TWI702242B - Polyester resin composition - Google Patents

Abstract

The present invention provides a polyester resin composition with excellent transparency and flexibility, and with high thermal resistance, which is capable of suppressing leaking of oligomer to be low and renders stick between compacts on pellets to be difficult to occur.

The polyester resin composition of this invention contains polyester obtained by bringing a dicarboxylic acid component including (a) an alicyclic dicarboxylic acid of 75 to 98 mole%, and (b) a dimer acid of 2 to 25 mole%, and a diol component including (c) an alicyclic diol of 75 mole% or more into polymerization reaction. (a)the alicyclic dicarboxylic acid is preferably an alicyclic dicarboxylic acid with a carbon number of 5 to 30. With respect to the total amount of the trans- and cis- form components of the (a) alicyclic dicarboxylic acid included in the polyester resin composition, the ration of the trans-form component is preferably 80% or more. The (b) dimer acid is preferably a dimer acid with a carbon number of 36 or a carbon number 44.

Description

Polyester resin composition

The present invention relates to polyester resin compositions used in various molding materials. More specifically, it relates to excellent transparency, flexibility, high heat resistance, and low bleed-out of oligomers. A polyester resin composition that does not easily cause adhesion between molded products or pellets.

Polyester represented by polyethylene terephthalate (PET) is widely used as a material for bottles and sheets due to its excellent transparency and mechanical properties. Polyester is usually produced by subjecting a dicarboxylic acid component and a diol component to an esterification and/or transesterification reaction, taking the diol component out of the reaction system under reduced pressure, and performing a polycondensation reaction.

For example, although by using terephthalic acid component and ethylene glycol component or 1,4-butanediol component, PET and polybutylene terephthalate (PBT) homopolymers can be obtained respectively, but by Dicarboxylic acid components and/or glycol components other than these monomer components constituting PET and PBT are added to obtain copolyesters having various properties. In particular, by copolymerizing polyesters such as PET and PBT with polyoxy tetramethylene glycol (polyoxy tetramethylene glycol), flexibility can be imparted, and by copolymerizing with other monomers for amorphous phase formation, it can be obtained Soft copolyester similar to soft vinyl chloride resin (For example, refer to Patent Documents 1 to 3).

However, the glass transition temperature (Tg) of this soft copolyester that undergoes amorphous phase transformation is mostly at room temperature, that is, below 25°C. Therefore, after molding, when exposed to a temperature above Tg for a long time, The oligomers in the soft polyester resin will bleed out, and some of them will form fine crystals, causing the molded product to lose transparency and surface gloss. In addition, the amorphous phase will reduce the heat resistance of the resin, and as a result, there will also be a problem of smashing between molded products or between pellets before molding.

In contrast to this, for example, in Patent Document 4, it has been reported that a polyester resin that has been copolymerized with polyoxytetramethylene glycol is combined with isophthalic acid 5-sodium sulfonate or its diester derivative When the components are copolymerized, it can reduce the exudation of oligomers. However, in the method of Patent Document 4, although a polyester resin with reduced exudation over time can be obtained, the problem of adhesion between molded products or pellets cannot be solved because of insufficient heat resistance.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3270185

[Patent Document 2] Japanese Patent Application Publication No. 2000-302888

[Patent Document 3] Japanese Patent Laid-Open No. 2002-363271

[Patent Document 4] Japanese Patent No. 4764054

The present invention is created to solve the aforementioned problems. The purpose is to provide a polyester resin composition which is excellent in transparency, flexibility, and high heat resistance, can suppress the exudation of oligomers to a low level, and is unlikely to cause adhesion between molded products or pellets.

In view of the aforementioned problems of the prior art, the inventors conducted an in-depth review and found that a polyester containing alicyclic dicarboxylic acid and alicyclic diol as the main components is dimerized with 2 to 25 mol% The polyester resin obtained by acid copolymerization can maintain excellent transparency even if it is crystallized, and has excellent flexibility, high heat resistance, and can suppress oligomer bleeding to a low level. In addition, it is not easy to occur The glue between the molded product or the material particles becomes a resin that satisfies all the requirements, and the present invention is completed.

That is, the polyester resin composition of the present invention contains a polyester resin, wherein the polyester resin is composed of (a) 75 to 98 mole% of alicyclic dicarboxylic acid and (b) dimer acid 2 The dicarboxylic acid component to 25 mol% and the diol component containing 75 mol% or more of (c) alicyclic diol are formed by polymerization.

Furthermore, in the aforementioned polyester resin composition, (a) the alicyclic dicarboxylic acid is preferably an alicyclic dicarboxylic acid having 5 to 30 carbon atoms.

Furthermore, in the aforementioned polyester resin composition, the ratio of the trans form relative to the total of the trans form and the cis form of the (a) alicyclic dicarboxylic acid unit contained in the polyester resin composition is preferably Above 80%.

Meanwhile, in the aforementioned polyester resin composition, (b) the dimer acid is preferably a dimer acid with 36 carbons or 44 carbons.

The polyester resin composition of the present invention has excellent transparency, flexibility, and high heat resistance, can suppress the exudation of oligomers to a low level, and is unlikely to cause adhesion between molded products or pellets.

Hereinafter, the embodiments of the present invention will be described in detail, but they are not limited to these contents without departing from the spirit of the present invention.

The polyester resin composition of the present invention contains polyester resin, wherein the polyester resin is composed of (a) alicyclic dicarboxylic acid 75 to 98 mole% and (b) dimer acid 2 to 25 mole% The dicarboxylic acid component and the diol component containing more than 75 mol% of (c) alicyclic diol are formed by polymerization.

<Dicarboxylic acid component>

(a) Alicyclic dicarboxylic acid

(a) Alicyclic dicarboxylic acids, which have monocyclic cycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and bicyclic alkanes such as decalin (decalin) The so-called alicyclic structure and a compound with two carboxyl groups. The alicyclic dicarboxylic acid used in the present invention can be exemplified as: 1,2-, 1,3-, 1,4-cyclohexane dicarboxylic acid, 1,4-, 1,5-, 2 ,6-,2,7-decahydronaphthalene dicarboxylic acid, etc. Among them, when 1,4-cyclohexanedicarboxylic acid is used, the molding temperature of the obtained polyester will be close to the previous molding temperature, and it is easy to obtain industrially, so it is preferable.

In addition, (a) alicyclic dicarboxylic acid may be a derivative such as an unsubstituted compound or an alkyl ester. The alkyl ester derivatives include alkyl esters having 1 to 10 carbon atoms, more specifically, dimethyl ester, diethyl ester, etc., particularly suitable Use dimethyl ester together. Furthermore, although there is no particular limitation, when unsubstituted alicyclic dicarboxylic acid is used as a polymerization raw material and directly esterified and polymerized, it is easy to produce a difference from trans to cis in the polymerization reaction. The structure makes it difficult to control the ratio of the trans compound contained in the resin to 80% or more. Therefore, for alicyclic dicarboxylic acids, it is particularly preferable to use alkyl esters.

In the polyester resin composition of the present invention, the content of (a) alicyclic dicarboxylic acid is 75 to 98 mol% in the total amount of the dicarboxylic acid component. Moreover, it is more preferable to be 80 to 90 mol% in the total amount of the dicarboxylic acid component. When (a) the alicyclic dicarboxylic acid is less than 75 mol%, the crystallization rate of the polymer will be reduced, resulting in poor molding processability. In addition, when a component other than (a) alicyclic dicarboxylic acid is used as the main component of the dicarboxylic acid, for example, when an aromatic dicarboxylic acid is used, it may whiten over time, or sufficient transparency may not be obtained.

With respect to the total of (a) the trans form of the alicyclic dicarboxylic acid unit contained in the polyester resin composition of the present invention and the cis form, the ratio of the trans form is desirably 80% or more, and more desirably 90 %the above. When the ratio of the trans compound is less than 80%, the melting point of the polymer is lowered, thereby reducing the heat resistance, and it is difficult to maintain the transparency after crystallization due to the breakdown of the crystallinity balance, so the transparency may be poor, or it may occur over time Albino situation. Moreover, although the higher the ratio of the trans compound, the more heat-resistant resin is obtained, but the isomerization from the trans compound to the cis compound occurs in the polymerization step. Therefore, for example, in the resin after polymerization It is usually not easy to obtain a trans-form ratio of more than 95%.

In addition, in the (a) alicyclic dicarboxylic acid used as a polymerization raw material, the ratio of the isomers of the trans form and the cis form is defined as trans form/cis form = 90/10 to 100/0 Preferably, 95/5 to 100/0 is more preferable. Considering the isomerization from trans to cis in the polymerization step, when the ratio of trans is less than 90%, it will be difficult to control the ratio of trans in the resin to 80% or more.

(b) Dimer acid

(b) Dimer acid refers to a dicarboxylic acid compound obtained by dimerizing unsaturated fatty acid with carbon number 10 to 30, for example, by combining oleic acid and linoleic acid with carbon number 18 Unsaturated fatty acid, erucic acid and other unsaturated fatty acids with carbon number 22 are obtained by dimerization of carbon number 36 or 44 dimer dicarboxylic acid, or a derivative formed by its ester. The dimer acid obtained by saturating the remaining unsaturated double bonds after dimerization by hydrogenation is called hydrogenated dimer acid. In terms of reaction stability, flexibility, and impact resistance, hydrogenation can be suitably used. Dimer acid. In addition, (b) dimer acid is usually obtained as a mixture of compounds having a linear branched structure, an alicyclic structure, and the like. Depending on the manufacturing steps, these content rates will vary, but these content rates There are no special restrictions.

In the polyester resin composition of the present invention, the content of (b) dimer acid is 2 to 25 mol% in the total amount of the dicarboxylic acid component. Moreover, it is more preferable to be 10 to 20 mole% in the total amount of the dicarboxylic acid component. When the (b) dimer acid is outside the range of 2 to 25 mol%, the crystallization of the polymer is out of balance, and it is difficult to obtain high transparency even if it is crystallized. Also, when (b) dimer acid is less than 2 mol%, the flexibility of the polymer will be poor, and when it exceeds 25 mol%, the crystallization speed of the polymer will slow down, resulting in poor moldability Propensity.

other

In addition, in the polyester resin composition of the present invention, an appropriate amount of dicarboxylic acid components other than (a) alicyclic dicarboxylic acid and (b) dimer acid can also be used as a polymerization raw material, such as terephthalic acid , Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid and other aromatic dicarboxylic acids, as well as succinic acid, glutaric acid, Aliphatic dicarboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc. In addition, such a dicarboxylic acid component may be used individually or in combination of 2 or more types.

<Diol component>

(c) Alicyclic diol

(c) Alicyclic diols are compounds with alicyclic structures such as monocyclic alkanes and bicyclic alkanes and containing two hydroxyl groups, such as 1,2-, 1,3-cyclopentanediol , 1,2-, 1,3-cyclopentane dimethanol, bis(hydroxymethyl)tricyclo[5.2.1.0]decane and other 5-membered cyclic diols, 1,2-,1,3-,1, 4-cyclohexanediol, 1,2-, 1,3-, 1,4-cyclohexanedimethanol, 2,2-bis-(4-hydroxycyclohexyl)-propane and other 6-membered cyclic diols, etc. . Among them, 1,2-, 1,3-, 1,4-cyclohexanedimethanol are preferred, especially 1,4-cyclohexanedimethanol, whose hydroxymethyl group is in the para position, which makes it highly reactive , And easy to obtain high degree of polymerization polyester, so it can be suitable for use. In addition, 1,4-cyclohexanedimethanol is usually a mixture of trans and cis, and the ratio of trans/cis of 1,4-cyclohexanedimethanol as a polymerization raw material is used, and It is not particularly limited, but 80/20 to 60/40 is preferred, and 75/25 to 70/30 is more preferred.

In the polyester resin composition of the present invention, the content of (c) alicyclic diol is 75 mol% or more in the total amount of diol components. Moreover, it is more preferable that the total amount of the glycol component is 85 mol% or more, and the glycol component The total amount of the component is (c) alicyclic diol. (C) When the alicyclic diol is less than 75 mol%, the heat resistance of the polymer will be poor, so it is easy to occur between molded products and between particles, and it will also slow down the speed of crystallization. This results in poor forming processability.

other

As long as the total amount of diol components is less than 25 mol%, diol components other than (c) alicyclic diol may be used. (c) For glycol components other than alicyclic glycol, for example, ethylene glycol, propylene glycol, butylene glycol, hexanediol, octanediol, decanediol, or bisphenol A, bisphenol S, etc. Ethylene oxide adducts, trimethylolpropane and the like can be used alone or in combination of two or more.

<Method for manufacturing polyester resin composition>

The manufacturing method of the polyester resin composition of the present invention is not particularly limited. The polymerization reaction of the dicarboxylic acid component and the diol component can be carried out by a known method using a known catalyst. Either the method of esterification directly with unsubstituted dicarboxylic acid as the starting material, or the method of ester exchange reaction with esterification such as dimethyl ester as the starting material, but the unsubstituted (a) When the alicyclic dicarboxylic acid is directly esterified, it is easy to produce isomerization from trans to cis in the polymerization reaction, making it difficult to control the ratio of trans to 80% or more, so it is used (a ) The transesterification reaction of the esterified product of alicyclic dicarboxylic acid is desired. More specifically, after carrying out the transesterification reaction and the esterification reaction under normal pressure using a known catalyst, it is desirable to continue to use the known catalyst to further carry out the polymerization reaction under reduced pressure.

When reacting the components (a) to (c) as the polymerization raw material At this time, it is desirable to adjust the amount of the diol component appropriately before using it so that the molar ratio of the total diol component/total dicarboxylic acid component in the raw material is in the range of 0.8 to 1.5, more preferably 0.9 to 1.3 . When the aforementioned molar ratio exceeds 1.5, in (a) alicyclic dicarboxylic acid, isomerization from the trans form to the cis form is likely to occur, causing the trans form contained in the resin after polymerization The ratio becomes low, so the heat resistance is poor. In addition, when the aforementioned molar ratio is less than 0.8, the transesterification reaction may not proceed smoothly, and the molecular weight of the obtained resin may become small, and mechanical properties sufficient for practical use may not be obtained.

As for the catalyst for the transesterification reaction, it is preferable to use at least one metal compound. As for the preferable metal elements, sodium, potassium, calcium, titanium, lithium, magnesium, manganese, zinc, tin, cobalt and the like are used. Among them, titanium and manganese compounds have high reactivity, and the color tone of the obtained resin is also good, which is preferable. The amount of the transesterification catalyst used is usually 5 to 1000 ppm, preferably 10 to 100 ppm, relative to the polyester resin produced.

The transesterification reaction can be carried out, for example, by adding each component used as a polymerization raw material and other various copolymerization components as necessary to a reaction tank equipped with a heating device, a stirrer, and a distillation tube, and then adding The reaction catalyst is stirred and heated in an inert gas environment at normal pressure to distill off by-products such as methanol produced by the reaction, and at the same time make the reaction proceed. The reaction temperature is 150°C to 270°C, preferably 160°C to 260°C, and the reaction time is usually about 3 to 7 hours.

In addition, after the transesterification reaction is completed, it is preferable to further perform the esterification reaction by adding a phosphorus compound of more than moles such as a transesterification catalyst. In the present invention, it is preferable to use (a) alicyclic dicarboxylic acid initially After the ester compound of the acid and the (c) alicyclic diol undergo the transesterification reaction, the (b) dimer acid and the phosphorus compound are added together to allow the esterification reaction to proceed, thereby producing the products containing (a) to (c) The components of polyester resin. As for the phosphorus compound, for example, phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite, etc. may be mentioned. Among them, trimethyl phosphate is particularly preferred. The amount of phosphorus compound used is usually 5 to 1000 ppm, preferably 20 to 100 ppm, relative to the polyester resin produced.

At the same time, the transesterification reaction and the esterification reaction are continued, and then the polycondensation reaction is carried out to reach the desired molecular weight. As for the catalyst for the polycondensation reaction, it is preferable to use at least one metal compound. Preferred metal elements include titanium, germanium, antimony, aluminum and the like. Among them, titanium and germanium compounds have high reactivity, and the obtained resin also has excellent transparency, so it is particularly preferable. The amount of the polymerization catalyst used is usually 30 to 1000 ppm, preferably 50 to 500 ppm relative to the polyester resin produced.

The polycondensation reaction can be carried out, for example, in a reaction tank where the product after the completion of the transesterification reaction and the esterification reaction described above is placed, after adding a polycondensation catalyst, and then gradually increasing the temperature in the reaction tank and reducing the pressure. The pressure in the tank is reduced from a normal pressure environment to a final pressure of 0.4 kPa or less, preferably 0.2 kPa or less. The temperature in the tank is increased from 220 to 230°C to finally 250 to 290°C, preferably 260 to 270°C. After reaching a predetermined torque, the reaction product is squeezed from the bottom of the tank and recovered. Usually, the reaction product is extruded into strands in water, and after cooling, it is sheared to obtain pelletized polyester resin.

The polyester resin composition of the present invention can be appropriately formulated with various additives such as antioxidants, heat stabilizers, lubricants, antistatic agents, plasticizers, ultraviolet absorbers, pigments, etc., depending on the application and molding purpose. Moreover, these additional components can be blended in any step of the polymerization reaction step and the processing/forming step. In terms of antioxidants, for example, hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, etc., hindered phenol antioxidants are particularly suitable for use, and the ring content is preferably about 100 to 5000 ppm. In order to stabilize the electrostatic adhesion of the cooling roll when forming the melt-extruded film, a metal salt such as magnesium acetate, calcium acetate, and magnesium chloride may be added.

The polyester resin composition of the present invention has excellent flexibility, transparency, high heat resistance, and is not prone to exudation, adhesion between molded products or between particles, and is also excellent in stability and molding processability over time. It is widely used in various molding materials such as electrical and electronic parts and automotive materials.

In the polyester resin composition of the present invention, the reaction product of alicyclic dicarboxylic acid and alicyclic diol has a faster crystallization rate than PET and slower than PBT. Furthermore, by copolymerizing this composition with dimer acid, flexibility is imparted, crystallization speed is adjusted, and thermal characteristics are improved. At the same time, in the polyester of the present invention, since fine crystals below the wavelength of visible light are formed, a resin with excellent transparency can be obtained even if it is crystallized.

Example

Hereinafter, examples will be used to illustrate the content of the present invention in more detail, but within the scope not departing from the spirit of the present invention, it is not limited to the following examples. Furthermore, the methods used in each embodiment and comparative example are as follows the following.

(1) The ratio of the trans form of alicyclic dicarboxylic acid in the polyester resin composition

Dissolve 30-50 mg of polyester resin composition in 50 vol% deuterium chloroform containing trifluoroacetic acid, and then calculate the trans form from the measured NMR spectrum using a 400MHz 1H-NMR analyzer (manufactured by Bruker) Ratio.

(2) Glass transition temperature (Tg), crystallization temperature (Tc) and melting point (Tm)

Using 10 mg of the polyester resin composition, measuring with a differential scanning calorimeter DSC (manufactured by Perkin Elmer, DSC 7 type) at a heating rate of 10°C/min, the Tg, Tc, and Tc are determined from the obtained DSC curve. Tm.

Furthermore, in the present invention, from the viewpoint of flexibility, Tg≦25°C is preferable, from the viewpoint of heat resistance, Tm≧150°C is preferable, and from the viewpoint of adjusting the crystallization rate , Preferably Tc≦100°C.

(3) Haze

Using an injection molding machine (manufactured by Nippon Steel Co., Ltd., J150 SA type), molded into a polyester resin composition board (thickness 2mm) at a resin temperature of 260°C, and then using a haze meter (manufactured by Nippon Denshoku Co., Ltd., NDH 4000 type), determine the haze.

(4) Elasticity

Using an injection molding machine (manufactured by Nippon Steel Works, J150 SA type), a test piece of polyester resin composition (according to ISO 527-2, No. 1A) was molded at a resin temperature of 260°C, and then a TENSILON universal testing machine (TS Engineering Company, UCT-2.5T type), the elastic modulus was measured.

From the viewpoint of flexibility, the elastic modulus is preferably 300 MPa or less.

(5) Adhesion test under load

Put the pellets of the polyester resin composition into a cylindrical container with an inner diameter of 55 mm and a height of 37 mm, and apply a load of 5 kg from above. After keeping it in an oven heated to 100°C for 3 hours, confirm the appearance and appearance of the resin. Whether it is stuck.

(6) Exudative

Use an injection molding machine (manufactured by Nippon Steel Works, J150SA type) to shape a polyester resin composition board (thickness 2mm) at a resin temperature of 260°C, and then place it in an oven at 60°C for one week. Confirm Whether oligomers are deposited on the surface of the plate.

The inventors of the present invention produced polyester resins in the following Examples and Comparative Examples, and evaluated various properties using the above methods. The raw material composition of the polyester resin composition of each Example and Comparative Example and the results of the property evaluation of the obtained resin are collectively shown in Table 1 and Table 2.

<Example 1>

In a reactor equipped with a stirrer, a distillation tube and a pressure reducing device, add (a) dimethyl 1,4-cyclohexanedicarboxylate (DMCD, the ratio of trans is 98%) 12.90 kg, (c ) 11.47 kg of 1,4-cyclohexane dimethanol (CHDM) and 0.11 kg of a 10% EG solution of Mn acetic acid tetrahydrate were heated to 200°C under nitrogen flow, and then heated to 230°C over 1 hour. After keeping it as it is for 2 hours and then carrying out the transesterification reaction, (b) dimer acid derived from erucic acid (carbon number 22, manufactured by Croda, PRIPOL 1004 type) 10.30 kg, trimethyl phosphate is added to the reaction system 10% EG solution 0.11kg, and continue the esterification reaction at 230°C for 1 hour. After that, 300 ppm of germanium dioxide was added as a polycondensation catalyst and stirred, and the pressure was reduced to 133 Pa or less over 1 hour, during which the internal temperature was increased from 230°C to 270°C, and then stirred under a high vacuum of 133 Pa or less until it became a predetermined The polycondensation reaction proceeds up to the viscosity. Afterwards, the obtained polymer is extruded into strands in water, and then sheared into pellets. The thermal properties, haze, light transmittance, elastic modulus and composition of the obtained polyester resin are shown in Table 1.

<Examples 2 to 7>

Except that the polymer composition was changed as shown in Table 1, the rest was performed in the same manner as in Example 1 above to produce pelletized polymers of Examples 2 to 7, and then various properties of the obtained polymers were evaluated.

<Comparative Example 1>

In a reactor equipped with a stirrer, a distillation tube and a decompression device, add 8.86 kg of oligomers with a molar ratio of ethylene glycol to terephthalic acid of 1.10, and then increase the temperature to 240°C and simultaneously Let it dissolve. After that, 1.46 kg of 1,4-cyclohexanedimethanol and 0.01 kg of trimethylolpropane were added, the temperature was increased to 250° C., and the mixture was stirred as it is for 60 minutes. Then, 2.79kg of polyoxytetramethylene glycol with a number average molecular weight of 1000 was added as the fourth [methylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl) as a heat stabilizer ) Propionate] Methane 0.3kg. After the internal temperature reaches 250°C, add 300 ppm of germanium dioxide as a polymerization catalyst and 60 ppm of triethyl phosphate as a phosphorus element. After stirring, the pressure is reduced to 133 Pa or less in 1 hour, during which the internal temperature rises to 260 ℃. Then stir under the high vacuum below 133Pa until it reaches the predetermined viscosity to carry out the polycondensation reaction, then squeeze it into the water from the nozzle It is pressed into a rope shape and then sheared by a granulator to obtain a pelletized polymer. In the same manner as in Example 1, the properties of the obtained polyester resin were evaluated.

<Comparative Examples 2 to 7>

Except that the polymer composition is changed as shown in Table 2, the rest is the same as the above-mentioned Comparative Example 1 to produce pelletized polymers of Comparative Examples 2 to 7, and then various properties of the obtained polymers are evaluated.

As shown in Table 1, (a) 76 to 92 mole% of dimethyl 1,4-cyclohexanedicarboxylate, (b) dimer acid derived from erucic acid (carbon number 44), 24 to 8 mole% The polyester resins of Examples 1 to 4, which are prepared by using the dicarboxylic acid component and (c) 1,4-cyclohexanedimethanol as the diol component, have excellent heat resistance (Tg, Tc, Tm), Moreover, the transparency (haze) and flexibility (tensile elastic modulus) are also good. At the same time, there will be no sticking after applying a load and heat. The appearance of good transparency can be maintained despite the crystallization, and at 60℃ After a week of storage, oligomers hardly ooze out. In addition to (c) cyclohexane dimethanol, 20 mol% of ethylene glycol was also used as the diol component of the polyester resin of Example 5, and dimer acid (carbon number 36) derived from oleic acid was used as (b) In the polyester resin of Comparative Example 8 of the dimer acid, as in Examples 1 to 4, good results were obtained in all evaluations. In addition, the polyester resin of Example 7 in which the polymerization raw material (a) 1,4-cyclohexanedicarboxylic acid (DMCD) was changed so that the ratio of the trans product after polymerization was 75.2%, although the adhesion test under a load The appearance of the middle resin is translucent, and the transparency tends to decrease slightly over time, but all other evaluations are good.

In contrast, as shown in Table 2, the soft polyester resin of Comparative Example 1, which is composed of a PET resin copolymerized with cyclohexanedimethanol and polyoxytetramethylene glycol, has low Tg and oligomerization occurs over time. Exudation, not only that, because it is an amorphous phase, it will also occur between particles under load. Compared with the polyester composition of Comparative Example 1, the soft polyester resin of Comparative Example 2 in which a sodium isophthalate sulfonate derivative is further added for copolymerization, although it can inhibit the exudation of oligomers, it will still be under load Glue between particles occurs.

Also, for the dicarboxylic acid component, aromatic dicarboxylic acid (for The polyester resin of Comparative Example 3 of phthalic acid) and (b) dimer acid had some whitening due to crystallization in the adhesion test under a load. As for the diol component, the polyester resin of Comparative Example 4 in which aliphatic diol (1,4-butanediol) is used alone, it crystallizes and atomizes immediately after extrusion, and sufficient transparency (haze) cannot be obtained. . (b) The polyester resin of Comparative Example 5 with the dimer acid content set to 1 mol%, the resin becomes too hard, but the flexibility (tensile elasticity) is insufficient, and fogging occurs in the adhesion test under load . On the other hand, (b) the polyester resin of Comparative Example 6 with the dimer acid content set to 28 mol% had insufficient transparency (haze). At the same time, the polyester resin of Comparative Example 7 using (c) 1,4-cyclohexanedimethanol 60 mol% and ethylene glycol 40 mol% as the diol component, it was unable to mold the test piece, and the weight Adhesion of the pellets will occur in the staleness test.

Claims (3)

A polyester resin composition containing polyester resin, wherein the polyester resin is composed of (a) alicyclic dicarboxylic acid 75 to 98 mol% and (b) carbon 44 dimer acid 2 to 25 mol% of dicarboxylic acid component and (c) alicyclic diol containing 75 mol% or more of diol component are formed by polymerization. The polyester resin composition according to the first item of the patent application, wherein (a) the alicyclic dicarboxylic acid is an alicyclic dicarboxylic acid having 5 to 30 carbon atoms. The polyester resin composition described in item 1 or item 2 of the scope of the patent application, wherein the trans and cis forms of (a) alicyclic dicarboxylic acid units contained in the polyester resin composition In total, the ratio of trans-forms is 80% or more.