A method for identifying the resistance of polyurethane synthetic leather to damp heat aging

Abstract

This application relates to the technical field of polyurethane synthetic leather, and particularly to a method for identifying the resistance of polyurethane synthetic leather to damp heat aging. The method for identifying the resistance of polyurethane synthetic leather to damp heat aging provided by this application includes the following steps: cutting the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples; exposing the surface of the polyurethane synthetic leather samples to an alkaline mist environment for aging; judging whether the polyurethane synthetic leather to be tested is a qualified product according to the changes in the surface stickiness, texture clarity, and abrasion value of the aged polyurethane synthetic leather samples. The method provided by this application can not only accurately identify the quality of the damp heat resistance of automotive polyurethane materials, but also greatly reduce the single test cost and equipment investment cost, and the identification result is accurate.

Description

Technical Field

[0001] This application relates to the technical field of polyurethane synthetic leather, and particularly relates to a method for identifying the resistance of polyurethane synthetic leather to damp heat aging. Background Art

[0002] Polyurethane synthetic leather is usually composed of a polyurethane coating (automotive leather includes a dense layer and a foaming layer) and a base fabric. Broadly speaking, the base fabric can be polyester fabric and ultra-fine fiber base fabric. Polyurethane synthetic leather using polyester base fabric is usually called PU leather, and polyurethane synthetic leather using ultra-fine fiber base fabric is called ultra-fine fiber leather. Compared with traditional PVC artificial leather, polyurethane synthetic leather materials have the characteristics of high perception, high wear resistance, and high durability, and are widely used in automotive seats, door trim panels, instrument panels, and sub-instrument areas. The design and selection of polyurethane materials usually take into account both performance and cost. Automotive polyurethane synthetic leather in the automotive market is usually composed of a surface layer, a foaming layer, a polyurethane adhesive, and a base fabric layer. Usually, high-durability polyurethane raw materials are selected for the surface layer coating, and ordinary polyurethane raw materials are selected for the foaming layer and the adhesive layer. Polyurethane materials contain easily hydrolyzable groups such as ester groups, urethane groups, and urea groups. The performance of automotive polyurethane synthetic leather varies, and there is a risk of failure due to damp heat aging during long-term use. Therefore, polyurethane synthetic leather materials must pass strict damp heat aging tests before they can be applied to automotive products.

[0003] Different layers of automotive polyurethane synthetic leather use polyurethane raw materials with different aging resistance gradients. Existing damp heat aging tests have the disadvantages of long verification cycles, high test costs, and inaccurate results. Therefore, finding a method to quickly and accurately verify the aging resistance of automotive polyurethane synthetic leather so that it can represent the durability of the material on the whole vehicle to a certain extent has become a difficult point in the industry. Summary of the Invention

[0004] The embodiments of this application provide a method for identifying the resistance of polyurethane synthetic leather to damp heat aging to solve the problems in the related art that the damp heat aging test of polyurethane synthetic leather has a long verification cycle, high test costs, and inaccurate results.

[0005] In a first aspect, this application provides a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, including the following steps:

[0006] Cut the polyurethane synthetic leather to be tested to obtain a polyurethane synthetic leather sample;

[0007] Expose the surface of the polyurethane synthetic leather sample to an alkaline mist environment for aging;

[0008] Judge whether the polyurethane synthetic leather to be tested is a qualified product according to the surface stickiness, texture clarity, and wear value change of the aged polyurethane synthetic leather sample.

[0009] In some embodiments, the process of determining whether the polyurethane synthetic leather to be tested is a qualified product is as follows: when the polyurethane synthetic leather sample after aging simultaneously meets the conditions that the surface is not sticky or slightly sticky, the texture has no change or slight change, and the abrasion value is not more than 85 mg, then the polyurethane synthetic leather to be tested is a qualified product; when the polyurethane synthetic leather sample after aging does not simultaneously meet the conditions that the surface is slightly sticky, the texture has slight change, and the abrasion value is not more than 85 mg, then the polyurethane synthetic leather to be tested is a defective product.

[0010] In some embodiments, the alkaline mist environment is provided by an alkaline mist generator storing an alkaline solution.

[0011] In some embodiments, the alkaline solution is sodium hydroxide or potassium hydroxide solution.

[0012] In some embodiments, the mass concentration of the alkaline solution is 10%-30%.

[0013] In some embodiments, the temperature of the alkaline solution is 50-80 °C.

[0014] In some embodiments, the surface of the polyurethane synthetic leather sample is exposed to the alkaline mist environment for aging for 24-48 h.

[0015] In some embodiments, the edges of the surface of the polyurethane synthetic leather sample are sealed to prevent the alkaline mist from penetrating through the cross-section to the intermediate layer of the polyurethane synthetic leather sample during the test.

[0016] In some embodiments, the polyurethane synthetic leather sample is placed in a closed environment.

[0017] In some embodiments, the abrasion value of the polyurethane synthetic leather sample is tested according to QB / T 2726.

[0018] The method provided by this application can not only accurately identify the quality of the moisture and heat resistance of automotive polyurethane materials, but also greatly reduce the single test cost and equipment investment cost, and the identification result is accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic flowchart of the method for identifying the moisture and heat aging resistance of polyurethane synthetic leather provided by the embodiments of this application;

[0021] Figure 2 It is a schematic structural diagram of the test chamber used in Embodiment 1 of this application;

[0022] Figure 3 Schematic diagram of the internal structure of the test chamber used in Embodiment 1 of the present application. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0024] The embodiments of the present application provide a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, which can solve the problems of long verification period, high test cost and inaccurate results in the damp heat aging test of polyurethane synthetic leather in the related art.

[0025] Figure 1 Schematic flow chart of the method for identifying the resistance of polyurethane synthetic leather to damp heat aging provided by the embodiments of the present application. Refer to Figure 1 , the method provided by the present application includes the following steps:

[0026] Step S101: Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0027] Step S102: Expose the surface of the polyurethane synthetic leather sample to an alkali mist environment for aging for 24 - 48 h; the alkali mist environment is provided by an alkali mist generator storing an alkali solution, the alkali solution is sodium hydroxide or potassium hydroxide solution, the mass concentration of the alkali solution is 10% - 30%, and the temperature of the alkali solution is 50 - 80 °C.

[0028] Step S103: Judge whether the polyurethane synthetic leather to be tested is a qualified product according to the surface stickiness degree, texture clarity and wear value change of the aged polyurethane synthetic leather sample; when the aged polyurethane synthetic leather sample simultaneously meets the conditions that the surface has no stickiness or slight stickiness, the texture has no change or slight change, and the wear value is not greater than 85 mg, the polyurethane synthetic leather to be tested is a qualified product; when the aged polyurethane synthetic leather sample does not simultaneously meet the conditions of slight surface stickiness, slight texture change and wear value not greater than 85 mg, the polyurethane synthetic leather to be tested is a defective product.

[0029] The wear value is tested according to QB / T 2726, and the test conditions are CS10 / 1000g / 2000 revolutions.

[0030] The following will detail the method for identifying the resistance of polyurethane synthetic leather to damp heat aging provided by the present application with reference to embodiments and comparative examples.

[0031] Eight types of automotive polyurethane synthetic leathers supplied by mainstream suppliers in the market were selected (samples 1 to 8 were provided by the following material suppliers respectively: Best, Amway, Ruigao, Nan Ya, Shilian, Huafeng, Huayang, and Shangke), and different wet-heat aging methods were used to identify the wet-heat aging resistance of the polyurethane synthetic leathers, and the differences between different identification methods were compared.

[0032] Comparative Example 1:

[0033] The test method is: put the polyurethane synthetic leather material in a climate environment box for aging at 85℃95%RH1344h. After the test, evaluate whether the material meets the requirements based on whether the surface is shiny, pinholes, and changes in wear resistance.

[0034] Comparative Example 2:

[0035] The test method is: soak the polyurethane synthetic leather in sodium hydroxide solution, and observe whether the material peels or delaminates after a period of time.

[0036] Embodiment 1:

[0037] Embodiment 1 provides a method for identifying the wet heat aging resistance of polyurethane synthetic leather, comprising the following steps:

[0038] Cutting the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0039] Fix the polyurethane synthetic leather sample on the Figure 2 In the polyurethane synthetic leather sample placement area 1 shown in the figure, after the polyurethane synthetic leather sample is clamped and fixed, the contact edge between the clamping part and the polyurethane synthetic leather sample is sealed with adhesive tape to prevent alkaline mist from penetrating through the cross section to the middle layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution placed in the test box is 80°C; the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 10%; the aging time of the polyurethane synthetic leather is 48h.

[0040] The clamping piece used in Example 1 is a square or other shaped plane structure, with a hollow center, so that the surface of the sample can be exposed after clamping the sample. The four edges of the clamping piece have a certain width and can be Figure 2 The locking mechanism (not shown) arranged on the polyurethane synthetic leather sample placement area 1 locks the four edges.

[0041] The structural diagram of the test box used in Example 1 is shown in Figure 2 and Figure 3 , Figure 2 In the figure, 1 indicates the polyurethane synthetic leather sample placement area, 2 indicates the alkali solution storage area, 3 indicates the pull ring, Figure 3Among them, 4 represents an alkali mist generator. The test chamber is a hollow structure, and two polyurethane synthetic leather sample placement areas are provided on the test chamber. Then, at least two polyurethane synthetic leather samples can be placed in one test chamber. The alkali mist generator or ultrasonic generator is placed at the bottom of the test chamber. The polyurethane synthetic leather sample placement area is inclined on the test chamber. When the polyurethane synthetic leather sample is clamped in the polyurethane synthetic leather sample placement area, the polyurethane synthetic leather sample is inclined above the alkali mist generator or ultrasonic generator. After the polyurethane synthetic leather sample is fixed in the polyurethane synthetic leather sample placement area, the polyurethane synthetic leather sample placement area is buckled through the pull ring provided on the surface of the polyurethane synthetic leather sample placement area, that is, the polyurethane synthetic leather sample is placed in a closed environment.

[0042] Verify the heat and humidity resistance of the above 8 types of automotive polyurethane synthetic leather synchronously according to the test methods of Comparative Example 1 and Comparative Example 2. The results are shown in Table 1.

[0043] Table 1: Test Results of Example 1

[0044]

[0045]

[0046] Example 2:

[0047] Example 2 provides a method for identifying the heat and humidity aging resistance of polyurethane synthetic leather, including the following steps:

[0048] Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0049] Fix the polyurethane synthetic leather sample in the test chamber through a clamping member, and the edge of the surface of the polyurethane synthetic leather sample is strictly sealed to prevent the alkali mist from penetrating through the cross-section to the intermediate layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution placed in the test chamber is 60 °C; the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 20%; the aging time of the polyurethane synthetic leather is 36 h.

[0050] The test chamber used in Example 2 is the same as that in Example 1.

[0051] Verify the heat and humidity resistance of the above 8 types of automotive polyurethane synthetic leather synchronously according to the test methods of Comparative Example 1 and Comparative Example 2. The results are shown in Table 2.

[0052] Table 2: Test Results of Example 2

[0053]

[0054]

[0055] Example 3:

[0056] Example 3 provides a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, including the following steps:

[0057] Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0058] Fix the polyurethane synthetic leather sample in the test chamber through a clamping member, and strictly seal the edges of the surface of the polyurethane synthetic leather sample to prevent the alkali mist from penetrating through the cross-section to the middle layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution placed in the test chamber is 70 °C; the alkali solution is an aqueous sodium hydroxide solution, and the mass concentration of sodium hydroxide is 20%; the aging time of the polyurethane synthetic leather is 48 h.

[0059] The test chamber used in Example 3 is the same as that in Example 1.

[0060] Verify the damp heat resistance of the above 8 types of automotive polyurethane synthetic leather synchronously according to the test methods of Comparative Example 1 and Comparative Example 2, and the results are shown in Table 3.

[0061] Table 3: Test results of Example 3

[0062]

[0063] Example 4:

[0064] Example 4 provides a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, including the following steps:

[0065] Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0066] Fix the polyurethane synthetic leather sample in the test chamber through a clamping member, and strictly seal the edges of the surface of the polyurethane synthetic leather sample to prevent the alkali mist from penetrating through the cross-section to the middle layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution placed in the test chamber is 80 °C; the alkali solution is an aqueous sodium hydroxide solution, and the mass concentration of sodium hydroxide is 30%; the aging time of the polyurethane synthetic leather is 24 h.

[0067] The test chamber used in Example 4 is the same as that in Example 1.

[0068] Verify the damp heat resistance of the above 8 types of automotive polyurethane synthetic leather synchronously according to the test methods of Comparative Example 1 and Comparative Example 2, and the results are shown in Table 4.

[0069] Table 4: Test results of Example 4

[0070]

[0071] Example 5:

[0072] Example 5 provides a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, including the following steps:

[0073] Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0074] Fix the polyurethane synthetic leather sample in the test chamber through a clamping member, and strictly seal the edge of the surface of the polyurethane synthetic leather sample to prevent the alkali mist from penetrating through the cross-section to the intermediate layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution in the test chamber is 80 °C; the selected alkaline solution is sodium hydroxide aqueous solution, and the mass concentration of sodium hydroxide is 30%; the aging time of the polyurethane synthetic leather is 48 h.

[0075] The test chamber used in Example 5 is the same as that in Example 1.

[0076] Verify the resistance of the above 8 types of automotive polyurethane synthetic leather to damp heat synchronously according to the test methods of Comparative Example 1 and Comparative Example 2, and the results are shown in Table 5.

[0077] Table 5: Test results of Example 5

[0078]

[0079]

[0080] Example 6:

[0081] Example 6 provides a method for identifying the resistance of polyurethane synthetic leather to damp heat aging, including the following steps:

[0082] Cut the polyurethane synthetic leather to be tested to obtain polyurethane synthetic leather samples of a certain size;

[0083] Fix the polyurethane synthetic leather sample in the test chamber through a clamping member, and strictly seal the edge of the surface of the polyurethane synthetic leather sample to prevent the alkali mist from penetrating through the cross-section to the intermediate layer of the polyurethane synthetic leather sample during the test; the temperature of the alkali solution in the test chamber is 50 °C; the selected alkaline solution is sodium hydroxide aqueous solution, and the mass concentration of sodium hydroxide is 15%; the aging time of the polyurethane synthetic leather is 48 h.

[0084] The test chamber used in Example 6 is the same as that in Example 1.

[0085] Verify the resistance of the above 8 types of automotive polyurethane synthetic leather to damp heat synchronously according to the test methods of Comparative Example 1 and Comparative Example 2, and the results are shown in Table 6.

[0086] Table 6: Test results of Example 6

[0087]

[0088] The detection results obtained by using the detection method of Comparative Example 1 were used as the true damp heat aging levels of the 8 materials, and the compliance percentages of the detection results of Examples 1-6 and Comparative Example 2 with those of Comparative Example 1 were statistically calculated. At the same time, the equipment investment and costs of the test schemes were calculated. The results are shown in Table 6.

[0089] Table 6: Comparison results of equipment investment costs

[0090]

[0091]

[0092] It can be seen from the data in Table 6 that the accuracy of identifying the damp heat resistance of polyurethane synthetic leather in Examples 1-5 is consistent with that of the method in Comparative Example 1, with high accuracy; the detection efficiency is 28-56 times that of Comparative Example 1; the single detection cost is greatly reduced compared with Comparative Example 1; the equipment is relatively simple and the investment cost is greatly reduced. The method for detecting the damp heat resistance of polyurethane synthetic leather commonly used in shoe materials and clothing has poor detection accuracy for automotive polyurethane synthetic leather.

[0093] In the description of this specification, the description referring to terms such as "one embodiment / way", "some embodiments / ways", "example", "specific example" or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments / ways or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0094] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element. In this application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0095] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for identifying the resistance of polyurethane synthetic leather to damp heat aging, characterized in that, It includes the following steps: Cut the polyurethane synthetic leather to be tested to obtain a polyurethane synthetic leather sample; Expose the surface of the polyurethane synthetic leather sample to an alkaline mist environment for aging for 24 - 48 h; Judge whether the polyurethane synthetic leather to be tested is a qualified product according to the surface stickiness degree, texture clarity and wear value change of the aged polyurethane synthetic leather sample; Among them, the alkaline mist environment is provided by an alkaline mist generator storing an alkaline solution; The alkaline solution is sodium hydroxide or potassium hydroxide solution; The mass concentration of the alkaline solution is 10% - 30%; The temperature of the alkaline solution is 50 - 80 °C.

2. The method for identifying the heat and humidity aging resistance of polyurethane synthetic leather according to claim 1, wherein The process of judging whether the polyurethane synthetic leather to be tested is a qualified product is as follows: when the aged polyurethane synthetic leather sample simultaneously meets the conditions of slight surface stickiness, slight texture change, and wear value not greater than 85 mg, the polyurethane synthetic leather to be tested is a qualified product; when the aged polyurethane synthetic leather sample does not simultaneously meet the conditions of slight surface stickiness, slight texture change, and wear value not greater than 85 mg, the polyurethane synthetic leather to be tested is a defective product.

3. The method for identifying the resistance of polyurethane synthetic leather to damp heat aging according to claim 1, characterized in that, Seal the edge of the surface of the polyurethane synthetic leather sample.

4. The method for identifying the resistance of polyurethane synthetic leather to damp heat aging according to claim 1, wherein, Place the polyurethane synthetic leather sample in a closed environment.

5. The method for identifying the resistance of polyurethane synthetic leather to damp heat aging according to claim 1, characterized in that, Test the wear value of the polyurethane synthetic leather sample according to QB / T 2726.

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