KR20140097897A - Pressure-sensitive adhesive film - Google Patents

Abstract

The present invention relates to an adhesive film comprising a base material film, an adhesive layer, and a release layer laminated sequentially, the adhesive film including the adhesive layer composed of an adhesive composition comprising acryl amide. The adhesive film according to the present invention has high acid resistance for an etching solution which is strong acid, while controlling an influence on an adhesive layer of a plasticizer to maintain adhesive properties of the adhesive layer, and is able to be manufactured with the low cost and high yield, to be used as a protective film for protecting a part not desired to be etched during etching of a glass substrate.

Description

{PRESSURE-SENSITIVE ADHESIVE FILM}

The present invention relates to a pressure-sensitive adhesive film, and more particularly to a pressure-sensitive adhesive protective film for surface etching of a glass substrate, which has an acid resistance capable of protecting portions other than a surface to be etched when etching a surface of a glass substrate.

A glass substrate or a glass composition used for a display device such as a liquid crystal display device (LCD), a plasma display device (PDP), an organic light emitting diode (OLED), ornamental or advertising purposes requires a process for thinning, Dry or wet etching methods have been used.

Particularly, in the case of a glass substrate for a display device, it is generalized that the thickness and thickness of the display device are increased and the thickness of the glass substrate is reduced by etching the glass substrate. Wet etching methods have been used. In such a wet etching process, a portion other than the portion to be etched needs to be stably protected from a strong acid etchant, and a protective film is used for this purpose.

As the protective film, an adhesive film in which an adhesive layer is formed on one surface of a base film is used. At this time, a synthetic resin film such as a polyvinyl chloride film is often used as a base film of the adhesive sheet. Plasticizers are generally added to the synthetic resin film for the purpose of imparting flexibility and elasticity. However, when a certain period of time elapses after the production of the adhesive film, the plasticizer contained in the base film is transferred to the adhesive layer, and the adhesive property of the adhesive layer is deteriorated due to the plasticizer migration phenomenon.

Accordingly, various methods have been used to prevent the plasticizer migration phenomenon as described above and to maintain the adhesive property of the pressure-sensitive adhesive film. Among them, Korean Patent Laid-Open Nos. 2010-0008580 and 2005-0103990 disclose that a plasticizer migration preventive layer (back treated layer) is separately formed between a base film and an adhesive layer to prevent migration of the plasticizer to maintain the adhesive property of the adhesive layer However, this method has a problem that the production cost of the pressure-sensitive adhesive film is increased and the yield at the time of producing the pressure-sensitive adhesive film is lowered due to the formation of the separate barrier layer.

Therefore, there is a demand for development of an adhesive film which is high in acid resistance to a strong acid etching solution and which can suppress the influence of the plasticizer on the adhesive layer to maintain the adhesive property of the adhesive layer, and can be produced at low cost and high yield.

Accordingly, an object of the present invention is to provide an adhesive film which is high in acid resistance to a strong acid etchant, has an excellent impact resistance to the adhesive layer of the plasticizer, maintains the adhesive property of the adhesive layer, and can be produced at low cost and high yield.

In order to achieve the above object, the present invention provides an adhesive film comprising a base film, an adhesive layer, and a release film sequentially laminated, wherein the adhesive layer comprises an acrylamide-containing adhesive composition .

The pressure-sensitive adhesive film of the present invention has high acid resistance to a strong acid etching solution, suppresses the influence of the plasticizer on the pressure-sensitive adhesive layer, maintains the adhesive property of the pressure-sensitive adhesive layer, and can be manufactured at low cost and high yield. Can be advantageously used as a protective film for protecting unwanted parts.

1 is a view schematically showing a cross section of an adhesive film according to an embodiment of the present invention.
2 is a diagram schematically showing a cross section of an adhesive film according to another embodiment of the present invention.

The adhesive film of the present invention comprises a base film, a pressure-sensitive adhesive layer, and a release film in the form of a laminate, and the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive composition comprising acrylamide.

The base film may be a polyvinyl chloride (PVC) film, a polyethylene (PE) film, a polyethylene terephthalate (PET) film, a polypropylene (PP) film, or a polycarbonate (PC) Layer composite film.

The thickness of the base film is not particularly limited, but may be 50 to 200 占 퐉, preferably 50 to 100 占 퐉. When the thickness of the base film is 50 탆 or less, it is difficult to ensure sufficient acid resistance. When the thickness is 200 탆 or more, the flexibility is poor and the handling property is deteriorated.

When the base film is composed of a multilayer composite film of two layers, an adhesive layer is formed on one surface of the first base film, an adhesive layer is formed on the other surface, and the second base film is laminated on the adhesive layer have.

As the first base film and the second base film, an exemplary film of the base film may be used. Preferably, the first base film is a PVC film, and the second base film may be a PE film or a PET film .

Examples of the adhesive constituting the adhesive layer include acrylic, urethane, epoxy, ester and silicone adhesives or mixtures thereof, but a pressure-sensitive adhesive composition constituting the adhesive layer of the present invention may also be used.

The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film of the present invention may be composed of an acrylic monomer and a carboxyl group-containing unsaturated monomer.

In the pressure-sensitive adhesive film of the present invention, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer contains acrylamide, and the pressure-sensitive adhesive composition may further include a xylene diisocyanate (XDI) -based curing agent.

The pressure-sensitive adhesive composition may comprise at least one of the acrylic monomer and the carboxyl group-containing unsaturated monomer, and specific examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (Meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, ethylhexyl (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, , Glycerol (meth) acrylate, methyl? -Hydroxymethylacrylate, ethyl? -Hydroxymethyl acrylate, propyl? -Hydroxymethylacrylate, butyl? (Meth) acrylate, methoxytriethyleneglycol (meth) acrylate, methoxytriethyleneglycol (meth) acrylate, methoxytriethyleneglycol (meth) acrylate, 2-methoxyethyl (Meth) acrylate, tetrafluoropropyl (meth) acrylate, 1,1,1,3,3,3-hexafluoroisopropyl (meth) acrylate, (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (Meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate and mixtures thereof, and preferably methyl (meth) acrylate, butylAnd specific examples of the carboxyl group-containing unsaturated monomer include acrylic acid, methacrylic acid, 2- (meth) acryloyloxyacetic acid, 3- (meth) acryloyloxypropyl acid, 4- Methacryloyloxybutyric acid, acrylic acid diester, itaconic acid, maleic acid, maleic anhydride and mixtures thereof, and preferably methacrylic acid, acrylic acid and mixtures thereof.

When the pressure sensitive adhesive layer is formed of only the acrylic monomer and the unsaturated monomer containing a carboxyl group, if the plasticizer added to the base film is transferred to the pressure sensitive adhesive layer, the pressure sensitive adhesive layer is softened by the plasticizer, There is a problem that the pressure-sensitive adhesive film according to the present invention contains the acrylamide in the pressure-sensitive adhesive composition, because the internal stress is lowered, thereby causing the pressure-sensitive adhesive layer to be transferred onto the surface of the adherend .

The acrylamide contained in the pressure-sensitive adhesive composition has high glass transition temperature and high cohesion strength, so that deterioration of the adhesive property of the pressure-sensitive adhesive layer caused by the migration of the plasticizer added to the base film to the pressure-sensitive adhesive layer can be prevented.

Specific examples of the acrylamide compound include acrylamide (AAm), N-methyl acrylamide (n-MAAm), diacetone acrylamide (DAAm) and mixtures thereof. Preferably, the glass transition temperature Can be high acrylamide (AAm).

The acrylamide may be contained in an amount of 1 to 100 parts by weight, preferably 10 to 80 parts by weight, more preferably 30 to 50 parts by weight, based on 100 parts by weight of the pressure-sensitive adhesive composition. When the content of the acrylamide is less than 10 parts by weight, it is difficult to prevent deterioration of the adhesive property due to the plasticizer migration. When the amount of the acrylamide is more than 100 parts by weight, the hardness of the adhesive layer becomes too high.

When the xylene diisocyanate curing agent is contained in the pressure-sensitive adhesive composition, the post-curing time of the pressure-sensitive adhesive layer can be shortened at the time of forming the pressure-sensitive adhesive layer.

The xylene diisocyanate curing agent may be added in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition. When the content of the xylylene diisocyanate curing agent is 0.1 parts by weight or less, the pressure-sensitive adhesive layer is not cured properly. If the content of the curing agent is 5.0 parts by weight or more, the adhesive property is deteriorated by the residual curing agent.

The adhesive strength of the adhesive layer may be 30 to 100 gf / inch, preferably 40 to 80 gf / inch. When the adhesive force is 30 gf / inch or less, penetration of the etchant frequently occurs. When the adhesive force is 100 gf / inch or more, it is difficult to remove the protective film after etching, which is not preferable.

The adhesive layer may be 1 to 50 mu m, preferably 5 to 30 mu m, more preferably 10 to 20 mu m.

The release film may be a plastic film such as polyethylene terephthalate or polycarbonate (PC) or the like, and the surface of the release film may be releasably coated with silicon.

The thickness of the release film may be 10 to 250 占 퐉, preferably 20 to 180 占 퐉, more preferably 20 to 125 占 퐉.

Hereinafter, the adhesive film of the present invention will be described in more detail with reference to the drawings, but the drawings are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

1 is a schematic view showing a cross section of an adhesive film according to an embodiment of the present invention.

1, an adhesive film according to an exemplary embodiment of the present invention includes an adhesive layer 20 formed on one surface of a base film 10 and an adhesive layer 20 contacting the base film 10 of the adhesive layer 20 And the silicone treated release film 30 may be located on the other surface. As described above, the adhesive film of the present invention includes the base film 10, the adhesive layer 20, and the release film 30, and the base film 10, the adhesive layer 20, and the release film 30 They may be sequentially stacked.

2 is a schematic view showing a cross section of a pressure-sensitive adhesive film according to another embodiment of the present invention.

2, an adhesive film 20 according to an embodiment of the present invention includes an adhesive layer 20 formed on one surface of a base film 10 and a base film 20 contacting the base film 10 of the adhesive layer 20 The adhesive layer 40 is formed on the other surface of the base film 10 on which the adhesive layer 20 is not formed and the adhesive layer 40 is formed on the other surface of the base film 10 on which the adhesive layer 20 is not formed, The second base film 50 may be laminated so that the base film layer may have a multilayered composite film form.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

Example  One

, 0.2 part by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator was added to 100 parts by weight of butyl acrylate (BA), 30 parts by weight of acrylamide (AM), 6.5 parts by weight of methacrylic acid (MA) and 1 part by weight of acrylic acid Were mixed and heat-polymerized to prepare a pressure-sensitive adhesive composition. 0.75 part by weight of an XDI curing agent (SAVINOL Hardener K-341, Saidensha) was added to the pressure-sensitive adhesive composition, and the silicone-treated release film having a thickness of 38 탆 was coated to a dry thickness of 15 탆. The film was dried at a drying temperature of 100 占 폚 for 3 minutes and then transferred to a PVC base film having a thickness of 80 占 퐉 to prepare a protective film.

Example  2

An adhesive film was produced in the same manner as in Example 1, except that the amount of acrylamide was changed to 50 parts by weight.

Example  3

A pressure-sensitive adhesive film was produced in the same manner as in Example 1, except that the amount of acrylamide was changed to 80 parts by weight.

Example  4

An adhesive film was produced in the same manner as in Example 1, except that the amount of acrylamide was changed to 100 parts by weight.

Comparative Example  One

A pressure-sensitive adhesive film was prepared in the same manner as in Example 1, except that 50 parts by weight of acrylamide was used and an HDI curing agent (SAVINOL X-307-187 SK, Saidensha) was used instead of the XDI curing agent.

Comparative Example  2

An adhesive film was produced in the same manner as in Example 1, except that acrylamide was not used.

Experimental Example

The pressure-sensitive adhesive films prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were post-cured at 100 ° C for 72 hours, and then the adhesive force of the post-cured pressure-sensitive adhesive films with time was measured according to the method of JIS Z 0237 And the presence or absence of sticky residue was confirmed.

≪ Evaluation of adhesion &

The pressure-sensitive adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were post-cured at 100 ° C for 72 hours, and then they were formed into a sample having a width of 1 inch. Round trip. After a lapse of 30 minutes from the attachment, the peel force (180 ° peeling, peeling speed: 300 mm / min) was measured using a texture analyzer. After the pressure-sensitive adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were allowed to stand at 60 占 폚 for one week, the peel force was measured in the same manner as described above. The peeling force was measured three times or more and the average value was obtained. The results are shown in Table 1.

<Confirmation of sticky residue>

After the adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were allowed to stand at 60 ° C for one week, it was visually inspected whether adhesive residues were formed in the evaluation of the adhesive force. Thereafter, ), Trace amount of residue (?) And presence of residue (?). The results are also shown in Table 1.

Item Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 adhesiveness
(gf / inch,
Glass substrate,
180 degree peeling) Early 62.2 52.3 44.9 35.1 50.1 70.6 60 ℃ 1 week 58.6 50.2 43.9 34.8 41.6 32.5 Adhesive residue
Whether After 1 week at 60 ° C Visual inspection X X X X Δ O

As can be seen from Table 1, the adhesive films of Examples 1 to 4 according to the present invention retained good adhesion even after being left at 60 ° C for one week, while the adhesive films of Comparative Example 2 containing no acrylamide The adhesive strength decreased to less than half. In addition, since the adhesive film of Comparative Example 1 contained acrylamide, the adhesive force was comparatively small even after a lapse of time compared to Comparative Example 2 which did not include acrylamide. However, the adhesive film of Example 2, In comparison, the curing reaction rate of the HDI-based curing agent was relatively slow, resulting in a decrease in the adhesion after a lapse of time, resulting in adhesive residue. On the other hand, as the content of acrylamide increased, the hardness of the adhesive layer increased and the adhesive strength tended to be lowered.

10: substrate film
20: Adhesive layer
30: Silicone-treated release film
40: adhesive layer
50: second base film

Claims (10)

A pressure-sensitive adhesive film comprising a substrate film, a pressure-sensitive adhesive layer, and a release film in the form of a laminate,
Wherein the adhesive layer is made of a pressure-sensitive adhesive composition comprising acrylamide.
The method according to claim 1,
Wherein the pressure-sensitive adhesive composition comprises a xylene diisocyanate-based curing agent.
The method according to claim 1,
Wherein the pressure-sensitive adhesive composition comprises an acrylic monomer and a carboxyl group-containing unsaturated monomer.
The method of claim 3,
Wherein the acrylic monomer is selected from the group consisting of methyl (meth) acrylate, butyl acrylate, and mixtures thereof, and the carboxyl group-containing unsaturated monomer is selected from the group consisting of methacrylic acid, acrylic acid, and mixtures thereof Lt; / RTI &gt;
The method according to claim 1,
Wherein the pressure-sensitive adhesive composition comprises 1 to 100 parts by weight of the acrylamide based on 100 parts by weight of the pressure-sensitive adhesive composition.
3. The method of claim 2,
Wherein the pressure-sensitive adhesive composition comprises 0.1 to 10 parts by weight of the xylene diisocyanate curing agent based on 100 parts by weight of the pressure-sensitive adhesive composition.
The method according to claim 1,
Wherein the base film is a polyvinyl chloride (PVC) film, a polyethylene (PE) film, a polyethylene terephthalate (PET) film, a polypropylene (PP) film, a polycarbonate (PC) Lt; / RTI &gt;
The method according to claim 1,
Wherein the base film has a thickness of 50 to 200 占 퐉.
The method according to claim 1,
Wherein the adhesive layer has an adhesive strength of 30 to 100 gf / inch.
A laminate comprising the base film and the pressure-sensitive adhesive layer from which the release film has been removed from the pressure-sensitive adhesive film of claim 1.

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