CCP PVA TC-07P is a partially hydrolyzed polyvinyl alcohol (PVA) resin manufactured by Chang Chun Petrochemical, characterised by a 86.0–89.0 mol% degree of hydrolysis (DOH) and a 4% aqueous solution viscosity of 4.0–6.0 mPa·s at 20°C determined in accordance with DIN 53015. The product is supplied as a free-flowing white to pale cream powder with a volatile matter content not exceeding 5.0 wt% (ISO 4617:2000) and an ash content (as Na₂O) typically below 0.5 wt% (ISO 6854:2008). Its narrow molecular weight distribution and controlled residual acetyl content position TC-07P between cold-water-swellable low-DOH copolymers and fully saponified high-strength grades, offering a balance of surfactant-free colloidal stabilisation, film tensile strength, and controlled water sensitivity.
What Distinguishes TC-07P from Conventional Partially Hydrolysed Grades?
The defining departure from analogous products such as CCP BP‑17 (87.0–89.0 mol% DOH, viscosity 25.0–32.0 mPa·s) or standard 88 %-hydrolysed grades with medium viscosity lies in the markedly reduced solution viscosity coupled with retention of high ash cleanliness. During emulsion polymerisation, the lower molecular weight enables higher solids loading without exceeding critical shear stress thresholds in pumping and metering equipment. In continuous twin-screw devolatilisation units, a 0.5 wt% increase in TC‑07P protective colloid relative to a medium-viscosity grade shifts latex particle size distribution (PSD) from a monomodal 180–220 nm mean diameter toward a bimodal profile with a secondary population near 80 nm, observed via dynamic light scattering (ISO 22412:2017). This allows fine-tuning of rheology without co-surfactant addition, reducing total organic carbon load in reactor effluent. Ash reduction below the 0.5 wt% threshold directly suppresses thermal discolouration in hot-melt adhesive compounding, where residual sodium acetate acts as a catalytic dehydrator above 160°C.
Polymer Colloid Architecture Without Conventional Surfactants
In vinyl acetate, acrylate, and styrene-acrylic emulsion systems, TC‑07P functions as a single-component protective colloid and stabiliser. Grafting efficiency, measured by acetone extraction and 1H‑NMR end-group analysis, exceeds 60 % when the PVA is pre-dissolved at 90–95°C under moderate agitation (300–500 min−1 in anchor-stirred jacketed vessels) and pH is buffered between 4.5 and 6.0 with sodium bicarbonate or phosphate buffer. Below pH 4.0, acetal formation with residual aldehyde monomers accelerates, while above pH 7.5, base-catalysed ester hydrolysis increases residual methanol evolution and undermines latex shelf stability. Published production data from European acrylic dispersion plants indicate that replacing a 50:50 blend of alkylphenol ethoxylate surfactant and medium-viscosity PVA with 2.8–3.2 wt% TC‑07P (on monomer) yields coagulum levels consistently below 0.15 % on 100‑mesh screens for a butyl acrylate/styrene (60/40) copolymer, tested per internal quality control analogous to DIN EN ISO 4062:2017. Pre-filtration through a 50 µm bag filter prior to spray drying is recommended when latex is intended for redispersible powder production; failure to remove microgel particles originating from residual catalyst residues leads to powder caking at relative humidity above 55 %.
| Property | Test Method | Specification | Unit |
|---|---|---|---|
| Volatile matter | ISO 4617:2000 | ≤ 5.0 | wt% |
| Ash (as Na₂O) | ISO 6854:2008 | ≤ 0.5 | wt% |
| Degree of hydrolysis | JIS K 6726:1994 (back-titration) | 86.0–89.0 | mol% |
| Viscosity (4% aq., 20°C) | DIN 53015 | 4.0–6.0 | mPa·s |
| pH (4% aq. solution) | ISO 976:2013 | 5.0–7.0 | — |
| Mean particle size (dry powder, d50) | Laser diffraction (ISO 13320:2020) | 120–250 | µm |
Performance Limits in High‑Shear Adhesive Compounding
Adhesive formulators incorporating TC‑07P into hot-press lamination adhesives encounter a narrow processing window when co-plasticised with glycerol or sorbitol. At glycerol loadings above 12 phr (parts per hundred resin), the Vicat softening point (A50 method, ISO 306:2022) drops below 45°C, compromising stack storage stability in tropical climates. Conversely, plasticiser levels below 5 phr render the adhesive film susceptible to brittle fracture at −10°C, with elongation at break falling below 50 % (ISO 527‑3:2018, specimen type 5). Equilibration of the powder to 15–18 wt% moisture content in a 25°C, 40 % RH conditioning chamber for 72 hours prior to melt blending suppresses bubble entrapment in single‑screw extruders with L/D ratios of 24:1 to 30:1. Direct blending into polyvinyl butyral (PVB) interlayer formulations is contraindicated; the residual acetyl groups in TC‑07P plasticise the PVB matrix at concentrations as low as 0.5 wt%, reducing glass adhesion measured by compressive shear testing (ISO 12543‑4:2021) by 15–20 % relative to formulations omitting secondary PVA.
In textile warp sizing, TC‑07P is employed where cold‑water desizing is mandated and effluent COD constraints preclude the use of fully hydrolysed PVA grades requiring enzymatic or oxidative treatment. Size pick‑up on 100 % cotton ring‑spun yarn (Ne 30) applying a 7.5 % solution at 85°C in a single‑size box with squeeze‑roll pressure of 0.35 MPa yields size add‑on of 9–11 wt%. The film cold‑water dissolution time, measured per ASTM D6400‑19 modified to assess 25°C water, is 12–18 seconds, compared with >45 seconds for a 98 mol% hydrolysed grade of equivalent viscosity. Abrasion resistance (Zweigle G552 simulation) improves by 18 % when TC‑07P is premixed with 0.3 wt% polyethylene glycol (Mw 400) as a lubricity modifier, though yarn tensile elongation decreases by 2.1 percentage points. Caution is warranted when size reuse is practiced: the recirculation tank must be maintained above 20°C to prevent precipitation of the partial hydrolysate, and microbiological spoilage is more rapid than for fully saponified grades; an isothiazolinone‑based biocide at 15–25 ppm active ingredient is required for storage beyond 48 hours.
| Property | TC‑07P | Fully Hydrolysed PVA (98.5 mol%) | Medium‑Viscosity Partially Hydrolysed PVA (88 mol%, 25 mPa·s) | Test Method |
|---|---|---|---|---|
| Water‑contact angle after 24 h immersion | 32° | 38° | 28° | ISO 15989:2013 |
| Penetration depth into 80 g/m² woodfree paper (coating speed 800 m/min) | 4.8 µm | 2.1 µm | 6.3 µm | Cross‑section SEM/EDX |
| IGT pick strength (uncalendered) | 0.92 m/s | 1.15 m/s | 0.88 m/s | ISO 3783:2006 |
| Acrylate monomer barrier (methyl acrylate permeability at 40°C, 60 % RH) | 8.1 × 10−13 g·cm/cm²·s·Pa | 3.6 × 10−13 | 9.7 × 10−13 | Cup method (ASTM E96/E96M‑22) |
Injection Moulding Release and Co‑binder Technologies
In ceramic injection moulding of alumina green bodies, TC‑07P serves as both a surface‑active debinding aid and temporary binder. Feedstock containing 58 vol% alumina (d₅₀ 0.6 µm) and a binder system of paraffin wax, low‑density polyethylene, and stearic acid exhibits a 40 % reduction in injection pressure when 2.5 wt% TC‑07P is added relative to the organic phase versus an unmodified binder; however, published data for this specific configuration is limited to laboratory‑scale injection moulding machines (Arburg Allrounder 320C, 600 kN clamp force) and has not been validated on production tools exceeding 16 cavities. Thermal debinding ramp rates must not exceed 0.5°C/min in the interval 180–280°C to avoid blistering from rapid PVA decomposition. The ash specification below 0.5 wt% becomes critical in these applications; sodium levels above 0.3 wt% promote eutectic liquid‑phase sintering at temperatures as low as 850°C, distorting final part geometry. Combined thermogravimetric analysis‑Fourier transform infrared spectroscopy (TGA‑FTIR) of evolved gases confirms acetaldehyde and acetic acid as major decomposition products, necessitating exhaust ventilation with activated carbon filtration when debinding furnaces are operated in enclosed facilities.
The product’s compatibility with boric acid crosslinking has been exploited in water‑soluble temporary protective films for automotive glass. When 4 % aqueous solutions of TC‑07P are cast with boric acid at 0.05–0.12 phr, a reversible network forms; peel strength on soda‑lime glass measured via ISO 8510‑2:2008 increases from 0.3 N/25 mm to 0.8 N/25 mm, yet dissolution in a 40°C water spray completes within 90 seconds. Excess boric acid above 0.15 phr induces irreversible gelation after 48‑hour storage at 40°C, a failure mode observed in multiple batch trials at a European film converter.
