KR101174389B1 - Rubber composition for cure bladder with improved release effect and method for preparation thereof - Google Patents

Abstract

PURPOSE: A rubber composition for vulcanization bladder is provided to remarkably improving releasing performance and gas transmittance, while maintaining physical/chemical properties of vulcanization bladder, thereby capable of reducing vulcanization process period, and extending life time. CONSTITUTION: A rubber composition for vulcanization bladder comprises 10-60 parts by weight of general filler, and 1-50 parts by weight of silicate mineral based on 100.0 parts by weight of raw rubber. A manufacturing method of the rubber composition comprises a step of manufacturing a first master batch, adding general filler and oil in order, and adding releasing filler; a step of manufacturing a second master batch by adding and mixing 1/2 of the first master batch, neoprene, and 1/2 of the first master batch; and a step of mixing 1/2 of the second master batch, a vulcanization resin, ZnO, and 1/2 of the second master batch.

Description

RUBBER COMPOSITION FOR CURE BLADDER WITH IMPROVED RELEASE EFFECT AND METHOD FOR PREPARATION THEREOF}

The present invention relates to a rubber composition for vulcanizing bladder with improved release effect and a method for manufacturing the same. More specifically, the present invention relates to a rubber composition for vulcanizing bladder comprising a silicate mineral containing magnesium as a releasing filler in addition to a filler generally used to improve the releasing effect of the vulcanizing bladder, and a method for producing the same.

Vortex bladder is commonly used in vulcanization processes for the determination of tire internal morphology and heat transfer.

This vulcanization bladder is used as a medium for heat source supply, and comes into contact with the inner liner rubber inside the crosslinked bladder and the uncrosslinked tire. At this time, the inner liner rubber causes crosslinking reaction and adhesion reaction with the surface of the bladder when crosslinking, causing tearing with the bladder, leading to a decrease in life and failure.

Conventional rubber composition for vulcanizing bladder was prepared by adding a filler to the raw rubber to withstand steam or hot water.

Recently, various additives have been used in rubber compositions or coatings or release agents have been applied to the surface of vulcanizing bladder to increase release properties. However, release agents have to be frequently applied and have problems such as flowing down or causing debris on the tire surface. When the coating is peeled off, the coating rapidly increases adhesion and is not permanent.

Therefore, in recent years, by adding an additive to a rubber composition to increase its own release property, a study of not using or reducing a coating agent or a release agent has been conducted. In order to improve the releasability, conventionally, waxes, oils, and amine process aids are applied.

Korean Patent Publication No. 1020040005285 (Patent Application No. 10-2002-0039785) is a compound having a releasability in a rubber composition for the tire breather is to add and mix a mixture of paraffin wax or micro crystalline rinse wax and aromatic and aliphatic hydrocarbon resin. Is disclosed.

In addition, Korean Patent Publication No. 1020010011810 (Patent application 10-1999-0031361) discloses that a certain amount of amide and amine-based processing aids that can have a release effect in the vulcanizing bladder composition.

Korean Patent Publication No. 1019970006383 (Patent application 10-1996-0028328) includes the corn oil in the vulcanizing bladder composition to improve the release properties of the cured bladder from the cured tire innerliner in contact with the bladder. It is disclosed.

In addition, the Republic of Korea Patent Publication No. 1020010100739 (Patent application 10-2000-0024440) is added to the bladder rubber composition by adding an oil having a property of releasability to impart releasability to the bladder itself, without having to use a separate release agent on the surface of the bladder It proposes a bladder rubber composition that can prevent the sticking phenomenon of the bladder and the inner part by enhancing the lubrication effect.

However, when waxes, oils, and amine process aids are used in the process to improve the release property as described above, the release property gradually decreases due to thermal aging, blooming, and the like, resulting in a decrease in productivity due to process change. The problem is being raised.

In addition, the application of such a material may cause a change in the chemical / physical properties of the rubber composition, which may reduce the durability life.

Therefore, the present inventors, while researching a solution to the above problems, in order to improve the releasability of the vulcanization bladder, when the silicate mineral containing magnesium in addition to the general filler as a filler to maintain the physical / chemical properties level of the vulcanization bladder While discovering that the releasability and air permeability can be improved while completing the present invention.

Republic of Korea Patent Publication No. 1020040005285 Republic of Korea Patent Publication No. 1020010011810 Republic of Korea Patent Publication No. 1019970006383 Republic of Korea Patent Publication No. 1020010100739

Accordingly, the present invention is to solve the above problems, the problem to be solved by the present invention is to improve the release effect by applying a silicate mineral containing magnesium in addition to the general filler to the rubber composition for vulcanizing bladder for improving the release effect To provide.

In addition, another problem to be solved by the present invention is to provide a rubber composition for vulcanizing bladder to improve the release effect by applying a silicate mineral containing magnesium in addition to the general filler to the rubber composition for vulcanizing bladder.

In order to solve the above problems, the present invention is a rubber composition for vulcanizing bladder, 10 to 60 parts by weight of the general filler with respect to 100 parts by weight of the raw rubber; And 1 to 50 parts by weight of a silicate mineral containing magnesium as a releasable filler.

In the rubber composition for vulcanizing bladder according to the present invention, it is preferable that the raw material rubber is butyl rubber alone or butyl rubber having a maximum of 35% by weight of neoprene combined as a resin vulcanizing additive.

The rubber composition for vulcanizing bladder according to the present invention comprises 65 to 100 parts by weight of butyl rubber and 10 to 60 parts by weight of general fillers based on 100 parts by weight of raw rubber mixed with 0 to 35 parts by weight of neoprene as a resin vulcanizing additive; 1 to 50 parts by weight of silicate mineral including magnesium; 3 to 15 parts by weight of vulcanizing resin; 0 to 20 parts by weight of oil; And 3 to 10 parts by weight of zinc oxide for resin crosslinking.

In order to solve the above another problem, the present invention

Using a Soviet polymer, adding general fillers and oils to the Soviet rubber polymers in order, and adding a releasable filler therebetween to produce a first Master batch;

Adding a first master batch 1/2, a neoprene and a first master batch 1/2 in order to mix to prepare a second master batch; And

It provides a method for producing a rubber composition for vulcanizing bladder comprising the step of mixing the second master batch 1/2, vulcanization resin, ZnO and the second master batch 1/2 in order.

In the method for producing a rubber composition for vulcanizing bladder according to the present invention, it is preferable that the rubber polymer is butyl rubber, the general filler is furnace black, and the releasable filler is a silicate mineral including magnesium.

The present invention has the following effects by applying a silicate mineral containing magnesium as a releasable filler in addition to the general filler to the rubber composition for vulcanizing bladder.

First, the releasability and gas permeability can be significantly improved while maintaining the physical and chemical properties of the vulcanization bladder.

Secondly, improvements in releasability and gas permeability can shorten vulcanization process time and extend life.

Third, it is possible to increase the work processability by enabling a smooth blending process in the production of the rubber composition through the manufacturing method according to the present invention.

Hereinafter, the present invention will be described in more detail.

Rubber composition for vulcanizing bladder according to the present invention, in the rubber composition for vulcanizing bladder, 10 to 60 parts by weight of the general filler with respect to 100 parts by weight of the raw rubber; And 1 to 50 parts by weight of silicate mineral including magnesium as a releasable filler.

Butyl rubber may be used as the raw material rubber, and a combination of butyl rubber and neoprene as a resin vulcanization additive may be used. In this case, neoprene is preferably combined with butyl rubber within the range of up to 35% by weight. When the content of the neoprene exceeds 35% by weight, not only the mixing is difficult, but also the gelation of the rubber may be caused by an increase in the exothermic temperature during the mixing.

The term "general filler" refers to a filler such as carbon black, silica, and the like, which is generally used in the art, and in general, it is preferable to use a furnace black (Furnace Black) as the rubber composition for the vulcanizing bladder.

In addition, as the releasable filler, a silicate mineral including magnesium having a high crystallinity and a laminated-plate-like structure may be used, and such a releasable filler may increase the releasability of the vulcanizing bladder to reduce the adhesiveness of the tire and the bladder and apply the release agent. By reducing the time required to reduce the vulcanization process time can be expected.

The silicate mineral including magnesium, which is the releasable filler, is a mineral called talc whose formula is H ₂ Mg ₃ (SiO ₃ ) ₄ or Mg ₃ Si ₄ O ₁₀ (OH) ₂ .

The silicate mineral containing magnesium is a material which is widely used in cosmetics and baby powders because the particles are smooth and finely ground, and the particle shape is a plate-laminated type with a specific gravity of 2.60 to 2.90, and 500 to 600 ° C, preferably 550 ° C. Ash over 90-99% ash, heat loss 0.03-1.0%, Sieve Residues 0-3.0% at 325 mesh Has

The releasable filler is used together with a general filler to improve releasability, and is preferably used in the range of 1 to 50 parts by weight based on 100 parts by weight of the raw rubber. When used in less than 1 part by weight, the effect of improving the releasability is insignificant, when used in excess of 50 parts by weight, It is difficult to mix and can cause performance degradation due to reduced physical properties.

In addition to the filler, the rubber composition for vulcanizing bladder may be a vulcanizing resin, zinc oxide for crosslinking the resin, oil, or the like.

As the vulcanizing resin, an alkyl phenol vulcanizing resin may be used, and may be used within the range of 3 to 15 parts by weight based on 100 parts by weight of the raw rubber.

In addition, castor oil may be used as the oil, and may be used within the range of 0 to 20 parts by weight based on 100 parts by weight of the raw rubber.

In addition, zinc oxide for crosslinking the resin may be used in the range of 3 to 10 parts by weight based on 100 parts by weight of the raw rubber.

In addition, a processing aid may be used in the rubber composition for vulcanizing bladder, stearic acid, a dispersion homogeneous agent, etc. may be used as the processing aid, and may vary depending on the blending method and the type of mixer, and within the range used in this field. May be included.

The rubber composition for vulcanizing bladder according to the present invention may be prepared by a three-batch mixing method, and specifically may be prepared by the following steps.

Mastication of the rubber polymer, addition to the soviet rubber polymer in the order of ordinary fillers (for example furnace black) and oils, between which releasable fillers (for example silicate minerals including magnesium) ) To prepare a first master batch;

Preparing a second master batch by mixing in the order of the first master batch 1/2, the neoprene and the first master batch 1/2; And

Mixing in the order of said second master batch 1/2, vulcanizing resin, ZnO and second master batch 1/2.

Here, the master batch means a compound rubber formed by dispersing the raw material rubber and additives.

The rubber polymer is preferably used within about 20 to 100 seconds, and butyl rubber is preferably used as the rubber polymer.

The Soviet process may also be referred to as a lowering operation, which means depolymerization by applying shear force and heat to the rubber to soften the rubber to a uniform plasticization state. The Soviet Union process has a low-temperature Soviet Union method and a high-temperature Soviet Union method, depending on the degree of the Soviet Union will be affected by the workability and physical properties of the rubber product. For example, when the Soviet work is insufficient, the physical properties of the product is lowered, the shrinkage is increased, the appearance is poor. On the contrary, when the Soviet Union becomes excessive, the physical properties of the product are greatly reduced, and the shrinkage property is very low, but the appearance is generally good. Soviet work according to the invention is done sufficiently within approximately 20 to 100 seconds.

Mixers that can be used during the Soviet process include, for example, a roll mill, a kneader, a Banbury mixer.

Then, general fillers such as furnace black and oils such as castor oil are sequentially added to the Soviet rubber polymer, followed by the addition of a releasable filler, followed by mixing at 25 to 50 rpm at a dump temperature of 150 to 185 ° C. Prepare the first master batch. Processing aids such as stearic acid or a dispersion homogenizer may be added to the process of preparing the first master batch.

Thereafter, the first master batch 1/2, the neoprene and the first master batch 1/2 are added in order and mixed at 25-50 rpm at a dump temperature of 150-185 ° C. to prepare a second master batch.

Subsequently, the second master batch 1/2, the vulcanizing resin, ZnO and the second master batch 1/2 are added in order A rubber composition is prepared by mixing at 25-50 rpm at a dump temperature of 140-175 ° C.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these do not limit the technical scope of the present invention.

Comparative example  One

Rubber polymers (butyl rubber), processing aids (stearic acid and dispersing homogenizer (DR501)) and oils (caster oils) were added in the amounts shown in Table 1 below, followed by mixing to prepare a first master batch. Subsequently, neoprene was mixed to the first master batch in an amount as shown in Table 1, followed by addition of a general filler (furnace black) to prepare a second master batch. The rubber composition was then prepared in a three-batch mixing mode in which vulcanizing resin (alkyl phenol) and zinc oxide (ZnO) were mixed in order in a second master batch 1/2.

Example  One

The rubber polymer (butyl rubber) was used in the Soviet Union, and the processing aid (dispersion homogenizer (DR501) and stearic acid), general filler (furnace black) and oil (caster oil) were used in the order of the Soviet rubber polymer as shown in Table 1 below. A first master batch was prepared by adding a silicate mineral including magnesium in the amount and mixing at 45 rpm at a dump temperature of 175 ° C. Subsequently, the first master batch 1/2, the neoprene and the first master batch 1/2 were added in this order, and then mixed at 45 rpm at a dump temperature of 170 ° C. to prepare a second master batch. Subsequently, and second master batch 1/2, vulcanized resin (alkyl phenol), zinc oxide (ZnO) and second master batch 1/2 were added sequentially, followed by mixing at a dump temperature of 145 ° C. at 30 rpm to mix the rubber composition. Prepared.

Example  2

A rubber composition was prepared in the same manner as in Example 1, except that the amount of the ingredients was changed as shown in Table 1 below.

Example  3

A rubber composition was prepared in the same manner as in Example 1, except that the amount of the ingredients was changed as shown in Table 1 below.

Amount of ingredient in units Weight portion ) ingredient Comparative Example 1 Example 1 Example 2 Example 3 Butyl rubber 95 95 95 95 Neoprene 5 5 5 5 Furnace black (n220) 60 60 60 60 Stearic acid One One One One Dispersion Homogenizer (DR501) 2 2 2 2 Silicate minerals including magnesium 0 3 5 10 Vulcanization resin (alkyl phenol) 8 8 5 8 Zinc oxide 5 5 5 5 Caster oil 6 6 6 6

Test Example

After pressing the rubber composition obtained in Comparative Example 1 and Examples 1 to 3 with a hot press for 60 minutes to prepare a plate having a thickness of 3 mm, hardness, 300% modulus (Modulus) according to ASTM-related regulations ), Tensile strength and elongation were measured, and the thermal conductivity and fatigue tests were measured before and after aging (100 ° C., 24 hours), and the results are shown in Table 2 below.

division Comparative Example 1 Example 1 Example 2 Example 3 Shore A 71 71 71 71 300% modulus 72 73 71 70 Tensile Strength (kg _f / cm ² ) 127 128 126 123 % Elongation 640 630 620 630 Thermal conductivity 0.3082 0.3022 0.3033 0.3103 Fatigue Test (Demattia) Before aging 100,000 100,000 100,000 100,000 After aging 70,000 70,000 70,000 6.5 million adhesiveness 0.35 0.32 0.31 0.29 Adhesive force (kg _f / cm ² ) 9.80 7.84 5.70 3.09

* Hardness means higher hardness.

* Tensile properties (300% modulus, tensile strength, elongation) means that the higher the value, the better each characteristic.

* Fatigue test means that the higher the number of times, the higher the durability, for example, fatigue resistance.

* The higher the value, the better the heat transfer.

* Adhesion shows the adhesive properties of the vulcanized inner liner rubber and the vulcanized bladder rubber composition.

* Adhesion shows adhesive properties of margarine tire innerliner rubber and vulcanized blatter rubber composition.

As shown in Table 2, it can be seen that the case of Examples 1 to 3 corresponding to the present invention as compared to Comparative Example 1 is excellent in the releasability, low adhesion and adhesive strength without a change in physical properties and fatigue properties.

In addition, when comparing the embodiments it can be seen that the higher the content of the silicate mineral containing magnesium, the better the releasability. However, if the silicate mineral content including magnesium increases considerably, there may be a change in the mixing properties and physical properties.

Claims (5)

In the rubber composition for vulcanizing bladder,
10 to 60 parts by weight of general filler, based on 100 parts by weight of raw rubber; And 1 to 50 parts by weight of a silicate mineral containing magnesium as a releasable filler.
The method of claim 1,
The raw material rubber is a butyl rubber alone or vulcanized bladder rubber composition for improving the release effect, characterized in that the butyl rubber combined with a neoprene up to 35% by weight as a resin vulcanization additive.
The method of claim 1,
10 to 60 parts by weight of a general filler, based on 100 parts by weight of raw material rubber mixed with 65 to 100 parts by weight of butyl rubber and 0 to 35 parts by weight of neoprene as a resin vulcanizing additive; 1 to 50 parts by weight of silicate mineral including magnesium; 3 to 15 parts by weight of vulcanizing resin; 0 to 20 parts by weight of oil; And 3 to 10 parts by weight of zinc oxide for crosslinking the resin Rubber composition for vulcanizing bladder with improved release effect characterized in that it comprises.
Using a Soviet polymer, adding general fillers and oils to the Soviet rubber polymers in order, and adding a releasable filler therebetween to produce a first Master batch;
Adding a first master batch 1/2, a neoprene and a first master batch 1/2 in order to mix to prepare a second master batch; And
Method for producing a rubber composition for a vulcanizing bladder comprising the step of mixing the second master batch 1/2, vulcanization resin, ZnO and the second master batch 1/2 in order.
The method of claim 4, wherein
The rubber polymer is butyl rubber, the general filler is furnace black, the releasable filler is a silicate mineral containing magnesium, the method for producing a rubber composition for vulcanizing bladder.