KR20190025352A - Foam sheet with excellent thrmoforming, and preparation method thereof - Google Patents

Abstract

The present invention relates to a foam sheet comprising, as foam of a polyester resin, a repeating unit derived from an acid component and a diol component, and to a manufacturing method thereof. The present invention is advantageous in that a polyester resin polymer contains various derivatives to control a degree of crystallinity, thereby having excellent thermoforming properties.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a foam sheet having excellent heat-

The present invention relates to a foam sheet excellent in the formation of heat and a method for producing the same.

Products that are normally used as food containers are divided into a foam type and a non-pour type. The foamed product is a product obtained by mixing polystyrene with a foaming gas and extruding it, which has the advantages of maintaining a relatively thick thickness, and maintaining shape, insulation, and cost competitiveness, but has a disadvantage in that harmful substances are detected at high temperatures. In the case of a non-foaming container, a product made of a thermally stable polypropylene in the form of a film is used. However, it has a small dimensional change rate at high temperature and has a merit that harmful substances are not detected, but it is expensive and insulation is not good.

In the past, polystyrene foam containers have been used, but the point that harmful substances are detected at high temperatures has been replaced by paper containers, which are used as disposable heat-resistant containers, .

 As modern life becomes more convenient in modern society, the use of disposable products increases and the demand for food and convenience food products is increasing due to the increase in the number of households. As a result, the demand for food packaging containers is increasing, The consumer needs for a new container material having a function according to the function of the container are increasing. Therefore, there is a need for research on packaging containers having excellent appearance, convenience, safety, and environmentally friendly performance.

Korean Patent Publication No. 10-2012-0058347

An object of the present invention is to provide a foam sheet containing a repeating unit derived from an acid component and a diol component as a foam of a polyester resin.

The present invention provides, as a foam of a polyester resin,

In the foamed state, it comprises repeating units derived from an acid component and a diol component,

Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,

Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,

The repeating unit derived from the terephthalic acid derivative and the ethylene glycol derivative is contained in an amount of 80 mol% to 99 mol% based on the total repeating units,

The foam sheet does not have a crystallization peak in the range of 110 ° C to 180 ° C in the differential scanning calorimetry (DSC) analysis.

Further, according to the present invention,

Polymerizing an acid component and a diol component to prepare a polyester resin; And

And foaming the produced resin to prepare a foam sheet,

Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,

Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,

The produced polyester resin contains 80 mol% to 99 mol% of repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative with respect to the total repeating units,

And a crystallization peak in a range of 110 ° C to 180 ° C in a differential scanning calorimetry (DSC) analysis.

The foam sheet according to the present invention has various advantages in that polyester resin polymer contains various derivatives, and thus the crystallization degree is controlled to thereby form a thermosensitive property.

1 is a graph showing a result of analyzing a foam sheet according to the present invention by differential scanning calorimetry.

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.

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.

The present invention relates to a foamed sheet of a polyester resin, wherein the polyester resin comprises a repeating unit derived from an acid component and a diol component, and a process for producing the same.

In the conventional PET foamed sheet, when the PET foamed sheet is thermoformed, the foamed sheet is crystallized by heat in the step of heating, so that the sheet is hardened and the formation of thermal property is low.

In order to solve the above problem, the foam sheet according to the present invention has a characteristic that the polyester resin polymer contains a copolymer containing a functional group to exhibit an appropriate degree of crystallinity and is excellent in the formation of heat.

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

The present invention provides, as a foam of a polyester resin,

In the foamed state, it comprises repeating units derived from an acid component and a diol component,

Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,

Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,

And a repeating unit derived from a terephthalic acid derivative and an ethylene glycol derivative in an amount of 80 mol% to 99 mol% based on the total repeating units,

Characterized in that it does not have a crystallization peak in the range of 110 ° C to 180 ° C in the differential scanning calorimetry (DSC) analysis.

Specifically, the foam sheet of the present invention may comprise a foam of a polyester resin containing a repeating unit derived from an acid component and a diol component. For example, the acid component may contain a terephthalic acid derivative, and in some cases, it may further include at least one member selected from the group consisting of isophthalic acid derivatives and phthalic acid derivatives. In addition, the diol component may contain an ethylene glycol derivative. In some cases, 2-methyl-1,3-propanediol (MP), neopentyl glycol ), 1, 2-propanediol, diethylene glycol, and isosobide may be further included.

In one example, the repeating unit derived from the terephthalic acid derivative and the ethylene glycol derivative may be contained in an amount of 80 mol% to 99 mol% based on the total repeating units. Specifically, the repeating units derived from the terephthalic acid derivative and the ethylene glycol derivative may be contained in an amount of 80 mol% to 99 mol%, 85 mol% to 99 mol%, or 90 mol% to 99 mol% based on the total repeating units. More specifically, the repeating units derived from the terephthalic acid derivative and the ethylene glycol derivative may contain 92 mol% to 99 mol% or 96 mol% to 98 mol% with respect to 100 mol% of the total repeating units. When the above-mentioned content contains repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative, the degree of crystallization of the foamed sheet can be adjusted to an appropriate range.

For example, in the acid component, the repeating unit derived from at least one member selected from the group consisting of an isophthalic acid derivative and a phthalic acid derivative may be contained in an amount of 1 mol% to 10 mol% based on the total repeating units. Specifically, the repeating unit derived from an isophthalic acid derivative or a phthalic acid derivative may be contained in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total repeating units.

In the above-mentioned diol component, 2-methyl-1,3-propanediol (MP), neopentyl glycol, 1,2-propanediol (1,2 -propanediol, diethylene glycol, and isosobide may be contained in an amount of 1 mol% to 10 mol% based on the total repeating units . Specifically, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2-propanediol, The repeating unit derived from diethylene glycol or isosobide may be contained in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total repeating unit%.

In the case of containing an acid component or a diol component as described above, the degree of freedom of the resin polymer can be increased to lower the melting point of the foam sheet. Thus, the foam of the resin has a low degree of crystallinity and prevents the foam sheet from hardening at the time of thermoforming can do.

For example, the melting point of the foam sheet of the present invention may be 200 ° C to 250 ° C. Specifically, the melting point of the foamed sheet may be 220 to 250 ° C or 230 to 245 ° C.

In one example, the foam sheet according to the present invention may have no crystallization peak in the range of 110 ° C to 180 ° C in a differential scanning calorimetry (DSC) analysis. Specifically, in the differential scanning calorimetry (DSC) analysis, crystallization peaks may not be present in the range of 120 ° C to 160 ° C. In the case of the conventional polyester resin foam sheet, when the heat is applied due to the crystallization peak in the range of 110 ° C to 180 ° C in the differential scanning calorimetry (DSC) analysis, the foam sheet is hardened, but the foam sheet according to the present invention controls the crystallinity Thereby forming a heat-resistant structure.

For example, the degree of crystallization of the foam sheet according to the present invention may be from 10% to 20% on average. Specifically, the degree of crystallinity of the foamed sheet may be from 12% to 17% on average, and the foamed sheet having the crystallinity in the above range may have an appropriate degree of crystallinity while being excellent in moldability.

The thickness of the foam sheet of the present invention may be 0.5 mm to 5 mm. Specifically, the thickness of the foam sheet may be 0.8 mm to 4.0 mm and 1.0 mm to 3.5 mm, and more specifically, the thickness of the foam sheet may be 1.0 mm to 4.0 mm or 1.3 mm to 3.0 mm.

In one example, the foam sheet according to the present invention can satisfy the following formula (1): " (1) "

 [Equation 1]

| V ₁ -V ₀ | / V ₀ x 100? 10%

In the above equation (1)

V ₀ is the volume (mm ³ ) of the foam sheet before exposure for 3 hours at 150 ° C,

V ₁ is the volume (mm ³ ) of the foam sheet after exposure at 150 ° C for 3 hours.

Specifically, the rate of dimensional change of the foamed sheet sample before and after the exposure at 150 캜 for 3 hours was measured. This is a measurement time in which the foam sheet corresponds to the actual use environment for heat. For example, the volume may mean a value calculated by multiplying the length of each foam sheet by the length of each of the width and thickness. For example, the rate of dimensional change according to Equation 1 may range from 0.01 to 5%, from 0.01 to 3%, or from 0.01 to 1%. By satisfying the value of the expression (1) in the above range, it can be seen that the foam sheet according to the present invention hardly undergoes morphological change even when used in a high temperature environment. As a result, it can be seen that the foam sheet according to the present invention is excellent in durability.

In one example, the foam sheet according to the present invention further comprises a resin layer formed on one or both surfaces, and the resin layer may include a polyester resin having a melting point higher than 250 캜. Specifically, it may further include a resin layer formed on one surface of the foam sheet.

For example, the resins of the resin layer may be selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene terephthalate glycoll modified (PETG), poly The polyester resin may be at least one selected from the group consisting of polylactic acid (PLA) and polyglycolic acid (PGA). Specifically, the polyester resin may be polyethylene terephthalate (PET) have.

Further, the thickness of the resin layer may be 30 탆 to 200 탆. Specifically, the thickness of the resin layer may be 40 탆 to 180 탆, 50 탆 to 150 탆, or 20 탆 to 80 탆, and more specifically, the thickness of the resin layer may be 30 탆 to 80 탆, 100 [mu] m to 150 [mu] m. By including the resin layer having such a thickness as described above, the foam sheet can be improved in heat resistance and strength, and can be formed at a sharp angle.

As one example, the foam sheet according to the present invention may have a barrier property, a hydrophilization function, or a waterproof function, and may include a surfactant, a hydrophilizing agent, a heat stabilizer, a waterproofing agent, a cell size enlarging agent, One or more functional additives selected from the group consisting of 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.

Further, according to the present invention,

Polymerizing an acid component and a diol component to prepare a polyester resin; And

And foaming the produced resin to prepare a foam sheet,

Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,

Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,

The produced polyester resin contains 80 mol% to 99 mol% of repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative with respect to the total repeating units,

(DSC) analysis does not have a crystallization peak in the range of 110 ° C to 180 ° C.

Specifically, in the step of polymerizing an acid component and a diol component to prepare a polyester resin, the acid component may necessarily contain a terephthalic acid derivative, and in some cases, a terephthalic acid derivative Or more species. In addition, the diol component may contain an ethylene glycol derivative. In some cases, 2-methyl-1,3-propanediol (MP), neopentyl glycol ), 1, 2-propanediol, diethylene glycol, and isosobide may be further included.

In one example, the produced polyester resin may contain 80 mol% to 99 mol% of repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative, based on the total repeating units. Specifically, the repeating units derived from the terephthalic acid derivative and the ethylene glycol derivative may be contained in an amount of 80 mol% to 99 mol%, 85 mol% to 99 mol%, or 90 mol% to 99 mol% based on the total repeating units. More specifically, the repeating units derived from the terephthalic acid derivative and the ethylene glycol derivative may contain 92 mol% to 99 mol% or 96 mol% to 98 mol% with respect to 100 mol% of the total repeating units. When the above-mentioned content contains repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative, the degree of crystallization of the foamed sheet can be adjusted to an appropriate range.

For example, in the acid component, the repeating unit derived from at least one member selected from the group consisting of an isophthalic acid derivative and a phthalic acid derivative may be contained in an amount of 1 mol% to 10 mol% based on the total repeating units. Specifically, the repeating unit derived from an isophthalic acid derivative or a phthalic acid derivative may be contained in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total repeating units.

In the above-mentioned diol component, 2-methyl-1,3-propanediol (MP), neopentyl glycol, 1,2-propanediol (1,2 -propanediol, diethylene glycol, and isosobide may be contained in an amount of 1 mol% to 10 mol% based on the total repeating units . Specifically, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2-propanediol, The repeating unit derived from diethylene glycol or isosobide may be contained in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total repeating units.

When an acid component or a diol component is included as described above, the degree of freedom of the resin can be increased to lower the melting point of the foam sheet. Accordingly, the foam sheet has a low degree of crystallization, and the foam sheet can be prevented from hardening at the time of thermoforming have.

In one example, the step of producing a polyester resin may be carried out by mixing an isophthalic acid derivative or a phthalic acid derivative in an acid component at a ratio of 1 mol% to 10 mol% with respect to the total of the acid component and the diol component. Specifically, an isophthalic acid derivative or a phthalic acid derivative in an acid component may be mixed in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total amount of the acid component and the diol component.

In addition, the step of preparing the polyester resin may be carried out in the diol component using 2-methyl-1,3-propanediol (MP), neopentyl glycol, 1,2-propanediol 1,2-propanediol, diethylene glycol or isosobide can be mixed in an amount of 1 mol% to 10 mol% based on the total amount of the acid component and the diol component. Specifically, in the diol component, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2-propanediol (1,2- propanediol, diethylene glycol or isosobide may be mixed in an amount of 1 mol% to 8 mol% or 2 mol% to 4 mol% based on the total amount of the acid component and the diol component.

In one example, the step of producing the foam sheet may include a foaming process of foaming the polyester resin to produce a foam. The foaming process can be performed using various types of extruders. The foaming process can be largely carried out through bead foaming or extrusion foaming, and extrusion foaming is preferred. The extrusion foaming can simplify the process steps by continuously extruding and foaming the resin melt, and can be mass-produced. It prevents cracks and granular fracture between the beads at the time of bead foaming, And compressive strength can be realized.

For example, in the step of producing the foam sheet, the foam sheet may be formed to a thickness of 0.5 mm to 5 mm. Specifically, the foam sheet may be formed to a thickness of 0.8 mm to 4.0 mm and 1.0 mm to 3.5 mm, and more specifically, the foam sheet may be formed to a thickness of 1.0 mm to 4.0 mm or 1.3 mm to 3.0 mm .

As one example, the step of producing the foam sheet according to the present invention may be carried out in various types of additives. The additive may be injected into the fluid connection line, or may be injected during the foaming process, if necessary. Examples of the additive may include a barrier property, a hydrophilization function or a waterproof function, and may be selected from the group consisting of a thickener, a surfactant, a hydrophilizing agent, a heat stabilizer, a waterproofing agent, a cell size expanding agent, an infrared attenuator, a plasticizer, At least one functional additive selected from the group consisting of a pigment, an elastic polymer, an extrusion aid, an antioxidant, a nucleating agent, an antistatic agent, and a UV absorber. Specifically, the method for manufacturing a foam of the present invention may contain at least one of a thickener, a nucleating agent, a heat stabilizer and a foaming agent, and may further include at least one of the above-mentioned functional additives.

For example, the step of preparing the foam sheet of the present invention can be carried out by using a thickener, a hydrophilizing agent, a heat stabilizer, a waterproofing agent, a cell size enlarging agent, an infrared attenuator, a plasticizer, a fire retardant chemical, a pigment, an elastic polymer, One or more additives selected from the group consisting of a nucleating agent, an anti-static agent, and a UV absorber may be introduced into the fluid connection line. Of the additives required in the production of the foam, the additives which have not been introduced into the fluid connection line can be put in the extrusion process.

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 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.

In one example, the method for producing a foam sheet according to the present invention may further comprise the step of forming a resin layer on one side or both sides of the foam sheet after the step of producing the foam sheet. Specifically, the resin layer may be formed on one side of the foam sheet using a polyester resin having a melting point higher than 250 ° C, and the resin layer may be a polyethylene terephthalate (PET), a polybutylene Polybutylene terephthalate (PBT), polyethylene terephthalate glycoll modified (PETG), polylactic acid (PLA) and polyglycolic acid (PGA). And more specifically, the polyester resin may be polyethylene terephthalate (PET) resin.

Specifically, in the step of forming the resin layer, the polyester resin may be melted using an extruded T-die before winding the foam sheet, and the resin layer may be formed by coating the foam sheet on one side or both sides thereof.

For example, the resin layer may be formed to a thickness of 30 to 200 탆. Specifically, the resin fiber layer may be formed to a thickness of 40 탆 to 180 탆, 50 탆 to 150 탆, or 20 탆 to 80 탆, and more specifically, the resin layer may have a thickness of 30 탆 to 80 탆, And can be formed to a thickness of 100 mu m to 150 mu m. By forming the resin layer as described above, the produced foam sheet can be improved in heat resistance and strength, and can be formed at a sharp angle.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.

Example 1

Terephthalic acid and ethylene glycol were added to the ester reaction tank, and a typical polymerization reaction was carried out at 258 ° C to prepare a polyethylene terephthalate polymer (PET oligomer) having a reaction rate of about 96%. 2-methyl-1,3-propanediol (MPD) was mixed with the prepared polyethylene terephthalate (PET) in an amount ratio of 2 mol%, and an esterification reaction catalyst was added to carry out an esterification reaction at 250 占 2 占Respectively. Then, a condensation polymerization catalyst was added to the obtained reaction mixture, and the condensation polymerization reaction was carried out while controlling the final temperature and pressure in the reaction vessel to be 280 ± 2 ° C. and 0.1 mmHg, respectively, to prepare a copolymer polyester resin.

0.5 part by weight of pyromellitic dianhydride, 0.5 part by weight of talc, and 0.1 part by weight of Irganox (IRG 1010) were mixed with 100 parts by weight of the polyester resin, and heated at 280 degrees to prepare a resin melt. Then, 3 parts by weight of butane as a foaming agent was added to the first extruder based on 100 parts by weight of PET resin, and extrusion foaming was carried out to form a foam layer having a thickness of 2 mm to prepare a polyester resin foam sheet.

Example 2

A foam sheet was prepared in the same manner as in Example 1, except that 2-methyl-1,3-propanediol (MPD) was mixed at a content ratio of 8 mol%.

Comparative Example 1

A foam sheet was prepared in the same manner as in Example 1, except that 2-methyl-1,3-propanediol (MPD) was not mixed.

Comparative Example 2

A foam sheet was prepared in the same manner as in Example 1, except that 2-methyl-1,3-propanediol (MPD) was mixed in a proportion of 30 mol%.

Experimental Example 1

In order to confirm the physical properties of the foam sheet according to the present invention, the foam sheets prepared in Example 1 and Comparative Example 1 were analyzed using a thermal differential scanning calorimeter (DSC-7, Perkin Elmer) 1.

In addition, the foam sheets were dissolved in a concentration of 0.5 wt% in each of the solutions of phenol and tetrachloroethane in a weight ratio of 1: 1 for Example 1, Example 2, Comparative Example 1 and Comparative Example 2 The intrinsic viscosity (IV) was measured at 35 캜 using a Ube load viscometer.

Further, in order to confirm the thermoformability of the foam sheet according to the present invention, the foam sheet was heated to 200 ° C or higher in Examples 1, 2, and Comparative Example 1, and then subjected to heat treatment using male and female molds The thermoformability was measured by molding. The results are shown in Table 1 below.

Fig. 1 is a graph showing the results of analysis by the differential scanning calorimetry method for Example 1 and Comparative Example 1. Fig. Referring to FIG. 1, the foam sheet of Comparative Example 1 shows a crystallization peak in a range of 110 ° C to 180 ° C. In addition, it can be confirmed that the crystallization peak does not appear in the foam sheet of Example 1 in the range of 110 ° C to 180 ° C. This means that even when heat is applied to the foam sheet according to the present invention, the degree of crystallinity is not appropriately controlled and hardened.

As shown in Table 1, the foam sheet of the present invention (Examples 1 to 3) was not damaged even after the thermoforming process, whereas the foam sheet of Comparative Example 1 was foamed in the mold in the thermoforming process It can be confirmed that the sheet is torn. This indicates that the foam sheet of the present invention has a low degree of crystallinity and is not hardened even in a molding process for applying heat, whereas in the case of Comparative Example 1, the foam sheet is hardened when heat is applied and is torn in the mold.

Claims (10)

As a foam of a polyester resin,
In the foamed state, it comprises repeating units derived from an acid component and a diol component,
Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,
Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,
The repeating unit derived from the terephthalic acid derivative and the ethylene glycol derivative is contained in an amount of 80 mol% to 99 mol% based on the total repeating units,
Characterized in that it does not have a crystallization peak in a range of 110 ° C to 180 ° C in a differential scanning calorimetry (DSC) analysis.
The method according to claim 1,
Wherein the repeating unit derived from at least one member selected from the group consisting of isophthalic acid derivatives and phthalic acid derivatives in the acid component is contained in an amount of 1 mol% to 10 mol% based on the total repeating units.
The method according to claim 1,
In the diol component, 2-methyl-1,3-propanediol (MP), neopentyl glycol, 1,2-propanediol ), Diethylene glycol, and isosobide is contained in an amount of 1 mol% to 10 mol% based on the total repeating units. Foam sheet.
The method according to claim 1,
Wherein the foam sheet has a melting point of 200 ° C to 250 ° C.
The method according to claim 1,
Wherein the foam sheet further comprises a resin fiber layer formed on one side or both sides,
Wherein the fibers forming the fibrous layer are partially fused with each other.
The method according to claim 1,
The foam sheet further includes a resin layer formed on one surface or both surfaces thereof,
Wherein the resin layer comprises a polyester resin having a melting point higher than 250 ° C.
Polymerizing an acid component and a diol component to prepare a polyester resin; And
And foaming the produced resin to prepare a foam sheet,
Wherein the acid component is at least one member selected from the group consisting of terephthalic acid derivatives, isophthalic acid derivatives and phthalic acid derivatives,
Wherein the diol component is selected from the group consisting of ethylene glycol derivatives, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2- 2-propanediol, diethylene glycol, and isosobide, and more preferably,
The produced polyester resin contains 80 mol% to 99 mol% of repeating units derived from a terephthalic acid derivative and an ethylene glycol derivative with respect to the total repeating units,
Characterized in that it does not have a crystallization peak in the range of 110 ° C to 180 ° C in the differential scanning calorimetry (DSC) analysis.
8. The method of claim 7,
In the acid component, the mixing amount of the isophthalic acid derivative or the phthalic acid derivative is 1 mol% to 10 mol% with respect to the total of the acid component and the diol component.
8. The method of claim 7,
In the diol component, 2-methyl-1,3-propanediol, MP, neopentyl glycol, 1,2-propanediol, , Diethylene glycol or isosobide is 1 mol% to 10 mol% with respect to the total amount of the acid component and the diol component.
8. The method of claim 7,
After the step of producing the foam sheet,
And forming a resin layer on one side or both sides of the foam sheet.

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