KR101171284B1 - Silicon/natural rubber blends and products using the same - Google Patents

Abstract

The present invention relates to a silicone / natural rubber blend and a molded article using the same, more specifically, a silicone rubber containing a vinyl group; Natural rubber; And a silicone / natural rubber blend comprising a crosslinking agent and a molded article using the same. According to the present invention, the silicone rubber includes a vinyl group having a double bond, thereby improving crosslinking properties and enabling sulfur crosslinking. In addition, natural rubber is blended and has excellent mechanical properties.

Silicone rubber, natural rubber, blends, crosslinks, dustproof

Description

SILICON / NATURAL RUBBER BLENDS AND PRODUCTS USING THE SAME}

The present invention relates to a silicone / natural rubber blend and a molded article using the same, and more particularly include a vinyl group in the silicone rubber, blending the natural rubber, the sulfur cross-linking as well as excellent mechanical properties such as silicone / A natural rubber blend and a molded article using the same.

Silicone rubber is applied in various fields. Silicone rubber is used, for example, as a heat-resistant material, as well as heat-resistant materials, insulating materials such as adhesives and various electronic devices such as transistors, integrated circuits, and memory devices.

 Silicone rubber is used in combination with other ingredients. For example, it is commercialized as a blend (composite) of silicone / EPDM, silicone / fluorine, etc. in combination with ethylene propylene rubber (EPDM), fluorine, or the like. In addition, silicone rubber may be mixed with fillers such as silica for the purpose of reinforcing mechanical properties. Since silicone rubber has Si-O bond in the molecule, it has better heat resistance and aging resistance than other rubber materials.

However, silicone rubber does not have a double bond in the backbone due to its chemical structure, which makes it difficult to cross sulfur cross-linking and poor durability. In addition, silicone rubber is expensive and physical properties are limited to use. Silicone rubber has a problem in that its damping property is weak and its mechanical properties such as tensile strength, elongation, and hardness are poor, for example, its use is limited to dustproof rubber materials.

The present invention is to solve the problems of the prior art as described above, by including a vinyl group in the silicone rubber, by blending natural rubber (sulfur cross-linking) is possible, as well as mechanical properties, etc. The object is to provide a good silicone / natural rubber blend and molded articles comprising the same.

The present invention to achieve the above object,

Silicone rubber containing a vinyl group;

Natural rubber; And

A silicone / natural rubber blend is provided that includes a crosslinking agent.

The present invention also provides a molded article comprising the silicone / natural rubber blend according to the present invention.

According to the present invention, a silicone group includes a vinyl group having a double bond, thereby improving crosslinking properties and having sulfur crosslinking. In addition, natural rubber is blended (blending) has excellent effects such as mechanical properties.

Hereinafter, the present invention will be described in detail.

The silicone / natural rubber blend according to the present invention includes silicone rubber (SR), natural rubber (NR) and a cross-linking agent.

As described above, the silicone rubber has good heat resistance due to the Si-O bond in the molecule. However, silicone rubber does not have a double bond in the main chain due to its chemical structure, and thus, sulfur cross-linking is difficult, and its durability is inferior to that of other rubbers. In addition, natural rubber has C and H in the molecule due to its chemical structure, and has a double bond (-C = C-) in the main chain, and thus has excellent properties such as durability, abrasion resistance, and shock absorption, but the use temperature is high. Heat resistance is weak as 100 degrees C or less.

The silicone / natural rubber blend according to the present invention has heat resistance of silicone rubber, durability, abrasion resistance, and shock absorption of natural rubber.

At this time, in order to be compounded to have strengths of the two rubbers, compatibility and the like should be considered. In particular, it is necessary to consider a technical means capable of providing a crosslinking property without a phase separation phenomenon when the two rubbers are mixed. Specifically, silicon rubber is difficult to crosslink sulfur because there is no double bond in the main chain, and technical means for solving this problem should be devised. In addition, the blend in which the two rubbers are combined must have excellent mechanical properties such as tensile strength, elongation, and hardness in order to be usefully used as a dustproof rubber material.

The silicone / natural rubber blend according to the present invention has been devised for the above technical means and includes silicone rubber, natural rubber and a crosslinking agent, wherein the silicone rubber contains at least one vinyl group in a molecule. Silicone rubber has excellent crosslinking properties due to the presence of vinyl groups, and in particular, sulfur crosslinking is possible. Specifically, the silicone rubber undergoes a crosslinking reaction through sulfur due to the presence of a vinyl group having a double bond, and complexes with natural rubber without phase separation. In addition, it has excellent mechanical properties such as tensile strength, elongation and hardness as well as durability, impact absorption, dust resistance, etc. by the composite with natural rubber.

In the present invention, the silicone rubber is included herein as long as it has at least one vinyl group in the molecule. For example, the silicone rubber may include at least one structural unit represented by the following formula (1).

[Formula 1]

(Wherein R ₁ is an alkyl group or a phenyl group and m is an integer of 1 or more).

For example, the silicone rubber may be selected from siloxane represented by the following Chemical Formula 2.

[Formula 2]

(Wherein R ₁ is an alkyl group or a phenyl group, R ₂ and R ₃ are an alkyl group, a fluorinated alkyl group or a phenyl group, n and m are integers of 1 or more.)

The alkyl groups constituting R ₁ , R _2, and R ₃ in Chemical Formulas (1 and 2) are not particularly limited, and may be selected from alkyl groups having 1 to 6 carbon atoms, and specific examples thereof include methyl group, ethyl group, and propyl group. Can be mentioned. And the like can be mentioned a fluorinated alkyl group constituting R ₂ and R ₃ in the above formula is, for example, trifluoro propyl _{(-CH 2 CH 2 CF 3)} . In addition, n and m in the above formula may be an integer of 1 or more, for example, an integer of 10 to 3,000. For example, the silicone rubber may be selected from dimethylvinyl siloxane in which R ₁ , R _2, and R ₃ are methyl groups (—CH ₃ ) in Chemical Formula 2.

In addition, the vinyl group is preferably included at a concentration of 0.02 ~ 0.75 mmol / g. Specifically, the vinyl group is preferably graft polymerized at a concentration of 0.02 to 0.75 mmol per 1 g of silicone rubber. In this case, when the concentration of the vinyl group is less than 0.02 mmol / g, crosslinking properties may be lowered and sulfur crosslinking may be difficult. In addition, when the concentration of the vinyl group exceeds 0.75 mmol / g, the hardness may increase, which may degrade the rubber properties. When the concentration of the vinyl group is too large, especially when the peroxide crosslinks, the hardness value becomes too high due to an increase in the crosslinking density, and brittle phenomenon may occur, thereby degrading the rubber properties. The vinyl group is more preferably contained at a concentration of 0.05 to 0.7 mmol / g.

The natural rubber is not particularly limited, but preferably polyisoprene gum is used. Natural rubber is more preferably represented by the following formula (3), it is preferable to use cis-polyisoprene (cis-polyisoprene). In this case, n in Formula 3 is an integer of 1 or more, but is not particularly limited, and may be, for example, an integer of 10 to 10,000.

(3)

(Where n is an integer of 1 or more)

Blend according to the present invention is a composite of the silicone rubber and natural rubber as described above, the crosslinking agent may use one or more selected from the group consisting of sulfur and peroxide. At this time, as described above, the silicone rubber is difficult to crosslink sulfur due to the absence of a double bond. According to the present invention, sulfur crosslinking is possible due to the presence of a vinyl group. Preferably, the crosslinking agent is preferably used by using a mixture of sulfur and peroxide (sulfur / peroxide). According to the present invention, the blend has better mechanical properties (tensile strength, elongation, etc.) in the sulfur / peroxide co-crosslinking system in which sulfur and peroxide coexist. At this time, peroxide and sulfur may be mixed in a weight ratio of 1: 0.2 to 5, but is not limited thereto.

In addition, the amount of the silicone rubber and natural rubber can be adjusted according to the intended use and use. For example, when used as a product that requires heat resistance, the content of silicone rubber may be increased, and when used as a product that requires dustproof or mechanical properties rather than heat resistance, the content of natural rubber may be increased. Although not particularly limited, when used as a dustproof rubber material, silicone rubber and natural rubber may be used in a blend ratio of 3-7: 7-3, more preferably 4-6: 6: 4. In addition, the crosslinking agent may be used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of rubber (a sum of silicon rubber and natural rubber), but is not limited thereto.

In addition, the blend according to the present invention may further include a processing aid for improving processability and physical properties. In this case, the processing aid may be used at least one selected from a zinc-based surfactant and a silane compound. The zinc-based surfactant and the silane compound increase the workability as well as the hardness. Therefore, when used as a product requiring hardness, the zinc-based surfactant and silane compound may be added. Such processing aid is not particularly limited, but may be used in an amount of 2 to 10 parts by weight based on 100 parts by weight of rubber (a sum of silicon rubber and natural rubber).

In addition, the zinc-based surfactant may be one represented by the following formula (4).

[Formula 4]

(Wherein R is an alkyl group of C ₆ to C ₂₂ )

In addition, it is preferable that the silane compound uses the sulfur silane which has a sulfur (S) atom in a molecule | numerator. As the silane compound, for example, bis- (triethoxysilylpropyl) sulfide is preferably used, and specific examples thereof include bis- (triethoxysilylpropyl) monosulfide and bis- (triethoxysilylpropyl) disulfide One or more selected from the group consisting of bis- (triethoxysilylpropyl) trisulfide, bis- (triethoxysilylpropyl) tetrasulfide and the like can be used. Formula 5 shows a structural formula of bis- (triethoxysilylpropyl) disulfide (TESPD) having two sulfur (S) atoms in a molecule.

[Chemical Formula 5]

In addition, the blend according to the present invention is a filler for reinforcing mechanical properties (such as silica), an extender for reducing the price, a dispersant for dispersibility, a mold release agent for mold release with a mold, a vulcanizing agent (vulcanization accelerator), a vulcanization recovery agent And other additives for heat resistance, flame retardancy, color pigments, anti-oxidation, etc. may be added as necessary. At this time, the vulcanizing agent (vulcanization accelerator) is, for example, tetraisobutylthiuram monosulfide, Nt-butyl-2-benzothiazolylsulfenamide (TBBS), tetramethylthiuram disulfide (TMTD) and zinc 2-mercapto Tolu-imidazole and the like.

The silicone / natural rubber blend according to the present invention described above may be variously applied to vibration damping materials for automobiles (eg, dustproof rubbers for engine mounts) or damping materials for various electronic products (TV, LCD, etc.). Can be. In addition, the silicone / natural rubber blend according to the present invention can be used, for example, as a heat-resistant material, an insulating material, as well as a heat dissipating material of various electronic devices (transistors, integrated circuits, memory devices, etc.).

On the other hand, the molded article according to the present invention comprises the silicone / natural rubber blend of the present invention as described above. The molded article according to the present invention is molded from a compound containing at least the silicone / natural rubber blend of the present invention, for example, a dustproof material for preventing / attenuating vibration (for example, a dustproof rubber for an engine mount of an automobile) ) And damping materials of various electronic products.

Hereinafter, the Example of this invention is illustrated. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited.

<Silicone Rubber Vinyl  By existence Crosslinking properties  >

In order to establish an appropriate crosslinking system of silicone rubber (SR), three crosslinking agents (sulfur, peroxide, sulfur / peroxide) were used as shown in Table 1 below. At this time, in order to determine the proper crosslinking characteristics according to the presence of the vinyl group of the silicone rubber (SR), a silicone gum having a vinyl group and a silicone gum having no vinyl group were used. Mixing was carried out using a two-roll mill, but first, silicone rubber (SR) was added and roll milled for 5 minutes, and then silica was added and mixed for 10 minutes. And as shown in the following [Table 1] (ZnO, stearic acid, sulfur, TBBS, TMTD, peroxide) was further added, and then mixed for 15 minutes and blended for 30 minutes to crosslink. At this time, the crosslinking was performed at a pressure of 75,000 psi at a temperature of 170 ℃ using a hot press (hot press).

            <Component and content of silicone blend, unit: parts by weight> ingredient Experimental Example (Content: parts by weight) One 2 3 4 5 6 7 8 9 SR (0.7) 100 - - 100 - - 100 - - SR (0.03) - 100 - - 100 - - 100 - SR (no vinyl) - - 100 - - 100 - - 100 Silica 40 40 40 40 40 40 40 40 40 ZnO 5 5 5 - - - 5 5 5 Stearic acid 2 2 2 - - - 2 2 2 Sulfur 2 2 2 - - - 2 2 2 TBBS One One One - - - One One One TMTD 0.1 0.1 0.1 - - - 0.1 0.1 0.1 Peroxide - - - 2 2 2 2 2 2 Bridge system Sulfur crosslinking Peroxide crosslinking Sulfur / peroxide crosslinking Note 1) TBBS: Nt-butyl-2-benzothiazolylsulfenamide
Note 2) TMTD: Tetramethylthiuram disulfide
Note 3) Peroxide: 2,5-di-methyl-2,5-di-t-butyl peroxyhexane (gum)

In the following examples including the present experimental example (Table 1 above), "SR (0.7)" means silicone rubber (silicon gum) having a vinyl group concentration of 0.7 mmol / g. That is, it means that the vinyl group per 0.7 g of silicone rubber (silicon gum) is contained in 0.7 mmol (mmol). And "SR (0.03)" means that the concentration of the vinyl group is 0.03 mmol / g, "SR (no vinyl)" means a silicone rubber (silicon gum) does not have a vinyl group.

For the silicone blend according to each experimental example prepared as described above, a crosslinking characteristic curve was obtained using a rheometer, and the results are shown in FIGS. 1 to 3. 1 is a crosslinking characteristic curve using sulfur as a crosslinking agent (Experimental Examples 1 to 3), Figure 2 is a crosslinking characteristic curve using peroxide as a crosslinking agent (Experimental Examples 4 to 6), Figure 3 is a sulfur and peroxide as a crosslinking agent Is a crosslinking characteristic curve (Experimental Examples 7 to 9) obtained by mixing and using (sulfur / peroxide).

As shown in Figures 1 to 3, when the vinyl group in the silicone rubber was found to be excellent crosslinking properties. In particular, as compared to FIG. 1, in the case of silicone rubber (Experimental Example 3) in which no vinyl group exists, sulfur crosslinking was not performed, but in the case of silicone rubber (Experimental Example 1) in which vinyl group was contained at an appropriate concentration. It was found that crosslinking occurred. In addition, it can be seen from the present experimental example that the most suitable crosslinking system for silicone rubber is peroxide crosslinking.

On the other hand, Figure 4 attached shows the results of measuring the hardness (Shore A) for the specimen (Experimental Examples 4 to 6) according to the peroxide crosslinking system most suitably evaluated in the Experimental Example. As shown in FIG. 4, when crosslinking the silicone rubber (Experimental Example 4) containing a large number of vinyl groups, it was found that the hardness increased to 91 and became too hard to exhibit the properties of the rubber.

<Silicone / Natural Rubber Blend Manufacturing>

[Examples 1-3 and Comparative Examples 1-5]

As shown in the following [Table 2], silicone rubber (SR) and natural rubber (NR) were blended in an appropriate amount. Mixing was performed using a two-roll mill, but first, silicone rubber (SR) and natural rubber (NR) were put in a roll mill for 5 minutes, and then silica was added and mixed for 10 minutes. At this time, natural rubber (NR) used cis-polyisoprene. And the preparation (ZnO, stearic acid, sulfur, TBBS, TMTD, peroxide) as shown in the following [Table 2] was further added, followed by mixing for 15 minutes and blended for a total of 30 minutes. In this case, a silicone gum having a vinyl group concentration of 0.7 mmol / g was used as the silicone rubber (SR). And the silicone gum which does not have a vinyl group was used, or the natural rubber (NR) was not mix | blended as a comparative example.

          <Component and content of silicone / natural rubber blend, unit: parts by weight> Remarks Comparative Example 1 Comparative Example 2 Example 1 Comparative Example 3 Example 2 Comparative Example 4 Example 3 Comparative Example 5 SR (0.7) 100 - 50 - 50 - 50 - SR (no vinyl) - 100 - 50 - 50 - 50 Natural Rubber (NR) - - 50 50 50 50 50 50 Silica 40 40 40 40 40 40 40 40 Peroxide 2 2 2 2 - - 2 2 Sulfur - - - - 2 2 2 2 ZnO - - - - 5 5 5 5 Stearic acid - - - - 2 2 2 2 TMTD - - - - 0.1 0.1 0.1 0.1 TBBS - - - - One One One One Bridge system Peroxide sulfur Sulfur / peroxide Note 1) Peroxide: 2,5-di-methyl-2,5-di-t-butyl peroxyhexane (gum)
Note 2) TMTD: Tetramethylthiuram disulfide
Note 3) TBBS: Nt-butyl-2-benzothiazolylsulfenamide

Further, after blending as shown in Table 2, the obtained blend was crosslinked at a temperature of 170 ° C. at a pressure of 75,000 psi using a hot press to prepare a blend specimen having a predetermined shape.

<Mechanical Property Evaluation>

Tensile strength (Mpa), elongation (%), tensile modulus (300%, Mpa) and hardness (Shore A) were measured using a universal testing machine for the blended specimens according to the examples and the comparative examples prepared as described above. , The results are shown in the following [Table 3]. And the crosslinking time (min, min) obtained through a rheometer (Rheometer) at 170 ℃ is shown in the following [Table 3].

                      <Mechanical Property Evaluation Results> Remarks Comparative Example 1 Comparative Example 2 Example 1 Comparative Example 3 Example 2 Comparative Example 4 Example 3 Comparative Example 5 The tensile strength
(Mpa) 1.3 4.4 5.6 3.8 4.7 1.5 6.9 1.8 Elongation
(%) 25.7 1329.7 284.7 616.8 1199.5 495.6 1233.6 592.1 Tensile modulus
300% (Mpa) 0.4 1.2 2.1 2 1.1 0.8 1.6 1.1 Hardness
(Shore A) 91.1 61.9 76.4 62.2 50.1 51.3 56.5 52.8 Bridge time
(min) 9.5 8 14 19.5 9.5 12 11 8.5

As shown in [Table 3], it can be seen that according to the present invention, when the vinyl rubber is included in the silicone rubber and the natural rubber is blended with it, physical properties such as tensile strength are evaluated very well.

First, looking at the peroxide crosslinking system (Example 1, Comparative Examples 1 to 3), in the case of Example 1 (polyvinyl group-containing silicone rubber + natural rubber blending), Comparative Example 1 (natural rubber not blended) and comparison It can be seen that it has excellent tensile strength as compared to Example 3 (silicon rubber does not contain a vinyl group). In addition, as compared with Example 1 and Comparative Example 1, it can be seen that the hardness is lowered by the addition of natural rubber. That is, as confirmed in the experimental example, the crosslinking reaction occurs well in the peroxide crosslinking system, the hardness is high, it is difficult to use as a rubber due to the brittle (brittle) phenomenon, as shown in [Table 3] In the peroxide crosslinking system where crosslinking occurs well, it can be seen that hardness is low when natural rubber is blended (Example 1).

In addition, when looking at the sulfur cross-linking system, it can be seen that the sulfur cross-linking by the vinyl group occurs in Example 2 is better evaluated in terms of all physical properties such as tensile strength, elongation, tensile modulus and hardness than the comparative example 4 and the crosslinking time is shortened Could. In addition, as shown in Table 3 above, in the silicone / natural rubber blend, the sulfur / peroxide crosslinking system (Example 3) is applied to the peroxide crosslinking system (Example 1) and the sulfur crosslinking system (Example 2). It was found to have better properties in all physical properties.

On the other hand, in Figure 5, (a) is a SEM photograph of the silicone rubber [SR (no vinyl) used in Comparative Example 2, (b) is used in Comparative Example 3 as a silicone rubber without a vinyl group SEM image of the blend [SR (no vinyl / NR blend) blended with natural rubber, and Figure 5 (c) is used in Example 1, the vinyl group is a silicone rubber and natural rubber blended SEM image of the blend [blend of SR (0.7) / NR] As shown in Fig. 5, phase separation of the blend (vinyl group (b) and comparative example 3) in which no vinyl group is present occurs, but the vinyl group is present. In the case of one blend ((c) in FIG. 5, Example 1), there was almost no phase separation.

<Evaluation of Aging Characteristics>

In order to determine the change in physical properties (aging characteristics) before and after aging, the blend specimens prepared according to the above Examples and Comparative Examples were aged in an oven at 120 ° C. for 48 hours and then physical properties were measured. And the measured value is compared with the physical properties before aging shown in the above [Table 3] and the results are shown as the increase and decrease in the following [Table 4].

                    <Aging characteristics evaluation result (% increase / decrease)> Bridge system Ratio of SR / NR The tensile strength Elongation Tensile modulus Hardness Peroxide Example 1 SR (0.7) / NR
50/50 -23.2% -31.9% 0% + 4.8% Comparative Example 3 SR (no vinyl) / NR
50/50 -23.7% -24.0% 0% + 9.5% sulfur Example 2 SR (0.7) / NR
50/50 -36.2% -40.0% + 36.4% + 15% Comparative Example 4 SR (no vinyl) / NR
50/50 -46.7v -70.0% -100% + 1.6% Sulfur / peroxide Example 3 SR (0.7) / NR
50/50 -29.0% -33.0% + 18.8% + 5.7% Comparative Example 5 SR (no vinyl) / NR
50/50 -44.4% -67.4% -100% + 2.5%

As shown in [Table 4], it can be seen that in the case of the embodiment including the vinyl group in the aging characteristics such as tensile strength, the measured value is decreased and satisfactorily evaluated, and excellent aging characteristics in the sulfur / peroxide crosslinking system as a whole. It can be seen that.

From the above experimental results, it can be seen that the sulfur / peroxide co-crosslinking system using a mixture of sulfur and peroxide is suitable in terms of mechanical properties and overall aging characteristics when preparing a blend of silicon / natural rubber. Based on these results, the sulfur / peroxide co-crosslinking system was fixed and the effects on the processing aids were examined as follows.

<Evaluation of Properties by Addition of Processing Aids>

[Examples 4 and 5]

The same procedure as in Example 3 was carried out, except that zinc-based surfactants and / or silanes were further added as processing aids. Components and contents of the blend according to the present embodiment are as shown in the following [Table 5]. And the mechanical properties of the specimen according to the present Example was evaluated in the same manner as in Example 3, and the results are shown in the following [Table 6].

[Comparative Example 6]

The same procedure as in Comparative Example 5 was carried out, except that zinc-based surfactant and silane were further added as processing aids. The components and contents of the blend according to the comparative example are as shown in [Table 5], and the results of the mechanical property evaluation are shown in the following [Table 6].

        <Component and content of silicone / natural rubber blend, unit: parts by weight> Remarks Example 3 Example 4 Example 5 Comparative Example 5 Comparative Example 6 SR (0.7) 50 50 50 - - SR (no vinyl) - - - 50 50 Natural Rubber (NR) 50 50 50 50 50 Silica 40 40 40 40 40 TESPD 0 0 5 0 5 Zinc-based surfactant
(Zinc-Surfactant) 0 3 3 0 3 Peroxide 2 2 2 2 2 Sulfur 2 2 2 2 2 ZnO 5 5 5 5 5 Stearic acid 2 2 2 2 2 TMTD 0.1 0.1 0.1 0.1 0.1 TBBS One One One One One Note 1) TESPD: Bis- (triethoxysilylpropyl) disulfide
Note 2) Zinc-based surfactant (Zinc-Surfactant): R = C ₁₂ in the formula
Note 3) Peroxide: 2,5-di-methyl-2,5-di-t-butyl peroxyhexane (gum)
Note 4) TMTD: Tetramethylthiuram disulfide
Note 5) TBBS: Nt-butyl-2-benzothiazolylsulfenamide

                 <Mechanical Property Evaluation Results> Remarks Example 3 Example 4 Example 5 Comparative Example 5 Comparative Example 6 The tensile strength
(Mpa) 6.9 6.4 5.3 1.8 2.3 Elongation
(%) 1233.6 697.1 554.8 592.1 264.2 Tensile modulus
300% (Mpa) 1.6 1.91 2 1.1 1.4 Hardness
(Shore A) 56.5 64.7 66.6 52.8 65.5 Bridge time
(min) 11 17.5 19 8.5 14

As shown in Table 6, when the zinc-based surfactant or silane (TESPD) is added as a processing aid, the elongation decreases but the modulus and hardness increase. Therefore, it can be seen that the physical properties can be adjusted by adding processing aids according to the use of the product. For example, a product (eg, dustproof rubber material, etc.) requiring tensile strength and elongation may be added without adding or adding a small amount of processing aid, and an appropriate amount may be added to a product requiring hardness, and the like, along with tensile strength and elongation. It was found that the hardness of the titration can be obtained.

1 to 3 are crosslinking characteristic curves of the silicone blend according to the experimental example of the present invention.

Figure 4 is a graph showing the hardness measurement results of the silicone blend according to the experimental example of the present invention.

5 is a SEM photograph of a silicone / natural rubber blend according to an embodiment of the present invention.

Claims (11)

Silicone rubber containing a vinyl group represented by the formula (2); Natural rubber represented by the following formula (3); Sulfur and peroxides as crosslinking agents; And At least one processing aid selected from the zinc-based surfactant represented by the formula (4) and the silane compound represented by the formula (5), The vinyl group is a silicone / natural rubber blend, characterized in that contained in a concentration of 0.02 to 0.75 mmol per 1 g of silicone rubber: [Formula 2]

In Formula 2, R ₁ is an alkyl group or a phenyl group, R ₂ and R ₃ is an alkyl group, a fluorinated alkyl group or a phenyl group, n and m is an integer of 1 or more; (3)

In Formula 3, n is an integer of 1 or more; [Formula 4]

In Chemical Formula 4, R is an alkyl group of C ₆ to C ₂₂ . [Chemical Formula 5]

delete delete delete delete delete delete delete delete Molded article comprising the silicone / natural rubber blend according to claim 1. The method of claim 10, The molded article is a molded article, characterized in that the dust-proof material.

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