CN115304980B

CN115304980B - Surface treatment process for processing automobile anti-collision strip

Info

Publication number: CN115304980B
Application number: CN202211062871.7A
Authority: CN
Inventors: 孟瑞章; 张涛; 蒋阳; 赖红杰
Original assignee: Ruiyue Automobile Industry Chongqing Co ltd
Current assignee: Ruiyue Automobile Industry Chongqing Co ltd
Priority date: 2022-09-01
Filing date: 2022-09-01
Publication date: 2023-04-25
Anticipated expiration: 2042-09-01
Also published as: CN115304980A

Abstract

The invention relates to a surface treatment process for processing an automobile anti-collision strip, which belongs to the technical field of anti-collision strip processing and comprises the following steps: the method comprises the following steps of firstly, stirring and mixing resin emulsion, a thickening agent, a wetting agent, a defoaming agent, modified nano silicon dioxide and water to obtain a surface treating agent; and secondly, coating a surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 1-2h at the temperature of 60 ℃. In order to solve the problems that the surface of the anti-collision strip becomes sticky, bacteria and dust are easy to adsorb, the self-cleaning property is poor, the appearance of the anti-collision strip is influenced, and the use function is influenced, the surface treating agent is coated on the surface of the pre-treated anti-collision strip to form a protective layer, and the use performance of the anti-collision strip is improved. The surface treating agent has the main effects of protecting resin emulsion and modified nano silicon dioxide, preventing the stickiness caused by the transformation of the plasticizer, preventing dust pollution, improving the wear resistance of the anti-collision strip and improving the outdoor weather resistance.

Description

Surface treatment process for processing automobile anti-collision strip

Technical Field

The invention belongs to the technical field of anti-collision strip processing, and particularly relates to a surface treatment process for processing an automobile anti-collision strip.

Background

Anti-collision strips, also called guard strips, rubbing strips, fender adhesive strips, ribbings, straps and the like. The automobile anti-collision strip is made of rubber plastic (modified PVC) materials, belongs to automobile body exterior trim, and mainly prevents small scratches from damaging parts, and is generally installed at corners of automobile doors and front and rear bumpers. The automobile anti-collision strip has the functions of increasing the lines and the dynamic sense of the automobile body and playing a role in decoration; the side surface of the car body is prevented from being scratched or bumped by foreign objects, and the protection function is achieved.

The in-process that the crashproof strip was made uses a large amount of plasticizers, through high temperature treatment, the migration appears to separate out to the plasticizer, and crashproof strip surface becomes sticky, adsorbs bacterium and dust easily, and self-cleaning nature is poor, influences crashproof strip's outward appearance, influences the function of use.

Disclosure of Invention

In order to solve the technical problems in the background art, the invention provides a surface treatment process for processing an automobile anti-collision strip.

The aim of the invention can be achieved by the following technical scheme:

a surface treatment process for processing an automobile anti-collision strip comprises the following steps:

the method comprises the steps of firstly, stirring and mixing a mixed monomer, a functional monomer and ammonium persulfate to obtain a component A; stirring and mixing the mixed monomer, acrylic acid and ammonium persulfate to obtain a component B; mixing and stirring component A and water under the protection of nitrogen at the temperature of 82 ℃ for reaction for 1h, then adding component B, heating to 90 ℃ after the addition is finished, continuously stirring for 2h, then cooling to 45 ℃, adjusting the pH value to 8, then adding adipic dihydrazide, continuously stirring for 20min, adding water to adjust the solid content to 45-48%, and sieving with a 200-mesh sieve to obtain resin emulsion; stirring and mixing the resin emulsion, the thickener, the wetting agent, the defoamer, the modified nano silicon dioxide and water to obtain a surface treating agent;

and secondly, coating a surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 1-2 hours at the temperature of 60 ℃.

Further, according to parts by weight, 30-33 parts of resin emulsion, 0.1-0.2 part of thickener, 0.3-0.5 part of wetting agent, 0.1-0.3 part of defoamer, 8-10 parts of modified nano silicon dioxide and 10-13 parts of water.

Further, the mixed monomers are methyl methacrylate, butyl acrylate and acetoacetoxyethyl methacrylate according to the mass ratio of 30:5:40, mixing; the mass ratio of the mixed monomer to the functional monomer to the ammonium persulfate in the component A is 30:6:0.03; the mass ratio of the mixed monomer to the acrylic acid to the ammonium persulfate in the component B is 30:0.5:0.03.

further, the mass ratio of the component A to the component B to the adipic dihydrazide is 10-12:40:0.6.

further, the functional monomer is prepared by the following steps:

under the protection of nitrogen, mixing H-POSS with toluene, adding allyl methacrylate and dodecafluoroheptyl methacrylate, stirring and dispersing, adding chloroplatinic acid, stirring and dispersing for 50-60min at the temperature of 20 ℃, heating to 80 ℃, continuing to react for 12H, and removing toluene after the reaction is finished to obtain the functional monomer.

Further, the dosage ratio of H-POSS, allyl methacrylate, dodecafluoroheptyl methacrylate, chloroplatinic acid and toluene is 5-6g:3g:1g:0.1g:50mL.

Further, the pre-treated bumper strip is prepared by the steps of:

sodium chloride, sodium hydroxide and deionized water are mixed according to the dosage ratio of 3g:15g:100mL of the mixture is added into the anti-collision bar, soaked for 30-40min at 50 ℃, taken out, washed by water and dried, and the pretreated anti-collision bar is obtained. The surface of the anti-collision strip is treated by sodium chloride and sodium hydroxide, so that the roughness of the surface of the anti-collision strip is improved, the anti-collision strip can be better contacted with a surface treating agent, and the contact area and the adsorption effect are increased.

Further, the modified nano-silica is prepared by the steps of:

step one, adding 2, 4-dihydroxybenzophenone and triethylamine into tetrahydrofuran under the condition of ice water bath, then dropwise adding acryloyl chloride, controlling the temperature not to exceed 5 ℃ in the dropwise adding process, keeping the temperature unchanged after the addition, continuously stirring for reaction for 6 hours, extracting with water and dichloromethane after the reaction is finished, and concentrating an organic phase under reduced pressure to obtain an ultraviolet absorption component;

adding an ultraviolet absorption component into toluene under the protection of nitrogen, heating to 50 ℃, adding a Karster catalyst, stirring for 30min, adding triethoxysilane, heating to 70 ℃, reacting for 24h, and removing toluene after the reaction is finished to obtain a modifier;

and thirdly, adding the modifier and the nano silicon dioxide into an ethanol water solution with the volume fraction of 90%, stirring and dispersing for 2 hours at the temperature of 40 ℃, centrifuging after the dispersion is finished, and drying in vacuum to obtain the modified nano silicon dioxide. The modified nanosilica can be better dispersed in the resin matrix than untreated nanosilica; active groups are introduced into the structure of the ultraviolet light absorber 2, 4-dihydroxybenzophenone, the ultraviolet light absorbing component and triethoxysilane are utilized to generate hydrosilylation to prepare the modifier, then nano silicon dioxide is utilized as a carrier of the ultraviolet light absorber to load the ultraviolet light absorbing component, so that the migration resistance of the ultraviolet light absorber is improved, and the ultraviolet light resistance of the ultraviolet light absorber is better exerted.

Further, the use amount ratio of 2, 4-dihydroxybenzophenone, acryloyl chloride, triethylamine and tetrahydrofuran was 0.01mol:0.012mol:0.01mol:20mL; the ratio of the amounts of UV absorbing component, triethoxysilane, kadster catalyst and toluene was 2.3g:1.5g:0.2mL:30mL; the dosage ratio of the modifier, the nano silicon dioxide and the ethanol water solution is 0.2g:0.8g:20mL.

Further, the wetting agent is Tego-270, and the defoaming agent is Tego Foamex280; the thickener is RM-8W.

The invention has the beneficial effects that:

in order to solve the problems that the surface of the anti-collision strip becomes sticky, bacteria and dust are easy to adsorb, the self-cleaning property is poor, the appearance of the anti-collision strip is influenced, and the use function is influenced, the surface treating agent is coated on the surface of the pre-treated anti-collision strip to form a protective layer, and the use performance of the anti-collision strip is improved. The anti-collision strip has the advantages of preventing the stickiness caused by the transformation of the plasticizer, preventing dust pollution, improving the wear resistance of the anti-collision strip and improving the outdoor weather resistance.

The surface treating agent has the main effects of protecting resin emulsion and modified nano silicon dioxide, wherein the resin emulsion is added with functional monomers, the raw materials of the functional monomers comprise allyl methacrylate, H-POSS and dodecafluoroheptyl methacrylate, the H-POSS is used as a carrier through molecular design, the allyl methacrylate and the dodecafluoroheptyl methacrylate are combined, and then the functional monomers and the mixed monomers are subjected to polymerization reaction, so that the surface treating agent has good and controllable miscibility, can participate in and strengthen the establishment of a system cross-linking network, not only can heat-resistant Si-O bonds be introduced, but also C-F long chains are introduced, the hydrophobicity of the surface treating agent is improved, the POSS inorganic cage skeleton structure can limit chain segment movement to improve heat resistance, and the characteristics of good inorganic thermal stability and the like are effectively combined.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Preparing modified nano silicon dioxide:

step one, adding 2, 4-dihydroxybenzophenone and triethylamine into tetrahydrofuran under the condition of ice water bath, then dropwise adding acryloyl chloride, controlling the temperature not to exceed 5 ℃ in the dropwise adding process, keeping the temperature unchanged after the addition, continuously stirring for reaction for 6 hours, extracting with water and dichloromethane after the reaction is finished, and concentrating an organic phase under reduced pressure to obtain an ultraviolet absorption component; the dosage ratio of 2, 4-dihydroxybenzophenone, acryloyl chloride, triethylamine and tetrahydrofuran is 0.01mol:0.012mol:0.01mol:20mL;

adding an ultraviolet absorption component into toluene under the protection of nitrogen, heating to 50 ℃, adding a Karster catalyst, stirring for 30min, adding triethoxysilane, heating to 70 ℃, reacting for 24h, and removing toluene after the reaction is finished to obtain a modifier; the ratio of the amounts of UV absorbing component, triethoxysilane, kadster catalyst and toluene was 2.3g:1.5g:0.2mL:30mL;

and thirdly, adding the modifier and the nano silicon dioxide into an ethanol water solution with the volume fraction of 90%, stirring and dispersing for 2 hours at the temperature of 40 ℃, centrifuging after the dispersion is finished, and drying in vacuum to obtain the modified nano silicon dioxide. The dosage ratio of the modifier, the nano silicon dioxide and the ethanol water solution is 0.2g:0.8g:20mL.

Example 2

Preparing a resin emulsion:

6g of water, 11.5g of tetramethyl ammonium hydroxide pentahydrate, 40mL of methanol and 13g of tetraethoxysilane are mixed and stirred for 24 hours at 20 ℃, then the obtained reaction solution is poured into a mixed solution of 24g of chlorodimethyl chlorosilane and 40mL of normal hexane, the temperature is maintained at 10 ℃, the reaction is continued for 12 hours, after the reaction is finished, the upper layer liquid is separated by a separating funnel, and the mixture is concentrated by rotary evaporation, so that H-POSS is obtained.

Under the protection of nitrogen, mixing H-POSS with toluene, adding allyl methacrylate and dodecafluoroheptyl methacrylate, stirring and dispersing, adding chloroplatinic acid, stirring and dispersing for 50min at the temperature of 20 ℃, heating to 80 ℃, continuing to react for 12H, and removing toluene after the reaction is finished to obtain the functional monomer. The dosage ratio of H-POSS, allyl methacrylate, dodecafluoroheptyl methacrylate, chloroplatinic acid and toluene was controlled to be 5g:3g:1g:0.1g:50mL.

Stirring and mixing the mixed monomer, the functional monomer and ammonium persulfate to obtain a component A; stirring and mixing the mixed monomer, acrylic acid and ammonium persulfate to obtain a component B; wherein the mixed monomers are methyl methacrylate, butyl acrylate and acetoacetoxyethyl methacrylate according to the mass ratio of 30:5:40, mixing; the mass ratio of the mixed monomer to the functional monomer to the ammonium persulfate in the component A is 30:6:0.03; the mass ratio of the mixed monomer to the acrylic acid to the ammonium persulfate in the component B is 30:0.5:0.03.

mixing and stirring component A and water under the protection of nitrogen at the temperature of 82 ℃ for reaction for 1h, then adding component B, heating to 90 ℃ after the addition is finished, continuously stirring for 2h, then cooling to 45 ℃, adjusting the pH value to 8, then adding adipic dihydrazide, continuously stirring for 20min, adding water to adjust the solid content to 45%, and sieving by a 200-mesh sieve to obtain resin emulsion; the dosage mass ratio of the component A to the component B to the adipic dihydrazide is controlled to be 10:40:0.6.

example 3

Preparing a resin emulsion:

Under the protection of nitrogen, mixing H-POSS with toluene, adding allyl methacrylate and dodecafluoroheptyl methacrylate, stirring and dispersing, adding chloroplatinic acid, stirring and dispersing for 60min at the temperature of 20 ℃, heating to 80 ℃, continuing to react for 12H, and removing toluene after the reaction is finished to obtain the functional monomer. The dosage ratio of H-POSS, allyl methacrylate, dodecafluoroheptyl methacrylate, chloroplatinic acid and toluene was controlled to be 6g:3g:1g:0.1g:50mL.

mixing and stirring component A and water under the protection of nitrogen at the temperature of 82 ℃ for reaction for 1h, then adding component B, heating to 90 ℃ after the addition is finished, continuously stirring for 2h, then cooling to 45 ℃, adjusting the pH value to 8, then adding adipic dihydrazide, continuously stirring for 20min, adding water to adjust the solid content to 48%, and sieving by a 200-mesh sieve to obtain resin emulsion; the dosage mass ratio of the component A, the component B and the adipic dihydrazide is controlled to be 12:40:0.6.

comparative example 1

The functional monomer in example 3 was changed to dodecafluoroheptyl methacrylate, and the remaining raw materials and the preparation process were kept unchanged, to obtain a resin emulsion a.

Example 4

firstly, stirring and mixing 30 parts of the resin emulsion prepared in the example 2, 0.1 part of a thickener RM-8W, 0.3 part of a wetting agent Tego-270, 0.1 part of a defoaming agent Tego Foamex280, 8 parts of modified nano silicon dioxide prepared in the example 1 and 10 parts of water according to parts by weight to obtain a surface treating agent;

secondly, mixing sodium chloride, sodium hydroxide and deionized water according to the dosage ratio of 3g:15g: mixing 100mL, adding the anti-collision strip, soaking for 30min at 50 ℃, taking out, washing with water, and drying to obtain the pretreated anti-collision strip; and (3) coating the surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 1h at the temperature of 60 ℃.

Example 5

the method comprises the steps of firstly, stirring and mixing 32 parts by weight of the resin emulsion prepared in the example 3, 0.1 part by weight of thickener RM-8W, 0.4 part by weight of wetting agent Tego-270, 0.2 part by weight of defoamer Tego Foamex280, 9 parts by weight of modified nano-silica prepared in the example 1 and 12 parts by weight of water to obtain a surface treating agent;

secondly, mixing sodium chloride, sodium hydroxide and deionized water according to the dosage ratio of 3g:15g: mixing 100mL, adding the anti-collision strip, soaking for 35min at 50 ℃, taking out, washing with water, and drying to obtain the pretreated anti-collision strip; and (3) coating the surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 2 hours at the temperature of 60 ℃.

Example 6

firstly, 33 parts of the resin emulsion prepared in the example 3, 0.2 part of thickener RM-8W, 0.5 part of wetting agent Tego-270, 0.3 part of defoamer Tego Foamex280, 10 parts of modified nano silicon dioxide prepared in the example 1 and 13 parts of water are stirred and mixed to obtain a surface treating agent;

secondly, mixing sodium chloride, sodium hydroxide and deionized water according to the dosage ratio of 3g:15g: mixing 100mL, adding the anti-collision strip, soaking for 40min at 50 ℃, taking out, washing with water, and drying to obtain the pretreated anti-collision strip; and (3) coating the surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 2 hours at the temperature of 60 ℃.

Comparative example 2

The resin emulsion A prepared in comparative example 1 was replaced with the resin emulsion of example 5, and the remaining raw materials and the preparation process were kept the same as those of example 5.

Comparative example 3

The modified nano-silica in example 5 was replaced with unmodified nano-silica, and the rest of the raw materials and the preparation process were the same as those in example 5.

The surface treatments prepared in examples 4 to 6 and comparative examples 2 to 3 were tested;

test water contact angle and impact resistance were tested according to GB/T1732-1993; yellowing resistance according to ISO 11507:1997, resistance to yellowing, ΔE (UVA 168 hours).

The test results are shown in table 1 below:

TABLE 1

Testing	Example 4	Example 5	Example 6	Comparative example 2	Comparative example 3
						Water contact angle- ^o	116.5	117.4	117.1	115.2	110.4
Impact strength/kg cm	82	86	85	74	52
						△E	0.3	0.3	0.3	0.4	0.9

From test data, the surface treating agent prepared by the invention has good hydrophobicity and impact resistance, can form protection for automobile anti-collision strips, and has good light aging resistance.

Friction resistance test: the friction distance is set to 35mm, the friction probe load is 200g, the friction times are respectively set to 400, 600 and 1000 times, and static contact angle measurement is carried out on the rubbed coating. The samples prepared in example 5 and comparative examples 2-3 were tested;

the results are shown in Table 2 below:

TABLE 2

	400 times	600 times	1000 times
				Example 5	106.8	101.5	92.9
Comparative example 2	100.2	95.8	87.4
				Comparative example 3	102.4	98.7	90.3

From the test data, it is found that the abrasion resistance test was performed on the surface treatment agent after film formation, and that the sample prepared in example 5 was better in performance, and that in addition, the performance of comparative example 3 was better than that of comparative example 2, probably because the resin emulsion in comparative example 3 was the same as that in example, si-O-Si segments were formed in the resin, the crosslinking density was increased, and the abrasion resistance was better.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely illustrative and explanatory of the invention, as various modifications and additions may be made to the particular embodiments described, or in a similar manner, by those skilled in the art, without departing from the scope of the invention or exceeding the scope of the invention as defined in the claims.

Claims

1. The surface treatment process for processing the automobile anti-collision strip is characterized by comprising the following steps of:

the method comprises the steps of firstly, stirring and mixing a mixed monomer, a functional monomer and ammonium persulfate to obtain a component A; stirring and mixing the mixed monomer, acrylic acid and ammonium persulfate to obtain a component B; mixing and stirring component A and water under the protection of nitrogen at the temperature of 82 ℃ for reaction for 1h, then adding component B, heating to 90 ℃ after the addition is finished, continuously stirring for 2h, then cooling to 45 ℃, adjusting the pH value to 8, then adding adipic dihydrazide, continuously stirring for 20min, adding water to adjust the solid content to 45-48%, and sieving with a 200-mesh sieve to obtain resin emulsion; according to parts by weight, stirring and mixing 30-33 parts of resin emulsion, 0.1-0.2 part of thickener, 0.3-0.5 part of wetting agent, 0.1-0.3 part of defoamer, 8-10 parts of modified nano silicon dioxide and 10-13 parts of water to obtain a surface treating agent;

secondly, coating a surface treating agent on the surface of the pretreated anti-collision strip, and then curing for 1-2h at the temperature of 60 ℃;

the mixed monomer is methyl methacrylate, butyl acrylate and acetoacetoxyethyl methacrylate according to the mass ratio of 30:5:40, mixing; the mass ratio of the mixed monomer to the functional monomer to the ammonium persulfate in the component A is 30:6:0.03; the mass ratio of the mixed monomer to the acrylic acid to the ammonium persulfate in the component B is 30:0.5:0.03;

the mass ratio of the component A to the component B to the adipic dihydrazide is 10-12:40:0.6;

the functional monomer is prepared through the following steps:

mixing H-POSS with toluene under the protection of nitrogen, adding allyl methacrylate and dodecafluoroheptyl methacrylate, stirring and dispersing, adding chloroplatinic acid, stirring and dispersing for 50-60min at 20 ℃, heating to 80 ℃, and continuing to react for 12H to obtain a functional monomer; the dosage ratio of H-POSS, allyl methacrylate, dodecafluoroheptyl methacrylate, chloroplatinic acid and toluene is 5-6g:3g:1g:0.1g:50mL;

the modified nano silicon dioxide is prepared through the following steps:

step one, adding 2, 4-dihydroxybenzophenone and triethylamine into tetrahydrofuran under the ice water bath condition, then dropwise adding acryloyl chloride, controlling the temperature not to exceed 5 ℃ in the dropwise adding process, keeping the temperature unchanged after the adding, and continuously stirring and reacting for 6 hours to obtain an ultraviolet absorption component;

adding an ultraviolet absorption component into toluene under the protection of nitrogen, heating to 50 ℃, adding a Karster catalyst, stirring for 30min, adding triethoxysilane, heating to 70 ℃, and reacting for 24h to obtain a modifier;

and thirdly, adding the modifier and the nano silicon dioxide into an ethanol water solution with the volume fraction of 90%, and stirring and dispersing for 2 hours at the temperature of 40 ℃ to obtain the modified nano silicon dioxide.

2. The surface treatment process for machining an automobile bumper strip according to claim 1, wherein the pre-treated bumper strip is prepared by the steps of:

sodium chloride, sodium hydroxide and deionized water are mixed according to the dosage ratio of 3g:15g:100mL of the mixture is added into the anti-collision bar, soaked for 30-40min at 50 ℃, taken out, washed and dried to obtain the pretreated anti-collision bar.