Liquid and solid epoxy resin supply based on bisphenol A is specified for two separate end-use profiles: high-solids protective coatings and civil engineering polymer systems. The product line described as Liquid & Solid Epoxy Resin Supplier: Bisphenol A Base for Coatings & Civil includes liquid DGEBA with an epoxide equivalent weight of 180–195 g/eq by ASTM D1652, dynamic viscosity of 10–16 Pa·s at 25 °C by ASTM D2196, and hydrolyzable chloride below 500 ppm. Solid Type-1 resin exhibits an EEW of 475–550 g/eq and a Durran softening point of 70–85 °C. Higher molecular weight solid grades extend EEW to 2400–4300 g/eq; those resins control melt viscosity and chain extension in fusion-bonded coatings, civil pipe protection, and high-performance powder chemistry.

The reactive backbone is diglycidyl ether of bisphenol A (DGEBA). The liquid grade is predominantly the monomer with n=0, while solid grades contain oligomers with n≥1, shifting EEW, melt viscosity, and softening point upward. This molecular weight distribution influences not only bulk handling but also the final crosslink density, shrinkage, and substrate wetting.

Storage stability of liquid DGEBA is affected by crystallization below 5 °C; warming to 40–50 °C restores clarity without permanent polymerization, but repeated thermal cycles increase hydrolyzable chloride and reduce shelf life. Bulk tanks should be maintained at 30–35 °C with recirculation, not air sparging, to prevent moisture ingress. Solid resin stored above 28 °C may block; pallets should be stacked no more than two high to limit compaction of flakes in multiwall bags.

What Distinguishes Liquid and Solid BPA-Based Epoxy Grades in Bulk Supply?

Bulk supply logistics differ sharply by molecular weight. Liquid DGEBA is transferred in stainless steel tank trucks or epoxy-lined ISO tank containers with delivery temperature held at 20–30 °C; after discharge, nitrogen blanketing is required on heated storage tanks to prevent moisture uptake and oxidative yellowing. Solid Type-1 resin is pastillated or flaked on a stainless steel cooling belt and packed in 25 kg multiwall paper bags; storage above 28 °C leads to sintering and fused bags. Type-4 solid resin, EEW 800–950 g/eq, is milled to D50 < 100 µm for solvent-dissolved maintenance primers. Type-9 solid resin is supplied as coarse granules for high-molecular-weight thermoset formulation.

Mixing of two-component epoxy grouts uses a low-speed drill mixer until homogeneity is achieved.

For batch-to-batch consistency, suppliers control EEW and softening point to ±2% and ±1.5 °C respectively. Deviations in EEW alter stoichiometric hardener demand; a 5 g/eq upward shift in liquid DGEBA changes amine demand by approximately 1.5 wt% in a typical polyamidoamine formulation. This is critical in plural-component spray equipment where the A/B ratio is fixed.

Grade	Epoxide equivalent weight (g/eq)	Viscosity at 25 °C or softening point	Test method
Liquid DGEBA (n=0)	180–195	10–16 Pa·s	ASTM D1652; ASTM D2196
Solid Type-1	475–550	70–85 °C Durran softening point	ASTM D1652; ASTM D6090
Solid Type-4	800–950	95–110 °C Durran softening point	ASTM D1652; ASTM D6090
Solid Type-9	2400–4300	145–160 °C Durran softening point	ASTM D1652; ASTM D6090

Molecular weight distribution changes the performance envelope. Liquid DGEBA produces high crosslink density and a tightly packed network, giving higher Tg but lower flexibility. Solid resins increase phenolic-ether chain length, which lowers crosslink density and improves adhesion to oily or damp substrates in civil repair. This trade-off is exploited in cold-weather civil formulations by blending 10–20 wt% solid Type-1 resin into a liquid resin base to extend pot life and reduce exotherm without sacrificing compressive strength below 50 MPa.

The supplier’s unmodified liquid DGEBA is not suitable for direct food-contact linings; compliance with FDA 21 CFR 175.300 requires additional extraction testing and specific formulated systems. Similarly, bisphenol A content in solid grades remains below 1000 ppm free BPA in most industrial grades, but regulatory limits under REACH require the formulator to confirm end-use exposure scenarios.

High-solids anticorrosion primers formulated with liquid bisphenol A epoxy and a polyamidoamine curing agent require a stoichiometric epoxy-to-amine hydrogen ratio of 0.85:1 to 1.0:1. The resin side is charged into a high-speed disperser fitted with a Cowles blade; tip speed is maintained at 18–25 m/s during pigment dispersion. After 15–30 min induction at 23 °C, the mixed viscosity measured by ISO 2884-1 at 100 s⁻¹ falls to 450–800 mPa·s, allowing airless spray through a 0.33–0.48 mm tip. Skipping induction produces cratering and micro-roughness because amine migrates to the surface during early solvent flash. At wet film thickness above 200 µm, surface solvent evaporation outpaces internal diffusion, trapping solvent and reducing pull-off adhesion below 5 MPa when tested by ASTM D4541 after 7 days at 23 °C.

Solvent-borne maintenance primers using solid Type-4 resin dissolve the flake in xylene or methyl ethyl ketone at 40–50 wt% solids. Dissolution is slower than liquid resin letdown and produces a shorter wet edge, but the higher molecular weight imparts faster dry-to-handle time and improved initial hardness. These primers are usually applied by brush or roller; spray application requires further dilution to 24–28 s Ford cup 4 by ISO 2431, which lowers volume solids.

When Ambient Cure Falls Below 10°C, Civil Grout Modulus Development Becomes Non-Linear

Civil crack injection in concrete structures uses low-viscosity liquid bisphenol A epoxy conforming to ASTM C881. The resin is injected through packers spaced at 200–400 mm with a two-component injection pump capable of sustaining 7–14 MPa at the packer head; lower pressure fails to fill microcracks below 0.3 mm, while higher pressure widens existing cracks and propagates microcracking. Viscosity at 25 °C for crack widths 0.2–0.5 mm is specified below 250 mPa·s; higher viscosity causes packer pressure spikes and short penetration runs. The cure exotherm in bulk containers is suppressed by keeping mixed volume below 5 L; larger volumes can auto-accelerate and smoke on a construction site.

Below 10 °C, amine-epoxy cure rate decreases by approximately 50% for each 10 °C temperature drop; early compressive strength development becomes non-linear. Concrete substrates must have a moisture content below 4% by weight and no active water flow unless a moisture-tolerant amine is specified. Above 80% RH, conventional unmodified amine cure produces amine blush at the interface; adhesion by slant shear testing under ASTM C882 can fall below 25 MPa if this film is not mechanically removed. Published data for this specific configuration is limited because job-site water flow and crack cleanliness exert greater influence than laboratory conditioning.

External bonding of carbon fiber reinforced polymer sheets to concrete uses liquid DGEBA with EEW 180–195 g/eq as saturant. The mixed resin is rolled onto the sheet, and the composite cures under ambient conditions. Concrete surface tensile pull-off strength must exceed 1.5 MPa per ACI 440.2R; below this value, substrate failure dominates. The same resin type can be used for structural steel-to-concrete bonding if the steel is degreased and abrasive blasted.

Epoxy flooring systems based on bisphenol A liquid resin and filled with 300–400 phr graded silica are mixed in floor-grade planetary mixers. The mixed slurry is poured and spiked with a roller to release air; moisture vapor transmission from concrete substrates must be below 3 lb/1000 ft²/24 h measured by ASTM F1869. Above this limit, osmotic blistering occurs unless a moisture-tolerant epoxy primer is applied first. At 3 mm thickness, the typical epoxy floor system consumes 1.8–2.2 kg/m² of mixed binder plus aggregate. Power troweling is avoided for self-leveling systems because it closes the surface and traps carbon dioxide generated by ambient cure. Field cure checks use rolling vehicles only after surface hardness reaches Shore D 70 by ASTM D2240.

Application	Normative reference	Relevant property	Field control boundary
High-solids anticorrosion primer	ISO 12944-5:2019	Dry film thickness /salt spray	2 × 80 µm for C4; scribe creep < 6 mm after 1000 h ISO 9227
Concrete crack injection	ASTM C881-20	Gel time and viscosity	30–90 min gel time; viscosity ≤ 250 mPa·s at 25 °C
Self-leveling epoxy floor	EN 13813	Flow and hardness	Straightedge gap ≤ 0.5 mm under 2 m; Shore D 70 by ASTM D2240
Fusion-bonded epoxy rebar	ASTM A775/A775M	Holiday detection	No defects at 67.5 V wet sponge

Bisphenol A Resin Crosslink Density and Solvent Swelling in Immersion Coatings

Immersion-grade coatings based on liquid DGEBA cured with an aromatic amine achieve a glass transition temperature, Tg, of 110–130 °C after post-cure at 80 °C for 6 h; this reduces solvent swelling to below 5% by mass when tested per ISO 2812-1 in refluxing acetone for 24 h. A lower crosslink density from a polythiol cure would allow higher solvent uptake and softening; therefore, phenolic or aromatic amine hardeners are specified for fuel and solvent contact. In cyclic condensation testing under ISO 6270, free-film water uptake should be below 3% by mass; above 3%, blistering and cathodic disbondment from edges accelerate. Aqueous immersion above 60 °C requires glass transition temperature at least 25 °C above service temperature; otherwise whitening and adhesion loss occur.

Solid bisphenol A epoxy resin with EEW 800–950 g/eq is compounded with a phenolic hardener, calcium silicate filler, and 2-methylimidazole accelerator into fusion-bonded epoxy powder for reinforcement bar and pipe protection. Premix is extruded at barrel set points 80–110 °C and the extrudate is ground under cryogenic conditions to a particle size D50 35–50 µm. Application to preheated rebar at 232–260 °C produces a cured film thickness of 250–400 µm; rebar exit temperature and line speed are adjusted to maintain gel time 10–30 s and cure extent below the DSC residual exotherm limit of 5 J/g. Out-of-window bar temperature causes porosity and reduced adhesion to steel blasted to ISO 8501-1 Sa 2½.

Extrusion of powder coatings based on solid epoxy resin requires differential temperature control; at the mixing zone, a shift of +5 °C above the set point can initiate premature advancement because phenolic hardener and accelerator are already dispersed. A torque rise of more than 15% within the first L/D 10 indicates localized gel; the extrudate then exhibits gel particles and poor film smoothness. Conversely, a -5 °C deviation increases melt viscosity and reduces distributive mixing, leaving hardener-rich domains that produce under-cured coatings with poor solvent resistance. This operating window is tighter than for unfilled epoxy because accelerator content is already optimized for gel time at rebar line speed.

Formulating High-Solids Anticorrosion Primers with Liquid DGEBA and Polyamidoamine

High-solids primers formulated at volume solids 72–80% meet ISO 12944-5:2019 for corrosivity category C4 when applied at 2 × 80 µm dry film thickness. Surface preparation to ISO 8501-1 Sa 2½ or SSPC-SP 10 is mandatory; below this cleanliness, soluble salts and mill scale lift the coating within 6 months of sea-coast exposure. The mixed product is applied by plural-component airless spray with a fluid pressure of 20–25 MPa and block heating to 45–50 °C; without block heating, viscosity exceeds 900 mPa·s and atomization is incomplete. Recoat windows for polyamidoamine-cured films at 10 °C can extend to 72 h; after that interval, amine blush or surface cure can reduce intercoat adhesion below 3 MPa by ASTM D4541.

Formulation with liquid DGEBA alone often fails edge retention tests because surface tension pulls the wet film away from sharp edges before gelation. Addition of 10–15 wt% solid Type-1 resin in the hardener side raises low-shear viscosity and improves edge coverage, but it also shortens pot life by 15–20%. Spray operators compensate with lower block heating and smaller batch sizes. After 1000 h of neutral salt spray per ISO 9227, scribe creep is controlled below 6 mm if the zinc-free primer contains 20–30 wt% micaceous iron oxide and 10–15 wt% zinc phosphate.

For immersion service in methanol-free fuels, the same resin system is reformulated without zinc phosphate and with a phenol novolac-cured resin side; cyclic gasohol immersion under ASTM D6943 evaluates film softening. Published data for this specific configuration is limited; therefore, compatibility tests with the actual fuel batch are required before tank lining application.

Heavy equipment grouting and anchor fixing use high-flow epoxy mortar with a compressive strength above 70 MPa after 7 days at 23 °C; aggregate content is limited to 60–70 wt% of total mix to maintain flow. The mixed material must be placed within 25 min at 30 °C; field tensile pull-out values are invalid if substrate temperature falls below 10 °C.