JPS5871922A - Manufacture of highly-transparent antistatic polyester - Google Patents

Abstract

PURPOSE:To obtain titled polyester of excellent color tone by adding, to a bis- diol ester comprising terephthalic acid, etc., a phosphorus compound followed by each specific compound and polymer to carry out polycondensation. CONSTITUTION:The objective polyester can be obtained by adding, to (A) a bis- diol ester and/or its oligomer prepared by the reaction between (i) terephthalic acid (or its lower ester) and (ii) ethylene glycol, (B) a phosphorus compound (e.g., trimethyl phosphate) in such an amount as to be 20-150ppm, calculated as the amount of phosphorus, based on the resultant polyester followed by (C) sodium dodecylbenzenesulfonate with an AV-value of 0.01-0.5mg KOH/g and (D) polyethylene glycol with a molecular weight of 600-8,000 in such amounts as to be each 0.1-15wt% on the basis of the resultant polyester and then by carrying out polycondensation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyester suitable for obtaining an antistatic polyester film having excellent transparency and color tone.

As is well known, polyester, especially polyethylene terephthalate, is stretched biaxially by 3 times or more and then heat treated, resulting in a film that has a high degree of crystallinity, excellent transparency, mechanical properties, chemical resistance, and heat resistance. It is being used in a wide range of fields, including packaging for foods, pharmaceuticals, and industrial parts, as well as protective coatings, transfer films, release films, vapor deposition applications, and projector film applications.

Existing polyester films used in these fields have the disadvantage that because the polymer itself has a high degree of electrical insulation, it is extremely easily charged, and the generation and accumulation of static electricity causes various problems. In particular, under low humidity conditions, static electricity is generated to a large extent, which is a major cause of decreased workability and product value. Furthermore, in applications such as projector films and packaging films, in addition to antistatic properties, the transparency of the film itself determines its commercial value, so it is necessary to have good transparency.

Conventionally, sulfonazaki salt derivatives and polyalkylene glycols have been used for the purpose of imparting antistatic properties to polyesters. 47072
No. 52-134662, Japanese Patent Application Laid-Open No. 1982-134662
-151365, etc. Special Public Service Showa 44-61s2
s-t; (Publication V) describes an example in which a high molecular weight polyalkylene glycol that is substantially insoluble in polyester is used, but the polyester obtained in this case becomes cloudy and has poor transparency. Bad and undesirable. Again.

JP-A-52-47069, JP-A-52-4707
Publication No. 2 contains sulfonate derivatives and molecular weights of 400 to 80.
A film with a composition of polyalkylene glycol No. 00 is exemplified. In this case, although it is possible to impart a certain degree of electrical conductivity, it has the disadvantage that the transparency of the film is poor. In addition, in JP-A-52-134/)62, only sulfonate derivatives are used as polyesters.
An example is described in which an antistatic property of 1 IE can be obtained by performing heat treatment at a heating temperature of i+oo to 25Q°C. However, this method also does not provide any improvement in terms of transparency. The present inventors have studied ways to improve the drawbacks of the conventional polyester films described above, namely, the inability to obtain a film that satisfies transparency, antistatic properties, and color tone, and has arrived at the present invention.

That is, the present invention is directed to a bisdiol ester and/or a low polymer thereof obtained by the reaction of terephthalic acid, a lower alkyl ester thereof, and ethylene glycol. '50 ppm (relative to polyester) of phosphorus compound was added, then (2j A
V value 0.0 i ~ 05 mgKo)] / g of sodium dodecylbenzenesulfonate 0.1 ~ 15 weight ratio (relative to polyester) ε and polyester weight range glycol 0.1 ~ 15 weight ratio (relative to polyester) with molecular weight 600 ~ 8000 Transparency e characterized by adding polyester) and performing polycondensation
This is a method for producing an excellent antistatic polyester.

The bisdiol esters and/or low polymers thereof obtained by the reaction of terephthalic acid or its lower alkyl ester with ethylene glycol in the present invention are esters of terephthalic acid, dimethyl terephthalate, diethyl terephthalate, etc., and ethylene glycol. The reaction method and the degree of polymerization after transesterification are in the range of 1 to 5.

Phosphorus compounds in the present invention e are phosphorus beak, sulfurous acid, mono-, di- or tri-esters of phosphoric acid (methyl anotphosphate, ethyl acid phosphate, trimethyl phosphate, [・liphenyl phosphate)]
, or phosphonic acid, phospho4-1- (phenylphosphonic acid.

Examples include compounds such as dimethylphenylphosphonate-1, etc.). The amount added is 20 to 20% as the amount of phosphorus.
150ppm is required, preferably 550-1O0p
It is p. When the amount is less than 20 ppm, the heat resistance of the polymer deteriorates and the polymer tends to be colored during polymerization or melt molding. If it exceeds 150 ppm, the transparency of the film will be impaired and the polycondensation rate will decrease, making it difficult to obtain a polyester with a high degree of polymerization.

The AV value of sodium dodecylbenzenesulfonate used in the present invention is 0.01-0.5 mg KOII/g, preferably 0.02-0.2 mg KOH/g. If the AV value is less than 0.01 mgKOH/g, coarse particles will occur in the polymer and the film will become transparent.
Life is damaged. However, if it exceeds 0.5 mgKOH/g, the polymer color tone becomes strong yellowish, making it impractical, and disadvantages such as generation of coarse particles and deterioration of transparency occur. The AV value here refers to the acid component t in sodium dodecylbenzenesulfonate, and the dodecylbenzenesulfone Hj when neutralized and titrated with potassium hydroxide.
gAC cost 'C' is the amount of potassium hydroxide, mgKOH/
It is expressed as g. However, the amount added is still 0.1 to 1
5% by weight is required, preferably 0.5 to 10% by weight. If the weight width is less than 0.1 weight, good antistatic properties cannot be obtained, and if the weight width exceeds 15 weight, disadvantages such as the slimy feeling of the polyester molded product and deterioration of transparency will occur. Not.

The polyethylene glycol used in the present invention has a molecular weight of 600 to 8,000, and the amount added is 0.1 to 15% by weight, preferably 0.5 to 10% by weight.

Here, the polyethylene glycol of the present invention includes those copolymerized with other alkylene glycol units at a circulation of 40 moles or less. The molecular weight of polyethylene glycol is 6
If the polyester is not vortexed at 0.00, the softening point of the obtained polyester is significantly lowered, the dimensional stability is deteriorated, and the antistatic property k), which is one of the objects of the present invention, is not exhibited. Moreover, if it exceeds 8,000, the polyethylene glycol component becomes insolubilized with the polyester, which is not preferable because the polymer itself becomes white and the film becomes dry. If the amount of polyethylene glycol added is less than 0.1% by weight, the antistatic properties will not be sufficient, and if it exceeds 15% by weight, the heat resistance of the polymer will deteriorate and the color will be too yellowish to be of practical use.

Both sodium dodecylbenzenesulfonate and polyethylene glycol in the present invention are essential components for the purpose of the present invention, and if only 10,000 yen is used, the film cannot have both antistatic properties and transparency.

The order of addition of the phosphorus compound, sodium dodecylbenzenesulfonate and polyethylene glycol used in the present invention is esterification.

It is necessary to add a phosphorus compound between the end of the transesterification reaction and the beginning of the polycondensation reaction, and then add sodium dodecylbenzenesulfonate and polyethylene glycol. If a phosphorus compound is added after sodium benzene sulfonate and polyethylene glycol, coarse particles will be generated in the polymer, impairing the transparency of the resulting film and making it impossible to achieve the transparency that is the objective of the present invention. Ginai. The polyester composition obtained in the present invention can also be used as a master chip by blending it with ordinary polyester.

In this case, the respective contents of sodium dodecylbenzenesulfonate and polyethylene glycol in the film are preferably 0.5 to 3% by weight.

The polyester obtained by the present invention is not only suitable for producing polyester films, but also
When this polyester is used for various edges or molding, it has excellent transparency and antistatic properties! #Vibration or molded products! ! ! ! ! It is possible to build In carrying out the present invention, antioxidants such as findart phenol compounds, polysiloxanes, pigments, dyes, inert inorganic particles, etc. are used within the range that does not impair the purpose of the present invention. You may.

The present invention will be explained in more detail with reference to Examples below.

16. Description of Examples tMeasurement Method of Priority t'l Valuee
Let me explain in detail.

(1) Measurement of a 0.21 m thick sample that had been left for 1 hour at a room temperature of 20° C. and a humidity of 65 using an MMA ■-15 type ultra-micro ammeter manufactured by Denki Seisakusho for surface resistivity.

(2+-・Is ASTM-D-1003-59T? According to this, thickness 02
Discipline ±0. The measurement was carried out on a sheet e of Oi 1m.

(3) Method for Measuring Coarse Particles in Polymer 20 mg of the polymer sandwiched between cover glasses e was melted on a hot plate at 290°C, then rapidly cooled in water, and the coarse particles in the polymer were observed using a polarizing microscope.

(4) Limit #I The intrinsic viscosity of the modified polymer was measured at 25° C. using O-chlorophenol solvent.

Example 1 (Experimental Plane 1) 100 parts by weight of dimethyl terephthalate, 65 parts by weight of ethylene glycol, 0.09 parts by weight of calcium acetate as a transesterification reaction catalyst, and 0.06 parts by weight of antimony trioxide as a polymerization catalyst were added, and 140 to 220 After distilling off an almost theoretical amount of methanol at a temperature between 1 weight percent polyester glycol of molecular weight Q40DO was added.

Next, the pressure in the system was gradually reduced, and the mixture was heated to 290° C. under a reduced pressure of 117 NHg to distill off ethylene dalycol, and the reaction was completed in 4 hours. The resulting polyethylene terephthalate has an intrinsic viscosity of 0.637° and a softening point of 257.0°C.
Met. This polymer was made into chips, dried, formed into a film at 290 to 500°C with a film forming machine, stretched with a biaxial stretching machine at a longitudinal stretch ratio of 32 times and a transverse stretch ratio of 6.5 times, and then at 200°C. A film with a thickness of 100 μm was obtained by heat treatment. The film has a surface resistivity of 5.6×10 9 Ω, a film haze of 1.8, and excellent antistatic properties and transparency.

Examples (Experiments A2 to 15) Addition amount and addition of phosphorus compound in Example 1+111.
Example 1 was carried out in exactly the same manner as in Example 1, except that the AV value and addition amount of sodium dodecylbenzenesulfonate and the molecular weight and addition amount of polyethylene glycol were changed. The properties of the obtained film are shown in Table 1e. Comparing these results with Example 1, it was found that Experimenter 3 changed the AV value of IJium within the scope of the present invention, or changed the added amounts of sodium dodecylbenzenesulfonate and polyethylene glycol according to the present invention. All of the experimental plates increased within the range of 9.10 had good antistatic properties and transparency. However, if the A and V values of sodium dodecylbenzenesulfonate and the amount of phosphorus compound added are outside the range of the present invention (Experimental Standard 2.4
, 6.7), it can be seen that coarse particles or color tone deterioration occurs in the polymer, resulting in poor transparency. Similarly, if the order of addition of the phosphorus compound is changed, coarse particles are generated in the polymer, resulting in poor transparency (Jikkenya 5.i4, 15).

Furthermore, if polyethylene glycol having a molecular weight outside the range of the present invention is used, the antistatic properties will be poor at low molecular weights (Experiment A 12), and the transparency will be poor at high molecular weights (Experiment A 12).
Experimental test 13). In addition, when increasing or decreasing the amount of dodecylbenzenesulfonate and polyethylene glycol added, antistatic properties were not developed when they were not added (Experiment 8).
If the range of the present invention is exceeded, the color tone in the polymer deteriorates and the transparency is poor (Experimental Plane 11), resulting in poor antistatic properties and poor transparency.

Example (Experiment/1h16, 17) The added amounts of sodium dodecylbenzenesulfonate and polyethylene glycol were decreased, and further (these polymers were added as the respective contents of sodium dodecylbenzenesulfonate and polyethylene glycol in the film). The process was carried out in exactly the same manner as in Example 1, except that it was blended with ordinary polyethylene terephthalate having an ultimate viscosity of 0.65 to give a weight percent.Table 1 shows the properties of the obtained film.
I'll show you one thing. Comparing these results with Example 1, it is found that if the addition order of the phosphorus compound and the addition amounts of sulfur and lithium dodecylbenzenesulfonate and HoIJ ethylene glycol are carried out within the scope of the present invention, antistatic properties can be obtained even if the master chip is made. It is also excellent in transparency (Experiment A1117).

Claims (1)

[Claims] If terephthalic acid or its lower alkyl ester is mixed with ethylene glycol, the obtained bisdiol ester and/or its low polymer e are added (1) a phosphorus compound with a phosphorus content of 20 to 15 oppm (based on the polyester); Then (2) AVVO20i -0,5
mgKOH/g sodium dodecylbenzenesulfonate 01-15 weight q6 (U polyester) 2 polyethylene glycol with molecular weight 600-8000 01-15
A method for producing an antistatic polyester with excellent transparency, characterized by adding % by weight (based on polyester) and carrying out single polycondensation.