Test method for rapidly identifying high-temperature and high-humidity stripes of polaroid

Abstract

The invention discloses a test method for rapidly identifying high-temperature and high-humidity stripes of a polaroid. The method comprises the following steps: preparing a sample: fixing the polaroid of which a release film is torn off at the middle position of an iron sheet; aging the polaroid: tearing off a protective film of the polaroid fixed on the iron sheet, putting the polaroid into a high-temperature and high-humidity environment box, and standing for a period of time; and optical performance testing: taking the aged polaroid out of the environment box, testing the optical performance of the aged polaroid by using a JASCO V-7100 spectrophotometer, recording data, and calculating an A400 value. According to the invention, whether the polaroid has a stripe risk after high-temperature and high-humidity durability can be judged, the problem of high-temperature and high-humidity stripes of the product at a client can be effectively prevented, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polarizers, and in particular to a testing method for quickly identifying high-temperature and high-humidity stripes in polarizers. Background Art

[0002] With the rapid development of display technology, LCD products have been widely used in people's daily life and work, from large-size TVs to small-size watches, bracelets and other smart wearable products. In recent years, the market demand has become rich and diverse, and the demand has also increased accordingly.

[0003] A liquid crystal display (LCD) consists of a liquid crystal display (LCD) panel and a polarizing plate attached to the LCD panel. The polarizing plate typically comprises a polarizing film, an upper protective layer, a lower protective layer, a pressure-sensitive adhesive, and a release film. The polarizing film, upper protective layer, and lower protective layer are bonded together using a UV adhesive or polyvinyl alcohol adhesive. The polarizing film is made from a polyvinyl alcohol (PVA) film dyed with a dichroic substance and then uniaxially stretched and oriented.

[0004] Currently, polarizer production technologies are categorized by the PVA film stretching process: dry and wet methods. Dry polarizer production involves stretching PVA film in a steam environment with specific temperature and humidity conditions. However, this process is limited in its uniformity during stretching, making it less commonly used in actual production. Wet polarizer production involves dyeing and stretching the PVA film in a liquid with a specific ratio. Currently, polarizer manufacturers primarily utilize wet stretching technology. PVA film dyeing methods can be categorized into two main types: dye-based and iodine-based. Iodine dyeing uses iodine and potassium iodide as dichroic media during the dyeing and stretching process to impart polarized light to the polarizer film. This dyeing method offers the advantage of easily producing polarizers with high transmittance and high polarization.

[0005] Currently, iodine dyeing is the primary method for producing polarizers. Rolls are used to laminate the rolls, but the quality of the resulting polarizers varies widely. For example, to determine the polarizer's performance in high-temperature and high-humidity conditions, whether streaks may appear, leading to poor display quality or even fading and failure, requires testing the polarizer's resistance to high-temperature and high-humidity conditions, a process known as high-temperature and high-humidity durability testing.

[0006] Currently, the main method for testing polarizer streaks at high temperatures and high humidity is through durability testing. This method involves preparing the polarizer according to the specified requirements and placing it in a high-temperature, high-humidity chamber at 60°C / 90% RH. After 500 hours, the polarizer streaks are observed and the degree of streaking and fading is determined. This method is time-consuming and inefficient.

[0007] Therefore, it is necessary to develop a test method for quickly identifying high-temperature and high-humidity stripes on polarizers to overcome the shortcomings of the existing technology. Summary of the Invention

[0008] The main purpose of the present invention is to propose a testing method for quickly identifying high-temperature and high-humidity streaks in polarizers, aiming to quickly identify high-temperature and high-humidity streaks in polarizers, improve product yield, quickly identify quality risks, and avoid them in advance.

[0009] To achieve the above object, the present invention provides a method for quickly identifying high-temperature and high-humidity streaks on polarizers, the method comprising the following steps:

[0010] Step S10, sample preparation:

[0011] (1) Sample cutting: cutting polarizer;

[0012] (2) Remove the release film of the polarizer: tear off the release film of the polarizer;

[0013] (3) Fixing the polarizer: Fix the polarizer with the release film removed in the middle of the iron sheet;

[0014] Step S20, polarizer aging: the polarizer fixed on the iron sheet is placed in a high temperature and high humidity environment box after the protective film is removed and placed for a period of time, wherein the temperature and humidity of the environment box are 70°C / 95%RH for 15 to 17 hours;

[0015] Step S30, optical performance test: the aged polarizer is taken out of the environmental chamber, and the optical performance after aging is tested using a JASCO V-7100 spectrophotometer, and the data is recorded and the A400 value is calculated.

[0016] A further technical solution of the present invention is that in step S10, the size of the cut polarizer is 35 mm×40 mm.

[0017] A further technical solution of the present invention is that the placement time in step S20 is 16 hours.

[0018] A further technical solution of the present invention is that, in step S30, the test time is to complete the test within 15 minutes after taking it out of the environmental chamber.

[0019] A further technical solution of the present invention is that, in step S30, the step of calculating the value of A400 includes:

[0020] The absorbance A400 value at 400nm is calculated based on the relationship between absorbance and transmittance. The A400 value is used to determine whether there is a risk of streaking after the polarizer is tested at high temperature and high humidity. The absorbance and transmittance formula is: absorbance A = -log1 0 (transmittance T).

[0021] The beneficial effects of the test method for quickly identifying high-temperature and high-humidity streaks on polarizers of the present invention are:

[0022] The present invention adopts the above technical solution: first, the polarizer is cut, the release film is torn off, and then it is attached to the middle position of the iron sheet, and the iron sheet with the polarizer is placed in a high-temperature and high-humidity environment box for aging for 16 hours, and then taken out. The optical performance test is quickly completed within 15 minutes, and the A400 value is calculated. The A400 value of the product can be quickly measured within 17 hours. The size of the A400 value can be used to determine whether there is a risk of streaks after the polarizer's high-temperature and high-humidity durability. It can effectively prevent the high-temperature and high-humidity streak problem from occurring in the product at the customer end, thereby improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] Figure 1 The figure is a flow chart of a preferred embodiment of a test method for rapidly identifying high-temperature and high-humidity streaks on a polarizer according to the present invention.

[0025] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] This invention proposes a method for rapidly identifying high-temperature, high-humidity streaks in polarizers. The method employs a technical solution: cutting the polarizer to an appropriate size, removing the release film, and then attaching it to the center of an iron sheet. The polarizer protective film is then removed. The iron sheet with the polarizer is then aged in an HSL-10KA high-temperature, high-humidity chamber. A JASCO V-7100 spectrophotometer is then used to measure the optical properties after high-temperature baking, such as the luminous crossed nitric oxide (NiCO) transmittance (Tc400) at 400 nm. The absorbance at 400 nm, A400, is then calculated using the absorbance-transmittance formula (A = -log10 (transmittance T). This A400 value can be used to determine whether the polarizer is at risk of streaking after high-temperature, high-humidity durability testing. This method can rapidly determine whether a polarizer is at risk of streaking after high-temperature, high-humidity durability testing within 17 hours, improving testing efficiency.

[0028] like Figure 1 As shown, a preferred embodiment of the test method for quickly identifying high-temperature and high-humidity streaks on polarizers of the present invention includes the following steps:

[0029] Step S10, sample preparation:

[0030] (1) Sample cutting: cutting polarizer;

[0031] (2) Removing the release film from the polarizer: Use masking tape to stick the prepared polarizer from the end of the release film and tear off the release film of the polarizer;

[0032] (3) Fixing the polarizer: Fix the polarizer with the release film removed in the middle of the iron sheet;

[0033] Step S20, polarizer aging: the polarizer fixed on the iron sheet is placed in a high temperature and high humidity environment box after the protective film is removed and placed for a period of time, wherein the temperature and humidity of the environment box are 70°C / 95%RH for 15 to 17 hours;

[0034] Step S30, optical performance test: the aged polarizer is taken out of the environmental chamber, and the optical performance after aging is tested using a JASCO V-7100 spectrophotometer, and the data is recorded and the A400 value is calculated.

[0035] In this embodiment, in step S10, the size of the cut polarizer is preferably 35 mm × 40 mm. Of course, in other embodiments, the polarizer can also be cut into a suitable size based on actual experience.

[0036] In this embodiment, the placement time in step S20 is preferably 16 hours.

[0037] In this embodiment, in step S30, the test time is to complete the test within 15 minutes after taking out from the environmental chamber.

[0038] In this embodiment, in step S30, the step of calculating the value of A400 includes:

[0039] The absorbance A400 value at 400nm is calculated based on the relationship between absorbance and transmittance. The A400 value is used to determine whether there is a risk of streaking after the polarizer is tested at high temperature and high humidity. The absorbance and transmittance formula is: absorbance A = -log1 0 (transmittance T).

[0040] The following further describes in detail the testing method for quickly identifying high-temperature and high-humidity streaks on a polarizer according to the present invention.

[0041] Example 1: The polarizer was cut to a size of 35 mm × 40 mm. After removing the release film, the polarizer was attached to the middle of the iron sheet. The polarizer protective film was also removed. The iron sheet with the polarizer was placed in a high temperature and high humidity chamber HSL-10KA at a temperature and humidity environment of 70°C / 95% RH. After standing for 16 hours, the optical properties after high temperature and high humidity aging were tested using a JASCO V-7100 spectrophotometer. The test was completed within 15 minutes, and the luminous crossed Ni coltransmittance (Tc400) at 400 nm was recorded. Then, the absorbance A at 400 nm was converted to the absorbance A400 value using the relationship between absorbance and transmittance, absorbance A = -log10 (transmittance T), and recorded.

[0042] Comparative Example 1:

[0043] Cut the polarizer to a size of 190mm×270mm, remove the release film, and stick it in the middle of an A4 glass. Remove the polarizer protective film, and place the glass with the polarizer in a high-temperature and high-humidity chamber (HSL-10KA) at 60°C / 90%RH. After standing for 500 hours, take it out and let it cool for 30 minutes. Then, match the aged polarizer with the unaged polarizer orthogonally, turn on the backlight, use a filter to observe the streaks, and make a record.

[0044] The comparison results are shown in Table 1 below:

[0045] Table 1

[0046]

[0047] Evaluation Criteria:

[0048] ◎: no streaks;

[0049] Δ: faint streaks;

[0050] ○: obvious streaks;

[0051] As shown in Table 1, according to the present method, the A400 value is greater than 2.7, and the polarizer has no streaks, which is consistent with the results of the conventional test method.

[0052] In summary, the beneficial effects of the test method for quickly identifying high-temperature and high-humidity streaks on polarizers of the present invention are:

[0053] The present invention adopts the above technical solution: first, the polarizer is cut, the release film is torn off, and then it is attached to the middle position of the iron sheet, and the iron sheet with the polarizer is placed in a high-temperature and high-humidity environment box for aging for 16 hours, and then taken out. The optical performance test is quickly completed within 15 minutes, and the A400 value is calculated. The A400 value of the product can be quickly measured within 17 hours. The size of the A400 value can be used to determine whether there is a risk of streaks after the polarizer's high-temperature and high-humidity durability. It can effectively prevent the high-temperature and high-humidity streak problem from occurring in the product at the customer end, thereby improving product quality.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for quickly identifying high-temperature and high-humidity streaks on polarizers, characterized in that: The method comprises the following steps: Step S10, sample preparation: (1) Sample cutting: cutting polarizer; (2) Remove the release film of the polarizer: tear off the release film of the polarizer; (3) Fixing the polarizer: Fix the polarizer with the release film removed in the middle of the iron sheet; Step S20, polarizer aging: placing the polarizer fixed on the iron sheet in a high-temperature and high-humidity environmental chamber for a period of time, wherein the temperature and humidity of the environmental chamber are 70°C / 95% RH and the placement time is 15 to 17 hours; Step S30, optical performance test: the aged polarizer is taken out of the environmental chamber, and the optical performance after aging is tested using a JASCOV-7100 spectrophotometer, and the data is recorded and the A400 value is calculated.

2. The method for quickly identifying high-temperature and high-humidity streaks on polarizers according to claim 1, characterized in that: In step S10 , the size of the cut polarizer is 35 mm×40 mm.

3. The method for quickly identifying high-temperature and high-humidity streaks on polarizers according to claim 1, wherein: The placement time in step S20 is 16 hours.

4. The method for quickly identifying high-temperature and high-humidity streaks on polarizers according to claim 1, wherein: In step S30, the test time is to complete the test within 15 minutes after taking it out of the environmental chamber.

5. The method for quickly identifying high-temperature and high-humidity streaks on polarizers according to claim 1, wherein: In step S30, the step of calculating the value of A400 includes: The absorbance A400 value at 400nm is calculated based on the relationship between absorbance and transmittance. The A400 value is used to determine whether there is a risk of streaking after the polarizer is subjected to high-temperature and high-humidity durability. The absorbance and transmittance formula is: absorbance A = -log10 (transmittance T).

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