Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of assay method of titanium dioxide covering power, has solved in prior art the not high and longer defect consuming time of titanium dioxide covering power assay method degree of accuracy.
Technical scheme of the present invention is:
The invention provides a kind of assay method of titanium dioxide covering power, concrete steps are:
A stirs and evenly mixs into titanium dioxide mill base by varnish and titanium pigment specimen;
B forms the brushing of titanium dioxide mill base to film respectively on blank and blackboard, air-dry under the room temperature of filming;
Blank after C measures respectively and films and the reflectivity on blackboard, try to achieve contrast ratio with the reflectivity on blackboard divided by the reflectivity on blank, with this, characterizes the covering power of titanium dioxide.
Preferably, in said method steps A, the weight ratio of varnish and titanium pigment specimen is 10: 1.
Preferably, the coating thickness forming in said method step B is consistent.
Preferably, the air-dry 0.5-6h under room temperature that films in said method step B.
The present invention also provides a kind of evaluation method of titanium dioxide covering power, and concrete steps are:
(1) measure the contrast ratio of titanium dioxide standard specimen:
Varnish is stirred and evenly mixed into titanium dioxide mill base with titanium dioxide standard specimen, respectively the brushing of titanium dioxide mill base is formed and filmed on blank and blackboard, natural air drying under the room temperature of filming; Then measure respectively blank after filming and the reflectivity on blackboard, with the reflectivity on blackboard, divided by the reflectivity on blank, try to achieve the contrast ratio of titanium dioxide standard specimen;
(2) measure the contrast ratio of titanium pigment specimen:
Varnish and titanium pigment specimen are stirred and evenly mixed into titanium dioxide mill base, respectively the brushing of titanium dioxide mill base is formed and filmed on blank and blackboard, natural air drying under the room temperature of filming; Then measure respectively blank after filming and the reflectivity on blackboard, with the reflectivity on blackboard, divided by the reflectivity on blank, try to achieve the contrast ratio of titanium pigment specimen;
(3) compare the contrast ratio of titanium pigment specimen and titanium dioxide standard specimen, if the contrast ratio of titanium pigment specimen is greater than the contrast ratio of titanium dioxide standard specimen, show that titanium pigment specimen covering power is greater than the covering power of titanium dioxide standard specimen.
Preferably, in above-mentioned evaluation method step (1), the weight ratio of varnish and titanium dioxide standard specimen sample is 10: 1, and in step (2), the weight ratio of varnish and titanium pigment specimen is 10: 1.
Preferably, above-mentioned evaluation method step (1) is consistent with the coating thickness forming in step (2).
Preferably, the air-dry 0.5-6h under room temperature that films in above-mentioned evaluation method step (1) and step (2).
Beneficial effect of the present invention:
Utilize the inventive method to measure and evaluate the covering power of titanium dioxide sample, its result degree of accuracy is higher, and easy to operation, and analytic process is effective and rapid, can be widely used in the mensuration of titanium dioxide covering power.
Embodiment
The invention provides a kind of assay method of titanium dioxide covering power, concrete steps are:
A stirs and evenly mixs into titanium dioxide mill base by varnish and titanium pigment specimen;
B forms the brushing of titanium dioxide mill base to film respectively on blank and blackboard, natural air drying under the room temperature of filming;
Blank after C measures respectively and films and the reflectivity on blackboard, try to achieve contrast ratio with the reflectivity on blackboard divided by the reflectivity on blank, with this, characterizes the covering power of titanium dioxide.
Preferably, in said method steps A, the weight ratio of varnish and titanium pigment specimen is 10: 1.
Preferably, the coating thickness forming in said method step B is consistent.
Preferably, the air-dry 0.5-6h under room temperature that films in said method step B.
The present invention also provides a kind of evaluation method of titanium dioxide covering power, and concrete steps are:
(1) measure the contrast ratio of titanium dioxide standard specimen:
Varnish is stirred and evenly mixed into titanium dioxide mill base with titanium dioxide standard specimen, respectively the brushing of titanium dioxide mill base is formed and filmed on blank and blackboard, natural air drying under the room temperature of filming; Then measure respectively blank after filming and the reflectivity on blackboard, with the reflectivity on blackboard, divided by the reflectivity on blank, try to achieve the contrast ratio of titanium dioxide standard specimen;
(2) measure the contrast ratio of titanium pigment specimen:
Varnish and titanium pigment specimen are stirred and evenly mixed into titanium dioxide mill base, respectively the brushing of titanium dioxide mill base is formed and filmed on blank and blackboard, natural air drying under the room temperature of filming; Then measure respectively blank after filming and the reflectivity on blackboard, with the reflectivity on blackboard, divided by the reflectivity on blank, try to achieve the contrast ratio of titanium pigment specimen;
(3) compare the contrast ratio of titanium pigment specimen and titanium dioxide standard specimen, if the contrast ratio of titanium pigment specimen is greater than the contrast ratio of titanium dioxide standard specimen, show that titanium pigment specimen covering power is greater than the covering power of titanium dioxide standard specimen.
Preferably, in above-mentioned evaluation method step (1), the weight ratio of varnish and titanium dioxide standard specimen sample is 10: 1, and in step (2), the weight ratio of varnish and titanium pigment specimen is 10: 1.
Preferably, above-mentioned evaluation method step (1) is consistent with the coating thickness forming in step (2).
Preferably, the air-dry 0.5-6h under room temperature that films in above-mentioned evaluation method step (1) and step (2).
In the present invention, except there being specified otherwise, covering power all refers to the covering power of titanium dioxide sample, can characterize by contrast ratio, and contrast ratio is larger, shows that its covering power is larger.Black and white plate of the present invention is hiding power chart plate.
Varnish (coating that does not contain coloring material), has another name called varnish, is to be that main film forming substance is adding the coating of solvent composition by resin.Because coating is all transparent with filming, thereby also claim clear dope.
The evaluation method of titanium dioxide covering power is specially:
1, on thick balance, take a certain amount of varnish (with drinking-water cup), then take appropriate titanium white sample, and pour in the water glass that varnish is housed, with glass bar, stir uniformly 5min; Standard specimen method for making is identical; The part by weight of varnish and titanium dioxide is 10: 1;
2, with glass bar, the mill base making is placed on the blank of black and white cardboard, standard specimen is placed in the left side, and sample is placed in the right (sample and standard specimen are substantially parallel, and have the intermittence of 2-5mm), then toward blackboard, scrapes from blank with wet film preparing device; Owing to adopting wet film preparing device, the consistency of thickness that gained is filmed;
3, cardboard is lain in a horizontal plane in indoor, natural air drying under room temperature, generally needs 0.5h-6h;
4, first measure the reflectivity of filming on white square, measure four points up and down, R averages
w; With filming in measuring reflectance black matrix, measure four points up and down again, R averages
b; Standard specimen is also measured by above-mentioned steps;
5, adopt following formula to calculate the contrast ratio (characterizing covering power with this) of filming:
R
b-reflectivity the R that films on black square plate
w-the reflectivity of filming on white square plate
Standard specimen is also pressed above formula and is calculated, then the reflectivity of sample and standard specimen is compared, and data show that more greatly covering power is better, evaluates its quality.
Below in conjunction with embodiment, the specific embodiment of the present invention is further described, does not therefore limit the present invention among described scope of embodiments.
Material and instrument
Disposable plastic water glass
Glass bar
Black and white cardboard 14cm * 20cm is upper white lower black, and cardboard requires overlay film, and to guarantee to film, sample does not permeate wet film preparing device SZQ-100 in paper
Embodiment 1
1 takes the beautiful scholar of the painting paint of 10g (with drinking-water cup) on thick balance, then the one batch of sample that adds 1gWo company to produce, and with glass bar, stirs uniformly 5min; Standard specimen method for making is identical;
2 use glass bars are placed in the mill base making on the blank of black and white cardboard, and standard specimen is placed in the left side, and sample is placed in the right (sample and standard specimen are substantially parallel, and have the intermittence of 3mm), then toward blackboard, scrapes from blank with wet film preparing device;
3 lie in a horizontal plane in cardboard indoor, and room temperature is transferred and set to 0 .5h;
4 first measure the reflectivity of filming on blank, measure four points up and down, and R averages
w; Measure filming on blackboard again, measure four points up and down, R averages
b; Standard specimen is also measured by above-mentioned steps;
The contrast ratio of gained sample and standard specimen is as shown in table 1, if the contrast ratio of sample is greater than the contrast ratio of standard specimen, shows the covering power qualified of this sample, otherwise defective.
Embodiment 2
Step, with embodiment 1, adopts two batches of samples (different from one batch of sample production time) of my company's production, and selected standard specimen is identical with embodiment standard specimen; Test comparison rate, test result is as shown in table 1.
Embodiment 3
Step, with embodiment 1, adopts three batches of samples (different with two batches of sample production times from a batch) of my company's production, and selected standard specimen is identical with embodiment standard specimen; Test comparison rate, test result is as shown in table 1; If the contrast ratio of sample is greater than the contrast ratio of deciding through consultation standard specimen, show the covering power qualified of this Lot sample, on the contrary defective.
In practical application, the inventor often combines two kinds of titanium dioxide covering powers of comparison by the inventive method and a kind of comparatively accurate ocular estimate, the ocular estimate adopting is specially: on thick balance, take the beautiful scholar of the painting paint of 10g (with drinking-water cup), the one batch of sample that adds again 1gWo company to produce, with glass bar, stir uniformly 5min, standard specimen method for making is identical; With glass bar, the mill base making is placed on the blank of black and white cardboard, standard specimen is placed in the left side, and sample is placed in the right (sample and standard specimen are substantially parallel, and have the intermittence of 2-5mm), then toward blackboard, scrapes from blank with wet film preparing device; At light, be not very dark, also, in not dazzling situation, sight line becomes 30 ° of-90 ° of angles with plate face, standard specimen and sample on observation blackboard, if sample is whiter, and light transmission rate is low, is difficult for seeing black matrix, and covering power is better than standard specimen, otherwise poorer than standard specimen; From good and bad situation, can determine following grade: be better than, be slightly better than, be not less than, elementary errors in, lower than.Adopt the method to compare titanium dioxide sample and the standard specimen of embodiment 1-3, what its comparative result recorded with employing contrast ratio method of the present invention comes to the same thing.
Comparative example
In order to verify test result of the present invention, the present invention also tests the titanium pigment specimen in above-mentioned three embodiment and the covering power of standard specimen respectively according to the method in GB 5211.17-88, be designated as comparative example 1, comparative example 2, comparative example 3, acquired results is as shown in table 2.
Table 1 adopts the inventive method to record the contrast ratio of titanium pigment specimen and standard specimen
|
Sample contrast ratio |
Standard specimen contrast ratio |
Sample covering power index |
Embodiment 1 |
71.50 |
68.35 |
Qualified |
Embodiment 2 |
63.18 |
68.35 |
Defective |
Embodiment 3 |
70.17 |
68.35 |
Qualified |
Table 2 adopts GB 5211.17-88 method to record the contrast ratio of titanium pigment specimen and standard specimen
|
Sample contrast ratio |
Standard specimen contrast ratio |
Sample covering power index |
Comparative example 1 |
68.13 |
65.36 |
Qualified |
Comparative example 2 |
60.55 |
65.36 |
Defective |
Comparative example 3 |
66.42 |
65.36 |
Qualified |
Known by contrast table 1 and table 2, adopt the inventive method to evaluate coming to the same thing of the result of titanium pigment specimen covering power (covering power that is about to sample and standard specimen compares) and the method evaluation titanium pigment specimen covering power of employing GB 5211.17-88 regulation.So in practical application, we can adopt method of the present invention to measure the contrast ratio and the contrast ratio of deciding through consultation standard specimen of the titanium pigment specimen of manufacturer production completely, both are compared, if the contrast ratio value of the sample of producing is high compared with the contrast ratio of institute's mark sample, the hiding power value that shows to produce sample is qualified, shows that this sample can apply; Otherwise be unacceptable product; And do not need to go to measure according to the comparatively complicated and method consuming time of GB 5211.17-88 regulation.