KR20120051596A - Manufacturing method for adhesive tape without using toluene - Google Patents

Abstract

PURPOSE: A manufacturing method of a tape is provided to use toluene not at all, thereby manufacturing environment-friendly industrial tape fundamentally excluding the detect-possibility of toluene which is very dangerous for human body. CONSTITUTION: A manufacturing method of a tape comprises: a step of manufacturing a first mixture by mixing a polymerization initiator and an adhesive base which has an acrylic polymer and a functional group as raw material into a solvent containing ethyl acetate, acetone and isopropyl alcohol solely or blendly, without containing toluene, and obtaining acrylic adhesive through a partial retarding reaction; and a step of manufacturing a second mixture by mixing methyl isobutyl ketone into an acrylic adhesive, and coating the second mixture on a substrate.

Description

Manufacturing method for adhesive tape without using toluene

The present invention relates to a method for manufacturing an industrial double-sided or single-sided protective tape, and more particularly, in the method of manufacturing an industrial protective tape widely used in mobile phones, displays (TV), automobiles, and other various industrial fields, toluene is not used at all. It relates to a method for producing a tape.

Electronic products are completed by the combination of several parts. Industrial tape plays an important role in slimmer and ultra-lightweight electronic products, and greatly improves productivity and reduces manufacturing costs by simplifying the manufacturing process of electronic products and reducing manufacturing time. .

For example, the number of tapes used in the manufacture of mobile phones is about 50 to 70, and the dependence on navigation, TVs (LCDs, LEDs), PCs, and other home appliances for tapes is increasing. In addition, the application of industrial tape is not limited to home appliances, but also brings new manufacturing innovations in the automobile industry, such as fuel efficiency improvement and manufacturing process innovation.

In manufacturing such a variety of industrial tapes, acrylic is the most applied material. Acrylic has a low cost of raw materials, very easy synthesis of polymers, good functionality, and good compatibility with various additives.

However, the existing industrial tapes made of acryl have a large amount of toluene in the manufacturing process, fixing the polymer synthesis, adjusting the viscosity for processing the polymer, processing for securing the coating property, and mixing the additive for imparting the functionality. There is a problem being used.

Toluene is highly hazardous and industrially restricted, especially in industrialized countries where environmental aspects are emphasized.

Residual toluene produced during the production of acrylic industrial tape is substantially removed by hot air, IR drying, and UV drying in the manufacturing process, but trace amounts of toluene are not fundamentally removed, and there is a possibility of remaining on the tape.

Thus, if possible, blocking the use of toluene throughout the entire process of industrial tape manufacture may be the most useful way to dispel the concerns about toluene.

Republic of Korea Patent No. 10-0942311-0000 (Date: 2010. 02. 05) "ultraviolet curable adhesive, a manufacturing method thereof, and a flat panel front surface adhesion method using the same", "cover the front of the flat panel display UV curable adhesive for bonding plates, polyurethane acrylate oligomer 5 to 50% by weight, acrylate monomer 1 to 30% by weight, UV non-reactive resin 30 to 90% by weight, photoinitiator 0.1 to 5% by weight, light sensitization An ultraviolet curable adhesive comprising 0.05 to 5 wt%, and an adhesion promoter of 0.05 to 5 wt%, the present invention also provides a method for producing an ultraviolet curable adhesive, and a flat panel display front cover plate using an ultraviolet curable adhesive. Method for adhering the same.

An object of the present invention is to develop and provide a method for producing a tape that does not use toluene in the production of an acrylic industrial tape.

In order to achieve the above object, the present invention includes a method of producing an acrylic pressure-sensitive adhesive coated tape, including ethyl acetate, acetone, and isopropyl alcohol alone or in combination, toluene (A) obtaining an acrylic pressure-sensitive adhesive by mixing a pressure-sensitive adhesive base and a polymerization initiator as an raw material with an acrylic polymer and a functional group to a solvent not added thereto to prepare a first mixture, and then partially delaying the reaction; And (b) preparing a second mixture by mixing methyl isobutyl ketone (Methyl Iso Butyl Ketone) with the acrylic pressure-sensitive adhesive obtained above, and then coating (b) with a substrate for preparing a tape. It provides a manufacturing method.

Or less, it will be described in detail by breaking down the solution of the problem of the present invention step by step.

[Step a: In the method for producing a tape coated with an acrylic pressure-sensitive adhesive, ethyl acetate ( Ethyl acetate ), Acetone ( Acetone ) And Iso propyl alcohol  A pressure-sensitive adhesive base comprising, alone or in combination, an acrylic polymer and a functional group as a raw material in a solvent not added toluene, and Polymerization initiator  After preparing the first mixture by mixing, obtaining a acrylic pressure-sensitive adhesive by a partial delay reaction]

This step 1 includes ethyl acetate, acetone, and isopropyl alcohol alone or in combination, and includes an acrylic polymer and a functional group as a raw material in a solvent free of toluene. And mixing the polymerization initiator to prepare a first mixture, and then obtaining a acrylic pressure-sensitive adhesive by performing partial delay reaction.

The conventional method of synthesizing the pressure-sensitive adhesive is a batch reaction method in which an acrylic polymer, an organic solvent, and a polymerization initiator are mixed and stirred in one reactor, and then heated and reacted at one time. This is the preferred method for synthesizing existing adhesives due to the simplicity of the reaction and the convenience of manufacturing.

However, batch reactions are difficult to control for transient explosive reactions, and toluene is required for the overall reaction. Toluene is indispensable in the batch reaction method because it effectively controls the instantaneous heat generated during the synthesis of the pressure sensitive adhesive, is used as a diluent for adjusting the viscosity of the synthesized pressure sensitive adhesive, and is also used as an additive for imparting coating functionality. .

In the present invention, in order to exclude the use of toluene in the production of acrylic pressure-sensitive adhesives, a new solvent composition is developed, and a method of developing a reaction by dividing the entire reactant for a predetermined time (hereinafter, referred to as a partial delay reaction method) is to be used.

In the present invention, as a solvent which can replace toluene in the partial delay reaction method, ethyl acetate, acetone, and isopropyl alcohol may be included alone or in combination, without adding toluene. Develop and provide a solvent. Ethyl acetate used as the main solvent to facilitate the synthesis of the acrylic polymer, can be used as a viscosity control diluent of the prepared acrylic polymer.

Ethyl acetate exhibits optimal performance when the added amount is 30 to 80% by weight of the total solvent. In particular, the optimum coating performance and high gloss of the surface is maintained at 50 to 60% by weight of the total solvent. Acetone and isopropyl alcohol show optimum processability only when the amount added is within 40% by weight of the total solvent.

On the other hand, the partial delayed reaction method used in the present invention modifies the physical properties of the polymer, and instead of the addition of general low molecular materials used for imparting the functionality of the pressure-sensitive adhesive, by controlling the reaction time and the initiator during the reaction, one molecular weight is controlled. Is to synthesize polymer and low molecular weight at the same time.

The partial delayed reaction method of the present invention preferably comprises an initial reaction step (a-1) of pre-reacting 30-50% by weight of the total reactants; After completion of the initial reaction, the polymer growth induction step of maintaining for 0.5 to 4 hours to allow the initial reactants to fully grow into the polymer (a-2); After the polymer growth induction, a late reaction step of sequentially reacting the remaining amount of the total reactants for 60 to 120 minutes (a-3); After the late reaction, to reduce the unreacted monomer, and to add an excess polymerization initiator in order to improve the conversion rate, the ripening step of maintaining for 90 to 180 minutes (a-4); And after aging, terminating the reaction by quenching and diluent addition step (a-5); it is preferably carried out through a process comprising a.

Hereinafter, the partial delay reaction method of the present invention will be described in detail by subdividing each step.

 {Initial reaction step (a-1)}

In the partial delayed reaction of the present invention, 30 to 50% by weight of the total reactants are first reacted at the beginning of the reaction. At this time, the solvent which uses ethyl acetate as a main material is used as a solvent. Since the addition of traces of alcohol in the initial reaction acts as a chain transfer agent as a determinant control factor of polymer growth, which causes enormous obstacles to the average molecular weight growth, the addition of alcohol in the initial reaction is not more than 3% by weight of the total solvent good.

 {Polymer Growth Induction Stage (a-2)}

In a partially delayed reaction, a period of time after the completion of the initial reaction must be maintained to allow the initial reactants to grow sufficiently into polymers. The holding time can be from 0.5 hours (30 minutes) up to 4 hours. At this time, it is most preferable to maintain the time of 60 minutes to 90 minutes for optimum performance and productivity improvement.

 {Late reaction step (a-3)}

In the later reaction, the remaining unreacted initial reaction of the total reactants is sequentially reacted for 60 to 120 minutes. Through this process, the polymer synthesized in the initial reaction and the polymer and oligomer synthesized in the late reaction are mixed with each other, thereby eliminating a series of additive addition processes performed after the completion of the final reaction to improve physical properties.

 {Maturation Stage (a-4)}

After the late reaction, in order to drastically reduce the unreacted monomers and improve the conversion rate, an excessive amount of the polymerization initiator added in the initial reaction stage is added again, and then a aging process is performed for about 90 to 180 minutes.

The aging process can dramatically reduce the intrinsic odor derived from unreacted monomers coming to the end product from unpleasant odor. Unreacted monomer is a very harmful component to the human body, it is possible to significantly reduce the number of unreacted monomers remaining in the final product by improving the conversion rate.

 {Termination step (a-5)}

After the aging process to remove the unreacted monomer, the reaction is terminated by quenching and diluent addition. Diluents can be used without limitation to those known in the art.

[Step b: methyl isobutyl ketone ( Methyl Iso Butyl Ketone ) From above The obtained  After mixing the acrylic pressure-sensitive adhesive to prepare a second mixture, the step of coating on a tape manufacturing substrate]

In step 2, methyl isobutyl ketone (Methyl Iso Butyl Ketone) is mixed with the acrylic pressure-sensitive adhesive obtained above to prepare a second mixture, and then a step of coating on a tape manufacturing substrate.

As a method of coating the pressure-sensitive adhesive to the substrate for tape production, a roll to roll method is most often used. In order to coat the pressure-sensitive adhesive on the tape manufacturing substrate, it is necessary to undergo a coating process such as adjusting the viscosity of the pressure-sensitive adhesive and improving the surface glossiness. Toluene is also most commonly used.

Ethyl acetate used as a toluene substitute in the preparation of the acrylic adhesive in step 1 has a boiling point of 78 ° C., which is lower than that of toluene (110 ° C.). Increasing the keratinization of the surface caused a decrease in surface glossiness.

Therefore, in the present invention, a very small amount of high boiling point solvent was used to delay the surface keratinization and to produce an industrial tape having excellent surface glossiness. As the material, methyl isobutyl ketone was used.

As a result of comparing the surface glossiness of the tape according to the amount of methyl isobutyl ketone, the surface gloss was improved up to 5% by weight of methyl isobutyl ketone. There was a problem that the drying occurs.

Therefore, methyl isobutyl ketone added in the coating process of the pressure-sensitive adhesive is preferably used at most 5% by weight.

On the other hand, the tape manufacturing substrate is preferably any one selected from PET, PE and paper, but is not necessarily limited thereto.

On the other hand, the tape of the present invention is preferably a single-sided or double-sided tape.

In the following experimental example, the acrylic pressure-sensitive adhesive was prepared by the partial delay reaction method without using toluene. As a result, the single reaction amount increased up to 35% compared to the batch reaction method using toluene.

In addition, the manufacturing method of the tape of the present invention enables the production of environmentally friendly industrial tape which essentially excludes the possibility of detecting toluene having a very high risk of human body.

Hereinafter, the content of the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited only to the following examples, and includes modifications of equivalent technical ideas.

[ Example  1: Synthesis of Acrylic Polymer Using Ethyl Acetate Instead of Toluene]

In Example 1, acryl polymer was synthesized using ethyl acetate as the main solvent, without using toluene.

material Sample-1 Sample-2 Sample-3 Sample-4 Sample-5 Total ^{1 )}
Adhesive base

Main monomer 2-EHA 50 wt%
100
Butyl acrylate
(BA, butyl acrylate) 25% by weight Ethyl acrylate
(EA, ethyl acrylate) 20 wt% Functional group Acrylic acid
(AA, Acryl Acid) 5 wt% Polymerization initiator AIBN 0.5 0.5 solvent

Acetone
(Acetone) 10 wt% 29% by weight 50 wt%
100
Ethyl acetate
(EAc, Ethyl acetate) 90 wt% 70 wt% 50 wt% 90 wt% 70 wt% Isopropyl Alcohol
(IPA, Iso Propyl Alcohol) 1 wt% 10 wt% 30 wt% Note 1) The mixing ratio between the adhesive base, the polymerization initiator and the solvent means parts by weight. For example, the adhesive base 100kg, polymerization initiator 0.5kg, solvent 100kg is mixed.

On the other hand, Table 2 is a result of the boiling point and the boiling point of toluene of the solvents used and the solvents commonly used above.

division Boiling point (℃) Toluene 110 Ethyl acetate (EAc) 78 Hexane 69 Acetone 56 Methyl Ethyl Ketone (MEK) 79 Iso Propyl Alcohol (IPA) 82 Methyl Iso Butyl Ketone (MIBK) 116

[ Experimental Example  1: solid content according to the amount of ethyl acetate added Volatility ) And viscosity]

In the present experimental example, the viscosity and nonvolatile content were measured for the samples of Table 1 except for adding toluene and using acetylacetate as the main solvent.

Solid content (%) ^{1 )} Viscosity (25 degrees) cps ²⁾ Sample-1 60 13500 Sample-2 55 8800 Sample-3 50 5600 Sample-4 45 4200 Sample-5 40 3050 1)% by weight
2) relative viscosity

[ Experimental Example  2: Comparison of Differences in the Degree of Response between Batch and Partial Delayed Reactions]

In the present experimental example, a batch reaction method in which one reaction station is mixed with an organic polymer and an initiator including toluene and a polymerization initiator with the most common composition among the existing polymer synthesis methods, is stirred, and then heated and reacted at once. In the present invention, after performing the partial delayed reaction method to remove the toluene and dividing the entire reactant for a certain time, the reaction state, the reactivity and the degree of reaction amount were compared and analyzed.

The partial delay reaction was performed by the following procedure using the composition of Sample 2 in the composition described in Table 1 above. First, 40% by weight of the total reactants were pre-reacted and held for 2 hours to allow the initial reactants to grow sufficiently into polymers. Thereafter, a late reaction was performed in which the remaining amount of the total reactants was sequentially reacted for 90 minutes. After the late reaction, an excessive amount of AIBN was added as a polymerization initiator capable of reacting with the unreacted monomer, and maintained for about 120 minutes. The reaction was then terminated through quenching and diluent addition.

division Batch reaction Partial delay reaction Main solvent Acetic acid, toluene, alcohol Acetic acid, alcohol, acetone Reaction status Hard reaction Soft reaction Responsive Initial reaction: violent reaction
Response: Go smoothly Initial reaction: slow reaction
Reaction: Very sensitive reaction Reaction 70% of the total reactor 95% level of the total reactor

As a result of comparing the reaction degree difference between the batch reaction method and the partial delay reaction method (Table 4), in the reaction state, the batch reaction method reacts violently at the beginning of the reaction. While the reaction proceeded slowly, the reaction was confirmed that the reaction is very sensitive.

In addition, the reaction rate of the batch reaction method was 70% of the total reactor, whereas the partial delay reaction method was 95% of the total reactor, showing a very high degree of reaction.

From the above results, the partial delayed reaction could increase the reaction amount by up to 35% compared with the conventional batch reaction method, which acts as a decisive factor in absorbing the production cost increase due to the exclusion of toluene. And it was found.

[ Experimental Example  3: Methyl Isobutyl Ketone ( MIBK , Methyl Iso Butyl Ketone Comparison of Surface Glossiness with Addition]

In the present experimental example, the surface glossiness of the tapes according to the addition of methyl isobutyl ketone (MIBK, Methyl Iso Butyl Ketone) when the acrylic adhesive was coated on the tape was compared.

Addition amount (in total solvent amount) Surface condition MIBK 1% added Deterioration of surface gloss MIBK 3% added Improved surface gloss MIBK 5% added Excellent surface gloss MIBK 10% added Undried occurrence

As a result of the measurement (Table 5), the use of methyl isobutyl ketone (MIBK, Methyl Iso Butyl Ketone) was improved. The degree of surface gloss was improved, and methyl isobutyl ketone (MIBK, Methyl Iso Butyl Ketone) was confirmed. ) Was not dried when the used amount exceeded 5% by weight.

Claims (6)

In the method for producing a tape coated with an acrylic adhesive,
Ethyl acetate, Acetone and Iso propyl alcohol may be included alone or in combination. Toluene-containing solvents are used as adhesive bases and polymerization initiators based on acrylic polymers and functional groups. Preparing a first mixture by mixing and then obtaining a acrylic pressure-sensitive adhesive by partially delayed reaction (a); And,
Preparing a second mixture by mixing methyl isobutyl ketone (Methyl Iso Butyl Ketone) with the acrylic pressure-sensitive adhesive obtained above, and then coating the substrate for preparing a tape (b); . The method of claim 1,
The solvent,
Ethyl acetate is 30 to 80% by weight of the total amount of the solvent production method of the tape, characterized in that mixed. The method of claim 1,
The partial delay reaction
Initial reaction step (a-1) of pre-reacting 30-50% by weight of the total reactants;
After completion of the initial reaction, the polymer growth induction step of maintaining for 0.5 to 4 hours to allow the initial reactants to fully grow into the polymer (a-2);
After the polymer growth induction, a late reaction step of sequentially reacting the remaining amount of the total reactants for 60 to 120 minutes (a-3);
After the late reaction, to reduce the unreacted monomer, and to add an excess polymerization initiator in order to improve the conversion rate, the ripening step of maintaining for 90 to 180 minutes (a-4); And
After aging, terminating the reaction through quenching and diluent addition step (a-5); tape manufacturing method characterized in that carried out through the process comprising a. The method of claim 1,
Methyl Iso Butyl Ketone,
Tape manufacturing method, characterized in that up to 5% by weight of the total amount of solvent used. The method of claim 1,
The base material for tape manufacturing,
Tape manufacturing method, characterized in that any one selected from PET, PE and paper. The method of claim 1,
The tape is
Method for producing a tape, characterized in that the single-sided or double-sided tape.