Method for testing permeability of water-based resin emulsion

Abstract

The invention relates to the technical field of resin emulsion performance testing methods, and particularly discloses a method for testing the permeability of a water-based resin emulsion. The preparation method comprises the following steps: diluting a water-based resin emulsion with water to obtain a diluted emulsion; the method comprises the following steps: stacking and fixing a plurality of layers of flat base materials, arranging a water penetration test area and a diluted emulsion penetration test area which have the same area on the surfaces of the base materials, and respectively adding water and diluted emulsion which have the same mass for penetration, and calculating the relative permeability c of the water-based resin emulsion according to the number n0 of the base material layers permeated by the water and the number n of the base material layers bonded after the diluted emulsion permeates. According to the method, the permeability of the water-based resin emulsion can be intuitively compared according to the number of layers of the base materials permeated and bonded by the diluted emulsion by utilizing the cohesiveness of the diluted emulsion and the looseness and porosity of the multi-layer base materials, the method is simple and convenient to operate, the permeability of the water-based resin emulsion can be quickly, simply and accurately evaluated, and the method is suitable for large-scale popularization and application. And a user can conveniently design and verify the formula of paint such as primer.

Description

Technical Field

[0001] The invention relates to the technical field of performance testing methods for resin emulsions, and in particular to a testing method for the penetration performance of water-based resin emulsions. Background Art

[0002] Primer for interior and exterior walls of buildings refers to the paint that is directly applied to the base layer (cement mortar substrate, putty layer or other base materials) of the interior and exterior walls of buildings during the coating project; film-forming primer refers to the primer for interior and exterior walls of buildings that can form a protective film on the surface of the base layer to block saline-alkali substances in the base layer from entering the coating layer; penetrating primer refers to the primer for interior and exterior walls of buildings that can penetrate into the base layer, block saline-alkali substances in the base layer from entering the coating layer or strengthen the strength of the base layer. The film appearance, water permeability, reinforcement performance and other indicators of film-forming primers and penetrating primers are different, and there are certain differences in actual application scenarios. The permeability of the primer affects the performance of the primer. The good permeability of the primer can improve the adhesion and waterproof performance of the primer to a certain extent, so as to provide better sealing for the next coating, prevent the water in the board from evaporating under high temperature exposure, and cause the coating and decorative panel to fall off, or the coating to blister.

[0003] Primer is mainly composed of resin emulsion, water, pigments and fillers and additives. Resin emulsion is generally a water-based resin emulsion, which is composed of acrylic copolymer, water, emulsifier and additives. Resin emulsion plays a film-forming and bonding role in interior and exterior wall coatings. The permeability and film-forming properties of primer mainly depend on the permeability and film-forming properties of resin emulsion. Resin emulsion has both film-forming and permeability, and different types of resin emulsions have different focuses. At present, whether a certain emulsion is suitable for penetrating primer or film-forming primer is mainly recommended by suppliers. Suppliers mainly judge the permeability of resin emulsions based on factors such as particle size distribution, solid content and actual application conditions, and often do not provide detailed test reports and recommendation basis. This is not convenient for users of resin emulsions to make independent choices, and is not conducive to the design of primer formulas with resin emulsions.

[0004] The current evaluation of primer permeability in the field of architectural coatings mainly adopts the following methods: adding equal amounts of color paste to different samples, applying the same mass of samples on the same sample by brushing, dipping or spraying, and keeping the test area the same, observing the drying rate of the sample, the generation of bubbles, or observing the penetration depth of the color paste in the sample after cutting the sample. Since the penetration depth of the resin emulsion is low and the difference between samples is not obvious, this method is difficult to quantitatively evaluate the permeability of the resin emulsion; and the penetration path of the color paste and the resin emulsion is different, the penetration depth of the color paste cannot directly represent the penetration depth of the resin emulsion. Therefore, there is an urgent need for a test method that can directly reflect the penetration performance of water-based resin emulsions. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for testing the permeability of an aqueous resin emulsion, which uses the relative permeability of the aqueous resin emulsion on a substrate to water as an index to quantitatively characterize the permeability of the aqueous resin emulsion, and utilizes the adhesion of the diluted emulsion and the loose porosity of the multi-layer substrate to intuitively compare the permeability of the aqueous resin emulsion according to the number of substrate layers bonded by the diluted emulsion, and the evaluation index is easy to be quantified, quickly and accurately.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: Diluting the aqueous resin emulsion with water to obtain a diluted emulsion; the diluted emulsion has a solid content of 14% to 18% and a viscosity of ≤50 mPa·s; A plurality of flat substrates are stacked and fixed, and a water penetration test area and a diluted emulsion penetration test area of ​​the same area are set on the surface of the substrate. Water and the diluted emulsion of the same mass are added for penetration, respectively. According to the number of substrate layers n0 penetrated by the water and the number of substrate layers n bonded after the diluted emulsion penetrates, the relative permeability c of the water-based resin emulsion is calculated using Formula 1: Formula 1; Wherein, the substrate comprises at least one of paper or non-woven fabric, and the number of water-permeable substrate layers n0≥10 layers.

[0007] Compared with the prior art, the test method for the permeability of water-based resin emulsion provided by the present invention adjusts water-based resin emulsions with different permeabilities to diluted emulsions with the same solid content and equivalent viscosity, which is conducive to the smooth progress of subsequent permeability tests and ensures the accuracy of test results. When the initial test mass and test area remain the same, the penetration of these diluted emulsions on the stacked fixed multi-layer flat substrates is different. The penetration principle is as follows: due to the different latex particle sizes and particle size distributions of different water-based resin emulsions, after the diluted emulsion is added to the test area on the surface of the substrate, some latex particles with smaller particle sizes penetrate into the substrate due to the capillary action of the substrate pores, and even pass through the tightly stacked multi-layer substrates, and latex particles with larger particle sizes and small particle size latex particles that are difficult to penetrate into the substrate remain on the surface of the substrate; water-based resin emulsions (including diluted emulsions) have adhesiveness and high adhesive strength. After the diluted emulsion is cured, the substrates penetrated by the latex particles will be bonded together. The relative permeability of the water-based resin emulsion relative to water is calculated according to the number of substrate layers bonded after the diluted emulsion penetrates (cures), and the permeability of different water-based resin emulsions can be preliminarily compared. The more substrate layers are bonded after the diluted emulsion is infiltrated and cured, the higher the relative permeability and the stronger the permeability. This method is easy to operate and can quickly, simply and accurately evaluate the permeability of water-based resin emulsions without the need for expensive instruments, making it easier for users of water-based resin emulsions to design and verify the formulation of primers and other coatings.

[0008] In the present invention, a specific substrate can be permeated by water and diluted emulsion in multiple layers. Paper and non-woven fabrics are respectively non-homogeneous porous structures, which are interwoven by a large number of fibers. The capillary channels inside them are of different shapes, tortuous and varied, and extend in all directions, making them good permeable substrates. Compared with a whole piece of putty or other loose substrates, the evaluation index is more quantifiable. The present invention uses paper or non-woven fabrics that have a certain permeability to water as the substrate (n0≥10 layers), which can effectively improve the difference between samples and further ensure the accuracy of the test results.

[0009] In the present invention, some aqueous resin emulsions have a higher solid content (such as 45%), are viscous pastes, and have poor fluidity, while some aqueous resin emulsions have a lower viscosity and better fluidity. When designing the formula of the primer, the solid content is generally 14% to 25% to meet the performance requirements and construction requirements of the primer. The present invention has found through a large number of experiments that if the solid content of the diluted emulsion is too low, the penetration of water and the penetration of the diluted emulsion are easily separated, the area of ​​water seepage is larger, and the adhesion of the diluted emulsion is reduced; if the solid content is too high, some of the diluted emulsions with larger viscosity penetrate fewer substrate layers, resulting in difficulty in comparing and distinguishing between samples. Considering that the viscous diluted emulsion is more difficult to penetrate into the substrate, in order to reduce the differences between samples, the present invention adjusts the viscosity of the diluted emulsion to a lower state in order to shorten the penetration time and be more in line with the actual application of the primer.

[0010] In addition, if different water-based resin emulsions are tested at the same time to distinguish the size of the permeability between them, a method of controlling variables (such as limiting the solid content of the diluted emulsion to the same fixed value of 14% to 18%) can be adopted to make the test result more accurate. For the viscosity of the diluted emulsion, the present invention does not make special requirements. As long as the solid content of the diluted emulsion meets 14% to 18% and the viscosity is ≤ 50mPa·s, it can be understood that the viscosity of the diluted emulsion is equivalent. For example, the solid content of the diluted emulsion is 14% to 18%, and the viscosity can be 5mPa·s, 10mPa·s, 15mPa·s, 20mPa·s, 25mPa·s, 30mPa·s, 35mPa·s, 45mPa·s or 50mPa·s.

[0011] It should be noted that in the “multi-layer, flat substrate”, “multi-layer” means a sufficient number of substrates, which cannot be completely penetrated by water or diluted emulsion; “flat” means horizontal placement and flat surface, no visible gaps between substrates, and no bending or folding; “stacked and fixed” means that the multi-layer substrates are tightly combined to ensure that the sample (water and diluted emulsion) can be effectively penetrated, for example, each test area on the surface of the substrate is compacted and fixed with weights or other means, and the pressure is ≥500Pa (the upper limit of the pressure is limited to the substrate cannot remain flat). For example, a sufficient number of substrates are fixed on a hard plate with weights or dovetail clamps. The hard plate used for support is non-absorbent plastic or other materials. If there are fixed objects that affect the horizontal placement of the hard plate, pads should be used under the hard plate to ensure that the substrate is placed horizontally.

[0012] For example, before the penetration test, the substrate needs to be placed under standard conditions (23℃±2℃, 50%±5%) for more than 48 hours to check whether the substrate has any defects such as damage and dust, so as to ensure that the water absorption rate of the substrate is uniform and stable and easy to test.

[0013] Preferably, the base material has a gram weight of 30 g / m 2 ~100g / m 2 .

[0014] Further preferably, the paper comprises at least one of newsprint or filter paper.

[0015] The grammage of newsprint is 45g / m 2 ~51g / m 2 , newsprint of GB / T 1910-2015 standard can be used; the weight of filter paper is 76g / m 2 ~84g / m 2 , chemical analysis filter paper with unified standard of GB / T 1914-2017 can be used.

[0016] Preferably, the test area on the surface of the substrate is circular.

[0017] Preferably, the area of ​​the test area on the substrate surface is 20 cm 2 ~40cm 2 .

[0018] The present invention has found through a large number of experiments that a circular test area is more conducive to sample penetration; if the area of ​​the test area is less than 20cm 2 , the penetration area is too small and the test results are difficult to compare; if the area of ​​the test area is > 40cm 2 The substrate is easily infiltrated and deformed by the sample, which is not conducive to the close fitting between the substrates, thereby blocking the penetration channel of the sample.

[0019] Further preferably, a round tube tool having a bottom area equal to that of the test area is vertically fixed to the surface of the substrate to ensure that the water and the diluted emulsion can cover the test area and achieve a wetting effect.

[0020] For example, the material of the round tube tool is plastic or other non-absorbent and non-deformable material.

[0021] More preferably, the vertical fixing method comprises the following steps: The bottom end of the round tube tool is coated with the melted adhesive, and is vertically pressed on the surface of the substrate, and the adhesive is cooled and solidified.

[0022] More preferably, the adhesive comprises rosin and paraffin in a mass ratio of (0.8-1.2):1.

[0023] The present invention utilizes the melting and solidification characteristics of rosin and paraffin wax to seal the gap between the bottom end of the round tube tool and the substrate, thereby ensuring the shape and area of ​​the test area on the surface of the substrate. The specific adhesive has a fast curing speed, good sealing performance, and is easy to remove, which is convenient for removing the round tube tool and observing it closely after the test.

[0024] Preferably, the minimum gap between two adjacent test areas on the surface of the substrate is ≥5 cm, and the minimum distance from the edge of the test area on the surface of the substrate to the edge of the substrate is ≥2.5 cm.

[0025] For example, the adding method includes uniform dropwise addition to ensure that the sample has no bubbles and can horizontally wet the substrate.

[0026] Preferably, the water is deionized water.

[0027] Preferably, the amount of water and diluted emulsion added is 1 kg / m 2 ~5kg / m 2 .

[0028] In the present invention, the sample in the test area must cover all the test areas and achieve the effect of infiltration. In order to prevent the permeability difference between samples from being unclear due to too little test amount, or the test error caused by different sample areas in the test area, the minimum amount of sample added is the amount of sample added that can cover all the test areas and achieve the effect of infiltration (1kg / m 2 ), the maximum value is the amount of coating that still remains on the surface of the sample 30 minutes after the start of the test (5kg / m 2 ).

[0029] Preferably, the infiltration temperature is 21° C. to 25° C., and the humidity is 45% to 55%.

[0030] Preferably, the water penetration time is 25 min to 35 min.

[0031] Preferably, the penetration time of the diluted emulsion is 20h~28h.

[0032] The present invention has found through a large number of tests that if the water penetration time is too short, the penetration is not complete, the end point is not reached, and the number of substrate layers penetrated is small; if the penetration time is too long, the water will evaporate, and the number of substrate layers penetrated may be reduced, thereby affecting the test results. After the diluted emulsion penetrates for 25min~35min, the penetration basically reaches the end point, but at this time the substrate is not bonded by the diluted emulsion, and only a wet mark can be seen. After 20h~28h of penetration, the diluted emulsion is basically completely dried and solidified.

[0033] Preferably, the number of substrate layers n0 penetrated by water is an average value after multiple tests, and the number of substrate layers n bonded after the aqueous resin emulsion penetrates is an average value after multiple tests.

[0034] In the water penetration test, the penetration of water on the substrate can be clearly observed with the naked eye. The color of the substrate will change after being penetrated by water, so the naked eye is selected for judgment. If the color change of the substrate cannot be observed with the naked eye, other methods can also be used to help judge, such as touching it with your hands or judging with absorbent paper.

[0035] In the penetration test of the diluted emulsion, the present invention uses the number of substrate layers that can be bonded as the basis for calculating n. It should be noted that even if the bonding points of the bottom one or two layers of the substrate after penetration are relatively small and the bonding force is relatively weak, and it is easy to be peeled off during the paper turning process, it is still calculated in n; the substrate that is only infiltrated but cannot be bonded is not calculated in n. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is an example diagram of water and diluted emulsion in the present invention after penetrating a multi-layer substrate; wherein, Figure a is an example diagram of water and diluted emulsion in the multi-layer substrate, and Figure b is an example diagram of water and diluted emulsion in the multi-layer substrate after penetrating a multi-layer substrate to separate the substrate between layers; Figure 2 The photographs are of the penetration conditions of 10 kinds of diluted emulsions in Example 1 of the present invention; Figure 3 The photographs are of the penetration conditions of 10 kinds of diluted emulsions in Comparative Example 1 of the present invention; Figure 4 The photographs are of the penetration conditions of 10 samples in Comparative Example 4 of the present invention; Figure 5 These are photos of the penetration conditions of 10 samples in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] In the present invention, materials not specifically specified are all commercially available products. The present invention uses 10 kinds of water-based resin emulsions for testing, which are respectively recorded as 1# to 10#, and 1# to 10# water-based resin emulsions are RS-635, RS-64, XG-2216, XG-2217, RS-368, HC-1506A, ROSF-168, RS-308, RS-982F and XG-2000.

[0039] In the present invention, before the penetration test, the substrate needs to be placed under standard conditions (23°C ± 2°C, 50% ± 5%) for more than 48 hours to check whether the substrate has any defects such as damage and dust, so as to ensure that the water absorption rate of the substrate is uniform and stable and easy to test.

[0040] Example 1 This embodiment provides a method for testing the permeability of an aqueous resin emulsion, comprising the following steps: 50 layers of flat substrate (weight 45g / m 2 The newsprint paper was fixed on a horizontal hard plate with multiple dovetail clips and a 500 g weight. The bottom ends of 11 round tube tools with an inner diameter of 6.2 cm were coated with melted adhesive (rosin and paraffin with a mass ratio of 1:1) and pressed vertically on the surface of the substrate. After the adhesive cooled and solidified, 11 tubes with an area of ​​about 30 cm were obtained. 2 In the circular test area, the minimum gap between two adjacent cylindrical tools is ≥5cm, and the minimum distance from the edge of the cylindrical tool to the edge of the substrate is ≥2.5cm.

[0041] Deionized water was added to dilute the 10 kinds of water-based resin emulsions respectively until the solid content was 15%, thereby obtaining diluted emulsions, the viscosity values ​​of which are shown in Table 1.

[0042] Add 10g of deionized water or 10g of diluted emulsion (the amount added is 3.33kg / m 2 ), stir evenly to ensure that the sample has no bubbles and horizontally infiltrates the substrate, and perform penetration under standard conditions. After 30 minutes, observe the number of substrate layers n0=29 layers penetrated by water. After 24 hours, observe the number of substrate layers n bonded by the 10 kinds of diluted emulsions after penetration. Repeat each group of tests 5 times and calculate the average value. Formula 1 is used to calculate the relative permeability c of the 10 kinds of water-based resin emulsions. The test results are shown in Tables 1 and Figure 2 shown.

[0043] Table 1 Permeability test results of different samples in Example 1

[0044] Example 2 This embodiment provides a method for testing the permeability of an aqueous resin emulsion, comprising the following steps: 50 layers of flat substrate (weight 84g / m 2 The filter paper was fixed on a horizontal hard plate with multiple dovetail clips and a 500 g weight. The bottom ends of 11 round tube tools with an inner diameter of 5.1 cm were coated with a melted adhesive (rosin and paraffin with a mass ratio of 0.8:1) and pressed vertically on the surface of the substrate. After the adhesive cooled and solidified, 11 tubes with an area of ​​about 20 cm were obtained. 2 In the circular test area, the minimum gap between two adjacent cylindrical tools is ≥5cm, and the minimum distance from the edge of the cylindrical tool to the edge of the substrate is ≥2.5cm.

[0045] Deionized water was added to dilute the 10 kinds of water-based resin emulsions respectively until the solid content was 14%, thereby obtaining diluted emulsions, the viscosity values ​​of which are shown in Table 2.

[0046] Add 2g of deionized water or 2g of diluted emulsion (the amount added is 1kg / m 2 ), stir evenly to ensure that the sample has no bubbles and horizontally infiltrates the substrate, penetrate under standard conditions, observe the number of substrate layers n0=20 layers penetrated by water after 35 minutes, observe the number of substrate layers n bonded after 10 kinds of diluted emulsions penetrate after 21 hours, repeat each group of tests 5 times, and calculate the average value. Formula 1 is used to calculate the relative permeability c of 10 kinds of water-based resin emulsions, and the test results are shown in Table 2.

[0047] Table 2 Permeability test results of different samples in Example 2

[0048] Example 3 This embodiment provides a method for measuring the permeability of an aqueous resin emulsion, comprising the following steps: Put 50 layers of flat substrate (weight 50g / m 2 The newsprint paper (in accordance with GB / T 1910-2015) was fixed on a horizontal hard plate with multiple dovetail clips and a 500g weight. The bottom ends of 11 round tube tools with an inner diameter of 7.0cm were coated with melted adhesive (rosin and paraffin with a mass ratio of 1.2:1) and pressed vertically on the surface of the substrate. After the adhesive cooled and solidified, 11 tubes with an area of ​​about 38cm were obtained. 2 In the circular test area, the minimum gap between two adjacent cylindrical tools is ≥5cm, and the minimum distance from the edge of the cylindrical tool to the edge of the substrate is ≥2.5cm.

[0049] Deionized water was added to dilute the 10 kinds of water-based resin emulsions respectively until the solid content was 18%, thereby obtaining diluted emulsions, the viscosity values ​​of which are shown in Table 3.

[0050] Add 19g of deionized water or 19g of diluted emulsion (the amount added is 5kg / m 2 ), stir evenly to ensure that the sample has no bubbles and horizontally infiltrates the substrate, penetrate under standard conditions, observe the number of substrate layers n0=33 layers penetrated by water after 25 minutes, observe the number of substrate layers n bonded after 10 kinds of diluted emulsions penetrate after 28 hours, repeat each group of tests 5 times, and calculate the average value. Formula 1 is used to calculate the relative permeability c of 10 kinds of water-based resin emulsions, and the test results are shown in Table 3.

[0051] Table 3 Permeability test results of different samples in Example 3

[0052] Comparative Example 1 This comparative example provides a method for testing the penetration performance of a water-based resin emulsion, which is similar to Example 1, except that the substrate is replaced with a loose porous substrate formed by mixing fine gray particles (Carbon Technology Group Co., Ltd., HXNZ) and deionized water in a mass ratio of 2:1 and curing for 72 hours, and the thickness of the substrate is 15 mm. Specifically, the following steps are included: The bottom ends of 11 round tube tools with an inner diameter of 6.2 cm were coated with melted adhesive (rosin and paraffin with a mass ratio of 1:1) and pressed vertically on the surface of the substrate. After the adhesive cooled and solidified, 11 tubes with an area of ​​about 30 cm were obtained. 2 The circular test area was plotted with the cylinder tool positioned approximately in the center of each substrate.

[0053] Deionized water was added to dilute the 10 kinds of water-based resin emulsions respectively until the solid content was 15%, thereby obtaining diluted emulsions, the viscosity values ​​of which are shown in Table 4.

[0054] Add 10g of diluted emulsion evenly to each cylindrical tool (the amount added is 3.33kg / m 2 ), stir evenly to ensure that the sample has no bubbles and horizontally infiltrates the substrate, penetrate under standard conditions, and measure the penetration depth of different samples in the substrate after 24 hours (cut the substrate in half and soak it with deionized water to show the penetration depth of the water-based resin emulsion, see Figure 3 , the penetration depth of 5 points was tested at equal intervals and the average value was taken). The test results are shown in Table 4.

[0055] Comparative Example 2 This comparative example provides a test method for the penetration performance of a water-based resin emulsion, which is similar to Example 1, except that the substrate is replaced with a loose porous substrate formed by mixing and curing a cement mixture (10wt% 425 cement, 45wt% 40-80 mesh snowflake white, 45wt% 80-120 mesh snowflake white) and deionized water at a mass ratio of 2:1 for 72 hours, and the thickness of the substrate is 50 mm. The specific steps are the same as those in Comparative Example 1 and are not repeated here. The test results are shown in Table 4.

[0056] Table 4 Permeability test results of different samples in Comparative Examples 1-2

[0057] It can be seen from Tables 1 to 4 that the penetration rules of the 10 water-based resin emulsions in newsprint, filter paper, putty, and cement substrates are basically consistent, 7# to 9# water-based resin emulsions have better penetration performance, 1#, 4# to 6# water-based resin emulsions have medium penetration performance, and 2# to 3# and 10# water-based resin emulsions have weaker penetration performance. Compared with the putty and cement substrates of Comparative Examples 1 and 2, Examples 1 to 3 use paper as the substrate, the operation steps are simpler and faster, and the evaluation indicators are easier to quantify.

[0058] Comparative Example 3 This comparative example provides a method for measuring the permeability of an aqueous resin emulsion, which is similar to Example 1, except that: the substrate is replaced with a substrate having a gram weight of 70 g / m 2 The other conditions are the same as those in Example 1 and will not be described in detail.

[0059] The penetration was carried out under standard conditions. After 30 minutes, the number of substrate layers n0=1 layer penetrated by water was observed. After 24 hours, the number of substrate layers n bonded after the penetration of 10 kinds of diluted emulsions was observed. Each group of tests was repeated 5 times and the average value was calculated. The test results are shown in Table 5.

[0060] Comparative Example 4 This comparative example provides a method for measuring the permeability of an aqueous resin emulsion, which is similar to Example 1, except that the aqueous resin emulsion is not diluted and is directly tested using the undiluted aqueous resin emulsion. The remaining operations and conditions are the same as those in Example 1 and will not be described in detail. The test results are shown in Tables 5 and Figure 4 As shown (n0=29 layers).

[0061] Table 5 Permeability test results of different samples in Comparative Examples 3-4

[0062] It can be seen from Table 1 and Table 5 that, compared with Example 1, Comparative Example 3 uses multifunctional office paper as the substrate, and has poor penetration effect on water and diluted emulsion, and the resulting error is also large; compared with Example 1, Comparative Example 4 does not dilute the aqueous resin emulsion, and the fluidity of some aqueous resin emulsions is poor, and the number of substrate layers penetrated by the aqueous resin emulsion is small, while the fluidity of some aqueous resin emulsions is good, and the number of substrate layers penetrated by the aqueous resin emulsion is large, resulting in large errors between samples.

[0063] Comparative Example 5 This comparative example provides a method for measuring the penetration performance of water-based resin emulsions, which is similar to Example 1, except that: the test samples are prepared by adding 2 wt% of different types of color pastes (iron red, iron yellow, carbon black, medium yellow, orange) and 4 wt% of different types of color pastes (iron red, iron yellow, carbon black, medium yellow, orange) to the diluted 2# water-based resin emulsion, and are named samples 11# to 20# in sequence. The remaining operations and conditions are the same as those in Example 1 and will not be described in detail. After 24 hours, the number of substrate layers m penetrated by the 10 types of water-based resin emulsions containing color pastes is observed. i Each test was repeated 5 times and the average value was calculated. The test results are shown in Table 6 and Figure 5 shown.

[0064] Table 6 Permeability test results of different samples in Comparative Example 5

[0065] It can be seen from Table 6 that when different proportions and types of color pastes are added to the same diluted water-based resin emulsion, the amount of paper penetrated by the color paste is completely different, which shows that the color paste cannot replace the penetration of the water-based resin emulsion.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for testing the penetration performance of a water-based resin emulsion, characterized in that: The following steps are involved: Diluting the aqueous resin emulsion with water to obtain a diluted emulsion; the diluted emulsion has a solid content of 14% to 18% and a viscosity of ≤50 mPa·s; A plurality of flat substrates are stacked and fixed, and a water penetration test area and a diluted emulsion penetration test area of ​​the same area are set on the surface of the substrate. Water and the diluted emulsion of the same mass are added for penetration, respectively. According to the number of substrate layers n0 penetrated by the water and the number of substrate layers n bonded after the diluted emulsion penetrates, the relative permeability c of the water-based resin emulsion is calculated using Formula 1: Formula 1; Wherein, the substrate comprises at least one of paper or non-woven fabric, and the number of water-permeable substrate layers n0≥10 layers.

2. The method for testing the penetration performance of an aqueous resin emulsion according to claim 1, wherein: The base material has a grammage of 30 g / m 2 ~100g / m 2 .

3. The method for testing the permeability of an aqueous resin emulsion as claimed in claim 2, characterized in that: The paper includes at least one of newsprint or filter paper.

4. The method for testing the permeability of an aqueous resin emulsion according to claim 1, wherein: The test area on the substrate surface is circular with an area of ​​20 cm 2 ~40cm 2 .

5. The method for testing the penetration performance of an aqueous resin emulsion as claimed in claim 4, characterized in that: A round tube tool with a bottom area equal to that of the test area is vertically fixed to the surface of the substrate to ensure that the water and the diluted emulsion can cover the test area and achieve a wetting effect.

6. The method for testing the permeability of an aqueous resin emulsion according to claim 5, characterized in that: The vertical fixing method comprises the following steps: The bottom end of the round tube tool is coated with the melted adhesive, and is vertically pressed on the surface of the substrate, and the adhesive is cooled and solidified.

7. The method for testing the permeability of an aqueous resin emulsion according to claim 6, wherein: The adhesive comprises rosin and paraffin in a mass ratio of (0.8-1.2):

1.

8. The method for testing the penetration performance of an aqueous resin emulsion according to any one of claims 1 to 7, characterized in that: The minimum gap between two adjacent test areas on the substrate surface is ≥5 cm, and the minimum distance from the edge of the test area on the substrate surface to the edge of the substrate is ≥2.5 cm.

9. The method for testing the penetration performance of an aqueous resin emulsion according to any one of claims 1 to 7, characterized in that: The amount of water and diluted emulsion added is 1kg / m 2 ~5kg / m 2 .

10. The method for testing the penetration performance of an aqueous resin emulsion according to any one of claims 1 to 7, characterized in that: The infiltration temperature is 21°C to 25°C, and the humidity is 45% to 55%; The penetration time of the water is 25 min to 35 min, and the penetration time of the diluted emulsion is 20 h to 28 h.

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