KR101845825B1 - Crosslinking accelerator agent and composite of rubber for shortened crosslinking time using the same - Google Patents

Abstract

The present invention relates to a crosslinking accelerating additive and a butyl rubber composition having shortened crosslinking time using the same. More specifically, in order to shorten the crosslinking time of rubber having low unsaturation (e.g., butyl rubber), a crosslinking accelerating additive for accelerating crosslinking reaction of rubber is prepared. A design of a crosslinking system using the same (addition of a crosslinking accelerating agent and the addition of a crosslinking accelerating additive) not only reduces a defective product due to blooming but also significantly shortens the crosslinking time. In addition, when molding is performed at a high temperature in order to shorten the crosslinking time of a conventional rubber, energy consumption due to product molding is high, and as a result, there was a problem of manufacturing cost increase. The present invention relates to a rubber composition which can shorten the crosslinking time even at a molding temperature (150-160°C) of a general rubber.

Description

Technical Field [0001] The present invention relates to a crosslinking accelerating additive and a rubber composition using the crosslinking accelerating additive and shortening the crosslinking time by using the crosslinking accelerating additive.

The present invention relates to a crosslinking accelerating additive capable of shortening the slow crosslinking time of a rubber having a low unsaturation degree (double bond) and, in particular, reducing the defective rate of a product due to blooming, and a rubber having a short crosslinking time ≪ / RTI >

Generally, isobutene-isoprene rubber or butyl rubber is mostly a copolymer containing isobutene and a small amount of isoprene. On the other hand, unlike general rubber such as natural rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and butadiene rubber, butyl rubber is a highly saturated rubber having only a small amount of double bonds. This small amount of unsaturation (double bond) provides the site for vulcanization. Therefore, the butyl rubber can be classified into various products according to the unsaturation degree (the ratio of isoprene to isobutene) as described above. The butyl rubber with the highest degree of unsaturation has a higher vulcanization rate and a slightly lower ozone resistance than a rubber having a higher degree of saturation. To maximize ozone resistance, butyl rubber products with low unsaturation should be used. As the butyl rubber compound, carbon black, an inorganic filler, or both, a plasticizer, a processing aid, an antioxidant, an antiozonant, and a vulcanizing agent are usually used as a compounding agent. The vulcanizing agent is mainly used as a crosslinking agent, such as zinc oxide, a sulfur donor and sulfur system, a parachinone dioxime crosslinking agent activated by lead oxide, and a phenol resin activated by halogen-containing rubber or tin chloride. On the other hand, butyl rubber can not be crosslinked with organic peroxide because peroxide degrades the polymer. Sulfur vulcanization is widely used for most commonly used bridges.

However, as mentioned above, since the butyl rubber has a low unsaturation (double bond), the crosslinking speed during sulfur vulcanization is very slow compared to general purpose rubber. Such a low crosslinking reaction has a problem that the productivity of the product is lowered.

On the other hand, butyl rubber is generally incompatible with natural rubbers, styrene-butadiene rubbers, nitrile-butadiene rubbers, and highly unsaturated rubbers such as butadiene rubbers. Therefore, even if only a small amount of these rubbers are mixed, the butyl rubber reacts first with the vulcanizing agent, resulting in an unvulcanized state. That is, in order to shorten the crosslinking speed of the butyl rubber, the crosslinking speed seems to be shortened when blended with the rubber having high unsaturation, but in reality, the butyl rubber exists in an unreacted unvulcanized state.

Therefore, in a company producing butyl rubber products, as in Patent Document 1 or 2, crosslinking takes place at 155 ° C for 15 to 20 minutes (Patent Document 1) or at 155 to 160 ° C for 10 to 20 minutes (Patent Document 2) As described above, such a slow crosslinking rate lowers the productivity of the product. In Patent Document 3, in order to shorten the crosslinking rate of the slow butyl rubber, in the case of molding the product by increasing the molding temperature to 230 to 260 ° C in the crosslinking step However, when the molding temperature is increased, there is a problem that the energy consumption is high and the manufacturing cost is increased.

In order to solve this problem, the applicant of the present invention has previously filed a patent application entitled "Butyl Rubber Composition Shortened in Crosslinking Time" as in Patent Document 4. More specifically, Patent Document 4 discloses a crosslinking reaction of butyl rubber in a butyl rubber composition The use of 5 to 15 parts by weight of a crosslinking accelerator for accelerating the crosslinking accelerates not only shortens the crosslinking time and molding time but also shortens the crosslinking time even at the molding temperature of the general rubber.

However, in the case of Patent Document 4, there is a problem that blooming phenomenon often occurs on the rubber surface formed due to the use of excessive crosslinking accelerator. Here, the blooming phenomenon is a phenomenon that occurs due to migration of a solid or liquid compounding additive having a limited solubility in a polymer matrix, and a phenomenon in which a blend agent penetrates the rubber surface and a flower-like pattern is drawn It is defined as 'Bloom' as its derived title.

Patent Document 1: Korean Patent Laid-Open Publication No. 10-2003-0055754 entitled " Patent Document 2: Korean Patent Publication No. 10-1153916 "Butyl rubber composition improved in processability and moldability" Patent Document 3: Korean Patent Registration No. 10-1230058 entitled " Method for producing an aeruginous membrane having improved elasticity and durability, and a highly efficient aeruginous membrane prepared therefrom " Patent Document 4: Korean Patent Publication No. 10-1669479 entitled "Butyl Rubber Composition Shortened in Crosslinking Time"

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a crosslinking accelerating additive for promoting crosslinking reaction of rubber in order to shorten the crosslinking time of a rubber having low unsaturation (for example, It is aimed to not only reduce the defective product due to blooming but also to shorten the crosslinking time by designing the crosslinking system using the crosslinking agent (addition of weight loss and crosslinking promoting additive for crosslinking promoter).

On the other hand, when molding at a high temperature in order to shorten the crosslinking time of the conventional rubber, energy consumption due to product molding is high, resulting in a problem of increase in manufacturing cost. However, ), The crosslinking time is shortened.

The present invention provides a crosslinking promoting additive characterized by coating a surface of a porous inorganic material with a latex having a double bond in a crosslinking promoting additive.

More specifically, it is preferable that the crosslinking promoting additive is coated by mixing 10 to 200 parts by weight of a latex having a double bond with respect to 100 parts by weight of the porous inorganic material.

On the other hand, the double bond latex may be a natural rubber latex, a butadiene rubber latex, a styrene butadiene rubber latex or an acrylonitrile-butadiene rubber latex. latex), but the present invention is not limited thereto, and it is possible to apply latex groups having already known various double bonds.

The porous inorganic material may be used alone or in combination of two or more of silica, zeolite, bentonite, activated carbon, alumina or fly ash, but the present invention is not limited thereto. pore) are formed, either naturally occurring or artificially produced.

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On the other hand, the present invention provides a rubber composition having a shortened crosslinking time, which comprises the above-mentioned crosslinking promoting additive, as another solution to the problem.

More specifically, the rubber composition preferably comprises 0.5 to 20 parts by weight of a crosslinking promoting additive and a crosslinking accelerator based on 100 parts by weight of the rubber.

The crosslinking accelerator may be at least one selected from the group consisting of acidic ethylenedi dithiocarbamate (ZDEDC), zinc dienbutyl dithiocarbamate (ZDBDC), zinc ethylphenyl dithiocarbamate (ZEPDC) or zinc dimethyldithiocarbamate (ZDMDC ). However, the present invention is not limited thereto, and various known crosslinking accelerators can be applied.

The present invention relates to a crosslinking promoting additive for promoting crosslinking reaction of rubber in order to shorten the crosslinking time of a rubber having low unsaturation (for example, butyl rubber, etc.), and to provide a crosslinking system design Addition of a crosslinking accelerating additive) not only reduces the defective rate of product due to blooming but also has an effect of extremely shortening the crosslinking time.

On the other hand, when molding at a high temperature in order to shorten the crosslinking time of the conventional rubber, energy consumption due to product molding is high, resulting in a problem of increase in manufacturing cost. However, ), The crosslinking time can be shortened.

That is, the present invention reduces the defect rate of the product due to blooming and shortens the crosslinking time more than the conventional technique, thereby increasing the productivity and efficiency, thereby lowering the manufacturing cost and increasing the price competitiveness.

Brief Description of Drawings Fig. 1 is a photograph showing a blooming state of an embodiment and a comparative example according to the present invention

The crosslinking promoting additive for achieving the above effect and the butyl rubber composition having a shortened crosslinking time by using the same are described only for the purpose of understanding the technical composition of the present invention, It will be omitted so as not to disturb the gist of the present invention.

Hereinafter, the crosslinking promoting additive according to the present invention and the butyl rubber composition having a shortened crosslinking time using the same will be described in detail as follows.

First, the crosslinking promoting additive according to the present invention is characterized in that latex having a double bond is coated on the surface of the porous inorganic material. That is, by using the crosslinking promoting additive as described above, it is possible to reduce the amount of the crosslinking accelerator to be described later, thereby reducing the defective rate of the product due to blooming and also providing a very excellent crosslinking time shortening effect.

Here, the latex having a double bond also includes a conventional solution in which a latex having a double bond is dissolved.

More specifically, the crosslinking promoting additive is prepared by mixing 10 to 200 parts by weight of a latex having a double bond with 100 parts by weight of the porous inorganic material.

If the content of the latex is less than 10 parts by weight, the effect of shortening the crosslinking time may be insufficient. If the content of the latex is more than 200 parts by weight, the latex may be agglomerated and peeled off from the porous inorganic material.

On the other hand, the double bond latex may be a natural rubber latex, a butadiene rubber latex, a styrene butadiene rubber latex or an acrylonitrile-butadiene rubber latex. latex), but the present invention is not limited thereto, and it is possible to apply latex groups having already known various double bonds.

The porous inorganic material may be used alone or in combination of two or more of silica, zeolite, bentonite, activated carbon, alumina or fly ash. However, the porous inorganic material is not limited thereto and may be fine particles having a diameter of several nm to several 탆 pore) are formed, either naturally occurring or artificially produced.

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Next, the rubber composition having shortened crosslinking time according to the present invention comprises the above-mentioned crosslinking promoting additive, and more specifically, it is preferable that 0.5 to 20 parts by weight of the crosslinking promoting additive, And 1 to 3 parts by weight of an accelerator.

The rubber used in the present invention may be a rubber having a low degree of unsaturation (double bond). For example, butyl rubber may be used. On the other hand, the butyl rubber can be used alone or in combination of butyl rubber (IIR), bromobutyl rubber (BIIR) and chlorinated butyl rubber (CIIR).

The crosslinking promoting additive used in the present invention has already been described in detail, and a detailed description thereof will be omitted. On the other hand, when the content of the crosslinking promoting additive is less than 0.5 part by weight in forming the rubber composition, there is a possibility that the effect of shortening the crosslinking time is insufficient. When the content is more than 20 parts by weight, the vulcanization of the butyl rubber is prevented, There is a problem that the mechanical strength is lowered.

The crosslinking accelerator used in the present invention is added in order to promote the function of the crosslinking agent. The crosslinking accelerator is selected from the group consisting of acid chloride type zincdiethyldithiocarbamate (ZDEDC), zinc dienbutyldithiocarbamate (ZDBDC), zinc ethylphenyldithiocarbamate Mate (ZEPDC) or zinc dimethyldithiocarbamate (ZDMDC).

If the amount of the crosslinking accelerator is less than 1 part by weight, the effect of shortening the crosslinking time is insufficient. If the amount of the crosslinking accelerator is more than 3 parts by weight, the product may be defective due to the blooming phenomenon.

In the present invention, as an additive commonly used in rubber compositions, 2 to 5 parts by weight of zinc oxide, 0.5 to 1.5 parts by weight of stearic acid, 0.1 to 0.3 parts by weight of an antioxidant, 10 to 60 parts by weight of silica, 0.5 to 4 parts by weight of polyethylene glycol 5 to 15 parts by weight of a silicone rubber and 1.0 to 1.5 parts by weight of a crosslinking agent are usually used in a rubber composition and a description of its function and critical significance is omitted. Can be variable. In addition to the above additives, various known additives may be used in consideration of the application field of the composition, the environment, and the like.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited by the following examples.

1. Preparation of crosslinking promoting additive

(Production Example 1)

Add silica (Zeosil 155, Rhodia) to a Super Mixer (20 L), adjust the stirring speed to about 200 rpm, and slowly add natural rubber latex for 1 minute (75 parts by weight of latex to 100 parts of silica). The mixture was stirred at about 800 rpm for 15 minutes, dumped, and dried in an oven at 60 ° C. until the moisture content was within 5%.

(Production Example 2)

Silica (Zeosil 155, Rhodia) is added to a Super Mixer (20 L), the stirring speed is set to about 200 rpm, and a styrene-butadiene rubber latex is slowly added for 1 minute (200 parts by weight of latex is added per 100 parts by weight of silica ). The mixture was stirred at about 800 rpm for 15 minutes, dumped, and dried in an oven at 60 ° C. until the moisture content was within 5%.

(Production Example 3)

Silica (Zeosil 155, Rhodia) is added to a Super Mixer (20 L) and the acrylonitrile butadiene rubber latex is slowly added for 1 minute while adjusting the stirring speed to about 200 rpm (75 parts by weight of latex, input). The mixture was stirred at about 800 rpm for 15 minutes, dumped, and dried in an oven at 60 ° C. until the moisture content was within 5%.

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2. Preparation of rubber composition

(Example 1)

5 parts by weight of zinc oxide, 1 part by weight of stearic acid, 0.2 part by weight of antioxidant, 45 parts by weight of silica, 3 parts by weight of polyethylene glycol and 10 parts by weight of silicone rubber were added to 100 parts by weight of butyl rubber in a kneader After mixing for 12 minutes, 0.5 part by weight of the crosslinking promoting additive according to Preparation Example 1, 2.0 parts by weight of the crosslinking accelerator and 1.2 parts by weight of the crosslinking agent according to Production Example 1 were put in an open roll mill and uniformly mixed. The t90 was measured with a curistometer, (The mixing ratio is as shown in Table 1 below).

(Example 2)

5 parts by weight of zinc oxide, 1 part by weight of stearic acid, 0.2 part by weight of antioxidant, 45 parts by weight of silica, 3 parts by weight of polyethylene glycol and 10 parts by weight of silicone rubber were added to 100 parts by weight of butyl rubber in a kneader After mixing for 12 minutes, 2.5 parts by weight of the crosslinking accelerating additive according to Production Example 2, 2.0 parts by weight of the crosslinking accelerator and 1.2 parts by weight of the crosslinking agent according to Production Example 2 were added in an open roll mill, uniformly mixed and measured for t90 with a currustometer. (The mixing ratio is as shown in Table 1 below).

(Example 3)

5 parts by weight of zinc oxide, 1 part by weight of stearic acid, 0.2 part by weight of antioxidant, 45 parts by weight of silica, 3 parts by weight of polyethylene glycol and 10 parts by weight of silicone rubber were added to 100 parts by weight of butyl rubber in a kneader After mixing for 12 minutes, 7.5 parts by weight of the crosslinking promoting additive according to Production Example 3, 2.0 parts by weight of the crosslinking accelerator, and 1.2 parts by weight of the crosslinking agent according to Production Example 3 were added in an open roll mill and mixed uniformly. The t90 was measured with a curistometer, (The mixing ratio is as shown in Table 1 below).

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(Comparative Example 1)

5 parts by weight of zinc oxide, 1 part by weight of stearic acid, 0.2 part by weight of antioxidant, 45 parts by weight of silica, 3 parts by weight of polyethylene glycol and 10 parts by weight of silicone rubber were added to 100 parts by weight of butyl rubber in a kneader After mixing for 12 minutes, 3.0 parts by weight of a crosslinking accelerator and 1.2 parts by weight of a crosslinking agent were added in an open roll mill, uniformly mixed, and measured for t90 by a currutometer, followed by molding into a press (Table 1 below) .

2. Characterization

The properties of the rubber compositions prepared in Examples 1 to 4 and Comparative Example 1 were evaluated according to the following test methods.

1) Crosslinking time: Measured using a curastometer.

2) Minimum torque / maximum torque: The minimum torque (ML) and the maximum torque (MH) were measured using a torque rheometer, and the difference between the maximum torque and the minimum torque (DELTA torque) was measured.

3) Tensile strength: Measured using the KSM 6518 method.

4) Elongation Ratio: Measured using the KSM 6518 method.

5) Blooming: Judged whether the blooming of the molded product was visually observed.

The compositions and evaluation results of the above Examples and Comparative Examples are summarized in Table 1 below.

division Comparative Example Example 1 Example 2 Example 3
Butyl rubber ^{Note 1)} 100 100 100 100 Zinc oxide ^{Note 2)} 5 5 5 5 Stearic acid ^{Note 3)} One One One One Antioxidants ^{Note 4)} 0.2 0.2 0.2 0.2 Silica ⁵⁾ 45 45 45 45 Polyethylene glycol ^{Note 6)} 3 3 3 3 Silicone rubber ^{Note 7)} 10 10 10 10
According to Preparation Example 1
Crosslinking accelerating additive - 0.5 - - According to Production Example 2
Crosslinking accelerating additive - - 2.5 - According to Preparation Example 3
Crosslinking accelerating additive - - - 7.5 According to Production Example 4
Crosslinking accelerating additive - - - - Cross-linking accelerator ^{Note 8)} 3.0 2.0 2.0 2.0 Cross-linking agent ^{Note 9)} 1.2 1.2 1.2 1.2 Bridging time
(t90 @ 150 DEG C) min 9 minutes 19 seconds 5 minutes 21 seconds 4 minutes 05 seconds 4 minutes 40 seconds ML / MH dNm 0.496 / 0.845 0.842 /
1.482 0.94 /
1.771 0.851 /
1.524 Δ torque dNm 0.349 0.64 0.831 0.673 The tensile strength kg / cm ² 113 148 151 145 Elongation rate % 750 850 800 820 Blooming
(See Fig. 1) U radish radish radish Note 1) ExxonMobil, BIIR 2244
Note 2) PJ Chemtech, Zinc oxide (rubber type 1)
Note 3) LG Chem, stearic acid
Note 4) Uni Royal Chemicals, BHT
Note 5) Rhodia, Zeosil 155
Note 6) Green chemical, PEG4000
Note 7) Dow Corning, CF201U
Note 8) Samwon Chem, EZ
Note 9) Miwon Chemical, sulfur

As shown in [Table 1] and FIG. 1 below, it can be seen that the embodiment according to the present invention can reduce the defect rate due to blooming, while shortening the crosslinking time, in comparison with the comparative example.

As described above, the crosslinking promoting additive according to the present invention and the butyl rubber composition having a shortened crosslinking time using the same are explained through the above-mentioned preferred embodiments, and the superiority is confirmed. However, those skilled in the art It will be understood that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (8)

In the crosslinking promoting additive,
10 to 200 parts by weight of a latex having a double bond is mixed and coated on 100 parts by weight of the porous inorganic material,
The double bond latex may be selected from the group consisting of natural rubber latex, butadiene rubber latex, styrene butadiene rubber latex or acrylonitrile-butadiene rubber latex. Which are used singly or in combination,
Wherein the porous inorganic material is used in combination of silica, zeolite, bentonite, activated carbon, alumina or fly ash, or a combination of two or more thereof.
delete delete delete delete A rubber composition comprising a crosslinking accelerating additive and shortened crosslinking time,
0.5 to 20 parts by weight of a crosslinking promoting additive, and a crosslinking accelerator, based on 100 parts by weight of the rubber,
The crosslinking promoting additive is prepared by mixing and coating 10 to 200 parts by weight of a latex having a double bond with respect to 100 parts by weight of a porous inorganic material. The latex having the double bond may be a natural rubber latex, a butadiene rubber latex butadiene rubber latex or styrene butadiene rubber latex or acrylonitrile-butadiene rubber latex. The porous inorganic material may be selected from the group consisting of silica, zeolite, bentonite, activated carbon , Alumina or fly ash, or a combination of two or more thereof,
The cross-linking accelerator may be selected from the group consisting of acidic zinc cetyl ethyl dithiocarbamate (ZDEDC), zinc dienbutyl dithiocarbamate (ZDBDC), zinc ethylphenyl dithiocarbamate (ZEPDC) or zinc dimethyldithiocarbamate (ZDMDC) Wherein the crosslinking time is shortened.
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