KR20150077359A - Polycyclohexylenedimethylene terephthalate resin composition - Google Patents

Abstract

According to an embodiment of the present invention, a polycyclohexylenedimethylene terephthalate resin composition can maintain excellent injection molding properties, with improved tensile strength, tensile elongation, and impact strength. The present invention relates to a polycyclohexylenedimethylene terephthalate resin composition, which comprises: a first polycyclohexylenedimethylene terephthalate resin composition with a crystal melting point above 295°C and with intrinsic viscosity below 0.75 dL/g; and a second polycyclohexylenedimethylene terephthalate resin composition with a crystal melting point below 280°C and with intrinsic viscosity above 0.75 dL/g.

Description

[0001] POLYCYCLOHEXYLENEDIMETHYLENE TEREPHTHALATE RESIN COMPOSITION [0002]

The present invention relates to a polycyclohexylenedimethylene terephthalate resin composition having improved tensile strength, tensile elongation and impact strength while maintaining excellent injection moldability.

Polyalkylene terephthalate has properties such as abrasion resistance, durability and heat resistance and is used as a material for fibers, films, molded products and the like. Examples of the polyalkylene terephthalate include poly (ethylene terephthalate) (PET), poly (butylene terephthalate) (PBT), polycyclohexylenedimethylene terephthalate (Poly (cyclohexylenedimethylene terephthalate), hereinafter referred to as " PCT "). Of these, the most widely used materials commercially are PET, which is used for fiber and bottle applications.

PET, despite its excellent physical properties, is relatively slow in crystallization rate, so it needs the help of a nucleating agent and a crystallization accelerator to be used for engineering plastics requiring high crystallinity. Further, PET has a problem that the mold temperature must be kept relatively high during the injection molding process to keep the crystallization speed high.

Since PBT has a higher crystallization rate than PET, it overcomes the problem of PET for the above-mentioned engineering plastics, that is, the slow crystallization speed, and has been widely used in engineering plastics applications. However, PBT has a low thermal deformation temperature compared to PET, and thus its use has been limited to applications requiring high heat resistance despite excellent moldability compared to PET.

PCT has been attracting attention as a new material capable of overcoming the problems of the above-mentioned polyester material, that is, the problem of moldability due to the slow crystallization rate and the limitation of application development due to low heat distortion temperature. The PCT is obtained by esterification of terephthalic acid (hereinafter referred to as 'TPA') or dimethyl terephthalate (hereinafter referred to as 'DMT') and 1,4-cyclohexanedimethanol (hereinafter referred to as 'CHDM') Or a crystalline polyester produced by transesterification or transesterification.

On the other hand, polyalkylene terephthalate resins such as PCT have high abrasion resistance, durability and heat resistance and are used in the production of fibers, films and molded articles. At this time, the high crystallinity of the resin is essential in securing suitable hardness, strength and heat resistance at a high temperature.

However, when the degree of crystallization of the resin is increased, the brittleness and modulus of the material increase, but the elongation decreases. As the tensile elongation of the plastic material is lowered and the brittleness is increased, it can easily break the external force. Particularly, injection molding of a material with increased crystallinity may cause a problem that the cooled plastic material is stuck in the mold due to poor tensile elongation, or the cooled plastic material is not easily released from the mold.

In order to solve such a problem, a method of increasing the molecular weight of the resin can be considered. When the molecular weight of the resin is increased, the mechanical strength of the molded article formed from the resin is improved and the molded article can be reliably released from the mold at the time of injection molding.

However, if the molecular weight of the resin is increased, the viscosity of the molten resin increases during the injection process, which causes the flowability of the molten resin to drop sharply and the injection pressure to surge.

Therefore, it is inevitable to develop a composition having an excellent flowability during injection molding and having excellent workability and capable of stable release from a mold after crystallization.

The present invention is to provide a polycyclohexylene dimethylene terephthalate resin composition having an improved tensile strength, a tensile elongation and an impact strength while maintaining excellent injection moldability.

The present invention also provides a molded article formed from the resin composition.

According to one embodiment of the invention, a first polycyclohexylenedimethylene terephthalate resin having a crystalline melting point of 295 DEG C or higher and an intrinsic viscosity of 0.75 dL / g or less; And a second polycyclohexylenedimethylene terephthalate resin having a crystal melting point of 280 DEG C or less and an intrinsic viscosity of 0.75 dL / g or more.

The resin composition may include 50 to 95% by weight of the first polycyclohexylenedimethylene terephthalate resin and 5 to 50% by weight of the second polycyclohexylenedimethylene terephthalate resin based on the total weight of the resin.

The first and second polycyclohexylenedimethylene terephthalate resins having the above physical properties can be polymerized using specific monomers.

As an example, the first polycyclohexylenedimethylene terephthalate resin may be polymerized using cyclohexane dimethanol having a trans isomer ratio of at least 70 mol%.

As another example, the second polycyclohexylenedimethylene terephthalate resin may be polymerized using cyclohexane dimethanol having a trans isomer ratio of 65 mol% or less.

In still another embodiment, the second polycyclohexylenedimethylene terephthalate resin may include isophthalic acid, an isophthalic acid ester compound, ethylene glycol, 1,3-propanediol, 1,4-butanediol, Polypropylene glycol, and the like.

The resin composition may further include at least one additive selected from the group consisting of fillers, pigments, oxidation stabilizers, lubricants, reinforcing agents and nucleating agents. The additive may be included in an amount of 20 to 60 parts by weight based on 100 parts by weight of the total resin.

According to another embodiment of the present invention, there is provided a molded article formed from the polycyclohexylenedimethylene terephthalate resin composition.

The polycyclohexylenedimethylene terephthalate resin composition according to one embodiment of the present invention can exhibit improved tensile strength, tensile elongation and impact strength while maintaining excellent injection moldability.

A polycyclohexylenedimethylene terephthalate resin composition according to a specific embodiment of the present invention and a molded article formed therefrom will be described below.

According to one embodiment of the present invention, there is provided a polycyclohexylenedimethylene terephthalate resin composition (hereinafter referred to as " polycyclohexylenedimethylene terephthalate resin composition ") comprising two kinds of polycyclohexylenedimethylene terephthalate resins Referred to as " resin composition "). Specifically, the resin composition comprises: a first PCT resin having a crystal melting point of 295 DEG C or higher and an intrinsic viscosity of 0.75 dL / g or less; And a second PCT resin having a crystal melting point of 280 DEG C or less and an intrinsic viscosity of 0.75 dL / g or more. The intrinsic viscosity is calculated by the method described in the following Examples.

Compositions comprising resins that generally exhibit high crystallinity exhibit high brittleness and modulus but exhibit poor tensile elongation. However, according to one embodiment of the present invention, it is possible to provide a resin composition in which two kinds of PCT resins showing different physical properties are combined to improve the tensile elongation while maintaining excellent crystallinity. Specifically, a resin composition comprising a first PCT resin having a crystal melting point of 295 DEG C or higher and an intrinsic viscosity of 0.75 dL / g or less and a second PCT resin having a crystal melting point of 280 DEG C or lower and an intrinsic viscosity of 0.75 dL / The injection molding process can be carried out even in a thin flow path in the mold during the injection process and can be crystallized at a high speed. In addition, the resin composition has an excellent tensile elongation, so that an injection molded article formed from the resin composition can be reliably released from a mold without breakage.

The resin composition comprises 50 to 95% by weight or 60 to 95% by weight of the first PCT resin, 5 to 50% by weight or 5 to 40% by weight of the second PCT resin, . ≪ / RTI > When the first and second PCT resins are blended in the above range, excellent injection moldability and tensile properties can be exhibited at the same time.

The first and second PCT resins may be prepared by polymerizing specific monomers so as to have the above-described physical properties.

For example, the first PCT resin having a high melting point and a low viscosity relative to the second PCT resin may be obtained by esterifying 1,4-cyclohexanedimethanol having a high ratio of trans isomers with terephthalic acid, Cyclohexanedimethanol with an ester compound of terephthalic acid.

The generally used 1,4-cyclohexanedimethanol comprises 70 mol% of the trans isomer and the balance of the cis isomer. When 1,4-cyclohexane dimethanol is isomerized in the presence of a catalyst, the content of cis and trans isomers of 1,4-cyclohexane dimethanol can be changed.

The first PCT resin obtained by polymerizing the 1,4-cyclohexane dimethanol with a trans isomer ratio of 70 mol% or more, 73 mol% or more, or 75 mol% or more has high melting point and heat resistance and can exhibit high crystallinity.

In another example, the second PCT resin having a low melting point and a high viscosity relative to the first PCT resin may be prepared by esterifying 1,4-cyclohexanedimethanol having a trans isomer content of 65 mol% or less or 60 mol% or less with terephthalic acid, Cyclohexanedimethanol having a proportion of 65 mol% or less or 60 mol% or less with a terephthalic acid ester compound. As described above, when 1,4-cyclohexane dimethanol is used with 1,4-cyclohexane dimethanol, 1,4-cyclohexane dimethanol having a larger ratio of cis isomer to 1,4-cyclohexane dimethanol generally used has a low melting point, A second PCT resin capable of increasing the tensile elongation can be polymerized.

Further, as another example, the second PCT resin can be prepared by adding a copolymerizable monomer to an esterification reaction or an ester exchange reaction. Examples of the copolymerizable monomer include at least one comonomer selected from the group consisting of isophthalic acid, isophthalic acid ester compound, ethylene glycol, 1,3-propanediol, 1,4-butanediol and polypropylene glycol having a molecular weight of 100 to 3000 Can be used. In the case of isophthalic acid, 15 mol% or less or 10 mol% or less of the total dicarboxylic acid may be used. In the case of the isophthalic acid ester compound, it may be used in an amount of 15 mol% or less or 10 mol% or less with respect to the total dicarboxylic acid ester compound. Also, at least one comonomer selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol and polypropylene glycol having a molecular weight of 100 to 3000 is contained in an amount of not more than 15 mol% or not more than 10 mol% .

The second PCT resin can be prepared to have a high molecular weight to ensure excellent tensile properties. The second PCT resin may, for example, have a number average molecular weight of from 15,000 g / mol to 45,000 g / mol. In order to produce the second PCT resin having such a high molecular weight, the steps of esterifying or transesterifying the monomers described above, and then molding the reaction product to form pellets; And / or crystallization of the reaction product or pellet to solid-state polymerize can be further employed.

However, the manufacturing method of the first and second PCT resins is not limited to the above-described manufacturing method. If the first and second PCT resins have the above-mentioned physical properties, Various manufacturing methods can be employed.

The resin composition may further include additives used to supplement or enhance the physical properties of the PCT resin in the technical field to which the present invention belongs. Examples of the additives include at least one additive selected from the group consisting of fillers, pigments, oxidation stabilizers, lubricants, reinforcing agents and nucleating agents.

Examples of the filler include glass fiber, carbon fiber, boron fiber, glass bead, glass flake, talc, carbon black, clay, mica, wollastonite, calcium titanate whisker, aluminum boric acid acid whisker, zinc oxide whisker, calcium whisker, or a mixture thereof. Among them, an acicular filler can be used as a filler in order to provide a molded article excellent in surface smoothness. Particularly, it is preferable to use glass fiber, wollastonite, calcium titanate whisker, aluminum boric acid whisker, or a mixture thereof as the filler in order to provide an excellent surface smoothness and to provide a white molded article Can be used. Among these, glass fiber is used to improve the moldability of the composition, and mechanical properties such as tensile strength, bending strength and flexural modulus of the molded article, and heat resistance such as heat distortion temperature can be improved.

When the glass fiber is used as the filler, a glass fiber such as a filament, a thread, a fiber or a whisker may be used as the glass fiber. Glass fibers having an average length of 0.1 to 20 mm, 0.3 to 10 mm, or 3 to 5 mm may be used as the glass fibers. Further, it is possible to provide a resin composition having excellent mechanical strength by using an aspect ratio (L (average length of fibers) / D (average diameter of fibers)) of 10 to 2000 or 30 to 1000 .

When the needle-shaped filler is used as the filler as described above, a plate-like filler such as mica (mica) may be further added or glass fibers may be used as a mixture in order to prevent the specimen from being twisted.

The pigments include titanium oxide, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, lithopone _{(lithopone, BaSO 4 · ZnS)} , white lead _{(white lead, 2PbCO 3 · Pb} (OH) 2), calcium carbonate, alumina, Boron nitride, a mixture thereof, and the like. Examples of the oxidation stabilizer include AO-60 of ADEKA as a hindered phenol-based oxidation stabilizer.

The lubricant can be used to stably disperse a filler, a pigment or the like in the resin composition and to easily mold the resin composition. Examples of such activator include N, N'-ethylenebis (stearamide) and the like.

The reinforcing agent can impart toughness to the resin composition to improve the tensile strength. Examples of such a reinforcing agent include random terpolymers obtained by polymerizing ethylene, acrylic ester and glycidyl methacrylate under high pressure.

The nucleating agent acts as a nucleus for crystallization during the molding of the resin composition, thereby improving the crystallization rate of the resin composition. Such a nucleating agent may be a sodium salt of montanic acid (Licomont NaV101 from Clariant) or the like.

The additive may be appropriately used depending on the physical properties of the desired resin composition. For example, the additive is used in an amount of 20 to 60 parts by weight based on 100 parts by weight of the total resin, so that the mechanical strength and processability of the first and second PCT resins can be further improved.

The first and second PCT resins contained in the resin composition and optional additives added as needed can be uniformly mixed using, for example, a twin screw extruder.

The resin composition can exhibit excellent tensile properties while having excellent injection moldability due to the combination of two types of PCT resins having different melting points.

According to another embodiment of the present invention, there is provided a molded article formed from the polycyclohexylenedimethylene terephthalate resin composition. The method of molding the resin composition to produce a molded article is well known in the technical field of the present invention, and thus a detailed description thereof will be omitted.

The molded article can be easily produced from a resin composition containing the above-mentioned first and second PCT resins, and can exhibit excellent mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. However, this is provided as an example of the invention, and the scope of the invention is not limited thereto in any sense.

Manufacturing example  One: High melting point  Have PCT  Preparation of resin (A-1)

55 kg of 1,4-cyclohexanedimethanol (CHDM) containing 75 mol% of trans isomer, 48 kg of terephthalic acid (TPA), 7 g of triethylphosphate, 5 g of titanium oxide-based catalyst (trade name Hombifast PC of Sachtleben, %) Was added to the reactor. The temperature of the reactor was then raised to about 280 DEG C and the esterification reaction was carried out at a temperature of about 280 DEG C and normal pressure for about 3 hours.

Thereafter, the product obtained in the esterification reaction was subjected to polycondensation reaction at a temperature of about 295 DEG C and a pressure of 0.5 to 1 torr for about 150 minutes to obtain a PCT resin (A-1) having an intrinsic viscosity of 0.65 dL / g.

The intrinsic viscosity of the PCT resin was determined by dissolving the resin in o-chlorophenol at a concentration of 1.2 g / dL and using a Ubbelodhe viscometer. The temperature of the viscosity tube was kept at 35 ° C and the time (efflux time, t) required for the solvent to pass between the viscosity section a and the time taken for the solution to pass (t ₀ ) Were obtained. Then, the specific viscosity was calculated by substituting the t value and the t ₀ value into the equation (1), and the intrinsic viscosity was calculated by substituting the calculated non-viscosity value into the equation (2).

[Formula 1]

[Formula 2]

In the above equation 2, A was 0.247 as a Huggins constant and c was 1.2 g / dL as a concentration value, respectively.

Manufacturing example  2: High melting point  Have PCT  Preparation of Resin (A-2)

55 kg of 1,4-cyclohexanedimethanol (CHDM) containing 75 mol% of trans isomer, 48 kg of terephthalic acid (TPA), 7 g of triethylphosphate, 5 g of titanium oxide-based catalyst (trade name Hombifast PC of Sachtleben, %) Was added to the reactor. The temperature of the reactor was then raised to about 280 DEG C and the esterification reaction was carried out at a temperature of about 280 DEG C and normal pressure for about 3 hours.

Thereafter, the product obtained in the esterification reaction was subjected to polycondensation reaction at a temperature of about 295 DEG C and a pressure of 0.5 to 1 torr for about 150 minutes to obtain a PCT resin. Then, the PCT resin was pelletized through a pelletizing process. Thereafter, the PCT resin in the form of pellets was further retained at about 250 캜 and under a vacuum condition for about 15 hours to obtain a PCT resin (A-2) having an intrinsic viscosity of 0.80 dL / g.

Manufacturing example  3: Lower melting point  Have PCT  Preparation of Resin (B-1)

55 kg of 1,4-cyclohexanedimethanol (CHDM) containing 70% by volume of trans isomer, 43 kg of terephthalic acid (TPA), 5 kg of isophthalic acid (IPA), 7 g of triethylphosphate, 5 g of titanium oxide-based catalyst (trade name Hombifast PC of Sachtleben, And an effective Ti ratio in the catalyst: 15%). The temperature of the reactor was then raised to about 280 DEG C and the esterification reaction was carried out at a temperature of about 280 DEG C and normal pressure for about 3 hours.

The product obtained in the esterification reaction was subjected to polycondensation reaction at a temperature of about 295 DEG C and a pressure of 0.5 to 1 torr for about 150 minutes to obtain a PCT resin. Then, the PCT resin was pelletized through a pelletizing process. Thereafter, a PCT resin (B-1) in which the pellet-form PCT resin was further subjected to solid phase polymerization to increase the molecular weight was obtained.

Manufacturing example  4: Lower melting point  Have PCT  Preparation of Resin (B-2)

50 kg of 1,4-cyclohexanedimethanol (CHDM) containing 70% by weight of trans isomer, 2.4 kg of ethylene glycol (EG), 48 kg of terephthalic acid (TPA), 7 g of triethylphosphate, 5 g of titanium oxide-based catalyst (trade name Hombifast PC , Effective Ti ratio in the catalyst: 15%) was added to the reactor. The temperature of the reactor was then raised to about 280 DEG C and the esterification reaction was carried out at a temperature of about 280 DEG C and normal pressure for about 3 hours.

The product obtained in the esterification reaction was subjected to polycondensation reaction at a temperature of about 295 DEG C and a pressure of 0.5 to 1 torr for about 150 minutes to obtain a PCT resin. Then, the PCT resin was pelletized through a pelletizing process. Thereafter, a PCT resin (B-2) in which the pellet-form PCT resin was further subjected to solid phase polymerization to increase the molecular weight was obtained.

Manufacturing example  5: Lower melting point  Have PCT  Preparation of Resin (B-3)

A PCT resin (B-3) was obtained in the same manner as in Production Example 4, except that 2.9 kg of 1,3-propanediol (PDO) was used instead of 2.4 kg of ethylene glycol (EG)

Manufacturing example  6: Lower melting point  Have PCT  Preparation of Resin (B-4)

52.25 kg of 1,4-cyclohexanedimethanol (CHDM) containing 70% by mole of trans isomer in Production Example 4 was used. In place of 2.4 kg of ethylene glycol (EG), polypropylene glycol having a number average molecular weight of 1,000 g / mol ) Was obtained in the same manner as in Production Example 4, except that 19.07 kg of the PCT resin (B-4) was used.

Manufacturing example  7: Lower melting point  Have PCT  Preparation of Resin (B-5)

55 kg of 1,4-cyclohexanedimethanol (CHDM) containing 40 mol% of cis isomer, 48 kg of terephthalic acid (TPA), 7 g of triethylphosphate, 5 g of titanium oxide-based catalyst (trade name Hombifast PC of Sachtleben, %) Was added to the reactor. The temperature of the reactor was then raised to about 280 DEG C, and the esterification reaction was carried out at a temperature of about 280 DEG C and normal pressure for about 3 hours.

The product obtained in the esterification reaction was subjected to polycondensation reaction at a temperature of about 295 DEG C and a pressure of 0.5 to 1 torr for about 150 minutes to obtain a PCT resin. Then, the PCT resin was pelletized through a pelletizing process. Thereafter, a PCT resin (B-5) in which the pellet-form PCT resin was further subjected to solid phase polymerization to increase the molecular weight was obtained.

Manufacturing example  8: Lower melting point  Have PCT  Preparation of Resin (B-6)

Except that 55 kg of 1,4-cyclohexanedimethanol (CHDM) containing 40 mol% of the cis isomer in Production Example 7 was used instead of 55 kg of 1,4-cyclohexane dimethanol (CHDM) containing 50 mol% of cis isomer in place of 55 kg of 1,4- , And a PCT resin (B-6) was obtained in the same manner as in Production Example 7.

Table 1 shows raw materials, intrinsic viscosity and melting point of the PCT resins prepared in Production Examples 1 to 8.

Dicarboxylic acid Diol compound Intrinsic viscosity [dL / g] Melting point
[° C] TPA [kg] IPA [kg] CHDM [kg] cis-isomer content
[mol%] Comonomer Comonomer content
[kg] Production Example 1 48 0 55 25 - 0 0.65 295 Production Example 2 48 0 55 25 - 0 0.80 294 Production Example 3 43 5 55 30 - 0 0.81 275 Production Example 4 48 0 50 30 EG 2.4 0.78 276 Production Example 5 48 0 50 30 PDO 2.9 0.79 277 Production Example 6 48 0 52.25 30 Polyol 19.07 0.77 270 Production Example 7 48 0 55 40 - 0 0.82 275 Production Example 8 48 0 55 50 - 0 0.84 265

TPA: terephthalic acid

IPA: isophthalic acid

CHDM: 1,4-cyclohexanedimethanol

cis-isomer content: content of cis-isomer in CHDM

EG: ethylene glycol

PDO: 1,3-propanediol

polyol: Polypropylene glycol having a number average molecular weight of 1,000 g / mol

Example  1 to 18 and Comparative Example  1 to 2: PCT  Preparation of resin composition

(AO-60 manufactured by ADEKA) and a lubricant (Hi-Lube manufactured by Sinwon Chemical Co., Ltd.) were blended with one or two kinds of PCT resins as shown in the following Table 2, 40 mm, L / D = 44), and extruded to prepare pellets.

The pellets were placed in an extruder heated to about 295 DEG C and the molten resin composition was injected into an ASTM tensile specimen mold set at 150 DEG C to prepare specimens for evaluating mechanical properties.

PCT resin Glass
fiber Oxidation
stabilizator Lubricant A-1 A-2 B-1 B-2 B-3 B-4 B-5 B-6 Comparative Example 1 100 0 0 0 0 0 0 0 30 0.2 0.2 Comparative Example 2 0 100 0 0 0 0 0 0 30 0.2 0.2 Example 1 90 0 10 0 0 0 0 0 30 0.2 0.2 Example 2 80 0 20 0 0 0 0 0 30 0.2 0.2 Example 3 70 0 30 0 0 0 0 0 30 0.2 0.2 Example 4 90 0 0 10 0 0 0 0 30 0.2 0.2 Example 5 80 0 0 20 0 0 0 0 30 0.2 0.2 Example 6 70 0 0 30 0 0 0 0 30 0.2 0.2 Example 7 90 0 0 0 10 0 0 0 30 0.2 0.2 Example 8 80 0 0 0 20 0 0 0 30 0.2 0.2 Example 9 70 0 0 0 30 0 0 0 30 0.2 0.2 Example 10 90 0 0 0 0 10 0 0 30 0.2 0.2 Example 11 80 0 0 0 0 20 0 0 30 0.2 0.2 Example 12 70 0 0 0 0 30 0 0 30 0.2 0.2 Example 13 90 0 0 0 0 0 10 0 30 0.2 0.2 Example 14 80 0 0 0 0 0 20 0 30 0.2 0.2 Example 15 70 0 0 0 0 0 30 0 30 0.2 0.2 Example 16 90 0 0 0 0 0 0 10 30 0.2 0.2 Example 17 80 0 0 0 0 0 0 20 30 0.2 0.2 Example 18 70 0 0 0 0 0 0 30 30 0.2 0.2

(Unit: parts by weight)

Example  19 to 24: PCT  Preparation of resin composition

30 parts by weight of glass fiber, 0.2 part by weight of an oxidation stabilizer (AO-60 of ADEKA) and 0.2 part by weight of a lubricant (Hi-Lube of Sinwon chemical Co.) were added to two types of PCT resins as shown in the following Table 3, 4 parts by weight of the first other additive shown in Table 3 (AX8900 from Arkema Co., Ltd.) and 4 parts by weight of the second other additive (Licomont NaV101 from Clariant) were blended and then kneaded in a twin screw extruder (Φ: 40 mm, L / D = 44), and extruded to prepare pellets.

The pellets were placed in an extruder heated to about 295 DEG C and the molten resin composition was injected into an ASTM tensile specimen mold set at 150 DEG C to prepare specimens for evaluating mechanical properties.

PCT resin Glass fiber The first additive Second additive A-1 B-1 B-2 B-3 B-4 B-5 B-6 Example 19 80 20 0 0 0 0 0 30 4 4 Example 20 80 0 20 0 0 0 0 30 4 4 Example 21 80 0 0 20 0 0 0 30 4 4 Example 22 80 0 0 0 20 0 0 30 4 4 Example 23 80 0 0 0 0 20 0 30 4 4 Example 24 80 0 0 0 0 0 20 30 4 4

(Unit: parts by weight)

Test Example : PCT  Evaluation of physical properties of resin composition

The properties of the PCT resin compositions prepared in Examples 1 to 24 and Comparative Examples 1 and 2 were evaluated by the following methods, and the results are shown in Table 4.

(1) Minimum cooling time: In the preparation of the specimens of Examples 1 to 24 and Comparative Examples 1 and 2, the minimum time (injection cooling time) during which the composition injected into the ASTM tensile specimen mold solidified and stably separated from the mold was measured .

(2) Injection pressure: Each of the pellets prepared in Examples 1 to 24 and Comparative Examples 1 and 2 was placed in an injection machine, and the molten resin composition was injected into a mold to prepare a specimen, and the molten resin composition was filled in the mold The pressure of the maximum molten resin composition generated when the molten resin composition was produced was measured. The lower the injection pressure is, the better the flowability of the molten resin composition is.

(3) Tensile strength and tensile elongation: Measured according to ASTM D638 method.

(4) Impact strength: Izod notched type was measured by ASTM D256 method at a temperature of 25 ° C, and the thickness of the specimen used was 1/8 ".

Minimum cooling time [sec] Injection pressure [bar] The tensile strength
[kgf / cm ² ] Tensile elongation [%] Impact strength
[J / m] Comparative Example 1 15 35 750 1.5 35 Comparative Example 2 17 60 970 1.9 34 Example 1 16 29 850 2.3 39 Example 2 19 32 950 3.0 45 Example 3 20 38 990 4.6 60 Example 4 17 33 810 2.4 37 Example 5 19 31 930 3.6 42 Example 6 21 37 1010 4.9 85 Example 7 15 28 790 1.9 42 Example 8 18 31 930 2.8 54 Example 9 21 34 1090 4.5 77 Example 10 16 30 830 2.5 47 Example 11 19 35 960 4.3 62 Example 12 20 38 1150 7.2 97 Example 13 17 19 790 1.9 43 Example 14 18 20 970 2.8 55 Example 15 20 24 1090 4.0 70 Example 16 16 20 830 2.2 48 Example 17 18 23 950 3.1 64 Example 18 21 24 1150 4.3 79 Example 19 19 19 1195 3.9 69 Example 20 15 20 1300 4.2 72 Example 21 16 24 1270 5.3 87 Example 22 16 20 1380 6.7 95 Example 23 17 23 1285 5.5 76 Example 24 18 24 1350 6.1 69

Referring to Table 4, Examples 1 to 24 show improved tensile strength, tensile elongation and impact strength as compared with Comparative Examples 1 and 2, while showing injection cooling time and injection pressure similar to those of Comparative Examples 1 and 2 It is confirmed that a molded article can be provided.

Claims (8)

A first polycyclohexylenedimethylene terephthalate resin having a crystal melting point of 295 DEG C or higher and an intrinsic viscosity of 0.75 dL / g or less; And
A polycyclohexylenedimethylene terephthalate resin composition comprising a second polycyclohexylenedimethylene terephthalate resin having a crystal melting point of 280 DEG C or less and an intrinsic viscosity of 0.75 dL / g or more.
The method of claim 1, further comprising: mixing a first polycyclohexylenedimethylene terephthalate resin in an amount of 50 to 95 wt% and a second polycyclohexylenedimethylene terephthalate resin in an amount of 5 to 50 wt% Cyclohexylene dimethylene terephthalate resin composition.
The polycyclohexylenedimethylene terephthalate resin composition according to claim 1, wherein the first polycyclohexylenedimethylene terephthalate resin is polymerized using cyclohexane dimethanol having a trans isomer ratio of 70 mol% or more.
The polycyclohexylenedimethylene terephthalate resin composition according to claim 1, wherein the second polycyclohexylenedimethylene terephthalate resin is polymerized using cyclohexane dimethanol having a trans isomer ratio of 65 mol% or less.
The method of claim 1, wherein the second polycyclohexylenedimethylene terephthalate resin is selected from the group consisting of isophthalic acid, isophthalic acid ester compounds, ethylene glycol, 1,3-propanediol, 1,4-butanediol, and poly Propyleneglycol, and propylene glycol. 2. The polycyclohexylenedimethylene terephthalate resin composition according to claim 1,
The polycyclohexylenedimethylene terephthalate resin composition according to claim 1, further comprising at least one additive selected from the group consisting of fillers, pigments, oxidation stabilizers, lubricants, reinforcing agents and nucleating agents.
The polycyclohexylenedimethylene terephthalate resin composition according to claim 6, wherein the additive is included in an amount of 20 to 60 parts by weight based on 100 parts by weight of the total resin.
A molded article formed from the resin composition according to claim 1.