JP2973453B2 - Method for producing polyester having antistatic properties - Google Patents

Description

The present invention relates to a method for producing a polyester, and more particularly, to a method for producing a polyester having excellent transparency and antistatic properties.

[Prior Art] Polyesters, especially polyethylene terephthalate, polybutylene terephthalate or poly-1,4-cyclohexane dimethylene terephthalate and polyesters based on these have excellent physical and chemical properties, and are used for fibers and films. Alternatively, it is widely used as a sheet or a molded product thereof. However, since such polyesters are easily charged with static electricity, there is a disadvantage that various troubles are liable to occur in the production process of fibers, films or various molded products, or in the production process, and when the products are used.

Hitherto, for the purpose of imparting antistatic properties to polyesters, it has been proposed to mix various metal sulfonic acid compounds and metal sulfonic acid compounds with various metal salt compounds or polyoxyalkylene glycols. For example, JP-A-50-53465 and JP-A-52-134662 disclose simply blending a metal sulfonic acid salt compound into polyester, and JP-A-54-6049 discloses a metal sulfonic acid compound. Alkaline earth metal halides or sulfates, and JP-A-60-38123 discloses the incorporation of a polyester with a metal sulfonate compound and a metal salt of a higher fatty acid.

However, in these methods, the antistatic performance of the polyester is insufficient, and the compatibility of the sulfonic acid metal salt compound with the polyester is not sufficient, or because of the other metal salt compound to be blended, the resulting fiber, Films or other molded products may form coarse surface protrusions,
There are drawbacks such as the transparency is significantly impaired. Japanese Patent Publication No. 44-31828 discloses an example in which a polyoxyalkylene glycol is substantially used. However, in this case, the obtained polyester is cloudy and has poor transparency, which is not preferable. Furthermore, JP-A-52-47069, JP-A-52-47069
-47072 discloses a sulfonic acid metal salt compound and a molecular weight of 400
Illustrated are films with compositions of ~ 8000 polyoxyalkylene glycols. In this case, a certain degree of antistatic property can be imparted, but there is a disadvantage that the transparency of the film is inferior.

[Problems to be Solved by the Invention] As a result of intensive studies in view of the above problems, the present inventors have found that
The present invention has been reached.

That is, an object of the present invention is to provide a method for producing a polyester for improving antistatic properties without impairing surface defects and transparency of fibers, films or sheets obtained from polyester, and various molded products. is there.

[Means for Solving the Problems] An object of the present invention described above is to produce a polyester by reacting a dicarboxylic acid or an ester-forming derivative thereof with a glycol, to prepare a quaternary ammonium compound and an alkali metal or an alkaline earth metal. PH using a pH adjuster selected from hydroxides or acetates of 7.
The method can be achieved by a method for producing a polyester having antistatic properties, wherein a metal sulfonic acid salt compound adjusted to 5 to 13.0 is added to a reaction system at an arbitrary stage of a polyester production step.

The polyester of the present invention refers to a polyester produced by a transesterification or esterification reaction of a dicarboxylic acid or an ester derivative thereof with a glycol and a polycondensation reaction. The type of polyester is not particularly limited as long as it can be formed into fibers, films, sheets and other molded products. Preferred polyesters that can be formed into fibers, films, sheets and other molded products are those in which an aromatic dicarboxylic acid is used as a dicarboxylic acid component, and aliphatic and alicyclic glycols are preferably used as a glycol component. Is done. For example, polyethylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, polyethylene-
P-oxybenzoate, polyethylene-1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylate, polyethylene-1,2-bis (2-phenoxy) ethane-4,4'-di Examples thereof include carboxylate, polyethylene-2,6-naphthalene dicarboxylate, polyethylene isophthalate, and poly-1,4-cyclohexane dimethylene terephthalate. Among them, polyethylene terephthalate is preferable.

Of course, these polyesters may be homopolyesters or copolyesters, and the copolymerizable components include, for example, diethylene glycol, neopentyl glycol, p-xylylene glycol, 1,4-
Diol components such as cyclohexanedimethanol, 5-sodium sulforesorcin, adipic acid, sebacic acid,
Dicarboxylic acid components such as phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid and 5-sodium sulfoisophthalic acid; polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid; and oxy acids such as p-oxyethoxybenzoic acid And carboxylic acid components.

To produce a polyester comprising the above dicarboxylic acid or its derivative and a glycol, any method is employed. For example, a polyethylene terephthalate composed of a terephthalic acid component and an ethylene glycol component will be described. A glycol ester of terephthalic acid is obtained by directly esterifying terephthalic acid with ethylene glycol or transesterifying dimethyl terephthalate with ethylene glycol. Alternatively, it is most commonly produced by a first-stage reaction for producing the low polymer and a second stage in which the reaction product of the first stage is subjected to a polycondensation reaction.

In the present invention, a suitable amount of an alkali metal such as lithium, sodium and potassium, an alkaline earth metal such as magnesium, calcium, strontium and barium and a hydride such as zinc, manganese and cobalt are used for the esterification reaction or the transesterification reaction. , Alcoholates, chlorinated products and glycol-soluble salts of monocarboxylic acids, and titanium compounds, tin compounds and the like are preferably used as catalysts. Particularly preferred are lithium acetate, sodium acetate, calcium acetate, magnesium acetate, zinc acetate, manganese acetate, manganese chloride and the like. A typical catalyst used in the polycondensation reaction is an antimony or germanium compound soluble in glycol, and specifically, antimony trioxide, germanium oxide and the like are preferable. Further, a titanium compound may be used. Further, phosphorus compounds as various coloring inhibitors generally used in the production of polyester can also be preferably used, and as the phosphorus compounds, phosphoric acid, phosphorous acid,
Examples thereof include phosphonic acids and derivatives thereof, and specifically, phosphoric acid, phosphorous acid, trimethyl phosphate,
Examples thereof include tributyl phosphate, triphenyl phosphate, mono- or dimethyl phosphate, dimethyl phenylphosphonate, and diethyl phenylphosphonate. Further, these catalysts and color inhibitors may be used alone or in combination of two or more.

The sulfonic acid metal salt compound of the present invention is represented by the following formula.

R-SO ₃ Mm R: alkyl group or alkylaryl group or aryl group M: alkali metal or alkaline earth metal m: 1 or 1/2 when R of the sulfonic acid metal salt compound is an alkyl group or an alkylaryl group May have a linear or branched side chain. Particularly, from the viewpoint of compatibility with polyester, R is preferably an alkyl group or an alkylaryl group, and more preferably a metal sulfonic acid salt compound in which R is an alkylaryl group. In particular, when R is an alkyl group or an alkylaryl group, it preferably has 5 to 40 carbon atoms, particularly preferably 8 to 30 carbon atoms. M is an alkali metal such as Na, K, Li or Mg;
Examples include alkaline earth metals such as Ca. Among them, Na,
K and Li are preferred.

Specific examples of such sulfonic acid metal salt compounds include sodium hexyl sulfonate, sodium heptyl sulfonate, sodium octyl sulfonate, sodium nonyl sulfonate, sodium decyl sulfonate,
Sodium dodecyl sulfonate, sodium octadecyl sulfonate, potassium decyl sulfonate, potassium dodecyl sulfonate, lithium octadecyl sulfonate,
Sodium dodecylbenzenesulfonate, sodium stearylbenzenesulfonate, sodium octylbenzenesulfonate, potassium dodecylbenzenesulfonate, lithium dodecylbenzenesulfonate, sodium octylnaphthalenesulfonate, sodium dodecylnaphthalenesulfonate, potassium dodecylnaphthalenesulfonate, etc. be able to. Of these, sodium dodecylbenzenesulfonate and lithium dodecylbenzenesulfonate are preferred.

The sulfonic acid metal salt compound represented by R-SO ₃ Mm of the present invention needs to be adjusted to pH 7.5 to 13.0 using a pH adjuster, and must be added to the reaction system at an arbitrary stage of the polyester production process. Is pH 8.0-12.5, more preferably pH 8.5-1
The pH is particularly preferably adjusted to pH 9.0 to 11.5 and then added.

If the pH adjustment of the sulfonic acid metal salt compound added to the polyester reaction system is less than 7.5, the compatibility of the polyester as an antistatic agent is not sufficient, and the surface defects and transparency of the obtained molded product can be improved. And the effect of improving the antistatic property does not appear. On the other hand, if the pH exceeds 13.0, the polycondensation reactivity of the polyester is reduced, or the obtained polyester is colored, and furthermore, the surface of the molded product obtained due to poor compatibility of the antistatic agent is roughened,
The molded product will be colored and impair the commercial value.

The pH adjusters of the present invention are selected from quaternary ammonium compounds and hydroxides or acetates of alkali metals or alkaline earth metals. Examples of the quaternary ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetraoctylammonium hydroxide and the like.

PH adjusting agents of the present invention is to adjust for example the sulfonic acid metal salt compound represented by R-SO ₃ M _m, the pH by adding water and / or glycol solution from 7.5 to 13.0,
The mixing ratio of these components is preferably such that the sulfonic acid metal salt compound is added to water and / or glycol in an amount of 0.1.
5 to 80% by weight, more preferably 1 to 70% by weight, more preferably 5 to 50% by weight, and the amount of the pH adjuster is 0.005 to 30% by weight, more preferably 0.05 to 25% by weight, based on the metal sulfonic acid compound.
%, More preferably 0.1 to 20% by weight.

Further, the heating of the water and / or glycol solution of the sulfonic acid metal salt compound represented by R-SO ₃ Mm to which the pH adjuster has been added is not particularly limited. When added to the polyester reaction system after heating for 5 minutes or more, excellent antistatic performance is obtained, compatibility with the polyester is significantly improved, and the surface state and transparency of the obtained molded product are extremely good.

The addition amount of the pH-adjusted sulfonic acid metal salt compound of the present invention is suitably in the range of 0.01 to 20.0 parts by weight, preferably 0.05 to 15 parts by weight, more preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the polyester. 10 parts by weight. If the amount is less than 0.01 part by weight, the antistatic effect is not sufficient, and if the amount exceeds 20.0 parts by weight, the mechanical properties deteriorate, which is not preferable.

The method and timing for adding the sulfonic acid metal salt compound of the present invention to the polyester are arbitrary and are not particularly limited. The addition may be performed before or during the ester exchange reaction or esterification reaction, or after the reaction, before or during the polycondensation reaction, or after the completion of the polycondensation reaction. It is preferably added at any stage from the transesterification reaction or esterification reaction to the end of the polycondensation reaction in the polyester production process, and more preferably from the end of the transesterification reaction or the esterification reaction to before the polycondensation reaction. The method of adding at an arbitrary stage is good.

Further, in order to further improve the transparency and antistatic property of the present invention, polyoxyalkylene glycol and the like can also be preferably used, and as the polyoxyalkylene glycol, polyethylene glycol having a molecular weight of 300 or more, polypropylene glycol, and polytetraalkylene glycol can be used. Methylene glycol and the like can be mentioned. Such a polyoxyalkylene glycol may have one end or both ends blocked by an organic group having an ester-forming functional group such as an ester bond or a carbonate bond. The preferred molecular weight of the polyoxyalkylene glycol is 300 to 50000
And more preferably 400 to 20,000. Particularly preferred polyoxyalkylene glycols have a molecular weight of 60
0-10000 polyethylene glycol. The amount of these polyoxyalkylene glycols added is polyester
With respect to 100 parts by weight, the range of 0.1 to 20.0 parts by weight is appropriate, preferably 0.2 to 10.0 parts by weight, more preferably 0.5 to 10.0 parts by weight.
8 parts by weight. If the amount is less than 0.1 part by weight, the antistatic effect is not sufficient when added to the polyester, and if added in excess of 20.0 parts by weight, the mechanical properties and heat resistance are undesirably reduced.

The method and timing of adding these polyoxyalkylene glycols to the polyester are arbitrary and are not particularly limited.

When producing polyester by the production method of the present invention, if necessary, a flame retardant, a heat stabilizer, an ultraviolet absorber,
Organic lubricants such as pigments, dyes, fatty acid esters and waxes or antifoaming agents such as polysiloxanes may be added. Furthermore, the purpose of imparting gloss, matting, crystallinity, slipperiness, etc. of molded products. With clay, mica, titanium oxide, calcium carbonate, kaolin, dry and wet silica, as well as colloidal silica, calcium phosphate,
Inorganic particles such as barium sulfate and alumina, as well as particles made of an organic compound containing silicon, acryl, styrene and the like as constituents may be added.

From the polyester obtained by the production method of the present invention, fibers, films, sheets and other molded products can be produced according to a conventional method.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.

 The characteristics in the examples were measured as follows.

A. pH of metal sulfonic acid compound The water and / or glycol solution containing the metal sulfonic acid compound and / or the pH adjuster is diluted with ion-exchanged water so that the metal sulfonic acid compound becomes 3% by weight. The pH indicated by the diluent is the pH of the metal sulfonic acid compound.

B. Compatibility of antistatic agent with polyester 20 mg of the polymer sandwiched between cover glasses was melt-press cooled on a 290 ° C. hot plate and then determined by microscopic observation.

 粗 No coarse substance of 5 μ or more was observed.

 粗 Coarse objects of 5μ or more are slightly observed.

 Many large objects of × 10 μ or more are observed.

C. Antistatic properties of polyester Using a Kawaguchi Electric MMA II-15 ultra-micro ammeter, leave a film obtained from polyester containing an antistatic agent at room temperature of 20 ° C and humidity of 65% for 1 hour. The surface resistivity of the film was measured.

D. Transparency of Polyester A film obtained from a polyester containing an antistatic agent was measured for film haze according to ASTM-D-1003-59.

Example 1 100 parts by weight of dimethyl terephthalate, 70 parts by weight of ethylene glycol, 0.09 parts by weight of calcium acetate as a transesterification catalyst, and 0.03 parts by weight of antimony trioxide as a polycondensation reaction catalyst were subjected to a transesterification reaction according to a conventional method. Add 0.05 parts by weight of trimethyl phosphate as a protective agent, and then add sodium dodecylbenzenesulfonate ethylene glycol solution (pH 30% by weight of sodium dodecylbenzenesulfonate) adjusted to pH 11.0 with tetraethylammonium hydroxide. Sodium was added so as to be 6 parts by weight.

Thereafter, a polycondensation reaction is performed according to a conventional method under high temperature and reduced pressure,
Using o-chlorophenol solvent, polyethylene terephthalate containing sodium dodecylbenzenesulfonate having an intrinsic viscosity of 0.645 measured at 25 ° C was obtained. The color tone and transparency of the obtained polymer were good, and when the compatibility of the antistatic agent with the polyester was observed, it was finely dispersed.

The obtained polymer and polyethylene terephthalate not containing sodium dodecylbenzenesulfonate are blended so that sodium dodecylbenzenesulfonate becomes 1 part by weight with respect to 100 parts by weight of polyester, further dried, and dried at 290 to 300 ° C. with a film forming machine. After stretching with a biaxial stretching machine, the film was stretched at a longitudinal stretching ratio of 3.2 times and a transverse stretching ratio of 3.2 times, and then heat-treated at 220 ° C. to obtain a 50 μm thick film. The surface resistivity of the film was 5.9 × 10 ⁹ Ω, and the film haze was 0.7%, which was excellent in both antistatic properties and transparency.

Comparative Example 1 In the same manner as in Example 1, a sodium ethylene glycol solution of dodecylbenzenesulfonate having a pH of 7.0 and containing no pH adjuster was added to obtain a polyester and a film.

Observation of the compatibility of the antistatic agent with the polyester revealed a dispersion state of 30 to 40 μm.

The surface resistivity of the film was 10.3 × 10 ⁹ Ω and the film haze was 5.8%, which was poor in both antistatic properties and transparency.

Examples 2 to 5, Comparative Example 2 As described in Table 1, various methods were used in the same manner as in Example 1.
A sulfonic acid metal salt compound whose pH was adjusted using a pH adjuster was added to obtain a polyester and a film.

 Table 1 shows the results.

Examples 2 to 5 were within the scope of the present invention, and the color tone of the polyester, the compatibility of the antistatic agent with the polyester, the surface resistivity of the film, and the film haze were good.

On the other hand, in Comparative Example 2, the pH of the sulfonic acid metal salt compound was out of the range of the present invention, and the obtained polyester had a strong yellow tint, and the compatibility of the antistatic agent with the polyester was observed. Was observed. Also, the transparency of the obtained film was poor.

Examples 6 to 10 As described in Table 2, a polyester was obtained in the same manner as in Example 1 except that the amount of the sulfonic acid metal salt compound whose pH was adjusted using a pH adjuster was changed.

Further, polyesters to which various polyoxyalkylene glycols were added after the addition of the sulfonic acid metal salt compound were produced. The obtained polyester was used alone in Example 1.
A film was produced in the same manner as described above.

 Table 2 shows the properties of various polyesters and films.

Both examples are within the scope of the present invention and the color tone of the polyester, the compatibility of the antistatic agent with the polyester,
Both the surface resistivity and the film haze of the film were good.

[Effects of the Invention] As described above, the present invention provides a specific pH using a pH adjuster.
By adding the sulfonic acid metal salt compound adjusted as described above at an arbitrary stage of the polyester production process, a polyester which has not been obtained conventionally and has good compatibility with the polyester and excellent transparency can be obtained.

From the polyester obtained by the production method of the present invention, there is no surface defect, transparency, good fiber of antistatic agent,
Films, sheets and other molded products are obtained.

Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08K5 / 42 C08K5 / 42 (56) References JP-A-62-161823 (JP, A) JP-A-63-308059 (JP, A) JP-A-55-50082 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 63/00-63/91 C08L 67/00-67/08

Claims (1)

(57) [Claims] A polyester selected from the group consisting of a quaternary ammonium compound and a hydroxide or acetate of a quaternary ammonium compound and an alkali metal or an alkaline earth metal in producing a polyester by reacting a dicarboxylic acid or an ester-forming derivative thereof with a glycol. A method for producing a polyester having antistatic properties, comprising adding a metal sulfonic acid compound, whose pH has been adjusted to 7.5 to 13.0 using a regulator, to a reaction system at any stage of the polyester production process.