R _{12 to} R ₁₉ represents an alkylammonium salt substituent or a sulfonate substituent, and the others represent hydrogen, a hydrocarbon group, a hydroxyl group or a halogen group]. At least one carboxylic acid selected from the group consisting of ferulcarboxylic acids, and a compound of the general formula: [Wherein R _{20 to} R ₂₄ are hydrogen, a hydrocarbon group or a halogen group] and at least one monohydric phenol compound is reacted in a molten state at a predetermined ratio to give a low resistivity. Method for producing polycarbonate. 2. The polycarbonate [1], wherein the weight ratio to the polycarbonate is 0.01 to 30% of the at least one carboxylic acid, and the molar equivalent ratio of the carboxyl group to the carboxylic acid is 1 or less. The method for producing a low-resistivity polycarbonate according to claim 1, which comprises reacting with at least one monohydric phenol compound.