KR100622602B1 - polyester resin composition and the cable made of thereit - Google Patents

Abstract

In this invention, (a) the 1st resin component containing the copolymer of a polyester component and a lactone component; (b) a second resin component containing a polyester-based resin; a resin composition comprising: a polyester-based resin, wherein the weight fraction of the first component is 30 to 70% of the total weight of the resin composition; A wire comprising a composition and further comprising a conductor and at least one insulator layer formed around the conductor, wherein the at least one insulator layer comprises the polyester resin composition. Start the used wire. The polyester resin composition and the electric wire using the same according to the present invention, unlike the prior art mainly based on the polyester resin, is easy to add the additives, greatly reduce the possibility of hydrolysis, thereby improving heat resistance, showing a wide elastic region It is excellent in workability, impact resistance and heat resistance and oil resistance, and in particular, the resin copolymerized with the polyester component is blended again with the polyester resin without merely mixing the polyester component and the lactone resin, thereby deteriorating the heat resistance property and physical properties during long-term use. The effect of excluding the deterioration is achieved, and accordingly, it is required to meet the desired characteristics when applied to electric wires and the like.

Polyester, lactone system, copolymerization, hydrolysis, heat resistance, physical property degradation, electric wire

Description

Polyester-based resin composition and the wire using the same {polyester resin composition and the cable made of thereit}

The present invention relates to a polyester-based resin composition and an electric wire using the same, and in detail, a polyester-based resin by blending a resin obtained by copolymerizing them with a polyester-based resin without mixing only a polyester component and a lactone-based resin. It relates to a resin composition and an electric wire using the same.

Polyester-based resins, especially polyethylene terephthalate and polybutylene terephthalate, have excellent mechanical properties, heat resistance, chemical resistance, safety, and recyclability, and easily change properties and processability by changing monomers to be polymerized. In addition, the supply and demand of raw materials is easy, the production process is relatively simple, the cost-performance ratio is very high, and it has been widely applied for various purposes. Recently, due to the excellent electrical properties of polyester resin, It is also used a lot.

In particular, polybutylene terephthalate in polyester resins is more flexible because of two methylene parts in structure than polyethylene terephthalate, and has a higher glass transition temperature because the glass transition temperature is as low as 25 ° C. Since crystallization is faster than phthalate, it is recently applied in the engineering plastics field. In addition, a variety of additives have been used to increase the heat resistance or oxidation resistance, and to make a blend with a flexible resin in order to compensate for the weakness of the impact.

On the other hand, the production of thermoplastic elastomers using polyester resins is also a widely applied technique, and includes a crystalline part having rigidity and an amorphous part having elasticity at the same time to realize various physical properties according to the ratio of two parts. In this thermoplastic elastomer, since the crystal of the polyester portion acts as a physical crosslinking point, it exhibits the same behavior as the elastomer at room temperature. When the temperature is raised above the melting point of the crystal, melt processing becomes possible. In general, it is known that as the ratio of amorphous portions increases, elasticity and flexibility increase, and moldability, mechanical strength, dimensional stability, and oil resistance decrease.

In the use of such polyester-based resin, in order to improve the physical properties of the polyester-based resin and to make a material that meets the desired purpose, the other resin is mixed with the polyester-based resin, and a technique for adding a flame retardant and antioxidant, etc. This is widely spread, and accordingly, there is a case where a compound is formed and applied to a technology for making various products through a general process such as injection or extrusion, in particular, an electric wire.

That is, when the resin is applied to the actual process for the manufacture of the product, in order to improve the physical properties and reduce the price, various resins are mixed and various additives are included at the same time to form the compound. When using a polyester resin such as len terephthalate alone, there is a limit to the application of various additives to improve the flame retardancy, antioxidant properties, processing characteristics, etc. Will not serve the purpose. In addition, even if a certain amount of other resins, such as polyolefin or thermoplastic elastomer, is added to the polyester resin, the compatibility is drastically reduced or the physical properties are lowered, and the addition of various additives is limited.

Therefore, in order to overcome such a problem, in particular, a technique of adding a good compatibility lactone resin to a polyester resin as an attempt to improve flexibility and processability while maintaining the physical properties of the polyester resin is described in some documents. Is shown.

As the lactone-based resins, Dow's 'ton' and Solvay's 'kappa' are commonly used.The lactone-based resin is less toxic, facilitates processing in extrusion and injection, and has high compatibility with other resins. In addition, it is known to contribute to the mixing and dispersion of additives, and in particular, polylactone is widely used for improving physical properties because it is flexible and has a low melting point and easy mixing with other resins.

The study on the physical property improvement of polyester-type resin using such lactones is as follows, for example.

That is, US Pat. No. 3,835,089 and European Patent No. 57,415A2 describe examples of introducing an inorganic additive such as phosphite to a blend of polybutylene terephthalate and polycaprolactone.

In addition, US Pat. No. 5,248,713 discloses the introduction of carbodiimide and phosphite inorganic additives to a blend of polybutylene terephthalate and polycaprolactone, wherein the polybutylene terephthalate is at least 30% or more by weight of the total composition, It is disclosed that at least 3% polycaprolactone, at least 0.05-10% carbodiimide, and at least 0.05-10% aliphatic phosphite are mixed.

US Pat. No. 5,660,932 describes an example of adding magnesium hydroxide to a blend of polybutylene terephthalate and a polyetherimide-siloxane copolymer based on the oxygen index. More recently, US Pat. No. 5,824,412 describes polybutylene. Blends of terephthalate with grafting agents, ethylene copolymers and thermoplastic elastomers are shown.

According to such a conventional technique, when adding a lactone resin, a blend is blended with a polyester resin or a thermoplastic elastomer or other resin as a third component to form a blend, and a flame retardant and an antioxidant are added thereto. The method is mainly disclosed. Meanwhile, in order to compensate for the problem of the polyester-based resin which is susceptible to hydrolysis, a case where a certain amount of a hydrolysis inhibitor such as carbodiimide is added is also described.

However, in general, the polyester-based resin is present in a range in which the temperature required for melt processing exceeds 200 ° C, whereas the melting point is found at 60 ° C for polylactone. Therefore, when making blends using various kinds of resins, a problem arises in that processing becomes difficult if the difference between the proper processing temperatures of the resins is large, and in addition, excessive heat is applied to the resins having low processing temperatures. May cause. And even if processing is done through this method, it has a negative result in terms of long-term use.

The likelihood of such a problem can also be predicted by means of a thermal analysis method such as DSC, which is repeated several times by heating the blend above the temperature at which the polyester resin melts completely and then cooling it to below room temperature, regardless of the cooling conditions. On the graph it can be seen that the peak of the lactone-based resin gradually decreases and finally hardly appears. This means that excessive heat causes decomposition or change of properties of the lactone-based resin, and in practice, it leads to deterioration of various physical properties including tensile strength and elongation.

In addition, in the case of a resin composition composed of a blend of a polyester-based resin and a small amount of other resin, and then added a flame retardant, etc., even if physical properties at room temperature are realized, the heat resistance test is due to the fundamental hydrolysis vulnerability of the polyester resin. After passing through, there is a problem that a sudden decrease in physical properties is observed.

In other words, due to the structural properties of the polyester, hydrolysis occurs easily in an acidic or basic environment, and the reaction temperature is very fast at high temperatures, and metal hydroxides, which are frequently used as flame retardants, catalyze the hydrolysis reaction. As a result, the polyester resin-based composition comprising a simple blend composition of the lactone and the polyester-based resin composition as a result, even if a hydrolysis inhibitor is used, the problem becomes very weak in terms of heat resistance There is.

Therefore, the present invention has been made to solve the above problems,

An object of the present invention is a polyester resin composition which is easy to add an additive, exhibits a wide elastic region, is excellent in workability, impact resistance, oil resistance, and the like, and in particular, has no deterioration in heat resistance and can prevent deterioration of physical properties during long-term use. And to provide a wire using the same.

The object of the present invention described above is (a) a first resin component containing a copolymer of a polyester component and a lactone component; (b) a second resin component containing a polyester-based resin; a resin composition comprising: a polyester-based resin, wherein the weight fraction of the first component is 30 to 70% of the total weight of the resin composition; Achieved by the composition.

The polyester resin composition preferably has a weight fraction of the first resin component greater than that of the second resin component, and the polyester resin composition may include a polyester of the first resin component. It is preferable that it is polybutylene terephthalate, and the polyester resin of the said 2nd resin component is polybutylene terephthalate, It is preferable that the said lactone is caprolactone, The said polyester resin composition is the whole said resin composition It is preferable to further include magnesium hydroxide of 10 to 40% by weight with respect to the weight ratio, wherein the polyester resin composition further comprises an antioxidant and a polycarbodiimide at a weight fraction of 10% or less with respect to the entire resin composition. It is preferable.

The above object of the present invention is also a wire comprising a conductor and at least one insulator layer formed around the conductor, wherein at least one insulator layer is made of the polyester resin composition. It is achieved by the electric wire using the system resin composition.

And the said electric wire has two insulator layers, It is preferable that an outer layer insulator layer or an inner layer insulator layer consists of said polyester-type resin composition.

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

The present invention is to overcome the various problems that occur when the conventional polyester-based resin is applied, the copolymer resin of the polyester component and lactone component as a main component, and mixed with the polyester-based resin, various We propose a method of adding an additive. Furthermore, in mixing the said copolymer resin and the said polyester-type resin, the appropriate mixing ratio which can ensure especially heat resistance is confirmed and shown.

That is, the polyester resin composition according to the present invention basically uses a first component resin containing a copolymer resin of a polyester component and a lactone component, and a second component containing a polyester resin in the first component resin. The resin is suitably mixed, wherein the weight fraction of the copolymer resin as the first component with respect to the entire resin composition is 30 to 70%, and various additives are added to the blend of the first component resin and the second component resin. It is produced in a way.

First, the copolymer resin of the polyester component and lactone component which are 1st component resin applies a polyethylene terephthalate or a polybutylene terephthalate as a polyester component, for example, gamma caprolactone or a polycapro as a lactone component, for example. Apply lactone.

In the copolymer resin, the weight fraction of the lactone component is preferably 10 to 60%, more preferably 15 to 45%. As such, the weight fraction of the lactone component in the copolymer resin may be changed or the weight fraction of the polyester component in the copolymer resin may be changed to cause a change in physical properties. When the ratio of the lactone component is too high or too low, the heat resistance may decrease or the flexibility and The improvement of the same physical property will not be expressed. The use of the copolymer resin of the polyester component and the lactone component presented in the present invention is superior in heat resistance, weather resistance and chemical resistance and easy processing compared to the conventional method of simply blending and applying the polyester resin and the lactone resin. to provide. In addition, even if the weight fraction of the lactone component changes within a certain range, the melting point of the copolymer resin is maintained at 200 ° C. or higher, so it is convenient to knead and mix with other resins, while applying a blending method as in the prior art. The melting point of and the polylactone resin shows a large difference between 200 ° C. and 60 ° C., respectively, which makes processing very difficult and causes problems in that excessive heat is applied to the polylactone resin. This extreme heat history has negative consequences not only in the short term but also in terms of long term use.

In addition, the weight fraction of the copolymer resin which is the first component with respect to the entire resin composition is 30 to 70%, preferably 35 to 60%, in terms of heat resistance, as confirmed from the examples below. When the weight fraction of the copolymer resin is too low, the heat resistance tends to decrease. On the contrary, when the copolymer resin of too high weight fraction is contained, the mechanical properties and the electrical insulation resistance are deteriorated. Selection of is necessary.

At this time, it is more preferable that the weight fraction of the copolymer resin as the first component is greater than the weight fraction of the polyester resin as the second component because it can implement excellent physical properties in terms of heat resistance.

The polyester-based resin of the second component is basically composed of polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and modified resins having modified molecular weight or viscosity in order to improve physical properties and weak properties Also included, polytetramethylene terephthalate (PTMT), polycyclohexylenedimethylene terephthalate (PCT) and polyethylene naphthalate (PEN) can be applied.

It is preferable that the weight fraction of the polyester resin which is a 2nd component with respect to the whole resin composition is 5 to 60%, More preferably, it is 10 to 50%. Variation of the polyester-based resin causes a change in physical properties together with the first component copolymerized resin.

In the present invention, as an additive, a flame retardant for securing flame retardancy, an antioxidant for improving thermal stability and antioxidation, and a hydrolysis inhibitor for compensating for hydrolysis vulnerabilities common to polyester resins, and other flow control The polyfunctional acrylic resin etc. to apply are suitably applied.

First, the flame retardant applied in the present invention can have a synergistic effect by using them alone or in combination as appropriate, such as metal hydroxide, melamine-based and phosphorus-based. The weight fraction of the flame retardant relative to the total resin composition is preferably 5 to 45%, more preferably 10 to 40% in order to ensure flame retardancy. Particularly, in the case of using a metal hydroxide flame retardant, since it contains a probability that can cause a hydrolysis reaction which is a fundamental vulnerability of the polyester resin, excessive use may cause a sharp decrease in mechanical properties and the like.

The antioxidant is heat-resistant and by applying a butyl phenyl phosphite-based, hydroxy phenol propionate-based, hydroxyphenyl propionamide-based, hydroxybenzyl triazine-based, pentaerythritol diphosphite-based alone or in an appropriate combination Antioxidant properties can be enhanced. In view of such heat resistance and antioxidant reinforcement, the weight ratio of the antioxidant to the total resin composition is preferably 1 to 10%, and the use of excessive and excessive amounts causes a negative effect on the improvement of physical properties.

The hydrolysis inhibitor is an additive that inhibits the occurrence of a reaction by separating a terminal portion in which hydrolysis occurs in a polyester, and a material such as an aromatic polycarbodiimide may be applied. In the case of the present invention, by the application of the copolymer resin as the first component, the hydrolysis is considerably suppressed, and if necessary, the polycarbodiimide-based hydrolysis inhibitor can be used in 0 to 5% by weight of the total resin composition. . Such hydrolysis inhibitors are not only very expensive, but also do not bring about an improvement in physical properties even when a suitable amount is added.

On the other hand, when the melt index of the polyester resin is determined to be excessive flowability, it can be adjusted appropriately by adding a multifunctional acrylic resin, such as a functional group such as epoxy, to the entire resin composition of such a multifunctional acrylic resin The weight fraction is preferably 0 to 5% so as to have good flowability if necessary. Since most of these polyfunctional acrylic resins do not have a high melting point of about 100 ° C., an appropriate amount of the polyfunctional acrylic resin needs to be used in terms of heat resistance.

The resin composition devised in the present invention has a copolymer component of a polyester component and a lactone component as a main component, mixed with a polyester-based resin, and at this time, by deriving and applying an appropriate ratio of the copolymer resin in the total resin composition, the polyester Compared with the prior art which adds other components by only blending mainly based on the resin, the addition of the additives is easier, and the possibility of hydrolysis is greatly reduced, and the heat resistance is greatly improved. In particular, when the copolymer of the polyester component and the lactone component is applied, it is possible to exclude the possibility of deterioration of the heat resistance and the deterioration of physical properties in the long-term use, which is found in the case of simply mixing the polyester component and the lactone resin.

The copolymer resin of the polyester component and the lactone according to the present invention uses polyethylene terephthalate or polybutylene terephthalate as the polyester component, and gamma caprolactone or polycaprolactone is applied as the lactone component. Therefore, it shows a wide elastic range and is excellent in workability, impact resistance, heat resistance and oil resistance.

Next, the electric wire using the polyester resin composition which concerns on this invention is explained in full detail.

The polyester resin composition configured as described above may be applied to various applications through processing methods such as injection or extrusion, in which case mechanical properties, chemical resistance, heat resistance, and the like are secured.

In this invention, the said polyester resin composition was applied to manufacture of an electric wire. That is, the electric wire according to the present invention is a conventional electric wire having a conductor and one or more insulator layers wrapped around the conductor, wherein the polyester resin composition is coated on the conductor or insulator layer through an extrusion process. Accordingly, at least one or more insulator layers of one or more insulator layers surrounding the conductor are made of the polyester resin composition according to the present invention.

At this time, when the electric wire consists of a double insulator layer of an outer layer and an inner layer, the conventional polyester resin composition is applied to an outer insulator layer, and the polyester resin composition which concerns on this invention is applied to an inner layer insulator layer. In the case where the electric wire is composed of a double insulator layer of the outer layer and the inner layer, the polyester resin composition according to the present invention described above is applied to the outer layer insulator layer, and the conventional insulator layer It is possible to apply a polyester-based resin composition.

Hereinafter, the present invention will be described in more detail by explaining preferred embodiments of the present invention. However, the present invention is not limited to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only common to those skilled in the art to complete the present disclosure. It is intended to facilitate the implementation of the invention to those with knowledge.

EXAMPLE

The polyester resin composition according to the present invention is shown in three examples with different compositions, and the resin composition for comparing physical properties with the polyester resin composition according to the present invention is shown as three comparative examples.

The following Table 1 shows the prescription of each Example and a comparative example.

  Fraction (wt%)                                                  ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Polyester-Lactone Copolymer 45 32 58 - 10 22 Polyester Thermoplastic Elastomer - - - 24 - - Polyester resin 28 41 14 56 70 58 Metal hydroxide flame retardant 22 20 22 15 15 15 Melamine flame retardant - 2 - - - - Antioxidant 3 3 3 3 3 3 Hydrolysis inhibitor 2 2 2 2 2 2 Polyfunctional resin - - One - - -

In each Example and Comparative Example, the included components were kneaded for 15 minutes at a temperature range of 230 ~ 250 ℃ using equipment such as an internal mixer, and tested the tensile strength, elongation and oil resistance in the specimen state.

Mechanical properties at room temperature were tested according to ASTM D 638 and 639.

Oil resistance was determined by measuring the rate of change of the width after soaking in ASTM No. 2 oil maintained at a temperature of 100 ℃ for 70 hours.

In the heat resistance test, the samples were placed in an oven at 180 ° C. for 1 week, and then mechanical properties were measured in the same manner as at room temperature.

In consideration of various specifications, the mechanical properties were based on the tensile strength of 2.5kgf / cm ² or more at room temperature and 100% or more at room temperature elongation. Mechanical properties after heating to determine the heat resistance was also used the same criteria as at room temperature.

Table 2 shows the physical properties of each Example and Comparative Example measured by the above method.

Item unit Example Comparative example One 2 3 One 2 3 Room temperature tensile strength kgf / cm ² 3.1 3.6 2.9 4.3 3.9 3.7 Normal temperature elongation % 285 133 556 111 103 109 Width change rate after infiltration % 0.1 0.2 0.1 0.1 0.2 0.1 Tensile strength after heating kgf / cm ² 3.9 4.8 2.9 5.9 5.2 5.0 Elongation after heating % 113 106 219 31 68 89

As shown in Table 2, the test results showed that the mechanical properties at room temperature exceeded both the Examples and Comparative Examples, but the tensile strength was relatively low in the Comparative Example compared to the Examples, while the tensile strength was relatively low.

In addition, as a result of measuring the mechanical properties after heating for 1 week at 180 ℃, as shown in Table 2, the tensile strength and elongation in the Example showed suitable properties, but the comparative example showed a result that the elongation was greatly reduced. In oil resistance, no problem occurred in all samples.

In addition, as a result of experiments by changing the mixing ratio of the polyester component and the lactone copolymer resin and the polyester resin (Examples and Comparative Examples 1 and 2), the weight fraction of the copolymer resin to the resin composition in the state of the usual additives In the examples (examples) of about 30% or more, the results satisfying the above criteria were obtained.

When the weight fraction of the copolymer resin falls below that, there is a problem in heat resistance, and in particular, it was confirmed that the elongation after heating is very low. On the other hand, when the weight fraction of the copolymer resin is 70% or more, the tensile strength was lowered and it was confirmed that the standard was not met.

Accordingly, by mixing the polyester resin and the lactone component copolymer resin and polyester, by mixing in an appropriate ratio, it can be concluded that desirable characteristics in heat resistance and physical properties are achieved.

As described above, the resin composition according to the present invention is generally based on a blend in which a polyester resin is appropriately mixed with a copolymer resin of a polyester component and a lactone component, and is composed of a form in which various additives are added thereto. Compared with the conventional resin composition which blends other resins mainly on ester resin, it is excellent in heat-resistance and physical properties, especially the advanced resin composition which changes the weight fraction of the polyester component and lactone component in copolymer resin It causes a change in physical properties, and based on this, it is possible to set the lowest value of the resin weight fraction for the expression of specific physical properties.

In addition, the resin composition according to the present invention may be applied to various applications through processing methods such as injection or extrusion based on suitable physical properties as described above, and in particular, may be applied to shapes such as insulators or other electronic components of electric wires.

The polyester resin composition and the electric wire using the same according to the present invention, unlike the prior art mainly based on the polyester resin, is easy to add the additive, greatly reduce the possibility of hydrolysis, heat resistance is improved, and wide elastic area It is excellent in workability, impact resistance and heat resistance and oil resistance, and in particular, by blending the resin copolymerized with the polyester resin again without merely mixing the polyester component and the lactone resin, the lowering of the heat resistance characteristics and the long-term use The effect of excluding the deterioration of the physical properties is achieved, and thus the desired characteristics when applied to the electric wire and the like.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (8)

(a) a first resin component containing a copolymer of a polyester component and a lactone component; (b) a second resin component containing a polyester resin; The weight ratio of the first component to the total weight of the resin composition is 30 to 70%, the weight fraction of the first resin component is larger than the weight fraction of the second resin component. delete The method of claim 1, The polyester resin composition of the said 1st resin component is polybutylene terephthalate, and the polyester resin of the said 2nd resin component is at least polybutylene terephthalate, The polyester resin composition characterized by the above-mentioned. delete The method of claim 1, wherein the polyester resin composition, A polyester-based resin composition, further comprising magnesium hydroxide at a weight fraction of 10 to 40% based on the total weight of the resin composition. The method of claim 5, wherein the polyester resin composition, A polyester-based resin composition, further comprising an antioxidant and a polycarbodiimide at a weight fraction of 10% or less based on the total weight of the resin composition. A wire comprising a conductor and at least one insulator layer formed around the conductor, At least one insulator layer consists of the polyester-based resin composition of any one of Claims 1, 3, 5, or 6, The wire using the polyester-based resin composition characterized by the above-mentioned. The method of claim 7, wherein the wire, It has two insulator layers, The outer layer insulator layer or an inner layer insulator layer consists of the polyester-type resin composition of any one of Claims 1, 3, 5, or 6. Electric wire using ester resin composition.