A kind of modified phenolic resins
Technical field
The invention belongs to technical field of polymer materials, particularly relate to a kind of modified phenolic resins.
Background technology
Resol is that phenols and aldehydes react the general designation of resin generated under catalyzer existent condition, it is the macromolecular material of suitability for industrialized production the earliest, resol after solidification has good physics, chemical property, is widely used in all respects such as industry, agricultural, national defence and national economy.
Resol is often used to make jointing material, friction materials, refractory materials, laminating material etc., because phenolic resin starting material is easy to get, cheap, production technique and equipment requirements simple, and goods have excellent mechanical property, thermotolerance, winter hardiness, insulativity, dimensional stability, forming process type, flame retardant resistance and low smoke.Resol relies on the cementability of its excellence and thermotolerance to become one of indispensable material in emery wheel process industry.
Emery wheel is the circular bonded abrasive tool having through hole with abrasive material and bonding agent mixing through pressed compact, drying, roasting and the central authorities of making.Emery wheel is the one that in grinding tool, consumption is maximum, use face is the widest, high speed rotating during use, can roughly grind, the mach instrument of the mode such as half fine grinding, fine grinding, fluting and cut-out to the cylindrical of workpiece, inner circle, plane and various profiles etc.Adopt resol, epoxy resin, urethane resin, the emery wheel that polyvinyl alcohol resin etc. are made as bonding agent, is called as resin wheel.The features such as resin wheel has that intensity is high, elasticity is large, shock-resistant, soundness, and in numerous resin wheel, resol emery wheel is one of most widely used resin wheel.
The Main Function of resol in emery wheel manufacture is loose abrasive consolidation, is formed and has definite shape, certain degree of hardness and intensity, and the grinding tool having certain grinding performance.Because resol is the material that a kind of and various organic filler and mineral filler can be compatible, and its most important feature is exactly high thermal resistance, even if at very high temperatures, also can keep the globality of its structure and the stability of size.Therefore, in the industry keen interest is remain to the applicating and exploitation of resol in emery wheel always, but constantly strengthen along with its function, Application Areas widening in succession, some shortcomings of resol also display in succession, this wherein very important shortcoming is exactly that the storage cycle of the emery wheel manufactured by resol is short, and its performance can, along with the prolongation in storage time, cause the intensity of emery wheel and belt cutting-resisting property to decline all to some extent being subject to the external environment such as factor such as temperature, humidity impact.
In existing practical situation, the way that emery wheel manufacturer adopts the sand wheel seal of new production to preserve usually, but this not only adds the production cost of emery wheel, and create limitation in all many-sides such as transport, secondary stocks.Therefore, how inherently to extend the storage cycle of resol emery wheel, slow down the speed of its performance degradation, become problem demanding prompt solution in industry.
Summary of the invention
In view of this, the technical problem to be solved in the present invention is to provide a kind of modified phenolic resins, the emery wheel prepared by modified phenolic resins provided by the invention improves the stability of storage, has delayed the performance degradation of emery wheel in storage process, and has had higher Nai Qiedu and cutting efficiency.
The invention provides a kind of preparation method of modified phenolic resins, comprise the following steps:
A) under the effect of an acidic catalyst, phenolic compound and activator are heated generation first under the condition of constant pH and reacts, obtain the first reaction mixture;
B) by above-mentioned steps A) reaction mixture, phenolic compound and the aldehyde compound that obtain carry out the second reaction, obtains the second reaction mixture;
C), after being mixed with properties-correcting agent by above-mentioned second reaction mixture, modified phenolic resins is obtained;
Described activator is xylogen;
Described properties-correcting agent is xylene formaldehyde resin.
Preferably, described phenolic compound is phenol, xylenol, nonylphenol, dihydroxyphenyl propane, Bisphenol F, Resorcinol or cardanol.
Preferably, described aldehyde compound is formaldehyde, acetaldehyde, salicylic aldehyde, furfural or polyoxymethylene.
Preferably, described an acidic catalyst is oxalic acid, phosphoric acid, sulfuric acid or hydrochloric acid.
Preferably, described xylene formaldehyde resin number-average molecular weight is 400 ~ 2000; The viscosity of described xylene formaldehyde resin at 50 DEG C is 2000 ~ 2500mPa.s; The oxygen level of described xylene formaldehyde resin is 6wt% ~ 12wt%.
Preferably, described steps A) in the mass ratio of phenolic compound and xylogen be 1:(0.01 ~ 1.0); Described step B) in the mass ratio of phenolic compound and xylogen be (2.5 ~ 3.5): 1; Described step B) in the mol ratio of phenolic compound and aldehyde compound be 1:(0.40 ~ 0.88).
Preferably, described properties-correcting agent and steps A) in the mass ratio of phenolic compound be 1:(0.02 ~ 0.20).
Preferably, described constant pH is 0.2 ~ 6.5.
Preferably, the temperature of described first reaction is 75 ~ 185 DEG C; The temperature of described second reaction is 65 ~ 100 DEG C; The temperature of described mixing is 101 ~ 180 DEG C.
The invention provides a kind of resin wheel, it is characterized in that, comprise the modified phenolic resins described in any one in abrasive material and technique scheme;
The mass ratio of described abrasive material and modified phenolic resins is (6 ~ 10): 1.
The invention provides a kind of preparation method of modified phenolic resins, comprise the following steps: under the effect of an acidic catalyst, phenolic compound and activator are heated generation first under the condition of constant pH and reacts, obtain the first reaction mixture; By above-mentioned steps A) reaction mixture, phenolic compound and the aldehyde compound that obtain carry out the second reaction, obtains the second reaction mixture; After being mixed with properties-correcting agent by above-mentioned second reaction mixture, obtain modified phenolic resins; Described activator is xylogen; Described properties-correcting agent is xylene formaldehyde resin.Present invention also offers a kind of resin wheel prepared by above-mentioned modified phenolic resins.Compared with prior art, modified phenolic resins prepared by the present invention take xylogen as activator, and to the further phenolate of activator, adds properties-correcting agent again simultaneously, thus enhance toughness and the water resistance of resin.The resin wheel that the modified phenolic resins prepared with the present invention is prepared for raw material, improves the stability of storage, has delayed the performance degradation of emery wheel in storage process, and has had higher Nai Qiedu and cutting efficiency.Experimental result shows, resin wheel provided by the invention in placement after three months, performance degradation degree is that revolving strength have dropped 4.1%, cutting efficiency have dropped 4.4%, cutting than have dropped 8.6%, performance degradation degree is all better than phenolic resin emery wheel.
Embodiment
In order to understand the present invention further, below in conjunction with embodiment, the preferred embodiment of the invention is described, but should be appreciated that these describe just in order to further illustrate the features and advantages of the present invention, instead of the restriction to invention claim.
The invention provides a kind of preparation method of modified phenolic resins, comprise the following steps:
A) under the effect of an acidic catalyst, phenolic compound and activator are heated generation first under the condition of constant pH and reacts, obtain the first reaction mixture;
B) by above-mentioned steps A) reaction mixture, phenolic compound and the aldehyde compound that obtain carry out the second reaction, obtains the second reaction mixture;
C), after being mixed with properties-correcting agent by above-mentioned second reaction mixture, modified phenolic resins is obtained;
Described activator is xylogen;
Described properties-correcting agent is xylene formaldehyde resin.
Modified phenolic resins provided by the invention, using xylogen as activator, and under sour environment, phenolic compound is destroyed the structure such as ehter bond and ester bond on the long molecular chain of xylogen, again phenolic compound is accessed on the methylol active function groups in lignin molecule, further increase the quantity of xylogen active site; Add properties-correcting agent again and form external phase, thus enhance toughness and the water resistance of resin.
The present invention is raw materials used, is not particularly limited, commercially buys its source.
Phenolic compound and activator, first under the effect of an acidic catalyst, are heated generation first and react, obtain the first reaction mixture by the present invention under the condition of constant pH.
Described activator is preferably xylogen, is more preferably alkali lignin, calcium lignin sulphonate or sodium lignosulfonate, most preferably is alkali lignin; Described phenolic compound is preferably phenol, xylenol, nonylphenol, dihydroxyphenyl propane, Bisphenol F, Resorcinol or cardanol, is more preferably phenol, dihydroxyphenyl propane or Resorcinol; Described an acidic catalyst is preferably oxalic acid, phosphoric acid, sulfuric acid or hydrochloric acid, is more preferably oxalic acid, phosphoric acid or hydrochloric acid; The mass ratio of described phenolic compound and xylogen is preferably 1:(0.01 ~ 1.0), be more preferably 1:(0.05 ~ 0.09); Described pH value is preferably 0.2 ~ 6.5, is more preferably 0.5 ~ 6.0; The temperature of described first reaction is preferably 75 ~ 185 DEG C, is more preferably 100 ~ 160 DEG C; The time of described first reaction is preferably 1 ~ 3 hour, is more preferably 1.5 ~ 2.5 hours.
The consumption of the present invention to an acidic catalyst is not particularly limited, and can occur first react with above-mentioned phenolic compound and activator in described pH value range.The concentration of the present invention to an acidic catalyst is not particularly limited, with the typical concentrations of an acidic catalyst well known to those skilled in the art; The mode of the present invention to heating is not particularly limited, with type of heating well known to those skilled in the art; The present invention, for making reaction process uniform and stable, stirs in preferred process simultaneously, and the present invention is not particularly limited described stirring, with alr mode well known to those skilled in the art and whipping device; The source of the present invention to xylogen is not particularly limited, and obtains or commercially availablely to obtain with xylogen preparation method well known to those skilled in the art.
The first reaction mixture, phenolic compound and aldehyde compound that above-mentioned steps obtains by the present invention carry out the second reaction, obtain the second reaction mixture.
Described phenolic compound is preferably phenol, xylenol, nonylphenol, dihydroxyphenyl propane, Bisphenol F, Resorcinol or cardanol, is more preferably phenol, dihydroxyphenyl propane or Resorcinol; Described aldehyde compound is preferably formaldehyde, acetaldehyde, salicylic aldehyde, furfural or polyoxymethylene, is more preferably formaldehyde or furfural; In described second reaction, described phenolic compound and xylogen mass ratio preferably (2.5 ~ 3.5): 1, be more preferably (2.8 ~ 3.2): 1; In described second reaction, the mol ratio of described middle phenolic compound and aldehyde compound is preferably 1:(0.40 ~ 0.88), be more preferably 1:(0.45 ~ 0.82); The temperature of described second reaction is preferably 65 ~ 100 DEG C, is more preferably 70 ~ 90 DEG C; The time of described second reaction is preferably 1 ~ 3 hour, is more preferably 1.5 ~ 2.5 hours.
The detailed process of the present invention to above-mentioned second reaction is not particularly limited, with the process of phenol-formaldehyde reaction well known to those skilled in the art, the present invention is for ensureing that activator better can participate in reaction, and improve reaction efficiency, above-mentioned second reaction process is preferably carried out according to following steps:
First by after the first reaction mixture be obtained by reacting and phenolic compound mixing, then constant temperature drips aldehyde compound, finally heats up again and carries out the second reaction, obtain the second reaction mixture.
The temperature of described mixing is preferably 65 ~ 79 DEG C, is more preferably 68 ~ 75 DEG C, and the temperature of described constant temperature is preferably 80 ~ 94 DEG C, is more preferably 83 ~ 92 DEG C; The temperature of described intensification is preferably 95 ~ 100 DEG C, is more preferably 96 ~ 99 DEG C; The present invention is not particularly limited mixing, with hybrid mode well known to those skilled in the art, is preferably uniform stirring mixing; The present invention is not particularly limited stirring, with alr mode well known to those skilled in the art and whipping device; The present invention is not particularly limited dropping, with dropping mode well known to those skilled in the art and rate of addition, preferably slowly adds; The present invention's other conditions to above-mentioned reaction are not particularly limited, with phenol-formaldehyde reaction condition well known to those skilled in the art.
The present invention finally obtains modified phenolic resins after being mixed with properties-correcting agent by above-mentioned second reaction mixture.
Described properties-correcting agent is preferably xylene formaldehyde resin; Described xylene formaldehyde resin has formula I structure,
Wherein, n is preferably 5≤n≤10, is more preferably 4≤n≤9; Described xylene formaldehyde resin number-average molecular weight is preferably 400 ~ 2000, is more preferably 500 ~ 1800; The viscosity of described xylene formaldehyde resin at 50 DEG C is preferably 2000 ~ 2500mPa.s, is more preferably 2100 ~ 2400mPa.s; The oxygen level of described xylene formaldehyde resin is preferably 6wt% ~ 12wt%, is more preferably 8wt% ~ 10wt%; Described in described properties-correcting agent and first reacts, the mass ratio of phenolic compound is preferably 1:(0.02 ~ 0.20), be more preferably 1:(0.05 ~ 0.15); The temperature of described mixing is preferably 101 ~ 180 DEG C, is more preferably 110 ~ 170 DEG C.
The present invention is the mixed effect improving properties-correcting agent and resol, preferably before combination first by above-mentioned second reaction mixture heating distillation dehydration, then mix, then distillation dehydration is carried out in intensification.
The described temperature adding thermal distillation is preferably 110 ~ 140 DEG C, is more preferably 115 ~ 135 DEG C; The temperature of described mixing is preferably 102 ~ 130 DEG C, is more preferably 105 ~ 125 DEG C; The temperature of described intensification is preferably 130 ~ 180 DEG C, is more preferably 140 ~ 170 DEG C.
The present invention is not particularly limited above-mentioned mixing, with hybrid mode well known to those skilled in the art, is preferably uniform stirring mixing; The present invention is not particularly limited stirring, with alr mode well known to those skilled in the art and whipping device; The pressure of the present invention to above-mentioned steps is not particularly limited, and with operating method well known to those skilled in the art, is preferably normal pressure; The equipment of the present invention to above-mentioned heat temperature raising is not particularly limited, with heating installation well known to those skilled in the art.
The present invention preferably, after above-mentioned second reaction mixture and properties-correcting agent mixed dehydration, carries out vacuum dephenolize, finally obtains modified phenolic resins.The requirement of described dephenolize is make the free phenol mass content in said mixture be less than or equal to 5%, is more preferably and is less than or equal to 3%; The pressure of described vacuum is preferably less than or equal to 0.01MPa, is more preferably and is less than or equal to 0.008MPa; The temperature of described dephenolize is preferably 130 ~ 180 DEG C, is more preferably 140 ~ 170 DEG C; The present invention's other conditions to above-mentioned dephenolize are not particularly limited, with the condition in dephenolize process well known to those skilled in the art; The present invention is not particularly limited the equipment vacuumized, with vaccum-pumping equipment well known to those skilled in the art.
The present invention is using xylogen as activator, and under sour environment, phenolic compound is destroyed the structure such as ehter bond and ester bond on the long molecular chain of xylogen, again phenolic compound is accessed on the methylol active function groups in lignin molecule, further increase the quantity of xylogen active site, xylogen also instead of quite a few phenol simultaneously, effectively reduces cost.The present invention is on the basis using activator, add again properties-correcting agent xylene formaldehyde resin, xylene formaldehyde resin and resol are blended into external phase, containing ehter bond, hydroxyl isoreactivity group in xylene formaldehyde resin molecular structure, ehter bond wherein can react with the phenolic hydroxyl group of resol, reduces the content of phenolic hydroxyl group in resol, improves its moisture resistance properties and resistance toheat, strengthen the toughness of resin, strengthen the water resistance of resin.
Present invention also offers a kind of resin wheel, it is characterized in that, comprise the modified phenolic resins that abrasive material and above-mentioned any one technical scheme prepare.The mass ratio of described abrasive material and modified phenolic resins is preferably (6 ~ 10): 1, is more preferably (7 ~ 9): 1; The present invention is not particularly limited other fillers in resin wheel, or also can select suitable filler according to actual needs with filler well known to those skilled in the art.
The modified phenolic resins with higher toughness and water tolerance that the present invention is prepared with aforesaid method is for raw material, the resin wheel of preparation, improve the stability of storage, delayed the performance degradation of emery wheel in storage process, and there is higher Nai Qiedu and cutting efficiency.Experimental result shows, resin wheel provided by the invention in placement after three months, performance degradation degree is that revolving strength have dropped 4.1%, cutting efficiency have dropped 4.4%, cutting than have dropped 8.6%, performance degradation degree is all better than phenolic resin emery wheel.
In order to understand the present invention further, be described the preparation method of modified phenolic resins provided by the invention and resin wheel below in conjunction with embodiment, protection scope of the present invention is not limited by the following examples.
Comparative example 1
First by 100g phenol in reactor, stir, then add catalyzer oxalic acid in reactor, regulate pH value be 2.5, then heat temperature raising, to 90 DEG C drip formaldehyde, the mol ratio of formaldehyde and phenol is 0.8:1, need in dropping process maintenance temperature be 88 DEG C.Then be warming up to 95 DEG C and continue polycondensation 1 hour, after having reacted, obtain reaction mixture.Mixture is heated to 120 DEG C of distillation dehydrations at ambient pressure, stirs and be then warming up to 150 DEG C of continuation air distillation dehydrations.In the vacuum under pressure dephenolize of 0.01MPa after having dewatered, when the mass content of the free phenol in said mixture equals 1%, finally obtain resol.
Aforesaid method being prepared resol, to add mass content be after the hexamethylenetetramine abrasive dust of 12%, again with liquid phenolic resin, diamond, FeS, sodium aluminum fluoride, carbon black, fine particle calcium carbonate according to mass ratio 12:6:100:6:3:0.3:1.5, preparing specification is 405*3*25.4mm(diameter * thickness * aperture) emery wheel section 1.
Embodiment 1
First by 100g phenol and 1g xylogen in reactor, stir, then add catalyzer phosphoric acid in reactor, regulate pH value to be 2.5, be then heated to 140 DEG C and carry out the first reaction, isothermal reaction, after 1 hour, obtains the first reaction mixture.
Then above-mentioned first reaction mixture is cooled to 70 DEG C, adds 3g phenol and stir, and mix.Be warming up to 90 DEG C again and drip formaldehyde, the mol ratio of formaldehyde and phenol is 0.7:1, needs to keep temperature to be 88 DEG C in dropping process.Then be warming up to 95 DEG C and continue polycondensation 1 hour, after having reacted, obtain the second reaction mixture.After at ambient pressure above-mentioned second reaction mixture being heated to 120 DEG C of distillation dehydrations, then be cooled to 110 DEG C, add 5g xylene formaldehyde resin, stir and be then warming up to 150 DEG C of continuation air distillation dehydrations.In the vacuum under pressure dephenolize of 0.01MPa after having dewatered, when the mass content of the free phenol in said mixture equals 1%, finally obtain modified phenolic resins.
Aforesaid method being prepared resol, to add mass content be after the hexamethylenetetramine abrasive dust of 12%, again with liquid phenolic resin, diamond, FeS, sodium aluminum fluoride, carbon black, fine particle calcium carbonate according to mass ratio 12:6:100:6:3:0.3:1.5, preparing specification is 405*3*25.4mm(diameter * thickness * aperture) emery wheel section a.
Embodiment 2
First by 100g phenol and 1g xylogen in reactor, stir, then add catalyzer phosphoric acid in reactor, regulate pH value to be 2.5, be then heated to 140 DEG C and carry out the first reaction, isothermal reaction, after 1 hour, obtains the first reaction mixture.
Then above-mentioned first reaction mixture is cooled to 70 DEG C, adds 3g phenol and stir, and mix.Be warming up to 90 DEG C again and drip formaldehyde, the mol ratio of formaldehyde and phenol is 0.7:1, needs to keep temperature to be 88 DEG C in dropping process.Then be warming up to 95 DEG C and continue polycondensation 1 hour, after having reacted, obtain the second reaction mixture.After at ambient pressure above-mentioned second reaction mixture being heated to 120 DEG C of distillation dehydrations, then be cooled to 110 DEG C, add 6g xylene formaldehyde resin, stir and be then warming up to 150 DEG C of continuation air distillation dehydrations.In the vacuum under pressure dephenolize of 0.01MPa after having dewatered, when the mass content of the free phenol in said mixture equals 1%, finally obtain modified phenolic resins.
Aforesaid method being prepared resol, to add mass content be after the hexamethylenetetramine abrasive dust of 12%, again with liquid phenolic resin, diamond, FeS, sodium aluminum fluoride, carbon black, fine particle calcium carbonate according to mass ratio 12:6:100:6:3:0.3:1.5, preparing specification is 405*3*25.4mm(diameter * thickness * aperture) emery wheel section b.
Embodiment 3
First by 100g phenol and 1g xylogen in reactor, stir, then add catalyzer phosphoric acid in reactor, regulate pH value to be 2.5, be then heated to 140 DEG C and carry out the first reaction, isothermal reaction, after 1 hour, obtains the first reaction mixture.
Then above-mentioned first reaction mixture is cooled to 70 DEG C, adds 3g phenol and stir, and mix.Be warming up to 90 DEG C again and drip formaldehyde, the mol ratio of formaldehyde and phenol is 0.7:1, needs to keep temperature to be 88 DEG C in dropping process.Then be warming up to 95 DEG C and continue polycondensation 1 hour, after having reacted, obtain the second reaction mixture.After at ambient pressure above-mentioned second reaction mixture being heated to 120 DEG C of distillation dehydrations, then be cooled to 110 DEG C, add 7g xylene formaldehyde resin, stir and be then warming up to 150 DEG C of continuation air distillation dehydrations.In the vacuum under pressure dephenolize of 0.01MPa after having dewatered, when the mass content of the free phenol in said mixture equals 1%, finally obtain modified phenolic resins.
Aforesaid method being prepared resol, to add mass content be after the hexamethylenetetramine abrasive dust of 12%, again with liquid phenolic resin, diamond, FeS, sodium aluminum fluoride, carbon black, fine particle calcium carbonate according to mass ratio 12:6:100:6:3:0.3:1.5, preparing specification is 405*3*25.4mm(diameter * thickness * aperture) emery wheel section c.
Embodiment 4
By the emery wheel 1 obtained by comparative example 1 and the emery wheel a ~ c obtained by embodiment 1 ~ 3, detect the revolving strength of emery wheel with JS-500QZD-BG3P type revolving strength trier; Cutting experiment employing specification is the 201 material stainless steel angle steel of ∠ 25 × 25 × 3, cuts 10 cuttves, and calculate cutting efficiency and cutting ratio, see table 1, table 1 is revolving strength and the cutting property data of emery wheel 1 and emery wheel a ~ c.
The revolving strength of table 1 emery wheel 1 and emery wheel a ~ c and cutting property data
|
Revolving strength (rev/min) |
Cutting efficiency |
Cutting ratio |
Emery wheel section 1 |
7470 |
4.587 |
2.3 |
Emery wheel section a |
7460 |
4.536 |
2.26 |
Emery wheel section b |
7560 |
4.635 |
2.37 |
Emery wheel section c |
7640 |
4.698 |
2.57 |
After emery wheel places three months, again detect the cutting efficiency in the revolving strength of emery wheel and cutting experiment and cutting ratio, see table 2, table 2 be after three months emery wheel 1 and emery wheel a ~ c cut after performance data.
Table 2 is emery wheel 1 and emery wheel a ~ c cutting property data after three months
|
Revolving strength (rev/min) |
Cutting efficiency |
Cutting ratio |
Emery wheel section 1 |
7030 |
3.824 |
1.94 |
Emery wheel section a |
7120 |
4.287 |
2.15 |
Emery wheel section b |
7210 |
4.356 |
2.26 |
Emery wheel section c |
7330 |
4.493 |
2.35 |
As can be seen from Table 1, comparative example 1 is the phenolic resin emery wheel of the modified phenolic resins not using the present invention to prepare.From revolving strength and cutting effect, the resin wheel that the modified phenolic resins prepared with the present invention is prepared for raw material, has higher revolving strength and cutting property.
As can be seen from Table 2, after resin wheel places three months, the performance degradation degree of phenolic resin emery wheel is that revolving strength have dropped 5.9%, cutting efficiency have dropped 16.63%, cutting is than have dropped 15.65%, and for the embodiment of the present invention 3, performance degradation degree is that revolving strength have dropped 4.1%, cutting efficiency have dropped 4.4%, cutting is than have dropped 8.6%.The modified phenolic resins that the performance degradation degree of phenolic resin emery wheel is all prepared higher than the present invention is the performance degradation degree of resin wheel prepared by raw material.
Above the preparation method of a kind of modified phenolic resins provided by the present invention and resin wheel are described in detail.Apply a concrete example herein to set forth principle of the present invention and embodiment, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also carry out some improvement and modification to the present invention, these improve and modify and also fall in the protection domain of the claims in the present invention.