KR101981539B1 - Acrylic pressure sensitive adhesive composition having excellent flame retardancy and adhesion - Google Patents

Abstract

The present invention relates to an acrylic pressure sensitive adhesive composition having excellent flame retardancy and adhesiveness. More specifically, unlike the prior art in which a flame retardant is simply added to an acrylic pressure sensitive adhesive, the acrylic pressure sensitive adhesive is chemically bonded using a functional acrylic monomer having flame retardancy It is possible to solve the problem of deterioration in adhesion due to the use of the conventional flame retardant. In addition, in applying the bulk polymerization method to the acrylic pressure-sensitive adhesive as described above, the organic solvent is not used, In addition, by applying a reaction promoter during bulk polymerization, it is possible to perform reaction at a low temperature, thereby facilitating control of the reaction heat generated in the production of an acrylic pressure-sensitive adhesive, thereby making it possible to stably produce a pressure- It relates to a composition.

Description

[0001] The present invention relates to an acrylic pressure sensitive adhesive composition having excellent flame retardancy and adhesion,

Unlike the conventional art in which a flame retardant is simply added to an acryl-based tackifier, the present invention provides a method for producing an acryl-based tackifier, which comprises chemically bonding a functional acrylic monomer having flame-retardant properties to produce excellent flame retardancy, In addition, since the bulk polymerization method is applied to the acrylic pressure-sensitive adhesive to produce the above-mentioned acrylic pressure-sensitive adhesive, it is not environmentally-friendly because an organic solvent is not used. In addition, reaction can be performed at a low temperature by applying a reaction promoter during bulk polymerization, The present invention relates to an acrylic pressure-sensitive adhesive composition having excellent flame retardancy and adhesion, which makes it possible to control the reaction heat generated in the pressure-sensitive adhesive composition in a stable manner.

A variety of pressure-sensitive adhesive polymer materials used for various purposes in various industries are mostly used as solvent-type products dissolved in volatile organic solvents. Recently, due to environmental regulations regarding volatile organic solvents, there is a great social demand to convert the solvent-type pressure-sensitive adhesive polymer materials currently used into environmentally friendly water-dispersible emulsion polymer materials not containing organic solvents.

Particularly, since volatile organic solvents such as toluene and methanol used in the solvent type pressure-sensitive adhesive manufacturing process are badly volatile and work environment is poor, such a process may affect the human body in various forms for a long time, need.

Therefore, the water-dispersed emulsion type pressure-sensitive adhesive which does not use the organic solvent which is currently being produced has a quality and function of a solvent type mainly in the acrylic system, and the main use of such an acrylic pressure-sensitive adhesive is a general application such as electric, electronic, automobile, Research is being carried out in the direction of demanding high performance, functionality, and high strength for industrial use.

In particular, regulations on various materials for environment-friendly and fire prevention are intensifying worldwide, and the use of environmentally friendly materials and flame retardant products in which polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) are not detected is becoming mandatory.

Therefore, in Patent Documents 1 and 2, an acrylic pressure-sensitive adhesive having flame retardancy has been proposed by adding a flame retardant to an acrylic pressure-sensitive adhesive. However, such a conventional acrylic pressure-sensitive adhesive has a satisfactory level of flame retardancy (Generally 50 parts by weight or more of a flame retardant per 100 parts by weight of the pressure-sensitive adhesive) must be added.

In addition, the addition of a large amount of flame retardant causes an increase in product cost due to excessive use of the flame retardant agent, and in particular, the use of an excessive flame retardant deteriorates the adhesive strength.

Patent Document 1: Korean Patent Laid-Open Publication No. 10-2015-0120072 " Composition of aqueous dispersion type acrylic pressure-sensitive adhesive, Patent Document 2: Korean Registered Patent Application No. 10-1148762 " Acrylic Emulsion Pressure-Sensitive Adhesive Composition Improved in Tackiness and Flame Retardancy and Method for Producing the Same "

Disclosure of the Invention The present invention has been made to solve the above problems and it is an object of the present invention to provide an acrylic pressure sensitive adhesive which is chemically bonded using a functional acrylic monomer having flame retardancy, And it is an object of the present invention to solve the problem of deterioration of adhesion due to use of an excessive flame retardant.

In addition, since the present invention adopts the bulk polymerization method in the production of the acrylic pressure-sensitive adhesive as described above, it is not environmentally-friendly because an organic solvent is not used. In addition, reaction can be performed at a low temperature by applying a reaction promoter during bulk polymerization, And the control of the reaction heat generated is facilitated, thereby making it possible to stably produce the pressure sensitive adhesive.

The present invention relates to an acrylic pressure-sensitive adhesive composition, which comprises an acrylic pressure-sensitive adhesive composition having excellent flame retardancy and adhesiveness, which comprises an acrylic monomer mixture comprising an acrylic monomer and a functional acrylic monomer, and a polymerization initiator and a reaction accelerator do.

More specifically, the acrylic pressure sensitive adhesive composition comprises 0.1 to 5.0 parts by weight of a polymerization initiator and 0.1 to 5.0 parts by weight of a reaction promoter, based on 100 parts by weight of an acrylic monomer mixture comprising 50 to 90% by weight of an acrylic monomer and 10 to 50% by weight of a functional acrylic monomer And the like.

The acrylic monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (metha) acrylate ), Isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (metha) acrylate, sec-butyl (metha) acrylate, pentyl (metha) acrylate, 2-ethylhexyl (metha) acrylate, acrylate, n-octyl (metha) acrylate, isooctyl (meth) acrylate, decyl (metha) acrylate, Isodecyl (metha) acrylate, isononyl (metha) acrylate, isobonyl (metha) acrylate, lauryl )acryl (Meth) acrylate, tetradecyl (metha) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, metha) acrylate or acrylic acid, or a combination of two or more thereof.

The functional acrylic monomer may be a phosphorus (meth) acryl monomer having flame retardancy, such as dimethyl (methacryloyloxymethyl) phosphonate, dimethyl (methacryloyloxyethyl) phosphonate (Methacryloyloxyethyl) phosphonate, dimethyl (acryloyloxyethyl) phosphonate, methylethyl (methacryloyloxymethyl) phosphonate, methyl ethyl (Acryloyloxymethyl) phosphonate, diethyl (methacryloyloxymethyl) phosphonate, diethyl (methacryloyloxyethyl) phosphonate, (Methacryloyloxyethyl) phosphonate, diethyl (acryloyloxymethyl) phosphonate, dipropyl (methacryloyloxymethyl) phosphone (Methacryloyloxyethyl) phosphonate, dipropyl (methacryloyloxyethyl) phosphonate, diethyl (hydroxymethyl) phosphonate, or bis [ And 2- (methacryloyloxyethyl) phosphonate (Bis [2- (methacryloyloxyethyl)] phosphate) may be used alone or in combination of two or more.

The polymerization initiator may be used alone or in combination of two or more among azo-based and peroxide-based polymerization initiators.

The reaction promoter may be selected from the group consisting of dimethyl-p-toluidine, dimethylaniline, diethyl aniline, ethyl-m-toluidine, pyridine, Phenyl morpholine, piperidines or diethanol aniline may be used alone or in combination of two or more thereof.

Unlike the conventional art in which a flame retardant is simply added to an acryl-based tackifier, the present invention provides a method for producing an acryl-based tackifier, which comprises chemically bonding a functional acrylic monomer having flame-retardant properties to produce excellent flame retardancy, It has the effect of solving the problem.

In addition, since the present invention adopts the bulk polymerization method in the production of the acrylic pressure-sensitive adhesive as described above, it is not environmentally-friendly because an organic solvent is not used. In addition, reaction can be performed at a low temperature by applying a reaction promoter during bulk polymerization, The reaction heat generated can be easily controlled and the pressure sensitive adhesive can be stably produced.

The present invention relates to an acrylic pressure sensitive adhesive composition having excellent flame retardancy and adhesiveness. The acrylic pressure sensitive adhesive composition of the present invention is required to understand the technical structure of the present invention, and the description of other portions is not intended to disturb the gist of the present invention. It will be omitted.

Hereinafter, the acrylic pressure-sensitive adhesive composition having excellent flame retardancy and adhesiveness according to the present invention will be described in detail.

The present invention relates to an acrylic pressure sensitive adhesive composition, which comprises an acrylic monomer mixture composed of an acrylic monomer and a functional acrylic monomer, a polymerization initiator and a reaction accelerator, more specifically, 50 to 90% by weight of an acrylic monomer, 0.1 to 5.0 parts by weight of a polymerization initiator and 0.1 to 5.0 parts by weight of a reaction promoter, based on 100 parts by weight of an acrylic monomer mixture comprising 10 to 50% by weight of a polymerization initiator.

The general acrylic monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (metha) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (metha) acrylate, acrylate, sec-butyl (metha) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methacrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (metha) acrylate Isodecyl (metha) acrylate, isononyl (metha) acrylate, isobonyl (metha) acrylate, lauryl (meth) acrylate Meta) Acrylates such as lauryl (metha) acrylate and tetradecyl (metha) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, (metha) acrylate) or acrylic acid alone or in combination of two or more.

In addition, the functional acrylic monomer may be a phosphorus (meth) acryl monomer having flame retardancy, such as dimethyl (methacryloyloxymethyl) phosphonate, dimethyl (methacryloyloxyethyl) Dimethyl (methacryloyloxyethyl) phosphonate, dimethyl (acryloyloxyethyl) phosphonate, methylethyl (methacryloyloxymethyl) phosphonate, methyl (Methacryloyloxymethyl) phosphonate, diethyl (methacryloyloxymethyl) phosphonate, diethyl (methacryloyloxyethyl) phosphonate, (Methacryloyloxyethyl) phosphonate, diethyl (acryloyloxymethyl) phosphonate, dipropyl (methacryloyloxymethyl) phosphonate, (Methacryloyloxyethyl) phosphonate, dipropyl (methacryloyloxyethyl) phosphonate, diethyl (hydroxymethyl) phosphonate, or bis [ And 2- (methacryloyloxyethyl) phosphonate (Bis [2- (methacryloyloxyethyl)] phosphate) may be used alone or in combination of two or more.

Meanwhile, the general acrylic monomer and the functional acrylic monomer are not limited to those listed above, and various known general acrylic monomers and functional acrylic monomers can be used.

On the other hand, when the content of the general acrylic monomer is less than 50% by weight and the content of the functional acrylic monomer is more than 50% by weight, there is a possibility that the pressure-sensitive adhesive may not be polymerized properly, and the content of the general acrylic monomer is 90% And the content of the functional acrylic monomer is less than 10% by weight, the flame retardancy may be lowered.

When the content of the polymerization initiator is less than 0.1 parts by weight, the unreacted monomer may remain in the composition. When the amount of the polymerization initiator is more than 5.0 parts by weight, .

As the polymerization initiator, azo-based and peroxide-based polymerization initiators may be used. Specific examples of the azo-based polymerization initiator include azobisisobutyronitrile, azonitrile, Azo ester, azo amide, azo amidine or azo imidazoline may be used as the peroxide type polymerization initiator and benzoyl peroxide may be used as the peroxide type polymerization initiator. Di-tert-butyl peroxide, cumyl hydroperoxide, hydrogen peroxide, and the like. The term " hydrogen peroxide " Can be used. In addition to the above polymerization initiators, well-known acetal, hemiacetal, and redox polymerization initiators may be used, and the present invention is not limited to the above listed materials, and various known polymerization initiators may be used This is possible.

The reaction promoter is a reaction promoter for bulk polymerization. In the present invention, bulk polymerization is used without any organic solvent. Specifically, the bulk polymerization is a known method in which only a unit is polymerized, such as heat or light, without using a solvent. On the other hand, it is known that it is difficult to obtain a material having a high polymerization degree because it is difficult to remove the heat of reaction although the polymerization rate is high in the bulk polymerization. Therefore, the present invention initiates a reaction by forming a radical by decomposition of a reaction promoter using a reaction promoter, so that the reaction proceeds at a relatively low temperature and the reaction is arbitrarily terminated at a point of time when the viscosity is rapidly increased. The reaction heat generated is easily controlled, thereby making it possible to stably produce a pressure-sensitive adhesive. On the other hand, the polymerization conditions and apparatus for bulk polymerization are not limited to specific conditions and apparatus types, and various well-known conditions and apparatuses can be applied.

Examples of the reaction accelerator include dimethyl-p-toluidine, dimethylaniline, diethyl aniline, ethyl-m-toluidine, pyridine, But are not limited to, phenylmorpholine, piperidines or diethanol aniline. However, the present invention is not limited to the use of various reaction accelerators capable of performing the above functions, If the content is less than 0.1 part by weight, there is a possibility that the reaction heat control efficiency becomes insufficient. If the content is more than 5.0 parts by weight, the viscosity may rise sharply.

In addition, each of the compositions described above may be added one more time after completion of the process as described above to further perform the reaction.

On the other hand, the acrylic pressure-sensitive adhesive composition having excellent flame retardancy and adhesiveness can be selectively applied with additives such as a tackifier, a plasticizer, a process oil, and an acrylate oligomer in consideration of the object, object to be used, environment, Known additives already used in the pressure-sensitive adhesive composition field are not described in detail. In addition to the additives listed above, various additives already known can be applied.

Hereinafter, the present invention will be described in detail with reference to examples thereof, but the present invention is not necessarily limited to the following examples.

1. Preparation of acrylic adhesive

(Example 1)

(Methyl methacrylate 20% by weight + n-butyl (meth) acrylate 65% by weight + acrylic acid 5% by weight) and 90% by weight of a functional acrylic monomer, bis [2- (methacryloyloxyethyl 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator and 0.1 part by weight of dimethylaniline as a reaction promoter were mixed with 100 parts by weight of an acrylic monomer mixture comprising 10% by weight of a phosphonate Thin film evaporator) was used to remove the unreacted monomer and the reaction promoter added to control the reaction heat to prepare an acrylic pressure sensitive adhesive.

(Example 2)

(Methacryloyloxyethyl) phosphonate 30, which is a functional acrylic monomer, and 70 wt% of a general acrylic monomer (ethyl methacrylate 7 wt% + t-butyl (meth) acrylate 63 wt% , 0.1 part by weight of benzoyl peroxide as a polymerization initiator and 0.1 part by weight of dimethylaniline as a reaction promoter were mixed with 100 parts by weight of an acrylic monomer mixture composed of 100 wt% The acrylic pressure sensitive adhesive was prepared by removing the monomer and the reaction promoter added for the reaction heat control.

(Example 3)

50 wt% of a general acrylic monomer (isopropyl (meth) acrylate 5 wt% + sec-butyl (meth) acrylate 45 wt%) and 50 wt% of dimethyl (methacryloyloxymethyl) phosphonate as a functional acrylic monomer , 5.0 parts by weight of benzoyl peroxide as a polymerization initiator and 5.0 parts by weight of dimethyl para-toluidine as a reaction promoter were mixed, and after bulk polymerization, the mixture was subjected to an unreacted reaction using a thin film evaporator The acrylic pressure sensitive adhesive was prepared by removing the monomer and the reaction promoter added for the reaction heat control.

(Comparative Example 1)

0.1 part by weight of benzoyl peroxide as a polymerization initiator and 100 parts by weight of a reaction accelerator were added to 100 parts by weight of a general acrylic monomer (20% by weight of methyl (meth) acrylate + 65% by weight of n-butyl (meth) acrylate + And 0.1 part by weight of dimethylaniline. After bulk polymerization, unreacted monomer and reaction promoter added for controlling the reaction heat were removed using a thin film evaporator to prepare an acrylic pressure-sensitive adhesive.

(Comparative Example 2)

5 parts by weight of azobisisobutyronitrile as a polymerization initiator was added to 100 parts by weight of a general acrylic monomer (10% by weight of isopropyl (meth) acrylate + 90% by weight of sec-butyl (meth) acrylate) And 5 parts by weight of dimethylaniline as a reaction promoter. After bulk polymerization, unreacted monomer and reaction promoter added for controlling the reaction heat were removed using a thin film evaporator to prepare an acrylic pressure-sensitive adhesive. Then, 50 parts by weight of aluminum hydroxide, which is a flame retardant, was separately mixed with 100 parts by weight of the acrylic pressure-sensitive adhesive prepared above.

2. Evaluation of acrylic adhesive

The adhesive strength and flame retardancy of the acrylic pressure sensitive adhesive prepared according to the Examples and Comparative Examples were evaluated. The results are shown in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesion ^{Note 1)}
(gk / inch) 1,500 1,400 1,000 1,500 500 Flammability ^{Note 2)} V-2 V-2 V-2 No flammability V-2 Note 1)
The acrylic pressure sensitive adhesive prepared according to Examples and Comparative Examples was applied to a PET film and dried to produce an adhesive film. After attaching the adhesive film to the adherend, the adhesive strength was evaluated by a texture analyzer. SUS (Steel, Use, Stainless) was used as the adhered material.

Note 2)
UL94 VB (flame retardancy of flame retardant plastic) test method.

As shown in Table 1, Examples 1 to 3 according to the present invention provide excellent flame retardancy by chemically bonding functional acrylic monomers having flame-retardant properties in the production of acrylic pressure-sensitive adhesives, It is possible to find an excellent adhesive force. On the other hand, in the case of Comparative Example 2, the flame retardant was simply added, and the flame retardancy could be realized by using 50 parts by weight of the flame retardant.

In addition, since the present invention adopts the bulk polymerization method in the production of the acrylic pressure-sensitive adhesive as described above, it is not environmentally-friendly because an organic solvent is not used. In addition, reaction can be performed at a low temperature by applying a reaction promoter during bulk polymerization, It is easy to control the reaction heat generated and thus it is possible to stably manufacture the pressure sensitive adhesive.

As described above, the acrylic pressure-sensitive adhesive composition having excellent flame retardancy and adhesiveness according to the present invention has been described through the above-described preferred embodiments, and its superiority has been confirmed. However, those skilled in the art will recognize that, It will be understood that various modifications and changes may be made thereto without departing from the spirit and scope of the invention.

Claims (6)

An acrylic pressure-sensitive adhesive composition comprising an acrylic monomer mixture comprising an acrylic monomer and a functional acrylic monomer, a polymerization initiator and a reaction promoter,
0.1 to 5.0 parts by weight of a polymerization initiator and 0.1 to 5.0 parts by weight of a reaction promoter based on 100 parts by weight of an acrylic monomer mixture comprising 50 to 90% by weight of an acrylic monomer and 10 to 50% by weight of a functional acrylic monomer,
The acrylic monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (metha) acrylate, Isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (metha) acrylate, sec-butyl (metha) acrylate, pentyl (metha) acrylate, 2-ethylhexyl (metha) acrylate acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (metha) acrylate, iso Acrylate, isodecyl (meth) acrylate, isononyl (metha) acrylate, isobonyl (metha) acrylate, lauryl (meth) acrylate, Rate ( lauryl (metha) acrylate, tetradecyl (metha) acrylate, benzyl (meth) acrylate, cyclohexyl (metha) acrylate, acrylate or acrylic acid, or a combination of two or more thereof,
The functional acrylic monomer is a phosphorus-containing (meth) acrylic monomer having flame retardancy, and includes dimethyl (methacryloyloxymethyl) phosphonate, dimethyl (methacryloyloxyethyl) phosphonate (methacryloyloxyethyl) phosphonate, dimethyl (acryloyloxyethyl) phosphonate, methylethyl (methacryloyloxymethyl) phosphonate, methylethyl (Methacryloyloxymethyl) phosphonate, diethyl (methacryloyloxymethyl) phosphonate, diethyl (methacryloyloxyethyl) phosphonate, (Diethyl (methacryloyloxyethyl) phosphonate), diethyl (acryloyloxymethyl) phosphonate, dipropyl (methacryloyloxymethyl) phosphonate (Dipr (methacryloyloxyethyl) phosphonate, dipropyl (methacryloyloxyethyl) phosphonate, diethyl (hydroxymethyl) phosphonate or bis [2- (Methacryloyloxyethyl) phosphate) alone or in combination of two or more thereof,
The polymerization initiator is used either singly or in combination of two or more among azo-based and peroxide-based polymerization initiators,
The reaction accelerator may be selected from the group consisting of dimethyl-p-toluidine, dimethylaniline, diethyl aniline, ethyl-m-toluidine, pyridine, Acrylic pressure-sensitive adhesive composition excellent in flame retardancy and adhesiveness, which is used either alone or in combination of two or more selected from the group consisting of Phenyl morpholine, Piperidines and Diethanol aniline. delete delete delete delete delete