JP7025478B2 - Composition for wheel balance weights with excellent extrusion moldability and bending resistance - Google Patents

Description

The present invention relates to a wheel balance weight composition and a balancing weight containing a styrene resin, a base resin containing an ion-crosslinked elastic body, stainless steel (SUS) powder and a filler.

In general, when a tire wheel of an automobile has an unbalanced portion, vibration is generated by centrifugal force due to rotation, which leads to noise generation, tire uneven wear, handle shaking, and the like. Since the centrifugal force as described above is proportional to the rotation speed, the wheel balance must be accurate, especially when traveling at high speeds.

Such wheel balance is divided into static balance and dynamic balance due to its nature, but if the static balance is not achieved, the wheel vibrates up and down, and if the dynamic balance is not achieved, it vibrates in the left-right direction. Occurs. To correct the imbalance of a car wheel, apply a moderately heavy wheel balance weight to any edge on the opposite side of the wheel or rim where the weight imbalance occurs to reduce centrifugal force in the opposite direction. It needs to be generated and balanced.

Conventionally, as a wheel balance weight for adjusting such a wheel balance, a method of attaching a weight made of 5 g of lead to a tire or a rim with a tape-type adhesive has been known, but the environment using lead has been known. In addition to problems such as contamination, rust generation due to salt water when left for a long period of time, and a decrease in precision when using 5g units due to lack of flexibility, the adhesiveness to the wheel curved surface is reduced due to the tape type adhesive, and the interface is peeled off during long-term use. In addition, there are problems such as the occurrence of floating, and since it is difficult to apply an automatic process to such a conventional wheel balance weight, there is also the occurrence of an error due to human manual work.

Further, there has been an attempt to use a thermosetting and thermoplastic composite instead of a metal such as lead as the wheel balance weight, but there is a problem that the extrusion flowability and the bending strength are lowered.

Korea Public Patent Publication No. 10-2008-0013337

It is an object of the present invention to provide a balancing weight composition having a new composition excellent in various physical properties such as extrusion property and bending resistance while solving problems such as environmental pollution by not using lead.

Another object of the present invention is to provide a molded product produced by extrusion molding a balancing weight composition having a new composition.

Another object of the present invention is to provide a balancing weight produced by extrusion-molding a balancing weight composition having a new composition.

The object of the present invention is not limited to the object mentioned above. The object of the present invention will be clarified from the following description and will be realized by the means described in the claims and combinations thereof.

The composition for wheel balance weights according to an embodiment of the present invention contains a base resin containing a styrene resin and an ion-crosslinked elastic body, a stainless steel (SUS) powder, and a filler.

The base resin may contain 700 to 1,000 parts by weight of the stainless steel (SUS) powder and 3 to 10 parts by weight of the filler based on 100 parts by weight of the base resin.

The base resin can contain 80 to 90% by weight of a styrene resin and 10 to 20% by weight of an ion-crosslinked elastic body.

The styrene-based resin can include an elastic segment and a styrene block copolymerized at one end or both ends of the elastic segment.

The elastic segment can be polymerized from those selected from the group consisting of ethylene, propylene, butylene, butadiene, isoprene and combinations thereof.

The ion-crosslinked elastic body can be a copolymer of EPDM (Ethylene polypropylene dieene monomer) and a carboxylic acid monomer having 3 to 10 carbon atoms.

The ion-crosslinked elastic body can contain 98% by weight to 98.55% by weight of EPDM and 1.45% by weight to 2.00% by weight of the carboxylic acid monomer.

The filler may be selected from the group consisting of colloidal calcium carbonate, hard calcium carbonate and combinations thereof.

The filler may be surface-treated with a fatty acid or a metal salt thereof.

The fatty acid is a group consisting of saturated fatty acids including caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid and araquinic acid; unsaturated fatty acids containing oleic acid, elladic acid, linolenic acid and lysynolic acid; and combinations thereof. Can be chosen from.

The metal salt may be selected from the group consisting of an alkali metal salt of a fatty acid, an alkali metal salt of a resin acid, and a combination thereof.

It may be a high-density molded product obtained by extruding the wheel balance weight composition.

It may be a balancing weight obtained by extruding the wheel balance weight composition.

The balance weight may be applied to an automobile wheel.

The wheel balance weight composition according to the present invention does not cause environmental pollution due to heavy metals and can suppress the generation of rust.

Further, the composition for a wheel balance weight according to the present invention can have excellent adhesion to a curved surface of a wheel, excellent extrusion and bending resistance while having a high specific gravity equivalent to that of a heavy metal.

Further, the wheel balance weight composition according to the present invention can suppress the occurrence of interfacial peeling and floating.

Further, since the wheel balance weight composition according to the present invention can be applied to a roll type automatic cutting process, a precision attachment process in units of 1 g is possible, and the possibility of error generation due to a manual process can be reduced. can.

Further, the wheel balance weight composition according to the present invention can be applied equally regardless of the type of wheel and the vehicle using the wheel.

The effects of the present invention are not limited to the effects mentioned above. The effects of the present invention should be understood to include all effects that can be inferred from the following description.

It is a photograph of a molded product conventionally manufactured containing a composition for balance weight. It is a photograph of a balancing weight molded product produced by extrusion-molding the composition for balance weight produced in the present invention. It is a figure which shows the bending resistance test result with respect to the extrude of the composition by Examples 1 and 2 and Comparative Examples 1 and 2.

The above objectives, other objectives, features and advantages of the present invention will be readily understood from the following preferred embodiments in connection with the accompanying drawings. However, the present invention is not limited to the examples described herein, and may be embodied in other embodiments. Rather, the examples presented herein are provided so that the disclosed content can be thorough and complete, and that the ideas of the invention can be fully communicated to ordinary technicians. be.

As used herein, terms such as "include" or "have" are intended to specify the existence of features, numbers, stages, actions, components, parts or combinations thereof described herein. It should be understood that it does not preclude the existence or addition of one or more other features or numbers, stages, actions, components, components or combinations thereof. .. Also, if parts such as layers, membranes, regions, plates, etc. are "above" other parts, it is not only when they are "directly above" other parts, but there are other parts in between. Including some cases. Conversely, if a part such as a layer, membrane, area, or plate is "below" another part, it is not only "just below" the other part, but another part in between. Including some cases.

Unless otherwise stated, all numbers, values and / or representations used herein to represent the amounts of ingredients, reaction conditions, polymer compositions and formulations are those in which such numbers are essentially different. It should be understood as being modified by the term "about" in all cases, as it is an approximation that reflects the various uncertainties of the measurements that occur in obtaining such values. Also. When numerical ranges are disclosed herein, such ranges are continuous and include all values from the minimum to the maximum of such ranges, unless otherwise noted. .. When such a range refers to an integer, all integers including the minimum value to the maximum value including the maximum value are included unless otherwise specified.

As used herein, the wheel balance weight composition is a composition capable of forming a balance weight attached to one part of the wheel in order to adjust the balance of the static center of gravity and / or the dynamic center of gravity of the wheel. Not limited.

The composition for wheel balance weight according to the embodiment of the present invention can include a base resin containing a styrene resin and an ion-crosslinked elastic body, a stainless steel (SUS) powder, and a filler.

Preferably, 700 to 1,000 parts by weight of the stainless steel (SUS) powder and 3 to 10 parts by weight of the filler can be contained based on 100 parts by weight of the base resin. Further, the base resin can contain 80 to 90% by weight of the styrene resin and 10 to 20% by weight of the ion-crosslinked elastic body.

A more specific description of the resin base contained in the wheel balance weight composition according to the present invention is as follows.

(1) Styrene-based resin The styrene-based resin according to an embodiment of the present invention is a basic raw material for a wheel balance weight composition, and has excellent mechanical properties such as bending resistance, excellent heat resistance, and wear resistance. If there is no deformation in appearance even under high load, then there is no limitation.

The styrene-based resin can include an elastic segment and a styrene block copolymerized at one end or both ends of the elastic segment. The elastic segment can be polymerized from those selected from the group consisting of ethylene, propylene, butylene, butadiene, isoprene and combinations thereof. Further, a styrene block polymerized from styrene can be located at both ends of the polymerized segment by polymerization or the like to form a block copolymer.

The styrene-based resin is preferably styrene-ethylene / butylene-styrene (Stylene-Ethylene / Butylene-Styrene; SEBS), styrene-butadiene-styrene (Stylene-Butadie-Stylene; SBS), styrene-isoprene-styrene (Styrene). -Isoprene-Styrene; SIS), styrene-ethylene / propylene-styrene (Stylene-Ethylene / Propyrene-Stylerene; SEPS) or styrene-isoprene / butadiene-styrene (Styrene-Isoprene / Butadiene-Styrene; SIBS).

The styrene-based resin is preferably 80 to 90% by weight of the total base resin. If it is less than 80% by weight, the bending resistance, heat resistance and internal wear resistance are lowered, and if it is more than 90% by weight, the specific gravity may be lowered at the time of extrusion of the composition and the extrusion moldability may be lowered.

(2) Ion-crosslinkable elastic body The ion-crosslinkable elastic body according to the embodiment of the present invention is an excellent machine with improved bending resistance to extruded material while having excellent elastic force similar to that of crosslinked rubber. As long as it has physical characteristics and excellent bending strength, it is not limited to the following.

The ion-crosslinkable elastic body can be a copolymer of EPDM (Ethylene polypropylene dieene monomer) and a carboxylic acid monomer. Preferably, it may be a graft copolymer obtained by copolymerizing the EPDM and the carboxylic acid monomer.

The carboxylic acid monomer can be a carboxylic acid compound having 3 to 10 carbon atoms, preferably acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, glutaconic acid. , Itaconic acid and any one or more selected from the group consisting of these anhydrides.

Copolymerization can be carried out for the production of an ion-crosslinkable elastic body according to an embodiment of the present invention, and the copolymerization can be carried out by a usual method. As an example of the present invention, a polymerization initiator can be used in the process of copolymerizing EPDM and a carboxylic acid monomer. Peroxides can be used as the polymerization initiator, preferably dicumyl peroxide, 2,5-bis (terrary butyl peroxy) -2,5-dimethylhexane, and bis (terrific butyl). Peroxyisobutyl) benzene and any one or more selected from the group consisting of combinations thereof may be included. Further, as an embodiment of the present invention, a solvent can be further contained in the copolymerization process. The copolymerizing solvent may contain any one or more selected from the group consisting of xylene, acetone and ethanol. As an embodiment of the present invention, the graft copolymer can be extracted and separated from the solvent after the copolymerization. The graft copolymer can also be extracted by a Soxhlet extraction method.

The ion-crosslinked elastic body can contain 98% by weight to 98.55% by weight of EPDM and 1.45% by weight to 2.00% by weight of a carboxylic acid monomer. When the carboxylic acid monomer is graft-copolymerized in an amount of less than 1.45% by weight, the high temperature flowability may increase and the extrudability and moldability may be deteriorated. On the contrary, when the carboxylic acid monomer is graft-copolymerized in excess of 2.00% by weight, the dispersity and the extrudability may decrease due to the difference in flowability from the styrene resin.

The ion-crosslinked elastic body is preferably 10 to 20% by weight based on the total base resin. If it is less than 10% by weight, the flexibility is reduced when the composition is extruded, and if it is more than 20% by weight, the dispersibility in the composition is lowered due to the low flowability and the relatively high melting point. The surface may become rough during extrusion and the extrusion may be interrupted during extrusion.

More specifically, the stainless steel (SUS) powder contained in the wheel balance weight composition according to the present invention will be described below.

The stainless steel (SUS) powder according to one embodiment of the present invention is not limited as long as it can increase the specific gravity of the wheel balancing weight containing the wheel balance weight composition and suppress the generation of rust.

The stainless steel (SUS) can be an austenite-based, a ferrite-based or a martensite-based. Specifically, the stainless steel (SUS) can be selected and used from commercialized SUS304, 340, 410, 430, 600, 630 series products and the like.

The stainless steel (SUS) powder is preferably 700 to 1,000 parts by weight based on 100 parts by weight of the base resin. If it is less than 700 parts by weight, defects in bending resistance, flowability and extrudability may occur, and if it exceeds 1000 parts by weight, there may be a problem that the specific gravity becomes low when the composition is extruded.

More specifically, the filler contained in the wheel balance weight composition according to the present invention will be described below.

The filler according to one embodiment of the present invention is not limited as long as it can increase the adhesive specific surface area and improve the interfacial interaction between the base resin and stainless steel (SUS).

The filler can be calcium carbonate, medium calcium carbonate, precipitated calcium carbonate and solution calcium carbonate depending on the intended nature of the wheel balance weight composition. The filler may be preferably precipitated calcium carbonate, and more preferably selected from the group consisting of glued calcium carbonate, hard calcium carbonate and combinations thereof among the precipitated calcium carbonates. The glued calcium carbonate can have a cubic particle form of calcite crystals and can be the commercialized TC, SF, TCR, TSP, TPT and TOT. Further, the hard calcium carbonate can have a spindle particle type of calcite crystals, and may be TL-1000, TL-2000 and TL-3000 which have been commercialized.

The filler may be surface treated with a fatty acid or a metal salt thereof. Specifically, when the surface is treated with a fatty acid, the surface can be treated with one selected from the group consisting of saturated fatty acids, unsaturated fatty acids and combinations thereof. At this time, the saturated fatty acid can be preferably a saturated fatty acid containing capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and araquinic acid, and the unsaturated fatty acid is oleic acid, ellagic acid, linolenic acid and lysinolic acid. Can be unsaturated fatty acids containing. Further, when the surface is treated with a metal salt, the surface can be treated with an alkali metal salt, an alkali metal salt of a resin acid, or a material selected from the group consisting of a combination thereof.

The filler is preferably 3 to 10 parts by weight based on 100 parts by weight of the base resin. If it is less than 3 parts by weight, the adhesive specific surface area, interfacial interaction and strength may decrease, and if it exceeds 10 parts by weight, bending resistance and extrudability may decrease.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are merely examples to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example 1
An example is a wheel balance composition produced with the composition as shown in Table 1 below.
Specifically, as the base resin, a composite resin produced by mixing 90% by weight of a styrene resin and 10% by weight of an ion-crosslinked elastic body was used. Styrene-ethylene / butylene-styrene (Stylene-Ethylene / Butylene-Stylene; SEBS) is used as the styrene-based resin, EPDM (Ethrene copperylene monomer) is used as the ion-crosslinked elastic body, and itacon is used as the carboxylic acid monomer. An acid produced by copolymerizing with a weight ratio of 98: 2 was used. Further, as the stainless steel (SUS) powder, SUS630 was used in 900 parts by weight based on 100 parts by weight of the base resin. Further, as the filler, calcium carbonate surface-treated with an alkali metal salt in 5 parts by weight based on 100 parts by weight of the base resin was used.

Example 2
When compared with Example 1, it was produced in the same manner as in Example 1 except that a composite resin produced by mixing 85% by weight of a styrene resin and 15% by weight of an ion-crosslinked elastic body was used as a base resin.

Comparative Example 1
When compared with Example 1, it was manufactured in the same manner as in Example 1 except that an engineering plastic was used as the base resin instead of the styrene resin and no filler was used.

Comparative Example 2
When compared with Example 2, it was manufactured in the same manner as in Example 2 except that an engineering plastic was used as the base resin instead of the styrene resin and no filler was used.

＊単位：重量部

* Unit: Weight part

Experimental example 1. Measurement of Extrusion Moldability The composition of Example 1 obtained in the above-mentioned production example was extruded under the following conditions. Further, extrusion was carried out in the same process except that the composition of Example 1 was replaced with the compositions of Example 2 and Comparative Examples 1 and 2, respectively.

Extruding equipment: Thermo [0050] SCIENTIFIC / HAAKE
Extrusion temperature condition: Input part of extrusion equipment; 200 ° C / Inside of extrusion equipment; 240 ° C / Discharge part of extrusion equipment; 230 ° C
Extruding equipment screw speed: 100 rpm

Further, the extruded product was evaluated under the following conditions, and the results are shown in Table 2 below.
◎ (Good): There are no cracks or protrusions on the surface of the extruded product.
Δ (improvement required): Fine cracks or protrusions are generated on the surface of the extruded product.
× (Defective): Breakage due to cracks or rough surface and protrusions occur during extrusion.

Experimental example 2. Flexibility test The extruded product obtained in Experimental Example 1 was cooled at room temperature and cut into a size of 300 mm × 150 mm × 100 mm to obtain a test piece, and the force was continuously applied until cracks were generated at both ends of the test piece. Flexibility was evaluated based on the presence or absence of cracks in the test piece. The results are shown in Table 2 and FIG. 3 below.

According to the results of Table 2 and FIG. 3, the balancing weight provided by the present invention is excellent in extrusion moldability because the specific gravity is similar to the existing balancing weight but there are no cracks or protrusions on the surface of the extruded product. It was confirmed that no cracks were formed at both ends and the bending resistance (see FIG. 3) was excellent.

On the other hand, in the cases of Comparative Examples 1 and 2 in which the base resin does not contain a styrene resin and the surface-coated filler according to the embodiment of the present invention is not contained, the flexibility and elasticity in the extrusion molding process. Since the force was low, it was confirmed that the extrudability was lowered and the bending resistance was inferior.

Further, referring to FIG. 2, the balancing weight extruded product provided in the present invention can be cut and adhered by an automated process, and is used as a weight of less than 1 g, so that the accuracy is remarkable. Improved. In addition, it was confirmed that when applied to an automobile wheel, it adhered well along the curved surface of the automobile wheel due to its excellent followability, and that corrosion and peeling phenomena were not observed even after long-term use.

Claims (11)

Styrene resin and
A base resin containing a graft copolymer obtained by reacting EPDM (Ethylene propylene diene rubber ) with a carboxylic acid monomer using a peroxide ;
Stainless steel (SUS) powder; and contains filler,
A composition for wheel balance weights in which the filler is selected from the group consisting of glued calcium carbonate, hard calcium carbonate and combinations thereof. Based on 100 parts by weight of the base resin
The composition for wheel balance weight according to claim 1, which comprises 700 to 1,000 parts by weight of the stainless steel (SUS) powder; and 3 to 10 parts by weight of the filler. The base resin is
80-90% by weight of the styrene resin; and
10 to 20% by weight of the graft copolymer
The composition for a wheel balance weight according to claim 1. The styrene resin is
The composition for a wheel balance weight according to any one of claims 1 to 3, comprising an elastic segment; and a styrene block copolymerized at one end or both ends of the elastic segment. The composition for wheel balance weight according to claim 4, wherein the elastic segment is polymerized from those selected from the group consisting of ethylene, propylene, butylene, butadiene, isoprene and combinations thereof. The composition for wheel balance weight according to any one of claims 1 to 5, wherein the carboxylic acid monomer for the graft copolymer has 3 to 10 carbon atoms. The graft copolymer is
The wheel balance weight according to any one of claims 1 to 6, wherein the EPDM is contained in an amount of 98% by weight to 98.55% by weight; and the carboxylic acid monomer is contained in an amount of 1.45% by weight to 2.00% by weight. Composition for. The composition for wheel balance weight according to any one of claims 1 to 7, wherein the filler is surface-treated with a fatty acid , a resin acid, or a metal salt thereof. The fatty acids are saturated fatty acids (eg, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and araquinic acid ) ; unsaturated fatty acids (eg, oleic acid, elaidic acid, linolenic acid and linolenic acid ) ; and these. The composition for wheel balance weights according to claim 8, which is selected from the group consisting of combinations. The composition for wheel balance weight according to claim 8 or 9, wherein the metal salt is selected from the group consisting of an alkali metal salt of a fatty acid, an alkali metal salt of a resin acid, and a combination thereof. A wheel balancing weight obtained by extruding the composition for a wheel balance weight according to any one of claims 1 to 10.

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