CN116199829A - A kind of polymer emulsion viscosifier and its preparation method and application - Google Patents

Abstract

The invention provides a polymer emulsion tackifier, a preparation method and application thereof. The preparation raw materials of the polymer emulsion tackifier comprise a first acrylic ester monomer, a second acrylic ester monomer, a third acrylic ester monomer, a fourth acrylic ester monomer, an initiator and an emulsifier; the second acrylic monomer comprises an isocyanate modified acrylic monomer. According to the invention, the polymer emulsion tackifier is prepared from the raw materials of the isocyanate modified acrylic ester monomers, and the acrylic ester monomers are mutually matched, so that the obtained polymer emulsion tackifier has good compatibility with the acrylic acid adhesive, the peel strength and wettability of the adhesive and a base material are improved, and the application range is wide.

Description

A kind of polymer emulsion viscosifier and its preparation method and application

technical field

The invention belongs to the technical field of tackifiers, in particular to a polymer emulsion tackifier and its preparation method and application.

Background technique

Water-based acrylate emulsion adhesive has the advantages of non-toxicity, simple synthesis process, low production cost, strong product bonding adaptability, fast drying film forming rate, environmental protection and no pollution, so it occupies a pivotal position in the adhesive industry, especially in Pressure-sensitive adhesives, paper/plastic laminating adhesives, floor adhesives and automotive interior adhesives are widely used. However, due to the characteristics of the straight-chain molecular structure of polyacrylate emulsion, it has certain defects in bonding performance and wettability with different substrates.

In the prior art, in order to broaden and improve the application properties and fields of acrylic emulsion adhesives, the initial adhesion, holding force and peel strength of the adhesive are usually improved by adding water-based thickening emulsions, among which the most widely used are rosin series resins, Terpene resin, etc., and the tackifier is mostly added to the water-based acrylate emulsion in the form of physical blending, generally accounting for 15-20%. For example, CN108084937A discloses an epoxy acrylic adhesive, which includes a tackifier water-based tackifying rosin resin or multi-carbon tackifying resin. And CN102701982A discloses a kind of method that utilizes terpineol by-product terpinene to synthesize tackifier monomer, utilizes turpentine oil to produce terpineol by-product terpinene, through addition and esterification reaction, synthesizes a kind of tackifier, It can be used in acrylic water-based paints or adhesives, as a tackifier monomer or as a tackifier monomer for hot melt adhesives, and has good application value. However, the tackifier has poor compatibility with acrylic acid, and the bonding strength of the obtained acrylic adhesive needs to be further improved.

The general defects in the prior art are that the bonding strength of rosin series resin and terpene resin tackifier is not high, and the compatibility with acrylate emulsion is not good, which easily causes the phase separation problem after the adhesive film is formed, resulting in the film The uniformity of the layer decreases, the adhesive effect is not good, the performance is unstable, and it cannot effectively meet the market requirements of the adhesive.

Therefore, it is a technical problem to be solved urgently in this field to develop a kind of water-based polymer emulsion tackifier that has good compatibility with acrylic adhesive, and is beneficial to improve the peel strength of acrylic adhesive and prolong the action time.

Contents of the invention

Aiming at the deficiencies in the prior art, the object of the present invention is to provide a polymer emulsion tackifier and its preparation method and application. The polymer emulsion tackifier uses isocyanate-modified acrylate monomers as raw materials, and cooperates with a variety of acrylate monomers to make the obtained polymer emulsion tackifier compatible with acrylic adhesives. Good, and improve the peel strength and wetting performance of the adhesive and the substrate. With a small dosage, the adhesive can have high initial adhesion, peel strength and long sticking time, and has a wide range of applications.

For reaching this purpose, the present invention adopts following technical scheme:

In the first aspect, the present invention provides a polymer emulsion tackifier, the preparation raw materials of the polymer emulsion tackifier include a first acrylate monomer, a second acrylate monomer, a third acrylate monomer body, a fourth acrylate monomer, an initiator and an emulsifier; the second acrylate monomer includes an isocyanate-modified acrylate monomer.

In the present invention, by using isocyanate to modify acrylate monomers, acrylate monomers with polyurethane characteristics are obtained, so that the polymer emulsion has the characteristics of high adhesion, high peel strength and excellent temperature stability of polyurethane ; and through the mutual cooperation of various acrylate monomers, the obtained polymer emulsion tackifier not only has good compatibility with acrylic adhesives, but also avoids phase separation; and can improve the adhesion of the adhesive to the substrate Wetting and bonding properties, a good alternative to natural emulsion tackifiers.

Preferably, the isocyanate-modified acrylate monomer has a comb structure.

Preferably, the raw materials for preparing the isocyanate-modified acrylate monomer include hydroxyl-containing acrylate monomer, isocyanate and polymer polyol.

Preferably, the molar ratio of the hydroxyl-containing acrylate monomer, isocyanate and polymer polyol is 1:(1-1.1):(1.1-1.2), wherein the specific values in (1-1.1) are such as It can be 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, etc.; the specific values in (1.1～1.2) can be, for example, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19 etc.

Preferably, the hydroxyl-containing acrylate monomer includes at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate or hydroxypropyl methacrylate, more preferably hydroxyethyl acrylate and /or Hydroxypropyl Acrylate.

Preferably, the isocyanate comprises a diisocyanate.

Preferably, the isocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate, more preferably hexamethylene diisocyanate diisocyanate and/or isophorone diisocyanate.

Preferably, the number average molecular weight of the polymer polyol is 200-600, such as 220, 250, 280, 300, 320, 350, 380, 400, 420, 450, 480, 500, 520, 550, 580 wait.

Preferably, the polymer polyol comprises polyether polyol.

Preferably, the polyether polyol comprises polyethylene glycol and/or polypropylene glycol.

Preferably, the isocyanate-modified acrylate monomer is prepared by the following method, which includes:

(i) react isocyanate with hydroxyl-containing acrylate monomer to obtain reactant 1;

(ii) reacting the reactant 1 obtained in the step (i) with a polymer polyol to obtain the isocyanate-modified acrylate monomer.

Preferably, the reaction in step (i) is carried out in the presence of a protective atmosphere.

In the present invention, the protective atmosphere includes but not limited to nitrogen.

Preferably, the reaction system in step (i) further includes a catalyst and a polymerization inhibitor.

Preferably, the content of the catalyst is 0.05-0.3% of the mass of isocyanate, such as 0.1%, 0.15%, 0.2%, 0.25% and so on.

Preferably, the catalyst comprises an organometallic catalyst.

Preferably, the organometallic catalyst includes at least one of stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dibutyrate or dioctyltin dilaurate.

Preferably, the content of the polymerization inhibitor is 0.05-0.15% of the mass of the hydroxyl-containing acrylate monomer, such as 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.12%, 0.14%, etc.

Preferably, the polymerization inhibitor includes at least one of hydroquinone, p-benzoquinone, p-hydroxyanisole or tert-butylhydroquinone.

Preferably, the reaction temperature in step (i) is 30-60°C, for example, 35°C, 40°C, 45°C, 50°C, 55°C, etc.

Preferably, the reaction time in step (i) is 1-3 hours, for example, 1.5 hours, 2 hours, 2.5 hours, etc.

Preferably, the reaction temperature in step (ii) is 60-80°C, for example, 65°C, 70°C, 75°C, etc.

Preferably, the reaction time in step (ii) is 1-2 hours, for example, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, etc.

Preferably, the first acrylate monomer includes C2-C15 alkyl acrylate, where C2-C15 can be, for example, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14 etc.

Preferably, the first acrylate monomer includes at least one of ethyl acrylate, butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate or laurate acrylate, preferably butyl acrylate.

Preferably, the third acrylate monomer includes acrylate monomers containing hydroxyl and/or amino groups.

Preferably, the third acrylate monomer includes hydroxyethyl acrylate and/or hydroxypropyl acrylate.

Preferably, the fourth acrylate monomer includes a carboxyl group-containing acrylate monomer.

Preferably, the carboxyl-containing acrylate monomer includes β-acryloxypropionic acid and/or β-methacryloxypropionic acid, preferably β-acryloxypropionic acid.

Preferably, the mass ratio of the first acrylate monomer, the second acrylate monomer, the third acrylate monomer, and the fourth acrylate monomer is 100:(30-50):(5 ～10): (10～20), wherein the specific values in (30～50) can be, for example, 32, 34, 36, 38, 40, 42, 44, 46, 48, etc.; in (5～10) The specific values can be, for example, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, etc.; the specific values in (10-20) can be, for example, 11, 12, 13, 14, 15, 16, 17, 18, 19, etc.

In the present invention, by selecting the second acrylate monomer, the third acrylate monomer, and the fourth acrylate monomer containing functional groups, the side chain of the polymer emulsion tackifier contains carbamate, ring Oxygen, ester group, hydroxyl group, amino group, carboxyl group and other functional groups can greatly improve the wetting and bonding ability of the emulsion to the adhesive substrate, and promote the interaction between the adhesive emulsion and the substrate, thus significantly improving the adhesion of the adhesive. Excellent adhesion and peel strength, a good substitute for natural emulsion tackifiers.

Preferably, the amount of the initiator is 0.1-1% of the total mass of the monomers, such as 0.2%, 0.4%, 0.6%, 0.8%, etc.

Preferably, the initiator includes at least one of a peroxide initiator, an azo initiator or a redox initiator.

Preferably, the initiator includes at least one of potassium persulfate, ammonium persulfate, potassium persulfate-sodium sulfite, hydrogen peroxide or azobisisobutylamidine hydrochloride, preferably potassium persulfate and/or persulfate ammonium sulfate.

Preferably, the content of the emulsifier is 0.2-1% of the total mass of the monomers, such as 0.4%, 0.6%, 0.8%, etc.

Preferably, the emulsifiers include anionic emulsifiers and/or nonionic emulsifiers.

Preferably, the emulsifier includes at least one of alkylphenol polyoxyethylene ether, alkylphenol polyoxyethylene ether ammonium sulfate, ethoxylated alkylsulfate sodium salt or polyoxyethylene ether castor oil ester.

Preferably, the raw materials for the preparation of the polymer emulsion tackifier further include a chain transfer agent.

Preferably, the amount of the chain transfer agent is 0.5-3% of the total mass of the monomers, for example, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, etc.

Preferably, the chain transfer agent comprises a mercapto compound.

Preferably, the chain transfer agent includes at least one of butylmercaptan, tert-butylmercaptan, dodecylmercaptan, mercaptoethanol or mercaptopropionic acid, more preferably mercaptoethanol and/or mercaptopropionic acid.

In a second aspect, the present invention provides a method for preparing the polymer tackifier according to the first aspect, the preparation method comprising:

(1) Mix the first acrylate monomer, the second acrylate monomer, the third acrylate monomer, the fourth acrylate monomer, an emulsifier and a solvent, and perform pre-emulsification to obtain a monomer pre-emulsification Lotion;

(2) 10～30% (such as can be 10%, 15%, 20%, 25%, 30% etc.) It can be 35%, 40%, 45%, etc.) initiator mixing, polymerization reaction, to obtain seed emulsion;

(3) Mix the seed emulsion obtained in step (2) with the remaining monomer pre-emulsion and the remaining initiator, and react to obtain the polymer emulsion tackifier.

Preferably, the mixed raw materials in step (1) further include a chain transfer agent.

Preferably, the pre-emulsification method in step (1) includes shear emulsification.

Preferably, the shearing speed is 300-800r/min, such as 350r/min, 400r/min, 450r/min, 500r/min, 550r/min, 600r/min, 650r/min, 700r/min , 750r/min, etc.

Preferably, the temperature of the polymerization reaction in step (2) is 50-80°C, such as 55°C, 60°C, 65°C, 70°C, 75°C, etc.

Preferably, the polymerization reaction time in step (2) is 1-3 hours, for example, 1.5 hours, 2 hours, 2.5 hours, etc.

Preferably, the mixing in step (3) includes adding the remaining monomer pre-emulsion and the remaining initiator dropwise into the seed emulsion in sequence.

Preferably, the dropping time of the remaining monomer pre-emulsion is 3-5 hours, for example, it may be 3.5 hours, 4 hours, 4.5 hours and so on.

Preferably, the dropping time of the remaining initiator is 4-6 hours, for example, it may be 4.5 hours, 5 hours, 5.5 hours and so on.

Preferably, the reaction temperature in step (3) is 55-95°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, etc.

Preferably, the reaction time in step (3) is 2 to 5 hours, for example, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, etc.

Preferably, the solid content of the polymer emulsion tackifier is 40-60%, for example, it may be 45%, 50%, 55% and so on.

In a third aspect, the present invention provides an acrylic adhesive, which includes an acrylic masterbatch emulsion and the polymer emulsion tackifier described in the first aspect.

Preferably, the effective mass percentage of the polymer emulsion tackifier in the acrylic adhesive is 2-6%, for example, it can be 2.5%, 3%, 3.5%, 4%, 4.5%, 5% , 5.5%, etc.

In the present invention, the effective mass percentage refers to the mass content except the solvent.

The numerical ranges described in the present invention not only include the above-listed point values, but also include any point values between the above-mentioned numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention will not exhaustively list the ranges. The specific pip value to include.

Compared with prior art, the beneficial effect of the present invention is:

The polymer tackifier emulsion provided by the present invention uses isocyanate-modified acrylate monomers as raw materials, and through the mutual coordination of various acrylate monomers, the obtained polymer emulsion tackifier is compatible with the acrylic adhesive. Good capacity, avoiding phase separation; and improves the wetting and bonding ability of the emulsion to the adhesive substrate, promotes the interaction between the adhesive emulsion and the substrate, thereby significantly improving the adhesive force and peel strength of the adhesive , to achieve a good replacement for natural emulsion tackifiers.

Detailed ways

The technical solutions of the present invention will be further described below through specific embodiments. It should be clear to those skilled in the art that the examples are only for helping to understand the present invention, and should not be regarded as specific limitations on the present invention.

Preparation Example 1

A kind of isocyanate modified acrylate monomer, the preparation raw material of described isocyanate modified acrylate monomer comprises 176.4g hexamethylene diisocyanate, 116g hydroxyethyl acrylate, 220g polyethylene glycol 200, 0.088g octanoic acid stannous and 0.058g hydroquinone.

The preparation method of described isocyanate modified acrylate monomer comprises:

Under nitrogen atmosphere, weigh hexamethylene diisocyanate and stannous octoate in a flask, heat up to 30°C, add hydroquinone-containing hydroxyethyl acrylate monomer dropwise, react for 3 hours, add polyethylene glycol 200, carry out end-capping treatment at 70°C, and continue the reaction for 2 hours to obtain the isocyanate-modified acrylate monomer.

Preparation example 2

A kind of isocyanate modified acrylate monomer, the preparation raw material of described isocyanate modified acrylate monomer comprises 244.5g isophorone diisocyanate, 130g hydroxypropyl acrylate, 720g polyethylene glycol 600, 0.48g diisocyanate dibutyltin laurate and 0.13 g hydroquinone.

The preparation method of described isocyanate modified acrylate monomer comprises:

Under nitrogen atmosphere, weigh isophorone diisocyanate and dibutyltin dilaurate in a flask, heat up to 50°C, add hydroquinone-containing hydroxypropyl acrylate monomer dropwise, react for 2 hours, add polyethylene Diol 600 was subjected to end-capping treatment at 60° C., and the reaction was continued for 2 hours to obtain the isocyanate-modified acrylate monomer.

Preparation example 3

A kind of isocyanate modified acrylate monomer, the preparation raw material of described isocyanate modified acrylate monomer comprises 201g xylylene diisocyanate, 130g hydroxyethyl methacrylate, 460g polypropylene glycol 400, 0.6g di Dibutyltin acetate and 0.195g hydroquinone.

The preparation method of described isocyanate modified acrylate monomer comprises:

Under nitrogen atmosphere, weigh xylylene diisocyanate and dibutyltin diacetate in a flask, heat up to 60°C, add hydroquinone-containing hydroxyethyl methacrylate monomer dropwise, react for 1 hour, add Polypropylene glycol 400 was subjected to end-capping treatment at 80° C., and the reaction was continued for 1 hour to obtain the isocyanate-modified acrylate monomer.

Preparation Example 4

An isocyanate-modified acrylate monomer, the only difference between it and Preparation Example 1 is that the polyethylene glycol 200 is replaced by ethylene glycol with an equivalent hydroxyl molar mass, and other raw materials, dosages and preparation methods are the same as those in Preparation Example 1. Example 1 is the same.

Preparation Example 5

An isocyanate-modified acrylate monomer, the only difference between it and Preparation Example 1 is that the polyethylene glycol 200 is replaced by polyethylene glycol 800 with an equivalent hydroxyl molar mass, and other raw materials, dosages and preparation methods are the same. Same as Preparation Example 1.

Preparation example 6

An isocyanate-modified acrylate monomer, the only difference from Preparation Example 1 is that the polyethylene glycol 200 is replaced by pentaerythritol with an equivalent hydroxyl molar mass, and other raw materials, dosages and preparation methods are the same as those in Preparation Example 1. same.

Preparation Example 7

An isocyanate-modified acrylate monomer, the only difference from Preparation Example 1 is that the polyethylene glycol 200 is replaced by pentaerythritol with an equivalent hydroxyl molar mass, and the preparation method comprises: under a nitrogen environment, weigh Put isophorone diisocyanate and dibutyltin dilaurate in a flask, add pentaerythritol, react at 60°C for 2 hours, add dropwise hydroxypropyl acrylate monomer containing hydroquinone, react at 50°C After 2 hours, the isocyanate-modified acrylate monomer was obtained.

Example 1

This embodiment provides a polymer emulsion tackifier, the preparation raw materials of the polymer emulsion tackifier include 100g butyl acrylate, 50g isocyanate modified acrylate monomer (preparation example 1), 5g hydroxyethyl acrylate , 15g β-acryloxypropionic acid, 2.55g mercaptopropionic acid, 0.85g alkylphenol ethoxylate and 0.17g potassium persulfate.

The present embodiment provides a kind of preparation method of described polymer emulsion tackifier, specifically comprises:

(1) Mix 100g butyl acrylate, 50g isocyanate-modified acrylate monomer, 5g hydroxyethyl acrylate, 15g β-acryloxypropionic acid, 2.55g mercaptopropionic acid, 0.85g alkylphenol polyoxyethylene ether with 252g of pure water was mixed, sheared and emulsified to obtain monomer pre-emulsion;

(2) Add 128g of the monomer pre-emulsion obtained in step (1) and 0.085g of potassium persulfate into the flask, heat up to 50°C to initiate polymerization, and react for 3 hours to obtain a blue-white seed emulsion;

(3) drip remaining monomer pre-emulsion and potassium persulfate solution (0.085g potassium persulfate is dissolved in 10g water) in the blue-white seed emulsion that step (2) obtains, the monomer pre-emulsion adding time is 3 hours, The potassium persulfate solution is added dropwise for 4 hours; after the dropwise addition is completed, the reaction is continued at 65°C for 4 hours, and part of the water is removed under reduced pressure to obtain a blue light emulsion with a solid content of 50.6%, which is to increase the viscosity of the polymer emulsion agent.

Example 2

This embodiment provides a polymer emulsion tackifier, the preparation raw materials of the polymer emulsion tackifier include 100g 2-ethylhexyl acrylate, 40g isocyanate-modified acrylate monomer (preparation example 2), 10g Hydroxypropyl acrylate, 10 g beta-methacryloxypropionic acid, 0.8 g mercaptoethanol, 0.32 g ammonium alkylphenol ethoxylate sulfate and 0.3 g ammonium persulfate.

The present embodiment provides a kind of preparation method of described polymer emulsion tackifier, specifically comprises:

(1) Mix 100g of 2-ethylhexyl acrylate, 40g of isocyanate-modified acrylate monomer, 10g of hydroxypropyl acrylate, 10g of β-methacryloxypropionic acid, 0.8g of mercaptoethanol, and 0.32g of alkylphenol Polyoxyethylene ether ammonium sulfate was mixed with 68g of pure water, and sheared and emulsified to obtain monomer pre-emulsion;

(2) Add 22.9 g of the monomer pre-emulsion obtained in step (1) and 0.12 g of ammonium persulfate into the flask, heat up to 70° C. to initiate polymerization, and react for 2 hours to obtain a blue-white seed emulsion;

(3) drip remaining monomer pre-emulsion and ammonium persulfate solution (0.18g ammonium persulfate is dissolved in 90g water) in the blue-white seed emulsion that step (2) obtains, and the time of adding is 5 hours; Afterwards, the reaction was continued at 80° C. for 5 hours to obtain a blue light emulsion with a solid content of 50.3%, which was the polymer emulsion tackifier.

Example 3

This embodiment provides a polymer emulsion tackifier, the preparation raw materials of the polymer emulsion tackifier include 100g isooctyl acrylate, 30g isocyanate modified acrylate monomer (preparation example 3), 8g hydroxyethyl acrylate ester, 20g beta-acryloyloxypropionic acid, 4.74g dodecyl mercaptan, 1.58g alkylphenol ethoxylates and 1.58g potassium persulfate.

The present embodiment provides a kind of preparation method of described polymer emulsion tackifier, specifically comprises:

(1) 100g of isooctyl acrylate, 30g of isocyanate-modified acrylate monomer, 8g of hydroxyethyl acrylate, 20g of β-acryloyloxypropionic acid, 4.74g of dodecyl mercaptan, 1.58g of alkylphenol Oxyethylene ether is mixed with 123g of pure water, and shear emulsified to obtain monomer pre-emulsion;

(2) Add 57.5 g of the monomer pre-emulsion obtained in step (1) and 0.48 g of potassium persulfate into the flask, heat up to 80° C. to initiate polymerization, and react for 1 hour to obtain a blue-white seed emulsion;

(3) drip remaining monomer pre-emulsion and potassium persulfate solution (1.1g potassium persulfate is dissolved in 29g water) in the blue-white seed emulsion that step (2) obtains, the monomer pre-emulsion adding time is 4 hours, The potassium persulfate solution was added dropwise for 6 hours; after the dropwise addition, the reaction was continued at 85° C. for 2 hours to obtain a blue light emulsion with a solid content of 50.5%, which was the polymer emulsion tackifier.

Example 4-7

Embodiment 4-7 provides a kind of polymer emulsion tackifier, and its difference with embodiment 1 is only, described isocyanate-modified acrylic ester type monomer is the isocyanate-modified acrylic acid that preparation example 4-7 provides Ester monomer, other raw materials, consumption and preparation method are all identical with embodiment 1.

Example 8

This embodiment provides a polymer emulsion tackifier, the only difference from Embodiment 1 is that the total amount of the monomers remains unchanged, the first acrylate monomer, the second acrylate monomer, the third The mass ratio of the acrylate monomer to the fourth acrylate monomer is 100:20:20:30, and the other raw materials, dosage and preparation method are the same as in Example 1.

Example 9

This embodiment provides a polymer emulsion tackifier, the only difference from Embodiment 1 is that the total amount of the monomers remains unchanged, the first acrylate monomer, the second acrylate monomer, the third The mass ratio of the acrylate monomer to the fourth acrylate monomer is 100:60:2:8, and the other raw materials, dosage and preparation method are the same as in Example 1.

Comparative example 1

This comparative example provides a polymer emulsion tackifier, the only difference from Example 1 is that the isocyanate-modified acrylate monomer is replaced by an equal mass of hydroxyethyl acrylate, other raw materials, dosage and preparation The methods are all the same as in Example 1.

Comparative example 2

This comparative example provides a polymer emulsion tackifier, which differs from Example 1 only in that the total amount of the isocyanate-modified acrylate monomer, hydroxyethyl acrylate and β-acryloxypropionic acid No change, no hydroxyethyl acrylate and β-acryloyloxypropionic acid, other raw materials, dosage and preparation method are the same as in Example 1.

Performance Testing

Using BASF Acronal AV 215ap as the acrylate masterbatch emulsion, adding the polymer emulsion tackifiers provided in Examples 1-9 and Comparative Examples 1-2 with different contents, the following tests were carried out; among them, American Lauter 780G water-based rosin was used for tackifying The emulsion is a comparative sample; where "-" means that no tackifier is added, only acrylate masterbatch emulsion;

(1) Initial adhesion: tested according to ASTM D3121-17 standard;

(2) 180°C peel strength: tested according to GB/T 25256 standard;

(3) Holding power: Tested according to GB/T 48514 standard.

The specific test results are shown in Table 1:

Table 1

As can be seen from the above table, the polymer emulsion tackifier provided by the present invention uses isocyanate-modified acrylate monomers as raw materials, and cooperates with various acrylate monomers to make the obtained polymer emulsion tackifier It has good compatibility with acrylic adhesive, and can improve the peeling strength and wetting performance between the adhesive and the substrate with a small dosage. The adhesive has a strong initial adhesion and a long sticking time; It can be seen that when the content of the polymer emulsion tackifier is between 5% and 10%, the initial tack of the adhesive can reach 8.9-10.48N, the peel strength at 180°C is 12.7-15.64N, and the holding force can reach 22.3～24.5h.

From Example 1 and Examples 4 to 7, it can be seen that under the same amount of the polymer emulsion tackifier, it is not the specific isocyanate-modified acrylate monomer of the present invention, the initial adhesion and peeling of the adhesive Intensity and holding power become poor; From Example 1 and Examples 8 and 9, it can be seen that under the same situation of the polymer emulsion tackifier consumption, the first acrylate monomer, the second acrylate monomer The mass ratio of the monomer, the third acrylate monomer, and the fourth acrylate monomer is not specific, and the initial adhesion, peel strength and holding force of the adhesive become worse.

From the comparison of Example 1 and the comparative example, it can be seen that under the same amount of the polymer emulsion tackifier, the performance of the adhesive is obviously changed without using isocyanate to modify the acrylic monomer or adding a functional group monomer. Difference.

By comparing the 1st group with the 14th group, it can be seen that the polymer emulsion tackifier provided by the present invention has only 5% tackifier content, and the effect of 15% of the water-based rosin tackifier emulsion dosage can be achieved, and is better than Water-based rosin tackifying emulsion.

In summary, the polymer emulsion tackifier provided by the present invention is modified by using isocyanate to modify acrylic monomers, and at the same time, by adding specific ratios of acrylic monomers containing various functional groups, the polymer Emulsion tackifier, compared with conventional water-based rosin emulsion, can obtain better adhesive performance with less addition, effectively overcomes the poor compatibility between natural tackifier emulsion and acrylic emulsion Ideal disadvantages, can effectively replace the existing varieties of viscosity-increasing emulsions, and achieve high-performance adhesive requirements. Therefore, the present invention has significant value for expanding the industrial application of the acrylic adhesive emulsion.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. The polymer emulsion tackifier is characterized in that the preparation raw materials of the polymer emulsion tackifier comprise a first acrylic monomer, a second acrylic monomer, a third acrylic monomer, a fourth acrylic monomer, an initiator and an emulsifier;

the second acrylic monomer comprises an isocyanate modified acrylic monomer.

2. The polymer emulsion tackifier according to claim 1, wherein the isocyanate modified acrylate monomer has a comb structure;

preferably, the preparation raw materials of the isocyanate modified acrylic monomer comprise hydroxyl-containing acrylic monomer, isocyanate and polymer polyol;

preferably, the mol ratio of the hydroxyl-containing acrylic monomer to the isocyanate to the polymer polyol is 1 (1-1.1): 1.1-1.2;

preferably, the hydroxyl-containing acrylate monomer comprises at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate or hydroxypropyl methacrylate, and further preferably hydroxyethyl acrylate and/or hydroxypropyl acrylate;

preferably, the isocyanate comprises a diisocyanate;

preferably, the isocyanate comprises at least one of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate, more preferably hexamethylene diisocyanate and/or isophorone diisocyanate;

preferably, the polymer polyol has a number average molecular weight of 200 to 600;

preferably, the polymer polyol comprises a polyether polyol;

preferably, the polyether polyol comprises polyethylene glycol and/or polypropylene glycol.

3. The polymer emulsion tackifier according to claim 1 or 2, wherein the isocyanate-modified acrylate monomer is prepared by a process comprising:

(i) Reacting isocyanate with hydroxyl-containing acrylate monomers to obtain a reactant 1;

(ii) Reacting the reactant 1 obtained in the step (i) with polymer polyol to obtain the isocyanate modified acrylic monomer;

preferably, the reaction of step (i) is carried out in the presence of a protective atmosphere;

preferably, the reaction system in the step (i) further comprises a catalyst and a polymerization inhibitor;

preferably, the content of the catalyst is 0.05-0.3% of the mass of isocyanate;

preferably, the catalyst comprises an organometallic catalyst;

preferably, the organometallic catalyst comprises at least one of stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dibutyrate or dioctyltin dilaurate;

preferably, the content of the polymerization inhibitor is 0.05-0.15% of the mass of the hydroxyl-containing acrylic ester monomer;

preferably, the polymerization inhibitor comprises at least one of hydroquinone, p-benzoquinone, p-hydroxyanisole or tert-butylhydroquinone.

4. A polymer emulsion tackifier according to claim 3, wherein the temperature of the reaction of step (i) is from 30 to 60 ℃;

preferably, the reaction time of step (i) is 1 to 3 hours;

preferably, the temperature of the reaction in step (ii) is 60 to 80 ℃;

preferably, the reaction in step (ii) takes 1 to 2 hours.

5. The polymer emulsion tackifier according to any of claims 1-4 wherein the first acrylic monomer comprises a C2-C15 alkyl acrylate;

preferably, the first acrylic monomer comprises at least one of ethyl acrylate, butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate or laurate acrylate, preferably butyl acrylate;

preferably, the third acrylic monomer comprises an acrylic monomer containing hydroxyl and/or amino;

preferably, the third acrylate monomer comprises hydroxyethyl acrylate and/or hydroxypropyl acrylate;

preferably, the fourth acrylate monomer comprises a carboxyl-containing acrylate monomer;

preferably, the carboxyl-containing acrylate monomer comprises beta-acryloxypropionic acid and/or beta-methacryloxypropionic acid, preferably beta-acryloxypropionic acid;

preferably, the mass ratio of the first acrylic ester monomer to the second acrylic ester monomer to the third acrylic ester monomer to the fourth acrylic ester monomer is 100 (30-50): 5-10): 10-20.

6. The polymer emulsion tackifier according to any of claims 1 to 5 wherein the initiator is used in an amount of 0.1 to 1% of the total mass of the monomers;

preferably, the initiator comprises at least one of a peroxide-based initiator, an azo-based initiator, or a redox initiator;

preferably, the initiator comprises at least one of potassium persulfate, ammonium persulfate, potassium persulfate-sodium sulfite, hydrogen peroxide or azobisisobutyrimidine hydrochloride, preferably potassium persulfate and/or ammonium persulfate;

preferably, the content of the emulsifier is 0.2-1% of the total mass of the monomers;

preferably, the emulsifier comprises an anionic emulsifier and/or a nonionic emulsifier;

preferably, the emulsifier comprises at least one of alkylphenol ethoxylates, alkylphenol ethoxylate ammonium sulfate, ethoxylated sodium alkyl sulfate or polyoxyethylene ether castor oil ester;

preferably, the preparation raw material of the polymer emulsion tackifier also comprises a chain transfer agent;

preferably, the chain transfer agent is used in an amount of 0.5 to 3% of the total mass of the monomers;

preferably, the chain transfer agent comprises a mercapto compound;

preferably, the chain transfer agent comprises at least one of butyl mercaptan, t-butyl mercaptan, dodecyl mercaptan, mercaptoethanol or mercaptopropionic acid, more preferably mercaptoethanol and/or mercaptopropionic acid.

7. A method of preparing a polymeric adhesion promoter according to any one of claims 1 to 6, comprising:

(1) Mixing a first acrylic monomer, a second acrylic monomer, a third acrylic monomer, a fourth acrylic monomer, an emulsifier and a solvent, and pre-emulsifying to obtain a monomer pre-emulsion;

(2) Mixing 10-30% of the total mass of the monomer pre-emulsion obtained in the step (1) with an initiator with the formula amount of 30-50%, and carrying out polymerization reaction to obtain seed emulsion;

(3) Mixing the seed emulsion obtained in the step (2) with residual monomer pre-emulsion and residual initiator, and reacting to obtain the polymer emulsion tackifier.

8. The method of claim 7, wherein the mixed feedstock of step (1) further comprises a chain transfer agent;

preferably, the method of pre-emulsification of step (1) comprises shear emulsification;

preferably, the rotation speed of the shearing is 300-800 r/min;

preferably, the temperature of the polymerization reaction in the step (2) is 50-80 ℃;

preferably, the polymerization reaction time in the step (2) is 1-3 h;

preferably, the mixing of step (3) comprises sequentially dropping the residual monomer pre-emulsion, the residual initiator into the seed emulsion;

preferably, the dripping time of the residual monomer pre-emulsion is 3-5 h;

preferably, the dripping time of the residual initiator is 4-6 hours;

preferably, the temperature of the reaction in the step (3) is 55-95 ℃;

preferably, the reaction time in the step (3) is 2-5 h;

preferably, the solid content of the polymer emulsion tackifier is 40-60%.

9. An acrylic adhesive comprising an acrylic latex emulsion and the polymer emulsion tackifier according to any one of claims 1 to 6.

10. The acrylic adhesive according to claim 9, wherein the effective mass percentage of the polymer emulsion tackifier in the acrylic adhesive is 2-6%.