High-viscosity fast-curing direct-recovery pressure-sensitive adhesive, protective film and preparation method of high-viscosity fast-curing direct-recovery pressure-sensitive adhesive

Abstract

The invention relates to the technical field of adhesive preparation, and particularly discloses a high-viscosity fast-curing direct-recovery pressure-sensitive adhesive, a protective film and a preparation method of the high-viscosity fast-curing direct-recovery pressure-sensitive adhesive. The high-viscosity fast-curing direct-recovery pressure-sensitive adhesive is prepared from the following raw materials: a mixed monomer, methyl acrylate, methyl methacrylate, acrylic acid, an initiator and a solvent, the mixed monomer comprises butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, hydroxyethyl methylacrylate and butyl methacrylate. Researches show that the high-viscosity fast-curing direct-recovery type pressure-sensitive adhesive disclosed by the invention has relatively high peel strength; the peel strength before curing and after curing is 64gf / 25mm or above, and compared with the prior art, the peel strength is remarkably improved; the method has very important application value.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive preparation, and in particular to a high-viscosity, fast-curing, direct-shrinking pressure-sensitive adhesive, a protective film and a preparation method thereof. Background Art

[0002] Single-layer direct-receiving products have the advantages of easy rewinding, beautiful appearance, no bubbles or orange peel, and convenient tearing and sticking, but due to the single-layer nature, the product's adhesive strength has always been relatively low, resulting in a relatively narrow range of product applications. Blindly increasing the product's adhesive strength (reducing the amount of curing agent or increasing the thickness of the dry glue) may result in an insignificant increase in peel strength, and may even cause the adhesive layer to be torn apart when the product is torn apart, which may increase the risk of glue falling off. The adhesive designed by the present invention focuses on improving the peel strength of the product while ensuring the direct-receiving effect, and solves the problem that the curing degree of the adhesive layer cannot be taken into account when the peel strength is high.

[0003] There has always been a relatively large demand for 50-80g direct-collection products in the market, which are mainly used for process protection of panels. In addition to the peel strength requirements, the appearance requirements are also relatively high, requiring no bubble marks and no orange peel. The peel strength of the finished products of the existing adhesive system is mostly below 20g, which does not meet the market demand. Therefore, the peel strength of the product needs to be improved. Summary of the invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive, a protective film and a preparation method thereof.

[0005] The above technical problems to be solved by the present invention are achieved through the following technical solutions:

[0006] The present invention first provides a high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive, the preparation raw materials of which include mixed monomers, methyl acrylate, methyl methacrylate, acrylic acid, an initiator and a solvent;

[0007] The mixed monomers include butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate and butyl methacrylate.

[0008] Preferably, the high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive comprises the following components in parts by weight:

[0009] 15-25 parts of butyl acrylate; 5-15 parts of isooctyl acrylate; 0.5-1 parts of hydroxyethyl acrylate; 0.5-1 parts of hydroxyethyl methacrylate; 1-2 parts of butyl methacrylate; 1-2 parts of methyl acrylate; 1-2 parts of methyl methacrylate; 1-2 parts of acrylic acid; 0.1-0.2 parts of initiator; 55-65 parts of solvent.

[0010] Most preferably, the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive comprises the following components in parts by weight:

[0011] 20 parts of butyl acrylate; 10 parts of isooctyl acrylate; 0.7 part of 2-hydroxyethyl acrylate; 0.7 part of 2-hydroxyethyl methacrylate; 1.8 parts of butyl methacrylate; 1.8 parts of methyl acrylate; 1.8 parts of methyl methacrylate; 1.1 parts of acrylic acid; 0.15 part of initiator; 60 parts of solvent.

[0012] Preferably, the initiator is azobisisobutyronitrile.

[0013] Preferably, the solvent is selected from one or more of ethyl acetate, toluene and acetone.

[0014] The present invention also provides a method for preparing the above-mentioned high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive, which comprises the following steps:

[0015] (1) Add the first part of monomers, the first part of acrylic acid, methyl acrylate and methyl methacrylate, the first part of solvent, and the first part of initiator into a reaction kettle, heat up to 85-87 °C, and keep warm for 80-90 minutes after reflux starts;

[0016] (2) Add the second part of solvent and the second part of initiator into the reaction kettle, keep the temperature in the kettle at 83-84.5 °C, and keep warm for 120 minutes;

[0017] (3) Add the third part of solvent and the third part of initiator into the reaction kettle, keep the temperature in the kettle at 86-88 °C, and keep warm for 120 minutes;

[0018] (4) Add the second part of monomers, the second part of acrylic acid, methyl acrylate and methyl methacrylate, and the fourth part of solvent into the reaction kettle, keep the temperature in the kettle at 83-85 °C, and keep warm for 120 minutes;

[0019] (5) Add the fourth part of initiator and the fifth part of solvent into the reaction kettle, keep the temperature in the kettle at 81-83 °C, and keep warm for 120 minutes;

[0020] (6) Add the fifth part of initiator and the sixth part of solvent into the reaction kettle, keep the temperature in the kettle at 78-81 °C, and keep warm for 180 minutes; after the reaction ends, lower the external temperature and add the seventh part of solvent into the reaction kettle. When the internal temperature drops to 30-40 °C, discharge to obtain the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive.

[0021] Preferably, the dosage of the first part of monomers is 60% of the total weight of monomers; the dosage of the second part of monomers is 40% of the total weight of monomers.

[0022] Preferably, the dosage of the first part of acrylic acid, methyl acrylate, and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate, and methyl methacrylate; the dosage of the second part of acrylic acid, methyl acrylate, and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate, and methyl methacrylate.

[0023] Preferably, the dosage of the first part of the initiator is 37% of the total weight of the initiator; the dosage of the second part of the initiator is 3% of the total weight of the initiator; the dosage of the third part of the initiator is 3% of the total weight of the initiator; the dosage of the fourth part of the initiator is 17% of the total weight of the initiator; the dosage of the fifth part of the initiator is 40% of the total weight of the initiator.

[0024] Preferably, the dosage of the first part of the solvent is 37% of the total weight of the solvent; the dosage of the second part of the solvent is 3% of the total weight of the solvent; the dosage of the third part of the solvent is 3% of the total weight of the solvent; the dosage of the fourth part of the solvent is 10% of the total weight of the solvent; the dosage of the fifth part of the solvent is 17% of the total weight of the solvent; the dosage of the sixth part of the solvent is 10% of the total weight of the solvent; the dosage of the seventh part of the solvent is 20% of the total weight of the solvent.

[0025] The present invention also provides a protective film, which is prepared from the above-mentioned high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive.

[0026] Beneficial effects: The present invention provides a brand-new high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive; research shows that the high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive of the present invention has a relatively high peel strength; its peel strength before and after curing is above 64 gf / 25 mm, and compared with the prior art, it has been significantly improved; it has very important application value. Detailed implementation manners

[0027] The following specific examples are used to further explain the present invention, but the examples do not limit the present invention in any form.

[0028] Example 1 Preparation of high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive

[0029] Component parts by weight of raw materials: 20 parts of butyl acrylate; 10 parts of isooctyl acrylate; 0.7 part of 2-hydroxyethyl acrylate; 0.7 part of 2-hydroxyethyl methacrylate; 1.8 parts of butyl methacrylate; 1.8 parts of methyl acrylate; 1.8 parts of methyl methacrylate; 1.1 parts of acrylic acid; 0.15 part of initiator (azobisisobutyronitrile); 60 parts of solvent (ethyl acetate).

[0030] Preparation method:

[0031] (1) Add the first part of the monomer, the first part of acrylic acid, methyl acrylate, and methyl methacrylate, the first part of the solvent, and the first part of the initiator to the reaction kettle, heat up to 86 °C, and keep the temperature for 85 minutes after the reflux starts;

[0032] (2) Add the second part of the solvent and the second part of the initiator to the reaction kettle, keep the temperature in the kettle at 84 °C, and keep the temperature for 120 minutes;

[0033] (3) Add the third part of the solvent and the third part of the initiator to the reaction kettle, keep the temperature in the kettle at 87 °C, and keep the temperature for 120 minutes;

[0034] (4) Add the second part of the monomer, the second part of acrylic acid, methyl acrylate, and methyl methacrylate, and the fourth part of the solvent to the reaction kettle, keep the temperature in the kettle at 84 °C, and keep the temperature for 120 minutes;

[0035] (5) Add the fourth part of the initiator and the fifth part of the solvent to the reaction kettle, keep the temperature in the kettle at 82 °C, and keep the temperature for 120 minutes;

[0036] (6) Add the fifth part of the initiator and the sixth part of the solvent to the reaction kettle, keep the temperature in the kettle at 80 °C, and keep the temperature for 180 minutes; after the reaction ends, lower the external temperature and add the seventh part of the solvent to the reaction kettle. When the internal temperature drops to 35 °C, discharge the material to obtain the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive;

[0037] Among them, the dosage of the first part of the monomer is 60% of the total weight of the monomer; the dosage of the second part of the monomer is 40% of the total weight of the monomer;

[0038] The dosage of the first part of acrylic acid, methyl acrylate, and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate, and methyl methacrylate; the dosage of the second part of acrylic acid, methyl acrylate, and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate, and methyl methacrylate;

[0039] The dosage of the first part of the initiator is 37% of the total weight of the initiator; the dosage of the second part of the initiator is 3% of the total weight of the initiator; the dosage of the third part of the initiator is 3% of the total weight of the initiator; the dosage of the fourth part of the initiator is 17% of the total weight of the initiator; the dosage of the fifth part of the initiator is 40% of the total weight of the initiator;

[0040] The dosage of the first part of the solvent is 37% of the total weight of the solvent; the dosage of the second part of the solvent is 3% of the total weight of the solvent; the dosage of the third part of the solvent is 3% of the total weight of the solvent; the dosage of the fourth part of the solvent is 10% of the total weight of the solvent; the dosage of the fifth part of the solvent is 17% of the total weight of the solvent; the dosage of the sixth part of the solvent is 10% of the total weight of the solvent; the dosage of the seventh part of the solvent is 20% of the total weight of the solvent.

[0041] Example 2 Preparation of a High-Viscosity, Fast-Curing, Direct-Receiving Type Pressure-Sensitive Adhesive

[0042] Component parts by weight of raw materials: 15 parts of butyl acrylate; 15 parts of isooctyl acrylate; 0.5 part of 2-hydroxyethyl acrylate; 0.5 part of 2-hydroxyethyl methacrylate; 1 part of butyl methacrylate; 2 parts of methyl acrylate; 2 parts of methyl methacrylate; 1 part of acrylic acid; 0.1 part of initiator (azobisisobutyronitrile); 55 parts of solvent (ethyl acetate).

[0043] The preparation method is the same as that in Example 1.

[0044] Example 3 Preparation of a High-Viscosity, Fast-Curing, Direct-Receiving Type Pressure-Sensitive Adhesive

[0045] Component parts by weight of raw materials: 25 parts of butyl acrylate; 5 parts of isooctyl acrylate; 1 part of 2-hydroxyethyl acrylate; 1 part of 2-hydroxyethyl methacrylate; 2 parts of butyl methacrylate; 1 part of methyl acrylate; 1 part of methyl methacrylate; 2 parts of acrylic acid; 0.2 part of initiator (azobisisobutyronitrile); 65 parts of solvent (ethyl acetate).

[0046] The preparation method is the same as that in Example 1.

[0047] Example 4 Preparation of a Protective Film

[0048] Component parts by weight of raw materials: 40 parts of the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive prepared in Example 1; curing agent: 0.6 part of diphenylmethane diisocyanate; 0.2 part of hexamethylene diisocyanate; 0.2 part of additive zinc 2-ethylhexanoate; 60 parts of solvent ethyl acetate;

[0049] Preparation method: Add the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive prepared in Example 1 and the solvent to a dispersion tank and stir and mix for 20 minutes, then add the curing agent in three portions, with a 10-minute stirring time interval for each addition of the curing agent, and finally add the additive and stir for 10 minutes to obtain a mixed solution; coat the mixed solution with a coater to obtain the protective film.

[0050] Example 5 Preparation of a Protective Film

[0051] Component parts by weight of raw materials: 45 parts of the high-viscosity, fast-curing, direct-receiving type pressure-sensitive adhesive prepared in Example 2; curing agent: 1 part of diphenylmethane diisocyanate; 0.4 part of hexamethylene diisocyanate; 0.4 part of additive zinc 2-ethylhexanoate; 55 parts of solvent ethyl acetate;

[0052] Preparation method: Add the high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive prepared in Example 1 and the solvent into a dispersion tank and stir and mix for 20 minutes. Then add the curing agent in three portions, with a stirring time of 10 minutes between each addition of the curing agent. Finally, add the additive and stir for 10 minutes to obtain a mixed solution; coat the mixed solution with a coater to obtain the protective film.

[0053] Preparation of the protective film in Example 6

[0054] Composition by weight of raw materials: 35 parts of the high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive prepared in Example 3; Curing agent: 0.5 part of diphenylmethane diisocyanate; 0.5 part of hexamethylene diisocyanate; 0.2 part of 2-ethylhexanoic acid zinc as the additive; 65 parts of ethyl acetate as the solvent;

[0055] Preparation method: Add the high-viscosity fast-curing direct-receiving type pressure-sensitive adhesive prepared in Example 1 and the solvent into a dispersion tank and stir and mix for 20 minutes. Then add the curing agent in three portions, with a stirring time of 10 minutes between each addition of the curing agent. Finally, add the additive and stir for 10 minutes to obtain a mixed solution; coat the mixed solution with a coater to obtain the protective film

[0056] Refer to the standard of GB / T 2792-2014 to test the peel strength (sticking to A steel plate) of the protective films prepared in Examples 4 to 6 before and after curing. The test results are shown in Table 1.

[0057] Table 1. Test results of the peel strength of the protective film

[0058]

Claims

1. A high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive, characterized in that: The preparation raw materials include mixed monomers, methyl acrylate, methyl methacrylate, acrylic acid, an initiator and a solvent; The mixed monomers include butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate and butyl methacrylate.

2. The high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive according to claim 1, characterized in that: Contains the following components in parts by weight: 15-25 parts of butyl acrylate; 5-15 parts of isooctyl acrylate; 0.5-1 parts of hydroxyethyl acrylate; 0.5-1 parts of hydroxyethyl methacrylate; 1-2 parts of butyl methacrylate; 1-2 parts of methyl acrylate; 1-2 parts of methyl methacrylate; 1-2 parts of acrylic acid; 0.1-0.2 parts of initiator; 55-65 parts of solvent. Most preferably, the high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive comprises the following components in parts by weight: 20 parts of butyl acrylate; 10 parts of isooctyl acrylate; 0.7 parts of hydroxyethyl acrylate; 0.7 parts of hydroxyethyl methacrylate; 1.8 parts of butyl methacrylate; 1.8 parts of methyl acrylate; 1.8 parts of methyl methacrylate; 1.1 parts of acrylic acid; 0.15 parts of initiator; 60 parts of solvent.

3. The high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive according to claim 1, characterized in that: The initiator is azobisisobutyronitrile.

4. The high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive according to claim 1, characterized in that: The solvent is selected from one or a mixture of more than one of ethyl acetate, toluene and acetone.

5. The method for preparing the high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive according to any one of claims 1 to 4, characterized in that: The following steps are included: (1) adding the first part of monomers, the first part of acrylic acid, methyl acrylate and methyl methacrylate, the first part of solvent, and the first part of initiator into a reaction kettle, heating the reaction kettle to 85-87° C., and keeping the temperature for 80-90 minutes after the reflux begins; (2) adding the second part of solvent and the second part of initiator into the reaction kettle, the temperature in the kettle is 83-84.5° C., and the insulation time is 120 minutes; (3) adding the third part of solvent and the third part of initiator into the reaction kettle, setting the temperature in the kettle to 86-88° C. and keeping the temperature for 120 minutes; (4) adding the second part of monomer, the second part of acrylic acid, methyl acrylate and methyl methacrylate, and the fourth part of solvent into the reaction kettle, with the temperature in the kettle at 83-85° C. and the holding time at this temperature for 120 minutes; (5) adding the fourth part of initiator and the fifth part of solvent into the reaction kettle, setting the temperature in the kettle to 81-83° C. and keeping the temperature for 120 minutes; (6) Add the fifth part of the initiator and the sixth part of the solvent into the reaction kettle, set the temperature inside the kettle to 78-81°C, and keep the temperature for 180 minutes; after the reaction is completed, lower the external temperature and add the seventh part of the solvent into the reaction kettle, and when the internal temperature drops to 30-40°C, discharge the material to obtain the high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive.

6. The preparation method according to claim 5, characterized in that: The amount of the first part of monomers is 60% of the total weight of the monomers; the amount of the second part of monomers is 40% of the total weight of the monomers.

7. The preparation method according to claim 5, characterized in that: The amount of the first part of acrylic acid, methyl acrylate and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate and methyl methacrylate; the amount of the second part of acrylic acid, methyl acrylate and methyl methacrylate is 50% of the total weight of acrylic acid, methyl acrylate and methyl methacrylate.

8. The preparation method according to claim 5, characterized in that: The amount of the first part of the initiator is 37% of the total weight of the initiator; the amount of the second part of the initiator is 3% of the total weight of the initiator; the amount of the third part of the initiator is 3% of the total weight of the initiator; the amount of the fourth part of the initiator is 17% of the total weight of the initiator; the amount of the fifth part of the initiator is 40% of the total weight of the initiator.

9. The preparation method according to claim 5, characterized in that: The amount of the first part of solvent is 37% of the total weight of the solvent; the amount of the second part of solvent is 3% of the total weight of the solvent; the amount of the third part of solvent is 3% of the total weight of the solvent; the amount of the fourth part of solvent is 10% of the total weight of the solvent; the amount of the fifth part of solvent is 17% of the total weight of the solvent; the amount of the sixth part of solvent is 10% of the total weight of the solvent; the amount of the seventh part of solvent is 20% of the total weight of the solvent.

10. A protective film, characterized in that: The high-viscosity, fast-curing, direct-absorbing pressure-sensitive adhesive described in any one of claims 1 to 5 is prepared.

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