CN117946581A - Single-component polyurethane primer and adhesive tape using same - Google Patents

Abstract

The invention provides a single-component polyurethane primer, which is prepared from the following raw materials: the alcohol material comprises polyester polyol, wherein the polyester polyol comprises at least one of polyethylene glycol adipate butanediol polyol, polyethylene glycol adipate diethylene glycol polyol and poly (3-methyl-1, 5-pentanediol adipate) polyol; the isocyanate material comprises diisocyanate and polyisocyanate, wherein the molecular structure of the diisocyanate and/or polyisocyanate comprises aromatic rings, and the mass ratio of the diisocyanate is as follows: polyisocyanate=6 to 12:1 to 5; auxiliaries, wherein the auxiliaries comprise a catalyst; a solvent; and the alcohol materials are calculated according to the mass ratio: isocyanate material=1 to 2:0.7 to 1.7. The single-component polyurethane primer can form a primer layer which has high surface tension, is resistant to solvents and is not easy to be corroded by the solvents in the adhesive layer, and can improve the surface tension of a base material.

Description

Single-component polyurethane primer and adhesive tape using same

Technical Field

The invention belongs to the technical field of primer, and particularly relates to a single-component polyurethane primer and an adhesive tape using the same.

Background

In many cases, when an object is bonded by using an adhesive tape or a protective film, the adhesive tape or the protective film has poor surface affinity to a base material, which tends to cause poor structural stability of the adhesive tape and poor adhesive adhesion. The PET substrate has good heat resistance, high transparency and strength, is not easy to stretch, and has lower tension control requirement than other substrates, but has poorer surface affinity, printability and ink adhesion fastness due to regular macromolecular chain structure and higher crystallinity of the PET substrate.

The common surface treatment method of the base material is a corona method, but the corona method has timeliness, and the treatment effect can be attenuated to different degrees according to different storage environment humiture and storage time. The primer is used as a pretreatment means, so that the surface tension of the base material can be increased, the structural stability of the adhesive tape or the protective film is improved, and the occurrence of the degumming phenomenon is reduced. In addition, as the primer is arranged between the base material and the adhesive layer, the adhesive property between the adhesive layer and the base material is improved, and most of commercially available adhesives contain alcohol, ester, benzene and ketone materials, so that the primer is easy to corrode.

Therefore, there is a need for a primer that can raise the surface tension of a substrate and has good solvent resistance.

Disclosure of Invention

The invention aims to provide a single-component polyurethane primer and an adhesive tape using the same, wherein the single-component polyurethane primer can form a primer layer which has high surface tension, is resistant to solvents and is not easy to corrode by solvents in an adhesive layer, and can improve the surface tension of a base material.

According to a first aspect of the present invention, there is provided a one-component polyurethane primer, the raw materials for preparing the one-component polyurethane primer comprising: the alcohol material comprises polyester polyol, wherein the polyester polyol comprises at least one of polyethylene glycol butanediol adipate Polyol (PEBA), polyethylene glycol diethylene glycol adipate Polyol (PEDA) and poly (3-methyl-1, 5-pentanediol adipate Polyol (PMA); the isocyanate material comprises diisocyanate and polyisocyanate, wherein the molecular structure of the diisocyanate and/or polyisocyanate comprises aromatic rings, and the mass ratio of the diisocyanate is as follows: polyisocyanate=6 to 12:1 to 5; auxiliaries, wherein the auxiliaries comprise a catalyst; a solvent; and the alcohol materials are calculated according to the mass ratio: isocyanate material=1 to 2:0.7 to 1.7.

The single-component polyurethane primer provided by the scheme can improve the surface tension of a base material, and the primer layer formed by the single-component polyurethane primer has high adhesive force to the base material, so that the base material layer and the primer layer can be firmly attached. Meanwhile, the primer layer has good solvent resistance and is not easy to be corroded by alcohols, esters, benzene and ketone materials, so that the adhesive tape and the protective film applying the single-component polyurethane primer have good structural stability. The scheme adopts the polyester polyol with high polarity and isocyanate materials meeting the requirements according to the proportion, and the prepared primer has high cohesive strength, can form a primer layer with high surface tension, good adhesive force, stable structure, good solvent resistance, good flexibility and good tensile strength, and is favorable for firmly attaching a base material and the primer layer. Wherein the molecular structure of the diisocyanate contains 2 isocyanate groups, and the molecular structure of the polyisocyanate contains more than 2 isocyanate groups. When the single-component polyurethane primer is used for preparing the adhesive tape, the primer layer in the adhesive tape is not easy to corrode by the adhesive, and the surface tension of a base material can be stably improved, so that the structural stability of the adhesive tape can be improved, and residual adhesive is not easy to remain on the surface of an object after the adhesive tape is torn after being attached to the surface of the object. Particularly when PET is used as a base material, the single-component polyurethane primer can obviously improve the surface tension of the PET base material, so that the bonding effect of the PET base material and the adhesive layer is improved. In addition, the single-component polyurethane primer provided by the scheme belongs to a hydroxyl-terminated polyurethane primer, is not easy to react with water, and avoids the condition that the primer expands when being foamed with water, thereby further improving the storage stability of the primer and the water resistance and solvent resistance of a primer layer.

Preferably, the auxiliary agent comprises a hydroxyl chain extender, and the molecular structure of the hydroxyl chain extender at least contains 2 hydroxyl groups; hydroxyl chain extender calculated according to mass ratio: isocyanate material=0.2 to 0.5:0.7 to 1.7. The hydroxyl chain extender at least contains 2 hydroxyl groups, so that the hydroxyl chain extender belongs to an alcohol hydroxyl chain extender, and the alcohol hydroxyl chain extender with the content is adopted to crosslink with the isocyanate materials, so that the speed of complete surface drying of the primer can be improved, the primer has the property of rapid surface drying, the primer can be directly rolled up for use after being directly dried, and the production efficiency is greatly improved.

Preferably, the hydroxyl-type chain extender includes at least one of Ethylene Glycol (EG), 1, 4-Butanediol (BDO), diethylene glycol (DEG), neopentyl glycol (NPG). When the reaction system contains hydroxyl chain extender, isocyanate materials react with the hydroxyl chain extender with small molecular weight and then react with alcohol materials to prepare primer. The inventor selects the hydroxyl chain extender with high polarity, low cost and easy purchase to be matched with the material system to prepare the primer, so that the crosslinking density of the primer can be improved, and the primer is favorable for forming a primer layer with high adhesive force, stable structure and high surface tension.

Preferably, the molecular weight of the polyester polyol is 1000 to 2000. The primer is prepared by matching the polyester polyol with the molecular weight and the isocyanate materials, so that a primer layer with moderate hardness, good flexibility and tensile strength and good solvent resistance is easily formed, and the adhesive layer structure using the primer is stable and is not easy to be left.

Preferably, the diisocyanate comprises at least one of Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI). The diisocyanate of the above kind is selected to raise cohesive strength of primer and to form primer layer with high adhesion to base material, high solvent resistance and high surface tension.

Preferably, the polyisocyanate comprises at least one of toluene diisocyanate-trimethylolpropane adduct (TDI-TMP adduct), polymethylene polyphenyl isocyanate (PAPI).

Preferably, the solvent comprises N, N-Dimethylformamide (DMF) and ethyl acetate, calculated as mass ratio: ethyl acetate=3 to 5:5 to 7. The inventor finds that the solvent has good compatibility with the material system, can contain polyurethane with higher hard segment content, promotes the dissolution of the single-component polyurethane primer, avoids the agglomeration or caking of the single-component polyurethane primer in the storage process, and thus improves the storage stability of the single-component polyurethane primer.

Preferably, the catalyst comprises an organobismuth catalyst.

Preferably, the organobismuth catalyst is bismuth carboxylate.

Alternatively, the organobismuth catalyst is selected from bismuth carboxylate catalysts manufactured by King Industries, U.S. under the designation K-KAT 348.

Preferably, the preparation method of the one-component polyurethane primer comprises the following operations: weighing raw materials for preparing the single-component polyurethane primer according to the amount, wherein the auxiliary agent comprises a hydroxyl chain extender; pre-polymerizing alcohol materials and isocyanate materials at 70-80 ℃ to obtain polyurethane prepolymer; adding hydroxyl chain extender into polyurethane prepolymer, maintaining the reaction temperature at 70-80 deg.c until the isocyanate value in the reaction system is less than or equal to 0.1%. The inventor prepares NCO end-capped polyurethane prepolymer through prepolymerization, and then reacts the polyurethane prepolymer with hydroxyl chain extender to prepare hydroxyl end-capped polyurethane. The preparation method not only increases the hard segment content of the single-component polyurethane primer, but also effectively avoids the defects of water foaming and poor storage stability of NCO-terminated polyurethane. In summary, the single-component polyurethane primer is prepared by the above operation steps, so that the formed primer layer has the advantages of high surface tension, stable structure and quick surface drying.

According to another aspect of the present invention, there is provided an adhesive tape comprising a base material layer, a primer layer, and an adhesive layer disposed in this order, the primer layer being made of the above one-component polyurethane primer. The adhesive tape provided by the scheme has stable structure and is not easy to be left. The primer layer in the adhesive tape provides an adhesion surface with higher surface tension for the substrate layer to be attached by the adhesive layer, so that the adhesive tape structure is stable. When the adhesive layer is attached to the surface of an object and torn off, the stripping force between the adhesive layer and the primer layer is larger than that between the adhesive layer and most of the objects, so that the structural stability of the adhesive tape is improved, and the adhesive tape is not easy to leave residual adhesive on the surface of the object.

Preferably, the substrate layer comprises polyethylene terephthalate. The inventors found that when polyethylene terephthalate (PET) is selected as the substrate layer, the adhesion between the primer layer and the substrate layer is higher, and can provide a higher surface tension for the PET substrate layer.

Preferably, the adhesive layer is made of at least one of TP-913 pressure-sensitive adhesive manufactured by Taiwan Nanbao resin company, an Zuo chemical Y-1410, and Guangdong bonding chemical PSA-1330 pressure-sensitive adhesive.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described 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 present invention without making any inventive effort, shall fall within the scope of the present invention.

Example 1

(1) Preparation of one-component polyurethane primer

The preparation raw materials of the single-component polyurethane primer comprise alcohol materials, isocyanate materials, auxiliary agents and solvents. The alcohol material consists of 14.8200 parts of polyester polyol, wherein the polyester polyol is polyethylene glycol butanediol adipate Polyol (PEBA), and the molecular weight of the polyester polyol is 1000. The isocyanate material consists of 8.980 parts of diisocyanate and 4.000 parts of polyisocyanate, wherein the diisocyanate is diphenyl Methane Diisocyanate (MDI), and the polyisocyanate is toluene diisocyanate-trimethylolpropane adduct (TDI-TMP adduct) with the brand name of L-75. The auxiliary agent is 0.0059 part of catalyst and 2.1700 parts of hydroxyl chain extender, wherein the catalyst is selected from bismuth carboxylate catalyst with the brand of K-KAT348 produced by King Industries in the United states, and the hydroxyl chain extender comprises 1.1000 parts of Ethylene Glycol (EG) and 1.0700 parts of 1, 4-Butanediol (BDO). The solvent included 30 parts N, N-Dimethylformamide (DMF) and 45 parts ethyl acetate.

The mass fraction of the materials can be calculated: the mass ratio of the alcohol material to the isocyanate material is 1.482:1.298. the mass ratio of diisocyanate to polyisocyanate is 8.980:4.000. the mass ratio of the hydroxyl chain extender to the isocyanate material is 0.217:1.298. the mass ratio of the N, N-dimethylformamide to the ethyl acetate is 4:6.

The single-component polyurethane primer is prepared by the following steps:

S1, adding an alcohol material, an isocyanate material, a hydroxyl chain extender glycol, a catalyst and 15 parts of solvent DMF into a reaction kettle, and stirring for 15min. Adding diisocyanate, polyisocyanate and 22.5 parts of solvent ethyl acetate into the reaction system, heating the reaction system to 75 ℃, and carrying out prepolymerization for continuous reaction for 2.5 hours to obtain polyurethane prepolymer;

S2, adding a hydroxyl chain extender 1, 4-butanediol and 22.5 parts of solvent ethyl acetate into the polyurethane prepolymer for multiple times, keeping the temperature of a reaction system at 70-80 ℃ and continuing to react for 2.5 hours;

S3, when the isocyanate value in the reaction system is less than or equal to 0.1%, no NCO residue exists in the reaction system, adding the rest 15 parts of solvent DMF into the reaction system, stirring for 15min, cooling and collecting materials, and obtaining the single-component polyurethane primer.

The prepared single-component polyurethane primer is detected, and the hard segment content is measured to be 50.59 percent and the solid content is measured to be 30 percent. According to the actual production and use requirements, the viscosity of the single-component polyurethane primer can be in the range of 100-300 mpa.s at 25 ℃. In other embodiments, the reaction time, NCO theoretical value and the batch feeding amount of the materials in S1, S2 and S3 can be regulated and controlled according to the production requirements, provided that the total batch feeding amount of the raw materials and the normal preparation of the primer are not affected.

(2) Preparation of adhesive tape

The adhesive tape comprises a substrate layer, a primer layer, an adhesive layer and a release film which are sequentially compounded. The primer layer is prepared from the single-component polyurethane primer provided in the step (1). The substrate layer is a polyethylene terephthalate (PET) film with the thickness of 50 μm, the adhesive layer is a high-viscosity acrylic pressure-sensitive adhesive with the trade name TP-913 produced by Taiwan Nanbao resin company, and the thickness of the release film is 25 μm.

The adhesive tape is prepared by the following steps:

The single-component polyurethane primer is diluted into a solution with the concentration of 25% by using ethyl acetate, then the diluted single-component polyurethane primer is coated on a substrate layer with the coating thickness of 0.5-1 g/square meter, and then the substrate layer is transferred to the environment of 120 ℃ and dried for 20-30 seconds to form a primer layer arranged on one side of the substrate layer, so as to prepare the intermediate of the adhesive layer.

Coating a high-viscosity acrylic pressure-sensitive adhesive on one side of the primer layer, which is away from the substrate layer, wherein the coating thickness is 20+/-1 mu m, transferring the primer layer to a 120 ℃ environment, and drying for 20-30 seconds to form a glue layer. And (3) attaching a release film to one side of the adhesive layer, which is opposite to the primer layer, so as to prepare the adhesive tape. The tape was transferred to an environment of 50 ℃ and cured for 24 hours.

Example 2

(1) Preparation of one-component polyurethane primer

The preparation raw materials of the single-component polyurethane primer comprise alcohol materials, isocyanate materials, auxiliary agents and solvents. The alcohol material consists of 16.4200 parts of polyester polyol, wherein the polyester polyol is polyethylene glycol diethylene glycol Polyol (PEDA) with the molecular weight of 2000. The isocyanate material consists of 7.5700 parts of diisocyanate and 1.6600 parts of polyisocyanate, wherein the diisocyanate is Toluene Diisocyanate (TDI), and the polyisocyanate is polymethylene polyphenyl isocyanate (PAPI). 0.0049 parts of catalyst and 4.3300 parts of hydroxyl chain extender in the auxiliary agent, wherein the catalyst is selected from bismuth carboxylate catalyst with the brand of K-KAT348 produced by King Industries in the United states, and the hydroxyl chain extender comprises 1.4800 parts of 1, 4-Butanediol (BDO) and 2.8500 parts of neopentyl glycol (NPG). The solvent included 24.5 parts N, N-Dimethylformamide (DMF) and 45.5 parts ethyl acetate.

The mass fraction of the materials can be calculated: the mass ratio of the alcohol material to the isocyanate material is 1.642:0.923. the mass ratio of diisocyanate to polyisocyanate is 8.980:4.000. the mass ratio of the hydroxyl chain extender to the isocyanate material is 0.433:0.923. the mass ratio of the N, N-dimethylformamide to the ethyl acetate is 3.5:6.5.

The procedure for the preparation of this one-component polyurethane primer was as described in example 1, with the difference that the hydroxyl-type chain extender BDO was added in S1 and the hydroxyl-type chain extender NPG in S2.

The prepared single-component polyurethane primer is detected, and the hard segment content is 45.25% and the solid content is 30%. According to the actual production and use requirements, the viscosity of the single-component polyurethane primer can be in the range of 100-300 mpa.s at 25 ℃. In other embodiments, the reaction time, NCO theoretical value and the batch feeding amount of the materials in S1, S2 and S3 can be regulated and controlled according to the production requirements, provided that the total batch feeding amount of the raw materials and the normal preparation of the primer are not affected.

(2) Preparation of adhesive tape

This procedure and the raw material composition were exactly the same as in example 1.

Example 3

(1) Preparation of one-component polyurethane primer

The preparation raw materials of the single-component polyurethane primer comprise alcohol materials, isocyanate materials, auxiliary agents and solvents. The alcohol material consists of 13.0800 parts of polyester polyol, wherein 7.8500 parts of poly (adipic acid) -3 methyl-1, 5-pentanediol Polyol (PMA) and 5.2300 parts of poly (ethylene glycol butylene glycol adipate) Polyol (PEBA) are selected as the polyester polyol, the molecular weight of the PMA is 2000, and the molecular weight of the PEBA is 1000. The isocyanate material comprises 11.49 parts of diisocyanate and 1.7500 parts of polyisocyanate, wherein the diisocyanate is selected from diphenylmethane diisocyanate (MDI), and the polyisocyanate is selected from polymethylene polyphenyl isocyanate (PAPI). 0.00523 parts of catalyst and 3.6600 parts of hydroxyl chain extender in the auxiliary agent, wherein the catalyst is bismuth carboxylate catalyst with the brand of K-KAT348 produced by King Industries in the United states, and the hydroxyl chain extender comprises 1.3000 parts of Ethylene Glycol (EG) and 2.3600 parts of 1, 4-Butanediol (BDO). The solvent included 24.5 parts N, N-Dimethylformamide (DMF) and 45.5 parts ethyl acetate.

The mass fraction of the materials can be calculated: the mass ratio of the alcohol materials to the isocyanate materials is 1.308:1.497. the mass ratio of diisocyanate to polyisocyanate is 11.4900:1.7500. the mass ratio of the hydroxyl chain extender to the isocyanate material is 0.366:1.497. the mass ratio of the N, N-dimethylformamide to the ethyl acetate is 4.5:5.5.

The procedure for the preparation of the one-component polyurethane primer was exactly as in example 1.

The prepared single-component polyurethane primer is detected, and the hard segment content is 56.38 percent and the solid content is 30 percent. According to the actual production and use requirements, the viscosity of the single-component polyurethane primer can be in the range of 100-300 mpa.s at 25 ℃. In other embodiments, the reaction time, NCO theoretical value and the batch feeding amount of the materials in S1, S2 and S3 can be regulated and controlled according to the production requirements, provided that the total batch feeding amount of the raw materials and the normal preparation of the primer are not affected.

(2) Preparation of adhesive tape

This procedure and the raw material composition were exactly the same as in example 1.

Example 4

This example was prepared with reference to the preparation method provided in example 1, and this example differs from example 1 in that: in the process of preparing the single-component polyurethane primer, on the premise of keeping the feeding amount of isocyanate materials unchanged, the mass ratio of diisocyanate to polyisocyanate is 10:1. the proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Example 5

This example was prepared with reference to the preparation method provided in example 1, and this example differs from example 1 in that: in the process of preparing the single-component polyurethane primer, the feeding amount of isocyanate materials is adjusted to ensure that the mass ratio of the alcohol materials to the isocyanate materials is 1.5:1. the proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Example 6

This example was prepared with reference to the preparation method provided in example 1, and this example differs from example 1 in that: in the preparation of the one-component polyurethane primer, the polyester polyol of example 1 was replaced with an equal mass of polyester polyol having a molecular weight of 1500. The proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Example 7

This example was prepared with reference to the preparation method provided in example 1, and this example differs from example 1 in that: in the process of preparing the single-component polyurethane primer, the following steps replace the step-by-step preparation operation of S1 and S2: and uniformly stirring the alcohol materials, the isocyanate materials, all the auxiliary agents and part of the solvent, heating the reaction system to 75 ℃, and continuously stirring and reacting for 5 hours. The proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Comparative example 1

This comparative example was prepared with reference to the preparation method provided in example 1, and this comparative example differs from example 1 in that: in the preparation of the one-component polyurethane primer, the polyisocyanates of example 1 are replaced by diisocyanates of equal mass. The proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Comparative example 2

This comparative example was prepared with reference to the preparation method provided in example 1, and this comparative example differs from example 1 in that: in the preparation of the one-component polyurethane primer, the polyisocyanates of example 1 were replaced by HDI biuret of equal mass, while the diisocyanates of example 1 were replaced by isophorone diisocyanate of equal mass. The proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Comparative example 3

This comparative example was prepared with reference to the preparation method provided in example 1, and this comparative example differs from example 1 in that: in the process of preparing the single-component polyurethane primer, the feeding amount of isocyanate materials is adjusted to ensure that the mass ratio of the alcohol materials to the isocyanate materials is 1:2. the proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Comparative example 4

This comparative example was prepared with reference to the preparation method provided in example 1, and this comparative example differs from example 1 in that: in the process of preparing the single-component polyurethane primer, the feeding amount of isocyanate materials is adjusted to ensure that the mass ratio of the alcohol materials to the isocyanate materials is 2:0.5. the proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Comparative example 5

This comparative example was prepared with reference to the preparation method provided in example 1, and this comparative example differs from example 1 in that: in the process of preparing the adhesive tape, the coating of the single-component polyurethane primer is omitted, and the high-viscosity acrylic pressure-sensitive adhesive is directly coated on the substrate layer. The proportions of the other raw materials and the preparation method are strictly consistent with those of the example 1.

Test example 1

1. Performance test of single-component polyurethane primer

A reference subject: examples 1 to 7 and comparative examples 1 to 5 provide intermediate gum layers. The intermediate of the adhesive layer comprises a substrate layer and a primer layer which are sequentially compounded, wherein the primer layer is prepared from the single-component polyurethane primer provided in examples 1-7 and the primer provided in comparative examples 1-5 respectively.

Test items and test methods:

(1) Surface dryness test: cutting the test object into 50mm and placing the test object on a horizontal tabletop, using a PET raw film 25mm 50um to bond the test object, and if the PET raw film can generate adhesiveness with the test object, indicating that the coating has no surface dryness, so that the next test is not performed.

(2) Corona value test: firstly, cleaning the surface of a test object, spreading the test object on a horizontal table, lightly scratching the surface of the primer layer of the test object with a corona pen, and if the liquid does not shrink within three seconds, reaching the selected dyne value of the corona pen, otherwise, not reaching the selected dyne value. In this test, a base material layer was set as a blank group, and the surface dyne value of the blank group was recorded.

(3) Back tack test: cutting the size of the test object to 100mm and 100mm, compounding the test object with 50umPET original film, pressing the test object with 1kg of pressing block, placing the test object in an oven at 40 ℃ for 24 hours, cooling the test object to room temperature, testing the stripping force between the primer layer and the original film in the test object, and if the stripping force is 0, performing the next test, if the stripping force is tested, indicating that the primer has poor temperature resistance, can be back-adhered in an actual rolled sample, has no practical application value, and does not need the next test

(4) Adhesion test: according to GB/T9286-1998, a coating is coated on a 50umPET original film, the thickness of the coating is controlled to be 3-5um, 100 small squares are scraped by a hundred grid knife with a 1mm interval, an M600 or 610 adhesive tape is adhered to the hundred grids, a 3M adhesive tape is quickly pulled up, the falling number is tested, the falling number is less than or equal to 5 percent (namely, the level is more than 4B), and the next test is judged to be qualified.

2. Performance test of adhesive tape

A reference subject: the adhesive tapes provided in examples 1 to 7 and comparative examples 1 to 5.

Test items and test methods:

(1) 180 ° peel force test: according to the test method in test method of peel strength of adhesive tape of GB/T2792-2014, a test object is cut into a size of 24mm by 150mm, the test object is spread on glass, and the glass is rolled back and forth three times by a rubber roller of 1kg and placed for 20min at room temperature. Then, the test piece was peeled off from the glass at a peeling rate of 300mm/min, and a peeling force test was performed to record whether or not there was a residual adhesive on the glass.

Test results: the test results are shown in Table 1.

TABLE 1 Performance test results of one-component polyurethane primer and adhesive tape

Analysis of results:

Comparing the test indexes of examples 1 to 7 with those of comparative examples 1 to 5 in Table 1, it can be found that the single-component polyurethane primer provided in examples 1 to 7 can raise the corona value of the substrate layer, and has stable structure, good storage stability and good solvent resistance. Among them, in the actual production test process, the single-component polyurethane primer provided in comparative examples 1 to 3 has the obvious problem of poor storage stability, because the reaction R value in comparative examples 1 to 3 is too large, the formed polyurethane has poor reaction regularity, and the film is hard and brittle. Therefore, although the primer compositions of comparative examples 1 to 3 can raise the surface corona value of the substrate layer in a short time, the structural stability is poor and it is impossible to provide a high corona value for a long period of time.

Comparing the properties of examples 1 to 7 in Table 1 with those of comparative example 4, it was found that the primer of comparative example 4 was less likely to be dry, since the R value of the reaction in comparative example 4 was too small, corresponding to an excess of-OH, and was less likely to be dry.

Comparing the performances of examples 1 to 7 with those of comparative example 5, it can be found that the pretreatment means of the one-component polyurethane primer adopted in examples 1 to 7 not only improves the surface dyne value of the substrate layer, but also improves the structural stability of the adhesive tape. Therefore, the single-component polyurethane primer has good solvent resistance and structural stability on the premise of improving the surface tension of the substrate layer.

The above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention.

Claims (10)

1. The single-component polyurethane primer is characterized by comprising the following raw materials:

The alcohol material comprises polyester polyol, wherein the polyester polyol comprises at least one of polyethylene glycol adipate butanediol polyol, polyethylene glycol adipate diethylene glycol polyol and poly (3-methyl-1, 5-pentanediol adipate) polyol;

the isocyanate material comprises diisocyanate and polyisocyanate, wherein the molecular structure of the diisocyanate and/or the polyisocyanate comprises aromatic rings, and the diisocyanate is calculated according to the mass ratio: the polyisocyanate=6 to 12:1 to 5;

An auxiliary agent, wherein the auxiliary agent comprises a catalyst;

A solvent;

and the alcohol materials are calculated according to the mass ratio: the isocyanate material=1 to 2:0.7 to 1.7.

2. The single-component polyurethane primer of claim 1, wherein the auxiliary agent comprises a hydroxyl-type chain extender, and the molecular structure of the hydroxyl-type chain extender at least comprises 2 hydroxyl groups; the hydroxyl chain extender comprises the following components in percentage by mass: the isocyanate material=0.2 to 0.5:0.7 to 1.7.

3. The one-component polyurethane primer of claim 2, wherein the hydroxyl-type chain extender comprises at least one of ethylene glycol, 1, 4-butanediol, diethylene glycol, neopentyl glycol.

4. The one-component polyurethane primer of claim 1, wherein the polyester polyol has a molecular weight of 1000 to 2000.

5. The one-component polyurethane primer of claim 1, wherein the diisocyanate comprises at least one of toluene diisocyanate and diphenylmethane diisocyanate.

6. The one-component polyurethane primer of claim 5, wherein the polyisocyanate comprises at least one of toluene diisocyanate-trimethylolpropane adduct, polymethylene polyphenyl isocyanate.

7. The one-component polyurethane primer of claim 1, wherein the solvent comprises N, N-dimethylformamide and ethyl acetate, and wherein the N, N-dimethylformamide is calculated as a mass ratio: ethyl acetate=3 to 5:5 to 7.

8. A one-component polyurethane primer as claimed in any one of claims 1 to 7, characterized in that the preparation method comprises the following operations:

weighing raw materials for preparing the single-component polyurethane primer according to the amount, wherein the auxiliary agent comprises a hydroxyl chain extender;

Pre-polymerizing the alcohol material and the isocyanate material at the temperature of 70-80 ℃ to obtain polyurethane prepolymer;

and adding the hydroxyl chain extender into the polyurethane prepolymer, and keeping the reaction temperature at 70-80 ℃ until the isocyanate value in the reaction system is less than or equal to 0.1%.

9. An adhesive tape, characterized in that the adhesive tape comprises a substrate layer, a primer layer and an adhesive layer which are sequentially arranged, wherein the primer layer is prepared from the single-component polyurethane primer according to any one of claims 1 to 8.

10. The tape of claim 9 wherein the substrate layer comprises polyethylene terephthalate.