JP3197086B2 - Laminated film and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film and a method for producing the same, and more particularly to a laminated film having excellent release properties and excellent silicone adhesion and durability, and a cross-linked primer comprising the laminated film. The present invention relates to a method for producing a silane coupling agent by suppressing the evaporation of a silane coupling agent when the silane coupling agent is formed to prevent contamination in a process.

[0002]

2. Description of the Related Art It is known that a silane coupling agent is applied to at least one side of a polyester film and crosslinked to form a release film. This silane coupling agent is generally a compound represented by the formula YRSix ₃ . Here, Y is a vinyl group, an epoxy group, an amino group,
R is an alkylene group such as methylene, ethylene and propylene; X is a hydrolyzable group such as a methoxy group and an ethoxy group; and an alkyl group. Specific compounds include, for example, vinyltriethoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl)-
γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like.

[0003] The application of such a silane coupling agent is carried out in a usual primer application step, that is, a step of applying to a biaxially stretched and heat-set polyester film separately from the film production step. However, in this step, it is desirable to apply the coating in a clean atmosphere because dust, refuse, and the like are easily involved.

From this point of view, it has been proposed to apply as a water-based coating solution in a polyester film manufacturing process, particularly on one or both surfaces of the polyester film before the crystal orientation is completed in this process. However, when such a silane coupling agent is applied in a film manufacturing process, a part of the silane coupling agent evaporates in a zone where a crosslinked primer is formed, and adheres and deposits in the film manufacturing process. Problems arise. The deposits sometimes fall on the film and deteriorate the film quality.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a laminated film excellent in mold releasability and easy adhesion of a silicone release layer forming agent, and a method for stably producing the same for a long period of time. Is to provide.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
According to the present invention: At least one side of the polyester film has the following formula I

[0007]

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Wherein X is an alkoxy group, Y is an organic functional group, and Z is at least one selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, an alicyclic group and a polymer chain group.
N is a number from 1 to 90, m is a number from 1 to 90,
(N + m) is a number of 2 to 90, (n + m + p) is 6 to 10
Number of 0. 1. A laminated film characterized by having a layer formed by applying a coating agent containing a high molecular weight silane coupling agent represented by the formula (1): Before the orientation crystallization is completed, at least one surface of the polyester film is coated with a coating material containing a high molecular weight silane coupling agent represented by the above formula I, and then dried, stretched, and heat-set to complete the orientation crystallization. This is achieved by a method for producing a laminated film.

In the present invention, the polyester constituting the film is a crystalline linear saturated polyester produced from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative. Preferable examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, and poly (1,4-cyclohexylene dimethylene terephthalate). Further, a copolymer in which a part of these is substituted with another component, or a mixture with polyalkylene glycol or another resin may be used.

[0010] The polyester film in the present invention comprises:
It can be manufactured by a conventionally known method. For example, the above polyester is dried and then melted, and a die (for example, T die, I
A non-stretched film is extruded from a die or the like onto a cooling drum and rapidly cooled to form an unstretched film. The unstretched film is stretched biaxially, and then heat-fixed. The thickness of the film is not particularly limited, but is preferably 12 to 250 μm. As the polyester film, a film containing no lubricant is preferable from the viewpoint of surface flatness. However, a lubricant such as inorganic fine particles such as calcium carbonate, kaolin, silica and titanium oxide and / or precipitated fine particles of catalyst residue are used for controlling the surface roughness. And a film containing other additives such as an antistatic agent such as sodium dodecylbenzenesulfonate and a color tone adjusting agent.

In the present invention, the high molecular weight silane coupling agent is represented by the following formula I:

[0012]

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Wherein X is an alkoxy group, Y is an organic functional group, and Z is at least one selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, an alicyclic group and a polymer chain group.
N is a number from 1 to 90, m is a number from 1 to 90,
(N + m) is a number of 2 to 90, (n + m + p) is 6 to 10
Number of 0. ] It is a high molecular weight silane coupling agent shown by these.

In the above formula I, X is an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group, and Y is a group containing an epoxy group, a carboxyl group, a hydroxyl group or an amino group. And organic functional groups such as isocyanate group-containing groups. A methoxy group is particularly preferred as the alkoxy group. Z is, for example, an alkyl group such as a methyl group or an ethyl group, for example, a phenyl group,
Aryl and aralkyl groups such as toluyl and benzyl groups, alicyclic groups such as cyclohexyl groups, and, for example, polyethylene glycol, polytetramethylene oxide,
It is at least one group selected from the group consisting of polymer chains such as polyethyleneimine and polyester. n is 1 to
The number 90, m is a number from 1 to 90, (n + m) is a number from 2 to 90, and (n + m + p) is a number from 6 to 100. When n is 0, the crosslinking reaction hardly proceeds, and when m is 0, the adhesion to the film decreases. Further, when (n + m + p) is less than 6, contamination in the process at the time of long-term production occurs, while when it exceeds 100, the adhesion decreases.

In the above formula I,

[0016]

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It should be understood that does not mean block connection, but merely indicates that the sum of the respective units is n, m, p. Therefore, each unit in the above formula I may be bonded at random or may be bonded at a block.

Preferred specific examples of the high molecular weight silane coupling agent represented by the above formula I are shown below.

[0019]

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[0020]

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[0021]

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[0022]

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The compound of the formula II is, for example, trimethyl.
It can be produced by a co-condensation reaction of monomethoxysilane, dimethyl dimethoxysilane, monomethyl trimethoxysilane and γ-glycidoxypropyl dimethoxysilane.

In the present invention, the coating liquid containing a high molecular weight silane coupling agent can be prepared using an organic solvent, but is preferably prepared as an aqueous coating liquid. Examples of the aqueous coating liquid include an aqueous solution, an emulsion, an aqueous dispersion, and an aqueous liquid mixed with an organic solvent.

A necessary amount of a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be added to such a coating liquid, particularly an aqueous liquid.

As such surfactants, those capable of lowering the surface tension of the coating solution to 50 dyne / cm or less, preferably 40 dyne / cm or less, and promoting the wetting of the polyester film are preferable. Oxyethylene alkyl phenyl ether, polyoxyethylene-fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, alkyl sulfosuccinate, quaternary ammonium chloride, alkylamine hydrochloride, etc. Can be mentioned. Further, within the range not to lose the effect of the present invention, for example, other resins, antistatic agents, ultraviolet absorbers, pigments, organic fillers, inorganic fillers such as silica, lubricants, other additives such as blocking inhibitors. Can be mixed.

As a method of providing a primer containing such a high molecular weight silane coupling agent as an essential component, it is preferable to use a method of applying the primer coating solution on a polyester film, drying and thermosetting. The coating may be carried out in a usual primer coating step, that is, in a step of applying to a polyester film which has been biaxially stretched and heat-set separately from the film production step. However, in this step, it is desirable to apply the coating in a clean atmosphere because refuse, dust and the like are easily involved. From such a viewpoint, coating in the polyester film production process is preferable. In particular, it is preferable to apply an aqueous coating solution to one or both surfaces of the polyester film before the crystal orientation is completed in this step. However, when an organic solvent is used, when the primer is applied in the polyester film manufacturing process, the process must be explosion-proof. This is not limited to the case where the film is applied separately from the film manufacturing process.

Here, the polyester film before the completion of the crystal orientation is an unstretched film obtained by heat-melting the polyester to form a film as it is; the unstretched film in the longitudinal direction (longitudinal direction) or the transverse direction (width direction). ) Uniaxially stretched film oriented in either direction; further, stretched and oriented in a low-magnification direction in the longitudinal and transverse directions (finally oriented in the longitudinal or transverse direction to complete orientation crystallization. Biaxially stretched film).

The solid content of the coating solution is usually 30% by weight.
Or less, and more preferably 10% by weight or less. The coating amount is preferably 0.5 to 20 g, more preferably 1 to 10 g, per m ² of the running film. As a coating method, any known coating method can be applied. For example, a kiss coat method, a reverse coat method, a die coat method, a reverse kiss coat method, an offset gravure coat method, a Meyer bar coat method, a roll brush method, a spray coat method, an air knife coat method, an impregnation method, a curtain coat method, or the like alone or It is good to apply in combination.

The polyester film on which the coating liquid has been applied and before the completion of the crystal orientation is dried and led to steps such as stretching and heat setting. For example, a vertically-horizontal stretched polyester film coated with an aqueous liquid is guided to a stenter, and is horizontally stretched and heat-set. During this time, the coating solution is dried and thermally crosslinked.

Conditions for oriented crystallization of the polyester film,
For example, conditions such as stretching and heat setting can be performed under conditions conventionally accumulated in the art.

[0032]

The present invention will be further described below with reference to examples. The characteristics in the examples were measured by the following methods.

1. In-process deposits The production of the polyester laminated film is continuously performed for 1000 hours, and the situation of the deposits in the primer coating forming zone is observed. This situation is evaluated on the following four levels. : None △: Slightly present ×: Present (conventional product) XX: Large amount adhered

2. Using a Meyer bar, a stock solution of PVC resin G-576 made by Nippon Zeon was coated on the surface of the film provided with the cross-linked primer layer of the silane coupling agent at 75 g / cm ² ,
Drying was performed at 110 ° C. for a residence time of 1 minute. No. No. manufactured by Scotch Co. 56 3/4 inch wide tapes were stuck with a metal roller so that air did not enter, and the sample was cut to the width of the stuck tape. Next, the film is peeled in the direction of 180 ° C. by using Tensilon, and the resistance value (g / 18 mm) at this time is indicated. [Evaluation criteria] Upper limit: 70 (g / 18 mm)

3. Back transferability Shin-Etsu Chemical Co., Ltd. product name KS-772, which is a type of adding a platinum catalyst to a mixed solution of polydimethylsiloxane and methylhydrogenpolysiloxane and performing an addition reaction, followed by curing,
It was dissolved in toluene to make a solution having a solid content of 5%. This solution was coated on the above-mentioned primer-coated polyester film at a coating amount of 1 g / m ² , and a drying and curing reaction was performed at 150 ° C. and a residence time of 1 minute to prepare a release film. After superimposing the polyester film on the coated surface and applying a constant load, draw a line with magic ink on the polyester film surface in contact with the coated surface and check the degree of "repelling". [Evaluation criteria] ○: no repelling ×: repelling tendency ××: complete repelling

4. Silicone Adhesion (A) Initial Adhesion Similar to the preparation of a release film for back migration test, the coated surface of the release film immediately after applying and drying the resin is rubbed several times with a fingertip to improve the adhesion of the coating. to see.

(B) Adhesion over time After releasing the release film for one week in an atmosphere of 60 ° C. × 80% RH, the coating surface of the release film was rubbed several times with a fingertip in the same manner as in the evaluation of the initial adhesiveness. Look at the adhesion of the coating. [Evaluation Criteria]: No change 若干: Slightly whitened ×: Almost whitened XX: Silicone layer completely disappeared

[0038]

Examples 1 to 8 and Comparative Examples 1 and 2 Melt extrusion of polyethylene terephthalate (containing 500 ppm of lubricant) having an intrinsic viscosity of 0.65 measured in o-chlorophenol at 35 ° C. onto a rotating cooling drum maintained at 20 ° C. 950μ thick
m, and then stretched 3.5 times in the machine axis direction, using the silane coupling agent and nonionic surfactant (polyoxyethylene nonylphenyl ether) shown in Table 1 and the medium shown in Table 1. The prepared coating solution (4%) was applied to one surface of a uniaxially stretched film by a kiss coat method. Subsequently, stretch 3.9 times in the transverse direction at 105 ° C, and further stretch at 225 ° C.
To obtain a primer-coated polyester film having a thickness of 75 μm. The dry coating amount was 0.05 μm.

Table 2 shows the properties of this film. In addition,
Silane coupling of Comparative Example 1 and Comparative Example 2 in Table 2
Formula A and Formula B described in the type of agent are respectively
Means a silane coupling agent represented by the general formula:

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[0040]

[Table 1]

[0041]

Comparative Example 3 Table 2 shows the results obtained in the same manner as in Example 1 except that the coating material was not applied.

[0042]

[Table 2]

[0043]

According to the present invention, it is possible to provide a laminated film which is excellent in releasing property and easy adhesion of a silicone release layer forming agent, and a method for stably producing the same.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FIB29L 9:00 (56) References JP-A-5-245922 (JP, A) JP-A-64-44796 (JP, A) Kaisho 64-5838 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J ^7/ 04-7/06 B32B 27/00-27/42 B29C 55/00-55/30

Claims (2)

(57) [Claims] 1. A polyester film having the following formula on at least one surface thereof: Wherein X is an alkoxy group, Y is an organic functional group, Z is at least one group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, an alicyclic group and a polymer chain group, and n is The number of 1 to 90, m is the number of 1 to 90, (n + m)
Is a number of 2 to 90, and (n + m + p) is a number of 6 to 100. ] A laminated film characterized by comprising a layer formed by applying a coating agent containing a high-molecular-weight silane coupling agent represented by the formula: 2. The polyester film having the following formula on at least one surface of the polyester film before the orientation crystallization is completed. Wherein X is an alkoxy group, Y is an organic functional group, Z is at least one group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, an alicyclic group and a polymer chain group, and n is The number of 1 to 90, m is the number of 1 to 90, (n + m)
Is a number of 2 to 90, and (n + m + p) is a number of 6 to 100. And applying a coating agent containing a high-molecular-weight silane coupling agent, followed by drying, stretching and heat setting to complete orientation crystallization.