Exolit Flame Retardants for Plastics

Transcription

1 Pigments & Additives Division Specialties Business Exolit Flame Retardants for Plastics > The Business Unit Plastic Industries offers an extensive range of flame retardants for thermoplastic and thermoset applications Exactly your chemistry.

2 Exolit Flame Retardants for Plastics > With its Exolit product range the Business Unit Plastic Industries offers an extensive range of flame retardants for thermoplastic and thermoset applications Contents Introduction 2 Flame retardants for thermoplastics 3 Flame retarded polyamides for E&E applications 3 Flame retarded polyolefins for E&E and building applications 5 Flame retardants for thermosets 7 Advantages of the systems 7 UP Resins (unsaturated polyester resins) 8 EP Resins (epoxy resins) 1 Printed circuit boards 11 Introduction The performance profile required of modern flame retardants has changed significantly in recent years. Alongside their effectiveness in the event of a fire, environmental considerations play an ever greater role in all phases of the product life cycle from production and processing through to actual use and end-of-life recycling. It s an issue that has been initiated by the end users of the products and followed up by the processors. As a global market leader in non-halogenated flame retardants, Clariant regards its offering of products that provide the greatest technical, economic and ecological benefits as being a responsibility. 2

3 Flame retardants for thermoplastics Flame retarded polyamides for E& E applications Exolit OP 1312 > low impact on mechanical properties > outstanding electrical properties > colorability > temperature stable > non-halogenated Technical data Exolit OP 1312 Delivery form white powder Decomposition temperature > 35 C UL 94 V-/P A 6/PA % Figure 1: Technical data of Exolit OP 1312 In the E&E industry it is necessary to have parts which are able to isolate high voltages. Plastics in general are well suited for this demand as they offer excellent electrical isolation properties as well as light weight and mechanical strength. Due to the well balanced properties glass fibre reinforced polyamides are often used as construction material in the E&E industry. However, they can ignite when exposed to a flame. In order to ensure the fire safety of the E&E equipment flame retardants are added to meet the various fire classes Clariant s new Exolit OP 1312 offers many advantages compared to the existing products on the market Compounds made with Exolit OP 1312 have a low density and combine good mechanical properties with high CTI values. E-Modulus [MPa] Tensile strength at break [N/mm 2 ] Elongation at break [%] Impact strength [kj/m 2 ] Notched impact strength [kj/m 2 ] CTI [V] without FR with 18% Exolit OP 1312 with 2 % Br-PS/6 % Sb 2 O 3 /.4 % PTFE Figure 2: Mechanical properties of glass fiber reinforced (3 % glass fiber content) PA 6.6 3

4 Flame retardants for thermoplastics Flame retarded polyamides for E&E applications Exolit RP grades > high efficiency > low impact on mechanical properties > excellent electrical properties > easy and safe handling > non-halogenated Technical data Exolit Exolit Exolit RP 69 RP 694 RP 695 Phosphorus [% (w/w)] Moisture content [% (w/w)] <.2 <.2 <.2 Carrier material Phenolic resin PA 6 PA 6 Delivery form Pastilles Granules Granules Figure 3: Technical data of Exolit RP grades The Exolit RP product range is based on red phosphorus and different carrier materials. Exolit RP concentrates are offered as granules resp. pastilles ensuring an easy and safe handling (figure 3). Due to the low dosage needed to achieve the UL 94 V- class at.8 mm thickness (approx % by weight, as pure red phosphorus) they show low impact on the mechanical properties thus making them ideal for technical applications (figure 4). Furthermore, high CTI values can be achieved. Concentrate PA 66-GF Exolit RP 69 Exolit RP 694 Exolit RP 695 Dosage [%] Young s modulus [MPa] (ISO 527-2) Tensile strength [N/mm 2 ] (ISO 527-2) Elongation at break [%] (ISO 527-2) Impact strength [kj/m 2 ] (Charpy, ISO 179/1eU) Notched impact strength [kj/m 2 ] (Charpy, ISO 179/1eA) Figure 4: Mechanical properties of glass fiber reinforced (35 % glass fiber content) PA 66 4

5 Flame retarded polyolefins for E&E and building applications Exolit AP 75x grades > high efficiency > good electrical and mechanical properties > excellent UV stability > low smoke density > low smoke gas corrosivity > good recyclability > non-halogenated In E&E equipment a variety of different thermoplastics are used. Wherever possible commodity polymers are used to design especially large parts. One commodity plastic grade which achieved a significant market share during the past years is polypropylene. In particular for flame retarded applications there a good opportunities to replace other materials by PP. In this context the Exolit AP 75x product group is successfuly used to obtain a plastic part with well balanced properties. In comparison to other nonhalogenated flame retardants like metal hydroxides it is possible to pass the UL 94 V- class with much lower dosages (approx. 3 % (w/w)). Therefore, the mechanical properties of the plastic are less effected. By using impact modified PP-Copolymers the mechanical properties can be further improved (figure 5). Exolit AP 7xx Exolit AP 75 Exolit AP 751 (TP) Exolit AP 752 Exolit AP 76 Standard grade Special grade for Advanced grade New grade for PP, for PP, PE reinforced PP for PP and PE with improved copolymers only thermal stability E-Modulus [MPa x 1] 13 Yield stress [MPa] PP-Homopolymer PP-Homopolymer + Exolit AP 75 Figure 5: Mechanical properties of polypropylene with Exolit AP Charpyimpact strength [kj/m 2 x 1] Charpy-Notched impact strength [kj/m 2 ] PP-Copolymer-I + Exolit AP 75 PP-Copolymer-II + Exolit AP 75 NEW Exolit AP 76 > improved thermal stability > enlarged processing window > same dosage level and mechanical properties as Exolit AP 75 5

6 In view of their asset values electronic installations, in particular, are at risk from even small volumes of smoke. Even if the fire is small, corrosive substances that are released e. g. by halogenated flame retardants or PVC can destroy entire installations by attacking the sensitive electronic components. The smoke analysis of polypropylene containing Exolit AP 75 makes the difference clear. Exolit AP 75 does not release any corrosive halogen hydrides and generates only insignificant amounts of toxic fumes such as HCN or NOx. Even the formation of carbon monoxide is extremely low (figure 6, for comparison the requirements of the Airbus Industries to ATS 1.1). Outdoor applications in the building and construction industry often require a durable UV stability. However, the high performance UV stabilisation of flame retarded plastics is often problematic due to antagonistic effects. In comparison to halogenated flame retardants with Exolit AP 75 it is possible to obtain excellent UV stabilities in combination with stabilisers of the HALS type. Corresponding materials have markedly higher resistance to discoloration as well as to embrittlement (figure 7). Concentration [ppm] Figure 6: Smoke analysis of burning PP containing Exolit AP 75 Irradiation time [h] HCN < 15* flaming conditions * Requirements of the Airbus Industries > 25 NO x < 1* after 4 minutes Exolit AP 75 Chlor. Cycloaliphate Brom. Phthalimide Irradiation time until severe yellowing in the Suntest Figure 7: UV stability of polypropylene with monomeric HALS CO < 35* smoldering conditions 6 2 6

7 Flame retardants for thermosets Under the brand name Exolit, Clariant supplies halogen-free, environmentally friendly flame retardants with an assured future for thermosets. Advantages of the systems > light weight/low density of the components Their advantage lies in their effectiveness, which enables very low concentrations to be used, while at the same time meeting the most stringent requirements. As a result favourable processing properties are imparted, accompanied by low specific weight and excellent mechanical values of the finished articles. > low processing viscosity > high glass contents are possible > halogen-free hand lay-up, resin transfer moulding, pultrusion and spray lay-up possible > low smoke density In the event of fire involving Exolitcontaining systems, a reduction in smoke density is apparent. Since no halogen-containing flame retardants are required, no corrosive fumes such as HCl are given off. These properties are of great importance in modern vehicle manufacture. > no corrosive smoke 7

8 UP Resins (unsaturated polyester resins) Lightweight construction achieved by using Exolit About 7 % of UP resin consumption in Europe is employed in fibreglass-reinforced applications, e. g. construction (about 27 %), transport (about 23 %), tanks and pipes (about 18 %) and electrical components (about 1 %). For all these applications, construction or safety regulations specify flammability classifications, necessitating the use of flame retardants. To meet these requirements, the use of halogenated UP resins (frequently combined with antimony trioxide as a synergist) and aluminum trihydrate (flame-retardant filler) has become standard practice in recent years. But aluminum trihydrate (ATH) in particular is likely to bring an increase in viscosity (owing to higher filler levels to reach the required fire retardation) and higher densities of the components. The Exolit grades offer major advantages here especially in applications in the construction, electrical and rolling stock sectors. By combining the Exolit products with aluminum trihydrate high flammability requirements can be met even with low filler levels. 8

9 Figures 8-11 Flame retardant concentration in UP resins Combinations of Exolit with ATH* compared to pure ATH*. Further results for other flame retardant classifications are available. FR content/phr FR content/phr NF P 92-51, class M2 (3 mm) 2 UL 94: V- (1.6 mm) ATH AP 422 RP 654 ATH AP 422 RP 654 Figure 8: NF P Construction industry Figure 9: UL 94 Electrical industry FR content/phr FR content/phr DIN 551 Part 2, S4 SR2 STZ (3 mm) ATH AP 422 RP 654 ATH Exolit AP 74 Figure 1: DIN 551 Rolling stock Figure 11: Flame retardant concentration to pass DIN 551 S4 SR2 (German railway standard) * ATH = aluminum trihydrate 9

10 EP Resins (epoxy resins) High flame retardant standards with excellent electrical properties achieved by using Exolit Over 65 % of EP resins are used in coatings all kinds of, a further 15 % in casting resins and about 1 % in printed circuit boards. Since these applications are concentrated in the construction and electrical sectors, where fire regulations are normally prescribed, it is necessary to use flame retardants. Current practice, especially where epoxy resins are used in printed circuit boards, is to employ brominated EP resins based on tetrabromobisphenol A. In the event of fire corrosive fire gases can occur, due especially to the presence of halogen compounds. By using Exolit non-halogen flameretarded printed circuit boards can be manufactured. Exolit AP 422 and Exolit AP 462 meet the fire regulations covering epoxy resin laminates for rolling stock. By using Exolit RP 65 the high levels of ATH* filler in electrocasting resin systems necessary for reaching UL 94: V- classification can be substantially reduced. FR content/phr 25 2 UL: 94 V- (1.6 mm) ATH AP 422 RP 65 Figure 12: Flame retardant concentration in EP resins: Combinations of Exolit with ATH * compared to pure ATH * * ATH = aluminum trihydrate 1

11 Printed circuit boards Glass reinforced printed circuit boards (PCBs) are widely used in comsumer electronics as well as computers, automotive, aviation equipment and instrumentation. Modern PCB laminates meet the UL 94 V- criteria at.8 and 1.6 mm thickness. To achive this standard, bromine is incorporated in the resins. In case of fire, brominated resins generate corrosive and toxic gases. There is an increasing demand for halogen-free laminates due to environmental concerns. At the same time, the glass transition temperature of the resins used for PCBs has to be increased from 13 C to >15 C. Cost effective halogen-free FR-4 and CEM laminates can be produced by using the new developed Exolit OP 93 flame retardant additive. Exolit OP 93 can be easily dispersed in epoxy resin solutions. A high shear mixer is essential for complete wetting and dispersing. 11

12 Please note This information is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should not therefore be construed as guaranteeing specific properties of the products described or their suitability for a particular application. Any existing industrial property rights must be observed. The quality of our products is guaranteed under our General Conditions of Sale. = Trademark of Clariant registered in numerous countries. Edition: August 26 Exactly your chemistry. Clariant International Ltd. Pigments & Additives Division Marketing Specialties Business Rothausstrasse Muttenz Switzerland Phone: +41/61/ Fax: +41/61/ Ruediger.Walz@clariant.com DA 415 E_8/6