KR20040098913A - Silica master-batch and its preparing method - Google Patents

Abstract

PURPOSE: A silica masterbatch is provided, which contains silica in large quantities by increasing compatibility of the silica and a base rubber by controlling contents of additives and a mixing condition specially. And a process for producing the silica masterbatch is also provided. CONSTITUTION: The silica masterbatch is produced by the process containing the steps of: pre-mixing a rubber, a thermoplastic resin, or a mixture thereof as a base material at 130-170deg.C; injecting 150-200pts.wt. of the silica, 7-20pts.wt. of a silane-based coupling agent, 15-50pts.wt. of a processing oil, and 7-20pts.wt. of an activator into 100pts.wt. of the base material and mixing; making sheets of the mixture and compressing. The rubber is selected from a natural rubber(NR), a butadiene rubber(BR), a styrene-butadiene rubber(SBR), a modified styrene-butadiene rubber(SBR), an ethylene-propylene rubber(EPM, EPDM), and a nitrile rubber(NBR). And the thermoplastic resin is selected from a polyethylene(PE), an ethylene vinyl acetate copolymer(EVA), an ethylene butene copolymer, and etc.

Description

Silica master batch and its preparing method

The present invention relates to a silica master batch and a method for preparing the same, and more particularly, to preparing a master batch containing rubber as a substrate, a thermoplastic resin or a mixture thereof and containing silica as a filler. Silica masterbatch and its composition that can contain a large amount of silica by increasing the compatibility of the substrate mixture and silica by specifically adding a limited amount of silane coupling agent, processing oil and activator to the substrate mixture and controlling the kneading conditions It relates to a manufacturing method.

The rubber industry considers workers to be reluctant to work because there are a lot of additives scattered and the working environment is extremely poor. Therefore, it is currently difficult to find workers in Korea, so foreign workers are employed. In developed countries, rubber and additives are mixed and manufactured in a masterbatch form in order to solve the poor problem of the work environment caused by such scattering additives. Accordingly, it solves the problem of the work environment caused by the scattering of additives, thereby protecting the human rights of workers to some extent, and further, the industry for manufacturing the master batch as described above is activated, contributing to the development of the rubber industry. In the mid-1990s, rubber additives were also manufactured and used in the master batch form in Korea.

As such, rubber master batches manufactured in developed countries or domestically are mainly used to improve the working environment, but rubber manufacturers using them are just as important as economic improvement. Therefore, the master batch used in the rubber manufacturing industry should contain at least 100 parts by weight of the additive in 100 parts by weight of the base material to easily control the amount and physical properties of the additives in the rubber product manufactured using the same, and to minimize the increase in the price of the product. Currently commercially available masterbatch is somewhat different depending on the additive, but generally 100 to 250 parts by weight of the additive is used that contains about 100 to 250 parts by weight.

In the case of producing silica in a master batch, until now, it is a limitation to include 50 to 70 parts by weight of silica in 100 parts by weight of rubber. In this case, workability is poor, and thus a large amount of silane coupling agent or processing oil needs to be used. In addition, the silica masterbatch prepared as described above is less economical to less than 70 parts by weight of silica with respect to 100 parts by weight of the base material, manufacturers are avoiding such a silica masterbatch, and the rubber content is also low due to low silica content in rubber companies Because of this situation is reluctant to use. Above all, masterbatch manufacturers have no technology to increase silica content because it is a simple technology manufactured using a mixer (kneader, rubber extruder, etc.).

As such, in the rubber industry, additives that have been scattered have been manufactured and used as master batches, but silicas used as fillers cannot be used in high concentration (content) master batches, but are still used as powders or granules rather than master batches. Therefore, it is impossible to improve the working environment in the field using silica. Therefore, when using silica, workers should wear dustproof clothes and masks, which are less breathable, and suffer from various inconveniences such as a lot of sweating, and it is urgent to develop a silica masterbatch that can improve this. .

Accordingly, the present inventors have made efforts to solve the above problems, and in order to develop a silica masterbatch having a high silica content, the present inventors have studied the surface properties of silica and the processing oil and the silane coupling agent. As a result of specifically limiting the content thereof and adding the mixture, the kneading conditions were specifically controlled. As a result, it was found that a silica masterbatch containing at least 150 parts by weight of silica could be prepared based on 100 parts by weight of the substrate. .

Therefore, the present invention improves the poor working environment caused by fugitive dust when using powdered or granular silica in the rubber industry, and includes silica containing a large amount of silica which can fundamentally solve waste or loss due to poor dispersion of silica. The purpose is to provide a masterbatch and a method of manufacturing the same.

1 is a photograph showing dust characteristics according to the case of using the silica powder (a) and the case of using the silica masterbatch of the present invention (b).

Figure 2 is a photograph comparing the appearance of the silica powder (a) and the silica masterbatch (b) of the present invention.

The present invention uses a rubber, a thermoplastic resin, and a mixture thereof as a substrate, and 150 to 200 parts by weight of silica, 7 to 20 parts by weight of the silane coupling agent, 15 to 50 parts by weight of the processing oil and the activator, based on 100 parts by weight of the substrate. It is characterized by a silica masterbatch comprising 7 to 20 parts by weight.

In addition, the present invention is a process of pre-kneading a rubber, a thermoplastic resin or a mixture thereof at 130 to 170 ℃ as a substrate, 150 to 200 parts by weight of silica, 7 to 20 parts by weight of the silane coupling agent, processing oil relative to 100 parts by weight of the substrate 15 to 50 parts by weight and 7 to 20 parts by weight of the activator is added to kneading, and the method for producing a silica masterbatch comprising the step of preparing the kneaded product in a sheet form and then compressing to produce a desired shape. .

The present invention will be described in detail as follows.

The present invention relates to a silica master-batch and a method for preparing the same, and more particularly, to preparing a masterbatch using rubber, a thermoplastic resin or a mixture thereof as a substrate and containing silica as a filler. Silica masterbatch and its preparation to include a large amount of silica by increasing the compatibility of the base mixture and silica by specifically adding a limited amount of silane coupling agent, processing oil and activator to the mixture and adjusting the kneading conditions It is about a method.

Silica used as a filler in the rubber industry has been poorly compatible with rubber used as a base material, and has been used in the rubber industry as a powder or granule, and thus the working environment is poor due to dust scattered during processing ( 1 (a)), and also causes problems such as occupational diseases such as pneumoconiosis.

These silicas are classified into dry silica and wet silica, depending on their preparation. First, dry silica is widely used in transparent products, and since the particle size is nano-level and the apparent specific gravity is 0.2 or less, it appears that there is a heavy fog around the processing equipment during the operation because dry silica is scattered in large quantities. When the amount of dry silica is more than 100 parts by weight based on 100 parts by weight of the base rubber, even if the amount of processing oil used for the purpose of improving the processability of the base rubber and the silica is 50 parts by weight or more, the produced masterbatch becomes hard as stone. When the processing becomes impossible and the amount of dry silica is 50 parts by weight or less, it is possible to manufacture the masterbatch itself without using the processing oil, but the economical efficiency is low because the content of the silica contained in the masterbatch is small. Therefore, the master batch for dry silica can be produced only when the silica content is low, and therefore, it is suitable for rubber compounding having a dry silica content of about 50 parts by weight.

Wet silica, on the other hand, is micrometer-sized, supplied in powder or granular form, and poorly compatible with rubber, resulting in long working hours as well as misting around processing equipment (kneaders, short-barrier mixers, etc.). Scattered. When using about 7.5 parts by weight of the silane coupling agent, 10 parts by weight of the activator, and 20 parts by weight of the processing oil based on 100 parts by weight of the base rubber, it is possible to easily prepare a masterbatch including up to 150 parts by weight of the above-mentioned wet silica. To increase the amount of wet silica to include 250 parts by weight, at least 30 parts by weight of the silane coupling agent, 25 parts by weight of the activator and 50 parts by weight of the processing oil should be used. When manufactured, there is a problem in that the economy is excellent but the physical properties of the product compared to the silica content. At this time, when the amount of processing oil is reduced in consideration of physical properties and exceeds 250 parts by weight of silica, the appearance is changed into a powder form, it is impossible to produce a master batch.

Accordingly, in the present invention, rubber, thermoplastic resins or mixtures thereof are used as the base material, and the amount of the additive is limited to a specific content ratio, and by adjusting the conditions when kneading them, the amount of the base and the silica is not excessively used. The miscibility of was increased to prepare a masterbatch containing excess silica.

The silica masterbatch of the present invention uses rubber, thermoplastic resins or mixtures thereof as the substrate.

The rubber is selected from natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), modified styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM, EPDM) and nitrile rubber (NBR). One kind or a mixture of two or more kinds may be used, and as the thermoplastic resin, polyethylene (PE), ethylene vinyl acetate copolymer (EVA), ethylene butene copolymer, ethylene octene copolymer, styrene-isoprene-styrene copolymer (SIS), One or a mixture of two or more selected from styrene-butadiene-styrene copolymer (SBS) and 1,2-polybutadiene (1,2-PB) is used. The base material is determined by the company required and the formulation used. However, when the butadiene rubber (BR) is used as a substrate in the rubber, when the amount of silica exceeds 150 parts by weight based on 100 parts by weight of the base, a desired master batch of about 20 parts by weight or more must be added to the amount of processing oil applied when using other rubber. Can be prepared.

In the present invention, a silane coupling agent usually used in the rubber industry is used in order to increase the compatibility between rubber as a base material and silica as a filler, and specifically, for example, vinyl trichlorosilane and vinyl tri (2-methoxy). Vinyl silanes such as methoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Glycidyloxypropylmethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-amino Propyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-metlabtopfiltrimethoxysilane, 3-chloropropyltrimethoxysilane, bis (triethoxysilpropyl) tetrasulfane [Bis (triethoxysilypropyl) tetrasulfane] and thiocyanatopropyltriethoxysilane (Thioc) yanatopropyltriethoxysilane) may be used one or two or more selected from. The silane coupling agent is used in an amount of 7 to 20 parts by weight based on 100 parts by weight of the substrate, and when the amount of the silane coupling agent is less than 7 parts by weight, the compatibility of the rubber used as the substrate is low and the silica is improved. When it is difficult and used in excess of 20 parts by weight, there is no problem of improving the compatibility according to the increase of the silane coupling agent, the price of the master batch is increased, and there is a problem of discoloration and odor of the silane coupling agent in the master batch.

Processing oils, which are processing aids, are paraffinic, naphthenic and aromatic. If the rubber formulation to be applied is irrelevant to color, it is appropriate to use naphthenic and aromatic oils. On the other hand, when the rubber mixture using the silica master batch is colored, it is preferable to use a paraffin-based processing oil. Such processing oil is used 15 to 50 parts by weight based on 100 parts by weight of the base material, if the amount used is less than 15 parts by weight, the role of the processing aid is difficult to produce a master batch, when used in excess of 50 parts by weight of the processability Improved masterbatch is easily produced, but there is a problem in that the physical properties of the rubber compound using it is significantly reduced.

As the activating agent, one or a mixture of two or more selected from diethylene glycol, polyethylene glycol, PE wax, high boiling alcohols, etc. may be used, and the amount of the activator is 7 to 20 parts by weight based on 100 parts by weight of the substrate. At this time, if the amount of the activator is less than 7 parts by weight, when using the silica masterbatch, there is a problem that a new addition must be added in the compounding. There is a problem of declining commodity value.

By limiting the amount of the additive used as described above, it is possible to manufacture a masterbatch containing a large amount of silica intended in the present invention, wherein the silica is included 150 to 200 parts by weight based on 100 parts by weight of the substrate It will contain 200-290% more silica than the silica masterbatch. As the silica used in the present invention, both dry silica or wet silica can be used.

Silica masterbatch of the present invention consisting of the above components was prepared in a controlled manner as follows it was possible to manufacture a masterbatch containing a large amount of silica.

First, rubber, a thermoplastic resin, or a mixture thereof is preliminarily kneaded as a base material. In this case, a kneader or a short-barrier mixer is used as the mixer, and the substrate is kneaded for about 3 to 5 minutes to improve compatibility with the additives added next.

Next, 150 to 200 parts by weight of silica, 7 to 20 parts by weight of the silane coupling agent, 15 to 20 parts by weight of the processing oil and 7 to 20 parts by weight of the activator are kneaded with respect to 100 parts by weight of the base mixture. The kneading temperature is adjusted to 130 to 170 ° C., and the kneading time is about 15 to 25 minutes. At this time, as in the preliminary kneading, when the kneading temperature is less than 130 ° C., there is no significant difference in terms of compatibility between the substrate and silica, and when it exceeds 170 ° C., the thermal aging of the rubber proceeds rather than the effect of improving the compatibility of the rubber and silica. There is a problem of discoloration of the masterbatch. The kneaded product prepared under the above temperature conditions may be prepared in a master batch into a desired shape such as sheet shape, pellet shape or lump shape. For example, the pellet may be manufactured through an extruder after producing the sheet in an open roll mill. Alternatively, the sheet may be manufactured using an open roll mill and a calendar, or may be manufactured in a lump form through a compressor after the open roll mill processing.

The silica masterbatch of the present invention prepared as described above is easier to mix and process the rubber than the conventional powder or particulate silica, and silica dust is reduced to facilitate the quality control of rubber products, As fugitive dust of silica disappears, the working environment can be kept clean, which is effective for improving worker's health and working environment.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

Example 1 Silica 200 parts by weight Masterbatch

100 parts by weight of modified styrene-butadiene rubber (SBR) was kneaded in advance at 130 to 140 ° C. for 5 minutes, followed by 200 parts by weight of silica, 20 parts by weight of bis (triethoxysiripropyl) tetrasulfane, a silane coupling agent, 40 parts by weight of paraffin-based processing oil and 15 parts by weight of diethylene glycol were added thereto, followed by kneading for 25 minutes to prepare a sheet in an open roll mill at 80 ° C.

Example 2 200 parts by weight of the masterbatch

100 parts by weight of styrene-butadiene-styrene copolymer (SBS) was kneaded in advance for 5 minutes at 130 to 150 ° C. kneader, and 200 parts by weight of silica and bis (triethoxysiripropyl) tetrasulfane 20 as a silane coupling agent were added. By weight, 40 parts by weight of paraffin-based processing oil and 15 parts by weight of polyethylene glycol were added and kneaded in a kneader for 25 minutes, a silica master batch was prepared in the form of a sheet using an open roll mill and a calendar at 80 ° C.

Example 3 150 parts by weight of masterbatch silica

A mixture of 50 parts by weight of styrene-butadiene rubber (SBR) and 50 parts by weight of natural rubber is kneaded in advance at 130 to 150 ° C. for 4 minutes by adding 150 parts by weight of silica and bis (triethoxysilpropyl as a silane coupling agent). 10 parts by weight of tetrasulfane, 25 parts by weight of paraffin-based processing oil and 10 parts by weight of diethylene glycol were added and kneaded for 20 minutes to prepare a masterbatch in a lump form using a pressurizer.

Example 4 150 parts by weight of masterbatch

A mixture of 50 parts by weight of styrene-butadiene-styrene copolymer (SBS) and 50 parts by weight of natural rubber is kneaded in advance at 130 to 150 ° C. for 5 minutes, and there are 150 parts by weight of silica and a bis (trie) silane coupling agent. 10 parts by weight of oxysilpropyl) tetrasulfane, 25 parts by weight of paraffin-based processing oil, and 10 parts by weight of polyethylene glycol were added and kneaded in a kneader for 20 minutes, followed by a silica master batch in a sheet shape using an open roll mill and a calendar at 80 ° C. Prepared.

Comparative Example 1

100 parts by weight of styrene-butadiene rubber (SBR) was pre-kneaded in a 100 ° C kneader for 5 minutes, and 150 parts by weight of silica was kneaded for 30 minutes in a kneader, followed by a master batch of silica in a sheet shape using an open roll mill and a calendar at 80 ° C. Attempted to produce a powder form was not possible to produce a master batch.

Comparative Example 2

100 parts by weight of styrene-butadiene-styrene copolymer (SBS) was pre-kneaded in a 100 ° C kneader for 5 minutes, 150 parts by weight of silica and 40 parts by weight of paraffin-based processing oil were added thereto, followed by kneading for 20 minutes in a kneader, followed by 80 ° C An attempt was made to prepare a silica masterbatch in the form of a sheet using an open roll mill and a calendar, but it was impossible to prepare the masterbatch due to the powder form.

Comparative Example 3

100 parts by weight of natural rubber (NR) was pre-kneaded in a 100 ° C kneader for 5 minutes, and 150 parts by weight of silica, 40 parts by weight of paraffin-based processing oil, and 15 parts by weight of diethylene glycol were kneaded in a kneader for 20 minutes, and then pressurized. Attempted to prepare a master batch in the form of agglomerate, but it was impossible to produce a master batch in the form of a powder.

Each of the composition components and master batch production results used in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1 below.

Example 5

50 parts by weight of polybutadiene rubber having a cis-1,4-butadiene content of 96 mol%, 10 parts by weight of natural rubber, 10 parts by weight of styrene-butadiene rubber (SBR) and 88.5 weight of the silica masterbatch prepared in Example 3 (Composition: 15 parts by weight of natural rubber, 15 parts by weight of styrene-butadiene rubber (SBR), 45 parts by weight of silica, 3 parts by weight of silane coupling agent, 3 parts by weight of polyethylene glycol 7.5 parts by weight of processed oil), metal oxide masterbatch 6.5 1 part by weight, 1 part by weight of stearic acid, 3 parts by weight of an anti-aging agent, and knead for 10 minutes in advance at 80 to 120 ℃ kneader, 0.25 parts by weight of a thiazole vulcanization accelerator masterbatch, 2 parts by weight of a thiazole vulcanization accelerator masterbatch, 0.065 parts by weight of a thiuram vulcanization accelerator masterbatch was added and kneaded in a kneader at 90 ° C. for 5 minutes, followed by kneading for 5 minutes by adding 3 parts by weight of a sulfur masterbatch at an open roll mill at 70 ° C. St. components, see the following table 2). This was pressed for 5 minutes at 150 ℃, 150 ton press to prepare a shoe outsole, the physical properties were evaluated by the following test method and the results are shown in Table 3 below.

Comparative Example 4

A substrate consisting of 50 parts by weight of polybutadiene rubber having a cis-1,4-butadiene content of 96 mol%, 25 parts by weight of natural rubber, and 25 parts by weight of styrene-butadiene rubber (SBR) in a 80 to 120 ° C kneader for 5 minutes in advance Kneaded in advance, 45 parts by weight of silica, 4.5 parts by weight of bis (triethoxysiripropyl) tetrasulfane, a silane coupling agent, 4 parts by weight of polyethylene glycol, 6.5 parts by weight of a metal oxide masterbatch, 1 part by weight of stearic acid, 3 parts by weight of antioxidant was added and kneaded in a kneader at around 120 ° C. for 15 minutes, followed by 0.25 parts by weight of a thiazole vulcanization accelerator, 2 parts by weight of a thiazole vulcanization accelerator, and 0.065 of a thiuram vulcanization accelerator. After adding 5 parts by weight and kneading for 5 minutes in a 90 ℃ kneader, and then kneading for 5 minutes by adding 3 parts by weight of a sulfur masterbatch in an open roll mill at 70 ℃ ( Reference 2). This was pressed for 5 minutes at 150 ℃, 150 ton press to prepare a shoe outsole, the physical properties were evaluated by the following test method and the results are shown in Table 3 below.

<Test method>

The characteristics of the shoe outsole manufactured by Example 5 and Comparative Example 4 were measured in the following manner.

Hardness: It was measured using the method of KS M 6518.

Specific gravity: It was measured using an automatic specific gravity measurement device (model DMA-3) by the method of KS M 6519.

Tensile strength was measured using the method of KS M 6518.

-M300: Measured using the method of KS M 6518.

Elongation rate was measured using the method of KS M 6518.

Tear strength: measured using the method of KS M 6518.

-NBS: NBS (ASTM 1630) was used to measure the wear resistance was calculated by the following equation, the measurement method was based on KS M6625.

DIN wear: measured by DIN 53616 to measure wear resistance.

-Akron abrasion: Acron was used to measure wear resistance. Abrasion index was shown as weight loss by performing 300 times with 6 pound load and then 3000 times with 6 pound load.

As shown in Table 1, in Examples 1 to 4, silica master batches containing 150 to 200 parts by weight of silica could be prepared, whereas in Comparative Examples 1 to 3, silica master batches could not be prepared. Figure 2 compares the appearance of the silica and the masterbatch can not only predict the degree of scattering of silica in the kneader or banbari mixer process when mixing the rubber, in Example 5 and Comparative Example 4, respectively, the silica masterbatch and powder silica By using it, you can see how clean the surroundings of the device can be in the kneader process.

In the case of using a silica masterbatch, it was confirmed that not only increased productivity by reducing the work time by 33%, but also exhibited excellent physical properties as shown in Table 3 above.

As described above, according to the present invention, by specifically adjusting the content of the additive and the kneading conditions, it is possible to prepare a silica masterbatch containing a high content of silica by improving the compatibility between the silica and the base rubber and thus scattering silica. This can improve the poor working environment and increase the economics.

In addition, by using a silica masterbatch, not only improves productivity by reducing the work time by 33% than conventional powder or granular silica, but also disperses the silica easily, thereby providing a rubber product having the same silica content. In comparison, there is an effect of showing better physical properties.

Claims (6)

A rubber, a thermoplastic resin, or a mixture thereof is used as the substrate, and 150 to 200 parts by weight of silica, 7 to 20 parts by weight of the silane coupling agent, 15 to 50 parts by weight of the processing oil, and 7 to 7 parts by weight of 100 parts by weight of the substrate mixture. Silica masterbatch characterized in that it comprises 20 parts by weight. The method of claim 1, wherein the base material is rubber, natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), modified styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM, EPDM) and Nitrile rubber (NBR), polyethylene (PE), ethylene vinyl acetate copolymer (EVA), ethylene butene copolymer, ethylene octene copolymer, styrene-isoprene-styrene copolymer (SIS), styrene-butadiene-styrene as thermoplastic resin Silica masterbatch, characterized in that one or a mixture of two or more selected from copolymers (SBS) and 1,2-polybutadiene (1,2-PB). The said silane coupling agent is vinyl silane, such as vinyl trichlorosilane, a vinyl tri (2-methoxyethoxy) silane, a vinyl triethoxy silane, and a vinyl trimethoxysilane, and 3-methacryl. Roxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropyltri Methoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-methaptopfil 1 or 2 selected from trimethoxysilane, 3-chloropropyltrimethoxysilane, bis (triethoxysilypropyl) tetrasulfane and Thiocyanatopropyltriethoxysilane Silica masterbatch, characterized in that the mixture of more than one species. The silica master batch according to claim 1, wherein the activating agent is one or a mixture of two or more selected from diethylene glycol, polyethylene glycol, piwax, and high boiling alcohols. A process of preliminarily kneading a rubber, a thermoplastic resin or a mixture thereof at 130 to 170 캜 as a substrate, 150 to 200 parts by weight of silica, 7 to 20 parts by weight of silane coupling agent, 15 to 50 parts by weight of processing oil and 7 to 20 parts by weight of activator, and kneading the kneaded product with respect to 100 parts by weight of the base material. Method of producing a silica masterbatch, characterized in that it comprises a step of producing into a desired shape by compressing after manufacturing into a phase. A rubber product manufactured using the silica masterbatch of claim 1.