CN100365061C - Polyformamine treatment thermal stabilizing method - Google Patents
Polyformamine treatment thermal stabilizing method Download PDFInfo
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- CN100365061C CN100365061C CNB2006100208857A CN200610020885A CN100365061C CN 100365061 C CN100365061 C CN 100365061C CN B2006100208857 A CNB2006100208857 A CN B2006100208857A CN 200610020885 A CN200610020885 A CN 200610020885A CN 100365061 C CN100365061 C CN 100365061C
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Abstract
This invention relates to a thermal-stabilizing method for paraformaldehyde-amine including: mixing paraformaldehyde with the melt index 9~27g/10min of 100 amounts by weight, antioxidants 0.1~0.5 of amounts by weight, formic acid absorber of 367 amounts by weight, lubricant of 367 amounts by weight, amine compounds of 0.05 amounts by weight and water of 1-10 amounts by weight, then melt-mixing the mixture in the exhaust twin-screw extruder, extruding the materials in the form of granulation and the temperature of the barrel extruder is set at 140~220 deg. C, screw speed is set at 30 - 180 rpm, the materials are dried for 3~5h at 80-90deg.C or mixing the paraformaldehyde, antioxidants, formic acid absorber and lubricant, then extruding the materials in the form of granulation, feeding amide solution in the feeding throat of the extruder at the same time and the melt temperature, screw speed, drying process are the same with the former.
Description
Technical field
The present invention relates to a kind of method of polyformamine treatment thermal stabilizing, belong to polymer processing field.
Background technology
Polyoxymethylene (POM) is with [CH
2-O-] be main chain, no branching, high-melting-point, high-density, high crystallization thermoplastic engineering plastics, have very high strength and stiffness, outstanding creep resistant, resistance to fatigue, intrinsic oilness, wearability and chemical proofing etc., be near the kind of metal in the engineering plastics, can be in order to non-ferrous metal and alloy products such as Alloy instead of Copper, aluminium, zinc, be widely used in fields such as electric, automobile, light industry, machinery, chemical industry, building materials.
Because POM specific molecule structure, its thermostability is relatively poor, thereby the thermostabilization of POM is most important, the most basic gordian technique in its synthetic or processed and applied.Yu Jian etc., engineering plastics are used, and 2001,29 (4), 28-30 has described under the heat and oxygen effect of POM in the melt-processed process, and in a single day its molecule produces free radical, and chain rupture will take place, and successive piptonychia aldehyde reaction takes place then.And formaldehyde and will promote thermal decomposition process by the micro-formic acid that oxidation of formaldehyde generates quickens the piptonychia aldehyde reaction greatly, until the macromolecular chain decomposition of POM totally.Chinese patent CN1196073A discloses existing P OM resin can not satisfy the thermostability requirement, on mould, produce dirt settling, and make moulding product surface deterioration, its reason be the POM resin when moulding since the trace oxygen and oxygenolysis, increased the formaldehyde amount of decomposing, because the formaldehyde that produces further becomes formic acid, thereby has promoted the decomposition of POM resin backbone.In the synthesizing polyoxymethylene process, because the water of trace, formic acid, methyl alcohol etc. cause chain transfer in the system, can make POM at the unsettled terminal hydroxy group of the terminal generation of macromole, also be difficult to remove fully by the fusion aftertreatment.Louis's acids initiator of using always in the polymerization, as: boron trifluoride ethyl ether complex remains in the system, and its activity also can cause the degraded and the fracture of POM molecule.Japanese Patent JP54-107972 and NL-A6812966 reported the employing ammonia soln to the POM raw material carry out long time treatment or 100-200 ℃, under high pressure handle, this is not only consuming time, and need specific installation, also increased POM cleaning, purification, exsiccant operation.Therefore, adopt suitable method and reagent that POM is carried out stabilization treatment and just seem very important improving its thermostability.
Summary of the invention
The objective of the invention is to provide a kind of method of polyoxymethylene thermostabilization at the deficiencies in the prior art.Be characterized in according to POM molecular structure characteristics and the decomposition mechanism under effects such as heat, oxygen, acid, POM fusion last handling process is combined with the amine processing, decomposition by the chemical property of aminated compounds is further stablized POM exposed terminated groups and its molecule of inhibition reaches better thermostabilization effect.
Purpose of the present invention is realized that by following technical measures wherein said raw material mark is parts by weight except that specified otherwise.
The method of polyformamine treatment thermal stabilizing, the recipe ingredient of described starting raw material is:
100 parts of POM melting index 9～27g/10min
0.1～0.5 part in oxidation inhibitor
Aminated compounds 0.05-5 part
0.05～0.5 part in formic acid absorption agent
0.05～0.5 part of lubricant
1～10 part in water
Wherein, oxidation inhibitor is four [β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester, two [3-(the 3-tertiary butyl-5-methyl-4-hydroxy phenyl) propionic acid triethylene Glycol esters, two [3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] 1,6-hexylene glycol ester or N, among the N '-hexylidene two (3,5-di-t-butyl-4-hydroxyl-hydrocinnamamide) any.
The aminated compounds treatment agent is any in ammoniacal liquor, triethylamine, tri-n-butylamine, the trolamine.
The formic acid absorption agent is any in magnesium oxide, magnesium hydroxide, Calucium Silicate powder, neurosin, the lime carbonate.
Lubricant is any in Zerol, two hard esteramides, the tetramethylolmethane tristearate.
POM amine is handled the method for thermostabilization
The following two kinds of methods of main employing are carried out amine to POM and are handled.
0.05～5 part of 0.05～0.5 part of 0.05～0.5 part in 0.1～0.5 part in 100 parts of polyoxymethylene, oxidation inhibitor, formic acid absorption agent, lubricant, amine compound and the water of melting index 9～27g/10min are mixed for 1～10 part, adopt exhaust twin screw extruder melting mixing, extruding pelletization, the extruder barrel temperature is 140～220 ℃, screw speed is 30～180 rev/mins, pellet obtains the thermostabilization polyformaldehyde material 80～90 ℃ of dryings 3～5 hours; Or
With 100 parts of the polyoxymethylene of melting index 9～27g/10min, 0.1～0.5 part in oxidation inhibitor, 0.05～0.5 part in formic acid absorption agent, lubricant mixes for 0.05～0.5 part, extruding pelletization in the exhaust twin screw extruder, and the while drips the solution of 1～10 part in 0.05～5 part/water of amine compound at main-machine screw opening for feed place, the extruder barrel temperature is 140～220 ℃, screw speed is 30～180 rev/mins, and pellet obtains the thermostabilization polyformaldehyde material 80～90 ℃ of dryings 3～5 hours.
Amine is handled the POM performance
Fig. 1 amine is handled to be influenced POM (not having other thermally-stabilised auxiliary agent) thermal weight loss rate
Untreated POM thermal weight loss rate is 55.63%, the POM thermal weight loss rate of triethylamine fusion aftertreatment is 43.61%, and the POM thermal weight loss rate of trolamine fusion aftertreatment is 12.2%, this shows, the more untreated thermal weight loss rate of handling through amine of POM reduces, and shows higher thermal stability.
Fig. 2 amine compound kind influences POM (containing other thermally-stabilised auxiliary agent) thermal weight loss rate
Owing to added oxidation inhibitor, the POM that does not add other thermally-stabilised auxiliary agent with Fig. 1 compares, and the thermal weight loss rate all descends significantly.As shown in Figure 2, with the sample contrast of being untreated, it is very little that triethylamine is handled the reduction of POM thermal weight loss rate, to POM thermostabilization DeGrain; Trolamine is handled POM thermal weight loss rate and is obviously reduced, and shows heat stabilization preferably.
Fig. 3 is for handling the thermal weight loss rate contrast of the POM and the POM that is untreated respectively with trolamine
Under the equal conditions, the POM system thermal weight loss rate that adds trolamine is lower, wherein trolamine is handled POM (only containing oxidation inhibitor) even the more untreated POM that contains oxidation inhibitor and trimeric cyanamide (MA) is low, show trolamine not only can play a part in and residual catalyst, impel unstable end group to decompose, also can replace MA fully as POM formaldehyde absorption agent, effectively improve the POM thermal stability.
Fig. 4 trolamine consumption influences POM thermal weight loss rate
As shown in Figure 4, when trolamine consumption during at 0～0.1wt%, increase with the trolamine consumption, POM thermal weight loss rate sharply descends, and tends towards stability gradually subsequently, reaches minimum thermal weight loss rate when 0.2wt% trolamine consumption.Continuing increases its consumption again, and POM thermal weight loss rate rises to some extent.
Fig. 5 trolamine consumption influences POM thermal weight loss speed
As shown in Figure 5, with the increase of heated time, POM thermal weight loss rate increases, and the remainder quality reduces.Compare with the POM that handles without amine, trolamine is handled POM thermal weight loss rate and is descended all slower; Increase with the trolamine consumption, POM thermal weight loss speed reduces gradually, and when the trolamine consumption is 0.2wt%, its thermal weight loss speed descends very slow, and the trolamine consumption of 0.3wt% rises POM thermal weight loss speed to some extent, and excessive trolamine makes POM that alkaline hydrolysis takes place on the contrary.
Fig. 6 POM burst size of methanal
Because at nitrogen (N
2) test and do not have oxygenizement in the environment, the formaldehyde of taking off from main chain after the POM decomposes is all by Na
2SO
3Absorption liquid absorbs, and therefore institute's burst size of methanal of surveying can be in order to reflect the POM thermal stability.As can be seen from Figure 6, it is low to handle the be untreated burst size of methanal of POM of POM through the 0.2wt% trolamine, reduce to 1426ppm and 1652ppm by 2038ppm, show that the POM that handles through an amount of trolamine has thermal stability preferably, it is less at high temperature to decompose chain rupture, has heat stabilization preferably.
Fig. 7 POM balancing torque
As shown in Figure 7, the balancing torque of POM descends with the mixing time increase.To the POM that is untreated, balancing torque is lower, and having to go to the toilet at the 30min of test falls sharply to 1.5Nm, and this moment, its melt index values was 14.7g/10min.Adding 0.2wt% trolamine can significantly improve the balancing torque of POM, and its fall off rate is starkly lower than the POM that is untreated, and its balancing torque value is 2.0Nm in the 30min of test, and corresponding melt index values is 11.3g/10min.Show that in the POM course of processing amine is handled can effectively improve the POM thermostability.
The melting index (MI) of many processing of Fig. 8 POM
The POM sample is extruded 5 times through twin screw extruder, and test is the melting index (MI) and the molecular weight of each time material relatively.As shown in Figure 8, the two initial MI is close, and with the increase of processing number of times, the MI that amine is handled POM is lower than the POM that is untreated, and shows that can make POM slow down molecular weight in the high-temperature fusion course of processing by the amine processing reduces degree, have better heat stabilization with respect to MA.The weight-average molecular weight that calculates the POM of different processing number of times is listed in table 1.
Fig. 9 digestion time is to the influence of POM melting index (MI)
The POM sample behind the aging certain hour, is tested relatively each time material MI and molecular weight in 140 ℃ of Electric heat ovens.As shown in Figure 9, it is close with the initial MI of the POM that is untreated that amine is handled POM, and with the increase of digestion time, the MI increase degree that amine is handled POM is lower than the POM that is untreated.Through thermo-oxidative ageing 7 days, the MI that amine is handled POM and the POM that is untreated increased percentage and is respectively 10.6% and 22.7%, showed that amine is handled can effectively slow down POM molecular weight in long term thermal oxygen aging process and reduce.The weight-average molecular weight that calculates the POM of different digestion times is listed in table 2.
The present invention has following advantage
The present invention be primarily aimed at exist in the copolymerization POM fusion aftertreatment stabilization method owing to remaining initiator, end group are handled the problem that not exclusively influences its thermostability, the preparation method of a kind of thermally stable P OM is provided.By treating processes again to POM fusion aftertreatment, POM fusion aftertreatment is combined with the amine processing, can effectively improve the POM thermostability, be one of key link during POM produces.Amine is handled has following thermostabilization to POM:
1, crosses the neutralizing effect formation stabilized complex of amine and acidic initiator, make initiator inactivation residual among the POM.
2, provide alkaline environment to promote the residual unstable end group hydrolysis of POM to remove, make the further stabilization of POM end group.
3, remove low-molecular materials such as residual formaldehyde, formic acid as formaldehyde, the further absorption of formic acid absorption agent.
4, handle in the POM process at amine, a spot of water mainly contains two aspect effects, and the one, as the dispersing auxiliary of amine treatment agent, be to impel the unstable end group hydrolysis of POM on the other hand.
5, these stabilising method are that amine processing, mixing of materials granulation are merged into an operation by the twin screw extrusion, make amine and POM thorough mixing, reaction in barrel, under high temperature and strong shearing action, and the forcing machine vacuum pumping hardware is more easily overflowed the formaldehyde gas of decomposition, though therefore the treatment time is short, but more thorough, effect is more obvious.
Description of drawings
Fig. 1 amine is handled to be influenced POM (not having other thermally-stabilised auxiliary agent) thermal weight loss rate
Fig. 2 amine compound kind influences POM (containing other thermally-stabilised auxiliary agent) thermal weight loss rate
Fig. 3 trolamine is handled the thermal weight loss rate contrast of the POM and the POM that is untreated
Fig. 4 trolamine consumption influences POM thermal weight loss rate
Fig. 5 trolamine consumption influences POM thermal weight loss speed
Fig. 6 POM burst size of methanal
Fig. 7 POM balancing torque
The melting index (MI) of many processing of Fig. 8 POM
Fig. 9 digestion time is to the influence of POM melting index (MI)
Embodiment
Below by embodiment the present invention is carried out concrete description; be necessary to be pointed out that at this present embodiment only is used for the present invention is further specified; can not be interpreted as limiting the scope of the invention, the person skilled in the art in this field can make some nonessential improvement and adjustment to the present invention according to the content of the invention described above.
POM 10Kg, triethylamine 100g, water 100g, four [β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester 10g, magnesium oxide 5g, two hard esteramides 20g are mixed, adopt exhaust twin screw extruder melting mixing, extruding pelletization.The extruder barrel temperature is 170～220 ℃, and screw speed is 40 rev/mins, and in 90 ℃ of dry 3h.
[3-(the 3-tertiary butyl-5-methyl-4-hydroxy phenyl) propionic acid triethylene Glycol ester 50g, Calucium Silicate powder 30g, tetramethylolmethane tristearate 5g mix with POM 10Kg, trolamine 5g, water 600g, two, adopt exhaust twin screw extruder melting mixing, extruding pelletization.The extruder barrel temperature is 140～190 ℃, and screw speed is 90 rev/mins, and in 80 ℃ of dryings 5 hours.
With POM 10Kg, ammoniacal liquor (27wt%) 1000g, N, N '-hexylidene two (3,5-di-t-butyl-4-hydroxyl-hydrocinnamamide) 50g, lime carbonate 50g, Zerol 10g mix, and adopt exhaust twin screw extruder melting mixing, extruding pelletization.The extruder barrel temperature is 150～220 ℃, and screw speed is 150 rev/mins, and in 90 ℃ of dryings 3 hours.
With POM 10Kg, it is two that [3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] 1,6-hexylene glycol ester 40g, lime carbonate 30g, neurosin 10g mix, extruding pelletization in the exhaust twin screw extruder, drip the n-Butyl Amine 99 aqueous solution (n-Butyl Amine 99 60g, water 300g) simultaneously at main-machine screw opening for feed place.The extruder barrel temperature is 140～220 ℃, and screw speed is 100 rev/mins, and in 85 ℃ of dryings 4 hours.
Comparison example
With POM 10Kg, [3-(the 3-tertiary butyl-5-methyl-4-hydroxy phenyl) propionic acid triethylene Glycol ester 50g, trimeric cyanamide 10g, lime carbonate 30g, tetramethylolmethane tristearate 20g mix extruding pelletization in the exhaust twin screw extruder.The extruder barrel temperature is 140～220 ℃, and screw speed is 100 rev/mins, and in 90 ℃ of dryings 3 hours.
Weight average molecular weight (the M of many processing of table 1POMw)
| The processing number of times | M w | ||
| POM is untreated | Amine is processed POM (no MA) | Amine is processed POM (containing MA) | |
| 1 | 6700 | 67624 | 68383 |
| 2 | 66883 | 67563 | 67852 |
| 3 | 62764 | 67239 | 66902 |
| 4 | 61520 | 67127 | 66902 |
| 5 | 59839 | 66478 | 66383 |
Table 2 ageing time is to POM molecular weight (Mw) impact
| Ageing time (my god) | M w | ||
| POM is untreated | Amine is processed POM (no MA) | Amine is processed POM (containing MA) | |
| 0 | 66766 | 67359 | 67563 |
| 3 | 66010 | 66961 | 67159 |
| 7 | 63030 | 65468 | 65292 |
| 14 | 62303 | 63640 | 63485 |
Claims (3)
1. the method for a polyformamine treatment thermal stabilizing is characterized in that the prescription that adopts is by weight:
100 parts of POM melting index 9-27g/10min
0.1 ~ 0.5 part in oxidation inhibitor
Ammoniacal liquor or aminated compounds 0.05-5 part
0.05 ~ 0.5 part in formic acid absorption agent
0.05 ~ 0.5 part of lubricant
Water 1-10 part
And by the preparation of following processing step and condition:
Polyoxymethylene, oxidation inhibitor, formic acid absorption agent, lubricant, amine compound aqueous solution are mixed, adopt exhaust twin screw extruder melting mixing, extruding pelletization.140～220 ℃ of extruder barrel temperature, screw speed 30-180 rev/min, pellet obtains the thermostabilization polyformaldehyde material at 80 ~ 90 ℃ of drying 3 ~ 5h; Or
Polyoxymethylene, oxidation inhibitor, formic acid absorption agent, mix lubricant is even, and extruding pelletization in the exhaust twin screw extruder drips amine compound aqueous solution simultaneously at main-machine screw 65 opening for feed places.The extruder barrel temperature is 140～220 ℃, and screw speed is 30-180 rev/min, and pellet obtains the thermostabilization polyformaldehyde material at 80 ~ 90 ℃ of drying 3 ~ 5h.
Wherein aminated compounds is any in triethylamine, tri-n-butylamine, the trolamine; The formic acid absorption agent is any in magnesium oxide, Calucium Silicate powder, neurosin, magnesium hydroxide, the lime carbonate.
2. the method for polyformamine treatment thermal stabilizing according to claim 1, it is characterized in that oxidation inhibitor is that four [b-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester, two [3-(the 3-tertiary butyl-5-methyl-4-hydroxy phenyl) propionic acid triethylene Glycol esters, two [3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] 1,6-hexylene glycol ester or N, among the N '-hexylidene two (3,5-di-t-butyl-4-hydroxyl-hydrocinnamamide) any.
3. the method for polyformamine treatment thermal stabilizing according to claim 1 is characterized in that lubricant is any in Zerol, two hard esteramides, the tetramethylolmethane tristearate.
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| CN102501359B (en) * | 2011-09-27 | 2014-05-28 | 深圳市恩欣龙塑胶制品有限公司 | Extrusion molding method for POM (Polyoxymethylene) plate |
| CN104004317B (en) * | 2014-06-09 | 2016-08-17 | 开滦能源化工股份有限公司 | A kind of low VOC polyformaldehyde (POM) material and preparation method thereof |
| JP6329478B2 (en) * | 2014-11-13 | 2018-05-23 | 旭化成株式会社 | Process for producing polyacetal copolymer |
| US11485856B2 (en) | 2017-05-05 | 2022-11-01 | Ticona Llc | Polyoxymethylene polymer composition that is chemical resistant |
| CN107459760B (en) * | 2017-09-21 | 2019-09-27 | 上海中镭新材料科技有限公司 | A kind of polyformaldehyde material and preparation method thereof |
| CN113024988A (en) * | 2021-01-29 | 2021-06-25 | 宁波东洲传动件有限公司 | Special ball joint assembly for automobile steering |
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| CN1569957A (en) * | 2004-04-27 | 2005-01-26 | 四川大学 | Thermal stability metaformaldehyde and its preparation method |
| JP2005220254A (en) * | 2004-02-06 | 2005-08-18 | Toray Ind Inc | Polyoxymethylene resin composition and molded product therefrom |
| CN1730545A (en) * | 2005-08-04 | 2006-02-08 | 云南云天化股份有限公司 | Thermostable metaformaldehyde containing condensate of melamine and formaldehyde, and its preparation method |
| JP2006045489A (en) * | 2004-06-30 | 2006-02-16 | Toray Ind Inc | Polyoxymethylene resin composition |
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Patent Citations (6)
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| CN1103414A (en) * | 1993-08-24 | 1995-06-07 | 泛塑料株式会社 | Polyoxymethylene composition and molded article thereof |
| CN1511876A (en) * | 2002-12-26 | 2004-07-14 | �塑料株式会社 | Poly formaldehyde resin composition |
| JP2005220254A (en) * | 2004-02-06 | 2005-08-18 | Toray Ind Inc | Polyoxymethylene resin composition and molded product therefrom |
| CN1569957A (en) * | 2004-04-27 | 2005-01-26 | 四川大学 | Thermal stability metaformaldehyde and its preparation method |
| JP2006045489A (en) * | 2004-06-30 | 2006-02-16 | Toray Ind Inc | Polyoxymethylene resin composition |
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