CA1074524A - Process for the preparation of pulverulent batches of rubber and filler - Google Patents
Process for the preparation of pulverulent batches of rubber and fillerInfo
- Publication number
- CA1074524A CA1074524A CA227,129A CA227129A CA1074524A CA 1074524 A CA1074524 A CA 1074524A CA 227129 A CA227129 A CA 227129A CA 1074524 A CA1074524 A CA 1074524A
- Authority
- CA
- Canada
- Prior art keywords
- filler
- rubber
- mixing
- mixing vessel
- vessel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/12—Powdering or granulating
- C08J3/124—Treatment for improving the free-flowing characteristics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B7/00—Mixing; Kneading
- B29B7/002—Methods
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2321/00—Characterised by the use of unspecified rubbers
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
PROCESS FOR THE PREPARATION OF PULVERULENT BATCHES OF RUBBER AND
FILLER
Abstract of the Disclosure Process for the preparation of pulverulent batches of rubber and filler, wherein a comminuted rubber which still has the tendency to cake is mixed with filler in a high speed mixer and converted into a pourable powder.
FILLER
Abstract of the Disclosure Process for the preparation of pulverulent batches of rubber and filler, wherein a comminuted rubber which still has the tendency to cake is mixed with filler in a high speed mixer and converted into a pourable powder.
Description
~074S~
It is known that batches of rubber and filler can be obtained in the :~orm of pourable powders by precipitating rubbers from the latex phase with the addition of fillers as is desired in German Offenlegungsschrift No. 2,135,266 or 2,214,121 or U.S. Patent No. 3,714,087. The resulting rubber-filler batches have, however, relatively low bulk densities (0.15 to 0.3 g/cm3).
It is the object of this invention to provide a process by which a preground rubber powder which contains only small quantities of filler as grinding aid and therefore still has the tendency to cake together, can easily be converted into a permanently pourable pulverulent batch of rubber and filler with the desired quantity and desired type of filler. me fillers used as grinding aids may be silicic acids, ingredients which con-tain silicic acid, chalk, talcum, metal stearates or metal oxides.
m is invention therefore provides a process for the preparation of a pulverulent rubber-filler batch, wherein a comminuted rubber which still has the tendency to cake is mixed with fillers by a rapid mixing process and converted into a pourable powder.
According to the invention there is provided a process for the preparation of a rubber-filler batch, in which a comminuted rubber which contains smsll quantities of filler as grinding aid and which still has the tendency to cake is mixed, immediately after grinding, with 5-100 parts of filler per 100 parts of rubber by a rapid mixing process and converted into a pourable powder, said mixing taking place in a mixing vessel having a mix-ing element comprising a baton blade, double variant tool or impeller suction blade with ground cleaning element, the material in the mixing vessel being stirred at a temperature of from 20 to 80C and at a rotation of 200 to 5000 r.p.m.
To form the comminuted rubber, the rubber is ground with the addit-ion of small quantities of the above mentioned fillers (e.g. 2 to 3 parts by weight per 100 parts by weight of rubber) as grinding aid and then, according ~i~
B
- 10745Z~
to the invention, mixed with larger quantities of filler in a stirrer apparatus (e.g. at a speed of rotation of the stirrer of 1000 revs/min.) immediately after the grinding process.
The fillers used may be carbon blacks, silicic acids, ingredients containing silicic acid, chalk, talcum, metal stearates or metal oxides.
Suitable carbon blacks are summarized in Table 1. Carbon black N-770 (according to ASTM D 75-68) was used in the Example.
'.~
B -la-10745Z~
Table 1 Carbon black~
Classification of carbon blacks (accordi~ to ~STM-D 1765-68) Nome~clature AS~M ~y~e ~-301 MPC
S-315 HAF-~S SC
. N-326 HAF-LS
: N-327 HAF-LS
N 'l 40 FF
N.-539 FEF-~S
N-550 F~F
Le A 15 761 - 2 -1~74524 ~uring the stirring process, the filler is absorbed on the rubber powder obtained from the mill, which still has a tendency to cake and a freely pourable batch of rubber and filler is ob-tained (bulk density 0.4 to 0.5 g/cm3).
The mixers used for mixing rubber and filler have a speed of rotation of 200 to 5000 revs/min, preferably 1000 revs/min. The stirrer vessel is equipped with a double jacket to provide for cooling. The temperature of the wall has to be about 20C. The material treated in the mixer has to have a temperature of 20 to 80C, preferably about 50C during the stirring process.
The capacity of the mixing vessel used can be from 10 to 2000 l.
The power voltage of 380 volts consumption is from 7 to 200 amps, pre-ferably about 60 amps at 380 volts. In the case described here, an 80 l mixing vessel was used and the mixer~ were driven by a 45 KW motor.
The amount of filler used was 70 %. The mixing t~r~ used may consist of blades fixed to a vertical shaft or, a two-tier variant took (Figure 1) or impellers operating with suction and equipped with ground clearing devices may be used (Figure 2). These tools are all available commercially. The stirring process may be com-pleted within 1 to 5 minutes but is preferably carried out for one minute at the given speed of rotation of 1000 revs/min. The mixing vessel can be arranged either vertically or horizontally and i~ it Le A 15 761 - 3 -107452~
is arranged horizontally, stirring can be carried out as a conti-rLuous process.
It may therefore be regarded as an advantage of the above mentioned process that rubber powders which have the tendency to cake and which cannot be kept in a pourable state for a long time, for example due to high cold flow (4 to 20 mg/min; for method of measuring see below) can be converted into a pourable batch of rubber and filler by a simple stirring process ~ollowing the grin-ding process. The fluidity or caking resistance achieved is very high, being 30 lbs determined according to ASTM-D 1937-62 (packing force). The mixing tool can be separated from the grinding appara-tus so that both light coloured batches of rubber and filler and batches containing carbon black can easily be produced without the grinding apparatus itself becoming soiled or requiring clea-ning each time production is changed from one type of batch to another.
In the process according to the invention, therefore, poura-ble rubber powders are produced from rubber particles, preferably with a diameter of 500 to 2000 which still have the tendency to cake, the rubber powders being mixed with a filler (carbon black or light coloured fillers of the type mentioned above) in a mixing apparatus at speeds of rotation of 200 to 5000 revs/min, prefe-rably 1000 revs/min, for 1 to 2 minutes, the power consumption of the mixing apparatus being between 7 to 200 amps at 380 volts.
The filler (5 to 100 parts by weight per 100 parts by weight of rubber) is absorbed so rapidly on the rubber particles which are still slightly sticky that a completely pourable and non-caking batch of rubber and filler is obtained within a very short time (one minute). The particle size of the batch of rubber and filler corresponds to that of the rubber particles used.
Le A 15 761 - 4 -1074SZ'~
Example:
Polybutadiene (microstructure: % cis 1,4 98 - 20 %;
% cis 1,2 2 - 90 %) was ground with the addition of 3 phr of silicic acid. The powder, which had a strong tendency to cake, was mixed with 10 phr of SRF carbon black (N-770) in a high speed mixer at 1000 revs/min. The pourable product could be removed after one minute. The particle size was 1.2 mm, the bulk density determined according to DIN 53 468 is 0.5 g/cm3.
Natural rubber, styrene-butadiene copolymer, ethylene-propylene terpolymer, polychloroprene, isoprene etc. were con-verted into non-caking, pourable batches in the same manner.
The process is also applicable to all other types of rubber.
Cold flow method of determination The cylinder of the apparatus was filled with 1.5 g of polymer. The outflow nozzle was loaded with a weight of 1 kg and kept at 50C for 10 minutes.
The load was then removed from the test apparatus and any polymer overlfowing from it was cut off neatly.
The test apparatus was then kept at 50C under a load of 1 kg for a further 30 minutes while free outflow was provided for the polymer.
The amount of polymer which escaped from the apparatus was cut off and weight to thousandths of a gram.
The cold flow was expressed in mg/min.
Each polymer was tested 6 times and the average value ~btained was taken as a result.
Le A 15 761 - 5 -
It is known that batches of rubber and filler can be obtained in the :~orm of pourable powders by precipitating rubbers from the latex phase with the addition of fillers as is desired in German Offenlegungsschrift No. 2,135,266 or 2,214,121 or U.S. Patent No. 3,714,087. The resulting rubber-filler batches have, however, relatively low bulk densities (0.15 to 0.3 g/cm3).
It is the object of this invention to provide a process by which a preground rubber powder which contains only small quantities of filler as grinding aid and therefore still has the tendency to cake together, can easily be converted into a permanently pourable pulverulent batch of rubber and filler with the desired quantity and desired type of filler. me fillers used as grinding aids may be silicic acids, ingredients which con-tain silicic acid, chalk, talcum, metal stearates or metal oxides.
m is invention therefore provides a process for the preparation of a pulverulent rubber-filler batch, wherein a comminuted rubber which still has the tendency to cake is mixed with fillers by a rapid mixing process and converted into a pourable powder.
According to the invention there is provided a process for the preparation of a rubber-filler batch, in which a comminuted rubber which contains smsll quantities of filler as grinding aid and which still has the tendency to cake is mixed, immediately after grinding, with 5-100 parts of filler per 100 parts of rubber by a rapid mixing process and converted into a pourable powder, said mixing taking place in a mixing vessel having a mix-ing element comprising a baton blade, double variant tool or impeller suction blade with ground cleaning element, the material in the mixing vessel being stirred at a temperature of from 20 to 80C and at a rotation of 200 to 5000 r.p.m.
To form the comminuted rubber, the rubber is ground with the addit-ion of small quantities of the above mentioned fillers (e.g. 2 to 3 parts by weight per 100 parts by weight of rubber) as grinding aid and then, according ~i~
B
- 10745Z~
to the invention, mixed with larger quantities of filler in a stirrer apparatus (e.g. at a speed of rotation of the stirrer of 1000 revs/min.) immediately after the grinding process.
The fillers used may be carbon blacks, silicic acids, ingredients containing silicic acid, chalk, talcum, metal stearates or metal oxides.
Suitable carbon blacks are summarized in Table 1. Carbon black N-770 (according to ASTM D 75-68) was used in the Example.
'.~
B -la-10745Z~
Table 1 Carbon black~
Classification of carbon blacks (accordi~ to ~STM-D 1765-68) Nome~clature AS~M ~y~e ~-301 MPC
S-315 HAF-~S SC
. N-326 HAF-LS
: N-327 HAF-LS
N 'l 40 FF
N.-539 FEF-~S
N-550 F~F
Le A 15 761 - 2 -1~74524 ~uring the stirring process, the filler is absorbed on the rubber powder obtained from the mill, which still has a tendency to cake and a freely pourable batch of rubber and filler is ob-tained (bulk density 0.4 to 0.5 g/cm3).
The mixers used for mixing rubber and filler have a speed of rotation of 200 to 5000 revs/min, preferably 1000 revs/min. The stirrer vessel is equipped with a double jacket to provide for cooling. The temperature of the wall has to be about 20C. The material treated in the mixer has to have a temperature of 20 to 80C, preferably about 50C during the stirring process.
The capacity of the mixing vessel used can be from 10 to 2000 l.
The power voltage of 380 volts consumption is from 7 to 200 amps, pre-ferably about 60 amps at 380 volts. In the case described here, an 80 l mixing vessel was used and the mixer~ were driven by a 45 KW motor.
The amount of filler used was 70 %. The mixing t~r~ used may consist of blades fixed to a vertical shaft or, a two-tier variant took (Figure 1) or impellers operating with suction and equipped with ground clearing devices may be used (Figure 2). These tools are all available commercially. The stirring process may be com-pleted within 1 to 5 minutes but is preferably carried out for one minute at the given speed of rotation of 1000 revs/min. The mixing vessel can be arranged either vertically or horizontally and i~ it Le A 15 761 - 3 -107452~
is arranged horizontally, stirring can be carried out as a conti-rLuous process.
It may therefore be regarded as an advantage of the above mentioned process that rubber powders which have the tendency to cake and which cannot be kept in a pourable state for a long time, for example due to high cold flow (4 to 20 mg/min; for method of measuring see below) can be converted into a pourable batch of rubber and filler by a simple stirring process ~ollowing the grin-ding process. The fluidity or caking resistance achieved is very high, being 30 lbs determined according to ASTM-D 1937-62 (packing force). The mixing tool can be separated from the grinding appara-tus so that both light coloured batches of rubber and filler and batches containing carbon black can easily be produced without the grinding apparatus itself becoming soiled or requiring clea-ning each time production is changed from one type of batch to another.
In the process according to the invention, therefore, poura-ble rubber powders are produced from rubber particles, preferably with a diameter of 500 to 2000 which still have the tendency to cake, the rubber powders being mixed with a filler (carbon black or light coloured fillers of the type mentioned above) in a mixing apparatus at speeds of rotation of 200 to 5000 revs/min, prefe-rably 1000 revs/min, for 1 to 2 minutes, the power consumption of the mixing apparatus being between 7 to 200 amps at 380 volts.
The filler (5 to 100 parts by weight per 100 parts by weight of rubber) is absorbed so rapidly on the rubber particles which are still slightly sticky that a completely pourable and non-caking batch of rubber and filler is obtained within a very short time (one minute). The particle size of the batch of rubber and filler corresponds to that of the rubber particles used.
Le A 15 761 - 4 -1074SZ'~
Example:
Polybutadiene (microstructure: % cis 1,4 98 - 20 %;
% cis 1,2 2 - 90 %) was ground with the addition of 3 phr of silicic acid. The powder, which had a strong tendency to cake, was mixed with 10 phr of SRF carbon black (N-770) in a high speed mixer at 1000 revs/min. The pourable product could be removed after one minute. The particle size was 1.2 mm, the bulk density determined according to DIN 53 468 is 0.5 g/cm3.
Natural rubber, styrene-butadiene copolymer, ethylene-propylene terpolymer, polychloroprene, isoprene etc. were con-verted into non-caking, pourable batches in the same manner.
The process is also applicable to all other types of rubber.
Cold flow method of determination The cylinder of the apparatus was filled with 1.5 g of polymer. The outflow nozzle was loaded with a weight of 1 kg and kept at 50C for 10 minutes.
The load was then removed from the test apparatus and any polymer overlfowing from it was cut off neatly.
The test apparatus was then kept at 50C under a load of 1 kg for a further 30 minutes while free outflow was provided for the polymer.
The amount of polymer which escaped from the apparatus was cut off and weight to thousandths of a gram.
The cold flow was expressed in mg/min.
Each polymer was tested 6 times and the average value ~btained was taken as a result.
Le A 15 761 - 5 -
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of a rubber-filler batch, in which a comminuted rubber which contains small quantities of filler as grinding aid and which still has the tendency to cake is mixed, immediately after grinding with 5-100 parts of filler per 100 parts of rubber by a rapid mixing process and converted into a pourable powder, said mixing taking place in a mixing vessel having a mixing element comprising a baton blade, double variant tool or impeller suction blade with ground cleaning element, the material in the mixing vessel being stirred at a temperature of from 20 to 80°C and at a rotation of 200 to 5000 r.p.m.
2. A process as claimed in claim 1, in which the filler is a carbon black, silicic acid, composition containing silicic acid, chalk, talcum, metal stearate or metal oxide.
3. A process as claimed in claim 1 in which the mixer has a speed of rotation of 1000 revs/min.
4. A process as claimed in any of claims 1 to 3 in which the mixer vessel is provided with a double jacket to provide for cooling.
5. A process as claimed in any of claims 1 to 3 in which the mixer vessel wall is at a temperature of 20°C.
6. A process as claimed in claim 1 in which the material is at a temperature of 50°C during stirring.
7. A process as claimed in any of claims 1 to 3 in which the mixing vessel has a volumetric capacity of from 10 and 2000 l.
8. A process as claimed in claim 1 in which the power consumption of the mixing vessel is from 7 to 200 amps at 380 volts.
9. A process as claimed in claim 8 in which the power consumption of the mixing vessel is 60 amps at 380 volts.
10. A process as claimed in any of claims 1 to 3 in which the material to be mixed contained 70% of filler.
11. A process as claimed in any of claims 1 to 3 in which the rubber powder has a particle size of from 500 to 2000µ.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19742424249 DE2424249A1 (en) | 1974-05-18 | 1974-05-18 | PROCESS FOR THE PRODUCTION OF POWDERED RUBBER-FILLER BATCHES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1074524A true CA1074524A (en) | 1980-04-01 |
Family
ID=5915947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA227,129A Expired CA1074524A (en) | 1974-05-18 | 1975-05-16 | Process for the preparation of pulverulent batches of rubber and filler |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS511551A (en) |
| BR (1) | BR7503047A (en) |
| CA (1) | CA1074524A (en) |
| DE (1) | DE2424249A1 (en) |
| ES (1) | ES437720A1 (en) |
| FR (1) | FR2271033B1 (en) |
| GB (1) | GB1507691A (en) |
| IT (1) | IT1036897B (en) |
| NL (1) | NL7505823A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU508463B2 (en) * | 1975-07-03 | 1980-03-20 | Bayer Aktiengesellschaft and C-unter Papenmeier KG | Pulverulent rubber mixture |
| DE2616666A1 (en) * | 1976-04-15 | 1978-03-02 | Bayer Ag | COMPRESSING POWDERED RUBBER BLENDS |
| DE2648301C2 (en) * | 1976-10-26 | 1983-01-13 | Bayer Ag, 5090 Leverkusen | Process for the production of powdered rubber powder |
| DE2931793C2 (en) * | 1979-08-04 | 1982-05-13 | Metzeler Kautschuk GmbH, 8000 München | Process for the production of rubber articles by crosslinking a rubber mixture |
| JPS58152028A (en) * | 1982-03-05 | 1983-09-09 | Toagosei Chem Ind Co Ltd | Powdery polymer |
| US4599370A (en) * | 1984-12-06 | 1986-07-08 | Plastic Specialties And Technologies, Inc. | Powdered elastomer dry blends and process for injection molding |
| JPS6218214A (en) * | 1985-07-17 | 1987-01-27 | Japan Styrene Paper Co Ltd | Apparatus for heat-treating polyolefine resin particle |
| US6686410B1 (en) | 1998-11-03 | 2004-02-03 | Uniroyal Chemical Company, Inc. | Blending of polymeric materials and fillers |
| US7153895B2 (en) | 2001-09-12 | 2006-12-26 | Uniroyal Chemical Company, Inc. | Blending of rubber compounds, fillers and plasticizers |
| DE102006025848A1 (en) * | 2006-03-29 | 2007-10-04 | Byk-Chemie Gmbh | Production of composite particles for use e.g. in coating materials, involves pulverising particle agglomerates in carrier gas in presence of organic matrix particles and dispersing the fine particles in the matrix particles |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4879243A (en) * | 1972-01-26 | 1973-10-24 |
-
1974
- 1974-05-18 DE DE19742424249 patent/DE2424249A1/en not_active Withdrawn
-
1975
- 1975-05-14 GB GB2030875A patent/GB1507691A/en not_active Expired
- 1975-05-16 FR FR7515495A patent/FR2271033B1/fr not_active Expired
- 1975-05-16 IT IT4962975A patent/IT1036897B/en active
- 1975-05-16 ES ES437720A patent/ES437720A1/en not_active Expired
- 1975-05-16 BR BR7503888A patent/BR7503047A/en unknown
- 1975-05-16 NL NL7505823A patent/NL7505823A/en not_active Application Discontinuation
- 1975-05-16 CA CA227,129A patent/CA1074524A/en not_active Expired
- 1975-05-16 JP JP5753275A patent/JPS511551A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ES437720A1 (en) | 1977-03-16 |
| GB1507691A (en) | 1978-04-19 |
| JPS511551A (en) | 1976-01-08 |
| BR7503047A (en) | 1976-04-13 |
| FR2271033B1 (en) | 1979-04-13 |
| DE2424249A1 (en) | 1975-11-27 |
| NL7505823A (en) | 1975-11-20 |
| FR2271033A1 (en) | 1975-12-12 |
| IT1036897B (en) | 1979-10-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |