Application Data Sheet for Polypropylene (PP)

Transcription

1 FR-20 Magnesium hydroxide [Mg(OH)2] Application Data Sheet for Polypropylene (PP) F-37 FR-20, a series of high purity grades magnesium hydroxide, is offered by ICL-IP as inorganic halogen free flame retardants (FR) recommended where use of halogenated products is limited or prohibited. FR-20 is particularly suitable for use with PP. As a result of its chemical nature, high purity and excellent thermal stability (Table 1 and 2), FR-20 exhibits inherent advantages over other halogenated free FR additives currently used for the same applications. Table 1: Properties of FR-20 FR-20 grade S7 S10 CAS Number Assay, w% Specific gravity Molecular weight Bulk density, g/ml Particle size, µm (Malvern Mastersizer 2000) D D 90 < 6 < 6 Surface area (BET), m 2 /g 7±1 10±1 Grades with special surface treatments to optimize processability and properties are recommended with PP application. 1

2 The use of FR-20 is advantageous when the following properties are required: halogen-free flame retardancy low and non toxic smoke high thermal and long term heat aging stabilities dimensional stability after injection molding acid scavenger and heat stabilizer reinforcing filler improves tracking index FR-20, designed for high levels of fire retardancy (UL-94 class V-1 and V-0), is usually efficient at loadings between 40 and 65%. Thermal stability FR-20 has a high thermal stability up till C and its use is recommended where alumina trihydrate (ATH) is not sufficiently stable. Thermogravimetric analysis of FR-20 (Table 2) reflects its high thermal stability allowing high processing temperatures typical to PP. Its thermal stability combined with excellent resistance to degradation, makes it a product of choice when recycling is an issue. Table 2: Thermo gravimetric analysis (TGA-10 0 C/min in air) Weight loss, % Temperature, 0 C Excellent smoke suppressant FR-20 is also a powerful smoke suppressant and it is one of its main advantages over halogen- and antimony- based FRs. Halogen based PP compounds burn with intense black smoke leading quickly to high values of smoke density in a NBS 2

3 chamber (Figure 1). On the contrary, PP compounds flame retarded by FR-20 are generating very little quantities of smoke Figure 1: Smoke optical density of V-0 PP (NBS smoke chamber - ASTM E Flaming mode) Br FR + Sb2O3 (no FR-20) Optical density, DM Ref no FR 0 62% FR-20 (no Br FR) Time, min Surface treatment In order to cope with the high loadings needed to get class V-1 or V-0, surface treated grade FR is preferred for extrusion and injection moulding applications of PP. FR has indeed a good contribution to improve melt flow during injection molding (Figure 2). 3

4 Figure 2: Influence of surface treament on MFI (PP homo V-0 with 62% FR-20; 230 C kg) MFI, % PP ref. PP + FR PP + FR-20 untreated Processing conditions Tables 3 provides indicative formulations enabling to get class V-0 (1.6mm) with PP homo- and block copolymers flame retarded by FR and their properties. It may be advisable to feed FR in two steps: Circa 40% in the feeding zone The rest, 20-25%, at the end of the second third of the extruder via a sidefeeder. Typical processing conditions to compound and mold PP flame retarded with FR are as follow: Compounding: Compounding in a co-rotating twin-screw extruder (L/D = 32) Temperature profile, 0 C: Screw speed, Rpm: 430 Injection molding Temperature profile, 0 C Mold temperature, 0 C 80 4

5 Properties Properties achievable in PP homo- and block copolymers are summarized in Table 3. Table 3: Properties of PP flame retarded by FR Type of PP PP Homo PP Block copo Ref. no FR FR Ref. no FR FR Composition, w%: PP FR Properties: Flame retardancy: UL 94 (3.2mm), class NR V-0 NR V-0 LOI MFI, g/10 min (230 0 C; 2.16kg) Tensile: Max. strength, MPa Elongation at break, % Modulus, MPa Impact IZOD notched, J/m Applications The range of applications for FR in PP is very wide (Figures 3 & 4): E & E: switches, wire and cables, connectors Automotive: under the hood electrical parts, wire and cables, trimmings and cover panels Building: thermal insulation foam, panels, sheets, ceiling parts and films 5

6 Figure 3: Under the hood electrical parts Figure 4: Insulating foams 6

7 For further advice and assistance, contact our representatives in your area: North America Far East Ameribrom Inc. USA China Phone: ICL China Fax: Phone: Fax: Europe Main Office Eurobrom B. V. Phone: Fax: Japan Bromokem Ltd Japan Italy Phone: Fax: PM Chemicals Italy fr.bromokem@icl-ip.com Phone: Fax: Pacific Rim fr.it@icl-ip.com United Kingdom Asiabrom Ltd Hong-Kong Eurobrom UK Phone: Fax: Phone: fr.asiabrom@icl-ip.com Fax: Mobile: fr.uk@icl-ip.com Other Parts of the World Isbrom Phone: Fax: fr.isbrom@icl-ip.com Head Office ICL Industrial Products Phone: Fax: frinfo@icl-ip.com Tecnet