KR20010018352A - Composition of thermoplastic polyesteric resin improved mechanical strength - Google Patents

Abstract

PURPOSE: Provided is a polyester-based thermoplastic resin composition which is excellent at mechanical character such as tensile strength, elongation and bending strength by blending polyester resin with polyamid resin. CONSTITUTION: The polyesters thermoplastic resin composition is characterized by comprising; polyester resin; polyimide resin; and copolymer that is grafted epoxy resin on polymethylmethacrylate resin.

Description

Polyester-based thermoplastic resin composition with improved mechanical strength {COMPOSITION OF THERMOPLASTIC POLYESTERIC RESIN IMPROVED MECHANICAL STRENGTH}

The present invention relates to a thermoplastic polyester resin composition, and more particularly, to a thermoplastic resin composition in which a mechanical alloy of a polyester resin is improved by blending a polyamide resin with a polyester resin to improve the mechanical strength of the polyester resin. It is about.

Polyester resin is a general term for high molecular compound having ester bond in the molecule, and the bond between carboxyl group and hydroxy group is the main axis. It is a resin that balances mechanical strength, heat resistance, chemical resistance, electrical properties, precision moldability, etc. . These polyester resins are very low in water absorption and have excellent dimensional stability, and thus are widely used in electric, electronic parts, automotive parts, general industrial materials, and other fields requiring high functionality.

However, polyester resins have a problem in that, when heated in a state where the specific gravity is relatively high and water coexists, the ester bond in the molecular structure is hydrolyzed while being broken under the influence of water under high temperature.

On the other hand, polyamide is a generic term for a high molecular compound containing an amide bond in the molecule, and since it has a hydrogen bond in the molecule, it has excellent mechanical properties, particularly impact resistance, and generally has a crystallinity of about 20 to 30%. It is a plastic and has excellent friction resistance, abrasion resistance, chemical resistance and oil resistance, and high melting point.

As a method of modifying the properties of such polymer materials, copolymers, graft copolymers, block copolymers, etc., which introduce heterogeneous structural units or functional groups into the polymers themselves, have been developed, and at least two kinds of polymer materials having a certain degree of affinity with each other. Polymer blend technology has been developed to mix and obtain a solid solution. Polymer blend refers to the homogeneous mixing of two or more unmixed or blended polymers for the purpose of imparting crude or special properties.

Of these polymer materials, copolymers and graft polymers have excellent compatibility with other polymers to easily achieve the purpose of polymer modification. However, physical, chemical and electrical properties of the homopolymer, which is a component of the polymer, The back gradually decreases. Therefore, in order to fully utilize their characteristics, it is necessary to use plastics, resins, etc., all of which are homopolymers or physically close to homopolymers.

In order to meet these needs, it is almost impossible to synthesize homopolymers having excellent physical properties in all aspects, and thus, application of non-uniform polymer blends is required. In this mixing system, the mixture is mixed with little or little compatibility, and thus exhibits characteristics not seen in other examples. Thus, mixing between polymers that have been previously considered impossible is enabled, and the use thereof is significantly increased.

Therefore, blending the two kinds of resins (blending) to supplement the advantages and disadvantages of the two resins may be applicable to more applications, but due to lack of compatibility, the two resins alone cannot be extruded but also extruded. Even in this case, peeling phenomenon occurs in most cases.

In order to solve this problem, a third material, called a compatibilizer, is added to prepare a polymer blend of polyester and polyamide resin. It should satisfy the point that there should be no delamination while maintaining the properties of the basic resin.

Japanese Patent Application No. Hei 6-137961 discloses a plastic composition blended with polyester and polyamide, which according to 100 parts by weight of polyester polymer, 60 to 90 parts by weight of polyamide, 0.05 to 5 parts by weight of maleic anhydride and By blending and melting 0.01 to 5 parts by weight of peroxide, a compound having improved heat resistance and water absorption can be obtained. However, the compound has many swellings during extrusion, resulting in poor molding processability and low elongation at break. Since the properties are not satisfactory, there is a problem that the usable range is greatly reduced.

In order to solve the above problems, the present invention, when blending polyester and polyamide, is present at the interface between polyester resin and polyamide resin as a compatibilizer, which is a third material, to increase the adhesion between the two resins and The present invention provides a polyester resin composition having improved compatibility and improved mechanical strength by using a material without peeling while maintaining physical properties of the resin.

The present invention to achieve the object as described above,

a) polyester resin;

b) polyamide resin; And

c) Graft copolymer in which epoxy resin is grafted to polymethylmethacrylate resin

It provides a thermoplastic resin composition, characterized in that consisting of.

The polyester resin is an aromatic polyester resin which is condensation-polymerized by melt polymerization from a terephthalic acid or a terephthalic acid methyl ester and a glycol component having 2 to 10 carbon atoms.

Such aromatic polyester resins include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate (polytetramethylene terephthalate), polyhexamethylene terephthalate, polycyclohexane dimethylene terephthalate, and the like. In this, it is preferable to use polybutylene terephthalate or polyethylene terephthalate.

It is preferable to use 10-90 weight part of said polyester resin, More preferably, it is more preferable to use 30-80 weight part.

The polyamide resin can be used not only a single compound but also a copolymer. Polyamide resins are obtained by multiple condensation of bifunctional monomers, for example by condensation of diamines and dicarboxylic acids and polymerization of lactams such as ε-caprolactam.

Dioic acid (diacid) used to prepare such a polyamide resin includes carboxylic acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecane dicarboxylic acid, Terephthalic acid, isophthalic acid, phthalic acid and the like, and terephthalic acid, isophthalic acid and phthalic acid are preferred.

In addition, aliphatic diamines and aromatic diamines may be used as the diamine, and examples of the aliphatic diamine include hydrazine, ethylene diamine, 1,4-butane diamine, hexamethylene diamine, 1,8-octane diamine, piperazine, and the like. Alternatively, aminocarboxylic acids may be optionally used, and as aromatic diamines, ο-phenylene diamine, 2,4-diaminotoluene and 4,4-methylene dianiline polyamide may be prepared by known methods. .

Polyamides are prepared by direct amidation, low temperature polycondensation of diamines and dibasic chlorides, ring-opening polymerization of lactams, addition of amines to activated double bonds, polymerization of isocyanates and the reaction of formaldehyde with dinitrayl, etc. Can be.

Polyamides that can be used in the present invention include poly hexa methylene adiamide (polyamide-6,6), poly (ε-caprolactam) (polyamide-6), polypropiolactam (polyamide-3), polypyrrole Lidone (polyamide-4), poly (ω-enandamide) (polyamide-7), polycapryllactam (polyamide-8), poly (ω-undecane amide) (polyamide-11), poly Laurolactam (polyamide-12), polyhexamethylene terephthalamide (polyamide-6T), polytetramethyleneadipamide (polyamide-4,6), and copolymers, and polyhexamethylene adipamide ( Polyamide-6,6) and poly (ε-caprolactam) are preferred, and more preferably poly (ε-caprolactam) is most preferred.

It is preferable to use 10-90 weight part of said polyamide resin, More preferably, it is more preferable to use 20-70 weight part.

When blending the polyester resin and the polyamide resin, the compatibility of both resins is insufficient, so that the peeling phenomenon and the swelling phenomenon occur during molding such as injection and extrusion, and thus molding process is impossible, thereby increasing the adhesive strength of the two resins. In addition, it is used by adding a compatibilizer that can maintain the physical properties of the base resin.

As the compatibilizer which can be used in the present invention, a compound capable of bonding with a polyamide resin and a polyester resin is preferable. As such a material, it is preferable to use a graft copolymer in which an epoxy resin is grafted to a polymethyl methacrylate by a free radical reaction.

The graft copolymer has a methacrylate group and an epoxy group which can be bonded to a polyester resin and a polyamide resin, and in the case where the amide group of the polyamide resin and the epoxy group of the graft copolymer are bonded, the methacrylate of the graft copolymer The group is combined with the polyester resin, and vice versa.

The bonding degree of the epoxy group and the methacrylate group in the graft copolymer is greater in the epoxy group, and it is determined that the bonding position of the methacrylate group is determined by which epoxy group is bonded.

The epoxy resin and the polymethyl methacrylate graft copolymer are preferably used in an amount of 0.5 to 20 parts by weight.

A usual additive can be further used for such a thermoplastic resin composition. The additives include fillers, reinforcing fibers, stabilizers, pigments and dyes, plasticizers, mold release agents and antistatic agents.

Fibers for reinforcement include glass, carbon, aromatic polyamides and thermophilic liquid crystalline polymer fibers with sufficiently high melting points; fillers include talc, calcium carbonate, wollastonite, kaolin, mica, barium sulfate, titanium dioxide and Silicates.

The thermoplastic resin composition first mixes 10 to 90 parts by weight of a polyester resin having an intrinsic viscosity of 1 to 1.5 and 10 to 90 parts by weight of a polyamide resin, and adds a small amount of a lubricant and a stabilizer to the mixed resin. Then, 0.5 to 20 parts by weight of a polymethyl methacrylate resin grafted with an epoxy resin is added and mixed with a compatibilizer. This mixing uses a conventional banbury mixer. Banbury mixer is a device that mixes the input compounding material by rotating two mixing motors in the reaction direction in the sealed case, and the mixing effect is remarkably because the mixing is performed under pressure into the compounding material by pressurization. Big.

The mixture is extruded using a single screw or twin screw extruder to make pellets.

The thermoplastic resin composition thus prepared has various properties such as strength characteristics of polyester resin, in particular tensile strength, elongation of polyamide, flexural elasticity, and the like, and thus can be applied to various applications. It can be widely used in industrial materials and other fields requiring high functionality, and is a connector, which is a connection device for electrical connection between circuits and devices that require various characteristics such as molding characteristics, electrical characteristics, mechanical characteristics, and heat resistance. This is useful for manufacturing connectors.

Hereinafter, preferred examples and comparative examples are presented to help understand the present invention. However, the following examples are only for the understanding of the present invention and the present invention is not limited to the following examples.

Example 1

30 parts by weight of PBT resin ("LG" chemical product, trade name LUPOX SV-1080) with an inherent viscosity of 1.15 and 70 parts by weight of nylon 6 (ALLIED SIGNAL), brand name CAPRRON 8200) with FAV 70 3 parts by weight of a graft copolymer of polymethyl methacrylate resin grafted with an epoxy resin (TOGAOSEI Co., Ltd., product name RESEDA 301) is added to the composed resin with a small amount of a lubricant and a stabilizer. The mixture was added, mixed and extruded to prepare pellets of the composite resin. The extruder was a twin extruder (manufactured by WARNER & PHLEIDERER), and the pellets thus prepared were dried at 110 ° C for 4 hours and then injected at a molding temperature of 250 ° C and a mold temperature of 60 ° C with an injection capacity of 3 oz. It was produced as a test specimen.

The prepared specimens were left to stand at 23 ° C. for 48 hours and then physical properties were measured according to ASTM. The results are shown in Table 2.

Example 2

Except that 30 parts by weight of PBT resin ("LG" chemical product, LUPOX HV-1010) having an intrinsic viscosity of 1.0 was used, and the results were shown in Table 2 in the same manner as in Example 1.

Comparative Example 1

Using only 100 parts by weight of a PBT resin (“LG” chemical product, LUPOX HV-1010) having an inherent viscosity of 1.0, the resultant was tested in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2

The test was carried out after molding except for the compatibilizer RESEDA 301 in Example 1.

Comparative Example 3

In Comparative Example 2, the composition ratio of PBT resin and nylon 6 was tested by changing the blending ratio to 70 parts by weight of PBT resin and 30 parts by weight of nylon 6.

Comparative Example 4

In Example 1, instead of the compatibilizer RESEDA 301, the basic resin was HDPE and the functional group was maleic anhydride (manufactured by UNIROYAL CHEMICAL, trade name POLYBOND 3009) and peroxide (manufactured by AKZO CHEMICAL) Percardox 14) was tested by adding 5 parts by weight and 3 parts by weight, respectively.

Table 1 shows the component ratios of the thermoplastic resin compositions prepared in Examples 1 and 2 and Comparative Examples 1 to 4.

Table 1

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 A LUPOX SV1080 30 parts by weight - - 30 parts by weight 70 parts by weight 30 parts by weight LUPOX HV1010 - 30 parts by weight 100 parts by weight - - - B Nylon 6 70 parts by weight 70 parts by weight - 70 parts by weight 30 parts by weight 70 parts by weight C Epoxy-g-PMMA 3 parts by weight 3 parts by weight - - - - D POLYBOND 3009 5 parts by weight E Peroxide 3 parts by weight

TABLE 2

Item unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile Strength Elongation Flexural Strength Flexural Modulus kg / ㎠% kg / ㎠kg / ㎠ Excellent Excellent Excellent Property evaluation is impossible due to large amount of peeling during injection molding Extrusion is impossible due to severe swelling phenomenon during extrusion Moldable Levels

As shown in Table 2, Comparative Example 1 when blending a polybutylene terephthalate resin and nylon 6 resin using a polymethyl methacrylate resin grafted epoxy resin as a compatibilizer in Examples 1 and 2 The mechanical strengths such as tensile strength, elongation, flexural strength, and the like were superior to those of the polybutylene terephthalate resin alone, and in particular, the tensile strength showed more excellent physical properties. In addition, when the compatibilizer is not used as in Comparative Example 2 and Comparative Example 3, it can be seen that the extrusion property is impossible or the physical properties cannot be measured due to a large amount of peeling phenomenon during injection molding. It can be seen that the peeling phenomenon during the swelling and injection molding shows poor molding processability, and in particular, in the case of elongation, it is 30 to 40 times lower than in the case of the embodiment of the present invention.

Therefore, when blending a polyester resin and a polyamide resin using the compatibilizer according to the present invention, its mechanical properties, in particular, its tensile strength is excellent, its moldability, etc. are excellent, and it has many resin properties. It is possible to provide a thermoplastic resin composition applicable to.

Claims (5)

a) polyester resin; b) polyamide resin; And c) The thermoplastic resin composition, wherein the epoxy resin is made of a graft copolymer grafted to a polymethyl methacrylate resin. The method of claim 1, The thermoplastic resin composition wherein the polyester resin is polybutylene terephthalate or polyethylene terephthalate. The method of claim 1, The polyamide resin is polyhexamethyleneadipamide, poly (ε-caprolactam), polypropiolactam, polypyrrolidone, poly (ω-enandamide), polycapryllactam, poly (ω-undecaneamide) And a polyamide resin selected from the group consisting of polylaurolactam (nylon 12), polyhexamethylene terephthalamide, polytetramethylene adipamide, and copolymerization thereof. The method of claim 1, 10 to 90 parts by weight of the polyester resin, 10 to 90 parts by weight of the polyamide resin, and 0.5 to 20 parts by weight of the graft copolymer in which the epoxy resin is grafted to the polymethylmethacrylate resin is used. Thermoplastic resin composition. A connector made of the thermoplastic resin composition of claim 1.