KR100466384B1 - Thermoplastic elastomer composition for shock absorbing - Google Patents

Abstract

The present invention relates to a thermoplastic elastomer composition for shock absorption, which is easy to mold, recycles scrap, and has a high impact absorption ability against a large impact. The carbon black, hard coal, clay, and talc may be used in 50 to 100 parts by weight of butyl rubber. 30 to 70 parts by weight of a filler selected from the group consisting of silica, mistron vapor or a mixture of two or more thereof, 1 to 2 parts by weight of stearic acid, 3 to 7 parts by weight of zinc oxide, and 40 to 60 parts by weight of process oil And 2 to 7 parts by weight of a crosslinking agent selected from the group consisting of a mixture of sulfur and a vulcanization accelerator, a mixture of a phenol resin and a halogen donor, and a mixture of a peroxide and a peroxide activator.

Description

Thermoplastic elastomer composition for shock absorbing

The present invention relates to a thermoplastic elastomer composition for shock absorption. More specifically, the present invention relates to a thermoplastic elastomer composition for impact absorption, which is easy to mold, recycles scrap, and has a high impact absorption ability against large impacts.

For shock absorbing (or `` buffering '') materials, such as rubber, have been widely used. There are many kinds of rubber, natural or synthetic, especially natural rubber, which has been used for various purposes in human life for a long time. In particular, rubber has a high elasticity and has been widely used particularly for shock absorption and the like. In recent years, the development of the vulcanizing process has increased the utilization of rubber and has become one of the indispensable materials for human life. However, in spite of its excellent elasticity and durability, rubber has a long molding time for molding into a predetermined shape, and once broken, it is almost impossible to recycle scrap, which is a residue. It is not easily decomposed, but it remains for a long time and is the main culprit of environmental pollution. In the case of rubber, in particular vulcanized rubber, there is a problem that causes air pollution even if it is to be disposed by incineration.

With the development of the industry, the demand for shock absorbing materials and the need for environmental protection are increasing. Therefore, relying on rubber is no longer a desirable solution. Therefore, the development of new shock absorbing materials is required. .

An object of the present invention was invented to solve the problems that may occur when using a conventional rubber material, the molding time is short, the scrap can be recycled, lightweight, and can be molded by injection molding It is to provide a new impact-absorbing thermoplastic elastomer composition that can improve productivity and recycle the product.

The thermoplastic elastomer composition for shock absorbing according to the present invention is a filler selected from the group consisting of carbon black, hard coal, clay, talc, silica, mistron vapor or a mixture of two or more thereof in 50 to 100 parts by weight of butyl rubber. Parts by weight, 1 to 2 parts by weight of stearic acid, 3 to 7 parts by weight of zinc oxide, 40 to 60 parts by weight of process oil, a mixture of sulfur and a vulcanization accelerator, a mixture of a phenol resin and a halogen donor, a peroxide and a peroxide active aid It comprises 2 to 7 parts by weight of the crosslinking agent selected from the group consisting of a mixture of a.

The impact-absorbing thermoplastic elastomer composition may further include 1 to 30 parts by weight of a reinforcing resin such as a thermoplastic vinyl resin such as polypropylene to enhance mechanical properties.

The shock absorbing thermoplastic elastomer composition may further include 0.5 to 1.5 parts by weight of an anti-aging agent for reducing the change over time.

Hereinafter, the present invention will be described in detail with reference to specific examples.

The thermoplastic elastomer composition for shock absorbing according to the present invention is a filler selected from the group consisting of carbon black, hard coal, clay, talc, silica, mistron vapor or a mixture of two or more thereof in 50 to 100 parts by weight of butyl rubber. Parts by weight, 1 to 2 parts by weight of stearic acid, 3 to 7 parts by weight of zinc oxide, 40 to 60 parts by weight of process oil, a mixture of sulfur and a vulcanization accelerator, a mixture of a phenol resin and a halogen donor, a peroxide and a peroxide active aid Characterized in that it comprises 2 to 7 parts by weight of the crosslinking agent selected from the group consisting of a mixture of.

Butyl rubber as a component constituting the basis of the impact-absorbing thermoplastic elastomer composition according to the present invention, and functions to constitute the composition including other components. The butyl rubber is a binary copolymer of isobutylene and diene. Butyl rubber is excellent in weather resistance, heat resistance, and aging resistance, is excellent in ozone resistance and oxidizing agent, is excellent in sun resistance, is also resistant to salt, and has good flex resistance. In addition, it is excellent in electrical insulation, excellent in wear resistance, cold resistance, small elasticity, and known to those skilled in the art to be commercially available. The butyl rubber is preferably used in the range of 50 to 100 parts by weight. When the content of butyl rubber is less than 50 parts by weight, the content of butyl rubber may be too small, so that the shock absorbing function may be weakened. When the content of the butyl rubber is more than 100 parts by weight, the content of other components is reduced as a whole, so as to absorb shock. There may be a problem that deterioration of physical properties.

The impact-absorbing thermoplastic elastomer composition may further include 1 to 30 parts by weight of a reinforcing resin such as a thermoplastic vinyl resin such as polypropylene to enhance mechanical properties. As the reinforcing resin, polypropylene may be preferably used. Polypropylene is a polymer of propylene, which occurs with ethylene when decomposing naphtha in petrochemical plants. A Ziegler-Natta catalyst (typically a complex salt consisting of titanium trichloride and diethylaluminum chloride) is made in a nucleic acid, and propylene is easily synthesized by passing propylene at about 70 ° C. and 5 atm. It has an isotactic structure, and accordingly, methyl groups are arranged in the same direction as the structural formula. Melting point is 165 ℃, continuous use at 110 ℃ is possible under load. The density is 0.9-0.91 and the crystallinity is large, but after shaping | molding, it falls to 70% or less. The electrical properties are excellent because they consist only of carbon and hydrogen, which is comparable to polyethylene. Applications are as well known as packaging films, stretched tapes, fibers, pipes, daily necessities, toys, industrial parts, containers, and the like, which can be purchased and used commercially by those skilled in the art. The content of the polypropylene is also relative to the butyl rubber, the content of the polypropylene can be appropriately adjusted according to the physical properties of the impact-absorbing thermoplastic elastomer composition according to the present invention to obtain repeated experiments (trial and error) By the method) and the like.

The butyl rubber further includes a filler selected from the group consisting of carbon black, hard coal, clay, talc, silica, mistron vapor, or a mixture of two or more thereof. The filler is a substance applied for the purpose of anti-aging, reinforcement and increase in the practical use of rubber or plastic, and the carbon added to obtain the strength required when manufacturing automobile tires from rubber, for example, corresponds to the filler. do. When the filler is included in less than 30 parts by weight, the required strength can not be obtained, there is a problem that the expensive resin components are used too much, it is not economical, more than 70 parts by weight is formed into a suitable shape, etc. There may be a problem that is not done properly.

The stearic acid functions to facilitate the activation of the vulcanization accelerator while increasing the compatibility with rubber by forming metal complexes and metal soaps with metal oxides such as zinc oxide. When the stearic acid is included in less than 1 part by weight, there may be a problem in that the amount of formation of the metal complex compound is small to reduce the vulcanization accelerator activation, if it exceeds 2 parts by weight, the metal salt is formed in excess to increase the vulcanization accelerator activation and viscosity Although the workability is increased by lowering, there may be a problem in that physical properties such as tensile strength, sinterability, and compression set are reduced.

The zinc oxide forms a metal complex compound or a metal soap with a fatty acid such as stearic acid, thereby increasing compatibility with rubber and facilitating activation of the vulcanization accelerator. When the zinc oxide is included in less than 3 parts by weight, there is a problem that the amount of formation of the metal complex compound is small, there is a problem of lowering the vulcanization accelerator activation, if it exceeds 7 parts by weight, the metal salt is formed in excess to increase the vulcanization accelerator activation However, workability is increased by lowering the viscosity, but there may be a problem in that physical properties such as tensile strength, sinterability, and compression set decrease.

The process oil is used to increase the processability of the impact-absorbing thermoplastic elastomer composition according to the present invention. Preferably, paraffin-based oil (for example, White oil # 1900 of Michang Petrochemical Co., Ltd., Korea, may be used.When the process oil is included in an amount of less than 40 parts by weight, the processability of the composition is lowered, and thus, it is not easy to manufacture a processed product having a beautiful appearance. There may be a problem that does not, and exceeding 60 parts by weight may have a problem such that the surface of the workpiece is contaminated with too much oil.

The crosslinking activator may be selected from the group consisting of a mixture of sulfur and a vulcanization accelerator, a mixture of a phenol resin and a halogen donor, and a mixture of a peroxide and a peroxide activator. This crosslinks the reinforcing resins such as butyl rubber and vinyl resin, thereby causing crosslinking between the main chains of the resins, thereby enhancing physical properties such as higher mechanical properties. The mixture of sulfur and a vulcanization accelerator as the crosslinking activator may be a vulcanization accelerator (eg, tetramethyl thiuram disulfide (TMTD) that promotes the crosslinking of sulfur and sulfur, Orichel TT; Oriental Chemical, South Korea). Corporation) may be used in combination. Sulfur and vulcanization accelerator in the cross-linking activator is preferably used in an amount of 1.5 to 2.0 sulfur, 0.5 to 1.5 parts by weight of vulcanization accelerator, the deviation of the lower limit of this range may have a problem that does not sufficiently crosslinking, Out of the upper limit of the range is too much crosslinking occurs due to excessive crosslinking of the composition obtained, too hard properties, there may be a problem that adversely affects the physical properties due to the remaining of the unreacted crosslinking active agent. The mixture of the phenol resin and the halogen donor as the crosslinking activator is a conventional phenol resin (e.g., alkylphenol-formaldehyde resin, KPC-F1500 (KPC-F1500; Kolon Oil Co., Ltd.)) and tin chloride. Mixtures of (SnCl ₂ .2H ₂ O) can be used. The mixture of the phenol resin and the halogen donor is preferably used in an amount of 4 to 6 parts by weight of the phenol resin and 0.5 to 1.5 parts by weight of the halogen donor, and beyond the lower limit of this range may have a problem that the crosslinking does not occur sufficiently. To the outside of the upper limit of this range, too much crosslinking may result in excessive crosslinking of the composition to be obtained, which may result in too hard physical properties, and may have a problem of adversely affecting physical properties due to the remaining of unreacted crosslinking activator. Mixtures of peroxides and peroxide active aids as the crosslinking activator may also be used in the same or similar concept as the crosslinking activators as described above. As the peroxide, bis- (ti-butylperoxyisopropyl) benzene (for example, Perkadox 14-40B, German Akzo Nobel company name) may be used. In addition, zinc di-n-butyldithiocarbamate (for example, Taesung Chemical Co., Ltd., Korcel BZ) may be used as the peroxide activator.

The shock absorbing thermoplastic elastomer composition may further include 0.5 to 1.5 parts by weight of an anti-aging agent to reduce the change over time. Specifically, the anti-aging agent can be commercially purchased and used, such as Irganox (CIVA irganox, Ciba-Geigy Co., Ltd.), and can be easily understood by those skilled in the art. Absorption, removal of free radicals, and blocking of ultraviolet rays, etc., the organic components inhibit the aging of the resin to extend the life of the resin, and to suppress the degradation of physical properties.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described.

The following examples are intended to illustrate the invention and should not be understood as limiting the scope of the invention.

Comparative Examples and Examples 1 to 4

Measurement of Changes in Physical Properties with Contents of Butyl Rubber and Mixing Ratio of Reinforced Resin

A thermoplastic resin composition was prepared as shown in Table 1 below, and Shore hardness, tensile strength, elongation rate, and resilience were measured according to the KS M6518 vulcanized rubber physical test method, and are also shown in Table 1 below.

division Comparative example Example 1 Example 2 Example 3 Example 4 Butyl rubber 100 80 70 60 50 Polypropylene - 20 30 40 50 Stearic acid 1.5 1.5 1.5 1.5 1.5 Zinc oxide 5.0 5.0 5.0 5.0 5.0 Carbon black 50 50 50 50 50 Irganox 2 2 2 2 2 Paraffin Process Oil - 50 50 50 50 Phenolic Resin - 5.0 5.0 5.0 5.0 SnCl ₂ 2H ₂ O - 1.0 1.0 1.0 1.0 Acc. TMTD 1.0 - - - - brimstone 1.75 - - - - Shore A 61 51 62 73 82 Tensile Strength (MPa) 15.5 4.8 5.9 6.7 7.8 Elongation (%) 600 500 450 300 450 Resilience (%) 26.5 29.3 31.4 39.3 40.5

Example 3, 5-6

Measurement of changes in physical properties according to crosslinking activator

A thermoplastic resin composition was prepared as shown in Table 2 below, and Shore hardness, tensile strength, elongation rate, rebound elasticity, and the like were measured, and are also shown in Table 2 below.

division Example 2 Example 5 Example 6 Butyl rubber 70 70 70 Polypropylene 30 30 30 Stearic acid 1.5 1.5 1.5 Zinc oxide 5.0 5.0 5.0 Carbon black 50 50 50 Irganox 2 2 2 Paraffin Process Oil 50 50 50 Phenolic Resin 5.0 - - SnCl ₂ 2H ₂ O 1.0 - - Acc. TMTD - 1.0 - brimstone - 1.75 - Acc. BZ - - One peroxide - - 5 Shore A 62 60 64 Tensile Strength (MPa) 5.9 5.6 6.6 Elongation (%) 450 500 350 Resilience (%) 31.4 30.8 33.5

Examples 7-12

Measurement of Changes in Physical Properties According to Fillers

As shown in Table 3 below, a thermoplastic resin composition was prepared, and Shore hardness, tensile strength, elongation rate, rebound elasticity, and the like were measured, and are also shown in Table 3 below.

division Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Butyl rubber 70 70 70 70 70 70 Polypropylene 30 30 30 30 30 30 Stearic acid 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 5.0 5.0 5.0 5.0 5.0 5.0 Carbon black 50 - - - - - Mistron Vapor - 50 - - - - Carbon black - - 50 - - - Carbon black - - - 50 - - Carbon black - - - - 50 - Carbon black - - - - - 50 Irganox 2 2 2 2 2 2 Paraffin Process Oil 50 50 50 50 50 50 Phenolic Resin 5.0 5.0 5.0 5.0 5.0 5.0 SnCl ₂ 2H ₂ O 1.0 1.0 1.0 1.0 1.0 1.0 Shore A 62 60 58 62 63 61 Tensile Strength (MPa) 5.9 5.6 5.2 5.8 5.7 5.6 Elongation (%) 450 440 480 490 410 420 Resilience (%) 31.4 32.8 34.8 32.6 32.1 31.9

As a result of combining the embodiments, as shown in Tables 1 to 3, the impact-absorbing thermoplastic elastomer composition according to the present invention increases the resilience as the content of the reinforcing resin to the butyl rubber increases, in the case of hardness, reinforcement As a result of using polypropylene as a resin, when the content of polypropylene is very low (less than 20 parts by weight, Example 1), the hardness is low, but when the content of polypropylene is increased, the hardness becomes higher and exceeds 40 parts by weight ( In Examples 3 and 4) it was confirmed that the hardness is very high compared to the case of using only butyl rubber (Comparative Example). Therefore, it was confirmed that it is possible to adjust the content of the reinforcing resin to obtain the desired hardness. In addition, in the case of the tensile strength, it was confirmed that the highest tensile strength in the case of using only butyl rubber (comparative example). Therefore, it was confirmed that it can be achieved by increasing the content of butyl rubber in order to obtain the desired tensile strength. The elongation rate also shows the highest elongation rate when only butyl rubber is used (comparative example), and the elongation rate decreases as the content of butyl rubber decreases, but rather when the content of butyl rubber and reinforcing resin is equivalent (Example 4). It was again shown a tendency to increase, it was confirmed that the elongation can also be controlled by controlling the content of butyl rubber. Accordingly, it was confirmed that a thermoplastic elastomer composition having various physical properties can be obtained by appropriately adjusting the mixing ratio of butyl rubber and reinforcing resin.

In addition, even when the type and the amount of the crosslinking activator are different, the degree of hardness, tensile strength, elongation rate and resilience, etc. are different, but it is confirmed that there is no significant difference. It was confirmed that the present invention can be used to prepare a thermoplastic elastomer composition for shock absorption according to the present invention. However, among the crosslinking agents used in the above examples, sulfur and a vulcanization accelerator showed high values evenly in all respects, thereby making it possible to prepare thermoplastic elastomer compositions having higher utilization.

In addition, even in the case of different types of fillers, although there are differences in degree in hardness, tensile strength, elongation and rebound elasticity, it can be seen that they do not show any significant difference. It was confirmed that the present invention can be used to prepare a thermoplastic elastomer composition for shock absorption.

Accordingly, the present invention provides a new impact-absorbing thermoplastic elastomer composition capable of recycling scrap by using thermoplastic resins, making it lightweight, injection molding, and improving productivity, and recycling of products. It is effective.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (3)

50 to 100 parts by weight of butyl rubber 30 to 70 parts by weight of a filler selected from the group consisting of carbon black, hard coal, clay, talc, silica, mistron vapor or a mixture of two or more thereof, 1-2 parts by weight of stearic acid, zinc oxide 3 to 7 parts by weight, 40 to 60 parts by weight of process oil and a mixture of sulfur and vulcanization accelerator, a mixture of phenol resin and halogen donor, and a mixture of peroxide and peroxide activator Shock absorbing thermoplastic elastomer composition comprising 2 to 7 parts by weight. The method of claim 1, The thermoplastic elastomer composition for shock absorbing, characterized in that the impact absorbing thermoplastic elastomer composition further comprises 1 to 30 parts by weight of a reinforcing resin such as thermoplastic vinyl resin. The method of claim 1, The shock absorbing thermoplastic elastomer composition further comprises 0.5 to 1.5 parts by weight of the anti-aging agent to reduce the change over time in the shock absorbing thermoplastic elastomer composition.