Single-component acrylate pressure-sensitive adhesive and preparation method thereof

Abstract

The invention relates to the technical field of pressure-sensitive adhesives, in particular to a single-component acrylate pressure-sensitive adhesive and a preparation method thereof.The single-component acrylate pressure-sensitive adhesive is prepared from, by mass, 138-161 parts of monomers, 190-210 parts of a first solvent, 10-50 parts of a second solvent, 0.1-0.5 part of an initiator and 6-9 parts of a curing agent; the monomer comprises at least one of a soft monomer, a hard monomer and a functional monomer. The specific soft monomer and the curing agent are introduced, and the mass ratio of the soft monomer to the hard monomer to the functional monomer in the monomers is controlled to be (100-110): (30-40): (8-11), so that the oil resistance of the pressure-sensitive adhesive is greatly improved while the high-temperature resistance of the acrylate pressure-sensitive adhesive is improved, and meanwhile, the pressure-sensitive adhesive has good storage stability at room temperature, and is suitable for industrial production. And the application requirements of special occasions such as high temperature and high oil can be met, and important practical value and wide market prospect are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesives, and in particular to a one-component acrylate pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] Generally, the heat resistance of acrylic pressure-sensitive adhesives in high temperature environments is not ideal, because its molecular chains are easy to slide under high temperature conditions, resulting in weakened cohesion and adhesion of the adhesive. Although acrylic pressure-sensitive adhesives have a certain degree of oil resistance due to the ester group, under certain extreme conditions, such as bundling of wiring harnesses inside automobile engines and fixing of components such as oil pipes in fuel systems, the adhesive layer is easily corroded due to the effect of lubricants in the environment, thereby reducing its bonding effect.

[0003] Chinese patent CN118772809A discloses a high-temperature resistant and high-viscosity pressure-sensitive adhesive and its preparation method. By optimizing the formula and preparation process, the high-temperature resistance and viscosity of the pressure-sensitive adhesive are improved, and its mechanical properties are significantly improved. However, the pressure-sensitive adhesive prepared by this process is easily affected by the lubricating oil in the environment and reduces the bonding performance in some special high-temperature and high-oil occasions, such as the bundling of wiring harnesses in automobile engines and the fixing of oil pipes and other parts in automobile fuel systems. Therefore, it is necessary to further improve the high-temperature resistance and oil resistance of acrylic pressure-sensitive adhesives to meet the application requirements of special occasions. Summary of the invention

[0004] In order to solve the problems in the prior art, the first aspect of the present invention provides a one-component acrylic pressure-sensitive adhesive. The raw materials for its preparation include, by weight: 138-161 parts of a monomer, 190-210 parts of a first solvent, 10-50 parts of a second solvent, 0.1-0.5 parts of an initiator, and 6-9 parts of a curing agent; the monomer includes at least one of a soft monomer, a hard monomer, and a functional monomer.

[0005] In one embodiment, the monomers include soft monomers, hard monomers, and functional monomers.

[0006] In one embodiment, the mass ratio of the soft monomer, the hard monomer and the functional monomer is (100-110):(30-40):(8-11), which can be 105:35:11, 100:30:8, 110:40:11.

[0007] In one embodiment, the soft monomer includes at least one of methoxyethyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, butyl acrylate, and isooctyl acrylate; the hard monomer includes at least one of methyl acrylate, methyl methacrylate, and vinyl acetate; and the functional monomer includes at least one of acrylic acid, β-carboxyethyl acrylate, and methpropylene.

[0008] In a preferred embodiment, the soft monomer is methoxyethyl acrylate; the hard monomer is methyl acrylate; and the functional monomer is acrylic acid.

[0009] In a preferred embodiment, the methoxyethyl acrylate is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the methyl acrylate is purchased from BASF-YPC; the acrylic acid is purchased from BASF-YPC; the acrylic acid is purchased from BASF-YPC.

[0010] In one embodiment, the first solvent and the second solvent are both selected from at least one of ethyl acetate and xylene.

[0011] In one embodiment, the first solvent is ethyl acetate.

[0012] In one embodiment, the second solvent is xylene.

[0013] In one embodiment, the curing agent is an amide curing agent.

[0014] In a preferred embodiment, the amide curing agent includes N-methoxyacrylamide.

[0015] In one embodiment, the initiator comprises benzoyl peroxide.

[0016] The second aspect of the present invention provides a method for preparing a one-component acrylic pressure-sensitive adhesive, comprising at least the following steps:

[0017] S1, 50-60wt% of the first solvent and all of the second solvent are mixed to form a mixed solvent 1, and the mixed solvent 1 is mixed with an initiator to form a mixed solvent 2; 9-11wt% of the first solvent and all of the curing agent are mixed to form a mixed solvent 3;

[0018] S2, add all the monomers and the remaining first solvent into a four-necked flask, turn on water bath heating, condensation and stirring, add 3 / 4 volume of mixed solvent 2 after reflux in the flask, and keep warm;

[0019] S3, adding the remaining mixed solvent 2 and keeping warm;

[0020] S4, add the mixed solvent 3 and stir evenly to obtain.

[0021] In one embodiment, in step S2, 3 / 4 of the mass of the mixed solvent 2 is added dropwise, and the time of the addition is 2-3 hours, which can be 2 hours, 2.5 hours, or 3 hours.

[0022] In a preferred embodiment, the addition method of 3 / 4 of the mass of the mixed solvent 2 in step S2 is dropwise addition, and the dropwise addition time is 2.5 hours.

[0023] In one embodiment, the remaining mixed solvent 2 in step S3 is added dropwise, and the time of the addition is 0.5-1.5 h, which can be 0.5 h, 1 h, or 1.5 h.

[0024] In a preferred embodiment, the remaining mixed solvent 2 in step S3 is added dropwise for 1 h.

[0025] In one embodiment, the insulation time in step S2 is 0.5-1.5 h, which can be 0.5 h, 1 h, or 1.5 h; the insulation time in step S3 is 1.5-2.5 h, which can be 1.5 h, 2 h, or 2.5 h.

[0026] In a preferred embodiment, the insulation time in step S2 is 1 hour; and the insulation time in step S3 is 2 hours.

[0027] In one embodiment, the temperature of the water bath heating in step S2 is 80°C.

[0028] In one embodiment, the stirring rate in step S2 is 160 r / min.

[0029] In one embodiment, the temperature of the insulation in step S3 is 80°C

[0030] In one embodiment, the mass ratio of ethyl acetate to xylene in the mixed solvent 1 is 2:1-4:1, which can be 2:1, 3:1, or 4:1.

[0031] Beneficial Effects

[0032] 1. In the present invention, a specific type of soft monomer is selected, and the mass ratio of the soft monomer, the hard monomer and the functional monomer in the monomer is controlled to be (100-110): (30-40): (8-11), thereby greatly improving the high temperature resistance of the acrylic pressure-sensitive adhesive and the oil resistance of the pressure-sensitive adhesive.

[0033] 2. Based on the system of the present invention, by controlling the amount of ethyl acetate and xylene in the mixed solvent, the coating viscosity of the adhesive solution is adjusted and the adhesive properties of the tape are balanced while maintaining the high temperature resistance and oil resistance of the acrylic pressure-sensitive adhesive.

[0034] 3. Based on the system of the present invention, a specific amide curing agent is selected, which not only maintains the high temperature resistance and oil resistance of the acrylic pressure-sensitive adhesive, but also has more excellent peel strength and good storage stability at room temperature.

[0035] 4. The preparation method of the one-component acrylic pressure-sensitive adhesive provided by the present invention has a simple preparation process and can reduce production costs.

[0036] 5. The one-component acrylic pressure-sensitive adhesive prepared by the present invention has a swelling degree of 6% after being immersed in lubricating oil for 24 hours, and a residual adhesive rate of about 1% of the tape after being treated at 150°C for 2 hours, showing excellent oil and high temperature resistance, and has a low viscosity (2563mPa·s) and a long application period, which can meet the application requirements of special occasions such as high temperature and high oil, and has important practical value and broad market prospects. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods in the examples without specifying specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without specifying the manufacturer are all conventional products that can be purchased commercially.

[0038] Example 1

[0039] The first aspect of this embodiment provides a one-component acrylic pressure-sensitive adhesive, and its preparation raw materials include, by weight: 151 parts of monomers, 210 parts of a first solvent, 30 parts of a second solvent, 0.35 parts of an initiator, and 8 parts of a curing agent; the monomers include soft monomers, hard monomers, and functional monomers.

[0040] The soft monomer is methoxyethyl acrylate, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the hard monomer is methyl acrylate purchased from BASF-YPC; and the functional monomer is acrylic acid purchased from BASF-YPC.

[0041] The mass ratio of the soft monomer, the hard monomer and the functional monomer is 105:35:11.

[0042] The first solvent is ethyl acetate. The second solvent is xylene.

[0043] The initiator is benzoyl peroxide. The curing agent is N-methoxyacrylamide.

[0044] A second aspect of the present embodiment provides a method for preparing a one-component acrylic pressure-sensitive adhesive, comprising at least the following steps:

[0045] S1, 120 parts of the first solvent and all of the second solvent are mixed to form a mixed solvent 1, and the mixed solvent 1 is mixed with an initiator to form a mixed solvent 2; 20 parts of the first solvent and all of the curing agent are mixed to form a mixed solvent 3;

[0046] S2, add all the monomers and the remaining first solvent into a four-necked flask, turn on the water bath to heat to 80°C, condense and stir, the stirring rate is 160r / min, after reflux in the flask, add 3 / 4 volume of mixed solvent 2 dropwise, the addition time is 2.5h, and keep warm for 1h;

[0047] S3, adding the remaining mixed solvent 2 dropwise for 1 hour, and keeping warm at 80°C for 2 hours;

[0048] S4, add the mixed solvent 3 and stir evenly to obtain.

[0049] Example 2

[0050] The first aspect of this embodiment provides a one-component acrylic pressure-sensitive adhesive, and its preparation raw materials include, by weight: 151 parts of monomers, 190 parts of a first solvent, 50 parts of a second solvent, 0.35 parts of an initiator, and 8 parts of a curing agent; the monomers include soft monomers, hard monomers, and functional monomers.

[0051] The soft monomer is methoxyethyl acrylate; the hard monomer is methyl acrylate; and the functional monomer is acrylic acid.

[0052] The mass ratio of the soft monomer, the hard monomer and the functional monomer is 105:35:11.

[0053] The first solvent is ethyl acetate. The second solvent is xylene.

[0054] The initiator is benzoyl peroxide. The curing agent is N-methoxyacrylamide.

[0055] A second aspect of the present embodiment provides a method for preparing a one-component acrylic pressure-sensitive adhesive, comprising at least the following steps:

[0056] S1, 100 parts of the first solvent and all of the second solvent are mixed to form a mixed solvent 1, and the mixed solvent 1 is mixed with an initiator to form a mixed solvent 2; 20 parts of the first solvent and all of the curing agent are mixed to form a mixed solvent 3;

[0057] S2, add all the monomers and the remaining first solvent into a four-necked flask, turn on the water bath to heat to 80°C, condense and stir, the stirring rate is 160r / min, after reflux in the flask, add 3 / 4 volume of mixed solvent 2 dropwise, the addition time is 2.5h, and keep warm for 1h;

[0058] S3, adding the remaining mixed solvent 2 dropwise for 1 hour, and keeping warm at 80°C for 2 hours;

[0059] S4, add the mixed solvent 3 and stir evenly to obtain.

[0060] Comparative Example 1

[0061] The first aspect of this comparative example provides a one-component acrylic pressure-sensitive adhesive, and its preparation raw materials include, by weight: 151 parts of monomers, 230 parts of a first solvent, 10 parts of a second solvent, 0.35 parts of an initiator, and 8 parts of a curing agent; the monomers include soft monomers, hard monomers, and functional monomers.

[0062] The soft monomer is methoxyethyl acrylate; the hard monomer is methyl acrylate; and the functional monomer is acrylic acid.

[0063] The mass ratio of the soft monomer, the hard monomer and the functional monomer is 105:35:11.

[0064] The first solvent is ethyl acetate. The second solvent is xylene.

[0065] The initiator is benzoyl peroxide. The curing agent is N-methoxyacrylamide.

[0066] The second aspect of this comparative example provides a method for preparing a one-component acrylic pressure-sensitive adhesive, which comprises at least the following steps:

[0067] S1, 140 parts of the first solvent and all of the second solvent are mixed to form a mixed solvent 1, and the mixed solvent 1 is mixed with an initiator to form a mixed solvent 2; 20 parts of the first solvent and all of the curing agent are mixed to form a mixed solvent 3;

[0068] S2, add all the monomers and the remaining first solvent into a four-necked flask, turn on the water bath to heat to 80°C, condense and stir, the stirring rate is 160r / min, after reflux in the flask, add 3 / 4 volume of mixed solvent 2 dropwise, the addition time is 2.5h, and keep warm for 1h;

[0069] S3, adding the remaining mixed solvent 2 dropwise for 1 hour, and keeping warm at 80°C for 2 hours;

[0070] S4, add the mixed solvent 3 and stir evenly to obtain.

[0071] Comparative Example 2

[0072] The specific implementation of this comparative example is the same as that of Example 1, except that the soft monomer is isooctyl acrylate.

[0073] Comparative Example 3

[0074] The specific implementation of this comparative example is the same as that of Example 1, except that the soft monomer is a combination of isooctyl acrylate and methoxyethyl acrylate; and the mass ratio of isooctyl acrylate to methoxyethyl acrylate is 70:35.

[0075] Comparative Example 4

[0076] The specific implementation of this comparative example is the same as that of Example 1, except that the soft monomer is a combination of isooctyl acrylate and methoxyethyl acrylate; and the mass ratio of isooctyl acrylate to methoxyethyl acrylate is 35:70.

[0077] Comparative Example 5

[0078] The specific implementation of this comparative example is the same as that of Example 1, except that the curing agent is aluminum acetylacetonate.

[0079] Comparative Example 6

[0080] The specific implementation of this comparative example is the same as that of Example 1, except that the curing agent is ethylenediamine and the functional monomer is ethyl acetoacetoxy methacrylate.

[0081] Comparative Example 7

[0082] The specific implementation of this comparative example is the same as that of Example 1, except that the initiator is azobisisobutyronitrile.

[0083] Comparative Example 8

[0084] The specific implementation method of this comparative example is the same as that of Example 1, except that the prepared raw material does not contain the second solvent, the viscosity is high during the experiment, and the pole climbing phenomenon occurs, and the experiment is finally terminated.

[0085] Performance Testing

[0086] 1. Swelling degree test: The pressure-sensitive adhesives prepared in Example 1 and Comparative Examples 2-4 were dried into films, and the film samples were immersed in 60°C Cosso R32 lubricating oil, and taken out after 24 hours. The appearance before and after immersion was recorded and the weight was weighed to calculate the swelling degree. The results are shown in Table 1.

[0087] Table 1

[0088] sample Swelling degree (%) Appearance Example 1 6 <![CDATA[Colorless turns yellow, with a volume of approximately 1.56 cm 3 > Comparative Example 2 126 <![CDATA[Colorless to yellow, volume about 4 cm 3 > Comparative Example 3 78 <![CDATA[Colorless turns yellow, with a volume of approximately 3.06 cm 3 > Comparative Example 4 32 <![CDATA[Colorless to yellow, volume approximately 2.4 cm 3 >

[0089] 2. Viscosity test: The pressure-sensitive adhesives prepared in Examples 1-2 and Comparative Example 1 were subjected to viscosity tests. The test results are shown in Table 2.

[0090] Table 2

[0091] sample Viscosity (MPa·s) Example 1 2760 Example 2 2563 Comparative Example 1 21053

[0092] 3. Peel strength, residual adhesive rate and storage stability test: The samples prepared in Example 1 and Comparative Examples 5-7 were tested for peel strength, residual adhesive rate and storage stability. The test method is as follows:

[0093] Coating: On the PET film (corona surface, 20cm*30cm), use a four-sided wet film preparation device to evenly coat the sample with a 50μm thick adhesive layer. Then put the PET film with the adhesive layer into an oven at 120℃ and take it out after 5 minutes to evaporate the solvent and unreacted monomers. To protect the adhesive surface, attach the release paper to the adhesive surface and use a rubber roller (2kg) to roll it so that the release paper and the adhesive surface are closely attached. Let the prepared tape stand at room temperature for 1 day, and then perform performance tests.

[0094] Peel strength test: The 180° peel test of the tape was carried out according to standard PSTC-101. The tape was cut into long strips and then attached to a clean stainless steel plate that had been pre-cleaned with acetone. The tape was then rolled back and forth 3 times using a rubber roller (2kg) to remove bubbles from the bonding interface, and the test specimen was placed at room temperature for 30 minutes. A 180° peel test was performed on the tape using a PT-501B electronic peeling machine (Kunshan Beidou Precision Instrument Co., Ltd.), and the peeling speed in the experiment was fixed at 300 mm / min.

[0095] Residual adhesive rate: The location of the adhesive residue area on the steel plate is marked in red in the photo and evaluated using Image J software. The percentage of the residual adhesive area is identified and calculated by Image J software and recorded as the residual adhesive rate. Each tape sample is measured three times and the average value is taken as the final result.

[0096] Storage stability test: Preliminarily determine whether the appearance, viscosity, and solid content of the glue are qualified. If qualified, further test the peel strength, swelling degree, residual glue rate and other properties to determine its storage stability.

[0097] The results are shown in Table 3, where “ / ” indicates that the test was not performed.

[0098] Table 3

[0099]

Claims

1. A one-component acrylic pressure-sensitive adhesive, characterized in that: The raw materials for its preparation include, by weight: 138-161 parts of monomer, 190-210 parts of first solvent, 10-50 parts of second solvent, 0.1-0.5 parts of initiator, and 6-9 parts of curing agent; the monomer includes at least one of soft monomer, hard monomer, and functional monomer.

2. The one-component acrylic pressure-sensitive adhesive according to claim 1, characterized in that: The monomers include soft monomers, hard monomers and functional monomers.

3. The one-component acrylic pressure-sensitive adhesive according to claim 2, characterized in that: The mass ratio of the soft monomer, the hard monomer and the functional monomer is (100-110):(30-40):(8-11).

4. The one-component acrylic pressure-sensitive adhesive according to claim 2, characterized in that: The soft monomer includes at least one of methoxyethyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, butyl acrylate, and isooctyl acrylate; the hard monomer includes at least one of methyl acrylate, methyl methacrylate, and vinyl acetate; and the functional monomer includes at least one of acrylic acid, β-carboxyethyl acrylate, and methpropylene.

5. The one-component acrylic pressure-sensitive adhesive according to claim 1, characterized in that: The first solvent and the second solvent are both selected from at least one of ethyl acetate and xylene.

6. The one-component acrylic pressure-sensitive adhesive according to claim 1, characterized in that: The curing agent is an amide curing agent.

7. A method for preparing the one-component acrylic pressure-sensitive adhesive according to any one of claims 1 to 6, characterized in that: At least the following steps are included: S1, 50-60wt% of the first solvent and all of the second solvent are mixed to form a mixed solvent 1, and the mixed solvent 1 is mixed with an initiator to form a mixed solvent 2; 9-11wt% of the first solvent and all of the curing agent are mixed to form a mixed solvent 3; S2, add all the monomers and the remaining first solvent into a four-necked flask, turn on water bath heating, condensation and stirring, add 3 / 4 volume of mixed solvent 2 after reflux in the flask, and keep warm; S3, adding the remaining mixed solvent 2 and keeping warm; S4, add the mixed solvent 3 and stir evenly to obtain.

8. The method for preparing a one-component acrylic pressure-sensitive adhesive according to claim 7, characterized in that: In the step S2, 3 / 4 of the mass of the mixed solvent 2 is added dropwise, and the time of the addition is 2-3 hours.

9. The method for preparing a one-component acrylic pressure-sensitive adhesive according to claim 7, characterized in that: The remaining mixed solvent 2 in step S3 is added dropwise, and the time of the addition is 0.5-1.5 hours.

10. The method for preparing a one-component acrylic pressure-sensitive adhesive according to any one of claims 7 to 9, characterized in that: The insulation time in step S2 is 0.5-1.5 h; the insulation time in step S3 is 1.5-2.5 h.

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