CN103465389B - The resistant to elevated temperatures PBT composite of refrigerant and preparation method and application - Google Patents

Abstract

The present invention relates to PBT composite and the preparation method and application of refrigerant resistance to elevated temperatures, carry out fusion intercalation with 2 ~ 6 weight portion hydrophobic nano imvites in every 100 weight portion PBT and be obtained by reacting intermediate; By mass percentage the intermediate of 59.4% ~ 69.4%, the antioxidant of 0.3%, the end carboxyl end-capping reagent of 0.3% and 30% ~ 40% alkali-free glass fibre are mixed, mixture is blended by double screw extruder, reaction extruding pelletization obtains described PBT composite, each section of reaction temperature is 220 ~ 260 DEG C, screw speed 300 ~ 400 revs/min, the present invention can not produce a large amount of free carboxyl groups at shear history, the various performance requirements of the motor coil skeleton of compressor of air conditioner can be met, there is outstanding refrigerant, resistance to elevated temperatures.

Description

The resistant to elevated temperatures PBT composite of refrigerant and preparation method and application

[technical field]

The present invention relates to PBT composite and preparation method and application, be specifically related to PBT composite and the preparation method and application with refrigerant resistance to elevated temperatures.

[background technology]

Air-conditioning and our daily life closely bound up, today, the owning amount of our Domestic Air-condition was minimum also more than 1,000,000,000, and have the air-conditioning of more than ten million platform to need to update every year, every year output of domestic (containing individual proprietorship, joint venture) is all more than 8,000 ten thousand simultaneously, we know that each air-conditioning needs a compressor motor, the effect of compressor motor is: circulating refrigerant (freon, dichlorodifluoromethane), oil impel heat exchange.Have motor coil in the motor of compressor, have coil rack in coil, skeleton is formed by resin insulator material injection.

That generally acknowledges both at home and abroad is applied in compressor motor resin insulator material and must meets: 1) part for insulating material is for being insoluble to refrigerant, oil (refrigerant, oiliness); 2), when rushing magnetic, the thin-walled position of skeleton is constantly split (magnetize intensity); 3) the thin-walled position (the thin-walled mobility of material) of skeleton is filled into fully.

Along with air-conditioning technical is to energy-conserving and environment-protective future development, the electric current standard of compressor motor changes to DC frequency-changing (DC) standard by exchanging (AC) standard, the spiral mode of coil is changed to concentrated volume by a point yardage roll, the transformation of standard drastically increases the effective power of compressor motor, reduce energy consumption, be embodied in the strength ratio that magnetizes that compressor motor coil produces when magnetizing to exchange standard and reduce more than 30% simultaneously, the resin insulator material so passing by always to continue to use is fiberglass reinforced 30%LCP(liquid crystal polymer), fiberglass reinforced 30%PPS(polyphenylene sulfide), LCP as everybody knows, PPS material belongs to special engineering plastics, unit price is very expensive, at present, due to the transformation of compressor motor standard, if re-use LCP, PPS material just seems that performance is superfluous, our country enforced or introduces air-conditioning DC frequency-changing standard or technology from 2010 simultaneously, eliminate original interchange standard.

Present trans-corporation is for the transformation of compressor motor standard, competitively developing the refrigerant of excellent cost performance high temperature resistant enhancing PBT(polybutylene terephthalate (PBT)) composite is used for the insulating material of motor coil skeleton, and the domestic bibliographical information not yet having the high temperature resistant enhancing PBT composite of the refrigerant being specifically designed to compressor of air conditioner motor coil skeleton at present.As domestic patent application CN103013068A discloses a kind of glass fiber reinforced PBT resin composition of tool refrigerant Precipitation Characteristics, but only limiting is applied on the muffler product of refrigerator, compressor of air conditioner, also do not possess and be applied on the motor coil skeleton of compressor of air conditioner, reason is that this application material can't meet motor coil skeleton xanthochromia ageing properties required under high-temperature heating condition; But the conventional PBT of enhancing has a large amount of low molecule under heating status or gas molecules is separated out or volatilization, is easy to be dissolved in refrigerant (freon, dichlorodifluoromethane), the refrigerator pipes of compressor can be caused to block, cause compressor cooling effect malfunctioning.

Three sections of imported materials are only had to meet the performance requirement of the insulating material of compressor of air conditioner motor coil skeleton on the market at present, the 330LC of Polyplastics, the 1101G-30 of toray, the SK605 of Dupont respectively, home brands are almost blank, heavy dependence import.Application documents disclosed in Toray Fiber Research Institute (China) Co., Ltd., publication No. CN101768336A, disclose a kind of polyester/phyllosilicate nano-composite material and production method thereof, this application is improved for the melt intercalated method of polyester and phyllosilicate.

Phyllosilicate is wherein exactly the main component of nano imvite, and the phyllosilicate crystal be made up of two-layer Si-O tetrahedron and one deck Al-O octahedron, containing cation mainly sodium ion in layer, magnesium ion, calcium ion, next has potassium ion, lithium ion etc.Nano imvite changes layer inner hydrophilic layer into hydrophobic layer after organically-modified, thus makes high polymer and imvite have better interface compatibility.The additive of macromolecular material industry as nanometer polymer macromolecular material can be widely used in, improve shock resistance, antifatigue, dimensional stability and gas barrier property etc., thus play the effect strengthening polymer comprehensive physical performance, improve materiel machining performance simultaneously.

The compound of polyester and imvite is generally realized by intercalation, intercalation compounding is divided into polymerization graft process and melt intercalated method, polymerization graft process is first disperseed by polyester monocase, intercalation enters between the lamella of imvite, then in-situ polymerization, utilize the amount of heat of releasing during polymerization, overcome the Coulomb force between silicate lamella, thus make its compound.Fusion intercalation rule is composite in response type double screw extruder by polyester and layered silicate material, under the effect of Strong shear power, polymer molecular chain is inserted between montmorillonite layer, thus obtains the compound of polyester/imvite.

But, it is to be noted that nano imvite PBT extrudes through second melting plasticizing and can produce a large amount of end carboxyl (-COOH), this end carboxyl (-COOH) dissociation can go out H+ ion and allows refrigerant (freon, dichlorodifluoromethane) aobvious acid, can corrode copper refrigerator pipes, and the PBT material in this application do not have the performance of refrigerant.

[summary of the invention]

In order to solve above-mentioned deficiency of the prior art and defect, the invention provides one and there are refrigerant, resistant to elevated temperatures PBT composite and preparation method and application.

For achieving the above object, first invent the preparation method of the resistant to elevated temperatures PBT composite of a kind of refrigerant, comprise the following steps:

Carry out fusion intercalation with 2 ~ 6 weight portion hydrophobic nano imvites in every 100 weight portion PBT and be obtained by reacting intermediate;

By mass percentage the intermediate of 59.4% ~ 69.4%, the antioxidant of 0.3%, the end carboxyl end-capping reagent of 0.3% and 30% ~ 40% alkali-free glass fibre are mixed, mixture is blended by double screw extruder, reaction extruding pelletization obtains described PBT composite, each section of reaction temperature is 220 ~ 260 DEG C, screw speed 300 ~ 400 revs/min.

Preferably, hydrophobic nano imvite is prepared by following steps:

Add 1 ~ 10 weight portion in the nano imvite of every 100 weight portion particle diameter 10 ~ 100nm and contain the quaternary cationics of hydrophobic group carbon number 12 ~ 18 after mixing, successively through suction filtration, washing, drying, grind, sieve and de-crystallization water step.The particle diameter of nano imvite is preferably 30 ~ 50nm.

Nano imvite has the following advantages after surface modification (hydrophobicity):

1) can adjust the interlamellar spacing size of nano imvite, the size Control of interlamellar spacing puts to death the diameter in PBT strand.In general, as long as the interlamellar spacing of nano imvite equals or slightly larger than the diameter of PBT strand, so just easily there is fusion intercalation reaction between nano imvite and PBT, define a lot of bar to be similar to the network structure of pearl necklace (wherein " pearl " is nano imvite, " necklace " is PBT strand), nano imvite in network structure has just become energy absorption point, improve the notch impact strength (toughness) of PBT, the ordered linear arrangement of PBT strand simultaneously also becomes network lineup, such network lineup also improves the bending modulus (rigidity) of PBT, otherwise, if the interlamellar spacing of nano imvite is less than the diameter of PBT strand, so just be difficult between nano imvite and PBT fusion intercalation reaction occurs, bulk deposition and gel will be there is in nano imvite in PBT melt, the network structure being similar to pearl necklace can not be formed, the toughness of PBT and rigidity is caused to decline,

2) improve the compatibility between nano imvite and PBT, improve its dispersiveness in PBT melt;

3) after nano imvite and PBT strand define the network structure being similar to pearl necklace, the probability of the molecule generation tunnel-effect in PBT compound system will be reduced, improve the barrier property of PBT compound system to Small molecular or gas molecule, the PBT composite of the application is made to have possessed the feature under the state of high-temperature heating with low volatility, this feature is conducive to the precipitation or the volatilization that reduce PBT composite low molecule or gas molecules under heating status, reduce these low molecule or gas molecules is dissolved in refrigerant (freon, dichlorodifluoromethane) in, thus make PBT composite have the feature of refrigerant, by contrast, the conventional PBT of enhancing under heating status, have a large amount of low molecule or gas molecules is separated out or volatilization, is easy to be dissolved in refrigerant (freon, dichlorodifluoromethane), the refrigerator pipes of compressor can be caused to block, cause compressor cooling effect malfunctioning.

Described fusion intercalation reaction is preferably made up of following steps:

1) described PBT resin is dried 4 ~ 5 hours in convection oven at 100 ~ 120 DEG C;

2) the hydrophobic nano imvite adding 2 ~ 6 weight portions in the every 100 weight portion PBT resin after oven dry is mixed;

3) mixture is by the granulation of response type parallel dual-screw extruding machine blending extrusion, and each section of temperature range of double screw extruder: 220 ~ 260 DEG C, screw speed: 300 ~ 400 revs/min, finally obtains described intermediate.

The inherent viscosity of described PBT is 0.7 ~ 1.3dl/g, melt index MFI is 9 ~ 70g/10min.Further, inherent viscosity is 1.0dl/g, melt index MFI is 20 ~ 23g/10min.

Described antioxidant is phosphite antioxidant.Mainly contain pentaerythrite diphosphite two (2,4-di-tert-butyl-phenyl) ester, pentaerythrite diphosphite two (3,5-di-tert-butyl-phenyl) ester; be preferably pentaerythrite diphosphite two (3,5-di-tert-butyl-phenyl) ester; fusing point 237 DEG C; can under 300 DEG C of melt temperatures, protect PBT that the melt viscosity of xanthochromia and stable PBT does not occur, and the pentaerythritol esters of routine (phenols) antioxidant, amine antioxidants all have and protect PBT that the feature of the melt viscosity of xanthochromia and stable PBT does not occur under 300 DEG C of melt temperatures.

Described alkali-free glass fibre has conventional winding yarn and direct yarn, length 3mm ~ flat alkali-free glass fibre of 4.5mm high-modulus (width 11 ~ 13 μm), is preferably the flat alkali-free glass fibre of length 4.5mm high-modulus, width 11 μm.It is to be noted that alkali-free glass fibre that routine selects normally sprays silk by quartz sand melt by circular hole spinneret, therefore the fiber obtained is circular, instead of flat pattern, in the injection molding process of reality, Strong shear can be produced owing to changing flow direction during flat cast gate (mould gate of compressor motor coil rack is designed to flat cast gate by performance requirement) of circular glass fiber by mould, this Strong shear can cause a large amount of circular glass fiber generation phenomenon of ruptures, cause the effective length of glass fibre in injecting products lower than the ratio of 0.8mm significantly improve (injecting products by Muffle furnace by 600 DEG C of temperature calcinations after 3 hours, rough Statistics effective length accounts for glass fibre total amount up to 46% lower than the glass fibre of 0.8mm), therefore the bending modulus (rigidity) of injecting products can obviously decline, owing to there is refrigerant resistant to elevated temperatures enhancing PBT composite for alternative enhancing LCP or enhancing PPS material, therefore the rigidity strengthening PBT composite is very important index.The flat alkali-free glass fibre of length 4.5mm high-modulus (width 11 μm) is selected just to solve this crux very well to this application, the domestic technology production length 3mm ~ flat alkali-free glass fibre of 4.5mm high-modulus only having Taishan glass fiber Ltd to introduce PPG company of the U.S. at present, width 11 ~ 13 μm.

Described end carboxyl end-capping reagent is epoxy resin, the ethylene-acrylic acid-glycidyl ester copolymer containing epoxy resin group, haplotype carbodiimides.Be preferably haplotype carbodiimides; It is to be noted that nano imvite PBT extrudes through second melting plasticizing and can produce a large amount of end carboxyl (-COOH), this end carboxyl (-COOH) dissociation can go out H+ ion and allows refrigerant (freon, dichlorodifluoromethane) aobvious acid, copper refrigerator pipes can be corroded, therefore must carry out end carboxyl end-blocking to nano imvite PBT.Select response type end-capping reagent--haplotype carbodiimides is optimal selection, and the interpolation of haplotype carbodiimides can not affect the overall performance strengthening PBT composite.

Described quaternary cationics is octadecyl quaternary ammonium salt or cetyl quaternary ammonium salt, is preferably octadecyl quaternary ammonium salt.

Silane coupler can also be added in described hydrophobic nano imvite.After with the addition of described coupling agent, hydrophobic nano imvite and the glass fibre had in refrigerant resistant to elevated temperatures enhancing PBT composite can be made to have better compatibility.

The present invention also comprises a kind of PBT composite prepared by above preparation method, and under ASTM standard test condition, content of carboxyl end group only has 8.7 ~ 9.3mmol/g.

This PBT composite may be used for the motor coil skeleton making compressor of air conditioner.

[detailed description of the invention]

One, the preparation of hydrophobic nano imvite:

1) be that the nano imvite 4Kg appropriate amount of deionized water of 30 ~ 50nm is diluted to uniform slurries by average grain diameter, be warming up to 90 DEG C, 0.2Kg octadecyl quaternary ammonium salt is slowly joined in slurries, suitably can also add silane coupler as required, stir and to carry out three suction filtrations and washing, drying after 90 minutes, grind and sieve, the intermediate product of surface-modified nano imvite can be obtained;

2) intermediate product of surface-modified nano imvite is put into vacuum and turn pot, be warming up to 105 DEG C, vacuum is 0.02MPa, takes out that to carry out vacuum packaging for subsequent use after dry 240 minutes, namely the imvite of surface-treated hydrophobic nano is obtained, namely described hydrophobic nano imvite.

Two, nano imvite PBT(intermediate) preparation

In the molten state, PBT(continuous phase) and nano imvite (decentralized photo) two-phase system, PBT strand is just easily punctured between the lamella of nano imvite, thus there is fusion intercalation reaction, define a lot of bar to be similar to the Ms's ornament-pearl necklace seen in our daily life (wherein pearl class is similar to nano imvite, necklace is similar to PBT strand) network structure, if add three components in two-phase system, particularly there is the inorganic constituents of draw ratio (such as: glass fibre, talcum powder, wollastonite etc.), with regard to easy to PBT and nano imvite System forming blocking effect, the network structure of ring PBT two-phase system can be broken, therefore to prepare and there is the resistant to elevated temperatures enhancing PBT composite of refrigerant must first prepare nano imvite PBT, nano imvite PBT is not yet industrialization at home, be difficult to directly buying on the market arrive, (particularly Japan abroad, Germany, the U.S.) realized suitability for industrialized production in 2010 with regard to adopting the method for monomer polycondensation reaction (in-situ polymerization or intercalation polymeric), but current licensing outlet not yet at home, therefore the application adopts the method for fusion intercalation to prepare nano imvite PBT by response type parallel dual-screw extruding machine.

1) described 20KgPBT resin is dried 4 hours in convection oven at 120 DEG C;

2) PBT resin after being dried by 20Kg mixes rear releasing in 7 minutes with the imvite of 0.8Kg hydrophobic nano by homogenizer high-speed stirred, and the feeding trough simultaneously pouring response type parallel dual-screw extruding machine into is for subsequent use;

3) mixture is by the granulation of response type parallel dual-screw extruding machine blending extrusion, and each section of temperature of double screw extruder is set as 220 ~ 260 DEG C, screw speed: 300 revs/min, finally obtains described nano imvite PBT(intermediate), package spare.

Three, there is the preparation of the resistant to elevated temperatures enhancing PBT composite of refrigerant

The proportioning following (see table one) of the percentage by weight of embodiment 1-3 and comparative example 1-2:

Table one

Concrete steps are as follows:

1) described intermediate, PBT resin are dried 4 hours in convection oven at 120 DEG C;

2) intermediate after drying, PBT resin, hydrophobic nano imvite, pentaerythrite diphosphite two (3,5-di-tert-butyl-phenyl) ester, haplotype carbodiimides, the flat alkali-free glass fibre of length 4.5mm high-modulus are mixed by the percentage by weight shown in table one, by the parallel dual-screw extruding machine blending extrusion granulation of routine, 5 finished products can be obtained.Standard testing batten is injection molded into by injection machine after 5 finished products are dried 4 hours in convection oven at 120 DEG C;

Each section of temperature of the parallel dual-screw extruding machine of described routine is followed successively by: 250 DEG C, 245 DEG C, 240 DEG C, 235 DEG C, 230 DEG C, 225 DEG C, 230 DEG C, 235 DEG C, 240 DEG C, 245 DEG C, screw speed: 300r/min;

Each section of temperature of described injection machine is followed successively by 225 DEG C, 230 DEG C, 235 DEG C, 235 DEG C.

By the embodiment 1-3 that obtains and comparative example 1-2 batten according to its mechanical property of ASTM standard testing and content of carboxyl end group, test according to the compatibility of the standard test PBT decided at the higher level but not officially announced of air conditioner compressed engineer's workshop of Japan and refrigerant, heat-proof aging, test result is in table two simultaneously:

Table two

Remarks: according to the performance test requirement of the air conditioner compressed engineer's workshop of day system to motor coil framework material, injection-molded item needs test refrigerant and PBT material compatibility and heat-proof aging to test (test result is provided by Zhi factory), and concrete standard decided at the higher level but not officially announced is as follows:

* the compatibility test of refrigerant and PBT material: under refrigerant pressurized in autoclave is in liquid situation, goods are immersed in refrigerant, the continuous dipping time: 120 days, observe the turbidity of refrigerant liquid, if liquid generation turbid phenomenon or have granule to separate out, be judged to be defective.

* heat-proof aging test: goods are placed on 150 DEG C, and (relative humidity: 50%) in heat aging test chamber, places 144 hours continuously, observes the Yellowing of goods, if goods jaundice occur or seriously turn to be yellow, all judges defective.

Can draw from the test result of table two:

1) embodiment 2 ~ 3 meets the material performance requirement of compressor motor coil rack, but because the power of compressor motor is different, size and the wall thickness of coil rack differ greatly, therefore consider from the toughness of coil rack and the balance of rigidity, embodiment 2 is suitable for making 1.5 power (containing 1.5 power) compressor motor coil rack below, and embodiment 3 is suitable for the compressor motor coil rack of more than making 1.5 power;

2) embodiment 1 can not meet the performance requirement of compressor motor coil rack due to the overall mechanical property of material, therefore the air conditioner compressed engineer's workshop of day system does not carry out the compatibility test of refrigerant and PBT material to embodiment 1, heat-proof aging tests binomial key performance and test, and directly eliminates.

3) can draw from the test result of comparative example 1, have in the formula system of the resistant to elevated temperatures enhancing PBT composite of refrigerant according to PBT resin, but not nano imvite PBT, so the result of the compatibility test of refrigerant and PBT is judged as defective, the result of heat-proof aging test is micro-Huang, find that content of carboxyl end group exceeds nearly one times than the content of carboxyl end group of embodiment 1 ~ 3 simultaneously, this just demonstrates the feature that foregoing nano imvite PBT has low precipitation refrigerant, and the feature of the not low precipitation refrigerant of conventional PBT resin.

4) can draw from the test result of comparative example 2, have in the formula system of refrigerant resistant to elevated temperatures enhancing PBT composite directly mixed with nano imvite according to PBT resin, but not nano imvite PBT, so the result of the compatibility test of refrigerant and PBT is judged as defective, the result of heat-proof aging test is micro-Huang, content of carboxyl end group exceeds nearly one times than the content of carboxyl end group of embodiment 1 ~ 3, overall mechanical property is not as embodiment 2 simultaneously, this just demonstrates in the molten state foregoing, PBT(continuous phase) and nano imvite (decentralized photo) two-phase system, PBT strand is just easily punctured between the lamella of nano imvite, thus there is fusion intercalation reaction, define the network structure that a lot of bar is similar to pearl necklace, if add three components in two-phase system, particularly there is the inorganic constituents of draw ratio (such as: glass fibre, talcum powder, wollastonite etc.), with regard to easy to PBT and nano imvite System forming blocking effect, the network structure of ring PBT two-phase system can be broken, cause overall mechanical property on the low side, do not possess the feature of the low precipitation refrigerant of nano imvite PBT simultaneously yet.

In sum, embodiment 2 ~ 3 is the material performance requirement meeting compressor of air conditioner motor coil skeleton, can substitute imported material.

In order to verify that embodiment 2 ~ 3 and import brand (SK605 of the 330LC of Polyplastics, the 1101G-30 of toray, Dupont) have suitable performance further, the applicant has done parallel test together with the air conditioner compressed engineer's workshop of day system, and experimental test the results are shown in Table three:

Table three

Attention: be with the remarks item of the test event of No. * with table two.

Can draw from the test result of the parallel test of table three, embodiment 2 ~ 3 is suitable with the performance of imported material, can substitute the material of Polyplastics 330LC, toray 1101G-30 that current compressor of air conditioner motor coil skeleton adopts, Dupont SK605 completely.

Claims (8)

1. a preparation method for the resistant to elevated temperatures PBT composite of refrigerant, is characterized in that comprising the following steps: carry out fusion intercalation with 2 ~ 6 weight portion hydrophobic nano imvites in every 100 weight portion PBT and be obtained by reacting intermediate;

By mass percentage the intermediate of 59.4% ~ 69.4%, the phosphite antioxidant of 0.3%, the haplotype carbodiimides of 0.3% and 30% ~ 40% alkali-free glass fibre are mixed, mixture is blended by double screw extruder, reaction extruding pelletization obtains described PBT composite, each section of reaction temperature is 220 ~ 260 DEG C, screw speed 300 ~ 400 revs/min.

2. preparation method as claimed in claim 1, characterized by further comprising the preparation process of hydrophobic nano imvite:

Add 1 ~ 10 weight portion in the nano imvite of every 100 weight portion particle diameter 10 ~ 100nm and contain the quaternary cationics of hydrophobic group carbon number 12 ~ 18 after mixing, successively through suction filtration, washing, drying, grind, sieve and de-crystallization water step.

3. preparation method as claimed in claim 2, is characterized in that the particle diameter of nano imvite is 30 ~ 50nm.

4. preparation method as claimed in claim 1, is characterized in that described fusion intercalation reactions steps is as follows:

1) described PBT resin is dried 4 ~ 5 hours in convection oven at 100 ~ 120 DEG C;

2) the hydrophobic nano imvite adding 2 ~ 6 weight portions in the every 100 weight portion PBT resin after oven dry is mixed;

3) mixture is by the granulation of response type parallel dual-screw extruding machine blending extrusion, and each section of temperature range of double screw extruder: 220 ~ 260 DEG C, screw speed: 300 ~ 400 revs/min, finally obtains described intermediate.

5. preparation method as claimed in claim 1, is characterized in that the inherent viscosity of described PBT be 0.7 ~ 1.3dl/g, melt index MFI is 9 ~ 70g/10min.

6. preparation method as claimed in claim 1, is characterized in that described alkali-free glass fibre is the flat alkali-free glass fibre of high-modulus of length 3mm ~ 4.5mm, width 11 ~ 13 μm.

7., by a PBT composite prepared by the arbitrary preparation method of claim 1 ~ 6, it is characterized in that content of carboxyl end group is 8.7 ~ 9.3mmol/g under ASTM standard test condition.

8. an application for PBT composite according to claim 7, is characterized in that the motor coil skeleton for making compressor of air conditioner.