KR101767989B1

KR101767989B1 - Elastomeric Foam

Info

Publication number: KR101767989B1
Application number: KR1020150182137A
Authority: KR
Inventors: 이광희; 허미; 이승준
Original assignee: 주식회사 휴비스
Priority date: 2015-12-18
Filing date: 2015-12-18
Publication date: 2017-08-16
Also published as: KR20170073830A

Abstract

The present invention relates to an elastic foam. The elastic foam according to the present invention includes an elastic polyester resin, thereby realizing excellent thermal stability and strength, and significantly improving shear stretching force.

Description

[0001] Elastomeric Foam [0002]

The present invention relates to an elastic foam.

Polyesters are excellent in mechanical properties, and have excellent heat resistance and chemical resistance. However, it has been difficult to melt and mold by extrusion foaming as a crystalline resin. On the other hand, with the development of the technology, polyester can also be produced by the foaming process during melt extrusion. For example, U.S. Patent No. 5,099,991 discloses a method of producing an expanded molded article by extrusion foaming by adding a cross-linking agent to a polyester.

On the other hand, elastomers are used in many applications such as packaging containers, automobile interior materials, elastic fibers and the like due to their inherent elastic properties. In particular, the use of thermoplastic elastomers (TPE) is increasing due to their wide range of elastic properties. Unlike rubber materials, which can not be recycled, elastomers are also easily recycled, and therefore their demand is greatly increased.

The thermoplastic elastomer (TPE) is also referred to as a polyester-based elastic adhesive resin. The polyester-based elastic adhesive resin has two different properties, that is, a thermoplastic property that can be reformed by heating and an elastic property Is a polymer. The form of TPE is a kind of block copolymer, which consists of a hard segment block, which can generally exhibit thermoplastic characteristics, and a soft segment block, which can exhibit elastic properties of the elastomer.

It is already known that polyether ester copolymers having a polybutylene terephthalate polyester as a hard segment and a polybutylene ether ester as a soft segment exhibit excellent elastic properties. In order to lower the production cost, a polyethylene ether ester Is also used as a soft segment.

U.S. Patent No. 3,023,192 discloses hard segment / soft segment copolymerized polyesters and elastomers made therefrom. The hard segment / soft segment copolymerized polyester is prepared from a dihydroxy compound selected from (1) a dicarboxylic acid or ester forming derivative, (2) a polyethylene glycol ether, and (3) a bisphenol and a lower aliphatic glycol. Examples of the polyether used as a soft segment together with polyethylene glycol include polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and the like, and a polyether having a molecular weight of about 350 to 6,000 is used.

U.S. Patent No. 4,937,314 also discloses a thermoplastic polyetherester elastomer comprising at least 70 parts by weight of a soft segment derived from poly (alkylene oxide) glycol and terephthalic acid. The hard segment constitutes 10 to 30 parts by weight of the elastomer, and the poly (1,3-propylene terephthalate) in the hard segments is 95 to 100 parts by weight. The molecular weight of the poly (alkylene oxide) glycol is from about 1,500 to about 5,000 and the carbon to oxygen ratio is from 2 to 4.3.

Thermoplastic elastomers based on those exemplified in the prior art are soft segments mainly composed of polytetramethylene glycol ethers, copolymers of tetrahydrofuran and 3-alkyltetrahydrofuran, polyethylene glycol ethers, polytrimethylene glycol ethers and copolymers thereof Lt; / RTI > The melting point and physical properties of these copolymers are determined by the molecular weight and composition ratio of the polyalkylene glycol ether used as the soft segment. When a polyalkylene glycol ether having a high molecular weight is used to develop strong physical and elastic properties, the melting point of the polyalkylene glycol ether can not be applied to a process requiring a low melting point manufacturing process. Further, when polyethylene glycol ether is formed as a soft segment, there is a problem that when the content of the soft segment is 20 wt% or more, the thermal stability is drastically lowered.

Therefore, there is a demand for the development of an elastic foam having improved thermal stability and shear elongation by utilizing an elastomer.

U.S. Patent No. 5,099,991; U.S. Patent No. 3,023,192; U.S. Patent No. 4,937,314.

It is an object of the present invention to provide an elastic foam with improved shear elongation.

In order to solve the above problems,

Provides an elastic foam having a shear stretch of at least 30% according to ISO 1922.

Further, according to the present invention,

A step of producing an elastic resin containing at least one of a polyester resin and an elastic polyester resin; And

And a step of foaming the elastic resin.

The elastic foam according to the present invention realizes excellent thermal stability and strength and greatly improves the shear stretching force.

1 is a schematic cross-sectional view of a polyethylene glycol input facility according to the present invention.

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 elastic foam according to the present invention will be described in detail.

As an example, the elastomeric foam according to the invention may have a shear elongation in accordance with ISO 1922 of 30% or more. Specifically, the shear stretching force may be 33 to 70%, 35 to 65%, or 40 to 55%. The elastic foam according to the present invention has a shear elongation in the above-mentioned range, so that excellent elastic properties can be realized.

As an example, the elastic foam according to the present invention may have a density in the range of 20 to 200 kg / m < ³ > according to KS M ISO 845. Specifically, the density may range from 25 to 180 kg / m ³ , from 30 to 150 kg / m ³ , from 40 to 120 kg / m ³ , from 45 to 110 kg / m ³ or from 50 to 100 kg / m ³ . When the density of the elastic foam according to the present invention is in the above range, an excellent shear stretching force can be realized.

As an example, the elastic foam according to the present invention may have an average heat release rate of less than 50 MJ / m ² for 60 seconds on the basis of KS F 5660-1. Specifically, the heat release rate may be 30 MJ / m ² or less, 20 MJ / m ² or less, 1 to 20 MJ / m ² , 3 to 15 MJ / m ^2, or 5 to 10 MJ / m ² . When the heat release rate is in the above range, the elastic foam may have flame retardancy or semi-fireproof performance.

As one example, the polyester resin foam according to the present invention may have a flame retardancy of 2 or more based on KS F 4724. When the flame retardancy grade is in the above range, semi-fireproof performance can be exhibited. Therefore, the elastic foam according to the present invention can stably maintain its shape even at a high temperature.

As one example, the elastic foam according to the present invention can satisfy the following general formula (1).

[Formula 1]

Z / Y? 1.2

In the general formula 1, Z represents the flexural strength (N / cm ² ) of the elastic foam according to KS M ISO 844, and Y represents the density (kg / m ³ ) of the elastic foam according to KS M ISO 845.

For example, the density to flexural strength ratio of the elastic foam may range from 1.2 or more, 1.2 to 2, 1.3 to 1.8 or 1.4 to 1.6. The elastic foam according to the present invention can be lightweight and can prevent deformation by satisfying the density to bending strength ratio in the above range. This means that, in the elastic foam according to the present invention, the pores are not bonded to each other but the closed cells are formed independently, and thus excellent heat insulation can be expected. In the general formula 1, Z may be 70 to 110 N / cm ² , and Y may be 20 to 200 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 25 to 180 kg / m ³ , 30 to 150 kg / m ³ , 40 to 120 kg / m ³ , 45 to 110 kg / m ³ , 50 to 100 kg / m ³ or 40 to 80 kg / m ³ .

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

As one example, the method for producing an elastic foam according to the present invention comprises the steps of: preparing an elastic resin containing at least one of a polyester resin and an elastic polyester resin; And

And foaming the elastic resin.

As one example, the elastic resin may include the elastic polyester resin in an amount of 0.3 to 10 wt% based on the weight of the polyester resin. Specifically, the elastic polyester resin may include 0.35 to 7 wt%, 0.4 to 6 wt%, 0.45 to 5 wt%, or 0.5 to 3 wt%. When the elastic polyester resin is contained in the above range, a significantly improved shear stretching force can be realized while maintaining the thermal stability and strength characteristics of the polyester resin.

In the present invention, the elastic polyester resin may be an elastomer resin or an elastomer.

As one example, the elastic polyester resin according to the present invention comprises a step of esterifying ethylene glycol and butylene glycol as raw materials of a hard segment with dimethyl terephthalate under a catalyst;

And then polymerizing the polyethylene glycol, which is a raw material of the soft segment, into the esterification reaction together with a polymerization catalyst, a heat stabilizer, and a light stabilizer to perform polycondensation.

First, the esterification reaction step according to the present invention will be described as follows.

Ethylene glycol, butylene glycol, and dimethyl terephthalate are esterified to form a hard segment of the polyetherester elastomer. 1 to 50 parts by weight of ethylene glycol and 50 to 99 parts by weight of butylene glycol are added to a heat resistant pressure vessel together with an esterification reaction catalyst per 100 parts by weight of the low molecular weight diol component and subjected to an esterification reaction to prepare an oligomer solution .

Conventional polyetherester elastomers use conventional aromatic or aliphatic dicarboxylic acids such as isophthalic acid, adipic acid and succinic acid as a copolymerization raw material in order to control the melting point, while in the present invention, the ethylene glycol is used as a diol component, It has an advantage that various melting points required in the molding process of the final product can be easily controlled while maintaining the elastic properties and physical characteristics as important characteristics.

When the amount of ethylene glycol is in the range of the low molecular weight diol component according to the present invention, the required melting point can be easily controlled and the elastomeric and physical properties of the elastomer can be prevented from being lowered. The melting point can be controlled by maintaining the physical and elastic properties of the elastomer according to the charging ratio of the ethylene glycol.

As the catalyst in the esterification reaction step according to the present invention, an acetic acid-based catalyst such as zinc acetate, sodium acetate, and magnesium acetate and a catalyst such as tetranormalbutoxy titanate, tetraisopropyl titanate, tantoxide / silica oxide microcopolymer, And titanate. These catalysts may be used alone or in combination of two or more. The esterification reaction catalyst may be added in a range of 50 to 1000 ppm with respect to 100 parts by weight of the polyetherester elastomer, specifically, 200 to 700 ppm. When the amount of the catalyst is in the above range, the esterification reaction rate is prevented from being slowed, and the thermal stability of the elastomer can be prevented from being lowered.

As one example, the reaction temperature of the heat-resistant, pressure-resistant vessel in which the esterification reaction proceeds in order to distill methanol produced as a by-product may be in the range of 100 to 240 캜, specifically in the range of 150 to 210 캜. When ethylene glycol is heated for a long period of time at a reaction temperature of 240 ° C or higher in the presence of an esterification catalyst, the amount of diethylene glycol produced may be increased due to excessive dehydration reaction of ethylene glycol. The formation of diethylene glycol depends on the properties of the final elastomer It can cause deterioration.

When the esterification reaction proceeds, the condensation polymerization proceeds. The condensation polymerization step according to the present invention will be described below.

The oligomer solution obtained by the esterification reaction and the soft segment polyethylene glycol, the condensation polymerization catalyst, the heat stabilizer and the photooxidation stabilizer are introduced into a pressure-resistant / heat-resistant reactor capable of vacuum decompression, and then the pressure of 760 to 1 Torr and the pressure of 200 to 270 ° C After the excess ethylene glycol and butylene glycol are distilled off at the temperature, the condensation polymerization is completed under a high vacuum of 1 mmHg or lower in the final degree of vacuum to prepare the thermoplastic elastomer.

Conventionally, in order to feed polyethylene glycol, the vacuum state of the condensation polymerization reactor was reduced to a normal pressure state, then polyethylene glycol was added, and the reaction was further evacuated to a vacuum state. In this case, the reaction time is lengthened and the reaction time is prolonged, resulting in a problem that the thermal stability of the finally produced chip is lowered.

However, in the present invention, polyethylene glycol can be introduced under the atmospheric pressure at the initial stage of the reaction, or in a vacuum state in the course of the reaction, without returning the pressure of the reaction system to normal pressure using the apparatus of FIG. The polyethylene glycol may have a molecular weight ranging from 200 to 30000, 400 to 20000 or 500 to 15000, and these may be used alone or in combination of two or more.

1 is a schematic cross-sectional view of a polyethylene glycol input facility specially designed to introduce polyethylene glycol into a reactor in the state where the condensation polymerization reactor is maintained in a vacuum state in the present invention. The polyethylene glycol is introduced into the facility through the upper valve. The facility is designed to heat the polyethylene glycol with a band heater and a thermal insulation material, and the polyethylene glycol is fed into the reactor through the lower valve. With the equipment shown in Fig. 1, polyethylene glycol can be fed into the reactor at a reduced pressure of from 760 Torr at the initial stage of condensation polymerization to 1 Torr or less at high vacuum without returning the pressure of the reaction system to normal pressure.

Examples of the polycondensation catalyst include antimony catalysts such as antimony trioxide and antimony acetate or titanium catalysts such as tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide microcopolymer, and nano titanate. Is preferably used. The polycondensation catalyst may be added in the range of 50 to 2000 ppm based on 100 parts by weight of the elastomer, and may be in the range of 300 to 1200 ppm. When the amount of the condensation polymerization catalyst is within the above range, the rate of the condensation polymerization reaction is prevented from being slowed to obtain an elastomer having high physical properties, and the thermal stability of the elastomer can be improved.

The process for producing a polyetherester elastomer having a polyethylene glycol ether as a soft segment according to the present invention is characterized in that since the ethylene glycol ether ester and the butylene glycol ether ester are copolymerized in the hard segment, the copolymerization ratio is adjusted to maintain the physical and elastic properties It is possible to improve the thermal stability of the elastomer produced by reducing the thermal history of the inserted soft segment during the polymerization process by introducing a soft segment which is insufficient in thermal stability during the polycondensation reaction.

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

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, the elastic foam according to the present invention may be a closed cell (DIN ISO4590) with at least 90% of the cells. This may mean that the measured value according to DIN ISO 4590 of the elastic foam is that at least 90% of the cells are closed cells. For example, the closed cell of the elastic foam may be from 90 to 100% or from 95 to 100%. Since the elastic foam according to the present invention has a closed cell within the above range, excellent heat insulating properties can be realized. For example, the number of cells of the resilient foam may comprise 1 to 30 cells, 3 to 25 cells, or 3 to 20 cells per mm.

As one example, the elastic foam may be an extrusion foam molded article.

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 can be prevented, and more excellent bending strength and compressive strength can be realized.

The elastic foam according to the present invention has an effect of remarkably improving the shear stretching force without decreasing the physical properties of the conventional polyester resin foam by producing a polyester resin and an elastic polyester resin at a certain ratio.

As one example, the 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, a heat stabilizer, , At least one functional additive selected from the group consisting of infrared attenuating agents, plasticizers, fire retardants, pigments, elastic polymers, extrusion aids, antioxidants, nucleating agents, antistatic agents and UV absorbers. Specifically, the resin 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 nucleating agents can play a role in imparting functionality and reducing the cost of the resin 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 it can be used within a usual range without limitation as long as it can improve the thermal stability of the resin 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.

Manufacturing example 1 to 6: Production of elastic polyester resin

2.7 kg of ethylene glycol, 4.1 kg of butylene glycol, 13.3 kg of dimethyl terephthalate, and 13 g of tetranormalbutoxy titanate were added to a stirrerable 100 L reactor, and the mixture was heated and stirred at an initial temperature of 130 캜, It was confirmed that the phthalate melted and dissolved in the low-molecular-weight diol component. After confirming that the dimethyl terephthalate was melted and dissolved, the reaction was continued for 4 hours with heating and stirring so that the inner temperature of the reactor was gradually lowered to 205 ° C. Methanol generated as a by-product was distilled off and removed from the reactor to proceed the esterification reaction .

The oligomer solution was added to a heat resistant, internal pressure 100 liter reactor capable of vacuum decompression and stirring, and then 10.9 kg of polyethylene glycol, 100 g of a thermal stabilizer (Irganox 1010), 50 g of a light stabilizer (Tinuvin 770DF) 23 g of cittaninate were added. Condensation polymerization In the early stage, decompression and heating were progressed, and the condensation polymerization was completed under high vacuum at a final temperature of 250 ° C and a final vacuum of 1 mmHg or less to produce an elastic polyester resin.

As shown in Table 1 below, the charging ratio of ethylene glycol, the molecular weight of polyethylene glycol, the order of introduction of polyethylene glycol, and the type of polyalkylene glycol were changed, and in the same manner as in Production Example 1 except that the order of introduction of polyethylene glycol was changed, 2 to 6 were prepared.

Production Examples 1 to 4 confirmed the change in physical properties such as the melting point of the thermoplastic elastomer according to the change of the charging ratio of ethylene glycol by changing the charging ratio of ethylene glycol and butylene glycol. Production Examples 5 and 6 were prepared by changing the molecular weight of polyethylene glycol, And physical properties and elastic properties were investigated. The comparison results are shown in Table 1 below.

Comparative Manufacturing Example 1 and 2

Comparative Production Example 1 confirmed the change in the physical properties and elastic properties of the thermoplastic elastomer by using polybutylene glycol as an expensive raw material instead of polyethylene glycol as a soft segment. Comparative Production Example 2 confirmed the introduction order of polyethylene glycol in Production Example 1 6 and Comparative Production Example 1, the physical and elastic properties of the polyethyleneglycol were investigated according to the order of introduction of the polyethyleneglycol. The comparison results are shown in Table 1 below.

Example 1: elasticity Foam Produce

1 phr of the PET resin, 1 phr of the elastic polyester resin according to Preparation Example 1, 1 phr of PMDA, 1 phr of talc, 1 phr of the talc and 1 phr of the heat stabilizer were put into an extruder in a first extruder and mixed at 280 캜, CO ₂ was introduced as a blowing agent and sent to a second extruder to cool to 220 ° C.

The cooled resin melt was extruded and foamed while passing through a die to produce an elastic foam.

Example 2: elasticity Foam Produce

1 phr of PET resin, 1 phr of 0.7 phr of PMDA of the preparation example 1, 1 phr of talc, 1 phr of heat stabilizer, and 1 phr of heat stabilizer were put into an extruder in a first extruder and mixed at 280 캜. CO ₂ was introduced as a blowing agent and sent to a second extruder to cool to 220 ° C.

Example 3: elasticity Foam Produce

1 phr of PET resin, 1 phr of 0.5 phr of PMDA, 1 phr of talc, and 1 phr of heat stabilizer were put into an extruder in a first extruder, mixed at 280 ° C, and then extruded in a molten resin CO ₂ was introduced as a blowing agent and sent to a second extruder to cool to 220 ° C.

Comparative Example One: Foam Produce

100 phr of PET resin, 1 phr of PMDA, 1 phr of talc and 1 phr of heat stabilizer were put into a first extruder and mixed at 280 ° C., and CO ₂ was introduced into the molten resin as a foaming agent by using an extruder side feeder and sent to a second extruder And cooled to 220 ° C.

Experimental Example One

The properties of the elastic polyester resins according to Production Examples 1 to 6 and Comparative Production Examples 1 and 2 were measured. The measurement conditions are described below, and the measurement results are shown in Table 1.

- Melting point: Measured using a Perkin Elmer (DSC-Diamond) and when there is no heat absorption peak (no melting point), a dynamic thermal characterizer (Perkin Elmer, DMA-7, TMA mode ) Was used to measure the softening behavior.

- Intrinsic Viscosity (IV): Copolymer polyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50) to make a 0.5 wt.% Solution and then measured at 35 DEG C with a Uvold viscometer.

- Tensile strength: Measured by Instron 4467 Series.

- Tensile elongation: measured by Instron 4467 Series.

- Hardness: Measured with Handpi's Showa D durometer.

- Heat stability: The specimens for tensile strength analysis were stored in an oven at 150 ° C for 2 weeks, and the tensile strength of the specimens was measured before and after heating.

* Dimethyl terephthalate, a component of the hard segment, is excluded from the table above.

As can be seen from the results of Table 1, it can be seen that the melting point of the elastic polyester resin of Production Examples 1 to 4 was lowered by 1 ° C as the feeding ratio of ethylene glycol was increased by 1 mol%, and the elastic polyester resin And the melting point of ethylene glycol can be defined by the following equation.

Melting point (占 폚) of the elastic polyester resin = 213 - 1.02 x ethylene glycol composition (mol%)

The present invention, in which ethylene glycol is used as a diol component in comparison with a conventional method in which an aromatic or aliphatic dicarboxylic acid such as isophthalic acid, adipic acid or succinic acid is used as a copolymerization raw material in order to control the melting point of the elastic polyester resin It has been found that it has an advantage that various melting points required in the molding process of the final product can be easily controlled while maintaining the elastic characteristics and the physical properties, which are important characteristics of the elastic polyester resin.

In addition, it was possible to produce an elastic polyester resin having the same physical properties and elastic properties by using polyethylene glycol instead of expensive polybutylene glycol. In addition, the introduction sequence of polyethylene glycol was limited to the condensation polymerization reaction, It was found that it is possible to produce an elastic polyester resin excellent in heat resistance stability compared to the Comparative Production Example 2 added.

Experimental Example 2

The shear stretching force, heat release rate and flexural strength of Examples 1 to 3 and Comparative Example 1 were measured. The measurement conditions are described below, and the results are shown in Table 2.

1) Shear elongation measurement condition

Shear elongation was measured according to ISO 1922.

2) Conditions for measuring the heat release rate

The heat release rate was measured according to KS F 5660-1.

3) Bending strength measurement conditions

Flexural strength was measured according to KS M ISO 844.

division Example Comparative Example One 2 3 One Elastic polyester resin (wt%) One 0.7 0.5 Density (kg / m ³ ) 60 60 60 60 Shear elongation (%) 45 43 41 29 Heat release rate (MJ / m ² ) 10 8 7 15 Flexural Strength (N / cm ² ) 82 85 90 83

Referring to Table 2, in Examples 1 to 3, the shear elongation was measured as high as 40% or more. In Comparative Example 1, the shear elongation was measured as 29% at the same density.

Thus, the elastic foam according to the present invention, which is produced by including the elastic polyester resin, shows excellent shear elongation as well as heat release rate and flexural strength characteristics of the conventional polyester resin foam.

Claims

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Preparing an elastic resin containing 0.3 to 10 wt% of an elastic polyester resin based on the weight of the polyester resin; And
And foaming the elastic resin to produce a foam,
The elastic polyester resin may be produced by: esterifying ethylene glycol and butylene glycol, which are raw materials of hard segments, with dimethyl terephthalate and a titanium (Ti) based catalyst; And a step of polycondensation of polyethylene glycol as a raw material of the soft segment into the esterification reaction with a titanium (Ti) based polymerization catalyst, a heat stabilizer, and a light stabilizer, and having a viscosity of 1.40 dL / g to 1.45 dL / g,
Wherein said foam has a shear elongation of at least 30% according to ISO 1922 and an average heat release rate of 60 MJ / m < ² > for 60 seconds according to KS F 5660-1.

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