JPS63304060A - Thermoplastic polymer composition having excellent antistaticity - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic polymer composition having high antistaticity, by compounding a hygroscopic neutral metal salt to a composition containing a hydrophobic thermoplastic polymer and a saponified ethylene-vinyl acetate copolymer having low ash and alkali metal contents as essential components. CONSTITUTION:The objective composition can be produced by compounding (A) 0.1-5ps.wt. of a hygroscopic neutral metal salt (e.g. lithium chloride) to 100pts.wt. of a composition composed of (B) 99-80wt.% of a hydrophobic thermoplastic polymer (e.g. polycarbonate), (C) 1-20wt.% of a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20-60mol.%, a saponification degree of the vinyl acetate unit of >=95mol.%, an ash content of <=20ppm and an alkali metal content of <=5ppm and (D) 0-10wt.% of a terminal-blocked polyamide polymer having N1/N2 ratio satisfying the formula II wherein N1 is the number of terminal COOH groups and N2 is the number of terminal carboxylic acid amide groups of formula I (R is 1-22C hydrocarbon group; R' is H or same as R).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermoplastic resin composition having good antistatic properties, particularly to a thermoplastic resin composition useful as engineering plastics.

BACKGROUND OF THE INVENTION Polycarbonate, polyethylene terephthalate, polybutylene terephthalate, modified polyphenylene oxide, and the like are widely used as engineering plastics for mechanical appliance parts, electric/electronic equipment parts, and the like.

Molding resins used in these applications are often required to have antistatic properties, and therefore antistatic agents or antistatic resins as described below are often added.

(1) A method of blending a nonionic or anionic surfactant, (2) A method of blending a saponified ethylene-vinyl acetate copolymer, which is a resin that has antistatic properties and can be melt-molded, (j) A nonionic or anionic interface A method of blending an activator and a saponified ethylene-vinyl acetate copolymer together.

Lki ■ is a method that has been used for a long time.

Documents related to Oxki■ include, for example,
There is a publication No. 223.

The above (documents related to φ include Japanese Patent Application Laid-Open No. 51-5684
Publication No. 7, JP-A-56-14543, JP-A-57
-202338 publication etc.

In addition to the method of preventing static electricity by blending an antistatic agent or antistatic resin, there is also a method of applying an antistatic agent to the surface of the molded product after obtaining the molded product.

Although it is related to a purpose different from the present invention,
1-281147 discloses that a lithium salt compound is blended with a saponified ethylene-vinyl acetate copolymer to produce a single-layer or multilayer molded product, especially a stretched molded product, without pinholes, cracks, or local thickness deviations. The technique to obtain it is shown.

Other documents related to the present invention include JP-A-82-2
Publication No. 2840 describes the number N1 of terminal carboxyl groups -COOH and the terminal carboxylic acid amide group -CONRR' (where R is a hydrocarbon group having 1 to 22 carbon atoms, and Ro is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms). A resin in which a polyamide resin whose ratio to the number N2 of groups (groups) satisfies 100・N2/(N1+N2)≧5 and a saponified ethylene-vinyl acetate copolymer are blended in a weight ratio of 98/2 to 2798. There is a disclosure regarding the composition.

Problems to be Solved by the Invention The above-mentioned conventional methods for preventing static electricity on engineering plastics each have their own problems as described below.

In other words, the above method (2) of blending an anionic surfactant has two problems: the thermal stability of the surfactant at the molding temperature is insufficient, and the antistatic effect decreases over time.1. There are problems such as the possibility that the surfactant may contaminate members that come into contact with the molded article.

Method (2) above, in which a saponified ethylene-vinyl acetate copolymer is blended, does not pose the risk of migration as would be the case when a surfactant is blended, but there is a problem in that antistatic properties are insufficient under low humidity conditions. .

The method (2) above, which uses a surfactant and a saponified ethylene-vinyl acetate copolymer, is also essentially the same as (1) or (2) above.
It's no different from the method.

The method of applying an antistatic agent to the surface of a molded article has the problem that the antistatic effect is lost in a short period of time due to friction and wiping, and that charging during molding cannot be prevented at all.

In view of this situation, the present invention was made to find a thermoplastic resin composition that exhibits an antistatic effect and maintains the antistatic effect even under low humidity conditions.

Means for Solving the Problems The present invention is based on a hydrophobic thermoplastic resin (A) and an ethylene content of 20%.
~60 mol%, degree of saponification of vinyl acetate moiety is 95 mol%
In addition, the essential component is a saponified ethylene-vinyl acetate copolymer (B) with a low ash content and a low alkali metal, which has an ash content of 20 ppm or less and an alkali metal content of 5 ppm or less, and has a terminal carboxyl group -COOH. The ratio of the number N1 to the number N2 of the terminal carboxylic acid amide group -CONRR' (where R is a hydrocarbon group having 1 to 22 carbon atoms, and Ro is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms) is 100I
A hygroscopic neutral metal salt (y) o, t~ is added to 100 parts by weight of a resin composition (X) optionally containing an end-blocked polyamide resin (C) satisfying N2/(10N2)≧5. 5 parts by weight of a thermoplastic resin composition with good antistatic properties.''

The present invention will be explained in detail below.

The thermoplastic resin composition of the present invention consists of a resin composition (X) and a hygroscopic neutral metal salt (Y).

- Resin composition (X) - The resin composition (X) contains a hydrophobic thermoplastic resin (A) and a saponified ethylene-vinyl acetate copolymer of low ash and low alkali metal (B) as essential components, and A capped polyamide resin (C) is an optional component.

B-A hydrophobic thermoplastic resin (A) includes polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyester carbonate, modified polyphenylene oxide,
AB l! 1 resin, AS resin, polypropylene, etc.

The saponified ethylene-vinyl acetate copolymer (B) with low ash and low alkali metal has an ethylene content of 20 to 60
A composition having a saponification degree of 95 mol % or more of acetic acid and vinyl moieties is used. Ethylene content is 20
If it is less than 60 mol %, the compatibility with the hydrophobic thermoplastic resin (A) will decrease, while if it exceeds 60 mol %, the effect of improving antistatic properties will be insufficient. If the degree of saponification of the vinyl acetate portion is less than 95 mol%, thermal stability during molding will be insufficient.

The saponified copolymer may contain a small amount of a comonomer such as an α-olefin other than ethylene, an unsaturated carboxylic acid compound, an unsaturated nitrile, an unsaturated amide, or an unsaturated sulfonic acid compound.

Generally, a saponified ethylene-vinyl acetate copolymer is produced by saponifying an ethylene-vinyl acetate copolymer with an alkali catalyst. However, the industrial water and reagents used contain metal salts as impurities, and the saponification catalyst (alkali metal hydroxide) remains as an acetate of the alkali metal even after the reaction. Therefore, these impurities and alkali metal acetates are removed from the wood 1 precipitated from the saponification solution.
It will be included in the floor.

It is essential to use a saponified ethylene-vinyl acetate copolymer (B) suitable for the present invention in which such impurities and alkali metal acetate are reduced to below a certain limit.

The above-mentioned ash refers to the dry saponified ethylene-vinyl acetate copolymer taken in a platinum evaporating dish, carbonized using an electric heater and gas burner, placed in an electric furnace at 400°C, heated to 700°C, and then heated to 700°C. After being completely incinerated at 700°C for 3 hours, it is taken out from the electric furnace, left to cool for 5 minutes, and then left in a desiccator for 25 minutes to determine the activity of the ash content.

The above-mentioned alkali metals are determined by atomic absorption spectrometry using a solution in which the saponified ethylene-vinyl acetate copolymer is incinerated in the same manner as in the case of ash measurement, and the ash is dissolved in an acidic aqueous solution of hydrochloric acid under heating. .

The saponified ethylene-vinyl acetate copolymer (B) suitable for the purpose of the present invention has an ash content of 2 as defined above.
It is necessary that the ash content be 0 ppm or less, preferably 10 ppm or less; if the ash content exceeds 20 ppm, the resulting molded product will have a significant decrease in mechanical strength and deterioration in surface appearance. It is preferable for the ash content to be as low as possible within the above-mentioned allowable range, but from an industrial standpoint there is a limit to refining, so the lower limit is about i ppm.

The saponified ethylene-vinyl acetate copolymer (B) not only needs to have an ash content within the above-mentioned allowable range, but also needs to have an alkali metal content of 5 ppm or less, preferably 3 ppm or less. If the alkali metal content exceeds 5 ppm, the mechanical strength of the molded product obtained will decrease significantly and the surface appearance will deteriorate in the same manner as described above. It is preferable that the alkali metal content be as low as possible within the above allowable range,
From an industrial standpoint, there is a limit to refining, so the lower limit is 0.
．． It will be about 5 ppm.

Ultimately, the saponified ethylene-vinyl acetate copolymer (B) in the present invention is required to have the above-mentioned copolymer composition, have an ash content of 20 ppm or less, and an alkali metal content of 5 PP or less. It will be done.

The saponified ethylene-vinyl acetate copolymer (B) with a low ash number and low alkali metal content described above is a saponified ethylene-vinyl acetate copolymer powder produced by saponifying an ethylene-vinyl acetate copolymer, It is obtained by thoroughly washing the particles or pellets with an aqueous solution of an acid, particularly a weak acid, to remove salts that cause ash and alkali metals, and more preferably washing with water to remove the acid attached to the resin, and drying.

Examples of weak acids used include acetic acid, propionic acid, glycolic acid, lactic acid, adipic acid, azelaic acid, geltaric acid, succinic acid, benzoic acid, isophthalic acid, and terephthalic acid. Usually, pKa at 25°C is 3.5. The above are useful.

In addition, after performing the treatment with the above-mentioned weak acid, before or after washing with water, dilute strong acids such as oxalic acid, maleic acid, and other organic acids with a pKa of 2.5 or less at 25°C, phosphoric acid, etc.
It is desirable to further treat with an aqueous solution such as sulfuric acid, nitric acid, hydrochloric acid, etc., which makes the alkali metal removal more efficient.

--Polyamide, C The terminal-blocked polyamide resin (C) has the number N1 of terminal carboxyl groups -COOH and the terminal carboxylic acid amide group -CONRR' (where R is a hydrocarbon group having 1 to 22 carbon atoms, R'' is The ratio of hydrogen atoms or hydrocarbon groups having 1 to 22 carbon atoms to the number N2 is 100・N2/ (N1+N2
)≧5, that is, lactams with three or more membered rings, ε
- A polyamide obtained by polymerization or copolymerization of an amino acid or a dibasic acid with a diamine, etc., whose terminal carboxyl group is modified with an N-substituted amide is used. Mono-substituted amide modification (R' is a hydrogen atom) is practical, but di-substituted amide modification may also be used.

The above-mentioned polyamide resin (C) is prepared by combining a polyamide raw material with ■ a monoamine having 1 to 22 carbon atoms, or ■ a carbon number 1
It can be obtained by polycondensation in the presence of ~22 monoamines and monocarboxylic acids having 2 to 23 carbon atoms.

Polyamide raw materials include lactams (ε-caprolactam, enanthractam, capryllactam, lauryllactam, α-pyrrolidone, α-piperidone, etc.), ω-
Amino acids (6-aminocaproic acid, 7-aminononanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, etc.), dibasic acids (adipic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, undecanedione) Acid, dodecadionic acid, hexadecadionic acid, hexadecenedioic acid, eicosanedionic acid, eicosadienedionic acid, diglycolic acid, 2.2.4-trimethyladipic acid, xylylenedicarboxylic acid, 1.4-cyclohexanedicarboxylic acid acid, terephthalic acid, isophthalic acid, etc.), diamines (hexamethylene diamine, tetramethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2゜2.4- or 2,4.4-1 remethyl) xamethylene diamine,
bis-(4,4'-aminocyclohexyl)methane, metaxylylene diamine, etc.).

Examples of monoamines having 1 to 22 carbon atoms include aliphatic monoamines (methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecyl amines, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, octadecylamine, eicosylamine, tocodylamine, etc.), alicyclic monoamines (cyclohexylamine, methylcyclohexylamine, etc.), aromatic monoamines ( benzylamine, β-phenylethylamine, etc.), symmetrical secondary amines (N,N-dimethylamine, N,N-diethylamine, N,N-dipropylamine, N,N-dibutylamine, N,N-diethylamine,
N,N-dioctylamine, N,N-didecylamine, etc.), mixed secondary amines (N-methyl-N-ethylamine,
N-Methyl-N-butylamine, N-methyl-N-octadecylamine, N-ethyl-N-hexadecylamine, N-ethyl-N-octadecylamine, N-propyl-N-hexadecylamine, N-methyl- N-cyclohexylamine, N-methyl-N-benzylamine, etc.).

Examples of monocarboxylic acids having 2 to 23 carbon atoms include aliphatic monocarboxylic acids (acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthate S, caprylic acid, capric acid, pelargonic acid, undecanoic acid, lauric acid, tridecane) acids, myristic acid, myristoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, behenic acid, etc.), alicyclic monocarboxylic acids (cyclohexanecarboxylic acid, methylcyclohexanecarboxylic acid, etc.), aromatic monocarboxylic acids Examples include carboxylic acids (benzoic acid, toluic acid, ethylbenzoic acid, phenylacetic acid, etc.).

In addition to the above monoamines or monoamines and monocarboxylic acids, aliphatic diamines (ethylene diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine,
Heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, tridecamethylene diamine, hexadecamethylene diamine, octadecamethylene diamine, 2,2.4- or 2,4 ．．
4-) dibutylhexamethylenediamine, etc.), alicyclic diamines (cyclohexanediamine, methylcyclohexanediamine, bis-(4,4'-aminocyclohexyl)methane, etc.), aromatic diamines (xylylenediamine, etc.), aliphatic diamines Dicarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecadionic acid, tetradecadionic acid, hexadecadioic acid, octadeca dionic acid, octadecenedioic acid, eicosandioic acid, eicocenedioic acid, tocosandioic acid, 2,2.4-)dibutyladipic acid, etc.)
Diamines and dicarboxylic acids such as , alicyclic dicarboxylic acids (1,4-cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, xylylene dicarboxylic acid, etc.) can coexist. .

The reaction for producing the polyamide resin (C) can be started using the polyamide raw material according to a conventional method. Can be added in stages. The carboxylic acid and amine may be added simultaneously or separately.

The amount of carboxylic acid and amine used is 1 mole of polyamide raw material (as the amount of carboxyl group and amino group).
1 mol of 2 to 20 meq, preferably 1 mol of 3 to 19 meq, per 1 mol of monomer or monomer unit constituting the repeating unit (the equivalent of the amino group is 1=1 when reacting with 1 equivalent of carboxylic acid to form an amide bond) (The amount of amino groups forming this is defined as 1 equivalent).

If the amount used is too small, it will not be possible to produce a polyamide resin suitable for the purpose of the present invention, while if it is too large, the physical properties of the polyamide resin will be adversely affected.

The reaction pressure is preferably 400 Torr or less, preferably 300 Torr or less at the end of the reaction. If the pressure at the end of the reaction is high, the desired relative viscosity cannot be obtained.

The time for the reduced pressure reaction is desirably 0.5 hours or more, and usually 1 to 2 hours.

100 NRR' that the polyamide resin (C) has at the end
The hydrocarbon group represented by R or R' in the group includes aliphatic hydrocarbon groups (methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, octadecyl group, eicosyl group, tocosyl group), alicyclic hydrocarbon group (cyclohexyl group, methylcyclohexyl group, cyclohexylmethyl group, etc.), aromatic hydrocarbon group (phenyl group, tolyl group, benzyl group, β-phenylethyl group, etc.)
can be given.

-CONRR' of terminal -〇〇H group of polyamide resin
The conversion rate to groups can be determined by the presence of an amine or an amine and a carboxylic acid during the production of polyamide resin.
mllH, but more than 5 moles of -COOH group, especially 1
It is preferable that 0 mol% or more is converted to -CONRR° groups, and the amount of unconverted 1000H groups is 50 geq/g polymer or less, especially 40 geq
/g·polymer or less is preferable; if the degree of this conversion is small, the desired effect cannot be expected. - Increasing the degree of force conversion is not disadvantageous in terms of physical properties, but it makes manufacturing difficult, so it is best to limit the amount of unmodified terminal carboxyl groups to 1 JLeq/g of polymer. .

The hydrocarbon groups represented by R and R in the -00NRR' group can be measured by gas chromatography after hydrolyzing the polyamide resin (C) using hydrochloric acid. -C
OOH groups can be measured by dissolving the polyamide resin (C) in benzyl alcohol and titrating the solution with 0, IN caustic soda.

In addition to the above-mentioned 100NRR' group, the terminal groups of the polyamide resin (C) include 1000H group and -MHz group derived from the polyamide raw material.

The terminal amino group may or may not be modified, but it is preferably modified with the above-mentioned hydrocarbon group because of good fluidity and melt stability.

-NHλ group can be measured by dissolving the polyamide resin (C) in phenol and titrating with 0.05N hydrochloric acid.

The relative viscosity of the polyamide resin (C) [ηrell is J
Concentration 1% in 98% sulfuric acid according to IS K E1810
, 2 to 6, preferably 2 to 5, measured at a temperature of 25°C
It is. If the relative viscosity is too low, it will be difficult to form into strands and chips, which will be inconvenient in manufacturing. - If the relative viscosity is too high, moldability will be poor.

The proportion of each resin component in the resin composition (X) is 99 to 80% by weight of the hydrophobic thermoplastic resin (A), low ash number, low alkali metal ethylene-vinyl acetate. Saponified copolymer (
B) 1 to 20% by weight and end-blocked polyamide resin (
C) Desirably 0 to 10% by weight.

If the proportion of the saponified substance (B) is less than this range, the surface of the molded product will become rough, and the antistatic effect due to the blending of the saponified substance (B) and the resin layer of the hygroscopic neutral metal salt (Y) will be reduced. It is difficult to recognize the retention effect inside the hydrophobic thermoplastic resin (
The original purpose of having A) as the main component is diminished, and the moldability during long-run molding is reduced.

Polyamide resin (C) does not necessarily need to be used, but if used in combination when the amount of saponified ethylene-vinyl acetate copolymer (B) is relatively large within the above range, the saponified product (B) will increase. Deterioration in long run formability due to compounding may be effectively prevented in some cases. When the polyamide resin (C) is used in combination, the blending ratio is at most 10% by weight as mentioned above, and the ratio to the saponified ethylene-vinyl acetate copolymer (B) is equal to or less, especially 10 to 10% by weight. 50
It is usually expressed as % by weight. Polyamide resin (C)
If more than 10% by weight is blended, the original purpose of having the hydrophobic thermoplastic resin (A) as the main component will be diminished, and
This has a disadvantageous effect in terms of antistatic effect.

Monohygroscopic neutral metal salt (Y) - As the hygroscopic neutral metal salt (Y), lithium salts such as lithium chloride, lithium bromide, lithium iodide, lithium nitrate; calcium chloride, calcium bromide, Examples include calcium salts such as calcium nitrate; magnesium salts such as magnesium chloride and magnesium bromide; and the like.

The amount of the hygroscopic neutral metal salt (Y) based on 100 parts by weight of the above-mentioned resin composition (X) is selected from the range of 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, If the proportion is less than 0.1 part by weight, the antistatic effect will be insufficient, while if the proportion exceeds 5% by weight, the physical properties of the molded product will deteriorate.

- Melt molding - The above resin composition (X) and the hygroscopic neutral metal salt (Y
) may optionally contain a plasticizer (
(polyhydric alcohol, etc.), stabilizers, crosslinking substances (epoxy compounds, polyvalent metal salts, inorganic or organic polybasic acids or their salts, etc.), fillers, dyes and pigments, reinforcing materials (glass fiber, carbon fiber, etc.), Known additives such as lubricants and foaming agents can be blended. Other thermoplastic resins can also be blended. In addition, a small amount of other conventionally used antistatic agents can be used in combination without impairing the spirit of the present invention.

Melt molding methods include injection molding and extrusion molding (
Extrusion molding for pelletization (including extrusion coating), blow molding, etc. can also be adopted.

Although the melt molding temperature varies depending on the type of each resin, in the case of injection molding, the molding temperature of the main component hydrophobic thermoplastic resin (A) is adopted.

When extrusion molding is employed, the resin composition of the present invention can also be coextruded with other thermoplastic resins.

Molded products obtained from the resin composition of the present invention include mechanical appliance parts, electric/electronic equipment parts, automobile parts, ship/aircraft parts,
It is useful for a variety of applications including optical and watch parts.

Function In the present invention, the hydrophobic thermoplastic resin (A) constitutes the main component of the resin composition (X).

Saponified ethylene-vinyl acetate copolymer with low ash and low alkali metal content (B) and hygroscopic neutral metal salt (Y)
In this case, the saponified material (
Since B) also plays the role of preventing the neutral metal salt (Y) from detaching from the surface of the molded product, the antistatic effect of the molded product will last for a long time.

The end-capped polyamide resin (C) ensures long-run moldability when the hydrophobic thermoplastic resin (A) is blended with a saponified ethylene-vinyl acetate copolymer (B) having a low ash content and low alkali metal content. play a role.

EXAMPLES Next, the thermoplastic resin composition of the present invention will be further explained with reference to Examples. Hereinafter, "part" and "1%" are expressed on a weight basis unless otherwise specified.

[Resin used] The following resin was prepared as a resin constituting the resin composition (X).

0#I A (A-1) Polybutylene terephthalate (manufactured by Mitsubishi Chemical Industries, Ltd. "NOVADUR 501" 0J) (A-2) Polyethylene terephthalate (manufactured by Nihon Nini Pet Co., Ltd. rRT533J) (A-3) Polycarbonate (manufactured by Mitsubishi Chemical Corporation, rRT533J) (Tubalex 7025AJ, manufactured by Kasei Kogyo Co., Ltd., melting point 250°C) (A-4) Modified polyphenylene oxide (Noryl 731J, manufactured by Engineering Plastics Co., Ltd.) (A-5) ABS resin (Tuffley, manufactured by Mitsubishi Monsanto Chemical Co., Ltd.) / ') S T F X -610]
) (A-8) Polypropylene (Tubatic-P4100YJ manufactured by Mitsubishi Chemical Industries, Ltd.) (B-1) 1000 parts of a 40% methanol solution of ethylene-vinyl acetate copolymer with an ethylene content of 40 mol% was charged into a pressure-resistant reactor. , and heated to 110° C. with stirring.Next, 40 parts of a 6% methanol solution of sodium hydroxide and 2,500 parts of methanol were continuously charged, and while methyl acetate as a by-product and excess methanol were distilled out of the system, The saponification reaction was carried out for .5 hours to obtain a saponified ethylene-vinyl acetate copolymer with a degree of saponification of the vinyl acetate portion of 99.0%.

While adding 450 parts of 30% water-containing methanol to the saponified liquid, excess methanol was distilled off, resulting in a resin concentration of 39%.
A water/methanol (composition ratio 3/7) solution was prepared.

The water/methanol mixture of the saponified ethylene-vinyl acetate copolymer at a liquid temperature of 50°C was passed through a nozzle with a four-layer pore size at a rate of 1.5 Jl/hr to water/methanol maintained at 5°C. (Mixing ratio 9/1) a solid-liquid tank (width 100
It was extruded into a strand shape with a length of 4000 mm and a depth of 100 mm. After coagulation, the strand-like material is cut with a cutter through a take-up roller (linear speed 2 m/in) attached to the end of the coagulation liquid tank, and a white, porous material with a diameter of 4 mm and a length of 4 mm is cut. pellets were obtained.

The ash content of this saponified ethylene-vinyl acetate copolymer pellet is 7,400 ppm, and the sodium metal content is 48
00 ppm.

Next, a washing operation (weak acid washing) in which 100 parts of the pellets were immersed in 300 parts of a 0.3% acetic acid aqueous solution and stirred at 30° C. for 1 hour was repeated twice. Next, after filtering the slurry, the obtained pellets were mixed with 300 parts of water again to form a slurry, and the washing operation was performed by stirring at 30°C for 1 hour (
Washing with water) was repeated three times.

The ash content of the saponified ethylene-vinyl acetate copolymer pellets after the above washing operation was 6 pp+i, and the sodium metal content was 2.79 ppm.

This saponified ethylene-vinyl acetate copolymer (B-1
).

(B-2) In addition, prior to the above water washing, a washing operation (strong acid washing) was performed once in which the pellets after the weak acid washing were further immersed in 230 parts of a 0.003% phosphoric acid aqueous solution and stirred at 30 ° C. for 1 hour. Then, the same water washing operation as in the case of production (B-1) was repeated three times.

The ash content of the obtained saponified ethylene-vinyl acetate copolymer pellets was 10 pp, and the sodium metal content was 1.4.
It was pp■.

This ethylene-vinyl acetate monopolymer saponified product (B-
2).

(B-3) For comparison, saponified ethylene-vinyl acetate copolymer pellets with an ash content of 30 ppm and a sodium metal content of 10 ppm were prepared according to the manufacturing method of (B-1) above (however, the number of washings was reduced). Manufactured.

This saponified ethylene-vinyl acetate copolymer (B-3
).

In addition, the ash content and sodium metal were determined in accordance with the following.

<Ash content> Approximately 80 g of the dried sample was accurately weighed, and approximately 10 g of it was placed in a platinum evaporation dish with constant weight, and carbonized with an electric heater. After carbonization, approximately 10 g of each sample was added and the same operation was repeated. Finally, I heated it with a gas burner and baked it until there was no smoke.

The platinum evaporation dish was placed in an electric furnace at about 400°C, most of it covered with a magnetic crucible lid, and the temperature was gradually raised to 700°C.

After being held at 700°C for 3 hours to completely incinerate, it was taken out from the electric furnace, allowed to cool for 5 minutes, and then left in a desiccator for 25 minutes, and the ash content was accurately weighed.

<Sodium metal> Approximately 10 g of the dried sample was accurately weighed, placed in a platinum crucible, and incinerated in the same manner as above. Special grade hydrochloric acid 21 for Platinum Luppo
Then, 3 ml of pure water was added and heated with an electric heater to dissolve.

The above solution was poured into a 50 ml volumetric flask with pure water, and pure water was added roughly up to the marked line to prepare a sample for atomic absorption spectrometry.

Atomic absorbance was measured using a separately prepared standard solution (sodium metal TPP, 0.5N hydrochloric acid) as a control solution, and the amount of sodium metal was determined from the absorbance ratio. The measurement conditions are as follows.

Equipment: Hitachi Model 180-30 Atomic Absorption/Flame Spectrophotometer Wavelength: 589.0 nm Flame: Acetylene-air-vacuum polyamide, C (C-1) 200-liter autoclave-caprolactam 6Qk
g, water 1.2kg, octadecylamine 3.33meq
/so I and stearic acid 3.39 seq/mol
The reactor was sealed in a nitrogen atmosphere, heated to 250°C, and reacted under pressure with stirring for 2 hours.Then, the pressure was gradually released to 200 Torr, and the reaction was carried out under reduced pressure for 2 hours. .

Next, after nitrogen was introduced and the pressure was restored to normal pressure, stirring was stopped and strands were taken out and made into chips. Unreacted upper particles were extracted and removed using clean water and dried.

The characteristic values of the obtained polyamide resin (C-1) were as follows.

Terminal carboxyl group: 20 ILeq/8 @ polymer terminal amino group: 21 geq/g, polymer 10
0.82/ (Nl+N2): 60 relative viscosity [η
rell: 2.89 (C-2) The amount of octadecylamine charged was 8.81 eq/PengO.
1, except that 8.81 meq/mol of adipic acid was used instead of stearic acid 3.3θ■eq/Oboro 1 (
A polyamide resin (C-2) having the following characteristic values was obtained in the same manner as in the case of C-1) production.

Terminal carboxyl group: 20 ILeq/g Polymer terminal amino group: 21 Rod eq/g Polymer 100 N2/ (N1+N2): 80 Relative viscosity [77rell: 2.50 (C-3) The amount of octadecylamine charged was 8. 78 recommended eq/fat 0
1, the charging of stearic acid was omitted, and the pressure at the end of the polymerization reaction was 180 Torr.A polyamide resin (C-3) having the following characteristic values was obtained in the same manner as in the production of (C-1). .

Terminal carboxyl group: 9 JLeq/g, polymer terminal amine 7 groups: 68 peq/g, polymer 1
00・N2/ (N1+N2): 87 Relative viscosity [η
rell: 2.40 [Composition] The resin components (A), (B) and (C) constituting the resin composition (X) are prepared in advance in the following ratio using a tumbler using pellets or chips. Mixed. At that time, 1.0 part of lithium chloride (Y-1) dissolved in 1.0 part of water was added, and then dried at 100°C for 5 hours. however,
For Example 7, Comparative Example 14, Example 8, Comparative Example 17, Example 9, and Comparative Example 20, lithium chloride (Y-1
) After adding 2.0 parts dissolved in 2.0 parts of water, 1
It was dried at 00°C for 5 hours.

Using (A-1) Example I A-1: 90 parts, B-1: 10 parts, C-1
: 2 parts Example 2 A-1: 90 parts, B-2: 10
Part, C-2: 2 parts Example 3 A-1: 90 parts, B-2
: 10 parts, C-3: 2 parts Comparative Example I A-1: 100 parts (without Y-1) Comparative Example 2 A-1: 100 parts Comparative Example 3 A-1: 90 parts, B-1 Comparative Example 4 A-1: 130 parts, B-3: 10 parts, C-
1: 2 parts Comparative Example 5 A-1rtoo part,
C-1: 2 parts Example 4 A-1: 135 parts, B-2: 5 parts Comparative example 6 A-1: 95 parts, B-3:
Example 5 using (A-2) A-2: 9 parts, B-2: 10 parts, C-1
: 3 parts Comparative Example 7 A-2: 100 parts (without Y-1) Comparative Example 8 A-2: 100 parts Comparative Example 9 A-2: 90 parts, B-2: 10 parts (without Y-1) 1) Non-blended) (A-3) Example 6 A-3: 90 parts, B-2: 10 parts, C-2
: 2 parts Comparative Example 10 A-3: 100 parts (without Y-1) Comparative Example 11 A-3: 100 parts Comparative Example 12 A-3: 90 parts, B-2: 10 parts (without Y-1) 1) No formulation) (Using A-0 Example 7 A-4: 90 parts, B-2: 10 parts Comparative Example 1
3 A-4: 100 parts (with Y-1) Comparative Example 14 A-4: 100 parts Comparative Example 15 A-4: 90 parts, B-2: 10 parts (without Y-1) Using (A-5) Example 8 A-5: 98 parts, B-2: 4 parts Comparative Example 18
Comparative Example 17 A-5: 100 parts Comparative Example 18 A-5: 9 parts, B-2+4 parts (Y-t) not added) (A -6) Example 9 A-8: 9 Et parts, B-2: 4 parts Comparative Example 1
9 A-8: 100 parts (just Y-1 not added) Comparative Example 2 OA-8: 100 parts Comparative Example 21 A-8: 98 parts, B-2: 4 parts (just Y-t not added) , in the formulation of Example 2, lithium chloride (Y-1
) In place of 1.0 part, add the following hygroscopic neutral metal salt (Y)0
．． 5 parts were used.

Example 1O Calcium chloride (Y-2) Example 11
Lithium nitrate (Y-3) Example 12 Calcium nitrate (Y-4) [Melt molding conditions] <Pelletization> For the resin composition of the above formulation, a uniaxial extrusion molding machine equipped with a screw with dullage (screw diameter 40 m layer) Extrusion molding was carried out using the following extrusion temperature using a pelletizer, and pelletization was performed using a pelletizer.

When using (A-1) When using 240℃ (A-2) When using 270℃ (A-3) When using 290℃ (A-4) When using 280℃ (A-5) When using 230℃ (A-8) When using 230℃ <Injection molding> Using the pellets obtained above, injection molding was performed using a 5-ounce class in-line screw type injection molding machine under the following temperature conditions. A disk-shaped sample piece with a length of 3.2 mm and a diameter of 100 square layers was obtained. The injection pressure is 9 (1'-1200
kg/...2, injection time was set to 8 seconds, mold temperature was set to 50° C., and cooling time was set to 20 seconds.

When using (A-1) 220/ 240/ 240
When using °C (A-2) 250/ 270/ 27
When using 0℃ (A-3) 280/290/2
When using 90℃ (A-4) 280/ 290/
When using 290℃ (A-5) 220/ 240/
When using 240℃ (A-6) 220/240
/ 240℃ (The numerical values are, from left to right, cylinder rear temperature (C1) / cylinder front temperature (C2) / nozzle temperature) [Test/judgment items] (Item l) Surface resistance of injection molded product 4 hours continuous injection molding The appearance of the sample piece after molding was observed, and the surface resistance of the sample piece was measured after being left at 20° C. and 65% RH for one day and two weeks after molding.

The surface resistance was measured in accordance with the surface resistance test method in the JIS standard, general test methods for thermosetting plastics.

[Results] The results are shown in Table 1. The appearance judgment in the table is based on the following criteria.

0: Good Δ: Yellowing of the resin due to decomposition is observed.

×: Roughness is observed on the surface.

Table 1 Example 13 As saponified ethylene-vinyl acetate copolymer (B) with low ash and low alkali metal content, ash content is 8 ppm, sodium metal content is 2.9 ppm, ethylene content is 30 mol%,
An experiment was carried out according to Example 1 except that a saponified ethylene-vinyl acetate copolymer (B-4) having a degree of saponification of the vinyl acetate portion of 39.0% was used. However, (A-4) /
The blending ratio of (B-4)/(Y-1) was 95 parts, 75 parts, and 71.0 parts.

The appearance judgment is O, and the surface resistance is -r: 2 after being left for one day.
．． oxto"n, 2 weeks number 1j tte te 1, O
X toI3fL-t' Arata.

Effects of the Invention A molded article obtained by melt molding using the thermoplastic resin composition of the present invention exhibits excellent antistatic properties, and the antistatic effect is exhibited even at low humidity. Moreover, even though the hygroscopic neutral metal salt (Y) is blended, it is hardly detached from the surface of the molded product, so the antistatic effect is maintained for a long period of time.

In addition, by blending a saponified ethylene-vinyl acetate copolymer (B) with a low ash content and a low alkali metal content as an antistatic resin or a Ti antistatic agent and a hygroscopic neutral metal salt (Y), Long-run moldability is ensured, and the appearance of the resulting molded product is not impaired.

Claims (1)

[Claims] 1. Hydrophobic thermoplastic resin (A) and ethylene content is 2.
A low ash/low alkali metal ethylene-vinyl acetate copolymer with a saponification degree of 0 to 60 mol%, a saponification degree of the vinyl acetate portion of 95 mol% or more, an ash content of 20 ppm or less, and an alkali metal content of 5 ppm or less. The saponified product (B) is an essential component, the number Nl of terminal carboxyl groups -COOH and the terminal carboxylic acid amide group -CONRR' (where R is a hydrocarbon group having 1 to 22 carbon atoms, R' is a hydrogen atom or a carbon number 1) ~22 hydrocarbon groups) to the number N2 is 100・N2
/(N1+N2)≧5 0.1 to 5 parts by weight of a hygroscopic neutral metal salt (Y) to 100 parts by weight of a resin composition (X) containing as an optional component an end-blocked polyamide resin (C) satisfying the following. A thermoplastic resin composition with good antistatic properties. 2. The resin composition (X) is a hydrophobic thermoplastic resin (A) 9
9-80% by weight, low ash, low alkali metal ethylene
Thermoplastic resin composition according to claim 1, characterized in that it consists of 1 to 20% by weight of saponified vinyl acetate copolymer (B) and 0 to 10% by weight of end-blocked polyamide resin (C). .