JP2001322217A - Laminate and laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film highly excellent in adhesiveness and good in a laminated film recovery properties and productivity, in a thermoplastic resin molded object, especially, a laminate of a thermoplastic film and a heat- resistant resin layer. SOLUTION: The laminate or the laminated film is constituted by laminating a laminated film having a partially imidated polyamic acid with an imidation ratio of 10-80% on at least one surface of the thermoplastic resin molded object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate, particularly a laminate film, which is a laminate (film) in which a laminate film whose starting material is polyamic acid is provided on a thermoplastic resin molded product (film). The present invention relates to a laminate (film) having excellent heat resistance, flame retardancy, and recoverability of a laminated film suitable for industrial materials, magnetic materials, and the like.

[0002]

2. Description of the Related Art Conventionally, molded articles of thermoplastic resins such as polyester and polyolefin, particularly thermoplastic films,
Due to its transparency, mechanical properties, electrical properties, etc., it is used as various industrial materials such as magnetic recording materials, electrical insulating materials, capacitor materials, packaging materials, photographs, graphics, and thermal transfer. On the other hand, films represented by aromatic polyamides have characteristics such as high heat resistance, dimensional stability, mechanical strength, and nonflammability, and are used for high-density magnetic recording media, flexible printed boards, and the like. Further, a laminate in which a heat-resistant polymer layer is coated on a thermoplastic film (Japanese Patent Application Laid-Open No. 1-973838) and a laminated product in which a heat-resistant polymer layer is laminated (Japanese Patent Application Laid-Open No. 3-164244) are known.

[0003] However, thermoplastic films have thermal disadvantages such as being softened or melted by heat and easy to burn, and the danger of fire spreading due to falling of the molten polymer. Heat resistance,
A film made of a highly flame-retardant resin usually has a low productivity because it is formed by a wet film-forming method, becomes a very expensive film, and its use is limited. In order to compensate for this, laminates by laminating or applying both have been proposed. However, in order to improve the adhesiveness, an adhesive layer is provided at the interface or an adhesive composition is added to the heat-resistant resin layer. Add things,
In addition, it is based on a method of bonding at a temperature of 200 ° C. or more, and the adhesion is insufficient, and the heat resistance of the heat-resistant and flame-retardant resin is affected by other components in the flame-retardant resin. The function of the thermoplastic film is impaired, or the flatness of the thermoplastic film is deteriorated due to exposure to heat at a high temperature with an adhesive layer interposed. Further, when the thermoplastic film is crystal-oriented, the interfacial adhesion was insufficient. In addition, dust enters due to processes such as application and lamination on the film,
It has been difficult to obtain a product having a high degree of flatness due to the inclusion of air bubbles and a long-time high-temperature drying step. Heat-resistant, flame-retardant resins such as polyimides have low solubility in solvents because the precursor polyamic acid is highly imidized, making it difficult to apply, and furthermore, the resin after use. There was a problem in that the layers could not be collected, it was difficult to reuse them, and it took time to dispose.

[0004]

SUMMARY OF THE INVENTION The present invention provides a laminate which does not have these drawbacks and which has a high adhesion between a thermoplastic film and a heat-resistant and flame-retardant resin layer and has good heat-resistant and flame-retardant properties. The purpose is to do so.

[0005]

Means for Solving the Problems A laminate or a laminate film of the present invention is provided on at least one surface of a thermoplastic resin molded article.
The laminated film having a partially imidized polyamic acid having an imidization ratio of 10% or more and 80% or less is laminated.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The most preferred example of the laminate of the present invention is a laminate film in which a thermoplastic resin molded body is a thermoplastic resin film. Hereinafter, the present invention will be described in detail using a laminated film as an example, but the present invention is not limited thereto.

In the present invention, at least one side of the thermoplastic film substrate has an imidization ratio of 10% or more, and
% Or less of a partially imidized polyamic acid. The polyamic acid has a repeating unit (amic acid residue) represented by the following general formula 1.

[0008]

Embedded image

[0009] wherein R is, for example groups shown in general formula 2 is used, X, Y _{are, -O -, - CH 2 -} , - CO
_{-, - SO 2 -, -} S -, - C (CH 3) 2 - is selected from such as, but not limited thereto. Further, a part of the hydrogen atoms on the aromatic ring of the general formula 1 may be a halogen group such as chlorine, fluorine or bromine (particularly preferably chlorine), a nitro group,
It includes those substituted with substituents such as alkyl groups such as methyl group, ethyl group and propyl group (particularly preferable is methyl group), and alkoxy groups such as methoxy group, ethoxy group and propoxy group, and also forms the polymer. And those in which the hydrogen in the amide bond is replaced by another substituent.

[0010]

Embedded image

In particular, a polymer in which the aromatic ring represented by the general formula 2 is bonded at the para position accounts for 50 mol% or more, more preferably 70 mol% or more of the total aromatic ring, is a heat-resistant, flame-retardant, and dimensionally stable polymer. It is preferable in terms of properties. Some of the hydrogen atoms on the aromatic ring are chlorine, fluorine, bromine and other halogen groups (particularly preferably chlorine), nitro groups, methyl groups, ethyl groups, alkyl groups such as propyl groups (particularly preferably methyl groups), When the aromatic ring substituted with a substituent such as an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group accounts for 30 mol% or more, preferably 50 mol% or more of the whole, moisture resistance, dimensional stability by moisture absorption, and the like are obtained. This is preferred because

The imidation ratio according to the present invention is the ratio of the amide group (or its residue) and the carboxyl group (or its residue) adjacent to the amic acid residue of the polyamic acid being dehydrated and closed. . The amic acid residue in the polyamic acid has two sets of the imidizable adjacent amide group (or its residue) and a carboxyl group (or its residue) (hereinafter, referred to as an imidizable site), The imidation ratio (I) is obtained by the following equation. Imidation ratio (I) = 100 * P1 / (P1 + P2) P1: Number of moles of imidizable sites capable of imidization in partially imidized polyamic acid.

P2: the number of moles of imidizable sites not imidized in the partially imidized polyamic acid.

According to the present invention, the imidization rate of the laminated film is required to be 10% or more and 80% or less by the imidization treatment. The reason is that imidation rate is 10%
If it is less than 1, not only the heat resistance and the flame-retardant function are not sufficiently exhibited, but also the polymer melted at the time of burning may fall and spread to other combustibles. For this reason, the imidation ratio of the partially imidized polyamic acid in the laminated film needs to be 10% or more, and more preferably 20%.
% Or more, more preferably 30% or more, and particularly preferably 4% or more.
0% or more. Also, if the imidation ratio of the partially imidized polyamic acid in the laminated film is more than 80%, the recoverability of the laminated film becomes difficult. Further, in order to increase the imidation ratio to more than 80%, the laminated film must be exposed to extremely severe heating conditions, under which conditions ordinary thermoplastic films are difficult to maintain their properties. is there. Therefore, the imidization ratio must be preferably 80% or less, more preferably 75% or less, further preferably 70% or less, and particularly preferably 65% or less.

The feature of the configuration of the present invention is that the infrared absorption spectrum
Can be defined from the file characteristics. That is, of the laminate
The infrared absorption spectrum of the laminated film was measured, and 1550 cm^-1
From 1450cm^-1Of the characteristic absorption of the benzene ring appearing in
Luminous intensity (a1) and 1800cm ^-1From 1750cm^-1Present
The absorbance (a2) of the characteristic absorption of the imide group to be obtained is determined. This
Then, the relative value of a2 based on a1 is calculated from the following equation.
And r.

R = a2 / a1 Subsequently, the laminated film is heat-treated at 250 ° C. for 120 minutes. It is assumed that the imidation ratio of the imidized polyamic acid after this heat treatment is 100%. The infrared absorption spectrum of the laminated film in this laminate was similarly measured, and the relative value of the absorbance (a'2) of the characteristic absorption of the imide group based on the absorbance (a'1) of the characteristic absorption of the benzene ring was determined. It is determined as r ′.

R ′ = a′2 / a′1 In the present invention, the relative value of r based on r ′ is determined from the following equation to determine the imidization ratio I.

I (%) = 100 × (r / r ′) The parameter I needs to be 10% or more and 80% or less, and the lower limit is preferably 20%.
Or more, more preferably 30% or more, and still more preferably 40% or more.
% Or more, and the upper limit is preferably 75% or less, more preferably 70% or less, and still more preferably 65% or less.
It is as follows.

In the present invention, the imidization treatment is not particularly limited, but includes heat treatment, ultraviolet irradiation treatment, infrared irradiation treatment, electron beam irradiation treatment and the like. Among these, heat treatment is preferred from the viewpoint of productivity and the effect of improving the imidization rate. More specifically, it is more preferable to perform the heat treatment at a temperature of 200 ° C. or higher.

In the present invention, the partially imidized polyamic acid preferably contains an amic acid residue substantially as a main component. That is, it is most preferable to include the repeating unit of the general formula 1 alone, but it is possible to include the repeating unit in the form of a copolymer. In that case, the amic acid residue is preferably 50 mol%.
The content is more preferably at least 70 mol%, further preferably at least 80 mol%, more preferably at least 90 mol%, particularly preferably at least 95 mol%. If the ratio is below the lower limit, heat resistance and flame retardancy are lost, which is not preferable. However, in the above-mentioned copolymerization ratio, the amic acid residue is the sum of the imidized amic acid residue (one or both of the imidizable sites is imidized) and the non-imidized amic acid residue. Is calculated as

In one embodiment of the present invention, the laminated film is laminated on at least one surface of the biaxially oriented thermoplastic film substrate substantially without the interposition of an adhesive layer. No intervening layer means that no layer other than the base material and the laminated film forming substance is formed at the interface between the base material and the laminated film in a state where the laminated film is laminated on the base material. . Even if a layer corresponding to the adhesive layer exists, it can be considered that the layer does not exist if its thickness is 100 nm or less (preferably 80 nm or less, more preferably 50 nm or less). However, at the interface, a mixed phase of the base material and the laminated film (the thickness is preferably 20 to 500 nm, more preferably 50 to 200 n
The formation of m) is particularly preferable because the adhesiveness is further improved, and the layer is out of the definition of the adhesive layer. Conversely, examples of the material corresponding to the adhesive layer include acrylic resin, polyester resin, urethane resin, polyolefin resin, polycarbonate resin, alkyd resin, epoxy resin, urea resin, phenol resin, silicone resin, and rubber-based resin. Resins.

The adhesion between the laminated film of the laminated film thus obtained and the substrate is preferably 1 in T-peeling.
00g / 25mm width or more, more preferably 300g / 2
It is preferable that the layers are laminated so as to have a width of 5 mm or more. 1
If the width is less than 00 g / 25 mm, a problem may occur that the laminated film is peeled off when used for various applications.

Even if the laminated film of the present invention is laminated on only one surface of a thermoplastic resin (hereinafter, referred to as a one-layer structure), a sufficiently practical heat-resistant effect is exhibited. Further, even when the single-layered body is exposed to a flame from both sides or the non-laminated film side, the single-layered layered body exhibits a flame-resistant performance such that molten polymer droplets are not dropped. Of course, if both surfaces are laminated (hereinafter, referred to as a double-sided laminated body), the heat and flame resistance performance is remarkably improved as compared with the single-layer structure. In the case of this double-sided laminate, even if both surfaces are exposed to the flame, an effect is exhibited such that the fire extinguishes itself immediately after the flame is released.

The thermoplastic resin film and the laminated film serving as the base film of the present invention may contain various additives, resin compositions, cross-linking agents, etc. as long as the effects of the present invention are not impaired. For example, antioxidants, heat stabilizers, ultraviolet absorbers, organic or inorganic particles, pigments, dyes, antistatic agents,
Nucleating agent, acrylic resin, polyester resin, urethane resin, polyolefin resin, polycarbonate resin, alkyd resin, epoxy resin, urea resin, phenol resin, silicone resin, rubber resin, wax composition, melamine crosslinker, oxazoline crosslinker , Methylolated, alkylolated urea-based crosslinking agents, acrylamide, polyamide, epoxy resins, isocyanate compounds, aziridine compounds, various silane coupling agents, various titanate coupling agents, and the like.

Among them, when inorganic particles such as silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, titanium oxide, and fine metal powder are added. It is particularly preferable because the lubricity and scratch resistance are improved. The average particle size of the inorganic particles is 0.
005 to 5 μm, preferably about 0.05 to 1 μm. It is desirable that the amount of addition be 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight.

However, if the laminated film excessively contains an organic compound such as a resin other than the partially imidized polyamic acid due to copolymerization or mixing, the heat resistance may be undesirably reduced. In this case, the content of the amic acid residue in the organic compound of the laminated film is preferably 50% by weight or more. It is more preferably at least 70% by weight, further preferably at least 75% by weight, particularly preferably at least 80% by weight. Note that a catalyst that promotes imidation may be added. Examples of the catalyst include, but are not limited to, tertiary amines such as pyridine, α-picoline, β-picoline, γ-picoline, trimethylamine, dimethylaniline, triethylamine, and isoquinoline, and derivatives thereof. The amount of the catalyst added is preferably within a range that does not impair the effects of flame retardancy and heat resistance, and is 0.5% or more and less than 20%, preferably 1% or more and less than 15% of the total solids. More preferably, 2% or more,
Less than 10%.

The thermoplastic film in the laminated film of the present invention is a film that can be melt-extruded, and is preferably a crystal oriented by biaxial stretching. Specific examples thereof include polyester, polyolefin, polyamide,
Biaxially oriented film such as polyphenyl sulfide, especially polyester film is transparent, dimensional stability,
It is preferable in terms of mechanical properties and adhesiveness with the partially imidized polyamic acid layer to be laminated in the present invention.
The preferred polyester is not particularly limited, but may be polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene naphthalate, or the like, and may be a mixture of two or more of these. Further, these may be copolymerized with another dicarboxylic acid component or diol component. In this case, the crystallinity of the film in which the crystal orientation is completed is 25%.
% Or more, preferably 30% or more, more preferably 35%
The above are preferred. Further, a composite film having two or more layers of an inner layer and a surface layer may be used. For example, a composite film having substantially no particles in the inner layer portion and having a layer containing the particles in the surface layer portion, a laminate film having coarse particles in the inner layer portion and containing fine particles in the surface layer portion And a composite film in which the inner layer is a layer containing fine bubbles and the surface layer is substantially free of bubbles. In the composite film, the inner layer portion and the surface layer portion may be of different polymers or of the same type. When the crystallinity is less than 25%, dimensional stability and mechanical strength are likely to be insufficient. When the above-mentioned polyester is used, its intrinsic viscosity (measured in o-chlorophenol at 25 ° C) is preferably 0.4 to 1.2 dl / g, and 0.5 to 0.8 d / g.
More preferably, it is 1 / g.

The thermoplastic film in the present invention is preferably biaxially oriented with the laminated film provided.
Biaxially oriented refers to unstretched, that is, a thermoplastic film before crystal orientation is completed, which is stretched about 2.5 to 5 times in the longitudinal direction and width direction, respectively, and then crystal orientation is completed by heat treatment. Yes, it indicates a biaxially oriented pattern in wide-angle X-ray diffraction. If the thermoplastic film is not biaxially oriented, the dimensional stability of the laminated film,
In particular, the dimensional stability and mechanical strength under high temperature and high humidity are insufficient, and the flatness is poor.

The thickness of the thermoplastic film of the present invention is not particularly limited, but is preferably 0.5 to 500 μm,
00 μm is more preferable, and 10 to 250 μm is still more preferable. If the value is below the lower limit of the numerical range, the handling property is reduced, and if the value is above the upper limit, the flame retardancy becomes poor, which may be undesirable.

A preferred production method for obtaining a laminated film in such a state is described below, but is not necessarily limited thereto.

For example, if the polymer (polyamic acid) to be laminated before the crystal orientation of the base material (thermoplastic film) is completed or the solvent dissolution property or the coating performance is not hindered, partial imidization may already be performed. A suitable method is to apply a coated polyamic acid), stretch the solvent together with the substrate before drying the solvent, and then evaporate and evaporate the solvent to complete the crystal orientation of the substrate. In this case, it is preferable that most of the solvent to be used remains after the coating and before the stretching and in the preheating step and the stretching step, and is evaporated and evaporated in the heat treatment step after the stretching. For example, when the base material is a polyester resin, the preheating and the stretching temperature are 85 to 150 ° C., and the heat treatment temperature after the stretching is preferably 200 to 250 ° C. Therefore, the solvent used has a boiling point of 160 ° C. or more. 25
Those having a temperature of 0 ° C. or less are preferred. N-methyl-2-pyrrolidone is particularly preferred as a solvent for dissolving a heat-resistant resin precursor such as polyamic acid. Although the thickness of the laminated film of the laminated film produced by such a method is not particularly limited, it is desirably about 0.1 to 5 μm, preferably about 0.2 to 3 μm from the viewpoint of coating properties and drying properties. The thickness of the base film is about 0.5 to 500 μm and can be appropriately selected depending on the application.

As a method of applying the coating liquid for forming a laminated film on the substrate, various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, and a die coating method can be used. In particular, the die coating method is suitably used from the viewpoint of coating properties depending on the viscosity of the coating liquid.

The laminated film is more preferably stretched in the longitudinal direction and the width direction after the solvent is volatilized, because the strength and rigidity of the laminated film can be further improved. When re-stretching in the longitudinal direction or the width direction, the stretching temperature is preferably 150 to 280 ° C, more preferably 200 to 250 ° C, and the stretching ratio is preferably about 1.1 to 2 times. Further, after re-stretching, further 210-280 ° C., preferably 220 ° C.
It is desirable to heat-treat at a temperature of up to 260 ° C.

In order to dry the solvent more efficiently, heating by far infrared rays may be used.

In order to improve the adhesion between the laminated film and the thermoplastic resin, a corona discharge treatment is performed on the surface of the thermoplastic resin on which the laminated film is to be provided, or the laminated film is provided during the film forming process. It is effective to perform a stretching treatment after the formation. That is, on the laminated surface of the thermoplastic resin, 5 to 10
0 W · min / m ² (preferably, 20 to 60 W · min / m ² )
m ² ) having a surface modification obtainable by corona discharge treatment (not necessarily corona discharge treatment if the same surface modification is obtained) on the laminated surface of the thermoplastic resin improves the adhesiveness. It is valid. On the other hand, in the stretching treatment after lamination, the solution in which the components of the laminated film are dissolved is applied before the thermoplastic resin is crystallized, so that the solvent of the solution penetrates the thermoplastic resin, and the like, so that the lamination boundary is formed. A mixed phase in which both are mixed is formed, which is effective for improving the adhesiveness.

The laminated film thus obtained is
It is excellent in interfacial adhesion, and because there is no adhesive layer at the interface, it has properties that can not be achieved with conventional thermoplastic films in terms of flame retardancy, surface heat resistance, flatness, etc.
In addition, since imidization is not completely completed, it has appropriate solubility in dipolar aprotic solvents and has excellent properties of recovering laminated films, so it can be used for electrical insulating materials, thermal transfer materials, graphic materials, etc. It can be suitably used for various industrial materials and magnetic materials.

[0037]

[Method for measuring characteristics and method for evaluating effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Thickness of Laminated Film A section was cut out from the laminated film, and the section was observed with a transmission electron microscope to measure the thickness of the laminated film. When there was a mixed phase, the thickness including the mixed phase was defined as the lamination thickness.

(2) Method for measuring imidation ratio The infrared absorption spectrum of the heat-resistant resin layer of the laminated film was measured using a Fourier transform infrared absorption spectrophotometer FT / IR-5000 manufactured by JASCO Corporation. 5 was measured by the ATR method using a 45 ° crystal as a prism, and 1550c
absorbance of characteristic absorption of the benzene ring which appears from m ^-1 to 1450 cm ^-1 (a1) and 1750 cm ^-1 from 1800 cm ^-1
The absorbance (a2) of the characteristic absorption of the imide group appearing in (1) was determined. At this time, the relative value of a2 with respect to a1 was obtained from the following equation, and was defined as r.

R = a2 / a1 Subsequently, this laminated film was heat-treated at 250 ° C. for 120 minutes, and the imidization ratio of the imidized polyamic acid after this heat treatment was assumed to be 100%. The infrared absorption spectrum of the heat-resistant resin layer in this film was similarly measured by the ATR method, and the absorbance (a'2) of the characteristic absorption of the imide group based on the absorbance (a'1) of the characteristic absorption of the benzene ring was used. The relative value was obtained and set as r '.

R ′ = a′2 / a′1 In the present invention, the relative value of r based on r ′ was determined from the following equation and was defined as the imidation ratio I.

I (%) = 100 × (r / r ′) (3) Heat resistance On a flame of a gas burner of about 2 cm, a laminated film having a size of 10 cm × 10 cm framed at 10 cm is horizontally placed. It was held for 3 seconds and the state of the surface was observed.

No change: が Holes opened: × (◎) was regarded as good heat resistance.

(4) Flame Retardancy The laminated film is cut into a strip of 2 cm × 15 cm, and one end in the longitudinal direction is gripped with a clip to suspend the laminated film. After exposing the other end to a flame of a gas burner of about 2 cm for 10 seconds, it was observed whether the laminated film burned or whether molten polymer droplets dripped.

Self-extinguishing within 30 seconds after flame-off: ◎ Fire spread to clip, but no molten polymer droplets drip: ○ Molten polymer droplets drip: × (◎), (○) difficult Good flammability.

(5) Solubility in a dipolar aprotic solvent The laminated film whose overall thickness was measured was immersed in a dipolar aprotic solvent (NMP), left at 50 ° C. for 24 hours.
The film is washed with water to remove MPs,
Let dry for minutes. The film was left at 23 ° C. and 65% for 24 hours, and the film thickness was measured. The solubility m = Δt / tl × 100 (%) where the thickness decrease Δt and the thickness of the laminated film before immersion are tl was defined as the solubility of the laminated film. The total thickness was measured at 10 points, and the average value was used as the total thickness.

Dissolve completely (m = 100): ５０ 50% or more and less than 100% of the laminated film is dissolved (50 ≦ m <100): ○ 10% or more and less than 50% of the laminated film is dissolved (10 ≦ m <50): Δ The laminated film was dissolved only by less than 10%. (M <10): × (）), (○) were evaluated as having good solubility.

(6) Adhesive Strength Polyurethane ("Takelac") is applied to the laminated surface of the laminated film.
A-385 / "Takenate" A-50 (6/1 by weight ratio)
): An ethyl acetate solution of Takeda Pharmaceutical Co., Ltd.) was applied to a thickness of 3 μm after drying, dried at 110 ° C. for 1 minute, and then subjected to corona discharge on the polyurethane-coated surface. The treated biaxially oriented polypropylene film having a thickness of 50 μm was laminated and heat-laminated at 90 ° C. Thereafter, heat treatment is performed at 45 ° C. for 70 hours,
Sampling was performed into a strip having a width of 5 mm, and T-peeling was performed at a rate of 100 mm / min using a Tensilon-type tensile tester to determine the interfacial adhesive strength. When the heat-resistant resin layer was laminated on only one side, the value of only one side was taken, and when it was laminated on both sides, the average value of both sides was taken. Peel stress is 300g / 2
When the laminated film did not peel off at 5 mm or more, the measurement was not possible.

Peeling stress measurement not possible: Peeling stress is 100 g / 25 mm or more and less than 300 g / 25 mm: Peeling stress is less than 100 g / 25 mm: × (）), (○) were evaluated as good adhesion.

[0050]

Next, the present invention will be described based on examples.
It is not necessarily limited to this.

<Laminated Film Forming Coating Solution> The solution containing polyamic acid as a main component used was prepared as follows.

In a dried flask, weighed 4,4'-
6.0 g of diaminodiphenyl ether was added to N-methyl-2.
-Add with pyrrolidone, stir and dissolve to give a total of 10
The volume was 0 ml. Next, pyromellitic dianhydride was added to this solution with the 4,4'-diaminodiphenyl ether 100
It was added so that the reaction temperature would be 60 ° C. or less, relative to 100 mol. Thereafter, when the viscosity became constant, the polymerization was terminated, and the polymerization was terminated by cooling the solution to room temperature to obtain a polyamic acid polymerization solution.
This solution was appropriately diluted with N-methyl-2-pyrrolidone so as to have a desired concentration according to the thickness of the laminated film, and this was used as a coating solution.

Example 1 0.015% by weight of colloidal silica having an average particle size of 0.4 μm and 0.05% by weight of colloidal silica having an average particle size of 1.5 μm
A polyethylene terephthalate (hereinafter referred to as PET) containing 0.05% by weight (intrinsic viscosity: 0.63 dl / g) chips were sufficiently vacuum-dried at 180 ° C., fed to an extruder, melted at 285 ° C., and then T-shaped. The sheet was extruded into a sheet, wound around a mirror-surface cast drum having a surface temperature of 20 ° C. using an electrostatic application casting method, and cooled and solidified. 2. The unstretched sheet is rolled in a roll group heated to 95 ° C. in the longitudinal direction.
The film was stretched 5 times to obtain a uniaxially stretched film. A coating liquid for forming a laminated film (5% by weight liquid) was applied on both sides of the film by a die coating method so that the final laminated thickness per one side was 0.3 μm. While holding both ends of the applied film with clips, the film was guided to a preheating zone at 100 ° C.
The film was stretched 3.5 times in the width direction in a heating zone at ℃. Further, heat treatment was continuously performed with a heat treatment sone at 230 ° C. for 10 seconds to complete the crystal orientation of the base film. This laminated film had an overall thickness of 50 μm, a laminated thickness per side of 0.3 μm, and a mixed phase at the interface of 100 nm, which was excellent in transparency and flatness. The imidation ratio of the laminated film was 60%.

Example 2 A laminated film was obtained in the same manner as in Example 1 except that the thickness of the laminated film on one side was changed to 3 μm. The imidation ratio of this laminated film was 50%.

Examples 3 and 4 Lamination was carried out in the same manner as in Example 1 except that the thickness of the laminated film per side was 1 μm and the heat treatment time was 5 seconds (Example 3) or 20 seconds (Example 4). A film was obtained.
The imidation ratio of this laminated film was 10% (Example 3) or 80% (Example 4).

Example 5 Biaxially oriented PET film (Lumirror T6) having a thickness of 50 μm
0 (manufactured by Toray Industries, Inc.) on both surfaces in a 98% nitrogen atmosphere, with a processing strength of 21 W · min / m ² (applied voltage 25000 V, applied current 0.1 A, processing speed 12 m / min, processing width 0.1).
m), after applying the corona discharge treatment, the same coating liquid for forming a laminated film as in Example 1 is applied to one surface so that the final laminated thickness per one surface becomes 0.3 μm, and dried at 150 ° C. for 1 minute. After that, the other side was similarly coated and dried. The film was heat-treated at 230 ° C. for 5 minutes to obtain a laminated film.
The imidation ratio of this laminated film was 70%.

Embodiment 6 In the embodiment 1, the thickness of the laminated film per one side is set to 0.08.
A laminated film was obtained in the same manner except that the thickness was changed to μm. The imidation ratio of this laminated film was 65%.

Comparative Examples 1 and 2 A laminated film was prepared in the same manner as in Example 1 except that the thickness of the laminated film on one side was 1 μm and the heat treatment time was 2 seconds (Comparative Example 1) and 40 seconds (Comparative Example 2). I got The imidation ratio of this laminated film was 5% (Comparative Example 1) and 85%.
(Comparative Example 2).

Comparative Example 3 A laminated film was prepared in the same manner as in Example 1, except that the NMP solution (concentration: 5% by weight) of polyether sulfone (Sumika Excel 4100P, manufactured by Sumitomo Chemical Co., Ltd.) was used as the coating liquid for forming the laminated film. Obtained. The solubility of the laminated film is ○,
The adhesive strength was ◎, and the heat resistance and flame retardancy were ×.

Example 7 The same procedure as in Example 1 was applied to only one surface, and the thickness of the laminated film was set to 5.
A laminated film was obtained in the same manner except that the thickness was changed to 0 μm. The imidation ratio of the laminated film was 60%, heat resistance and adhesiveness were ◎, flame retardancy and solubility were ○.

Table 1 shows the evaluation results of the film properties of Examples 1 to 7 and Comparative Examples 1 to 3. Examples 1 to 7 were good in all items, but Comparative Examples 1 to 3 had a bad point in any of the items.

[0062]

[Table 1]

[0063]

The laminate of the present invention provides a heat-resistant and flame-retardant laminate having excellent adhesiveness and laminate film recoverability and excellent productivity.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 9:00 B29L 9:00 F term (Reference) 4F100 AK01A AK41A AK42 AK46B AK46C AK46K AT00A BA02 BA06 BA10B BA10C EH46A EJ38A GB41 JB16A JL00 JL02 JL11 4F210 AA24 AA40 AG01 AG03 AH36 AH38 QA02 QA03 QC06 QD08 QD34 QG01 QG15 QG18 QL02 QW07

Claims (10)

[Claims] (1) at least one surface of a thermoplastic resin molded body,
A laminate comprising a laminate film having a partially imidized polyamic acid having an imidization ratio of 10% or more and 80% or less. 2. The method according to claim 1, wherein at least one surface of the thermoplastic resin molded article has
A laminate characterized in that a laminate film comprising a partially imidized polyamic acid having an imidization ratio of 10% or more and 80% or less is laminated substantially without interposing an adhesive layer. 3. A laminated film comprising a partially imidized polyamic acid having an imidation ratio of 10% or more and 80% or less is laminated on at least one surface of the thermoplastic film. Laminated film. 4. A laminated film comprising a partially imidized polyamic acid having an imidization ratio of 10% or more and 80% or less on at least one surface of a thermoplastic film without substantially interposing an adhesive layer. A laminated film characterized by being laminated. 5. An imidization ratio of 1 on both surfaces of a thermoplastic film.
A laminated film, characterized in that a laminated film having a partially imidized polyamic acid of 0% or more and 80% or less is laminated substantially without interposing an adhesive layer. 6. The laminated film according to claim 3, wherein said thermoplastic film is a biaxially oriented thermoplastic film. 7. The laminated film according to claim 3, wherein said thermoplastic film is a polyester film. 8. The method according to claim 3, wherein said laminated film is stretched after lamination.
A laminated film according to any one of claims 1 to 7. 9. The laminated film has a thickness of 0.1 μm or more, and
The laminated film according to any one of claims 3 to 8, wherein the thickness is 5 µm or less. 10. The laminated film according to claim 3, wherein said laminated film is laminated by coating.