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RUBBER
UBEPOL-BR
Structural factors
Factor | Index | | (1)Molecular weight | ML,[ ],Mw,Mn | | (2)Molecular weight distribution | Mw/Mn | | (3)Linearity of molecular chain | T-cp | | (4)Micro structure | Cis, Trans, Vinyl |
(1)~(3)These are factors controlled by changing polymerization condition.
(4) This factor is closely linked with linearity, so it is impossible to control only this factor.
Relation between micro structure and linearity is as follows:
| Low | <-- | Linearity | --> | High | | Low | <-- | Cis content | --> | High |
Characteristics of UBE's process
| Item | Characteristics | Example of grade | | Catalyst | Al-Co | - | | Linearity of molecular chain | Linearity is controlled by changinpolymerization conditiong. | BR150B-BR150L | | Molecular weight | Molecular weight is controlled by changing polymerization condition.
=>The amount of chain transfer reagent. | BR130B-BR150B | | Multi-step polymerization | It is possible that a different polymer is produced in each reactor.
=>Composite material of rubber with micro dispersed resin is produced. | VCR412 |
Characteristics of various UBEPOL-BR
| Grade name | ML1+4 | T-cp | Characteristics | | BR150 | 43 | 75 | (1)Standard type
(2)Well-balanced between processability and physical properties | | BR150B | 40 | 50 | (1)High chain branched type of BR150
(2)Easy compounding
(3)Good open roll mill processability at high temperature, and under high loading recipe | | BR130B | 29 | 30 | (1)Lower mooney viscosity type of BR150B
(2)More excellent processability than BR150B
(3)Most suitable for high loading of carbon black | | BR150L | 43 | 105 | (1)High chain linearity type of BR150
(2)Good extrudability
(3)Excellent abrasion resistance
(4)High rebound
(5)Lower heat build up |
Merit of UBEPOL-BR
| Grade type | Merit | | Linear
polymer | -
Small die swell (Small shrinkage)
In virtue of the reason as mentioned above, the dimensional stability after extrusion process is very excellent, and the part of the edge is a sharp shape. So, It means improving the uniformity of a tire and being suitable for thinning down the various components for a tire because of lightening. -
High extrusion rate
It means improving the productivity. As a result, it means realizing to reduce the manufacturing cost per a tire. -
Good mill behavior at low temperature
For that reason, it is possible to shorten the initial banding time. As a result, it means realizing to reduce the manufacturing cost per a tire. -
High rebound
It is suitable for the tire aimed lower rolling resistance. Lower rolling resistance means possessing better fuel economy. -
Excellent cut growth resistance at the practical strain
It is possible to ensure against risks, and prolong the lifetime. -
Low heat build up
It is possible to prevent the burst of the tire by generating internal heat. -
High abrasion resistance
It is possible to prolong the lifetime of a tire. As a result, the effect enables to thin a tread because of lightening. | | Branched
polymer | -
Low compound mooney viscosity
It is suitable for high loading of carbon black and easy compounding. -
Good mill behavior at high temperature
It is possible to ensure against risks at the mill before extrusion process |
Structure of VCR
| VCR | Matrix; high cis BR | | Dispersed phase; Syndiotactic 1,2-polybutadiene with high melting temperature |
The dispersion of SPB in BR matrix is as follows:
Transmission electron micrograph about the dispersion of SPB in BR matrix (bar = 1°C)
Morphology of SPB
- Melting point; about 200°C
- Crystallinity; 70~80%
- Size;
Comparison of size between SPB and carbon
black
| Object | Basic unit | Aggregation | | Radius (°C) | Specific surfacearea (m2/g) | Radius (°C) | Length (°C) | | SPB | 20~100 | 85 | less than 1 | 1~2 | | HAF carbon | 29 | 100 | less than 1 | - |
This is a standard grade of UBEPOL-BR and this grade is well-balanced between processability and physical properties.
MSDF
Raw Polymer Properties | | Unit | UBEPOL-BR150 | | Mooney Viscosity | Ml1+4, 100°C | 43 | | Solution Viscosity in 5 wt.% Toluene at 25°C(1) | cps | 75 | | Instrinsic Viscosity in Toluene at 30°C [*] | --- | 2.1 | | Microstructure | Cis | wt.% | 98 | | Trans | wt.% | 1 | | Vinyl | wt.% | 1 | | n-Hexane Insolubles | HI(2) | wt.% | --- | | Molecular Weight & Molecular Weight Distribution | Mw(104) | --- | 56 | | Mn(104) | --- | 20 | | Mw/Mn | --- | 2.8 | | Volatile Matter | wt.% | 0.3 | | Ash Content | wt.% | 0.05 | | Apecific Gravity | --- | 0.91 | | Oil Content | phr | --- | | Stabilizer Type | --- | Non-staining |
CompoundProcessing | | Unit | UBEPOL-BR150 | | Compound Mooney Viscosity | Ml1+4, 100°C | 60 | | Cure Characteristics(5) | Minimum Torque | ML | lb-in | 8.1 | | Maximum Torque | MH | lb-in | 38.0 | | | ts1 | min | 11.3 | | | tc(50) | min | 23.3 | | | tc(90) | min | 30.1 | | Mill Shrinkage | --- | 25 | | Extrudability(6) | Extrusion Rate | wt.% | 0.271 | | Length of Extrudate | wt.% | 46.5 | | Die Swell | wt.% | 1.86 | | Rating | Contour | wt.% | 3.0 | | Edge | --- | 3.5 | | Surface | --- | 4.0 | | Corner | --- | 3.5 | | Total | --- | 14.0 |
VulcanizateProperties | | Cure Minutes at 145°C | Unit | UBEPOL-BR150 | | Tensila Strength | 35' | MPa | 18.1 | | 50' | MPa | 18.0 | | Elongation | 35' | % | 510 | | 50' | % | 480 | | 100% Modulus | 35' | MPa | 2.0 | | 50' | MPa | 2.2 | | 200% Modulus | 35' | MPa | 5.2 | | 50' | MPa | 5.4 | | 300% Modulus | 35' | MPa | 9.3 | | 50' | MPa | 10.0 | Hardness
Type A Durometer | 35' | - | 61 | | 50' | - | 62 | Tear resistance
Die C | 35' | kN/m | 42 | | 50' | kN/m | 47 | | Rebound | 50' | % | 58 | Compression Set
Method B, 70°C, 72hrs | 50' | % | 16 | Goodrich Flex
0.175" Stroke, 55lb, 100°C | ^T | 50' | C | 32 | | P.S. | 50' | % | 8 | | Pico Abrasion Index | 50' | - | 209 | Lombourn Abrasion Index(8)
Iwamoto Seisakusyo, Japan | 50' | - | 100 | Cut Growth (2mm-->15mm)
De Mattia Flexing machine | 50' | times | 2,700 | Cut Generation
De Mattia Flexing Machine | 50' | 104 times | >30 | Wet Skid Resistance on safty-Walk
British Portable Skid Resistance Tester | 50' | - | 18 |
Test Result
Raw polymer properties | Sample name | UBEPOL-BR150B | UBEPOBR150L- | UBEPOL-BR150L | | Mooney viscosity | 40 | 43 | 43 | | Solution viscosity (1) in toluene at 25°C (cps) | 50 | 75 | 105 | |
| Intrinsic viscosity in toluene at 30°C | 2 | 2.2 | 2.3 | |
| Micro structure (wt%) | cis | 96.6 | 97.7 | 98.2 | | trans | 1.7 | 1.2 | 0.9 | | vinyl | 1.7 | 1.1 | 0.9 | | Molecular weight and distribution | Mw(104) | 52.4 | 53.9 | 55.8 | | Mn(104) | 16.4 | 19.3 | 24.3 | | Mw/Mn | 3.2 | 2.8 | 2.3 |
Compound properties | Sample name | UBEPOL-BR150B | UBEPOL-BR150 | UBEPOL-BR150L | | Mooney viscosity | 49.5 | 51.6 | 54.2 | | Curing rate | t10 (min.) | 10.6 | 10.3 | 10.1 | | t90 (min.) | 12.8 | 12.6 | 12.6 | | Extrudability(g/min.) | Extrusion rate | 66.7 | 72.7 | 74.5 | | Die swell | 4.87 | 4.52 | 4.32 | | Mill shrinkage (%) | 53 | 48 | 44 | | Tensile properties | 50% Modulus (MPa) | 0.22 | 0.22 | 0.22 | | 300% Modulus(MPa) | 0.28 | 0.25 | 0.2 | | 600% Modulus (MPa) | 0.39 | 0.29 | 0.23 | | Tensile strength (MPa) | 0.72 | 0.59 | 0.48 | | Elongation (%) | 1110 | 1220 | 1290 |
Vulcanizate properties | Sample name | | UBEPOL-BR150B | UBEPOL-BR150 | UBEPOL-BR150L | | Hardness | t90x2 | 55 | 56 | 56 | | t90x3 | 54.5 | 55.5 | 56 | | 100% Modulus (MPa) | t90x2 | 1.6 | 1.7 | 1.8 | | t90x3 | 1.6 | 1.7 | 1.7 | | 200% Modulus (MPa) | t90x2 | 3.7 | 3.8 | 3.9 | | t90x3 | 3.6 | 3.6 | 3.7 | | 300% Modulus (MPa) | t90x2 | 6.9 | 7.2 | 7.3 | | t90x3 | 6.7 | 6.9 | 7.1 | | Tensile strength (MPa) | t90x2 | 22.7 | 23.4 | 24 | | t90x3 | 22 | 23 | 23.6 | | Elongation (MPa) | t90x2 | 640 | 640 | 640 | | t90x3 | 630 | 640 | 640 | | Tear resistance (kN/m) | t90x2 | 64 | 66 | 68 | | t90x3 | 63 | 64 | 67 | | Rebound (%) | 61 | 64 | 66 | | Heat build up | T(°C) | 15 | 13 | 12 | | PS (%) | 6.5 | 4.9 | 4.1 | | Compression set (%) | 13.7 | 13 | 12.3 | | Cut growth rate dc/dn (10-6mm/cycle) | 5.3 | 3.7 | 3 | |
| Lambourn abrasion index (2) | 93 | 100 | 103 | | Pico abrasion index (3) | 96 | 100 | 103 | Dynamic viscoelasticity -tan - | 0.125 | 0.109 | 0.104 | | Specific gravity | 1.075 | 1.075 | 1.076 |
Note: (2),(3)Index against UBEPOL-BR150, higher value means better abrasion resistance
| Sample name | BR150B | BR150 | BR150L | | Mooney viscosity | 104 | 100 | 95 | | Extrusion rate | 92 | 100 | 102 | | Die swell | 93 | 100 | 105 | | Mill shrinkage | 91 | 100 | 109 | | Tensile strength | 122 | 100 | 81 | | Elongation | 91 | 100 | 106 |
| Sample name | BR150B | BR150 | BR150L | | Tensile strength | 96 | 100 | 103 | | Tear resistance | 98 | 100 | 104 | | Rebound | 95 | 100 | 103 | | Heat build up | 87 | 100 | 108 | | Lambourn abrasion | 93 | 100 | 103 | | Dynamic viscoelasticity | 87 | 100 | 105 |
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