CN116622310A - A pressure-sensitive adhesive with micro-foaming self-locking function, pressure-sensitive adhesive tape and preparation method - Google Patents

Abstract

The invention discloses a pressure-sensitive adhesive with a micro-foaming self-locking function, a pressure-sensitive adhesive tape and a preparation method thereof. The pressure-sensitive adhesive is prepared from the following raw materials in parts by weight: 20-30 parts of natural rubber; 10-20 parts of synthetic rubber; 5-15 parts of modified elastomer; 30-50 parts of a solvent; 5-10 parts of tackifier; 1-5 parts of curing agent; 0.3-1 part of antioxidant; the modified elastomer is a hydroxyl-terminated elastomer containing isocyanate structures in molecular chains. The pressure-sensitive adhesive can obviously improve the shearing strength and the bonding strength through the added high molecular weight modified elastomer, and in addition, the pressure-sensitive adhesive is tightly combined with an adhesive, so that the corrosion of water and air to an adhesive interface can be prevented, the reduction of the bonding strength is prevented, and the service life of the pressure-sensitive adhesive is prolonged.

Description

A pressure-sensitive adhesive with micro-foaming self-locking function, pressure-sensitive adhesive tape and preparation method

technical field

The invention relates to the field of pressure-sensitive adhesive tapes, in particular to a pressure-sensitive adhesive with a micro-foaming self-locking function, a pressure-sensitive adhesive tape and a preparation method.

Background technique

The full name of pressure-sensitive adhesive is pressure-sensitive adhesive (Pressure sensitive adhesive), which means that the adhesive can be immediately bonded to the adherend by using pressure, and if it is torn off from the adhesive surface of the adherend, the adhesive will not Contaminate the surface of the adherend. The characteristics of pressure-sensitive adhesive are that it is easy to stick, not difficult to remove, and not damaged when peeled off, and the adhesive layer will not dry up in a long period of time. It is mainly used in the manufacture of pressure-sensitive adhesive products such as pressure-sensitive tapes, adhesive sheets, and pressure-sensitive labels, and is widely used in the identification of light industry packaging, automobile manufacturing, machinery and building materials, aerospace, electronic appliances, medical and health care, and family life. , sealing, protection, shielding, fixing, insulation, binding and enhanced bonding.

Solvent-based pressure-sensitive adhesives have become the main form of pressure-sensitive adhesives due to their advantages such as low relative molecular weight, large initial viscosity, fast drying, good water resistance, wide application range, and good compatibility. However, the existing ordinary solvent-based pressure-sensitive adhesives have the problem that the bonding strength and shearing strength are difficult to be compatible. This is because the selection of lower molecular weight polymers is beneficial to improve the bonding strength, but it also determines the insufficient cohesion of the colloid. , which directly leads to its weak shear strength and poor colloidal anti-slip ability.

Contents of the invention

In order to solve the problem that the bonding strength and shearing strength of the existing common solvent-type pressure-sensitive adhesives are difficult to be compatible, the invention discloses a pressure-sensitive adhesive with a micro-foaming self-locking function, a pressure-sensitive tape and a preparation method.

The technical scheme adopted in the present invention is:

A pressure-sensitive adhesive with micro-foaming self-locking function, the pressure-sensitive adhesive is made of the following raw materials in parts by weight:

The modified elastomer is a hydroxyl-terminated elastomer containing an isocyanate structure in its molecular chain.

Preferably, the preparation method of the modified elastomer is: take 50 parts of hydroxyl-terminated elastomer, add 100-200 parts of toluene solution, stir to dissolve completely, add 40-75 parts of isocyanate, continue stirring and dissolving , slowly warming up to 50-60°C, continuing the reaction for 1.5-3 hours, and removing the solvent under reduced pressure.

Preferably, the hydroxyl-terminated elastomer is at least one of hydroxyl-terminated polybutadiene rubber, hydroxyl-terminated nitrile rubber or hydroxyl-terminated styrene-butadiene rubber.

Preferably, the isocyanate is one or two of toluene diisocyanate, diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate or hexamethylene diisocyanate.

Preferably, the synthetic rubber is two or more of styrene-butadiene rubber, nitrile rubber, neoprene, butadiene rubber or isoprene rubber.

Preferably, the solvent is one of toluene, xylene, n-hexane or white oil.

Preferably, the tackifier is one of terpene resin, C9 petroleum resin or C5 petroleum resin.

Preferably, the curing agent is at least one of benzoyl peroxide, tert-butyl benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile or azobisisoheptanonitrile.

Preferably, the antioxidant is one of antioxidant 1010, antioxidant 264, antioxidant 1076 or antioxidant CA.

The preparation method of any one of the above-mentioned pressure-sensitive adhesives with micro-foaming self-locking function includes: taking a 500ml three-necked flask, adding 30-50 parts of organic solvent, starting to stir, adding 20-30 parts of natural rubber, 10 - 20 parts of synthetic rubber, 5-15 parts of modified elastomer, 5-10 parts of tackifying resin, stir and dissolve completely, add 1-5 parts of curing agent and 0.3-1 part of antioxidant, and continue to react 10-20 hours, that is.

A pressure-sensitive adhesive tape is prepared by coating and thermally curing any one of the above-mentioned pressure-sensitive adhesives with micro-foaming self-locking function.

Beneficial effects: the pressure-sensitive adhesive of the present invention improves the cohesion and shear strength of the pressure-sensitive adhesive by adding a high-molecular-weight modified elastomer, and when the adhesive is bonded to the surface of an object, the isocyanate in the modified elastomer will It absorbs air or moisture on the surface of the adherend to react within 6-12 hours, producing unstable carbamic acid, which is further decomposed into amine and carbon dioxide. Foaming, resulting in micro-expansion, so even if a higher molecular weight colloidal polymer is added, under the action of the overall adhesive strength of the pressure-sensitive adhesive, the micro-foaming part will inject the adhesive colloid into the surface of the adherend In the gap, a mortise and tenon self-locking structure is formed, and the purpose of enhancing the bonding strength is finally achieved. Moreover, by controlling the content of isocyanate, the degree of swelling can be controlled. The pressure-sensitive adhesive tape prepared by the pressure-sensitive adhesive of the present invention has extremely high bonding strength compared with ordinary pressure-sensitive adhesive, and it can actively inject the colloid into the gap of the adherend by using its own micro-expansion effect to strengthen the adhesion of the adhesive tape. At the same time of bonding strength, it also fills the gap between the colloid and the adherend, prevents the erosion of water and oxygen, prevents the attenuation of the bonding strength of the colloid due to aging, and prolongs the service life of the pressure-sensitive adhesive.

Detailed ways:

The present invention will be described in detail through examples below, but the present invention is not limited thereby.

In the following examples, the materials used can be obtained commercially, wherein:

Natural rubber is purchased from Hengshui Yaguan Rubber Products Co., Ltd.;

Styrene butadiene rubber, nitrile rubber, neoprene and butadiene rubber were purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Hydroxyl-terminated polybutadiene rubber is purchased from Jingjiang Tonggao Chemical Co., Ltd.;

Hydroxyl-terminated nitrile rubber and hydroxy-terminated styrene-butadiene rubber were purchased from Shandong Weishang Chemical Co., Ltd.;

Toluene diisocyanate was purchased from Anqiu Pengchen Thermal Insulation Material Co., Ltd.;

Hexamethylene diisocyanate was purchased from Qingdao Dexin Chemical Co., Ltd.;

Diphenylmethane diisocyanate was purchased from Pande (Shanghai) International Trading Co., Ltd.;

1,6-Hexyl diisocyanate was purchased from Qingdao Yishi Chemical Co., Ltd.;

Toluene and xylene were purchased from Merck Chemicals;

Terpene resin and C5 petroleum resin were purchased from Shandong Guangshen Electronic Technology Co., Ltd.;

Benzoyl peroxide and azobisisobutyronitrile were purchased from Jiangsu Quanwei Chemical Co., Ltd.;

Antioxidant 1010 and antioxidant CA were purchased from Shanghai Huajue Materials Co., Ltd.

Embodiment one:

A pressure-sensitive adhesive with micro-foaming self-locking function, its formula is (parts by mass):

1), preparation of modified elastomer:

Take 50 parts of hydroxyl-terminated polybutadiene rubber and add it to a 500ml three-necked flask, add 100 parts of toluene solution, stir to dissolve completely, add 65 parts of toluene diisocyanate, continue stirring and dissolving, slowly raise the temperature to 50°C, and continue After reacting for 2 hours, the solvent was removed under reduced pressure to obtain the desired modified elastomer.

2), the preparation of pressure-sensitive adhesive:

Take a 500ml three-neck flask, add 47 parts of toluene, start stirring, add 25 parts of natural rubber, 5 parts of styrene-butadiene rubber, 5 parts of neoprene rubber, 10 parts of modified elastomer, and 5 parts of terpene resin, and stir to dissolve completely Then add 2.5 parts of benzoyl peroxide and 0.5 parts of antioxidant 1010, and continue stirring for 10 hours to obtain a pressure-sensitive collagen solution with micro-foaming self-locking function.

3), the preparation of pressure-sensitive adhesive tape:

Apply the above-mentioned pressure-sensitive adhesive on the base film, and heat-dry to obtain the pressure-sensitive adhesive tape A with micro-foaming self-locking function.

Embodiment two:

A pressure-sensitive adhesive with micro-foaming self-locking function, its formula is (parts by mass):

1), the preparation of modified elastomer:

Take 50 parts of hydroxy-terminated styrene-butadiene rubber and add it to a 500ml three-necked flask, add 150 parts of toluene solution, stir to dissolve completely, then add 75 parts of hexamethylene diisocyanate, continue stirring and dissolving, then slowly heat up to 55°C, The reaction was continued for 2 hours, and the solvent was removed under reduced pressure to obtain the desired modified elastomer.

2), the preparation of pressure-sensitive adhesive:

Take a 500ml three-neck flask, add 47 parts of toluene, start stirring, add 25 parts of natural rubber, 7.5 parts of nitrile rubber, 7.5 parts of butadiene rubber, 5 parts of modified elastomer, 5 parts of C5 petroleum resin, and stir to dissolve completely Then add 2.5 parts of azobisisobutyronitrile and 0.5 parts of antioxidant CA, and continue stirring for 10 hours to obtain a pressure-sensitive collagen solution with micro-foaming self-locking function.

3), the preparation of pressure-sensitive adhesive tape:

Apply the above-mentioned pressure-sensitive adhesive on the base film, and heat-dry to obtain the pressure-sensitive adhesive tape B with micro-foaming self-locking function.

Embodiment three:

A pressure-sensitive adhesive with micro-foaming self-locking function, its formula is (parts by mass):

1), the preparation of modified elastomer:

Take 50 parts of hydroxyl-terminated nitrile rubber and add it to a 500ml three-necked flask, add 150 parts of toluene solution, stir to dissolve completely, add 60 parts of diphenylmethane diisocyanate, continue stirring and dissolving, then slowly heat up to 55°C, The reaction was continued for 2.5 hours, and the solvent was removed under reduced pressure to obtain the desired modified elastomer.

2), the preparation of pressure-sensitive adhesive:

Take a 500ml three-neck flask, add 35 parts of xylene, start stirring, add 20 parts of natural rubber, 10 parts of nitrile rubber, 10 parts of neoprene, 15 parts of modified elastomer, 7 parts of C5 petroleum resin, and stir completely After dissolving, add 2.5 parts of azobisisobutyronitrile and 0.5 parts of antioxidant CA, and continue stirring for 10 hours to obtain a pressure-sensitive collagen solution with micro-foaming self-locking function.

3), the preparation of pressure-sensitive adhesive tape:

Apply the above-mentioned pressure-sensitive adhesive on the base film, and heat-dry to obtain the pressure-sensitive adhesive tape C with micro-foaming self-locking function.

Embodiment four:

A pressure-sensitive adhesive with micro-foaming self-locking function, its formula is (parts by mass):

1), preparation of modified elastomer:

Take 25 parts of hydroxyl-terminated polybutadiene rubber and 25 parts of hydroxyl-terminated nitrile rubber into a 500ml three-necked flask, add 125 parts of toluene solution, stir to dissolve completely, then add 45 parts of 1,6-hexamethylene diisocyanate , after continuing to stir and dissolve, slowly raise the temperature to 50°C, continue the reaction for 3 hours, and remove the solvent under reduced pressure to obtain the desired modified elastomer.

2), the preparation of pressure-sensitive adhesive:

Take a 500ml three-neck flask, add 35 parts of xylene, start stirring, add 30 parts of natural rubber, 5 parts of styrene-butadiene rubber, 5 parts of butadiene rubber, 15 parts of modified elastomer, 7 parts of terpene resin, and stir completely After dissolving, add 2.5 parts of benzoyl peroxide and 0.5 parts of antioxidant 1010, and continue stirring for 10 hours to obtain a pressure-sensitive collagen solution with micro-foaming self-locking function.

3), the preparation of pressure-sensitive adhesive tape:

Apply the above-mentioned pressure-sensitive adhesive on the base film, and heat-dry to obtain the pressure-sensitive adhesive tape D with micro-foaming self-locking function.

Comparative example 1

Adopt common synthetic rubber to replace the modified elastomer in embodiment 1, concrete formula is:

1), the preparation of pressure-sensitive adhesive:

Take a 500ml three-neck flask, add 47 parts of toluene, start stirring, add 25 parts of natural rubber, 5 parts of styrene-butadiene rubber, 5 parts of neoprene rubber, 10 parts of butadiene rubber, 5 parts of terpene resin, and stir to dissolve completely Add 2.5 parts of benzoyl peroxide and 0.5 parts of antioxidant 1010, and continue stirring for 10 hours to obtain a pressure-sensitive collagen solution.

2), the preparation of pressure-sensitive adhesive tape:

Apply the above-mentioned pressure-sensitive adhesive on the base film, and heat-dry to obtain the pressure-sensitive adhesive tape E.

Performance Testing

The pressure-sensitive adhesive tapes A, B, C, D, and E prepared above were respectively bonded to the same metal plate, and their bonding strength and shear strength after 12 hours were tested respectively. The test results are shown in Table 1. in:

For the test method of adhesive strength, refer to GB/T 2792: Test method for peel strength of adhesive tape;

The test method of shear strength refers to GB/T 33332: Experimental method of dynamic shear strength of adhesive tape.

Table 1

It can be seen from Table 1 that, compared with the existing pressure-sensitive adhesive, the bonding strength of the pressure-sensitive adhesive of the present invention is increased by 20% to 40%, and the effect of improving the shear strength is also obvious. The invention realizes the double improvement of the bonding strength and the shearing strength by utilizing the micro-foaming technology of the pressure-sensitive adhesive.

The above are only specific implementations of the present invention, but the scope of protection of the present invention is not limited thereto, and any changes or replacements that do not come to mind through creative efforts shall fall within the scope of protection of the present invention.

Claims (11)

1. The pressure-sensitive adhesive with the micro-foaming self-locking function is characterized by being prepared from the following raw materials in parts by weight:

the modified elastomer is a hydroxyl-terminated elastomer containing isocyanate structures in molecular chains.

2. The pressure-sensitive adhesive with a micro-foaming self-locking function according to claim 1, wherein the preparation method of the modified elastomer is as follows: taking 50 parts of hydroxyl-terminated elastomer, adding 100-200 parts of toluene solution, stirring to dissolve completely, adding 40-75 parts of isocyanate, continuously stirring to dissolve, slowly heating to 50-60 ℃, continuously reacting for 1.5-3 hours, and removing the solvent under reduced pressure.

3. The pressure-sensitive adhesive with a micro-foaming self-locking function according to claim 2, wherein the hydroxyl-terminated elastomer is at least one of hydroxyl-terminated polybutadiene rubber, hydroxyl-terminated nitrile rubber or hydroxyl-terminated styrene-butadiene rubber.

4. The pressure-sensitive adhesive with the micro-foaming self-locking function according to claim 2, wherein the isocyanate is 1 or 2 of toluene diisocyanate, diphenylmethane diisocyanate, 1, 6-hexamethylene diisocyanate or hexamethylene diisocyanate.

5. The pressure-sensitive adhesive with the micro-foaming self-locking function according to claim 1, wherein the synthetic rubber is more than two of styrene-butadiene rubber, nitrile rubber, chloroprene rubber, butadiene rubber or isoprene rubber.

6. The pressure-sensitive adhesive with the micro-foaming self-locking function according to claim 1, wherein the solvent is one of toluene, xylene, n-hexane or white oil.

7. The pressure-sensitive adhesive with a micro-foaming self-locking function according to claim 1, wherein the tackifier is one of terpene resin, C9 petroleum resin or C5 petroleum resin.

8. The pressure-sensitive adhesive with the micro-foaming self-locking function according to claim 1, wherein the curing agent is at least one of benzoyl peroxide, benzoyl tert-butyl peroxide, dicumyl peroxide, azobisisobutyronitrile or azobisisoheptonitrile.

9. The pressure-sensitive adhesive with the micro-foaming self-locking function according to claim 1, wherein the antioxidant is one of antioxidant 1010, antioxidant 264, antioxidant 1076 or antioxidant CA.

10. The method for preparing the pressure-sensitive adhesive with the micro-foaming self-locking function as claimed in claims 1 to 9, which is characterized by comprising the following steps: adding 30-50 parts of organic solvent into a 500ml three-neck flask, starting stirring, adding 20-30 parts of natural rubber, 10-20 parts of synthetic rubber, 5-15 parts of modified elastomer and 5-10 parts of tackifying resin, stirring to dissolve completely, adding 1-5 parts of curing agent and 0.3-1 part of antioxidant, and continuously reacting for 10-20 hours to obtain the modified polyurethane foam.

11. A pressure-sensitive adhesive tape, characterized in that it is prepared by coating and thermosetting the pressure-sensitive adhesive with micro-foaming self-locking function according to any one of claims 1 to 9.