KR101262833B1 - Flame-retardant polyester compostion - Google Patents

Abstract

The present invention relates to a flame retardant polyester composition comprising a polyester, a phosphorus flame retardant and an electrostatic pinning agent, and the present invention relates to a polyester composition which is not only heat stable but also has improved pinning.

Polyester, Flame Retardant, Pinning

Description

Flame retardant polyester composition {FLAME-RETARDANT POLYESTER COMPOSTION}

The present invention relates to a flame retardant polyester composition, a method for producing a flame retardant film using the same, and a flame retardant film prepared from the flame retardant polyester composition.

Polyester resins are excellent in mechanical strength, heat resistance, electrical insulation and chemical resistance, and are generally used in various fields such as yarn, film, and plastic molded articles. In addition, the polyester film currently produced industrially is widely used as a base film for magnetic recording media, various packaging materials, and other industrial uses, and recently, it is used as a graphics material and various post-processing materials.

Usually, a polyester film is obtained by melt-extruding a polyester resin and then biaxially stretching. More specifically, the polyester film is extruded at a high temperature of the polyester, and then cooled to produce an amorphous polyester sheet, which is then rolled in the same direction as the moving direction of the sheet using rolls arranged in the up-down direction or the transverse direction. Direction is stretched, and the stretched sheet is stretched again perpendicular to the traveling direction. The extrusion process at a high temperature may be carried out by adding a solid polyester in the form of a chip (chip) to the injection molding machine. The polyester chip discharges a polyester polymerized with a dicarboxylic acid component and a diol component into cooling water, cuts the same into a predetermined size, and manufactures a chip having a pellet shape. We can manufacture together

On the other hand, since polyester has a disadvantage in that it is easy to burn rapidly after ignition in flame retardancy, polyester used in various industrial fields needs to impart flame retardancy from the viewpoint of fire prevention. In order to improve flame retardancy, which is a disadvantage of the polyester, the flame retardant may be improved by adding a reactive flame retardant together with a raw material during polyester polymerization or by mixing a polyester resin and an additive flame retardant during molding.

The flame retardant includes a halogen flame retardant containing a halogen compound and a non-halogen flame retardant containing no halogen compound, typically a phosphorus flame retardant. The halogen flame retardant is mainly used with a metal compound as an auxiliary flame retardant. The halogen flame retardant has a disadvantage in that it adversely affects the product properties and manufacturing process, and when using the halogen flame retardant it is necessary to add a mixture of a halogen-containing compound and a metal compound in an excessive amount, which may lower the processability and mechanical properties In addition, since it has disadvantages such as generation of toxic gas, mainly phosphorus-based flame retardants are used which are less colored, have excellent light resistance, and do not generate harmful substances during combustion.

In the case of using the phosphorus-based flame retardant as described above, the polymerization reactivity is slightly lower than that of pure polyester, the melting point (Melting Temperature) is lowered, and the melt ratio is increased, there is a problem that the defect rate during film production is increased. Accordingly, there is a demand for the development of alternatives to increase the flame retardancy using phosphorus-based flame retardants while lowering the melt resistivity and the degree of coloring.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a flame retardant polyester composition comprising a polyester resin, a phosphorus-based flame retardant and an electrostatic pinning agent.

In addition, another object of the present invention is a resin matrix comprising a copolymer of polyester and phosphorus flame retardant; And it aims to provide a flame-retardant polyester film comprising an electrostatic pinning agent uniformly dispersed in the resin matrix.

Another object of the present invention is to provide a method for producing the flame retardant polyester film using the flame retardant polyester composition.

In order to achieve the above object, the present invention provides a flame retardant polyester composition comprising a polyester, a phosphorus-based flame retardant and an electrostatic pinning agent.

The present invention also provides a resin matrix comprising a copolymer of polyester and a phosphorus flame retardant; And it provides a flame retardant polyester film comprising an electrostatic pinning agent uniformly dispersed in the resin matrix.

The present invention also provides a method for producing the flame retardant polyester film using the flame retardant polyester composition.

Hereinafter, the present invention will be described in detail.

The present invention relates to a flame retardant polyester composition comprising a polyester, a phosphorus flame retardant and an electrostatic pinning agent. The composition is intended to produce a polyester film, and when the polyester film is manufactured using the composition, the flame retardant performance is not only established but the electrostatic pinning property is maintained while maintaining the inherent mechanical and thermal properties of the polyester. By improving the melt resistivity due to the effect of the phosphorous compound there is an advantage that can improve the problem that a large number of defective products during film production.

The polyester may be a conventional homopolymerized polyester or copolyester which can be produced by esterification or transesterification of dicarboxylic acid or ester derivatives thereof with diol or ester derivatives thereof, for example by melt polycondensation.

The dicarboxylic acid or ester derivatives thereof may be, for example, terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, phthalic acid, 5-sodium sulfonisophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3- Cyclohexanedicarboxylic acid or ester derivatives thereof, and the like.

The diol or its ester derivative is composed of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol, 1,4-cyclohexanedimethanol, bisphenol A and bisphenol S It may be any one selected from the group.

The phosphorus-based flame retardant may be a compound represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group.

The phosphorus flame retardant may be 1,000 to 40,000 ppm, preferably 4,000 to 10,000 ppm, based on the phosphorus (P) atom for the entire polyester composition. That is, the content of the phosphorus-based flame retardant is preferably to include 1,000 ppm or more based on the phosphorus (P) atoms for the entire composition, in order to ensure the flame retardant performance of the entire composition, and to reduce the mechanical and thermal properties inherent in the polyester resin In order to block, it is preferable that the content of a phosphorus atom is 40,000 ppm or less based on the phosphorus (P) atom with respect to the whole composition.

The electrostatic pinning agent is an additive added to improve the electrostatic pinning properties of the resin composition, preferably may be any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ , and more Preferably NaOH. The electrostatic pinning agent may be 10 to 5,000 ppm, preferably 50 to 3,000 ppm with respect to the entire polyester composition. The amount of the electrostatic pinning agent is preferably at least 10 ppm with respect to the whole composition in order to reduce the electrostatic pinning effect and the color change, that is, yellowing during the polyester polymerization, in order to block the deterioration of mechanical properties during secondary processing, It is preferable that it is 5,000 ppm or less with respect to the whole composition.

In addition, the electrostatic pinning agent may further include magnesium acetate. The magnesium acetate can not only improve the pinning property, but also act as a catalyst in the esterification reaction.

In addition, the composition of the present invention may further include at least one selected from the group consisting of trimethyl phosphate as a heat stabilizer and silica as an inorganic particle as an extensible enhancer. The heat stabilizer may impart a pinning property improvement effect in addition to the heat stabilizer effect.

In addition, the composition of the present invention is one or more selected from the group consisting of germanium compounds including auxiliary flame retardants, pigments or dyes, glass fiber reinforcing agents, fillers, heat-resistant agents, impact aids and chromatic brighteners for improving color and germanium oxide Conventional additives such as color improvers may further be included.

The present invention also relates to a method for producing a polyester film using the flame retardant polyester composition.

In the present invention, the polyester film is melt-extruded using a conventional manufacturing method, for example, a conventionally known T-die method using the polyester composition to obtain an unstretched sheet, and the obtained unducted sheet is machined. To 2 to 7 times, preferably 3 to 5 times, and then 2 to 7 times, preferably 3 to 5 times in a direction perpendicular to the machine direction can be prepared by a method for producing.

In one embodiment of the present invention, the method for producing a polyester film is a mixture of the dicarboxylic acid or its ester derivatives and the diol or its ester derivatives to prepare a slurry and a direct ester reaction to proceed a low molecular weight material (low molecular weight oligomer) Preparing a; After adding the electrostatic pinning agent comprising the phosphorus-based flame retardant and NaOH of the general formula (1) to the low molecular weight material, and after adding an additional additive, performing a polycondensation reaction to prepare a flame-retardant polyester resin and the flame-retardant polyester resin Melt extrusion and stretching to obtain a polyester film. The electrostatic pinning agent, preferably any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ , more preferably NaOH can be added together with the phosphorus-based flame retardant of Formula 1 In addition, it may be added after performing the polycondensation reaction. In addition, the step of preparing the flame retardant polyester resin may be carried out by polymerization in the presence of a catalyst. In addition, the step of compression drawing of the polyester to obtain a polyester film may be preferably carried out by melt extrusion of the polyester resin, the method of biaxial stretching.

Melt extrusion of the polyester resin may be carried out at a high temperature of 280 ℃ or more, the biaxial stretching is performed after the extrusion process, and cooled to room temperature using a casting drum circulating a cooling water therein amorphous polyester sheet preparing a sheet; Stretching the sheet 2 to 7 times, preferably 3 to 5 times, in the same direction as the moving direction of the sheet using rolls arranged in the vertical direction or the horizontal direction; And stretching the stretched sheet 2 to 7 times, preferably 3 to 5 times, perpendicular to the traveling direction in a tender capable of preheating the stretched sheet with hot air.

When the flame retardant film is manufactured by the method for producing a flame retardant polyester film according to the present invention, any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ , preferably NaOH is included. Therefore, compared to the conventional flame retardant polyester film manufacturing method using a flame-retardant flame retardant can not only solve the problem that a large number of defective products during film production, but also in the case of the produced polyester film, the pinning properties are significantly improved, the polyester inherent It is possible to maintain the mechanical properties of the, there is an advantageous effect that can maintain the excellent color by blocking the yellowing of the polyester film.

The present invention also provides a resin matrix comprising a copolymer of polyester and a phosphorus flame retardant; And it relates to a polyester film comprising an electrostatic pinning agent uniformly dispersed in the resin matrix.

More specifically, the polyester film is a resin matrix comprising a copolymer of polyester and a phosphorus flame retardant represented by the following formula (1); And it relates to a polyester film comprising any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ uniformly dispersed in the resin matrix.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group.

The resin matrix may include a copolymer of polyester and a phosphorus flame retardant represented by Chemical Formula 1. In addition, any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ , the electrostatic pinning agent, preferably NaOH is uniform in the resin matrix comprising a copolymer of the polyester and phosphorus-based flame retardant Can be distributed.

More specifically, the film is prepared from the flame retardant polyester composition, the resin matrix comprising a copolymer of the polyester and the phosphorus-based flame retardant represented by the formula (1); And the electrostatic pinning agent uniformly dispersed in the resin matrix, that is, any one selected from the group consisting of NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ , preferably a polyester film including NaOH. have.

The content of the phosphorus flame retardant of the flame retardant polyester composition is 4,000 ppm to 10,000 ppm based on the phosphorus content relative to the total weight of the polyester composition, and the NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ groups. Any one selected from, preferably the NaOH content may be 50 ppm to 5,000 ppm, preferably 100 ppm to 3,000 ppm based on the total weight of the polyester composition.

Preferably the film may be prepared by a method for producing a polyester film using the flame retardant polyester composition of the present invention.

Since the flame-retardant film contains NaOH, it is possible to improve the pinning property of the flame-retardant polyester film, excellent mechanical properties compared to the conventional flame-retardant film, advantageous to maintain the excellent color by blocking the yellowing of the polyester film It works.

As described above, the flame-retardant polyester composition according to the present invention and the method for producing a flame-retardant polyester film using the composition, including the phosphorus-based flame retardant, improved the disadvantages of the weak polyester resin to heat added heat resistance In addition, by adding the electrostatic pinning agent to significantly improve the pinning property, which is a disadvantage of the flame-retardant polyester containing a conventional phosphorus-based flame retardant to maintain the inherent mechanical properties of the polyester, block the yellowing of the polyester film to maintain excellent color In order to solve the problem of many defects occurring during film production, its industrial value will be very large.

Hereinafter, preferred examples and comparative examples are presented to aid in understanding the present invention. However, the following examples are intended to illustrate the present invention without limiting it thereto.

Manufacturing example

Example  1

45 parts by weight of ethylene glycol (Ethylene Glycol) was added to the esterification reactor with respect to terephthalic acid and 100 parts by weight of terephthalic acid, and then pressurized at a pressure of 1.0 kg / cm 2 to proceed with the esterification reaction while water was discharged out of the reactor. BHET (bis-β-hydroxyethyl terephthalate) was prepared.

A polyester composition was prepared by adding 3-hydroxyphenylphosphinylpropane carboxylic acid, NaOH, magnesium acetate, and trimethylphosphate, which are phosphorus flame retardants, to the prepared BHET.

More specifically, 4.6 wt% of 3-hydroxyphenylphosphinylpropane carboxylic acid, which is a phosphorus-based flame retardant, based on the total weight of the polyester composition in the prepared BHET (6,400 ppm per 100 parts by weight of the polyester composition) , By adding 0.05 wt% of NaOH, 0.08 wt% of magnesium acetate and 0.038 wt% of trimethylphosphate, and performing a polycondensation reaction in the presence of antimony trioxide under high temperature and high vacuum conditions of conventional polyethylene terephthalate (PET), The flame retardant polyester composition was prepared in a pellet shape.

Using the flame retardant polyester composition, melt extrusion was carried out by a conventional T-die method, an unstretched sheet was obtained through a casting die by using an electrostatic pinning method, and the obtained non-flammable sheet was tripled in the machine direction. The flame-retardant polyester film was prepared by stretching and then stretching by three times in a direction perpendicular to the machine direction.

Example  Preparation of 2

The NaOH content was prepared in the same manner as in Example 1, except that NaOH was adjusted to 0.1 wt% based on the BHET.

Example  3 Preparation of

The NaOH content was prepared in the same manner as in Example 1, except that NaOH was adjusted to 0.35 wt% based on the total weight of the polyester composition.

Comparative example  1

It was prepared in the same manner as in Example 1 except that NaOH and phosphorus-based flame retardant were not added.

Comparative example  Preparation of 2

Without the addition of NaOH, triethylammonium hydroxide was prepared in the same manner as in Example 1 except that 0.05% by weight of the total weight of the polyester composition.

Comparative example  3 Preparation of

The triethylammonium hydroxide was prepared in the same manner as in Example 1, except that 0.05 wt% of triethylammonium hydroxide was added to the total weight of the polyester composition.

Experimental Example

1) flame retardant; Marginal oxygen index ( Limit Oxygen Index , LOI )

Flame-retardant polyester polymer was applied to the surface of the sample with a torch in a fire testing technology to check the continuation and expansion of the ignition visually and measured five times at 5 second intervals. When the sample did not catch fire or self extinguished, the oxygen fraction (Vo ₂ ) in the air was increased, a new sample was set in the measuring instrument, and the above flame retardancy evaluation was performed. The same test was conducted to increase the fraction of oxygen in the air until the point of ignition continued or enlarged due to the fire on the sample. The limit oxygen index was calculated by the following equation 1 by checking the fraction of oxygen with respect to the entire gas at the time when the sample was held or expanded on fire.

2) Melt resistivity cm )

Charge the flame-retardant polyester polymer in a test tube, immerse it in a silicone oil bath to completely melt it, then continue to pass nitrogen gas to remove bubbles while preventing decomposition, and insert a platinum electrode into the molten resin to hold for 10 minutes Next, a DC voltage of 120V was applied. The current value immediately after application was read, and the specific resistance was calculated according to the following formula (2).

In the above equation, i is the current value A, A is the cross-sectional area of the electrode in cm2, and the unit of distance between the electrodes is cm.

3) casting Sheet  Surface condition

The unstretched sheet was visually observed to confirm the state of the surface.

4) Resin color (b value)

The resin color was measured by using a color difference meter (Nippon Denshoku, Model No. SE-2000) of the flame-retardant polyester polymer prepared.

5) DEG  And- COOH  content

DEG and -COOH content measurements were determined by commonly used methods used in the analysis of polyester polymers, namely polyethylene terephthalate (PET).

Each result measured by the above measurement method is shown in Table 1 below.

As shown in Table 1, the embodiment of the present invention was confirmed that the LOI is significantly superior to Comparative Example 1 and Comparative Example 2 without the addition of a phosphorus-based flame retardant, excellent flame retardancy. On the other hand, the embodiment of the present invention was confirmed that the melt resistivity is lower than that of Comparative Example 3 containing only the phosphorus-based flame retardant and TEAH, and almost the same level as that of Comparative Example 2 containing no phosphorus-based flame retardant, the surface state of the casting sheet It was confirmed that it was good, and it was confirmed that the pinning property was remarkably improved. In addition, as the content of NaOH increases, it was confirmed that the -COOH content slightly increased.

In view of the above results, the present invention is remarkably excellent in flame retardancy, improved appearance and pinning properties, and excellent flame retardancy and excellent appearance when compared to the comparative example without NaOH, and using the flame retardant polyester composition of the present invention. It was confirmed that it could be prepared.

Claims (9)

Polyester; Phosphorus-based flame retardant represented by the following formula (1); And Flame retardant polyester composition comprising: at least one electrostatic pinning agent selected from the group consisting of NaOH, and KOH: [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. The flame retardant polyester composition of claim 1, further comprising at least one selected from the group consisting of magnesium acetate and trimethyl phosphate. The method according to claim 1 or 2, The content of the phosphorus flame retardant is 4,000 ppm to 10,000 ppm based on the phosphorus content relative to the total weight of the polyester composition, and the amount of the electrostatic pinning agent selected from the group consisting of NaOH and KOH is based on the total weight of the polyester composition. 50 ppm to 5,000 ppm flame retardant polyester composition. The flame retardant polyester composition according to claim 1 or 2, further comprising at least one selected from the group consisting of a fluorescent brightener and a germanium compound. A method for producing a polyester film using the flame retardant polyester composition according to claim 1. The method of claim 5, wherein the film manufacturing method Dicarboxylic acid or ester derivatives thereof, diol or ester derivatives thereof, phosphorus flame retardant of formula 1 and at least one electrostatic pinning agent selected from the group consisting of KOH and flame retardant polyester resin Manufacturing step and Melt extruding and stretching the flame retardant polyester resin to obtain a polyester film Polyester film manufacturing method comprising: [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. A resin matrix comprising a copolymer of polyester and a phosphorus flame retardant represented by Formula 1 below; And at least one electrostatic pinning agent selected from the group consisting of NaOH and KOH uniformly dispersed in the resin matrix: [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. The method of claim 7, wherein Polyester film further comprises one or more selected from the group consisting of magnesium acetate and trimethyl phosphate. The polyester film of claim 7 or 8, further comprising at least one selected from the group consisting of a fluorescent brightener and a germanium compound.