JP2010194512A - Method for manufacturing release film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method that can solve such a problem that the peel force of an obtained release film is fluctuated under various conditions such as processing velocity, temperature, humidity, and drying velocity, and can stably manufacture the release film adjusted to various peel forces in a process that applies a coating liquid containing a releasing agent to the film and performs drying thereon. <P>SOLUTION: The method for manufacturing a release film includes applying a silicone-based compound dissolved in a solvent containing xylene to one side of the film and drying it. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing a release film.

  Polyester films represented by polyethylene terephthalate and polyethylene naphthalate have excellent mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, etc. It is used in applications. However, as the use diversifies, it is required to adjust to various peeling forces. It is known that the release force of a release film can be adjusted to an arbitrary release force by mixing a heavy release component and a light release component. However, it is difficult to obtain a release film having a stable release force because the release force of the release film fluctuates only by slightly different conditions such as processing speed, temperature and humidity, and drying speed in the coating and drying process. is there.

JP 10-44350 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is to apply a coating solution containing a release agent to a film and dry it, such as processing speed, temperature, humidity, and drying speed. To provide a method capable of solving the problem that the peeling force of the obtained release film varies depending on various conditions, and stably producing a release film adjusted to various peeling forces. It is in.

  As a result of intensive studies in view of the above problems, the present inventor has found that the above problems can be easily solved by adopting a specific manufacturing method, and has completed the present invention.

  That is, the gist of the present invention resides in a method for producing a release film, wherein a silicone compound dissolved in a solvent containing xylene is applied to one side of the film and then dried.

Hereinafter, the present invention will be described in detail.
The polyester film referred to in the present invention is a film which is melt-extruded from an extrusion die, and is subjected to stretching and heat treatment as necessary after cooling a molten polyester sheet extruded by a so-called extrusion method.

  Further, the polyester film constituting the polyester film of the present invention may be a single layer structure or a multilayer structure, and may be a four-layer or a multilayer unless the gist of the present invention is exceeded other than the two-layer or three-layer structure. It may be a multilayer having more than that, and is not particularly limited.

  The polyester constituting the film of the present invention is obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like. The polyester used may be a homopolyester or a copolyester. In the case of a copolyester, it may be a copolymer containing 30 mol% or less of the third component. The dicarboxylic acid component of the copolymerized polyester is selected from isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid and oxycarboxylic acid (for example, P-oxybenzoic acid). The glycol component includes one or more selected from ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like.

  In the polyester obtained by the present invention, a weathering agent, a light-proofing agent, an antistatic agent, a lubricant, a light-shielding agent, an antioxidant, a fluorescent whitening agent, a matting agent, and a heat-stabilizing agent as long as the gist of the invention is not impaired You may mix | blend an agent and coloring agents, such as dye and a pigment.

  Examples of the particles to be blended in the film include silicon oxide, alumina, calcium carbonate, kaolin, titanium oxide, and crosslinked polymer fine powder as described in JP-B-59-5216. These particles may be used alone or in combination of two or more components. The content of the film layer to which these particles are added is usually 1% by weight or less, preferably 0.01 to 1% by weight, and more preferably 0.02 to 0.6% by weight. When the content of the particles is small, the film surface is flattened, and in the film production process, the surface is liable to be scratched and the winding property tends to be inferior. Further, when the content of the particles exceeds 1% by weight, the degree of roughening of the film surface becomes too large, and the transparency may be impaired.

  The average particle size of the particles contained in the polyester film is 0.02 to 2 μm, preferably 0.1 to 1.8 μm, more preferably 0.2 to 1.6 μm. When the particle size is less than 0.02 μm, the film surface becomes flat and the winding properties in the film production process tend to be inferior. When the particle diameter exceeds 2 μm, it may be difficult to cope with the formation of a flat resin sheet. On the other hand, in order to improve the transparency of the film, when a laminated film of two or more layers is used, a method of blending particles only in the surface layer is also preferably employed. The surface layer in this case is at least one of the front and back layers, and of course, particles can be blended in both the front and back layers.

  In the present invention, the method of blending the particles with the polyester is not particularly limited, and a known method can be adopted. For example, it can be added at any stage for producing the polyester, but it is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or before the start of the polycondensation reaction after completion of the transesterification reaction. The condensation reaction may proceed. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a method of blending dried particles and a polyester raw material using a kneading extruder Etc.

  The polyester may be chipped after melt polymerization, and further subjected to solid phase polymerization as necessary under heating under reduced pressure or in an inert gas stream such as nitrogen. The intrinsic viscosity of the obtained polyester is preferably 0.40 dl / g or more, and preferably 0.40 to 0.90 dl / g.

  The total thickness of the film of the present invention is not particularly limited as long as it can be formed as a film, but is usually 9 to 350 μm, preferably 12 to 250 μm, and more preferably 25 to 188 μm. is there.

  The intrinsic viscosity of the polyester used in the present invention is usually in the range of 0.40 to 0.90, preferably 0.45 to 0.80, and more preferably 0.50 to 0.70. When the intrinsic viscosity is less than 0.40, the mechanical strength of the film tends to be weakened. When the intrinsic viscosity is more than 0.90, the melt viscosity becomes high, the load on the extruder is increased, and the production cost is increased. Problems may occur.

  In the present invention, it is necessary to apply a release coating film on at least one surface of the polyester film using a coating solution in which a silicone compound is dissolved in a solvent containing xylene.

  Moreover, it is preferable that the release layer which comprises the release film in this invention contains a curable silicone resin in order to make mold release property favorable. A type having a curable silicone resin as a main component may be used, or a modified silicone type by graft polymerization with an organic resin such as a urethane resin, an epoxy resin, or an alkyd resin may be used.

  As the type of the curable silicone resin, any of the curing reaction types such as an addition type, a condensation type, an ultraviolet curable type, an electron beam curable type, and a solventless type can be used. Specific examples include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X manufactured by Shin-Etsu Chemical Co., Ltd. -62-1387, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, X-62 -7213, GE Toshiba Silicones Co., Ltd. YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430, TPR6600, TPR6604, TPR6605, SM3200, SM3030, Toray Da DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210, SRX357, SRX211, SD7220, LTC750A, LTC760A, SP7259, BY24-468C, SP7248S, BY24-452, SP7265S, SP7265S , LTC1000M, LTC1050L, SYLOFF7900, SYLOFF7198, SYLOFF22A, and the like. Further, a release control agent may be used in combination to adjust the release property of the release layer.

  In the present invention, conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating and the like can be used as a method for providing a release layer on the polyester film. Regarding the coating method, there is a description example in “Coating method” published by Yasuharu Harasaki in 1979.

  As the solvent to be used, hydrocarbons such as toluene, ketones, and various alcohols can be used.

  The xylene content in the solvent is preferably 50% by weight or less, and more preferably in the range of 1 to 20% by weight. If the xylene content exceeds 50% by weight, the release layer tends to be insufficiently cured. Conversely, when the xylene content is small, the effect of stabilizing the peeling force is reduced.

  In the present invention, the coating liquid is applied to at least one surface of the film and dried to apply a release layer. As this film, an unstretched film; an unstretched film is a longitudinal direction (longitudinal direction) or a transverse direction. A uniaxially stretched film stretched in any one of (width direction); a biaxially stretched film obtained by sequentially stretching a uniaxially stretched film in the longitudinal direction or the transverse direction in the transverse direction or the longitudinal direction; or an unstretched film in the longitudinal direction and the transverse direction Biaxially stretched film simultaneously stretched in two directions; Multistage stretched film obtained by further stretching biaxially stretched film in the machine direction and / or transverse direction; Biaxially stretched and / or heat relaxed biaxially stretched film or multistage stretched film Any of the heat-treated stretched films may be used.

  The thickness of the film is preferably 10 to 1000 μm for an unstretched film, 2 to 500 μm for a uniaxially stretched film, 1 to 300 μm, particularly preferably 2 to 150 μm for a biaxially stretched film, a multistage stretched film and a biaxially stretched heat-treated film.

  When any of the above films is subjected to corona treatment before the liquid is applied, polar groups are generated on the film surface, and the bonding between the silicone compound and other monomers is promoted, and the film and the release layer This is preferable because of improving the adhesion.

  As a method of applying the coating liquid to the film, any known coating method can be applied, for example, gravure coating method, reverse roll coating method, die coating method, kiss coating method, reverse kiss coating method, offset gravure coating method, Meyer bar coating A method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method and the like can be applied alone or in combination.

  According to the present invention, a release film having a stable peeling force can be provided, and its industrial value is high.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to the following examples. The characteristics in the examples were measured by the following method.

(1) Heat peeling force No. made by Nitto Denko Co., Ltd. cut to 50 mm width on the measurement surface of the sample The surface of the 502 double-sided tape from which the cream-colored release paper has been peeled off is bonded with a rubber roller (2 kg). The sample was cut into a double-sided tape width, heat-treated at 100 ° C. for 1 hour in a hot air circulating thermostat, cooled to room temperature, and then the sample film on the upper chuck and No. on the lower chuck. The 502 tape and the auxiliary plate are fixed together, peeled off in the 180 ° direction at a pulling speed of 300 mm / min, the peeling load is measured, and converted to mN / cm units.

Example 1:
100 parts of curable silicone resin (KS723A manufactured by Shin-Etsu Chemical Co., Ltd.), 25 parts of curable silicone resin (KS723B manufactured by Shin-Etsu Chemical Co., Ltd.), 5 parts of catalyst (PS-3 manufactured by Shin-Etsu Chemical Co., Ltd.), toluene / Coating solution consisting of 3000 parts of methyl ethyl ketone mixed solvent (1: 1) and 100 parts of xylene is applied with a Meyer bar, heat treated at 150 ° C. for 15 seconds, and cured to a coating thickness of 0.1 μm after curing. A release film was obtained by forming a silicone resin film. When the release force of the release film obtained by repeating the same operation 9 times was measured, the average heat release force was 65 mN / cm, the standard deviation was 3, and a release film having a stable release force was obtained. I was able to get it.

Example 2:
100 parts of curable silicone resin (KS723A manufactured by Shin-Etsu Chemical Co., Ltd.), 25 parts of curable silicone resin (KS723B manufactured by Shin-Etsu Chemical Co., Ltd.), 5 parts of catalyst (PS-3 manufactured by Shin-Etsu Chemical Co., Ltd.), toluene / Coating solution consisting of 2600 parts of methyl ethyl ketone mixed solvent (1: 1) and 500 parts of xylene is applied with a Meyer bar, heat-treated at 150 ° C. for 15 seconds, and cured to a coating thickness of 0.1 μm after curing. A release film was obtained by forming a silicone resin film. When the release force of the release film obtained by repeating the same operation 9 times was measured, the average heat release force was 65 mN / cm, the standard deviation was 3, and a release film having a stable release force was obtained. I was able to get it.
Comparative example: 1
A release film was obtained in the same manner as in Example 1 except that a coating solution to which xylene was not added was used. When the peel force of the release film obtained by repeating the same operation 9 times was measured, the average heat peel force was 65 mN / cm, but the standard deviation was 11 and the release force had a stable peel force. A film could not be obtained.

  The release film obtained by the present invention can be suitably used in various applications where a stable peeling force is required.

Claims (1)

A method for producing a release film, wherein a silicone compound dissolved in a solvent containing xylene is applied to one side of a film and then dried.