KR101715818B1 - Method for preparation of an adhesive sheet - Google Patents

Abstract

The present invention relates to a method for producing an adhesive sheet. According to the method for producing the adhesive sheet, it is possible to produce adhesive sheets which are not cured until the adhesive sheets are applied to components but are cured after applied to the components when a temperature is raised by heat application, thereby remarkably increasing user convenience. To this end, the method for producing the adhesive sheet comprises the following steps: supplying a curing agent composition through an internal pipe of an electrospraying dual supply nozzle, and supplying a polymeric composition including polyvinylidene fluoride (PVDF) through an external pipe of the electrospraying dual supply nozzle; producing a potential curing agent by spraying the curing agent composition and the polymeric composition to a substrate through the electrospraying dual supply nozzle; producing a composition for forming the adhesive sheet by mixing the potential curing agent and an acrylic compound; and applying the composition for forming the adhesive sheets on a film.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a process for producing an adhesive sheet comprising a latent curing agent.

The adhesive sheet in the form of a film is used for fixing parts on both sides via a pressure-sensitive adhesive sheet, and is mainly made of an acrylic compound capable of imparting an adhesive force.

In general, the release film is removed from the pressure-sensitive adhesive sheet including the release film and attached to the surface of the first component, and then the second component is attached to the other surface of the pressure-sensitive adhesive sheet. In recent years, in addition to the use for bonding the first part and the second part, the pressure-sensitive adhesive sheet is required to have mechanical strength for reasons such as protection of each component.

For this purpose, a method of curing the adhesive sheet is used. For example, mechanical strength can be increased by curing a pressure-sensitive adhesive sheet by including a curing agent or a curing accelerator in the pressure-sensitive adhesive sheet. The pressure-sensitive adhesive sheet is generally in the form of a film, and since the pressure-sensitive adhesive sheet becomes hard when it is hardened, it is preferable that the adhesive sheet is cured after application to the component. Therefore, it is necessary that the curing is suppressed until the adhesive sheet is applied to the component, and the curing can proceed after the adhesive sheet is applied to the component.

In order to cure the acrylic compound, it is necessary to have an epoxy group and also to use a mixture of a curing agent or a curing accelerator. In this case, since the curing also proceeds at room temperature, curing can not be suppressed until the adhesive sheet is applied to the component. That is, if a curing agent or a curing accelerator is used for curing, since the curing is progressed before the adhesive sheet itself is applied to the parts, there is a problem that it is difficult to apply to the parts.

Accordingly, the present inventors have made intensive efforts to solve the above-mentioned disadvantages. As a result, the present inventors have found that, after applying the pressure-sensitive adhesive sheet to a component, the curing can be progressed when the temperature is raised by heating, And thus the present invention has been completed.

The present invention is to provide a method for producing a pressure-sensitive adhesive sheet including latent curing.

The present invention also provides a pressure-sensitive adhesive sheet produced by the above production method.

In order to solve the above-described problems, the present invention provides a method for preparing a polymer electrolyte fuel cell, comprising the steps of: 1) supplying a curing agent composition to an inner tube of an electrospray double feed nozzle and supplying the polymer composition to an outer tube of an electrospray double feed nozzle; 2) spraying the hardener composition and the polymer composition onto the substrate from the electrospray double feed nozzle to produce a latent curing agent; 3) mixing the latent curing agent and the acrylic compound to prepare a composition for forming a pressure-sensitive adhesive sheet; And 4) applying the composition for forming a pressure-sensitive adhesive sheet onto a film.

Hereinafter, the present invention will be described in detail.

Step 1 and Step 2

Step 1 and step 2 are the steps for preparing a latent curing agent.

The term " latent curing agent " used in the present invention means a curing agent which does not react with an epoxy compound until heat is applied, and induces curing with an epoxy resin after applying heat.

In particular, the latent curing agent to be produced in the present invention includes a core containing a curing agent and a shell containing a polymer surrounding the core. Accordingly, even if the latent curing agent according to the present invention is mixed with an acrylic compound, the reaction is blocked by the shell until heat is applied, and after the heat is applied, the shell is melted and reacted to induce curing.

In order to produce the above-mentioned core / shell type latent curing agent, an electrospray double feed nozzle is used in the present invention. The term " electrospray " used in the present invention means that a voltage is applied to a substance to be injected and injected. The term 'dual supply nozzle' used in the present invention means a nozzle through which the material to be sprayed is sprayed. In the present invention, the nozzle includes an inner tube and an outer tube surrounding the inner tube.

FIG. 1 schematically shows an electric spraying double supply nozzle used in the present invention. 1 shows a cross section of an electrospray double feed nozzle, which comprises an inner tube 1 and an outer tube 2 in the form of an envelope as shown in FIG. The different compositions are sprayed simultaneously through the inner tube and the outer tube, respectively.

Specifically, the present invention includes a step (step 1) of supplying a curing agent composition to an inner tube of the electrospraying double feed nozzle and supplying the polymer composition to an outer tube of the electrospray double feed nozzle.

The curing agent composition is supplied to the inner tube of the electrospray double feed nozzle, and then sprayed as in step 2 below to form a core of the latent curing agent to be produced in the present invention. In addition, the polymer composition is supplied to the outer tube of the electrospray double feed nozzle, and then sprayed as in step 2 below to form a shell of the latent curing agent to be produced in the present invention.

At this time, the supply rate of the curing agent composition supplied to the inner pipe of the electric injection double supply nozzle and the supply rate of the polymer composition supplied to the external pipe of the electric injection double supply nozzle have to be taken into consideration. The respective feed rates are related to the amount of each material injected from the inner tube and the outer tube of the electrospray double feed nozzle, and the ratio of the feed rate thereof can be adjusted to produce a core / shell type latent curing agent have.

Specifically, the feed rate (mL / h) of the curing agent composition and the feed rate (mL / h) of the polymer composition are preferably 1: 5 to 1:80, more preferably 1:16 to 1:20 to be. If the feed rate ratio is more than 1:80, it is not formed in a core / shell form but in a fiber form, or the thickness of the shell becomes too high. In addition, when the feed rate ratio is less than 1: 5, the shell does not sufficiently surround the core or the thickness of the shell becomes too thin. The supply rate of the curing agent composition is preferably 0.01 to 0.15 mL / h, more preferably 0.03 to 0.06 mL / h. The feed rate of the polymer composition is preferably 0.3 to 0.7 mL / h.

The diameters of the inner tube and the outer tube of the electrospray double feed nozzle are related to the diameter of the core of the latent curing agent and the thickness of the shell to be produced in the present invention, respectively. Preferably, the diameter of the inner tube of the electrospray double feed nozzle is from 10 gauge to 40 gauge. Also preferably, the diameter of the outer tube of the electrospray double feed nozzle is 5 gauge to 60 gauge larger than the diameter of the inner tube.

On the other hand, the curing agent contained in the curing agent composition supplied to the inner tube of the electric spraying double supply nozzle is not particularly limited as long as it is a curing agent used for curing a thermosetting resin such as an epoxy resin. Preferably, the curing agent is selected from the group consisting of 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, ethylenediamine, butanediamine, hexamethylenediamine Diethylenetriamine, malonic acid dihydrazide, 1,3-bis (hydrazinocarbonyl) -5-isopropylhydantoin, 1,8-diazabicyclo [ Cyclo [5.4.0] undeca-7-ene, 2,4,6-tris (dimethylaminomethyl) phenol, and 2-dimethylaminophenol.

In addition, the curing agent composition may further include PEG (polyethylene glycol), PVDF (polyvinylidene fluoride), etc. for the stability of the curing agent.

As the curing agent composition, a lipophilic or hydrophilic polymer may be selected. When the hydrophilic polymer is used in the curing agent composition, a lipophilic polymer is used as the polymer of the shell, and when the lipophilic polymer is used in the curing agent composition, the shell polymer may be a hydrophilic polymer.

Also, as the solvent of the curing agent composition, the flowability of each material is controlled by using acetone, ethyl acetate, DMF, or a mixed solvent thereof to facilitate the production of the latent curing agent.

The polymer contained in the polymer composition supplied to the outer tube of the electrospray double feed nozzle is not particularly limited as long as it is a polymer used in a core / shell type latent curing agent. Preferably, PVDF (polyvinylidene fluoride), PCL (polycaprolactone), and PEG (polyethylene glycol) may be used as the polymer. Preferably, PVDF can be used. As the solvent for the polymer composition, acetone, ethyl acetate, DMF, or a mixed solvent thereof may be used.

Meanwhile, the present invention includes a step (step 2) of spraying the hardener composition and the polymer composition onto the substrate from the electrospray double feed nozzle following step 1 described above.

A voltage is applied between the electrostatic spraying double supply nozzle and the substrate so that the injected composition moves to the substrate. Also, the curing agent composition and the polymer composition are injected in a predetermined direction from the electrospraying double feed nozzle by the movement path, thereby effectively forming a core / shell shape.

On the other hand, the applied voltage and the distance between the electric double jet nozzle and the substrate affect the formation of the core / shell form of the latent curing agent to be produced in the present invention. Preferably, the distance between the electrospray double feed nozzle and the substrate is 0.2 m to 2 m, more preferably 0.25 to 0.5 m, and most preferably 0.3 m. The voltage applied to the electrospray double feed nozzle and the substrate is 1 kV to 50 kV, more preferably 3 kV to 10 kV. Depending on the voltage, the dispersibility of the shell, ie the injection radius of the dispersed polymer shell, varies and the distance of the substrate also affects it. Also, depending on the magnitude of the applied voltage, whether the polymer sprayed from the nozzle is sprayed or spunning is also determined.

According to the step 2, the latent curing agent to be produced in the present invention may be sprayed on the substrate, and may further include a step of drying if necessary. The drying is for removing the solvent contained in the curing agent composition and the polymer composition, and there is no particular limitation on the method. For example, the drying may be carried out by leaving it on the substrate for a predetermined time or by vacuum drying, It is also possible.

The present invention can also be carried out by a continuous method, for example, a method of continuously supplying the curing agent composition and the polymer composition to the electrospray double feed nozzle and continuously recovering the latent curing agent formed on the substrate is also possible .

In the latent curing agent to be produced, it is preferable that the diameter of the core is 10 탆 to 15 탆, and the thickness of the shell is 5 탆 to 10 탆.

Step 3

Step 3 is a step of preparing a composition for forming a pressure-sensitive adhesive sheet by mixing the previously prepared latent curing agent and an acrylic compound.

The latent curing agent is preferably contained in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the acrylic compound.

Examples of the acrylic compound include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, acrylic acid, isobornyl acrylate, lauryl methacrylate, glycidyl methacrylate, isobutyl methacrylate and isooctyl acrylate May be used. Further, it is preferable to use at least two kinds of acrylic compounds, and in this case, it is preferable to use at least one compound having an epoxy group.

In addition, the acrylic compound is preferably partially polymerized if necessary, and light polymerization can be further performed for this purpose. When photopolymerization is carried out, hardening does not proceed since there is no influence on the shell of the latent curing agent, and it is possible to have a viscosity suitable for forming the adhesive sheet by partial polymerization.

For photopolymerization, the composition for forming a pressure-sensitive adhesive sheet may include an initiator, and examples thereof include benzoin ethers (e.g., benzoyl methyl ether or benzoin isopropyl ether), substituted benzoin ethers (e.g., Methyl ether), substituted acetophenones (e.g., 2,2-diethoxyacetophenone, and 2,2-dimethoxy-2-phenylacetophenone), substituted alpha-ketols -Methyl-2-hydroxypropiophenone), and a photoactive oxime (for example, 1-phenyl-1,1-propandion-2- (O-ethoxycarbonyl) oxime). Commercially available initiators include, for example, Irgacure series initiators available from Ciba Specialty Chemicals.

The initiator is preferably used in an effective amount of an initiator to polymerize the precursor upon exposure to a suitable light source for a desired exposure time. For example, the photoinitiator may be used in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the acrylic compound.

Step 4

Step 4 is a step of applying the composition for forming a pressure-sensitive adhesive sheet prepared in step 3 onto a film to produce a pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet preferably has a thickness of 10 탆 to 100 탆. Further, the method may further include a step of coating the film and drying the film.

On the other hand, since the pressure sensitive adhesive sheet prepared as described above contains a latent curing agent, the latent curing agent does not specifically react at the room temperature, for example, until the heat is applied, and when the heat is applied, And cured. Therefore, the curing of the pressure-sensitive adhesive sheet does not proceed until the user applies heat, so that it is convenient to circulate, store, and use, and heat can be applied only at the time of final curing after completion of the operation using the pressure-sensitive adhesive sheet. There is a remarkably improved effect.

As described above, the method for producing a pressure-sensitive adhesive sheet according to the present invention can suppress the curing until the pressure-sensitive adhesive sheet is applied to a component, but can be cured when the temperature is raised by heating after applying the pressure- It is possible to manufacture a pressure-sensitive adhesive sheet having an excellent adhesive property, and the use convenience is remarkably improved.

1 is a cross-sectional view of an electrospray double feed nozzle used in the present invention.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

Manufacturing example  1: Preparation of latent curing agent

1) Preparation of curing agent composition - Composition for forming core

PEG and 2-Phenylimidazole (2-PZ) were added to DMF / acetone mixed solvent (60:40) to be 3 wt% and 10 wt%, respectively, to prepare a curing agent composition.

2) Preparation of polymer composition - composition for shell formation

PVDF was added to a DMF / acetone mixed solvent (40:60) so as to be 1.5% by weight, to prepare a polymer composition.

3) Preparation of latent hardener

A latent curing agent was prepared using an electrospray double feed nozzle having an inner diameter of 17 gauge and an outer diameter of 23 gauge. Specifically, the prepared curing agent composition was supplied to the inner tube of the electric spraying double supply nozzle, and the outer tube of the electric spraying double supply nozzle was supplied with the prepared polymer composition. The feeding rate was set at 0.06 mL / h , And the polymer composition was fed at a rate of 0.5 mL / h for 30 seconds to prepare a latent curing agent. At this time, the temperature was 26 ° C, the humidity was 22%, the voltage applied to the electrospray double feed nozzle and the substrate was 4.8 kV, and the distance between the electrospray double feed nozzle and the substrate was maintained at 0.3 m.

4) Curing experiment

The following experiment was conducted to confirm that curing was inhibited when mixed with an epoxy resin by the shell of the latent curing agent prepared above.

For comparison, a composition was prepared by mixing 100 parts by weight of an epoxy resin (YD-128, Kukdo Chemical) and 4 parts by weight of 2-phenylimidazole (2-PZ). Further, a composition in which 100 parts by weight of an epoxy resin (YD-128, Kukdo Chemical Co., Ltd.) and the latent curing agent prepared in the above Example were mixed was prepared. Each time was measured at room temperature and at 60 占 폚. As a result, when latent curing was used, it was not cured at 15 days at room temperature, otherwise curing was observed after 18 hours.

Manufacturing example  2: Preparation of composition for forming pressure-sensitive adhesive sheet

49 parts by weight of ethylhexyl acrylate, 18 parts by weight of 2-hydroxyethyl acrylate, 4 parts by weight of acrylic acid, 19 parts by weight of isobornyl acrylate, 10 parts by weight of lauryl methacrylate, and 0.1 part by weight of Micure of Miwon specialty chemicals CP-4 were mixed. The mixture was partially photopolymerized to a viscosity of 3800 CPS using a black light lamp having a wavelength of the UV-A region to prepare a syrup capable of forming a pressure-sensitive adhesive sheet.

Example  And Comparative Example

A pressure-sensitive adhesive sheet was prepared using the latent curing agent and the composition for forming a pressure-sensitive adhesive sheet prepared in Preparation Examples 1 and 2. Specifically, the composition was prepared with the composition shown in Table 1, and then coated on the releasing-treated film surface and dried to prepare a pressure-sensitive adhesive sheet having a thickness of 35 탆. The numerical values in Table 1 below mean " parts by weight ".

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Composition for forming a pressure-sensitive adhesive sheet (Production Example 2) 86 86 86 86 86 86 Glycidyl methacrylate 14 14 14 14 14 14 Hexane-1,6-diol diacrylate (crosslinking agent) 0.1 0.1 0.1 0.1 0.1 0.1 The latent curing agent (Preparation Example 1) 0.42 ¹⁾ 0.25 ²⁾ 0.125 ³⁾ - - - 2-phenylimidazole - - - 0.07 0.04 0.02 1) Content of 2-phenylimidazole: 0.07 part by weight
2) Content of 2-phenylimidazole: 0.04 parts by weight
3) Content of 2-phenylimidazole: 0.02 parts by weight

Experimental Example

The pressure-sensitive adhesive sheet thus prepared was cut into a width of 10 mm, and a PI film having a thickness of 50 탆 was attached to the opposite side of the measurement. SUS adherent was pressed and pressed for 1 minute using a 2 kg roller and then pressed with a hot press (160 ° C, 10 bar) for 60 minutes. At room temperature, the peel strength (unit gf) was measured by peeling 180 ° at a rate of 100 mm / min using a universal testing machine (LR5K plus of AMETEK company) , And the results are shown in Table 2 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 1 day 1713 1900 1920 1800 1900 1920 2 days 1762 1800 1950 1250 1450 1950 3 days 1800 1950 1900 1200 1400 1550 4 days 1795 1950 1898 1144 1350 1450 5 days 1875 2100 1900 1284 1400 1500 6 days 1830 1950 1850 1227 1300 1300 7 days 1850 2015 1950 1100 1400 1320 8 days 1912 2200 1980 1005 1380 1200 9th 1820 1900 1920 1070 1325 1170 10 days 1900 2000 1900 1100 1375 1150

As described above, the adhesive force was not changed even after a lapse of time, which means that the curing of the pressure-sensitive adhesive sheet does not proceed until the curing is proceeded by applying heat with the hot press. On the other hand, in the case of the comparative example, it was confirmed that the adhesive strength gradually decreased with time, which means that the curing proceeds continuously over time.

Claims (9)

1) supplying a curing agent composition to an inner tube of an electrospray double feed nozzle and supplying a polymer composition comprising PVDF (polyvinylidene fluoride) to an outer tube of an electrospray double feed nozzle; And
2) spraying the hardener composition and the polymer composition onto the substrate from the electrospray double feed nozzle to produce a latent curing agent;
3) mixing the latent curing agent and the acrylic compound to prepare a composition for forming a pressure-sensitive adhesive sheet; And
4) applying the composition for forming a pressure-sensitive adhesive sheet on a film,
Wherein the pressure-sensitive adhesive sheet is a sheet.
The method according to claim 1,
The feed rate of the curing agent composition and the feed rate of the polymer composition are 1: 5 to 1:80,
Wherein the distance between the electrospraying double feed nozzle and the substrate is 0.2 m to 2 m,
Wherein the voltage applied to the electrospray dual feed nozzle and the substrate is between 1 kV and 50 kV,
Gt;
The method according to claim 1,
The curing agent composition may be selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, ethylenediamine, butanediamine, hexamethylenediamine, octanediamine, diethylenetriamine, Diethylenetriamine, malonic acid dihydrazide, 1,3-bis (hydrazinocarbonyl) -5-isopropylhydantoin, 1,8-diazabicyclo [5.4.0] undeca-7- Ene, 2,4,6-tris (dimethylaminomethyl) phenol, or 2-dimethylaminophenol.
Gt;
delete The method according to claim 1,
Characterized in that the latent curing agent comprises a core comprising the curing agent and a shell surrounding the core and comprising the polymer.
Gt;
6. The method of claim 5,
Characterized in that the diameter of the core is 10 [mu] m to 15 [mu] m and the thickness of the shell is 5 [mu] m to 10 [
Gt;
The method according to claim 1,
The acrylic compound may be at least one selected from the group consisting of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, acrylic acid, isobornyl acrylate, lauryl methacrylate, glycidyl methacrylate, isobutyl methacrylate, ≪ RTI ID = 0.0 > and / or < / RTI >
Gt;
The method according to claim 1,
Characterized in that the pressure-sensitive adhesive sheet has a thickness of 10 탆 to 100 탆.
Gt;
A pressure-sensitive adhesive sheet produced by the manufacturing method according to any one of claims 1 to 3 and 5 to 8.

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