JPH01169344A - Measurement of degree of scrutch whitening - Google Patents

Abstract

PURPOSE:To make an objective data for the degree of scratch whitening, by forming a groove with an arcuate cross-section in a sample as a scratch whitening portion to measure the quantity of scattered light obtained by a dark field illumination. CONSTITUTION:A groove 10A having an arcuate cross-section with a radius 5-50mm and a depth of 0.001-1mm is formed with a cutter or the like on the surface of a synthetic resin sample 10 to produce a scratch whitening portion. Then, the sample 10 is placed on a stage 22 of a microscope device and the magnification of an objective lens 23 is so selected as to cover the groove 10A in the entire field of view of a microscope. A bright/dark field projection illumination device 24 is switched over to a dark field illumination so as to irradiate the groove 10A with light P from a light source at 45 deg.. With the irradiation of the light P, light is scattered on the groove 10A and light Q parallel with an optical axis of the objective lens 23 passes through the objective lens 23 to be detected with an optoelectro transducer 31 within a camera 30. A current value of the optoelectro transducer 31 is inputted into an arithmetic means 33 through an A/D converter 32 to compute an exposure time, being shown on a display means 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a scratch whitening degree measuring method for measuring the degree of whitening that occurs when the surface of a synthetic resin material is scratched.

[Conventional technology]

In recent years, synthetic resin materials have been widely used in the automobile field, light electrical field, and the like. Molded products made of synthetic resin, especially polyolefin materials such as polyethylene,
It has the disadvantage that when its surface is scratched, it turns white (hereinafter referred to as scratch whitening), and this scratch whitening phenomenon significantly reduces the commercial value. Therefore, conventionally, for product control purposes, scratch whitening phenomenon determination has been carried out by scratching a sample made of a synthetic resin material and measuring the degree of whitening.

Conventional scratch whitening measurement methods include the following.

First, as shown in FIG. 6, a grained flat sample 50 placed on a base 51 is scratched with a jagged portion on its circumferential surface using a 100 yen coin 5S on which a weight 54 with a constant load is applied. There is a system (conventional example 1) in which the level of whitening of the scratched mark is visually judged and ranked. The flat sample 50 thus obtained was scratched with a diamond needle 56 whose load on the sample 50 was varied depending on the number of weights 54, etc., and the relationship between the load at this time and the depth of the scratch on the sample 50 (visual evaluation) was determined. There is a method (conventional example (■)) in which a graph is plotted and the scratched and whitened area is measured from the initial slope and yield value on this graph. Furthermore, the eighth
As shown in the figure, a scratched portion is formed by reciprocating a sandpaper 57 on which a weight 54 with a constant load is applied to the grained surface of a flat sample 50 with a grained surface. There is a method (conventional example (2)) in which the color difference (ΔE) from a part without scratches is measured using a color difference meter.

[Problem that the invention seeks to solve]

However, in the conventional example (2), because the sensory test involves visual judgment of the degree of whitening, there is a problem in that it is not possible to obtain average quantified data for the directional scratch-whitening phenomenon. Further, although the conventional example (2) is suitable for the 5 scratch resistance test, there is a problem in that a correlation between the scratch resistance and the degree of whitening determined by a graph cannot be obtained. Furthermore, in conventional example (■), the visual whitening degree and the color difference (ΔE”
) cannot be accurately correlated with color difference (ΔE”
), the problem is that light enters the color difference meter used from a certain direction and that the scratches have directionality, so different values appear depending on the direction of incidence, making it impossible to ensure the reliability of the measurement. be. Furthermore, conventional example (2) also has the problem that minute scratches cannot be evaluated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for measuring scratches and whitening by which quantitative data can be obtained when measuring scratches and whitening of any scratches formed on a sample.

[Means for solving problems]

The present invention involves forming a groove with an arc-shaped cross section with a radius of 5 to 50 m and a depth of 0.001 to 1 inch using a cutter or the like on the surface of a synthetic resin sample to form a scratched and whitened area. Light is irradiated towards the object using dark-field illumination, the irradiated light is diffusely reflected, and the component parallel to the optical axis of the objective lens used in dark-field illumination is received, and the amount of light received is For example, the scratched and whitened area is measured by finding it as the exposure time of a camera attached to a dark field illumination device.

[Effect]

As a result, the present invention can be applied to a sample with a radius of 50 mm as a scratched and whitened portion by appropriately selecting the shape of the tip of the cutter, etc.
~50Il111, a groove with an arcuate cross section and a depth of 0.001 to 1 m is formed, and the amount of diffusely reflected light obtained by dark field illumination is measured to obtain objective data on the scratched and whitened portion. Therefore, in the present invention, since a brightness that is correlated with the degree of visual whitening can be obtained, appropriate measurement of the scratched and whitened area can be performed using this light amount as a reference for the scratched and whitened area data.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 5.

First, the apparatus used in this example will be explained.

FIG. 1 shows an outline of the scratch tester (taper scratch tester manufactured by Toyo Seiki Co., Ltd.) used in this example. In FIG. 1, a turntable 2 is rotatably provided on a base l, and this turntable 2 is
0.5 to 5 depending on the motor 3 installed in the base 1
It is designed to rotate at a rotation speed of rpm. Here, a flat synthetic resin sample 10 is mounted on the turntable 2 via a shaft 2A.

Further, an arm 4 is rotatably attached to the base 1 via a column 5. In the center of this arm 4 there are 2
weights 6 (only one is shown in the figure) are attached, and these weights 6 apply a total test load of 50 to 10,100 O to the arm 4.

A cutter 7 whose position in the longitudinal direction of the arm is adjustable is attached to the tip of the arm 4, and this cutter 7 has the following features:
As shown in FIGS. 2(A) and 2(B), the front surface of the tip is arcuate with a radius of 5 to 50 mm, and the side surface of the tip is sharpened. Here, the shearing angle of the cutter 7 with respect to the sample 10 is 10 to 40 degrees. As a result, when the turntable 2 is rotated, as shown in FIG. This groove 10A is formed into a ring shape of cm.
A scratched and whitened area is formed.

FIG. 4 shows an outline of the measuring instruments used in this example. This equipment is composed of a polarizing microscope device 20 (BH-2 manufactured by Olympus Corporation), an attached camera 30 equipped with this microscope device 20, and a display means 40 connected to this camera 30.

The polarizing microscope device 20 is attached to a stand 21 and includes a stage 22 on which the sample 10 is placed,
Above this stage 22, there is an objective lens 23, a bright/dark field epi-illumination device 24 (BH2-RLA) that switches between bright field illumination and dark field illumination with a knob 29, and a lens barrel 26 equipped with an eyepiece 25. are arranged on the same axis.

The bright/dark field epi-illumination device 24 includes a dark-field cue and a universal illumination device, and this universal illumination device includes an epi-illumination lamp house 26 (BH2-MLSH
), and a long-life lambda logen lamp (12V, 50WHAL) provided inside this epi-illumination lamp house 27. This halogen lamp is connected to a power source via a transformer 28. The objective lens 23 includes:
In addition to bright field lenses, dark field lenses (NeoSpl
an), and there are 5x, 10x, 20x, and 50x dark field lenses, which are used for sample 1.
The size of the groove (scratch and whitening portion) 10A formed in the groove 0 is selected as appropriate. As a result, as shown in FIG. 5, the dark-field illumination allows light P from a halogen lamp (not shown) to be transmitted at an angle of 45 degrees by a ring-shaped condenser (not shown) provided on the outer periphery of the objective lens 23. This light P is diffusely reflected by the scratched and whitened portion 10A, and the light Q parallel to the optical axis of the objective lens 23 is transmitted through the objective lens 23. It is designed to receive light.

The camera 30 has an automatic exposure function, and has an AS
It is provided with input means 35 (see FIG. 5) for inputting data for setting photographing conditions such as A sensitivity, film characteristic correction, and exposure correction based on sample distribution. As shown in the block diagram of FIG. 5, the inside of this camera 30 includes a photoelectric conversion element 31 that converts the amount of light Q reflected by the scratched and whitened portion 10A into a current value; An A/D converter 32 converts the converted analog current into a digital signal, and a signal from the A/D converter 32 is input to the input means 35.
It also includes calculation means 33 for calculating exposure time based on data such as SA sensitivity.

The display means 40 is connected to the calculation means 33, and the exposure time calculated by the calculation means 36 is digitally displayed by the display means 40. On this occasion,
An amplifier may be provided between the photoelectric conversion element 31 and the A/D converter 32, if necessary.

Next, a method for measuring the degree of scratch whitening according to the present example using the above-mentioned apparatus will be explained.

- White Hinoe First, a scratched and whitened portion 10A is formed on the sample 10 using a scratch testing machine.

For this purpose, the sample 1 is placed on the turntable 2 via the shaft 2A.
0, and then adjust the load amount of the weight 6 and the position of the weight 6 with respect to the arm 4 to adjust the amount of test load applied to the sample 10 (50 to 10100O, preferably 100 to 800O).
gf). After that, the position of the cutter 6 with respect to the arm 4, specifically the shear angle with respect to the sample 10, is adjusted to 1
Adjust the distance between the center of rotation of the sample 10 and the cutter 7 to 0 to 40 degrees, preferably 15 to 30 degrees, and rotate the turntable 2 by the motor 3 without making the tip of the cutter 6 contact the sample 10. A ring-shaped groove (scratch whitening part) 10A having an arcuate cross section with a radius of 5 to 50 m, preferably 10 to 40 m, and a depth of 0.001 to 1 square inch is formed on the sample 10.

・White vinyl After that, the groove (scratched and whitened part) 1 formed in the sample 10 by the microscope device 20, camera 30 and display means 40
Measure the scratched and whitened area of 0A.

For this purpose, the sample 10 is placed on the stage 22 of the microscope device 20 from the turntable 2, and the magnification of the objective lens 23 is selected so that the groove 10A formed on the sample 10 fits within the entire field of view when observed with the microscope 20. .

Then, input the shadow conditions of the camera into the input means 35 of the camera 30, for example, input the data of ASA sensitivity -1°O, film characteristic correction -4, and exposure correction based on sample distribution -1, and Pinch the dark field epi-illumination device 24
9 to switch to dark field illumination, groove (scratch whitening part) 1
Light P is irradiated from the light source at 0A at an angle of 45 degrees. Here, the light intensity of the light source is adjusted by a slider type transformer 28, but this slider type! It! Since the fl accuracy is poor, the light intensity is adjusted using a reference scratched sample whose scratched and whitened portion is known.

When the light P is irradiated, the light is diffusely reflected by the groove (scratched and whitened portion) 10A, and among this diffusely reflected light, light Q parallel to the optical axis of the objective lens 23 passes through the objective lens 23 and is reflected by the camera. It is detected by the photoelectric conversion element 31 in 30. Then, the amount of light is converted into a current value by this photoelectric conversion element 31,
The current value is input to the calculation means 33 via the A/D converter 32. The calculation means 33 calculates the exposure time using the digitized current value signal and data such as ASA sensitivity inputted from the input means 35, and this calculated value is digitally displayed by the display means 40.

Furthermore, using the above-mentioned apparatus, it is also possible to measure the degree of susceptibility to scratches simultaneously with or separately from the above-mentioned measurement of the scratched and whitened areas. For this purpose, the line width of the groove 10A formed in the sample 10 is evaluated. Specifically, a load of 40 m was applied to the sample 10 using a cutter 7 with a radius of 30 m in front of the tip.
If the line width is 2ms or more when set to 0gf,
The degree of vulnerability can be evaluated as high.

According to this embodiment, by appropriately selecting the shape of the tip of the cutter 6, the sample 10 has a radius of 5 to 50 mm.
A groove 10A having an arcuate cross section and a depth of 0.001 to 1 m can be formed, and with such a groove OA, a uniform scratched and whitened portion suitable for highly accurate quantification can be obtained.

Moreover, if the amount of diffusely reflected light is determined as the exposure time of the camera 30, the scattered light Q from the groove (scratched and whitened area) 10A and the brightness of the material itself of the scratched and whitened area are reflected, so this exposure time It is possible to obtain a correlation between the degree of whitening calculated as , and the degree of visual whitening, and to accurately quantify the damaged and whitened area. Furthermore, even before whitening occurs, the degree of fragility can be measured by evaluating the line width of the flawed area. Furthermore, in this embodiment, the microscope device 2
Since the exposure time is calculated using the camera 30 attached to the camera 30, it is possible to simplify the equipment required for measurement.

In addition, in the above embodiment, the groove 1 formed as the scratched and whitened part
Although the groove 0A is ring-shaped, the groove 10A formed in the sample 10 according to the present invention may have a linear shape.If the groove 10A is linear, when a plastic injection molded product is used as the sample 10 Since the injection molded product has MD and TD (resin injection direction and direction perpendicular to the injection direction), the degree of whitening in these directions can be accurately determined by forming linear grooves in the MD and TD force directions. can be measured. Further, the exposure time may be displayed digitally as in the embodiment described above, or may be displayed analogously.Furthermore, in the present invention, in addition to determining the amount of diffusely reflected light Q as the exposure time, it can also be determined as another value. However, if it is determined as an exposure time as in the above embodiment, the attached camera 30 can be used, so that the measurement equipment can be made into a square element as described above.

〔Effect of the invention〕

According to the present invention as described above, there is an effect that quantified data can be obtained when measuring the scratched and whitened portion of the groove formed in the sample.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a scratch tester used in an embodiment of the present invention, FIG. 2 shows the shape of the tip of the cutter of the scratch tester, and (A) is a front view; B) is a side view. Figure 3 is a plan view of the sample with scratched and whitened areas;
The figure is a schematic diagram of the measuring instruments used in the above example,
FIG. 5 is a block diagram of the measuring instruments, and FIGS. 6 to 8 are schematic configuration diagrams showing conventional examples. 7... Kanta, 10... Sample, IOA... Groove, 2
0... Polarizing microscope device, 23... Objective lens, 30
...Camera, Q...Diffuse reflected light.

Claims (2)

[Claims] (1) A groove with an arcuate cross section with a radius of 5 to 50 mm and a depth of 0.001 to 1 mm is formed on the surface of a synthetic resin sample to form a scratched and whitened area, and a dark field is directed toward the scratched and whitened area. Light is irradiated with an illumination device, the irradiated light is diffusely reflected, the component of this diffusely reflected light in the direction parallel to the optical axis of the objective lens used in dark field illumination is received, and the amount of this received light is determined. A method for measuring the degree of scratch whitening, characterized by: (2) The method for measuring the degree of scratch whitening according to claim 1, characterized in that the amount of the received light is determined as an exposure time of a camera attached to a dark field illumination device.