KR930003713B1 - Produce for preparation of polyester copolymer - Google Patents

Abstract

The polyester having good color tone and transparency is prepared by: adding ammonium cpd (A) as catalyst of esterification; adding 2.5 wt.% of glycol soluble antimon cpd (B) and tin cpd. (C) as polymerizing catalyst at above 150 deg.C of the bath; and adding phosphoric cpd. (D) as stabilizer and cobalt cpd. (E) as a color tone improving agent in the polycondensation reaction process, together with phosphoric cpd. of formula (I) contg. amine bond to be introduced into bisglycol reacting tube; and where the amt. of the catalyst and stabilizer is satisfied of formula (II),(III),(IV) and V. In formulas, R1,R2,R3,R4 and H or C1-10 alkyl; R5 is C1-10 alkylene or benzene ring; B,C,D,E are PPM amt. of Sb cpd., Sn cpd..

Description

Manufacturing method of polyester copolymer having good color tone and transparency

The present invention relates to a method for producing a polyester copolymer having a good color tone and excellent transparency. Particularly, in the polycondensation of low molecular weight polyethylene terephthalate by reacting ethylene glycol and terephthalic acid, Slurry, add ammonium compound to ester reaction, use small amount of glycol soluble antimony compound and tin compound as polymerization catalyst in polycondensation reaction, phosphorus compound with amine bond as stabilizer It is related with the manufacturing method of the polyester copolymer with favorable transparency used as an improving agent.

In general, polyesters have excellent mechanical and chemical properties, and thus they have various uses, such as for blow moldings for films, as well as for clothes, sheets, fishing nets, tents and tire cords.

In particular, thermoplastic polyesters made on the basis of ethylene glycol terephthalate units have been used as materials for cosmetics, medicines, and food packaging in the form of films, sheets, and containers. In the past, containers commonly used in cosmetics, medicine, and food packaging were made of glass, PVC, PP, and PC resin. However, these containers have not been satisfactory due to price, biological degradation or other reasons.

Containers such as glass, for example, have a distinct disadvantage, are easily broken, difficult to transport and heavy, and have high energy consumption during manufacturing. Among the materials available for containers used in cosmetics, medicines and food packaging is pulley ethylene terephthalate (PET). However, due to the fluid nature of PET, the manufacture of bottles and containers requires special equipment and associated costs. The equipment is based on the process of injection molding cylindrical or tubular preforms and reheated in a twin-axial drawing blow molding machine to form containers or bottles. Withdrawal of the amorphous state and it under the biaxial stretching conditions, polyethylene glycol terephthalate has excellent transparency and at the same time shows the advantage of stretched crystal phase that significantly improves its mechanical properties and reduces gas permeability.

Modified PET for use in the injection molding process is described in US Pat. Nos. 3,673,139 and 3,692,744.

These patents relate to the combination or independent introduction of crosslinkers and crystallization inhibitors to PET to give injection moldable compositions. Although the drawbacks of such injection molding processes have already been pointed out, the latter part of the patent proposes that the modified PET introduced with a crosslinking agent and a crystallization inhibitor is suitable for extrusion molding. It is therefore described as being particularly suitable for the manufacture of intermediate products such as rods, sheets, hollow sheets.

In this process, there is no mention of the process of extruding preforms for making hollow molded parts such as containers and bottles, which is a cosmetic, pharmaceutical and food container using commercially available extrusion molding equipment in US Patent No. 894,674. It is possible by a method for producing a PET bottle and a molding container suitable for the.

Attempts have been made to introduce various modified polyesters, including PET and crosslinkers or end group blockers, or both, in areas other than extrusion of containers and bottles in the process.

These attempts involve the manufacture of polyesters suitable for use in electrical and thermal insulators, coating compositions, or fiber and filament preparations with increased dyeing properties, such as US Pat. Etc. are proposed.

In addition, U.S. Patent No.894,674 has a combination of crosslinking agent and end group blocker, in which modified PET has high melt strength and gel-free characteristics and is suitable for use in commercial extrusion blow molding. It is proposed to be produced by selecting and introducing, but this modified PET has a partially opaque portion when extrusion blow molding in a general technique, the patent when extruded blow molding the modified PET when manufacturing a container or a bottle The disadvantage is that the thick neck of the bottle becomes opaque. In a variety of applications in the cosmetics, pharmaceuticals and food industries, this aesthetic need is especially emphasized, so that there should be no opacity at all.

In order to improve these problems, U.S. Patent No. 4,234,708 describes a high viscosity polyethylene isophthalate characterized by the introduction of a combination of crosslinking agent and end group blockade agent and completely transparent to extrusion hollow molding according to the general technique. For the preparation of terephthalate copolymers.

However, these modified polyesters have the drawback that they contain very poor yellow in hue, which is a very important consideration in the manufacture of bottles and containers.

The purpose of this patent is to overcome the problems listed above, and in particular to the introduction of stabilizers to enhance color tone and transparency in the production of modified PET using crystallization inhibitors. Transparency and glossiness can be affected due to the formation of crystalline spheres, especially in containers of relatively thick thickness.

In preparing bottles by injection molding or extrusion-blow molding, the molten state is first quenched to obtain a thick preform, where the crystallographic spheronization in the preforming step affects the transparency of the final product.

It is therefore advantageous to use polyesters with slow crystallization rates. Copolymerizable regulators for inhibiting crystallization include aromatic and / or aliphatic polybasic carboxylic acids and / or polyhydric alcohols. For example, it is possible to use isophthalic acid, naphthalenecarboxylic acid, adipic acid and sebacic acid or their functional derivatives capable of forming polyester.

Examples of diols include neopentyl glycol, hexane-1,6-diol, bis-1,4-hydroxymethylcyclohexanediethylene glycol, triethylene glycol and the like.

That is, the ester reaction which forms the bisglycol ester of terephthalic acid or its oligomer by heating reaction of tetephthalic acid or its lower alkyl ester derivative, and ethylene glycol, and the bisglycol ester or terpolymer of the terephthalic acid which were produced are polycondensation reaction tanks. Condensation polymerization of a carboxylic acid selected from isophthalic acid or its functional derivative or an aromatic and / or aliphatic polybasic carboxylic acid which is a copolymerization regulator for inhibiting crystallization in a solid state or by adding a slurry with ethylene glycol in a conventional manner Excess is known. Isophthalic acid or its functional derivative is substituted for terephthalic acid or its functional derivative dimethyl terephthalate moiety used to make low molecular weight polyethylene terephthalate. It is about 5-20% by weight based on the amount of terephthalic acid or dimethyl terephthalate required to make. Therefore, the weight ratio of terephthalic acid unit and isophthalic acid unit is 80: 20-95: 5 in the polyethylene isophthalate terephthalate copolymer.

The amount of isophthalic acid structural unit defined in the present invention lowers the melting point (Tm) of the polymer as compared to the general polyethylene terephthalate as described above.

This allows the solid-state polymerization to be carried out at lower temperatures, ie, as low as 190 ° C-210 ° C compared to normal 220 ° C. Furthermore, the crystallization rate and crystallization temperature are also lowered, making it easier to perform quenching operations that eliminate opacity in the thick parts of the molded part during extrusion operations.

However, excessive use of isophthalic acid or dimethyl isophthalate as starting material for the copolymer should be avoided because of the overall formation of amorphous polymers. Such polymers have a particularly low secondary transition temperature (Tg) and tend to stick to each other during solid phase polymerization at normal solid phase polymerization temperatures. Solid phase polymerization in this case should be carried out at temperatures below the melting point of 140 ° C-180 ° C.

At such low temperatures the time at which the polymerization takes place is actually very long.

Catalysts and stabilizers are commonly used in ester reactions and condensation polymerization reactions. For example, sodium, lithium, calcium, magnesium, manganese, zinc, tin, etc. are used in ester reactions, and as polymerization catalysts, for example, Antimony compounds, germanium compounds and titanium compounds are used.

Antimony compounds in the polymerization catalysts are cheap and have excellent catalytic activity, but they must have a large amount of catalyst, and antimony metal precipitates during the reaction to blacken the polymer. Germanium catalysts can obtain polymers having excellent reactivity and excellent transparency and gloss. On the other hand, the solubility in the reactant is insoluble or remains insoluble, it is difficult to increase the degree of polymerization flew out of the reactant by the sublimation during the reaction, reducing the heat resistance when used in excess, the titanium compound has the disadvantage that the reactant is colored.

Therefore, it is very difficult to obtain a polyester having excellent transparency and good color tone with such a conventional catalyst addition technique and manufacturing cost. Films and blow moldings require the transparency and gloss of polyester. In general, antimony compounds, which have been widely used industrially, have been used because germanium catalysts have been used due to the disadvantage of blackening. Command Offices 44-42,756, Japan Command Offices 47-48,517, Japan Command Offices 48-44,197, Japan Command Offices 49-43,396, Japan Command Offices 55-40,704, Japan Command Offices 52-49,292)

However, because germanium catalysts are very expensive, they have to be reduced in order to use them industrially to obtain price competitiveness. Japanese special forces 47-39,239, Japanese special forces 48-26,955, Japanese special forces 49-09,116, Japan Japanese military offices 49-25, 193 and US Patent No. 3,795, 639 used germanium and antimony compounds in parallel. Japanese military offices 49-13, 635 used germanium and lead compounds, and Japanese military office 53-06, 175 used germanium and titanium compounds. 48-37,759 uses germanium and magnesium compounds and US Pat. No. 3,842,043 uses germanium and calcium compounds to maintain transparency and reduce manufacturing costs.

In addition, the transparency of the germanium is 49-35,461, and the Japan-specific 49-33,998 is used to improve the transparency without using germanium at all. Antimony compound was used alone as a silver polymerization catalyst. However, tetraethylene glycol was added to the polycondensation reaction to reduce crystallization to improve transparency. However, it has the disadvantage of reducing the mechanical strength of the final molded foam. 134,786 used an antimony compound and cobalt compound was added as a color tone improver, but bromine compound was used in parallel.

US Pat. No. 4,082,724 is characterized by using an antimony compound alone and adding a large amount of phosphorus compound. In order to produce a polyester copolymer having a glassy transparency and good color tone, the present invention uses terephthalic acid and ethylene glycol as the main raw materials, and copolymerization regulators for inhibiting crystallization, in particular isophthalic acid or its action, as mentioned above during the polycondensation reaction. In the preparation of polyethylene isophthalate terephthalate copolymer in the form of a solid derivative or slurry with ethylene glycol, an ammonium compound (A) is used as an inhibitor of decomposition reaction during ester reaction, and a glycol soluble compound (B) is used as a polymerization catalyst. ) And a tin compound (C), and as a stabilizer, a phosphorus compound (D) having an amine bond represented by the general formula (I) and a cobalt compound (E), which is a color tone improving agent, are added. It is a polyester copolymer manufacturing method which satisfy | fills (III) (IV) (V).

80 <A <400. … … … … … … … … … … … … … … … … … … … … … … … (II)

210 <B + C + E <300 (B> 1000). … … … … … … … … … … … … … (III)

1 &lt; C / E &lt; 1.5. … … … … … … … … … … … … … … … … … … … … … … … (V)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ is a high atom or an alkyl or aryl group having 1-10 carbon atoms, R ₅ is an alkylene group or benzene group having 1-10 carbon atoms, B, C, D, E Indicates the content (PPM) of each compound in the polymer.)

A characteristic of the polyester copolymer production method of the present invention is that the ammonium compound is used for the ester reaction, and when the glycol-soluble antimony compound and the tin compound are co-used as a polymerization catalyst, a small amount is added and phosphorus having a cobalt compound and an amine bond is used. A compound is used to obtain a polyester copolymer having excellent transparency and good color tone.

Stabilizers used in the present invention are phosphoryldimethylethanolamine, 2-dimethylaminophenoldiphenylphosphate, 2-diethylaminoethanoldimethylphosphate, 2-ethylpropylaminophenoldihydrogenphosphate, 2-dibutylaminophenoldihydride Rosenphosphates can be used.

The amount of phosphorus compound (D) having an amine bond is determined by the tin compound and cobalt compound as shown in formula (IV). If the amount is less than 0.3 in formula (IV), transparency decreases and the reactivity deteriorates. The polymer is yellow in color.

The cobalt compound prevents the polymer from becoming yellow due to the tin compound, but the transparency deteriorates as the amount of the tin compound increases. Therefore, when the ratio of the tin compound is less than or equal to 1, the transparency deteriorates. It is worn.

Patents that use antimony compounds and tin compounds for polyester production are generally put into ester reactions to shorten the reaction of polyesters (Japanese Patent Application No. 55-5530). In fact, cobalt compounds are added in large amounts.

Cobalt acetate is suitable as the cobalt compound used in the present invention. In addition, Japanese Patent Application No. 55-5535 did not add tin compounds to the polycondensation reaction as the main material was diethyl terephthalic acid. It is difficult for the compound to completely dissolve in glycol and dissolve because the tin compound remains sediment even when the temperature is less than 150 ° C, so it is not evenly distributed in the reactants.

In the present invention, the use of an ammonium compound increases the effect of preventing softening point and is characterized in that it is added during the ester reaction. As the ammonium compound used in the present invention, tetraethyl ammonium hydroxide is used, and the amount is 50-400 PPM in the ester reaction, which is added at room temperature. At this time, when the amount is less than 50PPM, the softening point is not prevented. Will slow down.

In the present invention, when the glycol soluble antimony compound and the tin compound are used as a catalyst in the pre-dissolution in glycol, the concentration of the catalyst is diluted to 2.5% and 1.0% or less, respectively, and the temperature of the input tank is maintained at 150 ° C. or higher, thereby the catalyst in the reaction product. It can be seen that the compounds of can be evenly distributed. Antimony compounds used in the present invention include antimony acetate, antimony tritlylide, antimony trichloride, antimony trifluoride, antimony trioxide, and the like, and tin compounds include monobutyl tin oxide, dibutyl tin oxide, and the like.

Catalyst usage is around 100-250PPM. When the catalyst is less than 100PPM, it is difficult to increase the degree of polymerization, and an excessive amount of cobalt compound is required to compensate for the poor color tone, but the excess cobalt compound inhibits transparency. Deterioration of transparency and color tone is worsened, such as the injection of antimony antimony alone, exceeding 250PPM. To solve this problem, the transparency of the final molded product is rapidly deteriorated, and the polymer reaction time is long. The ratio of antimony compound and tin compound should be controlled to be 0.26-1.0. If less than 0.26, the polymer is colored by precipitation of metal antimony. If it is greater than 1, the polymer is yellow and the polymerization rate is slow.

In carrying out the method of the present invention, the tin compound and the antimony compound should be added in a temperature range of 150 ° C. or higher, but the cobalt compound should be added to the same input bath after the antimony compound and the tin compound are dissolved. Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

Intrinsic viscosity in an Example is a value which was set as the Wevelrod viscometer at 25 degreeC using ortho chlorophenol as a solvent, and the polymer color tone was calculated | required the polyester chip which completed the polymerization reaction using the color difference meter at room temperature. The hue L value indicates lightness (the higher the value is good) and the b value indicates yellow and blue color (the lower the value, the better). In addition, the transparency of the polymer is expressed as a solution haze, and the method was dissolved at 120 ° C. in a phenol / tetrachloroethane (6/4, weight ratio) mixed solution and measured at room temperature with a haze meter (the better the later the value).

Example 1

Terephthalic acid and ethylene glycol were added at 142 kg and 80 kg, respectively, to 15 g of tetraethylammonium hydroxide in an ester reaction tube, and the reaction was performed for about 4 hours under a nitrogen atmosphere of 2 kg / cm 2. After the reaction was completed, the reaction product was transferred to a condensation polymerization tube, and at the same time, a small amount of a slurry of 24 kg of isophthalic acid and 13 kg of ethylene glycol was added in an equal amount. After completion of the addition, 28.6 g of phosphoryldimethyl ethanolamine, a thermal stabilizer, was added and stirred at atmospheric pressure for 5 minutes. At this time, the polymerization catalyst of the antimony compound and tin compound added was dissolved in 2.5% and 1% in a dissolution tank in advance. The amount of catalyst containing cobalt acetate compound was 28.6 g of antimony trioxide, 11.55 g of monobutyl tin oxide, and 9.7 g of cobalt acetate compound. The reaction proceeded continuously at this time. The reaction was completed at a temperature of 3 hours and 30 minutes to complete the condensation polymerization. The inherent viscosity of the obtained polymer was 0.65, the L value was 58.2, the b value was 0.2, and the haze was 0.41, which was very transparent at the time of melting.

Comparative Example 1

The ester reaction was completed by the same method as in Example 1, and a condensation polymerization reaction was carried out. At this time, 28.6 g of phosphoric acid, 28.6 g of antimony trioxide, 11.5 g of tin compound (monobutyl tin oxide), and 9.7 g of cobalt acetate were not dissolved and mixed with ethylene glycol to be simultaneously added.

The inherent viscosity of the produced polymer was 0.654, L value was 51.1, b value was 1.4, and haze was 1.6.

Example 2-4

The reaction was carried out in the same manner as in Example 1, and the loading of the catalyst was changed.

In the above table, when the antimony compound was increased, the L value decreased, and when the total amount of the antimony compound and tin compound decreased, the degree of polymerization of the haze and the polymer was slightly lowered. However, a small amount of phosphorus compound was added even though a small amount of antimony compound was added, which did not significantly affect the reaction time, and the yellow phenomenon was controlled by the input amount of cobalt compound to make it transparent. However, the chemical mechanism was still identified during the reaction. It could not, but it clearly showed an increase in transparency.

Comparative Example 2-3

Ethylene ammonium compound was not added in the esterification reaction or the polymerization method and the amount of the polymerization catalyst were changed as shown in the following table.

In the addition method, Comparative Example 2 was the same method as Example 1, Comparative Example 3 was added after dissolving the antimony compound at 175 ℃, the tin compound was added at room temperature.

The above table does not satisfy the formula (II) (III) (IV) (V) of the present invention, it can be seen that the color tone and transparency of the polymer is greatly changed according to the method of adding the polymerization catalyst. That is, when the amount of addition of the antimony compound and the tin compound as the polymerization catalyst increases, the transparency decreases, and when the tin compound as the polymerization catalyst is not dissolved without adding the ammonium compound, the transparency and color tone deteriorate as well.

Claims (1)

The weight ratio of terephthalic acid and isophthalic acid in terephthalic acid and ethylene glycol as the main raw materials, and the addition of the above-mentioned copolymerization regulators for inhibiting crystallization, especially isophthalic acid or ethylene glycol, in the polycondensation reaction, was added. Dissolution concentration when using ammonium compound (A) as ester reaction catalyst and glycol-soluble antimony compound (B) tin compound (C) as polymerization catalyst in preparing polyethylene isophthalate terephthalate copolymer frame Is 2.5% by weight or less than 1.0% by weight, and the temperature of the input tank is maintained at 150 ° C or higher, and the phosphorus compound (D) as a stabilizer and the cobalt compound (E) as a color tone improving agent are added to the condensation polymerization reaction. The process is performed by adding cobalt compounds to dissolved antimony and tin compounds together with phosphorus compounds with amine bonds of the general formula (I). The expression amount of the catalyst and stabilizer were charged into a reaction tube recall (Ⅱ) (Ⅲ) (Ⅳ) method for producing a color tone and a good transparency, a polyester copolymer which is characterized in that so as to satisfy the (Ⅴ).

80 <A <400. … … … … … … … … … … … … … … … … … … … … … … … (II) 210 〈B + C + E

300 (B

100)... … … … … … … … … … … … … … … (III)

1 <C / E

1.5... … … … … … … … … … … … … … … … … … … … … … … … (V) Wherein R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen atoms or alkyl groups having 1-10 carbon atoms, R ₅ is an alkylene group or benzene ring having 1-10 carbon atoms, and B, C, D, and E are each Displays the conversion amount (PPM) of antimony, tin, phosphorus and cobalt compounds in the polymer.)