C5 hydrocarbon resin quality is evaluated through a combination of physical property tests (softening point, color, melt viscosity), chemical tests (bromine number/unsaturation, acid value, residual monomers), and application-specific tests (solubility, compatibility, storage stability) [1][2]. Softening point is typically measured by ring-and-ball per ASTM E28 (ASTM D36 is the bitumen counterpart; ASTM D-6493 appears in some commercial sales specifications); color by Gardner scale per ASTM D1544 (visual) or ASTM D6166 (instrumental, resin-specific); acid value by titration per ASTM D974; and bromine number by electrometric titration per ASTM D1159 [3][5][8][10]. Typical standard C5 resin specifications include: softening point ~95–105 degrees C, Gardner color ≤5–7, acid value ≤0.5–1.0 mg KOH/g, and bromine number typically 25–60 g Br/100g, grade-dependent [6][7][11].
1. What Is C5 Hydrocarbon Resin?
C5 hydrocarbon resin is a thermoplastic resin produced by polymerizing C5 fractions (aliphatic olefins and diolefins such as isoprene, piperylene, and cyclopentadiene) from petroleum cracking [2]. It is used as a tackifier in hot-melt adhesives, pressure-sensitive adhesives, road marking materials, and rubber compounding [1][2]. A dedicated C5 Hydrocarbon Resin grade is specified for softening point, color, and unsaturation level depending on the application.
2. Physical Property Tests
2.1 Softening Point (Ring-and-Ball)
What it measures: the temperature at which the resin softens sufficiently for a standard steel ball to fall through a ring under specified conditions [3][4].
Typical method: ASTM E28 (primary for hydrocarbon resins); ASTM D36 is the bitumen counterpart; ASTM D-6493 appears in some commercial sales specifications [3][4][7]. Note: ASTM D6192 is not a petroleum resin softening point standard - it covers apparel body measurement tables, a commonly confused reference.
Typical specification for standard C5: ~95–105 degrees C, with grade-specific tolerances (e.g., ±3 to ±5 degrees C); PICCOTAC 1095-N documented at 96 degrees C [5], Quintone K100 at 101 degrees C [6], Eastman sales spec 94–100 degrees C [7].
Why it matters: too low → softening or flow in high-temperature service; too high → poor flow and wetting during application [1].
2.2 Color (Gardner Scale)
What it measures: color intensity on the Gardner scale (1 = lightest, 18 = darkest) [8][9].
Typical method: ASTM D1544 (visual Gardner for transparent liquids) or ASTM D6166 (instrumental Gardner, resin-specific) [5][8][9].
Typical specification: Gardner ≤5–7 for standard C5 (PICCOTAC 1095-N at 3 [5]; Quintone K100 at 3 [6]); ≤1–3 for hydrogenated grades.
Why it matters: color contribution to the final adhesive, coating, or packaging; critical for light-colored or transparent products [1].
2.3 Melt Viscosity
What it measures: resistance to flow at a specified elevated temperature (e.g., 160–200 degrees C) [5].
Typical method: Brookfield viscometer per ASTM D3236 [12]; PICCOTAC 1095-N documented at 750 cP at 160 degrees C [5].
Typical specification: grade-dependent; often ≤250–1800 mPa·s at 160–200 degrees C depending on softening point and molecular weight [5][11].
3. Chemical Tests
3.1 Bromine Number (Unsaturation)
What it measures: the degree of aliphatic unsaturation, expressed as grams of bromine consumed per 100 g of resin [10].
Typical method: ASTM D1159 (electrometric titration) [10].
Typical specification for standard C5: grade-dependent, typically 25–60 g Br/100g; documented grades span 25 max (GA115B) [11] through 60 max, and 20–80 for road-marking grades [2]. Values below ~25 are typical of hydrogenated or highly saturated grades, not "standard" C5 [11].
Why it matters: unsaturation contributes to cross-linking and adhesion but also to oxidation, yellowing, and instability over time [1][10].
3.2 Acid Value
What it measures: residual acidity, expressed as mg KOH required to neutralize 1 g of resin [13].
Typical method: ASTM D974 (color-indicator titration) [13]; Quintone K100 documented at <0.1 mg KOH/g [6].
Typical specification: ≤0.5–1.0 mg KOH/g for standard C5 grades [6][13].
Why it matters: high acid value can cause corrosion in processing equipment and affect compatibility with certain polymers [1].
3.3 Residual Monomers (GC)
What it measures: unreacted C5 monomers remaining after polymerization and stripping [1].
Typical method: gas chromatography (GC), often headspace GC-MS [1].
Typical specification: grade-dependent. Food-contact grades require compliance with specific regulatory limits (FDA 21 CFR 175.105 for adhesives, EU 10/2011 for food-contact plastics) rather than a single universal ppm threshold [1][14].
4. Application-Specific Tests
4.1 Solubility and Compatibility
What it measures: whether the resin dissolves fully in the target solvent or base polymer without haze or phase separation.
Typical method: visual inspection of a 10–50% resin solution in a specified solvent (e.g., toluene) after equilibration; cloud point (MMAP/DACP) for polymer compatibility - PICCOTAC 1095-N documented at DACP 47 degrees C and MMAP 95 degrees C [5].
4.2 Storage Stability
What it measures: tendency of the resin to change in softening point, color, or acid value during storage.
Typical method: accelerated aging at elevated temperature (e.g., 60 degrees C for 30 days) followed by re-testing of key properties; ASTM D573 (rubber heat aging in air oven) is an analogous reference method. Note: this is an application-specific method; no single ASTM standard covers storage stability for all hydrocarbon resins.
5. Typical Specification Summary
| Parameter | Typical Range (Standard C5) | Test Method | Reference |
|---|---|---|---|
| Softening point (R&B) | 95–105 degrees C | ASTM E28 (D36 bitumen; D-6493 in some sales specs) | [3][4][5][6][7] |
| Gardner color | ≤5–7 (standard); ≤1–3 (hydrogenated) | ASTM D1544 / ASTM D6166 | [5][6][8][9] |
| Melt viscosity | Grade-dependent (e.g., ≤250 mPa·s at 200 degrees C) | ASTM D3236 | [5][12] |
| Bromine number | 25–60 g Br/100g (grade-dependent, standard C5) | ASTM D1159 | [10][11] |
| Acid value | ≤0.5–1.0 mg KOH/g | ASTM D974 | [6][13] |
| Residual monomers | Food-contact compliance per regulation | GC / GC-MS | [1][14] |
Note: these are typical ranges. Actual specifications depend on grade, manufacturer, and application. Always confirm with supplier TDS and COA.
6. What This Article Does NOT Claim
- No universal bromine number for standard C5 resin. Documented values are grade-dependent, typically 25–60 g Br/100g [10][11].
- No claim that ASTM D6192 covers petroleum resin softening point. ASTM D6192 is a body measurement standard (apparel sizing tables), not a petroleum resin method; ASTM E28 applies to hydrocarbon resins and D36 to bitumen [3][4].
- No universal "100 ppm" residual monomer limit. Food-contact compliance is regulation-specific (FDA 21 CFR 175.105 for adhesives; EU 10/2011 for food-contact plastics) [1][14].
- No specific customer case data or performance claims. Application-specific testing is required.
7. Conclusion
As the preceding sections show, C5 hydrocarbon resin quality is evaluated across three test categories: physical properties (softening point by ASTM E28, color by ASTM D1544 or D6166, melt viscosity by ASTM D3236), chemical properties (bromine number by ASTM D1159, acid value by ASTM D974, residual monomers by GC), and application-specific properties (solubility, cloud point compatibility, storage stability) [3][8][9][10][12][13]. Documented commercial anchors confirm the typical spec window: softening point 96–101 degrees C [5][6], Gardner color 3 [5][6], acid value <0.1 mg KOH/g [6], melt viscosity 750 cP at 160 degrees C [5], and bromine number 25–60 g Br/100g grade-dependent [10][11]. Boundaries are equally defined: ASTM D6192 is not a petroleum resin method [3]; bromine number is not a universal specification [10][11]; food-contact compliance is regulation-specific [14]. Every value in this article is a typical published range or supplier-documented figure; grade selection must be validated against supplier TDS, batch COA, and application-specific trial on the actual formulation.
8. Next Step
If you are evaluating C5 Hydrocarbon Resin for an adhesive, coating, or rubber application, send us:
- Application (hot-melt adhesive, PSA, road marking, rubber compounding)
- Required softening point and bromine number range
- Color and odor requirements
- Food-contact or regulatory requirement, if applicable
- Required documentation (TDS, COA, GC data, regulatory statements)
We will recommend a suitable grade and provide batch-specific property data for your evaluation.
Request C5 Hydrocarbon Resin TDS and COA →
References
- Orke Chemical. How Is the Quality of C5 Hydrocarbon Resin Controlled? Technical Blog. [QC parameters and evaluation methods for C5 hydrocarbon resin.]
- Orke Chemical. C5 Hydrocarbon Resin: Product Overview. [Applications and typical properties; monomer composition.]
- ASTM International. ASTM E28: Standard Test Methods for Softening Point of Resins Derived from Pine Chemicals and Hydrocarbons, by Ring-and-Ball Apparatus. West Conshohocken, PA: ASTM. [Primary softening point method for hydrocarbon resins.]
- ASTM International. ASTM D36: Standard Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus). West Conshohocken, PA: ASTM. [Bitumen-specific method; range 30–157 degrees C; noted for method comparison, not primary for hydrocarbon resins.]
- Synthomer. PICCOTAC™ 1095-N Hydrocarbon Resin TDS. [R&B 96 degrees C (ASTM E28); Gardner 3 (ASTM D6166, 50% in toluene); DACP cloud point 47 degrees C; MMAP cloud point 95 degrees C; Mn 1100/Mw 1980 g/mol; Tg 44 degrees C (DSC); melt viscosity 160 degrees C 750 cP (Brookfield).]
- Zeon. Quintone™ K100 C5 Petroleum Resin: Product Data. [Softening point 101 degrees C; Gardner color 3; acid value <0.1 mg KOH/g.]
- Eastman Chemical. Piccotac™ 1095-N Sales Specification No. 75223-12. [Color Gardner 5 max (ASTM D-6166); softening point R&B 94–100 degrees C (ASTM D-6493); notes D-6493 as alternate softening point method used in commercial sales specs.]
- ASTM International. ASTM D6166: Standard Test Method for Color of Naval Stores and Related Products (Instrumental Evaluation of Gardner Color Scale). West Conshohocken, PA: ASTM. [Instrumental Gardner color method specific to hydrocarbon resins; distinguished from visual D1544.]
- ASTM International. ASTM D1544: Standard Test Method for Color of Transparent Liquids (Gardner Color Scale). West Conshohocken, PA: ASTM. [Visual Gardner color method for transparent liquids.]
- ASTM International. ASTM D1159: Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration. West Conshohocken, PA: ASTM. [Bromine number as a measure of aliphatic unsaturation in petroleum samples.]
- GA115B Petroleum Resin Product Specification. [Bromine number 25 max g/100g (ASTM D1159); acid value 0.1 max mg/g (ASTM D664); 50% resin solids in toluene.]
- ASTM International. ASTM D3236: Standard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coating Materials. West Conshohocken, PA: ASTM. [Melt viscosity method; temperatures up to 260 degrees C.]
- ASTM International. ASTM D974: Standard Test Method for Acid and Base Number by Color-Indicator Titration. West Conshohocken, PA: ASTM. [Acid number by color-indicator titration.]
- U.S. Government Publishing Office. 21 CFR 175.105: Adhesives (FDA); and European Commission. Regulation (EU) No 10/2011 on Plastic Materials and Articles Intended to Come into Contact with Food. [Regulatory frameworks for food-contact compliance; formulation-specific.]
