CN101307173A - Glass fibre reinforced halogen-free fire retardant PBT composite material and method for preparing same - Google Patents

Abstract

The invention discloses a glass fiber reinforced halogen-free fire-retardant PBT composite material and a method for preparing the same. The compositions by weight percentage of the composite material are: 40 to 60 percent of polybutylene terephthalate, 15 to 18 percent of halogen-free fire retardant, 20 to 40 percent of alkali-free glass fibers, 0.2 to 0.5 percent of silane coupling agent, 2 to 4 percent of grafting toughening agent, 0.1 to 0.3 percent of main antioxidant, 0.2 to 0.5 percent of auxiliary antioxidant and 0.2 to 0.5 percent of lubricant. The invention relates to the glass fiber reinforced halogen-free fire-retardant PBT composite material and the method for preparing the same. The composite material adopts the novel halogen-free fire retardant and corresponding processing aid and processing technique, thereby the composite material prepared is halogen-free, meets the fire-retardant standard of UL94V0, and maintains superior mechanical property, electric property, processability and chromaticity. The composite material is suitable for manufacturing parts and components of exported electronic and electrical products.

Description

A kind of glass fibre reinforced halogen-free fire retardant PBT composite material and preparation method thereof

Technical field

The present invention relates to technical field of polymer materials, relate in particular to a kind of glass fibre reinforced halogen-free fire retardant PBT composite material and preparation method thereof.

Background technology

Polybutylene terephthalate is called for short PBT, is by terephthalic acid and aliphatic dihydroxy alcohol esterifying polycondensation synthetic saturated polyester, and its constitutional features has phenyl ring, ester chain and is connected both ester group groups.Because the height geometrical regularity of molecule and rigid element make polybutylene terephthalate have higher mechanical strength, elasticity, wear resistance, chemical reagent resistance and good electrical property (still keeping the excellent electric insulating energy under high temperature and the wet environment) preferably, again because of there not being side chain in the molecule, symmetrical configuration, molecular chain can closely be piled up, and highly crystalline and high-melting-point are arranged.The PBT processibility is fabulous, is particularly suitable for processing some complex structures, thin wall parts.

Though PBT has above excellent properties,, reasons such as molding shrinkage big, easy firing relatively poor because of its resistance toheat are restricted the application of PBT.Therefore needing that PBT is carried out fire-retardant enhancing modified makes it have more excellent properties with meeting the market requirement.At present, it is that combustion-proof glass fiber strengthens PBT that PBT is carried out fire-retardant enhancing modified principal item, and the flame retardant of use is mainly bromide fire retardant, and bromine is that flame-retardant reinforced PBT has characteristics such as property retention is better, toxicity is bigger.Along with European and American countries to the implementation of environmental protection index and strictly regulate, each big electronic product manufacturer such as Dell, Hewlett-Packard, apple, elite etc. have put into effect the control documents about content of halogen respectively, the Halogen index will begin to carry out on January 1st, 2009, and halogen flame retardant strengthens PBT and soon withdraws from the electronic product industry gradually.In the case, glass fibre reinforced halogen-free fire retardant PBT is trend of the times, will be promoted faster and develop in electron trade.

Summary of the invention

The technical problem to be solved in the present invention provides novel halogen-free flame-retardant PBT matrix material of making a kind of high rigidity, low molding shrinkage, high heat distortion temperature and preparation method thereof.

For solving the problems of the technologies described above, the objective of the invention is to be achieved through the following technical solutions.

A kind of glass fibre reinforced halogen-free fire retardant PBT composite material, its composition is (%) by weight ratio:

Polybutylene terephthalate 40-60%;

Halogen-free flame retardants 15-18%;

The fine 20-40% of non-alkali glass;

Silane coupling agent 0.2-0.5%;

Grafting toughner 2-4%;

Primary antioxidant 0.1-0.3%;

Auxiliary antioxidant 0.2-0.5%;

Lubricant 0.2-0.5%.

Wherein: described polybutylene terephthalate relative density 1.31-1.34 gram/cubic centimetre.

Wherein, described grafting toughner is the POE grafts.

Wherein: described primary antioxidant is a pentaerythritol tetrathioglycollate, antioxidant 1010.

Wherein: described auxiliary antioxidant is a GW-540, oxidation inhibitor 168.

Wherein: described lubricant is N, the N-ethylenebisstearamide.

A kind of preparation method of glass fibre reinforced halogen-free fire retardant PBT composite material comprises step:

A: take by weighing each component raw material by weight percentage, the PBT resin is put into moisture eliminator 120 ℃ of dryings four hours;

B: with each constituent materials: PBT resin, halogen-free flame retardants, silane coupling agent, grafting toughner, oxidation inhibitor, lubricant were put into the high-speed mixer mixing 5-8 minute;

C: open twin screw extruder, processing condition such as the Heating temperature of set device, extruded velocity, rate of feeding, dicing machine rotating speed add forcing machine with mixing material and add alkali free glass fibre simultaneously, and the tie rod pelletizing obtains the finished product;

D: processing condition such as the Heating temperature of setting twin screw extruder, screw speed, rate of feeding:

Temperature is set at: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃; Screw speed: 250-350 rev/min; Feeding: 8-15HZ; Dicing machine rotating speed: 20-25 hertz.

The present invention has following beneficial effect:

The present invention is a kind of glass fibre reinforced halogen-free fire retardant PBT composite material and preparation method thereof.This matrix material can make the fire-retardant index of the not halogen-containing UL94V0 of the reaching level of matrix material of preparation and keep excellent mechanical property, electrical property, processing characteristics and dyeability by adopting novel halogen-free flame-retardant agent and corresponding processing aid, complete processing.This matrix material is applicable to the electronics of outlet, the manufacturing of electric equipment products parts.

Embodiment

Example 1

Each component raw material and auxiliary agent are taken by weighing by weight percentage, wherein, PBT resin 59%, halogen-free flame retardants 18%, silane coupling agent 0.2%, grafting toughner 2%, primary antioxidant 0.2%, auxiliary antioxidant 0.3%, lubricant 0.3%.After high-speed mixer mixes, add extruding pelletization in the twin screw extruder, add alkali free glass fibre from the glass mouth simultaneously, the alkali free glass fibre weight percent is 20%.The temperature of respectively distinguishing of twin screw is set to: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃.

The particle of producing is made test bars by respective standard, carries out every performance detection, draws corresponding data, the sample of observation test simultaneously outward appearance.

Embodiment 2

Each component raw material and auxiliary agent are taken by weighing by weight percentage, wherein, PBT resin 58%, halogen-free flame retardants 18%, silane coupling agent 0.2%, grafting toughner 3%, primary antioxidant 0.2%, auxiliary antioxidant 0.3%, lubricant 0.3%.After high-speed mixer mixes, add extruding pelletization in the twin screw extruder, add alkali free glass fibre from the glass mouth simultaneously, the alkali free glass fibre weight percent is 20%.The temperature of respectively distinguishing of twin screw is set to: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃.

The particle of producing is made test bars by respective standard, carries out every performance detection, draws corresponding data, the sample of observation test simultaneously outward appearance.

Embodiment 3

Each component raw material and auxiliary agent are taken by weighing by weight percentage, wherein, PBT resin 49.9%, halogen-free flame retardants 16%, silane coupling agent 0.3%, grafting toughner 3%, primary antioxidant 0.2%, auxiliary antioxidant 0.3%, lubricant 0.3%.After high-speed mixer mixes, add extruding pelletization in the twin screw extruder, add alkali free glass fibre from the glass mouth simultaneously, the alkali free glass fibre weight percent is 30%.The temperature of respectively distinguishing of twin screw is set to: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃.

The particle of producing is made test bars by respective standard, carries out every performance detection, draws corresponding data, the sample of observation test simultaneously outward appearance.

Embodiment 4

Each component raw material and auxiliary agent are taken by weighing by weight percentage, wherein, PBT resin 48.9%, halogen-free flame retardants 16%, silane coupling agent 0.3%, grafting toughner 4%, primary antioxidant 0.2%, auxiliary antioxidant 0.3%, lubricant 0.3%.After high-speed mixer mixes, add extruding pelletization in the twin screw extruder, add alkali free glass fibre from the glass mouth simultaneously, the alkali free glass fibre weight percent is 30%.The temperature of respectively distinguishing of twin screw is set to: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃.

The particle of producing is made test bars by respective standard, carries out every performance detection, draws corresponding data, the sample of observation test simultaneously outward appearance.

Embodiment 5

Each component raw material and auxiliary agent are taken by weighing by weight percentage, wherein, PBT resin 39.8%, halogen-free flame retardants 15%, silane coupling agent 0.4%, grafting toughner 4%, primary antioxidant 0.2%, auxiliary antioxidant 0.3%, lubricant 0.3%.After high-speed mixer mixes, add extruding pelletization in the twin screw extruder, add alkali free glass fibre from the glass mouth simultaneously, the alkali free glass fibre weight percent is 40%.The temperature of respectively distinguishing of twin screw is set to: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃.

The particle of producing is made test bars by respective standard, carries out every performance detection, draws corresponding data, the sample of observation test simultaneously outward appearance.

Performance test:

Its performance perameter is measured according to table 1:

Table 1

Project	Standard
		Tensile strength (Mpa)	GB/T1040
Elongation at break (%)	GB/T1040
		Flexural strength (Mpa)	GB9341
Modulus in flexure (Mpa)	GB9341
		Socle girder unnotched impact strength (KJ/m 2)	GB/1843
Heat-drawn wire (℃) 1.82Mpa	GB/1634
		Molding shrinkage (%)	GB/T15585
Oxygen index	GB/T2406
		Flame retardant resistance	UL94V level flammability test method
Volume resistance Ω cm	GB/T1410
		Dielectric strength MV/m	GB/T1408
Halogen (Br, Cl) content	IEC61189-2

Example formulations and material property see Table 2:

Table 2

By embodiment advantage of the present invention as can be seen: this product when reaching the UL94V0 flame retardant rating, has kept glass fibre to strengthen intensity, the electrical property of PBT under not halogen-containing prerequisite.Use the combustion-proof glass fiber of halogen flame to strengthen PBT relatively, toughness also has a certain upgrade.

Comparison by embodiment 1-4 can learn that the consumption of halogen-free flame retardants can suitable minimizing also can reach the UL94V0 flame retardant rating with the increase of glass fiber content; Performances such as the rigidity of product, intensity, toughness, molding shrinkage increase with the increase of content of glass fiber, meet the performance rule that glass fibre strengthens the PBT material, diminish but content of glass fiber reaches 30% later increasing degree; Grafting toughner be added in the same glass fibre content time toughness of material improved.From over-all properties, content of glass fiber is 30%, the halogen-free flameproof agent content is 16%, grafting toughner content is 4% o'clock every balancing performance of this product, is comparatively ideal behaviour in service.

Among the present invention, glass fibre is to have high-intensity material, by twin screw extruder the shearing of glass fibre is made it to become the fiber fines bundle, coupled action and the PBT resin by silane coupling agent becomes a main body then, thereby reaches the purpose that strengthens the PBT resin property.Grafting toughner and halogen-free flame retardants all be by with PBT resin functional group reactions, be bonded on the PBT molecular chain, thereby improve two alternate consistencies, reach toughness reinforcing and do not influence the purpose of resin property.In order to reach the purpose of auxiliary agent and reaction resin mixture, adopted the expressing technique of higher extrusion temperature, low extruded velocity especially.

More than a kind of glass fibre reinforced halogen-free fire retardant PBT composite material provided by the present invention and preparation method thereof is described in detail, used specific case herein principle of the present invention and embodiment are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (7)

1, a kind of glass fibre reinforced halogen-free fire retardant PBT composite material is characterized in that, its composition is (%) by weight ratio:

Polybutylene terephthalate 40-60%;

Halogen-free flame retardants 15-18%;

The fine 20-40% of non-alkali glass;

Silane coupling agent 0.2-0.5%;

Grafting toughner 2-4%;

Primary antioxidant 0.1-0.3%;

Auxiliary antioxidant 0.2-0.5%;

Lubricant 0.2-0.5%.

2, glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that: described polybutylene terephthalate relative density 1.31-1.34 gram/cubic centimetre.

3, glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that, described grafting toughner is the POE grafts.

4, glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that: described primary antioxidant is a pentaerythritol tetrathioglycollate, antioxidant 1010.

5, glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that: described auxiliary antioxidant is a GW-540, oxidation inhibitor 168.

6, glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that: described lubricant is N, the N-ethylenebisstearamide.

7, a kind of preparation method of glass fibre reinforced halogen-free fire retardant PBT composite material as claimed in claim 1 is characterized in that, comprises step:

A: take by weighing each component raw material by weight percentage, the PBT resin is put into moisture eliminator 120 ℃ of dryings four hours;

B: with each constituent materials: PBT resin, halogen-free flame retardants, silane coupling agent, grafting toughner, oxidation inhibitor, lubricant were put into the high-speed mixer mixing 5-8 minute;

C: open twin screw extruder, processing condition such as the Heating temperature of set device, extruded velocity, rate of feeding, dicing machine rotating speed add forcing machine with mixing material and add alkali free glass fibre simultaneously, and the tie rod pelletizing obtains the finished product;

D: processing condition such as the Heating temperature of setting twin screw extruder, screw speed, rate of feeding:

Temperature is set at: a district 210-220 ℃, and two district 220-230 ℃, three district 230-240 ℃, four district 230-240 ℃, five district 235-245 ℃, six district 230-240 ℃, die head temperature 225-235 ℃; Screw speed: 250-350 rev/min; Feeding: 8-15HZ; Dicing machine rotating speed: 20-25 hertz.