阅读说明：本技术 一种n,n-双(2-丙烯酰胺乙基)丙烯酰胺及其制备方法和应用 (N, N-bis (2-acrylamidoethyl) acrylamide and preparation method and application thereof ) 是由 于文慧 田家龙 陈雨洁 祁珍明 王春霞 马志鹏 贾高鹏 高大伟 张伟 于 2021-10-27 设计创作，主要内容包括：本发明公开了一种N,N-双(2-丙烯酰胺乙基)丙烯酰胺及其制备方法和应用,制备方法包括,向乙腈溶液中加入二乙烯三胺和碳酸钾,搅拌；缓慢滴加甲基丙烯酰氯反应；将反应混合物过滤,滤液浓缩提纯,得到产物N,N-双(2-丙烯酰胺乙基)丙烯酰胺。本发明将织物整理之后性能普遍有所提高,不管是在紫外光交联后还是氯化后都有所提高,在测试毛细效应中,紫外光交联之后的织物效果最显著,氯化后的织物相较原织物也有着一定的提升。(The invention discloses N, N-bis (2-acrylamido ethyl) acrylamide and a preparation method and application thereof, wherein the preparation method comprises the steps of adding diethylenetriamine and potassium carbonate into an acetonitrile solution, and stirring; slowly dripping methacrylic chloride for reaction; and filtering the reaction mixture, concentrating and purifying the filtrate to obtain the product N, N-bis (2-acrylamidoethyl) acrylamide. The invention generally improves the performance of the fabric after finishing, improves the fabric after ultraviolet crosslinking or chlorination, has the most obvious fabric effect after ultraviolet crosslinking in capillary effect test, and improves the chlorinated fabric to a certain extent compared with the original fabric.)

1. A preparation method of N, N-bis (2-acrylamide ethyl) acrylamide is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

adding diethylenetriamine and potassium carbonate into the acetonitrile solution, and stirring;

slowly dripping methacrylic chloride for reaction;

and filtering the reaction mixture, concentrating and purifying the filtrate to obtain the product N, N-bis (2-acrylamidoethyl) acrylamide.

2. The process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to claim 1, wherein: the reaction temperature is 0-60 ℃.

3. The process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to claim 1 or 2, wherein: the molar ratio of the diethylenetriamine to the potassium carbonate is 1: 4.

4. The process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to claim 3 wherein: the addition amount of the acetonitrile solution is 15-30 mL.

5. The process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to claim 3 or 4, wherein: the molar ratio of the methacryloyl chloride to the diethylenetriamine or the potassium carbonate is 1: 4.

6. The process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to claim 3 or 4, wherein: the reaction time is 0.5-1 h.

7. N, N-bis (2-acrylamidoethyl) acrylamide obtained by the production process according to any one of claims 1 to 6, wherein: the structural formula is shown as a formula (I),

8. use of N, N-bis (2-acrylamidoethyl) acrylamide as a finishing agent according to claim 7 wherein: soaking the fabric in N, N-bis (2-acrylamide ethyl) acrylamide, and then soaking and rolling the cotton fabric for three times, wherein the rolling residue rate is 70%;

and (3) crosslinking the fabric by using an ultraviolet crosslinking instrument, cleaning the surface of the fabric by using acetone, and drying to obtain the modified cotton fabric.

9. The use of N, N-bis (2-acrylamidoethyl) acrylamide as a finish according to claim 8 wherein: the concentration of the N, N-bis (2-acrylamidoethyl) acrylamide is 30-90 g/L.

10. Use of N, N-bis (2-acrylamidoethyl) acrylamide as defined in claim 8 or 9 as a finishing agent, wherein: the photo-crosslinking time is 1-6 min.

Technical Field

The invention belongs to the technical field of lightening dyes and printing and dyeing, and particularly relates to N, N-bis (2-acrylamido ethyl) acrylamide and a preparation method and application thereof.

Background

The textile structure mostly contains a porous structure, the loose structure is extremely easy to cause the breeding of microorganisms such as bacteria and the like in the textile structure, and due to the close contact with the human body, the temperature of the human body, the emitted sweat and the like, a proper environment with temperature and humidity is provided for the growth and the breeding of the microorganisms. Particularly, the spread of virus and bacteria is more easily caused in densely populated places, and the breeding and propagation of bacteria can also influence the performance and the use value of the textile, such as the generation of mould which can cause mildew stains on the surface of the textile, not only can cause the color appearance of the textile to be defective, but also can cause the textile to be crisp and influence the performance of the textile. Therefore, in modern society, it is imperative to develop antibacterial textiles and maintain human health in response to such situations.

At present, the antibacterial textile is mainly halamine, the halamine antibacterial agent is a medicament containing an N-X bond, is slightly similar to other organic antibacterial agents, is dissolved in water and has electropositivity, and halogen atoms have high oxidability and are easily combined with microorganisms such as bacteria and the like to destroy the internal structure of the bacteria, so that the antibacterial and bacteriostatic effects are achieved.

Currently, in the textile field, the way of inhibiting bacteria is mainly adopted to treat microorganisms such as bacteria. The antibacterial performance test for the textile mainly aims at candida albicans, escherichia coli and the like. Two general production modes for how to make the antibacterial textile fabric are at home and abroad, which are respectively as follows: before the antibacterial textile fabric is prepared, the antibacterial fiber is firstly prepared and then woven into the antibacterial textile fabric. The other method is to make a common fabric and obtain the finished product of the antibacterial textile fabric by special finishing. The antibacterial textile finished by the antibacterial fiber has more excellent antibacterial effect, more lasting antibacterial effect and better washing resistance, and although the antibacterial textile has obvious effect, the antibacterial textile also has obvious defects, such as difficult manufacture of antibacterial fiber and severe requirements on the used antibacterial agent, so that inorganic antibacterial agents are generally used. The latter production method is convenient to manufacture and has no strict requirement on the type of the antibacterial agent, but the corresponding method has the defects that the antibacterial effect is inferior to that of the former, the lasting performance of the antibacterial effect is inferior to that of the first one, and the washing fastness is correspondingly reduced.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made keeping in mind the above and/or other problems occurring in the prior art.

In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of N, N-bis (2-acrylamide ethyl) acrylamide comprises the steps of adding diethylenetriamine and potassium carbonate into an acetonitrile solution, and stirring;

slowly dripping methacrylic chloride for reaction;

and filtering the reaction mixture, concentrating and purifying the filtrate to obtain the product N, N-bis (2-acrylamidoethyl) acrylamide.

As a preferable embodiment of the process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to the present invention, wherein: the reaction temperature is 0-60 ℃.

As a preferable embodiment of the process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to the present invention, wherein: the molar ratio of the diethylenetriamine to the potassium carbonate is 1: 4.

As a preferable embodiment of the process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to the present invention, wherein: the addition amount of the acetonitrile solution is 15-30 mL.

As a preferable embodiment of the process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to the present invention, wherein: the molar ratio of the methacryloyl chloride to the diethylenetriamine or the potassium carbonate is 1: 4.

As a preferable embodiment of the process for producing N, N-bis (2-acrylamidoethyl) acrylamide according to the present invention, wherein: the reaction time is 0.5-1 h.

Another object of the invention is to provide the N, N-bis (2-acrylamidoethyl) acrylamide obtained by the preparation method, which has a structural formula shown as a formula (I),

the invention also aims to provide the application of the N, N-bis (2-acrylamido ethyl) acrylamide as a finishing agent, wherein the fabric is soaked in the N, N-bis (2-acrylamido ethyl) acrylamide, and then the cotton fabric is soaked and rolled for three times, and the rolling residual rate is 70 percent;

and (3) crosslinking the fabric by using an ultraviolet crosslinking instrument, cleaning the surface of the fabric by using acetone, and drying to obtain the modified cotton fabric.

As a preferred variant of the use of the N, N-bis (2-acrylamidoethyl) acrylamide according to the invention as a finishing agent, wherein: the concentration of the N, N-bis (2-acrylamidoethyl) acrylamide is 30-90 g/L.

As a preferred variant of the use of the N, N-bis (2-acrylamidoethyl) acrylamide according to the invention as a finishing agent, wherein: the photo-crosslinking time is 1-6 min.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, N-bis (2-acrylamido ethyl) acrylamide fabric antibacterial agent is prepared from methacryloyl chloride and diethylenetriamine, added into cotton fabric by fabric finishing, and grafted on the surface of the fabric through ultraviolet crosslinking. The performance of the fabric after finishing is generally improved, for example, the uvioresistant performance is improved after ultraviolet light crosslinking or chlorination, in a capillary effect test, the fabric effect after ultraviolet light crosslinking is most obvious, and the chlorinated fabric is improved to a certain extent compared with the original fabric.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, specific embodiments thereof are described in detail below with reference to examples of the specification.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Fabric active chlorine content test

And measuring the active chlorine content of the modified cotton fabric by using a chlorination and titration mode. The operation process is as follows: the textile finished by the reagent is put into a sodium hypochlorite solution, the sodium hypochlorite solution is formed by mixing 100mL of distilled water and 8g of sodium hypochlorite, and then the pH value is adjusted to be neutral by using a portable pH meter. When the mixing was started, the solution was alkaline and had a pH of 12 to 13, and the pH was lowered with dilute hydrochloric acid to give 7. The fabric was soaked in sodium hypochlorite solution for 1 hour to allow sufficient reaction. After soaking, the surface was rinsed with distilled water and the cloth was placed in an oven at 45 ℃ for 1 hour. During the preparation, potassium iodide solution is prepared, 0.1g of potassium iodide is mixed with 20mL of distilled water, after the fabric is dried, each side of the fabric is cut off, preferably a little, all the sides of the fabric are cut off, 0.1g of rag is cut off, and the solution is put into the potassium iodide solution, so that the solution can present a light yellow color, and the rag is black. Dropping 1 to 2 drops of starch solution (boiling 1g of starch with 99 g of distilled water) to turn the drug blue, sealing the drug solution with a preservative film for half an hour, dropping the drug solution into the solution with sodium thiosulfate solution while stirring the reagent, and observing the solution changing from blue to colorless.

The content of active chlorine contained in the fabric can be obtained by the following calculation formula:

in the formula, V represents the amount of the sodium thiosulfate solution used (L), and W represents the mass of the cotton fabric used (g).

Water washing resistance test for fabric finishing

In order to test the fastness of the textile dyeing process, before the textile chlorination process, the textile is subjected to a multi-group comparison test, 8cm multiplied by 8cm 4 pieces of cloth subjected to textile finishing are taken and washed by acetone, the washing times are set to be 1 time, 5 times, 15 times and 20 times, then the next chlorine content test is started after drying, and the test results are compared.

Test for breaking Strength of Fabric

And (4) testing the breaking strength of the fabric according to the GB/T3923 and 2013 standards, wherein the yarns on two sides of the sample strip are removed by using a sample removing strip method to reduce the width of the sample strip to 5 cm. The fabric was stretched at constant speed using an electronic fabric dynamometer until breakage. Test bars 5 bars were used and tested for strength.

Ultraviolet protection performance test of fabric

According to GB/T18830-2009, the experimental instrument is a YG (B)912E type ultraviolet-proof tester, and the test is mainly to investigate whether the ultraviolet-proof performance of the antibacterial agent finished textile fabric prepared by the experiment changes or not, and whether a certain ultraviolet-proof effect is added on the basis of improving the antibacterial performance of the textile fabric.

Fabric capillary effect test

According to FZ/T01071-2008, the experimental apparatus is a YLCK 800 type apparatus for testing, and the capillary effect is a phenomenon showing the water absorption of the fabric. Three pieces of cloth with the length of 40mm and the width of 25mm are used, one sample strip is hung, the other side of the sample strip is placed on the water surface, and the rising value of the solution along the cloth sample at different time periods is measured.

Example 1

(1) The method comprises the steps of firstly adding acetonitrile (15mL) at 0 ℃ by using a low-temperature constant-temperature stirring reaction bath, then adding diethylenetriamine (0.54mL, 5mmol) and potassium carbonate (2.76g, 20mmol) into an acetonitrile solution, continuously stirring by using a rotor during the process, then slowly dropwise adding methacryloyl chloride (104mL, 17mmol) by using a rubber head dropper, reacting for half an hour, and mainly adopting a manual dropwise adding mode to dropwise add the methacryloyl chloride to prevent insufficient reaction caused by too fast dropwise adding. The reaction mixture was then placed in an oil bath and stirred at room temperature for four hours. The solid was separated by suction filtration equipment, the filter cake was washed with dichloromethane, and the filtrate was concentrated and purified using a rotary evaporator (temperature 60 ℃ C., rotation speed 40rpm) to give a yellow oily liquid product. The yield was 78%.

The structural formula of the compound is as follows:

example 2

This example 2 is substantially the same as example 1 except for the difference in reaction temperature and reaction time, as shown in Table 1.

TABLE 1

Reaction ofTemperature of	Reaction time	Yield (%)
			0℃	4h	78
At room temperature	4h	56
			60℃	4h	48
0℃	2h	55
			0℃	6h	62

As can be seen from the data in Table 1, the yield gradually decreased with increasing reaction temperature under the same reaction time, and the yield reached as high as 78% at 0 ℃.

At a reaction temperature of 0 ℃, the yield increases and then decreases with increasing reaction time, and at a reaction time of 4 hours, the yield is highest.

Example 3

This example 3 is substantially the same as example 1 except for the difference in the amount of potassium carbonate added, as shown in Table 2.

TABLE 2

As can be seen from the data in table 1, under otherwise identical reaction conditions, the yield rapidly increased from 46% to 78% as the addition amount of potassium carbonate increased from 10mmol to 20mmol, since the added potassium carbonate was an acid-binding agent, which neutralized the hydrochloric acid generated in the reaction, resulting in an increase in yield; when the addition amount of potassium carbonate was further increased to 30mmol, the yield was not significantly increased, and in order to reduce the addition amount of the raw material, it is more preferable to select the addition amount of potassium carbonate to be 20 mmol.

Example 3

The method comprises the following steps of finishing cotton fabrics by using the N, N-bis (2-acrylamido ethyl) acrylamide prepared in example 1 as a finishing agent, cutting cotton fabrics of 8cm multiplied by 8cm, soaking the cotton fabrics in N, N-bis (2-acrylamido ethyl) acrylamide with different concentrations for 20min, then soaking the cotton fabrics in a padder for three times, wherein the rolling residual rate is 70%, and soaking for 20min after each rolling; and (3) crosslinking the fabric by using an ultraviolet crosslinking instrument after finishing rolling, cleaning the surface of the fabric by using acetone after finishing forward and reverse crosslinking for 3min, and drying for 50min at 45 ℃ to obtain the modified cotton fabric.

The N, N-bis (2-acrylamidoethyl) acrylamide obtained in the experimental process is yellow oil, the concentration of the N, N-bis (2-acrylamidoethyl) acrylamide is too high, the concentration of the N, N-bis (2-acrylamidoethyl) acrylamide is found to cause the fabric to become yellow and hard, the wearability of the fabric is also reduced, and the ultraviolet crosslinking time is also found to influence the fabric performance in the finishing process.

N, N-bis (2-acrylamidoethyl) acrylamide is diluted by ethanol to different concentrations, the ultraviolet light crosslinking time is kept at 3min, and the influence of different finishing agent concentrations on chlorination and titration results is researched. The test results are shown in table 3.

TABLE 3

Concentration of finishing agent	Crosslinking time of ultraviolet light	Titration amount of sodium thiosulfate	Active chlorine content
				10g/L	3min	7.9mL	0.14％
30g/L	3min	8.1mL	0.143％
				60g/L	3min	12.8mL	0.23％
90g/L	3min	11.6mL	0.21％

As can be seen from the experimental results in Table 3, under otherwise identical reaction conditions, the titration amount of sodium thiosulfate and the active chlorine content decrease first and then as the concentration of N, N-bis (2-acrylamidoethyl) acrylamide increases, and the titration result is the best when the concentration of N, N-bis (2-acrylamidoethyl) acrylamide is 60 g/L.

Example 4

According to the test results of example 3, the following experiment was conducted while uniformly setting the concentration of N, N-bis (2-acrylamidoethyl) acrylamide at 60g/L and the UV crosslinking time at 1min, 2min, 3min, 6min and 12min, respectively. Table 4 below shows the experimental results.

TABLE 4

Crosslinking time of ultraviolet light	Titration amount of sodium thiosulfate	Active chlorine content
			1min	6.7mL	0.12％
2min	7.1mL	0.13％
			3min	12.8mL	0.23％
6min	10.5mL	0.18％
			12min	6.3mL	0.11％

Experiments show that the cross-linking time is less than 3min, and the control group experiment results with the cross-linking time exceeding 3min are not ideal, analysis shows that the short cross-linking time can cause the finishing agent not to be fully combined with the textile, the cross-linking time is too long, the amido bond is easy to break, and the experiment effect is influenced. The graft amount was calculated based on the above experimental conditions, and is shown in Table 5.

TABLE 5

Concentration of finishing agent	Crosslinking time of ultraviolet light	Quality before finishing of fabric	Quality of finished fabric	Graft amount	Graft ratio
						60g/L	3min	0.572g	0.647g	0.075	13.11％
60g/L	3min	0.594g	0.651g	0.057	9.60％
						60g/L	3min	0.632g	0.694g	0.062	9.81％
60g/L	3min	0.665g	0.728g	0.063	9.47％
						60g/L	3min	0.662g	0.740g	0.078	11.78％

The average graft amount was 0.067g and the average graft ratio was 10.75% as shown in Table 5.

In conclusion, the product concentration of the experiment should be set to be 60g/L, and the ultraviolet light crosslinking time should be positive and negative 3 min.

Example 5

The method comprises the following steps of finishing cotton fabrics by using the N, N-bis (2-acrylamido ethyl) acrylamide prepared in example 1 as a finishing agent, cutting a cotton fabric of 8cm multiplied by 8cm, soaking the cotton fabric in N, N-bis (2-acrylamido ethyl) acrylamide with the concentration of 60g/L for 20min, then soaking and rolling the cotton fabric by using a padder for three times, wherein the rolling residual rate is 70%, and soaking for 20min after finishing rolling each time; and (3) crosslinking the fabric by using an ultraviolet crosslinking instrument after finishing rolling, cleaning the surface of the fabric by using acetone after finishing forward and reverse crosslinking for 3min, and drying for 50min at 45 ℃ to obtain the modified cotton fabric.

And making multiple groups of comparison tests on the modified cotton fabric according to different washing times, washing the modified cotton fabric with acetone after ultraviolet crosslinking, setting the washing times to be 1 time, 5 times, 10 times, 20 times and 40 times, and then drying to start the next chlorine content test to compare test results. The experimental results are shown in table 6 below.

TABLE 6

Number of washes	Chlorine content Cl+(％)
		1	0.29±0.01
5	0.25±0.01
		10	0.20±0.01
20	0.13±0.01
		45	0.02±0.01
Re-chlorination	0.23±0.01

According to the table, the chlorine content of the fabric is negatively influenced after multiple times of water washing, the chlorine content of five times of water washing is not much reduced than that of one time of water washing, the chlorine content is reduced by only 0.03% from 0.29% to 0.25%, and the loss rate is 10.34%. However, after 20 times of washing, the loss rate is remarkably reduced, namely, the loss rate is reduced by 0.27 percent from 0.29 percent to 0.02 percent and is 93.1 percent. However, due to the special properties of the halamine antibacterial agent, chloride ions can be removed in the solution, but the chlorine content of the halamine antibacterial agent can be recovered to a certain extent when the halamine antibacterial agent is chloridized again, and although the halamine antibacterial agent cannot be completely recovered, the antibacterial performance of the halamine antibacterial agent is not greatly influenced.

Example 6

After the cotton fabric is chemically treated, its properties are more or less affected, and this variable of its breaking strength is tested by an electronic fabric strength meter. All tests are divided into three types, wherein the first type tests the performance of the original fabric, the second type tests the performance of the fabric after ultraviolet light crosslinking, and the third type tests the performance of the fabric after chlorination.

Tests have found that the tensile strength at break of the finished fabric is somewhat reduced. Such as ultraviolet light crosslinking, the tensile strength at break decreases in either the warp or weft direction. The strength after chlorination is reduced by less than 10N compared to that after UV crosslinking. It follows that the fabric finish has a negative effect on the tensile strength at break of cotton fabrics.

The effect of the finish N, N-bis (2-acrylamidoethyl) acrylamide prepared in example 1 on the tensile strength at break of cotton fabric at different concentrations of finish and different uv crosslinking times was investigated and the results are shown in table 7.

TABLE 7

As can be seen from the data in Table 7, the crosslinking time is short, the influence on the tensile strength at break of the fabric is small, and the tensile strength at break in the warp direction of the fabric is slightly reduced when the crosslinking time is prolonged. The concentration of the finishing agent is low, the tensile strength of the fabric at warp break is reduced slightly, and when the concentration of the finishing agent is increased, the tensile strength of the fabric at warp break is reduced slightly.

Example 7

The method comprises the following steps of finishing cotton fabrics by using the N, N-bis (2-acrylamido ethyl) acrylamide prepared in example 1 as a finishing agent, cutting a cotton fabric of 8cm multiplied by 8cm, soaking the cotton fabric in N, N-bis (2-acrylamido ethyl) acrylamide with the concentration of 60g/L for 20min, then soaking and rolling the cotton fabric by using a padder for three times, wherein the rolling residual rate is 70%, and soaking for 20min after finishing rolling each time; and (3) crosslinking the fabric by using an ultraviolet crosslinking instrument after finishing rolling, cleaning the surface of the fabric by using acetone for 1 time after finishing forward and reverse crosslinking for 3min, and drying for 50min at 45 ℃ to obtain the modified cotton fabric.

And carrying out ultraviolet protection test, fabric crease recovery angle test and capillary effect test on the obtained modified cotton fabric. See tables 8, 9, 10.

TABLE 8 ultraviolet protection Performance test

Sample (I)	Mean UVA transmission	Mean value of UVB transmission	Ultraviolet ray protection factor (UPF)
				Original cloth	6.05	6.75	16.29
After ultraviolet crosslinking of the fabric	8.94	3.96	21.84
				After chlorination of fabrics	7.84	3.07	27.31

TABLE 9 Fabric crease recovery Angle determination

Sample (I)	Crease recovery angle
		Original cloth	130°
After ultraviolet crosslinking of the fabric	101°
		After chlorination of fabrics	80°

TABLE 10 determination of capillary Effect

Tests show that the performance of the fabric after finishing is generally improved, such as the ultraviolet resistance, the ultraviolet protection performance of the fabric after ultraviolet crosslinking is improved by 5.55 compared with that of the original fabric, the performance is improved by 34.07%, the performance is improved by 11.02 after chlorination, and the performance is improved by 67.65%. In the capillary effect test, after the fabric is crosslinked by ultraviolet light, the climbing speed of the solution is obviously improved, and the chlorinated fabric has good wicking height.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.