KR20120078446A - Eco-friendly gasket resin composition of improved wear resistance, gasket for sealing door of drum type washing machine using the resin composition, and drum type washing machine employing the gasket - Google Patents

Abstract

PURPOSE: An environment-friendly resin composition is provided to have low hardness, and to have improved elasticity, tensile strength, thermal resistance, etc, and not to generate side product and bed smell due to vulcanization. CONSTITUTION: An environment-friendly resin composition comprises: 100.0 parts by weight of thermoplastic elastomer comprising a styrene block and a diene block; 5-50 parts by weight of ethylene propylene diene vulcanized rubber; 5-100.0 parts by weight of polyphenyleneether-based resin; 1-50 parts by weight of polyolefin resin; 30-150 parts by weight of oil components; 30-150 parts by weight of an inorganic additives; 0.1-5.0 parts by weight of slip agent; and 0.01-10.00 parts by weight of a functional additives. The ethylene propylene diene vulcanized rubber is manufactured by dynamic crosslinking ethylene-propylene-diene rubber mixture, and polypropylene.

Description

Eco-friendly gasket resin composition of improved wear resistance, gasket for sealing door of drum type washing machine using the resin composition , and drum type washing machine employing the gasket}

The present invention serves to seal the front door and the drum of the drum type washing machine to prevent leakage of water during washing, absorbing the vibration of the washing machine drum is transmitted to the main body of the drum type washing machine door sealing gasket to reduce the shaking of the washing machine The present invention relates to a resin composition optimized for production, a gasket made of the resin composition, and a drum type washing machine having the gasket.

Nitrile butadiene rubber (NBR) or general synthetic rubber products are mainly used as a material for the drum washing machine gasket. However, when NBR is used as a material, it is resistant to sunlight in the air due to the inherent properties of the material. In case of prolonged exposure, the product is aging by ozone (O ₃ ) in the air, which causes cracks in the product and easily tears or leaks.

In particular, when using a rubber raw material that is weak to ozone, such an aging problem may cause a serious effect, for example, due to aging due to sunlight, the gasket may be torn and water leaks due to water leakage may occur when the washing machine starts, When used indoors, problems such as water accumulation on the floor occur.

In addition, when general synthetic rubber is used, it is difficult to manufacture a product having high tensile strength because the hardness of the product is very low.In order to increase the tensile strength of the product, the amount of filler added and the rubber content are increased. There is a method to improve the tensile strength, but this method is limited to rubber products with hardness greater than 50 (Shore A), and at lower hardness, the tensile strength does not improve even if the content of raw rubber is increased. There is a disadvantage that increases.

In addition, when using a product of high hardness in order to increase the tensile strength, the vibration generated from the drum and the motor of the washing machine is not absorbed and is transmitted to the washing machine main body, which causes a problem that the noise and vibration are severe when the washing machine is operated.

As a rubber material for gaskets, ethylene propylene diene monomer (EPDM) rubber, an elastomer terpolymer containing oil in the raw material itself, is also used. EPDM rubber has high tensile strength even at low hardness. Due to low productivity, the manufacturing cost is high, and unreacted sulfur by-products may remain due to the cross-linking process through vulcanization, so that the odor peculiar to EPDM rubber is caused by heat generated during laundry drying, which is not environmentally friendly.

Korean Patent Publication No. 10-0868405 discloses a thermoplastic elastomer comprising an propylene-ethylene copolymer and a polyethylene homopolymer, a thermoplastic elastomer including an styrene block and a diene block, an oil component, and an inorganic material. A resin composition for washing machine gaskets comprising additives and functional additives is disclosed.

By the way, the gasket made of the composition has a problem that the rubber gasket is thermally deformed by high heat (boiling method) when washing the drum type washing machine.

In addition, as a gasket material of a drum type washing machine, the continuous rotation of the drum washing machine and the continuous friction with the laundry may cause leakage and tearing due to abrasion. It has a direct impact.

The present invention is to solve the problems of the prior art, the first problem to be solved by the present invention is to seal the drum type washing machine door with improved physical properties such as elasticity, tensile strength, heat resistance and environmentally friendly properties while maintaining low hardness It is to provide a resin composition for producing a gasket.

In addition, the second problem to be solved by the present invention is to provide a drum type washing machine door sealing gasket having a high productivity because it is made of the resin composition, can be easily produced by an injection molding method.

In addition, a third problem to be solved by the present invention is to provide a drum type washing machine having the drum type washing machine door sealing gasket to improve wear resistance and increase product stability and lifespan.

In order to achieve the first object, the present invention 100 parts by weight of a thermoplastic elastomer comprising a styrene block and a diene block; 5-50 parts by weight of ethylene propylene diene vulcanized rubber; 5 to 100 parts by weight of polyphenylene ether resin; 1 to 50 parts by weight of polyolefin resin; 30 to 150 parts by weight of an oil component; 30 to 150 parts by weight of an inorganic additive; 0.1 to 5.0 parts by weight of slip agent; It provides a resin composition for eco-friendly gaskets, including; and a functional additive 0.01 ~ 10.00 parts by weight.

In order to achieve the second object, the present invention provides a drum type washing machine door sealing gasket manufactured by injection molding the resin composition for the gasket.

In order to achieve the third object, the present invention provides a drum type washing machine having the door sealing gasket.

Since the resin composition for gasket according to the present invention is a thermoplastic elastomer and is a non-crosslinked resin composition, moldability and productivity are improved, and by-product generation and odor due to the vulcanization crosslinking process are not induced, thereby having environmentally friendly characteristics.

In addition, the washing machine door sealing gasket manufactured by the composition for the gasket has the advantage that the injection molding is possible, the manufacturing cost is lowered and the wear resistance is improved.

In addition, the drum washing machine equipped with the gasket has the effect of improving product stability and life.

Hereinafter, the present invention will be described in detail.

The resin composition for the gasket according to the present invention is a thermoplastic elastomer comprising a styrene block and a diene block, an ethylene-propylene-diene vulcanized rubber, an elastomer terpolymer, a polyphenyleneether (PPE) -based resin, a polyolefin resin, an oil component, Inorganic additives, slip agents and functional additives.

Each of these components will be described in more detail as follows.

Thermoplastic elastomer

Thermoplastic elastomers are used to control the tensile strength, elongation and elasticity of the gasket and to improve wear resistance.

The thermoplastic elastomer includes binary or terpolymers containing styrene blocks and diene blocks, for example styrene-butadiene-styrene (SBS) binary copolymers, styrene-ethylene-butadiene-styrene styrene-ethylene-butadiene-styrene (SEBS) terpolymer, styrene-ethylene-ethylene-propylene-styrene (SEEPS) terpolymer and styrene-ethylene-butadiene endowed with functional groups Styrene (functionalized styrene-ethylene-butadiene-styrene, f-SEBS) terpolymer and styrene-ethylene-ethylene-propylene-styrene (f-SEEPS) terpolymer Can be.

The copolymers of SBS, SEBS, SEEPS and the like not only exhibit elasticity over natural rubber, but also exhibit low permanent compressive distortion (permanent compression reduction) characteristics, and have low temperature dependency and excellent heat aging and weather resistance.

In addition, the copolymers are suitable for products that must maintain low hardness, and have excellent role and processability as compatibilizers in resin blends.

SEBS or SEEPS of the copolymer is advantageous in terms of physical properties, and the f-SEBS or f-SEEPS may be blended into the thermoplastic elastomer for further improvement of compatibility.

EPDM (Ethylene-propylene- Dien Monomer , ethylene propylene diene monomer ) Vulcanized Rubber

EPDM vulcanized rubber is preferably made of an olefinic thermoplastic elastomer (TPV) of polypropylene (PP) and EPDM rubber mixture by dynamic vulcanization.

The EPDM vulcanized rubber may be used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the thermoplastic elastomer, and when the content is less than 5 parts by weight, the tensile strength improvement, the permanent compression distortion reduction, and the heat resistance improvement effect are insignificant, and 50 weight. When the amount is exceeded, the compatibility with binary or terpolymers containing styrene blocks and diene blocks is lowered, resulting in a problem of deterioration of physical properties.

The EPDM vulcanized rubber is suitable for having a Shore hardness of 40 to 90 A as a product containing minerals and oils. Examples of such products include Santoprene, Lotmer, Innoprene, and the like. For example.

Polyphenylene ether system  Suzy

Examples of the polyphenylene ether resin include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2,6-di Propyl-1,4-phenylene) ether, poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly ( Copolymer of 2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenyl Copolymers of ylene) ether and poly (2,3,6-triethyl-1,4-phenylene) ether may be used, with poly (2,6-dimethyl-1,4-phenylene) ether more preferred. Do.

The degree of polymerization of the polyphenylene ether resin is not particularly limited, but considering the thermal stability and workability of the resin composition for the gasket, the intrinsic viscosity measured in a chloroform solvent at 25 ° C. is preferably 0.2 to 0.8.

The polyphenylene ether resin may be used in an amount of 5 to 100 parts by weight based on 100 parts by weight of the thermoplastic elastomer. When the content is less than 5 parts by weight, the effect of improving heat resistance is small. The hardness and modulus become too high, resulting in a problem that the damping characteristics are weakened.

Polyolefin  Suzy

According to one embodiment of the present invention, the polyolefin resin may be polyethylene, polypropylene or ethylene-propylene copolymer, crystalline propylene homopolymer (homo-polypropylene, HPP) is more preferred.

Melt index (Melt Index, MI) of the HPP is preferably 5 ~ 40g / 10 minutes, more preferably 10 ~ 30g / 10 minutes under the conditions of 230 ℃, 2.16kg load.

The polyolefin resin may be used in an amount of 1 to 50 parts by weight based on 100 parts by weight of the thermoplastic elastomer, and when less than 1 part by weight, the manufactured gasket may have a low hardness, thereby causing deformation by compression, and more than 50 parts by weight. If the hardness is too high, the permanent compression reduction rate increases and the vibration damping property tends to deteriorate.

High permanent compression rates can cause permanent deformation by repeated opening and closing of the washing machine door.

Oil ingredients

The oil component is used for the purpose of lowering the aforementioned thermoplastic elastomer, that is, as a softener.

Low-hardened materials are easy to mold, have excellent dust and water resistance, and exhibit excellent workability during molding by reducing heat generated during kneading.

As the oil component, various oils such as naphthenic oil, paraffinic oil or olefin oil, mineral oil, vegetable oil or synthetic oil may be used.

The oil components may be used alone or may be used by mixing two or more oil components. However, when the gasket forming drum washing machine is dissolved, the oil components may lose their properties as a resin composition for the gasket. It is preferable that the average molecular weight exceeds 600 g / mol.

The oil component may be used in an amount of 30 to 150 parts by weight based on 100 parts by weight of the thermoplastic elastomer, and when it exceeds 150 parts by weight, the oil bleeds out (Bleed-out) becomes severe and the product becomes sticky and product processability deteriorates. If the phenomenon occurs, less than 30 parts by weight, the hardness of the product is too high, there is a problem that the dust and waterproof properties are sharply lowered.

Inorganic additives

Inorganic additives are used to improve physical performance, such as permanent compression deformation of gaskets for drum washing machines.

As the inorganic additive, calcium carbonate, talc, magnesium hydroxide, clay, barium sulfate, silica, titanium oxide, carbon black, and the like may be used, and may be used alone or in combination of two or more. Calcium and talc are more preferred in terms of physical properties.

The inorganic additive may perform a function of controlling the content of the polyolefin-based resin and the thermoplastic elastomer by controlling the content of the inorganic additive, in addition to the function for improving the physical properties.

The inorganic additive may be used in an amount of 30 to 150 parts by weight based on 100 parts by weight of the thermoplastic elastomer, and if the content is less than 30 parts by weight, the permanent compression deformation is severe and may cause problems when using the product for a long time. The mechanical strength of the product may be too low and may weaken the suitable ductility, ie the rubbery properties required for the gaskets for drum washing machines.

Slip

Slip agent is used to improve the releasability with the mold during injection of the gasket for the washing machine to improve the productivity and improve the wear resistance to improve the part performance.

The slip agent includes a slow-release slip agent such as polydimethyl siloxane (PDMS), oleamide, erucamide, oleyl palmitamide, stearly erucamide ) And fast-acting slip agents such as ethylene bis oleamide, and the like, and may be used alone or in combination of two or more.

Particularly, the use of the slow-release slip agent and the fast-release slip agent is preferable in terms of improving wear resistance and moldability, and the slow-release slip agent is more preferably ultra high molecular weight (UHMW) PDMS.

The slip agent component may be used in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the thermoplastic elastomer, and when the content of the slow release slip agent exceeds 5.0 parts by weight, the compatibility decreases and delamination between the gasket material and the slip agent occurs. As a result, a phenomenon in which the performance of the part occurs is deteriorated, and when the content of the fast-acting slip agent exceeds 5.0 parts by weight, the phenomenon of product processability, productivity, and part performance may be deteriorated due to gas generation during injection.

In addition, when the slow-release slip agent or the fast-acting slip agent content is less than 0.1 parts by weight, the mold release property and wear resistance of the product is lowered and the performance of the parts is lowered.

Functional additives

As the functional additive, neutralizing agents, stabilizers, antistatic agents, antioxidants, colorants, UV stabilizers, antibacterial agents or color master batches can be used, and can be used alone or in combination of two or more.

The functional additive may be used in an amount of 0.01 to 10.00 parts by weight based on 100 parts by weight of the thermoplastic elastomer.

As a method of preparing the composition of the present invention, a conventional method of mixing and preparing a conventional thermoplastic polymer composition may be employed, and for example, a single screw and twin screw extruder, a super-mixer, a Banbury-mixer ), Various kneaders, rolls and the like can be used.

Since the resin composition for a drum washing machine gasket according to the present invention can be easily molded by an injection molding method, the gasket for a drum washing machine made of the resin composition is manufactured by an injection molding method and thus has excellent production efficiency.

The gasket may be applied to a drum washing machine, which has been produced in recent years, and may perform an excellent function. The gasket may be disposed between the door and the drum of the washing machine to function as a sealing member.

Hereinafter, the present invention will be described in more detail with reference to the following examples, comparative examples and test examples.

It is to be understood, however, that the invention is not to be construed as limited to the embodiments set forth herein, but is capable of modifications and equivalents within the spirit and scope of the invention. Will be apparent to those skilled in the art to which the present invention pertains.

<Examples 1-4> and <Comparative Example>

The compositions of Examples and Comparative Examples of Table 1 were mixed in a supermixer, and then extruded at a temperature of 230 ° C. to 290 ° C. using a twin screw extruder having an L / D of 30 or more, and then granulated in pellet form.

Composition ratio of the Example and Comparative Example composition (unit: weight%) Composition Example Comparative example One 2 3 4 SEBS ^{Note 1)} 32 33 - - 32 SEEPS ^{Note 2)} - - 32 33 - EPDM Vulcanized Rubber ^{Note 3 )} 5 5 5 5 - PPE ^{Note 4)} 11 11 11 11 - PP ^{Note 5)} 6 5 6 5 6 Oil ^{Note 6)} 31 31 31 31 48.5 CaCO ₃ ^{Note 7)} 13 13 13 13 13 Slow Release Slip Agents ^{Note 8 )} One 1.4 One 1.4 - Fast-acting slip agent ^{Note 9 )} 0.5 0.1 0.5 0.1 - Functional additives ^{Note 10 )} 0.5 0.5 0.5 0.5 0.5

Note 1) Thermoplastic elastomer: G1651H, manufactured by Kraton, USA

Note 2) Thermoplastic elastomer: Septon 4055, manufactured by Kuraray, Japan

Note 3) EPDM vulcanized rubber: Innoprene 1550 N / B (hardness 56A), manufactured by Kumho Polychem, Korea

Note 4) Polyphenylene ether resin: S201A, manufactured by Asahi Kasei, Japan

Note 5) Polyolefin resin: HJ700 grade (homo-polypropylene), Samsung Total manufacture, Korea

Note 6) Oil component: KL-900B (Process oil), Seojin Chemical Manufacturing, Korea

Note 7) Inorganic additives: calcium carbonate (average particle diameter 2㎛), manufactured by Omya, Korea

Note 8) Slow Release Slipper: MB50-001 (concentrate 50% of UHMW-polydimethyl siloxane in homo-polypropylene resin), manufactured by Multibase, France

Note 9) Fast-acting slip agent: Amorslip-E (erucamide), manufactured by Akzo-Nobel, The Netherlands

Note 10) Functional additives: phenolic primary antioxidant, phosphorus or amine secondary antioxidant, ultraviolet light stabilizer (Siva Specialty Chemicals, Switzerland)

 <Test Example>

Using a commercially available gasket for washing machines (EPDM resin, manufactured by S Company) as a control, the pellets of Examples 1 to 4 and Comparative Examples were injection-molded, and a 150 × 150 mm sheet having a thickness of 2 mm was used at a 200 ° C. press. After fabrication, the specimen was processed into specimens for physical property evaluation.

The test method used was as follows, and the results are shown in Table 2.

Tensile strength, elongation: ASTAM D412

Hardness: ASTM D2240, measured after 5 seconds

Tension set: ASTM D412

Tension creep: ASTM D2991

-Tabber abrasion test: ASTM D4060

Physical property measurement result Composition unit Example Comparative example Control group One 2 3 4 The tensile strength MD ^{Note 1)} kg _f / cm ² 75 73 77 76 45 103 TD ^{Note 2)} kg _f / cm ² 76 72 78 76 50 105 Elongation MD % 700 720 680 700 600 800 TD % 720 720 670 710 620 800 Hardness Shore a 42 41 42 42 42 41 Kidney Permanent Grain Ratio % 6 7 6 7 20 5 Creep test % 5 5 5 5 15 5 Abrasion Resistance (12,000) g loss 0.12 0.35 0.14 0.36 3.7 2.4 Deformation of gasket after drum washing machine set experiment transform
none transform
none transform
none transform
none transform
none transform
none

Note 1) MD: Machine Direction

Note 2) TD: Transverse Direction

According to the Table 2, the tensile strength of the Example is lower than the control group, but shows better characteristics than the comparative example, which is analyzed to improve the tensile strength by the addition of EPDM vulcanized rubber to the composition of the Example.

In addition, the reason why the physical properties between the MD and TD does not appear in the example and the difference in the comparative example is also considered to be the reason that PPE, which is an amorphous material, is added only to the example and not added to the comparative example.

In Examples 1 to 4, PPE and EPDM vulcanized rubber were added, and thus the heat resistance was excellent, and the wear resistance was improved due to the addition of the slip agent, so that the gasket was not deformed, leaked, or torn after the drum washing machine set experiment.

In addition, the embodiments were easy to injection molding, the cross-linking process by the vulcanization operation was omitted, there was no odor due to vulcanization, and showed an environmentally friendly property that can maintain the physical properties even if a certain amount of recycling.

As described above, the resin composition for the gasket according to the present invention is a thermoplastic elastomer, which is a non-crosslinked resin composition, which improves moldability and productivity, and does not cause by-product generation and odor due to the vulcanization crosslinking process, thereby exhibiting environmentally friendly characteristics. Washing machine door sealing gasket manufactured by the composition for the gasket can be injection molded to reduce the manufacturing cost and improve the wear resistance, drum washing machine equipped with the gasket has the effect of improving product stability and life.

Claims (12)

100 parts by weight of a thermoplastic elastomer including a styrene block and a diene block;
5-50 parts by weight of ethylene propylene diene vulcanized rubber;
5 to 100 parts by weight of polyphenylene ether resin;
1 to 50 parts by weight of polyolefin resin;
30 to 150 parts by weight of an oil component;
30 to 150 parts by weight of an inorganic additive;
0.1 to 5.0 parts by weight of slip agent; And
A resin composition for an eco-friendly gasket comprising a functional additive 0.01 ~ 10.00 parts by weight; The method according to claim 1,
The thermoplastic elastomer including the styrene block and the diene block may be a styrene-butadiene-styrene binary copolymer, a styrene-ethylene-butadiene-styrene terpolymer, a styrene-ethylene-ethylene-propylene-styrene terpolymer, or a styrene endowed with a functional group. -Ethylene-butadiene-styrene terpolymer and at least one selected from the group consisting of functional group styrene-ethylene-ethylene-propylene-styrene terpolymer, wear resistance improved environmentally friendly gasket resin composition. The method according to claim 1,
Wherein the ethylene propylene diene vulcanized rubber is characterized in that the polypropylene and ethylene-propylene-diene rubber mixture, characterized in that it is manufactured by dynamic crosslinking, wear resistance improved environmentally friendly gasket resin composition. The method according to claim 1,
The polyphenylene ether resin may be poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-di Propyl-1,4-phenylene) ether, poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly ( Copolymers of 2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether and poly (2,6-dimethyl-1,4-phenyl A resin composition for eco-friendly gaskets having improved wear resistance, characterized in that at least one selected from the group consisting of copolymers of lene) ether and poly (2,3,6-triethyl-1,4-phenylene) ether. The method according to claim 1,
The polyolefin resin is at least one selected from the group consisting of polyethylene, polypropylene and ethylene-propylene copolymers, resin composition for environmentally friendly gaskets with improved wear resistance. The method according to claim 1,
The oil component is at least one selected from the group consisting of naphthenic oil, paraffinic oil and olefinic oil, eco-friendly gasket resin composition for improved wear resistance. The method of claim 6,
Resin composition for an eco-friendly gasket, characterized in that the average molecular weight of the oil component exceeds 600g / mol. The method according to claim 1,
The inorganic additive is at least any one selected from the group consisting of calcium carbonate, talc, magnesium hydroxide, clay, barium sulfate, silica, titanium oxide and carbon black, eco-friendly gasket resin composition. The method according to claim 1,
The slip agent is at least one selected from the group consisting of a sustained-release slip agent of polydimethyl siloxane and a fast-acting slip agent of oleamide, erucamide, oleyl palmitamide, stearic erucamide and ethylenebisoleamide. Resin composition for eco-friendly gaskets to improve wear resistance. The method according to claim 1,
The functional additive is at least one selected from the group consisting of neutralizers, stabilizers, antistatic agents, antioxidants, colorants, UV stabilizers, antibacterial agents and color masterbatch, resin composition for environmentally friendly gaskets with improved wear resistance. A drum-type washing machine door sealing gasket manufactured by injection molding the resin composition according to any one of claims 1 to 10. A drum type washing machine comprising the drum type washing machine gasket for sealing the door of claim 11.