C5c9 copolymer petroleum resin

Comprehensive analysis of No. 5 and No. 6 carbon nine copolymer petroleum resins

I. Basic characteristics and process parameters

‌Composition and structure‌

C9 fraction is used as the main raw material, and it is obtained by copolymerization and modification with C5 fraction. It has both the flexibility of C5 resin and the high adhesion of C9 resin, and the molecular weight distribution range is 2000-500057.

‌Softening point‌: Adjusted according to application requirements, the typical range covers 90-130℃, and the corresponding softening points of No. 5 and No. 6 resins are 90-105℃ (low softening point) and 105-120℃ (medium softening point)47 respectively.

‌Chroma‌: The product color number covers 5# to 11# (light yellow to light brown), which is suitable for industrial scenes with moderate color requirements47.

‌Physical and chemical properties‌

Excellent acid and alkali resistance (pH tolerance range 3-12), ash content ≤0.1%, bromine value ≤0.5%, thermal stability can reach 180℃ (short-term tolerance)57.

Good solubility, compatible with solvents such as toluene, xylene, gasoline, and outstanding compatibility with polymer materials such as EVA and SBS57.

2. Core application scenarios

‌Rubber and tire industry‌

As a radial tire carcass adhesive tackifier, it improves the bonding strength between rubber and steel cord and reduces the risk of rubber delamination57.

In styrene-butadiene rubber (SBR) products, adding 3-5% can significantly improve the self-adhesiveness and tear resistance of the rubber57.

‌Adhesives and sealing materials‌

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Used in SBS hot melt adhesive and pressure-sensitive adhesive systems to balance initial adhesion and lasting adhesion, and replace rosin resin to reduce the risk of yellowing16.

In the backing adhesive formula of cold chain insulation board, it is compounded with hydrogenated DCPD resin (ratio 1:0.1-0.5) to achieve a melt viscosity of 13000 mPa·s (180℃) and high peel strength (65N/in)1.

‌Paint and road asphalt modification‌

Added to road asphalt to improve temperature resistance and anti-rutting performance, compounded with SBS modified asphalt to extend the service life of the road surface2.

As a brightener in inks and coatings, it enhances the adhesion and weather resistance of the paint film and is suitable for outdoor high-gloss coatings57.

III. Performance comparison and alternative solutions

‌Compared with traditional C9 resin‌: The copolymer resin has lower polarity, better compatibility with rubbers such as SBR and NR, and its thermal stability is improved by about 20%57.

‌Alternative options‌: When higher weather resistance is required, hydrogenated C5 resin (such as ExxonMobil products) can be compounded, and coumarone resin (addition amount ≤30%) can be mixed if a low-cost solution is required16.

No. 5 and No. 6 carbon nine copolymer petroleum resins continue to replace traditional single-component resins in the fields of rubber, adhesives and road engineering due to their adjustable performance and wide compatibility45.