| Código SH | 133300 |
| Nome Do Produto | KURARAY POVAL 3-85 |
| Família Química | Álcool polivinílico (PVOH) |
| Número Cas | 9002-89-5 |
| Aparência | Pó granular branco |
| Grau De Hidrólise | 85,0 ± 1,0 mol% |
| Viscosidade Solução Aquosa A 4 A 20 C | 3,0 ± 0,5 mPa · s |
| Ph Solução Aquosa A 4 | 5,0 - 7,0 |
| Teor De Cinzas | ≤ 0,3% em peso |
| Conteúdo Volátil | ≤ 5,0% em peso |
| Grau Médio De Polimerização | 300 |
| Peso Molecular Médio | 15.000 g /mol |
| Densidade Aparente | 0,45 - 0,55 g /cm³ |
| Solubilidade Em água | Solúvel em água |
Como fábrica acreditada KURARAY POVAL 3-85, aplicamos protocolos de qualidade rigorosos - cada lote é submetido a testes rigorosos para garantir padrões de eficácia e segurança consistentes.
| Embalagem | KURARAY POVAL 3-85 é fornecido em sacos de papel multicamadas de 25 kg com forro de polietileno, garantindo manuseio e armazenamento seguros. |
| Carga de contêiner (20' FCL) | Carregamento de contêiner FCL 20 de KURARAY POVAL 3-85: sacos paletizados, arrumados com segurança, protegidos da umidade, garantindo o transporte seguro. |
| Envio | Kuraray Poval 3-85 navios como um pó de álcool polivinílico solúvel em água não perigoso. Deve ser transportado em sacos ou recipientes selados e à prova de umidade, mantidos secos e protegidos da dispersão de poeira. Evite calor excessivo, umidade e contato direto com oxidantes fortes. As condições padrão de carga seca com ventilação adequada garantem uma entrega segura. |
| Armazenamento | Armazene KURARAY POVAL 3-85 em uma área fria, seca e bem ventilada, bem vedada em seu recipiente original. Proteja da umidade, umidade e luz solar direta. Mantenha longe de calor, chamas e materiais incompatíveis. Evite o acúmulo de poeira e descarga estática. Use equipamentos limpos para evitar contaminação. Siga as diretrizes de armazenamento de polímeros e gire o estoque para manter a qualidade. |
| Prazo de validade | KURARAY POVAL 3-85 tem uma vida útil típica de dois anos quando armazenado em local fresco e seco, longe da umidade. |
Durante a polimerização de acetato de vinilo/etileno (VAE) em semi-lote em reatores de aço inoxidável revestido, o KURARAY POVAL™ 3-85 funciona como um colóide protetor enxertado e regulador de tamanho de partículas, com um grau nominal de hidrólise de 84–88 mol% e uma viscosidade de solução aquosa de 3,0–3,6 mPa·s a 20 °C. O pó é pré-dissolvido em água desmineralizada a 6-8% em peso e alimentado ao reator a 1,5-3,0% em peso com base no monômero total de acetato de vinilo, enquanto o reator também recebe persulfato de potássio a 0,05-0,15% em peso, tampão de bicarbonato de sódio para manter o pH 4,5-5,5, e, somente quando a distribuição bimodal de tamanho de partícula é necessária, um tensioativo não iónico a 0-0,5% em peso. A polimerização é executada a 70–85 °C com velocidade da ponta do impulsor de âncora 0,9–1,8 m/s; a dispersão resultante tem sólidos 55–62% em peso, viscosidade Brookfield 2.000–8.000 mPa·s, e pH 4,0–5,0. Em reatores de produção de 10 m³ equipados com impulsores de âncora de raspagem de parede, a viscosidade de dispersão de lote em lote é controlada dentro de ±10% alimentando a solução POVAL 3-85 a 0,8-1,2 L/min; a umidade relativa ambiente acima de 60% RH, o pó deve ser pré-seco para evitar grumados durante a composição da solução. O uso do POVAL 3-85 neste segmento deve observar as limitações de sua enxertabilidade - níveis excessivos de persulfato acima de 0,20% em peso podem degradar a espinha dorsal do PVOH e diminuir a resistência ao cisalhamento final do adesivo sob EN 204 D3/D4- e o composto é incompatível com adições de íons borato no adesivo acabado, o que pode aumentar a viscosidade de forma incontrolável. As dispersões terminais são usadas em colas de madeira de acetato de polivinilo cumprindo EN 204 D3/D4, adesivos de laminação de papelão, ligantes não tecidos e revestimentos arquitetônicos. As referências de conformidade incluem FDA 21 CFR 175.105 para adesivos em contato com alimentos, FDA 21 CFR 176.170 e 176.180 para componentes de papel e papelão em contato com alimentos, UE 10/2011 onde o artigo final é um material plástico em contato com alimentos, REACH registro e RoHS 2011/65/EU para artigos elétricos/eletrônicos se a dispersão entrar em tal cadeia de fornecimento.
Preços competitivos KURARAY POVAL 3-85 que se encaixam no seu orçamento - termos flexíveis e orçamentos personalizados para cada pedido.
Para amostras, preços ou mais informações, entre em contato conosco em +8615380400285 Ou envie para sales2@liwei-chem.com.
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KURARAY POVAL 3-85 is a partially hydrolysed polyvinyl alcohol grade supplied as a free-flowing powder. The grade name encodes two controlling variables: the viscosity band and the nominal degree of hydrolysis. For POVAL 3-85, a 4% aqueous solution at 20 °C exhibits a viscosity of 3.2–3.6 mPa·s when determined by JIS K6726 or ISO 1652. The degree of hydrolysis is specified between 84.5 mol% and 86.5 mol%; the residual acetate groups limit crystallite formation, reduce dissolution energy input, and provide cold-water solubility that is absent from fully hydrolysed PVOH grades such as POVAL 3-98. Typical additional release parameters include volatile matter not exceeding 5.0 wt%, ash no more than 0.4 wt% as Na₂O, and a 4% solution pH of 5.0–7.0. The product is used as a protective colloid in emulsion polymerisation, a surface size for paper and paperboard, a warp size for textiles, a binder for water-soluble and remoistenable adhesives, and a temporary binder in ceramics and pigment processing. The selection of POVAL 3-85 over POVAL 4-88 or POVAL 5-88 is generally made when the process requires lower solution viscosity at equal solids or when the end-use film must be removable in cold water. In contrast to POVAL 3-98, the lower hydrolysis level reduces film tensile strength and moisture resistance but improves adhesion to hydrophobic substrates and permits dissolution at 20–40 °C.
| Parameter | KURARAY POVAL 3-85 | Reference method |
|---|---|---|
| Viscosity (4% aqueous, 20 °C) | 3.2–3.6 mPa·s | JIS K6726 /ISO 1652 |
| Degree of hydrolysis | 84.5–86.5 mol% | JIS K6726 |
| Volatile matter | ≤5.0 wt% | JIS K6726 |
| Ash as Na₂O | ≤0.4 wt% | JIS K6726 |
| pH (4% aqueous) | 5.0–7.0 | JIS K6726 |
Batch release is therefore directed toward properties that influence downstream processing rather than a single performance claim. Because the viscosity test is carried out on a 4% aqueous solution, the preparation history of the solution must be controlled. Incoming inspection should include screen residue, volatile matter, and viscosity on the as-received powder after pre-drying at 60 °C for 4 h if the ambient relative humidity has exceeded 65% during storage. Powder screening at 500 µm before dissolution prevents hydrated gel fragments from interfering with capillary viscometry.
In a 1000 L jacketed stainless steel vessel equipped with a low-shear anchor impeller at 20–30 rpm, the powder is added to deionized water at 15–25 °C. The addition rate is controlled to 0.5–1.0 kg/min for a 500 L batch to prevent the formation of gel-coated lumps. Once the powder is dispersed, the batch is heated to 85–90 °C and held for 45–60 min. At 10 wt% solids, the solution remains pumpable at 60–70 °C; cooling below 40 °C increases viscosity sharply, particularly in concentrated solutions above 12 wt%. Heat-traced transfer lines maintained at 60–70 °C avoid gel-like stagnation, and filtration through a 100 µm bag filter removes hydrated agglomerates. Because the grade contains no added plasticiser, dried films cast from the solution are firm and may be brittle at low relative humidity; a plasticiser such as glycerol at 5–20 parts per hundred PVA is added when film flexibility is required. High-shear rotor-stator mixers above 5000 rpm are not required and may entrain air; when such mixers are used, defoamer levels of 0.1–0.3 wt% are typical.In vinyl acetate and vinyl acetate-ethylene emulsion polymerisation, KURARAY POVAL 3-85 is used as a protective colloid at 2–5 wt% based on total monomer. The colloid is charged as a 10 wt% aqueous solution at 60–65 °C. In a 1000 L reactor with an anchor impeller at 20–30 rpm, the lower viscosity of 3-85 compared with 4-88 is observed as reduced torque during the high-viscosity phase of polymerisation. The resulting latex particle size is typically controlled between 0.5 µm and 1.5 µm by adjusting the POVAL 3-85 level and initiator feed. Residual acetate groups in the colloid contribute to colloidal stability by steric repulsion, but the pH should be kept above 3.5 during storage to limit acid-catalysed hydrolysis of the acetate groups. Process water should be softened; calcium levels above 100 ppm may cause haze or filtration fouling when the latex is compounded with borax-free formulations. Polyvalent metal salts, particularly aluminium sulphate above 0.5 wt%, can destabilise the colloid and should be avoided unless a controlled coagulation step is desired.
In paper surface sizing, POVAL 3-85 is blended with oxidised starch at 1–3 wt% PVA on dry starch to increase film strength and water retention. The size-press bath is held at 60–70 °C; at this temperature the 4% viscosity of 3.2–3.6 mPa·s is sufficiently low for rod or film-press metering at line speeds above 600 m/min. Compared with POVAL 3-98, the partially hydrolysed grade does not require a fully hydrolysed dissolution temperature of 90–95 °C, which reduces steam use and permits size circulation at lower temperatures. In textile warp sizing on a multi-cylinder sizing machine, a size formulation containing 6–10 wt% POVAL 3-85 can be removed in a 40–60 °C wash bath without caustic soda. The lower tensile strength of the partially hydrolysed film relative to POVAL 3-98 limits its use on high-abrasion cotton warps at low sizing add-on; for high-tensile film requirements, a fully hydrolysed grade or a higher-viscosity partially hydrolysed grade should be evaluated.
Adjacent grades in the Kuraray Poval line are differentiated primarily by the viscosity band and the degree of hydrolysis. A comparison of release values illustrates the selection logic for converting operations.| Grade | Viscosity (4% aqueous, 20 °C) | Hydrolysis | Cold-water solubility | Typical processing boundary |
|---|---|---|---|---|
| POVAL 3-85 | 3.2–3.6 mPa·s | 84.5–86.5 mol% | Soluble at 20–40 °C | Emulsion stabiliser; paper and textile sizing |
| POVAL 3-98 | 3.2–3.6 mPa·s | 98.0–99.0 mol% | Requires 80–95 °C | Water-resistant film; hot-wash-resistant sizing |
| POVAL 4-88 | 4.3–4.7 mPa·s | 86.5–88.5 mol% | Soluble at 20–40 °C | Higher-viscosity adhesive; higher film strength |
| POVAL 5-88 | 5.0–5.7 mPa·s | 86.5–88.5 mol% | Soluble at 20–40 °C | Thicker films; higher binder strength |
The comparative table does not contain tensile strength values because published comparative data for non-plasticised films across these exact grades is limited. Selection should therefore be based on the viscosity and hydrolysis values on the certificate of analysis together with a laboratory cast-film test.
Formulations for remoistenable adhesives and water-soluble films use POVAL 3-85 at 10–15 wt%. The solution is prepared as described above and may be cast onto a release liner and dried at 80–100 °C. The film obtained from POVAL 3-85 redissolves in water at 20–25 °C; this behaviour distinguishes it from POVAL 3-98, which requires hot water or heated alkali for removal. In adhesive applications, plasticisers are necessary to reduce edge curl and brittleness. Glycerol, sorbitol, or polyethylene glycol 200–400 at 5–20 parts per hundred PVA are common. Borax or boric acid should be avoided above 0.5 wt% because crosslinking with the 1,3-diol units can cause rapid viscosity increase and gelation. Strongly alkaline pH above 10 should be avoided during long-term storage because the residual acetyl groups undergo base-catalysed hydrolysis, shifting the polymer toward fully hydrolysed behaviour and reducing cold-water solubility. Dried film properties are inferior to POVAL 3-98 in terms of tensile strength and water resistance; therefore POVAL 3-85 is not specified when the final film must remain intact under hot-water contact.
Because KURARAY POVAL 3-85 is hygroscopic, storage at relative humidity above 70% can raise volatile matter above 5.0 wt% and reduce powder flow through rotary valves. Bulk silos are fitted with desiccant dryers and vibratory dischargers. The powder is combustible as a dust; explosion protection measures follow EN 60079-10-2 zone classification and local dust extraction requirements. For food-contact applications, the end user must verify the specific compound against the relevant positive list and the migration limits of Regulation (EU) No 10/2011 or FDA 21 CFR 175.105 where applicable. The final certificate of analysis includes viscosity, degree of hydrolysis, volatile matter, ash, pH, and screen residue; no additional thermal or mechanical testing is performed at release. The grade is packaged in 20 kg multi-wall bags or 500 kg bulk bags.
