Меламин
- Название продукта: Меламин
- Сайт Factroy: Округ Юду, Ганьчжоу, Цзянси, Китай
- Запрос цены: admin@ascent-chem.com
- Производитель: Ascent Petrochem Holdings Co., Limited
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- Меламин обычно используется в составах, когда молярное соотношение формальдегида к меламину и pH/температура конденсации должны контролироваться в определенных диапазонах.
| Код ТН ВЭД | |
| химическая формула | C3H6N6 |
| молекулярный вес | 126,12 г /моль |
| внешность | Белый кристаллический порошок |
| запах | без запаха |
| плотность | 1,57 г/см³ |
| точка плавления | 345 °C (распадается) |
| точка кипения | Не применяется; распадается перед кипением |
| Температура распада | 345 ° С |
| Растворимость в воде | 3,1 г/л при 20 °C |
| Растворимость в органических растворителях | Нерастворим в большинстве органических растворителей |
| рН | Слабо щелочный (насыщенный водный раствор) |
| пКа | 5,0 (конюгированная кислота) |
| кристаллическая структура | Моноклиника |
| ЛогП | -1,37 |
| давление паров | <0,1 мПа при 20 °C |
| точка вспышки | > 300 ° C |
| Температура самозажигания | > 600 ° C |
Как аккредитованная фабрика Меламин, мы применяем строгие протоколы качества - каждая партия проходит тщательное тестирование для обеспечения последовательных стандартов эффективности и безопасности.
| Упаковка | Меламин поставляется в запечатанных 25 кг тканных полипропиленовых пакетах с внутренними полиэтиленовыми накладками, накладываемых на паллеты для промышленной обработки. |
| Погрузка контейнера (20-футовый контейнер) | Примерно 20 тонн меламина в 25-кг пакетах, паллетизированных, упакованных в сокращающиеся упаковке, загруженных в 20' FCL, надежно укладываемых для предотвращения перемещения во время транзита. |
| Доставка | Меламин обычно доставляется в качестве неопасного, не DG твердого вещества в 25 кг мешках, FIBCs, барабанах или насыпных. Хранить прохладным, сухим и вентилируемым, сохраняя контейнеры запечатанными и подальше от окислителей и влаги. Избегайте образования пыли, используйте соответствующие ОПО и проверяйте правила перевозчика и местных транспортных правил перед отправкой. |
| Хранение | Храните меламин в прохладном, сухом, хорошо вентилируемом месте подальше от прямого солнечного света и влаги. Держите контейнеры плотно закрытыми и должным образом маркированными. Предотвращение образования и накопления пыли. Отделяется от сильных окислителей, кислот и других несовместимых материалов. Используйте надлежащее вторичное содержание, когда это необходимо. Следуйте местным правилам и рекомендациям из листа данных безопасности. Обеспечьте хорошую вентиляцию и избегайте инхаляции или ко |
| Срок годности | Меламин является химически стабильным; хранится сухой, запечатанный и при комнатной температуре, он имеет неопределенный срок хранения без типичного срока действия. |
| Parameter | Overlay paper | Decorative paper | Core kraft paper |
|---|---|---|---|
| Resin solids at application | 55–65 wt% | 55–65 wt% | 45–55 wt% |
| Resin pick-up on dry paper | 60–70 wt% | 50–60 wt% | 30–40 wt% |
| Residual volatiles after drying | 6–8 wt% | 6–8 wt% | 5–7 wt% |
| Press temperature | 150–165°C | 135–150°C | |
| Press pressure | 7–10 MPa | 7–9 MPa | |
What limits hydrolysis resistance in melamine-modified wood panel adhesives?
Melamine is charged into an alkaline methylolation reactor with urea and formaldehyde at 10–25 wt% of total resin solids to produce MUF copolymers for moisture-resistant particleboard and medium-density fibreboard. The finished adhesive is adjusted to 65–68 wt% solids, 200–600 mPa·s at 25°C, and pH 8.0–9.0. On particleboard lines, resin is applied at 10–14 wt% dry resin on dry wood particles in a short-retention drum blender; ammonium chloride hardener is metered at 1–2 wt% on resin solids immediately before furnish blending. In MDF blowlines, the resin is injected into the fibre stream at 160–190°C and 0.8–1.0 MPa, where residence time must remain under 1 s to limit pre-cure. After blowline drying to 8–10 wt% fibre moisture, the mat is pressed at 180–220°C for 5–8 s/mm. The principal production failure is resin pre-cure caused by pH drift below 6.5 or by hardener overdose; this forms cured resin specks on the mat surface and reduces internal bond strength. Compliance is verified under EN 312:2010 grades P3 and P5, EN 622-5:2009 MDF.H, ISO 12460-5:2015 perforator formaldehyde emission, and CARB 93120.2 Phase 2 emission limits. Terminal products include moisture-resistant particleboard, MDF.H panels, laminate flooring substrate, and load-bearing boards for humid interior use.Sulfonated melamine-formaldehyde (SMF) polycondensate is applied as a high-range water reducer in concrete where high early-age strength and controlled slump retention are required without polycarboxylate chemistry. The resin is synthesized by sulfomethylating melamine with sodium metabisulfite and formaldehyde at pH 8.5–9.5 and 85–95°C, then condensed to an anionic polycondensate at 20–35 wt% solids. In concrete batching, the powder is dosed at 0.5–1.5 wt% by weight of cementitious binder; liquid grades are metered at 1.0–3.0 wt%. The admixture is introduced after the initial mixing water and cement have formed a slurry, not onto dry aggregate, because early adsorption onto limestone fines sharply reduces dispersing efficiency. Mixing continues at 25–40 rpm in a twin-shaft compulsory mixer for 60–90 s after admixture addition. Slump-flow performance is checked under ASTM C1611/C1611M-14, water reduction and setting time under ASTM C494-17 Type F/G, EN 934-2:2009 Tables 3.1 and 3.2, and GB/T 8076-2008. Water reduction at 1.0 wt% is commonly reported in the range 15–25%, dependent on cement C3A content, sulfate balance, and fly ash surface area. Overdosage above 2.0 wt% of powder can entrain air and delay initial set; published data on concrete containing more than 30% supplementary cementitious materials with SMF remain limited. Terminal products include self-consolidating concrete, precast facade elements, high-strength grouts, and gypsum board core slurries.Intumescent coating formulation at the APP–PER–MEL ternary threshold
Melamine functions as the blowing agent in waterborne and solvent-borne intumescent systems, where it is milled with ammonium polyphosphate and pentaerythritol. A starting formulation contains ammonium polyphosphate at 20–30 wt%, melamine at 10–20 wt%, pentaerythritol at 10–15 wt%, an acrylic or vinyl acetate binder at 25–35 wt%, titanium dioxide at 5–10 wt%, and dispersing/defoaming additives at 0.3–0.8 wt%. The coating is processed on a high-speed disperser with a Cowles blade at 2,000–3,000 rpm, then passed through a bead mill or three-roll mill until Hegman grind is 5–6. Application on structural steel uses an airless spray unit with 0.015–0.019 in tip, wet film thickness staged at 200–400 µm per coat, and dry film thickness typically 300–800 µm, depending on section factor and required fire resistance period under ISO 834-1. Melamine particle size should be maintained below 25 µm; coarser grades reduce char uniformity. Drying must remain below 180°C because melamine decomposition and ammonia evolution begin above approximately 250°C, and high-humidity exposure before curing accelerates ammonium polyphosphate hydrolysis. Fire performance is assessed under EN 13501-1:2018, ASTM E84-21, UL 723, NFPA 255, and ISO 5660-1:2015. Terminal products include fire-protective coatings for structural steel, cable trays, fire doors, and wall linings.| Component | Low expansion | Medium expansion | High expansion |
|---|---|---|---|
| Ammonium polyphosphate | 20 wt% | 25 wt% | 30 wt% |
| Melamine | 10 wt% | 15 wt% | 20 wt% |
| Pentaerythritol | 10 wt% | 12 wt% | 15 wt% |
| Acrylic binder | 35 wt% | 30 wt% | 25 wt% |
| Titanium dioxide | 8 wt% | 6 wt% | 5 wt% |
| Additives and water | to 100 wt% | to 100 wt% | to 100 wt% |
When MF moulding compounds enter food-contact article production
Melamine-formaldehyde moulding compound is formulated with 30–40 wt% MF resin binder, 25–35 wt% alpha-cellulose filler, 1–5 wt% pigment, 0.5–1.5 wt% zinc stearate lubricant, and 0.2–0.5 wt% latent acid curing catalyst. The compound is preheated to 80–100°C and compression-molded at 150–170°C under 25–40 MPa; injection molding uses clamp pressures of 80–150 MPa and cylinder temperatures below 95°C to avoid premature cure in the screw. Demolded articles are post-cured at 120–130°C for 2–4 h to reduce free formaldehyde and residual melamine migration. Food-contact compliance is governed by FDA 21 CFR 177.1460, EU Regulation 10/2011 with a specific migration limit of 2.5 mg/kg for melamine, and GB 4806.6-2016. Operational boundaries include acidic food simulants above 70°C, which can raise melamine migration beyond the SML if the article is undercured; molded parts should not be microwaved. Terminal products include dinnerware, appliance knobs, electrical switch housings, and toilet seats.Residual formaldehyde in crosslinking textile finishing: process boundaries
Highly methylated melamine-formaldehyde resin is used as a crosslinker in durable-press cotton and cellulosic blends. In pad-dry-cure finishing, the resin is dosed at 5–15 g/L of an 80 wt% solids product, with magnesium chloride catalyst at 0.5–1.5 g/L. Fabric is padded to 70–80% wet pick-up, dried at 100–110°C, and cured at 150–160°C for 45–90 s. In paper wet-strength applications, the resin is added at 0.5–1.5 wt% on dry fibre at pH 4.5–5.5, then cured on drying cylinders at 95–120°C. Compliance is assessed under Oeko-Tex Standard 100, GB 18401-2010, and FDA 21 CFR 176.180 for paper food-contact use. The main boundary is residual free formaldehyde; undercure below 140°C raises extractable formaldehyde, while overcure embrittles cellulosic fibres. Terminal products include wrinkle-resistant shirting, wash-resistant cotton table linens, paper towels, and wet-strength packaging board.Конкурентоспособные цены на Меламин, соответствующие вашему бюджету - гибкие условия и индивидуальные котировки для каждого заказа.
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Melamine, 1,3,5-triazine-2,4,6-triamine, is a white crystalline solid supplied under CAS 108-78-1 with molecular formula C₃H₆N₆ and molecular weight 126.12 g/mol. The dry compound contains 66.6% nitrogen by weight and decomposes in the range 345–354 °C at atmospheric pressure. Industrial grades are manufactured predominantly from urea and are controlled for purity, particle size, moisture, and slurry pH; these variables influence methylolation rate, dusting propensity, and storage stability. Table 1 lists a representative specification for resin-grade melamine. The values are grade-dependent and do not replace the supplier certificate of analysis.
| Parameter | Representative value | Test basis |
|---|---|---|
| Melamine purity | ≥ 99.0% by weight | HPLC, area normalization |
| Moisture | ≤ 0.10% | Karl Fischer coulometry |
| Ash content | ≤ 0.02% | Muffle furnace, 600 °C |
| pH, 10 g/L aqueous suspension | 7.5–9.5 | Suspension pH meter |
| Median particle size d50 | 20–60 μm | Laser diffraction, ISO 13320 |
| Particle size d90 | ≤ 100 μm | Laser diffraction, ISO 13320 |
Particle size distribution affects wetting and dispersion. A d50 of 20–60 μm and d90 of ≤ 100 μm are typical for resin and adhesive grades, while fine grades with d50 below 10 μm are specified for coatings and some flame-retardant dispersions. Regardless of grade, melamine is only sparingly soluble in water at 20 °C; solubility increases with temperature and under acidic conditions because of hydrolysis.
Melamine-Formaldehyde Networks Require Strict Molar Ratio Control
Production-scale resin reactors of 10–30 m³ with reflux condensers and internal cooling coils are used to condense melamine with aqueous formaldehyde. The initial methylolation is performed at 75–85 °C and pH 8.0–9.0; the exotherm is controlled by staged melamine addition and jacket cooling. After methylolation, condensation proceeds at pH 5.0–6.5 until water dilutability and gel time meet the target. Over-condensation can reduce gel time below 100 s at 100 °C; the batch is then cooled below 30 °C and adjusted to pH 9.0–9.5 to limit further advancement. Free formaldehyde in laminating resin is typically below 0.3%, but lower limits are required for low-emission wood panel adhesives.
The F/M ratio is not simply stoichiometric. Although the triazine ring carries three primary amine groups, steric hindrance and equilibrium methylolation prevent full substitution of all six active hydrogens under typical industrial conditions. Higher F/M ratios reduce free melamine and improve water dilutability but increase free formaldehyde and moisture sensitivity. Lower F/M ratios improve storage stability but can cause precipitation and uneven crosslinking in the finished laminate. The processing window between cloud point and over-condensation narrows as reactor solids increase above 60%.
What Limits the Replacement of Urea by Melamine in Thermoset Adhesives?
Urea-formaldehyde resins are lower in cost and cure at lower temperatures, but their cured networks are more susceptible to hydrolytic degradation and formaldehyde release. Melamine-formaldehyde adhesives provide higher crosslink density and better moisture resistance; comparative ASTM D570 water absorption and ISO 75 heat deflection data show the performance shift. In particleboard and medium-density fiberboard, melamine is often added as a co-monomer rather than a full replacement because of cost and press-cycle constraints. The higher cure temperature of melamine-containing resins can reduce line speed if press time is not adjusted.
| Parameter | Melamine | Urea | Benzoguanamine |
|---|---|---|---|
| Theoretical active hydrogens | 6 | 4 | 4 |
| ASTM D570 water absorption, cured resin film | 1.5–3.0% | 4–10% | formulation-dependent |
| ISO 75 heat deflection temperature | 150–190 °C | 90–120 °C | lower than melamine, formulation-dependent |
| Primary cost driver | triazine monomer cost | low-cost commodity | specialty monomer cost |
| Typical cure temperature in adhesive applications | 120–140 °C | 90–110 °C | 130–160 °C |
Benzoguanamine is a further alternative with lower theoretical reactive hydrogens than melamine and a phenyl substituent that reduces network density but improves organic solubility. Dicyandiamide and phenol-formaldehyde systems are chemically distinct and are selected for different cure chemistries. None of these alternatives reproduces the combined surface hardness, heat resistance, and stain resistance of melamine-formaldehyde at equivalent film weight.
When High-Pressure Laminate Press Cycles Fall Outside the Stable Cure Window
In high-pressure laminate manufacture, alpha-cellulose decorative paper is impregnated with melamine-formaldehyde resin to resin contents of 50–70% by dry weight and B-staged in air-float ovens. The prepreg residual volatile content is controlled between 5% and 8%. The layup is pressed in multi-opening hydraulic presses with 15–20 daylights at platen temperatures of 140–160 °C and specific pressures of 6–10 MPa. Platen parallelism is maintained within 0.1 mm/m; deviations can produce thickness variation and localized under-cure at the panel edges.
The stable process window is bounded on the low side by insufficient cure. If platen temperature falls below 135 °C or dwell time is too short, the degree of cure may be insufficient for ISO 4586-2 requirements for stain resistance, steam resistance, and surface wear. Residual methylol groups remain hydrophilic and can produce microcracking and haze after water exposure. On the high side, platen temperatures above 165 °C or excessive dwell can embrittle the surface and shift color. Moisture content above 8% in the prepreg stack can generate steam blisters during pressing.
In production-scale impregnation lines, wet pickup is monitored gravimetrically. A swing of more than ±2% in wet pickup alters final surface appearance and abrasion resistance. Catalyst level is adjusted with lower-cost paper grades and higher line speeds, but the adjustment reduces press latitude. Multi-daylight packs are assembled with release papers and mirror-finish press plates. Plate cleanliness and release-agent selection affect surface gloss and defect density. Dust or fiber between plates can create local pressure points that degrade laminate performance under ISO 4586-2 abrasion testing. Published data for specific catalyst-to-resin ratios is limited; mill-scale trials are typically required to define the exact window for a given paper and press combination.
Flame-Retardant Mode of Action in Intumescent Coatings and Flexible Foams
Melamine decomposes in the range 300–400 °C with endothermic release of inert nitrogen gas. In intumescent coatings, it is combined with ammonium polyphosphate and pentaerythritol; the melamine acts as a blowing agent and contributes to char expansion. Published formulations commonly use 20–40 wt% melamine in dry film solids, although published data for specific polymer grades is limited. In flexible polyurethane foam, addition levels of 10–30 phr are reported to improve flammability performance in small-scale tests such as UL 94, but the effect on tensile strength, elongation, and compression set must be evaluated at each loading.
The material does not melt into the polymer matrix, which imposes processing constraints. Particle size must be controlled because coarse fractions above 100 μm can block airless spray tips in coatings and can increase roll defects in thin films. High loadings increase viscosity and reduce film cohesion. Melamine is a halogen-free flame retardant and does not provide plasticizing action; its efficiency depends on the char-forming co-synergists and the polymer decomposition pathway.
Melamine-formaldehyde molding compounds are processed by compression or transfer molding at 150–170 °C and 20–40 MPa. Filled compounds exhibit high surface hardness and hot-water resistance, but they are more brittle than filled urea-formaldehyde compounds. Electrical properties are assessed under IEC 60243 for dielectric strength and ASTM D257 for volume and surface resistivity, depending on the part specification.
Silo storage of melamine powder requires combustible-dust management. Baghouses, silo vents, and conveying lines should comply with NFPA 652 and applicable ATEX provisions. Bulk material should be stored sealed at ambient temperature below 35 °C and relative humidity below 60% to prevent caking. Under these conditions, hydrolysis to cyanuric acid and ammonia is negligible. The rate increases under acidic conditions or hydrothermal exposure; therefore, melamine should not be stored near strong acids or steam. Dust accumulations on hot surfaces should be prevented because decomposition can liberate ammonia.
Sulfomethylated melamine-formaldehyde condensates are used as high-range water reducers in cementitious systems. The admixture disperses cement particles by electrostatic repulsion, allowing water reduction and improved early strength. Dosages of 0.5–2.0% by weight of cement are typical in mortars and self-leveling underlayments. Performance is evaluated under ASTM C494 for Type F or Type G water-reducing admixtures; specific dosage depends on cement fineness, supplementary cementitious materials, and placement temperature. Compared with naphthalene-derived high-range water reducers, sulfomethylated melamine generally produces less setting retardation at equivalent slump, but published comparative data for specific cement compositions is limited. The product is supplied as an aqueous solution or spray-dried powder.
Regulatory classification and registration must be confirmed for the specific grade and jurisdiction. For European Union applications, obligations under REACH apply. Food-contact uses fall within Commission Regulation (EU) No 10/2011 migration limits for plastics when used in laminated surfaces or coatings. In the United States, resinous and polymeric coatings may be subject to FDA 21 CFR 175.300 where applicable. Compliance requires batch-specific documentation because residual melamine and formaldehyde migration depend on cure conditions, molar ratio, and laminate construction.
