JPH10251453A - Nonsticky pipe conveyor belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the surface nonstickiness of a pipe conveyor belt by embedding a core material between an upper-side cover rubber made of a specific vulcanized rubber and a lower-side cover rubber. SOLUTION: A vulcanizate having an impact resilience of 65% or higher, a dynamic storage modulus E' of 2×10<7> Pa or lower, and a loss factor (tan δ) of 0.12 or lower is obtd. by vulcanizing a compsn. comprising 100 pts.wt. rubber component comprising 50wt.% or higher natural rubber and up to 50wt.% butadiene rubber, 5-50 pts.wt. carbon black, 15-200 pts.wt. calcium carbonate having an average particle size of 0.1mm or lower, and 0.5-15 pts.wt. mixture of 10-90wt.% fatty acid amide having an m.p. of 80-130 deg.C and 90-10wt.% paraffin wax of which the average number of carbon atoms is 40-70. A pipe conveyor belt of which a part is formed into a pipe shape when it is driven and parts in contact with the front and rear rollers are extended flat is obtd. by embedding a core material 3 (e.g. steel cords or canvas) between an upper-side cover rubber 1 made of the vulcanizate and a lower-side cover rubber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe conveyor belt to which powder or the like hardly adheres to the surface thereof, that is, to a pipe conveyor belt having excellent surface non-adhesion.

[0002]

2. Description of the Related Art As shown in FIG. 1, a pipe conveyor belt is an endless belt-shaped conveyor belt. , Which are developed into a flat plate and rotated. In the pipe conveyor belt, a conveyed material is input at a flat developing portion, and the conveyed material is discharged at the next developing portion. Such a pipe conveyor belt has been developed to prevent the powder and the like from scattering and falling, particularly when conveying cement powder, earth and sand, gypsum, powder and the like.

However, in the pipe-shaped part,
Although there is no powder drop, the input and discharge sections of the conveyed material are not pipe-shaped, so there is a problem that the conveyed material such as powder will scatter, fall, and significantly contaminate the surroundings in these parts. is there. Such scattering and falling of powder, etc., occurs when the powder or the like adheres to the belt surface and is released (released or released).
This is because it is hard to be done.

Japanese Unexamined Patent Publication (Kokai) No. 59-113043 discloses a material for a surface non-adhesive belt in which 2 to 60 parts by weight of a fatty acid amide having 5 to 26 carbon atoms is blended with 100 parts by weight of rubber. It is disclosed that the conveying belt is excellent in non-adhesiveness, and Japanese Patent Publication No. 57770/1994 discloses a rubber composition containing a grease-like or oil-like silicone compound such as polydimethylsiloxane. It is disclosed that the transport belt used is excellent in non-adhesiveness, but none of them has sufficient non-adhesiveness.

As described above, in a general conveyor belt,
Techniques for imparting non-adhesion by improving the composition of the cover rubber have been disclosed, but the non-adhesion is not sufficient, and there has been no non-adhesive pipe conveyor belt. Furthermore, since the pipe conveyor belt is rolled into a pipe shape, it becomes non-adhesive, smoothly forms a pipe, maintains its shape without sagging, becomes flat again, and has flexibility, resilience, and bending resistance. Etc., and it was difficult to satisfy these physical properties at the same time.

Japanese Unexamined Patent Publication No. Hei 6-336329 discloses a scraper-type belt cleaner that efficiently scrapes off deposits by pressing a cleaner chip against a belt surface with a uniform force. 27748
In Japanese Patent Publication No. 1 (1995), when the conveyor belt comes to the return side, the conveyor belt is passed through a cleaning tank having a cleaning liquid stored therein, is immersed in the cleaning liquid by an adhering substance peeling roll, and is given a bend. Techniques for peeling off deposits without being damaged have been disclosed, but all have the disadvantage of increasing the size of the apparatus, and are not applicable in the case of a pipe conveyor belt in which most of the belt is rolled into a pipe shape. It was difficult.

[0007]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a pipe conveyor belt having excellent surface non-adhesion.

[0008]

SUMMARY OF THE INVENTION The present invention is an endless belt-shaped conveyor belt in which a core is buried in a cover rubber, a part of which is rolled into a pipe shape during driving and is hung on a front roller and a rear roller. A pipe conveyor belt which is developed in a flat shape and rotates in a portion, wherein the cover rubber is made of a vulcanized rubber having a rebound resilience of 65% or more. Hereinafter, the present invention will be described in detail.

In the pipe conveyor belt of the present invention, the cover rubber is made of vulcanized rubber having a rebound resilience of 65% or more.
In the present invention, the rebound resilience is determined according to JIS K630.
It is a value measured by a rebound resilience test defined in 1-195 "Physical Test Method for Vulcanized Rubber".

The pipe conveyor belt of the present invention uses a vulcanized rubber having a rebound resilience of 65% or more as a cover rubber so that, for example, when a conveyed material is dropped from a shooter onto a pipe conveyor belt and supplied, The high rebound resilience prevents the load and the belt surface from sticking together, and the high rebound resilience of the belt surface causes the load to drop when released from the belt at the release (release or release) position. By flicking, it is possible to effectively prevent the powdery or particulate matter from adhering or sticking to the belt surface.

The pipe conveyor belt of the present invention has a core 3 embedded between an upper cover rubber 1 and a lower cover rubber 2 as shown in FIG. As the core, as shown, a steel cord is used, and a canvas is also used.

According to the pipe conveyor belt of the present invention, the dynamic storage elastic modulus E ′ of the vulcanized rubber is 2 in dynamic viscoelastic properties.
It is preferable that the pressure is not more than × 10 ⁷ Pa and the loss coefficient tan δ is not more than 0.12. The dynamic storage modulus E ′ and the loss coefficient tan δ are derived from complex modulus. Complex modulus is the stress-strain ratio of a viscoelastic material under a sinusoidal load. The complex elastic modulus is represented by the following equation (1).

[0013]

(Equation 1)

The storage modulus E 'of the complex modulus is the ratio of the steady state stress in phase with the strain to the magnitude of the strain. The portion of the complex modulus that is the loss modulus E ″ is similarly defined, but from the steady state strain the angle 90 ° in phase.
The component corresponding to the steady-state stress shifted by ° is used. The storage modulus E 'is a measure of the energy stored and recovered during a load cycle, and the loss modulus E "
It is proportional to the energy lost during this time. Loss factor ta
nδ is the ratio (E ″ / E ′) of the loss modulus E ″ to the storage modulus E ′. When E 'exceeds 2 × 10 ⁷ Pa, the flexibility and non-adhesiveness of the pipe conveyor belt are poor, and when tan δ exceeds 0.12, the resilience and non-adhesiveness of the pipe conveyor belt are poor.

In the present invention, since the rubber is inexpensive and the natural rubber is excellent in non-adhesiveness, the rubber is natural rubber, or the rubber comprises natural rubber and butadiene rubber. Is preferably 50% by weight or more of natural rubber.

Normally, the incorporation of a sequestering agent such as carbon black into the rubber lowers the rebound resilience of the vulcanized rubber, but by blending it in a predetermined range, the resilience of the resulting vulcanized rubber is ensured. While enhancing the effect of reinforcement and coloring, a pipe conveyor belt having excellent surface non-adhesion can be obtained. That is, in the present invention, the cover rubber is
Carbon black 5 to 50 per 100 parts by weight of rubber
It is preferable to comprise a vulcanized rubber obtained by vulcanizing a rubber composition containing parts by weight. If it is less than 5 parts by weight, there is no reinforcing and coloring effect, and if it exceeds 50 parts by weight, the resilience of the obtained vulcanized rubber is reduced.

The carbon black is not particularly restricted but includes, for example, furnace black, channel black, thermal black, acetylene black and the like.

In general, rubber itself is inferior in processability, so that various fillers are usually blended to reduce green strength and enhance processability. When the filler is added to the rubber, the rebound resilience of the vulcanized rubber is reduced, and as a result, the adhesion of the powdery or the like to the vulcanized rubber is increased. In the present invention, the rubber forming the cover rubber, by blending calcium carbonate as a filler in a predetermined range, while ensuring the resilience of the resulting vulcanized rubber, while improving the processability of the rubber, A pipe conveyor belt having excellent surface non-adhesion can be obtained.

That is, in the present invention, the cover rubber is used in an amount of 15 to 15 parts by weight based on 100 parts by weight of the rubber.
It is preferable to comprise a vulcanized rubber obtained by vulcanizing a rubber composition containing 200 parts by weight. If the amount is less than 15 parts by weight, the obtained vulcanized rubber is inferior in processability, and if it exceeds 200 parts by weight, the obtained vulcanized rubber is not only inferior in resilience but also inferior in processability. . More preferably, it is 30 to 100 parts by weight.

The calcium carbonate preferably has an average particle size of 0.1 mm or less. If it exceeds 0.1 mm, the non-adhesiveness is poor. The above calcium carbonate is preferably subjected to a surface treatment with a fatty acid. Examples of the fatty acid include rosin acid.

In the present invention, the cover rubber is a rubber 1
A mixture comprising 10 to 90% by weight of a fatty acid amide having a melting point of 80 to 130 ° C. and 90 to 10% by weight of a paraffin wax having an average number of carbon atoms of 40 to 70 based on 100 parts by weight.
It is preferable to comprise a vulcanized rubber obtained by vulcanizing a rubber composition containing 5 to 15 parts by weight.

In the present invention, when the belt is used, the fatty acid amide and the paraffin wax are both gradually transferred to the surface, that is, bleed to form a non-adhesive thin film on the surface of the belt. , Ozone deterioration can be prevented, and non-adhesion can be maintained for a long period of time.

In the present invention, if the fatty acid amide has a melting point of less than 80 ° C., the paraffin wax used in combination dissolves and forms a sticky surface when transferred to the belt surface. Is adhesive and 1
When the temperature exceeds 30 ° C., when kneaded with rubber, it becomes partially insoluble and does not uniformly disperse in rubber, and because of having a high molecular weight, the formation of a non-adhesive thin film on the belt surface also occurs. It becomes uneven.

Similarly, if the average number of carbon atoms of the paraffin wax is less than 40, the surface of the belt is made soft together with the fatty acid amide, and instead, the surface of the belt is made adhesive. At the time of kneading, it becomes partially insoluble and does not disperse uniformly in the rubber, and has a high molecular weight. As a result, the formation of a non-adhesive thin film on the belt surface also becomes uneven.

When the amount of the mixture of the fatty acid amide and the paraffin wax is less than 0.5 part by weight with respect to 100 parts by weight of rubber, it is insufficient to improve the non-adhesion of the belt surface. If it exceeds 10 parts by weight, a vulcanized rubber having required physical properties cannot be obtained. More preferably, 1 to 100 parts by weight of rubber
10 parts by weight.

In the mixing ratio of the mixture of the fatty acid amide and the paraffin wax, even if the fatty acid amide is less than 10% by weight or the paraffin wax is less than 10% by weight, the non-adhesive thin film Is uneven and the non-adhesion is poor.

The pipe conveyor belt of the present invention is prepared by blending the above-mentioned carbon black, the above-mentioned calcium carbonate, and a mixture of the above-mentioned fatty acid amide and the above-mentioned paraffin wax in the above-mentioned ranges, respectively, and vulcanizing the mixture to have a rebound resilience of 6%.
When the content is 5% or more, the obtained rubber compound has excellent processability, and the vulcanized rubber obtained by processing has excellent abrasion resistance and strength as well as surface non-adhesion. Thus, it is possible to obtain a pipe conveyor belt having excellent practicality and non-adhesive surface.

In the present invention, in addition to the above-mentioned carbon black as a reinforcing agent and calcium carbonate as a filler, a conventionally known rubber compounding agent is compounded into rubber, which is vulcanized to form a cover. It can be rubber.
Such compounding agents include, for example, vulcanizing agents such as sulfur;
Vulcanization aids; fillers such as talc, silicic anhydride, hydrous silicic acid, etc .; accelerating activators such as zinc oxide; softeners or plasticizers such as stearic acid and mineral oil; antioxidants; reinforcing agents; Tackifiers and the like can be mentioned.

The pipe conveyor belt of the present invention is prepared by adding a conventional compounding agent to rubber according to a conventionally known ordinary method, and preferably further comprising the above carbon black,
It can be obtained by blending the above calcium carbonate, and a mixture of the above fatty acid amide and paraffin wax, and molding the obtained rubber blend into a pipe conveyor belt. Usually, canvas or steel cord is used as the body.

Conventionally, in order to prevent the transported material from adhering to the surface of the transport belt, various stresses and impacts are applied to the belt when the belt is driven, and the transported material is dropped from the belt surface, and the transported material is dropped. It is known to adhere to the belt surface and prevent it from accumulating. By using the pipe conveyor belt of the present invention for transportation while applying various stresses and impacts in driving as described above, it is possible to more effectively prevent the transported material from adhering to the surface of the pipe conveyor belt. .

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Examples 1 and 2 and Comparative Example 1 A rubber compound was prepared according to the compound shown in Table 1, kneaded, and then vulcanized at 150 ° C. for 15 minutes to obtain a rubber compound having a size of 15%.
A test piece having a size of cm × 15 cm and a thickness of 2 mm was prepared. As the butadiene rubber, BR01 manufactured by Nippon Synthetic Rubber Co., Ltd. was used.
Asahi Carbon Co., Ltd., Asahi Thermal was used as the carbon black. Fatty acid amide / paraffin mixture has a melting point of 95 ° C
Of a fatty acid amide of 40% by weight and paraffin wax having an average number of carbon atoms of 60% by weight.

The rebound resilience is measured in accordance with JIS K 6301-19.
It was measured according to the rebound resilience test specified in 95 “Physical Test Method for Vulcanized Rubber”. The dynamic storage modulus E ′ and the loss coefficient tan δ were measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology).

The amount of adhering to the pipe conveyor belt was measured by carrying calcium sulfate dihydrate (special grade reagent) on a pipe conveyor belt according to the method described in Japanese Patent Publication No. 3-14062. That is, a test piece was set on the surface of the endless belt by making cuts in several places, and used as a test belt.
While traveling at 0 m / min, calcium sulfate dihydrate was continuously dropped from the hopper above the belt at a rate of 35 g / min onto the belt, and the calcium sulfate dihydrate was pressed against the belt surface with a press roll. For 30 minutes. Thereafter, the state of adhesion of calcium sulfate dihydrate to the test piece was visually observed. The results are shown in Table 1.

[0035]

[Table 1]

According to Examples 1 and 2 and Comparative Example 1, the pipe conveyor belt in which the vulcanized rubber having a rebound resilience of 65% or more according to the present invention as the cover rubber can significantly reduce the adhesion of the conveyed material. .

[0037]

As described above, the pipe conveyor belt of the present invention is excellent in surface non-adhesion. Furthermore,
Excellent wear resistance and strength can be imparted by blending the above-mentioned fillers and the like, so that it is excellent in practicality.

[Brief description of the drawings]

FIG. 1 is a partial schematic view of a pipe conveyor belt.

FIG. 2 is a sectional view of a pipe conveyor belt.

[Explanation of symbols]

 1 Top Cover Rubber 2 Bottom Cover Rubber 3 Core

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08K 3/26 C08K 3/26 // (C08L 21/00 23:00)

Claims (5)

[Claims] An endless belt-shaped conveyor belt having a core body buried in a cover rubber, a part of which is rolled into a pipe shape while being driven, and is developed into a flat plate shape at a portion where it is hung on a front roller and a rear roller. A pipe conveyor belt, wherein the cover rubber is made of vulcanized rubber having a rebound resilience of 65% or more. 2. The vulcanized rubber has a dynamic storage modulus E ′ of 2 × 1.
0 ⁷ Pa or less, and the loss coefficient tan δ is 0.
The pipe conveyor belt according to claim 1, wherein the number is 12 or less. 3. The pipe conveyor belt according to claim 1, wherein the rubber is natural rubber, or the rubber is made of natural rubber and butadiene rubber, and 50% by weight or more of the rubber is natural rubber. 4. A cover rubber comprising a vulcanized rubber obtained by vulcanizing a rubber composition containing 5 to 50 parts by weight of carbon black and 15 to 200 parts by weight of calcium carbonate based on 100 parts by weight of rubber. Item 4. The pipe conveyor belt according to item 1, 2 or 3. 5. A mixture comprising 10 to 90% by weight of a fatty acid amide having a melting point of 80 to 130 ° C. and 90 to 10% by weight of paraffin wax having an average number of carbon atoms of 40 to 70, based on 100 parts by weight of the rubber. The pipe conveyor belt according to claim 1, 2, 3 or 4, comprising a vulcanized rubber obtained by vulcanizing a rubber composition containing 0.5 to 15 parts by weight.