Background technology
Polyvalent alcohol is easily oxidized at relatively high temperatures, and its oxidation mechanism is the chain reaction of free radical, and oxidation products comprises hydroperoxide, free radical etc.Polyvalent alcohol antioxidant property when subsequent production polyurethane foam is extremely important, because polyurethane foam can discharge amount of heat in process of production, and foam not easy heat radiation itself, when the energy at foam center position continues higher, polyvalent alcohol just has the possibility of oxidative degradation, easily there is coking when production polyurethane foam in the polyol product that antioxidant property is low, burns the phenomenon of core, can cause fire time serious.Therefore, in polyvalent alcohol, add antioxidant be very important to improve its antioxidant property.
The CN1810880B mixture disclosed by adding antioxidant, benzofuranone and/or hindered amine and hydrazine or hydrazides carrys out the method for stable chain segment polyurethane.
CN1890284A discloses and comes stable polyvalent alcohol or urethane by the hindered phenol anti-oxidants of adding liquid, and can reduce the atomization of polymkeric substance.
CN1976986B discloses a kind of polyhydric alcohol composition, it hindered amine light stabilizer comprising Oxamides UV light absorber and have hindered phenol structure, can improve the stability of polyvalent alcohol.
CN101128529A discloses the stabilization method of the resistance to thermooxidizing of a kind of polyvalent alcohol or polyurethane composition, which are added at least one there is the hindered amine light stabilizer of hindered phenol structure and/or there is the phosphorous acid calcium salt of hindered phenol structure, thus improve the stability of polyvalent alcohol or polyurethane composition.
The present invention finds, adds the antioxidant in polyvalent alcohol to, comprises hindered phenol structure and monothioester structure in its component simultaneously, has excellent antioxidant property.
Summary of the invention
First object of the present invention is to provide a kind of polyhydric alcohol composition, and this polyhydric alcohol composition comprises the antioxidant containing monothioester structure, and this antioxidant and the composite use of phenol antioxidant, can strengthen the thermostability of polyvalent alcohol.
The technical scheme adopted is:
A kind of polyhydric alcohol composition, comprises the auxiliary antioxidant of the following general formula of polyvalent alcohol, hindered phenol anti-oxidants and at least one:
Wherein, R is the alkyl of 1-24 carbon atom.
As preferred scheme, described alkyl is straight chain or branched-chain alkyl, be preferably methyl, ethyl, n-propyl, sec.-propyl, normal-butyl, isobutyl-, sec-butyl, the tertiary butyl, n-pentyl, isopentyl, base just, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, positive decyl, undecyl, dodecyl, tridecyl, n-tetradecane base, pentadecyl, n-hexadecyl, n-heptadecane base, Octadecane base, NSC 77136 base, 2-mono-ethyl-butyl, 1-methyl amyl, 1, 3-dimethylbutyl, 1, 1, 3, 3-tetramethyl butyl, 1-methyl base, different heptyl, 1-methylheptyl, 1, 1, 3-trimethylammonium base.
Be tetramethylolmethane four (3-lauryl thiopropionate) for most preferred auxiliary antioxidant of the present invention.
Be main anti-oxidant for hindered phenol anti-oxidants of the present invention, its selection does not have special restriction, as preferred embodiments of the present invention, main anti-oxidant be chosen as 3, the different monooctyl ester of 5-di-t-butyl-4-hydroxy phenylpropionic acid, 3,5-di-t-butyl-4-hydroxy phenylpropionic acid octadecanol ester, one or both or three kinds in Triethylene glycol two [3-(the 3-tertiary butyl-5-methyl-4-hydroxy phenyl) propionic ester], its consumption is the 0.01%-1.5% of composition weight; When main anti-oxidant select wherein two or three time, the adding proportion of each component is without particular restriction.
Addition for auxiliary antioxidant of the present invention is the 0.1%-4.0% of composition weight, is preferably 0.15%.
In addition, the weight of auxiliary antioxidant is the 0.001%-99.999% of main anti-oxidant and auxiliary antioxidant weight sum, is preferably 0.1%-50.0%; The weight sum of main anti-oxidant and auxiliary antioxidant is the 0.01%-20.0% of composition weight, is preferably 0.1%-4.0%.
In this polyhydric alcohol composition, described polyvalent alcohol is polyether glycol or polyester polyol.As preferred embodiments of the present invention, described polyvalent alcohol is soft bubble sponge polyether glycol.
The preferred composition scheme of the present invention is: in polyhydric alcohol composition weight for 100%, comprise polyether glycol or the polyester polyol of 99.7%, the tetramethylolmethane four (3-lauryl thiopropionate) of 0.15%, 0.15% 3, the different monooctyl ester of 5-di-t-butyl-4-hydroxy phenylpropionic acid or 3,5-di-t-butyl-4-hydroxy phenylpropionic acid octadecanol ester.
The most preferred composition scheme of the present invention is: in polyhydric alcohol composition weight for 100%, comprise the soft bubble sponge polyether glycol of 99.7%, the tetramethylolmethane four (3-lauryl thiopropionate) of 0.15%, 0.15% 3, the different monooctyl ester of 5-di-t-butyl-4-hydroxy phenylpropionic acid or 3,5-di-t-butyl-4-hydroxy phenylpropionic acid octadecanol ester.
Second object of the present invention improves the method for polyhydric alcohol composition oxidative stability, and the technical scheme of employing is: the auxiliary antioxidant adding main anti-oxidant and the following general formula of at least one in polyvalent alcohol:
Wherein, R is the alkyl of 1-24 carbon atom.
Main anti-oxidant, the selection of auxiliary antioxidant, preferred version and preferred embodiment and consumption same as above, do not repeat at this.
3rd object of the present invention is to provide the purposes of above-mentioned main anti-oxidant and auxiliary antioxidant raising polyvalent alcohol antioxidant property.
The advantage that the present invention has and positively effect are: from antioxidant action mechanism, hindered phenol anti-oxidants is used alone the thermostability that can provide for polyvalent alcohol under applied at elevated temperature condition, monothioester class antioxidant is as a kind of auxiliary antioxidant, use composite with hindered phenol anti-oxidants, both composite generation synergistic effects, can significantly improve the antioxygenic effect of polyvalent alcohol.
Embodiment
Be applied in polyether glycol by antioxidant of the present invention, form polyhydric alcohol composition, its effect is by dsc (DSC) and oven ageing description of test.
(1) determine with dsc method initial oxidation temperature, if this temperature is far away higher than the internal temperature of polyurethane foam production process, (polyurethane foam production is a chemical reaction process, temperature constantly raises, the highest about 180 DEG C), can predict that polyol product has satisfactory stability and security in use.
(2) oven ageing experiment detects YI value, also can characterize the ageing resistance of polyol product by the colour-change of polyvalent alcohol after 120 DEG C of oven aging experiments.
The formula of composition totally four kinds, as shown in the table, be respectively embodiment 1, embodiment 2, comparative example 1 and comparative example 2.
The addition that in the present invention, antioxidant is total is 0.3% (wt%), and the mixing process of polyol blends is carried out under nitrogen protection, uses mechanical stirring to stir 30min.
The experimentation of dsc (DSC) adopts the initial oxidation temperature of programmed temperature method measure sample, initial temperature is 25 DEG C, with the ramp of 10K/min, and sample quality about 6.5mg, oxygen flow 50ml/min, out of service after observing exothermic peak.
The experimentation reference standard GB/T 19466.6-2009 of dsc measurement initial oxidation temperature carries out.
Oven ageing experiment is placed in 120 DEG C of baking ovens by mixed polyether glycol to measure YI value after 24 hours.
Often organize composition and all carry out DSC test and oven ageing experiment, each measurement of each experiment 3 times, the experimental data of following table is the mean value measured for 3 times, and specific experiment result is as following table.
| Initial oxidation temperature, DEG C | YI(D1925) |
| Embodiment 1 | 195.9 | 0.29 |
| Embodiment 2 | 199.7 | 0.22 |
| Comparative example 1 | 158.4 | 3.82 |
| Comparative example 2 | 162.1 | 4.11 |
After notebook data confirms that antioxidant of the present invention is applied to polyvalent alcohol, the temperature that polyvalent alcohol starts to occur oxidative degradation significantly improves; After the polyether glycol adding antioxidant is carried out 120 DEG C/24 hours oven aging experiments, yellowness index (YI) value is lower, illustrate that the ability of the thermo oxidative aging of polyether glycol is stronger, to sum up, the polyhydric alcohol composition of the present embodiment has excellent antioxidative stabilizer.
Above limited embodiments of the present invention has been described in detail, but described content being only preferred embodiment of the present invention, can not being considered to for limiting practical range of the present invention.All equalizations done according to the present patent application scope change and improve, and all should still belong within patent covering scope of the present invention.