KR100839532B1 - Polyamide resin composition with excellent flexibility - Google Patents

Abstract

The present invention relates to a flexible polyamide resin composition, 20 to 50 parts by weight of an e-rubber grafted maleic hydride with respect to 100 parts by weight of polyamide resin and 10 to 40 parts by weight of dimerized fatty acid (Dimerized Fatty Acid) It is characterized in that the addition is included.

The present invention is particularly useful as a material for making mandel required to make a pipe or tube for bending because of its excellent flexibility and excellent extrusion resistance.

Flexibility, Extrusion, Mandrerel, Polyamide, Resin Composition, Impact Resistance.

Description

Polyamide resin composition with excellent flexibility

The present invention relates to a polyamide resin composition having excellent flexibility, and more particularly, to a polyamide resin composition which is useful as a material for mandelels required to make a pipe for bending due to its excellent flexibility and impact resistance and being capable of extrusion molding.

Conventionally, mandrel required for molding rubber hoses and the like has been mainly manufactured using nylon 12 and the like. Nylon 12 has excellent flexibility, but is expensive, so the industry has been using nylon 6 in recent years.

In general, polyamide resin is a material widely used for its excellent mechanical properties. Up to now, polyamide resins have been commonly used to manufacture products through injection molding processes, or have molded products such as fibers, monofilaments, and sheets by extrusion methods. However, the product manufactured by such a molding method has a disadvantage in that it is difficult for molding an extrusion product for bending that requires flexibility. The characteristics of plastic pipes or tubes are light, flexible and free from corrosion, which requires proper melt strength and flexibility in forming.

Melt strength not only enables molding, but also plays a key role in uniformizing the thickness of the pipe or tube being molded. Flexibility is an advantage of plastic pipes and tubes in particular.

 As a material for pipes and tubes, plastics have been steadily developed mainly in the early days of olefin polymers, and now various shapes of products can be molded. Recently, developments using gas barrier properties, which are characteristics of polyamide resins, have been actively developed. to be. In most cases, however, applications are centered around polyamides 11 and 12 in tubes and pipes, and polyamide 6 is currently undergoing a lot of effort.

As such a prior art, US Patent No. 5,408,000 proposes a polyamide resin composition which can be extruded by adding various kinds of ethylene copolymers and modified polytetraproloethylene to a polyamide resin, and US Patent No. 4,987,168. Has proposed a polyamide resin composition in which polyethylene / polypropylene copolymer is added to polyamide 6 as an impact agent, caprolactam is added as a plasticizer, and carbodiimide is added as a thickener.

Korean Patent No. 10-0846491 proposes a method of improving the flexibility of a polyamide resin composition by adding a phosphorus-based nucleating agent at the time of polymerization of the polyamide resin. In order to improve the flexibility, a method of blending a benzenesulfonamide derivative with a polyamide resin has been proposed.

Considering the prior art in detail, the method of adding ethylene copolymer and modified polytetraproloethylene to the polyamide resin can increase the melt strength and can be extruded, but it can be used as a pipe or tube. Flexibility is a problem. In addition, when caprolactam is added as a plasticizer, the melting point is low, so that a large amount of gas is generated during molding, and the surface must be processed poorly, and the caprolactam escapes into the atmosphere during processing depending on the processing conditions, thereby deteriorating flexibility. Let's do it.

In addition, drying after compounding is essential in resin production. Since caprolactam is highly volatile, it has to be dried for a long time by lowering the drying temperature. Thus, caprolactam is migrated to the product surface in the product Mandrell. Phenomenon makes repeated use difficult.

The present invention provides a polyamide resin composition that is useful as a material such as Mandrel used to make a pipe for bending because of its excellent flexibility and extrusion resistance and impact resistance and productivity to solve such conventional problems. I would like to.

To this end, the present invention provides a polyamide resin composition in which the dimerized fatty acid is added to the polyamide 6 resin and the dimerized fatty acid as the softener and maleic anhydride grafted as an impact agent.

The polyamide resin composition of the present invention for achieving the above object is 20 to 50 parts by weight of two-fiber grafted maleic hydride with respect to 100 parts by weight of polyamide resin and dimerized fatty acid (Dimerized Fatty Acid) 10 It is characterized by that it contains -40 parts by weight.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the composition of the present invention, the polyamide resin preferably used is polyamide 6 having a basic structure of the following general formula (1), and the relative viscosity of polyamide 6 is 3.0 to 3.5 (20 ° C, polyamide in 100 ml of 96% sulfuric acid). 6 resin 1g solution).

[Where n is an integer from 200 to 15,000]

When the viscosity of the polyamide 6 resin is less than 3.0, the extrusion temperature is poor due to the narrow molding temperature range when the product is processed by extrusion molding, and when it exceeds 3.5, the polyamide 6 resin is subjected to a solid phase polymerization process because of difficulty in manufacturing in melt polymerization. It is disadvantageous in terms of cost because it must be prepared and not only is not preferable, but also leads to an increase in the molding temperature does not advantageously act on extrusion workability.

The polyamide 6 resin includes 7.17 parts by weight of water, 0.004 parts by weight of bubble inhibitor, and tris- (2.4-dibutyl butylphenyl) -phosphite and N-N'-hexa, which are heat-resistant agents, based on 100 parts by weight of V-caprolactam. 0.09 parts by weight of Irganox B1171 (trade name, manufactured by Ciba Gaiji), a 1: 1 mixture of methylene bis (3.5-dibutyl butyl-4-hydroxy-hydrocinamide), was added to a reaction tube at 260 ° C. After the reaction, the pressure was raised to 15Kg / ㎠ and reacted for 1 hour, and then the pressure was gradually reduced while maintaining the pressure for about 30 minutes. It can be prepared by further proceeding to terminate the reaction while adding nitrogen.

The polyamide 6 resin obtained by the above method is preferably made into a chip form for the final resin composition according to the present invention and used after drying at 85 ° C. for 6 hours in a dehumidifying dryer.

In the present invention, in addition to these additives, the following amine-based and phenol-based antioxidants may be used as the heat-resistant agent required for the compounding process of the resin.

Amine-based heat-resistant agent that can be used in the present invention is 2,2,4-trimethyl-1,2-dihydro quinoline {2,2,4-Trimetyl-1,2-dihydro quinoline} or a polymer compound thereof, Phenyl-naphthylamine {Phenyl--naphthylamine}, Phenyl-naphthylamine}, Alpha-naphthylamine {-naphthylamine}, N`-di-secondary-butyl-para -Phenylenediamine {N, N`-Di-sec-butyl-p-phenylenediamine}, N, N`-Diphenyl-para-phenylenediamine {N, N`-Diphenyl-p-phenylenediamine}, N, N `-Di-beta-naphthyl-para-phenylenediamine {N, N`-Di--naphthyl-p-phenylenediamine}, 4,4`-tetramethyldiaminodiphenylmethane {4,4`-Tetramethyl diamino diphenyl methane}, aldol-naphthylamine, N, N`-bis (1-methyl-heptyl) -para-phenylenediamine {N, N`-bis-(1-methyl- heptyl) -p-phenylenediamine}, N, N`-di-secondary-butyl-para-phenylenediamine {N, N`-Di-sec-butyl-p-phenylenediamine}, N, N`-bis -Ethyl-3-methyl-phenyl) -wave -Phenylenediamine {N, N`-Bis- (1-ethyl-3-methyl-phenyl) -p-phenylenediamine}, para-iso-propoxyl diphenylamine}, N, N `-Di-beta-naphthyl-para-phenylenediamine {N, N`-Di--naphthyl-p-phenylenediamine}, 6-ethoxy-2, 2,4-trimethyl-1,2-dihydroquinoline {6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquino line}, N-phenyl-N`-isopropyl-para-phenylenediamine {N-Phenyl-N`-isopropyl-p-pheny lenediamine }, 4,4`-bis (4-alpha, alpha-dimethylbenzoyl) diphenylamine {4,4`-Bis- (4- -methylbenzoyl) diphenylamine}, 2,6-di-tertiary-butyl-alpha -Dimethylamino-para-cresol {2,6-Di-t-butyl--dimethylamino-p-cresol}, N-cyclohexyl-N`-phenyl-para-phenylenediamine {N-Cyclohexyl-N`-phenyl -p-phenylenediamine}, dioctyl-p-phenylenediamine, phenylhexyl-para-phenylenediamine {Phenyl hexyl-p-phenylenediamine}, phenyloctyl-para-phenylenediamine {Phenyloctyl- p-phenyl enediamine}, diheptyl -Para-phenylenediamine {Diheptyl- p-phenylenediamine}, oxalyl bis (benzylidene hydrazide) {Oxalyl bis (benzylidene hydrazide)}, 6- (4-hydroxy-3,5-di-tertiary- Butylanilino) -2,4-bis-octyl-thio-1,3,5-triazine {6- (4-hyrdoxy-3,5-di-t-butyl anilino) -2,4-bis-octyl -thio- 1,3,5-triazine}, 3- (N-salicyloyl) amino-1,2,4-triazole {3- (N-Salicyloyl) amino-1,2,4-triazole} , P, P`-dioctyl-diphenylamine}, Di-o-tolyl-guanidine salt of di-cathechol borate}, N-phenyl-N`-isopropyl-para-phenylenediamine {N-phenyl-N`-iso-propyl-p-phenylenediamine}, di-ortho-tolyl thiourea {Di-o-tolyl-thiourea}, thio Thiocar banilide, zinc diethyl dithiocarbamate, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, Zn salt of 2 -Mer captobenz imidaz ole}, 2-mercaptomethylbenzimidazole {Zn salt of 2-Mer capto methylbenzimidazole}, N-1,3-dimethylbutyl- N`-phenyl-para-phenylenediamine {N-1,3-Di methylbutyl-N`-phenyl-p-phenylene diamine}, diethyl hydroxylamine {1,3-dibutylthiourea { 1,3-Dibutylthiourea}, 1,3-diethylthiourea {1,3-Diethylthiourea}, phenothiazine {Phenothiazine}, N- (2-ethyl-phenyl-)-N`- (2-ethoxy- 5-tert-butyl phenol) oxalic aciddiamine {N- (2-Ethyl-phenyl) -N`- (2-ethoxy-5-t-butyl phenol) oxalic acid diamide}, ortho-toryl-biguanide { O-Tolyl-biguanide}, N, N`-diphenylethylenediamine, N, N`-diphenylethylenediamine, N, N`-Diphenyl propylenediamine, N, N`-di -Ortho-toryl-ethylenediamine {N, N`-Di-o-tolyl-ethyl enediamine}, N-lauryl-para-aminophenol {N-Lauryl-p-aminophenol}, N-stearyl-para-amino Phenolic {N- Stearyl-p-aminophenol}, Ethylene thio urea}, P, P-dimethoxy diphenylamine {P, P-dimethoxy diphenylamine}, N-octyl-N`-phenyl-para-phenylenediamine {N -Octyl-N`-phenyl-p-phenylenediamine}, N, N`-di- (1,4-dimethyl-pentyl) -para-phenylenediamine {N, N`-Di- (1,4-dimethyl- pentyl) -p-phenylenediamine} may be used.

And as a phenolic heat resistant agent, 6- tert- butyl- 2, 3- dimethyl- 4- (dimethylaminomethyl)-phenol, 6- tert- octyl- 2, 3- dimethyl- 4- (dimethylamino methyl) -Phenol, 6-tertiary-butyl-4- (dimethylaminomethyl) -5,6,7,8-tetrahydro-1-naphthol, 5-tertiary-butyl-2,3-dimethyl-4-hydroxy Benzylphosphonate, N, N`-nucleated methylenebis (3,5-di-tertiary-butyl-4-hydroxyhydrocinamide) (N, N`-hexametylenebis (3,5-di-t-butyl- 4-hydroxyhyd

rocinnamamide), N, N`-trimethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinamide) (N, N`-trimetylenebis (3,5-di-t-butyl-4- hydroxyhydrocinnamamide), tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxy-phenyl) propionate] methane, tris [beta- (3,5-di-tertiary-4- Hydroxy-phenyl) propionyl-oxyethyl] isocyanurate, etc. Here, the heat resistance of the amine-based and phenolic heat-resistant agent is excellent in the amine-based, but phenol-based mainly because of the excellent phenol-based color. More preferably.

Amine-based and / or phenolic heat-resistant agent is preferably used about 0.1-1.0 parts by weight with respect to 100 parts by weight of polyamide resin, but less than 0.1 parts by weight to effectively prevent the rise of carboxyl end groups during the molding process It is difficult, and when it exceeds 1.0 weight part, there exists a concern about the fall of the physical property by excessive addition of a heat resistant agent, and the effect of improving heat resistance with respect to excessive addition amount is also insignificant.

As the impact resistant agent, 20 to 50 parts by weight of an epi rubber grafted with maleic anhydride is used based on 100 parts by weight of a polyamide resin. If the maleic anhydride is grafted with maleic anhydride, there is no problem, but it is better to use an male rubber with 0.3 to 0.9% of maleic anhydride, more preferably 0.4%.

If maleic anhydride has a graft ratio of less than 0.3%, compatibility with nylon may not be sufficient, and die swelling may occur during extrusion and peeling may occur in the product.

In addition, if it exceeds 0.9%, it takes a lot of pressure during extrusion, and may cause a deterioration of flexibility, so it is necessary to select an appropriate ratio. If the content of this rubber to 100 parts by weight of polyamide resin is less than 20 parts by weight, the impact resistance and flexibility are insufficient, which is not suitable for the use of the present invention. Difficulties cause product shaping to be difficult.

Dimerized Fatty Acid is used as a softening agent. The dimerized fatty acid is an unsaturated fatty acid having 18 carbons, which is bound in various ways. The main form is two molecular chains having 9 to 18 carbon atoms bonded to an unsaturated fatty acid having 18 carbon atoms.

The dimerized fatty acid has 18 to 56 carbon atoms in the molecular chain and 1 to 4 carboxyl groups.

An example of the structure of the dimerized fatty acids (Dimerized Fatty Acids) is shown in the following structural formula (II).

[Formula II]

[Wherein R1 and R2 are molecular chains having 9 to 18 affinity, X is linear, aliphatic or aromatic ring structure]

Representative structures of components in which X in the above formula (II) has a linear structure are as follows.

The representative structure of the component whose X of the said Formula (II) becomes an aliphatic ring structure is as follows.

Representative structures of the components having a structure in which X in the above formula (II) has a bicyclic structure are as follows.

Representative structures of the component in which X in the formula (II) is an aromatic ring structure are as follows.

The softener used in the present invention is easy to add during compounding, and unlike other softeners, there is no fear of volatilization during processing to lower its performance. In this invention, 10-30 weight part of said softening agents are added with respect to 100 weight part of polyamide resins. If the amount is less than 10 parts by weight, the effect is insignificant, and if it is more than 40 parts by weight, the effect is not only small, but also the cost is not economical.

In addition, the total content of the impact-resistant agent and the softening agent described above with respect to 100 parts by weight of the polyamide resin is preferably 30 to 60 parts by weight. If the content is less than 30 parts by weight, such properties as flexibility is not expressed, and if it exceeds 60 parts by weight, the melt index is large, causing problems in extrusion as well as problems in heat resistance depending on the application.

The polyamide resin composition obtained in the present invention can be applied to the use of shoe soles, such as mandrel, which is an extruded part requiring flexible properties, and other parts requiring flexibility and impact resistance.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following examples.

Example 1

In the first inlet of the three-screw inlet, 100 parts by weight of polyamide 6 resin having a relative viscosity of 3.2 and 0.5 parts by weight of heat-resistant agent 6-tertiary-butyl-2.3-dimethyl-4- (dimethyl amino methyl) -phenol , 0.01 part by weight of a common release agent and 0.01 part by weight of a conventional coupling agent were blended, and 50 parts by weight of an impact agent of an epi rubber, in which 0.4% of maleic hydride was grafted, was introduced into the second inlet of the biaxial compressor. Into the third inlet of the twin-screw compressor, two unsaturated chains of 18 carbon atoms are bonded to 18 unsaturated fatty acids, and 10 parts by weight of a softener of dimerized fatty acid (X = linear) having 36 carbon atoms and two carboxyl groups in the molecular chain is added. After melting and kneading at 250 ° C. to prepare a polyamide resin composition, it was discharged in a chip state. The prepared chip was dried in a hot air dryer at 85 ° C. for 5 hours, and then put into a screw injection machine at 255 ° C. to prepare a specimen for measuring physical properties.

The results of evaluating the physical properties and formability of the prepared specimens are shown in Table 2.

Examples 2 to 4 and Comparative Examples 1 to 6

A polyamide resin composition and a specimen thereof were prepared in the same manner as in Example 1 except that the contents of the impact resistant agent and the softening agent were changed as shown in Table 1.

The results of evaluating the physical properties and formability of the prepared specimens are shown in Table 2.

In the present invention, various physical properties of the specimen were measured by the following method.

ㅇ Tensile strength : According to ASTM D683, 1/8 inch specimens were prepared and measured.

Flexibility : Flexural modulus was measured according to ASTM D-790.

ㅇ Melt index : The melt index was evaluated according to ASTM D-1238 at 240 ℃.

ㅇ Impact strength : Izod Notched impact strength was measured at room temperature by making 1/4 inch specimen according to ASTM D256.

Manufacture conditions division Polyamide 6 Resin (parts by weight) Impact Resistant (parts by weight) Softener (parts by weight) Example 1 100 50.0 10.0 Example 2 100 20.0 30.0 Example 3 100 20.0 20.0 Example 4 100 40.0 15.0 Comparative Example 1 100 5.0 30.0 Comparative Example 2 100 40.0 0.0 Comparative Example 3 100 20.0 5.0 Comparative Example 4 100 0 5.0 Comparative Example 5 100 0 40.0

Property evaluation result          Item division Tensile Strength (Kg / ㎠) Flexural modulus (Kg / ㎠) Melt Index (g / 10min) Formability Impact Strength (Kg.cm/cm) Example 1 364 4504 8 Good 98 Example 2 352 4105 11 Good 105 Example 3 467 4882 13 Good 92 Singha Example 4 417 4477 10 Good 95 Comparative Example 1 687 7168 16 Bad 47 Comparative Example 2 618 7685 12 Good 85 Comparative Example 3 591 8105 13 Good 69 Comparative Example 4 753 12465 14 Bad 15 Comparative Example 5 425 6153 18 Bad 43

The present invention is excellent in flexibility and can be extruded, and excellent in impact resistance and productivity, it is useful as a material for mandelels required to make a pipe or tube for bending.

Claims (8)

Highly flexible polyamide, characterized in that 20 to 50 parts by weight of an epi rubber, which is grafted with maleic hydride and 10 to 40 parts by weight of dimerized fatty acid, is contained per 100 parts by weight of polyamide resin. Resin composition. The polyamide resin composition having excellent flexibility according to claim 1, wherein 0.1 to 1.0 parts by weight of an amine or phenolic heat resistant agent is included with respect to 100 parts by weight of the polyamide resin. The polyamide resin composition having excellent flexibility according to claim 1, wherein the polyamide resin is a polyamide 6 resin having a relative viscosity of 3.0 to 3.5. The polyamide resin composition having excellent flexibility according to claim 1, wherein maleic anhydride is grafted at 0.3% to 0.9% on the epi rubber. The polyamide resin composition having excellent flexibility according to claim 1, wherein the total content of the epilebber and dimerized fatty acid grafted with maleic hydride is 30 to 60 parts by weight based on 100 parts by weight of the polyamide resin. The polyamide resin composition having excellent flexibility according to claim 1, wherein the dimerized fatty acid has 18 to 56 carbon atoms in the molecular chain and 1 to 4 carboxyl groups. The polyamide resin composition having excellent flexibility according to claim 1, wherein the dimerized fatty acid has a structure in which two molecular chains having 9 to 18 carbon atoms are bonded to an unsaturated fatty acid having 18 carbon atoms. delete