KR101761708B1 - Polyester Foam Improving for Fire-retardant And Method For Preparing The Same - Google Patents

Abstract

The present invention relates to a polyester foam having improved flame retardancy. The polyester foam according to the present invention can be prepared by appropriately controlling the reaction type flame retardant and the addition type flame retardant, without lowering the physical properties of the conventional polyester foam, The flame retardant performance is improved and the flame retardancy of the polyester foam is prevented from deteriorating even after a lapse of time.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a polyester foam having improved flame retardancy,

The present invention relates to a polyester foam.

BACKGROUND OF THE INVENTION [0002] Synthetic resins including polyester resins are widely used throughout the industry due to the demand for lightweight for energy saving. BACKGROUND ART [0002] Lightweight synthetic resin has been attempted to achieve its object by producing foams.

The polyester has excellent mechanical properties, excellent heat resistance and chemical resistance, but has difficulty in foam molding as a crystalline resin. However, due to the development of the technology, it has become possible to manufacture a foam through a foaming process in melt extrusion of polyester. U.S. Patent No. 5,099,991 discloses a technique for producing a foam by extrusion foaming by adding a cross-linking agent to the polyester.

However, the foamed molded article using a polyester resin is liable to be subjected to secondary fire due to its low flame retardant performance when exposed to fire. As a method for solving such problems, a halogen flame retardant has been used to enhance flame retardancy. However, the flame retardant performance of the halogen-based flame retardant agent is excellent, but the occurrence of casualties in the fire has a problem due to the emission of toxic gas due to the fire rather than the flame itself. Further, there is a problem that toxic substances are generated even when the polyester is discarded. As a result, there has been a problem in terms of stability when using the polyester resin.

On the other hand, a flame retardant can be described as a substance that slows ignition and prevents expansion of combustion by adding a compound having a high flame retardancy-giving effect such as halogen, phosphorus, nitrogen, and metal hydroxide compound to a polymer material having easy- . However, the flame retardant should be used as a product because it is difficult to use it as an actual product simply by exerting a flame retardant effect, and there is little generation of fumes and toxic gas during combustion and good compatibility with a base polymer. It is possible. In addition, it should not affect the mechanical properties of the product.

Accordingly, conventionally, various methods for improving the flame retardancy of the foamed molded body, delaying the ignition time, and slowing the propagation of the flame have been proposed. Mainly used methods of flame retardation of polymers include the production of heat-resistant polymers (CPE, PVC, etc.) by changing the molecular structure, the method of chemically bonding the flame retardant component in the foamable mold structure (reactive flame retardant), the addition of the flame retardant physically (Addition type flame retardant), flame retardant coating or painting, or a method of improving the heat resistance by changing the product design. In general, flame retardant is added to general flame retardant.

However, if the content of the reactive type flame retardant is increased to increase the content (P content exceeds 6500 ppm), the polymerization reactivity may be deteriorated. When the addition type flame retardant is added in a certain amount or more, May occur.

Accordingly, development of a foamed molded article having improved flame retardancy by appropriately adjusting the content of the reactive type flame retardant and the additive type flame retardant has been desired.

U.S. Pat. No. 5,099,991.

It is an object of the present invention to provide a polyester foam having improved flame retardancy.

In order to solve the above problems,

After 30 days from immediately after the production, a total amount of heat released for 5 minutes after initiation of heating as measured on the basis of KS F 5660-1 is 7 MJ / m ² or less.

Further, in order to solve the above problems,

Polymerizing a phosphorus flame retardant to produce a polyester resin; And

Adding the additive type flame retardant to the polyester resin in the range of 0.1 to 10 wt% and foaming at a density in the range of 30 to 200 kg / m ³ ,

Wherein the phosphorus (P) content in the polyester resin is in the range of 6,600 to 13,000 ppm based on phosphorus (P) atoms.

The polyester foam according to the present invention improves the processability and the flame retardancy without deteriorating the physical properties of the conventional polyester foam and prevents the flame retardancy from deteriorating even after a lapse of a predetermined time.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Therefore, the configurations shown in the embodiments described herein are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents And variations.

Hereinafter, the polyester foam according to the present invention will be described in detail.

As one example, the polyester foam according to the present invention may have a total heat release amount of 7 MJ / m ² or less for 5 minutes after initiation of heating measured by KS F 5660-1 after 30 days from immediately after production have. Specifically, the total heat release amount (E ₃₀ ) of 1 to 7 MJ / m ² for 5 minutes after initiation of heating as measured on the basis of KS F 5660-1 after 30 days immediately after the production of the polyester foam according to the present invention, 2 to 6.8 MJ / m ² , 3 to 6.5 MJ / m ² , 3.5 to 6.3 MJ / m ² , 4 to 6.2 MJ / m ² or 5 to 6 MJ / m ² . The polyester foam according to the present invention realizes excellent flame retardancy by satisfying the total heat release amount after 30 days from immediately after production to satisfy the above range.

As one example, a polyester foam according to the present invention may comprise,

The following general formula (1) can be satisfied.

[Formula 1]

E ₃₀ / E ₀ ? 1.35

In the general formula 1,

E ₃₀ means the total heat release amount (MJ / m ² ) for 5 minutes after initiation of heating as measured on the basis of KS F 5660-1 after 30 days from immediately after the production of the polyester foam,

E ₀ means the total heat release amount (MJ / m ² ) for 5 minutes after the initiation of heating as measured on the basis of KS F 5660-1 immediately after the production of the polyester foam.

Specifically, immediately after the production of the polyester foam according to the present invention, 30 days elapsed immediately after the production of the polyester foam relative to the total heat release amount (MJ / m ² ) for 5 minutes after the initiation of heating as measured on the basis of KS F 5660-1 The ratio of the total heat release amount (MJ / m ² ) for 5 minutes after initiation of heating measured by KS F 5660-1 may be 1.35 or less, 1 to 1.3, 1.03 to 1.27 or 1.05 to 1.25. It can be seen that the ratio of the total heat release amount after 30 days to the total heat release amount immediately after the production of the polyester foam according to the present invention satisfies the above range, whereby the deterioration of the flame retardancy is prevented even if the time passes.

In the general formula (1), E ₃₀ may be 7 MJ / m ² or less and E ₀ may be 6 MJ / m ² or less. Specifically, the total heat release amount (E ₃₀ ) of 1 to 7 MJ / m ² for 5 minutes after initiation of heating as measured on the basis of KS F 5660-1 after 30 days immediately after the production of the polyester foam according to the present invention, 2 to 6.8 MJ / m ² , 3 to 6.5 MJ / m ² , 3.5 to 6.3 MJ / m ² , 4 to 6.2 MJ / m ² or 5 to 6 MJ / m ² . The total heat release amount (E ₀ ) for 5 minutes after the initiation of heating as measured on the basis of KS F 5660-1 immediately after the preparation of the polyester foam according to the present invention is 1 to 6 MJ / m ² , 2 to 5.8 MJ / m ² , 3 to 5.5 MJ / m ² , 3.5 to 5.3 MJ / m ² , or 4 to 5 MJ / m ² . It can be seen that excellent flame retardancy can be realized by satisfying the total heat release amount after 30 days from immediately after the production of the polyester foam according to the present invention and the total heat release amount immediately after the production of the polyester foam according to the present invention.

As one example, a polyester foam according to the present invention may comprise,

Wherein the phosphorus (P) content is in the range of 6,600 to 13,000 ppm, based on phosphorus (P)

The melting point (Tm) according to differential scanning calorimetry (DSC) may be in the range of 230 to 260 ° C.

Specifically, the phosphorus content is in the range of 6,700 to 11,500 ppm, 6,800 to 11,000 ppm, 6,900 to 10,500 ppm, 7,000 to 10,000 ppm, 7,500 to 9,500 ppm, 7,800 to 9,000 ppm, or 8,000 to 9,000 ppm . When the phosphorus content is in the above range, satisfactory flame retardancy is exhibited and the lowering of the foaming processability is prevented.

Specifically, the melting point may be 230 to 260 캜, 232 to 255 캜, 235 to 250 캜. In the polyester foam according to the present invention, the amount of the reaction-type flame retardant and the addition-type flame retardant are appropriately controlled so that the melting point is prevented from lowering and the melting point within the above range is maintained. The polyester foam according to the present invention has properties not only in terms of heat resistance but also in mechanical strength by satisfying the above melting point, and achieves excellent flame retardant performance by keeping the total heat release amount low.

As an example, the polyester foam according to the invention may have a density (KS M ISO 845) in the range of 30 to 200 kg / m ³ . More specifically, the density is from 35 to 190 kg / m ^3, 40 to 170 kg / m ^3, 45 to 160 kg / m ^3, 50 to 150 kg / m ^3, 55 to 100 kg / m ³ or 58 to 70 kg / m < ³ >. When the density of the polyester foam according to the present invention satisfies the above range, the weight of the polyester foam is prevented from being relatively high, the elasticity is improved, and the improved flame retardant performance is realized.

The polyester foam according to the present invention suitably contains the phosphorus content and the content of the additive type flame retardant, thereby optimizing the density to the above range, thereby lowering the total heat release amount and improving the flame retardant performance.

As an example, the flexural strength (KS M ISO 844) of the polyester foam according to the present invention may range from 70 to 110 N / cm ² . Specifically, the flexural strength may be in the range of 75 to 110 N / cm ² , 80 to 110 N / cm ^2, or 80 to 100 N / cm ² .

As one example, the flexural strength ratio of density of the polyester foam may satisfy the following general formula (2).

[Formula 2]

Z / Y? 1.2

In the general formula 2, Z represents the flexural strength (N / cm ² ) of the polyester foam according to KS M ISO 844, and Y represents the density (kg / m ³ ) of the polyester foam according to KS M ISO 845.

For example, the density to flexural strength ratio of the polyester foam may range from 1.2 or more, 1.2 to 2, 1.3 to 1.8 or 1.4 to 1.6. The polyester foam according to the present invention satisfies the density to bending strength ratio in the above range, thereby realizing weight reduction and preventing deformation. This means that in the polyester foam according to the present invention, the pores may not be bonded to each other but the closed cells may be formed independently, and thus excellent heat insulation can be expected.

In the general formula 2, Z may be 70 to 110 N / cm ² , and Y may be 40 to 80 kg / m ³ . For example, Z (bending strength) is 75 to 110 N / cm ^2, 80 to 110 N / cm ^2, 80 to 100 N / cm may be in the ^second range, Y (density) of 30 to 200 kg / m ³ , 35 to 190 kg / m ^3, 40 to 170 kg / m ^3, 45 to 160 kg / m ^3, 50 to 150 kg / m ^3, 55 to 100 kg / m ³ or 58 to 70 kg / m ³ can be have.

As an example, the polyester foam according to the present invention may have a tensile strength (ASTM C 297) in the range of 1.5 to 2.5 N / mm < ² >. Specifically, the tensile strength may be in the range of 1.6 to 2.3 N / mm ² or 1.7 to 2.1 N / mm ² . When the tensile strength is in the above range, the polyester foam achieves improved elasticity and strength performance.

Hereinafter, the method for producing the polyester foam according to the present invention will be described in detail.

A method for producing a polyester foam according to the present invention comprises:

Polymerizing a phosphorus flame retardant to produce a polyester resin; And

Adding the additive type flame retardant to the polyester resin in a range of 0.1 to 10 wt%

The content of phosphorus (P) in the polyester resin may be contained in the range of 6,600 to 13,000 ppm based on the phosphorus (P) atom.

As one example, the phosphorus flame retardant may be any one or more compounds of the following general formulas (1) to (3) as a reactive flame retardant.

 [Chemical Formula 1]

(2)

(3)

In the above Chemical Formulas 1 to 3, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are hydrogen or an alkyl group having 1 to 5 carbon atoms.

Generally, the flame retardant agent is a flame retardant effect which suppresses or alleviates the combustion by interfering with the combustion stage such as heating, decomposition, and heat generation during the plastic burning process, and the flame retardant agent can be classified into a reactive flame retardant agent and an additive flame retardant agent.

The reactive flame retardant is a type that reacts chemically with a functional group in the molecule and is bound by external conditions, and has a characteristic of continuing the flame retardancy. The addition type flame retardant is a method of obtaining a flame retardant effect by physically mixing, adding and dispersing a substance of a flame retardant substance into a foam. In addition, there is a method of improving heat resistance by coating or painting a flame retardant.

Among them, the halogen-based flame retardant exhibits its flame-retarding effect by capturing OH and H, which are active radicals, which act as a propellant of combustion, in the combustion process of HX, which is a halogen compound. In addition, HX has the effect of diluting combustible gas and blocking oxygen by generating incombustible gas. Iodine (I) in the halogen element has the most excellent effect as a radical scavenger, but it is expensive, has a disadvantage in that it has insufficient heat resistance and light resistance, and fluorine (F) shows little effect as a radical scavenger. On the other hand, bromine (Br) has the ability to effectively remove radicals and is used most often among halogen-based flame retardants. However, halogen gases generated at this time may corrode metals such as molds and electric wires and may be harmful to human bodies. Therefore, rather than using a halogen flame retardant alone, a high flame retardant synergistic effect can be obtained by using it in combination with a halogen stabilizer such as a hydrotalcite compound, an antimony flame retardant, zinc borate, or phosphorus flame retardant.

Phosphorus Containing Flame Retardants react with flammable materials in the combustion process to form carbonaceous on the polymer surface, which blocks the oxygen required for combustion and shows flame retardant effect. In particular, the phosphorus flame retardant reacts with the oxygen element in the polymer to dehydrate carbonization to exhibit a flame retarding effect, so that the flame retardant can be effectively performed in the polymer containing the oxygen element. The phosphorus flame retardant produces phosphorylated polyphosphoric acid by pyrolysis. At this time, phosphoric acid and polyphosphoric acid produced by the esterification and dehydrogenation reaction generate char, and this car exerts a flame retarding effect by blocking oxygen and heat. Unlike flame retardant effect in gas state, phosphorus flame retardant induces flame retardant effect mainly in solid state. For this reason, when a phosphorus flame retardant and a halogen flame retardant are used together, a flame-retarding synergistic effect may be obtained.

Inorganic flame retardant is antimony trioxide (Sb ₂ O _3), antimony pentoxide (Sb ₂ O ₅₎ is most aluminum hydroxide (Al (OH) ₃₎ use in the flame retardant, and then to magnesium hydroxide _{(Mg (OH) 2),} , Tin oxide, zirconium (Zr) compound, borate, ammonium polyphosphate, molybdenum compound and the like. Among the flame retardants, aluminum hydroxide and magnesium hydroxide are metal hydroxide compounds as flame retardants that suppress the combustion phenomenon by depriving the combustion point while suppressing the combustion gas. They generate H ₂ O during combustion and turn into water vapor, diluting the combustible gas and lowering the temperature around the combustion point, thereby suppressing the combustion phenomenon.

As an example, in the step of adding the additive type flame retardant in the range of 0.1 to 10 wt% to the polyester resin according to the present invention and foaming at a density in the range of 30 to 200 kg / m ³ , the content of the additive type flame retardant is specifically 0.2 to 10 wt% And may range from 8 wt%, 0.25 to 7.5 wt%, 0.3 to 7 wt%, 0.4 to 6.5 wt%, 0.5 to 5.5 wt%, 0.8 to 5 wt%, 1 to 3.5 wt% or 1.5 to 2.5 wt%. When the content of the additive type flame retardant is within the above range, the flame retardancy is remarkably improved without deteriorating physical properties such as flexural strength and tensile strength of the foam. The polyester foam according to the present invention can improve the processability of foaming by controlling the amount of the addition type flame retardant to be in the above range while including the reactive type flame retardant, and it is possible to solve the problem that the flame retardancy is deteriorated after a lapse of a predetermined time.

Further, in the foaming step, the density may be in the range of 30 to 200 kg / m < ³ >. More specifically, the density is from 35 to 190 kg / m ^3, 40 to 170 kg / m ^3, 45 to 160 kg / m ^3, 50 to 150 kg / m ^3, 55 to 100 kg / m ³ or 58 to 70 kg / m < ³ >. When the density according to the present invention satisfies the above range, it is possible to realize an improved processability, prevent the polyester foam from being formed to have a relatively high weight, improve the elasticity, and realize improved flame retardant performance.

As an example, in the process for producing a polyester foam according to the present invention, the phosphorus (P) content in the polyester resin may be contained in the range of 6,600 to 13,000 ppm based on the phosphorus (P) atom. Specifically, the phosphorus content is in the range of 6,700 to 11,500 ppm, 6,800 to 11,000 ppm, 6,900 to 10,500 ppm, 7,000 to 10,000 ppm, 7,500 to 9,500 ppm, 7,800 to 9,000 ppm, or 8,000 to 9,000 ppm . More specifically, the phosphorus content of the reactive flame retardant may be about 6,500 ppm, and the phosphorus content of the additive flame retarder may be in the range of 100 to 6,500 ppm, 200 to 6,500 ppm, 500 to 6,500 ppm, 900 to 6,500 ppm, 1,500 to 6,500 ppm ppm or from 2,000 to 6,500 ppm. When the content of phosphorus in the resin is within the above range, it exhibits a satisfactory flame retardant performance, has a viscosity enough to form a stable cell by collecting bubbles during foaming through an extruder, has excellent density and expansion ratio, Can be prevented from being lowered.

The polyester foam according to the present invention improves the polymerization reactivity by controlling the phosphorus content of the reactive flame retardant to the above range and controls the amount of the additive flame retardant to be in the above range, thereby realizing remarkably improved processability and flame retardant performance .

As one example, the additive type flame retardant according to the present invention may include an alkali-based phosphoric acid containing at least one alkali metal selected from the group consisting of Na, K and Li. Specific examples of the alkaline phosphates include NaH ₃ P ₂ O ₇ , Na ₂ H ₂ P ₂ O ₇ , Na ₂ H ₂ P ₂ O ₇ (H ₂ O) ₆ , Na ₃ HP ₂ O ₇ , Na ₃ HP _{2 O 7 (H 2 O)} , Na 3 HP 2 O 7 (H 2 O) 9, Na 4 P 2 O 7, Na 4 P 2 O 7 (H 2 O) be _10, but not are not limited to, More specifically, the present invention may include NaH ₃ P ₂ O ₇ .

Specifically, in the method for producing a polyester foam according to the present invention, the step of polymerizing a phosphorus-based flame retardant to produce a polyester resin is a step of polymerizing at least one of the compounds of the above formulas (1) to (3) And more specifically, mixing an aromatic dicarboxylic acid and a glycol component, and then melting the mixture at a temperature of 200 캜 or more; A catalyst is added to the mixture of the dicarboxylic acid component and the glycol component melted and the esterification reaction or the esterification exchange reaction is carried out at a temperature in the range of 200 to 250 ° C for at least 1 hour to prepare an oligomer having a polymerization degree of 3 or more, Leaching phosphorus and ethanol or water; A phosphorus-based flame retardant containing at least one of the compounds of the above formulas (1) to (3) is added to the prepared oligomer having a degree of polymerization of 3 or more and an esterification reaction or transesterification reaction is further carried out at a temperature in the range of 200 to 250 ° C for 30 minutes And distilling off water or methanol wool which is a by-product; And further subjecting the prepared oligomer to condensation polymerization at a temperature of 260 to 290 ° C and a vacuum degree of 1.0 Torr or less for 60 to 240 minutes.

As one example, a process for producing a polyester foam according to the present invention comprises:

The step of drying the polyester resin may further comprise drying the polyester resin at a temperature in the range of 70 to 250 ° C. for at least 5 hours . The drying temperature may be in the range of 80 to 230 ° C, 100 to 200 ° C or 130 to 180 ° C, and the drying time may be in the range of 5 to 20 hours, 6 to 18 hours, 7 to 15 hours, or 8 to 10 hours have.

As one example, the method for producing a polyester foam according to the present invention may include a step of, after the step of drying the polyester resin, preparing a molten resin obtained by melt-blending a polyfunctional crosslinking additive in a dried resin. At this time, the molten resin obtained by melt-mixing the cross-linking additive may be obtained by melt-blending the cross-linking additive into the melt obtained by melting the dried polyester resin. The additive type flame retardant according to the present invention can be added to the molten resin.

The polyfunctional additive may be at least one selected from the group consisting of trimethyl propane, an isocyanate compound, a carbomide compound, an ethylene-acrylate-glycidyl methacrylate compound, and a mixture thereof. Since the crosslinking additive is an essential component for improving the processing characteristics in the foaming molding of the present invention, uniform mixing is essential, but it may be difficult to uniformly mix it because an extremely small amount is used. This problem can be solved by, for example, re-melting the master batch chip made by melt-mixing the flame-retardant polyester resin and the crosslinking additive to increase the uniformity.

The crosslinking additive may be included in an amount of 0.3 to 2 parts by weight based on 100 parts by weight of the dried polyester resin. When the amount of the crosslinking additive is within the above range, the flowability of the resin during extrusion foaming can be eased and the appearance can be smoothly formed.

As one example, the foam may be added to the melt obtained by melting the polyester resin, and pyrolytic foams, volatile foaming agents or a mixture thereof may be used as the foaming agent used herein. Specific examples of the thermally decomposable foam include an inorganic foaming agent containing sodium hydrogencarbonate, an azo compound, a nitroso compound, and a hydrazine compound. As a specific example of the volatile foaming agent, an organic foaming agent such as carbon dioxide gas or nitrogen, an inert gas such as propane, butane, hexane, methane and the like may be used. In the case of using a pyrolytic foaming agent or a volatile foaming agent, There are advantages to be gained.

As an example, the polyester resin may have an intrinsic viscosity of 0.5 to 2.5 dl / g. Specifically, the intrinsic viscosity may range from 0.7 to 2.3 dl / g, from 0.8 to 2.2 dl / g, or from 1 to 2.1 dl / g. When the intrinsic viscosity is in the above range, the foaming magnification and density of the foam are improved.

As one example, the polyester resin according to the present invention is not limited to a great extent as long as it can maintain the physical properties of polyester and is excellent in softness characteristics and foam forming workability. For example, the polyester resin may have biodegradability.

The polyester resin mainly used so far is a high molecular weight aromatic polyester resin produced by the condensation polymerization reaction of 1,4-butanediol with terephthalic acid. Here, the high molecular weight polyester may mean a polymer having an intrinsic viscosity [?] Of 0.8 (dL / g) or more. However, the aromatic polyester resin is excellent in physical properties such as high molecular weight, thermal stability and tensile strength, but it is not decomposed in a natural ecosystem after disposal, causing serious environmental pollution problem for a long time.

On the other hand, it is already known that aliphatic polyester has biodegradability. However, conventional aliphatic polyesters have a low melting point due to the flexible structure of the main chain and low crystallinity, are low in thermal stability upon melting, are likely to be thermally decomposed, have a high melt flow index, There is a problem that the use thereof is limited due to poor physical properties such as tear strength. The aliphatic polyester may include, for example, polyglycolide, polycaprolactone, polylactide, and polybutylene succinate.

Specific examples of the polyester include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polylactic acid (PLA), polyglycolic acid acid, PGA, PP, Polyethylene, PE, PEA, Polyhydroxyalkanoate, PHA, Polytrimethylene Terephthalate, PTT), and polyethylene naphthalate (PEN). Specifically, polyethylene terephthalate (PET) may be used in the present invention.

As an example, a polyester foam according to the present invention may be a closed cell (DIN ISO4590) where at least 90% of the cells are closed. This may mean that the measured value of the polyester foam according to DIN ISO 4590 is that at least 90% of the cells are closed cells. For example, the closed cell of the polyester foam may be 90-100% or 95-100%. The polyester foam according to the present invention has a closed cell within the above range, thereby realizing excellent heat insulating properties. For example, the number of cells of the polyester foam may comprise 1 to 30 cells, 3 to 25 cells, or 3 to 20 cells per mm.

As one example, the polyester foam may be an extrusion foam molding. Specifically, there are types of foaming methods largely bead foaming or extrusion foaming. In general, the bead foaming is a method of heating a resin bead to form a primary foam, aging the resin bead for a suitable time, filling the resin bead in a plate-shaped or cylindrical mold, heating the same again, and fusing and forming the product by secondary foaming. On the other hand, the extrusion foaming can simplify the process steps by heating and melting the resin and continuously extruding and foaming the resin melt, and it is possible to mass-produce, and the cracks, Development and the like are prevented so that more excellent bending strength and compressive strength can be realized.

As one example, the polyester foam according to the present invention may have a hydrophilizing function, a waterproof function, a flame retarding function or an ultraviolet shielding function and may be a surfactant, an ultraviolet screening agent, a hydrophilizing agent, a flame retardant, The composition may further comprise at least one functional additive selected from the group consisting of an extender, an infrared attenuator, a plasticizer, a fire retardant chemical, a pigment, an elastic polymer, an extrusion aid, an antioxidant, a filler, an antistatic agent and a UV absorber. Specifically, the polyester foam of the present invention may contain a thickener, a nucleating agent, a heat stabilizer and a foaming agent.

Although the thickening agent is not particularly limited, for example, pyromellitic dianhydride (PMDA) may be used in the present invention.

Examples of the nucleating agent include at least one of talc, mica, silica, diatomaceous earth, alumina, titanium oxide, zinc oxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, potassium carbonate, calcium carbonate, magnesium carbonate, , Sodium hydrogencarbonate, and glass beads. These fillers can serve to impart functionality and reduce the cost of the polyester foam. Specifically, Talc may be used in the present invention.

The heat stabilizer may be an organic or inorganic compound. The organic or inorganic phosphorus compound may be, for example, phosphoric acid and organic esters thereof, phosphorous acid and organic esters thereof. For example, the heat stabilizer may be a commercially available material, such as phosphoric acid, alkyl phosphate or aryl phosphate. Specifically, in the present invention, the heat stabilizer may be triphenyl phosphate, but it is not limited thereto and can be used within a conventional range without limitation as long as it can improve the thermal stability of the polyester foam.

Examples of the foaming agent include physical foaming agents such as N ₂ , CO ₂ , freon, butane, pentane, neopentane, hexane, isohexane, heptane, isoheptane and methyl chloride, azodicarbonamide- (P, P'-oxy bis (benzene sulfonyl hydrazide)], N, N'-dinitroso pentamethylene tetramine-based compounds, and the like. Specifically, CO ₂ can be used in the present invention.

The flame retardant in the present invention is not particularly limited and may include, for example, a bromine compound, phosphorus or phosphorus compound, antimony compound, metal hydroxide and the like. The bromine compound includes, for example, tetrabromobisphenol A and decabromodiphenyl ether, and the phosphorus or phosphorus compound includes an aromatic phosphoric acid ester, an aromatic condensed phosphoric acid ester, a halogenated phosphoric acid ester, and the like, and the antimony compound Antimony trioxide, antimony pentoxide, and the like. Examples of the metal element in the metal hydroxide include aluminum (Al), magnesium (Mg), calcium (Ca), nickel (Ni), cobalt (Co), tin (Sn), zinc (Zn) ), Iron (Fe), titanium (Ti), boron (B), and the like. Of these, aluminum and magnesium are preferable. The metal hydroxide may be composed of one kind of metal element or two or more kinds of metal elements. For example, metal hydroxides composed of one kind of metal element may include aluminum hydroxide, magnesium hydroxide, and the like.

The surfactant is not particularly limited, and examples thereof include anionic surfactants (e.g., fatty acid salts, alkylsulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfosuccinic acid salts and polyoxyethylene alkylsulfuric acid ester salts) , Nonionic surfactants (for example, polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, polyoxyethylene derivatives, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, (E.g., alkylamine salts, quaternary ammonium salts, alkylbetaines, amine oxides, etc.), and water-soluble polymers such as polyoxyethylene alkylamines and alkylalkanolamides), cationic and amphoteric surfactants Or protective colloids (e.g., gelatin, methylcellulose, hydroxyethylcellulose, Polyoxyethylene-polyoxypropylene block copolymer, polyacrylamide, polyacrylic acid, polyacrylic acid salt, sodium alginate, polyvinyl alcohol partial saponification, etc.), and the like have.

The waterproofing agent is not particularly limited and includes, for example, silicone, epoxy, cyanoacrylate, polyvinyl acrylate, ethylene vinyl acetate, acrylate, polychloroprene, polyurethane and polyester resins , A mixture of polyol and polyurethane resin, a mixture of acrylic polymer and polyurethane resin, a polyimide, and a mixture of cyanoacrylate and urethane.

The ultraviolet screening agent is not particularly limited and may be, for example, an organic or inorganic ultraviolet screening agent. Examples of the organic ultraviolet screening agent include p-aminobenzoic acid derivatives, benzylidene camphor derivatives, cinnamic acid derivatives, Benzotriazole derivatives, and mixtures thereof. Examples of the inorganic ultraviolet screening agent may include titanium dioxide, zinc oxide, manganese oxide, zirconium dioxide, cerium dioxide, and mixtures thereof.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited by the following description.

Example

In an ester reaction tank containing a polyethylene terephthalate oligomer obtained by direct esterification of terephthalic acid and ethylene glycol, a flame retardant of 3-hydroxyphenylphosphinylpropyne acid, which is a phosphorus-based flame retardant, is added so that the phosphorus content in the resin is 6,500 ppm After the esterification reaction was carried out at a temperature of 245 ° C for 30 minutes in the presence of manganese acetate, which is a conventional transesterification catalyst, antimony trioxide, which is a condensation polymerization catalyst, was added and then reduced to a final degree of vacuum of 1 mmHg , And the temperature was raised to 285 DEG C to perform polycondensation reaction to produce a polyester resin. The produced polyester resin was dried at 150 DEG C for 8 hours in a drier to reduce the water content so that the water content became 50 ppm or less. Then, as shown in the following Table 1, 0.3 part by weight of pyromellitic dianhydride (PMDA), 0.15 part by weight of talc (Tarc), and 0.1 part by weight of propylene oxide based on 100 parts by weight of the moisture- And 2.0 parts by weight of an additive type flame retardant (trade name: AODD, manufacturer: Synergy Material) were mixed and heated to 280 DEG C to prepare a resin melt. Then, 5 parts by weight of carbon dioxide gas as a foamed material based on 100 parts by weight of the PET resin was charged into the first extruder, and extruded and foamed to prepare a polyester foam.

Comparative Example  One

A polyester foam was prepared in the same manner as in Example 1 except that the addition type flame retardant was not added.

Comparative Example  2

A polyethylene terephthalate (PET) resin having a melting temperature of 250 ° C or higher was dried at 150 ° C to remove moisture, and a pyromellitic dianhydride (PET) resin was added to a first extruder in an amount of 100 parts by weight, 0.3 part by weight of PMDA, 0.15 part by weight of talc and 2.0 parts by weight of an additive type flame retardant (trade name: AODD, Synergy Material: manufacturer) were mixed and heated at 280 占 폚 to prepare a resin melt. Then, 5 parts by weight of carbon dioxide gas as a foamed material based on 100 parts by weight of the PET resin was charged into the first extruder, and extruded and foamed to prepare a polyester foam.

Comparative Example  3

A polyester foam was prepared in the same manner as in Example 1, except that the additive type flame retardant (trade name: AODD, manufactured by Synergy Material) was added in an amount of 15% by weight.

division Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Base Chip - FR PET
(P content: 6500 ppm) FR PET
(P content: 6500 ppm) PET FR PET
(P content: 6500 ppm) Thickener (PMDA) phr 0.3 0.3 0.3 0.3 The nucleating agent (Talc) phr 0.15 0.15 0.15 0.15 Flame retardant Kinds - AODD
(Synergy Material Co. Ltd) x AODD
(Synergy Material Co. Ltd) AODD
(Synergy Material Co. Ltd) content wt% 2.0 0 2.0 15

Experimental Example

The density, fairness, total heat release, flexural strength, and tensile strength of the above-described Examples and Comparative Examples 1 to 3 were measured. The measurement method is described below, and the results are shown in Table 2 below.

1) Density measurement

The density was measured under KS M ISO 845 conditions.

2) Fairness assessment

10 samples were randomly collected from 30 minutes after the start of the foam production to the end of the production, and the density was measured under the KS M ISO 845 condition. Samples having a deviation of 5% or less based on the density average of the 10 samples measured were " Good ', and samples with a density deviation of more than 5% were evaluated as' bad'.

3) Total emission calorimetry

The total heat released for 5 minutes after the start of heating under the conditions of KS F 5660-1 was measured.

4) Melting point (Tm) measurement

The melting point was measured using Differential Scanning Calorimetry (DSC).

5) Measurement of flexural strength

Flexural strength was measured under KS M ISO 844 conditions.

6) Tensile strength measurement

Tensile strength was measured under ASTM C 297 conditions.

division Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Phosphorus (P) content ppm 8,500 6,500 2,000 16,500 density kg / m ³ 60 60 60 170 Fairness - Good Good Good Bad Total calorific value MJ / m ² 5.0 7.5 7.5 6.5 Total calorific value
(30 days after manufacture) 6.0 7.8 10.5 15.0 The general formula 1 (E ₃₀ / E ₀ ) - 1.2 1.04 1.4 2.3 Melting point ℃ 235 235 253 235 Flexural strength N / cm ² 87 98 85 84 The tensile strength N / mm ² 2.0 1.9 2.1 1.8

Referring to the above Table 2, it can be seen that the total heat release amount is about 6 MJ / m ² even after 30 days from the production of the embodiment, and the polyester foam according to the invention shows the content of the reactive type flame retardant and the addition type flame retardant It is possible to improve the processability and improve the flexural strength and the tensile strength property of the conventional polyester foam even after 30 days after the production even when compared with Comparative Example 1 in which the additive type flame retardant is not added Flame retardant performance. In the case of Comparative Example 2, the reaction type flame retardant was not added and the processability was good, but the flame retardant performance was lowered after 30 days from the production. In Comparative Example 3, the additive type flame retardant was added in an amount of 15 wt%, and the processability and flame retardant performance immediately after the production were good, but the density was high and the processability was poor. After 30 days from immediately after the production, m < ^{2 &} gt ;, and the flame retardant performance was deteriorated after the lapse of time.

Claims (10)

delete delete delete delete delete delete Polymerizing the phosphorus flame retardant to produce a polyester resin having a phosphorus content of 6,500 ppm and having a moisture removed; And
Adding 1.5 to 2.5 wt% of an additive type flame retardant to the moisture-removed polyester resin, and foaming at a density of 30 to 200 kg / m < ³ &
The additive type flame retardant is selected from the group consisting of NaH ₃ P ₂ O ₇ , Na ₂ H ₂ P ₂ O ₇ , Na ₂ H ₂ P ₂ O ₇ (H ₂ O) ₆ , Na ₃ HP ₂ O ₇ , Na ₃ HP ₂ O _{7 2} O), Na ₃ HP ₂ O ₇ (H ₂ O) ₉ , Na ₄ P ₂ O ₇ and Na ₄ P ₂ O ₇ (H ₂ O) ₁₀ ,
The foam produced through the foaming step has a density (KS M ISO 845) of 58 to 70 kg / m ² ; The total amount of heat released for 5 minutes after the initiation of heating as measured on the basis of KS F 5660-1 after 30 days from immediately after the preparation was 7 MJ / m ² or less and the melting point (Tm) according to the differential scanning calorimetry (DSC) was 235 To 250 캜, and satisfies the following general formula (1):
[Formula 1]
E ₃₀ / E ₀ ? 1.35
In the general formula 1,
E ₃₀ means the total heat release amount (MJ / m ² ) for 5 minutes after initiation of heating as measured on the basis of KS F 5660-1 after 30 days from immediately after the production of the polyester foam,
E ₀ means the total heat release amount (MJ / m ² ) for 5 minutes after the initiation of heating as measured on the basis of KS F 5660-1 immediately after the production of the polyester foam.
8. The method of claim 7,
A phosphorus flame retardant is a reaction-type flame retardant which is any one or more of compounds represented by the following formulas (1) to (3):
[Chemical Formula 1]

(2)

(3)

In the above Chemical Formulas 1 to 3, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are hydrogen or an alkyl group having 1 to 5 carbon atoms.
delete 8. The method of claim 7,
Wherein the polyester resin has an intrinsic viscosity of 0.5 to 2.5 dl / g.