Second aspect of the present invention provides a kind of toughened glass that contains lithium with a plurality of stressor layers; Be characterised in that described glass prepares according to foregoing method; Described glass, bearing stress is greater than 850MPa after IX, and total bearing stress layer depth is greater than 120 μ m.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, be characterised in that after IX bearing stress is preferably greater than 900MPa greater than 850MPa.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, be characterised in that after IX total bearing stress layer depth is preferably greater than 150 μ m greater than 120 μ m.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention; Be characterised in that after IX; 1: 20＜first sheath thickness: all the other sheath thickness＜1: 2; Be preferably 1: 18＜the first sheath thickness: all the other sheath thickness＜1: 5, more preferably 1: 15＜first sheath thickness: all the other sheath thickness＜1: 8.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, be characterised in that after IX under the test condition of 200g power and 10 seconds, the Vickers' hardness of glass surface is higher than 680kgf/mm², preferably be higher than 700kgf/mm², especially preferably be higher than 720kgf/mm²

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, be characterised in that after IX 4 flexural strengths of toughened glass goods are higher than 550MPa, preferably are higher than 600MPa, especially preferably are higher than 650MPa.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, be characterised in that the described lithium glass that contains has following composition:

The preferred component scope is:

Most preferably composition range is:

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, in 4 buckling strength tests, standard deviation is very little, less than 30MPa, preferably less than 20MPa, especially preferably less than 10MPa.

In the toughened glass that contains lithium with a plurality of stressor layers of second aspect present invention, the purposes with toughened glass that contains lithium of a plurality of stressor layers as cover plates such as touch pad, indicating meter, consumer-elcetronics devices, household electrical appliance, the vehicles of the present invention.

Therefore, the inventive method guarantees the HS of glass simultaneously on the basis of improving bearing stress and surface hardness behind the lithium aluminosilicate glass tempering, and this provides sound assurance for the safety of electronic product and scratch resistance.

The chemical tempering lithium alumina silicate glass that the application of the invention is novel and the treatment process of relevant glasswork, the glass with many stressor layers and the goods thereof of acquisition are adapted at using as the HS cover plate in electron device, household electrical appliance and the vehicles.Compared with prior art, the toughened glass that has many stressor layers can provide more reliable protection for electron device, household electrical appliance and the vehicles.

The accompanying drawing summary

Fig. 1: different sorts glass adopts the surperficial Vickers' hardness after related process is strengthened.

Detailed Description Of The Invention

The present invention provides a kind of tempering of novelty to be suitable in electron device, household electrical appliance and the vehicles as the lithium alumina silicate glass of HS cover plate application and the chemical treatment method of relevant glasswork.This glass contains the Lithium Oxide 98min of high level, can one step or substep accomplish Li-Na and Na-K IX, obtain having the toughened glass of a plurality of compressive stress layers.

The lithium aluminosilicate glass is generally used for fields such as aviation, adopts NaNO₃Carry out tempering.Because Na and Li ionic quick exchange can reach the very dark stressor layers degree of depth, but bearing stress are relatively low, generally below 600MPa.If adopt KNO₃Carry out tempering, then bearing stress is bigger, and generally more than 800MPa, but the stressor layers degree of depth is too shallow, generally about 10 microns.Because itself contains lithium ion glass, fused salt inevitably contains a certain amount of lithium ion that exchanges.

High CS and dark DoL can realize that promptly, the mixed alkali metal fused salt is handled, or through multistep IX, wherein final step is used for realizing high CS through the IX of one step, and the step of front is used for realizing dark DoL.

The principal character that can carry out the glass of chemical tempering processing is than higher alkali metal content, and the glass that this type of tempering of common carrying out is handled mainly contains the glass of soda-lime glass, sodium aluminosilicate glass and lithium al-si system etc.

Soda-lime glass can't reach effective tempering and handle because aluminium content wherein is very low, and bearing stress is lower usually, and the stressor layers degree of depth is also more shallow.Soda-lime glass and sodium aluminosilicate glass all adopt KNO usually₃Carry out chemical tempering.The content of sodium ion will be strict controlled in certain level to prevent the decay of tempering effect in the fused salt.The sodium aluminosilicate glass can reach the effective stressor layers degree of depth and the above bearing stress of 600MPa about 40 microns.

In one embodiment, ion exchange process is only accomplished in a kind of fused salt mixt, and this fused salt mixt comprises lithium, sodium and potassium metals ion, wherein Li: Na: K in ion exchange process mol ratio is 0-1: 2.5-10: 90-97.5.Glass surface stress under compression CS after a step fused salt mixt tempering is higher than 600MPa, and preferred CS is higher than 700MPa, and further preferred CS is higher than 800MPa.

The glass surface sheath degree of depth after a step fused salt mixt tempering is greater than 80 microns.In one embodiment, the sheath degree of depth is greater than 120 microns, and in another embodiment, the sheath degree of depth surpasses greater than 150 microns.(the first stressor layers sheath degree of depth)/(all the other stressor layers sheath degree of depth) of the glass surface after a step fused salt mixt tempering greater than 1: 20, is preferably greater than 1: 15, is preferably greater than 1: 10 especially.The Vickers' hardness of glass surface is higher than 670kgf/mm², preferably be higher than 680kgf/mm², especially preferably be higher than 690kgf/mm²

In other embodiment, ion exchange process comprises several separate steps and corresponding different fused salt, and the fused salt composition of each step IX is different.The main alkalimetal ion that contains in IX of each step is a kind of in sodium, potassium, rubidium, the caesium.Use contains the fused salt processing of the less relatively main alkalimetal ion of radius, and the fused salt that contains the relatively large main alkalimetal ion of radius prior to use is handled.

Further, wherein at least one step is contained the fused salt of first kind of main alkalimetal ion, and at least one in addition step is contained the fused salt of second kind of main alkalimetal ion, and wherein the radius of first kind of main alkalimetal ion of ratio of ionic radii of second kind of main alkalimetal ion is big.Each step fused salt ion exchange process is not limited to single salt, can contain the mixing salt of Different Alkali metals ion.In the fused salt exchange that contains first kind of main alkalimetal ion; The concentration range of first kind of main alkalimetal ion is 50-100mol.%; And in the fused salt exchange that contains second kind of essential species alkalimetal ion, the concentration of second kind of main alkalimetal ion is 80-100mol.%.

In one embodiment, IX is accomplished in two steps.

In other embodiment, also comprise the fused salt IX in the 3rd step, the first step contains the fused salt of first kind of main alkalimetal ion, and second step and the 3rd step are contained the fused salt of second kind of main alkalimetal ion.The concentration of second kind of main alkalimetal ion in second kind of main second step of the alkalimetal ion concentration ratio salt bath that contains in the 3rd step salt bath is high.In another embodiment; Contain the third alkalimetal ion in the 3rd step salt bath; The radius of second kind of alkalimetal ion of ratio of ionic radii of this third alkalimetal ion is big; Described the third alkalimetal ion both can be that (concentration of metal ions in the salt bath＞50mol.%) also can be a less important ion (concentration of metal ions in the salt bath＜50mol.%) to leading ion.

Further, chemical tempering process of the present invention also comprises the IX in the 4th step, wherein contains the third alkalimetal ion, but its concentration is higher than the concentration of this ion in the 3rd step salt bath.In another embodiment, contain the 4th kind of alkalimetal ion, it is bigger than the ionic radius of the third alkalimetal ion, and described the 4th kind of alkalimetal ion both can be leading ion, also can be less important ion.

In multistep IX of the present invention, the radius of the main alkalimetal ion that the ratio of ionic radii of the main alkalimetal ion that in any a certain step salt bath, contains contains in a last step is big.If the ionic radius of the main alkalimetal ion that in any a certain step salt bath, contains is identical with the radius of the main alkalimetal ion in a last step, then the concentration ratio of main alkalimetal ion main alkalimetal ion concentration in a last step wants high in this step.Lithium concentration in any a certain step salt bath is lower than the lithium concentration in the last step salt bath, and lithium concentration is lower than 1mol.% in the final step salt bath.Main alkalimetal ion concentration in the end in the step salt bath concentration be higher than 95mol.%, preferably be higher than 97mol.%, especially preferably be higher than 99mol.%.

Glass surface stress under compression CS after the multistep tempering is handled is higher than 850MPa, preferably is higher than 900MPa, further preferably is higher than 1000MPa, and the glass surface sheath degree of depth surpasses 120 microns, preferably surpasses 150 microns, more preferably above 180 microns.As when being used for the application of some special dimension, the sheath degree of depth can reach more than 250 microns.Glass surface after the multistep tempering (the first stressor layers sheath degree of depth)/(all the other stressor layers sheath degree of depth) greater than 1: 20, is preferably greater than 1: 15, most preferably greater than 1: 10.The Vickers' hardness of glass surface is higher than 680kgf/mm², preferably be higher than 700kgf/mm², especially preferably be higher than 720kgf/mm²

Said salt bath is selected from nitrate salt, carbonate, vitriol, phosphoric acid salt, oxyhydroxide, muriate, fluorochemical or its mixture with compound.

In general, with carrying out chemical tempering in the glasswork sheet glass immersion molten salt bath.In the immersion process, basic metal in the glass and the alkalimetal ion generation IX in the salt bath.Large-sized alkalimetal ion gets in the glass structure, causes producing the ion exchange layer (DoL) of bearing stress (CS) and certain depth.For example, K in the salt bath or Na ion can be respectively with glass in Na or Li exchange.After the dipping, forming stress, K-Na ion exchange layer (K DoL) and Na-Li ion exchange layer (Na DoL), the tempering effect of realization glass near the glass surface place.CS and DoL prevent that tiny crack in glass surface and internal extended, can increase substantially glass intensity, and CS can be limited in the DoL scope crackle to improve durability of glass and long-term reliability.

Bearing stress CS has reflected that the surface layer of glass network receives the degree of bigger foreign ion extruding, and DoL has reflected the ability that foreign ion gets into surface layer of glass.In general, the factor that influences IX mainly is glass types, fused salt kind, temperature, time etc.For soda-lime glass, because ion-exchange effect is limited, generally between 100-500MPa, the stress degree of depth is within the 5-20 micrometer range for the top layer stress.For the sodium aluminosilicate glass, generally between 600-800MPa, the stress degree of depth is within the 20-50 micrometer range for the top layer stress.The increase of ion-exchange temperature or the prolongation of time can both further increase the degree of depth of DoL, but can lose CS, make it further to be reduced to outside the above scope.Conversely, the reduction of ion-exchange temperature or the minimizing of time can increase CS, but DoL can only reach the limited degree of depth, for example below 10 microns.With the sodium aluminosilicate glass is example, and when reaching 40 microns sheath degree of depth, the bearing stress of glass can't surpass 750MPa usually.

Comprise two kinds of alkalimetal ions; The glass of Li and Na for example thinks than only comprises the for example glass of sodium of a kind of alkalimetal ion, for example most of sodium aluminum silicate glass; Advantage with other, wherein Li and Na can be exchanged in ion exchange process simultaneously.Ion-exchange speed between Li and the Na ion is far longer than Na and K ionic exchange velocity, causes being easy to ion exchange layer (DoL) degree of depth that reaches bigger.Big DoL has fabulous crackle tolerance, yet, have only Li and Na IX can not form high CS, this is disadvantageous for obtaining high 4 buckling strengths and falling sphere intensity.IX slower between Na and the K produces high CS, and this high surface C S is that glass provides excellent protection.For the aluminosilicate glass that contains Li, Na simultaneously, in chemical tempering, because two kinds of ion-exchange speed differences produce K DoL that is produced by Na and K IX and the Na DoL that is produced by Li and Na IX simultaneously at glass surface.Like this, can after exchange of single step fused salt mixt and multistep IX, obtain to have simultaneously the toughened glass of high CS and DoL.These toughened glass goods have a plurality of ion exchange layers, even under the situation of strong outside scraping, it is dangerous that dark Li-Na ion exchange layer has reduced disruptive; And more shallow Na-K ion exchange layer; During glass bending,, high bearing stress can be provided for realizing better tensile stress.High CS also can prevent progress of fracture simultaneously.Dark DoL and the combination of high CS can realize the long-term reliability of cover plate.

Method of the present invention is applicable to the glasswork of following composition:

The preferred component scope is:

Most preferably composition range is:

Has Li₂O and Na₂The lithium alumina silicate glass of O is realized tempering through Li-Na and Na-K IX.Can be through in comprising Na and the single mixed salt-bath of K ionic, or use in the multistep exchange of a plurality of salt baths with different Li, Na and K ratio and accomplish this process.

Because Li ion diffusion speed is fast, so the IX between Na and the Li is very fast, with the glass of other type for example sodium aluminum silicate, soda-lime glass and borosilicate glass compare, lithium alumina silicate glass can be realized big Na DoL.On the other hand, the IX between K and the Na ion causes the CS greater than 850MPa.

Through the glass surface taseometer that Orihara makes, for example FSM6000 perhaps measures CS through the polarizing microscope with compensating prism.Through the glass surface taseometer that Orihara makes, for example FSM6000 is perhaps technological through compositional analysis, for example energy dispersion X diffraction light spectrometer (EDS) measurement K DoL.Through polarizing microscope, perhaps through compositional analysis technology, for example energy dispersive X diffraction light spectrometer (EDS) measuring N a DoL.

IX is a dynamic process, promptly is accompanied by the carrying out of IX, and the ion in the glass gets in the fused salt, and the ion in the fused salt also can get in the glass.In industrial production, fused salt usually needs to change in use for some time or purifying treatment, and the harmful ion concentration in this moment fused salt is gathered and reached certain limit, and glass properties descends.Change or the purifying treatment fused salt before, the CS of the glass surface of being handled by tempering is slow downward trend along with the increase of fused salt duration of service basically, thereby influences strength of glass.Because the specification of variant prodn is different, fused salt is changed or the frequency of purifying treatment also is not quite similar.The composition of the fused salt that uses among the present invention is to have reflected the dynamic element scope of fused salt in whole use, rather than the composition before its initial composition or the fused salt replacing.

Single step IX is accomplished in a kind of fused salt mixt, and in one embodiment, the mol ratio that this fused salt mixt comprises lithium, sodium and potassium metals ion, wherein Li: Na: K simultaneously is 0-2: 2-10: 90-98.Li and Na, and the exchange of Na and K accomplishes simultaneously, reaches higher bearing stress and darker ion exchange layer simultaneously.The preferred molar ratio of Li: Na: K is 0-1: 2-8: 90-98, more preferably 0-0.5: 2.5-8: 92-96.If Li content surpasses 2mol.%, the CS of glass can be affected and reduce, and the while strength of glass can descend and reach more than 15%.

In other embodiment, the tempering temperature and time of single step fused salt mixt is respectively 370-430 ℃ and 0.5-12 hour; In another embodiment, the tempering temperature and time of single step fused salt mixt is respectively 380-420 ℃ and 0.5-4 hour.

Multistep IX comprises that at least two kinds of salt baths of employing carry out staging treating to glass, wherein the appearance not of uniform size of the main alkalimetal ion in two steps at least.For containing Li₂O and Na₂The glass of O in the multistep tempering, wherein has at least a step to adopt and contains main Na ionic fused salt tempering, its objective is the IX layer depth that realizes more than 120 microns.In addition, at least one step in the multistep need be used the fused salt tempering that contains potassium, its objective is to form different stressor layers, promotes bearing stress and makes it to be higher than 850MPa.In some application specific IC, even can adopt and contain the bigger fused salt of metals ion radius, for example rubidium or caesium further promote bearing stress.

In one embodiment, the salt bath before the final step comprise higher concentration than small ion, that is, and Na ion, and it and Li ion quick exchange.The initial ion exchange helps to form big Na DoL.Along with the carrying out of other ion-exchange step, than heavy ion, that is, K ionic content increases, and forms higher bearing stress gradually.In addition, because minimum ion, that is, and the Li ion, major part is in the end exchanged before the step IX, only has very small amount of Li can enter into the salt bath that final step IX is used.Proved that the Li ion can make the CS that is formed by the K-Na exchange significantly reduce, and therefore must replenish salt bath to keep high CS and favorable mechanical performance.Simultaneously, the Li ionic is assembled fast and is caused the salt bath lost of life.On the other hand, the influence of Li pair ion Na-Li IX is not too obvious, therefore, and the life-span that the rising of Li ion content can significantly not reduce salt bath in the salt bath before the step in the end, the life-span that this multistep IX can the proper extension salt bath.

In other embodiment, the salt bath before the step in the end is the same with the contained main alkalimetal ion kind of salt bath composition of final step.Described main alkalimetal ion in the end one the step salt bath in concentration greater than its in the end one the step before salt bath in concentration.Before carrying out the final step tempering, adopt to have analogous components, but the main lower salt bath of alkalimetal ion concentration helps to extenuate the influence of the residual lithium ion of glass surface to the final step salt bath.

During multistep IX, the melting salt that uses in each step has different compositions.Compound as said salt bath is selected from nitrate salt, carbonate, vitriol, phosphoric acid salt, muriate, fluorochemical or its mixture, and alkalimetal ion is selected from lithium, sodium, potassium, rubidium and/or the caesium one or more.Preferred this salt bath only contains three kinds of alkalimetal ion A, B and C, and ionic radius is A＜B＜C in proper order.Multistep IX is included under the suitable temperature, the glasswork sheet glass is immersed in the individual different salt baths of forming of n (n>=2) continuously keep for some time, preferred 2≤n≤4, more preferably 2≤n≤3, especially preferably n=2.(1≤m≤n) is meant (salt bath that uses in the step IX of 1≤m≤n-1) at m to salt bath m.The salt bath m+1 that in m+1 step IX, uses has higher C content than salt bath m, but has lower A and B content.The salt bath that final step n used in the step has higher C content and lower A and B content than the salt bath in any preceding step.The molar ratio of the alkalimetal ion in the salt bath that in the end uses in the step IX is A: B: C=0-5: 0-10: 90-100, and be preferably A: B: C=0-1: 0-5: 95-100 is preferably A: B: C=0-0.5: 0-1: 99-100 especially.Alkalimetal ion mol ratio in the salt bath that in any preceding step, uses is A: B: C=0-97.5: 2.5-100: 0-5.In at least one step before the step in the end; Alkalimetal ion mol ratio in the salt bath that uses is A: B: C=0-10: 2.5-100: 0-5; Be preferably A: B: C=0-5: 50-100: 0-3; More preferably A: B: C=0-5: 95-100: 0-2 is preferably A: B: C=0-1: 99-100: 0-1 especially.

Further; In the multistep method of the present invention; At least one step comprises the fused salt that contains first kind of main alkalimetal ion; At least one step comprises the fused salt that contains second kind of main alkalimetal ion in addition, and wherein the radius of first kind of main alkalimetal ion of ratio of ionic radii of second kind of main alkalimetal ion is big.In practice, the salt bath of the ion exchange process of each step is not limited only to a kind of single salt, also can be for containing the mixing salt of Different Alkali metals ion.In the fused salt exchange that contains first kind of main alkalimetal ion; The concentration range of first kind of main alkalimetal ion is 50-100mol.%; And in the fused salt exchange that contains second kind of main alkalimetal ion, second kind of main alkalimetal ion concentration is between 80-100mol.%.

Under the situation of the simplest two step IXs, the first step adopts and contains main Na ionic fused salt, helps to form dark DoL; Second step adopted and to contain main K ionic fused salt, helped to form high CS, wherein in the first step fused salt Na ion content greater than 50mol.%; Be preferably greater than 75mol.%, more preferably greater than 90mol.%, and Li ionic content is lower than 5mol.%; Preferably be lower than 3mol.%, more preferably less than 1mol.%.The K ion content is preferably greater than 97mol.% greater than 95mol.% in the second step fused salt, and more preferably greater than 99mol.%, and Li ionic content is lower than 1mol.%, preferably is lower than 0.5mol.%, more preferably less than 0.1mol.%.

In comprising the IX embodiment of three steps, the fused salt of the first step is mainly SODIUMNITRATE, and the fused salt in second step is mainly saltpetre, and the 3rd step was 1: 1 mixing salt of saltpetre and cesium nitrate.After the tempering, glass surface forms three ion exchange layers, i.e. Na exchange layer, K exchange layer and Cs exchange layer.Because the ionic radius of Cs is maximum, forms very high stress at glass surface, generally greater than 1000MPa.

Further, chemical tempering of the present invention comprises the 4th step IX, wherein contains the third alkalimetal ion, but its concentration is higher than its concentration in the 3rd step salt bath.In another embodiment, contain the 4th kind of alkalimetal ion, bigger than the ionic radius of the third alkalimetal ion.Described the 4th kind of alkalimetal ion both can be leading ion, also can be less important ion.

The immersion temperature of each molten salt bath is 360-450 ℃, and the immersion time is 0.1-12 hour.Preferably, the immersion temperature and time of final step fused salt IX is respectively and further is respectively 390-410 ℃ and 2-4 hour for 380-420 ℃ and 2-8 hour.Preferably, the immersion temperature and time of the first step fused salt IX is respectively 380-420 ℃ and 2-8 hour, especially preferably is respectively 400-410 ℃ and 4-8 hour.

In two consecutive steps, can be with glass cools to room temperature, heat up again behind the washing and drying and immerse in next step the salt bath, or do not wash in next step the salt bath of direct immersion.

In one embodiment, in two consecutive steps, glass and the support of placing glass are moved on in the holding furnace, described holding furnace temperature is 350-420 ℃, and preferred temperature is 350-400 ℃, more preferably 360-390 ℃.Warm air can be blowed in this holding furnace,, of the pollution of the residual fused salt of glass surface can be reduced so as far as possible next step fused salt to remove the residual fused salt of glass surface with same temperature.

CS＞the 850MPa of multistep chemcor glass, preferred＞900MPa, especially preferably＞1000MPa.

For mixing salt a step exchange or multistep exchange, the sheath depth characteristic has similarity.In one embodiment, after step exchange or multistep IX, K DoL is preferably greater than 7 microns greater than 6 microns, is preferably greater than 8 microns especially; Na DoL is the 80-250 micron, is preferably the 80-200 micron, is preferably the 80-150 micron especially.In another embodiment, after step exchange or multistep IX, K DoL is preferably greater than 25 microns greater than 15 microns, is preferably greater than 40 microns especially; Na DoL is the 80-350 micron, is preferably the 80-300 micron, preferred especially 100-200 micron.

For mixing salt a step exchange or multistep exchange; When lithium concentration in the fused salt gathers when to a certain degree causing degradation; Can add like broken soda-lime glass, water glass, molecular sieve; Perhaps other materials that can absorb and reduce lithium ion content and not introduce detrimental impurity in addition carry out purifying treatment to fused salt.

After step IX or multistep IX, the first ion stressor layers and remaining ion stressor layers have been formed at glass surface.The characteristics of the first ion stressor layers are that stress value is high, play the effect of panel first barriers such as protection electron device, household electrical appliance and the vehicles.High surface C S, bend resistance intensity, shock resistance, hardness and wear resisting property etc. have direct relation.The characteristics of all the other ion stressor layers are that the degree of depth is big, can greatly improve the long-term reliability of electron device, household electrical appliance and vehicle panel.Dark DoL has bigger tolerance to the glass surface cut, and the discreteness through tested glass intensity characterizes.

In one embodiment, adopt two kinds of schemes to carry out tempering to the lithium aluminosilicate glass, a kind of scheme is to use KNO₃(contain＜0.2mol.% Li) at 390 ℃, following exchange 4h, and a kind of in addition scheme is earlier through NaNO₃(contain＜1mol.%Li) exchange 4h down, use KNO then at 390 ℃₃(Li that contains trace＜0.2mol.%) exchanges 4h down at 400 ℃.Through measuring, the CS of first kind of sample that scheme obtains is 850MPa, and DoL is 8 microns, and the CS of second kind of sample that scheme obtains is 860MPa, and K DoL is 8 microns, and Na DoL is 168 microns.Afterwards this glass sample is carried out the test of 4 flexural strengths, the discreteness of the sample strength test that second kind of scheme obtains has only 10MPa, and the discreteness of first kind of resulting sample strength test of scheme is 62MPa.

Contriver of the present invention passes through a step and the multistep IX test discovery of a large amount of glass samples under different condition; For for the cover plate of electronic product; In order to reach ideal strength property and good reliability; The discreteness of promptly low strength test; The ratio of the first sheath thickness and all the other sheath thickness need be controlled at 1: 20＜first sheath thickness: all the other sheath thickness＜1: 2, preferable range are 1: 18＜first sheath thickness: all the other sheath thickness＜1: 5, more preferably scope is 1: 15＜first sheath thickness: all the other sheath thickness＜1: 8.

4 flexural strengths through a step or the toughened glass goods that obtain of multistep IX are higher than 550MPa, preferably are higher than 600MPa, more preferably are higher than 650MPa; Ball falling impact (132 gram steel ball) intensity can reach 50cm, preferably is higher than 60cm, more preferably is higher than 80cm.

Owing to adopt the fused salt that contains SODIUMNITRATE that suitable glass of the present invention is carried out IX in the first step after, the surface layer of glass lithium ion is gone out by exchange basically, thereby surface layer of glass has the sodium of high content.In one embodiment, the sodium oxide content of the first step exchange back glass surface is preferably greater than 18wt.%, more preferably greater than 18.5wt.% greater than 17.5wt.%.Because the grid that the less lithium ion of former cause occupies is occupied by bigger sodium ion, the surface produces stress through this IX lithium aluminosilicate glass top layer grid later, and therefore hardness improve.This hardness is higher than the sodium aluminosilicate glass that is not reinforced with same sodium content.After other follow-up reinforcements like saltpetre of process, the sodium ion on top layer is all exchanged, and it is very fine and close that the surface becomes, thereby hardness improves greatly.Because accumulative effect that repeatedly IX produced, the hardness of glass will surpass the hardness of the sodium aluminosilicate glass with analogous components after chemical enhanced.

With respect to a step ion tempering, can further improve the Vickers' hardness of the toughened glass goods that obtain through multistep IX, the Vickers' hardness of the toughened glass goods that obtain under the external force of 200g greater than 680kgf/mm², be preferably greater than 700kgf/mm², be preferably greater than 720kgf/mm especially²This means that multistep glasswork that IX obtains has better scratch resistant performance in practical application.

Toughening method of the present invention can be handled the glass that is used for other application scenario equally, electron device for example, the cover plate of notebook computer, mobile telephone etc. for example, photovoltaic panel, the base material of hard disk and thin-film solar cells etc.These cover plates and base material need keep HS and high scratch resistance in very long duration of service.

Embodiment

Glass among theembodiment 1 adopts oxide compound, oxyhydroxide and carbonate etc. to found for raw material; After weighing and mixing, mixture is put into platinum crucible, on electric furnace; Under 1550-1600 ℃, make its fusion; Be cast to then in the metal mold that is preheated to suitable temp, slowly cooling makes block glass then, afterwards under annealing temperature fine annealing to eliminate internal stress.With the glass cutting flakiness behind the fine annealing, twin polishing also obtains the glass sample of 100x60x0.7mm with the numerically-controlled machine edging then.

Glass sample adopts two-step approach to carry out chemical tempering; Wherein the mol ratio of Li: Na: K is 0.1: 99.8: 0.1 in the used fused salt of the first step; Glass sample is immersed in the fused salt,, then glass is taken out from fused salt 390 ℃ of tempering 4 hours; Be cooled to room temperature, adopt clear water to clean up and drying.Immerse then in second fused salt, wherein the mol ratio of Li: Na: K was 0.01: 0.1: 99.89,400 ℃ of following tempering 4 hours.The first step and the fused salt in second step all adopt corresponding alkali-metal nitrate salt.

After accomplishing all ion-exchange step, cleaning glass sheet sample is to remove remaining salt and to bake to carry out CS, DoL and 4 crooked tests.

The FSM6000 that adopts Orihara company to produce measures CS and K DoL.Adopt polarizing microscope that Na DoL is measured.Adopt micro Vickers that the glass Vickers' hardness is measured (measuring condition: 200 gram forces kept 10 seconds).Glass behind the tempering has the K DoL of 8 μ m and the Na DoL of 168 μ m, the bearing stress of 860MPa and 690kgf/mm²Vickers' hardness.

It is identical withembodiment 1 that glass smelting among theembodiment 2 and glass sample prepare process.Glass sample adopts a step fused salt mixt tempering, and the mol ratio of Li in the fused salt: Na: K is 0.1: 5: 95, all adopts the nitrate salt preparation, and glass sample immerses in the fused salt 410 ℃ of following tempering 4 hours.Glass behind the tempering has the K DoL of 15 μ m and the Na DoL of 136 μ m, the bearing stress of 710MPa and 670kgf/mm²Vickers' hardness.

It is identical withembodiment 1 that glass smelting among theembodiment 7 and glass sample prepare process.Glass sample is the fused salt tempering in three steps, and wherein the mol ratio of Li: Na: K is 0.1: 98.9: 1 in the used fused salt of the first step, and glass sample is immersed in the fused salt 390 ℃ of following tempering 4 hours; Then glass is taken out from first fused salt; Do not add cooling and directly immerse in second fused salt, wherein the mol ratio of Li: Na: K was 0.2: 4.8: 95,410 ℃ of following tempering 0.3 hour; Then glass is taken out from second fused salt; Do not add cooling and directly immerse in the 3rd fused salt, wherein the mol ratio of Li: Na: K was 0.02: 0.2: 99.78,420 ℃ of following tempering 4 hours.Fused salt in the first step, second step and the 3rd step all adopts corresponding alkali-metal nitrate salt preparation.Glass behind the tempering has the K DoL of 21 μ m and the Na DoL of 162 μ m, the bearing stress of 1050MPa and 710kgf/mm²Vickers' hardness.

Table 1 comprises theabove embodiments 1,embodiment 2 andembodiment 7 and other preferred embodiment, and wherein the preparation method of glass and tempering sample not is identical with embodiment 1.During multistep IX, between 2 successive steps, can wash or cleaning glass sheet sample not.

Comparative Examples

The glass ingredient of Comparative Examples 1 is identical withembodiment 1, but adopts a step high purity KNO₃The fused salt tempering is compared withembodiment 1, and its DoL significantly reduces, bearing stress, and 4 flexural strengths and surface hardness are also lower.

The glass ingredient of Comparative Examples 2 is identical withembodiment 2, but adopts a step high purity N aNO₃The fused salt tempering is compared withembodiment 2, and its DoL is approaching, but bearing stress, and 4 flexural strengths and surface hardness significantly reduce.

Comparative Examples 3 is a Sodelimesilica Glass, adopts a step high purity KNO₃The fused salt tempering, its DoL, all the lithium aluminosilicate glass than the multistep tempering is low for bearing stress, 4 flexural strengths and surface hardness.

Comparative Examples 4 is the sodium aluminosilicate glass, adopts a step high purity KNO₃The fused salt tempering, its DoL, bearing stress, surface hardness all the lithium aluminosilicate glass than the multistep tempering are low, and 4 flexural strengths are near the lithium aluminosilicate glass of multistep tempering.

Character behind composition of glass (based on the weight % of oxide compound) and the chemical tempering, for example hardness, CS, DoL and 4 flexural strengths are listed in the table 1.

Provided correlation curve among Fig. 1 about the surface hardness value of different embodiment and Comparative Examples reinforcement back glass.Test pressure is respectively 1N, 2N, 3N, 5N and 10N, respectively corresponding 100 gram forces, 200 gram forces, 300 gram forces, 500 gram forces and 1000 gram forces.Adopt the lithium aluminosilicate glass surface hardness after multistep method is strengthened to have special advantage, than the high about 3%-5% of lithium aluminosilicate glass hardness that adopts after mixing salt is strengthened, than adopting pure NaNO of a step₃Lithium aluminosilicate glass hardness after the reinforcement is high about 6%, than the high about 3%-8% of surface hardness of the sodium aluminosilicate glass after strengthening, than the about by force 13-18% of soda-lime glass after the reinforcement.This shows the performance of the brilliance aspect anti-external force scuffing of the lithium aluminosilicate glass after multistep is strengthened.

Claims

1. the tempering of a plurality of stressor layers of formation contains the method for lithium glass; Be included in and use a kind of mixing salt to carry out IX in the step, or in a plurality of steps, use different salt baths to carry out repeatedly IX, be characterised in that; After IX; Form a plurality of stressor layers on the surface of glass, bearing stress is greater than 850MPa, and total bearing stress layer depth is greater than 120 μ m.

2. the tempering of a plurality of stressor layers of formation as claimed in claim 1 contains the method for lithium glass; Be characterised in that; In multistep IX; The melting salt that uses in each step has different compositions, and described salt bath is selected from nitrate salt, carbonate, vitriol, phosphoric acid salt, oxyhydroxide, muriate, fluorochemical or its mixture.

3. the tempering of a plurality of stressor layers of formation as claimed in claim 1 contains the method for lithium glass, is characterised in that, the radius of the main alkalimetal ion that the ratio of ionic radii of the main alkalimetal ion that in arbitrary step salt bath, contains contains in a last step is big.

4. the tempering of a plurality of stressor layers of formation as claimed in claim 1 contains the method for lithium glass; Be characterised in that; Identical like the ionic radius of the main alkalimetal ion that in the salt bath of any one step, contains with the radius of main alkalimetal ion in a last step, the concentration height of the concentration ratio of main alkalimetal ion main alkalimetal ion in a last step in this step then.

5. the method that contains lithium glass like the tempering of claim 3 or a plurality of stressor layers of 4 described formation; Be characterised in that; Described salt bath only contains three kinds of alkalimetal ion A, B, C, and its ionic radius is A＜B＜C in proper order, and the mol ratio of the alkalimetal ion in the salt bath that in the end uses in step IX is A: B: C=0-5: 0-10: 90-100; Be preferably A: B: C=0-1: 0-5: 95-100 is preferably A: B: C=0-0.5: 0-1: 99-100 especially; In the end in a step at least one step before; Alkalimetal ion mol ratio in the salt bath that uses is A: B: C=0-10: 50-100: 0-3; Be preferably A: B: C=0-5: 95-100: 0-2 is preferably A: B: C=0-1: 99-100: 0-1 especially.

As the tempering of a plurality of stressor layers of each described formation of aforementioned claim 3-5 contain the method for lithium glass, be characterised in that, be selected from lithium, sodium, potassium, rubidium and/or the caesium one or more as the basic metal of metals ion.

7. contain the method for lithium glass like the tempering of a plurality of stressor layers of the described formation of aforementioned claim 3-5, be characterised in that the concentration of main alkalimetal ion in the end is higher than 95mol.% in a step salt bath, preferably is higher than 97mol.%, more preferably is higher than 99mol.%.

8. the method that contains lithium glass like the tempering of a plurality of stressor layers of the described formation of claim 3-5; Be characterised in that; Lithium concentration in any one step salt bath is lower than the lithium concentration in the last step salt bath, and wherein lithium concentration is lower than 1mol.% in last step salt bath.

9. contain the method for lithium glass like the tempering of a plurality of stressor layers of each described formation of aforementioned claim, be characterised in that, in the end adopt the fused salt that mainly contains sodium ion in a step at least one step before.

10. contain the method for lithium glass like the tempering of a plurality of stressor layers of each described formation of aforementioned claim, be characterised in that the immersion temperature of each molten salt bath is 360-450 ℃, the immersion time is 0.1-12 hour.

11. as the tempering of a plurality of stressor layers of the described formation of aforementioned claim contains the method for lithium glass, is characterised in that described multistep IX comprises two steps, three steps or four step IXs.

12. the tempering of a plurality of stressor layers of formation as claimed in claim 11 contains the method for lithium glass; Be characterised in that; In two step IXs; The concentration range of first kind of alkalimetal ion is 50-100mol.% in the first step, and second kind of alkalimetal ion concentration is 80-100mol.% in second step.

13. as the tempering of a plurality of stressor layers of the described formation of aforementioned claim 11 contains the method for lithium glass, is characterised in that under the situation of two step IXs, the first step is used and mainly contained NaNO₃Fused salt, second step used and mainly to contain KNO₃Fused salt.

14. as the tempering of a plurality of stressor layers of the described formation of aforementioned claim 1 contains the method for lithium glass; Be characterised in that; When in a step, using a kind of mixing salt IX; The mol ratio that described fused salt mixt comprises lithium, sodium and potassium metals ion, wherein Li: Na: K is 0-1: 2.5-10: 90-97.5.

15. as the tempering of a plurality of stressor layers of the described formation of aforementioned claim 1-13 contains the method for lithium glass, is characterised in that after multistep IX, bearing stress is greater than 900MPa.

16. as the tempering of a plurality of stressor layers of each described formation of aforementioned claim contains the method for lithium glass, is characterised in that after multistep IX, total bearing stress layer depth is greater than 150 μ m.

17. as the tempering of a plurality of stressor layers of each described formation of aforementioned claim contains the method for lithium glass; Be characterised in that; After multistep IX; The first stressor layers sheath degree of depth is 1: 20＜first sheath thickness with the ratio of all the other stressor layers sheath degree of depth: all the other sheath thickness＜1: 2 are preferably 1: 18＜the first sheath thickness: all the other sheath thickness＜1: 5, more preferably 1: 15＜first sheath thickness: all the other sheath thickness＜1: 8.

18. as the tempering of a plurality of stressor layers of each described formation of aforementioned claim contains the method for lithium glass, is characterised in that, after a step or multistep IX, under the test condition of 200g power and 10 seconds, the Vickers' hardness of glass surface is higher than 680kgf/mm², preferably be higher than 700kgf/mm², more preferably be higher than 720kgf/mm²

19. as the tempering of a plurality of stressor layers of each described formation of aforementioned claim contains the method for lithium glass; Be characterised in that after multistep IX, 4 flexural strengths of toughened glass goods are higher than 550MPa; Preferably be higher than 600MPa, especially preferably be higher than 650MPa.

20. as the tempering of a plurality of stressor layers of each described formation of aforementioned claim contains the method for lithium glass, is characterised in that the described lithium glass that contains has following composition:

The preferred component scope is:

Most preferably composition range is:

21. toughened glass that contains lithium with a plurality of stressor layers; Be characterised in that described glass is according to each described method preparation of aforementioned claim 1-20; Described glass, bearing stress is greater than 850MPa after IX, and total bearing stress layer depth is greater than 120 μ m.

22. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21 is characterised in that after IX, bearing stress is greater than 900MPa.

23. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21 is characterised in that after IX total bearing stress layer depth is greater than 150 μ m.

24. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21; Be characterised in that after IX; 1: 20＜first sheath thickness: all the other sheath thickness＜1: 2; Be preferably 1: 18＜the first sheath thickness: all the other sheath thickness＜1: 5, more preferably 1: 15＜first sheath thickness: all the other sheath thickness＜1: 8.

25. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21 is characterised in that after IX, under the test condition of 200g power and 10 seconds, the Vickers' hardness of glass surface is higher than 680kgf/mm², preferably be higher than 700kgf/mm², especially preferably be higher than 720kgf/mm²

26. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21 is characterised in that after IX, 4 flexural strengths of toughened glass goods are higher than 550MPa, preferably are higher than 600MPa, especially preferably are higher than 650MPa.

27. the toughened glass that contains lithium with a plurality of stressor layers as claimed in claim 21 is characterised in that the described lithium glass that contains has following composition:

The preferred component scope is:

Most preferably composition range is:

28. like each the toughened glass that contains lithium with a plurality of stressor layers of claim 21-28, in 4 buckling strengths tests, standard deviation is very little, less than 30MPa, preferably less than 20MPa, especially preferably less than 10MPa.

29. like each the toughened glass that contains lithium of claim 21-28 with a plurality of stressor layers as the purposes of cover plates such as touch pad, indicating meter, consumer-elcetronics devices, household electrical appliance, the vehicles.