antistatic agent

Abstract

To provide an antistatic agent which has low resistance and high antistatic ability.SOLUTION: There are provided an antistatic agent which contains a polyester resin that is a polycondensation product of an alcohol component containing aromatic diol and / or alicyclic diol and polyalkylene glycol having hydroxyl groups at both terminals, and a carboxylic acid component, and is obtained by subjecting a carboxy group to metal chlorination treatment; and an antistatic agent which contains a metal chlorinated polyester resin that is a polycondensation product of an alcohol component containing aromatic diol and / or alicyclic diol and polyalkylene glycol having hydroxyl groups at both terminals, and a carboxylic acid component containing a metal salt of a carboxylic acid.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antistatic agent to be blended in a resin composition used for resin molded products in fields such as the electronics industry. [Background technology]

[0002] The electronics industry has seen remarkable development in recent years, and the performance requirements for resin molded products used in this field are increasing. Due to their excellent electrical insulation properties, various resins are used for the exteriors, housings, circuit boards, etc. of various electronic devices. However, due to their high insulating properties, they are prone to becoming charged due to friction, etc. This has many adverse effects, such as making the exteriors and housings more likely to attract dust, and causing electronic circuit boards to malfunction. Therefore, resins used in electronic devices contain antistatic agents and are designed to suppress charging.

[0003] Patent Document 1 discloses an invention relating to an antistatic resin composition obtained by mixing 99 to 70 parts by weight of any thermoplastic resin with 1 to 30 parts by weight of a polyether ester obtained by condensing a poly(alkylene oxide) glycol having a number average molecular weight of 200 to 20,000, a glycol having 2 to 8 carbon atoms, and a polycarboxylic acid and / or a polycarboxylic acid ester having 4 to 20 carbon atoms.

[0004] Patent Document 2 discloses an invention relating to an antistatic agent, which is a polyetherester (A) containing, as essential raw material components, an aromatic polycarboxylic acid or an alkyl ester thereof, a polyalkylene glycol, an alkylenediol, and a bifunctional phenol compound, and is characterized in that the ratio of the number of alkylene groups derived from the alkylenediol in the polyetherester (A) to the number of aromatic nuclei derived from the bifunctional phenol compound is in the range of 2 to 3,000.

[0005] Patent Document 3 discloses an invention relating to an antistatic agent characterized by comprising a polymer compound having a structure in which a diol, a dicarboxylic acid, a compound having an ethylene oxide chain and hydroxyl groups at both ends, and a polycarboxylic acid compound are bonded via ester bonds. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-57153 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-192018 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-44225 Summary of the Invention [Problem to be solved by the invention]

[0007] However, conventional antistatic agents cannot sufficiently improve the antistatic ability of a resin composition unless they are blended in large amounts.

[0008] The present invention relates to an antistatic agent having low resistance and high antistatic ability. [Means for solving the problem]

[0009] In order to solve the problems of the conventional technology, the present inventors have conducted research focusing on high molecular weight compounds, i.e., resins, as antistatic agents, rather than low molecular weight compounds with antistatic properties such as surfactants. As a result, they have found that using a resin with a highly polar structure and further controlling the terminal structure of the polymer chain that constitutes the resin is effective in improving the antistatic effect, and have thus completed the present invention.

[0010] The present invention provides [1] An antistatic agent containing a polyester resin which is a polycondensation product of an alcohol component containing an aromatic diol and / or an alicyclic diol and a polyalkylene glycol having hydroxyl groups at both ends, and a carboxylic acid component, and in which the carboxyl groups are treated with a metal chloride; and [2] An antistatic agent containing a metal chloride polyester resin, which is a polycondensation product of an alcohol component containing an aromatic diol and / or an alicyclic diol and a polyalkylene glycol having hydroxyl groups at both ends, and a carboxylic acid component containing a metal salt of a carboxylic acid. Regarding. [Effects of the Invention]

[0011] The antistatic agent of the present invention has the effect of having low resistance and high antistatic ability. DETAILED DESCRIPTION OF THE INVENTION

[0012] The antistatic agent of the present invention is a polycondensate obtained using, as the alcohol component, a highly polar aromatic diol and / or alicyclic diol and polyethylene glycol having hydroxyl groups at both ends, and is significantly characterized in that it contains a polyester resin (polyester resin P) in which the carboxyl groups have been treated with a metal chloride.

[0013] While the exact reasons why the antistatic agent of the present invention exhibits excellent antistatic performance are unclear, it is believed to be as follows. Polyester resins are high-polar polymeric compounds with numerous ester bonds in their main chain structure. Furthermore, the presence of carboxyl or hydroxyl groups at the ends of the polymer chains contributes to their high polarity. Therefore, focusing on this high polarity, polyester resins have traditionally been used as antistatic agents for various resin molded products. While it is known that using highly polar monomers as the constituent monomers of polyester resins is effective in achieving higher antistatic performance, the present inventors focused on the end groups of polyester resins. Because the end groups have a higher degree of freedom than the central portion of the main chain, they are believed to be able to effectively prevent charge migration. Therefore, by converting the carboxyl groups in the end groups of polyester resins from their usual acid form to metal salts incorporating an alkali metal or the like, the highly flexible end groups can be made even more conductive, resulting in a higher antistatic effect.

[0014] As described above, the polyester resin P is a polycondensation product of an alcohol component and a carboxylic acid component, and is a polyester resin in which the carboxyl groups in the polycondensation product have been treated with a metal chloride.

[0015] The alcohol component contains an aromatic diol and / or an alicyclic diol from the viewpoint of maintaining the antistatic effect and the resin properties of a resin molded product containing the antistatic agent of the present invention.

[0016] The aromatic diols include those of formula (I):

[0017] [ka]

[0018] (wherein OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y are the average number of moles of alkylene oxide added and are each a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, and even more preferably 4 or less.) Preferred is an alkylene oxide adduct of bisphenol A represented by the following formula:

[0019] Examples of alicyclic diols include hydrogenated bisphenol A, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanediol, and 1,2-cyclohexanediol. Among these, hydrogenated bisphenol A or 1,4-cyclohexanedimethanol is preferred, and two or more of them may be used in combination.

[0020] The content of the aromatic diol or the alicyclic diol, or when both are contained, the total content of the aromatic diol and the alicyclic diol in the alcohol component is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and is preferably 99 mol% or less, more preferably 98 mol% or less, even more preferably 97 mol% or less.

[0021] The alcohol component further contains a polyalkylene glycol having hydroxyl groups at both ends.

[0022] Examples of polyalkylene glycols having hydroxyl groups at both ends include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and among these, polyethylene glycol is preferred.

[0023] The number average molecular weight of the polyalkylene glycol having hydroxyl groups at both ends is preferably 100 or more, more preferably 500 or more, and even more preferably 800 or more, from the viewpoint of antistatic effect and maintaining the resin properties of a resin molded article incorporating the antistatic agent of the present invention, and is preferably 10,000 or less, more preferably 7,000 or less, and even more preferably 4,000 or less, from the viewpoint of antistatic effect.

[0024] The content of the polyalkylene glycol having hydroxyl groups at both ends is preferably 15% by mass or more, more preferably 25% by mass or more, even more preferably 35% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, of the total amount of the alcohol component and the carboxylic acid component.

[0025] Examples of alcohol components other than aromatic diols, alicyclic diols, and polyalkylene glycols include linear or branched aliphatic diols having 2 to 20 carbon atoms, and trihydric or higher alcohols.

[0026] Examples of the carboxylic acid component include aromatic dicarboxylic acid compounds, linear or branched aliphatic dicarboxylic acid compounds, alicyclic dicarboxylic acid compounds, trivalent or higher aromatic carboxylic acid compounds, and trivalent or higher aliphatic or alicyclic carboxylic acid compounds. Carboxylic acid compounds include not only carboxylic acids but also anhydrides that decompose during the reaction to produce acids, and alkyl esters having 1 to 3 carbon atoms.

[0027] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0028] Examples of the trivalent or higher aromatic carboxylic acid compound include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0029] The content of aromatic carboxylic acid compounds, including aromatic dicarboxylic acid compounds and trivalent or higher aromatic carboxylic acid compounds, in the carboxylic acid component is preferably 70 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, and still more preferably 95 mol% or more, but 100 mol% or less.

[0030] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0031] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) is preferably 0.6 or more, more preferably 0.7 or more, even more preferably 0.75 or more, and is preferably 1.2 or less, more preferably 1.15 or less.

[0032] The polyester resin can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, in the presence of an esterification promoter, a polymerization inhibitor, etc., at a temperature preferably of 120°C or higher and 250°C or lower.

[0033] Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, more preferably 1 part by mass or less, per 100 parts by mass of the alcohol component and the carboxylic acid component combined. Examples of the esterification promoter include gallic acid. The amount of the esterification promoter used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, more preferably 0.1 parts by mass or less, per 100 parts by mass of the alcohol component and the carboxylic acid component combined. Examples of the polymerization inhibitor include 4-tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0034] In the present invention, the polyester resin may be modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins grafted or blocked with phenol, urethane, epoxy, or the like, by the methods described in JP-A Nos. 11-133668, 10-239903, and 8-20636.

[0035] The softening point of the polyester resin before the carboxyl groups are treated with a metal chloride is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 90°C or higher, and preferably 200°C or lower, more preferably 185°C or lower, even more preferably 170°C or lower.

[0036] The acid value of the polyester resin before the carboxyl groups are treated with a metal chloride is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more, even more preferably 20 mgKOH / g or more, and is preferably 70 mgKOH / g or less, more preferably 50 mgKOH / g or less, even more preferably 40 mgKOH / g or less, even more preferably 35 mgKOH / g or less.

[0037] The softening point and acid value of the polyester resin can be adjusted appropriately by the type and amount of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, cooling rate, etc. One polyester resin may be used alone or two or more polyester resins may be used in combination, and when two or more polyester resins are used in combination, the physical properties of the mixture thereof are preferably within the above-mentioned ranges.

[0038] From the viewpoint of antistatic effect, the polyester resin P is preferably an amorphous polyester resin. The crystallinity of a resin is expressed by the crystallinity index, which is defined as the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, i.e., the value of [softening point / maximum endothermic peak temperature]. A crystalline resin is a resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less. On the other hand, an amorphous resin is a resin in which no endothermic peak is observed, or if an endothermic peak is observed, the resin has a crystallinity index of more than 1.4, preferably more than 1.5, more preferably 1.6 or more, or less than 0.6, preferably 0.5 or less. The crystallinity of the resin can be adjusted by the types and ratios of raw material monomers, production conditions (e.g., reaction temperature, reaction time, cooling rate), etc. The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the observed endothermic peaks.

[0039] The metal salt treatment of the carboxy group refers to a treatment in which the carboxy group in the polyester resin P forms a metal salt.

[0040] Examples of metal salts formed by carboxy groups in polyester resin P include alkali metal salts such as lithium, potassium, and sodium, and alkaline earth metal salts such as magnesium, calcium, and barium, with alkali metal salts being more preferred. Treatment with two or more of these metal salts may be used. Therefore, the metal chloride treatment of carboxy groups in polyester resin P is preferably treatment with at least one alkali metal selected from the group consisting of lithium, potassium, and sodium.

[0041] Any known method may be used for the metal chloride treatment of the carboxyl group. Examples include a method in which a metal hydroxide is added to a synthesized polyester resin in a molten state at high temperature, or a method in which an aqueous solution of a metal hydroxide is added to a polyester resin dissolved in an organic solvent. Among these, from the viewpoint of efficiently obtaining a polyester resin in which the terminal carboxyl groups are metal chlorides, the method in which an aqueous solution of a metal hydroxide is added to a polyester resin dissolved in an organic solvent is preferred. Examples of organic solvents used to dissolve the polyester resin include ketone-based solvents such as dialkyl ketones having an alkyl group with 1 to 3 carbon atoms, such as acetone and methyl ethyl ketone; ether-based solvents such as dibutyl ether and tetrahydrofuran; and ester-based solvents such as ethyl acetate and isopropyl acetate. Among these, dialkyl ketones having an alkyl group with 1 to 3 carbon atoms, such as acetone and methyl ethyl ketone, are preferred, with methyl ethyl ketone being more preferred.

[0042] The metal chloride treatment is preferably carried out so that the metal chloride degree of the carboxyl groups of the polyester resin P is 30 mol % or more and 100 mol % or less. From the viewpoint of antistatic performance, the metal chloride degree is more preferably 50 mol % or more, even more preferably 70 mol % or more, and even more preferably 90 mol % or more. Here, the metal chloride degree is expressed as the proportion of carboxy groups that have been treated with metal chloride to the carboxy groups in the polyester resin P. For example, when the metal chloride treatment is performed using a metal hydroxide, the metal chloride degree is calculated using the following formula.

[0043]

number

[0044] In the present invention, the polyester resin P may be a metal chloride polyester resin obtained by using a monomer in which the carboxy group is a metal salt, such as sodium terephthalate, as the carboxylic acid component used in synthesizing the polyester resin, i.e., a metal chloride polyester resin which is a polycondensate of an alcohol component containing an aromatic diol and / or alicyclic diol and a polyalkylene glycol having hydroxyl groups at both ends, and a carboxylic acid component containing a metal salt of carboxylic acid.

[0045] The softening point of the polyester resin P is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 65°C or higher, and preferably 200°C or lower, more preferably 160°C or lower, even more preferably 125°C or lower.

[0046] The content of the polyester resin P in the antistatic agent of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, up to 100% by mass.

[0047] The antistatic agent of the present invention may contain other additives in addition to the polyester resin P, provided that the additives do not impair the effects of the present invention. Specific examples include various active agents such as anionic, cationic, nonionic, and amphoteric surfactants, olefin-based rubbers such as ethylene propylene rubber, inorganic fillers and pigments such as talc, antioxidants, and antibacterial agents.

[0048] From the viewpoint of the material properties of resin molded products, the resin composition to be blended with the antistatic agent of the present invention preferably contains a thermoplastic resin such as ABS resin (acrylonitrile-butadiene-styrene resin), polypropylene, polyethylene, polystyrene, polyethylene terephthalate, or polymethyl methacrylate.

[0049] There is no limitation on the method for blending the antistatic agent of the present invention into a resin composition as an antistatic agent, and known methods such as kneading or coating can be used, but from the viewpoint of fully exhibiting the antistatic performance of the antistatic agent of the present invention, it is preferable to use it by kneading. For example, when kneading it into a resin composition containing a thermoplastic resin, the antistatic agent of the present invention is added to a powdery resin composition, and then mixed with a Henschel mixer, a Nauta mixer, or the like, and then pelletized using a kneading extruder as necessary, and the resulting mixture is molded using an injection molding machine, thereby obtaining a resin composition to which the antistatic agent has been added by kneading.

[0050] The amount of the antistatic agent of the present invention to be blended is not particularly limited, but is preferably 1% by mass or more and 20% by mass or less in a resin composition containing a thermoplastic resin, for example. Because the antistatic agent of the present invention has high antistatic ability, a high antistatic effect can be obtained even with a small amount compared to conventional antistatic agents. [Example]

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Physical properties of resins and the like can be measured by the following methods.

[0052] [Number average molecular weight of polyalkylene glycol] It is calculated from the hydroxyl value measured in accordance with JIS K 1557.

[0053] [Softening point of resin] Using a flow tester "CFT-500EX" (Shimadzu Corporation), 1 g of sample is heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa is applied by the plunger, and the sample is extruded from a nozzle 1 mm in diameter and 1 mm in length. The plunger depression distance of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[0054] [Maximum endothermic peak temperature of resin] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan Co., Ltd.), weigh 0.01-0.02 g of sample into an aluminum pan, cool the sample from room temperature (20°C) to 0°C at a rate of 10°C / min, and maintain the sample at that temperature for 1 minute. Then, measure the endothermic peak while increasing the temperature to 180°C at a rate of 10°C / min. The temperature of the peak with the largest area among the observed endothermic peaks is taken as the maximum endothermic peak temperature.

[0055] [Acid value of resin] Measurement is performed based on the method of JIS K0070:1992, except that the measurement solvent is changed from the ethanol and ether mixed solvent specified in JIS K0070:1992 to tetrahydrofuran.

[0056] Polyester Resin Production Example 1 The inside of a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen. The alcohol components, carboxylic acid components other than trimellitic anhydride, an esterification catalyst, and an esterification promoter shown in Table 1 were added. The mixture was heated to 235°C under a nitrogen atmosphere with stirring and maintained at 235°C for 3 hours. The pressure inside the flask was then reduced to 8.3 kPa and maintained for 1 hour. The mixture was then returned to atmospheric pressure and cooled to 220°C. Trimellitic anhydride was added and maintained at 220°C for 1 hour. The pressure inside the flask was then reduced to 8.3 kPa and the reaction was continued until the desired softening point was reached, yielding amorphous polyester resins (Resins A1, A2, A4 to A6). Resin A1 was used as the antistatic agent for Comparative Example 2 in the test examples described below.

[0057] Polyester Resin Production Example 2 The inside of a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and the alcohol component, carboxylic acid component other than fumaric acid, esterification catalyst, and esterification co-catalyst shown in Table 1 were added. The mixture was heated to 235°C under nitrogen atmosphere with stirring and maintained at 235°C for 3 hours. The pressure inside the flask was then reduced to 8.3 kPa and maintained at 8.3 kPa for 1 hour. The mixture was then returned to atmospheric pressure and cooled to 190°C. Fumaric acid and a polymerization inhibitor were added, and the mixture was heated to 210°C over 2 hours. The mixture was maintained at 210°C for 1 hour. The pressure inside the flask was then reduced to 8.3 kPa and the reaction was continued until the desired softening point was reached, yielding an amorphous polyester resin (Resin A3).

[0058] Polyester Resin Production Example 3 The inside of a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and the alcohol components, carboxylic acid components other than trimellitic anhydride, esterification catalyst, and esterification co-catalyst shown in Table 1 were added. Under a nitrogen atmosphere, the temperature was raised to 235°C while stirring, and after holding at 235°C for 3 hours, the pressure in the flask was further reduced and held at 8.3 kPa for 1 hour. After that, the pressure was returned to atmospheric pressure, cooled to 215°C, 184 g of trimellitic anhydride was added, and the temperature was held at 215°C for 1 hour. Next, the pressure in the flask was reduced, and the reaction was continued at 8.3 kPa until the desired softening point was reached, yielding an amorphous polyester resin (Resin A7).

[0059] The physical properties of the obtained resins are shown in Table 1. Measurement of the maximum endothermic peak temperature was also attempted, but no endothermic peak was observed for any of the resins.

[0060] [Table 1]

[0061] Example 1 100 g of Resin A1 was placed in a four-neck flask equipped with a reflux condenser, a stirrer (Three-One Motor BL300, manufactured by Shinto Scientific Co., Ltd.), and a thermocouple. 100 g of Resin A1 was mixed with 100 g of methyl ethyl ketone at 30°C to dissolve the resin. Next, 38.5 g of a 5% by mass aqueous solution of sodium hydroxide (enough to convert all carboxyl groups in Resin A1 into metal salts) was added and stirred for 60 minutes. The temperature was then raised to 65°C, and the pressure was gradually reduced from 80 kPa to 30 kPa to distill off the methyl ethyl ketone. When the amount of distilled off methyl ethyl ketone exceeded 50 g, the temperature was further increased under reduced pressure, ultimately reaching 150°C. The resin composition was then depressurized while still in a molten state to remove the methyl ethyl ketone. After cooling to room temperature, the mixture was further vacuum-dried for 12 hours to obtain a metal chloride polyester resin.

[0062] Examples 2 to 9 and Comparative Example 1 Metal chloride polyester resins were obtained in the same manner as in Example 1, except that the type of amorphous polyester resin and the type and amount of metal hydroxide aqueous solution used were changed as shown in Table 2.

[0063] Test Example Using the metal chloride polyester resin obtained in the Examples and Comparative Examples as an antistatic agent, 13 parts by mass of the antistatic agent was mixed with 87 parts by mass of ABS resin (Toyolac 100, manufactured by Toray Industries, Inc.), and the mixture was injection-molded using an injection molding machine (Japan Steel Works, J-75E model) heated to 230°C to prepare 100 mm × 100 mm × 3 mm test pieces made of a thermoplastic resin composition containing the antistatic agent.

[0064] Furthermore, as Comparative Example 2, a test piece was prepared in the same manner using Resin A1 as an antistatic agent. Also, as Reference Example 1, an ABS resin (Toyolac 100, manufactured by Toray Industries, Inc.) was injection molded as is using an injection molding machine (Japan Steel Works, J-75E model) heated to 230°C to prepare a test piece measuring 100 mm × 100 mm × 3 mm.

[0065] The prepared test specimens were surface-cleaned by immersion in ion-exchanged water. The surface resistivity of the test specimens after wiping off the water was measured by the following method to evaluate the antistatic performance of the antistatic agent. The results are shown in Table 2. The smaller the surface resistivity, the better the antistatic performance.

[0066] [Measurement of surface resistivity] The test specimen was vacuum dried at room temperature for 24 hours, then left to stand in a temperature and humidity chamber at 23°C and 50% humidity for 24 hours to condition the humidity. Next, in the temperature and humidity chamber, the surface resistivity (Ω / □) of the test specimen was measured when 500 V was applied using a High Resistance Meter 4329A (Agilent Technologies).

[0067] [Table 2]

[0068] The above results show that, compared to Comparative Example 1, in which a metal chloride polyester resin not using polyalkylene glycol was added, and Comparative Example 2, in which an amorphous polyester resin in which the carboxy group was not metal chloride was added, in Examples 1 to 9, the resin compositions to which a metal chloride polyester resin was added as an antistatic agent had low resistance and exhibited high antistatic performance. [Industrial Applicability]

[0069] The antistatic agent of the present invention is suitably used in resin compositions used for resin molded products and the like in fields such as the electronics industry.

Claims

1. An antistatic agent comprising a polyester resin which is a polycondensation product of an alcohol component containing an aromatic diol and / or alicyclic diol and a polyalkylene glycol having hydroxyl groups at both ends, and a carboxylic acid component, and in which the carboxyl groups are treated with a metal chloride.

2. 2. The antistatic agent according to claim 1, wherein the degree of metal chloride of the carboxyl groups of the polyester resin is 30 mol % or more and 100 mol % or less.

3. 2. The antistatic agent according to claim 1, wherein the acid value of the polyester resin before the carboxyl groups are treated with a metal chloride is 15 mgKOH / g or more and 70 mgKOH / g or less.

4. An antistatic agent comprising a metal chloride polyester resin, which is a polycondensate of an alcohol component containing an aromatic diol and / or alicyclic diol and a polyalkylene glycol having hydroxyl groups at both ends, and a carboxylic acid component containing a metal salt of a carboxylic acid.

5. 5. The antistatic agent according to claim 1, wherein the carboxylic acid component contains 70 mol % or more and 100 mol % or less of an aromatic carboxylic acid compound.

6. 5. The antistatic agent according to claim 1, wherein the number average molecular weight of the polyalkylene glycol is 100 or more and 10,000 or less.

7. 5. The antistatic agent according to claim 1, wherein the content of the polyalkylene glycol is 15% by mass or more and 70% by mass or less of the total amount of the alcohol component and the carboxylic acid component.

8. 5. The antistatic agent according to claim 1, wherein the metal chloride is at least one alkali metal selected from the group consisting of lithium, potassium, and sodium.

9. 5. The antistatic agent according to claim 1, wherein the content of the aromatic diol or the alicyclic diol, or when both are contained, the total content of the aromatic diol and the alicyclic diol in the alcohol component is 50 mol % or more and 99 mol % or less.

10. The aromatic diol is represented by formula (I): 【Chemistry 1】 (wherein OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y are positive numbers each representing the average number of moles of alkylene oxide added, and the sum of x and y is 1 or more and 16 or less.) 5. The antistatic agent according to claim 1, which is an alkylene oxide adduct of bisphenol A represented by the formula:

11. 5. The antistatic agent according to claim 1, wherein the alicyclic diol is hydrogenated bisphenol A and / or 1,4-cyclohexanedimethanol.

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