KR102658068B1 - Thermoplastic polyester resin composition and polyester resin prepared from the composition - Google Patents

Abstract

The present invention relates to a thermoplastic polyester resin composition and a polyester resin prepared therefrom. The polyester resin composition of the present invention includes an appropriate amount of 1,4-cyclohexanedimethanol and polyether polyol, and the resin composition By adjusting the acid and alcohol components to a specific ratio, it is possible to provide a polyester elastomer resin with the desired crystallinity. Furthermore, the polyester resin exhibits appropriate crystallinity, so that it does not cause fusion or deformation of the pellets during processing and molding into pellets, and can simultaneously satisfy mechanical properties and transparency.

Description

Thermoplastic polyester resin composition and polyester resin prepared therefrom

The present invention relates to a thermoplastic polyester resin composition and a polyester resin manufactured therefrom, and more specifically, to a thermoplastic polyester resin composition capable of providing an elastomer resin that is free from heat fusion during processing and molding and can realize high transparency. It's about.

In general, polymer materials with elasticity and low hardness are used in various fields such as cable and hose industrial products, electronic products such as smart bands, mobile phones, and earphones, shoe foam, and sports leisure products such as elastic monofiller fibers. .

Conventionally, a transparent elastic material with low hardness includes polyvinyl chloride (PVC). However, PVC material itself causes environmental pollution, and although a transparent polymer (or product) can be obtained by using a plasticizer, defects such as blooming of the plasticizer on the surface of the product may occur.

For example, Korean Patent Publication No. 2000-0007680 discloses a transparent PVC plastic film manufactured using PVC and a plasticizer, but defects may occur in which the plasticizer is exposed on the film surface, and harmful gases are generated when waste is incinerated. There is a downside to this.

Accordingly, engineering elastomer materials such as thermoplastic polyurethane (TPU), thermoplastic polyamide ester, and thermoplastic polyester elastomer (TPEE) are widely used, but all of them have poor plasticizer expression or time lapse. There is a yellowing problem due to.

For example, Korean Patent Publication No. 2000-0060104 discloses a transparent mouse pad and attempted to make a transparent polymer by mixing PCV, TPU, TPEE, and rubber as materials with a plasticizer. However, in the case of TPEE, it is mixed with a general plasticizer. When injection molded products are used, there is a problem that plasticizers are expressed on the outside of the molded product after a certain period of time, and in the case of TPU, there is a problem that yellowing occurs over time. In addition, Korean Patent Publication No. 2007-0058080, while disclosing a transparent thermoplastic elastomer composition, still failed to solve the problem of plasticizer expression by using a mixture of polyester elastomer and a non-phthalate plasticizer.

TPEE, an engineering elastomer material that has recently been in the spotlight, refers to a block copolymer of a soft segment (SS) and a hard segment (HS). The crystallinity and transparency of the resin vary depending on the type and content of the monomers that make up TPEE. .

In TPEE, the soft segment refers to a polyester resin with an ester bond structure resulting from a polycondensation reaction between a polyol component with a long chain structure and a dibasic acid, and the hard segment refers to a polyester resin with a polycondensation reaction between an aliphatic diol component and a dibasic acid. Refers to a polyester resin having an ester bond structure.

Conventionally, polyesters with higher crystallinity such as polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN) were used as hard segments, and polyoxyalkylene glycols and polycaprolactone (PCL) were used as soft segments. , polyester with lower crystallinity, such as polybutylene adipate (PBA), was used.

However, polyester elastomer resins manufactured using PBT and/or PBN as hard segments have the disadvantage of being opaque due to their high crystallinity. Polyethylene terephthalate (PET), which has lower crystallinity than PBT and PBN, may be presented as a soft segment component, but PET includes polyoxyalkylene glycols, polycaprolactone (PCL), polybutylene adipate (PBA), etc. When polyester is introduced as a soft segment component, crystallinity increases and the desired transparency cannot be obtained. This is because the soft segment component maximizes the movement of the polymer chain of the hard segment component and increases the crystallization rate (see Non-Patent Documents 1 and 2).

TPEE, which is widely used as an engineering elastomer, has limitations in producing a transparent resin with the desired crystallinity simply by selecting and mixing conventionally known raw materials (=monomers).

Korean Patent Publication No. 2000-0007680 Korean Patent Publication No. 2000-0060104 Korean Patent Publication No. 2007-0058080

J. APPL. POLYM. SCI. 2015, DOI: 10.1002/APP.42066 Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters, Page 495

Therefore, in order to improve the problems described above, the present invention provides a transparent TPEE resin with semi-crystallinity by controlling the type and/or content of the monomer components that make up the resin while maintaining the physical properties of the TPEE resin. I want to do it.

In order to achieve the above object, the present invention provides (a) an acid component containing an aromatic dicarboxylic acid; and (b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. an alcohol component containing; and containing the 1,4-cyclohexanedimethanol and polyether polyol in amounts of 2 to 40% by weight and 16 to 54% by weight, respectively, based on the total weight of the alcohol component. An ester resin composition is provided.

In order to achieve the above other objects, the present invention provides a polyester resin derived from the above polyester resin composition and having a haze of 10% or less when manufactured into a 2 mm thick sheet.

In order to achieve the above further object, the present invention provides (1) (a) an acid component containing an aromatic dicarboxylic acid; and (b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. Esterifying or transesterifying a polyester resin composition containing an alcohol component in the presence of a titanium-based catalyst; and (2) subjecting the reaction product of step (1) to a polycondensation reaction, wherein in step (1), the total weight of the alcohol component is adjusted to 1,4-cyclohexanedimethanol and polyether polyol, respectively. A method for producing a polyester resin is provided, which is used in an amount of 2 to 40% by weight and 16 to 54% by weight as a standard.

The polyester resin composition of the present invention contains an appropriate amount of 1,4-cyclohexanedimethanol and polyether polyol, and adjusts the acid and alcohol components in the resin composition to a specific ratio to produce a polyester elastomer with desired crystallinity. Resin can be provided. Furthermore, the polyester resin exhibits appropriate crystallinity and does not cause fusion or deformation of pellets when processed and molded into pellets, and can simultaneously satisfy mechanical properties and transparency, so it can be used as various molding materials including fibers, films, and sheets. For example, it can be useful as a molding material for elastic yarn, cosmetic containers, mobile phone jelly cases, molded products for teeth whitening, boots, gears, tubes, packing, and wire covering materials.

The present invention is not limited to the content disclosed below, and may be modified into various forms as long as the gist of the invention is not changed.

In this specification, “includes” means that other components may be further included unless otherwise specified.

All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification should be understood as modified by the term “about” in all cases unless otherwise specified.

polyester resin composition

The present invention provides (a) an acid component containing an aromatic dicarboxylic acid; and (b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. an alcohol component containing; and containing the 1,4-cyclohexanedimethanol and polyether polyol in amounts of 2 to 40% by weight and 16 to 54% by weight, respectively, based on the total weight of the alcohol component. An ester resin composition is provided.

(a) acid component

The polyester resin composition of the present invention contains aromatic dicarboxylic acid as the acid component (a), and in addition to aliphatic dicarboxylic acids, cycloaliphatic dicarboxylic acid, aliphatic dicarboxylic acid, alkyl esters thereof, acid anhydrides, and trivalent dicarboxylic acids. It may further include one or more types selected from the group consisting of the above polyacidic components.

The aromatic dicarboxylic acid may include aromatic dicarboxylic acid, its alkyl ester, and its acid anhydride that are commonly used in the production of polyester resin.

Specifically, the aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, dimethyl terephthalate, naphthalene dicarboxylic acid, dimethyl isophthalate, diethyl terephthalate, dimethyl naphthalate, diethyl isophthalate, dibutyl terephthalate, and dibutyl isophthalate. , 5-sulfoisophthalate sodium salt, and dimethyl 5-sulfoisophthalate sodium salt.

Since the aromatic dicarboxylic acid contains a highly hydrophobic benzene ring, it can improve the moisture resistance of the resin obtained from the polyester resin composition and improve the heat resistance stability of the resin by increasing the melting point (Tm) of the resin.

The aromatic dicarboxylic acid may be included in an amount of 70 to 100% by weight, 80 to 100% by weight, 90 to 100% by weight, or 95 to 100% by weight based on the total weight of the acid components.

Specifically, the aliphatic dicarboxylic acid may be an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dimer acid, hydrogenated dimer acid, etc. . The aliphatic dicarboxylic acid may be used in a range that does not significantly lower the melting point of the resin, for example, less than 30% by weight, less than 20% by weight, or less than 10% by weight based on the total weight of the acid component (a).

(b) alcohol content

The polyester resin composition of the present invention is an alcohol component (b) from the group consisting of (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polypropylene glycol and polytetramethylene glycol. It includes a polyether polyol containing one or more selected species.

(b-1) ethylene glycol and 1,4- Cyclohexanedimethanol

The alcohol component (b) is an aliphatic diol and includes ethylene glycol and 1,4-cyclohexanedimethanol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1, It may further include aliphatic diols such as 5-pentanediol and 1,6-hexanediol.

The 1,4-cyclohexanedimethanol is introduced into the main chain produced during polyester resin production, allowing the polyester resin to have semi-crystallinity.

In particular, the residue derived from 1,4-cyclohexanedimethanol can lower the regularity of the polymer chain in the polyester resin and reduce the crystallization rate of the resin during the polycondensation reaction, thereby increasing the transparency of the polyester resin. .

The 1,4-cyclohexanedimethanol is 2 to 40% by weight, 3 to 40% by weight, 3 to 35% by weight, 5 to 40% by weight, or 5 to 32% by weight based on the total weight of the alcohol component (b). It can be included in an amount of, and when it is within the above range, a transparent polyester elastomer resin with semi-crystallinity can be obtained by maintaining an appropriate level of crystallization rate.

The ethylene glycol may be included in an amount of 20 to 70% by weight, 25 to 70% by weight, 30 to 70% by weight, or 30 to 65% by weight based on the total weight of the alcohol component (b).

If it is contained in excess of the above range, the transparency of the polyester resin can be secured, but the crystallization rate may be too low, which may deteriorate the mechanical properties, and problems such as heat fusion of the pellets may occur when processing or molding into pellets. Therefore, molding such as stretching, injection, and extrusion is impossible. In addition, if it is included in a small amount than the above range, the crystallization rate becomes faster, so a transparent polyester resin cannot be obtained and it cannot have the physical properties (e.g. elasticity) of an elastomer resin.

The ethylene glycol and 1,4-cyclohexanedimethanol react with the acid component (a) to form hard segments in the polyester resin.

(b-2) polypropylene glycol and Polytetramethylene glycol Polyether polyol containing at least one selected from the group consisting of

The alcohol component (b) includes a polyether polyol (b-2) containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. The polyether polyol can be produced by adding propylene oxide or ethylene oxide to an initiator having two or more activated hydrogens such as OH or -NH ₂ .

The polyether polyol (b-2) is 16 to 54% by weight, 16 to 53% by weight, 16 to 52% by weight, 16 to 51% by weight, 16 to 50% by weight, or It may be included in an amount of 17 to 50% by weight.

The polyether polyol (b-2) may have a number average molecular weight of 500 to 3,000 g/mol or 600 to 3,000 g/mol. When it is within the above range, a transparent polyester elastomer resin can be obtained while maintaining appropriate elasticity. If it is outside the above range, the physical properties and processability of the resin may deteriorate.

In addition, the polyester resin composition may further include polyol components such as polycaprolactone and polybutylene adipate within the range that does not impair the transparency of the resin. Specifically, the total weight of the alcohol component (b) is It may be included in an amount of 30% by weight or less, 10 to 30% by weight, or 10 to 20% by weight.

The polyol components react with the acid component (a) described above to form soft segments in the polyester resin.

The resin composition may further include a branching agent including a trifunctional or higher polycarboxylic acid, a trifunctional or higher polyol, or a mixture thereof. Examples of branching agents include trimellitic anhydride, benzophenone tetracarboxylic acid, trimethylolpropane, and glycerin. The branching agent may be included in an amount of 0.01 to 1 part by weight, or 0.03 to 1 part by weight, based on 100 parts by weight of the acid component (a) or alcohol component (b).

polyester resin

The present invention provides a polyester resin (thermoplastic polyester elastomer resin; TPEE resin) derived from the above polyester resin composition and having a haze of 10% or less when manufactured into a 2 mm thick sheet.

As described above, the TPEE resin has a hard segment and a soft segment in the structure by reacting the acid component (a) and the alcohol component (b).

Specifically, the TPEE resin includes a hard segment obtained by reacting an acid component (a) containing an aromatic dicarboxylic acid with ethylene glycol and 1,4-cyclohexanedimethanol (b-1), and the aromatic dicarboxylic acid. It includes a soft segment obtained by reacting the acid component (a) with the polyether polyol (b-2).

At this time, the TPEE resin does not have a structure in which hard segments and soft segments are combined with a chain extender such as isocyanate, glycidyl, or epoxy compound, but the units constituting the hard segment and/or soft segment (monomers of the resin composition) It is in a direct ester bonded state.

The polyether polyol (b-2) may be included in an amount of 9 to 34% by weight, 10 to 34% by weight, or 10 to 33% by weight based on the total weight of the polyester resin. When within the above range, TPEE resin can satisfy an appropriate level of mechanical properties. For example, the TPEE resin may have a hardness of 20 to 82 shore D, 20 to 75 shore D, 20 to 70 shore D, 20 to 65 shore D, 20 to 60 shore D, or 20 to 50 shore D.

In addition, the TPEE resin may have a melting point of 180 to 225°C, or 185 to 220°C, and a heat of fusion (ΔH _f ) of 5 to 40 J/g, or 5 to 35 J/g. In addition, the TPEE resin may have an intrinsic viscosity (IV) of 0.7 to 1.1 dl/g, or 0.8 to 1.1 dl/g, and a Color-b (yellowness index) according to ASTM D-1925 of 4 or less or 3.5 or less. . When within the above range, the TPEE resin can have high transparency while maintaining excellent mechanical properties.

Furthermore, the TPEE resin may have a melt flow index (MI) of 3 to 30 g/10 min, 4 to 20 g/10 min, or 5 to 20 g/10 min. When it is within the above range, it has an appropriate viscosity and is easy to process and mold, and the TPEE resin can have excellent elastic recovery and mechanical strength. Furthermore, when the TPEE resin is manufactured into pellets, fusion does not occur between pellets at a temperature of 40°C or higher, so not only is the processability excellent, but it can be stored for a long time without deformation even at high temperatures.

In addition, the polyester resin of the present invention contains one or more additives such as processing aids, electrostatic applicators, ultraviolet absorbers, heat stabilizers, antistatic agents, pigments, flame retardants, thickeners, nucleating agents, slip agents, and anti-blocking agents. It can be included only to the extent that transparency is not lost.

Manufacturing method of polyester resin

The present invention relates to (1) (a) an acid component containing an aromatic dicarboxylic acid; and (b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. Esterifying or transesterifying a polyester resin composition containing an alcohol component in the presence of a titanium-based catalyst; and (2) subjecting the reaction product of step (1) to a polycondensation reaction, wherein in step (1), the total weight of the alcohol component is adjusted to 1,4-cyclohexanedimethanol and polyether polyol, respectively. A method for producing a polyester (TPEE) resin is provided, which is used in an amount of 2 to 40% by weight and 16 to 54% by weight as a standard.

Step (1): esterification or transesterification reaction

First, in step (1), the monomers described above, specifically the acid component (a) and the alcohol component (b), are esterified or transesterified.

The 1,4-cyclohexanedimethanol and polyether polyol may be used in amounts of 2 to 40% by weight and 16 to 54% by weight, respectively, based on the total weight of the alcohol component.

At this time, the weight ratio of the alcohol component (b) to the acid component (a) may be 1.2 to 1.8, or 1.4 to 1.6. When within the above range, the polymerization rate can be maintained appropriately in the subsequent polycondensation reaction (step (2) below), and a TPEE resin with excellent mechanical properties and transparency can be produced. If the weight ratio is less than 1.2, unreacted acid components may remain after the polycondensation reaction, which may reduce the mechanical properties of the TPEE resin, and if it exceeds 1.8, the polycondensation reaction speed is slowed, which is disadvantageous in terms of productivity.

The esterification reaction or transesterification reaction is tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, ethyl acetoacetic ester titanate, isostearyl titanate, titanium It can be performed in the presence of a titanium-based catalyst such as dioxide, TiO ₂ /SiO ₂ coprecipitant, and TiO ₂ /ZrO ₂ coprecipitant, and it is preferable not to use heavy metal antimony-based or tin-based catalysts from an environmental standpoint.

The esterification reaction or transesterification reaction can be performed, for example, by removing water or alcohol generated from the reactants by a conventional method while melting and mixing the reaction mixture at a reaction temperature of 180 to 220° C. under a nitrogen stream.

The esterification reaction or transesterification reaction may be performed by further adding a branching agent containing a trifunctional or higher polycarboxylic acid, a trifunctional or higher polyol, or a mixture thereof, and the type and content of the branching agent are as described above.

Step (2): polycondensation reaction

When the esterification reaction or transesterification reaction is completed, a polycondensation reaction is performed.

Step (2) can be performed under typical polycondensation reaction conditions of polyester resin.

Specifically, in step (2), the reactants of step (1) are (a) stirred at low speed in low vacuum at a temperature of 250°C or lower, 240°C or lower or 210 to 250°C, and (b) then stirred at high speed in high vacuum. While stirring, (c) maintaining the reactor at high vacuum, the reactants can be reacted under low-speed stirring to produce a TPEE resin with a desired degree of polymerization.

By-products such as glycol generated in the reaction are distilled off, and step (b) may be performed under reduced pressure conditions (high vacuum) of 0.01 to 400 mmHg, 0.05 to 100 mmHg, or 0.1 to 10 mmHg. When within the reduced pressure range of 0.01 to 400 mmHg, low boiling point compounds generated during the polycondensation reaction can be removed from the reaction system.

Prior to step (2), it is desirable to treat (deactivate) the remaining catalyst in the reactants (molten mixed state) after step (1) to prevent it from being activated.

If the catalyst remains in the reactant of step (1), the esterification or transesterification reaction may proceed further, increasing the yellowness of the TPEE resin and reducing transparency. In addition, even during molding such as compounding, esterification or transesterification reaction may proceed further and affect the physical properties of the TPEE resin.

Therefore, before performing the polycondensation reaction in step (2), a material containing a phosphorus (P) component may be added to suppress the activity of the metal component of the catalyst.

Examples of substances containing the phosphorus component include phosphorous acid, phosphoric acid, triphenyl phosphate, tristriethylene glycol phosphate, orthophosphoric acid, triphenyl phosphite, trimethyl phosphate, and trimethyl phosphite.

The polycondensation reaction of step (2) may be performed by further adding a phosphorus (P)-based antioxidant, a cobalt acetate-based colorant, or both.

Representative phosphorus-based antioxidants include, for example, the reaction product of phosphorus trichloride with 1,1-biphenyl and 2,4-t-butylphenol, sodium phenyl phosphonate, and 2,4-di-tert-butyl phenyl. Phosphites, aryl phosphonites, and mixtures thereof may be included.

Commercially available products of the phosphorus-based antioxidant include biphenyl-based di-tert-butyl phenyl phosphorus produced by the condensation reaction of phosphorus trichloride and the Friedel Kraft adduct of biphenyl and 2,4-di-tert-butyl phenol. A nite mixture, PEPQ (Clairant Co.), is known.

The content of the phosphorus-based antioxidant may be 100 to 1,500 ppm, or 300 to 1,000 ppm, based on the total weight of the TPEE resin composition.

When within the above range, the increase in yellowness caused by the catalyst remaining in the composition can be effectively suppressed.

Furthermore, in order to further suppress the increase in yellowness of the TPEE resin, a small amount of cobalt acetate may be added as a colorant in step (2). At this time, the content of cobalt (Co) may be 0.1 to 500 ppm, 0.1 to 300 ppm, 10 to 200 ppm, 10 to 300 ppm, 100 to 300 ppm, or 100 to 200 ppm based on the total weight of the TPEE resin composition. .

As described above, the polyester resin composition of the present invention contains an appropriate amount of 1,4-cyclohexanedimethanol and polyether polyol, and achieves the desired crystallinity by adjusting the acid component and alcohol component in the resin composition to a specific ratio. A polyester elastomer resin having can be provided. Furthermore, the polyester resin exhibits appropriate crystallinity and does not cause fusion or deformation of pellets when processed and molded into pellets, and can simultaneously satisfy mechanical properties and transparency, so it can be used as various molding materials including fibers, films, and sheets. For example, it can be useful as a molding material for elastic yarn, cosmetic containers, mobile phone jelly cases, molded products for teeth whitening, boots, gears, tubes, packing, and wire covering materials.

The above will be explained in more detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited to these only.

[ Example ]

In the following examples and comparative examples, the compounds shown in Table 1 below were used.

Example 1. Production of polyester resin

In a reactor equipped with a stirrer and an effluent condenser, 95.7% by weight of DMT and 4.3% by weight of IPA based on the total weight of acid components, 46.5% by weight of EG, 16.0% by weight of CHDM, 36.9% by weight of PTMG 650 and 36.9% by weight of PTMG 650 based on the total weight of alcohol components. 0.6% by weight of TMP was added, and TiO ₂ /SiO ₂ coprecipitant as a catalyst was charged to 100 ppm based on the acid component.

At this time, the ratio of the alcohol component to the acid component (alcohol component (b)/acid component (a) = G/A) was set to 1.6.

An esterification reaction was performed while gradually raising the temperature of the reactor to 220°C under a nitrogen stream and simultaneously discharging by-products, methanol and water, to the outside of the reactor. After the generation and discharge of methanol is completed, the reactant is transferred to a polycondensation reactor equipped with a stirrer, cooling condenser, and vacuum system, and 1,000 ppm of Igaphos 168 as an antioxidant and as a colorant based on the total weight of the polyester resin composition. 300 ppm of cobalt(II) acetate was added.

Then, the reaction temperature was raised to 240°C, the reaction pressure was reduced to 50 mmHg over 30 minutes, and the reaction was carried out under low vacuum, while excess diol component was distilled out. Next, the reaction pressure was gradually reduced to 0.1 mmHg and the reaction was performed under high vacuum until a predetermined stirring torque was reached, and then the reaction was terminated. After polymerizing the polyester resin, polyester pellets are manufactured through a pelletizing step, and then subjected to a dehumidifying dryer drying process at a temperature of 80 to 90°C for 4 hours to obtain a transparent polyester resin (polyester elastomer resin). did.

Example 2 to 13 and Comparative example 1 to 9. Preparation of polyester resin

A polyester resin was prepared in the same manner as in Example 1, except that the type and content of the acid component and/or alcohol component were different as shown in Table 2 below.

[ Evaluation example ]

The polyester resins prepared in Examples 1 to 13 and Comparative Examples 1 to 9 were quantitatively analyzed and evaluated for physical properties in the following manner. The results are shown in Table 3.

(1) Calculation of polyol content in polyester resin - quantitative analysis

To determine the polyol content in the polyester resin, a 600Mhz nuclear magnetic resonance (NMR) spectrometer was used to quantitatively analyze PTMG, PPG, EO-PPG, or PEG components in the entire polyester resin.

(2) Blocking resistance

The appearance of the polyester resin pellets that had completed the drying process at a temperature of 80 to 90° C. was examined and evaluated as follows.

Ⅹ: Deformation of pellet shape, such as a caking shape due to fusion of pellets together, or occurrence of coarse material

△: Fusion phenomenon occurs in part of the pellet

○: There is no deformation in the appearance of the pellets, and the pellets do not fuse together.

(3) Intrinsic viscosity (IV)

For each polyester resin, 0.25 g was dissolved in 25 ml of mixed solvent (phenol/tetrachloroethane = 60/40 weight ratio), and then the intrinsic viscosity was measured using an Oswald viscometer at 30°C.

(4) melt flow Index (MI, g/10 min)

For each polyester resin, the melt index was measured at 230°C and a load of 2.16 kg according to ASTM D 1238.

(5) Hardness

For each polyester resin, the hardness was measured using Shore D type according to ASTM D 2240.

(6) Melting point ( Tm , ℃) and heat of fusion (ΔH _f, J/g)

Each polyester resin was tested as follows.

Using a differential scanning calorimeter (TA Instruments), a polyester resin dried under reduced pressure at 50°C for 15 hours was melted and quenched, and then the temperature was raised at 10°C/min for measurement. The maximum point of the endothermic peak due to resin melting was set as the melting point (Tm), and the heat of fusion (ΔH _f ) was calculated by calculating the area of this melting point peak.

(7) Yellowness (color-b)

For each polyester resin, the yellowness index was evaluated according to ASTM D-1925.

(8) Transmittance ( TT , % ) and Haze (Haze, % )

Each polyester resin was formed into a sheet with a thickness of 2 mm according to the method of ASTM D1003, and the total transmittance (TT) and haze of the sheet were measured.

Looking at Table 3 above, it can be seen that the polyester resins of Examples 1 to 13 did not cause heat fusion or deformation between pellets even after the drying process, and no impurities such as coarse materials were generated, showing excellent blocking resistance. In addition, the polyester resins of the examples exhibit appropriate levels of melting point and heat of fusion corresponding to the present invention, and are significantly different from the polyester resins prepared in Comparative Examples 1 to 9 in terms of transparency such as yellowness, transmittance, and haze. It showed excellent results.

On the other hand, in the case of Comparative Examples 1 and 2, which did not use CHDM or contained less than 2% by weight of CHDM, the heat of fusion exceeded 40 J/g and crystallinity increased, so blocking resistance was improved, but transparency was low. In addition, in the case of Comparative Examples 3, 4, and 9 in which CHDM was used in excess of 40% by weight, the heat of fusion was less than 5 J/g and crystallinity was low, so transparency was excellent, but blocking resistance was not satisfied.

In addition, Comparative Examples 5 and 6 (X including PTMG) using EO-PPG and PEG had too high a heat of fusion to obtain a transparent polyester resin.

In addition, Comparative Example 7, in which the polyol content of the soft segment in the polyester resin is less than 9% by weight, has too high hardness and lacks elasticity as an elastomer, and Comparative Example 8, which contains 35% by weight of polyol, has too low hardness, resulting in blocking resistance. Performance was low.

Claims (14)

Derived from a polyester resin composition,
A polyester resin having a haze of 10% or less and a heat of fusion of 10.6 to 40 J/g when manufactured into a 2 mm thick sheet,
The polyester resin composition,
(a) an acid component containing an aromatic dicarboxylic acid; and
(b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. Contains an alcohol component,
The 1,4-cyclohexanedimethanol and polyether polyol are included in amounts of 2 to 40% by weight and 16 to 54% by weight, respectively, based on the total weight of the alcohol component,
A polyester resin comprising the ethylene glycol in an amount of 42.1 to 58.8% by weight based on the total weight of the alcohol component. According to paragraph 1,
The aromatic dicarboxylic acid is terephthalic acid, isophthalic acid, dimethyl terephthalate, naphthalene dicarboxylic acid, dimethyl isophthalate, diethyl terephthalate, dimethyl naphthalate, diethyl isophthalate, dibutyl terephthalate, dibutyl isophthalate, 5- A polyester resin, which is at least one selected from the group consisting of sodium salt of sulfoisophthalate and sodium salt of dimethyl 5-sulfoisophthalate. According to paragraph 1,
A polyester resin wherein the polyether polyol has a number average molecular weight of 600 to 3,000 g/mol. According to paragraph 1,
A polyester resin, wherein the resin composition further includes 0.01 to 1 part by weight of a branching agent based on 100 parts by weight of the acid component or alcohol component. According to paragraph 4,
A polyester resin wherein the branching agent includes a trifunctional or higher polycarboxylic acid, a trifunctional or higher polyol, or a mixture thereof. delete According to paragraph 1,
A polyester resin having a melting point (Tm) of 180 to 225°C. According to paragraph 1,
The polyester resin has an intrinsic viscosity (IV) of 0.7 to 1.1 dl/g and a Color-b (yellowness index) according to ASTM D-1925 of 4 or less. According to paragraph 1,
A polyester resin having a hardness of 20 to 82 shore D. According to paragraph 1,
A polyester resin that does not cause fusion between pellets at a temperature of 40°C or higher when the polyester resin is manufactured into pellets. According to paragraph 1,
The polyester resin includes polyether polyol in an amount of 9 to 34% by weight based on the total weight of the polyester resin. (1) (a) an acid component containing an aromatic dicarboxylic acid; and (b) (b-1) ethylene glycol and 1,4-cyclohexanedimethanol, and (b-2) polyether polyol containing at least one selected from the group consisting of polypropylene glycol and polytetramethylene glycol. Esterifying or transesterifying a polyester resin composition containing an alcohol component in the presence of a titanium-based catalyst; and
(2) subjecting the reaction product of step (1) to a polycondensation reaction,
In step (1), the 1,4-cyclohexanedimethanol and polyether polyol are used in amounts of 2 to 40% by weight and 16 to 54% by weight, respectively, based on the total weight of the alcohol component, and the ethylene glycol is It is used in an amount of 42.1 to 58.8% by weight based on the total weight of the alcohol component,
A method for producing a polyester resin having a haze of 10% or less and a heat of fusion of 10.6 to 40 J/g when manufactured into a 2 mm thick sheet. According to clause 12,
A method for producing a polyester resin, which is carried out by further adding a branching agent containing a trifunctional or higher polycarboxylic acid, a trifunctional or higher polyol, or a mixture thereof to the esterification or transesterification reaction in step (1). According to clause 12,
A method for producing a polyester resin, which is carried out by further adding a phosphorus (P)-based antioxidant, a cobalt acetate-based colorant, or both to the polycondensation reaction of step (2).